glucagon-like-peptide-1 has been researched along with Diabetes-Mellitus--Type-2* in 3257 studies
1217 review(s) available for glucagon-like-peptide-1 and Diabetes-Mellitus--Type-2
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Pharmacotherapy for Type 2 Diabetes Mellitus: What's Up and Coming in the Glucagon-Like Peptide-1 (GLP-1) Pipeline?
Glucagon-like peptide-1 (GLP-1), an incretin hormone, is known to lower glucose levels, suppress glucagon secretion, and slow gastric emptying. These properties make GLP-1 an ideal target in treating type 2 diabetes mellitus (T2DM). There are many FDA-approved GLP-1 agonists on the market today, several of which have demonstrated benefit beyond improving glycemic control. Given the beneficial effects of GLP-1 agonists in patients with T2DM, new drugs are in development that combine the mechanism of action of GLP-1 receptor agonism with novel mechanisms and with drugs that promote GLP-1 secretion. These agents are designed to improve glycemic control and target greater body weight reduction. This article discusses new GLP-1 drugs in the pipeline for the treatment of T2DM. Topics: Body Weight; Diabetes Mellitus, Type 2; Glucagon-Like Peptide 1; Glucagon-Like Peptide-1 Receptor; Humans; Hypoglycemic Agents | 2023 |
Glucagon-Like Peptide-1 Receptor Agonists in the Treatment of Obesity.
Obesity treatment based on glucagon-like peptide-1 receptor agonists (GLP-1 RAs) proved to limit morbidity and mortality in adult population. In children, optimizing lifestyle intervention (LSI) and reducing culpable environmental exposures represent the mainstay strategy for obesity prevention and management. However, there remains a subset of children and adolescents whose obesity is resistant to lifestyle approach. For these poor responders, the need for safe and effective weight-reducing agents is apparent. The purpose of this review is to provide an overview of the efficacy and safety of approved GLP-1 RA in the management of adult and pediatric obesity.. We presented the main outcomes of clinical trial programs called SCALE and STEP that supported a market authorization approval for liraglutide and semaglutide for the treatment of obesity in adult population. Then, we summarized the studies on the efficacy of GLP-1 RA in pediatric obesity that have been accumulating from 2 larger studies with liraglutide and few other smaller studies with exenatide and liraglutide. The results indicate that GLP-1 RA is safe, tolerable, and effective in reducing weight and also in improving cardiometabolic profile in children with obesity and poor response to LSI alone. At present, liraglutide is the first and so far the only GLP-1 RA that received FDA approval in 2020 for use in children aged 12-17 years with obesity. New trials including semaglutide for pediatric obesity are ongoing.. There is a strong interest in current use and further development of obesity treatments based on glucagon-like peptide-1 (GLP-1) agonism. In adolescents with obesity, who are poor responders to lifestyle approach, the use of GLP-1 RA as an adjunct to LSI is effective and safe. Due to limited experience, a general recommendation is to prioritize long acting over short acting GLP-1 RA because they are approved for the treatment of obesity and have better tolerability, safety, and treatment response effect. In the future research, more high-grade evidence including novel iterations of GLP-1 agonism and long-term follow-ups are needed in pediatric population. Topics: Adolescent; Child; Diabetes Mellitus, Type 2; Glucagon-Like Peptide 1; Glucagon-Like Peptide-1 Receptor; Humans; Hypoglycemic Agents; Liraglutide; Pediatric Obesity | 2023 |
Knowledge Domain and Emerging Trends of Glucagon-Like Peptide 1 Receptor Agonists in Cardiovascular Research: A Bibliometric Analysis.
Patients with type 2 diabetes (T2DM) are more likely to have cardiovascular disease (CVD). Glucose-lowering drugs with cardiovascular benefits represented by Glucagon-like peptide 1 receptor agonists (GLP1RAs) were discovered and gained more and more attention. Data from 1985 to the 2021 were downloaded in the Web of Science Core Collection (WoSCC) database. CiteSpaceV was used for bibliometric analysis to find research hotspots and frontiers. The 2088 papers were published by 74 countries (regions), 876 institutions, and 2203 authors. The annual publications increased over time from 2005 to 2020. DIABETES OBESITY METABOLISM published the most papers. The USA and China were the top 2 productive nations. The leading institution was the University of Copenhagen, and the most productive researcher was John B Buse. The most cited paper is "Liraglutide and Cardiovascular Outcomes in Type 2 Diabetes" (by Marso SP, 2016). The research hotspots include the effects of GLP1RA on cardiovascular outcomes, efficacy, complicated metabolic abnormalities, protective mechanisms, and other novel anti-diabetic drugs for cardiovascular protection. Research frontiers include cardiovascular studies on semaglutide, as well as the most prominent research approach in the field-placebo-controlled trial. Numerous countries, institutions, and authors have focused on GLP1RA in cardiovascular research and a great deal of literature has been published. Five research hotspots and two frontiers illustrate the current status and emerging trends of GLP1RA in cardiovascular research. The cardiovascular effects and clinical efficacy of GLP1RA are a current hot topic that is rapidly evolving and of high research value. Topics: Bibliometrics; Cardiovascular Diseases; Diabetes Mellitus, Type 2; Glucagon-Like Peptide 1; Glucose; Humans | 2023 |
Red meat consumption and risk factors for type 2 diabetes: a systematic review and meta-analysis of randomized controlled trials.
Results from observational studies suggest an association of red meat intake with risk of type 2 diabetes mellitus (T2D). However, results from randomized controlled trials (RCTs) have not clearly supported a mechanistic link between red meat intake and T2D risk factors. Therefore, a systematic review and meta-analysis were conducted on RCTs evaluating the effects of diets containing red meat (beef, pork, lamb, etc.), compared to diets with lower or no red meat, on markers of glucose homeostasis in adults.. A search of PubMed and CENTRAL yielded 21 relevant RCTs. Pooled estimates were expressed as standardized mean differences (SMDs) between the red meat intervention and the comparator intervention with less or no red meat.. Compared to diets with reduced or no red meat intake, there was no significant impact of red meat intake on insulin sensitivity (SMD: -0.11; 95% CI: -0.39, 0.16), insulin resistance (SMD: 0.11; 95% CI: -0.24, 0.45), fasting glucose (SMD: 0.13; 95% CI: -0.04, 0.29), fasting insulin (SMD: 0.08; 95% CI: -0.16, 0.32), glycated hemoglobin (HbA1c; SMD: 0.10; 95% CI: -0.37, 0.58), pancreatic beta-cell function (SMD: -0.13; 95% CI: -0.37, 0.10), or glucagon-like peptide-1 (GLP-1; SMD: 0.10; 95% CI: -0.37, 0.58). Red meat intake modestly reduced postprandial glucose (SMD: -0.44; 95% CI: -0.67, -0.22; P < 0.001) compared to meals with reduced or no red meat intake. The quality of evidence was low to moderate for all outcomes.. The results of this meta-analysis suggest red meat intake does not impact most glycemic and insulinemic risk factors for T2D. Further investigations are needed on other markers of glucose homeostasis to better understand whether a causal relationship exists between red meat intake and risk of T2D.. CRD42020176059. Topics: Animals; Blood Glucose; Cattle; Diabetes Mellitus, Type 2; Glucagon-Like Peptide 1; Glucose; Humans; Insulin Resistance; Meat; Randomized Controlled Trials as Topic; Red Meat; Risk Factors; Sheep | 2023 |
Role of DPP4 and DPP4i in Glucose Homeostasis and Cardiorenal Syndrome.
The objective of the review led to the pursuit of adopting dipeptidyl peptidase-4 inhibitors (DPP4i) as a novel pharmacotherapy in diabetes mellitus (DM) and cardiorenal syndrome (CRS). The CRS is defined as the co-existence of myocardial ischemia with renal failure. At present, the commercially available drugs enhance insulin secretion or action. However, most of the drugs are associated with adverse effects, such as weight gain or hypoglycemia. As a result, newer therapies with better safety and efficacy profiles are being explored. The DPP4 protease enzyme is involved in cardiovascular and renal diseases in association with over-expressed cytokines. The novel characteristic of DPP4i is to control the elevated blood glucose levels in response to nutrient ingestion without causing hypoglycemia. Also, DPP4i are indirectly involved in reducing myocardial ischemia by promoting cardioprotective peptides. They protect the glucagon-like peptide 1 (GLP-1) from the deteriorating effect of the DPP4 enzyme. The GLP-1 receptors (GLP-1R) are abundantly expressed in renal and cardiovascular tissue. The overexpression of GLP-1R will confer protection of the heart and kidney during CRS. DPP4i were found to significantly clear plasma glucose by the simultaneously activating natural thrombolytic system and increasing insulin levels. They can be used in the early stages of the disease, including pre-diabetes or obesity combined with impaired incretin response, while the combination of DPP4i with metformin or thiazolidinediones as insulin sensitizers offers an additional improvement in the treatment of DM. With its positive attributes in a host of associated parameters of interest, DPP4i are studied extensively in the present review. Topics: Cardio-Renal Syndrome; Diabetes Mellitus, Type 2; Dipeptidyl Peptidase 4; Dipeptidyl-Peptidase IV Inhibitors; Glucagon-Like Peptide 1; Glucose; Homeostasis; Humans; Hypoglycemia; Hypoglycemic Agents; Insulin; Myocardial Ischemia | 2023 |
Clinical Impact of Glucagon-Like Peptide-1 Receptor Analogs on the Complications of Obesity.
Obesity is a chronic disease associated with increased morbidity and mortality due to its complications. The aims of obesity treatment are primarily to accomplish weight loss, and prevention or treatment of its complications. Lifestyle changes along with behavioral therapy constitute the first-line treatment of obesity followed by pharmacotherapy. Glucagon-like peptide receptor analogs (GLP-1 RAs) are among the approved pharmacotherapy options. Their central effect on suppressing appetite results in considerable weight loss. However, their effect on the complications of obesity has not been very well recognized. This review aims to analyze the effects of GLP-1 RAs on the complications of obesity, as diabetes mellitus, hypertension, nonalcoholic steatohepatitis (NASH), cardiovascular diseases, polycystic ovary syndrome, infertility, obstructive sleep apnea (OSA), osteoarthritis, cancer and central nervous system problems.. Data from preclinical studies and clinical trials have been thoroughly evaluated. Effects regarding the complications as far as the scope of this review have covered can be summarized as blood glucose lowering, blood pressure lowering, resolution of NASH, improving major cardiovascular events, improving fertility and sex hormone levels, and improvement in OSA symptoms and in cognitive scores. Although the mechanisms are not fully elucidated, it is clear that the effects are not solely due to weight loss, but some pleiotropic effects like decreased inflammation, oxidative stress, and fibrosis also play a role in some of the complications.. Treating obesity is not only enabling weight loss but ameliorating complications related to obesity. Thus, any antiobesity medication has to have some favorable effects on the complications. As far as the GLP-RA's analogs are concerned, there seems to be an improvement in many of the complications regardless of the weight loss effect of these medications. Topics: Diabetes Mellitus, Type 2; Female; Glucagon-Like Peptide 1; Glucagon-Like Peptide-1 Receptor; Humans; Hypoglycemic Agents; Non-alcoholic Fatty Liver Disease; Obesity; Weight Loss | 2023 |
The Gut-Bone Axis in Diabetes.
To describe recent advances in the understanding of how gut-derived hormones regulate bone homeostasis in humans with emphasis on pathophysiological and therapeutic perspectives in diabetes.. The gut-derived incretin hormone glucose-dependent insulinotropic polypeptide (GIP) is important for postprandial suppression of bone resorption. The other incretin hormone, glucagon-like peptide 1 (GLP-1), as well as the intestinotrophic glucagon-like peptide 2 (GLP-2) has been shown to suppress bone resorption in pharmacological concentrations, but the role of the endogenous hormones in bone homeostasis is uncertain. For ambiguous reasons, both patients with type 1 and type 2 diabetes have increased fracture risk. In diabetes, the suppressive effect of endogenous GIP on bone resorption seems preserved, while the effect of GLP-2 remains unexplored both pharmacologically and physiologically. GLP-1 receptor agonists, used for the treatment of type 2 diabetes and obesity, may reduce bone loss, but results are inconsistent. GIP is an important physiological suppressor of postprandial bone resorption, while GLP-1 and GLP-2 may also exert bone-preserving effects when used pharmacologically. A better understanding of the actions of these gut hormones on bone homeostasis in patients with diabetes may lead to new strategies for the prevention and treatment of skeletal frailty related to diabetes. Topics: Bone Resorption; Diabetes Mellitus, Type 2; Gastric Inhibitory Polypeptide; Gastrointestinal Hormones; Glucagon-Like Peptide 1; Glucagon-Like Peptide 2; Humans; Incretins | 2023 |
Effect of new glucose-lowering drugs on stroke in patients with type 2 diabetes: A systematic review and Meta-analysis.
People with diabetes tend to face a higher risk of stroke. Randomized controlled trials (RCTs) have demonstrated the different outcomes of new glucose-lowering drugs marketed in recent years on cardiovascular outcome events. The effects of glucagon-like peptide-1 (GLP-1) agonists, sodium-glucose cotransporter-2 (SGLT-2) inhibitors, and dipeptidyl peptidase-4 (DPP-4) inhibitors on stroke risk were evaluated in published RCTs.. A search of Embase, Cochrane Library, and PubMed databases identified studies with stroke as an outcome event up to 3 December 2021. Risk ratios for stroke outcomes were analyzed using a fixed-effects model. I. 19 RCTs with 155,027 participants with type 2 diabetes were identified. Pooled analysis showed that compared to placebo, GLP-1 agonists reduced non-fatal stroke by 15 % (RR = 0.85, 95%CI 0.77-0.94, P = 0.002, I. This meta-analysis indicates that GLP-1 agonists have potential benefits for stroke. However, further studies are needed if GLP-1 agonists are to be used to reduce the risk of stroke in patients with type 2 diabetes. More research is also needed to investigate the effects of new glucose-lowering drugs on different stroke subtypes.. This protocol was registered on the International Prospective Register of Systematic Reviews (https://www.crd.york.ac.uk/PROSPERO/; registration number: CRD42022326382). Topics: Diabetes Mellitus, Type 2; Dipeptidyl-Peptidase IV Inhibitors; Glucagon-Like Peptide 1; Glucagon-Like Peptide-1 Receptor; Glucose; Humans; Hypoglycemic Agents; Sodium-Glucose Transporter 2 Inhibitors; Stroke | 2023 |
Obesity pharmacotherapy: incretin action in the central nervous system.
The prevalence of obesity is rising, creating an urgent need for efficacious therapies. Recent clinical trials show that tirzepatide, a dual agonist of receptors for the incretin hormones glucagon-like peptide-1 (GLP-1) and glucose-dependent insulinotropic polypeptide (GIP), yields more weight loss than selective GLP-1 receptor (GLP-1R) agonists. Incretin receptors in the central nervous system (CNS) may contribute to these effects. Yet exactly how each receptor regulates body weight from within the CNS is not clearly understood. It remains especially unclear how GIP receptor (GIPR) signalling contributes to the effects of tirzepatide because both stimulation and inhibition of CNS GIPRs yield weight loss in preclinical models. We summarise current knowledge on CNS incretin receptor pharmacology to provide insight into the potential mechanisms of action of dual GIPR/GLP-1R agonists, with tirzepatide as the exemplar. In addition, we discuss recent developments in incretin-based dual- and tri-agonism for inducing weight loss in obese individuals. Topics: Diabetes Mellitus, Type 2; Glucagon-Like Peptide 1; Humans; Incretins; Obesity; Weight Loss | 2023 |
Glucagon-like peptide-1 secretion in people with versus without type 2 diabetes: a systematic review and meta-analysis of cross-sectional studies.
The aim of this systematic review was to synthesise the study findings on whether GLP-1 secretion in response to a meal tolerance test is affected by the presence of type 2 diabetes (T2D). The influence of putative moderators such as age, sex, meal type, meal form, and assay type were also explored.. A literature search identified 32 relevant studies. The sample mean and SD for fasting GLP-1. Pooled across 18 studies, the overall SMD in GLP-1. Differences in fasting GLP-1. CRD42020195612. Topics: Blood Glucose; Cross-Sectional Studies; Diabetes Mellitus, Type 2; Fasting; Glucagon; Glucagon-Like Peptide 1; Humans; Insulin | 2023 |
Beyond the pancreas: contrasting cardiometabolic actions of GIP and GLP1.
Glucose-dependent insulinotropic polypeptide (GIP) and glucagon-like peptide 1 (GLP1) exhibit incretin activity, meaning that they potentiate glucose-dependent insulin secretion. The emergence of GIP receptor (GIPR)-GLP1 receptor (GLP1R) co-agonists has fostered growing interest in the actions of GIP and GLP1 in metabolically relevant tissues. Here, we update concepts of how these hormones act beyond the pancreas. The actions of GIP and GLP1 on liver, muscle and adipose tissue, in the control of glucose and lipid homeostasis, are discussed in the context of plausible mechanisms of action. Both the GIPR and GLP1R are expressed in the central nervous system, wherein receptor activation produces anorectic effects enabling weight loss. In preclinical studies, GIP and GLP1 reduce atherosclerosis. Furthermore, GIPR and GLP1R are expressed within the heart and immune system, and GLP1R within the kidney, revealing putative mechanisms linking GIP and GLP1R agonism to cardiorenal protection. We interpret the clinical and mechanistic data obtained for different agents that enable weight loss and glucose control for the treatment of obesity and type 2 diabetes mellitus, respectively, by activating or blocking GIPR signalling, including the GIPR-GLP1R co-agonist tirzepatide, as well as the GIPR antagonist-GLP1R agonist AMG-133. Collectively, we update translational concepts of GIP and GLP1 action, while highlighting gaps, areas of uncertainty and controversies meriting ongoing investigation. Topics: Cardiovascular Diseases; Diabetes Mellitus, Type 2; Gastric Inhibitory Polypeptide; Glucagon-Like Peptide 1; Glucose; Humans; Pancreas; Receptors, G-Protein-Coupled; Weight Loss | 2023 |
GLP-1 Agonists for Weight Loss: Pharmacology and Clinical Implications.
This review investigates the various pharmacologic treatments for overweight and obesity in adults, especially glucagon-like peptide 1 (GLP-1) agonists. In light of the globally expanding obesity pandemic and the limited selection of treatments, physicians must be equipped with knowledge regarding proven medications and their nuanced differences to best support patients on their path to a healthier lifestyle. In this review, we explore the current medical therapies for obesity, including all major categories, individual mechanisms of action, pharmacokinetics and pharmacodynamics, adverse effects, risks, and absolute contraindications. Additionally, we review the evidence of four recent clinical trials, two systematic reviews, and two meta-analyses describing the efficacy of GLP-1 agonists in decreasing weight, lowering HbA1c, and improving obesity comorbidities. We also discuss total cost and cost-effectiveness compared to other categories, long-term adherence, barriers to use, and reasons for discontinuation of this drug category. Our goal is that this review can serve as a framework to aid providers in building their knowledge and selecting the most advantageous weight loss medication for each patient. Topics: Adult; Diabetes Mellitus, Type 2; Glucagon-Like Peptide 1; Glucagon-Like Peptide-1 Receptor; Humans; Hypoglycemic Agents; Obesity; Overweight; Weight Loss | 2023 |
Glucagon, from past to present: a century of intensive research and controversies.
2022 corresponds to the 100th anniversary of the discovery of glucagon. This TimeCapsule aims to recall the main steps leading to the discovery, characterisation, and clinical importance of the so-called second pancreatic hormone. We describe the early historical findings in basic research (ie, discovery, purification, structure, α-cell origin, radioimmunoassay, glucagon gene [GCG], and glucagon receptor [GLR]), in which three future Nobel Prize laureates were actively involved. Considered as an anti-insulin hormone, glucagon was rapidly used to treat insulin-induced hypoglycaemic coma episodes in people with type 1 diabetes. A key step in the story of glucagon was the discovery of its role and the role of α cells in the physiology and pathophysiology (ie, paracrinopathy) of type 2 diabetes. This concept led to the design of different strategies targeting glucagon, among which GLP-1 receptor (GLP1R) agonists were a major breakthrough, and combination of inhibition of glucagon secretion with stimulation of insulin secretion (both in a glucose-dependent manner). Taking advantage of the glucagon-induced increase in energy metabolism, biased coagonists were developed. Besides the GLP-1 receptor, these coagonists also target the glucagon receptor to further promote weight loss. Thus, the 100-year story of glucagon has most probably not come to an end. Topics: Diabetes Mellitus, Type 2; Glucagon; Glucagon-Like Peptide 1; Glucagon-Like Peptide-1 Receptor; Humans; Hypoglycemia; Receptors, Glucagon | 2023 |
Glucagon-like peptide 1-receptor agonists and A1c: Good for the heart but less so for the eyes?
Glucagon-like peptide1-receptor agonists (GLP1-RA) decrease major adverse cardiovascular events (MACE) in people with type 2 diabetes mellitus and cardiovascular disease (CVD). Caution is recommended for semaglutide and dulaglutide with risk of exacerbating diabetic retinopathy (DR). Analyses were performed to determine if worsening of DR was dependent on drug class or fall in A1c.. Meta-analyses and meta-regressions (MR) were performed on the 7 major cardiovascular outcome trial (CVOTs) (n = 56004 patients) of GLP1-RA. A second analysis of 11 studies (n = 11894 subjects) with semaglutide documenting DR followed.. Six of the CVOTs evaluated DR. For the GLP1-RA class, there was no increase in the relative rate (rr) for retinopathy (rr = 1.09,95%CI; 0.925,1.289, p = 0.30), with only an increase with parenteral semaglutide (rr = 1.73; 1.10:2.71, p = 0.02). MR showed that decreases in A1c correlated with decreases in MACE (log rr = 0.364∗(Δ A1c), p = 0.014), but increases in DR (log rr= (-0.67∗(ΔA1c), p = 0.076). The change in DR was predominantly found for subcutaneous semaglutide given for >1 year (rr = 1.559,1.068,2.276, p = 0.022) and with decreases in A1c > 1.0% (rr = 1.59; 1.092,2.316, p = 0.016). For the class of GLP1-RA, the rate difference (rd) for worsening retinopathy was = 0.001 (and number needed to harm [NNH] = 1000) compared with rd for MACE = -0.013 (number needed to treat [NNT] = 77). The computation for semaglutide was NNH = 77 and NNT = 43.. This meta-analysis may assist in decisions balancing the relative risk (of existing retinopathy) versus benefits (to existing CVD). There should be close collaboration with ophthalmology to grade the baseline degree of retinopathy when initiating and following patients. Topics: Cardiovascular Diseases; Diabetes Mellitus, Type 2; Diabetic Retinopathy; Glucagon-Like Peptide 1; Glucagon-Like Peptide-1 Receptor; Glycated Hemoglobin; Humans; Hypoglycemic Agents | 2023 |
[Gastrointestinal hormones: their increasing pharmacotherapeutic relevance in metabolic diseases].
Gastrointestinal hormones play an important role in the endocrine communication between the intestine, the pancreas, the liver and the brain. Glucagon-like peptide‑1 receptor agonists (GLP-1RA) are established therapeutic agents in the treatment of type‑2 diabetes. Multiple agonists acting as ligands on various gastrointestinal hormone receptors are a novel pharmacological development. In addition to glucagon-like peptide 1 (GLP-1), these multiple agonists also have glucose-dependent insulinotropic polypeptide (GIP) and/or glucagon receptors as target structures for their pharmacological action. The multiple agonist action is designed to increase glycaemic effects as well as the effects on body weight. This article provides an overview of GLP-1RA and the multiple agonists. Among the dual agonists, the GIP/GLP-1-agonist tirzeptide has been approved for the treatment of type‑2 diabetes, and clinical studies with tirzepatide as a treatment for obesity are ongoing. The currently available data on studies with GLP-1/glucagon agonists and triple agonists are also summarized.. Gastrointestinale Hormone nehmen eine wichtige Rolle in der endokrinen Kommunikation zwischen Darm, Pankreas, Leber und Gehirn ein. Glucagon-like-peptide-1-Rezeptor-Agonisten (GLP-1RA) sind als Therapeutika bei Diabetes mellitus Typ 2 mittlerweile fest etabliert. Eine pharmakologische Weiterentwicklung sind die multiplen Agonisten, die als Liganden an mehreren Darmhormonrezeptoren fungieren. Zielstrukturen für die Wirkung sind hier neben „glucagon-like peptide 1“ (GLP-1) die Rezeptoren von „glucose-dependent insulinotropic polypeptide“ (GIP) und Glukagon. Durch die multiple Agonistenwirkung sollen glykämische Wirkungen und Effekte auf das Körpergewicht verstärkt werden. Der vorliegende Beitrag gibt eine Übersicht über GLP-1RA und die multiplen Agonisten. Unter den dualen Agonisten hat der GIP/GLP-1-Agonist Tirzepatid mittlerweile eine Zulassung zur Behandlung des Typ-2-Diabetes. Klinische Zulassungsstudien zum Einsatz von Tirzepatid bei Adipositas werden derzeit durchgeführt. Die aktuellen Daten aus Studien zu GLP-1/Glukagon-Agonisten und Dreifachagonisten werden hier ebenfalls zusammengefasst. Topics: Diabetes Mellitus, Type 2; Gastrointestinal Hormones; Glucagon; Glucagon-Like Peptide 1; Humans; Incretins | 2023 |
An update on peptide-based therapies for type 2 diabetes and obesity.
Long-acting analogues of the naturally occurring incretin, glucagon-like peptide-1 (GLP-1) and those modified to interact also with receptors for glucose-dependent insulinotropic polypeptide (GIP) have shown high glucose-lowering and weight-lowering efficacy when administered by once-weekly subcutaneous injection. These analogues herald an exciting new era in peptide-based therapy for type 2 diabetes (T2D) and obesity. Of note is the GLP-1R agonist semaglutide, available in oral and injectable formulations and in clinical trials combined with the long-acting amylin analogue, cagrilintide. Particularly high efficacy in both glucose- and weight lowering capacities has also been observed with the GLP-1R/GIP-R unimolecular dual agonist, tirzepatide. In addition, a number of long-acting unimolecular GLP-1R/GCGR dual agonist peptides and GLP-1R/GCGR/GIPR triagonist peptides have entered clinical trials. Other pharmacological approaches to chronic weight management include the human monoclonal antibody, bimagrumab which blocks activin type II receptors and is associated with growth of skeletal muscle, an antibody blocking activation of GIPR to which are conjugated GLP-1R peptide agonists (AMG-133), and the melanocortin-4 receptor agonist, setmelanotide for use in certain inherited obesity conditions. The high global demand for the GLP-1R agonists liraglutide and semaglutide as anti-obesity agents has led to shortage so that their use in T2D therapy is currently being prioritized. Topics: Diabetes Mellitus, Type 2; Gastric Inhibitory Polypeptide; Glucagon-Like Peptide 1; Glucagon-Like Peptide-1 Receptor; Glucose; Humans; Incretins; Obesity | 2023 |
Impact of Glucagon-like peptide 1 receptor agonists on peripheral arterial disease in people with diabetes mellitus: A narrative review.
Peripheral arterial disease (PAD) is a common macrovascular complication of diabetes mellitus (DM). Glucagon-like peptide 1 (GLP-1) receptor agonists (GLP-1RAs) are among the latest class of antidiabetic medications that stimulate insulin synthesis and secretion and have been used for the management of type 2 DM. Apart from the effect on glycaemic control, GLP-1RAs also have a robust impact on weight reduction and have shown favorable effects on cardiovascular morbidity and mortality in cardiovascular outcome trials (CVOTs). The aim of this review was to examine the impact of GLP1-RAs on PAD among people with DM based on CVOTs, randomized controlled trials, observational studies as well as systematic reviews and meta-analyses. Data from retrospective studies and meta-analyses have shown superiority of these agents in comparison with other antidiabetic medications such as sodium-glucose cotransporter type 2 inhibitors and dipeptidyl peptidase-4 inhibitors in terms of PAD-related events. Nevertheless, data from CVOTs regarding the impact of GLP-1RAs on PAD are scarce and hence, safe conclusions regarding their effects cannot be drawn. Further prospective studies are needed to examine the impact of GLP-1RAs on PAD-related incidents including major adverse limb events, lower limb amputations and revascularization procedures. Topics: Cardiovascular Diseases; Diabetes Mellitus, Type 2; Glucagon-Like Peptide 1; Glucagon-Like Peptide-1 Receptor; Humans; Hypoglycemic Agents; Peripheral Arterial Disease; Retrospective Studies | 2023 |
Mechanisms and possible hepatoprotective effects of glucagon-like peptide-1 receptor agonists and other incretin receptor agonists in non-alcoholic fatty liver disease.
Glucagon-like peptide-1 (GLP-1) and glucose-dependent insulinotropic polypeptide (GIP) are incretins that stimulate insulin secretion from pancreatic β cells in response to food ingestion. Modified GLP-1 and GIP peptides are potent agonists for their incretin receptors, and some evidence shows that the dual GLP-1 and GIP receptor agonist tirzepatide is effective in promoting marked weight loss. GLP-1 receptor agonists signal in the CNS to suppress appetite, increase satiety, and thereby decrease calorie intake, but many other effects of incretin signalling have been recognised that are relevant to the treatment of non-alcoholic fatty liver disease (NAFLD). This Review provides an overview of the literature supporting the notion that endogenous incretins and incretin-receptor agonist treatments are important not only for decreasing risk of developing NAFLD, but also for treating NAFLD and NAFLD-related complications. We discuss incretin signalling and related incretin-receptor agonist treatments, mechanisms in key relevant tissues affecting liver disease, and clinical data from randomised controlled trials. Finally, we present future perspectives in this rapidly developing field of research and clinical medicine. Topics: Diabetes Mellitus, Type 2; Glucagon-Like Peptide 1; Glucagon-Like Peptide-1 Receptor; Humans; Incretins; Non-alcoholic Fatty Liver Disease | 2023 |
Dual GIP/GLP-1 receptor agonists: New advances for treating type-2 diabetes.
Glucagon-like peptide-1 (GLP-1) receptor agonists currently occupy a privileged place in the management of type-2 diabetes (T2D). Dual glucose-dependent insulinotropic polypeptides (GIP/GLP-1) have been recently developed. Tirzepatide is the most advanced unimolecular dual GIP/GLP-1 receptor agonist to be used as once weekly subcutaneous injection in T2D and recently received approval by the European Medicines Agency. Because of the complementarity of action of the two incretins, tirzepatide showed better dose-dependent (5, 10 and 15mg) efficacy (greater reduction in HbA1c and body weight) than placebo, basal insulin or two GLP-1 analogues (dulaglutide and semaglutide) in the SURPASS program. Its cardiovascular protective effect is currently being assessed versus dulaglutide in the SURPASS-CVOT study. Finally, studies for the treatment of obesity (SURMOUNT program) and metabolic-associated fatty liver disease (MAFLD) are also ongoing. Gastrointestinal tolerance of tirzepatide appears comparable to that of GLP-1 analogues, except for higher incidence of diarrhea. Other original molecules have been built, including triple GIP/GLP-1/glucagon receptor agonists. The risk/benefit ratio will decide whether dual (or triple) receptor agonists should replace pure GLP-1 receptor agonists for the management of T2D in the near future, with a significant role in the pharmacotherapy of obesity. Topics: Diabetes Mellitus, Type 2; Glucagon-Like Peptide 1; Glucagon-Like Peptide-1 Receptor; Humans; Hypoglycemic Agents; Incretins; Obesity | 2023 |
Emerging roles of oxyntomodulin-based glucagon-like peptide-1/glucagon co-agonist analogs in diabetes and obesity.
Oxyntomodulin (OXM) is an endogenous peptide hormone secreted from the intestines following nutrient ingestion that activates both glucagon-like peptide-1 (GLP-1) and glucagon receptors. OXM is known to exert various effects, including improvement in glucose tolerance, promotion of energy expenditure, acceleration of liver lipolysis, inhibition of food intake, delay of gastric emptying, neuroprotection, and pain relief. The antidiabetic and antiobesity properties have led to the development of biologically active and enzymatically stable OXM-based analogs with proposed therapeutic promise for metabolic diseases. Structural modification of OXM was ongoing to enhance its potency and prolong half-life, and several GLP-1/glucagon dual receptor agonist-based therapies are being explored in clinical trials for the treatment of type 2 diabetes mellitus and its complications. In the present article, we provide a brief overview of the physiology of OXM, focusing on its structural-activity relationship and ongoing clinical development. Topics: Diabetes Mellitus, Type 2; Glucagon; Glucagon-Like Peptide 1; Glucagon-Like Peptide-1 Receptor; Humans; Obesity; Oxyntomodulin | 2023 |
GLP-1 Receptor Agonists in Non-Alcoholic Fatty Liver Disease: Current Evidence and Future Perspectives.
To date, non-alcoholic fatty liver disease (NAFLD) is the most frequent liver disease, affecting up to 70% of patients with diabetes. Currently, there are no specific drugs available for its treatment. Beyond their anti-hyperglycemic effect and the surprising role of cardio- and nephroprotection, GLP-1 receptor agonists (GLP-1 RAs) have shown a significant impact on body weight and clinical, biochemical and histological markers of fatty liver and fibrosis in patients with NAFLD. Therefore, GLP-1 RAs could be a weapon for the treatment of both diabetes mellitus and NAFLD. The aim of this review is to summarize the evidence currently available on the role of GLP-1 RAs in the treatment of NAFLD and to hypothesize potential future scenarios. Topics: Diabetes Mellitus, Type 2; Glucagon-Like Peptide 1; Glucagon-Like Peptide-1 Receptor; Humans; Liver; Non-alcoholic Fatty Liver Disease | 2023 |
The Safety and Efficacy of GLP-1 Receptor Agonists in Heart Failure Patients: A Systematic Review and Meta-Analysis.
Evaluation of glucagon-like peptide-1 receptor agonists (GLP-1 RAs) usage in heart failure (HF) patients with or without type 2 diabetes mellitus (T2DM) could be proven to be a critical breakthrough in treatment options available for these patients. Our study focuses on understanding the safety and efficacy of GLP-1 RAs in this patient population by pooling the data from 9 randomized controlled trials (RCTs) comprising 871 subjects. As compared with the placebo, GLP-1 RAs did not improve major adverse cardiovascular events (MACE) which include cardiovascular (CV) mortality and heart failure (HF) hospitalizations, our primary outcome. CV mortality (RR = 1.03, 95% CI = 0.56-1.88, P = 0.92) and HF hospitalizations (RR = 1.18, 95%CI = 0.93-1.51, P = 0.18). Similarly, GLP-1 RAs did not improve our secondary findings of left ventricular ejection fraction (LVEF) and 6-minute walk test (6MWT). LVEF (RR = 1.96, 95%CI = -0.16-4.07, P = 0.07) or 6 MWT (RR = 8.43, 95% CI = -2.69-19.56, P = 0.14). This meta-analysis shows that GLP-1 RAs do not improve cardiovascular outcomes in HF patients with or without T2DM. Topics: Cardiovascular Diseases; Diabetes Mellitus, Type 2; Glucagon-Like Peptide 1; Glucagon-Like Peptide-1 Receptor; Heart Failure; Humans; Hypoglycemic Agents; Randomized Controlled Trials as Topic | 2023 |
Comparative efficacy of glucagon-like peptide 1 (GLP-1) receptor agonists, pioglitazone and vitamin E for liver histology among patients with nonalcoholic fatty liver disease: systematic review and pilot network meta-analysis of randomized controlled tria
There is no conclusive evidence comparing the efficacy of glucagon-like peptide 1 (GLP-1) receptor agonists to the other guidelines recommended pharmacotherapy for nonalcoholic fatty liver disease (NAFLD). Therefore, we aim to compare the effects of GLP-1 receptor agonists, pioglitazone and vitamin E in patients with NAFLD.. We searched PubMed, Embase, Web of Science and Cochrane Library up to 11 April 2022. Randomized clinical trials (RCTs) comparing GLP-1 receptor agonists, pioglitazone and vitamin E against placebo or other active controls in patients with NAFLD were included.. Nine RCTs including 1482 patients proved eligible. GLP-1 receptor agonists ranked first in steatosis, ballooning necrosis, γ-glutamyl transferase, body weight, body mass index, and triglycerides. Administration of GLP-1 receptor agonists, as compared with placebo, was associated with improvement in liver histology [steatosis (OR = 4.11, 95% CI: 2.83, 5.96), ballooning necrosis (OR = 3.07, 95% CI: 2.14, 4.41), lobular inflammation (OR = 1.86, 95% CI: 1.29, 2.68), fibrosis (OR = 1.52, 95% CI: 1.06, 2.20)].. GLP-1 receptor agonists were as effective as pioglitazone and vitamin E for liver histology among patients with NAFLD. GLP-1 receptor agonists might be considered as an alternative or complementary treatment in the future clinical practice. [Figure: see text]. Topics: Diabetes Mellitus, Type 2; Glucagon-Like Peptide 1; Glucagon-Like Peptide-1 Receptor; Humans; Hypoglycemic Agents; Necrosis; Network Meta-Analysis; Non-alcoholic Fatty Liver Disease; Pilot Projects; Pioglitazone; Randomized Controlled Trials as Topic; Vitamin E | 2023 |
Glucometabolic Perturbations in Type 2 Diabetes Mellitus and Coronavirus Disease 2019: Causes, Consequences, and How to Counter Them Using Novel Antidiabetic Drugs - The CAPISCO International Expert Panel.
The growing amount of evidence suggests the existence of a bidirectional relation between coronavirus disease 2019 (COVID-19) and type 2 diabetes mellitus (T2DM), as these two conditions exacerbate each other, causing a significant healthcare and socioeconomic burden. The alterations in innate and adaptive cellular immunity, adipose tissue, alveolar and endothelial dysfunction, hypercoagulation, the propensity to an increased viral load, and chronic diabetic complications are all associated with glucometabolic perturbations of T2DM patients that predispose them to severe forms of COVID-19 and mortality. Severe acute respiratory syndrome coronavirus 2 infection negatively impacts glucose homeostasis due to its effects on insulin sensitivity and β-cell function, further aggravating the preexisting glucometabolic perturbations in individuals with T2DM. Thus, the most effective ways are urgently needed for countering these glucometabolic disturbances occurring during acute COVID-19 illness in T2DM patients. The novel classes of antidiabetic medications (dipeptidyl peptidase 4 inhibitors (DPP-4is), glucagon-like peptide-1 receptor agonists (GLP-1 RAs), and sodium-glucose co-transporter-2 inhibitors (SGLT-2is) are considered candidate drugs for this purpose. This review article summarizes current knowledge regarding glucometabolic disturbances during acute COVID-19 illness in T2DM patients and the potential ways to tackle them using novel antidiabetic medications. Recent observational data suggest that preadmission use of GLP-1 RAs and SGLT-2is are associated with decreased patient mortality, while DPP-4is is associated with increased in-hospital mortality of T2DM patients with COVID-19. Although these results provide further evidence for the widespread use of these two classes of medications in this COVID-19 era, dedicated randomized controlled trials analyzing the effects of in-hospital use of novel antidiabetic agents in T2DM patients with COVID-19 are needed. Topics: COVID-19; Diabetes Mellitus, Type 2; Dipeptidyl-Peptidase IV Inhibitors; Glucagon-Like Peptide 1; Glucose; Humans; Hypoglycemic Agents; Sodium-Glucose Transporter 2 Inhibitors | 2023 |
How dietary amino acids and high protein diets influence insulin secretion.
Glucose homeostasis is the maintenance and regulation of blood glucose concentration within a tight physiological range, essential for the functioning of most tissues and organs. This is primarily achieved by pancreatic secretion of insulin and glucagon. Deficient pancreatic endocrine function, coupled with or without peripheral insulin resistance leads to prolonged hyperglycemia with chronic impairment of glucose homeostasis, most commonly seen in diabetes mellitus. High protein diets (HPDs) are thought to modulate glucose homeostasis through various metabolic pathways. Insulin secretion can be directly modulated by the amino acid products of protein digestion, which activate nutrient receptors and nutrient transporters expressed by the endocrine pancreas. Insulin secretion can also be modulated indirectly, through incretin release from enteroendocrine cells, and via vagal neuronal pathways. Additionally, glucose homeostasis can be promoted by the satiating effects of anorectic hormones released following HPD consumption. This review summarizes the insulinotropic mechanisms by which amino acids and HPDs may influence glucose homeostasis, with a particular focus on their applicability in the management of Type 2 diabetes mellitus. Topics: Amino Acids; Diabetes Mellitus, Type 2; Diet, High-Protein; Glucagon-Like Peptide 1; Glucose; Humans; Insulin; Insulin Secretion | 2023 |
Effect of glucagon-like peptide-1 receptor agonists on glycemic control, and weight reduction in adults: A multivariate meta-analysis.
To explore the effect of glucagon-like peptide-1 receptor agonist (GLP-1 RAs) on glycemic control and weight reduction in adults.. Databases were searched from August 2021 to March 2022. Data were analyzed using mean difference (MD) values with 95% confidence intervals (CIs). Both random-and fixed-effect models were employed. Heterogeneity was explored using pre-specified subgroup analyses and meta-regression. Structural equation modeling fitting was used for the multivariate meta-analysis.. A total of 31 double-blind randomized controlled trials with 22,948 participants were included in the meta-analysis. The MD and 95% CI of the pooled GLP1-RA-induced change in the glycated hemoglobin level was -0.78% (-0.97%, -0.60%) in the random-effects model and -0.45% (-0.47%, -0.44%) in the fixed-effect model, with a high heterogeneity (I2 = 97%). The pooled body weight reduction was -4.05 kg (-5.02 kg, -3.09 kg) in the random-effects model and -2.04 kg (-2.16 kg, -1.92 kg) in the fixed-effect model (I2 = 98%). The standardized pooled correlation coefficient between HbA1c levels and body weight was -0.42. A negative correlation between glycemic control and weight reduction was obtained.. Long-acting GLP-1 RAs significantly reduced the glycated hemoglobin level and body weight in adults. Topics: Adult; Body Weight; Diabetes Mellitus, Type 2; Glucagon-Like Peptide 1; Glucagon-Like Peptide-1 Receptor; Glycated Hemoglobin; Glycemic Control; Humans; Hypoglycemic Agents; Randomized Controlled Trials as Topic; Weight Loss | 2023 |
Real-world clinical effectiveness of once-weekly semaglutide in patients with type 2 diabetes: a systematic literature review.
The efficacy of once-weekly (O.W.) semaglutide for the treatment of type 2 diabetes mellitus (T2DM) has been demonstrated in clinical trials. The aim of this systematic literature review was to summarize real-world evidence for O.W. semaglutide.. A comprehensive search of PubMed, Web of Science, Embase, and Scilit databases was performed from January 2017 to June 2022 to identify eligible real-world studies examining O.W. semaglutide in T2DM.. Thirty-one records (18 full-text and 13 abstracts) were identified. The general characteristics of studies and included patients were summarized. Changes in glycated hemoglobin (HbA1c) and body weight were analyzed across studies and according to patient characteristics: baseline HbA1c/weight level, GLP-1 RA-naïve/ GLP-1RA-experienced. The effectiveness of O.W. semaglutide compared with dulaglutide, and the dose of O.W. semaglutide in the real world were also summarized.. This systematic literature review provided complementary evidence to findings from the clinical trials and provided a more comprehensive picture of the use of O.W. semaglutide in routine clinical practice. Results of the review suggested that O.W. semaglutide therapy was associated with improving glycemic control and weight loss in both T2DM patients naïve to GLP-1RA and those previously treated with other GLP-1RA in routine clinical practice.. CRD42022306164. Topics: Body Weight; Diabetes Mellitus, Type 2; Drug Administration Schedule; Glucagon-Like Peptide 1; Glucagon-Like Peptides; Glycated Hemoglobin; Humans; Hypoglycemic Agents; Treatment Outcome | 2023 |
New Frontiers in Obesity Treatment: GLP-1 and Nascent Nutrient-Stimulated Hormone-Based Therapeutics.
Nearly half of Americans are projected to have obesity by 2030, underscoring the pressing need for effective treatments. Glucagon-like peptide 1 receptor agonists (GLP-1 RAs) represent the first agents in a rapidly evolving, highly promising landscape of nascent hormone-based obesity therapeutics. With the understanding of the neurobiology of obesity rapidly expanding, these emerging entero-endocrine and endo-pancreatic agents combined or coformulated with GLP-1 RAs herald a new era of targeted, mechanism-based treatment of obesity. This article reviews GLP-1 RAs in the treatment of obesity and previews the imminent future of nutrient-stimulated hormone-based anti-obesity therapeutics. Topics: Diabetes Mellitus, Type 2; Glucagon-Like Peptide 1; Humans; Hypoglycemic Agents; Obesity; Treatment Outcome | 2023 |
Glucagon-like peptide 1 receptor agonists in patients with type 2 diabetes with and without chronic heart failure: A meta-analysis of randomized placebo-controlled outcome trials.
Glucagon-like peptide 1 receptor agonists (GLP1-RA) reduce atherosclerotic events in patients with type 2 diabetes (T2D) and a high cardiovascular risk. The effect of GLP1-RA to reduce heart failure (HF) has been inconsistent across T2D trials, and individual trials were underpowered to assess the effect of GLP1-RA according to HF history. In this meta-analysis we aim to assess the effect of GLP1-RA in patients with and without HF history in stable ambulatory patients with T2D.. Random-effects meta-analysis of placebo-controlled trials. The hazard ratio (HR) and 95% confidence intervals (95% CI) were extracted from the treatment effect estimates of HF subgroup analyses reported in each individual study. The primary outcome was a composite of HF hospitalization or cardiovascular death.. In total, 54 092 patients with T2D from seven randomized controlled trials were included, of whom 8460 (16%) had HF history. Compared with placebo, GLP1-RA did not reduce the composite of HF hospitalization or cardiovascular death in patients with HF history: HR 0.96, 95% CI: 0.84-1.08, but reduced this outcome in patients without HF history: HR 0.84, 95% CI: 0.76-0.92. GLP1-RA did not reduce all-cause death in patients with HF history: HR 0.98, 95% CI: 0.86-1.11, but reduced mortality in patients without HF history: HR 0.85, 95% CI: 0.79-0.92. GLP1-RA reduced atherosclerotic events regardless of HF history: HR 0.85, 95% CI: 0.75-0.97 with HF, and HR 0.88, 95% CI: 0.83-0.93 without HF.. Treatment with GLP1-RA did not reduce HF hospitalizations and mortality in patients with concomitant T2D and HF, but may prevent new-onset HF and mortality in patients with T2D without HF. The reduction of atherosclerotic events with GLP1-RA was not influenced by HF history status. Topics: Atherosclerosis; Cardiovascular System; Diabetes Mellitus, Type 2; Glucagon-Like Peptide 1; Heart Failure; Humans; Hypoglycemic Agents; Randomized Controlled Trials as Topic | 2023 |
[The "other" incretin - the therapeutic rediscovery of the glucose-dependent insulinotropic polypeptide].
Among the two incretins that strongly stimulate insulin secretion and are also involved in its physiological regulation in type 2 diabetes, glucagon-like peptide-1 (GLP1) has been the focus of interest for a long time, due to its retained - although reduced - secretagogue nature also in type 2 diabetes. Its receptor agonists were also included in the antidiabetic treatment toolkit. In the light of more recent studies, however, the "other" incretin, the glucose-dependent insulinotropic polypeptide (GIP) has also come into a different light. It turned out that by regulating glucagon and insulin production according to blood sugar levels, it acts as a bifunctional blood sugar stabilizing factor in type 2 diabetes as well. The article reviews new data on the physiology of GIP, its verifiable effects in type 2 diabetes and obesity, the so-called "twincretin" effect as well as the benefits of the double stimulation of the GIP and the GLP1 receptor. It describes the pharmacology of the first dual receptor agonist, tirzepatide, already incorporated in therapeutic recommendations, and the first clinical trials related to its use. In the light of the data so far, the molecule may open new horizons in the treatment of type 2 diabetes and obesity. Orv Hetil. 2023; 164(6): 210-218.. Az inzulinszekréciót erélyesen serkentő, élettani szabályozásában is részt vevő két inkretin közül a 2-es típusú diabetesben is megtartott – bár csökkent − secretagog természete folytán hosszú időn keresztül a glükagonszerű peptid-1 (GLP1) került az érdeklődés előterébe, kívülről bejuttatott receptoragonistái bekerültek az antidiabetikus kezelés eszköztárába is. Újabb vizsgálatok fényében a „másik” inkretin, a glükózdependens insulinotrop polipeptid (GIP) is más megvilágításba került. Kiderült, hogy a glükagon és az inzulintermelés vércukorszinthez igazodó szabályozásával bifunkcionális vércukor-stabilizáló tényezőként viselkedik 2-es típusú diabetesben is. A közlemény áttekinti a GIP élettanával kapcsolatos új adatokat, 2-es típusú diabetesben és elhízásban igazolható hatásait, a „twincretin” hatás, a GIP és a GLP1-receptor kettős stimulálásának előnyeit. Ismerteti az első, már terápiás ajánlásokban is megjelent duális receptoragonista, a tirzepatid farmakológiáját és az alkalmazásával kapcsolatos első klinikai vizsgálatokat. A molekula az eddigi adatok tükrében új távlatokat jelenthet a 2-es típusú diabetes és az elhízás kezelésében. Orv Hetil. 2023; 164(6): 210–218. Topics: Blood Glucose; Diabetes Mellitus, Type 2; Gastric Inhibitory Polypeptide; Glucagon-Like Peptide 1; Humans; Incretins; Obesity | 2023 |
Incretin and Pancreatic β-Cell Function in Patients with Type 2 Diabetes.
To maintain normal glucose homeostasis after a meal, it is essential to secrete an adequate amount of insulin from pancreatic β-cells. However, if pancreatic β-cells solely depended on the blood glucose level for insulin secretion, a surge in blood glucose levels would be inevitable after the ingestion of a large amount of carbohydrates. To avoid a deluge of glucose in the bloodstream after a large carbohydrate- rich meal, enteroendocrine cells detect the amount of nutrient absorption from the gut lumen and secrete incretin hormones at scale. Since insulin secretion in response to incretin hormones occurs only in a hyperglycemic milieu, pancreatic β-cells can secrete a "Goldilocks" amount of insulin (i.e., not too much and not too little) to keep the blood glucose level in the normal range. In this regard, pancreatic β-cell sensitivity to glucose and incretin hormones is crucial for maintaining normal glucose homeostasis. In this Namgok lecture 2022, we review the effects of current anti-diabetic medications on pancreatic β-cell sensitivity to glucose and incretin hormones. Topics: Blood Glucose; Diabetes Mellitus, Type 2; Gastric Inhibitory Polypeptide; Glucagon-Like Peptide 1; Glucose; Humans; Incretins; Insulin | 2023 |
GLP-1 RAs in Spain: A Short Narrative Review of Their Use in Real Clinical Practice.
Glucagon-like peptide 1 receptor agonists (GLP-1 RAs) are a class of drugs with potent glucose-lowering activity. Additionally, some GLP-1 RAs have demonstrated cardiovascular and renal benefits. Current guidelines recommend their use in patients with type 2 diabetes (T2D) at high risk of or with established cardiovascular disease (CVD), regardless of glycaemic control, with lifestyle modification and metformin. However, several studies have recently highlighted the limited number of patients with T2D benefiting from these medications worldwide. Given the huge burden of CVD among patients with T2D, efforts should be made to bring clinical practice closer to expert guidelines. This review describes the current situation of GLP-1 RA use in Spain and the reasons behind the gap between guidelines and real-world practice and suggests possible solutions. Administrative issues, lack of awareness of the cardiovascular benefits, clinical inertia, rejection of injectable medication and costs could be some of the reasons for the current situation. Possible strategies that could help to close the gap include encouraging a multidisciplinary approach to the treatment of diabetes which involves cardiologists, endocrinologists, nephrologists, primary care providers and pharmacists; improved awareness of comorbidities and earlier evaluation and treatment or risks; and better education of healthcare providers regarding the cardioprotective benefits of these drugs.. The glucagon-like peptide 1 receptor agonists (GLP-1 RAs) are a class of drugs that can be beneficial for patients with type 2 diabetes who are at high risk of cardiovascular complications, such as heart attacks. For this reason, the current clinical guidelines strongly recommend their use in these patients. Unfortunately, many patients with type 2 diabetes and high cardiovascular risk still do not benefit from these drugs. This review analyses the reasons for this situation in Spain, and proposes some possible solutions. The reasons for the low use of GLP-1 RAs could be related to doctors not updating a patient’s diabetes medicine as often as they should, lack of awareness about the cardiovascular benefits of these drugs, fear of medicines that involve needles, administrative issues, and costs. Some of the possible strategies to improve the use of GLP-1 RAs among patients with type 2 diabetes with high cardiovascular risk could be to foster greater cooperation among specialists, increase awareness of the need to treat cardiovascular risk in patients with diabetes, and better education of doctors regarding the benefits of these drugs. Topics: Cardiovascular Diseases; Diabetes Mellitus, Type 2; Glucagon-Like Peptide 1; Glucagon-Like Peptide-1 Receptor; Humans; Hypoglycemic Agents; Spain | 2023 |
The Future of Diabetes Therapies: New Insulins and Insulin Delivery Systems, Glucagon-Like Peptide 1 Analogs, Sodium-Glucose Cotransporter Type 2 Inhibitors, and Beta Cell Replacement Therapy.
As the prevalence of diabetes mellitus increases, so too does the number of available treatment modalities. Many diabetic therapies available in human medicine or on the horizon could hold promise in the management of small animal diabetes. However, it is important to consider how species differences in pathophysiology, management practices and goals, and lifestyle may affect the translation of such treatment modalities for veterinary use. This review article aimed to familiarize veterinarians with the more promising novel diabetic therapies and explore their possible applications in the treatment of canine and feline diabetes mellitus. Topics: Animals; Cat Diseases; Cats; Diabetes Mellitus, Type 2; Dog Diseases; Dogs; Glucagon-Like Peptide 1; Glucose; Humans; Hypoglycemic Agents; Insulin; Sodium | 2023 |
The blood pressure lowering effects of glucagon-like peptide-1 receptor agonists: A mini-review of the potential mechanisms.
The incretin hormone glucagon-like peptide 1 (GLP-1) is a key component of the signaling mechanisms promoting glucose homeostasis. Clinical and experimental studies demonstrated that GLP-1 receptor agonists, including GLP-1 itself, have favorable effects on blood pressure and reduce the risk of major cardiovascular events, independently of their effect on glycemic control. GLP-1 receptors are present in the hypothalamus and brainstem, the carotid body, the vasculature, and the kidneys. These organs are involved in blood pressure regulation, have their function altered in hypertension, and are positively benefited by the treatment with GLP-1 receptor agonists. Here, we discuss the potential mechanisms whereby activation of GLP-1R signaling exerts blood pressure-lowering effects beyond glycemic control. Topics: Blood Pressure; Diabetes Mellitus, Type 2; Glucagon-Like Peptide 1; Glucagon-Like Peptide-1 Receptor; Humans; Incretins | 2023 |
Stroke Prevention and Treatment in People With Type 2 Diabetes: Is There a Role for GLP-1 (Glucagon-Like Peptide-1) Analogues?
Stroke is a leading cause of disability and death, and people with type 2 diabetes (T2D) have a greater risk of stroke and death or disability from stroke. The underlying pathophysiology associating stroke and T2D is complicated by the association of risk factors for stroke frequently seen in people with T2D. Treatments to reduce the excess risk of new-onset stroke or to improve outcomes in people with T2D following stroke would be of major clinical interest. In practice, the focus of care in people with T2D remains treating risk factors for stroke, such as lifestyle and pharmacological interventions for hypertension, dyslipidemia, obesity, and glycemic control. More recently, cardiovascular outcome trials primarily designed to assess the cardiovascular safety of GLP-1RAs (glucagon-like peptide-1 receptor analogues) have consistently observed a reduced stroke risk in people with T2D. This is supported by several meta-analyses of cardiovascular outcome trials observing clinically important risk reductions in stroke. Moreover, phase II trials have described reductions in poststroke hyperglycemia in people with acute ischemic stroke suggestive of improved outcomes following admission to hospital with acute stroke. In this review, we discuss the increased risk of stroke in people with T2D and outline the key associated mechanisms responsible. We discuss the evidence from cardiovascular outcome trials exploring GLP-1RA use and highlight areas of potential interest for future work in this rapidly developing area of clinical research. Topics: Cardiovascular Diseases; Diabetes Mellitus, Type 2; Glucagon-Like Peptide 1; Humans; Hypoglycemic Agents; Ischemic Stroke; Risk Factors | 2023 |
Use and Interchange of Incretin Mimetics in the Treatment of Metabolic Diseases: A Narrative Review.
Glucagon-like peptide 1 receptor agonists (GLP-1 RAs) and now tirzepatide, a dual GLP-1 RA/glucose-dependent insulinotropic polypeptide agonist, have numerous advantages in the treatment of type 2 diabetes and obesity, yet only 11% of patients with type 2 diabetes are prescribed a GLP-1 RA. This narrative review addresses the complexity and cost issues surrounding incretin mimetics to support clinicians.. This narrative review summarizes key trials on the differing effects of incretin mimetics on glycosylated hemoglobin and weight, provides a table with rationale for how to interchange among agents, and summarizes the key factors that guide drug selection beyond guidance from the American Diabetes Association. To support proposed dose interchanges, we preferentially selected high-quality, prospective randomized controlled trials with direct comparisons of agents and doses when available.. Tirzepatide produces the greatest reductions in glycosylated hemoglobin and weight, but its impact on cardiovascular events is still under investigation. Subcutaneous semaglutide and liraglutide are approved for weight loss specifically and are effective in the secondary prevention of cardiovascular disease. Although producing less weight loss, only dulaglutide has effectiveness in the primary and secondary prevention of cardiovascular disease. Semaglutide is the only orally available incretin mimetic; however, the oral formulation produces less weight loss versus its subcutaneous alternative and did not have cardioprotection in its outcomes trial. Although effective in controlling type 2 diabetes, exenatide extended release has the least impact on glycosylated hemoglobin and weight among commonly used agents, while not having cardioprotection. However, exenatide extended release may be preferred on some restrictive insurance formularies.. Although trials have not explicitly studied how to interchange among agents, interchanges can be guided by comparisons between agents' impact on glycosylated hemoglobin and weight. Efficient changes among agents can help clinicians optimize patient-centered care, particularly in the face of changing patient needs and preferences, insurance formularies, and drug shortages. Topics: Cardiovascular Diseases; Diabetes Mellitus, Type 2; Exenatide; Glucagon-Like Peptide 1; Glucagon-Like Peptide-1 Receptor; Glycated Hemoglobin; Humans; Hypoglycemic Agents; Incretins; Prospective Studies; Weight Loss | 2023 |
Weight-dependent and weight-independent effects of dulaglutide on blood pressure in patients with type 2 diabetes.
Patients with type 2 diabetes (T2D) treated with glucagon-like peptide-1 receptor agonists may experience reductions in weight and blood pressure. The primary objective of the current study was to determine the weight-dependent and weight-independent effects of ~ 6 months treatment with dulaglutide 1.5 mg treatment in participants with T2D.. Mediation analysis was conducted for five randomized, placebo-controlled trials of dulaglutide 1.5 mg to estimate the weight-dependent (i.e., mediated by weight) and weight-independent effects from dulaglutide vs. placebo on change from baseline for systolic blood pressure (SBP), diastolic blood pressure (DBP), and pulse pressure. A random-effects meta-analysis combined these results. To investigate a dose response between dulaglutide 4.5 mg and placebo, mediation analysis was first conducted in AWARD-11 to estimate the weight-dependent and weight-independent effects of dulaglutide 4.5 mg vs. 1.5 mg, followed by an indirect comparison with the mediation result for dulaglutide 1.5 mg vs. placebo.. Baseline characteristics were largely similar across the trials. In the mediation meta-analysis of placebo-controlled trials, the total treatment effect of dulaglutide 1.5 mg after placebo-adjustment on SBP was - 2.6 mmHg (95% CI - 3.8, - 1.5; p < 0.001) and was attributed to both a weight-dependent effect (- 0.9 mmHg; 95% CI: - 1.4, - 0.5; p < 0.001) and a weight-independent effect (- 1.5 mmHg; 95% CI: - 2.6, - 0.3; p = 0.01), accounting for 36% and 64% of the total effect, respectively. For pulse pressure, the total treatment effect of dulaglutide (- 2.5 mmHg; 95% CI: - 3.5, - 1.5; p < 0.001) was 14% weight-dependent and 86% weight-independent. For DBP there was limited impact of dulaglutide treatment, with only a small weight-mediated effect. Dulaglutide 4.5 mg demonstrated an effect on reduction in SBP and pulse pressure beyond that of dulaglutide 1.5 mg which was primarily weight mediated.. Dulaglutide 1.5 mg reduced SBP and pulse pressure in people with T2D across the placebo-controlled trials in the AWARD program. While up to one third of the effect of dulaglutide 1.5 mg on SBP and pulse pressure was due to weight reduction, the majority was independent of weight. A greater understanding of the pleotropic effects of GLP-1 RA that contribute to reduction in blood pressure could support developing future approaches for treating hypertension. Trial registrations (clinicaltrials.gov) NCT01064687, NCT00734474, NCT01769378, NCT02597049, NCT01149421, NCT03495102. Topics: Blood Pressure; Diabetes Mellitus, Type 2; Glucagon-Like Peptide 1; Glucagon-Like Peptides; Humans; Hypoglycemic Agents; Immunoglobulin Fc Fragments; Recombinant Fusion Proteins | 2023 |
GLP-1/GIP analogs: potential impact in the landscape of obesity pharmacotherapy.
Obesity is recognized as a major healthcare challenge. Following years of slow progress in discovery of safe, effective therapies for weight management, recent approval of the glucagon-like peptide 1 receptor (GLP-1R) mimetics, liraglutide and semaglutide, for obesity has generated considerable excitement. It is anticipated these agents will pave the way for application of tirzepatide, a highly effective glucose-dependent insulinotropic polypeptide receptor (GIPR), GLP-1R co-agonist, recently approved for management of type 2 diabetes mellitus.. Following promising weight loss in obese individuals in Phase III clinical trials, liraglutide and semaglutide were approved for weight management without diabetes. Tirzepatide has attained Fast Track designation for obesity management by the US Food and Drug Association. This narrative review summarizes experimental, preclinical, and clinical data for these agents and related GLP-1R/GIPR co-agonists, prioritizing clinical research published within the last 10 years where possible.. GLP-1R mimetics are often discontinued within 24 months meaning long-term application of these agents in obesity is questioned. Combined GIPR/GLP-1R agonism appears to induce fewer side effects, indicating GLP-1R/GIPR co-agonists may be more suitable for enduring obesity management. After years of debate, this GIPR-biased GLP-1R/GIPR co-agonist highlights the therapeutic promise of including GIPR modulation for diabetes and obesity therapy. Topics: Diabetes Mellitus, Type 2; Gastric Inhibitory Polypeptide; Glucagon-Like Peptide 1; Glucagon-Like Peptide-1 Receptor; Humans; Liraglutide; Obesity | 2023 |
Effect of glucagon-like peptide-1 receptor agonists administration during coronary artery bypass grafting: a systematic review and meta-analysis of randomized control trials.
Topics: Blood Glucose; Coronary Artery Bypass; Diabetes Mellitus, Type 2; Exenatide; Glucagon-Like Peptide 1; Glucagon-Like Peptide-1 Receptor; Glycated Hemoglobin; Humans; Hypoglycemic Agents; Insulin; Peptides; Venoms | 2023 |
The expanding incretin universe: from basic biology to clinical translation.
Incretin hormones, principally glucose-dependent insulinotropic polypeptide (GIP) and glucagon-like peptide-1(GLP-1), potentiate meal-stimulated insulin secretion through direct (GIP + GLP-1) and indirect (GLP-1) actions on islet β-cells. GIP and GLP-1 also regulate glucagon secretion, through direct and indirect pathways. The incretin hormone receptors (GIPR and GLP-1R) are widely distributed beyond the pancreas, principally in the brain, cardiovascular and immune systems, gut and kidney, consistent with a broad array of extrapancreatic incretin actions. Notably, the glucoregulatory and anorectic activities of GIP and GLP-1 have supported development of incretin-based therapies for the treatment of type 2 diabetes and obesity. Here we review evolving concepts of incretin action, focusing predominantly on GLP-1, from discovery, to clinical proof of concept, to therapeutic outcomes. We identify established vs uncertain mechanisms of action, highlighting biology conserved across species, while illuminating areas of active investigation and uncertainty that require additional clarification. Topics: Biology; Diabetes Mellitus, Type 2; Gastric Inhibitory Polypeptide; Glucagon-Like Peptide 1; Humans; Incretins | 2023 |
Glucagon-like peptide 1 receptor agonists: cardiovascular benefits and mechanisms of action.
Type 2 diabetes mellitus (T2DM) and obesity are metabolic disorders characterized by excess cardiovascular risk. Glucagon-like peptide 1 (GLP1) receptor (GLP1R) agonists reduce body weight, glycaemia, blood pressure, postprandial lipaemia and inflammation - actions that could contribute to the reduction of cardiovascular events. Cardiovascular outcome trials (CVOTs) have demonstrated that GLP1R agonists reduce the rates of major adverse cardiovascular events in patients with T2DM. Separate phase III CVOTs of GLP1R agonists are currently being conducted in people living with heart failure with preserved ejection fraction and in those with obesity. Mechanistically, GLP1R is expressed at low levels in the heart and vasculature, raising the possibility that GLP1 might have both direct and indirect actions on the cardiovascular system. In this Review, we summarize the data from CVOTs of GLP1R agonists in patients with T2DM and describe the actions of GLP1R agonists on the heart and blood vessels. We also assess the potential mechanisms that contribute to the reduction in major adverse cardiovascular events in individuals treated with GLP1R agonists and highlight the emerging cardiovascular biology of novel GLP1-based multi-agonists currently in development. Understanding how GLP1R signalling protects the heart and blood vessels will optimize the therapeutic use and development of next-generation GLP1-based therapies with improved cardiovascular safety. Topics: Cardiovascular Diseases; Cardiovascular System; Diabetes Mellitus, Type 2; Glucagon-Like Peptide 1; Glucagon-Like Peptide-1 Receptor; Humans; Hypoglycemic Agents; Obesity | 2023 |
The molecular pharmacology of glucagon agonists in diabetes and obesity.
Within recent decades glucagon receptor (GcgR) agonism has drawn attention as a therapeutic tool for the treatment of type 2 diabetes and obesity. In both mice and humans, glucagon administration enhances energy expenditure and suppresses food intake suggesting a promising metabolic utility. Therefore synthetic optimization of glucagon-based pharmacology to further resolve the physiological and cellular underpinnings mediating these effects has advanced. Chemical modifications to the glucagon sequence have allowed for greater peptide solubility, stability, circulating half-life, and understanding of the structure-function potential behind partial and "super"-agonists. The knowledge gained from such modifications has provided a basis for the development of long-acting glucagon analogues, chimeric unimolecular dual- and tri-agonists, and novel strategies for nuclear hormone targeting into glucagon receptor-expressing tissues. In this review, we summarize the developments leading toward the current advanced state of glucagon-based pharmacology, while highlighting the associated biological and therapeutic effects in the context of diabetes and obesity. Topics: Animals; Diabetes Mellitus, Type 2; Glucagon; Glucagon-Like Peptide 1; Humans; Mice; Obesity; Receptors, Glucagon | 2023 |
Pharmacogenetic interactions of medications administered for weight loss in adults: a systematic review and meta-analysis.
Topics: Adult; Bupropion; Diabetes Mellitus, Type 2; Glucagon-Like Peptide 1; Glucagon-Like Peptide-1 Receptor; Humans; Hypoglycemic Agents; Naltrexone; Peptides; Pharmacogenetics; Protein Serine-Threonine Kinases; Venoms; Weight Loss | 2023 |
A systematic review of the safety of tirzepatide-a new dual GLP1 and GIP agonist - is its safety profile acceptable?
Tirzepatide is a novel dual glucose-dependent insulinotropic peptide (GIP) and glucagon-like peptide-1 receptor agonist (GLP-1 RA). At present, there is no controversy over its effectiveness, but its safety. We conducted a systematic review to assess the safety of tirzepatide.. We searched PubMed, Embase and Cochrane databases for randomized controlled trials (RCTs) of tirzepatide from databases inception to August 28, 2022 and used the Cochrane Systematic Assessment Manual Risk of Bias Assessment Tool (version 5.1) and modified Jadad scale to assess risk of bias. The systematic review was conducted. Nine RCTs with a total of 9818 patients were included. The overall safety profile of tirzepatide is similar to GLP-1RAs, except for the hypoglycemia (tirzepatide 15mg, pooled RR=3.83, 95% CI [1.19- 12.30],. The safety profile of tirzepatide is generally acceptable, similar to GLP-1 RAs. It is necessary to pay attention to its specific adverse events (hypoglycemia and discontinuation) at high doses (10mg or higher). Nausea, vomiting, diarrhea, discontinuation and injection-site reaction were dose-dependence among specific dose ranges.As the heterogeneity in different studies by interventions, the results may be with biases and the further confirmation is needed. Meanwhile, more well-designed trials are needed to control the confounding factors and ensure adequate sample size. Topics: Diabetes Mellitus, Type 2; Diarrhea; Gastric Inhibitory Polypeptide; Glucagon-Like Peptide 1; Humans; Hypoglycemia; Hypoglycemic Agents; Nausea; Vomiting | 2023 |
Effects of neprilysin and neprilysin inhibitors on glucose homeostasis: Controversial points and a promising arena.
Neprilysin (NEP) is a transmembrane zinc-dependent metalloproteinase that inactivates various peptide hormones including glucagon-like peptide 1 (GLP-1). NEP inhibitors may be effective in the management of type 2 diabetes mellitus (T2DM) by increasing the circulating level of GLP-1. However, acute-effect NEP inhibitors may lead to detrimental effects by increasing blood glucose independent of GLP-1. These findings suggest a controversial point regarding the potential role of NEP inhibitors on glucose homeostasis in T2DM patients. Therefore, this perspective aimed to clarify the controversial points concerning the role of NEP inhibitors on glucose homeostasis in T2DM. NEP inhibitors may lead to beneficial effects by inhibition of NEP, which is involved in the impairment of glucose homeostasis through modulation of insulin resistance. NEP increases dipeptidyl peptidase-4 (DPP4) activity and contributes to increasing active GLP-1 proteolysis so NEP inhibitors may improve glycemic control through increasing endogenous GLP-1 activity and reduction of DPP4 activity. Thus, NEP inhibitors could be effective alone or in combination with antidiabetic agents in treating T2DM patients. However, long-term and short-term effects of NEP inhibitors may lead to a detrimental effect on insulin sensitivity and glucose homeostasis through different mechanisms including augmentation of substrates and pancreatic amyloid deposition. These findings are confirmed in animal but not in humans. In conclusion, NEP inhibitors produce beneficial rather than detrimental effects on glucose homeostasis and insulin sensitivity in humans though most of the detrimental effects of NEP inhibitors are confirmed in animal studies.. 脑啡肽酶(NEP)是一种跨膜锌依赖性金属蛋白酶,可使包括胰高血糖素样肽1 (GLP-1)在内的多种肽类激素失活。NEP抑制剂可能通过提高循环GLP-1水平来有效治疗2型糖尿病(T2DM)。然而,NEP抑制剂的急性效应可能会造成血糖升高,产生有害作用,且与GLP-1无关。这些发现提示NEP抑制剂对T2DM患者血糖稳态的作用尚存有争议。本视角旨在阐明NEP抑制剂对T2DM糖稳态作用的争议点。NEP通过调节胰岛素抵抗(IR)参与糖稳态受损,NEP抑制剂可能通过抑制NEP发挥有益作用。NEP增加二肽基肽酶-4 (DPP4)活性并有助于增加GLP-1蛋白水解活性,而NEP抑制剂可能通过增加内源性GLP-1活性和降低DPP4活性来改善血糖控制。因此,NEP抑制剂可单独或联合降糖药物治疗T2DM患者。然而,NEP抑制剂的长期和短期作用机制可能不同,包括增强底物和胰腺淀粉样蛋白沉积,导致对胰岛素敏感性和葡萄糖稳态的有害影响。这些发现在动物中得到证实,但在人类中未得到证实。综上所述,NEP抑制剂对人体葡萄糖稳态和胰岛素敏感性产生有益而非有害的影响,尽管大多数有害影响已在动物研究中得到证实。. Topics: Animals; Blood Glucose; Diabetes Mellitus, Type 2; Dipeptidyl Peptidase 4; Dipeptidyl-Peptidase IV Inhibitors; Glucagon-Like Peptide 1; Homeostasis; Humans; Hypoglycemic Agents; Insulin Resistance; Neprilysin | 2023 |
GLP-1 Receptor Agonists in Obese Patients with Inflammatory Bowel Disease: from Molecular Mechanisms to Clinical Considerations and Practical Recommendations for Safe and Effective Use.
To discuss current literature and provide practical recommendations for the safe and effective use of glucagon-like peptide 1 receptor agonists (GLP-1 RA) in people with inflammatory bowel disease (IBD) and type 2 diabetes (T2D) and/or obesity. The molecular mechanisms that justify the potential benefits of GLP-1 RA in IBD and the links between IBD, obesity, and cardiovascular disease are also discussed.. Preliminary data suggest that GLP-1 RA can modulate crucial pathways in the pathogenesis of IBD, such as chronic inflammation circuits, intestinal tight junctions, and gut microbiome dysbiosis, setting the stage for human trials to investigate the role of these agents in the treatment of IBD among people with or without diabetes and obesity. However, gastrointestinal side effects related to GLP-1 RA need appropriate clinical management to mitigate risks and maximize the benefits of therapy in people with IBD. GLP-1 RA originally emerged as drugs for the treatment of hyperglycemia and are currently licensed for the management of T2D and/or overweight/obesity. However, their wealth of pleiotropic actions soon raised expectations that they might confer benefits on non-metabolic disorders. Future studies are expected to clarify whether GLP-1 RA deserve an adjunct place in the arsenal of drugs against IBD. Topics: Diabetes Mellitus, Type 2; Glucagon-Like Peptide 1; Glucagon-Like Peptide-1 Receptor; Humans; Hypoglycemic Agents; Inflammatory Bowel Diseases; Obesity | 2023 |
Recent advances in the treatment of patients with obesity and chronic kidney disease.
Obesity is a chronic disease characterised by excess adiposity, which impairs health. The high prevalence of obesity raises the risk of long-term medical complications including type 2 diabetes and chronic kidney disease. Several studies have focused on patients with obesity, type 2 diabetes and chronic kidney disease due to the increased prevalence of diabetic kidney disease. Several randomized controlled trials on sodium-glucose cotransporter 2 inhibitors, glucagon-like peptide-1 analogues, and bariatric surgery in diabetic kidney disease showed renoprotective effects. However, further research is critical to address the treatment of patients with obesity and chronic kidney disease to lessen morbidity.Key messageObesity is a driver of chronic kidney disease, and type 2 diabetes, along with obesity, accelerates chronic kidney disease.Several randomized controlled trials on sodium-glucose cotransporter 2 inhibitors, glucagon-like peptide-1 analogues, and bariatric surgery in diabetic kidney disease demonstrate the improvement of renal outcomes.There is a need to address the treatment of patients with obesity and CKD to lessen morbidity. Topics: Diabetes Mellitus, Type 2; Diabetic Nephropathies; Glucagon-Like Peptide 1; Glucose; Humans; Hypoglycemic Agents; Obesity; Renal Insufficiency, Chronic; Sodium | 2023 |
Looking ahead to potential incretin combination therapies for nonalcoholic steatohepatitis in patients with diabetes.
There are no drugs approved by regulatory agencies for the treatment of nonalcoholic fatty liver disease (NAFLD); incretin combination therapies are being developed for treatment of type 2 diabetes and research has moved to test their usefulness in NAFLD.. We reviewed the literature on the effectiveness of dual and triple peptides combining receptor agonists of the glucagon-like peptide 1, the glucose-dependent insulinotropic peptide, and glucagon to treat NAFLD and its associated metabolic diseases, and/or the cardiovascular risk intimately connected with the cluster of the metabolic syndrome. Other combination peptides involved the glucagon-like peptide 2 receptor, the fibroblast growth factor 21, the cholecystokinin receptor 2, and the amylin receptor.. Both dual and triple agonists are promising, based on animal, pharmacokinetic and proof-of concept studies, showing effectiveness both in the presence and the absence of diabetes on a few validated surrogate NAFLD biomarkers, but the majority of studies are still in progress. Considering the long natural history of NAFLD, final proof of their efficacy on primary clinical liver outcomes might be also derived from the analysis of large databases of National Healthcare Systems or Insurance companies, when used in diabetes for improving glycemic control, after careful propensity-score matching. Topics: Animals; Biomarkers; Diabetes Mellitus, Type 2; Glucagon-Like Peptide 1; Humans; Incretins; Non-alcoholic Fatty Liver Disease | 2023 |
Weight loss efficiency and safety of tirzepatide: A Systematic review.
Tirzeptide is a novel glucagon-like peptide-1 receptor (GLP-1) and glucose-dependent insulinotropic polypeptide (GIP) drug, which shows good efficiency for weight loss. Therefore, we aim to investigate the efficacy and safety of tirzepatide for weight loss in type 2 diabetes mellitus (T2DM) and obesity patients in this meta-analysis study.. Cochrane Library, PubMed, Embase, Clinical Trials, and Web of Science were searched from inception to October 5, 2022. All randomized controlled trials (RCTs) were included. The odds ratio (OR) was calculated using fixed-effects or random-effects models by Review Manager 5.3 software.. In total, ten studies (12 reports) involving 9,873 patients were identified. A significant loss body weight in the tirzepatide group versus the placebo by -9.81 kg (95% CI (-12.09, -7.52), GLP-1 RAs by -1.05 kg (95% CI (-1.48, -0.63), and insulin by -1.93 kg (95% CI (-2.81, -1.05), respectively. In sub-analysis, the body weight of patients was significantly reduced in three tirzepatide doses (5 mg, 10 mg, and 15 mg) when compared with those of the placebo/GLP-1 RA/insulin. In terms of safety, the incidence of any adverse events and adverse events leading to study drug discontinuation was higher in the tirzepatide group, but the incidence of serious adverse events and hypoglycaemia was lower. Additionally, the gastrointestinal adverse events (including diarrhea, nausea, vomiting and decreased appetite) of tirzepatide were higher than those of placebo/basal insulin, but similar to GLP-1 RAs.. In conclusion, tirzeptide can significantly reduce the weight of T2DM and patient with obesity, and it is a potential therapeutic regimen for weight-loss, but we need to be vigilant about its gastrointestinal reaction. Topics: Diabetes Mellitus, Type 2; Gastric Inhibitory Polypeptide; Glucagon-Like Peptide 1; Glucagon-Like Peptide-1 Receptor; Humans; Hypoglycemic Agents; Insulin; Obesity; Weight Loss | 2023 |
[Genetic aspects of type 1 glucagon peptide agonists clinical efficacy: A review].
A review of publications devoted to the analysis of genetic polymorphisms of the gene encoding the glucagon-like peptide type 1 receptor and some other genes directly and indirectly involved in the implementation of its physiological action is presented. The aim of the study: to search for information on genes polymorphism that can affect the effectiveness of glucagon-like peptide type 1 agonists. The review was carried out in accordance with the PRISMA 2020 recommendations, the search for publications was based on PubMed databases (including Medline), Web of Science, as well as Russian scientific electronic source eLIBRARY.RU from 1993 to 2022. The several genes polymorphisms (. Представлен обзор публикаций, посвященных анализу генетических полиморфизмов гена, кодирующего рецептор глюкагоноподобного пептида 1-го типа (ГПП-1), и некоторых других генов, участвующих в реализации его физиологического действия. Цель – выявить информацию о генах, полиморфизм которых может оказывать влияние на эффективность агонистов ГПП-1. Обзор проводился в соответствии с рекомендациями PRISMA 2020, поиск публикаций осуществлялся по базам данных PubMed (включая Medline), Web of Science, а также российским научным электронным библиотекам eLIBRARY.RU с 1993 по 2022 г. Описан полиморфизм нескольких генов ( Topics: Diabetes Mellitus, Type 2; Glucagon; Glucagon-Like Peptide 1; Glucagon-Like Peptide-1 Receptor; Humans; Hypoglycemic Agents; Metabolic Syndrome; Peptides; Venoms | 2023 |
Weight loss with subcutaneous semaglutide versus other glucagon-like peptide 1 receptor agonists in type 2 diabetes: a systematic review.
Glucagon-like peptide 1 receptor agonists (GLP-1 RAs) reduce elevated blood glucose levels and induce weight loss. Multiple GLP-1 RAs and one combined GLP-1/glucose-dependent insulinotropic polypeptide agonist are currently available. This review was conducted with the aim of summarising direct comparisons between subcutaneous semaglutide and other GLP-1 RAs in individuals with type 2 diabetes (T2D), particularly with respect to efficacy for inducing weight loss and improving other markers of metabolic health. This systematic review of PubMed and Embase from inception to early 2022 was registered on PROSPERO and was conducted in accordance with the Preferred Reporting Items for Systematic Reviews and Meta-Analyses and Meta-Analysis of Observational Studies in Epidemiology guidelines. Of the 740 records identified in the search, five studies fulfilled the inclusion criteria. Comparators included liraglutide, exenatide, dulaglutide and tirzepatide. In the identified studies, multiple dosing regimens were utilised for semaglutide. Randomised trials support the superior efficacy of semaglutide over other GLP-1 RAs with respect to weight loss in T2D, but tirzepatide is more effective than semaglutide. Topics: Diabetes Mellitus, Type 2; Glucagon-Like Peptide 1; Humans; Hypoglycemic Agents; Observational Studies as Topic; Weight Loss | 2023 |
Mechanisms and clinical applications of incretin therapies for diabetes and chronic kidney disease.
Diabetic kidney disease (DKD) is the leading cause of kidney failure worldwide. Development of DKD increases risks for cardiovascular events and death. Glucagon-like peptide-1 (GLP-1) receptor agonist have demonstrated improved cardiovascular and kidney outcomes in large-scale clinical trials.. GLP-1 and dual GLP-1/glucose-depending insulinotropic polypeptide (GIP) receptor agonists have robust glucose-lowering efficacy with low risk of hypoglycemia even in advanced stages of DKD. Initially approved as antihyperglycemic therapies, these agents also reduce blood pressure and body weight. Cardiovascular outcome and glycemic lowering trials have reported decreased risks of development and progression of DKD and atherosclerotic cardiovascular events for GLP-1 receptor agonists. Kidney and cardiovascular protection is mediated partly, but not entirely, by lowering of glycemia, body weight, and blood pressure. Experimental data have identified modulation of the innate immune response as a biologically plausible mechanism underpinning kidney and cardiovascular effects.. An influx of incretin-based therapies has changed the landscape of DKD treatment. GLP-1 receptor agonist use is endorsed by all major guideline forming organizations. Ongoing clinical trials and mechanistic studies with GLP-1 and dual GLP-1/GIP receptor agonists will further define the roles and pathways for these agents in the treatment of DKD. Topics: Body Weight; Cardiovascular Diseases; Diabetes Mellitus, Type 2; Glucagon-Like Peptide 1; Glucagon-Like Peptide-1 Receptor; Glucose; Humans; Hypoglycemic Agents; Incretins; Renal Insufficiency, Chronic | 2023 |
Eosinophil-related diseases during treatment with glucagon-like peptide one receptor (GLP-1 RA): a case report and review of the literature.
Glucagon-like peptide one-receptor agonists (GLP-1 RA) are drugs that differ in their pharmacological composition and homology to human GLP-1 and are used most frequently for the treatment of type 2 diabetes and weight loss. There are isolated reports of eosinophilic adverse reactions associated with GLP-1 RA. We present the case of a 42-year-old female patient who, after starting weekly subcutaneous semaglutide, developed eosinophilic fasciitis with favorable clinical evolution after the discontinuation of semaglutide and the initiation of immunosuppression. A review of the eosinophilic adverse events that have been previously reported with GLP-1 RA is provided. Topics: Adult; Diabetes Mellitus, Type 2; Eosinophils; Female; Glucagon-Like Peptide 1; Glucagon-Like Peptide Receptors; Humans; Hypoglycemic Agents | 2023 |
Potential role of tirzepatide towards Covid-19 infection in diabetic patients: a perspective approach.
In Covid-19, variations in fasting blood glucose are considered a distinct risk element for a bad prognosis and outcome in Covid-19 patients. Tirazepatide (TZT), a dual glucagon-like peptide-1 (GLP-1)and glucose-dependent insulinotropic polypeptide (GIP) receptor agonist may be effective in managing Covid-19-induced hyperglycemia in diabetic and non-diabetic patients. The beneficial effect of TZT in T2DM and obesity is related to direct activation of GIP and GLP-1 receptors with subsequent improvement of insulin sensitivity and reduction of body weight. TZT improves endothelial dysfunction (ED) and associated inflammatory changes through modulation of glucose homeostasis, insulin sensitivity, and pro-inflammatory biomarkers release. TZT, through activation of the GLP-1 receptor, may produce beneficial effects against Covid-19 severity since GLP-1 receptor agonists (GLP-1RAs) have anti-inflammatory and pulmoprotective implications in Covid-19. Therefore, GLP-1RAs could effectively treat severely affected Covid-19 diabetic and non-diabetic patients. Notably, using GLP-1RAs in T2DM patients prevents glucose variability, a common finding in Covid-19 patients. Therefore, GLP-1RAs like TZT could be a therapeutic strategy in T2DM patients with Covid-19 to prevent glucose variability-induced complications. In Covid-19, the inflammatory signaling pathways are highly activated, resulting in hyperinflammation. GLP-1RAs reduce inflammatory biomarkers like IL-6, CRP, and ferritin in Covid-19 patients. Therefore, GLP-1RAs like TZ may be effective in Covid-19 patients by reducing the inflammatory burden. The anti-obesogenic effect of TZT may reduce Covid-19 severity by ameliorating body weight and adiposity. Furthermore, Covid-19 may induce substantial alterations in gut microbiota. GLP-1RA preserves gut microbiota and prevents intestinal dysbiosis. Herein, TZT, like other GLP-1RA, may attenuate Covid-19-induced gut microbiota alterations and, by this mechanism, may mitigate intestinal inflammation and systemic complications in Covid-19 patients with either T2DM or obesity. As opposed to that, glucose-dependent insulinotropic polypeptide (GIP) was reduced in obese and T2DM patients. However, activation of GIP-1R by TZT in T2DM patients improves glucose homeostasis. Thus, TZT, through activation of both GIP and GLP-1, may reduce obesity-mediated inflammation. In Covid-19, GIP response to the meal is impaired, leading to postprandial hyperglycemia and abnormal glucose hom Topics: Blood Glucose; Body Weight; COVID-19; Diabetes Mellitus, Type 2; Glucagon-Like Peptide 1; Glucagon-Like Peptide-1 Receptor; Glucose; Humans; Hyperglycemia; Inflammation; Insulin; Insulin Resistance; Interleukin-6; Obesity; SARS-CoV-2; Tumor Necrosis Factor-alpha | 2023 |
Gut hormone-based pharmacology: novel formulations and future possibilities for metabolic disease therapy.
Glucagon-like peptide-1 (GLP-1) receptor agonists are established pharmaceutical therapies for the treatment of type 2 diabetes and obesity. They mimic the action of GLP-1 to reduce glucose levels through stimulation of insulin secretion and inhibition of glucagon secretion. They also reduce body weight by inducing satiety through central actions. The GLP-1 receptor agonists used clinically are based on exendin-4 and native GLP-1 and are available as formulations for daily or weekly s.c. or oral administration. GLP-1 receptor agonism is also achieved by inhibitors of dipeptidyl peptidase-4 (DPP-4), which prevent the inactivation of GLP-1 and glucose-dependent insulinotropic polypeptide (GIP), thereby prolonging their raised levels after meal ingestion. Other developments in GLP-1 receptor agonism include the formation of small orally available agonists and compounds with the potential to pharmaceutically stimulate GLP-1 secretion from the gut. In addition, GLP-1/glucagon and GLP-1/GIP dual receptor agonists and GLP-1/GIP/glucagon triple receptor agonists have shown the potential to reduce blood glucose levels and body weight through their effects on islets and peripheral tissues, improving beta cell function and stimulating energy expenditure. This review summarises developments in gut hormone-based therapies and presents the future outlook for their use in type 2 diabetes and obesity. Topics: Body Weight; Diabetes Mellitus, Type 2; Glucagon; Glucagon-Like Peptide 1; Glucagon-Like Peptide-1 Receptor; Glucose; Humans; Obesity | 2023 |
Effects of GLP-1 receptor agonists on neurological complications of diabetes.
Emerging evidence suggests that treatment with glucagon-like peptide-1 receptor agonists (GLP-1 RAs) could be an interesting treatment strategy to reduce neurological complications such as stroke, cognitive impairment, and peripheral neuropathy. We performed a systematic review to examine the evidence concerning the effects of GLP-1 RAs on neurological complications of diabetes. The databases used were Pubmed, Scopus and Cochrane. We selected clinical trials which analysed the effect of GLP-1 RAs on stroke, cognitive impairment, and peripheral neuropathy. We found a total of 19 studies: 8 studies include stroke or major cardiovascular events, 7 involve cognitive impairment and 4 include peripheral neuropathy. Semaglutide subcutaneous and dulaglutide reduced stroke cases. Liraglutide, albiglutide, oral semaglutide and efpeglenatide, were not shown to reduce the number of strokes but did reduce major cardiovascular events. Exenatide, dulaglutide and liraglutide improved general cognition but no significant effect on diabetic peripheral neuropathy has been reported with GLP-1 RAs. GLP-1 RAs are promising drugs that seem to be useful in the reduction of some neurological complications of diabetes. However, more studies are needed. Topics: Cardiovascular Diseases; Diabetes Complications; Diabetes Mellitus, Type 2; Glucagon-Like Peptide 1; Glucagon-Like Peptide-1 Receptor; Humans; Hypoglycemic Agents; Liraglutide; Stroke | 2023 |
Pharmacotherapy for chronic obesity management: a look into the future.
Substantial leaps have been made in the drug discovery front in tackling the growing pandemic of obesity and its metabolic co-morbidities. Greater mechanistic insight and understanding of the gut-brain molecular pathways at play have enabled the pursuit of novel therapeutic agents that possess increasingly efficacious weight-lowering potential whilst remaining safe and tolerable for clinical use. In the wake of glucagon-like peptide 1 (GLP-1) based therapy, we look at recent advances in gut hormone biology that have fermented the development of next generation pharmacotherapy in diabesity that harness synergistic potential. In this paper, we review the latest data from the SURPASS and SURMOUNT clinical trials for the novel 'twincretin', known as Tirzepatide, which has demonstrated sizeable body weight reduction as well as glycaemic efficacy. We also provide an overview of amylin-based combination strategies and other emerging therapies in the pipeline that are similarly providing great promise for the future of chronic management of obesity. Topics: Diabetes Mellitus, Type 2; Glucagon-Like Peptide 1; Humans; Hypoglycemic Agents; Obesity | 2023 |
Glucagon-like peptide-1: a multi-faceted anti-inflammatory agent.
Inflammation contributes to many chronic conditions. It is often associated with circulating pro-inflammatory cytokines and immune cells. GLP-1 levels correlate with disease severity. They are often elevated and can serve as markers of inflammation. Previous studies have shown that oxytocin, hCG, ghrelin, alpha-MSH and ACTH have receptor-mediated anti-inflammatory properties that can rescue cells from damage and death. These peptides have been studied well in the past century. In contrast, GLP-1 and its anti-inflammatory properties have been recognized only recently. GLP-1 has been proven to be a useful adjuvant therapy in type-2 diabetes mellitus, metabolic syndrome, and hyperglycemia. It also lowers HbA1C and protects cells of the cardiovascular and nervous systems by reducing inflammation and apoptosis. In this review we have explored the link between GLP-1, inflammation, and sepsis. Topics: Anti-Inflammatory Agents; Diabetes Mellitus, Type 2; Glucagon-Like Peptide 1; Humans; Inflammation; Peptides | 2023 |
DPP-4 inhibitors and type 2 diabetes mellitus in Parkinson's disease: a mutual relationship.
Parkinson's disease (PD) usually occurs due to the degeneration of dopaminergic neurons in the substantia nigra (SN). Management of PD is restricted to symptomatic improvement. Consequently, a novel treatment for managing motor and non-motor symptoms in PD is necessary. Abundant findings support the protection of dipeptidyl peptidase 4 (DPP-4) inhibitors in PD. Consequently, this study aims to reveal the mechanism of DPP-4 inhibitors in managing PD. DPP-4 inhibitors are oral anti-diabetic agents approved for managing type 2 diabetes mellitus (T2DM). T2DM is linked with an increased chance of the occurrence of PD. Extended usage of DPP-4 inhibitors in T2DM patients may attenuate the development of PD by inhibiting inflammatory and apoptotic pathways. Thus, DPP-4 inhibitors like sitagliptin could be a promising treatment against PD neuropathology via anti-inflammatory, antioxidant, and anti-apoptotic impacts. DPP-4 inhibitors, by increasing endogenous GLP-1, can also reduce memory impairment in PD. In conclusion, the direct effects of DPP-4 inhibitors or indirect effects through increasing circulating GLP-1 levels could be an effective therapeutic strategy in treating PD patients through modulation of neuroinflammation, oxidative stress, mitochondrial dysfunction, and neurogenesis. Topics: Diabetes Mellitus, Type 2; Dipeptidyl-Peptidase IV Inhibitors; Glucagon-Like Peptide 1; Humans; Hypoglycemic Agents; Parkinson Disease; Sitagliptin Phosphate | 2023 |
Perspectives on weight control in diabetes - Tirzepatide.
Tirzepatide, a once-weekly glucose-dependent insulinotropic polypeptide (GIP)/glucagon-like peptide-1 (GLP-1) receptor agonist (GIP/GLP-1 RA) improves glycemic control. Besides improvement of glycemic control, tirzepatide treatment is associated with significantly more weight loss as compared to potent selective GLP-1 receptor agonists as well as other beneficial changes in cardio-metabolic parameters, such as reduced fat mass, blood pressure, improved insulin sensitivity, lipoprotein concentrations, and circulating metabolic profile in individuals with type 2 diabetes (T2D). Some of these changes are partially associated with weight reduction. We review here the putative mechanisms of GIP receptor agonism contributing to GLP-1 receptor agonism-induced weight loss and respective findings with GIP/GLP-1 RAs, including tirzepatide in T2D preclinical models and clinical studies. Subsequently, we summarize the clinical data on weight loss and related non-glycemic metabolic changes of tirzepatide in T2D. These findings suggest that the robust weight loss and associated changes are important contributors to the clinical profile of tirzepatide for the treatment of T2D diabetes and serve as the basis for further investigations including clinical outcomes. Topics: Diabetes Mellitus, Type 2; Gastric Inhibitory Polypeptide; Glucagon-Like Peptide 1; Glucagon-Like Peptide-1 Receptor; Humans; Hypoglycemic Agents; Weight Loss | 2023 |
Therapeutic Mechanisms and Clinical Effects of Glucagon-like Peptide 1 Receptor Agonists in Nonalcoholic Fatty Liver Disease.
Nonalcoholic fatty liver disease (NAFLD) can lead to liver fibrosis and cirrhosis. Recently, glucagon-like peptide 1 receptor agonists (GLP-1RAs), a class of drugs used to treat type 2 diabetes and obesity, have shown therapeutic effects against NAFLD. In addition to reducing blood glucose levels and body weight, GLP-1RAs are effective in improving the clinical, biochemical, and histological markers of hepatic steatosis, inflammation, and fibrosis in patients with NAFLD. Additionally, GLP-1RAs have a good safety profile with minor side effects, such as nausea and vomiting. Overall, GLP-1RAs show promise as a potential treatment for NAFLD, and further studies are required to determine their long-term safety and efficacy. Topics: Diabetes Mellitus, Type 2; Glucagon-Like Peptide 1; Glucagon-Like Peptide-1 Receptor; Humans; Hypoglycemic Agents; Liver Cirrhosis; Non-alcoholic Fatty Liver Disease | 2023 |
Comparison on cognitive outcomes of antidiabetic agents for type 2 diabetes: A systematic review and network meta-analysis.
We aimed to summarise current evidence on different antidiabetic drugs to delay cognitive impairment, including mild cognitive impairment, dementia, Alzheimer's disease (AD) and vascular dementia, among subjects with type 2 diabetes mellitus (T2DM). Medline, Cochrane and Embase databases were searched from inception to 31 July 2022. Two investigators independently reviewed and screened trials comparing antidiabetic drugs with no antidiabetic drugs, placebo, or other active antidiabetic drugs on cognitive outcomes in T2DM. Data were analysed using meta-analysis and network meta-analysis. Twenty-seven studies met the inclusion criteria, including 3 randomised controlled trials, 19 cohort studies and 5 case-control studies. Compared with non-user, SGLT-2i (OR 0.41 [95% CI 0.22-0.76]), GLP-1RA (OR 0.34 [95% CI 0.14-0.85]), thiazolidinedione (OR 0.60 [95% CI 0.51-0.69]), and DPP-4i (OR 0.78 [95% CI 0.61-0.99]) users had a decreased risk of dementia, whereas sulfonylurea (OR 1.43 [95% CI 1.11-1.82]) increased dementia risk. Network meta-analysis showed that SGLT-2i was most likely to rank best (SUCRA = 94.4%), GLP-1 RA second best (SUCRA = 92.7%), thiazolidinedione third best (SUCRA = 74.7%) and DPP-4i fourth best (SUCRA = 54.9%), while sulfonylurea second worst (SUCRA = 20.0%) for decreasing dementia outcomes, by synthesising evidence from direct and indirect comparisons of multiple intervention. Evidence suggests the effects of SGLT-2i ≈ GLP-1 RAs > thiazolidinedione > DPP-4i for delaying cognitive impairment, dementia and AD outcomes, whereas sulfonylurea was associated with the highest risk. These findings provide evidence for evaluating the optional treatment for clinical practice. PROSPERO REGISTRATION: Registration no. CRD42022347280. Topics: Cognition; Dementia; Diabetes Mellitus, Type 2; Dipeptidyl-Peptidase IV Inhibitors; Glucagon-Like Peptide 1; Glucagon-Like Peptide-1 Receptor; Humans; Hypoglycemic Agents; Network Meta-Analysis; Sulfonylurea Compounds; Thiazolidinediones | 2023 |
Gut hormone co-agonists for the treatment of obesity: from bench to bedside.
The discovery and development of so-called gut hormone co-agonists as a new class of drugs for the treatment of diabetes and obesity is considered a transformative breakthrough in the field. Combining action profiles of multiple gastrointestinal hormones within a single molecule, these novel therapeutics achieve synergistic metabolic benefits. The first such compound, reported in 2009, was based on balanced co-agonism at glucagon and glucagon-like peptide-1 (GLP-1) receptors. Today, several classes of gut hormone co-agonists are in development and advancing through clinical trials, including dual GLP-1-glucose-dependent insulinotropic polypeptide (GIP) co-agonists (first described in 2013), and triple GIP-GLP-1-glucagon co-agonists (initially designed in 2015). The GLP-1-GIP co-agonist tirzepatide was approved in 2022 by the US Food and Drug Administration for the treatment of type 2 diabetes, providing superior HbA1c reductions compared to basal insulin or selective GLP-1 receptor agonists. Tirzepatide also achieved unprecedented weight loss of up to 22.5%-similar to results achieved with some types of bariatric surgery-in non-diabetic individuals with obesity. In this Perspective, we summarize the discovery, development, mechanisms of action and clinical efficacy of the different types of gut hormone co-agonists, and discuss potential challenges, limitations and future developments. Topics: Diabetes Mellitus, Type 2; Gastrointestinal Hormones; Glucagon; Glucagon-Like Peptide 1; Humans; Obesity; United States | 2023 |
Current findings on the efficacy of incretin-based drugs for diabetic kidney disease: A narrative review.
Diabetic kidney disease (DKD) is the most common cause of chronic kidney disease (CKD), leading end-stage renal disease. Thus, DKD is one of the most important diabetic complications. Incretin-based therapeutic agents, such as glucagon-like peptide-1 (GLP-1) receptor agonizts and dipeptidyl peptidase-4 (DPP-4) inhibitors have been reported to elicit vasotropic actions, suggesting a potential for effecting reduction in DKD. Glucose-dependent insulinotropic polypeptide (GIP) is also classified as an incretin. However, the insulin action after GIP secretion is known to be drastically reduced in patients with type 2 diabetes. Therefore, GIP has been formally considered unsuitable as a treatment for type 2 diabetes in the past. This concept is changing as it has been reported that resistance to GIP can be reversed and its effect restored with improved glycemic control. The development of novel dual- or triple- receptor agonizts that can bind to the receptors, not only for GLP-1 but also to GIP and glucagon receptors, is intended to simultaneously address several metabolic pathways including protein, lipid, and carbohydrate metabolism. These led to the development of GIP receptor agonist-based drugs for type 2 diabetes. The possibility of combined GIP/GLP-1 receptor agonist was also explored. The novel dual GIP and GLP-1 receptor agonist tirzepatide has recently been launched (Mounjaro®, Lilly). We have revealed precise mechanisms of the renoprotective effect of GLP-1 receptor agonizts or DPP-4 inhibitors, while the long-term effect of tirzepatide will need to be determined and its potential effects on kidneys should be properly tested. Topics: Blood Glucose; Diabetes Mellitus, Type 2; Diabetic Nephropathies; Dipeptidyl-Peptidase IV Inhibitors; Gastric Inhibitory Polypeptide; Glucagon-Like Peptide 1; Glucagon-Like Peptide-1 Receptor; Humans; Hypoglycemic Agents; Incretins | 2023 |
Glucagon-like peptide 1 (GLP-1) receptor agonists as a protective factor for incident depression in patients with diabetes mellitus: A systematic review.
Glucagon-like peptide 1 (GLP-1) receptor agonists are widely used for glycemic control in patients with diabetes mellitus (DM) and are primarily indicated for type 2 diabetes mellitus (T2DM). GLP-1 receptor agonists have also been shown to have neuroprotective and antidepressant properties. Replicated evidence suggests that individuals with DM are significantly more likely to develop depression. Herein, we aim to investigate whether GLP-1 receptor agonists can be used prophylactically on patients with DM to lower the risk of incident depression. We conducted a systematic search for English-language articles published on the PubMed/MEDLINE, Scopus, Embase, APA, PsycInfo, Ovid and Google Scholar databases from inception to June 6, 2022. Four retrospective observational studies were identified that evaluated the neuroprotective effects of GLP-1 receptor agonists on incident depression in patients with DM. We found mixed results with regards to lowering the risk of incident depression, with two studies demonstrating a significant reduction in risk and two studies showing no such effect. A single study found that dulaglutide may lower susceptibility to depression. Our results were limited by high interstudy heterogeneity, paucity of literature, and lack of controlled trials. While we did not find evidence of GLP-1 receptor agonists significantly lowering risk of incident depression in patients with DM, promising neuroprotective data presented in two of the included papers, specifically on dulaglutide where information is scarce, provide the impetus for further investigation. Future research should focus on better elucidating the neuroprotective potential of different classes and doses of GLP-1 receptor agonists using controlled trials. Topics: Depression; Diabetes Mellitus, Type 2; Glucagon-Like Peptide 1; Glucagon-Like Peptide-1 Receptor; Humans; Hypoglycemic Agents; Protective Factors; Retrospective Studies | 2023 |
Effect of incretins on skeletal health.
The incretin hormones, glucagon like peptide-1 (GLP-1) and gastric inhibitory peptide (GIP), have been shown to decrease bone resorption in humans. The aim of this review is to collate evidence and current advances in the research within the last year on the effect of incretins on skeletal health.. Preclinical studies show potential direct beneficial effects on bone by GLP-1 and GIP, however real world epidemiological data show no effects of GLP-1 receptor analogues on fracture risk. This may be due to the weight loss accompanied by GLP-1 treatment which may have detrimental effects on bone. GIP is shown to reduce bone resorption and increase bone formation. Further evidence suggests an additive effect of GIP and glucagon like peptide-2, which could affect bone by different mechanisms.. GIP and GLP-1 based therapies are more widespread used and may have potential beneficial effects on bone, possibly counterbalanced by weight loss. Long-term effects and side-effects of GIP or GIP/ GLP-2 co-administration remain to be elucidated, and longer term treatment trials are needed. Topics: Bone Resorption; Diabetes Mellitus, Type 2; Gastric Inhibitory Polypeptide; Glucagon-Like Peptide 1; Glucagon-Like Peptide-1 Receptor; Humans; Incretins; Weight Loss | 2023 |
Novel Antidiabetic Agents and Their Effects on Lipid Profile: A Single Shot for Several Cardiovascular Targets.
Type-2 diabetes mellitus (DM) represents one of the most important risk factors for cardiovascular diseases (CVD). Hyperglycemia and glycemic variability are not the only determinant of the increased cardiovascular (CV) risk in diabetic patients, as a frequent metabolic disorder associated with DM is dyslipidemia, characterized by hypertriglyceridemia, decreased high-density lipoprotein (HDL) cholesterol levels and a shift towards small dense low-density lipoprotein (LDL) cholesterol. This pathological alteration, also called diabetic dyslipidemia, represents a relevant factor which could promotes atherosclerosis and subsequently an increased CV morbidity and mortality. Recently, the introduction of novel antidiabetic agents, such as sodium glucose transporter-2 inhibitors (SGLT2i), dipeptidyl peptidase-4 inhibitors (DPP4i) and glucagon-like peptide-1 (GLP-1) receptor agonists (GLP-1 RAs), has been associated with a significant improvement in CV outcomes. Beyond their known action on glycemia, their positive effects on the CV system also seems to be related to an ameliorated lipidic profile. In this context, this narrative review summarizes the current knowledge regarding these novel anti-diabetic drugs and their effects on diabetic dyslipidemia, which could explain the provided global benefit to the cardiovascular system. Topics: Cardiovascular Diseases; Cardiovascular System; Diabetes Mellitus, Type 2; Dipeptidyl-Peptidase IV Inhibitors; Dyslipidemias; Glucagon-Like Peptide 1; Glucagon-Like Peptide-1 Receptor; Humans; Hypoglycemic Agents; Lipids | 2023 |
Incretin hormones and type 2 diabetes.
Incretin hormones (glucose-dependent insulinotropic polypeptide [GIP] and glucagon-like peptide-1 [GLP-1]) play a role in the pathophysiology of type 2 diabetes. Along with their derivatives they have shown therapeutic success in type 2 diabetes, with the potential for further improvements in glycaemic, cardiorenal and body weight-related outcomes. In type 2 diabetes, the incretin effect (greater insulin secretory response after oral glucose than with 'isoglycaemic' i.v. glucose, i.e. with an identical glycaemic stimulus) is markedly reduced or absent. This appears to be because of a reduced ability of GIP to stimulate insulin secretion, related either to an overall impairment of beta cell function or to specific defects in the GIP signalling pathway. It is likely that a reduced incretin effect impacts on postprandial glycaemic excursions and, thus, may play a role in the deterioration of glycaemic control. In contrast, the insulinotropic potency of GLP-1 appears to be much less impaired, such that exogenous GLP-1 can stimulate insulin secretion, suppress glucagon secretion and reduce plasma glucose concentrations in the fasting and postprandial states. This has led to the development of incretin-based glucose-lowering medications (selective GLP-1 receptor agonists or, more recently, co-agonists, e.g. that stimulate GIP and GLP-1 receptors). Tirzepatide (a GIP/GLP-1 receptor co-agonist), for example, reduces HbA Topics: Blood Glucose; Body Weight; Diabetes Mellitus, Type 2; Gastric Inhibitory Polypeptide; Glucagon-Like Peptide 1; Glucagon-Like Peptide-1 Receptor; Glucose; Humans; Incretins; Insulin; Weight Loss | 2023 |
Socioeconomic aspects of incretin-based therapy.
Incretin-based therapies, particularly glucagon-like peptide-1 receptor agonists (GLP-1 RAs), have demonstrated cardiovascular benefits in people with type 2 diabetes. However, socioeconomic disparities in their uptake may constrain the collective advantages offered by these medications to the broader population. In this review we examine the socioeconomic disparities in the utilisation of incretin-based therapies and discuss strategies to address these inequalities. Based on real-world evidence, the uptake of GLP-1 RAs is reduced in people who live in socioeconomically disadvantaged areas, have low income and education level, or belong to racial/ethnic minorities, even though these individuals have a greater burden of type 2 diabetes and cardiovascular disease. Contributing factors include suboptimal health insurance coverage, limited accessibility to incretin-based therapies, financial constraints, low health literacy and physician-patient barriers such as provider bias. Advocating for a reduction in the price of GLP-1 RAs is a pivotal initial step to enhance their affordability among lower socioeconomic groups and improve their value-for-money from a societal perspective. By implementing cost-effective strategies, healthcare systems can amplify the societal benefits of incretin-based therapies, alongside measures that include maximising treatment benefits in specific subpopulations while minimising harms in vulnerable individuals, increasing accessibility, enhancing health literacy and overcoming physician-patient barriers. A collaborative approach between governments, pharmaceutical companies, healthcare providers and people with diabetes is necessary for the effective implementation of these strategies to enhance the overall societal benefits of incretin-based therapies. Topics: Diabetes Mellitus, Type 2; Dipeptidyl-Peptidase IV Inhibitors; Glucagon-Like Peptide 1; Glucagon-Like Peptide-1 Receptor; Humans; Hypoglycemic Agents; Incretins; Socioeconomic Factors | 2023 |
Interventions for people with type 2 diabetes mellitus fasting during Ramadan.
Fasting during Ramadan is obligatory for adult Muslims, except those who have a medical illness. Many Muslims with type 2 diabetes (T2DM) choose to fast, which may increase their risks of hypoglycaemia and dehydration.. To assess the effects of interventions for people with type 2 diabetes fasting during Ramadan.. We searched CENTRAL, MEDLINE, PsycINFO, CINAHL, WHO ICTRP and ClinicalTrials.gov (29 June 2022) without language restrictions.. Randomised controlled trials (RCTs) conducted during Ramadan that evaluated all pharmacological or behavioural interventions in Muslims with T2DM.. Two authors screened and selected records, assessed risk of bias and extracted data independently. Discrepancies were resolved by a third author. For meta-analyses we used a random-effects model, with risk ratios (RRs) for dichotomous outcomes and mean differences (MDs) for continuous outcomes with their associated 95% confidence intervals (CIs). We assessed the certainty of evidence using the GRADE approach.. We included 17 RCTs with 5359 participants, with a four-week study duration and at least four weeks of follow-up. All studies had at least one high-risk domain in the risk of bias assessment. Four trials compared dipeptidyl-peptidase-4 (DPP-4) inhibitors with sulphonylurea. DPP-4 inhibitors may reduce hypoglycaemia compared to sulphonylureas (85/1237 versus 165/1258, RR 0.53, 95% CI 0.41 to 0.68; low-certainty evidence). Serious hypoglycaemia was similar between groups (no events were reported in two trials; 6/279 in the DPP-4 versus 4/278 in the sulphonylurea group was reported in one trial, RR 1.49, 95% CI 0.43 to 5.24; very low-certainty evidence). The evidence was very uncertain about the effects of DPP-4 inhibitors on adverse events other than hypoglycaemia (141/1207 versus 157/1219, RR 0.90, 95% CI 0.52 to 1.54) and HbA1c changes (MD -0.11%, 95% CI -0.57 to 0.36) (very low-certainty evidence for both outcomes). No deaths were reported (moderate-certainty evidence). Health-related quality of life (HRQoL) and treatment satisfaction were not evaluated. Two trials compared meglitinides with sulphonylurea. The evidence is very uncertain about the effect on hypoglycaemia (14/133 versus 21/140, RR 0.72, 95% CI 0.40 to 1.28) and HbA1c changes (MD 0.38%, 95% CI 0.35% to 0.41%) (very low-certainty evidence for both outcomes). Death, serious hypoglycaemic events, adverse events, treatment satisfaction and HRQoL were not evaluated. One trial compared sodium-glucose co-transporter-2 (SGLT-2) inhibitors with sulphonylurea. SGLT-2 may reduce hypoglycaemia compared to sulphonylurea (4/58 versus 13/52, RR 0.28, 95% CI 0.10 to 0.79; low-certainty evidence). The evidence was very uncertain for serious hypoglycaemia (one event reported in both groups, RR 0.90, 95% CI 0.06 to 13.97) and adverse events other than hypoglycaemia (20/58 versus 18/52, RR 1.00, 95% CI 0.60 to 1.67) (very low-certainty evidence for both outcomes). SGLT-2 inhibitors result in little or no difference in HbA1c (MD 0.27%, 95% CI -0.04 to 0.58; 1 trial, 110 participants; low-certainty evidence). Death, treatment satisfaction and HRQoL were not evaluated. Three trials compared glucagon-like peptide 1 (GLP-1) analogues with sulphonylurea. GLP-1 analogues may reduce hypoglycaemia compared to sulphonylurea (20/291 versus 48/305, RR 0.45, 95% CI 0.28 to 0.74; low-certainty evidence). The evidence was very uncertain for serious hypoglycaemia (0/91 versus 1/91, RR 0.33, 95% CI 0.01 to 7.99; very low-certa. There is no clear evidence of the benefits or harms of interventions for individuals with T2DM who fast during Ramadan. All results should be interpreted with caution due to concerns about risk of bias, imprecision and inconsistency between studies, which give rise to low- to very low-certainty evidence. Major outcomes, such as mortality, health-related quality of life and severe hypoglycaemia, were rarely evaluated. Sufficiently powered studies that examine the effects of various interventions on these outcomes are needed. Topics: Adult; Diabetes Mellitus, Type 2; Dipeptidyl-Peptidase IV Inhibitors; Fasting; Glucagon-Like Peptide 1; Glycated Hemoglobin; Humans; Hypoglycemia; Insulin | 2023 |
Blood pressure-lowering effects of SGLT2 inhibitors and GLP-1 receptor agonists for preventing of cardiovascular events and death in type 2 diabetes: a systematic review and meta-analysis.
To investigate the lowering BP effects of sodium glucose cotransporter 2 inhibitors (SGLT2i) and glucagon-like peptide 1 receptor agonists (GLP-1 RAs) on the risk of major cardiovascular event stratified by glucose-lowering drugs, baseline BP, glycated hemoglobin (HbA. We performed a systematic review of the MEDLINE and EMBASE databases search up to December 31, 2022, (PROSPERO, CRD42023400899) to identify all large-scale cardiovascular outcomes (CVO) trials of SGLT2i and GLP-1 RAs in which more than 1,000 patient-years of follow-up in each randomized group. Outcomes included all-cause mortality, major adverse cardiovascular event (MACE) and its component (cardiovascular death, myocardial infarction [MI], and stroke), heart failure, and renal failure. A random-effects meta-analyses were used to pool the estimates.. Eighteen CVOTs (ten for SGLT2i and eight for GLP-1 RAs) with 127,606 patients with type 2 diabetes were included. Over 2.5 years median follow-up, the average reduction of systolic BP was 2.2 mmHg (mean difference [MD] - 2.2; 95% CI - 2.7 to - 1.7) with more important reduction (P. In patients with type 2 diabetes, the hypotensive effects of SGLT2i and GLP-1 RAs were significantly associated with a reduction in mortality and cardiorenal events. These findings suggest that the lowering BP effect could be seen as an additive indicator of cardiovascular protection by SGLT2i and GLP-1 RAs drugs. Topics: Blood Pressure; Cardiovascular Diseases; Diabetes Mellitus, Type 2; Glucagon-Like Peptide 1; Glucagon-Like Peptide-1 Receptor; Heart Failure; Humans; Hypoglycemic Agents; Myocardial Infarction; Renal Insufficiency; Sodium-Glucose Transporter 2 Inhibitors; Stroke | 2023 |
Postprandial plasma GLP-1 levels are elevated in individuals with postprandial hypoglycaemia following Roux-en-Y gastric bypass - a systematic review.
Bariatric surgery is the most effective treatment in individuals with obesity to achieve remission of type 2 diabetes. Post-bariatric surgery hypoglycaemia occurs frequently, and management remains suboptimal, because of a poor understanding of the underlying pathophysiology. The glucoregulatory hormone responses to nutrients in individuals with and without post-bariatric surgery hypoglycaemia have not been systematically examined.. The study protocol was prospectively registered with PROSPERO. PubMed, EMBASE, Web of Science and the Cochrane databases were searched for publications between January 1990 and November 2021 using MeSH terms related to post-bariatric surgery hypoglycaemia. Studies were included if they evaluated individuals with post-bariatric surgery hypoglycaemia and included measurements of plasma glucagon-like peptide-1 (GLP-1), glucose-dependent insulinotropic polypeptide (GIP), insulin, C-peptide and/or glucagon concentrations following an ingested nutrient load. Glycated haemoglobin (HbA. From 377 identified publications, 12 were included in the analysis. In all 12 studies, the type of bariatric surgery was Roux-en-Y gastric bypass (RYGB). Comparing individuals with and without post-bariatric surgery hypoglycaemia following an ingested nutrient load, the standardised mean difference in peak GLP-1 was 0.57 (95% CI, 0.32, 0.82), peak GIP 0.05 (-0.26, 0.36), peak insulin 0.84 (0.44, 1.23), peak C-peptide 0.69 (0.28, 1.1) and peak glucagon 0.05 (-0.26, 0.36). HbA. Following RYGB, postprandial peak plasma GLP-1, insulin and C-peptide concentrations are greater in individuals with post-bariatric surgery hypoglycaemia, while HbA Topics: Blood Glucose; C-Peptide; Diabetes Mellitus, Type 2; Gastric Bypass; Gastric Inhibitory Polypeptide; Glucagon; Glucagon-Like Peptide 1; Humans; Hypoglycemia; Insulin | 2023 |
New anti-diabetic agents for the treatment of non-alcoholic fatty liver disease: a systematic review and network meta-analysis of randomized controlled trials.
This network meta-analysis aims to compare the efficacy and safety of new anti-diabetic medications for the treatment of non-alcoholic fatty liver disease (NAFLD).. PubMed and Scopus were searched from inception to 27. 2,252 patients from 31 RCTs were included. "Add-on" GLP-1 agonists with standard of care (SoC) treatment showed significantly reduced IHS compared to SoC alone [USMD (95%CI) -3.93% (-6.54%, -1.33%)]. Surface under the cumulative ranking curve (SUCRA) identified GLP-1 receptor agonists with the highest probability to reduce IHS (SUCRA 88.5%), followed by DPP-4 inhibitors (SUCRA 69.6%) and pioglitazone (SUCRA 62.2%). "Add-on" GLP-1 receptor agonists were also the most effective treatment for reducing liver enzyme levels; AST [USMD of -5.04 (-8.46, -1.62)], ALT [USMD of -9.84 (-16.84, -2.85)] and GGT [USMD of -15.53 (-22.09, -8.97)] compared to SoC alone. However, GLP-1 agonists were most likely to be associated with an adverse event compared to other interventions.. GLP-1 agonists may represent the most promising anti-diabetic treatment to reduce hepatic steatosis and liver enzyme activity in T2DM and NAFLD patients. Nevertheless, longer-term studies are required to determine whether this delays progression of liver cirrhosis in patients with NAFLD and T2DM.. https://www.crd.york.ac.uk/prospero/, identifier CRD42021259336.1. Topics: Diabetes Mellitus, Type 2; Dipeptidyl-Peptidase IV Inhibitors; Glucagon-Like Peptide 1; Glucagon-Like Peptide-1 Receptor; Humans; Hypoglycemic Agents; Network Meta-Analysis; Non-alcoholic Fatty Liver Disease; Randomized Controlled Trials as Topic | 2023 |
Emerging Role of GLP-1 Agonists in Obesity: A Comprehensive Review of Randomised Controlled Trials.
Obesity is a chronic disease with high prevalence and associated comorbidities, making it a growing global concern. These comorbidities include type 2 diabetes, hypertension, ventilatory dysfunction, arthrosis, venous and lymphatic circulation diseases, depression, and others, which have a negative impact on health and increase morbidity and mortality. GLP-1 agonists, used to treat type 2 diabetes, have been shown to be effective in promoting weight loss in preclinical and clinical studies. This review summarizes numerous studies conducted on the main drugs in the GLP-1 agonists class, outlining the maximum achievable weight loss. Our aim is to emphasize the active role and main outcomes of GLP-1 agonists in promoting weight loss, as well as in improving hyperglycemia, insulin sensitivity, blood pressure, cardio-metabolic, and renal protection. We highlight the pleiotropic effects of these medications, along with their indications, contraindications, and precautions for both diabetic and non-diabetic patients, based on long-term follow-up studies. Topics: Diabetes Mellitus, Type 2; Exenatide; Glucagon-Like Peptide 1; Glucagon-Like Peptide-1 Receptor; Humans; Hypoglycemic Agents; Liraglutide; Obesity; Peptides; Randomized Controlled Trials as Topic; Weight Loss | 2023 |
Endogenous glucagon-like peptide (GLP)-1 as alternative for GLP-1 receptor agonists: Could this work and how?
In recent years, we have witnessed the many beneficial effects of glucagon-like peptide (GLP)-1 receptor agonists, including the reduction in cardiovascular risk in patients with type 2 diabetes, and the reduction of body weight in those with obesity. Increasing evidence suggests that these agents differ considerably from endogenous GLP-1 when it comes to their routes of action, although their clinical effects appear to be the same. Given the limitations of the GLP-1 receptor agonists, could it be useful to develop agents which stimulate GLP-1 release? Here we will discuss the differences and similarities between GLP-1 receptor agonists and endogenous GLP-1, and will detail how endogenous GLP-1-when stimulated appropriately-could have clinically relevant effects. Topics: Diabetes Mellitus, Type 2; Glucagon-Like Peptide 1; Glucagon-Like Peptide-1 Receptor; Humans; Hypoglycemic Agents; Obesity | 2023 |
The future of incretins in the treatment of obesity and non-alcoholic fatty liver disease.
In the last few decades, glucagon-like peptide-1 receptor (GLP-1R) agonists have changed current guidelines and improved outcomes for individuals with type 2 diabetes. However, the dual glucose-dependent insulinotropic polypeptide receptor (GIPR)/GLP-1R agonist, tirzepatide, has demonstrated superior efficacy regarding improvements in HbA Topics: Diabetes Mellitus, Type 2; Gastric Inhibitory Polypeptide; Glucagon-Like Peptide 1; Glucagon-Like Peptide-1 Receptor; Humans; Incretins; Non-alcoholic Fatty Liver Disease; Obesity | 2023 |
Do oral antidiabetic medications alter the risk of Parkinson's disease? An updated systematic review and meta-analysis.
Diabetes mellitus is a known risk factor for Parkinson's disease (PD), but does this risk vary with antidiabetic medications is still unclear. This meta-analysis aims to compile evidence from the literature to assess the risk of idiopathic PD with various oral antidiabetic medications.. Databases PubMed, CENTRAL, Scopus, Web of Science, and Embase were searched till 5th April 2023. Adjusted outcomes were pooled to generate a hazard ratio (HR) on the risk of PD with different antidiabetic medications.. Fifteen studies with 2,910,405 diabetic patients were eligible. Pooled analysis failed to show any significant difference in the risk of PD among users of metformin (HR: 1.05 95% CI: 0.91, 1.22 I. Limited retrospective evidence indicates that DPP4i may reduce the risk of idiopathic PD in diabetics. Metformin, sulfonylureas, glucagon-like peptide-1 agonists, and glitazones were not associated with any change in the risk of PD. Further studies taking into confounding factors and using a common comparator group are needed to strengthen present evidence. Topics: Diabetes Mellitus, Type 2; Glucagon-Like Peptide 1; Humans; Hypoglycemic Agents; Metformin; Parkinson Disease; Retrospective Studies; Sulfonylurea Compounds; Thiazolidinediones | 2023 |
Future therapies for obesity.
Obesity is a chronic disease associated with increased morbidity and mortality. Bariatric surgery can lead to sustained long-term weight loss (WL) and improvement in multiple obesity-related complications, but it is not scalable at the population level. Over the past few years, gut hormone-based pharmacotherapies for obesity and type 2 diabetes mellitus (T2DM) have rapidly evolved, and combinations of glucagon-like peptide 1 (GLP1) with other gut hormones (glucose-dependent insulinotropic polypeptide (GIP), glucagon, and amylin) as dual or triple agonists are under investigation to enhance and complement the effects of GLP1 on WL and obesity-related complications. Tirzepatide, a dual agonist of GLP1 and GIP receptors, marks a new era in obesity pharmacotherapy in which a combination of gut hormones could approach the WL achieved with bariatric surgery. In this review, we discuss emerging obesity treatments with a focus on gut hormone combinations and the concept of a multimodal approach for obesity management. Topics: Bariatric Surgery; Diabetes Mellitus, Type 2; Gastrointestinal Hormones; Glucagon-Like Peptide 1; Humans; Obesity; Weight Loss | 2023 |
Beyond glycemia: Comparing tirzepatide to GLP-1 analogues.
Glucagon-like peptide-1 receptor analogs (GLP-1 RAs) have been an innovative and instrumental drug class in the management of both type 2 diabetes and obesity. Tirzepatide is a novel agent that acts as an agonist for both GLP-1 receptors and gastric inhibitory polypeptide (GIP) receptors, another incretin that lowers glucose and appetite. Although previous studies showed a lack of therapeutic benefit for GIP agonists, current studies show that the glucose lowering and weight loss effects of tirzepatide are at least as effective as GLP-1 RAs with a similar adverse effect profile. Some studies, though not conclusive, predict that tirzepatide may in fact be more potent than GLP-1 RAs at reducing weight. A thorough review of the studies that led to tirzepatide's approval allows for comparisons between tirzepatide and GLP-1 RAs; it also allows for predictions of tirzepatide's eventual place in therapy - an agent used preferentially over GLP-1 RAs in patients with or without diabetes desiring to lose weight. Topics: Diabetes Mellitus, Type 2; Gastric Inhibitory Polypeptide; Glucagon-Like Peptide 1; Glucagon-Like Peptide-1 Receptor; Glucose; Humans; Hypoglycemic Agents | 2023 |
Cardiovascular prevention with glucose-lowering drugs in type 2 diabetes: An evidence-based approach to the categories of primary and secondary prevention.
Whether to recommend specifically the glucose-lowering therapies with cardiovascular benefit only in secondary prevention, or also in patients with multiple risk factors (MRF) but without established atherosclerotic cardiovascular disease (ASCVD), is controversial across the guidelines for diabetes.. We performed a meta-analysis of clinical trials with major adverse cardiovascular events (MACE) as an outcome.. The definitions of ASCVD and MRF were heterogeneous across trials; nevertheless, the incidence of MACE was 2.8-fold higher in people with ASCVD in trials with sodium-glucose cotransporter 2 inhibitors (SGLT2is), and 3.9-fold in trials with glucagon-like peptide-1 receptor agonists (GLP-1 RA). Both SGLT2i and GLP-1 RA were associated with a significant reduction in the incidence of MACE in people with previous ASCVD [inverse variance-odds ratio 0.91, 95% confidence interval (0.86: 0.97) for SGLT2i, Mantel-Haenszel odds ratio 0.85, 95% confidence interval (0.81: 0.90) for GLP-1 RA], whereas no significant reduction was detected in those without; on the other hand, no significant difference in effect was found between the two groups as well. The sample of patients without ASCVD enrolled in clinical trials is insufficient to draw reliable conclusions in this population; however, even assuming the same benefit detected in people with ASCVD also in those with MRF, the number needed to treat would differ (35 for secondary, 99 for primary prevention of a MACE with a SGLT2i; 21 for secondary, 82 for primary prevention with a GLP-1 RA, respectively), given the difference in absolute cardiovascular risk at baseline.. The distinction between patients with ASCVD and those without ASCVD and MRF appears therefore justified by available evidence. Topics: Atherosclerosis; Cardiovascular Diseases; Diabetes Mellitus, Type 2; Glucagon-Like Peptide 1; Glucagon-Like Peptide-1 Receptor; Glucose; Humans; Hypoglycemic Agents; Secondary Prevention; Sodium-Glucose Transporter 2 Inhibitors | 2023 |
Effects of once-weekly glucagon-like peptide-1 receptor agonists on type 2 diabetes mellitus complicated with coronary artery disease: Potential role of the renin-angiotensin system.
To investigate the potential mechanism of once-weekly glucagon-like peptide-1 receptor agonists (GLP-1 RA) in the treatment of type 2 diabetes mellitus (T2DM) complicated with coronary artery disease (CAD).. We searched both Chinese and English databases for randomized controlled trials related to once-weekly GLP-1 RA for T2DM complicated with CAD to verify the safety and efficacy of GLP-1 RA. The underlying mechanism was analysed by network pharmacology.. In total, 13 studies with 35 563 participants were included in the analysis. The pooled analysis found that dulaglutide, exenatide and semaglutide outperformed placebo in cardiovascular outcomes in patients with T2DM, with a significant reduction in the incidence of non-fatal stroke (p < .00). Levels of cardiovascular risk factors were significantly reduced in the once-weekly GLP-1 RA group compared with the conventional treatment group (glycated haemoglobin: p < .00; fasting blood glucose: p < .00; weight: p < .00; systolic blood pressure: p < .00; total cholesterol: p < .00; low-density lipoprotein cholesterol: p < .00). Network pharmacology results were enriched to the renin-angiotensin system, and matrix metalloproteinase 2 and renin (REN) may be the key targets. In addition, four key targets of dulaglutide, five key targets of exenatide and two key targets of semaglutide were enriched.. Our study suggests that once-weekly GLP-1 RA may have a potential protective effect on cardiovascular events in patients with T2DM combined with CAD, possibly through the renin-angiotensin system. However, further research is needed to confirm these findings and determine cause and effect. Topics: Cholesterol; Coronary Artery Disease; Diabetes Mellitus, Type 2; Exenatide; Glucagon-Like Peptide 1; Glucagon-Like Peptide-1 Receptor; Glucagon-Like Peptides; Humans; Hypoglycemic Agents; Matrix Metalloproteinase 2; Renin-Angiotensin System | 2023 |
Whey Protein Premeal Lowers Postprandial Glucose Concentrations in Adults Compared with Water-The Effect of Timing, Dose, and Metabolic Status: a Systematic Review and Meta-analysis.
Serving whey protein before a meal in order to lower postprandial blood glucose concentrations is known as a premeal. The underlying mechanisms are only partly understood but may involve stimulation of glucagon-like peptide-1 (GLP-1), glucose-dependent insulinotropic polypeptide (GIP), and insulin secretion together with a slower gastric emptying rate.. The objective of this systematic review and meta-analysis was to review all randomized clinical trials investigating premeals with whey protein in comparison with a nonactive comparator (control) that evaluated plasma glucose, GLP-1, GIP, insulin, and/or gastric emptying rate. Secondary aims included subgroup analyses on the timing and dose of the premeal together with the metabolic state of the participants [lean, obese, and type 2 diabetes mellitus (T2DM)].. We searched EMBASE, CENTRAL, PUBMED, and clinicaltrials.gov and found 16 randomized crossover trials with a total of 244 individuals. The last search was performed on 9 August, 2022.. Whey protein premeals lowered peak glucose concentration by -1.4 mmol/L [-1.9 mmol/L; -0.9 mmol/L], and the area under the curve for glucose was -0.9 standard deviation (SD) [-1.2 SD; -0.6 SD] compared with controls (high certainty). In association with these findings, whey protein premeals elevated GLP-1 (low certainty) and peak insulin (high certainty) concentrations and slowed gastric emptying rate (high certainty) compared with controls. Subgroup analyses showed a more pronounced and prolonged glucose-lowering effect in individuals with T2DM compared with participants without T2DM. The available evidence did not elucidate the role of GIP. The protein dose used varied between 4 and 55 g, and meta-regression analysis showed that the protein dose correlated with the glucose-lowering effects.. In conclusion, whey protein premeals lower postprandial blood glucose, reduce gastric emptying rate, and increase peak insulin. In addition, whey protein premeals may elevate plasma concentrations of GLP-1. Whey protein premeals may possess clinical potential, but the long-term effects await future clinical trials. Topics: Adult; Blood Glucose; Diabetes Mellitus, Type 2; Gastric Emptying; Gastric Inhibitory Polypeptide; Glucagon; Glucagon-Like Peptide 1; Glucose; Humans; Insulin; Postprandial Period; Water; Whey Proteins | 2023 |
Incretins and cardiovascular disease: to the heart of type 2 diabetes?
Major cardiovascular outcome trials and real-life observations have proven that glucagon-like peptide-1 (GLP-1) receptor agonists (GLP-1RAs), regardless of structural GLP-1 homology, exert clinically relevant cardiovascular protection. GLP-1RAs provide cardioprotective benefits through glycaemic and non-glycaemic effects, including improved insulin secretion and action, body-weight loss, blood-pressure lowering and improved lipid profile, as well as via direct effects on the heart and vasculature. These actions are likely combined with anti-inflammatory and antioxidant properties that translate into robust and consistent reductions in atherothrombotic events, particularly in people with type 2 diabetes and established atherosclerotic CVD. GLP-1RAs may also have an impact on obesity and chronic kidney disease, conditions for which cardiovascular risk-reducing options are limited. The available evidence has prompted professional and medical societies to recommend GLP-1RAs for mitigation of the cardiovascular risk in people with type 2 diabetes. This review summarises the clinical evidence for cardiovascular protection with use of GLP-1RAs and the main mechanisms underlying this effect. Moreover, it looks into how the availability of upcoming dual and triple incretin receptor agonists might expand the possibility for cardiovascular protection in people with type 2 diabetes. Topics: Cardiovascular Diseases; Diabetes Mellitus, Type 2; Glucagon-Like Peptide 1; Glucagon-Like Peptide-1 Receptor; Humans; Hypoglycemic Agents; Incretins | 2023 |
The importance of glucose-dependent insulinotropic polypeptide receptor activation for the effects of tirzepatide.
Tirzepatide is a unimolecular co-agonist of the glucagon-like peptide-1 (GLP-1) and glucose-dependent insulinotropic polypeptide (GIP) receptors recently approved for the treatment of type 2 diabetes by the US Food and Drug Administration and the European Medicine Agency. Tirzepatide treatment results in an unprecedented improvement of glycaemic control and lowering of body weight, but the contribution of the GIP receptor-activating component of tirzepatide to these effects is uncertain. In this review, we present the current knowledge about the physiological roles of the incretin hormones GLP-1 and GIP, their receptors, and previous results of co-targeting the two incretin hormone receptors in humans. We also analyse the molecular pharmacological, preclinical and clinical effects of tirzepatide to discuss the role of GIP receptor activation for the clinical effects of tirzepatide. Based on the available literature on the combination of GLP-1 and GIP receptor activation, tirzepatide does not seem to have a classical co-activating mode of action in humans. Rather, in vitro studies of the human GLP-1 and GIP receptors reveal a biased GLP-1 receptor activation profile and GIP receptor downregulation. Therefore, we propose three hypotheses for the mode of action of tirzepatide, which can be addressed in future, elaborate clinical trials. Topics: Blood Glucose; Diabetes Mellitus, Type 2; Gastric Inhibitory Polypeptide; Glucagon; Glucagon-Like Peptide 1; Glucagon-Like Peptide-1 Receptor; Humans; Incretins | 2023 |
Is tirzepatide 15 mg the preferred treatment strategy for type 2 diabetes? A meta-analysis and trial-sequence-analysis.
The study aims to evaluate tirzepatide's efficacy and safety in treating type 2 diabetes by meta-analysis and trial-sequential-analysis (TSA).. Eight databases were searched for clinical trials on tirzepatide for type 2 diabetes with a time limit of November 2022. Revman5.3 and TSA 0.9.5.10 Beta were selected for meta-analysis and TSA.. Compared with placebo, the meta-analysis demonstrated that tirzepatide 15 mg reduced hemoglobin-type-A1C (HbA1c) (p<0.00001), fasting-serum-glucose (FSG) (p<0.00001), and weight (p<0.00001). Compared with insulin, tirzepatide 15 mg reduced HbA1c (p<0.00001), FSG (p<0.00007), and weight (p<0.00001). Compared with glucagon-like-peptide-1 receptor-agonist (GLP-1 RA), tirzepatide 15 mg reduced HbA1c (p=0.00004), FSG (p=0.001), and weight (p<0.00001). In safety endpoints, the meta-analysis revealed that adverse events (AEs) of placebo, insulin and GLP-1 RA were comparable to tirzepatide 15 mg. The total AEs (p=0.02) and gastrointestinal (GI) AEs (p=0.03) were higher in tirzepatide 15 mg than in the placebo, while hypoglycemia (<54 mg/dl) was comparable. The major adverse cardiovascular events-4 (MACE-4) (p=0.03) and hypoglycemia (<54 mg/dl) (p<0.00001) of tirzepatide 15 mg were lower when compared to insulin, while total AEs (p=0.03) were increased. Compared with GLP-1 RA, tirzepatide 15 mg was comparable in safety endpoints in total AEs and GI AEs, while hypoglycemia (<54 mg/dl) (p=0.04) was higher. TSA indicated that HgA1c, FSG, and weight benefits were conclusive. In safety endpoints, only MACE-4 and hypoglycemia (<54 mg/dl) of Tirzepatide 15 mg vs. Insulin were conclusive. Harbord regression of AEs suggested no evident publication bias (p=0.618).. Tirzepatide 15 mg reduced HbA1c and weight more effectively than placebo, insulin, and GLP-1 RA. Total AEs were higher than placebo and insulin but comparable to GLP-1 RA. Tirzepatide 15 mg is a kind of optimal strategy to treat type 2 diabetes. However, there is a need to focus on GI AEs. Topics: Clinical Trials as Topic; Diabetes Mellitus, Type 2; Glucagon-Like Peptide 1; Glycated Hemoglobin; Humans; Hypoglycemia; Insulin | 2023 |
Dorothy Hodgkin lecture 2023: The enteroendocrine system-Sensors in your guts.
Glucagon-like peptide-1 (GLP-1)-based medication is now widely employed in the treatment of type 2 diabetes and obesity. Like other gut hormones, GLP-1 is released from eneteroendocrine cells after a meal and in this review, based on the Dorothy Hodgkin lecture delivered during the annual meeting of Diabetes UK in 2023, I argue that there is sufficient spare capacity of GLP-1 and other gut hormone expressing cells that could be recruited therapeutically. Years of research has revealed several receptors expressed in enteroendocrine cells that could be targeted to stimulate hormone release: although from this research it seems unlikely to find agents that selectively boost GLP-1, release of a mixture of hormones might be the more desirable outcome anyway, given the recent promising results of new peptides combining GLP1-receptor with other gut hormone receptor activation. Alternatively, the fact that GLP-1 and peptideYY (PYY) expressing cells are found in greater density in the ileum might be exploited by increasing the delivery of chyme to the distal small intestine. Topics: Diabetes Mellitus, Type 2; Gastric Inhibitory Polypeptide; Gastrointestinal Hormones; Glucagon-Like Peptide 1; Humans; Ileum; Peptide YY | 2023 |
Clinical Outcomes with GLP-1 Receptor Agonists in Patients with Heart Failure: A Systematic Review and Meta-analysis of Randomized Controlled Trials.
Glucagon-like peptide 1 receptor agonists (GLP-1 RAs) reduce the risk of major adverse cardiovascular events (MACE) in patients with type 2 diabetes mellitus (T2DM). However, there remains uncertainty about the efficiency of GLP-1 RAs in patients with heart failure (HF).. Randomized placebo-controlled trials (RCTs) that reported the effect of GLP-1 RAs on prognosis in patients with HF were identified by searching databases. The primary outcome was defined as MACE. Trail Sequential Analysis (TSA) was used to evaluate the reality and authenticity.. Nine RCTs involving 8920 patients with HF were included. GLP-1 RAs significantly reduced the risk of MACE compared with placebo (hazard ratio [HR] 0.87, 95% confidence interval [CI] 0.77-0.98) in HF coexisting with T2DM. The benefit was not observed in all-cause death (HR 0.99, 95% CI 0.84-1.15), hospitalization for heart failure (HR 1.04, 95% CI 0.89-1.22), cardiovascular death (HR 0.95, 95% CI 0.79-1.16), myocardial infarction (HR 0.88, 95% CI 0.71-1.08), stroke (HR 1.03, 95% CI 0.75-1.43) and death or hospitalization for HF (HR 1.07, 95% CI 0.78-1.46). GLP-1 RAs did not improve the change in LVEF (mean difference [MD]): - 0.86, p = 0.12, left-ventricular end-diastolic volume (LVEDV) (MD: 3.54, p = 0.11), left-ventricular end-systolic volume (LVESV) (MD: 2.78, p = 0.07) or N-terminal pro-B-type natriuretic peptide (NT-proBNP) (MD: - 140.36, p = 0.08). However, GLP-1 RAs significantly increased the change in the 6-min walk test (MWT) distance (MD: 19.74, p = 0.002). In the subgroup analyses, human GLP-1 RAs, but not nonhuman GLP-1 RAs, reduced the risk of MACE in patients with HF (p interaction = 0.11). Grading of Recommendations Assessment, Development and Evaluation (GRADE) showed moderate certainty for MACE, all-cause death and hospitalization for HF. Trail Sequential Analysis revealed that there may be a high possibility of false positive results for MACE.. Compared with placebo, GLP-1 RAs may reduce the risk of MACE in patients with HF coexisting with T2DM, with a more significant efficiency of human GLP-1 RAs. More RCTs are needed to assess the cardiovascular benefits of GLP-1 RAs in HF, regardless of T2DM.. The protocol for this meta-analysis is registered on PROSPERO [CRD42022357886]. Topics: Diabetes Mellitus, Type 2; Glucagon-Like Peptide 1; Glucagon-Like Peptide-1 Receptor; Heart Failure; Humans; Randomized Controlled Trials as Topic | 2023 |
Down the rabbit hole: reviewing the evidence for primary prevention of cardiovascular disease in people with obesity.
Obesity is a prevalent chronic disorder and a well-known risk factor for cardiovascular disease. However, the evidence of treating obesity for primary prevention of major cardiovascular events is still scarce and controversial. In this review, we provided a comprehensive description of the current evidence in treating obesity regarding cardiovascular protection. Bariatric surgery appears to be the most robust method to reduce events in people without established cardiovascular disease. High compliance to lifestyle interventions can further reduce cardiovascular risk. Concerning pharmacological therapies, a post hoc analysis from SUSTAIN-6 and a meta-analysis from STEP trials suggest that semaglutide, a GLP-1 receptor agonist, could reduce cardiovascular events in people without established cardiovascular disease. The first study addressed specifically a high-risk population with diabetes and, the second, low- or intermediary-risk individuals without diabetes. Tirzepatide, a novel dual GIP/GLP-1 agonist, although not yet tested in specific cardiovascular outcomes trials, could be an alternative since it induces loss in weight similar to the achieved by bariatric surgery. Therefore, extrapolated data in distinct baseline cardiovascular risk populations suggest that these two drugs could be used in primary prevention with the aim of preventing cardiovascular events, but the grade of this evidence is still low. Specifically designed studies are needed to address this specific topic. Topics: Cardiovascular Diseases; Diabetes Mellitus; Diabetes Mellitus, Type 2; Glucagon-Like Peptide 1; Humans; Hypoglycemic Agents; Obesity; Primary Prevention | 2023 |
GLP-1 receptor agonists effect on cognitive function in patients with and without type 2 diabetes.
Glucagon-like peptide 1 (GLP-1) is a hormone of the incretin family, secreted in response to nutrient ingestion, and plays a role in metabolic homeostasis. GLP-1 receptor agonist has a peripheral and a central action, including stimulation of glucose-dependent insulin secretion and insulin biosynthesis, inhibition of glucagon secretion and gastric emptying, and inhibition of food intake. Through their mechanism, their use in the treatment of type 2 diabetes has been extended to the management of obesity, and numerous trials are being conducted to assess their cardiovascular effect. Type 2 diabetes appears to share common pathophysiological mechanisms with the development of cognitive disorders, such as Alzheimer's and Parkinson's disease, related to insulin resistance. In this review, we aim to examine the pathological features between type 2 diabetes and dementia, GLP-1 central effects, and analyze the relevant literature about the effect of GLP-1 analogs on cognitive function of patients with type 2 diabetes but also without. Results tends to show an improvement in some brain markers (e.g. hippocampal connections, cerebral glucose metabolism, hippocampal activation on functional magnetic resonance imaging), but without being able to demonstrate a strong correlation to cognitive scores. Some epidemiological studies suggest that GLP-1 receptor agonists may offer a protective effect, by delaying progression to dementia when diabetic patients are treated with GLP-1 receptor agonists. Ongoing trials are in progress and may provide disease-modifying care for Alzheimer's disease and Parkinson's disease patients in the future. Topics: Cognition; Dementia; Diabetes Mellitus, Type 2; Glucagon-Like Peptide 1; Glucagon-Like Peptide-1 Receptor; Humans; Insulin; Parkinson Disease | 2023 |
Glucagon-like peptide-1 receptor agonists and safety in the preconception period.
Glucagon-like peptide-1 (GLP-1) receptor agonists (RAs) are becoming increasingly popular for the treatment of type II diabetes and obesity. Body mass index (BMI) thresholds at in vitro fertilization (IVF) clinics may further drive the use of these medications before infertility treatment. However, most clinical guidance regarding optimal time to discontinue these medications prior to conception is based on animal data. The purpose of this review was to evaluate the literature for evidence-based guidance regarding the preconception use of GLP-1 RA.. 16 articles were found in our PubMed search, 10 were excluded as they were reviews or reported on animal data. Included were 3 case reports detailing pregnancy outcomes in individual patients that conceived while on a GLP-1 RA and 2 randomized controlled trials (RCTs) and a follow-up study to one of the RCTs that reported on patients randomized to GLP-1 RA or metformin prior to conception. No adverse pregnancy or neonatal outcomes were reported.. There are limited data from human studies to guide decision-making regarding timing of discontinuation of GLP-1 RA before conception. Studies focused on pregnancy and neonatal outcomes would provide additional information regarding a safe washout period. Based on the available literature a 4-week washout period prior to attempting conception may be considered for the agents reviewed in this publication. Topics: Animals; Diabetes Mellitus, Type 2; Female; Glucagon-Like Peptide 1; Glucagon-Like Peptide-1 Receptor; Humans; Hypoglycemic Agents; Infant, Newborn; Metformin; Pregnancy; Randomized Controlled Trials as Topic | 2023 |
Mechanisms of action of incretin receptor based dual- and tri-agonists in pancreatic islets.
Simultaneous activation of the incretin G-protein-coupled receptors (GPCRs) via unimolecular dual-receptor agonists (UDRA) has emerged as a new therapeutic approach for type 2 diabetes. Recent studies also advocate triple agonism with molecules also capable of binding the glucagon receptor. In this scoping review, we discuss the cellular mechanisms of action (MOA) underlying the actions of these novel and therapeutically important classes of peptide receptor agonists. Clinical efficacy studies of several UDRAs have demonstrated favorable results both as monotherapies and when combined with approved hypoglycemics. Although the additive insulinotropic effects of dual glucagon-like peptide-1 receptor (GLP-1R) and glucose-dependent insulinotropic peptide receptor (GIPR) agonism were anticipated based on the known actions of either glucagon-like peptide-1 (GLP-1) or glucose-dependent insulinotropic peptide (GIP) alone, the additional benefits from GCGR were largely unexpected. Whether additional synergistic or antagonistic interactions among these G-protein receptor signaling pathways arise from simultaneous stimulation is not known. The signaling pathways affected by dual- and tri-agonism require more trenchant investigation before a comprehensive understanding of the cellular MOA. This knowledge will be essential for understanding the chronic efficacy and safety of these treatments. Topics: Diabetes Mellitus, Type 2; Gastric Inhibitory Polypeptide; Glucagon-Like Peptide 1; Glucagon-Like Peptide-1 Receptor; Humans; Incretins; Islets of Langerhans; Receptors, Glucagon | 2023 |
Effectiveness and cost-effectiveness of six GLP-1RAs for treatment of Chinese type 2 diabetes mellitus patients that inadequately controlled on metformin: a micro-simulation model.
To systematically estimate and compare the effectiveness and cost-effectiveness of the glucagon-like peptide-1 receptor agonists (GLP-1RAs) approved in China and to quantify the relationship between the burden of diabetic comorbidities and glycosylated hemoglobin (HbA1c) or body mass index (BMI).. To estimate the costs (US dollars, USD) and quality-adjusted life years (QALY) for six GLP-1RAs (exenatide, loxenatide, lixisenatide, dulaglutide, semaglutide, and liraglutide) combined with metformin in the treatment of patients with type 2 diabetes mellitus (T2DM) which is inadequately controlled on metformin from the Chinese healthcare system perspective, a discrete event microsimulation cost-effectiveness model based on the Chinese Hong Kong Integrated Modeling and Evaluation (CHIME) simulation model was developed. A cohort of 30,000 Chinese patients was established, and one-way sensitivity analysis and probabilistic sensitivity analysis (PSA) with 50,000 iterations were conducted considering parameter uncertainty. Scenario analysis was conducted considering the impacts of research time limits. A network meta-analysis was conducted to compare the effects of six GLP-1RAs on HbA1c, BMI, systolic blood pressure, and diastolic blood pressure. The incremental net monetary benefit (INMB) between therapies was used to evaluate the cost-effectiveness. China's. During a lifetime, the cost for a patient ranged from USD 42,092 with loxenatide to USD 47,026 with liraglutide, while the QALY gained ranged from 12.50 with dulaglutide to 12.65 with loxenatide. Compared to exenatide, the INMB of each drug from highest to lowest were: loxenatide (USD 1,124), dulaglutide (USD -1,418), lixisenatide (USD -1,713), semaglutide (USD -4,298), and liraglutide (USD -4,672). Loxenatide was better than the other GLP-1RAs in the base-case analysis. Sensitivity and scenario analysis results were consistent with the base-case analysis. Overall, the price of GLP-1RAs most affected the results. Medications with effective control of HbA1c or BMI were associated with a significantly smaller disease burden (. Loxenatide combined with metformin was identified as the most economical choice, while the long-term health benefits of patients taking the six GLP-1RAs are approximate. Topics: Body Mass Index; Comorbidity; Computer Simulation; Cost of Illness; Cost-Benefit Analysis; Cost-Effectiveness Analysis; Diabetes Mellitus, Type 2; Drug Therapy, Combination; East Asian People; Exenatide; Glucagon-Like Peptide 1; Glucagon-Like Peptide-1 Receptor; Glycated Hemoglobin; Glycemic Control; Humans; Hypoglycemic Agents; Liraglutide; Metformin; Quality-Adjusted Life Years; Treatment Outcome | 2023 |
Comparative efficacy of glucose-lowering drugs on liver steatosis as assessed by means of magnetic resonance imaging in patients with type 2 diabetes mellitus: systematic review and network meta-analysis.
To assess the comparative efficacy of glucose-lowering drugs on liver steatosis as assessed by means of magnetic resonance imaging (MRI) in patients with T2D.. We searched several databases and grey literature sources. Eligible trials had at least 12 weeks of intervention, included patients with T2D, and assessed the efficacy of glucose-lowering drugs as monotherapies. The primary outcome of interest was absolute reduction in liver fat content (LFC), assessed by means of MRI. Secondary efficacy outcomes were reduction in visceral and subcutaneous adipose tissue. We performed random effects frequentist network meta-analyses to estimate mean differences (MDs) with 95% confidence intervals (CIs). We ranked treatments based on P-scores.. We included 29 trials with 1906 patients. Sodium-glucose cotransporter-2 (SGLT-2) inhibitors (P-score 0.84) and glucagon-like peptide-1 receptor agonists (GLP-1 RAs) (0.71) were the most efficacious in terms of liver fat content reduction. Among individual agents, empagliflozin was the most efficacious (0.86) and superior to pioglitazone (MD -5.7, 95% CI -11.2 to -0.3) (very low confidence). GLP-1 RAs had also the most favorable effects on visceral and subcutaneous adipose tissue.. GLP-1 RAs and SGLT-2 inhibitors seem to be the most efficacious glucose-lowering drugs for liver steatosis in patients with T2D. Assessment of their efficacy on NAFLD in patients irrespective of presence of T2D is encouraged. Topics: Diabetes Mellitus, Type 2; Glucagon-Like Peptide 1; Glucose; Humans; Hypoglycemic Agents; Network Meta-Analysis; Non-alcoholic Fatty Liver Disease | 2023 |
Targeting redox imbalance in neurodegeneration: characterizing the role of GLP-1 receptor agonists.
Reactive oxygen species (ROS) have emerged as essential signaling molecules regulating cell survival, death, inflammation, differentiation, growth, and immune response. Environmental factors, genetic factors, or many pathological condition such as diabetes increase the level of ROS generation by elevating the production of advanced glycation end products, reducing free radical scavengers, increasing mitochondrial oxidative stress, and by interfering with DAG-PKC-NADPH oxidase and xanthine oxidase pathways. Oxidative stress, and therefore the accumulation of intracellular ROS, determines the deregulation of several proteins and caspases, damages DNA and RNA, and interferes with normal neuronal function. Furthermore, ROS play an essential role in the polymerization, phosphorylation, and aggregation of tau and amyloid-beta, key mediators of cognitive function decline. At the neuronal level, ROS interfere with the DNA methylation pattern and various apoptotic factors related to cell death, promoting neurodegeneration. Only few drugs are able to quench ROS production in neurons. The cross-linking pathways between diabetes and dementia suggest that antidiabetic medications can potentially treat dementia. Among antidiabetic drugs, glucagon-like peptide-1 receptor agonists (GLP-1RAs) have been found to reduce ROS generation and ameliorate mitochondrial function, protein aggregation, neuroinflammation, synaptic plasticity, learning, and memory. The incretin hormone glucagon-like peptide-1 (GLP-1) is produced by the enteroendocrine L cells in the distal intestine after food ingestion. Upon interacting with its receptor (GLP-1R), it regulates blood glucose levels by inducing insulin secretion, inhibiting glucagon production, and slowing gastric emptying. No study has evidenced a specific GLP-1RA pathway that quenches ROS production. Here we summarize the effects of GLP-1RAs against ROS overproduction and discuss the putative efficacy of Exendin-4, Lixisenatide, and Liraglutide in treating dementia by decreasing ROS. Topics: Amyloid beta-Peptides; Dementia; Diabetes Mellitus; Diabetes Mellitus, Type 2; Glucagon-Like Peptide 1; Glucagon-Like Peptide-1 Receptor; Humans; Hypoglycemic Agents; Oxidation-Reduction; Reactive Oxygen Species; Transcription Factors | 2023 |
Glucagon-like peptide-1/glucose-dependent insulinotropic polypeptide receptor co-agonists for cardioprotection, type 2 diabetes and obesity: a review of mechanisms and clinical data.
Glucagon-like peptide-1 receptor agonists (GLP-1RAs) are approved for the management of type 2 diabetes (T2D) and obesity, and some are recommended for cardiorenal risk reduction in T2D. To enhance the benefits with GLP-RA mono-agonist therapy, GLP-1/glucose-dependent insulinotropic polypeptide (GIP) receptor co-agonists are in development to capitalize on the synergism of GLP-1 and GIP agonism. We review the mechanisms of action and clinical data for GLP-1/GIP receptor co-agonists in T2D and obesity and their potential role in cardiovascular protection.. Tirzepatide, a first-in-class unimolecular GLP-1/GIP receptor co-agonist, is approved for T2D and is awaiting approval for obesity management. Phase 3 trials in T2D cohorts revealed significant reductions in glycemia and body weight and superiority compared with GLP-1R mono-agonism with semaglutide. Tirzepatide has demonstrated significant body weight reductions in individuals with obesity but not diabetes. It enhances lipid metabolism, reduces blood pressure, and lowers liver fat content. Pooled phase 2/3 data showed cardiovascular safety in T2D while a post hoc analysis suggested tirzepatide slows the decline of kidney function in T2D.. GLP-1/GIP receptor co-agonists are a novel addition to the diabetes and obesity armamentarium. The cardiorenal-metabolic benefits position them as promising multiprong tools for metabolically complex individuals with chronic vascular complications. Topics: Diabetes Mellitus, Type 2; Glucagon-Like Peptide 1; Humans; Obesity; Receptors, Gastrointestinal Hormone | 2023 |
Synergistic Combinations of Gut- and Pancreas-Hormone-Based Therapies: Advancements in Treatments for Metabolic Diseases.
Metabolic diseases, such as obesity, type 2 diabetes mellitus (T2DM), cardiovascular disease, and liver disease, have become increasingly prevalent around the world. As an alternative to bariatric surgery, glucagon-like peptide 1 (GLP-1) receptor agonists have been at the forefront of weight loss medication to combat these metabolic complications. Recently, there has been an exciting rapid emergence of new weight loss medications that combine GLP-1 receptor (GLP-1R) agonists with other gut- and pancreatic-derived hormones, such as glucose-dependent insulinotropic polypeptide (GIP) and glucagon (GCG) receptor agonists. Dual-agonist (GLP-1/GIP and GLP-1/GCG) and tri-agonist (GLP-1/GIP/GCG) administration generally result in greater weight loss, reduction of blood sugar and lipid levels, restoration of tissue function, and improvement in whole-body substrate metabolism compared to when GLP-1R agonists are used alone. The aim of this review is to summarize the recent literature of both preclinical and clinical studies on how these emerging gut-peptide therapies further improve weight loss and metabolic health outcomes for various metabolic diseases. Topics: Anti-Obesity Agents; Diabetes Mellitus, Type 2; Gastric Inhibitory Polypeptide; Glucagon-Like Peptide 1; Glucagon-Like Peptide-1 Receptor; Humans; Pancreas; Weight Loss | 2023 |
[From GLP1 receptor agonists to triple hormone receptor activation supplemented with glucagon receptor agonism.]
Following the introduction of mono- and then dual hormone (incretin) receptor agonists into therapy, attention was turned to multiple receptor stimulation, with the additional activation of the glucagon receptor, as a new option for the pharmaceutical treatment of type 2 diabetes and obesity. In addition to its role in carbohydrate metabolism, the article reviews the other important physiological tasks of glucagon, especially its participation in intrainsular paracrine regulation, energy expenditure and the shaping of appetite and food consumption. It covers the potential benefits of the triple combination and briefly touches data on the efficacy and safety of the first triple receptor agonist drug, retatrutide, in preclinical human studies. Further confirmation of the promising results may represent progress in the treatment of these forms of disease and their accompanying conditions, such as steatosis hepatis. Orv Hetil. 2023; 164(42): 1656-1664.. A mono-, majd duális hormon(inkretin)receptor-agonisták terápiába állítását követően a 2-es típusú diabetes és az elhízás gyógyszeres kezelésének egyik új lehetőségeként a hármashormonreceptor-stimulálás, a glükagonreceptor kiegészítő aktiválása felé fordult a figyelem. A dolgozat a szénhidrát-anyagcserében betöltött szerepe mellett áttekinti a glükagon további élettani feladatait, kiemelten az intrainsularis parakrin szabályozásban, az energiaforgalomban és az étvágy befolyásolásában való részvételét. Kitér a hármas kombináció lehetséges előnyeire, és röviden érinti az első hármashormonreceptor-agonistával, a retatrutiddal kapcsolatos preklinikai humán vizsgálatok hatékonysággal és biztonságossággal kapcsolatos adataira is. A biztató eredmények további megerősítése előrelépést jelenthet e kórformák és kísérő állapotaik – így a steatosis hepatis − kezelésében. Orv Hetil. 2023; 164(42): 1656–1664. Topics: Diabetes Mellitus, Type 2; Glucagon-Like Peptide 1; Glucagon-Like Peptide-1 Receptor; Humans; Obesity; Receptors, Glucagon | 2023 |
Gastrointestinal adverse events of tirzepatide in the treatment of type 2 diabetes mellitus: A meta-analysis and trials sequential analysis.
Tirzepatide (TZP) is a novel drug for type 2 diabetes mellitus (T2DM), but the gastrointestinal (GI) adverse events (AEs) is a limiting factor in clinical application. Therefore, this study systematically evaluated the GI AEs of TZP for T2DM.. Clinical trials of TZP for T2DM were retrieved from eight databases published only from the establishment of the database to February 2023. Revman5.3 and TSA0.9.5.10 Beta were used for meta-analysis and trials sequential analysis (TSA).. Meta-analysis showed that compared with placebo, total GI AEs, nausea, decreased appetite, constipation and vomiting were significantly higher in all dose groups of TZP (P < .05), while abdominal pain and abdominal distension were comparable (P > .05). TSA showed that the differences in total GI AEs, nausea, decreased appetite and constipation were conclusive. Compared with insulin, nausea, diarrhea, vomiting and decreased appetite were significantly increased in all doses of TZP (P < .05), and dyspepsia was significantly increased with TZP 15 mg (P < .05). TSA showed that these differences were all conclusive. Compared with GLP-1 RA, decreased appetite was significantly higher with TZP 5 mg, total GI AEs, decreased appetite and diarrhea were significantly higher with TZP 10 mg (P < .05), while nausea, vomiting, dyspepsia and constipation were significantly different in all dose groups, abdominal pain were not significantly different (P < .05) and TSA showed no conclusive results in this group.. The GI AEs of TZP were significantly higher than those of placebo and insulin, but comparable to GLP-1 RA. Nausea, diarrhea and decreased appetite are very common GI AEs of TZP, and the incidence is positively correlated with dose. GI AEs of TZP decrease gradually over time, so long-term steady medication may be expected to reduce GI AEs. Topics: Abdominal Pain; Clinical Trials as Topic; Constipation; Diabetes Mellitus, Type 2; Diarrhea; Dyspepsia; Glucagon-Like Peptide 1; Humans; Hypoglycemic Agents; Insulins; Nausea; Vomiting | 2023 |
Effect of long-acting versus short-acting glucagon-like peptide-1 receptor agonists on improving body weight and related metabolic parameters in type 2 diabetes: A head-to-head meta-analysis.
Glucagon-like peptide-1 receptor agonists (GLP-1RAs) showed great value in treating nonalcoholic fatty liver disease (NAFLD). We aimed to compare the effectiveness of long-acting and short-acting GLP-1RAs on improving body weight and related metabolic parameters in patients with type 2 diabetes (T2DM) as a reference for the treatment of NAFLD with T2DM.. We searched eligible randomized controlled trials (RCTs) in PubMed, Embase, Cochrane and web of science database until August 2023. The risk of bias of included RCTs were assessed by the Risk Assessment of Cochrane Review items. We mainly drew forest plots to compare the effects of long and short acting GLP-1 RAs using RevMan 5.4.. Twelve RCTs involving 2751 patients were included in our meta-analysis. Compared with short-acting GLP-1 RAs, the long-acting group was better in body weight (P < .00001, MD = -0.65, 95% confidence interval [CI] [-0.90, -0.40], I2 = 20%), and the same results in glycosylated hemoglobin (HbA1c) (P < .00001, MD = -0.43, 95% CI [-0.54, -0.33], I2 = 55%) and fasting plasma glucose (FPG) (P < .00001, MD = -0.77, 95% CI [-1.01, -0.52], I2 =70%). For the lipid parameters, long-acting drugs lowered cholesterol (TC) (P = .02, SMD = -0.19, 95% CI [-0.35, -0.03], I2 =57%) and low-density lipoprotein (LDL) (P = .02, SMD = -0.17, 95% CI [-0.33, -0.02], I2 =51%) more significantly compared with short-acting drugs. But treatment differences were not significant in triglycerides (TG) (P = .40, SMD = -0.05, 95% CI [-0.15, -0.06], I2 = 0%), and high-density lipoprotein (HDL) (P = .85, SMD = -0.01, 95% CI [-0.11, -0.09], I2 = 0%).. Long-acting GLP-1RAs may be more promise than short-acting GLP-1RAs in improving weight and related metabolic parameters. Topics: Body Weight; Diabetes Mellitus, Type 2; Glucagon-Like Peptide 1; Glucagon-Like Peptide-1 Receptor; Humans; Hypoglycemic Agents; Non-alcoholic Fatty Liver Disease | 2023 |
Glucagon-Like Peptide-1 Receptor Agonist and Risk of Diabetic Retinopathy in Patients with Type 2 Diabetes Mellitus: A Systematic Review and Meta-analysis of Randomized Placebo-Controlled Trials.
Glucagon-like peptide 1 receptor agonists (GLP-1RAs) exhibit glucose-lowering, weight-reducing, and blood pressure-lowering effects. Nevertheless, a debate exists concerning the association between GLP-1RA treatment and the risk of diabetic retinopathy (DR) in patients diagnosed with type 2 diabetes mellitus (T2DM).. To ascertain the risk of DR in patients with T2DM undergoing GLP-1RA treatment, we conducted a meta-analysis utilizing data derived from randomized placebo-controlled studies (RCTs).. A comprehensive literature search was conducted using PubMed, Cochrane Library, Web of Science, and EMBASE. We focused on RCTs involving the use of GLP-1RAs in patients with T2DM. Utilizing R software, we compared the risk of DR among T2DM patients undergoing GLP-1RA treatment. The Cochrane risk of bias method was employed to assess the research quality.. The meta-analysis incorporated data from 20 RCTs, encompassing a total of 24,832 T2DM patients. Across all included trials, randomization to GLP-1 RA treatment did not demonstrate an increased risk of DR (odds ratio = 1.17; 95% CI 0.98-1.39). Furthermore, no significant heterogeneity or publication bias was detected in the analysis.. The results of this systematic review and meta-analysis indicate that the administration of GLP-1 RA is not associated with an increased risk of DR. PROSPERO REGISTRATION IDENTIFIER: CRD42023413199. Topics: Diabetes Mellitus, Type 2; Diabetic Retinopathy; Glucagon-Like Peptide 1; Glucagon-Like Peptide-1 Receptor; Glucagon-Like Peptide-1 Receptor Agonists; Humans; Hypoglycemic Agents; Randomized Controlled Trials as Topic | 2023 |
A review of recent research and development on GLP-1 receptor agonists-sustained-release microspheres.
Glucagon-like peptide-1 receptor agonists (GLP-1 RAs) are increasingly used in treating type 2 diabetes (T2D). However, owing to their limited oral bioavailability, most commercially available GLP-1 RAs are administered through frequent subcutaneous injections, which may result in poor patient compliance during clinical treatment. To improve patients' compliance, sustained-release GLP-1 RA-loaded microspheres have been explored. This review is an overview of recent progress and research in GLP-1 RA-loaded microspheres. First, the fabrication methods of GLP-1 RA-loaded microspheres including the coacervation method, emulsion-solvent evaporation method based on agitation, premix membrane emulsification technology, spray drying, microfluidic droplet technology, and supercritical fluid technology are summarized. Next, the strategies for maintaining GLP-1 RAs' stability and activity in microspheres by adding additives and PEGylation are reviewed. Finally, the effect of particle size, drug distribution, the internal structure of microspheres, and the hydrogel/microsphere composite strategy on improved release behavior is summarized. Topics: Delayed-Action Preparations; Diabetes Mellitus, Type 2; Glucagon-Like Peptide 1; Glucagon-Like Peptide-1 Receptor; Humans; Microspheres; Research | 2023 |
Obesity Management in Adults: A Review.
Obesity affects approximately 42% of US adults and is associated with increased rates of type 2 diabetes, hypertension, cardiovascular disease, sleep disorders, osteoarthritis, and premature death.. A body mass index (BMI) of 25 or greater is commonly used to define overweight, and a BMI of 30 or greater to define obesity, with lower thresholds for Asian populations (BMI ≥25-27.5), although use of BMI alone is not recommended to determine individual risk. Individuals with obesity have higher rates of incident cardiovascular disease. In men with a BMI of 30 to 39, cardiovascular event rates are 20.21 per 1000 person-years compared with 13.72 per 1000 person-years in men with a normal BMI. In women with a BMI of 30 to 39.9, cardiovascular event rates are 9.97 per 1000 person-years compared with 6.37 per 1000 person-years in women with a normal BMI. Among people with obesity, 5% to 10% weight loss improves systolic blood pressure by about 3 mm Hg for those with hypertension, and may decrease hemoglobin A1c by 0.6% to 1% for those with type 2 diabetes. Evidence-based obesity treatment includes interventions addressing 5 major categories: behavioral interventions, nutrition, physical activity, pharmacotherapy, and metabolic/bariatric procedures. Comprehensive obesity care plans combine appropriate interventions for individual patients. Multicomponent behavioral interventions, ideally consisting of at least 14 sessions in 6 months to promote lifestyle changes, including components such as weight self-monitoring, dietary and physical activity counseling, and problem solving, often produce 5% to 10% weight loss, although weight regain occurs in 25% or more of participants at 2-year follow-up. Effective nutritional approaches focus on reducing total caloric intake and dietary strategies based on patient preferences. Physical activity without calorie reduction typically causes less weight loss (2-3 kg) but is important for weight-loss maintenance. Commonly prescribed medications such as antidepressants (eg, mirtazapine, amitriptyline) and antihyperglycemics such as glyburide or insulin cause weight gain, and clinicians should review and consider alternatives. Antiobesity medications are recommended for nonpregnant patients with obesity or overweight and weight-related comorbidities in conjunction with lifestyle modifications. Six medications are currently approved by the US Food and Drug Administration for long-term use: glucagon-like peptide receptor 1 (GLP-1) agonists (semaglutide and liraglutide only), tirzepatide (a glucose-dependent insulinotropic polypeptide/GLP-1 agonist), phentermine-topiramate, naltrexone-bupropion, and orlistat. Of these, tirzepatide. Obesity affects approximately 42% of adults in the US. Behavioral interventions can attain approximately 5% to 10% weight loss, GLP-1 agonists and glucose-dependent insulinotropic polypeptide/GLP-1 receptor agonists can attain approximately 8% to 21% weight loss, and bariatric surgery can attain approximately 25% to 30% weight loss. Comprehensive, evidence-based obesity treatment combines behavioral interventions, nutrition, physical activity, pharmacotherapy, and metabolic/bariatric procedures as appropriate for individual patients. Topics: Adult; Anti-Obesity Agents; Body Mass Index; Cardiovascular Diseases; Diabetes Mellitus, Type 2; Female; Gastric Balloon; Glucagon-Like Peptide 1; Glucose; Humans; Hypertension; Male; Obesity; Obesity Management; Overweight; Peptides; United States; Weight Loss | 2023 |
Pharmacological and Clinical Studies of Medicinal Plants That Inhibit Dipeptidyl Peptidase-IV.
Dipeptidyl peptidase IV (DPP-IV) is an enzyme responsible for the degradation of the incretin hormone glucagon-like peptide-1 (GLP-1). DPP-IV plays a significant role in regulating blood glucose levels by modulating the activity of GLP-1. In the context of diabetes, DPP-IV inhibitors effectively block the activity of DPP-IV, hence mitigating the degradation of GLP-1. This, in turn, leads to an extension of GLP-1's duration of action, prolongs gastric emptying, enhances insulin sensitivity, and ultimately results in the reduction of blood glucose levels. Nonetheless, reported adverse events of DPP-IV inhibitors on T2DM patients make it essential to understand the activity and mechanism of these drugs, particularly viewed from the perspective of finding the effective and safe add-on medicinal plants, to be implemented in clinical practice. This review is intended to bring forth a thorough overview of plants that work by reducing DPP-IV activity, from computational technique, enzymatic study, animal experiments, and studies in humans. The articles were searched on PubMed using "Plants", "DPP-IV", "DPP-IV inhibitor", "GLP-1", "Type 2 diabetes", "diabetes", "in silico", "in vitro", "in vivo", "studies in human", "clinical study" as the query words, and filtered for ten years of publication period. Eighteen plants showed inhibition against DPP-IV as proven by in silico, in vitro, and in vivo studies; however, only ten plants were reported for efficacy in clinical studies. Several plant-based DPP-IV inhibitors, eg, Topics: Animals; Blood Glucose; Diabetes Mellitus, Type 2; Dipeptidyl Peptidase 4; Dipeptidyl-Peptidase IV Inhibitors; Glucagon-Like Peptide 1; Humans; Hypoglycemic Agents; Plants, Medicinal | 2023 |
GLP-1 RAs and SGLT2i: two antidiabetic agents associated with immune and inflammation modulatory properties through the common AMPK pathway.
Immune cells and other cells respond to nutrient deprivation by the classic catabolic pathway of AMPK (Adenosine monophosphate kinase). This kinase is a pivotal regulator of glucose and fatty acids metabolism, although current evidence highlights its role in immune regulation. Indeed AMPK, through activation of Foxo1 (Forkhead box O1) and Foxo3 (Forkhead box O3), can regulate FOXP3, the key gene for differentiation and homeostasis of Tregs (T regulators lymphocytes). The relevance of Tregs in the onset of T1D (Type 1 diabetes) is well-known, while their role in the pathogenesis of T2D (Type 2 diabetes) is not fully understood yet. However, several studies seem to indicate that Tregs may oppose the progression of diabetic complications by mitigating insulin resistance, atherosclerosis, and damage to target organs (as in kidney disease). Hence, AMPK and AMPK-activating agents may play a role in the regulation of the immune system. The connection between metformin and AMPK is historically known; however, this link and the possible related immune effects are less studied about SGLT2i (Sodium-glucose co-transport 2 inhibitors) and GLP1-RAs (Glucagon-like peptide-1 receptor agonists). Actual evidence shows that the negative caloric balance, induced by SGLT2i, can activate AMPK. Conversely and surprisingly, an anabolizing agent like GLP-1RAs can also upregulate this kinase through cAMP (Cyclic adenosine monophosphate) accumulation. Therefore, both these drugs can likely lead to the activation of the AMPK pathway and consequential proliferation of Tregs. These observations seem to confirm not only the metabolic but also the immunoregulatory effects of these new antidiabetic agents. Topics: Adenosine Monophosphate; AMP-Activated Protein Kinases; Diabetes Mellitus, Type 2; Glucagon-Like Peptide 1; Glucose; Humans; Hypoglycemic Agents | 2023 |
The pleiotropic of GLP-1/GLP-1R axis in central nervous system diseases.
Topics: Diabetes Mellitus, Type 2; Glucagon-Like Peptide 1; Glucagon-Like Peptide-1 Receptor; Humans; Islets of Langerhans; Spinal Cord Injuries; Transcription Factors | 2023 |
Vascular and metabolic effects of SGLT2i and GLP-1 in heart failure patients.
Alterations of endothelial function, inflammatory activation, and nitric oxide-cyclic guanosine monophosphate (NO-cGMP) pathway are involved in the pathophysiology of heart failure. Metabolic alterations have been studied in the myocardium of heart failure (HF) patients; alterations in ketone body and amino acid/protein metabolism have been described in patients affected by HF, as well as mitochondrial dysfunction and other modified metabolic signaling. However, their possible contributions toward cardiac function impairment in HF patients are not completely known. Recently, sodium-glucose co-transporter 2 inhibitors (SGLT2i) and glucagon-like peptide-1 (GLP-1) receptor agonists (RAs) have emerged as a new class of drugs designed to treat patients with type 2 diabetes (T2D), but have also been shown to be protective against HF-related events and CV mortality. To date, the protective cardiovascular effects of these drugs in patients with and without T2D are not completely understood and several mechanisms have been proposed. In this review, we discuss on vascular and metabolic effects of SGLT2i and GLP-1 in HF patients. Topics: Cardiovascular Diseases; Cardiovascular System; Diabetes Mellitus, Type 2; Glucagon-Like Peptide 1; Heart Failure; Humans; Sodium-Glucose Transporter 2 Inhibitors | 2023 |
Oral Semaglutide in the Management of Type 2 DM: Clinical Status and Comparative Analysis.
In the incretin system, Glucagon-like peptide-1 (GLP-1) is a hormone that inhibits the release of glucagon and regulates glucose-dependent insulin secretion. In type 2 diabetes, correcting the impaired incretin system using GLP-1 agonist is a well-defined therapeutic strategy.. This review article aims to discuss the mechanism of action, key regulatory events, clinical trials for glycaemic control, and comparative analysis of semaglutide with the second-line antidiabetic drugs.. Semaglutide is a glucagon-like peptide 1 (GLP-1) receptor agonist with enhanced glycaemic control in diabetes patients. In 2019, USFDA approved the first oral GLP-1 receptor agonist, semaglutide, to be administered as a once-daily tablet. Further, recent studies highlight the ability of semaglutide to improve Glycemic control in obese patients with a reduction in body weight. Still, in clinical practice, in the type 2 DM treatment paradigm, the impact of oral semaglutide remains unidentified. This review article discusses the mechanism of action, pharmacodynamics, key regulatory events, and clinical trials regarding glycaemic control.. The review highlights the comparative analysis of semaglutide with the existing second- line drugs for the management of type 2 diabetes mellitus by stressing its benefits and adverse events. Topics: Diabetes Mellitus, Type 2; Glucagon-Like Peptide 1; Glucagon-Like Peptide-1 Receptor; Glucagon-Like Peptides; Humans; Hypoglycemic Agents; Incretins | 2022 |
The role of glucagon-like peptide 1 (GLP-1) in addictive disorders.
Drug, alcohol and tobacco use disorders are a global burden affecting millions of people. Despite decades of research, treatment options are sparse or missing, and relapse rates are high. Glucagon-like peptide 1 (GLP-1) is released in the small intestine, promotes blood glucose homeostasis, slows gastric emptying and reduces appetite. GLP-1 receptor agonists approved for treating Type 2 diabetes mellitus and obesity have received attention as a potential anti-addiction treatment. Studies in rodents and non-human primates have demonstrated a reduction in intake of alcohol and drugs of abuse, and clinical trials have been initiated to investigate whether the preclinical findings can be translated to patients. This review will give an overview of current findings and discuss the possible mechanisms of action. We suggest that effects of GLP-1 in alcohol and substance use disorders is mediated centrally, at least partly through dopamine signalling, but precise mechanisms are still to be uncovered. LINKED ARTICLES: This article is part of a themed issue on GLP1 receptor ligands (BJP 75th Anniversary). To view the other articles in this section visit http://onlinelibrary.wiley.com/doi/10.1111/bph.v179.4/issuetoc. Topics: Animals; Behavior, Addictive; Diabetes Mellitus, Type 2; Ethanol; Glucagon-Like Peptide 1; Glucagon-Like Peptide-1 Receptor; Humans | 2022 |
GLP-1 physiology informs the pharmacotherapy of obesity.
Glucagon-like peptide-1 receptor agonists (GLP1RA) augment glucose-dependent insulin release and reduce glucagon secretion and gastric emptying, enabling their successful development for the treatment of type 2 diabetes (T2D). These agents also inhibit food intake and reduce body weight, fostering investigation of GLP1RA for the treatment of obesity.. Here I discuss the physiology of Glucagon-like peptide-1 (GLP-1) action in the control of food intake in animals and humans, highlighting the importance of gut vs. brain-derived GLP-1 for the control of feeding and body weight. The widespread distribution and function of multiple GLP-1 receptor (GLP1R) populations in the central and autonomic nervous system are outlined, and the importance of pathways controlling energy expenditure in preclinical studies vs. reduction of food intake in both animals and humans is highlighted. The relative contributions of vagal afferent pathways vs. GLP1R+ populations in the central nervous system for the physiological reduction of food intake and the anorectic response to GLP1RA are compared and reviewed. Key data enabling the development of two GLP1RA for obesity therapy (liraglutide 3 mg daily and semaglutide 2.4 mg once weekly) are discussed. Finally, emerging data potentially supporting the combination of GLP-1 with additional peptide epitopes in unimolecular multi-agonists, as well as in fixed-dose combination therapies, are highlighted.. The actions of GLP-1 to reduce food intake and body weight are highly conserved in obese animals and humans, in both adolescents and adults. The well-defined mechanisms of GLP-1 action through a single G protein-coupled receptor, together with the extensive safety database of GLP1RA in people with T2D, provide reassurance surrounding the long-term use of these agents in people with obesity and multiple co-morbidities. GLP1RA may also be effective in conditions associated with obesity, such as cardiovascular disease and non-alcoholic steatohepatitis (NASH). Progressive improvements in the efficacy of GLP1RA suggest that GLP-1-based therapies may soon rival bariatric surgery as viable options for the treatment of obesity and its complications. Topics: Adolescent; Animals; Diabetes Mellitus, Type 2; Glucagon-Like Peptide 1; Glucagon-Like Peptide-1 Receptor; Humans; Liraglutide; Obesity | 2022 |
Brain energy failure in dementia syndromes: Opportunities and challenges for glucagon-like peptide-1 receptor agonists.
Medications for type 2 diabetes (T2DM) offer a promising path for discovery and development of effective interventions for dementia syndromes. A common feature of dementia syndromes is an energy failure due to reduced energy supply to neurons and is associated with synaptic loss and results in cognitive decline and behavioral changes. Among diabetes medications, glucagon-like peptide-1 (GLP-1) receptor agonists (RAs) promote protective effects on vascular, microglial, and neuronal functions. In this review, we present evidence from animal models, imaging studies, and clinical trials that support developing GLP-1 RAs for dementia syndromes. The review examines how changes in brain energy metabolism differ in conditions of insulin resistance and T2DM from dementia and underscores the challenges that arise from the heterogeneity of dementia syndromes. The development of GLP-1 RAs as dementia therapies requires a deeper understanding of the regional changes in brain energy homeostasis guided by novel imaging biomarkers. Topics: Animals; Brain; Dementia; Diabetes Mellitus, Type 2; Glucagon-Like Peptide 1; Glucagon-Like Peptide-1 Receptor; Humans; Hypoglycemic Agents; Syndrome | 2022 |
Cardiovascular protective effects of GLP-1: a focus on the MAPK signaling pathway.
Cardiovascular and related metabolic diseases are significant global health challenges. Glucagon-like peptide 1 (GLP-1) is a brain-gut peptide secreted by the ileal endocrine system and is now an established drug target in type 2 diabetes (T2DM). GLP-1 targeting agents have been shown not only to treat T2DM, but also to exert cardiovascular protective effects by regulating multiple signaling pathways. The mitogen-activated protein kinase (MAPK) pathway, a common signal transduction pathway for transmitting extracellular signals to downstream effector molecules, is involved in regulating diverse cellular physiological processes, including cell proliferation, differentiation, stress, inflammation, functional synchronization, transformation, and apoptosis. The purpose of this review is to highlight the relationship between GLP-1 and cardiovascular disease (CVD) and discuss how GLP-1 exerts cardiovascular protective effects through the MAPK signaling pathway. This review also discusses the future challenges in fully characterizing and evaluating the CVD protective effects of GLP-1 receptor agonists (GLP-1RA) at the cellular and molecular levels. A better understanding of the MAPK signaling pathway that is dysregulated in CVD may aid in the design and development of promising GLP-1RA. Topics: Cardiovascular Diseases; Diabetes Mellitus, Type 2; Glucagon-Like Peptide 1; Glucagon-Like Peptide-1 Receptor; Humans; Mitogen-Activated Protein Kinases; Signal Transduction | 2022 |
Wegovy (semaglutide): a new weight loss drug for chronic weight management.
Obesity is a growing epidemic within the USA. Because weight gain is associated with an increased risk of developing life-threatening comorbidities, such as hypertension or type 2 diabetes, there is great interest in developing non-invasive pharmacotherapeutics to help combat obesity. Glucagon-like peptide-1 (GLP-1) receptor agonists are a class of antidiabetic medications that have shown promise in encouraging glycemic control and promoting weight loss in patients with or without type 2 diabetes. This literature review summarizes and discusses the weight loss results from the SUSTAIN (Semaglutide Unabated Sustainability in Treatment of Type 2 Diabetes), PIONEER (Peptide Innovation for Early Diabetes Treatment), and STEP (Semaglutide Treatment Effect in People with Obesity) clinical trial programs. The SUSTAIN and PIONEER clinical trials studied the use of 1.0 mg, once-weekly, subcutaneous and oral semaglutide (a new GLP-1 homolog), respectively, on participants with type 2 diabetes. The STEP trial examined the effects of 2.4 mg, once-weekly, subcutaneous semaglutide on patients with obesity. Trial data and other pertinent articles were obtained via database search through the US National Library of Medicine Clinical Trials and the National Center for Biotechnology Information. All three clinical trials demonstrated that semaglutide (injected or oral) has superior efficacy compared with placebo and other antidiabetic medications in weight reduction, which led to Food and Drug Administration approval of Wegovy (semaglutide) for weight loss. Topics: Anti-Obesity Agents; Diabetes Mellitus, Type 2; Glucagon-Like Peptide 1; Glucagon-Like Peptide-1 Receptor; Glucagon-Like Peptides; Glycated Hemoglobin; Humans; Hypoglycemic Agents; Injections, Subcutaneous; Obesity; Weight Loss | 2022 |
Amyloidogenicity of peptides targeting diabetes and obesity.
Since the discovery of insulin, a century ago, the repertoire of therapeutic polypeptides targeting diabetes - and now also obesity - have increased substantially. The focus on quality has shifted from impure and unstable preparations of animal insulin to highly pure, homologous recombinant insulin, along with other peptide-based hormones and analogs such as amylin analogs (pramlintide, davalintide, cagrilintide), glucagon and glucagon-like peptide-1 receptor agonists (GLP-1, liraglutide, exenatide, semaglutide). Proper formulation, storage, manipulation and usage by professionals and patients are required in order to avoid agglomeration into high molecular weight products (HMWP), either amorphous or amyloid, which could result in potential loss of biological activity and short- or long-term immune reaction and silent inactivation. In this narrative review, we present perspective of the aggregation of therapeutic polypeptides used in diabetes and other metabolic diseases, covering the nature and mechanisms, analytical techniques, physical and chemical stability, strategies aimed to hamper the formation of HMWP, and perspectives on future biopharmaceutical developments. Topics: Animals; Diabetes Mellitus, Type 2; Glucagon-Like Peptide 1; Glucagon-Like Peptide-1 Receptor; Humans; Hypoglycemic Agents; Islet Amyloid Polypeptide; Obesity | 2022 |
Will intestinal flora therapy become a new target in type-2 diabetes mellitus? A review based on 13 clinical trials.
Background: diabetes mellitus (DM) is a chronic disease and its pathogenesis is still inconclusive. Current evidence suggests an association between intestinal flora and type-2 diabetes mellitus (T2DM). In this paper, we summarized the current research, determining whether intestinal flora may become a new method to treat T2DM, and providing a theoretical basis and literature references for the prevention of T2DM based on the regulation of intestinal flora. Method: we carried out a review based on 13 published clinical trials to determine the correlation between T2DM and intestinal flora, and between changes in clinical outcomes and in intestinal flora in the development of T2DM; to assess the pathological mechanisms; and to discuss the treatment of diabetes based on intestinal flora. Results: we found that intestinal flora is involved in the occurrence and development of T2DM. Several pathological mechanisms may be involved in the process, including improving the gut barrier, alleviating inflammation, increasing glucagon-like peptide (GLP) 1 and GLP 2, increasing the production of short-chain fatty acids (SCFAs), and so on. Several measures based on intestinal flora, including exercise, food, specific diets, drugs and probiotics, would be used to treat and even prevent T2DM. Conclusions: high-quality studies are required to better understand the clinical effects of intestinal flora in T2DM.. Antecedentes: la diabetes mellitus (DM) es una enfermedad crónica cuya patogénesis no está clara. La evidencia actual sugiere una asociación entre la flora intestinal y la diabetes mellitus de tipo 2 (DMT2). Este artículo revisa la investigación actual para determinar si la flora intestinal puede ser un nuevo método de tratamiento de la DMT2. Métodos: se revisaron 13 ensayos clínicos publicados para determinar la correlación entre la DMT2 y la flora intestinal, cambios en los resultados clínicos y en la flora intestinal durante el desarrollo de la DMT2; para resumir su mecanismo patogénico; y, desde el punto de vista de la flora intestinal, para explorar el tratamiento de la diabetes. Resultados: se encontró que la flora intestinal estaba involucrada en el desarrollo de la DMT2. Este proceso puede implicar una variedad de mecanismos patológicos: mejora de la barrera intestinal, reducción de la inflamación, aumento del péptido similar al glucagón (GLP) 1 y GLP 2, y el del rendimiento de los ácidos grasos de cadena corta. Algunas medidas basadas en la flora intestinal, como el ejercicio, los alimentos, las dietas especiales, los medicamentos y los probióticos, se utilizarán para tratar e incluso prevenir la DMT2. Conclusión: se necesitan estudios de alta calidad para comprender mejor los efectos clínicos de la flora intestinal en los pacientes con DMT2. Topics: Clinical Trials as Topic; Diabetes Mellitus, Type 2; Fatty Acids, Volatile; Gastrointestinal Microbiome; Glucagon-Like Peptide 1; Humans; Probiotics | 2022 |
Updated network meta-analysis assessing the relative efficacy of 13 GLP-1 RA and SGLT2 inhibitor interventions on cardiorenal and mortality outcomes in type 2 diabetes.
Topics: Diabetes Mellitus, Type 2; Glucagon-Like Peptide 1; Glucagon-Like Peptide-1 Receptor; Humans; Hypoglycemic Agents; Network Meta-Analysis; Sodium-Glucose Transporter 2 Inhibitors | 2022 |
The current significance and prospects for the use of dual receptor agonism GLP-1/Glucagon.
The therapeutic arsenal for treating type 2 diabetes mellitus (T2DM) has been enriched recently with the inclusion of type 1 glucagon-like peptide (GLP-1). GLP-1 receptor agonists (RA) secondarily reduce appetite, decrease gastric emptying, and reduce body weight. This effect has been used to treat overweight/obesity, especially with comorbidities associated with T2DM. However, the first formulations and adverse effects gradually gave way to new formulations with fewer unpleasant effects and a more extended period of action (weekly subcutaneous administration and even oral administration), which improved the acceptance and adherence to the treatment. Therefore, titration of GLP-1RA should be done gradually. Furthermore, when side effects are consistent and intolerable after weeks/months of titration, a lower dose or a combination of antidiabetic therapies should be implemented, avoiding treatment interruption. The effort to produce increasingly powerful molecules with fewer side effects is the driving force behind the pharmaceutical industry. The unimolecular dual agonism GLP-1RA plus glucagon receptor agonism (GRA) represents an updated pharmacological indication for controlling blood glucose levels in treating T2DM and its comorbidities, showing better effects with less adverse impact than mono GLP-1RA. There are currently different proposals in this way by different laboratories. Nevertheless, the experimental results are promising and show that soon, we will have the contribution of new drugs for the treatment of T2DM. Topics: Animals; Diabetes Mellitus, Type 2; Glucagon; Glucagon-Like Peptide 1; Glucagon-Like Peptide-1 Receptor; Humans; Hypoglycemic Agents; Incretins; Obesity | 2022 |
Dual-agonist incretin peptides from fish with potential for obesity-related Type 2 diabetes therapy - A review.
The long-acting glucagon-like peptide-1 receptor (GLP1R) agonist, semaglutide and the unimolecular glucose-dependent insulinotropic polypeptide receptor (GIPR)/GLP1R dual-agonist, tirzepatide have been successfully introduced as therapeutic options for patients with Type-2 diabetes (T2DM) and obesity. Proglucagon-derived peptides from phylogenetically ancient fish act as naturally occurring dual agonists at the GLP1R and the glucagon receptor (GCGR) with lamprey GLP-1 and paddlefish glucagon being the most potent and effective in stimulating insulin release from BRIN-BD11 clonal β-cells. These peptides were also the most effective in lowering blood glucose and elevating plasma insulin concentrations when administered intraperitoneally to overnight-fasted mice together with a glucose load. Zebrafish GIP acts as a dual agonist at the GIPR and GLP1R receptors. Studies with the high fat-fed mouse, an animal model with obesity, impaired glucose-tolerance and insulin-resistance, have shown that twice-daily administration of the long-acting analogs [D-Ala Topics: Animals; Anti-Obesity Agents; Diabetes Mellitus, Type 2; Eating; Fish Proteins; Glucagon-Like Peptide 1; Glucagon-Like Peptide-1 Receptor; Glucose; Humans; Hypoglycemic Agents; Incretins; Insulin Resistance; Obesity; Proglucagon | 2022 |
Effect of SGLT2 inhibitors versus DPP4 inhibitors or GLP-1 agonists on diabetic foot-related extremity amputation in patients with T2DM: A meta-analysis.
To compare the contribution of sodium-glucose cotransporter-2 inhibitors (SGLT2is) with that of DPP4i or GLP-1ra toward lower extremity amputation rate.. Electronic databases were searched for articles published on the differences between the rates of lower extremity amputation among patients with type 2 diabetes mellitus (T2DM) undergoing SGLT2i treatment and those undergoing other anti-hyperglycemic agent (dipeptidyl peptidase-4 inhibitors [DPP4is], glucagon-like peptide-1 receptor agonist [GLP-1as], or sulfonylurea [SUs]) treatments. Random-effect models were used to generate data if heterogeneity was detected.. Eight studies based on retrospective case-control designs with propensity matching were included. The propensity score-matching method increased credibility. Compared with SGLT2i treatment, DPP4i or GLP-1a treatment tended to result in a higher amputation rate (pooled hazard ratio [HR] = 1.1, 95% confidence interval [CI]: 0.98-1.23), whereas SU treatment resulted in similar amputation rates (pooled HR = 0.92, 95% CI: 0.74-1.13). After excluding the heterogeneous study, the meta-analysis of the remaining studies attained a statistical value (pooled HR = 0.81, 95% CI: 0.65-1.01).. The study findings suggest that, with respect to diabetic foot-related limb amputations, SGLT2is are not superior to novel anti-hyperglycemic agents (DPP4is and GLP-1as) or other types of oral hypoglycemic agents (SUs). Therefore, SGLT2is may not have significantly positive effects on the prognosis for T2DM patients with complicated diabetic foot. Topics: Amputation, Surgical; Diabetes Mellitus, Type 2; Diabetic Foot; Dipeptidyl Peptidase 4; Dipeptidyl-Peptidase IV Inhibitors; Extremities; Glucagon-Like Peptide 1; Glucagon-Like Peptide-1 Receptor; Humans; Hypoglycemic Agents; Retrospective Studies; Sodium-Glucose Transporter 2 Inhibitors | 2022 |
GLP-1 mimetics as a potential therapy for nonalcoholic steatohepatitis.
Nonalcoholic steatohepatitis (NASH), as a severe form of nonalcoholic fatty liver disease (NAFLD), is characterized by liver steatosis, inflammation, hepatocellular injury and different degrees of fibrosis. The pathogenesis of NASH is complex and multifactorial, obesity and type 2 diabetes mellitus (T2DM) have been implicated as major risk factors. Glucagon-like peptide-1 receptor (GLP-1R) is one of the most successful drug targets of T2DM and obesity, and its peptidic ligands have been proposed as potential therapeutic agents for NASH. In this article we provide an overview of the pathophysiology and management of NASH, with a special focus on the pharmacological effects and possible mechanisms of GLP-1 mimetics in treating NAFLD/NASH, including dual and triple agonists at GLP-1R, glucose-dependent insulinotropic polypeptide receptor or glucagon receptor. Topics: Diabetes Mellitus, Type 2; Glucagon-Like Peptide 1; Glucagon-Like Peptide-1 Receptor; Humans; Hypoglycemic Agents; Non-alcoholic Fatty Liver Disease; Obesity | 2022 |
Cardiorenal benefits of glucagon-like peptide-1 analogues vs. exendin-4 analogues in patients with type 2 diabetes: a meta-analysis based on cardiovascular outcome trials.
Topics: Diabetes Mellitus, Type 2; Exenatide; Glucagon-Like Peptide 1; Glucagon-Like Peptide-1 Receptor; Humans; Hypoglycemic Agents | 2022 |
Cardiovascular effectiveness of glucagon-like peptide 1 receptor agonists versus dipeptidyl peptidase-4 inhibitors in type 2 diabetes: A meta-analysis based on propensity score-matched studies.
Glucagon-like peptide 1 receptor agonists (GLP-1RA) and dipeptidyl peptidase-4 inhibitors (DPP-4i) are two novel classes of hypoglycemic agents. The relative cardiovascular effectiveness between these two drug classes in patients with type 2 diabetes (T2D) is unestablished due to the absence of large cardiovascular outcome trials directly comparing DPP-4i with GLP-1RA. We aimed to incorporate large propensity score-matched cohort studies to conduct a meta-analysis, to determine the relative effectiveness of GLP-1RA versus DPP-4i on cardiovascular endpoints in T2D patients. Compared to DPP-4i, GLP-1RA was associated with the significantly lower risks of major adverse cardiovascular events [MACE] (HR 0.76, 95% CI 0.63-0.92), cardiovascular mortality (HR 0.59, 95% CI 0.37-0.95), myocardial infarction (HR 0.89, 95% CI 0.80-0.98), stroke (HR 0.86, 95% CI 0.76-0.96), and all-cause mortality (HR 0.63, 95% CI 0.42-0.96) in T2D patients; whereas these two drug classes had the similar risk of hospitalization for heart failure [HHF] (HR 0.95, 95% CI 0.77-1.16). Meta-regression analyses showed that six factors (i.e., mean age, female proportion, cardiovascular disease proportion, heart failure proportion, and the proportions of receiving metformin and insulin at baseline) did not significantly affect the effects of GLP-1RA on MACE and HHF (P ≥ 0.076). This meta-analysis provides the direct evidence regarding the relative cardiovascular effectiveness of GLP-1RA versus DPP-4i from real-world studies, and its findings suggest that among T2D patients GLP-1RA should be considered in preference to DPP-4i as for preventing atherosclerotic cardiovascular events and death in clinical practice. Topics: Cardiovascular Diseases; Diabetes Mellitus, Type 2; Dipeptidyl-Peptidase IV Inhibitors; Dipeptidyl-Peptidases and Tripeptidyl-Peptidases; Female; Glucagon-Like Peptide 1; Glucagon-Like Peptide-1 Receptor; Humans; Hypoglycemic Agents; Propensity Score | 2022 |
Glucagon-Like Peptide-1 Receptor Agonists in Type 2 Diabetes Mellitus and Cardiovascular Disease: The Past, Present, and Future.
Type 2 diabetes mellitus (T2DM) is associated with high cardiovascular morbidity and mortality, and cardiovascular diseases are the leading causes of death and disability in people with T2DM. Unfortunately, therapies strictly aimed at glycemic control have poorly contributed to a significant reduction in the risk of cardiovascular events. On the other hand, randomized controlled trials have shown that five glucagon-like peptide-1 receptor agonists (GLP-1 RAs) and one exendin-based GLP-1 RA reduced atherosclerotic cardiovascular events in patients with diabetes at high cardiovascular risk. Furthermore, a meta-analysis including these six agents showed a reduction in major adverse cardiovascular events as well as all-cause mortality compared with placebo, regardless of structural homology. Evidence has also shown that some drugs in this class have beneficial effects on renal outcomes, such as preventing the onset of macroalbuminuria. In addition to lowering blood pressure, these drugs also favorably impacted on body weight in large randomized controlled trials as in real-world studies, a result considered a priority in T2DM management; these and other factors may justify the benefits of GLP-1 RAs upon the cardiovascular system, regardless of glycemic control. Finally, studies showed safety with a low risk of hypoglycemia and no increase in pancreatitis events. Given these benefits, GLP-1 RAs were preferentially endorsed in the guidelines of the European and American societies for patients with these conditions. This narrative review provides a current and comprehensive overview of GLP-1 RAs as cardiovascular and renal protective agents, far beyond their use as glucose-lowering drugs, supporting their effectiveness in treating patients with T2DM at high cardiovascular risk. Topics: Cardiovascular Diseases; Diabetes Mellitus, Type 2; Glucagon-Like Peptide 1; Glucagon-Like Peptide-1 Receptor; Humans; Hypoglycemic Agents | 2022 |
Glucagon-like peptide-1: Are its roles as endogenous hormone and therapeutic wizard congruent?
Glucagon-like peptide-1 (GLP-1) is a peptide derived from differential processing of the precursor for the hormone glucagon. It is secreted predominantly by endocrine cells in the gut epithelium in response to nutrient stimulation. Studies from the last 35 years have given us an idea about its physiological functions. On the basis of some of its many actions, it has also been developed into a pharmaceutical agent for the treatment of obesity and type 2 diabetes (T2DM). It is currently positioned as the most effective anti-obesity agent available and is recommended in both national and international guidelines as an effective second-in line treatment for T2DM, in particular in patients with increased cardiovascular risk. In this review, I first discuss whether the processing of proglucagon may also result in GLP-1 formation in the pancreas and in glucagon in the gut. Next, I discuss the relationship between the physiological actions of GLP-1 and the therapeutic effects of the GLP-1 receptor agonists, which are far from being congruent and generally poorly understood. These relationships illustrate both the difficulties and the benefits of bridging results obtained in the laboratory with those emerging from the clinic. Topics: Diabetes Mellitus, Type 2; Glucagon; Glucagon-Like Peptide 1; Glucagon-Like Peptide-1 Receptor; Humans | 2022 |
Efficacy and safety of high-dose glucagon-like peptide-1, glucagon-like peptide-1/glucose-dependent insulinotropic peptide, and glucagon-like peptide-1/glucagon receptor agonists in type 2 diabetes.
Glucagon-like peptide-1 receptor agonists (GLP-1 RAs) have become agents of choice for people with type 2 diabetes (T2D) with established cardiovascular disease or in high-risk individuals. With currently available GLP-1 RAs, 51%-79% of subjects achieve an HbA1c target of less than 7.0% and 4%-27% lose 10% of body weight, illustrating the need for more potent agents. Three databases (PubMed, Cochrane, Web of Science) were searched using the MESH terms 'glucagon-like peptide-1 receptor agonist', 'glucagon receptor agonist', 'glucose-dependent insulinotropic peptide', 'dual or co-agonist', and 'tirzepatide'. Quality of papers was scored using PRISMA guidelines. Risk of bias was evaluated using the Cochrane assessment tool. An HbA1c target of less than 7.0% was attained by up to 80% with high-dose GLP-1 RAs and up to 97% with tirzepatide, with even up to 62% of people with T2D reaching an HbA1c of less than 5.7%. A body weight loss of 10% or greater was obtained by up to 50% and up to 69% with high-dose GLP-1 RAs or tirzepatide, respectively. The glucose- and weight-lowering effects of the GLP-1/glucagon RA cotadutide equal those of liraglutide 1.8 mg. Gastrointestinal side effects of high-dose GLP-1 RAs and co-agonists occurred in 30%-70% of patients, mostly arising within the first 2 weeks of the first dose, being mild or moderate in severity, and transient. The development of high-dose GLP-1 RAs and the dual GLP-1/glucose-dependent insulinotropic peptide RA tirzepatide resulted in increasing numbers of people reaching HbA1c and body weight targets, with up to 62% attaining normoglycaemia with 15-mg tirzepatide. Whether this will also translate to better cardiovascular outcomes and affect treatment guidelines remains to be studied. Topics: Blood Glucose; Diabetes Mellitus, Type 2; Gastric Inhibitory Polypeptide; Glucagon-Like Peptide 1; Glucagon-Like Peptide-1 Receptor; Humans; Hypoglycemic Agents; Receptors, Glucagon | 2022 |
Semaglutide, a glucagon like peptide-1 receptor agonist with cardiovascular benefits for management of type 2 diabetes.
Semaglutide, a glucagon like peptide-1 (GLP-1) receptor agonist, is available as monotherapy in both subcutaneous as well as oral dosage form (first approved oral GLP-1 receptor agonist). It has been approved as a second line treatment option for better glycaemic control in type 2 diabetes and currently under scrutiny for anti-obesity purpose. Semaglutide has been proved to be safe in adults and elderly patients with renal or hepatic disorders demanding no dose modification. Cardiovascular (CV) outcome trials established that it can reduce various CV risk factors in patients with established CV disorders. Semaglutide is well tolerated with no risk of hypoglycaemia in monotherapy but suffers from gastrointestinal adverse effects. A large population affected with COVID-19 infection were diabetic; therefore use of semaglutide in diabetes as well as CV patients would be very much supportive in maintaining health care system during this pandemic situation. Hence, this peptidic drug can be truly considered as a quintessential of GLP-1 agonists for management of type 2 diabetes. Topics: Aged; COVID-19 Drug Treatment; Diabetes Mellitus, Type 2; Glucagon-Like Peptide 1; Glucagon-Like Peptide-1 Receptor; Glucagon-Like Peptides; Humans; Hypoglycemic Agents | 2022 |
Role and mechanism(s) of incretin-dependent therapies for treating diabetes mellitus.
Diabetes mellitus (DM) is a worldwide ailment which leads to chronic complications like cardiac disorders, renal perturbations, limb amputation and blindness. Type one diabetes (T1DM), Type two diabetes (T2DM), Another types of diabetes, such as genetic errors in function of β-cell and action of insulin, cystic fibrosis, chemical-instigated diabetes or following tissue transplantation), and pregnancy DM (GDM). In response to nutritional ingestion, the gut may release a pancreatic stimulant that affects carbohydrate metabolism. The duodenum produces a 'chemical excitant' that stimulates pancreatic output, and researchers have sought to cure diabetes using gut extract injections, coining the word 'incretin' to describe the phenomena. Incretins include GIP and GLP-1. The 'enteroinsular axis' is the link between pancreas and intestine. Nutrient, neuronal and hormonal impulses from intestine to cells secreting insulin were thought to be part of this axis. In addition, the hormonal component, incretin, must meet two requirements: (1) it secreted by foods, mainly carbohydrates, and (2) it must induce an insulinotropic effect which is glucose-dependent. In this review, we clarify the ability of using incretin-dependent treatments for treating DM. Topics: Diabetes Mellitus, Type 2; Gastric Inhibitory Polypeptide; Glucagon-Like Peptide 1; Humans; Incretins; Insulin-Secreting Cells | 2022 |
GLP-1a: Going beyond Traditional Use.
Glucagon-like peptide-1 (GLP-1) is a human incretin hormone derived from the proglucagon molecule. GLP-1 receptor agonists are frequently used to treat type 2 diabetes mellitus and obesity. However, the hormone affects the liver, pancreas, brain, fat cells, heart, and gastrointestinal tract. The objective of this study was to perform a systematic review on the use of GLP-1 other than in treating diabetes. PubMed, Cochrane, and Embase were searched, and the PRISMA guidelines were followed. Nineteen clinical studies were selected. The results showed that GLP-1 agonists can benefit defined off-medication motor scores in Parkinson's Disease and improve emotional well-being. In Alzheimer's disease, GLP-1 analogs can improve the brain's glucose metabolism by improving glucose transport across the blood-brain barrier. In depression, the analogs can improve quality of life and depression scales. GLP-1 analogs can also have a role in treating chemical dependency, inhibiting dopaminergic release in the brain's reward centers, decreasing withdrawal effects and relapses. These medications can also improve lipotoxicity by reducing visceral adiposity and decreasing liver fat deposition, reducing insulin resistance and the development of non-alcoholic fatty liver diseases. The adverse effects are primarily gastrointestinal. Therefore, GLP-1 analogs can benefit other conditions besides traditional diabetes and obesity uses. Topics: Clinical Trials as Topic; Diabetes Mellitus, Type 2; Disease Management; Glucagon-Like Peptide 1; Glucagon-Like Peptide-1 Receptor; Humans; Neurodegenerative Diseases; Obesity; Peptide Fragments; Treatment Outcome | 2022 |
GLP-1 and GIP receptor signaling in beta cells - A review of receptor interactions and co-stimulation.
Glucagon-like peptide 1 receptor (GLP-1R) and glucose-dependent insulinotropic polypeptide receptor (GIPR) are two class B1 G protein-coupled receptors, which are stimulated by the gastrointestinal hormones GLP-1 and GIP, respectively. In the pancreatic beta cells, activation of both receptors lead to increased cyclic adenosine monophosphate (cAMP) and glucose-dependent insulin secretion. Marketed GLP-1R agonists such as dulaglutide, liraglutide, exenatide and semaglutide constitute an expanding drug class with beneficial effects for persons suffering from type 2 diabetes and/or obesity. In recent years another drug class, the GLP-1R-GIPR co-agonists, has emerged. Especially the peptide-based, co-agonist tirzepatide is a promising candidate for a better treatment of type 2 diabetes by improving glycemic control and weight reduction. The mechanism of action for tirzepatide include biased signaling of the GLP-1R as well as potent GIPR signaling. Since the implications of co-targeting these closely related receptors concomitantly are challenging to study in vivo, the pharmacodynamic mechanisms and downstream signaling pathways of the GLP-1R-GIPR co-agonists in general, are not fully elucidated. In this review, we present the individual signaling pathways for GLP-1R and GIPR in the pancreatic beta cell with a focus on the shared signaling pathways of the two receptors and interpret the implications of GLP-1R-GIPR co-activation in the light of recent co-activating therapeutic compounds. Topics: Diabetes Mellitus, Type 2; Gastric Inhibitory Polypeptide; Glucagon-Like Peptide 1; Glucagon-Like Peptide-1 Receptor; Humans; Insulin-Secreting Cells; Receptors, Gastrointestinal Hormone | 2022 |
The Effect of GLP-1 Receptor Agonists on Postprandial Lipaemia.
To review the currently available data on the effect of Glucagon-like peptide 1 receptor agonists (GLP-1 RAs) on postprandial lipaemia. Topics: Apolipoprotein B-48; Apolipoprotein C-III; Chylomicrons; Diabetes Mellitus, Type 2; Exenatide; Glucagon-Like Peptide 1; Glucagon-Like Peptide-1 Receptor; Humans; Hyperlipidemias; Hypoglycemic Agents; Liraglutide | 2022 |
Effects of glucagon-like peptide-1 receptor agonists on cardiovascular and renal outcomes: A meta-analysis and meta-regression analysis.
To evaluate the cardiovascular and renal outcomes of glucagon-like peptide-1 receptor agonists (GLP-1 RAs) and the associations between these outcomes and HbA1c or weight reduction.. We searched PubMed/MEDLINE, EMBASE, and CENTRAL databases for randomized, placebo-controlled trials of GLP-1 RAs reporting major adverse cardiovascular events (MACE; a composite of cardiovascular mortality, stroke, and myocardial infarction) as the primary outcome. We conducted a meta-regression analysis of primary and secondary outcomes with HbA1c or weight reduction following a meta-analysis with a random-effects model for these outcomes.. The reduction in HbA1c, but not body weight, is associated with cardiovascular and renal outcomes. The magnitude of HbA1c reduction can be a surrogate for the cardiovascular and renal benefits of treatment with GLP-1 RAs. Topics: Cardiovascular Diseases; Diabetes Mellitus, Type 2; Glucagon-Like Peptide 1; Glucagon-Like Peptide-1 Receptor; Glycated Hemoglobin; Humans; Hypoglycemic Agents; Regression Analysis; Weight Loss | 2022 |
Effect of glucagon-like peptide-1 receptor agonists on body weight in adults with obesity without diabetes mellitus-a systematic review and meta-analysis of randomized control trials.
Clinical trials have investigated the weight loss effect of glucagon-like peptide-1 receptor agonists (GLP-1 RA) in adults with obesity without diabetes mellitus, but results for weight loss efficacy were varied. We aimed to provide an up-to-date systematic review and meta-analysis for overall weight loss effect of GLP-1 RA in adults with obesity and overweight without diabetes mellitus. We retrieved eligible randomized control trials that assessed the weight loss effect of GLP-1 RA in adults (≥18 years old) without type 1/type 2 diabetes up to September 30, 2021, using Pubmed and Embase. Of 36 clinical trials assessed for eligibility, 12 trials were included, with a combined total of 11,459 participants. Compared with control groups, a more significant weight loss was seen in GLP-1 RA groups with an overall mean difference of -7.1 kg (95% CI -9.2 to -5.0) (I Topics: Adolescent; Adult; Diabetes Mellitus, Type 2; Glucagon-Like Peptide 1; Glucagon-Like Peptide-1 Receptor; Humans; Hypoglycemic Agents; Obesity; Weight Loss | 2022 |
Contemporary Medical Therapies for Patients with Peripheral Artery Disease and Concomitant Type 2 Diabetes Mellitus: a Review of Current Evidence.
The purpose of this review is to highlight the evidence behind landmark trials involving these two novel drug classes in conjunction with a review of long-standing therapies used to improve cardiovascular (CV) outcomes among patients with peripheral artery disease (PAD) patients and type 2 diabetes mellitus (T2DM).. Recently, societal guideline recommendations have expanded the management of T2DM to incorporate therapies with CV risk factor modification. This is due to CV outcome trials (CVOT) uncovering advantageous cardioprotective effects of several novel therapies, including glucagon-like peptide-1 receptor agonists (GLP-1 RA) and sodium-glucose cotransporter-2 inhibitors (SGLT2i). Providers who manage high-risk patients with T2DM, such as those with concomitant PAD, are expected to incorporate these novel medical therapies into routine patient care. The body of evidence surrounding GLP-1 RA demonstrates a strong benefit in mitigating the innate heightened CV risk among patients with T2DM. Furthermore, SGLT2i not only have a favorable CV profile but also reduce the risk of HF hospitalizations and progression of renal disease. Patients with T2DM and PAD are known to be at a heightened risk for major adverse cardiac and lower extremity events, heart failure, and chronic kidney disease. As such, the use of novel therapies such as GLP-RA and SGLT2i should be strongly considered to minimize morbidity and mortality in this vulnerable population. Topics: Cardiovascular Diseases; Diabetes Mellitus, Type 2; Glucagon-Like Peptide 1; Glucagon-Like Peptide-1 Receptor; Humans; Hypoglycemic Agents; Peripheral Arterial Disease; Sodium-Glucose Transporter 2 Inhibitors | 2022 |
Efficacy of a meal sequence in patients with type 2 diabetes: a systematic review and meta-analysis.
This systematic review investigated the efficacy of a meal sequence, the carbohydrate-later meal pattern (CL), on type 2 diabetes mellitus (T2DM).. We searched the Cochrane Central Register of Controlled Trials, MEDLINE, Embase, WHO International Clinical Trials Registry Platform, and ClinicalTrials.gov until April 2020 to perform meta-analyses using random-effects models. Primary outcomes were hemoglobin A1c (HbA1c) and quality of life. Secondary outcomes were plasma concentrations of glucose, insulin and incretin 120 min after a meal, and any adverse outcomes. The revised Cochrane risk-of-bias tool and Grading of Recommendations, Assessment, Development, and Evaluation approach were used to assess the quality of individual studies and the body of evidence, respectively. The present study was registered in the UMIN Clinical Trials Registry.. We included 230 participants in eight trials, including both trials that examined long-term changes (more than 2 months and less than 2 years) and short-term changes (in 2-hour postprandial values). CL resulted in a slight to no difference in HbA1c (mean difference (MD), -0.21% in the intervention group; 95% CI -0.44% to+0.03%), plasma glucose (MD,+4.94 mg/dL; 95% CI -8.34 mg/dL to +18.22 mg/dL), plasma insulin (MD, -3.63 μIU/mL; 95% CI -11.88 μIU/mL to +4.61 μIU/mL), plasma GLP-1 (MD, +0.43 pmol/L; 95% CI -0.69 pmol/L to +1.56 pmol/L), and plasma GIP (MD, -2.02 pmol/L; 95% CI -12.34 pmol/L to +8.31 pmol/L). All of these outcomes were of low-certainty evidence or very low-certainty evidence. None of the trials evaluated quality of life or adverse events.. There was no evidence for the potential efficacy of recommending CL beyond standard dietary advice on T2DM.. UMIN000039979. Topics: Diabetes Mellitus, Type 2; Glucagon-Like Peptide 1; Glycated Hemoglobin; Humans; Incretins; Quality of Life | 2022 |
Adverse drug reactions of GLP-1 agonists: A systematic review of case reports.
The importance of glucagon-like peptide-1 (GLP-1) agonists is increasing because of its blood sugar controlling and weight loss properties. The data regarding safety of GLP-1 agonists are limited. This study aims to review case reports and case series on adverse drug reactions (ADRs) of GLP-1 agonist.. A comprehensive search was performed in PubMed/Medline, Scopus and Embase to identify literatures. Bibliographic search and open search in Google, Google Scholar, SpringerLink and ResearchGate was performed to identify additional studies. Case reports and case series published the ADRs by the use of GLP-1 agonists in type 2 diabetes patients were included in the study. Reviews, experimental studies, observational studies, grey literature and non English studies were excluded.. The study identified 120 cases of GLP-1 agonists associated ADRs (liraglutide - 46, exenatide - 46, dulaglutide - 20, semaglutide - 4, albiglutide - 2, lixisenatide - 2). The major ADRs reported was gastrointestinal disorders (n = 40) followed by renal (n = 23), dermatologic (n = 14), hepatic (n = 10), immunologic (n = 13), endocrine/metabolic (n = 7), hematologic (n = 3), angioedema (n = 3), neurologic (n = 2), cardiovascular (n = 2) and 1 from each of psychiatric, reproductive, generalized edema problems.. Gastrointestinal problems, particularly pancreatitis was the more frequently reported adverse drug reaction associated with GLP-1 agonist. The most adverse drug reactions were observed with liraglutide and exenatide. Topics: Diabetes Mellitus, Type 2; Drug-Related Side Effects and Adverse Reactions; Glucagon-Like Peptide 1; Glucagon-Like Peptide-1 Receptor; Humans; Hypoglycemic Agents; Liraglutide | 2022 |
GLP-1 - Incretin and pleiotropic hormone with pharmacotherapy potential. Increasing secretion of endogenous GLP-1 for diabetes and obesity therapy.
Because of the beneficial actions of the hormone glucagon-like peptide-1 on glucose metabolism and appetite, food intake and eventually body weight, and because of the observation that the similar metabolic effects of gastric bypass surgery are associated with excessive secretion of GLP-1, attempts are now being made to stimulate the endogenous secretion of this hormone. By targeting the natural cellular origin of GLP-1 it is anticipated that also the physiological pathways of hormone action (which may include neural mechanisms) would be engaged, which might generate fewer side effects. In addition, release of other products of the responsible intestinal endocrine cells, the L-cells, namely the appetite inhibitory hormone, PYY 3-36, and the dual glucagon-GLP-1 co-agonist, oxyntomodulin, would also be promoted. Here, the normal mechanisms for stimulation of L-cell secretion are reviewed, and the potential of identified secretagogues is discussed. Paracrine regulation of L-cell secretion is also discussed and the potential of somatostatin receptor antagonists is emphasized. A therapeutic approach based on stimulation of endogenous secretion of GLP-1/PYY still seems both attractive and potentially feasible. Topics: Animals; Body Weight; Diabetes Mellitus; Diabetes Mellitus, Type 2; Glucagon-Like Peptide 1; Glucagon-Like Peptide-1 Receptor; Humans; Incretins; Obesity | 2022 |
Benefits of GLP-1 (Glucagon-Like Peptide 1) Receptor Agonists for Stroke Reduction in Type 2 Diabetes: A Call to Action for Neurologists.
People living with diabetes are at higher risk for stroke and have a poorer prognosis following a stroke event than those without diabetes. Data from cardiovascular outcome trials and meta-analyses indicate that GLP-1RAs (glucagon-like peptide 1 receptor agonists) reduce the risk of stroke in individuals with type 2 diabetes. Accordingly, many guidelines now recommend the addition of GLP-1RAs to ongoing antihyperglycemic regimens to lower the risk of stroke in type 2 diabetes. The current work summarizes evidence supporting the use of GLP-1RAs for stroke reduction in people with type 2 diabetes and offers 2 new resources for neurologists who are considering GLP-1RAs for their patients-a list of frequently asked questions with evidence-based answers on safely initiating and managing GLP-1RAs, and a practical decision-making algorithm to assist in using GLP-1RAs as part of a stroke reduction strategy. Topics: Diabetes Mellitus, Type 2; Glucagon-Like Peptide 1; Glucagon-Like Peptide-1 Receptor; Humans; Neurologists; Stroke | 2022 |
The effect of DPP-4 inhibitors, GLP-1 receptor agonists and SGLT-2 inhibitors on cardiorenal outcomes: a network meta-analysis of 23 CVOTs.
Glucagon-like peptide-1 receptor agonists (GLP-1RA) and sodium glucose co-transporter-2 (SGLT-2) inhibitors reduce cardiorenal outcomes. We performed a network meta-analysis to compare the effect on cardiorenal outcomes among GLP-1 RAs, SGLT-2 inhibitors and dipeptidyl peptidase-4 (DPP-4) inhibitors.. We searched the PUBMED, Embase and Cochrane databases for relevant studies published up until 10 December 2021. Cardiovascular and renal outcome trials reporting outcomes on GLP-1RA, SGLT-2 inhibitors and DPP-4 inhibitors in patients with or without type 2 diabetes mellitus were included. The primary outcome was major adverse cardiovascular events (MACE); other outcomes were cardiovascular and total death, nonfatal myocardial infarction (MI), nonfatal stroke, hospitalization for heart failure (HHF), and renal outcome.. Twenty-three trials enrolling a total number of 181,143 participants were included. DPP-4 inhibitors did not lower the risk of any cardiorenal outcome when compared with placebo and were associated with higher risks of MACE, HHF, and renal outcome when compared with the other two drug classes. SGLT-2 inhibitors significantly reduced cardiovascular (RR = 0.88) and total (RR = 0.87) death, as compared with DPP-4 inhibitors, while GLP-1 RA reduced total death only (RR = 0.87). The comparison between GLP-1RA and SGLT-2 inhibitors showed no difference in their risks of MACE, nonfatal MI, nonfatal stroke, CV and total death; SGLT-2 inhibitors were superior to GLP-1RA in reducing the risk of HHF and the renal outcome (24% and 22% lower risk, respectively). Only GLP-1RA reduced the risk of nonfatal stroke (RR = 0.84), as compared with placebo. There was no head-to-head trial directly comparing these antidiabetic drug classes.. SGLT-2 inhibitors and GLP-1RA are superior to DPP-4 inhibitors in reducing the risk of most cardiorenal outcomes; SGLT-2 inhibitors are superior to GLP-1RA in reducing the risk of HHF and renal events; GLP-1RA only reduced the risk of nonfatal stroke. Both SGLT-2 inhibitors and GLP-1RA should be the preferred treatment for type 2 diabetes and cardiorenal diseases. Topics: Cardiovascular Diseases; Diabetes Mellitus, Type 2; Dipeptidyl-Peptidase IV Inhibitors; Glucagon-Like Peptide 1; Glucagon-Like Peptide-1 Receptor; Heart Failure; Humans; Hypoglycemic Agents; Myocardial Infarction; Network Meta-Analysis; Sodium-Glucose Transporter 2 Inhibitors; Stroke | 2022 |
Recent Advances in Incretin-Based Pharmacotherapies for the Treatment of Obesity and Diabetes.
The incretin hormone glucagon-like peptide-1 (GLP-1) has received enormous attention during the past three decades as a therapeutic target for the treatment of obesity and type 2 diabetes. Continuous improvement of the pharmacokinetic profile of GLP-1R agonists, starting from native hormone with a half-life of ~2-3 min to the development of twice daily, daily and even once-weekly drugs highlight the pharmaceutical evolution of GLP-1-based medicines. In contrast to GLP-1, the incretin hormone glucose-dependent insulinotropic polypeptide (GIP) received little attention as a pharmacological target, because of conflicting observations that argue activation or inhibition of the GIP receptor (GIPR) provides beneficial effects on systemic metabolism. Interest in GIPR agonism for the treatment of obesity and diabetes was recently propelled by the clinical success of unimolecular dual-agonists targeting the receptors for GIP and GLP-1, with reported significantly improved body weight and glucose control in patients with obesity and type II diabetes. Here we review the biology and pharmacology of GLP-1 and GIP and discuss recent advances in incretin-based pharmacotherapies. Topics: Diabetes Mellitus, Type 2; Gastric Inhibitory Polypeptide; Glucagon-Like Peptide 1; Glucagon-Like Peptide-1 Receptor; Humans; Incretins; Obesity | 2022 |
The Role of Glucagon-Like Peptide-1 Receptor Agonists (GLP-1 RA) in Diabetes-Related Neurodegenerative Diseases.
Recent clinical guidelines have emphasized the importance of screening for cognitive impairment in older adults with diabetes, however, there is still a lack of understanding about the drug therapy. Glucagon-like peptide 1 receptor agonists (GLP-1 RAs) are widely used in the treatment of type 2 diabetes and potential applications may include the treatment of obesity as well as the adjunctive treatment of type 1 diabetes mellitus in combination with insulin. Growing evidence suggests that GLP-1 RA has the potential to treat neurodegenerative diseases, particularly in diabetes-related Alzheimer's disease (AD) and Parkinson's disease (PD). Here, we review the molecular mechanisms of the neuroprotective effects of GLP-1 RA in diabetes-related degenerative diseases, including AD and PD, and their potential effects. Topics: Aged; Diabetes Mellitus, Type 2; Glucagon-Like Peptide 1; Glucagon-Like Peptide-1 Receptor; Humans; Insulin; Neurodegenerative Diseases | 2022 |
Association of Glucagon-Like Peptide-1 Receptor Agonist Use With Risk of Gallbladder and Biliary Diseases: A Systematic Review and Meta-analysis of Randomized Clinical Trials.
Glucagon-like peptide-1 receptor agonists (GLP-1 RAs) have been widely recommended for glucose control and cardiovascular risk reduction in patients with type 2 diabetes, and more recently, for weight loss. However, the associations of GLP-1 RAs with gallbladder or biliary diseases are controversial.. To evaluate the association of GLP-1 RA treatment with gallbladder and biliary diseases and to explore risk factors for these associations.. MEDLINE/PubMed, EMBASE, Web of Science, and Cochrane Library (inception to June 30, 2021), websites of clinical trial registries (July 10, 2021), and reference lists. There were no language restrictions.. Randomized clinical trials (RCTs) comparing the use of GLP-1 RA drugs with placebo or with non-GLP-1 RA drugs in adults.. Two reviewers independently extracted data according to the PRISMA recommendations and assessed the quality of each study with the Cochrane Collaboration risk-of-bias tool. Pooled relative risks (RRs) were calculated using random or fixed-effects models, as appropriate. The quality of evidence for each outcome was assessed using the GRADE (Grading of Recommendations Assessment, Development, and Evaluation) framework.. The primary outcome was the composite of gallbladder or biliary diseases. Secondary outcomes were biliary diseases, biliary cancer, cholecystectomy, cholecystitis, and cholelithiasis. Data analyses were performed from August 5, 2021, to September 3, 2021.. A total of 76 RCTs involving 103 371 patients (mean [SD] age, 57.8 (6.2) years; 41 868 [40.5%] women) were included. Among all included trials, randomization to GLP-1 RA treatment was associated with increased risks of gallbladder or biliary diseases (RR, 1.37; 95% CI, 1.23-1.52); specifically, cholelithiasis (RR, 1.27; 95% CI, 1.10-1.47), cholecystitis (RR, 1.36; 95% CI, 1.14-1.62), and biliary disease (RR, 1.55; 95% CI, 1.08-2.22). Use of GLP-1 RAs was also associated with increased risk of gallbladder or biliary diseases in trials for weight loss (n = 13; RR, 2.29; 95% CI, 1.64-3.18) and for type 2 diabetes or other diseases (n = 63; RR, 1.27; 95% CI, 1.14-1.43; P <.001 for interaction). Among all included trials, GLP-1 RA use was associated with higher risks of gallbladder or biliary diseases at higher doses (RR, 1.56; 95% CI, 1.36-1.78) compared with lower doses (RR, 0.99; 95% CI, 0.73-1.33; P = .006 for interaction) and with longer duration of use (RR, 1.40; 95% CI, 1.26-1.56) compared with shorter duration (RR, 0.79; 95% CI, 0.48-1.31; P = .03 for interaction).. This systematic review and meta-analysis of RCTs found that use of GLP-1 RAs was associated with increased risk of gallbladder or biliary diseases, especially when used at higher doses, for longer durations, and for weight loss.. PROSPERO Identifier: CRD42021271599. Topics: Adult; Cholecystitis; Cholelithiasis; Diabetes Mellitus, Type 2; Female; Glucagon-Like Peptide 1; Glucagon-Like Peptide-1 Receptor; Humans; Male; Middle Aged; Randomized Controlled Trials as Topic; Weight Loss | 2022 |
The effect of glucagon-like peptide-1 receptor agonists on serum uric acid concentration: A systematic review and meta-analysis.
Glucagon-like peptide-1 receptor agonists (GLP-1 RAs) are a class of medications mainly used for the treatment of type 2 diabetes. They improve glucose tolerance, increase insulin secretion and induce weight loss. There is controversy about the effect of GLP-1 RAs on serum uric acid (SUA) concentration. Our systematic review aims to objectively answer whether GLP-1 RAs affect SUA levels.. We performed a systematic search on PubMed, Web of Science, Embase, Scopus and Google Scholar datasets up to 27August 2021 with a language restriction of English only. Randomized controlled trials, observational studies, uncontrolled trials and conference abstracts were included. Studies with insufficient data, irrelevant types of study and follow-up duration of less than a month were excluded from the review. After critical appraisal by the Joanna Briggs Institute checklists, articles underwent data extraction using a prespecified Microsoft Excel sheet.. Of 1004 identified studies, 17 were eligible for inclusion in this systematic review. Pre- to post-administration analysis of GLP-1 RA effects on SUA demonstrated that GLP-1 RAs could significantly reduce SUA concentration (difference in means -0.341, SE 0.063, P value <0.001). However, when compared to placebo, GLP-1RAs did not perform any better in lowering SUA concentration (difference in means -0.455, SE 0.259, P value 0.079). Surprisingly, the active controls, which included insulin, metformin, sodium-glucose co-transporter 2 (SGLT-2) inhibitors and dipeptidyl-peptidase 4 inhibitors, did outperform GLP-1 RAs in reducing SUA concentration (difference in means 0.250, SE 0.038, P value <0.001).. Administration of GLP-1 RAs can result in a significant reduction in SUA concentration. However, this reduction is less than that seen with the use of insulin, metformin and SGLT-2 inhibitors. Topics: Diabetes Mellitus, Type 2; Glucagon-Like Peptide 1; Glucagon-Like Peptide-1 Receptor; Glucose; Humans; Hypoglycemic Agents; Insulin; Metformin; Sodium-Glucose Transporter 2 Inhibitors; Uric Acid | 2022 |
Glucagon-like Peptide-1 Receptor Agonists in the Management of Type 2 Diabetes Mellitus and Obesity: The Impact of Pharmacological Properties and Genetic Factors.
Glucagon-like peptide-1 (GLP-1) receptor agonists are a new class of antihyperglycemic drugs that enhance appropriate pancreatic β-cell secretion, pancreatic α-cell (glucagon) suppression, decrease liver glucose production, increase satiety through their action on the central nervous system, slow gastric emptying time, and increase insulin action on peripheral tissue. They are effective in the management of type 2 diabetes mellitus and have a favorable effect on weight loss. Their cardiovascular and renal safety has been extensively investigated and confirmed in many clinical trials. Recently, evidence has shown that in addition to the existing approaches for the treatment of obesity, semaglutide in higher doses promotes weight loss and can be used as a drug to treat obesity. However, some T2DM and obese patients do not achieve a desired therapeutic effect of GLP-1 receptor agonists. This could be due to the multifactorial etiologies of T2DM and obesity, but genetic variability in the GLP-1 receptor or signaling pathways also needs to be considered in non-responders to GLP-1 receptor agonists. This review focuses on the pharmacological, clinical, and genetic factors that may influence the response to GLP-1 receptor agonists in the treatment of type 2 diabetes mellitus and obesity. Topics: Diabetes Mellitus, Type 2; Glucagon-Like Peptide 1; Glucagon-Like Peptide-1 Receptor; Humans; Hypoglycemic Agents; Incretins; Obesity; Weight Loss | 2022 |
Effect of the Glucagon-Like Peptide-1 Receptor Agonists on Autonomic Function in Subjects with Diabetes: A Systematic Review and Meta-Analysis.
In addition to the metabolic effects in diabetes, glucagon-like peptide 1 receptor (GLP-1R) agonists lead to a small but substantial increase in heart rate (HR). However, the GLP-1R actions on the autonomic nervous system (ANS) in diabetes remain debated. Therefore, this meta-analysis evaluates the effect of GLP-1R agonist on measures of ANS function in diabetes.. According to the Cochrane Collaboration and Preferred Reporting Items for Systematic reviews and Meta-Analyses (PRISMA) statement, we conducted a meta-analysis considering clinical trials in which the autonomic function was evaluated in diabetic subjects chronically treated with GLP-1R agonists. The outcomes were the change of ANS function measured by heart rate variability (HRV) and cardiac autonomic reflex tests (CARTs).. In the studies enrolled, HR significantly increased after treatment (P<0.001), whereas low frequency/high frequency ratio did not differ (P=0.410); no changes in other measures of HRV were detected. Considering CARTs, only the 30:15 value derived from lying-to-standing test was significantly lower after treatment (P=0.002), but only two studies reported this measurement. No differences in other CARTs outcome were observed.. The meta-analysis confirms the HR increase but seems to exclude an alteration of the sympatho-vagal balance due to chronic treatment with GLP-1R agonists in diabetes, considering the available measures of ANS function. Topics: Autonomic Nervous System; Diabetes Mellitus, Type 2; Glucagon-Like Peptide 1; Glucagon-Like Peptide-1 Receptor; Humans | 2022 |
Lipid Profile Changes Associated with SGLT-2 Inhibitors and GLP-1 Agonists in Diabetes and Metabolic Syndrome.
The introduction of sodium glucose transporter-2 inhibitors and glucagon-like peptide-1 receptor agonists in type 2 diabetes mellitus treatment has shown an unexpectedly significant improvement in heart disease outcome trials. Although they have very different modes of action, a portion of the salutary cardiovascular disease improvement may be related to their impact on diabetic dyslipidemia. As discussed in this focused review, the sodium glucose transporter-2 inhibitors as a class show a mild increase in low-density lipoprotein (LDL) and high-density lipoprotein (HDL) cholesterol levels, while triglycerides (TG) decrease inconsistently. In particular, the rise in LDL appears to be related to the less atherogenic, large buoyant LDL particles. The glucagon-like peptide-1 receptor agonists show more of an impact on weight loss and improvement in the underlying low HDL and high TG dyslipidemia. The effect of sodium glucose transporter-2 inhibitors and glucagon-like peptide 1 receptor agonists when used in combination remains largely unknown. Also unexplored is difference in effect of these medications among various ethnicities and metabolic syndrome. Topics: Cardiovascular Diseases; Diabetes Mellitus, Type 2; Dyslipidemias; Glucagon-Like Peptide 1; Glucagon-Like Peptide-1 Receptor; Humans; Hypoglycemic Agents; Metabolic Syndrome; Sodium-Glucose Transporter 2 Inhibitors; Triglycerides | 2022 |
Revisiting the concept of incretin and enteroendocrine L-cells as type 2 diabetes mellitus treatment.
The significant growth in type 2 diabetes mellitus (T2DM) prevalence strikes a common threat to the healthcare and economic systems globally. Despite the availability of several anti-hyperglycaemic agents in the market, none can offer T2DM remission. These agents include the prominent incretin-based therapy such as glucagon-like peptide-1 receptor (GLP-1R) agonists and dipeptidyl peptidase-4 inhibitors that are designed primarily to promote GLP-1R activation. Recent interest in various therapeutically useful gastrointestinal hormones in T2DM and obesity has surged with the realisation that enteroendocrine L-cells modulate the different incretins secretion and glucose homeostasis, reflecting the original incretin definition. Targeting L-cells offers promising opportunities to mimic the benefits of bariatric surgery on glucose homeostasis, bodyweight management, and T2DM remission. Revising the fundamental incretin theory is an essential step for therapeutic development in this area. Therefore, the present review explores enteroendocrine L-cell hormone expression, the associated nutrient-sensing mechanisms, and other physiological characteristics. Subsequently, enteroendocrine L-cell line models and the latest L-cell targeted therapies are reviewed critically in this paper. Bariatric surgery, pharmacotherapy and new paradigm of L-cell targeted pharmaceutical formulation are discussed here, offering both clinician and scientist communities a new common interest to push the scientific boundary in T2DM therapy. Topics: Animals; Diabetes Mellitus, Type 2; Dipeptidyl-Peptidase IV Inhibitors; Glucagon-Like Peptide 1; Glucagon-Like Peptide-1 Receptor; Glucose; Hypoglycemic Agents; Incretins; L Cells; Mice | 2022 |
Efficacy of GLP-1 RA Approved for Weight Management in Patients With or Without Diabetes: A Narrative Review.
The approval of once daily liraglutide, 3.0 mg, and once weekly semaglutide, 2.4 mg, for chronic weight management provides a novel effective strategy against obesity. The reliable models that might predict weight reducing potential at the individual level have not been identified yet. However, the coexistence of diabetes has been consistently related with less effective response than in people without this comorbidity. We aimed to review the efficacy of GLP-1 RAs approved for weight management in individuals with and without diabetes and discuss some potential mechanisms for consistently observed differences in efficacy between these two populations. The mean weight loss difference between GLP-1 RAs and placebo as add-on to lifestyle intervention in patients with diabetes was 4% to 6.2% compared to 6.1 to 17.4% in people without diabetes. Semaglutide compared to liraglutide resulted in greater weight loss. Some hypothetical explanations for the weaker anti-obesity response for both GLP-1 RAs in people with diabetes include the background medications that promote weight gain, the fear of hypoglycaemia inherently related to the treatment of diabetes, a decrease in glycosuria and subsequently less weight loss in diabetics, an altered microbiota in patients with obesity and diabetes and a genetic background that predispose to weight gain in patients with diabetes. Moreover, people with diabetes may have had obesity for longer and may be less adherent to exercise, which seems to potentiate the effects of GLP-1 RA. Emerging multimodal approaches combining peptides targeting receptors at different levels might therefore be of additional benefit particularly in patients with diabetes. Topics: Diabetes Mellitus, Type 2; Glucagon-Like Peptide 1; Glucagon-Like Peptide-1 Receptor; Glucagon-Like Peptides; Humans; Hypoglycemic Agents; Liraglutide; Obesity; Weight Gain; Weight Loss | 2022 |
Slow and Steady Wins the Race: 25 Years Developing the GLP-1 Receptor as an Effective Target for Weight Loss.
Recent evidence from clinical trials supports the efficacy and tolerability of glucagon-like peptide 1 (GLP-1) receptor agonists as useful agents for weight loss. Although originally developed as glucose lowering agents for people with type 2 diabetes, progress in research over the last 3 decades has demonstrated that GLP-1 receptor agonists act in the central nervous system to reduce food intake. This minireview summarizes key aspects of GLP-1 biology and the clinical studies supporting the utility of the GLP-1 receptor signaling system as a therapeutic target for weight loss. Topics: Diabetes Mellitus, Type 2; Glucagon-Like Peptide 1; Glucagon-Like Peptide-1 Receptor; Humans; Hypoglycemic Agents; Weight Loss | 2022 |
Glucagon-like peptide-1 (GLP-1) receptor agonists and cardiovascular events in patients with type 2 diabetes mellitus: a meta-analysis of double-blind, randomized, placebo-controlled clinical trials.
The cardiovascular effects of glucagon-like peptide-1 (GLP-1) receptor agonists are still controversial in the treatment of type 2 diabetes mellitus (T2DM) patients. The purpose of this study was to evaluate the risk of cardiovascular events of GLP-1 (albiglutide, exenatide, liraglutide, semaglutide, lixisenatide and dulaglutide) receptor agonists in T2DM patients.. PubMed and Embase were searched to find relevant randomized controlled trials (RCTs) from inception to June 2019 that evaluated the effect of GLP-1 receptor agonists on cardiovascular events in patients with T2DM. The T2DM patients of all the eligible trials received either GLP-1 therapy or placebo, and the cardiovascular outcomes included death from cardiovascular causes, fatal or non-fatal myocardial infarction and fatal or non-fatal stroke.. We included 6 multinational double-blind randomized placebo-control trials that included a total of 52821 T2DM patients. The results indicated that GLP-1 receptor agonists reduced the risk of death from cardiovascular causes (RR: 0.90; 95% CI: 0.83-0.97; P = 0.004) and fatal or non-fatal stroke (RR: 0.85; 95% CI: 0.77-0.94; P = 0.001) compared with the placebo controls. But GLP-1 receptor agonists did not significantly alter the fatal or non-fatal myocardial infarction compared with the placebo (RR: 0.91; 95% CI: 0.82 - 1.01; P = 0.06).. We concluded that GLP-1 receptor agonist therapy could reduce the risk of death from cardiovascular causes and fatal or non-fatal stroke compared with the placebo in the treatment of T2DM patients in trials with cardiovascular outcomes. Topics: Cardiovascular Diseases; Diabetes Mellitus, Type 2; Glucagon-Like Peptide 1; Glucagon-Like Peptide-1 Receptor; Humans; Hypoglycemic Agents; Myocardial Infarction; Randomized Controlled Trials as Topic; Stroke | 2022 |
Neuroprotective effects of glucagon-like peptide-1 (GLP-1) analogues in epilepsy and associated comorbidities.
Epilepsy is a common neurological condition induced by losing equilibrium of different pathway as well as neurotransmitters that affects over 50 million people globally. Furthermore, long-term administration of anti-seizure medications has been associated with psychological adverse effects. Also, epilepsy has been related to an increased prevalence of obesity and called type 2 diabetes mellitus. On the other hand, GLP-1 receptors are located throughout the brain, including the hippocampus, which have been associated to majority of neurological conditions, such as epilepsy and psychiatric disorders. Moreover, the impact of different GLP-1 analogues on diverse neurotransmitter systems and associated cellular and molecular pathways as a potential therapeutic target for epilepsy and associated comorbidities has piqued curiosity. In this regard, the anticonvulsant effects of GLP-1 analogues have been investigated in various animal models and promising results such as anticonvulsants as well as cognitive improvements have been observed. For instance, GLP-1 analogues like liraglutide in addition to their possible anticonvulsant benefits, could be utilized to alleviate mental cognitive problems caused by both epilepsy and anti-seizure medication side effects. In this review and growing protective function of GLP-1 in epilepsy induced by disturbed neurotransmitter pathways and the probable mechanisms of action of GLP-1 analogues as well as the GLP-1 receptor in these effects have been discussed. Topics: Animals; Anticonvulsants; Diabetes Mellitus, Type 2; Epilepsy; Glucagon-Like Peptide 1; Glucagon-Like Peptide-1 Receptor; Humans; Hypoglycemic Agents; Neuroprotective Agents; Neurotransmitter Agents | 2022 |
Management of type 2 diabetes with the dual GIP/GLP-1 receptor agonist tirzepatide: a systematic review and meta-analysis.
Tirzepatide is a novel dual glucose-dependent insulinotropic peptide (GIP) and glucagon-like peptide-1 receptor agonist (GLP-1 RA) currently under review for marketing approval. Individual trials have assessed the clinical profile of tirzepatide vs different comparators. We conducted a systematic review and meta-analysis to assess the efficacy and safety of tirzepatide for type 2 diabetes.. A dose-dependent superiority on glycaemic efficacy and body weight reduction was evident with tirzepatide vs placebo, GLP-1 RAs and basal insulin. Tirzepatide did not increase the odds of hypoglycaemia but was associated with increased incidence of gastrointestinal adverse events. Study limitations include presence of statistical heterogeneity in the meta-analyses for change in HbA Topics: Blood Glucose; Body Weight; Diabetes Mellitus, Type 2; Diarrhea; Gastric Inhibitory Polypeptide; Glucagon-Like Peptide 1; Glucagon-Like Peptide-1 Receptor; Glycated Hemoglobin; Humans; Hypoglycemia; Hypoglycemic Agents; Insulins; Treatment Outcome | 2022 |
Effect of glucagon-like peptide 1 receptor agonists on albuminuria in adult patients with type 2 diabetes mellitus: A systematic review and meta-analysis.
To determine the effect of glucagon-like peptide 1 receptor agonists (GLP-1RAs) on albuminuria in adult patients with type 2 diabetes mellitus (T2DM).. Medline Ovid, Scopus, Web of Science, EMCARE and CINAHL databases from database inception until 27 January 2022. Studies were eligible for inclusion if they were randomized controlled trials that involved treatment with a GLP-1RA in adult patients with T2DM and assessed the effect on albuminuria in each treatment arm. Data extraction was conducted independently by three individual reviewers. The PRISMA guidelines were followed regarding data extraction and quality assessment. Data were pooled using a random effects inverse variance model and all analysis was carried out with RevMan 5.4 software. The Jadad scoring tool was employed to assess the quality of evidence and risk of bias in the randomized controlled trials.. The initial search revealed 2419 articles, of which 19 were included in this study. An additional three articles were identified from hand-searching references of included reviews. Therefore, in total, 22 articles comprising 39 714 patients were included. Meta-analysis suggested that use of GLP1-RAs was associated with a reduction in albuminuria in patients with T2DM (weighted mean difference -16.14%, 95% CI -18.42 to -13.86%; p < .0001) compared with controls.. This meta-analysis indicates that GLP-1RAs are associated with a significant reduction in albuminuria in adult patients with T2DM when compared with placebo. Topics: Albuminuria; Diabetes Mellitus, Type 2; Glucagon-Like Peptide 1; Glucagon-Like Peptide-1 Receptor; Humans; Hypoglycemic Agents; Randomized Controlled Trials as Topic | 2022 |
Comparisons of pleiotropic effects of SGLT2 inhibition and GLP-1 agonism on cardiac glucose intolerance in heart dysfunction.
Recent studies discuss the evidence of lesser degrees of hyperglycemia contribution to cardiovascular disease (CVD) than impaired glucose tolerance. Indeed, the biggest risk for CVD seems to shift to glucose intolerance in humans with insulin resistance. Although there is a connection between abnormal insulin signaling and heart dysfunction in diabetics, there is also a relation between cardiac insulin resistance and aging heart failure (HF). Moreover, studies have revealed that HF is associated with generalized insulin resistance. Recent clinical outcomes parallel to the experimental data undertaken with antihyperglycemic drugs have shown their beneficial effects on the cardiovascular system through a direct effect on the myocardium, beyond their ability to lower blood glucose levels and their receptor-associated actions. In this regard, several new-class drugs, such as glucagon-like peptide 1 receptor agonists (GLP-1Ra) and sodium-glucose cotransport 2 inhibitors (SGLT2i), can improve cardiac health beyond their ability to control glycemia. In recent years, great improvements have been made toward the possibility of direct heart-targeting effects including modulation of the expression of specific cardiac genes in vivo for therapeutic purposes. However, many questions remain unanswered, regarding their therapeutic effects on cardiomyocytes in heart failure, although there are various cellular levels studies with these drugs. There are also some important comparative studies on the role of SGLT2i versus GLP-1Ra in patients with and without CVD as well as with or without hyperglycemia. Here, we sought to summarize and interpret the available evidence from clinical studies focusing on the effects of either GLP-1Ra or SGLT-2i or their combinations on cardiac structure and function. Furthermore, we documented data from experimental studies, at systemic, organ, and cellular levels. Overall, one can summarize that both clinical and experimental data support that either SGLT2i or GLP-1R agonists have similar benefits as cardioprotective agents in patients with or without impaired glucose tolerance. Topics: Cardiovascular Diseases; Diabetes Mellitus, Type 2; Glucagon-Like Peptide 1; Glucose Intolerance; Heart Failure; Humans; Hypoglycemic Agents; Insulin Resistance; Sodium-Glucose Transporter 2 Inhibitors | 2022 |
Designing a Dual GLP-1R/GIPR Agonist from Tirzepatide: Comparing Residues Between Tirzepatide, GLP-1, and GIP.
Improving type 2 diabetes using incretin analogues is becoming increasingly plausible. Currently, tirzepatide is the most promising listed incretin analogue. Here, I briefly explain the evolution of drugs of this kind, analyze the residue discrepancies between tirzepatide and endogenous incretins, summarize some existing strategies for prolonging half-life, and present suggestions for future research, mainly involving biased functions. This review aims to present some useful information for designing a dual glucagon like peptide-1 receptor/glucose-dependent insulinotropic polypeptide receptor agonist. Topics: Diabetes Mellitus, Type 2; Gastric Inhibitory Polypeptide; Glucagon-Like Peptide 1; Humans; Incretins; Receptors, G-Protein-Coupled; Receptors, Gastrointestinal Hormone | 2022 |
The role of oral semaglutide in managing type 2 diabetes in Indian clinical settings: Addressing the unmet needs.
Despite their established benefits, glucagon-like peptide-1 receptor agonists (GLP-1 RAs) remain underutilized for type 2 diabetes mellitus (T2DM) management, which indicates that subcutaneous injection is an unfavorable mode of delivery from the patient's perspective. This review summarizes existing challenges related to medication adherence and the use of antihyperglycemia injectables, revisits the established safety and efficacy of oral semaglutide, and explores its features and considerations for use among the Indian T2DM population.. We performed a literature search using MEDLINE and the National Institutes of Health Clinical Trials Registry from July 1, 2016, to July 1, 2021, to identify publications on oral semaglutide approval, T2DM treatment guidelines, and clinical evidence for oral drug formulation.. Oral semaglutide is the first oral GLP-1 RA approved for T2DM patients based on phase 3, randomized PIONEER trials. The multitargeted action of this drug offers glycemic control, weight control, and cardiovascular, renal, and additional benefits, including patient convenience and enhanced medication adherence. In addition to achieving glycemic control, the cost of semaglutide is reported to be lower than other GLP-1 RA in the West, thus potentially mitigating the economic burden that appears to be high among the Indian population.. Currently, there is no data available on oral semaglutide in Indian clinical settings. However, significant improvements in glycemic control, cardiac and renal benefits, as well as weight loss across clinical trials should encourage clinicians to prioritize oral semaglutide over other antidiabetic agents. Topics: Diabetes Mellitus, Type 2; Glucagon-Like Peptide 1; Glucagon-Like Peptide-1 Receptor; Glucagon-Like Peptides; Humans; Hypoglycemic Agents | 2022 |
Cardiovascular effects of GLP-1 receptor agonism.
Glucagon-like peptide-1 (GLP-1) receptor agonists are extensively used in type 2 diabetic patients for the effective control of hyperglycemia. It is now clear from outcomes trials that this class of drugs offers important additional benefits to these patients due to reducing the risk of developing major adverse cardiac events (MACE). This risk reduction is, in part, due to effective glycemic control in patients; however, the various outcomes trials, further validated by subsequent meta-analysis of the outcomes trials, suggest that the risk reduction in MACE is also dependent on glycemic-independent mechanisms operant in cardiovascular tissues. These glycemic-independent mechanisms are likely mediated by GLP-1 receptors found throughout the cardiovascular system and by the complex signaling cascades triggered by the binding of agonists to the G-protein coupled receptors. This heterogeneity of signaling pathways underlying different downstream effects of GLP-1 agonists, and the discovery of biased agonists favoring specific signaling pathways, may have import in the future treatment of MACE in these patients. We review the evidence supporting the glycemic-independent evidence for risk reduction of MACE by the GLP-1 receptor agonists and highlight the putative mechanisms underlying these benefits. We also comment on the different signaling pathways which appear important for mediating these effects. Topics: Cardiovascular Diseases; Cardiovascular System; Diabetes Mellitus, Type 2; Glucagon-Like Peptide 1; Glucagon-Like Peptide-1 Receptor; Humans; Hypoglycemic Agents | 2022 |
Application of glucagon-like peptide-1 receptor antagonists in fibrotic diseases.
Fibrosis can occur in various organs, leading to structural destruction, dysfunction, and even organ failure. Hence, organ fibrosis is being actively researched worldwide. Glucagon-like peptide-1 (GLP-1), a naturally occurring hormone, binds to a G-protein-coupled receptor widely distributed in the pancreas, kidney, lung, heart, gastrointestinal tract, and other organs. Synthetic GLP-1 analogs can be used as GLP-1 receptor agonists (GLP-1RAs) for treating diabetes mellitus. In recent years, GLP-1RAs have also been found to exert anti-inflammatory, antioxidant, and cardiovascular protective effects. GLP-1RAs have also been shown to inhibit fibrosis of solid organs, such as the lung, heart, liver, and kidney. In this review, we discuss the advancements in research on the role of GLP-1RAs in the fibrosis of the heart, lung, liver, kidney, and other organs to obtain new clues for treating organ fibrosis. Topics: Diabetes Mellitus, Type 2; Fibrosis; Glucagon-Like Peptide 1; Glucagon-Like Peptide-1 Receptor; Humans; Hypoglycemic Agents | 2022 |
Crosstalk between incretin hormones, Th17 and Treg cells in inflammatory diseases.
Intestinal epithelial cells constantly crosstalk with the gut microbiota and immune cells of the gut lamina propria. Enteroendocrine cells, secrete hormones, such as incretin hormones, which participate in host physiological events, such as stimulating insulin secretion, satiety, and glucose homeostasis. Interestingly, evidence suggests that the incretin pathway may influence immune cell activation. Consequently, drugs targeting the incretin hormone signaling pathway may ameliorate inflammatory diseases such as inflammatory bowel diseases, cancer, and autoimmune diseases. In this review, we discuss how these hormones may modulate two subsets of CD4 + T cells, the regulatory T cells (Treg)/Th17 axis important for gut homeostasis: thus, preventing the development and progression of inflammatory diseases. We also summarize the main experimental and clinical findings using drugs targeting the glucose-dependent insulinotropic polypeptide (GIP) and glucagon-like peptide (GLP-1) signaling pathways and their great impact on conditions in which the Treg/Th17 axis is disturbed such as inflammatory diseases and cancer. Understanding the role of incretin stimulation in immune cell activation and function, might contribute to new therapeutic designs for the treatment of inflammatory diseases, autoimmunity, and tumors. Topics: Diabetes Mellitus, Type 2; Gastric Inhibitory Polypeptide; Glucagon-Like Peptide 1; Glucose; Humans; Incretins; Insulin; T-Lymphocytes, Regulatory | 2022 |
Effect of glucagon-like peptide 1 receptor agonists on the renal protection in patients with type 2 diabetes: A systematic review and meta-analysis.
Glucagon-like peptide 1(GLP-1) receptor agonists are used in patients with type 2 diabetes as hypoglycemic drugs; a growing body of evidence has clarified their renoprotective benefits. We performed a meta-analysis to summarize the most recent evidence on the renal benefits of GLP-1 receptor agonists from clinical trials of patients with type 2 diabetes.. This meta-analysis used a fixed-effects model to estimate the risk ratio (RR) with 95% confidence intervals (CIs) to investigate the effect of GLP-1 receptor agonists on the renal protection. The outcomes were a composite renal outcome, estimated glomerular filtration rate (eGFR) decrease, new macroalbuminuria, doubling of serum creatinine, end-stage renal disease (ESRD) and renal death. We also checked the composite renal outcome of the patient subgroups based on the structural source of human GLP-1 or exendin-4.. Among the 12 articles screened, seven studies involving 48101 patients met pre-specified criteria and were included. In general, the use of GLP-1 receptor agonists reduced the risk of the composite renal outcome by 17% (RR 0·83 [95% CI 0·79-0·88]; P < 0·00001), with no significant interaction in subgroups analysis (P = 0.66); the risk of new-onset of persistent macroalbuminuria was reduced by 25% (RR 0·75 [95%CI 0·69-0·81]; P < 0·00001) compared to placebo. However, GLP-1 receptor agonists had no significant effect on eGFR decrease (RR 0·92 [95% CI 0·83-1.01]; P = 0·09), doubling of serum creatinine (RR 0·97 [95% CI 0·78-1.21]; P = 0·79), or end-stage renal disease (RR 0·81 [95% CI 0·62-1.06]; P = 0·12) compared to placebo or insulin glargine (AWARD-7) in patients with type 2 diabetes.. GLP-1 receptor agonists, regardless of their structural homology, have significant benefits in reducing the risk of the composite renal outcome, especially in new macroalbuminuria compared with placebo or insulin glargine in patients with type 2 diabetes. Topics: Creatinine; Diabetes Mellitus, Type 2; Exenatide; Glucagon-Like Peptide 1; Glucagon-Like Peptide-1 Receptor; Humans; Hypoglycemic Agents; Insulin Glargine; Kidney Failure, Chronic | 2022 |
A Novel Dual Incretin Agent, Tirzepatide (LY3298176), for the Treatment of Type 2 Diabetes Mellitus and Cardiometabolic Health.
The incretin hormone system is the target of multiple type 2 diabetes mellitus (T2DM) treatments because defects in this system play major roles in the pathogenesis of diabetes. Currently, the glucagon-like peptide-1 receptor agonists (GLP-1 RAs) are recommended for patients with atherosclerotic cardiovascular (CV) disease and those at high risk for atherosclerotic CV disease. In addition to the favorable CV effects, GLP-1 RAs also provide robust lowering of hemoglobin A1c and weight. Although these factors make GLP-1 RAs attractive options for T2DM, the currently available agents have no effect on glucose-dependent insulinotropic polypeptide (GIP). Patients with T2DM are known to have GIP defect which is significant due to its profound insulinotropic effects. Tirzepatide is a novel incretin agent currently recently approved by the Food and Drug Administration for the treatment of T2DM. This first-in-class agent serves as a coagonist for both the GLP-1 and GIP receptors. In this review, we report on the pharmacologic mechanism of GLP-1, GIP, and coagonist effects on the cardiometabolic system. In addition, we review the glycemic lowering, weight loss effects, and other cardiometabolic outcomes of tirzepatide based on phase 2 and 3 data. The safety profile of tirzepatide is consistent across all phase 3 trials. The most common adverse effects are gastrointestinal symptoms, but they generally have a low risk for discontinuation. Overall, preliminary data suggest that tirzepatide is an efficacious and safe agent for the treatment of T2DM. Topics: Cardiovascular Diseases; Diabetes Mellitus, Type 2; Gastric Inhibitory Polypeptide; Glucagon-Like Peptide 1; Humans; Hypoglycemic Agents; Incretins | 2022 |
Tirzepatide, a New Era of Dual-Targeted Treatment for Diabetes and Obesity: A Mini-Review.
The prevalence of obesity and diabetes is an increasing global problem, especially in developed countries, and is referred to as the twin epidemics. As such, advanced treatment approaches are needed. Tirzepatide, known as a 'twincretin', is a 'first-in-class' and the only dual glucagon-like peptide-1 (GLP-1) and glucose-dependent insulinotropic peptide (GIP) receptor agonist, that can significantly reduce glycemic levels and improve insulin sensitivity, as well as reducing body weight by more than 20% and improving lipid metabolism. This novel anti-diabetic drug is a synthetic peptide analog of the human GIP hormone with a C Topics: Diabetes Mellitus, Type 2; Gastric Inhibitory Polypeptide; Glucagon-Like Peptide 1; Glucagon-Like Peptide-1 Receptor; Humans; Hypoglycemic Agents; Obesity | 2022 |
Effect of glucagon-like peptide-1 (GLP-1) analogues on epicardial adipose tissue: A meta-analysis.
Glucagon-like peptide-1 (GLP-1) analogues reduce body fat and cardiovascular events in patients with type 2 diabetes. Accumulation of epicardial adipose tissue (EAT) is associated with increased cardio-metabolic risks and coronary events in type 2 diabetes.. A systematic review and meta-analysis were performed from Glucagon-like peptide-1 analogues therapy on type 2 diabetes patients, reporting data from changes in EAT, after searching the PubMed/MEDLINE, Embase, Science Direct, Scopus, Google Scholar, and Cochrane databases.. This meta-analysis suggests that the amount of EAT is significantly reduced in T2D patients with Glucagon-like peptide-1 analogues. Topics: Adipose Tissue; Diabetes Mellitus, Type 2; Glucagon-Like Peptide 1; Glucagon-Like Peptide-1 Receptor; Humans; Hypoglycemic Agents | 2022 |
Tirzepatide: First Approval.
Tirzepatide (Mounjaro™) is a single molecule that combines dual agonism of glucose-dependent insulinotropic polypeptide (GIP) and glucagon-like peptide-1 (GLP-1) receptors. Native GIP and GLP-1 are incretin hormones that stimulate insulin secretion and decrease glucagon secretion. GIP also plays a role in nutrient and energy metabolism, while GLP-1 also delays gastric emptying, supresses appetite and improves satiety. Eli Lilly is developing tirzepatide for the treatment of type 2 diabetes mellitus (T2DM), obesity, cardiovascular disorders in T2DM, heart failure, non-alcoholic steatohepatitis, obstructive sleep apnoea and for reducing mortality/morbidity in obesity. In May 2022, tirzepatide received its first approval in the USA to improve glycaemic control in adults with T2DM, as an adjunct to diet and exercise. Tirzepatide is in phase III development for heart failure, obesity and cardiovascular disorders in T2DM, and in phase II development for non-alcoholic steatohepatitis. This article summarizes the milestones in the development of tirzepatide leading to this first approval for T2DM. Topics: Adult; Diabetes Mellitus, Type 2; Fatty Liver; Gastric Inhibitory Polypeptide; Glucagon-Like Peptide 1; Glucagon-Like Peptide-1 Receptor; Heart Failure; Humans; Obesity | 2022 |
A new era for oral peptides: SNAC and the development of oral semaglutide for the treatment of type 2 diabetes.
Glucagon-like peptide-1 (GLP-1) receptor agonists (GLP-1RAs) were first introduced for the treatment of type 2 diabetes (T2D) in 2005. Despite the high efficacy and other benefits of GLP-1RAs, their uptake was initially limited by the fact that they could only be administered by injection. Semaglutide is a human GLP-1 analog that has been shown to significantly improve glycemic control and reduce body weight, in addition to improving cardiovascular outcomes, in patients with T2D. First approved as a once-weekly subcutaneous injection, semaglutide was considered an ideal peptide candidate for oral delivery with a permeation enhancer on account of its low molecular weight, long half-life, and high potency. An oral formulation of semaglutide was therefore developed by co-formulating semaglutide with sodium N-(8-[2-hydroxybenzoyl]amino)caprylate, a well-characterized transcellular permeation enhancer, to produce the first orally administered GLP-1RA. Pharmacokinetic analysis showed that stable steady-state concentrations could be achieved with once-daily dosing owing to the long half-life of oral semaglutide. Upper gastrointestinal disease and renal and hepatic impairment did not affect the pharmacokinetic profile. In the phase III PIONEER clinical trial program, oral semaglutide was shown to reduce glycated hemoglobin and body weight compared with placebo and active comparators in patients with T2D, with no new safety signals reported. Cardiovascular efficacy and safety are currently being assessed in a dedicated outcomes trial. The development of an oral GLP-1RA represents a significant milestone in the management of T2D, providing an additional efficacious treatment option for patients. Topics: Body Weight; Caprylates; Diabetes Mellitus, Type 2; Glucagon-Like Peptide 1; Glucagon-Like Peptide-1 Receptor; Glucagon-Like Peptides; Glycated Hemoglobin; Humans; Hypoglycemic Agents; Peptides; Sodium | 2022 |
[Heart and diabetes : What is the importance of GLP-1 receptor agonists in cardiology?]
Patients with diabetes have a high cardiovascular risk, which can be efficiently addressed by the administration of glucagon-like peptide 1 (GLP-1) receptor agonists (GLP-1-RA). Nevertheless, the use of GLP-1-RA has so far been limited in cardiology. This review describes the existing evidence for cardiovascular benefits of GLP-1-RA and presents the available substances with recommendations on administration and titration and taking the side effects into consideration.. Patienten mit Diabetes haben ein hohes kardiovaskuläres Risiko, das durch die Gabe von GLP(„glucagon-like peptide“)-1-Rezeptor-Agonisten (GLP-1-RA) effektiv gesenkt werden kann. Trotzdem finden GLP-1-RA bisher nur eine geringe Anwendung in der Kardiologie. Die vorliegende Übersicht beschreibt die bestehende Evidenz für den kardiovaskulären Nutzen der GLP-1-RA und stellt die zur Verfügung stehenden Substanzen mit Empfehlungen zu Applikation und Auftitration und unter Berücksichtigung von Nebenwirkungen dar. Topics: Cardiology; Cardiovascular Diseases; Diabetes Mellitus, Type 2; Glucagon-Like Peptide 1; Glucagon-Like Peptide-1 Receptor; Humans; Hypoglycemic Agents | 2022 |
GLP-1 agonists: superior for mind and body in antipsychotic-treated patients?
Antipsychotics (APDs) represent a core treatment for severe mental disorders (SMEs). Providing symptomatic relief, APDs do not exert therapeutic effects on another clinically significant domain of serious mental disorders, cognitive impairment. Moreover, adverse metabolic effects (diabetes, weight gain, dyslipidemia, and increased cardiovascular risk) are common during treatment with APDs. Among pharmacological candidates reversing APD-induced metabolic adverse effects, glucagon-like peptide-1 (GLP-1) receptor agonists (GLP-1 RAs), approved for both diabetes and recently for obesity treatment, stand out due to their favorable effects on peripheral metabolic parameters. Interestingly, GLP-1 RAs are also proposed to have pro-cognitive effects. Particularly in terms of dual therapeutic mechanisms potentially improving both central nervous system (CNS) deficits and metabolic burden, GLP-1 RAs open a new perspective and assume a clinically advantageous position. Topics: Antipsychotic Agents; Diabetes Mellitus, Type 2; Glucagon-Like Peptide 1; Glucagon-Like Peptide-1 Receptor; Humans; Hypoglycemic Agents; Obesity; Weight Gain | 2022 |
[Renal effects of GLP-1 agonists in type 2 diabetes].
The prevalence of type 2 diabetes mellitus (DM2) is increasing, generating a great impact both at individual and public health level. Nearly half of the patients with DM2 develop impaired renal function, so nephron-protection is highly important. The robust body of evidence that shifted the therapeutic focus from glycemic to cardio-renal metabolic therapy in DM2 led to the inclusion of new therapies with cardiovascular and renal benefits in international guidelines. Type 1 glucagon (GLP-1) receptor agonists have showed favorable effects on renal function and their potential protective actions are multifactorial, beyond glycemic control. These benefits have been demonstrated in efficacy and safety clinical studies, as well as in cardiovascular outcomes and real-life studies. This comprehensive review describes the direct and indirect effects of these molecules, as well as evidence obtained from pivotal clinical (LEADER, SUSTAIN 6 and REWIND) and real-life studies demonstrating their beneficial effects on renal function, and also introduces expectations of future results from ongoing studies with renal endpoints.. La prevalencia de diabetes mellitus tipo 2 (DM2) está en aumento, generando un gran impacto tanto a nivel individual como en salud pública. Cerca de la mitad de los pacientes con DM2 sufren un deterioro de la función renal, por esto la nefroprotección resulta de fundamental importancia. El conjunto de evidencia que cambió del enfoque terapéutico glucocéntrico al cardiorrenometabólico en la DM2 motivó la inclusión en las recomendaciones internacionales de nuevas terapias con beneficios cardiovasculares y renales. Los agonistas del receptor del péptido similar al glucagón tipo 1 (GLP-1) tienen efectos favorables sobre la función renal y sus posibles acciones protectoras son multifactoriales, más allá del control glucémico. Estos beneficios han sido demostrados en los estudios clínicos de eficacia y seguridad, así como también en los estudios de resultados cardiovasculares y de vida real. En esta revisión narrativa se describen los efectos directos e indirectos de estas moléculas, así como su evidencia en los principales estudios clínicos (LEADER, SUSTAIN 6 y REWIND) y de vida real que demuestran sus efectos beneficiosos sobre la función renal e introduce la expectativa de los resultados futuros de los estudios en curso con objetivos renales. Topics: Cardiovascular Diseases; Diabetes Mellitus, Type 2; Glucagon-Like Peptide 1; Glucagon-Like Peptide-1 Receptor; Humans; Hypoglycemic Agents; Kidney | 2022 |
Intestinal lipid absorption and transport in type 2 diabetes.
Postprandial hyperlipidaemia is an important feature of diabetic dyslipidaemia and plays an important role in the development of cardiovascular disease in individuals with type 2 diabetes. Postprandial hyperlipidaemia in type 2 diabetes is secondary to increased chylomicron production by the enterocytes and delayed catabolism of chylomicrons and chylomicron remnants. Insulin and some intestinal hormones (e.g. glucagon-like peptide-1 [GLP-1]) influence intestinal lipid metabolism. In individuals with type 2 diabetes, insulin resistance and possibly reduced GLP-1 secretion are involved in the pathophysiology of postprandial hyperlipidaemia. Several factors are involved in the overproduction of chylomicrons: (1) increased expression of microsomal triglyceride transfer protein, which is a key enzyme in chylomicron synthesis; (2) higher stability and availability of apolipoprotein B-48; and (3) increased de novo lipogenesis. Individuals with type 2 diabetes present with disorders of cholesterol metabolism in the enterocytes with reduced absorption and increased synthesis. The increased production of chylomicrons in type 2 diabetes is also associated with a reduction in their catabolism, mostly because of a reduction in activity of lipoprotein lipase. Modification of the microbiota, which is observed in type 2 diabetes, may also generate disorders of intestinal lipid metabolism, but human data remain limited. Some glucose-lowering treatments significantly influence intestinal lipid absorption and transport. Postprandial hyperlipidaemia is reduced by metformin, pioglitazone, alpha-glucosidase inhibitors, dipeptidyl peptidase 4 inhibitors and GLP-1 agonists. The most pronounced effect is observed with GLP-1 agonists, which reduce chylomicron production significantly in individuals with type 2 diabetes and have a direct effect on the intestine by reducing the expression of genes involved in intestinal lipoprotein metabolism. The effect of sodium-glucose cotransporter 2 inhibitors on intestinal lipid metabolism needs to be clarified. Topics: Apolipoprotein B-48; Cholesterol; Chylomicron Remnants; Chylomicrons; Diabetes Mellitus, Type 2; Dipeptidyl-Peptidase IV Inhibitors; Glucagon-Like Peptide 1; Glucose; Glycoside Hydrolase Inhibitors; Humans; Hyperlipidemias; Insulin; Intestinal Absorption; Lipid Metabolism; Lipoprotein Lipase; Lipoproteins; Metformin; Pioglitazone; Postprandial Period; Sodium; Triglycerides | 2022 |
GLP-1 RAs and SGLT-2 Inhibitors for Insulin Resistance in Nonalcoholic Fatty Liver Disease: Systematic Review and Network Meta-Analysis.
Glucagon-like peptide-1 receptor agonists (GLP-1 RAs) and sodium-glucose cotransporter-2 (SGLT-2) inhibitors reduce glycaemia and weight and improve insulin resistance (IR). Three electronic databases (Medline, Embase, PubMed) were searched from inception until March 2021. We selected randomized controlled trials comparing GLP-1 RAs and SGLT-2 inhibitors with control in adult NAFLD patients with or without T2DM. Network meta-analyses were performed using fixed and random effect models, and the mean difference (MD) with corresponding 95% confidence intervals (CI) were determined. The within-study risk of bias was assessed with the Cochrane collaborative risk assessment tool RoB.. 25 studies with 1595 patients were included in this network meta-analysis. Among them, there were 448 patients, in 6 studies, who were not comorbid with T2DM. Following a mean treatment duration of 28.86 weeks, compared with the control group, GLP-1 RAs decreased the HOMA-IR (MD [95%CI]; -1.573[-2.523 to -0.495]), visceral fat (-0.637[-0.992 to -0.284]), weight (-2.394[-4.625 to -0.164]), fasting blood sugar (-0.662[-1.377 to -0.021]) and triglyceride (- 0.610[-1.056 to -0.188]). On the basis of existing studies, SGLT-2 inhibitors showed no statistically significant improvement in the above indicators. Compared with SGLT-2 inhibitors, GLP-1 RAs decreased visceral fat (-0.560[-0.961 to -0.131]) and triglyceride (-0.607[-1.095 to -0.117]) significantly.. GLP-1 RAs effectively improve IR in NAFLD, whereas SGLT-2 inhibitors show no apparent effect.. PROSPERO https://www.crd.york.ac.uk/PROSPERO/, CRD42021251704. Topics: Adult; Diabetes Mellitus, Type 2; Glucagon-Like Peptide 1; Humans; Insulin Resistance; Network Meta-Analysis; Non-alcoholic Fatty Liver Disease; Sodium-Glucose Transporter 2 Inhibitors; Triglycerides | 2022 |
Cardiovascular outcomes trials: a paradigm shift in the current management of type 2 diabetes.
Cardiovascular disease (CVD) is the leading cause of mortality and morbidity in patients with type 2 diabetes (T2D). Historical concerns about cardiovascular (CV) risks associated with certain glucose-lowering medications gave rise to the introduction of cardiovascular outcomes trials (CVOTs). Initially implemented to help monitor the CV safety of glucose-lowering drugs in patients with T2D, who either had established CVD or were at high risk of CVD, data that emerged from some of these trials started to show benefits. Alongside the anticipated CV safety of many of these agents, evidence for certain sodium-glucose transporter 2 (SGLT2) inhibitors and glucagon-like peptide-1 receptor agonists (GLP-1 RAs) have revealed potential cardioprotective effects in patients with T2D who are at high risk of CVD events. Reductions in 3-point major adverse CV events (3P-MACE) and CV death have been noted in some of these CVOTs, with additional benefits including reduced risks of hospitalisation for heart failure, progression of renal disease, and all-cause mortality. These new data are leading to a paradigm shift in the current management of T2D, with international guidelines now prioritising SGLT2 inhibitors and/or GLP-1 RAs in certain patient populations. However, clinicians are faced with a large volume of CVOT data when seeking to use this evidence base to bring opportunities to improve CV, heart failure and renal outcomes, and even reduce mortality, in their patients with T2D. The aim of this review is to provide an in-depth summary of CVOT data-crystallising the key findings, from safety to efficacy-and to offer a practical perspective for physicians. Finally, we discuss the next steps for the post-CVOT era, with ongoing studies that may further transform clinical practice and improve outcomes for people with T2D, heart failure or renal disease. Topics: Cardiovascular Diseases; Diabetes Mellitus, Type 2; Glucagon-Like Peptide 1; Glucagon-Like Peptide-1 Receptor; Glucose; Heart Failure; Humans; Hypoglycemic Agents; Sodium-Glucose Transporter 2 Inhibitors | 2022 |
Colonic Delivery of Nutrients for Sustained and Prolonged Release of Gut Peptides: A Novel Strategy for Appetite Management.
Obesity is one of the major global threats to human health and risk factors for cardiometabolic diseases and certain cancers. Glucagon-like peptide-1 (GLP-1) plays a major role in appetite and glucose homeostasis and recently the USFDA approved GLP-1 agonists for the treatment of obesity and type 2 diabetes. GLP-1 is secreted from enteroendocrine L-cells in the distal part of the gastrointestinal (GI) tract in response to nutrient ingestion. Endogenously released GLP-1 has a very short half-life of <2 min and most of the nutrients are absorbed before reaching the distal GI tract and colon, which hinders the use of nutritional compounds for appetite regulation. The review article focuses on nutrients that endogenously stimulate GLP-1 and peptide YY (PYY) secretion via their receptors in order to decrease appetite as preventive action. In addition, various delivery technologies such as pH-sensitive, mucoadhesive, time-dependent, and enzyme-sensitive systems for colonic targeting of nutrients delivery are described. Sustained colonic delivery of nutritional compounds could be one of the most promising approaches to prevent obesity and associated metabolic diseases by, e.g., sustained GLP-1 release. Topics: Appetite; Colon; Diabetes Mellitus, Type 2; Glucagon-Like Peptide 1; Glucose; Humans; Nutrients; Obesity; Peptide YY | 2022 |
Cardiovascular protection by DPP-4 inhibitors in preclinical studies: an updated review of molecular mechanisms.
Dipeptidyl peptidase 4 (DPP4) inhibitors are a class of antidiabetic medications that cause glucose-dependent increase in incretins in diabetic patients. One of the two incretins, glucagon-like peptide-1 (GLP-1), beside its insulinotropic activity, has been studied for extra pancreatic effects. Most of DPP4 inhibitors (DPP4i) have been investigated in in vivo and in vitro models of diabetic and nondiabetic cardiovascular diseases including heart failure, hypertension, myocardial ischemia or infarction, atherosclerosis, and stroke. Results of preclinical studies proved prominent therapeutic potential of DPP4i in cardiovascular diseases, regardless the presence of diabetes. This review aims to present an updated summary of the cardiovascular protective and therapeutic effects of DPP4 inhibitors through the past 5 years focusing on the molecular mechanisms beneath these effects. Additionally, based on the results summary presented here, future studies may be conducted to elucidate or illustrate some of these findings which can add clinical benefits towards management of diabetic cardiovascular complications. Topics: Cardiovascular Diseases; Diabetes Complications; Diabetes Mellitus, Type 2; Dipeptidyl Peptidase 4; Dipeptidyl-Peptidase IV Inhibitors; Glucagon-Like Peptide 1; Glucose; Humans; Hypoglycemic Agents; Incretins | 2022 |
Emerging roles of Glucagon like peptide-1 in the management of autoimmune diseases and diabetes-associated comorbidities.
Currently, gastrointestinal hormone glucagon like peptide-1 (GLP-1) has received significant attention in maintaining glucose homeostasis through mechanisms involving augmentation of insulin, inhibition of glucagon secretion and regulation of gut motility. Therefore, GLP-1 receptor agonist (GLP-1RA) turns to be one of the most promising hypoglycemic agents for the treatment of type 2 diabetes mellitus (T2DM) and obesity. However, the benefits of GLP-1 and GLP-1RAs are not limited to glucose control and weight loss. Here, we provide a concise overview of the roles of GLP-1 and GLP-1RAs in autoimmune disease, cardiovascular disease (CVD), diabetic kidney disease (DKD), diabetic foot ulcer (DFU), polycystic ovary syndrome (PCOS), and Alzheimer's disease (AD) as well as future challenges in this regard. Topics: Autoimmune Diseases; Diabetes Mellitus, Type 2; Female; Glucagon-Like Peptide 1; Glucagon-Like Peptide-1 Receptor; Humans; Hypoglycemic Agents | 2022 |
Transitioning to active-controlled trials to evaluate cardiovascular safety and efficacy of medications for type 2 diabetes.
Cardiovascular (CV) outcome trials (CVOTs) of type 2 diabetes mellitus (T2DM) therapies have mostly used randomized comparison with placebo to demonstrate non-inferiority to establish that the investigational drug does not increase CV risk. Recently, several glucagon-like peptide 1 receptor agonists (GLP-1 RA) and sodium glucose cotransporter 2 inhibitors (SGLT-2i) demonstrated reduced CV risk. Consequently, future T2DM therapy trials could face new ethical and clinical challenges if CVOTs continue with the traditional, placebo-controlled design. To address this challenge, here we review the methodologic considerations in transitioning to active-controlled CVOTs and describe the statistical design of a CVOT to assess non-inferiority versus an active comparator and if non-inferiority is proven, using novel methods to assess for superiority versus an imputed placebo. Specifically, as an example of such methodology, we introduce the statistical considerations used for the design of the "Effect of Tirzepatide versus Dulaglutide on Major Adverse Cardiovascular Events (MACE) in Patients with Type 2 Diabetes" trial (SURPASS CVOT). It is the first active-controlled CVOT assessing antihyperglycemic therapy in patients with T2DM designed to demonstrate CV efficacy of the investigational drug, tirzepatide, a dual glucose-dependent insulinotropic polypeptide and GLP-1 RA, by establishing non-inferiority to an active comparator with proven CV efficacy, dulaglutide. To determine the efficacy margin for the hazard ratio, tirzepatide versus dulaglutide, for the composite CV outcome of death, myocardial infarction, or stroke (MACE-3), which is required to claim superiority versus an imputed placebo, the lower bound of efficacy of dulaglutide compared with placebo was estimated using a hierarchical Bayesian meta-analysis of placebo-controlled CVOTs of GLP-1 RAs. SURPASS CVOT was designed so that when the observed upper bound of the 95% confidence interval of the hazard ratio is less than the lower bound of efficacy of dulaglutide, it demonstrates non-inferiority to dulaglutide by preserving at least 50% of the CV benefit of dulaglutide as well as statistical superiority of tirzepatide to a theoretical placebo (imputed placebo analysis). The presented methods adding imputed placebo comparison for efficacy assessment may serve as a model for the statistical design of future active-controlled CVOTs. Topics: Bayes Theorem; Cardiovascular Diseases; Diabetes Mellitus, Type 2; Drugs, Investigational; Glucagon-Like Peptide 1; Glucagon-Like Peptide-1 Receptor; Humans; Hypoglycemic Agents; Randomized Controlled Trials as Topic; Sodium-Glucose Transporter 2 Inhibitors; Treatment Outcome | 2022 |
Dose titration with the glucagon-like peptide-1 agonist, liraglutide, reduces cue- and drug-induced heroin seeking in high drug-taking rats.
Opioid use disorder (OUD), like other substance use disorders (SUDs), is widely understood to be a disorder of persistent relapse. Despite the use of three FDA-approved medications for OUD, typically in conjunction with behavioral treatments, relapse rates remain unacceptably high. Whereas medication assisted therapy (MAT) reduces the risk of opioid overdose mortality, the benefits of MAT are negated when people discontinue the medications. Currently approved medications present barriers to efficient use, including daily visits to a treatment center or work restrictions. With spiking increases in opioid relapse and death, it is imperative to identify new treatments that can reduce the risk of relapse. Recent evidence suggests that glucagon-like peptide-1 receptor agonists (GLP-1RAs), currently FDA-approved to treat obesity and type two diabetes, may be promising candidates to reduce relapse. GLP-1RAs have been shown to reduce relapse in rats, whether elicited by cues, drug, and/or stress. However, GLP-1RAs also can cause gastrointestinal malaise, and therefore, in humans, the medication typically is titrated up to full dose when initiating treatment. Here, we used a rodent model to test whether cue- and drug-induced heroin seeking can be reduced by the GLP-1RA, liraglutide, when the dose is titrated across the abstinence period and prior to test. The results show this titration regimen is effective in reducing both cue-induced heroin seeking and drug-induced reinstatement of heroin seeking, particularly in rats with a history of high drug-taking. Importantly, this treatment regimen had no effect on either circulating glucose or insulin. GLP-1RAs, then, appear strong candidates for the non-opioid prevention of relapse to opioids. Topics: Animals; Cues; Diabetes Mellitus, Type 2; Glucagon-Like Peptide 1; Glucagon-Like Peptide-1 Receptor; Glucose; Heroin; Humans; Hypoglycemic Agents; Insulin; Liraglutide; Rats; Recurrence | 2022 |
GLP-1 Agonist to Treat Obesity and Prevent Cardiovascular Disease: What Have We Achieved so Far?
To discuss evidence supporting the use of glucagon-like peptide 1 receptor agonists (GLP-1RA) to treat obesity and their role as a cardioprotective drug. Obesity is not just a hypertrophy of the adipose tissue because it may become dysfunctional and inflamed resulting in increased insulin resistance. Being overweight is associated with increased incidence of cardiovascular events and weight loss achieved through lifestyle changes lowers risk factors, but has no clear effect on cardiovascular outcomes. In contrast, treating obesity with GLP-1RA decreases cardiovascular risk and the possible mechanisms of cardioprotection achieved by this class of drugs are discussed. GLP-1RA were initially developed to treat type 2 diabetes patients, in whom the effects upon glycemia and, moreover, weight loss, especially with long-acting GLP-1RA, were evident. However, cardiovascular safety trials in type 2 diabetes patients, the majority presenting cardiovascular disease and excess weight, showed that GLP-1 receptor agonists were indeed capable of decreasing cardiovascular risk.. Type 2 diabetes treatment with GLP-1RA liraglutide and semaglutide paved way to a ground-breaking therapy specific for obesity, as shown with the SCALE 3 mg/day liraglutide program and the STEP 2.4 mg/week semaglutide program. A novel molecule with superior performance is tirzepatide, a GLP-1 and GIP (Gastric Inhibitory Peptide) receptor agonist and recent results from the SURPASS and SURMOUNT programs are briefly described. Liraglutide was approved without a CVOT (Cardiovascular Outcome Trial) because authorities accepted the results from the LEADER study, designed for superiority. The SELECT study with semaglutide will report results only in 2023 and tirzepatide is being tested in patients with diabetes in the SURPASS-CVOT. Clinical studies highlight that GLP-1RA to treat obesity, alongside their concomitant cardioprotective effects, have become a hallmark in clinical science. Topics: Cardiovascular Diseases; Clinical Trials as Topic; Diabetes Mellitus, Type 2; Glucagon-Like Peptide 1; Glucagon-Like Peptide-1 Receptor; Humans; Hypoglycemic Agents; Liraglutide; Obesity; Weight Loss | 2022 |
Tirzepatide, a dual GIP/GLP-1 receptor co-agonist for the treatment of type 2 diabetes with unmatched effectiveness regrading glycaemic control and body weight reduction.
Tirzepatide is the first dual GIP/GLP-1 receptor co-agonist approved for the treatment of type 2 diabetes in the USA, Europe, and the UAE. Tirzepatide is an acylated peptide engineered to activate the GIP and GLP-1 receptors, key mediators of insulin secretion that are also expressed in regions of the brain that regulate food intake. Five clinical trials in type 2-diabetic subjects (SURPASS 1-5) have shown that tirzepatide at 5-15 mg per week reduces both HbA Topics: Body Weight; Cardiovascular Diseases; Clinical Trials as Topic; Diabetes Mellitus, Type 2; Gastric Inhibitory Polypeptide; Glucagon-Like Peptide 1; Glucagon-Like Peptide-1 Receptor; Glycemic Control; Humans; Hypoglycemic Agents; Insulin; Meta-Analysis as Topic; Weight Loss | 2022 |
Incretin-based drugs as potential therapy for neurodegenerative diseases: current status and perspectives.
Alzheimer's disease (AD) and Parkinson's disease (PD) are the most frequent neurodegenerative disorders. Despite their pathophysiological and clinical differences, they share several mechanistic similarities at cellular and sub-cellular levels. The current treatments of AD and PD are only symptomatic, since many clinically-tested drugs failed to prevent or halt their progression. There is now evidence that type 2 diabetes mellitus is among the main risk factors for AD and PD and that the insulin resistance in the brain plays a crucial role in their neuropathological processes. Therefore, insulin nasal administration was suggested for the treatment of AD and PD, both in diabetic and non-diabetic patients. However, the adverse effects of chronic insulin prompted the research of alternative strategies, such as the novel antidiabetic drugs based on the incretin hormones glucagon-like protein-1 (GLP-1) and glucose-dependent insulinotropic Peptide (GIP). The rapid inactivation of these incretins by dipeptidyl-peptidase IV (DPP-IV) suggested the development of DPP-IV-resistant GLP-1 receptor agonists (GLP-1Ras), the recent dual GLP-1/GIP receptor agonists and the DPP-IV inhibitors (DPP-IVis). This review will first describe the experimental, pathophysiological and clinical approach for AD and PD treatment with insulin. Afterwards, the main pharmacologic properties of GLP-1Ras and of DPP-IVis will be discussed, detailing their ability to cross the BBB and get access to the brain for GLP-1Ras, and the novel strategies for BBB crossing as regards DPP-IVis. Emphasis will be placed on the main findings obtained from AD and PD experimental models about the neuroprotective effects of these drugs. For AD, the improvement of learning and memory exerted by incretin-based drugs correlated with reduction of chronic inflammation, brain Aβ plaque, tau hyperphosphorylation, protection of mitochondria, enhancement of energy utilisation. For PD, both GLP-1Ras and of DPP-IVis reversed the nigrostriatal dopaminergic cell loss progression, restored dopamine synthesis, exerted anti-inflammatory activity and improved motor functions. Finally, the encouraging results of the first clinical trials on AD and PD patients and the adverse effects of GLP-1Ras and DPP-IVis will be discussed, highlighting how the above-mentioned neuroprotective effects have a great potential to be translated into clinical settings and that the incretin-based approach represents novel promising strategy for the Topics: Diabetes Mellitus, Type 2; Dipeptidyl-Peptidase IV Inhibitors; Gastric Inhibitory Polypeptide; Glucagon-Like Peptide 1; Humans; Hypoglycemic Agents; Incretins; Insulin; Neurodegenerative Diseases; Neuroprotective Agents | 2022 |
Glucagon-like peptide 1 and fibroblast growth factor-21 in non-alcoholic steatohepatitis: An experimental to clinical perspective.
Non-alcoholic steatohepatitis (NASH) is a progressive form of Non-alcoholic fatty liver disease (NAFLD), which slowly progresses toward cirrhosis and finally leads to the development of hepatocellular carcinoma. Obesity, insulin resistance, type 2 diabetes mellitus and the metabolic syndrome are major risk factors contributing to NAFLD. Targeting these risk factors is a rational option for inhibiting NASH progression. In addition, NASH could be treated with therapies that target the metabolic abnormalities causing disease pathogenesis (such as de novo lipogenesis and insulin resistance) as well with medications targeting downstream processes such as cellular damage, apoptosis, inflammation, and fibrosis. Glucagon-like peptide (GLP-1), is an incretin hormone dysregulated in both experimental and clinical NASH, which triggers many signaling pathways including fibroblast growth factor (FGF) that augments NASH pathogenesis. Growing evidence indicates that GLP-1 in concert with FGF-21 plays crucial roles in the conservation of glucose and lipid homeostasis in metabolic disorders. In line, GLP-1 stimulation improves hepatic ballooning, steatosis, and fibrosis in NASH. A recent clinical trial on NASH patients showed that the upregulation of FGF-21 decreases liver fibrosis and hepatic steatosis, thus improving the pathogenesis of NASH. Hence, therapeutic targeting of the GLP-1/FGF axis could be therapeutically beneficial for the remission of NASH. This review outlines the significance of the GLP-1/FGF-21 axis in experimental and clinical NASH and highlights the activity of modulators targeting this axis as potential salutary agents for the treatment of NASH. Topics: Diabetes Mellitus, Type 2; Fibroblast Growth Factors; Glucagon-Like Peptide 1; Glucose; Humans; Incretins; Insulin Resistance; Lipids; Liver; Liver Cirrhosis; Non-alcoholic Fatty Liver Disease | 2022 |
Incretins as a Potential Treatment Option for Gestational Diabetes Mellitus.
Gestational diabetes mellitus (GDM) is a metabolic disease affecting an increasing number of pregnant women around the world. It is not only associated with numerous perinatal complications but also has long-term consequences impacting maternal health and fetal development. To prevent them, it is important to keep glucose levels under control. As much as 15-30% of GDM patients will require treatment with insulin, metformin, or glyburide. With that in mind, it is crucial to keep searching for novel and improved pharmacotherapies. Nowadays, there are ongoing studies investigating the use of other groups of drugs that have proven successful in the treatment of T2DM. Glucagon-like peptide-1 (GLP-1) receptor agonist and dipeptidyl peptidase-4 (DPP-4) inhibitor are among the drugs targeting the incretin system and are currently receiving significant attention. The aim of our review is to demonstrate the potential of these medications in treating GDM and preventing its later complications. It seems that both groups may be successful in the GDM management used alone or as an addition to better-known drugs, including metformin and glyburide. However, more clinical trials are needed to confirm their importance in GDM treatment and to demonstrate effective therapeutic strategies. Topics: Blood Glucose; Diabetes Mellitus, Type 2; Diabetes, Gestational; Dipeptidyl-Peptidase IV Inhibitors; Female; Glucagon-Like Peptide 1; Glyburide; Humans; Hypoglycemic Agents; Incretins; Metformin; Pregnancy | 2022 |
EVOO's Effects on Incretin Production: Is There a Rationale for a Combination in T2DM Therapy?
Type 2 diabetes mellitus (T2DM) is a serious public health concern as it is one of the most common chronic diseases worldwide due to social and economic developments that have led to unhealthy lifestyles, with a considerable impact both in terms of morbidity and mortality. The management of T2DM, before starting specific therapies, includes cornerstones such as healthy eating, regular exercise and weight loss. Strict adherence to the Mediterranean diet (MedDiet) has been related to an inverse association with the risk of T2DM onset, as well as an improvement in glycaemic control; in particular, thanks to the consumption of extra virgin olive oil (EVOO). Agonists of gut-derived glucagon-like peptide-1 (GLP-1), gastrointestinal hormones able to increase insulin secretion in response to hyperglycaemia (incretins), have been recently introduced in T2DM therapy, quickly entering the international guidelines. Recent studies have linked the action of EVOO in reducing postprandial glycaemia to the increase in GLP-1 and the reduction of its inactivating protease, dipeptidyl peptidase-4 (DPP-4). In this review, we explore observations regarding the pathophysiological basis of the existence of an enhanced effect between the action of EVOO and incretins and, consequently, try to understand whether there is a rationale for their use in combination for T2DM therapy. Topics: Blood Glucose; Diabetes Mellitus, Type 2; Dipeptidyl-Peptidase IV Inhibitors; Glucagon-Like Peptide 1; Humans; Hypoglycemic Agents; Incretins; Insulin Secretion | 2022 |
New Horizons: Emerging Antidiabetic Medications.
Over the past century, since the discovery of insulin, the therapeutic offer for diabetes has grown exponentially, in particular for type 2 diabetes (T2D). However, the drugs in the diabetes pipeline are even more promising because of their impressive antihyperglycemic effects coupled with remarkable weight loss. An ideal medication for T2D should target not only hyperglycemia but also insulin resistance and obesity. Glucagon-like peptide-1 receptor agonists (GLP-1 RAs) and the new class of GLP1 and gastric inhibitory polypeptide dual RAs counteract 2 of these metabolic defects of T2D, hyperglycemia and obesity, with stunning results that are similar to the effects of metabolic surgery. An important role of antidiabetic medications is to reduce the risk and improve the outcome of cardiovascular diseases, including coronary artery disease and heart failure with reduced or preserved ejection fraction, as well as diabetic nephropathy, as shown by SGLT2 inhibitors. This review summarizes the main drugs currently under development for the treatment of type 1 diabetes and T2D, highlighting their strengths and side effects. Topics: Diabetes Mellitus, Type 2; Gastric Inhibitory Polypeptide; Glucagon-Like Peptide 1; Glucagon-Like Peptide-1 Receptor; Humans; Hyperglycemia; Hypoglycemic Agents; Incretins; Obesity | 2022 |
Novel Therapies for Cardiometabolic Disease: Recent Findings in Studies with Hormone Peptide-Derived G Protein Coupled Receptor Agonists.
The increasing prevalence of obesity and type 2 diabetes (T2DM) is provoking an important socioeconomic burden mainly in the form of cardiovascular disease (CVD). One successful strategy is the so-called metabolic surgery whose beneficial effects are beyond dietary restrictions and weight loss. One key underlying mechanism behind this surgery is the cooperative improved action of the preproglucagon-derived hormones, glucagon, glucagon-like peptide-1 (GLP-1), and glucose-dependent insulinotropic polypeptide (GIP) which exert their functions through G protein-coupled receptors (GPCR). Great success has been reached with therapies based on the GLP-1 receptor monoagonism; therefore, a logical and rational approach is the use of the dual and triagonism of GCPC to achieve complete metabolic homeostasis. The present review describes novel findings regarding the complex biology of the preproglucagon-derived hormones, their signaling, and the drug development of their analogues, especially those acting as dual and triagonists. Moreover, the main investigations into animal models and ongoing clinical trials using these unimolecular dual and triagonists are included which have demonstrated their safety, efficacy, and beneficial effects on the CV system. These therapeutic strategies could greatly impact the treatment of CVD with unprecedented benefits which will be revealed in the next years. Topics: Animals; Cardiovascular Diseases; Diabetes Mellitus, Type 2; Gastric Inhibitory Polypeptide; Glucagon; Glucagon-Like Peptide 1; Glucagon-Like Peptide-1 Receptor; Glucose; Incretins; Peptides; Proglucagon | 2022 |
The Molecular Determinants of Glucagon-like Peptide Secretion by the Intestinal L cell.
The intestinal L cell secretes a diversity of biologically active hormones, most notably the glucagon-like peptides, GLP-1 and GLP-2. The highly successful introduction of GLP-1-based drugs into the clinic for the treatment of patients with type 2 diabetes and obesity, and of a GLP-2 analog for patients with short bowel syndrome, has led to the suggestion that stimulation of the endogenous secretion of these peptides may serve as a novel therapeutic approach in these conditions. Situated in the intestinal epithelium, the L cell demonstrates complex relationships with not only circulating, paracrine, and neural regulators, but also ingested nutrients and other factors in the lumen, most notably the microbiota. The integrated input from these numerous secretagogues results in a variety of temporal patterns in L cell secretion, ranging from minutes to 24 hours. This review combines the findings of traditional, physiological studies with those using newer molecular approaches to describe what is known and what remains to be elucidated after 5 decades of research on the intestinal L cell and its secreted peptides, GLP-1 and GLP-2. Topics: Diabetes Mellitus, Type 2; Enteroendocrine Cells; Glucagon; Glucagon-Like Peptide 1; Glucagon-Like Peptide 2; Glucagon-Like Peptides; Humans; Peptide Fragments; Peptides; Secretagogues | 2022 |
The potential role of lactulose pharmacotherapy in the treatment and prevention of diabetes.
The non-absorbable disaccharide lactulose is mostly used in the treatment of various gastrointestinal disorders such as chronic constipation and hepatic encephalopathy. The mechanism of action of lactulose remains unclear, but it elicits more than osmotic laxative effects. As a prebiotic, lactulose may act as a bifidogenic factor with positive effects in preventing and controlling diabetes. In this review, we summarized the current evidence for the effect of lactulose on gut metabolism and type 2 diabetes (T2D) prevention. Similar to acarbose, lactulose can also increase the abundance of the short-chain fatty acid (SCFA)-producing bacteria Topics: Acarbose; Anti-Inflammatory Agents; Bacteria; Bile Acids and Salts; Diabetes Mellitus, Type 2; Fatty Acids, Volatile; Glucagon-Like Peptide 1; Humans; Lactulose; Laxatives; Lipopolysaccharides; Peptides; Tyrosine | 2022 |
Diabetic Kidney Disease Back in Focus: Management Field Guide for Health Care Professionals in the 21st Century.
Chronic kidney disease due to diabetes, or diabetic kidney disease (DKD), is a worldwide leading cause of chronic kidney disease and kidney failure and an increasingly important global public health issue. It is associated with poor quality of life, high burden of chronic diseases, and increased risk of premature death. Until recently, people with DKD had limited therapeutic options. Treatments have focused largely on glycemic and blood pressure control and renin-angiotensin system blockade, leaving patients with significant residual risk for progression of DKD. The availability of newer classes of glucose-lowering agents, namely, sodium-glucose cotransporter 2 inhibitors and glucagon-like peptide 1 receptor agonists, has changed the therapeutic landscape for these patients. These therapies have offered unprecedented opportunities to reduce the risk for progression of kidney disease and the risk of death that have led to recent updates to clinical guidelines. As such, the American Diabetes Association, the Kidney Disease: Improving Global Outcomes, and the European Association for the Study of Diabetes now recommend the use of sodium-glucose cotransporter 2 inhibitors and glucagon-like peptide 1 receptor agonists for patients with DKD to provide both kidney and cardiovascular protective benefits. This review highlights the importance of early detection of DKD and summarizes the latest recommendations in the clinical guidelines on management of patients with DKD with hope of facilitating their uptake into everyday clinical practice. An integrated approach to patient care with a multidisciplinary focus can help achieve the necessary shift in clinical care of patients with DKD. Topics: Blood Glucose; Diabetes Mellitus, Type 2; Diabetic Nephropathies; Glucagon-Like Peptide 1; Health Personnel; Humans; Quality of Life; Renal Insufficiency, Chronic; Sodium | 2022 |
New strategies to improve clinical outcomes for diabetic kidney disease.
Diabetic kidney disease (DKD), the most common cause of kidney failure and end-stage kidney disease worldwide, will develop in almost half of all people with type 2 diabetes. With the incidence of type 2 diabetes continuing to increase, early detection and management of DKD is of great clinical importance.. This review provides a comprehensive clinical update for DKD in people with type 2 diabetes, with a special focus on new treatment modalities. The traditional strategies for prevention and treatment of DKD, i.e., glycemic control and blood pressure management, have only modest effects on minimizing glomerular filtration rate decline or progression to end-stage kidney disease. While cardiovascular outcome trials of SGLT-2i show a positive effect of SGLT-2i on several kidney disease-related endpoints, the effect of GLP-1 RA on kidney-disease endpoints other than reduced albuminuria remain to be established. Non-steroidal mineralocorticoid receptor antagonists also evoke cardiovascular and kidney protective effects.. With these new agents and the promise of additional agents under clinical development, clinicians will be more able to personalize treatment of DKD in patients with type 2 diabetes. Topics: Diabetes Mellitus, Type 2; Diabetic Nephropathies; Glucagon-Like Peptide 1; Humans; Kidney Failure, Chronic; Mineralocorticoid Receptor Antagonists | 2022 |
Systematic review and meta-analysis of head-to-head trials comparing sulfonylureas and low hypoglycaemic risk antidiabetic drugs.
Safety of sulfonylurea drugs in the treatment of Type 2 Diabetes is still under debate. The aim of this study was to compare the all-cause mortality and cardiovascular adverse events of sulfonylureas and drugs with a low risk for hypoglycaemia in adults with type 2 diabetes.. Systematic review and meta-analysis of randomised controlled trials.. MEDLINE (PubMed, OVID), Embase, Cochrane Central Register of Controlled Trials, CINAHL, WOS and Lilacs.. Randomised controlled head-to-head trials that compared sulfonylureas with active control with low hypoglycaemic potential in adults (≥ 18 years old) with type 2 diabetes published up to August 2015. The drug classes involved in the analysis were metformin, dipeptidyl peptidase-4 (DPP-4) inhibitors, sodium-glucose co-transporter-2 (SGLT-2) inhibitors and glucagon-like peptide-1 (GLP-1) receptor agonists.. The primary endpoint was all-cause mortality. The secondary endpoints were MACE, cardiovascular events and severe hypoglycaemia.. Two reviewers checked study eligibility, independently extracted data and assessed quality with disagreements resolved through discussion. We assessed the risk of bias of the included studies using the Cochrane risk of bias tool for randomized trials v2. Pooled odds ratios (ORs) were estimated by using fixed effects model. The study is registered on PROSPERO (26/05/2016 CRD42016038780).. Our final analysis comprised 31 studies (26,204 patients, 11,711 patients given sulfonylureas and 14,493 given comparator drugs). In comparison to drugs with low hypoglycaemic potential, sulfonylureas had higher odds for all-cause mortality (OR 1.32, 95% CI 1.00-1.75), MACE (OR 1.32, 95% CI 1.07-1.61), myocardial infarction (fatal and non-fatal) (OR 1.67, 95% CI 1.17-2.38) and hypoglycaemia (OR 5.24, 95% CI 4.20-6.55). Subsequent sensitivity analysis revealed differences in the effect of sulfonylureas, with an increased risk of all-cause mortality with glipizide but not the other molecules.. Our meta-analysis raises concern about the safety of SUs compared to alternative drugs involved in current analysis. Important differences may exist within the drug class, and glimepiride seems to have best safety profile. Topics: Adolescent; Adult; Diabetes Mellitus, Type 2; Dipeptidyl-Peptidase IV Inhibitors; Dipeptidyl-Peptidases and Tripeptidyl-Peptidases; Glipizide; Glucagon-Like Peptide 1; Glucose; Humans; Hypoglycemia; Hypoglycemic Agents; Metformin; Sodium; Sodium-Glucose Transporter 2 Inhibitors; Symporters | 2022 |
Anti-Inflammatory Effects of GLP-1R Activation in the Retina.
Glucagon-like peptide-1 (GLP-1) is an incretin hormone, mainly produced by enteroendocrine L cells, which participates in the regulation of glucose homeostasis, and in reduction in body weight by promoting satiety. Actions of GLP-1 are mediated by activation of its receptor GLP-1R, which is widely expressed in several tissues including the retina. The effects of GLP-1R activation are useful in the management of type 2 diabetes mellitus (T2DM). In addition, the activation of GLP-1R has anti-inflammatory effects in several organs, suggesting that it may be also useful in the treatment of inflammatory diseases. Inflammation is a common element in the pathogenesis of several ocular diseases, and the protective effects of treatment with GLP-1 emerged also in retinal diseases. In this review we highlight the anti-inflammatory effects of GLP-1R activation in the retina. Firstly, we summarized the pathogenic role of inflammation in ocular diseases. Then, we described the pleiotropic effects of GLP-1R activation on the cellular components of the retina which are mainly involved in the pathogenesis of inflammatory retinal diseases: the retinal ganglion cells, retinal pigment epithelial cells and endothelial cells. Topics: Anti-Inflammatory Agents; Diabetes Mellitus, Type 2; Endothelial Cells; Glucagon-Like Peptide 1; Glucagon-Like Peptide-1 Receptor; Glucose; Humans; Hypoglycemic Agents; Incretins; Inflammation; Retina; Retinal Diseases | 2022 |
Clinical perspectives on the use of the GIP/GLP-1 receptor agonist tirzepatide for the treatment of type-2 diabetes and obesity.
Topics: Diabetes Mellitus, Type 2; Glucagon-Like Peptide 1; Glucagon-Like Peptide-1 Receptor; Humans; Obesity | 2022 |
The efficacy and safety of dipeptidyl peptidase-4 inhibitors and glucagon-like peptide-1 agonists in pediatric patients with type 2 diabetes: a systematic review.
The incidence of type 2 diabetes mellitus (T2DM) in the pediatric population is increasing. There is a great need to develop more drugs for pediatric T2DM. Glucagon-like peptide-1 (GLP-1) agonists and dipeptidyl dipeptidase-4 (DPP-4) inhibitors have been approved for adults with T2DM and they might be effective in youths due to the similar pathogenic defects associated with T2DM. Here we aim to evaluate the efficacy and safety of GLP-1 agonists and DPP-4 inhibitors in pediatric patients with T2DM.. We performed a systematic review including trials comparing GLP-1 agonists and DPP-4 inhibitors against placebo in pediatric T2DM. This project was conducted based on the quality of reporting of meta-analyses (QUOROM) statement. Embase, PubMed, and Cochrane library were searched by two independent investigators for selecting relevant studies.. Five RCTs with a total sample size of 237 children were included. GLP-1 agonists showed superiority in glycemic improvement than placebo for pediatric T2DM. The advantage of DPP-4 inhibitors versus placebo for glycemic improvement is still unclear. GLP-1 agonists and DPP-4 inhibitors were well tolerated in pediatrics and further strictly designed trials are needed. Topics: Blood Glucose; Child; Diabetes Mellitus, Type 2; Dipeptidyl-Peptidase IV Inhibitors; Glucagon-Like Peptide 1; Humans; Hypoglycemic Agents | 2022 |
Network meta-analysis on the effects of finerenone versus SGLT2 inhibitors and GLP-1 receptor agonists on cardiovascular and renal outcomes in patients with type 2 diabetes mellitus and chronic kidney disease.
To evaluate the cardiovascular and renal benefits of finerenone, sodium-glucose cotransporter-2 inhibitors (SGLT2i) and glucagonlike peptide-1 receptor agonists (GLP-1 RA) in patients with Type 2 Diabetes Mellitus (T2DM) and chronic kidney disease (CKD) with network meta-analysis.. Systematic literature searches were conducted of PubMed, Cochrane Library, Web of Science, Medline and Embase covering January 1, 2000 to December 30, 2021. Randomized control trials (RCTs) comparing finerenone, SGLT-2i and GLP-1 RA in diabetics with CKD were selected. We performed a network meta-analysis to compare the two drugs and finerenone indirectly. Results were reported as risk ratio (RR) with corresponding 95% confidence interval (CI).. 18 RCTs involving 51,496 patients were included. Finerenone reduced the risk of major adverse cardiovascular events (MACE), renal outcome and hospitalization for heart failure (HHF) (RR [95% CI]; 0.88 [0.80-0.97], 0.86 [0.79-0.93], 0.79 [0.67,0.92], respectively). SGLT-2i were associated with reduced risks of MACE (RR [95% CI]; 0.84 [0.78-0.90]), renal outcome (RR [95% CI]; 0.67 [0.60-0.74], HHF (RR [95% CI]; 0.60 [0.53-0.68]), all-cause death (ACD) (RR [95% CI]; 0.89 [0.81-0.91]) and cardiovascular death (CVD) (RR [95% CI]; 0.86 [0.77-0.96]) compared to placebo. GLP-1 RA were associated with a lower risk of MACE (RR [95% CI]; 0.86 [0.78-0.94]). SGLT2i had significant effect in comparison to finerenone (finerenone vs SGLT2i: RR [95% CI]; 1.29 [1.13-1.47], 1.31 [1.07-1.61], respectively) and GLP-1 RA (GLP-1 RA vs SGLT2i: RR [95% CI]; 1.36 [1.16-1.59], 1.49 [1.18-1.89], respectively) in renal outcome and HHF.. In patients with T2DM and CKD, SGLT2i, GLP-1 RA and finerenone were comparable in MACE, ACD and CVD. SGLT2i significantly decreased the risk of renal events and HHF compared with finerenone and GLP-1 RA. Among GLP-1 RA, GLP-1 analogues showed significant effect in reducing cardiovascular events compared with exendin-4 analogues. Topics: Cardiovascular Diseases; Diabetes Mellitus, Type 2; Glucagon-Like Peptide 1; Glucagon-Like Peptide-1 Receptor; Humans; Hypoglycemic Agents; Network Meta-Analysis; Renal Insufficiency, Chronic; Sodium-Glucose Transporter 2 Inhibitors | 2022 |
Glucagon-like peptide-1 (GLP-1) receptor agonists and neuroinflammation: Implications for neurodegenerative disease treatment.
Chronic, excessive neuroinflammation is a key feature of neurodegenerative diseases such as Alzheimer's disease (AD) and Parkinson's disease (PD). However, neuroinflammatory pathways have yet to be effectively targeted in clinical treatments for such diseases. Interestingly, increased inflammation and neurodegenerative disease risk have been associated with type 2 diabetes mellitus (T2DM) and insulin resistance (IR), suggesting that treatments that mitigate T2DM pathology may be successful in treating neuroinflammatory and neurodegenerative pathology as well. Glucagon-like peptide-1 (GLP-1) is an incretin hormone that promotes healthy insulin signaling, regulates blood sugar levels, and suppresses appetite. Consequently, numerous GLP-1 receptor (GLP-1R) stimulating drugs have been developed and approved by the US Food and Drug Administration (FDA) and related global regulatory authorities for the treatment of T2DM. Furthermore, GLP-1R stimulating drugs have been associated with anti-inflammatory, neurotrophic, and neuroprotective properties in neurodegenerative disorder preclinical models, and hence hold promise for repurposing as a treatment for neurodegenerative diseases. In this review, we discuss incretin signaling, neuroinflammatory pathways, and the intersections between neuroinflammation, brain IR, and neurodegenerative diseases, with a focus on AD and PD. We additionally overview current FDA-approved incretin receptor stimulating drugs and agents in development, including unimolecular single, dual, and triple receptor agonists, and highlight those in clinical trials for neurodegenerative disease treatment. We propose that repurposing already-approved GLP-1R agonists for the treatment of neurodegenerative diseases may be a safe, efficacious, and cost-effective strategy for ameliorating AD and PD pathology by quelling neuroinflammation. Topics: Alzheimer Disease; Diabetes Mellitus, Type 2; Glucagon-Like Peptide 1; Glucagon-Like Peptide-1 Receptor; Humans; Incretins; Neurodegenerative Diseases; Neuroinflammatory Diseases; Parkinson Disease | 2022 |
Cardiorenal disease management in type 2 diabetes: An expert consensus.
The interplay between cardiovascular disease (CVD), chronic kidney disease (CKD) and type 2 diabetes (T2D) is well established. We aim at providing an evidence-based expert opinion regarding the prevention and treatment of both heart failure (HF) and renal complications in people with T2D.. ology: The consensus recommendations were developed by subject experts in endocrinology, cardiology, and nephrology. The criteria for consensus were set to statements with ≥80% of agreement among clinicians specialized in endocrinology, cardiology, and nephrology. Key expert opinions were formulated based on scientific evidence and clinical judgment.. Assessing the risk factors of CVD or CKD in people with diabetes and taking measures to prevent HF or kidney disease are essential. Known CVD or CKD among people with diabetes confers a very high risk for recurrent CVD. Metformin plus lifestyle modification should be the first-line therapy (unless contraindicated) for the management of T2D. Glucagon-like peptide 1 (GLP-1) agonists can be preferred in people with atherosclerotic cardiovascular disease (ASCVD) or with high-risk indicators, along with sodium-glucose cotransporter-2 inhibitors (SGLT2i), whereas SGLT2i are the first choice in HF and CKD. The GLP-1 agonists can be used in people with CKD if SGLT2i are not tolerated.. Current evidence suggests SGLT2i as preferred agents among people with T2D and HF, and for those with T2D and ASCVD. SGLT2i and GLP-1RA also lower CV outcomes in those with diabetes and ASCVD, and the treatment choice should depend on the patient profile. Topics: Atherosclerosis; Cardiovascular Diseases; Consensus; Diabetes Mellitus, Type 2; Disease Management; Glucagon-Like Peptide 1; Glucagon-Like Peptide-1 Receptor; Heart Failure; Humans; Hypertension, Renal; Hypoglycemic Agents; Renal Insufficiency, Chronic; Sodium-Glucose Transporter 2 Inhibitors | 2022 |
Impact of glucagon-like peptide 1 analogs on cognitive function among patients with type 2 diabetes mellitus: A systematic review and meta-analysis.
Diabetes is an independent risk factor for cognitive impairment. However, little is known about the neuroprotective effects of glucagon-like peptide 1 (GLP-1) analogs on type 2 diabetes mellitus (T2DM). Herein, we assessed the impact of GLP-1 analogs on the general cognitive functioning among patients with T2DM.. Relevant studies were retrieved from PubMed, Embase, Cochrane Central Register of Controlled Trials (CENTRAL), and ClinicalTrials.gov databases from their inception till June 30, 2022, without any language restrictions. For continuous variables, the mean and standard deviation (SD) were extracted. Considering the heterogeneity in general cognitive functioning assessments among the pooled studies, the standardized mean differences (SMDs) with corresponding 95% confidence intervals (CIs), were calculated.. Five studies including 7,732 individuals with T2DM were selected for the meta-analysis. The use of GLP-1 analogs exerted no significant effects on the general cognitive functioning in self-controlled studies (SMD 0.33, 95% CI -0.03 to 0.69). Subgroup analyses among the self-controlled studies based on age and history of cardio-cerebrovascular disease showed that GLP-1 analogs significantly improved the general cognitive functioning in T2DM patients younger than 65 years (SMD 0.69, 95% CI 0.31 to 1.08) or those without cardio-cerebrovascular diseases (SMD 0.69, 95% CI 0.31 to 1.08). Similarly, differences in the general cognitive functioning for GLP-1 analogs between treated and non-treated patients with T2DM were significant in subgroups with patients younger than 65 years (SMD 1.04, 95% CI 0.61 to 1.47) or those with no history of cardio-cerebrovascular diseases (SMD 1.04, 95% CI 0.61 to 1.47).. Limited evidence suggests that the use of GLP-1 analogs exerts no significant effects on general cognitive functioning but may be beneficial for patients with T2DM younger than 65 years or those without a history of cardio-cerebrovascular diseases. Further prospective clinical studies with large sample sizes are needed to validate these findings.. www.inplasy.com, identifier 202260015. Topics: Cognition; Diabetes Mellitus, Type 2; Glucagon-Like Peptide 1; Humans; Risk Factors | 2022 |
The importance of estradiol for body weight regulation in women.
Obesity in women of reproductive age has a number of adverse metabolic effects, including Type II Diabetes (T2D), dyslipidemia, and cardiovascular disease. It is associated with increased menstrual irregularity, ovulatory dysfunction, development of insulin resistance and infertility. In women, estradiol is not only critical for reproductive function, but they also control food intake and energy expenditure. Food intake is known to change during the menstrual cycle in humans. This change in food intake is largely mediated by estradiol, which acts directly upon anorexigenic and orexigenic neurons, largely in the hypothalamus. Estradiol also acts indirectly with peripheral mediators such as glucagon like peptide-1 (GLP-1). Like estradiol, GLP-1 acts on receptors at the hypothalamus. This review describes the physiological and pathophysiological mechanisms governing the actions of estradiol during the menstrual cycle on food intake and energy expenditure and how estradiol acts with other weight-controlling molecules such as GLP-1. GLP-1 analogs have proven to be effective both to manage obesity and T2D in women. This review also highlights the relationship between steroid hormones and women's mental health. It explains how a decline or imbalance in estradiol levels affects insulin sensitivity in the brain. This can cause cerebral insulin resistance, which contributes to the development of conditions such as Parkinson's or Alzheimer's disease. The proper use of both estradiol and GLP-1 analogs can help to manage obesity and preserve an optimal mental health in women by reducing the mechanisms that trigger neurodegenerative disorders. Topics: Diabetes Mellitus, Type 2; Drug-Related Side Effects and Adverse Reactions; Estradiol; Female; Glucagon-Like Peptide 1; Humans; Insulin Resistance; Obesity | 2022 |
Transitioning to GLP-1 RAs and SGLT2 Inhibitors as the First Choice for Managing Cardiometabolic Risk in Type 2 Diabetes.
This forward-looking review summarizes existing evidence from cardiovascular outcome trials on cardiometabolic risk-reduction in type 2 diabetes (T2DM) management, with attention to updating and personalizing recommendations from recent diabetes practice guidelines issued by cardiology societies.. T2DM management has shifted towards cardiometabolic outcome improvement rather than purely glycemic control. According to large clinical trials, sodium-glucose cotransporter-2 inhibitors showed robust results in reducing heart failure (HF) hospitalization and chronic kidney disease (CKD) progression, while glucagon-like peptide-1 receptor agonists demonstrated the largest effects on HbA1c reduction, weight loss, and atherosclerotic cardiovascular disease outcomes prevention, including stroke. Considering the distinct features of these new cardiometabolic agents, initial selection of therapy should be targeted to each individual patient, with consideration of combination therapy for the highest risk patients. Moreover, future studies should investigate the addition of obesity-predominant risk, in conjunction with coronary artery disease, stroke, CKD, and HF, as a new influential indicator for choosing the optimal cardiometabolic agent. Topics: Cardiovascular Diseases; Diabetes Mellitus, Type 2; Glucagon-Like Peptide 1; Glucagon-Like Peptide-1 Receptor; Humans; Hypoglycemic Agents; Renal Insufficiency, Chronic; Sodium-Glucose Transporter 2 Inhibitors; Stroke | 2022 |
Treatment of HFpEF beyond the SGLT2-Is: Does the Addition of GLP-1 RA Improve Cardiometabolic Risk and Outcomes in Diabetic Patients?
Heart failure with preserved ejection fraction (HFpEF) is a common clinical syndrome frequently seen in elderly patients, the incidence of which is steadily increasing due to an ageing population and the increasing incidence of diseases, such as diabetes, hypertension, obesity, chronic renal failure, and so on. It is a multifactorial disease with different phenotypic aspects that share left ventricular diastolic dysfunction, and is the cause of about 50% of hospitalizations for heart failure in the Western world. Due to the complexity of the disease, no specific therapies have been identified for a long time. Sodium-Glucose Co-Transporter 2 Inhibitors (SGLT2-Is) and Glucagon-Like Peptide Receptor Agonists (GLP-1 RAs) are antidiabetic drugs that have been shown to positively affect heart and kidney diseases. For SGLT2-Is, there are precise data on their potential benefits in heart failure with reduced ejection fraction (HFrEF) as well as in HFpEF; however, insufficient evidence is available for GLP-1 RAs. This review addresses the current knowledge on the cardiac effects and potential benefits of combined therapy with SGLT2-Is and GLP-1RAs in patients with HFpEF. Topics: Aged; Diabetes Mellitus; Diabetes Mellitus, Type 2; Glucagon-Like Peptide 1; Heart Failure; Humans; Sodium-Glucose Transporter 2 Inhibitors; Stroke Volume | 2022 |
Tirzepatide: A Systematic Update.
Tirzepatide is a new molecule capable of controlling glucose blood levels by combining the dual agonism of Glucose-Dependent Insulinotropic Polypeptide (GIP) and Glucagon-Like Peptide-1 (GLP-1) receptors. GIP and GLP1 are incretin hormones: they are released in the intestine in response to nutrient intake and stimulate pancreatic beta cell activity secreting insulin. GIP and GLP1 also have other metabolic functions. GLP1, in particular, reduces food intake and delays gastric emptying. Moreover, Tirzepatide has been shown to improve blood pressure and to reduce Low-Density Lipoprotein (LDL) cholesterol and triglycerides. Tirzepatide efficacy and safety were assessed in a phase III SURPASS 1-5 clinical trial program. Recently, the Food and Drug Administration approved Tirzepatide subcutaneous injections as monotherapy or combination therapy, with diet and physical exercise, to achieve better glycemic blood levels in patients with diabetes. Other clinical trials are currently underway to evaluate its use in other diseases. The scientific interest toward this novel, first-in-class medication is rapidly increasing. In this comprehensive and systematic review, we summarize the main results of the clinical trials investigating Tirzepatide and the currently available meta-analyses, emphasizing novel insights into its adoption in clinical practice for diabetes and its future potential applications in cardiovascular medicine. Topics: Diabetes Mellitus, Type 2; Gastric Inhibitory Polypeptide; Glucagon-Like Peptide 1; Glucagon-Like Peptide-1 Receptor; Glucose; Humans; Hypoglycemic Agents; Incretins | 2022 |
Cardiovascular outcomes with glucagon-like peptide 1 agonists and sodium-glucose cotransporter 2 inhibitors in patients with type 2 diabetes: A meta-analysis.
According to available research, there have been no head-to-head studies comparing the effect of glucagon-like peptide 1 (GLP-1) agonists and sodium-glucose cotransporter 2 (SGLT-2) inhibitors on cardiovascular outcomes among patients with type 2 diabetes not reaching glycemic goal with metformin.. Relevant studies were identified through electronic searches of PubMed and EMBASE published up to January 15, 2020. Efficacy outcomes of interest included the composite of cardiovascular death, non-fatal myocardial infarction, or non-fatal stroke, its individual components, all-cause death, and hospitalization for heart failure (HF). Safety outcomes included all suggested side effects of both agents previously reported.. Eleven studies, including 94,727 patients were used for the analysis. The risk of composite end point was significantly lower in both groups compared to the control group (hazard ratio [HR] 0.88, 95% confidence interval [CI] 0.85-0.92, p < 0.001). The risk of hospitalization for HF was significantly lower in both groups but the magnitude of the effect was more pronounced in the SGLT-2 inhibitors group (HR 0.68, 95% CI 0.60-0.76, p < 0.001) than the GLP-1 agonists group (HR 0.92, 95% CI 0.84-0.99, p = 0.03). Patients treated with GLP-1 agonists discontinued trial medications more frequently compared to conventionally treated patients because of serious side effects.. Both GLP-1 agonists and SGLT-2 inhibitors showed comparable cardiovascular outcomes in patients with type 2 diabetes. However, the SGLT-2 inhibitors were associated with more pronounced reduction of hospitalization for HF and lower risk of treatment discontinuation than GLP-1 agonists. Topics: Blood Glucose; Cardiovascular Diseases; Diabetes Mellitus, Type 2; Glucagon-Like Peptide 1; Heart Failure; Humans; Hypoglycemic Agents; Sodium-Glucose Transporter 2 Inhibitors | 2022 |
Non-peptide agonists and positive allosteric modulators of glucagon-like peptide-1 receptors: Alternative approaches for treatment of Type 2 diabetes.
Glucagon-like peptide-1 (GLP-1) receptors belong to the pharmaceutically important Class B family of GPCRs and are involved in many biologically significant signalling pathways. Its incretin peptide ligand GLP-1 analogues are effective treatments for Type 2 diabetes. Although developing non-peptide low MW drugs targeting GLP-1 receptors remains elusive, considerable progress has been made in discovering non-peptide agonists and positive allosteric modulators (PAMs) of GLP-1 receptors with demonstrated efficacy. Many of these compounds induce biased signalling in GLP-1 receptor-mediated functional pathways. High-quality structures of GLP-1 receptors in both inactive and active states have been reported, revealing detailed molecular interactions between GLP-1 receptors and non-peptide agonists or PAMs. These progresses raise the exciting possibility of developing non-peptide drugs of GLP-1 receptors as alternative treatments for Type 2 diabetes. The insight into the interactions between the receptor and the non-peptide ligand is also useful for developing non-peptide ligands targeting other Class B GPCRs. LINKED ARTICLES: This article is part of a themed issue on GLP1 receptor ligands (BJP 75th Anniversary). To view the other articles in this section visit http://onlinelibrary.wiley.com/doi/10.1111/bph.v179.4/issuetoc. Topics: Diabetes Mellitus, Type 2; Glucagon-Like Peptide 1; Glucagon-Like Peptide-1 Receptor; Humans; Ligands; Peptides | 2022 |
The effects of glucagon like peptide-1 (GLP-1) on cardiac remodeling: exploring the role of medication and physiological modulation after metabolic surgery.
Obesity and associated comorbidities reach epidemic proportions nowadays. Several treatment strategies exist, but bariatric surgery has the only longstanding effects. Since a few years, there is increasing interest in the effects of gastro-intestinal hormones, in particular Glucagon-Like Peptide-1 (GLP-1) on the remission of Type 2 Diabetes (T2DM) and its effects on cardiac cardiovascular morbidity, cardiac remodeling, and mortality. In the past years several high quality multicenter randomized controlled trials were developed to assess the effects of GLP-1 receptor agonist therapy on cardiovascular morbidity and mortality. Most of the trials were designed and powered as non-inferiority trials to demonstrate cardiovascular safety. Most of these trials show a reduction in cardiovascular morbidity in patients with T2DM. Some follow-up studies indicate potential beneficial effects of GLP-1 receptor agonists on cardiovascular function in patients with heart failure, however the results are contradictory, and we need long-term studies to make firm conclusions about the pleiotropic properties of incretin-based therapies. However, it seems that GLP-1 receptor agonists have different effects than the increased GLP-1 production after bariatric surgery on cardiovascular remodeling. One of the hypotheses is that the blood concentrations of GLP-1 receptor agonists are three times higher compared to GLP-1 increase after bariatric and metabolic surgery. The purpose of this narrative review is to summarize the effects of GLP-1 on cardiovascular morbidity, mortality and remodeling due to medication but also due to bariatric and metabolic surgery. The second objective is to explain the possible differences in effects of GLP-1 agonists and bariatric and metabolic surgery. Topics: Bariatric Surgery; Cardiovascular Diseases; Diabetes Mellitus, Type 2; Glucagon-Like Peptide 1; Glucagon-Like Peptide-1 Receptor; Humans; Multicenter Studies as Topic; Obesity; Ventricular Remodeling | 2022 |
Glucagon-like peptide-1 (GLP-1) receptor agonists and their cardiovascular benefits-The role of the GLP-1 receptor.
Cardiovascular outcome trials revealed cardiovascular benefits for type 2 diabetes mellitus patients when treated with long-acting glucagon-like peptide-1 (GLP-1) receptor agonists. In the last decade, major advances were made characterising the physiological effects of GLP-1 and its action on numerous targets including brain, liver, kidney, heart and blood vessels. However, the effects of GLP-1 and receptor agonists, and the GLP-1 receptor on the cardiovascular system have not been fully elucidated. We compare results from cardiovascular outcome trials of GLP-1 receptor agonists and review pleiotropic clinical and preclinical data concerning cardiovascular protection beyond glycaemic control. We address current knowledge on GLP-1 and receptor agonist actions on the heart, vasculature, inflammatory cells and platelets, and discuss evidence for GLP-1 receptor-dependent versus independent effects secondary of GLP-1 metabolites. We conclude that the favourable cardiovascular profile of GLP-1 receptor agonists might expand their therapeutic use for treating cardiovascular disease even in non-diabetic populations. LINKED ARTICLES: This article is part of a themed issue on GLP1 receptor ligands (BJP 75th Anniversary). To view the other articles in this section visit http://onlinelibrary.wiley.com/doi/10.1111/bph.v179.4/issuetoc. Topics: Cardiovascular Diseases; Cardiovascular System; Diabetes Mellitus, Type 2; Glucagon-Like Peptide 1; Glucagon-Like Peptide-1 Receptor; Humans; Hypoglycemic Agents | 2022 |
Metabolic responses and benefits of glucagon-like peptide-1 (GLP-1) receptor ligands.
Glucagon-like peptide-1 (GLP-1) is an incretin hormone that has undergone a revolutionary turnaround from discovery to clinically approved therapeutic. Rapid progress in drug design and formulation has led from initial development of short- and long-acting drugs suitable for daily or weekly parenteral administration, respectively, through to the most recent approval of an orally active GLP-1 agent. The current review outlines the biological action profile of GLP-1 including the various beneficial metabolic responses in pancreatic and extra-pancreatic tissues, including the gastrointestinal tract, liver, bone and kidney as well as the reproductive cardiovascular and CNS. We then briefly consider clinically approved GLP-1 receptor ligands and recent advances in this field. Given the sustained evolution in the area of GLP-1 drug development and excellent safety profile, as well as the plethora of metabolic benefits, clinical approval for use in diseases beyond diabetes and obesity is very much conceivable. LINKED ARTICLES: This article is part of a themed issue on GLP1 receptor ligands (BJP 75th Anniversary). To view the other articles in this section visit http://onlinelibrary.wiley.com/doi/10.1111/bph.v179.4/issuetoc. Topics: Diabetes Mellitus, Type 2; Glucagon-Like Peptide 1; Glucagon-Like Peptide-1 Receptor; Heart; Humans; Hypoglycemic Agents; Ligands; Obesity | 2022 |
The therapeutic potential of GLP-1 receptor biased agonism.
Glucagon-like peptide-1 (GLP-1) receptor agonists are effective treatments for type 2 diabetes as they stimulate insulin release and promote weight loss through appetite suppression. Their main side effect is nausea. All approved GLP-1 agonists are full agonists across multiple signalling pathways. However, selective engagement with specific intracellular effectors, or biased agonism, has been touted as a means to improve GLP-1 agonists therapeutic efficacy. In this review, I critically examine how GLP-1 receptor-mediated intracellular signalling is linked to physiological responses and discuss the implications of recent studies investigating the metabolic effects of biased GLP-1 agonists. Overall, there is little conclusive evidence that beneficial and adverse effects of GLP-1 agonists are attributable to distinct, nonoverlapping signalling pathways. Instead, G protein-biased GLP-1 agonists appear to achieve enhanced anti-hyperglycaemic efficacy by avoiding GLP-1 receptor desensitisation and downregulation, partly via reduced β-arrestin recruitment. This effect seemingly applies more to insulin release than to appetite regulation and nausea, possible reasons for which are discussed. At present, most evidence derives from cellular and animal studies, and more human data are required to determine whether this approach represents a genuine therapeutic advance. LINKED ARTICLES: This article is part of a themed issue on GLP1 receptor ligands (BJP 75th Anniversary). To view the other articles in this section visit http://onlinelibrary.wiley.com/doi/10.1111/bph.v179.4/issuetoc. Topics: Animals; Diabetes Mellitus, Type 2; Glucagon-Like Peptide 1; Glucagon-Like Peptide-1 Receptor; Insulin; Nausea | 2022 |
Protective properties of GLP-1 and associated peptide hormones in neurodegenerative disorders.
Type 2 diabetes mellitus and the associated desensitisation of insulin signalling has been identified as a risk factor for progressive neurodegenerative disorders such as Alzheimer's disease, Parkinson's disease and others. Glucagon-like peptide 1 (GLP-1) is a hormone that has growth factor-like and neuroprotective properties. Several clinical trials have been conducted, testing GLP-1 receptor agonists in patients with Alzheimer's disease, Parkinson's disease or diabetes-induced memory impairments. The trials showed clear improvements in Alzheimer's disease, Parkinson's disease and diabetic patients. Glucose-dependent insulinotropic polypeptide/gastric inhibitory peptide (GIP) is the 'sister' incretin hormone of GLP-1. GIP analogues have shown neuroprotective effects in animal models of disease and can improve on the effects of GLP-1. Novel dual GLP-1/GIP receptor agonists have been developed that can enter the brain at an enhanced rate. The improved neuroprotective effects of these drugs suggest that they are superior to single GLP-1 receptor agonists and could provide disease-modifying care for Alzheimer's disease and Parkinson's disease patients. LINKED ARTICLES: This article is part of a themed issue on GLP1 receptor ligands (BJP 75th Anniversary). To view the other articles in this section visit http://onlinelibrary.wiley.com/doi/10.1111/bph.v179.4/issuetoc. Topics: Alzheimer Disease; Animals; Diabetes Mellitus, Type 2; Gastric Inhibitory Polypeptide; Glucagon-Like Peptide 1; Glucagon-Like Peptide-1 Receptor; Humans; Insulin; Neuroprotective Agents; Parkinson Disease | 2022 |
Evaluation of GLP-1 Receptor Agonists in Combination With Multiple Daily Insulin Injections for Type 2 Diabetes.
To assess the available literature evaluating the efficacy and safety of glucagon-like peptide-1 receptor agonists (GLP-1 RAs) with multiple daily insulin injections (MDII).. A literature search of MEDLINE and Embase was performed (2004 to May 2020) using the following search terms: glucagon-like 1 receptor agonist, liraglutide, albiglutide, dulaglutide, exenatide, semaglutide, diabetes mellitus, and prandial insulin or bolus insulin. Additional references were obtained from cross-referencing the bibliographies of selected articles.. All information obtained from the searches were reviewed. All relevant trials are included in this review.. Eight studies met criteria for inclusion. The addition of a GLP-1 RA to multiple daily insulin injections was associated with a reduction in A1c in 7 out of 8 studies, and weight loss in 5 studies. In studies that allowed insulin adjustment after the addition of GLP-1 RA, the average total daily insulin dose was reduced in 3 studies. When evaluated, hypoglycemia frequency or other adverse events were not increased when GLP-1 RAs were added to MDII.. Guidelines do not offer recommendations regarding the use of GLP-1 RAs in combination with MDII regimens. This review evaluates current studies demonstrating efficacy and safety considerations of this combination.. While some studies did demonstrate an improvement in A1c and reduction in insulin doses without increased hypoglycemia, larger randomized controlled trials are needed to adequately assess the benefit and safety of GLP-1 RAs in combination with MDII. Topics: Diabetes Mellitus, Type 2; Glucagon-Like Peptide 1; Glucagon-Like Peptide-1 Receptor; Glycated Hemoglobin; Humans; Hypoglycemia; Hypoglycemic Agents; Insulin | 2022 |
Challenges in Implementing Evidence Based Cross-Disciplinary Therapies: Are Cardiovascular Specialists Ready to Claim SGLT-2 Inhibitors and GLP-1 Analogs?
Cardiovascular disease is a leading cause of morbidity, mortality and financial burden to the United States health system. A change in focus towards preventive medicine along with advances in pharmacologic and invasive therapies, has led to improved cardiac death rates. These benefits however, come with increased prevalence of heart failure and soaring readmission rates. Reducing burden of hospitalizations has therefore, been a focus of clinicians and researchers over the years. An improvement in clinical outcomes has been demonstrated in multiple trials investigating HF therapies, however, execution of guideline recommendations has been trailing. Over the past decade, 2 classes of hypoglycemic agents, the glucagon-like peptide-1 (GLP-1) receptor agonists and the sodium-glucose cotransporter 2 (SGLT-2) inhibitors have been recognized for their cardiovascular morbidity and mortality benefits. Studies have shown that there has been a steady increase in prescription rates of these medications, however, overall usage remains quite low. Various patient, physician and system-based factors have been identified that cause barriers to translation of trial data to real-world clinical outcomes. A strategy focused on physician and patient education, quality improvement, multi-disciplinary team approach, and patient centered care is essential to meet treatment goals. Topics: Cardiovascular Diseases; Diabetes Mellitus, Type 2; Glucagon-Like Peptide 1; Glucagon-Like Peptide-1 Receptor; Humans; Hypoglycemic Agents; Sodium-Glucose Transporter 2 Inhibitors | 2022 |
Meta-analysis evaluating the risk of respiratory tract infections and acute respiratory distress syndrome with glucagon-like peptide-1 receptor agonists in cardiovascular outcome trials: Useful implications for the COVID-19 pandemic.
Patients with type 2 diabetes mellitus (T2DM) are at increased risk for severe coronavirus disease 2019 (COVID-19) and related mortality. Glucagon-like peptide-1 receptor agonists (GLP-1-RAs) have significant cardiovascular and renal benefits for patients with T2DM and related comorbidities. Their anti-inflammatory properties could be beneficial in these patients. This work provides less-biased estimates regarding the risk for respiratory tract infections and acute respiratory distress syndrome by performing the first significant meta-analysis of cardiovascular outcome trials in the literature. Notably, GLP-1-RAs do not seem to increase the risk for respiratory tract infection, pneumonia, or acute respiratory distress syndrome in patients with T2DM and cardiovascular comorbidities. Topics: Cardiovascular Diseases; COVID-19; Diabetes Mellitus, Type 2; Glucagon-Like Peptide 1; Glucagon-Like Peptide-1 Receptor; Humans; Hypoglycemic Agents; Pandemics; Respiratory Distress Syndrome | 2022 |
Altered islet prohormone processing: a cause or consequence of diabetes?
Peptide hormones are first produced as larger precursor prohormones that require endoproteolytic cleavage to liberate the mature hormones. A structurally conserved but functionally distinct family of nine prohormone convertase enzymes (PCs) are responsible for cleavage of protein precursors, of which PC1/3 and PC2 are known to be exclusive to neuroendocrine cells and responsible for prohormone cleavage. Differential expression of PCs within tissues defines prohormone processing; whereas glucagon is the major product liberated from proglucagon via PC2 in pancreatic α-cells, proglucagon is preferentially processed by PC1/3 in intestinal L cells to produce glucagon-like peptides 1 and 2 (GLP-1, GLP-2). Beyond our understanding of processing of islet prohormones in healthy islets, there is convincing evidence that proinsulin, pro-islet amyloid polypeptide (proIAPP), and proglucagon processing is altered during prediabetes and diabetes. There is predictive value of elevated circulating proinsulin or proinsulin-to-C-peptide ratio for progression to type 2 diabetes, and elevated proinsulin or proinsulin-to-C-peptide ratio is predictive for development of type 1 diabetes in at-risk groups. After onset of diabetes, patients have elevated circulating proinsulin and proIAPP, and proinsulin may be an autoantigen in type 1 diabetes. Furthermore, preclinical studies reveal that α-cells have altered proglucagon processing during diabetes, leading to increased GLP-1 production. We conclude that despite strong associative data, current evidence is inconclusive on the potential causal role of impaired prohormone processing in diabetes and suggest that future work should focus on resolving the question of whether altered prohormone processing is a causal driver or merely a consequence of diabetes pathology. Topics: Animals; Diabetes Mellitus, Type 2; Glucagon; Glucagon-Like Peptide 1; Humans; Proglucagon; Proinsulin; Protein Precursors | 2022 |
Glucagon-like peptide-1 in diabetes care: Can glycaemic control be achieved without nausea and vomiting?
Topics: Diabetes Mellitus, Type 2; Emetics; Gastric Inhibitory Polypeptide; Glucagon-Like Peptide 1; Glucagon-Like Peptide-1 Receptor; Glycemic Control; Humans; Nausea; Vomiting | 2022 |
Anti-Diabetic Drugs GLP-1 Agonists and DPP-4 Inhibitors may Represent Potential Therapeutic Approaches for COVID-19.
The fast spread of coronavirus 2019 (COVID-19) calls for immediate action to counter the associated significant loss of human life and deep economic impact. Certain patient populations like those with obesity and diabetes are at higher risk for acquiring severe COVID-19 disease and have a higher risk of COVID-19 associated mortality. In the absence of an effective and safe vaccine, the only immediate promising approach is to repurpose an existing approved drug. Several drugs have been proposed and tested as adjunctive therapy for COVID-19. Among these drugs are the glucagon-like peptide-1 (GLP-1) 2 agonists and the dipeptidylpeptidase-4 (DPP-4) inhibitors. Beyond their glucose-lowering effects, these drugs have several pleiotropic protective properties, which include cardioprotective effects, anti-inflammatory and immunomodulatory activities, antifibrotic effects, antithrombotic effects, and vascular endothelial protective properties. This narrative review discusses these protective properties and addresses their scientific plausibility for their potential use as adjunctive therapy for COVID-19 disease. Topics: COVID-19 Drug Treatment; Diabetes Mellitus, Type 2; Dipeptidyl-Peptidase IV Inhibitors; Glucagon-Like Peptide 1; Humans; Hypoglycemic Agents | 2022 |
The effects of glucagon-like peptide (GLP)-1 receptor agonists on weight and glycaemic control in Prader-Willi syndrome: A systematic review.
The mainstay management of hyperphagia and obesity in Prader-Willi syndrome (PWS) relies on dietary restrictions, strict supervision and behavioural modifications, which can be stressful for the patient and caregiver. There is no established pharmacological strategy to manage this aspect of PWS. Theoretically, glucagon-like peptide-1 (GLP-1) receptor agonists (GLP1-RA) used in patients with obesity and type 2 diabetes mellitus (T2DM) may be efficacious in weight and glycaemic control of PWS patients. We conducted a systematic review of the literature to summarize the evidence on the use of GLP1-RA in PWS patients.. Primary studies were searched in major databases using key concepts 'Prader-Willi syndrome' and 'GLP1 receptor agonist' and outcomes, 'weight control OR glycaemic control OR appetite regulation'.. Ten studies included, summarizing GLP1-RA use in 23 PWS patients (age, 13-37 years), who had used either exenatide (n = 14) or liraglutide (n = 9) over a duration of 14 weeks to 4 years. Sixteen (70%) of these patients had T2DM. Ten patients experienced improvement in body mass index, ranging from 1.5 to 16.0 kg/m. GLP1-RA appears safe in PWS patients and may have potential benefits for weight, glycaemic and appetite control. Nonetheless, we also highlight a significant gap in the literature on the lack of well-designed studies in this area, which limits the recommendation of GLP1-RA use in PWS patients at present. Topics: Adolescent; Adult; Diabetes Mellitus, Type 2; Glucagon-Like Peptide 1; Glucagon-Like Peptide-1 Receptor; Glycemic Control; Humans; Liraglutide; Prader-Willi Syndrome; Young Adult | 2022 |
Novel approaches to pharmacological management of type 2 diabetes in Japan.
Newly developed anti-diabetic medications have had multiple activities, beyond a blood glucose-lowering effect. Current drugs for treating type 2 diabetes mellitus (T2DM) are based on the use of gastrointestinal hormones. Representative incretin preparations, such as those with glucagon-like peptide (GLP)-1 or gastric inhibitory polypeptide (GIP) activity, aim to provide new means of controlling blood glucose levels, body weight, and lipid metabolism.. In this manuscript, the pathophysiology of T2DM and the activities and characteristics of novel diabetic drugs are reviewed in the context of the Japanese population. This review also highlights the need for novel medicines to overcome the accompanying challenges. Finally, the author provides the reader with their expert perspectives.. The incidence of T2DM has been increasing in the aging of Japanese society. In older people, medical development should focus on safety, easier self-administration, and the relief of caregiver burden in terms of continuous administration. In the young, the focus should be on effectiveness, with a particular emphasis on the protection of organs, increasing the ease of adherence, and safety. Novel medicines will need to push the envelope in these areas. Topics: Blood Glucose; Diabetes Mellitus, Type 2; Gastric Inhibitory Polypeptide; Glucagon-Like Peptide 1; Humans; Incretins; Insulin; Japan | 2021 |
Renoprotective Effects of Incretin-Based Therapy in Diabetes Mellitus.
Glucagon-like peptide-1 (GLP-1) receptor agonists are recently discovered antidiabetic drugs with potent hypoglycemic effects. Among different mechanisms of activity, these compounds were shown to reduce blood glucose by suppression of glucagon secretion and stimulation of glucose-dependent insulin secretion. These antidiabetic agents have a minor risk of hypoglycemia and have been suggested as a second-line therapy to be added to metformin treatment to further optimize glycemic control in diabetes. More recently, scientific evidence suggests that GLP-1 receptor agonists may particularly afford protection from diabetic nephropathy through modulation of the molecular pathways involved in renal impairment and so improve renal function. This additional benefit adds further weight for these compounds to become promising drugs not only for glycemic control but also to prevent diabetic complications. In this review, we have updated evidence on the beneficial effects of GLP-1 receptor agonists on diabetic nephropathy and detailed the underlying pathophysiological mechanisms. Topics: Diabetes Mellitus, Type 2; Diabetic Nephropathies; Dipeptidyl-Peptidase IV Inhibitors; Glucagon-Like Peptide 1; Glucagon-Like Peptide-1 Receptor; Humans; Incretins; Insulin Secretion | 2021 |
GLP-1 Receptor Agonists: Beyond Their Pancreatic Effects.
Glucagon like peptide-1 (GLP-1) is an incretin secretory molecule. GLP-1 receptor agonists (GLP-1RAs) are widely used in the treatment of type 2 diabetes (T2DM) due to their attributes such as body weight loss, protection of islet β cells, promotion of islet β cell proliferation and minimal side effects. Studies have found that GLP-1R is widely distributed on pancreatic and other tissues and has multiple biological effects, such as reducing neuroinflammation, promoting nerve growth, improving heart function, suppressing appetite, delaying gastric emptying, regulating blood lipid metabolism and reducing fat deposition. Moreover, GLP-1RAs have neuroprotective, anti-infectious, cardiovascular protective, and metabolic regulatory effects, exhibiting good application prospects. Growing attention has been paid to the relationship between GLP-1RAs and tumorigenesis, development and prognosis in patient with T2DM. Here, we reviewed the therapeutic effects and possible mechanisms of action of GLP-1RAs in the nervous, cardiovascular, and endocrine systems and their correlation with metabolism, tumours and other diseases. Topics: Animals; Cardiovascular System; Diabetes Mellitus, Type 2; Glucagon-Like Peptide 1; Glucagon-Like Peptide-1 Receptor; Humans; Hypoglycemic Agents; Pancreas | 2021 |
The Role of the α Cell in the Pathogenesis of Diabetes: A World beyond the Mirror.
Type 2 Diabetes Mellitus (T2DM) is one of the most prevalent chronic metabolic disorders, and insulin has been placed at the epicentre of its pathophysiological basis. However, the involvement of impaired alpha (α) cell function has been recognized as playing an essential role in several diseases, since hyperglucagonemia has been evidenced in both Type 1 and T2DM. This phenomenon has been attributed to intra-islet defects, like modifications in pancreatic α cell mass or dysfunction in glucagon's secretion. Emerging evidence has shown that chronic hyperglycaemia provokes changes in the Langerhans' islets cytoarchitecture, including α cell hyperplasia, pancreatic beta (β) cell dedifferentiation into glucagon-positive producing cells, and loss of paracrine and endocrine regulation due to β cell mass loss. Other abnormalities like α cell insulin resistance, sensor machinery dysfunction, or paradoxical ATP-sensitive potassium channels (K Topics: Animals; Autocrine Communication; Diabetes Mellitus, Type 1; Diabetes Mellitus, Type 2; Dipeptidyl-Peptidase IV Inhibitors; Glucagon; Glucagon-Like Peptide 1; Glucagon-Secreting Cells; Humans; Hypoglycemic Agents; Insulin-Secreting Cells; Paracrine Communication | 2021 |
Semaglutide (Wegovy) for weight loss.
Topics: Clinical Trials as Topic; Diabetes Mellitus, Type 2; Glucagon-Like Peptide 1; Glucagon-Like Peptides; Humans; Injections, Subcutaneous; Nausea; Weight Loss | 2021 |
Amplifying the antidiabetic actions of glucagon-like peptide-1: Potential benefits of new adjunct therapies.
Clinically approved for the treatment of diabetes and obesity, glucagon-like peptide-1 (GLP-1) receptor agonists display prominent glucose- and weight-lowering effects as well as positive cardioprotective and neuroprotective actions. Despite these benefits, bariatric surgery remains superior in producing robust and sustained weight loss alongside improvements in metabolic control with possible diabetes remission. The current review considers the potential for adjunct therapies to augment the therapeutic actions of GLP-1 receptor agonists. In this regard, several gut-derived hormones also, modulated by bariatric surgery, display additive properties when combined with GLP-1 receptor agonists in both preclinical and clinical studies. In addition, glucocorticoids and oestrogen have shown promise in augmenting the biological actions of GLP-1 in animal models. Additionally, GLP-1 efficacy can also be enhanced by use of compounds that prolong GLP-1 receptor coupling to potentiate downstream receptor signalling. Taken together, therapies that activate GLP-1 receptor signalling, in combination with various other cell signalling pathways, show potential for treating type 2 diabetes and obesity with superiority over GLP-1 receptor agonist therapy alone. Topics: Animals; Blood Glucose; Diabetes Mellitus, Type 2; Glucagon-Like Peptide 1; Humans; Hypoglycemic Agents; Insulin-Secreting Cells | 2021 |
Prevention and Treatment of Atrial Fibrillation via Risk Factor Modification.
Atrial fibrillation (AF) is the most common clinically significant arrhythmia, and it increases stroke risk. A preventive approach to AF is needed because virtually all treatments such as cardioversion, antiarrhythmic drugs, ablation, and anticoagulation are associated with high cost and carry significant risk. A systematic review was performed to identify effective lifestyle-based strategies for reducing primary and secondary AF. A PubMed search was performed using articles up to March 1, 2021. Search terms included atrial fibrillation, atrial flutter, exercise, diet, metabolic syndrome, type 2 diabetes mellitus, obesity, hypertension, stress, tobacco smoking, alcohol, Mediterranean diet, sodium, and omega-3 fatty acids. Additional articles were identified from the bibliographies of retrieved articles. The control of hypertension, ideally with a renin-angiotensin-aldosterone system inhibitor, is effective for preventing primary AF and recurrence. Obstructive sleep apnea is a common cause of AF, and treating it effectively reduces AF episodes. Alcohol increases the risk of AF in a dose-dependent manner, and abstinence reduces risk of recurrence. Sedentary behavior and chronic high-intensity endurance exercise are both risk factors for AF; however, moderate physical activity is associated with lower risk of AF. Recently, sodium-glucose cotransporter-2 inhibitors and glucagon-like peptide-1 agonists have been associated with reduced risk of AF. Among overweight/obese patients, weight loss of ≥10% is associated with reduced AF risk. Lifestyle changes and risk factor modification are highly effective for preventing AF. Topics: Alcohol Drinking; Atrial Fibrillation; Bariatric Surgery; Diabetes Mellitus, Type 2; Diet Therapy; Diet, Mediterranean; Dietary Fats, Unsaturated; Endurance Training; Exercise; Fatty Acids, Omega-3; Glucagon-Like Peptide 1; Humans; Metabolic Syndrome; Obesity; Overweight; Risk Reduction Behavior; Sedentary Behavior; Sleep Apnea, Obstructive; Smoking; Smoking Cessation; Sodium-Glucose Transporter 2 Inhibitors; Weight Loss | 2021 |
Potential new therapeutic target for Alzheimer's disease: Glucagon-like peptide-1.
Increasing evidence shows a close relationship between Alzheimer's disease (AD) and type 2 diabetes mellitus (T2DM). Recently, glucagon-like peptide-1 (GLP-1), a gut incretin hormone, has become a well-established treatment for T2DM and is likely to be involved in treating cognitive impairment. In this mini review, the similarities between AD and T2DM are summarised with the main focus on GLP-1-based therapeutics in AD. Topics: Alzheimer Disease; Cognitive Dysfunction; Diabetes Mellitus, Type 2; Glucagon-Like Peptide 1; Humans | 2021 |
The Effects of Almonds on Gut Microbiota, Glycometabolism, and Inflammatory Markers in Patients with Type 2 Diabetes: A Systematic Review and Meta-Analysis of Randomised Controlled Trials.
The use of nutritional interventions for managing diabetes is one of the effective strategies aimed at reducing the global prevalence of the condition, which is on the rise. Almonds are the most consumed tree nut and they are known to be rich sources of protein, monounsaturated fatty acids, essential minerals, and dietary fibre. Therefore, the aim of this review was to evaluate the effects of almonds on gut microbiota, glycometabolism, and inflammatory parameters in patients with type 2 diabetes.. This systematic review and meta-analysis was carried out according to the preferred reporting items for systematic review and meta-analysis (PRISMA). EBSCOhost, which encompasses the Health Sciences Research Databases; Google Scholar; EMBASE; and the reference lists of articles were searched based on population, intervention, control, outcome, and study (PICOS) framework. Searches were carried out from database inception until 1 August 2021 based on medical subject headings (MesH) and synonyms. The meta-analysis was carried out with the Review Manager (RevMan) 5.3 software.. Nine randomised studies were included in the systematic review and eight were used for the meta-analysis. The results would suggest that almond-based diets have significant effects in promoting the growth of short-chain fatty acid (SCFA)-producing gut microbiota. Furthermore, the meta-analysis showed that almond-based diets were effective in significantly lowering (. The findings of this systematic review and meta-analysis have shown that almond-based diets may be effective in promoting short-chain fatty acid-producing bacteria and lowering glycated haemoglobin and body mass index in patients with type 2 diabetes compared with control. However, the effects of almonds were not significant ( Topics: Biomarkers; Blood Glucose; Body Mass Index; C-Reactive Protein; Diabetes Mellitus, Type 2; Gastrointestinal Microbiome; Glucagon-Like Peptide 1; Glycated Hemoglobin; Homeostasis; Humans; Inflammation; Insulin; Insulin Resistance; Prunus dulcis; Publication Bias; Randomized Controlled Trials as Topic; Risk; Tumor Necrosis Factor-alpha | 2021 |
Treatment of Type 2 Diabetes and Obesity on the Basis of the Incretin System: The 2021 Banting Medal for Scientific Achievement Award Lecture.
In my lecture given on the occasion of the 2021 Banting Medal for Scientific Achievement, I briefly described the history of the incretin effect and summarized some of the developments leading to current therapies of obesity and diabetes based on the incretin hormones, glucagon-like peptide 1 (GLP-1) and glucose-dependent insulinotropic polypeptide (GIP). In the text below, I discuss in further detail the role of these two hormones for postprandial insulin secretion in humans on the basis of recent studies with antagonists. Their direct and indirect actions on the β-cells are discussed next as well as their contrasting actions on glucagon secretion. After a brief discussion of their effect on insulin sensitivity, I describe their immediate actions in patients with type 2 diabetes and emphasize the actions of GLP-1 on β-cell glucose sensitivity, followed by a discussion of their extrapancreatic actions, including effects on appetite and food intake in humans. Finally, possible mechanisms of action of GIP-GLP-1 coagonists are discussed, and it is concluded that therapies based on incretin actions are likely to change the current hesitant therapy of both obesity and diabetes. Topics: Awards and Prizes; Diabetes Mellitus, Type 2; Gastric Inhibitory Polypeptide; Glucagon-Like Peptide 1; Humans; Incretins; Insulin; Insulin-Secreting Cells; Obesity | 2021 |
Microbial regulation of enteroendocrine cells.
There has been an enormous interest to investigate impact of gut microbiota on host physiology over the past decade. To further understand its role at organismal level, it is important to delineate host-microbiota interaction at tissue and cell level. Diet, antibiotics, disease, or surgery produce shifts in composition of the gut microbiota that further alter levels of microbial-derived metabolites. Enteroendocrine cells (EECs) are specialized hormone-producing cells in the gut epithelium that sense changes in the intestinal milieu through chemosensing G protein-coupled receptors. Accordingly, microbial metabolites interact with the EECs to stimulate or suppress hormone secretion, which act through endocrine and paracrine signaling to regulate local intestinal and diverse physiological functions and impact overall host metabolism. The remarkable success of glucagon-like peptide-1-based drugs for treatment of type 2 diabetes and obesity highlights the relevance to investigate microbial regulation of EECs to tackle metabolic diseases through novel microbiota-based therapies. Topics: Diabetes Mellitus, Type 2; Enteroendocrine Cells; Gastrointestinal Microbiome; Glucagon-Like Peptide 1; Humans; Receptors, G-Protein-Coupled | 2021 |
Effects of GLP-1 and Its Analogs on Gastric Physiology in Diabetes Mellitus and Obesity.
The processing of proglucagon in intestinal L cells results in the formation of glucagon, GLP-1, and GLP-2. The GLP-1 molecule becomes active through the effect of proconvertase 1, and it is inactivated by dipeptidyl peptidase IV (DPP-IV), so that the half-life of endogenous GLP-1 is 2-3 min. GLP-1 stimulates insulin secretion from β cells in the islets of Langerhans. Human studies show that infusion of GLP-1 results in slowing of gastric emptying and increased fasting and postprandial gastric volumes. Retardation of gastric emptying reduces postprandial glycemia. Exendin-4 is a peptide agonist of the GLP-1 receptor that promotes insulin secretion. Chemical modifications of exendin-4 and GLP-1 molecules have been accomplished to prolong the half-life of GLP-1 agonists or analogs. This chapter reviews the effects of GLP-1-related drugs used in treatment of diabetes or obesity on gastric motor functions, chiefly gastric emptying. The literature shows that diverse methods have been used to measure effects of the GLP-1-related drugs on gastric emptying, with most studies using the acetaminophen absorption test which essentially measures gastric emptying of liquids during the first hour and capacity to absorb the drug over 4-6 h, expressed as AUC. The most valid measurements by scintigraphy (solids or liquids) and acetaminophen absorption at 30 or 60 min show that GLP-1-related drugs used in diabetes or obesity retard gastric emptying, and this is associated with reduced glycemia and variable effects on food intake and appetite. GLP-1 agonists and analogs are integral to the management of patients with type 2 diabetes mellitus and obesity. The effects on gastric emptying are reduced with long-acting preparations or long-term use of short-acting preparations as a result of tachyphylaxis. The dual agonists targeting GLP-1 and another receptor (GIP) do not retard gastric emptying, based on reports to date. In summary, GLP-1 agonists and analogs are integral to the management of patients with type 2 diabetes mellitus and obesity, and their effects are mediated, at least in part, by retardation of gastric emptying. Topics: Blood Glucose; Diabetes Mellitus, Type 2; Gastric Emptying; Glucagon-Like Peptide 1; Glucagon-Like Peptide-1 Receptor; Humans; Hypoglycemic Agents; Obesity | 2021 |
Effects of oral antidiabetic drugs and glucagon-like peptide-1 receptor agonists on left ventricular diastolic function in patients with type 2 diabetes mellitus: a systematic review and network meta-analysis.
The present study aimed to compare the effects of oral antidiabetic drugs (OADs) and glucagon-like peptide-1 receptor agonists (GLP-1RAs) on left ventricular diastolic function in patients with type 2 diabetes mellitus using a network meta-analysis of randomized controlled trials (RCTs). Literature searches were conducted on Medline, the Cochrane Controlled Trials Registry, and ClinicalTrials.gov . RCTs that assessed the effects on left ventricular diastolic function of OADs and GLP-1RAs in patients with type 2 diabetes were included. The outcome was the value (E/e') obtained by dividing peak early diastolic transmitral flow velocity (E) by the mitral annular early diastolic velocity (e'). Standardized mean differences (SMD) and 95% confidence intervals (CIs) were calculated from a random-effects network meta-analysis. Eight RCTs (592 patients) identified in a literature search met the eligibility criteria for this study and were included in the network meta-analysis. Compared with placebo, liraglutide was the only drug that caused a significant improvement in left ventricular diastolic function (SMD, - 0.65; 95% CI, - 1.23 to - 0.08). In addition, when the effects on left ventricular diastolic function were evaluated across drugs, liraglutide alone caused a significant improvement in left ventricular diastolic function compared with OADs (sitagliptin, linagliptin, pioglitazone, rosiglitazone, voglibose, and glimepiride). From the perspective of preventing the onset of heart failure, the administration of liraglutide for type 2 diabetes is promising. Topics: Diabetes Mellitus, Type 2; Glucagon-Like Peptide 1; Glucagon-Like Peptide-1 Receptor; Humans; Hypoglycemic Agents; Network Meta-Analysis; Pharmaceutical Preparations | 2021 |
Comparison of the effects of 10 GLP-1 RA and SGLT2 inhibitor interventions on cardiovascular, mortality, and kidney outcomes in type 2 diabetes: A network meta-analysis of large randomized trials.
The relative efficacy of different sodium glucose cotransporter 2 (SGLT2) inhibitors and glucagon-like peptide 1 receptor agonists (GLP-1 RAs) in reducing cardiorenal events in type 2 diabetic adults is unclear. We searched PubMed and Embase. Three primary endpoints were major adverse cardiovascular events (MACE), hospitalization for heart failure (HHF), and kidney function progression (KFP). Bayesian network meta-analysis was conducted to synthesize hazard ratio (HR) and 95% confidence interval (CI). We calculated surface under the cumulative ranking curve (SUCRA) to rank drug treatments. Subcutaneous semaglutide (HR 0.73, 95% CI 0.55-0.96) and albiglutide (HR 0.76, 95% CI 0.63-0.93) significantly reduced MACE versus lixisenatide. Canagliflozin (HRs: 0.69, 0.68, 0.67 and 0.58) and empagliflozin (HRs: 0.70, 0.69, 0.68 and 0.59) significantly reduced HHF versus dulaglutide, exenatide, lixisenatide and subcutaneous semaglutide. Dapagliflozin (HRs: 0.62, 0.60, 0.68 and 0.63) and empagliflozin (HRs: 0.64, 0.61, 0.69 and 0.64) significantly reduced KFP versus dulaglutide, exenatide, liraglutide and lixisenatide. Different drug treatments had the maximum SUCRA values as for preventing different cardiorenal endpoints. Different GLP-1 RAs and SGLT2 inhibitors have different efficacy in preventing cardiorenal endpoints in type 2 diabetes, and the most efficacious drugs are different as for preventing different cardiorenal endpoints. Topics: Bayes Theorem; Diabetes Mellitus, Type 2; Glucagon-Like Peptide 1; Glucagon-Like Peptide-1 Receptor; Humans; Hypoglycemic Agents; Kidney; Network Meta-Analysis; Pharmaceutical Preparations; Randomized Controlled Trials as Topic; Sodium-Glucose Transporter 2 Inhibitors | 2021 |
GLP-1 receptor agonists in the treatment of type 2 diabetes - state-of-the-art.
GLP-1 receptor agonists (GLP-1 RAs) with exenatide b.i.d. first approved to treat type 2 diabetes in 2005 have been further developed to yield effective compounds/preparations that have overcome the original problem of rapid elimination (short half-life), initially necessitating short intervals between injections (twice daily for exenatide b.i.d.).. To summarize current knowledge about GLP-1 receptor agonist. Topics: Animals; Blood Glucose; Body Weight; Cardiovascular System; Diabetes Mellitus, Type 2; Exenatide; Glucagon-Like Peptide 1; Glucagon-Like Peptide-1 Receptor; Glucagon-Like Peptides; Humans; Hypoglycemia; Immunoglobulin Fc Fragments; Insulin; Liraglutide; Neurodegenerative Diseases; Peptides; Psoriasis; Recombinant Fusion Proteins | 2021 |
Glucose effectiveness: Lessons from studies on insulin-independent glucose clearance in mice.
Besides insulin-mediated transport of glucose into the cells, an important role is also played by the non-insulin-mediated transport. This latter process is called glucose effectiveness (acronym S Topics: Administration, Intravenous; Adult; Aged; Animals; Biological Transport; Diabetes Mellitus, Type 2; Disease Models, Animal; Female; Gastric Inhibitory Polypeptide; Glucagon; Glucagon-Like Peptide 1; Glucose; Homeostasis; Humans; Incretins; Insulin; Insulin Resistance; Insulin Secretion; Male; Mice; Middle Aged | 2021 |
A review of glucagon-like peptide 1 receptor agonist and sodium-glucose cotransporter 2 inhibitor cardiovascular trials: Implications for practice.
Atherosclerotic cardiovascular disease is the leading cause of morbidity and mortality for people with type 2 diabetes mellitus (T2DM). Previous pharmacological management recommendations focused primarily on glucose lowering. However, new data demonstrate that select glucagon-like peptide 1 receptor agonists (GLP1 RA) and sodium-glucose cotransporter 2 inhibitors (SGLT2is) not only provide glucose lowering but also can reduce the risk of cardiovascular (CV) disease.. The purpose of this study was to evaluate the current data regarding CV benefits of GLP1 RA and SGLT2i in select patients with T2DM and the impact on clinical guidelines so that nurse practitioners may optimize pharmacologic management of patients with T2DM.. A literature review was conducted using the PubMed and CINAHL complete databases to identify studies with CV benefits of GLP1 RA and SGLT2i. Pivotal clinical trials were selected for review.. Select GLP1 RA and SGLT2i can reduce the risk of major adverse CV events, death from CV cases, or hospitalization due to heart failure (HF) in patients with a history of, or at high risk for, CV disease.. Based on data from major CV outcomes trials, clinical guidelines recommend GLP1a or SGLT2i in select patients for glucose lowering and CV risk reduction. In addition, even in patients who have achieved glycemic goals, these agents can provide additional benefit by reducing the incidence of major CV adverse events or hospitalization for HF. Understanding the data will help nurse practitioners select the most appropriate agent for a given individual based on comorbidities. Topics: Cardiovascular Diseases; Diabetes Mellitus, Type 2; Glucagon-Like Peptide 1; Glucose; Humans; Hypoglycemic Agents; Sodium; Sodium-Glucose Transporter 2 Inhibitors | 2021 |
Obesity and GLP-1.
Obesity is an important public health issue that has been on the rise over the last decades. It calls for effective prevention and treatment. Bariatric surgery is the most effective medical therapy for weight loss in morbid obesity, but we are in need for less aggressive treatments. Glucagon-like-peptide-1 receptor agonists are a group of incretin-based drugs that have proven to be productive for obesity treatment. Through activation of the GLP-1 receptor they not only have an important role stimulating insulin secretion after meals, but with their extrapancreatic actions, both peripheral and central, they also help reduce body weight by promoting satiety and delaying gastric emptying. Liraglutide in a dose of 3 mg is currently the only drug of this group that is approved by the FDA to treat obesity, with weight losses up to 8.5 kg in relatively short periods of time. Here we review the data so far collected of GLP-1 use for obesity with and without diabetes, including the recent data of oral semaglutide. Topics: Diabetes Mellitus, Type 2; Glucagon-Like Peptide 1; Glucagon-Like Peptide-1 Receptor; Humans; Incretins; Obesity | 2021 |
Incretin drugs in diabetic kidney disease: biological mechanisms and clinical evidence.
As the prevalence of diabetes continues to climb, the number of individuals living with diabetic complications will reach an unprecedented magnitude. The emergence of new glucose-lowering agents - sodium-glucose cotransporter 2 inhibitors and incretin therapies - has markedly changed the treatment landscape of type 2 diabetes mellitus. In addition to effectively lowering glucose, incretin drugs, which include glucagon-like peptide 1 receptor (GLP1R) agonists and dipeptidyl peptidase 4 (DPP4) inhibitors, can also reduce blood pressure, body weight, the risk of developing or worsening chronic kidney disease and/or atherosclerotic cardiovascular events, and the risk of death. Although kidney disease events have thus far been secondary outcomes in clinical trials, an ongoing phase III trial in patients with diabetic kidney disease will test the effect of a GLP1R agonist on a primary kidney disease outcome. Experimental data have identified the modulation of innate immunity and inflammation as plausible biological mechanisms underpinning the kidney-protective effects of incretin-based agents. These drugs block the mechanisms involved in the pathogenesis of kidney damage, including the activation of resident mononuclear phagocytes, tissue infiltration by non-resident inflammatory cells, and the production of pro-inflammatory cytokines and adhesion molecules. GLP1R agonists and DPP4 inhibitors might also attenuate oxidative stress, fibrosis and cellular apoptosis in the kidney. Topics: Biomarkers; Diabetes Mellitus, Type 2; Diabetic Nephropathies; Dipeptidyl Peptidase 4; Glucagon-Like Peptide 1; Humans; Hypoglycemic Agents; Incretins; Kidney | 2021 |
The Effects of Glucagon-Like Peptide Type 1 (GLP-1) and its Analogues in Adipose Tissue: Is there a way to Thermogenesis?
Obesity is a global problem and the most common metabolic disorder leading to many associated diseases, such as arterial hypertension, ischemic heart disease, type 2 diabetes, certain types of cancer, impaired lipid and uric acid metabolism. The prevalence of obesity has risen globally in the past four decades in both children and adults, and it accounts for the rapid increase in the prevalence of diabetes. Currently, the study of thermogenic tissues, brown and beige adipose tissues, is of extreme value from the point of view of therapeutic potential for obesity and its associated diseases. An analogue of the glucagon-like peptide-1 (GLP-1) liraglutide, used in the treatment of type 2 diabetes, has been proven to have a positive effect on weight loss through appetite suppression. However, this mechanism of weight loss is not the only one involved. This article discusses the main molecular and cellular mechanisms of adipogenesis, as well as the effect of GLP-1 and its analogues, in particular liraglutide on this process through various transcription factors, signaling pathways, and hormones, including brown and beige adipose tissue. Also, the twincretins have had a positive effect on insulin resistance and fat beiging activation. The results of numerous studies have helped us to better understand the peripheral mechanisms of lipid metabolism regulation, and have demonstrated the effectiveness of GLP-1 analogues for the treatment of diabetes and obesity. Topics: Adipose Tissue; Animals; Diabetes Mellitus, Type 2; Glucagon-Like Peptide 1; Humans; Liraglutide; Obesity; Thermogenesis | 2021 |
Characterizing Effects of Antidiabetic Drugs on Heart Rate, Systolic and Diastolic Blood Pressure.
A model-based meta-analysis was performed with reported data from obese subjects and patients with type 2 diabetes (T2DM) to characterize the effects of dipeptidyl peptidase 4 (DPP4) inhibitors, gastric inhibitory polypeptides (GIPs), glucagon-like peptide-1 (GLP1), and dual GIP/GLP1 agonists, or a combination of these antidiabetic drugs (ADs) on heart rate (HR), diastolic blood pressure (DBP), and systolic blood pressure (SBP). A systematic literature search and review after the Cochrane method identified sources for investigational and approved ADs resulted in a comprehensive database with data from 178 clinical studies in obese subjects and patients with T2DM. Results indicated that there were AD class-dependent effects on HR and SBP, whereas no clear AD-related effects on DBP were found. All AD classes, except for DPP4 inhibitors, increased HR. The largest increase of 12 bpm was seen with GLP1 receptor agonists. All AD classes appeared to decrease SBP. DPP4 inhibitors were associated with a marginal decrease of ~ 1 mmHg, whereas GLP1 and GIP/GLP1 dual agonists exhibited the largest decrease of ~ 3 mmHg in SBP. AD-related effects were similar in obese subjects and patients with T2DM. In conclusion, there are clinically relevant AD-related effects on both HR and SBP, but not on DBP. DPP4 inhibitors are associated with the smallest (if at all) effects on HR and SBP, whereas GLP1 inhibitors exhibited the largest effects on these two cardiovascular end points. Additional studies are warranted to further investigate how AD-related SBP decreases combined with HR increases affect long-term cardiovascular mortality. Topics: Animals; Blood Pressure; Diabetes Mellitus, Type 2; Dipeptidyl-Peptidase IV Inhibitors; Gastric Inhibitory Polypeptide; Glucagon-Like Peptide 1; Heart Rate; Humans; Hypoglycemic Agents | 2021 |
Targeting the GIPR for obesity: To agonize or antagonize? Potential mechanisms.
Glucose-dependent insulinotropic peptide (GIP) is one of two incretin hormones that communicate nutrient intake with systemic metabolism. Although GIP was the first incretin hormone to be discovered, the understanding of GIP's biology was quickly outpaced by research focusing on the other incretin hormone, glucagon-like peptide 1 (GLP-1). Early work on GIP produced the theory that GIP is obesogenic, limiting interest in developing GIPR agonists to treat type 2 diabetes. A resurgence of GIP research has occurred in the last five years, reinvigorating interest in this peptide. Two independent approaches have emerged for treating obesity, one promoting GIPR agonism and the other antagonism. In this report, evidence supporting both cases is discussed and hypotheses are presented to reconcile this apparent paradox.. This review presents evidence to support targeting GIPR to reduce obesity. Most of the focus is on the effect of singly targeting the GIPR using both a gain- and loss-of-function approach, with additional sections that discuss co-targeting of the GIPR and GLP-1R.. There is substantial evidence to support that GIPR agonism and antagonism can positively impact body weight. The long-standing theory that GIP drives weight gain is exclusively derived from loss-of-function studies, with no evidence to support that GIPR agonisms increases adiposity or body weight. There is insufficient evidence to reconcile the paradoxical observations that both GIPR agonism and antagonism can reduce body weight; however, two independent hypotheses centered on GIPR antagonism are presented based on new data in an effort to address this question. The first discusses the compensatory relationship between incretin receptors and how antagonism of the GIPR may enhance GLP-1R activity. The second discusses how chronic GIPR agonism may produce desensitization and ultimately loss of GIPR activity that mimics antagonism. Overall, it is clear that a deeper understanding of GIP biology is required to understand how modulating this system impacts metabolic homeostasis. Topics: Adipose Tissue; Animals; Body Weight; Diabetes Mellitus, Type 2; Gastric Inhibitory Polypeptide; Glucagon-Like Peptide 1; Glucagon-Like Peptide-1 Receptor; Humans; Incretins; Mice; Mice, Knockout; Obesity; Weight Gain | 2021 |
Efficacy and Cardiovascular Safety of GLP-1 Receptor Analogues.
Glucagon-like peptide- 1 receptor analogs (GLP-1RAs) are incretin mimetics with potent glucose-dependent insulinotropic action that translates to glycemic control in people with type- -2 diabetes mellitus (T2DM). These agents potentially have the ability to stimulate proliferation or prevent apoptosis of pancreatic β-cells, induce weight-loss and provide vascular benefits in patients with T2DM. Newer GLP-1RA, semaglutide has shown a robust reduction in HbA1c up to 1.5 - 1.8%. However, individual differences exist between the different GLP-1RAs, in terms of efficacy, pharmacokinetics, tolerability, and vascular protection. The potential of vascular protection offered by newer anti-diabetic agents has generated a lot of excitement in the field of diabetes, and to a large extent, is now driving treatment decisions. So far, six cardiovascular outcome trials of GLP-1 RAs have been published, analyzing lixisenatide (ELIXA), liraglutide (LEADER), semaglutide (SUSTAIN-6), long-acting exenatide (EXSCEL), dulaglutide (REWIND), and oral semaglutide (PIONEER 6) with a follow-up duration of 2-4 years. LEADER, REWIND and SUSTAIN-6 trials have demonstrated a reduction in rates of major adverse cardiovascular events with active GLP-1 RA treatment, but ELIXA, PIONEER 6 and EXSCEL, have been neutral. In this review, we discuss the available evidence from randomized controlled trials (RCTs) analyzing the cardiovascular effects of various GLP-1 RAs with the aim of comparing individual drugs. We have also summarized the general aspects of GLP-1RAs that can be applied in clinical practice. Topics: Diabetes Mellitus, Type 2; Exenatide; Glucagon-Like Peptide 1; Glucagon-Like Peptide-1 Receptor; Humans; Hypoglycemic Agents; Liraglutide | 2021 |
GLP-1 agonists for obesity and type 2 diabetes in children: Systematic review and meta-analysis.
Pharmacological options for management of obesity and type 2 diabetes mellitus (T2DM) in children are limited. We aimed to synthesize published randomized controlled trial (RCT) evidence on the efficacy of glucagon-like peptide-1 (GLP-1) agonists in T2DM, pre-diabetes, and obesity in children aged <18 years. Inclusion criteria were RCTs of any GLP-1 agonist, solely or in conjunction with other drugs, for the treatment of obesity, pre-diabetes, and/or T2DM in children aged <18 years old. Nine studies met the inclusion criteria (two for T2DM, one for pre-diabetes, and six for obesity without diabetes). In total, 286 children were allocated to GLP-1 agonist therapy. Compared with controls, GLP-1 agonist therapy reduced HbA1c by -0.30% (95% confidence interval [CI] -0.57, -0.04) with a larger effect in children with (pre-)diabetes (-0.72%; 95% CI -1.17, -0.28; three studies) than in children with obesity (-0.08%; 95% CI -0.13, -0.02; four studies). Conversely, GLP-1 agonist therapy reduced body weight more in children with obesity (-2.74 kg; 95% CI -3.77, -1.70; six studies) than in children with T2DM (-0.97 kg; 95% CI -2.01, 0.08; two studies). Adverse effects included gastrointestinal symptoms and minor hypoglycemic episodes, but not severe hypoglycemia. GLP-1 agonists are efficacious in treating children with obesity and/or T2DM. Effect sizes are comparable with those reported in adults. Topics: Adolescent; Child; Diabetes Mellitus, Type 2; Glucagon-Like Peptide 1; Glucagon-Like Peptide-1 Receptor; Humans; Hypoglycemic Agents; Pediatric Obesity; Randomized Controlled Trials as Topic | 2021 |
[An orally administered glucagon-like peptide 1 (GLP1) analogue: A landmark in the treatment of type 2 diabetes].
Semaglutide is the first peptide to receive European marketing authorization for oral administration in the treatment of type 2 diabetes. The active molecule is the same as the one marketed for weekly subcutaneous administration. It is associated with a new excipient, which protects it from degradation by gastric pepsin and allows its absorption in the stomach. This article presents the pharmacological characteristics of this drug, as well as a critical analysis of the results of the main phase III clinical trials.. Un analogue du glucagon-like peptide 1 (GLP1) administré par voie orale - Une nouveauté dans le traitement du diabète de type 2.. Le sémaglutide est le premier peptide à avoir reçu une autorisation européenne de mise sur le marché, pour une administration quotidienne par voie orale dans le traitement du diabète de type 2. La molécule active est identique à celle qui est déjà commercialisée pour une administration hebdomadaire par voie sous-cutanée. Elle est associée à un nouvel excipent, qui la protège de la dégradation par la pepsine gastrique et permet son absorption dans l’estomac. Cet article présente les caractéristiques pharmacologiques du médicament dans sa nouvelle formulation, ainsi qu’une analyse critique des résultats des principaux essais cliniques de phase III dans lesquels elle a été testée. Topics: Administration, Oral; Clinical Trials, Phase III as Topic; Diabetes Mellitus, Type 2; Drug Therapy, Combination; Glucagon-Like Peptide 1; Glucagon-Like Peptides; Glycated Hemoglobin; Humans; Hypoglycemic Agents | 2021 |
Medication adherence to injectable glucagon-like peptide-1 (GLP-1) receptor agonists dosed once weekly vs once daily in patients with type 2 diabetes: A meta-analysis.
Suboptimal medication adherence has been associated with increased resource utilisation and mortality among patients with type 2 diabetes (T2D). Glucagon-like peptide-1 receptor agonists (GLP-1RAs) are becoming increasingly important in the treatment of T2D. However, medications in this class differ considerably in their dosing frequency, which may impact adherence. We sought to perform a meta-analysis to compare adherence to injectable GLP-1RAs dosed once weekly vs once daily in patients with T2D.. Medline and Scopus were searched from 1/2005 to 7/2020 using keywords and MeSH terms pertaining to adherence and GLP-1RAs. Studies of adults with T2D were included if they compared adherence (as measured by proportion of days covered [PDC]) to injectable GLP-1RAs dosed once weekly vs once daily. A meta-analysis of non-overlapping studies was performed to evaluate the primary outcome of non-adherence, defined as the proportion of patients with a PDC < 80.. Once weekly dosing of injectable GLP-1RAs was associated with better adherence vs once daily dosing among patients with T2D. These findings coupled with the known detrimental consequences of non-adherence suggest that dosing frequency is an important factor to consider when selecting a GLP-1RA. Topics: Adult; Diabetes Mellitus, Type 2; Drug Administration Schedule; Glucagon-Like Peptide 1; Glucagon-Like Peptide-1 Receptor; Glucagon-Like Peptides; Humans; Hypoglycemic Agents; Liraglutide; Medication Adherence; Peptides; Venoms | 2021 |
Engineering of smart nanoconstructs for delivery of glucagon-like peptide-1 analogs.
Glucagon-like peptide-1 (GLP-1) receptor agonists are being increasingly exploited in clinical practice for management of type 2 diabetes mellitus due to their ability to lower blood glucose levels and reduce off-target effects of current therapeutics. Nanomaterials had viewed myriad breakthroughs in protecting peptides against degradation and carrying therapeutics to targeted sites for maximizing their pharmacological activity and overcoming limitations associated with their application. This review highlights the latest advances in designing smart multifunctional nanoconstructs and engineering targeted and stimuli-responsive nanoassemblies for delivery of GLP-1 receptor agonists. Furthermore, advanced nanoconstructs of sophisticated supramolecular assembly yet efficient delivery of GLP-1/GLP-1 analogs, nanodevices that mediate intrinsic GLP-1 secretion per se, and nanomaterials with capabilities to load additional moieties for synergistic antidiabetic effects, are demonstrated. Topics: Diabetes Mellitus, Type 2; Glucagon-Like Peptide 1; Glucagon-Like Peptide-1 Receptor; Humans; Hypoglycemic Agents; Peptides | 2021 |
The gut-brain axis: Identifying new therapeutic approaches for type 2 diabetes, obesity, and related disorders.
The gut-brain axis, which mediates bidirectional communication between the gastrointestinal system and central nervous system (CNS), plays a fundamental role in multiple areas of physiology including regulating appetite, metabolism, and gastrointestinal function. The biology of the gut-brain axis is central to the efficacy of glucagon-like peptide-1 (GLP-1)-based therapies, which are now leading treatments for type 2 diabetes (T2DM) and obesity. This success and research to suggest a much broader role of gut-brain circuits in physiology and disease has led to increasing interest in targeting such circuits to discover new therapeutics. However, our current knowledge of this biology is limited, largely because the scientific tools have not been available to enable a detailed mechanistic understanding of gut-brain communication.. In this review, we provide an overview of the current understanding of how sensory information from the gastrointestinal system is communicated to the central nervous system, with an emphasis on circuits involved in regulating feeding and metabolism. We then describe how recent technologies are enabling a better understanding of this system at a molecular level and how this information is leading to novel insights into gut-brain communication. We also discuss current therapeutic approaches that leverage the gut-brain axis to treat diabetes, obesity, and related disorders and describe potential novel approaches that have been enabled by recent advances in the field.. The gut-brain axis is intimately involved in regulating glucose homeostasis and appetite, and this system plays a key role in mediating the efficacy of therapeutics that have had a major impact on treating T2DM and obesity. Research into the gut-brain axis has historically largely focused on studying individual components in this system, but new technologies are now enabling a better understanding of how signals from these components are orchestrated to regulate metabolism. While this work reveals a complexity of signaling even greater than previously appreciated, new insights are already being leveraged to explore fundamentally new approaches to treating metabolic diseases. Topics: Animals; Appetite; Brain; Central Nervous System; Diabetes Mellitus, Type 2; Enteric Nervous System; Gastrointestinal Microbiome; Gastrointestinal Tract; Glucagon-Like Peptide 1; Homeostasis; Humans; Metabolic Diseases; Obesity; Vagus Nerve | 2021 |
The Emerging Role of Polyphenols in the Management of Type 2 Diabetes.
Type 2 diabetes (T2D) is a fast-increasing health problem globally, and it results from insulin resistance and pancreatic β-cell dysfunction. The gastrointestinal (GI) tract is recognized as one of the major regulatory organs of glucose homeostasis that involves multiple gut hormones and microbiota. Notably, the incretin hormone glucagon-like peptide-1 (GLP-1) secreted from enteroendocrine L-cells plays a pivotal role in maintaining glucose homeostasis via eliciting pleiotropic effects, which are largely mediated via its receptor. Thus, targeting the GLP-1 signaling system is a highly attractive therapeutic strategy to treatment T2D. Polyphenols, the secondary metabolites from plants, have drawn considerable attention because of their numerous health benefits, including potential anti-diabetic effects. Although the major targets and locations for the polyphenolic compounds to exert the anti-diabetic action are still unclear, the first organ that is exposed to these compounds is the GI tract in which polyphenols could modulate enzymes and hormones. Indeed, emerging evidence has shown that polyphenols can stimulate GLP-1 secretion, indicating that these natural compounds might exert metabolic action at least partially mediated by GLP-1. This review provides an overview of nutritional regulation of GLP-1 secretion and summarizes recent studies on the roles of polyphenols in GLP-1 secretion and degradation as it relates to metabolic homeostasis. In addition, the effects of polyphenols on microbiota and microbial metabolites that could indirectly modulate GLP-1 secretion are also discussed. Topics: Diabetes Mellitus, Type 2; Gastrointestinal Hormones; Glucagon-Like Peptide 1; Humans; Insulin; Insulin Secretion; Insulin-Secreting Cells; Polyphenols | 2021 |
Polymeric microparticle systems for modified release of glucagon-like-peptide-1 receptor agonists.
Type 2 diabetes is a fast-growing worldwide epidemic. Despite the multiple therapies available to treat type 2 diabetes, the disease is not correctly managed in over half of patients, mainly due to non-compliance with prescribed treatment regimes. The development of analogues to the glucagon-like peptide 1 (GLP-1) has resulted in the extension of its half-life and associated benefits. Further benefits in the use of peptide-based GLP-1 receptor agonists have been achieved by the use of controlled-release systems based on polymeric microparticles. In this review, we focus on commercially available formulations and others that remain in development, discussing the preparation methods and the relationship between Topics: Diabetes Mellitus, Type 2; Drug Compounding; Glucagon-Like Peptide 1; Glucagon-Like Peptide-1 Receptor; Humans; Hypoglycemic Agents; Particle Size; Polymers | 2021 |
Obstetrician-Gynecologists' Strategies for Patient Initiation and Maintenance of Antiobesity Treatment with Glucagon-Like Peptide-1 Receptor Agonists.
Obesity is a chronic disease affecting women at higher rates than men. In an obstetrics and gynecology setting, frequently encountered obesity-related complications are polycystic ovary syndrome, fertility and pregnancy complications, and increased risk of breast and gynecological cancers. Obstetrician-gynecologists (OBGYNs) are uniquely positioned to diagnose and treat obesity, given their role in women's primary health care and the increasing prevalence of obesity-related fertility and pregnancy complications. The metabolic processes of bodyweight regulation are complex, which makes weight-loss maintenance challenging, despite dietary modifications and exercise. Antiobesity medications (AOMs) can facilitate weight loss by targeting appetite regulation. There are four AOMs currently approved for long-term use in the United States, of which liraglutide 3.0 mg is among the most efficacious. Liraglutide 3.0 mg, a glucagon-like peptide-1 receptor agonist (GLP-1 RA), is superior to placebo in achieving weight loss and improving cardiometabolic profile, in both clinical trial and real-world settings. In addition, women with fertility complications receiving liraglutide 1.8-3.0 mg can benefit from improved ovarian function and fertility. Liraglutide 3.0 mg is generally well tolerated, but associated with transient gastrointestinal side effects, which can be mitigated. In this review, we present the risks of obesity and benefits of weight loss for women, and summarize clinical development of GLP-1 RAs for weight management. Finally, we provide practical advice and recommendations for OBGYNs to open the discussion about bodyweight with their patients, initiate lifestyle modification and GLP-1 RA treatment, and help them persist with these interventions to achieve optimal weight loss with associated health benefits. Topics: Anti-Obesity Agents; Diabetes Mellitus, Type 2; Female; Glucagon-Like Peptide 1; Glucagon-Like Peptide-1 Receptor; Humans; Hypoglycemic Agents; Liraglutide; Male; Weight Loss | 2021 |
Irisin and Incretin Hormones: Similarities, Differences, and Implications in Type 2 Diabetes and Obesity.
Incretins are gut hormones that potentiate glucose-stimulated insulin secretion (GSIS) after meals. Glucagon-like peptide-1 (GLP-1) is the most investigated incretin hormone, synthesized mainly by L cells in the lower gut tract. GLP-1 promotes β-cell function and survival and exerts beneficial effects in different organs and tissues. Irisin, a myokine released in response to a high-fat diet and exercise, enhances GSIS. Similar to GLP-1, irisin augments insulin biosynthesis and promotes accrual of β-cell functional mass. In addition, irisin and GLP-1 share comparable pleiotropic effects and activate similar intracellular pathways. The insulinotropic and extra-pancreatic effects of GLP-1 are reduced in type 2 diabetes (T2D) patients but preserved at pharmacological doses. GLP-1 receptor agonists (GLP-1RAs) are therefore among the most widely used antidiabetes drugs, also considered for their cardiovascular benefits and ability to promote weight loss. Irisin levels are lower in T2D patients, and in diabetic and/or obese animal models irisin administration improves glycemic control and promotes weight loss. Interestingly, recent evidence suggests that both GLP-1 and irisin are also synthesized within the pancreatic islets, in α- and β-cells, respectively. This review aims to describe the similarities between GLP-1 and irisin and to propose a new potential axis-involving the gut, muscle, and endocrine pancreas that controls energy homeostasis. Topics: Diabetes Mellitus, Type 2; Fibronectins; Glucagon-Like Peptide 1; Humans; Hypoglycemic Agents; Incretins; Insulin-Secreting Cells; Obesity | 2021 |
The role of GLP-1 in postprandial glucose metabolism after bariatric surgery: a narrative review of human GLP-1 receptor antagonist studies.
The Roux-en-Y gastric bypass (RYGB) and sleeve gastrectomy (SG) bariatric procedures lead to remission or improvement of type 2 diabetes. A weight loss-independent augmentation of postprandial insulin secretion contributes to the improvement in glycemic control after RYGB and is associated with a ∼10-fold increase in plasma concentrations of the incretin hormone glucagon-like peptide-1 (GLP-1). However, the physiologic importance of the markedly increased postprandial GLP-1 secretion after RYGB has been much debated. The effect of GLP-1 receptor blockade after RYGB has been investigated in 12 studies. The studies indicate a shift toward a more prominent role for GLP-1 in postprandial β-cell function after RYGB. The effect of GLP-1 receptor antagonism on glucose tolerance after RYGB is more complex and is associated with important methodological challenges. The postprandial GLP-1 response is less enhanced after SG compared with RYGB. However, the effect of GLP-1 receptor blockade after SG has been examined in 1 study only and needs further investigation. Topics: Bariatric Surgery; Blood Glucose; Diabetes Mellitus, Type 2; Gastrectomy; Gastric Bypass; Glucagon-Like Peptide 1; Glucagon-Like Peptide-1 Receptor; Humans; Insulin | 2021 |
The Role of Incretins on Insulin Function and Glucose Homeostasis.
The incretin effect-the amplification of insulin secretion after oral vs intravenous administration of glucose as a mean to improve glucose tolerance-was suspected even before insulin was discovered, and today we know that the effect is due to the secretion of 2 insulinotropic peptides, glucose-dependent insulinotropic polypeptide (GIP) and glucagon-like peptide-1 (GLP-1). But how important is it? Physiological experiments have shown that, because of the incretin effect, we can ingest increasing amounts of amounts of glucose (carbohydrates) without increasing postprandial glucose excursions, which otherwise might have severe consequences. The mechanism behind this is incretin-stimulated insulin secretion. The availability of antagonists for GLP-1 and most recently also for GIP has made it possible to directly estimate the individual contributions to postprandial insulin secretion of a) glucose itself: 26%; b) GIP: 45%; and c) GLP-1: 29%. Thus, in healthy individuals, GIP is the champion. When the action of both incretins is prevented, glucose tolerance is pathologically impaired. Thus, after 100 years of research, we now know that insulinotropic hormones from the gut are indispensable for normal glucose tolerance. The loss of the incretin effect in type 2 diabetes, therefore, contributes greatly to the impaired postprandial glucose control. Topics: Blood Glucose; Diabetes Mellitus, Type 2; Gastric Inhibitory Polypeptide; Glucagon-Like Peptide 1; Homeostasis; Humans; Incretins; Insulin; Insulin Secretion; Postprandial Period; Receptors, Gastrointestinal Hormone | 2021 |
Role of GLP-1 Analogs in the Management of Diabetes and its Secondary Complication.
The cardiovascular complications of Type 2 Diabetes Mellitus (T2DM) including myocardial infarction, heart failure, peripheral vascular disease and, stroke and retinopathy, nephropathy and neuropathy are microvascular complications. While the newer therapies like glitazones or even Dipeptidyl- peptidase-IV (DPP-IV) inhibitors increase the risk of therapy, the Glucagon Like Peptide-1 Receptor Agonists (GLP-1RAs), were reported as suitable alternates. The GLP-1RAs reduce Major Adverse Cardiovascular Events (MACE), have anti-atherogenic potential, and possess pleiotropic activity. The GLP-1RAs were found to improve neuroprotection, enhance neuronal growth, reduce the incidence of stroke, and improve central insulin resistance. The GLP-1RAs are beneficial in improving the glycemic profile, preventing macroalbuminuria and reducing the decline in eGFR and enhancing renal protection. The renal benefits of add-on therapy of GLP-1RAs with SGLT-2 inhibitors have composite renal outcomes such as suppression of inflammatory pathways, improvement in natriuresis, diuresis, found to be nephroprotective. Improvement in glycemic control with a reduction in body weight and intraglomerular pressure and prevention of tubular injury makes the GLP-1RAs as suitable add-on therapies in improving cardiorenal outcomes. Obesity, an important contributor to insulin resistance and a reduction in weight, is an essential therapeutic option in addressing diabetic-obesity. It also reduces the damage to blood-retinal-barrier, thus beneficial in halting the development of diabetic retinopathy. In diabetic complications, glycemic control, addressing insulin resistance through weight loss, controlling atherosclerosis through anti-inflammatory effects and cardio-renal-neuro protection, makes GLP-1RAs a suitable therapeutic strategy on long-term treatment of T2DM. This review discusses the role of GLP-1RAs in diabetes, the dosage, mono or combination therapy with other antidiabetics in long-term treatment and its effect in uncontrolled diabetes. Topics: Diabetes Mellitus, Type 2; Dipeptidyl-Peptidase IV Inhibitors; Glucagon-Like Peptide 1; Glucagon-Like Peptide-1 Receptor; Humans; Hypoglycemic Agents | 2021 |
Gut-Based Strategies to Reduce Postprandial Glycaemia in Type 2 Diabetes.
Postprandial glycemic control is an important target for optimal type 2 diabetes management, but is often difficult to achieve. The gastrointestinal tract plays a major role in modulating postprandial glycaemia in both health and diabetes. The various strategies that have been proposed to modulate gastrointestinal function, particularly by slowing gastric emptying and/or stimulating incretin hormone GLP-1, are summarized in this review. Topics: Blood Glucose; Diabetes Mellitus, Type 2; Gastric Emptying; Glucagon-Like Peptide 1; Humans; Incretins; Postprandial Period | 2021 |
Lipid effects of glucagon-like peptide 1 receptor analogs.
Glucagon-like peptide-1 receptor agonists (GLP-1RAs) are becoming more prominent as a therapeutic choice in diabetes management and their use is being expanded to other indications, such as obesity. Dyslipidemia and cardiovascular disease are common co-morbidities in these populations and understanding the impact of this class of medications on the lipid profile may be an important consideration.. Several GLP-1RAs trials demonstrate them to be safe and potentially beneficial for cardiovascular outcomes; improvements in surrogate markers of atherosclerosis have also been observed. Lipid data collected as secondary outcomes from large clinical trials as well as some smaller dedicated trials show that GLP-1RAs can modestly lower low-density lipoprotein (LDL) and total cholesterol (C), and most show modest fasting triglyceride (TG) lowering. Effects on high-density lipoprotein-C have been less consistent. Some have also demonstrated substantial blunting of the postprandial rise in serum TGs. Favorable effects on lipoprotein metabolism, with reduced levels of small dense LDL particles and decreased atherogenic potential of oxidized LDL, have also been seen. Mechanisms underlying these observations have been investigated.. This review summarizes the data available on the lipid effects of GLP-1RAs, and explores the current understanding of the mechanisms underlying these observed effects. Topics: Diabetes Mellitus, Type 2; Glucagon-Like Peptide 1; Glucagon-Like Peptide-1 Receptor; Humans; Lipid Metabolism; Randomized Controlled Trials as Topic | 2021 |
Emerging Role of Caveolin-1 in GLP-1 Action.
Glucagon-like peptide-1 (GLP-1) is a gut hormone mainly produced in the intestinal epithelial endocrine L cells, involved in maintaining glucose homeostasis. The use of GLP-1 analogous and dipeptidyl peptidase-IV (DPP-IV) inhibitors is well-established in Type 2 Diabetes. The efficacy of these therapies is related to the activation of GLP-1 receptor (GLP-1R), which is widely expressed in several tissues. Therefore, GLP-1 is of great clinical interest not only for its actions at the level of the beta cells, but also for the extra-pancreatic effects. Activation of GLP-1R results in intracellular signaling that is regulated by availability of downstream molecules and receptor internalization. It has been shown that GLP-1R co-localizes with caveolin-1, the main component of caveolae, small invagination of the plasma membrane, which are involved in controlling receptor activity by assembling signaling complexes and regulating receptor trafficking. The aim of this review is to outline the important role of caveolin-1 in mediating biological effects of GLP-1 and its analogous. Topics: Animals; Caveolin 1; Diabetes Mellitus, Type 2; Dipeptidyl-Peptidase IV Inhibitors; Glucagon-Like Peptide 1; Glucagon-Like Peptide-1 Receptor; Homeostasis; Humans; Hypoglycemic Agents | 2021 |
Mechanisms of Beta-Cell Apoptosis in Type 2 Diabetes-Prone Situations and Potential Protection by GLP-1-Based Therapies.
Type 2 diabetes (T2D) is characterized by chronic hyperglycemia secondary to the decline of functional beta-cells and is usually accompanied by a reduced sensitivity to insulin. Whereas altered beta-cell function plays a key role in T2D onset, a decreased beta-cell mass was also reported to contribute to the pathophysiology of this metabolic disease. The decreased beta-cell mass in T2D is, at least in part, attributed to beta-cell apoptosis that is triggered by diabetogenic situations such as amyloid deposits, lipotoxicity and glucotoxicity. In this review, we discussed the molecular mechanisms involved in pancreatic beta-cell apoptosis under such diabetes-prone situations. Finally, we considered the molecular signaling pathways recruited by glucagon-like peptide-1-based therapies to potentially protect beta-cells from death under diabetogenic situations. Topics: Animals; Apoptosis; Cells, Cultured; Diabetes Mellitus, Type 2; Disease Models, Animal; Glucagon-Like Peptide 1; Glucose; Humans; Hyperglycemia; Insulin; Insulin Resistance; Insulin-Secreting Cells; Islets of Langerhans; Signal Transduction | 2021 |
Proglucagon-Derived Peptides as Therapeutics.
Topics: Diabetes Mellitus, Type 2; Glucagon; Glucagon-Like Peptide 1; Glucagon-Like Peptide 2; Humans; Proglucagon | 2021 |
The Role of GIP in the Regulation of GLP-1 Satiety and Nausea.
Gastric inhibitory peptide (GIP) is best known for its role as an incretin hormone in control of blood glucose concentrations. As a classic satiation signal, however, the literature illustrates a mixed picture of GIP involvement with an at best weak anorectic response profile being reported for GIP receptor (GIPR) signaling. Not surprisingly, the pursuit of exploiting the GIP system as a therapeutic target for diabetes and obesity has fallen behind that of the other gastrointestinal-derived incretin, glucagon-like peptide 1 (GLP-1). However, recent discoveries highlighted here support potential therapeutic advantages of combinatorial therapies targeting GIP and GLP-1 systems together, with perhaps the most surprising finding that GIPR agonism may have antiemetic properties. As nausea and vomiting are the most common side effects of all existing GLP-1 pharmacotherapies, the ability for GIP agonism to reduce GLP-1-induced illness behaviors but retain (if not enhance) weight loss and glycemic control may offer a new era in the treatment of obesity and diabetes. Topics: Animals; Diabetes Mellitus, Type 2; Gastric Inhibitory Polypeptide; Glucagon-Like Peptide 1; Humans; Nausea; Obesity; Satiation | 2021 |
Protein- and Calcium-Mediated GLP-1 Secretion: A Narrative Review.
Glucagon-like peptide 1 (GLP-1) is an incretin hormone produced in the intestine that is secreted in response to nutrient exposure. GLP-1 potentiates glucose-dependent insulin secretion from the pancreatic β cells and promotes satiety. These important actions on glucose metabolism and appetite have led to widespread interest in GLP-1 receptor agonism. Typically, this involves pharmacological GLP-1 mimetics or targeted inhibition of dipeptidyl peptidase-IV, the enzyme responsible for GLP-1 degradation. However, nutritional strategies provide a widely available, cost-effective alternative to pharmacological strategies for enhancing hormone release. Recent advances in nutritional research have implicated the combined ingestion of protein and calcium with enhanced endogenous GLP-1 release, which is likely due to activation of receptors with high affinity and/or sensitivity for amino acids and calcium. Specifically targeting these receptors could enhance gut hormone secretion, thus providing a new therapeutic option. This narrative review provides an overview of the latest research on protein- and calcium-mediated GLP-1 release with an emphasis on human data, and a perspective on potential mechanisms that link potent GLP-1 release to the co-ingestion of protein and calcium. In light of these recent findings, potential future research directions are also presented. Topics: Calcium; Diabetes Mellitus, Type 2; Glucagon-Like Peptide 1; Humans; Insulin Secretion; Insulin-Secreting Cells | 2021 |
A 2021 Update on the Use of Liraglutide in the Modern Treatment of 'Diabesity': A Narrative Review.
Obesity and type 2 diabetes mellitus have become a significant public health problem in the past decades. Their prevalence is increasing worldwide each year, greatly impacting the economic and personal aspects, mainly because they frequently coexist, where the term "diabesity" may be used. The drug class of glucagon-like peptide 1 receptor agonists (GLP-1 RAs) is one of the most modern therapy options in managing these metabolic disorders. This review focuses on the effects of liraglutide, a long-acting GLP-1 RA, in diabesity and non-diabetic excess weight. This drug class improves glycemic control by enhancing insulin secretion from the beta-pancreatic cells and inhibiting glucagon release. Furthermore, other effects include slowing gastric emptying, increasing postprandial satiety, and reducing the appetite and food consumption by influencing the central nervous system, with weight reduction effects. It also reduces cardiovascular events and has positive effects on blood pressure and lipid profile. A lower-dose liraglutide (1.2 or 1.8 mg/day) is used in patients with diabetes, while the higher dose (3.0 mg/day) is approved as an anti-obesity drug. In this review, we have summarized the role of liraglutide in clinical practice, highlighting its safety and efficacy as a glucose-lowering agent and a weight-reduction drug in patients with and without diabetes. Topics: Diabetes Mellitus, Type 2; Glucagon-Like Peptide 1; Glucagon-Like Peptide-1 Receptor; Humans; Hypoglycemic Agents; Liraglutide | 2021 |
Lessons from bariatric surgery: Can increased GLP-1 enhance vascular repair during cardiometabolic-based chronic disease?
Type 2 diabetes (T2D) and obesity represent entangled pandemics that accelerate the development of cardiovascular disease (CVD). Given the immense burden of CVD in society, non-invasive prevention and treatment strategies to promote cardiovascular health are desperately needed. During T2D and obesity, chronic dysglycemia and abnormal adiposity result in systemic oxidative stress and inflammation that deplete the vascular regenerative cell reservoir in the bone marrow that impairs blood vessel repair and exacerbates the penetrance of CVD co-morbidities. This novel translational paradigm, termed 'regenerative cell exhaustion' (RCE), can be detected as the depletion and dysfunction of hematopoietic and endothelial progenitor cell lineages in the peripheral blood of individuals with established T2D and/or obesity. The reversal of vascular RCE has been observed after administration of the sodium-glucose cotransporter-2 inhibitor (SGLT2i), empagliflozin, or after bariatric surgery for severe obesity. In this review, we explore emerging evidence that links improved dysglycemia to a reduction in systemic oxidative stress and recovery of circulating pro-vascular progenitor cell content required for blood vessel repair. Given that bariatric surgery consistently increases systemic glucagon-like-peptide 1 (GLP-1) release, we also focus on evidence that the use of GLP-1 receptor agonists (GLP-1RA) during obesity may act to inhibit the progression of systemic dysglycemia and adiposity, and indirectly reduce inflammation and oxidative stress, thereby limiting the impact of RCE. Therefore, therapeutic intervention with currently-available GLP-1RA may provide a less-invasive modality to reverse RCE, bolster vascular repair mechanisms, and improve cardiometabolic risk in individuals living with T2D and obesity. Topics: Bariatric Surgery; Cardiovascular Diseases; Chronic Disease; Diabetes Mellitus, Type 2; Glucagon-Like Peptide 1; Glucagon-Like Peptide-1 Receptor; Humans; Hypoglycemic Agents; Sodium-Glucose Transporter 2 Inhibitors | 2021 |
Anti-diabetic drugs and weight loss in patients with type 2 diabetes.
Obesity is frequently a comorbidity of type 2 diabetes. Even modest weight loss can significantly improve glucose homeostasis and lessen cardiometabolic risk factors in patients with type 2 diabetes, but lifestyle-based weight loss strategies are not long-term effective. There is an increasing need to consider pharmacological approaches to assist weight loss in the so called diabesity syndrome. Aim of this review is to analyze the weight-loss effect of non-insulin glucose lowering drugs in patients with type 2 diabetes.. A systematic analysis of the literature on the effect of non-insulin glucose lowering drugs on weight loss in patients with type 2 diabetes was performed. For each class of drugs, the following parameters were analyzed: kilograms lost on average, effect on body mass index and body composition.. Our results suggested that anti-diabetic drugs can be stratified into 3 groups based on their efficacy in weight loss: metformin, acarbose, empagliflozin and exenatide resulted in a in a mild weight loss (less than 3.2% of initial weight); canagliflozin, ertugliflozin, dapagliflozin and dulaglutide induces a moderate weight loss (between 3.2% and 5%); liraglutide, semaglutide and tirzepatide resulted in a strong weight loss (greater than 5%).. This study shows that new anti-diabetic drugs, particularly GLP1-RA and Tirzepatide, are the most effective in inducing weight loss in patients with type 2 diabetes. Interestingly, exenatide appears to be the only GLP1-RA that induces a mild weight loss. Topics: Diabetes Mellitus, Type 2; Gastric Inhibitory Polypeptide; Glucagon-Like Peptide 1; Glucagon-Like Peptide-1 Receptor; Humans; Hypoglycemic Agents; Obesity; Weight Loss | 2021 |
The evolving story of incretins (GIP and GLP-1) in metabolic and cardiovascular disease: A pathophysiological update.
The incretin hormones glucose-dependent insulinotropic polypeptide (GIP) and glucagon-like peptide-1 (GLP-1) have their main physiological role in augmenting insulin secretion after their nutrient-induced secretion from the gut. A functioning entero-insular (gut-endocrine pancreas) axis is essential for the maintenance of a normal glucose tolerance. This is exemplified by the incretin effect (greater insulin secretory response to oral as compared to "isoglycaemic" intravenous glucose administration due to the secretion and action of incretin hormones). GIP and GLP-1 have additive effects on insulin secretion. Local production of GIP and/or GLP-1 in islet α-cells (instead of enteroendocrine K and L cells) has been observed, and its significance is still unclear. GLP-1 suppresses, and GIP increases glucagon secretion, both in a glucose-dependent manner. GIP plays a greater physiological role as an incretin. In type 2-diabetic patients, the incretin effect is reduced despite more or less normal secretion of GIP and GLP-1. While insulinotropic effects of GLP-1 are only slightly impaired in type 2 diabetes, GIP has lost much of its acute insulinotropic activity in type 2 diabetes, for largely unknown reasons. Besides their role in glucose homoeostasis, the incretin hormones GIP and GLP-1 have additional biological functions: GLP-1 at pharmacological concentrations reduces appetite, food intake, and-in the long run-body weight, and a similar role is evolving for GIP, at least in animal studies. Human studies, however, do not confirm these findings. GIP, but not GLP-1 increases triglyceride storage in white adipose tissue not only through stimulating insulin secretion, but also by interacting with regional blood vessels and GIP receptors. GIP, and to a lesser degree GLP-1, play a role in bone remodelling. GLP-1, but not GIP slows gastric emptying, which reduces post-meal glycaemic increments. For both GIP and GLP-1, beneficial effects on cardiovascular complications and neurodegenerative central nervous system (CNS) disorders have been observed, pointing to therapeutic potential over and above improving diabetes complications. The recent finding that GIP/GLP-1 receptor co-agonists like tirzepatide have superior efficacy compared to selective GLP-1 receptor agonists with respect to glycaemic control as well as body weight has renewed interest in GIP, which previously was thought to be without any therapeutic potential. One focus of this research is into the long- Topics: Animals; Blood Glucose; Cardiovascular Diseases; Diabetes Mellitus, Type 2; Gastric Inhibitory Polypeptide; Glucagon-Like Peptide 1; Humans; Incretins; Receptors, Gastrointestinal Hormone | 2021 |
Preproglucagon Products and Their Respective Roles Regulating Insulin Secretion.
Historically, intracellular function and metabolic adaptation within the α-cell has been understudied, with most of the attention being placed on the insulin-producing β-cells due to their role in the pathophysiology of type 2 diabetes mellitus. However, there is a growing interest in understanding the function of other endocrine cell types within the islet and their paracrine role in regulating insulin secretion. For example, there is greater appreciation for α-cell products and their contributions to overall glucose homeostasis. Several recent studies have addressed a paracrine role for α-cell-derived glucagon-like peptide-1 (GLP-1) in regulating glucose homeostasis and responses to metabolic stress. Further, other studies have demonstrated the ability of glucagon to impact insulin secretion by acting through the GLP-1 receptor. These studies challenge the central dogma surrounding α-cell biology describing glucagon's primary role in glucose counterregulation to one where glucagon is critical in regulating both hyper- and hypoglycemic responses. Herein, this review will update the current understanding of the role of glucagon and α-cell-derived GLP-1, placing emphasis on their roles in regulating glucose homeostasis, insulin secretion, and β-cell mass. Topics: Animals; Blood Glucose; Diabetes Mellitus, Type 2; Glucagon; Glucagon-Like Peptide 1; Glucagon-Secreting Cells; Glucose; Homeostasis; Humans; Insulin; Insulin Secretion; Insulin-Secreting Cells; Mice; Pancreas; Proglucagon | 2021 |
New progress in drugs treatment of diabetic kidney disease.
Diabetic kidney disease (DKD) is not only one of the main complications of diabetes, but also the leading cause of the end-stage renal disease (ESRD). The occurrence and development of DKD have always been a serious clinical problem that leads to the increase of morbidity and mortality and the severe damage to the quality of life of human beings. Controlling blood glucose, blood pressure, blood lipids, and improving lifestyle can help slow the progress of DKD. In recent years, with the extensive research on the pathological mechanism and molecular mechanism of DKD, there are more and more new drugs based on this, such as new hypoglycemic drugs sodium-glucose cotransporter 2 (SGLT2) inhibitors, glucagon-like peptide-1 (GLP-1) inhibitors, and dipeptidyl peptidase-4 (DPP-4) inhibitors with good efficacy in clinical treatment. Besides, there are some newly developed drugs, including protein kinase C (PKC) inhibitors, advanced glycation end product (AGE) inhibitors, aldosterone receptor inhibitors, endothelin receptor (ETR) inhibitors, transforming growth factor-β (TGF-β) inhibitors, Rho kinase (ROCK) inhibitors and so on, which show positive effects in animal or clinical trials and bring hope for the treatment of DKD. In this review, we sort out the progress in the treatment of DKD in recent years, the research status of some emerging drugs, and the potential drugs for the treatment of DKD in the future, hoping to provide some directions for clinical treatment of DKD. Topics: Animals; Blood Glucose; Diabetes Mellitus, Type 2; Diabetic Nephropathies; Dipeptidyl-Peptidase IV Inhibitors; Glucagon-Like Peptide 1; Humans; Hypoglycemic Agents; Sodium-Glucose Transporter 2 Inhibitors; Treatment Outcome | 2021 |
[Novel indications for GLP-1-analogues and SGLT-2-inhibitors: when should a general practitioner prescribe these agents?]
Topics: Diabetes Mellitus, Type 2; Dipeptidyl-Peptidase IV Inhibitors; General Practitioners; Glucagon-Like Peptide 1; Glucagon-Like Peptide-1 Receptor; Humans; Hypoglycemic Agents; Sodium-Glucose Transporter 2 Inhibitors | 2021 |
Potential for Gut Peptide-Based Therapy in Postprandial Hypotension.
Postprandial hypotension (PPH) is an important and under-recognised disorder resulting from inadequate compensatory cardiovascular responses to meal-induced splanchnic blood pooling. Current approaches to management are suboptimal. Recent studies have established that the cardiovascular response to a meal is modulated profoundly by gastrointestinal factors, including the type and caloric content of ingested meals, rate of gastric emptying, and small intestinal transit and absorption of nutrients. The small intestine represents the major site of nutrient-gut interactions and associated neurohormonal responses, including secretion of glucagon-like peptide-1, glucose-dependent insulinotropic peptide and somatostatin, which exert pleotropic actions relevant to the postprandial haemodynamic profile. This review summarises knowledge relating to the role of these gut peptides in the cardiovascular response to a meal and their potential application to the management of PPH. Topics: Acarbose; Blood Glucose; Blood Pressure; Diabetes Mellitus, Type 2; Gastric Inhibitory Polypeptide; Gastrointestinal Agents; Glucagon; Glucagon-Like Peptide 1; Glucagon-Like Peptide-1 Receptor; Humans; Hypotension; Insulin; Peptides; Postprandial Period; Somatostatin; Splanchnic Circulation | 2021 |
New Insights into Beta-Cell GLP-1 Receptor and cAMP Signaling.
Harnessing the translational potential of the GLP-1/GLP-1R system in pancreatic beta cells has led to the development of established GLP-1R-based therapies for the long-term preservation of beta cell function. In this review, we discuss recent advances in the current research on the GLP-1/GLP-1R system in beta cells, including the regulation of signaling by endocytic trafficking as well as the application of concepts such as signal bias, allosteric modulation, dual agonism, polymorphic receptor variants, spatial compartmentalization of cAMP signaling and new downstream signaling targets involved in the control of beta cell function. Topics: Animals; Cyclic AMP; Diabetes Mellitus, Type 2; Glucagon-Like Peptide 1; Glucagon-Like Peptide-1 Receptor; Humans; Incretins; Insulin; Insulin Secretion; Insulin-Secreting Cells; Polymorphism, Single Nucleotide; Signal Transduction | 2020 |
A Review on the Effects of New Anti-Diabetic Drugs on Platelet Function.
Cardiovascular complications account for the majority of deaths caused by diabetes mellitus. Platelet hyperactivity has been shown to increase the risk of thrombotic events and is a therapeutic target for their prevention in diabetes. Modulation of platelet function by diabetes agents in addition to their hypoglycemic effects would contribute to cardiovascular protection. Newly introduced antidiabetic drugs of sodium-glucose cotransporter 2 inhibitors (SGLT2i), glucagon like peptide-1 receptor agonists (GLP-1RA) and dipeptidyl peptidase-4 inhibitors may have anti-platelet effects, and in the case of SGLT2i and GLP-1RA may contribute to their proven cardiovascular benefit that has been shown clinically.. Here, we reviewed the potential effects of these agents on platelet function in diabetes.. GLP-1RA and DPP-4i drugs have antiplatelet properties beyond their primary hypoglycemic effects. Whilst we have little direct evidence for the antiplatelet effects of SGLT2 inhibitors, some studies have shown that these agents may inhibit platelet aggregation and reduce the risk of thrombotic events in diabetes. Topics: Animals; Blood Platelets; Cardiovascular Diseases; Diabetes Mellitus, Type 2; Dipeptidyl-Peptidase IV Inhibitors; Glucagon-Like Peptide 1; Humans; Hypoglycemic Agents; Platelet Aggregation Inhibitors; Platelet Function Tests; Sodium-Glucose Transporter 2 Inhibitors; Treatment Outcome | 2020 |
An Overview of Prospective Drugs for Type 1 and Type 2 Diabetes.
The aim of this study is to provide an overview of several emerging anti-diabetic molecules.. Diabetes is a complex metabolic disorder involving the dysregulation of glucose homeostasis at various levels. Insulin, which is produced by β-pancreatic cells, is a chief regulator of glucose metabolism, regulating its consumption within cells, which leads to energy generation or storage as glycogen. Abnormally low insulin secretion from β-cells, insulin insensitivity, and insulin tolerance lead to higher plasma glucose levels, resulting in metabolic complications. The last century has witnessed extraordinary efforts by the scientific community to develop anti-diabetic drugs, and these efforts have resulted in the discovery of exogenous insulin and various classes of oral anti-diabetic drugs.. Despite these exhaustive anti-diabetic pharmaceutical and therapeutic efforts, long-term glycemic control, hypoglycemic crisis, safety issues, large-scale economic burden and side effects remain the core problems.. The last decade has witnessed the development of various new classes of anti-diabetic drugs with different pharmacokinetic and pharmacodynamic profiles. Details of their FDA approvals and advantages/disadvantages are summarized in this review.. The salient features of insulin degludec, sodium-glucose co-transporter 2 inhibitors, glucokinase activators, fibroblast growth factor 21 receptor agonists, and GLP-1 agonists are discussed.. In the future, these new anti-diabetic drugs may have broad clinical applicability. Additional multicenter clinical studies on these new drugs should be conducted. Topics: Animals; Diabetes Mellitus, Type 1; Diabetes Mellitus, Type 2; Enzyme Activators; Glucagon-Like Peptide 1; Humans; Hypoglycemic Agents; Insulin, Long-Acting; Receptors, Fibroblast Growth Factor | 2020 |
GIP analogues and the treatment of obesity-diabetes.
The potential application of glucose-dependent insulinotropic polypeptide (gastric inhibitory polypeptide, GIP) in the management of obesity and type 2 diabetes has been controversial. Initial interest in the therapeutic use of GIP was dampened by evidence that its insulinotropic activity was reduced in type 2 diabetes and by reports that it increased glucagon secretion and adipose deposition in non-diabetic individuals. Also, attention was diverted away from GIP by the successful development of glucagon-like peptide-1 (GLP-1) receptor agonists, and a therapeutic strategy for GIP became uncertain when evidence emerged that both inhibition and enhancement of GIP action could prevent or reverse obese non-insulin dependent forms of diabetes in rodents. Species differences in GIP receptor responsiveness complicated the extrapolation of evidence from rodents to humans, but initial clinical studies are investigating the effect of a GIP antagonist in non-diabetic individuals. A therapeutic role for GIP agonists was reconsidered when clinical studies noted that the insulinotropic effect of GIP was increased if near-normal glycaemia was re-established, and GIP was found to have little effect on glucagon secretion or adipose deposition in obese type 2 diabetes patients. This encouraged the development of designer peptides that act as GIP receptor agonists, including chimeric peptides that mimic the incretin partnership of GIP with GLP-1, where the two agents exert complementary and often additive effects to improve glycaemic control and facilitate weight loss. Polyagonist peptides that exert agonism at GIP, GLP-1 and glucagon receptors are also under investigation as potential treatments for obese type 2 diabetes. Topics: Animals; Diabetes Mellitus, Type 2; Gastric Inhibitory Polypeptide; Gastrointestinal Agents; Glucagon-Like Peptide 1; Humans; Obesity | 2020 |
Gastrointestinal peptides and nonalcoholic fatty liver disease.
In this review, authors have selected from literature the most recent and suggestive studies on therapy of nonalcoholic fatty liver disease (NAFLD). The selected interventions regulate the action of gastrointestinal peptides, such as gastric inhibitory polypeptide (GIP), nesfatin, peptide YY, cholecystokinin, and glucagon-like peptide 1 (GLP-1). These hormones have been found frequently modified in obesity and/or type 2 diabetes mellitus, morbidities mostly associated with NAFLD. This disease has a very high prevalence worldwide and could evolve in a more severe form, that is, nonalcoholic steatohepatitis, characterized by inflammation and fibrosis. The findings shown by this article describe the metabolic effects of new drugs, mainly but not only, as well of some old substances.. Recent approaches, in animal models or in humans, use synthetic GLP-1 receptor agonists, a centrally administered antibody neutralizing GIP receptor, curcumin, compound being active on nesfatin, resveratrol (antiinflammatory agent), and Ginseg, both of them acting on nesfatin, a cholecystokinin receptor analogue, and finally coffee functioning on YY peptide.. The implications of the presented findings, if they are confirmed in larger clinical trials, likely open the door to future application in clinical practice. In fact, nowadays, patients have only diet and article (incl abstract and keywords) exercise as well accepted recommendations. Thus, there are unmet needs to find substances that could really improve the progression of nonalcoholic steatohepatitis toward liver cirrhosis and hepatocellular carcinoma. Topics: Animals; Diabetes Mellitus, Type 2; Drugs, Investigational; Gastric Inhibitory Polypeptide; Gastrointestinal Tract; Glucagon-Like Peptide 1; Humans; Liver; Non-alcoholic Fatty Liver Disease; Obesity; Peptide Hormones; Peptide YY; Phytochemicals; Phytotherapy | 2020 |
Incretin therapy for diabetes mellitus type 2.
Among the gastrointestinal hormones, the incretins: glucose-dependent insulinotropic polypeptide and glucagon-like peptide-1 have attracted interest because of their importance for the development and therapy of type 2 diabetes and obesity. New agonists and formulations of particularly the GLP-1 receptor have been developed recently showing great therapeutic efficacy for both diseases.. The status of the currently available GLP-1 receptor agonists (GLP-1RAs) is described, and their strengths and weaknesses analyzed. Their ability to also reduce cardiovascular and renal risk is described and analysed. The most recent development of orally available agonists and of very potent monomolecular co-agonists for both the GLP-1 and GIP receptor is also discussed.. The GLP-1RAs are currently the most efficacious agents for weight loss, and show potential for further efficacy in combination with other food-intake-regulating peptides. Because of their glycemic efficacy and cardiorenal protection, the GLP-1 RAs will be prominent elements in future diabetes therapy. Topics: Blood Glucose; Diabetes Mellitus, Type 2; Glucagon-Like Peptide 1; Glucagon-Like Peptide-1 Receptor; Humans; Hypoglycemic Agents; Incretins; Kidney; Obesity; Treatment Outcome; Weight Loss | 2020 |
Physiologic Mechanisms of Type II Diabetes Mellitus Remission Following Bariatric Surgery: a Meta-analysis and Clinical Implications.
As obesity prevalence grows in the USA, metabolic syndrome is becoming increasingly more common. Current theories propose that insulin resistance is responsible for the hypertension, dyslipidemia, type II diabetes mellitus (T2DM), and low HDL that comprise metabolic syndrome. Bariatric surgery is one potential treatment, and its effects include permanently altering the patient's physiology and glucose regulation. Consequently, patients with T2DM who undergo bariatric surgery often experience tighter glucose control or remission of their T2DM altogether. This meta-analysis aims to explore the physiologic mechanisms underlying T2DM remission following bariatric surgery, which demonstrates effects that could lead to expansion of the NIH criteria for bariatric surgery candidates.. A comprehensive search was conducted in PubMed and Scopus. Two independent reviewers conducted title, abstract, and full text review of papers that met inclusion criteria. Papers that measured hormone levels before and after bariatric surgery were included in the meta-analysis. Weighted means and standard deviations were calculated for preoperative and postoperative GLP-1, GIP, ghrelin, and glucagon.. Total postprandial GLP-1 increased following bariatric surgery, which correlated with improvements in measures of glycemic control. Fasting GLP-1, fasting GIP, total postprandial GIP, total fasting ghrelin, and fasting glucagon all decreased, but all changes in hormones evaluated failed to reach statistical significance. Studies also demonstrated changes in hepatic and peripancreatic fat, inflammatory markers, miRNA, and gut microbiota following bariatric surgery.. While this meta-analysis sheds light on possible mechanisms, further studies are necessary to determine the dominant mechanism underlying remission of T2DM following bariatric surgery. Topics: Bariatric Surgery; Blood Glucose; Diabetes Mellitus, Type 2; Glucagon-Like Peptide 1; Humans; MicroRNAs; Obesity; Remission Induction | 2020 |
The Role of α-Cells in Islet Function and Glucose Homeostasis in Health and Type 2 Diabetes.
Pancreatic α-cells are the major source of glucagon, a hormone that counteracts the hypoglycemic action of insulin and strongly contributes to the correction of acute hypoglycemia. The mechanisms by which glucose controls glucagon secretion are hotly debated, and it is still unclear to what extent this control results from a direct action of glucose on α-cells or is indirectly mediated by β- and/or δ-cells. Besides its hyperglycemic action, glucagon has many other effects, in particular on lipid and amino acid metabolism. Counterintuitively, glucagon seems also required for an optimal insulin secretion in response to glucose by acting on its cognate receptor and, even more importantly, on GLP-1 receptors. Patients with diabetes mellitus display two main alterations of glucagon secretion: a relative hyperglucagonemia that aggravates hyperglycemia, and an impaired glucagon response to hypoglycemia. Under metabolic stress states, such as diabetes, pancreatic α-cells also secrete GLP-1, a glucose-lowering hormone, whereas the gut can produce glucagon. The contribution of extrapancreatic glucagon to the abnormal glucose homeostasis is unclear. Here, I review the possible mechanisms of control of glucagon secretion and the role of α-cells on islet function in healthy state. I discuss the possible causes of the abnormal glucagonemia in diabetes, with particular emphasis on type 2 diabetes, and I briefly comment the current antidiabetic therapies affecting α-cells. Topics: Animals; Diabetes Mellitus, Type 2; Glucagon; Glucagon-Like Peptide 1; Glucagon-Like Peptide-1 Receptor; Glucagon-Secreting Cells; Glucose; Humans; Hypoglycemia; Insulin | 2020 |
Glucagon and Glucagon-like Peptide-1 Receptors: Promising Therapeutic Targets for an Effective Management of Diabetes Mellitus.
G-protein-coupled receptors (GPCRs) are membrane-bound proteins, which are responsible for the detection of extracellular stimuli and the origination of intracellular responses. Both glucagon and glucagon-like peptide-1 (GLP-1) receptors belong to G protein-coupled receptor (GPCR) superfamily. Along with insulin, glucagon and GLP-1 are critical hormones for maintaining normal serum glucose within the human body. Glucagon generally plays its role in the liver through cyclic adenosine monophosphate (cAMP), where it compensates for the action of insulin. GLP-1 is secreted by the L-cells of the small intestine to stimulate insulin secretion and inhibit glucagon action. Despite extensive research efforts and the multiple approaches adopted, the glycemic control in the case of type-2 diabetes mellitus remains a major challenge. Therefore, a deep understanding of the structure-function relationship of these receptors will have great implications for future therapies in order to maintain a normal glucose level for an extended period of time. The antagonists of glucagon receptors that can effectively block the hepatic glucose production, as a result of glucagon action, are highly desirable for the tuning of the hyperglycemic state in type 2 diabetes mellitus. In the same manner, GLP-1R agonists act as important treatment modalities, thanks to their multiple anti-diabetic actions to attain normal glucose levels. In this review article, the structural diversity of glucagon and GLP-1 receptors along with their signaling pathways, site-directed mutations and significance in drug discovery against type-2 diabetes are illustrated. Moreover, the promising non-peptide antagonists of glucagon receptor and agonists of GLP-1 receptor, for the management of diabetes are presented with elaboration on the structure-activity relationship (SAR). Topics: Diabetes Mellitus, Type 2; Glucagon; Glucagon-Like Peptide 1; Glucagon-Like Peptide-1 Receptor; Humans; Receptors, Glucagon | 2020 |
Review on Chemistry, Analysis and Pharmacology of Teneligliptin: A Novel DPP-4 Inhibitor.
This article provides comprehensive and collective facts about teneligliptin. Teneligliptin is a dipeptide peptidase-4 (DPP-4) inhibitor that belongs to the third generation, used in the management of type 2 diabetes. It inhibits human DPP-4 enzyme activity. This drug falls under class 3; it interacts with S1, S2, and S2E extensive sub-sites. Teneligliptin and its metabolites are mainly determined in the human plasma matrix by hyphenated chromatographic methods. These developed methods could be foreseen for their clinical applications. Moreover, the stress degradation studies of Teneligliptin under different stress conditions provide an insight into degradation pathways and help in the elucidation of the structure of the degradation products by liquid mass spectroscopy. These methods are also used for routine quality control analysis of teneligliptin in pharmaceutical dosage forms. Topics: Blood Glucose; Cardiovascular Diseases; Diabetes Mellitus, Type 2; Dipeptidyl Peptidase 4; Dipeptidyl-Peptidase IV Inhibitors; Drug Interactions; Glucagon-Like Peptide 1; Half-Life; Humans; Pyrazoles; Thiazolidines | 2020 |
Recent advances in understanding the role of glucagon-like peptide 1.
The discovery that glucagon-like peptide 1 (GLP-1) mediates a significant proportion of the incretin effect during the postprandial period and the subsequent observation that GLP-1 bioactivity is retained in type 2 diabetes (T2D) led to new therapeutic strategies being developed for T2D treatment based on GLP-1 action. Although owing to its short half-life exogenous GLP-1 has no use therapeutically, GLP-1 mimetics, which have a much longer half-life than native GLP-1, have proven to be effective for T2D treatment since they prolong the incretin effect in patients. These GLP-1 mimetics are a desirable therapeutic option for T2D since they do not provoke hypoglycaemia or weight gain and have simple modes of administration and monitoring. Additionally, over more recent years, GLP-1 action has been found to mediate systemic physiological beneficial effects and this has high clinical relevance due to the post-diagnosis complications of T2D. Indeed, recent studies have found that certain GLP-1 analogue therapies improve the cardiovascular outcomes for people with diabetes. Furthermore, GLP-1-based therapies may enable new therapeutic strategies for diseases that can also arise independently of the clinical manifestation of T2D, such as dementia and Parkinson's disease. GLP-1 functions by binding to its receptor (GLP-1R), which expresses mainly in pancreatic islet beta cells. A better understanding of the mechanisms and signalling pathways by which acute and chronic GLP-1R activation alleviates disease phenotypes and induces desirable physiological responses during healthy conditions will likely lead to the development of new therapeutic GLP-1 mimetic-based therapies, which improve prognosis to a greater extent than current therapies for an array of diseases. Topics: Diabetes Mellitus, Type 2; Glucagon-Like Peptide 1; Glucagon-Like Peptide-1 Receptor; Humans; Hypoglycemic Agents; Incretins; Insulin-Secreting Cells | 2020 |
GLP-1 and insulin regulation of skeletal and cardiac muscle microvascular perfusion in type 2 diabetes.
Muscle microvasculature critically regulates skeletal and cardiac muscle health and function. It provides endothelial surface area for substrate exchange between the plasma compartment and the muscle interstitium. Insulin fine-tunes muscle microvascular perfusion to regulate its own action in muscle and oxygen and nutrient supplies to muscle. Specifically, insulin increases muscle microvascular perfusion, which results in increased delivery of insulin to the capillaries that bathe the muscle cells and then facilitate its own transendothelial transport to reach the muscle interstitium. In type 2 diabetes, muscle microvascular responses to insulin are blunted and there is capillary rarefaction. Both loss of capillary density and decreased insulin-mediated capillary recruitment contribute to a decreased endothelial surface area available for substrate exchange. Vasculature expresses abundant glucagon-like peptide 1 (GLP-1) receptors. GLP-1, in addition to its well-characterized glycemic actions, improves endothelial function, increases muscle microvascular perfusion, and stimulates angiogenesis. Importantly, these actions are preserved in the insulin resistant states. Thus, treatment of insulin resistant patients with GLP-1 receptor agonists may improve skeletal and cardiac muscle microvascular perfusion and increase muscle capillarization, leading to improved delivery of oxygen, nutrients, and hormones such as insulin to the myocytes. These actions of GLP-1 impact skeletal and cardiac muscle function and systems biology such as functional exercise capacity. Preclinical studies and clinical trials involving the use of GLP-1 receptor agonists have shown salutary cardiovascular effects and improved cardiovascular outcomes in type 2 diabetes mellitus. Future studies should further examine the different roles of GLP-1 in cardiac as well as skeletal muscle function.. 肌肉微血管系统对骨骼肌和心肌的健康和功能起着至关重要的调节作用。它为血浆间隙和肌肉间质之间的底物交换提供内皮表面积。胰岛素微调肌肉微血管灌注, 以调节自身在肌肉中的活动, 并为肌肉提供氧气和营养。具体地说, 胰岛素增加了肌肉微血管灌注, 使得更多的胰岛素转运到毛细血管周边的肌肉细胞, 然后通过其自身的透皮转运到达肌肉间质。在2型糖尿病中, 肌肉微血管对胰岛素的反应迟钝, 毛细血管稀疏。毛细血管密度的减少和胰岛素介导的毛细血管募集的降低, 都会导致可用于底物交换的内皮表面积减少。血管系统表达丰富的胰高血糖素样肽-1(GLP-1)受体。GLP-1可以改善内皮功能, 增加肌肉微血管灌注, 并刺激血管生成。重要的是, 这些作用在胰岛素抵抗状态下得以保留。因此, 使用GLP-1受体激动剂治疗胰岛素抵抗患者, 可能会改善骨骼肌和心肌微血管灌注, 增加肌肉的毛细血管, 从而改善氧、营养物质和胰岛素等激素向心肌细胞的输送。GLP-1的这些作用影响骨骼肌和心肌功能以及生物系统, 如功能性运动能力。涉及使用GLP-1受体激动剂的临床前研究和临床试验已经显示了有益的心血管效应, 并改善了2型糖尿病的心血管结局。未来的研究应该进一步研究GLP-1在心肌和骨骼肌功能中的不同作用. Topics: Coronary Vessels; Diabetes Mellitus, Type 2; Glucagon-Like Peptide 1; Glucagon-Like Peptide-1 Receptor; Heart; Humans; Hypoglycemic Agents; Insulin; Insulin Resistance; Muscle, Skeletal; Myocardium; Regional Blood Flow | 2020 |
[GLP-1 Analogs: Recommendations for Clinical Practice].
Topics: Blood Glucose; Diabetes Mellitus, Type 2; Glucagon-Like Peptide 1; Glucagon-Like Peptide-1 Receptor; Hypoglycemic Agents | 2020 |
The effects of dipeptidyl peptidase-4 inhibitors and glucagon-like peptide 1 receptor agonists on cognitive functions in adults with type 2 diabetes mellitus: a systematic review and meta-analysis.
The effects of dipeptidyl peptidase-4 inhibitors (DPP-4 inhibitors/DPP-4I) and glucagon-like peptide 1 receptor agonists (GLP-1 RA) on cognition in patients with type 2 diabetes mellitus (T2DM) remain controversial. We aimed to explore this clinical issue through a systematic review and meta-analysis.. PubMed, EMBASE and the Cochrane Library were searched, and data were expressed as mean difference (MD) or hazard ratio (HR)/odds ratio (OR) with a 95% confidence interval (CI). Heterogeneity was assessed using the Chi-squared test and the I. Eleven studies (n = 304,258 T2DM patients) were included in our review. In the DPP-4I group, six studies were enrolled to estimate ΔMini-Mental State Examination (MMSE) scores from baseline to the final evaluations after DPP-4I treatment, which showed no statistical difference (MD 0.20; 95% CI - 0.75 to 1.15, p = 0.68). ΔMMSE scores in the DPP-4I group and the other antidiabetic groups were compared, revealing no statistical difference (MD 0.57; 95% CI - 0.05 to 1.19, p = 0.07). Two cohort studies were pooled to determine the HRs for dementia, showing a lower risk of dementia after DPP-4I treatment (HR 0.52; 95% CI 0.29-0.93, p = 0.03). In the GLP-1 analogs group, two studies were included, one of which revealed a downward trend in the risk of dementia after GLP-1 analog treatment, while the other revealed no significant difference after incretins treatment.. Currently there is not enough irrefutable evidence to support the hypothesis of positive effects of incretins on cognition. Further clinical studies need to be performed. Topics: Adult; Cognition; Diabetes Mellitus, Type 2; Dipeptidyl-Peptidase IV Inhibitors; Glucagon-Like Peptide 1; Glucagon-Like Peptide-1 Receptor; Humans; Hypoglycemic Agents; Incretins | 2020 |
GLP-1 Analogs and DPP-4 Inhibitors in Type 2 Diabetes Therapy: Review of Head-to-Head Clinical Trials.
The incretin hormones glucagon-like peptide-1 (GLP-1) and glucose-dependent insulinotropic polypeptide (GIP) are released from enteroendocrine cells in response to the presence of nutrients in the small intestines. These homones facilitate glucose regulation by stimulating insulin secretion in a glucose dependent manner while suppressing glucagon secretion. In patients with type 2 diabetes (T2DM), an impaired insulin response to GLP-1 and GIP contributes to hyperglycemia. Dipeptidyl peptidase-4 (DPP-4) inhibitors block the breakdown of GLP-1 and GIP to increase levels of the active hormones. In clinical trials, DPP-4 inhibitors have a modest impact on glycemic control. They are generally well-tolerated, weight neutral and do not increase the risk of hypoglycemia. GLP-1 receptor agonists (GLP-1 RA) are peptide derivatives of either exendin-4 or human GLP-1 designed to resist the activity of DPP-4 and therefore, have a prolonged half-life. In clinical trials, they have demonstrated superior efficacy to many oral antihyperglycemic drugs, improved weight loss and a low risk of hypoglycemia. However, GI adverse events, particularly nausea, vomiting, and diarrhea are seen. Both DPP-4 inhibitors and GLP-1 RAs have demonstrated safety in robust cardiovascular outcome trials, while several GLP-1 RAs have been shown to significantly reduce the risk of major adverse cardiovascular events in persons with T2DM with pre-existing cardiovascular disease (CVD). Several clinical trials have directly compared the efficacy and safety of DPP-4 inhibitors and GLP-1 RAs. These studies have generally demonstrated that the GLP-1 RA provided superior glycemic control and weight loss relative to the DPP-4 inhibitor. Both treatments were associated with a low and comparable incidence of hypoglycemia, but treatment with GLP-1 RAs were invariably associated with a higher incidence of GI adverse events. A few studies have evaluated switching patients from DPP-4 inhibitors to a GLP-1RA and, as expected, improved glycemic control and weight loss are seen following the switch. According to current clinical guidelines, GLP-1RA and DPP-4 inhibitors are both indicated for the glycemic management of patients with T2DM across the spectrum of disease. GLP-1RA may be preferred over DPP- 4 inhibitors for many patients because of the greater reductions in hemoglobin A1c and weight loss observed in the clinical trials. Among patients with preexisting CVD, GLP-1 receptor agonists with a proven cardi Topics: Clinical Trials as Topic; Diabetes Mellitus, Type 2; Dipeptidyl-Peptidase IV Inhibitors; Drug-Related Side Effects and Adverse Reactions; Glucagon-Like Peptide 1; Humans; Hypoglycemic Agents | 2020 |
Can dipeptidyl peptidase-4 inhibitors treat cognitive disorders?
The linkage of neurodegenerative diseases with insulin resistance (IR) and type 2 diabetes mellitus (T2DM), including oxidative stress, mitochondrial dysfunction, excessive inflammatory responses and abnormal protein processing, and the correlation between cerebrovascular diseases and hyperglycemia has opened a new window for novel therapeutics for these cognitive disorders. Various antidiabetic agents have been studied for their potential treatment of cognitive disorders, among which the dipeptidyl peptidase-4 (DPP-4) inhibitors have been investigated more recently. So far, DPP-4 inhibitors have demonstrated neuroprotection and cognitive improvements in animal models, and cognitive benefits in diabetic patients with or without cognitive impairments. This review aims to summarize the potential mechanisms, advantages and limitations, and currently available evidence for developing DPP-4 inhibitors as a treatment of cognitive disorders. Topics: Animals; Cognitive Dysfunction; Diabetes Mellitus, Type 2; Dipeptidyl-Peptidase IV Inhibitors; Gastric Inhibitory Polypeptide; Gastrointestinal Microbiome; Glucagon-Like Peptide 1; Glucagon-Like Peptide-1 Receptor; Humans; Insulin Resistance | 2020 |
How May GIP Enhance the Therapeutic Efficacy of GLP-1?
Glucagon-like peptide-1 (GLP-1) receptor agonists improve glucose homeostasis, reduce bodyweight, and over time benefit cardiovascular health in type 2 diabetes mellitus (T2DM). However, dose-related gastrointestinal effects limit efficacy, and therefore agents possessing GLP-1 pharmacology that can also target alternative pathways may expand the therapeutic index. One approach is to engineer GLP-1 activity into the sequence of glucose-dependent insulinotropic polypeptide (GIP). Although the therapeutic implications of the lipogenic actions of GIP are debated, its ability to improve lipid and glucose metabolism is especially evident when paired with the anorexigenic mechanism of GLP-1. We review the complexity of GIP in regulating adipose tissue function and energy balance in the context of recent findings in T2DM showing that dual GIP/GLP-1 receptor agonist therapy produces profound weight loss, glycemic control, and lipid lowering. Topics: Adipose Tissue, White; Diabetes Mellitus, Type 2; Gastric Inhibitory Polypeptide; Glucagon-Like Peptide 1; Glucagon-Like Peptide-1 Receptor; Humans; Hypoglycemic Agents; Receptors, Gastrointestinal Hormone | 2020 |
Stroke in the patient with diabetes (Part 2) - Prevention and the effects of glucose lowering therapies.
There is a higher incidence of stroke in both the type 2 diabetic and the non-diabetic insulin resistant patient which is accompanied by higher morbidity and mortality. Stroke primary prevention can be achieved by controlling atrial fibrillation and hypertension, and the utilization of statins and anticoagulant therapies. Utilizing pioglitazone and GLP-1 receptor agonists reduce the risk of stroke while the utilization of metformin, α-glucosidase inhibitors, DPP-4 and SGLT-2 inhibitors have no effect. Insulin use may be a marker of increased risk of stroke, but not necessarily causative. Utilizing intravenous insulin to normalize plasma glucose levels in the acute phase of a stroke does not improve the outcome. Antiplatelet agents are not proven to be of benefit in primary prevention whereas the use of direct-acting oral anticoagulants to avoid stroke and the early use of tpA in the acute phase have been shown to be beneficial. Topics: Diabetes Mellitus, Type 2; Female; Glucagon-Like Peptide 1; Humans; Hypoglycemic Agents; Male | 2020 |
Combination gut hormones: prospects and questions for the future of obesity and diabetes therapy.
Obesity represents an important public health challenge for the twenty-first century: globalised, highly prevalent and increasingly common with time, this condition is likely to reverse some of the hard-won gains in mortality accomplished in previous centuries. In the search for safe and effective therapies for obesity and its companion, type 2 diabetes mellitus (T2D), the gut hormone glucagon-like peptide-1 (GLP-1) has emerged as a forerunner and analogues thereof are now widely used in treatment of obesity and T2D, bringing proven benefits in improving glycaemia and weight loss and, notably, cardiovascular outcomes. However, GLP-1 alone is subject to limitations in terms of efficacy, and as a result, investigators are evaluating other gut hormones such as glucose-dependent insulinotropic peptide (GIP), glucagon and peptide YY (PYY) as possible partner hormones that may complement and enhance GLP-1's therapeutic effects. Such combination gut hormone therapies are in pharmaceutical development at present and are likely to make it to market within the next few years. This review examines the physiological basis for combination gut hormone therapy and presents the latest clinical results that underpin the excitement around these treatments. We also pose, however, some hard questions for the field which need to be answered before the full benefit of such treatments can be realised. Topics: Animals; Diabetes Mellitus, Type 2; Gastric Inhibitory Polypeptide; Gastrointestinal Microbiome; Glucagon; Glucagon-Like Peptide 1; Humans; Obesity; Peptide YY | 2020 |
GIP as a Therapeutic Target in Diabetes and Obesity: Insight From Incretin Co-agonists.
The 2 hormones responsible for the amplification of insulin secretion after oral as opposed to intravenous nutrient administration are the gut peptides, glucagon-like peptide-1 (GLP-1) and glucose-dependent insulinotropic polypeptide (GIP). However, whereas GLP-1 also inhibits appetite and food intake and improves glucose regulation in patients with type 2 diabetes (T2DM), GIP seems to be devoid of these activities, although the 2 hormones as well as their receptors are highly related. In fact, numerous studies have suggested that GIP may promote obesity. However, chimeric peptides, combining elements of both peptides and capable of activating both receptors, have recently been demonstrated to have remarkable weight-losing and glucose-lowering efficacy in obese individuals with T2DM. At the same time, antagonists of the GIP receptor have been reported to reduce weight gain/cause weight loss in experimental animals including nonhuman primates. This suggests that both agonists and antagonist of the GIP receptor should be useful, at least for weight-losing therapy. How is this possible? We here review recent experimental evidence that agonist-induced internalization of the two receptors differs markedly and that modifications of the ligand structures, as in co-agonists, profoundly influence these cellular processes and may explain that an antagonist may activate while an agonist may block receptor signaling. Topics: Anti-Obesity Agents; Appetite; Blood Glucose; Diabetes Mellitus, Type 2; Gastric Inhibitory Polypeptide; Glucagon-Like Peptide 1; Humans; Hypoglycemic Agents; Incretins; Obesity; Receptors, Gastrointestinal Hormone; Signal Transduction; Weight Loss | 2020 |
Insights into incretin-based therapies for treatment of diabetic dyslipidemia.
Derangements in triglyceride and cholesterol metabolism (dyslipidemia) are major risk factors for the development of cardiovascular diseases in obese and type-2 diabetic (T2D) patients. An emerging class of glucagon-like peptide-1 (GLP-1) analogues and next generation peptide dual-agonists such as GLP-1/glucagon or GLP-1/GIP could provide effective therapeutic options for T2D patients. In addition to their role in glucose and energy homeostasis, GLP-1, GIP and glucagon serve as regulators of lipid metabolism. This review summarizes the current knowledge in GLP-1, glucagon and GIP effects on lipid and lipoprotein metabolism and frames the emerging therapeutic benefits of GLP-1 analogs and GLP-1-based multiagonists as add-on treatment options for diabetes associated dyslipidemia. Topics: Animals; Diabetes Mellitus, Type 2; Dipeptidyl-Peptidase IV Inhibitors; Dyslipidemias; Glucagon-Like Peptide 1; Glucagon-Like Peptide-1 Receptor; Humans; Incretins; Intestinal Mucosa; Lipid Metabolism; Lipoproteins | 2020 |
GLP-1 Analogues as a Complementary Therapy in Patients after Metabolic Surgery: a Systematic Review and Qualitative Synthesis.
The evidence is strong that bariatric surgery is superior to medical treatment in terms of weight loss and comorbidities in patients with severe obesity. However, a considerable part of patients presents with unsatisfactory response in the long term. It remains unclear whether postoperative administration of glucagon-like peptide-1 analogues can promote additional benefits. Therefore, a systematic review of the current literature on the management of postoperative GLP-1 analogue usage after metabolic surgery was performed. From 4663 identified articles, 6 met the inclusion criteria, but only one was a randomized controlled trial. The papers reviewed revealed that GLP-1 analogues may have beneficial effects on additional weight loss and T2D remission postoperatively. Thus, the use of GLP-1 analogues in addition to surgery promises good results concerning weight loss and improvements of comorbidities and can be used in patients with unsatisfactory results after bariatric surgery. Topics: Bariatric Surgery; Complementary Therapies; Diabetes Mellitus, Type 2; Glucagon-Like Peptide 1; Humans; Obesity, Morbid; Randomized Controlled Trials as Topic | 2020 |
Metformin monotherapy for adults with type 2 diabetes mellitus.
Worldwide, there is an increasing incidence of type 2 diabetes mellitus (T2DM). Metformin is still the recommended first-line glucose-lowering drug for people with T2DM. Despite this, the effects of metformin on patient-important outcomes are still not clarified.. To assess the effects of metformin monotherapy in adults with T2DM.. We based our search on a systematic report from the Agency for Healthcare Research and Quality, and topped-up the search in CENTRAL, MEDLINE, Embase, WHO ICTRP, and ClinicalTrials.gov. Additionally, we searched the reference lists of included trials and systematic reviews, as well as health technology assessment reports and medical agencies. The date of the last search for all databases was 2 December 2019, except Embase (searched up 28 April 2017).. We included randomised controlled trials (RCTs) with at least one year's duration comparing metformin monotherapy with no intervention, behaviour changing interventions or other glucose-lowering drugs in adults with T2DM.. Two review authors read all abstracts and full-text articles/records, assessed risk of bias, and extracted outcome data independently. We resolved discrepancies by involvement of a third review author. For meta-analyses we used a random-effects model with investigation of risk ratios (RRs) for dichotomous outcomes and mean differences (MDs) for continuous outcomes, using 95% confidence intervals (CIs) for effect estimates. We assessed the overall certainty of the evidence by using the GRADE instrument.. We included 18 RCTs with multiple study arms (N = 10,680). The percentage of participants finishing the trials was approximately 58% in all groups. Treatment duration ranged from one to 10.7 years. We judged no trials to be at low risk of bias on all 'Risk of bias' domains. The main outcomes of interest were all-cause mortality, serious adverse events (SAEs), health-related quality of life (HRQoL), cardiovascular mortality (CVM), non-fatal myocardial infarction (NFMI), non-fatal stroke (NFS), and end-stage renal disease (ESRD). Two trials compared metformin (N = 370) with insulin (N = 454). Neither trial reported on all-cause mortality, SAE, CVM, NFMI, NFS or ESRD. One trial provided information on HRQoL but did not show a substantial difference between the interventions. Seven trials compared metformin with sulphonylureas. Four trials reported on all-cause mortality: in three trials no participant died, and in the remaining trial 31/1454 participants (2.1%) in the metformin group died compared with 31/1441 participants (2.2%) in the sulphonylurea group (very low-certainty evidence). Three trials reported on SAE: in two trials no SAE occurred (186 participants); in the other trial 331/1454 participants (22.8%) in the metformin group experienced a SAE compared with 308/1441 participants (21.4%) in the sulphonylurea group (very low-certainty evidence). Two trials reported on CVM: in one trial no CVM was observed and in the other trial 4/1441 participants (0.3%) in the metformin group died of cardiovascular reasons compared with 8/1447 participants (0.6%) in the sulphonylurea group (very low-certainty evidence). Three trials reported on NFMI: in two trials no NFMI occurred, and in the other trial 21/1454 participants (1.4%) in the metformin group experienced a NFMI compared with 15/1441 participants (1.0%) in the sulphonylurea group (very low-certainty evidence). One trial reported no NFS occurred (very low-certainty evidence). No trial reported on HRQoL or ESRD. Seven trials compared metformin with thiazolidinediones (very low-certainty evidence for all outcomes). Five trials reported on all-cause mortality: in two trials no participant died; the overall RR was 0.88, 95% CI 0.55 to 1.39; P = 0.57; 5 trials; 4402 participants). Four trials reported on SAE, the RR was 0,95, 95% CI 0.84 to 1.09; P = 0.49; 3208 participants. Four trials reported on CVM, the RR was 0.71, 95% CI 0.21 to 2.39; P = 0.58; 3211 participants. Three trial reported on NFMI: in two trial. There is no clear evidence whether metformin monotherapy compared with no intervention, behaviour changing interventions or other glucose-lowering drugs influences patient-important outcomes. Topics: Adult; Carbamates; Cardiovascular Diseases; Cause of Death; Diabetes Mellitus, Type 2; Dipeptidyl-Peptidase IV Inhibitors; Glucagon-Like Peptide 1; Humans; Hypoglycemic Agents; Insulin; Metformin; Myocardial Infarction; Piperidines; Quality of Life; Randomized Controlled Trials as Topic; Stroke; Sulfonylurea Compounds | 2020 |
Pleiotropic effects of antidiabetic agents on renal and cardiovascular outcomes: a meta-analysis of randomized controlled trials.
This meta-analysis was conducted to examine the pleiotropic effects of all available antidiabetic agents except insulin for type 2 diabetes on renal and cardiovascular outcomes.. A systematic literature search was performed in PubMed, EMBASE, and Cochrane database to identify randomized-controlled trials which compared the effectiveness between all antidiabetic agents apart from insulin regarding all aspects of renal and cardiovascular outcomes. Random effect model was utilized to compute for hazard ratio.. Nineteen articles with 140,851 participants were included in this meta-analysis. When compared with placebo, SGLT-2 inhibitors, GLP-1 agonists, and DPP-4 inhibitors exhibited significantly lower hazard ratios of progression of albuminuria. SGLT-2 inhibitors and DPP-4 inhibitors showed a significantly higher hazard ratio of regression of albuminuria. Only SGLT-2 inhibitors illustrated significantly lower hazard ratios of doubling of serum creatinine and incidence of renal replacement therapy (RRT). A significantly lower hazard ratio of composite renal outcome was detected in both SGLT-2 inhibitors and GLP-1 agonists. A significantly lower hazard ratio of all-cause mortality was identified in SGLT-2 inhibitors and GLP-1 agonist. Furthermore, a significantly lower hazard ratio of cardiovascular mortality was found in both SGLT-2 inhibitors and GLP-1 agonists.. Comparing across all antidiabetic agents apart from insulin, SGLT-2 inhibitors provided extensively renoprotective effects among diabetic patients as well as reduced hazard ratios of heart failure, cardiovascular mortality, and all-cause mortality. GLP-1 agonists yielded benefits regarding progression of albuminuria, composite renal outcome, and cardiovascular and all-cause mortalities. DPP-4 inhibitors offered only renal protection including progression and regression of albuminuria. Topics: Cardiovascular System; Diabetes Mellitus, Type 2; Dipeptidyl-Peptidase IV Inhibitors; Glucagon-Like Peptide 1; Humans; Hypoglycemic Agents; Kidney; Randomized Controlled Trials as Topic; Sodium-Glucose Transporter 2 Inhibitors; Treatment Outcome | 2020 |
Potential roles of Glucagon-like peptide-1 and its analogues in cognitive impairment associated with type 2 diabetes mellitus.
Type 2 diabetes mellitus (T2DM) is a global disease that poses a significant threat to public health. The incidence of both diabetes and dementia has increased simultaneously. Researchers have found that a large proportion of dementia patients have T2DM. In recent years, increasing evidence has demonstrated a link between cognitive decline and T2DM. Although the exact pathogenesis of cognitive impairment in T2DM is still unknown, current studies suggest that hyperglycemia, cerebrovascular disease, brain insulin resistance, and changes in γ-aminobutyric acid (GABAergic) neurons may mediate the association between T2DM and cognitive impairment. These potential mechanisms may become targets for the treatment of cognitive disorders in patients with T2DM. Glucagon-like peptide-1 (GLP-1), a widely used anti-diabetic drug, has been shown to not only effectively lower blood glucose but also improve neurological function. Previous research has confirmed that GLP-1 and its analogues are effective in the treatment of cognitive impairment in patients with T2DM. This review describes current evidence on the mechanisms underlying the association between T2DM and cognitive impairment. In particular, this review focuses on recent advances in GLP-1 and its analogues for the treatment of T2DM-related cognitive impairment. Topics: Cognitive Dysfunction; Diabetes Mellitus, Type 2; Glucagon-Like Peptide 1; Humans; Incretins | 2020 |
Potential of Glucagon-Like Peptide 1 as a Regulator of Impaired Cholesterol Metabolism in the Brain.
Cerebral vascular diseases are the most common high-mortality diseases worldwide. Their onset and development are associated with glycemic imbalance, genetic background, alteration of atherosclerotic factors, severe inflammation, and abnormal cholesterol metabolism. Recently, the gut-brain axis has been highlighted as the key to the solution for cerebral vessel dysfunction in view of cholesterol metabolism and systemic lipid circulation. In particular, glucagon-like peptide 1 (GLP-1) is a cardinal hormone that regulates blood vessel function and cholesterol homeostasis and acts as a critical messenger between the brain and gut. GLP-1 plays a systemic regulatory role in cholesterol homeostasis and blood vessel function in various organs through blood vessels. Even though GLP-1 has potential in the treatment and prevention of cerebral vascular diseases, the importance of and relation between GLP-1 and cerebral vascular diseases are not fully understood. Herein, we review recent findings on the functions of GLP-1 in cerebral blood vessels in association with cholesterol metabolism. Topics: Animals; Brain; Cholesterol; Diabetes Mellitus, Type 2; Endothelial Cells; Glucagon-Like Peptide 1; Humans | 2020 |
The Mechanism of Metabolic Influences on the Endogenous GLP-1 by Oral Antidiabetic Medications in Type 2 Diabetes Mellitus.
Incretin-based therapy is now a prevalent treatment option for patients with type 2 diabetes mellitus (T2DM). It has been associated with considerably good results in the management of hyperglycemia with cardiac or nephron-benefits. For this reason, it is recommended for individuals with cardiovascular diseases in many clinical guidelines. As an incretin hormone, glucagon-like peptide-1 (GLP-1) possesses multiple metabolic benefits such as optimizing energy usage, maintaining body weight, Topics: Diabetes Mellitus, Type 2; Dipeptidyl-Peptidase IV Inhibitors; Glucagon-Like Peptide 1; Humans; Hypoglycemic Agents; Insulin-Secreting Cells | 2020 |
DOES EVOLUTIONARY BIOLOGY HELP THE UNDERSTANDING OF METABOLIC SURGERY? A FOCUSED REVIEW.
Vertical gastrectomy and different bowel functions. The wide net of physiological issues involved in metabolic surgery is extremely complex. Nonetheless, compared anatomy and phisiology can provide good clues of how digestive tracts are shaped for more or less caloric food, for more or less fiber, for abundance and for scarcity.. To review data from Compared Anatomy and Physiology, and in the Evolutionary Sciences that could help in the better comprehension of the metabolic surgery.. A focused review of the literature selecting information from these three fields of knowledge in databases: Cochrane Library, Medline and SciELO, articles and book chapters in English and Portuguese, between 1955 and 2019, using the headings "GIP, GLP-1, PYY, type 2 diabetes, vertebrates digestive system, hominid evolution, obesity, bariatric surgery ".. The digestive tract of superior animals shows highly specialized organs to digest and absorb specific diets. In spite of the wide variations of digestive systems, some general rules are observed. The proximal part of the digestive tract, facing the scarcity of sugars, is basically dedicated to generate sugar from different substrates (gluconeogenesis). Basic proximal gut tasks are to proportionally input free sugars, insulin, other fuels and to generate anabolic elements to the blood, some of them obesogenic. To limit the ingestion by satiety, by gastric emptying diminution and to limit the excessive elevation of major fuels (sugar and fat) in the blood are mostly the metabolict asks of the distal gut. A rapid and profound change in human diet composition added large amounts of high glycemic index foods. They seem to have caused an enhancement in the endocrine and metabolic activities of the proximal gut and a reduction in these activities of the distal gut. The most efficient models of metabolic surgery indeed make adjustments in this proximal/distal balance in the gut metabolic activities.. Metabolic surgery works basically by making adjustments to the proximal and distal gut metabolic activities that resemble the action of natural selection in the development the digestive systems of superior animals. Topics: Animals; Bariatric Surgery; Comprehension; Diabetes Mellitus, Type 2; Glucagon-Like Peptide 1; Humans; Obesity | 2020 |
Glucagon-like peptide 1 agonists for treatment of patients with type 2 diabetes who fail metformin monotherapy: systematic review and meta-analysis of economic evaluation studies.
To conduct a systematic review and meta-analysis and to pool the incremental net benefits (INBs) of glucagon-like peptide 1 (GLP1) compared with other therapies in type 2 diabetes mellitus (T2DM) after metformin monotherapy failure.. The study design is a systematic review and meta-analysis. We searched MEDLINE (via PubMed), Scopus and Tufts Registry for eligible cost-utility studies up to June 2018, adhering to the Preferred Reporting Items for Systematic Reviews and Meta-Analyses guideline. We conducted a systematic review and pooled the INBs of GLP1s compared with other therapies in T2DM after metformin monotherapy failure. Various monetary units were converted to purchasing power parity, adjusted to 2017 US$. The INBs were calculated and then pooled across studies, stratified by level of country income; a random-effects model was used if heterogeneity was present, and a fixed-effects model if it was absent. Heterogeneity was assessed using Q test and I. A total of 56 studies were eligible, mainly from high-income countries (HICs). The pooled INBs of GLP1s compared with dipeptidyl peptidase-4 inhibitor (DPP4i) (n=10), sulfonylureas (n=6), thiazolidinedione (TZD) (n=3), and insulin (n=23) from HICs were US$4012.21 (95% CI US$-571.43 to US$8595.84, I. GLP1 agonists are a cost-effective choice compared with insulins, but not compared with DPP4i, sulfonylureas and TZDs.. CRD42018105193. Topics: Cost-Benefit Analysis; Diabetes Mellitus, Type 2; Glucagon-Like Peptide 1; Humans; Hypoglycemic Agents; Metformin | 2020 |
Impact of glucagon-like peptide 1 receptor agonists and sodium-glucose transport protein 2 inhibitors on blood pressure and lipid profile.
Type 2 diabetes mellitus (T2DM) is associated with increased prevalence of cardiovascular (CV) disease (CVD). Optimal anti-hyperglycemic agents should include control of multiple CV risk factors (RF) to improve macrovascular and microvascular complications, as well as glycemia.. In this narrative review, the authors focus on the effects of glucagon-like peptide 1 receptor agonists (GLP-1 RA) and sodium-glucose transport protein 2 inhibitors (SGLT2i) on blood pressure (BP) and the lipid profile, two well-established CV RF.. Results from recent CV outcome trials (CVOTs), showed the impact of GLP-1 RA and SGLT2i on BP and lipid levels. These classes of medication can alter cardiac function by affecting the process of atherosclerosis and/or hemodynamic status. The results of published GLP1-RA and SGLT2i CVOTs have shown multifactorial benefits; in addition to the main effects on glycemia and body weight (BW), there are also positive but moderate effects on BP and lipid levels. Full advantage of the pleiotropic benefit of these agents should be taken to prevent CV events. Topics: Blood Glucose; Blood Pressure; Cardiovascular Diseases; Diabetes Mellitus, Type 2; Glucagon-Like Peptide 1; Glucagon-Like Peptide-1 Receptor; Humans; Hypoglycemic Agents; Lipids; Sodium-Glucose Transport Proteins; Sodium-Glucose Transporter 2 Inhibitors | 2020 |
Fighting Diabetes Mellitus: Pharmacological and Non-pharmacological Approaches.
The increasing worldwide prevalence of diabetes mellitus confers heavy public health issues and points to a large medical need for effective and novel anti-diabetic approaches with negligible adverse effects. Developing effective and novel anti-diabetic approaches to curb diabetes is one of the most foremost scientific challenges.. This article aims to provide an overview of current pharmacological and non-pharmacological approaches available for the management of diabetes mellitus.. Research articles that focused on pharmacological and non-pharmacological interventions for diabetes were collected from various search engines such as Science Direct and Scopus, using keywords like diabetes, glucagon-like peptide-1, glucose homeostasis, etc. Results: We review in detail several key pathways and pharmacological targets (e.g., the G protein-coupled receptors- cyclic adenosine monophosphate, 5'-adenosine monophosphate-activated protein kinase, sodium-glucose cotransporters 2, and peroxisome proliferator activated-receptor gamma signaling pathways) that are vital in the regulation of glucose homeostasis. The currently approved diabetes medications, the pharmacological potentials of naturally occurring compounds as promising interventions for diabetes, and the non-pharmacological methods designed to mitigate diabetes are summarized and discussed.. Pharmacological-based approaches such as insulin, metformin, sodium-glucose cotransporters 2 inhibitor, sulfonylureas, glucagon-like peptide-1 receptor agonists, and dipeptidyl peptidase IV inhibitors represent the most important strategies in diabetes management. These approved diabetes medications work via targeting the central signaling pathways related to the etiology of diabetes. Non-pharmacological approaches, including dietary modification, increased physical activity, and microbiota-based therapy are the other cornerstones for diabetes treatment. Pharmacological-based approaches may be incorporated when lifestyle modification alone is insufficient to achieve positive outcomes. Topics: Diabetes Mellitus, Type 2; Dipeptidyl-Peptidase IV Inhibitors; Glucagon-Like Peptide 1; Humans; Hypoglycemic Agents; Metformin | 2020 |
Long-acting GLP-1RAs: An overview of efficacy, safety, and their role in type 2 diabetes management.
Over recent decades, an improved understanding of the pathophysiology of type 2 diabetes mellitus (T2DM) and glucose regulation has led to innovative research and new treatment paradigms. The discovery of the gut peptide glucagon-like peptide-1 (GLP-1) and its role in glucose regulation paved the way for the class of GLP-1 receptor agonist compounds, or GLP-1RAs. The long-acting GLP-1RAs (dulaglutide, exenatide extended-release, liraglutide, semaglutide [injectable and oral]) are classified as such based on a minimum 24-hour duration of clinically relevant effects after administration. In phase 3 clinical trial programs of long-acting GLP-1RAs, A1C typically was reduced in the range of 1% to 1.5%, with reductions close to 2% in some studies. GLP-1RAs when used alone (without sulfonylureas or insulin) have a low risk of hypoglycemia because, like endogenous GLP-1, their insulinotropic effects are glucose-dependent. In addition to local actions in the gastrointestinal (GI) tract, GLP-1RAs stimulate receptors in the central nervous system to increase satiety, resulting in weight loss. All long-acting GLP-1RAs have, at minimum, been shown to be safe and not increase cardiovascular (CV) risk and most (liraglutide, semaglutide injectable, dulaglutide, albiglutide) have been shown in CV outcomes trials (CVOTs) to significantly reduce the risk of major cardiac adverse events. The class has good tolerability overall, with generally transient GI adverse events being most common. The weekly injectable agents offer scheduling convenience and may promote treatment adherence. One long-acting GLP-1RA is available as an oral daily tablet, which may be preferable for some patients and providers. Topics: Administration, Oral; Delayed-Action Preparations; Diabetes Mellitus, Type 2; Exenatide; Glucagon-Like Peptide 1; Glucagon-Like Peptide-1 Receptor; Glucagon-Like Peptides; Heart Disease Risk Factors; Humans; Immunoglobulin Fc Fragments; Injections; Liraglutide; Recombinant Fusion Proteins; Satiety Response; Weight Loss | 2020 |
Long-acting GLP-1 receptor agonists: Findings and implications of cardiovascular outcomes trials.
Cardiovascular disease (CVD) is a common and serious comorbidity of type 2 diabetes mellitus (T2DM), and cardiovascular (CV) risk assessment has become an important aspect of evaluating new therapies for T2DM before approval by the FDA. Since 2008, in order to establish safety, new therapies for T2DM have been required to demonstrate that they will not result in an unacceptable increase in CV risk. Studies performed for this purpose are termed CV outcome trials, or CVOTs. This article reviews CVOTs completed to date for the class of long-acting glucagon-like peptide-1 receptor agonists (GLP-1RAs; liraglutide, exenatide extended-release, albiglutide, dulaglutide, semaglutide injectable, semaglutide oral) and implications for clinical management of T2DM. All CVOTs have confirmed long-acting GLP-1RAs to be noninferior to (not worse than) placebo with regard to first occurrence of a primary outcome of three-point major adverse cardiovascular events (MACE; composite outcome of cardiovascular death, nonfatal myocardial infarction, nonfatal stroke). Further, a number of the studies demonstrated a statistically significant reduction in primary outcomes of three-point MACE with GLP-1RA treatment compared with placebo. As a result, the product labeling for liraglutide, semaglutide injectable, and dulaglutide has been updated with an indication for reducing the risk of MACE in adults with T2DM and established CVD (all) or multiple CV risk factors (dulaglutide only). These findings have brought about an exciting paradigm shift from concern about not inflicting CV harm to the exciting prospect of reducing risks of CV outcomes. Major diabetes care guidelines now encourage early consideration of GLP-1RA use in patients with atherosclerotic CVD. Topics: Administration, Oral; Cardiovascular Diseases; Delayed-Action Preparations; Diabetes Mellitus, Type 2; Exenatide; Glucagon-Like Peptide 1; Glucagon-Like Peptide-1 Receptor; Glucagon-Like Peptides; Heart Disease Risk Factors; Humans; Immunoglobulin Fc Fragments; Injections; Liraglutide; Practice Guidelines as Topic; Recombinant Fusion Proteins; Treatment Outcome; United States; United States Food and Drug Administration | 2020 |
Long-acting GLP-1RAs: An overview of efficacy, safety, and their role in type 2 diabetes management.
Over recent decades, an improved understanding of the pathophysiology of type 2 diabetes mellitus (T2DM) and glucose regulation has led to innovative research and new treatment paradigms. The discovery of the gut peptide glucagon-like peptide-1 (GLP-1) and its role in glucose regulation paved the way for the class of GLP-1 receptor agonist compounds, or GLP-1RAs. The long-acting GLP-1RAs (dulaglutide, exenatide extended-release, liraglutide, semaglutide [injectable and oral]) are classified as such based on a minimum 24-hour duration of clinically relevant effects after administration. In phase 3 clinical trial programs of long-acting GLP-1RAs, A1C typically was reduced in the range of 1% to 1.5%, with reductions close to 2% in some studies. GLP-1RAs when used alone (without sulfonylureas or insulin) have a low risk of hypoglycemia because, like endogenous GLP-1, their insulinotropic effects are glucose-dependent. In addition to local actions in the gastrointestinal (GI) tract, GLP-1RAs stimulate receptors in the central nervous system to increase satiety, resulting in weight loss. All long-acting GLP-1RAs have, at minimum, been shown to be safe and not increase cardiovascular (CV) risk and most (liraglutide, semaglutide injectable, dulaglutide, albiglutide) have been shown in CV outcomes trials (CVOTs) to significantly reduce the risk of major cardiac adverse events. The class has good tolerability overall, with generally transient GI adverse events being most common. The weekly injectable agents offer scheduling convenience and may promote treatment adherence. One long-acting GLP-1RA is available as an oral daily tablet, which may be preferable for some patients and providers. Topics: Administration, Oral; Delayed-Action Preparations; Diabetes Mellitus, Type 2; Glucagon-Like Peptide 1; Glucagon-Like Peptide-1 Receptor; Glucagon-Like Peptides; Glucose; Glycated Hemoglobin; Humans; Hypoglycemic Agents; Immunoglobulin Fc Fragments; Liraglutide; Recombinant Fusion Proteins; Safety; Treatment Outcome | 2020 |
Long-acting GLP-1 receptor agonists: Findings and implications of cardiovascular outcomes trials.
Cardiovascular disease (CVD) is a common and serious comorbidity of type 2 diabetes mellitus (T2DM), and cardiovascular (CV) risk assessment has become an important aspect of evaluating new therapies for T2DM before approval by the FDA. Since 2008, in order to establish safety, new therapies for T2DM have been required to demonstrate that they will not result in an unacceptable increase in CV risk. Studies performed for this purpose are termed CV outcome trials, or CVOTs. This article reviews CVOTs completed to date for the class of long-acting glucagon-like peptide-1 receptor agonists (GLP-1RAs; liraglutide, exenatide extended-release, albiglutide, dulaglutide, semaglutide injectable, semaglutide oral) and implications for clinical management of T2DM. All CVOTs have confirmed long-acting GLP-1RAs to be noninferior to (not worse than) placebo with regard to first occurrence of a primary outcome of three-point major adverse cardiovascular events (MACE; composite outcome of cardiovascular death, nonfatal myocardial infarction, nonfatal stroke). Further, a number of the studies demonstrated a statistically significant reduction in primary outcomes of three-point MACE with GLP-1RA treatment compared with placebo. As a result, the product labeling for liraglutide, semaglutide injectable, and dulaglutide has been updated with an indication for reducing the risk of MACE in adults with T2DM and established CVD (all) or multiple CV risk factors (dulaglutide only). These findings have brought about an exciting paradigm shift from concern about not inflicting CV harm to the exciting prospect of reducing risks of CV outcomes. Major diabetes care guidelines now encourage early consideration of GLP-1RA use in patients with atherosclerotic CVD. Topics: Cardiovascular Diseases; Delayed-Action Preparations; Diabetes Mellitus, Type 2; Exenatide; Glucagon-Like Peptide 1; Glucagon-Like Peptide-1 Receptor; Glucagon-Like Peptides; Heart Disease Risk Factors; Humans; Immunoglobulin Fc Fragments; Liraglutide; Recombinant Fusion Proteins; United States | 2020 |
A Review of Recent Findings on Meal Sequence: An Attractive Dietary Approach to Prevention and Management of Type 2 Diabetes.
While adjustment of total energy and nutritional balance is critically important, meal sequence, a relatively simple method of correcting postprandial hyperglycemia, is becoming established as a practical dietary approach for prevention and management of diabetes and obesity. Meal sequence, i.e., consumption of protein and/or fat before carbohydrate, promotes secretion of glucagon-like peptide-1 (GLP-1) from the gut and ameliorates secretions of insulin and glucagon and delays gastric emptying, thereby improving postprandial glucose excursion. GLP-1 is known to suppress appetite by acting on the hypothalamus via the afferent vagus nerve. Thus, enhancement of GLP-1 secretion by meal sequence is expected to reduce body weight. Importantly, consumption of a diet rich in saturated fatty acids such as meat dishes before carbohydrate increases secretions of not only GLP-1 but also glucose-dependent insulinotropic polypeptide (GIP), which promotes energy storage in adipose tissue and may lead to weight gain in the long term. Dietary fiber intake before carbohydrate intake significantly reduces postprandial glucose elevation and may have a weight loss effect, but this dietary strategy does not enhance the secretion of GLP-1. Thus, it is suggested that their combination may have additive effects on postprandial glucose excursion and body weight. Indeed, results of some clinical research supports the idea that ingesting dietary fiber together with meal sequence of protein and/or fat before carbohydrate benefits metabolic conditions of individuals with diabetes and obesity. Topics: Diabetes Mellitus, Type 2; Diet, Reducing; Dietary Carbohydrates; Dietary Fats; Dietary Fiber; Dietary Proteins; Feeding Behavior; Glucagon; Glucagon-Like Peptide 1; Humans; Insulin; Intestinal Mucosa; Meals; Nutritional Physiological Phenomena; Obesity | 2020 |
A look to the future in non-alcoholic fatty liver disease: Are glucagon-like peptide-1 analogues or sodium-glucose co-transporter-2 inhibitors the answer?
The increasing prevalence of diabetes and non-alcoholic fatty liver disease (NAFLD) is a growing public health concern associated with significant morbidity, mortality and economic cost, particularly in those who progress to cirrhosis. Medical treatment is frequently limited, with no specific licensed treatments currently available for people with NAFLD. Its association with diabetes raises the possibility of shared mechanisms of disease progression and treatment. With the ever-growing interest in the non-glycaemic effects of diabetes medications, studies and clinical trials have investigated hepatic outcomes associated with the use of drug classes used for people with type 2 diabetes (T2D), such as glucagon-like peptide-1 (GLP-1) analogues or sodium-glucose co-transporter-2 (SGLT2) inhibitors. Studies exploring the use of GLP-1 analogues or SGLT2 inhibitors in people with NAFLD have observed improved measures of hepatic inflammation, liver enzymes and radiological features over short periods. However, these studies tend to have variable study populations and inconsistent reported outcomes, limiting comparison between drugs and drug classes. As these drugs appear to improve biomarkers of NAFLD, clinicians should consider their use in patients with NAFLD and T2D. However, further evidence with greater participant numbers and longer trial durations is required to support specific licensing for people with NAFLD. Larger trials would allow reporting of major adverse hepatic events, akin to cardiovascular and renal outcome trials, to be determined. This would provide a more meaningful evaluation of the impact of these drugs in NAFLD. Nevertheless, these drugs represent a future potential therapeutic avenue in this difficult-to-treat population and may beget significant health and economic impacts. Topics: Diabetes Mellitus, Type 2; Glucagon-Like Peptide 1; Glucose; Humans; Non-alcoholic Fatty Liver Disease; Sodium; Sodium-Glucose Transporter 2 Inhibitors; Symporters | 2020 |
The Role of Dietary Fibre in Modulating Gut Microbiota Dysbiosis in Patients with Type 2 Diabetes: A Systematic Review and Meta-Analysis of Randomised Controlled Trials.
The prevalence of type 2 diabetes is on the increase worldwide, and it represents about 90% of adults who are diagnosed with diabetes. Overweight and obesity, lifestyle, genetic predisposition and gut microbiota dysbiosis have been implicated as possible risk factors in the development of type 2 diabetes. In particular, low intake of dietary fibre and consumption of foods high in fat and sugar, which are common in western lifestyle, have been reported to contribute to the depletion of specific bacterial taxa. Therefore, it is possible that intake of high dietary fibre may alter the environment in the gut and provide the needed substrate for microbial bloom.. The current review is a systematic review and meta-analysis which evaluated the role of dietary fibre in modulating gut microbiota dysbiosis in patients with type 2 diabetes.. This is a systematic review and meta-analysis of randomised controlled trials which relied on the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) framework. Electronic searches were conducted using EBSCOHost with links to Health Sciences Research Databases, EMBASE and Google Scholar. The reference lists of articles were also searched for relevant studies. Searches were conducted from date of commencement of the database to 5 August 2020. The search strategy was based on the Population, Intervention, Comparator, Outcomes, Studies (PICOS) framework and involved the use of synonyms and medical subject headings (MesH). Search terms were combined with Boolean operators (OR/AND).. Nine studies which met the inclusion criteria were selected for the systematic review and meta-analysis, and four distinct areas were identified: the effect of dietary fibre on gut microbiota; the role of dietary fibre on short-chain fatty acids (SCFAs); glycaemic control; and adverse events. There was significant difference (. This systematic review and meta-analysis have demonstrated that dietary fibre can significantly improve ( Topics: Adult; Diabetes Mellitus, Type 2; Dietary Fiber; Dysbiosis; Fatty Acids, Volatile; Female; Gastrointestinal Microbiome; Glucagon-Like Peptide 1; Glycated Hemoglobin; Glycemic Control; Humans; Male; Randomized Controlled Trials as Topic | 2020 |
Risk of Malignant Neoplasia with Glucagon-Like Peptide-1 Receptor Agonist Treatment in Patients with Type 2 Diabetes: A Meta-Analysis.
Glucagon-like peptide-1 (GLP-1) receptor agonists are effective glucose-lowering drugs, but there is concern that they may increase the risk of malignant neoplasia. The present meta-analysis examined the safety of GLP-1 receptor agonists with regard to malignant neoplasia.. We analyzed data from randomized controlled trials with a minimum duration of 24 weeks that assessed the incidence of neoplasms in type 2 diabetes patients receiving GLP-1 receptor agonists compared with placebo or other hypoglycemic drugs. We searched the MEDLINE, Embase, and Cochrane databases with a language restriction of English through October 1, 2018, and carried out a meta-analysis of the available trial data using a fixed effects model to calculate odds ratios (ORs) for neoplasia.. Thirty-four relevant articles, providing data for 50452 patients, were included in the meta-analysis. Compared with the incidence of malignant neoplasia with placebo or other interventions, no increase in malignant neoplasm formation was observed with the use of GLP-1 receptor agonists (OR 1.04, 95% confidence interval (CI) 0.94-1.15;. GLP-1 receptor agonists can be used without safety concerns related to malignant neoplasia in patients with type 2 diabetes. Topics: Diabetes Mellitus, Type 2; Exenatide; Glucagon-Like Peptide 1; Glucagon-Like Peptide-1 Receptor; Glucagon-Like Peptides; Humans; Hypoglycemic Agents; Incidence; Liraglutide; Neoplasms; Risk Factors | 2019 |
The Effects of Dual GLP-1/GIP Receptor Agonism on Glucagon Secretion-A Review.
The gut-derived incretin hormones glucagon-like peptide 1 (GLP-1) and glucose-dependent insulinotropic polypeptide (GIP) are secreted after meal ingestion and work in concert to promote postprandial insulin secretion. Furthermore, GLP-1 inhibits glucagon secretion when plasma glucose concentrations are above normal fasting concentrations while GIP acts glucagonotropically at low glucose levels. A dual incretin receptor agonist designed to co-activate GLP-1 and GIP receptors was recently shown to elicit robust improvements of glycemic control (mean haemoglobin A1c reduction of 1.94%) and massive body weight loss (mean weight loss of 11.3 kg) after 26 weeks of treatment with the highest dose (15 mg once weekly) in a clinical trial including overweight/obese patients with type 2 diabetes. Here, we describe the mechanisms by which the two incretins modulate alpha cell secretion of glucagon, review the effects of co-administration of GLP-1 and GIP on glucagon secretion, and discuss the potential role of glucagon in the therapeutic effects observed with novel unimolecular dual GLP-1/GIP receptor agonists. For clinicians and researchers, this manuscript offers an understanding of incretin physiology and pharmacology, and provides mechanistic insight into future antidiabetic and obesity treatments. Topics: Animals; Diabetes Mellitus, Type 2; Gastric Inhibitory Polypeptide; Glucagon; Glucagon-Like Peptide 1; Glucagon-Like Peptide-1 Receptor; Humans; Receptors, Gastrointestinal Hormone | 2019 |
Regulation of angiopoietin-like protein 8 expression under different nutritional and metabolic status.
Type 2 diabetes mellitus (T2DM) is a chronic metabolic disease with increasing prevalence worldwide. Angiopoietin-like protein 8 (ANGPTL8), a member of the angiopoietin-like protein family, is involved in glucose metabolism, lipid metabolism, and energy homeostasis and believed to be associated with T2DM. Expression levels of ANGPTL8 are often significantly altered in metabolic diseases, such as non-alcoholic fatty liver disease (NAFLD) and diabetes mellitus. Studies have shown that ANGPTL8, together with other members of this protein family, such as angiopoietin-like protein 3 (ANGPTL3) and angiopoietin-like protein 4 (ANGPTL4), regulates the activity of lipoprotein lipase (LPL), thereby participating in the regulation of triglyceride related lipoproteins (TRLs). In addition, members of the angiopoietin-like protein family are varyingly expressed among different tissues and respond differently under diverse nutritional and metabolic status. These findings may provide new options for the diagnosis and treatment of diabetes, metabolic syndromes and other diseases. In this review, the interaction between ANGPTL8 and ANGPTL3 or ANGPTL4, and the differential expression of ANGPTL8 responding to different nutritional and metabolic status during the regulation of LPL activity were reviewed. Topics: Angiopoietin-Like Protein 3; Angiopoietin-Like Protein 4; Angiopoietin-Like Protein 8; Angiopoietin-like Proteins; Animals; Diabetes Mellitus, Type 2; Gene Expression Regulation; Glucagon-Like Peptide 1; Glucose; Homeostasis; Humans; Insulin; Lipid Metabolism; Lipoprotein Lipase; Metabolic Diseases; Nutritional Status; Peptide Hormones | 2019 |
Effects of newer antidiabetic drugs on nonalcoholic fatty liver and steatohepatitis: Think out of the box!
Nonalcoholic fatty liver disease (NAFLD) is the most common chronic liver disease in Western societies and a major cause of hepatic disease worldwide. Its more severe type, namely nonalcoholic steatohepatitis (NASH), may result in the development of cirrhosis and hepatocellular carcinoma. NAFLD, and especially NASH, are also associated with increased cardiovascular morbidity and mortality. Type 2 diabetes mellitus (T2DM) predisposes to NAFLD development and progression via insulin resistance and hyperglycemia. It has also been reported that the majority of T2DM patients have NAFLD/NASH, thus potentially further increasing their cardiometabolic risk. Current guidelines recommend to screen for NAFLD in all T2DM patients and vice-versa. Lifestyle remains the first-line therapeutic option for NAFLD/NASH. Among antidiabetic drugs, pioglitazone was shown to improve histological features of NASH. More recently, there is an increasing interest regarding the effects of newer anti-diabetic drugs, such as dipeptidyl peptidase 4 inhibitors (DPP-4i), sodium glucose cotransporter 2 inhibitors (SGLT2i), and glucagon-like peptide-1 receptor agonists (GLP-1 RAs) on NAFLD/NASH. The present narrative review considers the up-to-date data on the impact of DPP-4i, SGLT2i, and GLP-1 RAs on biochemical and/or histological markers of NAFLD/NASH. The potential clinical implications of these findings in daily practice are also discussed. Taking into consideration the global increasing prevalence of NAFLD/NASH, therapeutic options that can prevent or treat this disease will exert considerable benefits on human health. Topics: Diabetes Mellitus, Type 2; Dipeptidyl-Peptidase IV Inhibitors; Fatty Liver; Glucagon-Like Peptide 1; Humans; Hypoglycemic Agents; Non-alcoholic Fatty Liver Disease; Pioglitazone; Sodium-Glucose Transporter 2 Inhibitors | 2019 |
Risk factor reduction in type 2 diabetes demands a multifactorial approach.
Dysglycaemia (i.e. type 2 diabetes mellitus or impaired glucose tolerance) is not only common in patients with cardiovascular disease but increases the risk for future cardiovascular complications. Hyperglycaemia, the hallmark of diabetes, has since long been considered to be the link between diabetes and cardiovascular disease. Diabetes is, however, a complex, multifactorial disorder to which, for example, insulin resistance, endothelial dysfunction and factors such as increased thrombogenicity, hypertension and dyslipidaemia contribute. Thus, treatment needs to be multifactorial and to take cardiovascular aspects into account. Life-style adjustments are, together with blood pressure, lipid and glucose control, important parts of such management. Recent trial data reveal a beneficial effect on cardiovascular prognosis and mortality of blood glucose lowering agents belonging to the classes: sodium-glucose-transporter 2 inhibitors and glucagon-like peptide 1 agonists. The precise mechanisms by which certain sodium-glucose-transporter 2 inhibitors and glucagon-like peptide receptor agonists lead to these beneficial effects are only partly understood. An important impact of the benefits of sodium-glucose-transporter 2 inhibitors is a reduction in heart failure while glucagon-like peptide receptor agonists may retard the development of atherosclerotic vascular disease or stabilising plaques. Although there has been a considerable improvement in the prognosis for people with atherosclerotic diseases over the last decades there is still a gap between those with dysglycaemia, who are at higher risk, than those without dysglycaemia. This residual risk is reasonably related to two major factors: a demand for improved management and a need for new and improved therapeutic opportunities of type 2 diabetes, both routes to an improved prognosis that are at hands. This review is a comprehensive description of the possibilities to improve the prognosis for patients with dysglycaemia by a multifactorial management according to the most recent European guidelines issued in 2019 by the European Society of Cardiology in collaboration with the European Association for the Study of Diabetes. Topics: Cardiovascular Diseases; Diabetes Mellitus, Type 2; Dyslipidemias; Europe; Glucagon-Like Peptide 1; Glucose Intolerance; Humans; Hypoglycemic Agents; Insulin Resistance; Practice Guidelines as Topic; Prognosis; Risk Factors; Risk Reduction Behavior; Sodium-Glucose Transporter 2 Inhibitors | 2019 |
Glucagon-like peptide 1 (GLP-1).
The glucagon-like peptide-1 (GLP-1) is a multifaceted hormone with broad pharmacological potential. Among the numerous metabolic effects of GLP-1 are the glucose-dependent stimulation of insulin secretion, decrease of gastric emptying, inhibition of food intake, increase of natriuresis and diuresis, and modulation of rodent β-cell proliferation. GLP-1 also has cardio- and neuroprotective effects, decreases inflammation and apoptosis, and has implications for learning and memory, reward behavior, and palatability. Biochemically modified for enhanced potency and sustained action, GLP-1 receptor agonists are successfully in clinical use for the treatment of type-2 diabetes, and several GLP-1-based pharmacotherapies are in clinical evaluation for the treatment of obesity.. In this review, we provide a detailed overview on the multifaceted nature of GLP-1 and its pharmacology and discuss its therapeutic implications on various diseases.. Since its discovery, GLP-1 has emerged as a pleiotropic hormone with a myriad of metabolic functions that go well beyond its classical identification as an incretin hormone. The numerous beneficial effects of GLP-1 render this hormone an interesting candidate for the development of pharmacotherapies to treat obesity, diabetes, and neurodegenerative disorders. Topics: Blood Glucose; Diabetes Mellitus, Type 2; Gastric Inhibitory Polypeptide; Glucagon-Like Peptide 1; Glucagon-Like Peptide-1 Receptor; Glucose; Humans; Hypoglycemic Agents; Insulin; Insulin Secretion; Insulin-Secreting Cells; Obesity; Receptors, Glucagon | 2019 |
[Glucagon-like peptide-1 (GLP1) and the gastrointestinal tract.
Glucagon-like peptide-1 (GLP1) and their receptor agonists - beside their blood glucose lowering and central effects- affect also the gastrointestinal function in many respects. They slow down the stomach emptying, the motility of the small bowel and colon - this is the explanation for the "ileal brake" terminology -, stimulate the function of exocrine pancreatic acinar cells and increase amylase production. GLP1 receptor agonists belong to the defining tools of the blood glucose lowering therapy in type 2 diabetes. Their long- and short-acting derivatives have different influence on the fasting and the postprandial blood glucose, respectively. By introducing the term non-prandial and prandial type analogues - which seems to be forced in light of the newer data - the potential slowdown in gastric emptying is the center of interest, lately, however, especially in the case of long-acting GLP1 variants, at least such attention should be paid to controlling bowel function. The article reviews the physiological effects of GLP1 on the gastrointestinal tract and draws attention to the potential for the prevention of possible side effects through detailed patient information and dietary advises. Orv Hetil. 2019; 160(49): 1927-1934.. Absztrakt: A glükagonszerű peptid-1 (GLP1) és receptoragonistái – a szénhidrát-anyagcserét érintő, valamint centrális, központi idegrendszeri hatásaik mellett – számos vonatkozásban érintik a gyomor-bél rendszer működését is. Lassítják a gyomor ürülését, a vékony- és vastagbél motilitását – az ileumperistaltica „fékezésére” utal az irodalmi összefoglalásokban szereplő „ileal brake” elnevezés –, serkentik az exocrin pancreas acinussejtjeinek működését és az amiláztermelést. A GLP1-receptor-agonisták napjainkban a 2-es típusú diabetes vércukorcsökkentő kezelésének meghatározó készítményei. A terápiás eszköztárába került hosszú, illetve rövid hatású változatok eltérően befolyásolják az éhomi és az étkezés utáni vércukorszintet. A készítmények ennek szem előtt tartásával történő – az újabb vizsgálatok fényében erőltetettnek ható – nem prandialis, illetve prandialis csoportosításával óhatatlanul a gyomorürülés befolyásolása került a figyelem előterébe, holott – különösen a hosszú hatású változatok esetében – legalább ilyen körültekintés szükséges a bélműködés vonatkozásában is. A közlemény áttekinti a GLP1 gastrointestinumot érintő élettani hatásait, és felhívja a figyelmet a lehetséges mellékhatások betegtájékoztatással és dietoterápiás módszerekkel történő megelőzési lehetőségeire. Orv Hetil. 2019; 160(49): 1927–1934. Topics: Blood Glucose; Diabetes Mellitus, Type 2; Glucagon-Like Peptide 1; Humans; Ileum; Intestine, Small; Postprandial Period | 2019 |
Targeting the DPP-4-GLP-1 pathway improves exercise tolerance in heart failure patients: a systematic review and meta-analysis.
The most significant manifestation of heart failure is exercise intolerance. This systematic review and meta-analysis was performed to investigate whether dipeptidyl peptidase-4 (DPP-4) inhibitors or glucagon-like peptide 1 receptor agonists (GLP-1 RAs), widely used anti-diabetic drugs, could improve exercise tolerance in heart failure patients with or without type 2 diabetes mellitus.. An electronic search of PubMed, EMBASE and the Cochrane Library was carried out through March 8th, 2019, for eligible trials. Only randomized controlled studies were included. The primary outcome was exercise tolerance [6-min walk test (6MWT) and peak O. After the literature was screened by two reviewers independently, four trials (659 patients) conducted with heart failure patients with or without type 2 diabetes met the eligibility criteria. The results suggested that targeting the DPP-4-GLP-1 pathway can improve exercise tolerance in heart failure patients [MD 24.88 (95% CI 5.45, 44.31), P = 0.01] without decreasing QoL [SMD -0.51 (95% CI -1.13, 0.10), P = 0.10]; additionally, targeting the DPP-4-GLP-1 pathway did not show signs of increasing the incidence of serious AEs or mortality.. Our results suggest that DPP-4 inhibitors or GLP-1 RAs improve exercise tolerance in heart failure patients. Although the use of these drugs for heart failure has not been approved by any organization, they may be a better choice for type 2 diabetes mellitus patients with heart failure. Furthermore, as this pathway contributes to the improvement of exercise tolerance, it may be worth further investigation in exercise-intolerant patients with other diseases. Topics: Aged; Diabetes Mellitus, Type 2; Dipeptidyl Peptidase 4; Dipeptidyl-Peptidase IV Inhibitors; Exercise Tolerance; Female; Glucagon-Like Peptide 1; Glucagon-Like Peptide-1 Receptor; Heart Failure; Humans; Incretins; Male; Middle Aged; Quality of Life; Randomized Controlled Trials as Topic; Recovery of Function; Signal Transduction; Treatment Outcome | 2019 |
Glucose-Responsive Microneedle Patches for Diabetes Treatment.
Antidiabetic therapeutics, including insulin as well as glucagon-like peptide 1 (GLP-1) and its analogs, are essential for people with diabetes to regulate their blood glucose levels. Nevertheless, conventional treatments based on hypodermic administration is commonly associated with poor blood glucose control, a lack of patient compliance, and a high risk of hypoglycemia. Closed-loop drug delivery strategies, also known as self-regulated administration, which can intelligently govern the drug release kinetics in response to the fluctuation in blood glucose levels, show tremendous promise in diabetes therapy. In the meantime, the advances in the development and use of microneedle (MN)-array patches for transdermal drug delivery offer an alternative method to conventional hypodermic administration. Hence, glucose-responsive MN-array patches for the treatment of diabetes have attracted increasing attentions in recent years. This review summarizes recent advances in glucose-responsive MN-array patch systems. Their opportunities and challenges for clinical translation are also discussed. Topics: Animals; Blood Glucose; Blood Glucose Self-Monitoring; Diabetes Mellitus, Type 1; Diabetes Mellitus, Type 2; Glucagon-Like Peptide 1; Glucose; Humans; Hydrogen Peroxide; Hydrogen-Ion Concentration; Hypoglycemic Agents; Insulin Infusion Systems; Insulin-Secreting Cells; Kinetics; Needles; Transdermal Patch; Translational Research, Biomedical | 2019 |
New Avenues in the Regulation of Gallbladder Motility-Implications for the Use of Glucagon-Like Peptide-Derived Drugs.
Several cases of cholelithiasis and cholecystitis have been reported in patients treated with glucagon-like peptide 1 (GLP-1) receptor agonists (GLP-1RAs) and GLP-2 receptor agonists (GLP-2RAs), respectively. Thus, the effects of GLP-1 and GLP-2 on gallbladder motility have been investigated. We have provided an overview of the mechanisms regulating gallbladder motility and highlight novel findings on the effects of bile acids and glucagon-like peptides on gallbladder motility.. The articles included in the present review were identified using electronic literature searches. The search results were narrowed to data reporting the effects of bile acids and GLPs on gallbladder motility.. Bile acids negate the effect of postprandial cholecystokinin-mediated gallbladder contraction. Two bile acid receptors seem to be involved in this feedback mechanism, the transmembrane Takeda G protein-coupled receptor 5 (TGR5) and the nuclear farnesoid X receptor. Furthermore, activation of TGR5 in enteroendocrine L cells leads to release of GLP-1 and, possibly, GLP-2. Recent findings have pointed to the existence of a bile acid-TGR5-L cell-GLP-2 axis that serves to terminate meal-induced gallbladder contraction and thereby initiate gallbladder refilling. GLP-2 might play a dominant role in this axis by directly relaxing the gallbladder. Moreover, recent findings have suggested GLP-1RA treatment prolongs the refilling phase of the gallbladder.. GLP-2 receptor activation in rodents acutely increases the volume of the gallbladder, which might explain the risk of gallbladder diseases associated with GLP-2RA treatment observed in humans. GLP-1RA-induced prolongation of human gallbladder refilling may explain the gallbladder events observed in GLP-1RA clinical trials. Topics: Bile Acids and Salts; Cholecystitis; Cholecystokinin; Cholelithiasis; Diabetes Mellitus, Type 2; Gallbladder; Gallbladder Emptying; Glucagon-Like Peptide 1; Glucagon-Like Peptide 2; Glucagon-Like Peptide-1 Receptor; Glucagon-Like Peptide-2 Receptor; Glucagon-Like Peptides; Humans; Muscle Contraction; Muscle, Smooth; Obesity; Postprandial Period | 2019 |
Glucagon-like peptide-1 receptor agonists in type 2 diabetes treatment: are they all the same?
Glucagon-like peptide-1 (GLP-1) receptor agonists (RAs) are an important class of drugs with a well-established efficacy and safety profile in patients with type 2 diabetes mellitus. Agents in this class are derived from either exendin-4 (a compound present in Gila monster venom) or modifications of human GLP-1 active fragment. Differences among these drugs in duration of action (ie, short-acting vs long-acting), effects on glycaemic control and weight loss, immunogenicity, tolerability profiles, and administration routes offer physicians several options when selecting the most appropriate agent for individual patients. Patient preference is also an important consideration. The aim of this review is to discuss the differences between and similarities of GLP-1 RAs currently approved for clinical use, focusing particularly on the properties characterising the single short-acting and long-acting GLP-1 RAs rather than on their individual efficacy and safety profiles. The primary pharmacodynamic difference between short-acting (ie, exenatide twice daily and lixisenatide) and long-acting (ie, albiglutide, dulaglutide, exenatide once weekly, liraglutide, and semaglutide) GLP-1 RAs is that short-acting agents primarily delay gastric emptying (lowering postprandial glucose) and long-acting agents affect both fasting glucose (via enhanced glucose-dependent insulin secretion and reduced glucagon secretion in the fasting state) and postprandial glucose (via enhanced postprandial insulin secretion and inhibition of glucagon secretion). Other advantages of long-acting GLP-1 RAs include smaller fluctuations in plasma drug concentrations, improved gastrointestinal tolerability profiles, and simpler, more convenient administration schedules (once daily for liraglutide and once weekly for albiglutide, dulaglutide, the long-acting exenatide formulation, and semaglutide), which might improve treatment adherence and persistence. Topics: Diabetes Mellitus, Type 2; Exenatide; Glucagon-Like Peptide 1; Glucagon-Like Peptide-1 Receptor; Glucagon-Like Peptides; Humans; Hypoglycemic Agents; Immunoglobulin Fc Fragments; Recombinant Fusion Proteins; Treatment Outcome | 2019 |
Glucagon-like peptide-1 receptor action in the vasculature.
Glucagon-like peptide-1 receptor (GLP-1R) agonists augment insulin secretion and are thus used clinically to improve glycemia in subjects with type 2 diabetes (T2D). As recent data reveal marked improvements in cardiovascular outcomes in T2D subjects treated with the GLP-1R agonists liraglutide and semaglutide in the LEADER and SUSTAIN-6 clinical trials respectively, there is growing interest in delineating the mechanism(s) of action for GLP-1R agonist-induced cardioprotection. Of importance, negligible GLP-1R expression in ventricular cardiac myocytes suggests that cardiac-independent actions of GLP-1R agonists may account for the reduced death rates from cardiovascular causes in T2D subjects enrolled in the LEADER trial. Conversely, vascular smooth muscle cells (VSMCs) appear to express the canonical GLP-1R, and GLP-1/GLP-1R agonists exhibit a number of salutary actions on the vascular endothelium that could potentially contribute to GLP-1R agonists directly improving cardiovascular outcomes in subjects with T2D. We review herein the described actions of GLP-1/GLP-1R agonists on the vascular endothelium, which include antiproliferative actions on VSMCs and endothelial cells, reductions in oxidative stress, and increases in nitric oxide generation. GLP-1 also increases microvascular recruitment and microvascular blood flow. Taken together, such actions may explain the antihypertensive and/or antiatherosclerotic actions attributed to GLP-1/GLP-1R agonists in preclinical and clinical studies. Nonetheless, further mechanistic studies are still necessary to determine the relative importance of such actions in accounting for reductions in macrovascular cardiovascular disease in human subjects with T2D treated with GLP-1R agonists. Topics: Animals; Clinical Trials as Topic; Diabetes Mellitus, Type 2; Endothelium, Vascular; Glucagon-Like Peptide 1; Glucagon-Like Peptide-1 Receptor; Glucagon-Like Peptides; Humans; Liraglutide | 2019 |
Emerging hormonal-based combination pharmacotherapies for the treatment of metabolic diseases.
Obesity and its comorbidities, such as type 2 diabetes mellitus and cardiovascular disease, constitute growing challenges for public health and economies globally. The available treatment options for these metabolic disorders cannot reverse the disease in most individuals and have not substantially reduced disease prevalence, which underscores the unmet need for more efficacious interventions. Neurobiological resilience to energy homeostatic perturbations, combined with the heterogeneous pathophysiology of human metabolic disorders, has limited the sustainability and efficacy of current pharmacological options. Emerging insights into the molecular origins of eating behaviour, energy expenditure, dyslipidaemia and insulin resistance suggest that coordinated targeting of multiple signalling pathways is probably necessary for sizeable improvements to reverse the progression of these diseases. Accordingly, a broad set of combinatorial approaches targeting feeding circuits, energy expenditure and glucose metabolism in concert are currently being explored and developed. Notably, several classes of peptide-based multi-agonists and peptide-small molecule conjugates with superior preclinical efficacy have emerged and are currently undergoing clinical evaluation. Here, we summarize advances over the past decade in combination pharmacotherapy for the management of obesity and type 2 diabetes mellitus, exclusively focusing on large-molecule formats (notably enteroendocrine peptides and proteins) and discuss the associated therapeutic opportunities and challenges. Topics: Animals; Body Mass Index; Diabetes Mellitus, Type 2; Drug Administration Schedule; Drug Therapy, Combination; Female; Gastrins; Gastrointestinal Hormones; Glucagon-Like Peptide 1; Humans; Male; Metabolic Diseases; Metformin; Mice; Molecular Targeted Therapy; Obesity; Prognosis; Risk Assessment; Sodium-Glucose Transporter 2 Inhibitors; Treatment Outcome | 2019 |
Cracking the combination: Gut hormones for the treatment of obesity and diabetes.
Obesity and type 2 diabetes are a veritable global pandemic. There is an imperative to develop new therapies for these conditions that can be delivered at scale to patients, which deliver effective and titratable weight loss, amelioration of diabetes, prevention of diabetic complications and improvements in cardiovascular health. Although agents based on glucagon-like peptide-1 (GLP-1) are now in routine use for diabetes and obesity, the limited efficacy of such drugs means that newer agents are required. By combining the effects of GLP-1 with other gut and metabolic hormones such as glucagon (GCG), oxyntomodulin, glucose-dependent insulinotropic peptide (GIP) and peptide YY (PYY), we may obtain improved weight loss, increased energy expenditure and improved metabolic profiles. Drugs based on dual agonism of GLP1R/GCGR and GLP1R/GIPR are being actively developed in clinical trials. Triple agonism, for example with GLPR1/GCGR/GIPR unimolecular agonists or using GLP-1/oxyntomodulin/PYY, is also being explored. Multi-agonist drugs seem set to deliver the next generation of therapies for diabetes and obesity soon. Topics: Animals; Diabetes Mellitus, Type 2; Gastrointestinal Hormones; Glucagon-Like Peptide 1; Humans; Obesity; Weight Loss | 2019 |
Diabetes Care for Patients Experiencing Homelessness: Beyond Metformin and Sulfonylureas.
On any given night in the United States, an estimated 553,742 people are homeless. Applying a broader definition of homelessness that includes unstably housed people, an estimated 1.5% of Americans experience homelessness in a given year. Rates of diabetes are increasing among individuals experiencing homelessness. The social, psychological, and physical challenges of homelessness not only contribute to the rate of diabetes, but also complicate management. Unstable housing, limited medical resources, food insecurity, and competing priorities are barriers to diabetes care among patients experiencing homelessness. Homeless patients with diabetes more frequently develop specific comorbidities that require special attention, such as cardiovascular disease, substance abuse, depression, and foot wounds. The Affordable Care Act gave states the option to expand Medicaid to those earning up to 138% of the federal poverty level. This addressed a gap in coverage for low-income individuals not eligible for Medicaid or employer-sponsored insurance. With increased insurance coverage, this has increased the variety of medications available to treat hyperglycemia from type 2 diabetes beyond metformin, sulfonylureas, and insulin. Several of the newer classes of medications have advantages for patients experiencing homelessness, but also have special considerations in this vulnerable patient population. This narrative review will provide a review of dipeptidyl peptidase-4 inhibitors, glucagon-like peptide agonists, sodium glucose cotransporter-2 inhibitors, and thiazolidinediones in individuals experiencing homelessness. Topics: Diabetes Mellitus, Type 2; Dipeptidyl-Peptidase IV Inhibitors; Glucagon-Like Peptide 1; Humans; Hypoglycemic Agents; Ill-Housed Persons; Pioglitazone; PPAR gamma; Sodium-Glucose Transporter 2 Inhibitors | 2019 |
Browning of white fat: agents and implications for beige adipose tissue to type 2 diabetes.
Mammalian adipose tissue is traditionally categorized into white and brown relating to their function and morphology: while white serves as an energy storage, brown adipose tissue acts as the heat generator maintaining the core body temperature. The most recently identified type of fat, beige adipocyte tissue, resembles brown fat by morphology and function but is developmentally more related to white. The synthesis of beige fat, so-called browning of white fat, has developed into a topical issue in diabetes and metabolism research. This is due to its favorable effect on whole-body energy metabolism and the fact that it can be recruited during adult life. Indeed, brown and beige adipose tissues have been demonstrated to play a role in glucose homeostasis, insulin sensitivity, and lipid metabolism-all factors related to pathogenesis of type 2 diabetes. Many agents capable of initiating browning have been identified so far and tested widely in humans and animal models including in vitro and in vivo experiments. Interestingly, several agents demonstrated to have browning activity are in fact secreted as adipokines from brown and beige fat tissue, suggesting a physiological relevance both in beige adipocyte recruitment processes and in maintenance of metabolic homeostasis. The newest findings on agents driving beige fat recruitment, their mechanisms, and implications on type 2 diabetes are discussed in this review. Topics: Adipose Tissue, Beige; Adipose Tissue, Brown; Adipose Tissue, White; Animals; Diabetes Mellitus, Type 2; Energy Metabolism; Glucagon-Like Peptide 1; Glucose; Humans; Insulin Resistance; Leptin; Lipid Metabolism; Lipotropic Agents; Melatonin; Natriuretic Peptides; Thermogenesis; Tretinoin | 2019 |
Fracture Risk After Initiation of Use of Canagliflozin: A Cohort Study.
Sodium-glucose cotransporter-2 inhibitors promote glycosuria, resulting in possible effects on calcium, phosphate, and vitamin D homeostasis. Canagliflozin is associated with decreased bone mineral density and a potential increased risk for fracture.. To estimate risk for nonvertebral fracture among new users of canagliflozin compared with a glucagon-like peptide-1 (GLP-1) agonist.. Population-based new-user cohort study.. Two U.S. commercial health care databases providing data on more than 70 million patients from March 2013 to October 2015.. Persons with type 2 diabetes who initiated use of canagliflozin were propensity score-matched in a 1:1 ratio to those initiating use of a GLP-1 agonist.. The primary outcome was a composite end point of humerus, forearm, pelvis, or hip fracture requiring intervention. Secondary outcomes included fractures at other sites. A fixed-effects meta-analysis that pooled results from the 2 databases provided an overall hazard ratio (HR).. 79 964 patients initiating use of canagliflozin were identified and matched to 79 964 patients initiating use of a GLP-1 agonist. Mean age was 55 years, 48% were female, average baseline hemoglobin A1c level was 8.7%, and 27% were prescribed insulin. The rate of the primary outcome was similar for canagliflozin (2.2 events per 1000 person-years) and GLP-1 agonists (2.3 events per 1000 person-years), with an overall HR of 0.98 (95% CI, 0.75 to 1.26). Risk for pelvic, hip, humerus, radius, ulna, carpal, metacarpal, metatarsal, or ankle fracture was also similar for canagliflozin (14.5 events per 1000 person-years) and GLP-1 agonists (16.1 events per 1000 person-years) (overall HR, 0.92 [CI, 0.83 to 1.02]).. Unmeasured confounding, measurement error, and low fracture rate.. In this study of middle-aged patients with type 2 diabetes and relatively low fracture risk, canagliflozin was not associated with increased risk for fracture compared with GLP-1 agonists.. Brigham and Women's Hospital, Division of Pharmacoepidemiology and Pharmacoeconomics. Topics: Aged; Canagliflozin; Diabetes Mellitus, Type 2; Female; Follow-Up Studies; Fractures, Bone; Glucagon-Like Peptide 1; Humans; Hypoglycemic Agents; Longitudinal Studies; Male; Middle Aged; Propensity Score; Proportional Hazards Models; Risk Assessment; Sodium-Glucose Transporter 2 Inhibitors | 2019 |
Optimizing Fixed-Ratio Combination Therapy in Type 2 Diabetes.
The progressive nature of type 2 diabetes (T2D) means that many patients will require basal insulin therapy at some point in the course of the disease due to β-cell failure. As basal insulin primarily targets fasting plasma glucose, patients may still experience considerable postprandial glucose excursions and therefore require an additional agent to achieve good glycemic control. Glucagon-like peptide-1 receptor agonists (GLP-1 RAs) provide an alternative to prandial insulin, with the benefits of fewer daily injections, and a lower risk of hypoglycemia and weight gain. Two fixed-ratio combinations (FRCs) of basal insulin and a GLP-1 RA are now available in the USA and the EU: insulin glargine + lixisenatide (iGlarLixi) and insulin degludec + liraglutide (IDegLira). Titratable FRCs are suitable for most patients with T2D and can help to simplify treatment regimens into one daily injection, potentially aiding in patient adherence. The complementary modes of action of the two components target seven of the many known pathophysiologic defects in T2D. FRCs have demonstrated enhanced glycemic control compared with their constituent components alone, comparable risk of hypoglycemia compared with basal insulin alone, and better tolerability compared with the GLP-1RA component alone due to the slower titration. In this article, we discuss the advantages of FRCs over multiple daily injections, present case studies of typical patients who could benefit from FRC therapy, and outline practical considerations for the initiation of FRC therapy in clinical practice.Funding Sanofi. Topics: Combined Modality Therapy; Diabetes Mellitus, Type 2; Drug Combinations; Glucagon-Like Peptide 1; Glucagon-Like Peptide-1 Receptor; Glycated Hemoglobin; Humans; Hypoglycemic Agents; Insulin; Insulin, Long-Acting; Liraglutide; Patient Compliance; Postprandial Period; Weight Gain | 2019 |
The effect of sodium-glucose cotransporter 2 inhibitors and glucagon-like peptide 1 agonists on cardiovascular disease in patients with type 2 diabetes.
Patients with type 2 diabetes have a significantly increased risk of cardiovascular disease (CVD) compared to the general population-with CVD accounting for two out of every three deaths in patients with diabetes. In 2008, the FDA suggested that CVD risk should be evaluated for any new antidiabetic therapy, leading to a multitude of large CVD outcome trials to assess CVD risk from these medications. Interestingly, several of these outcome trials with new novel antidiabetic therapies have demonstrated a clear and definite CVD advantage at mid-term follow up in high-risk patients with T2DM. In this review, we discuss two relatively new classes of diabetic drugs, sodium-glucose cotransporter 2 inhibitors and glucagon-like peptide 1 agonists, and their efficacy in improving cardiovascular outcomes. Topics: Cardiovascular Diseases; Diabetes Mellitus, Type 2; Global Health; Glucagon-Like Peptide 1; Humans; Hypoglycemic Agents; Incidence; Prognosis; Secondary Prevention; Sodium-Glucose Transporter 2 Inhibitors; Survival Rate | 2019 |
Cigarette smoking, type 2 diabetes mellitus, and glucagon-like peptide-1 receptor agonists as a potential treatment for smokers with diabetes: An integrative review.
Tobacco use disorder (TUD), in particular cigarette smoking, contributes significantly to the macro- and micro-vascular complications of type 2 diabetes mellitus (DM). Persons with DM who regularly use tobacco products are twice as likely to experience mortality and negative health outcomes. Despite these risks, TUD remains prevalent in persons with DM. The objective of this integrative review is to summarize the relationship between TUD and DM based on epidemiological and preclinical biological evidence. We conclude with a review of the literature on the glucagon-like peptide-1 (GLP-1) as a potential treatment target for addressing comorbid TUD in smokers with DM. Topics: Cigarette Smoking; Diabetes Mellitus, Type 2; Glucagon-Like Peptide 1; Glucagon-Like Peptide-1 Receptor; Humans; Hypoglycemic Agents | 2019 |
The Impact of Comorbidities on the Pharmacological Management of Type 2 Diabetes Mellitus.
Diabetes mellitus affects over 20% of people aged > 65 years. With the population of older people living with diabetes growing, the condition may be only one of a number of significant comorbidities that increases the complexity of their care, reduces functional status and inhibits their ability to self-care. Coexisting comorbidities may compete for the attention of the patient and their healthcare team, and therapies to manage comorbidities may adversely affect a person's diabetes. The presence of renal or liver disease reduces the types of antihyperglycemic therapies available for use. As a result, insulin and sulfonylurea-based therapies may have to be used, but with caution. There may be a growing role for sodium-glucose co-transporter 2 (SGLT-2) inhibitors in diabetic renal disease and for glucagon-like peptide (GLP)-1 therapy in renal and liver disease (nonalcoholic steatohepatitis). Cancer treatments pose considerable challenges in glucose therapy, especially the use of cyclical chemotherapy or glucocorticoids, and cyclical antihyperglycemic regimens may be required. Clinical trials of glucose lowering show reductions in microvascular and, to a lesser extent, cardiovascular complications of diabetes, but these benefits take many years to accrue, and evidence specifically in older people is lacking. Guidelines recognize that clinicians managing patients with type 2 diabetes mellitus need to be mindful of comorbidity, particularly the risks of hypoglycemia, and ensure that patient-centered therapeutic management of diabetes is offered. Targets for glucose control need to be carefully considered in the context of comorbidity, life expectancy, quality of life, and patient wishes and expectations. This review discusses the role of chronic kidney disease, chronic liver disease, cancer, severe mental illness, ischemic heart disease, and frailty as comorbidities in the therapeutic management of hyperglycemia in patients with type 2 diabetes mellitus. Topics: Comorbidity; Diabetes Mellitus, Type 2; Drug Therapy, Combination; End Stage Liver Disease; Frailty; Glucagon-Like Peptide 1; Humans; Hyperglycemia; Hypoglycemia; Hypoglycemic Agents; Insulin; Mental Disorders; Myocardial Ischemia; Neoplasms; Quality of Life; Renal Insufficiency, Chronic; Sodium-Glucose Transporter 2 Inhibitors | 2019 |
Function and mechanisms of enteroendocrine cells and gut hormones in metabolism.
Gut hormones have many key roles in the control of metabolism, as they target diverse tissues involved in the control of intestinal function, insulin secretion, nutrient assimilation and food intake. Produced by scattered cells found along the length of the intestinal epithelium, gut hormones generate signals related to the rate of nutrient absorption, the composition of the luminal milieu and the integrity of the epithelial barrier. Gut hormones already form the basis for existing and developing therapeutics for type 2 diabetes mellitus and obesity, exemplified by the licensed glucagon-like peptide 1 (GLP1) mimetics and dipeptidyl peptidase inhibitors that enhance GLP1 receptor activation. Modulating the release of the endogenous stores of GLP1 and other gut hormones is thought to be a promising strategy to mimic bariatric surgery with its multifaceted beneficial effects on food intake, body weight and blood glucose levels. This Review focuses on the molecular mechanisms underlying the modulation of gut hormone release by food ingestion, obesity and the gut microbiota. Depending on the nature of the stimulus, release of gut hormones involves recruitment of a variety of signalling pathways, including G protein-coupled receptors, nutrient transporters and ion channels, which are targets for future therapeutics for diabetes mellitus and obesity. Topics: Animals; Cells, Cultured; Diabetes Mellitus, Type 2; Digestion; Eating; Enteroendocrine Cells; Female; Gastrointestinal Hormones; Gastrointestinal Microbiome; Glucagon-Like Peptide 1; Humans; Male; Obesity; Prognosis; Risk Assessment | 2019 |
Incretin Physiology and Pharmacology in the Intensive Care Unit.
In health, postprandial glycemic excursions are attenuated via stimulation of insulin secretion, suppression of glucagon secretion, and slowing of gastric emptying. The incretin hormones, glucagon-like peptide-1 and glucose-dependent insulinotropic polypeptide, are primary modulators of this response. Drugs have recently been developed that exploit the incretin-axis for the management of type 2 diabetes. There is burgeoning interest in the potential of incretin therapies for the management of acute hyperglycemia in the critically ill. This article outlines basic incretin physiology, highlights relevant pharmacology, and briefly summarizes the literature on incretins for glycemic control in the critically ill. Topics: Adult; Aged; Aged, 80 and over; Blood Glucose; Critical Care; Diabetes Mellitus, Type 2; Female; Gastric Inhibitory Polypeptide; Glucagon-Like Peptide 1; Glycemic Index; Humans; Hypoglycemic Agents; Incretins; Male; Middle Aged; Receptors, Gastrointestinal Hormone | 2019 |
Meta-analyses of the effects of DPP-4 inhibitors, SGLT2 inhibitors and GLP1 receptor analogues on cardiovascular death, myocardial infarction, stroke and hospitalization for heart failure.
To assess the effects DPP-4i; SGLT2-i & GLP1-RA on CV death, MI, stroke and hHF. This is probably the first meta-analysis to assess the effects of these drugs on MI and stroke in totality, including non-fatal & fatal MI and stroke.. Scientific databases were searched for RCTs with pre-specified inclusion criteria and each end-point from the selected 13 studies was reported as an effect size (M H odds ratio) with a 95% confidence interval P value.. The pooled analysis of all the 5 available CVOT with DPP-4i resulted in a neutral effect on MI, stroke, the combined end points of MI & Stroke, CV death and hHF. The pooled analysis of all the 5 available CVOTs with GLP1-RA resulted in a neutral effect on MI. However, there was a statistically significant 12% reduction in CV death (P = 0.01), 13% reduction in stroke (P = 0.02) and 11% reduction the combined end points of MI & Stroke (P = 0.001). The impact of GLP1-RA inhibitors on hHF was neutral. The pooled analysis of all the 3 available CVOTs with SGLT2-i resulted in a neutral effect on MI, stroke, the combined end points of MI & Stroke and CV death. There was however a statistically significant 28% reduction in hHF (P < 0.001).. DPP-4i & SGLT-2i are neutral as far as all aspects of CV outcomes are concerned except for hHF which is significantly reduced by the latter. GLP1-RA as a class reduce risk of ASCVD showing a significant reduction in MI and stroke. Topics: Cardiovascular Diseases; Diabetes Mellitus, Type 2; Dipeptidyl-Peptidase IV Inhibitors; Glucagon-Like Peptide 1; Heart Failure; Hospitalization; Humans; Hypoglycemic Agents; Incidence; Myocardial Infarction; Sodium-Glucose Transporter 2 Inhibitors; Stroke | 2019 |
Anti-diabetic treatment leads to changes in gut microbiome.
Numerous micro-organisms naturally reside in the human body assuming a symbiotic, or, at times, even a dysbiotic relationship with the host. These microbial populations are referred to as the human microbiota. Host microbial populations are an important mediator of gastro-intestinal mucosal permeability, bile acid metabolism, short-chain fatty acids synthesis, fermentation of dietary polysaccharides and FXR/TGR5 signaling. Variations in the composition and function of gut microbiota have been observed in type 2 diabetes mellitus, insulin resistance and obesity, as well as in inflammatory bowel diseases. The microbial imbalance induced by such pathological processes is described as dysbiosis. In this review, we describe the pathophysiological links between type 2 diabetes mellitus and gut microbiota, explore the effect of anti-diabetic drugs on gut microbiota and suggest possible therapeutic targets. Topics: alpha-Glucosidases; Animals; Diabetes Mellitus, Type 2; Dipeptidyl Peptidase 4; Dipeptidyl-Peptidase IV Inhibitors; Dysbiosis; Fermentation; Gastrointestinal Microbiome; Glucagon-Like Peptide 1; Humans; Hypoglycemic Agents; Incretins; Insulin Resistance; Lipid Metabolism; Metformin; Mice; Obesity; Permeability; Polysaccharides; Signal Transduction; Sodium-Glucose Transporter 2 Inhibitors | 2019 |
Changes in Bile Acid Metabolism, Transport, and Signaling as Central Drivers for Metabolic Improvements After Bariatric Surgery.
We review current evidence regarding changes in bile acid (BA) metabolism, transport, and signaling after bariatric surgery and how these might bolster fat mass loss and energy expenditure to promote improvements in type 2 diabetes (T2D) and nonalcoholic fatty liver disease (NAFLD).. The two most common bariatric techniques, Roux-en-Y gastric bypass (RYGB) and vertical sleeve gastrectomy (VSG), increase the size and alter the composition of the circulating BA pool that may then impact energy metabolism through altered activities of BA targets in the many tissues perfused by systemic blood. Recent reports in human patients indicate that gene expression of the major BA target, the farnesoid X receptor (FXR), is increased in the liver but decreased in the small intestine after RYGB. In contrast, intestinal expression of the transmembrane G protein-coupled BA receptor (TGR5) is upregulated after surgery. Despite these apparent conflicting changes in receptor transcription, changes in BAs after both RYGB and VSG are associated with elevated postprandial systemic levels of fibroblast growth factor 19 (from FXR activation) and glucagon-like peptide 1 (from TGR5 activation). These signaling activities are presumed to support fat mass loss and related metabolic benefits of bariatric surgery, and this supposition is in agreement with findings from rodent models of RYGB and VSG. However, inter-species differences in BA physiology limit direct translation and mechanistic understanding of how changes in individual BA species contribute to post-operative improvements of T2D and NAFLD in humans. Thus, details of all these changes and their influences on BAs' biological actions are still under scrutiny. Changes in BA physiology and receptor activities after RYGB and VSG likely support weight loss and promote sustained metabolic improvements. Topics: Bariatric Surgery; Bile Acids and Salts; Diabetes Mellitus, Type 2; Fibroblast Growth Factors; Gastrectomy; Gastric Bypass; Glucagon-Like Peptide 1; Glucose; Homeostasis; Humans; Non-alcoholic Fatty Liver Disease; Obesity, Morbid; Postprandial Period; Receptors, Cytoplasmic and Nuclear; Receptors, G-Protein-Coupled; Signal Transduction; Weight Loss | 2019 |
[Glucagon-like peptide 1 receptor agonists for the treatment of Type 2 diabetes].
Supraphysiological levels of the incretin hormone glucagon-like peptide 1 (GLP-1) have demonstrated a marked glucose-lowering effect in patients with Type 2 diabetes. Six GLP-1 receptor agonists are currently available for the treatment of Type 2 diabetes and have all proven to render significant reductions in both glycated haemoglobin level and body weight. However, of the clinical available compounds only liraglutide, dulaglutide and semaglutide have demonstrated reductions in the risk of cardiovascular disease. This review aims at providing an overview of the efficacy and safety of the GLP-1 receptor agonist class. Topics: Diabetes Mellitus, Type 2; Glucagon-Like Peptide 1; Glucagon-Like Peptide-1 Receptor; Glycated Hemoglobin; Humans; Hypoglycemic Agents; Liraglutide | 2019 |
GLP-1: Molecular mechanisms and outcomes of a complex signaling system.
Meal ingestion provokes the release of hormones and transmitters, which in turn regulate energy homeostasis and feeding behavior. One such hormone, glucagon-like peptide-1 (GLP-1), has received significant attention in the treatment of obesity and diabetes due to its potent incretin effect. In addition to the peripheral actions of GLP-1, this hormone is able to alter behavior through the modulation of multiple neural circuits. Recent work that focused on elucidating the mechanisms and outcomes of GLP-1 neuromodulation led to the discovery of an impressive array of GLP-1 actions. Here, we summarize the many levels at which the GLP-1 signal adapts to different systems, with the goal being to provide a background against which to guide future research. Topics: Animals; Brain; Diabetes Mellitus, Type 2; Feeding Behavior; Glucagon-Like Peptide 1; Humans; Obesity; Reward; Signal Transduction | 2019 |
Glucagon-Like Peptide-1 Receptor Agonists and Strategies To Improve Their Efficiency.
Type 2 diabetes mellitus (T2DM) is increasing in global prevalence and is associated with serious health problems (e.g., cardiovascular disease). Various treatment options are available for T2DM, including the incretin hormone glucagon-like peptide-1 (GLP-1). GLP-1 is a therapeutic peptide secreted from the intestines following food intake, which stimulates the secretion of insulin from the pancreas. The native GLP-1 has a very short plasma half-life, owning to renal clearance and degradation by the enzyme dipeptidyl peptidase-4. To overcome this issue, various GLP-1 agonists with increased resistance to proteolytic degradation and reduced renal clearance have been developed, with several currently marketed. Strategies, such as controlled release delivery systems, methods to reduce renal clearance (e.g., PEGylation and conjugation to antibodies), and methods to improve proteolytic stability (e.g., stapling, cyclization, and glycosylation) provide means to further improve the ability of GLP-1 analogs. These will be discussed in this literature review. Topics: Animals; Diabetes Mellitus, Type 2; Glucagon-Like Peptide 1; Glucagon-Like Peptide-1 Receptor; Humans; Hypoglycemic Agents; Peptides | 2019 |
Mechanism of Glucagon-Like Peptide 1 Improvements in Type 2 Diabetes Mellitus and Obesity.
The purpose of this review is to emphasize the pivotal role of glucagon-like peptide 1 (GLP-1) in tackling the parallel epidemics of obesity and type 2 diabetes (T2DM).. GLP-1-based therapies and in particular GLP-1 receptor agonists (GLP-1 RA) have proven to be effective in lowering blood glucose and decreasing weight. GLP-1 RA not only mitigate these significant medical burdens but also result in weight loss and weight loss independent factors that decrease cardiovascular disease (CVD) and microvascular complications of T2DM, such as diabetic nephropathy. GLP-1-based therapies are critical for a patient-centered approach in choosing appropriate pharmacotherapy for T2DM and obesity while also taking into consideration comorbidities, such as cardiovascular and chronic kidney diseases. Topics: Animals; Blood Glucose; Cardiovascular Diseases; Cardiovascular System; Diabetes Mellitus, Type 2; Glucagon-Like Peptide 1; Glucagon-Like Peptide-1 Receptor; Humans; Obesity; Renal Insufficiency, Chronic; Weight Loss | 2019 |
[GLP-1 analogues in 2019 : for whom and how ?]
GLP-1 analogues are a well-established treatment for type 2 diabetes. They act by improving glycemic control through several mechanisms. They also have the advantage of inducing weight loss without the risk of associated hypoglycemia. This class of molecules has also shown a benefit in cardiovascular events such as cardiovascular mortality, stroke and myocardial infarction, and albuminuria. These favorable effects place them, like SGLT-2 inhibitors, as a second option in the case of unsatisfactory glycemic control after metformin and dietary and lifestyle measures. This article provides an overview of the current knowledge of GLP-1 analogue therapy in patients with type 2 diabetes.. Les analogues du GLP-1 constituent un traitement bien établi du diabète de type 2 en permettant une amélioration du contrôle glycémique au travers de plusieurs mécanismes. Ils possèdent également comme avantage l’induction d’une perte de poids sans risque d’hypoglycémie associée. Cette classe de molécules a aussi montré un bénéfice sur les événements cardiovasculaires tels que la mortalité cardiovasculaire, la survenue d’AVC et d’infarctus du myocarde et l’albuminurie. Ces effets favorables les placent, comme les inhibiteurs du SGLT-2, en deuxième option en cas de contrôle glycémique non satisfaisant après la metformine et les mesures hygiéno-diététiques. Cet article fait un survol des connaissances actuelles du traitement par analogues du GLP-1 chez les patients avec un diabète de type 2. Topics: Blood Glucose; Diabetes Mellitus, Type 2; Glucagon-Like Peptide 1; Humans; Hypoglycemic Agents; Metformin | 2019 |
Effects of novel antidiabetes agents on apoptotic processes in diabetes and malignancy: Implications for lowering tissue damage.
Apoptosis is a complicated process that involves activation of a series of intracellular signaling. Tissue injuries from diabetes mellitus mostly occur as a consequence of higher rate of apoptosis process due to activation of a series of molecular mechanisms. Several classes of anti-hyperglycaemic agents have been developed which could potentially modulate the apoptotic process resulting in fewer tissue damages. Novel types of anti-hyperglycaemic medications such as sodium glucose cotransporters-2 inhibitors, glucagon like peptide-1 receptor agonists and dipeptidyl peptidase 4 inhibitors have shown to provide potent anti-hyperglycaemic effects, but their influences on diabetes-induced apoptotic injuries is largely unknown. Therefore, in the current study, we reviewed the published data about the possible effects of these anti-hyperglycaemic agents on apoptosis in diabetic milieu as well as in cancer cells. Topics: Apoptosis; Blood Glucose; Deafness; Diabetes Mellitus, Type 2; Dipeptidyl-Peptidase IV Inhibitors; Glucagon-Like Peptide 1; Glucagon-Like Peptide-1 Receptor; Glucagon-Like Peptides; Humans; Hypoglycemic Agents; Mitochondrial Diseases; Neoplasms; Sodium-Glucose Transporter 2 Inhibitors | 2019 |
Dipeptidyl peptidase IV inhibitors as a potential target for diabetes: patent review (2015-2018).
Dipeptidyl peptidase 4 (DPP-4) belongs to the family of serine proteases and is involved in the degradation of GLP-1 and GIP hormones, which enhance the production and release of insulin. Targeting DPP-4 inhibitors is increasingly being considered as promising paradigms to treat type 2 diabetes mellitus and therefore DPP-4 inhibitors are being considered as promising antidiabetic drugs.. This review provides an overview of published patents describing natural and synthetic DPP-4 inhibitors from January 2015 to December 2018.. A fair number of new synthetic and natural DPP-4 inhibitors have been reported in the last four years which describe the progress in the development of various heterocyclic scaffolds or heterocyclic hybrid compounds. As a result of this, many marketed DPP-4 inhibitors that have been approved by the appropriate governing bodies during the past decade, have been introduced as inhibitors. Molecular hybridization is an emerging idea in medicinal chemistry and therefore hybrid compounds of DPP-4 inhibitors with other DPP-4 inhibitors or with antidiabetic drugs should be formulated for a comprehensive evaluation. More detailed pharmacovigilance of DPP-4 inhibitors is required because this will address the pancreas-related adverse events as well as their impact on cardiovascular outcomes via long-term studies. Topics: Animals; Diabetes Mellitus, Type 2; Dipeptidyl Peptidase 4; Dipeptidyl-Peptidase IV Inhibitors; Drug Design; Glucagon-Like Peptide 1; Humans; Hypoglycemic Agents; Insulin; Patents as Topic | 2019 |
Initial injectable therapy in type 2 diabetes: Key considerations when choosing between glucagon-like peptide 1 receptor agonists and insulin.
Managing type 2 diabetes is complex and necessitates careful consideration of patient factors such as engagement in self-care, comorbidities and costs. Since type 2 diabetes is a progressive disease, many patients will require injectable agents, usually insulin. Recent ADA-EASD guidelines recommend glucagon-like peptide 1 receptor agonists (GLP-1 RAs) as first injectable therapy in most cases. The basis for this recommendation is the similar glycemic efficacy of GLP-1 RAs and insulin, but with GLP-1 RAs promoting weight loss instead of weight gain, at lower hypoglycemia risk, and with cardiovascular benefits in patients with pre-existing cardiovascular disease. GLP-1 RAs also reduce burden of glucose self-monitoring. However, tolerability and costs are important considerations, and notably, rates of drug discontinuation are often higher for GLP-1 RAs than basal insulin. To minimize risk of gastrointestinal symptoms patients should be started on lowest doses of GLP-1 RAs and up-titrated slowly. Overall healthcare costs may be lower with GLP-1 RAs compared to insulin. Though patient-level costs may still be prohibitive, GLP-1 RAs can replace 50-80 units of insulin daily and reduce costs associated with glucose self-monitoring. Decisions regarding initiating injectable therapy should be individualized. This review provides a framework to guide decision-making in the real-world setting. Topics: Animals; Diabetes Mellitus, Type 2; Glucagon-Like Peptide 1; Glucagon-Like Peptide-1 Receptor; Humans; Hypoglycemic Agents; Injections; Insulin | 2019 |
The role of glucagon-like peptide-1 in reproduction: from physiology to therapeutic perspective.
Glucagon-like peptide-1 (GLP-1) receptor agonists (GLP-1 RAs) have become firmly established in the treatment of type 2 diabetes and obesity, disorders frequently associated with diminished reproductive health. Understanding of the role of GLP-1 and GLP-1 RAs in reproduction is currently limited and largely unaddressed in clinical studies.. The purpose of this narrative review is to provide a comprehensive overview of the role of GLP-1 in reproduction and to address a therapeutic perspective that can be derived from these findings.. We performed a series of PubMed database systemic searches, last updated on 1 February 2019, supplemented by the authors' knowledge and research experience in the field. A search algorithm was developed incorporating the terms glucagon-like peptide-1, GLP-1, glucagon-like peptide-1 receptor, GLP-1R, or incretins, and this was combined with terms related to reproductive health. The PICO (Population, Intervention, Comparison, Outcome) framework was used to identify interventional studies including GLP-1 RAs and dipeptidyl peptidase-4 (DPP-4) inhibitors, which prevent the degradation of endogenously released GLP-1. We identified 983 potentially relevant references. At the end of the screening process, we included 6 observational (3 preclinical and 3 human) studies, 24 interventional (9 preclinical and 15 human) studies, 4 case reports, and 1 systematic and 2 narrative reviews.. The anatomical distribution of GLP-1 receptor throughout the reproductive system and observed effects of GLP-1 in preclinical models and in a few clinical studies indicate that GLP-1 might be one of the important modulating signals connecting the reproductive and metabolic system. The outcomes show that there is mostly stimulating role of GLP-1 and its mimetics in mammalian reproduction that goes beyond mere weight reduction. In addition, GLP-1 seems to have anti-inflammatory and anti-fibrotic effects in the gonads and the endometrium affected by obesity, diabetes, and polycystic ovary syndrome (PCOS). It also seems that GLP-1 RAs and DPP-4 inhibitors can reverse polycystic ovary morphology in preclinical models and decrease serum concentrations of androgens and their bioavailability in women with PCOS. Preliminary data from interventional clinical studies suggest improved menstrual regularity as well as increased fertility rates in overweight and/or obese women with PCOS treated with GLP-1 RAs in the preconception period.. GLP-1 RAs and DPP-4 inhibitors show promise in the treatment of diabetes and obesity-related subfertility. Larger interventional studies are needed to establish the role of preconception intervention with GLP-1 based therapies, assessing fertility outcomes in obesity, PCOS, and diabetes-related fertility problems. The potential impact of the dose- and exposure time-response of different GLP-1 RAs need further exploration. Future research should also investigate sex-specific variability of GLP-1 on reproductive outcomes, in particular on the gonads where the observations in males are most conflicting. Topics: Animals; Diabetes Mellitus, Type 2; Female; Glucagon-Like Peptide 1; Glucagon-Like Peptide-1 Receptor; Gonadal Disorders; Humans; Hypoglycemic Agents; Incretins; Infertility; Male; Obesity; Polycystic Ovary Syndrome; Reproduction; Weight Loss | 2019 |
[Incretin-based co- and tri-agonists : Innovative polypharmacology for the treatment of obesity and diabetes].
The worldwide rise in overweight and obesity is paralleled by an increasing prevalence of type-2 diabetes. Apart from bariatric surgery, treatment options to decrease body weight are often underwhelming. Innovative pharmacological options are required to cope with the global "diabesity" pandemic.. Particular novel pharmacological approaches are discussed, with a special focus on polyagonist-based pharmacotherapies.. Articles on co- and tri-agonists for the treatment of obesity and diabetes are presented and discussed.. Unimolecular peptides have been developed for the treatment of obesity and type-2 diabetes. These peptides activate the receptors of multiple hormones and bundle their positive effects in one single molecule. In preclinical studies, polyagonists targeting the receptors for glucagon-like peptide-1 (GLP-1), glucagon, or glucose-dependent insulinotropic peptide (GIP) were promising to reduce body weight and blood glucose. GLP-1-mediated delivery of the nuclear hormones estrogen or dexamethasone also yielded beneficial effects in preclinical studies of obesity.. Polyagonists represent an innovative strategy for the development of novel pharmacotherapies to treat obesity and diabetes. Topics: Diabetes Mellitus, Type 2; Gastric Inhibitory Polypeptide; Glucagon-Like Peptide 1; Humans; Incretins; Insulin; Obesity; Polypharmacology | 2019 |
The effect of glucagon-like peptide-1 and glucagon-like peptide-2 on microcirculation: A systematic review.
GLP-1 and GLP-2 are gut-derived hormones used in the treatment of diabetes type-2 and short bowel syndrome, respectively. GLP-1 attenuates insulin resistance and GLP-2 reduces enterocyte apoptosis and enhances crypt cell proliferation in the small intestine. In addition, both hormones have vasoactive effects and may be useful in situations with impaired microcirculation. The aim of this systematic review was to provide an overview of the potential effects of GLP-1 and GLP-2 on microcirculation. A systematic search was performed independently by two authors in the following databases: PubMed, EMBASE, Cochrane library, Scopus, and Web of Science. Of 1111 screened papers, 20 studies were included in this review: 16 studies in animals, three in humans, and one in humans and rats. The studies were few and heterogeneous and had a high risk of bias. However, it seems that GLP-1 regulates the pancreatic, skeletal, and cardiac muscle flow, indicating a role in the glucose homeostasis, while GLP-2 acts primarily in the regulation of the microcirculation of the mid-intestine. These findings may be useful in gastrointestinal surgery and in situations with impaired microcirculation of the gut. Topics: Animals; Diabetes Mellitus, Type 2; Glucagon-Like Peptide 1; Glucagon-Like Peptide 2; Humans; Insulin Resistance; Microcirculation; Rats | 2019 |
Incretins and Lipid Metabolism.
Recent findings indicate that incretin hormones and incretin-based therapies may affect the metabolism of lipoproteins, although the corresponding mechanisms are not clearly defined.. To summarize the available data on the mechanisms linking incretins with the characteristics of serum lipoproteins and discuss the clinical implications of these relationships.. PubMed was searched using the terms "incretins", "GLP-1", "GIP" and "lipids", "dyslipidemia", "triglycerides", "apolipoprotein B48". All articles published in the English language until June 2016 were assessed and the relevant information is presented here.. GLP-1, and therapies that increase its activity, exert a beneficial effect on lipoprotein metabolism that is translated in a reduction in the fasting and postprandial concentration of triglycerides and a small improvement in the concentration and function of HDLs. In addition, a shift towards larger, less atherogenic particles usually follows the administration of GLP-1 receptor agonists. The mechanisms that underlie these changes involve a direct effect of GLP- 1 on the hepatic and intestinal production of triglyceride-rich lipoproteins, the GLP-1 induced increase in the production and function of insulin, the activation of specific areas of central nervous system as well as the increase in the peripheral utilization of triglycerides for energy production. On the other hand, GLP-2 increases the absorption of dietary fat and the production of triglyceride-rich lipoproteins while the role of GIP on lipid metabolism remains indeterminate.. GLP-1 and incretin-based therapies favorably affect lipid metabolism. These effects may contribute to the beneficial effects of incretin-based therapies on atherosclerosis and fatty liver disease. Topics: Diabetes Mellitus, Type 2; Dipeptidyl-Peptidase IV Inhibitors; Glucagon-Like Peptide 1; Glucagon-Like Peptide-1 Receptor; Humans; Incretins; Lipoproteins, HDL; Lipoproteins, LDL; Liver Diseases; Triglycerides | 2018 |
Medication use for the treatment of diabetes in obese individuals.
Obesity is a major cause of type 2 diabetes and may complicate type 1 diabetes. Weight loss for obese individuals with diabetes has many health benefits, often leads to improvement in glucose control and sometimes, in type 2 diabetes, near normalisation of abnormal glucose metabolism. Weight loss is difficult to maintain and attempts to lose weight may be undermined by some diabetes treatments such as sulfonylureas, thiazolidinediones and insulin. Whilst lifestyle support should be the primary approach to aid individuals who wish to lose weight, pharmacological approaches can also be considered. These include choosing glucose-lowering drugs or drug combinations that are weight neutral or result in weight loss or prescribing drugs that are specifically approved as anti-obesity medication. Given that some of the newer glucose-lowering medications that cause weight loss, such as glucagon-like peptide-1 receptor agonists (GLP-1 RAs) and sodium-glucose cotransporter 2 inhibitors (SGLT2i), are also being used or considered for use as anti-obesity drugs, it seems that the distinction between glucose-lowering medication and weight loss medication is becoming blurred. This review discusses the main pharmacological approaches that can be used to support weight loss in individuals with diabetes. Topics: Animals; Benzazepines; Bupropion; Diabetes Mellitus, Type 2; Glucagon-Like Peptide 1; Humans; Lactones; Naltrexone; Obesity; Orlistat | 2018 |
Do we know the true mechanism of action of the DPP-4 inhibitors?
The prevalence of type 2 diabetes is increasing, which is alarming because of its serious complications. Anti-diabetic treatment aims to control glucose homeostasis as tightly as possible in order to reduce these complications. Dipeptidyl peptidase-4 (DPP-4) inhibitors are a recent addition to the anti-diabetic treatment modalities, and have become widely accepted because of their good efficacy, their benign side-effect profile and their low hypoglycaemia risk. The actions of DPP-4 inhibitors are not direct, but rather are mediated indirectly through preservation of the substrates they protect from degradation. The two incretin hormones, glucagon-like peptide-1 and glucose-dependent insulinotropic polypeptide, are known substrates, but other incretin-independent mechanisms may also be involved. It seems likely therefore that the mechanisms of action of DPP-4 inhibitors are more complex than originally thought, and may involve several substrates and encompass local paracrine, systemic endocrine and neural pathways, which are discussed here. Topics: Animals; Diabetes Mellitus, Type 2; Dipeptidyl-Peptidase IV Inhibitors; Gastric Inhibitory Polypeptide; Gastrointestinal Motility; Glucagon-Like Peptide 1; Humans; Incretins; Insulin; Insulin Secretion; Models, Biological; Pancreas; Proteolysis; Signal Transduction; Synaptic Transmission | 2018 |
Effects of gastric inhibitory polypeptide, glucagon-like peptide-1 and glucagon-like peptide-1 receptor agonists on Bone Cell Metabolism.
The relationship between gut and skeleton is increasingly recognized as part of the integrated physiology of the whole organism. The incretin hormones gastric inhibitory polypeptide (GIP) and glucagon-like peptide-1 (GLP-1) are secreted from the intestine in response to nutrient intake and exhibit several physiological functions including regulation of islet hormone secretion and glucose levels. A number of GLP-1 receptor agonists (GLP-1RAs) are currently used in treatment of type 2 diabetes and obesity. However, GIP and GLP-1 cognate receptors are widely expressed suggesting that incretin hormones mediate effects beyond control of glucose homeostasis, and reports on associations between incretin hormones and bone metabolism have emerged. The aim of this MiniReview was to provide an overview of current knowledge regarding the in vivo and in vitro effects of GIP and GLP-1 on bone metabolism. We identified a total of 30 pre-clinical and clinical investigations of the effects of GIP, GLP-1 and GLP-1RAs on bone turnover markers, bone mineral density (BMD), bone microarchitecture and fracture risk. Studies conducted in cell cultures and rodents demonstrated that GIP and GLP-1 play a role in regulating skeletal homeostasis, with pre-clinical data suggesting that GIP inhibits bone resorption whereas GLP-1 may promote bone formation and enhance bone material properties. These effects are not corroborated by clinical studies. While there is evidence of effects of GIP and GLP-1 on bone metabolism in pre-clinical investigations, clinical trials are needed to clarify whether similar effects are present and clinically relevant in humans. Topics: Animals; Bone and Bones; Bone Density; Bone Resorption; Diabetes Mellitus, Type 2; Disease Models, Animal; Fractures, Bone; Gastric Inhibitory Polypeptide; Glucagon-Like Peptide 1; Glucagon-Like Peptide-1 Receptor; Humans; Incretins; Insulin; Obesity; Osteoblasts; Osteocalcin; Osteoclasts | 2018 |
The potential benefits of glucagon-like peptide-1 receptor agonists for diabetic retinopathy.
For a long time, diabetic retinopathy (DR) has been one of the most severe complications of diabetes. The early treatment of DR is not clearly recognized. The additional benefit of hypoglycemic agents for DR has become a new research field. Glucagon-like peptide-1 receptor (GLP-1R) has been shown to be widely expressed in tissues including retina. Glucagon-like peptide-1 receptor agonists (GLP-1RA) have been generally used in the treatment of diabetic patients. Studies shows that GLP-1RA could inhibit nerve damage by decrease apoptosis of nerve cells and activation of glial cells. In addition, GLP-1RA plays a protective role for tight junction (TJ) and cells of blood retinal barrier (BRB). It also protects retina from BRB damage. In this review, we discuss the potential protective mechanisms of GLP-1RA for DR beyond the hypoglycemic effects. Topics: Apoptosis; Diabetes Mellitus, Type 2; Diabetic Retinopathy; Glucagon-Like Peptide 1; Glucagon-Like Peptide-1 Receptor; Humans; Nerve Degeneration; Retina | 2018 |
RD Lawrence Lecture 2017 Incretins: the intelligent hormones in diabetes.
The incretin hormones glucose-dependent insulinotropic polypeptide (GIP) and glucagon-like peptide-1 (GLP-1) have attracted considerable scientific and clinical interest due largely to their insulin-releasing and glucose-lowering properties. Indeed, GLP-1-based therapies are now key treatment options for many people with diabetes worldwide. In contrast, GIP-based agents have yet to reach the clinic based primarily on the impaired insulinotropic action of GIP observed in people with diabetes. Nevertheless, GIP is a key physiological regulator of insulin secretion and stable forms of GIP show much promise in rodent models to alleviate diabetes-obesity. Recent studies suggest that GIP may have an important role to play in a combination therapeutic approach or bioengineered with other gut peptides. Moreover, recent experimental studies indicate that incretins also exert pleiotropic effects in regions of the brain associated with learning and memory, thereby supporting preclinical data demonstrating that incretin-based drugs improve cognitive function. This review article, based on the RD Lawrence Lecture presented at Diabetes UK Annual Professional Conference (2017), provides a brief overview of incretins with a major focus on GIP, the development of designer GIP analogues, and how these molecules can improve cognition. Thus, incretins can be considered as 'the intelligent hormones' and may hold the key to successfully treating the alarming rise in neurodegenerative disorders. Topics: Alzheimer Disease; Animals; Cognition; Diabetes Mellitus, Type 2; Disease Models, Animal; Gastric Inhibitory Polypeptide; Glucagon-Like Peptide 1; Humans; Hypoglycemic Agents; Incretins; Learning; Memory; Nootropic Agents | 2018 |
Altered glucose metabolism after bariatric surgery: What's GLP-1 got to do with it?
Bariatric surgery is an effective treatment for obesity. The two widely performed weight-loss procedures, Roux-en-Y gastric bypass (GB) and sleeve gastrectomy (SG), alter postprandial glucose pattern and enhance gut hormone secretion immediately after surgery before significant weight loss. This weight-loss independent glycemic effects of GB has been attributed to an accelerated nutrient transit from stomach pouch to the gut and enhanced secretion of insulinotropic gut factors; in particular, glucagon-like peptide-1 (GLP-1). Meal-induced GLP-1 secretion is as much as tenfold higher in patients after GB compared to non-surgical individuals and inhibition of GLP-1 action during meals reduces postprandial hyperinsulinemia after GB two to three times more than that in persons without surgery. Moreover, in a subgroup of patients with the late complication of postprandial hyperinsulinemic hypoglycemia after GB, GLP1R blockade reverses hypoglycemia by reducing meal stimulated insulin secretion. The role of enteroinsular axis activity after SG, an increasingly popular alternative to GB, is less understood but, similar to GB, SG accelerates nutrient delivery to the intestine, improves glucose tolerance, and increases postprandial GLP-1 secretion. This review will focus on the current evidence for and against the role of GLP-1 on glycemic effects of GB and will also highlight differences between GB and SG. Topics: Bariatric Surgery; Blood Glucose; Diabetes Mellitus, Type 2; Gastrectomy; Gastric Bypass; Glucagon-Like Peptide 1; Humans; Insulin; Obesity; Weight Loss | 2018 |
Optimization of peptide-based polyagonists for treatment of diabetes and obesity.
Topics: Amino Acid Sequence; Animals; Diabetes Mellitus, Type 2; Drug Discovery; Gastric Inhibitory Polypeptide; Glucagon; Glucagon-Like Peptide 1; Humans; Obesity; Peptides | 2018 |
Advances in micro- and nanotechnologies for the GLP-1-based therapy and imaging of pancreatic beta-cells.
Therapies to prevent diabetes in particular the progressive loss of β-cell mass and function and/or to improve the dysregulated metabolism associated with diabetes are highly sought. The incretin-based therapy comprising GLP-1R agonists and DPP-4 inhibitors have represented a major focus of pharmaceutical R&D over the last decade. The incretin hormone GLP-1 has powerful antihyperglycemic effect through direct stimulation of insulin biosynthesis and secretion within the β-cells; it normalizes β-cell sensitivity to glucose, has an antiapoptotic role, stimulates β-cell proliferation and differentiation, and inhibits glucagon secretion. However, native GLP-1 therapy is inappropriate due to the rapid post-secretory inactivation by DPP-4. Therefore, incretin mimetics developed on the backbone of the GLP-1 or exendin-4 molecule have been developed to behave as GLP-1R agonists but to display improved stability and clinical efficacy. New formulations of incretins and their analogs based on micro- and nanomaterials (i.e., PEG, PLGA, chitosan, liposomes and silica) and innovative encapsulation strategies have emerged to achieve a better stability of the incretin, to improve its pharmacokinetic profile, to lower the administration frequency or to allow another administration route and to display fewer adverse effects. An important advantage of these formulations is that they can also be used at the targeted non-invasive imaging of the beta-cell mass. This review therefore focuses on the current state of these efforts as the next step in the therapeutic evolution of this class of antidiabetic drugs. Topics: Animals; Diabetes Mellitus, Type 2; Dipeptidyl-Peptidase IV Inhibitors; Glucagon-Like Peptide 1; Glucagon-Like Peptide-1 Receptor; Humans; Hypoglycemic Agents; Incretins; Insulin-Secreting Cells; Microtechnology; Nanotechnology; Pancreas | 2018 |
Network meta-analysis of cardiovascular outcomes in randomized controlled trials of new antidiabetic drugs.
Randomized controlled trials (RCTs) directly comparing cardiovascular outcomes of new antidiabetic drugs are lacking. We used network meta-analysis to compare new antidiabetic drug classes with respect to major adverse cardiovascular events (MACE) and mortality.. We searched MEDLINE, EMBASE, the Cochrane database, and ClinicalTrials.gov up to 30 December 2016 for RCTs involving SGLT-2 inhibitors, glucagon-like peptide-1 receptor agonists (GLP-1 RAs) and dipeptidyl peptidase-4 (DPP-4) inhibitors in diabetic patients that reported MACE and deaths. Outcomes were compared with frequentist and Bayesian methods using R statistics.. Seven RCTs with altogether 62,268 patients were included in the network meta-analysis. The SGLT-2 inhibitor and GLP-1 RAs reduced MACE (OR 0.85, 95%CI 0.73-0.99 and 0.89, 0.82-0.97, respectively) and all-cause mortality (0.67, 0.55-0.81 and 0.89, 0.80-0.99, respectively) compared to placebo. Furthermore, the SGLT-2 inhibitor reduced all-cause mortality compared to GLP-1 RAs (0.76, 0.61-0.94). In contrast, DPP-4 inhibitors did not reduce MACE or mortality compared to placebo and were associated with higher all-cause mortality compared to the SGLT-2 inhibitor (1.53, 1.24-1.89) and GLP-1 RAs (1.16, 1.01-1.33).. All-cause mortality and MACE were reduced by the SGLT-2 inhibitor and GLP-1 RAs, but not DPP-4 inhibitors. The SGLT-2 inhibitor had the most beneficial impact on all-cause mortality. DPP-4 inhibitors showed no cardiovascular benefit and were inferior to the other two drug classes in preventing deaths. Topics: Diabetes Mellitus, Type 2; Dipeptidyl-Peptidase IV Inhibitors; Glucagon-Like Peptide 1; Humans; Hypoglycemic Agents; Network Meta-Analysis; Randomized Controlled Trials as Topic; Sodium-Glucose Transporter 2; Sodium-Glucose Transporter 2 Inhibitors; Treatment Outcome | 2018 |
Therapeutic potential of spinal GLP-1 receptor signaling.
GLP-1 signaling pathway has been well studied for its role in regulating glucose homeostasis, as well as its beneficial effects in energy and nutrient metabolism. A number of drugs based on GLP-1 have been used to treat type 2 diabetes mellitus. GLP-1R is expressed in multiple organs and numerous experimental studies have demonstrated that GLP-1 signaling pathway exhibits pro-survival functions in various disorders. In the central nervous system, stimulation of GLP-1R produces neuroprotective effects in specific neurodegenerative disorders, such as Alzheimer's disease and Parkinson's disease. The preproglucagon neurons located in the brainstem can also produce GLP-1. GLP-1 analogs have a long-acting effect and are able to pass the blood-brain barrier, which probably extends the therapeutic efficacy of GLP-1R activation. Neurodegenerative or traumatic conditions can damage the spinal cord and result in motor and sensory dysfunction. Evidence supports that GLP-1R activation in the spinal cord possesses beneficial effects and significant therapeutic potential. Herein, we review studies that have focused on GLP-1 and the spinal cord, and summarize the expression of GLP-1R and the innervation of PPG neurons in the spinal cord, as well as the potential therapeutic benefits of GLP-1R activation. Topics: Alzheimer Disease; Animals; Diabetes Mellitus, Type 2; Glucagon-Like Peptide 1; Glucagon-Like Peptide-1 Receptor; Humans; Neuroprotective Agents; Parkinson Disease; Signal Transduction; Spinal Cord; Spinal Cord Injuries | 2018 |
Incretin hormones: Their role in health and disease.
Incretin hormones are gut peptides that are secreted after nutrient intake and stimulate insulin secretion together with hyperglycaemia. GIP (glucose-dependent insulinotropic polypeptide) und GLP-1 (glucagon-like peptide-1) are the known incretin hormones from the upper (GIP, K cells) and lower (GLP-1, L cells) gut. Together, they are responsible for the incretin effect: a two- to three-fold higher insulin secretory response to oral as compared to intravenous glucose administration. In subjects with type 2 diabetes, this incretin effect is diminished or no longer present. This is the consequence of a substantially reduced effectiveness of GIP on the diabetic endocrine pancreas, and of the negligible physiological role of GLP-1 in mediating the incretin effect even in healthy subjects. However, the insulinotropic and glucagonostatic effects of GLP-1 are preserved in subjects with type 2 diabetes to the degree that pharmacological stimulation of GLP-1 receptors significantly reduces plasma glucose and improves glycaemic control. Thus, it has become a parent compound of incretin-based glucose-lowering medications (GLP-1 receptor agonists and inhibitors of dipeptidyl peptidase-4 or DPP-4). GLP-1, in addition, has multiple effects on various organ systems. Most relevant are a reduction in appetite and food intake, leading to weight loss in the long term. Since GLP-1 secretion from the gut seems to be impaired in obese subjects, this may even indicate a role in the pathophysiology of obesity. Along these lines, an increased secretion of GLP-1 induced by delivering nutrients to lower parts of the small intestines (rich in L cells) may be one factor (among others like peptide YY) explaining weight loss and improvements in glycaemic control after bariatric surgery (e.g., Roux-en-Y gastric bypass). GIP and GLP-1, originally characterized as incretin hormones, have additional effects in adipose cells, bone, and the cardiovascular system. Especially, the latter have received attention based on recent findings that GLP-1 receptor agonists such as liraglutide reduce cardiovascular events and prolong life in high-risk patients with type 2 diabetes. Thus, incretin hormones have an important role physiologically, namely they are involved in the pathophysiology of obesity and type 2 diabetes, and they have therapeutic potential that can be traced to well-characterized physiological effects. Topics: Diabetes Mellitus, Type 2; Eating; Gastric Inhibitory Polypeptide; Glucagon-Like Peptide 1; Glucose; Health; Humans; Incretins; Insulin Secretion; Obesity; Weight Loss | 2018 |
Possible mechanisms of direct cardiovascular impact of GLP-1 agonists and DPP4 inhibitors.
Diabetes mellitus is a leading cause of cardiovascular morbidity and mortality worldwide. Traditional antidiabetic therapies targeting hyperglycemia reduce diabetic microvascular complications but have minor effects on macrovascular complications, including cardiovascular disease. Instead, cardiovascular complications are improved by antidiabetic medications (metformin) and other therapies (statins, antihypertensive medications) ameliorating insulin resistance and other associated metabolic abnormalities. Novel classes of antidiabetic drugs have proven efficacious in improving glycemia, while at the same time exert beneficial effects on pathophysiologic mechanisms of diabetes-related cardiovascular disease. In the present review, we will present current evidence of the cardiovascular effects of two new classes of antidiabetic medications, glucagon-like peptide 1 (GLP-1) agonists and dipeptidyl peptidase-4 (DPP4) inhibitors, focusing from mechanistic preclinical and clinical investigation to late-phase clinical testing. Topics: Cardiovascular Diseases; Diabetes Mellitus, Type 2; Dipeptidyl-Peptidase IV Inhibitors; Global Health; Glucagon-Like Peptide 1; Humans; Hypoglycemic Agents; Morbidity | 2018 |
Incretin-based therapy for the treatment of bone fragility in diabetes mellitus.
Bone fractures are common comorbidities of type 2 diabetes mellitus (T2DM). Bone fracture incidence seems to develop due to increased risk of falls, poor bone quality and/or anti-diabetic medications. Previously, a relation between gut hormones and bone has been suspected. Most recent evidences suggest indeed that two gut hormones, namely glucose-dependent insulinotropic polypeptide (GIP) and glucagon-like peptide-1 (GLP-1), may control bone remodeling and quality. The GIP receptor is expressed in bone cells and knockout of either GIP or its receptor induces severe bone quality alterations. Similar alterations are also encountered in GLP-1 receptor knock-out animals associated with abnormal osteoclast resorption. Some GLP-1 receptor agonist (GLP-1RA) have been approved for the treatment of type 2 diabetes mellitus and although clinical trials may not have been designed to investigate bone fracture, first results suggest that GLP-1RA may not exacerbate abnormal bone quality observed in T2DM. The recent design of double and triple gut hormone agonists may also represent a suitable alternative for restoring compromised bone quality observed in T2DM. However, although most of these new molecules demonstrated weight loss action, little is known on their bone safety. The present review summarizes the most recent findings on peptide-based incretin therapy and bone physiology. Topics: Animals; Bone Remodeling; Comorbidity; Diabetes Mellitus, Type 2; Disease Models, Animal; Fractures, Bone; Gastric Inhibitory Polypeptide; Gastrointestinal Hormones; Glucagon-Like Peptide 1; Glucagon-Like Peptide-1 Receptor; Humans; Incretins; Mice; Mice, Knockout | 2018 |
Intestinal peptide changes after bariatric and minimally invasive surgery: Relation to diabetes remission.
Bariatric surgery is very effective in achieving and maintaining weight loss but it is also associated with improvement of obesity metabolic complications, primarily type 2 diabetes (T2D). Remission of T2D or at least a net improvement of glycemic control persists for at least 5 years. The bypass of duodenum and of the first portion of the jejunum up to the Treitz ligament as in Roux-en-Y Gastric Bypass (RYGB), or the bypass of the duodenum, the entire jejunum and the first tract of the ileum, such as in Bilio-Pancreatic Diversion (BPD), achieve different results on insulin sensitivity. Insulin resistance is the major driver of T2D manifesting long before insulin secretion failure. In fact, T2D development can be prevented by treatment with insulin sensitizing agents. Interestingly, RYGB improves hepatic insulin sensitivity while BPD ameliorates whole-body insulin sensitivity. Two major theories have been advocated to explain the early remission of T2D following RYGB or BPD before a meaningful weight loss takes place, the foregut and the hindgut hypotheses. The former holds that the bypass of the proximal intestine, i.e. duodenum and jejunum, prevents the secretion of signals - including nervous transmitters and hormones - promoting insulin resistance, the latter instead states that the delivery of nutrients directly into the ileum stimulates the secretion of hormones improving glucose disposal. The most studied candidate is Glucagon Like Peptide 1 (GLP1). However, while there is unambiguous evidence that GLP-1 stimulates insulin secretion, its direct action in lowering insulin resistance, independently of the effect on weight loss secondary to its satiety action, is utterly controversial. In this review we examine the effects on T2D and gastrointestinal peptide secretion produced by different types of metabolic surgery and by minimally invasive endoscopic surgery, whose utilization for the treatment of obesity and T2D is gaining wider interest and acceptance. Topics: Bariatric Surgery; Blood Glucose; Diabetes Mellitus, Type 2; Gastric Bypass; Glucagon-Like Peptide 1; Humans; Incretins; Insulin; Insulin Resistance; Obesity; Remission Induction | 2018 |
Peptide degradation and the role of DPP-4 inhibitors in the treatment of type 2 diabetes.
Dipeptidyl peptidase-4 (DPP-4) inhibitors are now a widely used, safe and efficacious class of antidiabetic drugs, which were developed prospectively using a rational drug design approach based on a thorough understanding of the endocrinology and degradation of glucagon-like peptide-1 (GLP-1). GLP-1 is an intestinal hormone with potent insulinotropic and glucagonostatic effects and can normalise blood glucose levels in patients with type 2 diabetes, but the native peptide is not therapeutically useful because of its inherent metabolic instability. Using the GLP-1/DPP-4 system and type 2 diabetes as an example, this review summarises how knowledge of a peptide's biological effects coupled with an understanding of the pathways involved in its metabolic clearance can be exploited in a rational, step-by-step manner to develop a therapeutic agent, which is effective and well tolerated, and any side effects are minor and largely predictable. Other peptides with metabolic effects which can also be degraded by DPP-4 will be reviewed, and their potential role as additional mediators of the effects of DPP-4 inhibitors will be assessed. Topics: Blood Glucose; Diabetes Mellitus, Type 2; Dipeptidyl Peptidase 4; Dipeptidyl-Peptidase IV Inhibitors; Glucagon; Glucagon-Like Peptide 1; Humans; Hypoglycemic Agents; Peptides; Proteolysis | 2018 |
Cholecystokinin (CCK) and related adjunct peptide therapies for the treatment of obesity and type 2 diabetes.
Cholecystokinin (CCK) is a hormone secreted from I-cells of the gut, as well as neurons in the enteric and central nervous system, that binds and activates CCK-1 and CCK-2 receptors to mediate its biological actions. To date knowledge relating to the physiological significance of CCK has predominantly focused around induction of short-term satiety. However, CCK has also been highlighted to possess important actions in relation to the regulation of insulin secretion, as well as overall beta-cell function and survival. Consequently, this has led to the development of enzymatically stable, biologically active, CCK peptide analogues with proposed therapeutic promise for both obesity and type 2 diabetes. In addition, several studies have demonstrated metabolic, and therapeutically relevant, complementary biological actions of CCK with those of the incretin hormones GIP and GLP-1, as well as with amylin and leptin. Thus, stable CCK derivatives not only offer promise as potential independent weight-reducing and glucose-lowering drugs, but also as effective adjunctive therapies. This review focuses on the recent and ongoing developments of CCK in the context of new therapies for obesity and type 2 diabetes. Topics: Cholecystokinin; Diabetes Mellitus, Type 2; Gastric Inhibitory Polypeptide; Glucagon; Glucagon-Like Peptide 1; Glucose; Humans; Insulin; Obesity; Peptides; Receptor, Cholecystokinin B | 2018 |
Gut hormone polyagonists for the treatment of type 2 diabetes.
Chemical derivatives of the gut-derived peptide hormone glucagon-like peptide 1 (GLP-1) are among the best-in-class pharmacotherapies to treat obesity and type 2 diabetes. However, GLP-1 analogs have modest weight lowering capacity, in the range of 5-10%, and the therapeutic window is hampered by dose-dependent side effects. Over the last few years, a new concept has emerged: combining the beneficial effects of several key metabolic hormones into a single molecular entity. Several unimolecular GLP-1-based polyagonists have shown superior metabolic action compared to GLP-1 monotherapies. In this review article, we highlight the history of polyagonists targeting the receptors for GLP-1, GIP and glucagon, and discuss recent progress in expanding of this concept to now allow targeted delivery of nuclear hormones via GLP-1 and other gut hormones, as a novel approach towards more personalized pharmacotherapies. Topics: Diabetes Mellitus, Type 2; Gastric Inhibitory Polypeptide; Gastrointestinal Hormones; Glucagon-Like Peptide 1; Glucagon-Like Peptide-1 Receptor; Humans; Incretins; Insulin; Obesity; Receptors, Gastrointestinal Hormone; Receptors, Glucagon | 2018 |
Newer GLP-1 receptor agonists and obesity-diabetes.
Obesity is a major risk factor for type 2 diabetes and may complicate type 1 diabetes. In parallel with the global epidemic of obesity, the incidence of type 2 diabetes is increasing exponentially. To reverse these alarming trends, weight loss becomes a major therapeutic priority in prevention and treatment of type 2 diabetes. Given that glucagon-like peptide-1 receptor agonists (GLP-1 RAs) improve glycaemic control and cause weight loss, they are receiving increasing attention for the treatment of diabetes-obesity. This review discusses current and emerging therapeutic options with GLP-1 RAs and considers the next generation of novel peptide co-agonists with the potential for improved therapeutic outcomes in obesity and type 2 diabetes. Topics: Blood Glucose; Diabetes Mellitus, Type 1; Diabetes Mellitus, Type 2; Glucagon-Like Peptide 1; Glucagon-Like Peptide-1 Receptor; Humans; Hypoglycemic Agents; Obesity; Peptides | 2018 |
Control of insulin secretion by GLP-1.
Stimulation of insulin secretion by glucagon-like peptide-1 (GLP-1) and other gut-derived peptides is central to the incretin response to ingesting nutriments. Analogues of GLP-1, and inhibitors of its breakdown, have found widespread clinical use for the treatment of type 2 diabetes (T2D) and obesity. The release of these peptides underlies the improvements in glycaemic control and disease remission after bariatric surgery. Given therapeutically, GLP-1 analogues can lead to side effects including nausea, which limit dosage. Greater understanding of the interactions between the GLP-1 receptor (GLP-1R) and both the endogenous and artificial ligands therefore holds promise to provide more efficacious compounds. Here, we discuss recent findings concerning the signalling and trafficking of the GLP-1R in pancreatic beta cells. Leveraging "bias" at the receptor towards cAMP generation versus the recruitment of β-arrestins and extracellular signal-regulated kinases (ERK1/2) activation may allow the development of new analogues with significantly improved clinical efficacy. We describe how, unexpectedly, relatively low-affinity agonists, which prompt less receptor internalisation than the parent compound, provoke greater insulin secretion and consequent improvements in glycaemia. Topics: Bariatric Surgery; Diabetes Mellitus, Type 2; Glucagon-Like Peptide 1; Glucagon-Like Peptide-1 Receptor; Humans; Incretins; Insulin; Insulin Secretion; Insulin-Secreting Cells; Ligands; MAP Kinase Signaling System; Obesity; Peptides | 2018 |
A role for Glucagon-Like Peptide-1 in the regulation of β-cell autophagy.
Autophagy is a highly conserved intracellular recycling pathway that serves to recycle damaged organelles/proteins or superfluous nutrients during times of nutritional stress to provide energy to maintain intracellular homeostasis and sustain core metabolic functions. Under these conditions, autophagy functions as a cell survival mechanism but impairment of this pathway can lead to pro-death stimuli. Due to their role in synthesising and secreting insulin, pancreatic β-cells have a high requirement for robust degradation pathways. Recent research suggests that functional autophagy is required to maintain β-cell survival and function in response to high fat diet suggesting a pro-survival role. However, a role for autophagy has also been implicated in the pathogenesis of type 2 diabetes. Thus, the pro-survival vs pro-death role of autophagy in regulating β-cell mass requires discussion. Emerging evidence suggests that Glucagon-Like Peptide-1 (GLP-1) may exert beneficial effects on glucose homeostasis via autophagy-dependent pathways both in pancreatic β-cells and in other cell types. The aim of the current review is to: i) summarise the literature surrounding β-cell autophagy and its pro-death vs pro-survival role in regulating β-cell mass; ii) review the literature describing the impact of GLP-1 on β-cell autophagy and in other cell types; iii) discuss the potential underlying mechanisms. Topics: Autophagy; Diabetes Mellitus, Type 2; Glucagon-Like Peptide 1; Glucose; Homeostasis; Humans; Insulin; Insulin-Secreting Cells; Signal Transduction | 2018 |
Glucagon-like peptide-1 receptor mediated control of cardiac energy metabolism.
Glucagon-like peptide-1 receptor (GLP-1R) agonists are frequently used to improve glycemia in patients with type 2 diabetes (T2D). Recent data from cardiovascular outcomes trials for the GLP-1R agonists, liraglutide and semaglutide, have also demonstrated significant reductions in death rates from cardiovascular causes in patients with T2D. As cardiovascular death is the number one cause of death in patients with T2D, understanding the mechanisms by which GLP-1R agonists such as liraglutide and semaglutide improve cardiac function is essential. Yet despite strong evidence from preclinical and clinical studies supporting the cardioprotective actions of GLP-1R agonists, the precise mechanism(s) by which this drug-class for T2D may produce these beneficial actions remains enigmatic. Negligible GLP-1R expression in ventricular cardiac myocytes suggests that GLP-1R agonist-induced cardioprotection is likely partially attributed to indirect actions on peripheral tissues other than the heart. Because insulin increases glucose oxidation, whereas glucagon increases fatty acid oxidation in the heart, GLP-1R agonist-induced increases and decreases in insulin and glucagon secretion, respectively, may modify cardiac energy metabolism in T2D patients. This may represent a potential mechanism for GLP-1R agonist-induced cardioprotection in T2D, as increases in fatty acid oxidation and decreases in glucose oxidation are frequently observed in the hearts of animals and human subjects with T2D. Topics: Animals; Cardiovascular System; Diabetes Mellitus, Type 2; Energy Metabolism; Fatty Acids; Glucagon; Glucagon-Like Peptide 1; Glucagon-Like Peptide-1 Receptor; Glucose; Humans; Insulin; Myocardium; Oxidation-Reduction | 2018 |
Targeted intestinal delivery of incretin secretagogues-towards new diabetes and obesity therapies.
A new strategy under development for the treatment of type 2 diabetes and obesity is to mimic some of the effects of bariatric surgery by delivering food-related stimuli to the distal gastrointestinal tract where they should enhance the release of gut hormones such as glucagon-like peptide-1 (GLP-1) and peptideYY (PYY). Methods include inhibition of food digestion and absorption in the upper GI tract, or oral delivery of stimuli in capsules or pelleted form to protect them against gastric degradation. A variety of agents have been tested in humans using capsules, microcapsules or pellets, delivering nutrients, bile acids, fatty acids and bitter compounds. This review examines the outcomes of these different approaches and supporting evidence from intestinal perfusion studies. Topics: Bariatric Surgery; Diabetes Mellitus, Type 2; Food-Drug Interactions; Gastrointestinal Tract; Glucagon-Like Peptide 1; Humans; Incretins; Obesity; Peptide YY; Secretagogues | 2018 |
Glucagon-Like Peptide-1 (GLP-1)-Based Therapeutics: Current Status and Future Opportunities beyond Type 2 Diabetes.
Glucagon-like peptide-1 (GLP-1) is secreted by intestinal L-cells following food intake, and plays an important role in glucose homeostasis due to its stimulation of glucose-dependent insulin secretion. Further, GLP-1 is also associated with protective effects on pancreatic β-cells and the cardiovascular system, decreased appetite, and weight loss, making GLP-1 derivatives an exciting treatment for type 2 diabetes and obesity. Despite these benefits, wild-type GLP-1 exhibits a short circulation time due to its poor metabolic stability and rapid renal clearance, and must be administered by injection, making it a poor therapeutic agent. Many strategies have been used to improve the circulation time of GLP-1 (e.g., mutations, unnatural amino acids, depot formulations, use of exendin-4 sequences, and fusions with high-molecular-weight proteins or polymers), with its therapeutic utility further improved by adding agonist activity for gastric inhibitory peptide and glucagon receptors. This minireview focuses on strategies that have been used to improve the pharmacokinetics of GLP-1 and provides an overview of GLP-1-based therapeutics in the pipeline. Topics: Animals; Delayed-Action Preparations; Diabetes Mellitus, Type 2; Exenatide; Glucagon-Like Peptide 1; Half-Life; Humans; Hypoglycemic Agents; Liraglutide; Peptide Hormones; Structure-Activity Relationship | 2018 |
Glucagon like peptide-1 (GLP-1) likes Alzheimer's disease.
Glucagon-like peptide-1 (GLP-1) is a 30 amino acid long peptide hormone derived from the proglucagon gene and secreted in the distal small intestine when food enters the duodenum. GLP-1 is also produced in the central nervous system (CNS), predominantly in the brainstem, and subsequently transported to a large number of regions in the CNS. Neuronal cells in nucleus tractus solitarius (NTS) can synthesize GLP-1 and extends to hypothalamus, some thalamic and cortical areas. A G protein coupled receptor (GPCR) provides the majority of GLP-1 actions. GLP-1 receptor activation triggers some in vivo signaling pathways. GLP-1 receptor agonists (GLP-1 RA) are used in the treatment diabetes and obesity. GLP-1 stimulates insulin secretion, inhibits glucagon secretion, decreases food intake, reduces appetite, delays gastric emptying, provides weight reduction, and protects β cells from apoptosis. Alzheimer's disease (AD) is the most prevalent form of dementia. It is characterized by cognitive insufficiencies and behavioral changes that impact memory and learning abilities, daily functioning and quality of life. Hyperinsulinemia and insulin resistance, which are known as pathophysiological features of the T2DM, have also been demonstrated to have significant impact on cognitive impairment. It is thought that GLP-1 affects neurological and cognitive functions, as well as its regulatory effect on glucose metabolism. The pathophysiological relationship between GLP-1 and AD is discussed in this review. Topics: Alzheimer Disease; Diabetes Mellitus, Type 2; Glucagon-Like Peptide 1; Humans; Peptide Fragments; Quality of Life | 2018 |
Targeting incretin hormones and the ASK-1 pathway as therapeutic options in the treatment of non-alcoholic steatohepatitis.
Non-alcoholic fatty liver disease (NAFLD) is currently one of the leading forms of chronic liver disease, and its rising frequency worldwide has reached epidemic proportions. NAFLD, particularly its progressive variant NASH (non-alcoholic steatohepatitis), can lead to advanced fibrosis, cirrhosis, and HCC. The pathophysiologic mechanisms that contribute to the development and progression of NAFLD and NASH are complex, and as such myriad therapies are under investigation targeting different pathophysiological mechanisms. Incretin-based therapies, including GLP-1RAs and DPP-4 inhibitors and the inhibition of ASK1 pathway have provided two such novel mechanisms in the management of this disease, and will remain focus of this review. Topics: Diabetes Mellitus, Type 2; Dipeptidyl-Peptidase IV Inhibitors; Glucagon-Like Peptide 1; Humans; Incretins; MAP Kinase Kinase Kinase 5; MAP Kinase Signaling System; Non-alcoholic Fatty Liver Disease; Reactive Oxygen Species; Treatment Outcome | 2018 |
Augmentation of glucagon-like peptide-1 receptor signalling by neprilysin inhibition: potential implications for patients with heart failure.
Augmentation of glucagon-like peptide-1 (GLP-1) receptor signalling is an established approach to the treatment of type 2 diabetes. However, endogenous GLP-1 and long-acting GLP-1 receptor analogues are degraded not only by dipeptidyl peptidase-4, but also by neprilysin. This observation raises the possibilities that endogenous GLP-1 contributes to the clinical effects of neprilysin inhibition and that patients concurrently treated with sacubitril/valsartan and incretin-based drugs may experience important drug-drug interactions. Specifically, potentiation of GLP-1 receptor signalling may underlie the antihyperglycaemic actions of sacubitril/valsartan. Neprilysin inhibitors may also be able to augment the effects of long-acting GLP-1 analogues to increase heart rate and myocardial cyclic AMP, and thus, potentiate these deleterious actions; if so, concomitant treatment with GLP-1 receptor agonists may limit the efficacy of neprilysin inhibitors in patients with both heart failure and diabetes. For patients not concurrently treated with GLP-1 analogues, the action of neprilysin to enhance the effects of GLP-1 may be particularly relevant in the brain, where augmentation of GLP-1 and other endogenous peptides may act to inhibit amyloid-induced neuroinflammation and cytotoxicity and improve memory formation and executive functioning. Experimentally, neprilysin inhibitors may also potentiate the effects of endogenous GLP-1 and GLP-1 receptor agonists on blood vessels and the kidney. The role of neprilysin in the metabolism of endogenous GLP-1 and long-acting GLP-1 analogues points to a range of potential pathophysiological effects that may be clinically relevant to patients with heart failure, with or without diabetes. Topics: Blood Glucose; Diabetes Mellitus, Type 2; Glucagon-Like Peptide 1; Heart Failure; Humans; Hypoglycemic Agents; Neprilysin | 2018 |
Mechanisms of Action and Therapeutic Application of Glucagon-like Peptide-1.
Glucagon-like peptide-1 (GLP-1) released from gut enteroendocrine cells controls meal-related glycemic excursions through augmentation of insulin and inhibition of glucagon secretion. GLP-1 also inhibits gastric emptying and food intake, actions maximizing nutrient absorption while limiting weight gain. Here I review the circuits engaged by endogenous versus pharmacological GLP-1 action, highlighting key GLP-1 receptor (GLP-1R)-positive cell types and pathways transducing metabolic and non-glycemic GLP-1 signals. The role(s) of GLP-1 in the benefits and side effects associated with bariatric surgery are discussed and actions of GLP-1 controlling islet function, appetite, inflammation, and cardiovascular pathophysiology are highlighted. Refinement of the risk-versus-benefit profile of GLP-1-based therapies for the treatment of diabetes and obesity has stimulated development of orally bioavailable agonists, allosteric modulators, and unimolecular multi-agonists, all targeting the GLP-1R. This review highlights established and emerging concepts, unanswered questions, and future challenges for development and optimization of GLP-1R agonists in the treatment of metabolic disease. Topics: Animals; Blood Glucose; Diabetes Mellitus, Type 1; Diabetes Mellitus, Type 2; Eating; Glucagon-Like Peptide 1; Glucagon-Like Peptide-1 Receptor; Humans; Hypoglycemic Agents; Insulin; Mice; Obesity; Rats; Weight Gain | 2018 |
[Role of the enterocyte in type 2 diabetes mellitus associated dyslipidemia].
In type 2 diabetes mellitus there is an overproduction of chylomicron in the postprandial state that is associated with increased cardiovascular risk. Current evidence points out a leading role of enterocyte in dyslipidemia of type 2 diabetes mellitus, since it increases the production of apolipoprotein B-48 in response to a raise in plasma free fatty acids and glucose. The chylomicron metabolism is regulated by many factors apart from ingested fat, including hormonal and metabolic elements. More recently, studies about the role of gut hormones, have demonstrated that glucagon-like peptide-1 decreases the production of apolipoprotein B-48 and glucagon-like peptide-2 enhances it. Insulin acutely inhibits intestinal chylomicron production in healthy humans, whereas this acute inhibitory effect on apolipoprotein B-48 production is blunted in type 2 diabetes mellitus. Understanding these emerging regulators of intestinal chylomicron secretion may offer new mechanisms of control for its metabolism and provide novel therapeutic strategies focalized in type 2 diabetes mellitus postprandial hyperlipidemia with the reduction of cardiovascular disease risk. Topics: Chylomicrons; Diabetes Mellitus, Type 2; Dyslipidemias; Enterocytes; Glucagon-Like Peptide 1; Humans; Insulin Resistance; Postprandial Period; Triglycerides | 2018 |
The pleiotropic cardiovascular effects of dipeptidyl peptidase-4 inhibitors.
Patients with Type 2 diabetes have an excess risk for cardiovascular disease. One of the several approaches, included in the guidelines for the management of Type 2 diabetes, is based on dipeptidyl peptidase 4 (DPP-4; also termed CD26) inhibitors, also called gliptins. Gliptins inhibit the degradation of glucagon-like peptide-1 (GLP-1): this effect is associated with increased circulating insulin-to-glucagon ratio, and a consequent reduction of HbA1c. In addition to incretin hormones, there are several proteins that may be affected by DPP-4 and its inhibition: among these some are relevant for the cardiovascular system homeostasis such as SDF-1α and its receptor CXCR4, brain natriuretic peptides, neuropeptide Y and peptide YY. In this review, we will discuss the pathophysiological relevance of gliptin pleiotropism and its translational potential. Topics: Cardiovascular Diseases; Cardiovascular System; Chemokine CXCL12; Diabetes Mellitus, Type 2; Dipeptidyl Peptidase 4; Dipeptidyl-Peptidase IV Inhibitors; Glucagon; Glucagon-Like Peptide 1; Glycated Hemoglobin; Humans; Insulin; Natriuretic Peptide, Brain; Neuropeptide Y; Practice Guidelines as Topic; Proteolysis; Receptors, CXCR4 | 2018 |
Association Between Use of Sodium-Glucose Cotransporter 2 Inhibitors, Glucagon-like Peptide 1 Agonists, and Dipeptidyl Peptidase 4 Inhibitors With All-Cause Mortality in Patients With Type 2 Diabetes: A Systematic Review and Meta-analysis.
The comparative clinical efficacy of sodium-glucose cotransporter 2 (SGLT-2) inhibitors, glucagon-like peptide 1 (GLP-1) agonists, and dipeptidyl peptidase 4 (DPP-4) inhibitors for treatment of type 2 diabetes is unknown.. To compare the efficacies of SGLT-2 inhibitors, GLP-1 agonists, and DPP-4 inhibitors on mortality and cardiovascular end points using network meta-analysis.. MEDLINE, Embase, Cochrane Library Central Register of Controlled Trials, and published meta-analyses from inception through October 11, 2017.. Randomized clinical trials enrolling participants with type 2 diabetes and a follow-up of at least 12 weeks were included, for which SGLT-2 inhibitors, GLP-1 agonists, and DPP-4 inhibitors were compared with either each other or placebo or no treatment.. Data were screened by 1 investigator and extracted in duplicate by 2 investigators. A Bayesian hierarchical network meta-analysis was performed.. The primary outcome: all-cause mortality; secondary outcomes: cardiovascular (CV) mortality, heart failure (HF) events, myocardial infarction (MI), unstable angina, and stroke; safety end points: adverse events and hypoglycemia.. This network meta-analysis of 236 trials randomizing 176 310 participants found SGLT-2 inhibitors (absolute risk difference [RD], -1.0%; hazard ratio [HR], 0.80 [95% credible interval {CrI}, 0.71 to 0.89]) and GLP-1 agonists (absolute RD, -0.6%; HR, 0.88 [95% CrI, 0.81 to 0.94]) were associated with significantly lower all-cause mortality than the control groups. SGLT-2 inhibitors (absolute RD, -0.9%; HR, 0.78 [95% CrI, 0.68 to 0.90]) and GLP-1 agonists (absolute RD, -0.5%; HR, 0.86 [95% CrI, 0.77 to 0.96]) were associated with lower mortality than were DPP-4 inhibitors. DPP-4 inhibitors were not significantly associated with lower all-cause mortality (absolute RD, 0.1%; HR, 1.02 [95% CrI, 0.94 to 1.11]) than were the control groups. SGLT-2 inhibitors (absolute RD, -0.8%; HR, 0.79 [95% CrI, 0.69 to 0.91]) and GLP-1 agonists (absolute RD, -0.5%; HR, 0.85 [95% CrI, 0.77 to 0.94]) were significantly associated with lower CV mortality than were the control groups. SGLT-2 inhibitors were significantly associated with lower rates of HF events (absolute RD, -1.1%; HR, 0.62 [95% CrI, 0.54 to 0.72]) and MI (absolute RD, -0.6%; HR, 0.86 [95% CrI, 0.77 to 0.97]) than were the control groups. GLP-1 agonists were associated with a higher risk of adverse events leading to trial withdrawal than were SGLT-2 inhibitors (absolute RD, 5.8%; HR, 1.80 [95% CrI, 1.44 to 2.25]) and DPP-4 inhibitors (absolute RD, 3.1%; HR, 1.93 [95% CrI, 1.59 to 2.35]).. In this network meta-analysis, the use of SGLT-2 inhibitors or GLP-1 agonists was associated with lower mortality than DPP-4 inhibitors or placebo or no treatment. Use of DPP-4 inhibitors was not associated with lower mortality than placebo or no treatment. Topics: Cardiovascular Diseases; Diabetes Mellitus, Type 2; Dipeptidyl-Peptidase IV Inhibitors; Glucagon-Like Peptide 1; Humans; Hypoglycemic Agents; Sodium-Glucose Transporter 2 Inhibitors | 2018 |
Current therapies and targets for type 2 diabetes mellitus.
The prevalence of type 2 diabetes mellitus (T2DM) has been increasing at an alarming rate. With an increased understanding of the pathophysiology and pathogenesis of T2DM, various new therapeutic options have been developed to target different key defects in T2DM. Incremental innovations of existing therapies either through unprecedented drug combinations, modified drug molecules, or improved delivery systems are capable to nullify some of the undesirable side effects of traditional therapies as well as to enhance effectiveness. The existing administration routes include inhalation, nasal, buccal, parenteral and oral. Newer drug targets such as protein kinase B (Akt/PKB), AMP-activated protein kinase (AMPK), sirtuin (SIRT), and others are novel approaches that act via different mechanisms and possibly treating T2DM of distinct variations and aetiologies. Other therapies such as endobarrier, gene therapy, and stem cell technology utilize advanced techniques to treat T2DM, and the potential of these therapies are still being explored. Gene therapy is plausible to fix the underlying pathology of T2DM instead of using traditional reactive treatments, especially with the debut of Clustered Regularly Interspaced Short Palindromic Repeats-CRISPR associated protein9 (CRISPR-Cas9) gene editing tool. Molecular targets in T2DM are also being extensively studied as it could target the defects at the molecular level. Furthermore, antibody therapies and vaccinations are also being developed against T2DM; but the ongoing clinical trials are relatively lesser and the developmental progress is slower. Although, there are many therapies designed to cure T2DM, each of them has their own advantages and disadvantages. The preference for the treatment plan usually depends on the health status of the patient and the treatment goal. Therefore, an ideal treatment should take patient's compliance, efficacy, potency, bioavailability, and other pharmacological and non-pharmacological properties into account. Topics: Adenylate Kinase; Administration, Inhalation; Animals; CRISPR-Cas Systems; Diabetes Mellitus, Type 2; Drug Design; Fatty Acids; Genetic Therapy; Glucagon-Like Peptide 1; Humans; Insulin; Proto-Oncogene Proteins c-akt; Receptors, G-Protein-Coupled; Sirtuin 1 | 2018 |
Glucagon-like peptide 1 in health and disease.
In healthy individuals, the incretin hormone glucagon-like peptide 1 (GLP1) potentiates insulin release and suppresses glucagon secretion in response to the ingestion of nutrients. GLP1 also delays gastric emptying and increases satiety. In patients with type 2 diabetes mellitus (T2DM), supraphysiological doses of GLP1 normalize the endogenous insulin response during a hyperglycaemic clamp. Owing to the short plasma half-life of native GLP1, several GLP1 receptor agonists (GLP1RAs) with longer half-lives have been developed for the treatment of T2DM. These compounds vary in chemical structure, pharmacokinetics and size, which results in different clinical effects on hyperglycaemia and body weight loss; these variations might also explain the difference in cardiovascular effect observed in large-scale cardiovascular outcome trials, in which certain GLP1RAs were shown to have a positive effect on cardiovascular outcomes. Owing to their metabolic effects, GLP1RAs are also considered for the treatment of several other lifestyle-induced conditions, such as obesity, prediabetes and liver disease. This Review provides insights into the physiology of GLP1 and its involvement in the pathophysiology of T2DM and an overview of the currently available and emerging GLP1RAs. Furthermore, we review the results from the currently available large-scale cardiovascular outcome trials and the use of GLP1RAs for other indications. Topics: Biomarkers; Blood Glucose; Case-Control Studies; Diabetes Mellitus, Type 1; Diabetes Mellitus, Type 2; Female; Follow-Up Studies; Gastric Emptying; Glucagon-Like Peptide 1; Humans; Hypoglycemic Agents; Incretins; Insulin; Male; Reference Values; Treatment Outcome | 2018 |
Capsaicin in Metabolic Syndrome.
Capsaicin, the major active constituent of chilli, is an agonist on transient receptor potential vanilloid channel 1 (TRPV1). TRPV1 is present on many metabolically active tissues, making it a potentially relevant target for metabolic interventions. Insulin resistance and obesity, being the major components of metabolic syndrome, increase the risk for the development of cardiovascular disease, type 2 diabetes, and non-alcoholic fatty liver disease. In vitro and pre-clinical studies have established the effectiveness of low-dose dietary capsaicin in attenuating metabolic disorders. These responses of capsaicin are mediated through activation of TRPV1, which can then modulate processes such as browning of adipocytes, and activation of metabolic modulators including AMP-activated protein kinase (AMPK), peroxisome proliferator-activated receptor α (PPARα), uncoupling protein 1 (UCP1), and glucagon-like peptide 1 (GLP-1). Modulation of these pathways by capsaicin can increase fat oxidation, improve insulin sensitivity, decrease body fat, and improve heart and liver function. Identifying suitable ways of administering capsaicin at an effective dose would warrant its clinical use through the activation of TRPV1. This review highlights the mechanistic options to improve metabolic syndrome with capsaicin. Topics: Adipocytes; Adipose Tissue; AMP-Activated Protein Kinases; Animals; Capsaicin; Diabetes Mellitus, Type 2; Diet; Glucagon-Like Peptide 1; Humans; Insulin Resistance; Metabolic Syndrome; Non-alcoholic Fatty Liver Disease; Obesity; Oxidation-Reduction; PPAR alpha; TRPV Cation Channels; Uncoupling Protein 1 | 2018 |
The effect of glucagon-like peptide 1 and glucagon-like peptide 1 receptor agonists on energy expenditure: A systematic review and meta-analysis.
We reviewed clinical trials addressing the effect of glucacon-like peptide 1 (GLP-1) or GLP-1 receptor agonists (GLP-1RA) on energy expenditure (EE) in adults.. PubMed, Science Direct and Web of Science were searched for clinical trials investigating the effect of GLP-1 or GLP-1RA on EE in adults.. Ten trials (93 participants) assessed the effect of GLP-1 administration over 1 to 48 h and found no change in resting EE (REE). Two out of three trials (62 participants) reported a significant decrease in diet-induced thermogenesis (DIT) following GLP-1 administration. Ten trials with exenatide (10 μg bid, for 10-52 weeks) or liraglutide (0.6, 1.2, 1.8 or 3 mg, for 3 days-52 weeks), with a total of 282 participants, indicated a neutral effect of these GLP-1RA on REE, DIT or physical activity-induced EE. Importantly, the longest trial with GLP-1RA reported a significant increase in REE in response to treatment with both exenatide or liraglutide and most trials reported that GLP-1RA-induced weight loss was not accompanied by decreased REE.. This review indicates that GLP-1 has no short-term effect on REE but may decrease DIT. The GLP-1RA exenatide and liraglutide have a neutral effect on REE, although it is not possible to rule out an increase in REE following prolonged treatment. Topics: Adult; Diabetes Mellitus, Type 2; Energy Metabolism; Female; Glucagon-Like Peptide 1; Glucagon-Like Peptide-1 Receptor; Humans; Hypoglycemic Agents; Male | 2018 |
Targeting the Incretin/Glucagon System With Triagonists to Treat Diabetes.
Glucagonlike peptide 1 (GLP-1) receptor agonists have been efficacious for the treatment of type 2 diabetes due to their ability to reduce weight and attenuate hyperglycemia. However, the activity of glucagonlike peptide 1 receptor-directed strategies is submaximal, and the only potent, sustainable treatment of metabolic dysfunction is bariatric surgery, necessitating the development of unique therapeutics. GLP-1 is structurally related to glucagon and glucose-dependent insulinotropic peptide (GIP), allowing for the development of intermixed, unimolecular peptides with activity at each of their respective receptors. In this review, we discuss the range of tissue targets and added benefits afforded by the inclusion of each of GIP and glucagon. We discuss considerations for the development of sequence-intermixed dual agonists and triagonists, highlighting the importance of evaluating balanced signaling at the targeted receptors. Several multireceptor agonist peptides have been developed and evaluated, and the key preclinical and clinical findings are reviewed in detail. The biological activity of these multireceptor agonists are founded in the success of GLP-1-directed strategies; by including GIP and glucagon components, these multireceptor agonists are thought to enhance GLP-1's activities by broadening the tissue targets and synergizing at tissues that express multiple receptors, such at the brain and pancreatic islet β cells. The development and utility of balanced, unimolecular multireceptor agonists provide both a useful tool for querying the actions of incretins and glucagon during metabolic disease and a unique drug class to treat type 2 diabetes with unprecedented efficacy. Topics: Diabetes Mellitus, Type 2; Gastric Inhibitory Polypeptide; Glucagon-Like Peptide 1; Glucagon-Like Peptide-1 Receptor; Humans; Hypoglycemic Agents; Incretins | 2018 |
The Pharmacokinetic Properties of Glucagon-like Peptide-1 Receptor Agonists and Their Mode and Mechanism of Action in Patients with Type 2 Diabetes.
Once-weekly (OW) glucagon-like peptide-1 receptor agonists (GLP-1 RAs) have demonstrated improved glycemic control in patients with type 2 diabetes (T2D), and some have a number of other benefits, including weight loss, improvements in blood pressure and lipid profiles, and cardiovascular protection. They also provide a therapy option with a low risk of hypoglycemia, an attractive choice for many patients. Molecular structure and pharmacokinetic properties vary among GLP-1 RAs, with some more closely related than others to native glucagon-like peptide-1 (GLP-1). OW GLP-1 RAs have various modifications to their molecular structure that make the molecules resistant to degradation by dipeptidyl peptidase-4 (DPP-4), increasing the half-life of these drugs and making them suitable for OW administration. These differences in the molecular structures and pharmacokinetic properties between the various OW GLP-1 RAs help to explain the differences in efficacy, mechanisms, and safety profiles among the drugs, and these considerations can help primary care physicians to optimize prescribing practices. Topics: Delayed-Action Preparations; Diabetes Mellitus, Type 2; Drug Administration Schedule; Drug Monitoring; Glucagon-Like Peptide 1; Humans; Hypoglycemia; Hypoglycemic Agents; Randomized Controlled Trials as Topic | 2018 |
Clinical Efficacy of Once-weekly Glucagonlike Peptide-1 Receptor Agonists in Patients with Type 2 Diabetes.
Glucagon-like peptide-1 receptor agonists (GLP-1 RAs) are indicated for restoring normoglycemia in patients with type 2 diabetes (T2D). This review analyzed and compared the efficacy results from 30 trials with the once-weekly (OW) GLP-1 RAs albiglutide, dulaglutide, exenatide extended-release (ER) and semaglutide. The 4 OW GLP-1 RAs showed a higher reduction in glycated hemoglobin (HbA1c), fasting plasma glucose (FPG) and body weight, when compared to placebo. Semaglutide significantly reduced the HbA1c level (estimated treatment difference [ETD]: -0.62%; 95% confidence interval [CI], -0.79 to -0.44; P<0.0001), FPG (ETD: -15 mmol/L; 95% CI, -22 to -8.3; P<0.0001) and body weight (ETD: -3.73 kg; 95% CI, -4.53 to -2.93; P<0.0001) compared with exenatide ER. A direct comparison between OW, once-daily (OD), and twice-daily (BD) GLP-1 RAs indicated some trends in efficacy, for example, with OD liraglutide, providing a significant reduction in body weight vs albiglutide (ETD: 1.55 kg; 95% CI, 1.05-2.06; P<0.0001 for albiglutide), dulaglutide (ETD: 0.71 kg; 95% CI, 0.17 -1.26; P=0.011 for dulaglutide), and exenatide ER (ETD: 0.90 kg; 95% CI, 0.39- 1.40; P=0.0005 for exenatide ER). OW GLP-1 RAs also offered improved glycemic control when compared with the dipeptidyl peptidase-4 inhibitor sitagliptin. In conclusion, OW GLP-1 RAs offer a valid therapeutic option for T2D. Topics: Blood Glucose; Delayed-Action Preparations; Diabetes Mellitus, Type 2; Drug Administration Schedule; Drug Monitoring; Glucagon-Like Peptide 1; Glucagon-Like Peptides; Humans; Hypoglycemia; Hypoglycemic Agents; Immunoglobulin Fc Fragments; Randomized Controlled Trials as Topic; Recombinant Fusion Proteins; Treatment Outcome | 2018 |
Safety of Once-weekly Glucagon-like Peptide-1 Receptor Agonists in Patients with Type 2 Diabetes.
Glucagon-like peptide-1 receptor agonists (GLP-1 RAs) have been found efficacious in the treatment of type 2 diabetes (T2D), demonstrating the ability to lower HbA1c, and having the potential for inducing weight loss and reducing the risk of hypoglycemia, compared with other antihyperglycemic agents. Currently, 4 once-weekly (OW) GLP-1 RAs are approved: albiglutide, dulaglutide, exenatide ER, and recently, semaglutide. This review compares the relative safety of OW GLP-1 RAs, as well as their safety in comparison to other antihyperglycemic agents, using safety data reported in key sponsor-led phase 3 studies of the 4 OW GLP-1 RAs. The favorable safety profiles of OW GLP-1 RAs, added to their efficacy and the favorable weekly dosing regimen, make these agents appropriate options for patients with T2D. However, there are key differences within this class of drugs in macrovascular, microvascular, gastrointestinal and injection-site reaction adverse events, and these should be considered when healthcare providers are prescribing therapy. Topics: Blood Glucose; Delayed-Action Preparations; Diabetes Mellitus, Type 2; Drug Administration Schedule; Drug Monitoring; Exenatide; Glucagon-Like Peptide 1; Glucagon-Like Peptides; Humans; Hypoglycemia; Hypoglycemic Agents; Immunoglobulin Fc Fragments; Randomized Controlled Trials as Topic; Recombinant Fusion Proteins; Treatment Outcome | 2018 |
Cardiovascular and Renal Outcomes of Newer Anti-Diabetic Medications in High-Risk Patients.
We review the cardiovascular and renal outcomes and safety of newer anti-diabetic medications in high-risk patients. We examine the outcomes of the IRIS, EMPA-REG OUTCOME, CANVAS, LEADER, SAVOR-TIMI 53, and EXAMINE trials demonstrating the cardiovascular and renal benefits of thiazolidinediones, SGLT2 inhibitors, GLP-1 agonists, and DPP-4 inhibitors.. Diabetes mellitus is a leading risk factor for cardiovascular disease with rising prevalence and disease burden. The microvascular and macrovascular complications of diabetes are well-recognized and include increased risk of cardiovascular disease, myocardial infarction, and stroke. Newer diabetes medications have demonstrated significant cerebrovascular, cardiovascular, renal, and mortality benefits in high risk patients with diabetes. In addition to their glucose-lowering effects, the thiazolidinedione pioglitazone, SGLT2 inhibitors, GLP-1 agonist, and DPP-4 inhibitors have demonstrated significant cerebrovascular, cardiovascular, renal, and mortality effects. The outcomes and safety data of newer diabetes medications from recent trials demonstrate cardiovascular and mortality effects with significant implications for clinical practice. Topics: Cardiovascular Diseases; Cardiovascular System; Diabetes Mellitus, Type 2; Dipeptidyl-Peptidase IV Inhibitors; Glucagon-Like Peptide 1; Humans; Hypoglycemic Agents; Kidney; Pioglitazone; Randomized Controlled Trials as Topic; Risk Factors; Sodium-Glucose Transporter 2 Inhibitors | 2018 |
Treatment of 'Diabesity': Beyond Pharmacotherapy.
Obesity is a prominent risk factor for type 2 diabetes. Management of type 2 diabetes requires weight management in addition to glycemic parameters. For obese type 2 diabetes patients, metformin, Sodium-glucose co-transporter-2 inhibitors or Glucagon-Like Peptide-1 Receptor Agonists should be prescribed as the first priority for controlling both hyperglycemia and body weight or fat distribution. The combination of these drugs with sulfonylureas, thiazolidinediones, and insulin may also be required in chronic cases. These drugs cause weight gain. Fortunately, many phytochemicals having a beneficial effect on diabetes and obesity, have minimum side-effects as compared to synthetic drugs. This review discusses the treatment strategies for controlling glycemia and weight management, with the focus on anti-diabetic drugs and phytochemicals. Glucagonostatic role, activation of Adenosine monophosphate-activated protein kinase and adipocyte targeting potential of anti-diabetic drugs and phytochemicals are also discussed. Topics: Diabetes Mellitus, Type 2; Glucagon-Like Peptide 1; Humans; Hypoglycemic Agents; Metformin; Obesity; Phytochemicals; Sodium-Glucose Transporter 2 Inhibitors; Sulfonylurea Compounds; Thiazolidinediones | 2018 |
Semaglutide: The Newest Once-Weekly GLP-1 RA for Type 2 Diabetes.
To review efficacy and safety of the glucagon-like peptide-1 receptor agonist (GLP-1 RA) semaglutide for type 2 diabetes (T2D).. A literature search of PubMed/MEDLINE and EMBASE using the term semaglutide was completed through April 2018. A search of clinicaltrials.gov was also conducted.. English-language studies assessing the efficacy and/or safety of semaglutide were evaluated.. Semaglutide is a newly approved GLP-1 RA for the treatment of T2D. Administered once weekly at a dose of 0.5 or 1 mg, it has been compared with placebo, sitagliptin, insulin glargine, a combination of oral antidiabetic therapies, and 2 GLP-1 RAs, exenatide ER and dulaglutide, and demonstrated greater efficacy compared with these therapies. Published data from studies ranging from 30 to 104 weeks duration demonstrate efficacy with decreases in hemoglobin A1C (A1C) ranging from 1.1% to 2.2%. Studies show reductions in weight from 1.4 to 6.5 kg. Semaglutide demonstrated a reduction in the composite outcome of cardiovascular (CV) death, nonfatal myocardial infarction, or nonfatal stroke compared with placebo in patients at high risk of CV events (hazard ratio = 0.74; P = 0.02). Common adverse effects include nausea, vomiting, and diarrhea as seen with other GLP-1 RAs. Relevance to Patient Care and Clinical Practice: Semaglutide represents an attractive GLP-1 RA considering its A1C and weight reduction. It provides patient convenience and high patient satisfaction.. Semaglutide is an appealing option for the treatment of T2D as a once-weekly GLP-1 RA with established glycemic, CV, and weight benefits. Topics: Blood Glucose; Body Weight; Clinical Trials, Phase III as Topic; Diabetes Mellitus, Type 2; Drug Administration Schedule; Glucagon-Like Peptide 1; Glucagon-Like Peptides; Glycated Hemoglobin; Humans; Hypoglycemic Agents; Weight Loss | 2018 |
New Injectable Agents for the Treatment of Type 2 Diabetes Part 2-Glucagon-Like Peptide-1 (GLP-1) Agonists.
The US Food and Drug Administration has recently approved several new glucagon-like peptide-1 (GLP-1) agonists alone and in combination with various insulin products. The second of 2 articles in a series, this review will describe the potential advantages and disadvantages of the GLP-1 agonist class of products. Topics: Diabetes Mellitus, Type 2; Glucagon-Like Peptide 1; Glucagon-Like Peptide-1 Receptor; Humans; Hypoglycemic Agents | 2018 |
Battle of GLP-1 delivery technologies.
Glucagon-like peptide-1 receptor agonists (GLP-1 RAs) belong to an important therapeutic class for treatment of type 2 diabetes. Six GLP-1 RAs, each utilizing a unique drug delivery strategy, are now approved by the Food and Drug Administration (FDA) and additional, novel GLP-1 RAs are still under development, making for a crowded marketplace and fierce competition among the manufacturers of these products. As rapid elimination is a major challenge for clinical application of GLP-1 RAs, various half-life extension strategies have been successfully employed including sequential modification, attachment of fatty-acid to peptide, fusion with human serum albumin, fusion with the fragment crystallizable (Fc) region of a monoclonal antibody, sustained drug delivery systems, and PEGylation. In this review, we discuss the scientific rationale of the various half-life extension strategies used for GLP-1 RA development. By analyzing and comparing different approved GLP-1 RAs and those in development, we focus on assessing how half-life extending strategies impact the pharmacokinetics, pharmacodynamics, safety, patient usability and ultimately, the commercial success of GLP-1 RA products. We also anticipate future GLP-1 RA development trends. Since similar drug delivery strategies are also applied for developing other therapeutic peptides, we expect this case study of GLP-1 RAs will provide generalizable concepts for the rational design of therapeutic peptides products with extended duration of action. Topics: Diabetes Mellitus, Type 2; Drug Delivery Systems; Glucagon-Like Peptide 1; Glucagon-Like Peptide-1 Receptor; Humans; Hypoglycemic Agents | 2018 |
Albiglutide for the management of type 2 diabetes.
Albiglutide is a long acting GLP-1 receptor agonist (GLP-1 RA) administered by weekly injection and approved for use in type 2 diabetes. It has less gastrointestinal side effects than other GLP-1 RAs in current use but does not improve HbA1c or promote weight loss to the same extent as some competitor agents. Area covered: The current use of albiglutide is discussed. The review encompassed a search of PubMed and a thorough analysis of the European Union and US Food and Drug Administration approval documents. Expert opinion: Unlike competitor agents, the gastrointestinal side effects of albiglutide are not much greater than placebo. It has been studied and appears safe at all stages of renal failure. There exists concern about an imbalance of pancreatitis cases in the approval program as well as injection site reactions which led to discontinuance of therapy in up to 2% of participants. A large long-term study is now underway to determine if albiglutide, with its relatively favorable GI tolerance, has a place in the treatment of patients with increased risk of cardiovascular events. At present, albiglutide is a safe agent to introduce GLP-1 RA treatment into the regimen for type 2 diabetes patients and may be the GLP-1 agent of choice in patients with renal insufficiency. Topics: Diabetes Mellitus, Type 2; Glucagon-Like Peptide 1; Glucagon-Like Peptide-1 Receptor; Humans; Hypoglycemic Agents | 2018 |
Comparison of New Glucose-Lowering Drugs on Risk of Heart Failure in Type 2 Diabetes: A Network Meta-Analysis.
The authors conducted a systematic review and network meta-analysis of placebo-controlled, randomized clinical trials in the post-Food and Drug Administration (FDA) guidance era to formally compare the effects of 3 new classes of glucose-lowering drugs on hospitalization for heart failure (HF) in type 2 diabetes mellitus.. The 2008 FDA Guidance for Industry launched an era of cardiovascular outcome trials for new glucose-lowering drugs in T2DM, including glucagon-like peptide (GLP)-1 agonists, dipeptidyl peptidase (DPP)-4 inhibitors, and sodium glucose co-transporter (SGLT)-2 inhibitors.. We searched Embase, PubMed, Cochrane Library, and clinicaltrials.gov between December 1, 2008, and November 24, 2017, for randomized placebo-controlled trials, and performed network meta-analyses by Bayesian approach using Markov-chain Monte Carlo simulation method to compare the effects of glucose-lowering drugs on risk of HF hospitalization and estimate the probability that each treatment is the most effective.. Nine studies were identified, yielding data on 87,162 participants. In the network meta-analysis, SGLT-2 inhibitors yielded the greatest risk reduction for HF hospitalization compared with placebo (relative risk [RR]: 0.56; 95% CrI [credibility interval]: 0.43 to 0.72). Moreover, SGLT-2 inhibitors were associated with significant risk reduction in pairwise comparisons with both GLP-1 agonists (RR: 0.59; 95% CrI: 0.43 to 0.79) and DPP-4 inhibitors (RR: 0.50; 95% CrI: 0.36 to 0.70). Ranking of the classes revealed 99.6% probability of SGLT-2 inhibitors being the optimal treatment for reducing the risk of this outcome, followed by GLP-1 agonists (0.27%) and DPP-4 inhibitors (0.1%).. Current evidence suggests that SGLT-2 inhibitors are more effective than either GLP-1 agonists or DPP-4 inhibitors for reducing the risk of hospitalization for HF in type 2 diabetes mellitus. Topics: Diabetes Mellitus, Type 2; Dipeptidyl-Peptidase IV Inhibitors; Glucagon-Like Peptide 1; Heart Failure; Humans; Hypoglycemic Agents; Sodium-Glucose Transporter 2 Inhibitors; Treatment Outcome | 2018 |
[Progress of Research on Mechanism of Acupuncture for Diabetes Mellitus].
Acupuncture has been used to treat diabetes mellitus (DM) for more than one thousand years. In the present paper, we review new progress of researches on the underlying mechanism of acupuncture intervention for DM. Results showed that acupuncture intervention can relieve DM by 1) reducing body weight through up-regulating leptin level, suppressing insulin resistance and appetite to reduce food intake possibly by way of down-regulating expression of neuropeptide Y in the hypothalamus, retarding gastric emptying velocity, increasing small intestinal peristalsis, raising plasma levels of glucagon-like peptide-1 (GLP-1) and peptide YY, etc.; 2) improving pancreas function, raising insulin sensitivity to improve insulin resistance possibly by activating AMP-activated protein kinase and sirtuin 1/ peroxisome proliferator-activated receptor γ coactivator 1 α signaling, up-regulating activities of cholinergic nerve activity and nitric oxide synthase, and inhibiting apoptosis of pancreatic beta-cells; 3) lowering blood glucose possibly by increasing anaerobic glucose metabolism, regulating activities of vagal and sympathetic nerves; 4) adjusting the levels of related hormones such as melatonin, insulin, glucocorticold, epinephrine, etc. Moreover, acupuncture treatment combined with hypoglycemic drugs has a synergic effect in lowering blood glucose, suggesting a potentially effective approach for improving DM and being worthy of further studying in clinical practice. Topics: Acupuncture Therapy; Diabetes Mellitus, Type 2; Glucagon-Like Peptide 1; Humans; Hypoglycemic Agents; Insulin | 2018 |
Glucagon-Like Peptide-1 Receptor Agonists and Cardiovascular Risk Reduction in Type 2 Diabetes Mellitus: Is It a Class Effect?
Mimetics and analogs that extend the half-life of native glucagon-like peptide-1 (GLP-1), i.e., glucagon-like peptide-1 receptor agonists (GLP-1 RAs), at therapeutic doses, are indicated as adjuncts to diet and exercise, to improve glycemic control in adults with type 2 diabetes mellitus (T2DM). In patients with T2DM, GLP-1 RAs not only affect improvements in impaired beta cell and alpha cell function, suppress appetite, and induce weight loss but also possess multiple cardiovascular protective properties that potentially have a beneficial impact on atherosclerotic cardiovascular disease (ASCVD) morbidity and mortality.. Required to demonstrate CV safety, compared to standard-of-care antidiabetic therapies, GLP-1 RAs have revealed statistically significant non-inferiority (p < 0.001), among CV outcome trials (CVOTs) thus far completed. Once-daily liraglutide and once-weekly semaglutide demonstrated significant superiority (p = 0.01 and p = 0.02, respectively), reducing 3-point composite major adverse cardiovascular events (MACE) in extreme risk secondary prevention adults with T2DM. Once-weekly exenatide demonstrated only a non-significant (p = 0.06) favorable trend for CV superiority, possibly due to in-trial mishaps, including placebo drop-ins with other CV protective medications. The short half-life lixisenatide was neutral (p = 0.81) in reducing MACE, most likely due to ineffective once-daily dosing. Structural differences among GLP-1 mimetics and analogs may explain potency differences in both A1C reduction and weight loss that may parallel important cardiovascular protective properties of the GLP-1 RA class. Significant superiority in reducing 3-point composite MACE in adults with T2DM with GLP-1 RAs has been limited to liraglutide and semaglutide. Careful attention to within-trial drop-in of cardioprotective antidiabetic agents assuring equipoise between placebo and investigational product groups might demonstrate significant MACE risk reduction with once-weekly exenatide. Maintenance of 24-h circulating levels, by an alternative administration method, may resurrect lixisenatide as a cardioprotective agent. Before a GLP-1 RA bioequivalence "class effect" claim for composite MACE risk reduction superiority can be fully discussed, we are obliged to wait for the pending results of CVOTs with other GLP-1 RAs, particularly albiglutide and dulaglutide, where steric hindrance may potentially inhibit full mimicry of pharmacologic GLP-1. Topics: Cardiovascular Diseases; Diabetes Mellitus, Type 2; Drug Administration Schedule; Glucagon-Like Peptide 1; Glucagon-Like Peptide-1 Receptor; Humans; Hypoglycemic Agents; Randomized Controlled Trials as Topic; Risk Factors; Risk Reduction Behavior | 2018 |
Cardiovascular effects of antidiabetic drugs.
Type 2 diabetes mellitus is a common and severe chronic metabolic disease, which confers increased risk of cardiovascular disease and mortality. During the last decade a large number of new drugs within the classes dipeptidyl peptidase 4 (DPP-4) inhibitors (DPP-4Is), glucagon-like peptide 1 (GLP-1) receptor agonists (GLP-1RAs) and sodium/glucose cotransporter 2 (SGLT-2) inhibitors (SGLT-2Is) have been developed and tested in nine large-scale cardiovascular outcome trials (CVOTs). Here we review the evidence behind antihyperglycemic treatment of patients with type 2 diabetes with a particular focus on compiling and summarizing the evidence of hard clinical endpoints stemming from these large CVOTs. Topics: Cardiovascular Diseases; Diabetes Mellitus, Type 2; Dipeptidyl-Peptidase IV Inhibitors; Glucagon-Like Peptide 1; Humans; Hypoglycemic Agents; Sodium-Glucose Transporter 2; Sodium-Glucose Transporter 2 Inhibitors | 2018 |
Recent updates on GLP-1 agonists: Current advancements & challenges.
Glucagon-like peptide (GLP)-1 is an incretin hormone exhibiting several pharmacological actions such as neuroprotection, increased cognitive function, cardio-protection, decreased hypertension, suppression of acid secretion, increase in lyposis, and protection from inflammation. The most potent actions are glucose-dependent insulinotropic and glucagonostatic actions, stimulation of β-cell proliferation, enhanced insulin secretion and reduced weight gain in patients with type-2 diabetes pertaining to blood glucose control. Despite all these actions, its short half-life (around 2∼min) and degradation by a dipeptidyl peptidase-4 enzyme (DPP-4) limits the therapeutic utility of GLP1. In this review, we have discussed DPP IV-resistant analogs of GLP-1 currently present in clinical trials such as Exenatide, Liraglutide, Semaglutide, Efpeglenatide, Exenatide ER, Ittca 650 (Intarcia), Dulaglutide, Albiglutide, and Lixisenatide. Moreover, we have also discussed in detail the pharmacology, signaling mechanisms, and pharmacokinetic properties (Cmax, Tmax, T Topics: Animals; Diabetes Mellitus, Type 2; Glucagon-Like Peptide 1; Humans; Hypoglycemic Agents; Signal Transduction | 2018 |
Bidirectional Relationship between Gastric Emptying and Plasma Glucose Control in Normoglycemic Individuals and Diabetic Patients.
Gastric emptying and glycemic control pathways are closely interrelated processes. Gastric chyme is transferred into the duodenum with velocities depending on its solid or liquid state, as well as on its caloric and nutritional composition. Once nutrients enter the intestine, the secretion of incretins (hormonal products of intestinal cells) is stimulated. Among incretins, glucagon-like peptide-1 (GLP-1) has multiple glycemic-regulatory effects that include delayed gastric emptying, thus triggering a feedback loop lowering postprandial serum glucose levels. Glycemic values also influence gastric emptying; hyperglycemia slows it down, and hypoglycemia accelerates it, both limiting glycemic fluctuations. Disordered gastric emptying in diabetes mellitus is understood today as a complex pathophysiological condition, with both irreversible and reversible components and high intra- and interindividual variability of time span and clinical features. While limited delays may be useful for reducing postprandial hyperglycemias, severely hindered gastric emptying may be associated with higher glycemic variability and worsened long-term glycemic control. Therapeutic approaches for both gastric emptying and glycemic control include dietary modifications of meal structure or content and drugs acting as GLP-1 receptor agonists. In the foreseeable future, we will probably witness a wider range of dietary interventions and more incretin-based medications used for restoring both gastric emptying and glycemic levels to nearly physiological levels. Topics: Blood Glucose; Diabetes Mellitus, Type 2; Gastric Emptying; Glucagon; Glucagon-Like Peptide 1; Humans; Insulin; Postprandial Period | 2018 |
Clinical and Investigative Endocrinology and Diabetes.
Topics: Choice Behavior; Diabetes Mellitus, Type 2; Education, Medical, Continuing; Endocrinology; Glucagon-Like Peptide 1; Humans; Hypoglycemic Agents; Patient Selection; Practice Patterns, Physicians'; Risk Assessment | 2018 |
Synthetic and phytocompounds based dipeptidyl peptidase-IV (DPP-IV) inhibitors for therapeutics of diabetes.
Currently antidiabetic therapeutic strategies are mainly based on synthetic hypoglycemic agent. Antidiabetic drugs are associated with significant adverse effects of hypoglycemia, dysfunction of insulin and weight gain. Nowadays, the novel Dipeptidyl peptidase-IV (DPP-IV) inhibitors unique approach for the management of diabetes has been considered to be safe, as DPP-IV inhibitors reduce blood glucose level by monitoring hyperglycemia including positive effects on body weight as it remains neutral, improves glycated hemoglobin levels and do not induce hypoglycemia. Inhibitors help to protect degradation of Glucagon-like peptide-1 (GLP-1) and gastric inhibitory peptide (GIP), gut hormones which helps to suppresses postprandial glucagon release, delay gastric emptying and regulate satiety. Therefore, the innovation of DPP-IV inhibitor based drugs regulates activity of incretin hormones such as GLP-1 and GIP. Commercially available DPP-IV inhibitors are chemically synthesized with good therapeutic value. However, the durability and long-term safety of DPP-IV inhibitors remains to be established. On the other hand, phytocompounds-based DPP-IV inhibitors are alternative and safe to use as compared to synthetic. Numerous novel antidiabetic compounds and group of compounds emerging in clinical development are through DPP-IV inhibition. This review summarized recent progress made on DPP-IV inhibitors from both synthetic as well as from natural sources. Topics: Diabetes Mellitus, Type 2; Dipeptidyl Peptidase 4; Dipeptidyl-Peptidase IV Inhibitors; Gastric Inhibitory Polypeptide; Glucagon-Like Peptide 1; Humans; Hypoglycemic Agents; Insulin; Molecular Structure | 2017 |
Fixed ratio combinations of glucagon like peptide 1 receptor agonists with basal insulin: a systematic review and meta-analysis.
Basal insulin controls primarily fasting plasma glucose but causes hypoglycaemia and weight gain, whilst glucagon like peptide 1 receptor agonists induce weight loss without increasing risk for hypoglycaemia. We conducted a systematic review and meta-analysis of randomised controlled trials to investigate the efficacy and safety of fixed ratio combinations of basal insulin with glucagon like peptide 1 receptor agonists.. We searched Medline, Embase, and the Cochrane Library as well as conference abstracts up to December 2016. We assessed change in haemoglobin A. We included eight studies with 5732 participants in the systematic review. Switch from basal insulin to fixed ratio combinations with a glucagon like peptide 1 receptor agonist was associated with 0.72% reduction in haemoglobin A. Fixed ratio combinations of basal insulin with glucagon like peptide 1 receptor agonists improve glycaemic control whilst balancing out risk for hypoglycaemia and gastrointestinal side effects. Topics: Blood Glucose; Diabetes Mellitus, Type 2; Drug Combinations; Glucagon-Like Peptide 1; Humans; Hypoglycemic Agents; Insulin; Insulin, Long-Acting; Liraglutide | 2017 |
Albiglutide (Tanzeum) for Diabetes Mellitus.
Topics: Diabetes Mellitus, Type 2; Glucagon-Like Peptide 1; Humans; Incretins | 2017 |
Glucose kinetics: an update and novel insights into its regulation by glucagon and GLP-1.
Glucagon and GLP-1 share the same origin (i.e., proglucagon); primarily GLP-1 is generated from intestinal L-cells and glucagon from pancreatic α-cell, but intestinal glucagon and pancreatic GLP-1 secretion is likely. Glucose kinetics are tightly regulated by pancreatic hormones insulin and glucagon, but other hormones, including glucagon-like peptide-1 (GLP-1), also play an important role. The purpose of this review is to describe the recent findings on the mechanisms by which these two hormones regulate glucose kinetics.. Recent findings showed new important mechanisms of action of glucagon and GLP-1 in the regulation of glucose metabolism. Knock out of glucagon receptors protects against hyperglycemia without causing hypoglycemia. GLP-1 not only stimulates insulin secretion, but it has also an independent effect on the liver and inhibits glucose production. Moreover, when coinfused with glucagon, GLP-1 limits the hyperglycemic effects. Both hormones have also central effects on gastric emptying (delayed), intestinal motility (reduced), and satiety (increased).. The implications of these findings are very important for the management of type 2 diabetes given that GLP-1 receptor agonist are currently approved for the treatment of hyperglycemia and glucagon receptor antagonists and GLP-1/glucagon dual agonists are under development. Topics: Animals; Diabetes Mellitus, Type 2; Fasting; Gastric Emptying; Gastrointestinal Motility; Glucagon; Glucagon-Like Peptide 1; Glucagon-Like Peptide-1 Receptor; Gluconeogenesis; Glucose; Homeostasis; Humans; Hyperglycemia; Kinetics; Liver; Receptors, Glucagon; Satiation | 2017 |
Cardiovascular safety outcomes of new antidiabetic therapies.
The cardiovascular safety outcomes of newer antidiabetic agents were reviewed.. Seven randomized, placebo-controlled trials involving patients with type 2 diabetes mellitus with or at risk for cardiovascular disease were reviewed. The trials examined the cardiovascular safety outcomes of the following agents: alogliptin, saxagliptin, and sitagliptin (dipeptidyl peptidase-4 [DPP-4] inhibitors); liraglutide, lixisenatide, and semaglutide (glucagon-like peptide-1 agonists); and empagliflozin (a sodium glucose cotransport-2 inhibitor). The DPP-4 inhibitor and lixisenatide trials showed a neutral effect on cardiovascular events (composite of cardiovascular death, myocardial infarction, or stroke, with or without unstable angina). Empagliflozin showed a significant reduction in cardiovascular events, cardiovascular death, all-cause death, and hospitalization due to heart failure (HF); liraglutide reduced cardiovascular events, cardiovascular death, and all-cause death, and semaglutide reduced cardiovascular events and nonfatal stroke. Most studies showed a neutral effect of the drug on hospitalization for HF; however, saxagliptin and alogliptin (in the subgroups of patients without a history of HF) showed a significant increase while empagliflozin showed a significant reduction in hospitalizations for HF. The data for empagliflozin, liraglutide, and semaglutide are compelling; however, further studies are necessary to confirm observed benefits and better characterize long-term safety and their use as a strategy to reduce cardiovascular events.. A review of cardiovascular safety outcomes for new antidiabetic agents found that saxagliptin and alogliptin were associated with an increase in hospitalization for HF. The data for empagliflozin, liraglutide, and semaglutide showed a reduction in cardiovascular events and death or a neutral effect on cardiovascular endpoints. Topics: Animals; Cardiovascular Diseases; Diabetes Mellitus, Type 2; Dipeptidyl-Peptidase IV Inhibitors; Glucagon-Like Peptide 1; Humans; Hypoglycemic Agents; Randomized Controlled Trials as Topic; Sodium-Glucose Transporter 2 Inhibitors; Treatment Outcome | 2017 |
Dipeptidyl-peptidase (DPP)-4 inhibitors and glucagon-like peptide (GLP)-1 analogues for prevention or delay of type 2 diabetes mellitus and its associated complications in people at increased risk for the development of type 2 diabetes mellitus.
The projected rise in the incidence of type 2 diabetes mellitus (T2DM) could develop into a substantial health problem worldwide. Whether dipeptidyl-peptidase (DPP)-4 inhibitors or glucagon-like peptide (GLP)-1 analogues are able to prevent or delay T2DM and its associated complications in people at risk for the development of T2DM is unknown.. To assess the effects of DPP-4 inhibitors and GLP-1 analogues on the prevention or delay of T2DM and its associated complications in people with impaired glucose tolerance, impaired fasting blood glucose, moderately elevated glycosylated haemoglobin A1c (HbA1c) or any combination of these.. We searched the Cochrane Central Register of Controlled Trials; MEDLINE; PubMed; Embase; ClinicalTrials.gov; the World Health Organization (WHO) International Clinical Trials Registry Platform; and the reference lists of systematic reviews, articles and health technology assessment reports. We asked investigators of the included trials for information about additional trials. The date of the last search of all databases was January 2017.. We included randomised controlled trials (RCTs) with a duration of 12 weeks or more comparing DPP-4 inhibitors and GLP-1 analogues with any pharmacological glucose-lowering intervention, behaviour-changing intervention, placebo or no intervention in people with impaired fasting glucose, impaired glucose tolerance, moderately elevated HbA1c or combinations of these.. Two review authors read all abstracts and full-text articles and records, assessed quality and extracted outcome data independently. One review author extracted data which were checked by a second review author. We resolved discrepancies by consensus or the involvement of a third review author. For meta-analyses, we planned to use a random-effects model with investigation of risk ratios (RRs) for dichotomous outcomes and mean differences (MDs) for continuous outcomes, using 95% confidence intervals (CIs) for effect estimates. We assessed the overall quality of the evidence using the GRADE instrument.. We included seven completed RCTs; about 98 participants were randomised to a DPP-4 inhibitor as monotherapy and 1620 participants were randomised to a GLP-1 analogue as monotherapy. Two trials investigated a DPP-4 inhibitor and five trials investigated a GLP-1 analogue. A total of 924 participants with data on allocation to control groups were randomised to a comparator group; 889 participants were randomised to placebo and 33 participants to metformin monotherapy. One RCT of liraglutide contributed 85% of all participants. The duration of the intervention varied from 12 weeks to 160 weeks. We judged none of the included trials at low risk of bias for all 'Risk of bias' domains and did not perform meta-analyses because there were not enough trials.One trial comparing the DPP-4 inhibitor vildagliptin with placebo reported no deaths (very low-quality evidence). The incidence of T2DM by means of WHO diagnostic criteria in this trial was 3/90 participants randomised to vildagliptin versus 1/89 participants randomised to placebo (very low-quality evidence). Also, 1/90 participants on vildagliptin versus 2/89 participants on placebo experienced a serious adverse event (very low-quality evidence). One out of 90 participants experienced congestive heart failure in the vildagliptin group versus none in the placebo group (very low-quality evidence). There were no data on non-fatal myocardial infarction, stroke, health-related quality of life or socioeconomic effects reported.All-cause and cardiovascular mortality following treatment with GLP-1 analogues were rarely reported; one trial of exenatide reported that no participant died. Another trial of liraglutide 3.0 mg showed that 2/1501 in the liraglutide group versus 2/747 in the placebo group died after 160 weeks of treatment (very low-quality evidence).The incidence of T2DM following treatment with liraglutide 3.0 mg compared to placebo after 160 weeks was 26/1472 (1.8%) participants randomised to liraglutide versus 46/738 (6.2%) participants randomised to placebo (very low-quality evidence). The trial established the risk for (diagnosis of) T2DM as HbA1c 5.7% to 6.4% (6.5% or greater), fasting plasma glucose 5.6 mmol/L or greater to 6.9 mmol/L or less (7.0 mmol/L or greater) or two-hour post-load plasma glucose 7.8 mmol/L or greater to 11.0 mmol/L (11.1 mmol/L). Altogether, 70/1472 (66%) participants regressed from intermediate hyperglycaemia to normoglycaemia compared with 268/738 (36%) participants in the plac. There is no firm evidence that DPP-4 inhibitors or GLP-1 analogues compared mainly with placebo substantially influence the risk of T2DM and especially its associated complications in people at increased risk for the development of T2DM. Most trials did not investigate patient-important outcomes. Topics: Adamantane; Blood Glucose; Diabetes Mellitus, Type 2; Dipeptidyl-Peptidase IV Inhibitors; Exenatide; Fasting; Glucagon-Like Peptide 1; Glucose Intolerance; Glycated Hemoglobin; Humans; Hypoglycemic Agents; Incretins; Liraglutide; Metformin; Nitriles; Peptides; Pyrrolidines; Randomized Controlled Trials as Topic; Risk Factors; Venoms; Vildagliptin | 2017 |
Pharmacologic Treatment of Dyslipidemia in Diabetes: A Case for Therapies in Addition to Statins.
The purpose of the study is to review the use of statins and the role of both non-statin lipid-lowering agents and diabetes-specific medications in the treatment of diabetic dyslipidemia.. Statins have a primary role in the treatment of dyslipidemia in people with type 2 diabetes, defined as triglyceride levels >200 mg/dl and HDL cholesterol levels <40 mg/dL. A number of clinical trials suggest that treatment with a fibrate may reduce cardiovascular events. However, the results of these trials are inconsistent, probably because many of their participants did not have dyslipidemia. The choice of medications used to treat diabetes can have major implications regarding management of dyslipidemia; metformin, GLP-1 agonists, and pioglitazone all have favorable lipid effects. These agents, as well as the new SGLT2 inhibitors, may reduce cardiovascular events. Management of dyslipidemia in people with type 2 diabetes should start with statin therapy and optimal glycemic control with agents that have favorable lipid and cardiovascular effects. We believe that there is a role for adding fenofibrate to moderate-intensity statins in selected patients with true dyslipidemia. We propose an algorithm for selecting add-on medications for diabetes (after metformin) based on lipid status. Topics: Cardiovascular Diseases; Diabetes Mellitus, Type 2; Dyslipidemias; Fenofibrate; Glucagon-Like Peptide 1; Humans; Hydroxymethylglutaryl-CoA Reductase Inhibitors; Hypolipidemic Agents; Metformin; Pioglitazone; Thiazolidinediones | 2017 |
A review on cardiovascular effects of newer hypoglycaemic medications.
Cardiovascular disease (CVD) is the most prevalent cause of morbidity and mortality in diabetic patients. Improvement in cardiovascular complications with glycaemic control and managing cardiovascular risk factors is well established. However, the impact of hypoglycaemic medications on CVD is of increasing importance. In 2008, the U.S. Food and Drug Administration issued study regulations for hypoglycaemic agents after rosiglitazone was shown to increase the incidence of myocardial infarction, and the European Medicines Agency provided their own guidance in 2012. As a result, multiple studies have been published evaluating the cardiovascular safety of newer hypoglycaemic medications. Empagliflozin and liraglutide are among the newer agents that have shown cardiovascular benefit and are now recommended for patients with CVD or are at an increased risk of CVD per the 2017 American Diabetes Association Guidelines. Given the influx of new literature and other ongoing studies, it is important to understand the cardiovascular safety of newer hypoglycaemic medications. The purpose of this article is to provide a comprehensive review of clinical trials conducted evaluating cardiovascular outcomes of newer hypoglycaemic medications and their role within diabetic management. Key Messages With the prevalence of cardiovascular disease in diabetic patients, clinicians should develop a medication regimen that provides both sufficient efficacy for diabetes while also maintaining cardiovascular safety. Of the new diabetic classes, empagliflozin, a sodium-glucose co-transporter 2 inhibitor, and liraglutide, a glucagon-like peptide-1 receptor agonist, have shown cardiovascular benefit in diabetic patients with established cardiovascular disease and are now recommended in current guidelines for this population. Ongoing trials will give more insight to whether cardiovascular benefit is a class effect with sodium-glucose co-transporter 2 inhibitors and glucagon-like peptide-1 receptor agonists and the cardiovascular safety of dipeptidyl peptidase-4 inhibitors. Topics: Cardiovascular Diseases; Cardiovascular System; Diabetes Mellitus, Type 2; Glucagon-Like Peptide 1; Glucagon-Like Peptide-1 Receptor; Humans; Hypoglycemic Agents; Incidence; Practice Guidelines as Topic; Risk Factors; Sodium-Glucose Transporter 2; Sodium-Glucose Transporter 2 Inhibitors | 2017 |
The role of incretin hormones and glucagon in patients with liver disease.
Non-alcoholic fatty liver disease (NAFLD) is defined as hepatic steatosis exceeding 5% of hepatocytes with no other reason for hepatic fat accumulation. The association between NAFLD and type 2 diabetes is strong. Accordingly, up to 70% of obese patients with type 2 diabetes have NAFLD. The spectrum of NAFLD ranges from simple steatosis to non-alcoholic steatohepatitis with variable degrees of fibrosis and cirrhosis. Cirrhosis is the end-stage of chronic liver disease and is characterised by diffuse fibrosis and nodular regeneration of hepatocytes. Alcoholic liver disease and NAFLD are the most common aetiologies of cirrhosis. The WHO estimates that 70% of patients with cirrhosis have impaired glucose tolerance and 30% have manifest diabetes. The latter is termed hepatic diabetes and is associated with increased complications to cirrhosis and hepatocellular carcinoma. The objective of this thesis was to study the impact of liver dysfunction on incretin and glucagon (patho)physiology in relation to glucose metabolism. We hypothesised that NAFLD patients with normal glucose tolerance would develop reduced incretin effect and that NAFLD would worsen the incretin effect in patients with existing type 2 diabetes. Thus, in study I, we investigated the incretin effect and glucagon secretion in patients with NAFLD with and without type 2 diabetes compared to controls. We also hypothesised that the incretin effect would be disturbed in non-diabetic patients with more severe liver disease. Hence, the objective of study II was to investigate the incretin effect in patients with cirrhosis. Finally, the hypothesis in study III was that an impaired glucagonostatic effect of GLP-1 contributes to the hyperglucagonaemia of patients with liver disease. We therefore explored the glucagonostatic properties of GLP-1 in non-diabetic patients with NAFLD. The results of study I show that patients with NAFLD have normal secretion of GLP-1 and GIP and a reduced incretin effect. The groups with type 2 diabetes have the lowest incretion effect. We also find that NAFLD patients have high fasting glucagon concentrations regardless of their glucose (in)tolerance. We further demonstrated that patients with normal glucose tolerance and NAFLD have preserved glucagon suppression to both oral and intravenous glucose. In study II, we find that non-diabetic patients with cirrhosis have elevated concentrations of GLP-1 and GIP and a reduced incretin effect. Patients with cirrhosis also have f Topics: Animals; Blood Glucose; Diabetes Mellitus, Type 2; Glucagon; Glucagon-Like Peptide 1; Glucagon-Like Peptide-1 Receptor; Glucose Intolerance; Humans; Incretins; Insulin; Liver; Mice; Non-alcoholic Fatty Liver Disease | 2017 |
Interventions in type 2 diabetes mellitus and cardiovascular mortality-An overview of clinical trials.
Diabetes mellitus type 2 (T2DM) has been associated with an increased cardiovascular risk. Improving glycaemia or other traditional cardiovascular risk factors may reduce cardiovascular risk in patients with T2DM. However, single risk intervention in T2DM has not provided convincing evidence in the reduction of cardiovascular risk. The aim of this paper is to provide an overview of clinical trials involving reduction of cardiovascular outcomes in patients with T2DM. Trials with glucose lowering therapies have shown conflicting results. Intensive therapy to reduce glycaemia has shown some benefit on composite cardiovascular endpoints but these benefits take a longer period to emerge. Recent studies with empagliflozin and glucagon-like peptide-1 (GLP-1) agonists show promising results, but the mechanisms are most likely not mediated by improved glycaemia, given the relatively rapid effects. Both LDL-cholesterol and blood pressure reduction have been proven by large meta-analysis to reduce both cardiovascular events and mortality in all patients with T2DM. Treatment of microalbuminuria and anti-platelet therapy have only been proven in diabetic patients with increased cardiovascular risk. Classical lifestyle interventions have been disappointing with respect to cardiovascular outcome, possibly due to limited weight reduction. So far, the strongest evidence lies on bariatric surgery and a multifactorial intervention to reduce mortality and cardiovascular events in the long term. Topics: Benzhydryl Compounds; Blood Pressure; Cardiovascular Diseases; Cholesterol, LDL; Diabetes Mellitus, Type 2; Glucagon-Like Peptide 1; Glucosides; Humans; Hypoglycemic Agents; Life Style; Platelet Aggregation Inhibitors; Randomized Controlled Trials as Topic; Risk Factors | 2017 |
The Antidiabetic Mechanisms of Polyphenols Related to Increased Glucagon-Like Peptide-1 (GLP1) and Insulin Signaling.
Type-2 diabetes mellitus (T2DM) is an endocrine disease related to impaired/absent insulin signaling. Dietary habits can either promote or mitigate the onset and severity of T2DM. Diets rich in fruits and vegetables have been correlated with a decreased incidence of T2DM, apparently due to their high polyphenol content. Polyphenols are compounds of plant origin with several documented bioactivities related to health promotion. The present review describes the antidiabetic effects of polyphenols, specifically related to the secretion and effects of insulin and glucagon-like peptide 1 (GLP1), an enteric hormone that stimulates postprandial insulin secretion. The evidence suggests that polyphenols from various sources stimulate L-cells to secrete GLP1, increase its half-life by inhibiting dipeptidyl peptidase-4 (DPP4), stimulate β-cells to secrete insulin and stimulate the peripheral response to insulin, increasing the overall effects of the GLP1-insulin axis. The glucose-lowering potential of polyphenols has been evidenced in various acute and chronic models of healthy and diabetic organisms. Some polyphenols appear to exert their effects similarly to pharmaceutical antidiabetics; thus, rigorous clinical trials are needed to fully validate this claim. The broad diversity of polyphenols has not allowed for entirely describing their mechanisms of action, but the evidence advocates for their regular consumption. Topics: Animals; Diabetes Mellitus, Type 2; Glucagon-Like Peptide 1; Humans; Hypoglycemic Agents; Insulin; Insulin-Secreting Cells; Polyphenols; Signal Transduction | 2017 |
The safety of albiglutide for the treatment of type 2 diabetes.
Albiglutide is a marketed long acting GLP-1 receptor agonist (GLP-1 RA) administered by weekly injection. It has significantly less gastrointestinal side effects than other GLP-1 RAs in current use but does not improve HbA1c or promote weight loss to the same extent as competitor agents such as liraglutide. Area Covered: The safety of albiglutide is discussed. The review encompassed a search of PubMed and a thorough analysis of the European Union and US Food and Drug Administration approval documents. Expert Opinion: Unlike competitor agents, the gastrointestinal side effects of albiglutide are not much greater than placebo. It has been studied and appears safe at all stages of renal failure. There exists concern about an imbalance of pancreatitis cases in the approval program as well as injection site reactions which led to discontinuance of therapy in up to 2% of participants. A large long term study now underway will determine if albiglutide, with its relatively favorable GI tolerance, has a place in the treatment of patients with increased risk of cardiovascular events. Topics: Animals; Diabetes Mellitus, Type 2; Glucagon-Like Peptide 1; Glucagon-Like Peptide-1 Receptor; Glycated Hemoglobin; Humans; Hypoglycemic Agents; Injections; Weight Loss | 2017 |
[Effect of liraglutide in treatment of non-alcoholic fatty liver disease: mechanism of action and research advances].
Non-alcoholic fatty liver disease is a common chronic liver disease closely associated with obesity, hyperlipidemia, and diabetes. It can gradually progress to liver cirrhosis or even hepatocellular carcinoma; however, there are still no specific therapeutic agents for this disease. Liraglutide is a human glucagon-like peptide-1 analogue and has a marked effect in the treatment of type 2 diabetes. At present, many studies indicate that liraglutide also has a certain therapeutic effect on non-alcoholic fatty liver disease during the treatment of type 2 diabetes, but its mechanism of action remains unknown. This article reviews the known mechanisms of action of liraglutide in the treatment of non-alcoholic fatty liver disease.. 非酒精性脂肪性肝病是常见的慢性肝病,与肥胖、高脂血症、糖尿病等密切相关,可逐渐进展至肝硬化甚至肝细胞肝癌,然而目前尚无特效治疗药物。利拉鲁肽是人胰高血糖素样肽-1类似物,治疗2型糖尿病效果明确。目前很多研究结果显示利拉鲁肽在治疗2型糖尿病的同时对非酒精性脂肪性肝病有一定的治疗作用,但作用机制尚不明确。现就目前已经证实的利拉鲁肽对非酒精性脂肪性肝病的治疗作用机制进行综述。. Topics: Diabetes Mellitus, Type 2; Glucagon-Like Peptide 1; Humans; Hypoglycemic Agents; Liraglutide; Non-alcoholic Fatty Liver Disease; Obesity | 2017 |
Gut check on diabesity: leveraging gut mechanisms for the treatment of type 2 diabetes and obesity.
Gut hormones have long been understood to regulate food intake and metabolism. Bariatric surgery significantly elevates circulating gut hormone levels and is proven to affect acute remission of type 2 diabetes before any weight loss is observed. Subsequent weight loss is accrued over weeks to months but is sustained into the long term. Hence, there exists great enthusiasm to recapitulate these changes in gut hormones in the form of novel combination drugs for type 2 diabetes and obesity. Topics: Animals; Cholecystokinin; Diabetes Mellitus, Type 2; Gastric Inhibitory Polypeptide; Gastrointestinal Tract; Glucagon-Like Peptide 1; Humans; Obesity; Oxyntomodulin; Peptide YY | 2017 |
New Basal Insulins: a Clinical Perspective of Their Use in the Treatment of Type 2 Diabetes and Novel Treatment Options Beyond Basal Insulin.
The purpose of this review was to review advances in basal insulin formulations and new treatment options for patients with type 2 diabetes not achieving glycemic targets despite optimized basal insulin therapy.. Advances in basal insulin formulations have resulted in products with increasingly favorable pharmacokinetic and pharmacodynamic properties, including flatter, peakless action profiles, less inter- and intra-patient variability, and longer duration of activity. These properties have translated to significantly reduced risk of hypoglycemia (particularly during the night) compared with previous generation basal insulins. When optimized basal insulin therapy is not sufficient to obtain or maintain glycemic goals, various options exist to improve glycemic control, including intensification of insulin therapy with the addition of prandial insulin or changing to pre-mixed insulin and, more recently, the addition of a GLP-1 receptor agonist, either as a separate injection or as a component of one of the new fixed-ratio combinations of a basal insulin and GLP-1 RA. New safer and often more convenient basal insulins and fixed ratio combinations containing basal insulin (and GLP-1 receptor agonist) are available today for patients with type 2 diabetes not achieving glycemic goals. Head-to-head studies comparing the latest generation basal insulins are underway, and future studies assessing the fixed-ratio combinations will be important to better understand their differentiating features. Topics: Diabetes Mellitus, Type 2; Glucagon-Like Peptide 1; Glucagon-Like Peptide-1 Receptor; Humans; Hyperglycemia; Hypoglycemic Agents; Insulin | 2017 |
Cardiovascular Actions and Clinical Outcomes With Glucagon-Like Peptide-1 Receptor Agonists and Dipeptidyl Peptidase-4 Inhibitors.
Potentiation of glucagon-like peptide-1 (GLP-1) action through selective GLP-1 receptor (GLP-1R) agonism or by prevention of enzymatic degradation by inhibition of dipeptidyl peptidase-4 (DPP-4) promotes glycemic reduction for the treatment of type 2 diabetes mellitus by glucose-dependent control of insulin and glucagon secretion. GLP-1R agonists also decelerate gastric emptying, reduce body weight by reduction of food intake and lower circulating lipoproteins, inflammation, and systolic blood pressure. Preclinical studies demonstrate that both GLP-1R agonists and DPP-4 inhibitors exhibit cardioprotective actions in animal models of myocardial ischemia and ventricular dysfunction through incompletely characterized mechanisms. The results of cardiovascular outcome trials in human subjects with type 2 diabetes mellitus and increased cardiovascular risk have demonstrated a cardiovascular benefit (significant reduction in time to first major adverse cardiovascular event) with the GLP-1R agonists liraglutide (LEADER trial [Liraglutide Effect and Action in Diabetes: Evaluation of Cardiovascular Ourcome Results], -13%) and semaglutide (SUSTAIN-6 trial [Trial to Evaluate Cardiovascular and Other Long-term Outcomes with Semaglutide], -24%). In contrast, cardiovascular outcome trials examining the safety of the shorter-acting GLP-1R agonist lixisenatide (ELIXA trial [Evaluation of Lixisenatide in Acute Coronary Syndrom]) and the DPP-4 inhibitors saxagliptin (SAVOR-TIMI 53 trial [Saxagliptin Assessment of Vascular Outcomes Recorded in Patients With Diabetes Mellitus-Thrombolysis in Myocardial Infarction 53]), alogliptin (EXAMINE trial [Examination of Cardiovascular Outcomes With Alogliptin Versus Standard of Care in Patients With Type 2 Diabetes Mellitus and Acute Coronary Syndrome]), and sitagliptin (TECOS [Trial Evaluating Cardiovascular Outcomes With Sitagliptin]) found that these agents neither increased nor decreased cardiovascular events. Here we review the cardiovascular actions of GLP-1R agonists and DPP-4 inhibitors, with a focus on the translation of mechanisms derived from preclinical studies to complementary findings in clinical studies. We highlight areas of uncertainty requiring more careful scrutiny in ongoing basic science and clinical studies. As newer more potent GLP-1R agonists and coagonists are being developed for the treatment of type 2 diabetes mellitus, obesity, and nonalcoholic steatohepatitis, the delineation of the potential mechanisms tha Topics: Animals; Diabetes Mellitus, Type 2; Dipeptidyl-Peptidase IV Inhibitors; Glucagon-Like Peptide 1; Glucagon-Like Peptide-1 Receptor; Humans; Hypoglycemic Agents; Myocardial Ischemia; Risk Factors; Ventricular Dysfunction | 2017 |
GLP-1 and the kidney: from physiology to pharmacology and outcomes in diabetes.
The gastrointestinal tract - the largest endocrine network in human physiology - orchestrates signals from the external environment to maintain neural and hormonal control of homeostasis. Advances in understanding entero-endocrine cell biology in health and disease have important translational relevance. The gut-derived incretin hormone glucagon-like peptide 1 (GLP-1) is secreted upon meal ingestion and controls glucose metabolism by modulating pancreatic islet cell function, food intake and gastrointestinal motility, amongst other effects. The observation that the insulinotropic actions of GLP-1 are reduced in type 2 diabetes mellitus (T2DM) led to the development of incretin-based therapies - GLP-1 receptor agonists and dipeptidyl peptidase 4 (DPP-4) inhibitors - for the treatment of hyperglycaemia in these patients. Considerable interest exists in identifying effects of these drugs beyond glucose-lowering, possibly resulting in improved macrovascular and microvascular outcomes, including in diabetic kidney disease. As GLP-1 has been implicated as a mediator in the putative gut-renal axis (a rapid-acting feed-forward loop that regulates postprandial fluid and electrolyte homeostasis), direct actions on the kidney have been proposed. Here, we review the role of GLP-1 and the actions of associated therapies on glucose metabolism, the gut-renal axis, classical renal risk factors, and renal end points in randomized controlled trials of GLP-1 receptor agonists and DPP-4 inhibitors in patients with T2DM. Topics: Blood Glucose; Diabetes Mellitus, Type 2; Diabetic Nephropathies; Dipeptidyl-Peptidase IV Inhibitors; Glucagon-Like Peptide 1; Humans; Hyperglycemia; Hypoglycemic Agents; Incretins; Risk Factors | 2017 |
Predictors of response to glucagon-like peptide-1 receptor agonists: a meta-analysis and systematic review of randomized controlled trials.
The aim of the present meta-analysis is the identification of the characteristics of patients, which predict the efficacy on HbA1c of glucagon-like peptide-1 receptor agonists (GLP-1 RA).. A Medline and Embase search for "exenatide" OR "liraglutide" OR "albiglutide" OR "dulaglutide" OR "lixisenatide" was performed, collecting randomized clinical trials (duration > 12 weeks) up to September 2016, comparing GLP-1 RA at the maximal approved dose with placebo or active drugs. Furthermore, unpublished studies were searched in the www.clinicaltrials.gov register. For meta-analyses, the outcome considered were 24- and 52-week HbA1c. Separate analyses were performed, whenever possible, for subgroups of trials based on several inclusion criteria. In addition, meta-regression analyses were performed for comparisons for which 10 or more trails were available.. A total of 92 trials fulfilling the inclusion criteria were identified. In placebo-controlled trials (n = 41), the 24-week mean reduction of HbA1c with GLP-1 RA was - 0.75 [- 0.87; - 0.63]%. Shorter-acting molecules appear to be more effective in patients with lower fasting glucose, whereas longer-acting agents in patients with higher fasting hyperglycaemia. Obesity and duration of diabetes do not seem to moderate the efficacy of GLP-1 RA, whereas in non-Caucasians and older patients liraglutide could be less effective. At 52 weeks, only 9 placebo-controlled trials were available for preventing any reliable analyses.. Using a variety of approaches (meta-analyses of subgroup of trials, meta-regression, systematic review of subgroup analyses in individual trials, and meta-analyses of subgroups of patients), we identified some putative predictors of efficacy of GLP-1 RA, which deserve further investigation. Topics: Biomarkers, Pharmacological; Diabetes Mellitus, Type 2; Exenatide; Glucagon-Like Peptide 1; Glucagon-Like Peptide-1 Receptor; Glucagon-Like Peptides; Glycated Hemoglobin; Humans; Hypoglycemic Agents; Immunoglobulin Fc Fragments; Liraglutide; Peptides; Randomized Controlled Trials as Topic; Recombinant Fusion Proteins; Venoms | 2017 |
The Role of GLP-1 in the Metabolic Success of Bariatric Surgery.
Two of the most popular bariatric procedures, vertical sleeve gastrectomy (VSG) and Roux-en-Y gastric bypass (RYGB), are commonly considered metabolic surgeries because they are thought to affect metabolism in a weight loss-independent manner. In support of this classification, improvements in glucose homeostasis, insulin sensitivity, and even discontinuation of type 2 diabetes mellitus (T2DM) medication can occur before substantial postoperative weight loss. The mechanisms that underlie this effect are unknown. However, one of the common findings after VSG and RYGB in both animal models and humans is the sharp postprandial rise in several gut peptides, including the incretin and satiety peptide glucagonlike peptide-1 (GLP-1). The increase in endogenous GLP-1 signaling has been considered a primary pathway leading to postsurgical weight loss and improvements in glucose metabolism. However, the degree to which GLP-1 and other gut peptides are responsible for the metabolic successes after bariatric surgery is continually debated. In this review we discuss the mechanisms underlying the increase in GLP-1 and its potential role in the metabolic improvements after bariatric surgery, including remission of T2DM. Understanding the role of changes in gut peptides, or lack thereof, will be crucial in understanding the critical factors necessary for the metabolic success of bariatric surgery. Topics: Animals; Bariatric Surgery; Diabetes Mellitus, Type 2; Gastrectomy; Glucagon-Like Peptide 1; Humans; Incretins; Metabolism; Obesity; Postprandial Period | 2017 |
Glucagon-Like Peptide 1: A Predictor of Type 2 Diabetes?
The incretin effect is impaired in patients with type 2 diabetes.. To assess the relation between the incretin hormone GLP-1 and the prediabetic subtypes: impaired fasting glucose (IFG), impaired glucose tolerance (IGT), and the combined IFG/IGT to investigate whether a low GLP-1 response may be a predictor of prediabetes in adults.. 298 articles were found using a broad search phrase on the PubMed database and after the assessment of titles and abstracts 19 articles were included.. Studies assessing i-IFG/IFG and i-IGT/IGT found both increased, unaltered, and reduced GLP-1 levels. Studies assessing IFG/IGT found unaltered or reduced GLP-1 levels. When assessing the five studies with the largest sample size, it clearly suggests a decreased GLP-1 response in IFG/IGT subjects. Several other factors (BMI, glucagon, age, and nonesterified fatty acids (NEFA)), including medications (metformin), may also influence the secretion of GLP-1.. This review suggests that the GLP-1 response is a variable in prediabetes possibly due to a varying GLP-1-secreting profile during the development and progression of type 2 diabetes or difference in the measurement technique. Longitudinal prospective studies are needed to assess whether a reduced GLP-1 response is a predictor of diabetes. Topics: Biomarkers; Blood Glucose; Diabetes Mellitus, Type 2; Disease Progression; Glucagon-Like Peptide 1; Humans; Hypoglycemic Agents; Prediabetic State; Risk Factors | 2017 |
Genetic determinants of circulating GIP and GLP-1 concentrations.
The secretion of insulin and glucagon from the pancreas and the incretin hormones glucagon-like peptide-1 (GLP-1) and glucose-dependent insulinotropic peptide (GIP) from the gastrointestinal tract is essential for glucose homeostasis. Several novel treatment strategies for type 2 diabetes (T2D) mimic GLP-1 actions or inhibit incretin degradation (DPP4 inhibitors), but none is thus far aimed at increasing the secretion of endogenous incretins. In order to identify new potential therapeutic targets for treatment of T2D, we performed a meta-analysis of a GWAS and an exome-wide association study of circulating insulin, glucagon, GIP, and GLP-1 concentrations measured during an oral glucose tolerance test in up to 7,828 individuals. We identified 6 genome-wide significant functional loci associated with plasma incretin concentrations in or near the SLC5A1 (encoding SGLT1), GIPR, ABO, GLP2R, F13A1, and HOXD1 genes and studied the effect of these variants on mRNA expression in pancreatic islet and on metabolic phenotypes. Immunohistochemistry showed expression of GIPR, ABO, and HOXD1 in human enteroendocrine cells and expression of ABO in pancreatic islets, supporting a role in hormone secretion. This study thus provides candidate genes and insight into mechanisms by which secretion and breakdown of GIP and GLP-1 are regulated. Topics: ABO Blood-Group System; Aged; Aged, 80 and over; Diabetes Mellitus, Type 2; Dipeptidyl Peptidase 4; Enteroendocrine Cells; Female; Gastric Inhibitory Polypeptide; Gastrointestinal Hormones; Gastrointestinal Tract; Genetic Variation; Glucagon; Glucagon-Like Peptide 1; Glucagon-Like Peptide-2 Receptor; Glucose; Glucose Tolerance Test; Homeodomain Proteins; Humans; Incretins; Insulin; Insulin-Secreting Cells; Islets of Langerhans; Male; Middle Aged; Prospective Studies; Receptors, Gastrointestinal Hormone; RNA, Messenger; Sodium-Glucose Transporter 1 | 2017 |
Efficacy and safety of glucagon-like peptide-1 agonists on macrovascular and microvascular events in type 2 diabetes mellitus: A meta-analysis.
Glucagon-like peptide-1 (GLP-1) agonists improve glycaemic control in type 2 diabetes mellitus (DM). Outcome trials investigating macro and microvascular effects of GLP-1 agonists reported conflicting results. The aim of this study was to assess, in a meta-analysis, the effects of GLP-1 agonists on mortality, major nonfatal cardiovascular (CV) events, renal and retinal events.. MEDLINE, Cochrane, ISI Web of Science, SCOPUS and ClinicalTrial.gov databases were searched for articles published until June 2017. Randomized trials enrolling more than 200 patients, comparing GLP-1 versus placebo or active treatments in patients with DM, and assessing outcomes among all-cause death, CV death, MI, stroke, HF, diabetic retinopathy and nephropathy were included. 77 randomized trials enrolling 60,434 patients were included. Compared to control, treatment with GLP-1 significantly reduced the risk of all-cause death (RR: 0.888; CI: 0.804-0.979; p = 0.018) and the risk of CV death (RR: 0.858; CI: 0.757-0.973; p = 0.017). GLP-1 agonists did not affect the risk of MI (RR: 0.917; CI: 0.830-1.014; p = 0.092) as well as the risk of stroke (RR: 0.882; CI: 0.759-1.023; p = 0.097), HF (RR: 0.967; CI: 0.803-1.165; p = 0.725), retinopathy (RR: 1.000; CI: 0.807-1.238; p = 0.997) and nephropathy (RR: 0.866; CI: 0.625-1.199; p = 0.385).. Treatment with GLP-1 agonists in DM patients is associated with a significant reduction of all cause and CV mortality. Topics: Diabetes Mellitus, Type 2; Diabetic Angiopathies; Glucagon-Like Peptide 1; Humans; Hypoglycemic Agents; Incretins; Risk Assessment; Risk Factors; Signal Transduction; Treatment Outcome | 2017 |
Effect of Long-term Incretin-Based Therapies on Ischemic Heart Diseases in Patients with Type 2 Diabetes Mellitus: A Network Meta-analysis.
Patients with type 2 diabetes mellitus (T2DM) experience many cardiovascular complications. Several studies have demonstrated the cardioprotective effects of incretin-based therapies; however, there are few studies on the effects of long-term incretin-based therapies on cardiovascular events. Therefore, the present study conducted a systematic review and network meta-analysis to evaluate the effects of long-term incretin-based therapies on ischaemic diseases. We searched PubMed, CENTRAL, and Clinicaltrial.gov to retrieve randomised control trials reported until December 2016 and enrolled only RCTs with more than a 1-year follow-up. The network meta-analysis was performed using R Software with a GeMTC package. A total of 40 trials were included. Dipeptidyl peptidase 4 inhibitors and glucagon-like peptide-1 agonists were associated with a lower risk of myocardial infarction (MI) than were sulfonylureas (odds ratio [95% credible interval] 0.41 [0.24-0.71] and 0.48 [0.27-0.91], respectively). These results suggested that patients with T2DM receiving long-term incretin-based therapies have a lower risk of MI than do those receiving sulfonylurea-based therapy. These findings highlight the risks of cardiovascular events in patients who receive long-term incretin-based therapies, and may provide evidence for the selection of antidiabetic therapy in the future. Topics: Aged; Diabetes Mellitus, Type 2; Dipeptidyl-Peptidase IV Inhibitors; Female; Glucagon-Like Peptide 1; Humans; Hypoglycemic Agents; Incretins; Male; Middle Aged; Myocardial Ischemia; Publication Bias; Risk Factors; Time Factors | 2017 |
Glucagon-like peptide-1 mimetics, optimal for Asian type 2 diabetes patients with and without overweight/obesity: meta-analysis of randomized controlled trials.
Glucagon-like peptide-1 receptor agonists (GLP-1RAs) are desirable for diabetes, especially in patients with overweight/obesity. We aimed to determine whether GLP-1RAs exhibit different glucose-lowering efficacies between Asian type 2 diabetes (T2D) patients with and without overweight/obesity. Randomized controlled trials were searched in EMBASE, MEDLINE, CENTRAL, and ClinicalTrials.gov. Studies published in English with treatment duration ≥12 weeks and information on HbA1c changes were included. The studies were divided into normal body mass index (BMI) and overweight/obese groups according to baseline BMI. Among 3190 searched studies, 20 trials were included in the meta-analysis. The standardized mean differences in HbA1c change, fasting glucose change, and postprandial glucose change were equivalent between normal BMI and overweight/obese studies (p > 0.05). The relative risk of HbA1c < 6.5% target achievement in normal BMI trials (7.93; 95% confidence interval: 3.27, 19.20) was superior to that in overweight/obesity trials (2.23; 1.67, 2.97), with a significant difference (p = 0.020). Body weight loss (p = 0.572) and hypoglycemic risk(p = 0.920) were similar in the two groups. The glucose-lowering effects of GLP-1RAs were equivalent among Asian T2D patients. With their advantages for weight-loss or weight-maintenance, GLP-1RAs are optimal medicines for Asian T2D patients with and without overweight/obesity. Topics: Asian People; Blood Glucose; Body Weight; Diabetes Mellitus, Type 2; Glucagon-Like Peptide 1; Humans; Hypoglycemic Agents; Obesity; Overweight; Randomized Controlled Trials as Topic; Treatment Outcome; Weight Loss | 2017 |
Discovery, characterization, and clinical development of the glucagon-like peptides.
The discovery, characterization, and clinical development of glucagon-like-peptide-1 (GLP-1) spans more than 30 years and includes contributions from multiple investigators, science recognized by the 2017 Harrington Award Prize for Innovation in Medicine. Herein, we provide perspectives on the historical events and key experimental findings establishing the biology of GLP-1 as an insulin-stimulating glucoregulatory hormone. Important attributes of GLP-1 action and enteroendocrine science are reviewed, with emphasis on mechanistic advances and clinical proof-of-concept studies. The discovery that GLP-2 promotes mucosal growth in the intestine is described, and key findings from both preclinical studies and the GLP-2 clinical development program for short bowel syndrome (SBS) are reviewed. Finally, we summarize recent progress in GLP biology, highlighting emerging concepts and scientific insights with translational relevance. Topics: Animals; Diabetes Mellitus, Type 2; Drug Discovery; Glucagon-Like Peptide 1; Glucagon-Like Peptide 2; Glucagon-Like Peptide-1 Receptor; Humans; Short Bowel Syndrome; Structure-Activity Relationship | 2017 |
Pharmacogenetics of Glucagon-like Peptide-1 Agonists for the Treatment of Type 2 Diabetes Mellitus.
Pharmacogenetics is a promising area of medical research, providing methods to identify the appropriate pharmaceutical agent and dosing for each unique patient. Glucagon- like peptide-1 (GLP-1) agonists are a novel therapeutic choice used in the treatment of type 2 diabetes mellitus (T2DM), demonstrating efficacy regarding glycemic control and weight loss. Therapeutic response to GLP-1 agonist treatment is a complex biophenomenon, dependent on a plethora of modifiable (diet, exercise, adherence) and non-modifiable (genetic individual variants, ethnic characteristics) parameters. Ιn this context, it has been hypothesized that genetic polymorphisms of GLP-1 related genes may be associated with the therapeutic response to GLP-1 agonist treatment. This review focuses on the most important polymorphisms of the GLP-1 biological network that could affect clinical response to GLP-1 agonist treatment.. Biomedical databases were searched to identify key articles in the field and their results are critically presented in this review.. Recent pharmacological and clinical studies demonstrated a significant variation in GLP-1 agonist treatment, in cohorts with homogeneous adherence to diet, exercise and antidiabetic treatment. These studies identified several cases of non-responders to GLP-1 agonist therapy, in association with specific allelic patterns of GLP-1 receptor or other biomolecules implicated in glucose homeostasis.. Although the exact DNA sequences that cause the molecular changes leading to a variable response to GLP-1 agonists have not been yet fully identified, these findings underline the importance of an individualized approach in anti-diabetic treatment. Topics: Animals; Blood Glucose; Diabetes Mellitus, Type 2; Glucagon-Like Peptide 1; Glucagon-Like Peptide-1 Receptor; Humans; Hypoglycemic Agents; Pharmacogenetics; Polymorphism, Genetic; Weight Loss | 2017 |
Adverse Effects Associated With Newer Diabetes Therapies.
The increasing number of newer type 2 diabetes therapies has allowed providers an increased armamentarium for the optimal management of patients with diabetes. In fact, these newer agents have unique benefits in the management of type 2 diabetes. However, they are also associated with certain adverse effects. This review article aims to describe the notable adverse effects of these newer antidiabetic therapies including the glucagon-like peptide 1 receptor agonists, dipeptidyl peptidase-4 inhibitors, and the sodium-glucose cotransporter 2 inhibitors. The adverse effects reviewed herein include pancreatitis, medullary thyroid carcinoma, heart failure, gastrointestinal disturbances, renal impairment, and genitourinary infections. More clinical data are necessary to solidify the association of some of these adverse effects with the newer diabetes agents. However, it is important for health care practitioners to be well informed and prepared to properly monitor patients for these adverse effects. Topics: Diabetes Mellitus, Type 2; Dipeptidyl-Peptidase IV Inhibitors; Drug-Related Side Effects and Adverse Reactions; Gastrointestinal Diseases; Glucagon-Like Peptide 1; Glucagon-Like Peptide-1 Receptor; Humans; Hypoglycemic Agents; Kidney Diseases; Sodium-Glucose Transporter 2; Sodium-Glucose Transporter 2 Inhibitors | 2017 |
Clinical Pharmacokinetics and Pharmacodynamics of Saxagliptin, a Dipeptidyl Peptidase-4 Inhibitor.
Saxagliptin is an orally active, highly potent, selective and competitive dipeptidyl peptidase (DPP)-4 inhibitor used in the treatment of type 2 diabetes mellitus at doses of 2.5 or 5 mg once daily. DPP-4 is responsible for degrading the intestinally derived hormones glucagon-like peptide (GLP)-1 and glucose-dependent insulinotropic polypeptide (GIP). Inhibition of DPP-4 increases intact plasma GLP-1 and GIP concentrations, augmenting glucose-dependent insulin secretion. Both saxagliptin and its major active metabolite, 5-hydroxy saxagliptin, demonstrate high degrees of selectivity for DPP-4 compared with other DPP enzymes. Saxagliptin is orally absorbed and can be administered with or without food. The half-life of plasma DPP-4 inhibition with saxagliptin 5 mg is ~27 h, which supports a once-daily dosing regimen. Saxagliptin is metabolized by cytochrome P450 (CYP) 3A4/5 and is eliminated by a combination of renal and hepatic clearance. No clinically meaningful differences in saxagliptin or 5-hydroxy saxagliptin pharmacokinetics have been detected in patients with hepatic impairment. No clinically meaningful differences in saxagliptin or 5-hydroxy saxagliptin pharmacokinetics have been detected in patients with mild renal impairment, whereas dose reduction is recommended in patients with moderate or severe renal impairment because of greater systemic exposure [the area under the plasma concentration-time curve (AUC)] to saxagliptin total active moieties. Clinically relevant drug-drug interactions have not been detected; however, limiting the dose to 2.5 mg once daily is recommended in the USA when saxagliptin is coadministered with strong CYP inhibitors, because of increased saxagliptin exposure. In summary, saxagliptin has a predictable pharmacokinetic and pharmacodynamic profile. Topics: Adamantane; Area Under Curve; Cytochrome P-450 CYP3A; Diabetes Mellitus, Type 2; Dipeptides; Dipeptidyl-Peptidase IV Inhibitors; Dose-Response Relationship, Drug; Glucagon-Like Peptide 1; Half-Life; Humans; Hypoglycemic Agents; Metabolic Clearance Rate | 2017 |
Interplay between bone and incretin hormones: A review.
Bone is a tissue with multiple functions that is built from the molecular to anatomical levels to resist and adapt to mechanical strains. Among all the factors that might control the bone organization, a role for several gut hormones called "incretins" has been suspected. The present review summarizes the current evidences on the effects of glucose-dependent insulinotropic polypeptide (GIP) and glucagon-like peptide-1 (GLP-1) in bone physiology. Topics: Animals; Bone and Bones; Diabetes Mellitus, Type 1; Diabetes Mellitus, Type 2; Enteroendocrine Cells; Gastric Inhibitory Polypeptide; Glucagon-Like Peptide 1; Glucagon-Like Peptide-1 Receptor; Humans; Incretins; Osteoblasts; Osteoclasts; Receptors, Gastrointestinal Hormone; Stress, Mechanical | 2017 |
Harnessing glucagon-like peptide-1 receptor agonists for the pharmacological treatment of overweight and obesity.
Over the past 30 years, there has been a dramatic rise in global obesity prevalence, resulting in significant economic and social consequences. Attempts to develop pharmacological agents to treat obesity have met with many obstacles including the lack of long-term effectiveness and the potential for adverse effects. Historically, there have been limited treatment options for overweight and obesity; however, since 2012, a number of new drugs have become available. A number of peptides produced in the gut act as key mediators of the gut-brain axis, which is involved in appetite regulation. This review discusses the role of the gut-brain axis in appetite regulation with special focus on glucagon-like peptide-1. Liraglutide 3.0 mg, a glucagon-like peptide-1 receptor agonist that targets this pathway, is now approved for the treatment of obesity and overweight (body mass index ≥27 kg/m Topics: Appetite Regulation; Comorbidity; Diabetes Mellitus, Type 2; Glucagon-Like Peptide 1; Glucagon-Like Peptide-1 Receptor; Humans; Hypoglycemic Agents; Liraglutide; Obesity; Overweight; Randomized Controlled Trials as Topic; Weight Loss | 2017 |
Clinical relevance of the bile acid receptor TGR5 in metabolism.
The bile acid receptor TGR5 (also known as GPBAR1) is a promising target for the development of pharmacological interventions in metabolic diseases, including type 2 diabetes, obesity, and non-alcoholic steatohepatitis. TGR5 is expressed in many metabolically active tissues, but complex enterohepatic bile acid cycling limits the exposure of some of these tissues to the receptor ligand. Profound interspecies differences in the biology of bile acids and their receptors in different cells and tissues exist. Data from preclinical studies show promising effects of targeting TGR5 on outcomes such as weight loss, glucose metabolism, energy expenditure, and suppression of inflammation. However, clinical studies are scarce. We give a summary of key concepts in bile acid metabolism; outline different downstream effects of TGR5 activation; and review available data on TGR5 activation, with a focus on the translation of preclinical studies into clinically applicable findings. Studies in rodents suggest an important role for Tgr5 in Glp-1 secretion, insulin sensitivity, and energy expenditure. However, evidence of effects on these processes from human studies is less convincing. Ultimately, safe and selective human TGR5 agonists are needed to test the therapeutic potential of TGR5. Topics: Animals; Bile Acids and Salts; Diabetes Mellitus, Type 2; Energy Metabolism; Glucagon-Like Peptide 1; Glucose; Humans; Inflammation; Receptors, G-Protein-Coupled | 2017 |
Following the LEADER - why this and other recent trials signal a major paradigm shift in the management of type 2 diabetes.
The field of type 2 diabetes is undergoing a major transformation. Recent cardiovascular outcomes trials of glucose-lowering agents - including EMPA-REG, IRIS and LEADER, have all demonstrated convincing cardiovascular benefits within a relatively short period of time - all likely driven via non-glycemic effects of compounds under study. The implications of these studies (with primary focus on the LEADER trial) - and how their result may be paradigm shifting for type 2 diabetes management, are discussed in this article. Topics: Cardiotonic Agents; Cardiovascular Diseases; Clinical Trials as Topic; Diabetes Mellitus, Type 2; Diabetic Angiopathies; Diabetic Cardiomyopathies; Glucagon-Like Peptide 1; Humans; Hypoglycemic Agents; Hypolipidemic Agents; Precision Medicine; Risk Factors | 2017 |
Cardiovascular events and all-cause mortality associated with sulphonylureas compared with other antihyperglycaemic drugs: A Bayesian meta-analysis of survival data.
To conduct a systematic review and meta-analysis to determine the risk of cardiovascular events and all-cause mortality associated with sulphonylureas (SUs) vs other glucose lowering drugs in patients with T2DM (T2DM).. A systematic review of Medline, Embase, Cochrane and clinicaltrials.gov was conducted for studies comparing SUs with placebo or other antihyperglycaemic drugs in patients with T2DM. A cloglog model was used in the Bayesian framework to obtain comparative hazard ratios (HRs) for the different interventions. For the analysis of observational data, conventional fixed-effect pairwise meta-analyses were used.. The systematic review identified 82 randomized controlled trials (RCTs) and 26 observational studies. Meta-analyses of RCT data showed an increased risk of all-cause mortality and cardiovascular-related mortality for SUs compared with all other treatments combined (HR 1.26, 95% confidence interval [CI] 1.10-1.44 and HR 1.46, 95% CI 1.21-1.77, respectively). The risk of myocardial infarction was significantly higher for SUs compared with dipeptidyl peptidase-4 (DPP-4) inhibitors and sodium-glucose co-transporter-2 inhibitors (HR 2.54, 95% CI 1.14-6.57 and HR 41.80, 95% CI 1.64-360.4, respectively). The risk of stroke was significantly higher for SUs than for DPP-4 inhibitors, glucagon-like peptide-1 agonists, thiazolidinediones and insulin.. The present meta-analysis showed an association between SU therapy and a higher risk of major cardiovascular disease-related events compared with other glucose lowering drugs. Results of ongoing RCTs, which should be available in 2018, will provide definitive results on the risk of cardiovascular events and all-cause mortality associated with SUs vs other antihyperglycaemic drugs. Topics: Bayes Theorem; Cardiovascular Diseases; Cause of Death; Diabetes Mellitus, Type 2; Dipeptidyl-Peptidase IV Inhibitors; Glucagon-Like Peptide 1; Humans; Hypoglycemic Agents; Insulin; Mortality; Myocardial Infarction; Proportional Hazards Models; Sodium-Glucose Transporter 2 Inhibitors; Stroke; Sulfonylurea Compounds; Survival Rate; Thiazolidinediones | 2017 |
Glucagon-like Peptide-1 and the Central/Peripheral Nervous System: Crosstalk in Diabetes.
Glucagon-like peptide-1 (GLP-1) is released in response to meals and exerts important roles in the maintenance of normal glucose homeostasis. GLP-1 is also important in the regulation of neurologic and cognitive functions. These actions are mediated via neurons in the nucleus of the solitary tract that project to multiple regions expressing GLP-1 receptors (GLP-1Rs). Treatment with GLP-1R agonists (GLP-1-RAs) reduces ischemia-induced hyperactivity, oxidative stress, neuronal damage and apoptosis, cerebral infarct volume, and neurologic damage, after cerebral ischemia, in experimental models. Ongoing human trials report a neuroprotective effect of GLP-1-RAs in Alzheimer's and Parkinson's disease. In this review, we discuss the role of GLP-1 and GLP-1-RAs in the nervous system with focus on GLP-1 actions on appetite regulation, glucose homeostasis, and neuroprotection. Topics: Animals; Central Nervous System; Diabetes Mellitus; Diabetes Mellitus, Type 2; Glucagon-Like Peptide 1; Humans; Neurodegenerative Diseases; Peripheral Nervous System | 2017 |
Efficacy and safety of glucagon-like peptide-1 receptor agonists in type 2 diabetes: A systematic review and mixed-treatment comparison analysis.
To compare efficacy and safety of glucagon-like peptide-1 receptor agonists (GLP-1RAs) in people with type 2 diabetes.. We electronically searched, up to June 3, 2016, published randomized clinical trials lasting between 24 and 32 weeks that compared a GLP-1RA (albiglutide, dulaglutide, twice-daily exenatide and once-weekly exenatide, liraglutide, lixisenatide, semaglutide and taspoglutide) with placebo or another GLP-1RA. Data on cardiometabolic and safety outcomes were analysed using a mixed-treatment comparison meta-analysis.. A total of 34 trials (14 464 participants) met the inclusion criteria; no published data for semaglutide were available. Compared with placebo, all GLP-1RAs reduced glycated haemoglobin (HbA1c) and fasting plasma glucose (FPG) levels (reductions ranged from -0.55% and -0.73 mmol/L, respectively, for lixisenatide to -1.21% and -1.97 mmol/L, respectively, for dulaglutide). There were no differences within short-acting (twice-daily exenatide and lixisenatide) or long-acting (albiglutide, dulaglutide, once-weekly exenatide, liraglutide and taspoglutide) groups. Compared with twice-daily exenatide, dulaglutide treatment was associated with the greatest HbA1c and FPG reduction (0.51% and 1.04 mmol/L, respectively), followed by liraglutide (0.45% and 0.93 mmol/L, respectively) and once-weekly exenatide (0.38% and 0.85 mmol/L, respectively); similar reductions were found when these 3 agents were compared with lixisenatide. Compared with placebo, all GLP-1RAs except albiglutide reduced weight and increased the risk of hypoglycaemia and gastrointestinal side effects, and all agents except dulaglutide and taspoglutide reduced systolic blood pressure. When all GLP-1RAs were compared with each other, no clinically meaningful differences were observed in weight loss, blood pressure reduction or hypoglycaemia risk. Albiglutide had the lowest risk of nausea and diarrhoea and once-weekly exenatide the lowest risk of vomiting.. The RCTs in the present analysis show that all GLP-1RAs improve glycaemic control, reduce body weight and increase the risk of adverse gastrointestinal symptoms compared with placebo. Although there were no differences when short-acting agents were compared with each other or when long-acting agents were compared with each other, dulaglutide, liraglutide and once-weekly exenatide were superior to twice-daily exenatide and lixisenatide at lowering HbA1c and FPG levels. There were no differences in hypoglycaemia between these 3 agents, whilst once-weekly exenatide had the lowest risk of vomiting. These results, along with patient's preferences and individualized targets, should be considered when selecting a GLP-1RA. Topics: Blood Glucose; Diabetes Mellitus, Type 2; Drug Administration Schedule; Exenatide; Female; Glucagon-Like Peptide 1; Glucagon-Like Peptide-1 Receptor; Glucagon-Like Peptides; Glycated Hemoglobin; Humans; Hypoglycemia; Hypoglycemic Agents; Immunoglobulin Fc Fragments; Incretins; Liraglutide; Male; Middle Aged; Peptides; Randomized Controlled Trials as Topic; Recombinant Fusion Proteins; Treatment Outcome; Venoms | 2017 |
Physiological and pathophysiological aspects of incretin hormones and glucagon.
Infusion of oxyntomodulin and the separate and combined infusion of GLP-1 and glucagon inhibited food intake similarly in healthy individuals, with no superior effect of combining GLP-1 and glucagon. We confirm the inhibitory effects of oxyntomodulin and GLP-1, respectively, on GE and appetite scores observed previously, but by adding glucagon to the infusion of GLP-1 we found no additive effects. Unexpectedly, glucagon alone had no effect on GE and appetite scores, but inhibited food intake to the same extent as oxyntomodulin, GLP-1 and GLP-1 + glucagon. Both the GLP-1, oxyntomodulin and GLP-1 + glucagon infusions appeared to increase O Topics: Animals; Appetite; Diabetes Mellitus, Type 2; Enteroendocrine Cells; Gastric Inhibitory Polypeptide; Glucagon; Glucagon-Like Peptide 1; Humans; Incretins; Insulin; Oxyntomodulin; Peptide Fragments | 2017 |
Clinical Pharmacokinetics and Pharmacodynamics of Albiglutide.
Albiglutide is a long-acting, glucagon-like peptide-1 receptor agonist for subcutaneous administration with a recommended dose of 30-50 mg once weekly. The aim of this article is to outline the pharmacokinetic and pharmacodynamic properties of albiglutide including the clinical efficacy and safety data underlying the approval of albiglutide for the treatment of type 2 diabetes mellitus in both Europe and USA. Albiglutide is cleared from the circulation (by a mechanism partially dependent on renal function) with an elimination half-life of 5 days, allowing once-weekly administration. In the clinical trial program called HARMONY, albiglutide demonstrated placebo-corrected reductions in glycosylated hemoglobin of 0.8-1.0%. In addition, reductions in fasting plasma glucose in the range of 1.3-2.4 mmol/L compared with placebo were reported. Albiglutide caused weight reductions at a level comparable to placebo in the HARMONY trials, possibly related to limited central nervous system penetration of the large albiglutide molecule. Albiglutide demonstrated a generally favorable safety profile, although with a signal of an increased risk of pancreatitis. The well-known adverse events related to glucagon-like peptide-1 receptor activation such as nausea, diarrhea, and vomiting were less frequent with albiglutide compared with another glucagon-like peptide-1 receptor agonist, liraglutide, but slightly more frequent following treatment with albiglutide than with placebo or active comparators from other classes of anti-hyperglycemic drugs. The full risk-benefit profile for albiglutide used in treating type 2 diabetes will not be clear until reporting of the long-term cardiovascular outcome trial (HARMONY Outcome) with planned completion in 2019. Topics: Animals; Diabetes Mellitus, Type 2; Glucagon-Like Peptide 1; Humans; Hypoglycemic Agents; Recombinant Proteins; Treatment Outcome | 2017 |
Mechanisms of Action of Surgical Interventions on Weight-Related Diseases: the Potential Role of Bile Acids.
Surgical interventions for weight-related diseases (SWRD) may have substantial and sustainable effect on weight reduction, also leading to a higher remission rate of type 2 diabetes (T2D) mellitus than any other medical treatment or lifestyle intervention. The resolution of T2D after Roux-en-Y gastric bypass (RYGB) typically occurs too quickly to be accounted for by weight loss alone, suggesting that these operations have a direct impact on glucose homeostasis. The mechanisms underlying these beneficial effects however remain unclear. Recent research suggests that changes in the concentrations of plasma bile acids might contribute to these metabolic changes after surgery. In this review, we aimed to outline the potential role of bile acids in SWRD. We systematically reviewed MEDLINE, SCOPUS, and Web of Science for articles reporting the effect of SWRD on outcomes published between 1969 and 2016. We found that changes in circulating bile acids after surgery may play a major role through activation of the farnesoid X receptor A (FXRA), the fibroblast growth factor 19 (FGF19), and the G protein-coupled bile acid receptor (TGR5). Bile acid concentration increased significantly after RYGB. Some studies suggest that a transitory decrease occurs at 1 week post-surgery, followed by a gradual increase. Most studies have shown the increase to be proportionate by all bile acid subtypes. Bile acids can regulate glucose metabolism through the expression of TGR5 receptor in L cells, resulting in a release of glucagon-like peptide 1 (GLP-1). It may also induce the synthesis and secretion of FGF19 in ileal cells, thereby improving insulin sensitivity and regulating glucose metabolism. All the present SWRD are involved with changes in food stimulation to the stomach. This implies that discovering and developing the antagonists to TGR5 and FXRA may effectively control metabolic syndrome and the elucidation of the mechanisms underlying the physiological effects related to weight loss and T2D remission after surgery may help to identify new drug targets. Topics: Bile Acids and Salts; Diabetes Mellitus, Type 2; Fibroblast Growth Factors; Gastric Bypass; Glucagon-Like Peptide 1; Humans; Insulin Resistance; Obesity, Morbid | 2017 |
Comparisons of weight changes between sodium-glucose cotransporter 2 inhibitors treatment and glucagon-like peptide-1 analogs treatment in type 2 diabetes patients: A meta-analysis.
To evaluate the efficacy of weight changes from baseline of the sodium-glucose cotransporter 2 (SGLT2) inhibitors treatment and glucagon-like peptide-1 (GLP-1) analogs treatment after comparisons with a placebo in type 2 diabetes patients, and the associated factors.. Studies were searched from when recording began, June 2004, until June 2015, and re-searched in July 2016, and placebo-controlled randomized trials in type 2 diabetes patients with a study length of ≥12 weeks were included.. A total of 97 randomized controlled trials were included. Compared with a placebo, treatment with SGLT2 inhibitors was associated with a significantly greater decrease in weight change from baseline (weighted mean differences -2.01 kg, 95% confidence interval -2.18 to -1.83 kg, P < 0.001). Compared with a placebo, changes with GLP -1 treatment were also associated with a comparable decrease in weight change from baseline (weighted mean differences -1.59 kg, 95% confidence interval -1.86 to -1.32 kg, P < 0.001). Meta-regression analysis showed that the baseline age, sex, baseline glycated hemoglobin, diabetes duration or baseline body mass index were not associated with the weight change from baseline in SGLT2 inhibitors or in GLP-1 treatment corrected by placebo. Comparisons of weight changes from baseline corrected by placebo between SGLT2 inhibitors and GLP-1 treatment showed that the difference was not significant (P > 0.05).. According to the present meta-analysis, treatment with SGLT2 inhibitors and treatment with GLP-1 analogs led to comparable weight changes from baseline, which are both with significance when compared with placebo treatment. Topics: Diabetes Mellitus, Type 2; Glucagon-Like Peptide 1; Humans; Hypoglycemic Agents; Sodium-Glucose Transporter 2; Sodium-Glucose Transporter 2 Inhibitors; Weight Loss | 2017 |
Rationale for treatment options for mealtime glucose control in patients with type 2 diabetes.
While glycemic control is routinely assessed using HbA1c and fasting glucose measures, postprandial glucose (PPG) is also an important contributor of overall glycemia. Furthermore, PPG excursions have been linked to complications of diabetes. This review examines the effects of glucose-lowering therapies (including treatments administered at mealtime) on postprandial hyperglycemia in patients with type 2 diabetes. A PubMed search was conducted to identify clinical studies of treatments for mealtime glucose control in type 2 diabetes. Different treatments may have comparable effects on HbA1c but varying effects on PPG control and glucose fluctuations. Older classes of oral glucose-lowering treatments administered at mealtime to lower PPG include meglitinides and α-glucosidase inhibitors. Injectable therapies, including prandial insulin analogs, glucagon-like peptide-1 receptor agonists (GLP-1RAs), and the amylin analog pramlintide, all effectively target postprandial hyperglycemia. Compared with longer-acting GLP-1RAs, short-acting GLP-1RAs, such as exenatide twice daily and lixisenatide once daily, have a greater effect on PPG control, which is primarily mediated by a more pronounced effect on delayed gastric emptying. Dipeptidyl peptidase-4 inhibitors and sodium-glucose cotransporter 2 inhibitors also reduce postprandial hyperglycemia. To achieve more physiologically normal glycemic control, choice of therapy should ideally aim to address daily glucose fluctuations, including hyperglycemic peaks and hypoglycemic troughs, and long-term glycemic control. Topics: Blood Glucose; Diabetes Mellitus, Type 2; Dipeptidyl-Peptidase IV Inhibitors; Drug Administration Schedule; Glucagon-Like Peptide 1; Glycated Hemoglobin; Humans; Hypoglycemic Agents; Insulin; Postprandial Period; Sodium-Glucose Transporter 2 Inhibitors | 2017 |
Lixisenatide: A New Daily GLP-1 Agonist for Type 2 Diabetes Management.
To review the pharmacology, pharmacokinetics, efficacy, and safety of the glucagon-like peptide-1 receptor agonist (GLP-1RA), lixisenatide, in the treatment of type 2 diabetes mellitus.. A PubMed (1966-2016) search was conducted using the following keywords: lixisenatide, AVE0010, glucagon-like peptide-1 agonist, and type 2 diabetes. References were reviewed to identify additional sources.. Articles written in English were included if they evaluated the pharmacology, pharmacokinetics, efficacy, or safety of lixisenatide in human subjects.. Lixisenatide lowers blood glucose through a glucose-dependent increase in insulin release from pancreatic β-cells and a decreased release of glucagon from pancreatic α-cells. Additionally, lixisenatide delays gastric emptying and increases satiety. Lixisenatide has been studied head to head against exenatide and insulin glulisine. It has also been studied as monotherapy and in combination with metformin, sulfonylureas, pioglitazone, and insulin glargine. In the GetGoal clinical trial series, lixisenatide resulted in a hemoglobin A. Lixisenatide provides an additional GLP-1RA option, which may have more postprandial blood glucose-lowering effects than the other agents in the class because of its shorter half-life and effects on delaying gastric emptying. Topics: Blood Glucose; Clinical Trials as Topic; Diabetes Mellitus, Type 2; Drug Administration Schedule; Drug Interactions; Drug Therapy, Combination; Glucagon-Like Peptide 1; Glucagon-Like Peptide-1 Receptor; Glycated Hemoglobin; Half-Life; Humans; Hypoglycemic Agents; Peptides; Treatment Outcome | 2017 |
Improving drug-like properties of insulin and GLP-1 via molecule design and formulation and improving diabetes management with device & drug delivery.
There is an increased incidence of diabetes worldwide. The discovery of insulin revolutionized the management of diabetes, the revelation of glucagon-like peptide-1 (GLP-1) and introduction of GLP-1 receptor agonists to clinical practice was another breakthrough. Continued translational research resulted in better understanding of diabetes, which, in combination with cutting-edge biology, chemistry, and pharmaceutical tools, have allowed for the development of safer, more effective and convenient insulins and GLP-1. Advances in self-administration of insulin and GLP-1 receptor agonist therapies with use of drug-device combination products have further improved the outcomes of diabetes management and quality of life for diabetic patients. The synergies of insulin and GLP-1 receptor agonist actions have led to development of devices that can deliver both molecules simultaneously. New chimeric GLP-1-incretins and insulin-GLP-1-incretin molecules are also being developed. The objective of this review is to summarize molecular designs to improve the drug-like properties of insulin and GLP-1 and to highlight the continued advancement of drug-device combination products to improve diabetes management. Topics: Animals; Diabetes Mellitus, Type 2; Drug Compounding; Drug Delivery Systems; Drug Design; Glucagon-Like Peptide 1; Humans; Hypoglycemic Agents; Insulin | 2017 |
Basal Glucose Can Be Controlled, but the Prandial Problem Persists-It's the Next Target!
Both basal and postprandial elevations contribute to the hyperglycemic exposure of diabetes, but current therapies are mainly effective in controlling the basal component. Inability to control postprandial hyperglycemia limits success in maintaining overall glycemic control beyond the first 5 to 10 years after diagnosis, and it is also related to the weight gain that is common during insulin therapy. The "prandial problem"-comprising abnormalities of glucose and other metabolites, weight gain, and risk of hypoglycemia-deserves more attention. Several approaches to prandial abnormalities have recently been studied, but the patient populations for which they are best suited and the best ways of using them remain incompletely defined. Encouragingly, several proof-of-concept studies suggest that short-acting glucagon-like peptide 1 agonists or the amylin agonist pramlintide can be very effective in controlling postprandial hyperglycemia in type 2 diabetes in specific settings. This article reviews these topics and proposes that a greater proportion of available resources be directed to basic and clinical research on the prandial problem. Topics: Blood Glucose; Diabetes Mellitus, Type 2; Glucagon-Like Peptide 1; Glycoside Hydrolase Inhibitors; Humans; Hyperglycemia; Hypoglycemic Agents; Insulin; Islet Amyloid Polypeptide; Postprandial Period; Randomized Controlled Trials as Topic | 2017 |
Incretin-based agents in type 2 diabetic patients at cardiovascular risk: compare the effect of GLP-1 agonists and DPP-4 inhibitors on cardiovascular and pancreatic outcomes.
Incretin-based agents, including dipeptidyl peptidase-4 inhibitors (DPP-4Is) and glucagon-like peptide-1 agonists (GLP-1As), work via GLP-1 receptor for hyperglycemic control directly or indirectly, but have different effect on cardiovascular (CV) outcomes. The present study is to evaluate and compare effects of incretin-based agents on CV and pancreatic outcomes in patients with type 2 diabetes mellitus (T2DM) and high CV risk.. Six prospective randomized controlled trials (EXMAINE, SAVOR-TIMI53, TECOS, ELIXA, LEADER and SUSTAIN-6), which included three trials for DPP-4Is and three trials for GLP-1As, with 55,248 participants were selected to assess the effect of different categories of incretin-based agents on death, CV outcomes (CV mortality, major adverse CV events, nonfatal myocardial infarction, nonfatal stroke, heart failure hospitalization), pancreatic events (acute pancreatitis and pancreatic cancer) as well as on hypoglycemia.. When we evaluated the combined effect of six trials, the results suggested that incretin-based treatment had no significant effect on overall risks of CV and pancreatic outcomes compared with placebo. However, GLP-1As reduced all-cause death (RR = 0.90, 95% CI 0.82-0.98) and CV mortality (RR = 0.84, 95% CI 0.73-0.97), whereas DPP-4Is had no significant effect on CV outcomes but elevated the risk for acute pancreatitis (OR = 1.76, 95% CI 1.14-2.72) and hypoglycemia (both any and severe hypoglycemia), while GLP-1As lowered the risk of severe hypoglycemia.. GLP-1As decreased risks of all-cause and CV mortality and severe hypoglycemia, whereas DPP-4Is had no effect on CV outcomes but increased risks in acute pancreatitis and hypoglycemia. Topics: Cardiovascular Diseases; Diabetes Mellitus, Type 2; Dipeptidyl-Peptidase IV Inhibitors; Glucagon-Like Peptide 1; Humans; Hypoglycemia; Hypoglycemic Agents; Incretins; Pancreatitis; Randomized Controlled Trials as Topic; Risk Factors; Treatment Outcome | 2017 |
Intensifying Treatment Beyond Monotherapy in Type 2 Diabetes Mellitus: Where Do Newer Therapies Fit?
Guidelines for a standard second diabetes medication for the treatment of type 2 diabetes (T2DM) have yet to be established. The rapid increase in the number of newer therapies available makes the choice more difficult. Thus, we reviewed clinical trial evidence evaluating newer therapies available for treatment intensification beyond monotherapy.. Head-to-head studies comparing newer therapies versus traditional (i.e., sulfonylurea) approaches consistently find lower incidence of hypoglycemia and weight gain with newer therapies. Glucagon-like peptide-1 (GLP-1) receptor agonists and sodium-glucose co-transporter 2 (SGLT2) inhibitors demonstrate high glycemic efficacy, while merits of dipeptidyl peptidase-4 (DPP-4) inhibitors include their tolerability. Secondary effects (weight loss, cardiovascular outcomes, renal function) are of growing interest with newer therapies. Choices for treatment intensification in T2DM diabetes are numerous. Understanding the comparative evidence of newer treatment choices, as provided in this review, may help guide clinical decision making. Topics: Diabetes Mellitus, Type 2; Dipeptidyl-Peptidase IV Inhibitors; Glucagon-Like Peptide 1; Glucagon-Like Peptide-1 Receptor; Humans; Hypoglycemic Agents; Sodium-Glucose Transporter 2; Sodium-Glucose Transporter 2 Inhibitors; Sulfonylurea Compounds | 2017 |
Dulaglutide for the treatment of type 2 diabetes.
Glucagon-like peptide-1 receptor agonists (GLP-1 RAs) are injectable agents used for the treatment of hyperglycemia in type 2 diabetes. The interest for this pharmacological class is rising with the development of once weekly compounds and the demonstration of a potential reduction in cardiorenal outcomes. Areas covered: The paper describes the main pharmacokinetic/pharmacodynamic characteristics of dulaglutide, a new once-weekly GLP-1 RA. Dulaglutide was extensively investigated in the phase-3 AWARD program, which demonstrated its safety and efficacy when compared to placebo or active glucose-lowering agents in patients treated with diet alone, metformin or sulfonylurea monotherapy, oral dual therapies and basal insulin. In both Caucasian and Japanese patients, comparative trials showed better glucose control with dulaglutide, with a minimal risk of hypoglycemia and weight loss, but at the expense of an increased dropout rate due to side effects, mostly transient gastrointestinal disturbances. Dulaglutide proved its non-inferiority versus liraglutide and the safety and tolerance profile is similar to that of other GLP-1 RAs. Expert opinion: The once-weekly formulation and the combined positive effects on both glucose control and weight improves patient satisfaction despite nausea. Dulaglutide must prove its capacity to reduce cardiovascular and diabetic complications in the ongoing prospective REWIND trial. Topics: Animals; Diabetes Mellitus, Type 2; Drug Administration Schedule; Drug Therapy, Combination; Glucagon-Like Peptide 1; Glucagon-Like Peptide-1 Receptor; Glucagon-Like Peptides; Humans; Hyperglycemia; Hypoglycemia; Hypoglycemic Agents; Immunoglobulin Fc Fragments; Insulin; Prospective Studies; Recombinant Fusion Proteins; Treatment Outcome | 2017 |
The cardiovascular safety trials of DPP-4 inhibitors, GLP-1 agonists, and SGLT2 inhibitors.
In this paper, we review the results of large, double-blind, placebo-controlled randomized trials mandated by the US Food and Drug Administration to examine the cardiovascular safety of newly-approved antihyperglycemic agents in patients with type 2 diabetes. The cardiovascular effects of dipeptidyl peptidase-4 (DPP-4) inhibitors remain controversial: while these drugs did not reduce or increase the risk of primary, pre-specified composite cardiovascular outcomes, one DPP-4 inhibitor (saxagliptin) increased the risk of hospitalization for heart failure in the overall population; another (alogliptin) demonstrated inconsistent effects on heart failure hospitalization across subgroups of patients, and a third (sitagliptin) demonstrated no effect on heart failure. Evidence for cardiovascular benefits of glucagon-like peptide-1 (GLP-1) agonists has been similarly heterogeneous, with liraglutide and semaglutide reducing the risk of composite cardiovascular outcomes, but lixisenatide having no reduction or increase in cardiovascular risk. The effect of GLP-1 agonists on retinopathy remains a potential concern. In the only completed trial to date to assess a sodium-glucose cotransporter-2 (SGLT2) inhibitor, empagliflozin reduced the risk of composite cardiovascular endpoints, predominantly through its impact on cardiovascular mortality and heart failure hospitalization. Topics: Biomarkers; Blood Glucose; Cardiovascular Diseases; Diabetes Mellitus, Type 2; Dipeptidyl Peptidase 4; Dipeptidyl-Peptidase IV Inhibitors; Glucagon-Like Peptide 1; Humans; Incretins; Randomized Controlled Trials as Topic; Risk Assessment; Risk Factors; Sodium-Glucose Transporter 2; Sodium-Glucose Transporter 2 Inhibitors; Treatment Outcome | 2017 |
Evidence connecting old, new and neglected glucose-lowering drugs to bile acid-induced GLP-1 secretion: A review.
Bile acids are amphipathic water-soluble steroid-based molecules best known for their important lipid-solubilizing role in the assimilation of fat. Recently, bile acids have emerged as metabolic integrators with glucose-lowering potential. Among a variety of gluco-metabolic effects, bile acids have been demonstrated to modulate the secretion of the gut-derived incretin hormone glucagon-like peptide-1 (GLP-1), possibly via the transmembrane receptor Takeda G-protein-coupled receptor 5 and the nuclear farnesoid X receptor, in intestinal L cells. The present article critically reviews current evidence connecting established glucose-lowering drugs to bile acid-induced GLP-1 secretion, and discusses whether bile acid-induced GLP-1 secretion may constitute a new basis for understanding how metformin, inhibitors of the apical sodium-dependent bile acids transporter, and bile acid sequestrants - old, new and neglected glucose-lowering drugs - improve glucose metabolism. Topics: Animals; Bile Acids and Salts; Diabetes Mellitus, Type 2; Enteroendocrine Cells; Evidence-Based Medicine; Gastrointestinal Agents; Glucagon-Like Peptide 1; Humans; Hyperglycemia; Hypoglycemia; Hypoglycemic Agents; Models, Biological | 2017 |
Incretins.
Glucose-dependent insulinotropic polypeptide (GIP) and glucagon-like peptide-1 (GLP-1) are the known incretin hormones in humans, released predominantly from the enteroendocrine K and L cells within the gut. Their secretion is regulated by a complex of integrated mechanisms involving direct contact for the activation of different chemo-sensors on the brush boarder of K and L cells and several indirect neuro-immuno-hormonal loops. The biological actions of GIP and GLP-1 are fundamental determinants of islet function and blood glucose homeostasis in health and type 2 diabetes. Moreover, there is increasing recognition that GIP and GLP-1 also exert pleiotropic extra-glycaemic actions, which may represent therapeutic targets for human diseases. In this review, we summarise current knowledge of the biology of incretin hormones in health and metabolic disorders and highlight the therapeutic potential of incretin hormones in metabolic regulation. Topics: Adipose Tissue; Animals; Diabetes Mellitus, Type 2; Glucagon-Like Peptide 1; Humans; Incretins; Liver; Obesity | 2016 |
Does Glucagon-like Peptide-1 Ameliorate Oxidative Stress in Diabetes? Evidence Based on Experimental and Clinical Studies.
Glucagon-like peptide-1 (GLP-1) has shown to influence the oxidative stress status in a number of in vitro, in vivo and clinical studies. Well-known effects of GLP-1 including better glycemic control, decreased food intake, increased insulin release and increased insulin sensitivity may indirectly contribute to this phenomenon, but glucose-independent effects on ROS level, production and antioxidant capacity have been suggested to also play a role. The potential 'antioxidant' activity of GLP-1 along with other proposed glucose-independent modes of action related to ameliorating redox imbalance remains a controversial topic but could hold a therapeutic potential against micro- and macrovascular diabetic complications. This review discusses the presently available knowledge from experimental and clinical studies on the effects of GLP-1 on oxidative stress in diabetes and diabetes-related complications. Topics: Animals; Diabetes Mellitus, Type 2; Drug Evaluation, Preclinical; Evidence-Based Practice; Exenatide; Glucagon-Like Peptide 1; Humans; Oxidative Stress; Peptides; Reactive Oxygen Species; Venoms | 2016 |
The value of short- and long-acting glucagon-like peptide-1 agonists in the management of type 2 diabetes mellitus: experience with exenatide.
Only about half of patients with type 2 diabetes treated with antihyperglycemic drugs achieve glycemic control (HbA1c <7%), most commonly due to poor treatment adherence. Glucagon-like peptide-1 (GLP-1) receptor agonists act on multiple targets involved in glucose homeostasis and have a low risk of causing hypoglycemia. While GLP-1 receptor (GLP-1R) agonists share the same mechanism of action, clinical profiles of individual agents differ, particularly between short- and long-acting agents. In this article, recent findings regarding the pharmacology of GLP-1 agonists are reviewed, and the clinical effects of short- versus long-acting agents are compared.. Relevant articles were identified through a search of PubMed using the keywords glucagon-like peptide-1, GLP-1, glucagon-like peptide-1 receptor agonist, GLP-1R agonist, and exenatide for publications up to 22 May 2015. Supporting data were obtained from additional searches for albiglutide, dulaglutide, liraglutide and lixisenatide as well as from the bibliographies of key articles.. Short-acting GLP-1R agonists produce greater reductions in postprandial glucose levels by slowing gastric emptying, whereas long-acting GLP-1R agonists produce greater reductions in fasting blood glucose by stimulating insulin secretion from the pancreas. These characteristics can be exploited to provide individualized treatment to patients. A large body of evidence supports the benefits of short- and long-acting exenatide as add-on therapy in patients with inadequate glycemic control despite maximum tolerated doses of metformin and/or sulfonylurea. Exenatide is generally well tolerated and no new safety concerns were identified during long-term follow-up of up to 5 years. A limitation of this review of short-and long-acting GLP-1 receptor agonists is that it focuses on exenatide rather than all the drugs in this class. However, the focus on a single molecule helps to avoid any confusion that may be introduced as a result of differences in molecular structure and size.. Short-acting GLP-1R agonists including exenatide are well suited to patients with type 2 diabetes with exaggerated postprandial glucose excursions and for co-administration with basal insulin therapy. Long-acting GLP-1R agonists including once weekly exenatide offer greater convenience and are well suited to patients who require specific control of fasting hyperglycemia. Topics: Diabetes Mellitus, Type 2; Exenatide; Gastric Emptying; Glucagon-Like Peptide 1; Glucagon-Like Peptide Receptors; Glycated Hemoglobin; Humans; Hypoglycemic Agents; Insulin; Insulin Secretion; Peptides; Venoms | 2016 |
Incretin actions and consequences of incretin-based therapies: lessons from complementary animal models.
The two incretin hormones, glucose-dependent insulinotropic polypeptide (GIP) and glucagon-like peptide-1 (GLP1), were discovered 45 and 30 years ago. Initially, only their insulinotropic effect on pancreatic β cells was known. Over the years, physiological and pharmacological effects of GIP and GLP1 in numerous extrapancreatic tissues were discovered which partially overlap, but may also be specific for GIP or GLP1 in certain target tissues. While the insulinotropic effect of GIP was found to be blunted in patients with type 2 diabetes, the function of GLP1 is preserved and GLP1 receptor agonists and dipeptidyl-peptidase 4 (DPP4) inhibitors, which prolong the half-life of incretins, are widely used in diabetes therapy. Wild-type and genetically modified rodent models have provided important mechanistic insights into the incretin system, but may have limitations in predicting the clinical efficacy and safety of incretin-based therapies. This review summarizes insights from rodent and non-rodent models (pig, non-human primate) into physiological and pharmacological incretin effects, with a focus on the pancreas. Similarities and differences between species are discussed and the increasing potential of genetically engineered pig models for translational incretin research is highlighted. Topics: Animals; Animals, Genetically Modified; Diabetes Mellitus, Type 2; Disease Models, Animal; Gastric Inhibitory Polypeptide; Glucagon-Like Peptide 1; Glucagon-Like Peptide-1 Receptor; Hypoglycemic Agents; Incretins; Insulin; Insulin Secretion; Insulin-Secreting Cells; Liraglutide; Mice; Mice, Knockout; Primates; Receptors, Gastrointestinal Hormone; Rodentia; Swine | 2016 |
Gastrointestinal actions of glucagon-like peptide-1-based therapies: glycaemic control beyond the pancreas.
The gastrointestinal hormone glucagon-like peptide-1 (GLP-1) lowers postprandial glucose concentrations by regulating pancreatic islet-cell function, with stimulation of glucose-dependent insulin and suppression of glucagon secretion. In addition to endocrine pancreatic effects, mounting evidence suggests that several gastrointestinal actions of GLP-1 are at least as important for glucose-lowering. GLP-1 reduces gastric emptying rate and small bowel motility, thereby delaying glucose absorption and decreasing postprandial glucose excursions. Furthermore, it has been suggested that GLP-1 directly stimulates hepatic glucose uptake, and suppresses hepatic glucose production, thereby adding to reduction of fasting and postprandial glucose levels. GLP-1 receptor agonists, which mimic the effects of GLP-1, have been developed for the treatment of type 2 diabetes. Based on their pharmacokinetic profile, GLP-1 receptor agonists can be broadly categorized as short- or long-acting, with each having unique islet-cell and gastrointestinal effects that lower glucose levels. Short-acting agonists predominantly lower postprandial glucose excursions, by inhibiting gastric emptying and intestinal glucose uptake, with little effect on insulin secretion. By contrast, long-acting agonists mainly reduce fasting glucose levels, predominantly by increased insulin and reduced glucagon secretion, with potential additional direct inhibitory effects on hepatic glucose production. Understanding these pharmacokinetic and pharmacodynamic differences may allow personalized antihyperglycaemic therapy in type 2 diabetes. In addition, it may provide the rationale to explore treatment in patients with no or little residual β-cell function. Topics: Diabetes Mellitus, Type 2; Fasting; Gastric Emptying; Gastrointestinal Agents; Gastrointestinal Motility; Glucagon; Glucagon-Like Peptide 1; Glucose; Humans; Hypoglycemic Agents; Insulin; Insulin Secretion; Intestine, Small; Liver; Postprandial Period | 2016 |
Gastrointestinal dopamine as an anti-incretin and its possible role in bypass surgery as therapy for type 2 diabetes with associated obesity.
The objective of this review was to summarize and integrate specific clinical observations from the field of gastric bypass surgery and recent findings in beta cell biology. When considered together, these data sets suggest a previously unrecognized physiological mechanism which may explain how Roux-en-Y gastric bypass (RYGB) surgery mediates the early rapid reversal of hyperglycemia, observed before weight loss, in certain type 2 diabetes mellitus (T2DM) patients. The novel mechanism is based on a recently recognized inhibitory circuit of glucose stimulated insulin secretion driven by DA stored in β-cell vesicles and the gut. We propose that DA and glucagon-like peptide 1 (GLP-1) represent two opposing arms of a glucose stimulated insulin secretion (GSIS) regulatory system and hypothesize that dopamine represents the "anti-incretin" hypothesized to explain the beneficial effects of bariatric surgery on T2DM. These new hypotheses and the research driven by them may directly impact our understanding of: 1) the mechanisms underlying improved glucose homeostasis seen before weight loss following bariatric surgery; and 2) the regulation of glucose stimulated insulin secretion within islets. On a practical level, these studies may result in the development of novels drugs to modulate insulin secretion and/or methods to quantitatively asses in real time beta cell function and mass. Topics: Diabetes Mellitus, Type 2; Dopamine; Gastric Bypass; Gastrointestinal Tract; Glucagon-Like Peptide 1; Humans; Incretins; Obesity | 2016 |
Glucagon-Like Peptide-1 Formulation--the Present and Future Development in Diabetes Treatment.
Type 2 diabetes mellitus is a chronic metabolic disorder that has become the fourth leading cause of death in the developed countries. The disorder is characterized by pancreatic β-cells dysfunction, which causes hyperglycaemia leading to several other complications. Treatment by far, which focuses on insulin administration and glycaemic control, has not been satisfactory. Glucagon-like peptide-1 (GLP1) is an endogenous peptide that stimulates post-prandial insulin secretion. Despite being able to mimic the effect of insulin, GLP1 has not been the target drug in diabetes treatment due to the peptide's metabolic instability. After a decade-long effort to improve the pharmacokinetics of GLP1, a number of GLP1 analogues are currently available on the market. The current Minireview does not discuss these drugs but presents strategies that were undertaken to address the weaknesses of the native GLP1, particularly drug delivery techniques used in developing GLP1 nanoparticles and modified GLP1 molecule. The article highlights how each of the selected preparations has improved the efficacy of GLP1, and more importantly, through an overview of these studies, it will provide an insight into strategies that may be adopted in the future in the development of a more effective oral GLP1 formulation. Topics: Blood Glucose; Diabetes Mellitus, Type 2; Drug Delivery Systems; Glucagon-Like Peptide 1; Humans; Hyperglycemia; Hypoglycemic Agents; Insulin; Insulin-Secreting Cells; Nanoparticles; Postprandial Period | 2016 |
Treatment potential of the GLP-1 receptor agonists in type 2 diabetes mellitus: a review.
Over the last decade, the discovery of glucagon-like peptide 1 receptor agonists (GLP-1 RAs) has increased the treatment options for patients with type 2 diabetes mellitus (T2DM). GLP-1 RAs mimic the effects of native GLP-1, which increases insulin secretion, inhibits glucagon secretion, increases satiety and slows gastric emptying. This review evaluates the phase III trials for all approved GLP-1 RAs and reports that all GLP-1 RAs decrease HbA1c, fasting plasma glucose, and lead to a reduction in body weight in the majority of trials. The most common adverse events are nausea and other gastrointestinal discomfort, while hypoglycaemia is rarely reported when GLP-1 RAs not are combined with sulfonylurea or insulin. Treatment options in the near future will include co-formulations of basal insulin and a GLP-1 RA. Topics: Animals; Blood Glucose; Diabetes Mellitus, Type 2; Glucagon; Glucagon-Like Peptide 1; Glucagon-Like Peptide-1 Receptor; Humans; Hypoglycemic Agents; Insulin; Insulin Secretion | 2016 |
Liraglutide in Type 2 Diabetes Mellitus: Clinical Pharmacokinetics and Pharmacodynamics.
Liraglutide is an acylated glucagon-like peptide-1 analogue with 97 % amino acid homology with native glucagon-like peptide-1 and greatly protracted action. It is widely used for the treatment of type 2 diabetes mellitus, and administered by subcutaneous injection once daily. The pharmacokinetic properties of liraglutide enable 24-h exposure coverage, a requirement for 24-h glycaemic control with once-daily dosing. The mechanism of protraction relates to slowed release from the injection site, and a reduced elimination rate owing to metabolic stabilisation and reduced renal filtration. Drug exposure is largely independent of injection site, as well as age, race and ethnicity. Increasing body weight and male sex are associated with reduced concentrations, but there is substantial overlap between subgroups; therefore, dose escalation should be based on individual treatment outcome. Exposure is reduced with mild, moderate or severe renal or hepatic impairment. There are no clinically relevant changes in overall concentrations of various drugs (e.g. paracetamol, atorvastatin, griseofulvin, digoxin, lisinopril and oral combination contraceptives) when co-administered with liraglutide. Pharmacodynamic studies show multiple beneficial actions with liraglutide, including improved fasting and postprandial glycaemic control (mediated by increased insulin and reduced glucagon levels and minor delays in gastric emptying), reduced appetite and energy intake, and effects on postprandial lipid profiles. The counter-regulatory hormone response to hypoglycaemia is largely unaltered. The effects of liraglutide on insulin and glucagon secretion are glucose dependent, and hence the risk of hypoglycaemia is low. The pharmacokinetic and pharmacodynamic properties of liraglutide make it an important treatment option for many patients with type 2 diabetes. Topics: Area Under Curve; Blood Glucose; Body Weight; Diabetes Mellitus, Type 2; Drug Interactions; Glucagon; Glucagon-Like Peptide 1; Humans; Hypoglycemic Agents; Injections, Subcutaneous; Insulin; Lipids; Liraglutide; Liver Failure; Renal Insufficiency; Sex Factors | 2016 |
The regulation of function, growth and survival of GLP-1-producing L-cells.
Glucagon-like peptide-1 (GLP-1) is a peptide hormone, released from intestinal L-cells in response to hormonal, neural and nutrient stimuli. In addition to potentiation of meal-stimulated insulin secretion, GLP-1 signalling exerts numerous pleiotropic effects on various tissues, regulating energy absorption and disposal, as well as cell proliferation and survival. In Type 2 Diabetes (T2D) reduced plasma levels of GLP-1 have been observed, and plasma levels of GLP-1, as well as reduced numbers of GLP-1 producing cells, have been correlated to obesity and insulin resistance. Increasing endogenous secretion of GLP-1 by selective targeting of the molecular mechanisms regulating secretion from the L-cell has been the focus of much recent research. An additional and promising strategy for enhancing endogenous secretion may be to increase the L-cell mass in the intestinal epithelium, but the mechanisms that regulate the growth, survival and function of these cells are largely unknown. We recently showed that prolonged exposure to high concentrations of the fatty acid palmitate induced lipotoxic effects, similar to those operative in insulin-producing cells, in an in vitro model of GLP-1-producing cells. The mechanisms inducing this lipototoxicity involved increased production of reactive oxygen species (ROS). In this review, regulation of GLP-1-secreting cells is discussed, with a focus on the mechanisms underlying GLP-1 secretion, long-term regulation of growth, differentiation and survival under normal as well as diabetic conditions of hypernutrition. Topics: Animals; Cell Proliferation; Cell Survival; Diabetes Mellitus, Type 2; Enteroendocrine Cells; Glucagon-Like Peptide 1; Humans; Hypoglycemic Agents | 2016 |
Apolipoprotein A-I interactions with insulin secretion and production.
Human population studies have established that an elevated plasma high-density lipoprotein cholesterol (HDL-C) level is associated with a decreased risk of developing cardiovascular disease. In addition to having several potentially cardioprotective functions, HDLs and apolipoprotein (apo)A-I, the main HDL apolipoprotein, also have antidiabetic properties. Interventions that elevate plasma HDL-C and apoA-I levels improve glycemic control in people with type 2 diabetes mellitus by enhancing pancreatic β-cell function and increasing insulin sensitivity.. This review is concerned with recent advances in understanding the mechanisms by which HDLs and apoA-I improve pancreatic β-cell function.. HDLs and apoA-I increase insulin synthesis and secretion in pancreatic β cells. The underlying mechanism of this effect is similar to what has been reported for intestinally derived incretins, such as glucagon-like peptide-1 and glucose-dependent insulinotropic polypeptide, which both increase β-cell insulin secretion under high glucose conditions. This involves the activation of a heterotrimeric G protein Gαs subunit on the β-cell surface that leads to induction of a transmembrane adenylyl cyclase, increased intracellular cyclic adenosine monophosphate and Ca levels, and activation of protein kinase A. Protein kinase A increases insulin synthesis by excluding FoxO1 from the β-cell nucleus and derepressing transcription of the insulin gene. Topics: Animals; Apolipoprotein A-I; Diabetes Mellitus, Type 2; Glucagon-Like Peptide 1; Humans; Insulin; Insulin Secretion; Lipoproteins, HDL | 2016 |
Glucagon-Like Peptide-1 Receptor Agonists for Type 2 Diabetes: A Clinical Update of Safety and Efficacy.
Glucagon-like peptide-1 receptor agonists (GLP-1 RAs) are increasingly being used for the treatment of type 2 diabetes mellitus, but consideration of benefits and potential adverse events is required. This review examines the state of glycemic control, weight loss, blood pressure, and tolerability, as well as the current debate about the safety of GLP-1 RAs, including risk of pancreatitis, pancreatic cancer, and thyroid cancer.. A MEDLINE search (2010-2015) identified publications that discussed longer-acting GLP-1 RAs. Search terms included GLP-1 receptor agonists, liraglutide, exenatide, lixisenatide, semaglutide, dulaglutide, albiglutide, efficacy, safety, pancreatitis, pancreatic cancer, and thyroid cancer. Abstracts from the American Diabetes Association, European Association for the Study of Diabetes, and American Association of Clinical Endocrinologists from 2010 to 2015 were also searched. Efficacy and safety studies, pooled analyses, and meta-analyses were prioritized.. Research has confirmed that GLP-1 RAs provide robust glycemic control, weight loss, and blood pressure re-duction. Current studies do not prove increased risk of pancreatitis, pancreatic cancer, or thyroid cancer but more trials are needed since publications that indicate safety or suggest increased risk have methodological flaws that prevent firm conclusions to be drawn about these rare, long-term events.. GLP-1 RA therapy in the context of individualized, patient-centered care continues to be supported by current literature. GLP-1 RA therapy provides robust glycemic control, blood pressure reduction, and weight loss, but studies are still needed to address concerns about tolerability and safety, including pancreatitis and cancer. Topics: Blood Glucose; Diabetes Mellitus, Type 2; Exenatide; Glucagon-Like Peptide 1; Glucagon-Like Peptide-1 Receptor; Glucagon-Like Peptides; Humans; Hypoglycemic Agents; Immunoglobulin Fc Fragments; Peptides; Recombinant Fusion Proteins; Treatment Outcome; Venoms | 2016 |
Glucagon-like peptide-1 and gastric inhibitory polypeptide: new advances.
Glucagon-like peptide-1 (GLP-1) and gastric inhibitory polypeptide (GIP) are gastrointestinal peptides that play an important role as incretin hormones in the regulation of plasma glucose and insulin secretion. GLP-1-based therapies have therefore been implemented as treatment for type 2 diabetes (T2D). The purpose of this review is to summarize novel treatment options for T2D with GLP-1-based therapies. In addition, both peptides have relevant extrapancreatic effects that have been further characterized recently and are summarized in this review.. Novel findings regarding changes in GLP-1 secretion after bariatric surgery are highlighted, wherein GLP-1 plays a role in promoting body weight loss and diabetes remission. For T2D therapy, novel options with long-acting GLP-1 analogs are summarized that show a good efficacy and safety profile, also in combination with insulin as well as for obesity treatment. As GIP is not suitable for T2D therapy, extrapancreatic effects of GIP, mainly on bone metabolism that have been characterized recently, are described. These show that the activated GIP receptor is important to allow optimal bone mass and structure.. This review summarizes new findings on the physiology and pathophysiology of GLP-1 and GIP and novel therapeutic aspects. Topics: Diabetes Mellitus, Type 2; Gastric Inhibitory Polypeptide; Glucagon-Like Peptide 1; Humans | 2016 |
Cardiovascular Effects of Incretin-Based Therapies.
The incretin-based therapies, dipeptidyl peptidase-4 (DPP4) inhibitors and glucagon-like peptide-1 (GLP-1) analogs, are important new classes of therapy for type 2 diabetes mellitus (T2DM). These agents prolong the action of the incretin hormones, GLP-1 and glucose-dependent insulinotropic polypeptide (GIP), by inhibiting their breakdown. The incretin hormones improve glycemic control in T2DM by increasing insulin secretion and suppressing glucagon levels. The cardiovascular (CV) effects of the incretin-based therapies have been of substantial interest since 2008, when the US Food and Drug Administration began to require that all new therapies for diabetes undergo rigorous assessment of CV safety through large-scale CV outcome trials. This article reviews the most recent CV outcome trials of the DPP-4 inhibitors (SAVOR-TIMI 53, EXAMINE, and TECOS) as evidence that the incretin-based therapies have acceptable CV safety profiles for patients with T2DM. The studies differ with regard to patient population, trial duration, and heart failure outcomes but show similar findings for CV death, nonfatal myocardial infarction, and stroke, as well as hospitalization for unstable angina. Topics: Adamantane; Cardiovascular Diseases; Cardiovascular System; Clinical Trials as Topic; Diabetes Mellitus, Type 2; Dipeptides; Dipeptidyl-Peptidase IV Inhibitors; Glucagon-Like Peptide 1; Heart Failure; Humans; Hypoglycemic Agents; Incretins; Piperidines; Sitagliptin Phosphate; Uracil | 2016 |
Drug development from the bench to the pharmacy: with special reference to dipeptidyl peptidase-4 inhibitor development.
The dipeptidyl peptidase-4 (DPP-4) inhibitor concept is an example of prospective drug design and development based upon a distinct endocrine hypothesis. The design of enzyme inhibitors is a pragmatic approach to drug design; being compatible with the identification and optimization of small molecules that have properties commensurate with oral administration, as well as acceptable drug metabolism, distribution and elimination characteristics. Glucagon-like peptide 1 (GLP-1), a hormone with a spectrum of favourable metabolic actions, including glucose-dependent stimulation of insulin and inhibition of glucagon secretion, provided the endocrine basis from which the idea of using DPP-4 inhibitors as anti-diabetic agents was developed. The origin of the DPP-4 inhibitor concept was inspired by the angiotensin-converting enzyme inhibitor approach, which succeeded in establishing a class of extensively used therapeutic agents for the treatment of cardiovascular disorders. Topics: Diabetes Mellitus, Type 2; Diffusion of Innovation; Dipeptidyl-Peptidase IV Inhibitors; Drug Discovery; Forecasting; Glucagon-Like Peptide 1; Humans; Renin-Angiotensin System | 2016 |
Albiglutide: Is a better hope against diabetes mellitus?
Type-2 diabetes mellitus (T2DM) is the chronic metabolic disorder which provokes several pitfall signalling. Though, a series of anti-diabetic drugs are available in the market but T2DM is still a huge burden on the developed and developing countries. Numerous studies and survey predict the associated baleful circumstances in near future due to incessant increase in this insidious disorder. The novelty of recent explored anti-diabetic drugs including glitazone, glitazaar and gliflozines seems to be vanished due to their associated toxic side effects. Brown and Dryburgh (1970) isolated an intestinal amino acid known as gastric inhibitory peptide (GIP) which had insulinotropic activity. Subsequently in 1985, another incretin glucagon likes peptide 1 (GLP-1) having potent insulinotropic properties was discovered by Schmidt and his co-workers. On the basis of results' obtained by Phase III Harmony program FDA approved (14 April, 2014) new GLP-1 agonist 'Albiglutide (ALB)', in addition to exiting components Exenatide (Eli Lilly, 2005) and Liraglutide (Novo Nordisk, 2010). ALB stimulates the release of protein kinase A (PKA) via different mechanisms which ultimately leads to increase in intracellular Ca(2+) levels. This increased intracellular Ca(2+) releases insulin vesicle from β-cells. In-addition, ALB being resistant to degradation by dipeptidyl peptidase-4 (DPP-4) and has longer half life. DPP-4 can significantly degrade the level of GLP-1 agonist by hydrolysis. In spite of potent anti-hypergycemic activity, ALB has pleiotropic action of improving cardiovascular physiology. In light of these viewpoints we reveal the individual pharmacological profile of ALB and the critical analyse about its future perspective in present review. Topics: Animals; Calcium; Clinical Trials as Topic; Cyclic AMP-Dependent Protein Kinases; Diabetes Mellitus, Type 2; Dipeptidyl Peptidase 4; Gastric Inhibitory Polypeptide; Glucagon-Like Peptide 1; Guanine Nucleotide Exchange Factors; Half-Life; Humans; Hypoglycemic Agents; Insulin-Secreting Cells | 2016 |
A Comprehensive Review of Novel Drug-Disease Models in Diabetes Drug Development.
Type 2 diabetes mellitus (T2DM) is a chronic metabolic disease, which affects millions of people worldwide. The disease is characterized by chronically elevated blood glucose concentrations (hyperglycaemia), which result in comorbidities and multi-organ dysfunction. This is due to a gradual loss of glycaemic control as a result of increasing insulin resistance, as well as decreasing β-cell function. The objective of T2DM drug interventions is, therefore, to reduce fasting and postprandial blood glucose concentrations to normal, healthy levels without hypoglycaemia. Several classes of novel antihyperglycaemic drugs with various mechanisms of action have been developed over the past decades or are currently under clinical development. The development of these drugs is routinely supported by the application of pharmacokinetic/pharmacodynamic modelling and simulation approaches. They integrate information on the drug's pharmacokinetics, clinically relevant biomarker information and disease progression into a single, unifying approach, which can be used to inform clinical study design, dose selection and drug labelling. The objective of this review is to provide a comprehensive overview of the quantitative approaches that have been reported since the 2008 review by Landersdorfer and Jusko in an increasing order of complexity, starting with glucose homeostasis models. Each of the presented approaches is discussed with respect to its strengths and limitations, and respective knowledge gaps are highlighted as potential opportunities for future drug-disease model development in the area of T2DM. Topics: Biomarkers; Blood Glucose; Diabetes Mellitus, Type 2; Dipeptidyl-Peptidase IV Inhibitors; Glucagon-Like Peptide 1; Glucokinase; Glycated Hemoglobin; Humans; Hyperglycemia; Hypoglycemic Agents; Incretins; Insulin; Models, Biological; Receptors, G-Protein-Coupled; Receptors, Glucagon; Sodium-Glucose Transporter 2 Inhibitors | 2016 |
Glucagon-like peptide-1 agonists combating clozapine-associated obesity and diabetes.
Clozapine is the most effective antipsychotic, but its use is tempered by adverse metabolic effects such as weight gain, glucose intolerance and type II diabetes. Current interventions do not facilitate compelling or sustained improvement in metabolic status. Recent studies suggest that glucagon-like peptide-1 (GLP-1) may play a key role in clozapine's metabolic effects, possibly suggesting that clozapine-associated obesity and diabetes are mediated independently through reduced GLP-1. As a result, GLP-1 agonists could show promise in reversing antipsychotic-induced metabolic derangements, providing mechanistic justification that they may represent a novel approach to treat, and ultimately prevent, both diabetes and obesity in patients on clozapine. GLP-1 agonists are already used for diabetes, and they provide a unique combination of glycaemic improvement and metabolically relevant weight loss in diabetic and non-diabetic patients, in the context of a currently favourable safety profile. Using GLP-1 agonists for clozapine-associated obesity and diabetes could be a potentially effective intervention that may reduce cardiometabolic morbidity and mortality in this vulnerable patient population. Topics: Animals; Antipsychotic Agents; Clozapine; Diabetes Mellitus, Type 2; Glucagon-Like Peptide 1; Humans; Obesity | 2016 |
Potentials of incretin-based therapies in dementia and stroke in type 2 diabetes mellitus.
Patients with type 2 diabetes mellitus are at risk for accelerated cognitive decline and dementia. Furthermore, their risk of stroke is increased and their outcome after stroke is worse than in those without diabetes. Incretin-based therapies are a class of antidiabetic agents that are of interest in relation to these cerebral complications of diabetes. Two classes of incretin-based therapies are currently available: the glucagon-like-peptide-1 agonists and the dipeptidyl peptidase-4 -inhibitors. Independent of their glucose-lowering effects, incretin-based therapies might also have direct or indirect beneficial effects on the brain. In the present review, we discuss the potential of incretin-based therapies in relation to dementia, in particular Alzheimer's disease, and stroke in patients with type 2 diabetes. Experimental studies on Alzheimer's disease have found beneficial effects of incretin-based therapies on cognition, synaptic plasticity and metabolism of amyloid-β and microtubule-associated protein tau. Preclinical studies on incretin-based therapies in stroke have shown an improved functional outcome, a reduction of infarct volume as well as neuroprotective and neurotrophic properties. Both with regard to the treatment of Alzheimer's disease, and with regard to prevention and treatment of stroke, randomized controlled trials in patients with or without diabetes are underway. In conclusion, experimental studies show promising results of incretin-based therapies at improving the outcome of Alzheimer's disease and stroke through glucose-independent pleiotropic effects on the brain. If these findings would indeed be confirmed in large clinical randomized controlled trials, this would have substantial impact. Topics: Animals; Clinical Trials as Topic; Dementia; Diabetes Mellitus, Type 2; Dipeptidyl-Peptidase IV Inhibitors; Glucagon-Like Peptide 1; Humans; Hypoglycemic Agents; Incretins; Stroke | 2016 |
Cut to the chase: a review of CD26/dipeptidyl peptidase-4's (DPP4) entanglement in the immune system.
CD26/DPP4 (dipeptidyl peptidase 4/DP4/DPPIV) is a surface T cell activation antigen and has been shown to have DPP4 enzymatic activity, cleaving-off amino-terminal dipeptides with either L-proline or L-alanine at the penultimate position. It plays a major role in glucose metabolism by N-terminal truncation and inactivation of the incretins glucagon-like peptide-1 (GLP) and gastric inhibitory protein (GIP). In 2006, DPP4 inhibitors have been introduced to clinics and have been demonstrated to efficiently enhance the endogenous insulin secretion via prolongation of the half-life of GLP-1 and GIP in patients. However, a large number of studies demonstrate clearly that CD26/DPP4 also plays an integral role in the immune system, particularly in T cell activation. Therefore, inhibition of DPP4 might represent a double-edged sword. Apart from the metabolic benefit, the associated immunological effects of long term DPP4 inhibition on regulatory processes such as T cell homeostasis, maturation and activation are not understood fully at this stage. The current data point to an important role for CD26/DPP4 in maintaining lymphocyte composition and function, T cell activation and co-stimulation, memory T cell generation and thymic emigration patterns during immune-senescence. In rodents, critical immune changes occur at baseline levels as well as after in-vitro and in-vivo challenge. In patients receiving DPP4 inhibitors, evidence of immunological side effects also became apparent. The scope of this review is to recapitulate the role of CD26/DPP4 in the immune system regarding its pharmacological inhibition and T cell-dependent immune regulation. Topics: Animals; Cell Movement; Chemokines; Cytokines; Diabetes Mellitus, Type 2; Dipeptidyl Peptidase 4; Dipeptidyl-Peptidase IV Inhibitors; Gene Expression Regulation; Glucagon-Like Peptide 1; Glucose; Humans; Immunity, Innate; Immunologic Memory; Insulin; Lymphocyte Activation; T-Lymphocytes | 2016 |
Efficacy and safety of liraglutide, a once-daily human glucagon-like peptide-1 analogue, in Latino/Hispanic patients with type 2 diabetes: post hoc analysis of data from four phase III trials.
The aim of the present analysis was to evaluate the efficacy of the glucagon-like peptide-1 receptor agonist liraglutide in Latino/Hispanic individuals with type 2 diabetes, in addition to comparing its treatment effects with those observed in non-Latino/Hispanic individuals. Analyses were performed on patient-level data from a subset of individuals self-defined as Latino/Hispanic from four phase III studies, the LEAD-3, LEAD-4, LEAD-6 and 1860-LIRA-DPP-4 trials. Endpoints included change in glycated haemoglobin (HbA1c) and body weight from baseline. In Latino/Hispanic patients (n = 505; 323 treated with liraglutide) after 26 weeks, mean HbA1c reductions were significantly greater with both liraglutide 1.2 and 1.8 mg versus comparator or placebo in the LEAD-3 and LEAD-4 studies, and with 1.8 mg liraglutide in the 1860-LIRA-DPP-4 trial. In LEAD-3 both doses led to significant differences in body weight change among Latino/Hispanic patients versus the comparator. With 1.8 mg liraglutide, difference in weight change was significant only in the 1860-LIRA-DPP-4 trial versus sitagliptin. For both endpoints Latino/Hispanic and non-Latino/Hispanic patients responded to liraglutide similarly. In summary, liraglutide is efficacious for treatment of type 2 diabetes in Latino/Hispanic patients, with a similar efficacy to that seen in non-Latino/Hispanic patients. Topics: Blood Glucose; Clinical Trials, Phase III as Topic; Diabetes Mellitus, Type 2; Double-Blind Method; Drug Administration Schedule; Glucagon-Like Peptide 1; Glycated Hemoglobin; Hispanic or Latino; Humans; Hypoglycemic Agents; Liraglutide; Randomized Controlled Trials as Topic; Treatment Outcome | 2016 |
Glucose-dependent insulinotropic polypeptide: effects on insulin and glucagon secretion in humans.
The hormones glucose-dependent insulinotropic polypeptide (GIP) and glucagon-like peptide-1 (GLP-1) are secreted by enteroendocrine cells in the intestinal mucosa in response to nutrient ingestion. They are called incretin hormones because of their ability to enhance insulin secretion. However, in recent years it has become clear that the incretin hormones also affect glucagon secretion. While GLP-1 decreases glucagon levels, the effect of GIP on glucagon levels has been unclear. The regulation of glucagon secretion is interesting, as the combination of inadequate insulin secretion and excessive glucagon secretion are essential contributors to the hyperglycaemia that characterise patients with type 2 diabetes. Moreover, the near absence of a well-timed glucagon response contributes to an increased risk of hypoglycaemia in patients with type 1 diabetes. The overall aim of this PhD thesis was to investigate how the blood glucose level affects the glucagon and insulin responses to GIP in healthy subjects (Study 1) and patients with Type 2 diabetes (Study 2), and more specifically to investigate the effects of GIP and GLP-1 at low blood glucose in patients with Type 1 diabetes without endogenous insulin secretion (Study 3). The investigations in the three mentioned study populations have been described in three original articles. The employed study designs were in randomised, placebo-controlled, crossover set-up, in which the same research subject is subjected to several study days thereby acting as his own control. Interventions were intravenous administration of hormones GIP, GLP-1 and placebo (saline) during different blood glucose levels maintained (clamped) at a certain level. The end-points were plasma concentrations of glucagon and insulin as well as the amount of glucose used to clamp the blood glucose levels. In Study 3, we also used stable glucose isotopes to estimate the endogenous glucose production and assessed symptoms and cognitive function during hypoglycaemia. The results from the three studies indicate that GIP has effects on insulin and glucagon responses highly dependent upon the blood glucose levels. At fasting glycaemia and lower levels of glycaemia, GIP acts to increase glucagon with little effect on insulin release. At hyperglycaemia the insulin releasing effect of GIP prevail, which lead to an increase in glucose disposal by approximately 75% in healthy subjects (Study 1) and 25% in patients with Type 2 diabetes (Study 2) relative to Topics: Adult; Blood Glucose; Diabetes Mellitus, Type 1; Diabetes Mellitus, Type 2; Gastric Inhibitory Polypeptide; Glucagon; Glucagon-Like Peptide 1; Humans; Hyperglycemia; Hypoglycemia; Insulin; Insulin Secretion; Male; Randomized Controlled Trials as Topic | 2016 |
Reappraisal of GIP Pharmacology for Metabolic Diseases.
Glucagon-like peptide-1 (GLP-1) analogs are considered the best current medicines for type 2 diabetes (T2D) and obesity due to their actions in lowering blood glucose and body weight. Despite similarities to GLP-1, glucose-dependent insulinotropic polypeptide (GIP) has not been extensively pursued as a medical treatment for T2D. This is largely based on observations of diminished responses of GIP to lower blood glucose in select patients, as well as evidence from rodent knockout models implying that GIP promotes obesity. These findings have prompted the belief in some, that inhibiting GIP action might be beneficial for metabolic diseases. However, a growing body of new evidence - including data based on refined genetically modified models and improved pharmacological agents - suggests a paradigm shift on how the GIP system should be manipulated for metabolic benefits. Topics: Animals; Blood Glucose; Diabetes Mellitus, Type 2; Gastric Inhibitory Polypeptide; Glucagon-Like Peptide 1; Humans; Insulin; Metabolic Diseases; Mice; Obesity; Receptors, Gastrointestinal Hormone | 2016 |
Postprandial plasma glucose effects of once-weekly albiglutide for the treatment of type 2 diabetes.
Glucagon-like peptide 1 receptor agonists (GLP-1 RAs) vary in their structure, duration of action, efficacy, and safety. In order to optimize glycemic control, it is important to target both fasting (FPG) and postprandial plasma (PPG) glucose. Although phase 3 trials document the effect of GLP-1 RAs on glycated hemoglobin, few data are available to assess their effect on PPG. Albiglutide is a once-weekly GLP-1 RA with a half-life of ≈ 5 days. The goal of this review is to summarize the effects of albiglutide on PPG in four phase 2 trials and to describe the PPG-lowering effects of the GLP-1 RAs. At clinically relevant doses (30-64 mg), albiglutide consistently lowered PPG after each meal in addition to its effect on lowering FPG. Multiple weekly subcutaneous injections of albiglutide led to improvements in a variety of glycemic measures, including maximal reductions in PPG from baseline, postmeal glucose excursions, and FPG. Albiglutide, a longer-acting GLP-1 RAs, provides reductions in FPG, PPG following meals, and glucose over 24 hours. Topics: Blood Glucose; Clinical Trials, Phase II as Topic; Diabetes Mellitus, Type 2; Glucagon-Like Peptide 1; Humans; Hypoglycemic Agents; Multicenter Studies as Topic; Postprandial Period; Randomized Controlled Trials as Topic | 2016 |
Glucagon-like peptide-1(GLP-1) receptor agonists: potential to reduce fracture risk in diabetic patients?
This review summarizes current knowledge about glucagon-like peptide 1 receptor agonists (GLP-1 RA) and their effects on bone metabolism and fracture risk. Recent in vivo and in vitro experiments indicated that GLP-1 RA could improve bone metabolism. GLP-1 could affect the fat-bone axis by promoting osteogenic differentiation and inhibiting adipogenic differentiation of bone mesenchymal precursor cells (BMSCs), which express the GLP-1 receptor. GLP-1 RA may also influence the balance between osteoclasts and osteoblasts, thus leading to more bone formation and less bone resorption. Wnt/β-catenin signalling is involved in this process. Mature osteocytes, which also express the GLP-1 receptor, produce sclerostin which inhibits Wnt/β-catenin signalling by binding to low density lipoprotein receptor-related protein (LRP) 5 and preventing the binding of Wnt. GLP-1 RA also decreases the expression of sclerostin (SOST) and circulating levels of SOST. In addition, GLP-1 receptors are expressed in thyroid C cells, where GLP-1 induces calcitonin release and thus indirectly inhibits bone resorption. Furthermore, GLP-1 RA influences the osteoprotegerin(OPG)/receptor activator of nuclear factor-κB ligand (RANKL)/receptor activator of nuclear factor-κB (RANK) system by increasing OPG gene expression, and thus reverses the decreased bone mass in rats models. However, a recent meta-analysis and a cohort study did not show a significant relationship between GLP-RA use and fracture risk. Future clinical trials will be necessary to investigate thoroughly the relationship between GLP-1 RA use and fracture risk in diabetic patients. Topics: Animals; beta Catenin; Bone Density; Calcitonin; Diabetes Mellitus, Type 2; Fractures, Bone; Glucagon-Like Peptide 1; Glucagon-Like Peptide-1 Receptor; Humans; Osteoporosis; RANK Ligand; Risk; Wnt Signaling Pathway | 2016 |
Bioavailability of milk protein-derived bioactive peptides: a glycaemic management perspective.
Milk protein-derived peptides have been reported to have potential benefits for reducing the risk of type 2 diabetes. However, what the active components are and whether intact peptides exert this bioactivity has received little investigation in human subjects. Furthermore, potentially useful bioactive peptides can be limited by low bioavailability. Various peptides have been identified in the gastrointestinal tract and bloodstream after milk-protein ingestion, providing valuable insights into their potential bioavailability. However, these studies are currently limited and the structure and sequence of milk peptides exerting bioactivity for glycaemic management has received little investigation in human subjects. The present article reviews the bioavailability of milk protein-derived peptides in human studies to date, and examines the evidence on milk proteins and glycaemic management, including potential mechanisms of action. Areas in need of advancement are identified. Only by establishing the bioavailability of milk protein-derived peptides, the active components and the mechanistic pathways involved can the benefits of milk proteins for the prevention or management of type 2 diabetes be fully realised in future. Topics: Biological Availability; Diabetes Mellitus, Type 2; Dipeptidyl Peptidase 4; Gastric Inhibitory Polypeptide; Glucagon-Like Peptide 1; Humans; Milk Proteins; Peptides | 2016 |
Anti-Inflammatory Effects of GLP-1-Based Therapies beyond Glucose Control.
Glucagon-like peptide-1 (GLP-1) is an incretin hormone mainly secreted from intestinal L cells in response to nutrient ingestion. GLP-1 has beneficial effects for glucose homeostasis by stimulating insulin secretion from pancreatic beta-cells, delaying gastric emptying, decreasing plasma glucagon, reducing food intake, and stimulating glucose disposal. Therefore, GLP-1-based therapies such as GLP-1 receptor agonists and inhibitors of dipeptidyl peptidase-4, which is a GLP-1 inactivating enzyme, have been developed for treatment of type 2 diabetes. In addition to glucose-lowering effects, emerging data suggests that GLP-1-based therapies also show anti-inflammatory effects in chronic inflammatory diseases including type 1 and 2 diabetes, atherosclerosis, neurodegenerative disorders, nonalcoholic steatohepatitis, diabetic nephropathy, asthma, and psoriasis. This review outlines the anti-inflammatory actions of GLP-1-based therapies on diseases associated with chronic inflammation in vivo and in vitro, and their molecular mechanisms of anti-inflammatory action. Topics: Animals; Anti-Inflammatory Agents; Blood Glucose; Diabetes Mellitus, Type 2; Glucagon-Like Peptide 1; Humans; Inflammation | 2016 |
The incretin system ABCs in obesity and diabetes - novel therapeutic strategies for weight loss and beyond.
Incretins are gastrointestinal-derived hormones released in response to a meal playing a key role in the regulation of postprandial secretion of insulin (incretin effect) and glucagon by the pancreas. Both incretins, glucose-dependent insulinotropic polypeptide and glucagon-like peptide-1 (GLP-1), have several other actions by peripheral and central mechanisms. GLP-1 regulates body weight by inhibiting appetite and delaying gastric, emptying actions that are dependent on central nervous system GLP-1 receptor activation. Several other hormones and gut peptides, including leptin and ghrelin, interact with GLP-1 to modulate appetite. GLP-1 is rapidly degraded by the multifunctional enzyme dipeptidyl peptidase-4 (DPP-4). DPP-4 is involved in adipose tissue inflammation, which is associated with insulin resistance and diabetes progression, being a common pathophysiological mechanism in obesity-related complications. Furthermore, the incretin system appears to provide the basis for understanding the high weight loss efficacy of bariatric surgery, a widely used treatment for obesity, often in association with diabetes. The present review brings together new insights into obesity pathogenesis, integrating GLP-1 and DPP-4 in the complex interplay between obesity and inflammation, namely, in diabetic patients. This in turn will provide the basis for novel incretin-based therapeutic strategies for obesity and diabetes with promising benefits in addition to weight loss. © 2016 World Obesity. Topics: Animals; Diabetes Mellitus, Type 2; Dipeptidyl Peptidase 4; Disease Models, Animal; Gastric Inhibitory Polypeptide; Glucagon-Like Peptide 1; Glucagon-Like Peptide-1 Receptor; Humans; Incretins; Insulin; Insulin Secretion; Obesity; Weight Loss | 2016 |
Evogliptin: a new dipeptidyl peptidase inhibitor for the treatment of type 2 diabetes.
Dipeptidyl peptidase-4 (DPP-4) inhibitors are novel, potent oral antihyperglycemic agents that reduce degradation of endogenous glucagon-like peptide 1 (GLP-1) to increase insulin secretion and satiety and decrease glucagon. DPP-4 inhibitors enhance insulin secretion in a glucose-dependent manner, which potentially reduces hypoglycemia risks during monotherapy or combination therapy with other antidiabetic agents. Evogliptin (Suganon(TM)) is a new oral DPP-4 inhibitor developed for the treatment of patients with type 2 diabetes inadequately controlled by diet and exercise.. This review summarizes the collected data concerning mechanism of action, clinical efficacy, and safety of evogliptin in improving glycemic control in patients with type 2 diabetes. Additional non-glycemic benefits and safety profiles of evogliptin are also discussed.. Evogliptin is effective in improving glycosylated hemoglobin (HbA1c) and fasting plasma glucose without inducing hypoglycemia events, which potentially can improve adherence and prevent complications. It is also found that evogliptin has benefits on insulin secretory and β-cell functions. Based on the current clinical data, evogliptin has a neutral effect on body weight. These attributes contribute to the clinical practice in monotherapy or in combination with other antidiabetic agents. Topics: Angiotensin-Converting Enzyme Inhibitors; Blood Glucose; Diabetes Mellitus, Type 2; Dipeptidyl-Peptidase IV Inhibitors; Drug Therapy, Combination; Glucagon-Like Peptide 1; Glucose; Glycated Hemoglobin; Humans; Hypoglycemia; Hypoglycemic Agents; Insulin; Piperazines | 2016 |
Diabetes and obesity treatment based on dual incretin receptor activation: 'twincretins'.
The gut incretin hormones glucose-dependent insulinotropic polypeptide (GIP) and glucagon-like peptide-1 (GLP-1) are secreted after meal ingestion and work in concert to promote postprandial insulin secretion and regulate glucagon secretion. GLP-1 also slows gastric emptying and suppresses appetite, whereas GIP seems to affect lipid metabolism. The introduction of selective GLP-1 receptor (GLP-1R) agonists for the treatment of type 2 diabetes and obesity has increased the scientific and clinical interest in incretins. Combining the body weight-lowering and glucose-lowering effects of GLP-1 with a more potent improvement of β cell function through additional GIP action could potentially offer a more effective treatment of diabetes and obesity, with fewer adverse effects than selective GLP-1R agonists; therefore, new drugs designed to co-activate both the GIP receptor (GIPR) and the GLP-1R simultaneously are under development. In the present review, we address advances in the field of GIPR and GLP-1R co-agonism and review in vitro studies, animal studies and human trials involving co-administration of the two incretins, as well as results from a recently developed GIPR/GLP-1R co-agonist, and highlight promising areas and challenges within the field of incretin dual agonists. Topics: Animals; Blood Glucose; Diabetes Mellitus, Type 2; Gastric Inhibitory Polypeptide; Glucagon-Like Peptide 1; Glucagon-Like Peptide-1 Receptor; Humans; In Vitro Techniques; Incretins; Insulin; Insulin-Secreting Cells; Obesity; Receptors, Gastrointestinal Hormone; Weight Loss | 2016 |
[Drugs affecting the incretin system and renal glucose transport: do they meet the expectations of modern therapy of type 2 diabetes?].
Agents introduced into therapy of type 2 diabetes in the last few years are still the subject of numerous clinical and experimental studies. Although many studies have been completed, we still do not know all aspects of these drugs' action, especially the long-term effects of their use. Most questionable is their impact on the processes of cell proliferation, on the cardiovascular and immune systems, on lipids and uric acid metabolism. A summary of the most important observations on the use of three groups of new drugs - analogs of glucagon-like peptide 1 (GLP-1), inhibitors of dipeptidyl peptidase IV (DPPIV) and inhibitors of sodium glucose cotransporters (SGLT1 and SGLT2) - has been made, based on a review of the literature over the past five years (2010-2014). The information included in the present review concerns the structure and activity relationship, therapeutic efficacy, side effects and the observed additional therapeutic effects, which can determine new standards in therapy of diabetes and also facilitate the development of better antidiabetic drugs. Topics: Diabetes Mellitus, Type 2; Dipeptidyl-Peptidase IV Inhibitors; Glucagon-Like Peptide 1; Glucose; Humans; Hypoglycemic Agents; Incretins; Sodium-Glucose Transporter 1; Sodium-Glucose Transporter 2; Sodium-Glucose Transporter 2 Inhibitors | 2016 |
Contribution of the distal small intestine to metabolic improvement after bariatric/metabolic surgery: Lessons from ileal transposition surgery.
Roux-en Y gastric bypass is a highly effective bariatric/metabolic surgical procedure that can induce robust weight loss and even remission of type 2 diabetes. One of the characteristic consequences of Roux-en Y gastric bypass is the expedited nutrient delivery to the distal small intestine, where L-cells are abundant and bile acid reabsorption occurs. To examine the role of the distal small intestine in isolation from other components of Roux-en Y gastric bypass, the ileal transposition (IT) surgery has been used in various rat models. IT relocates the distal ileal segment to the upper jejunum distal to the ligament of Treitz without any other alterations in the gastrointestinal anatomy. Therefore, IT exposes the distal ileal tissue to ingested nutrients after a meal faster than the normal condition. Although there is some inconsistency in the effect of IT according to different types of rat models and different types of surgical protocols, IT typically improved glucose tolerance, increased insulin sensitivity and induced weight loss, and the findings were more prominent in obese diabetic rats. Suggested mechanisms for the metabolic improvements after IT include increased L-cell secretion (e.g., glucagon-like peptides and peptide YY), altered bile acid metabolism, altered host-microbial interaction, attenuated metabolic endotoxemia and many others. Based on the effect of IT, we can conclude that the contribution of the distal small intestine to the metabolic benefits of bariatric/metabolic surgery is quite considerable. By unveiling the mechanism of action of IT, we might revolutionize the treatment for obesity and type 2 diabetes. Topics: Animals; Body Weight; Diabetes Mellitus, Type 2; Disease Models, Animal; Eating; Endotoxemia; Enteroendocrine Cells; Gastric Bypass; Gastrointestinal Microbiome; Glucagon; Glucagon-Like Peptide 1; Glucose Tolerance Test; Ileum; Insulin; Insulin Resistance; Insulin Secretion; Rats | 2016 |
Treating Diabetes in Patients with Heart Failure: Moving from Risk to Benefit.
Over the past two decades, therapeutics for diabetes have evolved from drugs with known heart failure risk to classes with potential benefit for patients with heart failure. As many as 25 to 35 % of patients with heart failure carry a diagnosis of type 2 diabetes mellitus. Therefore, newer drug classes including dipeptidyl peptidase 4 (DPP-4) inhibitors, glucagon-like peptide 1 (GIP-1) agonists, and sodium-glucose cotransporter 2 (SGLT-2) inhibitors are being examined for cardiovascular safety as well as their effects on left ventricular function, quality of life, and other measures of disease progression. The purpose of this review is to summarize the existing evidence on these classes of anti-diabetic agents in patients with heart failure. Topics: Blood Glucose; Diabetes Mellitus, Type 2; Dipeptidyl-Peptidase IV Inhibitors; Disease Progression; Glucagon-Like Peptide 1; Heart Failure; Humans; Hypoglycemic Agents; Quality of Life; Sodium-Glucose Transporter 2; Sodium-Glucose Transporter 2 Inhibitors; Ventricular Function, Left | 2016 |
Pharmacologic Therapy of Type 2 Diabetes.
Type 2 diabetes (T2DM) is a common condition. Treatment of diabetes and related complications can be complex. In addition to lifestyle changes, medications play an important role in controlling patients' blood glucose levels and preventing complications. From an individual and societal standpoint, it is also an expensive disease. Medical spending attributed to diabetes per individual is significant. With appropriate therapy, patients can lead full, healthy lives with the disease, so making informed decisions regarding pharmacotherapy for T2DM is clearly of great importance. Topics: Aging; Blood Glucose; Body Weight; Diabetes Mellitus, Type 2; Dipeptidyl-Peptidase IV Inhibitors; Drug Administration Routes; Glucagon-Like Peptide 1; Glycated Hemoglobin; Humans; Hypoglycemic Agents; Insulin; Metformin; Renal Insufficiency; Sodium-Glucose Transporter 2 Inhibitors; Sulfonylurea Compounds; Thiazolidinediones | 2016 |
Involvement of glucagon-like peptide-1 in the glucose-lowering effect of metformin.
Metformin is an oral antihyperglycaemic drug used in the first-line treatment of type 2 diabetes. Metformin's classic and most well-known blood glucose-lowering mechanisms include reduction of hepatic gluconeogenesis and increased peripheral insulin sensitivity. Interestingly, intravenously administered metformin is ineffective and recently, metformin was shown to increase plasma concentrations of the glucose-lowering gut incretin hormone glucagon-like peptide-1 (GLP-1), which may contribute to metformin's glucose-lowering effect in patients with type 2 diabetes. The mechanisms behind metformin-induced increments in GLP-1 levels remain unknown, but it has been hypothesized that metformin stimulates GLP-1 secretion directly and/or indirectly and that metformin prolongs the half-life of GLP-1. Also, it has been suggested that metformin may potentiate the glucose-lowering effects of GLP-1 by increasing target tissue sensitivity to GLP-1. The present article critically reviews the possible mechanisms by which metformin may affect GLP-1 levels and sensitivity and discusses whether such alterations may constitute important and clinically relevant glucose-lowering actions of metformin. Topics: Bile Acids and Salts; Blood Glucose; Diabetes Mellitus, Type 2; Gastrointestinal Microbiome; Glucagon-Like Peptide 1; Humans; Hypoglycemic Agents; Incretins; Metformin | 2016 |
[Management of Type 2 Diabetes: a Practical Approach].
Over the last years, the therapeutic aims for patients with type 2 diabetes have changed and several novel drugs have been introduced. In this Mini-Review we discuss these aims and how to achieve them. Topics: Combined Modality Therapy; Diabetes Mellitus, Type 2; Dipeptidyl-Peptidase IV Inhibitors; Glucagon-Like Peptide 1; Humans; Hypoglycemic Agents; Insulin; Life Style; Metformin; Sodium-Glucose Transporter 2; Sodium-Glucose Transporter 2 Inhibitors | 2016 |
Mechanisms of surgical control of type 2 diabetes: GLP-1 is key factor.
GLP-1 secretion in response to meals is dramatically increased after gastric bypass operations. GLP-1 is a powerful insulinotropic and anorectic hormone, and analogs of GLP-1 are widely used for the treatment of diabetes and recently approved also for obesity treatment. It is, therefore, reasonable to assume that the exaggerated GLP-1 secretion contributes to the antidiabetic and anorectic effects of gastric bypass. Indeed, human experiments with the GLP-1 receptor antagonist, Exendin 9-39, have shown that the improved insulin secretion, which is responsible for part of the antidiabetic effect of the operation, is reduced and or abolished after GLP-1 receptor blockade. Also the postoperative improvement of glucose tolerance is eliminated and or reduced by the antagonist, pointing to a key role for the exaggerated GLP-1 secretion. Indeed, there is evidence that the exaggerated GLP-1 secretion is also responsible for postprandial hypoglycemia sometimes observed after bypass. Other operations (biliopancreatic-diversion and or sleeve gastrectomy) appear to involve different and/or additional mechanisms, and so does experimental bariatric surgery in rodents. However, unlike bypass surgery in humans, the rodent operations are generally associated with increased energy metabolism pointing to an entirely different mechanism of action in the animals. Topics: Animals; Bile Acids and Salts; Diabetes Mellitus, Type 2; Disease Models, Animal; Gastric Bypass; Gastrointestinal Hormones; Glucagon-Like Peptide 1; Glucagon-Like Peptide 2; Humans; Insulin; Insulin Secretion; Intestinal Absorption; Mice; Obesity; Peptide Fragments; Remission Induction | 2016 |
GLP-1 is not the key mediator of the health benefits of metabolic surgery.
The identification of key factors accounting for the health benefits of metabolic surgery is a research priority, as it may help design a medical therapy mimicking this powerful surgical tool. Because of its well-known effects on glucose metabolism and appetite, amongst the several proposed factors, glucagon-like peptide-1 (GLP-1) has been the most extensively evaluated. A large number of association studies have been reported suggesting that the striking changes in GLP-1 after Roux-en-Y gastric bypass and sleeve gastrectomy play a role in the metabolic benefits associated with these surgical techniques. In this review article, we challenge this view. Studies in humans using the specific GLP-1 receptor antagonist exendin 9-39 or the nonspecific inhibitor of GLP-1 secretion octreotide, as well as data derived from genetically engineered mouse models, provide strong evidence that although GLP-1 retains its physiologic role, it is not the cause of the amelioration of glucose tolerance or sustained weight loss after Roux-en-Y gastric bypass or sleeve gastrectomy. It is unlikely that "medical metabolic surgery" will be based on a single component. Importantly, the scrutiny of GLP-1 as candidate has taught us studies beyond association are required to thoroughly assess whether any of the additionally proposed mediators should be part of the cocktail of factors that could medically mimic metabolic surgery. Topics: Animals; Blood Glucose; Caloric Restriction; Diabetes Mellitus, Type 2; Disease Models, Animal; Gastrectomy; Gastric Bypass; Glucagon-Like Peptide 1; Homeostasis; Humans; Mice; Mice, Knockout; Weight Loss | 2016 |
[Impact of glucagon-like peptide-1 receptor agonists on nasopharyngitis and upper respiratory tract infection among patients with type 2 diabetes: a network meta-analysis].
To systematically review the effects of glucagon-like peptide-1 receptor agonists (GLP-1RAs) on two common respiratory system adverse events (RSAE: nasopharyngitis and upper respiratory tract infection) among type 2 diabetes (T2DM).. Medline, Embase, Clinical trials and Cochrane library were searched from inception through May 2015 to identify randomized clinical trials(RCTs) assessed safety of GLP-1RAs versus placebo or other anti-diabetic drugs in T2DM. Network meta-analysis within a Bayesian framework was performed to calculate odds ratios for the incidence of RSAE.. In the study, 50 RCTs were included, including 13 treatments: 7 GLP-1RAs (exenatide, exenatide-long-release-agent, liraglutide, lixisenatide, taspoglutide, albiglutide and dulaglutide), placebo and 5 traditional anti-diabetic drugs(insulin, metformin, sulfonylureas, sitagliptin and thiazolidinediones ketones). Compared with insulin, taspoglutide significantly decreased the incidence of nasopharyngitis (OR=0.67, 95%CI: 0.46-0.96). Significant lowering effects on upper respiratory tract infection were found when taspoglutide versus placebo (OR=0.57, 95%CI: 0.34-0.99) and insulin (OR=0.39, 95%CI: 0.23-0.73). The result from the network meta-analysis based on Bayesian theory could be used to rank all the treatments included, which showed that taspoglutide ranked last with minimum risk on nasopharyngitis and upper respiratory tract infection.. Taspoglutide was associated with significantly lowering effect on RSAE. Topics: Bayes Theorem; Diabetes Mellitus, Type 2; Exenatide; Glucagon-Like Peptide 1; Glucagon-Like Peptide-1 Receptor; Glucagon-Like Peptides; Humans; Hypoglycemic Agents; Immunoglobulin Fc Fragments; Insulin; Liraglutide; Metformin; Nasopharyngitis; Peptides; Randomized Controlled Trials as Topic; Recombinant Fusion Proteins; Respiratory Tract Infections; Thiazolidinediones; Venoms | 2016 |
Efficacy of hypoglycemic treatment in type 2 diabetes stratified by age or diagnosed age: a meta-analysis.
To compare the effects of blood glucose lowering regimens in groups of patients categorized by baseline age and diagnosed age.. Placebo-controlled randomized trials in type 2 diabetes patients with a study length ≥12 weeks were included.. A total of 246 trials were included. HbA1c changes from baseline corrected by placebo were comparable in sulfonylurea treatment between older and younger patients' groups (weighted mean difference (WMD), -1.28% vs -0.92%, p > 0.05). Treatment with metformin between groups resulted in a comparable change in HbA1c levels (WMD, -0.97% vs -1.23%, p > 0.05). Treatment with α-glucosidase inhibitor (WMD, -0.68% vs -0.67%, p > 0.05), treatment with thiazolidinedione (WMD, -0.74% vs -1.01%, p > 0.05), treatment with DPP-4 inhibitors (WMD, -0.67% vs -0.67%, p > 0.05), and treatment with SGLT2 inhibitors (WMD, -0.54% vs -0.67%, p > 0.05) between groups also resulted in comparable HbA1c changes. Treatment with GLP-1 analogs between groups in HbA1c changes were also comparable (p > 0.05). Regression analysis indicated that the baseline age or diagnosed age was not associated with the HbA1c changes from baseline.. In each hypoglycemic treatment, the baseline age or diagnosed age was not associated with the HbA1c changes from baseline. Topics: Age Factors; Blood Glucose; Clinical Studies as Topic; Databases, Factual; Diabetes Mellitus, Type 2; Dipeptidyl-Peptidase IV Inhibitors; Glucagon-Like Peptide 1; Glycated Hemoglobin; Glycoside Hydrolase Inhibitors; Humans; Hypoglycemic Agents; Placebo Effect; Regression Analysis; Thiazolidinediones | 2016 |
Increasing GLP-1 Circulating Levels by Bariatric Surgery or by GLP-1 Receptor Agonists Therapy: Why Are the Clinical Consequences so Different?
The "incretin effect" is used to describe the observation that more insulin is secreted after the oral administration of glucose compared to that after the intravenous administration of the same amount of glucose. During the absorption of meals, the gut is thought to regulate insulin secretion by secreting a specific factor that targets pancreatic beta cells. Additional research confirmed this hypothesis with the discovery of two hormones called incretins: gastric inhibitory peptide (GIP) and glucagon-like peptide 1 (GLP-1). During meals, specific cells in the gut (L and K enteroendocrine cells) secrete incretins, causing an increase in the blood concentrations of, respectively, GLP-1 and GIP. Bariatric surgery is now proposed during the therapeutic management of type 2 diabetes in obese or overweight populations. It has been hypothesized that restoration of endogenous GLP-1 secretion after the surgery may contribute to the postsurgical resolution of diabetes. In 2005, the commercialization of GLP-1 receptor agonists gave the possibility to test this hypothesis. A few years later, it is now accepted that GLP-1 receptor agonists and bariatric surgery differently improve type 2 diabetes. These differences between endogenous and exogenous GLP-1 on glucose homeostasis emphasized the dual properties of GLP-1 as a peptide hormone and as a neurotransmitter. Topics: Bariatric Surgery; Diabetes Mellitus, Type 2; Glucagon-Like Peptide 1; Glucagon-Like Peptide-1 Receptor; Humans; Hypoglycemic Agents; Obesity; Treatment Outcome | 2016 |
Insulin degludec + liraglutide: a complementary combination.
The treatment of patients with type 2 diabetes mellitus remains challenging, as it goes beyond adequate glycemic control, in particular addressing weight, blood pressure and other contributors to cardiovascular disease. In addition, the progressive nature of type 2 diabetes mellitus demands the intensification and combination of glucose lowering therapies. In many patients, there is a clinical inertia for the initiation of insulin therapy, leading to failure in reaching glycemic targets in many patients.. Recently a fixed-ratio combination therapy of the basal insulin degludec and the glucagon-like peptide-1 analogue liraglutide has been developed and approved by the EMA. The rationale for this combination, as well as an overview of the published phase III clinical trials (DUAL I,II,V), are covered, highlighting the most important conclusions.. The combination therapy of insulin degludec and liraglutide is an attractive therapeutic strategy in patients with type 2 diabetes mellitus as it gives a robust glycemic control with a low risk for hypoglycemia and less weight gain or even weight loss. The fixed-ratio combination of insulin degludec and liraglutide offers a smart therapeutic strategy in patients with type 2 diabetes mellitus where basal insulin needs to be initiated or intensified. Topics: Animals; Blood Glucose; Blood Pressure; Body Weight; Clinical Trials as Topic; Diabetes Mellitus, Type 2; Drug Combinations; Glucagon-Like Peptide 1; Humans; Hypoglycemia; Hypoglycemic Agents; Insulin, Long-Acting; Liraglutide; Weight Gain | 2016 |
Effect of glucagon-like peptide-1 on major cardiovascular outcomes in patients with type 2 diabetes mellitus: A meta-analysis of randomized controlled trials.
The effect of glucagon-like peptide-1 (GLP-1) treatment in patients with type 2 diabetes mellitus (T2DM) remains controversial. The purpose of this study was to compare the effect of GLP-1 and placebo/conventional antidiabetic agents on cardiovascular risk in T2DM patients. PubMed, EmBase and the Cochrane Library were searched to identify its eligible studies as well as manual searches for the reliability of this study. All eligible trials were performed in T2DM patients who received GLP-1 therapy or placebo/conventional antidiabetic agents. The reported outcomes included major cardiovascular events (MACE), and total mortality. Of 490 identified studies, we included 13 trials reporting data on 11,943 T2DM patients. Overall, the pooled results suggested that GLP-1 therapy has no or little effect on MACE (RR: 0.99; 95% CI: 0.88-1.12; P=0.872) and total mortality (RR: 0.90; 95% CI: 0.70-1.15; P=0.399). Furthermore, sensitivity analysis indicated that GLP-1 was associated with lower incidence of total mortality (RR: 0.28; 95% CI: 0.08-0.93; P=0.037). We concluded that GLP-1 therapy was not associated with MACE and total mortality compared with placebo or antidiabetic agents. Topics: Cardiovascular Diseases; Diabetes Mellitus, Type 2; Global Health; Glucagon-Like Peptide 1; Humans; Incretins; Randomized Controlled Trials as Topic; Reproducibility of Results; Survival Rate | 2016 |
Glucagon-Like Peptide-1 (GLP-1) Receptor Agonists in Cardiac Disorders.
To evaluate the literature about the use of glucagon-like peptide-1 receptor agonists (GLP-1 RAs) in the treatment of cardiac disorders, specifically myocardial infarction (MI) and heart failure (HF).. Searches were conducted in MEDLINE (1946-May 2016) and Excerpta Medica (1980-May 2016) using EMBASE with the search terms glucagon-like peptide 1, exenatide, albiglutide, liraglutide, dulaglutide, myocardial infarction, heart failure, and cardiovascular The references of relevant articles were reviewed to identify additional citations.. Clinical trials were limited to the English language and human trials. In all, 18 trials explored the use of GLP-1 RAs in the treatment of cardiac disorders in patients with and without diabetes mellitus.. Of the 18 trials reviewed, 11 trials studied the impact of GLP-1 RAs in MI. All showed a significant beneficial effect on various cardiac parameters. Favorable outcome improvements included myocardial blood flow, left ventricular (LV) function, and MI size. Seven trials reviewed the use of GLP-1 RAs in the treatment of HF. Three trials showed significant improvements in LV ejection fraction, cardiac index, and peak oxygen consumption.. Limited data suggest that GLP-1 RAs may be effective for the treatment of cardiac disorders in patients with and without diabetes mellitus. These studies suggest that GLP-1 RAs may have potential pleiotropic beneficial effects in patients with cardiovascular disease beyond their role in managing diabetes. These medications may be cardioprotective after a MI but are less promising in HF. Topics: Cardiovascular Diseases; Clinical Trials as Topic; Diabetes Mellitus, Type 2; Exenatide; Glucagon-Like Peptide 1; Glucagon-Like Peptide-1 Receptor; Glucagon-Like Peptides; Humans; Hypoglycemic Agents; Immunoglobulin Fc Fragments; Liraglutide; Peptides; Recombinant Fusion Proteins; Venoms | 2016 |
Effects of various gastrointestinal procedures on β-cell function in obesity and type 2 diabetes.
Bariatric surgery is a gastrointestinal procedure that has emerged as the most effective treatment for weight loss. Roux-en-Y gastric bypass and sleeve gastrectomy are the main procedures currently performed. However, the benefits of bariatric surgery extend beyond weight loss. In fact, improvements in β-cell function occur before clinically meaningful weight loss and contribute to type 2 diabetes mellitus (T2D) remission. Herein, we discuss evidence supporting the efficacy of bariatric surgery for weight loss and improved insulin secretion in patients with and without T2D. The exact mechanism by which bariatric surgery elicits a favorable change in β-cell function remains unclear, but a leading hypothesis is that rerouted nutrient flow to the gut alters enteroendocrine hormone production (e.g., glucagon-like polypeptide 1, polypeptide tyrosine-tyrosine, ghrelin), gut microbiome metabolites (e.g., lipopolysaccharides, short-chain fatty acids), and circulating bile acid changes that favor appetite suppression, metabolic rate, and insulin action. We also highlight the role of adipose-derived factors (e.g., pancreatic fat content, adiponectin) that may have an effect on β-cell function, as well as discuss the clinical determinants of diabetes remission (e.g., age and T2D duration). Taken together, the acute improvements seen with bariatric surgery are weight-independent and likely related to incretin-mediated effects on postprandial glucose metabolism and insulin sensitivity. Over longer periods of time, increases in bile acids, reductions in pancreatic lipid content, and elevated adiponectin levels may also contribute to reduced disease risk. As a result, the gut appears to be a novel target for favorably preventing and treating obesity-related metabolic disorders. Topics: Adiponectin; Adipose Tissue; Bariatric Surgery; Bile Acids and Salts; Caloric Restriction; Cytokines; Diabetes Mellitus, Type 2; Fatty Acids, Volatile; Gastrointestinal Hormones; Gastrointestinal Microbiome; Glucagon-Like Peptide 1; Humans; Insulin; Insulin Secretion; Insulin-Secreting Cells; Obesity, Morbid; Postoperative Period | 2016 |
Mechanisms of surgical control of type 2 diabetes: GLP-1 is the key factor-Maybe.
Bariatric surgery is the most effective treatment for obesity and diabetes. The 2 most commonly performed weight-loss procedures, Roux-en-Y gastric bypass (RYGB) and sleeve gastrectomy, improve glycemic control in patients with type 2 diabetes independent of weight loss. One of the early hypotheses raised to explain the immediate antidiabetic effect of RYGB was that rapid delivery of nutrients from the stomach pouch into the distal small intestine enhances enteroinsular signaling to promote insulin signaling. Given the tenfold increase in postmeal glucagon-like peptide-1 (GLP-1) response compared to unchanged integrated levels of postprandial glucose-dependent insulinotropic peptide after RYGB, enhanced meal-induced insulin secretion after this procedure was thought to be the result of elevated glucose and GLP-1 levels. In this contribution to the larger point-counterpoint debate about the role of GLP-1 after bariatric surgery, most of the focus will be on RYGB. Topics: Blood Glucose; Diabetes Mellitus, Type 2; Gastrectomy; Gastric Bypass; Glucagon-Like Peptide 1; Humans; Hyperinsulinism; Hypoglycemia; Insulin; Insulin Secretion; Peptide Fragments; Postprandial Period; Weight Loss | 2016 |
GLP-1 as a target for therapeutic intervention.
Glucagon-like peptide receptor agonists (GLP-1 RA) have multiple effects, including control of glycaemia via stimulation of insulin and suppression of glucagon secretion and reduction of adiposity by enhancing satiety, so are an attractive therapeutic option in type 2 diabetes management. Five GLP-1 RA are used currently and more are in development. The HbA1c reduction obtained varies from 1 to 2%; they reduce body weight by about 2-3kg when used to treat T2DM, while liraglutide results in greater weight loss at a higher dose and has recently been approved for the management of obesity. GLP-1 RA are usually used in combination with other glucose-lowering drugs, but dual combinations with basal insulin in a single injection have recently become available. The next decade is likely to see the development of more potent and longer lasting agents as well as hybrid molecules with dual or triple actions. Topics: Blood Glucose; Body Weight; Diabetes Mellitus, Type 2; Drug Therapy, Combination; Glucagon-Like Peptide 1; Glucagon-Like Peptide-1 Receptor; Humans; Hypoglycemic Agents; Insulin; Liraglutide; Obesity | 2016 |
Albiglutide: a unique GLP-1 receptor agonist.
Albiglutide is a long acting GLP-1 receptor agonist (GLP-1 RA) administered by weekly injection. Area covered: The pharmacokinetic and pharmacodynamic properties of albiglutide and its clinical effects are discussed. The review encompassed a search of PubMed and a thorough analysis of the European Union and US Food and Drug Administration approval documents. Expert opinion: Albiglutide has a chemical structure quite distinct from that of other marketed GLP-1 RAs. The agent has less gastrointestinal side effects than other comparable GLP-1 RAs and is safe in patients with renal failure. As a sole treatment for diabetes and used with other hypoglycemic agents, it achieves a lowering of HbA1c of up to 1%, less than several competitor GLP-1 RAs. The benefit on weight reduction is minimal compared to other GLP-1 RAs. There exists concern about an imbalance of pancreatitis cases in the approval program as well as injection site reactions which led to discontinuance of therapy in up to 2% of participants. A large long term study now underway will determine if albiglutide, with its lower level of GI intolerance, has a place in the treatment of patients with increased risk of cardiovascular events. Topics: Amino Acid Sequence; Animals; Clinical Trials as Topic; Diabetes Mellitus, Type 2; Glucagon-Like Peptide 1; Glucagon-Like Peptide-1 Receptor; Humans; Hypoglycemic Agents; Recombinant Proteins | 2016 |
EndoBarrier gastrointestinal liner. Delineation of underlying mechanisms and clinical effects.
Bariatric surgery (e.g. Roux-en-Y gastric bypass (RYGB)) has proven the most effective way of achieving sustainable weight losses and remission of type 2 diabetes (T2D). Studies indicate that the effectiveness of RYGB is mediated by an altered gastrointestinal tract anatomy, which in particular favours release of the gut incretin hormone glucagon-like peptide-1 (GLP-1). The EndoBarrier gastrointestinal liner or duodenal-jejunal bypass sleeve (DJBS) is an endoscopic deployable minimally invasive and fully reversible technique designed to mimic the bypass component of the RYGB. Not only GLP-1 is released when nutrients enter the gastrointestinal tract. Cholecystokinin (CCK), secreted from duodenal I cells, elicits gallbladder emptying. Traditionally, bile acids are thought of as essential elements for fat absorption. However, growing evidence suggests that bile acids have additional effects in metabolism. Thus, bile acids appear to increase GLP-1 secretion via activation of the TGR5 receptor on the intestinal L cell. Recently FXR receptors were postulated to contribute to GLP-1 secretion too. Furthermore, metformin has been shown to increase circulating GLP-1 levels but although the exact mechanism is not fully elucidated it may involve metformin-induced inhibition of bile acid reuptake from the small intestines. Small-sized studies reported varying degrees of weight loss and, in some, improvement of glucose metabolism. Therefore, the objectives of this thesis were to collect existing information on the DJBS in order to evaluate clinical efficacy and safety (study I and II). Furthermore, since the endocrine impact of the DJBS is not fully elucidated, and DJBS is expected to mimic RYGB, we investigated postprandial metabolic changes following 26 weeks of DJBS treatment in ten obese subjects with normal glucose tolerance (NGT) and nine matched patients with T2D (study III). Finally, we studied the single and combined effects of CCK induced gallbladder emptying and single-dose metformin on human GLP-1 secretion in ten healthy subjects (study IV). We hypothesized that metformin-induced GLP-1 secretion - at least partly - would be dependent on gallbladder emptying and the presence of bile acids in the gut. DJBS appears to lead to moderate weight losses in obese subjects compared to diet or lifestyle modifications (study II). DJBS had insignificant and small effects (compared to diet) on glycaemic regulation. Adverse events consisted mainly of mild-to-moderate tr Topics: Animals; Bariatric Surgery; Bile Acids and Salts; Cholecystokinin; Diabetes Mellitus, Type 2; Gastric Bypass; Glucagon-Like Peptide 1; Glucagon-Like Peptide 2; Glycated Hemoglobin; Humans; Incretins; Metformin; Obesity; Weight Loss | 2016 |
An update on DPP-4 inhibitors in the management of type 2 diabetes.
DPP-4 inhibitors are a class of compounds used for the treatment of type 2 diabetes. The drugs inhibit the degradation of GLP-1, thus amplifying the incretin effect. They have moderate glycemic efficacy, a low propensity of causing hypoglycaemia and are weight neutral. The drugs are often used as second line therapy after metformin. Areas covered: This review summarizes the available compounds in the market and discusses the novel compounds that are currently under development. Several large cardiovascular outcome trials with some of the compounds have been completed, and their results and implications are considered. Fixed dose combination pills are currently the main focus of research and the contribution of these to the care of patients with diabetes is further discussed. Expert opinion: The DPP-4 inhibitors have been a successful class in drug development for diabetes. Taken orally and available as fixed dose combinations with metformin or with SGLT-2 inhibitors, they have reached a large market share of over 7 billion dollars. Other than retagliptin, it does not appear that any additional compound will be launched soon. Currently, the main focus is on the development of additional fixed dose combinations with SGLT-2 inhibitors, but the success of these combinations remains to be seen. Topics: Animals; Diabetes Mellitus, Type 2; Dipeptidyl-Peptidase IV Inhibitors; Drug Combinations; Drug Design; Glucagon-Like Peptide 1; Humans; Hypoglycemic Agents; Incretins; Metformin; Sodium-Glucose Transporter 2; Sodium-Glucose Transporter 2 Inhibitors | 2016 |
Alogliptin: safety, efficacy, and clinical implications.
Alogliptin is the newest dipeptidyl peptidase 4 (DPP-4) inhibitor approved for the treatment of type 2 diabetes either alone or in combination with other antidiabetic agents. The purpose of this review is to highlight the clinical studies that led to Food and Drug Administration approval of alogliptin and to provide insight into the place in therapy for the management of type 2 diabetes mellitus.. As a DPP-4 inhibitor, alogliptin raises postprandial levels of glucagon-like peptide 1, leading to insulin secretion and glucose homeostasis. When given as monotherapy, alogliptin has the ability to reduce glycoslate hemoglobin A1c (HbA1c) by 0.4% to 1.0%. Combination therapy yielded similar reductions with some variability depending on the agent with which alogliptin was combined. The mean HbA1c reduction seen with alogliptin is relative to the degree of HbA1c elevation at baseline. Alogliptin appears to be weight neutral and is relatively well tolerated with few adverse effects. Furthermore, alogliptin has proven to result in comparable efficacy and tolerability in the elderly as in the younger population.. Alogliptin alone or in combination with other antidiabetic agents has shown a significant reduction in HbA1c while remaining safe and tolerable. The efficacy profile of alogliptin is comparable to other DPP-4 inhibitors. Additional long-term research is necessary with regard to long-standing efficacy and effects on beta-cell function. Topics: Blood Glucose; Body Weight; Diabetes Mellitus, Type 2; Dipeptidyl-Peptidase IV Inhibitors; Drug Therapy, Combination; Glucagon-Like Peptide 1; Glycated Hemoglobin; Humans; Hypoglycemic Agents; Insulin; Piperidines; Randomized Controlled Trials as Topic; Uracil | 2015 |
Should we still be concerned about the potential side effects of glucagon-like peptide-1 receptor agonists on thyroid C cells?
In recent years, numerous novel anti-diabetic drugs have emerged. Among them, glucagon-like peptide-1 receptor (GLP-1R) agonists developed on the basis of the incretin theory are the most popular and surprising. Thus far, the clinical and experimental efficiency and safety data seem to be good. However, questions about the side effects of GLP-1R agonists, especially on thyroid C cells, still remain. In vivo and in vitro rodent experiments have shown the potential risks of GLP-1R agonists on thyroid C cells. However, the effects of GLP-1R agonists in humans, which have only been studied in experiments using untreated thyroid tissues or C-cell lines, are questionable and differ from that in rodents. C-cell abnormalities are not only dependent on GLP-1R, as many other factors also influence the structure and function of thyroid C cells. Furthermore, there is not enough information from patients with diabetes or tissue samples from subjects treated with GLP-1R agonists and related drugs--especially data obtained during the prandial period or from a long-term study. Therefore, it is important to focus on the possible side effects of GLP-1R agonists on thyroid C cells. Topics: Animals; Diabetes Mellitus, Type 2; Glucagon-Like Peptide 1; Glucagon-Like Peptide-1 Receptor; Humans; Hypoglycemic Agents; Receptors, Glucagon; Thyroid Gland | 2015 |
Risk of bone fractures associated with glucagon-like peptide-1 receptor agonists' treatment: a meta-analysis of randomized controlled trials.
Traditional anti-diabetic drugs may have negative or positive effects on risk of bone fractures. Yet the relationship between the new class glucagon-like peptide-1 receptor agonists (GLP-1 RA) and risk of bone fractures has not been established. We performed a meta-analysis including randomized controlled trials (RCT) to study the risk of bone fractures associated with liraglutide or exenatide, compared to placebo or other active drugs. We searched MEDLINE, EMBASE, and clinical trial registration websites for published or unpublished RCTs comparing the effects of liraglutide or exenatide with comparators. Only studies with disclosed bone fracture data were included. Separate pooled analysis was performed for liraglutide or exenatide, respectively, by calculating Mantel-Haenszel odds ratio (MH-OR). 16 RCTs were identified including a total of 11,206 patients. Liraglutide treatment was associated with a significant reduced risk of incident bone fractures (MH-OR=0.38, 95% CI 0.17-0.87); however, exenatide treatment was associated with an elevated risk of incident bone fractures (MH-OR=2.09, 95% CI 1.03-4.21). Publication bias and heterogeneity between studies were not observed. Our study demonstrated a divergent risk of bone fractures associated with different GLP-1 RA treatments. The current findings need to be confirmed by future well-designed prospective or RCT studies. Topics: Diabetes Mellitus, Type 2; Exenatide; Fractures, Bone; Glucagon-Like Peptide 1; Glucagon-Like Peptide-1 Receptor; Humans; Hypoglycemic Agents; Liraglutide; Peptides; Randomized Controlled Trials as Topic; Receptors, Glucagon; Risk; Venoms | 2015 |
Selective targeting of glucagon-like peptide-1 signalling as a novel therapeutic approach for cardiovascular disease in diabetes.
Glucagon-like peptide-1 (GLP-1) is an incretin hormone whose glucose-dependent insulinotropic actions have been harnessed as a novel therapy for glycaemic control in type 2 diabetes. Although it has been known for some time that the GLP-1 receptor is expressed in the CVS where it mediates important physiological actions, it is only recently that specific cardiovascular effects of GLP-1 in the setting of diabetes have been described. GLP-1 confers indirect benefits in cardiovascular disease (CVD) under both normal and hyperglycaemic conditions via reducing established risk factors, such as hypertension, dyslipidaemia and obesity, which are markedly increased in diabetes. Emerging evidence indicates that GLP-1 also exerts direct effects on specific aspects of diabetic CVD, such as endothelial dysfunction, inflammation, angiogenesis and adverse cardiac remodelling. However, the majority of studies have employed experimental models of diabetic CVD and information on the effects of GLP-1 in the clinical setting is limited, although several large-scale trials are ongoing. It is clearly important to gain a detailed knowledge of the cardiovascular actions of GLP-1 in diabetes given the large number of patients currently receiving GLP-1-based therapies. This review will therefore discuss current understanding of the effects of GLP-1 on both cardiovascular risk factors in diabetes and direct actions on the heart and vasculature in this setting and the evidence implicating specific targeting of GLP-1 as a novel therapy for CVD in diabetes. Topics: Cardiovascular Diseases; Diabetes Mellitus, Type 2; Glucagon-Like Peptide 1; Humans; Hypoglycemic Agents; Risk Factors; Signal Transduction | 2015 |
A multiplicity of targets: evaluating composite endpoint studies of the GLP-1 receptor agonists in type 2 diabetes.
Current type 2 diabetes (T2D) treatment guidelines include weight maintenance or loss, avoidance of hypoglycemia, and targets for blood pressure and circulating lipids, in addition to glycemic control. Increasingly, clinical trials and meta-analyses employ composite endpoints to capture the net clinical benefit of a given T2D intervention. Glucagon-like peptide-1 receptor agonists (GLP-1 RAs) represent a new class of injected antihyperglycemic agents that may be well suited to reaching many of these targets among patients failing on metformin monotherapy.. Using MEDLINE, Embase and Google Scholar, studies were sought that employed composite endpoints and that reported outcomes with exenatide and/or liraglutide. Bibliographies of relevant review articles were consulted to search for additional reports.. Many trials have used the combination of HbA1c <7%, no weight gain and no hypoglycemic episodes as the composite endpoint in evaluating T2D therapies; however, at least 15 other distinct composite endpoints have been reported. Findings were relatively consistent across studies, regardless of how the composite endpoint was defined. Specifically, the GLP-1 RAs appear to be superior to other agents in their efficacy in providing T2D patients failing on metformin with a net clinical benefit, which can include avoidance of hyperglycemia and maintenance or improvement in body weight.. Use of composite endpoints represents an important advance in T2D. While no single such endpoint has achieved dominance in the field, widely used composite endpoints capture efficacy in glycemic control as well as safety and effects on markers of cardiovascular risk. Topics: Blood Glucose; Diabetes Mellitus, Type 2; Exenatide; Glucagon-Like Peptide 1; Glucagon-Like Peptide-1 Receptor; Glycated Hemoglobin; Humans; Hypoglycemic Agents; Liraglutide; Outcome Assessment, Health Care; Peptides; Receptors, Glucagon; Venoms | 2015 |
Beta cell connectivity in pancreatic islets: a type 2 diabetes target?
Beta cell connectivity describes the phenomenon whereby the islet context improves insulin secretion by providing a three-dimensional platform for intercellular signaling processes. Thus, the precise flow of information through homotypically interconnected beta cells leads to the large-scale organization of hormone release activities, influencing cell responses to glucose and other secretagogues. Although a phenomenon whose importance has arguably been underappreciated in islet biology until recently, a growing number of studies suggest that such cell-cell communication is a fundamental property of this micro-organ. Hence, connectivity may plausibly be targeted by both environmental and genetic factors in type 2 diabetes mellitus (T2DM) to perturb normal beta cell function and insulin release. Here, we review the mechanisms that contribute to beta cell connectivity, discuss how these may fail during T2DM, and examine approaches to restore insulin secretion by boosting cell communication. Topics: Animals; Cell Communication; Diabetes Mellitus, Type 2; Gap Junctions; Glucagon-Like Peptide 1; Glucose; Humans; Insulin; Insulin Secretion; Insulin-Secreting Cells; Islets of Langerhans; Models, Biological; Paracrine Communication | 2015 |
Adverse drug reactions associated with the use of liraglutide in patients with type 2 diabetes--focus on pancreatitis and pancreas cancer.
The glucagon-like peptide-1 (GLP-1) receptor agonist, liraglutide , is a widely used drug for the treatment of type 2 diabetes. Liraglutide is one of several incretin-based agents that have been suggested to be associated with pancreatitis and pancreas cancer. The suspicion accelerated after publication of an autopsy study claiming increased incidences of several pathological changes in pancreata from patients with diabetes treated with incretin-based drugs.. The aim of the present review is to give an overview of the pharmacology of liraglutide and provide a review of adverse reactions associated with liraglutide with a focus on the risk of pancreatitis and pancreas cancer.. When comprehensively reviewing the available literature, no clear and significant associations between liraglutide and pancreatitis and/or pancreas cancer seem evident. However, a recently published analysis suggests a trend toward a slightly elevated risk of pancreatitis with GLP-1 receptor agonists (including liraglutide), which may become statistical significant as more data become available. Well-established side effects are of gastrointestinal origin, typical mild-to-moderate and of transient character. The risk of hypoglycemia associated with liraglutide treatment is low. Topics: Diabetes Mellitus, Type 2; Glucagon-Like Peptide 1; Glucagon-Like Peptide-1 Receptor; Humans; Hypoglycemic Agents; Liraglutide; Pancreatic Neoplasms; Pancreatitis; Receptors, Glucagon | 2015 |
How to fight obesity with antidiabetic drugs: targeting gut or kidney?
The increased prevalence of type 2 diabetes follows the increased prevalence of obesity. Both diseases share common pathophysiological pathways; obesity is in most cases the first step, whereas diabetes is the second one. Weight gain occurs during the treatment of diabetes with drugs causing endogenous or exogenous hyperinsulinemia. Insulin and sulfonylurea are making patients more obese and more insulin resistant. Glucagon-like peptide-1 receptor agonists (GLP-1 agonists) and sodium/glucose cotransporter 2 inhibitors (SGLT2 inhibitors) are antidiabetic drugs with weight loss property. GLP-1 agonists mimic an incretin action. They release insulin after a meal during hyperglycemia and suppress glucagon. The weight loss effect is a consequence of central action increased satiety. Some of GLP-1 agonists weight loss is a result of decelerated gastric emptying rate. SGLT2 inhibitors block sodium glucose cotransporter in proximal tubule brush border and produce glucose excretion with urinary loss. Urinary glucose leak results in calories and weight loss. Even a modest weight loss has positive outcome on metabolic features of diabetic patient; such drugs have important role in treatment of type 2 diabetic patients. However, there are some still unresolved questions. The weight loss they produce is modest. Those drugs are expensive and not available to many diabetic patients, they are significantly more expensive compared to "traditional" hypoglycemic drugs. The hypoglycemic endpoint of GLP-1 agonists and SGLT2 inhibitors often requires adding another antidiabetic drug. The most radical and most effective therapy of type 2 diabetes and obesity is bariatric surgery having significant number of diabetes remission. Topics: Anti-Obesity Agents; Bariatric Surgery; Biological Transport; Clinical Trials as Topic; Comorbidity; Diabetes Mellitus, Type 1; Diabetes Mellitus, Type 2; Drug Therapy, Combination; Exenatide; Gastric Emptying; Glucagon; Glucagon-Like Peptide 1; Glucose; Glycosuria; Humans; Hyperglycemia; Hypoglycemic Agents; Insulin; Insulin Resistance; Insulin Secretion; Islets of Langerhans; Kidney Tubules, Proximal; Microvilli; Multicenter Studies as Topic; Obesity; Peptides; Sodium-Glucose Transporter 2; Sodium-Glucose Transporter 2 Inhibitors; Venoms; Weight Loss | 2015 |
Gastrointestinal adverse events of glucagon-like peptide-1 receptor agonists in patients with type 2 diabetes: a systematic review and network meta-analysis.
Glucagon-like peptide-1 receptor agonists (GLP-1 RAs) are a new class of drugs used in the treatment of type 2 diabetes mellitus (T2DM). Gastrointestinal (GI) adverse events (AEs) are the most frequently reported treatment-related AEs for GLP-1 RAs. We aim to evaluate the effect of GLP-1 RAs on the incidence of GI AEs of T2DM.. The overview of the GI events of GLP-1 RAs has been performed on relevant publications through the literature search, such as MEDLINE, EMBASE, Cochrane Library, and ClinicalTrials.gov The manufacturer was contacted regarding unpublished data. We analyzed direct and indirect comparisons of different treatments using Bayesian network meta-analysis.. Taspoglutide 30 mg once weekly (TAS30QW) and lixisenatide 30 μg twice daily (LIX30BID) were ranked the top two drugs in terms of GI AEs versus placebo. The odds ratios of nausea and vomiting for TAS30QW were 11.8 (95% confidence interval [CI], 2.89, 46.9) and 51.7 (95% CI, 7.07, 415), respectively, and that of diarrhea was 4.93 (95% CI, 1.75, 14.7) for LIX30BID.. Our study found all GLP-1 RA dose regimens significantly increased the incidence of GI AEs, compared with placebo or conventional treatment. The occurrence of GI AEs was different with diverse dose regimens of GLP-1 RAs. TAS30QW had the maximum probability to occur nausea and vomiting, whereas LIX30BID had the maximum probability to cause development of diarrhea versus other treatments. Topics: Diabetes Mellitus, Type 2; Diarrhea; Glucagon-Like Peptide 1; Glucagon-Like Peptide-1 Receptor; Humans; Incretins; Middle Aged; Nausea; Peptides; Receptors, Glucagon; Vomiting | 2015 |
Addressing unmet medical needs in type 2 diabetes: a narrative review of drugs under development.
The global burden of type 2 diabetes is increasing worldwide, and successful treatment of this disease needs constant provision of new drugs. Twelve classes of antidiabetic drugs are currently available, and many new drugs are under clinical development. These include compounds with known mechanisms of action but unique properties, such as once-weekly DPP4 inhibitors or oral insulin. They also include drugs with new mechanisms of action, the focus of this review. Most of these compounds are in Phase 1 and 2, with only a small number having made it to Phase 3 at this time. The new drug classes described include PPAR agonists/modulators, glucokinase activators, glucagon receptor antagonists, anti-inflammatory compounds, G-protein coupled receptor agonists, gastrointestinal peptide agonists other than GLP-1, apical sodium-dependent bile acid transporter (ASBT) inhibitors, SGLT1 and dual SGLT1/SGLT2 inhibitors, and 11beta- HSD1 inhibitors. Topics: Blood Glucose; Diabetes Mellitus, Type 2; Dipeptidyl-Peptidase IV Inhibitors; Dose-Response Relationship, Drug; Drug Design; Glucagon-Like Peptide 1; Humans; Hypoglycemic Agents; Insulin; Needs Assessment; Peroxisome Proliferator-Activated Receptors | 2015 |
Dulaglutide: the newest GLP-1 receptor agonist for the management of type 2 diabetes.
To review the pharmacology, pharmacokinetics, safety, and efficacy of the glucagon-like peptide-1 receptor agonist (GLP-1 RA), dulaglutide, in the treatment of type 2 diabetes mellitus (T2D).. A PubMed search was completed to identify publications from 1947 to October 2014 using the search terms dulaglutide and LY2189265. References were reviewed to identify additional resources.. Articles were included if they evaluated the pharmacology, pharmacokinetics, safety, or efficacy of dulaglutide.. Dulaglutide reduces both glycosylated hemoglobin (A1C) and weight by stimulating insulin secretion and suppressing glucagon in a glucose-dependent manner, delaying gastric emptying, and promoting satiety. Dulaglutide consists of 2 GLP-1 analogues that have been modified to make it a long-acting, once-weekly agent. Dulaglutide has been studied as monotherapy and in combination with metformin, glimepiride, pioglitazone, and insulin lispro. It has demonstrated superior A1C reduction compared with placebo, metformin, insulin glargine, sitagliptin, and twice-daily exenatide. It demonstrated noninferiority in A1C reduction to liraglutide. Dulaglutide changed A1C by -0.78% to -1.51%, and it changed weight by -0.35 kg to -3.03 kg. The most common adverse effects in clinical studies were nausea, vomiting, and diarrhea.. Dulaglutide is the fifth GLP-1 RA approved for T2D in the United States. It is an attractive option because it is dosed once-weekly, provides A1C lowering similar to liraglutide, weight reduction similar to exenatide, and has an adverse effect profile similar to exenatide and liraglutide. Topics: Diabetes Mellitus, Type 2; Exenatide; Glucagon-Like Peptide 1; Glucagon-Like Peptide-1 Receptor; Glucagon-Like Peptides; Glycated Hemoglobin; Humans; Hypoglycemic Agents; Immunoglobulin Fc Fragments; Insulin; Liraglutide; Metformin; Peptides; Pioglitazone; Pyrazines; Receptors, Glucagon; Recombinant Fusion Proteins; Sitagliptin Phosphate; Thiazolidinediones; Triazoles; Venoms | 2015 |
Emerging new therapies for the treatment of type 2 diabetes mellitus: glucagon-like peptide-1 receptor agonists.
The goal of this article was to review the safety, efficacy, and potential for utilization of the newly approved once-weekly glucagon-like peptide-1 (GLP-1) receptor agonists in the treatment of type 2 diabetes.. Published articles for Phase III trials were found by performing a MEDLINE search using the search terms exenatide, exenatide once weekly, DURATION, albiglutide, and HARMONY as key terms. Search results were restricted by using filters to include clinical trials in humans. A search of relevant diabetes journals (including Diabetes Care and Diabetologia) was also performed to find abstracts for studies that did not have complete published articles at the time of this review.. Exenatide once weekly reduced glycosylated hemoglobin (HbA1c) by -1.0% to -2.0% when used as monotherapy and add-on therapy; it also provided significant weight loss ranging from 2 to 4 kg and maintained a relatively low risk of hypoglycemia. Albiglutide was able to reduce glycosylated hemoglobin levels between -0.5% and -0.84% when used as monotherapy and in combination with other antidiabetic medications. The newest once-weekly GLP-1 receptor agonist, dulaglutide, reduced glycosylated hemoglobin levels between -0.78% and -1.51% and demonstrated noninferiority to once-daily liraglutide.. The GLP-1 receptor agonists have proven efficacy in the treatment of type 2 diabetes and may provide patients with additional nonglycemic benefits, including significant weight loss and decreased systolic blood pressure. The newer once-weekly formulations are more convenient than the BID and once-daily medications, which could improve adherence and may be more attractive to providers and patients. Topics: Adult; Clinical Trials, Phase III as Topic; Diabetes Mellitus, Type 2; Drug Administration Schedule; Exenatide; Glucagon-Like Peptide 1; Glucagon-Like Peptide-1 Receptor; Glucagon-Like Peptides; Glycated Hemoglobin; Humans; Hypoglycemia; Hypoglycemic Agents; Immunoglobulin Fc Fragments; Liraglutide; Middle Aged; Peptides; Randomized Controlled Trials as Topic; Receptors, Glucagon; Recombinant Fusion Proteins; Venoms | 2015 |
Effects of glucagon-like peptide-1 receptor agonists on weight loss in patients with type 2 diabetes: a systematic review and network meta-analysis.
To evaluate the effectiveness of glucagon-like peptide-1 receptor agonists (GLP-1 RAs) on weight reduction in patients with Type 2 diabetes mellitus (Type 2 DM), a network meta-analysis was conducted. MEDLINE, EMBASE, Cochrane Library, and ClinicalTrials.gov were searched from 1950 to October 2013. Randomized controlled trials (RCTs) involving GLP-1 RAs were included if they provided information on body weight. A total of 51 RCTs were included and 17521 participants were enrolled. The mean duration of 51 RCTs was 31 weeks. Exenatide 10 μg twice daily (EX10BID) reduced weight compared with exenatide 5 μg twice daily (EX5BID), liraglutide 0.6 mg once daily (LIR0.6QD), liraglutide-1.2 mg once daily (LIR1.2QD), and placebo treatment, with mean differences of -1.07 kg (95% CI: -2.41, -0.02), -2.38 kg (95% CI: -3.71, -1.06), -1.62 kg (95% CI: -2.79, -0.43), and -1.92 kg (95% CI: -2.61, -1.24), respectively. Reductions of weight treated with liraglutide-1.8 mg once daily (LIR1.8QD) reach statistical significance (-1.43 kg (95% CI: -2.73, -0.15)) versus LIR1.2QD and (-0.98 kg (95% CI: -1.94, -0.02)) versus placebo. Network meta-analysis found that EX10BID, LIR1.8QD, and EX2QW obtained a higher proportion of patients with weight loss than other traditional hypoglycemic agents. Our results suggest GLP-1 RAs are promising candidates for weight control in comparison with traditional hypoglycemic drugs, and EX10BID, LIR1.8QD, and EX2QW rank the top three drugs. Topics: Diabetes Mellitus, Type 2; Drug Administration Schedule; Exenatide; Glucagon-Like Peptide 1; Glucagon-Like Peptide-1 Receptor; Humans; Hypoglycemic Agents; Insulin; Liraglutide; Obesity; Overweight; Peptides; Randomized Controlled Trials as Topic; Receptors, Glucagon; Venoms; Weight Loss | 2015 |
Possible abilities of dietary factors to prevent and treat diabetes via the stimulation of glucagon-like peptide-1 secretion.
There is a pressing need for countermeasures against diabetes, which has increased in incidence, becoming a global issue. Glucagon-like peptide-1 (GLP-1), a molecule secreted in enteroendocrine L cells in the lower small and large intestines, is thought to be one of the most important molecular targets for the prevention and treatment of diabetes. There has been increasing interest in the possible ability of dietary factors to treat diabetes via modulating GLP-1 secretion. There is thought to be a close relationship between incretin and diet, and the purported best approach for using dietary factors to increase GLP-1 activity is promotion of secretion of endogenous GLP-1. It have been reported that nutrients as well as various non-nutrient dietary factors can function as GLP-1 secretogogues. Here, we present our findings on the GLP-1 secretion-stimulating functions of two dietary factors, curcumin and extract of edible sweet potato leaves, which contain caffeoylquinic acid derivatives. However, it is necessary to reveal in greater detail the stimulation of GLP-1 secretion by dietary factors for preventing and treating diabetes. It is desirable to clarify the exact GLP-1 secretory pathway, the effect of metabolites derived from dietary factors in gut lumen, and the relationship between incretin and meal. Topics: Amino Acids; Curcumin; Diabetes Mellitus, Type 2; Diet; Dietary Supplements; Glucagon-Like Peptide 1; Humans; Ipomoea batatas; Lipid Metabolism; Molecular Targeted Therapy | 2015 |
Cardiometabolic Effects of a New Class of Antidiabetic Agents.
Within the past decade, many new classes of drugs have received approval from the US Food and Drug Administration for treatment of type 2 diabetes mellitus, including glucagon-like peptide-1agonists, dipeptidyl peptidase-4 inhibitors, and the sodium-glucose cotransporter-2 inhibitors. Many trials have been performed, and several more are currently ongoing to evaluate these drugs. This review addresses the broad therapeutic and pleiotropic effects of these drugs. The review also discusses the role of these drugs in the treatment paradigm for type 2 diabetes and identifies patients who would be suitable candidates for treatment with these drugs.. In this comprehensive evidence-based review, the following databases were searched from 1990 to the present: PubMed/MEDLINE, Scopus, CINAHL, ClinicalTrials.gov, the World Health Organization International Clinical Trials Registry Portal, and the American Diabetes Association and European Association for the Study of Diabetes abstract databases. Randomized clinical trials (RCTs) were only included for the main therapeutic and cardiovascular (CV) effects of these drug classes. For pleiotropic effects, RCTs were included unless no RCTs exist, in which case other studies as specified in the detailed Methods section were included.. All 3 drug classes are effective in lowering hemoglobin A1c between 0.4% and 1.4%, depending on the drug class and population selected. These drug classes have beneficial effects on CV risk factors, such as weight, lipids, and blood pressure, in addition to lowering blood glucose levels. The CV tolerability of some drugs has been evaluated and found to be neutral; however, most trials are currently ongoing to assess CV tolerability. There are no concrete guidelines to determine where these drugs fit in the diabetes management paradigm, and there are ongoing trials to determine the best combination drug with metformin.. These 3 drug classes will potentially increase the armamentarium against hyperglycemia. However, the specific combinations with other antidiabetic drugs and populations that will best benefit from these drugs are still being tested. Future research is also being conducted on the use of glucagon-like peptide-1 receptor agonists and sodium-glucose cotransporter-2 inhibitors in patients with type 1 diabetes. Topics: Blood Glucose; Blood Pressure; Body Weight; Diabetes Mellitus, Type 2; Dipeptidyl-Peptidase IV Inhibitors; Glucagon-Like Peptide 1; Glycated Hemoglobin; Humans; Hypoglycemic Agents; Sodium-Glucose Transporter 2 Inhibitors | 2015 |
Albiglutide: a review of its use in patients with type 2 diabetes mellitus.
Albiglutide (Eperzan(®), Tanzeum(®)), administered subcutaneously once weekly, is a glucagon-like peptide (GLP)-1 receptor agonist approved for the treatment of type 2 diabetes mellitus in several countries. Albiglutide has a longer half-life than native GLP-1, since it is resistant to degradation by the dipeptidyl peptidase-4 enzyme. As an incretin mimetic, albiglutide enhances glucose-dependent insulin secretion, suppresses inappropriate glucagon secretion, delays gastric emptying and reduces food intake. Several phase III clinical trials have demonstrated the efficacy of albiglutide in terms of improving glycaemic control in patients with inadequately controlled type 2 diabetes, including its use as monotherapy or add-on therapy to other antidiabetic agents (e.g. metformin, sulfonylureas, thiazolidinediones and insulins). In addition to improving glycaemic control, albiglutide had beneficial effects on bodyweight. These improvements in glycaemic control and reductions in bodyweight were maintained during long-term treatment (up to 3 years). Albiglutide was generally well tolerated in clinical trials, with mild to moderate gastrointestinal adverse events seen most commonly. Albiglutide has a convenient once-weekly administration regimen and a low risk of hypoglycaemia (except when used in combination with agents that may be associated with hypoglycaemia, such as sulfonylureas or insulin). Thus, albiglutide is an effective and generally well tolerated treatment option for patients with inadequately controlled type 2 diabetes. Topics: Diabetes Mellitus, Type 2; Glucagon-Like Peptide 1; Humans; Hypoglycemic Agents | 2015 |
The effects of glucose-lowering therapies on diabetic kidney disease.
Chronic hyperglycemia and its associated metabolic products are key factors responsible for the development and progression of diabetic chronic kidney disease (CKD). Endocrinologists are tasked with detection and management of early CKD before patients need referral to a nephrologist for advanced CKD or dialysis evaluation. Primary care physicians are increasingly becoming aware of the importance of managing hyperglycemia to prevent or delay progression of CKD. Glycemic control is an integral part of preventing or slowing the advancement of CKD in patients with diabetes; however, not all glucose-lowering agents are suitable for this patient population. The availability of the latest information on treatment options may enable physicians to thwart advancement of serious renal complication in patients suffering from diabetes. This review presents clinical data that shed light on the risk/benefit profiles of three relatively new antidiabetes drug classes, the dipeptidyl peptidase-4 inhibitors, glucagon-like peptide-1 analogs, and sodium glucose co-transporter 2 inhibitors, particularly for patients with diabetic CKD, and summarizes the effects of these therapies on renal outcomes and glycemic control for endocrinologists and primary care physicians. Current recommendations for screening and diagnosis of CKD in patients with diabetes are also discussed. Topics: Antihypertensive Agents; Diabetes Mellitus, Type 2; Diabetic Nephropathies; Dipeptidyl-Peptidase IV Inhibitors; Disease Progression; Glucagon-Like Peptide 1; Glycated Hemoglobin; Humans; Hypoglycemic Agents; Incretins; Renal Insufficiency, Chronic; Sodium-Glucose Transporter 2 Inhibitors | 2015 |
First fixed-ratio combination of insulin degludec and liraglutide for the treatment of type 2 diabetes.
When oral hypoglycemic agents do not successfully suppress hyperglycemia, the traditional approach has been to add insulin injections. With the coming of glucagon-like peptide 1 (GLP-1) receptor agonists carrying the benefits of weight loss and reduced risk of hypoglycemia, it has been suggested that GLP-1 agents should be used instead. There is equivalent lowering of HbA1c with either treatment. Insulin therapy is associated with hypoglycemia and weight gain while GLP-1 receptor agonists promote weight loss. Gastrointestinal (GI) intolerance is the chief obstacle to GLP-1 treatment. The combined use of basal insulin and GLP-1 receptor agonists results in improved glycemic control and mitigates weight gain. The recent approval of insulin degludec/liraglutide administered in a fixed ratio combination is unique not simply for the additive benefits of the two agents, but because it now permits adjustable dosing of liraglutide together with insulin, providing better glucose control than with either agent alone at lower dose levels. Lower dosage of insulin degludec reduces the risk of hypoglycemia. Liraglutide combats the weight gain that accompanies the introduction of insulin therapy, and a reduced dose of liraglutide induces less GI intolerance. This first combined basal insulin-GLP-1 receptor agonist combination represents a conceptual advance in the treatment of insulin-requiring type 2 diabetes. Topics: Clinical Trials as Topic; Diabetes Mellitus, Type 2; Drug Combinations; Drug Discovery; Glucagon-Like Peptide 1; Humans; Hypoglycemic Agents; Insulin, Long-Acting; Liraglutide; Treatment Outcome | 2015 |
Should we be concerned about thyroid cancer in patients taking glucagon-like peptide 1 receptor agonists?
Topics: Animals; Blood Glucose; Contraindications; Diabetes Mellitus, Experimental; Diabetes Mellitus, Type 2; Glucagon-Like Peptide 1; Humans; Hypoglycemic Agents; Metformin; Thyroid Neoplasms | 2015 |
GLP-1 receptor agonists: Nonglycemic clinical effects in weight loss and beyond.
Glucagon-like peptide-1 (GLP-1) receptor agonists are indicated for treatment of type 2 diabetes since they mimic the actions of native GLP-1 on pancreatic islet cells, stimulating insulin release, while inhibiting glucagon release, in a glucose-dependent manner. The observation of weight loss has led to exploration of their potential as antiobesity agents, with liraglutide 3.0 mg day(-1) approved for weight management in the US on December 23, 2014, and in the EU on March 23, 2015. This review examines the potential nonglycemic effects of GLP-1 receptor agonists.. A literature search was conducted to identify preclinical and clinical evidence on nonglycemic effects of GLP-1 receptor agonists.. GLP-1 receptors are distributed widely in a number of tissues in humans, and their effects are not limited to the well-recognized effects on glycemia. Nonglycemic effects include weight loss, which is perhaps the most widely recognized nonglycemic effect. In addition, effects on the cardiovascular, neurologic, and renal systems and on taste perception may occur independently of weight loss.. GLP-1 receptor agonists may provide other nonglycemic clinical effects besides weight loss. Understanding these effects is important for prescribers in using GLP-1 receptor agonists for diabetic patients, but also if approved for chronic weight management. Topics: Anti-Obesity Agents; Blood Glucose; Cardiovascular System; Diabetes Mellitus, Type 2; Female; Glucagon-Like Peptide 1; Glucagon-Like Peptide-1 Receptor; Humans; Hypoglycemic Agents; Insulin; Male; Receptors, Glucagon; Weight Loss | 2015 |
Intestinal nutrient sensing and blood glucose control.
Nutrient-specific sensor systems in enteroendocrine cells detect intestinal contents and cause gut hormone release upon activation. Among these peptide hormones, the incretins glucose-dependent insulinotropic polypeptide and glucagon-like peptide 1 are of particular interest by their role in glucose homeostasis, metabolic control and for proper ß-cell function. This review focuses on intestinal nutrient-sensing processes and their role in health and disease.. All macronutrients, respectively, their digestion products can cause incretin release by targeting specific sensors. Luminal glucose is the strongest stimulant for incretin release with the Na-dependent glucose transporter as the prime sensor. For peptides, the H-dependent peptide transporter together with calcium-sensing-receptor act as a sensing system. That transporters can function as nutrient-sensing 'transceptors' is conceptually new as G-protein coupled receptors so far were thought to be the sensing entities. This still holds true for GPR40 and GPR120 as sensors for medium/long-chain fatty acids and GPR41 and GPR43 for microbiota-derived short-chain fatty acids. Synthetic agonists for these receptors show impressive effects on glucagon-like peptide 1 output and glycemic control. Moreover, the remarkable and immediate antidiabetic effects of bariatric surgery/gastric bypass put intestinal nutrient sensing into focus of new strategies for metabolic control.. Targeting the intestinal nutrient-sensing machinery by dietary and/or pharmacological means holds promises in particular for treatment of type 2 diabetes. This interest may help to better understand the nutrient-sensing processes and the involvement of the intestine in overall endocrine, neuronal and metabolic control. Topics: Animals; Bariatric Surgery; Blood Glucose; Diabetes Mellitus, Type 2; Dietary Carbohydrates; Dietary Fiber; Dietary Proteins; Disease Models, Animal; Enteroendocrine Cells; Fatty Acids, Volatile; Gastrointestinal Microbiome; Glucagon-Like Peptide 1; Humans; Incretins; Intestinal Mucosa; Intestines | 2015 |
Heart failure in diabetes: effects of anti-hyperglycaemic drug therapy.
Individuals with diabetes are not only at high risk of developing heart failure but are also at increased risk of dying from it. Fortunately, antiheart failure therapies such as angiotensin-converting-enzyme inhibitors, β blockers and mineralocorticoid-receptor antagonists work similarly well in individuals with diabetes as in individuals without the disease. Response to intensive glycaemic control and the various classes of antihyperglycaemic agent therapy is substantially less well understood. Insulin, for example, induces sodium retention and thiazolidinediones increase the risk of heart failure. The need for new glucose-lowering drugs to show cardiovascular safety has led to the unexpected finding of an increase in the risk of admission to hospital for heart failure in patients treated with the dipeptidylpeptidase-4 (DPP4) inhibitor, saxagliptin, compared with placebo. Here we review the relation between glycaemic control and heart failure risk, focusing on the state of knowledge for the various types of antihyperglycaemic drugs that are used at present. Topics: Adult; Age Distribution; Aged; Aged, 80 and over; Diabetes Mellitus, Type 2; Diabetic Cardiomyopathies; Dipeptidyl-Peptidase IV Inhibitors; Glucagon-Like Peptide 1; Glycoside Hydrolase Inhibitors; Heart Failure; Humans; Hypoglycemic Agents; Insulin; Middle Aged; Observational Studies as Topic; Randomized Controlled Trials as Topic; Sodium-Glucose Transporter 2 Inhibitors; Sulfonylurea Compounds; Thiazolidinediones | 2015 |
[Albiglutide (Eperzan): a new once-weekly agonist of glucagon-like peptide-1 receptors].
Albiglutide (Eperzan) is a new once-weekly agonist of Glucagon-Like Peptide-1 (GLP-1) receptors that is indicated in the treatment of type 2 diabetes. Two doses are available, 30 mg and 50 mg, to be injected subcutaneously once a week. It has been extensively evaluated in the HARMONY programme of eight large randomised controlled trials that were performed at different stages of type 2 diabetes, in comparison with placebo or an active comparator. The endocrine and metabolic effects of albiglutide are similar to those of other GLP-1 receptor agonists: stimulation of insulin secretion (incretin effect) and inhibition of glucagon secretion, both in a glucose-dependent manner, retardation of gastric emptying and increase of satiety. These effects lead to a reduction in glycated haemoglobin (HbA(1c)) levels, combined with a weight reduction. The overall tolerance profile is good. Albiglutide is currently reimbursed in Belgium after failure (HbA(1c) > 7.5%) of and in combination with a dual therapy with metformin and a sulfonylurea as well as in combination with a basal insulin (with or without oral antidiabetic drugs). To avoid hypoglycaemia, a reduction in the dose of sulfonylurea or insulin may be recommended. A once-weekly administration should increase patient's acceptance of injectable therapy and improve compliance. Topics: Diabetes Mellitus, Type 2; Drug Administration Schedule; Drug Interactions; Glucagon-Like Peptide 1; Glucagon-Like Peptide-1 Receptor; Humans; Hypoglycemic Agents; Receptors, Glucagon | 2015 |
Albiglutide: A once-weekly glucagon-like peptide-1 receptor agonist for type 2 diabetes mellitus.
The pharmacology, pharmacokinetics, efficacy, safety, dosage and administration, and place in therapy of the glucagon-like peptide-1 (GLP-1) receptor agonist albiglutide are reviewed.. Albiglutide (Tanzeum, GlaxoSmithKline) is an injectable GLP-1 agonist approved in 2014 for use as an adjunct to diet modification and exercise to improve glycemic control in adults with type 2 diabetes. Albiglutide augments glucose-dependent insulin secretion and slows gastric emptying; it has an elimination half-life of approximately five days, allowing for once-weekly administration. Clinical trials demonstrated mean absolute reductions in glycosylated hemoglobin (HbA1c) values of 0.78-1.55% after 16 weeks of adjunctive therapy with albiglutide. Specific recommendations on albiglutide use have been issued by the American Association of Clinical Endocrinologists (AACE) and the American Diabetes Association (ADA). Studies show that the potential for hypoglycemic episodes with albiglutide use is low. In clinical trials, the most frequently reported adverse events were nausea and diarrhea. The use of albiglutide is contraindicated in patients with a history of pancreatitis and patients with a personal or family history of thyroid cancer.. Albiglutide has been shown to be effective for the management of type 2 diabetes in adults and is recommended (by ADA) as second-line therapy when used in combination with metformin and (by AACE) as first-line monotherapy in patients with an HbA1c concentration of ≤7.5% at treatment initiation. In clinical trials, albiglutide was generally well tolerated by patients, with adverse effects comparable to those seen with other GLP-1 agonists. Topics: Clinical Trials, Phase II as Topic; Clinical Trials, Phase III as Topic; Diabetes Mellitus, Type 2; Glucagon-Like Peptide 1; Glucagon-Like Peptide-1 Receptor; Humans; Hypoglycemic Agents | 2015 |
Impact of Either GLP-1 Agonists or DPP-4 Inhibitors on Pathophysiology of Heart Failure.
Since diabetes mellitus (DM) is the most common cause of heart failure (HF), it is critically important to clarify whether incretin hormones including glucagon-like peptide-1 (GLP-1), which play an important role in blood glucose control, mediate cardioprotection. There are many lines of basic research evidence indicating that GLP-1 improves the pathophysiology of HF: In murine and canine HF models, either GLP-1 analogues or DPP-IV inhibitors improved cardiac functions. The first question that arises is how either GLP-1 analogues or DPP-IV inhibitors mediate cardioprotection. Cardiovascular diseases are tightly linked to impaired glucose tolerance (IGT): IGT is not only one of the causes of cardiovascular events but also the result of HF. Indeed, the treatment of IGT improved HF, showing that one of the mechanisms attributable to DPP-IV inhibitors is related to the improvement of IGT. Intriguingly, either DPP-IV inhibitors or GLP-1 analogues mediate cardioprotection even without IGT, suggesting two possible explanations: One is that GLP-1 analogues directly activate the prosurvival kinases, such as Akt and Erk1/2, and another is that DPP-IV inhibition increases cardioprotective peptides such as BNP and SDF-1α. The next question is whether cardioprotection is translated to clinical medicine. Small scale clinical trials proved their cardioprotective effects; however, several large scale clinical trials have not proved the beneficial effects of DPP-IV inhibitors. Taken together, GLP-1 analogues or DPP-IV inhibitors can mediate cardioprotection, however, what needs to be clarified is who mainly receives their benefits among the patients with cardiovascular diseases and/or DM. Topics: Animals; Blood Glucose; Cardiotonic Agents; Diabetes Mellitus, Type 2; Dipeptidyl-Peptidase IV Inhibitors; Dogs; Glucagon-Like Peptide 1; Heart Failure; Humans; Incretins; Mice; Translational Research, Biomedical | 2015 |
Gut Peptides Are Novel Regulators of Intestinal Lipoprotein Secretion: Experimental and Pharmacological Manipulation of Lipoprotein Metabolism.
Individuals with metabolic syndrome and frank type 2 diabetes are at increased risk of atherosclerotic cardiovascular disease, partially due to the presence of lipid and lipoprotein abnormalities. In these conditions, the liver and intestine overproduce lipoprotein particles, exacerbating the hyperlipidemia of fasting and postprandial states. Incretin-based, antidiabetes therapies (i.e., glucagon-like peptide [GLP]-1 receptor agonists and dipeptidyl peptidase-4 inhibitors) have proven efficacy for the treatment of hyperglycemia. Evidence is accumulating that these agents also improve fasting and postprandial lipemia, the latter more significantly than the former. In contrast, the gut-derived peptide GLP-2, cosecreted from intestinal L cells with GLP-1, has recently been demonstrated to enhance intestinal lipoprotein release. Understanding the roles of these emerging regulators of intestinal lipoprotein secretion may offer new insights into the regulation of intestinal lipoprotein assembly and secretion and provide new opportunities for devising novel strategies to attenuate hyperlipidemia, with the potential for cardiovascular disease reduction. Topics: Animals; Apolipoprotein B-48; Diabetes Mellitus, Type 2; Dipeptidyl-Peptidase IV Inhibitors; Glucagon-Like Peptide 1; Glucagon-Like Peptide 2; Glucagon-Like Peptide-1 Receptor; Humans; Incretins; Intestinal Mucosa; Lipoproteins; Receptors, Glucagon; Triglycerides | 2015 |
Liraglutide for Type 2 diabetes and obesity: a 2015 update.
Subcutaneous liraglutide (Victoza(®), Novo Nordisk) was approved for the treatment of Type 2 diabetes mellitus (T2DM) in Europe in 2009 and in the USA in 2010. In December 2014, liraglutide 3.0 mg was approved by the Food and Drug Administration (FDA) and in March 2015 by the European Medicines Agency (EMA) for the treatment of chronic weight management under the brand name Saxenda(®) Novo Nordisk. Liraglutide causes a glucose-dependent increase in insulin secretion, decreases glucagon secretion and promotes weight loss by inhibiting appetite. Liraglutide probably induces satiety through activation of different areas in the hind brain and possibly by preserving free leptin levels. Recently, liraglutide has been suggested to protect against prediabetes and seems to prevent bone loss by increasing bone formation following diet-induced weight loss in obesity. This article not only covers the major clinical trials evaluating the effects of liraglutide in obesity and T2DM but also provides novel insights into the pharmacological mechanisms of liraglutide. Topics: Appetite Depressants; Diabetes Mellitus, Type 2; Glucagon-Like Peptide 1; Glucagon-Like Peptide-1 Receptor; Humans; Hypoglycemic Agents; Liraglutide; Obesity | 2015 |
Anti-atherosclerotic effects of the glucagon-like peptide-1 (GLP-1) based therapies in patients with type 2 Diabetes Mellitus: A meta-analysis.
This study assessed the effect of GLP-1 based therapies on atherosclerotic markers in type 2 diabetes patients. 31 studies were selected to obtain data after multiple database searches and following inclusion and exclusion criteria. Age and BMI of the participants of longitudinal studies were 59.8 ± 8.3 years and 29.2 ± 5.7 kg/m(2) (Mean±SD). Average duration of GLP-1 based therapies was 20.5 weeks. Percent flow-mediated diameter (%FMD) did not change from baseline significantly but when compared to controls, %FMD increased non-significantly following GLP-1-based therapies (1.65 [-0.89, 4.18]; P = 0.2; REM) in longitudinal studies and increased significantly in cross sectional studies (2.58 [1.68, 3.53]; P < 0.00001). Intima media thickness decreased statistically non-significantly by the GLP-1 based therapies. GLP-1 based therapies led to statistically significant reductions in the serum levels of brain natriuretic peptide (-40.16 [-51.50, -28.81]; P < 0.0001; REM), high sensitivity c-reactive protein (-0.27 [-0.48, -0.07]; P = 0.009), plasminogen activator inhibitor-1 (-12.90 [-25.98, 0.18]; P=0.05), total cholesterol (-5.47 [-9.55, -1.39]; P = 0.009), LDL-cholesterol (-3.70 [-7.39, -0.00]; P = 0.05) and triglycerides (-16.44 [-25.64, -7.23]; P = 0.0005) when mean differences with 95% CI in the changes from baselines were meta-analyzed. In conclusion, GLP-1-based therapies appear to provide beneficial effects against atherosclerosis. More randomized data will be required to arrive at conclusive evidence. Topics: Aged; C-Reactive Protein; Carotid Intima-Media Thickness; Cholesterol; Cholesterol, LDL; Databases, Factual; Diabetes Mellitus, Type 2; Female; Glucagon-Like Peptide 1; Humans; Hypoglycemic Agents; Male; Middle Aged; Natriuretic Peptide, Brain; Plasminogen Activator Inhibitor 1; Triglycerides | 2015 |
Once-weekly glucagon-like peptide 1 receptor agonists.
The once-weekly glucagon-like peptide 1 receptor agonists (QW GLP1RA) represent a major advancement in diabetes pharmaco-therapeutics. This review describes the basic, clinical, and comparative pharmacology of this novel class of drugs. It highlights the clinical placement and posology of these drugs. Topics: Delayed-Action Preparations; Diabetes Mellitus, Type 2; Drug Administration Schedule; Exenatide; Glucagon-Like Peptide 1; Glucagon-Like Peptide-1 Receptor; Glucagon-Like Peptides; Humans; Hypoglycemic Agents; Immunoglobulin Fc Fragments; Incretins; Peptides; Recombinant Fusion Proteins; Venoms | 2015 |
[GLP-1 receptor agonists versus SGLT-2 inhibitors in obese type 2 diabetes patients].
Who never had a type 2 obese diabetic patient, treated by several oral antidiabetic drugs and insulin, with consequent weight gain associated with the therapeutic escalation and uncontrolled diabetes? The arrival of GLP-1 agonists and SGLT-2 inhibitors allows to reevaluate the management of these patients, with their favorable effects on glycemic control, weight and the risk of hypoglycemia and their complementary mechanisms to conventional treatments. The vicious cycle of weight gain and increased need of insulin is limited. The choice between these two molecules must be based on several factors (glycemic target, weight, comorbidities, route of administration, side effects, etc.), and the balanced enthusiasm of these new treatments with the insufficient data regarding their long-term safety and their impact on micro- and macrovascular complications. Topics: Diabetes Mellitus, Type 2; Dipeptidyl-Peptidase IV Inhibitors; Glucagon-Like Peptide 1; Glucagon-Like Peptide-1 Receptor; Humans; Hypoglycemic Agents; Incretins; Obesity; Practice Guidelines as Topic; Receptors, Glucagon; Sodium-Glucose Transporter 2; Sodium-Glucose Transporter 2 Inhibitors | 2015 |
Effects of three injectable antidiabetic agents on glycaemic control, weight change and drop-out in type 2 diabetes suboptimally controlled with metformin and/or a sulfonylurea: A network meta-analysis.
The objective of this review was to assess glucagon-like peptide-1 receptor agonists (GLP-1 RAs), basal insulin, and premixed insulin among participants with type 2 diabetes inadequately controlled with metformin and/or a sulfonylurea.. We searched PubMed, EmBase, and the Cochrane Library to identify eligible randomized controlled trials (RCTs) for a network meta-analysis.. A total of 17 RCTs involving 5874 adult individuals were included. Compared with placebo, all three therapies showed a significant effect on achieving target glycated hemoglobin (HbA1c) (GLP-1 RAs: 31.7%, 95% CI, 24.7-38.6%; premixed insulin: 31.1%, 95% CI, 20.4-41.8%; basal insulin: 26.0%, 95% CI, 16.4-35.7%). However, there was no significant difference between the three therapies. A similar result was found in HbA1c reduction. The use of GLP-1 RAs resulted in significant body weight loss (-3.73 kg, 95% CI, -4.52 to -2.95 kg vs. basal insulin and -5.27 kg, 95% CI, -6.17 to -4.36 kg vs. premixed insulin) but there was a higher drop-out rate of participants. Premixed insulin seemed associated with more severe hypoglycemic episodes.. The three injectables had similar impact on glycemic control but other differentiating features relevant to the management of type 2 diabetes with GLP-1 RAs having the most favorable profile. Topics: Adult; Blood Glucose; Community Networks; Diabetes Mellitus, Type 2; Glucagon-Like Peptide 1; Glycated Hemoglobin; Humans; Hypoglycemia; Hypoglycemic Agents; Injections; Insulin; Male; Metformin; Randomized Controlled Trials as Topic; Sulfonylurea Compounds; Treatment Failure | 2015 |
Cardiovascular safety of albiglutide in the Harmony programme: a meta-analysis.
Albiglutide is a glucagon-like peptide-1 receptor agonist, a new class of drugs used to treat type 2 diabetes. We did a prospective meta-analysis of the cardiovascular safety of albiglutide as stipulated by the US Food and Drug Administration recommendations for the assessment of new treatments for diabetes.. We did a meta-analysis of eight phase 3 trials and one phase 2b trial in which patients were randomly assigned to albiglutide, placebo, or active comparators (glimepiride, insulin glargine, insulin lispro, liraglutide, pioglitazone, or sitagliptin). The safety population included 5107 patients, of whom 2524 took albiglutide (4870 person-years) and 2583 took comparators (5213 person-years). Possible major cardiovascular events were recorded prospectively and adjudicated by an independent endpoint committee masked to treatment allocation. The primary endpoint was a composite of first occurrence of major adverse cardiovascular events (ie, cardiovascular death, non-fatal myocardial infarction, or non-fatal stroke) or hospital admission for unstable angina. Secondary endpoints were major adverse cardiovascular events alone, all-cause mortality, silent myocardial infarction, hospital admission for heart failure, chest pain, other angina, and subdural or extradural haemorrhage. The occurrence of all other adverse events classified by the investigators as cardiovascular events were documented, but these were not adjudicated.. The primary endpoint was not significantly different between albiglutide and all comparators (58 events vs 58 events; hazard ratio [HR] 1·00, 95% CI 0·68-1·49, p=0·0019 for non-inferiority). Major adverse cardiovascular event alone was also not significantly different (52 events vs 53; HR, 0·99; 95% CI, 0·65-1·49). When albiglutide was compared separately with placebo or active comparators, we noted no significant differences. We detected no significant differences in the other secondary endpoints. More patients had atrial fibrillation or atrial flutter in the albiglutide group (35 [1·4%] of 2524 patients; 8·6 events per 1000 patient-years) than in the all-comparators group (16 [0·6%] of 2583 patients; 3·4 events per 1000 patient-years).. Cardiovascular events were not significantly more likely to occur with albiglutide than with all comparators. Because the upper bound of the 95% CI for major adverse cardiovascular event plus hospital admission for unstable angina was greater than 1·3, a dedicated study with a cardiovascular endpoint is underway to confirm the safety of albiglutide.. GlaxoSmithKline. Topics: Aged; Cardiovascular Diseases; Cardiovascular System; Clinical Trials, Phase II as Topic; Clinical Trials, Phase III as Topic; Diabetes Mellitus, Type 2; Female; Glucagon-Like Peptide 1; Humans; Incretins; Male; Middle Aged; Randomized Controlled Trials as Topic | 2015 |
The treatment of type 1 diabetes mellitus with agents approved for type 2 diabetes mellitus.
The management of type 1 diabetes remains a challenge for clinicians. Current practice is to administer insulin analogues to best mimic normal physiological insulin profiles. However, despite our best efforts the majority of individuals with type 1 diabetes continue to suffer from suboptimal glucose control, significant hypoglycemia and microvascular tissue complications of the disease. There is thus a significant unmet need in the treatment of T1DM to obtain better glycemic control.. We discuss the use of α-glucosidase inhibitors, dipeptidyl-peptidase inhibitors, glucagon-like peptide 1 agonists, biguanides, thiazolidinediones and sodium glucose co-transporter 2 inhibitors in individuals with T1DM.. Non-insulin therapies present a unique and exciting adjunctive treatment for individuals with type 1 diabetes. Although data are scarce, the classes of medications discussed help to lower glucose, decrease glycemic excursions and in some cases improve body weight, along with allowing dose reductions in total daily insulin. Glucagon-like peptide 1 agonists and sodium glucose co-transporter 2 inhibitors, in particular, have been demonstrated to provide clinical improvements in individuals with T1DM and we feel their use can be explored in obese, insulin-resistant patients with T1DM, those with frequent and significant glycemic excursions or individuals with persistently elevated hemoglobin A1c. Topics: Biguanides; Diabetes Mellitus, Type 1; Diabetes Mellitus, Type 2; Dipeptidyl-Peptidase IV Inhibitors; Glucagon-Like Peptide 1; Glycated Hemoglobin; Glycoside Hydrolase Inhibitors; Humans; Hypoglycemic Agents; Insulin Resistance; Obesity; Sodium-Glucose Transporter 2 Inhibitors; Thiazolidinediones | 2015 |
Impact of GLP-1 receptor agonists on blood pressure, heart rate and hypertension among patients with type 2 diabetes: A systematic review and network meta-analysis.
To evaluate current evidence of glucagon-like peptide-1 receptor agonists (GLP-1RAs) on blood pressure, heart rate, and hypertension in patients with type 2 diabetes.. Medline, Embase, the Cochrane library, and the website www.clinicaltrials.gov were searched on April 5th, 2014. Randomized-controlled trials with available data were included if they compared GLP-1RAs with placebo and traditional antidiabetic drugs in patients with type 2 diabetes with duration ≥ 12 weeks. Weighted mean difference for blood pressure and heart rate, odds ratio (OR) for hypertension were calculated by random-effect model. Network meta-analysis was performed to supplement direct comparisons.. Sixty trials with 14 treatments were included. Compared with placebo, insulin, and sulfonylureas, GLP-1RAs decreased systolic blood pressure with range from -1.84 mmHg (95% CI: -3.48 to -0.20) to -4.60 mmHg (95% CI: -7.18 to -2.03). Compared with placebo, a reduction in diastolic blood pressure was detected significantly only for exenatide-10 μg-twice-daily (-1.08 mmHg, 95% CI: -1.78 to -0.33). Exenatide (2 mg once weekly), liraglutide 1.2 mg once daily), and liraglutide (1.8 mg once daily) increased heart rate by 3.35 (95% CI: 1.23-5.50), 2.06 (95% CI: 0.43, 3.74), and 2.35 (95% CI: 0.94-3.76) beats/min versus placebo. This effect was evident compared with active control (range: 2.22-3.62). No significant association between incident hypertension and GLP-1RAs was detected, except for the association between exenatide-10 μg-twice-daily and sulfonylureas (OR, 0.40, 95% CI: 0.16, 0.82).. GLP-1RAs were associated with modest reduction on blood pressure, a slight increase in heart rate, yet no significant association with hypertension. Further investigation to explore mechanisms is warranted. Topics: Blood Pressure; Diabetes Mellitus, Type 2; Exenatide; Glucagon-Like Peptide 1; Glucagon-Like Peptide-1 Receptor; Heart Rate; Humans; Hypertension; Hypoglycemic Agents; Insulin; Liraglutide; Peptides; Randomized Controlled Trials as Topic; Sulfonylurea Compounds; Venoms | 2015 |
User's guide to mechanism of action and clinical use of GLP-1 receptor agonists.
Glucagon-like peptide-1 (GLP-1) receptor agonists (GLP-1RAs) are injectable glucose-lowering medications approved for the treatment of adult patients with type 2 diabetes mellitus (T2DM). This article provides practical information to guide primary care physicians on the use of GLP-1RAs in patients with T2DM. Two short-acting (once- or twice-daily administration; exenatide and liraglutide) and three long-acting (weekly administration; albiglutide, dulaglutide and exenatide) GLP-1RAs are currently approved in the US. These drugs provide levels of GLP-1 receptor agonism many times that of endogenous GLP-1. The GLP-1RAs have been shown to significantly improve glycemic parameters and reduce body weight. These agents work by activating GLP-1 receptors in the pancreas, which leads to enhanced insulin release and reduced glucagon release-responses that are both glucose-dependent-with a consequent low risk for hypoglycemia. Effects on GLP-1 receptors in the CNS and the gastrointestinal tract cause reduced appetite and delayed glucose absorption due to slower gastric emptying. The most common adverse effects are gastrointestinal, which are transient and less common with the long-acting drugs. GLP-1RAs are recommended as second-line therapy in combination with metformin, sulfonylureas, thiazolidinediones or basal insulin, providing a means of enhancing glucose control while offsetting the weight gain associated with insulin and some oral agents. GLP-1RAs represent a useful tool that the primary care physician can use to help patients with T2DM achieve their therapeutic goals. Topics: Blood Glucose; Delayed-Action Preparations; Diabetes Mellitus, Type 2; Drug Therapy, Combination; Energy Intake; Gastric Emptying; Glucagon-Like Peptide 1; Glucagon-Like Peptide-1 Receptor; Glycated Hemoglobin; Humans; Hypoglycemic Agents; Incretins; Medication Adherence; Metformin; Pancreas; Primary Health Care; Weight Loss | 2015 |
Efficacy and safety of once-weekly glucagon-like peptide 1 receptor agonists for the management of type 2 diabetes: a systematic review and meta-analysis of randomized controlled trials.
To assess the efficacy and safety of recently approved once-weekly glucagon-like peptide 1 receptor agonists (GLP-1 RAs) in patients with type 2 diabetes.. We conducted a systematic review and meta-analysis of randomized controlled trials comparing any GLP-1 RA licensed for once-weekly dosing (albiglutide, dulaglutide or exenatide extended release) with placebo or other antidiabetic agents. We searched Medline, Embase, the Cochrane Library and grey literature for articles published up to December 2014 and extracted data in duplicate.. In our systematic review we included 33 trials with a total of 16 003 participants. Compared with placebo the change in glycated haemoglobin (HbA1c) concentration was -0.66% [six studies; 95% confidence interval (CI) -1.14 to -0.19; I(2) = 88%] with albiglutide, and -1.18% (seven studies; 95% CI -1.34 to -1.02; I(2) = 65%) with dulaglutide. Based on data from placebo-controlled trials, we did not detect statistically significant weight-sparing benefits for albiglutide or dulaglutide. Compared with other antidiabetic agents, once-weekly GLP-1 RAs outperformed sitagliptin, daily exenatide and insulin glargine in terms of HbA1c-lowering (mean differences -0.40%; 95% CI -0.66 to -0.14; I(2) = 85%, -0.44%; 95% CI -0.58 to -0.29; I(2) = 40% and -0.28; 95% CI -0.45 to -0.10; I(2) = 81%, respectively). The main adverse effects of treatment included gastrointestinal and injection site reactions.. Given their dosing scheme and overall efficacy and safety profile, once-weekly GLP-1 RAs are a convenient therapeutic option for use as add-on to metformin. Topics: Adult; Diabetes Mellitus, Type 2; Drug Administration Schedule; Drug Therapy, Combination; Exenatide; Female; Glucagon-Like Peptide 1; Glucagon-Like Peptides; Glycated Hemoglobin; Humans; Hypoglycemic Agents; Immunoglobulin Fc Fragments; Incretins; Male; Metformin; Peptides; Randomized Controlled Trials as Topic; Recombinant Fusion Proteins; Venoms | 2015 |
GLP-1 Receptor Agonists: Practical Considerations for Clinical Practice.
Type 2 diabetes (T2D) imparts an increased risk of adverse health outcomes in patients unable to achieve glycemic control. Patient education and individualization of treatment are important for effective management of T2D. Glucagon-like peptide-1 receptor agonists (GLP-1RAs) are a class of injectable glucose-lowering agents that lower A1C with added benefits of weight loss and improved cardiovascular risk markers. This review discusses the role of GLP-1RAs currently approved in the United States (exenatide, liraglutide, albiglutide, dulaglutide) for T2D management and characterizes the efficacy and safety profiles of individual GLP-1RAs.. GLP-1RAs are recommended as a preferred add-on agent to existing metformin monotherapy, as first-line therapy if metformin is contraindicated or poorly tolerated, and for use in combination with other oral glucose-lowering agents or basal insulin. Shorter-acting GLP-1RAs (exenatide and liraglutide) offer improved coverage of postprandial hyperglycemia, while longer-acting GLP-1RA formulations (exenatide extended-release, dulaglutide, and albiglutide) further improve fasting plasma glucose, which can result in additional A1C lowering. Reductions in body weight and blood pressure appear similar among individual agents, and small increases in heart rate are of unknown clinical relevance. Gastrointestinal adverse events abate over time with continued treatment and are less frequent with longer-acting GLP-1RAs. Hypoglycemia incidence is low but increased when GLP-1RAs are used with insulin secretagogues or insulin. GLP-1RAs target multiple pathophysiologic mechanisms in patients with T2D and improve glycemic control, although there are some differences within this drug class that may be relevant in clinical practice. Therefore, selection of the most appropriate treatment for individual patients is important. Topics: Blood Glucose; Blood Pressure; Body Weight; Cardiovascular Diseases; Diabetes Mellitus, Type 2; Drug Therapy, Combination; Exenatide; Glucagon-Like Peptide 1; Glucagon-Like Peptide-1 Receptor; Glucagon-Like Peptides; Glycated Hemoglobin; Humans; Hypoglycemic Agents; Immunoglobulin Fc Fragments; Insulin; Liraglutide; Metformin; Peptides; Recombinant Fusion Proteins; Risk Factors; Venoms | 2015 |
Utility of Saxagliptin in the Treatment of Type 2 Diabetes: Review of Efficacy and Safety.
Type 2 diabetes mellitus (T2DM) is a complex disease in which multiple organs and hormones contribute to the pathogenesis of disease. The intestinal hormone, glucagon-like peptide-1 (GLP-1), secreted in response to nutrient ingestion, increases insulin secretion from pancreatic β-cells and reduces glucagon secretion from pancreatic α-cells. GLP-1 is inactivated by the dipeptidyl peptidase-4 (DPP-4) enzyme. Saxagliptin is a DPP-4 inhibitor that prevents the degradation of endogenous GLP-1 and prolongs its actions on insulin and glucagon secretion. This article reviews the efficacy and safety of saxagliptin in patients with T2DM.. A PubMed literature search was conducted to identify relevant, peer-reviewed saxagliptin clinical trial articles published between January 2008 and June 2015. Search terms included "saxagliptin" and "DPP-4 inhibitors".. In clinical trials, saxagliptin significantly improved glycemic control when used as monotherapy or as add-on therapy to other antidiabetes agents and was associated with a low risk of hypoglycemia. In a large cardiovascular (CV) outcomes trial (SAVOR) in patients with T2DM and with established CV disease or multiple CV risk factors, saxagliptin neither increased nor decreased CV risk compared with placebo as assessed by the composite end point of death from CV causes, nonfatal myocardial infarction, or nonfatal stroke. Unexpectedly, more patients in the saxagliptin (3.5%) than in the placebo group (2.8%) were hospitalized for heart failure.. Saxagliptin demonstrated statistically significant and clinically meaningful improvements in glycemic control and a low risk of hypoglycemia in patients with T2DM. However, this positive profile needs to be tempered by the observation of an increased risk of hospitalization for heart failure in the SAVOR trial. Results from ongoing CV outcome trials with other DPP-4 inhibitors may provide additional data on how best to manage patients with T2DM who are at risk for heart failure.. AstraZeneca LP. Topics: Adamantane; Blood Glucose; Cardiovascular Diseases; Clinical Trials as Topic; Diabetes Mellitus, Type 2; Dipeptides; Dipeptidyl-Peptidase IV Inhibitors; Drug Therapy, Combination; Glucagon-Like Peptide 1; Humans; Hypoglycemia; Hypoglycemic Agents | 2015 |
Empagliflozin and linagliptin combination therapy for treatment of patients with type 2 diabetes mellitus.
Many patients with type 2 diabetes mellitus (T2DM) fail to achieve the desired A1c goal because the antidiabetic medications used do not correct the underlying pathophysiologic abnormalities and monotherapy is not sufficiently potent to reduce the A1c to the 6.5 - 7.0% range. Insulin resistance and islet (beta and alpha) cell dysfunction are major pathophysiologic abnormalities in T2DM. We examine combination therapy with linagliptin plus empagliflozin as a therapeutic approach for the treatment of inadequately controlled T2DM patients.. A literature search of all human diabetes, metabolism and general medicine journals from year 2000 to the present was conducted. Glucagon like peptide-1 (GLP-1) deficiency/resistance contributes to islet cell dysfunction by impairing insulin secretion and increasing glucagon secretion. DPP-4 inhibitors (DPP4i) improve pancreatic islet function by augmenting glucose-dependent insulin secretion and decreasing elevated plasma glucagon levels. Linagliptin, a DPP-4 inhibitor, reduces HbA1c, is weight neutral, has an excellent safety profile and a low risk of hypoglycemia. The expression of sodium-glucose cotransporter-2 (SGLT2) in the proximal renal tubule is upregulated in T2DM, causing excess reabsorption of filtered glucose. The SGLT2 inhibitor (SGLT2i), empagliflozin, improves HbA1c by causing glucosuria and ameliorating glucotoxicity. It also decreases weight and blood pressure, and has a low risk of hypoglycemia.. The once daily oral combination of linagliptin plus empagliflozin does not increase the risk of hypoglycemia and tolerability and discontinuation rates are similar to those with each as monotherapy. At HbA1c values below 8.5% linagliptin/empagliflozin treatment produces an additive effect, whereas above 8.5%, there is a less than additive reduction with combination therapy compared with the effect of each agent alone. Linagliptin/empagliflozin addition is a logical combination in patients with T2DM, especially those with an HbA1c < 8.5%. Topics: Benzhydryl Compounds; Diabetes Mellitus, Type 2; Dipeptidyl-Peptidase IV Inhibitors; Drug Therapy, Combination; Glucagon-Like Peptide 1; Glucose; Glucosides; Humans; Hypoglycemic Agents; Linagliptin; Sodium-Glucose Transporter 2; Sodium-Glucose Transporter 2 Inhibitors | 2015 |
The role of glucagon-like peptide-1 impairment in obesity and potential therapeutic implications.
The hormone glucagon-like peptide-1 (GLP-1) is released from the gut in response to food intake. It acts as a satiety signal, leading to reduced food intake, and also as a regulator of gastric emptying. Furthermore, GLP-1 functions as an incretin hormone, stimulating insulin release and inhibiting glucagon secretion from the pancreas in response to food ingestion. Evidence suggests that the action or effect of GLP-1 may be impaired in obese subjects, even in those with normal glucose tolerance. GLP-1 impairment may help explain the increased gastric emptying and decreased satiety signalling seen in obesity. Incretin impairment, probably associated with reduced insulinotropic potency of GLP-1, is also characteristic of type 2 diabetes (T2D). Therefore, it is possible that incretin impairment may contribute to the pathophysiological bridge between obesity and T2D. This review summarises current knowledge about the pathophysiology and consequences of GLP-1 and incretin impairment in obesity, and examines the evidence for an incretin-related link between obesity and T2D. It also considers the current literature surrounding the novel use of GLP-1 receptor agonists as a treatment for obesity in patients with normoglycaemia, prediabetes and T2D. Topics: Blood Glucose; Diabetes Mellitus, Type 2; Gastric Emptying; Gastrointestinal Motility; Glucagon-Like Peptide 1; Glucagon-Like Peptide-1 Receptor; Humans; Incretins; Insulin; Insulin Secretion; Obesity; Receptors, Glucagon; Satiation | 2014 |
Combination therapy of dipeptidyl peptidase-4 inhibitors and metformin in type 2 diabetes: rationale and evidence.
The main pathogenesis of type 2 diabetes mellitus (T2DM) includes insulin resistance and pancreatic islet dysfunction. Metformin, which attenuates insulin resistance, has been recommended as the first-line antidiabetic medication. Dipeptidyl peptidase-4 (DPP-4) inhibitors are novel oral hypoglycaemic agents that protect glucagon-like peptide-1 (GLP-1) from degradation, maintain the bioactivity of endogenous GLP-1, and thus improve islet dysfunction. Results from clinical trials have shown that the combination therapy of DPP-4 inhibitors and metformin [as an add-on, an initial combination or a fixed-dose combination (FDC)] provides excellent efficacy and safety in patients with T2DM. Moreover, recent studies have suggested that metformin enhances the biological effect of GLP-1 by increasing GLP-1 secretion, suppressing activity of DPP-4 and upregulating the expression of GLP-1 receptor in pancreatic β-cells. Conversely, DPP-4 inhibitors have a favourable effect on insulin sensitivity in patients with T2DM. Therefore, the combination of DPP-4 inhibitors and metformin provides an additive or even synergistic effect on metabolic control in patients with T2DM. This article provides an overview of clinical evidence and discusses the rationale for the combination therapy of DPP-4 inhibitors and metformin. Topics: Blood Glucose; Diabetes Mellitus, Type 2; Dipeptidyl-Peptidase IV Inhibitors; Drug Therapy, Combination; Evidence-Based Medicine; Glucagon-Like Peptide 1; Humans; Hypoglycemic Agents; Insulin-Secreting Cells; Metformin; Multicenter Studies as Topic; Randomized Controlled Trials as Topic; Treatment Outcome | 2014 |
Options for prandial glucose management in type 2 diabetes patients using basal insulin: addition of a short-acting GLP-1 analogue versus progression to basal-bolus therapy.
Integrating patient-centered diabetes care and algorithmic medicine poses particular challenges when optimized basal insulin fails to maintain glycaemic control in patients with type 2 diabetes. Multiple entwined physiological, psychosocial and systems barriers to insulin adherence are not easily studied and are not adequately considered in most treatment algorithms. Moreover, the limited number of alternatives to add-on prandial insulin therapy has hindered shared decision-making, a central feature of patient-centered care. This article considers how the addition of a glucagon-like peptide 1 (GLP-1) analogue to basal insulin may provide new opportunities at this stage of treatment, especially for patients concerned about weight gain and risk of hypoglycaemia. A flexible framework for patient-clinician discussions is presented to encourage development of decision-support tools applicable to both specialty and primary care practice. Topics: Blood Glucose; Decision Support Systems, Clinical; Diabetes Mellitus, Type 2; Dose-Response Relationship, Drug; Drug Administration Schedule; Drug Therapy, Combination; Exenatide; Fasting; Female; Glucagon-Like Peptide 1; Humans; Hypoglycemia; Hypoglycemic Agents; Insulin Detemir; Insulin, Long-Acting; Male; Meals; Patient Preference; Patient-Centered Care; Peptides; Venoms; Weight Gain | 2014 |
Effects of glucagon-like peptide-1 receptor agonists on cardiovascular risk: a meta-analysis of randomized clinical trials.
New drugs for type 2 diabetes need to demonstrate their cardiovascular safety, due regulatory requirements from the Food and Drug Administration. For this reason, glucagon-like peptide-1 receptor agonists (GLP-1 RA) are currently undergoing large-scale, long-term randomized trials specifically designed for cardiovascular outcomes. Aim of the present meta-analysis of randomized clinical trials is the assessment of the effects of GLP-1 RA on major cardiovascular events (MACE), mortality and cardiovascular risk factors.. A meta-analysis was performed including all trials with a duration of at least 6 months, comparing a GLP-1 RA with a non-GLP-1 RA agent in type 2 diabetes. MACE and mortality were retrieved and combined to calculate Mantel-Haenzel odds ratio (MH-OR). Furthermore, data on endpoint systolic and diastolic blood pressure, total and high-density lipoprotein (HDL) cholesterol and triglyceride were collected.. Of 37 selected trials, 33 reported information on MACE, and 25 reported at least one event. The difference in the incidence of MACE between GLP-1 RA and comparators did not reach statistical significance [MH-OR 0.78 (0.54-1.13), p = 0.18]. GLP-1 RA were associated with a significant reduction in the incidence of MACE in comparisons with placebo and pioglitazone, with a non-significant trend towards reduction in DPP4i-controlled studies. No significant effect of GLP-1 RA was observed on mortality, although a non-significant favourable trend was observed in comparisons with placebo.. The present meta-analysis confirms the cardiovascular safety of GLP-1 RA, at least in the short term and in low-risk individuals. GLP-1 RA could have a beneficial effect on the incidence of MACE, at least in comparison with placebo. Topics: Cardiovascular Diseases; Diabetes Mellitus, Type 2; Exenatide; Female; Glucagon-Like Peptide 1; Glucagon-Like Peptide-1 Receptor; Humans; Hypoglycemic Agents; Liraglutide; Male; Peptides; Randomized Controlled Trials as Topic; Receptors, Glucagon; Risk Factors; Venoms | 2014 |
Molecular mechanisms underlying physiological and receptor pleiotropic effects mediated by GLP-1R activation.
The incidence of type 2 diabetes in developed countries is increasing yearly with a significant negative impact on patient quality of life and an enormous burden on the healthcare system. Current biguanide and thiazolidinedione treatments for type 2 diabetes have a number of clinical limitations, the most serious long-term limitation being the eventual need for insulin replacement therapy (Table 1). Since 2007, drugs targeting the glucagon-like peptide-1 (GLP-1) receptor have been marketed for the treatment of type 2 diabetes. These drugs have enjoyed a great deal of success even though our underlying understanding of the mechanisms for their pleiotropic effects remain poorly characterized even while major pharmaceutical companies actively pursue small molecule alternatives. Coupling of the GLP-1 receptor to more than one signalling pathway (pleiotropic signalling) can result in ligand-dependent signalling bias and for a peptide receptor such as the GLP-1 receptor this can be exaggerated with the use of small molecule agonists. Better consideration of receptor signalling pleiotropy will be necessary for future drug development. This is particularly important given the recent failure of taspoglutide, the report of increased risk of pancreatitis associated with GLP-1 mimetics and the observed clinical differences between liraglutide, exenatide and the newly developed long-acting exenatide long acting release, albiglutide and dulaglutide. Topics: Animals; Diabetes Mellitus, Type 2; Glucagon-Like Peptide 1; Glucagon-Like Peptide-1 Receptor; Humans; Incretins; Protein Conformation; Receptors, Glucagon | 2014 |
Incretin-based therapies: can we achieve glycemic control and cardioprotection?
Glucagon-like (GLP-1) is a peptide hormone secreted from the small intestine in response to nutrient ingestion. GLP-1 stimulates insulin secretion in a glucose-dependent manner, inhibits glucagon secretion and gastric emptying, and reduces appetite. Because of the short circulating half-life of the native GLP-1, novel GLP-1 receptor (GLP-1R) agonists and analogs and dipeptidyl peptidase 4 (DPP-4) inhibitors have been developed to facilitate clinical use. Emerging evidence indicates that GLP-1-based therapies are safe and may provide cardiovascular (CV) benefits beyond glycemic control. Preclinical and clinical studies are providing increasing evidence that GLP-1 therapies may positively affect CV function and metabolism by salutary effects on CV risk factors as well as via direct cardioprotective actions. However, the mechanisms whereby the various classes of incretin-based therapies exert CV effects may be mechanistically distinct and may not necessarily lead to similar CV outcomes. In this review, we will discuss the potential mechanisms and current understanding of CV benefits of native GLP-1, GLP-1R agonists and analogs, and of DPP-4 inhibitor therapies as a means to compare their putative CV benefits. Topics: Animals; Blood Glucose; Cardiovascular System; Diabetes Mellitus, Type 2; Glucagon-Like Peptide 1; Humans; Hypoglycemic Agents; Incretins | 2014 |
[Type 2 diabetes mellitus: new treatments].
The benefits and problems associated with traditional hypoglycemic drugs, such as failure of beta cells, hypoglycemia and weight gain, that lead to a worsening of diabetes, are reviewed. New hypoglycemic drugs with incretin effect (glucagon-like peptide-1 agonists and dipeptidyl peptidase 4 inhibitors), achieve, in a glucose dependent manner, an glycosylated hemoglobin reduction without hypoglycemia or increase in body weight. Recently, another group of oral hypoglycemic drugs, sodium-glucose cotransporter type 2 inhibitors, have demonstrated efficacy in diabetes control by inhibiting renal glucose reabsorption. However, long-term effects and cardiovascular prevention remain to be demonstrated. We have more and better drugs nowadays. Hypoglycemic treatment should be customized (glycosylated hemoglobin levels, risk-benefit, risk of hypoglycemia, weight changes, cardiovascular risk), with a combination of drugs being necessary in most cases. However, we do not have yet an ideal hypoglycemic drug. Moreover we must remember that an early and intensive treatment of dyslipidemia and hypertension is essential for the prevention of cardiovascular disease in patients with type 2 diabetes. Topics: Diabetes Mellitus, Type 2; Glucagon-Like Peptide 1; Humans; Hypoglycemic Agents; Sodium-Glucose Transporter 2; Sodium-Glucose Transporter 2 Inhibitors | 2014 |
Is treatment with liraglutide efficient?
In the current context of limited economic and health resources, efficiency of drug treatments is of paramount importance, and their clinical effects and related direct costs should therefore be analyzed. Liraglutide is a glucagon-like peptide-1 (GLP-1) receptor agonist approved for the treatment of type 2 diabetes mellitus (T2DM) which, in addition to its normoglycemic effects, induces a significant improvement in body weight and several cardiovascular risk factors. The aim of this narrative review is to summarize the available evidence about the effects of liraglutide upon cardiovascular risk factors and how these improve its cost-effectiveness profile. Despite the relatively higher cost of liraglutide as compared to other alternative therapies, liraglutide has been shown to be cost-effective when clinical indicators and total costs associated to T2DM management are analyzed. Topics: Cardiovascular Diseases; Cost-Benefit Analysis; Diabetes Mellitus, Type 2; Glucagon-Like Peptide 1; Humans; Hypoglycemic Agents; Liraglutide; Risk Factors; Treatment Outcome | 2014 |
Food protein hydrolysates as a source of dipeptidyl peptidase IV inhibitory peptides for the management of type 2 diabetes.
The prevalence of type 2 diabetes mellitus (T2DM) is increasing and it is estimated that by 2030 approximately 366 million people will be diagnosed with this condition. The use of dipeptidyl peptidase IV (DPP-IV) inhibitors is an emerging strategy for the treatment of T2DM. DPP-IV is a ubiquitous aminodipeptidase that cleaves incretins such as glucagon like peptide 1 (GLP-1) and glucose-dependent insulinotropic polypeptide (GIP), resulting in a loss in their insulinotropic activity. Synthetic DPP-IV drug inhibitors are being used to increase the half-life of the active GLP-1 and GIP. Dietary intervention is accepted as a key component in the prevention and management of T2DM. Therefore, identification of natural food protein-derived DPP-IV inhibitors is desirable. Peptides with DPP-IV inhibitory activity have been identified in a variety of food proteins. This review aims to provide an overview of food protein hydrolysates as a source of the DPP-IV inhibitory peptides with particular focus on milk proteins. In addition, the proposed modes of inhibition and structure-activity relationship of peptide inhibitors are discussed. Milk proteins and associated peptides also display insulinotropic activity and help regulate blood glucose in healthy and diabetic subjects. Therefore, milk protein derived peptide inhibitors may be a unique multifunctional peptide approach for the management of T2DM. Topics: Animals; Blood Glucose; Diabetes Mellitus, Type 2; Dietary Proteins; Dipeptidyl Peptidase 4; Dipeptidyl-Peptidase IV Inhibitors; Gastric Inhibitory Polypeptide; Glucagon-Like Peptide 1; Humans; Hypoglycemic Agents; Milk Proteins; Peptides; Protein Hydrolysates | 2014 |
Composite endpoints in trials of type-2 diabetes.
Composite endpoints (CEPs) are being used more frequently as outcomes for trials of drugs in type-2 diabetes. We reviewed the literature to determine how CEPs have been used to date in trials of drugs for type-2 diabetes. A systematic search was undertaken on Medline, Embase and Cochrane databases and Clinicaltrials.gov for randomized controlled trials of currently marketed agents including SGLT-2 inhibitors (dapagliflozin), GLP-1 agonists (exenatide, liraglutide) and DPP-4 inhibitors (linagliptin, saxagliptin, sitagliptin and vildagliptin). CEPs used were identified as well as numbers and percentages of patients achieving each. Thirty-six studies were identified that reported results on ≥1 CEP; 15 different CEPs were reported (7 with 2 components, 8 with 3 components). All CEPs addressed goals recommended by the American Diabetes Association (ADA). All included HbA1c<7%; other endpoints measured weight, blood pressure and hypoglycaemic events. Results were obtained for CEPs from 6 months to 2 years. Rates of achieving CEPs decreased with increasing numbers of components and outcomes assessed. CEPs are becoming used as indicators of clinical outcomes in type-2 diabetes trials, but are still not common. More research is required to identify optimal CEPs. Standardization of outcomes and their reporting is needed. Topics: Diabetes Mellitus, Type 2; Dipeptidyl-Peptidase IV Inhibitors; Glucagon-Like Peptide 1; Humans; Hypoglycemic Agents; Randomized Controlled Trials as Topic; Sodium-Glucose Transporter 2; Sodium-Glucose Transporter 2 Inhibitors | 2014 |
Use of glucagon-like peptide-1 receptor agonists and bone fractures: a meta-analysis of randomized clinical trials.
Patients with type 2 diabetes mellitus (T2DM) are at a higher risk of bone fractures independent of the use of antidiabetic medications. Furthermore, antidiabetic medications could directly affect bone metabolism. Recently, the use of dipeptidyl peptidase-4 inhibitors has been associated with a lower rate of bone fracture. The aim of the present meta-analysis was to assess whether patients with T2DM treated with glucagon-like peptide-1 receptor agonists (GLP-1Ra) present a lower incidence of bone fracture compared with patients using other antidiabetic drugs.. A search on Medline, Embase, and http://www.clinicaltrials.gov, as well as a manual search for randomized clinical trials of T2DM treated with either a GLP-1Ra or another antidiabetic drug for a duration of ≥24 weeks was conducted by two authors (GM, AM) independently.. Although 28 eligible studies were identified, only seven trials reported the occurrence of at least a bone fracture in one arm of the trial. The total number of fractures was 19 (13 and six with GLP-1Ra and comparator, respectively). The pooled Mantel-Haenszel odds ratio for GLP-1Ra was 0.75 (95% confidence interval 0.28-2.02, P = 0.569) in trials versus other antidiabetic agents.. Although preliminary, our study highlighted that the use of GLP-1Ra does not modify the risk of bone fracture in T2DM compared with the use of other antidiabetic medications. Topics: Diabetes Mellitus, Type 2; Exenatide; Fractures, Bone; Glucagon-Like Peptide 1; Glucagon-Like Peptide-1 Receptor; Humans; Hypoglycemic Agents; Liraglutide; Peptides; Randomized Controlled Trials as Topic; Receptors, Glucagon; Treatment Outcome; Venoms | 2014 |
Effect of GLP-1 mimetics on blood pressure and relationship to weight loss and glycemia lowering: results of a systematic meta-analysis and meta-regression.
Incretin therapies such as glucagon-like peptide 1 (GLP-1) agonists are commonly used for the treatment of type 2 diabetes mellitus. GLP-1 mimetics, besides improving glycemic control, have been shown to influence multiple pathways regulating blood pressure (BP). We investigated the GLP-1 analogs effects on BP from published randomized studies using a meta-analytic approach.. Thirty-three trials (12,469 patients) that assessed the efficacy of GLP-1 analogs on glycemic control (HbA1C) over 12-56 weeks that met additional criteria, including the availability of standardized sitting BP assessment and weight parameters, were identified. Comparator therapy included oral antiglycemic drugs or placebo. The weighted mean difference (WMD) in systolic BP (SBP) change was calculated using a random-effects model after performing a test for heterogeneity.. Forty-one percent of patients were treated with liraglutide (0.3-3mg once daily), whereas 59% were treated with exenatide (5-10 µg twice daily or 2mg weekly). GLP-1 treatment achieved a greater SBP reduction than comparator therapy (WMD = 2.22mm Hg; 95% confidence interval (CI) = -2.97 to -1.47). In the pooled analysis, GLP-1 had beneficial effects on weight loss (WMD = -2.56kg; 95% CI = -3.12 to -2.00), HbA1c reduction (WMD = -0.41%; 95% CI = -0.78 to -0.04) but was associated with a heart rate increase (WMD = 1.30 bpm; 95% CI = 0.26-2.33). In a separate meta-regression analysis, the degree of SBP change was not related to baseline BP, weight loss, or improvement in HbA1C.. This meta-analysis provides evidence that GLP-1 analogs reduce sitting SBP. These findings may support potentially favorable long-term cardiovascular outcomes. Topics: Biomarkers; Blood Glucose; Blood Pressure; Diabetes Mellitus, Type 2; Exenatide; Glucagon-Like Peptide 1; Glycated Hemoglobin; Humans; Hypoglycemic Agents; Incretins; Liraglutide; Peptides; Time Factors; Treatment Outcome; Venoms; Weight Loss | 2014 |
Effects of glucagon-like peptide 1 on appetite and body weight: focus on the CNS.
The delivery of nutrients to the gastrointestinal tract after food ingestion activates the secretion of several gut-derived mediators, including the incretin hormone glucagon-like peptide 1 (GLP-1). GLP-1 receptor agonists (GLP-1RA), such as exenatide and liraglutide, are currently employed successfully in the treatment of patients with type 2 diabetes mellitus. GLP-1RA improve glycaemic control and stimulate satiety, leading to reductions in food intake and body weight. Besides gastric distension and peripheral vagal nerve activation, GLP-1RA induce satiety by influencing brain regions involved in the regulation of feeding, and several routes of action have been proposed. This review summarises the evidence for a physiological role of GLP-1 in the central regulation of feeding behaviour and the different routes of action involved. Also, we provide an overview of presently available data on pharmacological stimulation of GLP-1 pathways leading to alterations in CNS activity, reductions in food intake and weight loss. Topics: Animals; Appetite; Body Weight; Central Nervous System; Diabetes Mellitus, Type 2; Glucagon-Like Peptide 1; Humans | 2014 |
The extra-pancreatic effects of GLP-1 receptor agonists: a focus on the cardiovascular, gastrointestinal and central nervous systems.
The glucagon-like peptide-1 receptor agonists (GLP-1RAs) exenatide, liraglutide and lixisenatide have been shown to improve glycaemic control and beta-cell function with a low risk of hypoglycaemia in people with type 2 diabetes. GLP-1 receptors are also expressed in extra-pancreatic tissues and trial data suggest that GLP-1RAs also have effects beyond their glycaemic actions. Preclinical studies using native GLP-1 or GLP-1RAs provide substantial evidence for cardioprotective effects, while clinical trial data have shown beneficial actions on hypertension and dyslipidaemia in people with type 2 diabetes. Significant weight loss has been reported with GLP-1RAs in both people with type 2 diabetes and obese people without diabetes. GLP-1RAs also slow down gastric emptying, but preclinical data suggest that the main mechanism behind GLP-1RA-induced weight loss is more likely to involve their effects on appetite signalling in the brain. GLP-1RAs have also been shown to exert a neuroprotective role in rodent models of stroke, Alzheimer's disease and Parkinson's disease. These extra-pancreatic effects of GLP-1RAs could provide multi-factorial benefits to people with type 2 diabetes. Potential adverse effects of GLP-1RA treatment are usually manageable but may include gastrointestinal effects, increased heart rate and renal injury. While extensive further research is still required, early data suggest that GLP-1RAs may also have the potential to favourably impact cardiovascular disease, obesity or neurological disorders in people without diabetes in the future. Topics: Animals; Diabetes Complications; Diabetes Mellitus, Type 2; Diabetic Cardiomyopathies; Diabetic Neuropathies; Evidence-Based Medicine; Exenatide; Gastrointestinal Diseases; Glucagon-Like Peptide 1; Glucagon-Like Peptide-1 Receptor; Humans; Hypoglycemic Agents; Incretins; Liraglutide; Obesity; Peptides; Receptors, Glucagon; Venoms | 2014 |
Regulation of glucose homeostasis by GLP-1.
Glucagon-like peptide-1(7-36)amide (GLP-1) is a secreted peptide that acts as a key determinant of blood glucose homeostasis by virtue of its abilities to slow gastric emptying, to enhance pancreatic insulin secretion, and to suppress pancreatic glucagon secretion. GLP-1 is secreted from L cells of the gastrointestinal mucosa in response to a meal, and the blood glucose-lowering action of GLP-1 is terminated due to its enzymatic degradation by dipeptidyl-peptidase-IV (DPP-IV). Released GLP-1 activates enteric and autonomic reflexes while also circulating as an incretin hormone to control endocrine pancreas function. The GLP-1 receptor (GLP-1R) is a G protein-coupled receptor that is activated directly or indirectly by blood glucose-lowering agents currently in use for the treatment of type 2 diabetes mellitus (T2DM). These therapeutic agents include GLP-1R agonists (exenatide, liraglutide, lixisenatide, albiglutide, dulaglutide, and langlenatide) and DPP-IV inhibitors (sitagliptin, vildagliptin, saxagliptin, linagliptin, and alogliptin). Investigational agents for use in the treatment of T2DM include GPR119 and GPR40 receptor agonists that stimulate the release of GLP-1 from L cells. Summarized here is the role of GLP-1 to control blood glucose homeostasis, with special emphasis on the advantages and limitations of GLP-1-based therapeutics. Topics: Animals; Diabetes Mellitus, Type 2; Glucagon-Like Peptide 1; Glucagon-Like Peptide-1 Receptor; Glucose; Homeostasis; Humans; Insulin-Secreting Cells; Receptors, Glucagon | 2014 |
Do incretins improve endothelial function?
An impaired endothelial function has been recognized in the early stage of atherosclerosis, and is a major factor affecting the future development of cardiovascular events. Type 2 diabetes mellitus (T2DM) is widely prevalent, and is one of the most important risk factors for cardiovascular disease. T2DM is associated with increases in both morbidity and mortality, particularly from cardiovascular disease.New therapies based on the incretin hormone and its actions are now becoming widely used, and appear to offer advantages over conventional therapies by keeping the body weight steady and limiting hypoglycemia, while also achieving attractive glycemic control. However, there is little data available about the effects of incretins on the cardiovascular system.This review will focus on the effects of incretin therapies, including glucagon-like peptide-1 (GLP-1) analogs and dipeptidyl peptidase (DPP)-4 inhibitors, on the endothelial function, and will discuss the potential mechanisms underlying these effects. Topics: Animals; Cardiovascular Diseases; Diabetes Mellitus, Type 2; Dipeptidyl-Peptidase IV Inhibitors; Glucagon-Like Peptide 1; Humans; Hypoglycemic Agents; Incretins; Risk Factors | 2014 |
A systematic review and meta-analysis of the efficacy of lixisenatide in the treatment of patients with type 2 diabetes.
The aim of this study is to assess the efficacy and safety of lixisenatide for treating type 2 diabetes. A systematic search in electronic databases (up to October 2012) was conducted and the manufacturer was contacted regarding unpublished data. Randomized controlled trials (RCTs) were included if they provided information on at least one of the following outcomes: mortality, health-related quality of life, hypoglycaemic events, adverse events, change in HbA1c, body weight, blood pressure, gastric emptying, fasting plasma glucose or 2 h postprandial glucose (PPG). Twenty-six publications and 10 unpublished study reports, relating to 14 RCTs (6156 patients) were included. Eleven studies related to placebo comparisons; active comparators were in three studies. Compared to placebo, lixisenatide significantly reduced HbA1c (-0.52%; 95% CI: -0.64 to -0.39), bodyweight (-0.65 kg; 95% CI: -0.94 to -0.37) and 2-h PPG level (-4.58 mmol/l; 95% CI: -5.88 to -3.28). There were significantly more symptomatic hypoglycaemic events among lixisenatide compared to placebo-treated patients (log OR: 0.54; 95% CI: 0.32-0.75), but significantly fewer compared to other incretin mimetics. In comparison to exenatide and liraglutide, lixisenatide was more effective in reducing 2 h-PPG with a better adverse events profile, but it showed a lower reduction in HbA1c and body weight. Lixisenatide improves HbA1c levels and moderately reduces body weight compared to placebo and showed less frequent symptomatic hypoglycaemic and gastrointestinal events and an improvement in PPG control compared to other GLP-1 agonists. Firm conclusions regarding the performance of lixisenatide compared to other incretin mimetics, however, can not yet be drawn, due to limited data. Topics: Blood Glucose; Blood Pressure; Body Weight; Diabetes Mellitus, Type 2; Evidence-Based Medicine; Gastric Emptying; Glucagon-Like Peptide 1; Glycated Hemoglobin; Humans; Hypoglycemic Agents; Peptides; Quality of Life; Randomized Controlled Trials as Topic; Treatment Outcome | 2014 |
Glucagon-like peptide-1 receptor agonists and pancreatitis: a meta-analysis of randomized clinical trials.
Several randomized trials with metabolic outcomes have reported that glucagon like peptide-1 receptor agonists (GLP-1 RA) could be associated with an increased risk of pancreatitis. The present meta-analysis aimed to examine this hypothesis.. An extensive Medline, Embase, and Cochrane Database search for "exenatide", "liraglutide", "albiglutide", "taspoglutide", "dulaglutide", "lixisenatide", and "semaglutide" was performed up to March 31st, 2013.. (i) randomized trials, (ii) duration ≥12 weeks; (iii) on type 2 diabetes; and (iv) comparison of GLP-1RA with placebo or active drugs. Mantel-Haenszel odds ratio with 95% confidence interval (MH-OR) was calculated for pancreatitis.. 80 eligible trials were identified. Of these, 39 had not disclosed their findings or did not report any information on pancreatitis. The remaining 41 trials enrolled 14,972 patients, with a total exposure of 14,333 patient × years (8353 and 5980 patient × years for GLP-1 receptor agonists and comparators, respectively). The overall risk of pancreatitis was not different between GLP-1RA and comparators (MH-OR: 1.01[0.37; 2.76]; p = 0.99).. The present meta-analysis does not suggest any increase in the risk of pancreatitis with the use of GLP-1RA. However, it should be recognized that the number of observed cases of incident pancreatitis is very small and the confidence intervals of risk estimates are wide. Topics: Diabetes Mellitus, Type 2; Exenatide; Glucagon-Like Peptide 1; Glucagon-Like Peptide-1 Receptor; Humans; Hypoglycemic Agents; Liraglutide; Pancreatitis; Peptides; Randomized Controlled Trials as Topic; Receptors, Glucagon; Venoms | 2014 |
Effects of incretin-based therapy in patients with heart failure and myocardial infarction.
Studies designed to evaluate the short-term effects of incretin-related drugs in subjects with cardiac disease are still preliminary. In patients with heart failure, two of five studies showed that glucagon-like peptide-1 (GLP-1) infusion was associated with an absolute increase in left ventricular ejection fraction (LVEF) by 6-10 %, whereas no significant benefit was observed in the remaining three studies. In patients with coronary artery disease, single infusion of the GLP-1 receptor analog, exenatide, did not increase LVEF, but this drug may decrease infarct size in patients with myocardial infarction presenting with short duration of ischemic symptoms. Single dose of GLP-1 and the dipeptidyl-peptidase-IV (DPP-IV) inhibitor, sitagliptin, may improve left ventricular function, predominantly in ischemic segments, and attenuate post-ischemic stunning. Nausea, vomiting and hypoglycemia were the most common adverse effects associated with GLP-1 and exenatide administration. Increased heart rate was also observed with exenatide in patients with heart failure. Large randomized trials including diabetic patients with preexisting heart failure and myocardial infarction showed that chronic therapy with the DPP-IV inhibitors saxagliptin and alogliptin did not reduce cardiovascular events or mortality. Moreover, saxagliptin use was associated with significant increase in frequency of heart failure requiring hospitalization, hypoglycemia and angioedema. Overall, short-term preliminary data suggest potential cardioprotective effects of exenatide and sitagliptin in patients with heart failure and myocardial infarction. Meanwhile, long-term randomized trials suggest no benefit of alogliptin, and increased harm associated with the use of saxagliptin. Topics: Animals; Cardiotonic Agents; Diabetes Mellitus, Type 2; Diabetic Angiopathies; Exenatide; Glucagon-Like Peptide 1; Heart Failure; Humans; Hypoglycemic Agents; Incretins; Myocardial Infarction; Peptides; Venoms | 2014 |
Role of endogenous GLP-1 and its agonists in osteopenia and osteoporosis: but we little know until tried.
The present brief review looks at the evidence on the role of GLP-1 and its agonists in osteopenia and osteoporosis in type 2 diabetes (T2DM). There is accumulating data to suggest a favourable effect of GLP-1 on bone metabolism. However, most data is from experimental studies, while clinical confirmation is still inadequate. Moreover, little is known on the precise mechanisms underlying these effects. Therefore, we need randomised clinical trials in T2DM patients to learn more on the action of GLP-1 on bone metabolism and its potential clinical implications. Topics: Bone and Bones; Bone Diseases, Metabolic; Calcitonin; Diabetes Mellitus, Type 2; Exenatide; Female; Glucagon-Like Peptide 1; Glucagon-Like Peptide-1 Receptor; Humans; Male; Osteoporosis; Peptides; Receptors, Glucagon; Treatment Outcome; Venoms | 2014 |
New and emerging regulators of intestinal lipoprotein secretion.
Overproduction of hepatic apoB100-containing VLDL particles has been well documented in animal models and in humans with insulin resistance such as the metabolic syndrome and type 2 diabetes, and contributes to the typical dyslipidemia of these conditions. In addition, postprandial hyperlipidemia and elevated plasma concentrations of intestinal apoB48-containing chylomicron and chylomicron remnant particles have been demonstrated in insulin resistant states. Intestinal lipoprotein production is primarily determined by the amount of fat ingested and absorbed. Until approximately 10 years ago, however, relatively little attention was paid to the role of the intestine itself in regulating the production of triglyceride-rich lipoproteins (TRL) and its dysregulation in pathological states such as insulin resistance. We and others have shown that insulin resistant animal models and humans are characterized by overproduction of intestinal apoB48-containing lipoproteins. Whereas various factors are known to regulate hepatic lipoprotein particle production, less is known about factors that regulate the production of intestinal lipoprotein particles. Monosacharides, plasma free fatty acids (FFA), resveratrol, intestinal peptides (e.g. GLP-1 and GLP-2), and pancreatic hormones (e.g. insulin) have recently been shown to be important regulators of intestinal lipoprotein secretion. Available evidence in humans and animal models strongly supports the concept that the small intestine is not merely an absorptive organ but rather plays an active role in regulating the rate of production of chylomicrons in fed and fasting states. Metabolic signals in insulin resistance and type 2 diabetes and in some cases an aberrant intestinal response to these factors contribute to the enhanced formation and secretion of TRL. Understanding the regulation of intestinal lipoprotein production is imperative for the development of new therapeutic strategies for the prevention and treatment of dyslipidemia. Here we review recent developments in this field and present evidence that intestinal lipoprotein production is a process with metabolic plasticity and that modulation of intestinal lipoprotein secretion may be a feasible therapeutic strategy in the treatment of dyslipidemia and possibly prevention of atherosclerosis. Topics: Animals; Apolipoprotein B-100; Apolipoprotein B-48; Atherosclerosis; Bile Acids and Salts; Cholesterol; Chylomicrons; Clinical Trials as Topic; Diabetes Mellitus, Type 2; Dietary Carbohydrates; Dietary Fats; Dipeptidyl-Peptidase IV Inhibitors; Drug Evaluation, Preclinical; Dyslipidemias; Exenatide; Fatty Acids, Nonesterified; Glucagon-Like Peptide 1; Glucagon-Like Peptide 2; Glucagon-Like Peptide-1 Receptor; Humans; Incretins; Insulin; Insulin Resistance; Intestine, Small; Lipoproteins; Microbiota; Peptides; Receptors, Glucagon; Resveratrol; Secretory Rate; Stilbenes; Triglycerides; Venoms | 2014 |
Incorporating incretin-based therapies into clinical practice for patients with type 2 diabetes.
Effective, evidence-based management of type 2 diabetes (T2D) requires the integration of the best available evidence with clinical experience and patient preferences.. Studies published from 2000 to 2012 evaluating glucagon-like peptide-1 receptor agonists (GLP-1RAs) or dipeptidyl peptidase-4 inhibitors (DPP-4 inhibitors) were identified using PubMed. The author contextualized the study findings with his clinical experience.. Incretin-based therapy targets multiple dysfunctional organs in T2D. Injectable GLP-1RAs provide substantial glycemic control and weight reduction; while oral DPP-4 inhibitors provide moderate glycemic control and weight neutrality. Both classes are effective, well tolerated, and associated with a low incidence of hypoglycemia when used alone or in combination with other antidiabetes agents. GLP-1RAs are associated with transient nausea and, like DPP-4 inhibitors, rare pancreatitis.. Data indicate and clinical experience confirms that incretins are well tolerated in appropriate patients and provide sustained glycemic control and weight loss or weight neutrality throughout T2D progression. Topics: Adamantane; Diabetes Mellitus, Type 2; Dipeptides; Dipeptidyl-Peptidase IV Inhibitors; Exenatide; Glucagon-Like Peptide 1; Glucagon-Like Peptide-1 Receptor; Humans; Hypoglycemic Agents; Linagliptin; Liraglutide; Peptides; Piperidines; Purines; Pyrazines; Quinazolines; Receptors, Glucagon; Sitagliptin Phosphate; Treatment Outcome; Triazoles; Uracil; Venoms; Weight Loss | 2014 |
The nonhuman primate as a model for type 2 diabetes.
Although rodent models provide insight into the mechanisms underlying type 2 diabetes mellitus (T2DM), they are limited in their translatability to humans. The nonhuman primate (NHP) shares important metabolic similarities with the human, making it an ideal model for the investigation of type 2 diabetes and use in preclinical trials. This review highlights the key contributions in the field over the last year using the NHP model.. The NHP has not only provided novel insight into the normal and pathological processes that occur within the islet, but has also allowed for the preclinical testing of novel pharmaceutical targets for obesity and T2DM. Particularly, administration of fibroblast growth factor-21 in the NHP resulted in weight loss and improvements in metabolic health, supporting rodent studies and recent clinical trials. In addition, the NHP was used to demonstrate that a novel melanocortin-4 receptor agonist did not cause adverse cardiovascular effects. Finally, this model has been used to provide evidence that glucagon-like peptide-1-based therapies do not induce pancreatitis in the healthy NHP.. The insight gained from studies using the NHP model has allowed for a better understanding of the processes driving T2DM and has promoted the development of well tolerated and effective treatments. Topics: Animals; Diabetes Mellitus, Experimental; Diabetes Mellitus, Type 2; Diet, High-Fat; Disease Models, Animal; Female; Glucagon-Like Peptide 1; Hypoglycemic Agents; Insulin-Secreting Cells; Macaca mulatta; Male; Pancreatitis; Weight Loss | 2014 |
GLP-1-based strategies: a physiological analysis of differential mode of action.
DPP4 inhibitors and GLP-1 receptor agonists used in incretin-based strategies treat Type 2 diabetes with different modes of action. The pharmacological blood GLP-1R agonist concentration targets pancreatic and some extrapancreatic GLP-1R, whereas DPP4i favors the physiological activation of the gut-brain-periphery axis that could allow clinicians to adapt the management of Type 2 diabetes, according to the patient's pathophysiological characteristics. Topics: Animals; Brain; Diabetes Mellitus, Type 2; Dipeptidyl Peptidase 4; Glucagon-Like Peptide 1; Glucagon-Like Peptide-1 Receptor; Humans; Incretins; Receptors, Glucagon | 2014 |
New developments in diabetes management: medications of the 21st century.
Suboptimal blood glucose control among patients with type 2 diabetes continues to support the need for new pharmacologic approaches.. The purpose of this commentary was to highlight newly available and soon-to-be available agents that are promising tools for targeting specific pathophysiologic pathways in the management of diabetes.. Published evidence to support the application of novel incretin-based therapies, dipeptidyl peptidase (DPP)-4 inhibitors, sodium-glucose cotransporter (SGLT)-2 inhibitors, other oral agents and insulins for managing specific aspects of type 2 diabetes, as well as disadvantages associated with those novel medications, are discussed.. Several new glucagon-like peptide (GLP)-1 receptor agonists with different time frames of action, although each has unique advantages and disadvantages, have been through clinical trials. Examples of these are lixisenatide and albiglutide. Currently available DPP-4 inhibitor agents, important for inhibiting the breakdown of endogenous GLP-1, have not been associated with weight gain or hypoglycemia. SGLT-2 inhibitors, which do not depend on insulin secretion or insulin action, may be advantageous in that they appear to be broadly efficacious at all stages of diabetes. New insulin analogues, such as degludec and U-500, improve glycemic control without contributing to hypoglycemia.. Advances in pharmacologic options offer the promise of improving glycemic control for longer periods, with limited glycemic fluctuations, hypoglycemia, and weight gain. However, the effectiveness of these agents ultimately depends on their availability to providers managing the health care of patients at high risk for poor diabetes outcomes and patients' use of them as directed. Long-term effectiveness and safety trials are ongoing. Topics: Blood Glucose; Diabetes Mellitus, Type 2; Dipeptidyl-Peptidase IV Inhibitors; Female; Glucagon-Like Peptide 1; Humans; Hypoglycemia; Hypoglycemic Agents; Incretins; Insulin; Insulin, Long-Acting; Male; Peptides | 2014 |
Molecular evolution of GPCRs: GLP1/GLP1 receptors.
Glucagon-like peptide 1 (GLP1) is an intestinal incretin that regulates glucose homeostasis through stimulation of insulin secretion from pancreatic β-cells and inhibits appetite by acting on the brain. Thus, it is a promising therapeutic agent for the treatment of type 2 diabetes mellitus and obesity. Studies using synteny and reconstructed ancestral chromosomes suggest that families for GLP1 and its receptor (GLP1R) have emerged through two rounds (2R) of whole genome duplication and local gene duplications before and after 2R. Exon duplications have also contributed to the expansion of the peptide family members. Specific changes in the amino acid sequence following exon/gene/genome duplications have established distinct yet related peptide and receptor families. These specific changes also confer selective interactions between GLP1 and GLP1R. In this review, we present a possible macro (genome level)- and micro (gene/exon level)-evolution mechanisms of GLP1 and GLP1R, which allows them to acquire selective interactions between this ligand-receptor pair. This information may provide critical insight for the development of potent therapeutic agents targeting GLP1R. Topics: Amino Acid Sequence; Animals; Diabetes Mellitus, Type 2; Evolution, Molecular; Gene Duplication; Glucagon-Like Peptide 1; Glucagon-Like Peptide-1 Receptor; Glucose; Humans; Insulin; Insulin Secretion; Obesity; Receptors, Glucagon; Vertebrates | 2014 |
Incretins and the intensivist: what are they and what does an intensivist need to know about them?
Hyperglycaemia occurs frequently in the critically ill, even in those patients without a history of diabetes. The mechanisms underlying hyperglycaemia in this group are complex and incompletely defined. In health, the gastrointestinal tract is an important modulator of postprandial glycaemic excursions and both the rate of gastric emptying and the so-called incretin hormones, glucagon-like peptide-1 and glucose-dependent insulinotropic polypeptide, are pivotal determinants of postprandial glycaemia. Incretin-based therapies (that is, glucagon-like peptide- 1 agonists and dipeptidyl-peptidase-4 inhibitors) have recently been incorporated into standard algorithms for the management of hyperglycaemia in ambulant patients with type 2 diabetes and, inevitably, an increasing number of patients who were receiving these classes of drugs prior to their acute illness will present to ICUs. This paper summarises current knowledge of the incretin effect as well as the incretin-based therapies that are available for the management of type 2 diabetes, and provides suggestions for the potential relevance of these agents in the management of dysglycaemia in the critically ill, particularly to normalise elevated blood glucose levels. Topics: Animals; Blood Glucose; Diabetes Mellitus, Type 2; Dipeptidyl-Peptidase IV Inhibitors; Glucagon-Like Peptide 1; Humans; Hyperglycemia; Incretins | 2014 |
Incretin therapy and heart failure.
Type 2 diabetes mellitus (T2DM) is widely prevalent and a critical risk factor for cardiovascular disease that increases both morbidity and mortality. Recently, new therapies based on the actions of the incretin hormones have become widely used, offering advantages over conventional treatments by limiting hypoglycemia and achieving glycemic control. Moreover, many experimental studies have suggested that GLP-1 and related drugs exert cardioprotective effects on atherosclerosis and cardiac dysfunction both in vitro and in vivo. However, there is thus far little clinical evidence supporting the efficacy of incretin therapy in patients with cardiovascular disease. This review focuses on the effects of GLP-1-related therapy on cardiac function from the bench to the bed, with a discussion of possible underlying mechanisms. Topics: Animals; Diabetes Complications; Diabetes Mellitus, Type 2; Glucagon-Like Peptide 1; Heart Failure; Humans; Incretins | 2014 |
Comparative effectiveness of dipeptidyl peptidase-4 (DPP-4) inhibitors and human glucagon-like peptide-1 (GLP-1) analogue as add-on therapies to sulphonylurea among diabetes patients in the Asia-Pacific region: a systematic review.
The prevalence of diabetes mellitus is rising globally, and it induces a substantial public health burden to the healthcare systems. Its optimal control is one of the most significant challenges faced by physicians and policy-makers. Whereas some of the established oral hypoglycaemic drug classes like biguanide, sulphonylureas, thiazolidinediones have been extensively used, the newer agents like dipeptidyl peptidase-4 (DPP-4) inhibitors and the human glucagon-like peptide-1 (GLP-1) analogues have recently emerged as suitable options due to their similar efficacy and favorable side effect profiles. These agents are widely recognized alternatives to the traditional oral hypoglycaemic agents or insulin, especially in conditions where they are contraindicated or unacceptable to patients. Many studies which evaluated their clinical effects, either alone or as add-on agents, were conducted in Western countries. There exist few reviews on their effectiveness in the Asia-Pacific region. The purpose of this systematic review is to address the comparative effectiveness of these new classes of medications as add-on therapies to sulphonylurea drugs among diabetic patients in the Asia-Pacific countries. We conducted a thorough literature search of the MEDLINE and EMBASE from the inception of these databases to August 2013, supplemented by an additional manual search using reference lists from research studies, meta-analyses and review articles as retrieved by the electronic databases. A total of nine randomized controlled trials were identified and described in this article. It was found that DPP-4 inhibitors and GLP-1 analogues were in general effective as add-on therapies to existing sulphonylurea therapies, achieving HbA1c reductions by a magnitude of 0.59-0.90% and 0.77-1.62%, respectively. Few adverse events including hypoglycaemic attacks were reported. Therefore, these two new drug classes represent novel therapies with great potential to be major therapeutic options. Future larger-scale research should be conducted among other Asia-Pacific region to evaluate their efficacy in other ethnic groups. Topics: Asia; Comparative Effectiveness Research; Diabetes Mellitus, Type 2; Dipeptidyl-Peptidase IV Inhibitors; Glucagon-Like Peptide 1; Humans; Hypoglycemic Agents; Pacific Ocean; Sulfonylurea Compounds | 2014 |
Pronounced reduction of postprandial glucagon by lixisenatide: a meta-analysis of randomized clinical trials.
Glucagon-like peptide-1 (GLP-1) receptor agonists improve islet function and delay gastric emptying in patients with type 2 diabetes mellitus (T2DM). This meta-analysis aimed to investigate the effects of the once-daily prandial GLP-1 receptor agonist lixisenatide on postprandial plasma glucose (PPG), glucagon and insulin levels.. Six randomized, placebo-controlled studies of lixisenatide 20 µg once daily were included in this analysis: lixisenatide as monotherapy (GetGoal-Mono), as add-on to oral antidiabetic drugs (OADs; GetGoal-M, GetGoal-S) or in combination with basal insulin (GetGoal-L, GetGoal-Duo-1 and GetGoal-L-Asia). Change in 2-h PPG and glucose excursion were evaluated across six studies. Change in 2-h glucagon and postprandial insulin were evaluated across two studies. A meta-analysis was performed on least square (LS) mean estimates obtained from analysis of covariance (ANCOVA)-based linear regression.. Lixisenatide significantly reduced 2-h PPG from baseline (LS mean difference vs. placebo: -4.9 mmol/l, p < 0.001) and glucose excursion (LS mean difference vs. placebo: -4.5 mmol/l, p < 0.001). As measured in two studies, lixisenatide also reduced postprandial glucagon (LS mean difference vs. placebo: -19.0 ng/l, p < 0.001) and insulin (LS mean difference vs. placebo: -64.8 pmol/l, p < 0.001). There was a stronger correlation between 2-h postprandial glucagon and 2-h PPG with lixisenatide than with placebo.. Lixisenatide significantly reduced 2-h PPG and glucose excursion together with a marked reduction in postprandial glucagon and insulin; thus, lixisenatide appears to have biological effects on blood glucose that are independent of increased insulin secretion. These effects may be, in part, attributed to reduced glucagon secretion. Topics: Blood Glucose; Diabetes Mellitus, Type 2; Gastric Emptying; Glucagon; Glucagon-Like Peptide 1; Glycated Hemoglobin; Humans; Hypoglycemic Agents; Insulin; Insulin Secretion; Peptides; Postprandial Period; Randomized Controlled Trials as Topic | 2014 |
Differences in the HbA1c-lowering efficacy of glucagon-like peptide-1 analogues between Asians and non-Asians: a systematic review and meta-analysis.
To compare the HbA1c-lowering efficacy of glucagon-like peptide-1 (GLP-1) analogues between Asians and non-Asians with type 2 diabetes.. We searched randomized controlled trials from MEDLINE, EMBASE, LILACS, CENTRAL and ClinicalTrials.gov. Studies described in English were included if the treatment duration was 12 weeks or more, information about ethnicity and baseline HbA1c values were available and a GLP-1 analogue was compared with a placebo. For the ethnic comparison, we divided the studies into Asian-dominant studies (≥ 50% Asian participants) and non-Asian-dominant studies (<50% Asian participants).. Among the 837 searched studies, 15 trials were included for the meta-analysis. The weighted mean difference of HbA1c with GLP-1 analogues was -1.16% [95% confidence interval (CI) -1.48, -0.85] in the Asian-dominant studies and -0.83% (95% CI -0.97, -0.70) in the non-Asian-dominant studies. The between-group difference was -0.32% (95% CI -0.64, -0.01; p = 0.04). The relative risk (RR) with 95% CIs for achieving the target HbA1c ≤ 7.0% tended to be greater in the Asian-dominant studies [RR 5.7 (3.8, 8.7)] than in the non-Asian-dominant studies [RR 2.8 (2.4, 3.3)]. Body weight changes were similar between the two groups. Hypoglycaemia tended to be more common in Asian-dominant studies (RR 2.8 [2.3, 3.5]) than in non-Asian-dominant studies (RR 1.5 [1.2, 1.8]), but severe hypoglycaemia was very rare in both groups.. GLP-1 analogues lower HbA1c more in Asian-dominant studies than in non-Asian-dominant studies. Further studies are warranted to explore the potential mechanisms of the ethnic difference. Topics: Asian People; Blood Glucose; Body Weight; Diabetes Mellitus, Type 2; Dipeptidyl-Peptidase IV Inhibitors; Exenatide; Glucagon-Like Peptide 1; Humans; Liraglutide; Peptides; Randomized Controlled Trials as Topic; Treatment Outcome; Venoms | 2014 |
GLP-1-mediated gene therapy approaches for diabetes treatment.
Glucagon-like peptide (GLP)-1 is an incretin hormone with several antidiabetic functions including stimulation of glucose-dependent insulin secretion, increase in insulin gene expression and beta-cell survival. Despite the initial technical difficulties and profound inefficiency of direct gene transfer into the pancreas that seriously restricted in vivo gene transfer experiments with GLP-1, recent exploitation of various routes of gene delivery and alternative means of gene transfer has permitted the detailed assessment of the therapeutic efficacy of GLP-1 in animal models of type 2 diabetes (T2DM). As a result, many clinical benefits of GLP-1 peptide/analogues observed in clinical trials involving induction of glucose tolerance, reduction of hyperglycaemia, suppression of appetite and food intake linked to weight loss have been replicated in animal models using gene therapy. Furthermore, GLP-1-centered gene therapy not only improved insulin sensitivity, but also reduced abdominal and/or hepatic fat associated with obesity-induced T2DM with drastic alterations in adipokine profiles in treated subjects. Thus, a comprehensive assessment of recent GLP-1-mediated gene therapy approaches with detailed analysis of current hurdles and resolutions, is discussed. Topics: Adenoviridae; Animals; Dependovirus; Diabetes Mellitus, Type 2; Genetic Therapy; Genetic Vectors; Glucagon-Like Peptide 1; Humans; Pancreas; Promoter Regions, Genetic; Virus Integration | 2014 |
Cardiovascular actions of GLP-1 and incretin-based pharmacotherapy.
Incretin-based therapy became recently available as antihyperglycemic treatment for patients with type 2 diabetes (T2DM). Incretin therapy comprises glucagon-like peptide receptor agonists (GLP-1RA) and dipeptidyl-peptidase 4 inhibitors (DPP4-I): these classes of drugs not only have the ability to reduce blood glucose, but also can exert several cardioprotective effects. They have been shown to positively influence some risk factors for cardiovascular disease (CVD), to improve endothelial function, and to directly affect cardiac function. For these reasons incretins are considered not only antidiabetic drugs, but also cardiovascular effective. The first clinical trials aimed to demonstrate the safety of DPP4 inhibitors have been recently published: their clinical significance will be discussed in light of the prior experimental findings. Topics: Blood Glucose; Blood Pressure; Cardiovascular Diseases; Diabetes Mellitus, Type 2; Dipeptidyl-Peptidase IV Inhibitors; Endothelium, Vascular; Female; Glucagon-Like Peptide 1; Glucagon-Like Peptide-1 Receptor; Humans; Hypoglycemic Agents; Incretins; Inflammation; Lipid Metabolism; Male; Myocytes, Cardiac; Receptors, Glucagon | 2014 |
At the centennial of Michaelis and Menten, competing Michaelis-Menten steps explain effect of GLP-1 on blood-brain transfer and metabolism of glucose.
Glucagon-like peptide-1 (GLP-1) is a potent insulinotropic incretin hormone with both pancreatic and extrapancreatic effects. Studies of GLP-1 reveal significant effects in regions of brain tissue that regulate appetite and satiety. GLP-1 mimetics are used for the treatment of type 2 diabetes mellitus. GLP-1 interacts with peripheral functions in which the autonomic nervous system plays an important role, and emerging pre-clinical findings indicate a potential neuroprotective role of the peptide, for example in models of stroke and in neurodegenerative disorders. A century ago, Leonor Michaelis and Maud Menten described the steady-state enzyme kinetics that still apply to the multiple receptors, transporters and enzymes that define the biochemical reactions of the brain, including the glucose-dependent impact of GLP-1 on blood-brain glucose transfer and metabolism. This MiniReview examines the potential of GLP-1 as a molecule of interest for the understanding of brain energy metabolism and with reference to the impact on brain metabolism related to appetite and satiety regulation, stroke and neurodegenerative disorders. These effects can be understood only by reference to the original formulation of the Michaelis-Menten equation as applied to a chain of kinetically controlled steps. Indeed, the effects of GLP-1 receptor activation on blood-brain glucose transfer and brain metabolism of glucose depend on the glucose concentration and relative affinities of the steps both in vitro and in vivo, as in the pancreas. Topics: Animals; Biological Transport; Blood-Brain Barrier; Brain; Diabetes Mellitus, Type 2; Glucagon-Like Peptide 1; Glucagon-Like Peptide-1 Receptor; Glucose; Humans; Hypoglycemic Agents; Neurodegenerative Diseases; Receptors, Glucagon; Stroke | 2014 |
Glucagon-like peptide-1 receptor agonists for the treatment of type 2 diabetes: differences and similarities.
Glucagon-like peptide-1 (GLP-1) is a gastrointestinal hormone, secreted in response to ingestion of nutrients, and has important effects on several of the pathophysiological features of type 2 diabetes (T2D). The effects include potentiation of insulin secretion, suppression of glucagon secretion, slowing of gastric emptying and suppression of appetite. In circulation, GLP-1 has a half-life of approximately 2min due to rapid degradation by the enzyme dipeptidyl peptidase 4 (DPP-4). Because of this short half-life GLP-1 receptor (GLP-1R) agonists, resistant to degradation by DPP-4 have been developed. At the moment four different compounds are available for the treatment of T2D and many more are in clinical development. These compounds, although all based on the effects of native GLP-1, differ with regards to structure, pharmacokinetics and size, which ultimately leads to different clinical effects. This review gives an overview of the clinical data on GLP-1R agonists that have been compared in head-to-head studies and focuses on relevant differences between the compounds. Highlighting these similarities and differences could be beneficial for physicians in choosing the best treatment strategy for their patients. Topics: Diabetes Mellitus, Type 2; Dipeptidyl-Peptidase IV Inhibitors; Exenatide; Gastric Emptying; Glucagon-Like Peptide 1; Glucagon-Like Peptide-1 Receptor; Humans; Hypoglycemic Agents; Liraglutide; Peptides; Receptors, Glucagon; Satiety Response; Venoms | 2014 |
Insulin degludec/liraglutide: innovation-driven combination for advancement in diabetes therapy.
Existing pharmacological therapies with basal insulins are limited by weight gain and hypoglycemia, while those with glucagon-like peptide-1 (GLP-1) receptor agonists (RAs) are limited by issues of efficacy when used alone. However, when used in combination they show a complementarity of action, in terms of reducing the incidence of hypoglycemia while providing sufficient glycemic control, that might help counterbalance their individual limitations. Clinical trials have demonstrated better efficacy and safety profile of this combination. Insulin degludec/liraglutide (IDegLira) is a once-daily fixed-dose combination of ultra-long-acting basal insulin degludec (IDeg) and GLP-1 RA, liraglutide.. We reviewed published data regarding chemistry, pharmacokinetics, pharmacodynamics, clinical efficacy and safety of IDeg, liraglutide and the co-formulation. Literature was searched from the electronic medical database PubMed up to December 2013.. Preliminary studies on IDegLira indicate improved overall glycemic control, better safety profile with reduction in bodyweight and low rate of hypoglycemia compared to IDeg but higher rates of hypoglycemia than liraglutide therapy alone. Further, simplicity of fixed-dose combination offers an additional advantage of improved treatment adherence. IDegLira might be used similar to basal insulins in the current treatment algorithms, but with a greater preference for initiation instead of two or more oral drugs. Topics: Animals; Biomarkers; Blood Glucose; Diabetes Mellitus, Type 2; Drug Combinations; Glucagon-Like Peptide 1; Glycated Hemoglobin; Humans; Hypoglycemic Agents; Insulin, Long-Acting; Liraglutide; Treatment Outcome | 2014 |
The sum of many parts: potential mechanisms for improvement in glucose homeostasis after bariatric surgery.
Bariatric surgery has emerged as the most durably effective treatment of type 2 diabetes (DM). However, the mechanisms governing improvement in glucose homeostasis have yet to be fully elucidated. In this review we discuss the various types of surgical interventions and the multitude of factors that potentially mediate the effects on glycemia, such as altered delivery of nutrients to the distal ileum, duodenal exclusion, gut hormone changes, bile acid reabsorption, and amino acid metabolism. Accumulating evidence that some of these changes seem to be independent of weight loss questions the rationale of using body mass index as the major indication for surgery in diabetic patients. Understanding the complex mechanisms and interactions underlying improved glycemic control could lead to novel therapeutic targets and would also allow for greater individualization of therapy and optimization of surgical outcomes. Topics: Bariatric Surgery; Body Mass Index; Caloric Restriction; Diabetes Mellitus, Type 2; Female; Glucagon-Like Peptide 1; Glucose; Glycated Hemoglobin; Homeostasis; Humans; Incretins; Insulin Resistance; Male; Obesity, Morbid; Peptide YY; Randomized Controlled Trials as Topic; Remission Induction; Treatment Outcome; Weight Loss | 2014 |
Can GLP-1 preparations be used in children and adolescents with diabetes mellitus?
The number of young diabetics is increasing and therapeutic options for these patients are limited. Glucagon-like peptide-1 (GLP-1) is secreted from the gut after meals and enhances glucose-induced insulin secretion, inhibits glucagon secretion, suppresses appetite, and delays the gastric-emptying rate. GLP-1 analogs are already widely used in the adult population to improve glycemic control and induce weight loss in overweight subjects with type 2 diabetes. The glucose-lowering effects resulting from the inhibition of glucagon secretion and the gastric-emptying rate could be of clinical importance in type 1 diabetes. In this article we review clinical data regarding the use of GLP-1 receptor agonists in youth and address the potential benefits and safety aspects of these compounds. Large scale clinical trials are still needed in the pediatric population. Topics: Adolescent; Adult; Child; Diabetes Mellitus; Diabetes Mellitus, Type 1; Diabetes Mellitus, Type 2; Female; Gastric Emptying; Glucagon; Glucagon-Like Peptide 1; Glucagon-Like Peptide-1 Receptor; Glycated Hemoglobin; Humans; Hypoglycemic Agents; Insulin; Insulin Secretion; Liraglutide; Male; Pediatric Obesity; Randomized Controlled Trials as Topic; Receptors, Glucagon | 2014 |
Bile acid sequestrants in type 2 diabetes: potential effects on GLP1 secretion.
Bile acid sequestrants have been used for decades for the treatment of hypercholesterolaemia. Sequestering of bile acids in the intestinal lumen interrupts enterohepatic recirculation of bile acids, which initiate feedback mechanisms on the conversion of cholesterol into bile acids in the liver, thereby lowering cholesterol concentrations in the circulation. In the early 1990s, it was observed that bile acid sequestrants improved glycaemic control in patients with type 2 diabetes. Subsequently, several studies confirmed the finding and recently - despite elusive mechanisms of action - bile acid sequestrants have been approved in the USA for the treatment of type 2 diabetes. Nowadays, bile acids are no longer labelled as simple detergents necessary for lipid digestion and absorption, but are increasingly recognised as metabolic regulators. They are potent hormones, work as signalling molecules on nuclear receptors and G protein-coupled receptors and trigger a myriad of signalling pathways in many target organs. The most described and well-known receptors activated by bile acids are the farnesoid X receptor (nuclear receptor) and the G protein-coupled cell membrane receptor TGR5. Besides controlling bile acid metabolism, these receptors are implicated in lipid, glucose and energy metabolism. Interestingly, activation of TGR5 on enteroendocrine L cells has been suggested to affect secretion of incretin hormones, particularly glucagon-like peptide 1 (GLP1 (GCG)). This review discusses the role of bile acid sequestrants in the treatment of type 2 diabetes, the possible mechanism of action and the role of bile acid-induced secretion of GLP1 via activation of TGR5. Topics: Allylamine; Animals; Bile Acids and Salts; Blood Glucose; Colesevelam Hydrochloride; Diabetes Mellitus, Type 2; Energy Metabolism; Fibroblast Growth Factors; Glucagon-Like Peptide 1; Humans; Lipid Metabolism; Receptors, Cytoplasmic and Nuclear; Receptors, G-Protein-Coupled | 2014 |
The effect of a dual combination of noninsulin antidiabetic drugs on lipids: a systematic review and network meta-analysis.
As an ever widening array of anti-hyperglycemic agents are now available, the effect of these drugs on lipids is increasingly complex and controversial. The present meta-analysis was designed to clarify the effect of a dual combination of noninsulin anti-hyperglycemic agents on lipids in type 2 diabetes.. Randomized controlled trials comparing different dual combinations of antidiabetic drugs were identified by searching PubMed, Cochrane Library, and Embase. Study selection, data abstraction and quality assessment were carried out by two reviewers independently. Change in low-density lipoprotein (LDL), high-density lipoprotein (HDL), triglyceride and total cholesterol were pooled by both traditional meta-analysis and network meta-analysis.. Eighteen studies with a total of 10,222 patients were included. Network meta-analysis suggested that metformin + dipeptidyl peptidase-4 inhibitors (DPP-4) (LDL cholesterol: -0.19 mmol/L; HDL cholesterol: 0.06 mmol/L; triglycerides: -0.73 mmol/L; total cholesterol: -0.4 mmol/L) and metformin + glucagon-like peptide-1 (GLP-1) agonist (LDL cholesterol: -0.3 mmol/L; HDL cholesterol: 0.06 mmol/L; triglycerides: -0.64 mmol/L; total cholesterol: -0.5 mmol/L) were associated with relatively larger beneficial effects on the lipid profile among all combinations. Compared with metformin + thiazolidinedione, metformin + GLP-1 agonist (mean difference: -0.38; 95% confidence interval [CI]: -0.66 to -0.10) significantly decreased LDL cholesterol. Metformin + thiazolidinedione showed a larger increase than metformin + sulfonylurea in HDL cholesterol (mean difference: 0.1; 95% CI: 0.01 to 0.21).. The effect of a dual combination of noninsulin anti-hyperglycemic agents on lipids is moderate to small, with metformin + DPP-4 inhibitor and metformin + GLP-1 agonist showing consistent beneficial effects on LDL cholesterol, HDL cholesterol, triglycerides and total cholesterol. Future trials are needed to confirm these findings. Topics: Biomarkers; Cholesterol; Diabetes Mellitus, Type 2; Dipeptidyl-Peptidase IV Inhibitors; Drug Therapy, Combination; Glucagon-Like Peptide 1; Humans; Hypoglycemic Agents; Lipoproteins, HDL; Lipoproteins, LDL; Metformin; Models, Statistical; Randomized Controlled Trials as Topic; Sulfonylurea Compounds; Thiazolidinediones; Treatment Outcome; Triglycerides | 2014 |
Vildagliptin , a DPP-4 inhibitor for the twice-daily treatment of type 2 diabetes mellitus with or without metformin.
Dipeptidyl peptidase-4 inhibitors increase circulating levels of glucagon-like peptide 1 (GLP-1) and glucose dependent insulinotropic polypeptide regulating glucose-dependent insulin secretion. In addition, GLP-1 suppresses glucagon secretion, delays gastric emptying and increases satiety. The combination of vildagliptin with the biguanide metformin is of particular interest because of its complementary mode of action, addressing insulin resistance, alpha- and beta cell function in the islet of the pancreas.. Because of the abundance of data supporting the use of vildagliptin alone and in combination with metformin, the present paper aims at giving an overview on the current evidence for its use in patients with type 2 diabetes mellitus.. The data suggest that vildagliptin offers similar glycemic control compared to sulfonylureas and thiazolidinediones, while having the benefit of being associated with fewer cases of hypoglycemia and less body weight gain. There is increasing evidence that compared with sulfonylureas, vildagliptin has favorable effects on pancreatic alpha- and beta-cell function. Vildagliptin in combination with metformin, improve glycemic control with a favorable safety and tolerability profile, making it an attractive therapeutic option in patients where metformin monotherapy alone is not sufficient. Topics: Adamantane; Animals; Blood Glucose; Diabetes Mellitus, Type 2; Dipeptidyl-Peptidase IV Inhibitors; Drug Administration Schedule; Drug Therapy, Combination; Glucagon-Like Peptide 1; Humans; Insulin; Metformin; Nitriles; Pyrrolidines; Treatment Outcome; Vildagliptin | 2014 |
Insulin and glucagon-like peptide receptor agonist (GLP 1 RA) combinations.
This review analyses a recent advance in diabetes pharmacotherapeutics: the combination of insulin and glucagon-like peptide 1 receptor agonists (GLP 1 RA). It describes the rationale for such a combination, and discusses the impact of such therapy on glycaemic control. The paper also assesses other benefits of the combination, and provides a practical framework for pragmatic, rational use of this treatment. Topics: Blood Glucose; Body Weight; Diabetes Mellitus, Type 2; Drug Therapy, Combination; Glucagon-Like Peptide 1; Humans; Hypoglycemic Agents; Insulin | 2014 |
Blood pressure effects of glucagon-like peptide 1 analogues and sodium glucose transporter 2 inhibitors.
The growing number of obese patients with a high risk of developing hypertension and type 2 diabetes mellitus requires several drugs to treat all the associated morbidities. Ideally, one drug would help to tackle several health problems at the same time. We review available information on the blood pressure-reducing effects of the new antidiabetic drug classes, glucagon-like peptide 1 analogues and sodium glucose transporter 2 inhibitors.. Blood pressure reduction with glucagon-like peptide 1 analogues or sodium glucose transporter 2 inhibitors ranges between 1 and 7 mmHg, both systolic and diastolic. As these drugs have not been sufficiently investigated in studies with office or ambulatory blood pressure as the primary efficacy measure or in prespecified hypertensive patient populations, their true efficacy in reducing blood pressure remains unclear. These studies are needed because the blood pressure-lowering effects of metabolic drugs may help to improve the clinical management of hypertensive patients with type 2 diabetes mellitus.. Obese patients with type 2 diabetes mellitus and difficult to control arterial hypertension represent a clinically important patient group at high cardiovascular risk that may profit from combined cardiovascular and metabolic actions of a drug. Topics: Animals; Antihypertensive Agents; Arterial Pressure; Blood Glucose; Diabetes Mellitus, Type 2; Drug Design; Glucagon-Like Peptide 1; Humans; Hypertension; Hypoglycemic Agents; Obesity; Risk Factors; Sodium-Glucose Transporter 2; Sodium-Glucose Transporter 2 Inhibitors; Treatment Outcome | 2014 |
Potential impact of dipeptidyl peptidase-4 inhibitors on cardiovascular pathophysiology in type 2 diabetes mellitus.
Cardiovascular (CV) disease remains the major cause of mortality and morbidity in patients with type 2 diabetes mellitus (T2DM). The pathogenesis of CV disease in T2DM is complex and multifactorial, and includes abnormalities in endothelial cells, vascular smooth muscle cells, myocardium, platelets, and the coagulation cascade. Dipeptidyl peptidase-4 (DPP-4) inhibitors are a newer class of agents that act by potentiating the action of glucagon-like peptide-1 (GLP-1) and glucose-dependent insulinotropic polypeptide. This review summarizes CV disease pathophysiology in T2DM and the potential effect of DPP-4 inhibitors on CV risk in patients with T2DM. Preclinical and small observational studies and post hoc analyses of clinical trial data suggest that DPP-4 inhibitors may have beneficial CV effects. Some effects of DPP-4 inhibitors are GLP-1 dependent, whereas others may be due to GLP-1-independent actions of DPP-4 inhibitors. Analyses of major adverse CV events occurring during clinical development of DPP-4 inhibitors found no increased risk of CV events or mortality and even a potential reduction in CV events. Two large CV outcome trials have been completed and report that saxagliptin and alogliptin did not increase or decrease adverse CV outcomes in patients with T2DM and CV disease or at high risk for adverse CV events. More patients in the saxagliptin group than in the placebo group were hospitalized for heart failure, and there was a similar numerically increased risk of hospitalization for heart failure with alogliptin; however, the risk was not significantly greater compared with placebo. Dipeptidyl peptidase-4 inhibitors may affect some of the pathologic processes involved in the increased CV risk inherent in T2DM. Topics: Animals; Blood Platelets; Cardiovascular Diseases; Clinical Trials as Topic; Diabetes Mellitus, Type 2; Dipeptidyl-Peptidase IV Inhibitors; Drug Evaluation, Preclinical; Endothelial Cells; Glucagon-Like Peptide 1; Humans; Hypoglycemic Agents; Incretins; Lipoproteins; Muscle, Smooth, Vascular; Myocardium; Risk Factors | 2014 |
GLP-1(28-36)amide, the Glucagon-like peptide-1 metabolite: friend, foe, or pharmacological folly?
The glucagon-like peptide-1 (GLP-1) axis has emerged as a major therapeutic target for the treatment of type 2 diabetes. GLP-1 mediates its key insulinotropic effects via a G-protein coupled receptor expressed on β-cells and other pancreatic cell types. The insulinotropic activity of GLP-1 is terminated via enzymatic cleavage by dipeptidyl peptidase-4. Until recently, GLP-1-derived metabolites were generally considered metabolically inactive; however, accumulating evidence indicates some have biological activity that may contribute to the pleiotropic effects of GLP-1 independent of the GLP-1 receptor. Recent reports describing the putative effects of one such metabolite, the GLP-1-derived nonapeptide GLP-1(28-36) amide, are the focus of this review. Administration of the nonapeptide elevates cyclic adenosine monophosphate (cAMP) and activates protein kinase A, β-catenin, and cAMP response-element binding protein in pancreatic β-cells and hepatocytes. In stressed cells, the nonapeptide targets the mitochondria and, via poorly defined mechanisms, helps to maintain mitochondrial membrane potential and cellular adenosine triphosphate levels and to reduce cytotoxicity and apoptosis. In mouse models of diet-induced obesity, treatment with the nonapeptide reduces weight gain and ameliorates associated pathophysiology, including hyperglycemia, hyperinsulinemia, and hepatic steatosis. Nonapeptide administration in a streptozotocin-induced model of type 1 diabetes also improves glucose disposal concomitant with elevated insulin levels and increased β-cell mass and proliferation. Collectively, these results suggest some of the beneficial effects of GLP-1 receptor analogs may be mediated by the nonapeptide. However, the concentrations required to elicit some of these effects are in the micromolar range, leading to reservations about potentially related therapeutic benefits. Moreover, although controversial, concerns have been raised about the potential for incretin-based therapies to promote pancreatitis and pancreatic and thyroid cancers. The effects ascribed to the nonapeptide make it a potential contributor to such outcomes, raising additional questions about its therapeutic suitability. Notwithstanding, the nonapeptide, like other GLP-1 metabolites, appears to be biologically active. Increasing understanding of such noncanonical GLP-1 activities should help to improve future incretin-based therapeutics. Topics: Animals; Diabetes Mellitus, Experimental; Diabetes Mellitus, Type 1; Diabetes Mellitus, Type 2; Glucagon-Like Peptide 1; Humans; Peptide Fragments | 2014 |
Beyond glycemic control: cardiovascular effects of incretin-based therapies.
As cardiovascular (CV) disease remains the major cause of mortality and morbidity in type 2 diabetes mellitus, reducing macrovascular complications has been a major target of antiglycemic therapies. Emerging evidence suggests that incretin-based therapies are safe and may provide CV and cerebrovascular (CBV) benefits beyond those attributable to glycemic control, making the class an attractive therapeutic option. However, the mechanisms whereby the various classes of incretin-based therapies exert CV and CBV benefits may be distinct and may not necessarily lead to similar outcomes. In this chapter, we will discuss the potential mechanisms and current understanding of CV and CBV benefits of native glucagon-like peptide (GLP)-1, GLP-1 receptor agonists and analogues, and of dipeptidyl peptidase-4 inhibitor therapies as a means to better understand differences in safety and efficacy. Topics: Blood Glucose; Blood Pressure; Cardiotonic Agents; Cardiovascular Diseases; Diabetes Mellitus, Type 2; Dipeptidyl-Peptidase IV Inhibitors; Glucagon-Like Peptide 1; Glucagon-Like Peptide-1 Receptor; Heart; Humans; Incretins; Peptide Fragments; Receptors, Glucagon | 2014 |
Effects of glucagon like peptide-1 to mediate glycemic effects of weight loss surgery.
To date, weight loss surgeries are the most effective treatment for obesity and glycemic control in patients with type 2 diabetes. Roux-en-Y gastric bypass surgery (RYGB) and sleeve gastrectomy (SG), two widely used bariatric procedures for the treatment of obesity, induce diabetes remission independent of weight loss while glucose improvement after adjustable gastric banding (AGB) is proportional to the amount of weight loss. The immediate, weight-loss independent glycemic effect of gastric bypass has been attributed to postprandial hyperinsulinemia and an enhanced incretin effect. The rapid passage of nutrients into the intestine likely accounts for significantly enhanced glucagon like-peptide 1 (GLP-1) secretion, and postprandial hyperinsulinemia after GB is typically attributed to the combined effects of elevated glucose and GLP-1. For this review we focus on the beneficial effects of the three most commonly performed bariatric procedures, RYGB, SG, and AGB, on glucose metabolism and diabetes remission. Central to this discussion will be the extent to which the effects of surgery are mediated by GLP-1. Better understanding of these mechanisms could provide insight to development of novel therapeutic strategies for treatment of diabetes as well as refinement of surgical techniques. Topics: Bariatric Surgery; Blood Glucose; Diabetes Mellitus, Type 2; Female; Glucagon-Like Peptide 1; Humans; Male; Obesity; Weight Loss | 2014 |
Incretins: their physiology and application in the treatment of diabetes mellitus.
Therapies targeting the action of incretin hormones have been under close scrutiny in recent years. The incretin effect has been defined as postprandial enhancement of insulin secretion by gut-derived factors. Likewise, incretin mimetics and incretin effect amplifiers are the two different incretin-based treatment strategies developed for the treatment of diabetes. Although, incretin mimetics produce effects very similar to those of natural incretin hormones, incretin effect amplifiers act by inhibiting dipeptidyl peptidase-4 (DPP-4) enzyme to increase plasma concentration of incretins and their biologic effects. Because glucagon-like peptide-1 (GLP-1) is an incretin hormone with various anti-diabetic actions including stimulation of glucose-induced insulin secretion, inhibition of glucagon secretion, hepatic glucose production and gastric emptying, it has been evaluated as a novel therapeutic agent for the treatment of type 2 diabetes mellitus (T2DM). GLP-1 also manifests trophic effects on pancreas such as pancreatic beta cell growth and differentiation. Because DPP-4 is the enzyme responsible for the inactivation of GLP-1, DPP-4 inhibition represents another potential strategy to increase plasma concentration of GLP-1 to enhance the incretin effect. Thus, anti-diabetic properties of these two classes of drugs have stimulated substantial clinical interest in the potential of incretin-based therapeutic agents as a means to control glucose homeostasis in T2DM patients. Despite this fact, clinical use of GLP-1 mimetics and DPP-4 inhibitors have raised substantial concerns owing to possible side effects of the treatments involving increased risk for pancreatitis, and C-cell adenoma/carcinoma. Thus, controversial issues in incretin-based therapies under development are reviewed and discussed in this manuscript. Topics: Animals; Diabetes Mellitus, Type 2; Dipeptidyl Peptidase 4; Dipeptidyl-Peptidase IV Inhibitors; Exenatide; Gastric Inhibitory Polypeptide; Glucagon-Like Peptide 1; Glucagon-Like Peptide-1 Receptor; Glycated Hemoglobin; Humans; Hypoglycemic Agents; Incretins; Insulin; Insulin Glargine; Insulin Secretion; Insulin-Secreting Cells; Insulin, Long-Acting; Peptides; Receptors, Glucagon; Venoms | 2014 |
Effect of GLP-1 based therapies on diabetic dyslipidemia.
Glucagon-like peptide-1 (GLP-1), is a hormone secreted by small intestine. Consumption of food or glucose stimulates synthesis and secretion of GLP-1 in the bloodstream, which in turn stimulates insulin secretion from pancreas and delays gastric emptying. Owing to the favorable spectrum of effects on reduction of hyperglycemia and body weight, GLP-1 mimetics are intensely pursued as therapies for the treatment of type 2 diabetes (T2DM). Even after intensive control of hyperglycemia, the propensity for cardiovascular disease cannot be totally negated in diabetic patients. A major reason for the cardiovascular disease risk in diabetic patients is underlying dyslipidemia, also termed as diabetic dyslipidemia. It is characterized by high concentrations of triglycerides and LDL cholesterol, and lowered HDL cholesterol in plasma, which are associated with hyperglycemia. Increased insulin resistance gives rise to increased free fatty acids in bloodstream, which is the main reason for the lipid changes appearing in diabetic dyslipidemia. The secondary complications like atherosclerosis and other cardiovascular diseases may be predicted with the blood concentrations of triglycerides and cholesterol, due to the correlation proven in clinic. Hence, new drugs that target diabetic dyslipidemia will always be useful in therapy. Apart from its actions on body weight and glucose, GLP-1 can also regulate cholesterol and triglycerides by numerous ways. Acute and long term treatment with either GLP-1 or its stable analogs reduced fasting as well as postprandial lipids in healthy as well as T2DM patients. GLP-1R signaling reduces VLDL-TG production rate from liver, reduces hepatic TG content by modulating key enzymes of lipid metabolism in liver, and impairs hepatocyte de novo lipogenesis and β-oxidation. GLP-1 can also modulate reverse cholesterol transport. Apart from these direct effects on lipid metabolism, GLP-1 also reduces atherosclerotic events by inhibiting expression of atherogenic inflammatory mediators, suppressing smooth muscle cell proliferation and stimulating NO production. This review mainly deliberates the association of GLP-1 in lipid regulation via lipid absorption, hepatic cholesterol metabolism, reverse cholesterol transport and progression of atherosclerosis. Topics: Anticholesteremic Agents; Body Weight; Cholesterol; Coronary Artery Disease; Diabetes Mellitus, Type 2; Diabetic Angiopathies; Dyslipidemias; Glucagon-Like Peptide 1; Glucagon-Like Peptide-1 Receptor; Humans; Insulin Resistance; Lipid Metabolism; Receptors, Glucagon; Risk Factors; Signal Transduction; Treatment Outcome; Triglycerides | 2014 |
[Combined treatment of insulin and GLP-1 analogs: what do we expect?].
Type 2 diabetes mellitus is a progressive and heterogeneous disease. The decrease in insulin secretion by pancreatic beta cells and the increase of glucagon secretion by pancreatic beta cells, are the two major pathophysiologic characteristics. The majority of type 2 diabetics will therefore require insulin in the evolution of their disease, with weight gain and hypoglycaemia as side effects. GLP-1 analogs are effective therapeutic alternatives due to their actions on glucagon and insulin secretion, on satiety and gastric emptying. For patients inadequately controlled with conventional antidiabetics, GLP-1 analogs, introduced as an alternative or in combination with insulin, can prevent or reduce the side effects associated with insulin. Indeed, the risk of hypoglycaemia is reduced and the vicious circle of weight gain secondary to insulin/need to increase insulin doses is limited. Topics: Diabetes Mellitus, Type 2; Drug Therapy, Combination; Glucagon-Like Peptide 1; Humans; Hypoglycemic Agents; Incretins; Insulin; Molecular Targeted Therapy | 2014 |
Cost effectiveness of liraglutide in type II diabetes: a systematic review.
As novel treatments for type II diabetes enter the market, there is a need to assess their long-term clinical and economic outcomes against currently available treatment alternatives. Objective compilation and evaluation of current pharmacoeconomic evidence can assist payers and decision makers in determining the appropriate place in therapy of a new medication.. Our objective was to review the existing pharmacoeconomic literature evaluating the cost effectiveness and overall costs of treatment associated with liraglutide in type II diabetes.. Medical literature indexed in MEDLINE, EMBASE, PsycINFO, CINAHL, and EconLit through 1 June 2014 was searched.. Full-text, English-language cost-effectiveness, cost-utility, and other cost analyses in type II diabetes that compared liraglutide to one or more anti-diabetic agents were included. Initial screening was based on relevance of titles and abstracts followed by examination of the study methods of each remaining manuscript. Studies conducting original pharmacoeconomic analyses were chosen for inclusion.. Articles meeting the inclusion criteria were retrieved, and information on the study design and results was abstracted. Abstracted data elements were chosen and assessed based on the authors' experience as well as criteria set forth by the International Society for Pharmacoeconomics and Outcomes Research (ISPOR) Health Economic Evaluation Publication Guidelines Task Force. Additionally, reported incremental cost-effectiveness ratios (ICERs) and selected sensitivity analysis results were converted to $US, year 2012 values, in order to facilitate comparison across studies.. A total of six cost studies and seven cost-utility studies were identified for inclusion. Across cost studies, liraglutide treatment resulted in costs ranging from a loss of $US2,730 (liraglutide 1.8 mg vs. sitagliptin; pharmacy costs only) over a 1-year time horizon to a savings of $US9,367 (liraglutide 1.8 mg vs. glimepiride; diabetes-related complication costs only) over a 30-year time horizon. Cost-utility analysis results reported base-case ICERs ranging from $US15,774 (vs. glimepiride) to $US40,128 (vs. rosiglitazone) per quality-adjusted life-year (QALY) ($US, year 2012) for liraglutide 1.2 mg and $US8,497 (vs. exenatide) to $US66,031 (vs. rosiglitazone)/QALY ($US, year 2012) for liraglutide 1.8 mg. Estimates were most sensitive to variations in time horizon and cardiovascular complication rates. Based on frequently cited, country-specific cost-utility thresholds, liraglutide was determined to have a probability of being cost effective of between 58 % (liraglutide 1.8 mg vs. sitagliptin) and 93 % (liraglutide 1.2 mg vs. glimepiride).. Weaknesses of included studies related primarily to study model inputs that assumed long-term morbidity and mortality benefits in favor of liraglutide based on improvements in clinical biomarkers observed in short-term clinical trials. The exclusion of drug acquisition costs in two identified cost studies as well as the assumed lifetime duration of treatment with liraglutide in several cost-utility studies were also identified as weaknesses. The authors' review was limited by the possibility of incomplete literature retrieval, unintended omission of relevant data elements, and comparison of costs and ICERs generated from healthcare systems from differing countries.. The current literature presents liraglutide as a cost-effective adjunct treatment for type II diabetes that may also be associated with a reduction in diabetes-related complication costs; however, ICER values are largely dependent on assumptions regarding the benefits of long-term liraglutide treatment and the time horizon of the analysis. Real-world use may make liraglutide unattractive from a payer and policy-maker perspective. Topics: Cost-Benefit Analysis; Diabetes Mellitus, Type 2; Drug Costs; Glucagon-Like Peptide 1; Health Care Costs; Humans; Hypoglycemic Agents; Liraglutide | 2014 |
Comparison of GLP-1 analogues versus sitagliptin in the management of type 2 diabetes: systematic review and meta-analysis of head-to-head studies.
Incretin-based therapies which include glucagon-like peptide-1 (GLP-1) receptor agonists and dipeptidyl peptidase-4 (DPP-4) inhibitors are recommended by several practice guidelines as second-line agents for add-on therapy to metformin in patients with type 2 diabetes (T2DM) who do not achieve glycemic control with metformin plus lifestyle interventions alone. The purpose of this study is to perform a systematic review with meta-analysis of existing head to head studies to compare the efficacy and safety of GLP-1 analogues with DPP-4 inhibitors.. We performed a systematic review and meta-analysis of head-to-head studies to compare GLP-1 analogues with DPP-4 inhibitors in the management of type 2 diabetes. A random effects model was selected to perform the meta-analyses, results were expressed as weighted mean differences for continuous outcomes and relative risks for dichotomous outcomes, both with 95% confidence intervals, and with I2 values and P values as markers of heterogeneity.. Four head-to-head randomized controlled studies with 1755 patients were included. Compared to sitagliptin, GLP-1 analogues are more effective in reducing HbA1C (weight mean difference -0.41%, 95% CI -0.51 to -0.31) and body weight (weight mean difference -1.55 kg, 95% CI -1.98 to -1.12). Conversely, GLP-1 analogues are associated with a higher incidence of gastrointestinal adverse events compared to sitagliptin: nausea (relative risk 3.14, 95% CI 2.15 to 4.59), vomiting (relative risk 2.60, 95% CI 1.48 to 4.56), diarrhea (relative risk 1.82, 95% CI 1.24 to 2.69), and constipation (relative risk 2.50, 95% CI 1.33 to 4.70).. The result of this meta-analysis demonstrates that compared to sitagliptin, GLP-1 analogues are more effective for glycemic control and weight loss, but have similar efficacy in reducing blood pressure and lipid parameters, however, GLP-1 analogues are associated with a higher incidence of gastrointestinal adverse events and a similar incidence of hypoglycemia compared to sitagliptin. Topics: Blood Glucose; Blood Pressure; Body Weight; Diabetes Mellitus, Type 2; Fasting; Glucagon-Like Peptide 1; Glycated Hemoglobin; Humans; Lipids; Pyrazines; Randomized Controlled Trials as Topic; Sitagliptin Phosphate; Treatment Outcome; Triazoles | 2014 |
Use of incretin-based therapy in hospitalized patients with hyperglycemia.
Hyperglycemia is common in hospitalized patients with and without prior history of diabetes and is an independent marker of morbidity and mortality in critically and noncritically ill patients. Tight glycemic control using insulin has been shown to reduce cardiac morbidity and mortality in hospitalized patients, but it also results in hypoglycemic episodes, which have been linked to poor outcomes. Thus, alternative treatment options that can normalize blood glucose levels without undue hypoglycemia are being sought. Incretin-based therapies, such as glucagon-like peptide (GLP)-1 receptor agonists (RAs) and dipeptidyl peptidase (DPP)-4 inhibitors, may have this potential.. A PubMed database was searched to find literature describing the use of incretins in hospital settings. Title searches included the terms "diabetes" (care, management, treatment), "hospital," "inpatient," "hypoglycemia," "hyperglycemia," "glycemic," "incretin," "dipeptidyl peptidase-4 inhibitor," "glucagon-like peptide-1," and "glucagon-like peptide-1 receptor agonist.". The preliminary research experience with native GLP-1 therapy has shown promise, achieving improved glycemic control with a low risk of hypoglycemia, counteracting the hyperglycemic effects of stress hormones, and improving cardiac function in patients with heart failure and acute ischemia. Large, randomized controlled clinical trials are necessary to determine whether these favorable results will extend to the use of GLP-1 RAs and DPP-4 inhibitors.. This review offers hospitalist physicians and healthcare providers involved in inpatient diabetes care a pathophysiologic-based approach for the use of incretin agents in patients with hyperglycemia and diabetes, as well as a summary of benefits and concerns of insulin and incretin-based therapy in the hospital setting. Topics: Diabetes Mellitus, Type 2; Dipeptidyl-Peptidase IV Inhibitors; Glucagon-Like Peptide 1; Glucagon-Like Peptide-1 Receptor; Humans; Hyperglycemia; Hypoglycemic Agents; Incretins | 2014 |
GLP-1: benefits beyond pancreas.
Glucagon-like peptide 1 (GLP-1) is an intestinal hormone secreted after the ingestion of various nutrients. The main role of GLP-1 is to stimulate insulin secretion in a glucose-dependent manner. However, the expression of GLP-1 receptor was found to be expressed in a variety of tissues beyond pancreas such as lung, stomach, intestine, kidney, heart and brain. Beyond pancreas, a beneficial effect of GLP-1 on body weight reduction has been shown, suggesting its role for the treatment of obesity. In addition, GLP-1 has been demonstrated to reduce cardiovascular risk factors and to have a direct cardioprotective effect, fostering heart recovery after ischemic injury. Further, data from both experimental animal models and human studies have shown beneficial effect of GLP-1 on bone metabolism, either directly or indirectly on bone cells.. We review here the recent findings of the extra-pancreatic effects of GLP-1 focusing on both basic and clinical studies, thus opening future perspectives to the use of GLP-1 analogs for the treatment of disease beyond type 2 diabetes.. Finally, the GLP-1 has been demonstrated to have a beneficial effect on both vascular, degenerative diseases of central nervous system and psoriasis. Topics: Animals; Cardiovascular Diseases; Diabetes Mellitus, Type 2; Glucagon-Like Peptide 1; Humans; Obesity; Pancreas; Risk Factors | 2014 |
Assessment of the relative effectiveness and tolerability of treatments of type 2 diabetes mellitus: a network meta-analysis.
The relative effectiveness and tolerability of treatments for type 2 diabetes mellitus (T2DM) is not well understood because few randomized, controlled trials (RCTs) have compared these treatments directly. The purpose of the present study was to evaluate the relative effectiveness and tolerability of treatments of T2DM.. We performed a network meta-analysis of available RCTs with pharmacologic interventions in T2DM and compared antidiabetic drugs and combination regimens with metformin (the reference drug). Glycemic control (proportion achieving HbA1c goal) and tolerability (risk of hypoglycemia) were the primary outcomes of interest. Direct and indirect relative effects (unadjusted) were expressed as odds ratios and 95% CIs.. Eight treatments (glucagon-like peptide-1 [GLP-1] agonists plus metformin, sulfonylureas plus metformin, dipeptidyl peptidase-4 [DPP-4] inhibitors] plus metformin, colesevelan plus metformin, thiazolidinediones plus metformin, meglitinides plus metformin, α-glucosidase inhibitor plus metformin, and rosiglitazone monotherapy) outperformed metformin (direct effects). Triple combinations of GLP-1, thiazolinedione, insulin, metiglinide, or sulfonylureas added to a metformin backbone improved glycemic control (indirect effects). Higher risk of hypoglycemia was noted for sulfonylureas, α-glycosidases, and metiglinides when added to metformin (direct effects). Across indirect effects, only 17% of comparisons yielded less risk of hypoglycemia (70% were worse and 13% were comparable).. Our results point out the relative superiority of 2- and 3-drug combination regimens over metformin and summarize treatment effects and tolerability in a comprehensive manner, which adds to our knowledge regarding T2DM treatment options. Topics: Blood Glucose; Diabetes Mellitus, Type 2; Drug Therapy, Combination; Glucagon-Like Peptide 1; Glycated Hemoglobin; Humans; Hypoglycemia; Hypoglycemic Agents; Insulin; Metformin; Randomized Controlled Trials as Topic; Sulfonylurea Compounds; Thiazolidinediones; Treatment Outcome | 2014 |
The effects of GLP-1 analogues, DPP-4 inhibitors and SGLT2 inhibitors on the renal system.
Diabetic nephropathy (DN) affects an estimated 20%-40% of patients with type 2 diabetes mellitus (T2DM). Key modifiable risk factors for DN are albuminuria, anaemia, dyslipidaemia, hyperglycaemia and hypertension, together with lifestyle factors, such as smoking and obesity. Early detection and treatment of these risk factors can prevent DN or slow its progression, and may even induce remission in some patients. DN is generally preceded by albuminuria, which frequently remains elevated despite treatment in patients with T2DM. Optimal treatment and prevention of DN may require an early, intensive, multifactorial approach, tailored to simultaneously target all modifiable risk factors. Regular monitoring of renal function, including urinary albumin excretion, creatinine clearance and glomerular filtration rate, is critical for following any disease progression and making treatment adjustments. Dipeptidyl peptidase (DPP)-4 inhibitors and sodium-glucose cotransporter 2 (SGLT2) inhibitors lower blood glucose levels without additional risk of hypoglycaemia, and may also reduce albuminuria. Further investigation of the potential renal benefits of DPP-4 and SGLT2 inhibitors is underway. Topics: Albuminuria; Animals; Diabetes Mellitus, Type 2; Diabetic Nephropathies; Dipeptidyl Peptidase 4; Dipeptidyl-Peptidase IV Inhibitors; Glucagon-Like Peptide 1; Humans; Kidney; Risk Factors; Sodium-Glucose Transporter 2; Sodium-Glucose Transporter 2 Inhibitors; Treatment Outcome | 2014 |
The design and discovery of lixisenatide for the treatment of type 2 diabetes mellitus.
Lixisenatide is a once-daily short-acting glucagon-like peptide-1 (GLP-1) receptor agonist (GLP-1RA) used in the treatment of type 2 diabetes mellitus (T2DM). It is used in combination with oral antidiabetics and/or basal insulin in patients inadequately controlled on these medications and who are undergoing diet and lifestyle modification. GLP-1RAs glucose-dependently increase insulin secretion, decrease glucagon secretion, and slow gastric emptying, thereby improving glycemic control. GLP-1RAs are associated with body weight benefits and low rates of hypoglycemia which are welcome in patients with T2DM.. The authors describe the identification of GLP-1RAs as suitable targets for modification with structure-inducing probe technology to improve stability and resistance to proteolytic degradation. Clinical studies have assessed lixisenatide across > 5000 patients as a monotherapy or add-on to a variety of commonly used antidiabetic medications. These studies highlighted the effects of lixisenatide on gastric emptying, explaining its particular improvements in postprandial plasma glucose (PPG) excursions and underscoring its efficacy in combination with insulin glargine. Lixisenatide was well tolerated, with nausea and vomiting being the most frequently reported adverse events.. The once-daily administration of lixisenatide as well as its substantial sustained effect on gastric emptying and, hence, PPG excursions are all important features compared with the other GLP-1RAs. The combination of two injectables, such as basal insulin to lower fasting plasma glucose and a GLP-1RA that curtails PPG excursions, is clinically valuable and could differentiate lixisenatide from other GLP-1RAs, especially from those continuously acting GLP-1RAs with little effect on gastric emptying and PPG excursions. Topics: Animals; Blood Glucose; Clinical Trials as Topic; Diabetes Mellitus, Experimental; Diabetes Mellitus, Type 2; Drug Design; Drug Discovery; Drug Evaluation, Preclinical; Glucagon-Like Peptide 1; Glucagon-Like Peptide-1 Receptor; Humans; Hypoglycemic Agents; Peptides; Protein Binding; Receptors, Glucagon; Treatment Outcome | 2014 |
Effects of glucagon-like peptide-1 agents on left ventricular function: systematic review and meta-analysis.
The cardiovascular safety of many glucagon-like peptide-1 agents (GLP-1 agents) is unclear. In this study, we assess the effects of the GLP-1 agents on left ventricular function in patients with type 2 diabetes (T2DM) and/or cardiovascular disease (CVD).. PubMed, EMBASE, and the Cochrane Library were searched for the relevant publications up to May 2013 without restriction by language. All clinical controlled trials assessing left ventricular function and cardiovascular outcomes with the GLP-1 agents were selected for eligibility. Fourteen trials (415 patients) were identified as eligible between 1966 and 2013. Twelve of the studies were randomized controlled trials (RCT).. The results showed that GLP-1 agent treatment in patients with T2DM and/or CVD led to significantly improved regional left ventricular contractile parameters (including peak left systolic tissue velocity and strain) and global left ventricular performance (including stroke volume, ejection fraction, and left ventricular chambers) compared with patients receiving placebo.. GLP-1 agent treatment in T2DM and/or CVD patients is associated with a modest but significant increase in the odds of left ventricular contractile parameters and left ventricular performance compared with patients having received placebo, which may be indicative of additional cardiovascular benefits for these patients. Topics: Cardiovascular Diseases; Diabetes Mellitus, Type 2; Glucagon-Like Peptide 1; Hemodynamics; Humans; Hypoglycemic Agents; Randomized Controlled Trials as Topic; Ventricular Function, Left | 2014 |
Albiglutide: a new GLP-1 receptor agonist for the treatment of type 2 diabetes.
To review the pharmacology, pharmacokinetics, safety, and efficacy of albiglutide, a glucagon-like peptide-1 receptor agonist (GLP-1 RA) in type 2 diabetes (T2D).. A MEDLINE search (1950-June 2014) was conducted using the keyword albiglutide. References were reviewed to identify additional sources.. Articles evaluating pharmacokinetics, pharmacodynamics, safety, or efficacy of albiglutide were included.. Albiglutide is a long-acting GLP-1 RA that lowers glycosylated hemoglobin (A1C) and reduces weight by stimulating glucose-dependent insulin secretion, suppressing glucagon secretion, delaying gastric emptying, and promoting satiety. Albiglutide has a long half-life as a result of resistance to degradation by dipeptidyl peptidase-4 and fusion to albumin, thus allowing once-weekly dosing. Albiglutide has been studied as monotherapy and add-on therapy to metformin, sulfonylureas, thiazolidinediones, insulin glargine, and varying combinations of these agents. Clinical studies have shown albiglutide to be superior to placebo, sitagliptin, and glimepiride and noninferior to insulin glargine and insulin lispro at reducing A1C in T2D patients, with A1C changes from baseline ranging from -0.55% to -0.9%. Noninferiority was not achieved when compared to liraglutide and pioglitazone. Weight changes ranged from +0.28 to -1.21 kg. The most common side effects are upper-respiratory-tract infections, diarrhea, nausea, and injection-site reactions.. Albiglutide is the fourth GLP-1 RA approved in the United States. Advantages include once-weekly dosing and fewer gastrointestinal side effects compared with liraglutide, but it is less effective at reducing A1C and weight compared to liraglutide. It has not been compared head to head with other GLP-1 RAs. Topics: Body Weight; Clinical Trials as Topic; Diabetes Mellitus, Type 2; Glucagon-Like Peptide 1; Glucagon-Like Peptide-1 Receptor; Glycated Hemoglobin; Humans; Hypoglycemic Agents; Liraglutide; Receptors, Glucagon | 2014 |
The nonglycemic actions of dipeptidyl peptidase-4 inhibitors.
A cell surface serine protease, dipeptidyl peptidase 4 (DPP-4), cleaves dipeptide from peptides containing proline or alanine in the N-terminal penultimate position. Two important incretin hormones, glucagon-like peptide-1 (GLP-1) and glucose-dependent insulinotropic peptide (GIP), enhance meal-stimulated insulin secretion from pancreatic β-cells, but are inactivated by DPP-4. Diabetes and hyperglycemia increase the DPP-4 protein level and enzymatic activity in blood and tissues. In addition, multiple other functions of DPP-4 suggest that DPP-4 inhibitor, a new class of antidiabetic agents, may have pleiotropic effects. Studies have shown that DPP-4 itself is involved in the inflammatory signaling pathway, the stimulation of vascular smooth cell proliferation, and the stimulation of oxidative stress in various cells. DPP-4 inhibitor ameliorates these pathophysiologic processes and has been shown to have cardiovascular protective effects in both in vitro and in vivo experiments. However, in recent randomized clinical trials, DPP-4 inhibitor therapy in high risk patients with type 2 diabetes did not show cardiovascular protective effects. Some concerns on the actions of DPP-4 inhibitor include sympathetic activation and neuropeptide Y-mediated vascular responses. Further studies are required to fully characterize the cardiovascular effects of DPP-4 inhibitor. Topics: Blood Glucose; Diabetes Mellitus, Type 2; Dipeptidyl Peptidase 4; Dipeptidyl-Peptidase IV Inhibitors; Gastric Inhibitory Polypeptide; Glucagon-Like Peptide 1; Humans; Hypoglycemic Agents; Insulin; Insulin-Secreting Cells; Muscle, Smooth, Vascular; Signal Transduction | 2014 |
[Cardioprotective effects of glucagon-like peptide 1 receptor agonists].
In this paper we discuss pathogenetic mechanisms of cardiovascular risk reduction in patients with type 2 diabetes mellitus by glucagon-like peptide 1 (GLP-1) receptor agonists. Results of experimental studies and randomized clinical studies are presented, and perspectives for using GLP-1 agonists in patients with diabetic cardiovascular complications are described. Topics: Cardiotonic Agents; Cardiovascular Diseases; Diabetes Mellitus, Type 2; Glucagon-Like Peptide 1; Humans; Hypoglycemic Agents; Randomized Controlled Trials as Topic | 2014 |
Therapies for inter-relating diabetes and obesity - GLP-1 and obesity.
The dramatic rise in the prevalence of obesity and type 2 diabetes mellitus (T2DM) is associated with increased mortality, morbidity as well as public health care expenses worldwide. The need for effective and long-lasting pharmaceutical treatment is obvious. The record of anti-obesity drugs has been poor so far and the only efficient treatment today is bariatric surgery. Research has indicated that appetite inhibiting hormones from the gut may have a therapeutic potential in obesity. The gut incretin hormone, glucagon-like peptide-1 (GLP-1), appears to be involved in both peripheral and central pathways mediating satiety. Clinical trials have shown that two GLP-1 receptor agonists exenatide and liraglutide have a weight-lowering potential in non-diabetic obese individuals. Furthermore, they may also hold a potential in preventing diabetes as compared to other weight loss agents.. The purpose of this review is to cover the background for the GLP-1-based therapies and their potential in obesity and pre-diabetes. Up-to-date literature on incretin-based therapies will be summarized with a special mention of their weight-lowering properties. The literature updated to August 2014 from PubMed was identified using the combinations: GLP-1, GLP-1 receptor agonists, incretins, obesity and pre-diabetes.. The incretin impairment, which seems to exist in both obesity and diabetes, may link these two pathologies and underlines the potential of GLP-1-based therapies in the prevention and treatment of these diseases. Topics: Anti-Obesity Agents; Appetite; Diabetes Mellitus, Type 2; Exenatide; Glucagon-Like Peptide 1; Glucagon-Like Peptide-1 Receptor; Humans; Hypoglycemic Agents; Incretins; Liraglutide; Obesity; Peptides; Prediabetic State; Receptors, Glucagon; Venoms | 2014 |
Physiological mechanisms of action of incretin and insulin in regulating skeletal muscle metabolism.
Type II diabetes (T2D) is a progressive condition affecting approximately 350 million adults worldwide. Whilst skeletal muscle insulin resistance and beta-cell dysfunction are recognised causes of T2D, progressive loss of lean muscle mass (reducing surface area for glucose disposal area) in tandem with ageing-related adiposity (i.e. sarcopenic obesity) also plays an important role in driving hyperglycaemia progression. The anabolic effects of nutrition on the muscle are driven by the uptake of amino acids, into skeletal muscle protein, and insulin plays a crucial role in regulating this. Meanwhile glucagon-like peptide (GLP-1) and glucose- dependent insulinotropic peptide (GIP) are incretin hormones released from the gut into the bloodstream in response to macronutrients, and have an established role in enhancing insulin secretion. Intriguingly, endocrine functions of incretins were recently shown to extend beyond classical insulinotropic effects, with GLP-1/GIP receptors being found in extra-pancreatic cells i.e., skeletal muscle and peripheral (muscle) microvasculature. Since, incretins have been shown to modulate blood flow and muscle glucose uptake in an insulin-independent manner, incretins may play a role in regulating nutrient-mediated modulation of muscle metabolism and microvascular tone, independently of their insulinotropic effects. In this review we will discuss the role of skeletal muscle in glucose homeostasis, disturbances related to insulin resistance, regulation of skeletal muscle metabolism, muscle microvascular abnormalities and disturbances of protein (PRO) metabolism seen in old age and T2D. We will also discuss the emerging non-insulinotropic role of GLP-1 in modulating skeletal muscle metabolism and microvascular blood flow. Topics: Blood Flow Velocity; Blood Glucose; Diabetes Mellitus, Type 2; Gastric Inhibitory Polypeptide; Glucagon; Glucagon-Like Peptide 1; Glucose; Homeostasis; Humans; Hyperglycemia; Hypoglycemic Agents; Incretins; Insulin; Insulin Resistance; Microcirculation; Muscle, Skeletal | 2014 |
[The physiology of glucagon-like peptide-1 and its role in the pathophysiology of type 2 diabetes mellitus].
The hormone glucagon-like peptide-1 (GLP-1) is synthesized and secreted by L cells in the small intestine in response to food ingestion. After reaching the general circulation it has a half-life of 2-3 minutes due to degradation by the enzyme dipeptidyl peptidase-4. Its physiological role is directed to control plasma glucose concentration, though GLP-1 also plays other different metabolic functions following nutrient absorption. Biological activities of GLP-1 include stimulation of insulin biosynthesis and glucose-dependent insulin secretion by pancreatic beta cell, inhibition of glucagon secretion, delay of gastric emptying and inhibition of food intake. GLP-1 is able to reduce plasma glucose levels in patients with type 2 diabetes and also can restore beta cell sensitivity to exogenous secretagogues, suggesting that the increasing GLP-1 concentration may be an useful therapeutic strategy for the treatment of patients with type 2 diabetes. Topics: Biomarkers; Blood Glucose; Diabetes Mellitus, Type 2; Gastric Inhibitory Polypeptide; Glucagon-Like Peptide 1; Humans; Hypoglycemic Agents; Incretins; Insulin | 2014 |
[Modulation of the incretin effect in the treatment of diabetes].
Modulation of the incretin effect has opened up a new strategy in the treatment of diabetes mellitus type 2 (DM2). To date, this physiological mechanism has been boosted in two ways: firstly, by pharmacological inhibition of the enzyme that physiologically degrades glucagon-like peptide-1 (GLP-1) receptor agonists, dipeptidyl peptidase-4 (DPP4); secondly, through the development of GLP-1 agonists (GLP-1a) that are resistant to the action of DPP-4. Several clinical trials have shown the clinical superiority of GLPa, which seems to be linked to higher circulating levels of GLP-1. On the other hand, this higher efficacy also seems to be associated with the higher rate of adverse effects associated with aGLP-1 therapy compared with DPP-4 inhibition. These and other differentiating characteristics of the two drug families will determine the choice of drug therapy in the personalized treatment of hyperglycemia in patients with DM2. Topics: Biomarkers; Diabetes Mellitus, Type 2; Dipeptidyl-Peptidase IV Inhibitors; Glucagon-Like Peptide 1; Glucagon-Like Peptide-1 Receptor; Humans; Hypoglycemic Agents; Incretins | 2014 |
Drugs developed for treatment of diabetes show protective effects in Alzheimer's and Parkinson's diseases.
Type 2 diabetes has been identified as a risk factor for Alzheimer's disease (AD) and Parkinson's disease (PD). In the brains of patients with AD and PD, insulin signaling is impaired. This finding has motivated new research that showed good effects using drugs that initially had been developed to treat diabetes. Preclinical studies showed good neuroprotective effects applying insulin or long lasting analogues of incretin peptides. In transgenic animal models of AD or PD, analogues of the incretin GLP-1 prevented neurodegenerative processes and improved neuronal and synaptic functionality and reduced the symptoms of the diseases. Amyloid plaque load and synaptic loss as well as cognitive impairment had been prevented in transgenic AD mouse models, and dopaminergic loss of transmission and motor function has been reversed in animal models of PD. On the basis of these promising findings, several clinical trials are being conducted with the first encouraging clinical results already published. In several pilot studies in AD patients, the nasal application of insulin showed encouraging effects on cognition and biomarkers. A pilot study in PD patients testing a GLP-1 receptor agonist that is currently on the market as a treatment for type 2 diabetes (exendin-4, Byetta) also showed encouraging effects. Several other clinical trials are currently ongoing in AD patients, testing another GLP-1 analogue that is on the market (liraglutide, Victoza). Recently, a third GLP-1 receptor agonist has been brought to the market in Europe (Lixisenatide, Lyxumia), which also shows very promising neuroprotective effects. This review will summarise the range of these protective effects that those drugs have demonstrated. GLP-1 analogues show promise in providing novel treatments that may be protective or even regenerative in AD and PD, something that no current drug does. Topics: Alzheimer Disease; Animals; Diabetes Mellitus, Type 2; Disease Models, Animal; Exenatide; Glucagon-Like Peptide 1; Glucagon-Like Peptide-1 Receptor; Humans; Liraglutide; Mice; Mice, Transgenic; Neuroprotective Agents; Parkinson Disease; Peptides; Receptors, Glucagon; Venoms | 2014 |
Cardiovascular effects of glucagon-like peptide 1 (GLP-1) receptor agonists.
Patients with type 2 diabetes have a several-fold increased risk of developing cardiovascular disease when compared with nondiabetic controls. Myocardial infarction and stroke are responsible for 75% of all death in patients with diabetes, who present a 2-4× increased incidence of death from coronary artery disease. Patients with diabetes are considered for cardiovascular disease secondary prevention because their risk level is similar to that reported in patients without diabetes who have already suffered a myocardial infarction. More recently, with a better risk factors control, mainly in intensive LDL cholesterol targets with statins, a significant decrease in acute cardiovascular events was observed in population with diabetes. Together with other major risk factors, type 2 diabetes must be considered as an important cause of cardiovascular disease.Glucagon like peptide-1 receptor agonists represent a novel class of anti-hyperglycemic agents that have a cardiac-friendly profile, preserve neuronal cells and inhibit neuronal degeneration, an anti-inflammatory effect in liver protecting it against steatosis, increase insulin sensitivity, promote weight loss, and increase satiety or anorexia.This review is intended to rationally compile the multifactorial cardiovascular effects of glucagon-like peptide-1 receptor agonists available for the treatment of patients with type 2 diabetes. Topics: Animals; Cardiovascular Diseases; Cardiovascular System; Diabetes Mellitus, Type 2; Glucagon-Like Peptide 1; Glucagon-Like Peptide-1 Receptor; Humans; Hypoglycemic Agents; Receptors, Glucagon | 2014 |
Glucagon and type 2 diabetes: the return of the alpha cell.
In normal physiology, glucagon from pancreatic alpha cells plays an important role in maintaining glucose homeostasis via its regulatory effect on hepatic glucose production. Patients with type 2 diabetes suffer from fasting and postprandial hyperglucagonemia, which stimulate hepatic glucose production and, thus, contribute to the hyperglycemia characterizing these patients. Although this has been known for years, research focusing on alpha cell (patho)physiology has historically been dwarfed by research on beta cells and insulin. Today the mechanisms behind type 2 diabetic hyperglucagonemia are still poorly understood. Preclinical and clinical studies have shown that the gastrointestinal hormone glucose-dependent insulinotropic polypeptide (GIP) might play an important role in this pathophysiological phenomenon. Furthermore, it has become apparent that suppression of glucagon secretion or antagonization of the glucagon receptor constitutes potentially effective treatment strategies for patients with type 2 diabetes. In this review, we focus on the regulation of glucagon secretion by the incretin hormones glucagon-like peptide-1 (GLP-1) and GIP. Furthermore, potential advantages and limitations of suppressing glucagon secretion or antagonizing the glucagon receptor, respectively, in the treatment of patients with type 2 diabetes will be discussed. Topics: Animals; Diabetes Mellitus, Type 2; Gastric Inhibitory Polypeptide; Glucagon; Glucagon-Like Peptide 1; Glucagon-Secreting Cells; Humans | 2014 |
Dulaglutide: first global approval.
Dulaglutide (Trulicity™) is a long-acting, glucagon-like peptide-1 (GLP-1) receptor agonist that has been developed by Eli Lilly and Company for the treatment of type 2 diabetes mellitus. It consists of a dipeptidyl peptidase-IV-protected GLP-1 analogue covalently linked to a human IgG4-Fc heavy chain by a small peptide linker. The subcutaneous formulation is approved for use in type 2 diabetes in the US, has been recommended for approval in the EU in this indication, and is under regulatory review in other countries. This article summarizes the milestones in the development of subcutaneous dulaglutide leading to this first approval for type 2 diabetes. Topics: Diabetes Mellitus, Type 2; Drug Approval; Glucagon-Like Peptide 1; Glucagon-Like Peptides; Humans; Hypoglycemic Agents; Immunoglobulin Fc Fragments; Recombinant Fusion Proteins; Structure-Activity Relationship | 2014 |
Liraglutide: a review of its use in adult patients with type 2 diabetes mellitus.
Subcutaneous liraglutide (Victoza(®)), a glucagon-like peptide 1 receptor agonist, is approved for the treatment of adult patients with type 2 diabetes mellitus. Once-daily liraglutide, as monotherapy or add-on therapy to other antidiabetic agents (including basal insulin), was an effective and generally well tolerated treatment in adult patients with type 2 diabetes in several well-designed phase III trials and in the real world clinical practice setting. In addition to improving glycaemic control, liraglutide had beneficial effects on bodyweight, systolic blood pressure and surrogate measures of β-cell function in clinical trials, with these benefits maintained during long-term treatment (≤2 years). Liraglutide has a convenient once-daily administration regimen, a low potential for drug-drug interactions and low propensity to cause hypoglycaemia. Thus, liraglutide continues to be a useful option for the management of type 2 diabetes. This article reviews the therapeutic use of liraglutide in adult patients with type 2 diabetes and summarizes its pharmacological properties. Topics: Adult; Biological Availability; Blood Pressure; Body Weight; Diabetes Mellitus, Type 2; Glucagon-Like Peptide 1; Glucagon-Like Peptide-1 Receptor; Humans; Hypoglycemia; Hypoglycemic Agents; Liraglutide; Receptors, Glucagon; Treatment Outcome | 2014 |
Albiglutide for the treatment of type 2 diabetes.
The glucagon-like peptide 1 (GLP-1) receptor agonists are a new class of antidiabetic drugs that provide the benefits of decreasing HbA1c and plasma glucose concentrations, stimulating insulin secretion with a very low risk of hypoglycemia, and promoting weight loss. With the exception of once-weekly exenatide, currently available GLP-1 receptor agonists are administered once or twice daily by injection. Albiglutide is a new GLP-1 receptor agonist recently approved in the U.S. (Tanzeum™) and European Union (Eperzan®) for the treatment of patients with type 2 diabetes with a dosage of 30 mg once weekly, which may be increased to 50 mg if the glycemic response is inadequate. Clinical trials showed that albiglutide once weekly delayed gastric emptying, mildly decreased body weight and had similar efficacy in the reduction of HbA1c as comparators, but it failed to demonstrate noninferiority to liraglutide. Albiglutide exhibits an acceptable safety profile, although it is associated with more frequent gastrointestinal complaints (e.g., nausea, diarrhea, vomiting) and injection-site reactions. Immunogenicity (i.e., testing positive for anti-drug antibody) was observed in 5.5% of subjects but it was not associated with increased adverse events. Long-term studies are needed to fully assess potential adverse events. Topics: Clinical Trials as Topic; Diabetes Mellitus, Type 2; Glucagon-Like Peptide 1; Humans; Hypoglycemic Agents | 2014 |
GLP-1 receptor agonists for type 2 diabetes mellitus: recent developments and emerging agents.
More than 26 million people in the United States have type 2 diabetes mellitus (T2D). Many treatment options exist, but achieving long-term glycemic control in patients with T2D remains challenging. The glucagon-like peptide-1 receptor agonists (GLP-1 RAs) offer a treatment option that improves glycemic control and reduces weight, with a low risk of hypoglycemia. They have emerged as attractive options for the treatment of T2D, and significant advances and developments continue to be published regarding these agents. To identify relevant literature on emerging issues related to GLP-1 RAs, a search of the MEDLINE database was performed. Studies published in English evaluating the safety and efficacy of GLP-1 RAs were analyzed. Because of their advantages and unique mechanism of action, GLP-1 RAs are currently being studied in new clinical areas, including in combination with basal insulin, as adjunctive therapy in type 1 diabetes, and for weight loss. In addition, there are several emerging agents in development. Lixisenatide is a once-daily GLP-1 RA that targets postprandial glucose and may be most useful when added to basal insulin as an alternative to rapid-acting insulin. Albiglutide and dulaglutide are once-weekly GLP-1 RAs that may offer more convenient dosing. The most common adverse effects of all GLP-1 RA agents are gastrointestinal (e.g., nausea, diarrhea, and vomiting), but the rates of occurrence vary among agents. Due to the differences in pharmacokinetics, efficacy, rates of adverse effects, and administration requirements within the GLP-1 RA class, each agent should be evaluated independently. The future of GLP-1 RAs offers broader treatment options for T2D as well as potential in other treatment areas. Topics: Anti-Obesity Agents; Diabetes Mellitus, Type 2; Drug Administration Schedule; Drug Therapy, Combination; Drugs, Investigational; Glucagon-Like Peptide 1; Glucagon-Like Peptide-1 Receptor; Glucagon-Like Peptides; Humans; Hyperglycemia; Hypoglycemia; Hypoglycemic Agents; Immunoglobulin Fc Fragments; Injections, Subcutaneous; Insulin; Peptides; Receptors, Glucagon; Recombinant Fusion Proteins; Weight Loss | 2014 |
Liraglutide for the treatment of type 2 diabetes mellitus: a meta-analysis of randomized placebo-controlled trials.
Liraglutide has been widely used in the treatment of type 2 diabetes mellitus (T2DM), however, the results of a number of randomized placebo-controlled trials on the effects of liraglutide for the treatment of T2DM have varied. The purpose of this study was to assess the effects of liraglutide versus placebo for the treatment of T2DM.. We searched randomized controlled trials comparing liraglutide and placebo for the treatment of T2DM in the following databases: MEDLINE; EMBASE; Cochrane Library Central Register of Controlled Trials; and Clinical Trials Gov (through August 2014). The standard mean difference (SMD) was calculated for the continuous data and a χ (2) test was used to evaluate heterogeneity.. Initially, 103 articles were retrieved through the literature search and 11 studies met the requirements for the meta-analysis. The effects of liraglutide on lowering glycosylated hemoglobin, fasting plasma glucose, reducing weight, lowering blood pressure, and the prevalence of adverse events were significantly different from placebo (P < 0.0001, SMD = -0.96, 95% CI = [-1.20, -0.73]; P < 0.0001, SMD = -0.72, 95% CI = [-0.99, -0.45]; P = 0.004, SMD = -0.24, 95% CI = [-0.40, -0.07]; P = 0.021, SMD = -0.15, 95% CI = [-0.27, -0.02], and P = 0.007, respectively).. Liraglutide had greater hypoglycemic, weight-reducing and systolic blood pressure-lowering effects than placebo. However, there were more adverse events in the treatment with liraglutide. It is suggested that additional well-designed, large, studies be conducted to further support the use of liraglutide and provide objective guidance for clinical application of liraglutide. Topics: Blood Pressure; Diabetes Mellitus, Type 2; Glucagon-Like Peptide 1; Glucagon-Like Peptide-2 Receptor; Glycated Hemoglobin; Humans; Hypoglycemic Agents; Liraglutide; Outcome Assessment, Health Care; Randomized Controlled Trials as Topic; Weight Loss | 2014 |
Combining a GLP-1 receptor agonist and basal insulin: study evidence and practical considerations.
Most patients with diabetes mellitus require multiple medications to achieve glycemic goals. Considering this and the increasing incidence of type 2 diabetes worldwide, the need for effective combination therapy is pressing. Basal insulin and glucagon-like peptide 1 (GLP-1) receptor agonists are frequently used to treat type 2 diabetes. Though both classes of medication are exclusively injectable, which may cause initial hesitation from providers, evidence for their combined use is substantial. This review summarizes the theoretical benefit, supporting evidence, and implementation of a combined basal insulin-GLP-1 receptor agonist regimen. Basal insulin added to a GLP-1 receptor agonist reduces hemoglobin A1c (HbA1c) without weight gain or significantly increased hypoglycemia. A GLP-1 receptor agonist added to basal insulin reduces HbA1c and body weight. Compared with the addition of meal-time insulin to basal insulin, a GLP-1 receptor agonist produces similar or greater reduction in HbA1c, weight loss instead of weight gain, and less hypoglycemia. Gastrointestinal adverse events are common with GLP-1 receptor agonists, especially during initiation and titration. However, combination with basal insulin is not expected to augment expected adverse events that come with using a GLP-1 receptor agonist. Basal insulin can be added to a GLP-1 receptor agonist with a slow titration to target goal fasting plasma glucose. In patients starting a GLP-1 receptor agonist, the dose of basal insulin should be decreased by 20 % in patients with an HbA1c ≤8 %. The evidence from 15 randomized prospective studies supports the combined use of a GLP-1 receptor agonist with basal insulin in a broad range of patients with uncontrolled type 2 diabetes. Topics: Blood Glucose; Diabetes Mellitus, Type 2; Drug Therapy, Combination; Glucagon-Like Peptide 1; Glucagon-Like Peptide-1 Receptor; Glycated Hemoglobin; Humans; Hypoglycemic Agents; Injections; Insulin; Randomized Controlled Trials as Topic; Receptors, Glucagon; Treatment Outcome | 2014 |
[Glucagon-like peptide-1 (GLP-1) mimetics: a new treatment for Alzheimer's disease?].
The glucagon-like peptide-1 (GLP-1) mimetics are an established therapeutic option for patients with type 2 diabetes. However, the properties of the GLP-1 mimetics go beyond the strict metabolic control of the patients with diabetes. The neuroprotective effects of GLP-1 have been shown in recent studies opening new areas of research in neurodegenerative diseases such as Alzheimer's disease (AD), among others. AIM. Systematic review including experimental studies and human clinical trials demonstrating the neuroprotective properties of GLP-1 mimetics in AD.. The experimental studies that have been conducted in rodent models of AD have demonstrated the neuroprotective properties of GLP-1 in the central nervous system reducing beta-amyloid plaques, the oxidative stress and the inflammatory brain response. Clinical trials in patients with cognitive impairment and AD testing the effects of GLP-1 analogs have recently started.. The GLP-1 analogs have neuroprotective properties. Considering that type 2 diabetes is a risk factor for cognitive impairment and dementia, the benefits of GLP-1 mimetics on cognition must be considered. Likewise, the GLP-1 mimetics represent a promising treatment for neurodegenerative diseases such as AD.. Analogos del glucagon-like peptide-1 (GLP-1): una nueva estrategia de tratamiento para la enfermedad de Alzheimer?. Introduccion. Los analogos del glucagon-like peptide-1 (GLP-1) son una opcion terapeutica establecida en los pacientes con diabetes tipo 2. Sin embargo, las propiedades de los analogos del GLP-1 van mas alla del control estrictamente metabolico del paciente diabetico. Los efectos neuroprotectores de los analogos del GLP-1 se han puesto de manifiesto en estudios recientes y han abierto nuevos campos de investigacion en trastornos neurodegenerativos como la enfermedad de Alzheimer (EA), entre otros. Objetivo. Revision sistematica de los estudios experimentales y ensayos clinicos en humanos que demuestran las propiedades neuroprotectoras de los analogos del GLP-1 en la EA. Desarrollo. Los estudios experimentales que se han llevado a cabo en modelos de roedores con EA demuestran las propiedades neuroprotectoras de los analogos del GLP-1 sobre el sistema nervioso central que reducen las placas de beta-amiloide, el estres oxidativo y la respuesta inflamatoria cerebral. Recientemente se han puesto en marcha estudios con analogos del GLP-1 en humanos con deterioro cognitivo y EA. Conclusiones. Los analogos del GLP-1 presentan propiedades neuroprotectoras. Al considerarse la diabetes tipo 2 un factor de riesgo para el deterioro cognitivo y la demencia, deben considerarse los beneficios de los analogos del GLP-1 sobre la cognicion. Del mismo modo, los analogos del GLP-1 suponen un tratamiento prometedor en la EA. Topics: Alzheimer Disease; Animals; Blood-Brain Barrier; Brain Chemistry; Clinical Trials as Topic; Diabetes Mellitus, Type 2; Drug Evaluation, Preclinical; Exenatide; Glucagon-Like Peptide 1; Glucagon-Like Peptide-1 Receptor; Humans; Hypoglycemic Agents; Incretins; Insulin Resistance; Liraglutide; Models, Neurological; Neuroprotective Agents; Peptides; Randomized Controlled Trials as Topic; Receptors, Glucagon; Risk Factors; Venoms | 2014 |
[Modern medical treatment of type 2 diabetes].
Topics: Administration, Oral; Diabetes Mellitus, Type 2; Drug Therapy, Combination; Glucagon-Like Peptide 1; Humans; Hypoglycemic Agents; Insulin Detemir; Insulin, Long-Acting; Patient-Centered Care; Practice Guidelines as Topic | 2014 |
[Characteristics and types of GLP-1 receptor agonists. An opportunity for individualized therapy].
Glucagon-like peptide 1 (GLP-1) is secreted from enteroendocrine L-cells in response to oral nutrient intake and elicits glucose-stimulated insulin secretion while suppressing glucagon secretion. Moreover slows gastric emptying -reducing postprandial glycemic excursions-, reduces body weight, systolic blood pressure and has beneficial effects in the cardiovascular and central nervous systems. Since the 1990s, the efficacy of GLP-1 in reducing blood glucose levels in type 2 diabetes (DM2) was well known. However, GLP-1 should be administered by chronic subcutaneous infusion because of the rapid cleavage by the enzyme dipeptidyl peptidase 4 (DPP-4). Hence, DPP-4 inhibitors -which increase pseudo-physiologically endogenous GLP-1 levels- were developed. In addition, several GLP-1 receptor agonists have been designed to avoid DPP-4-breakdown and/or rapid renal elimination and, therefore, induce a pharmacologic effect in the GLP-1 receptor: short-acting, long-acting, and prolonged-acting GLP-1 analogs. Each class has different structural, pharmacodynamic and clinical properties and could be administered in different therapeutical regimens giving us the opportunity to individualize the therapy of DM2. Topics: Amino Acid Sequence; Clinical Trials as Topic; Diabetes Mellitus, Type 2; Dipeptidyl Peptidase 4; Dipeptidyl-Peptidase IV Inhibitors; Forecasting; Gastrointestinal Diseases; Glucagon-Like Peptide 1; Glucagon-Like Peptide-1 Receptor; Half-Life; Humans; Hyperglycemia; Hypoglycemic Agents; Incretins; Infusions, Subcutaneous; Kidney; Molecular Sequence Data; Multicenter Studies as Topic; Precision Medicine; Proteolysis; Receptors, Glucagon | 2014 |
[Effects of GLP-1 receptor agonists on carbohydrate metabolism control].
Glucagon-like peptide-1 (GLP-1) receptor agonists are a new group of drugs for the treatment of type 2 diabetes mellitus (DM2). In the present article, we review the available evidence on the efficacy of GLP-1 receptor agonists as glucose-lowering agents, their place in therapeutic algorithms, and the clinical factors associated with a favorable treatment response. Finally, we describe the clinical characteristics of patients who may benefit from these drugs. Topics: Blood Glucose; Carbohydrate Metabolism; Clinical Trials as Topic; Consensus Development Conferences as Topic; Diabetes Mellitus, Type 2; Drug Substitution; Drug Synergism; Drug Therapy, Combination; Glucagon-Like Peptide 1; Glucagon-Like Peptide-1 Receptor; Glycated Hemoglobin; Humans; Hypoglycemic Agents; Insulin; Metformin; Multicenter Studies as Topic; Patient Selection; Receptors, Glucagon; Spain | 2014 |
[Twice-daily and weekly exenatide: clinical profile of two pioneer formulations in incretin therapy].
GLP-1 receptors agonists have been a substantial change in treatment of type 2 diabetes mellitus, and its weekly administration has broken pre-established schemes. Daily exenatide is administered every 12 hours (BID) subcutaneously, while weekly exenatide is administered once a week. Both molecules share a common mechanism of action but have differential effects on basal and postprandial glucose. We review the major clinical trials with both exenatide BID and weekly exenatide. It can be concluded that exenatide BID shows a hypoglycemic effect similar to other treatments for type 2 DM but adding significant weight loss with low incidence of hypoglycemia. Weekly exenatide decreases HbA1c similar to liraglutide but larger than exenatide BID, both glargine and biphasic insulin, sitagliptin, and pioglitazone, maintaining weight loss and adding to gastrointestinal intolerance the induration at the injection site as a side effect. Topics: Delayed-Action Preparations; Diabetes Mellitus, Type 2; Dipeptidyl-Peptidase IV Inhibitors; Drug Administration Schedule; Exenatide; Female; Gastrointestinal Diseases; Glucagon-Like Peptide 1; Glucagon-Like Peptide-1 Receptor; Glycated Hemoglobin; Humans; Hyperglycemia; Hypoglycemia; Hypoglycemic Agents; Incretins; Injections, Subcutaneous; Insulin; Insulin Glargine; Insulin, Long-Acting; Liraglutide; Male; Metformin; Peptides; Pioglitazone; Receptors, Glucagon; Thiazolidinediones; Venoms; Weight Loss | 2014 |
GLP-1R agonist therapy for diabetes: benefits and potential risks.
Glucagon-like peptide 1 receptor (GLP-1R) agonists provide good glycemic control combined with low hypoglycemia risk and weight loss. Here, we summarize the recently published data for this therapy class, focusing on sustainability of action, use in combination with basal insulin, and the efficacy of longer acting agents currently in development. The safety profile of GLP-1R agonists is also examined.. GLP-1R agonists provide sustained efficacy and their combination with basal insulin is well tolerated, providing additional glycemic control and weight benefits compared with basal insulin alone. Data suggest that the convenience of longer acting agents may be at the expense of efficacy. Despite the initial concerns, most evidence indicates that GLP-1R agonists do not increase the risk of pancreatitis or thyroid cancer. However, the extremely low incidence of these events means further investigations are required before a causal link can be eliminated. Large-scale clinical trials investigating the long-term cardiovascular safety of this therapy class are ongoing and may also provide important insights into pancreatic and thyroid safety.. GLP-1R agonists offer sustained glycemic efficacy, weight loss benefits, and a low risk of hypoglycemia. The results of ongoing trials should help to clarify the safety of this therapy class. Topics: Blood Glucose; Diabetes Mellitus, Type 1; Diabetes Mellitus, Type 2; Diabetic Angiopathies; Exenatide; Female; Glucagon-Like Peptide 1; Glucagon-Like Peptides; Humans; Hypoglycemia; Hypoglycemic Agents; Immunoglobulin Fc Fragments; Insulin; Liraglutide; Male; Pancreatitis; Peptides; Randomized Controlled Trials as Topic; Recombinant Fusion Proteins; Thyroid Neoplasms; Treatment Outcome; Venoms | 2013 |
Is there a place for incretin therapies in obesity and prediabetes?
Incretin-based therapies exploit the insulinotropic actions of the gut hormones gastric inhibitory peptide (GIP) and glucagon-like peptide-1 (GLP-1) for the treatment of diabetes and include GLP-1 receptor agonists and inhibitors of dipeptidyl peptidase-4 (DPP-4), the enzyme that inactivates the incretin hormones in the body. Both drug classes improve metabolic control in type 2 diabetes (T2DM), with GLP-1 receptor agonists also lowering body weight. Pharmacotherapy using DPP-4 inhibitors has few side effects and is weight neutral. Animal studies support their use in prediabetes; however, human data are scarce. GLP-1 receptor agonist effects are also apparent in non-diabetic obese individuals. Therefore, incretin-based therapies, if safe, may be effective in preventing progression of prediabetes; and GLP-1 receptor agonists may have potential for use in the treatment of obesity. Topics: Animals; Diabetes Mellitus, Type 2; Dipeptidyl-Peptidase IV Inhibitors; Gastric Inhibitory Polypeptide; Glucagon-Like Peptide 1; Glucagon-Like Peptide-1 Receptor; Humans; Incretins; Obesity; Prediabetic State; Receptors, Glucagon | 2013 |
Nutrients related to GLP1 secretory responses.
The hormone glucagon-like peptide (GLP-1) is secreted from gut endocrine L cells in response to ingested nutrients. The activities of GLP-1 include stimulating insulin gene expression and biosynthesis, improving β-cell proliferation, exogenesis, and survival. Additionally, it prevents β-cell apoptosis induced by a variety of cytotoxic agents. In extrapancreatic tissues, GLP-1 suppresses hunger, delays gastric emptying, acts as an ileal brake, and increases glucose uptake. The pleiotropic actions of GLP-1, especially its glucose-lowering effect, gave rise to the suggestion that it is a novel approach to insulin resistance treatment. Hormones secreted from the gut including GLP-1, which are involved in the regulation of insulin sensitivity and secretions, have been found to be affected by nutrient intake. In recent years, there has been a growing interest in the effect nutrients may have on GLP-1 secretion; some frequently studied dietary constituents include monounsaturated fatty acids, fructooligosaccharides, and glutamine. This review focuses on the influence that the carbohydrate, fat, and protein components of a meal may have on the GLP-1 postprandial responses. Topics: Animals; Cell Proliferation; Diabetes Mellitus, Type 2; Dietary Fats; Dietary Fiber; Dietary Proteins; Gastric Emptying; Glucagon-Like Peptide 1; Glutamine; Humans; Insulin; Insulin Resistance; Non-Nutritive Sweeteners; Postprandial Period | 2013 |
Blood pressure-lowering effects of GLP-1 receptor agonists exenatide and liraglutide: a meta-analysis of clinical trials.
Aside from lowering blood glucose, glucagon-like peptide-1 receptor agonists (GLP-1 RAs) attract much attention because of their cardioprotective effects. The aim of this study was to assess the blood pressure-lowering effects of the GLP-1 RAs exenatide and liraglutide compared with other common drugs used to treat type 2 diabetes (T2DM) based on randomized controlled trials (RCTs) including data describing complete blood pressure (BP) changes from baseline.. We searched the major databases for published or unpublished RCTs that had been performed in patients with T2DM and compared the effects of exenatide and liraglutide to those of other common drugs used to treat T2DM. The RCTs that included data describing BP changes between the baseline and the end of the study were selected for further analysis.. A total of 16 RCTs that enrolled 3443 patients in the GLP-1 RA treatment group and 2417 subjects in the control group were included in this meta-analysis. The GLP-1 RA exenatide reduced systolic blood pressure (SBP) when compared with both placebo and insulin glargine, with mean differences of -5.24 and -3.46 mmHg, respectively, and with 95% confidence intervals (CI) of -6.88 to -3.59, p < 0.00001 and -3.63 to -3.29, p < 0.00001, respectively. Meanwhile, in the exenatide-treated group, diastolic blood pressure (DBP) was reduced by -5.91 mmHg, with a 95% CI of -7.53 to -4.28, p < 0.00001 compared with the placebo group, and -0.99 mmHg with a 95% CI of -1.12 to -0.87, p < 0.00001 compared with the sitagliptin group. SBP changes in this meta-analysis were assessed in the groups treated with 1.2 or 1.8 mg liraglutide per day. In the 1.2 mg-treated group, liraglutide treatment reduced SBP compared with placebo and glimepiride treatment, with mean differences of -5.60 and -2.38 mmHg, and 95% CIs of -5.84 to -5.36, p < 0.00001 and -4.75 to -0.01, p = 0.05, respectively. In the 1.8-mg-treated group, liraglutide also reduced SBP compared with placebo and glimepiride treatment with mean differences of -4.49 and -2.62 mmHg, and a 95% CI of -4.73 to -4.26, p < 0.00001, and -2.91 to -2.33, p < 0.00001, respectively.. Treatment with the GLP-1 RAs exenatide and liraglutide reduced SBP and DBP by 1 to 5 mmHg compared with some other anti-diabetic drugs including insulin, glimepiride and placebo for patients with T2DM. GLP-1 RAs may offer an alternative therapy for these patients and will help provide extra cardiovascular benefits. Topics: Blood Glucose; Blood Pressure; Cardiovascular Diseases; Diabetes Mellitus, Type 2; Diabetic Angiopathies; Exenatide; Female; Glucagon-Like Peptide 1; Glucagon-Like Peptide-1 Receptor; Humans; Hypertension; Hypoglycemic Agents; Insulin; Liraglutide; Male; Peptides; Randomized Controlled Trials as Topic; Receptors, Glucagon; Sulfonylurea Compounds; Treatment Outcome; Venoms | 2013 |
Type 2 diabetes and the evolving paradigm in glucose regulation.
Type 2 diabetes mellitus (T2DM) is a multisystem disease comprising numerous metabolic defects that contribute to the development of hyperglycemia. Although insulin resistance in the skeletal muscle and liver together with progressive beta cell failure are traditionally thought of as the core defects responsible for the development and progression of hyperglycemia, research over the past 2 decades has revealed a far more complex interaction of organs and tissues, with consequences for the fundamental understanding of the mechanisms of glucose disequilibrium and the nature of T2DM itself. Dysfunctions in the gastrointestinal tract, adipose tissue, pancreatic alpha cells, brain, and kidneys have all been described, and together with insights into the involvement of liver, muscle, and beta cells produce a more robust picture of T2DM. The function of the kidneys in abnormal glucose homeostasis is a striking example of this evolution in T2DM knowledge, as the role of glucose transporters in regulating plasma glucose levels and producing hyperglycemia has enhanced current understanding of T2DM. As pathophysiologic mechanisms and defects continue to be discovered, they offer an expansion of potential targets for treatment of T2DM. Topics: Adipocytes; Appetite; Brain; Diabetes Mellitus, Type 2; Fasting; Fatty Acids, Nonesterified; Gastric Inhibitory Polypeptide; Gastrointestinal Hormones; Glucagon; Glucagon-Like Peptide 1; Glucagon-Secreting Cells; Glucose; Humans; Insulin Resistance; Insulin-Secreting Cells; Kidney; Liver; Muscle, Skeletal; Obesity; Sodium-Glucose Transport Proteins | 2013 |
[Psoriasis is associated with type 2 diabetes].
Psoriasis is a chronic inflammatory skin disease with a global prevalence of 2-3%. In recent years it has been established that patients with psoriasis carry an increased risk of type 2 diabetes, but the underlying pathophysiological mechanisms remain unclear. The association is most likely due to a combination of shared genes, immunoinflammatory mechanisms and a number of diabetes risk factors in patients with psoriasis. The current review summarises the evidence in the field and calls for attention on diabetes risk assessment, preventive measures and treatment in patients with psoriasis. Topics: Alcohol Drinking; Diabetes Mellitus, Type 2; Glucagon-Like Peptide 1; Glucocorticoids; Humans; Incretins; Metabolic Syndrome; Obesity; Psoriasis; Risk Factors; Smoking | 2013 |
Emerging combinatorial hormone therapies for the treatment of obesity and T2DM.
Peptide hormones and proteins control body weight and glucose homeostasis by engaging peripheral and central metabolic signalling pathways responsible for the maintenance of body weight and euglycaemia. The development of obesity, often in association with type 2 diabetes mellitus (T2DM), reflects a dysregulation of metabolic, anorectic and orexigenic pathways in multiple organs. Notably, therapeutic attempts to normalize body weight and glycaemia with single agents alone have generally been disappointing. The success of bariatric surgery, together with emerging data from preclinical studies, illustrates the rationale and feasibility of using two or more agonists, or single co-agonists, for the treatment of obesity and T2DM. Here, we review advances in the science of co-agonist therapy, and highlight promising areas and challenges in co-agonist development. We describe mechanisms of action for combinations of glucagon-like peptide 1, glucagon, gastric inhibitory polypeptide, gastrin, islet amyloid polypeptide and leptin, which enhance weight loss whilst preserving glucoregulatory efficacy in experimental models of obesity and T2DM. Although substantial progress has been achieved in preclinical studies, the putative success and safety of co-agonist therapy for the treatment of patients with obesity and T2DM remains uncertain and requires extensive additional clinical validation. Topics: Animals; Blood Glucose; Body Weight; Central Nervous System; Diabetes Mellitus, Type 2; Gastric Inhibitory Polypeptide; Glucagon; Glucagon-Like Peptide 1; Humans; Leptin; Obesity | 2013 |
The place of GLP-1-based therapy in diabetes management: differences between DPP-4 inhibitors and GLP-1 receptor agonists.
Type 2 diabetes is a progressive disease characterized by the need for additional antidiabetic agents overtime to maintain a stable level of glycemic control. The discovery of the glucagon like peptide 1, 1 of the 2 major incretins, was pivotal to the development of novel therapies, which can be used in individuals with type 2 diabetes. Two classes of drugs, GLP-1 receptor agonists and dipeptidyl peptidase inhibitors, provide comparable or superior glycemic effects to previous antidiabetic agents without increasing side effects, such as weight gain and hypoglycemia. Therefore, they represent valuable additions to the current therapeutic options for type 2 diabetes. Topics: Animals; Diabetes Mellitus, Type 2; Dipeptidyl-Peptidase IV Inhibitors; Glucagon-Like Peptide 1; Glucagon-Like Peptide-1 Receptor; Humans; Hypoglycemic Agents; Receptors, Glucagon | 2013 |
Thyroid safety in patients treated with liraglutide.
During the last years, various novel anti-diabetic drugs have considerably enriched the therapeutic armamentarium for subjects with Type 2 diabetes. In the meantime, much interest has recently been focused on the potential cardiovascular and oncological adverse effects of these new therapies. As to glucagon-like peptide 1 (GLP-1) analogs, medullary thyroid tumors were reported to be more common in rodent toxicology studies with liraglutide, although the relevance of this finding in humans has been questioned. Analyses of sequential changes in calcitonin levels in several thousands of subjects did not reveal a relationship between liraglutide therapy and plasma calcitonin. Furthermore, no medullary thyroid cancer has been detected in humans taking liraglutide. Nevertheless, the long-term consequences of sustained GLP-1 receptor activation in the human thyroid remain unknown and deserve further investigation. Topics: Diabetes Mellitus, Type 2; Glucagon-Like Peptide 1; Humans; Hypoglycemic Agents; Liraglutide; Randomized Controlled Trials as Topic; Thyroid Gland; Thyroid Neoplasms; Treatment Outcome | 2013 |
Gastrointestinal hormones and bariatric surgery-induced weight loss.
Obesity continues to be a major public health problem in the United States and worldwide. While recent statistics have demonstrated that obesity rates have begun to plateau, more severe classes of obesity are accelerating at a faster pace with important implications in regards to treatment. Bariatric surgery has a profound and durable effect on weight loss, being to date one of the most successful interventions for obesity.. To provide updates to the possible role of gut hormones in post bariatric surgery weight loss and weight loss maintenance.. The current review examines the changes in gastro-intestinal hormones with bariatric surgery and the potential mechanisms by which these changes could result in decreased weight and adiposity.. The mechanism by which bariatric surgery results in body weight changes is incompletely elucidated, but it clearly goes beyond caloric restriction and malabsorption.. Changes in gastro-intestinal hormones, including increases in GLP-1, PYY, and oxyntomodulin, decreases in GIP and ghrelin, or the combined action of all these hormones might play a role in induction and long-term maintenance of weight loss. Topics: Bariatric Surgery; Bile Acids and Salts; Caloric Restriction; Diabetes Mellitus, Type 2; Gastrointestinal Hormones; Ghrelin; Glucagon-Like Peptide 1; Humans; Obesity; Oxyntomodulin; Peptide YY; Postoperative Period; United States; Weight Loss | 2013 |
New incretin hormonal therapies in humans relevant to diabetic cats.
Incretins (gastric inhibitory polypeptide and glucagon-like peptide 1 [GLP-1]) are hormones released from the gastrointestinal tract during food intake that potentiate insulin secretion. Native GLP-1 is quickly degraded by the enzyme dipeptidylpeptidase-4 (DPP-4), which has led to the development of GLP-1 agonists with resistance to degradation and to inhibitors of DPP-4 activity as therapeutic agents in humans with type 2 diabetes. In healthy cats, GLP-1 agonists and DPP-4 inhibitors have produced a substantial increase in insulin secretion. Although results of clinical studies are not yet available, incretin-based therapy promises to become an important new research area in feline diabetes. Topics: Animals; Cat Diseases; Cats; Diabetes Mellitus, Type 2; Dipeptidyl Peptidase 4; Dipeptidyl-Peptidase IV Inhibitors; Enzyme Inhibitors; Gastric Inhibitory Polypeptide; Glucagon-Like Peptide 1; Humans; Incretins; Insulin; Insulin Secretion; Treatment Outcome | 2013 |
Glucagon-like peptides 1 and 2 in health and disease: a review.
The gut derived peptides, glucagon-like peptides 1 and 2 (GLP-1 and GLP-2), are secreted following nutrient ingestion. GLP-1 and another gut peptide, glucose-dependent insulinotropic polypeptide (GIP) are collectively referred to as 'incretin' hormones, and play an important role in glucose homeostasis. Incretin secretion shares a complex interdependent relationship with both postprandial glycemia and the rate of gastric emptying. GLP-1 based therapies are now well established in the management of type 2 diabetes, while recent literature has suggested potential applications to treat obesity and protect against cardiovascular and neurological disease. The mechanism of action of GLP-2 is not well understood, but it shows promise as an intestinotropic agent. Topics: Animals; Blood Glucose; Clinical Trials as Topic; Diabetes Mellitus, Type 2; Gastric Emptying; Glucagon-Like Peptide 1; Glucagon-Like Peptide 2; Humans; Incretins; Pancreas; Postprandial Period; Receptors, Glucagon | 2013 |
The future of insulin therapy for patients with type 2 diabetes mellitus.
Insulin therapy has been the mainstay of therapy for patients with type 2 diabetes mellitus for the past 90 years. This trend is likely to continue as new formulations are developed to more closely mimic physiologic insulin secretion and to provide patients who have diabetes with more convenient options for integrating this therapy into their lifestyle. The present article reviews how the role of insulin continues to evolve, from its earlier use in the treatment paradigm (even at first diagnosis) to its role in combination therapy with incretin-based therapies, as well as new formulations that provide more-convenient forms of insulin replacement therapy. Topics: Blood Glucose; Delayed-Action Preparations; Diabetes Mellitus, Type 2; Drug Therapy, Combination; Glucagon-Like Peptide 1; Glycated Hemoglobin; Humans; Hypoglycemic Agents; Incretins; Insulin | 2013 |
Evaluating second-line treatment options for type 2 diabetes: focus on secondary effects of GLP-1 agonists and DPP-4 inhibitors.
To discuss the controversy surrounding selection of second-line type 2 diabetes mellitus (T2DM) therapy by reviewing available data regarding secondary effects of glucagon-like peptide-1 receptor (GLP-1) agonists and dipeptidyl peptidase-4 (DPP-4) inhibitors, which include low hypoglycemia risk, weight loss, and cardiovascular (CV) and β-cell function benefits.. A MEDLINE search (1966-March 2013) was conducted using the following key terms: β-cell protection, blood pressure, DPP-4 inhibitors, exena tide, exenatide extended-release, GLP-1 agonists, hypoglycemia, lina glip tin, lipid, liraglutide, pancreatitis, saxagliptin, sitagliptin, and type 2 diabetes.. Identified articles published in English were evaluated for inclusion, with priority given to randomized controlled trials in humans receiving incretin monotherapy or incretin combination therapy with metformin. References identified in these articles were reviewed for additional trials.. Most patients with T2DM use combination therapy; however, determination of the second-line agent that is most appropriate is debatable. Prior to the use of incretin therapies, traditional second-line agents included sulfonylureas, thiazolidinediones, and basal insulin, all of which demonstrate undesirable adverse effects. In addition to improving glycemic control, incretin therapies have demonstrated benefits concerning hypoglycemic risk and weight loss in addition to potential improvements in CV risk factors and β-cell function. While there are risks associated with using incretins, most patients with T2DM are good candidates for incretins and could benefit from their potential secondary effects. Cost remains a barrier to initiating these agents.. Demonstrated secondary benefits in addition to efficacy may make GLP-1 agonists and DPP-4 inhibitors a more favorable option than other second-line T2DM therapies. Topics: Blood Glucose; Diabetes Mellitus, Type 2; Dipeptidyl Peptidase 4; Dipeptidyl-Peptidase IV Inhibitors; Glucagon-Like Peptide 1; Humans; Hypoglycemic Agents; Incretins; Insulin-Secreting Cells; Metformin; Randomized Controlled Trials as Topic | 2013 |
Once-weekly exenatide: an extended-duration glucagon-like peptide agonist for the treatment of type 2 diabetes mellitus.
Type 2 diabetes affects over 25 million people in the United States. There are many treatment options for patients with type 2 diabetes, but current treatments must be administered on a daily basis. Once-weekly exenatide, an extended-duration glucagon-like peptide-1 (GLP-1) agonist, provides an option for patients to take a drug weekly, with pharmacotherapeutic effects that are superior to twice-daily exenatide and sitagliptin and comparable to insulin glargine. The DURATION trials provide evidence that once-weekly exenatide reduces hemoglobin A1c , and may result in weight loss. Once-weekly exenatide is marketed as a 2-mg injection administered subcutaneously once every 7 days. Adverse effects of once-weekly exenatide include gastrointestinal effects, hypoglycemia, injection-site reactions, pancreatitis, and antibody development. Patients with a self history or family history of thyroid tumors should avoid using once-weekly exenatide. Delayed gastric absorption with orally administered drugs is possible, and monitoring should occur to avoid loss in therapeutic effect. Once-weekly exenatide is a new extended-duration agent with efficacy and tolerability profiles comparative to older therapies. Appropriate patients for once-weekly exenatide would be those who are concerned about weight gain, hypoglycemia, or those who do not wish to administer injections daily. Topics: Animals; Delayed-Action Preparations; Diabetes Mellitus, Type 2; Drug Administration Schedule; Exenatide; Glucagon-Like Peptide 1; Humans; Hypoglycemic Agents; Injections, Subcutaneous; Peptides; Venoms | 2013 |
Glucagon-like peptide-1 agonists in the treatment of type 2 diabetes.
Topics: Diabetes Mellitus, Type 2; Glucagon-Like Peptide 1; Humans; Hypoglycemic Agents; Incretins | 2013 |
[Significance of combination therapy with an insulin sensitizer and a DPP-4(dipeptidyl peptidase-4) inhibitor].
Type 2 diabetes mellitus is characterized by insulin resistance in peripheral tissues and relative impairment in insulin secretion from pancreatic beta cell. Insulin sensitizers such as metformin and pioglitazone reduce peripheral insulin resistance, whereas dipeptidyl peptidase-4(DPP-4) inhibitors augment postprandial insulin secretion and inhibit glucagon secretion. Combination therapy with an insulin sensitizer and a DPP-4 inhibitor provides substantial and additive glycemic improvement because of the complementary mechanisms of action of these agents. In addition, combination therapy with these agents is an attractive from the perspective of low incidence of hypoglycemia, beta cell preservation, augmentation of the incretin effect, and anti-atherogenic action. Topics: Blood Glucose; Diabetes Mellitus, Type 2; Dipeptidyl-Peptidase IV Inhibitors; Drug Therapy, Combination; Glucagon-Like Peptide 1; Humans; Hypoglycemic Agents; Insulin | 2013 |
[Research progress of mechanisms through which dipeptidyl peptidase-4 inhibitors regulate glycemia].
Dipeptidyl peptidase-4 (DPP-4) inhibitors are promising new antidiabetic drugs. It had been proposed that DPP-4 inhibitors exert their antidiabetic effect by inhibiting the degradation of glucagon-like peptide 1(GLP-1) . However, new evidence has shown that the increase of GLP-1 is not notable after the use of these drugs in patients with type 2 diabetes. Therefore, the specific mechanisms via which DPP-4 inhibitors in controlling blood glucose has became questionable. In recent years, studies have revealed many possible mechanisms through which DPP-4 inhibitors regulate glycemia: DPP-4 inhibitors may selectively reduce DPP-4 activity in the intestine, causing the increase of portal plasma GLP-1 level and thus promoting the release of insulin via nerve reflex;also, they may decrease the cleavage product of GLP-1 and reduce the degradation of other bioactive peptides. Topics: Blood Glucose; Diabetes Mellitus, Type 2; Dipeptidyl-Peptidase IV Inhibitors; Glucagon-Like Peptide 1; Humans; Hypoglycemic Agents | 2013 |
Incretin dysfunction in type 2 diabetes: clinical impact and future perspectives.
The incretin effect refers to the augmentation of insulin secretion after oral administration of glucose compared with intravenous glucose administration at matched glucose levels. The incretin effect is largely due to the release and action on beta-cells of the gut hormones glucose-dependent insulinotropic polypeptide (GIP) and glucagon-like peptide-1 (GLP-1). This system has in recent years had considerable interest due to the success of incretin therapy as a glucose-lowering strategy in type 2 diabetes. In non-diabetic subjects, the incretin effect is responsible for 50-70% of insulin release during oral glucose administration. In type 2 diabetes patients, the incretin effect is impaired and contributes to only 20-35% of the insulin response to oral glucose. The reason for the defective incretin effect in type 2 diabetes has been the subject of many studies. Although the reports in the literature are mixed, most studies of GIP and GLP-1 secretory responses to oral glucose or a mixed meal have shown fairly normal results in type 2 diabetes. In contrast, the insulinotropic effects of both GIP and GLP-1 are impaired in type 2 diabetes with greater suppression of insulin secretion augmentation with GIP than with GLP-1. The suggested causes of these defects are a defective beta-cell receptor expression or post-receptor defects secondary to the diabetes milieu, defective beta-cell function in general resulting in defective incretin effect and genetic factors initiating incretin hormone resistance. Identifying the mechanisms in greater detail would be important for understanding the strengths, weaknesses and efficacy of incretin therapy in individual patients to more specifically target this glucose-lowering therapy. Topics: Diabetes Mellitus, Type 2; Gastric Inhibitory Polypeptide; Glucagon-Like Peptide 1; Humans; Incretins; Insulin; Insulin Secretion | 2013 |
GLP-1 agonists in type 1 diabetes.
Despite years of research in the field of type 1 diabetes, patients with the disease remain without a therapeutic agent that can alter the underlying immune response in a clinically beneficial way. Glucagon-like peptide 1 agonist therapies have shown some promising effects in terms of positively affecting overall beta cell health and increasing beta cell mass, primarily in mouse models. The three agents of this class currently available for patients with type 2 diabetes have shown beneficial clinical effects on glucose control in this patient population. The purpose of this article is to review the preclinical and clinical data of these agents to date with a focus on the potential immunological and clinical benefits these drugs may have on patients with type 1 diabetes. Topics: Animals; Biomarkers; Blood Glucose; C-Peptide; Clinical Trials as Topic; Diabetes Mellitus, Type 1; Diabetes Mellitus, Type 2; Exenatide; Glucagon-Like Peptide 1; Glycated Hemoglobin; Humans; Hypoglycemic Agents; Insulin-Secreting Cells; Liraglutide; Peptides; Venoms | 2013 |
[Management of type 2 diabetes: new or previous agents, how to choose?].
Once lifestyle measures implemented, if hyperglycemia persists, above individual HbA1c targets, a medication should be started in type 2 diabetic patients (T2DM). First, unless exception, an oral antidiabetic drug. Except in case of intolerance, the initial monotherapy, metformin remains the strengthening treatment. Latter, combination of two oral drugs, now offers several options, mainly the choice to associate a "conventional insulin-secretor", sulfonylureas, glinide, or a "new one" belonging the class of "incretin", more readily a gliptine (DPP-4 inhibitors) rather than injectable GLP-1 analogue which can also be sometimes chosen at this stage. These options are mostly new and have the advantage a neutral or favourable (for GLP-1) effect on body weight in obese type 2 DM patient and the absence of any hypoglycaemic risk in both classes of incretins. But this risk varies depending on the patient profile, much higher if the target HbA1c is low (6 to 6.5 or 7%), or in the elderly, fragile and/or in case of renal insufficiency. These two different situations with a high risk of hypoglycaemia, define best indications of this new class. If dual oral therapy does not achieve the goals we are faced with three options: triple oral therapy: metformin-sulfonylurea-gliptine or one of two approaches with injections, insulin or GLP-1 analogues. The use of GLP-1 analogues is often delayed today and put wrongly in balance with the transition to insulin, a use already delayed in France and insufficient. The use of incretins is new and needs to be validated by studies of sustainability on glycemic control, prevention of microvascular and macrovascular complications and after years on the market security of use, primarily on the exocrine pancreas. In short, individualization of strategies and HbA1c targets are required, the new molecules can help us in this process. This individualization can easily be done through the handy guide proposed by the experts ADA EASD statement, endorsed by the SFD, abandoning the complex algorithm recently again proposed by HAS and ANSM in 2013. A recommendation that prioritizes the costs of the strategies. An absolutely critical issue, while admitting not to have the tools to measure them in all their dimensions. Finally, we must reconsider every treatment after a maximum of 6 months of use, if the results are deemed inadequate substitute rather than adding drugs. Topics: Administration, Oral; Body Weight; Diabetes Complications; Diabetes Mellitus, Type 2; Dipeptidyl-Peptidase IV Inhibitors; Disease Management; Drug Therapy, Combination; Glucagon-Like Peptide 1; Glycated Hemoglobin; Goals; Humans; Hypoglycemia; Hypoglycemic Agents; Incretins; Insulin; Insulin Secretion; Kidney; Metformin; Obesity; Practice Guidelines as Topic; Risk; Societies, Medical; Sulfonylurea Compounds | 2013 |
Diabetes update: new drugs to manage type 2 diabetes.
Metformin is the first-line treatment for patients with diabetes because it reduces mortality rates. If metformin is contraindicated or is not tolerated, any one of the other available antihyperglycemic drugs may be used as monotherapy. These drugs are equally effective for glucose control, lowering A1c by approximately 1%. Evidence of their benefit for reducing mortality or morbidity, or improving health-related quality of life is lacking. A sulfonylurea, pioglitazone, or exenatide can be added to maximally dosed metformin if additional glycemic control is necessary. Sulfonylureas and pioglitazone often cause weight gain. The combination of metformin plus a sulfonylurea is associated with a greater risk of hypoglycemia and mortality than the combination of metformin and a thiazolidinedione (ie, glitazone). Thiazolidinediones are contraindicated in patients with severe heart failure or liver disease. Newer drug classes target incretin, the hormone that stimulates food-dependent insulin secretion. The incretin mimetic exenatide, a high-cost injectable drug, is similar to metformin for reduction of A1c and body mass index. Incretin-enhancing dipeptidyl-peptidase 4 inhibitors (ie, gliptins) are inferior to metformin for lowering A1c and body mass index; little is known about their effect on all-cause mortality. Fixed combination products might improve ease of use and adherence; they might also reduce cost and risk of adverse effects. Topics: Blood Glucose; Diabetes Mellitus, Type 2; Dipeptidyl-Peptidase IV Inhibitors; Drug Combinations; Drug Therapy, Combination; Glucagon-Like Peptide 1; Glycated Hemoglobin; Humans; Hypoglycemic Agents; Medication Adherence; Sulfonylurea Compounds; Thiazolidinediones | 2013 |
The role of pharmacogenetics in drug disposition and response of oral glucose-lowering drugs.
The primary goal of type 2 diabetes mellitus (T2DM) disease management is improvement of quality of life and prevention of complications. One way to achieve these goals is improving glycemic control by using different types of oral glucose-lowering medications. Currently seven different pharmacological oral glucose-lowering drug classes are available, each with its own mechanism of action and characteristics regarding absorption, distribution, metabolism, and elimination. Unfortunately, the response to the different types of glucose-lowering medication is highly variable between individuals resulting in unnecessary treatment failure. Genetic factors are thought to contribute to the variability in response and may present an opportunity to improve treatment outcome. In recent years, many efforts were taken to identify genetic variants that influence the pharmacokinetics, pharmacodynamics, and ultimately the therapeutic response of the different oral glucose-lowering drugs. Indeed several genetic variants are associated with the response to oral glucose-lowering drugs. This review comprises current knowledge on genetic variants affecting both pharmacokinetics and pharmacodynamics of oral glucose-lowering drugs. Included variants are located in genes coding for drug transporters, i.e., the organic anion-transporting family and the organic cation transporter family; genes involved in metabolism, i.e., cytochrome P450 superfamily; genes coding for drug receptors; T2DM-associated genes; and genes identified by genome-wide association studies (GWASs). Furthermore, this review provides insight into current status and future directions for personalized medicine in T2DM. Topics: Diabetes Mellitus, Type 2; Dipeptidyl-Peptidase IV Inhibitors; Genetic Variation; Glucagon-Like Peptide 1; Glycoside Hydrolase Inhibitors; Humans; Hypoglycemic Agents; Thiazolidinediones | 2013 |
Update on the protective molecular pathways improving pancreatic beta-cell dysfunction.
The primary function of pancreatic beta-cells is to produce and release insulin in response to increment in extracellular glucose concentrations, thus maintaining glucose homeostasis. Deficient beta-cell function can have profound metabolic consequences, leading to the development of hyperglycemia and, ultimately, diabetes mellitus. Therefore, strategies targeting the maintenance of the normal function and protecting pancreatic beta-cells from injury or death might be crucial in the treatment of diabetes. This narrative review will update evidence from the recently identified molecular regulators preserving beta-cell mass and function recovery in order to suggest potential therapeutic targets against diabetes. This review will also highlight the relevance for novel molecular pathways potentially improving beta-cell dysfunction. Topics: Calcium; Diabetes Mellitus, Type 2; Glucagon-Like Peptide 1; Humans; Hypoglycemic Agents; Insulin-Secreting Cells; Metformin; MicroRNAs | 2013 |
Recent progress and future options in the development of GLP-1 receptor agonists for the treatment of diabesity.
The dramatic rise of the twin epidemics, type 2 diabetes and obesity is associated with increased mortality and morbidity worldwide. Based on this global development there is clinical need for anti-diabetic therapies with accompanied weight reduction. From the approved therapies, the injectable glucagon-like peptide-1 receptor agonists (GLP-1 RAs) are the only class of agents which are associated with a modest weight reduction. Physiological effects of the gastro-intestinal hormone GLP-1 are improvement of glycemic control as well as a reduction in appetite and food intake. Different approaches are currently under clinical evaluation to optimize the therapeutic potential of GLP-1 RAs directed to once-weekly up to once-monthly administration. The next generation of peptidic co-agonists comprises the activity of GLP-1 plus additional gastro-intestinal hormones with the potential for increased therapeutic benefits compared to GLP-1 RAs. Topics: Clinical Trials as Topic; Diabetes Mellitus, Type 2; Dipeptidyl-Peptidase IV Inhibitors; Glucagon-Like Peptide 1; Glucagon-Like Peptides; Humans; Hypoglycemic Agents; Immunoglobulin Fc Fragments; Liraglutide; Peptides; Recombinant Fusion Proteins | 2013 |
Glucagon-like peptide-1 (GLP-1) and protective effects in cardiovascular disease: a new therapeutic approach for myocardial protection.
Glucagon-like peptide-1 (GLP-1) is a member of the proglucagon incretin family implicated in the control of appetite and satiety. GLP-1 has insulinotropic, insulinomimetic, and glucagonostatic effects, thereby exerting multiple complementary actions to lower blood glucose in subjects with type 2 diabetes mellitus. A major advantage over conventional insulin is the fact that the insulinotropic actions of GLP-1 are dependent upon ambient glucose concentration, mitigating the risks of hypoglycemia. Recently, the crucial role of GLP-1 in cardiovascular disease has been suggested in both preclinical and clinical studies. The experimental data indicate GLP-1 and its analogs to have direct effects on the cardiovascular system, in addition to their classic glucoregulatory actions. Clinically, beneficial effects of GLP-1 have also been demonstrated in patients with myocardial ischemia and heart failure. GLP-1 has recently been demonstrated to be a more effective alternative in treating myocardial injury. This paper provides a review on the current evidence supporting the use of GLP-1 in experimental animal models and human trials with the ischemic and non-ischemic heart and discusses their molecular mechanisms and potential as a new therapeutic approach. Topics: Animals; Anti-Obesity Agents; Antihypertensive Agents; Cardiotonic Agents; Cardiovascular Diseases; Cardiovascular System; Diabetes Mellitus, Type 2; Glucagon-Like Peptide 1; Glucagon-Like Peptide-1 Receptor; Heart; Humans; Receptors, Glucagon | 2013 |
Incretins and amylin in pediatric diabetes: new tools for management of diabetes in youth.
The purpose of this review is to examine recently published literature in the areas of incretins and amylin in the management of pediatric diabetes.. Recent studies have begun to explore the use of longer-acting GLP-1 analogues that can be given once daily, such as liraglutide, and the use of DPP-IV inhibitors in the management of type 2 diabetes. In addition, recent studies have been published on the use of exenatide in the management of pediatric obesity and newly diagnosed type 1 diabetes.. Very few medications are approved for management of type 2 diabetes in youth. In addition, monotherapy of type 1 diabetes in youth with insulin does not achieve HbA1c targets in the majority of youth despite the use of rapid-acting insulin analogues, insulin pump therapy, and continuous glucose monitoring. Novel therapies that target physiologic modalities other than enhancing or replacing insulin secretion or improving insulin sensitivity have shown efficacy in adults. Studies with these drugs are being done in the pediatric population and should provide additional treatment options for these patients. Topics: Adolescent; Child; Diabetes Mellitus, Type 1; Diabetes Mellitus, Type 2; Disease Management; Glucagon-Like Peptide 1; Humans; Hypoglycemic Agents; Incretins; Islet Amyloid Polypeptide; Pediatric Obesity | 2013 |
The role of DPP4 activity in cardiovascular districts: in vivo and in vitro evidence.
The introduction of incretin hormone-based therapies represents a novel therapeutic strategy, since these drugs not only improve glycemia with minimal risk of hypoglycemia, but also have other extraglycemic beneficial effects. These agents, which are effective in improving glucose control, could also have positive effects on the incidence of cardiovascular events. The aim of this review is to summarize the present literature about the role of dipeptidyl peptidase 4 (DPP4) in cardiovascular districts, not only strictly correlated to its effect on glucagon-like peptide-1 (GLP-1) circulating levels, but also to what is known about possible cardiovascular actions. Actually, DPP4 is known to be present in many cells and tissues and its effects go beyond purely metabolic aspects. Almost always the inhibition of DPP4 activity is associated with improved cardiovascular profile, but it has shown to possess antithrombotic properties and these different effects could be connected with a site and/or species specificity of DPP4. Certainly, DPP4 seems to exert many functions, both directly and indirectly, on cardiovascular districts, opening new possibilities of prevention and treatment of complications at this level, not only in patients affected by diabetes mellitus. Topics: Animals; Cardiovascular System; Diabetes Mellitus, Type 2; Dipeptidyl Peptidase 4; Dipeptidyl-Peptidase IV Inhibitors; Glucagon-Like Peptide 1; Humans; Hypoglycemic Agents | 2013 |
Incretin-based therapies for type 2 diabetes mellitus: effects on insulin resistance.
Insulin resistance has been associated with the development of type 2 diabetes, obesity, hypertension, dyslipidemia, atherosclerosis, and thus with increased cardiovascular morbidity and mortality. Insulin resistance precedes the onset of type 2 diabetes by many years. Targeting the pathophysiologic defects that characterize the onset of diabetes is more likely to achieve a durable glucose control and to delay disease progression. Incretins are gut-derived peptides that stimulate in a glucose-dependent mechanism insulin secretion and action. Glucose-like peptide 1 (GLP-1) analogues and dipeptidyl peptidase-4 (DPP-4) inhibitors both decrease fasting and postprandial glucose levels. In addition, GLP-1 analogues promote weight loss and exert a favorable effect on several cardiovascular risk factors. Data from human and experimental studies implicate that GLP-1 analogues and to a less extend DPP-4 inhibitors enhance insulin sensitivity. This review summarizes the current knowledge regarding the impact of GLP-1 analogues and DPP-4 inhibitors on insulin resistance. Topics: Animals; Diabetes Mellitus, Type 2; Dipeptidyl-Peptidase IV Inhibitors; Glucagon-Like Peptide 1; Humans; Incretins; Insulin Resistance | 2013 |
Physiology of incretins and loss of incretin effect in type 2 diabetes and obesity.
An important role in the regulation of glucose homeostasis is played by incretins, which are gut-derived hormones released in response to nutrient ingestion. In humans, the major incretin hormones are glucagon-like peptide (GLP)-1 and glucose-dependent insulinotropic polypeptide (GIP), and together they fully account for the incretin effect (that is, higher insulin release in response to an oral glucose challenge compared to an equal intravenous glucose load). Studies have shown that GLP-1 and GIP levels and actions may be perturbed in disease states, and the loss of incretin effect is likely to contribute importantly to the postprandial hyperglycaemia in type 2 diabetes. However, the specific cause-effect relationship between disease and incretins is still unclear. This review focuses on several key studies elucidating the association of defective incretin action with obesity and T2DM and the effects of metformin and other anti-diabetic agents on the incretin system. Topics: Animals; Diabetes Mellitus, Type 2; Gastric Inhibitory Polypeptide; Glucagon-Like Peptide 1; Humans; Incretins; Obesity | 2013 |
Minireview: Signal bias, allosterism, and polymorphic variation at the GLP-1R: implications for drug discovery.
The glucagon-like peptide-1 receptor (GLP-1R) controls the physiological responses to the incretin hormone glucagon-like peptide-1 and is a major therapeutic target for the treatment of type 2 diabetes, owing to the broad range of effects that are mediated upon its activation. These include the promotion of glucose-dependent insulin secretion, increased insulin biosynthesis, preservation of β-cell mass, improved peripheral insulin action, and promotion of weight loss. Regulation of GLP-1R function is complex, with multiple endogenous and exogenous peptides that interact with the receptor that result in the activation of numerous downstream signaling cascades. The current understanding of GLP-1R signaling and regulation is limited, with the desired spectrum of signaling required for the ideal therapeutic outcome still to be determined. In addition, there are several single-nucleotide polymorphisms (used in this review as defining a natural change of single nucleotide in the receptor sequence; clinically, this is viewed as a single-nucleotide polymorphism only if the frequency of the mutation occurs in 1% or more of the population) distributed within the coding sequence of the receptor protein that have the potential to produce differential responses for distinct ligands. In this review, we discuss the current understanding of GLP-1R function, in particular highlighting recent advances in the field on ligand-directed signal bias, allosteric modulation, and probe dependence and the implications of these behaviors for drug discovery and development. Topics: Allosteric Regulation; Amino Acid Sequence; Diabetes Mellitus, Type 2; Drug Discovery; Glucagon-Like Peptide 1; Glucagon-Like Peptide-1 Receptor; Glucose; Humans; Incretins; Insulin; Insulin Secretion; Molecular Sequence Data; Polymorphism, Single Nucleotide; Receptors, Glucagon; Signal Transduction | 2013 |
GLP-1 receptor agonists: effects on cardiovascular risk reduction.
Comorbid obesity, dyslipidemia, and hypertension place patients with type 2 diabetes (T2DM) at greatly increased risk of cardiovascular (CV) disease-related morbidity and mortality. An urgent need exists for effective treatment for patients with T2DM that encompasses glycemic control, weight loss, and reduction in CV risk factors. The glucagon-like peptide-1 receptor agonists (GLP-1 RAs) liraglutide and exenatide are incretin-based antidiabetes agents. This review examines CV-associated effects of liraglutide and exenatide in animal models and clinical trials with patients with T2DM. Studies support the effectiveness of GLP-1 RAs in reducing hyperglycemia. Further, GLP-1 RAs represent a significant advance in T2DM treatment because they uniquely affect a broad array of CV risk factors through significant weight and systolic blood pressure reduction, improved lipid levels, and possibly, as shown in in vitro studies and animal models, through direct effects on cardiac myocytes and endothelium. Topics: Animals; Cardiovascular Diseases; Diabetes Mellitus, Type 2; Exenatide; Glucagon-Like Peptide 1; Glucagon-Like Peptide-1 Receptor; Humans; Hypoglycemic Agents; Incretins; Liraglutide; Peptides; Receptors, Glucagon; Risk Factors; Treatment Outcome; Venoms | 2013 |
Mono-ADP-ribosyltransferase as a potential pharmacological drug target in the GLP-1 based therapy of obesity and diabetes mellitus type 2.
Glucagon-like peptide-1 (GLP-1) based therapy is well established for treating diabetes mellitus type 2. Moreover, GLP-1 receptor agonists influence weight loss, and have potential for treating obesity. GLP-1 receptor agonists should be administered in low doses, together with drugs that potentiate insulin release, to avoid some minor side effects. We have focused on incretin hormones, especially GLP-1 and its analogues. Here we discuss the effect of the third intracellular loop-derived peptide of GLP-1 receptor on intracellular mono-ADP-ribosyltransferase and its role in regulating the receptor. We suggest that this intracellular mono-ADP-ribosyltransferase could constitute a possible novel pharmacological target in the treatment of diabetes mellitus type 2 and obesity. Topics: ADP Ribose Transferases; Amino Acid Sequence; Diabetes Mellitus, Type 2; Glucagon-Like Peptide 1; Molecular Sequence Data; Obesity | 2013 |
[GLP-1 agonists: an overview].
GLP-1 agonists have been widely used in the therapy of type 2 diabetes due to their beneficial effects regarding weight loss and low risk of hypoglycemia. However, some safety concerns have been raised in view of possible detrimental effects to the pancreas. The future place of GLP-1 agonist in diabetes therapy will be determined by the current safety evaluation and data from studies investigating long-term effects. Topics: Blood Pressure; Diabetes Mellitus, Type 2; Exenatide; Glucagon-Like Peptide 1; Humans; Hypoglycemia; Hypoglycemic Agents; Pancreatic Diseases; Peptides; Venoms | 2013 |
Options for combination therapy in type 2 diabetes: comparison of the ADA/EASD position statement and AACE/ACE algorithm.
Treating patients with diabetes is one of the most challenging and important activities a physician (primary care physician or specialist) can undertake. A key to successful therapy for type 2 diabetes is the insight that this condition is progressive and that the need for additional agents over time is normative. The ability to individualize therapy by patient and medication characteristics comes from experience and knowledge of pertinent clinical studies. However, guidelines from expert bodies such as the American Diabetes Association/European Association for the Study of Diabetes and American Association of Clinical Endocrinologists/American College of Endocrinology can help clinicians of all levels of expertise to approach therapy choices more rationally. There is unity across these guidelines about the role and benefits of metformin as first-line pharmacological treatment, probability of good efficacy, low risk of hypoglycemia, modest weight loss, and overall long-term data. Unfortunately, this unity does not extend to recommendations for subsequent pharmacological agents and their use in combination to intensify treatment when insulin is not (yet) appropriate. Across both statements, some drug classes seem more prominent, and looking at their benefit-risk profile, it is clear why this is the case. The most profound recent change in diabetes therapy has been the introduction of incretin therapies. Incretin therapies minimize 2 important adverse effects seen with many other therapies: hypoglycemia and weight gain. These agents have increased the range of options available for early intensification of treatment of type 2 diabetes. In combination with more established therapies, there are more opportunities than ever to accommodate patient preferences while improving glycemic control and harnessing extraglycemic benefits of a second (or third) agent. Topics: Algorithms; Carbamates; Diabetes Mellitus, Type 2; Dipeptidyl-Peptidase IV Inhibitors; Drug Therapy, Combination; Exenatide; Glucagon-Like Peptide 1; Glucagon-Like Peptide-1 Receptor; Humans; Hypoglycemic Agents; Incretins; Insulin; Liraglutide; Metformin; Peptides; Piperidines; Practice Guidelines as Topic; Receptors, Glucagon; Sulfonylurea Compounds; Thiazolidinediones; Venoms | 2013 |
Diabetes remission following metabolic surgery: is GLP-1 the culprit?
The parallel occurrence of improved glucose tolerance and increased glucagon-like peptide 1 (GLP-1) response to meal intake following metabolic surgery (MS) demonstrated in several studies has led to the notion that GLP-1 is the culprit for the impressive rates of remission of type 2 diabetes mellitus (T2DM) following MS. In this article, we critically review current evidence supporting this view. Recent studies specifically designed to elucidate a causative role of GLP-1 in the antidiabetic effects of MS call into question GLP-1 as a key player for T2DM outcome following MS procedures such as Roux-en-Y gastric bypass and sleeve gastrectomy in morbidly obese subjects. Whether GLP-1 plays a more prominent role in the remission of T2DM following MS in subjects with moderate obesity warrants further studies. Appraisal of the mechanisms involved in the amelioration of hyperglycemia following MS is a priority, as it could help in the battle against the current combined epidemics of obesity and T2DM. Topics: Animals; Bariatric Surgery; Diabetes Mellitus, Type 2; Glucagon-Like Peptide 1; Humans; Obesity; Remission Induction; Treatment Outcome | 2013 |
Rationale use of GLP-1 receptor agonists in patients with type 1 diabetes.
Clinicians and patients are rapidly adapting GLP-1 receptor agonists as efficacious and safe therapeutic options for managing type 2 diabetes (T2DM). GLP-1 receptor agonists stimulate insulin production and secretion from the pancreatic β cells in a glucose-dependent manner, improve gastric emptying, favor weight reduction, and reduce postabsorptive glucagon secretion from pancreatic α cells. GLP-1 receptor activity is impaired in patients with T2DM. GLP-1 secretion and subsequent physiologic actions in patients with type 1 diabetes (T1DM) is ill-defined. Some researchers have suggested that the use of GLP-1 receptor agonists in T1DM may reduce excessive postprandial glucagon secretion allowing patients to reduce their total daily dose of exogenous insulin. Hypoglycemia risk may also be minimized in T1DM as glucagon counter-regulation can be preserved to some degree via the glucose-dependent action of the GLP-1 receptor agonists. This paper will consider the physiologic and pharmacologic benefits of adding GLP-1 receptor agonists to therapeutic regimens of patients with T1DM. Topics: Diabetes Mellitus, Type 1; Diabetes Mellitus, Type 2; Glucagon-Like Peptide 1; Glucagon-Like Peptide-1 Receptor; Humans; Hypoglycemia; Off-Label Use; Receptors, Glucagon | 2013 |
Early use of glucagon-like peptide-1 receptor agonists (GLP-1 RAs) in type 2 diabetes.
To evaluate the efficacy and safety of the available glucagon-like peptide-1 receptor agonists (GLP-1 RAs) exenatide and liraglutide (marketed as Byetta * and Victoza † , respectively) in first- or second-line pharmacotherapy for type 2 diabetes (T2D), described here as 'early use'.. MEDLINE, EMBASE and Google Scholar databases were queried for clinical trial reports using the terms incretin, GLP-1, exenatide and liraglutide. Relevant articles were those that employed these agents in treatment-naïve patients with T2D and in patients who had failed on metformin monotherapy. Additional targeted searches were conducted on diabetes treatment guidelines and on the range of physiological responses to GLP-1 RAs. Most evidence is level I and II.. Effective therapy for T2D should be implemented early in the course of this progressive disease. The recently revised 2013 Canadian Diabetes Association (CDA) guidelines now identify the GLP-1 RAs among various injected and oral agents recommended for the management of T2D. The rationale for early use of GLP-1 RAs in T2D management is manifold: these agents offer effective management of hyperglycemia in early-stage T2D, minimal risk of hypoglycemia, weight loss, improvement in multiple non-glycemic cardiovascular risk factors, and potential enhancement of patient adherence to antihyperglycemic treatment. Available data from clinical trials support second-line use of GLP-1 RAs among patients who fail on metformin, as well as first-line use of these agents in a subset of T2D patients.. The ability to achieve glycemic targets using GLP-1 RAs while simultaneously avoiding hypoglycemia and weight gain could provide substantial reassurance to physicians and patients who might otherwise resist the transition to injected therapies. Exenatide and liraglutide represent appropriate second-line choices for pharmacological treatment of T2D, as indicated in the 2013 CDA guidelines. Topics: Diabetes Complications; Diabetes Mellitus, Type 2; Exenatide; Female; Glucagon-Like Peptide 1; Humans; Hypoglycemic Agents; Liraglutide; Male; MEDLINE; Peptides; Venoms | 2013 |
The rationale for combining GLP-1 receptor agonists with basal insulin.
• Type 2 diabetes mellitus (T2DM) is progressive; the more intensively it is treated, the greater is the risk of hypoglycaemia and weight gain. Achieving treatment intensification while mitigating these risks presents a challenge to patient management. • Basal insulins provide control of fasting glucose; however, their utility in the control of postprandial glucose excursions is limited. • Glucagon-like peptide-1 (GLP-1) receptor agonists stimulate glucose-medicated insulin secretion, suppress glucagon secretion, delay gastric emptying and decrease appetite. Use of GLP-1 receptor agonists in combination therapy with basal insulin offers an alternative approach to intensification of insulin therapy. • Prospective interventional trials demonstrate that GLP-1 receptor agonists added to basal insulin decrease postprandial glucose levels, lower HbA1c levels, decrease weight and lower basal insulin requirements without increasing the risk of major hypoglycaemic events. • The current clinical data are limited by the lack of any data on the long-term effects of GLP-1 receptor agonists over additional prandial regimens; they may be beneficial or deleterious. • Although cost, gastrointestinal side effects and long-term safety should be taken into account when considering this combination, it appears to be growing in popularity and is likely to be an important therapeutic option for T2DM in the future. Topics: Blood Glucose; Diabetes Mellitus, Type 2; Drug Administration Schedule; Drug Therapy, Combination; Evidence-Based Medicine; Glucagon-Like Peptide 1; Humans; Hypoglycemic Agents; Insulin, Long-Acting; Precision Medicine; Randomized Controlled Trials as Topic; Treatment Outcome | 2013 |
Obesity and weight management in the elderly: a focus on men.
The rising rate of overweight/obesity among the ever-growing ageing population is imposing massive and rapidly changing burdens of ill health. The observation that the BMI value associated with the lowest relative mortality is slightly higher in older than in younger adults, mainly through its reduced impact on coronary heart disease, has often been misinterpreted that obesity is not as harmful in the elderly, who suffer a large range of disabling consequences of obesity. All medical consequences of obesity are multi-factorial and most alleviated by modest, achievable weight loss (5-10 kg) with an evidence-based maintenance strategy. But severe obesity, e.g. BMI >40 may demand greater weight loss e.g. >15 kg to reverse type 2 diabetes. Since relatively reduced physical activity and reduced muscle mass (sarcopenic obesity) are common in the elderly, combining exercise and modest calorie restriction optimally reduces fat mass and preserves muscle mass - age presents no obstacle and reducing polypharmacy is a valuable outcome. The currently licensed drug orlistat has no age-related hazards and is effective in a low fat diet, but the risks from bariatric surgery begin to outweigh benefits above age 60. For the growing numbers of obese elderly with diabetes, the glucagon-like peptide-1 (GLP-1) receptor analogue liraglutide appears a safe way to promote and maintain substantial weight loss. Obesity and sarcopenia should be prevented from younger age and during life-transitions including retiral to improve future health outcomes and quality of life, with a focus on those in "obese families". Topics: Adult; Aged; Bariatric Surgery; Body Composition; Cardiovascular Diseases; Diabetes Mellitus, Type 2; Europe; Glucagon-Like Peptide 1; Humans; Life Style; Liraglutide; Male; Metabolic Syndrome; Middle Aged; Morbidity; Obesity; Prevalence; Quality of Life; Sarcopenia; Waist Circumference; Weight Loss | 2013 |
Gut hormones as therapeutic agents in treatment of diabetes and obesity.
Obesity and Type 2 Diabetes Mellitus (T2DM) present an ever-increasing threat to global health. Although bariatric surgery is an effective treatment, it cannot be applied to the vast majority of patients. The beneficial effects of bariatric surgery are related to complex alterations in the secretion of gut hormones. By recapitulation of the changes of gut hormone secretion after bariatric surgery, drugs based on gut hormones represent an exciting possibility for the treatment of T2DM and obesity. We review the rapidly emerging role of GLP-1 based treatments as well as the future for new drugs based on other gut hormones such as GIP, ghrelin, oxyntomodulin and peptide YY. Topics: Animals; Diabetes Mellitus, Type 2; Gastrointestinal Hormones; Glucagon-Like Peptide 1; Humans; Obesity | 2013 |
[The role of glucagon-like peptide-1 and its receptor in the mechanism of metabolic surgery].
At present, surgery has become one of the treatments for type 2 diabetes, but it is still unclear about the therapeutic mechanism. Many experiments has proved that the anatomical and physiological structure has been altered leading to significant changes related to the secretion of gastrointestinal hormones and neuropeptides. These molecular are related to the metabolism of glucose, functions of islet cells and sensitivity of insulin. Intensive studies of glucagon-like peptide-1 (GLP-1) play an important role in the surgical treatment of diabetes and now it has gained increasing recognition. However, GLP-1 must be combined with GLP-1 receptor (GLP-1R) to execute its function. In this paper we reviewed the role of GLP-1 and its receptor in the mechanism of metabolic surgery. Topics: Diabetes Mellitus, Type 2; Glucagon-Like Peptide 1; Glucagon-Like Peptide-1 Receptor; Humans; Receptors, Glucagon | 2013 |
The potential risks of pancreatitis and pancreatic cancer with GLP-1-based therapies are far outweighed by the proven and potential (cardiovascular) benefits.
Recent suggestions that glucagon-like peptide-1 (GLP-1)-based therapies could cause pancreatitis, and even pancreatic cancer, are based on:. The worrying histological changes are not reproduced in all studies and are unexpectedly variable with different GLP-1-based therapies.. Singh's findings that pancreatitis is doubled with GLP-1-based therapies could relate to their use in obese patients who are prone to pancreatitis risk factors--gallstones and hypertriglyceridaemia. The other observational studies do not find an association between GLP-1-based therapies and pancreatitis.. The increased reports of pancreatitis and pancreatic cancer are likely to be attributable to 'notoriety bias'.. Butler's findings for those on GLP-1-based therapies vs. those not, could have other explanations. Meanwhile: META ANALYSIS: Randomized control trials with GLP-1-based therapies do not find increased pancreatitis risk. Meta-analysis of 53 randomized controlled trials including 20 212 dipeptidyl peptidase-4 inhibitor-treated patients found a significantly reduced risk of major adverse cardiovascular events [odds ratio 0.689 (0.528-0.899), P = 0.006] for dipeptidyl peptidase-4 inhibitors compared with control subjects.. The evidence suggests that there is more than a possibility that some of the GLP-1 receptor agonists, and possibly also some dipeptidyl peptidase-4 inhibitors, may be associated with reduced cardiovascular events. Eight ongoing long-term cardiovascular randomized controlled trials will report from September 2013 onwards. These trials should resolve the issue of pancreatitis risk and substantiate the extent of benefit.. Whilst we should remain vigilant, currently the balance of evidence is strongly in support of GLP-1-based therapy, with benefits far outweighing potential risks. Topics: Adverse Drug Reaction Reporting Systems; Cardiovascular Diseases; Diabetes Mellitus, Type 2; Diabetic Angiopathies; Dipeptidyl-Peptidase IV Inhibitors; Exenatide; Female; Glucagon-Like Peptide 1; Glucagon-Like Peptide-1 Receptor; Humans; Incretins; Liraglutide; Male; Pancreatic Neoplasms; Pancreatitis; Patient Selection; Peptides; Randomized Controlled Trials as Topic; Receptors, Glucagon; Risk Assessment; Risk Factors; Venoms | 2013 |
Incretin based therapies: bone protective effects.
Type 2 Diabetes Mellitus (T2D) and osteoporosis have been found recently to be tightly correlated. In fact, T2D can result in bone loss through different mechanisms resulting in alteration of bone matrix and inhibition of bone formation. Fracture risk also increases significantly. New antidiabetic agents, dipeptidyl peptidase-4 inhibitors and glucagon like peptide -1 agonists have shown promise in many fields beyond glycemic control. Benefits on the skeletal system are multiple through direct stimulation of osteoblasts, inhibition of advanced glycation end products and inhibition of bone resorption. However, clinical evidence in humans is still not enough to allow definitive conclusions. Topics: Animals; Blood Glucose; Bone Density; Bone Density Conservation Agents; Diabetes Mellitus, Type 2; Dipeptidyl-Peptidase IV Inhibitors; Glucagon-Like Peptide 1; Humans; Hypoglycemic Agents; Incretins; Osteoporosis | 2013 |
Differential effects of GLP-1 receptor agonists on components of dysglycaemia in individuals with type 2 diabetes mellitus.
Metabolic consequences of glucagon-like peptide-1 receptor agonists (GLP-1 RAs) are the result of enhanced glucose-stimulated insulin secretion, inhibition of glucagon release, delayed gastric emptying and increased satiety. These attributes make GLP-1 agonists a treatment option in type 2 diabetes mellitus (T2DM). To optimise treatment choice, a detailed understanding of the effects of GLP-1 RAs on glucose homeostasis in individuals with T2DM is necessary. Although the various GLP-1 RAs share the same basic mechanisms of action, differences in pharmacokinetic/pharmacodynamic characteristics translate into differential effects on parameters of glycaemia. Head-to-head comparisons between long-acting non-prandial (liraglutide once daily and exenatide once weekly) and shorter-acting prandial (exenatide twice daily and lixisenatide once daily prandial) GLP-1 RAs confirm their differential effects on fasting plasma glucose (FPG) and post-prandial glucose (PPG). Liraglutide once daily and exenatide once weekly demonstrate greater reductions in FPG but lesser impacts on PPG excursions plasma than exenatide twice daily. Prandial GLP-1 RAs have a profound effect on post-prandial glycaemia, mediated by delaying gastric emptying, which is not subject to the tachyphylaxis occurring due to the sustained elevated plasma GLP-1 concentrations after treatment with long-acting GLP-1 RAs. Lixisenatide once-daily prandial, in contrast to liraglutide, strongly suppresses post-prandial glucagon secretion, further contributing to the more pronounced PPG-lowering effect found with lixisenatide. Evidence suggests that the GLP-1 RAs that predominantly target the prandial glucose excursions, such as exenatide twice daily and lixisenatide once-daily prandial, are therefore best used as combination therapy with basal insulin and will form an important new treatment option for individuals with T2DM. Topics: Blood Glucose; Diabetes Mellitus, Type 2; Drug Administration Schedule; Drug Therapy, Combination; Exenatide; Glucagon-Like Peptide 1; Glucagon-Like Peptide-1 Receptor; Glycated Hemoglobin; Humans; Hypoglycemic Agents; Insulin; Liraglutide; Peptides; Receptors, Glucagon; Venoms | 2013 |
Complications of diabetes therapy.
Current strategies for the treatment of type 2 diabetes mellitus promote individualized plans to achieve target glucose levels on a patient-by-patient basis while minimizing treatment related risks. Maintaining glycemic control over time is a significant challenge because of the progressive nature of diabetes as a result of declining β-cell function. This article identifies complications of non-insulin treatments for diabetes. The major classes of medications are reviewed with special focus on target population, mechanism of action, effect on weight, cardiovascular outcomes and additional class-specific side effects including effects on bone. Effects on β-cell function are also highlighted. Topics: Biguanides; Diabetes Mellitus, Type 2; Glucagon-Like Peptide 1; Glycoside Hydrolase Inhibitors; Humans; Hypoglycemic Agents; Insulin Resistance; Insulin-Secreting Cells; Islet Amyloid Polypeptide; Sulfonylurea Compounds; Thiazolidinediones | 2013 |
Antidiabetic drugs and their potential role in treating mild cognitive impairment and Alzheimer's disease.
The incidence of both diabetes mellitus (DM) and dementia increases with aging and the incidence of dementia are higher in people with diabetes. Epidemiological and pathological data suggest that DM contributes to mild cognitive impairment (MCI) and dementia. DM seems to be an independent risk factor for MCI and Alzheimer's disease (AD) and is associated with more rapid cognitive decline. Recent evidence points out that insulin affects central nervous system functions, and can modulate cognitive functions. Impaired insulin signaling and insulin resistance in brain have been found to play an important role in the pathogenesis of AD. Human studies have shown that some oral antidiabetic medications can improve cognition in patients with MCI and AD. Intranasal insulin has also been shown to improve memory and cognitive abilities in MCI and AD patients. While it remains unclear whether management of diabetes will reduce the incidence of MCI and AD, emerging evidence suggests that diabetes therapies may improve cognitive function. Topics: Aged; Aged, 80 and over; Aging; Alzheimer Disease; Animals; Clinical Trials as Topic; Cognition Disorders; Diabetes Complications; Diabetes Mellitus, Type 2; Dipeptidyl-Peptidase IV Inhibitors; Disease Progression; Glucagon-Like Peptide 1; Humans; Hypoglycemic Agents; Insulin; Metformin; Middle Aged; Risk Factors; Sulfonylurea Compounds; Thiazolidinediones | 2013 |
Developments of glucagon like peptide-1 (GLP-1) and long-acting analogs in clinical and preclinical studies for treatment of type 2 diabetes.
The outstanding physiological functions of glucagon-like peptide-1 make it a promising drug candidate for blood glucose regulation in type 2 diabetes. However, the short half-life of GLP-1 limited its widely clinical utility due to the rapid degradation by dipeptidyl peptidase IV (DPP-IV) and renal clearance. Therefore, stabilisation of glucagon-like peptide-1 is critical for the use of this peptide in drug development. Scientists in pharmaceutical companies have contributed in years to obtain long-acting or sustained GLP-1 derivatives which are reviewed in this report. Topics: Animals; Delayed-Action Preparations; Diabetes Mellitus, Type 2; Glucagon-Like Peptide 1; Humans; Hypoglycemic Agents; Structure-Activity Relationship | 2013 |
[Type 2 diabetes mellitus and obesity: should we treat the obesity or the diabetes?].
In this article, we review the results that can be expected after significant weight loss in patients with type 2 diabetes mellitus. We provide consensus-based documentation supported by the American Diabetes Association, the European Association for the Study of Diabetes, and the International Diabetes Federation on the importance of physical exercise, metabolic-bariatric surgery, and drug therapy. Lastly, we report the results of studies published in the last few years on glucagon-like peptide-1 analogs and the new family of oral drugs known as gliflozins, specifically studies published on dapagliflozin. Topics: Bariatric Surgery; Benzhydryl Compounds; Causality; Comorbidity; Diabetes Mellitus, Type 2; Diet, Diabetic; Diet, Reducing; Disease Management; Evidence-Based Medicine; Exercise Therapy; Glucagon-Like Peptide 1; Glucosides; Humans; Hyperinsulinism; Hypoglycemic Agents; Insulin Resistance; Metabolic Syndrome; Obesity; Practice Guidelines as Topic; Sodium-Glucose Transporter 2; Sodium-Glucose Transporter 2 Inhibitors; Weight Loss | 2013 |
[Limitations of insulin-dependent drugs in the treatment of type 2 diabetes mellitus].
In this study, we review the efficacy and safety limitations of insulin-dependent oral antidiabetic agents. In terms of efficiency, the main drawback of metformin, sulfonylureas, gliptins and -to a lesser extent-glitazones is durability. No drug per se is able to maintain stable blood glucose control for years. Metformin, sulfonylureas and gliptins have demonstrated safety. Experience with the first two drug groups is more extensive. The main adverse effect of metformin is gastrointestinal discomfort. Major concerns related to the use of sulfonylureas are hypoglycemia and weight gain. The use of pioglitazone has been associated with an increased risk of bladder cancer, edema, heart failure, weight gain, and distal bone fractures in postmenopausal women. The most common adverse reactions associated with glucagon-like peptide-1 agonists are gastrointestinal discomfort that sometimes leads to treatment discontinuation. Topics: Contraindications; Diabetes Mellitus, Type 2; Dipeptidyl-Peptidase IV Inhibitors; Drug Therapy, Combination; Drug Tolerance; Fractures, Spontaneous; Gastrointestinal Diseases; Glucagon-Like Peptide 1; Heart Failure; Humans; Hypoglycemia; Hypoglycemic Agents; Insulin; Insulin Resistance; Insulin Secretion; Metformin; Pioglitazone; Sulfonylurea Compounds; Thiazolidinediones; Urinary Bladder Neoplasms; Weight Gain | 2013 |
Cardiovascular effects of incretins in diabetes.
Recent years have seen an enormous increase in the number of therapeutic agents available for lowering blood glucose levels in people with type 2 diabetes. Among these agents, the incretin mimetics glucagon-like peptide-1 (GLP-1) receptor (GLP-1R) agonists and dipeptidyl peptidase 4 (DPP4) inhibitors have received particular attention for the potential of these interventions to positively impact on cardiovascular outcomes. Although the results of large-scale cardiovascular outcome trials eagerly are anticipated, an increasing body of literature from preclinical and early phase clinical studies has indicated that both GLP-1R agonists and DPP4 inhibitors may exert glucose-independent cardiovascular effects. Despite its role in glucose homeostasis, the GLP-1R is surprisingly widely distributed throughout the body, including in the heart. GLP-1 may exert its effects through both receptor-dependent and receptor-independent mechanisms and through the actions of both the intact peptide and its metabolites. In addition, DPP4 inhibition not only augments the circulating levels of incretin hormones, but it also holds the capacity to augment the activity of other biologically important substrates, most notably the small protein stromal cell-derived factor 1 alpha. Whether these collective functions will act to reduce cardiovascular events in patients remains to be determined. Topics: Cardiovascular Diseases; Diabetes Mellitus, Type 2; Diabetic Angiopathies; Dipeptidyl-Peptidase IV Inhibitors; Endothelium, Vascular; Exenatide; Female; Glucagon-Like Peptide 1; Humans; Hypoglycemic Agents; Incretins; Liraglutide; Male; Myocytes, Cardiac; Peptides; Treatment Outcome; Venoms | 2013 |
[The cutting-edge of medicine; glucagon renaissance].
Topics: Animals; Blood Glucose; Diabetes Mellitus, Type 2; Glucagon; Glucagon-Like Peptide 1; Humans; Insulin; Insulin-Secreting Cells | 2013 |
[Surgery for morbid obesity and diabetes mellitus--from bariatric surgery to metabolic surgery].
Topics: Asian People; Bariatric Surgery; Diabetes Mellitus, Type 2; Gastrectomy; Gastric Bypass; Glucagon-Like Peptide 1; Humans; Insulin; Insulin Resistance; Insulin Secretion; Laparoscopy; Obesity, Morbid | 2013 |
Insulin vs GLP-1 analogues in poorly controlled Type 2 diabetic subjects on oral therapy: a meta-analysis.
To compare insulin and GLP-1 analogues therapy on glycemic control in poorly controlled Type 2 diabetes (T2DM) subjects failing on oral therapy.. The electronic database PubMed was systematically searched for randomized controlled trial (RCT) with duration >16 weeks comparing the addition of insulin therapy vs glucagon-like peptide (GLP-1) analogues in poorly controlled T2DM subjects on oral therapy.. We identified 7 RCT with 2199 patients of whom 1119 were assigned to insulin therapy and 1080 received a GLP-1 analogue. Both insulin and GLP-1 analogues were effective in lowering glycated hemoglobin (HbA(1c)) with no statistically significant difference between the mean decreases in HbA(1c). However, insulin was more effective than GLP-1 analogues in lowering the fasting plasma glucose concentration, while GLP-1 agonists were more effective in lowering the postprandial glucose concentration. Insulin therapy was associated with weight gain while GLP-1 analogues consistently caused weight loss and the difference between the mean change in body weight between the two therapies was highly statistically significant. Despite a similar decrease in HbA(1c), the risk of hypoglycemia was 35% lower (p=0.001) with GLP-1 therapy compared to insulin. Compared to insulin, GLP-1 analogues caused a significant decrease in systolic blood pressure and were associated with greater rate of gastrointestinal adverse events.. In poorly controlled T2DM subjects on oral therapy, GLP-1 analogues and insulin are equally effective in lowering the HbA(1c). However, GLP-1 analogues have additional non-glycemic benefits and lower risk of hypoglycemia. Thus, GLP-1 analogues should be considered as a treatment option in this group of diabetic individuals. Topics: Administration, Oral; Blood Glucose; Blood Pressure; Body Weight; Diabetes Mellitus, Type 2; Gastrointestinal Diseases; Glucagon-Like Peptide 1; Humans; Hypoglycemic Agents; Insulin; Lipids; Middle Aged; Randomized Controlled Trials as Topic; Treatment Failure | 2013 |
Combining GLP-1 receptor agonists with insulin: therapeutic rationales and clinical findings.
Due to the increasing prevalence of type 2 diabetes mellitus (T2DM), the emergent trend towards diagnosis in younger patients and the progressive nature of this disease, many more patients than before now require insulin to maintain glycaemic control. However, there is a degree of inertia among physicians and patients regarding the initiation and intensification of insulin therapy, in part due to concerns about the associated weight gain and increased risk of hypoglycaemia. Glucagon-like peptide-1 receptor agonists (GLP-1RAs) increase insulin release and suppress glucagon secretion in a glucose-dependent manner, thus conferring glycaemic control with a low incidence of hypoglycaemia. GLP-1RAs also promote weight loss, and have beneficial effects on markers of β cell function, lipid levels, blood pressure and cardiovascular risk markers. However, the durability of their effectiveness is unknown and, compared with insulin, the antihyperglycaemic efficacy of GLP-1RAs is limited. The combination of a GLP-1RA and insulin might thus be highly effective for optimal glucose control, ameliorating the adverse effects typically associated with insulin. Data from clinical studies support the therapeutic potential of GLP-1RA-insulin combination therapy, typically showing beneficial effects on glycaemic control and body weight, with a low incidence of hypoglycaemia and, in established insulin therapy, facilitating reductions in insulin dose. In this review, the physiological and pharmacological rationale for using GLP-1RA and insulin therapies in combination is discussed, and data from clinical studies that have assessed the efficacy and safety of this treatment strategy are outlined. Topics: Blood Glucose; Diabetes Mellitus, Type 2; Drug Administration Schedule; Drug Therapy, Combination; Exenatide; Female; Glucagon-Like Peptide 1; Glycated Hemoglobin; Humans; Hypoglycemic Agents; Insulin; Liraglutide; Male; Peptides; Treatment Outcome; Venoms; Weight Gain | 2013 |
Combination therapies of DPP4 inhibitors and GLP1 analogues with insulin in type 2 diabetic patients: a systematic review.
The use of dipeptidyl-peptidase 4 (DPP4) inhibitors and glucagon like peptide 1 (GLP1) analogues for the treatment of diabetic mellitus (DM) type 2 is growing. Currently some of these agents have been approved in combination with insulin.. We considered randomised controlled trials (RCTs) evaluating GLP1 analogues or DDP4 inhibitors combined with basal insulin in diabetic patients. We were limited to trials published in English language.. PubMed search retrieved 207 items. After excluding irrelevant items we ended with 7 eligible studies with 1808 participants. Mean baseline HbA1c was 8.5% and median follow up was 24 weeks. Exenatide combined with insulin was used in 2 studies; DPP4 inhibitors were used in 5 studies (2 with sitagliptin, 1 with saxagliptin, 1 with vildagliptin and 1 with alogliptin).. Incretin-based therapies combined with basal insulin are able to reduce HbA1c by 0.5-0.7%. DPP4 inhibitors have no significant effect on weight, whereas GLP1 analogues reduced weight by 1-2 kg. Hypoglycaemia rates were generally comparable in all treatment groups. These are promising results, but the available evidence is limited. This is a poorly investigated field with few RCTs. New studies focusing on head-to-head comparisons with short-acting insulin on top of basal insulin are needed. Topics: Diabetes Mellitus, Type 2; Dipeptidyl-Peptidase IV Inhibitors; Drug Therapy, Combination; Glucagon-Like Peptide 1; Humans; Hypoglycemic Agents; Insulin; Randomized Controlled Trials as Topic | 2013 |
Cardiovascular effects of GLP-1 and GLP-1-based therapies: implications for the cardiovascular continuum in diabetes?
Glucagon-like peptide-1 receptor agonists and inhibitors of dipeptidyl peptidase-4 that increase glucagon-like peptide-1 plasma concentrations are current treatment options for patients with diabetes mellitus. As patients with diabetes are a high-risk population for the development of a severe and diffuse atherosclerosis, we aim to review the potential action of these drugs on cardiovascular disease and to summarize the potential role of present glucagon-like peptide-1-based therapies from a cardiologist's point of view.. Using a PubMed/MEDLINE search without language restriction, studies were identified and evaluated in order to review the effects of glucagon-like peptide-1-based therapy on different stages of the cardiovascular continuum.. Recent experimental as well as clinical data suggest that dipeptidyl peptidase-4 inhibitors and glucagon-like peptide-1 receptor agonists--in addition to their metabolic effects--may have beneficial effects on the cardiovascular continuum at multiple stages, including: (1) cardiovascular risk factors; (2) molecular mechanisms involved in atherogenesis; (3) ischaemic heart disease; and (4) heart failure. Furthermore, retrospective analysis suggested decreased cardiovascular events in patients with glucagon-like peptide-1-based therapies.. There are ample data to suggest beneficial effects of glucagon-like peptide-1-based therapies on the cardiovascular continuum and large-scale clinical trials are warranted to determine whether these effects translate into improved cardiovascular endpoints in humans. Topics: Animals; Atherosclerosis; Clinical Trials as Topic; Diabetes Mellitus, Type 2; Diabetic Angiopathies; Diabetic Cardiomyopathies; Dipeptidyl-Peptidase IV Inhibitors; Dogs; Endothelium, Vascular; Glucagon-Like Peptide 1; Glucagon-Like Peptide-1 Receptor; Heart Failure; Humans; Hypoglycemic Agents; Mice; Myocardium; Obesity; Rats; Receptors, Glucagon; Risk Factors; Swine | 2013 |
A network meta-analysis to compare glycaemic control in patients with type 2 diabetes treated with exenatide once weekly or liraglutide once daily in comparison with insulin glargine, exenatide twice daily or placebo.
The glucagon-like peptide-1 receptor agonists (GLP-1 RAs) exenatide once weekly (ExQW) and liraglutide once daily (QD) are indicated to improve glycaemic control in patients with type 2 diabetes. Although glycaemic control with ExQW versus liraglutide QD 1.8 mg has been directly compared, no studies have compared ExQW with liraglutide QD 1.2 mg or determined the probable relative efficacies of various injectable therapies for glycaemic control; therefore, a network meta-analysis was performed to address these questions.. A systematic review identified randomized controlled trials of ≥24 weeks that compared ExQW, liraglutide QD (1.2 mg, 1.8 mg), insulin glargine, exenatide twice daily (ExBID), or placebo. Twenty-two studies evaluating 11 049 patients were included in the network meta-analysis. Mean differences in HbA1c relative to placebo or each other and probability rankings were estimated.. Estimated mean differences in HbA1c versus placebo were -1.15% (95% CrI: -1.31 to -1.00) for ExQW, -1.01% (95% CrI: -1.18 to -0.85) for liraglutide 1.2 mg, and -1.18% (95% CrI: -1.32 to -1.04) for liraglutide 1.8 mg. HbA1c differences for ExQW versus liraglutide 1.2 mg and 1.8 mg were -0.14% (95% CrI: -0.34 to 0.06) and 0.03% (95% CrI: -0.14 to 0.18), respectively. The estimated mean difference in HbA1c between liraglutide 1.2 mg and 1.8 mg was 0.17% (95% CrI: 0.02-0.30). Results were consistent when adjusted for background antihyperglycaemic medications and diabetes duration.. This network meta-analysis did not identify meaningful differences in HbA1c lowering between ExQW and both liraglutide doses, suggesting that these GLP-1 RAs have similar glycaemic effects. Topics: Blood Glucose; Diabetes Mellitus, Type 2; Drug Administration Schedule; Exenatide; Female; Glucagon-Like Peptide 1; Glycated Hemoglobin; Humans; Hypoglycemic Agents; Insulin Glargine; Insulin, Long-Acting; Liraglutide; Male; Peptides; Treatment Outcome; Venoms | 2013 |
Long-term efficacy and safety comparison of liraglutide, glimepiride and placebo, all in combination with metformin in type 2 diabetes: 2-year results from the LEAD-2 study.
To investigate efficacy and safety of dual therapy with liraglutide and metformin in comparison to glimepiride and metformin, and metformin monotherapy over 2 years in patients with type 2 diabetes.. In the 26-week the Liraglutide Effect and Action in Diabetes (LEAD)-2 core trial, patients (n = 1091) were randomized (2 : 2 : 2 : 1: 2) to liraglutide (0.6, 1.2 or 1.8 mg once-daily), placebo or glimepiride; all with metformin. Patients were enrolled if they were 18-80 years old with HbA1c 7.0-11.0% (previous monotherapy ≥3 months), or 7.0-10.0% (previous combination therapy ≥3 months), and body mass index ≤40 kg/m(2) . Patients completing the 26-week double-blinded phase could enter an 18-month open-label extension.. HbA1c decreased significantly with liraglutide (0.4% with 0.6 mg, 0.6% with 1.2 and 1.8 mg) versus 0.3% increase with metformin monotherapy (p < 0.0001). HbA1c decrease with liraglutide was non-inferior versus 0.5% decrease with glimepiride. Liraglutide groups experienced significant weight loss (2.1, 3.0 and 2.9 kg with 0.6, 1.2 and 1.8 mg, respectively) compared to weight gain (0.7 kg) with glimepiride (p < 0.0001). Weight loss with liraglutide 1.2 and 1.8 mg was significantly greater than with metformin monotherapy (1.8 kg; p = 0.0185 and p = 0.0378 for 1.2 and 1.8 mg, respectively). The occurrence of minor hypoglycaemia was <5.0% in all liraglutide groups, significantly less than with glimepiride (24.0%; p < 0.0001). Liraglutide was well tolerated overall: gastrointestinal events were more common than with glimepiride or metformin monotherapy, but occurrence decreased with time.. Liraglutide provided sustained glycaemic control over 2 years comparable to that provided by glimepiride. Liraglutide was well tolerated, and was associated with weight loss and a low rate of hypoglycaemia. Topics: Adolescent; Adult; Aged; Aged, 80 and over; Blood Glucose; Body Mass Index; Diabetes Mellitus, Type 2; Double-Blind Method; Drug Therapy, Combination; Female; Glucagon-Like Peptide 1; Glycated Hemoglobin; Humans; Hypoglycemic Agents; Liraglutide; Male; Metformin; Middle Aged; Sulfonylurea Compounds; Weight Loss | 2013 |
Biochemical and metabolic mechanisms by which dietary whey protein may combat obesity and Type 2 diabetes.
Consumption of milk and dairy products has been associated with reduced risk of metabolic disorders and cardiovascular disease. Milk contains two primary sources of protein, casein (80%) and whey (20%). Recently, the beneficial physiological effects of whey protein on the control of food intake and glucose metabolism have been reported. Studies have shown an insulinotropic and glucose-lowering properties of whey protein in healthy and Type 2 diabetes subjects. Whey protein seems to induce these effects via bioactive peptides and amino acids generated during its gastrointestinal digestion. These amino acids and peptides stimulate the release of several gut hormones, such as cholecystokinin, peptide YY and the incretins gastric inhibitory peptide and glucagon-like peptide 1 that potentiate insulin secretion from β-cells and are associated with regulation of food intake. The bioactive peptides generated from whey protein may also serve as endogenous inhibitors of dipeptidyl peptidase-4 (DPP-4) in the proximal gut, preventing incretin degradation. Indeed, recently, DPP-4 inhibitors were identified in whey protein hydrolysates. This review will focus on the emerging properties of whey protein and its potential clinical application for obesity and Type 2 diabetes. Topics: Appetite; Cholecystokinin; Diabetes Mellitus, Type 2; Dipeptidyl Peptidase 4; Ghrelin; Glucagon-Like Peptide 1; Glucose; Humans; Incretins; Milk Proteins; Obesity; Peptide YY; Thermogenesis; Whey Proteins | 2013 |
Combination therapy with GLP-1 receptor agonists and basal insulin: a systematic review of the literature.
Treatment algorithms for type 2 diabetes call for intensification of therapy over time as the disease progresses and glycaemic control worsens. If diet, exercise and oral antihyperglycaemic medications (OAMs) fail to maintain glycaemic control then basal insulin is added and ultimately prandial insulin may be required. However, such an intensification strategy carries risk of increased hypoglycaemia and weight gain, both of which are associated with worse long-term outcomes. An alternative strategy is to intensify therapy by the addition of a short-acting glucagon-like peptide-1 receptor agonist (GLP-1 RA) rather than prandial insulin. Short-acting GLP-1 RAs such as exenatide twice daily are particularly effective at reducing postprandial glucose while basal insulin has a greater effect on fasting glucose, providing a physiological rationale for this complementary approach. This review analyzes the latest randomized controlled clinical trials of insulin/GLP-1 RA combination therapy and examines results from 'real-world' use of the combinations as reported through observational and clinical practice studies. The most common finding across all types of studies was that combination therapy improved glycaemic control without weight gain or an increased risk of hypoglycaemia. Many studies reported weight loss and a reduction in insulin use when a GLP-1 RA was added to existing insulin therapy. Overall, the relative degree of benefit to glycaemic control and weight was influenced by the insulin titration employed in conjunction with the GLP-1 RA. The greatest glycaemic benefits were observed in studies with structured titration of insulin to glycaemic targets while the greatest weight benefits were observed in studies with a protocol-specified focus on insulin sparing. The adverse event profile of GLP-1 RAs in the reviewed trials was similar to that reported with GLP-1 RAs as monotherapy or in combination with OAMs with gastrointestinal events being the most commonly reported. Topics: Blood Glucose; Diabetes Mellitus, Type 2; Disease Progression; Drug Administration Schedule; Drug Therapy, Combination; Exenatide; Female; Glucagon-Like Peptide 1; Glycated Hemoglobin; Humans; Hypoglycemia; Hypoglycemic Agents; Insulin; Male; Peptides; Randomized Controlled Trials as Topic; Risk Reduction Behavior; Treatment Outcome; Venoms; Weight Gain | 2013 |
An emerging role of dipeptidyl peptidase 4 (DPP4) beyond glucose control: potential implications in cardiovascular disease.
The introduction of dipeptidyl peptidase 4 (DPP4) inhibitors for the treatment of Type 2 diabetes acknowledges the fundamental importance of incretin hormones in the regulation of glycemia. Small molecule inhibitors of DPP4 exert their effects via inhibition of enzymatic degradation of glucagon-like peptide-1 (GLP-1) and glucose-dependent insulinotropic peptide (GIP). The widespread expression of DPP4 in tissues such as the vasculature and immune cells suggests that this protein may play a role in cardiovascular function. DPP4 is known to exert its effects via both enzymatic and non-enzymatic mechanisms. A soluble form of DPP4 lacking the cytoplasmic and transmembrane domain has also been recently recognized. Besides enzymatic inactivation of incretins, DPP4 also mediates degradation of many chemokines and neuropeptides. The non-enzymatic function of DPP4 plays a critical role in providing co-stimulatory signals to T cells via adenosine deaminase (ADA). DPP4 may also regulate inflammatory responses in innate immune cells such as monocytes and dendritic cells. The multiplicity of functions and targets suggests that DPP4 may play a distinct role aside from its effects on the incretin axis. Indeed recent studies in experimental models of atherosclerosis provide evidence for a robust effect for these drugs in attenuating inflammation and plaque development. Several prospective randomized controlled clinical trials in humans with established atherosclerosis are testing the effects of DPP4 inhibition on hard cardiovascular events. Topics: Animals; Blood Pressure; Cardiovascular Diseases; Cardiovascular System; Diabetes Mellitus, Type 2; Dipeptidyl Peptidase 4; Dipeptidyl-Peptidase IV Inhibitors; Gastric Inhibitory Polypeptide; Glucagon-Like Peptide 1; Humans; Incretins; Inflammation; Mice | 2013 |
GLP-1 agonists for type 2 diabetes: pharmacokinetic and toxicological considerations.
Within recent years, glucagon-like peptide 1 receptor agonists (GLP-1-RA) have emerged as a new treatment option for type 2 diabetes. The GLP-1-RA are administered subcutaneously and differ substantially in pharmacokinetic profiles.. This review describes the pharmacokinetics and safety aspects of the currently available GLP-1 receptor agonists, liraglutide (based on the structure of native GLP-1), exenatide twice daily and exenatide once weekly (based on exendin-4) in relation to the kinetics and toxicology of native GLP-1. The review is based on electronic literature searches and legal documents in the form of assessment reports from the European Medicines Agency and the United States Food and Drug Administration.. GLP-1-based therapy combines several unique mechanisms of action and have the potential to gain widespread use in the fight against diabetes and obesity. The difference in chemical structure have strong implications for key pharmacokinetic parameters such as absorption and clearance, and eventually the safety and efficacy of the individual GLP-1-RA. The main safety concerns are pancreatitis and neoplasms, for which there are no identifiable differences in risk between the available agents. Antibody formation and injection site reactions are more frequent with the exendin-4-based compounds. The efficacy with regard to Hb(A1c) reduction is superior with the longer-acting agonists, whereas the shorter-acting GLP-1-RA seems to provide greater postprandial glucose control and lower tolerability as a possible consequence of less induction of tachyphylaxis. The future place of these agents will depend on the added safety and efficacy data in the several ongoing cardiovascular outcome trials. Topics: Animals; Diabetes Mellitus, Type 2; Exenatide; Glucagon-Like Peptide 1; Humans; Hypoglycemic Agents; Liraglutide; Pancreatitis; Peptides; Tachyphylaxis; Venoms | 2013 |
New strategy for the treatment of type 2 diabetes mellitus with incretin-based therapy.
Incretin-based therapy was first made available for the treatment of type 2 diabetes mellitus (T2DM) in the US in 2006 and in Japan in 2009. Four DPP-4 inhibitors and two GLP-1 analog/receptor agonists are currently available. The effects of incretin-based therapy are assumed to be exerted mainly through the hormonal and neuronal actions of one of the incretins, GLP-1, which is secreted from L cells localized in the small intestine. The benefits of this therapy over conventional sulfonylureas or insulin injections, such as fewer hypoglycemic events and reduced body weight gain, derive from the glucose-dependent insulinotropic effect. The protective effects of this therapy on vulnerable pancreatic β-cells and against micro/macroangiopathy in T2DM are also most welcome. Indications and/or contraindications for incretin-based therapy should be clarified by prospectively studying the experiences of Japanese T2DM patients undergoing this therapy in the clinical setting. Topics: Asian People; Diabetes Mellitus, Type 2; Dipeptidyl Peptidase 4; Dipeptidyl-Peptidase IV Inhibitors; Glucagon-Like Peptide 1; Glucagon-Like Peptide-1 Receptor; Humans; Hypoglycemic Agents; Incretins; Insulin-Secreting Cells; Japan; Receptors, Glucagon; Treatment Outcome | 2013 |
Specific actions of GLP-1 receptor agonists and DPP4 inhibitors for the treatment of pancreatic β-cell impairments in type 2 diabetes.
Type 2 diabetes occurs when the β-cells do not secrete enough insulin to counter balance insulin resistance. GLP-1 and GIP are insulinotropic peptides which are thought to benefit to β-cell physiology. On one hand sustained pharmacological levels of GLP-1 are achieved by subcutaneous administration of GLP-1 analogs while transient and lower physiological levels of GLP-1 are attained following DPP4 inhibitor (DPP4i) treatment. On the other hand, DPP4i increase GLP-1 concentration into the portal vein to recruit the gut-to brain-to pancreas axis which is not the case with injected analogs. Hence, these differences between GLP-1 analogs and DPP4i indicate that both strategies could differentially impact β-cell behavior. Here, we summarize the effects of GLP-1 analogs and DPP4i on β-cell physiology. We discuss the possibility that production of signaling molecules, such as cAMP, generated into the β-cells by native GLP-1 or pharmacological GLP-1 analogs may vary and engage different downstream signaling networks. Hence, deciphering which signaling networks are engaged following GLP-1 analogs or DPP4i administration appears to be critical to unveil the contribution of each treatment/strategy to engage β-cell cellular processes. Topics: Diabetes Mellitus, Type 2; Dipeptidyl Peptidase 4; Dipeptidyl-Peptidase IV Inhibitors; Glucagon-Like Peptide 1; Glucagon-Like Peptide-1 Receptor; Humans; Hypoglycemic Agents; Insulin; Insulin Secretion; Insulin-Secreting Cells; Receptors, Glucagon; Signal Transduction | 2013 |
Safety and efficacy of liraglutide in patients with type 2 diabetes and elevated liver enzymes: individual patient data meta-analysis of the LEAD program.
Non-alcoholic fatty liver disease has reached epidemic proportions in type 2 diabetes (T2D). Glucagon-like peptide-1 analogues are licensed in T2D, yet little data exist on efficacy and safety in liver injury.. To assess the safety and efficacy of 26-week liraglutide on liver parameters in comparison with active-placebo.. Individual patient data meta-analysis was performed using patient-level data combined from six 26-week, phase-III, randomised controlled T2D trials, which comprise the 'Liraglutide Effect and Action in Diabetes' (LEAD) program. The LEAD-2 sub-study was analysed to assess the effect on CT-measured hepatic steatosis.. Of 4442 patients analysed, 2241 (50.8%) patients had an abnormal ALT at baseline [mean ALT 33.8(14.9) IU/L in females; 47.3(18.3) IU/L in males]. Liraglutide 1.8 mg reduced ALT in these patients vs. placebo (-8.20 vs. -5.01 IU/L; P = 0.003), and was dose-dependent (no significant differences vs. placebo with liraglutide 0.6 or 1.2 mg). This effect was lost after adjusting for liraglutide's reduction in weight (mean ALT difference vs. placebo -1.41 IU/L, P = 0.21) and HbA1c (+0.57 IU/L, P = 0.63). Adverse effects with 1.8 mg liraglutide were similar between patients with and without baseline abnormal ALT. In LEAD-2 sub-study, liraglutide 1.8 mg showed a trend towards improving hepatic steatosis vs. placebo (liver-to-spleen attenuation ratio +0.10 vs. 0.00; P = 0.07). This difference was reduced when correcting for changes in weight (+0.06, P = 0.25) and HbA(1c) (0.00, P = 0.93).. Twenty-six weeks' liraglutide 1.8 mg is safe, well tolerated and improves liver enzymes in patients with type 2 diabetes. This effect appears to be mediated by its action on weight loss and glycaemic control. Topics: Alanine Transaminase; Blood Glucose; Diabetes Mellitus, Type 2; Fatty Liver; Female; Glucagon-Like Peptide 1; Humans; Hypoglycemic Agents; Liraglutide; Liver; Liver Function Tests; Male; Non-alcoholic Fatty Liver Disease; Randomized Controlled Trials as Topic; Treatment Outcome; Weight Loss | 2013 |
Clinical pearls for initiating and utilizing liraglutide in patients with type 2 diabetes.
This review presents clinical pearls for initiating liraglutide (Victoza®, Novo Nordisk Inc) therapy for the management of type 2 diabetes and selecting patients who will benefit from liraglutide therapy. Liraglutide, a once-daily glucagon-like peptide 1 receptor agonist, is Food and Drug Administration approved as an adjunct to diet and exercise to improve glycemic control in adults with type 2 diabetes. Liraglutide is effective for reducing hemoglobin A1c levels by 0.8% to 1.5% in patients with type 2 diabetes as monotherapy or in combination with other diabetic medications (such as metformin, sulfonylureas, rosiglitazone, or basal insulin) when compared with placebo and these other diabetic medications, including exenatide. Overweight or obese patients with type 2 diabetes or those with insulin resistance are good candidates for liraglutide therapy because liraglutide use is associated with weight loss (about 2%-4% of initial body weight) and improved β-cell function. The incidence of hypoglycemia with liraglutide is low; therefore, liraglutide would be a safe therapy choice for patients at risk or with a history of symptomatic or severe hypoglycemia. Nausea seems to be the most problematic adverse effect associated with liraglutide therapy, but it is usually transient and is minimized with dose titration. Topics: Clinical Trials as Topic; Diabetes Mellitus, Type 2; Glucagon-Like Peptide 1; Glucagon-Like Peptide-1 Receptor; Humans; Hypoglycemic Agents; Liraglutide; Nausea; Receptors, Glucagon | 2013 |
Discovery and development of exenatide: the first antidiabetic agent to leverage the multiple benefits of the incretin hormone, GLP-1.
The GLP-1 receptor agonist exenatide is synthetic exendin-4, a peptide originally isolated from the salivary secretions of the Gila monster. Exenatide was developed as a first-in-class diabetes therapy, with immediate- and extended-release formulations. In preclinical diabetes models, exenatide enhanced glucose-dependent insulin secretion, suppressed inappropriately elevated glucagon secretion, slowed gastric emptying, reduced body weight, enhanced satiety, and preserved pancreatic β-cell function. In clinical trials, both exenatide formulations reduced hyperglycemia in patients with type 2 diabetes mellitus (T2DM) and were associated with weight loss.. This article reviews the development of exenatide from its discovery and preclinical investigations, to the elucidation of its pharmacological mechanisms of action in mammalian systems. The article also presents the pharmacokinetic profiling and toxicology studies of exenatide, as well as its validation in clinical trials.. GLP-1 receptor agonists represent a new paradigm for the treatment of patients with T2DM. By leveraging incretin physiology, a natural regulatory system that coordinates oral nutrient intake with mechanisms of metabolic control, these agents address multiple core defects in the pathophysiology of T2DM. Studies have identified unique benefits including improvements in glycemic control and weight, and the potential for beneficial effects on the cardiometabolic system without the increased risk of hypoglycemia associated with insulin therapy. Peptide hormone therapeutics can offer significant advantages over small molecule drug targets when it comes to specificity, potency, and more predictable side effects. As exemplified by exenatide, injectable peptides can be important drugs for the treatment of chronic diseases, such as T2DM. Topics: Animals; Clinical Trials as Topic; Diabetes Mellitus, Type 2; Exenatide; Glucagon-Like Peptide 1; Humans; Hypoglycemic Agents; Incretins; Models, Animal; Peptides; Venoms | 2013 |
Evolution of exenatide as a diabetes therapeutic.
Type 2 diabetes (T2DM) is a disease of epidemic proportion associated with significant morbidity and excess mortality. Optimal glucose control reduces the risk of microvascular and possibly macrovascular complications due to diabetes. However, glycemic control is rarely optimal and several therapeutic interventions for the treatment of diabetes cause hypoglycemia and weight gain; some may exacerbate cardiovascular risk. Exenatide (synthetic exendin-4) is a glucagon- like peptide-1 receptor (GLP-1R) agonist developed as a first-in-class diabetes therapy. This review presents an overview of the evolution of exenatide as a T2DM treatment, beginning with the seminal preclinical discoveries and continuing through to clinical pharmacology investigations and phase 3 clinical trials. In patients with T2DM, exenatide enhanced glucose-dependent insulin secretion, suppressed inappropriately elevated glucagon secretion, slowed gastric emptying, and enhanced satiety. In controlled phase 3 clinical trials ranging from 12 to 52 weeks, 10-mcg exenatide twice daily (ExBID) reduced mean HbA1c by -0.8% to -1.7% as monotherapy or in combination with metformin (MET), sulfonylureas (SFU), and/or thiazolidinediones (TZD); with mean weight losses of -1.2 kg to -8.0 kg. In controlled phase 3 trials ranging from 24 to 30 weeks, a 2-mg once-weekly exenatide formulation (ExQW) reduced mean HbA1c by -1.3% to -1.9%, with mean weight reductions of -2.3 to -3.7 kg. Exenatide was generally well-tolerated. The most common side effects were gastrointestinal in nature, mild, and transient. Nausea was the most prevalent adverse event. The incidence of hypoglycemia was generally low. By building upon early observations exenatide was successfully developed into an effective diabetes therapy. Topics: Animals; Blood Glucose; Cardiovascular Diseases; Diabetes Mellitus, Type 2; Diabetic Angiopathies; Drug Therapy, Combination; Exenatide; Glucagon-Like Peptide 1; Glycated Hemoglobin; Humans; Hypoglycemic Agents; Metformin; Mice; Mice, Knockout; Models, Animal; Nausea; Peptides; Sulfonylurea Compounds; Thiazolidinediones; Venoms; Weight Loss | 2013 |
[Metabolic effects of bariatric surgery].
Bariatric surgery managing/preventing complications of severe overweight is nowadays widely accepted as a mainstay in the treatment of morbid obesity. Its role is particularly important in type 2 diabetes developing on the base of long-standing significant overweight. The glycemic control improves within days-weeks after these surgeries, when weight loss and reduction of the visceral fat mass is barely detectable. This short term effect is probably due to an increased secretion of glucagon-like peptide and, as a consequence, an improvement in hepatic insulin sensitivity as well as the whole body glucose uptake. Besides the prolonged glucagon-like peptide effects, the favourable long term effect of these operations - lasting for 10 years even after surgery - is the decrease of visceral fat mass and elimination of harmful influence of cytokines produced by the fatty tissue. The article overviews the metabolic effects of these procedures, their undoubted advantages and potential risks. Topics: Bariatric Surgery; Blood Glucose; Body Mass Index; Diabetes Mellitus, Type 2; Female; Gastric Bypass; Ghrelin; Glucagon-Like Peptide 1; Humans; Hungary; Insulin; Insulin Resistance; Intra-Abdominal Fat; Male; Obesity, Morbid; Peptide YY; United States; Weight Loss | 2013 |
Structural aspects of gut peptides with therapeutic potential for type 2 diabetes.
Gut hormones represent a niche subset of pharmacologically active agents that are rapidly gaining importance in medicine. Due to their exceptional specificity for their receptors, these hormones along with their analogues have attracted considerable pharmaceutical interest for the treatment of human disorders including type 2 diabetes. With the recent advances in the structural biology, a significant amount of structural information for these hormones is now available. This Minireview presents an overview of the structural aspects of these hormones, which have roles in physiological processes such as insulin secretion, as well as a discussion on the relevant structural modifications used to improve these hormones for the treatment of type 2 diabetes. Topics: Diabetes Mellitus, Type 2; Gastric Inhibitory Polypeptide; Gastrointestinal Hormones; Glucagon; Glucagon-Like Peptide 1; Humans; Pituitary Adenylate Cyclase-Activating Polypeptide; Vasoactive Intestinal Peptide | 2013 |
Crosstalk between diabetes and brain: glucagon-like peptide-1 mimetics as a promising therapy against neurodegeneration.
According to World Health Organization estimates, type 2 diabetes (T2D) is an epidemic (particularly in under development countries) and a socio-economic challenge. This is even more relevant since increasing evidence points T2D as a risk factor for Alzheimer's disease (AD), supporting the hypothesis that AD is a "type 3 diabetes" or "brain insulin resistant state". Despite the limited knowledge on the molecular mechanisms and the etiological complexity of both pathologies, evidence suggests that neurodegeneration/death underlying cognitive dysfunction (and ultimately dementia) upon long-term T2D may arise from a complex interplay between T2D and brain aging. Additionally, decreased brain insulin levels/signaling and glucose metabolism in both pathologies further suggests that an effective treatment strategy for one disorder may be also beneficial in the other. In this regard, one such promising strategy is a novel successful anti-T2D class of drugs, the glucagon-like peptide-1 (GLP-1) mimetics (e.g. exendin-4 or liraglutide), whose potential neuroprotective effects have been increasingly shown in the last years. In fact, several studies showed that, besides improving peripheral (and probably brain) insulin signaling, GLP-1 analogs minimize cell loss and possibly rescue cognitive decline in models of AD, Parkinson's (PD) or Huntington's disease. Interestingly, exendin-4 is undergoing clinical trials to test its potential as an anti-PD therapy. Herewith, we aim to integrate the available data on the metabolic and neuroprotective effects of GLP-1 mimetics in the central nervous system (CNS) with the complex crosstalk between T2D-AD, as well as their potential therapeutic value against T2D-associated cognitive dysfunction. Topics: Alzheimer Disease; Biomimetics; Brain; Central Nervous System; Diabetes Mellitus, Type 2; Exenatide; Glucagon-Like Peptide 1; Glucose; Humans; Insulin Resistance; Liraglutide; Peptides; Venoms | 2013 |
Extraglycemic effects of glp-1-based therapeutics: addressing metabolic and cardiovascular risks associated with type 2 diabetes.
To examine whether widespread tissue expression of the glucagon-like peptide (GLP)-1 receptor supports the possibility of differential effects of GLP-1-based therapeutics on cardiac function, blood pressure, food intake, gastric emptying, and other regulatory activities. GLP-1 receptor agonists (RAs) have demonstrated pleiotropic effects on overweight/obesity, hypertension, dyslipidemia, and cardiovascular (CV) disease. Food-regulatory effects have been demonstrated in preclinical and clinical trials, including reduced gastric motility and food intake leading to body weight reductions. Native GLP-1 and GLP-1 RAs have demonstrated cardioprotective effects in preclinical models.. Using PubMed, we performed a search of the recent literature on GLP-1 and GLP-1 RAs.. Preliminary clinical data indicate native GLP-1 has beneficial effects on endothelial cell function and vascular inflammation. Native GLP-1 and GLP-1 RAs have demonstrated renoprotective and antihypertensive effects, and reductions in lipid parameters. The GLP-1 RA liraglutide has also demonstrated positive effects on such markers of endothelial dysfunction as tumor necrosis factor-α and plasminogen activator inhibitor-1.. Preliminary data suggest GLP-1 RAs could benefit type 2 diabetes patients at risk for CV comorbidities. Additional studies are needed to confirm the extraglycemic and extrapancreatic effects and determine whether outcomes will translate into beneficial effects for patient care. Topics: Anti-Inflammatory Agents; Antihypertensive Agents; Blood Pressure; Cardiovascular Diseases; Diabetes Mellitus, Type 2; Diabetic Angiopathies; Endothelium, Vascular; Female; Gastric Emptying; Glucagon-Like Peptide 1; Glucagon-Like Peptide-1 Receptor; Humans; Hypoglycemic Agents; Male; Receptors, Glucagon; Risk Factors; Treatment Outcome; Weight Loss | 2013 |
[Impact of anti-diabetic therapy based on glucagon-like peptide-1 receptor agonists on the cardiovascular risk of patients with type 2 diabetes mellitus].
Anti-diabetic drugs have, in addition to their well-known glucose lowering-effect, different effects in the rest of cardiovascular factors that are associated with diabetes mellitus. Glucagon-like peptide-1 (GLP-1) receptor agonists have recently been incorporated to the therapeutic arsenal of type 2 diabetes mellitus. The objective of this review is to summarize the available evidence on the effect of the GLP-1 receptor agonists on different cardiovascular risk factors, mediated by the effect of GLP-1 receptor agonists on the control of hyperglycaemia and the GLP-1 receptor agonists effect on other cardiovascular risk factors (weight control, blood pressure control, lipid profile and all other cardiovascular risk biomarkers). In addition, we present the emerging evidence with regards to the impact that GLP-1 receptor agonists therapy could have in the reduction of cardiovascular events and the currently ongoing studies addressing this issue. Topics: Blood Glucose; Brain; Cardiovascular Diseases; Clinical Trials as Topic; Diabetes Mellitus, Type 2; Dyslipidemias; Exenatide; Gastric Emptying; Glucagon-Like Peptide 1; Heart; Humans; Hypertension; Hypoglycemic Agents; Insulin; Insulin Secretion; Islets of Langerhans; Liraglutide; Liver; Meta-Analysis as Topic; Obesity; Peptides; Risk; Venoms; Weight Loss | 2013 |
Recent advances in understanding GLP-1R (glucagon-like peptide-1 receptor) function.
Type 2 diabetes is a major global health problem and there is ongoing research for new treatments to manage the disease. The GLP-1R (glucagon-like peptide-1 receptor) controls the physiological response to the incretin peptide, GLP-1, and is currently a major target for the development of therapeutics owing to the broad range of potential beneficial effects in Type 2 diabetes. These include promotion of glucose-dependent insulin secretion, increased insulin biosynthesis, preservation of β-cell mass, improved peripheral insulin sensitivity and promotion of weight loss. Despite this, our understanding of GLP-1R function is still limited, with the desired spectrum of GLP-1R-mediated signalling yet to be determined. We review the current understanding of GLP-1R function, in particular, highlighting recent contributions in the field on allosteric modulation, probe-dependence and ligand-directed signal bias and how these behaviours may influence future drug development. Topics: Allosteric Regulation; Amino Acid Sequence; Diabetes Mellitus, Type 2; Glucagon-Like Peptide 1; Glucagon-Like Peptide-1 Receptor; Humans; Incretins; Molecular Mimicry; Molecular Sequence Data; Receptors, Glucagon; Sequence Homology, Amino Acid; Signal Transduction | 2013 |
Alzheimer's disease and diabetes: new insights and unifying therapies.
Several research groups have begun to associate the Alzheimer Disease (AD) to Diabetes Mellitus (DM), obesity and cardiovascular disease. This relationship is so close that some authors have defined Alzheimer Disease as Type 3 Diabetes. Numerous studies have shown that people with type 2 diabetes have twice the incidence of sporadic AD. Insulin deficiency or insulin resistance facilitates cerebral β-amyloidogenesis in murine model of AD, accompanied by a significant elevation in APP (Amyloid Precursor Protein) and BACE1 (β-site APP Cleaving Enzime 1). Similarly, deposits of Aβ produce a loss of neuronal surface insulin receptors and directly interfere with the insulin signaling pathway. Furthermore, as it is well known, these disorders are both associated to an increased cardiovascular risk and an altered cholesterol metabolism, so we have analyzed several therapies which recently have been suggested as a remedy to treat together AD and DM. The aim of the present review is to better understand the strengths and drawbacks of these therapies. Topics: Alzheimer Disease; Amyloid Precursor Protein Secretases; Aspartic Acid Endopeptidases; Diabetes Mellitus; Diabetes Mellitus, Type 1; Diabetes Mellitus, Type 2; Female; Glucagon-Like Peptide 1; Humans; Hydroxymethylglutaryl-CoA Reductase Inhibitors; Hypercholesterolemia; Hypoglycemic Agents; Incidence; Liraglutide; Male; Metformin; Receptor, Insulin; Risk Factors; tau Proteins | 2013 |
Dysglycaemia in the critically ill - significance and management.
Hyperglycaemia frequently occurs in the critically ill, in patients with diabetes, as well as those who were previously glucose-tolerant. The terminology 'stress hyperglycaemia' reflects the pathogenesis of the latter group, which may comprise up to 40% of critically ill patients. For comparable glucose concentrations during acute illness outcomes in stress hyperglycaemia appear to be worse than those in patients with type 2 diabetes. While several studies have evaluated the optimum glycaemic range in the critically ill, their interpretation in relation to clinical recommendations is somewhat limited, at least in part because patients with stress hyperglycaemia and known diabetes were grouped together, and the optimum glycaemic range was regarded as static, rather than dynamic, phenomenon. In addition to hyperglycaemia, there is increasing evidence that hypoglycaemia and glycaemic variability influence outcomes in the critically ill adversely. These three categories of disordered glucose metabolism can be referred to as dysglycaemia. While stress hyperglycaemia is most frequently managed by administration of short-acting insulin, guided by simple algorithms, this does not treat all dysglycaemic categories; rather the use of insulin increases the risk of hypoglycaemia and may exacerbate variability. The pathogenesis of stress hyperglycaemia is complex, but hyperglucagonaemia, relative insulin deficiency and insulin resistance appear to be important. Accordingly, novel agents that have a pathophysiological rationale and treat hyperglycaemia, but do not cause hypoglycaemia and limit glycaemic variability, are appealing. The potential use of glucagon-like peptide-1 (or its agonists) and dipeptyl-peptidase-4 inhibitors is reviewed. Topics: Analysis of Variance; Biomarkers; Blood Glucose; Critical Illness; Diabetes Mellitus, Type 1; Diabetes Mellitus, Type 2; Dipeptidyl-Peptidase IV Inhibitors; Female; Glucagon; Glucagon-Like Peptide 1; Glycated Hemoglobin; Humans; Hyperglycemia; Hypoglycemia; Hypoglycemic Agents; Insulin; Insulin Resistance; Male; Risk Factors | 2013 |
Incretin-based therapies in the treatment of type 2 diabetes--more than meets the eye?
A lot of contradictory data regarding the serious side effects of incretin-based therapies are currently available, with more being prepared or published every month. Considering the widespread use of these drugs it should be considered a priority to establish both short- and long-term risks connected with incretin treatment. We performed an extensive literature search of the PubMed database looking for articles dealing with connections between incretin-based therapies and pancreatitis, pancreatic cancer, thyroid cancer and other neoplasms. Data obtained indicate that GLP-1 agonists and DPPIV inhibitors could increase the risk of pancreatitis and pancreatic cancer, possibly due to their capacity to increase ductal cell turnover, which has previously been found to be up-regulated in patients with obesity and T2DM. GLP-1 analogues exenatide and liraglutide seem to be connected with medullary thyroid carcinoma in rat models and, surprisingly, GLP-1 receptors have been found in papillary thyroid carcinoma, currently the most common neoplasm of the thyroid gland in humans. Changes in expression of DPPIV have been described in ovarian carcinoma, melanoma, endometrial adenocarcinoma, prostate cancer, non-small cell lung cancer and in certain haematological malignancies. In most cases loss of DPPIV activity is connected with a higher grading scale, more aggressive tumour behaviour and higher metastatic potential. In conclusion animal and human studies indicate that there could be a connection between incretin-based therapies and pancreatitis, pancreatic cancer, thyroid cancer and other neoplasms. Therefore whenever such therapy is started it would be wise to proceed with caution, especially if personal history of neoplasms is present. Topics: Animals; Cell Proliferation; Diabetes Mellitus, Type 2; Drug-Related Side Effects and Adverse Reactions; Gastric Inhibitory Polypeptide; Gastrointestinal Agents; Glucagon-Like Peptide 1; Humans; Incretins; Insulin; Models, Animal; Neoplasms; Outcome Assessment, Health Care; Pancreas; Pancreatic Diseases; Randomized Controlled Trials as Topic; Rats; Risk Factors | 2013 |
Secretion of glucagon-like peptide-1 in patients with type 2 diabetes mellitus: systematic review and meta-analyses of clinical studies.
We carried out a systematic review of clinical studies investigating glucagon-like peptide-1 (GLP-1) secretion in patients with type 2 diabetes and non-diabetic controls and performed meta-analyses of plasma total GLP-1 concentrations during an OGTT and/or meal test.. Random effects models for the primary meta-analysis and random effects meta-regression, subgroup and regression analyses were applied.. Random effects meta-analysis of GLP-1 responses in 22 trials during 29 different stimulation tests showed that patients with type 2 diabetes (n = 275) and controls without type 2 diabetes (n = 279) exhibited similar responses of total GLP-1 (p = NS) as evaluated from peak plasma concentrations (weighted mean difference [95% CI] 1.09 pmol/l [-2.50, 4.67]), total AUC (tAUC) (159 pmol/l × min [-270, 589]), time-corrected tAUC (tAUC min⁻¹) (0.99 pmol/l [-1.28, 3.27]), incremental AUC (iAUC) (-122 pmol/l × min [-410, 165]) and time-corrected iAUC (iAUC min⁻¹) (-0.49 pmol/l [-2.16, 1.17]). Fixed effects meta-analysis revealed higher peak plasma GLP-1 concentrations in patients with type 2 diabetes. Subgroup analysis showed increased responses after a liquid mixed meal test (peak, tAUC and tAUC min⁻¹) and after a 50 g OGTT (AUC and tAUC min⁻¹), and reduced responses after a solid mixed meal test (tAUC min⁻¹) among patients with type 2 diabetes. Meta-regression analyses showed that HbA1c and fasting plasma glucose predicted the outcomes iAUC and iAUC min⁻¹, respectively.. The present analysis suggests that patients with type 2 diabetes, in general, do not exhibit reduced GLP-1 secretion in response to an OGTT or meal test, and that deteriorating glycaemic control may be associated with reduced GLP-1 secretion. Topics: Diabetes Mellitus, Type 2; Down-Regulation; Enteroendocrine Cells; Glucagon-Like Peptide 1; Glucose Tolerance Test; Glycated Hemoglobin; Humans; Hyperglycemia; Intestinal Mucosa; Postprandial Period; Severity of Illness Index | 2013 |
[Pleiotropic effects of incretins and antidiabetic drugs with incretine mechanism].
Discovery of physiological and pharmacological characteristics of incretins (glucagon-like peptide-1 and glucose-dependent insulinotrop polypeptide), and the introduction of various products of those into the clinical practice has fundamentally changed blood glucose lowering therapy in type 2 diabetes. In addition to the antidiabetic properties more attention is paid to their favourable pleiotropic effects independent from the blood glucose lowering such as cardio-, vaso- and renoprotectiv, blood pressure lowering effects, as well as beneficial changes on blood lipid values and hepatic steatosis. These preferential changes prevail in slightly different way when incretin mimetics applied and dipeptidyl peptidase-4 inhibitors, furthermore, prolonged action of peptides metabolised by this enzyme may serve additional benefits in this latter mentioned group. The article overviews the currently known most important pleiotropic effects of incretins from the point of view of cardiorenal risk accompanying type 2 diabetes. Topics: Animals; Atherosclerosis; Blood Glucose; Blood Vessels; Cardiotonic Agents; Diabetes Mellitus, Type 2; Dipeptidyl Peptidase 4; Dipeptidyl-Peptidase IV Inhibitors; Endothelium, Vascular; Glucagon-Like Peptide 1; Humans; Hypoglycemic Agents; Incretins; Kidney; Lipids; Liver; Vasodilation | 2013 |
Frailty and safety: the example of diabetes.
Frailty is considered a syndrome of decreased reserve and resistance to stressors and is clinically expressed as muscle weakness, poor exercise tolerance, factors related to body composition, sarcopenia and disability. In addition, there is a close relationship between age-related metabolic changes and the occurrence of comorbidities that may in turn lead to frailty.Even though the downward spiral of frailty is activated more quickly in older persons with type 2 diabetes, it is reversible with appropriate interventions before reaching a high level of severity. The hazard for geriatric patients with type 2 diabetes is that frailty encompasses diverse complications already associated with or caused by diabetes. Frailty is also associated with cognitive impairment, reduced ability to perform activities of daily living and increased expression of inflammatory and coagulation markers that may contribute to the adverse microvascular effects of diabetes. Although glycaemic control remains the main targeting achievement in type 2 diabetes, especially in well-functioning older persons, this is not appropriate for those with frailty. Frail elderly people with type 2 diabetes are a specific group in need of treatment parameters for both initial and maintenance therapy with oral antidiabetic agents. Therefore, the prescription of an antidiabetic agent in such individuals must take into consideration not only the standard goal of lowering hyperglycaemic levels, but also improving the quality of life and life expectancy. The clinical management of this population is currently particularly demanding, requiring special considerations with good medical decision making. Clinical aspects complicating diabetes care in older people include cognitive decline, physical functional decline and frailty. Available oral antidiabetic drugs include insulin secretagogues (meglitinides and sulfonylureas), biguanides (metformin), α-glucosidase inhibitors, thiazolidinediones and inhibitors of glucagon-like peptide 1 (GLP-1) degrading enzyme dipeptidyl peptidase 4. In addition, we will discuss injection treatment with GLP-1 analogues. This review will underline the association between diabetes and some frailty components in old patients and how specific antidiabetic agents may play a specific role in improving outcomes. Topics: Aged; Aging; Diabetes Mellitus, Type 2; Dipeptidyl-Peptidase IV Inhibitors; Frail Elderly; Glucagon-Like Peptide 1; Glycoside Hydrolase Inhibitors; Humans; Hypoglycemic Agents; Inflammation; Insulin; Insulin Secretion; Muscle, Skeletal | 2012 |
Diabetes: glycaemic control in type 2 (drug treatments).
Diabetes mellitus is a progressive disorder of glucose metabolism. It is estimated that about 285 million people between the ages of 20 and 79 years had diabetes worldwide in 2010, or 5% of the adult population. Type 2 diabetes may occur with obesity, hypertension, and dyslipidaemia (the metabolic syndrome), which are powerful predictors of cardiovascular disease. Without adequate blood-glucose-lowering treatment, blood glucose levels may rise progressively over time in people with type 2 diabetes. Microvascular and macrovascular complications may develop.. We conducted a systematic review and aimed to answer the following clinical question: What are the effects of blood-glucose-lowering medications in adults with type 2 diabetes? We searched: Medline, Embase, The Cochrane Library, and other important databases up to February 2010 (Clinical Evidence reviews are updated periodically, please check our website for the most up-to-date version of this review). We included harms alerts from relevant organisations such as the US Food and Drug Administration (FDA) and the UK Medicines and Healthcare products Regulatory Agency (MHRA).. We found 194 systematic reviews, RCTs, or observational studies that met our inclusion criteria. We performed a GRADE evaluation of the quality of evidence for interventions.. In this systematic review we present information relating to the effectiveness and safety of the following interventions: alpha-glucosidase inhibitors (AGIs), combination treatment (single, double, and triple), dipeptidyl peptidase-4 (DPP-4) inhibitors, glucagon-like peptide-1 (GLP-1) analogues, insulins (including conventional [human] and analogue, different regimens, different length of action), meglitinides, metformin, sulphonylureas, and thiazolidinediones. Topics: Blood Glucose; Diabetes Mellitus, Type 2; Glucagon-Like Peptide 1; Humans; Hypoglycemic Agents; Metformin | 2012 |
GPR119 agonists 2009-2011.
The increasing incidence of Type II diabetes mellitus worldwide continues to attract the attention and resources of the pharmaceutical industry in the pursuit of more effective therapies for blood glucose control. New approaches that compare favorably with classical medicaments while avoiding hypoglycemic episodes or waning effectiveness are paramount. Recent advances toward this end have been realized based on the biology of the glucagon like peptide-1 receptor (GLP1R). This β-cell-expressed GPCR has the ability to promote insulin release in a glucose-dependent fashion, and has been shown to elicit improved glycemic control and preservation of β-cell mass. Direct activation of GLP1R utilizing peptide mimetics has been achieved; however, attempts to access the biology of this receptor via small-molecule approaches have thus far been elusive. In this context, GPR119 has emerged as a tractable new alternative to GLP1R. GPR119 is another GPCR expressed on the β-cell, which, like GLP1R, signals in a glucose-dependent manner. Moreover, GPR119-mediated increases in GLP-1 and other incretins upon activation in the intestine further increase the insulinotropic activity of the β-cell. The early success in identifying small-molecule agonists of the GPR119 has prompted a rapid increase in the number of patent applications filed in the last few years. In this review we provide a comprehensive summary of all patent activity in this field that has appeared within the 2009-2011 timeframe. Topics: Animals; Blood Glucose; Diabetes Mellitus, Type 2; Drug Design; Glucagon-Like Peptide 1; Glucagon-Like Peptide-1 Receptor; Humans; Hypoglycemic Agents; Insulin; Insulin-Secreting Cells; Patents as Topic; Receptors, G-Protein-Coupled; Receptors, Glucagon | 2012 |
Potential New Approaches to Modifying Intestinal GLP-1 Secretion in Patients with Type 2 Diabetes Mellitus : Focus on Bile Acid Sequestrants.
Type 2 diabetes mellitus is associated with a progressive decline in insulinproducing pancreatic β-cells, an increase in hepatic glucose production, and a decrease in insulin sensitivity. The incretin hormones glucose-dependent insulinotropic polypeptide (GIP) and glucagon-like peptide-1 (GLP-1) stimulate glucose-induced insulin secretion; however, in patients with type 2 diabetes, the incretin system is impaired by loss of the insulinotropic effects of GIP as well as a possible reduction in secretion of GLP-1. Agents that modify GLP-1 secretion may have a role in the management of type 2 diabetes. The currently available incretin-based therapies, GLP-1 receptor agonists (incretin mimetics) and dipeptidyl peptidase-4 (DPP-4) inhibitors (CD26 antigen inhibitors) [incretin enhancers], are safe and effective in the treatment of type 2 diabetes. However, they may be unable to halt the progression of type 2 diabetes, perhaps because they do not increase secretion of endogenous GLP-1. Therapies that directly target intestinal L cells to stimulate secretion of endogenous GLP-1 could possibly prove more effective than treatment with GLP-1 receptor agonists and DPP-4 inhibitors. Potential new approaches to modifying intestinal GLP-1 secretion in patients with type 2 diabetes include G-protein-coupled receptor (GPCR) agonists, α-glucosidase inhibitors, peroxisome proliferator-activated receptor (PPAR) agonists, metformin, bile acid mimetics and bile acid sequestrants. Both the GPCR agonist AR231453 and the novel bile acid mimetic INT-777 have been shown to stimulate GLP-1 release, leading to increased insulin secretion and improved glucose tolerance in mice. Similarly, a study in insulin-resistant rats demonstrated that the bile acid sequestrant colesevelam increased GLP-1 secretion and improved glucose levels and insulin resistance. In addition, the bile acid sequestrant colestimide (colestilan) has been shown to increase GLP-1 secretion and decrease glucose levels in patients with type 2 diabetes; these results suggest that the glucose-lowering effects of bile acid sequestrants may be partly due to their ability to increase endogenous GLP-1 levels. Evidence suggests that GPCR agonists, α-glucosidase inhibitors, PPAR agonists, metformin, bile acid mimetics and bile acid sequestrants may represent a new approach to management of type 2 diabetes via modification of endogenous GLP-1 secretion. Topics: Animals; Bile Acids and Salts; Colesevelam Hydrochloride; Diabetes Mellitus, Type 2; Glucagon-Like Peptide 1; Glycoside Hydrolase Inhibitors; Humans; Hypoglycemic Agents; Incretins; Insulin-Secreting Cells; Peroxisome Proliferator-Activated Receptors | 2012 |
Incretin-based therapies.
Incretin-based therapies have established a foothold in the diabetes armamentarium through the introduction of oral dipeptidyl peptidase-4 inhibitors and the injectable class, the glucagon-like peptide-1 receptor agonists. In 2009, the American Diabetes Association and European Association for the Study of Diabetes authored a revised consensus algorithm for the initiation and adjustment of therapy in Type 2 diabetes (T2D). The revised algorithm accounts for the entry of incretin-based therapies into common clinical practice, especially where control of body weight and hypoglycemia are concerns. The gut-borne incretin hormones have powerful effects on glucose homeostasis, particularly in the postprandial period, when approximately two-thirds of the β-cell response to a given meal is due to the incretin effect. There is also evidence that the incretin effect is attenuated in patients with T2D, whereby the β-cell becomes less responsive to incretin signals. The foundation of incretin-based therapies is to target this previously unrecognized feature of diabetes pathophysiology, resulting in sustained improvements in glycemic control and improved body weight control. In addition, emerging evidence suggests that incretin-based therapies may have a positive impact on inflammation, cardiovascular and hepatic health, sleep, and the central nervous system. In the present article, we discuss the attributes of current and near-future incretin-based therapies. Topics: Blood Glucose; Diabetes Mellitus, Type 2; Dipeptidyl-Peptidase IV Inhibitors; Glucagon-Like Peptide 1; Glucagon-Like Peptide-1 Receptor; Humans; Incretins; Receptors, Glucagon | 2012 |
Dipeptidyl peptidase-4 inhibitors and preservation of pancreatic islet-cell function: a critical appraisal of the evidence.
Type 2 diabetes mellitus (T2DM) develops as a consequence of progressive β-cell dysfunction in the presence of insulin resistance. None of the currently-available T2DM therapies is able to change the course of the disease by halting the relentless decline in pancreatic islet cell function. Recently, dipeptidyl peptidase (DPP)-4 inhibitors, or incretin enhancers, have been introduced in the treatment of T2DM. This class of glucose-lowering agents enhances endogenous glucagon-like peptide 1 (GLP-1) and glucose-dependent insulinotropic polypeptide (GIP) levels by blocking the incretin-degrading enzyme DPP-4. DPP-4 inhibitors may restore the deranged islet-cell balance in T2DM, by stimulating meal-related insulin secretion and by decreasing postprandial glucagon levels. Moreover, in rodent studies, DPP-4 inhibitors demonstrated beneficial effects on (functional) β-cell mass and pancreatic insulin content. Studies in humans with T2DM have indicated improvement of islet-cell function, both in the fasted state and under postprandial conditions and these beneficial effects were sustained in studies with a duration up to 2 years. However, there is at present no evidence in humans to suggest that DPP-4 inhibitors have durable effects on β-cell function after cessation of therapy. Long-term, large-sized trials using an active blood glucose lowering comparator followed by a sufficiently long washout period after discontinuation of the study drug are needed to assess whether DPP-4 inhibitors may durably preserve pancreatic islet-cell function in patients with T2DM. Topics: Animals; Blood Glucose; Diabetes Mellitus, Type 2; Dipeptidyl Peptidase 4; Dipeptidyl-Peptidase IV Inhibitors; Disease Progression; Dogs; Gastric Inhibitory Polypeptide; Glucagon-Like Peptide 1; Humans; Islets of Langerhans; Rats | 2012 |
Using albumin to improve the therapeutic properties of diabetes treatments.
Achieving tight glycaemic control remains an unmet need for many patients with type 2 diabetes, despite improved treatments. To meet glycaemic targets, attempts have been made to improve existing drugs and to develop new classes of drugs. Recent advances include insulin analogues that more closely mimic physiologic insulin levels, and incretin-based therapies, which capitalize on the glucoregulatory properties of native glucagon-like peptide-1 (GLP-1). Although promising, these agents are associated with limitations, including hypoglycaemia with insulin, gastrointestinal adverse events with GLP-1 receptor agonists and frequent dosing with both classes. Albumin is an abundant natural drug carrier that has been used to improve the half-life, tolerability and efficacy of a number of bioactive agents. Here, we review the physiologic roles of albumin and how albumin technologies are being used to prolong duration of action of therapies for diabetes, including insulin and incretin-based therapies. Topics: Adult; Aged; Albumins; Antioxidants; Blood Glucose; Diabetes Mellitus, Type 2; Drug Carriers; Female; Glucagon-Like Peptide 1; Humans; Incretins; Insulin; Lipid Metabolism; Male; Middle Aged; Young Adult | 2012 |
Achieving a clinically relevant composite outcome of an HbA1c of <7% without weight gain or hypoglycaemia in type 2 diabetes: a meta-analysis of the liraglutide clinical trial programme.
Effective type 2 diabetes management requires a multifactorial approach extending beyond glycaemic control. Clinical practice guidelines suggest targets for HbA1c, blood pressure and lipids, and emphasize weight reduction and avoiding hypoglycaemia. The phase 3 clinical trial programme for liraglutide, a human glucagon-like peptide 1 analogue, showed significant improvements in HbA1c and weight with a low risk of hypoglycaemia compared to other diabetes therapies. In this context, we performed a meta-analysis of data from these trials evaluating the proportion of patients achieving a clinically relevant composite measure of diabetes control consisting of an HbA1c <7% without weight gain or hypoglycaemia.. A prespecified meta-analysis was performed on 26-week patient-level data from seven trials (N = 4625) evaluating liraglutide with commonly used therapies for type 2 diabetes: glimepiride, rosiglitazone, glargine, exenatide, sitagliptin or placebo, adjusting for baseline HbA1c and weight, for a composite outcome of HbA1c <7.0%, no weight gain and no hypoglycaemic events.. At 26 weeks, 40% of the liraglutide 1.8 mg group, 32% of the liraglutide 1.2 mg group and 6-25% of comparators (6% rosiglitazone, 8% glimepiride, 15% glargine, 25% exenatide, 11% sitagliptin, 8% placebo) achieved this composite outcome. Odds ratios favoured liraglutide 1.8 mg by 2.0- to 10.5-fold over comparators.. As assessed by the composite outcome of HbA1c <7%, no hypoglycaemia and no weight gain, liraglutide was clearly superior to the other commonly used therapies. However, the long-term clinical impact of this observation remains to be shown. Topics: Clinical Trials, Phase III as Topic; Diabetes Mellitus, Type 2; Female; Glucagon-Like Peptide 1; Glycated Hemoglobin; Humans; Hypoglycemia; Hypoglycemic Agents; Liraglutide; Male; Middle Aged; Weight Gain | 2012 |
The structure and function of the glucagon-like peptide-1 receptor and its ligands.
Glucagon-like peptide-1(7-36)amide (GLP-1) is a 30-residue peptide hormone released from intestinal L cells following nutrient consumption. It potentiates the glucose-induced secretion of insulin from pancreatic beta cells, increases insulin expression, inhibits beta-cell apoptosis, promotes beta-cell neogenesis, reduces glucagon secretion, delays gastric emptying, promotes satiety and increases peripheral glucose disposal. These multiple effects have generated a great deal of interest in the discovery of long-lasting agonists of the GLP-1 receptor (GLP-1R) in order to treat type 2 diabetes. This review article summarizes the literature regarding the discovery of GLP-1 and its physiological functions. The structure, function and sequence-activity relationships of the hormone and its natural analogue exendin-4 (Ex4) are reviewed in detail. The current knowledge of the structure of GLP-1R, a Family B GPCR, is summarized and discussed, before its known interactions with the principle peptide ligands are described and summarized. Finally, progress in discovering non-peptide ligands of GLP-1R is reviewed. GLP-1 is clearly an important hormone linking nutrient consumption with blood sugar control, and therefore knowledge of its structure, function and mechanism of action is of great importance. Topics: Animals; Diabetes Mellitus, Type 2; Glucagon-Like Peptide 1; Glucagon-Like Peptide-1 Receptor; Glucose; Humans; Hypoglycemic Agents; Insulin; Ligands; Peptides; Protein Conformation; Receptors, Glucagon | 2012 |
Current evidence for a role of GLP-1 in Roux-en-Y gastric bypass-induced remission of type 2 diabetes.
Weight-reducing surgical procedures such as Roux-en-Y gastric bypass (RYGB) have proven efficient as means of decreasing excess body weight. Furthermore, some studies report that up to 80% of patients with type 2 diabetes mellitus (T2DM) undergoing RYGB experience complete remission of their T2DM. Interestingly, the majority of remissions occur almost immediately following the operation and long before significant weight loss has taken place. Following RYGB, dramatic increases in postprandial plasma concentrations of the incretin hormone glucagon-like peptide-1 (GLP-1) have been recorded, and the known antidiabetic effects of GLP-1 are thought to be key mediators in RYGB-induced remission of T2DM. However, the published studies on the impact of RYGB on GLP-1 secretion are few, small and often not controlled properly. Furthermore, mechanistic studies delineating the role of endogenous GLP-1 secretion in RYGB-induced remission of T2DM are lacking. This article critically evaluates the current evidence for a role of GLP-1 in RYGB-induced remission of T2DM. Topics: Blood Glucose; Diabetes Mellitus, Type 2; Evidence-Based Medicine; Female; Gastric Bypass; Glucagon-Like Peptide 1; Homeostasis; Humans; Male; Obesity; Postoperative Period; Remission Induction; Treatment Outcome; Weight Loss | 2012 |
Proportion of patients at HbA1c target <7% with eight classes of antidiabetic drugs in type 2 diabetes: systematic review of 218 randomized controlled trials with 78 945 patients.
We assessed the efficacy of eight classes of diabetes medications used in current clinical practice [metformin, sulphonylureas, α-glucosidase inhibitors, thiazolidinediones, glinides, dipeptidyl peptidase-4 inhibitors, glucagon-like peptide-1 (GLP-1) analogues and insulin analogues] to reach the HbA1c target <7% in type 2 diabetes.. MEDLINE, EMBASE and the Cochrane CENTRAL were searched from inception through April 2011 for randomized controlled trials (RCTs) involving antidiabetic drugs. RCTs had to report the effect of any diabetes medication on the HbA1c levels, to include at least 30 subjects in every arm of the study, and to report the effect of therapy after a minimum of 12 weeks. Data were summarized across studies using random-effects meta-regression.. A total of 218 RCTs (339 arms and 77 950 patients) met the inclusion criteria. The proportion of patients who achieved the HbA1c goal ranged from 25.9% (95% CI 18.5-34.9) with α-glucosidase inhibitors to 63.2% (54.1-71.5) with the long-acting GLP-1 analogue. There was a progressive decrease of the proportion of patients at target for each 0.5% increase in baseline HbA1c, ranging from 57.8% for HbA1c ≤7.5% to 20.8% for HbA1c ≥10% (p for trend <0.0001), with some difference between insulin and non-insulin drugs: for insulin, the proportion of patients at goal reached a plateau for basal HbA1c value >9.0% with no further decrease, whereas for non-insulin drugs the relationship was continuous without any evidence of plateau.. There is a considerable variability with regard to attainment of HbA1c goal of <7% among the different classes of diabetes medications; baseline HbA1c is an important determinant of observed efficacy. Topics: Adolescent; Adult; Diabetes Mellitus, Type 2; Dipeptidyl-Peptidase IV Inhibitors; Female; Glucagon-Like Peptide 1; Glycated Hemoglobin; Humans; Hypoglycemic Agents; Insulin; Male; Middle Aged; Randomized Controlled Trials as Topic; Sulfonylurea Compounds; Thiazolidinediones; Young Adult | 2012 |
Potential new approaches to modifying intestinal GLP-1 secretion in patients with type 2 diabetes mellitus: focus on bile acid sequestrants.
Type 2 diabetes mellitus is associated with a progressive decline in insulin-producing pancreatic β-cells, an increase in hepatic glucose production, and a decrease in insulin sensitivity. The incretin hormones glucose-dependent insulinotropic polypeptide (GIP) and glucagon-like peptide-1 (GLP-1) stimulate glucose-induced insulin secretion; however, in patients with type 2 diabetes, the incretin system is impaired by loss of the insulinotropic effects of GIP as well as a possible reduction in secretion of GLP-1. Agents that modify GLP-1 secretion may have a role in the management of type 2 diabetes. The currently available incretin-based therapies, GLP-1 receptor agonists (incretin mimetics) and dipeptidyl peptidase-4 (DPP-4) inhibitors (CD26 antigen inhibitors) [incretin enhancers], are safe and effective in the treatment of type 2 diabetes. However, they may be unable to halt the progression of type 2 diabetes, perhaps because they do not increase secretion of endogenous GLP-1. Therapies that directly target intestinal L cells to stimulate secretion of endogenous GLP-1 could possibly prove more effective than treatment with GLP-1 receptor agonists and DPP-4 inhibitors. Potential new approaches to modifying intestinal GLP-1 secretion in patients with type 2 diabetes include G-protein-coupled receptor (GPCR) agonists, α-glucosidase inhibitors, peroxisome proliferator-activated receptor (PPAR) agonists, metformin, bile acid mimetics and bile acid sequestrants. Both the GPCR agonist AR231453 and the novel bile acid mimetic INT-777 have been shown to stimulate GLP-1 release, leading to increased insulin secretion and improved glucose tolerance in mice. Similarly, a study in insulin-resistant rats demonstrated that the bile acid sequestrant colesevelam increased GLP-1 secretion and improved glucose levels and insulin resistance. In addition, the bile acid sequestrant colestimide (colestilan) has been shown to increase GLP-1 secretion and decrease glucose levels in patients with type 2 diabetes; these results suggest that the glucose-lowering effects of bile acid sequestrants may be partly due to their ability to increase endogenous GLP-1 levels. Evidence suggests that GPCR agonists, α-glucosidase inhibitors, PPAR agonists, metformin, bile acid mimetics and bile acid sequestrants may represent a new approach to management of type 2 diabetes via modification of endogenous GLP-1 secretion. Topics: Bile; Diabetes Mellitus, Type 2; Glucagon-Like Peptide 1; Humans; Incretins; Intestinal Mucosa; Intestines | 2012 |
The role of GLP-1 mimetics and basal insulin analogues in type 2 diabetes mellitus: guidance from studies of liraglutide.
In people with type 2 diabetes mellitus (T2DM), the incretin effect is reduced, but the recent advent of dipeptidyl peptidase-4 inhibitors and glucagon-like peptide (GLP)-1 agonists/analogues has enabled restoration of at least some of the function of the incretin system, with accompanying improvements in glycaemic control. Two GLP-1 receptor agonists/analogues are currently approved for the treatment of T2DM-exenatide (Byetta®, Eli Lilly & Co., Indianapolis, IN, US) and liraglutide (Victoza®, Novo Nordisk, Bagsvaerd, Denmark); a once-weekly formulation of exenatide (Bydureon®, Eli Lilly & Co.) has also been approved by the European Medicines Agency. The National Institute for Health and Clinical Excellence (NICE) has recently published guidance on the use of liraglutide in T2DM, based on evidence from the Liraglutide Effect and Action in Diabetes (LEAD) Phase III trial programme, which compared liraglutide with existing glucose-lowering therapies, such as exenatide and insulin glargine. The LEAD programme reported HbA1c reductions from 0.8 to 1.5% with liraglutide (1.2 and 1.8 mg), accompanied by low rates of hypoglycaemia and some weight loss; side effects were primarily gastrointestinal in nature (e.g. nausea and diarrhoea). Based on the findings of the LEAD studies and the NICE recommendation, liraglutide now represents an important therapy widely available in the UK for certain patient groups, including those with a body mass index (BMI) ≥35.0 kg/m(2) , and patients with a BMI <35 kg/m(2) who are considered unsuitable for insulin and are failing to meet targets for glycaemic control with oral agents. NICE guidelines still suggest that most patients without considerable obesity (BMI <35 kg/m(2) ) are probably best managed using insulin therapy. Evidence also suggests a future role for GLP-1 mimetics in combination with basal insulin. Topics: Algorithms; Diabetes Mellitus, Type 2; Drug Administration Schedule; Evidence-Based Medicine; Exenatide; Female; Glucagon-Like Peptide 1; Glycated Hemoglobin; Humans; Hypoglycemic Agents; Insulin Detemir; Insulin Glargine; Insulin, Long-Acting; Liraglutide; Male; Peptides; Randomized Controlled Trials as Topic; United Kingdom; Venoms; Weight Loss | 2012 |
Evolving treatment strategies for the management of type 2 diabetes.
It is well known that improved metabolic control significantly reduces both micro- and macrovascular complications in diabetes. As it relates to specific treatment of type 2 diabetes mellitus, clinicians have traditionally initiated lifestyle intervention and progressed therapy using various drug treatments first as monotherapy and then as combination therapy throughout the course of the disease. This "stepwise" strategy has not always achieved the desired outcome of normal glycemic control; consequently, several clinical problems, such as hypoglycemia, weight gain and postprandial hyperglycemia, persist. However, new therapies that improve glycemic control and have favorable effects to address the unmet clinical problems have recently been developed or are still in development. These therapies include 2 classes of incretin-directed therapy, the dipeptidyl peptidase-4 inhibitors and the glucagon-like peptide-1 agonists, which help restore physiologic levels and activity of the incretin glucagon-like peptide-1. Also in development are additional therapies that have effects on the kidney to promote glucose excretion. These therapies are proposed to treat the key metabolic abnormalities associated with type 2 diabetes mellitus and minimize the side effects noted with conventional therapies. Topics: Diabetes Mellitus, Type 2; Dipeptidyl-Peptidase IV Inhibitors; Glucagon-Like Peptide 1; Humans; Hypoglycemic Agents; Kidney | 2012 |
Clinical efficacy and safety of once-weekly glucagon-like peptide-1 agonists in development for treatment of type 2 diabetes mellitus in adults.
To review pharmacologic, pharmacokinetic, efficacy, and safety data of once-weekly glucagon-like peptide-1 (GLP-1) agonists exenatide long-acting release (LAR), albiglutide, and taspoglutide in treatment of type 2 diabetes mellitus (T2DM).. A MEDLINE search (1966-August 2011) was conducted using the following key words: type 2 diabetes mellitus, glucagon-like peptide-1 agonists once weekly, glucagon-like peptide-1 agonists, exenatide LAR, albiglutide, and taspoglutide.. All articles published in English identified from the data sources were evaluated, prioritizing randomized controlled trials with human data. The references of published articles identified were examined for additional studies appropriate for the review.. Native GLP-1 increases glucose-dependent insulin secretion, decreases glucagon secretion, and slows gastric emptying in healthy individuals, but these effects may be blunted in patients with T2DM. Because native GLP-1 is rapidly degraded by dipeptidyl peptidase-IV, it is not a practical treatment option. Currently, 2 GLP-1 receptor agonists have been approved by the Food and Drug Administration: exenatide twice daily and liraglutide once daily. Several additional GLP-1 agonists, including exenatide LAR, albiglutide, and taspoglutide, are in various stages of clinical trials and have been modified to increase their half-lives. These agents have shown significant improvements in hemoglobin A(1c), fasting plasma glucose, and postprandial plasma glucose, as well as improvements in body weight, blood pressure, and lipid parameters. These agents allow for less-frequent dosing schedules, improved glycemic control throughout the day, and improved treatment satisfaction compared to some available agents. GLP-1 agonists have been well tolerated, with the most common adverse effects being gastrointestinal related, which occurred early in therapy but typically resolved after 4-8 weeks. The incidence of hypoglycemia was infrequent and mild during therapy.. Once-weekly GLP-1 agonists provide similar glycemic control with weight reduction, as well as overall higher treatment satisfaction for patients because of their ease of use and need for less-frequent dosing compared to some available agents. Topics: Adult; Delayed-Action Preparations; Diabetes Mellitus, Type 2; Drug Administration Schedule; Exenatide; Glucagon-Like Peptide 1; Humans; Hypoglycemic Agents; Peptides; Randomized Controlled Trials as Topic; Treatment Outcome; Venoms | 2012 |
GLP-1 based therapies: differential effects on fasting and postprandial glucose.
Glucagon-like peptide-1 (GLP-1), a gut-derived hormone secreted in response to nutrients, has several glucose and weight regulating actions including enhancement of glucose-stimulated insulin secretion, suppression of glucagon secretion, slowing of gastric emptying and reduction in food intake. Because of these multiple effects, the GLP-1 receptor system has become an attractive target for type 2 diabetes therapies. However, GLP-1 has significant limitations as a therapeutic due to its rapid degradation (plasma half-life of 1-2 min) by dipeptidyl peptidase-4 (DPP-4). Two main classes of GLP-1-mediated therapies are now in use: DPP-4 inhibitors that reduce the degradation of GLP-1 and DPP-4-resistant GLP-1 receptor (GLP-1R) agonists. The GLP-1R agonists can be further divided into short- and long-acting formulations which have differential effects on their mechanisms of action, ultimately resulting in differential effects on their fasting and postprandial glucose lowering potential. This review summarizes the similarities and differences among DPP-4 inhibitors, short-acting GLP-1R agonists and long-acting GLP-1R agonists. We propose that these different GLP-1-mediated therapies are all necessary tools for the treatment of type 2 diabetes and that the choice of which one to use should depend on the specific needs of the patient. This is analogous to the current use of modern insulins, as short-, intermediate- and long-acting versions are all used to optimize the 24-h plasma glucose profile as needed. Given that GLP-1-mediated therapies have advantages over insulins in terms of hypoglycaemic risk and weight gain, optimized use of these compounds could represent a significant paradigm shift for the treatment of type 2 diabetes. Topics: Blood Glucose; Body Weight; Diabetes Mellitus, Type 2; Dose-Response Relationship, Drug; Exenatide; Fasting; Female; Glucagon-Like Peptide 1; Half-Life; Humans; Hypoglycemic Agents; Liraglutide; Male; Peptides; Postprandial Period; Treatment Outcome; Venoms | 2012 |
Effects of glucagon-like peptide-1 receptor agonists on weight loss: systematic review and meta-analyses of randomised controlled trials.
To determine whether treatment with agonists of glucagon-like peptide-1 receptor (GLP-1R) result in weight loss in overweight or obese patients with or without type 2 diabetes mellitus.. Systematic review with meta-analyses.. Electronic searches (Cochrane Library, Medline, Embase, and Web of Science) and manual searches (up to May 2011). Review methods Randomised controlled trials of adult participants with a body mass index of 25 or higher; with or without type 2 diabetes mellitus; and who received exenatide twice daily, exenatide once weekly, or liraglutide once daily at clinically relevant doses for at least 20 weeks. Control interventions assessed were placebo, oral antidiabetic drugs, or insulin.. Three authors independently extracted data. We used random effects models for the primary meta-analyses. We also did subgroup, sensitivity, regression, and sequential analyses to evaluate sources of intertrial heterogeneity, bias, and the robustness of results after adjusting for multiple testing and random errors.. 25 trials were included in the analysis. GLP-1R agonist groups achieved a greater weight loss than control groups (weighted mean difference -2.9 kg, 95% confidence interval -3.6 to -2.2; 21 trials, 6411 participants). We found evidence of intertrial heterogeneity, but no evidence of bias or small study effects in regression analyses. The results were confirmed in sequential analyses. We recorded weight loss in the GLP-1R agonist groups for patients without diabetes (-3.2 kg, -4.3 to -2.1; three trials) as well as patients with diabetes (-2.8 kg, -3.4 to -2.3; 18 trials). In the overall analysis, GLP-1R agonists had beneficial effects on systolic and diastolic blood pressure, plasma concentrations of cholesterol, and glycaemic control, but did not have a significant effect on plasma concentrations of liver enzymes. GLP-1R agonists were associated with nausea, diarrhoea, and vomiting, but not with hypoglycaemia.. The present review provides evidence that treatment with GLP-1R agonists leads to weight loss in overweight or obese patients with or without type 2 diabetes mellitus. Topics: Anti-Obesity Agents; Diabetes Mellitus, Type 2; Drug Administration Schedule; Exenatide; Glucagon-Like Peptide 1; Glucagon-Like Peptide-1 Receptor; Humans; Hypoglycemic Agents; Liraglutide; Obesity; Overweight; Peptides; Receptors, Glucagon; Treatment Outcome; Venoms; Weight Loss | 2012 |
An overview of the pharmacokinetics, efficacy and safety of liraglutide.
Incretin-based therapies, including glucagon-like peptide 1 (GLP-1) receptor agonists, are the latest addition to the range of available medications for the management of patients with type 2 diabetes. The GLP-1 analog liraglutide has been approved for use in Europe and the US for over a year and has undergone evaluation in several pharmacokinetic/pharmacodynamics studies and in an extensive phase 3 clinical program. The aim of this review is to assess the pharmacokinetics, efficacy and safety of the phase 3 data.. Data are presented from the pharmacokinetics/pharmacodynamics studies of liraglutide and from nine published phase 3 studies, including the six Liraglutide Effect and Action in Diabetes (LEAD) studies.. Liraglutide is effective at improving indices of glycemic control, and has a good tolerability and safety profile. Beneficial effects on weight (mean reduction of 1-3.4 kg) and blood pressure (systolic blood pressure decreased by 2.1-6.7 mmHg) are also observed.. Liraglutide is an effective and well tolerated option for the treatment of type 2 diabetes. Topics: Blood Glucose; Blood Pressure; Body Weight; Clinical Trials, Phase III as Topic; Diabetes Mellitus, Type 2; Female; Glucagon-Like Peptide 1; Humans; Hypoglycemic Agents; Incretins; Injections, Subcutaneous; Insulin-Secreting Cells; Liraglutide; Male; Randomized Controlled Trials as Topic; Receptors, Glucagon; Treatment Outcome | 2012 |
Improving glucagon-like peptide-1 dynamics in patients with type 2 diabetes mellitus.
The increased number of cases of type 2 diabetes mellitus (both diagnosed and undiagnosed) parallels the current epidemic of obesity in the United States. Despite receiving treatment, many patients do not achieve established therapeutic goals. Type 2 diabetes mellitus is a progressive disease characterized by multiple abnormalities that extend beyond β-cell dysfunction and insulin resistance. Incretin-based agents, including glucagon-like peptide-1 (GLP-1) receptor agonists and dipeptidyl peptidase-4 (DPP-4) inhibitors, have become important options in the therapeutic paradigm for patients with type 2 diabetes mellitus. The author reviews physiologic mechanisms of the incretin system and discusses the practical application of GLP-1 receptor agonists and DPP-4 inhibitors in improving GLP-1 dynamics in patients with type 2 diabetes mellitus. Topics: Blood Glucose; Diabetes Mellitus, Type 2; Glucagon-Like Peptide 1; Humans; Hypoglycemic Agents; Treatment Outcome | 2012 |
Vascular protective effects of diabetes medications that mimic or increase glucagon-like peptide-1 activity.
The incidence of type 2 diabetes (T2DM) is increasing rapidly worldwide and is a strong risk factor for cardiovascular disease (CVD) events. Although hyperglycemia is associated with increased CVD, intensive glycemic control with current diabetes medications has failed in recent large clinical trials to reduce macrovascular disease, demonstrating that intensive glucose control alone is insufficient to reduce major CVD events. A new approach to lowering glucose takes advantage of the incretin system and medications that raise or mimic glucagon-like peptide-1 (GLP-1). These agents not only improve glycemic control by mechanisms that minimize hypoglycemia, but also improve lipoprotein profiles, blood pressure control and weight loss. There is also increasing evidence that at least pharmacologic concentrations of GLP-1 or GLP-1 mimetics may improve endothelial function and have direct vascular-protective effects. Importantly, these benefits transpired even before the improvements in weight and overall glucose control occurred. It remains to be seen whether the chronic effects of GLP-1 activity on glucose, CVD risk factors and vascular function will lead to lasting beneficial effects on CVD risk. If preliminary findings on the vasculoprotective effects of GLP-1 agents are validated and confirmed in longitudinal clinical trials, this class of drugs may represent a paradigm shift in the treatment of vascular disease in both patients with diabetes and in non-diabetic individuals at high risk for CVD. Recent patents regarding GLP-1 agents are discussed in this review article. Topics: Animals; Biomimetic Materials; Cardiovascular Diseases; Clinical Trials as Topic; Diabetes Mellitus, Type 2; Drug Evaluation, Preclinical; Glucagon-Like Peptide 1; Humans; Longitudinal Studies; Randomized Controlled Trials as Topic | 2012 |
Dipeptidylpeptidase-4 (DPP-4) inhibitors are favourable to glucagon-like peptide-1 (GLP-1) receptor agonists: yes.
The pharmacological treatment of type 2 diabetes (T2DM) is becoming increasingly complex, especially since the availability of incretin-based therapies. Compared with other glucose-lowering strategies, these novel drugs offer some advantages such as an absence of weight gain and a negligible risk of hypoglycaemia and, possibly, better cardiovascular and β-cell protection. The physician has now multiple choices to manage his/her patient after secondary failure of metformin, and the question whether it is preferable to add an oral dipeptidylpeptidase-4 (DPP-4) inhibitor (gliptin) or an injectable glucagon-like peptide-1 (GLP-1) receptor agonist will emerge. Obviously, DPP-4 inhibitors offer several advantages compared with GLP-1 receptor agonists, especially regarding easiness of use, tolerance profile and cost. However, because they can only increase endogenous GLP-1 concentrations to physiological (rather than pharmacological) levels, they are less potent to improve glucose control, promote weight reduction ("weight neutrality") and reduce blood pressure compared to GLP-1 receptor agonists. Of note, none of the two classes have proven long-term safety and positive impact on diabetic complications yet. The role of DPP-4 inhibitors and GLP-1 receptor agonists in the therapeutic armamentarium of T2DM is rapidly evolving, but their respective potential strengths and weaknesses should be better defined in long-term head-to-head comparative controlled trials. Instead of trying to answer the question whether DPP-4 inhibitors are favourable to GLP-1 receptor agonists (or vice versa), it is probably more clinically relevant to look at which T2DM patient will benefit more from one or the other therapy considering all his/her individual clinical characteristics ("personalized medicine"). Topics: Blood Glucose; Diabetes Mellitus, Type 2; Dipeptidyl-Peptidase IV Inhibitors; Glucagon-Like Peptide 1; Glucagon-Like Peptide-1 Receptor; Humans; Receptors, Glucagon; Treatment Outcome | 2012 |
The effect of glucagon-like peptide 1 on cardiovascular risk.
Glucagon-like peptide 1 (GLP-1) is an incretin hormone responsible for amplification of insulin secretion when nutrients are given orally, as opposed to intravenously, and it retains its insulinotropic activity in patients with type 2 diabetes mellitus. GLP-1-based therapies, such as GLP-1 receptor agonists and inhibitors of dipeptidyl peptidase 4, an enzyme that degrades endogenous GLP-1, have established effectiveness in lowering glucose levels and are routinely used to treat patients with type 2 diabetes. These agents regulate glucose metabolism through multiple mechanisms and have several effects on cardiovascular parameters. These effects, possibly independent of the glucose-lowering activity, include changes in blood pressure, endothelial function, body weight, cardiac metabolism, lipid metabolism, left ventricular function, atherosclerosis, and the response to ischemia-reperfusion injury. Thus, GLP-1-based therapies could potentially target both diabetes and cardiovascular disease. This Review highlights the mechanisms targeted by GLP-1-based therapies, and emphasizes current developments in incretin research that are relevant to cardiovascular risk and disease, as well as treatment with GLP-1 receptor agonists. Topics: Animals; Blood Glucose; Cardiovascular Diseases; Diabetes Mellitus, Type 2; Evidence-Based Medicine; Glucagon-Like Peptide 1; Glucagon-Like Peptide-1 Receptor; Humans; Hypoglycemic Agents; Receptors, Glucagon; Risk Assessment; Risk Factors; Treatment Outcome | 2012 |
A continued saga of Boc5, the first non-peptidic glucagon-like peptide-1 receptor agonist with in vivo activities.
Glucagon-like peptide-1 (GLP-1)-based therapy presents a promising option for treating type 2 diabetes. However, there are several limitations relative to the peptidic GLP-1 mimetics currently on the market or under development. This concern has led to a continued interest in the search for non-peptidic agonists for GLP-1 receptor (GLP-1R). Here, we briefly review the discovery, characterization and current status of a novel class of cyclobutane-derivative-based non-peptidic agonists for GLP-1R, including Boc5 and its newly discovered analogue WB4-24. Although the oral bioavailability of such compounds still poses great challenges, the progress made so far encourages us to identify a truly 'druggable' small molecule agonist for GLP-1R. Topics: Animals; Cyclobutanes; Diabetes Mellitus, Type 2; Glucagon-Like Peptide 1; Glucagon-Like Peptide-1 Receptor; Humans; Receptors, Glucagon | 2012 |
Gut feelings about diabetes.
Studies of patients going into diabetes remission after gastric bypass surgery have demonstrated the important role of the gut in glucose control. The improvement of type 2 diabetes after gastric bypass surgery occurs via weight dependent and weight independent mechanisms. The rapid improvement of glucose levels within days after the surgery, in relation to change of meal pattern, rapid nutrient transit, enhanced incretin release and improved incretin effect on insulin secretion, suggest mechanisms independent of weight loss. Alternatively, insulin sensitivity improves over time as a function of weight loss. The role of bile acids and microbiome in the metabolic improvement after bariatric surgery remains to be determined. While most patients after bariatric surgery experienced sustained weight loss and improved metabolism, small scale studies have shown weight regain and diabetes relapse, the mechanisms of which remain unknown. Topics: Bariatric Surgery; Bile Acids and Salts; Blood Glucose; Diabetes Mellitus, Type 2; Dipeptidyl Peptidase 4; Follow-Up Studies; Gastric Bypass; Gastric Inhibitory Polypeptide; Gastrointestinal Hormones; Gastrointestinal Tract; Glucagon-Like Peptide 1; Humans; Incretins; Insulin Resistance; Malnutrition; Metagenome; Obesity; Recurrence; Weight Loss | 2012 |
Potential cardiovascular effects of incretin-based therapies.
Glucagon-like peptide (GLP)-1 agonists and dipeptidyl peptidase-4 inhibitors are two classes of drugs that have been approved for treatment of Type 2 diabetes mellitus, based upon the glucose-lowering actions of the gastrointestinal hormone GLP-1. However, GLP-1 receptors are also present in cardiovascular tissues. Data from animal and in vitro studies suggest that GLP-1 may have cardioprotective effects and improve myocardial and endothelial dysfunction. Clinical data demonstrating cardiovascular effects are more limited, and there is some evidence that incretin-based therapies may be associated with improvements in cardiovascular risk factors. Large prospective cardiovascular outcome trials are underway to examine the cardiovascular safety of incretin-based therapies, and may reveal whether these agents are associated with any reduction in cardiovascular adverse events in patients with Type 2 diabetes mellitus. Topics: Animals; Cardiovascular Diseases; Diabetes Mellitus, Type 2; Glucagon-Like Peptide 1; Humans; Incretins; Risk Factors | 2012 |
The design of the liraglutide clinical trial programme.
Liraglutide is a once-daily human glucagon-like peptide-1 analogue used in the treatment of type 2 diabetes (T2D). It has been prospectively investigated in a series of multinational, randomised, controlled phase 3 trials (the Liraglutide Effect and Action in Diabetes programme), as well as in an additional direct head-to-head study with sitagliptin. These trials were designed to clarify the use and safety of liraglutide in clinical practice across the treatment continuum of T2D, and consequently involved a large number and diverse range of patients. These studies also included active comparisons against antidiabetic agents including metformin, rosiglitazone, glimepiride, insulin glargine, exenatide and sitagliptin, and therefore have helped to examine clinical differences and similarities between liraglutide and these commonly used agents. Topics: Blood Glucose; Clinical Trials, Phase III as Topic; Diabetes Mellitus, Type 2; Drug Therapy, Combination; Exenatide; Female; Glucagon-Like Peptide 1; Glycated Hemoglobin; Humans; Hypoglycemic Agents; Insulin Glargine; Insulin, Long-Acting; Liraglutide; Male; Metformin; Peptides; Pyrazines; Randomized Controlled Trials as Topic; Rosiglitazone; Sitagliptin Phosphate; Sulfonylurea Compounds; Thiazolidinediones; Treatment Outcome; Triazoles; Venoms | 2012 |
Liraglutide in oral antidiabetic drug combination therapy.
The glucagon-like peptide-1 (GLP-1) receptor agonist liraglutide is indicated as an add-on to oral antidiabetic drug regimens in subjects with type 2 diabetes. Herein, the results of clinical trials assessing the efficacy, safety and tolerability of liraglutide when used in combination with either one or two oral antidiabetic therapies are summarised, then contrasted with the effects of exenatide and dipeptidyl peptidase (DPP-4) inhibitors. GLP-1 receptor agonists lead to effective glycaemic control when used as combination therapy with either one or two oral antidiabetic agents, and may confer overall benefits in weight loss and blood pressure in some subjects. These agents are well tolerated; the most commonly reported adverse effect is mild-to-moderate gastrointestinal symptoms, which are usually transient. Rates of hypoglycaemia in these trials were low, although higher rates were noted when combined with a sulphonylurea. While further study will be required, GLP-1 receptor agonists may offer important advantages over other diabetic therapies, including DPP-4 inhibitors. Topics: Administration, Oral; Blood Glucose; Diabetes Mellitus, Type 2; Dipeptidyl-Peptidase IV Inhibitors; Drug Therapy, Combination; Exenatide; Female; Glucagon-Like Peptide 1; Glucagon-Like Peptide-1 Receptor; Humans; Hypoglycemic Agents; Liraglutide; Male; Peptides; Randomized Controlled Trials as Topic; Receptors, Glucagon; Treatment Outcome; Venoms | 2012 |
Comparison of liraglutide versus other incretin-related anti-hyperglycaemic agents.
The two classes of incretin-related therapies, dipeptidyl peptidase-4 (DPP-4) inhibitors and glucagon-like peptide-1 receptor agonists (GLP-1 RAs), have become important treatment options for patients with type 2 diabetes. Sitagliptin, saxagliptin, vildagliptin and linagliptin, the available DPP-4 inhibitors, are oral medications, whereas the GLP-1 RAs-twice-daily exenatide, once-weekly exenatide and once-daily liraglutide-are administered subcutaneously. By influencing levels of GLP-1 receptor stimulation, these medications lower plasma glucose levels in a glucose-dependent manner with low risk of hypoglycaemia, affecting postprandial plasma glucose more than most other anti-hyperglycaemic medications. Use of GLP-1 RAs has been shown to result in greater glycaemic improvements than DPP-4 inhibitors, probably because of higher levels of GLP-1 receptor activation. GLP-1 RAs can also produce significant weight loss and may reduce blood pressure and have beneficial effects on other cardiovascular risk factors. Although both classes are well tolerated, DPP-4 inhibitors may be associated with infections and headaches, whereas GLP-1 RAs are often associated with gastrointestinal disorders, primarily nausea. Pancreatitis has been reported with both DPP-4 inhibitors and GLP-1 RAs, but a causal relationship between use of incretin-based therapies and pancreatitis has not been established. In clinical trials, liraglutide has shown efficacy and tolerability and resulted in certain significant benefits when compared with exenatide and sitagliptin. Topics: Administration, Oral; Blood Glucose; Blood Pressure; Cardiovascular Diseases; Diabetes Mellitus, Type 2; Dipeptidyl-Peptidase IV Inhibitors; Dose-Response Relationship, Drug; Drug Administration Schedule; Exenatide; Female; Glucagon-Like Peptide 1; Humans; Hyperglycemia; Hypoglycemic Agents; Incretins; Injections, Subcutaneous; Liraglutide; Male; Peptides; Randomized Controlled Trials as Topic; Risk Factors; Venoms; Weight Loss | 2012 |
Liraglutide: from clinical trials to clinical practice.
Liraglutide, a once-daily glucagon-like peptide-1 receptor agonist, is approved for use as monotherapy in the USA and Japan (but not in Europe or Canada) and in combination with selected oral agents (all regions) for the treatment of patients with type 2 diabetes. Guidance from local advisory bodies is emerging on the most appropriate place for liraglutide in the treatment pathway. It is apparent from its phase 3 clinical trial programme that liraglutide provides superior glycaemic control compared with that achieved with other antidiabetic agents used early in the treatment pathway (e.g. glimepiride and sitagliptin). Key additional benefits include a low incidence of hypoglycaemia and clinically relevant weight loss, although these benefits may be ameliorated by concomitant sulphonylurea (SU) treatment and, in the case of hypoglycaemia, reduction of the SU dose may be necessary. Overall, the profile of liraglutide is similar and, in some aspects, superior to twice-daily exenatide. The implementation of liraglutide therapy is straightforward, with simple dose titration from the starting dose of 0.6 to 1.2 mg/day after 1 week; some patients may benefit from additional titration to 1.8 mg/day. Treatment is self-administered by subcutaneous injection. This contrasts with other agents used early in the treatment pathway, but clinical data suggest patients' overall treatment satisfaction with liraglutide is similar (1.2 mg) or better (1.8 mg) than that with sitagliptin despite differing administration methods. Some patients may experience nausea when initiating liraglutide treatment, but the titration regimen is designed to improve tolerability and clinical data indicate nausea is transient. Topics: Administration, Oral; Blood Glucose; Clinical Trials as Topic; Diabetes Mellitus, Type 2; Dose-Response Relationship, Drug; Drug Administration Schedule; Drug Therapy, Combination; Female; Glucagon-Like Peptide 1; Humans; Hypoglycemia; Hypoglycemic Agents; Injections, Subcutaneous; Liraglutide; Male; Metformin; Nausea; Sulfonylurea Compounds; Thiazolidinediones; Treatment Outcome; United States | 2012 |
Non-glycaemic effects mediated via GLP-1 receptor agonists and the potential for exploiting these for therapeutic benefit: focus on liraglutide.
The glucagon-like peptide-1 receptor agonists (GLP-1 RAs) liraglutide and exenatide can improve glycaemic control by stimulating insulin release through pancreatic β-cells in a glucose-dependent manner. GLP-1 receptors are not restricted to the pancreas; therefore, GLP-1 RAs cause additional non-glycaemic effects. Preclinical and clinical trial data suggest a multitude of additional beneficial effects related to GLP-1 RA therapy, including improvements in β-cell function, systolic blood pressure and body weight. These effects are of a particular advantage to patients with type 2 diabetes, as most are affected by β-cell dysfunction, obesity and hypertension. Transient gastrointestinal adverse events, such as nausea and diarrhoea, are also common. To improve gastrointestinal tolerability, an incremental dosing approach is used with liraglutide and exenatide twice daily. A potential protective role for GLP-1 RAs in the cardiovascular and central nervous systems has been suggested from animal studies and short-term clinical trials. These effects and other safety aspects of GLP-1 therapy are currently being investigated in ongoing long-term clinical studies. Topics: Blood Glucose; Blood Pressure; Diabetes Mellitus, Type 2; Female; Glucagon-Like Peptide 1; Glucagon-Like Peptide-1 Receptor; Humans; Hypertension; Incretins; Insulin-Secreting Cells; Liraglutide; Male; Neuroprotective Agents; Receptors, Glucagon; Weight Loss | 2012 |
Dipeptidyl peptidase-4 inhibitors for treatment of type 2 diabetes mellitus in the clinical setting: systematic review and meta-analysis.
To assess the efficacy and safety of dipeptidyl peptidase-4 (DPP-4) inhibitors compared with metformin as monotherapy, or with other commonly used hypoglycaemic drugs combined with metformin, in adults with type 2 diabetes mellitus.. Systematic review and meta-analysis of randomised controlled trials.. Medline, Embase, the Cochrane Library, conference proceedings, trial registers, and drug manufacturers' websites.. Randomised controlled trials of adults with type 2 diabetes mellitus that compared a DPP-4 with metformin as monotherapy or with a sulfonylurea, pioglitazone, a glucagon-like peptide-1 (GLP-1) agonist, or basal insulin combined with metformin on the change from baseline in glycated haemoglobin (HbA(1c)).. The primary outcome was the change in HbA(1c). Secondary outcomes included the proportion of patients achieving the goal of HbA(1c) <7%, the change in body weight, discontinuation rate because of any adverse event, occurrence of any serious adverse event, all cause mortality, and incidence of hypoglycaemia, nasopharyngitis, urinary tract infection, upper respiratory infection, nausea, vomiting, and diarrhoea.. 27 reports of 19 studies including 7136 patients randomised to a DPP-4 inhibitor and 6745 patients randomised to another hypoglycaemic drug were eligible for the systematic review and meta-analysis. Overall risk of bias for the primary outcome was low in three reports, unclear in nine, and high in 14. Compared with metformin as monotherapy, DPP-4 inhibitors were associated with a smaller decline in HbA(1c) (weighted mean difference 0.20, 95% confidence interval 0.08 to 0.32) and in body weight (1.5, 0.9 to 2.11). As a second line treatment, DPP-4 inhibitors were inferior to GLP-1 agonists (0.49, 0.31 to 0.67) and similar to pioglitazone (0.09, -0.07 to 0.24) in reducing HbA(1c) and had no advantage over sulfonylureas in the attainment of the HbA(1c) goal (risk ratio in favour of sulfonylureas 1.06, 0.98 to 1.14). DPP-4 inhibitors had a favourable weight profile compared with sulfonylureas (weighted mean difference -1.92, -2.34 to -1.49) or pioglitazone (-2.96, -4.13 to -1.78), but not compared with GLP-1 agonists (1.56, 0.94 to 2.18). Only a minimal number of hypoglycaemias were observed in any treatment arm in trials comparing a DPP-4 inhibitor with metformin as monotherapy or with pioglitazone or a GLP-1 agonist as second line treatment. In most trials comparing a DPP-4 inhibitor with sulfonylureas combined with metformin, the risk for hypoglycaemia was higher in the group treated with a sulfonylurea. Incidence of any serious adverse event was lower with DPP-4 inhibitors than with pioglitazone. Incidence of nausea, diarrhoea, and vomiting was higher in patients receiving metformin or a GLP-1 agonist than in those receiving a DPP-4 inhibitor. Risk for nasopharyngitis, upper respiratory tract infection, or urinary tract infection did not differ between DPP-4 inhibitors and any of the active comparators.. In patients with type 2 diabetes who do not achieve the glycaemic targets with metformin alone, DPP-4 inhibitors can lower HbA(1c), in a similar way to sulfonylureas or pioglitazone, with neutral effects on body weight. Increased unit cost, which largely exceeds that of the older drugs, and uncertainty about their long term safety, however, should also be considered. Topics: Adult; Blood Glucose; Body Weight; Diabetes Mellitus, Type 2; Dipeptidyl-Peptidase IV Inhibitors; Disease Management; Drug Monitoring; Female; Glucagon-Like Peptide 1; Glycated Hemoglobin; Humans; Hypoglycemia; Hypoglycemic Agents; Insulin; Male; Metformin; Outcome Assessment, Health Care; Randomized Controlled Trials as Topic; Sulfonylurea Compounds; Treatment Outcome | 2012 |
GLP-1 and cardioprotection: from bench to bedside.
During myocardial infarction (MI), a variety of mechanisms contribute to the activation of cell death processes in cardiomyocytes, determining the final MI size, subsequent mortality, and post-MI remodelling. The deleterious mechanisms accompanying the ischaemic and reperfusion phases in MI include deprivation of oxygen, nutrients, and survival factors, accumulation of waste products, generation of oxygen free radicals, calcium overload, neutrophil infiltration of the ischaemic area, depletion of energy stores, and opening of the mitochondrial permeability transition pore, all of which contribute to the activation of apoptosis and necrosis in cardiomyocytes. During the last few years, glucagon-like peptide-1 (GLP-1) (7-36)-based therapeutic strategies have been incorporated into the treatment of patients with type 2 diabetes mellitus. Cytoprotection is among the pleiotropic actions described for GLP-1 in different cell types, including cardiomyocytes. This paper reviews the most relevant experimental and clinical studies that have contributed to a better understanding of the molecular mechanisms and intracellular pathways involved in the cardioprotection induced by GLP-1, analysing in depth its potential role as a therapeutic target in the ischaemic and reperfused myocardium as well as in other pathologies that are associated with myocardial remodelling and heart failure. Topics: Animals; Apoptosis; Cardiotonic Agents; Diabetes Mellitus, Type 2; Glucagon-Like Peptide 1; Heart Failure; Humans; Myocardial Infarction; Myocardial Reperfusion Injury; Myocardium; Myocytes, Cardiac; Necrosis | 2012 |
Patient-reported outcomes in trials of incretin-based therapies in patients with type 2 diabetes mellitus.
Incretin-based therapies have a glucose-dependent mode of action that results in excellent glucose-lowering efficacy with very low risk of hypoglycaemia, and weight neutrality [dipeptidyl peptidase-4 (DPP-4) inhibitors] or weight loss [glucagon-like peptide-1 (GLP-1) receptor agonists], in people with type 2 diabetes mellitus (T2DM). Patient-reported outcomes (PROs) complement physician evaluations of efficacy and tolerability and offer insights into the subjective experience of using modern diabetes treatments. We conducted a systematic search of clinical trials of the GLP-1 receptor agonists liraglutide, exenatide and long-acting exenatide, one of which included the oral DPP-4 inhibitor sitagliptin as a comparator. No other PRO data for DPP-4 inhibitors were identified. This review summarizes PRO data from eight clinical trials, the majority of which used the Diabetes Treatment Satisfaction Questionnaire (DTSQ) and/or Impact of Weight on Quality of Life-Lite (IWQOL-Lite) to evaluate patient experience. People with T2DM were highly satisfied with modern incretin-based therapies compared with traditional therapies. Treatment satisfaction (including perceptions of convenience and flexibility) was high and generally higher with GLP-1 agonists in association with their greater glucose-lowering efficacy and tendency to facilitate weight loss. Weight-related quality of life (QoL) also improved in people using incretin therapies. The glycaemic improvements achieved with GLP-1 receptor agonists, coupled with the low incidence of hypoglycaemia and ability to cause weight loss, seemed to offset potential concern about injections. It is plausible that superior patient-reported benefits found in clinical trials may translate into improved, clinically meaningful, long-term outcomes through increased treatment acceptability. Long-term, prospective data are needed to ascertain whether this is the case in practice. Topics: Clinical Trials as Topic; Diabetes Mellitus, Type 2; Dipeptidyl-Peptidase IV Inhibitors; Dose-Response Relationship, Drug; Drug Administration Schedule; Exenatide; Female; Glucagon-Like Peptide 1; Glycated Hemoglobin; Humans; Hyperglycemia; Hypoglycemic Agents; Incretins; Injections, Subcutaneous; Liraglutide; Male; Medication Adherence; Patient Satisfaction; Peptides; Pyrazines; Self Care; Sitagliptin Phosphate; Surveys and Questionnaires; Treatment Outcome; Triazoles; Venoms; Weight Loss | 2012 |
Clinical implications of cardiovascular preventing pleiotropic effects of dipeptidyl peptidase-4 inhibitors.
Dipeptidyl peptidase-4 (DPP-4) inhibitors are novel drugs for the treatment of type 2 diabetes mellitus. They exert their action through inhibition of the catabolism of locally secreted incretins such as glucagon-like peptide-4 (GLP-4) and glucose-dependent insulinotropic polypeptide (GIP) by inhibiting enzyme DPP-4. GLP-1 and GIP are secreted from the gastrointestinal tract in response to food intake. GLP-1 is secreted from L cells present in the mucosa of the small intestine and colon, whereas GIP is secreted from K cells of the jejunum. These 2 incretins lower blood glucose levels and postprandial hyperglycemia by stimulating insulin release from b cells of the pancreas, thus increasing insulin sensitivity, delaying gastrointestinal emptying, decreasing food intake through early satiety, and causing weight loss in the long term. However, their action is short-lived (2 to 3 minutes) because of catabolism by the DPP-4 enzyme. The importance of DPP-4 inhibitors lies in their blockade of the DPP-4 enzyme leading to the prevention of their catabolism and thus increasing their blood levels, extending the duration of their action, and improving their blood glucose-lowering effect. In addition to their antidiabetic action, recent experimental and clinical studies have demonstrated a pleiotropic cardiovascular protective effect of these agents independent of their antidiabetic action. They prevent atherosclerosis, improve endothelial dysfunction, lower blood pressure, and prevent myocardial injury. All these actions are discussed in this concise review. In conclusion, DPP-4 inhibitors are novel antidiabetic agents with pleiotropic cardiovascular protective effects in addition to their antidiabetic action. Topics: Animals; Cardiotonic Agents; Cardiovascular Diseases; Diabetes Mellitus, Type 2; Dipeptidyl-Peptidase IV Inhibitors; Endothelium, Vascular; Gastric Inhibitory Polypeptide; Glucagon-Like Peptide 1; Heart; Humans; Hypertension; Incretins; Receptors, Glucagon | 2012 |
An update in incretin-based therapy: a focus on dipeptidyl peptidase--4 inhibitors.
Dipeptidyl peptidase -4 inhibitors represent a novel way to augment the incretin system and one of the newest class of medications in the treatment of type 2 diabetes mellitus. Their mechanism of action is to decrease the inactivation of glucagon-like peptide 1 and glucose-dependent insulinotropic polypeptide, both of which are involved in maintaining euglycemia subsequent to carbohydrate intake. Currently investigated agents include sitagliptin, vildagliptin, saxagliptin, linagliptin, and alogliptin. Each agent has been shown to provide significant improvements in glycemic control compared to placebo. They are effective when added to other oral diabetes agents and in the cases of sitagliptin, vildagliptin, and alogliptin in addition to insulin. These agents may not provide as significant improvement in glucose concentrations as some other medications including metformin, thiazolidinediones, or glucagon-like peptide 1 agonists. The lack of head to head clinical data comparing the various dipeptidyl peptidase 4 inhibitors does not allow for specific recommendations if one agent is more effective or safer than another within the class. Their side effect profile suggests they are very well tolerated and have few drug interactions. For patients with mildly elevated glucose concentrations, they are therapeutic options in both drug-naive patients as well as those not optimally controlled on other diabetes medications. Topics: Adamantane; Blood Glucose; Diabetes Mellitus, Type 2; Dipeptides; Dipeptidyl-Peptidase IV Inhibitors; Drug Interactions; Female; Glucagon-Like Peptide 1; Humans; Linagliptin; Male; Nitriles; Piperidines; Purines; Pyrazines; Pyrrolidines; Quinazolines; Sitagliptin Phosphate; Treatment Outcome; Triazoles; Uracil; Vildagliptin | 2012 |
The novel use of GLP-1 analogue and insulin combination in type 2 diabetes mellitus.
Type 2 diabetes mellitus (T2DM) is a global public health problem. Due to the progressive nature of the disease, a combination(s) of two or more drugs acting on different pathophysiological process is often necessary to achieve early and sustained achievement of individualized glycemic targets. At the same time, choosing the safest option to avoid hypoglycemia is of paramount importance. GLP-1 analogues are a relatively recent class of anti-diabetic drugs, and are highly effective with an acceptable safety profile. Attempts have been made to combine GLP-1 analogues with basal insulin for management of T2DM. Presently GLP-1 analogues like exenatide/long acting exenatide and liraglutide have been co-administered with basal insulin like glargine and detemir respectively, and are approved by regulatory agencies. Currently a fixed dose combination (FDC) of insulin degludec and liraglutide is under development. GLP-1 analogue and insulin as FDC or by co-administration, is a rational method of controlling fasting and postprandial glucose effectively. The efficacy and safety of this combination has been studied in a wide population with promising outcomes. Innovative use of GLP-1 analogues beyond diabetes is also being attempted, and a variety of patents are filed or granted for the same. This review summarizes the current status of GLP-1 and insulin combination in the management of T2DM and highlights the new frontiers in research involving GLP-1. Patents on combination of GLP-1 and insulin which were granted earlier, and the ones which have been applied for, are also discussed. Topics: Diabetes Mellitus, Type 2; Drug Combinations; Drug Therapy, Combination; Exenatide; Glucagon-Like Peptide 1; Humans; Hypoglycemic Agents; Insulin, Long-Acting; Liraglutide; Peptides; Venoms | 2012 |
Glycaemic efficacy of glucagon-like peptide-1 receptor agonists and dipeptidyl peptidase-4 inhibitors as add-on therapy to metformin in subjects with type 2 diabetes-a review and meta analysis.
During recent years, two strategies of incretin-based therapy [glucagon-like peptide-1 (GLP-1) receptor agonism and dipeptidyl peptidase-4 (DPP-4) inhibition] have entered the market for pharmacological management of type 2 diabetes. A main indication for this therapy is as add-on to on-going metformin therapy in subjects with type 2 diabetes who have insufficient glycaemic control with metformin alone. The aim of this study was to compare improvements in glycaemic control and changes in body weight, as well as adverse events, in comparable studies with incretin-based therapy as add-on to metformin.. Studies having a duration of 16-30 weeks were identified from PubMed.. A total of 27 study groups in 21 studies fulfilled the criteria of examining incretin-based therapy as add-on to metformin at clinically recommended doses in patients with type 2 diabetes for 16-30 weeks; 7 of these used a short-acting GLP-1 receptor agonist (exenatide BID), 7 used longer acting GLP-1 receptor agonists (liraglutide or exenatide LAR), whereas 14 studies examined DPP-4 inhibitors. In all studies, incretin-based therapy reduced HbA1c concentrations. The reduction in HbA1c was significantly greater in study groups with long-acting GLP-1 receptor agonists than with the other two groups (both p < 0.001), whereas there were no differences between exenatide BID and DPP-4 inhibitors. Across all study groups, there was a negative linear correlation between baseline HbA1c and change in HbA1c (r = -0.70; p < 0.001). Fasting glucose also fell significantly more in study groups given liraglutide or exenatide LAR than in those given exenatide BID or DPP-4 inhibitors (both p < 0.001). Furthermore, body weight was reduced by a similar extent in the two groups with GLP-1 receptor agonists and was not significantly altered in the groups with DPP-4 inhibitors. Lipids, blood pressure and heart rate were not reported consistently, which did not allow general conclusions. Adverse events were rare, apart from increased incidence of nausea and vomiting with GLP-1 receptor agonists.. Incretin-based therapy efficiently improves glycaemia when added to metformin in patients with type 2 diabetes, and within 16-30 weeks there is a more pronounced reduction in HbA1c with long-acting GLP-1 receptor agonists (liraglutide and exenatide LAR) than with exenatide BID and DPP-4 inhibitors, although the magnitude of the effect is dependent on the baseline values. Both strategies appear to be associated with a very low risk of adverse events, including hypoglycaemia. Finally, the injectable GLP-1 receptor agonists also reduce body weight (whereas the DPP-4 inhibitors are weight neutral) but are also associated with a greater incidence of gastrointestinal side effects and a tendency to increase heart rate. Topics: Blood Glucose; Body Weight; Diabetes Mellitus, Type 2; Dipeptidyl-Peptidase IV Inhibitors; Exenatide; Fasting; Female; Glucagon-Like Peptide 1; Glucagon-Like Peptide-1 Receptor; Humans; Hypoglycemic Agents; Liraglutide; Male; Peptides; Pyrazines; Receptors, Glucagon; Sitagliptin Phosphate; Treatment Outcome; Triazoles; Venoms | 2012 |
GLP-1 receptor agonists: a clinical perspective on cardiovascular effects.
The active incretin hormone glucagon-like peptide-1(7-36)amide (GLP-1) is a 30-amino acid peptide that exerts glucoregulatory and insulinotropic actions by functioning as an agonist for the GLP-1 receptor (GLP-1R). In addition to its anti-diabetic effects, GLP-1 has demonstrated cardioprotective actions. Here we review the cardiovascular effects of the GLP-1 analogues currently approved for the treatment of type 2 diabetes, namely exenatide and liraglutide. We discuss their anti-hyperglycaemic efficacy, and offer a clinical perspective of their effects on cardiovascular risk factors such as body weight, blood pressure, heart rate and lipid profiles, as well as their potential consequences on cardiovascular events, such as arrhythmias, heart failure, myocardial infarction and death. Lastly, we briefly review additional GLP-1R agonists in clinical development. Topics: Animals; Biomarkers; Blood Glucose; Cardiovascular Diseases; Diabetes Mellitus, Type 2; Drug Design; Evidence-Based Medicine; Exenatide; Glucagon-Like Peptide 1; Glucagon-Like Peptide-1 Receptor; Glycated Hemoglobin; Humans; Hypoglycemic Agents; Liraglutide; Peptides; Receptors, Glucagon; Risk Assessment; Risk Factors; Time Factors; Treatment Outcome; Venoms | 2012 |
Pharmacotherapy in type 2 diabetes: a functional schema for drug classification.
With growing awareness that long-term hyperglycemia is directly implicated in the tissue damage characteristic of diabetes, there has been a corresponding increase in clinicians' willingness to employ intensive treatment to achieve euglycemia, which may require diabetes drugs in combination. The expanding array of drugs with different mechanisms of action calls for a clear method of classification to guide rational combination therapy. Contemporary and historical literature was surveyed to document changes in awareness of toxicity from hyperglycemia and consequent changes in treatment strategy. References were selected for clinical applicability and explanation of drug mechanisms of action, with the goal of proposing a useful schema for classification. Diabetes drugs may be classified in the following categories: insulin providers, which increase the supply of insulin through administration of exogenous human insulin or analogues or drugs that stimulate endogenous insulin secretion (sulfonylureas and meglitinides are direct insulin secretagogues, whereas glucagon- like peptide-1 analogues and dipeptidyl peptidase-4 inhibitors act to increase the supply of insulin); insulin sensitizers (metformin, thiazolidinediones), which offset the effects of insulin resistance; and insulin-independent drugs, which work in the gut to impede intestinal absorption of glucose into the circulation (α-glucosidase inhibitors) or in the kidney to prevent renal reabsorption of glucose back into the circulation (sodium-glucose cotransporter 2 inhibitors, currently investigational). Awareness of these categories facilitates rational combinations of drugs with differing mechanisms of action to address hyperglycemia from separate directions, in accordance with current treatment guidelines. Topics: Diabetes Mellitus, Type 2; Dipeptidyl-Peptidase IV Inhibitors; Glucagon-Like Peptide 1; Humans; Hyperglycemia; Hypoglycemic Agents; Insulin; Insulin Resistance; Sodium-Glucose Transporter 2; Sulfonylurea Compounds; Thiazolidinediones | 2012 |
Current treatments and strategies for type 2 diabetes: can we do better with GLP-1 receptor agonists?
Abstract Diet, lifestyle modification, and pharmacotherapy with metformin are appropriate initial treatments for many patients with type 2 diabetes (T2DM). However, most individuals do not maintain glycemic control with metformin alone. Addition of other oral antidiabetes drugs (OADs), including sulfonylurea, meglitinide, or thiazolidinedione, is often the next step. Newer options, including incretin-based glucagon-like peptide-1 (GLP-1) receptor agonists (RAs) and dipeptidyl peptidase-4 (DPP-4) inhibitors, offer important benefits as monotherapies or in combination with OADs, with low risk for hypoglycemia. Reductions in glycated hemoglobin (A1C) have been reported among patients treated with GLP-1 RAs (exenatide, -0.8 to -1.1%; liraglutide, -0.8 to -1.6%), as has weight loss (exenatide, -1.6 to -3.1 kg; liraglutide, -1.6 to -3.2 kg). GLP-1 RAs also stimulate β-cell responses and have positive effects on cardiovascular risk factors often present in patients with T2DM. The most common adverse events associated with GLP-1 RAs are nausea, which diminishes over time, and hypoglycemia (when used in combination with a sulfonylurea). A large number of trials demonstrated benefits of GLP-1 RAs, suggesting they could provide suitable treatment options for patients with T2DM. Topics: Blood Glucose; Diabetes Mellitus, Type 2; Exenatide; Glucagon-Like Peptide 1; Glucagon-Like Peptide-1 Receptor; Humans; Hypoglycemia; Hypoglycemic Agents; Incretins; Liraglutide; Peptides; Receptors, Glucagon; Venoms | 2012 |
Mechanisms of improved glycaemic control after Roux-en-Y gastric bypass.
Roux-en-Y gastric bypass (RYGB) greatly improves glycaemic control in morbidly obese patients with type 2 diabetes, in many even before significant weight loss. Understanding the responsible mechanisms may contribute to our knowledge of the pathophysiology of type 2 diabetes and help identify new drug targets or improve surgical techniques. This review summarises the present knowledge based on pathophysiological studies published during the last decade. Taken together, two main mechanisms seem to be responsible for the early improvement in glycaemic control after RYGB: (1) an increase in hepatic insulin sensitivity induced, at least in part, by energy restriction and (2) improved beta cell function associated with an exaggerated postprandial glucagon-like peptide 1 secretion owing to the altered transit of nutrients. Later a weight loss induced improvement in peripheral insulin sensitivity follows. Topics: Blood Glucose; Diabetes Mellitus, Type 2; Female; Gastric Bypass; Glucagon-Like Peptide 1; Glucose Tolerance Test; Humans; Insulin Resistance; Insulin-Secreting Cells; Male; Obesity, Morbid; Time Factors; Treatment Outcome | 2012 |
Cardiovascular benefits of GLP-1-based herapies in patients with diabetes mellitus type 2: effects on endothelial and vascular dysfunction beyond glycemic control.
Type 2 diabetes mellitus (T2DM) is a progressive multisystemic disease accompanied by vascular dysfunction and a tremendous increase in cardiovascular mortality. Numerous adipose-tissue-derived factors and beta cell dysfunction contribute to the increased cardiovascular risk in patients with T2DM. Nowadays, numerous pharmacological interventions are available to lower blood glucose levels in patients with type 2 diabetes. Beside more or less comparable glucose lowering efficacy, some of them have shown limited or probably even unfavorable effects on the cardiovascular system and overall mortality. Recently, incretin-based therapies (GLP-1 receptor agonists and DPP-IV inhibitors) have been introduced in the treatment of T2DM. Beside the effects of GLP-1 on insulin secretion, glucagon secretion, and gastrointestinal motility, recent studies suggested a couple of direct cardiovascular effects of GLP-1-based therapies. The goal of this paper is to provide an overview about the current knowledge of direct GLP-1 effects on endothelial and vascular function and potential consequences on the cardiovascular outcome in patients with T2DM treated with GLP-1 receptor agonists or DPP-IV inhibitors. Topics: Blood Glucose; Body Weight; Diabetes Mellitus, Type 2; Diabetic Angiopathies; Dipeptidyl-Peptidase IV Inhibitors; Endothelium, Vascular; Glucagon-Like Peptide 1; Humans; Hypoglycemic Agents | 2012 |
Incretin therapy and its effect on body weight in patients with diabetes.
Glucagon-like peptide 1 (GLP-1) analogues and dipeptidyl peptidase-4 (DPP-4) inhibitors are two classes of treatments for type 2 diabetes, which enhance the well-known 'incretin effect' of increased insulin secretion in response to food intake. This concise review introduces both types of incretin-based therapies and focuses on the extra-pancreatic effect of GLP-1 on body weight. As well as improving glycaemic control in subjects with type 2 diabetes, these treatments have the additional benefits of improving weight management in these patients, with GLP-1 receptor agonists causing weight loss and DPP-4 inhibitors being weight neutral. Topics: Body Weight; Diabetes Mellitus, Type 2; Dipeptidyl-Peptidase IV Inhibitors; Glucagon-Like Peptide 1; Humans; Hypoglycemic Agents; Incretins; Treatment Outcome | 2012 |
Incretin therapies in the management of patients with type 2 diabetes mellitus and renal impairment.
Renal impairment (RI) is common among patients with type 2 diabetes mellitus (T2DM), and these patients also experience an age-related decline in renal function. At the same time, treatment options are more limited and treatment is more complex, particularly in patients with moderate or severe RI due to contraindications, need for dose adjustment and/or regular monitoring, and side effects, such as fluid retention and hypoglycemia, which are a more serious concern in this patient population. Incretin therapies, consisting of the injectable glucagon-like peptide-1 (GLP-1) receptor agonists and the oral dipeptidyl peptidase-4 (DPP-4) inhibitors, are a promising new class of antihyperglycemic drugs. In the overall population, they improve glycemic control in a glucose-dependent manner and are not likely to cause hypoglycemia, representing a clear advantage in at-risk populations. Data regarding use of these agents in renally impaired patients have started to emerge, and the objective of this article is to provide an overview of the currently available data and the potential role of these novel agents in the management of patients with T2DM and RI. Data for the GLP-1 receptor agonists in patients with moderate or severe RI are still limited, with no trials dedicated to these populations currently published. In addition, their potential to cause gastrointestinal side effects may limit use in patients with RI due to the risk of dehydration and hypovolemia. The use of GLP-1 receptor agonists in patients with moderate or severe RI is therefore, at present, underlying caution and/or restrictions. On the other hand, data from specific trials in patients with moderate or severe RI are now becoming available for most of the DPP-4 inhibitors. These studies demonstrate good efficacy and tolerability of the DPP-4 inhibitors in patients with moderate or severe RI, thus opening a place for these therapies in the treatment of populations with T2DM and RI. Several of the DPP-4 inhibitors are already approved for use in patients with moderate or severe RI, including for those with end-stage renal disease. While discussing the advantages related to their common mechanism of action, this article also describes differences among the DPP-4 inhibitors (eg, related to their pharmacokinetic properties and the available clinical data). In conclusion, while initial data for these new therapies are promising, further experience is needed to fully assess the risk-benefit balance and cl Topics: Administration, Oral; Clinical Trials as Topic; Diabetes Mellitus, Type 2; Diabetic Nephropathies; Dipeptidyl-Peptidase IV Inhibitors; Glucagon-Like Peptide 1; Humans; Incretins; Injections, Intravenous | 2012 |
Physiology and emerging biochemistry of the glucagon-like peptide-1 receptor.
The glucagon-like peptide-1 (GLP-1) receptor is one of the best validated therapeutic targets for the treatment of type 2 diabetes mellitus (T2DM). Over several years, the accumulation of basic, translational, and clinical research helped define the physiologic roles of GLP-1 and its receptor in regulating glucose homeostasis and energy metabolism. These efforts provided much of the foundation for pharmaceutical development of the GLP-1 receptor peptide agonists, exenatide and liraglutide, as novel medicines for patients suffering from T2DM. Now, much attention is focused on better understanding the molecular mechanisms involved in ligand induced signaling of the GLP-1 receptor. For example, advancements in biophysical and structural biology techniques are being applied in attempts to more precisely determine ligand binding and receptor occupancy characteristics at the atomic level. These efforts should better inform three-dimensional modeling of the GLP-1 receptor that will help inspire more rational approaches to identify and optimize small molecule agonists or allosteric modulators targeting the GLP-1 receptor. This article reviews GLP-1 receptor physiology with an emphasis on GLP-1 induced signaling mechanisms in order to highlight new molecular strategies that help determine desired pharmacologic characteristics for guiding development of future nonpeptide GLP-1 receptor activators. Topics: Allosteric Site; Biochemistry; Crystallography, X-Ray; Cyclic AMP; Diabetes Mellitus, Type 2; Exenatide; Glucagon-Like Peptide 1; Glucagon-Like Peptide-1 Receptor; Glucose; Homeostasis; Humans; Ligands; Liraglutide; Models, Biological; Peptides; Protein Binding; Receptors, Glucagon; Signal Transduction; Venoms | 2012 |
Harnessing the incretin system beyond glucose control: potential cardiovascular benefits of GLP-1 receptor agonists in type 2 diabetes.
The management of type 2 diabetes continues to evolve as new data emerge. Although glycaemic control is still important, other risk factors--such as hypertension, dyslipidaemia and obesity--must also be addressed in order to reduce the long-term risks of cardiovascular complications and mortality. In this context, targeting the incretin system, and glucagon-like peptide-1 (GLP-1) in particular, has generated much interest. GLP-1 is released from the gut in response to food ingestion and plays a crucial role in glucose homeostasis. GLP-1 receptors are expressed in the heart and vasculature, prompting evaluation of their physiological role and pharmacological stimulation, both in healthy and disease states. These studies indicate that GLP-1 and GLP-1-based therapies appear to have direct, beneficial effects on the cardiovascular system, in addition to their glucose-lowering properties, such as modulation of blood pressure, endothelial function, and myocardial contractility. Intriguingly, some of these effects appear to be independent of GLP-1 receptor signalling. Data from clinical studies of the GLP-1 receptor agonists, exenatide and liraglutide on cardiovascular risk factors, in patients with type 2 diabetes are also promising and the results from prospective studies to assess cardiovascular outcomes are eagerly awaited. Topics: Animals; Blood Glucose; Cardiovascular Diseases; Diabetes Mellitus, Type 2; Diabetic Angiopathies; Dipeptidyl-Peptidase IV Inhibitors; Endothelial Cells; Endothelium, Vascular; Exenatide; Glucagon-Like Peptide 1; Humans; Incretins; Liraglutide; Mice; Peptides; Prospective Studies; Risk Factors; Treatment Outcome; Venoms | 2012 |
Early diagnosis of pancreatic adenocarcinoma: role of stroma, surface proteases, and glucose-homeostatic agents.
New-onset diabetes in pancreatic adenocarcinoma is due to a combination of insulin resistance and decreased β-cell function. Its differentiation from the common type 2 diabetes is the prerequisite for early diagnosis of pancreatic adenocarcinoma. Little attention has been paid to pancreatic stroma and surface proteases.. The activated fibroblasts selectively express fibroblast activation protein α, a structural homolog of the ubiquitously expressed dipeptidyl peptidase 4. Their role in pancreatic carcinogenesis is reviewed.. Homodimers and heterodimers of both enzymes display high specificity for peptides and proteins with penultimate proline or alanine. Most glucose-homeostatic agents are candidate substrates of these enzymes. The biological activity of truncated substrates is decreased or absent.. The interactions of surface proteases with glucose-homeostatic agents may adequately explain the evolution of diabetes associated with pancreatic adenocarcinoma and differentiate it from the common type 2 diabetes. Topics: Adenocarcinoma; Diabetes Mellitus, Type 2; Dipeptidyl Peptidase 4; Early Diagnosis; Endopeptidases; Gelatinases; Glucagon-Like Peptide 1; Glucose; Humans; Insulin-Secreting Cells; Membrane Proteins; Pancreatic Neoplasms; Serine Endopeptidases | 2012 |
Optogenetic therapeutic cell implants.
Topics: Animals; Blood Glucose; Cell Transplantation; Diabetes Mellitus, Type 2; Glucagon-Like Peptide 1; Humans; Implants, Experimental; Light; Metabolic Engineering; Mice; Photoreceptor Cells; Phototherapy; Rod Opsins; Signal Transduction; Synthetic Biology | 2012 |
A comparison of currently available GLP-1 receptor agonists for the treatment of type 2 diabetes.
Glucagon-like peptide-1 (GLP-1) receptor agonists are a valuable addition to the type 2 diabetes armamentarium. They increase insulin secretion and reduce glucagon secretion in a glucose-dependent manner, posing a relatively low hypoglycemia risk. GLP-1 receptor agonists also offer weight-loss benefits. Because GLP-1 receptor agonists are relatively new agents, there is limited direction on their use.. This article aims to provide guidance to physicians when considering GLP-1 receptor agonist use in individual patients. It examines the clinical profiles of the currently available GLP-1 receptor agonists: exenatide twice-daily (BID), liraglutide once daily and exenatide extended release (ER) once weekly. Phase III clinical trial data on efficacy, safety and patient satisfaction are compared, with a primary focus on head-to-head trials.. Liraglutide seems to be the most effective GLP-1 receptor agonist in terms of HbA(1c) reduction and weight loss. Exenatide BID may offer an advantage where postprandial glucose control is a primary concern. Exenatide ER generally outperforms exenatide BID and is a good option for patients who struggle to adhere to more frequent regimens. The future may hold interesting developments in terms of reduced dosing frequency, oral formulations and alternative therapeutic uses. Topics: Animals; Diabetes Mellitus, Type 2; Exenatide; Glucagon-Like Peptide 1; Glucagon-Like Peptide-1 Receptor; Humans; Hypoglycemic Agents; Liraglutide; Peptides; Receptors, Glucagon; Venoms | 2012 |
Insulin sensitivity and secretion modifications after bariatric surgery.
Type 2 diabetes mellitus is increasing over time as result of the obesity epidemics. In fact, the prevalence of Type 2 diabetes across Europe in 2010 was estimated to be 8.2% of the population and its projection for 2030 sees figures of 10.1%. This increase in the number of diabetic individuals has also dramatically raised the health expense, with spending on diabetes in Europe in 2010 accounting for 10% of the total healthcare cost. A meta-analysis of the literature evidenced that the clinical and laboratory manifestations of Type 2 diabetes are resolved in 78.1%, and are improved in 86.6% of obese patients (body mass index >35 kg/m²) after bariatric surgery. However, a gradation of effects of different surgical techniques in improving glucose control does exist, with the largest and durable effects observed in prevalently malabsorptive procedures. The outcome of bariatric surgery on insulin sensitivity and secretion is different in relation to the type of operation performed. In fact, while Roux-en-Y Gastric Bypass enhances insulin secretion after a meal thus improving glucose metabolism, Bilio-Pancreatic Diversion acts through the amelioration of insulin sensitivity allowing a subsequent reduction of insulin hypersecretion, which is a typical feature of the insulin resistance state. Gastric banding action is mediated uniquely through the weight loss, and the effect of sleeve gastrectomy is still to be elucidated. Incretin secretion is dramatically increased under nutrient stimulation after gastric bypass leading, probably, to an overstimulation of pancreatic β-cells resulting in the increase of insulin secretion. Topics: Animals; Bariatric Surgery; Body Mass Index; Diabetes Mellitus, Type 2; Gastric Mucosa; Ghrelin; Glucagon; Glucagon-Like Peptide 1; Glucagon-Secreting Cells; Humans; Incretins; Insulin Resistance; Insulin-Secreting Cells; Intestinal Mucosa; Obesity, Morbid | 2012 |
The role of self-monitoring of blood glucose in glucagon-like peptide-1-based treatment approaches: a European expert recommendation.
The role of glucagon-like peptide (GLP)-1-based treatment approaches for type 2 diabetes mellitus (T2DM) is increasing. Although self-monitoring of blood glucose (SMBG) has been performed in numerous studies on GLP-1 analogs and dipeptidyl peptidase-4 inhibitors, the potential role of SMBG in GLP-1-based treatment strategies has not been elaborated. The expert recommendation suggests individualized SMBG strategies in GLP-1-based treatment approaches and suggests simple and clinically applicable SMBG schemes. Potential benefits of SMBG in GLP-1-based treatment approaches are early assessment of treatment success or failure, timely modification of treatment, detection of hypoglycemic episodes, assessment of glucose excursions, and support of diabetes management and diabetes education. Its length and frequency should depend on the clinical setting and the quality of metabolic control. It is considered to play an important role for the optimization of diabetes management in T2DM patients treated with GLP-1-based approaches. Topics: Biomarkers; Blood Glucose; Blood Glucose Self-Monitoring; Diabetes Mellitus, Type 2; Dipeptidyl-Peptidase IV Inhibitors; Drug Therapy, Combination; Europe; Glucagon-Like Peptide 1; Humans; Hypoglycemia; Hypoglycemic Agents; Incretins; Practice Guidelines as Topic; Predictive Value of Tests; Time Factors; Treatment Outcome | 2012 |
Insulin and GLP-1 analog combinations in type 2 diabetes mellitus: a critical review.
Glucagon-like peptide-1 (GLP-1) receptor agonists have been used in clinical management of type 2 diabetes since 2005. Currently approved agents were initially developed and approved for combination therapy with oral antidiabetic drugs (OADs). The potential for combined use with insulin has garnered increasing attention due to the potential to reduce side effects associated with insulin therapy and improve glycemic control.. We reviewed published and other publicly released data from controlled and uncontrolled studies that included subjects treated with insulin/GLP-1 analog combination therapy. The currently available guidance for clinical practice when combining insulin and GLP-1 analogs was also summarized.. Limited data currently available from placebo-controlled trials support the use of exenatide twice daily or liraglutide once daily in combination with basal insulin and metformin in subjects with type 2 diabetes unable to attain treatment goals. Several randomized controlled trials are currently studying combinations of insulin with various GLP-1 analogs. Additional guidance on the clinical use of these combinations will likely be forthcoming once these studies are reported. Insulin/GLP-1 analog combinations will require optimization of blood glucose monitoring strategies and delivery systems to decrease the risk of administration errors and reduce the potential complexity of these regimens. Topics: Diabetes Mellitus, Type 2; Drug Combinations; Glucagon-Like Peptide 1; Humans; Hypoglycemic Agents; Insulin | 2012 |
Recent advances in incretin-based therapies.
The global burden of type 2 diabetes is growing. Traditional therapies are suboptimal and there is a clear unmet need for treatments that offer effective glucose control while addressing the comorbid factors associated with diabetes, such as obesity and risk of cardiovascular disease, without the fear of hypoglycaemia. Glucagon-like peptide-1 receptor agonists and dipeptidyl peptidase-4 inhibitors offer a novel way of reducing hyperglycaemia by targeting the incretin system. This review provides an overview of the development of incretin-based therapies and explains their differing modes of action compared with traditional interventions. A comparison of the clinical profiles of current glucagon-like peptide-1 receptor agonists [liraglutide and exenatide (twice-daily and once-weekly)] and dipeptidyl peptidase-4 inhibitors (sitagliptin, saxagliptin, vildagliptin and linagliptin) is performed alongside a discussion of the placement of incretin-based therapies in treatment guidelines. Further improvements in this class are expected, and we will examine some of the novel glucagon-like peptide-1 receptor agonists and dipeptidyl peptidase-4 inhibitors currently under development. Topics: Animals; Diabetes Mellitus, Type 2; Dipeptidyl-Peptidase IV Inhibitors; Exenatide; Glucagon-Like Peptide 1; Glucagon-Like Peptide-1 Receptor; Humans; Hypoglycemic Agents; Incretins; Liraglutide; Peptides; Receptors, Glucagon; Venoms | 2012 |
Cardiac protection via metabolic modulation: an emerging role for incretin-based therapies?
Cardiovascular disease continues to be a major cause of morbidity and mortality in patients with Type 2 Diabetes Mellitus. Whilst a focus on improved glucose control and HbA1c has led to a reduction in the progression and development of microvascular complications, the potential for this strategy to reduce cardiovascular event rates is less clearly defined. Identification of the incretin axis has facilitated the development of several novel therapeutic agents which target glucagon-like peptide-1 (GLP-1) pathways. The effects on glucose homeostasis are now established, but there is also now an increasing body of evidence to support a number of pleiotropic effects on the heart that may have the potential to influence cardiovascular outcomes. In this article, we review myocardial energy metabolism with particular emphasis on the potential benefits associated with a shift towards increased glucose utilisation and present the pre-clinical and clinical evidence regarding incretin effects on the heart. In addition we discuss the potential mechanism of action and benefit of drugs that modulate GLP-1 in patients with type 2 diabetes mellitus and coronary artery disease. Topics: Animals; Cardiotonic Agents; Cardiovascular Diseases; Diabetes Mellitus, Type 2; Energy Metabolism; Glucagon-Like Peptide 1; Humans; Incretins; Myocardium | 2012 |
Incretins and preservation of endothelial function.
The endothelium is critical for multiple processes occurring on both sides of the vascular wall including regulation of blood flow, maintenance of blood fluidity and control of inflammation. Endothelial dysfunction is an early event in the pathogenesis of atherosclerosis and appears to be a critical determinant of cardiovascular events. It is frequently detected in the early stages of type 2 diabetes and even in pre-diabetes conditions. Risk factors for endothelial dysfunction are numerous and include among others fasting and postprandial hyperglycemia and hyperlipidemia, hypertension, obesity, insulin resistance and inflammation. Many of these conditions can be improved by synthetic glucagon like peptide 1 (GLP-1) mimetics or inhibitors of the main GLP-1 degrading enzyme dipeptidyl peptidase 4 (DPP-4). Acute increases in GLP-1 activity abolish endothelial dysfunction induced by high-fat meals or by hyperglycemia. In vitro and preliminary clinical studies also indicate that GLP-1 or GLP-1 agonists can improve endothelial function by direct action on endothelium. GLP-1 or GLP-1 mimetic effects appear to extend to both conduit arteries and the microvasculature, and may depend on activation of endothelial GLP-1 receptors and downstream nitric oxide production. Additional studies are necessary to confirm improvement of endothelial function after prolonged treatment with incretin based medications as well as the cardiovascular benefit of these agents. Topics: Animals; Diabetes Mellitus, Type 2; Dipeptidyl-Peptidase IV Inhibitors; Endothelium, Vascular; Glucagon-Like Peptide 1; Humans; Hypoglycemic Agents; Incretins; Insulin Resistance; Nitric Oxide Synthase Type III | 2012 |
An update in incretin-based therapy: a focus on glucagon-like peptide-1 receptor agonists.
The glucagon-like peptide-1 receptor agonists, exenatide and liraglutide, offer a unique mechanism in the treatment of type 2 diabetes mellitus (T2DM) as part of the incretin system. Their mechanism of action is to increase insulin secretion, decrease glucagon release, reduce food intake, and slow gastric emptying. They target postprandial blood glucose values and have some effect on fasting levels as well. In addition, they promote weight loss and may help to preserve β-cell function, both major problems in T2DM patients. Changes in hemoglobin A1c are similar to those produced by other T2DM agents, including thiazolidinediones, low-dose metformin, and sulfonylureas, and better than those caused by α-reductase inhibitors and dipeptidyl peptidase-4 inhibitors. These agents have been safely studied in combination with metformin, sulfonylureas, meglitinides, thiazolidinediones, and insulin therapy. Overall, data are limited for head-to-head comparisons, but it appears that liraglutide may have better efficacy and tolerability compared with exenatide; however, more studies are needed. They are overall well tolerated, with the main adverse events being similar to those with metformin (gastrointestinal intolerances that are transient and dose dependent). However, patients must be monitored for pancreatitis as a rare but possible side effect. For T2DM patients willing to use an injectable agent, exenatide and liraglutide offer another therapeutic option to control hyperglycemia with the potential for weight loss and may be combined with other agents safely. Topics: Blood Glucose; Diabetes Mellitus, Type 2; Drug Therapy, Combination; Exenatide; Female; Glucagon-Like Peptide 1; Glucagon-Like Peptide-1 Receptor; Glycated Hemoglobin; Humans; Hypoglycemic Agents; Liraglutide; Male; Peptides; Receptors, Glucagon; Treatment Outcome; Venoms | 2012 |
Novel role for the incretins in blood pressure regulation.
Incretin-based therapies are currently being used in the treatment of type 2 diabetes mellitus (T2DM). Apart from glycemic control, these agents have been shown to have multiple extra-pancreatic effects, including their role in blood pressure (BP) regulation. This article will review the origins of incretins, the incretin axis, possible mechanisms of antihypertensive effect of these agents, as well as the recent evidence.. Preclinical and clinical studies demonstrate the antihypertensive effects of glucagon-like peptide-1 (GLP-1) and its analogs in patients with T2DM and hypertension. This effect seems to be mediated through vasodilatation as well as modulation of renal sodium handling causing natriuresis, although the exact mechanisms are not fully known.. Incretin-based therapies are emerging as a novel class of hypoglycemic agents that display antihypertensive properties. Given the small decreases in BP, it is unlikely that these agents will be used as stand-alone antihypertensive agents, but they may be an attractive option in patients with T2DM and hypertension. Topics: Antihypertensive Agents; Blood Pressure; Diabetes Mellitus, Type 2; Glucagon-Like Peptide 1; Humans; Hypertension; Incretins | 2012 |
Glucagon-like peptide-1 and its cardiovascular effects.
Recently, the crucial role of GLP-1 in cardiovascular disease has been suggested by both preclinical and clinical studies. In vivo and in vitro studies have demonstrated cardio-protective effects of GLP-1 by activating cell survival signal pathways, which have greatly reduced ischemia/reperfusion injury and also cardiac dysfunction in various congestive heart failure animal models. Clinically, beneficial effects of GLP-1 have been shown in patients with myocardial infarction, hypertension, and heart failure, and 2 classes of incretin enhancers, GLP-1 receptor agonists and DPP-4 inhibitors, are currently available for the treatment of type 2 diabetes mellitus. In this review, we will summarize the role of incretins in various cardiovascular events such as hypertension and heart failure and postprandial lipoprotein secretion, and discuss their molecular mechanisms and potentials as a new therapeutic as well as preventive drug type for reducing cardiovascular events in both diabetic and nondiabetic patients. Topics: Animals; Cardiovascular Diseases; Diabetes Mellitus, Type 2; Dipeptidyl Peptidase 4; Glucagon-Like Peptide 1; Glucagon-Like Peptide-1 Receptor; Humans; Incretins; Receptors, Glucagon | 2012 |
Treatment evaluation of liraglutide in type 2 diabetes.
Liraglutide is a Glucagon like Peptide-1 (GLP-1) receptor agonist, which stimulates GLP-1 receptors and consequently leads to various cardio-metabolic and glycemic improvements in individuals with Type 2 Diabetes Mellitus (T2DM). It is administered once daily as a subcutaneous injection and has been extensively studied in randomized placebo and active comparator studies demonstrating favorable effects on glycemic control and weight reduction. This short review summarizes the role and practical use of this agent in the context of efficacy and safety information obtained during clinical trials. Topics: Animals; Blood Glucose; Clinical Trials as Topic; Diabetes Mellitus, Type 2; Drug Evaluation; Glucagon-Like Peptide 1; Glucagon-Like Peptide-1 Receptor; Humans; Hypoglycemic Agents; Liraglutide; Receptors, Glucagon; Treatment Outcome | 2012 |
The gut endocrine system as a coordinator of postprandial nutrient homoeostasis.
Hormones from the gastrointestinal (GI) tract are released following food ingestion and trigger a range of physiological responses including the coordination of appetite and glucose homoeostasis. The aim of this review is to discuss the pathways by which food ingestion triggers secretion of cholecystokinin (CCK), glucose-dependent insulinotropic polypeptide (GIP) and glucagon-like peptide-1 (GLP-1) and the altered patterns of gut hormone release observed following gastric bypass surgery. Our understanding of how ingested nutrients trigger secretion of these gut hormones has increased dramatically, as a result of physiological studies in human subjects and animal models and in vitro studies on cell lines and primary intestinal cultures. Specialised enteroendocrine cells located within the gut epithelium are capable of directly detecting a range of nutrient stimuli through a range of receptors and transporters. It is concluded that the arrival of nutrients at the apical surface of enteroendocrine cells is a major stimulus for gut hormone release, thereby coupling these endocrine signals to the arrival of absorbed nutrients in the bloodstream. Topics: Animals; Cholecystokinin; Diabetes Mellitus, Type 2; Eating; Enteroendocrine Cells; Gastrointestinal Tract; Glucagon-Like Peptide 1; Homeostasis; Humans; Obesity; Postprandial Period; Receptors, Gastrointestinal Hormone; Signal Transduction | 2012 |
Impairment of GLP1-induced insulin secretion: role of genetic background, insulin resistance and hyperglycaemia.
One major risk factor of type 2 diabetes is the impairment of glucose-induced insulin secretion which is mediated by the individual genetic background and environmental factors. In addition to impairment of glucose-induced insulin secretion, impaired glucagon-like peptide (GLP)1-induced insulin secretion has been identified to be present in subjects with diabetes and impaired glucose tolerance, but little is known about its fundamental mechanisms. The state of GLP1 resistance is probably an important mechanism explaining the reduced incretin effect observed in type 2 diabetes. In this review, we address methods that can be used for the measurement of insulin secretion in response to GLP1 in humans, and studies showing that specific diabetes risk genes are associated with resistance of the secretory function of the β-cell in response to GLP1 administration. Furthermore, we discuss other factors that are associated with impaired GLP1-induced insulin secretion, for example, insulin resistance. Finally, we provide evidence that hyperglycaemia per se, the genetic background and their interaction result in the development of GLP1 resistance of the β-cell. We speculate that the response or the non-response to therapy with GLP1 analogues and/or dipeptidyl peptidase-4 (DPP-IV) inhibitors is critically dependent on GLP1 resistance. Topics: Diabetes Mellitus, Type 2; Dipeptidyl Peptidase 4; Dipeptidyl-Peptidase IV Inhibitors; Disease Progression; Female; Glucagon-Like Peptide 1; Humans; Hyperglycemia; Hypoglycemic Agents; Insulin; Insulin Resistance; Insulin Secretion; Male | 2012 |
GLP-1 receptor agonists for individualized treatment of type 2 diabetes mellitus.
In healthy humans, the incretin glucagon-like peptide 1 (GLP-1) is secreted after eating and lowers glucose concentrations by augmenting insulin secretion and suppressing glucagon release. Additional effects of GLP-1 include retardation of gastric emptying, suppression of appetite and, potentially, inhibition of β-cell apoptosis. Native GLP-1 is degraded within ~2-3 min in the circulation; various GLP-1 receptor agonists have, therefore, been developed to provide prolonged in vivo actions. These GLP-1 receptor agonists can be categorized as either short-acting compounds, which provide short-lived receptor activation (such as exenatide and lixisenatide) or as long-acting compounds (for example albiglutide, dulaglutide, exenatide long-acting release, and liraglutide), which activate the GLP-1 receptor continuously at their recommended dose. The pharmacokinetic differences between these drugs lead to important differences in their pharmacodynamic profiles. The short-acting GLP-1 receptor agonists primarily lower postprandial blood glucose levels through inhibition of gastric emptying, whereas the long-acting compounds have a stronger effect on fasting glucose levels, which is mediated predominantly through their insulinotropic and glucagonostatic actions. The adverse effect profiles of these compounds also differ. The individual properties of the various GLP-1 receptor agonists might enable incretin-based treatment of type 2 diabetes mellitus to be tailored to the needs of each patient. Topics: Amino Acid Sequence; Animals; Blood Glucose; Diabetes Mellitus, Type 2; Exenatide; Glucagon-Like Peptide 1; Humans; Hypoglycemic Agents; Liraglutide; Molecular Sequence Data; Peptides; Precision Medicine; Protein Structure, Secondary; Treatment Outcome; Venoms | 2012 |
Renal and cardiac effects of DPP4 inhibitors--from preclinical development to clinical research.
Inhibitors of type 4 dipeptidyl peptidase (DDP-4) were developed and approved for the oral treatment of type 2 diabetes. Its mode of action is to inhibit the degradation of incretins, such as type 1 glucagon like peptide (GLP-1), and GIP. GLP-1 stimulates glucose-dependent insulin secretion from pancreatic beta-cells and suppresses glucagon release from alpha-cells, thereby improving glucose control. Besides its action on the pancreas type 1 glucagon like peptide has direct effects on the heart, vessels and kidney mainly via the type 1 glucagon like peptide receptor (GLP-1R). Moreover, there are substrates of DPP-4 beyond incretins that have proven renal and cardiovascular effects such as BNP/ANP, NPY, PYY or SDF-1 alpha. Preclinical evidence suggests that DPP-4 inhibitors may be effective in acute and chronic renal failure as well as in cardiac diseases like myocardial infarction and heart failure. Interestingly, large cardiovascular meta-analyses of combined phase II/III clinical trials with DPP-4 inhibitors point all in the same direction: a potential reduction of cardiovascular events in patients treated with these agents. A pooled analysis of pivotal phase III, placebo-controlled, registration studies of linagliptin further showed a significant reduction of urinary albumin excretion after 24 weeks of treatment. The observation suggests direct renoprotective effects of DPP-4 inhibition that may go beyond its glucose-lowering potential. Type 4 dipeptidyl peptidase inhibitors have been shown to be very well tolerated in general, but for those excreted via the kidney dose adjustments according to renal function are needed to avoid side effects. In conclusion, the direct cardiac and renal effects seen in preclinical studies as well as meta-analysis of clinical trials may offer additional potentials - beyond improvement of glycemic control - for this newer class of drugs, such as acute kidney failure, chronic kidney failure as well as acute myocardial infarction and heart failure. Topics: Biomedical Research; Blood Glucose; Clinical Trials, Phase III as Topic; Diabetes Mellitus, Type 2; Dipeptidyl Peptidase 4; Drug Evaluation, Preclinical; Enzyme Inhibitors; Glucagon-Like Peptide 1; Heart; Humans; Kidney | 2012 |
A meta-analysis of serious adverse events reported with exenatide and liraglutide: acute pancreatitis and cancer.
The association between GLP-1 agonists, acute pancreatitis (AP), any cancer and thyroid cancer is discussed. This meta-analysis was aimed at evaluating the risk of those serious adverse events associated with GLP-1 agonists in patients with type 2 diabetes.. Medline, EMBASE, Cochrane Library and clinicaltrials.gov were searched in order to identify longitudinal studies evaluating exenatide or liraglutide use and reporting data on AP or cancer. Odds ratios (ORs) were pooled using a random-effects model. I(2) statistics assessed heterogeneity.. Twenty-five studies were included. Neither exenatide (OR 0.84 [95% CI 0.58-1.22], I(2) = 30%) nor liraglutide (OR 0.97 [95% CI 0.21-4.39], I(2) = 0%) were associated with an increased risk of AP, independent of baseline comparator. The pooled OR for cancer associated with exenatide was 0.86 (95% CI 0.29, 2.60, I(2) = 0%) and for liraglutide was 1.35 (95% CI 0.70, 2.59, I(2) = 0%). Liraglutide was not associated with an increased risk for thyroid cancer (OR 1.54 [95% CI 0.40-6.02], I(2) = 0%). For exenatide, no thyroid malignancies were reported.. Current available published evidence is insufficient to support an increased risk of AP or cancer associated with GLP-1 agonists. These rare and long-term adverse events deserve properly monitoring in future studies evaluating GLP-1 agonists. Topics: Diabetes Mellitus, Type 2; Exenatide; Glucagon-Like Peptide 1; Humans; Hypoglycemic Agents; Liraglutide; Neoplasms; Pancreatitis; Peptides; Venoms | 2012 |
Glucagon-like peptide 1 and cardiac cell survival.
During myocardial infarction (MI), a variety of mechanisms contribute to activation of cell death processes in cardiomyocytes, which determines the final MI size, subsequent mortality, and post-MI remodeling. The deleterious mechanisms activated during the ischemia and reperfusion phases in MI include oxygen deprival, decreased availability of nutrients and survival factors, accumulation of waste products, generation of oxygen free radicals, calcium overload, neutrophil infiltration in the ischemic area, depletion of energy stores, and opening of the mitochondrial permeability transition pore, all of them contributing to activation of apoptosis and necrosis in cardiomyocytes. Glucagon-like peptide-1 [GLP-1 (7-36) amide] has gained relevance in recent years for metabolic treatment of patients with type 2 diabetes mellitus. Cytoprotection of different cell types, including cardiomyocytes, is among the pleiotropic actions reported for GLP-1. This paper reviews the most relevant experimental studies that have contributed to a better understanding of the molecular mechanisms and intracellular pathways involved in cardioprotection induced by GLP-1 and analyzes in depth its potential role as a therapeutic target both in the ischemic and reperfused myocardium and in other conditions that are associated with myocardial remodeling and heart failure. Topics: Animals; Cardiotonic Agents; Cell Survival; Cells, Cultured; Diabetes Mellitus, Type 2; Dipeptidyl Peptidase 4; Dipeptidyl-Peptidase IV Inhibitors; Drug Evaluation, Preclinical; Enteroendocrine Cells; Enzyme Activation; Glucagon-Like Peptide 1; Heart Failure; Heart Function Tests; Humans; Hypoglycemic Agents; Myocardial Ischemia; Myocardial Reperfusion Injury; Myocytes, Cardiac; Peptide Fragments; Protein Kinases; Signal Transduction | 2012 |
New avenues for the pharmacological management of type 2 diabetes: an update.
Type 2 diabetes mellitus (T2DM) is one of the most troubling chronic disease regarding the huge number of new cases diagnosed annually worldwide. Currently available oral antidiabetic drugs (OADs) attempt to correct the underlying pathophysiological dysfunctions leading to T2DM: insulin resistance for the insulin sensitizers (metformin and thiazolidinediones), and impaired insulin secretion for the insulin secretagogues (sulfonylureas, glinides and more recently incretin mimetics). Incretin-based therapies include GLP-1 receptor agonists that provide pharmacologic levels of GLP-1 receptor stimulation beyond those that would occur from the action of the native hormone alone, and dipeptidyl-peptidase-4 (DPP-4) inhibitors that preserve endogenous GLP-1 by decreasing its degradation by the DPP-4 enzyme. In 2012, the development of new OADs aims to target untapped pathophysiological aspects of the disease (kidney homeostasis, glucagon signalling, chronic low-grade inflammation) for tailoring glycaemic control in T2DM. SGLT-2 inhibitors are the most advanced new OADs that lower HbA1C by increasing glycosuria and lead to a moderate weight loss. Although there is genuine hope that the range of OADs can be extended, a long-term evaluation of side effects and true clinical benefits is necessary. Topics: Anti-Inflammatory Agents; Diabetes Mellitus, Type 2; Dipeptidyl-Peptidase IV Inhibitors; Glucagon-Like Peptide 1; Glucagon-Like Peptide-1 Receptor; Glycated Hemoglobin; Glycosuria; Humans; Hypoglycemic Agents; Incretins; Insulin Resistance; Receptors, G-Protein-Coupled; Receptors, Glucagon; Sodium-Glucose Transporter 2; Sodium-Glucose Transporter 2 Inhibitors; Sulfonylurea Compounds; Thiazolidinediones | 2012 |
[Liraglutide: new results in the treatment of type 2 diabetes mellitus].
New drugs for type 2 diabetes that act on incretin metabolism have been shown to improve glycemic control, reduce body weight and have a low risk for hypoglycemia. Among these, liraglutide is the first glucagon-like peptide 1 (GLP-1) analogue approved for subcutaneous, once-daily administration. According to results from clinical trials, liraglutide is an attractive alternative for the early treatment of type 2 diabetes. The results of the LEAD (Liraglutide Effect and Action in Diabetes) study program demonstrated the efficacy and safety of liraglutide in terms of reduction of glycated hemoglobin (HbA1c) levels, significant loss of body weight that was maintained over the long term, better control of the lipid profile and systolic arterial pressure, reduction of the risk for hypoglycemia and reduction of cardiovascular risk. Moreover, the drug was demonstrated to be safe and can be co-administered with oral antidiabetic agents. The product's tolerability has been demonstrated, with nausea as the most common adverse event, which waned from the fourth week of treatment. Topics: Blood Glucose; Diabetes Mellitus, Type 2; Dose-Response Relationship, Drug; Drug Therapy, Combination; Glucagon-Like Peptide 1; Glycated Hemoglobin; Humans; Hypoglycemic Agents; Incretins; Liraglutide; Pyrazines; Sitagliptin Phosphate; Sulfonylurea Compounds; Triazoles | 2012 |
Pancreatitis: a potential complication of liraglutide?
To review the evidence surrounding a potential association between liraglutide and pancreatitis.. A literature search was conducted in MEDLINE (1948-July 12, 2012) and EMBASE (1974-week 27, 2012) using the search terms pancreatitis, liraglutide, and glucagon-like peptide 1/adverse effects. Reference citations from identified publications were reviewed. The manufacturer was contacted and regulatory documents from the Food and Drug Administration website were reviewed for unpublished data related to cases of pancreatitis associated with liraglutide use.. All identified sources that were published in English were considered for inclusion.. Eleven cases of pancreatitis have been reported in patients taking liraglutide. Seven were from the LEAD (Liraglutide Effect and Action in Diabetes) studies, 1 was reported in the extension of a clinical trial, and 1 was in an unpublished obesity trial. Two were published postmarketing case reports. Nine of the cases reported were diagnosed as acute pancreatitis, while 2 were classified as chronic pancreatitis. The mean age of the patients was 57.5 years and mean body mass index was 33.92 kg/m(2). Six of the 11 cases occurred in male patients. Nine of the patients were white and 1 was African American. In 7 of the cases, onset occurred at liraglutide doses at or above 1.8 mg daily. Common comorbidities included history of pancreatitis, cholelithiasis, and diabetes. One case was fatal.. Pancreatitis is a potential complication with liraglutide therapy. Liraglutide should be used cautiously in patients at risk of pancreatitis (eg, alcohol abuse, history of pancreatitis, cholelithiasis). Topics: Diabetes Mellitus, Type 2; Glucagon-Like Peptide 1; Humans; Hypoglycemic Agents; Liraglutide; Pancreatitis | 2012 |
Mechanisms of current therapies for diabetes mellitus type 2.
The array of medications available for the treatment of hyperglycemia has increased rapidly in the previous decade, and recent investigations have clarified novel mechanisms underlying the antihyperglycemic efficacy of these drugs. This article reviews the mechanisms of action for medications currently approved to treat diabetes mellitus in the United States, with the exception of insulin and its analogs. Finally, it attempts to integrate these mechanisms into the schema of pathophysiological factors that combine to produce hyperglycemia in patients with diabetes mellitus. Topics: Animals; Blood Glucose; Diabetes Mellitus, Type 2; Dipeptidyl-Peptidase IV Inhibitors; Glucagon-Like Peptide 1; Humans; Hypoglycemic Agents; Insulin; Islet Amyloid Polypeptide; Randomized Controlled Trials as Topic | 2012 |
The combination of insulin and GLP-1 analogues in the treatment of type 2 diabetes.
GLP-1 analogues have been proven to be effective in the treatment of type 2 diabetes mellitus. They stimulate insulin production and secretion, and suppress glucagon secretion, depending on the blood glucose level. They also have an effect on the brain, enhancing satiety, and on the gut, where they delay gastric emptying. Theoretically, in type 2 diabetes mellitus patients, the combination of a GLP-1 analogue with insulin seems attractive, because of the weight loss perceived in users of GLP-1 analogues in contrast to the weight gain seen in most patients starting insulin therapy, leading to even more insulin resistance. There are only a few randomised controlled trials which have studied this combination and several uncontrolled studies, which will be reviewed here. Topics: Blood Glucose; Diabetes Mellitus, Type 2; Drug Therapy, Combination; Glucagon; Glucagon-Like Peptide 1; Humans; Insulin; Insulin Resistance; Treatment Outcome | 2012 |
[Combination therapy with glucagon-like peptide-1 analogs and insulin: indications and contraindications in coronary artery disease patients].
Type 2 diabetes mellitus is a progressive disease characterized by an impairment of insulin action, and failure of pancreatic β-cells to compensate for the enhanced insulin demand. Owing to the progressive nature of the disease, many individuals require insulin replacement therapy to maintain glycemic control. Intensification of treatment in these circumstances usually results in weight gain and increased risk of hypoglycemia, two undesirable events that are associated with a worse cardiovascular risk profile and decreased adherence to treatment. The introduction of glucagon-like peptide-1 (GLP-1) analogs (exenatide and liraglutide) into the diabetes market offers a new therapeutic approach to the treatment of type 2 diabetes. GLP-1 analogs increase insulin secretion and inhibit glucagon secretion in a glucose-dependent manner, thus conferring glycemic control with a low risk of hypoglycemia. GLP-1 analogs also promote weight loss, and have beneficial effects on blood pressure and cardiovascular risk markers. The combination of GLP-1 analogs and insulin might be highly effective to maintain glucose control, and to attenuate the adverse effects usually associated with insulin therapy. Data from both retrospective and prospective clinical studies support the therapeutic potential of the combination of GLP-1 analogs and insulin, usually showing beneficial effects on glycemic control associated with reduced weight gain, low incidence of hypoglycemia and, in established insulin therapy, reduction in insulin dose. In this review, the pathophysiological rationale for using the combination of GLP-1 analogs is discussed, and data from clinical studies that have evaluated the efficacy of this treatment strategy are summarized. Topics: Contraindications; Coronary Artery Disease; Diabetes Mellitus, Type 2; Diabetic Angiopathies; Drug Therapy, Combination; Glucagon-Like Peptide 1; Humans; Insulin | 2012 |
Second line therapy: type 2 diabetic subjects failing on metformin GLP-1/DPP-IV inhibitors versus sulphonylurea/insulin: for GLP-1/DPP-IV inhibitors.
Following diagnosis, type 2 diabetic subjects are invariably treated with life style modifications and metformin. However, majority of these subjects require addition of another therapeutic agent singly or in combination; with or without insulin within few months to few years. For several decades, sulphonylureas and insulin have been the second line agent of choice. Clinical practice guidelines also suggest a similar approach. Subsequently thiazolidinediones, alpha glucose inhibitors and other agents were added to therapeutic armamentarium. Unfortunately, none of these treatment options could address the issue of progressive decline in beta cell function. Furthermore, they are responsible for unacceptable incidence of hypoglycaemia, weight gain and other side effects related to individual agents. Type 2 diabetic subjects have great propensity to develop cardiovascular complications. Sulphonylureas, insulin and thiazolidinediones have all been associated with adverse cardiovascular outcomes in differing magnitude. It has been made mandatory by regulatory agencies to ensure cardiovascular safety of any new anti-diabetic agent. Glucagon Like Peptide-1(GLP-1)-based therapies have been able to address several of these issues. Incretin mimetics and Di Peptidyl Dipeptidase IV (DPP-IV) inhibitors cause glucose-dependent insulin secretion and glucagon suppression from beta and alpha cells of the pancreas respectively. They owe this property to their binding with G-Protein-coupled receptors leading to an increased amount of c-AMP. They do not cause beta cell exhaustion. On the contrary such agents prevent beta cell apoptosis. Clinical trials have established the superiority of incretin mimetics particularly liraglutide against comparators including glimepiride, rosiglitazone and insulin Glargine in terms of efficacy. Furthermore, they have shown evidence towards beta cell protection, significant weight loss, minimal hypoglycaemia and favourable impact on surrogate markers of cardiovascular outcomes. DPP-IV inhibitors have limited ability to achieve glycaemic targets. However, they are weight neutral, cause minimal hypoglycaemia and have some beneficial effect on beta cell function. Finally, they are very well tolerated. Topics: Diabetes Mellitus, Type 2; Dipeptidyl-Peptidase IV Inhibitors; Glucagon-Like Peptide 1; Humans; Hypoglycemic Agents; Insulin; Metformin; Retreatment; Sulfonylurea Compounds; Treatment Failure | 2012 |
Diabetes therapy--focus on Asia: second-line therapy debate: insulin/secretagogues.
The following review is based on the second part of a debate entitled 'Diabetes therapy--focus on Asia: 2nd line therapy: GLP1/DPP4 inhibitors versus Secretagogue/insulin therapy', which was held during the '1st Asia Pacific Congress on Controversies to Consensus in Diabetes, Obesity and Hypertension (CODHy)', in Shanghai, China, 2011. As such we reviewed only insulin and secretagogue therapy despite the existence of other therapeutic options. The article aims to shed light on the circumstances most adequate for use of these as second-line agents, despite possible drawbacks. It is important to emphasize that regardless of it being a review of published evidence, it primarily represents the professional opinion of the writers. Topics: China; Diabetes Mellitus, Type 2; Dipeptidyl-Peptidase IV Inhibitors; Glucagon-Like Peptide 1; Humans; Hypoglycemic Agents; Insulin; Sulfonylurea Compounds | 2012 |
Oral delivery of glucagon-like peptide-1 and analogs: alternatives for diabetes control?
Type 2 diabetes mellitus (T2DM) is one of the most prevalent diseases worldwide. Current treatments are often associated with off-target effects and do not significantly impact disease progression. New therapies are therefore urgently needed to overcome this social burden. Glucagon-like peptide-1 (GLP-1), an incretin hormone, has been used to control T2DM symptomatology. However, the administration of peptide or proteins drugs is still a huge challenge in the pharmaceutical field, requiring administration by parenteral routes. This article reviews the main hurdles in oral administration of GLP-1 and focuses on the strategies utilized to overcome them. Topics: Administration, Oral; Animals; Diabetes Mellitus, Type 2; Glucagon-Like Peptide 1; Humans; Hypoglycemic Agents | 2012 |
Liraglutide in type 2 diabetes mellitus.
Liraglutide (victoza, Novo Nordisk A/S) is human GLP-1 analogue developed by recombinant DNA technology. It is indicated along with diet and exercise in management of type 2 diabetes (T2DM) in adults. Liraglutide has been made available in India recently. Present review evaluates the efficacy and safety of liraglutide in T2DM and its comparison with other incretin based therapies. Liraglutide has been evaluated as monotherapy, in combination with one, two and three oral antidiabetic drugs similarly to routine clinical practice. These studies reported greater improvement in glycaemic control with liraglutide compared with comparators. Evaluation up to 2 years revealed sustained improvement in glycaemic control with liraglutide use. Liraglutide was well tolerated except for mild to moderate gastro-intestinal adverse events, which declined after continuation of therapy. Low risk of hypoglycaemia was reported with liraglutide therapy. Greater efficacy than other incretin based therapies was noted with liraglutide. Liraglutide has an important place in the management of T2DM. Apart from glycaemic control it also provides some important non-glycaemic benefits in terms of improving beta-cell function, weight reduction, and reduction in systolic blood pressure thereby overcoming the present therapeutic gap. Topics: Diabetes Mellitus, Type 2; Exenatide; Glucagon-Like Peptide 1; Humans; Hypoglycemic Agents; Liraglutide; Peptides; Pyrazines; Sitagliptin Phosphate; Triazoles; Venoms | 2012 |
Impact of GLP-1 receptor agonists on major gastrointestinal disorders for type 2 diabetes mellitus: a mixed treatment comparison meta-analysis.
We aimed to integrate evidence from all randomized controlled trials (RCTs) and assess the impact of different doses of exenatide or liraglutide on major gastrointestinal adverse events (GIAEs) in type 2 diabetes (T2DM).. RCTs evaluating different doses of exenatide and liraglutide against placebo or an active comparator with treatment duration ≥4 weeks were searched and reviewed. A total of 35, 32 and 28 RCTs met the selection criteria evaluated for nausea, vomiting, and diarrhea, respectively. Pairwise random-effects meta-analyses and mixed treatment comparisons (MTC) of all RCTs were performed.. All GLP-1 dose groups significantly increased the probability of nausea, vomiting and diarrhea relative to placebo and conventional treatment. MTC meta-analysis showed that there was 99.2% and 85.0% probability, respectively, that people with exenatide 10 μg twice daily (EX10BID) was more vulnerable to nausea and vomiting than those with other treatments. There was a 78.90% probability that liraglutide 1.2 mg once daily (LIR1.2) has a higher risk of diarrhea than other groups. A dose-dependent relationship of exenatide and liraglutide on GIAEs was observed.. Our MTC meta-analysis suggests that patients should be warned about these GIAEs in early stage of treatment by GLP-1s, especially by EX10BID and LIR1.2, to promote treatment compliance. Topics: Diabetes Mellitus, Type 2; Diarrhea; Dose-Response Relationship, Drug; Drug Administration Schedule; Exenatide; Female; Gastrointestinal Diseases; Glucagon-Like Peptide 1; Glucagon-Like Peptide-1 Receptor; Humans; Hypoglycemic Agents; Liraglutide; Male; Middle Aged; Nausea; Odds Ratio; Peptides; Randomized Controlled Trials as Topic; Receptors, Glucagon; Risk Assessment; Risk Factors; Time Factors; Venoms; Vomiting | 2012 |
[Treatment of type 2 diabetes mellitus--which role do GLP-1 receptor agonists play?].
The results of the ACCORD-, ADVANCE- and VADT- and further recent studies raised doubts regarding whether the guidelined therapy of type 2 diabetes mellitus, which aims at achieving HbA1c values of < 6.5%, is always beneficial. The higher rate of severe hypoglycemia and weight gain under intensive glycemic control has raised debates of whether the current guidelines should be adopted accordingly. Modern state-of-the-art treatment should consider: a) early treatment start, b) sustained blood sugar decrease, and c) simultaneously prevention of hypoglycemia and weight gain, d) prevention of little investigated multiple glucose-lowering agents, e) easy handling and easy to be integrated into daily schedules. The present work reviews current options with regard to these requirements with special focus on the new GLP-1 receptor agonists. Topics: Blood Glucose; Clinical Trials as Topic; Combined Modality Therapy; Diabetes Mellitus, Type 2; Diet, Diabetic; Drug Therapy, Combination; Exenatide; Exercise; Germany; Glucagon-Like Peptide 1; Glucagon-Like Peptide-1 Receptor; Glycated Hemoglobin; Guideline Adherence; Humans; Hypoglycemic Agents; Insulin; Liraglutide; Metformin; Peptides; Receptors, Glucagon; Treatment Failure; Venoms | 2011 |
Secretion of glucagon-like peptide-1 (GLP-1) in type 2 diabetes: what is up, what is down?
The incretin hormones gastric inhibitory polypeptide and especially glucagon-like peptide (GLP) have an important physiological function in augmenting postprandial insulin secretion. Since GLP-1 may play a role in the pathophysiology and treatment of type 2 diabetes, assessment of meal-related GLP-1 secretory responses in type 2 diabetic patients vs healthy individuals is of great interest. A common view states that GLP-1 secretion in patients with type 2 diabetes is deficient and that this applies to a lesser degree in individuals with impaired glucose tolerance. Such a deficiency is the rationale for replacing endogenous incretins with GLP-1 receptor agonists or re-normalising active GLP-1 concentrations with dipeptidyl peptidase-4 inhibitors. This review summarises the literature on this topic, including a meta-analysis of published studies on GLP-1 secretion in individuals with and without diabetes after oral glucose and mixed meals. Our analysis does not support the contention of a generalised defect in nutrient-related GLP-1 secretory responses in type 2 diabetes patients. Rather, factors are identified that may determine individual incretin secretory responses and explain some of the variations in published findings of group differences in GLP-1 responses to nutrient intake. Topics: Animals; Diabetes Mellitus, Type 2; Glucagon-Like Peptide 1; Humans; Incretins; Meta-Analysis as Topic; Models, Biological | 2011 |
New treatments for type 2 diabetes in the UK - an evolving landscape.
New classes of treatments for type 2 diabetes have been developed recently and are now available in the UK. This review aims to summarise key clinical efficacy, tolerability and safety data for these agents, including liraglutide, which has received preliminary review by the National Institute for Clinical Excellence (NICE) and was launched in the UK in 2009. Topics: Diabetes Mellitus, Type 2; Dipeptidyl-Peptidase IV Inhibitors; Evidence-Based Medicine; Glucagon-Like Peptide 1; Humans; Hypoglycemic Agents; Incretins; Treatment Outcome; United Kingdom | 2011 |
Bariatric surgery: results in obesity and effects on metabolic parameters.
The use of bariatric surgery is increasing at an enormous rate in all countries but the indications for the operation on the basis of metabolic derangements are not clear as only one controlled randomized trial has been performed so far. Thus, it is not clear whether bariatric surgery should be performed on obese patients with long-standing type 2 diabetes or poorly controlled hypertension or hypertriglyceridemia. The mechanism for the immediate improvement in glucose tolerance after gastric bypass is not clear but is being actively investigated.. Gastric bypass appears to enhance glucagon-like peptide-1 production and suppress glucose-dependent insulinotropic polypeptide production. It appears that patients with type 2 diabetes and a greater BMI gain more benefit from the operation.. Bariatric surgery, particularly gastric bypass, has powerful and usually persistent effects on type 2 diabetes, dyslipidemia, and hypertension but randomized controlled trials with predefined metabolic entry criteria and planned comprehensive follow-up are required. Topics: Bariatric Surgery; Diabetes Mellitus, Type 2; Gastric Bypass; Glucagon-Like Peptide 1; Humans; Obesity; Randomized Controlled Trials as Topic | 2011 |
Add-on therapies to metformin for type 2 diabetes.
As of 2010, approximately 285 million people worldwide have diabetes; that number is estimated to increase to 439 million by 2030. The majority of these individuals (> 90%) have type 2 diabetes, a chronic and progressive disease.. Metformin monotherapy is a safe and effective option. However, its effects on glycemia are typically of limited durability. Progressive loss of β-cell function and failure of metformin monotherapy to control glucose adequately prompt the addition of other oral antidiabetic drugs, such as sulfonylureas and thiazolidinediones, which have their own limitations. Evidence suggests that incretin-based agents can successfully achieve glycemic control while potentially providing cardiovascular and β-cell-function benefits.. Knowledge of the available clinical evidence on the incretin-based therapies and other pharmacotherapeutic options for patients with type 2 diabetes who fail first-line therapy with metformin, through an analysis of improved glycemic parameters and overall risk:benefit profiles.. Traditional oral antidiabetic agents, recommended as first- and second-line therapies in patients with type 2 diabetes inadequately controlled with diet/exercise or monotherapy, have limited durability of effect and are associated with an increased risk of adverse events. Glucagon-like peptide-1 receptor agonists and dipeptidyl peptidase-4 inhibitors provide glycemic control and are promising additions to the pharmacotherapeutic armamentarium. Topics: Diabetes Mellitus, Type 2; Dipeptidyl-Peptidase IV Inhibitors; Disease Progression; Drug Therapy, Combination; Glucagon-Like Peptide 1; Humans; Hypoglycemic Agents; Incretins; Insulin; Life Style; Metformin; Treatment Failure | 2011 |
What to add in with metformin in type 2 diabetes?
This review considers the therapeutic choices currently faced by people with type 2 diabetes and those caring for them when glucose levels initially controlled with lifestyle management and metformin start to rise. While sulphonylureas are familiar agents and cheaper than other alternatives, they cause hypoglycaemia and modest weight gain, and robust outcome data are still lacking. Dipeptidyl peptidase 4 inhibitors ('gliptins') have an attractive pharmacological and adverse effect profile, but their effects on the cardiovascular system are also uncertain. Thiazolidinediones ('glitazones') are effective glucose-lowering agents, but cause weight gain and increase the risk of fracture, while the cardiovascular benefits hoped for in association with 'insulin-sensitization' have not been as expected. Glucagon-like peptide-1 agonists will not be acceptable as initial second-line agents for many people as they are injectable rather than oral. Well-powered 'head-to-head' clinical trials of adequate duration are therefore required to allow evidence-based decisions on second-line therapy. Topics: Diabetes Mellitus, Type 2; Dipeptidyl-Peptidase IV Inhibitors; Drug Synergism; Fractures, Bone; Glucagon-Like Peptide 1; Humans; Hypoglycemic Agents; Metformin; Risk Factors; Sulfonylurea Compounds; Thiazolidinediones; Weight Gain | 2011 |
Cardiovascular comorbidities of type 2 diabetes mellitus: defining the potential of glucagonlike peptide-1-based therapies.
The global epidemic of diabetes mellitus (~95% type 2 diabetes) has been fueled by a parallel increase in obesity and overweight. Together, these metabolic disease epidemics have contributed to the increasing incidence and prevalence of cardiovascular disease. The accumulation of metabolic and cardiovascular risk factors in patients with type 2 diabetes--risk factors that may exacerbate one another--complicates treatment. Inadequate treatment, treatment that fails to achieve goals, increases the risk for cardiovascular morbidity and mortality. From a clinical perspective, type 2 diabetes is a cardiovascular disease, an observation that is supported by a range of epidemiologic, postmortem, and cardiovascular imaging studies. Vascular wall dysfunction, and particularly endothelial dysfunction, has been posited as a "common soil" linking dysglycemic and cardiovascular diseases. Vascular wall dysfunction promoted by environmental triggers (e.g., sedentary lifestyle) and metabolic triggers (chronic hyperglycemia, obesity) has been associated with the upregulation of reactive oxygen species and chronic inflammatory and hypercoagulable states, and as such with the pathogenesis of type 2 diabetes, atherosclerosis, and cardiovascular disease. Glucagon-like peptide-1 (GLP)-1, an incretin hormone, and synthetic GLP-1 receptor agonists represent promising new areas of research and therapeutics in the struggle not only against type 2 diabetes but also against the cardiovascular morbidity and mortality associated with type 2 diabetes. In a number of small trials in humans, as well as in preclinical and in vitro studies, both native GLP-1 and GLP-1 receptor agonists have demonstrated positive effects on a range of cardiovascular disease pathologies and clinical targets, including such markers of vascular inflammation as high-sensitivity C-reactive protein, plasminogen activator inhibitor-1, and brain natriuretic peptide. Reductions in markers of dyslipidemia such as elevated levels of triglycerides and free fatty acids have also been observed, as have cardioprotective functions. Larger trials of longer duration will be required to confirm preliminary findings. In large human trials, GLP-1 receptor agonists have been associated with significant reductions in both blood pressure and weight. Topics: Biomarkers; Cardiovascular Diseases; Diabetes Mellitus, Type 2; Glucagon-Like Peptide 1; Humans; Incretins; Treatment Outcome | 2011 |
Pharmacological management of type 2 diabetes: the potential of incretin-based therapies.
Management guidelines recommend metformin as the first-line therapy for most patients with type 2 diabetes uncontrolled by diet and exercise. Efficacy with metformin therapy is usually of limited duration, which necessitates the early introduction of one or two additional oral agents or the initiation of injections, glucagon-like peptide-1 (GLP-1) agonists or insulin. Although safe and effective, metformin monotherapy has been associated with gastrointestinal side effects (≈20% of treated patients in randomized studies) and is contraindicated in patients with renal insufficiency or severe liver disease. Patients treated with a sulphonylurea are at increased risk for hypoglycaemia and moderate weight gain, whereas those receiving a thiazolidinedione are subject to an increased risk of weight gain, oedema, heart failure or fracture. Weight gain and hypoglycaemia are associated with insulin use. Thus, there is an unmet need for a safe and efficacious add-on agent after initial-therapy failure. Evidence suggests that incretin-based agents, such as GLP-1 receptor agonists and dipeptidyl peptidase-4 inhibitors, can successfully achieve glycaemic targets and potentially provide cardiovascular and β-cell-function benefits. This review will examine current approaches for treating type 2 diabetes and discuss the place of incretin therapies, mainly GLP-1 agonists, in the type 2 diabetes treatment spectrum. Topics: Diabetes Mellitus, Type 2; Dipeptidyl-Peptidase IV Inhibitors; Glucagon-Like Peptide 1; Glycated Hemoglobin; Humans; Hypoglycemic Agents; Incretins; Metformin | 2011 |
Liraglutide - overview of the preclinical and clinical data and its role in the treatment of type 2 diabetes.
Type 2 diabetes is characterized by a progressive decline in glycaemic control. Many standard diabetes treatments, however, fail to achieve or maintain glycaemic control, and are often associated with an increased risk of hypoglycaemia and weight gain. Recently developed incretin-based therapies are a promising addition to the current armamentarium of diabetes treatments. Two types of incretin-based therapies are currently available: glucagon-like peptide (GLP)-1 receptor agonists (liraglutide and exenatide) and dipeptidyl peptidase-4 inhibitors (sitaglipin, vildagliptin and saxagliptin). This review aims to summarize the key efficacy and safety data of liraglutide, a once-daily human GLP-1 analogue. Extensive phase III clinical trials have shown liraglutide to improve glycaemic control with additional benefits on body weight, blood pressure and β-cell function. Liraglutide is also generally well tolerated with a low risk of hypoglycaemia. Liraglutide has recently been approved for marketing in Europe, Japan and the USA. Topics: Body Weight; Clinical Trials, Phase II as Topic; Diabetes Mellitus, Type 2; Female; Glucagon-Like Peptide 1; Humans; Hypoglycemic Agents; Liraglutide; Male | 2011 |
Glucagon-like peptide-1-based therapies and cardiovascular disease: looking beyond glycaemic control.
Type 2 diabetes mellitus is a well-established risk factor for cardiovascular disease (CVD). New therapeutic approaches have been developed recently based on the incretin phenomenon, such as the degradation-resistant incretin mimetic exenatide and the glucagon-like peptide-1 (GLP-1) analogue liraglutide, as well as the dipeptidyl dipeptidase (DPP)-4 inhibitors, such as sitagliptin, vildagliptin, saxagliptin, which increase the circulating bioactive GLP-1. GLP-1 exerts its glucose-regulatory action via stimulation of insulin secretion and glucagon suppression by a glucose-dependent way, as well as by weight loss via inhibition of gastric emptying and reduction of appetite and food intake. These actions are mediated through GLP-1 receptors (GLP-1Rs), although GLP-1R-independent pathways have been reported. Except for the pancreatic islets, GLP-1Rs are also present in several other tissues including central and peripheral nervous systems, gastrointestinal tract, heart and vasculature, suggesting a pleiotropic activity of GLP-1. Indeed, accumulating data from both animal and human studies suggest a beneficial effect of GLP-1 and its metabolites on myocardium, endothelium and vasculature, as well as potential anti-inflammatory and antiatherogenic actions. Growing lines of evidence have also confirmed these actions for exenatide and to a lesser extent for liraglutide and DPP-4 inhibitors compared with placebo or standard diabetes therapies. This suggests a potential cardioprotective effect beyond glucose control and weight loss. Whether these agents actually decrease CVD outcomes remains to be confirmed by large randomized placebo-controlled trials. This review discusses the role of GLP-1 on the cardiovascular system and addresses the impact of GLP-1-based therapies on CVD outcomes. Topics: Cardiovascular Diseases; Cardiovascular System; Diabetes Mellitus, Type 2; Diabetic Angiopathies; Female; Glucagon-Like Peptide 1; Glucagon-Like Peptide-1 Receptor; Humans; Hypoglycemic Agents; Male; Receptors, Glucagon | 2011 |
[Role of the brain in the regulation of metabolism and energy expenditure: the central role of insulin, and insulin resistance of the brain].
Regulatory role of the brain in energy expenditure, appetite, glucose metabolism, and central effects of insulin has been prominently studied. Certain neurons in the hypothalamus increase or decrease appetite via orexigenes and anorexigenes, regulating energy balance and food intake. Hypothalamus is the site of afferent and efferent stimuli between special nuclei and beta- and alpha cells, and it regulates induction/inhibition of glucose output from the liver. Incretines, produced in intestine and in certain brain cells (brain-gut hormones), link to special receptors in the hypothalamus. Central role of insulin has been proved both in animals and in humans. Insulin gets across the blood-brain barrier, links to special hypothalamic receptors, regulating peripheral glucose metabolism. Central glucose sensing, via "glucose-excited" and "glucose-inhibited" cells have outstanding role. Former are active in hyperglycaemia, latter in hypoglycaemia, via influencing beta- and alpha cells, independently of traditional metabolic pathways. Evidence of brain insulin resistance needs centrally acting drugs, paradigm changes in therapy and prevention of metabolic syndrome, diabetes, cardiovascular and oncological diseases. Topics: Animals; Appetite Depressants; Appetite Regulation; Blood Glucose; Brain; Ceramides; Cognition; Diabetes Mellitus, Type 2; Energy Metabolism; Fatty Liver; Glucagon-Like Peptide 1; Humans; Hypothalamus; Incretins; Insulin; Insulin Resistance; Intracellular Signaling Peptides and Proteins; Metabolic Syndrome; Neuropeptides; Non-alcoholic Fatty Liver Disease; Oligopeptides; Orexins; Pyrrolidonecarboxylic Acid | 2011 |
An overview of once-weekly glucagon-like peptide-1 receptor agonists--available efficacy and safety data and perspectives for the future.
Incretin-based therapies, such as the injectable glucagon-like peptide-1 (GLP-1) receptor agonists and orally administered dipeptidyl peptidase-4 (DPP-4) inhibitors, have recently been introduced into clinical practice. At present, the GLP-1 receptor agonists need to be administered once or twice daily. Several once-weekly GLP-1 receptor agonists are in phase 3 development. This review examines the efficacy, safety and perspective for the future of the once-weekly GLP-1 receptor agonists: exenatide once weekly, taspoglutide, albiglutide, LY2189265 and CJC-1134-PC, and compared them to the currently available agonists, exenatide BID and liraglutide QD. A greater reduction in haemoglobin A1c (HbA1c) and fasting plasma glucose was found with the once-weekly GLP-1 receptor agonists compared with exenatide BID, while the effect on postprandial hyperglycaemia was modest with the once-weekly GLP-1 receptor agonist. The reduction in HbA1c was in most studies greater compared to oral antidiabetic drugs and insulin glargine. The reduction in weight did not differ between the short- and long-acting agonists. The gastrointestinal side effects were less with the once-weekly agonists compared with exenatide BID, except for taspoglutide. Antibodies seem to be most frequent with exenatide once weekly, while hypersensitivity has been described in few patients treated with taspoglutide. Injection site reactions differ among the long-acting GLP-1 receptor agonists and are observed more frequently than with exenatide BID and liraglutide. In humans, no signal has been found indicating an association between the once-weekly agonists and C-cell cancer. The cardiovascular safety, durability of glucose control and effect on weight will emerge from several ongoing major long-term trials. The once-weekly GLP-1 receptor analogues are promising candidates for the treatment of type 2 diabetes, although their efficacy may not be superior to once-daily analogue liraglutide. Topics: Biomarkers; Diabetes Mellitus, Type 2; Dipeptidyl-Peptidase IV Inhibitors; Exenatide; Female; Glucagon-Like Peptide 1; Glucagon-Like Peptide-1 Receptor; Glucagon-Like Peptides; Glycated Hemoglobin; Humans; Hyperglycemia; Hypoglycemic Agents; Immunoglobulin Fc Fragments; Liraglutide; Male; Peptides; Receptors, Glucagon; Recombinant Fusion Proteins; Venoms | 2011 |
[Pharmacological and clinical profile of alogliptin benzoate (NESINA®)].
Topics: Adult; Animals; Clinical Trials, Phase II as Topic; Diabetes Mellitus, Type 2; Disease Models, Animal; Drug Design; Glucagon-Like Peptide 1; Humans; Hypoglycemic Agents; Insulin; Insulin Secretion; Male; Piperidines; Rats; Uracil | 2011 |
Multifactorial intervention in Type 2 diabetes: the promise of incretin-based therapies.
Type 2 diabetes mellitus is increasing in prevalence at alarming rates. Concurrent with its expanding prevalence is the increase in the related risk of morbidity and mortality. Because diabetic patients are prone to cardiovascular disease, treatment strategies should address the cardiovascular risk factors, including blood pressure, lipids, and body weight, in addition to the glycemic aspects of the disease. Newer agents, such as glucagon-like peptide-1 (GLP-1) analogs and dipeptidyl peptidase-4 (DPP-4) inhibitors, have varying degrees of evidence to support their effects on body weight, blood pressure, and lipid levels, beyond glycated hemoglobin reduction. While GLP-1 agonists produce a weight loss, the DPP-4 inhibitors, conversely, appear to have a weight-neutral effect. Substantial evidence demonstrates that both medications produce modest reductions in systolic blood pressure and, in some cases, diastolic blood pressure, and reduce several markers of cardiovascular risk, including C-reactive protein. Moreover, GLP-1 influences endothelial function. The effect of the incretin hormones on serum lipids are either neutral or beneficial, with small, non-significant decreases in LDL cholesterol, increases in HDL cholesterol, and occasionally significant decreases in fasting triglyceride levels. Also, they have positive effects on hepatic steatosis. Although GLP-1 agonists and DPP-4 inhibitors are at present not appropriate for primary treatment of cardiovascular risks factors, the reduction of these parameters is evidently beneficial. Topics: Animals; Combined Modality Therapy; Diabetes Mellitus, Type 2; Glucagon-Like Peptide 1; Health Services Needs and Demand; Humans; Incretins; Models, Biological; Patient Care Planning | 2011 |
GLP-1 for type 2 diabetes.
Glucagon-like peptide-1 (GLP-1)-based therapy of type 2 diabetes is executed either by GLP-1 receptor agonists, which stimulate the GLP-1 receptors, or by dipeptidyl peptidase-4 (DPP-4) inhibitors, which prevent the inactivation of endogenous GLP-1 thereby increasing the concentration of endogenous active GLP-1. GLP-1 activates pancreatic receptors resulting in improved glycemia through glucose-dependent stimulation of insulin secretion and inhibition of glucagon secretion. There is also a potential beta cell preservation effect, as judged from rodent studies. GLP-1 receptors are additionally expressed in extrapancreatic tissue, having potential for the treatment to reduce body weight and to potentially have beneficial cardio- and endothelioprotective effects. Clinical trials in subjects with type 2 diabetes have shown that in periods of 12 weeks or more, these treatments reduce HbA(1c) by ≈ 0.8-1.1% from baseline levels of 7.7-8.5%, and they are efficient both as monotherapy and in combination therapy with metformin, sulfonylureas, thiazolidinediones or insulin. Furthermore, GLP-1 receptor agonists reduce body weight, whereas DPP-4 inhibitors are body weight neutral. The treatment is safe with very low risk for adverse events, including hypoglycaemia. GLP-1 based therapy is thus a novel and now well established therapy of type 2 diabetes, with a particular value in combination with metformin in patients who are inadequately controlled by metformin alone. Topics: Animals; Clinical Trials as Topic; Diabetes Mellitus, Type 2; Dipeptidyl Peptidase 4; Glucagon-Like Peptide 1; Glucagon-Like Peptide-1 Receptor; Humans; Protease Inhibitors; Receptors, Glucagon | 2011 |
What's new in diabetes: incretins and C-peptide.
Topics: C-Peptide; Diabetes Mellitus, Type 2; Glucagon-Like Peptide 1; Humans; Incretins | 2011 |
Focus on incretin-based therapies: targeting the core defects of type 2 diabetes.
Glucose homeostasis is regulated by a complex interaction of hormones, principally including insulin, glucagon, amylin, and the incretins. Glucagon, cortisol, catecholamines, and growth hormone serve as the classic glucose counterregulatory hormones. The incretins are hormones released by enteroendocrine cells in the intestine in response to a meal. Classically, type 2 diabetes mellitus (T2DM) has been considered to be a triad of insulin resistance, increased hepatic gluconeogenesis, and progressive β-cell exhaustion/failure. However, disordered enteroendocrine physiology, specifically the reduced activity of glucagon-like peptide-1 (GLP-1), is also a principal pathophysiologic abnormality of the disease. Glucagon-like peptide-1 receptor agonists that have been studied include exenatide and liraglutide, which have been approved by the US Food and Drug Administration for use in patients with T2DM. Sitagliptin and saxagliptin, both approved for use in the United States, modulate incretin physiology by inhibiting degradation of GLP-1 by the enzyme dipeptidyl peptidase-4 (DPP-4). Modulators of incretin physiology have been shown to improve glycemic control with a low risk for hypoglycemia and beneficially affect β-cell function. Unlike the DPP-4 inhibitors, GLP-1 receptor agonist therapy also produces weight loss, an important consideration given the close association among T2DM, overweight/obesity, and cardiovascular disease. The GLP-1 receptor agonists have also demonstrated beneficial effects on cardiovascular risk factors other than hyperglycemia and excess body weight, such as lipid concentrations and blood pressure. This article describes incretin physiology and studies of pharmacologic therapy designed to address the blunted incretin response in patients with T2DM. Information was obtained by a search of the PubMed and MEDLINE databases for articles published from January 1, 1995 to June 1, 2009. Topics: Adamantane; Cardiovascular Diseases; Clinical Trials as Topic; Diabetes Mellitus, Type 2; Dipeptides; Dipeptidyl-Peptidase IV Inhibitors; Exenatide; Glucagon-Like Peptide 1; Glucagon-Like Peptide-1 Receptor; Humans; Hypoglycemic Agents; Incretins; Liraglutide; Peptides; Pyrazines; Receptors, Glucagon; Sitagliptin Phosphate; Triazoles; Venoms | 2011 |
Pharmacology of GLP-1 agonists: describing the therapeutic potential to patients.
The pathophysiology of type 2 diabetes mellitus is complex, consisting of far more physiologic defects than simple insulin resistance and β-cell dysfunction. Our understanding of this progressive disease has moved from a "dual defect" to an "ominous octet" description. This multifactoral concept may explain the difficulty in achieving and maintaining glycemic goals with traditional therapies. Glucagon-like peptide-1 (GLP-1) agonists, which improve insulin secretion, decrease glucagon secretion, increase satiety (and therefore decrease food intake), and may have beneficial effects on β-cell function, represent an important addition to treatment options. Their glucose-dependent mechanism limits the risk for hypoglycemia, and they are associated with weight loss. Glucagon-like peptide-1 agonists may be used alone in patients intolerant of metformin or in combination with metformin, thiazolidinediones, and sulfonylureas (or in any combination therereof). Concomitant use of dipeptidyl-peptidase-4 inhibitors is not recommended because they have a similar basis of action. Current US Food and Drug Administration indications do not include the concomitant use of GLP-1 agonists with insulin. Topics: Algorithms; Chronic Disease; Diabetes Mellitus, Type 2; Exenatide; Glucagon-Like Peptide 1; Glycated Hemoglobin; Humans; Hypoglycemic Agents; Incretins; Male; Middle Aged; Peptides; Pyrazines; Sitagliptin Phosphate; Triazoles; Venoms | 2011 |
Optimizing outcomes for GLP-1 agonists.
The management of type 2 diabetes mellitus and, in particular, blood glucose levels can be complex and challenging for physicians and patients. Many patients are frustrated with the agents currently available because they have associated limitations of weight gain, hypoglycemia, and tolerability issues. Advantages of glucagon-like peptide-1 (GLP-1) agonists include their efficacy in lowering blood glucose levels, their lack of association with weight gain, and their indirect association with weight loss. Patients likely to benefit from GLP-1 agonist therapy are those in the early stages of the disease and those in need of sufficient benefit from an agent with good efficacy. Setting appropriate expectations for patients is important, as well as explaining the significance of glucose control and reminding patients that this is the main goal of therapy. Patients (and physicians) who have concerns about hypoglycemia can be reassured that GLP-1 agonists work only in the presence of hyperglycemia. Longer-acting GLP-1 agonists are dosed less frequently, appear to be associated with less nausea, and may be associated with better rates of adherence than shorter-acting agents. When initiating therapy with GLP-1 agonists, doses should be gradually escalated to minimize gastrointestinal adverse effects. The dose of a sulfonylurea may need to be lowered if a GLP-1 agonist is added. A review of possible adverse effects, contraindications, dosing and administration techniques, and expected benefits of therapy is provided in the present article to optimize success rates with this new class of agents. Topics: Algorithms; Blood Glucose; Body Weight; Diabetes Mellitus, Type 2; Exenatide; Glucagon-Like Peptide 1; Glycated Hemoglobin; Humans; Hypoglycemic Agents; Incretins; Liraglutide; Male; Metformin; Middle Aged; Peptides; Sulfonylurea Compounds; Treatment Outcome; Venoms | 2011 |
Lixisenatide for type 2 diabetes mellitus.
Type 2 diabetes mellitus (T2DM) is an increasing health problem worldwide. Glucagon-like peptide-1 (GLP-1) receptor agonists are an expanding drug class that target several of the pathophysiological traits of T2DM. Lixisenatide is a GLP-1 receptor agonist in development for once-daily treatment of T2DM.. Pharmacological, preclinical and clinical evidence demonstrating the applicability of lixisenatide for the treatment of T2DM are reviewed. Available data and pending clinical development are summarized, critically appraised and compared to competitor drugs. The most relevant papers and meeting abstracts published up to November 2010 are used as sources for this review.. Efficacy and safety in T2DM are demonstrated with lixisenatide in monotherapy and in combination with metformin. However, limited data with the intended once-daily 20 μg subcutaneous dosing necessitate further evaluation of lixisenatide as add-on to various antidiabetic treatments. It remains to be established whether the slightly differing chemical properties compared to other GLP-1 receptor agonists including a rather short duration of action will be a disadvantage or maybe even an advantage, for example, when combined with long-acting insulin. Topics: Animals; Clinical Trials as Topic; Diabetes Mellitus, Type 2; Drug Evaluation, Preclinical; Drug Therapy, Combination; Glucagon-Like Peptide 1; Humans; Hypoglycemic Agents; Metformin; Peptides | 2011 |
Obesity - an indication for GLP-1 treatment? Obesity pathophysiology and GLP-1 treatment potential.
Obesity is common and associated with a high rate of morbidity and mortality; therefore, treatment is of great interest. At present, bariatric surgery is the only truly successful treatment of severe obesity. Mimicking one of the effects of bariatric surgery, namely the increased secretion of glucagon-like peptide (GLP)-1, by artificially increasing the levels of GLP-1 might prove successful as obesity treatment. Recent studies have shown that GLP-1 is a physiological regulator of appetite and food intake. The effect on food intake and satiety is preserved in obese subjects and GLP-1 may therefore have a therapeutic potential. The GLP-1 analogues result in a moderate average weight loss, which is clinically relevant in relation to reducing the risk of type 2 diabetes and cardiovascular disease. Inspired by the hormone profile after gastric bypass, a future strategy in obesity drug development could be to combine several hormones, and thereby produce a superior appetite suppressing hormone profile that may result in a weight loss exceeding that seen in single-agent trials. In conclusion, with the GLP-1 analogues combining a moderate weight loss with beneficial effects on metabolic and cardiovascular risk factors, it seems that we are on the right track for future treatment of obesity. Topics: Animals; Appetite; Bariatric Surgery; Cardiovascular Diseases; Diabetes Mellitus, Type 2; Eating; Glucagon-Like Peptide 1; Humans; Obesity; Risk Factors; Satiation; Weight Loss | 2011 |
Incretin therapies in the management of elderly patients with type 2 diabetes mellitus.
Aging is characterized by a progressive increase in the prevalence of type 2 diabetes mellitus (T2DM), which approaches 20% by age 70 years. Older patients with T2DM are a very heterogeneous group with multiple comorbidities, an increased risk of hypoglycemia, and a greater susceptibility to adverse effects of antihyperglycemic drugs, making treatment of T2DM in this population challenging. The risk of severe hypoglycemia likely represents the greatest barrier to T2DM care in the elderly. Although recent guidelines recommend more flexibility in treating this population with individualized targets, inadequate glycemic control is still closely linked to poor outcome in elderly patients. Incretins (glucose-dependent insulinotropic polypeptide [GIP] and glucagon-like peptide-1 [GLP-1]) are hormones released post-meal from intestinal endocrine cells that stimulate insulin secretion and suppress postprandial glucagon secretion in a glucose-dependent manner. "Incretin therapies," comprising the injectable GLP-1 analogs and oral dipeptidyl peptidase-4 (DPP-4) inhibitors, are promising new therapies for use in older patients because of their consistent efficacy and low risk of hypoglycemia. However, data with these new agents are still scarce in this population, which has not been particularly well represented in clinical trials, highlighting the need for additional specific studies. The objective of this article is to provide an overview of the available data and potential role of these novel incretin therapies in managing T2DM in the elderly. With the exception of the DPP-4 inhibitor vildagliptin, there is no published trial to date dedicated to this population, although a few studies are currently ongoing. Therefore, available data from elderly subgroups of individual studies were also reviewed when available, as well as pooled analyses by age subgroups across clinical programs conducted with incretin therapies. Topics: Adamantane; Age Factors; Aged; Aging; Clinical Trials as Topic; Diabetes Mellitus, Type 2; Dipeptides; Dipeptidyl-Peptidase IV Inhibitors; Exenatide; Female; Glucagon-Like Peptide 1; Humans; Hypoglycemic Agents; Incretins; Linagliptin; Liraglutide; Male; Middle Aged; Nitriles; Peptides; Piperidines; Purines; Pyrazines; Pyrrolidines; Quinazolines; Sitagliptin Phosphate; Treatment Outcome; Triazoles; Uracil; Venoms; Vildagliptin | 2011 |
Targeting type 2 diabetes.
The evolving concept of how nutrient excess and inflammation modulate metabolism provides new opportunities for strategies to correct the detrimental health consequences of obesity. In this review, we focus on the complex interplay among lipid overload, immune response, proinflammatory pathways and organelle dysfunction through which excess adiposity might lead to type 2 diabetes. We then consider evidence linking dysregulated CNS circuits to insulin resistance and results on nutrient-sensing pathways emerging from studies with calorie restriction. Subsequently, recent recommendations for the management of type 2 diabetes are discussed with emphasis on prevailing current therapeutic classes of biguanides, thiazolidinediones and incretin-based approaches. Topics: Adipose Tissue; Caloric Restriction; Diabetes Mellitus, Type 2; Dipeptidyl-Peptidase IV Inhibitors; Glucagon-Like Peptide 1; Glucose; Homeostasis; Humans; Hypoglycemic Agents; Inflammation; Insulin Resistance; Insulin-Secreting Cells; Metformin; Signal Transduction; Thiazolidines | 2011 |
GLP-1 agonists and dipeptidyl-peptidase IV inhibitors.
Novel therapeutic options for type 2 diabetes based on the action of the incretin hormone glucagon-like peptide-1 (GLP-1) were introduced in 2005. Incretin-based therapies consist of two classes: (1) the injectable GLP-1 receptor agonists solely acting on the GLP-1 receptor and (2) dipeptidyl-peptidase inhibitors (DPP-4 inhibitors) as oral medications raising endogenous GLP-1 and other hormone levels by inhibiting the degrading enzyme DPP-4. In type 2 diabetes therapy, incretin-based therapies are attractive and more commonly used due to their action and safety profile. Stimulation of insulin secretion and inhibition of glucagon secretion by the above-mentioned agents occur in a glucose-dependent manner. Therefore, incretin-based therapies have no intrinsic risk for hypoglycemias. GLP-1 receptor agonists allow weight loss; DPP-4 inhibitors are weight neutral. This review gives an overview on the mechanism of action and the substances and clinical data available. Topics: Diabetes Mellitus, Type 1; Diabetes Mellitus, Type 2; Dipeptidyl Peptidase 4; Dipeptidyl-Peptidase IV Inhibitors; Glucagon-Like Peptide 1; Guidelines as Topic; Humans; Hypoglycemic Agents; Incretins | 2011 |
The safety and tolerability of GLP-1 receptor agonists in the treatment of type 2 diabetes: a review.
Although several classes of pharmacotherapy are available for type 2 diabetes, glycaemic control is often hampered by medication-related adverse effects and contraindications such as renal impairment. Glucagon-like peptide-1 (GLP-1) receptor agonists provide a new pharmacotherapeutic option based on the multiple glucose-lowering effects of the human hormone GLP-1. This mechanism of action not only provides therapeutic efficacy but also suggests that GLP-1 receptor agonists have distinct safety and tolerability concerns compared with other diabetes therapies. Stimulation of pancreatic insulin secretion by GLP-1 receptor agonists is glucose dependent, conferring a lesser risk of hypoglycaemia than that seen with sulfonylureas. Individual GLP-1 receptor agonists differ in their metabolism and excretion profiles, affecting the choice of agent for patients with renal impairment. As with other protein-based therapies, GLP-1 receptor agonists may induce the formation of antibodies that may attenuate therapeutic efficacy and affect safety. Conclusions on cardiovascular safety must await outcomes studies, but at present no signal of harm has been reported, and preclinical data and effects on risk markers suggest a potential for benefit. Current data on thyroid medullary cancer in humans and pancreatic malignancy in rodents do not suggest that there is any reason to restrict the clinical use of GLP-1 analogues in most people with diabetes. It is currently difficult to ascertain the possible contributory role of GLP-1 receptor agonists in increasing the risk of pancreatitis, and vigilance for signs and symptoms is prudent. Primary tolerability issues include transient gastrointestinal symptoms, common with GLP-1 receptor agonists, which can be reduced through dose titration. Topics: Diabetes Mellitus, Type 2; Dipeptidyl Peptidase 4; Dipeptidyl-Peptidase IV Inhibitors; Drug-Related Side Effects and Adverse Reactions; Exenatide; Glucagon-Like Peptide 1; Glucagon-Like Peptide-1 Receptor; Humans; Hypoglycemia; Incretins; Liraglutide; Nausea; Pancreatitis; Peptides; Randomized Controlled Trials as Topic; Receptors, Glucagon; Thyroid Gland; Venoms; Vomiting | 2011 |
Mechanisms of action of the dipeptidyl peptidase-4 inhibitor vildagliptin in humans.
Inhibition of dipeptidyl peptidase-4 (DPP-4) by vildagliptin prevents degradation of glucagon-like peptide-1 (GLP-1) and reduces glycaemia in patients with type 2 diabetes mellitus, with low risk for hypoglycaemia and no weight gain. Vildagliptin binds covalently to the catalytic site of DPP-4, eliciting prolonged enzyme inhibition. This raises intact GLP-1 levels, both after meal ingestion and in the fasting state. Vildagliptin has been shown to stimulate insulin secretion and inhibit glucagon secretion in a glucose-dependent manner. At hypoglycaemic levels, the counterregulatory glucagon response is enhanced relative to baseline by vildagliptin. Vildagliptin also inhibits hepatic glucose production, mainly through changes in islet hormone secretion, and improves insulin sensitivity, as determined with a variety of methods. These effects underlie the improved glycaemia with low risk for hypoglycaemia. Vildagliptin also suppresses postprandial triglyceride (TG)-rich lipoprotein levels after ingestion of a fat-rich meal and reduces fasting lipolysis, suggesting inhibition of fat absorption and reduced TG stores in non-fat tissues. The large body of knowledge on vildagliptin regarding enzyme binding, incretin and islet hormone secretion and glucose and lipid metabolism is summarized, with discussion of the integrated mechanisms and comparison with other DPP-4 inhibitors and GLP-1 receptor activators, where appropriate. Topics: Adamantane; Diabetes Mellitus, Type 2; Dipeptidyl Peptidase 4; Dipeptidyl-Peptidase IV Inhibitors; Glucagon-Like Peptide 1; Humans; Nitriles; Pyrrolidines; Vildagliptin | 2011 |
Liraglutide: a review of the first once-daily GLP-1 receptor agonist.
Liraglutide is an analog with 97% homology to human glucagon-like peptide (GLP-1) and acts as a GLP-1 receptor agonist. Several large, randomized, multicenter phase 3 trials evaluated the efficacy and safety of liraglutide by comparing monotherapy and combination therapy with other antidiabetic medications in adult patients with type 2 diabetes. The Liraglutide Effect and Action in Diabetes (LEAD) program demonstrated that liraglutide, when used alone or in combination with other antidiabetic medications, effectively controls hyperglycemia (glycosylated hemoglobin [A1C] reductions up to 1.6%) and assists patients in meeting established glycemic targets. Compared with certain other classes of antidiabetic agents, liraglutide is associated with a lower risk of hypoglycemia. Liraglutide has also been associated with weight loss (1.8 to 3.4 kg) and improved patient satisfaction and health-related quality of life. Several studies have demonstrated that GLP-1 receptor agonists may improve pancreatic beta cell function, which may delay disease progression if maintained over the long term. As with any drug, liraglutide is not without risk, and a patient's complete clinical status and benefit-to-risk profile should be considered before prescribing treatment. For patients with type 2 diabetes who have failed to achieve glycemic control through diet and exercise, liraglutide may be an important treatment option. The current consensus statement of the American Association of Clinical Endocrinologists (AACE) and the American College of Endocrinology (ACE) cites efficacy and low risk of hypoglycemia in preferring GLP-1 agonists and dipeptidyl peptidase-4 (DPP-4) inhibitors over sulfonylureas and glinides, after initial treatment with metformin. The guidelines prefer GLP-1 agonists over DPP-4 inhibitors because of their actions that promote weight loss and their somewhat greater effectiveness in reducing postprandial glucose excursions. Topics: Diabetes Mellitus, Type 2; Glucagon-Like Peptide 1; Glucagon-Like Peptide-1 Receptor; Humans; Liraglutide; Receptors, Glucagon | 2011 |
Long-acting glucagon-like peptide 1 receptor agonists: a review of their efficacy and tolerability.
Topics: Diabetes Mellitus, Type 2; Exenatide; Glucagon-Like Peptide 1; Humans; Hypoglycemic Agents; Liraglutide; Peptides; Venoms | 2011 |
Insulin treatment for type 2 diabetes: when to start, which to use.
In type 2 diabetes mellitus, oral hypoglycemic agents and analogues of glucagon-like peptide-1 provide adequate glycemic control early in the disease. Insulin therapy becomes necessary for those with advanced disease. Further, some experts recommend electively starting insulin therapy in early diabetes. This review addresses practical approaches to insulin therapy, particularly when it is indicated and which regimen to use. Topics: Diabetes Mellitus, Type 2; Drug Therapy, Combination; Glucagon-Like Peptide 1; Humans; Hyperglycemia; Hypoglycemic Agents; Incretins; Insulin; Metformin; Risk Factors | 2011 |
Liraglutide: once-daily GLP-1 agonist for the treatment of type 2 diabetes.
The prevalence of diabetes is increasing worldwide. Over the recent years, new discoveries have led to the development of new pharmacological agents targeting the incretin hormones gastric inhibitory peptide (GIP) and glucagon-like peptide-1 (GLP-1). These agents, called incretin-mimetics, are the newest agents added to the diabetes treatment options. The purpose of this article is to review the relevant literature on the chemistry, pharmacology, pharmacokinetics, metabolism, clinical trials, safety, drug interactions and place in therapy of liraglutide in the treatment of type 2 diabetes.. An extensive search of the literature was performed with liraglutide and NN2211 as key terms. This article presents a review of the literature related to the chemistry, pharmacology, pharmacokinetics, drug interactions and safety and efficacy of liraglutide.. Liraglutide, a subcutaneously administered GLP-1 agonist, displays phamacodynamic and pharmacokinetic properties that allow for once-daily administration. The agent has been shown to be efficacious as monotherapy, as well as in combination with glimperide, metformin and/or rosiglitazone, reducing glycoslyated haemoglobin (A1C) between 0·84% and 1·5%. The primary adverse event reported with liraglutide is transient nausea.. Liraglutide has been well studied in dual and triple combination therapies with sulfonylureas, metformin and rosiglitazone and appears safe and effective. For patients who cannot tolerate first-line agents, metformin, insulin and sulfonylureas, liraglutide is a reasonable treatment option. Topics: Animals; Diabetes Mellitus, Type 2; Glucagon-Like Peptide 1; Humans; Hypoglycemic Agents; Incretins; Liraglutide; Nausea | 2011 |
Liraglutide for type 2 diabetes mellitus.
Prevalence of type 2 diabetes mellitus (T2DM) is increasing. Management of this condition and minimizing the cardiovascular risks associated with it poses a significant burden on healthcare resources across the world. Currently available therapeutic agents are effective in glycemic management; however, the majority of these are associated with undesirable effects such as hypoglycemia and weight gain. Incretin-based therapies have been introduced over the last few years and are associated with less risk of hypoglycemia and weight gain.. This review includes current challenges in the management of T2DM, and an overview of glucagon-like peptide-1 (GLP-1)-based therapies, in particular the results of Phase III clinical studies of recently approved liraglutide. Apart from glycemic control, multifactorial interventions are needed to minimize the cardiovascular risks associated with T2DM. Liraglutide is effective in improving glycemic control measured by HbA1c and it is also shown to improve weight. Recently, the National Institute of Health and Clinical Excellence in the UK has approved liraglutide 1.2 mg dose in dual and triple therapy for T2DM.. Liraglutide, a once-daily GLP-1 analog, has a definite role in selected patients with T2DM and the long-term cardiovascular safety is currently being ascertained in ongoing trials. Topics: Biomarkers; Blood Glucose; Diabetes Mellitus, Type 2; Drug Administration Schedule; Evidence-Based Medicine; Glucagon-Like Peptide 1; Glycated Hemoglobin; Humans; Hypoglycemic Agents; Liraglutide; Treatment Outcome | 2011 |
Effects of insulin and other antihyperglycaemic agents on lipid profiles of patients with diabetes.
Increased morbidity and mortality risk due to diabetes-associated cardiovascular diseases is partly associated with hyperglycaemia as well as dyslipidaemia. Pharmacological treatment of diabetic hyperglycaemia involves the use of the older oral antidiabetic drugs [OADs: biguanides, sulphonylureas (SUs), α-glucosidase inhibitors and thiazolidinediones], insulin (human and analogues) and/or incretin-based therapies (glucagon-like peptide-1 analogues and dipeptidyl peptidase 4 inhibitors). Many of these agents have also been suggested to improve lipid profiles in patients with diabetes. These effects may have benefits on cardiovascular risk beyond glucose-lowering actions. This review discusses the effects of OADs, insulins and incretin-based therapies on lipid variables along with the possible mechanisms and clinical implications of these findings. The effects of intensive versus conventional antihyperglycaemic therapy on cardiovascular outcomes and lipid profiles are also discussed. A major conclusion of this review is that agents within the same class of OADs can have different effects on lipid variables and that contrary to the findings in experimental models, insulin has been shown to have beneficial effects on lipid variables in clinical trials. Further studies are needed to understand the precise effect and the mechanisms of these effects of insulin on lipids. Topics: Biguanides; Cardiovascular Diseases; Diabetes Mellitus, Type 2; Diabetic Angiopathies; Dipeptidyl-Peptidase IV Inhibitors; Glucagon-Like Peptide 1; Glycoside Hydrolase Inhibitors; Humans; Hyperglycemia; Hypoglycemic Agents; Incretins; Insulin; Randomized Controlled Trials as Topic; Sulfonylurea Compounds; Thiazolidinediones | 2011 |
Glucagon-like peptide-1 receptor agonists and cardiovascular events: a meta-analysis of randomized clinical trials.
Data from randomized clinical trials with metabolic outcomes can be used to address concerns about potential issues of cardiovascular safety for newer drugs for type 2 diabetes. This meta-analysis was designed to assess cardiovascular safety of GLP-1 receptor agonists.. MEDLINE, Embase, and Cochrane databases were searched for randomized trials of GLP-1 receptor agonists (versus placebo or other comparators) with a duration ≥12 weeks, performed in type 2 diabetic patients. Mantel-Haenszel odds ratio with 95% confidence interval (MH-OR) was calculated for major cardiovascular events (MACE), on an intention-to-treat basis, excluding trials with zero events.. Out of 36 trials, 20 reported at least one MACE. The MH-OR for all GLP-1 receptor agonists was 0.74 (0.50-1.08), P = .12 (0.85 (0.50-1.45), P = .55, and 0.69 (0.40-1.22), P = .20, for exenatide and liraglutide, resp.). Corresponding figures for placebo-controlled and active comparator studies were 0.46 (0.25-0.83), P = .009, and 1.05 (0.63-1.76), P = .84, respectively.. To date, results of randomized trials do not suggest any detrimental effect of GLP-1 receptor agonists on cardiovascular events. Specifically designed longer-term trials are needed to verify the possibility of a beneficial effect. Topics: Algorithms; Cardiovascular Diseases; Diabetes Mellitus, Type 2; Exenatide; Glucagon-Like Peptide 1; Glucagon-Like Peptide-1 Receptor; Humans; Hypoglycemic Agents; Liraglutide; Peptides; Randomized Controlled Trials as Topic; Receptors, Glucagon; Venoms | 2011 |
[Liraglutide].
Liraglutide is the first once-daily human GLP-1 analogue developed for the treatment of type 2 diabetes mellitus(T2DM). The half-life of liraglutide is 13 h following subcutaneous injection, making it suitable for once-daily dosing. Clinical data indicates improved beta cell function with liraglutide treatment in patients with T2DM. Liraglutide increases insulin secretion in a glucose-dependent manner, and improves first- and second-phase insulin responses. Liraglutide delays the rate of gastric emptying, reduces energy intake and exerts a moderate suppression on hunger as indicates by diverse appetite rating endpoints. Liraglutide dose not impair the counter-regulatory glucagons response to hypoglycaemia in patients with T2DM, which is consistent with the glucose-dependent action of liraglutide. Liraglutide was associated with no major or minor hypoglycaemia and was generally well tolerated, with the most common side-effect reported as mild, transient nausea. Liraglutide allows significantly more patients to achieve HbAlc targets compared with current treatment. Liraglutide significantly reduces weight in patients. Topics: Diabetes Mellitus, Type 2; Glucagon-Like Peptide 1; Humans; Liraglutide | 2011 |
[Emerging GLP-1 analogues and dipeptidyl peptidase 4(DPP-4) inhibitors].
In recent years new antidiabetic medications utilizing incretin effects came to clinical practice, and enthusiasm surrounding this class of drugs has been mounting for their clinical efficacy as well as expected beneficial effects beyond lowering blood glucose levels. New DPP-4 inhibitors are expected to be available soon in addition to currently available DPP-4 inhibitors, sitagliptin, vildagliptin, and alogliptin. GLP-1 analogues, presently liraglutide and exenatide in clinical use, will also see newer alternatives in coming years. Long-acting GLP-1 analogues, which only require weekly or monthly injection, have also been developed, and their favorable clinical results have been reported. In this review, those newly developing DPP-4 inhibitors and GLP-1 analogues and their clinical efficacy are described. Topics: Diabetes Mellitus, Type 2; Dipeptidyl-Peptidase IV Inhibitors; Glucagon-Like Peptide 1; Humans | 2011 |
Liraglutide for the treatment of type 2 diabetes.
This paper presents a summary of the evidence review group (ERG) report into the clinical effectiveness and cost-effectiveness of liraglutide in the treatment of type 2 diabetes mellitus, based upon the manufacturer's submission to the National Institute for Health and Clinical Excellence (NICE) as part of the single technology appraisal process. The manufacturer proposed the use of liraglutide as a second or third drug in patients with type 2 diabetes whose glycaemic control was unsatisfactory with metformin, with or without a second oral glucose-lowering drug. The submission included six manufacturer-sponsored trials that compared the efficacy of liraglutide against other glucose-lowering agents. Not all of the trials were relevant to the decision problem. The most relevant were Liraglutide Effects and Actions in Diabetes 5 (LEAD-5) (liraglutide used as part of triple therapy and compared against insulin glargine) and LEAD-6 [liraglutide in triple therapy compared against another glucagon-like peptide-1 agonist, exenatide]. Five of the six trials were published in full and one was then unpublished. Two doses of liraglutide, 1.2 and 1.8 mg, were used in some trials, but in the two comparisons in triple therapy, against glargine and exenatide, only the 1.8-mg dose was used. Liraglutide in both doses was found to be clinically effective in lowering blood glucose concentration [glycated haemoglobin (HbA1c)], reducing weight (unlike other glucose-lowering agents, such as sulphonylureas, glitazones and insulins, which cause weight gain) and also reducing systolic blood pressure (SBP). Hypoglycaemia was uncommon. The ERG carried out meta-analyses comparing the 1.2- and 1.8-mg doses of liraglutide, which suggested that there was no difference in control of diabetes, and only a slight difference in weight loss, insufficient to justify the extra cost. The cost-effectiveness analysis was carried out using the Center for Outcomes Research model. The health benefit was reported as quality-adjusted life-years (QALYs). The manufacturer estimated the cost-effectiveness to be £ 15,130 per QALY for liraglutide 1.8 mg compared with glargine, £ 10,054 per QALY for liraglutide 1.8 mg compared with exenatide, £ 10,465 per QALY for liraglutide 1.8 mg compared with sitagliptin, and £ 9851 per QALY for liraglutide 1.2 mg compared with sitagliptin. The ERG conducted additional sensitivity analyses and concluded that the factors that carried most weight were: in the comparison wi Topics: Clinical Trials, Phase III as Topic; Cost-Benefit Analysis; Diabetes Mellitus, Type 2; Drug Therapy, Combination; Glucagon-Like Peptide 1; Glycated Hemoglobin; Humans; Hypoglycemic Agents; Liraglutide; Meta-Analysis as Topic; Metformin; Multicenter Studies as Topic; Quality-Adjusted Life Years; Randomized Controlled Trials as Topic; Weight Loss | 2011 |
Diabetes mellitus: new drugs for a new epidemic.
The prevalence of diabetes mellitus (DM) is increasing rapidly in the 21st century as a result of obesity, an ageing population, lack of exercise, and increased migration of susceptible patients. This costly and chronic disease has been likened recently to the 'Black Death' of the 14th century. Type 2 DM is the more common form and the primary aim of management is to delay the micro- and macrovascular complications by achieving good glycaemic control. This involves changes in lifestyle, such as weight loss and exercise, and drug therapy. Increased knowledge of the pathophysiology of diabetes has contributed to the development of novel treatments: glucagon-like peptide-1 (GLP-1) mimetics, dipeptidyl peptidase-4 (DPP-4) inhibitors, thiazolidinediones (TZDs), and insulin analogues. GLP-1 agonists mimic the effect of this incretin, whereas DPP-4 inhibitors prevent the inactivation of the endogenously released hormone. Both agents offer an effective alternative to the currently available hypoglycaemic drugs but further evaluation is needed to confirm their safety and clinical role. The past decade has seen the rise and fall in the use of the TZDs (glitazones), such that the only glitazone recommended is pioglitazone as a third-line treatment. The association between the use of rosiglitazone and adverse cardiac outcomes is still disputed by some authorities. The advent of new insulin analogues, fast-acting, and basal release formulations, has enabled the adoption of a basal-bolus regimen for the management of blood glucose. This regimen aims to provide a continuous, low basal insulin release between meals with bolus fast-acting insulin to limit hyperglycaemia after meals. Insulin therapy is increasingly used in type 2 DM to enhance glycaemic control. Recently, it has been suggested that the use of the basal-release insulins, particularly insulin glargine may be associated with an increased risk of cancer. Although attention is focused increasingly on newer agents in the treatment of diabetes, metformin and the sulphonylureas are still used in many patients. Metformin, in particular, remains of great value and may have novel anti-cancer properties. Topics: Diabetes Mellitus; Diabetes Mellitus, Type 2; Dipeptidyl Peptidase 4; Glucagon-Like Peptide 1; Humans; Hypoglycemic Agents; Insulin; Thiazolidinediones | 2011 |
[Treatment of type 2 diabetes mellitus with GLP-1 agonists].
Increased prevalence of type 2 diabetes mellitus and its close clustering with obesity, arterial hypertension, dyslipidemia and other pathologies commonly referred to as metabolic or insulin resistance syndrome, represents one of the major health problem worldwide. The side effects of most of oral antidiabetics and insulin include increase in body weight and/or hypoglycemia that may limit its use in some patients. GLP-1 agonists are medicaments stimulating GLP-1 receptor similarly as endogenous GLP-1. These substances are in contrast to endogenous GLP-1 resistant to inactivation by ubiquitous enzyme dipeptidyl-peptidase 4 which enables its administration once or twice daily. GLP-1 agonists not only significantly improve diabetes compensation with minimal risk of hypoglycemia but also decrease body weight, blood pressure and improve numerous parameters of cardiovascular risk. The aim of this review is to summarize current knowledge with respect to use of GLP-1 agonists in the treatment of type 2 diabetes and its future perspectives. We will focus mostly on the two drugs that are currently available in Czech Republic--exenatide and liraglutide. Topics: Diabetes Mellitus, Type 2; Exenatide; Glucagon-Like Peptide 1; Humans; Incretins; Liraglutide; Peptides; Venoms | 2011 |
GLP-1 and energy balance: an integrated model of short-term and long-term control.
Glucagon-like peptide 1 (GLP-1), a peptide secreted from the intestine in response to nutrient ingestion, is perhaps best known for its effect on glucose-stimulated insulin secretion. GLP-1 is also secreted from neurons in the caudal brainstem, and it is well-established that, in rodents, central administration of GLP-1 potently reduces food intake. Over the past decade, GLP-1 has emerged not only as an essential component of the system that regulates blood glucose levels but also as a viable therapeutic target for the treatment of type 2 diabetes mellitus. However, although GLP-1 receptor agonists are known to produce modest but statistically significant weight loss in patients with diabetes mellitus, our knowledge of how endogenous GLP-1 regulates food intake and body weight remains limited. The purpose of this Review is to discuss the evolution of our understanding of how endogenous GLP-1 modulates energy balance. Specifically, we consider contributions of both central and peripheral GLP-1 and propose an integrated model of short-term and long-term control of energy balance. Finally, we discuss this model with respect to current GLP-1-based therapies and suggest ongoing research in order to maximize the effectiveness of GLP-1-based treatment of obesity. Topics: Animals; Blood Glucose; Diabetes Mellitus, Type 2; Eating; Energy Metabolism; Glucagon-Like Peptide 1; Glucagon-Like Peptide-1 Receptor; Humans; Hypoglycemic Agents; Insulin; Receptors, Glucagon | 2011 |
Glucagon-like peptide-1 receptor agonists versus insulin in inadequately controlled patients with type 2 diabetes mellitus: a meta-analysis of clinical trials.
To compare the effect and safety of glucagon-like peptide-1 receptor agonists (GLP-1 RA) with insulin therapy on type 2 diabetes mellitus (T2DM) patients inadequately controlled with metformin and/or sulfonylurea. A systematic literature search on MEDLINE, Embase and Cochrane for randomized controlled trials (RCTs) was conducted using specific search terms 'GLP-1 insulin type 2 diabetes clinical trials' and eight eligible studies were retrieved. Data on mean change in haemoglobin A1c (HbA1C), weight loss, fasting plasma glucose (FPG), incidence of hypoglycaemia and gastrointestinal adverse events were extracted from each study and pooled in meta-analysis. Data on postprandial plasma glucose (PPG) and adverse events were also described or tabulated. Data from eight RCTs enrolling 2782 patients were pooled using a random-effects model. The mean net change [95% confidence interval (CIs)] for HbA1c, weight loss and FPG for patients treated with GLP-1 RA as compared with insulin was -0.14% (-2 mmol/mol) [95% CI; (-0.27, -0.02)%; p = 0.03]; -4.40 kg [95% CI; (-5.23, -3.56) kg; p < 0.01] and 1.18 mmol/l [95% CI; (0.43, 1.93) mmol/l; p < 0.01], respectively, with negative values favouring GLP-1 and positive values favouring insulin. The GLP-1 group was associated with a greater reduction in PPG than the insulin group. Overall, hypoglycaemia was reported less in the GLP-1 group [Mantel-Haenszel odds ratio (M-H OR) 0.45 (0.27, 0.76); p < 0.01], while there was no significant difference in occurrence of severe hypoglycaemia [M-H OR 0.65 (0.29,1.45); p = 0.29]. A significantly higher number of gastrointestinal adverse events were reported with GLP-1 group [M-H OR 15.00 (5.44,41.35) p < 0.01]. GLP-1 RA are promising new agents compared with insulin. Further prospective clinical trials are expected to fully evaluate the long-term effectiveness and safety of these therapies within the T2DM treatment paradigm. Topics: Diabetes Mellitus, Type 2; Female; Glucagon-Like Peptide 1; Glucagon-Like Peptide-1 Receptor; Glycated Hemoglobin; Humans; Hypoglycemic Agents; Insulin; Male; Randomized Controlled Trials as Topic; Receptors, Glucagon | 2011 |
GLP-1 receptor agonists and HBA1c target of <7% in type 2 diabetes: meta-analysis of randomized controlled trials.
Glucagon-like peptide-1 (GLP-1) receptor agonists are available for the treatment of type 2 diabetes. We assessed the efficacy of exenatide and liraglutide to reach the HbA(1c) target of <7% in people with type 2 diabetes.. We conducted an electronic search for randomized controlled trials (RCTs) involving GLP-1 agonists through September 2010. RCTs were included if they lasted at least 12 weeks, included 30 patients or more, and reported the proportion of patients reaching the HbA(1c) target of <7%.. A total of 25 RCTs reporting 28 comparisons met the selection criteria, which included 9771 study participants evaluated for the primary endpoint, 5083 treated with a GLP-1 agonist and 4688 treated with placebo or a comparator drug. GLP-1 agonists showed a statistically significant reduction in HbA(1c) compared to placebo and the proportion of participants achieving the HbA(1c) goal <7% was 46% for exenatide, 47% for liraglutide, and 63% for exenatide LAR (long-acting release). Moreover, the reduction of the HbA(1c) level and the rate of HbA(1c) goal attainment were higher for both exenatide LAR and liraglutide, as compared to comparator drugs. Higher rates of hypoglycemia with exenatide b.i.d. and liraglutide compared to placebo were associated with the concomitant use of a sulfonylurea. Exenatide b.i.d. and liraglutide were associated with weight loss compared to placebo or other antidiabetic drugs. Baseline HbA(1c) was the best predictor for achievement of A1c target (overall weighted R(2) value = 0.513, p < 0.001).. A greater proportion of patients with type 2 diabetes can achieve the HbA(1c) goal <7% with GLP-1 agonists compared to placebo or other antidiabetic drugs; in absolute terms, exenatide LAR was best for the attainment of the HbA(1c) goal. Topics: Diabetes Mellitus, Type 2; Exenatide; Female; Glucagon-Like Peptide 1; Glucagon-Like Peptide-1 Receptor; Glycated Hemoglobin; Humans; Hypoglycemic Agents; Liraglutide; Male; Peptides; Randomized Controlled Trials as Topic; Receptors, Glucagon; Venoms | 2011 |
The emerging role of the intestine in metabolic diseases.
The intestine is an important metabolic organ that has gained attention in recent years for the newly identified role that it plays in the pathophysiology of various metabolic diseases including obesity, insulin resistance and diabetes. Recent insights regarding the role of enteroendocrine hormones, such as GIP, GLP-1, and PYY in metabolic diseases, as well as the emerging role of the gut microbial community and gastric bypass bariatric surgeries in modulating metabolic function and dysfunction have sparked a wave of interest in understanding the mechanisms involved, in an effort to identify new therapeutics and novel regulators of metabolism. This review summarizes the current evidence that the gastrointestinal tract has a key role in the development of obesity, inflammation, insulin resistance and diabetes and discusses the possible players that can be targeted for therapeutic intervention. Topics: Animals; Bariatric Surgery; Diabetes Mellitus, Type 2; Gastric Inhibitory Polypeptide; Gastrointestinal Hormones; Gastrointestinal Tract; Glucagon-Like Peptide 1; Humans; Inflammation; Insulin Resistance; Metabolic Diseases; Metagenome; Obesity; Peptide YY | 2011 |
Vildagliptin in the treatment of type 2 diabetes mellitus.
Inhibition of dipeptidyl peptidase IV (DPP-4) augments glucose-dependent insulin release and is a new approach to the treatment of type 2 diabetes (T2DM). Vildagliptin is a new DPP-4 inhibitor approved in many countries for the treatment of T2DM. This review provides an overview of vildagliptin with emphasis on its pharmacology and clinical effectiveness.. Results of preclinical and several Phase II and III studies from 2004 - 2010 are discussed.. Vildagliptin acts to inhibit the breakdown of glucagon-like peptide (GLP)-1, which in turn enhances the beta-cell response to glucose and inhibits glucagon secretion. It is an effective agent alone or in combination in patients with T2DM, resulting in modest improvements in HbA1c usually in the 0.5 - 1% range. Advantages include weight neutrality and a lesser incidence of hypoglycemia. Concerns remain regarding its use in renal disease and potential complications seen in animal models. Topics: Adamantane; Animals; Diabetes Mellitus, Type 2; Dipeptidyl-Peptidase IV Inhibitors; Drug Therapy, Combination; Glucagon-Like Peptide 1; Glycated Hemoglobin; Humans; Hyperglycemia; Hypoglycemia; Nitriles; Pyrrolidines; Vildagliptin | 2011 |
Management of type 2 diabetes: new and future developments in treatment.
The increasing prevalence, variable pathogenesis, progressive natural history, and complications of type 2 diabetes emphasise the urgent need for new treatment strategies. Longacting (eg, once weekly) agonists of the glucagon-like-peptide-1 receptor are advanced in development, and they improve prandial insulin secretion, reduce excess glucagon production, and promote satiety. Trials of inhibitors of dipeptidyl peptidase 4, which enhance the effect of endogenous incretin hormones, are also nearing completion. Novel approaches to glycaemic regulation include use of inhibitors of the sodium-glucose cotransporter 2, which increase renal glucose elimination, and inhibitors of 11β-hydroxysteroid dehydrogenase 1, which reduce the glucocorticoid effects in liver and fat. Insulin-releasing glucokinase activators and pancreatic-G-protein-coupled fatty-acid-receptor agonists, glucagon-receptor antagonists, and metabolic inhibitors of hepatic glucose output are being assessed. Early proof of principle has been shown for compounds that enhance and partly mimic insulin action and replicate some effects of bariatric surgery. Topics: 11-beta-Hydroxysteroid Dehydrogenase Type 1; Allylamine; Anticholesteremic Agents; Bariatric Surgery; Bile Acids and Salts; Cardiovascular System; Colesevelam Hydrochloride; Comorbidity; Diabetes Mellitus, Type 2; Dipeptidyl-Peptidase IV Inhibitors; Exenatide; Glucagon-Like Peptide 1; Glucokinase; Humans; Hyperglycemia; Hypoglycemic Agents; Indoles; Insulin; Insulin Resistance; Insulin-Secreting Cells; Liver; Obesity; Peptides; Randomized Controlled Trials as Topic; Receptors, Dopamine D2; Signal Transduction; Sodium-Glucose Transporter 2 Inhibitors; Treatment Outcome; Venoms | 2011 |
Type 2 diabetes across generations: from pathophysiology to prevention and management.
Type 2 diabetes is now a pandemic and shows no signs of abatement. In this Seminar we review the pathophysiology of this disorder, with particular attention to epidemiology, genetics, epigenetics, and molecular cell biology. Evidence is emerging that a substantial part of diabetes susceptibility is acquired early in life, probably owing to fetal or neonatal programming via epigenetic phenomena. Maternal and early childhood health might, therefore, be crucial to the development of effective prevention strategies. Diabetes develops because of inadequate islet β-cell and adipose-tissue responses to chronic fuel excess, which results in so-called nutrient spillover, insulin resistance, and metabolic stress. The latter damages multiple organs. Insulin resistance, while forcing β cells to work harder, might also have an important defensive role against nutrient-related toxic effects in tissues such as the heart. Reversal of overnutrition, healing of the β cells, and lessening of adipose tissue defects should be treatment priorities. Topics: Adipose Tissue; Animals; Blood Glucose; Diabetes Mellitus, Type 2; Diabetes, Gestational; Diabetic Retinopathy; Epigenesis, Genetic; Female; Fetal Development; Genetic Predisposition to Disease; Glucagon; Glucagon-Like Peptide 1; Homeostasis; Humans; Incretins; Insulin Resistance; Insulin-Secreting Cells; Life Style; Liver; Muscle, Skeletal; Myocardium; Obesity; Prediabetic State; Pregnancy | 2011 |
Combining basal insulin analogs with glucagon-like peptide-1 mimetics.
Basal insulin analogs are recognized as an effective method of achieving and maintaining glycemic control for patients with type 2 diabetes. However, the progressive nature of the disease means that some individuals may require additional ways to maintain their glycemic goals. Intensification in these circumstances has traditionally been achieved by the addition of short-acting insulin to cover postprandial glucose excursions that are not targeted by basal insulin. However, intensive insulin regimens are associated with a higher risk of hypoglycemia and weight gain, which can contribute to a greater burden on patients. The combination of basal insulin with a glucagon-like peptide-1 (GLP-1) mimetic is a potentially attractive solution to this problem for some patients with type 2 diabetes. GLP-1 mimetics target postprandial glucose and should complement the activity of basal insulins; they are also associated with a relatively low risk of associated hypoglycemia and moderate, but significant, weight loss. Although the combination has not been approved by regulatory authorities, preliminary evidence from mostly small-scale studies suggests that basal insulins in combination with GLP-1 mimetics do provide improvements in A1c and postprandial glucose with concomitant weight loss and no marked increase in the risk of hypoglycemia. These results are promising, but further studies are required, including comparisons with basal-bolus therapy, before the complex value of this association can be fully appreciated. Topics: Diabetes Mellitus, Type 2; Disease Progression; Drug Therapy, Combination; Glucagon-Like Peptide 1; Humans; Hyperglycemia; Hypoglycemia; Hypoglycemic Agents; Insulin; Weight Gain | 2011 |
[Weight reducing and glucose reducing effects of liraglutide treatment for patients with type 2 diabetes].
Treatment with glucagon-like peptide-1 analogues including liraglutide is a new treatment option for patients with type 2 diabetes. Treatment with liraglutide decreases HbA1c by 1-2%, and additionally liraglutide has a reducing effect on weight, lipids and blood pressure. Most adverse events are related to the gastrointestinal system and most often they disappear within a few weeks. The risk of major hypoglycaemic episodes is minimal. Long term data on treatment and adverse events with liraglutide are still lacking. Topics: Blood Glucose; Blood Pressure; Body Weight; Diabetes Mellitus, Type 2; Drug Therapy, Combination; Glucagon-Like Peptide 1; Glycated Hemoglobin; Humans; Hypoglycemic Agents; Lipids; Liraglutide; Treatment Outcome | 2011 |
Efficacy and safety of long-acting glucagon-like peptide-1 receptor agonists compared with exenatide twice daily and sitagliptin in type 2 diabetes mellitus: a systematic review and meta-analysis.
Long-acting glucagon-like peptide-1 receptor agonists (LA-GLP-1RAs) may deliver additional therapeutic benefits over other available incretin-based therapies.. To pool results of randomized controlled trials comparing the efficacy and safety of maximum dose LA-GLP-1RAs (liraglutide, exenatide once weekly) with exenatide twice daily and dipeptidyl-peptidase-IV inhibitors in patients with type 2 diabetes.. We searched PubMed, Cochrane Central Register of Controlled Trials and Database of Systematic Reviews, EMBASE (all from inception-December 2010), and abstracts presented at the American Diabetes Association Scientific Sessions in 2009 and 2010 to identify English-language reports of studies of at least 24 weeks' duration. The primary endpoint was mean change in hemoglobin A(1c) (A1C) from baseline to study endpoint. Weighted mean differences or odds ratios and their 95% confidence intervals for each outcome relative to control were calculated as appropriate.. A1C was reduced favoring LA-GLP-1RAs compared with exenatide twice daily and sitagliptin (weighted mean difference [WMD] -0.47% [95% CI -0.69 to -0.25] and WMD -0.60% [95% CI -0.75 to -0.45], respectively). Odds ratios greater than 1 favored LA-GLP-1RAs for reaching the A1C target goal of less than 7%. Fasting plasma glucose (FPG) was reduced and favored the LA-GLP-1RA-based regimens. Exenatide demonstrated significantly greater reductions in postprandial glucose (PPG) after the morning and evening meals, compared with LA-GLP-1RAs. Body weight was reduced similarly between LA-GLP-1RAs and exenatide, but favored LA-GLP-1RAs in the sitagliptin comparator trials. LA-GLP-1RA therapy was not associated with severe hypoglycemia or acute pancreatitis. Compared with exenatide twice daily, vomiting was reduced significantly with LA-GLP-1RAs (OR 0.55; 95% CI 0.34 to 0.89); there was a trend toward decreased nausea (OR 0.58; 95% CI 0.32 to 1.06) and no difference in the incidence of diarrhea (OR 1.03; 95% CI 0.67 to 1.58).. Compared with other incretin-based therapies, LA-GLP-1RAs produce greater improvement in A1C and FPG. They provide lesser effect on PPG, similar reduction in body weight, and result in a potentially favorable adverse event profile compared with exenatide twice daily. Topics: Delayed-Action Preparations; Diabetes Mellitus, Type 2; Dipeptidyl-Peptidase IV Inhibitors; Exenatide; Female; Glucagon-Like Peptide 1; Glucagon-Like Peptide-1 Receptor; Glycated Hemoglobin; Humans; Hyperglycemia; Hypoglycemic Agents; Incretins; Liraglutide; Male; Middle Aged; Peptides; Pyrazines; Randomized Controlled Trials as Topic; Receptors, Glucagon; Sitagliptin Phosphate; Triazoles; Venoms | 2011 |
The safety of incretin-based therapies--review of the scientific evidence.
Antidiabetic therapies based on potentiation of incretin action are now widely used; however, understanding of their long-term safety remains incomplete.. We searched articles in PubMed for data assessing the safety of incretin-based therapies.. Three major areas of interest are reviewed: incretin action in the cardiovascular system, pancreatitis, and cancer. Incretin therapies reduce weight gain, minimize hypoglycemia, decrease inflammation, and are cardioprotective in preclinical studies. However, data permitting conclusions about whether incretin therapies modify the development of cardiovascular events in humans are not available. Case reports link incretin therapies to pancreatitis, but retrospective case control studies do not associate pancreatitis with glucagon-like peptide-1 receptor (GLP-1R) agonists or dipeptidyl peptidase-4 inhibitors. Preclinical studies of pancreatitis have yielded conflicting results, and mechanisms linking incretin receptor activation to pancreatic inflammation have not yet been forthcoming. GLP-1R activation promotes C-cell hyperplasia and medullary thyroid cancer in rodents; however, long-term clinical studies of sufficient size and duration to permit conclusions regarding cancer and incretin therapeutics have not yet been completed.. The available data on incretin action and incidence of cardiovascular events, pancreatitis, or cancer are not yet sufficient or robust enough to permit firm conclusions regarding associations with incretin-based therapies in humans with diabetes. The forthcoming results of long-term cardiovascular safety studies should provide more conclusive information about the safety of GLP-1R agonists and dipeptidyl peptidase-4 inhibitors in diabetic patients. Topics: Diabetes Mellitus, Type 2; Dipeptidyl-Peptidase IV Inhibitors; Glucagon-Like Peptide 1; Humans; Hypoglycemic Agents | 2011 |
Review of the therapeutic uses of liraglutide.
Glucagon-like peptide (GLP-1) is a neuroendocrine hormone that increases blood glucose and is a drug target for treatment of type 2 diabetes. Liraglutide, a subcutaneous, once-daily GLP-1 agonist, is approved for the treatment of type 2 diabetes in the United States and Europe. It also has been studied for weight loss.. The purpose of this article is to review all of the relevant literature on the chemistry, pharmacology, pharmacokinetics, metabolism, clinical trials, safety, drug interactions, cost, and place in therapy of liraglutide.. Literature searches of MEDLINE between 1969 and September 2010, International Pharmaceutical Abstracts between 1970 and September 2010, American Diabetes Association Meeting abstracts (2008-2010), and European Association for the Study of Diabetes abstracts (2008-2010) were performed using liraglutide, Victoza, and NN2211 as key terms.. Thirteen randomized controlled trials were identified and summarized. Liraglutide has been shown to increase glucose-dependent insulin release by 34% to 118% and reduce postprandial glucagon levels by 20%. Studies showed that liraglutide, as monotherapy and in combination with glimepiride, metformin, and/or rosiglitazone, lowers glycosylated hemoglobin (HbA(1c)) between 0.84% and 1.5%. Transient nausea was reported by 7% to 40% of subjects. Severe hypoglycemia-glucose <55 mg/dL-was observed by 2.5% of subjects in 1 trial.. Liraglutide safely and effectively reduces HbA(1c) in patients with type 2 diabetes. The most recent American Diabetes Association guidelines recommended a GLP-1 agonist along with metformin as a second-tier therapy for type 2 diabetes. Although the American Association of Clinical Endocrinologists/American College of Endocrinologists' guidelines recommended it for first-line monotherapy in patients with HbA(1c) between 6.5% and 7.5% and with metformin if HbA(1c) is between 7.6% and 8.5%, liraglutide should be considered for patients who cannot tolerate first-line agents or if an additional agent is needed to help reach target HbA(1c) goals. Topics: Animals; Blood Glucose; Diabetes Mellitus, Type 2; Glucagon-Like Peptide 1; Glycated Hemoglobin; Humans; Hypoglycemic Agents; Liraglutide; Practice Guidelines as Topic; Randomized Controlled Trials as Topic | 2011 |
Effects of GLP-1 and incretin-based therapies on gastrointestinal motor function.
Glucagon-like peptide 1 (GLP-1) is a hormone secreted predominantly by the distal small intestine and colon and released in response to enteral nutrient exposure. GLP-1-based therapies are now used widely in the management of type 2 diabetes and have the potential to be effective antiobesity agents. Although widely known as an incretin hormone, there is a growing body of evidence that GLP-1 also acts as an enterogastrone, with profound effects on the gastrointestinal motor system. Moreover, the effects of GLP-1 on gastrointestinal motility appear to be pivotal to its effect of reducing postprandial glycaemic excursions and may, potentially, represent the dominant mechanism. This review summarizes current knowledge of the enterogastrone properties of GLP-1, focusing on its effects on gut motility at physiological and pharmacological concentrations, and the motor actions of incretin-based therapies. While of potential importance, the inhibitory action of GLP-1 on gastric acid secretion is beyond the scope of this paper. Topics: Animals; Diabetes Mellitus, Type 2; Gastrointestinal Hormones; Gastrointestinal Motility; Gastrointestinal Tract; Glucagon-Like Peptide 1; Humans; Incretins; Movement; Peptides | 2011 |
Glucagon-like peptide-1, diabetes, and cognitive decline: possible pathophysiological links and therapeutic opportunities.
Metabolic and neurodegenerative disorders have a growing prevalence in Western countries. Available epidemiologic and neurobiological evidences support the existence of a pathophysiological link between these conditions. Glucagon-like peptide 1 (GLP-1), whose activity is reduced in insulin resistance, has been implicated in central nervous system function, including cognition, synaptic plasticity, and neurogenesis. We review the experimental researches suggesting that GLP-1 dysfunction might be a mediating factor between Type 2 diabetes mellitus (T2DM) and neurodegeneration. Drug treatments enhancing GLP-1 activity hold out hope for treatment and prevention of Alzheimer's disease (AD) and cognitive decline. Topics: Animals; Cognition Disorders; Diabetes Mellitus, Type 2; Endocrinology; Glucagon-Like Peptide 1; Humans; Insulin Resistance; Nerve Degeneration; Therapies, Investigational | 2011 |
Targeting amyloid-beta by glucagon-like peptide -1 (GLP-1) in Alzheimer's disease and diabetes.
Epidemiological evidence suggests an association between type 2 diabetes (T2DM) and Alzheimer's disease (AD), in that one disease increases the risk of the other. T2DM and AD share several molecular processes which underlie the tissue degeneration in either disease. Disturbances in insulin signaling may be the link between the two conditions. Drugs originally developed for T2DM are currently being considered as possible novel agents in the treatment of AD.. This review discusses the potential role of glucagon-like peptide -1 (GLP-1) treatment in AD. GLP-1 receptors are expressed in areas of the brain important to memory and learning, and GLP-1 has growth-factor-like properties similar to insulin. A key neuropathological feature of AD is the accumulation of amyloid-beta (Aβ). In preclinical studies, GLP-1 and longer lasting analogues have been shown to have both neuroprotective and neurotrophic effects, and to protect synaptic activity in the brain from Aβ toxicity.. A convincing amount of evidence has shown a beneficial effect of GLP-1 agonist treatment on cognitive function, memory and learning in experimental models of AD. GLP-1 analogues may therefore be the new therapeutic agent of choice for intervention in AD. Topics: Alzheimer Disease; Amyloid beta-Peptides; Animals; Cognition; Diabetes Mellitus, Type 2; Glucagon-Like Peptide 1; Humans; Learning; Memory; Neuroprotective Agents; Rats | 2011 |
Emerging role of dipeptidyl peptidase-IV (DPP-4) inhibitor vildagliptin in the management of type 2 diabetes.
Diabetes mellitus (DM) is one of the most common chronic disorders, with increasing prevalence worldwide. Type 2 diabetes (T2DM), a multifaceted disease involving multiple pathophysiological defects, accounts for nearly 85-95% of total reported cases of DM. Chances of developing T2DM are increased by obesity and physical inactivity and are augmented further with age. Two most important unmet needs associated with the management of T2DM are the lack of lasting efficacy in reducing hyperglycemia and failure to target primary causes. Different classes of Oral Hypoglycemic Agents (OHA's) with nearly equipotent efficacy are now available targeting the different pathophysiologic factors contributing to T2DM; however, almost all of them are associated with one or the other kind of adverse effect. Several studies have found that certain diabetes drugs may carry increased cardiovascular (CV) risks compared to others. The new approach in management of T2DM based upon the effects of incretin hormones; Glucagon-like peptide-1 (GLP-1) and glucose-dependent insulinotropic peptide (GIP). Vildagliptin is a drug from a new class of medications called dipeptidyl peptidase IV (DPP4) inhibitors. By inhibiting DPP-4, vildagliptin causes an increase in GLP-1, an intestinal hormone that aids in glucose homeostasis and insulin secretion. Vildagliptin has a half-life of about 90 minutes; however, > or = 50% of DPP4 inhibition continues for more than 10 hours, allowing for once- or twice-daily dosing. Clinical trials have shown that vildagliptin is effective in significantly lowering glycosylated hemoglobin (HbA1c), fasting plasma glucose, and prandial glucose levels. beta-cell function may also be improved. The drug has placebo like tolerability and rate of hypoglycemia events. Vildagliptin expands non-injectable treatment options available for management of T2DM patients, who are poorly controlled with monotherapy. Topics: Adamantane; Blood Glucose; Clinical Trials as Topic; Diabetes Mellitus, Type 2; Dipeptidyl-Peptidase IV Inhibitors; Glucagon-Like Peptide 1; Glycated Hemoglobin; Half-Life; Humans; Hypoglycemic Agents; Incretins; Insulin-Secreting Cells; Nitriles; Pyrrolidines; Vildagliptin | 2011 |
GLP-1 receptor agonists today.
Type 2 diabetes mellitus (T2DM) is a complex, progressive disease affecting an estimated 257 million people worldwide. A number of unmet needs exist with traditional T2DM therapies, which can lead to insufficient glycaemic control and increased risk of diabetes-associated complications. An emerging class of diabetes therapeutics, the glucagon-like peptide-1 (GLP-1) receptor agonists, appear to address many of the unmet needs of patients with T2DM. This review summarises the recent findings and current clinical guidelines of the currently approved GLP-1 receptor agonists and explores the new GLP-1 receptor agonists in development. It also concentrates on the physiological basis for early use of GLP-1 receptor agonists, their use as an alternative to insulin therapy, the rationale for combining them with insulin and their cost-effectiveness. Topics: Animals; Diabetes Mellitus, Type 2; Exenatide; Glucagon-Like Peptide 1; Glucagon-Like Peptide-1 Receptor; Humans; Hypoglycemic Agents; Liraglutide; Peptides; Receptors, Glucagon; Venoms | 2011 |
Molecular physiology of glucagon-like peptide-1 insulin secretagogue action in pancreatic β cells.
Insulin secretion from pancreatic β cells is stimulated by glucagon-like peptide-1 (GLP-1), a blood glucose-lowering hormone that is released from enteroendocrine L cells of the distal intestine after the ingestion of a meal. GLP-1 mimetics (e.g., Byetta) and GLP-1 analogs (e.g., Victoza) activate the β cell GLP-1 receptor (GLP-1R), and these compounds stimulate insulin secretion while also lowering levels of blood glucose in patients diagnosed with type 2 diabetes mellitus (T2DM). An additional option for the treatment of T2DM involves the administration of dipeptidyl peptidase-IV (DPP-IV) inhibitors (e.g., Januvia, Galvus). These compounds slow metabolic degradation of intestinally released GLP-1, thereby raising post-prandial levels of circulating GLP-1 substantially. Investigational compounds that stimulate GLP-1 secretion also exist, and in this regard a noteworthy advance is the demonstration that small molecule GPR119 agonists (e.g., AR231453) stimulate L cell GLP-1 secretion while also directly stimulating β cell insulin release. In this review, we summarize what is currently known concerning the signal transduction properties of the β cell GLP-1R as they relate to insulin secretion. Emphasized are the cyclic AMP, protein kinase A, and Epac2-mediated actions of GLP-1 to regulate ATP-sensitive K⁺ channels, voltage-dependent K⁺ channels, TRPM2 cation channels, intracellular Ca⁺ release channels, and Ca⁺-dependent exocytosis. We also discuss new evidence that provides a conceptual framework with which to understand why GLP-1R agonists are less likely to induce hypoglycemia when they are administered for the treatment of T2DM. Topics: Animals; Diabetes Mellitus, Type 2; Glucagon-Like Peptide 1; Humans; Incretins; Insulin; Insulin Secretion; Insulin-Secreting Cells | 2011 |
The development of non-peptide glucagon-like peptide-1 receptor agonist for the treatment of type 2 diabetes.
Glucagon-like peptide-1 (GLP-1) is the main member of the incretin family and stimulates insulin secretion by binding with its specific receptor on pancreatic β-cells. In addition, GLP-1 exerts broad beneficial effects on the glucose regulation by suppressing food intake and delaying stomach emptying. Now, long acting GLP-1 analogs including exenatide and liraglutide have been approved for the treatment of diabetes mellitus type 2, however long-term injection can limit their use for these chronic patients. In this report, the authors provide a review on the development of non-peptide GLP-1 receptor agonists and introduce a novel agonist DA-15864. Topics: Animals; Diabetes Mellitus, Type 2; Drug Design; Glucagon-Like Peptide 1; Glucagon-Like Peptide-1 Receptor; Humans; Hypoglycemic Agents; Insulin; Insulin-Secreting Cells; Molecular Targeted Therapy; Rats; Receptors, Glucagon | 2011 |
Novel incretin-based agents and practical regimens to meet needs and treatment goals of patients with type 2 diabetes mellitus.
As knowledge of pathophysiologic mechanisms of diabetes mellitus has increased, clinical attention has shifted to the incretin system. Incretin hormones, including glucagon-like peptide-1, or GLP-1, and glucose-dependent insulinotropic polypeptide, are vital to the control of glucose homeostasis and pancreatic β-cell preservation. Novel strategies for the treatment of patients with type 2 diabetes mellitus (T2DM) engage the incretin system. Glucagon-like peptide-1 receptor agonists provide robust glycemic control as well as beneficial reductions in body weight. Dipeptidyl peptidase-4, or DPP-4, inhibitors exhibit beneficial glycemic effects and are weight-neutral. Incretin-based medications are becoming increasingly recognized in guidelines as early treatment options because of their efficacy and well-tolerated profiles. The author reviews the safety and efficacy of currently approved incretin-based agents, as well as the role of these medications in treatment paradigms for patients with T2DM. He also discusses investigational incretin-based agents. Topics: Adult; Aged; Blood Glucose; Diabetes Mellitus, Type 2; Dipeptidyl-Peptidase IV Inhibitors; Dose-Response Relationship, Drug; Drug Administration Schedule; Female; Follow-Up Studies; Glucagon-Like Peptide 1; Humans; Incretins; Linagliptin; Male; Middle Aged; Purines; Quinazolines; Randomized Controlled Trials as Topic; Severity of Illness Index; Treatment Outcome | 2011 |
Two incretin hormones GLP-1 and GIP: comparison of their actions in insulin secretion and β cell preservation.
Gastric inhibitory polypeptide (GIP) and glucagon-like peptide-1 (GLP-1) are the two primary incretin hormones secreted from the intestine upon ingestion of glucose or nutrients to stimulate insulin secretion from pancreatic β cells. GIP and GLP-1 exert their effects by binding to their specific receptors, the GIP receptor (GIPR) and the GLP-1 receptor (GLP-1R), which belong to the G-protein coupled receptor family. Receptor binding activates and increases the level of intracellular cAMP in pancreatic β cells, thereby stimulating insulin secretion glucose-dependently. In addition to their insulinotropic effects, GIP and GLP-1 have been shown to preserve pancreatic β cell mass by inhibiting apoptosis of β cells and enhancing their proliferation. Due to such characteristics, incretin hormones have been gaining mush attention as attractive targets for treatment of type 2 diabetes, and indeed incretin-based therapeutics have been rapidly disseminated worldwide. However, despites of plethora of rigorous studies, molecular mechanisms underlying how GIPR and GLP-1R activation leads to enhancement of glucose-dependent insulin secretion are still largely unknown. Here, we summarize the similarities and differences of these two incretin hormones in secretion and metabolism, their insulinotropic actions and their effects on pancreatic β cell preservation. We then try to discuss potential of GLP-1 and GIP in treatment of type 2 diabetes. Topics: Animals; Diabetes Mellitus, Type 2; Gastric Inhibitory Polypeptide; Glucagon-Like Peptide 1; Humans; Incretins; Insulin; Insulin Secretion; Insulin-Secreting Cells | 2011 |
Growth factor signalling in the regulation of α-cell fate.
Glucagon plays critical roles in regulating glucose homeostasis, mainly by counteracting the effects of insulin. Consequently, the dysregulated glucagon secretion that is evident in type 2 diabetes has significant implications in the pathophysiology of the disease. Glucagon secretion from pancreatic α-cells has been suggested to be modulated by blood glucose, signals from the nervous system and endocrine components. In addition to these regulators, intraislet factors acting in a paracrine manner from neighbouring β-cells are emerging as central modulator(s) of α-cell biology. One of the most important of these paracrine factors, insulin, modulates glucagon secretion. Indeed, the α-cell-specific insulin receptor knockout (αIRKO) mouse manifests hypersecretion of glucagon in the postprandial stage and exhibits defective secretion in fasting-induced hypoglycaemia, together mimicking the α-cell defects observed in type 2 diabetes. Interestingly, αIRKO mice display a progressive increase in β-cell mass and a concomitant decrease in α-cells. Lineage trace analyses reveal that the new β-cells originate, in part, from the insulin receptor-deficient α-cells indicating a critical role for α-cell insulin signalling in determining β-cell origin. Our studies also reveal that glucagon-like peptide-1 (GLP-1) treatment of αIRKO mice suppresses glucagon secretion despite absence of functional insulin receptors precluding a role for insulin in GLP-1 action on α-cells in this model. These findings highlight the significance of insulin signalling in the regulation of α-cell biology. Topics: Animals; Blood Glucose; Diabetes Mellitus, Experimental; Diabetes Mellitus, Type 2; Gene Expression Regulation; Glucagon; Glucagon-Like Peptide 1; Glucagon-Secreting Cells; Humans; Mice; Mice, Knockout; Signal Transduction | 2011 |
Regulation of glucagon secretion by incretins.
Glucagon secretion plays an essential role in the regulation of hepatic glucose production, and elevated fasting and postprandial plasma glucagon concentrations in patients with type 2 diabetes (T2DM) contribute to their hyperglycaemia. The reason for the hyperglucagonaemia is unclear, but recent studies have shown lack of suppression after oral but preserved suppression after isoglycaemic intravenous glucose, pointing to factors from the gut. Gastrointestinal hormones that are secreted in response to oral glucose include glucagon-like peptide-1 (GLP-1) that strongly inhibits glucagon secretion, and GLP-2 and GIP, both of which stimulate secretion. When the three hormones are given together on top of isoglycaemic intravenous glucose, glucagon suppression is delayed in a manner similar to that observed after oral glucose. Studies with the GLP-1 receptor antagonist, exendin 9-39, suggest that endogenous GLP-1 plays an important role in regulation of glucagon secretion during fasting as well as postprandially. The mechanisms whereby GLP-1 regulates glucagon secretion are debated, but studies in isolated perfused rat pancreas point to an important role for a paracrine regulation by somatostatin from neighbouring D cells. Clinical studies of the antidiabetic effect of GLP-1 in T2DM suggest that the inhibition of glucagon secretion is as important as the stimulation of insulin secretion. Topics: Animals; Diabetes Mellitus, Experimental; Diabetes Mellitus, Type 2; Glucagon; Glucagon-Like Peptide 1; Glucagon-Like Peptide-1 Receptor; Humans; Incretins; Rats; Receptors, Glucagon | 2011 |
The role of dysregulated glucagon secretion in type 2 diabetes.
Excessive production of glucose by the liver contributes to fasting and postprandial hyperglycaemia, hallmarks of type 2 diabetes. A central feature of this pathologic response is insufficient hepatic insulin action, due to a combination of insulin resistance and impaired β-cell function. However, a case can be made that glucagon also plays a role in dysregulated hepatic glucose production and abnormal glucose homeostasis. Plasma glucagon concentrations are inappropriately elevated in diabetic individuals, and α-cell suppression by hyperglycaemia is blunted. Experimental evidence suggests that this contributes to greater rates of hepatic glucose production in the fasting state and attenuated reduction after meals. Recent studies in animal models indicate that reduction of glucagon action can have profound effects to mitigate hyperglycaemia even in the face of severe hypoinsulinaemia. While there are no specific treatments for diabetic patients yet available that act specifically on the glucagon signalling pathway, newer agents including glucagon-like peptide-1 (GLP-1) receptor agonists and dipeptidyl peptidase-4 (DPP-4) inhibitors reduce plasma glucagon and this is thought to contribute to their action to lower blood glucose. The α-cell and glucagon receptor remain tempting targets for novel diabetes treatments, but it is important to understand the magnitude of benefit new strategies would provide as preclinical models suggest that chronic interference with glucagon action could entail adverse effects as well. Topics: Animals; Blood Glucose; Diabetes Mellitus, Experimental; Diabetes Mellitus, Type 2; Dipeptidyl-Peptidase IV Inhibitors; Fasting; Glucagon; Glucagon-Like Peptide 1; Glucagon-Secreting Cells; Humans; Hyperglycemia; Insulin-Secreting Cells; Liver; Mice | 2011 |
The future of incretin-based therapy: novel avenues--novel targets.
Incretin-based therapy for type 2 diabetes is based on the antidiabetic effects of glucagon-like peptide-1 (GLP-1) and instituted by GLP-1 receptor agonists and dipeptidyl peptidase-4 inhibitors targeting the key islet defects of the disease. The treatment is clinically efficient and safe, and associated with a low risk of adverse events. It can be used both in early and late stages of the disease and both as monotherapy and add-on to other therapies. Current research on the future of incretin-based therapy focuses on optimizing its place in diabetes treatment and examines its potential in type 1 diabetes, in subjects with obesity without type 2 diabetes and in cardiovascular and neurodegenerative disorders. Other studies aim at prolonging the duration of action of the GLP-1 receptor agonists to allow weekly administration, and to develop orally GLP-1 receptor agonists. Furthermore, other investigators focus on stimulation of GLP-1 secretion by activating GLP-1-producing L-cells or using gene therapy. Finally, also other gastro-entero-pancreatic bioactive peptides are potential targets for drug development as are synthetic peptides engineered as co-agonists stimulating more than one receptor. We can therefore expect a dynamic development within this field in the coming years. Topics: Diabetes Mellitus, Type 2; Dipeptidyl-Peptidase IV Inhibitors; Glucagon-Like Peptide 1; Glucagon-Like Peptide-1 Receptor; Humans; Hypoglycemic Agents; Incretins; Receptors, Glucagon | 2011 |
Pharmacological management of type 2 diabetes mellitus: an update.
While lifestyle modifications and metformin are the cornerstone of the initial management of type 2 diabetes mellitus, there is an increasing array of second and third-line pharmacological agents for this condition. These include sulphonylureas, insulin, thiazolidinediones and alpha-glucosidase inhibitors, with the more recent addition of glucagon- like peptide-1 agonists, dipeptidyl peptidase-IV inhibitors and pramlintide. Moreover, insulin analogues that better simulate endogenous insulin secretion have been developed. This review aims to provide an update on the current pharmacological management of type 2 diabetes mellitus, and to highlight the benefits and limitations of each treatment. Topics: Diabetes Mellitus, Type 2; Dipeptidyl-Peptidase IV Inhibitors; Enzyme Inhibitors; Glucagon-Like Peptide 1; Glycoside Hydrolase Inhibitors; Humans; Hypoglycemic Agents; Insulin; Islet Amyloid Polypeptide; Sulfonylurea Compounds; Thiazolidinediones; Treatment Outcome | 2011 |
Incretin effect: GLP-1, GIP, DPP4.
The term incretin effect was used to describe the fact that oral glucose load produces a greater insulin response than that of an isoglycemic intravenous glucose infusion. This difference has been attributed to gastrointestinal peptides GLP-1 and GIP. Since incretin effect is reduced in subjects with type 2 diabetes, despite GLP-1 activity preservation, two forms of incretin-based treatment have emerged: GLP-1R agonists, administered subcutaneously and DPP-4 inhibitors, administered orally. There is a great interest whether incretin-based treatment will be associated with sustained long-term control and improvement in β-cell function. The observation that GLP-1R agonists improve myocardial function and survival of cardiomyocytes highlights the need for further studies. Incretin-based therapies offer a new option and show great promise for the treatment of type 2 diabetes. Topics: Animals; Diabetes Mellitus, Type 2; Dipeptidyl-Peptidase IV Inhibitors; Exenatide; Gastric Inhibitory Polypeptide; Glucagon-Like Peptide 1; Glucagon-Like Peptide-1 Receptor; Humans; Hypoglycemic Agents; Incretins; Insulin-Secreting Cells; Peptides; Receptors, Glucagon; Venoms | 2011 |
Beyond glucose lowering: glucagon-like peptide-1 receptor agonists, body weight and the cardiovascular system.
Glucagon-like peptide-1 (GLP-1) belongs to the incretin hormone family: in the presence of elevated blood glucose, it stimulates insulin secretion and inhibits glucagon production. In addition, GLP-1 slows gastric emptying. GLP-1 secretion has also been reported to potentially affect patients with type 2 diabetes (T2DM) compared with non-diabetics and, as enzymatic inactivation by dipeptidyl peptidase-4 (DPP-4) shortens the GLP-1 half-life to a few minutes, GLP-1 receptor agonists such as exenatide twice daily (BID) and liraglutide have been developed, and have become part of the management of patients with T2DM. This review focuses on the potential beneficial effects of these compounds beyond those associated with improvements in blood glucose control and weight loss, including changes in the cardiovascular and central nervous systems.. This was a state-of-the-art review of the literature to evaluate the relationships between GLP-1, GLP-1 receptor agonists, weight and the cardiovascular system.. GLP-1 receptor agonists improve glucose control and do not significantly increase the risk of hypoglycaemia. Also, this new class of antidiabetic drugs was shown to favour weight loss. Mechanisms may involve central action, direct action by reduction of food intake and probably indirect action through slowing of gastric emptying. The relative importance of each activity remains unclear. Weight loss may improve cardiovascular outcomes in patients with T2DM, although GLP-1 receptor agonists may have other direct and indirect effects on the cardiovascular system. Reductions in myocardial infarct size and improvements in cardiac function have been seen in animal models. Beneficial changes in cardiac function were also demonstrated in patients with myocardial infarcts or heart failure. Indirect effects could involve a reduction in blood pressure and potential effects on oxidation. However, the mechanisms involved in the pleiotropic effects of GLP-1 receptor agonists have yet to be completely elucidated and require further study.. These compounds may play an important role in the treatment of patients with T2DM as their potential effects go beyond glucose-lowering (weight loss, potential improvement of cardiovascular risk factors). However, to better understand their place in the management of T2DM, further experimental and clinical prospective studies are required. Topics: Body Weight; Cardiovascular System; Diabetes Mellitus, Type 2; Diabetic Angiopathies; Dipeptidyl Peptidase 4; Dipeptidyl-Peptidase IV Inhibitors; Exenatide; Glucagon-Like Peptide 1; Glucagon-Like Peptide-1 Receptor; Half-Life; Humans; Hypoglycemic Agents; Liraglutide; Peptides; Receptors, Glucagon; Venoms | 2011 |
Place in therapy for liraglutide and saxagliptin for type 2 diabetes.
The release of incretin based therapeutic entities has brought the possibility to offer control of the disease by augmenting a natural process in the body that has become deficient with type 2 diabetes. Liraglutide, an incretin mimetic, and saxagliptin, a dipeptidyl peptidase-4 inhibitor, have been approved and introduced to the market.. To (a) review the efficacy and safety data of for the treatment of type 2 diabetes, and (b) recommend their place in therapy.. A MEDLINE search was performed using key words "liraglutide" and "saxagliptin" for articles published and available through July 2010.. The Liraglutide Effect and Action in Diabetes (LEAD) trials encompassed six published phase 3 trials that evaluated the efficacy and safety of liraglutide either as monotherapy or in addition to oral hypoglycemic medications. Saxagliptin has been studied as monotherapy and in combination to oral hypoglycemic medications.. Liraglutide has been shown to improve glucose control and weight loss compared to other pharmacologic treatments with diabetes and may offer improved control with a decrease in daily dosing compared to exenatide. Saxagliptin improved glucose control as monotherapy or in combination with medications other than sulfonylurea. Saxagliptin has not been evaluated head to head with sitagliptin other than in combination with metformin where saxagliptin was deemed noninferior. Given the lack of long-term safety and clinical data compared to current treatment modalities, and more importantly the overall cost of the therapies to the health care system, a global recommendation for their use cannot be issued. Topics: Adamantane; Diabetes Mellitus, Type 2; Dipeptides; Dipeptidyl-Peptidase IV Inhibitors; Glucagon-Like Peptide 1; Humans; Incretins; Liraglutide | 2011 |
Recent diabetes issues affecting the primary care clinician.
Diabetes accounts for millions of office visits each year to primary care offices in the United States. Successful care of the patient with type 2 diabetes requires not only focus on glucose management but also on comorbidities such as hypertension, dyslipidemia and obesity which are closely linked to microvascular and macrovascular complications. Primary care clinicians must stay abreast of frequently published diabetes literature and new treatments to care for these increasingly complex patients. Metformin and its effect on B12 absorption continues to be an issue encountered by clinicians in daily clinical practice. There has also been recent discussion regarding the increased risk of diabetes with statins; data to date on this issue have been conflicting. Rosiglitazone continues to face public scrutiny and there are now Food and Drug Administration regulations regarding its increased risk of cardiovascular disease. Liraglutide and saxagliptin represent new treatment options for type 2 diabetes, increasing the available options for treating this complex disease. A review of the primary literature involving these topics is provided. Topics: Adamantane; Cardiovascular Diseases; Diabetes Mellitus, Type 2; Dipeptides; Dipeptidyl-Peptidase IV Inhibitors; Glucagon-Like Peptide 1; Humans; Hydroxymethylglutaryl-CoA Reductase Inhibitors; Hypoglycemic Agents; Incretins; Liraglutide; Metformin; Primary Health Care; Rosiglitazone; Thiazolidinediones; Vitamin B 12 Deficiency | 2011 |
Weight beneficial treatments for type 2 diabetes.
The close link between type 2 diabetes and excess body weight highlights the need to consider the weight effects of different treatment regimens. We examine the impact of "weight-friendly" type 2 diabetes pharmacotherapies and suggest treatment strategies that mitigate weight gain.. Evidence was identified via PubMed search by class and agent and in bibliographies of review articles, with final articles for inclusion selected by author consensus.. Substantial evidence confirms the weight benefits of metformin and shows that, of the newer available agents, glucagon-like peptide-1 (GLP-1) agonists and amylin analogs promote weight loss. Dipeptidyl peptidase-4 (DPP-4) inhibitors and bile acid sequestrants are weight-neutral. Liraglutide and exenatide appear to have similar effects on weight; however, recent research suggests a potentially greater effect of liraglutide on glycemic control compared to exenatide, when used as a second-line therapy. Mounting evidence suggests that insulin detemir may provide the most favorable weight benefits of available insulins.. Weight-beneficial agents should be considered in patients, particularly obese patients, who fail to reach glycemic targets on metformin therapy. We propose the following treatment choices based on potential weight benefit and blood glucose increment: long-acting GLP-1 agonists (liraglutide), DPP-4 inhibitors, bile acid sequestrants, amylin analogs, and basal insulin for patients with elevated fasting plasma glucose; and short-acting (exenatide) or long-acting GLP-1 agonists, amylin analogs, DPP-4 inhibitors, acarbose, and bile acid sequestrants for patients with elevated postprandial glucose. The weight-sparing effects of insulin detemir, notably in patients with high body mass index, should also be considered when initiating insulin therapy. Topics: Body Weight; Diabetes Mellitus, Type 2; Glucagon-Like Peptide 1; Humans; Hypoglycemic Agents; Insulin; Metformin; Obesity; Weight Loss | 2011 |
Glucagon-like peptide-1 analogues for Type 2 diabetes mellitus: current and emerging agents.
Novel therapeutic options for type 2 diabetes mellitus based on the action of the incretin hormone glucagon-like peptide (GLP)-1 were introduced in 2005. As injectable GLP-1 receptor agonists acting on the GLP-1 receptor, exenatide and liraglutide are available in many countries. In type 2 diabetes treatment, incretin-based therapies are attractive and more commonly used because of their mechanism of action and safety profile. Stimulation of insulin secretion and inhibition of glucagon secretion by these agents occur in a glucose-dependent manner. Therefore, incretin-based therapies have no intrinsic risk for hypoglycaemia. Furthermore, GLP-1 receptor agonists allow weight loss and lower systolic blood pressure. This review gives a brief overview of the mechanism of action and summarizes the clinical data available on exenatide and liraglutide as established substances. It further highlights the clinical study data of exenatide once weekly as the first long-acting GLP-1 receptor agonist and covers other new long acting GLP-1 receptor agonists currently in clinical development. The placement of GLP-1 receptor agonists in the treatment algorithm of type 2 diabetes is discussed. Topics: Diabetes Mellitus, Type 2; Exenatide; Glucagon-Like Peptide 1; Glucagon-Like Peptide-1 Receptor; Humans; Hypoglycemic Agents; Incretins; Liraglutide; Peptides; Receptors, Glucagon; Venoms | 2011 |
Next-generation GLP-1 therapy: an introduction to liraglutide.
Liraglutide, a once-daily human glucagon-like peptide-1 (GLP-1) analog, was approved by the US Food and Drug Administration in 2010 for the treatment of type 2 diabetes mellitus (T2DM). Glucagon-like peptide-1 enhances insulin secretion and inhibits glucagon in a glucose-dependent manner. The efficacy and safety of liraglutide were evaluated in 6 phase 3 trials in > 4000 patients in the Liraglutide Effect and Action in Diabetes (LEAD) program, in another trial in comparison with sitagliptin, and in another trial where basal insulin was added to liraglutide + metformin. At liraglutide doses of 1.2 mg or 1.8 mg once daily, significant mean reductions in glycated hemoglobin (HbA1c) (1%-1.6%) and fasting plasma glucose (15-43 mg/dL), as well as sustained weight loss (2-3 kg) and a low rate of hypoglycemia occurred. Mild and transient nausea, reported in 6% to 41% of patients, was the most frequent adverse event reported. Incretin-based therapies such as liraglutide provide an important expansion of options for the treatment of T2DM. Topics: Blood Glucose; Blood Pressure; Body Weight; Diabetes Mellitus, Type 2; Glucagon-Like Peptide 1; Humans; Hypoglycemic Agents; Insulin-Secreting Cells | 2011 |
Emerging GLP-1 receptor agonists.
Recently, glucagon-like peptide-1 receptor (GLP-1R) agonists have become available for the treatment of type 2 diabetes. These agents exploit the physiological effects of GLP-1, which is able to address several of the pathophysiological features of type 2 diabetes. GLP-1R agonists presently available are administered once or twice daily, but several once-weekly GLP-1R agonists are in late clinical development.. The present review aims to give an overview of the clinical data on the currently available GLP-1R agonists used for treatment of type 2 diabetes, exenatide and liraglutide, as well as the emerging GLP-1R agonists including the long-acting compounds.. An emerging therapeutic trend toward initial or early combination therapy with metformin- and incretin-based therapy is anticipated for patients with type 2 diabetes. GLP-1-based therapy has so far proven safe and tolerable. The determination of which incretin-based therapy to choose necessitates comparisons between the various GLP-1R agonists. The available GLP-1R agonists cause sustained weight loss and clinical relevant improvement of glycemic control. The long-acting GLP-1R agonists in late development may improve the effects of GLP-1 even further with optimized pharmacokinetic profiles resulting in fewer side effects. Meta-analyses have shown promising effects on cardiovascular disease and data from ongoing multicenter trials with cardiovascular endpoints are expected in 2015. Topics: Clinical Trials as Topic; Diabetes Mellitus, Type 2; Drug Design; Drugs, Investigational; Exenatide; Glucagon-Like Peptide 1; Glucagon-Like Peptide-1 Receptor; Humans; Hypoglycemic Agents; Liraglutide; Peptides; Receptors, Glucagon; Treatment Outcome; Venoms | 2011 |
Diabetes remission after bariatric surgery: is it just the incretins?
Gastric bypass surgery (GBP) results in important and sustained weight loss and remarkable improvement of Type 2 diabetes. The favorable change in the incretin gut hormones is thought to be responsible, in part, for diabetes remission after GBP, independent of weight loss. However, the relative role of the change in incretins and of weight loss is difficult to differentiate. After GBP, the plasma concentrations of the incretin hormones glucagon-like peptide 1 (GLP-1) and glucose-dependent insulinotropic polypeptide increase postprandially by three- to fivefold. The postprandial incretin effect on insulin secretion, blunted in diabetes, improves rapidly after the surgery. In addition to the change in incretins, the pattern of insulin secretion in response to oral glucose changes after GBP, with recovery of the early phase and significant decrease in postprandial glucose levels. These changes were not seen after an equivalent weight loss by diet. The improved insulin release and glucose tolerance after GBP were shown by others to be blocked by the administration of a GLP-1 antagonist, demonstrating that the favorable metabolic changes after GBP are, in part, GLP-1 dependent. The improved incretin levels and effect persist years after GBP, but their long-term effect on glucose metabolism, and on hypoglycemia post GBP are yet unknown. Understanding the mechanisms by which incretin release is exaggerated postprandially after GBP may help develop new less invasive treatment options for obesity and diabetes. Changes in rate of eating, gastric emptying, intestinal transit time, nutrient absorption and sensing, as well as bile acid metabolism, may all be implicated. Topics: Bariatric Surgery; Diabetes Mellitus, Type 2; Evidence-Based Medicine; Gastric Inhibitory Polypeptide; Glucagon-Like Peptide 1; Glucose; Humans; Incretins; Intestine, Small; Obesity, Morbid; Remission Induction; Weight Loss | 2011 |
Bariatric surgeries: beyond restriction and malabsorption.
Behavioral and pharmaceutical intervention to treat obesity and its comorbidities typically results in only a 5-10% weight loss. Thus, bariatric surgery is the most effective obesity treatment with some surgeries resulting in 30% sustained weight loss. Although this degree of weight loss has profound metabolic impact, these surgeries seem to have metabolic effects that are independent of weight loss. In support of this is the clinical literature showing rapid resolution of Type 2 diabetes mellitus (T2DM) that occurs before significant weight loss. To gain a complete understanding of the weight loss-independent effects of bariatric surgery, animal models have been developed. These are becoming more widely implemented and allow the use of pair-fed or weight-matched sham-operated controls in order to gain mechanistic insights into the mode of action of bariatric surgery. Increases in anorectic gut hormones, such as glucagon-like peptide-1 and peptide YY, or decreases in the orexigenic hormone ghrelin have been seen and are implicated as mediators of weight loss-independent actions of bariatric surgery. Changes in nutrient processing and sensing may also have a mechanistic role that is independent of, or that regulates, gut hormone responses to these surgeries. Ultimately, the hope is that understanding the mechanisms of bariatric surgeries will aid in the development of less invasive surgeries or pharmacological therapies that are more specifically, and perhaps individually, targeted at weight loss and/or resolution of T2DM. Topics: Animals; Blood Glucose; Diabetes Mellitus, Type 2; Gastric Bypass; Gastrointestinal Hormones; Glucagon-Like Peptide 1; Humans; Malabsorption Syndromes; Peptide YY; Weight Loss | 2011 |
The efficacy and safety of liraglutide.
To systematically analyze the efficacy and safety of liraglutide for the treatment of diabetes mellitus in comparison to other mono- and combination therapies.. PubMed (any date) and EMBASE (all years) search was conducted with liraglutide as a search term. Phase III clinical trials retrieved by the two databases and resources posted in Drug@FDA website were evaluated with regard to outcomes of efficacy and safety.. Eight Phase III clinical studies compared the efficacy and safety of liraglutide to other monotherapies or combinations. Liraglutide as monotherapy in doses of 0.9 mg or above showed a significantly superior reduction in HbA1C compared to monotherapies with glimepiride or glyburide. When liraglutide was used as add-on therapy to glimepiride in doses of 1.2 mg or above, the reduction of HbA1C was greater than that in the combination therapy of glimepiride and rosiglitazone. However, liraglutide as add-on therapy to metformin failed to show benefit over combination of metformin and glimepiride. Triple therapy of using liraglutide in addition to metformin plus either glimepiride or rosiglitazone resulted in additional benefit in HbA1C reduction. Most common adverse events were gastrointestinal disturbance such as nausea, vomit, diarrhea, and constipation. During the eight clinical studies, six cases of pancreatitis and five cases of cancer were reported in liraglutide arm, whereas there was one case of each of pancreatitis in exenatide and glimepiride arms, respectively, and one case of cancer in metformin plus sitagliptin arm.. Liraglutide is a new therapeutic option to improve glycemic control in patients with type 2 diabetes. However, the present lack of evidence of durability of efficacy and long-term safety appear to limit its utility in the general treatment of type 2 diabetes at this time. Topics: Clinical Trials, Phase III as Topic; Diabetes Mellitus, Type 2; Drug Therapy, Combination; Glucagon-Like Peptide 1; Humans; Hypoglycemic Agents; Liraglutide | 2011 |
[Pharmacogenetics of insulin secretagogue antidiabetics].
Type 2 diabetes is making up to 90% of the all diabetic cases. In addition to insulin resistance, insufficient B-cell function also plays an important role in the pathogenesis of the disease. The insufficient production and secretion of insulin can be increased by secretagogue drugs, like sulfonylureas and incretin mimetics/enhancers. In recent years growing number of genetic failures of the B-cells has been detected. These genetic variants can influence the efficacy of secretagogue drugs. Some of these gene polymorphisms were identified in the genes encoding the KATP channel (KCNJ11 and ABCC8). These mutations are able either to reduce or increase the insulin secretion and can modify the insulin response to sulfonylurea treatment. Other polymorphisms were found on genes encoding enzymes or transcription factors. In recent years, the genetic variants of TCF7L2 and its clinical importance have been intensely studied. Authors give a summary of the above gene polymorphisms and their role in insulin secretion. Topics: ATP-Binding Cassette Transporters; Diabetes Mellitus, Type 1; Diabetes Mellitus, Type 2; Genetic Predisposition to Disease; Glucagon-Like Peptide 1; Humans; Hypoglycemic Agents; Incretins; Insulin; Insulin Resistance; Insulin Secretion; KATP Channels; Mutation; Polymorphism, Genetic; Potassium Channels, Inwardly Rectifying; Receptors, Drug; Sulfonylurea Compounds; Sulfonylurea Receptors | 2011 |
Glucagon-like peptide analogues for type 2 diabetes mellitus.
Glucagon-like peptide analogues are a new class of drugs used in the treatment of type 2 diabetes that mimic the endogenous hormone glucagon-like peptide 1 (GLP-1). GLP-1 is an incretin, a gastrointestinal hormone that is released into the circulation in response to ingested nutrients. GLP-1 regulates glucose levels by stimulating glucose-dependent insulin secretion and biosynthesis, and by suppressing glucagon secretion, delayed gastric emptying and promoting satiety.. To assess the effects of glucagon-like peptide analogues in patients with type 2 diabetes mellitus.. Studies were obtained from electronic searches of The Cochrane Library (last search issue 1, 2011), MEDLINE (last search March 2011), EMBASE (last search March 2011), Web of Science (last search March 2011) and databases of ongoing trials.. Studies were included if they were randomised controlled trials of a minimum duration of eight weeks comparing a GLP-1 analogue with placebo, insulin, an oral anti-diabetic agent, or another GLP-1 analogue in people with type 2 diabetes.. Data extraction and quality assessment of studies were done by one reviewer and checked by a second. Data were analysed by type of GLP-1 agonist and comparison treatment. Where appropriate, data were summarised in a meta-analysis (mean differences and risk ratios summarised using a random-effects model).. Seventeen randomised controlled trials including relevant analyses for 6899 participants were included in the analysis. Studies were mostly of short duration, usually 26 weeks.In comparison with placebo, all GLP-1 agonists reduced glycosylated haemoglobin A1c (HbA1c) levels by about 1%. Exenatide 2 mg once weekly and liraglutide 1.8 mg reduced it by 0.20% and 0.24% respectively more than insulin glargine. Exenatide 2 mg once weekly reduced HbA1c more than exenatide 10 μg twice daily, sitagliptin and pioglitazone. Liraglutide 1.8 mg reduced HbA1c by 0.33% more than exenatide 10 μg twice daily. Liraglutide led to similar improvements in HbA1c compared to sulphonylureas but reduced it more than sitagliptin and rosiglitazone.Both exenatide and liraglutide led to greater weight loss than most active comparators, including in participants not experiencing nausea. Hypoglycaemia occurred more frequently in participants taking concomitant sulphonylurea. GLP-1 agonists caused gastrointestinal adverse effects, mainly nausea. These adverse events were strongest at the beginning and then subsided. Beta-cell function was improved with GLP-1 agonists but the effect did not persist after cessation of treatment.None of the studies was long enough to assess long-term positive or negative effects.. GLP-1 agonists are effective in improving glycaemic control. Topics: Diabetes Mellitus, Type 2; Glucagon-Like Peptide 1; Glycated Hemoglobin; Humans; Hypoglycemic Agents; Randomized Controlled Trials as Topic | 2011 |
Second-line therapy in patients with type 2 diabetes inadequately controlled with metformin monotherapy: a systematic review and mixed-treatment comparison meta-analysis.
Although there is general agreement that metformin should be used as first-line pharmacotherapy in patients with type 2 diabetes, uncertainty remains regarding the choice of second-line therapy once metformin is no longer effective. We conducted a systematic review and meta-analysis to assess the comparative safety and efficacy of all available classes of antihyperglycemic therapies in patients with type 2 diabetes inadequately controlled on metformin monotherapy.. MEDLINE, EMBASE, BIOSIS Previews, PubMed and the Cochrane Central Register of Controlled Trials were searched for randomized controlled trials published in English from 1980 to October 2009. Additional citations were obtained from grey literature and conference proceedings and through stakeholder feedback. Two reviewers independently selected studies, extracted data and assessed risk of bias. Key outcomes of interest were hemoglobin A1c, body weight, hypoglycemia, quality of life, long-term diabetes-related complications, serious adverse drug events and mortality. Mixed-treatment comparison and pairwise meta-analyses were conducted to pool trial results, when appropriate.. We identified 49 active and non-active controlled randomized trials that compared 2 or more of the following classes of antihyperglycemic agents and weight-loss agents: sulfonylureas, meglitinides, thiazolidinediones (TZDs), dipeptidyl peptidase-4 (DPP-4) inhibitors, glucagon-like peptide-1 (GLP-1) analogues, insulins, alpha-glucosidase inhibitors, sibutramine and orlistat. All classes of second-line antihyperglycemic therapies achieved clinically meaningful reductions in hemoglobin A1c (0.6% to 1.0%). No significant differences were found between classes. Insulins and insulin secretagogues were associated with significantly more events of overall hypoglycemia than the other agents, but severe hypoglycemia was rarely observed. An increase in body weight was observed with the majority of second-line therapies (1.8 to 3.0 kg), the exceptions being DPP-4 inhibitors, alpha-glucosidase inhibitors and GLP-1 analogues (0.6 to -1.8 kg). There were insufficient data available for diabetes complications, mortality or quality of life.. DPP-4 inhibitors and GLP-1 analogues achieved improvements in glycemic control similar to those of other second-line therapies, although they may have modest benefits in terms of weight gain and overall hypoglycemia. Further long-term trials of adequate power are required to determine whether newer drug classes differ from older agents in terms of clinically meaningful outcomes. Topics: Bayes Theorem; Body Weight; Confidence Intervals; Diabetes Mellitus, Type 2; Dipeptidyl-Peptidase IV Inhibitors; Disease Progression; Glucagon-Like Peptide 1; Glycated Hemoglobin; Humans; Hypoglycemia; Hypoglycemic Agents; Metformin; Risk Factors; Time Factors; Treatment Failure | 2011 |
Physiology of weight loss surgery.
The clinical outcomes achieved by bariatric surgery have been impressive. However, the physiologic mechanisms and complex metabolic effects of bariatric surgery are only now beginning to be understood. Ongoing research has contributed a large amount of data and shed new light on the science behind obesity and its treatment, and this article reviews the current understanding of metabolic and bariatric surgery physiology. Topics: Bariatric Surgery; Diabetes Mellitus, Type 2; Gastric Bypass; Gastric Inhibitory Polypeptide; Ghrelin; Glucagon-Like Peptide 1; Humans; Leptin; Neuropeptide Y; Obesity, Morbid; Peptide YY; Weight Loss | 2011 |
[Incretin-based therapy for treating patients with type 2 diabetes].
In the last couple of years, a new class of antidiabetic drugs became available for the clinical practice. Due to the intensive research, several new drugs reached the market. Among the incretinmimetics both the GLP-1 (glucagon like peptide-1)-receptor agonist exenatide and the GLP-1-analogue liraglutide can be used for treatment. As for incretin enhancers (dipeptidyl-peptidase-4 [DPP-4]-inhibitors), sitagliptin, vildagliptin and saxagliptin are available in Hungary, linagliptin will be introduced to the market in the near future. In clinical practice, any incretin-based new drugs can be used for treating patients with type 2 diabetes, preferably in combination with metformin. The clinical experiences with these new drugs are reviewed focusing on both the benefits and the potential side-effects of the particular compounds. Topics: Adamantane; Body Mass Index; Diabetes Mellitus, Type 2; Dipeptides; Dipeptidyl-Peptidase IV Inhibitors; Drug Approval; Drug Therapy, Combination; Exenatide; Gliclazide; Glucagon-Like Peptide 1; Glucagon-Like Peptide-1 Receptor; Glycated Hemoglobin; Humans; Hungary; Hypoglycemic Agents; Incretins; Linagliptin; Liraglutide; Metformin; Nitriles; Peptides; Pioglitazone; Purines; Pyrazines; Pyrrolidines; Quinazolines; Receptors, Glucagon; Sitagliptin Phosphate; Sulfonylurea Compounds; Thiazolidinediones; Triazoles; Venoms; Vildagliptin | 2011 |
Liraglutide: a review of its use in the management of type 2 diabetes mellitus.
Liraglutide (Victoza®) is a subcutaneously administered glucagon-like peptide-1 (GLP-1) receptor agonist produced by recombinant DNA technology and used as an adjunct to diet and exercise in the treatment of adults with type 2 diabetes mellitus. This article reviews the clinical efficacy and tolerability of liraglutide in adults with type 2 diabetes, and provides a summary of its pharmacological properties. Recently published pharmacoeconomic studies of liraglutide are also reviewed. Administered subcutaneously, liraglutide (usually 1.2 or 1.8 mg once daily) generally produced greater improvements in glycaemic control than active comparators or placebo when administered as monotherapy or in combination with one or two oral antidiabetic drugs (OADs) to adults with type 2 diabetes in numerous randomized, controlled phase III trials. These included six trials in the LEAD trial programme that was designed to evaluate the efficacy and safety of liraglutide across a continuum of antihyperglycaemic management for patients with type 2 diabetes. Liraglutide was generally well tolerated, with a low risk of hypoglycaemia evident, in the phase III trials. The most common adverse events were gastrointestinal and included nausea and diarrhoea; most events were mild to moderate in severity and decreased in incidence over time. In conclusion, liraglutide has an important place in the management of adults with type 2 diabetes across a continuum of care. As well as providing effective glycaemic control, liraglutide improves pancreatic β-cell function and leads to bodyweight loss, thereby addressing some of the unmet needs of patients treated with traditional OADs. Topics: Clinical Trials as Topic; Diabetes Mellitus, Type 2; Glucagon-Like Peptide 1; Humans; Hypoglycemic Agents; Liraglutide | 2011 |
[Free fatty acid receptors and their physiological role in metabolic regulation].
Free fatty acids (FFAs) are not only essential nutrient components, but they also function as signaling molecules in various physiological processes. In the progression of genomic analysis, many orphan G-protein coupled receptors (GPCRs) are found. Recently, GPCRs deorphanizing strategy successfully identified multiple receptors for FFAs. In these FFA receptors (FFARs), GPR40 (FFAR1) and GPR120 are activated by medium- to long- chain FFAs. GPR40 is expressed mainly in pancreatic β-cell and mediates insulin secretion, whereas GPR120 is expressed abundantly in the intestine and regulates the secretion of cholecystokinin (CCK) and glucagons-like peptide-1 (GLP-1), it promotes insulin secretion. Due to these biological activity, GPR40 and GPR120 are potential drug target for type 2 diabetes and selective ligands have been developed. In this review, we provide recent development in the field and discuss their physiological roles and their potential as drug targets. Topics: Animals; Cholecystokinin; Diabetes Mellitus, Type 2; Fatty Acids, Nonesterified; Glucagon-Like Peptide 1; Humans; Insulin; Insulin Secretion; Insulin-Secreting Cells; Intestinal Mucosa; Ligands; Mice; Molecular Targeted Therapy; Receptors, G-Protein-Coupled; Signal Transduction; Structure-Activity Relationship | 2011 |
[Effects of glucagon-like peptide-1 on appetite and body weight: preclinical and clinical data].
Obesity is associated with an increased risk of developing type 2 diabetes and cardiovascular disease. Pharmacological treatments of diabetes are mostly associated with weight gain, an undesirable event due to the fact that an increase in adiposity, especially visceral, is associated with reduced insulin sensitivity, worse cardiovascular risk profile and decreased adherence to treatment. Analogues of glucagon-like peptide-1 (GLP-1) represent a new therapeutic option for type 2 diabetes, which offer the advantage of combining beneficial effects on metabolic control with a significant reduction in body weight. In this review, we discuss data of preclinical studies and clinical trials that evaluated the effects of liraglutide and exenatide, the two analogues of GLP-1 currently available in Italy, on body weight. Topics: Appetite; Body Mass Index; Body Weight; Clinical Trials as Topic; Diabetes Mellitus, Type 2; Evidence-Based Medicine; Exenatide; Glucagon-Like Peptide 1; Humans; Hypoglycemic Agents; Insulin-Secreting Cells; Liraglutide; Models, Animal; Obesity; Peptides; Treatment Outcome; Venoms | 2011 |
[Protective effects of glucagon-like peptide-1 on beta-cells: preclinical and clinical data].
Dipartimento di Medicina Interna e Scienze dell'Invecchiamento, Università degli Studi "G. d'Annunzio", Chieti Continuing b-cell mass and function loss represents the key mechanism for the pathogenesis and the progression of type 2 diabetes mellitus. Drugs capable of arresting b-cell loss and eventually able to bring b-cell function close to be back to normal would then be a formidable help in type 2 diabetes mellitus treatment. The glucagon-like peptide-1 (GLP-1) receptor agonists exenatide and liraglutide can stimulate in vitro neogenesis and prevent apoptosis in b-cell-like cell lines. Consistently, treatment with GLP-1 receptor agonists ameliorates glucose metabolism, preserves b-cell mass and improves b-cell function in several animal models of diabetes. For instance, in the db/db mice, liraglutide protects the b-cell from oxidative stress and endoplasmic reticulum stress-related damage. Data in humans, in vivo, are less definitive and often based on scarcely reliable indexes of b-cell function. However, short-term treatment (14 weeks) with liraglutide increased b-cell maximal response capacity in a dose-response fashion. A longer (1 year) exenatide treatment also was able to increase b-cell maximal response capacity, but the effect was no longer there after a 4-week washout period. However, a marginal, although significant as compared to glargine treatment, improvement in another b-cell function index (disposition index) was observed after a 4-week washout period following 3-year exenatide treatment. Finally, although no clinical trials with a long enough follow-up period are presently available, durable glucose control has been obtained during 2 years of liraglutide treatment in monotherapy. Since the durability of good control is strictly dependent upon a lack of further b-cell function deterioration, these clinical data may foster hope that GLP-1 receptor antagonist treatment might help preserving b-cell function also in individuals affected by type 2 diabetes mellitus. Topics: Animals; Diabetes Mellitus, Type 2; Evidence-Based Medicine; Exenatide; Glucagon-Like Peptide 1; Humans; Hypoglycemic Agents; Insulin-Secreting Cells; Liraglutide; Peptides; Treatment Outcome; Venoms | 2011 |
[Cardioprotective effects of glucagon-like peptide-1: preclinical and clinical data].
The glucagon-like peptide-1 (GLP-1) is a 30 amino acid incretin hormone synthesized by L cells of ileum and colon in response to a meal. Once secreted, it is rapidly inactivated by specific enzymes called dipeptidyl dipeptidase 4. The main actions of GLP-1 are (i) to stimulate insulin secretion; (ii) to inhibit glucagon secretion; (iii) to elicit a delay of gastric emptying time; and (iv) to stimulate neogenesis of insulin-secreting cells. Patients with type 2 diabetes show low GLP-1 concentrations in response to a meal, making treatment with incretin mimetics specifically indicated in this patient subset. Besides these effects on intermediary metabolism, GLP-1 also plays an important role in the cardiovascular system by reducing blood pressure, improving endothelial function, and increasing myocardial contractility. These mechanisms of action will be discussed in detail in this article. Topics: Animals; Blood Pressure; Cardiovascular Diseases; Cardiovascular System; Clinical Trials as Topic; Controlled Clinical Trials as Topic; Diabetes Mellitus, Type 2; Endothelium, Vascular; Evidence-Based Medicine; Glucagon-Like Peptide 1; Glucagon-Like Peptide-1 Receptor; Humans; Hypoglycemic Agents; Insulin-Secreting Cells; Myocardial Contraction; Randomized Controlled Trials as Topic; Receptors, Glucagon; Treatment Outcome | 2011 |
[Pathophysiological background for incretin therapy: is it capable of more than we think?].
Incretin-based therapy functions through the increase of endogenous glucagon-like peptide-1 (GLP-1) levels due to inhibition of dipeptidyl peptidase-4--an enzyme degrading GLP-1 (gliptins) or through the administration of drugs activating GLP-1 receptor (GLP-1 agonists). Both approaches increase insulin and decrease glucagon secretion leading to improved diabetes compensation. The advantages of gliptins include little side effects, body weight neutrality and potential protective effects on pancreatic beta cells. GLP-1 agonists on the top of that consistently decrease body weight and blood pressure and their effects on diabetes compensation and likelihood of protective effects on beta cells is somewhat higher than those of gliptins. Another advantage of both approaches includes their safety with respect to induction of hypoglycemia. In addition to well-known metabolic effects, other potentially benefitial consequences of incretin based therapy in both type 2 diabetic and non-diabetic patients are anticipated. Direct positive effects of incretin-based therapy on myocardial metabolism and function as well as its positive influence on endothelial dysfunction and neuroprotective effects are intensively studied. The possible indications for GLP-1 agonists could be in future further widened to obese patients with type 1 diabetes and obese patients without diabetes. The aim of this review is to summarize both metabolic and extrapancreatic effects of incretin-based therapies and to outline perspectives of potential wider use of this treatment approach. Topics: Animals; Diabetes Mellitus, Type 2; Glucagon-Like Peptide 1; Humans; Hypoglycemic Agents; Incretins | 2011 |
Pleiotropic effects of glucagon-like peptide-1 (GLP-1)-based therapies on vascular complications in diabetes.
Accelerated atherosclerosis and microvascular complications are the leading causes of coronary heart disease, end-stage renal failure, acquired blindness and a variety of neuropathies, which could account for disabilities and high mortality rates in patients with diabetes. Glucagon-like peptide-1 (GLP-1) belongs to the incretin hormone family. L cells in the small intestine secrete GLP-1 in response to food intake. GLP-1 not only enhances glucose-evoked insulin release from pancreatic β-cells, but also suppresses glucagon secretion from pancreatic α-cells. In addition, GLP-1 slows gastric emptying. Therefore, enhancement of GLP-1 secretion is a potential therapeutic target for the treatment of type 2 diabetes. Dipeptidyl peptidase-4 (DPP-4) is a responsible enzyme that mainly degrades GLP-1, and the half-life of circulating GLP-1 is very short. Recently, DPP-4 inhibitors and DPP-4-resistant GLP-1 receptor (GLP-1R) agonists have been developed and clinically used for the treatment of type 2 diabetes as a GLP-1-based medicine. GLP-1R is shown to exist in extra-pancreatic tissues such as vessels, kidney and heart, and could mediate the diverse biological actions of GLP-1 in a variety of tissues. So, in this paper, we review the pleiotropic effects of GLP-1-based therapies and its clinical utility in vascular complications in diabetes. Topics: Animals; Diabetes Mellitus, Type 2; Diabetic Angiopathies; Diabetic Nephropathies; Diabetic Neuropathies; Diabetic Retinopathy; Dipeptidyl Peptidase 4; Dipeptidyl-Peptidase IV Inhibitors; Glucagon; Glucagon-Like Peptide 1; Glucagon-Like Peptide-1 Receptor; Humans; Insulin; Insulin Secretion; Insulin-Secreting Cells; Receptors, Glucagon | 2011 |
The role of incretin therapy at different stages of diabetes.
The pathogenetic mechanisms causing type 2 diabetes are complex, and include a significant reduction of the incretin effect. In patients with type 2 diabetes, GLP-1 secretion may be impaired, while GIP secretion seems unaffected. In contrast, the insulinotropic activity of GIP is severely altered, whereas that of GLP-1 is maintained to a great extent. Better understanding of the role of incretin hormones in glucose homeostasis has led to the development of incretin-based therapies that complement and offer important advantages over previously used agents. Incretin-based agents have significant glucose-lowering effects, promote weight loss (or are weight-neutral), inhibit glucagon secretion while maintaining counter-regulatory mechanisms, exhibit cardiovascular benefits, and protect β-cells while possessing a low risk profile. At present, incretin-based therapies are most widely used as add on to metformin to provide sufficient glycemic control after metformin failure. However, they are also recommended as monotherapy early in the disease course, and later in triple combination. These agents may also be a promising therapeutic tool in prediabetic subjects. Therefore, a therapeutic algorithm is needed for their optimal application at different stages of diabetes, as suggested in this article. Topics: Clinical Trials as Topic; Diabetes Mellitus, Type 2; Disease Progression; Glucagon-Like Peptide 1; Humans; Hypoglycemic Agents; Incretins; Prediabetic State | 2011 |
GLP-1, the gut-brain, and brain-periphery axes.
Glucagon-like peptide 1 (GLP-1) is a gut hormone which directly binds to the GLP-1 receptor located at the surface of the pancreatic β-cells to enhance glucose-induced insulin secretion. In addition to its pancreatic effects, GLP-1 can induce metabolic actions by interacting with its receptors expressed on nerve cells in the gut and the brain. GLP-1 can also be considered as a neuropeptide synthesized by neuronal cells in the brain stem that release the peptide directly into the hypothalamus. In this environment, GLP-1 is assumed to control numerous metabolic and cardiovascular functions such as insulin secretion, glucose production and utilization, and arterial blood flow. However, the exact roles of these two locations in the regulation of glucose homeostasis are not well understood. In this review, we highlight the latest experimental data supporting the role of the gut-brain and brain-periphery axes in the control of glucose homeostasis. We also focus our attention on the relevance of β-cell and brain cell targeting by gut GLP-1 for the regulation of glucose homeostasis. In addition to its action on β-cells, we find that understanding the physiological role of GLP-1 will help to develop GLP-1-based therapies to control glycemia in type 2 diabetes by triggering the gut-brain axis or the brain directly. This pleiotropic action of GLP-1 is an important concept that may help to explain the observation that, during their treatment, type 2 diabetic patients can be identified as 'responders' and 'non-responders'. Topics: Animals; Brain; Diabetes Mellitus, Type 2; Glucagon-Like Peptide 1; Humans; Intestinal Mucosa; Peripheral Nervous System | 2011 |
Update on incretin hormones.
The incretin hormones glucagon-like-peptide-1 (GLP-1) and glucose-dependent insulinotropic polypeptide (GIP) are released from the intestine following oral ingestion of nutrients. Incretins promote insulin secretion, while GLP-1 also inhibits glucagon release and gastric emptying, minimizing postprandial glucose excursions. The incretins share similar effects on the pancreatic β cell; however, there are a number of differences in extrapancreatic actions. Type 2 diabetes (T2DM) is associated with abnormal incretin physiology, and although treatment with GIP is ineffective, GLP-1 effects are preserved. The current incretin-based approaches to T2DM include the GLP-1 agonists that are resistant to the serine protease dipeptidylpeptidase-4 (DPP4), which normally rapidly degrades the incretins, and DPP4 inhibitors (DPP4i). Incretin-based treatments have provoked much interest due to use-associated weight loss (GLP-1 agonists), minimal hypoglycemia, and potential for positive effects on pancreatic β cell biology and the cardiovascular system. However, the long-term safety of these agents has yet to be established. This review outlines the current understanding of incretin biology, available data pertaining to incretin-based treatment in T2DM, and differences between GLP-1 and DPP4i therapy. Topics: Animals; Diabetes Mellitus, Type 2; Dipeptidyl-Peptidase IV Inhibitors; Glucagon-Like Peptide 1; Glucose; Humans; Incretins; Insulin; Receptors, Gastrointestinal Hormone | 2011 |
Glycaemic control in type 2 diabetes: targets and new therapies.
Type 2 diabetes mellitus (T2DM) is a worldwide public health challenge. Despite the availability of many antidiabetes agents and pharmacotherapies targeting cardiovascular risk factors, the morbidity, mortality and economic consequences of T2DM are still a great burden to patients, society, health care systems and the economy. The need for new therapies for glycaemic control is compounded by the fact that existing treatments have limitations either because of their side effects (particularly weight gain and hypoglycaemia) or contraindications that limit their use. Furthermore, none of the current therapies have a significant impact on disease progression. Incretin-based therapies offer a new therapeutic approach to the management of T2DM, and there are also several even newer therapies in development. There are two groups of incretin-based therapies currently available; dipeptidyl peptidase-4 (DPP-4) inhibitors and GLP-1 analogues/mimetics. The former are given orally while the latter subcutaneously. These drugs result in glucose-dependent insulin secretion and glucose-dependent glucagon suppression, with consequent low risk of hypoglycaemia when used as mono- or combination therapy (except when used with sulphonylureas). In addition, they are either weight neutral in the case of DPP-4 inhibitors or cause weight loss in the case of incretin mimetics/analogues. Furthermore, animal studies have shown that these agents prolong beta cell survival which offers the theoretical possibility of slowing the progression to T2DM. In this article we will review the currently available antidiabetes agents with particular emphasis on incretin-based and future therapies. In addition, we will review and discuss the evidence relating to glycaemic control and cardiovascular disease. Topics: Animals; Cardiovascular Diseases; Diabetes Mellitus, Type 2; Dipeptidyl-Peptidase IV Inhibitors; Drug Administration Routes; Drug Interactions; Glucagon-Like Peptide 1; Humans; Hypoglycemic Agents; Incretins | 2010 |
Benefit-risk assessment of exenatide in the therapy of type 2 diabetes mellitus.
Exenatide is the first incretin mimetic, introduced into type 2 diabetes mellitus therapy in 2005, with first approval in the US. It is a glucagon-like peptide-1 (GLP-1) receptor agonist that can be used for treatment by twice-daily injection. A long-acting release formulation for once-weekly injection is in clinical development. Clinical studies and postmarketing experience with exenatide have shown a significant and sustained reduction in glycosylated haemoglobin (HbA(1c)) by approximately 1% together with other gylcaemic parameters without an intrinsic risk for hypoglycaemias, and a reduction in bodyweight by 5.3 kg in 82 weeks. Blood pressure and lipids are also favourably affected, but hard cardiovascular endpoints are not yet available. Animal studies show an improvement of beta-cell function and an increase in beta-cell mass after exenatide treatment. The most frequent adverse events associated with exenatide therapy are nausea and antibody formation (both approximately 40%). Nausea, mostly mild and transient, was responsible for a 6% dropout rate in clinical studies. A recent review on the association of acute pancreatitis with exenatide treatment showed no increased risk (relative risk 1.0; 95% CI 0.6, 1.7). This review gives a benefit-risk assessment of exenatide. Topics: Animals; Diabetes Mellitus, Type 2; Exenatide; Glucagon-Like Peptide 1; Glycated Hemoglobin; Humans; Hypoglycemic Agents; Injections, Subcutaneous; Peptides; Risk Assessment; Venoms | 2010 |
The role of basal insulin and glucagon-like peptide-1 agonists in the therapeutic management of type 2 diabetes--a comprehensive review.
The treatment of type 2 diabetes mellitus (T2DM) has been revolutionized by the introduction of novel therapeutic regimens following the clinical approval of the long-acting basal insulin glargine 10 years ago, followed by insulin detemir and, more recently, agents that target the glucagon-like peptide (GLP)-1 system with dipeptidyl peptidase 4 (DPP-4)-resistant products, such as liraglutide and exenatide, and DPP-4 inhibitors, such as sitagliptin, saxagliptin, alogliptin, and vildagliptin. The position and clinical efficacy of the GLP-1 mimetics are less well understood, however, and how they should be best used in the context of the established clinical efficacy of long-acting insulin analogs is yet to be defined. The aim of this review is to provide a summary of the efficacy, safety, and weight changes associated with long-acting insulin analogs (insulin glargine and insulin detemir) and two GLP-1 mimetics (exenatide and liraglutide). MEDLINE, EMBASE, and BIOSIS databases were searched with a timeframe of January 1, 2003-January 12, 2009 using the following terms: "Insulin glargine," with the co-indexing terms "LANTUS" and "HOE901"; "Insulin detemir," with the co-indexing term "Levemir"; "Exenatide"; and "Liraglutide." This literature review demonstrates that GLP-1 and basal insulin therapies are effective treatment options for insulin-naïve patients with suboptimal glycemic control with oral hypoglycemic agents. There are potential advantages of basal insulin and GLP-1 therapies in particular populations of patients. Further comparative data are needed to fully investigate the relative positioning of these therapies within the T2DM treatment paradigm. Topics: Diabetes Mellitus, Type 2; Glucagon-Like Peptide 1; Humans; Hyperglycemia; Hypoglycemic Agents; Insulin; Insulin Detemir; Insulin Glargine; Insulin, Isophane; Insulin, Long-Acting | 2010 |
Therapeutic options that provide glycemic control and weight loss for patients with type 2 diabetes.
Type 2 diabetes mellitus and comorbidities related to overweight/obesity are risk factors for the development of cardiovascular disease (CVD). In addition to insulin resistance and progressive beta-cell failure as key factors in the pathogenesis of type 2 diabetes mellitus, defects in the incretin system are now known to contribute as well. Lifestyle modifications including diet and exercise are often insufficient for reducing glucose and weight, and most patients with type 2 diabetes will require pharmacotherapy to treat their hyperglycemia. Goals of therapy should be to reduce blood glucose to as low as possible, for as long as possible, without weight gain and hypoglycemia, and correcting cardiovascular risk factors. Numerous antidiabetes medications lower blood glucose; however, many are associated with weight gain and do not address risk factors present for CVD. Newer pharmacotherapies include the glucagon-like peptide-1 (GLP-1) receptor agonists, dipeptidyl peptidase-4 (DPP-4) inhibitors, and amylinomimetics. The GLP-1 receptor agonists and amylinomimetics reduce glucose while promoting weight loss and improving other cardiovascular risk factors with a low incidence of hypoglycemia. The DPP-4 inhibitors effectively lower glucose and are weight neutral. Topics: Diabetes Mellitus, Type 2; Dipeptidyl-Peptidase IV Inhibitors; Exenatide; Glucagon-Like Peptide 1; Glucagon-Like Peptide-1 Receptor; Glycated Hemoglobin; Humans; Hyperglycemia; Hypoglycemic Agents; Incretins; Life Style; Liraglutide; Obesity; Overweight; Peptides; Receptors, Glucagon; Venoms; Weight Loss | 2010 |
Roles of gastrointestinal and adipose tissue peptides in childhood obesity and changes after weight loss due to lifestyle intervention.
Childhood obesity is a global epidemic and associated with an increased risk of hypertension, diabetes mellitus, and coronary heart disease, in addition to psychological disorders. Interventions such as bariatric surgery are highly invasive and lifestyle modifications are often unsuccessful because of disturbed perceptions of satiety. New signaling peptides discovered in recent years that are produced in peripheral tissues such as the gut, adipose tissue, and pancreas communicate with brain centers of energy homeostasis, such as the hypothalamus and hindbrain. This review discusses the major known gut- and adipose tissue-derived hormones involved in the regulation of food intake and energy homeostasis and their serum levels in childhood obesity before and after weight loss as well as their relationship to consequences of obesity. Since most of the changes of gastrointestinal hormones and adipokines normalize in weight loss, pharmacological interventions based on these hormones will likely not solve the obesity epidemic in childhood. However, a better understanding of the pathways of body weight- and food intake-regulating gut- and adipose tissue-derived hormones will help to find new strategies to treat obesity and its consequences. Topics: Adipokines; Adipose Tissue; Child; Cholecystokinin; Diabetes Mellitus, Type 2; Dipeptides; Enteropeptidase; Exercise; Glucagon-Like Peptide 1; Health Behavior; Health Promotion; Humans; Hypothalamus; Life Style; Obesity; Oxyntomodulin; Pancreatic Polypeptide; Rhombencephalon; Weight Loss | 2010 |
Glucagon-like peptide 1 receptor stimulation as a means of neuroprotection.
Glucagon-like peptide 1 (GLP-1) is a relatively recently discovered molecule originating in the so-called L-cells of the intestine. The peptide has insulinotrophic properties and it is this characteristic that has predominantly been investigated. This has led to the use of the GLP-1-like peptide exendin-4 (EX-4), which has a much longer plasma half-life than GLP-1 itself, being used in the treatment of type II diabetes. The mode of action of this effect appears to be a reduction in pancreatic apoptosis, an increase in beta cell proliferation or both. Thus, the effects of GLP-1 receptor stimulation are not based upon insulin replacement but an apparent repair of the pancreas. Similar data suggest that the same effects may occur in other peripheral tissues. More recently, the roles of GLP-1 and EX-4 have been studied in nervous tissue. As in the periphery, both peptides appear to promote cellular growth and reduce apoptosis. In models of Alzheimer's disease, Parkinson's disease and peripheral neuropathy, stimulation of the GLP-1 receptor has proved to be highly beneficial. In the case of Parkinson's disease this effect is evident after the neurotoxic lesion is established, suggesting real potential for therapeutic use. In the present review we examine the current status of the GLP-1 receptor and its potential as a therapeutic target. Topics: Alzheimer Disease; Animals; Apoptosis; Diabetes Mellitus, Type 2; Exenatide; Glucagon-Like Peptide 1; Glucagon-Like Peptide-1 Receptor; Half-Life; Insulin; Insulin-Secreting Cells; Intestines; Neuroprotective Agents; Pancreas; Peptides; Receptors, Glucagon; Venoms | 2010 |
The evolving place of incretin-based therapies in type 2 diabetes.
Treatment options for type 2 diabetes based on the action of the incretin hormone glucagon-like peptide-1 (GLP-1) were first introduced in 2005. These comprise the injectable GLP-1 receptor agonists solely acting on the GLP-1 receptor on the one hand and orally active dipeptidyl-peptidase inhibitors (DPP-4 inhibitors) raising endogenous GLP-1 and other hormone levels by inhibiting the degrading enzyme DPP-4. In adult medicine, both treatment options are attractive and more commonly used because of their action and safety profile. The incretin-based therapies stimulate insulin secretion and inhibit glucagon secretion in a glucose-dependent manner and carry no intrinsic risk of hypoglycaemia. GLP-1 receptor agonists allow weight loss, whereas DPP-4 inhibitors are weight neutral. This review gives an overview of the mechanism of action and the substances and clinical data available. Topics: Adolescent; Adult; Animals; Child; Diabetes Mellitus, Type 2; Dipeptidyl Peptidase 4; Dipeptidyl-Peptidase IV Inhibitors; Disease Models, Animal; Glucagon; Glucagon-Like Peptide 1; Humans; Hypoglycemic Agents; Insulin; Insulin Secretion | 2010 |
Mechanisms facilitating weight loss and resolution of type 2 diabetes following bariatric surgery.
Bariatric surgery is the most effective treatment modality for obesity, resulting in durable weight loss and amelioration of obesity-associated comorbidities, particularly type 2 diabetes mellitus (T2DM). Moreover, the metabolic benefits of bariatric surgery occur independently of weight loss. There is increasing evidence that surgically induced alterations in circulating gut hormones mediate these beneficial effects of bariatric surgery. Here, we summarise current knowledge on the effects of different bariatric procedures on circulating gut hormone levels. We also discuss the theories that have been put forward to explain the weight loss and T2DM resolution following bariatric surgery. Understanding the mechanisms mediating these beneficial outcomes of bariatric surgery could result in new non-surgical treatment strategies for obesity and T2DM. Topics: Bariatric Surgery; Caloric Restriction; Diabetes Mellitus, Type 2; Energy Metabolism; Ghrelin; Glucagon-Like Peptide 1; Humans; Obesity; Peptide YY; Weight Loss | 2010 |
Exenatide and weight loss.
Glucagon-like peptide-1 (GLP-1) is a gastrointestinal hormone mainly released from the distal ileum, jejunum, and colon in response to food ingestion. It is categorized as an incretin due to its activation of GLP-1 receptors in pancreatic beta-cells leading to insulin exocytosis in a glucose-dependent manner. Exenatide (synthetic exendin-4) is a subcutaneously injected GLP-1 receptor agonist that shares 50% homology with GLP-1. It is derived from lizard venom and stimulates the GLP-1 receptor for prolonged periods. The present review aims to enumerate exenatide-instigated weight loss, summarize the known mechanisms of exenatide-induced weight loss, and elaborate on its possible application in the pharmacotherapy of obesity.. A search through PubMed was performed using exenatide and weight loss as search terms. A second search was performed using exenatide and mechanisms or actions as search terms.. In addition to exenatide's action to increase insulin secretion in individuals with elevated levels of plasma glucose, clinical trials have reported consistent weight loss associated with exenatide treatment. Studies have found evidence that exenatide decreases energy intake and increases energy expenditure, but findings on which predominates to cause weight loss are often inconsistent and controversial.. Further research on the effects of exenatide treatment on energy intake and expenditure are recommended to better understand the mechanisms through which exenatide causes weight loss. Topics: Animals; Diabetes Mellitus, Type 2; Energy Intake; Energy Metabolism; Exenatide; Glucagon-Like Peptide 1; Humans; Hypoglycemic Agents; Insulin; Insulin Secretion; Lizards; Obesity; Peptides; Receptors, Glucagon; Venoms; Weight Loss | 2010 |
[DPP-IV inhibitors and GLP-1 analogues].
Topics: Diabetes Mellitus, Type 2; Dipeptidyl-Peptidase IV Inhibitors; Glucagon-Like Peptide 1; Humans; Hypoglycemic Agents; Incretins | 2010 |
[DPP-4 inhibitors in clinical use. Therapy without the risk of hypoglycaemia].
Topics: Adamantane; Diabetes Mellitus, Type 2; Dipeptides; Dipeptidyl-Peptidase IV Inhibitors; Glucagon-Like Peptide 1; Humans; Hypoglycemia; Hypoglycemic Agents; Incretins; Nitriles; Pyrazines; Pyrrolidines; Sitagliptin Phosphate; Triazoles; Vildagliptin | 2010 |
[Gliptin and GLP-1 analogues - aspects of pharmaceutical care. The patient's responsibility].
Topics: Diabetes Mellitus; Diabetes Mellitus, Type 2; Dipeptidyl-Peptidase IV Inhibitors; Glucagon-Like Peptide 1; Humans; Patients; Pharmaceutical Services | 2010 |
[The unresolved problems of type 2 diabetes. Diabetology practice].
Topics: Diabetes Mellitus, Type 2; Dipeptidyl-Peptidase IV Inhibitors; Glucagon-Like Peptide 1; Humans; Hypoglycemic Agents; Incretins | 2010 |
Effects of incretin hormones on beta-cell mass and function, body weight, and hepatic and myocardial function.
Type 2 diabetes mellitus is a chronic debilitating disease characterized by insulin resistance and progressive pancreatic dysfunction. Concomitant with declining pancreatic function and decreasing insulin production, there is a progressive increase in blood glucose levels. Hyperglycemia plays a major role in the development of the microvascular and macrovascular complications of diabetes. Traditional agents used for the treatment of type 2 diabetes are able to improve glycemia, but their use is often limited by treatment-associated side effects, including hypoglycemia, weight gain, and edema. Moreover, these agents do not have any sustained effect on beta-cell mass or function. The introduction of incretin hormone-based therapies represents a novel therapeutic strategy, because these drugs not only improve glycemia with minimal risk of hypoglycemia but also have other extraglycemic beneficial effects. In clinical studies, both exenatide (the first dipeptidyl peptidase-4-resistant glucagonlike peptide-1 receptor agonist approved by the US Food and Drug Administration [FDA]), and liraglutide (a long-acting incretin mimetic), improve beta-cell function and glycemia with minimal hypoglycemia. Both agents have trophic effects on beta-cell mass in animal studies. The use of these agents is also associated with reduced body weight and improvements in blood pressure, diabetic dyslipidemia, hepatic function, and myocardial function. These effects have the potential to reduce the burden of cardiovascular disease, which is a major cause of mortality in patients with diabetes. Topics: Animals; Blood Pressure; Body Weight; Diabetes Mellitus, Type 2; Endothelium, Vascular; Exenatide; Gastric Inhibitory Polypeptide; Glucagon-Like Peptide 1; Glucagon-Like Peptide-1 Receptor; Heart; Humans; Hypoglycemic Agents; Incretins; Insulin-Secreting Cells; Liraglutide; Liver; Peptides; Receptors, Glucagon; Venoms | 2010 |
The novel roles of glucagon-like peptide-1, angiotensin II, and vitamin D in islet function.
Pancreatic islets secrete multiple factors that act as endocrine, paracrine, and/or autocrine pathways in regulating pancreatic endocrine function. As such, the islets perform critical biological activities in synthesizing metabolic peptide hormones, notably insulin and regulating body glucose homeostasis. These functions are controlled by various conditions and signaling molecules, particularly nutrients like glucose levels. However, more and more clinically relevant regulators, including molecules which stimulate islet beta-cell metabolism, regulate beta-cell [Ca(2+)] homeostasis and related channels or adjust beta-cell membrane, and nuclear receptors activity continue to be discovered and characterized. Of great interest in this context, glucagon-like peptide-1 can improve glycemic control by regulating insulin secretion and islet cell mass; vitamin D can regulate islet physiology directly by binding its receptors; in addition, the peptide hormone angiotensin II has been implicated in islet function and exhibits effects on islet cell secretion as well as cell mass. In this chapter, these three novel regulators in islet function and thus its clinical relevance to type 2 diabetes mellitus will undergo critical appraisal. Since all of these molecules have biological interactions with pancreatic islets, potential relationships may exist among them and they will also be discussed. Topics: Angiotensin II; Angiotensins; Animals; Blood Pressure; Cell Nucleus; Diabetes Mellitus, Experimental; Diabetes Mellitus, Type 2; Glucagon-Like Peptide 1; Humans; Islets of Langerhans; Mice; Models, Biological; Peptides; Vitamin D | 2010 |
Diabetes therapy: novel patents targeting the glucose-induced insulin secretion.
Type 2 diabetes mellitus has become a world wide extended disease, and while insulin insensitivity is an early phenomenon partly related to obesity, pancreas beta-cell function declines gradually over time already before the onset of clinical hyperglycaemia. Therefore, drugs able to stimulate or enhance insulin secretion will moderate hyperglycemia and then reduce the occurrence of later complication of the disease. Current strategies in type 2 diabetes include sulphonylurea compounds, GLP1, exendin 4 and DPP4 inhibitors and GK activators. Since many diabetic patients still exhibit poor glycemic control, other fail to respond to the treatment, and some develop serious complications, more effective treatments for diabetes than those mentioned above remain challenging for modern research. Then, the present review will focus on existing approaches and novel patents targeting beta-cell, with special emphasis in those related with the glucose-induced insulin secretion process. The management of this disease includes not only diet and exercise, but also utilization of antihyperglycemic new drugs, gene therapy strategies and combinations of novel insulin releasers and secretagogues. Topics: Diabetes Mellitus, Type 2; Drug Delivery Systems; Genetic Therapy; Glucagon-Like Peptide 1; Glucokinase; Glucose; Insulin; Insulin Secretion; Patents as Topic; Secretory Rate | 2010 |
[New blood glucose-lowering drugs in type 2 diabetes: a review of the literature].
To describe the efficacy and safety of the glucagon-like peptide 1 (GLP-1) analogues exenatide and liraglutide, and the dipeptidyl peptidase-4 (DPP-4) inhibitors vildagliptin and sitagliptin, registered in the Netherlands for treatment of type 2 diabetes mellitus (DM2).. Literature study.. The Medline database was searched up to and including August 2009 for systematic reviews and randomised trials with a minimum duration of 12 weeks in patients with DM2. Two authors independently selected the studies based on the title, abstract and, if necessary, the full text.. In addition to 1 systematic review on GLP-1 analogues and 1 review on DPP-4 inhibitors, 10 studies on DPP-4 inhibitors and 16 studies on GLP-1 analogues were included. According to these studies, the DPP-4 inhibitors sitagliptin and vildagliptin gave a mean HbA1c reduction of 0.7% and 0.6% respectively. GLP-1 analogues led to a mean HbA1c reduction of 1%, which is comparable to insulin therapy. Sitagliptin was associated with a slight increase in the number of upper respiratory tract infections. In a large number of patients, GLP-1 analogues were associated with gastrointestinal complaints. DPP-4 inhibitors were associated with a small weight gain, compared with weight loss in patients treated with GLP-1 analogues. Data on microvascular and macrovascular complications, as well as data on mortality, are not yet available in either group.. GLP-1 analogues regulate blood glucose levels as effectively as the current glucose-lowering agents; DPP-4 inhibitors are less effective. GLP-1 analogues lead to a clear weight reduction while DPP-4 inhibitors cause slight weight gain. Data on efficacy and safety in the longer term are not yet available. Topics: Adamantane; Blood Glucose; Body Weight; Diabetes Mellitus, Type 2; Dipeptidyl-Peptidase IV Inhibitors; Exenatide; Glucagon-Like Peptide 1; Glycated Hemoglobin; Humans; Hypoglycemic Agents; Liraglutide; Nitriles; Peptides; Pyrazines; Pyrrolidines; Sitagliptin Phosphate; Treatment Outcome; Triazoles; Venoms; Vildagliptin | 2010 |
Minireview: update on incretin biology: focus on glucagon-like peptide-1.
The incretin hormone, glucagon-like peptide-1 (GLP-1), is now being used in the clinic to enhance insulin secretion and reduce body weight in patients with type 2 diabetes. Although much is already known about the biology of GLP-1, much remains to be understood. Hence, this review will consider recent findings related to the potential for enhancing endogenous levels of GLP-1 through selective use of secretagogues and the beneficial cardiovascular, neuroprotective, and immunomodulatory effects of GLP-1, as well as the possible effects of GLP-1 to enhance beta-cell growth and/or to induce pancreatitis or thyroid cancer. Finally, the potential for molecular medicine to enhance the success of GLP-1 therapy in the clinic is considered. A better understanding of the fundamental biology of GLP-1 may lead to new therapeutic modalities for the clinical use of this intestinal hormone. Topics: Animals; Apoptosis; Diabetes Mellitus, Type 2; Glucagon-Like Peptide 1; Humans; Hypoglycemic Agents; Incretins; Insulin-Secreting Cells; Receptors, Glucagon | 2010 |
Dutogliptin, a dipeptidyl peptidase-4 inhibitor for the treatment of type 2 diabetes mellitus.
Dutogliptin (PHX-1149T), being developed by Phenomix Corp, Forest Laboratories Inc and Chiesi Farmaceutici SpA, is a small-molecule dipeptidyl peptidase-4 (DPP-4) inhibitor for the potential oral treatment of type 2 diabetes mellitus (T2DM). DPP-4 quickly degrades the insulin secretory hormones, glucose-dependent insulinotropic peptide and glucagon-like peptide-1; thus inhibiting the degradation of these hormones is a viable treatment option for patients with T2DM. In preclinical studies, dutogliptin potently inhibited DPP-4 and, in a model of T2DM, treatment with dutogliptin improved glucose homeostasis. Pharmacokinetic analyses in animals, healthy individuals and patients with T2DM demonstrated that drug exposure increased in a dose-dependent manner. Results from phase II clinical trials indicated that once-daily dutogliptin, in combination with other oral diabetes therapies, reduces postprandial blood glucose and HbA1c levels, both indicators of successful diabetes management. In phase I and II trials, dutogliptin was safe, well tolerated and associated with extremely low rates of hypoglycemia. At the time of publication, phase III trials were underway and the results of these will be imperative to determine the efficacy of dutogliptin compared with other small molecule DPP-4 inhibitors, such as sitagliptin and vildagliptin. Topics: Animals; Blood Glucose; Clinical Trials as Topic; Diabetes Mellitus, Type 2; Gastric Inhibitory Polypeptide; Glucagon-Like Peptide 1; Glucose; Humans; Protease Inhibitors | 2010 |
Incretin analogues that have been developed to treat type 2 diabetes hold promise as a novel treatment strategy for Alzheimer's disease.
Analogues of the incretins Glucagon-like peptide 1 (GLP-1) and Glucose-dependent insulinotropic peptide (GIP) have been developed to treat type 2 diabetes mellitus. They are protease resistant and have a longer biological half life than the native peptides. Some of these novel analogues can cross the blood-brain barrier, have neuroprotective effects, activate neuronal stem cells in the brain, and can improve cognition. The receptors for GIP and GLP-1 are expressed in neurons, and both GIP and GLP-1 are expressed and released as transmitters by neurons. GIP analogues such as DAla(2)GIP and GLP-1 analogues such as liraglutide enhance synaptic plasticity in the brain and also reverse the betaamyloid induced impairment of synaptic plasticity. In mouse models of Alzheimer's disease, GLP-1 analogues Val(8)GLP-1 and liraglutide prevent memory impairment and the block of synaptic plasticity in the brain. Since two GLP- 1 analogues exendin-4 (Exenatide, Byetta) and liraglutide (Victoza) are already on the market as treatments for Type 2 diabetes, and others are in late stage clinical trials, these drugs show promise as treatments for neurodegenerative diseases such as Alzheimer's disease. Currently, there are three patents covering native GLP-1 and different GLP-1 analogues and one patent for the use of GIP and different GIP analogues for the treatment of neurodegenerative diseases. Topics: Alzheimer Disease; Amino Acid Sequence; Animals; Blood-Brain Barrier; Diabetes Mellitus, Type 2; Gastric Inhibitory Polypeptide; Glucagon-Like Peptide 1; Humans; Incretins; Models, Neurological; Molecular Sequence Data; Neuroprotective Agents; Patents as Topic | 2010 |
[GLP-1: a new therapeutic principle for the treatment of type 2 diabetes mellitus].
Topics: Blood Glucose; Body Mass Index; Diabetes Mellitus, Type 2; Dipeptidyl Peptidase 4; Dipeptidyl-Peptidase IV Inhibitors; Drug Approval; Drug Therapy, Combination; Glucagon-Like Peptide 1; Glycated Hemoglobin; Humans; Hypoglycemic Agents; Incretins; Insulin; Male; Metformin; Middle Aged; Pyrazines; Risk Factors; Satiety Response; Sitagliptin Phosphate; Triazoles; Weight Loss | 2010 |
Albiglutide: a new GLP-1 analog for the treatment of type 2 diabetes.
Despite the wide array of treatments available, a significant number of patients with type 2 diabetes continue to remain uncontrolled. The discovery of the incretin hormones and their role in glucose homeostasis has brought about a new class of medications called the glucagon-like peptide-1 (GLP-1) analogs. This new class of medications provides the benefits of weight loss as well as a lack of hypoglycemia. However, the currently available agents require once or twice daily injections.. Relevant literature will be discussed on albiglutide, a new GLP-1 analog in Phase III clinical trials. Several clinical trials examining the use of albiglutide as combination therapy are currently ongoing.. To date, results of clinical trials suggest that albiglutide may provide a more attractive dosing profile compared with the currently available GLP-1 analogs.. The results of ongoing trials will help define the role of albiglutide in treating patients with type 2 diabetes. Topics: Diabetes Mellitus, Type 2; Drug Therapy, Combination; Evidence-Based Medicine; Glucagon-Like Peptide 1; Humans; Hypoglycemic Agents; Incretins; Injections, Subcutaneous; Treatment Outcome | 2010 |
Association of pancreatitis with glucagon-like peptide-1 agonist use.
To review the possible association between glucagon-like peptide-1 (GLP-1) agonist use and pancreatitis in patients with type 2 diabetes mellitus.. A MEDLINE search (1950-January 2010) identified key clinical trials delineating adverse effects associated with GLP-1 agonist use. Key search terms included type 2 diabetes mellitus, pancreatitis, incretins, exenatide, liraglutide, albiglutide, and taspoglutide. Review of references listed in the articles identified was also performed. The Food and Drug Administration (FDA) Web site and Amylin Pharmaceuticals file data were utilized to extract case report information and unpublished clinical development data related to GLP-1 agonist use and pancreatitis.. Phase 2 and 3 clinical trials evaluating exenatide, liraglutide, albiglutide, and taspoglutide that discussed treatmentrelated adverse effects as well as FDA-reviewed case reports of pancreatitis in patients taking these same therapies were included. One study evaluating type 2 diabetes as a risk factor for development of acute pancreatitis was also included. Exenatide case reports and clinical development data were also included.. Currently there have been 8 cases during clinical development and 36 postmarketing reports of acute pancreatitis in exenatide-treated patients. Four patients have developed acute (n = 3) or chronic (1) pancreatitis during liraglutide clinical trials. There have been no reports to date of development of acute pancreatitis in patients taking albiglutide or taspoglutide.. Observational reports and clinical trial data suggest an association between GLP-1 agonist use and acute pancreatitis; however, additional clinical trial data and in-depth case report analysis are needed to further evaluate and verify this finding. Topics: Acute Disease; Clinical Trials as Topic; Diabetes Mellitus, Type 2; Glucagon-Like Peptide 1; Humans; Hypoglycemic Agents; Pancreatitis | 2010 |
Neuro-modulation and bariatric surgery for type 2 diabetes mellitus.
Obesity has reached epidemic proportions and is continuing to grow into one of the leading healthcare issues worldwide. With this development, bariatric surgery has emerged as an acceptable treatment for morbid obesity, generally achieving meaningful and sustained weight loss. In a surprising turn of events, bariatric surgery was also found to be the most effective therapy for type 2 diabetes mellitus (T2DM). This observation has sparked a great deal of research that has improved our understanding of T2DM pathophysiology; it has facilitated the development of medical treatment and is expanding the indications for bariatric surgery. It was traditionally accepted that bariatric surgery causes weight loss by restriction of gastric volume, intestinal malabsorption, or a combination of the two. Laparoscopic adjustable gastric banding (LAGB) is considered a purely restrictive procedure that involves the placement of an adjustable band around the cardia of the stomach, creating a 15 ml pouch. Laparoscopic sleeve gastrectomy (LSG) is the resection of the fundus all along the greater curvature of the stomach. LSG was once considered a restrictive procedure, but this presumption has recently come under scrutiny. Bilio-pancreatic diversion (BPD) is an example of a procedure that was considered predominantly malabsorptive. In this operation, the ingested nutrients are diverted from the stomach to the ileum, bypassing a large segment of proximal bowel. Roux-en-Y gastric bypass (RYGB) traditionally combines both mechanisms, partitioning a small pouch from the proximal stomach and diverting the ingested nutrients to the jejunum with a roux-en-Y gastro-jejunostomy. However, recent investigation suggests additional mechanisms of action including hormonal. Today, RYGB is the procedure of choice for morbidly obese patients. The effect of bariatric surgery on T2DM was initially described in 1995 by Pories et al., who reported that there was an overall T2DM resolution after RYGB of 82.9% (1). A resolution rate of approximately 80% has been demonstrated repeatedly (2,3). The initial assumption was that the mechanism causing this effect was through weight loss. It is becoming evident that the anti-diabetic effect is not entirely weight loss as there is a consistent observation that the improvement of glucose and insulin levels occurs within days after RYGB, clearly too soon to be due to the weight loss (1,4). The ensuing body of literature has generated two leading theories att Topics: Animals; Bariatric Surgery; Diabetes Mellitus, Type 2; Glucagon-Like Peptide 1; Humans; Incretins; Obesity | 2010 |
Impact of GLP-1 and GLP-1 receptor agonists on cardiovascular risk factors in type 2 diabetes.
Type 2 diabetes (T2D) is associated with increased cardiovascular disease and mortality. Most diabetes treatments have not proven to reduce this risk and may be associated with worsening of specific cardiovascular risk factors. GLP-1 receptor agonists (GLP-1R agonists) are new incretin-based therapies for the treatment of T2D. They improve glucose control by stimulating insulin secretion and suppressing glucagon release, both in a glucose-dependent manner. There are two GLP-1R agonists approved for the treatment of T2D: once daily liraglutide and twice daily exenatide, both administered by sc injection. Based on recent clinical trials, GLP-1R agonists suggest having a protective role in cardiovascular risk factors besides improving glycemic control, compared to placebo and to standard diabetes therapies. Both liraglutide and exenatide have demonstrated to induce clinically significant weight loss and to reduce systolic blood pressure. Liraglutide also has a positive effect on the lipid profile and cardiovascular risk biomakers. Furthermore, recent data shows a direct effect of GLP-1 and its metabolites in the vascular endothelium and the myocardium, leading to vasodilator effects and improved cardiac function in humans with acute myocardial infarction or congestive heart failure. GLP-1R agonists have a positive impact on cardiovascular risk factors otherwise not addressed by most standard diabetes therapies. Whether these new compounds actually decrease cardiovascular disease and mortality remains to be demonstrated in outcome studies. Topics: Amino Acid Sequence; Animals; Cardiovascular Diseases; Diabetes Mellitus, Type 2; Glucagon-Like Peptide 1; Glucagon-Like Peptide-1 Receptor; Humans; Hypoglycemic Agents; Incretins; Models, Biological; Molecular Sequence Data; Receptors, Glucagon; Risk Factors | 2010 |
The physiologic role of incretin hormones: clinical applications.
Treatment of patients with type 2 diabetes mellitus (T2DM) traditionally has involved a progression of phases, from conventional lifestyle interventions and monotherapy, to combination therapy involving oral agents, to insulin initiation and its use either alone or with oral pharmacotherapy. Currently, the need for antidiabetic therapies with fewer adverse effects (eg, weight gain, reduced rates of hypoglycemia) is unmet. In addition, most treatments fail to adequately control postprandial hyperglycemia. Traditional options have generally been directed at the "insulin demand" aspect and have targeted insulin secretion or insulin resistance in peripheral tissues. Only recently have agents been available to address the "glucose supply" aspect that leads to fasting hyperglycemia in patients with T2DM. Incretin-based therapies, however, address both aspects. Two classes of incretin-directed therapies are available and work by either increasing endogenous levels of glucagon-like peptide-1 (GLP-1) (ie, dipeptidyl peptidase-4 inhibitors) or by mimicking the activity of endogenous GLP-1 (ie, GLP-1 agonists). These therapies treat the key metabolic abnormalities associated with T2DM but do so with reduced rates of hypoglycemia and do not promote weight gain as compared with conventional therapies. Topics: Adamantane; Diabetes Mellitus, Type 2; Dipeptides; Dipeptidyl-Peptidase IV Inhibitors; Disease Progression; Gastric Inhibitory Polypeptide; Glucagon-Like Peptide 1; Humans; Hyperglycemia; Incretins; Piperidines; Pyrazines; Sitagliptin Phosphate; Triazoles; Uracil | 2010 |
Bariatric surgery and the gut-brain communication--the state of the art three years later.
This review analyzes the literature concerning gut peptides and bariatric surgery, from 2005 to July 2009. In particular, we are interested in whether, and how, gastrointestinal peptide alterations following surgery interfere with appetite/satiety, and what role they might play in the resolution of comorbidities.. PubMed/MEDLINE and ISI Web of Knowledge were used to search for human studies concerning gut peptides profiles after any bariatric operation technique.. Most of the studies reviewed had longitudinal design, short follow-up, and low statistical power. The diversity of study results may be partially explained by methodological aspects. Glucagon-like peptide-1, gastric inhibitory peptide, and peptide YY alterations may contribute to the excellent results in glycemic control of diabetics. Results do vary depending on bariatric operation technique; this is particularly evident in the case of ghrelin, which has been much studied in recent years. Ghrelin suppression has been linked to increased satiety, alterations in energy homeostasis, and better glucose metabolism.. There is a lack of long-term data on gastrointestinal hormone profiles after bariatric surgery and the studies have many methodological pitfalls. We still need prospective, long-term, good methodological studies in this area. Topics: Appetite Regulation; Bariatric Surgery; Diabetes Mellitus, Type 2; Energy Metabolism; Gastric Inhibitory Polypeptide; Gastrointestinal Hormones; Ghrelin; Glucagon-Like Peptide 1; Glucose; Homeostasis; Humans; Obesity, Morbid; Peptide Hormones; Peptide YY; Satiation | 2010 |
Bariatric surgery and the gut hormone response.
Obesity has become an epidemic in the United States and is reaching epidemic levels in many other countries. Although obesity itself can have deleterious effects, the attributed comorbidities contribute greatly to the overall health decline of affected populations. Overweight and obese individuals are at increased risk for many diseases and health conditions. Medical, psychological, and endoscopic therapies for weight loss have been tried; however weight loss is usually only modest, with weight regain common. Bariatric surgery has been reported to be the most effective method for achieving major, long-term weight loss, with weight loss ranges of 35%-40% lasting as long as 15 years. Patients often lose weight at a rapid rate, with resolution or remission of many obesity-related comorbidities. Although the procedure itself plays a role in the weight loss after surgery, the resultant metabolic changes have been linked to alterations in the gut hormones. Although these changes have been the focus of much research, they are not completely understood. Two hypotheses have been proposed to explain this conflicting data. The hindgut hypothesis suggests that the quick transit of nutrients to the distal bowel improves glucose metabolism by stimulating secretion of glucagon-like peptide-1 and other appetite-suppressing gut peptides. The foregut hypothesis suggests that there is a yet unknown factor that promotes insulin resistance and type 2 diabetes mellitus. Further research is essential and could lead to less invasive therapies with fewer complications and side effects than bariatric surgery. Topics: Bariatric Surgery; Blood Glucose; Diabetes Mellitus, Type 2; Glucagon-Like Peptide 1; Gluconeogenesis; Humans; Insulin; Insulin Secretion; Intestine, Small; Obesity, Morbid; Weight Loss | 2010 |
The future use of liraglutide: implications of the LEAD-2 study for treatment guidelines in type 2 diabetes.
The effective identification and management of type 2 diabetes (T2D) in primary care is a healthcare priority. New antidiabetic agents, including glucagon-like peptide (GLP)-1 receptor agonists, may help overcome drawbacks with current treatments. These new agents have been reviewed in the updated National Institute for Health and Clinical Excellence (NICE) guidelines for the treatment of T2D. Liraglutide, a GLP-1 receptor agonist, was licensed for use in patients with T2D after the development of the NICE guidelines. Data from Phase III trials evaluating liraglutide are presented here in the context of the role of GLP-1 receptor agonists in NICE guidelines. Topics: Clinical Trials, Phase III as Topic; Diabetes Mellitus, Type 2; Europe; Evidence-Based Medicine; Glucagon-Like Peptide 1; Humans; Hypoglycemic Agents; Liraglutide; Practice Guidelines as Topic; Randomized Controlled Trials as Topic; Societies, Medical; Treatment Outcome; United States | 2010 |
Bile-induced secretion of glucagon-like peptide-1: pathophysiological implications in type 2 diabetes?
During the last decades it has become clear that bile acids not only act as simple fat solubilizers, but additionally represent complex hormonal metabolic integrators. Bile acids activate both nuclear receptors (controlling transcription of genes involved in for example bile acid, cholesterol, and glucose metabolism) and the cell surface G protein-coupled receptor TGR5 (modulating energy expenditure in brown fat and muscle cells). It has been shown that TGR5 is expressed in enteroendocrine L cells, which secrete the potent glucose-lowering incretin hormone glucagon-like peptide-1 (GLP-1). Recently it was shown that bile acid-induced activation of TGR5 results in intestinal secretion of GLP-1 and that enhanced TGR5 signaling improves postprandial glucose tolerance in diet-induced obese mice. This Perspectives article presents these novel findings in the context of prior studies on nutrient-induced GLP-1 secretion and outlines the potential implications of bile acid-induced GLP-1 secretion in physiological, pathophysiological, and pharmacological perspectives. Topics: Animals; Bile Acids and Salts; Diabetes Mellitus, Type 2; Glucagon-Like Peptide 1; Humans; Obesity; Postprandial Period; Receptors, G-Protein-Coupled | 2010 |
Is the diminished incretin effect in type 2 diabetes just an epi-phenomenon of impaired beta-cell function?
Topics: Diabetes Mellitus, Type 2; Gastric Inhibitory Polypeptide; Glucagon-Like Peptide 1; Humans; Incretins; Insulin-Secreting Cells; Models, Biological | 2010 |
Liraglutide for type 2 diabetes?
Several drugs that act on the incretin hormonal system are now licensed in the UK as add-on therapy for patients with type 2 diabetes mellitus and inadequate glycaemic control. Liraglutide (Victoza--Novo Nordisk) is a recently licensed long-acting glucagon-like peptide-1 (GLP-1) mimetic that can be given once daily as a subcutaneous injection, as part of either dual or triple therapy. Advertising claims that use of the drug leads to "reductions in weight"; "reductions in systolic blood pressure"; and "improvements in beta-cell function", as well as reductions in blood glucose concentrations. Here we assess the evidence for these claims and consider whether liraglutide has a role in the management of patients with type 2 diabetes. Topics: Diabetes Mellitus, Type 2; Exenatide; Glucagon-Like Peptide 1; Humans; Hypoglycemic Agents; Insulin; Liraglutide; Nausea; Peptides; Practice Guidelines as Topic; Venoms; Vomiting; Weight Loss | 2010 |
Glycaemic goals in patients with type 2 diabetes: current status, challenges and recent advances.
Recommendations for the management of type 2 diabetes include rigorous control of blood glucose levels and other risk factors, such as hypertension and dyslipidaemia. In clinical practice, many patients do not reach goals for glycaemic control. Causes of failure to control blood glucose include progression of underlying pancreatic beta-cell dysfunction, incomplete adherence to treatment (often because of adverse effects of weight gain and hypoglycaemia) and reluctance of clinicians to intensify therapy. There is increasing focus on strategies that offer potential to improve glycaemic control. Structured patient education has been shown to improve glycaemic control and other cardiovascular risk factors in people with type 2 diabetes. Payment of general practitioners by results has been shown to improve glycaemic control. New classes of glucose-lowering agents have expanded the treatment options available to clinicians and patients and include the dipeptidyl peptidase 4 (DPP-4) inhibitors and glucagon-like peptide-1 (GLP-1) receptor agonists. These new classes of therapy and other strategies outlined above could help clinicians to individualize treatment and help a greater proportion of patients to achieve long-term control of blood glucose. Topics: Adolescent; Adult; Aged; Blood Glucose; Cost-Benefit Analysis; Diabetes Mellitus, Type 2; Female; Glucagon-Like Peptide 1; Glycated Hemoglobin; Humans; Hypoglycemic Agents; Male; Middle Aged; Practice Guidelines as Topic; Quality of Life; Young Adult | 2010 |
Comparing the actions of older and newer therapies on body weight: to what extent should these effects guide the selection of antidiabetic therapy?
Type 2 diabetes patients are usually overweight or obese. Further weight gain induced by antidiabetic treatment should be avoided if possible. Much attention has been focussed recently on the potential for GLP-1 mimetics, in particular, to reduce weight.. Effects on weight are but one of several important criteria in selecting antidiabetic therapy, however. This review explores the effects on weight of older classes of antidiabetic agents (metformin, sulfonylureas, thiazolidinediones) and the newer drugs acting via the GLP-1 system. Other aspects of their therapeutic profiles and current therapeutic use are reviewed briefly to place effects on weight within a broader context.. Comparative trials demonstrated weight neutrality or weight reduction with metformin, and weight increases with a sulfonylurea or thiazolidinedione. There was no clinically significant change in weight with DPP-4 inhibitors and a small and variable decrease in weight (about 3 kg or less) with GLP-1 mimetics. Improved clinical outcomes have been demonstrated for metformin and a sulfonylurea (cardiovascular and microvascular benefits, respectively, in the UK Prospective Diabetes Study), and secondary endpoints improved modestly with pioglitazone in the PROactive trial. No outcome benefits have been demonstrated to date with GLP-1-based therapies, and these agents exert little effect on cardiovascular risk factors. Concerns remain over long-term safety of these agents and this must be weighed against any potential benefit on weight management.. Considering effects on weight within the overall risk-benefit profile of antidiabetic therapies, metformin continues to justify its place at the head of current management algorithms for type 2 diabetes, due to its decades-long clinical evidence base, cardiovascular outcome benefits and low cost. Topics: Blood Glucose; Body Weight; Decision Making; Diabetes Mellitus, Type 2; Diabetic Angiopathies; Dipeptidyl-Peptidase IV Inhibitors; Drug Therapy, Combination; Glucagon-Like Peptide 1; Humans; Hypoglycemic Agents; Incretins; Obesity; Randomized Controlled Trials as Topic; Treatment Outcome | 2010 |
Glycaemic control in acute coronary syndromes: prognostic value and therapeutic options.
Type 2 diabetes and acute coronary syndromes (ACS) are widely interconnected. Individuals with type 2 diabetes are more likely than non-diabetic subjects to experience silent or manifest episodes of myocardial ischaemia as the first presentation of coronary artery disease. Insulin resistance, inflammation, microvascular disease, and a tendency to thrombosis are common in these patients. Intensive blood glucose control with intravenous insulin infusion has been demonstrated to significantly reduce morbidity and mortality in critically ill hyperglycaemic patients admitted to an intensive care unit (ICU). Direct glucose toxicity likely plays a crucial role in explaining the clinical benefits of intensive insulin therapy in such critical patients. However, the difficult implementation of nurse-driven protocols for insulin infusion able to lead to rapid and effective blood glucose control without significant episodes of hypoglycaemia has led to poor implementations of insulin infusion protocols in coronary care units, and cardiologists now to consider alternative drugs for this purpose. New intravenous or oral agents include the incretin glucagon-like peptide 1 (GLP1), its analogues, and dipeptidyl peptidase-4 inhibitors, which potentiate the activity of GLP1 and thus enhance glucose-dependent insulin secretion. Improved glycaemic control with protective effects on myocardial and vascular tissues, with lesser side effects and a better therapeutic compliance, may represent an important therapeutic potential for this class of drugs in acutely ill patients in general and patients with ACS in particular. Such drugs should be known by practicing cardiologists for their possible use in ICUs in the years to come. Topics: Acute Coronary Syndrome; Blood Glucose; Diabetes Mellitus, Type 2; Diabetic Angiopathies; Glucagon-Like Peptide 1; Humans; Hypoglycemic Agents; Incretins; Prognosis | 2010 |
Managing type 2 diabetes in the primary care setting: beyond glucocentricity.
Successful management of type 2 diabetes mellitus (T2DM) requires attention to additional conditions often associated with hyperglycemia including overweight or obesity, dyslipidemia and hypertension, as each has some relationship with microvascular or macrovascular complications. Because control of cardiovascular risk factors is as important as glucose control in T2DM, these risk factors need to be addressed, and it is critical that antidiabetes medications do not exacerbate these risk factors. A patient-centered approach to treatment in which clinicians maximize patient involvement in the selection of antidiabetes therapy may lead to increased adherence and improved clinical outcomes. The incretin hormones, which include glucagon-like peptide-1 (GLP-1), are involved in glucoregulation and have become an important focus of T2DM research and treatment. Incretin-based therapies, such as the glucagon-like peptide-1 receptor agonists and the dipeptidyl peptidase-IV inhibitors, have shown beneficial effects on hyperglycemia, weight, blood pressure and lipids with a low incidence of hypoglycemia. Topics: Adamantane; Blood Glucose; Diabetes Mellitus, Type 2; Dipeptides; Dipeptidyl-Peptidase IV Inhibitors; Exenatide; Glucagon-Like Peptide 1; Humans; Hyperglycemia; Hypoglycemic Agents; Liraglutide; Nitriles; Obesity; Patient Compliance; Peptides; Piperidines; Precision Medicine; Primary Health Care; Pyrazines; Pyrrolidines; Risk Factors; Sitagliptin Phosphate; Triazoles; Uracil; Venoms; Vildagliptin | 2010 |
Bariatric surgery for type 2 diabetes: weighing the impact for obese patients.
Obesity is a potent risk factor for the development and progression of type 2 diabetes, and weight loss is a key component of diabetes management. Bariatric surgery results in significant weight loss and remission of diabetes in most patients. After surgery, glycemic control is restored by a combination of enforced caloric restriction, enhanced insulin sensitivity, and increased insulin secretion. Topics: Bariatric Surgery; Body Mass Index; Caloric Restriction; Diabetes Mellitus, Type 2; Disease Management; Disease Progression; Gastric Bypass; Gastric Inhibitory Polypeptide; Glucagon-Like Peptide 1; Humans; Insulin; Insulin Resistance; Insulin Secretion; Risk Factors; Weight Loss | 2010 |
A meta-analysis of placebo-controlled clinical trials assessing the efficacy and safety of incretin-based medications in patients with type 2 diabetes.
A systematic review of the literature, in combination with a meta-analysis of randomized controlled trials comparing treatments with placebo, was conducted to provide an update on the clinical efficacy and safety of incretin-based medications in adult patients with type 2 diabetes.. A literature search (2000-2009) identified 38 placebo-controlled trials (phase II or later - parallel design) comparing exenatide (n = 8), liraglutide (n = 7), vildagliptin (n = 11) and sitagliptin (n = 12) with placebo. Outcomes were change from baseline in HbA(1c) and in weight, and the number of patient-reported hypoglycemic episodes. HbA(1c) and weight outcomes were analyzed as weighted mean differences (WMD), and the number of hypoglycemic episodes as relative risks (RR).. Patients receiving liraglutide showed greater reduction in HbA(1c) in comparison to placebo (WMD = -1.03, 95% confidence interval, CI = -1.16 to -0.90, p < 0.001) than those on sitagliptin (WMD = -0.79, 95% CI = -0.93 to -0.65, p < 0.001), exenatide (WMD = -0.75, 95% CI = -0.83 to -0.67, p < 0.001) or vildagliptin (WMD = -0.67, 95% CI = -0.83 to -0.52, p < 0.001). Weight was statistically significantly negatively associated with exenatide (WMD = -1.10, 95% CI = -1.32 to -0.87, p < 0.001) and positively associated with sitagliptin (WMD = 0.60, 95% CI = 0.33-0.87, p < 0.001) and vildagliptin (WMD = 0.56, 95% CI = 0.27-0.84, p < 0.001). The number of patient-reported hypoglycemic episodes was statistically significantly associated with the use of sitagliptin (RR = 2.56, 95% CI = 1.23-5.33, p = 0.01) and exenatide (RR = 2.40, 95% CI = 1.30-4.11, p = 0.002).. Incretin-based therapies are effective in glycemic control and also offer other advantages such as weight loss (exenatide and liraglutide). This may have an important impact on patient adherence to medication. Topics: Adamantane; Adult; Diabetes Mellitus, Type 2; Dipeptidyl-Peptidase IV Inhibitors; Drug Therapy, Combination; Exenatide; Glucagon-Like Peptide 1; Glycated Hemoglobin; Humans; Hypoglycemia; Hypoglycemic Agents; Liraglutide; Nitriles; Peptides; Pyrazines; Pyrrolidines; Sitagliptin Phosphate; Triazoles; Venoms; Vildagliptin; Weight Loss | 2010 |
Incretin agents in type 2 diabetes.
To evaluate the emerging classes of antihyperglycemic agents that target the incretin pathway, including their therapeutic efficacy and side effect profiles, in order to help identify their place among the treatment options for patients with type 2 diabetes.. MEDLINE, EMBASE, and the Cochrane Database of Systematic Reviews were searched. Most evidence is level I and II.. Two classes of incretin agents are currently available: glucagonlike peptide 1 (GLP1) receptor agonists and dipeptidyl peptidase 4 (DPP4) inhibitors, both of which lower hyperglycemia considerably without increasing the risk of hypoglycemia. The GLP1 receptor agonists have a greater effect on patients' glycated hemoglobin A(1c) levels and cause sustained weight loss, whereas the DPP4 inhibitors are weight-neutral.. The GLP1 and DPP4 incretin agents, promising and versatile antihyperglycemic agents, are finding their way into the therapeutic algorithm for treating type 2 diabetes. They can be used in patients not adequately controlled by metformin monotherapy or as initial therapy in those for whom metformin is contraindicated. Topics: Adult; Clinical Trials as Topic; Diabetes Mellitus, Type 2; Dipeptidyl-Peptidase IV Inhibitors; Dose-Response Relationship, Drug; Evidence-Based Medicine; Exenatide; Glucagon-Like Peptide 1; Glucose; Humans; Hyperglycemia; Hypoglycemic Agents; Incretins; Liraglutide; Peptides; Venoms | 2010 |
Incretin physiology and its role in type 2 diabetes mellitus.
Incretins are hormones that are released after ingestion of a meal and augment the secretion of insulin. Current research suggests that GLP-1 (glucagon-like peptide 1) is the most important. Their action is terminated by enzymes known as dipeptidyl peptidase-4 (DPP-4). The observation that the incretin response may be diminished in individuals with type 2 diabetes mellitus has led to advances in the management of this disease. Agents that act as incretin mimetics, such as exenatide and liraglutide, and DPP-4 inhibitors, such as sitagliptin phosphate and saxagliptin, improve glycated hemoglobin levels either as monotherapy or in combination with other agents. Importantly, these agents either lead to weight loss or are weight neutral and are associated with a low risk of hypoglycemia--properties that further contribute to their clinical utility. Topics: Adamantane; Diabetes Mellitus, Type 2; Dipeptides; Dipeptidyl-Peptidase IV Inhibitors; Exenatide; Glucagon; Glucagon-Like Peptide 1; Humans; Hypoglycemic Agents; Incretins; Insulin; Liraglutide; Peptides; Pyrazines; Sitagliptin Phosphate; Triazoles; Venoms | 2010 |
Newer agents for blood glucose control in type 2 diabetes: systematic review and economic evaluation.
In May 2008, the National Institute for Health and Clinical Excellence (NICE) issued an updated guideline [clinical guideline (CG) 66] for the management of all aspects of type 2 diabetes. This report aims to provide information on new drug developments to support a 'new drugs update' to the 2008 guideline.. To review the newer agents available for blood glucose control in type 2 diabetes from four classes: the glucagon-like peptide-1 (GLP-1) analogue exenatide; dipeptidyl peptidase-4 (DPP-4) inhibitors sitagliptin and vildagliptin; the long-acting insulin analogues, glargine and detemir; and to review concerns about the safety of the thiazolidinediones.. The following databases were searched: MEDLINE (1990-April 2008), EMBASE (1990-April 2008), the Cochrane Library (all sections) Issue 2, 2008, and the Science Citation Index and ISI Proceedings (2000-April 2008). The websites of the American Diabetes Association, the European Association for the Study of Diabetes, the US Food and Drug Administration, the European Medicines Evaluation Agency and the Medicines and Healthcare Products Regulatory Agency were searched, as were manufacturers' websites.. Data extraction was carried out by one person, and checked by a second. Studies were assessed for quality using standard methods for reviews of trials. Meta-analyses were carried out using the Cochrane Review Manager (RevMan) software. Inclusion and exclusion criteria were based on current standard clinical practice in the UK, as outlined in NICE CG 66. The outcomes for the GLP-1 analogues, DPP-4 inhibitors and the long-acting insulin analogues were: glycaemic control, reflected by glycated haemoglobin (HbA1c) level, hypoglycaemic episodes, changes in weight, adverse events, quality of life and costs. Modelling of the cost-effectiveness of the various regimes used the United Kingdom Prospective Diabetes Study (UKPDS) Outcomes Model.. Exenatide improved glycaemic control by around 1%, and had the added benefit of weight loss. The gliptins were effective in improving glycaemic control, reducing HbA1c level by about 0.8%. Glargine and detemir were equivalent to Neutral Protamine Hagedorn (NPH) (and to each other) in terms of glycaemic control but had modest advantages in terms of hypoglycaemia, especially nocturnal. Detemir, used only once daily, appeared to cause slightly less weight gain than glargine. The glitazones appeared to have similar effectiveness in controlling hyperglycaemia. Both can cause heart failure and fractures, but rosiglitazone appears to slightly increase the risk of cardiovascular events whereas pioglitazone reduces it. Eight trials examined the benefits of adding pioglitazone to an insulin regimen; in our meta-analysis, the mean reduction in HbA1c level was 0.54% [95% confidence interval (CI) -0.70 to -0.38] and hypoglycaemia was marginally more frequent in the pioglitazone arms [relative risk (RR) 1.27, 95% CI 0.99 to 1.63]. In most studies, those on pioglitazone gained more weight than those who were not. In terms of annual drug acquisition costs among the non-insulin regimes for a representative patient with a body mass index of around 30 kg/m2, the gliptins were the cheapest of the new drugs, with costs of between 386 pounds and 460 pounds. The glitazone costs were similar, with total annual costs for pioglitazone and for rosiglitazone of around 437 pounds and 482 pounds, respectively. Exenatide was more expensive, with an annual cost of around 830 pounds. Regimens containing insulin fell between the gliptins and exenatide in terms of their direct costs, with a NPH-based regimen having an annual cost of around 468 pounds for the representative patient, whereas the glargine and detemir regimens were more expensive, at around 634 pounds and 716 pounds, respectively. Comparisons of sitagliptin and rosiglitazone, and of vidagliptin and pioglitazone slowed clinical equivalence in terms of quality-adjusted life-years (QALYs), but the gliptins were marginally less costly. Exenatide, when compared with glargine, appeared to be cost-effective. Comparing glargine with NPH showed an additional anticipated cost of around 1800 pounds. Within the comparison of detemir and NPH, the overall treatment costs for detemir were slightly higher, at between 2700 pounds and 2600 pounds.. The UKPDS Outcomes Model does not directly address aspects of the treatments under consideration, for example the direct utility effects from weight loss or weight gain, severe hypoglycaemic events and the fear of severe hypoglycaemic events. Also, small differences in QALYs among the drugs lead to fluctuations in incremental cost-effectiveness ratios.. Exenatide, the gliptins and detemir were all clinically effective. The long-acting insulin analogues glargine and detemir appeared to have only slight clinical advantages over NPH, but had much higher costs and did not appear to be cost-effective as first-line insulins for type 2 diabetes. Neither did exenatide appear to be cost-effective compared with NPH but, when used as third drug after failure of dual oral combination therapy, exenatide appeared cost-effective relative to glargine in this analysis. The gliptins are similar to the glitazones in glycaemic control and costs, and appeared to have fewer long-term side effects. Therefore, it appears, as supported by recent NICE guidelines, that NPH should be the preferred first-line insulin for the treatment of type 2 diabetes. More economic analysis is required to establish when it becomes cost-effective to switch from NPH to a long-acting analogue. Also, long-term follow-up studies of exenatide and the gliptins, and data on combined insulin and exenatide treatment, would be useful. Topics: Adamantane; Body Weight; Cost-Benefit Analysis; Diabetes Mellitus, Type 2; Dipeptidyl-Peptidase IV Inhibitors; Exenatide; Glucagon-Like Peptide 1; Glycated Hemoglobin; Humans; Hypoglycemic Agents; Insulin; Insulin Glargine; Insulin, Long-Acting; Nitriles; Peptides; Pyrazines; Pyrrolidines; Quality of Life; Randomized Controlled Trials as Topic; Sitagliptin Phosphate; State Medicine; Thiazolidinediones; Triazoles; United Kingdom; Venoms; Vildagliptin | 2010 |
Liraglutide: a once-daily human glucagon-like peptide-1 analogue for type 2 diabetes mellitus.
The pharmacology, pharmacokinetics, efficacy, safety, dosage and administration, adverse effects, and place in therapy of liraglutide, a glucagon-like peptide-1 (GLP-1) receptor agonist, are reviewed.. Liraglutide, the first once-daily human GLP-1 analogue, retains 97% homology with the endogenous hormone and shares its glucose-dependent glucose-lowering action but has a considerably longer half-life that supports once-daily dosing. After promising Phase II study results, the Liraglutide Effect and Action in Diabetes (LEAD) Phase III clinical development program, involving more than 4000 patients worldwide, investigated the efficacy and tolerability of liraglutide 1.2 or 1.8 mg daily (n = 2735) as monotherapy and in combination with various oral antidiabetic drugs. The LEAD studies yielded encouraging results indicating that patients receiving liraglutide could expect to attain glycosylated hemoglobin reductions of about 1-1.5% and fasting plasma glucose reductions of 15-43 mg/dL. Loss of body weight was consistent throughout the studies: when using liraglutide 1.8 mg as monotherapy, patients lost a mean of 2.5 kg over a 52-week period. Accompanying reductions in some cardiovascular risk endpoints, such as systolic blood pressure, were also observed. By virtue of its glucose-dependent mode of action, liraglutide was generally well tolerated in clinical trials, with only very rare episodes of major hypoglycemia reported. The most frequently observed adverse effects were gastrointestinal, with 10-40% of patients experiencing an episode of nausea, which was often mild or moderate in severity and transient in nature.. Liraglutide is efficacious and well tolerated in patients with type 2 diabetes and has been found to reduce weight and blood pressure. Topics: Diabetes Mellitus, Type 2; Drug Administration Schedule; Glucagon-Like Peptide 1; Humans; Hypoglycemic Agents; Liraglutide | 2010 |
Current research of the RAS in diabetes mellitus.
Topics: Animals; Biomedical Research; Diabetes Mellitus, Type 2; Glucagon-Like Peptide 1; Humans; Renin-Angiotensin System; Vitamin D | 2010 |
DPP-4 inhibitors: what may be the clinical differentiators?
Attenuation of the prandial incretin effect, mediated by glucagon-like peptide-1 (GLP-1) and glucose-dependent insulinotropic peptide (GIP), contributes to hyperglycemia in type 2 diabetes mellitus (T2DM). Since the launch of sitagliptin in 2006, a compelling body of evidence has accumulated showing that dipeptidyl peptidase-4 (DPP-4) inhibitors, which augment endogenous GLP-1 and GIP levels, represent an important advance in the management of T2DM. Currently, three DPP-4 inhibitors - sitagliptin, vildagliptin and saxagliptin - have been approved in various countries worldwide. Several other DPP-4 inhibitors, including linagliptin and alogliptin, are currently in clinical development. As understanding of, and experience with, the growing number of DPP-4 inhibitors broadens, increasing evidence suggests that the class may offer advantages over other antidiabetic drugs in particular patient populations. The expanding evidence base also suggests that certain differences between DPP-4 inhibitors may prove to be clinically significant. This therapeutic diversity should help clinicians tailor treatment to the individual patient, thereby increasing the proportion that safely attain target HbA(1c) levels, and reducing morbidity and mortality. This review offers an overview of DPP-4 inhibitors in T2DM and suggests some characteristics that may provide clinically relevant differentiators within this class. Topics: Adamantane; Blood Glucose; Diabetes Mellitus, Type 2; Dipeptides; Dipeptidyl Peptidase 4; Dipeptidyl-Peptidase IV Inhibitors; Energy Intake; Gastric Emptying; Glucagon-Like Peptide 1; Glycated Hemoglobin; Humans; Hyperglycemia; Hypoglycemic Agents; Incretins; Intestinal Mucosa; Linagliptin; Neurons; Nitriles; Piperidines; Purines; Pyrazines; Pyrrolidines; Quinazolines; Sitagliptin Phosphate; Triazoles; Uracil; Vildagliptin | 2010 |
Genetic variants affecting incretin sensitivity and incretin secretion.
Recent genome-wide association studies identified several novel risk genes for type 2 diabetes. The majority of these type 2 diabetes risk variants confer impaired pancreatic beta cell function. Though the molecular mechanisms by which common genetic variation within these loci affects beta cell function are not completely understood, risk variants may alter glucose-stimulated insulin secretion, proinsulin conversion, and incretin signals. In humans, the incretin effect is mediated by the secretion and insulinotropic action of two peptide hormones, glucose-dependent insulinotropic polypeptide and glucagon-like peptide-1. This review article aims to give an overview of the type 2 diabetes risk loci that were found to associate with incretin secretion or incretin action, paying special attention to the potential underlying mechanisms. Topics: Animals; Diabetes Mellitus, Type 2; Gastric Inhibitory Polypeptide; Genome-Wide Association Study; Glucagon-Like Peptide 1; Humans; Incretins; Insulin-Secreting Cells | 2010 |
The safety and tolerability of GLP-1 receptor agonists in the treatment of type-2 diabetes.
Established therapies for type-2 diabetes effectively reduce blood glucose, but are often associated with adverse effects that pose risks to patient's health or diminish adherence to treatment. Weight gain, hypoglycaemia and gastrointestinal symptoms are commonly reported and some agents may not be safe for use in patients with renal impairment or elevated cardiovascular risk. New treatments based on the action of the endogenous human hormone glucagon-like peptide-1 (GLP-1), including exenatide and liraglutide, are available. These therapies provide a novel pharmacological approach to glycaemic control via multiple mechanisms of action, and accordingly exhibit different safety and tolerability profiles than conventional treatments. GLP-1 receptor agonists stimulate insulin release only in the presence of elevated blood glucose and are therefore associated with a fairly low risk of hypoglycaemia. Gastrointestinal symptoms are common but transient, and there appears to be little potential for interaction with other drugs. GLP-1 receptor agonists are associated with weight loss rather than weight gain. As protein-based therapies, these agents have the potential to induce antibody formation, but the impact on efficacy and safety is minor. GLP-1 receptor agonists thus offer a new and potentially useful option for clinicians concerned about some of the common adverse effects of type-2 diabetes therapies. Topics: Chemical and Drug Induced Liver Injury; Diabetes Mellitus, Type 2; Drug Interactions; Gastrointestinal Diseases; Glucagon-Like Peptide 1; Glucagon-Like Peptide-1 Receptor; Heart Diseases; Humans; Hypoglycemia; Hypoglycemic Agents; Incretins; Insulin; Kidney Diseases; Pancreatitis; Receptors, Glucagon; Sulfonylurea Compounds; Thiazolidinediones; Thyroid Diseases | 2010 |
Liraglutide. Type 2 diabetes: more prudent to continue using exenatide.
When patients with type 2 diabetes fail to achieve strict HbA1c control with oral glucose-lowering drugs, insulin is the standard recourse. Exenatide, an injectable incretin analogue, should only be used when weight gain is a major problem. Liraglutide is another injectable incretin analogue recently authorised for use in this setting. Two randomised unblinded trials, one versus insulin glargine in 581 patients and the other versus exenatide in 464 patients, suggest that liraglutide has a slightly more potent effect on glycaemia. Weight loss was similar in the liraglutide and exenatide groups. In a trial including 1091 patients, liraglutide was not more or less effective than glimepiride on glycaemia. Like exenatide, liraglutide can cause pancreatitis. In the trial comparing liraglutide versus exenatide, one-quarter of patients experienced nausea. There is more evidence of a risk of thyroid cancer with liraglutide than with exenatide. Liraglutide is administered as a single daily subcutaneous injection, whereas exenatide requires two daily injections. In practice, when prescribing an incretin analogue seems justified, it is more prudent to continue using exenatide, while closely monitoring patients for adverse effects. Topics: Animals; Clinical Trials as Topic; Diabetes Mellitus, Type 2; Exenatide; Glucagon-Like Peptide 1; Humans; Liraglutide; Peptides; Sulfonylurea Compounds; Thyroid Neoplasms; Venoms | 2010 |
Incretin-based therapies in the management of type 2 diabetes: rationale and reality in a managed care setting.
In addition to the hypoglycemia and weight gain associated with many treatments for type 2 diabetes, alpha-glucosidase inhibitors, thiazolidinediones, metformin, sulfonylureas, and the glinides do not address all of the multiple defects existing in the pathophysiology of the disease. Cumulatively, these oral agents address the influx of glucose from the gastrointestinal tract, impaired insulin activity, and acute beta-cell dysfunction in type 2 diabetes; however, until recently, there were no means to deal with the inappropriate hyperglucagonemia or chronic beta-cell-decline characteristic of the disease. The recently introduced incretin-based therapies serve to address some of the challenges associated with traditionally available oral antidiabetic agents. In addition to improving beta-cell function, stimulating insulin secretion, and inhibiting glucagon secretion, these agents reduce appetite, thereby stabilizing weight and/or promoting weight loss in patients with type 2 diabetes. Of the incretin-based therapies, both the dipeptidyl peptidase-4 (DPP-4) inhibitors and the glucagon-like peptide-1 (GLP-1) receptor agonists stimulate insulin secretion and inhibit glucagon secretion. The subsequent review outlines evidence from selected clinical trials of the currently available GLP-1 receptor agonists, exenatide and liraglutide, and DPP-4 inhibitors, sitagliptin and saxagliptin. Earlier and more frequent use of these incretin-based therapies is recommended in the treatment of type 2 diabetes, based on their overall safety and ability to achieve the glycosylated hemoglobin level goal. As such, both the American Diabetes Association and the American Association of Clinical Endocrinologists/American College of Endocrinology (AACE/ACE) treatment algorithms recommend the use of incretin-based therapy in both treatment-naive and previously treated patients. The AACE/ACE guidelines clearly state that these agents should not be limited to third- or fourth-line therapy. Topics: Adamantane; Algorithms; Diabetes Mellitus, Type 2; Dipeptides; Dipeptidyl-Peptidase IV Inhibitors; Evidence-Based Medicine; Exenatide; Glucagon; Glucagon-Like Peptide 1; Glucagon-Like Peptide-1 Receptor; Glycated Hemoglobin; Humans; Hypoglycemic Agents; Incretins; Insulin; Insulin Secretion; Liraglutide; Managed Care Programs; Peptides; Pyrazines; Receptors, Glucagon; Sitagliptin Phosphate; Triazoles; Venoms | 2010 |
Improving treatment success rates for type 2 diabetes: recommendations for a changing environment.
As demonstrated by suboptimal levels of therapeutic goal achievement, there exists significant room for improvement in type 2 diabetes management. Despite widespread disease awareness and high rates of risk-factor testing in managed care, effective metabolic control in patients with type 2 diabetes is lacking and points toward a phenomenon known as clinical inertia. Clinical inertia, defined as a failure to initiate or advance therapy in a patient who is not at the evidence-based goal, is a key contributing factor in the suboptimal rates of therapeutic target achievement for type 2 diabetes. The causes of clinical inertia are multifactorial and interactive, arising among patients, providers, and health systems and from specific characteristics of available treatments. Therapeutic nonadherence is perhaps the most significant factor contributing to clinical inertia, with recent analyses demonstrating that providers are more likely to prescribe a dose escalation in patients who are adherent to therapy compared with those who are not. While the concept may be counterintuitive, antihyperglycemic agents also have the potential to cause or contribute to the phenomenon of clinical inertia. This often occurs via factors inherent to the drugs themselves, such as treatment-related adverse effects (eg, hypoglycemia, weight gain, edema, gastrointestinal symptoms), perception of long-term safety profiles, and the complexity of the treatment regimen. Often not considered, but equally important, is the durability of an antihyperglycemic agent to maintain glycosylated hemoglobin (A1C) level goals. Because no monotherapy exists to arrest the pancreatic beta-cell failure of type 2 diabetes, early combination therapy with thiazolidinediones and glucagon-like protein-1 agonists that is associated with sustained A1C level reduction is the only hope to change the progressive nature of type 2 diabetes mellitus. Topics: Algorithms; Decision Support Systems, Clinical; Diabetes Mellitus, Type 2; Dipeptidyl-Peptidase IV Inhibitors; Disease Progression; Glucagon-Like Peptide 1; Glycated Hemoglobin; Humans; Hypoglycemic Agents; Managed Care Programs; Practice Guidelines as Topic; Risk Factors; Treatment Failure; Treatment Outcome | 2010 |
Emerging treatment options for type 2 diabetes.
Type 2 diabetes mellitus (T2DM) is rapidly increasing in prevalence and is a major public health problem. It is a progressive disease which commonly requires multiple pharmacotherapy. Current options for treatment may have undesirable side effects (particularly weight gain and hypoglycaemia) and contraindications, and little effect on disease progression. Incretin based therapy is one of several newer therapies to improve glycaemia and is available in two different forms, dipeptidyl peptidase-4 (DPP-4) inhibitors and glucagon-like peptide-1 (GLP-1) agonists. Use of these agents results in a 'glucose-dependant' increase in insulin secretion and glucagon suppression resulting in improved glycaemia with low incidence of hypoglycaemia. DPP-4 inhibitors are oral drugs which are weight neutral, while GLP-1 agonists are injected subcutaneously and help promote weight loss while improving glycaemia. GLP-1 agonists have also been shown to increase beta cell mass in rat models. Bariatric surgery is another option for the obese patient with T2DM, with blood glucose normalizing in over half of the patients following surgery. Other therapies in development for the treatment of T2DM include sodium-glucose transporter 2 (SGLT-2) inhibitors, glucagon receptor antagonists, glucokinase activators and sirtuins. In this article, we will review the various existing and emerging treatment options for T2DM. Topics: Animals; Bariatric Surgery; Diabetes Mellitus, Type 2; Dipeptidyl-Peptidase IV Inhibitors; Glucagon-Like Peptide 1; Humans; Hypoglycemic Agents; Incretins; Obesity; Sodium-Glucose Transporter 2 Inhibitors | 2010 |
The glucose triad and its role in comprehensive glycaemic control: current status, future management.
The prevalence of type 2 diabetes across the world has been described as a global pandemic. Despite significant efforts to limit both the increase in the number of cases and the long-term impact on morbidity and mortality, the total number of people with diabetes is projected to continue to rise and most patients still fail to achieve adequate glycaemic control. Optimal management of type 2 diabetes requires an understanding of the relationships between glycosylated haemoglobin (HbA(1c)), fasting plasma glucose and postprandial glucose (the glucose triad), and how these change during development and progression of the disease. Early and sustained control of glycaemia remains important in the management of type 2 diabetes. The contribution of postprandial glucose levels to overall glycaemic control and the role of postprandial glucose targets in disease management are currently debated. However, many patients do not reach HbA(1C) targets set according to published guidelines. As recent data suggest, if driving HbA(1C) down to lower target levels is not the answer, what other factors involved in glucose homeostasis can or should be targeted? Has the time come to change the treatment paradigm to include awareness of the components of the glucose triad, the existence of glucose variability and their potential influence on the choice of pharmacological treatment? It is becomingly increasingly clear that physicians are likely to have to consider plasma glucose levels both after the overnight fast and after meals as well as the variability of glucose levels, in order to achieve optimal glycaemic control for each patient. When antidiabetic therapy is initiated, physicians may need to consider selection of agents that target both fasting and postprandial hyperglycaemia. Topics: Blood Glucose; Diabetes Mellitus, Type 2; Fasting; Glucagon-Like Peptide 1; Glycated Hemoglobin; Homeostasis; Humans; Hyperglycemia; Postprandial Period | 2010 |
Oral hypoglycaemics - a review of the evidence.
The range of oral hypoglycaemic agents (OHAs) has increased from one insulin sensitiser (metformin) and one class of insulin secretagogues (sulphonylureas) with the addition of further class of insulin secretagogues (glitinides), a further class of insulin sensitisers (glitazones) and two new classes: an alpha glycosidase inhibitor and glucagon-like peptide agents. Recent data has influenced the recommended sequence and usage of OHAs and glycaemic targets.. This article reviews the recent evidence in type 2 diabetes about the pros and cons of oral hypoglycaemic agents and the benefits and costs of intensive glycaemic control. It suggests a stepwise approach to glycaemic control with OHAs according to the evidence base currently available.. Before 2008, the recommended glycaemic management was healthy lifestyle, metformin and sulphonylurea if tolerated, then rosiglitazone or insulin. Pioglitazone could be used with insulin therapy but not as triple therapy. In 2007 and 2008 data about glitazones demonstrated a potential increased risk of myocardial infarction with rosiglitazone and increased risk of heart failure, peripheral fractures and macular oedema with both pioglitazone and rosiglitazone. In 2009 a new class of hypoglycaemic agents, glucagon-like peptide 1 agents, became available. Three trials published in 2009 failed to show a statistically significant reduction in cardiovascular events with intensive glycaemic management compared to conventional management. The current recommended target for HbA1c is <7% but higher or lower targets may be appropriate for individual patients. Topics: Administration, Oral; Diabetes Mellitus, Type 2; Dipeptidyl-Peptidase IV Inhibitors; Glucagon-Like Peptide 1; Glycated Hemoglobin; Humans; Hypoglycemic Agents; Life Style; Risk Factors; Sulfonylurea Compounds; Thiazolidinediones | 2010 |
Alogliptin: a novel molecule for improving glycemic control in type II diabetes mellitus.
Type 2 diabetes mellitus causes significant morbidity and mortality on account of its progressive nature and results in considerable burden on healthcare resources. It is characterized by high circulating levels of glucose resulting from insulin resistance and impaired insulin secretion. Current treatment strategies have only limited long-term efficacy and tolerability given the progressive nature of the disease leading to inadequate glycemic control and are also associated with undesirable side effects such as weight gain, hypoglycemia and gastrointestinal distress. In the light of these existing limitations, exploring new treatment targets and new therapies have become the need of the hour at present. The incretin pathway, in particular, glucagon-like peptide (GLP-1), plays an important pathological role in the development of type 2 diabetes mellitus, and treatments targeting the incretin system have recently generated surmount interest. These can mainly be categorized into two broad classes; GLP-1 agonists/analogs (exenatide, liraglutide), and dipeptidyl peptidase- 4 inhibitors (sitagliptin, vildagliptin). The gliptins act by prolonging the action of incretins, the gut hormones which can boost insulin levels. Alogliptin is a potent, highly selective dipeptidyl peptidase-4 inhibitor now undergoing clinical testing to support a new drug application for the treatment of type 2 diabetes. The results of Phase II and Phase III human studies, upon evaluation for clinical efficacy, safety and tolerability in patients with type 2 diabetes, have demonstrated that Alogliptin is effective and well tolerated as a treatment for type 2 diabetes, either as monotherapy or in combination with metformin, thiazolidinediones, sulfonylureas and insulin, with an excellent safety profile. Topics: Animals; Blood Glucose; Clinical Trials as Topic; Diabetes Mellitus, Type 2; Dipeptidyl-Peptidase IV Inhibitors; Drug Interactions; Glucagon-Like Peptide 1; Glucagon-Secreting Cells; Humans; Incretins; Insulin-Secreting Cells; Piperidines; Structure-Activity Relationship; Uracil | 2010 |
Liraglutide: the therapeutic promise from animal models.
To review the differences between the human glucagon-like peptide-1 (GLP-1) molecule and the analogue liraglutide, and to summarise key data from the liraglutide preclinical study programme showing the therapeutic promise of this new agent.. Liraglutide is a full agonist of the GLP-1 receptor and shares 97% of its amino acid sequence identity with human GLP-1. Unlike human GLP-1, however, liraglutide binds reversibly to serum albumin, and thus has increased resistance to enzymatic degradation and a longer half-life. In preclinical studies, liraglutide demonstrated good glycaemic control, mediated by the glucose-dependent stimulation of insulin and suppression of glucagon secretion and by delayed gastric emptying. Liraglutide also had positive effects on body weight, beta-cell preservation and mass, and cardiac function.. The therapeutic promise of liraglutide is evident from preclinical data. Liraglutide showed the potential to provide good glycaemic control without increasing the risk of hypoglycaemia and, as with exenatide, but not dipeptidyl peptidase-4 inhibitors, to mediate weight loss. Although these benefits have subsequently been studied clinically, beta-cell mass can be directly studied only in animal models. In common with other incretin-based therapies, liraglutide showed the potential to modulate the progressive loss of beta-cell function that drives the continuing deterioration in glycaemic control in patients with type 2 diabetes. Body weight was lowered by a mechanism involving mainly lowered energy intake, but also potentially altered food preference and maintained energy expenditure despite weight loss. Topics: Animals; Body Weight; Diabetes Mellitus, Type 2; Dipeptidyl-Peptidase IV Inhibitors; Exenatide; Glucagon; Glucagon-Like Peptide 1; Glucagon-Like Peptide-1 Receptor; Glycated Hemoglobin; Humans; Hypoglycemic Agents; Insulin; Insulin-Secreting Cells; Liraglutide; Mice; Mice, Obese; Peptides; Rats; Rats, Zucker; Receptors, Glucagon; Swine; Swine, Miniature; Venoms | 2010 |
Early clinical studies with liraglutide.
To describe Phase 1 and 2 clinical trials of liraglutide with a focus on clinical pharmacology.. In early clinical trials of liraglutide, 0.05-1.9 mg daily improved multiple aspects of glycaemic control and beta-cell function. Early trials demonstrated typical reductions in glycated haemoglobin (HbA(1c) ) and fasting plasma glucose (FPG) of up to 1.5% and 3.3-3.9 mmol/l, respectively, at daily doses of 1.25-1.9 mg, with 45-50% of patients reaching HbA(1c) < 7%. The effects of liraglutide in restoring beta-cell response to fasting and postprandial hyperglycaemia and in reinstating near-normal insulin secretion under hyperglycaemic conditions suggest a beta-cell-protective effect. By delaying gastric emptying and promoting satiety, liraglutide is weight sparing at low doses and causes clinically meaningful weight loss at higher doses and in combination with other anti-diabetes therapies with weight-modifying benefits, such as metformin. Significant improvements in other cardiovascular risk factors, including blood pressure, lipids and cardiovascular risk biomarkers, were also evident. Adverse effects of liraglutide were primarily gastrointestinal; dose-dependent nausea was the most commonly reported effect, but was typically mild-to-moderate in severity and transient in nature.. Early clinical trials of liraglutide indicate the ability to improve glycaemic control in a glucose-dependent manner, with low risk of hypoglycaemia. Promotion of weight loss, along with improvements in multiple cardiovascular risk factors, suggests that liraglutide may offer a novel and clinically valuable approach to disease management for patients with type 2 diabetes. Topics: Blood Glucose; Body Weight; Cardiotonic Agents; Cardiovascular Diseases; Clinical Trials, Phase I as Topic; Clinical Trials, Phase II as Topic; Diabetes Mellitus, Type 2; Disease Management; Drug Therapy, Combination; Gastric Emptying; Glucagon-Like Peptide 1; Glycated Hemoglobin; Humans; Hypoglycemic Agents; Insulin; Insulin-Secreting Cells; Liraglutide; Metformin | 2010 |
Glycaemic control with liraglutide: the phase 3 trial programme.
To review the efficacy and safety of liraglutide from the phase 3 trials, focusing primarily on glycaemic control.. Liraglutide was shown to reduce glycated haemoglobin (HbA(1c) ) levels by up to 1.5% from baseline, significantly more than the comparators sitagliptin (-0.9%), glimepiride (-0.5%), rosiglitazone (-0.4%), insulin glargine (-1.1%) and exenatide (-0.8%). Both fasting plasma glucose (FPG) and postprandial plasma glucose (PPG) levels were shown to be significantly reduced from baseline [up to -2.4 mmol/l (-43.2 mg/dl) and -2.7 mmol/l (-48.6 mg/dl) for FPG and PPG in the liraglutide 1.8 mg group, respectively]. Changes in HbA(1c) , FPG and PPG levels were sustained for the duration of the studies (up to 52 weeks). The glycaemic control offered by liraglutide was not associated with an increased rate of minor hypoglycaemic events compared with comparator treatments, with rates significantly lower than those of glimepiride and exenatide. Major hypoglycaemic events were rare and only occurred in combination with a sulfonylurea. Nausea was the most frequent adverse event, but subsided within the first few weeks.. Liraglutide has been shown to offer effective glycaemic control for patients with type 2 diabetes and is appropriate for use across the conventional continuum of care. Despite the sustained reductions in HbA(1c) , FPG and PPG levels achieved with liraglutide, rates of minor hypoglycaemia were generally low, although the risk increased when combined with a sulfonylurea. Liraglutide is therefore a promising new option for the treatment of type 2 diabetes. Topics: Blood Glucose; Clinical Trials, Phase III as Topic; Diabetes Mellitus, Type 2; Drug Therapy, Combination; Glucagon-Like Peptide 1; Glycated Hemoglobin; Humans; Hypoglycemia; Hypoglycemic Agents; Liraglutide; Nausea | 2010 |
Liraglutide: effects beyond glycaemic control in diabetes treatment.
To review the non-glycaemic effects of liraglutide, including potential improvements in body weight, systolic blood pressure (SBP) and pancreatic beta-cell function.. Liraglutide induced weight loss of around 2-3 kg compared with weight increases of 1-2 kg with active comparators such as insulin glargine, rosiglitazone and glimepiride. Exenatide demonstrated similar weight benefits to liraglutide, but the dipeptidyl peptidase-4 (DPP-4) inhibitors, sitagliptin, saxagliptin and vildagliptin, were weight neutral. Liraglutide was associated with decreases in SBP of 2-7 mmHg, whereas exenatide, vildagliptin and sitagliptin demonstrated SBP reductions of around 2-3 mmHg. Measures of pancreatic beta-cell function were improved with liraglutide vs. placebo, rosiglitazone and exenatide. However, DPP-4 inhibitors appear to have less effect on beta-cell function than glucagon-like peptide-1 (GLP-1) receptor agonists.. In addition to glycaemic control, liraglutide and the other incretin-based therapies offer additional non-glycaemic benefits to varying degrees. The ability of GLP-1 receptor agonists to provide modest, but clinically relevant improvements in body weight and SBP, and to potentially benefit beta-cell function make them an exciting therapeutic option for individuals with diabetes. In contrast, DPP-4 inhibitors are weight neutral and may have lesser benefits on beta-cell function. Topics: Blood Pressure; Body Weight; Diabetes Mellitus, Type 2; Dipeptidyl-Peptidase IV Inhibitors; Glucagon-Like Peptide 1; Humans; Hypoglycemic Agents; Insulin; Insulin-Secreting Cells; Liraglutide; Therapeutic Equivalency | 2010 |
Clinical experience with liraglutide.
To provide insight into clinical experience with liraglutide by reviewing four case studies of patients initiating liraglutide treatment.. Liraglutide treatment was associated with clinically relevant reductions in glycated haemoglobin (HbA(1c.) ) levels. In two of three cases for which HbA(1c) information was available, patients achieved an HbA(1c) of 6.5% at 9-month follow-up and 6.1% at 12-month follow-up. In the third case, the HbA(1c) level was 7.5% at 18-month follow-up. Individuals treated with liraglutide also experienced clinically relevant weight reductions of 4-10%. Other non-glycaemic benefits of liraglutide treatment included reductions in blood pressure. There were no reported incidences of hypoglycaemia. Gastrointestinal adverse side effects were most commonly reported, including nausea, vomiting and dyspepsia; however, symptoms generally subsided during the first month of treatment. In one patient who had prolonged nausea with exenatide over 2 years, a treatment switch to liraglutide resulted in resolution of the nausea symptoms.. Liraglutide treatment was associated with reductions in HbA(1c) levels as well as benefits beyond glycaemic control, such as weight loss and systolic blood pressure reductions. No hypoglycaemic episode was reported. Transient gastrointestinal adverse side effects were most commonly reported. Topics: Blood Pressure; Body Weight; Diabetes Mellitus, Type 2; Drug Substitution; Exenatide; Glucagon-Like Peptide 1; Glycated Hemoglobin; Humans; Hypoglycemic Agents; Liraglutide; Medical Records; Monitoring, Physiologic; Peptides; Venoms; Vomiting | 2010 |
[Glucagon-like peptide 1: a novel therapeutic strategy for Alzheimer's disease].
There is a close correlation between type 2 diabetes mellitus (T2DM) and Alzheimer's disease (AD) in the course of pathophysiological processes. The neuroprotective action of glucagon-like peptide 1 (GLP-1), a latest drug for clinical treatment of T2DM, is being more deeply investigated at present, and a novel therapeutic strategy for AD with GLP-1 has been proposed boldly. This review mainly discussed the correlation of pathogenesis between T2DM and AD, the synthesis and secretion of GLP-1, the distribution and physiological effects of GLP-1 receptor in the brain, and the progresses on the study of GLP-1 in the treatment of AD. Topics: Alzheimer Disease; Amyloid beta-Peptides; Animals; Brain; Diabetes Mellitus, Type 2; Glucagon-Like Peptide 1; Glucagon-Like Peptide-1 Receptor; Humans; Neuroprotective Agents; Receptors, Glucagon | 2010 |
Liraglutide in clinical practice: dosing, safety and efficacy.
This article reviews practical issues that healthcare providers need to consider when implementing therapy with the once-daily glucagon-like peptide-1 (GLP-1) receptor agonist liraglutide.. Liraglutide is administered once daily by subcutaneous injection, independent of meals and at any time of day. To improve gastro-intestinal tolerability, the starting dose is 0.6 mg liraglutide daily. After at least 1 week, the dose should be increased to 1.2 mg. Some patients may benefit from an additional increment to the maximum recommended daily dose of 1.8 mg. Daily blood glucose monitoring is not required, although may be necessary if liraglutide is used with a sulphonylurea (SU). Treatment is contraindicated in patients with known hypersensitivity to liraglutide or an excipient. Liraglutide slows gastric emptying, but does not interact with acetaminophen, oral contraceptives, atorvastatin, griseofulvin, lisinopril or digoxin in a way that necessitates dose adjustments of these agents. The efficacy and safety of liraglutide are not influenced by differences in gender, age or ethnicity and race. Overall, liraglutide is generally well tolerated. Patients can experience gastrointestinal side effects, such as nausea, which diminish over time. As liraglutide increases insulin production in a glucose-dependent manner, the incidence of hypoglycaemia largely depends on the hypoglycaemic risk profile of the selected oral antidiabetic with which it is used. The use of an SU may increase the risk of hypoglycaemia; this risk can be lowered by reducing the SU dose.. Liraglutide is a once-daily treatment option that can be used in adults with type 2 diabetes regardless of gender, age (although therapeutic experience in patients over 75 years of age is limited) and ethnicity or race. Topics: Adult; Contraindications; Diabetes Mellitus, Type 2; Drug Dosage Calculations; Drug Interactions; Drug-Related Side Effects and Adverse Reactions; Glucagon-Like Peptide 1; Glucagon-Like Peptide-1 Receptor; Humans; Hypoglycemia; Hypoglycemic Agents; Injections, Subcutaneous; Liraglutide; Nausea; Receptors, Glucagon; Sulfonylurea Compounds; Treatment Outcome | 2010 |
[Incretin related drugs].
Incretin, GIP and GLP-1, are blood glucose lowering hormones secreted from K cells and L cells, and are rapidly degenerated by DPP-4 within a few minutes. Recently incretin related drugs, GLP-1 analogs and DPP-4 inhibitors are developed. GLP-1 analogs have amino acid substitutions, which make the GLP-1 peptide resistant to degeneration by DPP-4, while DPP-4 inhibitors prevent endogenous GLP-1 to be degenerated by DPP-4. Since they exert blood glucose lowering effect only when blood glucose levels are high, hypoglycemia rarely occurs when administrated without other anti-diabetic drugs. Incretin related drugs are expected to be a new strategy for treating type 2 diabetes. Topics: Diabetes Mellitus, Type 2; Glucagon-Like Peptide 1; Humans; Incretins; Molecular Targeted Therapy | 2010 |
Treatment of diabetes with glucagon-like peptide-1 gene therapy.
Glucagon-like peptide (GLP)-1 receptor agonists are in widespread clinical use for the treatment of diabetes. While effective, these peptides require frequent injections to maintain efficacy. Therefore, alternative delivery methods including gene therapy are currently being evaluated.. Here, we review the biology of GLP-1, evidence supporting the clinical use of the native peptide as well as synthetic GLP-1 receptor agonists, and the rationale for their delivery by gene therapy. We then review progress made in the field of GLP-1 gene therapy for both type 1 and type 2 diabetes.. Efforts to improve the biological half-life of GLP-1 receptor agonists are discussed. We focus on the development of both viral and non-viral gene delivery methods, highlighting vector designs and the strengths and weaknesses of these approaches. We also discuss the utility of targeting regulated GLP-1 production to tissues including the liver, muscle, islet and gut.. GLP-1 is a natural peptide possessing several actions that effectively combat diabetes. Current delivery methods for GLP-1-based drugs are cumbersome and do not recapitulate the normal secretion pattern of the native hormone. Gene therapy offers a useful method for directing long-term production and secretion of the native peptide. Targeted production of GLP-1 using tissue-specific promoters and delivery methods may improve therapeutic efficacy, while also eliminating the burden of frequent injections. Topics: Animals; Diabetes Mellitus, Type 1; Diabetes Mellitus, Type 2; Disease Models, Animal; Genetic Therapy; Glucagon-Like Peptide 1; Glucagon-Like Peptide-1 Receptor; Humans; Receptors, Glucagon; Treatment Outcome | 2010 |
Treatment of type 2 diabetes: New clinical studies and effects of GLP-1 on macrovascular complications.
Various publications in 2009 showed that the treatment of type 2 diabetic (T2D) patients with macrovascular complications is still a controversial subject, whether with regard to the use of glitazones, to the best management strategy for T2D patients with stable coronary artery disease or to the use of incretin mimetic drugs in patients with heart disease. The Rosiglitazone Evaluated for Cardiac Outcomes and Regulation of glycemia in Diabetes study (RECORD) compared cardiovascular morbidity-mortality outcomes in patients taking rosiglitazone in combination with metformin or sulfonylurea versus metformin with sulfonylurea. The results showed that rosiglitazone was not inferior to the metformin-sulfonylurea combination in terms of mortality and cardiovascular hospitalization, but caution must be used when interpreting the results, as the event rate was low. The BARI 2D study (Bypass Angioplasty Revascularization Investigation 2 Diabetes) is a cardiovascular morbidity-mortality trial with the goal of determining the best strategy for blood glucose control and revascularization in T2D patients with stable coronary artery disease. The results of this trial showed that early revascularization is not clearly beneficial, except in a subgroup of patients in whom surgical revascularization is indicated. The use of GLP-1 analogs (Glucagon-Like Peptide-1) in the acute phase of myocardial ischemia in animal models provided promising results. Some clinical studies also suggest an improvement in cardiovascular risk factors with these treatments. Results from morbidity-mortality studies are needed to better assess the long-term efficiency of these new drugs. Topics: Animals; Coronary Artery Disease; Diabetes Mellitus, Type 2; Diabetic Angiopathies; Glucagon-Like Peptide 1; Heart Diseases; Humans; Hypoglycemic Agents; Risk Factors; Rosiglitazone; Thiazolidinediones | 2010 |
Central GLP-1 actions on energy metabolism.
Glucagon-like peptide 1 (GLP-1) is secreted mainly by the intestine in a nutrient-dependent manner and stimulates glucose-induced insulin secretion, inhibits gastric emptying, food intake, and glucagon secretion. All these beneficial effects make GLP-1 as a promising, and currently in the market, drug candidate for the treatment of type 2 diabetes. More recently, it has been also demonstrated that within the central nervous system, GLP-1 also exerts important metabolic actions inhibiting food intake, increasing insulin secretion, and modulating behavioral responses. In this review, we will focus on the metabolic actions and mechanisms of the central GLP-1 system: modulation of energy intake, glucose metabolism, and fatty acid metabolism. Topics: Animals; Central Nervous System; Diabetes Mellitus, Type 2; Eating; Energy Metabolism; Fatty Acids; Glucagon-Like Peptide 1; Glucose; Humans | 2010 |
The role of GLP-1 in neuronal activity and neurodegeneration.
Type 2 diabetes has been identified as a risk factor for Alzheimer's disease (AD). The underlying mechanism behind this unexpected link is most likely linked to the observed desensitization of insulin receptors in the brain. Insulin acts as a growth factor in the brain and supports neuronal repair, dendritic sprouting, and differentiation. Several drugs have been developed to treat type 2 diabetes which re-synthesize insulin receptors and may be of use to prevent neurodegenerative developments in AD. The incretin glucagon-like peptide-1 (GLP-1) is a hormone that facilitates insulin release under high blood sugar conditions. Interestingly, GLP-1 also has very similar growth factor like properties as insulin, and has been shown to protect neurons from toxic effects. In preclinical studies, GLP-1 and longer lasting analogues reduce apoptosis, protect neurons from oxidative stress, induce neurite outgrowth, protect synaptic plasticity and memory formation from the detrimental effects of β-amyloid, and reduce plaque formation and the inflammation response in the brains of mouse models of AD. An advantage of GLP-1 is that it does not affect blood sugar levels in nondiabetic people. Furthermore, recent research has shown that some GLP-1 analogues can cross the blood-brain barrier, including two that are on the market as a treatment for type 2 diabetes. Therefore, GLP-1 analogues show great promise as a novel treatment for AD or other neurodegenerative conditions. Topics: Alzheimer Disease; Animals; Blood-Brain Barrier; Diabetes Mellitus, Type 2; Glucagon-Like Peptide 1; Humans; Nerve Degeneration; Receptor, Insulin | 2010 |
Incretin-based therapy and type 2 diabetes.
This chapter focuses on the incretin hormones, glucagon-like peptide-1 (GLP-1), and glucose-dependent insulinotropic polypeptide (GIP), and their therapeutic potential in treating patients with type 2 diabetes. Type 2 diabetes is characterized by insulin resistance, impaired glucose-induced insulin secretion, and inappropriately regulated glucagon secretion which in combination eventually result in hyperglycemia and in the longer term microvascular and macrovascular diabetic complications. Traditional treatment modalities--even multidrug approaches--for type 2 diabetes are often unsatisfactory at getting patients to glycemic goals as the disease progresses due to a steady, relentless decline in pancreatic beta-cell function. Furthermore, current treatment modalities are often limited by inconvenient dosing regimens, safety, and tolerability issues, the latter including hypoglycemia, body weight gain, edema, and gastrointestinal side effects. Therefore, the actions of GLP-1 and GIP, which include potentiation of meal-induced insulin secretion and trophic effects on the beta-cell, have attracted a lot of interest. GLP-1 also inhibits glucagon secretion and suppresses food intake and appetite. Two new drug classes based on the actions of the incretin hormones have been approved for therapy of type 2 diabetes: injectable long-acting stable analogs of GLP-1, incretin mimetics, and orally available inhibitors of dipeptidyl peptidase 4 (DPP4; the enzyme responsible for the rapid degradation of GLP-1 and GIP), the so-called incretin enhancers. In this chapter, we will describe the physiological effect of the incretin hormones--the incretin effect--in a historical perspective and focus on the two new classes of antidiabetic agents and will outline the scientific basis for the development of incretin mimetics and incretin enhancers, review clinical experience gathered so far, and discuss future expectations for incretin-based therapy. Topics: Animals; Diabetes Mellitus, Type 2; Dipeptidyl Peptidase 4; Gastric Inhibitory Polypeptide; Glucagon-Like Peptide 1; Humans | 2010 |
Defining and achieving treatment success in patients with type 2 diabetes mellitus.
Traditionally, successful treatment of patients with type 2 diabetes mellitus (DM) has been defined strictly by achievement of targeted glycemic control, primarily using a stepped-care approach that begins with changes in lifestyle combined with oral therapy that is slowly intensified as disease progression advances and β-cell function declines. However, stepped care is often adjusted without regard to the mechanism of hyperglycemia or without long-term objectives. A more comprehensive definition of treatment success in patients with type 2 DM should include slowing or stopping disease progression and optimizing the reduction of all risk factors associated with microvascular and macrovascular disease complications. To achieve these broader goals, it is important to diagnose diabetes earlier in the disease course and to consider use of more aggressive combination therapy much earlier with agents that have the potential to slow or halt the progressive β-cell dysfunction and loss characteristic of type 2 DM. A new paradigm for managing patients with type 2 DM should address the concomitant risk factors and morbidities of obesity, hypertension, and dyslipidemia with equal or occasionally even greater aggressiveness than for hyperglycemia. The use of antidiabetes agents that may favorably address cardiovascular risk factors should be considered more strongly in treatment algorithms, although no pharmacological therapy is likely to be ultimately successful without concomitant synergistic lifestyle changes. Newer incretin-based therapies, such as glucagon-like peptide 1 receptor agonists and dipeptidyl peptidase 4 inhibitors, which appear to have a favorable cardiovascular safety profile as well as the mechanistic possibility for a favorable cardiovascular risk impact, are suitable for earlier inclusion as part of combination regimens aimed at achieving comprehensive treatment success in patients with type 2 DM. Topics: Blood Glucose; Diabetes Complications; Diabetes Mellitus, Type 2; Dipeptidyl-Peptidase IV Inhibitors; Dose-Response Relationship, Drug; Female; Glucagon-Like Peptide 1; Humans; Hypoglycemic Agents; Incretins; Male; Risk Assessment; Safety Management; Severity of Illness Index; Total Quality Management; Treatment Outcome; United States | 2010 |
Incorporating incretin-based therapies into clinical practice: differences between glucagon-like Peptide 1 receptor agonists and dipeptidyl peptidase 4 inhibitors.
Type 2 diabetes mellitus (DM) is a prevalent disorder that affects children, adolescents, and adults worldwide. In addition to risks of microvascular disease, patients with type 2 DM often have multiple risk factors of macrovascular disease; for example, approximately 90% of patients with type 2 DM are overweight/obese. Type 2 DM is a complex disease that involves a variety of pathophysiologic abnormalities, including insulin resistance, increased hepatic glucose production, and abnormalities in the secretion of hormones, such as insulin, glucagon, amylin, and incretins. Incretins are gut-derived peptides with a variety of glucoregulatory functions. Incretin dysfunction can be treated with glucagon-like peptide 1 (GLP-1) receptor agonists (eg, exenatide and liraglutide) or inhibitors of dipeptidyl peptidase 4 (DPP-4) (eg, sitagliptin and saxagliptin), the enzyme that degrades GLP-1. The GLP-1 receptor agonists and DPP-4 inhibitors both elevate GLP-1 activity and substantially improve glycemic control. The GLP-1 receptor agonists are more effective in lowering blood glucose and result in substantial weight loss, whereas therapy with DPP-4 inhibitors lowers blood glucose levels to a lesser degree, and they are weight neutral. Treatment with GLP-1 receptor agonists has demonstrated durable glycemic control and improvement in multiple cardiovascular disease risk factors. In addition, unlike insulin or sulfonylureas, treatment with a GLP-1 receptor agonist or a DPP-4 inhibitor has not been associated with substantial hypoglycemia. These factors should be considered when selecting monotherapy or elements of combination therapy for patients with type 2 DM who are overweight/obese, for patients who have experienced hypoglycemia with other agents, and when achieving glycemic targets is difficult. Topics: Adolescent; Adult; Blood Glucose; Child; Diabetes Complications; Diabetes Mellitus, Type 2; Dipeptidyl-Peptidase IV Inhibitors; Dose-Response Relationship, Drug; Drug Administration Schedule; Drug Therapy, Combination; Female; Follow-Up Studies; Glucagon-Like Peptide 1; Humans; Hyperglycemia; Hypoglycemia; Hypoglycemic Agents; Incretins; Male; Randomized Controlled Trials as Topic; Risk Assessment; Severity of Illness Index; Treatment Outcome; Young Adult | 2010 |
A physiologic and pharmacological basis for implementation of incretin hormones in the treatment of type 2 diabetes mellitus.
Progressive deterioration of β-cell function is a hallmark of type 2 diabetes mellitus (DM). Together with increasing insulin resistance in peripheral tissues (in both the liver and the skeletal muscle), the inability of pancreatic insulin secretion to manage fasting and postprandial glucose levels results in hyperglycemia. Currently available oral antidiabetes agents improve glycemic parameters, but no single drug addresses the numerous pathophysiologic defects known to contribute to hyperglycemia in patients with type 2 DM. Dysregulation in the incretin system is another component of the pathophysiologic processes that lead to DM. Agents used to correct defects in the incretin system, such as glucagon-like peptide 1 receptor agonists and dipeptidyl peptidase 4 inhibitors, offer the potential to restore glucose-dependent insulin secretion and improve β-cell function. Glucagon-like peptide 1 receptor agonists also promote weight loss and provide beneficial effects on cardiovascular risk factors. A new approach that promotes the selection of pharmacotherapy for the treatment of patients with DM, with the goal of slowing or reversing the natural history of the disease, may be in order. Clinicians can select agents to address specific pathophysiologic defects to improve glycemia, with the hope of preventing the development of complications. Topics: Administration, Oral; Diabetes Mellitus, Type 2; Dose-Response Relationship, Drug; Drug Administration Schedule; Female; Glucagon-Like Peptide 1; Humans; Hypoglycemic Agents; Incretins; Injections, Subcutaneous; Insulin; Insulin Resistance; Islets of Langerhans; Male; Risk Assessment; Treatment Outcome | 2010 |
Liraglutide in the management of type 2 diabetes.
The pathophysiology of type 2 diabetes has been attributed to the classic triad of decreased insulin secretion, increased insulin resistance, and elevated hepatic glucose production. Research has shown additional mechanisms, including incretin deficiency or resistance in the gastrointestinal tract. Liraglutide is a modified form of human glucagon-like peptide-1. Liraglutide was obtained by substitution of lysine 34 for arginine near the NH2 terminus, and by addition of a C16 fatty acid at the ɛ-amino group of lysine (at position 26) using a γ-glutamic acid spacer. Liraglutide has demonstrated glucose-dependent insulin secretion, improvements in β-cell function, deceleration of gastric emptying, and promotion of early satiety leading to weight loss. Liraglutide has the potential to acquire an important role, not only in the treatment of type 2 diabetes, but also in preservation of β-cell function, weight loss, and prevention of chronic diabetic complications. Topics: Animals; Diabetes Mellitus, Type 2; Glucagon-Like Peptide 1; Humans; Hypoglycemic Agents; Insulin; Insulin Secretion; Insulin-Secreting Cells; Liraglutide; Weight Loss | 2010 |
The incretin system in the management of type 2 diabetes mellitus.
Topics: Blood Glucose; Diabetes Mellitus, Type 2; Dipeptidyl-Peptidase IV Inhibitors; Dipeptidyl-Peptidases and Tripeptidyl-Peptidases; Glucagon-Like Peptide 1; Humans; Incretins; Liraglutide | 2010 |
Comparing incretin-based therapies. Evaluating GLP-1 agonists and DPP-4 inhibitors for type 2 diabetes mellitus.
Topics: Blood Glucose; Clinical Trials as Topic; Diabetes Mellitus, Type 2; Dipeptidyl-Peptidase IV Inhibitors; Glucagon-Like Peptide 1; Humans; Incretins; Nurse Practitioners; Physician Assistants | 2010 |
[Beta-cell function in the foreground. GLP-1 based therapy of type 2 diabetes].
Topics: Biological Availability; Blood Glucose; Delayed-Action Preparations; Diabetes Mellitus, Type 2; Dipeptidyl Peptidase 4; Drug Administration Schedule; Drug Therapy, Combination; Exenatide; Glucagon-Like Peptide 1; Half-Life; Humans; Hypoglycemic Agents; Injections, Subcutaneous; Insulin-Secreting Cells; Liraglutide; Metabolic Clearance Rate; Peptides; Venoms | 2010 |
The incretin system and its role in type 2 diabetes mellitus.
The incretin hormones are released during meals from gut endocrine cells. They potentiate glucose-induced insulin secretion and may be responsible for up to 70% of postprandial insulin secretion. The incretin hormones include glucagon-like peptide-1 (GLP-1) and glucose-dependent insulinotropic polypeptide (GIP), both of which may also promote proliferation/neogenesis of beta cells and prevent their decay (apoptosis). Both hormones contribute to insulin secretion from the beginning of a meal and their effects are progressively amplified as plasma glucose concentrations rise. The current interest in the incretin hormones is due to the fact that the incretin effect is severely reduced or absent in patients with type 2 diabetes mellitus (T2DM). In addition, there is hyperglucagonaemia, which is not suppressible by glucose. In such patients, the secretion of GIP is near normal, but its effect on insulin secretion, particularly the late phase, is severely impaired. The loss of GIP action is probably a consequence of diabetes, since it is also observed in patients with diabetes secondary to chronic pancreatitis, in whom the incretin effect is also lost. GLP-1 secretion, on the other hand, is also impaired, but its insulinotropic and glucagon-suppressive actions are preserved, although the potency of GLP-1 in this respect is decreased compared to healthy subjects. However, in supraphysiological doses, GLP-1 administration may completely normalize beta as well as alpha cell sensitivity to glucose. The impaired action of GLP-1 and GIP in T2DM may be at least partly restored by improved glycaemic control, as shown in studies involving 4 weeks of intensive insulin therapy. The reduced incretin effect is believed to contribute to impaired regulation of insulin and glucagon secretion in T2DM, and, in support of this, exogenous GLP-1 administration may restore blood glucose regulation to near normal levels. Thus, the pathogenesis of T2DM seems to involve a dysfunction of both incretins. Enhancement of incretin action may therefore represent a therapeutic solution. Clinical strategies therefore include the development of metabolically stable activators of the GLP-1 receptor; and inhibition of DPP-4, the enzyme that destroys native GLP-1 almost immediately. Orally active DPP-4 inhibitors and the metabolically stable activators, exenatide (Byetta), are now on the market, and numerous clinical studies have shown that both principles are associated with durable antidiabetic Topics: Animals; Diabetes Mellitus, Type 2; Dipeptidyl-Peptidase IV Inhibitors; Glucagon-Like Peptide 1; Glucagon-Like Peptide-1 Receptor; Humans; Incretins; Receptors, Glucagon | 2009 |
Do Incretins play a role in the remission of type 2 diabetes after gastric bypass surgery: What are the evidence?
Gastric bypass surgery (GBP), in addition to weight loss, results in dramatic remission of type 2 diabetes (T2DM). The mechanisms by which this remission occurs are unclear. Besides weight loss and caloric restriction, the changes in gut hormones that occur after GBP are increasingly gaining recognition as key players in glucose control. Incretins are gut peptides that stimulate insulin secretion postprandially; the levels of these hormones, particularly glucagon-like peptide-1, increase after GBP in response to nutrient stimulation. Whether these changes are causal to changes in glucose homeostasis remain to be determined. The purpose of this review is to assess the evidence on incretin changes and T2DM remission after GBP, and the possible mechanisms by which these changes occur. Our goals are to provide a thorough update on this field of research so that recommendations for future research and criteria for bariatric surgery can be evaluated. Topics: Animals; Diabetes Mellitus, Type 2; Evidence-Based Medicine; Gastric Bypass; Gastric Emptying; Gastric Inhibitory Polypeptide; Ghrelin; Glucagon-Like Peptide 1; Gluconeogenesis; Glucose; Homeostasis; Humans; Incretins; Intestine, Small; Leptin; Liver; Obesity, Morbid; Peptide YY; Randomized Controlled Trials as Topic; Remission Induction; Weight Loss | 2009 |
Incretin mimetics and DPP-4 inhibitors: new approach to treatment of type 2 diabetes mellitus.
Type 2 diabetes constitutes the main bulk (85-90%) of diabetic population. It is a chronic metabolic disorder with progressive ?beta-cell dysfunction, impaired insulin actions and various other abnormalities. Insulin response of beta-cell is more after oral glucose or following meal than intravenous infusion of glucose. Gut related peptides, the incretin hormones released after meal following activation of the enteroinsular axis plays an important role in glucose homeostasis by pancreatic and extrapancreatic glucoregulatory effects and helps in preservation of beta-cell function. In type 2 diabetes, there is progressive decline of these incretins level, glucagons like peptide-1 (GLP-1) and glucose dependent insulinotropic polypeptide (GIP) with loss of beta-cell mass, beta-cell function and glycemic deterioration. These peptides are rapidly degraded by endogenous proteases, dipeptidyl peptides-4 (DPP-4) giving a very short half life of 2-3 minutes. Currently available anti-diabetic drugs do not address these arms of glucoregulatory dysfunction of type 2 diabetes. Modern therapeutic strategy should be targeted at preservation of beta-cell mass and function by exploiting the incretin hormones and enteroinsular axis. DPP-4 resistant incretin analogues/mimetics (e.g. exenatide, liraglutide) that have been developed by modifications/ substitutions in the polypeptide chain may be an effective alternative of the existing therapy of type-2 DM. DPP-4 inhibitors (e.g. sitagliptin, vindagliptin) prevent the degradation of endogenous GLP-1 and GIP, thereby potentiate their actions and help in glycemic control. Distinctive features of incretin mimetics are: their action is glucose dependent, do not produce hypoglycemia, help in preservation of beta-cell mass and function, help in weight reduction. DPP-4 inhibitors are weight neutral. Ongoing studies will reveal newer avenues and long term outcome of these molecules. Topics: Adamantane; Diabetes Mellitus, Type 2; Dipeptidyl-Peptidase IV Inhibitors; Exenatide; Gastric Inhibitory Polypeptide; Glucagon-Like Peptide 1; Humans; Hypoglycemic Agents; Incretins; Liraglutide; Nitriles; Peptides; Pyrazines; Pyrrolidines; Sitagliptin Phosphate; Triazoles; Venoms; Vildagliptin | 2009 |
Medicinal chemistry approaches to the inhibition of dipeptidyl peptidase-4 for the treatment of type 2 diabetes.
Emerging as an epidemic of the 21st century type 2 diabetes has become a major health problem throughout the globe. The number of deaths attributable to diabetes reflects the insufficient glycemic control achieved with the treatments used in recent past. DPP-4 inhibitors have been investigated as a new therapy with novel mechanisms of action and improved tolerability. DPP-4, a protease that specifically cleaves dipeptides from proteins and oligopeptides after a penultimate N-terminal proline or alanine, is involved in the degradation of a number of neuropeptides, peptide hormones and cytokines, including the incretins GLP-1 and GIP. As soon as released from the gut in response to food intake, GLP-1 and GIP exert a potent glucose-dependent insulinotropic action, thereby playing a key role in the maintenance of post-meal glycemic control. Consequently, inhibiting DPP-4 prolongs the action of GLP-1 and GIP, which in turn improves glucose homeostasis with a low risk of hypoglycemia and potential for disease modification. Indeed, clinical trials involving diabetic patients have shown improved glucose control by administering DPP-4 inhibitors, thus demonstrating the benefit of this promising new class of antidiabetics. Intense research activities in this area have resulted in the launch of sitagliptin and vildagliptin (in Europe only) and the advancement of a few others into preregistration/phase 3, for example, saxagliptin, alogliptin and ABT-279. Achieving desired selectivity for DPP-4 over other related peptidases such as DPP-8 and DPP-9 (inhibition of which was linked to toxicity in animal studies) and long-acting potential for maximal efficacy (particularly in more severe diabetic patients) were the major challenges. Whether these goals are achieved with the present series of inhibitors in the advanced stages of clinical development is yet to be confirmed. Nevertheless, treatment of this metabolic disorder especially in the early stages of the disease via DPP-4 inhibition has been recognized as a validated principle and a large number of inhibitors are presently in various stage of pre-clinical/clinical development. Sitagliptin is a new weapon in the arsenal of oral antihyperglycemic agents. This review will focus on the journey of drug discovery of DPP-4 inhibitors for oral delivery covering a brief scientific background and medicinal chemistry approaches along with the status of advanced clinical candidates. Topics: Chemistry, Pharmaceutical; Diabetes Mellitus, Type 2; Dipeptidyl Peptidase 4; Dipeptidyl-Peptidase IV Inhibitors; Enzyme Inhibitors; Glucagon; Glucagon-Like Peptide 1; Glutaminase; Humans; Hypoglycemic Agents; Insulin; Intracellular Signaling Peptides and Proteins | 2009 |
Functional pancreatic beta-cell mass: involvement in type 2 diabetes and therapeutic intervention.
In the adult, the pancreatic beta-cell mass adapts insulin secretion to meet long-term changes in insulin demand and, in particular, in the presence of insulin resistance that is either physiological, such as pregnancy, or pathophysiological, such as obesity. The failure of beta cells to compensate for insulin resistance is a major component of impaired glucose homeostasis and overt diabetes. This defect is clearly the consequence of a decline of insulin response to glucose due to functional beta-cell deficiency. It is also the consequence of an inability of the endocrine pancreas to adapt the beta-cell mass to insulin demand (pancreas plasticity), which eventually leads to a decrease in functional beta-cell mass. This idea has resulted in considerable attention being paid to the development of new therapeutic strategies aiming to preserve and/or regenerate functional beta-cell mass. The latter is governed by a constant balance between beta-cell growth (replication from pre-existing beta cells and neogenesis from precursor cells) and beta-cell death (mainly apoptosis). Disruption of this balance may lead to rapid and marked changes in beta-cell mass. Glucagon-like peptide-1 (GLP-1), an incretin, enhances beta-cell survival (by activating beta-cell proliferation and differentiation, and inhibiting beta-cell apoptosis), thus contributing to the long-term regulation of insulin secretion by maintaining a functional beta-cell mass. The development of drugs regulating this parameter will be the major challenge of the next few years in the management of type 2 diabetes. Topics: Adaptation, Physiological; Diabetes Mellitus, Type 2; Dipeptidyl Peptidase 4; Dipeptidyl-Peptidase IV Inhibitors; Glucagon-Like Peptide 1; Humans; Incretins; Insulin Resistance; Insulin-Secreting Cells | 2009 |
DPP4 inhibitors: from sitagliptin monotherapy to the new alogliptin-pioglitazone combination therapy.
Diabetes mellitus (DM) is currently considered to be an epidemic disease. A safe and effective treatment has long been sought by scientists. Incretin mimetics and dipeptidyl peptidase-4 (DPP4) inhibitors represent a new class of agents that have recently been included as antidiabetic drugs. Although only a limited number of studies exist regarding the treatment of DM based on the incretin effect, DPP4 inhibitors have so far proved to be safe and effective, both when administered alone or in combination with other antidiabetic medication. This review focuses on incretin-effect physiology, as well as the DPP4 inhibitors, from sitagliptin to the new alogliptin-pioglitazone combination agent, given as monotherapy and in combination with other antidiabetic agents. Topics: Adamantane; Animals; Clinical Trials as Topic; Diabetes Mellitus, Type 2; Dipeptides; Dipeptidyl Peptidase 4; Dipeptidyl-Peptidase IV Inhibitors; Drug Therapy, Combination; Gastric Inhibitory Polypeptide; Glucagon-Like Peptide 1; Humans; Hypoglycemic Agents; Incretins; Pioglitazone; Piperidines; Pyrazines; Sitagliptin Phosphate; Thiazolidinediones; Triazoles; Uracil | 2009 |
Recent advances in antidiabetic drug therapies targeting the enteroinsular axis.
The enteroinsular axis (EIA) constitutes a physiological signalling system whereby intestinal endocrine cells secrete incretin hormones following feeding that potentiate insulin secretion and contribute to the regulation of blood glucose homeostasis. The two key hormones responsible are named glucagon-like peptide-1 (GLP-1) and glucose-dependent insulinotropic polypeptide (GIP). Recent years have witnessed sustained development of antidiabetic therapies that exploit the EIA. Current clinical compounds divide neatly into two classes. One concerns analogues or mimetics of GLP-1, such as exenatide (Byetta) or liraglutide (NN2211). The other group comprises the gliptins (e.g. sitagliptin and vildagliptin) which boost endogenous incretin activity by inhibiting the enzyme dipeptidyl peptidase 4 (DPP 4) that degrades both GLP-1 and GIP. Ongoing research indicates that further incretin and gliptin compounds will become available for clinical use in the near future, offering comparable or improved efficacy. For incretin analogues there is the prospect of prolonged duration of action and alternative routes of administration. This review focuses on recent advances in pre-clinical research and their translation into clinical studies to provide future therapies for type 2 diabetes targeting the EIA. Topics: Animals; Clinical Trials as Topic; Diabetes Mellitus, Type 2; Dipeptidyl Peptidase 4; Dipeptidyl-Peptidase IV Inhibitors; Drug Delivery Systems; Drug Evaluation, Preclinical; Gastric Inhibitory Polypeptide; Glucagon-Like Peptide 1; Humans; Hypoglycemic Agents; Incretins; Signal Transduction | 2009 |
Incretin-based therapy of type 2 diabetes mellitus.
This review article focuses on the therapeutic potential of the incretin hormones, glucagon-like peptide-1 (GLP-1) and glucose-dependent insulinotropic polypeptide (GIP), in treating type 2 diabetes mellitus (T2DM). T2DM is characterized by insulin resistance, impaired glucose-induced insulin secretion and inappropriately regulated glucagon secretion which in combination eventually result in hyperglycemia and in the longer term microvascular and macrovascular diabetic complications. Traditional treatment modalities--even multidrug approaches--for T2DM are often unsatisfactory at getting patients to glycemic goals as the disease progresses due to a steady, relentless decline in pancreatic beta-cell function. Furthermore, current treatment modalities are often limited by inconvenient dosing regimens, safety and tolerability issues, the latter including hypoglycemia, body weight gain, edema and gastrointestinal side effects. Therefore, the actions of GLP-1 and GIP, which include potentation of meal-induced insulin secretion and trophic effects on the beta-cell, have attracted a lot of interest. GLP-1 also inhibits glucagon secretion, and suppresses food intake and appetite. Two new drug classes based on the actions of the incretin hormones have recently been approved for therapy of T2DM; injectable long-acting stable analogues of GLP-1, incretin mimetics, and orally available inhibitors of dipeptidyl peptidase 4 (DPP4; the enzyme responsible for the rapid degradation of GLP-1 and GIP), the so-called incretin enhancers. This review article focuses on these two new classes of antidiabetic agents and will outline the scientific basis for the development of incretin mimetics and incretin enhancers, review clinical experience gathered so far and discuss future expectations for incretin-based therapy. Topics: Animals; Diabetes Mellitus, Type 2; Dipeptidyl-Peptidase IV Inhibitors; Drug Design; Gastric Inhibitory Polypeptide; Glucagon-Like Peptide 1; Humans; Hypoglycemic Agents; Incretins; Molecular Mimicry | 2009 |
Drug evaluation: vildagliptin-metformin single-tablet combination.
The single-tablet combination of vildagliptin and metformin addresses key defects of type 2 diabetes for improved glycemic control. By inhibiting the dipeptidyl peptidase-4 (DPP-4) enzyme, vildagliptin raises the levels of the active incretin hormones, glucagon-like peptide 1 and glucose-dependent insulinotropic peptide. This leads to increased synthesis and release of insulin from the pancreatic beta cells and decreased release of glucagon from the pancreatic alpha cells. The combination tablet also contains metformin, which addresses insulin resistance. The complementary mechanisms of action of the two agents in combination have been shown to provide additive and sustained reductions in hemoglobin A(1c) compared with metformin monotherapy. In active-controlled trials, the vildagliptin-metformin combination has been shown to produce equivalent reductions in hemoglobin A(1c) to pioglitazone-metformin and glimepiride-metformin combinations, without significant risk of hypoglycemia and without causing weight gain. In clinical trials, the overall incidence of any adverse event was similar in patients randomized to vildagliptin plus metformin and placebo plus metformin. Available data support the use of vildagliptin in combination with metformin as a promising second-line treatment for the management of type 2 diabetes and this is reflected in the latest UK National Institute for Health and Clinical Excellence draft guideline for consultation on new agents for blood glucose control in type 2 diabetes. Topics: Adamantane; Body Weight; Diabetes Mellitus, Type 2; Dipeptidyl-Peptidase IV Inhibitors; Drug Combinations; Gastric Inhibitory Polypeptide; Glucagon-Like Peptide 1; Glycated Hemoglobin; Humans; Hypoglycemic Agents; Incretins; Insulin Resistance; Lipids; Metformin; Nitriles; Practice Guidelines as Topic; Pyrrolidines; Safety; Treatment Outcome; Vildagliptin | 2009 |
Glucagon-like peptide-1 receptor agonists in type 2 diabetes: a meta-analysis of randomized clinical trials.
The role of glucagon-like peptide-1 (GLP-1) receptor agonists in the treatment of type 2 diabetes is debated; many recent trials, which were not included in previous meta-analyses, could add relevant information.. All available randomized controlled trials (RCTs), either published or unpublished, performed in type 2 diabetic patients with GLP-1 receptor agonists (exenatide and liraglutide), with a duration>12 weeks were meta-analysed for HbA1c, body mass index, hypoglycaemia and other adverse events.. A total of 21 RCTs (six of which unpublished), enrolling 5429 and 3053 patients (with GLP-1 receptor agonists and active comparator or placebo respectively), was retrieved and included in the analysis. GLP-1 receptor agonists determine a significant improvement of HbA1c in comparison with placebo (-1.0 (-1.1, -0.8), P<0.001), with a low risk of hypoglycaemia. There is no evidence of increased cardiovascular risk with the use of GLP-1 receptor agonists. GLP-1 receptor agonists, which induce weight loss, are associated with gastrointestinal side effects. GLP-1 receptor agonists are effective in reducing HbA1c and postprandial glucose. In patients failing to sulphonylureas and/or metformin, GLP-1 receptor agonists are similarly effective as insulin. Available data suggest that the efficacy and tolerability of the novel agent, liraglutide, which is adequate for once-a-day administration, are comparable with those of exenatide bis in die. Topics: Body Mass Index; Diabetes Mellitus, Type 2; Glucagon-Like Peptide 1; Glucagon-Like Peptide-1 Receptor; Humans; Hypoglycemic Agents; Insulin; Liraglutide; Metformin; Placebos; Randomized Controlled Trials as Topic; Receptors, Glucagon; Sulfonylurea Compounds | 2009 |
Saxagliptin: a new DPP-4 inhibitor for the treatment of type 2 diabetes mellitus.
Type 2 diabetes mellitus (T2DM) is a global epidemic with increasing impact on individuals and healthcare providers. Available treatments (such as metformin, sulfonylureas, glitazones, and insulin) have proven unsatisfactory in producing a long-lasting impact on glycemic control. In addition, most of these treatments have undesirable side effects such as weight gain and hypoglycemia. As a result, exploring new treatment targets and new therapies is mandatory in order to treat this condition. The incretin pathway, in particular glucagon-like peptide (GLP-1), plays an important pathological role in the development of T2DM, and treatments targeting the incretin system have recently become available. These can mainly be divided into two broad categories; GLP-1 agonists/analogs (exenatide, liraglutide), and dipeptidyl peptidase-4 (DPP-4; the enzyme responsible for rapid inactivation of incretins) inhibitors (sitagliptin, vildagliptin). Saxagliptin is a novel DPP-4 inhibitor that has recently completed phase 3 studies. Saxagliptin is a potent and specific inhibitor of DPP-4 (in comparison with other dipeptidyl peptidase enzymes) that is given once daily. Current data suggest that saxagliptin as monotherapy or in combination with metformin, glyburide, or a glitazone results in significant reductions in fasting and postprandial plasma glucose and hemoglobin A(1c) (HbA(1c)). Saxagliptin is well tolerated and does not increase hypoglycemia compared with the placebo, and is probably weight neutral. Saxagliptin will be a new effective drug in the currently available variety of antidiabetic medications for patients with T2DM. Topics: Adamantane; Age Factors; Diabetes Mellitus, Type 2; Dipeptides; Dipeptidyl-Peptidase IV Inhibitors; Drug Interactions; Drug Therapy, Combination; Glucagon-Like Peptide 1; Humans; Hypoglycemic Agents; Incretins; Randomized Controlled Trials as Topic; Sex Factors; Time Factors | 2009 |
Liraglutide: a new treatment for type 2 diabetes.
Liraglutide is a novel glucagon-like peptide-1 (GLP-1) receptor agonist with 97% amino acid sequence identity to native GLP-1. An amino acid substitution and fatty acid side chain enable a more protracted pharmacokinetic profile of over 24 hours. These modifications make liraglutide suitable for once-daily dosing. Liraglutide use exploits the incretin effect to glucose-dependently stimulate insulin secretion. The LEAD (Liraglutide Effect and Action Diabetes) program evaluated the safety and efficacy of liraglutide and demonstrated an improved level of glycemic control relative to currently used oral antidiabetic drugs, including other GLP-1-based therapies. In these trials, liraglutide was shown to enable many patients to achieve hemoglobin A1c (HbA1c) targets and to improve several morbidities commonly associated with type 2 diabetes; liraglutide induced weight loss, reduced systolic blood pressure and improved beta-cell function. Liraglutide was well tolerated, although an increased incidence of mild nausea was observed. Since liraglutide mimics the glucose-sensitive action of native GLP-1, it does not induce hypoglycemia. Liraglutide offers an interesting alternative therapy to control blood glucose levels in patients with type 2 diabetes, who commonly present with hypertension and overweight. It is expected to be approved by the U.S. Food and Drug Administration and the European Medicines Agency in Europe for use in 2009. Topics: Animals; Blood Glucose; Clinical Trials as Topic; Diabetes Mellitus, Type 2; Glucagon-Like Peptide 1; Glucagon-Like Peptide-1 Receptor; Humans; Hypoglycemic Agents; Injections, Subcutaneous; Liraglutide; Receptors, Glucagon | 2009 |
Endocrine mechanisms mediating remission of diabetes after gastric bypass surgery.
Bariatric surgery is currently the most effective method to promote major, sustained weight loss. Roux-en-Y gastric bypass (RYGB), the most commonly performed bariatric operation, ameliorates virtually all obesity-related comorbid conditions, the most impressive being a dramatic resolution of type 2 diabetes mellitus (T2DM). After RYGB, 84% of patients with T2DM experience complete remission of this disease, and virtually all have improved glycemic control. Increasing evidence indicates that the impact of RYGB on T2DM cannot be explained by the effects of weight loss and reduced energy intake alone. Weight-independent antidiabetic actions of RYGB are apparent because of the very rapid resolution of T2DM (before weight loss occurs), the greater improvement of glucose homeostasis after RYGB than after an equivalent weight loss from other means, and the occasional development of very late-onset, pancreatic beta-cell hyperfunction. Several mechanisms probably mediate the direct antidiabetic impact of RYGB, including enhanced nutrient stimulation of L-cell peptides (for example, GLP-1) from the lower intestine, intriguing but still uncharacterized phenomena related to exclusion of the upper intestine from contact with ingested nutrients, compromised ghrelin secretion, and very probably other effects that have yet to be discovered. Research designed to prioritize these mechanisms and identify potential additional mechanisms promises to help optimize surgical design and might also reveal novel pharmaceutical targets for diabetes treatment. Topics: Animals; Blood Glucose; Caloric Restriction; Diabetes Mellitus, Type 2; Gastric Bypass; Ghrelin; Glucagon-Like Peptide 1; Glucose; Glycated Hemoglobin; Homeostasis; Humans; Hyperinsulinism; Hypoglycemia; Insulin; Intestinal Absorption; Obesity; Rats; Remission Induction; Treatment Outcome; Weight Loss | 2009 |
The scientific evidence: vildagliptin and the benefits of islet enhancement.
Vildagliptin is an oral incretin enhancer that acts to increase active levels of the incretin hormone glucagon-like peptide-1 (GLP-1) by inhibiting the dipeptidyl peptidase-4 enzyme responsible for the rapid deactivation of GLP-1 in vivo. This activity results in improved glucose-dependent functioning of pancreatic islet beta and alpha cells, addressing two central deficits in type 2 diabetes mellitus (T2DM). Vildagliptin treatment improves beta-cell sensitivity to glucose, producing increased insulin secretory rate relative to glucose in both postprandial and fasting states. Improved alpha-cell function is shown as restoration of appropriate glucose-related suppression of glucagon and, therefore, reduced endogenous glucose production during both postprandial and fasting periods. There is evidence that long-term vildagliptin treatment may slow underlying deterioration of beta-cell function in T2DM. There is also a potential synergistic effect of vildagliptin and metformin in increasing active GLP-1 levels, and this activity may contribute to the long-term improvements in beta-cell function observed in patients with T2DM who have vildagliptin added to ongoing metformin therapy. Vildagliptin treatment has also been associated with beneficial extrapancreatic effects, including improved peripheral insulin sensitivity and improved postprandial triglyceride-rich lipoprotein metabolism. Improvement of beta- and alpha-cell function through incretin enhancement with vildagliptin results in more physiologic meal-related and fasting glycaemia profiles. Topics: Adamantane; Diabetes Mellitus, Type 2; Dipeptidyl-Peptidase IV Inhibitors; Drug Therapy, Combination; Evidence-Based Medicine; Glucagon-Like Peptide 1; Humans; Hypoglycemic Agents; Islets of Langerhans; Metformin; Nitriles; Pyrrolidines; Vildagliptin | 2009 |
[The value of incretin based therapies].
Topics: Adamantane; Animals; Diabetes Mellitus, Type 2; Dipeptidyl-Peptidase IV Inhibitors; Exenatide; Glucagon-Like Peptide 1; Glucagon-Like Peptide-1 Receptor; Humans; Hypoglycemic Agents; Incretins; Insulin-Secreting Cells; Nitriles; Peptides; Pyrazines; Pyrrolidines; Receptors, Glucagon; Sitagliptin Phosphate; Triazoles; Venoms; Vildagliptin | 2009 |
Targeting the incretin system in type 2 diabetes mellitus.
The incretins have emerged as key targets in the modern treatment of type 2 diabetes mellitus. Understanding the physiology of the incretins is essential to the physician's ability to appropriately use emerging pharmacotherapies that target this system. This review describes incretin physiology and discusses recent trials of drugs that modulate this system in the treatment of type 2 diabetes. A MEDLINE search using the terms "GLP-1" (ie, glucagon-like peptide 1), "incretins," "exenatide," and "DPP-IV inhibitors" (ie, dipeptidyl peptidase IV inhibitors) was performed, and pertinent articles from the past 10 years were reviewed. Articles describing incretin physiology and clinical trials with exenatide and dipeptidyl peptidase IV inhibitors were identified and discussed. As the articles show, new medications manipulating the incretin system are an important part of treating type 2 diabetes. The cost of these drugs and their potential side effects in comparison with existing agents must be considered when they are being selected as part of a treatment regimen. However, the evidence to date offers much promise and enthusiasm. Topics: Clinical Trials as Topic; Diabetes Mellitus, Type 2; Drug Therapy, Combination; Exenatide; Glucagon-Like Peptide 1; Humans; Hypoglycemic Agents; Incretins; Insulin; Peptides; Receptors, Glucagon; Treatment Outcome; Venoms | 2009 |
Inhibition of dipeptidyl peptidase 4 by BI-1356, a new drug for the treatment of beta-cell failure in type 2 diabetes.
BI 1356, a xanthine-based DPP-4 inhibitor, has reached Phase III trials. The compound efficiently inhibits dipeptidyl peptidase 4 (DPP-4) in vitro and in vivo. In vivo GLP-1 levels increase to levels at or above the levels of other DPP-4 inhibitors. Preclinical trials suggest a once-daily administration of 5 mg to be efficient, long-lasting and without known side effects. Topics: Animals; Clinical Trials as Topic; Diabetes Mellitus, Type 2; Dipeptidyl Peptidase 4; Dipeptidyl-Peptidase IV Inhibitors; Drugs, Investigational; Glucagon-Like Peptide 1; Humans; Insulin-Secreting Cells; Linagliptin; Molecular Structure; Purines; Quinazolines | 2009 |
Potential of liraglutide in the treatment of patients with type 2 diabetes.
Liraglutide is a long-acting analog of GLP-1, being developed by Novo Nordisk and currently undergoing regulatory review for the treatment of type 2 diabetes. Upon injection, liraglutide binds non-covalently to albumin, giving it a pharmacokinetic profile suitable for once-daily administration. In clinical trials of up to 1 year duration, liraglutide has been demonstrated to have beneficial effects on islet cell function, leading to improvements in glycemic control. Both fasting and postprandial glucose concentrations are lowered, and are associated with lasting reductions in HbA1c levels. Liraglutide is effective as monotherapy and in combination therapy with oral antidiabetic drugs, and reduces HbA1c by up to approximately 1.5% from baseline (8.2%-8.4%). Because of the glucose-dependency of its action, there is a low incidence of hypoglycemia. Liraglutide is associated with body weight loss, and reductions in systolic blood pressure have been observed throughout the clinical trials. The most common adverse events reported with liraglutide are gastrointestinal (nausea, vomiting and diarrhea). These tend to be most pronounced during the initial period of therapy and decline with time. Further clinical experience with liraglutide will reveal its long-term durability, safety and efficacy. Topics: Amino Acid Sequence; Blood Glucose; Diabetes Mellitus, Type 2; Drug Administration Schedule; Drug Therapy, Combination; Glucagon-Like Peptide 1; Glycated Hemoglobin; Humans; Hypoglycemic Agents; Injections, Subcutaneous; Liraglutide; Molecular Sequence Data; Time Factors; Treatment Outcome | 2009 |
Progress in the oral treatment of type 2 diabetes: update on DPP-IV inhibitors.
Glucagon-like peptide-1 (GLP-1) is a gut hormone that plays an important role in regulating glucose homeostasis by both its pancreatic and extrapancreatic activity. Defects of GLP-1 characterize type 2 diabetes as a primary or perhaps consequent phenomenon, resulting in inappropriately low insulin secretion after oral ingestion of nutrients. The discovery that cleavage by the ubiquitous enzyme dipeptidyl peptidase-IV (DPP-IV) is the primary route of GLP-1 metabolism formed the rationale behind the proposal to prevent degradation of endogenously released GLP-1 by DPP-IV inhibition as a novel approach to the management of type 2 diabetes. Enhanced insulin secretion as well as delayed gastric emptying, reduced glucagon secretion, and inhibited apoptosis of beta cells resulting from blockade of incretin degradation, have been proposed as the major actions of DPP-IV inhibitors as antidiabetic agents. Clinical studies to date indicate that DPP-IV inhibitors effectively ameliorate islet dysfunction and improve glucose control in patients with type 2 diabetes. They appear to have excellent therapeutic effectiveness as monotherapy in patients inadequately controlled with diet and exercise and as add-on therapy in combination with metformin, thiazolidinediones, and insulin. Their pharmacokinetic and pharmacodynamic profiles support once-daily dosing, with relatively few adverse effects. Topics: Administration, Oral; Clinical Trials as Topic; Diabetes Mellitus, Type 2; Dipeptidyl-Peptidase IV Inhibitors; Glucagon-Like Peptide 1; Glucose; Humans; Incretins | 2009 |
Saxagliptin: a new dipeptidyl peptidase-4 inhibitor for the treatment of type 2 diabetes.
Saxagliptin is a potent and selective reversible inhibitor of dipeptidyl peptidase-4, which is being developed for the treatment of type 2 diabetes. It is absorbed rapidly after oral administration and has a pharmacokinetic profile compatible with once daily dosing. Saxagliptin is metabolized in vivo to form an active metabolite, and both parent drug and metabolite are excreted primarily via the kidneys. Saxagliptin reduces the degradation of the incretin hormone glucagon-like peptide-1, thereby enhancing its actions, and is associated with improved beta-cell function and suppression of glucagon secretion. Clinical trials of up to 24 weeks duration have shown that saxagliptin improves glycemic control in monotherapy and provides additional efficacy when used in combination with other oral antidiabetic agents (metformin, sulfonylurea, thiazolidinedione). Both fasting and postprandial glucose concentrations are reduce leading to clinically meaningful reductions in glycated hemoglobin, and due to the glucose-dependency of its mechanism of action, there is a low risk of hypoglycemia. Saxagliptin is reported to be well tolerated with a side-effect profile similar to placebo. It has a neutral effect on body weight and dose adjustment because of age, gender, or hepatic impairment is not necessary. Saxagliptin is being co-developed by Bristol-Myers-Squibb (New York, NY, USA) and AstraZeneca (Cheshire, UK), and is currently undergoing regulatory review. Topics: Adamantane; Administration, Oral; Blood Glucose; Clinical Trials as Topic; Diabetes Mellitus, Type 2; Dipeptides; Dipeptidyl-Peptidase IV Inhibitors; Drug Administration Schedule; Drug Evaluation, Preclinical; Drug Therapy, Combination; Glucagon-Like Peptide 1; Humans; Hypoglycemia; Safety; Treatment Outcome | 2009 |
Endocrine and metabolic response to gastric bypass.
Diabetes resolves in 80% of individuals undergoing successful Roux-en-Y gastric bypass. Absolute caloric restriction alone resulting from gastric anatomic changes indeed leads to weight loss; however, immediate effects in glycemic control often precede substantial weight loss typically associated with insulin sensitivity. One putative explanation relates to hormonal effects accompanying Roux-en-Y gastric bypass. We reviewed the existing and recent literature to investigate the hormonal changes accompanying Roux-en-Y gastric bypass.. Changes in levels of five candidate enteric hormones have been recently associated with early postoperative glycemic control following Roux-en-Y gastric bypass; the strongest effects are seen with variations in glucagon-like peptide-1, glucose-dependent insulinotropic peptide and ghrelin.. The unique hybridization of static anatomic restriction and dynamic absorptive bypass lends a duality to the beneficial effects of Roux-en-Y gastric bypass. This duality likely explains the short-term and long-term resolution of diabetes in patients undergoing Roux-en-Y gastric bypass. Topics: Caloric Restriction; Diabetes Mellitus, Type 2; Energy Intake; Gastric Bypass; Gastric Inhibitory Polypeptide; Ghrelin; Glucagon-Like Peptide 1; Humans; Incretins; Obesity, Morbid; Peptide Hormones; Weight Loss | 2009 |
Diabetes medications and body weight.
Tight diabetes control sometimes comes with a price: weight gain and hypoglycemia. Two of the three major recent trials that looked at the relationship between intensive diabetes control and cardiovascular events reported significant weight gain among the intensively treated groups. There is a growing concern that the weight gain induced by most diabetes medications diminishes their clinical benefits. On the other hand, there is a claim that treating diabetes with medications that are weight neutral or induces weight loss or less weight gain while minimizing those that increase body weight may emerge as the future direction for treating overweight and obese patients with diabetes. This review clarifies the weight effect of each of the currently available diabetes medications, and explains the mechanism of action behind this effect. Despite the great variability among reviewed clinical trials, the currently available evidence is quite sufficient to demonstrate the change in body weight in association with most of the currently available medications. This review also provides some guidelines on using diabetes medications during weight management programs. Topics: Abdominal Fat; Benzamides; Body Weight; Clinical Trials as Topic; Diabetes Mellitus, Type 2; Dipeptidyl Peptidase 4; Dipeptidyl-Peptidase IV Inhibitors; Double-Blind Method; Exenatide; Glucagon-Like Peptide 1; Glycoside Hydrolase Inhibitors; Humans; Hypoglycemic Agents; Insulin; Metformin; Obesity; Peptides; Randomized Controlled Trials as Topic; Sulfonylurea Compounds; Thiazolidinediones; Venoms; Weight Gain; Weight Loss | 2009 |
Is the current therapeutic armamentarium in diabetes enough to control the epidemic and its consequences? What are the current shortcomings?
The prevalence of diabetes is expected to rise together with an increase in morbidity and a reduction in life expectancy. A leading cause of death is cardiovascular disease, and hypertension and diabetes are additive risk factors for this complication. Selected treatment options should neither increase cardiovascular risk in patients with diabetes, nor increase risk of hyperglycaemia in patients with hypertension. The efficacy of present antihyperglycaemic agents is limited and new therapies, such as incretin-targeted agents, are under development. Even though most patients do not achieve glycated haemoglobin targets, trial data show that such interventions reduce the incidence of macrovascular events; however, intensive lowering may be detrimental in patients with existing cardiovascular disease. Currently available oral drugs do not address the key driver of type 2 diabetes--loss of functional beta-cell mass. In the future, new oral treatments must improve this, whilst providing durable blood glucose control and long-term tolerability. Topics: Diabetes Mellitus; Diabetes Mellitus, Type 2; Disease Outbreaks; Female; Gastric Inhibitory Polypeptide; Glucagon-Like Peptide 1; Humans; Hyperglycemia; Hypertension; Hypoglycemic Agents; Incretins; Male | 2009 |
Novel therapeutics for type 2 diabetes: incretin hormone mimetics (glucagon-like peptide-1 receptor agonists) and dipeptidyl peptidase-4 inhibitors.
Known treatments of type 2 diabetes mellitus have limitations such as weight gain, and hypoglycaemias. A new perspective is the use of incretin hormones and incretin enhancers. Incretins are defined as being responsible for the higher insulin release after an oral glucose load compared to an intravenous glucose load. The delicate balance of glucose homeostasis, in which incretin hormones are involved, is disturbed in type 2 diabetes mellitus. The incretin GLP-1 helps to maintain glucose homeostasis through stimulation of insulin secretion and inhibition of glucagon release in a glucose-dependent manner. This is associated with reductions in body weight, and no risk of hypoglycaemias. When classical oral agents have failed to maintain adequate glycaemic control, incretin mimetics may be of particular value for obese patients and those who have little control over meal sizes. Exenatide was marketed as a GLP-1 analogue and longer acting incretin mimetics such as liraglutide, albiglutide and others have the same pharmacological profile. In addition to incretin mimetics incretin enhancers which inhibit/delay degradation of incretins were developed: so-called DPP-4 inhibitors such as sitagliptin and vildagliptin are approved in Europe. Their differences from incretin mimetics include: oral bioavailability, less side effects with overdose, no direct CNS effects (nausea and vomiting) and no effect on weight. In rodent models of diabetes, but not yet in humans, GLP-1 receptor agonists and DPP-4 inhibitors increase islet mass and preserve beta-cell function. Incretin mimetics and enhancers expand type 2 diabetes treatment, are still not first line therapy and it is discussed if they are to be prophylactically used. Topics: Animals; Diabetes Mellitus, Type 2; Dipeptidyl-Peptidase IV Inhibitors; Exenatide; Gastric Inhibitory Polypeptide; Glucagon-Like Peptide 1; Glucagon-Like Peptide-1 Receptor; Glucose; Glycated Hemoglobin; Humans; Hypoglycemic Agents; Insulin; Insulin Secretion; Islets of Langerhans; Liraglutide; Peptides; Receptors, Glucagon; Signal Transduction; Venoms | 2009 |
Treatment of type 2 diabetes with glucagon-like peptide-1 receptor agonists.
The incretin system is an area of great interest for the development of new therapies for the management of type 2 diabetes. Existing antidiabetic drugs are often insufficient at getting patients to glycaemic goals. Furthermore, current treatment modalities are not able to prevent the continued ongoing decline in pancreatic beta-cell function and, lastly, they have a number of side effects including hypoglycaemia and weight gain. Glucagon-like peptide-1 (GLP-1) receptor agonists are a new class of pharmacological agents, which improve glucose homeostasis in a multifaceted way. Their effects include potentiation of glucose-stimulated insulin secretion, glucose-dependent inhibition of glucagon secretion and reduction in gastric emptying, appetite, food intake and body weight. Additionally, preclinical data suggest that they may preserve beta-cell mass and function. The incidence of hypoglycaemia with GLP-1 receptor agonists is low, the compounds have clinically relevant effects on body weight, and data are suggesting beneficial effects on cardiovascular risk factors. Exenatide was released in 2005 for the treatment of type 2 diabetes and liraglutide is expected to be approved by the Food and Drug Administration in US and the European Medical Agency in Europe for use in 2009. In this review, the available data on the two drugs are presented and discussed. Topics: Diabetes Mellitus, Type 2; Drug Therapy, Combination; Exenatide; Glucagon-Like Peptide 1; Glucagon-Like Peptide-1 Receptor; Humans; Hypoglycemic Agents; Liraglutide; Peptides; Randomized Controlled Trials as Topic; Receptors, Glucagon; Venoms | 2009 |
Liraglutide: a once-daily incretin mimetic for the treatment of type 2 diabetes mellitus.
To review the pharmacology, pharmacokinetics, efficacy, and safety of liraglutide, a glucagon-like peptide 1 (GLP-1) analog for the treatment of type 2 diabetes mellitus.. A MEDLINE search (1966-May 2009) was conducted for English-language articles using the terms glucagon-like peptide 1, incretin mimetic, NN2211, and liraglutide. Abstracts presented at the American Diabetes Association and European Association for the Study of Diabetes annual meetings in 2006, 2007, and 2008 were also searched for relevant data.. Articles pertinent to the pharmacology, pharmacokinetics, efficacy, and safety of liraglutide were reviewed.. Liraglutide is a GLP-1 analog with pharmacokinetic properties suitable for once-daily administration. Clinical trial data from large, controlled studies demonstrate the effectiveness of liraglutide in terms of hemoglobin A(1c) (A1C) reduction, reductions in body weight, and the drug's low risk for hypoglycemic events when used as monotherapy. Data also support benefits of liraglutide therapy on beta-cell responsiveness to glucose, with animal and in vitro data indicating potential benefits in beta-cell mass and neogenesis with liraglutide treatment. Liraglutide has been studied as monotherapy and in combination with metformin, glimepiride, and rosiglitazone for the treatment of type 2 diabetes. Additionally, comparative data with insulin glargine and exenatide therapy are available from Phase 3 trials providing practitioners valuable clinical data on which to base clinical decision making. Overall, liraglutide is well tolerated with dose-dependent nausea, vomiting, and diarrhea being the most commonly reported adverse events in clinical trials.. Once-daily administration may provide a therapeutic advantage for liraglutide over twice-daily exenatide, with similar improvements in A1C and body weight observed when liraglutide was compared with exenatide. The glucose-dependent mechanism of insulin release with GLP-1 agonist therapy holds potential clinical significance in the management of postprandial hyperglycemic excursions, with minimal risk of hypoglycemia. Topics: Animals; Blood Glucose; Controlled Clinical Trials as Topic; Diabetes Mellitus, Type 2; Glucagon-Like Peptide 1; Glycated Hemoglobin; Humans; Hypoglycemic Agents; Incretins; Liraglutide | 2009 |
Taspoglutide: a long acting human glucagon-like polypeptide-1 analogue.
Taspoglutide (R1583/BIM51077) is a new anti diabetic drug from Hoffmann-La Roche. The compound is to be administered as a subcutaneous injection once weekly and is also effective given bi-weekly. It is a long acting 10% formulation of (Aib 8-35) human glucagon-like polypeptide-1 (7 - 36 amides) with 93% homology with the native polypeptide. It activates the glucagon-like polypeptide-1 receptor. Phase III trials are currently in process.. To provide a critical review of taspoglutide based on available published data.. Information provided from the search on Internet has been reviewed. A clinical interpretation is given on a background of practical experience as an investigator in a clinical trial with taspoglutide.. Search on PubMed, EMBASE and Google gave hits on six clinical studies investigating taspoglutide of which the largest accounted for > 50% of the total study population. In addition, some animal studies were identified. Significant improvement on glucose control as well as several metabolic parameters has been shown with taspoglutide.. Data from the clinical trials are interpreted in a medical context. The prospects of taspoglutide in the treatment of diabetes type 2 and metabolic syndrome are discussed.. Taspoglutide is a new activator of the glucagon-like polypeptide-1 receptor. It is effective when injected once weekly and less effective when injected bi-weekly. In addition to its anti diabetic properties, taspoglutide has favorable effects on body weight and significantly reduces three of five diagnostic criteria for metabolic syndrome, namely glucose, waist circumference and fasting triglyceride. Topics: Animals; Blood Glucose; Body Weight; Clinical Trials, Phase III as Topic; Diabetes Mellitus, Type 2; Glucagon-Like Peptide 1; Glucagon-Like Peptide-1 Receptor; Glycated Hemoglobin; Humans; Hypoglycemic Agents; Insulin-Secreting Cells; Peptide Fragments; Peptides; Randomized Controlled Trials as Topic; Receptors, Glucagon; Treatment Outcome; Triglycerides | 2009 |
Emerging cardiovascular actions of the incretin hormone glucagon-like peptide-1: potential therapeutic benefits beyond glycaemic control?
Glucagon-like peptide-1 (GLP-1) is an incretin hormone secreted by the small intestine in response to nutrient ingestion. It has wide-ranging effects on glucose metabolism, including stimulation of insulin release, inhibition of glucagon secretion, reduction of gastric emptying and augmentation of satiety. Importantly, the insulinotropic actions of GLP-1 are uniquely dependent on ambient glucose concentrations, and it is this particular characteristic which has led to its recent emergence as a treatment for type 2 diabetes. Although the major physiological function of GLP-1 appears to be in relation to glycaemic control, there is growing evidence to suggest that it may also play an important role in the cardiovascular system. GLP-1 receptors (GLP-1Rs) are expressed in the heart and vasculature of both rodents and humans, and recent studies have demonstrated that GLP-1R agonists have wide-ranging cardiovascular actions, such as modulation of heart rate, blood pressure, vascular tone and myocardial contractility. Importantly, it appears that these agents may also have beneficial effects in the setting of cardiovascular disease (CVD). For example, GLP-1 has been found to exert cardioprotective actions in experimental models of dilated cardiomyopathy, hypertensive heart failure and myocardial infarction (MI). Preliminary clinical studies also indicate that GLP-1 infusion may improve cardiac contractile function in chronic heart failure patients with and without diabetes, and in MI patients after successful angioplasty. This review will discuss the current understanding of GLP-1 biology, examine its emerging cardiovascular actions in both health and disease and explore the potential use of GLP-1 as a novel treatment for CVD. Topics: Animals; Blood Glucose; Cardiovascular Agents; Cardiovascular Diseases; Cardiovascular System; Diabetes Mellitus, Type 2; Glucagon-Like Peptide 1; Glucagon-Like Peptide-1 Receptor; Humans; Hypoglycemic Agents; Incretins; Insulin; Insulin Secretion; Receptors, Glucagon | 2009 |
Pharmacotherapy of hyperglycemia.
Type 2 diabetes mellitus (T2DM) is a chronic, progressive disorder that affects more than 230 million people worldwide and is expected to affect 366 million by 2030. Both the prevalence of T2DM and the cost of its long term complications has driven the focus and emphasis on treatments aimed at reducing hyperglycemia and controlling hypertension and dyslipidemia. In the last 5 years new glucose lowering drugs acting on novel pathways have been developed, licensed and launched. These drugs include the glucagon-like peptide (GLP-1) agonists, exenatide, and dipeptidyl peptidase (DPP-IV) inhibitors such as sitagliptin and saxagliptin. This review describes current approaches to T2DM treatment, focusing on newer agents which tend to be associated with less hypoglycemia and possible weight loss, and addresses the potential roles of novel oral pharmacologic agents in the late-stages of development that might provide new options for the management of this disease. Topics: Animals; Clinical Trials as Topic; Diabetes Mellitus, Type 2; Dipeptidyl-Peptidase IV Inhibitors; Glucagon-Like Peptide 1; Humans; Hyperglycemia; Hypoglycemia; Hypoglycemic Agents | 2009 |
Liraglutide: a review of its use in type 2 diabetes mellitus.
Liraglutide (Victoza) is an acylated analogue of glucagon-like peptide-1 (GLP-1) indicated for the treatment of type 2 diabetes mellitus. In phase III studies, once-daily subcutaneous liraglutide improved glycaemic control compared with placebo or active comparator in adult patients with type 2 diabetes, both as monotherapy and in combination with one or two oral antidiabetic drugs such as metformin, sulfonylureas or thiazolidinediones. Liraglutide provided significantly better glycaemic control than rosiglitazone or insulin glargine in combination trials. At appropriate dosages, liraglutide was noninferior to glimepiride with respect to glycaemic control in a combination trial, but provided significantly better control than glimepiride or glibenclamide in monotherapy trials. Liraglutide improved pancreatic beta-cell function, generally led to weight loss, and was associated with a low risk of hypoglycaemia. Liraglutide was generally well tolerated, with the most common adverse events being gastrointestinal events, such as nausea, which decreased over time. Thus, liraglutide is an effective treatment option for use in patients with type 2 diabetes mellitus. Topics: Clinical Trials as Topic; Diabetes Mellitus, Type 2; Drug Therapy, Combination; Glucagon-Like Peptide 1; Humans; Hypoglycemia; Hypoglycemic Agents; Liraglutide; Treatment Outcome | 2009 |
The contribution of incretin hormones to the pathogenesis of type 2 diabetes.
The incretin effect, that is, the postprandial augmentation of insulin secretion by gastrointestinal hormones, mediates approximately 50-70% of the overall insulin responses after a mixed meal or glucose ingestion in healthy subjects. In patients with type 2 diabetes, the incretin effect is markedly reduced, and this has been attributed to defects in the secretion and insulinotropic action of the two main incretin hormones, namely gastric inhibitory polypeptide (GIP) and glucagon-like peptide 1 (GLP-1). It has been speculated that a reduced incretin effect might precede the onset of hyperglycaemia in patients with type 2 diabetes. However, the secretion and action of GIP and GLP-1 is relatively unaltered in normal glucose-tolerant individuals at high risk for type 2 diabetes (e.g., first-degree relatives) and a diminished incretin effect is also detectable in other types of diabetes, thereby arguing against such reasoning. This article will describe the defects in the incretin system in patients with type 2 diabetes, summarise their relevance in the development of hyperglycaemia and discuss the potential individual roles of GIP and GLP-1 in the pathogenesis of type 2 diabetes. Topics: Diabetes Mellitus; Diabetes Mellitus, Type 2; Gastric Inhibitory Polypeptide; Glucagon-Like Peptide 1; Humans; Incretins; Insulin; Postprandial Period; Prediabetic State | 2009 |
The spectrum of antidiabetic actions of GLP-1 in patients with diabetes.
This article focusses on the antidiabetic therapeutic potential of the incretin hormone glucagon-like peptide-1 (GLP-1) in the treatment of patients with type 2 diabetes mellitus (T2DM). T2DM is characterised by insulin resistance, impaired glucose-induced insulin secretion and inappropriately regulated glucagon secretion, which in combination eventually result in hyperglycaemia and, in the longer term, microvascular and macrovascular diabetic complications. Traditional treatment modalities - even multidrug approaches - for T2DM are often unsatisfactory in making patients reach glycaemic goals as the disease progresses caused by a steady, relentless decline in pancreatic beta-cell function. Furthermore, current treatment modalities are often limited by inconvenient dosing regimens and safety and tolerability issues, the latter including hypoglycaemia, body weight gain, oedema and gastrointestinal side effects. Therefore, the actions of GLP-1, which include the potentation of meal-induced insulin secretion and trophic effects on the beta-cell, have attracted a lot of interest. GLP-1 also inhibits glucagon secretion and suppresses food intake and appetite. Topics: Appetite; Diabetes Mellitus, Type 2; Eating; Glucagon-Like Peptide 1; Humans; Hypoglycemic Agents; Insulin; Insulin-Secreting Cells | 2009 |
Exenatide and liraglutide: different approaches to develop GLP-1 receptor agonists (incretin mimetics)--preclinical and clinical results.
The GLP-1 analogues exenatide and liraglutide stimulate insulin secretion and inhibit glucagon output in a glucose-dependent manner, slow gastric emptying and decrease appetite. The injectable glucagon-like peptide-1 (GLP-1) receptor agonist exenatide significantly improves glycaemic control, with average reductions in HbA1c of about 1.0% point, fasting plasma glucose of about 1.4 mmol l(-1), and causes a weight loss of approximately 2-3 kg after 30 weeks of treatment. The adverse effects are transient nausea and vomiting. The long-acting once-daily human GLP-1 receptor agonist liraglutide reduces HbA1c by about 1.0-2.0% point, weight by 1-3 kg and seems to have fewer gastrointestinal side effects than exenatide. The final place of the GLP-1 receptor agonists in the diabetes treatment algorithm will be clarified when we have long-term trials with cardiovascular end-points and data illustrating the effects on the progression of type 2 diabetes. Topics: Anti-Obesity Agents; Clinical Trials as Topic; Clinical Trials, Phase II as Topic; Delayed-Action Preparations; Diabetes Mellitus, Type 2; Exenatide; Glucagon-Like Peptide 1; Glucagon-Like Peptide-1 Receptor; Glycated Hemoglobin; Humans; Liraglutide; Peptides; Receptors, Glucagon; Venoms | 2009 |
Glucose lowering and anti-atherogenic effects of incretin-based therapies: GLP-1 analogues and DPP-4-inhibitors.
Type 2 diabetes is a chronic, progressive disease with a multi-faceted pathophysiology. Beyond the known defects of insulin resistance and beta-cell insufficiency, derangement of incretin hormones normally produced from the gut wall in response to food intake play an important role. In recent years, the 'incretin-based' therapies (IBTs) have been developed to address hyperglycemia through either mimicking the action of the endogenous incretin glucagon-like polypeptide (GLP-1) (GLP-1 receptor agonists) or by inhibiting the activity of the enzyme that degrades GLP-1 (the dipeptyl peptidase-4 inhibitors).. We reviewed available evidence on the glucose lowering and anti-atherogenic effects of IBT.. In addition to their glucose-lowering and weight-neutral or weight-reducing actions, IBT decrease systolic blood pressure and improve fasting and postprandial lipid parameters by reducing total-cholesterol, low-density lipoprotein-cholesterol and triglycerides concentrations, and increasing high-density lipoprotein-cholesterol values. Reduced high-sensitivity C-reactive protein levels and improved endothelial dysfunction have been reported too.. IBT have several beneficial effects on cardiovascular risk factors and, for this reason, it has been recently suggested to extend the use of these drugs in diabetic patients with cardiovascular complications. Yet, the long-term effects of IBT on subclinical or clinical atherosclerosis remain to be established by future studies. Topics: Animals; Atherosclerosis; Clinical Trials as Topic; Diabetes Mellitus, Type 2; Dipeptidyl Peptidase 4; Dipeptidyl-Peptidase IV Inhibitors; Glucagon-Like Peptide 1; Glucose; Humans; Incretins; Risk Factors | 2009 |
[Drug therapy of type 2 diabetes and cardiovascular prevention: potentials for liraglutide].
Recently, the European Medicines Agency (EMEA) Committee for Medicinal Products for Human Use (CHMP) adopted a positive opinion, recommending to grant a marketing authorization for liraglutide for the treatment of type 2 diabetes mellitus. Liraglutide is the first human glucagon-like peptide-1 (GLP-1) analog, based on the structure of native GLP-1, with pharmacokinetic properties suitable for once-daily dosing. In the phase III Liraglutide Effect and Action in Diabetes (LEAD) program, liraglutide has been shown to lower glycated hemoglobin to the same extent or more than other antidiabetic drugs including insulin. Liraglutide determines favorable changes in the global cardiovascular risk profile because its use is associated with weight loss, blood pressure reduction, as well as improvements of several cardiovascular risk biomarkers. Liraglutide is generally well tolerated, the most frequently reported adverse effect is transient nausea, and it does not seems to have significant interactions with medications commonly used for cardiovascular prevention. This article reviews, for the practicing cardiologist, the results of the LEAD program and explores liraglutide potentials for cardiovascular prevention in type 2 diabetes mellitus. Topics: Algorithms; Cardiovascular Diseases; Clinical Trials as Topic; Diabetes Complications; Diabetes Mellitus, Type 2; Evidence-Based Medicine; Glucagon-Like Peptide 1; Humans; Hypertension; Hypoglycemic Agents; Liraglutide; Obesity; Practice Guidelines as Topic; Risk Factors; Treatment Outcome | 2009 |
New therapies for diabesity.
Many patients with type 2 diabetes are obese (diabesity), and the two conditions together impose a particularly complex therapeutic challenge. Several differently acting agents are often required at the same time, encouraging development of more single-tablet combinations. Longer-acting (once daily and once weekly) injected agonists of glucagon-like peptide-1 are due to provide additional options to stimulate insulin secretion with weight loss and minimal risk of hypoglycemia. Further, dipeptidyl peptidase-4 inhibitors ("weight-neutral" insulinotropic agents) are also expected. Sodium-glucose cotransporter 2 inhibitors offer a new option to reduce hyperglycemia and facilitate weight loss by increasing the elimination of glucose in the urine. Selective peroxisome proliferator-activated receptor modulators are being studied to produce compounds with desired effects. Many other agents with antidiabetic and antiobesity activity are progressing in clinical development. Topics: Anti-Obesity Agents; Diabetes Mellitus, Type 2; Dipeptidyl-Peptidase IV Inhibitors; Glucagon-Like Peptide 1; Humans; Hypoglycemic Agents; Obesity; Sodium-Glucose Transporter 2; Sodium-Glucose Transporter 2 Inhibitors | 2009 |
Albiglutide, an albumin-based fusion of glucagon-like peptide 1 for the potential treatment of type 2 diabetes.
Albiglutide, under development by GlaxoSmithKline plc for the treatment of type 2 diabetes mellitus (T2DM), is an albumin-fusion peptide. The compound is a mimetic of glucagon-like peptide 1 (GLP-1), a hormone that decreases glucose levels, but has a short half-life because of degradation by dipeptidyl peptidase (DPP)-4. Albiglutide has a longer half-life as a result of its fusion with albumin and its resistance to degradation by DPP-4, caused by an amino acid substitution (Ala to Glu) at the DPP-4-sensitive hydrolysis site. Data from phase II clinical trials in patients with T2DM revealed that albiglutide was well tolerated and that the drug significantly reduced HbA1c levels compared with placebo. At the time of publication, phase III trials assessing albiglutide alone and in combination with other antidiabetic drugs were recruiting patients with T2DM. Albiglutide represents a promising new drug for the treatment of patients with T2DM; the results of long-term trials are awaited with interest. Topics: Albumins; Animals; Area Under Curve; Clinical Trials as Topic; Diabetes Mellitus, Type 2; Drug Evaluation, Preclinical; Glucagon-Like Peptide 1; Humans; Hypoglycemic Agents; Patents as Topic | 2009 |
Treating type 2 diabetes: incretin mimetics and enhancers.
As a consequence of excess abdominal adiposity and genetic predisposition, type 2 diabetes is a progressive disease, often diagnosed after metabolic dysfunction has taken hold of multiple organ systems. Insulin deficiency, insulin resistance and impaired glucose homeostasis resulting from beta-cell dysfunction characterize the disease. Current treatment goals are often unmet due to insufficient treatment modalities. Even when combined, these treatment modalities are frequently limited by safety, tolerability, weight gain, edema and gastrointestinal intolerance. Recently, new therapeutic classes have become available for treatment. This review will examine the new therapeutic classes of incretin mimetics and enhancers in the treatment of type 2 diabetes. Topics: Biomarkers; Blood Glucose; Diabetes Mellitus, Type 2; Dipeptidyl Peptidase 4; Dipeptidyl-Peptidase IV Inhibitors; Glucagon-Like Peptide 1; Glycated Hemoglobin; Humans; Hypoglycemic Agents; Incretins; Insulin; Insulin Resistance; Insulin-Secreting Cells; Treatment Outcome | 2009 |
Lipid receptors and islet function: therapeutic implications?
G-protein coupled receptors (GPCRs) are targets of approximately 30% of currently marketed drugs. Over the last few years, a number of GPCRs expressed in pancreatic beta-cells and activated by lipids have been discovered. GPR40 was shown to be activated by medium- to long-chain fatty acids (FAs). It has since been shown that GPR40 contributes to FA amplification of glucose-induced insulin secretion. Although some controversy still exists as to whether GPR40 agonists or antagonists should be designed as novel type 2 diabetes drugs, data obtained in our laboratory and others strongly suggest that GPR40 agonism might represent a valuable therapeutic approach. GPR119 is expressed in pancreatic beta-cells and enteroendocrine L-cells, and augments circulating insulin levels both through its direct insulinotropic action on beta-cells and through FA stimulation of glucagon-like peptide 1 (GLP-1) secretion. GPR120 is expressed in L-cells and was also shown to mediate FA-stimulated GLP-1 release. Finally, GPR41 and GPR43 are receptors for short-chain FAs and may indirectly regulate beta-cell function via adipokine secretion. Although the discovery of these various lipid receptors opens new and exciting avenues of research for drug development, a number of questions regarding their mechanisms of action and physiological roles remain to be answered. Topics: Animals; Diabetes Mellitus, Type 2; Fatty Acids, Nonesterified; Gene Expression; Glucagon-Like Peptide 1; Hypoglycemic Agents; Insulin; Insulin Secretion; Islets of Langerhans; Mice; Mice, Mutant Strains; Rats; Receptors, G-Protein-Coupled | 2009 |
Beyond glycemic control: treating the entire type 2 diabetes disorder.
The prevalence of type 2 diabetes mellitus, which is directly associated with overweight/obesity and increased cardiovascular disease risk, is projected to continue to increase during the next few decades. Traditionally, treatment has focused primarily on glycemic control, but accumulating evidence suggests that the clinical management of patients with type 2 diabetes requires a more comprehensive approach to minimize associated morbidity and mortality. Because the majority (80%-90%) of patients with type 2 diabetes are overweight or obese, effective glucose control and weight loss are the cornerstones of initial management. Both effective glucose control and therapy to reduce cardiovascular risk factors, including overweight/obesity, are needed to prevent the complications of type 2 diabetes. Most conventional antidiabetes agents, including sulfonylureas, thiazolidinediones, and insulin, improve glycemic control but are associated with weight gain or, as with metformin, are weight-neutral or weight-sparing. The incretin-based therapies, such as the glucagon-like peptide-1 (GLP-1) receptor agonists and the dipeptidyl peptidase-4 inhibitors, have been shown to be safe and effective in lowering glucose while eliciting favorable effects on weight (ie, weight-reducing and weight-neutral, respectively). The effects of these agents on other parameters of cardiovascular risk are also being studied. Advances in GLP-1 receptor agonist therapy include development of agents with longer durations of activity allowing for more convenient dosing of therapies for patients with type 2 diabetes, which should lead to better patient compliance, adherence, and overall clinical outcomes. Topics: Algorithms; Caloric Restriction; Cardiovascular Diseases; Comorbidity; Delayed-Action Preparations; Diabetes Complications; Diabetes Mellitus, Type 2; Diet, Carbohydrate-Restricted; Dipeptidyl Peptidase 4; Dipeptidyl-Peptidase IV Inhibitors; Exenatide; Female; Glucagon-Like Peptide 1; Glucagon-Like Peptide-1 Receptor; Humans; Hypoglycemic Agents; Liraglutide; Male; Metabolic Syndrome; Obesity; Peptides; Prevalence; Receptors, Glucagon; Risk Factors; Risk Reduction Behavior; Venoms | 2009 |
The impact of weight gain on motivation, compliance, and metabolic control in patients with type 2 diabetes mellitus.
Patients with type 2 diabetes, approximately 85% of whom are overweight or obese, often have an increased incidence of cardiovascular disease (CVD) risk factors such as hypertension and dyslipidemia. Both type 2 diabetes and obesity are independent risk factors for CVD. Unfortunately, many therapies aimed at maintaining and improving glucose control are associated with weight gain. Among the older antidiabetes agents, most, including the insulin secretagogues and sensitizers, can lead to weight gain, except for metformin, which is weight-neutral. Among the newer agents, the dipeptidyl peptidase-4 inhibitors generally are weight-neutral in addition to lowering glucose, while the glucagon-like peptide-1 receptor agonists lead to weight reduction. Patients with type 2 diabetes are at an increased risk for both diabetes- and CV-related outcomes, and weight reduction is an important component of diabetes management. Weight gain in patients with type 2 diabetes can contribute to patient frustration and may negatively impact their compliance to therapeutic regimens. The selection of antidiabetes agents that not only improve glucose control but reduce or have a neutral effect on weight with beneficial effects on lipids are ideal options for managing patients with type 2 diabetes. Topics: Cardiovascular Diseases; Diabetes Mellitus, Type 2; Diet, Carbohydrate-Restricted; Exenatide; Glucagon-Like Peptide 1; Health Knowledge, Attitudes, Practice; Humans; Hypoglycemic Agents; Incretins; Motivation; Obesity; Patient Compliance; Peptides; Risk Management; Self Care; Venoms; Weight Gain | 2009 |
Liraglutide in type 2 diabetes: from pharmacological development to clinical practice.
The novel drug class of GLP-1 analogues is extremely promising, since existing evidence suggests they can address many of the unmet needs of diabetes treatment, i.e., long-term efficacy, low risk of hypoglycemia, cardiovascular protection, weight loss, long-term safety and tolerability. Besides the already available exenatide, liraglutide is expected to arrive soon on the market. It is a human GLP-1 analogue with high homology (97%) to native hormone. A comprehensive phase III evaluation consisting of six randomized clinical trials--the "Liraglutide Effect and Action Diabetes (LEAD) program"--was recently completed, involving 6500 people seen in 600 sites in 41 countries worldwide. Aim of the LEAD program was to evaluate efficacy and safety of liraglutide as monotherapy and in combination with commonly used antidiabetic drugs. In all studies, once-daily liraglutide was well tolerated, significantly improved metabolic control, and reduced body weight, with low rates of hypoglycemia. Transient nausea was the most common side effects. Additional beneficial effects ofliraglutide on beta-cell function, systolic blood pressure, and cardiovascular risk were also documented. If these encouraging results will be confirmed by long-term studies, liraglutide will acquire a prominent role among the main therapeutic options not only as add-on treatments in case of secondary failure, but also as an early strategy to reduce the burden of diabetes and its complications. Topics: Animals; Diabetes Mellitus, Type 2; Drug Evaluation, Preclinical; Glucagon-Like Peptide 1; Humans; Liraglutide; Treatment Outcome | 2009 |
Harnessing the weight-regulating properties of glucagon-like peptide-1 in the treatment of type 2 diabetes.
Obesity is associated with increased insulin resistance and is a well-recognized factor for the development of type 2 diabetes. Unfortunately, most diabetes therapies are associated with further weight gain, a most unwelcome characteristic, given the association of weight gain with deteriorating metabolic control, worsening cardiovascular profiles and decreased adherence to treatment. Therapies that effectively control glycaemia without weight gain or with concomitant weight loss are needed. The aim of this article was to review the existing preclinical and clinical evidences, showing that the family of glucagon-like peptide-1 (GLP-1)-based therapies fulfils these criteria by harnessing the beneficial properties of GLP-1, a naturally occurring incretin hormone with a strong blood glucose-lowering action and the ability to induce weight loss. Topics: Animals; Body Weight; Diabetes Mellitus, Type 2; Glucagon-Like Peptide 1; Humans; Hypoglycemic Agents; Incretins; Insulin Resistance; Obesity; Weight Loss | 2009 |
The effects of glucagon-like peptide-1 on the beta cell.
Type 2 diabetes is a progressive disease characterized by insulin resistance and impaired beta-cell function. Treatments that prevent further beta-cell decline are therefore essential for the management of type 2 diabetes. Glucagon-like peptide-1 (GLP-1) is an incretin hormone that is known to stimulate glucose-dependent insulin secretion. Furthermore, GLP-1 appears to have multiple positive effects on beta cells. However, GLP-1 is rapidly degraded by dipeptidyl peptidase-4 (DPP-4), which limits the clinical relevance of GLP-1 for the treatment of type 2 diabetes. Two main classes of GLP-1-based therapies have now been developed: DPP-4 inhibitors and GLP-1 receptor agonists. Liraglutide and exenatide are examples of GLP-1 receptor agonists that have been developed to mimic the insulinotropic characteristics of endogenous GLP-1. Both have demonstrated improved beta-cell function in patients with type 2 diabetes, as assessed by homoeostasis model assessment-B analysis and proinsulin : insulin ratio. Additionally, liraglutide and exenatide are able to enhance first- and second-phase insulin secretion and are able to restore beta-cell sensitivity to glucose. Preclinical studies have shown that both liraglutide and exenatide treatment can increase beta-cell mass, stimulate beta-cell proliferation, increase beta-cell neogenesis and inhibit beta-cell apoptosis. Clinical studies are needed to confirm these findings in humans. Replication of these data in humans could have important clinical implications for the treatment of type 2 diabetes. Topics: Diabetes Mellitus, Type 2; Exenatide; Glucagon-Like Peptide 1; Humans; Hypoglycemic Agents; Incretins; Insulin-Secreting Cells; Liraglutide; Peptides; Venoms | 2009 |
Impact of glucagon-like peptide-1 on endothelial function.
Cardiovascular (CV) disease is the major cause of mortality and morbidity in individuals with diabetes. Individuals with diabetes often have a variety of factors such as hyperglycaemia, dyslipidaemia, hypertension, insulin resistance and obesity, which increase their risks of endothelial dysfunction and CV disease. The incretin hormones, such as glucagon-like peptide-1 (GLP-1), induce the glucose-dependent secretion of insulin, improve beta-cell function and induce slowing of gastric emptying and feelings of satiety - which result in reduced food intake and weight loss. Therapeutic treatments targeting the incretin system, such as GLP-1 receptor agonists, offer the potential to address beta-cell dysfunction (one the underlying pathogenic mechanisms of type 2 diabetes), as well as the resulting hyperglycaemia. Initial evidence now suggests that incretins could have beneficial effects on endothelial function and the CV system through both indirect effects on the reduction of hyperglycaemia and direct effects mediated through GLP-1 receptor-dependent and -independent mechanisms. If these initial findings are confirmed in larger clinical trials, GLP-1 receptor antagonists could help to address the major CV risks faced by patients with diabetes. Topics: Cardiovascular Diseases; Diabetes Mellitus, Type 2; Diabetic Angiopathies; Endothelium, Vascular; Glucagon-Like Peptide 1; Humans; Hypoglycemic Agents; Incretins; Weight Loss | 2009 |
The safety and efficacy of liraglutide with or without oral antidiabetic drug therapy in type 2 diabetes: an overview of the LEAD 1-5 studies.
Liraglutide is a new glucagon-like peptide-1 (GLP-1) receptor agonist and a true GLP-1 analogue. After successful phase 2 studies, liraglutide was assessed in a series of phase 3 trials [(Liraglutide Effect and Action in Diabetes (LEAD)] designed to demonstrate efficacy and safety across the continuum of type 2 diabetes antihyperglycaemic care, both as monotherapy and in combination with commonly used oral antidiabetic drugs (OADs). The LEAD programme also compared liraglutide with other OADs. As a monotherapy, liraglutide demonstrated significant improvements in glycaemic control in comparison with glimepiride. When combined with one or two OADs, reductions in haemoglobin A1c, fasting plasma glucose and postprandial glucose were generally greater with liraglutide than with comparators. Throughout the trials, liraglutide was associated with weight reduction; in most instances, the reduction from baseline was significantly greater than that seen with comparators. Improvements in assessments of beta-cell function were consistently shown with liraglutide treatment across all trials. Furthermore, reductions in systolic blood pressure were reported. Liraglutide was associated with a low risk of hypoglycaemia and was generally well tolerated. The majority of adverse effects were gastrointestinal, the most frequent of which was nausea. Topics: Blood Glucose; Blood Pressure; Clinical Trials, Phase II as Topic; Diabetes Mellitus, Type 2; Glucagon-Like Peptide 1; Humans; Hypoglycemic Agents; Liraglutide; Randomized Controlled Trials as Topic; Risk Factors; Treatment Outcome | 2009 |
Incretin-based therapies: therapeutic rationale and pharmacological promise for type 2 diabetes.
To highlight the therapeutic promise of the incretin hormone glucagon-like peptide-1 (GLP-1), the consequent rationale for therapies acting through GLP-1-mediated pathways in type 2 diabetes mellitus (T2DM), and the emerging clinical role of the dipeptidyl peptidase-4 (DPP-4) inhibitors and GLP-1 receptor agonists.. The PubMed database was searched (using terms including incretins, GLP-1, GIP, DPP-4), along with recent ADA and EASD abstracts.. Many traditional drugs used for T2DM fail to achieve and maintain glycemic control, and possess limitations such as risk for hypoglycemia and weight gain. GLP-1 is a gut-derived hormone that glucose-dependently stimulates insulin secretion while simultaneously reducing gastric emptying and appetite. Other physiological actions of GLP-1 may benefit the cardiovascular system and beta-cell function. Recently developed drug therapies that mimic or prolong the action of this hormone, therefore, have great promise in the treatment of T2DM.. The GLP-1 receptor agonists and DPP-4 inhibitors are incretin-based therapies that are now becoming established as effective therapies for T2DM to be used either as monotherapy or added to other antidiabetes drugs. They enable improvements to be made in glycemic control without weight gain, with a low risk for hypoglycemia, and with potential additional clinical benefits. Topics: Diabetes Mellitus, Type 2; Dipeptidyl-Peptidase IV Inhibitors; Glucagon-Like Peptide 1; Glucagon-Like Peptide-1 Receptor; Humans; Incretins; Receptors, Glucagon | 2009 |
New developments in incretin-based therapies: the current state of the field.
To update readers on developments in incretin therapies since the previous JAANP supplement in 2007; specifically, to describe clinical data for currently available incretin-based therapies as well as those under consideration by regulatory agencies.. Medline search for peer-reviewed publications.. Incretin-based therapies have pharmacologic properties that avoid some key limitations of previous treatments, such as hypoglycemia and weight gain. Certain agents also lower blood pressure and have the potential to reduce cardiovascular risk. The insulin-secreting action of incretin-based therapies only occurs under hyperglycemic conditions, thus minimizing the risk of hypoglycemia, unless combined with a sulfonylurea. The DPP-4 inhibitors are orally administered and demonstrate modest A1c reductions (0.6%-0.8%); the best results occur when combined with metformin. Glucagon-like peptide-1 (GLP-1) receptor agonists liraglutide and exenatide have shown greater A1c reductions (typically ≥ 1.1% and as high as 1.7%), and these agents have beneficial ancillary effects, including weight and systolic blood pressure reduction. Both DPP-4 inhibitors and GLP-1 receptor agonists have shown the ability to improve pancreatic beta-cell function in early studies.. Data are provided on the efficacy and tolerability of approved incretin therapies, and on treatments currently in regulatory review, in order to inform readers and guide their practice. Topics: Diabetes Mellitus, Type 2; Dipeptidyl-Peptidase IV Inhibitors; Glucagon-Like Peptide 1; Glucagon-Like Peptide-1 Receptor; Humans; Incretins; Receptors, Glucagon | 2009 |
Optimizing outcomes with incretin-based therapies: practical information for nurse practitioners to share with patients.
To introduce the role of incretin therapies and suggest strategies for nurse practitioners to implement them in practice.. PubMed, Medline, summary of product characteristics/package inserts.. Incretin-based therapies offer a new alternative to currently available agents. They provide adequate levels of glycemic control and are associated with low incidence of hypoglycemia and weight gain. Dipeptidyl peptidase-4 inhibitors, for example sitagliptin, have a modest effect on A1c levels (-0.7%) as monotherapy; however, they reduce A1c to a greater extent when combined with metformin ( approximately 2.0%). Typical starting dose of sitagliptin is 100 mg; dose adjustments are required in subjects with renal complications. Glucagon-like peptide-1 receptor agonists, exenatide and liraglutide, reduce A1c levels (often in excess of 1.5%) and body weight. Exenatide has a starting dose of 5 mug and is not recommended for patients with hepatic impairment or severe/end-stage renal disease. Liraglutide has been found to benefit from a stepwise dose escalation (i.e., 0.6 mg weekly increments) until a 1.8-mg dose is reached. Unlike exenatide, dose adjustments in patients with renal and hepatic complications are not required.. Incretin-based therapies may help to overcome some of the drawbacks of current therapies used to treat type 2 diabetes. Topics: Diabetes Mellitus, Type 2; Dipeptidyl-Peptidase IV Inhibitors; Glucagon-Like Peptide 1; Glucagon-Like Peptide-1 Receptor; Incretins; Nurse Practitioners; Nurse's Role; Patient Education as Topic; Receptors, Glucagon | 2009 |
[Role of the endocrine system in the pathogenesis of non-alcoholic fatty liver disease].
The most frequent liver disorder in metabolic syndrome is the nonalcoholic fatty liver disease. Its pathogenesis is a complex, multifactorial process, characterized by insulin resistance and involvement of the endocrine system. Hypothyroidism may lead to nonalcoholic steatohepatitis via hyperlipidemia and obesity. Adult patients with growth hormone deficiency have a metabolic syndrome-like phenotype with obesity and many characteristic metabolic alterations. The chronic activation of the hypothalamic-pituitary-adrenal axis results in metabolic syndrome as well. Cushing's syndrome has also features of metabolic syndrome. Mild elevation of transaminase activities is commonly seen in patients with adrenal failure. Non-alcoholic steatosis is twice as common in postmenopusal as in premenopausal women and hormonal replacement therapy decreases the risk of steatosis. Insulin resistance, diabetes mellitus type 2, sleeping apnoe syndrome, cardiovascular disorders and non-alcoholic fatty liver disease are more frequent in polycystic ovary syndrome. Hypoandrogenism in males and hyperandrogenism in females may lead to fatty liver via obesity and insulin resistance. Adipokines (leptin, acylation stimulating protein, adiponectin) have a potential role in the pathogenesis of nonalcoholic fatty liver. The alterations of endocrine system must be considered in the background of cryptogenic liver diseases. The endocrine perspective may help the therapeutic approaches in the future. Topics: Adipokines; Adrenal Glands; Adult; Androgens; Cushing Syndrome; Diabetes Mellitus, Type 2; Endocrine System; Estrogens; Fatty Liver; Female; Glucagon-Like Peptide 1; Gonadal Steroid Hormones; Humans; Hyperlipidemias; Hypothalamus; Hypothyroidism; Insulin; Insulin Resistance; Male; Metabolic Syndrome; Obesity; Pancreas; Pituitary Gland; Polycystic Ovary Syndrome; Postmenopause; Thyroid Gland | 2009 |
DPP-4 inhibitors in clinical practice.
Type 2 diabetes is a very common worldwide disorder, with major consequences for patients, society, and health care services. Good glycemic control is an important aspect of diabetes management because it has a significant impact on diabetes-related microvascular and possibly macrovascular complications. Based on our understanding of the pathogenesis of diabetes, multiple pharmacological interventions have been developed in the past 60 years. Although effective, none have had a lasting effect on glycemic control because of the progressive nature of type 2 diabetes requiring combination therapies and insulin treatment. In addition, several pharmacologic interventions have undesirable side effects, including hypoglycemia and weight gain. Drugs targeting the incretin pathway are the latest addition to the available antidiabetes agents. Incretin-based therapy is either delivered orally (dipeptidyl peptidase-4 [DPP-4]) inhibitors or injected subcutaneously (glucagon-like peptide-1 [GLP-1] mimetics and analogues). Dipeptidyl peptidase-4 inhibitors are effective either as a single or combination therapy in lowering glycated hemoglobin, fasting and postprandial glucose levels, with a low incidence of hypoglycemia and no weight gain. There are 3 DPP-4 inhibitors currently available (sitagliptin, saxagliptin, and vildagliptin), with more expected to be available in the future. In this article, we review the scientific background for incretin-based therapy and the available evidence regarding the role and efficacy of DPP-4 inhibitors in the treatment of patients with type 2 diabetes. Topics: Adamantane; Administration, Oral; Diabetes Mellitus, Type 2; Dipeptides; Dipeptidyl-Peptidase IV Inhibitors; Glucagon-Like Peptide 1; Humans; Hypoglycemic Agents; Incretins; Nitriles; Pyrazines; Pyrrolidines; Sitagliptin Phosphate; Triazoles; Vildagliptin | 2009 |
[Liraglutide: a human GLP-1 analogue for the treatment of diabetes mellitus type 2].
The GLP-1-receptor-agonist liraglutide (Victoza) has been approved for the treatment of diabetes mellitus type 2 in Europe. Liraglutide is the first human GLP-1 analogue which is applied once a day. Efficacy and safety of liraglutide were investigated in the broad LEAD-study-programme in comparison with placebo and other common therapeutics for the treatment of diabetes mellitus type 2. Liraglutide has been approved for the combination with metformin and/or a sulfonylurea or with metformin and a thiazolidinedione, if treatment with one or a combination of these drugs is not sufficient for an adequate blood glucose control. Topics: Diabetes Mellitus, Type 2; Drug Therapy, Combination; Glucagon-Like Peptide 1; Humans; Hypoglycemic Agents; Liraglutide; Metformin; Thiazolidinediones | 2009 |
Differentiating incretin therapies based on structure, activity, and metabolism: focus on liraglutide.
The incretin effect, mediated by glucagon-like peptide-1 (GLP-1) and glucose-dependent insulinotropic polypeptide (GIP), plays an important role in the regulation of insulin secretion in response to oral glucose. The discovery of deficiencies in incretin pathways associated with development of type 2 diabetes mellitus has propelled the growth of incretin-based therapies in patients with this disease. The basic rationale for incretin-based therapies, including both GLP-1-receptor agonists and dipeptidyl peptidase-4 (DPP-4) inhibitors is reviewed, focusing on their roles in glucose regulation and potential therapeutic benefits. Increased awareness of the differences among incretin mimetics, GLP-1 analogs, and DPP-4 inhibitors, including their structures, half-lives, dosages, hemoglobin A(1c)-lowering capacities, effects on weight, and adverse events will help shape the future of these therapeutic agents. Improved understanding of the mechanism of action and clinical effects of incretin-based therapies will help advance their appropriate use within clinical practice. Topics: Amino Acid Sequence; Animals; Blood Glucose; Diabetes Mellitus, Type 2; Glucagon-Like Peptide 1; Humans; Incretins; Liraglutide; Molecular Sequence Data; Structure-Activity Relationship | 2009 |
Pharmacokinetics and pharmacodynamics of liraglutide, a long-acting, potent glucagon-like peptide-1 analog.
Despite the continued development of new pharmacologic agents, and the use of several existing drug therapies, almost two thirds of patients with type 2 diabetes mellitus do not reach the American Diabetes Association-targeted hemoglobin A(1c) level of less than 7.0%. Therefore, maintaining adequate metabolic control remains a primary concern for many clinicians and patients. It is now well recognized that in addition to defective secretion and action of insulin, other hormones also potentially play a role in the development and progression of type 2 diabetes. Glucagon-like peptide-1 (GLP-1) is a gastrointestinal hormone from the incretin family, which stimulates insulin secretion and plays an important role in regulating the enteroinsular axis. Incretin-based therapies are the newest class of glucose-lowering drugs for the treatment of type 2 diabetes and may help address some of the unmet needs in this therapeutic area. Liraglutide is a once-daily GLP-1 analog that has been recently approved by the European Union regulatory agency and is in late-stage review by the United States Food and Drug Administration for the treatment of type 2 diabetes. The pharmacokinetic and pharmacodynamic properties of liraglutide and mechanisms behind its protracted action, which in turn enables enhanced glycemic control, are reviewed. Topics: Amino Acid Sequence; Animals; Delayed-Action Preparations; Diabetes Mellitus, Type 2; Glucagon-Like Peptide 1; Humans; Liraglutide; Molecular Sequence Data; Time Factors | 2009 |
Clinical studies of liraglutide, a novel, once-daily human glucagon-like peptide-1 analog for improved management of type 2 diabetes mellitus.
Liraglutide, a new glucagon-like peptide-1 (GLP-1)-receptor agonist with 97% homology to human GLP-1, can be administered once/day independent of meals in patients with type 2 diabetes mellitus. Clinical trials have demonstrated its efficacy in controlling hyperglycemia, helping patients achieve hemoglobin A(1c) level goals; in facilitating weight loss, and in improving indexes of beta-cell function when used alone or in combination with metformin, glimepiride, or rosiglitazone. These studies also suggest that liraglutide may be associated with modest improvements in systolic blood pressure. Data from a comparative trial of liraglutide and insulin glargine have suggested that liraglutide provides greater glycemic control with less weight gain, and another study demonstrated that liraglutide provides greater improvements in glycemic control with less hypoglycemia than exenatide and with comparable weight loss. Although liraglutide is well tolerated and is associated with low rates of hypoglycemia, transient and mild nausea can occur when therapy is initiated. However, rates of hypoglycemia appear to be lower and nausea appears to be less persistent with liraglutide than with exenatide. Even though data on the long-term use of liraglutide are still needed, this drug may provide a useful treatment option in patients poorly controlled with dietary modification and exercise and in those whose diabetes is inadequately controlled by oral antidiabetic agents. Topics: Animals; Diabetes Mellitus, Type 2; Disease Management; Drug Administration Schedule; Glucagon-Like Peptide 1; Humans; Hyperglycemia; Liraglutide; Randomized Controlled Trials as Topic | 2009 |
Role of the incretin pathway in the pathogenesis of type 2 diabetes mellitus.
Nutrient intake stimulates the secretion of the gastrointestinal incretin hormones, glucagon-like peptide-1 (GLP-1) and glucose-dependent insulinotropic polypeptide (GIP), which exert glucose-dependent insulinotropic effects and assist pancreatic insulin and glucagon in maintaining glucose homeostasis. GLP-1 also suppresses glucose-dependent glucagon secretion, slows gastric emptying, increases satiety, and reduces food intake. An impaired incretin system, characterized by decreased responsiveness to GIP and markedly reduced GLP-1 concentration, occurs in individuals with type 2 diabetes mellitus (T2DM). The administration of GLP-1 improves glycemic control, but GLP-1 is rapidly degraded by the enzyme dipeptidyl peptidase-4 (DPP-4). Exenatide, a DPP-4-resistant exendin-4 GLP-1 receptor agonist, exhibits the glucoregulatory actions of GLP-1 and reduces body weight in patients with T2DM. It may possess cardiometabolic actions with the potential to improve the cardiovascular risk profile of patients with T2DM. DPP-4 inhibitors such as sitagliptin and saxagliptin increase endogenous GLP-1 concentration and demonstrate incretin-associated glucoregulatory actions in patients with T2DM. DPP-4 inhibitors are weight neutral. A growing understanding of the roles of incretin hormones in T2DM may further clarify the application of incretin-based treatment strategies. Topics: Adamantane; Blood Glucose; Diabetes Mellitus, Type 2; Dipeptides; Dipeptidyl-Peptidase IV Inhibitors; Exenatide; Glucagon-Like Peptide 1; Glutaminase; Homeostasis; Humans; Hypoglycemic Agents; Incretins; Intracellular Signaling Peptides and Proteins; Peptides; Pyrazines; Signal Transduction; Sitagliptin Phosphate; Triazoles; Venoms | 2009 |
A review of efficacy and safety data regarding the use of liraglutide, a once-daily human glucagon-like peptide 1 analogue, in the treatment of type 2 diabetes mellitus.
Liraglutide, a human glucagon-like peptide 1 (GLP-1) analogue that has received marketing approval from the European Commission, is a treatment for type 2 diabetes mellitus (DM) that is administered as a once-daily subcutaneous injection.. The aim of this review was to summarize the efficacy and safety data published about liraglutide, focusing on data from Phase III clinical trials.. Relevant English-language publications were identified through a search of MEDLINE and EMBASE (from 1948 to October 2009). The search terms included the following: GLP-1, incretin effect, liraglutide, NN2211, exenatide, sitagliptin, and vildagliptin. Original research papers about liraglutide that were published in peer-reviewed journals were considered.. The literature search identified 39 relevant publications. The efficacy and tolerability of oncedaily liraglutide at doses of 0.6, 1.2, and 1.8 mg for type 2 DM, in combination with, and compared with, other type 2 DM treatments were investigated in the Liraglutide Effect and Action in Diabetes (LEAD) Phase III clinical trial program. In the LEAD studies, consistent reductions in glycosylated hemoglobin (HbA(1c)) of up to 1.6% were seen with liraglutide, and up to 66% of patients achieved the HbA(1c) goal of <7%. Fasting and postprandial plasma glucose levels were also consistently reduced across the LEAD trials by up to 43 mg/dL (2.4 mmol/L) and 49 mg/dL (2.7 mmol/L), respectively. Hypoglycemia was reported at a rate of 0.03 to 1.9 events per patient annually. Liraglutide significantly improved beta-cell function, as measured by homeostasis model assessment for beta-cell function analysis (20%-44%) and by ratios of pro-insulin to insulin (-0.11 to 0.01). Consistent reductions in systolic blood pressure up to 6.7 mm Hg were also observed for liraglutide treatment. Liraglutide treatment, as monotherapy and in combination with oral antidiabetic drugs (OADs), was associated with weight loss of up to 3.24 kg. Overall, liraglutide was well tolerated. Nausea was the most common adverse event observed with liraglutide treatment, reported by 5% to 29% of patients; however, nausea was generally mild and transient.. Once-daily liraglutide was effective and well tolerated when used as monotherapy or in combination with OADs in patients with type 2 DM, and is therefore a promising new treatment option for the management of type 2 DM. Topics: Animals; Blood Glucose; Blood Pressure; Body Weight; Clinical Trials, Phase II as Topic; Clinical Trials, Phase III as Topic; Diabetes Mellitus, Type 2; Diabetic Angiopathies; Drug Evaluation, Preclinical; Glucagon-Like Peptide 1; Humans; Hypoglycemic Agents; Incretins; Insulin-Secreting Cells; Liraglutide; Risk Factors | 2009 |
Mechanisms of early improvement/resolution of type 2 diabetes after bariatric surgery.
Bariatric surgery represents the main option for obtaining substantial and long-term weight loss in morbidly obese subjects. In addition, malabsorptive (biliopancreatic diversion, BPD) and restrictive (roux-en-Y gastric bypass, RYGB) surgery, originally devised to treat obesity, has also been shown to help diabetes. Indeed, type 2 diabetes is improved or even reversed soon after these operations and well before significant weight loss occurs. Two hypotheses have been proposed to explain the early effects of bariatric surgery on diabetes--namely, the hindgut hypothesis and the foregut hypothesis. The former states that diabetes control results from the more rapid delivery of nutrients to the distal small intestine, thereby enhancing the release of hormones such as glucagon-like peptide-1 (GLP-1). The latter theory contends that exclusion of the proximal small intestine reduces or suppresses the secretion of anti-incretin hormones, leading to improvement of blood glucose control as a consequence. In fact, increased GLP-1 plasma levels stimulate insulin secretion and suppress glucagon secretion, thereby improving glucose metabolism. Recent studies have shown that improved intestinal gluconeogenesis may also be involved in the amelioration of glucose homoeostasis following RYGB. Although no large trials have specifically addressed the effects of bariatric surgery on the remission or reversal of type 2 diabetes independent of weight loss and/or caloric restriction, there are sufficient data in the literature to support the idea that this type of surgery--specifically, RYGB and BPD--can lead to early improvement of glucose control independent of weight loss. Topics: Bariatric Surgery; Blood Glucose; Caloric Restriction; Diabetes Mellitus, Type 2; Gastric Bypass; Glucagon-Like Peptide 1; Gluconeogenesis; Humans; Insulin; Insulin Secretion; Intestine, Small; Obesity, Morbid; Stomach; Weight Loss | 2009 |
Bariatric surgery in patients with type 2 diabetes: benefits, risks, indications and perspectives.
Obesity plays a key role in the pathophysiology of type 2 diabetes (T2DM), and weight loss is a major objective, although difficult to achieve with medical treatments. Bariatric surgery has proven its efficacy in obtaining marked and sustained weight loss, and is also associated with a significant improvement in glucose control and even diabetes remission. Roux-en-Y gastric bypass appears to be more effective in diabetic patients than the restrictive gastroplasty procedure. This may be explained not only by greater weight reduction, but also by specific hormonal changes. Indeed, increased levels of glucagon-like peptide-1 (GLP-1) and glucose-dependent insulinotropic polypeptide (GIP) may lead to improved beta-cell function and insulin secretion as well as reduced insulin resistance associated with weight loss. The presence of T2DM in obese individuals is a further argument to propose bariatric surgery, and even more so when diabetes is difficult to manage by medical means and other weight-related complications may occur. Bariatric surgery is associated with a better cardiovascular prognosis and reduced mortality, even though acute and long-term complications are present. The observation that surgical rerouting of nutrients triggers changes in the release of incretin hormones that, in turn, ameliorate the diabetic state in the absence of weight loss has led to the recent development of innovative surgical procedures. Thus, bariatric surgery may be said to be progressing towards so-called 'metabolic surgery', which merits further evaluation in patients with T2DM within a multidisciplinary approach that involves both surgeons and endocrinologists. Topics: Bariatric Surgery; Diabetes Mellitus, Type 2; Gastric Bypass; Gastroplasty; Glucagon-Like Peptide 1; Humans; Insulin; Insulin Resistance; Insulin Secretion; Obesity, Morbid; Prognosis; Risk Factors; Weight Loss | 2009 |
The perspectives of adjunctive drugs usage in the treatment of glucose metabolism disturbances in adolescent patients.
Tightening of the diabetes control criteria in the last few years induces searches for adjunctive drugs to reinforce the basic treatment typical for the specific type of the disease. These agents are meant to stimulate insulin secretion, increase insulin sensitivity or inhibit the antagonists of the hormone. Up till now that kind of studies included adults, mainly with type 2 diabetes. Nowadays, however, the increasing number of research focuses on type 1 diabetic patients. The attempts to introduce this type of treatment in adolescent patients encounter many limitations, mostly of formal nature due to drug registration requirements. Nevertheless, more and more studies point at the efficacy of these agents and the possibility of their usage also in adolescents with different types of diabetes. Topics: Adipose Tissue; Adolescent; Adult; Amyloid; Diabetes Mellitus, Type 1; Diabetes Mellitus, Type 2; Female; Ghrelin; Glucagon; Glucagon-Like Peptide 1; Humans; Hypoglycemic Agents; Islet Amyloid Polypeptide; Male; Receptors, Cannabinoid | 2009 |
The role of incretin on diabetes mellitus.
Beta cell dysfunction in type-2 diabetes mellitus holds an important role not just on its pathogenesis, but also on the progression of the disease. Until now, diabetes treatment cannot restore the reduced function of pancreatic beta cell. McIntyre et al stated that there is a factor from the intestine which stimulates insulin secretion as a response on glucose.This factor is known as incretin. It is a hormone which is released by the intestine due to ingested food especially those which contain carbohydrate and fat. Currently, there are 2 types of incretin hormones which have been identified, i.e.Glucose dependent insulinotropic polypeptide (GIP) and Glucagon like peptide-1 (GLP-1). These two hormones act by triggering insulin release immediately after food ingestion, inhibiting glucagon secretion, delaying stomach emptying, and suppressing hunger sensation. Several in vitro studies have demonstrated that these two incretin hormones may increase the proliferation of pancreatic beta cell.There is a decrease of GIP function and GLP-1 amount in type-2 diabetes mellitus; thus the attempt to increase both incretin hormones - in this case by using GLP-1 agonist and DPP-IV inhibitor - is one of treatment modalities to control the glucose blood level, either as a monotherapy or a combination therapy. Currently, there are two approaches of incretin utilization as one of type-2 diabetes mellitus treatment, which is the utilization of incretin mimetic/agonist and DPP-IV inhibitor. Topics: Diabetes Mellitus, Type 2; Dipeptidyl Peptidase 4; Dipeptidyl-Peptidase IV Inhibitors; Disease Progression; Gastric Inhibitory Polypeptide; Glucagon-Like Peptide 1; Humans; Incretins; Insulin-Secreting Cells | 2009 |
[New drugs; exenatide and sitagliptin].
Incretin hormones, secreted upon food intake, play an important role in the regulation of blood glucose levels. In type 2 diabetes mellitus, the incretin response is decreased. Substitution of incretin is a novel pharmacological target which restores postprandial glucose homeostasis. Exenatide is a mimetic of the incretin glucagon-like peptide-I (GLP-I). Sitagliptin is an inhibitor of the enzyme dipeptidyl peptidase 4 (DPP-4), which breaks down GLP-I. Both drugs increase the GLP-I concentration, thereby improving insulin secretion from pancreatic p cells, restoring glycaemic control, preventing beta cell destruction, delaying gastric emptying, and reducing food intake. Topics: Blood Glucose; Diabetes Mellitus, Type 2; Dipeptidyl-Peptidase IV Inhibitors; Energy Intake; Exenatide; Gastric Emptying; Glucagon-Like Peptide 1; Humans; Hypoglycemic Agents; Insulin; Insulin Secretion; Peptides; Pyrazines; Sitagliptin Phosphate; Triazoles; Venoms | 2008 |
New treatments for type 2 diabetes mellitus: combined therapy with sitagliptin.
Sitagliptin is a highly selective oral dipeptidyl peptidase-4 inhibitor. This drug increases the plasma concentration of active glucagon like peptide-1 (GLP-1) and glucose-dependent insulinotropic peptide. These two hormones then simulate the secretion of insulin in a glucose-dependent manner and inhibit glucagon secretion, thus reducing circulating glucose levels. In animal models, GLP-1 increases beta-cell mass.. To review the efficacy and safety of sitagliptin in combined therapies (as add on or initial combination treatment) in type 2 diabetes.. A Medline search on published clinical trials involving sitagliptin in combined therapies was performed; additional information from published papers and abstracts to congresses on preclinical and basic science issues was also included to support the mechanistic rationale of combinations.. In humans sitagliptin administration reduces fasting and postprandial glucose and A1c levels. Sitagliptin is as effective as glipizide (close to 0.7% mean A1c reduction), but has fewer hypoglycemic events than other oral insulin secretagogues. Since metformin reduces hepatic glucose production and increases GLP-1 release, combined therapy with sitagliptin becomes complementary and has been shown to have important additive effects. Sitagliptin combined with pioglitazone resulted in improved metabolic control when compared with pioglitazone plus placebo. Combined administration with insulin requires further studies. The weight neutral effect of sitagliptin, its glucose-dependent action (lower risk of hypoglycemia), the beneficial effects on beta-cell function and its eventual protective action on beta-cell mass makes it an excellent option for monotherapy or combined with metformin, glitazones or even sulfonylurea. Topics: Clinical Trials as Topic; Diabetes Mellitus, Type 2; Dipeptidyl Peptidase 4; Dipeptidyl-Peptidase IV Inhibitors; Drug Therapy, Combination; Gastric Inhibitory Polypeptide; Glucagon-Like Peptide 1; Humans; Hypoglycemic Agents; Incretins; Peptide Fragments; Pyrazines; Sitagliptin Phosphate; Treatment Outcome; Triazoles | 2008 |
Exenatide: its position in the treatment of type 2 diabetes.
Type 2 diabetic patients who have not achieved adequate glucose control at the maximum tolerated doses of their oral therapies currently have no alternative other than insulin. A new approach has been developed, using the glucoregulatory properties of the intestinal incretin hormone glucagon-like peptide-1 (GLP-1). This has resulted in the development of a new therapeutic class, the incretin mimetics, of which exenatide is the first to have been approved. Exenatide can bind to the endogenous receptors of GLP-1 and mimic its glucoregulatory actions. It improves glycemic control by acting on the key organs involved in glucose homeostasis: it stimulates insulin secretion and suppresses glucagon secretion in a glucose-dependent way, slows gastric emptying and reduces food intake. It consequently produces significant reductions in fasting and postprandial hyperglycemia. Various clinical studies, both versus placebo and versus insulin, have shown a significant decrease in HbA1c levels (of about 1%), accompanied by weight loss, in patients treated with exenatide. Exenatide efficacy is sustained and all the studies have shown a comparable tolerance profile. The most frequently reported adverse effects were nausea and hypoglycemia when the patient received concomitant sulfonylurea therapy. The aim of this article is to summarize main clinical data on exenatide and to discuss its position in current therapeutic strategy. Topics: Clinical Trials as Topic; Diabetes Mellitus, Type 2; Exenatide; Glucagon; Glucagon-Like Peptide 1; Humans; Hypoglycemic Agents; Insulin; Peptides; Venoms | 2008 |
Glucagon-like peptide receptor agonists and dipeptidyl peptidase-4 inhibitors in the treatment of diabetes: a review of clinical trials.
To discuss the virtues and shortcomings of the glucagon-like peptide-1 receptor agonists and the dipeptidyl peptidase-4 inhibitors in the treatment of type 2 diabetes.. The injectable glucagon-like peptide-1 receptor agonists exenatide significantly improves glycaemic control, with average reductions in haemoglobin A1c of about 1.0%, fasting plasma glucose of about 1.4 mmol/l, and causes a weight loss of approximately 2-3 kg after 30 weeks of treatment in patients with type 2 diabetes. The adverse effects are transient nausea and vomiting. The long-acting glucagon-like peptide-1 receptor agonists liraglutide and exenatide long-acting release reduce haemoglobin A1c by about 1.0-2.0% and have fewer gastrointestinal side-effects. The orally available dipeptidyl peptidase-4 inhibitors, that is sitagliptin and vildagliptin reduce haemoglobin A1c by 0.5-1.0%, are weight neutral and without gastrointestinal side-effects.. The benefits and position of the glucagon-like peptide-1 analogues and the dipeptidyl peptidase-4 inhibitors in the diabetes treatment algorithm will be clarified when we have long-term trials with hard cardiovascular endpoints and data illustrating the effects on the progression of type 2 diabetes. Topics: Adamantane; Clinical Trials as Topic; Diabetes Mellitus, Type 2; Dipeptidyl Peptidase 4; Dipeptidyl-Peptidase IV Inhibitors; Exenatide; Glucagon-Like Peptide 1; Glucagon-Like Peptide-1 Receptor; Glucagon-Like Peptides; Humans; Hypoglycemic Agents; Liraglutide; Nitriles; Peptides; Pyrazines; Pyrrolidines; Receptors, Glucagon; Sitagliptin Phosphate; Triazoles; Venoms; Vildagliptin | 2008 |
Treating diabetes with incretin hormones - clinical experience.
Type 2 diabetes is a progressive disease. The glucose control of persons with type 2 diabetes usually worsens over time. As seen in the UKPDS patients on one oral medication often fail. Treatment of this chronic, progressive disease usually requires multiple medications often in combination with insulin. However, despite the availability of many medications, the majority of people with type 2 diabetes are unable to maintain long-term glycemic control. The high prevalence of obesity compounds this problem as it may worsen hyperglycemia and insulin resistance. Ineffective implementation of existing pharmacotherapy is a significant factor contributing to suboptimal care. The efficacy of available therapies diminishes as the disease progresses because of a steady decline in pancreatic beta cell function. Innovative approaches to treatment are required and new agents are constantly being sought. Recent research has provided new insight to the role of alpha cells, glucagon and incretin hormones in the pathogenesis of type 2 diabetes. Recently several compounds became available for treatment. This is a review of incretin mimetics and enhancers and their clinical utility. Topics: Amino Acid Sequence; Child; Diabetes Mellitus, Type 2; Dipeptidyl Peptidase 4; Dipeptidyl-Peptidase IV Inhibitors; Glucagon-Like Peptide 1; Humans; Hypoglycemic Agents; Incretins; Molecular Sequence Data | 2008 |
Novel combination treatment of type 2 diabetes DPP-4 inhibition + metformin.
Inhibition of dipeptidyl peptidase-4 (DPP-4) as a novel therapy for type 2 diabetes is based on prevention of the inactivation process of bioactive peptides, the most important in the context of treatment of diabetes of which is glucagon-like peptide-1 (GLP-1). Most clinical experience with DPP-4 inhibition is based on vildagliptin (GalvusR, Novartis) and sitagliptin (JanuviaR, Merck). These compounds improve glycemic control both in monotherapy and in combination with other oral hyperglycemic agents. Both have also been shown to efficiently improve glycemic control when added to ongoing metformin therapy in patients with inadequate glycemic control. Under that condition, they reduce HbA1C levels by 0.65%-1.1% (baseline HbA1C 7.2-8.7%) in studies up to 52 weeks of duration in combination versus continuous therapy with metformin alone. Sitagliptin has also been examined in initial combination therapy with metformin have; HbA1 was reduced by this combination by 2.1% (baseline HbA1C 8.8%) after 24 weeks of treatment. Both fasting and prandial glucose are reduced by DPP-4 inhibition in combination with metformin in association with improvement of insulin secretion and insulin resistance and increase in concentrations of active GLP-1. The combination of DPP-4 inhibition and metformin has been shown to be highly tolerable with very low risk of hypoglycemia. Hence, DPP-4 inhibition in combination with metformin is an efficient, safe and tolerable combination therapy for type 2 diabetes. Topics: Adamantane; Blood Glucose; Diabetes Mellitus, Type 2; Dipeptidyl Peptidase 4; Dipeptidyl-Peptidase IV Inhibitors; Drug Therapy, Combination; Glucagon-Like Peptide 1; Glycated Hemoglobin; Humans; Hypoglycemic Agents; Insulin; Islets of Langerhans; Metformin; Nitriles; Pyrazines; Pyrrolidines; Sitagliptin Phosphate; Time Factors; Treatment Outcome; Triazoles; Vildagliptin | 2008 |
Beyond insulin replacement: addressing the additional needs of the diabetes patient.
The management of type 2 diabetes mellitus (T2DM) typically focuses on correcting dysglycaemia to reduce risk for microvascular and macrovascular complications, possibly by reducing glucose-mediated oxidative stress. However, other cardiometabolic risk factors, including abdominal obesity and dyslipidaemia are often overlooked in the quest for perfect glucose control. The currently used antidiabetic agents, including insulin, metformin, sulphonylureas and thiazolidinediones, have limited efficacy on these risk factors. A number of new therapeutic agents are undergoing clinical development, including glucagon-like peptide 1 mimetics (exenatide and liraglutide) and dipeptidyl peptidase 4 inhibitors (sitagliptin and vildagliptin), which target the incretin system, and the cannabinoid-1 receptor antagonists (rimonabant), which target the endocannabinoid system, may hold some promise for meeting these unmet needs. In this review, the clinical properties of these agents and potential treatment pathways to best use these agents are discussed for improving the management of T2DM and cardiovascular risk. Topics: Cannabinoid Receptor Antagonists; Cardiovascular Diseases; Diabetes Mellitus, Type 2; Dipeptidyl-Peptidase IV Inhibitors; Glucagon-Like Peptide 1; Humans; Hypoglycemic Agents; Obesity; Weight Gain | 2008 |
From the bench to the bedside: dipeptidyl peptidase IV inhibitors, a new class of oral antihyperglycemic agents.
New therapeutic agents are needed to combat the ever-increasing prevalence of diabetes. The two incretins glucagon-like peptide-1 (7-36) (GLP-1(7-36)) amide and glucose-dependent insulinotropic peptide (GIP) are released from the small intestine in response to the ingestion of nutrients and regulate glucose homeostasis in a glucose-dependent fashion; however, the action of both incretins is terminated by the rapid N-terminal cleavage of two amino acid residues of GLP-1 and GIP by dipeptidyl peptidase-IV (DPP-IV). The preservation of active GLP-1 and GIP by inhibiting DPP-IV activity is an attractive strategy for the treatment of diabetes in patients who exhibit a reduced incretin response. This strategy has resulted in the launch of two DPP-IV inhibitor drugs; sitagliptin in North America, several European territories, and various other countries, and vildagliptin in the EU as well as various countries. This article provides an overview of the recent advances in and the lessons learned from the design of potent and selective small-molecule inhibitors of DPP-IV for the treatment of type 2 diabetes. Topics: Adamantane; Administration, Oral; Animals; Diabetes Mellitus, Type 2; Dipeptidyl Peptidase 4; Dipeptidyl-Peptidase IV Inhibitors; Drug Design; Gastric Inhibitory Polypeptide; Glucagon-Like Peptide 1; Humans; Hypoglycemic Agents; Models, Molecular; Molecular Structure; Nitriles; Protein Conformation; Pyrazines; Pyrrolidines; Sitagliptin Phosphate; Structure-Activity Relationship; Treatment Outcome; Triazoles; Vildagliptin | 2008 |
Replacing SUs with incretin-based therapies for type 2 diabetes mellitus: challenges and feasibility.
Type 2 diabetes mellitus (T2DM) is a progressive disease characterized by insulin resistance, a steady decline in glucose-induced insulin secretion (most likely caused by a progressive decrease in functional beta-cell mass), and inappropriately regulated glucagon secretion; in combination, these effects result in hyperglycemia. In 1958, sulfonylurea (SU) was introduced to the market as one of the first oral treatments for T2DM. Since then, the ability of SU to stimulate the release of insulin from pancreatic beta-cells by the closure of ATP-sensitive K+-channels has been employed as one of the most widespread treatment options for T2DM. However, SUs are associated with weight gain and a risk of hypoglycemia, and the one-track antidiabetic mechanism of SUs often results in patients being treated with additional antidiabetic drugs. In recent studies, SU has proven to be associated with increased beta-cell apoptosis, suggesting that SU may actually accelerate the progressive decrease in beta-cell mass, thereby promoting the need for insulin replacement. In contrast, the newly developed incretin-based therapies for T2DM employ the beta-cell-preserving properties of incretin hormones - glucagon-like peptide 1 (GLP-1) and glucose-dependent insulinotropic polypeptide (GIP). More importantly, incretin-based therapies potentiate glucose-stimulated insulin secretion and may restore reduced glucose-induced insulin secretion in T2DM. Furthermore, the insulinotropic effects of GLP-1 and GIP are glucose-dependent, reducing the risk of hypoglycemia. GLP-1 inhibits glucagon secretion and decreases gastrointestinal motility, in turn reducing food intake and body weight. This feature review focuses on the challenges and feasibilities of replacing SU with incretin-based therapy in patients with T2DM. Topics: Diabetes Mellitus, Type 2; Gastric Inhibitory Polypeptide; Glucagon-Like Peptide 1; Humans; Hypoglycemic Agents; Incretins; Molecular Mimicry; Sulfonylurea Compounds | 2008 |
Long-acting GLP-1 analogs for the treatment of type 2 diabetes mellitus.
Type 2 diabetes mellitus is characterized by insulin resistance, impaired glucose-induced insulin secretion, and inappropriately elevated glucagon levels which eventually result in hyperglycemia. The currently available treatment modalities for type 2 diabetes are often unsatisfactory in getting patients to glycemic goals, even when used in combination, and therefore many patients develop microvascular and macrovascular diabetic complications. Additionally, these treatment modalities are often limited by inconvenient dosage regimens and safety and tolerability issues, the latter including hypoglycemia, bodyweight gain, edema, and gastrointestinal intolerance. There is, therefore, a need for new and more efficacious agents, targeting not only treatment, but also prevention of the disease, its progression, and its associated complications. Recently, an entirely new therapeutic option for the treatment of type 2 diabetes has become available in the US (since October 2005) and in Europe (since May 2007): the incretin-based therapies. The incretin-based therapies fall into two different classes: (i) incretin mimetics, i.e. injectable peptide preparations with actions similar to the natural incretin hormones; and (ii) the incretin enhancers, i.e. orally available agents that inhibit the degradation of the incretin hormones in the body and thereby increase their plasma levels and biologic actions. This article focuses on the incretin mimetics and outlines the scientific basis for the development of glucagon-like peptide-1 (GLP-1) analogs, reviews clinical experience gained so far, and discusses future expectations for long-acting forms of GLP-1 analogs. Topics: Delayed-Action Preparations; Diabetes Mellitus, Type 2; Exenatide; Glucagon-Like Peptide 1; Humans; Hypoglycemic Agents; Liraglutide; Peptides; Venoms | 2008 |
Incretin-based therapies in type 2 diabetes mellitus.
Glucagon-like peptide-1 (GLP-1) and glucose-dependent insulinotropic polypeptide are incretins secreted from enteroendocrine cells postprandially in part to regulate glucose homeostasis. Dysregulation of these hormones is evident in type 2 diabetes mellitus (T2DM). Two new drugs, exenatide (GLP-1 mimetic) and sitagliptin [dipeptidyl peptidase (DPP) 4 inhibitor], have been approved by regulatory agencies for treating T2DM. Liraglutide (GLP-1 mimetic) and vildagliptin (DPP 4 inhibitor) are expected to arrive on the market soon.. The background of incretin-based therapy and selected clinical trials of these four drugs are reviewed. A MEDLINE search was conducted for published articles using the key words incretin, glucose-dependent insulinotropic polypeptide, GLP-1, exendin-4, exenatide, DPP 4, liraglutide, sitagliptin, and vildagliptin.. Exenatide and liraglutide are injection based. Three-year follow-up data on exenatide showed a sustained weight loss and glycosylated hemoglobin (HbA(1c)) reduction of 1%. Nausea and vomiting are common. Results from phase 3 studies are pending on liraglutide. Sitagliptin and vildagliptin are orally active. In 24-wk studies, sitagliptin reduces HbA(1c) by 0.6-0.8% as monotherapy, 1.8% as initial combination therapy with metformin, and 0.7% as add-on therapy to metformin. Vildagliptin monotherapy lowered HbA(1c) by 1.0-1.4% after 24 wk. Their major side effects are urinary tract and nasopharyngeal infections and headaches. Exenatide and liraglutide cause weight loss, whereas sitagliptin and vildagliptin do not.. The availability of GLP-1 mimetics and DPP 4 inhibitors has increased our armamentarium for treating T2DM. Unresolved issues such as the effects of GLP-1 mimetics and DPP 4 inhibitors on beta-cell mass, the mechanism by which GLP-1 mimetics lowers glucagon levels, and exactly how DPP 4 inhibitors lead to a decline in plasma glucose levels without an increase in insulin secretion, need further research. Topics: Amino Acid Sequence; Diabetes Mellitus, Type 2; Dipeptidyl Peptidase 4; Dipeptidyl-Peptidase IV Inhibitors; Enzyme Inhibitors; Glucagon-Like Peptide 1; Humans; Hypoglycemic Agents; Incretins; Models, Biological; Molecular Sequence Data | 2008 |
[Exenatid and its position as antidiabetic drug in the treatment of type 2 diabetes mellitus].
'Incretin effect' refers to increased insulin response to oral glucose as compared to i.v. glucose response. Incretin mimetics are a new class of antidiabetic drugs lowering hyperglycaemia. Incretin mimetics mimic the natural human hormones called 'incretins' with blood glucose regulating action. Exenatide is a synthetic analogue GLP-1 which is resistant to enzymatic degradation by DPP IV. Subcutaneously administered exenatide stimulates insulin secretion, suppresses glucagon secretion, slows down stomach evacuation and reduces the weight. Its administration is safe and the most frequent side effect is mild nausea. Topics: Animals; Blood Glucose; Diabetes Mellitus, Type 2; Exenatide; Glucagon-Like Peptide 1; Glycated Hemoglobin; Humans; Hypoglycemic Agents; Incretins; Peptides; Venoms | 2008 |
Physiology of incretins (GIP and GLP-1) and abnormalities in type 2 diabetes.
Incretin hormones are defined as intestinal hormones released in response to nutrient ingestion, which potentiate the glucose-induced insulin response. In humans, the incretin effect is mainly caused by two peptide hormones, glucose-dependent insulin releasing polypeptide (GIP), and glucagon-like peptide-1 (GLP-1). GIP is secreted by K cells from the upper small intestine while GLP-1 is mainly produced in the enteroendocrine L cells located in the distal intestine. Their effect is mediated through their binding with specific receptors, though part of their biological action may also involve neural modulation. GIP and GLP-1 are both rapidly degraded into inactive metabolites by the enzyme dipeptidyl-peptidase-IV (DPP-IV). In addition to its effects on insulin secretion, GLP-1 exerts other significant actions, including stimulation of insulin biosynthesis, inhibition of glucagon secretion, inhibition of gastric emptying and acid secretion, reduction of food intake, and trophic effects on the pancreas. As the insulinotropic action of GLP-1 is preserved in type 2 diabetic patients, this peptide was likely to be developed as a therapeutic agent for this disease. Topics: Animals; Diabetes Mellitus, Type 2; Gastric Inhibitory Polypeptide; Glucagon-Like Peptide 1; Humans; Incretins; Insulin; Insulin Secretion; Insulin-Secreting Cells; Killer Cells, Natural; Proglucagon | 2008 |
Therapeutic approach of type 2 diabetes mellitus with GLP-1 based therapies.
The goal of this review is to think about how to incorporate the GLP-1 based agents, represented by the dipeptidyl peptidase-4 (DPP-4) inhibitors or the glucagon-like peptide-1 (GLP-1) analogs, in the guidelines for the management of type 2 diabetes (T2DM). Orally administered DPP-4 inhibitors, such as sitagliptin and vildagliptin, reduce HbA(1c) (absolute values) by 0.5-1.1% (5 to 12%, relative values), with few adverse events and no weight gain. The sub-cutaneous injected GLP-1 analogs show larger reductions in HbA(1c) (0.8-1.7%, absolute values; 9.4-20.0%, relative values), associated with weight loss (1.75-3.8 kg); their most common adverse events are gastrointestinal symptoms which contribute to a substantial treatment interruption. If they do not challenge the use of metformin as the initial therapy of T2DM, several studies argue in favour of the use of DPP-4 inhibitors, either in combination with metformin as the initial treatment or, in add-on therapy to metformin. The advantages of this combination over others currently used are reviewed. In patients not tolerating metformin, DPP-4 inhibitors seem to be an excellent alternative as a monotherapy. As long as oral triple therapy is concerned, the choice for the association metformin + thiazolidinedione + incretin-based drug, has again several theoretical advantages against other triple therapy combinations. Finally, in patients with T2DM inadequately controlled with maximal tolerated oral multi-therapies, GLP-1 agonists are a good alternative to insulin therapy, allowing reaching a better glycaemic control together with a weight loss. However, for patients who do not tolerate GLP-1 agonist treatment, and for those not reaching the HbA(1c) target, insulin will remain necessary, allowing getting a better metabolic control, with few adverse events. The long-term effect of these new agents on glycaemic control has not yet been established, and their potential impact on beta-cell function in humans remains an area of active investigation. So, further studies are needed and will allow progressively refining the use of incretin-based agents in T2DM treatment strategy. Topics: Administration, Oral; Clinical Trials as Topic; Diabetes Mellitus, Type 2; Glucagon-Like Peptide 1; Humans; Hypoglycemic Agents; Metformin; Placebos; Sulfonylurea Compounds; Thiazolidinediones | 2008 |
DPP4 inhibitors: a new approach in diabetes treatment.
The role of dipeptidyl peptidase-IV (DPP4) as both a regulatory enzyme and a signalling factor has been evaluated and described in many studies. DPP4 inhibition results in increased blood concentration of the incretin hormones glucagon-like peptide-1 (GLP-1) and gastric inhibitory polypeptide (GIP). This causes an increase in glucose-dependent stimulation of insulin secretion, resulting in a lowering of blood glucose levels. Recent studies have shown that DPP4 inhibitors can induce a significant reduction in glycosylated haemoglobin (HbA(1c)) levels, either as monotherapy or as a combination with other antidiabetic agents. Research has also demonstrated that DPP4 inhibitors portray a very low risk of hypoglycaemia development. This review article focuses on the two leading agents of this category (sitagliptin and vildagliptin), providing an overview of their function along with the latest data regarding their clinical efficacy as antidiabetic agents. Topics: Adamantane; Animals; Blood Glucose; Diabetes Mellitus, Type 2; Dipeptidyl-Peptidase IV Inhibitors; Drug Therapy, Combination; Gastric Inhibitory Polypeptide; Glucagon-Like Peptide 1; Glycated Hemoglobin; Humans; Hypoglycemic Agents; Incretins; Insulin; Insulin Secretion; Nitriles; Pyrazines; Pyrrolidines; Sitagliptin Phosphate; Triazoles; Vildagliptin | 2008 |
Managing postprandial glucose levels in patients with diabetes.
Topics: Blood Glucose; Cardiovascular Diseases; Diabetes Mellitus, Type 2; Dipeptidyl Peptidase 4; Dipeptidyl-Peptidase IV Inhibitors; Glucagon-Like Peptide 1; Glycated Hemoglobin; Humans; Hypoglycemic Agents; Incretins; Insulin; Insulin Secretion; Insulin-Secreting Cells; Postprandial Period | 2008 |
Overview of glucagon-like peptide-1 analogs and dipeptidyl peptidase-4 inhibitors for type 2 diabetes.
Impairment of incretin activity is now recognized as integral to the metabolic derangement underlying type 2 diabetes. Glucoregulatory agents that target the incretin system have recently been developed, and the place of these drugs in the treatment of type 2 diabetes can be assessed based on a growing body of clinical data.. A PubMed search was conducted to identify clinical studies of incretin therapies in type 2 diabetes. Article reference lists were also searched for relevant information, and supplemental material such as conference abstracts, drug prescribing information, and treatment guidelines were included as appropriate.. Two classes of therapies target the incretin system. The first, glucagon-like peptide-1 (GLP-1) agonists (exemplified by exenatide and liraglutide), have demonstrated considerable efficacy in clinical trials, reducing hemoglobin A1c (HbA1c) by up to 1.3%, decreasing fasting and postprandial glucose concentrations, reducing weight by approximately 3.0 kg, and improving cardiovascular risk factors. The second class, the dipeptidyl peptidase-4 inhibitors (such as sitagliptin and vildagliptin) rely on production of endogenous GLP-1 and act by reducing its turnover. The dipeptidyl peptidase-4 (DPP-4) inhibitors produce modest reductions in HbA1c (< 1%) compared with GLP-1 agonists and are generally weight-neutral. Neither GLP-1 agonists nor DPP-4 inhibitors cause hypoglycemia unless used with other agents known to increase risk.. GLP-1 agonists and DPP-4 inhibitors provide a valuable new treatment option for patients with type 2 diabetes and may be associated with a wider range of therapeutic benefits than older drugs. Topics: Clinical Trials as Topic; Diabetes Mellitus, Type 2; Dipeptidyl-Peptidase IV Inhibitors; Glucagon-Like Peptide 1; Humans; PubMed; Treatment Outcome | 2008 |
Janumet: a combination product suitable for use in patients with Type 2 diabetes.
Inhibition of the enzyme dipeptidyl peptidase-4 represents the latest pharmacologic intervention to become available to assist patients with Type 2 diabetes to achieve glycemic control. A combination tablet of sitagliptin (Januvia) and metformin HCl (Glucophage) is now available from Merck (Janumet). The FDA has approved this drug for use in patients who are not adequately controlled by taking either sitagliptin or metformin HCl alone or for patients who are at present taking both simultaneously. Sitagliptin has been shown to be safe and effective at 100 mg daily doses. When given in combination with metformin the effect on glycemic control is thought to be complementary and possibly additive. Topics: Diabetes Mellitus, Type 2; Dipeptidyl-Peptidase IV Inhibitors; Drug Combinations; Drug Interactions; Glucagon-Like Peptide 1; Humans; Hypoglycemic Agents; Metformin; Pyrazines; Sitagliptin Phosphate; Sitagliptin Phosphate, Metformin Hydrochloride Drug Combination; Triazoles | 2008 |
Incretin mimetics and dipeptidyl peptidase-4 inhibitors: innovative treatment therapies for type 2 diabetes.
The prevalence of diabetes and impaired glucose tolerance is predicted to dramatically increase over the next two decades. Clinical therapies for type 2 diabetes mellitus (T2DM) have traditionally included lifestyle modification, oral anti-diabetic agents, and ultimately insulin initiation. In this report, we review the clinical trial results of two innovative T2DM treatment therapies that are based on the glucoregulatory effects of incretin hormones. Incretin mimetics are peptide drugs that mimic several of the actions of glucagon-like peptide-1 (GLP-1) and have been shown to lower glycated hemoglobin (A1C) levels in patients with T2DM. Additionally, incretin mimetics lower postprandial and fasting glucose, suppress elevated glucagon release, and are associated with progressive weight reduction. Dipeptidyl peptidase-4 (DPP-4) inhibitors increase endogenous GLP-1 levels by inhibiting the enzymatic degradation of GLP-1. Clinical studies in patients with T2DM have shown that DPP-4 inhibitors reduce elevated A1C, lower postprandial and fasting glucose, suppress glucagon release, and are weight neutral. Collectively, these new drugs, given in combination with other antidiabetic agents, such as metformin, sulfonylureas, and/or thiazolidinediones, can help restore glucose homeostasis in poorly controlled patients with T2DM. Topics: Adamantane; Blood Glucose; Body Weight; Diabetes Mellitus, Type 2; Dipeptidyl-Peptidase IV Inhibitors; Exenatide; Fasting; Glucagon-Like Peptide 1; Glycated Hemoglobin; Humans; Hypoglycemic Agents; Incretins; Nitriles; Peptides; Postprandial Period; Pyrazines; Pyrrolidines; Sitagliptin Phosphate; Triazoles; Venoms; Vildagliptin | 2008 |
Hormone-based therapies in the regulation of fuel metabolism and body weight.
The integrated central actions of hormones secreted from pancreatic islets, the gut and adipocytes regulate both energy homeostasis and body weight. Dysregulation in these neurohormonal pathways probably contributes to pathogenesis of obesity and type 2 diabetes.. To examine hormone-based therapies targeting these interrelated pathways as potential treatments for obesity and diabetes.. Preclinical and clinical data on therapies based on hormones secreted from the pancreas (glucagon, insulin, amylin and pancreatic polypeptide), gut (glucagon-like peptide-1, glucose dependent insulinotropic polypeptide, cholecystokinin and peptide YY) and adipose tissue (leptin and adiponectin) as potential treatments for diabetes and obesity are reviewed.. In diabetes, hormone-based treatments have translated into new clinical platforms including insulin analogs, the GLP-1-like peptide receptor agonist exenatide and amylinomimetic pramlintide, which due to their complex interplay and the progressive nature of diabetes, can be utilized in different settings. Various peptide hormones and agonists/antagonists are currently under investigation as new approaches to treatment of obesity and diabetes. Topics: Adipocytes; Adiponectin; Adipose Tissue; Amyloid; Animals; Body Weight; Diabetes Mellitus, Type 2; Energy Metabolism; Glucagon-Like Peptide 1; Homeostasis; Hormones; Humans; Intestinal Mucosa; Islet Amyloid Polypeptide; Leptin; Mice; Obesity; Pancreas | 2008 |
Future perspectives on glucagon-like peptide-1, diabetes and cardiovascular risk.
Glucagon-like peptide-1 (GLP-1), a gastrointestinal hormone mainly produced in the post-prandial state, reduces blood glucose through the stimulation of insulin secretion and the inhibition of glucagon release. Long-acting GLP-1 receptor agonists, and dipeptidyl-peptidase-4 (DPP-4) inhibitors which increase GLP-1 levels, are used as hypoglycemic treatments in type 2 diabetes. This paper aims at reviewing the potential benefit of those treatments in the prevention of cardiovascular risk in type 2 diabetic patients.. Experimental studies have shown that GLP-1 has several potentially beneficial actions on cardiovascular risk. Some of those, such as protection from myocardial ischemic damage and improvement of cardiac function, have also been demonstrated in humans. However, the equivalence of GLP-1 agonists and DPP-4 inhibitors with GLP-1, with respect to cardiovascular risk profile, cannot be assumed or taken for granted. Drugs of those two classes have been shown to effectively reduce glycated hemoglobin and to have a specific effect on post-prandial glucose; furthermore, they seem to reduce blood pressure and to have some favorable effects on lipid profiles. Additionally, GLP-1 agonists induce weight loss in diabetic patients.. The profile of action of GLP-1 receptor agonists and DPP-4 inhibitors suggests the possibility of an actual reduction in cardiovascular risk, which needs to be confirmed by large long-term clinical trials. Topics: Blood Pressure; Body Weight; Cardiovascular Diseases; Diabetes Mellitus, Type 2; Dipeptidyl Peptidase 4; Dipeptidyl-Peptidase IV Inhibitors; Glucagon-Like Peptide 1; Heart Rate; Humans; Incretins; Insulin Resistance; Myocardial Contraction; Myocardial Ischemia; Risk Factors | 2008 |
Glucagon like peptides-1 modulators as newer target for diabetes.
Diabetes mellitus (DM) has been recognized as a growing world-wide epidemic by many health advocacy groups including the World Health Organization (WHO). DM affects about 6% of the North American population. A recent report estimated that 8.2% of adult population worldwide has impaired glucose tolerance. Current treatment approaches include diet, exercise, and a variety of pharmacological agents including insulin, biguanides, sulfonylureas and thiazolidinediones. New therapies are still needed to control metabolic abnormalities, and also to preserve beta-cell mass and to prevent loss of beta-cell function. In many cases monotherapy gradually fails to improve blood glucose control and combination therapy is employed. The long-term success of these treatments varies substantially. Thus, there is an imperative need for novel therapeutic approaches for glycemic control that can complement existing therapies and possibly attempt to preserve normal physiological response to meal intake. Glucagon-like peptide 1 (GLP-1) is a drug candidate which potentially fulfils these conditions. Glucoregulatory actions of GLP-1 include glucose-dependent enhancement of insulin secretion, inhibition of glucagon secretion, slowing of gastric emptying and reduction of food intake. GLP-1 is rapidly inactivated by amino peptidase, Dipeptidyl Peptidase-IV (DPP-IV) and the utility of DPP-IV inhibitors are also under investigation. There is a recent upsurge in the development of GLP-1 mimetics and DPP-IV inhibitors as potential antidiabetic agents. The present review summarizes the concepts of GLP-1 based therapy for type 2 diabetes and the current preclinical and clinical development in GLP-1 modulators. Topics: Amino Acid Sequence; Animals; Diabetes Mellitus, Type 2; Drug Delivery Systems; Glucagon-Like Peptide 1; Humans; Molecular Sequence Data | 2008 |
[Sitagliptin. DPP-4 inhibitors as a useful extension of oral diabetes therapy?].
Topics: Adamantane; Diabetes Mellitus, Type 2; Dipeptidyl Peptidase 4; Dipeptidyl-Peptidase IV Inhibitors; Enzyme Inhibitors; Glucagon-Like Peptide 1; Glucose; Humans; Hypoglycemic Agents; Incretins; Insulin; Nitriles; Pyrazines; Pyrrolidines; Sitagliptin Phosphate; Triazoles; Vildagliptin | 2008 |
Dipeptidyl peptidase-4 as a new target of action for type 2 diabetes mellitus: a systematic review.
Type 2 diabetes mellitus is a metabolic disease leading to microvascular and macrovascular complications including coronary artery disease and stroke. Management of diabetes has been challenging, particularly in the presence of the enormous prevalence of obesity. In recent years, various inhibitors of the enzyme dipeptidyl peptidase (DPP)-4 have been developed to treat diabetes. The enzyme DPP-4 cleaves incretins, which, among other functions, stimulate insulin and suppresses glucagon. Inhibition of this enzyme results in an increase in the half-life and the sustained physiologic action of incretins, leading to an improvement in hyperglycemia. One such agent, namely sitagliptin (MK-04,310), has been introduced into the United States market, and another agent, vildagliptin (LAF237), is being used in Europe and elsewhere. This article is intended to evaluate the effectiveness of DPP-4 inhibitors as a therapeutic modality for managing type 2 diabetes. The authors conducted a literature search of various databases to identify the clinical trials involving the DPP inhibitors and concluded that the DPP-4 inhibitors, for example, sitagliptin and vildagliptin, are efficacious for managing diabetes as monotherapy or combination therapy. Topics: Adamantane; Animals; Diabetes Mellitus, Type 2; Diabetic Angiopathies; Dipeptidyl-Peptidase IV Inhibitors; Glucagon-Like Peptide 1; Humans; Hypoglycemic Agents; Incretins; Nitriles; Pyrazines; Pyrrolidines; Sitagliptin Phosphate; Triazoles; Vildagliptin | 2008 |
New approaches to treating type 2 diabetes mellitus in the elderly: role of incretin therapies.
The increasing proportion of elderly persons in the global population, and the implications of this trend in terms of increasing rates of chronic diseases such as type 2 diabetes mellitus, continue to be a cause for concern for clinicians and healthcare policy makers. The diagnosis and treatment of type 2 diabetes in the elderly is challenging, as age-related changes alter the clinical presentation of diabetic symptoms. Once type 2 diabetes is diagnosed, the principles of its management are similar to those in younger patients, but with special considerations linked to the increased prevalence of co-morbidities and relative inability to tolerate the adverse effects of medication and hypoglycaemia. In addition, there are many underappreciated factors complicating diabetes care in the elderly, including cognitive disorders, physical disability and geriatric syndromes, such as frailty, urinary incontinence and pain. Available oral antihyperglycaemic drugs include insulin secretagogues (meglitinides and sulfonylureas), biguanides (metformin), alpha-glucosidase inhibitors and thiazolidinediones. Unfortunately, as type 2 diabetes progresses in older persons, polypharmacy intensification is required to achieve adequate glycaemic control with the attendant increased risk of adverse effects as a result of age-related changes in drug metabolism. The recent introduction of the incretins, a group of intestinal peptides that enhance insulin secretion after ingestion of food, as novel oral antihyperglycaemic treatments may prove significant in older persons. The two main categories of incretin therapy currently available are: glucagon-like peptide-1 (GLP-1) analogues and inhibitors of GLP-1 degrading enzyme dipeptidyl peptidase-4 (DPP-4). The present review discusses the effect of aging on metabolic control in elderly patients with type 2 diabetes, the current treatments used to treat this population and some of the more recent advances in the field of geriatric type 2 diabetes. In particular, we highlight the efficacy and safety of GLP-1 and DPP-4 inhibitors, administered as monotherapy or in combination with other oral antihyperglycaemic agents, especially when the relevant clinical trials included older persons. There is strong evidence that use of incretin therapy, in particular, the DPP-4 inhibitors, could offer significant advantages in older persons. Clinical evidence suggests that the DPP-4 inhibitors vildagliptin and sitagliptin are particularly suitable for f Topics: Aged; Diabetes Mellitus, Type 2; Dipeptidyl-Peptidase IV Inhibitors; Female; Glucagon-Like Peptide 1; Humans; Hypoglycemic Agents; Incretins; Male | 2008 |
RD Lawrence Lecture 2008: Targeting GLP-1 release as a potential strategy for the therapy of Type 2 diabetes.
Glucagon-like peptide-1 (GLP-1) and glucose-dependent insulinotropic polypeptide (GIP) are gastrointestinal hormones that play an important role in stimulating postprandial insulin release from pancreatic beta-cells. Agents that either mimic GLP-1 or prevent its degradation are now available for the treatment of Type 2 diabetes, and strategies to enhance endogenous GLP-1 release are under assessment. As intestinal peptides have a range of actions, including appetite regulation and coordination of fat metabolism, harnessing the enteric endocrine system is a promising new field for drug development. Topics: Diabetes Mellitus, Type 2; Gastric Inhibitory Polypeptide; Glucagon-Like Peptide 1; Humans; Incretins; Insulin; Insulin-Secreting Cells | 2008 |
Incretin-based therapies in type 2 diabetes: a review of clinical results.
GLP-1 analogues (incretin mimetics) and DPP-4 inhibitors (incretin enhancers) represent new classes of anti-diabetic agents for the treatment of type 2 diabetes. The efficacy and safety of the incretin mimetic exenatide and of the DPP-4 inhibitors, sitagliptin and vildagliptin, have been clearly demonstrated by a very large number of clinical trials. Efficacy was demonstrated in terms of reduction of HbA1c, fasting and postprandial glucose. Moreover, exenatide showed a favourable effect on weight, while DPP-4 inhibitors were neutral with respect to this outcome. The low rate of hypoglycemic events seen in all studies confirms the glucose dependent action of incretins. Topics: Adamantane; Clinical Trials as Topic; Diabetes Mellitus, Type 2; Dipeptidyl-Peptidase IV Inhibitors; Exenatide; Glucagon-Like Peptide 1; Humans; Incretins; Nitriles; Peptides; Pyrazines; Pyrrolidines; Sitagliptin Phosphate; Triazoles; Venoms; Vildagliptin | 2008 |
The incretins: from the concept to their use in the treatment of type 2 diabetes. Part A: incretins: concept and physiological functions.
This paper briefly reviews the concept of incretins and describes the biological effects of the two incretins identified so far: the glucose-dependent insulinotropic polypeptide (GIP); and the glucagon-like peptide-1 (GLP-1). GIP is released by the Kcells of the duodenum, while GLP-1 is released by the Lcells of the distal ileum, in response to nutrient absorption. GIP and GLP-1 stimulate insulin biosynthesis and insulin secretion in a glucose-dependent manner. In addition, they increase beta-cell mass. GIP has a specific effect on adipose tissue to facilitate the efficient disposal of absorbed fat and, thus, may be involved in the development of obesity. GLP-1 has specific effects on pancreatic alpha cells, the hypothalamus, and gastrointestinal and cardiovascular systems. By inhibiting glucagon secretion and delaying gastric-emptying, GLP-1 plays an important role in glucose homoeostasis and, by inhibiting food intake, prevents the increase in body weight. As the metabolic effects of GIP are blunted in type 2 diabetes, this peptide cannot be used as an efficient therapy for diabetes. In contrast, GLP-1 effects are preserved at high concentrations in type 2 diabetes, making this peptide of great interest for the treatment of diabetes, a topic that will be discussed in the second part of this review. Topics: Adipose Tissue; Body Weight; Diabetes Mellitus, Type 2; Gastric Emptying; Gastric Inhibitory Polypeptide; Glucagon; Glucagon-Like Peptide 1; Glucagon-Like Peptide-1 Receptor; Humans; Incretins; Insulin; Insulin Secretion; Overweight; Receptors, Glucagon | 2008 |
[New avenues for pharmacotherapy of type 2 diabetes mellitus].
Pharmaceutical products reviewed in this paper markedly extend possibilities for the management of DM-2 and create prerequisites for diferential therapy of this disease. Exenatide and DPP-4 inhibitors do not cause hypoglycemia and may be prescribed to subjects in whom this condition may affect the ability to drive or operate machinery (drivers, pilots, etc.). The mechanism of action of DPP-4 inhibitors make them especially suitable for the treatment of early stages of DM-2 when B-cells are still capable of insulin secretion. They can be used at a dose of 100 mg once daily both for monotherapy and in combination with other oral hypoglycemic agents. These drugs are well tolerated by the patients but contraindicated to those with severe renal insuficiency. Exenatid is more eficacious than DPP-4 inhibitors and has advantages over insulin therapy because it does not increase body weight and do not require as frequent blood glucose monitoring. However, it produces side effects. Therefore, the treatment should be started with a low dose of the drug (5 mg subcutaneously twice daily) that can be doubled in 4 weeks. Bearing in mind the mechanism of action of exanatide, it is indicated largely to patients with DM-2 associated with obesity and a moderately elevated HbAlc level. Rimonabant is especially efficient due to its effect on the endocannabioid system of DM-2 patients with obesity, however it has a drawback of frequently producing adverse affects. Topics: Animals; Blood Glucose; Diabetes Mellitus, Type 2; Dipeptidyl Peptidase 4; Dipeptidyl-Peptidase IV Inhibitors; Exenatide; Glucagon-Like Peptide 1; Humans; Hypoglycemic Agents; Insulin; Peptides; Treatment Outcome; Venoms | 2008 |
Incretin-based therapies: a new potential treatment approach to overcome clinical inertia in type 2 diabetes.
Maintaining an adequate metabolic control is still a challenge in many patients with type 2 diabetes. Among the many factors advocated to explain the failure to achieve recommended goals, clinical inertia is increasingly recognised as a primary cause of poor glycaemic control. The existence of a "metabolic memory" strongly supports the adoption of a more aggressive treat-to-target approach, instead of waiting for treatment failure. This approach may be particularly important in the initial phases of the disease, to slow the progressive decline of beta-cell function and improve overall outcomes. The fear of hypoglycaemia and weight gain associated with most of the available treatments are among the main causes of clinical inertia, and strongly affect the attitudes of providers and patients toward therapy intensification. The incretin-based therapies represent a new potential goal-oriented treatment approach. Two classes of incretin-based drugs have been developed: GLP-1 mimetics (exenatide and liraglutide) and DPP-IV inhibitors (sitagliptin and vildagliptin). Incretino-mimetics have a peculiar mechanism of action that is associated with lack of hypoglycaemia and weight loss or neutrality; these characteristics may facilitate therapy intensification and help to attain established goals. Furthermore, they can induce benefits in terms of post-prandial hyperglicemia control and beta-cell function preservation. An early use of this class of drugs may show a positive impact on the disease progression and a delay in the need of insulin injections. Topics: Adamantane; Diabetes Mellitus, Type 2; Dipeptidyl-Peptidase IV Inhibitors; Exenatide; Glucagon-Like Peptide 1; Glycated Hemoglobin; Humans; Hypoglycemia; Hypoglycemic Agents; Incretins; Liraglutide; Nitriles; Peptides; Pyrazines; Pyrrolidines; Randomized Controlled Trials as Topic; Sitagliptin Phosphate; Triazoles; Venoms; Vildagliptin | 2008 |
Current and emerging therapies: an overview of incretin-based therapy in the management of type 2 diabetes.
Topics: Administration, Oral; Diabetes Mellitus, Type 2; Dipeptidyl-Peptidase IV Inhibitors; Disease Progression; Female; Gastric Inhibitory Polypeptide; Glucagon; Glucagon-Like Peptide 1; Humans; Hypoglycemic Agents; Incretins; Insulin Resistance; Middle Aged; Nurse Practitioners; Patient Selection; Primary Health Care | 2008 |
The entero-insular axis: implications for human metabolism.
Incretins such as glucose-dependent insulinotropic polypeptide (GIP) and glucagon-like peptide 1 (GLP-1) are intestinal hormones that are released in response to ingestion of nutrients, especially carbohydrate. They have a number of important biological effects, which include release of insulin, inhibition of glucagon and somatostatin, maintenance of beta-cell mass, delay of gastric emptying, and inhibition of feeding. These properties allow them to be potentially suitable agents for the treatment of type 2 diabetes (T2D). Incretin receptors are also present in other parts of the body including the brain, where their effects are beginning to be understood and their relevance to disorders of nutrition and ageing are being explored. There is currently a pandemic of obesity and diabetes, and existing treatments are largely inadequate in regard to efficacy as well as their ability to tackle important factors in the pathogenesis of T2D. There is increasing evidence that current treatments do not address the issue of progressive beta-cell failure in T2D. As obesity is the engine that is driving the epidemic of diabetes, it is disappointing that most treatments that succeed in lowering plasma glucose are also associated with weight gain. It is now well established that intensively treated T2D has a better outcome than standard treatment. Consequently, achieving better control of diabetes with lower HbA1c is the goal of optimal treatment. Despite the use of usual therapeutic agents in T2D, often in high doses and as combinations, such as metformin, sulphonylurea, alpha-glycosidase inhibitors, thiazolidinediones and a number of animal and human insulin preparations, optimal control of glycaemia is not achieved. The use of incretins as therapeutic agents offers a new approach to the treatment of T2D. Incretin metabolism is abnormal in T2D, evidenced by a decreased incretin effect, reduction in nutrient-mediated secretion of GIP and GLP-1 in T2D, and resistance to GIP. GLP-1, on the other hand, when administered intravenously in T2D is able to increase insulin secretion and improve glucose homeostasis. As GLP-1 has a very short half-life, due to rapid degradation by the enzyme dipeptidyl peptidase IV (DPPIV), analogues of GIP and GLP-1 that are resistant to the action of DPPIV have been developed and clinical trials have shown their effectiveness. Another novel agent, naturally resistant to DPPIV that is given by subcutaneous injection is a synthetic peptide called Topics: Adipose Tissue; Amino Acid Sequence; Blood Glucose; Brain; Diabetes Mellitus, Type 2; Dipeptidyl Peptidase 4; Dipeptidyl-Peptidase IV Inhibitors; Glucagon-Like Peptide 1; Humans; Hypoglycemic Agents; Incretins; Insulin; Insulin Secretion; Insulin-Secreting Cells; Liver; Molecular Sequence Data; United States | 2008 |
Pathophysiology and treatment of patients with type 2 diabetes exhibiting failure to oral drugs.
It is generally accepted that a poor glycaemic control increases the risk for development of vascular complications in diabetic patients. This advocates for early introduction of insulin treatment in patients with type 2 diabetes exhibiting a secondary failure to oral treatment. This strategy is facilitated by introduction of long-acting insulin glargine and biphasic insulin aspart 70/30. The introduction of Glucagon-like peptide-1 (GLP-1) mimetics and dipeptidyl peptidase 4 (DPP-4) inhibitors in treatment of type 2 diabetes will however, to a large extent, influence therapeutic policy. Thus we suggest that DPP-4 inhibitors or long-acting GLP-1 mimetics will be used as either first-line therapy or as an early addition to metformin. The already generated results in animal and clinical studies suggest that these two classes of antidiabetic drugs may in addition to improving glycaemic control protect islet beta-cell mass and thereby postpone development of a secondary failure. When patients treated with metformin, sulfonylurea (SU), tiazolidinediones or a combination of these drugs fail, the GLP-1 mimectics may be preferred to insulin treatment. First, the risk of hypoglycaemia is less if not combined with SU. Secondly, the body weight is usually decreased while insulin treatment increases weight. Patients not responding to GLP-1 mimetics or experiencing significant side effects will be treated with insulin. Irrespective of the policy used for the drug treatment of type 2 diabetes, exercise and proper diet will remain important for optimization of metabolic control. Topics: Administration, Oral; Blood Glucose; Diabetes Mellitus, Type 2; Dipeptidyl Peptidase 4; Dipeptidyl-Peptidase IV Inhibitors; Exercise; Glucagon-Like Peptide 1; Humans; Hypoglycemic Agents; Insulin; Treatment Failure | 2008 |
Sitagliptin, a DPP-4 inhibitor for the treatment of patients with type 2 diabetes: a review of recent clinical trials.
Dipeptidyl peptidase-4 (DPP-4) inhibitors are a new class of oral antihyperglycemic agents that enhance the body's ability to regulate blood glucose by increasing the active levels of incretins, glucagon-like peptide 1 (GLP-1) and glucose-dependent insulinotropic peptide (GIP). There are numerous DPP-4 inhibitors in development with sitagliptin as the first approved agent for the treatment of patients with type 2 diabetes.. The purpose of this review is to provide an overview of the clinical trial results with sitagliptin.. Clinical trials published between January 2005 (first sitagliptin publication) and November 2007 were included in this review. Medline was searched using the search terms: MK-0431 or sitagliptin.. Sitagliptin, an oral, once-daily, and highly selective DPP-4 inhibitor, has been evaluated in clinical trials as monotherapy, as add-on therapy, or as initial combination therapy with metformin. Sitagliptin provided effective fasting and postprandial glycemic control in a wide range of patients with type 2 diabetes. Markers of beta-cell function (HOMA-beta and proinsulin/insulin ratio) were improved with sitagliptin treatment. In these clinical trials, sitagliptin was generally well tolerated with an overall incidence of adverse experiences comparable to placebo, a low risk of hypoglycemia or gastrointestinal adverse experiences, and a neutral effect on body weight. The findings presented in this review are limited to the specific patient population enrolled in each clinical trial and for durations for up to 1 year. Future clinical studies should evaluate whether this class of agents has the potential to delay progression and/or prevent type 2 diabetes.. Sitagliptin has been shown to be effective and well-tolerated in various treatment regimens and may be considered for both initial therapy and as add-on therapy for patients with type 2 diabetes. Topics: Blood Glucose; Diabetes Mellitus, Type 2; Gastric Inhibitory Polypeptide; Glucagon-Like Peptide 1; Humans; Hypoglycemic Agents; Incretins; Insulin-Secreting Cells; Metformin; Pyrazines; Sitagliptin Phosphate; Triazoles | 2008 |
The islet enhancer vildagliptin: mechanisms of improved glucose metabolism.
Vildagliptin is a potent, selective and reversible inhibitor of dipeptidyl peptidase-4 (DPP-4), the enzyme responsible for rapid inactivation of the incretin hormones glucagon-like peptide-1 (GLP-1) and gastric inhibitory polypeptide (GIP). GLP-1 and GIP are important for the maintenance of normal glucose homeostasis as they enhance the sensitivity of insulin (beta-cell) and glucagon (alpha-cell) secretion to glucose. The delicate balance that is achieved by the incretin hormones is disturbed in type 2 diabetes mellitus (T2DM). Mechanistic studies of vildagliptin performed to characterise the effects of DPP-4 inhibition on pancreatic islet function and glucose metabolism have found that vildagliptin produces dose-dependent reductions in DPP-4; these result in persistent levels of active GLP-1 and GIP in the circulation leading to improved beta-cell sensitivity to glucose and glucose-dependent insulin secretion, and improved alpha-cell sensitivity to glucose and reduction in inappropriate glucagon secretion. These islet effects in turn lead to a reduction of the inappropriate endogenous glucose production and glucose utilisation during meals, resulting in improved glucose tolerance, and to a reduction of the inappropriate endogenous glucose production during the postabsorptive period that contributes to a reduced fasting hyperglycaemia. These islet effects are associated with improved insulin sensitivity and reduced meal-related hypertriglyceridaemia. In contrast, the GLP-1 effect of significantly delaying gastric emptying was not evident with vildagliptin treatment. The metabolic benefits of vildagliptin observed in T2DM are also evident in subjects with impaired glucose tolerance. Hence, vildagliptin improves glucose metabolism mainly by improving islet function. Topics: Adamantane; Diabetes Mellitus, Type 2; Dipeptidyl-Peptidase IV Inhibitors; Gastric Emptying; Glucagon-Like Peptide 1; Glucose; Humans; Insulin Resistance; Islets of Langerhans; Lipid Metabolism; Liver; Nitriles; Pyrrolidines; Vildagliptin | 2008 |
Exploiting the antidiabetic properties of incretins to treat type 2 diabetes mellitus: glucagon-like peptide 1 receptor agonists or insulin for patients with inadequate glycemic control?
Type 2 diabetes mellitus is associated with progressive decreases in pancreatic beta-cell function. Most patients thus require increasingly intensive treatment, including oral combination therapies followed by insulin. Fear of hypoglycemia is a potential barrier to treatment adherence and glycemic control, while weight gain can exacerbate hyperglycemia or insulin resistance. Administration of insulin can roughly mimic physiologic insulin secretion but does not address underlying pathophysiology. Glucagon-like peptide 1 (GLP-1) is an incretin hormone released by the gut in response to meal intake that helps to maintain glucose homeostasis through coordinated effects on islet alpha- and beta-cells, inhibiting glucagon output, and stimulating insulin secretion in a glucose-dependent manner. Biological effects of GLP-1 include slowing gastric emptying and decreasing appetite. Incretin mimetics (GLP-1 receptor agonists with more suitable pharmacokinetic properties versus GLP-1) significantly lower hemoglobin A1c, body weight, and postprandial glucose excursions in humans and significantly improve beta-cell function in vivo (animal data). These novel incretin-based therapies offer the potential to reduce body weight or prevent weight gain, although the durability of these effects and their potential long-term benefits need to be studied further. This article reviews recent clinical trials comparing therapy with the incretin mimetic exenatide to insulin in patients with oral treatment failure, identifies factors consistent with the use of each treatment, and delineates areas for future research. Topics: Diabetes Mellitus, Type 2; Glucagon-Like Peptide 1; Glucagon-Like Peptide-1 Receptor; Glycated Hemoglobin; Humans; Hypoglycemic Agents; Incretins; Insulin; Liraglutide; Receptors, Glucagon | 2008 |
Exenatide as a treatment for diabetes and obesity: implications for cardiovascular risk reduction.
Among the challenges in improving outcomes in patients with diabetes is effectively implementing existing pharmacotherapies. However, current therapies for diabetes are often limited by adverse effects such as edema, hypoglycemia, and weight gain. Understanding the role of the incretin effect on the pathophysiology of diabetes has led to the development of new therapeutic agents. Exenatide is the first in a new class of agents termed "incretin mimetics," which replicate several glucoregulatory effects of the endogenous incretin hormone, glucagon-like peptide-1. In clinical trials, patients with type 2 diabetes treated with exenatide demonstrate sustained improvements in glycemic control, with reductions in fasting and postprandial glucose levels and improvements in glycosylated hemoglobin levels. Improvements in glycemic control with exenatide are coupled with reductions in body weight. Lipid parameters, blood pressure, and C-reactive protein have been shown to improve favorably in patients treated with exenatide. The sustained glycemic improvements and progressive reduction in body weight with exenatide treatment support a shift toward a more favorable cardiovascular risk profile and may have a positive impact on decreasing the risk of associated long-term complications. Topics: C-Reactive Protein; Comorbidity; Diabetes Mellitus, Type 2; Diabetic Angiopathies; Exenatide; Glucagon-Like Peptide 1; Humans; Hypoglycemic Agents; Incretins; Insulin; Obesity; Peptides; Protein Binding; Risk Factors; Venoms; Weight Loss | 2008 |
Incretins: pathophysiological and therapeutic implications of glucose-dependent insulinotropic polypeptide and glucagon-like peptide-1.
Incretins such as glucose-dependent insulinotropic polypeptide (GIP) and glucagon-like peptide-1 (GLP-1) are intestinal postprandial hormones that stimulate insulin release from the pancreas as long as circulating glucose concentrations are raised. In addition to their effect on insulin secretion and consequent glucose lowering, GIP and GLP-1, especially the latter, have a number of physiological effects such as inhibition of glucagon release, gastric emptying and food intake, as well as a tropic action on pancreatic B-cell mass. There is currently a pandemic of obesity and diabetes, and existing treatments are largely inadequate both in regard to efficacy as well as their ability to tackle important factors in the pathogenesis of type 2 diabetes (T2D). There is increasing evidence that current treatments do not address the issue of progressive B-cell failure in T2D. Since obesity is the engine that is driving the epidemic of diabetes, it is disappointing that most treatments that succeed in lowering plasma glucose are also associated with weight gain. It is now well established that intensively treated T2D has a better outcome than standard treatment. Consequently, achieving better control of diabetes with lower HbA1c is the goal of optimal treatment. Despite the use of usual therapeutic agents in T2D, often in high doses and as combinations, such as metformin, sulphonylurea, alpha-glycosidase inhibitors, thiazolidinediones and a number of animal and human insulin preparations, optimal control of glycaemia is not achieved. The use of incretins as therapeutic agents offers a new approach to the treatment of T2D. Topics: Amino Acid Sequence; Blood Glucose; Diabetes Mellitus, Type 2; Gastric Inhibitory Polypeptide; Glucagon-Like Peptide 1; Humans; Incretins; Molecular Sequence Data | 2008 |
Glucagon-like peptide 1 based therapy for type 2 diabetes.
Incidence of type 2 diabetes mellitus (T2DM) has increased in young people in recent years and new therapies are required for its effective treatment. Glucagon-like peptide 1 (GLP-1) is a potent blood glucose-lowering hormone produced in the L cells of the intestine. It may be potentially effective in the treatment of hyperglycemia in patients with T2DM.. PubMed database were searched with the terms "GLP-1", "incretins" and "diabetes".. GLP-1 is a product of the glucagon gene, and its secretion is controlled by both neural and endocrine signals. GLP-1 lowers plasma glucose by stimulating insulin and suppressing secretion of glucagons, thus inhibiting gastric emptying and reducing appetite. GLP-1 exerts these actions by the engagement of structurally distinct G-protein-coupled receptors (GPCRs). In patients with T2DM, GLP-1 increases insulin secretion and normalizes both fasting and postprandial blood glucose when given as a continuous intravenous infusion. However, the native hormone is unsuitable as a drug because it is broken down rapidly by dipeptidyl peptidase IV (DPP-4) and cleared by the kidneys. Fortunately, many GLP-1 agonists or analogues and DPP-4 inhibitors have been found or developed, such as exendin-4, exenatide, liraglutide, CJC1131, vidaliptin and P32/98. Clinical trials have shown their therapeutic functions in T2DM with little adverse reaction.. A GLP-1 based therapy will be safe and effective for the treatment of T2DM. Topics: Animals; Blood Glucose; Diabetes Mellitus, Type 2; Genetic Therapy; Glucagon-Like Peptide 1; Glucagon-Like Peptide-1 Receptor; Humans; Hypoglycemic Agents; Incretins; Insulin; Insulin Secretion; Receptors, Glucagon | 2008 |
GLP-1: physiological effects and potential therapeutic applications.
Glucagon-like peptide 1 (GLP-1) is a gut-derived incretin hormone with the potential to change diabetes. The physiological effects of GLP-1 are multiple, and many seem to ameliorate the different conditions defining the diverse physiopathology seen in type 2 diabetes. In animal studies, GLP-1 stimulates beta-cell proliferation and neogenesis and inhibits beta-cell apoptosis. In humans, GLP-1 stimulates insulin secretion and inhibits glucagon and gastrointestinal secretions and motility. It enhances satiety and reduces food intake and has beneficial effects on cardiovascular function and endothelial dysfunction. Enhancing incretin action for therapeutic use includes GLP-1 receptor agonists resistant to degradation (incretin mimetics) and dipeptidyl peptidase (DPP)-4 inhibitors. In clinical trials with type 2 diabetic patients on various oral antidiabetic regimes, both treatment modalities efficaciously improve glycaemic control and beta-cell function. Whereas the incretin mimetics induce weight loss, the DPP-4 inhibitors are considered weight neutral. In type 1 diabetes, treatment with GLP-1 shows promising effects. However, several areas need clinical confirmation: the durability of the weight loss, the ability to preserve functional beta-cell mass and the applicability in other than type 2 diabetes. As such, long-term studies and studies with cardiovascular end-points are needed to confirm the true benefits of these new classes of antidiabetic drugs in the treatment of diabetes mellitus. Topics: Animals; Diabetes Mellitus, Type 2; Dipeptidyl-Peptidase IV Inhibitors; Glucagon; Glucagon-Like Peptide 1; Glucagon-Like Peptide-1 Receptor; Humans; Hypoglycemic Agents; Islets of Langerhans; Receptors, Glucagon; Satiety Response; Weight Loss | 2008 |
The future of diabetes treatment.
Topics: Animals; Diabetes Mellitus; Diabetes Mellitus, Type 1; Diabetes Mellitus, Type 2; Glucagon-Like Peptide 1; Humans; Hypoglycemic Agents; Insulin-Secreting Cells | 2008 |
Emerging incretin based therapies for type 2 diabetes: incretin mimetics and DPP-4 inhibitors.
Type 2 diabetes is a chronic disease characterized by impaired insulin action, progressive beta cell dysfunction as well as abnormalities in pancreatic alpha cell function and postprandial substrate delivery. These pathophysiologic defects result in both persistent and progressive hyperglycemia, resulting in increased risk of both microvascular and cardiovascular complications. Traditional treatments for type 2 diabetes have focused on impaired insulin secretion and insulin resistance. These strategies are typically used in a stepwise manner: employing oral glucose lowering agents, followed by insulin therapy. This traditional approach fails to address the progressive decline in beta cell function. Moreover, these therapies are often associated with weight gain in overweight or obese patients with type 2 diabetes. Both exogenous insulin and insulin secretagogues are associated with an increased risk of hypoglycemia. Recently, new treatments that leverage the glucoregulatory effects of incretin hormones, such as glucagon like peptide 1 have been introduced. Both incretin mimetics and DPP-4 inhibitors address both the underlying pathophysiology and overcome several of the limitations of established therapies by providing improvements in glycemia, and control of body weight with minimal risk of hypoglycemia. Topics: Blood Glucose; Diabetes Mellitus, Type 2; Dipeptidyl-Peptidase IV Inhibitors; Exenatide; Glucagon-Like Peptide 1; Humans; Hypoglycemic Agents; Incidence; Incretins; Insulin; Insulin Secretion; Life Style; Liraglutide; Obesity; Overweight; Peptides; Prevalence; Venoms | 2008 |
Incretin mimetics and dipeptidyl peptidase 4 inhibitors in clinical trials for the treatment of type 2 diabetes.
Exenatide is an incretin mimetic, while sitagliptin and vildagliptin are incretin enhancers used as adjunctive therapy in patients with type 2 diabetes failing oral agents. Sitagliptin and vildagliptin can also be used as monotherapy in patients with type 2 diabetes uncontrolled by diet.. To provide a critical review of clinical trials of exenatide, sitagliptin and vildagliptin.. Review of Phase III clinical trials based on Medline search published up to April 2008.. The use of exenatide is associated with reduction in average hemoglobin A1c (HbA1c) levels of approximately 0.8% compared with baseline. The corresponding reduction with either sitagliptin or vildagliptin is 0.7%. The actions of incretin-based drugs predominantly target postprandial hyperglycemia. Treatment-related hypoglycemia is generally mild, and mainly occurs when used with sulfonylureas (SUs). Exenatide treatment leads to a mild weight loss of around 2 kg after 30 weeks, whereas sitagliptin and vildagliptin have generally neutral effect on weight. Sitagliptin and vildagliptin are well tolerated in trials lasting up to 52 weeks. Meanwhile, 5 - 10% of patients cannot tolerate exenatide due to adverse effects, mainly nausea and vomiting. The three drugs are limited by the lack of long-term safety and efficacy data, as well as by their high cost.. Exenatide, sitagliptin and vildagliptin are useful add-on therapy for type 2 diabetes that is suboptimally controlled on oral agents, particularly when there is concern about weight gain and hypoglycemia, or when postprandial hyperglycemia is the major cause of inadequate glycemic control. Sitagliptin and vildagliptin may be used as monotherapy in patients who cannot tolerate metformin or SU, and sitagliptin may be used as alternative to metformin in renal insufficiency. Topics: Adamantane; Body Weight; Clinical Trials, Phase III as Topic; Diabetes Mellitus, Type 2; Dipeptidyl Peptidase 4; Dipeptidyl-Peptidase IV Inhibitors; Double-Blind Method; Drug Therapy, Combination; Exenatide; Glucagon-Like Peptide 1; Glucagon-Like Peptide-1 Receptor; Glycated Hemoglobin; Humans; Hypoglycemia; Hypoglycemic Agents; Incretins; Insulin; Insulin Secretion; Nausea; Nitriles; Peptides; Pyrazines; Pyrrolidines; Randomized Controlled Trials as Topic; Receptors, Glucagon; Sitagliptin Phosphate; Triazoles; Venoms; Vildagliptin; Vomiting | 2008 |
ABCC8 and ABCC9: ABC transporters that regulate K+ channels.
The sulfonylurea receptors (SURs) ABCC8/SUR1 and ABCC9/SUR2 are members of the C-branch of the transport adenosine triphosphatase superfamily. Unlike their brethren, the SURs have no identified transport function; instead, evolution has matched these molecules with K(+) selective pores, either K(IR)6.1/KCNJ8 or K(IR)6.2/KCNJ11, to assemble adenosine triphosphate (ATP)-sensitive K(+) channels found in endocrine cells, neurons, and both smooth and striated muscle. Adenine nucleotides, the major regulators of ATP-sensitive K(+) (K(ATP)) channel activity, exert a dual action. Nucleotide binding to the pore reduces the activity or channel open probability, whereas Mg-nucleotide binding and/or hydrolysis in the nucleotide-binding domains of SUR antagonize this inhibitory action to stimulate channel openings. Mutations in either subunit can alter this balance and, in the case of the SUR1/KIR6.2 channels found in neurons and insulin-secreting pancreatic beta cells, are the cause of monogenic forms of hyperinsulinemic hypoglycemia and neonatal diabetes. Additionally, the subtle dysregulation of K(ATP) channel activity by a K(IR)6.2 polymorphism has been suggested as a predisposing factor in type 2 diabetes mellitus. Studies on K(ATP) channel null mice are clarifying the roles of these metabolically sensitive channels in a variety of tissues. Topics: Amino Acids; Animals; ATP-Binding Cassette Transporters; Calcium; Catecholamines; Congenital Hyperinsulinism; Diabetes Mellitus; Diabetes Mellitus, Type 2; Disease Models, Animal; Gastric Inhibitory Polypeptide; Glucagon-Like Peptide 1; Glucose; Humans; Infant; Infant, Newborn; Insulin; Insulin Secretion; Liver; Mice; Mice, Transgenic; Models, Molecular; Potassium Channels; Potassium Channels, Inwardly Rectifying; Protein Structure, Tertiary; Receptors, Drug; Sulfonylurea Receptors | 2007 |
Liraglutide: a once-daily GLP-1 analogue for the treatment of type 2 diabetes mellitus.
The incretin hormones are intestinal peptides that enhance insulin secretion following ingestion of nutrients. Liraglutide is a glucagon-like peptide-1 receptor analogue, which is obtained by derivatising glucagon-like peptide-1 with a fatty acid, providing a compound with pharmacokinetic properties that are suitable for once-daily dosing. Liraglutide has demonstrated lasting improvement of HbA(1c )levels, weight reduction and improved beta-cell function in patients with Type 2 diabetes mellitus. Liraglutide is well tolerated; the adverse events that are most frequently reported being transient nausea and diarrhoea. This article reviews the mechanisms of action and efficacy of liraglutide for the treatment of Type 2 diabetes mellitus. This agent is presently in Phase III clinical development. Topics: Animals; Diabetes Mellitus, Type 2; Drug Administration Schedule; Glucagon-Like Peptide 1; Humans; Liraglutide | 2007 |
[Drug treatment of type 2 diabetes].
Drug treatment of 2 diabetes is intended to normalize glycosylated hemoglobin levels (HbA(1c)<6.5%) and thereby prevent the development of micro- and macrovascular complications. Oral antidiabetic agents target the metabolic abnormalities that cause diabetes. The two principal families of oral antidiabetic agents - insulin sensitizers and insulin secretagogues - can be taken together. Thiazolidinediones or glitazones (insulin sensitizers) improve peripheral tissue sensitivity to insulin. Metformin (an insulin sensitizer) reduces hepatic glucose production. Sulfonylureas and meglitinides (insulin secretagogues) stimulate insulin secretion and can cause hypoglycemia. GLP-1 (Glucagon-Like Peptide-1) analogs and DPP-IV (dipeptidyl-peptidase-IV) inhibitors are new drug classes currently under development. Topics: Diabetes Mellitus, Type 2; Dipeptidyl-Peptidase IV Inhibitors; Glucagon-Like Peptide 1; Humans; Hypoglycemic Agents; Metformin; Sulfonylurea Compounds; Thiazolidinediones | 2007 |
Incretins and other peptides in the treatment of diabetes.
Glucagon-like peptide-1 (7-36) amide (GLP-1) is a gut hormone, released postprandially,which stimulates insulin secretion and insulin gene expression as well as pancreatic B-cell growth. Together with glucose-dependent insulinotropic polypeptide (GIP), it is responsible for the incretin effect which is the augmentation of insulin secretion following oral administration of glucose. Patients with Type 2 diabetes have greatly impaired or absent incretin-mediated insulin secretion which is mainly as a result of decreased secretion of GLP-1. However,the insulinotropic action of GLP-1 is preserved in patients with Type 2 diabetes,and this has encouraged attempts to treat Type 2 diabetic patients with GLP-1.GLP-1 also possesses a number of potential advantages over existing agents for the treatment of Type 2 diabetes. In addition to stimulating insulin secretion and promoting pancreatic B-cell mass, GLP-1 suppresses glucagon secretion,delays gastric emptying and inhibits food intake. Continuous intravenous and subcutaneous administration significantly improves glycaemic control and causes reductions in both HbA1c and body weight. However, GLP-1 is metabolized extremely rapidly in the circulation by the enzyme dipeptidyl peptidase IV(DPP-IV). This is the probable explanation for the short-lived effect of single doses of native GLP-1, making it an unlikely glucose-lowering agent. The DPP-IV resistant analogue, exenatide, has Food and Drug Administration (FDA) approval for the treatment of Type 2 diabetes and selective DPP-IV inhibitors are underdevelopment. Both approaches have demonstrated remarkable efficacy in animal models and human clinical studies. Both are well tolerated and appear to have advantages over current therapies for Type 2 diabetes, particularly in terms of the effects on pancreatic B-cell restoration and potential weight loss. Topics: Diabetes Mellitus, Type 2; Dipeptidyl Peptidase 4; Exenatide; Glucagon-Like Peptide 1; Humans; Hypoglycemic Agents; Insulin-Secreting Cells; Peptides; Venoms; Weight Loss | 2007 |
Mechanisms of action of glucagon-like peptide 1 in the pancreas.
Glucagon-like peptide 1 (GLP-1) is a hormone that is encoded in the proglucagon gene. It is mainly produced in enteroendocrine L cells of the gut and is secreted into the blood stream when food containing fat, protein hydrolysate, and/or glucose enters the duodenum. Its particular effects on insulin and glucagon secretion have generated a flurry of research activity over the past 20 years culminating in a naturally occurring GLP-1 receptor (GLP-1R) agonist, exendin 4 (Ex-4), now being used to treat type 2 diabetes mellitus (T2DM). GLP-1 engages a specific guanine nucleotide-binding protein (G-protein) coupled receptor (GPCR) that is present in tissues other than the pancreas (brain, kidney, lung, heart, and major blood vessels). The most widely studied cell activated by GLP-1 is the insulin-secreting beta cell where its defining action is augmentation of glucose-induced insulin secretion. Upon GLP-1R activation, adenylyl cyclase (AC) is activated and cAMP is generated, leading, in turn, to cAMP-dependent activation of second messenger pathways, such as the protein kinase A (PKA) and Epac pathways. As well as short-term effects of enhancing glucose-induced insulin secretion, continuous GLP-1R activation also increases insulin synthesis, beta cell proliferation, and neogenesis. Although these latter effects cannot be currently monitored in humans, there are substantial improvements in glucose tolerance and increases in both first phase and plateau phase insulin secretory responses in T2DM patients treated with Ex-4. This review will focus on the effects resulting from GLP-1R activation in the pancreas. Topics: Animals; Diabetes Mellitus, Type 2; Enteroendocrine Cells; Exenatide; Glucagon; Glucagon-Like Peptide 1; Glucagon-Like Peptide-1 Receptor; Glucose; Humans; Hypoglycemic Agents; Insulin; Insulin Secretion; Insulin-Secreting Cells; Pancreas; Peptides; Receptors, Glucagon; Second Messenger Systems; Venoms | 2007 |
Sitagliptin: Profile of a novel DPP-4 inhibitor for the treatment of type 2 diabetes.
Novel therapeutic strategies for type 2 diabetes are needed, since the current treatment options neither address all pathophysiological mechanisms nor achieve the glycemic target goals. A general islet-cell dysfunction including insulin- and glucagon-secretion defects contributes to the pathophysiology of type 2 diabetes. Improving islet function by incretin hormone action is a novel therapeutic approach. Glucagon-like peptide-1 (GLP-1) and glucose-dependent insulinotropic peptide (GIP) are important incretin hormones contributing to 50-70% of the stimulation of insulin secretion after a meal. Dipeptidyl-peptidase IV (DPP-4) inhibitors inhibit the degradation of GLP-1 and GIP as well as that of other regulatory peptides. Sitagliptin, a DPP-4 inhibitor, is orally active and has been shown to be efficacious and safe in clinical studies. Sitagliptin has received approval in Mexico, the United States and other countries. Like other DPP-4 inhibitors, sitagliptin reduces hemoglobin A1c (HbA1c), fasting and postprandial glucose by glucose-dependent stimulation of insulin secretion and inhibition of glucagon secretion. Sitagliptin is weight neutral. Indirect measures show a possible improvement of beta-cell function. Sitagliptin does not cause a higher rate of hypoglycemia in comparison to metformin or placebo. This article gives an overview of the mechanisms of action, pharmacology and clinical trial results of sitagliptin. Topics: Adenosine Deaminase Inhibitors; Diabetes Mellitus, Type 2; Dipeptidyl Peptidase 4; Dipeptidyl-Peptidase IV Inhibitors; Gastric Inhibitory Polypeptide; Glucagon-Like Peptide 1; Glycoproteins; Humans; Hypoglycemic Agents; Insulin-Secreting Cells; Pyrazines; Sitagliptin Phosphate; Triazoles | 2007 |
[Exenatide--an incretin-mimetic agent for the treatment of type 2 diabetes mellitus].
The incretin hormone glucagon-like peptide 1 (GLP-1) is being synthesized from L-cells in the gut and enhances glucose-induced insulin secretion. Metabolic control of type 2 diabetic patients can be markedly improved by additional administration of GLP-1, however, this peptide is almost immediately degraded and therefore has little clinical value. The synthetic GLP-1 agonist exenatide underlies a different metabolism and has recently been approved by the U.S. Food and Drug Administration for the adjunctive treatment of patients with type 2 diabetes who are suboptimally controlled with metformin and/or sulfonylurea. First controlled clinical trials provided evidence that glycaemic control under exenatide administered twice daily in a dose of 5-10 microg was not inferior to conventional insulin therapy. Novel aspects in the treatment of type 2 diabetes by GLP-1 receptor stimulation further include its influence on the insulin secretory pattern, insulin/glucagon ratio, body weight and possibly even pancreatic beta cell mass. However, a general application of exenatide in the treatment of type 2 diabetes will also largely depend on the therapy behavior of patients, a possible immunogenicity and the rate of adverse events. Furthermore, a possible indication for exenatide as first-line therapy of type 2 diabetes and the prognostic relevance of this novel therapeutic approach have yet to be defined. Topics: Amino Acid Sequence; Diabetes Mellitus, Type 2; Drug Interactions; Drug Therapy, Combination; Exenatide; Gastric Emptying; Gastrointestinal Diseases; Glucagon-Like Peptide 1; Glucagon-Like Peptide-1 Receptor; Humans; Hypoglycemic Agents; Insulin; Insulin Glargine; Insulin, Long-Acting; Metformin; Peptides; Receptors, Glucagon; Sulfonylurea Compounds; Venoms | 2007 |
Incretins: a new treatment option for type 2 diabetes?
This article describes how the discovery of a protein almost 100 years ago led to a clinical treatment for type 2 diabetes. Food intake, but also stimulation of the sympathetic nervous system (for example physical exercise), stimulates the secretion of glucagon-like-peptide-1 (GLP-1), derived from the glucagon precursor proglucagon in the small intestine. GLP-1 stimulates the production and secretion of insulin, the release of somatostatin, glucose utilisation by increasing insulin sensitivity and in animal studies also beta-cell function and expansion (proliferation). It inhibits glucagon release, gastric emptying, appetite and food intake via the central nervous system and in animal experiments also apoptosis of beta-cells. Since GLP-1 has to be administered parenterally and its half-life is short, a long-acting GLP-1 receptor agonist (exenatide) and a long-acting GLP-1 analogue (liraglutide) have been developed as well as an inhibitor of DPP-IV (the enzyme that breaks down endogenous GLP-1). Clinical studies with exenatide and liraglutide as monotherapy show a significant increase in the postprandial insulin concentration as well as a smaller increase in the postprandial glucose values. Adding these drugs to standard oral glucose-lowering medication shows improvement in glucose and insulin concentrations and HbA1c compared with adding placebo. The effect of exenatide on HbA1c is the same as adding a long-acting insulin analogue (glargine), but the increase in weight after adding insulin is not seen after exenatide, where even a small decrease in weight is found. This is an important advantage, because most type 2 patients are already obese. Whether less beta-cell apoptosis and maintenance of beta-cell function occurs, as has been shown in animal studies, has to be awaited. Clinical studies with the oral DPPIV inhibitors sitagliptin and vildagliptin show promising results, but are only published as abstracts at scientific meetings. Topics: Adenosine Deaminase; Diabetes Mellitus, Type 2; Dipeptidyl Peptidase 4; Glucagon; Glucagon-Like Peptide 1; Glucagon-Like Peptide-1 Receptor; Glycoproteins; Humans; Hypoglycemic Agents; Insulin-Secreting Cells; Receptors, Glucagon; Satiety Response | 2007 |
[Incretin enhancers, incretin mimetics: from therapeutic concept to clinical application].
The incretins are peptide hormones produced by special cell types of the intestines, which are secreted following ingestion of foods, indirectly, through a complex mechanism, by decreasing postprandial blood glucose levels participate in the regulation of the glucose homeostasis. The article beside of summarizing the physiological aspects of the two most important incretins, the glucagon-like peptide (GLP)-1 and glucose-dependent insulinotrope polypeptide (GIP), gives a detailed overview of multifaceted effects of GLP-1 and their potential application in the therapy of type 2 diabetes mellitus. The human GLP-1 because of its very short half-life is not suitable for therapeutic use. However, by inhibition its degradation, by suppression of activity of the serine peptidase type enzyme dipeptidyl peptidase (DPP) IV, its effect can be prolonged. Compounds with this effect have been synthetised, as well as drugs resistant to DPP IV, not being identical with the structure of the human GLP-1, but having agonist effect on its receptor could also be manufactured. Members of the first group are called incretin (GLP-1) enhancers, while of the second one incretin mimetics. Two of the enhancers, the sita- and vildagliptin, and one representative of the incretin mimetics, the exenatide after encouraging preclinical and human experiences have also been registered and introduced in the clinical practice. Their potential place in the treatment of type 2 diabetes is not exactly outlined at present. Though there are arguments underlining their early use in the glucose lowering drug treatment of type 2 diabetes, their application as part of a combination therapy seems to be a real indication. Topics: Adamantane; Adenosine Deaminase; Adenosine Deaminase Inhibitors; Animals; Blood Glucose; Diabetes Mellitus, Type 2; Dipeptidyl Peptidase 4; Dipeptidyl-Peptidase IV Inhibitors; Exenatide; Gastric Inhibitory Polypeptide; Gastrointestinal Hormones; Glucagon-Like Peptide 1; Glycoproteins; Humans; Hypoglycemic Agents; Insulin Resistance; Intestinal Mucosa; Nitriles; Peptide Hormones; Peptides; Pyrazines; Pyrrolidines; Sitagliptin Phosphate; Triazoles; Venoms; Vildagliptin | 2007 |
Dipeptidyl peptidase-4 inhibitors for the treatment of type 2 diabetes: focus on sitagliptin.
Dipeptidyl peptidase-4 (DPP-4) inhibitors represent a new class of oral antihyperglycemic agents to treat patients with type 2 diabetes. DPP-4 inhibitors improve fasting and postprandial glycemic control without hypoglycemia or weight gain. This article focuses on the physiology, clinical pharmacology, tolerability, and clinical utility of the DPP-4 inhibitor sitagliptin in the management of type 2 diabetes. Topics: Animals; Clinical Trials as Topic; Clinical Trials, Phase II as Topic; Clinical Trials, Phase III as Topic; Diabetes Mellitus, Type 2; Dipeptidyl Peptidase 4; Dipeptidyl-Peptidase IV Inhibitors; Glucagon-Like Peptide 1; Humans; Hypoglycemic Agents; Insulin Resistance; Protease Inhibitors; Pyrazines; Sitagliptin Phosphate; Triazoles | 2007 |
Progress in the treatment of type 2 diabetes: new pharmacologic approaches to improve glycemic control.
Type 2 diabetes mellitus (T2DM) is a leading cause of morbidity and mortality that places a substantial economic and health burden on the public. Successful management of T2DM requires strict control of glycemia as well as other risk factors to prevent disease progression. Despite the availability of multiple classes of oral antidiabetic drugs and insulin, the majority of patients fail to attain or maintain tight glycemic control over time, raising their risk of serious microvascular and macrovascular complications.. This review briefly outlines current standards of diabetes treatment and explores several new and investigational approaches. It is based on MEDLINE literature searches (1966-August 2006) and on abstracts from the American Diabetes Association Scientific Sessions (2002-2006) and the European Association for the Study of Diabetes Annual Meetings (1998-2006). Articles concerning basic science, preclinical, and clinical trial results were selected for this review based on their originality and relevance.. Medical professional societies and other specialist groups have proposed a series of practical steps to enable more patients with T2DM to reach treatment goals. Among their most important recommendations is a call for new drugs to stabilize or reverse the progressive pancreatic islet-cell dysfunction that characterizes the disease. New modalities, such as incretin mimetics and DPP-4 inhibitors, are now emerging from clinical development and will provide patients with more treatment options.. It appears likely that early and aggressive treatment with multiple drug combinations will become more common in the management of T2DM. The new treatment modalities discussed here offer hope for improved outcomes and for meeting the considerable public health challenges posed by this complex condition. However, long-term studies are needed to determine durability of treatment effects, as well as the ultimate role of these new agents in the management of patients with T2DM. Topics: Adenosine Deaminase Inhibitors; Blood Glucose; Clinical Trials as Topic; Diabetes Mellitus, Type 2; Dipeptidyl Peptidase 4; Dipeptidyl-Peptidase IV Inhibitors; Disease Progression; Drug Therapy, Combination; Drugs, Investigational; Gastric Inhibitory Polypeptide; Glucagon-Like Peptide 1; Glycoproteins; Humans; Hypoglycemic Agents; Models, Biological; Technology, Pharmaceutical | 2007 |
Inhibition of DPP-4: a new therapeutic approach for the treatment of type 2 diabetes.
Glucagon-like peptide-1 (GLP-1) and glucose-dependent insulinotropic polypeptide (GIP) are hormones secreted by the enteroendocrine cells of the gut in response to the ingestion of nutrients. These incretin hormones, so called because they increase insulin secretion, are key modulators of pancreatic islet hormone secretion and, thus, glucose homeostasis. The glucoregulatory effects of incretins are the basis for new therapies currently being developed for the treatment of type 2 diabetes mellitus (T2DM). Drugs that inhibit dipeptidyl peptidase-4 (DPP-4), a ubiquitous enzyme that rapidly inactivates both GLP-1 and GIP, increase active levels of these hormones and, in doing so, improve islet function and glycemic control in T2DM.. In this review, we briefly describe (1) the role of pancreatic islet dysfunction in the onset and progression of T2DM, (2) the rationale for developing drugs that enhance incretin activity, (3) the evidence that inhibition of DPP-4 is effective in ameliorating islet dysfunction and improving glycemic control in T2DM, (4) the efficacy, safety, and tolerability of DPP-4 inhibitors as monotherapy and in combination with other antidiabetic agents, and (5) the potential utility of DPP-4 inhibitors relative to existing oral antidiabetic agents and newer antidiabetic drugs in the pipeline. The review is based upon MEDLINE literature searches (1966-August 2006) and abstracts and presentations from the American Diabetes Association Scientific Sessions (2002-2006) and the European Association for the Study of Diabetes Annual Meetings (1998-2006). Basic science, preclinical, and clinical studies and review articles published in the English language were evaluated and selected based upon consideration of their originality, relevance, and frequency of citation.. DPP-4 inhibitors are a new class of antidiabetogenic drugs that provide comparable efficacy to current treatments. They are effective as monotherapy in patients inadequately controlled with diet and exercise and as add-on therapy in combination with metformin, thiazolidinediones, and insulin. The DPP-4 inhibitors are well tolerated, carry a low risk of producing hypoglycemia, and are weight neutral. The long-term durability of effect on glycemic control and beta-cell morphology and function remain to be established.. Islet cell dysfunction is central to the pathogenesis of T2DM. Incretin-based therapies, including GLP 1 analogues and DPP-4 inhibitors, have been shown to restore glucose homeostasis and improve glycemic control. The DPP-4 inhibitors, which can be used as monotherapy or in combination with other antidiabetic drugs, are a promising new treatment option, especially for patients with early-stage T2DM and more severe hyperglycemia. Topics: Adamantane; Adenosine Deaminase Inhibitors; Animals; Blood Glucose; Diabetes Mellitus, Type 2; Dipeptidyl Peptidase 4; Dipeptidyl-Peptidase IV Inhibitors; Drug Therapy, Combination; Gastric Inhibitory Polypeptide; Glucagon-Like Peptide 1; Glucose; Glycoproteins; Homeostasis; Humans; Hypoglycemic Agents; Islets of Langerhans; Models, Biological; Nitriles; Pyrazines; Pyrrolidines; Sitagliptin Phosphate; Triazoles; Vildagliptin | 2007 |
Pancreatic islet dysfunction in type 2 diabetes: a rational target for incretin-based therapies.
Insulin resistance alone does not result in the development of type 2 diabetes; progressive dysfunction of pancreatic islet alpha and beta cells, which results in inadequate control of hyperglycemia, must be present for the disease to develop. Because of these defects, meal-stimulated insulin secretion from beta cells is reduced and fails to meet the demands of the insulin-resistant state; in addition, glucagon production by alpha cells, which normally maintains hepatic glucose production during fasting periods, is not suppressed. This increased glucagon secretion leads to inappropriate levels of hepatic glucose output in the post-prandial state and consequently to hyperglycemia.. This review will examine the pathophysiologic processes of type 2 diabetes and provide an overview of some of the new and emerging treatments targeting pancreatic islet dysfunction. A MEDLINE search was performed for literature published in the English language from 1966-August 2006. Abstracts and presentations from the American Diabetes Association Scientific Sessions (2002-2006) and the European Association for the Study of Diabetes Annual Meetings (1998-2006) were also searched for relevant studies.. Key factors in maintaining the normal balance between insulin and glucagon levels are the incretins--glucagon-like peptide-1 (GLP-1) and glucose-dependent insulinotropic polypeptide (GIP). Intestinal absorption of glucose stimulates secretion of these hormones, which act to increase insulin and decrease glucagon secretion. Studies demonstrating that incretin activity is impaired in type 2 diabetes have led to investigations into incretin-based therapies such as incretin mimetics (analogues of GLP-1) and inhibitors of the enzyme dipeptidyl peptidase-4 (DPP-4), which inactivates native incretins.. Pancreatic islet dysfunction is a rational target for the treatment of type 2 diabetes. Incretin mimetics and DPP-4 inhibitors have been shown to improve glucose tolerance and may also hold the potential for improving overall pancreatic islet health. It should be noted, however, that the long-term effect of these agents on glycemic control has not yet been established, and their potential impact on beta-cell function in humans remains an area of active investigation. Topics: Adenosine Deaminase; Adenosine Deaminase Inhibitors; Diabetes Mellitus, Type 2; Dipeptidyl Peptidase 4; Dipeptidyl-Peptidase IV Inhibitors; Disease Progression; Gastric Inhibitory Polypeptide; Glucagon-Like Peptide 1; Glucose; Glucose Intolerance; Glycoproteins; Humans; Hypoglycemic Agents; Islets of Langerhans; Models, Biological | 2007 |
The role of vildagliptin in the management of type 2 diabetes mellitus.
To highlight the role of incretin hormones in the management of type 2 diabetes mellitus with a focus on vildagliptin, a dipeptidyl peptidase IV (DPP IV) inhibitor currently in development.. Searches were conducted in MEDLINE (1950-April 2007) and International Pharmaceutical Abstracts (1970-April 2007) using the key words vildagliptin, LAF237, and dipeptidyl peptidase IV inhibitor. Additional data were obtained from abstracts presented at the American Diabetes Association Scientific Sessions (2003-2006) and from the manufacturer.. Articles pertaining to the pharmacology, pharmacokinetics, safety, and efficacy of vildagliptin for the treatment of type 2 diabetes were reviewed for inclusion. When available, human trials were included over animal studies.. Reduced incretin effect is thought to be associated with type 2 diabetes. Glucagon-like peptide-1 (GLP-1), an incretin hormone, stimulates postprandial insulin release; however, it is rapidly degraded by DPP IV. Studies evaluating the use of vildagliptin in patients with type 2 diabetes found significant decreases in DPP IV and increased GLP-1 activity 45 minutes after dosing. Glucagon levels were reduced, with little to no change in insulin levels. With vildagliptin doses ranging from 25 mg daily to 100 mg twice daily, researchers observed consistent reductions in fasting plasma glucose, 4 hour postprandial glucose, and hemoglobin A1c. Similar benefits were seen when vildagliptin was used in combination with metformin. Vildagliptin was well tolerated after 12 weeks; however, incidences of hypoglycemia increased with longer study duration. Optimal results with minimal adverse effects were achieved with 25 mg twice daily and 50 mg once daily doses.. Vildagliptin represents a safe and effective new approach to targeting GLP-1 deficiencies in patients with type 2 diabetes by inhibiting DPP IV. Topics: Adamantane; Adenosine Deaminase Inhibitors; Animals; Clinical Trials as Topic; Diabetes Mellitus, Type 2; Dipeptidyl Peptidase 4; Dipeptidyl-Peptidase IV Inhibitors; Drug Interactions; Glucagon-Like Peptide 1; Glycoproteins; Humans; Hypoglycemic Agents; Nitriles; Pyrrolidines; Vildagliptin | 2007 |
New drugs for the treatment of type 2 diabetes.
Insights into the pathogenesis of type 2 diabetes has led to increasing therapeutic targets for intervention, and improvements in peptide delivery technology have lead to non-injection methods of insulin delivery. This article reviews new drugs which are likely to become available for use by people with diabetes over the coming year. Topics: Adenosine Deaminase Inhibitors; Administration, Inhalation; Amyloid; Cannabinoid Receptor Antagonists; Diabetes Mellitus, Type 2; Dipeptidyl Peptidase 4; Dipeptidyl-Peptidase IV Inhibitors; Forecasting; Glucagon-Like Peptide 1; Glycoproteins; Humans; Hypoglycemic Agents; Insulin; Islet Amyloid Polypeptide; Technology, Pharmaceutical | 2007 |
Biology of incretins: GLP-1 and GIP.
This review focuses on the mechanisms regulating the synthesis, secretion, biological actions, and therapeutic relevance of the incretin peptides glucose-dependent insulinotropic polypeptide (GIP) and glucagon-like peptide-1 (GLP-1). The published literature was reviewed, with emphasis on recent advances in our understanding of the biology of GIP and GLP-1. GIP and GLP-1 are both secreted within minutes of nutrient ingestion and facilitate the rapid disposal of ingested nutrients. Both peptides share common actions on islet beta-cells acting through structurally distinct yet related receptors. Incretin-receptor activation leads to glucose-dependent insulin secretion, induction of beta-cell proliferation, and enhanced resistance to apoptosis. GIP also promotes energy storage via direct actions on adipose tissue, and enhances bone formation via stimulation of osteoblast proliferation and inhibition of apoptosis. In contrast, GLP-1 exerts glucoregulatory actions via slowing of gastric emptying and glucose-dependent inhibition of glucagon secretion. GLP-1 also promotes satiety and sustained GLP-1-receptor activation is associated with weight loss in both preclinical and clinical studies. The rapid degradation of both GIP and GLP-1 by the enzyme dipeptidyl peptidase-4 has led to the development of degradation-resistant GLP-1-receptor agonists and dipeptidyl peptidase-4 inhibitors for the treatment of type 2 diabetes. These agents decrease hemoglobin A1c (HbA1c) safely without weight gain in subjects with type 2 diabetes. GLP-1 and GIP integrate nutrient-derived signals to control food intake, energy absorption, and assimilation. Recently approved therapeutic agents based on potentiation of incretin action provide new physiologically based approaches for the treatment of type 2 diabetes. Topics: Animals; Clinical Trials as Topic; Diabetes Mellitus, Type 2; Gastric Inhibitory Polypeptide; Gastrointestinal Hormones; Glucagon-Like Peptide 1; Glycated Hemoglobin; Hemoglobins; Humans; Insulin-Secreting Cells; Receptors, Glucagon; Signal Transduction | 2007 |
[New concepts in the treatment of type 2 diabetes].
The development of a variety of new substances will considerably expand the therapeutic choices in the treatment of type 2 diabetes. In 2006, the endocannabinoid receptor blocker Rimonabant has been approved for the treatment of type 2 diabetes in Germany. This compound has led to significant reductions of body weight along with improvements of HbA1c levels and lipid profiles, but the lack of health insurance coverage limits its large scale use in germany. In April 2007, the first members of the GLP 1 analogues/incretin mimetics (exenatide, Byetta) and DPP 4 inhbitors (sitagliptin, Januvia) have become available for the treatment of type 2 diabetes in Germany. Both drugs have significantly lowered HbA1c levels in clinical studies. In addition, the incretin mimetics have caused a progressive reduction of body weight, while the DPP 4 inhibitors have been rather weight neutral. Sitagliptin can be administered orally, whereas exenatide has to be injected subcutaneously. Neither the DPP 4 inhibitors, nor the incretin mimetics have led to the development of hypoglycaemia, unless combined with sulfonylureas. Overall, the introduction of these new drug classes will certainly broaden our therapeutic choices in the management of type 2 diabetes. The long-term effects of these drugs on the development of diabetic complications in long-term trials remains to be awaited. Topics: Adamantane; Blood Glucose; Clinical Trials as Topic; Diabetes Mellitus, Type 2; Dipeptidyl Peptidase 4; Dipeptidyl-Peptidase IV Inhibitors; Exenatide; Glucagon-Like Peptide 1; Glycated Hemoglobin; Humans; Hypoglycemic Agents; Insulin; Insulin Glargine; Insulin, Long-Acting; Liraglutide; Nitriles; Peptides; Piperidines; Pyrazines; Pyrazoles; Pyrrolidines; Rimonabant; Sitagliptin Phosphate; Triazoles; Venoms; Vildagliptin | 2007 |
[GLP-1-based treatment of type 2 diabetes mellitus].
GLP-1 is secreted from the small intestine in response to ingestion of nutrients. It has a powerful insulinotropic effect and stimulates beta-cell growth and is therefore being developed for treatment of type 2 diabetes. The GLP-1 analogue, exenatide, is on the market in the USA as an add-on therapy. Another strategy to increase circulating GLP-1 is to inhibit the enzyme DPP-IV which degrades endogenous GLP-1. GLP-1-based therapy results in HbA1c reductions of approximately 1 percent point, and the lack of serious side effects and the low risk of hypoglycaemic episodes are unique traits. Topics: Animals; Cell Count; Diabetes Mellitus, Type 2; Dipeptidyl-Peptidases and Tripeptidyl-Peptidases; Eating; Exenatide; Glucagon-Like Peptide 1; Humans; Hypoglycemic Agents; Insulin-Secreting Cells; Intestine, Small; Peptides; Venoms | 2007 |
[Effect of incretin hormones GIP and GLP-1 for the pathogenesis of type 2 diabetes mellitus].
Oral administration of glucose stimulates insulin secretion to a greater extent than does glucose administered as an isoglycaemic intravenous glucose infusion. This phenomenon is called the incretin effect and is caused by the two incretin hormones GIP and GLP-1. In patients with type 2 diabetes, the incretin effect is impaired. The mechanisms of the impaired incretin effect have been found to involve reduced secretion of GLP-1 and a severely impaired effect of GIP. It is currently unknown whether these defects are consequences of the diabetic state or primary pathogenetic factors. Topics: Diabetes Mellitus, Type 2; Gastric Inhibitory Polypeptide; Glucagon-Like Peptide 1; Glucose; Humans; Insulin; Insulin Secretion; Proglucagon | 2007 |
Review of sitagliptin phosphate: a novel treatment for type 2 diabetes.
Sitagliptin (Januvia, Merck Pharmaceuticals) is a dipeptidyl-peptidase inhibitor (DPP-4 inhibitor) that has recently been approved for the therapy of type 2 diabetes. Like other DPP-4 inhibitors its action is mediated by increasing levels of the incretin hormones glucagon-like peptide-1 (GLP-1) and gastric inhibitory polypeptide (GIP). Sitagliptin is effective in lowering HbA1c, and fasting as well as postprandial glucose in monotherapy and in combination with other oral antidiabetic agents. It stimulates insulin secretion when hyperglycemia is present and inhibits glucagon secretion. In clinical studies it is weight neutral. This article gives an overview of the mechanism of action, the pharmacology, and the clinical efficacy and safety of sitagliptin in type 2 diabetes therapy. Topics: Adenosine Deaminase; Adenosine Deaminase Inhibitors; Animals; Blood Glucose; Diabetes Mellitus, Type 2; Dipeptidyl Peptidase 4; Dipeptidyl-Peptidase IV Inhibitors; Glucagon-Like Peptide 1; Glycoproteins; Humans; Isoenzymes; Pyrazines; Sitagliptin Phosphate; Treatment Outcome; Triazoles | 2007 |
Is Glucagon-like peptide-1, an agent treating diabetes, a new hope for Alzheimer's disease?
Glucagon-like peptide-1 (GLP-1) has been endorsed as a promising and attractive agent in the treatment of type 2 diabetes mellitus (T2DM). Both Alzheimer's disease (AD) and T2DM share some common pathophysiologic hallmarks, such as amyloid beta (Abeta), phosphoralation of tau protein, and glycogen synthase kinase-3. GLP-1 possesses neurotropic properties and can reduce amyloid protein levels in the brain. Based on extensive studies during the past decades, the understanding on AD leads us to believe that the primary targets in AD are the Abeta and tau protein. Combine these findings, GLP-1 is probably a promising agent in the therapy of AD. This review was focused on the biochemistry and physiology of GLP-1, communities between T2DM and AD, new progresses of GLP-1 in treating T2MD and improving some pathologic hallmarks of AD. Topics: Alzheimer Disease; Amino Acid Sequence; Amyloid beta-Peptides; Animals; Brain; Diabetes Mellitus, Type 2; Glucagon-Like Peptide 1; Glucose; Humans; Molecular Sequence Data; tau Proteins | 2007 |
Efficacy and safety of incretin therapy in type 2 diabetes: systematic review and meta-analysis.
Pharmacotherapies that augment the incretin pathway have recently become available, but their role in the management of type 2 diabetes is not well defined.. To assess the efficacy and safety of incretin-based therapy in adults with type 2 diabetes based on randomized controlled trials published in peer-reviewed journals or as abstracts.. We searched MEDLINE (1966-May 20, 2007) and the Cochrane Central Register of Controlled Trials (second quarter, 2007) for English-language randomized controlled trials involving an incretin mimetic (glucagonlike peptide 1 [GLP-1] analogue) or enhancer (dipeptidyl peptidase 4 [DPP4] inhibitor). We also searched prescribing information, relevant Web sites, reference lists and citation sections of recovered articles, and abstracts presented at recent conferences.. Randomized controlled trials were selected if they were at least 12 weeks in duration, compared incretin therapy with placebo or other diabetes medication, and reported hemoglobin A(1c) data in nonpregnant adults with type 2 diabetes.. Two reviewers independently assessed trials for inclusion and extracted data. Differences were resolved by consensus. Meta-analyses were conducted for several efficacy and safety outcomes.. Of 355 potentially relevant articles identified, 51 were retrieved for detailed evaluation and 29 met the inclusion criteria. Incretins lowered hemoglobin A(1c) compared with placebo (weighted mean difference, -0.97% [95% confidence interval {CI}, -1.13% to -0.81%] for GLP-1 analogues and -0.74% [95% CI, -0.85% to -0.62%] for DPP4 inhibitors) and were noninferior to other hypoglycemic agents. Glucagonlike peptide 1 analogues resulted in weight loss (1.4 kg and 4.8 kg vs placebo and insulin, respectively) while DPP4 inhibitors were weight neutral. Glucagonlike peptide 1 analogues had more gastrointestinal side effects (risk ratio, 2.9 [95% CI, 2.0-4.2] for nausea and 3.2 [95% CI, 2.5-4.4] for vomiting). Dipeptidyl peptidase 4 inhibitors had an increased risk of infection (risk ratio, 1.2 [95% CI, 1.0-1.4] for nasopharyngitis and 1.5 [95% CI, 1.0-2.2] for urinary tract infection) and headache (risk ratio, 1.4 [95% CI, 1.1-1.7]). All but 3 trials had a 30-week or shorter duration; thus, long-term efficacy and safety could not be evaluated.. Incretin therapy offers an alternative option to currently available hypoglycemic agents for nonpregnant adults with type 2 diabetes, with modest efficacy and a favorable weight-change profile. Careful postmarketing surveillance for adverse effects, especially among the DPP4 inhibitors, and continued evaluation in longer-term studies and in clinical practice are required to determine the role of this new class among current pharmacotherapies for type 2 diabetes. Topics: Adamantane; Adenosine Deaminase Inhibitors; Diabetes Mellitus, Type 2; Dipeptidyl Peptidase 4; Dipeptidyl-Peptidase IV Inhibitors; Exenatide; Glucagon-Like Peptide 1; Glycoproteins; Humans; Hypoglycemic Agents; Liraglutide; Nitriles; Peptides; Pyrazines; Pyrrolidines; Sitagliptin Phosphate; Triazoles; Venoms; Vildagliptin | 2007 |
Incretin-based therapies: mimetics versus protease inhibitors.
The physiological incretins, glucose-dependent insulinotropic polypeptide (GIP) and glucagon-like peptide-1 (GLP-1), lower blood glucose levels through multiple mechanisms, including enhancement of glucose-stimulated insulin secretion. Although of demonstrated benefit to glycemic control in patients with type 2 diabetes, particularly for GLP-1, the half-lives of these peptides are too short for practical therapeutic utility. Here, we discuss recent approaches to incretin-based therapy, including the use of long-acting GLP-1 receptor agonists, degradation-resistant GLP-1 analogs, GLP-1 analogs conjugated to albumin, non-peptide small molecules that bind to the GLP-1 receptor, and inhibitors of dipeptidyl peptidase IV, the enzyme that degrades both GIP and GLP-1. Topics: Amino Acid Sequence; Animals; Biomimetics; Blood Glucose; Diabetes Mellitus, Type 2; Dipeptidyl-Peptidase IV Inhibitors; Drug Design; Gastric Inhibitory Polypeptide; Glucagon-Like Peptide 1; Humans; Hyperglycemia; Hypoglycemic Agents; Models, Biological; Molecular Sequence Data; Protease Inhibitors; Sequence Homology, Amino Acid | 2007 |
[What can be expected from the GLP-1 agonists and DPP-4 inhibitors in the treatment of type 2 diabetes?].
The GLP-1 agonists and DPP-4 inhibitors are two novel drug classes in the treatment of type 2 diabetes. They increase insulin secretion and inhibit glucagon secretion without risk of hypoglycaemia. A decrease of glycated haemoglobin of about 1% can be expected with their use as monotherapy and as add-on therapy to the usual oral antidiabetics. In addition, GLP-1 agonists induce weight reduction at the price of gastro-intestinal side-effects and the need for subcutaneous administration. DPP-4 inhibitors can be taken orally, are well-tolerated, but weight-neutral. In the absence of relevant clinical studies, their long-term efficacy is currently unknown, as well as the clinical impact of other promising effects like beta-cell preservation. Topics: Diabetes Mellitus, Type 2; Dipeptidyl-Peptidase IV Inhibitors; Glucagon-Like Peptide 1; Humans; Hypoglycemic Agents | 2007 |
Dipeptidyl peptidase IV inhibitors and the incretin system in type 2 diabetes mellitus.
As understanding of type 2 diabetes mellitus pathophysiology expands, treatments continue to evolve and new pharmacologic targets emerge. Patients with type 2 diabetes exhibit deficiencies of the incretin system; thus, methods for increasing insulinotropic hormones have become a popular target for therapy. A new class of oral antidiabetics has emerged-the dipeptidyl peptidase IV (DPP-IV) inhibitors. Unlike conventional oral antidiabetic agents, these agents promote glucose homeostasis through inhibition of DPP-IV, the enzyme responsible for degradation of two key glucoregulatory hormones: glucagon-like peptide-1 (GLP-1), which extends the action of insulin while also suppressing the release of glucagon, and glucose-dependent insulinotropic peptide (GIP). Other proposed mechanisms of action of GLP-1 and thus DPP-IV inhibitors include satiety, increased beta-cell production, and inhibition of apoptosis of beta cells. Clinical studies have evaluated the potential for DPP-IV inhibition to reduce glucagon levels, delay gastric emptying, and stimulate insulin release. The DPP-IV inhibitors appear to have excellent therapeutic potential in the management of type 2 diabetes as monotherapy or in combination with existing agents, such as metformin. Their pharmacokinetic and pharmacodynamic profiles support once-daily dosing, with sustainable reductions in glycosylated hemoglobin levels and relatively few adverse effects. Their distinctive mechanism of action and adverse-event profiles may offer advantages over existing therapies, including low risk for hypoglycemia and possible augmentation of pancreatic beta-cell regeneration. Topics: Adamantane; Adenosine Deaminase Inhibitors; Administration, Oral; Animals; Diabetes Mellitus, Type 2; Dipeptidyl Peptidase 4; Dipeptidyl-Peptidase IV Inhibitors; Drug Delivery Systems; Gastric Inhibitory Polypeptide; Glucagon-Like Peptide 1; Glycoproteins; Humans; Hypoglycemic Agents; Nitriles; Pyrazines; Pyrrolidines; Sitagliptin Phosphate; Triazoles; Vildagliptin | 2007 |
Impact of bariatric surgery on type 2 diabetes.
The management and prevention of diabetes through lifestyle modifications and weight loss should be the mainstay of therapy in appropriate candidates. Although the results from the Diabetes Prevention Trial and the Finnish Prevention Study support this approach, over 95% of patients not participating in a prevention research study are unable to achieve and maintain any significant weight loss over time. Bariatric surgery for weight loss is an emerging option for more sustainable weight loss in the severely obese subject, especially when obesity is complicated by diabetes or other co-morbidities. The two most common types of procedures currently used in the United States are adjustable gastric bands and Roux-en-Y gastric bypass. These procedures can be performed laparoscopically, further reducing the perioperative morbidity and mortality associated with the surgery. While the gastric bypass procedure usually results is greater sustained weight loss (40-50%) than adjustable gastric banding (20-30%), it also carries greater morbidity and nutritional/metabolic issues, such as deficiencies in iron, B12, calcium, and vitamin D. Following bariatric surgery most subjects experience improvements in diabetes control, hypertension, dyslipidemia, and other obesity-related conditions. In patients with impaired glucose tolerance most studies report 99-100% prevention of progression to diabetes, while in subjects with diabetes prior to surgery, resolution of the disease is reported in 64-93% of the cases. While improvements in insulin resistance and beta-cell function are related to surgically induced weight loss, the rapid post-operative improvement in glycemia is possibly due to a combination of decreased nutrient intake and changes in gut hormones as a result of the bypassed intestine. Post-prandial hyperinsulinemic hypoglycemia associated with nesidioblastosis has been described in a series of patients following gastric bypass surgery, and may be related to the described changes in GLP-1 and other gut hormones. Topics: Bariatric Surgery; Diabetes Mellitus, Type 2; Gastric Bypass; Gastroplasty; Glucagon-Like Peptide 1; Humans; Obesity; Postoperative Complications; Treatment Outcome; Weight Loss | 2007 |
Application of incretin mimetics and dipeptidyl peptidase IV inhibitors in managing type 2 diabetes mellitus.
Approximately two thirds of patients with type 2 diabetes mellitus (T2DM) are unable to reach the hemoglobin A(1c) target set by the American Diabetes Association (HbA(1c) <7.0%). Therefore, T2DM continues to be a major public health concern. Incretin mimetics and dipeptidyl peptidase IV inhibitors are medications that have the potential to improve patients' glycemic control, as well as to result in beneficial socioeconomic effects. Research suggests that significant benefits are to be gained from incretin mimetics and dipeptidyl peptidase IV inhibitors, either one used as monotherapy or used together as combination therapy. However, the benefits and risks of these agents need to be evaluated more thoroughly, with emphasis on such adverse effects as edema, hypoglycemia, and weight gain. Topics: Diabetes Mellitus, Type 2; Dipeptidyl Peptidase 4; Dipeptidyl-Peptidase IV Inhibitors; Dose-Response Relationship, Drug; Drug Administration Schedule; Exenatide; Female; Gastric Inhibitory Polypeptide; Glucagon-Like Peptide 1; Humans; Hyperglycemia; Hypoglycemic Agents; Liraglutide; Male; Peptides; Probability; Prognosis; Treatment Outcome; Venoms | 2007 |
The pathophysiologic role of incretins.
Many patients with type 2 diabetes mellitus (T2DM) are unable to achieve adequate glycemic control. Of the approximately 19 million individuals with T2DM in the United States, only about a third achieve the hemoglobin A(1c) (HbA(1c)0 goal set forth by the American Diabetes Association (HbA(1c) <7% [6% if it can be achieved safely]). The incretin mimetics are a new class of medications available for treating patients with T2DM. They mimic the action of incretins, which are peptide hormones that originate in the gastrointestinal tract. The two major incretins in humans are glucagon-like peptide 1 (GLP-1) and glucose-dependent insulinotropic peptide (GIP). These hormones are released during nutrient absorption, augmenting insulin secretion. However, incretins are susceptible to degradation by dipeptidyl peptidase IV (DPP-IV). Dipeptidyl peptidase IV inhibitors suppress the degradation of incretins, thus extending the activity of GLP-1 and GIP. The glycemic profiles of patients after administration of incretin mimetics and DPP-IV inhibitors show improvement in postprandial glucose levels and ultimately in HbA(1c). Therefore, incretin mimetics and DPP-IV inhibitors may play a clinically significant role in the treatment of patients with T2DM. Topics: Blood Glucose; Case-Control Studies; Cross-Over Studies; Diabetes Mellitus, Type 2; Female; Gastric Inhibitory Polypeptide; Glucagon-Like Peptide 1; Humans; Male; Prognosis; Reference Values; Severity of Illness Index | 2007 |
Using prandial insulin to achieve glycemic control in type 2 diabetes.
Topics: Algorithms; Blood Glucose; Clinical Trials as Topic; Diabetes Mellitus, Type 2; Exenatide; Glucagon-Like Peptide 1; Humans; Hyperglycemia; Hypoglycemic Agents; Insulin; Insulin Glargine; Insulin, Long-Acting; Liraglutide; Peptides; Postprandial Period; Pyrazines; Risk Factors; Sitagliptin Phosphate; Triazoles; Venoms | 2007 |
[Incretin mimetics and incretin enhancers for the treatment of type 2 diabetes].
Glucagon-like peptide-1 (GLP-1) is a gut hormone secreted in response to a meal ingestion, which is rapidly degraded by a specific enzyme, dipeptidylpeptidase-4 (DPP-4). It enhances insulin secretion in a glucose-dependent manner, inhibits glucagon secretion, retards gastric emptying,... Two pharmacological approaches have been developed to increase the abnormally low GLP-1 levels in type 2 diabetic patients: either to subcutaneously inject an agent closed to GLP-1 (exenatide), which is partially resistant to the action of DPP-4, either to orally administer a selective DPP-4 inhibitor (sitagliptin,...). These new drugs offer improved blood glucose control of type 2 diabetic patients, without inducing hypoglycaemia and with favourable effects on body weight. Topics: Diabetes Mellitus, Type 2; Dipeptidyl Peptidase 4; Dipeptidyl-Peptidase IV Inhibitors; Glucagon-Like Peptide 1; Humans; Hypoglycemic Agents | 2007 |
BIM-51077, a dipeptidyl peptidase-IV-resistant glucagon-like peptide-1 analog.
F Hoffmann-La Roche Ltd, Teijin Ltd and Chugai Pharmaceutical Co Ltd, under license from Ipsen, are developing the glucagon-like peptide 1 analog BIM-51077, for the potential treatment of type 2 diabetes. Phase II clinical trials are underway, including a phase II trial evaluating a slow release formulation. Topics: Animals; Diabetes Mellitus, Type 2; Dipeptidyl Peptidase 4; Dipeptidyl-Peptidase IV Inhibitors; Drug Evaluation, Preclinical; Glucagon-Like Peptide 1; Humans; Hypoglycemic Agents; Structure-Activity Relationship | 2007 |
Incretins and their role in the management of diabetes.
To review data from clinical trials of incretin mimetics in patients with type 2 diabetes.. Incretin mimetics are a new class of antidiabetic medication that mimic the actions of the hormone glucagon-like peptide-1. They exhibit several properties, including glucose-dependent stimulation of insulin secretion, suppression of glucagon secretion, slowing of gastric emptying and induction of satiety, which result in improvements in glycemic control with weight loss in patients with type 2 diabetes. Recent 2-year data with exenatide, the only commercially available incretin mimetic, have demonstrated long-term sustained reductions in hemoglobin A1c with progressive weight loss. Glycemic and weight benefits were also recently reported in a 15-week study assessing once-weekly administration of long-acting release exenatide, a formulation currently in phase 3 of clinical development. Once-daily administration of liraglutide, also in phase 3 of development, has recently been shown to improve glycemic and weigh control as monotherapy, and in combination with metformin. The most common side effects of incretin mimetics are gastrointestinal in nature, particularly nausea.. The ability of incretin mimetics to improve glycemic control and reduce body weight is a unique property that fills an important void in the treatment of patients with type 2 diabetes. Topics: Blood Glucose; Body Weight; Diabetes Mellitus, Type 2; Exenatide; Glucagon-Like Peptide 1; Humans; Hypoglycemic Agents; Incretins; Liraglutide; Molecular Mimicry; Peptides; Venoms | 2007 |
Modulation of glucagon-like peptide 1 and energy metabolism by inulin and oligofructose: experimental data.
Inulin-type fructans have been tested for their capacity to modulate lipid and glucose metabolism in several animal models. Oligofructose (OFS) decreases food intake, fat mass development, and hepatic steatosis in normal and in obese rats; moreover, it exerts an antidiabetic effect in streptozotocin-treated rats and high-fat-fed mice. In most cases, the beneficial effects of OFS are linked to an increase of glucagon-like peptide-1 (GLP-1) level in the portal vein and of GLP-1 and proglucagon mRNA, its precursor, in the proximal colon. In this organ, OFS increases the number of GLP-1-positive L cells by promoting factors (Neurogenin 3 and NeuroD) involved in the differentiation of stem cells into L cells. The chronic administration of GLP-1 receptor antagonist exendin 9-39 totally prevents the beneficial effects of OFS (improved glucose tolerance, fasting blood glucose, glucose-stimulated insulin secretion, insulin-sensitive hepatic glucose production, and reduced body weight gain). Furthermore GLP-1 receptor knockout mice are completely insensitive to the antidiabetic actions of OFS. These findings highlight the potential interest of enhancing endogenous GLP-1 secretion by inulin-type fructans for the prevention/treatment of obesity and type 2 diabetes. Moreover, OFS is also able to modulate other gastrointestinal peptides (such as PYY and ghrelin) that could be involved in the control of food intake. Several studies in humans already support interest in OFS in the control of satiety, triglyceridemia, or steatohepatitis. The link with gut peptides production in humans remains to be proven. Topics: Animals; Diabetes Mellitus, Type 2; Energy Metabolism; Glucagon-Like Peptide 1; Glucose; Humans; Inulin; Lipid Metabolism; Obesity; Oligosaccharides | 2007 |
[Incretin strategy in the treatment of type 2 diabetes mellitus--DPPIV].
Administration ofGLP-1 analogue resistant to DPPIV or therapeutic inhibition ofthe enzymes, allowing for an increase in the levels of GLP-1, are the very new approaches to the treatment of type 2 diabetes mellitus. Incretin therapy has an immense potential of improving unsatisfactory compensation in diabetic patients thus reducing the risk of manifestation of all arterial complications. Low fasting circulating levels of GLP-1 (and also GIP) grow rapidly after eating and are subsequently degraded to inactive forms by dipeptidyl peptidases IV (DPPIV). DPPIV are enzymes widely present in the body which proteolytically degrade GLP-1 and GIP (as well as other active substances). The preventing of their inactivation effect by administering DPPIV inhibitors allows for increasing the GLP-1 levels, which are reduced in type 2 diabetic patients, and subsequently improves glucose homeostasis in such patients. DPPIV inhibitors represent the principal new class of PAD, and their metabolic profile offers a number of unique clinical advantages for the treatment of patients with type 2 diabetes mellitus. Topics: Diabetes Mellitus, Type 2; Glucagon-Like Peptide 1; Humans; Incretins; Insulin | 2007 |
Bodyweight changes associated with antihyperglycaemic agents in type 2 diabetes mellitus.
The majority of patients with type 2 diabetes mellitus are overweight or obese at the time of diagnosis, and obesity is a recognised risk factor for type 2 diabetes and coronary heart disease (CHD). Conversely, weight loss has been shown to improve glycaemic control in patients with type 2 diabetes, as well as to lower the risk of CHD. The traditional pharmacotherapies for type 2 diabetes can further increase weight and this may undermine the benefits of improved glycaemic control. Furthermore, patients' desire to avoid weight gain may jeopardise compliance with treatment, thereby limiting treatment success and indirectly increasing the risk of long-term complications. This review evaluates the influences of established and emerging therapies on bodyweight in type 2 diabetes. Improvement in glycaemic control with insulin secretagogues has been associated with weight gain. On the other hand, biguanides such as metformin have been consistently shown to have a beneficial effect on weight; metformin appears to modestly reduce weight when used as a monotherapy. alpha-Glucosidase inhibitors are considered weight neutral; in fact, the results of some studies show that they cause reductions in weight. Thiazolidinediones (TZDs) are typically associated with weight gain and increased risk of oedema, while the impact of some TZDs, such as pioglitazone, on lipid homeostasis could be beneficial. Insulin, the most effective therapy when oral agents are ineffective, has always been linked to significant weight gain. Newly developed insulin analogues can lower the risk of hypoglycaemia compared with human insulin, but most have no advantage in terms of weight gain. The basal analogue insulin detemir, however, has been demonstrated to cause weight gain to a lesser extent than human insulin. The emerging treatments, such as glucagon-like peptide-1 agonists and the amylin analogue, pramlintide, seem able to decrease weight in patients with type 2 diabetes, whereas dipeptidyl peptidase-4 inhibitors seem to be weight neutral. In summary, while reduction of hyperglycaemia remains the foremost goal in the treatment of patients with type 2 diabetes, the avoidance of weight gain may be a clinically important secondary goal. This is already possible with careful selection of available therapies, while several emerging therapies promise to further extend the options available. Topics: Amyloid; Benzamides; Biguanides; Body Weight; Diabetes Mellitus, Type 2; Dipeptidyl-Peptidase IV Inhibitors; Glucagon-Like Peptide 1; Glycoside Hydrolase Inhibitors; Humans; Hypoglycemic Agents; Insulin; Insulin Secretion; Islet Amyloid Polypeptide; Obesity; Sulfonylurea Compounds; Thiazolidinediones; Weight Gain | 2007 |
Incretin hormone mimetics and analogues in diabetes therapeutics.
The incretin hormones glucagon-like peptide-1 (GLP-1) and glucose-dependent insulinotropic polypeptide (GIP) are physiological gut peptides with insulin-releasing and extrapancreatic glucoregulatory actions. Incretin analogues/mimetics activate GLP-1 or GIP receptors whilst avoiding physiological inactivation by dipeptidyl peptidase 4 (DPP-4), and they represent one of the newest classes of antidiabetic drug. The first clinically approved GLP-1 mimetic for the treatment of type-2 diabetes is exenatide (Byetta/exendin) which is administered subcutaneously twice daily. Clinical trials of liraglutide, a GLP-1 analogue suitable for once-daily administration, are ongoing. A number of other incretin molecules are at earlier stages of development. This review discusses the various attributes of GLP-1 and GIP for diabetes treatment and summarises current clinical data. Additionally, it explores the therapeutic possibilities offered by preclinical agents, such as non-peptide GLP-1 mimetics, GLP-1/glucagon hybrid peptides, and specific GIP receptor antagonists. Topics: Amino Acid Sequence; Amino Acid Substitution; Diabetes Mellitus, Type 2; Dipeptidyl Peptidase 4; Exenatide; Gastric Inhibitory Polypeptide; Glucagon-Like Peptide 1; Humans; Hypoglycemic Agents; Incretins; Liraglutide; Molecular Sequence Data; Peptides; Receptors, Gastrointestinal Hormone; Venoms | 2007 |
DPP-4 inhibitors.
Inhibition of dipeptidyl peptidase 4 (DPP-4) is a novel treatment for type-2 diabetes. DPP-4 inhibition prevents the inactivation of glucagon-like peptide 1 (GLP-1), which increases levels of active GLP-1. This increases insulin secretion and reduces glucagon secretion, thereby lowering glucose levels. Several DPP-4 inhibitors are in clinical development. Most experience so far has been with sitagliptin (Merck; approved by the FDA) and vildagliptin (Novartis; filed). These are orally active compounds with a long duration, allowing once-daily administration. Both sitagliptin and vildagliptin improve metabolic control in type-2 diabetes, both in monotherapy and in combination with metformin and thiazolidinediones. A reduction in HbA(1c) of approximately 1% is seen in studies of DPP-4 inhibition of up to 52 weeks' duration. DPP-4 inhibition is safe and well tolerated, the risk of hypoglycaemia is minimal, and DPP-4 inhibition is body-weight neutral. DPP-4 inhibition is suggested to be a first-line treatment of type-2 diabetes, particularly in its early stages in combination with metformin. However, the durability and long-term safety of DPP-4 inhibition remain to be established. Topics: Adamantane; Animals; Body Weight; Diabetes Mellitus, Type 2; Dipeptidyl-Peptidase IV Inhibitors; Drug Therapy, Combination; Glucagon; Glucagon-Like Peptide 1; Humans; Hypoglycemia; Hypoglycemic Agents; Insulin; Insulin Secretion; Lipid Metabolism; Metformin; Nitriles; Pioglitazone; Protease Inhibitors; Pyrazines; Pyrrolidines; Sitagliptin Phosphate; Substrate Specificity; Thiazolidinediones; Triazoles; Vildagliptin | 2007 |
Dipeptidyl peptidase-iV inhibitors: fixing type 2 diabetes?
The optimal treatment of type 2 diabetes is currently uncertain. This article reviews a new class of oral hypoglycaemic agents: dipeptidyl peptidase-IV inhibitors. By potentiating the action of incretins they offer a more 'physiological' control of blood sugar with fewer side effects, and the possibility of ameliorating the decline in beta cell function. Topics: Diabetes Mellitus, Type 2; Dipeptidyl-Peptidase IV Inhibitors; Gastric Inhibitory Polypeptide; Glucagon-Like Peptide 1; Humans; Hypoglycemic Agents; Incretins; Treatment Outcome | 2007 |
GLP-1-based therapy of type 2 diabetes: GLP-1 mimetics and DPP-IV inhibitors.
Glucagon-like peptide-1 (GLP-1)-based therapy is a novel treatment for type 2 diabetes. It is executed either by GLP-1 mimetics or by dipeptidyl peptidase-IV inhibitors. In type 2 diabetes, the two strategies reduce hemoglobin A(1c) by 0.6% to 1.1% from baseline levels of 7.7% to 8.5%. They are efficient both in monotherapy and in combination with metformin or thiazolidinediones. Both treatments are well tolerated with low risk of hypoglycemia. Topics: Adamantane; Body Weight; Diabetes Mellitus, Type 2; Dipeptidyl Peptidase 4; Dipeptidyl-Peptidase IV Inhibitors; Enzyme Inhibitors; Exenatide; Gastric Emptying; Glucagon-Like Peptide 1; Hypoglycemic Agents; Incretins; Islets of Langerhans; Liraglutide; Nitriles; Peptides; Pyrazines; Pyrrolidines; Sitagliptin Phosphate; Triazoles; Venoms; Vildagliptin | 2007 |
Sitagliptin: profile of a novel DPP-4 inhibitor for the treatment of type 2 diabetes (update).
Novel therapeutic strategies for type 2 diabetes are needed, since the current treatment options neither address all pathophysiological mechanisms nor achieve the glycemic target goals. A general islet-cell dysfunction including insulin- and glucagon-secretion defects contributes to the pathophysiology of type 2 diabetes. Improving islet function by incretin hormone action is a novel therapeutic approach. Glucagon-like peptide-1 (GLP-1) and glucose-dependent insulinotropic peptide (GIP) are important incretin hormones contributing to 50-70% of the stimulation of insulin secretion after a meal. Dipeptidyl-peptidase IV (DPP-4) inhibitors inhibit the degradation of GLP-1 and GIP as well as that of other regulatory peptides. Sitagliptin, a DPP-4 inhibitor, is orally active and has been shown to be efficacious and safe in clinical studies. Sitagliptin has received approval in Mexico, the United States and other countries. Like other DPP-4 inhibitors, sitagliptin reduces hemoglobin A1c (HbA1c), fasting and postprandial glucose by glucose-dependent stimulation of insulin secretion and inhibition of glucagon secretion. Sitagliptin is weight neutral. Indirect measures show a possible improvement of beta-cell function. Sitagliptin does not cause a higher rate of hypoglycemia in comparison to metformin or placebo. This article gives an overview of the mechanisms of action, pharmacology and clinical trial results of sitagliptin. Topics: Clinical Trials as Topic; Diabetes Mellitus, Type 2; Dipeptidyl Peptidase 4; Dipeptidyl-Peptidase IV Inhibitors; Glucagon-Like Peptide 1; Humans; Hypoglycemic Agents; Insulin-Secreting Cells; Pyrazines; Sitagliptin Phosphate; Triazoles | 2007 |
Sitagliptin phosphate: a DPP-4 inhibitor for the treatment of type 2 diabetes mellitus.
Sitagliptin phosphate, the first dipeptidyl peptidase 4 (DPP-4) inhibitor, provides a new treatment option for patients with type 2 diabetes.. The purpose of this article is to review the pharmacology, pharmacokinetics, pharmacodynamics, clinical efficacy, adverse effects, and cost of sitagliptin in adults with type 2 diabetes.. A literature search of MEDLINE (1966-May 10, 2007), Iowa Drug Information Service (1966-May 10, 2007), and International Pharmaceutical Abstracts (1970-May 10, 2007) was performed using the terms sitagliptin and MK-0431. English-language, original research and review articles were reviewed, as were citations from these articles. The 2005 and 2006 American Diabetes Association Scientific Abstracts were searched, and the US Food and Drug Administration review of the new drug application for sitagliptin and select information from the manufacturer were consulted.. By inhibiting DPP-4, sitagliptin enhances postprandial levels of active glucagon-like peptide-1 (GLP-1), leading to a rise in insulin release and decrease in glucagon secretion from pancreatic alpha-cells. Sitagliptin is 87% orally bioavailable, undergoes minimal hepatic metabolism, and is primarily excreted unchanged (approximately 79%) in the urine. At doses >or=100 mg QD, DPP-4 activity is inhibited by >80%, with a consequent 2-fold rise in active GLP-1 levels. The reduction in glycosylated hemoglobin (HbA(1c)) observed with 100 mg QD of sitagliptin in Phase III monotherapy trials ranged from approximately 0.5% to 0.6% (P Topics: Clinical Trials as Topic; Diabetes Mellitus, Type 2; Dipeptidyl-Peptidase IV Inhibitors; Drug Therapy, Combination; Glucagon-Like Peptide 1; Glycated Hemoglobin; Humans; Hypoglycemic Agents; Molecular Structure; Pyrazines; Sitagliptin Phosphate; Triazoles | 2007 |
Pathophysiology of type 2 diabetes and the role of incretin hormones and beta-cell dysfunction.
Type 2 diabetes is a heterogeneous, polygenic disorder in which dysfunction in a number of important metabolic pathways appears to play roles. Although it remains unclear exactly which event triggers the disorder, beta-cell dysfunction is a key element in the underlyingpathophysiology. Both impaired insulin secretion and insulin resistance contribute to the hyperglycemic state that causes the devastating cardiovascular, neurologic, and renal effects characteristic of type 2 diabetes. To prevent these complications, the American Diabetes Association recommends maintaining A1C levels below 7%. A1C has long been the target of diabetes therapy, and while this remains true in those with A1C levels above 8.4%, it is now apparent that in those with mild to moderate diabetes, postprandial glucose excursions may be of greater importance. Postprandial hyperglycemia occurs in 74% of those diagnosed with diabetes and 39% of those with optimal A1C levels. Involvement of impaired alpha-cell function has recently been recognized in the pathophysiology of type 2 diabetes. As a result of this dysfunction, glucagon and hepatic glucose levels that rise during fasting are not suppressed with a meal. Given inadequate levels of insulin and increased insulin resistance, hyperglycemia results. The incretins are important gut mediators of insulin release, and in the case of GLP-1, of glucagon suppression. Although GIP activity is impaired in those with type 2 diabetes, GLP-1 insulinotropic effects are preserved, and thus GLP-1 represents a potentially beneficial therapeutic option. However, like GIP, GLP-1 is rapidly inactivated by DPP-IV in vivo. Two therapeutic approaches to this problem have been developed: GLP-1 analogs with increased half-lives, and DPP-IV inhibitors, which prevent the breakdown of endogenous GLP-1 as well as GIP. Both classes of agent have shown promise, with potential not only to normalize fasting and postprandial glucose levels but also to improve beta-cell functioning and mass. Topics: Diabetes Mellitus, Type 2; Disease Progression; Gastric Inhibitory Polypeptide; Glucagon-Like Peptide 1; Humans; Hyperglycemia; Incretins; Insulin-Secreting Cells; Pancreatic Diseases; Postprandial Period | 2007 |
Adapting the GLP-1-signaling system to the treatment of type 2 diabetes.
Glucagon-like peptide-1 (GLP-1) may contribute to the decreased incretin effect characterizing type 2 diabetes. Multiple actions other than insulin secretion stimulation give to GLP-1 a highly desirable profile for an antidiabetic agent. To overcome the need for continuous infusion of the native compound, which is rapidly degraded by dimethyl-peptidyl-peptidase-IV (DPP-IV), analogues with low affinity for this protease have been developed. A second major strategy is represented by DPP-IV inhibitors that act to increase endogenous GLP-1. On the basis of the promising results in clinical trials, the incretin-based therapy may offer an useful option for diabetes management. Topics: Diabetes Mellitus, Type 2; Dipeptidyl Peptidase 4; Dipeptidyl-Peptidase IV Inhibitors; Drug Delivery Systems; Enzyme Inhibitors; Gastric Inhibitory Polypeptide; Glucagon-Like Peptide 1; Humans; Hypoglycemic Agents; Incretins; Liraglutide; Maleimides; Peptides; Protein Processing, Post-Translational; Signal Transduction | 2007 |
New therapies for diabetes.
The role of hormones secreted by the gut in maintaining blood glucose homeostasis has recently been recognized. This recognition has led to the emergence of several novel classes of medications--the glucagon-like peptide-1 (GLP-1) agonists and the dipeptidyl peptidase (DPP)-IV inhibitors--that may target a key element of the underlying pathophysiology of type 2 diabetes mellitus (DM). Both GLP-1 agonists and DPP-IV inhibitors may have the ability to expand beta-cell mass. Because the demise of beta-cell mass and function is a critical element in the progression of type 2 DM, these agents may have the potential to reverse the natural history of type 2 DM. However, further studies are needed to confirm both long-term beta-cell preservation and the role of these agents in the management of diabetes. Topics: Amyloid; Blood Glucose; Diabetes Mellitus, Type 2; Dipeptidyl-Peptidases and Tripeptidyl-Peptidases; Disease Progression; Exenatide; Glucagon-Like Peptide 1; Humans; Hypoglycemic Agents; Islet Amyloid Polypeptide; Liraglutide; Peptides; Venoms | 2007 |
Role of glucagon-like peptide-1 in the pathogenesis and treatment of diabetes mellitus.
Glucagon-like peptide-1 (GLP-1) is an incretin hormone secreted from enteroendocrine L cells in response to ingested nutrients. The first recognized and most important action of GLP-1 is the potentiation of glucose-stimulated insulin secretion in beta-cells, mediated by activation of its seven transmembrane domain G-protein-coupled receptor. In addition to its insulinotropic actions, GLP-1 exerts islet-trophic effects by stimulating replication and differentiation and by decreasing apoptosis of beta-cells. The GLP-1 receptor is expressed in a variety of other tissues important for carbohydrate metabolism, including pancreatic alpha-cells, hypothalamus and brainstem, and proximal intestinal tract. GLP-1 also appears to exert important actions in liver, muscle and fat. Thus, GLP-1 suppresses glucagon secretion, promotes satiety, delays gastric emptying and stimulates peripheral glucose uptake. The impaired GLP-1 secretion observed in type 2 diabetes suggests that GLP-1 plays a role in the pathogenesis of this disorder. Thus, because of its multiple actions, GLP-1 is an attractive therapeutic target for the treatment of type 2 diabetes, and major interest has resulted in the development of a variety of GLP-1 receptor agonists for this purpose. Ongoing clinical trials have shown promising results and the first analogs of GLP-1 are expected to be available in the near future. Topics: Amino Acid Sequence; Animals; Blood Glucose; Diabetes Mellitus; Diabetes Mellitus, Type 2; Dipeptidyl Peptidase 4; Exenatide; Glucagon-Like Peptide 1; Glucagon-Like Peptide-1 Receptor; Homeostasis; Humans; Liraglutide; Maleimides; Molecular Sequence Data; Nitriles; Peptides; Protease Inhibitors; Pyrrolidines; Receptors, Glucagon; Venoms | 2006 |
Dipeptidyl peptidase IV inhibitors: a promising new therapeutic approach for the management of type 2 diabetes.
Glucagon-like peptide-1 is an insulinotropic hormone with antidiabetic potential due to its spectrum of effects, which include glucose-dependent stimulation of insulin and inhibition of glucagon secretion, tropic effects on the pancreatic beta-cells, inhibition of gastric emptying and the reduction of appetite. Glucagon-like peptide-1 is, however, extremely rapidly inactivated by the serine peptidase, dipeptidyl peptidase IV, so that the native peptide is not useful clinically. A new approach to utilise the beneficial effects of glucagon-like peptide-1 in the treatment of type 2 diabetes has been the development of orally active dipeptidyl peptidase IV inhibitors. Preclinical studies have demonstrated that this approach is effective in enhancing endogenous levels of glucagon-like peptide-1, resulting in improved glucose tolerance in glucose-intolerant and diabetic animal models. In recent studies of 3-12 months duration in patients with type 2 diabetes, dipeptidyl peptidase IV inhibitors have proved efficacious, both as monotherapy and when given in combination with metformin. Fasting and postprandial glucose concentrations were reduced, leading to reductions in glycosylated haemoglobin levels, while beta-cell function was preserved. Current information suggests dipeptidyl peptidase IV inhibitors are body weight neutral and are well tolerated. A number of dipeptidyl peptidase IV inhibitors are now in the late stages of clinical development. These have different properties, in terms of their duration of action and anticipated dosing frequency, but data from protracted dosing studies is presently not available to allow comparison of their clinical efficacy. Topics: Diabetes Mellitus, Type 2; Dipeptidyl Peptidase 4; Glucagon-Like Peptide 1; Humans; Protease Inhibitors | 2006 |
Is exenatide advancing the treatment of type 2 diabetes?
Glucagon-like peptide 1 is an intestinal peptide hormone that is secreted in response to food to regulate the postprandial blood glucose concentration. Exendin-4 is a 39-amino acid peptide that acts as an agonist at the glucagon-like peptide 1 receptor. Synthetic exendin-4 (exenatide) has recently been trialled in patients with Type 2 diabetes taking either metformin alone or a combination of metformin and a sulfonylurea. In both trials, exenatide 5 and 10 microg s.c. was shown to improve glycaemic control, with few adverse events. Exenatide represents a new and useful addition to the medicines used to treat Type 2 diabetes. Topics: Diabetes Mellitus, Type 2; Exenatide; Glucagon-Like Peptide 1; Glucagon-Like Peptide-1 Receptor; Humans; Peptides; Receptors, Glucagon; Venoms | 2006 |
[New therapeutic approach in patients with type 2 diabetes based on glucagon-like peptide 1 (GLP-1) and gastric inhibitory peptide (GIP)].
Inadequate secretion of insulin is a very early element in the development of type 2 diabetes and its progression is due to declining beta-cell function. This beta-cell defect is partly related to beta-cell loss, but endocrine regulation of islet function could also be involved. A number of recent studies have highlighted the role of the so-called incretin hormones glucagon-like peptide 1 (GLP-1) and gastric inhibitory peptide (GIP) in beta-cell function and development. Up to two- thirds of the insulin normally secreted in connection with meal intake is thought to be due to the insulinotropic actions of these hormones. Although patients with type 2 diabetes have been demonstrated to exhibit an almost total loss of incretin effect, the glucose-lowering actions of exogenous GLP-1 are well preserved. New therapeutic strategies under investigation include the search for novel agents able to utilize the incretin axis in patients with type 2 diabetes. Two strategies have been applied: the first is treatment with GLP-1, either with chronic infusions or with analogues with diminished clearance, and the second is inhibiting dipeptidyl peptidase IV, the enzyme that inactivates both GLP-1 and GIP in vivo. Inhibition of DP- IV has been shown to raise circulating active incretin levels and thus increase the effective concentrations of these peptides reaching target tissues. Apart from their glucose-dependent manner of stimulating insulin secretion, GLP-1, its analogues, and GIP have been demonstrated to stimulate beta-cell growth, differentiation, proliferation, and survival. Similarly, studies in both humans and in animal models have established DP-IV inhibition as a promising therapeutic approach for the treatment of type 2 diabetes, resulting in an enhancement of glucose tolerance, insulin sensitivity, and beta-cell glucose responsiveness. Topics: Animals; Diabetes Mellitus, Type 2; Dipeptidyl Peptidase 4; Disease Progression; Enzyme Activation; Gastric Inhibitory Polypeptide; Glucagon-Like Peptide 1; Humans; Insulin-Secreting Cells | 2006 |
Glucagon-like peptide-1: from extract to agent. The Claude Bernard Lecture, 2005.
The incretin hormones are intestinal polypeptides that enhance postprandial insulin secretion. Gastric inhibitory polypeptide (GIP) was initially thought to regulate gastric acid secretion, whereas glucagon-like peptide-1 (GLP-1) was discovered as a result of a systematic search for intestinal insulinotropic products of proglucagon gene expression. The incretin effect is markedly impaired or absent in patients with type 2 diabetes because of decreased secretion of GLP-1 and a loss of the insulinotropic effects of GIP. Metabolic control can be restored or greatly improved by administration of exogenous GLP-1, but this peptide is almost immediately degraded by dipeptidyl peptidase IV (DPP-IV), and therefore has little clinical value. DPP-IV-resistant analogues (incretin mimetics) have been identified or developed, and inhibitors of DPP-IV have also proved effective in protecting endogenous GLP-1 (and GIP) from degradation. Both principles have been tested in clinical studies. The incretin mimetics, administered by sc injection, have demonstrated lasting improvement in HbA(1)c in patients insufficiently treated with conventional oral therapy, and their use has been associated with steady weight loss for up to 2 years. The DPP-IV inhibitors, given once or twice daily by mouth, also appear to provide lasting improvement in HbA(1)c, but are weight-neutral. The first incretin mimetic has reached the market in the US, and applications for approval of the first inhibitors are expected to be filed early in 2006. Topics: Blood Glucose; Diabetes Mellitus, Type 2; Dipeptidyl Peptidase 4; Exenatide; Gastric Inhibitory Polypeptide; Glucagon-Like Peptide 1; Glucagon-Like Peptide-1 Receptor; Glycated Hemoglobin; Humans; Hypoglycemic Agents; Injections, Subcutaneous; Insulin; Insulin Secretion; Intestines; Peptides; Protease Inhibitors; Receptors, Glucagon; Venoms | 2006 |
Applications of dipeptidyl peptidase IV inhibitors in diabetes mellitus.
A number of alternative therapies for type 2 diabetes are currently under development that take advantage of the actions of the incretin hormones glucagon-like peptide-1 and glucose-dependent insulinotropic polypeptide on the pancreatic beta-cell. One such approach is based on the inhibition of dipeptidyl peptidase IV (DP IV), the major enzyme responsible for degrading the incretins in vivo. DP IV exhibits characteristics that have allowed the development of specific inhibitors with proven efficacy in improving glucose tolerance in animal models of diabetes and type 2 human diabetics. While enhancement of insulin secretion, resulting from blockade of incretin degradation, has been proposed to be the major mode of inhibitor action, there is also evidence that inhibition of gastric emptying, reduction in glucagon secretion and important effects on beta-cell differentiation, mitogenesis and survival, by the incretins and other DP IV-sensitive peptides, can potentially preserve beta-cell mass, and improve insulin secretory function and glucose handling in diabetics. Topics: Amino Acid Sequence; Animals; Diabetes Mellitus; Diabetes Mellitus, Type 1; Diabetes Mellitus, Type 2; Dipeptidyl Peptidase 4; Gastric Inhibitory Polypeptide; Glucagon; Glucagon-Like Peptide 1; Glucagon-Like Peptides; Glucose; Glucose Tolerance Test; Humans; Molecular Sequence Data; Peptide Fragments; Protease Inhibitors | 2006 |
Emerging therapies mimicking the effects of amylin and glucagon-like peptide 1.
Topics: Amyloid; Blood Glucose; Diabetes Mellitus, Type 2; Glucagon-Like Peptide 1; Glucagon-Like Peptide-1 Receptor; Humans; Hypoglycemic Agents; Islet Amyloid Polypeptide; Receptors, Glucagon | 2006 |
Therapeutic intervention in the GLP-1 pathway in Type 2 diabetes.
Topics: Administration, Oral; Diabetes Mellitus, Type 2; Diabetic Angiopathies; Dipeptidyl Peptidase 4; Enzyme Inhibitors; Glucagon-Like Peptide 1; Glucagon-Like Peptide-1 Receptor; Humans; Hypoglycemic Agents; Injections, Subcutaneous; Receptors, Glucagon; Weight Loss | 2006 |
Incretin mimetics and dipeptidyl peptidase-IV inhibitors: potential new therapies for type 2 diabetes mellitus.
The emergence of the glucoregulatory hormones glucagon-like peptide-1 (GLP-1) and glucose-dependent insulinotropic polypeptide has expanded our understanding of glucose homeostasis. In particular, the glucoregulatory actions of the incretin hormone GLP-1 include enhancement of glucosedependent insulin secretion, suppression of inappropriately elevated glucagon secretion, slowing of gastric emptying, and reduction of food intake. Two approaches have been developed to overcome rapid degradation of GLP-1. One is the use of agents that mimic the enhancement of glucose-dependent insulin secretion, and potentially other antihyperglycemic actions of incretins, and the other is the use of dipeptidyl peptidase-IV inhibitors, which reduce the inactivation of GLP-1, increasing the concentration of endogenous GLP-1. The development of incretin mimetics and dipeptidyl peptidase-IV inhibitors opens the door to a new generation of antihyperglycemic agents to treat several otherwise unaddressed pathophysiologic defects of type 2 diabetes mellitus. We review the physiology of glucose homeostasis, emphasizing the role of GLP-1, the pathophysiology of type 2 diabetes mellitus, the clinical shortcomings of current therapies, and the potential of new therapies -- including the newly approved incretin mimetic exenatide -- that elicit actions similar to those of GLP-1. Topics: Diabetes Mellitus, Type 2; Dipeptidyl Peptidase 4; Enzyme Inhibitors; Glucagon-Like Peptide 1; Glucose; Homeostasis; Hypoglycemic Agents | 2006 |
The biology of incretin hormones.
Gut peptides, exemplified by glucagon-like peptide-1 (GLP-1) and glucose-dependent insulinotropic polypeptide (GIP) are secreted in a nutrient-dependent manner and stimulate glucose-dependent insulin secretion. Both GIP and GLP-1 also promote beta cell proliferation and inhibit apoptosis, leading to expansion of beta cell mass. GLP-1, but not GIP, controls glycemia via additional actions on glucose sensors, inhibition of gastric emptying, food intake and glucagon secretion. Furthermore, GLP-1, unlike GIP, potently stimulates insulin secretion and reduces blood glucose in human subjects with type 2 diabetes. This article summarizes current concepts of incretin action and highlights the potential therapeutic utility of GLP-1 receptor agonists and dipeptidyl peptidase-4 (DPP-4) inhibitors for the treatment of type 2 diabetes. Topics: Animals; Diabetes Mellitus, Type 2; Gastric Inhibitory Polypeptide; Gastrointestinal Hormones; Glucagon-Like Peptide 1; Pancreas | 2006 |
New therapies for type 2 diabetes based on glucagon-like peptide 1.
Cells in the gastrointestinal tract secrete several hormones that stimulate insulin secretion, one of which is glucagon-like peptide (GLP-1). Several new drugs act through the GLP-1 signaling system to stimulate insulin release and regulate blood glucose levels in patients with diabetes. One such compound, exenatide (Byetta), has recently become available, and others are in clinical development. Topics: Diabetes Mellitus, Type 2; Glucagon-Like Peptide 1; Humans; Hypoglycemic Agents | 2006 |
Dipeptidyl peptidase-IV inhibitors can restore glucose homeostasis in type 2 diabetics via incretin enhancement.
Incretin levels approach normal physiological values following treatment with dipeptidyl peptidase (DPP)-IV inhibitors. This is in contrast to incretin levels resulting from the exogenous administration of glucagon-like peptide (GLP)-1 and its analogs, which can reach super-physiological values. This review describes the role of DPP-IV inhibitors as incretin enhancers in the regulation of glucose homeostasis in type 2 diabetic patients. The roles of incretins and the effect of DPP-IV on their actions are described, as are new therapeutic interventions based on the restoration of impaired incretin secretion in type 2 diabetic patients and obese individuals. In addition, the relevance of DPP-IV inhibition for weight control, its potential influence on beta-cell mass, and possible new indications are discussed, as are the implications of the currently available clinical data. Topics: Animals; Blood Glucose; Body Weight; Clinical Trials as Topic; Diabetes Mellitus, Type 2; Dipeptidyl Peptidase 4; Gastric Inhibitory Polypeptide; Glucagon-Like Peptide 1; Homeostasis; Humans; Insulin-Secreting Cells; Protease Inhibitors | 2006 |
From cradle to grave: pancreatic beta-cell mass and glucagon-like peptide-1.
Type 2 diabetes mellitus and its clinical correlates, including impaired fasting blood glucose, obesity and insulin resistance, represent a significant public health issue worldwide, with the prevalence of these metabolic conditions increasing exponentially. Given the staggering financial costs and human suffering incurred by diabetes and its co-morbid conditions, any safe new therapeutic interventions that prove to have a beneficial effect in reducing the incidence of diabetes in susceptible individuals or in preventing progression of the disease would have major public health benefits. Studies on the regulation of beta-cell mass have demonstrated a remarkable plasticity, from fetal through adult life, as well as in response to a variety of stresses. These findings are considered in this review in the context of newer studies on the intestinal hormone, glucagon-like peptide-1, which not only enhances beta-cell function, but also stimulates beta-cell growth, neogenesis and survival. Topics: Adult; Apoptosis; Cell Proliferation; Diabetes Mellitus, Type 2; Glucagon-Like Peptide 1; Humans; Insulin-Secreting Cells | 2006 |
Therapies for the treatment of type 2 diabetes mellitus based on incretin action.
Orally ingested glucose leads to a much higher insulin response than intravenous glucose leading to identical postprandial plasma glucose excursions. This phenomenon, termed ''incretin effect'' comprises up to 60% of the postprandial insulin secretion and is diminished in type 2 diabetes. The gastrointestinal hormones glucagon-like peptide-1 (GLP-1) and gastric inhibitory polypeptide (GIP) promote the incretin effect. Type 2 diabetes is characterized by an incretin defect: while GIP does not stimulate insulin secretion, GLP-1 action is still preserved under supraphysiological concentrations. GLP-1 stimulates insulin secretion only under hyperglycaemic conditions, therefore it does not cause hypoglycaemia. Furthermore, GLP-1 inhibits glucagon secretion and delays gastric emptying. In vitro and animal data demonstrated that GLP-1 increases beta cell mass by stimulating islet cell neogenesis and by inhibiting apoptosis of islets. The improvement of beta cell function can be indirectly observed from the increased insulin secretory capacity of humans receiving GLP-1. In contrast to GIP, GLP-1 may represent an attractive therapeutic method for type 2 diabetes due to its multiple effects also including the simulation of satiety in the central nervous system by acting as transmitter or by crossing the blood brain barrier. Native GLP-1 is degraded rapidly upon intravenous or subcutaneous administration and is therefore not feasible for routine therapy. Long-acting GLP-1 analogs (e.g. Liraglutide) and exendin-4 (Exenatide, Byetta) that are resistant to degradation, called ''incretin mimetics'' are approved (Exenatide, Byetta) or in clinical trials. DPP-4-inhibitors (e.g. Vildagliptin), Sitagliptin and Saxagliptin) that inhibit the enzyme DPP-4 responsible for incretin degradation are also under study. Topics: Animals; Clinical Trials as Topic; Diabetes Mellitus, Type 2; Glucagon; Glucagon-Like Peptide 1; Humans; Hypoglycemic Agents; Insulin-Secreting Cells; Protein Synthesis Inhibitors; Satiety Response | 2006 |
Relative contribution of incretins to the glucose lowering effect of DP IV inhibitors in type 2 diabetes mellitus (T2DM).
Topics: Animals; Blood Glucose; Carbohydrates; Diabetes Mellitus, Type 2; Dipeptidyl Peptidase 4; Drug Therapy, Combination; Gastric Inhibitory Polypeptide; Glucagon-Like Peptide 1; Humans; Insulin; Intestinal Absorption; Serine Proteinase Inhibitors; Signal Transduction | 2006 |
Ileal transposition provides insight into the effectiveness of gastric bypass surgery.
Despite dramatically increased research efforts to discover cures for the rising health issue of obesity, bariatric (obesity) surgery remains the most effective treatment. Obese people and especially those classified as morbidly obese often suffer from associated co-morbid conditions such as type-II diabetes. In most cases, bariatric surgery results in rapid and sustained decreases in excess body weight. Recent reports have identified significant improvements in glucose homeostasis after surgery that are coincident and often precedent to any measurable weight loss. These studies suggest an inhibition or enhancement of a "factor" within the intestinal tract that improves glycemia independent of body fat stores. These observations have sparked renewed investigation into the mechanisms underlying successful obesity surgeries such as gastric bypass. It is becoming increasingly clear that restriction and malabsorption are not the only two mechanisms important for inducing long-term weight loss or the improvements in diabetes. Investigating the hypothesis that the distal intestine (ileum) holds additional answers into a third mechanism, I used the model of ileal transposition to help identify endocrine changes in the gut following obesity surgery. This review will explore the model of ileal transposition and speculate on its usefulness as a tool to dissect out additional mechanisms underlying effective obesity surgeries. Also discussed will be the ileal-produced hormone glucagon-like peptide and its role in mediating the improvements in diabetes and weight loss after bariatric surgery. Topics: Adaptation, Physiological; Adiposity; Anastomosis, Surgical; Animals; Diabetes Mellitus, Type 2; Gastric Bypass; Glucagon-Like Peptide 1; Humans; Ilium; Models, Animal; Obesity; Weight Loss | 2006 |
Incretin mimetics and dipeptidyl peptidase-IV inhibitors: a review of emerging therapies for type 2 diabetes.
Type 2 diabetes is thought to develop as a result of progressive beta-cell dysfunction in the setting of insulin resistance, leading to increased risks of microvascular and macrovascular complications. Type 2 diabetes is currently treated with diet and exercise, followed by oral drug therapy, and finally exogenous insulin. While this approach is known to improve glycemic control, none of the currently available therapies significantly improve beta-cell function. In addition, this approach does not address defects in hormonal secretion thought to play key roles in the pathophysiology of type 2 diabetes. Type 2 diabetes is characterized by excess glucagon secretion and insufficient secretion of the hormone amylin from the pancreatic beta-cell. In addition, individuals with type 2 diabetes demonstrate insufficient secretion of the incretin hormone glucagon-like peptide-1 (GLP-1). Novel therapies that leverage the so-called "incretin effect" of GLP-1 (including the incretin mimetics and dipeptidyl peptidase-IV (DPP-IV) inhibitors) are being actively developed for the management of type 2 diabetes. Incretin mimetics are either derivatives of GLP-1, modified to resist proteolysis, or are novel peptides that share glucoregulatory functions with GLP-1 and are naturally resistant to proteolysis. DPP-IV inhibitors enhance the concentration of endogenous GLP-1 by limiting proteolysis of native GLP-1. With the approval of exenatide- the first "incretin mimetic"-treatment of type 2 diabetes will no doubt be changed. An understanding of the effects of these compounds will be needed to enhance the clinical approach to diabetes treatment. Topics: Diabetes Mellitus, Type 2; Dipeptidyl Peptidase 4; Glucagon-Like Peptide 1; Humans; Hypoglycemic Agents; Insulin; Insulin Secretion; Metformin; Protease Inhibitors | 2006 |
Investigational treatments for Type 2 diabetes mellitus: exenatide and liraglutide.
Although a number of compounds are currently used to treat Type 2 diabetes mellitus, achieving a sustained glycaemic control over time is often not possible using oral antidiabetics. Endogenous incretins exhibit beneficial effects that could be useful for Type 2 diabetes mellitus treatment, such as stimulating insulin secretion during hyperglycaemia, improving beta-cell mass and function, reducing glucagon secretion, delaying gastric emptying, reducing postprandial hyperglycaemia and diminishing body weight; however, their short half-life makes them unsuitable for treatment. Incretin mimetics such as liraglutide and exenatide were developed to overcome this limitation. This review discusses the effects of these compounds and their potential as a new class of antidiabetic agents. Topics: Animals; Blood Glucose; Body Weight; Cell Proliferation; Diabetes Mellitus, Type 2; Drugs, Investigational; Exenatide; Gastric Emptying; Glucagon; Glucagon-Like Peptide 1; Humans; Hypoglycemic Agents; Insulin; Insulin-Secreting Cells; Liraglutide; Peptides; Randomized Controlled Trials as Topic; Venoms | 2006 |
Exenatide: an incretin mimetic for the treatment of type 2 diabetes mellitus.
Exenatide is a subcutaneously injected incretin mimetic. It is indicated as adjunctive therapy to improve glycemic control in patients with type 2 diabetes mellitus (T2DM) who are already receiving therapy with metformin, a sulfonylurea, or both but continue to have suboptimal glycemic control.. This article reviews available information on the clinical pharmacology, comparative efficacy, tolerability, drug interactions, contraindications and precautions, dosage and administration, availability and storage, and cost of exenatide.. MEDLINE (1966-April 2006) and Web of Science (1995-April 2006) were searched for original research and review articles published in the English language. The search terms used were exenatide, exendin-4, glucagon-Like peptide-1, GLP-1, and incretin mimetic. The reference lists of identified articles were also consulted, as was selected information from the package insert for exenatide. All relevant comparative efficacy studies that were available in published form were included in the review.. Naturally occurring incretins, such as glucagon-like peptide-1 (GLP-1), exhibit insulinotropic properties after release into the circulation from the gut. As a GLP-1 agonist, exenatide improves glucose homeostasis by mimicking the actions of naturally occurring GLP-1. It improves glycemic control by reducing fasting and postprandial glucose concentrations through a combination of known mechanisms, including glucose-dependent insulin secretion, restoration of first-phase insulin response, regulation of glucagon secretion, delaying gastric emptying, and decreasing food intake. Three Phase III comparative efficacy trials were identified that enrolled a total of 1,446 patients who received exenatide 5 pg SC BID, exenatide 10 mug SC BID, or placebo for 30 weeks in addition to their existing therapy with metformin, sulfonylurea, or both. In these trials, the addition of exenatide was associated with significant reductions in glycosylated hemoglobin (HbA(1c)) values (P < 0.001-P < 0.002), greater proportions of patients achieving an HbA(1c) Topics: Blood Glucose; Diabetes Mellitus, Type 2; Exenatide; Fasting; Glucagon-Like Peptide 1; Glycated Hemoglobin; Humans; Hypoglycemic Agents; Injections, Subcutaneous; Insulin; Metformin; Peptides; Sulfonylurea Compounds; Venoms | 2006 |
The treatment of type 2 diabetes mellitus in youth : which therapies?
Type 2 diabetes mellitus in children and adolescents is becoming an increasingly important public health concern throughout the world. This epidemic is closely associated with the increased prevalence of obesity among youth of all ethnic backgrounds, as increased visceral adipose tissue produces adipokines that increase insulin resistance. Type 2 diabetes represents one arm of the metabolic syndrome, which includes abdominal obesity, disturbed glucose regulation and insulin resistance, dyslipidemia, and hypertension. The treatment of type 2 diabetes and the metabolic syndrome poses a challenge for pediatric endocrinologists. This review provides information regarding diagnosis of type 2 diabetes in children, as well as prevention strategies, such as lifestyle modification and pharmacologic options for weight loss, including metformin, orlistat, and sibutramine. Pharmacologic treatment options, their modes of action, and clinical indications for use are also reviewed. Treatment regimens for youth-onset type 2 diabetes that are discussed include metformin, sulfonylureas, glucosidase inhibitors, thiazolidinediones, glucagon-like peptide-1, and insulin. Topics: Adipose Tissue; Adolescent; Diabetes Mellitus, Type 2; Glucagon-Like Peptide 1; Humans; Hypoglycemic Agents; Metformin; Obesity; Thiazolidinediones; Weight Loss | 2006 |
Incretins and the development of type 2 diabetes.
The incretin hormones gastric inhibitory polypeptide (GIP) and glucagon-like peptide 1 (GLP-1) are released in response to nutrient ingestion and potentiate glucose-stimulated insulin secretion from pancreatic beta cells. The augmentation of postprandial insulin secretion by such gastrointestinal hormones is called the incretin effect. The incretin effect is almost completely absent in patients with type 2 diabetes. This is due to 1) an approximate 15% reduction in postprandial GLP-1 secretion and 2) a near total loss of insulinotropic activity of GIP. This review article summarizes clinical studies on abnormalities in the secretion and insulinotropic effects of GIP and GLP-1 in patients with type 2 diabetes as well as in individuals at high risk. A significant proportion of first-degree relatives are characterized by a reduced insulinotropic response to exogenous GIP. Nevertheless, this phenomenon does not predispose to a more rapid deterioration in glucose tolerance or conversion to impaired glucose tolerance or diabetes. Therefore, although there are hints of early abnormalities in incretin secretion and action in prediabetic populations, it has not been proven that such phenomena are central to the pathogenesis of type 2 diabetes. Topics: Animals; Diabetes Mellitus, Type 2; Gastric Inhibitory Polypeptide; Glucagon-Like Peptide 1; Humans; Hypoglycemic Agents; Insulin; Insulin Secretion | 2006 |
GLP-1 and type 2 diabetes: physiology and new clinical advances.
The first antidiabetic treatment (exenatide; Byetta) based on the incretin hormone glucagon-like peptide-1 (GLP-1) was approved in 2005 as an adjunctive therapy in diabetic patients in whom sulfonylurea, metformin or both had failed. Many GLP-1 mimetics or dipeptidyl peptidase IV inhibitors are currently in clinical development for the treatment of type 2 diabetes and show promising results in the improvement of glucose homeostasis. Furthermore, the ability of GLP-1 to enhance pancreatic beta-cell mass could delay progression of the disease. However, only several years of treatment in humans will confirm the long-term efficacy of GLP-1 mimetics and enhancers on glycemic control. To take advantage of the multifaceted actions of GLP-1, a better understanding of the physiological roles of GLP-1 is required. Topics: Cell Proliferation; Diabetes Mellitus, Type 2; Glucagon-Like Peptide 1; Glucose; Homeostasis; Humans; Insulin; Insulin Secretion; Insulin-Secreting Cells; Models, Biological; Salvage Therapy | 2006 |
Management of Type 2 diabetes: the role of incretin mimetics.
Type 2 diabetes is characterised by insulin resistance and progressive beta-cell dysfunction (which leads to hyperglycaemia), the risk of progressive worsening of glycaemic control and an increased risk of both macrovascular and microvascular complications. Existing treatment strategies target deficient insulin secretion and insulin resistance, but do not generally address the underlying progressive beta-cell dysfunction that is common to Type 2 diabetes. Traditionally, Type 2 diabetes is first treated with medical nutrition therapy (reduced food intake and increased physical activity), followed by stepwise addition of oral antidiabetes therapies and, ultimately, exogenous insulin, as required. Unfortunately, these approaches have not been shown to delay the need for additional therapies, nor do they generally prevent or delay the inexorable decline in beta-cell function. Patients with Type 2 diabetes commonly experience deterioration in glycaemic control, and may have substantial weight gain due to the diabetes therapies that contribute to worsening obesity. In addition, insulin-providing therapies, such as sulfonylureas and exogenous insulin, carry the risk of hypoglycaemia, and cannot fully address the complex hormonal irregularities that characterise Type 2 diabetes, including the role of glucagon hypersecretion. New therapeutic approaches are being developed that couple durable glycaemic control with improved control of body weight. These approaches include development of the incretin mimetics, which are a novel class of agents that share several of the glucoregulatory effects of incretin hormones, such as glucagon-like hormone-1. Deficiency of glucagon-like hormone-1 secretion is known to be present in those with abnormal glucose tolerance. Agents that manipulate the physiological actions of incretin hormones, such as glucagon-like hormone-1, may significantly benefit patients with Type 2 diabetes. Topics: Diabetes Mellitus, Type 2; Dipeptidyl-Peptidases and Tripeptidyl-Peptidases; Exenatide; Glucagon-Like Peptide 1; Humans; Insulin; Insulin Secretion; Maleimides; Peptides; Venoms | 2006 |
[Incretins].
Insulin secretion is greater after peroral challenge than after intravenous glucose administration due to so-called incretin effect. The major incretins are glucagon-like peptide 1 and glucose-dependent-insulinotropic peptide. Physiology, pathophysiology and therapeutic implications of incretins in diabetes, neurodegenerative disorders and stress-induced hyperglycemia are concerned. Topics: Animals; Diabetes Mellitus, Type 2; Gastric Inhibitory Polypeptide; Glucagon-Like Peptide 1; Humans; Hyperglycemia; Insulin; Insulin Secretion | 2006 |
How do different GLP-1 mimetics differ in their actions?
Glucagon-like peptide-1 (GLP-1) mimetics have been developed to overcome the pharmacokinetic limitations of GLP-1 for the treatment of type 2 diabetes. Their mechanisms of action and clinical effects appear particularly interesting because they target the main pathophysiologic mechanisms involved in type 2 diabetes. GLP-1 receptor agonists are more powerful and are particularly advantageous by their weight loss-inducing capacity, whereas dipeptidyl peptidase IV inhibitors exhibit a better tolerance profile. However, their ultimate role is still to be defined in the therapeutic strategy of type 2 diabetes. Topics: Adamantane; Diabetes Mellitus, Type 2; Dipeptidyl Peptidase 4; Dipeptidyl-Peptidase IV Inhibitors; Exenatide; Glucagon-Like Peptide 1; Humans; Hypoglycemic Agents; Liraglutide; Nitriles; Peptides; Pyrrolidines; Venoms; Vildagliptin | 2006 |
Modulation of cyclic nucleotides and cyclic nucleotide phosphodiesterases in pancreatic islet beta-cells and intestinal L-cells as targets for treating diabetes mellitus.
Cyclic 3'5'-AMP (cAMP) is an important physiological amplifier of glucose-induced insulin secretion by the pancreatic islet beta-cell. In the beta-cell, cAMP is formed by the activity of adenylyl cyclase, especially in response to the incretin hormones glucagon-like peptide (GLP)-1 and glucose-dependent insulinotropic peptide. cAMP may also play a similar role in regulating GLP-1 secretion from intestinal L-cells. cAMP influences many steps involved in glucose-induced insulin secretion and may be important in regulating pancreatic islet beta-cell differentiation, growth and survival. cAMP itself is rapidly degraded in the pancreatic islet beta-cell by cyclic nucleotide phosphodiesterase enzymes. This review will discuss the possibility of targeting cAMP mechanisms in the treatment of type 2 diabetes mellitus, in which insulin release in response to glucose is impaired. Topics: 2',3'-Cyclic-Nucleotide Phosphodiesterases; Animals; Cyclic AMP; Cyclic GMP; Diabetes Mellitus, Type 2; Dipeptidyl Peptidase 4; Gastric Inhibitory Polypeptide; Glucagon-Like Peptide 1; Humans; Insulin-Secreting Cells; Intestinal Mucosa; Intestines; Phosphodiesterase Inhibitors; Protease Inhibitors | 2006 |
The incretin system: glucagon-like peptide-1 receptor agonists and dipeptidyl peptidase-4 inhibitors in type 2 diabetes.
Glucagon-like peptide 1 (GLP-1) is a gut-derived incretin hormone that stimulates insulin and suppresses glucagon secretion, inhibits gastric emptying, and reduces appetite and food intake. Therapeutic approaches for enhancing incretin action include degradation-resistant GLP-1 receptor agonists (incretin mimetics), and inhibitors of dipeptidyl peptidase-4 (DPP-4) activity (incretin enhancers). Clinical trials with the incretin mimetic exenatide (two injections per day or long-acting release form once weekly) and liraglutide (one injection per day) show reductions in fasting and postprandial glucose concentrations, and haemoglobin A1c (HbA1c) (1-2%), associated with weight loss (2-5 kg). The most common adverse event associated with GLP-1 receptor agonists is mild nausea, which lessens over time. Orally administered DPP-4 inhibitors, such as sitagliptin and vildagliptin, reduce HbA1c by 0.5-1.0%, with few adverse events and no weight gain. These new classes of antidiabetic agents, and incretin mimetics and enhancers, also expand beta-cell mass in preclinical studies. However, long-term clinical studies are needed to determine the benefits of targeting the incretin axis for the treatment of type 2 diabetes. Topics: Adamantane; Adenosine Deaminase Inhibitors; Clinical Trials as Topic; Diabetes Mellitus, Type 2; Dipeptidyl Peptidase 4; Dipeptidyl-Peptidase IV Inhibitors; Drug Administration Schedule; Exenatide; Glucagon-Like Peptide 1; Glucagon-Like Peptide-1 Receptor; Glycoproteins; Humans; Hypoglycemic Agents; Liraglutide; Nitriles; Peptides; Pyrazines; Pyrrolidines; Receptors, Glucagon; Sitagliptin Phosphate; Triazoles; Venoms; Vildagliptin | 2006 |
Exenatide in type 2 diabetes: treatment effects in clinical studies and animal study data.
The therapeutic options for treating type 2 diabetes have been widened by the introduction of exenatide as the first incretin mimetic. Incretins are gut hormones that contribute to the stimulation of insulin secretion after a carbohydrate rich meal. The incretin hormone glucagon-like peptide-1 (GLP-1) not only stimulates insulin secretion under hyperglycaemic conditions, but also suppresses glucagon secretion, slows gastric emptying, induces satiety and improves beta cell function in type 2 diabetes. These beneficial effects have awakened the interest to use GLP-1 for the treatment of type 2 diabetes. Because of its short biological half-life, GLP-1 itself is not practical for type 2 diabetes therapy. Exenatide is a peptide found in the lizard Heloderma suspectum and has a high similarity to GLP-1. Exenatide belongs to the novel class of incretin mimetics because of its incretin-like action. It has a much longer biological half life than GLP-1 and is a GLP-1 receptor agonist that can be used for therapeutic purposes by twice daily injection. Clinical studies and clinical experience with exenatide have shown a significant reduction in HbA1c, fasting- and postprandial glucose and a marked reduction in body weight in type 2 diabetic patients. Animal studies reveal an improvement of beta cell function and an increase in beta cell mass after exenatide treatment. This review gives an overview on exenatide, its pharmacological profile and its role and potential in the therapeutic setting of type 2 diabetes. Furthermore, future developments concerning exenatide application are highlighted. Topics: Animals; Clinical Trials as Topic; Delayed-Action Preparations; Diabetes Mellitus, Type 2; Exenatide; Glucagon-Like Peptide 1; Humans; Hypoglycemic Agents; Lizards; Peptides; Rodentia; Venoms | 2006 |
Dipeptidyl peptidase IV (DPP IV) inhibitors: A newly emerging drug class for the treatment of type 2 diabetes.
Inhibitors of the enzyme dipeptidyl peptidase IV (DPP IV) provide a strategy for the treatment of type 2 diabetes. DPP IV rapidly inactivates the incretin hormones glucagon-like peptide-1 (GLP-1) and glucose-dependent insulinotropic polypeptide (GIP). Inhibition of DPP IV prolongs and enhances the activity of endogenous GLP-1 and GIP, which serve as important prandial stimulators of insulin secretion and regulators of blood glucose control. In clinical trials DPP IV inhibitors (or 'gliptins') have shown efficacy and tolerability in the management of hyperglycaemia in type 2 diabetes, without causing weight gain or hypoglycaemia. Topics: Adamantane; Adenosine Deaminase; Adenosine Deaminase Inhibitors; Animals; Blood Glucose; Clinical Trials as Topic; Diabetes Mellitus, Type 2; Dipeptidyl Peptidase 4; Dipeptidyl-Peptidase IV Inhibitors; Drug Evaluation, Preclinical; Gastric Inhibitory Polypeptide; Glucagon-Like Peptide 1; Glycoproteins; Humans; Hypoglycemic Agents; Isoenzymes; Nitriles; Protease Inhibitors; Pyrazines; Pyrrolidines; Sitagliptin Phosphate; Triazoles; Vildagliptin | 2006 |
[Glucagon-like peptide-1 based therapy for type 2 diabetes].
Topics: Child; Diabetes Mellitus, Type 2; Glucagon-Like Peptide 1; Humans; Incretins; Treatment Outcome | 2006 |
Metabolic effects of the incretin mimetic exenatide in the treatment of type 2 diabetes.
Interventional studies have demonstrated the impact of hyperglycemia on the development of vascular complications associated with type 2 diabetes, which underscores the importance of safely lowering glucose to as near-normal as possible. Among the current challenges to reducing the risk of vascular disease associated with diabetes is the management of body weight in a predominantly overweight patient population, and in which weight gain is likely with many current therapies. Exenatide is the first in a new class of agents termed incretin mimetics, which replicate several glucoregulatory effects of the endogenous incretin hormone, glucagon-like peptide-1 (GLP-1). Currently approved in the US as an injectable adjunct to metformin and/or sulfonylurea therapy, exenatide improves glycemic control through multiple mechanisms of action including: glucose-dependent enhancement of insulin secretion that potentially reduces the risk of hypoglycemia compared with insulin secretagogues; restoration of first-phase insulin secretion typically deficient in patients with type 2 diabetes; suppression of inappropriately elevated glucagon secretion to reduce postprandial hepatic output; and slowing the rate of gastric emptying to regulate glucose appearance into the circulation. Clinical trials in patients with type 2 diabetes treated with subcutaneous exenatide twice daily demonstrated sustained improvements in glycemic control, evidenced by reductions in postprandial and fasting glycemia and glycosylated hemoglobin (HbA(1c)) levels. Notably, improvements in glycemic control with exenatide were coupled with progressive reductions in body weight, which represents a distinct therapeutic benefit for patients with type 2 diabetes. Acute effects of exenatide on beta-cell responsiveness along with significant reductions in body weight in patients with type 2 diabetes may have a positive impact on disease progression and potentially decrease the risk of associated long-term complications. Topics: Blood Glucose; Body Weight; Cardiovascular Diseases; Diabetes Mellitus, Type 2; Diabetic Angiopathies; Exenatide; Glucagon-Like Peptide 1; Glycated Hemoglobin; Humans; Hypoglycemic Agents; Insulin; Insulin-Secreting Cells; Molecular Mimicry; Obesity; Peptides; Treatment Outcome; Venoms | 2006 |
Incretin-based therapies for type 2 diabetes: clinical utility.
Topics: Diabetes Mellitus, Type 2; Glucagon-Like Peptide 1; Humans; Hypoglycemic Agents | 2006 |
Incretin mimetics as emerging treatments for type 2 diabetes.
To review the physiology, pharmacology, and clinical efficacy of glucagon-like peptide (GLP-1) and the incretin mimetics exenatide and liraglutide in clinical studies.. Primary literature obtained via MEDLINE (1966-April 2004) and International Pharmaceutical Abstracts (1970-April 2004) searches; abstracts obtained from meeting sources and manufacturers.. All English-language studies and abstracts evaluating GLP-1, exenatide, and liraglutide in the treatment of patients with type 2 diabetes were reviewed. Data from animal studies were also included if human data were not available. Primary and review articles related to the physiology, development, and evaluation of GLP-1s were reviewed.. GLP-1, exenatide (exendin-4, AC2993), and liraglutide (NN2211) are incretin mimetics that have been shown in human studies to be an effective treatment to improve glycemic control in patients with type 2 diabetes. Mechanisms by which these compounds improve glycemic control include enhancing glucose-dependent pancreatic secretion of insulin in response to nutrient intake, inhibiting glucagon secretion, delaying gastric emptying, and promoting early satiety. GLP-1 has been shown to promote pancreatic progenitor cell differentiation and improve beta-cell function and lifespan. Reported adverse effects of exenatide and liraglutide include nausea, vomiting, and transient headache, as well as increased risk of hypoglycemia when used with sulfonylureas.. Clinical studies show that GLP-1, exenatide, and liraglutide improve glycemic control for patients with type 2 diabetes through unique mechanisms not available with current pharmaceutical products. Ongoing Phase III studies will help to further position these compounds as treatment options for patients with type 2 diabetes. Topics: Animals; Clinical Trials as Topic; Diabetes Mellitus, Type 2; Exenatide; Glucagon; Glucagon-Like Peptide 1; Humans; Hypoglycemic Agents; Liraglutide; Peptide Fragments; Peptides; Protein Precursors; Venoms | 2005 |
Unique characteristics of the geriatric diabetic population and the role for therapeutic strategies that enhance glucagon-like peptide-1 activity.
Care for elderly diabetic patients poses a unique clinical challenge. This review highlights distinct aspects of the pathophysiology and the risks for secondary complications in the geriatric diabetic population. Based on these considerations, we discuss emerging therapeutic options based on the actions of the incretin hormone glucagon-like peptide (GLP)-1, which may be ideal for achieving glycemic control in the elderly diabetic patient.. Aging is associated with diminished capacity of pancreatic beta-cells to respond to glucose. This functional decline in beta-cell insulin secretion is a major contributor to the development of diabetes in the older patient. In addition, elderly diabetics suffer from a broader range of diabetic complications than do younger diabetics, warranting aggressive glycemic control. GLP-1 is known to improve beta-cell insulin secretion, increase beta-cell mass, and suppress glucagon secretion. Recent studies investigating improved GLP-1 activity have yielded promising results, with improved glycemic control in elderly patients with type 2 diabetes and without significant risk for hypoglycemia.. Elderly diabetics are a growing subset of the type 2 diabetic population with unique pathophysiologic characteristics and diabetic risk profiles. Therapeutic strategies that incorporate enhancement of GLP-1 action on beta-cells to improve beta-cell insulin secretion and glycemic control may be ideal for this distinct population and should be validated with further long-term clinical studies. Topics: Aged; Aging; Blood Glucose; Diabetes Mellitus, Type 2; Geriatrics; Glucagon; Glucagon-Like Peptide 1; Humans; Insulin; Insulin Secretion; Islets of Langerhans; Peptide Fragments; Protein Precursors | 2005 |
Islet adaptation to insulin resistance: mechanisms and implications for intervention.
Insulin sensitivity and insulin secretion are reciprocally related such that insulin resistance is adapted by increased insulin secretion to maintain normal glucose and lipid homeostasis. The relation between insulin sensitivity and secretion is curvilinear and mathematically best described as a hyperbolic relation. Several potential mediators have been suggested to be signals for the beta cells to respond to insulin resistance such as glucose, free fatty acids, autonomic nerves, fat-derived hormones and the gut hormone glucagon-like peptide-1 (GLP-1). Failure of these signals or of the pancreatic beta cells to adequately adapt insulin secretion in relation to insulin sensitivity results in inappropriate insulin levels, impaired glucose intolerance (IGT) and type 2 diabetes. Therefore, treatment of IGT and type 2 diabetes should aim at restoring the normal relation between insulin sensitivity and secretion. Such treatment includes stimulation of insulin secretion (sulphonylureas, repaglinide and nateglinide) and insulin sensitivity (metformin and thiazolidinediones), as well as treatment aimed at supporting the signals mediating the islet adaptation (cholinergic agonists and GLP-1). Both, for correct understanding of diabetes pathophysiology and for development of novel treatment modalities, therefore, the non-linear inverse relation between insulin sensitivity and secretion needs to be acknowledged. Topics: Adaptation, Physiological; Animals; Blood Glucose; Cholinergic Agonists; Diabetes Mellitus, Type 2; Glucagon; Glucagon-Like Peptide 1; Humans; Hypoglycemic Agents; Insulin; Insulin Resistance; Insulin Secretion; Islets of Langerhans; Metformin; Peptide Fragments; Protein Precursors; Sulfonylurea Compounds | 2005 |
Diabetes outfoxed by GLP-1?
Foxo1, a member of the Fox0 subfamily of winged-helix forkhead transcription factors, is a target of insulin and insulin-like growth factor-1 (IGF-1) signal transduction pathways that activate protein kinase B (PKB) in pancreatic beta cells. Foxo1 is a substrate for PKB, and its phosphorylation results in nuclear exclusion with concomitant alterations in gene expression that are important to cellular growth and differentiation. Because activation of PKB can require insulin receptor substrate proteins (IRS-1 and IRS-2) and phosphatidylinositol 3-kinase (PI3K), it is of interest to determine whether the activity of Foxo1 is also regulated by heterotrimeric G protein-coupled receptors (GPCRs) with IRS-1 or -2, PI3K, or PKB signaling potential. Indeed, studies of beta cells have demonstrated that activation of a GPCR for the blood glucose-lowering hormone GLP-1 leads to major alterations of IRS-2, PI3K, and PKB activity. By promoting nuclear exclusion of Foxo1 in a PKB-mediated manner, GLP-1 may up-regulate the expression of a homeodomain transcription factor (PDX-1) that serves as a master regulator of beta-cell growth and differentiation. This STKE Perspective summarizes signaling properties of GLP-1 that may explain its ability to increase beta-cell mass, to increase pancreatic insulin secretory capacity, and to lower levels of blood glucose in type 2 diabetic subjects. Topics: Animals; Diabetes Mellitus, Experimental; Diabetes Mellitus, Type 2; Glucagon-Like Peptide 1; Glucagon-Like Peptide-1 Receptor; Homeodomain Proteins; Humans; Hyperplasia; Insulin; Insulin Receptor Substrate Proteins; Insulin Secretion; Intracellular Signaling Peptides and Proteins; Islets of Langerhans; Mice; Mice, Knockout; Models, Biological; Phosphoproteins; Proto-Oncogene Proteins c-akt; Rats; Receptors, Glucagon; Secretory Rate; Signal Transduction; Trans-Activators | 2005 |
Therapeutic assessment of glucagon-like peptide-1 agonists compared with dipeptidyl peptidase IV inhibitors as potential antidiabetic drugs.
The most prevalent form of diabetes is non-insulin-dependent or Type 2 diabetes. Innovative strategies to enhance insulin secretion and thereby improve glucose tolerance in patients with this type of diabetes are currently under preclinical and clinical investigation. These therapies include the applications of incretin hormones; gut hormones released postprandially that stimulate insulin secretion in pancreatic beta-cells. Because incretin actions are rapidly terminated by N-terminal cleavage of these peptide hormones by the amino-peptidase dipeptidyl peptidase IV (DPP IV, CD26), the utility of DPP IV inhibitors for the treatment of Type 2 diabetes is also under investigation. This review compares the therapeutic potential and possible side effects of metabolically stable analogues/peptide agonists of the incretin glucagon-like peptide-1 (GLP-1) with the application of DPP IV inhibitors that reduce the rate of endogenous degradation of GLP-1 and other incretins. GLP-1 analogues have been shown to be highly efficacious in the treatment of Type 2 diabetes, with minimal side effects. Of particular importance is the fact that they do not induce hypoglycaemia. However, they are currently available only in an injectable form. In contrast, DPP IV inhibitors have the clear advantage of oral application resulting in better patient compliance. Furthermore, they also potentiate the actions of other incretins normally degraded by the action of DPP IV. However, they possess more potential side effects. Taken together, both approaches offer promising new drugs for the treatment of Type 2 diabetes. Topics: Animals; Diabetes Mellitus, Type 2; Dipeptidyl Peptidase 4; Glucagon-Like Peptide 1; Humans; Hypoglycemic Agents; Protease Inhibitors | 2005 |
Novel pharmacologic agents for type 2 diabetes.
After many decades of relative therapeutic stagnation since the initial discovery of insulin, followed by some modifications on its structure and only having sulfonylureas and biguanides for many years, the last decade has seen a surge in new therapeutic options for the management of diabetes. The results of the United Kingdom Prospective Diabetes Study and Kumamoto study indicate the need for aggressive glycemic control and the slow inexorable clinical deterioration associated with type 2 diabetes overtime. The propensity for weight gain and hypoglycemia are the two major limitations that subcutaneous insulin and sulfonylureas have been particularly prone to. The newer antidiabetic medications and those on the horizon attempt to address these limitations. GLP-1 agonists and the DPP-IV inhibitors exploit the innate incretin system to improve glycemia while promoting satiety and weight management. Like GLP-1 related compounds, pramlintide offers the potential to address postprandial hyperglucagonemia associated with type 2 diabetes only limited by the multiple injections and gastrointestinal side effects. The glitazars offer the hope ofa new approach to diabetes care addressing not just glycemia, but dyslipidemia and other components of the metabolic syndrome, though the side effect profile remains a major unknown. The INGAP peptide represents the holy grail of diabetes care as it offers the potential of a new paradigm: that of islet regeneration and potential for a cure. But at this stage, with no human data available, it remains highly speculative. Beyond these and other novel agents being developed to meet the challenge of the worldwide epidemic of diabetes, the central place of insulin in diabetes care cannot be forgotten. In view of this the continued efforts of improvement in insulin delivery, kinetics and action have spurred such innovations as the various inhaled insulins and new insulin analogues. There is cause for guarded optimism and excitement about the years ahead. There is reason to expect that despite the growing burden of diabetes worldwide, we will be better equipped to manage it and its comorbidities and prevent its onset and possibly even cure it. Topics: Amyloid; Antigens, Neoplasm; Biomarkers, Tumor; Clinical Trials as Topic; Diabetes Mellitus, Type 2; Dipeptidyl Peptidase 4; Glucagon; Glucagon-Like Peptide 1; Humans; Hypoglycemic Agents; Insulin; Insulin Detemir; Insulin, Long-Acting; Islet Amyloid Polypeptide; Lectins, C-Type; Pancreatitis-Associated Proteins; Peptide Fragments; Polymers; Protein Precursors; Thiazolidinediones | 2005 |
Glucagon-related peptide 1 (GLP-1): hormone and neurotransmitter.
The interest in glucagon-like petide-1 (GLP-1) and other pre-proglucagon derived peptides has risen almost exponentially since seminal papers in the early 1990s proposed to use GLP-1 agonists as therapeutic agents for treatment of type 2 diabetes. A wealth of interesting studies covering both normal and pathophysiological role of GLP-1 have been published over the last two decades and our understanding of GLP-1 action has widened considerably. In the present review, we have tried to cover our current understanding of GLP-1 actions both as a peripheral hormone and as a central neurotransmitter. From an initial focus on glycaemic control, GLP-1 research has been diverted to study its role in energy homeostasis, neurodegeneration, cognitive functions, anxiety and many more functions. With the upcoming introduction of GLP-1 agonists on the pharmaceutical venue, we have witnessed an outstanding example of how initial ideas from basic science laboratories have paved their way to become a novel therapeutic strategy to fight diabetes. Topics: Diabetes Mellitus, Type 2; Gastrointestinal Hormones; Glucagon; Glucagon-Like Peptide 1; Humans; Hypoglycemic Agents; Neurotransmitter Agents; Peptide Fragments; Proglucagon; Protein Precursors | 2005 |
GIP and GLP-1 as incretin hormones: lessons from single and double incretin receptor knockout mice.
Glucose-dependent insulinotropic polypeptide (GIP) and glucagon-like peptide-1 (GLP-1) are gut-derived incretins secreted in response to nutrient ingestion. Both incretins potentiate glucose-dependent insulin secretion and enhance beta-cell mass through regulation of beta-cell proliferation, neogenesis and apoptosis. In contrast, GLP-1, but not GIP, inhibits gastric emptying, glucagon secretion, and food intake. Furthermore, human subjects with Type 2 diabetes exhibit relative resistance to the actions of GIP, but not GLP-1R agonists. The physiological importance of both incretins has been investigated through generation and analysis of incretin receptor knockout mice. Elimination of incretin receptor action in GIPR-/- or GLP-1R-/- mice produces only modest impairment in glucose homeostasis. Similarly, double incretin receptor knockout (DIRKO) mice exhibit normal body weight and normal levels of plasma glucagon and hypoglycemic responses to exogenous insulin. However, glucose-stimulated insulin secretion is significantly decreased following oral but not intraperitoneal glucose challenge in DIRKO mice and the glucose lowering actions of dipeptidyl peptidase-IV (DPP-IV) inhibitors are extinguished in DIRKO mice. Hence, incretin receptor signaling exerts physiologically relevant actions critical for glucose homeostasis, and represents a pharmacologically attractive target for development of agents for the treatment of Type 2 diabetes. Topics: Animals; Diabetes Mellitus, Type 2; Gastric Inhibitory Polypeptide; Gastrointestinal Hormones; Glucagon; Glucagon-Like Peptide 1; Glucagon-Like Peptide-1 Receptor; Glucose; Humans; Mice; Mice, Knockout; Pancreas; Peptide Fragments; Protein Precursors; Receptors, Gastrointestinal Hormone; Receptors, Glucagon | 2005 |
Glucagon-like peptide 1 and its derivatives in the treatment of diabetes.
Glucagon-like peptide 1 (GLP-1) was discovered as an insulinotropic gut hormone, suggesting a physiological role as an incretin hormone, i.e., being responsible, in part, for the higher insulin secretory response after oral as compared to intravenous glucose administration. This difference, the incretin effect, is partially lost in patients with Type 2 diabetes. The actions of GLP-1 include (a) a stimulation of insulin secretion in a glucose-dependent manner, (b) a suppression of glucagon, (c) a reduction in appetite and food intake, (d) a deceleration of gastric emptying, (e) a stimulation of beta-cell neogenesis, growth and differentiation in animal and tissue culture experiments, and (f) an in vitro inhibition of beta-cell apoptosis induced by different toxins. Intravenous GLP-1 can normalize and subcutaneous GLP-1 can significantly lower plasma glucose in the majority of patients with Type 2 diabetes. GLP-1 itself, however, is inactivated rapidly in vivo and thus does not appear to be useful as a therapeutic agent in the long-term treatment of Type 2 diabetes. Other agents acting on GLP-1 receptors have been found (like exendin-4) or developed as GLP-1 derivatives (like liraglutide or GLP-1/CJC-1131). Clinical trials with exenatide (two injections per day) and liraglutide (one injection per day) have shown reductions in glucose concentrations and HbA1c by more than 1%, associated with moderate weight loss (2-3 kg), but also some nausea and, rarely, vomiting. It is hoped that this new class of drugs interacting with the GLP-1 or other incretin receptors, the so-called "incretin mimetics", will broaden our armamentarium of antidiabetic medications in the nearest future. Topics: Amino Acid Sequence; Diabetes Mellitus, Type 2; Glucagon; Glucagon-Like Peptide 1; Glucagon-Like Peptide-1 Receptor; Humans; Hypoglycemic Agents; Molecular Sequence Data; Peptide Fragments; Protein Precursors; Receptors, Glucagon | 2005 |
Dipeptidyl peptidase IV inhibitors: how do they work as new antidiabetic agents?
A number of new approaches to diabetes therapy are currently undergoing clinical trials, including those involving stimulation of the pancreatic beta-cell with the gut-derived insulinotropic hormones (incretins), GIP and GLP-1. The current review focuses on an approach based on the inhibition of dipeptidyl peptidase IV (DP IV), the major enzyme responsible for degrading the incretins in vivo. The rationale for this approach was that blockade of incretin degradation would increase their physiological actions, including the stimulation of insulin secretion and inhibition of gastric emptying. It is now clear that both GIP and GLP-1 also have powerful effects on beta-cell differentation, mitogenesis and survival. By potentiating these pleiotropic actions of the incretins, DP IV inhibition can therefore preserve beta-cell mass and improve secretory function in diabetics. Topics: Diabetes Mellitus, Type 2; Dipeptidyl Peptidase 4; Gastric Inhibitory Polypeptide; Glucagon; Glucagon-Like Peptide 1; Humans; Hypoglycemic Agents; Peptide Fragments; Protease Inhibitors; Protein Precursors | 2005 |
Changes in insulin resistance following bariatric surgery: role of caloric restriction and weight loss.
The prevalence of type 2 diabetes mellitus (T2DM) and obesity in the western world is steadily increasing. Bariatric surgery is an effective treatment of T2DM in obese patients. The mechanism by which weight loss surgery improves glucose metabolism and insulin resistance remains controversial. In this review, we propose that two mechanisms participate in the improvement of glucose metabolism and insulin resistance observed following weight loss and bariatric surgery: caloric restriction and weight loss. Nutrients modulate insulin secretion through the entero-insular axis. Fat mass participates in glucose metabolism through the release of adipocytokines. T2DM improves after restrictive and bypass procedures, and combinations of restrictive and bypass procedures in morbidly obese patients. Restrictive procedures decrease caloric and nutrient intake, decreasing the stimulation of the entero-insular axis. Gastric bypass (GBP) operations may also affect the entero-insular axis by diverting nutrients away from the proximal GI tract and delivering incompletely digested nutrients to the distal GI tract. GBP and biliopancreatic diversion combine both restrictive and bypass mechanisms. All procedures lead to weight loss and decrease in the fat mass. Decrease in fat mass significantly affects circulating levels of adipocytokines, which favorably impact insulin resistance. The data reviewed here suggest that all forms of weight loss surgery lead to caloric restriction, weight loss, decrease in fat mass and improvement in T2DM. This suggests that improvements in glucose metabolism and insulin resistance following bariatric surgery result in the short-term from decreased stimulation of the entero-insular axis by decreased caloric intake and in the long-term by decreased fat mass and resulting changes in release of adipocytokines. Observed changes in glucose metabolism and insulin resistance following bariatric surgery do not require the posit of novel regulatory mechanisms. Topics: Biomarkers; Blood Glucose; Body Mass Index; Caloric Restriction; Diabetes Mellitus, Type 2; Energy Metabolism; Female; Gastric Bypass; Gastric Inhibitory Polypeptide; Ghrelin; Glucagon; Glucagon-Like Peptide 1; Humans; Insulin Resistance; Male; Obesity, Morbid; Peptide Fragments; Peptide Hormones; Prognosis; Protein Precursors; Treatment Outcome; Weight Loss | 2005 |
Enhancing central nervous system endogenous GLP-1 receptor pathways for intervention in Alzheimer's disease.
Glucagon-like peptide-1 (7-36)--amide (GLP-1) is an endogenous insulinotropic peptide that is secreted from the gastrointestinal tract in response to food. It enhances pancreatic islet beta-cell proliferation, glucose-dependent insulin secretion, and lowers blood glucose and food intake in patients with type 2 diabetes mellitus. GLP-1 receptors, are coupled to the cyclic AMP second messenger pathway, and are expressed throughout the brain of rodents and humans. We previously reported that GLP-1 and exendin-4, a naturally occurring, long-acting analogue of GLP-1 that binds the GLP-1 receptor (GLP-1R), possess neurotrophic properties. GLP-1R agonists protect neurons against amyloid-beta peptide (Abeta) and glutamate-induced apoptosis in cell culture studies and attenuate cholinergic neuron atrophy in the basal forebrain of the rat following an excitotoxic lesion. The biochemical cascades activated by neural GLP-1R stimulation are discussed in comparison to those activated by pancreatic receptors, and, additionally, are compared to signaling pathways associated with the classical neurotrophins. GLP-1R stimulation promotes pathways that favour cell survival over apoptosis. GLP-1 readily enters brain, and its diverse physiological actions, which include insulinotropic, cardiovascular as well as neurotrophic ones, may prove beneficial in a variety of diseases prevalent in aging, including Alzheimer's disease (AD). Its ability to lower brain levels of Abeta in mice would appear to be particularly pertinent in this regard. Furthermore, the ready availability of clinical material and the clinical history of its long term use in subjects with type 2 diabetes would support testing the value of GLP-1R agonists in AD trials. Topics: Alzheimer Disease; Animals; Brain; Diabetes Mellitus, Type 2; Glucagon; Glucagon-Like Peptide 1; Humans; Nerve Degeneration; Peptide Fragments; Protein Precursors; Risk Factors; Signal Transduction | 2005 |
The incretin effect and its potentiation by glucagon-like peptide 1-based therapies: a revolution in diabetes management.
The incretin effect is a phenomenon in which enteral glucose administration provokes greater insulin secretion than intravenous administration. The main incretins, glucose-dependent insulinotropic peptide and glucagon-like peptide (GLP)-1 are defective in Type 2 diabetes; whereas glucose-dependent insulinotropic peptide displays diminished effectiveness, GLP-1 secretion is decreased; thus, GLP-1 was a stronger candidate for a new class of anti-diabetic agents designed to potentiate the incretin effect. In the past decade, GLP-1 mimetics, peptidase inhibitors and GLP-1 have been developed. Early randomised trials show that these agents contribute to glucose homeostasis and enhance beta-cell function, without causing hypoglycaemia or weight gain. This review includes an historical perspective, physiology of incretins, and discussions of the pathophysiology in Type 2 diabetes, pharmacology of the main agents and randomised clinical trials published to date. Topics: Animals; Clinical Trials as Topic; Diabetes Mellitus, Type 2; Disease Management; Glucagon-Like Peptide 1; Humans; Peptide Fragments | 2005 |
[Therapeutic potential of DPP-IV inhibitor for the treatment of Type 2 diabetes].
Topics: Diabetes Mellitus, Type 2; Dipeptidyl Peptidase 4; Glucagon; Glucagon-Like Peptide 1; Humans; Nitriles; Peptide Fragments; Protein Precursors; Pyrrolidines | 2005 |
Glucagon-like peptide-1 as a treatment option for type 2 diabetes and its role in restoring beta-cell mass.
The "incretin effect" describes the enhanced insulin response from orally ingested glucose compared with intravenous glucose leading to identical postprandial plasma glucose excursions. It makes up to 60% of the postprandial insulin secretion but is diminished in type 2 diabetes. Gastrointestinal hormones promoting the incretin effect are called incretins. Glucagon-like peptide- 1 (GLP-1) is an important incretin. In vitro and animal data have demonstrated that GLP-1 increases beta-cell mass by stimulating islet cell neogenesis and by inhibiting apoptosis of islets. The improvement of beta-cell function can be indirectly observed from the increased insulin secretory capacity of humans receiving GLP-1 or incretin mimetics that act like GLP-1. Furthermore, GLP-1 inhibits glucagon secretion and rarely causes hypoglycemia. It may represent an attractive therapeutic method for type 2 diabetes because of its multiple effects, including a slowing of gastric emptying and the simulation of satiety by acting as a transmitter in the CNS. Native GLP-1 is degraded rapidly upon intravenous or subcutaneous administration and is therefore not feasable for routine therapy. Long-acting GLP-1 analogs (e.g., Liraglutide [Novo Nordisk, Copenhagen, Denmark]) and exenadin-4 (Exenatide [Eli Lilly, Indianapolis, IN]) that are resistant to degradation, called "incretin mimetics," are being investigated in clinical trials. Dipeptidyl peptidase IV inhibitors (e.g., Vildagliptin [Novartis, Basel, Switzerland]) that inhibit the enzyme responsible for incretin degradation are also under study. Topics: Amino Acid Sequence; Animals; Diabetes Mellitus, Type 2; Glucagon; Glucagon-Like Peptide 1; Humans; Islets of Langerhans; Mice; Models, Biological; Molecular Sequence Data; Peptide Fragments; Protein Precursors; Satiation | 2005 |
Incretin mimetics: promising new therapeutic options in the treatment of type 2 diabetes.
To review the current state of diabetes treatment from a clinical and management perspective and explore the role that new biologic pharmaceuticals may offer patients who fail to meet or maintain glycemic goals with existing treatment options.. Key clinical areas involve the role that insulin resistance and beta-cell dysfunction/failure play in the progression of type 2 diabetes as well as current treatment modalities and how they address those core defects. Management issues include a discussion of the economics of the disease and the implications of the United Kingdom Prospective Diabetes Study (UKPDS)--that good glucose control reduces the occurrence of microvascular complications and improves quality of life for diabetic patients. While an intensive approach may be costly in the short term, statistics on the rising pandemic of the disease argue compellingly for early and aggressive treatment to delay fatal complications and improve the quality of life for persons suffering from type 2 diabetes. Current pharmaceutical regimens are not successfully enabling patients with type 2 diabetes to reach glycemic goals. The ramifications of this failure have profound repercussions in the managed care organization environment. Fortunately, new treatment modalities are in various stages of development. These will be reviewed with a more in-depth exploration of the potential of incretin mimetics, a new biologic, injectable class of drugs for the treatment of type 2 diabetes. Emphasis will be given to exenatide, an incretin mimetic that demonstrates particular efficacy for patients not achieving glycemic goal with oral medications and are insulin naive. Biologics are administered by injection or infusion and are generally costly. Apart from their cost, however, what is even more critical to managed care executives and decision makers is that these medications indicate a trend in pharmacotherapy, a groundswell of new medications. In addition, few practitioners and even fewer health care executives understand molecular medicine. The key message is that making formulary decisions about these pharmaceuticals will become more pressing every year.. Managed care executives will be faced with the significant challenge of investing their limited resources in the most clinically and fiscally responsible manner within a milieu of ever increasing pharmacologic options that could significantly strain budgets and result in less than optimal patient outcomes. Topics: Adamantane; Chemistry, Pharmaceutical; Diabetes Mellitus, Type 2; Exenatide; Glucagon-Like Peptide 1; Humans; Hypoglycemic Agents; Peptides; Pyrrolidines; Venoms | 2005 |
Biological actions of the incretins GIP and GLP-1 and therapeutic perspectives in patients with type 2 diabetes.
Incretin hormones are defined as intestinal hormones released in response to nutrient ingestion, which potentiate the glucose-induced insulin response. In humans, the incretin effect is mainly caused by two peptide hormones, glucose-dependent insulin releasing polypeptide GIP, and glucagon-like peptide-1 GLP-1. GIP is secreted by K cells from the upper small intestine while GLP-1 is mainly produced in the enteroendocrine L cells located in the distal intestine. Their effect is mediated through their binding with specific receptors, though part of their biological action may also involve neural modulation. GIP and GLP-1 are both rapidly degraded into inactive metabolites by the enzyme dipeptidyl-peptidase-IV (DPP-IV). In addition to its effects on insulin secretion, GLP-1 exerts other significant actions, including stimulation of insulin biosynthesis, inhibition of glucagon secretion, inhibition of gastric emptying and acid secretion, reduction of food intake, and trophic effects on the pancreas. As the insulinotropic action of GLP-1 is preserved in type 2 diabetic patients, this peptide was a candidate as a therapeutic agent for this disease. A number of pharmacological strategies have been developed to provide continuous delivery of GLP-1 and to prevent degradation of GLP-1, including continuous administration of GLP-1, DPP-IV inhibitors and DPP-IV resistant GLP-1 analogues. Recent results of the most clinically advanced incretin mimetics confirmed their efficacy to improve glycemic control in type 2 diabetic patients. Further results are expected to confirm the efficacy/safety profile of these compounds, and to find their place in the therapeutic strategy of type 2 diabetes. Topics: Diabetes Mellitus, Type 2; Dipeptidyl Peptidase 4; Gastric Inhibitory Polypeptide; Glucagon; Glucagon-Like Peptide 1; Humans; Infusions, Intra-Arterial; Insulin; Insulin Secretion; Intestine, Small; Peptide Fragments; Protein Precursors | 2005 |
Proglucagon-derived peptides: mechanisms of action and therapeutic potential.
Glucagon is used for the treatment of hypoglycemia, and glucagon receptor antagonists are under development for the treatment of type 2 diabetes. Moreover, glucagon-like peptide (GLP)-1 and GLP-2 receptor agonists appear to be promising therapies for the treatment of type 2 diabetes and intestinal disorders, respectively. This review discusses the physiological, pharmacological, and therapeutic actions of the proglucagon-derived peptides, with an emphasis on clinical relevance of the peptides for the treatment of human disease. Topics: Animals; Diabetes Mellitus, Type 2; Dipeptidyl Peptidase 4; Disease; Glucagon; Glucagon-Like Peptide 1; Glucagon-Like Peptide 2; Glucagon-Like Peptide-1 Receptor; Glucagon-Like Peptides; Humans; Intestinal Diseases; Peptide Fragments; Peptides; Proglucagon; Protease Inhibitors; Protein Precursors; Receptors, Glucagon | 2005 |
Glucagon-like peptide-1 derivatives and dipeptidyl peptidase-IV inhibitors. New hope for the treatment of type-2 diabetes.
Glucagon-like peptide GLP-1 is an endogenous insulinotropic/glucagonostatic hormone that acts in a self-limiting mechanism. It is a multifunctional hormone that leads to insulin release stimulation, liver glucagon breakdown suppression, upregulation of islet cell proliferation, and neogenesis and retardation of gastric emptying. The short half-life and high renal clearance due to degradation via dipeptidyl peptidase-IV DPP-IV, and active glomerular filtration rate make this hormone ineffectual as an exogenous agent. More stable and long acting GLP-1 analogues and DPP-1 inhibitors have been developed with promising clinical value for the treatment of type-2 diabetes. The GLP-1 derivatives have the advantage of decreasing body weight while the DPP-IV inhibitors can be administered orally up to once daily. The mechanism of action as well as the tolerable side effect is astounding. This review article covers this new generation of anti-diabetics. Topics: Administration, Oral; Diabetes Mellitus, Type 2; Dipeptidyl Peptidase 4; Female; Glucagon-Like Peptide 1; Humans; Hypoglycemic Agents; Male; Protease Inhibitors; Sensitivity and Specificity; Structure-Activity Relationship | 2005 |
Incretins: what does the future hold?
Topics: Adamantane; Blood Glucose; Body Weight; Diabetes Mellitus, Type 2; Dipeptidyl Peptidase 4; Exenatide; Glucagon-Like Peptide 1; Humans; Liraglutide; Nitriles; Peptides; Protease Inhibitors; Pyrrolidines; Venoms; Vildagliptin | 2005 |
Glucagon-like peptide 1 (GLP-1) and metabolic diseases.
Glucagon-like peptide-1 (GLP-1) is a gastrointestinal hormone, mainly secreted after meals, which enhances glucose-induced insulin secretion and induces satiety. It has been reported that GLP-1 levels after a mixed meal and after an oral glucose load are reduced in patients with Type 2 diabetes. The reduction of oral glucose-stimulated active GLP-1 levels in patients with Type 2 diabetes has also been observed during euglycemic iperinsulinemic clamp. The reduction of post-prandial circulating active GLP-1 in Type 2 diabetic subjects, as a consequence of chronic hyperglycemia, could contribute to the reduction of early post-prandial insulin secretion; in fact, the administration of GLP-1 receptor antagonists to healthy volunteers elicits both an impairment of meal-induced insulin secretion and an increase of post-prandial glycemia similar to that observed in Type 2 diabetes. GLP-1 is rapidly inactivated by dipeptidyl peptidase IV (DPP-IV), an enzyme produced by endothelial cells in different districts and that circulates in plasma. It is still not clear whether the reduction of mealor oral-glucose stimulated GLP-1 levels in Type 2 diabetic patients is due to impairment of secretion, increase of degradation, or both. The major limitation of using GLP-1 to treat diabetic patients is the short half-life of the native compound. There are now several compounds in various stages of pre-clinical or clinical development for the treatment of Type 2 diabetes that utilize the GLP-1 signaling pathway; these include GLP-1 receptor agonists with extended half-lives, and inhibitors of DPP-IV that increase circulating levels of endogenous, intact and bioactive GLP-1. Topics: Diabetes Mellitus, Type 2; Dipeptidyl Peptidase 4; Glucagon-Like Peptide 1; Glucagon-Like Peptide-1 Receptor; Glucose; Humans; Insulin; Obesity; Protease Inhibitors; Receptors, Glucagon | 2005 |
Glucagon-like peptide-1-based therapies for the treatment of type 2 diabetes mellitus.
The 'incretin effect' describes the phenomenon of an enhanced insulin response following oral ingestion of glucose compared with that after intravenous administration of glucose, leading to identical postprandial plasma glucose excursions. It accounts for up to 60% of the postprandial insulin secretion, but is diminished in patients with type 2 diabetes mellitus. Gastrointestinal hormones that promote the incretin effect are called incretins. Glucagon-like peptide-1 (GLP-1) is an important incretin. Under hyperglycemic conditions in humans, it stimulates insulin secretion and normalizes blood glucose levels. GLP-1 does not stimulate insulin secretion at normal glucose levels; therefore, it does not cause hypoglycemia. Furthermore, it inhibits glucagon secretion and delays gastric emptying. In vitro and animal data have demonstrated that GLP-1 increases beta-cell mass by stimulating islet cell neogenesis and by inhibiting the apoptosis of islet cells. The improvement of beta-cell function due to GLP-1 can be indirectly observed from the increased insulin secretory capacity of humans receiving such treatment. GLP-1 may represent an attractive therapeutic method for patients with type 2 diabetes because of its multiple effects, including the simulation of satiety in the CNS by acting as a transmitter or by crossing the blood brain barrier. Native GLP-1 is degraded rapidly upon intravenous or subcutaneous administration and is therefore not feasible for routine therapy. Long-acting GLP-1 analogs (e.g. liraglutide) and exendin-4 (exenatide) that are resistant to degradation, called 'incretin mimetics', are being investigated in clinical trials. Dipeptidyl peptidase-IV inhibitors (e.g. vildagliptin, sitagliptin, and saxagliptin) that inhibit the enzyme responsible for incretin degradation are also being studied. Topics: Animals; Diabetes Mellitus, Type 2; Glucagon; Glucagon-Like Peptide 1; Humans; Insulin-Secreting Cells; Satiety Response | 2005 |
Exenatide.
Exenatide is the first in a new class of compounds that exhibit activity similar to the naturally occurring hormone glucagon-like peptide-1 (GLP-1). Released from cells in the gut in response to food, GLP-1 binds to pancreatic beta-cell receptors to stimulate the release of insulin. Exenatide mirrors many of the effects of GLP-1, improving glycemic control through a combination of mechanisms, which include glucose-dependent stimulation of insulin secretion, suppression of glucagon secretion, slowing of gastric emptying, reduced appetite and enhanced beta-cell function. As stimulation of insulin secretion occurs only in the presence of elevated blood glucose concentrations, the risk of hypoglycemia should be greatly reduced with exenatide. In addition to positive therapeutic effects on fasting and postprandial glucose levels, exenatide treatment is associated with significant, dose-dependent reductions in glycated hemoglobin (HbA1c) from baseline and progressive reductions in body weight. Exenatide is generally well tolerated; nausea is the most commonly reported side effect, but it can be significantly reduced when a target dose of exenatide is achieved in patients with gradual dose titration. Exenatide may enable patients with type 2 diabetes to achieve glycemic control while reducing or eliminating the risk of hypoglycemia and weight gain. These would represent significant therapeutic gains. Topics: Adolescent; Adult; Aged; Blood Glucose; Clinical Trials as Topic; Diabetes Mellitus, Type 2; Exenatide; Gastric Emptying; Glucagon-Like Peptide 1; Half-Life; Humans; Hypoglycemic Agents; Metabolic Clearance Rate; Middle Aged; Nausea; Peptides; Venoms | 2005 |
[Gluco-incretin hormones in insulin secretion].
Nutrient ingestion triggers a complex hormonal response aimed at stimulating glucose utilization in liver, muscle and adipose tissue to minimize the raise in blood glucose levels. Insulin secretion by pancreatic beta cells plays a major role in this response. Although the beta cell secretary response is mainly controlled by blood glucose levels, gut hormones secreted in response to food intake have an important role in potentiating glucose-stimulated insulin secretion. These gluco-incretin hormones are GLP-1 (glucagon-like peptide-1) and GIP (gluco-dependent insulinotropic polypeptide). Their action on pancreatic beta cells depends on binding to specific G-coupled receptors linked to activation of the adenylyl cyclase pathway. In addition to their effect on insulin secretion both hormones also stimulate insulin production at the transcriptional and translational level and positively regulate beta cell mass. Because the glucose-dependent insulinotropic action of GLP-1 is preserved in type 2 diabetic patients, this peptide is now developed as a novel therapeutic drug for this disease. Topics: Animals; Diabetes Mellitus, Type 2; Glucagon; Glucagon-Like Peptide 1; Humans; Insulin; Insulin Secretion; Islets of Langerhans | 2005 |
Pharmacology of exenatide (synthetic exendin-4): a potential therapeutic for improved glycemic control of type 2 diabetes.
Exenatide (synthetic exendin-4), glucagon-like peptide-1 (GLP-1), and GLP-1 analogues have actions with the potential to significantly improve glycemic control in patients with diabetes. Evidence suggests that these agents use a combination of mechanisms which may include glucose-dependent stimulation of insulin secretion, suppression of glucagon secretion, enhancement of beta-cell mass, slowing of gastric emptying, inhibition of food intake, and modulation of glucose trafficking in peripheral tissues. The short in vivo half-life of GLP-1 has proven a significant barrier to continued clinical development, and the focus of current clinical studies has shifted to agents with longer and more potent in vivo activity. This review examines recent exendin-4 pharmacology in the context of several known mechanisms of action, and contrasts exendin-4 actions with those of GLP-1 and a GLP-1 analogue. One of the most provocative areas of recent research is the finding that exendin-4 enhances beta-cell mass, thereby impeding or even reversing disease progression. Therefore, a major focus of this is article an examination of the data supporting the concept that exendin-4 and GLP-1 may increase beta-cell mass via stimulation of beta-cell neogenesis, stimulation of beta-cell proliferation, and suppression of beta-cell apoptosis. Topics: Amino Acid Sequence; Animals; Cell Division; Diabetes Mellitus, Experimental; Diabetes Mellitus, Type 2; Exenatide; Gastric Emptying; Glucagon; Glucagon-Like Peptide 1; Glucagon-Like Peptide-1 Receptor; Humans; Hypoglycemic Agents; Insulin; Insulin Secretion; Islets of Langerhans; Molecular Sequence Data; Nutritional Physiological Phenomena; Peptide Fragments; Peptides; Protein Precursors; Receptors, Glucagon; Venoms | 2004 |
Incretins, insulin secretion and Type 2 diabetes mellitus.
When glucose is taken orally, insulin secretion is stimulated much more than it is when glucose is infused intravenously so as to result in similar glucose concentrations. This effect, which is called the incretin effect and is estimated to be responsible for 50 to 70% of the insulin response to glucose, is caused mainly by the two intestinal insulin-stimulating hormones, glucagon-like peptide-1 (GLP-1) and glucose-dependent insulinotropic polypeptide (GIP). Their contributions have been confirmed in mimicry experiments, in experiments with antagonists of their actions, and in experiments where the genes encoding their receptors have been deleted. In patients with Type 2 diabetes, the incretin effect is either greatly impaired or absent, and it is assumed that this could contribute to the inability of these patients to adjust their insulin secretion to their needs. In studies of the mechanism of the impaired incretin effect in Type 2 diabetic patients, it has been found that the secretion of GIP is generally normal, whereas the secretion of GLP-1 is reduced, presumably as a consequence of the diabetic state. It might be of even greater importance that the effect of GLP-1 is preserved whereas the effect of GIP is severely impaired. The impaired GIP effect seems to have a genetic background, but could be aggravated by the diabetic state. The preserved effect of GLP-1 has inspired attempts to treat Type 2 diabetes with GLP-1 or analogues thereof, and intravenous GLP-1 administration has been shown to be able to near-normalize both fasting and postprandial glycaemic concentrations in the patients, perhaps because the treatment compensates for both the impaired secretion of GLP-1 and the impaired action of GIP. Several GLP-1 analogues are currently in clinical development and the reported results are, so far, encouraging. Topics: Animals; Diabetes Mellitus, Type 2; Gastric Inhibitory Polypeptide; Glucagon; Glucagon-Like Peptide 1; Humans; Insulin; Insulin Secretion; Peptide Fragments; Protein Precursors | 2004 |
Gut peptides in the treatment of diabetes mellitus.
It has been known for at least one century that agents secreted from the intestine during meal absorption regulates glucose assimilation. Extensive research during the past three decades has identified two gut hormones, glucagon-like peptide-1 (GLP-1) and glucose-dependent insulinotropic peptide (GIP, also known as gastric inhibitory polypeptide) that are important in postprandial glucose metabolism. Both peptides are incretins; they are secreted during carbohydrate absorption and increase insulin secretion. Since they are potent insulin secretagogues, GIP and GLP-1 have received considerable attention as potential diabetes therapeutics. However, only GLP-1 exerts insulinotropic properties when administered to patients with Type 2 diabetes. Both GLP-1 and GIP are rapidly inactivated in the circulation by the enzyme dipeptidyl peptidase IV (DPP-IV). The application of GLP-1 into clinical practice has been delayed due to the need to develop compounds that overcome this rapid inactivation. Two approaches have been taken to utilise the insulinotropic and glucose-lowering actions of GLP-1 as an antidiabetic agent: the development of DPP-IV-resistant analogues and the inhibition of DPP-IV. This review focuses on the physiology of GLP-1 and GIP and the advances that have been made thus far in developing treatments based on these physiological incretins for Type 2 diabetes. Topics: Animals; Diabetes Mellitus; Diabetes Mellitus, Type 2; Dipeptidyl Peptidase 4; Gastric Inhibitory Polypeptide; Gastrointestinal Hormones; Glucagon; Glucagon-Like Peptide 1; Glucagon-Like Peptide-1 Receptor; Humans; Hypoglycemic Agents; Peptide Fragments; Peptide Hormones; Protease Inhibitors; Protein Precursors; Receptors, Gastrointestinal Hormone; Receptors, Glucagon | 2004 |
Potential therapies mimicking the effects of glucagon-like peptide-1 for the treatment of type 2 diabetes.
Topics: Diabetes Mellitus, Type 2; Exenatide; Glucagon; Glucagon-Like Peptide 1; Humans; Hypoglycemic Agents; Liraglutide; Peptide Fragments; Peptides; Protein Precursors; Venoms | 2004 |
Novel strategies for the pharmacological management of type 2 diabetes.
Type 2 diabetes is characterized by high concentrations of glucose in the blood, which is caused by decreased secretion of insulin from the pancreas and decreased insulin action. This condition is prevalent worldwide and is associated with morbidity and mortality secondary to complications such as myocardial infarction, stroke and end-stage renal disease. The importance of tight control of blood glucose in either preventing or delaying the progression of complications is recognized. Currently, there are many therapeutic options to treat hyperglycemia in type 2 diabetes. However, tight control is difficult to achieve and is often associated with side-effects. Recent advances in understanding insulin secretion, action and signaling have led to the development of new pharmacological agents. In this article, we review new molecules that are promising candidates for the future management of diabetes, focusing on their mechanism of action, efficacy, safety profile and potential benefits compared with pharmacological agents that are available currently. Topics: Diabetes Mellitus, Type 2; Glucagon; Glucagon-Like Peptide 1; Humans; Hypoglycemic Agents; Insulin; Peptide Fragments; Protein Precursors; Receptors, Cytoplasmic and Nuclear; Sulfonylurea Compounds; Transcription Factors | 2004 |
The potential role of glucagon-like peptide 1 in diabetes.
The incretin hormone glucagon-like peptide 1 (GLP-1) has a promising potential for the treatment of type 2 diabetes due to its glucose-dependent insulinotropic and glucagonostatic properties. In addition, the peptide potently decelerates gastric emptying and inhibits appetite, thereby leading to reduced food intake. In animal studies, GLP-1 has been demonstrated to increase B-cell mass via inhibition of apoptosis and stimulation of B-cell replication and neogenesis. However, an in vivo half-life in the range of minutes limits the therapeutic use of the native peptide GLP-1. Different pharmacological approaches to overcome these problems are currently being evaluated. They include the continuous parenteral administration of the peptide via infusion pumps, the inhibition of its in vivo degradation and the generation or use of modified derivatives/analogs of GLP-1 displaying prolonged biological activity. The physiological effects of GLP-1 and its pharmacokinetic limitations will be reviewed here, and the current therapeutic approaches based on GLP-1 discussed. Topics: Animals; Blood Glucose; C-Peptide; Diabetes Mellitus, Type 2; Glucagon; Glucagon-Like Peptide 1; Humans; Injections, Intravenous; Injections, Subcutaneous; Insulin; Peptide Fragments; Protein Precursors | 2004 |
Glucagon-like peptide 1 agonists and the development and growth of pancreatic beta-cells.
Glucagon-like peptide 1 (GLP-1) is an intestine-derived insulinotropic hormone that stimulates glucose-dependent insulin production and secretion from pancreatic beta-cells. Other recognized actions of GLP-1 are to suppress glucagon secretion and hepatic glucose output, delay gastric emptying, reduce food intake, and promote glucose disposal in peripheral tissues. All of these actions are potentially beneficial for the treatment of type 2 diabetes mellitus. Several GLP-1 agonists are in clinical trials for the treatment of diabetes. More recently, GLP-1 agonists have been shown to stimulate the growth and differentiation of pancreatic beta-cells, as well as to exert cytoprotective, antiapoptotic effects on beta-cells. Recent evidence indicates that GLP-1 agonists act on receptors on pancreas-derived stem/progenitor cells to prompt their differentiation into beta-cells. These new findings suggest an approach to create beta-cells in vitro by expanding stem/progenitor cells and then to convert them into beta-cells by treatment with GLP-1. Thus GLP-1 may be a means by which to create beta-cells ex vivo for transplantation into patients with insulinopenic type 1 diabetes and severe forms of type 2 diabetes. Topics: Animals; Cell Division; Diabetes Mellitus, Type 1; Diabetes Mellitus, Type 2; Glucagon; Glucagon-Like Peptide 1; Humans; Islets of Langerhans; Islets of Langerhans Transplantation; Peptide Fragments; Protein Precursors | 2004 |
[Future targets in the treatment of type 2 diabetes].
Prevention and treatment of type 2 diabetes mellitus (T2DM) and the metabolic syndrome represent a major clinical challenge, because effective strategies such as fat restriction and exercise are difficult to implement into diabetes treatment. Based on the increasing knowledge on the pathogenesis of T2DM, new therapeutic approaches are currently under investigation. Potential targets of new therapeutic approaches include: (i) Inhibition of hepatic glucose production, (ii) stimulation of glucose-dependent insulin secretion, (iii) enhancement of insulin signal transduction, and (iv) reduction of body fat mass. Agonists of glucagon-like-peptide 1 (GLP-1) and antagonists of dipeptidylpeptidase IV, which inactivates GLP-1, stimulate glucose-dependent insulin secretion, improve hyperglycemia and are already tested in clinical trials. In humans, glucagon antagonists and an amylin analogue reduce glucagon-dependent glucose production. The glucose-lowering effect of current modulators of lipid oxidation is not pronounced and their use could be limited by side effects. In addition to clinically approved thiazolidendiones, new agonists of the peroxisome proliferator activator receptor gamma (PPAR gamma) as well as combined PPAR alpha/gamma agonists are developed at present. The direct modulation of insulin signal transduction is still limited to experimental studies. Topics: Animals; Clinical Trials as Topic; Diabetes Mellitus, Experimental; Diabetes Mellitus, Type 2; Dipeptidyl-Peptidases and Tripeptidyl-Peptidases; Forecasting; Glucagon; Glucagon-Like Peptide 1; Glucose; Glycated Hemoglobin; Glycogen Synthase Kinase 3; Humans; Hypoglycemic Agents; Insulin; Insulin Secretion; Lipid Peroxidation; Metabolic Syndrome; Mice; Oxazines; Peptide Fragments; Phenylpropionates; Protein Precursors; Rats; Receptor, Insulin; Receptors, Cytoplasmic and Nuclear; Rosiglitazone; Signal Transduction; Thiazolidinediones; Transcription Factors | 2004 |
Treatment of type 2 diabetes mellitus with agonists of the GLP-1 receptor or DPP-IV inhibitors.
Glucagon-like peptide-1 (GLP-1) is a peptide hormone from the gut that stimulates insulin secretion and protects beta-cells, inhibits glucagon secretion and gastric emptying, and reduces appetite and food intake. In agreement with these actions, it has been shown to be highly effective in the treatment of Type 2 diabetes, causing marked improvements in glycaemic profile, insulin sensitivity and beta-cell performance, as well as weight reduction. The hormone is metabolised rapidly by the enzyme dipeptidyl peptidase IV (DPP-IV) and, therefore, cannot be easily used clinically. Instead, resistant analogues of the hormone (or agonists of the GLP-1 receptor) are in development, along with DPP-IV inhibitors, which have been demonstrated to protect the endogenous hormone and enhance its activity. Agonists include both albumin-bound analogues of GLP-1 and exendin-4, a lizard peptide. Clinical studies with exendin have been carried out for > 6 months and have indicated efficacy in patients inadequately treated with oral antidiabetic agents. Orally active DPP-IV inhibitors, suitable for once-daily administration, have demonstrated similar efficacy. Diabetes therapy, based on GLP-1 receptor activation, therefore, appears very promising. Topics: Adenosine Deaminase; Adenosine Deaminase Inhibitors; Afferent Pathways; Animals; Appetite; Diabetes Mellitus, Experimental; Diabetes Mellitus, Type 2; Dipeptidyl Peptidase 4; Drug Therapy, Combination; Exenatide; Glucagon; Glucagon-Like Peptide 1; Glucagon-Like Peptide-1 Receptor; Glycoproteins; Humans; Hypoglycemic Agents; Hypothalamus; Insulin; Insulin Secretion; Intestinal Mucosa; Islets of Langerhans; Liraglutide; Lizards; Maleimides; Mice; Mice, Knockout; Mice, Obese; Peptide Fragments; Peptides; Proglucagon; Protein Precursors; Rats; Rats, Zucker; Receptors, Glucagon; Venoms | 2004 |
The gastrointestinal tract and glucose tolerance.
The development of incretin hormones and incretin analogues for the therapy of diabetes highlights the importance of the gastrointestinal tract in the maintenance of glucose tolerance.. The review focuses on recent information on the role of incretins and their breakdown products on insulin secretion, gastric emptying, and satiety. The importance of gastric emptying and its absorptive potential as well as of dietary composition on gastric emptying and glucose tolerance is highlighted. The concept of a portal glucose sensor in humans has been the subject of some controversy but has been recently revisited.. The gastrointestinal tract plays an important part in glucose tolerance. In this review we have examined how factors altering gastric emptying, insulin secretion in response to meal ingestion, and gastric emptying contribute to the maintenance and deterioration of glucose tolerance. Topics: Blood Glucose; Diabetes Mellitus; Diabetes Mellitus, Type 2; Energy Metabolism; Gastric Emptying; Glucagon; Glucagon-Like Peptide 1; Homeostasis; Humans; Insulin; Insulin Secretion; Peptide Fragments; Protein Precursors | 2004 |
[Glucagon-like peptide-1(GLP-1)].
Glucagon-like peptide-1(GLP-1), an intestinal hormone secreted by L cells in response to luminal nutrients(carbohydrate and fat), enhances glucose-induced insulin secretion. Impairment of glucose-induced insulin secretion in patients with type 2 diabetes can be restored to near-normal by GLP-1 administration. In addition, GLP-1 possesses multiple biological effects which are favorable for the treatment of type 2 diabetes: inhibition of glucagon secretion, slowing of gastric emptying, reduction of appetite and food intake, upregulation of genes essential for insulin secretion(glucokinase, GLUT-2 etc), and beta cell proliferation and differentiation. Some long-acting GLP-1 derivatives which are resistant to the degradation by enzyme dipeptidyl peptidase-IV are currently under the clinical trial and are reportedly promising for the treatment of type 2 diabetes, because of impressive effects on glycemic control, availability by oral administration and very few adverse effects. Topics: Diabetes Mellitus, Type 2; Glucagon; Glucagon-Like Peptide 1; Humans; Peptide Fragments; Protein Precursors | 2004 |
[GIP and GLP-1: multiplicity of regulator mechanisms for insulin secretion].
Topics: Animals; Cell Differentiation; Diabetes Mellitus, Type 2; Gastric Inhibitory Polypeptide; Gene Expression Regulation; Glucagon; Glucagon-Like Peptide 1; Glucagon-Like Peptide-1 Receptor; Glucose; Humans; Insulin; Insulin Secretion; Islets of Langerhans; Mice; Mice, Knockout; Peptide Fragments; Protein Precursors; Receptors, Gastrointestinal Hormone; Receptors, Glucagon; Signal Transduction | 2004 |
Role of incretin hormones in the regulation of insulin secretion in diabetic and nondiabetic humans.
The available evidence suggests that about two-thirds of the insulin response to an oral glucose load is due to the potentiating effect of gut-derived incretin hormones. The strongest candidates for the incretin effect are glucose-dependent insulinotropic polypeptide (GIP) and glucagon-like peptide 1 (GLP-1). In patients with type 2 diabetes, however, the incretin effect is lost or greatly impaired. It is hypothesized that this loss explains an important part of the impaired insulin secretion in patients. Further analysis of the incretin effects in patients has revealed that the secretion of GIP is near normal, whereas the secretion of GLP-1 is decreased. On the other hand, the insulintropic effect of GLP-1 is preserved, whereas the effect of GIP is greatly reduced, mainly because of a complete loss of the normal GIP-induced potentiation of second-phase insulin secretion. These two features, therefore, explain the incretin defect of type 2 diabetes. Strong support for the hypothesis that the defect plays an important role in the insulin deficiency of patients is provided by the finding that administration of excess GLP-1 to patients may completely restore the glucose-induced insulin secretion as well as the beta-cells' sensitivity to glucose. Because of this, analogs of GLP-1 or GLP-1 receptor activations are currently being developed for diabetes treatment, so far with very promising results. Topics: Animals; Diabetes Mellitus, Type 2; Gastric Inhibitory Polypeptide; Gastrointestinal Hormones; Glucagon; Glucagon-Like Peptide 1; Humans; Insulin; Insulin Secretion; Neurosecretory Systems; Peptide Fragments; Peptide Hormones; Protein Precursors | 2004 |
Glucagon-like peptide-1: the basis of a new class of treatment for type 2 diabetes.
Topics: Amino Acid Sequence; Animals; Diabetes Mellitus, Type 2; Glucagon; Glucagon-Like Peptide 1; Humans; Molecular Sequence Data; Peptide Fragments; Protein Precursors; Structure-Activity Relationship | 2004 |
Are we closer to finding the treatment for type 2 diabetes mellitus in morbid obesity? Are the incretins the key to success?
Morbid obesity is a serious health problem associated with disease and mortality. One such disease is non-insulin-dependent diabetes mellitus (NIDDM). Approximately 95% of American diabetics have NIDDM. One of the major causes for type 2 diabetes is obesity. The improvement of diabetes with weight control is not in the earliest description of the disease. However, dietary control of NIDDM is often disappointing. Diet can improve glucose metabolism in obesity, but the improvement usually represents only a portion or a brief return to euglycemia, even when patients appear to be compliant. In contrast, reversal of NIDDM has been much more successfully achieved after bariatric surgery. Intra-abdominal fat deposition is associated with increased plasma concentration of free fatty acids, which reduce insulin sensitivity at both muscular and hepatic sites. The progression of diabetes is heralded by the inability of the beta-cells to maintain their previously high rate of insulin secretion in response to glucose, in the face of insulin resistance. The propensity to develop type 2 diabetes may be genetically determined or triggered by environmental factors. The connection between diabetes and obesity represents a continuum that progresses through different phases in which defective insulin action is the principal problem. At this point, we are unable to correlate the different findings of the many questions that arise, such as: 1) Does the decrease in sensitivity to insulin result from rearrangement of the insulin receptor? 2) Is weight loss the trigger for decrease of insulin resistance? 3) Is rearrangement of part of the intestine a mechanism to trigger the secretion of hormones (incretins) that help in insulin response? 4) Which mechanism controls the insulin resistance? The goal of this paper is to review literature on incretins and address the role of incretins after bariatric surgery. We know very little about the action of incretins in diabetes. We will assess the interaction between the secretion of incretins and bariatric surgery for the cure of diabetes. Topics: Acyl Coenzyme A; Diabetes Mellitus, Type 2; Gastric Inhibitory Polypeptide; Gastrointestinal Hormones; Ghrelin; Glucagon; Glucagon-Like Peptide 1; Humans; Lipolysis; Obesity, Morbid; Peptide Fragments; Peptide Hormones; Peptide YY; Protein Precursors | 2004 |
Therapeutic strategies based on glucagon-like peptide 1.
Glucagon-like peptide (GLP)-1 is an incretin hormone with potent glucose-dependent insulinotropic and glucagonostatic actions, trophic effects on the pancreatic beta-cells, and inhibitory effects on gastrointestinal secretion and motility, which combine to lower plasma glucose and reduce glycemic excursions. Furthermore, via its ability to enhance satiety, GLP-1 reduces food intake, thereby limiting weight gain, and may even cause weight loss. Taken together, these actions give GLP-1 a unique profile, considered highly desirable for an antidiabetic agent, particularly since the glucose dependency of its antihyperglycemic effects should minimize any risk of severe hypoglycemia. However, its pharmacokinetic/pharmacodynamic profile is such that native GLP-1 is not therapeutically useful. Thus, while GLP-1 is most effective when administered continuously, single subcutaneous injections have short-lasting effects. GLP-1 is highly susceptible to enzymatic degradation in vivo, and cleavage by dipeptidyl peptidase IV (DPP-IV) is probably the most relevant, since this occurs rapidly and generates a noninsulinotropic metabolite. Strategies for harnessing GLP-1's therapeutic potential, based on an understanding of factors influencing its metabolic stability and pharmacokinetic/pharmacodynamic profile, have therefore been the focus of intense research in both academia and the pharmaceutical industry. Such strategies include DPP-IV-resistant GLP-1 analogs and selective enzyme inhibitors to prevent in vivo degradation of the peptide. Topics: Amino Acid Sequence; Diabetes Mellitus, Type 2; Dipeptidyl Peptidase 4; Glucagon; Glucagon-Like Peptide 1; Humans; Molecular Sequence Data; Peptide Fragments; Protein Precursors | 2004 |
Gut-derived incretin hormones and new therapeutic approaches.
Topics: Diabetes Mellitus, Type 2; Exenatide; Female; Follow-Up Studies; Forecasting; Gastric Inhibitory Polypeptide; Glucagon; Glucagon-Like Peptide 1; Humans; Male; Peptide Fragments; Peptides; Protein Precursors; Randomized Controlled Trials as Topic; Risk Assessment; Treatment Outcome; Venoms | 2004 |
[Analogs of glucagon-like peptide-1 (GLP-1): an old concept as a new treatment of patients with diabetes mellitus type 2].
Upon ingestion of food, the incretin hormones glucagon-like peptide-1 (GLP-1) and glucose-dependent insulinotropic polypeptide (GIP) are synthesised and secreted by specialised gut cells. GLP-1 is also produced in the pancreatic islets and the central nervous system. Both incretins bind to specific G-protein-coupled receptors that are distributed throughout the body. Incretins potentiate meal-induced insulin production and secretion by the beta-cells and lower the blood glucose level in the presence of hyperglycaemia. GLP-1 and GIP stimulate beta-cell proliferation and differentiation, whereas GLP-1 only inhibits gastric emptying and glucagon secretion, reduces food intake and improves insulin sensitivity. Insulin-resistant and type-2 diabetic patients have an impaired incretin response to meal ingestion. However, the insulinotropic action of exogenous GLP-1, but not that of GIP, is preserved in these subjects. After parenteral administration, GLP-1 has an extremely short duration of action because it is rapidly degraded by the ubiquitous enzyme dipeptidyl peptidase IV (DPPIV). To prolong GLP-1 bioactivity, DPPIV-resistant GLP-1 analogues, DPPIV inhibitors and exenatide, a long-acting synthetic GLP-1 receptor agonist derived from the Gila monster hormone exendin-4, have been developed. Enhancement of incretin action seems a rational and promising option for the treatment of type-2 diabetes. Topics: Diabetes Mellitus, Type 2; Dipeptidyl Peptidase 4; Enzyme Inhibitors; Gastric Inhibitory Polypeptide; Glucagon; Glucagon-Like Peptide 1; Humans; Insulin Resistance; Peptide Fragments; Protein Precursors | 2004 |
Glucagon-like peptide 1 and inhibitors of dipeptidyl peptidase IV in the treatment of type 2 diabetes mellitus.
Proof-of-concept for the efficacy of a glucagon-like peptide 1 (GLP-1)-based therapy of patients with type 2 diabetes was provided in 2002 by means of prolonged continuous subcutaneous infusion of native GLP-1. Since then, several long-acting analogues of GLP-1, as well as inhibitors of dipeptidyl peptidase IV, the enzyme that rapidly inactivates endogenous GLP-1, have demonstrated efficacy in long term clinical trials. Topics: Animals; Diabetes Mellitus, Type 2; Dipeptidyl Peptidase 4; Glucagon; Glucagon-Like Peptide 1; Humans; Peptide Fragments; Protease Inhibitors; Protein Precursors; United Kingdom | 2004 |
Clinical endocrinology and metabolism. Glucagon-like peptide-1 and glucagon-like peptide-2.
The glucagon-like peptides (glucagon-like peptide-1 (GLP-1) and glucagon-like peptide-2 (GLP-2)) are released from enteroendocrine cells in response to nutrient ingestion. GLP-1 enhances glucose-stimulated insulin secretion and inhibits glucagon secretion, gastric emptying and feeding. GLP-1 also has proliferative, neogenic and antiapoptotic effects on pancreatic beta-cells. More recent studies illustrate a potential protective role for GLP-1 in the cardiovascular and central nervous systems. GLP-2 is an intestinal trophic peptide that stimulates cell proliferation and inhibits apoptosis in the intestinal crypt compartment. GLP-2 also regulates intestinal glucose transport, food intake and gastric acid secretion and emptying, and improves intestinal barrier function. Thus, GLP-1 and GLP-2 exhibit a diverse array of metabolic, proliferative and cytoprotective actions with important clinical implications for the treatment of diabetes and gastrointestinal disease, respectively. This review will highlight our current understanding of the biology of GLP-1 and GLP-2, with an emphasis on both well-characterized and more novel therapeutic applications of these peptides. Topics: Animals; Cardiovascular Physiological Phenomena; Diabetes Mellitus, Type 2; Feeding Behavior; Glucagon; Glucagon-Like Peptide 1; Glucagon-Like Peptide 2; Glucose; Humans; Nervous System Physiological Phenomena; Peptide Fragments; Peptides; Protein Precursors | 2004 |
[Oral diabetes treatment. Which substance is indicated at which time?].
The prevalence of type 2 diabetes continues to show a clear upward trend in Germany. In earlier days it was considered the "harmless diabetes of old age," but has become increasingly recognized as a disease carrying a high risk of vascular sequelae as well as shortening the diabetic's remaining life expectancy if adequate therapy is not initiated. In addition to correcting hyperglycemia, treatment consists in effective management of concomitant risk factors such as hypertension, dyslipidemia, and adiposity resulting from faulty nutrition and lack of exercise. In the large majority of overweight type 2 diabetics, metformin is the oral antidiabetic agent of first choice provided the patient does not exhibit renal insufficiency, which represents the most important contraindication. This recommendation for monotherapy of overweight type 2 diabetics is supported by an endpoint study. In contrast, no equivalent evidence is available on any of the possible options for oral combination therapy. Topics: Administration, Oral; Diabetes Mellitus, Type 2; Germany; Glucagon; Glucagon-Like Peptide 1; Glucagon-Like Peptides; Humans; Hypoglycemic Agents; Metformin; Obesity; Peptide Fragments; Peptides; Practice Guidelines as Topic; Practice Patterns, Physicians'; Treatment Outcome | 2004 |
Gastric inhibitory polypeptide and glucagon-like peptide-1 in the pathogenesis of type 2 diabetes.
The incretin effect denominates the phenomenon that oral glucose elicits a higher insulin response than does intravenous glucose. The two hormones responsible for the incretin effect, glucose-dependent insulinotropic hormone (GIP) and glucagon-like peptide-1 (GLP-1), are secreted after oral glucose loads and augment insulin secretion in response to hyperglycemia. In patients with type 2 diabetes, the incretin effect is reduced, and there is a moderate degree of GLP-1 hyposecretion. However, the insulinotropic response to GLP-1 is well maintained in type 2 diabetes. GIP is secreted normally or hypersecreted in type 2 diabetes; however, the responsiveness of the endocrine pancreas to GIP is greatly reduced. In approximately 50% of first-degree relatives of patients with type 2 diabetes, similarly reduced insulinotropic responses toward exogenous GIP can be observed, without significantly changed secretion of GIP or GLP-1 after oral glucose. This opens the possibility that a reduced responsiveness to GIP is an early step in the pathogenesis of type 2 diabetes. On the other hand, this provides a basis to use incretin hormones, especially GLP-1 and its derivatives, to replace a deficiency in incretin-mediated insulin secretion in the treatment of type 2 diabetes. Topics: Animals; Blood Glucose; Diabetes Mellitus, Type 2; Gastric Inhibitory Polypeptide; Glucagon; Glucagon-Like Peptide 1; Humans; Insulin; Insulin Secretion; Peptide Fragments; Protein Precursors | 2004 |
The incretin approach for diabetes treatment: modulation of islet hormone release by GLP-1 agonism.
Glucagon-like peptide (GLP)-1 is a gut hormone that stimulates insulin secretion, gene expression, and beta-cell growth. Together with the related hormone glucose-dependent insulinotropic polypeptide (GIP), it is responsible for the incretin effect, the augmentation of insulin secretion after oral as opposed to intravenous administration of glucose. Type 2 diabetic patients typically have little or no incretin-mediated augmentation of insulin secretion. This is due to decreased secretion of GLP-1 and loss of the insulinotropic effects of GIP. GLP-1, however, retains insulinotropic effects, and the hormone effectively improves metabolism in patients with type 2 diabetes. Continuous subcutaneous administration greatly improved glucose profiles and lowered body weight and HbA1c levels. Further, free fatty acid levels were lowered, insulin resistance was improved, and beta-cell performance was greatly improved. The natural peptide is rapidly degraded by the enzyme dipeptidyl peptidase IV (DPP IV), but resistant analogs as well as inhibitors of DPP IV are now under development, and both approaches have shown remarkable efficacy in experimental and clinical studies. Topics: Animals; Diabetes Mellitus, Type 2; Disease Models, Animal; Gastrointestinal Hormones; Glucagon; Glucagon-Like Peptide 1; Humans; Islets of Langerhans; Peptide Fragments; Protein Precursors | 2004 |
Glucagon-like peptide-1: regulation of insulin secretion and therapeutic potential.
Glucagon-like peptide-1 (GLP-1) is an intestinally derived insulinotropic hormone currently under investigation for use as a novel therapeutic agent in the treatment of type 2 diabetes. One of several important effects of GLP-1 is on nutrient-induced pancreatic hormone release and is mediated by binding to a specific G-protein coupled receptor resulting in the activation of adenylate cyclase and an increase in cAMP generation. In the beta-cell, cAMP binds and modulates activities of both protein kinase A and cAMP-regulated guanine nucleotide exchange factor II, thereby enhancing glucose-dependent insulin secretion. The stimulatory action of GLP-1 on insulin secretion involves interaction with a plethora of signal transduction processes including ion channel activity, intracellular Ca(2+) handling and exocytosis of the insulin-containing granules. In this review we focus principally on recent advances in our understanding on the cellular mechanisms proposed to underlie GLP-1's insulinotropic effect and attempt to incorporate this knowledge into a working model for the control of insulin secretion. Lastly, this review discusses the applicability of GLP-1 as a therapeutic agent for the treatment of type 2 diabetes. Topics: Adenosine Triphosphate; Animals; Calcium; Diabetes Mellitus, Type 2; Dipeptidyl Peptidase 4; Glucagon; Glucagon-Like Peptide 1; Glucagon-Like Peptide-1 Receptor; Glucose; Humans; Insulin; Insulin Secretion; Ion Channels; Islets of Langerhans; Peptide Fragments; Protein Precursors; Receptors, Glucagon | 2004 |
Structurally modified analogues of glucagon-like peptide-1 (GLP-1) and glucose-dependent insulinotropic polypeptide (GIP) as future antidiabetic agents.
Glucagon-like peptide-1(7-36)amide (GLP-1) and glucose-dependent insulinotropic polypeptide (GIP) are gastrointestinal insulin-releasing hormones involved in the regulation of postprandial nutrient homeostasis. These two incretin hormones are glucose-dependent stimulators of pancreatic beta-cell function, exhibiting a spectrum of secondary extrapancreatic activities, which favour the efficient control of blood glucose homeostasis. Such actions of GLP-1 and GIP have generated considerable interest in their possible exploitation as novel agents for the treatment of type 2 diabetes. Despite the many attributes of GLP-1 and GIP as possible future antidiabetic agents, their rapid degradation in the circulation by dipeptidyl peptidase IV (DPP IV) to inactive truncated forms GLP-1(9-36)amide and GIP(3-42), severely limits their therapeutic usefulness. This review will consider recent developments in the design and effectiveness of synthetic DPP IV-resistant analogues of GLP-1 and GIP. Consideration will be given to the effects of N-terminal modification and amino acid substitution of GLP-1 and GIP either side of the DPP IV cleavage site on (i) susceptibility to enzymatic degradation, (ii) binding to native hormone receptor, (iii) ability to elevate intracellular cyclic AMP, (iv) potency as insulin secretagogues, and (v) antihyperglycaemic activity in type 2 diabetes. It will be shown that structural modification can produce a varied set of biological activities, ranging from more efficacious analogues to those which antagonise the activity of the native hormone. The antidiabetic properties of the best GLP-1 and GIP analogues indeed promise to provide the basis for novel, effective and long-acting drugs for type 2 diabetes therapy. This approach is currently being pursued actively by the pharmaceutical industry. Topics: Animals; Delayed-Action Preparations; Diabetes Mellitus, Type 2; Gastric Inhibitory Polypeptide; Glucagon; Glucagon-Like Peptide 1; Humans; Hypoglycemic Agents; Peptide Fragments; Protein Precursors; Structure-Activity Relationship | 2004 |
Aging and insulin secretion.
Glucose tolerance progressively declines with age, and there is a high prevalence of type 2 diabetes and postchallenge hyperglycemia in the older population. Age-related glucose intolerance in humans is often accompanied by insulin resistance, but circulating insulin levels are similar to those of younger people. Under some conditions of hyperglycemic challenge, insulin levels are lower in older people, suggesting beta-cell dysfunction. When insulin sensitivity is controlled for, insulin secretory defects have been consistently demonstrated in aging humans. In addition, beta-cell sensitivity to incretin hormones may be decreased with advancing age. Impaired beta-cell compensation to age-related insulin resistance may predispose older people to develop postchallenge hyperglycemia and type 2 diabetes. An improved understanding of the metabolic alterations associated with aging is essential for the development of preventive and therapeutic interventions in this population at high risk for glucose intolerance. Topics: Adult; Aged; Aged, 80 and over; Aging; Diabetes Mellitus, Type 2; Glucagon; Glucagon-Like Peptide 1; Glucagon-Like Peptides; Glucose Intolerance; Humans; Insulin; Insulin Resistance; Insulin Secretion; Islets of Langerhans; Middle Aged; Nutrition Surveys; Peptide Fragments | 2003 |
Insulin sensitisation in the treatment of Type 2 diabetes.
Type 2 diabetes is reaching epidemic proportions worldwide, fueled by the increasing prevalence of obesity as many populations adopt a western lifestyle. Secondary complications affecting both the microvascular and macrovascular systems are responsible for premature mortality in Type 2 diabetes, with two thirds or more dying of cardiovascular disease. Two interacting metabolic defects, insulin resistance and beta-cell dysfunction are present in Type 2 diabetes. It is now recognised that insulin resistance is central to a cluster of metabolic abnormalities--called the insulin resistance syndrome--that are responsible for the excess of cardiovascular disease. Older antidiabetic agents such as the sulfonylureas, metformin and insulin are more effective than lifestyle modification in reducing microvascular complications of Type 2 diabetes, but overall do not reduce cardiovascular risk. Metformin, although no more effective as a glucose-lowering agent than sulfonylureas or insulin, does significantly reduce cardiovascular disease, probably as a result of its weak insulin-sensitising action. The newly-marketed thiazolidinedione insulin-sensitising antidiabetic agents also improve multiple biomarkers of cardiovascular risk, suggesting that novel approaches to insulin sensitisation will not only provide effective long-term glycaemic control but improve cardiovascular outcomes in Type 2 diabetes. Multiple therapeutic targets within the insulin signalling cascade are being explored, together with follow-up compounds to the first generation thiazolidinediones. These initiatives, together with developments in beta(3)-adrenoceptor agonists, 11 beta-hydroxysteroid dehydrogenase Type 1 inhibitors and modulators of the glucagon-like peptide 1 axis, all of which also potentially enhance insulin sensitivity, are critically evaluated. Topics: 11-beta-Hydroxysteroid Dehydrogenase Type 1; Adrenergic beta-3 Receptor Agonists; Cardiovascular Diseases; Diabetes Mellitus, Type 2; Glucagon; Glucagon-Like Peptide 1; Humans; Hydroxysteroid Dehydrogenases; Hypoglycemic Agents; Insulin; Insulin Resistance; Islets of Langerhans; Metformin; Peptide Fragments; Protein Precursors; Randomized Controlled Trials as Topic; Receptors, Cytoplasmic and Nuclear; Signal Transduction; Thiazoles; Transcription Factors | 2003 |
Glucagon-like peptide 1 and gastric inhibitory polypeptide: potential applications in type 2 diabetes mellitus.
Although the insulinotropic actions of gastric inhibitory polypeptide (GIP) and glucagon-like peptide 1 (GLP-1) have been known for almost 2 decades, the incretin hormones have not yet become available for clinical application. This can be explained by their unfavourable pharmacological properties. Both hormones are rapidly inactivated by the enzyme dipeptidyl peptidase IV (DPP IV), yielding biologically inactive fragments. There have been several attempts to make use of the antidiabetogenic potential of the incretin hormones. Various analogues of GLP-1 and GIP have been generated in order to achieve resistance to DPP IV degradation. The natural GLP-1 receptor agonist exendin-4, found in the saliva of the Gila monster, has a longer biological half-life after subcutaneous injection than GLP-1, and inhibition of DPP IV using, for example, pyrrolidine derivatives provides elevated concentrations of intact, biologically active GIP and GLP-1 endogenously released from the gut. A continuous intravenous infusion of native GLP-1 for a limited time may be suitable in certain clinical situations. Numerous clinical studies are currently underway to evaluate these approaches. Therefore, an antidiabetic treatment based on incretin hormones may become available within the next 5 years. Topics: Diabetes Mellitus, Type 2; Dipeptidyl Peptidase 4; Exenatide; Gastric Inhibitory Polypeptide; Gastrointestinal Hormones; Glucagon; Glucagon-Like Peptide 1; Glucagon-Like Peptides; Humans; Hypoglycemic Agents; Peptide Fragments; Peptides; Protease Inhibitors; Protein Precursors; Venoms | 2003 |
Implementation of GLP-1 based therapy of type 2 diabetes mellitus using DPP-IV inhibitors.
GLP-1 is a peptide hormone from the intestinal mucosa. It is secreted in response to meal ingestion and normally functions in the so-called ileal brake i. e. inhibition of upper gastrointestinal motility and secretion when nutrients are present in the distal small intestine. It also induces satiety and promotes tissue deposition of ingested glucose by stimulating insulin secretion. Thus, it is an essential incretin hormone. In addition, the hormone has been demonstrated to promote insulin biosynthesis and insulin gene expression and to have trophic effects on the beta cells. The trophic effects include proliferation of existing beta cells, maturation of new cells from duct progenitor cells and inhibition of apoptosis. Furthermore glucagon secretion is inhibited. Because of these effects, the hormone effectively improves metabolism in patients with type 2 diabetes mellitus. However, continuous administration of the peptide is necessary because of an exceptionally rapid rate of degradation catalyzed the enzyme dipeptidyl peptidase IV. With inhibitors of this enzyme, it is possible to protect the endogenous hormone and thereby elevate both fasting and postprandial levels of the active hormone. This leads to enhanced insulin secretion and glucose turnover. But will DPP-IV inhibition enhance all effects of the endogenous peptide? The mode of action of GLP-1 is complex involving also interactions with sensory neurons and the central nervous system, where a DPP-IV mediated degradation does not seem to occur. Therefore, it is as yet uncertain wether DDP-IV inhibitors will affect gastrointestinal motility, appetite and food intake. Even the effects of GLP-1 effects on the pancreatic islets may be partly neurally mediated and therefore uninfluenced by DPP-IV inhibition. Topics: Appetite; Diabetes Mellitus, Type 2; Dipeptidyl Peptidase 4; Glucagon; Glucagon-Like Peptide 1; Humans; Insulin; Insulin Secretion; Peptide Fragments; Protease Inhibitors; Protein Precursors | 2003 |
NN-2211 Novo Nordisk.
Novo Nordisk A/S, under license from Scios Inc, is developing NN-2211, a stable analog of the naturally occurring peptide hormone glucagon-like peptide 1 (GLP-1), which stimulates insulin release in response to increases in blood sugar levels, for the potential treatment of type 2 diabetes. Topics: Animals; Clinical Trials as Topic; Diabetes Mellitus, Type 2; Glucagon; Glucagon-Like Peptide 1; Humans; Liraglutide; Technology, Pharmaceutical | 2003 |
Enteroinsular signaling: perspectives on the role of the gastrointestinal hormones glucagon-like peptide 1 and glucose-dependent insulinotropic polypeptide in normal and abnormal glucose metabolism.
The gastrointestinal hormones glucagon-like peptide 1 and glucose-dependent insulinotropic polypeptide are emerging as essential regulators of insulin secretion and glucose homeostasis. These peptides, termed incretins, are the key intermediaries in a system that links the absorption of nutrients in the gut with important metabolic processes in substrate assimilation. New findings indicate that the enteroinsular system mediated by the incretins is relevant to both the pathophysiology and treatment of diabetes.. Important advances have been made in the understanding of mechanisms fundamental to incretin function such as their release from the intestine during meals, their actions on beta-cell secretion, and extrapancreatic effects. In addition, the regulation of islet growth by glucagon-like peptide 1 and glucose-dependent insulinotropic polypeptide is a novel area with considerable support from recent studies. Abnormalities of incretin function are present in patients with diabetes and current research has implicated specific defects of both glucagon-like peptide 1 and glucose-dependent insulinotropic polypeptide action in diabetes. Finally, several pharmacological applications of the incretin signaling pathways are under active investigation for the treatment of diabetes.. With the intensified research of the last several years the physiologic importance of the incretins has been clarified. Enteroinsular signaling is an essential component of the metabolic processes that govern carbohydrate, and likely other nutrient metabolism. As a pathophysiology of the incretins emerges, glucagon-like peptide 1 and glucose-dependent insulinotropic polypeptide will have increasing clinical relevance. This is currently exemplified by the development of therapeutics for diabetes that work through the incretin signaling pathways. Topics: Diabetes Mellitus, Type 2; Gastric Inhibitory Polypeptide; Glucagon; Glucagon-Like Peptide 1; Glucose; Humans; Insulin; Insulin Secretion; Islets of Langerhans; Peptide Fragments; Protein Precursors; Secretory Rate; Signal Transduction | 2003 |
The glucagon-like peptides: a double-edged therapeutic sword?
Topics: Amino Acid Sequence; Animals; Brain; Diabetes Mellitus, Type 2; Exenatide; Glucagon; Glucagon-Like Peptide 1; Glucagon-Like Peptide-1 Receptor; Humans; Insulin; Insulin Secretion; Molecular Sequence Data; Peptide Fragments; Peptides; Protein Precursors; Receptors, Glucagon; Venoms | 2003 |
Gut peptides and type 2 diabetes mellitus treatment.
The gut expresses peptide hormones in endocrine cells and neuropeptides in autonomic nerves. Several of these peptides have the ability to stimulate insulin secretion. Gut hormones that are released after meal ingestion and stimulate insulin secretion postprandially are called incretins. In humans, glucose-dependent insulinotropic polypeptide (GIP) and glucagon-like peptide-1 (GLP-1) are the most important incretins. The potential use of these insulinotropic gut peptides for the treatment of diabetes has been considered. This has been most successful for GLP-1, which exerts antidiabetogenic properties in subjects with type 2 diabetes by stimulating insulin secretion, increasing beta-cell mass, inhibiting glucagon secretion, delaying gastric emptying, and inducing satiety. However, GLP-1 is rapidly degraded by the enzyme dipeptidyl peptidase IV (DPPIV), making it unattractive as a therapeutic agent because of a very short half-life. Successful strategies to overcome this difficulty are the use of DPPIV-resistant GLP-1 receptor agonists, such as NN2211 or exendin-4, and the use of inhibitors of DPPIV, such as NVPDPP728 and P32/98. These two approaches are explored in clinical investigations. Topics: Diabetes Mellitus, Type 2; Gastric Emptying; Gastric Inhibitory Polypeptide; Gastrointestinal Hormones; Glucagon; Glucagon-Like Peptide 1; Humans; Islets of Langerhans; Peptide Fragments; Protein Precursors; Satiation | 2003 |
Enhancing incretin action for the treatment of type 2 diabetes.
To examine the mechanisms of action, therapeutic potential, and challenges inherent in the use of incretin peptides and dipeptidyl peptidase-IV (DPP-IV) inhibitors for the treatment of type 2 diabetes.. The scientific literature describing the biological importance of incretin peptides and DPP-IV inhibitors in the control of glucose homeostasis has been reviewed, with an emphasis on mechanisms of action, experimental diabetes, human physiological experiments, and short-term clinical studies in normal and diabetic human subjects.. Glucagon-like peptide 1 (GLP-1) and glucose-dependent insulinotropic peptide (GIP) exert important effects on beta-cells to stimulate glucose-dependent insulin secretion. Both peptides also regulate beta-cell proliferation and cytoprotection. GLP-1, but not GIP, inhibits gastric emptying, glucagon secretion, and food intake. The glucose-lowering actions of GLP-1, but not GIP, are preserved in subjects with type 2 diabetes. However, native GLP-1 is rapidly degraded by DPP-IV after parenteral administration; hence, degradation-resistant, long-acting GLP-1 receptor (GLP-1R) agonists are preferable agents for the chronic treatment of human diabetes. Alternatively, inhibition of DPP-IV-mediated incretin degradation represents a complementary therapeutic approach, as orally available DPP-IV inhibitors have been shown to lower glucose in experimental diabetic models and human subjects with type 2 diabetes.. GLP-1R agonists and DPP-IV inhibitors have shown promising results in clinical trials for the treatment of type 2 diabetes. The need for daily injections of potentially immunogenic GLP-1-derived peptides and the potential for unanticipated side effects with chronic use of DPP-IV inhibitors will require ongoing scrutiny of the risk-benefit ratio for these new therapies as they are evaluated in the clinic. Topics: Diabetes Mellitus, Type 2; Dipeptidyl Peptidase 4; Enzyme Inhibitors; Gastric Inhibitory Polypeptide; Glucagon; Glucagon-Like Peptide 1; Humans; Peptide Fragments; Protein Precursors | 2003 |
Glucagon-like peptide-1 synthetic analogs: new therapeutic agents for use in the treatment of diabetes mellitus.
Glucagon-like peptide-1-(7-36)-amide (GLP-1) is a potent blood glucose-lowering hormone now under investigation for use as a therapeutic agent in the treatment of type 2 (adult onset) diabetes mellitus. GLP-1 binds with high affinity to G protein-coupled receptors (GPCRs) located on pancreatic beta-cells, and it exerts insulinotropic actions that include the stimulation of insulin gene transcription, insulin biosynthesis, and insulin secretion. The beneficial therapeutic action of GLP-1 also includes its ability to act as a growth factor, stimulating formation of new pancreatic islets (neogenesis) while slowing beta-cell death (apoptosis). GLP-1 belongs to a large family of structurally-related hormones and neuropeptides that include glucagon, secretin, GIP, PACAP, and VIP. Biosynthesis of GLP-1 occurs in the enteroendocrine L-cells of the distal intestine, and the release of GLP-1 into the systemic circulation accompanies ingestion of a meal. Although GLP-1 is inactivated rapidly by dipeptidyl peptidase IV (DDP-IV), synthetic analogs of GLP-1 exist, and efforts have been directed at engineering these peptides so that they are resistant to enzymatic hydrolysis. Additional modifications of GLP-1 incorporate fatty acylation and drug affinity complex (DAC) technology to improve serum albumin binding, thereby slowing renal clearance of the peptides. NN2211, LY315902, LY307161, and CJC-1131 are GLP-1 synthetic analogs that reproduce many of the biological actions of GLP-1, but with a prolonged duration of action. AC2993 (Exendin-4) is a naturally occurring peptide isolated from the lizard Heloderma, and it acts as a high affinity agonist at the GLP-1 receptor. This review summarizes structural features and signal transduction properties of GLP-1 and its cognate beta-cell GPCR. The usefulness of synthetic GLP-1 analogs as blood glucose-lowering agents is discussed, and the applicability of GLP-1 as a therapeutic agent for treatment of type 2 diabetes is highlighted. Topics: Animals; Blood Glucose; Diabetes Mellitus, Type 2; Exenatide; Glucagon; Glucagon-Like Peptide 1; Glucagon-Like Peptide-1 Receptor; Humans; Insulin; Insulin Secretion; Peptide Fragments; Peptides; Protein Precursors; Receptors, Glucagon; Venoms | 2003 |
Incretins and their analogues as new antidiabetic drugs.
Glucagon-like peptide 1 (GLP-1) is a gut (incretin) hormone with multiple actions that could potentially contribute to an antidiabetic effect. This includes: (a) glucose-dependent insulinotropic actions; (b) glucagonostatic actions; (c) a reduction in appetite/promotion of satiety leading to reduced food intake and weight reduction; (d) the deceleration of gastric emptying; and (e) the stimulation of islet growth, differentiation and regeneration. Thus, multiple aspects of the type 2 diabetic phenotype can potentially be improved or even corrected by GLP-1. The native gut hormone, however, after intravenous injection or absorption from subcutaneous depots, is proteolytically degraded and eliminated from the circulation too quickly to be useful for the treatment of diabetes. GLP-1 derivatives (receptor agonists) with prolonged pharmacokinetics that promise a potential for clinical use in the near future are being developed. Topics: Animals; Diabetes Mellitus, Type 2; Drug Therapy; Glucagon; Glucagon-Like Peptide 1; Humans; Hypoglycemic Agents; Peptide Fragments; Protein Precursors | 2003 |
Weight effect of current and experimental drugs for diabetes mellitus: from promotion to alleviation of obesity.
Two landmark intervention studies, the Diabetes Control and Complications Trial (DCCT) in patients with type 1 diabetes mellitus and the United Kingdom Prospective Diabetes Study (UKPDS) in patients with type 2 diabetes mellitus, have unequivocally demonstrated that intensive diabetes therapy reduces the risk of long-term diabetic complications. As a result, the commonly accepted treatment goal for most patients with diabetes is the achievement and maintenance of glycemic control that is as close to the normal range as safely possible. Important adverse effects of intensive diabetes therapy, particularly when the treatment includes insulin or several of the oral antihyperglycemic agents, are an increased risk of hypoglycemia and undesired weight gain. Improvement of glycemic control with insulin, insulin secretagogues (sulfonylureas, meglitinides), and insulin sensitizers (thiazolidinediones) is often accompanied by weight gain. The etiology of this weight gain is likely multifaceted, including a reduction of glucosuria, increased caloric intake to prevent hypoglycemia, and anabolic effects on adipose tissue. Biguanides and alpha-glucosidase inhibitors have a neutral or even positive effect (decrease) on weight, which may partly be attributable to their non-insulinotropic mechanism of action, a modest effect on satiety, and to their gastrointestinal adverse effect profile. Several antihyperglycemic agents that are currently in clinical development may improve glycemic control in conjunction with weight reduction. These include an analog of the pancreatic beta-cell hormone amylin (pramlintide), as well as glucagon-like peptide-1 (GLP-1) and exendin, and their analogs. Pharmacological agents with antihyperglycemic and positive weight effects have the potential to become important additions to our therapeutic armamentarium, in that they may help to achieve glycemic targets while addressing the long-standing clinical problem of weight gain as an adverse effect of intensive diabetes therapy. Topics: Amyloid; Benzamides; Biguanides; Body Weight; Diabetes Mellitus; Diabetes Mellitus, Type 1; Diabetes Mellitus, Type 2; Glucagon; Glucagon-Like Peptide 1; Glycoside Hydrolase Inhibitors; Humans; Hypoglycemic Agents; Insulin; Islet Amyloid Polypeptide; Obesity; Peptide Fragments; Protein Precursors; Sulfonylurea Compounds; Thiazolidinediones; Weight Gain | 2003 |
Gastric inhibitory polypeptide: the neglected incretin revisited.
After the ingestion of fat- and glucose-rich meals, gut hormones are secreted into the circulation in order to stimulate insulin secretion. This so-called "incretin effect" is primarily conferred by Glucagon-like peptide 1 (GLP-1) and Gastric Inhibitory Polypeptide (GIP). In contrast to GLP-1, GIP has lost most of its insulinotropic effect in type 2 diabetic patients. In addition to its main physiological role in the regulation of endocrine pancreatic secretion, GIP exerts various peripheral effects on adipose tissue and lipid metabolism, thereby leading to increased lipid deposition in the postprandial state. In some animal models, an influence on gastrointestinal functions has been described. However, such effects do not seem to play an important role in humans. During the last years, the major line of research has focussed on GLP-1, due to its promising potential for the treatment of type 2 diabetes mellitus. However, the physiological importance of GIP in the regulation of insulin secretion has been shown to even exceed that of GLP-1. Furthermore, work from various groups has provided evidence that GIP contributes to the pathogenesis of type 2 diabetes to a considerable degree. Recent data with modified GIP analogues further suggested a possibility of therapeutic use in the treatment of type 2 diabetes. Thus, it seems worthwhile to refocus on this important and-sometimes-neglected incretin hormone. The present work aims to review the physiological functions of GIP, to characterize its role in the pathogenesis of type 2 diabetes, and to discuss possible clinical applications and future perspectives in the light of new findings. Topics: Adipose Tissue; Amino Acid Sequence; Animals; Blood Glucose; C-Peptide; Diabetes Mellitus, Type 2; Gastric Inhibitory Polypeptide; Glucagon; Glucagon-Like Peptide 1; Glucose; Humans; Insulin; Lipids; Models, Biological; Molecular Sequence Data; Pancreatic Hormones; Peptide Fragments; Postprandial Period; Protein Precursors; Secretin; Sequence Homology, Amino Acid; Stomach | 2002 |
[Glucagon-like peptide-1 (GLP-1) receptor].
Topics: Animals; Diabetes Mellitus, Type 2; Exenatide; Glucagon; Glucagon-Like Peptide 1; Glucagon-Like Peptide-1 Receptor; Glucagon-Like Peptides; Humans; Insulin; Insulin Secretion; Peptide Fragments; Peptides; Polymorphism, Genetic; Protein Precursors; Receptors, Glucagon; Venoms | 2002 |
Preclinical developments in type 2 diabetes.
Type 2 diabetes is associated with insulin resistance in peripheral tissues, such as muscle and fat, impaired glucose-stimulated insulin secretion from pancreatic beta-cells and elevated hepatic gluconeogenesis. Current pharmacotherapy does not adequately address the metabolic defects underlying this disease. Thus, novel targets are being explored that enhance insulin action at target tissues, stimulate carbohydrate and fat catabolism, decrease endogenous glucose production and increase pancreatic beta-cell neogenesis and glucose-dependent insulin secretion. This article reviews recent developments in research on several of these targets, namely acetyl-CoA carboxylase 2 (ACC2), I kappa kinase (IKK) beta, dipeptidyl peptidase IV (DPP-IV) and glucagon-like peptide-1 receptor (GLP-1R). Topics: Acetyl-CoA Carboxylase; Animals; Blood Glucose; Diabetes Mellitus, Type 2; Dipeptidyl Peptidase 4; Fatty Acids, Nonesterified; Glucagon; Glucagon-Like Peptide 1; I-kappa B Kinase; Insulin Resistance; Peptide Fragments; Protein Precursors; Protein Serine-Threonine Kinases | 2002 |
Novel peptides under development for the treatment of type 1 and type 2 diabetes mellitus.
Recent availability of expanded treatment options for both type 1 and type 2 diabetes has not translated into easier and significantly better glycemic and metabolic management. Patients with type 1 diabetes continue to experience increased risk of hypoglycemic episodes and progressive weight gain resulting from intensive insulin treatment, despite the recent availability of a variety of insulin analog. Given the progressive nature of the disease, most patients with type 2 diabetes inevitably proceed from oral agent monotherapy to combination therapy and, ultimately, require exogenous insulin replacement. Insulin therapy in type 2 diabetes is also accompanied by untoward weight gain. Both type 1 and type 2 diabetes continue to be characterized by marked postprandial hyperglycemia. Two hormones still in development are candidates for pharmacologic intervention, have novel modes of action (some centrally mediated), and show great promise in addressing some of the unmet needs of current diabetes management. Pramlintide acetate, an analog of the beta cell hormone amylin and the first non-insulin related therapeutic modality for type 1 and type 2 diabetic patients with severe beta cell failure, may be useful as adjunctive therapy to insulin. The principal anti-diabetic effects of pramlintide arise from interactions via its cognate receptors located in the central nervous system resulting in postprandial glucagon suppression, modulation of nutrient absorption rate, and reduction of food intake. Another polypeptide hormone, exendin-4, exerts at least some of its pharmacologic actions as an agonist at the glucagon-like peptide-1 (GLP-1) receptor. GLP-1 and related compounds exhibit multiple modes of action, the most notable being a glucose-dependent insulinotropic effects and the potential to preserve or improve the beta-cell function. The latter effect could potentially halt or delay the progressive deterioration of the diabetic state associated with type 2 diabetes. Physiologically, both amylin and glucagon-like peptide (GLP)-1, along with insulin, are involved in a coordinated and concerted interplay between hormones acting both centrally and peripherally to provide meticulous control over the rate of appearance of exogenous and endogenous glucose and to match that rate to the rate of glucose disappearance. Both hormones are deficient in diabetes. Therapies directed at restoring this complex physiology have the potential to facilitate glucose control and thus m Topics: Amyloid; Diabetes Mellitus, Type 1; Diabetes Mellitus, Type 2; Drug Design; Exenatide; Glucagon; Glucagon-Like Peptide 1; Humans; Hypoglycemic Agents; Islet Amyloid Polypeptide; Peptide Fragments; Peptides; Postprandial Period; Protein Precursors; Venoms | 2002 |
Pancreatic and extrapancreatic effects of GLP-1.
Glucagon-like peptide-1 (GLP-1), an incretin hormone which helps to regulate plasma glucose levels, is considered a potential agent for the treatment of type-2 diabetes mellitus, because of its insulinotropic capacity and insulinomimetic actions. In normal conditions, the beta-cell secretory response to GLP-1 is modulated by the extracellular concentration of D-glucose; however, the recognition of D-glucose by the beta-cell is often impaired in type-2 diabetes, and this could impede the full GLP-1 insulinotropic action. Non-glucidic substrates, such as the dimethyl ester of succinic acid, restore the effect of GLP-1 in the isolated perfused rat pancreas of normal or diabetic rats, in the absence of any other exogenous nutrient; likewise, the dimethyl ester of succinic or L-glutamic acid, and the monomethyl ester of pyruvic acid, potentiate the in vivo beta-cell secretory response to GLP-1 in normal and diabetic rats. Therefore, it was proposed that nutrients susceptible to bypass the site-specific defects of the diabetic beta-cell, could be used to potentiate and/or prolong the insulinotropic action of antidiabetic agents such as GLP-1. In vitro, GLP-1 insulin-like effects on glucose metabolism have been documented in normal and diabetic rat liver, and in rat and human skeletal muscle. In rat and human adipocytes, GLP-1 is lipolytic and/or lipogenic, and also stimulates parameters involved in the glucose metabolism. In liver, muscle and fat, GLP-1 seems to act through specific receptors, apparently different--at least in liver and muscle--in structure or signaling pathway from the pancreatic one. It is proposed that an inositolphosphoglycan might be a second messenger of GLP-1 action in extrapancreatic tissues. Topics: Animals; Diabetes Mellitus, Type 2; Glucagon; Glucagon-Like Peptide 1; Humans; Insulin; Insulin Secretion; Pancreas; Peptide Fragments; Protein Precursors | 2002 |
Harnessing the therapeutic potential of glucagon-like peptide-1: a critical review.
Glucagon-like peptide-1 (GLP-1) is synthesized from proglucagon in enteroendocrine cells and regulates glucose homeostasis via multiple complementary actions on appetite, gastrointestinal motility and islet hormone secretion. GLP-1 is secreted from the distal gut in response to food ingestion, and levels of circulating GLP-1 may be diminished in patients with type 2 diabetes mellitus. GLP-1 administration stimulates glucose-dependent insulin secretion, inhibits glucagon secretion, and lowers blood glucose in normal and diabetic rodents and in humans. GLP-1 exerts additional glucose-lowering actions in patients with diabetes mellitus already treated with metformin or sulfonylurea therapy. GLP-1 inhibits gastric emptying in healthy individuals and those with diabetes mellitus, and excess GLP-1 administration may cause nausea or vomiting in susceptible individuals. Chronic GLP-1 treatment of normal or diabetic rodents is associated with bodyweight loss and GLP-1 agonists transiently inhibit food intake and may prevent bodyweight gain in humans. The potential for GLP-1 therapy to prevent deterioration of beta-cell function is exemplified by studies demonstrating that GLP-1 analogs stimulate proliferation and neogenesis of beta-cells, leading to expansion of beta-cell mass in diabetic rodents. The rapid N-terminal inactivation of bioactive GLP-1 by dipeptidyl peptidase-IV (DPP-IV) limits the utility of the native peptide for the treatment of patients with diabetes mellitus, and has fostered the development of more potent and stable protease-resistant GLP-1 analogs which exhibit longer durations of action. The importance of DPP-IV for glucose control is illustrated by the phenotype of rodents with genetic inactivation of DPP-IV which exhibit reduced glycemic excursion and increased levels of circulating GLP-1 in vivo. Inhibitors of DPP-IV potentiate incretin action by preventing degradation of GLP-1 and glucose-dependent insulinotropic peptide, and lower blood glucose in normal rodents and in experimental models of diabetes mellitus. Hence, orally available DPP-IV inhibitors also represent a new class of therapeutic agents that enhance incretin action for the treatment of patients with type 2 diabetes mellitus. Topics: Diabetes Mellitus, Type 2; Glucagon; Glucagon-Like Peptide 1; Humans; Peptide Fragments; Protein Precursors | 2002 |
Biological actions and therapeutic potential of the glucagon-like peptides.
The glucagon-like peptides (GLP-1 and GLP-2) are proglucagon-derived peptides cosecreted from gut endocrine cells in response to nutrient ingestion. GLP-1 acts as an incretin to lower blood glucose via stimulation of insulin secretion from islet beta cells. GLP-1 also exerts actions independent of insulin secretion, including inhibition of gastric emptying and acid secretion, reduction in food ingestion and glucagon secretion, and stimulation of beta-cell proliferation. Administration of GLP-1 lowers blood glucose and reduces food intake in human subjects with type 2 diabetes. GLP-2 promotes nutrient absorption via expansion of the mucosal epithelium by stimulation of crypt cell proliferation and inhibition of apoptosis in the small intestine. GLP-2 also reduces epithelial permeability, and decreases meal-stimulated gastric acid secretion and gastrointestinal motility. Administration of GLP-2 in the setting of experimental intestinal injury is associated with reduced epithelial damage, decreased bacterial infection, and decreased mortality or gut injury in rodents with chemically induced enteritis, vascular-ischemia reperfusion injury, and dextran sulfate-induced colitis. GLP-2 also attenuates chemotherapy-induced mucositis via inhibition of drug-induced apoptosis in the small and large bowel. GLP-2 improves intestinal adaptation and nutrient absorption in rats after major small bowel resection, and in humans with short bowel syndrome. The actions of GLP-2 are mediated by a distinct GLP-2 receptor expressed on subsets of enteric nerves and enteroendocrine cells in the stomach and small and large intestine. The beneficial actions of GLP-1 and GLP-2 in preclinical and clinical studies of diabetes and intestinal disease, respectively, has fostered interest in the potential therapeutic use of these gut peptides. Nevertheless, the actions of the glucagon-like peptides are limited in duration by enzymatic inactivation via cleavage at the N-terminal penultimate alanine by dipeptidyl peptidase IV (DP IV). Hence, inhibitors of DP IV activity, or DP IV-resistant glucagon-like peptide analogues, may be alternative therapeutic approaches for treatment of human diseases. Topics: Animals; Diabetes Mellitus, Type 2; Glucagon-Like Peptide 1; Glucagon-Like Peptide 2; Humans; Intestinal Diseases; Peptides | 2002 |
Glucose tolerance, glucose utilization and insulin secretion in ageing.
Ageing is associated with an increased incidence of hypertension, macrovascular disease and type 2 diabetes (non-insulin-dependent diabetes). It has been suggested that a common mechanism may be responsible for all of these pathological states since all of these conditions often cluster in the same individual. Epidemiological and clinical data have consistently demonstrated an association between insulin resistance and/or hyperinsulinaemia and glucose intolerance, dyslipidaemia and elevated systolic blood pressures. Therefore, insulin resistance and hyperinsulinaemia have been proposed as the causal link among the elements of the clusters. The elderly are more glucose intolerant and insulin resistant, but it remains controversial whether this decrease in function is due to an inevitable consequence of 'biological ageing' or due to environmental or lifestyle variables, noticeably increased adiposity/altered fat distribution and physical inactivity. An increase of these modifiable factors has been shown to result in increases in insulin resistance and hyperinsulinaemia and vice versa. However, insulin secretion appears to decrease with age even after adjustments for differences in adiposity, fat distribution and physical activity. The glucose intolerance of ageing may be due, in part, to decreased insulin sensitivity of pancreatic / cells to insulinotropic gut hormones (GLP1/GIP) and in part to alterations of hepatic glucose production. Topics: Aging; Diabetes Mellitus, Type 2; Glucagon; Glucagon-Like Peptide 1; Glucagon-Like Peptides; Glucose; Glucose Tolerance Test; Humans; Insulin; Islets of Langerhans; Liver; Peptide Fragments | 2002 |
The multifaceted potential of glucagon-like peptide-1 as a therapeutic agent.
Glucagon-like peptide-1 (GLP-1), an intestinal gut hormone, is rapidly emerging as a new therapeutic agent for the treatment of diabetes mellitus. GLP-1, released from intestinal L-cells, is renowned for its potent stimulation of insulin biosynthesis and release from pancreatic b-cells. Exogenous administration of GLP-1 to subjects with type 2 diabetes results in the normalization of plasma glucose concentrations, in part, as a result of augmented glucose-stimulated insulin secretion. However, it is now recognized that GLP-1 has several other anti-diabetic actions that collectively improve the type 2 diabetic phenotype, and may also prove beneficial in the treatment of type 1 diabetes. These effects include the deceleration of gastric emptying and promotion of satiety, thereby reducing the availability of nutrients for absorption and reducing the requirement for insulin secretion. GLP-1 also reduces plasma glucose levels by suppressing glucagon secretion from pancreatic a-cells and potentially by improving insulin sensitivity in peripheral tissues. Further-more, GLP-1 upregulates expression of b-cell genes (GLUT2, glucokinase, insulin, and PDX-1) and promotes b-cell neogenesis and differentiation of ductal cells into insulin secreting cells. Although initial clinical trials indicate GLP-1 has excellent therapeutic potential, its relatively short-lived biological activity and delivery difficulties limit its appeal. Several approaches that are currently being explored to overcome these limitations include mobilizing endogenous GLP-1 release, preserving the biological activity of the native peptide, and developing GLP-1 analogues with extended durations of action. Topics: Animals; Blood Glucose; Clinical Trials as Topic; Diabetes Mellitus, Experimental; Diabetes Mellitus, Type 2; Drug Administration Routes; Gastric Emptying; Gene Expression Regulation; Glucagon; Glucagon-Like Peptide 1; Glucagon-Like Peptide-1 Receptor; Humans; Hypoglycemic Agents; Insulin; Insulin Resistance; Insulin Secretion; Intestine, Small; Islets of Langerhans; Peptide Fragments; Protein Precursors; Rats; Receptors, Glucagon; Satiety Response; Signal Transduction | 2002 |
Dipeptidyl peptidase IV inhibition as an approach to the treatment and prevention of type 2 diabetes: a historical perspective.
Topics: Diabetes Mellitus, Type 2; Dipeptidyl Peptidase 4; Glucagon; Glucagon-Like Peptide 1; History, 20th Century; History, 21st Century; Peptide Fragments; Protease Inhibitors; Protein Precursors | 2002 |
[A therapeutic option for type-2 diabetes. The incretion hormone GLP-1].
Topics: Animals; Diabetes Mellitus, Type 2; Glucagon; Glucagon-Like Peptide 1; Humans; Hypoglycemic Agents; Insulin; Peptide Fragments; Protein Precursors | 2002 |
Gastric inhibitory polypeptide analogues: do they have a therapeutic role in diabetes mellitus similar to that of glucagon-like Peptide-1?
Gastric inhibitory polypeptide (GIP, also called glucose-dependent insulinotropic polypeptide) and glucagon-like peptide-1 (GLP-1) are peptide hormones from the gut that enhance nutrient-stimulated insulin secretion (the 'incretin' effect). Judging from experiments in mice with targeted deletions of GIP and GLP-1 receptors, the incretin effect is essential for normal glucose tolerance. In patients with type 2 diabetes mellitus it turns out that the incretin effect is severely impaired or abolished. The explanation seems to be that both the secretion of GLP-1 and the effect of GIP are impaired (whereas both the secretion of GIP and the effect of GLP-1 are near normal). The impaired GLP-1 secretion is probably a consequence of diabetic metabolic disturbances. The known genetic variations in the GIP receptor sequence are not associated with type 2 diabetes mellitus, but a defective insulinotropic effect of GIP may be found in first degree relatives of the patients, suggesting a genetic background for the defect. The molecular nature of the defect is not known and given the close similarity of the two receptors and their signalling, the dissociation of their effects is remarkable. Whereas GLP-1 and its analogues are attractive as therapeutic agents for type 2 diabetes mellitus, analogues of GIP are unlikely to be effective. On the other hand, GIP seems to play an important role in lipid metabolism, promoting the disposal of ingested lipids, and mice with a targeted deletion of the GIP receptor do not become obese when exposed to a high-fat diet. Therefore, antagonistic analogues of GIP may be speculated to have a role in the pharmaceutical management of obesity. Topics: Animals; Diabetes Mellitus, Type 2; Gastric Inhibitory Polypeptide; Glucagon; Glucagon-Like Peptide 1; Glucagon-Like Peptides; Humans; Insulin; Insulin Secretion; Peptide Fragments; Protein Precursors | 2002 |
New pharmacological development (alpha glucosidase inhibitors, amylin analogues, GLP-1, thiozolidinediones, short acting insulin analogues).
Topics: Amyloid; Blood Glucose; Diabetes Mellitus, Type 2; Glucagon; Glucagon-Like Peptide 1; Glycated Hemoglobin; Glycoside Hydrolase Inhibitors; Humans; Hypoglycemic Agents; Insulin; Islet Amyloid Polypeptide; Peptide Fragments; Protein Precursors; Rosiglitazone; Thiazoles; Thiazolidinediones | 2001 |
Glucagon-like peptide-1.
There is a progressive impairment in beta-cell function with age. As a result, 19 percent of the U.S. population over the age of 65 is diagnosed with type 2 diabetes mellitus (DM). Glucagon-like peptide-1 (GLP-1) is a potent insulin secretagogue that has multiple synergetic effects on the glucose-dependent insulin secretion pathways of the beta-cell. This peptide and its longer-acting analog exendin-4 are currently under review as treatments for type 2 DM. In our work on the rodent model of glucose intolerance in aging, we found that GLP-1 is capable of rescuing the age-related decline in beta-cell function. We have shown that this is due to the ability of GLP-1 to 1) recruit beta-cells into a secretory mode; 2) upregulate the genes of the beta-cell glucose-sensing machinery; and 3) cause beta-cell differentiation and neogenesis. Our investigations into the mechanisms of action of GLP-1 began by using the reverse hemolytic plaque assay to quantify insulin secretion from individual cells of the RIN 1046-38 insulinoma cell line in response to acute treatment with the peptide. GLP-1 increases both the number of cells secreting insulin and the amount secreted per cell. This response to GLP-1 is retained even in the beta cell of the old (i.e., 22-month), glucose-intolerant Wistar rat, which exhibits a normal, first-phase insulin response to glucose following an acute bolus of GLP-1. Preincubation with GLP-1 (24 hours) potentiates glucose- and GLP-1-dependent insulin secretion and increases insulin content in the insulinoma cells. Treatment of old Wistar rats for 48 hours with GLP-1 leads to normalization of the insulin response and an increase in islet insulin content and mRNA levels of GLUT 2 and glucokinase. PDX-1, a transcriptional factor activator of these three genes, also is upregulated in the insulinoma cell line in aged rats and diabetic mice following treatment with GLP-1. Administration of GLP-1 to old rats leads to pancreatic cell proliferation, insulin-positive clusters, and an increase in beta-cell mass. This evidence led us to believe that GLP-1 is an endocrinotrophic factor. We used an acinar cell line to show that GLP-1 can directly cause the conversion of a putative pro-endocrine cell into an endocrine one. Thus, the actions of GLP-1 on the beta-cell are complex, with possible benefits to the diabetic patient that extend beyond a simple glucose-dependent increase in insulin secretion. The major limitation to GLP-1 as a clinical treatment is it Topics: Age Factors; Aged; Aging; Animals; Cell Line; Diabetes Mellitus, Type 2; Glucagon; Glucagon-Like Peptide 1; Glucokinase; Glucose Transporter Type 2; Homeodomain Proteins; Humans; Insulin; Islets of Langerhans; Models, Biological; Monosaccharide Transport Proteins; Peptide Fragments; Protein Precursors; Rats; Rats, Wistar; RNA, Messenger; Time Factors; Trans-Activators; Up-Regulation | 2001 |
The entero-insular axis in type 2 diabetes--incretins as therapeutic agents.
The search for intestinal factors regulating the endocrine secretion of the pancreas started soon after the discovery of secretin, i.e. nearly 100 years ago. Insulinotropic factors of the gut released by nutrients and stimulating insulin secretion in physiological concentrations in the presence of elevated blood glucose levels have been named incretins. Of the known gut hormones only gastric inhibitory polypeptide (GIP) and glucagon-like polypeptide-1 (GLP-1 [7-36] amide) fulfill this definition.--The incretin effect (i.e. the ratio between the integrated insulin response to an oral glucose load and an isoglycaemic intravenous glucose infusion) is markedly diminished in patients with type 2 diabetes mellitus, while the plasma levels of GIP and GLP-1 and their responses to nutrients are in the normal range. Therefore, a reduced responsiveness of the islet B-cells to incretins has been postulated. This insensitivity of the diabetic B-cells towards incretins can be overcome by supraphysiological (pharmacological) concentrations of GLP-1 [7-36], however not of GIP. Accordingly, fasting and postprandial glucose levels can be normalized in patients with type 2 diabetes by infusions of GLP-1 [7-36]. Further studies revealed that this is partially due to the fact that GLP-1 [7-36]--in addition to its insulinotropic effect--also inhibits glucagon secretion and delays gastric emptying. These three antidiabetic effects qualify GLP-1 [7-36] as an interesting therapeutic tool, mainly for type 2 diabetes. However, because of its short plasma half life time natural GLP-1 [7-36] is not suitable for subcutaneous application. At present methods are being developed to improve the pharmacokinetics of GLP-1 by inhibition of the cleaving enzyme dipeptidyl peptidase IV (DPP-IV) or by synthesis of DPP-IV resistant GLP-1 analogues. Also naturally occurring GLP-1 analogues (for instance exendin-4) with a much longer half life time than GLP-1 [7-36] are being tested.--Thus, after 100 years of speculations and experimentations, incretins and their analogues are emerging as new antidiabetic drugs. Topics: Animals; Diabetes Mellitus, Type 2; Gastric Inhibitory Polypeptide; Glucagon; Glucagon-Like Peptide 1; Glucagon-Like Peptides; Humans; Intestines; Islets of Langerhans; Peptide Fragments; Protein Precursors | 2001 |
Development of glucagon-like peptide-1-based pharmaceuticals as therapeutic agents for the treatment of diabetes.
Glucagon-like peptide-1 (GLP-1) is released from gut endocrine cells following nutrient ingestion and acts to regulate nutrient assimilation via effects on gastrointestinal motility, islet hormone secretion, and islet cell proliferation. Exogenous administration of GLP-1 lowers blood glucose in normal rodents and in multiple experimental models of diabetes mellitus. Similarly, GLP-1 lowers blood glucose in normal subjects and in patients with type 2 diabetes. The therapeutic utility of the native GLP-1 molecule is limited by its rapid enzymatic degradation by the serine protease dipeptidyl peptidase IV. This review highlights recent advances in our understanding of GLP-1 physiology and GLP-1 receptor signaling, and summarizes current pharmaceutical strategies directed at sustained activation of GLP-1 receptor-dependent actions for glucoregulation in vivo. Given the nutrient-dependent control of GLP-1 release, neutraceuticals or modified diets that enhance GLP-1 release from the enteroendocrine cell may exhibit glucose-lowering properties in human subjects. The utility of GLP-1 derivatives engineered for sustained action and/or DP IV-resistance, and the biological activity of naturally occurring GLP-1-related molecules such as exendin-4 is reviewed. Circumventing DP IV-mediated incretin degradation via inhibitors that target the DP IV enzyme represents a complementary strategy for enhancing GLP-1-mediated actions in vivo. Finally, the current status of alternative GLP-1-delivery systems via the buccal and enteral mucosa is briefly summarized. The findings that the potent glucose-lowering properties of GLP-1 are preserved in diabetic subjects, taken together with the potential for GLP-1 therapy to preserve or augment beta cell mass, provides a powerful impetus for development of GLP-1-based human pharmaceuticals. Topics: Animals; Diabetes Mellitus, Type 2; Dipeptidyl Peptidase 4; Drug Delivery Systems; Exenatide; Glucagon; Glucagon-Like Peptide 1; Glucagon-Like Peptide-1 Receptor; Humans; Peptide Fragments; Peptides; Protein Precursors; Receptors, Glucagon; Technology, Pharmaceutical; Venoms | 2001 |
Incretin hormones--an update.
Incretin hormones are insulinotropic hormones from the intestinal mucosa, which after being released in response to ingestion of a meal, enhance insulin secretion in excess of that elicited by the absorbed nutrients (glucose. amino acids etc) themselves. To day it is well established that the most important incretin hormones are glucose-dependent insulinotropic polypeptide (GIP, previously known as gastric inhibitory polypeptide) and glucagon-like peptide-1 (GLP-1) from the upper and lower small intestinal mucosa, respectively. It has been shown that interference with the incretin function causes glucose intolerance and it has also been shown that the incretin function is greatly impaired in type 2 diabetes mellitus. The reason for this seems to be twofold: an impaired secretion of GLP-1 and a severely impaired insulinotropic effect of GIP in these patients. In agreement with this, administration of the active incretin, GLP-1, to patients with type 2 diabetes may nearly normalise their fasting and postprandial hyperglycaemia. In addition to its insulinotropic effects, GLP-1 has been shown to stimulate the formation of new beta cells in rodents, partly by enhanced beta cell proliferation and partly by enhancing differentiation of duct progenitor cells to mature beta cells. GLP-1 also inhibits glucagon secretion, inhibits gastric emptying and reduces appetite and food intake. During the last years, therefore, several most promising attempts have been made to develop GLP-1 into a clinically useful therapeutic agent for the treatment of type 2 diabetes. Topics: Animals; Diabetes Mellitus, Type 2; Gastric Inhibitory Polypeptide; Glucagon; Glucagon-Like Peptide 1; Glucagon-Like Peptides; Glucose; Humans; Insulin; Insulin Secretion; Intestinal Mucosa; Peptide Fragments; Protein Precursors | 2001 |
New approaches in the treatment of type 2 diabetes.
Type 2 diabetes is a chronic metabolic derangement that results from defects in both insulin action and secretion. New thiazolidinedione insulin sensitizers have been recently launched. New approaches with mechanisms different from current therapies are being explored, including novel ligands of peroxisome proliferator-activated receptor, glucagon receptor antagonists, dipeptidyl peptidase IV inhibitors, and insulin receptor activators. Topics: Diabetes Mellitus, Type 2; Glucagon; Glucagon-Like Peptide 1; Glucose; Humans; Hypoglycemic Agents; Liver; Molecular Structure; Peptide Fragments; Protein Precursors; Protein Tyrosine Phosphatases; Receptor, Insulin; Receptors, Cytoplasmic and Nuclear; Receptors, Glucagon; Thiazoles; Thiazolidinediones; Transcription Factors | 2000 |
Is glucagon-like peptide 1 an incretin hormone?
Glucagon-like peptide-1 (GLP-1) was predicted, based on the proglucagon gene sequence. It is synthesised by specific post-translational processing in L cells (lower intestine) and secreted mainly as "truncated" GLP-1 [7-36 amide] in response to nutrient ingestion. Glucagon-like peptide-1 stimulates insulin secretion during hyperglycaemia, suppresses glucagon secretion, stimulates (pro)insulin biosynthesis and decelerates gastric emptying and acid secretion. On intracerebroventricular injection, GLP-1 reduces food intake in rodents. A GLP-1 receptor antagonist or GLP-1 antisera have been shown to reduce meal-stimulated insulin secretion in animals, suggesting that GLP-1 has a physiological "incretin" function (augmentation of postprandial insulin secretion due to intestinal hormones) for GLP-1. In healthy human subjects, exogenous GLP-1 slows gastric emptying. Consequently, postprandial insulin secretion is reduced, not augmented. Thus, a participation of this peptide in the incretin effect of non-diabetic humans has not been definitely proven. Nevertheless, it has potent insulinotropic activity, especially during hyperglycaemia. This suggests new therapeutic options for patients with Type II (non-insulin-dependent) diabetes mellitus. On the other hand, most L cells are located in the lower small intestine. Potent inhibitory actions of GLP-1 on upper gastrointestinal motor and digestive functions (e. g. gastric emptying and acid secretion) in response to nutrients placed into the ileal lumen, argue for a role of this peptide as an "ileal brake". Malassimilation and diarrhea leading to the erroneous presence of nutrients in the lower gut may, via GLP-1, delay gastric emptying and reduce upper gut motility and thereby prevent further caloric losses. Topics: Animals; Diabetes Mellitus, Type 2; Digestion; Gastric Emptying; Gastrointestinal Hormones; Gastrointestinal Motility; Glucagon; Glucagon-Like Peptide 1; Glucagon-Like Peptides; Humans; Insulin; Insulin Secretion; Peptide Fragments; Protein Precursors | 1999 |
Encapsulated, genetically engineered cells, secreting glucagon-like peptide-1 for the treatment of non-insulin-dependent diabetes mellitus.
Non-insulin-dependent, or type II, diabetes mellitus is characterized by a progressive impairment of glucose-induced insulin secretion by pancreatic beta cells and by a relative decreased sensitivity of target tissues to the action of this hormone. About one third of type II diabetic patients are treated with oral hypoglycemic agents to stimulate insulin secretion. These drugs however risk inducing hypoglycemia and, over time, lose their efficacy. An alternative treatment is the use of glucagon-like peptide-1 (GLP-1), a gut peptidic hormone with a strong insulinotropic activity. Its activity depends of the presence of normal blood glucose concentrations and therefore does not risk inducing hypoglycemia. GLP-1 can correct hyperglycemia in diabetic patients, even in those no longer responding to hypoglycemic agents. Because it is a peptide, GLP-1 must be administered by injection; this may prevent its wide therapeutic use. Here we propose to use cell lines genetically engineered to secrete a mutant form of GLP-1 which has a longer half-life in vivo but which is as potent as the wild-type peptide. The genetically engineered cells are then encapsulated in semi-permeable hollow fibers for implantation in diabetic hosts for constant, long-term, in situ delivery of the peptide. This approach may be a novel therapy for type II diabetes. Topics: Animals; Diabetes Mellitus, Type 2; Genetic Engineering; Glucagon; Glucagon-Like Peptide 1; Humans; Membranes, Artificial; Mice; Mutation; Peptide Fragments; Protein Precursors | 1999 |
Ileal [correction of ilial] transposition and enteroglucagon/GLP-1 in obesity (and diabetic?) surgery.
This is a review of intestinal glucagon, which is released when undigested food is in the terminal ileum.. In the early 1980s, Koopmans and Sclafani showed in fat rats that the transposition of a short segment of ileum to the duodenum would decrease weight just as effectively as intestinal bypass. Sarson and coworkers found elevated enteroglucagon after biliopancreatic diversion (BPD). Scopinaro has observed that patients with diabetes who undergo BPD are cured of diabetes and do not experience a recurrence. Näslund and associates showed recently a high level of plasma glucagon-like peptide (GLP-1) 20 years after jejunoileal bypass. GLP-1 has been shown to be an effective medication for treatment of type 2 diabetes mellitus (DM). It must be given parenterally. It has been used only in short, well-controlled studies.. It appears from all that is now known about GLP-1 that ileal transposition would be an ideal operation for treatment of type 2 DM. Release of enteroglucagon from the ileum has probably contributed to weight control in bypass operations for obesity, but the effect has been obscured by the associated malabsorption. The release of GLP-1 after meals has probably been beneficial to patients treated with gastric bypass who had type 2 DM. This is a recommendation for well-planned studies of ileal transposition in the treatment of type 2 DM and obesity. Ileal transposition is not recommended for general use until such studies have shown safety, efficacy, and the requirements for patient selection. Topics: Animals; Biliopancreatic Diversion; Diabetes Mellitus, Type 2; Glucagon; Glucagon-Like Peptide 1; Glucagon-Like Peptides; Humans; Ileum; Obesity, Morbid; Peptide Fragments; Protein Precursors; Rats | 1999 |
The use of insulin secretagogues in the treatment of type 2 diabetes.
Secretatogues are a class of agents that achieve their hypoglycemic effects through stimulating insulin release. They include the sulfonylureas, repaglinide, and the investigational agent glucagon-like peptide. The secretagogue agents have been studied extensively as monotherapy and in conjunction with other classes of oral agents, including alpha-glucosidase inhibitors, bijuanides, and thiazolidinediones, for the treatment of type 2 diabetes. This article reviews the pharmacodynamic and pharmacokinetic differences of the secretagogues, as well as the most recent clinical trials. Such information should be helpful when deciding which agent or agents will yield the best glycemic control for an individual patient. Topics: Acarbose; Carbamates; Chromans; Diabetes Mellitus, Type 2; Drug Therapy, Combination; Glucagon; Glucagon-Like Peptide 1; Humans; Hypoglycemic Agents; Metformin; Peptide Fragments; Piperidines; Protein Precursors; Risk Factors; Sulfonylurea Compounds; Thiazoles; Thiazolidinediones; Troglitazone | 1999 |
Present and potential future use of gene therapy for the treatment of non-insulin dependent diabetes mellitus (Review).
This review describes the latest approaches towards using gene therapy as a treatment for non-insulin dependent diabetes mellitus (NIDDM; Type 2 diabetes). We examine attempts to directly deliver the insulin gene to non-beta-cells, to improve insulin secretion from existing beta-cells and to develop ex vivo approaches to implanting genetically modified cells. Future research into the pathology of non-insulin dependent diabetes, combined with the latest developments in gene delivery systems, may potentially make gene therapy an attractive alternative NIDDM treatment in the future. Topics: Adult; Animals; Antigens, Neoplasm; Biomarkers, Tumor; Blood Glucose; Cell Transplantation; Diabetes Mellitus, Type 2; Gene Expression Regulation; Genes, Synthetic; Genetic Therapy; Genetic Vectors; Glucagon; Glucagon-Like Peptide 1; Glucokinase; Glucose Transporter Type 2; Homeodomain Proteins; Humans; Hyperinsulinism; Hypoglycemic Agents; Insulin; Insulin Resistance; Insulin Secretion; Islets of Langerhans; Islets of Langerhans Transplantation; Lectins, C-Type; Mice; Middle Aged; Monosaccharide Transport Proteins; Muscle Contraction; Nitric Oxide; Nitric Oxide Synthase; Nitric Oxide Synthase Type I; Pancreatitis-Associated Proteins; Peptide Fragments; Promoter Regions, Genetic; Protein Precursors; Proteins; Rats; Trans-Activators | 1999 |
[Hepatogenic diabetes--the current concepts of its pathophysiology and therapy].
Topics: Diabetes Mellitus; Diabetes Mellitus, Type 2; Gastrointestinal Hormones; Glucagon; Glucagon-Like Peptide 1; Glucagon-Like Peptides; Glucose; Humans; Hypoglycemic Agents; Insulin Resistance; Liver; Liver Diseases; Peptide Fragments; Receptor, Insulin | 1999 |
Research advances in the treatment of type 2 diabetes mellitus.
Topics: Chemistry, Pharmaceutical; Diabetes Mellitus, Type 2; Glucagon; Glucagon-Like Peptide 1; Humans; Hypoglycemic Agents; Insulin; Peptide Fragments; Protein Kinase C; Protein Precursors; Research; Thiazoles; Thiazolidinediones | 1999 |
Cellular regulation of islet hormone secretion by the incretin hormone glucagon-like peptide 1.
Glucagon-like peptide 1 is a gastrointestinally derived hormone with profound effects on nutrient-induced pancreatic hormone release. GLP-1 modulates insulin, glucagon and somatostatin secretion by binding to guanine nucleotide binding protein-coupled receptors resulting in the activation of adenylate cyclase and generation of cyclic adenosine monophosphate (cAMP). In the B-cell, cAMP, via activation of protein kinase A, interacts with a plethora of signal transduction processes including ion channel activity, intracellular Ca2+ handling and exocytosis of the insulin-containing granules. The stimulatory action of GLP-1 on insulin secretion, contrary to that of the currently used hypoglycaemic sulphonylureas, is glucose dependent and requires the presence of normal or elevated concentrations of the sugar. For this reason, GLP-1 attracts much interest as a possible novel principle for the treatment of human type-2 diabetes. Here we review the actions of GLP-1 on islet cell function and attempt to integrate current knowledge into a working model for the control of pancreatic hormone secretion. Topics: Animals; Calcium; Diabetes Mellitus, Type 2; Exocytosis; Glucagon; Glucagon-Like Peptide 1; Glucagon-Like Peptide-1 Receptor; Glucagon-Like Peptides; Humans; Ion Channels; Islets of Langerhans; Pancreatic Hormones; Peptide Fragments; Protein Precursors; Receptors, Glucagon | 1998 |
Glucagon-like peptides.
Proglucagon contains the sequence of two glucagon-like peptides, GLP-1 and GLP-2, secreted from enteroendocrine cells of the small and large intestine. GLP-1 lowers blood glucose in both NIDDM and IDDM patients and may be therapeutically useful for treatment of patients with diabetes. GLP-1 regulates blood glucose via stimulation of glucose-dependent insulin secretion, inhibition of gastric emptying, and inhibition of glucagon secretion. GLP-1 may also regulate glycogen synthesis in adipose tissue and muscle; however, the mechanism for these peripheral effects remains unclear. GLP-1 is produced in the brain, and intracerebroventricular GLP-1 in rodents is a potent inhibitor of food and water intake. The short duration of action of GLP-1 may be accounted for in part by the enzyme dipeptidyl peptidase 4 (DPP-IV), which cleaves GLP-1 at the NH2-terminus; hence GLP-1 analogs or the lizard peptide exendin-4 that are resistant to DPP-IV cleavage may be more potent GLP-1 molecules in vivo. GLP-2 has recently been shown to display intestinal growth factor activity in rodents, raising the possibility that GLP-2 may be therapeutically useful for enhancement of mucosal regeneration in patients with intestinal disease. This review discusses recent advances in our understanding of the biological activity of the glucagon-like peptides. Topics: Amino Acid Sequence; Animals; Diabetes Mellitus, Type 1; Diabetes Mellitus, Type 2; Glucagon; Glucagon-Like Peptide 1; Glucagon-Like Peptide 2; Glucagon-Like Peptide-1 Receptor; Humans; Molecular Sequence Data; Peptide Fragments; Peptides; Protein Precursors; Receptors, Glucagon | 1998 |
Dietary interventions in noninsulin-dependent diabetes mellitus: new approaches.
Topics: Cholecystokinin; Diabetes Mellitus, Type 2; Eating; Glucagon; Glucagon-Like Peptide 1; Humans; Insulin; Insulin Secretion; Peptide Fragments; Protein Precursors | 1998 |
[GLP-1 (7-36) amide [GLIP-glucagon like insulinotropic peptide] as a potential treatment for NIDDM].
Topics: Animals; Clinical Trials as Topic; Diabetes Mellitus, Type 2; Glucagon; Glucagon-Like Peptide 1; Glucagon-Like Peptides; Humans; Peptide Fragments | 1998 |
Inhibition of the activity of dipeptidyl-peptidase IV as a treatment for type 2 diabetes.
The insulinotropic hormone, glucagon-like peptide 1 (GLP-1), which has been proposed as a new treatment for type 2 diabetes, is metabolized extremely rapidly by the ubiquitous enzyme, dipeptidyl peptidase IV (DPP-IV), resulting in the formation of a metabolite, which may act as an antagonist at the GLP-1 receptor. Because of this, the effects of single injections of GLP-1 are short-lasting, and for full demonstration of its antidiabetogenic effects, continuous intravenous infusion is required. To exploit the therapeutic potential of GLP-1 clinically, we here propose the use of specific inhibitors of DPP-IV. We have demonstrated that the administration of such inhibitors may completely protect exogenous GLP-1 from DPP-IV-mediated degradation, thereby greatly enhancing its insulinotropic effect, and provided evidence that endogenous GLP-1 may be equally protected. Preliminary studies by others in glucose-intolerant experimental animals have shown that DPP-IV inhibition greatly ameliorates the condition. GLP-1 has multifaceted actions, which include stimulation of insulin gene expression, trophic effects on the beta-cells, inhibition of glucagon secretion, promotion of satiety, inhibition of food intake, and slowing of gastric emptying, all of which contribute to normalizing elevated glucose levels. Because of this, we predict that inhibition of DPP-IV, which will elevate the levels of active GLP-1 and reduce the levels of the antagonistic metabolite, may be useful to treat impaired glucose tolerance and perhaps prevent transition to type 2 diabetes. The actions of DPP-IV, other than degradation of GLP-1, particularly in the immune system are discussed, but it is concluded that side effects of inhibition therapy are likely to be mild. Thus, DPP-IV inhibition may be an effective supplement to diet and exercise treatment in attempts to prevent the deterioration of glucose metabolism associated with the Western lifestyle. Topics: Diabetes Mellitus, Type 2; Dipeptidyl Peptidase 4; Glucagon; Glucagon-Like Peptide 1; Humans; Peptide Fragments; Peptides; Protease Inhibitors; Protein Precursors | 1998 |
Glucagon-like peptide 1 (GLP-1): a potent gut hormone with a possible therapeutic perspective.
Glucagon-like peptide 1 (GLP-1) is a physiological incretin hormone from the lower gastrointestinal tract, partially explaining the augmented insulin response after oral compared to intravenous glucose administration in normal humans. In addition, GLP-1 also lowers glucagon concentrations, slows gastric emptying, stimulates (pro)insulin biosynthesis, and reduces food intake upon intracerebroventricular administration in animals. Therefore, GLP-1 offers some interesting perspective for the treatment of type 2, and perhaps also for type 1 diabetic patients. The other incretin hormone, gastric inhibitory polypeptide (GIP), has lost almost all its activity in type-2 diabetic patients. In contrast, GLP-1 glucose-dependently stimulates insulin secretion in type-2 diabetic patients and exogenous administration of GLP-1 ([7-37] or [7-36 amide]) in doses elevating plasma concentrations to approximately three to four times physiological postprandial levels fully normalizes fasting hyperglycaemia and reduces postprandial glycaemic increments. Due to rapid proteolytic cleavage, which results in an inactive or even antagonistic fragment. GLP-1 [9-36 amide], and to rapid elimination, the half-life of GLP-1 is too short to maintain therapeutic plasma levels for sufficient periods by subcutaneous injections of the natural peptide hormone. Current research aims to characterize GLP-1 analogues with more suitable pharmacokinetic properties than the original peptide. Given the large amount of GLP-1 present in L cells, it also appears worthwhile to search for more agents that could 'mobilize' this endogenous pool of GLP-1. Topics: Animals; Cerebral Ventricles; Diabetes Mellitus, Type 1; Diabetes Mellitus, Type 2; Feeding Behavior; Gastric Emptying; Glucagon; Glucagon-Like Peptide 1; Glucose; Humans; Insulin; Models, Biological; Peptide Fragments; Proinsulin; Protein Precursors | 1998 |
On the treatment of diabetes mellitus with glucagon-like peptide-1.
As a therapeutic principle, the insulinotropic peptide, GLP-1, of the secretin-glucagon family of peptides, has turned out to possess some remarkably attractive properties, including the capability of normalizing blood glucose concentrations in patients with non-insulin-dependent diabetes mellitus and promoting satiety and reducing food intake in healthy volunteers. Because of rapid and extensive metabolization, the peptide is not immediately clinically applicable and, as a therapeutic principle, GLP-1 is still in its infancy. Some possible avenues for circumventing these difficulties are the development of DPP-IV-resistant analogs, the inhibition of DPP-IV, enhancement of GLP-1 secretion, GLP delivery systems using continuous subcutaneous infusion or buccal tablets, GLP-1 absorption, and orally active, stable analogs. It seems likely that one or more of these approaches could result in a clinically useful development program. Topics: Administration, Oral; Animals; Appetite Depressants; Diabetes Mellitus, Type 2; Dipeptidyl Peptidase 4; Glucagon; Glucagon-Like Peptide 1; Humans; Hypoglycemic Agents; Peptide Fragments; Protein Precursors | 1998 |
Glucagon-like peptide 1 (GLP-1) as a new therapeutic approach for type 2-diabetes.
Glucagon-like peptide 1 (GLP-1) is a physiological incretin hormone in normal humans explaining in part the augmented insulin response after oral versus intravenous glucose administration. In addition, GLP-1 also lowers glucagon concentrations, slows gastric emptying, stimulates (pro)insulin biosynthesis, reduces food intake upon intracerebroventricular administration in animals, and may, in addition, enhance insulin sensitivity. Therefore, GLP-1, in many aspects, opposes the Type 2-diabetic phenotype characterized by disturbed glucose-induced insulin secretory capacity, hyperglucagonaemia, moderate insulin deficiency, accelerated gastric emptying, overeating (obesity) and insulin resistance. The other incretin hormone, gastric inhibitory polypeptide (GIP), has lost almost all its activity in Type 2-diabetic patients. In contrast, GLP-1 glucose-dependently stimulates insulin secretion in diet- and sulfonylurea-treated Type 2-diabetic patients and also in patients under insulin therapy long after sulfonylurea secondary failure. Exogenous administration of GLP-1 ([7-37] or [7-36 amide]) in doses elevating plasma concentrations to approximately 3-4 fold physiological postprandial levels fully normalizes fasting hyperglycaemia in Type 2-diabetic patients. The half life of GLP-1 is too short to maintain therapeutic plasma levels for sufficient periods by subcutaneous injections. Current research activities aim at finding GLP-1 analogues with more suitable pharmacokinetic properties than the original peptide. Another approach could be the augmentation of endogenous release of GLP-1, which is abundant in L cells of the lower small intestine and the colon. Interference with sucrose digestion using alpha-glucosidase inhibition moves nutrients into distal parts of the gastrointestinal tract and, thereby, prolongs and augments GLP-1 release. Enprostil, a prostaglandin E2 analogue, fully suppresses GIP responses, while only marginally affecting insulin secretion and glucose tolerance after oral glucose, suggesting compensatory hypersecretion of additional insulinotropic peptides, possibly including GLP-1. Given the large amount of GLP-1 present in L cells, it appears worthwhile to look for more agents that could 'mobilize' this endogenous pool of the 'antidiabetogenic' gut hormone GLP-1. Topics: Blood Glucose; Diabetes Mellitus, Type 2; Enzyme Inhibitors; Gastrointestinal Hormones; Glucagon-Like Peptide 1; Glycoside Hydrolase Inhibitors; Humans; Peptides | 1997 |
[Glucagon-like peptide-1 (GLP-1) receptor gene].
Topics: Diabetes Mellitus, Type 2; Glucagon; Glucagon-Like Peptide 1; Glucagon-Like Peptide-1 Receptor; Humans; Peptide Fragments; Protein Precursors; Receptors, Glucagon | 1997 |
Glucagon-like peptide-1 structure, function and potential use for NIDDM.
Basic research on the cellular mechanisms that control the expression of the gene encoding glucagon has led to the discovery of proglucagon. This precursor is processed by tissue-specific proteolysis to produce glucagon in pancreatic alpha-cells and a glucagon-like peptide-1 (GLP-1) in the intestine. GLP-1 is a hormone that is released by intestinal cells into the circulation in response to food intake. GLP-1 and gastric inhibitory peptide (GIP) which has also been termed glucose-dependent insulinotropic peptide appear to account for most of the incretin effect in the augmentation of glucose-stimulated insulin secretion. These two hormones have specific beta-cell receptors that are coupled to GTP binding proteins to induce production of cyclic AMP and activation of cyclic AMP-dependent protein kinase. It is proposed that at least one factor contributing to the pathogenesis of non-insulin-dependent diabetes mellitus (NIDDM) is desensitization of the GLP-1 receptor on beta-cells. At pharmacological doses, infusion of GLP-1, but not of GLP, can improve and enhance postprandial insulin response in NIDDM patients. Agonists of GLP-1 receptor have been proposed as new potential therapeutic agents in NIDDM patients. The observations that GLP-1 induces both secretion and production of insulin, and that its activities are mainly glucose-dependent, led to the suggestion that GLP-1 may present a unique advantage over sulfonylurea drugs in the treatment of NIDDM. Topics: Diabetes Mellitus, Type 2; Gastric Emptying; Glucagon; Glucagon-Like Peptide 1; Glucagon-Like Peptide-1 Receptor; Humans; Insulin; Insulin Resistance; Insulin Secretion; Islets of Langerhans; Peptide Fragments; Protein Precursors; Receptors, Glucagon | 1997 |
The metabolic role of GIP: physiology and pathology.
Topics: Adipocytes; Animals; Diabetes Mellitus, Type 2; Diet; Digestive System Physiological Phenomena; Energy Metabolism; Gastric Inhibitory Polypeptide; Glucagon; Glucagon-Like Peptide 1; Glucagon-Like Peptide-1 Receptor; Humans; Insulin; Mice; Mice, Inbred NOD; Models, Biological; Obesity; Organ Specificity; Peptide Fragments; Protein Precursors; Rats; Rats, Zucker; Receptors, Gastrointestinal Hormone; Receptors, Glucagon | 1996 |
Nutrient-induced secretion and metabolic effects of glucose-dependent insulinotropic polypeptide and glucagon-like peptide-1.
Topics: Adaptation, Physiological; Adipose Tissue; Animals; Coronary Disease; Diabetes Mellitus, Type 2; Gastric Inhibitory Polypeptide; Glucagon; Glucagon-Like Peptide 1; Glucagon-Like Peptides; Humans; Obesity; Peptide Fragments | 1996 |
Therapeutic potential of glucagon-like peptide 1 in type 2 diabetes.
GLP-1 is a peptide hormone which has been shown to have a variety of antidiabetic actions that could help to reduce glycaemia especially in Type 2 diabetic patients: (1) It produces glucose-dependent stimulation of insulin secretion, and (2) inhibition of glucagon secretion; (3) there is evidence that it increases the rate of (pro)-insulin synthesis and it may also increase insulin sensitivity; (4) it slows the rate of gastric emptying for liquid meals, and possibly also for solid meals; (5) it appears to act within the central nervous system to suppress appetite. These actions of GLP-1 oppose a number of the abnormalities that are commonly observed in patients with Type 2 diabetes. Many facets of Type 2 diabetes, therefore, could be envisaged as a consequence of a lack of GLP-1 effects; they appear to be corrected by the exogenous administration of this gut peptide in short-term experiments. Future activities will aim at the therapeutic exploitation of this pharmacological potential by modifying GLP-1 and its ways of administration to suit the practical needs of patients with Type 2 diabetes. Topics: Animals; Blood Glucose; Diabetes Mellitus, Type 2; Gastric Emptying; Glucagon; Glucagon-Like Peptide 1; Glucagon-Like Peptides; Humans; Hypoglycemic Agents; Infusions, Intravenous; Injections, Subcutaneous; Peptide Fragments; Postprandial Period; Protein Precursors | 1996 |
GLP-1 in NIDDM.
Glucagon-like peptide-1 (GLP-1), a product of intestinal expression of the glucagon gene, is a potent insulinotropic hormone released in response to ingestion of meals. Specific GLP-1 receptors, G-protein coupled receptors that activate adenylate cyclase are located in the pancreatic islets and also in brain and various other tissues. GLP-1 also inhibits glucagon secretion and therefore inhibits hepatic glucose production and decreases blood glucose. However, as its effects on insulin secretion are glucose dependent, its effect on blood glucose in self-limiting. Because of these actions GLP-1 administration can completely normalize the hyperglycaemia of NIDDM without a risk of hypoglycaemia and GLP-1 is therefore currently considered as a therapeutic agent. GLP-1 also inhibits gastrointestinal secretion and motility, presumably via interaction with cerebral receptors. This effect may help curtail meal-induced glucose excursions, but may also limit its use. Being a peptide GLP-1 requires parenteral administration, but because of rapid enzymatic degradation its bioavailability is low. Current research efforts are aimed at the development of orally active GLP-1 analogues. Topics: Animals; Blood Glucose; Brain; Diabetes Mellitus, Type 2; Gastric Emptying; Glucagon; Glucagon-Like Peptide 1; Humans; Hypoglycemic Agents; Insulin; Insulin Secretion; Intestine, Small; Islets of Langerhans; Pancreas; Peptide Fragments; Protein Precursors | 1996 |
Regulation, perturbation, and correction of metabolic events in pancreatic islets.
The physiological regulation of nutrient catabolism in islet cells, its perturbation in non-insulin-dependent diabetes mellitus, and the tools available to compensate for such a perturbation are reviewed. In terms of physiology, emphasis is placed on the relevance of glucokinase to hexose-induced insulin release, protein-to-protein interaction and enzyme-to-enzyme channelling, and the preferential stimulation of mitochondrial oxidative events in glucose-stimulated B-cells. In terms of pathology, attention is drawn to the deficiency of FAD-linked mitochondrial glycerophosphate dehydrogenase. Last, as far as therapeutic aspects are concerned, the potential usefulness of hypoglycemic sulfonylureas and meglitinide analogs, adenosine analogs, non-glucidic nutrients, and GLP-1 is underlined. Topics: Adenosine; Animals; Diabetes Mellitus, Type 2; Glucagon; Glucagon-Like Peptide 1; Glucokinase; Glycerolphosphate Dehydrogenase; Hexoses; Homeostasis; Humans; Hypoglycemic Agents; Insulin; Insulin Secretion; Islets of Langerhans; Mitochondria; Oxidative Phosphorylation; Peptide Fragments; Protein Precursors; Sulfonylurea Compounds | 1996 |
Human studies with glucagon-like-peptide-1: potential of the gut hormone for clinical use.
So far, a wealth of data originating from in vitro or animal experiments has been collected supporting the concept that the gut hormone, glucagon-like peptide-1 (GLP-1) may serve as a model molecule for the design of a new drug for the treatment of diabetes mellitus. This is supported by observations that GLP-1 has potent insulinotropic action in patients with non-insulin-dependent diabetes mellitus (NIDDM). It enhances beta-cell sensitivity to glucose stimulated insulin secretion. GLP-1 may also have a role in the treatment of impaired glucose tolerance, where the beta-cell is already insensitive to changes in plasma glucose concentrations. It may, as has previously been shown in animal models of 'prediabetes', delay the progressive decline in glucose tolerance to NIDDM. The glucose-dependent action of this peptide is an important feature in the treatment of NIDDM as it will protect against hypoglycaemic reactions, the most serious acute side-effect of antidiabetic therapy. Glucose utilization may be enhanced which would improve metabolic control in both NIDDM and IDDM. A glucagon lowering effect will further enhance metabolic control. This article reviews current experiences of the effects of GLP-1 in human studies. It points out the outcomes and limitations of previous trials and discusses future directions for the investigation of its potential use as a new agent in diabetes treatment. Topics: Animals; Blood Glucose; Diabetes Mellitus, Type 2; Drug Design; Gastric Emptying; Glucagon; Glucagon-Like Peptide 1; Humans; Hypoglycemic Agents; Insulin; Insulin Secretion; Islets of Langerhans; Peptide Fragments; Protein Precursors | 1996 |
New treatments for patients with type 2 diabetes mellitus.
In subjects with type 2 diabetes, both defects of insulin secretion and insulin resistance contribute to the development of hyperglycaemia. The major goals of treatment are to optimise blood glucose control, and normalise the associated lipid disturbances and elevated blood pressure. Pharmacologic treatment is often necessary. This paper discusses new forms of oral treatment for subjects with type 2 diabetes. These include a new sulphonylurea compound glimepiride (Amaryl), which binds to a different protein of the putative sulphonylurea receptor than glibenclamide, and seems to have a lower risk of hypoglycaemia. A new class of drugs with insulin secretory capacity, of which repaglinide (NovoNorm) is the leading compound, is now in phase III clinical trials. Alpha-glucosidase inhibitors reversibly inhibit alpha-glucosidase enzymes in the small intestine, which delays cleavage of oligo- and disaccharides to monosaccharides. This leads to a delayed and reduced blood glucose rise after a meal. Two compounds are in development or have been marketed, ie, miglitol and acarbose (Glucobay). Another new class of drugs is the thiazolidine-diones, which seem to work by enhancing insulin action. The 'insulin sensitising' effects of the leading compounds, troglitazone and BRL 49653C, do not involve any effect on insulin secretion. These drugs also seem to beneficially influence serum cholesterol and triglyceride levels. Oral antihyperglycaemic agents can be used only during a limited period of time in most patients, after which the diabetic state 'worsens' and insulin therapy has to be started. In this light, two new forms of treatment which require subcutaneous injections are also discussed: the synthetic human amylin analogue AC137 (pramlintide) and glucagon-like peptide-1 (7-36)-amide, a strong glucose-dependent stimulator of insulin secretion. It remains to be seen whether these compounds can be developed further for clinical use in patients with diabetes. Topics: Amyloid; Diabetes Mellitus, Type 2; Glucagon; Glucagon-Like Peptide 1; Glycoside Hydrolase Inhibitors; Humans; Hypoglycemic Agents; Insulin; Insulin Resistance; Insulin Secretion; Islet Amyloid Polypeptide; Peptide Fragments; Protein Precursors; Sulfonylurea Compounds | 1996 |
The genetics of non-insulin-dependent diabetes mellitus.
Topics: Amyloid; Animals; Base Sequence; Carrier Proteins; Chromosome Mapping; Cloning, Molecular; Diabetes Mellitus, Type 2; DNA, Mitochondrial; Fatty Acid-Binding Protein 7; Fatty Acid-Binding Proteins; Glucagon; Glucagon-Like Peptide 1; Glucokinase; Glucose Transporter Type 4; Glycogen Synthase; Humans; Insulin; Insulin Resistance; Islet Amyloid Polypeptide; Molecular Sequence Data; Monosaccharide Transport Proteins; Muscle Proteins; Neoplasm Proteins; Peptide Fragments; Protein Precursors; Receptor, Insulin; Selection, Genetic; Tumor Suppressor Proteins | 1995 |
Glucagon-like peptide-1 and control of insulin secretion.
Although glucose is the major regulator of insulin secretion by pancreatic beta cells, its action is modulated by several neural and hormonal stimuli. In particular, hormones secreted by intestinal endocrine cells stimulate glucose-induced insulin secretion very potently after nutrient absorption. These hormones, called gluco-incretins or insulinotropic hormones, are major regulators of postprandial glucose homeostasis. The main gluco-incretins are GIP (gastric inhibitory polypeptide or glucose-dependent insulinotropic polypeptide) and GLP-1 (glucagon-like polypeptide-1). The secretion of GIP, a 42 amino acid polypeptide secreted by duodenal K cells, is triggered by fat and glucose. GIP stimulation of insulin secretion depends on the presence of specific beta-cell receptors and requires glucose at a concentration at least equal to or higher than the normoglycaemic level of approximately 5 mM. GIP accounts for about 50% of incretin activity, and the rest may be due to GLP-1 which is produced by proteolytic processing of the preproglucagon molecule in intestinal L cells. GLP-1 is the most potent gluco-incretin characterized so far. As with GIP, its stimulatory action requires a specific membrane receptor and normal or elevated glucose concentrations. Contrary to GIP, the incretin effect of GLP-1 is maintained in non-insulin-dependent diabetic patients. This peptide or agonists of its beta-cell receptor could provide new therapeutic tools for the treatment of Type II diabetic hyperglycaemia. Topics: Animals; Diabetes Mellitus, Type 2; Gastric Inhibitory Polypeptide; Glucagon; Glucagon-Like Peptide 1; Glucagon-Like Peptide-1 Receptor; Humans; Insulin; Insulin Secretion; Peptide Fragments; Protein Precursors; Receptors, Glucagon; Secretory Rate; Signal Transduction | 1995 |
Intestinal effects of alpha-glucosidase inhibitors: absorption of nutrients and enterohormonal changes.
The present paper addresses the question how alpha-glucosidase inhibitors affect glucose homeostasis. To facilitate this already established data on the effects of induced malabsorption on gut hormones such as gastric inhibitory polypeptide (GIP) in connection with preliminary findings which deal with the new incretin hormone glucagon-like peptide 1 (7-36) amide (GLP-1) are discussed. To emphasize the possibly important impact of a regulated GLP-1 release in response to glucosidase inhibitor treatment we evaluate the recently introduced concept of 'glucose competence' of pancreatic beta-cells. The slowing of nutrient (i.e. glucose) absorption by therapeutic means (for example, acarbose) could supplement a new approach in the treatment of type 2 diabetics which would utilize the well-preserved insulinotropic activity of GLP-1 in these patients, its glucagon-lowering effect, and its possible inhibition of gastric emptying rates, the latter helping to reduce the requirement for rapid insulin secretory responses as is intended while using alpha-glucosidase inhibitor treatment. Topics: Animals; Diabetes Mellitus, Type 2; Dietary Carbohydrates; Gastric Inhibitory Polypeptide; Gastrointestinal Hormones; Glucagon-Like Peptide 1; Glucose; Glycoside Hydrolase Inhibitors; Homeostasis; Humans; Hypoglycemic Agents; Intestinal Absorption; Models, Biological; Peptides | 1994 |
[GLP-1 and the control of insulin secretion].
Topics: Animals; Diabetes Mellitus, Type 2; Glucagon; Glucagon-Like Peptide 1; Humans; Insulin; Insulin Secretion; Peptide Fragments; Protein Precursors; Signal Transduction; Structure-Activity Relationship | 1994 |
["Glucagon-like peptide I": a therapeutic alternative for diabetes mellitus?].
Topics: Animals; B-Lymphocytes; Diabetes Mellitus, Type 2; Glucagon; Glucagon-Like Peptide 1; Glucagon-Like Peptide-1 Receptor; Humans; Insulin; Insulin Secretion; Peptide Fragments; Protein Precursors; Rats; Receptors, Cell Surface; Receptors, Glucagon | 1994 |
The incretin notion and its relevance to diabetes.
Basic research on the cellular mechanisms that control the expression of the gene encoding glucagon has led to the discovery of proglucagon, which is processed alternatively by tissue-specific proteolysis to produce glucagon in the pancreatic alpha cells and a GLP-1 in the intestines. GLP-1 hormone is released into the circulation from intestinal L cells in response to meals and is the most potent incretin hormone known; GLP-1 and GIP appear to account for most, if not all, of the intestinal incretin effect in the augmentation of glucose-stimulated insulin secretion. Analyses of the mechanisms of action of GLP-1 and of glucose on isolated cultured rat beta cells using patch-clamp techniques to record ion channel activities has led to the glucose competence concept in which the combined glucose-signaling and GLP-1/cAMP-signaling pathways are required to affect depolarization of beta cells and to thereby stimulate insulin secretion. It is hypothesized that, among other possible target channels, the K-ATP channel is key first event in GLP-1/glucose-mediated activation of the beta cell secretory response. It is proposed that at least one factor contributing to the pathogenesis of NIDDM is a desensitization of the GLP-1 receptor on beta cells induced by the hypersecretion of GLP-1. Because of the discoveries that GLP-1 stimulates both secretion and production of insulin, and that the actions of GLP-1 are entirely glucose-dependent, GLP-1 may provide unique advantages over the sulfonylurea drugs in the treatment of NIDDM. Topics: Amino Acid Sequence; Animals; Diabetes Mellitus, Type 1; Diabetes Mellitus, Type 2; Gastric Inhibitory Polypeptide; Glucagon; Glucagon-Like Peptide 1; Glucose; Humans; Insulin; Insulin Secretion; Molecular Sequence Data; Peptide Fragments; Protein Precursors | 1993 |
[Dysfunction of the pancreatic beta cells observed in non-insulin-dependent diabetes].
Topics: Blood Glucose; Diabetes Mellitus, Type 2; Gastric Inhibitory Polypeptide; Glucagon; Glucagon-Like Peptide 1; Glucose Intolerance; Insulin; Insulin Secretion; Islets of Langerhans; Monosaccharide Transport Proteins; Peptide Fragments; Protein Precursors | 1993 |
Glucagon-like peptide-I and the control of insulin secretion in the normal state and in NIDDM.
Potentiation of glucose-induced insulin secretion by intestinal factors has been described for many years. Today, two major peptides with potent insulinotropic action have been recognized: gastric inhibitory peptide and truncated forms of glucagon-like peptide I, GLP-I(7-37) or the related GLP-I(7-36)amide. These hormones have specific beta-cell receptors that are coupled to production of cAMP and activation of cAMP-dependent protein kinase. Elevation in intracellular cAMP levels is required to mediate the glucoincretin effect of these hormones: the potentiation of insulin secretion in the presence of stimulatory concentrations of glucose. In addition, circulating glucoincretins maintain basal levels of cAMP, which are necessary to keep beta-cells in a glucose-competent state. Interactions between glucoincretin signaling and glucose-induced insulin secretion may result from the phosphorylation of key elements of the glucose signaling pathway by cAMP-dependent protein kinase. These include the ATP-dependent K+ channel, the Ca++ channel, or elements of the secretory machinery itself. In NIDDM, the glucoincretin effect is reduced. However, basal or stimulated gastric inhibitory peptide and glucagon-like peptide I levels are normal or even elevated, suggesting that signals induced by these hormones on the beta-cells are probably altered. At pharmacological doses, infusion of glucagon-like peptide I but not gastric inhibitory peptide, can ameliorate postprandial insulin secretory response in NIDDM patients. Agonists of the glucagon-like peptide I receptor have been proposed as new therapeutic agents in NIDDM. Topics: Animals; Cloning, Molecular; Diabetes Mellitus, Type 2; Glucagon; Glucagon-Like Peptide 1; Glucagon-Like Peptides; Humans; Insulin; Insulin Secretion; Islets of Langerhans; Peptide Fragments; Peptides; Protein Precursors; Signal Transduction | 1993 |
Entero-insular axis and diabetes mellitus.
1. The incretin effect (i.e. the difference between the insulin response after oral and i.v. glucose) is reduced in type 2 diabetes although GIP secretion is normal or exaggerated. This suggests an insensitivity of the diabetic B-cell to GIP. However, it could also indicate the lack of another not yet defined "incretin". 2. While CCK is a potent incretin in rats and dogs, physiological concentrations of this hormone do not stimulate insulin secretion in man in presence of elevated blood levels of glucose or phenylalanine in the physiological range. It also does not interact with GIP. 3. Glucagon-like peptide I (7-36) is a potent glucose-dependent stimulator of insulin secretion in animals and man. Preliminary data suggest release after oral glucose despite localization of the GLPI containing cells predominantly in the ileum and colon. More data are needed before GLPI (7-36) can be regarded as a physiological incretin and its role in type 2 diabetes assessed. Topics: Animals; Cholecystokinin; Diabetes Mellitus, Type 2; Gastric Inhibitory Polypeptide; Glucagon; Glucagon-Like Peptide 1; Glucagon-Like Peptides; Humans; Insulin; Insulin Secretion; Intestines; Islets of Langerhans; Peptide Fragments | 1992 |
[Various molecular mechanisms involved in the pathogenesis of type II diabetes and their potential therapeutic importance].
The pancreatic beta cell presents functional abnormalities in the early stages of development of non-insulin dependent diabetes mellitus (NIDDM). The disappearance of the first phase of insulin secretion induced by a glucose load is a early marker of NIDDM. This abnormality could be secondary to the low expression of the pancreatic glucose transporter GLUT2. Together with the glucokinase enzyme, GLUT2 is responsible for proper beta cell sensing of the extracellular glucose levels. In NIDDM, the GLUT2 mRNA levels are low, a fact which suggests a transcriptional defect of the GLUT2 gene. The first phase of glucose-induced insulin secretion by the beta pancreatic cell can be partly restored by the administration of a peptide discovered by a molecular approach, the glucagon-like peptide 1 (GLP-1). The gene encoding for the glucagon is expressed in a cell-specific manner in the A cells of the pancreatic islet and the L cells of the intestinal tract. The maturation process of the propeptide encoded by the glucagon gene is different in the two cells: the glucagon is the main hormone produced by the A cells whereas the glucagon-like peptide 1 (GLP-1) is the major peptide synthesized by the L cells of the intestine. GLP-1 is an incretin hormone and is at present the most potent insulinotropic peptide. The first results of the administration of GLP-1 to normal volunteers and diabetic patients are promising and may be a new therapeutic approach to treating diabetic patients. Topics: Diabetes Mellitus, Type 2; Glucagon; Glucagon-Like Peptide 1; Humans; Insulin; Insulin Secretion; Islets of Langerhans; Monosaccharide Transport Proteins; Peptide Fragments; Protein Precursors; RNA, Messenger; Transcription, Genetic | 1992 |
469 trial(s) available for glucagon-like-peptide-1 and Diabetes-Mellitus--Type-2
Article | Year |
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Effect of Various Dosing Schedules on the Pharmacokinetics of Oral Semaglutide: A Randomised Trial in Healthy Subjects.
Prescribing information instructs taking oral semaglutide (a glucagon-like peptide-1 analogue) in the fasting state, followed by a post-dose fasting period of ≥ 30 min. This trial compared the recommended dosing schedule with alternative schedules.. This was a randomised, single-centre, multiple-dose, open-label, five-armed, parallel-group trial in healthy subjects who received once-daily oral semaglutide (3 mg for 5 days followed by 7 mg for 5 days). Subjects (n = 156) were randomised to five dosing schedules: 2-, 4-, or 6-h pre-dose fast followed by a 30-min post-dose fast (treatment arms: 2 h-30 min, 4-30 min, 6 h-30 min); 2-h pre-dose fast followed by an overnight post-dose fast (treatment arm: 2 h-night); or overnight pre-dose fast followed by a 30-min post-dose fast (reference arm: night-30 min). Semaglutide plasma concentration was measured regularly until 24 h after the 10th dose. Endpoints included area under the semaglutide plasma concentration-time curve during a 24-h interval after the 10th dose (AUC. Compared with an overnight pre-dose fast (reference arm: night-30 min), shorter pre-dose fasting times in the 2 h-night, 2 h-30 min, 4 h-30 min, and 6 h-30 min treatment arms resulted in significantly lower semaglutide AUC. This trial supports dosing oral semaglutide in accordance with prescribing information, which requires dosing in the fasting state.. ClinicalTrials.gov (NCT04513704); registered August 14, 2020.. Oral semaglutide is a human glucagon-like peptide-1 analogue that has been approved for the treatment of type 2 diabetes. It has been established that taking oral semaglutide with food or large volumes of water decreases absorption of the drug in the body. Current prescribing information instructs taking oral semaglutide on an empty stomach (known as the fasting state), with 120 mL/4 oz of water, then waiting for at least 30 min before consuming any food, water, or taking other oral medications. This study investigates whether different dosing schedules for oral semaglutide could potentially offer more flexibility to patients in the timing of their oral semaglutide dosing. The trial, conducted in healthy volunteers, compares the dosing schedule described in the prescribing information with different fasting times before (pre-dose) and after (post-dose) taking oral semaglutide during the day or evening, to see if there were any effects on the concentration of drug in the body. Compared to the recommended overnight fasting period, shorter pre-dose fasting periods of 2–6 h with a 30-min post-dose fast considerably reduced semaglutide exposure in the body. Similarly, semaglutide exposure was also reduced with a 2-h pre-dose fast combined with post-dose overnight fasting. These findings further support the current prescribing information, which states that patients should take their oral semaglutide dose after an overnight fast. Topics: Administration, Oral; Area Under Curve; Diabetes Mellitus, Type 2; Glucagon-Like Peptide 1; Glucagon-Like Peptides; Healthy Volunteers; Humans; Hypoglycemic Agents | 2023 |
Semaglutide 2·4 mg once weekly in patients with non-alcoholic steatohepatitis-related cirrhosis: a randomised, placebo-controlled phase 2 trial.
Patients with non-alcoholic steatohepatitis (NASH)-related cirrhosis are at high risk of liver-related and all-cause morbidity and mortality. We investigated the efficacy and safety of the glucagon-like peptide-1 analogue semaglutide in patients with NASH and compensated cirrhosis.. This double-blind, placebo-controlled phase 2 trial enrolled patients from 38 centres in Europe and the USA. Adults with biopsy-confirmed NASH-related cirrhosis and body-mass index (BMI) of 27 kg/m. 71 patients were enrolled between June 18, 2019, and April 22, 2021; 49 (69%) patients were female and 22 (31%) were male. Patients had a mean age of 59·5 years (SD 8·0) and mean BMI of 34·9 kg/m. In patients with NASH and compensated cirrhosis, semaglutide did not significantly improve fibrosis or achievement of NASH resolution versus placebo. No new safety concerns were raised.. Novo Nordisk A/S. Topics: Adult; Diabetes Mellitus, Type 2; Female; Glucagon-Like Peptide 1; Humans; Liver Cirrhosis; Male; Middle Aged; Non-alcoholic Fatty Liver Disease | 2023 |
Efficacy and Safety of Oral Small Molecule Glucagon-Like Peptide 1 Receptor Agonist Danuglipron for Glycemic Control Among Patients With Type 2 Diabetes: A Randomized Clinical Trial.
Currently available glucagon-like peptide 1 receptor (GLP-1R) agonists for treating type 2 diabetes (T2D) are peptide agonists that require subcutaneous administration or strict fasting requirements before and after oral administration.. To investigate the efficacy, safety, and tolerability of multiple dose levels of the novel, oral, small molecule GLP-1R agonist danuglipron over 16 weeks.. A phase 2b, double-blind, placebo-controlled, parallel-group, 6-group randomized clinical trial with 16-week double-blind treatment period and 4-week follow-up was conducted from July 7, 2020, to July 7, 2021. Adults with T2D inadequately controlled by diet and exercise, with or without metformin treatment, were enrolled from 97 clinical research sites in 8 countries or regions.. Participants received placebo or danuglipron, 2.5, 10, 40, 80, or 120 mg, all orally administered twice daily with food for 16 weeks. Weekly dose escalation steps were incorporated to achieve danuglipron doses of 40 mg or more twice daily.. Change from baseline in glycated hemoglobin (HbA1c, primary end point), fasting plasma glucose (FPG), and body weight were assessed at week 16. Safety was monitored throughout the study period, including a 4-week follow-up period.. Of 411 participants randomized and treated (mean [SD] age, 58.6 [9.3] years; 209 [51%] male), 316 (77%) completed treatment. For all danuglipron doses, HbA1c and FPG were statistically significantly reduced at week 16 vs placebo, with HbA1c reductions up to a least squares mean difference vs placebo of -1.16% (90% CI, -1.47% to -0.86%) for the 120-mg twice daily group and FPG reductions up to a least squares mean difference vs placebo of -33.24 mg/dL (90% CI, -45.63 to -20.84 mg/dL). Body weight was statistically significantly reduced at week 16 compared with placebo in the 80-mg twice daily and 120-mg twice daily groups only, with a least squares mean difference vs placebo of -2.04 kg (90% CI, -3.01 to -1.07 kg) for the 80-mg twice daily group and -4.17 kg (90% CI, -5.15 to -3.18 kg) for the 120-mg twice daily group. The most commonly reported adverse events were nausea, diarrhea, and vomiting.. In adults with T2D, danuglipron reduced HbA1c, FPG, and body weight at week 16 compared with placebo, with a tolerability profile consistent with the mechanism of action.. ClinicalTrials.gov Identifier: NCT03985293. Topics: Aged; Body Weight; Diabetes Mellitus, Type 2; Female; Glucagon-Like Peptide 1; Glycated Hemoglobin; Glycemic Control; Humans; Hypoglycemic Agents; Male; Middle Aged | 2023 |
Discovery of ecnoglutide - A novel, long-acting, cAMP-biased glucagon-like peptide-1 (GLP-1) analog.
Glucagon-like peptide (GLP)-1 is an incretin hormone that acts after food intake to stimulate insulin production, enhance satiety, and promote weight loss. Here we describe the discovery and characterization of ecnoglutide (XW003), a novel GLP-1 analog.. We engineered a series of GLP-1 peptide analogs with an alanine to valine substitution (Ala8Val) and a γGlu-2xAEEA linked C18 diacid fatty acid at various positions. Ecnoglutide was selected and characterized in GLP-1 receptor signaling assays in vitro, as well as in db/db mice and a diet induced obese (DIO) rat model. A Phase 1, double-blind, randomized, placebo-controlled, single (SAD) and multiple ascending dose (MAD) study was conducted to evaluate the safety, tolerability, and pharmacokinetics of subcutaneous ecnoglutide injection in healthy participants. SAD doses ranged from 0.03 to 1.0 mg; MAD doses ranged from 0.2 to 0.6 mg once weekly for 6 weeks (ClinicalTrials.gov Identifier: NCT04389775).. In vitro, ecnoglutide potently induced cAMP (EC. Ecnoglutide showed a favorable potency, pharmacokinetic, and tolerability profile, as well as a simplified manufacturing process. These results support the continued development of ecnoglutide for the treatment of type 2 diabetes and obesity. Topics: Animals; Body Weight; Diabetes Mellitus, Type 2; Glucagon-Like Peptide 1; Hypoglycemic Agents; Insulin; Mice; Obesity; Rats; Weight Loss | 2023 |
Safety and Efficacy of Liraglutide, 3.0 mg, Once Daily vs Placebo in Patients With Poor Weight Loss Following Metabolic Surgery: The BARI-OPTIMISE Randomized Clinical Trial.
Metabolic surgery leads to weight loss and improved health, but these outcomes are highly variable. Poor weight loss is associated with lower circulating levels of glucagon-like peptide-1 (GLP-1).. To assess the efficacy and safety of the GLP-1 receptor agonist, liraglutide, 3.0 mg, on percentage body weight reduction in patients with poor weight loss and suboptimal GLP-1 response after metabolic surgery.. The Evaluation of Liraglutide 3.0 mg in Patients With Poor Weight Loss and a Suboptimal Glucagon-Like Peptide-1 Response (BARI-OPTIMISE) randomized placebo-controlled trial recruited adult patients at least 1 year after metabolic surgery who had experienced 20% or less body weight loss from the day of surgery and a suboptimal nutrient-stimulated GLP-1 response from 2 hospitals in London, United Kingdom, between October 2018 and November 2019. Key exclusion criteria were type 1 diabetes; severe concomitant psychiatric, gastrointestinal, cardiac, kidney or metabolic disease; and use of insulin, GLP-1 receptor analogues, and medication that can affect weight. The study period was 24 weeks followed by a 4-week follow-up period. Last participant follow-up was completed in June 2020. All participants and clinical study personnel were blinded to treatment allocation. Of 154 assessed for eligibility, 70 met trial criteria and were included in the study, and 57 completed follow-up.. Liraglutide, 3.0 mg, once daily or placebo as an adjunct to lifestyle intervention with a 500-kcal daily energy deficit for 24 weeks, on a 1:1 allocation by computer-generated randomization sequence, stratified by surgery type (Roux-en-Y gastric bypass [RYGB] or sleeve gastrectomy [SG]) and type 2 diabetes status.. The primary outcome was change in percentage body weight from baseline to the end of the 24-week study period based on an intention-to-treat analysis. Participant safety was assessed through monitoring of biochemical parameters, including kidney and liver function, physical examination, and assessment for adverse events.. A total of 70 participants (mean [SD] age, 47.6 [10.7] years; 52 [74%] female) with a poor weight loss response following RYGB or SG were randomized to receive 3.0-mg liraglutide (n = 35) or placebo (n = 35). All participants received at least 1 dose of the trial drug. Eight participants discontinued treatment (4 per group), and 2 in the 3.0-mg liraglutide group and 1 in the placebo group were lost to follow-up. Due to COVID-19 restrictions, 3 participants in the 3.0-mg liraglutide group and 7 in the placebo group were unable to attend their final in-person assessment. Estimated change in mean (SD) percentage body weight from baseline to week 24 was -8.82 (4.94) with liraglutide, 3.0 mg (n = 31), vs -0.54 (3.32) with placebo (n = 26). The mean difference in percentage body weight change for liraglutide, 3.0 mg, vs placebo was -8.03 (95% CI, -10.39 to -5.66; P < .001). Adverse events, predominantly gastrointestinal, were more frequent with liraglutide, 3.0 mg (28 events [80%]), than placebo (20 events [57%]). There were no serious adverse events and no treatment-related deaths.. These findings support the use of adjuvant liraglutide, 3.0 mg, for weight management in patients with poor weight loss and suboptimal GLP-1 response after metabolic surgery.. ClinicalTrials.gov Identifier: NCT03341429. Topics: Adult; Bariatric Surgery; Diabetes Mellitus, Type 2; Double-Blind Method; Female; Glucagon-Like Peptide 1; Glucagon-Like Peptide-1 Receptor; Humans; Hypoglycemic Agents; Liraglutide; Male; Middle Aged; Treatment Outcome; Weight Loss | 2023 |
Diabetes Remission After LRYGBP With and Without Fundus Resection: a Randomized Clinical Trial.
Glycemic control, after metabolic surgery, is achieved in two stages, initially with neuroendocrine alterations and in the long-term with sustainable weight loss. The resection of the gastric fundus, as the major site of ghrelin production, is probably related with optimized glucose regulation. The aim of the present study is to investigate whether the modification of laparoscopic Roux-en-Y gastric bypass (LRYGBP) with fundus resection offers superior glycemic control, compared to typical LRYGBP.. Participants were 24 patients with body mass index (BMI) ≥40kg/m. Ninety-five percent of patients showed complete remission of T2DM after 12 months. LRYGBP+FR was not related with improved glycemic control, compared to LRYGBP. Ghrelin levels were not significantly reduced at 6 and 12 months after LRYGBP+FR. GLP-1 and PYY levels were remarkably increased postprandially in both groups at 6 and 12 months postoperatively (p<0.01). Patients who underwent LRYGBP+FR achieved a significantly lower BMI at 12 months in comparison to LRYGBP (p<0.05).. Fundus resection is not associated with improved glycemic regulation, compared to typical LRYGBP and the significant decrease in BMI after LRYGBP+FR has to be further confirmed with longer follow-up. Topics: Diabetes Mellitus, Type 2; Gastric Bypass; Gastrointestinal Hormones; Ghrelin; Glucagon-Like Peptide 1; Glucose; Humans; Laparoscopy; Obesity, Morbid; Peptide YY | 2023 |
Inclusion of Oat Polar Lipids in a Solid Breakfast Improves Glucose Tolerance, Triglyceridemia, and Gut Hormone Responses Postprandially and after a Standardized Second Meal: A Randomized Crossover Study in Healthy Subjects.
Previously, it has been indicated that oat polar lipids included in a liquid meal may have the potential to beneficially modulate various cardiometabolic variables. The purpose of this study was to evaluate the effects of oat polar lipids in a solid food matrix on acute and second meal glucose tolerance, blood lipids, and concentrations of gut-derived hormones. The oat polar lipids were consumed at breakfast and effects on the biomarkers were investigated in the postprandial period and following a standardized lunch. Twenty young, healthy subjects consumed in total four different breakfast meals in a crossover study design. The breakfasts consisted of 1. White wheat bread (WWB) with an added 7.5 g of oat polar lipids (PLL); 2. WWB with an added 15 g of oat polar lipids (PLH); 3. WWB with and added 16.6 g of rapeseed oil (RSO) as a representative of commonly consumed oils; and 4. WWB consumed alone, included as a reference. All products with added lipids contained equivalent amounts of fat (16.6 g) and available carbohydrates (50 g). Rapeseed oil was added to the oat polar lipid meals to equal 16.6 g of total fat. The standardized lunch was composed of WWB and meatballs and was served 3.5 h after the breakfast. Test variables (blood glucose, serum insulin, triglyceride (TG), free fatty acids (FFA), ghrelin, GLP-1, PYY, and GIP) were measured at fasting and repeatedly during the 5.5 h after ingestion of the breakfast. After breakfast, PLH substantially lowered postprandial glucose and insulin responses (iAUC 0-120 min) compared with RSO and WWB ( Topics: Avena; Blood Glucose; Breakfast; Cross-Over Studies; Diabetes Mellitus, Type 2; Dietary Fiber; Gastrointestinal Hormones; Ghrelin; Glucagon-Like Peptide 1; Healthy Volunteers; Humans; Insulin; Lipids; Meals; Postprandial Period; Rapeseed Oil | 2023 |
Effects of dulaglutide on alcohol consumption during smoking cessation.
BACKGROUNDAlcohol use disorder has a detrimental impact on global health and new treatment targets are needed. Preclinical studies show attenuating effects of glucagon-like peptide-1 (GLP-1) agonists on addiction-related behaviors in rodents and nonhuman primates. Some trials have shown an effect of GLP-1 agonism on reward processes in humans; however, results from clinical studies remain inconclusive.METHODSThis is a predefined secondary analysis of a double-blind, randomized, placebo-controlled trial evaluating the GLP-1 agonist dulaglutide as a therapy for smoking cessation. The main objective was to assess differences in alcohol consumption after 12 weeks of treatment with dulaglutide compared to placebo. The effect of dulaglutide on alcohol consumption was analyzed using a multivariable generalized linear model.RESULTSIn the primary analysis, participants out of the cohort (n = 255) who reported drinking alcohol at baseline and who completed 12 weeks of treatment (n = 151; placebo n = 75, dulaglutide n = 76) were included. The median age was 42 (IQR 33-53) with 61% (n = 92) females. At week 12, participants receiving dulaglutide drank 29% less (relative effect = 0.71, 95% CI 0.52-0.97, P = 0.04) than participants receiving placebo. Changes in alcohol consumption were not correlated with smoking status at week 12.CONCLUSIONThese results provide evidence that dulaglutide reduces alcohol intake in humans and contribute to the growing body of literature promoting the use of GLP-1 agonists in treatment of substance use disorders.TRIAL REGISTRATIONClinicalTrials.gov NCT03204396.FUNDINGSwiss National Foundation, Gottfried Julia Bangerter-Rhyner Foundation, Goldschmidt-Jacobson Foundation, Hemmi Foundation, University of Basel, University Hospital Basel, Swiss Academy of Medical Science. Topics: Adult; Alcohol Drinking; Diabetes Mellitus, Type 2; Double-Blind Method; Female; Glucagon-Like Peptide 1; Humans; Hypoglycemic Agents; Smoking Cessation | 2023 |
The Metabolomic Effects of Tripeptide Gut Hormone Infusion Compared to Roux-en-Y Gastric Bypass and Caloric Restriction.
The gut-derived peptide hormones glucagon-like peptide-1 (GLP-1), oxyntomodulin (OXM), and peptide YY (PYY) are regulators of energy intake and glucose homeostasis and are thought to contribute to the glucose-lowering effects of bariatric surgery.. To establish the metabolomic effects of a combined infusion of GLP-1, OXM, and PYY (tripeptide GOP) in comparison to a placebo infusion, Roux-en-Y gastric bypass (RYGB) surgery, and a very low-calorie diet (VLCD).. Subanalysis of a single-blind, randomized, placebo-controlled study of GOP infusion (ClinicalTrials.gov NCT01945840), including VLCD and RYGB comparator groups.. Twenty-five obese patients with type 2 diabetes or prediabetes were randomly allocated to receive a 4-week subcutaneous infusion of GOP (n = 14) or 0.9% saline control (n = 11). An additional 22 patients followed a VLCD, and 21 underwent RYGB surgery.. Plasma and urine samples collected at baseline and 4 weeks into each intervention were subjected to cross-platform metabolomic analysis, followed by unsupervised and supervised modeling approaches to identify similarities and differences between the effects of each intervention.. Aside from glucose, very few metabolites were affected by GOP, contrasting with major metabolomic changes seen with VLCD and RYGB.. Treatment with GOP provides a powerful glucose-lowering effect but does not replicate the broader metabolomic changes seen with VLCD and RYGB. The contribution of these metabolomic changes to the clinical benefits of RYGB remains to be elucidated. Topics: Adult; Aged; Blood Glucose; Caloric Restriction; Diabetes Mellitus, Type 2; Drug Therapy, Combination; Female; Gastric Bypass; Gastrointestinal Hormones; Glucagon-Like Peptide 1; Humans; Infusions, Subcutaneous; Male; Metabolomics; Middle Aged; Obesity, Morbid; Oxyntomodulin; Peptide YY; Single-Blind Method; Treatment Outcome; Weight Loss; Young Adult | 2022 |
Gastrointestinal Hormones and β-Cell Function After Gastric Bypass and Sleeve Gastrectomy: A Randomized Controlled Trial (Oseberg).
Whether Roux-en-Y gastric bypass (RYGB) and sleeve gastrectomy (SG) differentially affect postprandial gastrointestinal hormones and β-cell function in type 2 diabetes remains unclear.. We aimed to compare gastrointestinal hormones and β-cell function, assessed by an oral glucose tolerance test (OGTT) 5 weeks and 1 year after surgery, hypothesizing higher glucagon-like peptide-1 (GLP-1) levels and greater β-cell response to glucose after RYGB than after SG.. This study was a randomized, triple-blind, single-center trial at a tertiary care center in Norway. The primary outcomes were diabetes remission and IVGTT-derived β-cell function. Participants with obesity and type 2 diabetes were allocated (1:1) to RYGB or SG. We measured gastrointestinal hormone profiles and insulin secretion as β-cell glucose sensitivity (β-GS) derived from 180-minute OGTTs.. Participants were 106 patients (67% women), mean (SD) age 48 (10) years. Diabetes remission rates at 1 year were higher after RYGB than after SG (77% vs 48%; P = 0.002). Incremental area under the curve (iAUC0-180) GLP-1 and β-GS increased more after RYGB than after SG, with 1-year between-group difference 1173 pmol/L*min (95% CI, 569-1776; P = 0.0010) and 0.45 pmol/kg/min/mmol (95% CI, 0.15-0.75; P = 0.0032), respectively. After surgery, fasting and postprandial ghrelin levels were higher and decremental AUC0-180 ghrelin, iAUC0-180 glucose-dependent insulinotropic polypeptide, and iAUC0-60 glucagon were greater after RYGB than after SG. Diabetes remission at 1 year was associated with higher β-GS and higher GLP-1 secretion.. RYGB was associated with greater improvement in β-cell function and higher postprandial GLP-1 levels than SG. Topics: Adult; Blood Glucose; Diabetes Mellitus, Type 2; Female; Follow-Up Studies; Gastrectomy; Gastric Bypass; Glucagon-Like Peptide 1; Glucose Tolerance Test; Humans; Insulin; Insulin-Secreting Cells; Male; Middle Aged; Obesity, Morbid; Postprandial Period; Treatment Outcome | 2022 |
Fortifying a meal with oyster mushroom powder beneficially affects postprandial glucagon-like peptide-1, non-esterified free fatty acids and hunger sensation in adults with impaired glucose tolerance: a double-blind randomized controlled crossover trial.
Impaired glucose tolerance (IGT) is a pathophysiological condition characterized by insulin resistance with known metabolic consequences such as postprandial hyperglycemia and hypertriglyceridemia. We hypothesized that fortifying a meal with mushrooms rich in β-glucans may diminish glucose and triglyceride responses by improving postprandial gastrointestinal hormone release.. In a randomized controlled crossover study, 22 subjects with IGT ingested a meal either enriched with 20 g powder (8.1 g β-glucans) of oven-dried Pleurotus ostreatus (enriched meal, EN) or without enrichment (control meal, CON). Blood was collected before and repeatedly within 4 h after the meal to determine AUC of glucose (primary outcome), insulin, triglycerides, non-esterified free fatty acids (NEFAs), glucagon-like peptide-1 (GLP-1), gastric inhibitory polypeptide (GIP) and ghrelin. Appetite sensations (hunger, satiety, fullness, and desire to eat) were assessed before and after meal consumption by visual analog scales.. Postprandial glucose, insulin, triglycerides, GIP and ghrelin concentrations as well as the corresponding AUCs did not differ between EN and CON. NEFAs-AUC was 14% lower (P = 0.026) and GLP-1-AUC 17% higher (P = 0.001) after EN compared to CON. Appetite ratings did not differ between treatments, except for hunger (AUC 22% lower after EN vs. CON; P = 0.031).. The observed immediate postprandial metabolic changes indicate that an easily manageable fortification of a single meal with powder from dried oyster mushrooms as β-glucan source may improve postprandial metabolism. If the effect is preserved long term, this measure can diminish the risk for further development of overweight/obesity and type 2 diabetes in subjects with IGT.. German Clinical Trial Register on 09/08/2018; trial-ID: DRKS00015244. Topics: Adult; Blood Glucose; Cross-Over Studies; Diabetes Mellitus, Type 2; Fatty Acids, Nonesterified; Glucagon-Like Peptide 1; Glucose Intolerance; Humans; Hunger; Insulin; Pleurotus; Postprandial Period; Powders; Sensation | 2022 |
Effects of Tirzepatide, a Dual GIP and GLP-1 RA, on Lipid and Metabolite Profiles in Subjects With Type 2 Diabetes.
Tirzepatide substantially reduced hemoglobin A1c (HbA1c) and body weight in subjects with type 2 diabetes (T2D) compared with the glucagon-like peptide 1 receptor agonist dulaglutide. Improved glycemic control was associated with lower circulating triglycerides and lipoprotein markers and improved markers of beta-cell function and insulin resistance (IR), effects only partially attributable to weight loss.. Assess plasma metabolome changes mediated by tirzepatide.. Phase 2b trial participants were randomly assigned to receive weekly subcutaneous tirzepatide, dulaglutide, or placebo for 26 weeks. Post hoc exploratory metabolomics and lipidomics analyses were performed.. Post hoc analysis.. 259 subjects with T2D.. Tirzepatide (1, 5, 10, 15 mg), dulaglutide (1.5 mg), or placebo.. Changes in metabolite levels in response to tirzepatide were assessed against baseline levels, dulaglutide, and placebo using multiplicity correction.. At 26 weeks, a higher dose tirzepatide modulated a cluster of metabolites and lipids associated with IR, obesity, and future T2D risk. Branched-chain amino acids, direct catabolic products glutamate, 3-hydroxyisobutyrate, branched-chain ketoacids, and indirect byproducts such as 2-hydroxybutyrate decreased compared to baseline and placebo. Changes were significantly larger with tirzepatide compared with dulaglutide and directly proportional to reductions of HbA1c, homeostatic model assessment 2-IR indices, and proinsulin levels. Proportional to metabolite changes, triglycerides and diglycerides were lowered significantly compared to baseline, dulaglutide, and placebo, with a bias toward shorter and highly saturated species.. Tirzepatide reduces body weight and improves glycemic control and uniquely modulates metabolites associated with T2D risk and metabolic dysregulation in a direction consistent with improved metabolic health. Topics: Adult; Aged; Blood Glucose; Diabetes Mellitus, Type 2; Female; Gastric Inhibitory Polypeptide; Glucagon-Like Peptide 1; Glucagon-Like Peptide-1 Receptor; Glucagon-Like Peptides; Glycated Hemoglobin; Humans; Hypoglycemic Agents; Immunoglobulin Fc Fragments; Injections, Subcutaneous; Male; Metabolomics; Middle Aged; Receptors, Gastrointestinal Hormone; Recombinant Fusion Proteins; Triglycerides; Weight Loss; Young Adult | 2022 |
Duodenal
Although gut dysbiosis is increasingly recognised as a pathophysiological component of metabolic syndrome (MetS), the role and mode of action of specific gut microbes in metabolic health remain elusive. Previously, we identified the commensal butyrogenic. In this randomised double-blind placebo-controlled cross-over study, 12 male subjects with MetS received duodenal infusions of. A single dose of. NTR-NL6630. Topics: Blood Glucose; Blood Glucose Self-Monitoring; Clostridiales; Cross-Over Studies; Diabetes Mellitus, Type 2; Double-Blind Method; Glucagon-Like Peptide 1; Glycemic Control; Humans; Insulin; Insulin Resistance; Male; Metabolic Syndrome; Transcriptome | 2022 |
The glucagon receptor antagonist LY2409021 has no effect on postprandial glucose in type 2 diabetes.
Type 2 diabetes (T2D) pathophysiology includes fasting and postprandial hyperglucagonemia, which has been linked to hyperglycemia via increased endogenous glucose production (EGP). We used a glucagon receptor antagonist (LY2409021) and stable isotope tracer infusions to investigate the consequences of hyperglucagonemia in T2D.. A double-blinded, randomized, placebo-controlled crossover study was conducted.. Ten patients with T2D and ten matched non-diabetic controls underwent two liquid mixed meal tests preceded by single-dose administration of LY2409021 (100 mg) or placebo. Double-tracer technique was used to quantify EGP. Antagonist selectivity toward related incretin receptors was determined in vitro.. Compared to placebo, LY2409021 lowered the fasting plasma glucose (FPG) from 9.1 to 7.1 mmol/L in patients and from 5.6 to 5.0 mmol/L in controls (both P < 0.001) by mechanisms involving reduction of EGP. Postprandial plasma glucose excursions (baseline-subtracted area under the curve) were unaffected by LY2409021 in patients and increased in controls compared to placebo. Glucagon concentrations more than doubled during glucagon receptor antagonism. The antagonist interfered with both glucagon-like peptide 1 and glucose-dependent insulinotropic polypeptide receptors, complicating the interpretation of the postprandial data.. LY2409021 lowered FPG concentrations but did not improve postprandial glucose tolerance after a meal in patients with T2D and controls. The metabolic consequences of postprandial hyperglucagonemia are difficult to evaluate using LY2409021 because of its antagonizing effects on the incretin receptors. Topics: Adult; Aged; Biphenyl Compounds; Blood Glucose; Cross-Over Studies; Diabetes Mellitus, Type 2; Double-Blind Method; Fasting; Female; Gastric Inhibitory Polypeptide; Glucagon; Glucagon-Like Peptide 1; Humans; Male; Middle Aged; Postprandial Period; Receptors, Glucagon | 2022 |
A double-blind, randomized, placebo and positive-controlled study in healthy volunteers to evaluate pharmacokinetic and pharmacodynamic properties of multiple oral doses of cetagliptin.
This study investigated the pharmacokinetics and pharmacodynamics properties, safety and tolerability of cetagliptin.. Forty-eight healthy subjects were enrolled in this study. Three cohorts were investigated in sequential order: 50, 100 and 200 mg cetagliptin. Positive control (sitagliptin 100 mg) was designed as open label. Blood samples were collected and analysed for pharmacokinetic and pharmacodynamic properties. Safety and tolerability were assessed throughout the study.. Following multiple oral doses, cetagliptin was rapidly absorbed and reached peak plasma concentrations after approximately 1.0-1.5 hours. Plasma cetagliptin concentrations increased at a rate greater than dose. Accumulation of cetagliptin was modest, and steady state was generally achieved at day 5. Doses ≥50 mg of cetagliptin administered once daily will result in sustained dipeptidyl peptidase-4 (DPP-4) inhibition (≥80%). The plasma concentration giving 50% of maximum drug effect of DPP-4 inhibition for cetagliptin (5.29 ng/mL) was lower than that of sitagliptin (7.03 ng/mL). Active glucagon-like-1 peptide (GLP-1) concentrations were significantly increased in the cetagliptin groups by 2.3- to 3.1-fold at day 1 and 3.1- to 3.6-fold at steady state compared with that of placebo, and active GLP-1 concentrations were increased with increasing dose. Compared with sitagliptin, doses ≥100 mg once daily of cetagliptin produced postprandial increases in active GLP-1 level and induced to long-lasting glucose-lowering efficacy. Cetagliptin was well tolerated across all doses studied.. Cetagliptin demonstrates the great potential for treatment with type 2 diabetes patients based on the inhibition of DPP-4, the increase in GLP-1 and insulin, the decrease in glucose, and might be more effective in DPP-4 inhibition than sitagliptin. Topics: Area Under Curve; Diabetes Mellitus, Type 2; Dipeptidyl-Peptidase IV Inhibitors; Dose-Response Relationship, Drug; Double-Blind Method; Glucagon-Like Peptide 1; Glucose; Healthy Volunteers; Humans; Hypoglycemic Agents; Sitagliptin Phosphate | 2022 |
Insulin-glucagon-like peptide-1 receptor agonist relay and glucagon-like peptide-1 receptor agonist first regimens in individuals with type 2 diabetes: A randomized, open-label trial study.
Glucagon-like peptide-1 receptor agonists (GLP-1 RA) might be less effective in patients with severe hyperglycemia, because hyperglycemia downregulated the GLP-1 receptor in an animal study. To examine this hypothesis clinically, we compared the glucose-lowering effects of GLP-1 receptor agonist liraglutide with and without prior glycemic control.. In an open-label, parallel trial, participants with poorly controlled type 2 diabetes were recruited and randomized to receive once-daily insulin therapy, degludec (Insulin-GLP-1 RA relay group, mean 16.8 ± 11.4 IU/day), for 12 weeks and then liraglutide for 12 weeks or subcutaneous injections of GLP-1 RA, liraglutide (GLP-1 RA first group, 0.9 mg), for 24 weeks. The primary efficacy end-points consisted of changes in the levels of fasting plasma glucose and glycated hemoglobin (HbA1c).. The median fasting plasma glucose and HbA1c before the study were 210.0 mg/dL and 9.8%, respectively. The levels of fasting plasma glucose and HbA1c significantly decreased in the Insulin-GLP-1 RA relay group (P < 0.001) and GLP-1 RA first group (P < 0.001) by week 24, although no intergroup differences were observed. The reduction of HbA1c in the Insulin-GLP-1 RA relay group tended to be larger than that in the GLP-1 RA first group in the lowest CPR (C-peptide immunoreactivity) quartile (P = 0.072). The adverse events consisted of gastrointestinal problems, followed by hypoglycemia.. The GLP-1 receptor agonist is overall effective without prior glycemic control with insulin in participants with poorly controlled type 2 diabetes. However, in participants with insulinopenic type 2 diabetes, prior glycemic control with insulin might overcome glucose toxicity-induced GLP-1 resistance. Topics: Blood Glucose; Diabetes Mellitus, Type 2; Glucagon-Like Peptide 1; Glucagon-Like Peptide-1 Receptor; Glycated Hemoglobin; Humans; Hyperglycemia; Hypoglycemic Agents; Insulin; Liraglutide | 2022 |
The sodium-glucose cotransporter 2 inhibitor ipragliflozin improves liver function and insulin resistance in Japanese patients with type 2 diabetes.
Sodium-glucose cotransporter 2 inhibitor (SGLT2i) treatment is a therapeutic approach for type 2 diabetes mellitus (T2DM). Some reports have shown that SGLT2i treatment improves insulin resistance; however, few studies have evaluated insulin resistance by the glucose clamp method. Hepatic insulin clearance (HIC) is a new pathophysiological mechanism of T2DM. The effect of SGLT2i treatment on hepatic insulin clearance and insulin resistance is not well known. We investigated the effect of SGLT2i treatment on insulin resistance, insulin secretion, incretin levels, body composition, and hepatic insulin clearance. We conducted a meal tolerance test (MTT) and a hyperinsulinemic-euglycemic clamp test in 9 T2DM patients. Ipragliflozin (50 mg/day) was administered, and the MTT and clamp test were performed after 4 months. We calculated HIC as the postprandial C-peptide AUC-to-insulin AUC ratio. We also measured GLP-1, GIP, and glucagon levels during the MTT. Body weight and HbA1c were decreased, although not significantly, after 4 months of treatment. Postprandial glucose, fasting insulin and postprandial insulin were significantly decreased. Insulin resistance with the glucose clamp was not changed, but the HOMA-IR and insulin sensitivity indices were significantly improved. Incretin and glucagon levels were not changed. Hepatic insulin clearance was significantly increased, but whole-body insulin clearance was not changed. The FIB-4 index and fatty liver index were significantly reduced. The HOMA-beta and insulinogenic indices were not changed, but the C-peptide index was significantly increased. Although the number of patients was small, these results suggested that SGLT2i treatment improved liver function, decreased hepatic insulin resistance, and increased hepatic insulin clearance, despite the small weight reduction. Topics: Biomarkers; Blood Glucose; Diabetes Mellitus, Type 2; Female; Gastric Inhibitory Polypeptide; Glucagon; Glucagon-Like Peptide 1; Glucosides; Humans; Insulin; Insulin Resistance; Japan; Liver; Male; Middle Aged; Sodium-Glucose Transporter 2 Inhibitors; Thiophenes; Time Factors; Treatment Outcome | 2022 |
Effect of a 3-Week Treatment with GLP-1 Receptor Agonists on Vasoactive Hormones in Euvolemic Participants.
Glucagon-like-peptide-1 receptor agonists (GLP-1 RAs) exert cardiovascular benefits by reducing plasma glucose, body weight, and blood pressure. The blood pressure-lowering effect may be mediated by angiotensin II (ANG II) suppression and consecutive natriuresis. However, the role of ANG II and other vasoactive hormones on GLP-1 RA treatment has not been clearly defined.. This work aimed to investigate the effect of a 3-week treatment with the GLP-1 RA dulaglutide on vasoactive hormones, that is, renin, ANG II, aldosterone, mid-regional proatrial natriuretic peptide (MP-proANP), and natriuresis in euvolemic participants.. Randomized, double-blinded, placebo-controlled, crossover trials were conducted at University Hospital Basel, Switzerland. A total of 54 euvolemic participants, including 20 healthy individuals and 34 patients with primary polydipsia, received a subcutaneous injection of dulaglutide (Trulicity) 1.5 mg and placebo (0.9% sodium chloride) once weekly over a 3-week treatment phase.. After a 3-week treatment phase, dulaglutide showed no effect on plasma renin, plasma ANG II, or plasma aldosterone levels in comparison to placebo. Natriuresis remained unchanged or decreased on dulaglutide depending on the measured parameter. Dulaglutide significantly decreased plasma MR-proANP levels (treatment effect: 10.60 pmol/L; 95% CI, -14.70 to -7.90; P < .001) and systolic blood pressure (median: 3 mm Hg; 95% CI, -5 to 0; P = .036), whereas heart rate increased (median: 5 bpm; 95% CI, 3-11; P < .001).. In euvolemic participants, a 3-week treatment of dulaglutide reduced systolic blood pressure independently of plasma renin, ANG II, or aldosterone levels and urinary sodium excretion. The reduction in MR-proANP might be secondary to reduced arterial pulse pressure. Topics: Aldosterone; Angiotensin II; Diabetes Mellitus, Type 2; Double-Blind Method; Glucagon-Like Peptide 1; Glucagon-Like Peptide-1 Receptor; Humans; Hypoglycemic Agents; Immunoglobulin Fc Fragments; Natriuresis; Recombinant Fusion Proteins; Renin | 2022 |
The effects of empagliflozin, dietary energy restriction, or both on appetite-regulatory gut peptides in individuals with type 2 diabetes and overweight or obesity: The SEESAW randomized, double-blind, placebo-controlled trial.
To assess the impact of the sodium-glucose co-transporter-2 (SGLT2) inhibitor empagliflozin (25 mg once-daily), dietary energy restriction, or both combined, on circulating appetite-regulatory peptides in people with type 2 diabetes (T2D) and overweight or obesity.. The mean weight loss in each group at 24 weeks was 0.44, 1.91, 2.22 and 5.74 kg, respectively. The change from baseline to 24 weeks in postprandial total PYY was similar between experimental groups and placebo only (mean difference [95% CI]: -8.6 [-28.6 to 11.4], 13.4 [-6.1 to 33.0] and 1.0 [-18.0 to 19.9] pg/ml in placebo-plus diet, empagliflozin-only and empagliflozin-plus-diet groups, respectively [all P ≥ .18]). Similarly, there was no consistent pattern of difference between groups for postprandial total GLP-1, acylated ghrelin and subjective appetite perceptions.. In people with T2D and overweight or obesity, changes in postprandial appetite-regulatory gut peptides may not underpin the less than predicted weight loss observed with empagliflozin therapy.. NCT02798744, www.. gov; 2015-001594-40, www.EudraCT.ema.europa.eu; ISRCTN82062639, www.ISRCTN.org. Topics: Adult; Aged; Appetite; Benzhydryl Compounds; Diabetes Mellitus, Type 2; Double-Blind Method; Ghrelin; Glucagon-Like Peptide 1; Glucose; Glucosides; Humans; Hypoglycemic Agents; Middle Aged; Obesity; Overweight; Peptide YY; Sodium-Glucose Transporter 2 Inhibitors; Weight Loss | 2022 |
Efficacy and Safety of Once-Weekly Efpeglenatide Monotherapy Versus Placebo in Type 2 Diabetes: The AMPLITUDE-M Randomized Controlled Trial.
To assess the efficacy and safety of the glucagon-like peptide 1 receptor agonist (GLP-1 RA) efpeglenatide versus placebo in patients with type 2 diabetes inadequately controlled with diet and exercise alone.. AMPLITUDE-M was a phase 3, double-blind, placebo-controlled, multicenter trial that randomized adults with type 2 diabetes suboptimally controlled with diet and exercise alone to once-weekly efpeglenatide (2, 4, or 6 mg) or placebo for up to 56 weeks. The primary objective was to demonstrate the superiority of efpeglenatide versus placebo for HbA1c reduction at week 30. Secondary objectives included changes in other measures of glycemic control and body weight at weeks 30 and 56.. At week 30, HbA1c was reduced from a baseline of 8.1% (65 mmol/mol) to 6.9% (52 mmol/mol), 6.6% (49 mmol/mol), and 6.4% (47 mmol/mol) with efpeglenatide 2, 4, and 6 mg, respectively. Least squares mean HbA1c reductions from baseline were statistically superior for each efpeglenatide dose versus placebo (2 mg, -0.5% [95% CI -0.9, -0.2; P = 0.0054]; 4 mg, -0.8% [-1.2, -0.5; P < 0.0001]; 6 mg, -1.0% [-1.4, -0.7; P < 0.0001]). A greater proportion of efpeglenatide-treated patients (all doses) achieved HbA1c <7% (53 mmol/mol) versus placebo by week 30 (P < 0.0001 for all), and significant reductions in body weight and fasting plasma glucose were also observed for efpeglenatide (4 and 6 mg doses) versus placebo at week 30 (P < 0.05 for all). Consistent with the GLP-1 RA class, gastrointestinal adverse events were most commonly reported; these were generally transient and mild/moderate in severity. Few patients reported hypoglycemia.. As monotherapy in patients with type 2 diabetes, once-weekly efpeglenatide significantly improved glycemic control and body weight with a safety and tolerability profile similar to that of other GLP-1 RAs. Topics: Adult; Blood Glucose; Body Weight; Diabetes Mellitus, Type 2; Double-Blind Method; Drug Therapy, Combination; Glucagon-Like Peptide 1; Glycated Hemoglobin; Humans; Hypoglycemic Agents; Metformin; Proline; Treatment Outcome | 2022 |
Acute effects on glucose tolerance by neprilysin inhibition in patients with type 2 diabetes.
Sacubitril/valsartan is a neprilysin-inhibitor/angiotensin II receptor blocker used for the treatment of heart failure. Recently, a post-hoc analysis of a 3-year randomized controlled trial showed improved glycaemic control with sacubitril/valsartan in patients with heart failure and type 2 diabetes. We previously reported that sacubitril/valsartan combined with a dipeptidyl peptidase-4 inhibitor increases active glucagon-like peptide-1 (GLP-1) in healthy individuals. We now hypothesized that administration of sacubitril/valsartan with or without a dipeptidyl peptidase-4 inhibitor would lower postprandial glucose concentrations (primary outcome) in patients with type 2 diabetes via increased active GLP-1.. We performed a crossover trial in 12 patients with obesity and type 2 diabetes. A mixed meal was ingested following five respective interventions: (a) a single dose of sacubitril/valsartan; (b) sitagliptin; (c) sacubitril/valsartan + sitagliptin; (d) control (no treatment); and (e) valsartan alone. Glucose, gut and pancreatic hormone responses were measured.. Postprandial plasma glucose increased by 57% (incremental area under the curve 0-240 min) (p = .0003) and increased peak plasma glucose by 1.7 mM (95% CI: 0.6-2.9) (p = .003) after sacubitril/valsartan compared with control, whereas postprandial glucose levels did not change significantly after sacubitril/valsartan + sitagliptin. Glucagon, GLP-1 and C-peptide concentrations increased after sacubitril/valsartan, but insulin and glucose-dependent insulinotropic polypeptide did not change.. The glucose-lowering effects of long-term sacubitril/valsartan treatment reported in patients with heart failure and type 2 diabetes may not depend on changes in entero-pancreatic hormones. Neprilysin inhibition results in hyperglucagonaemia and this may explain the worsen glucose tolerance observed in this study.. gov (NCT03893526). Topics: Aged; Aminobutyrates; Angiotensin Receptor Antagonists; Biphenyl Compounds; Blood Glucose; Diabetes Mellitus, Type 2; Dipeptidyl-Peptidase IV Inhibitors; Drug Combinations; Glucagon-Like Peptide 1; Glucose Tolerance Test; Heart Failure; Humans; Hypoglycemic Agents; Male; Middle Aged; Neprilysin; Sitagliptin Phosphate; Tetrazoles; Valsartan | 2022 |
A phase 1b randomised controlled trial of a glucagon-like peptide-1 and glucagon receptor dual agonist IBI362 (LY3305677) in Chinese patients with type 2 diabetes.
The success of glucagon-like peptide-1 (GLP-1) receptor agonists to treat type 2 diabetes (T2D) and obesity has sparked considerable efforts to develop next-generation co-agonists that are more effective. We conducted a randomised, placebo-controlled phase 1b study (ClinicalTrials.gov: NCT04466904) to evaluate the safety and efficacy of IBI362 (LY3305677), a GLP-1 and glucagon receptor dual agonist, in Chinese patients with T2D. A total of 43 patients with T2D were enrolled in three cohorts in nine study centres in China and randomised in each cohort to receive once-weekly IBI362 (3.0 mg, 4.5 mg or 6.0 mg), placebo or open-label dulaglutide (1.5 mg) subcutaneously for 12 weeks. Forty-two patients received the study treatment and were included in the analysis, with eight receiving IBI362, four receiving placebo and two receiving dulaglutide in each cohort. The patients, investigators and study site personnel involved in treating and assessing patients in each cohort were masked to IBI362 and placebo allocation. Primary outcomes were safety and tolerability of IBI362. Secondary outcomes included the change in glycated haemoglobin A Topics: Blood Glucose; Diabetes Mellitus, Type 2; Glucagon; Glucagon-Like Peptide 1; Glucagon-Like Peptide-1 Receptor; Glycated Hemoglobin; Humans; Hypoglycemic Agents; Peptides; Receptors, Glucagon; Recombinant Fusion Proteins | 2022 |
Endogenous Glucose-Dependent Insulinotropic Polypeptide Contributes to Sitagliptin-Mediated Improvement in β-Cell Function in Patients With Type 2 Diabetes.
Dipeptidyl peptidase 4 (DPP-4) degrades the incretin hormones glucagon-like peptide 1 and glucose-dependent insulinotropic polypeptide (GIP). DPP-4 inhibitors improve glycemic control in type 2 diabetes, but the importance of protecting GIP from degradation for their clinical effects is unknown. We included 12 patients with type 2 diabetes (mean ± SD BMI 27 ± 2.6 kg/m2, HbA1c 7.1 ± 1.4% [54 ± 15 mmol/mol]) in this double-blind, placebo-controlled, crossover study to investigate the contribution of endogenous GIP to the effects of the DPP-4 inhibitor sitagliptin. Participants underwent two randomized, 13-day treatment courses of sitagliptin (100 mg/day) and placebo, respectively. At the end of each treatment period, we performed two mixed-meal tests with infusion of the GIP receptor antagonist GIP(3-30)NH2 (1,200 pmol/kg/min) or saline placebo. Sitagliptin lowered mean fasting plasma glucose by 1.1 mmol/L compared with placebo treatment. During placebo treatment, postprandial glucose excursions were increased during GIP(3-30)NH2 compared with saline (difference in area under the curve ± SEM 7.3 ± 2.8%) but were unchanged during sitagliptin treatment. Endogenous GIP improved β-cell function by 37 ± 12% during DPP-4 inhibition by sitagliptin. This was determined by the insulin secretion rate/plasma glucose ratio. We calculated an estimate of the absolute sitagliptin-mediated impact of GIP on β-cell function as the insulinogenic index during sitagliptin treatment plus saline infusion minus the insulinogenic index during sitagliptin plus GIP(3-30)NH2. This estimate was expressed relative to the maximal potential contribution of GIP to the effect of sitagliptin (100%), defined as the difference between the full sitagliptin treatment effect, including actions mediated by GIP (sitagliptin + saline), and the physiological response minus any contribution by GIP [placebo treatment + GIP(3-30)NH2]. We demonstrate insulinotropic and glucose-lowering effects of endogenous GIP in patients with type 2 diabetes and that endogenous GIP contributes to the improved β-cell function observed during DPP-4 inhibition. Topics: Blood Glucose; Cross-Over Studies; Diabetes Mellitus, Type 2; Dipeptidyl Peptidase 4; Dipeptidyl-Peptidase IV Inhibitors; Double-Blind Method; Gastric Inhibitory Polypeptide; Glucagon-Like Peptide 1; Glycated Hemoglobin; Humans; Incretins; Receptors, Gastrointestinal Hormone; Sitagliptin Phosphate | 2022 |
Metabolic, Intestinal, and Cardiovascular Effects of Sotagliflozin Compared With Empagliflozin in Patients With Type 2 Diabetes: A Randomized, Double-Blind Study.
Inhibiting sodium-glucose cotransporters (SGLTs) improves glycemic and cardiovascular outcomes in patients with type 2 diabetes (T2D). We investigated the differential impact of selective SGLT2 inhibition and dual inhibition of SGLT1 and SGLT2 on multiple parameters.. Using a double-blind, parallel-group design, we randomized 40 patients with T2D and hypertension to receive the dual SGLT1 and SGLT2 inhibitor sotagliflozin 400 mg or the selective SGLT2 inhibitor empagliflozin 25 mg, with preexisting antihypertensive treatment, for 8 weeks. In an in-house testing site, mixed-meal tolerance tests (MMTTs) and other laboratory and clinical evaluations were used to study metabolic, intestinal, cardiovascular, and urinary parameters over 24 h.. Changes from baseline in glycemic and blood pressure control; intestinal, urine, and metabolic parameters; and cardiovascular biomarkers were generally similar with sotagliflozin and empagliflozin. During the breakfast MMTT, sotagliflozin significantly reduced incremental area under the curve (AUC) values for postprandial glucose, insulin, and glucose-dependent insulinotropic polypeptide (GIP) and significantly increased incremental AUCs for postprandial glucagon-like peptide 1 (GLP-1) relative to empagliflozin, consistent with sotagliflozin-mediated inhibition of intestinal SGLT1. These changes waned during lunch and dinner MMTTs. Both treatments significantly lowered GIP incremental AUCs relative to baseline over the 14 h MMTT interval; the most vigorous effect was seen with sotagliflozin soon after start of the first meal of the day. No serious or severe adverse events were observed.. Changes from baseline in glycemic and blood pressure control, cardiovascular biomarkers, and other parameters were comparable between sotagliflozin and empagliflozin. However, sotagliflozin but not empagliflozin inhibited intestinal SGLT1 after breakfast as shown by larger changes in postprandial glucose, insulin, GIP, and GLP-1 AUCs, particularly after breakfast. Additional study is warranted to assess the clinical relevance of transient SGLT1 inhibition and differences in incretin responses (NCT03462069). Topics: Blood Glucose; Diabetes Mellitus, Type 2; Double-Blind Method; Gastric Inhibitory Polypeptide; Glucagon-Like Peptide 1; Glycosides; Humans; Hypoglycemic Agents; Insulin; Sodium-Glucose Transporter 2; Sodium-Glucose Transporter 2 Inhibitors | 2022 |
Comparison of the effects of exenatide and insulin glargine on right and left ventricular myocardial deformation as shown by 2D-speckle-tracking echocardiograms.
Exenatide is a glucagon-like peptide-1 (GLP-1) analogs. The effects of GLP-1 analogs on myocardial function are controversial.. The purpose of this study is to compare the effects of exenatide and insulin glargine on subclinical right and left ventricular dysfunction.. In this study, 27 patients with type 2 diabetes were randomized into exenatide and insulin glargine treatment groups. The patients were monitored for six months by conventional echocardiography (ECHO) and 2D-speckle-tracking echocardiography (2D-STE) to evaluate right and left ventricular functions.. ECHO parameters did not change significantly pre- and post-treatment, except for the tricuspid annular plane systolic excursion (TAPSE) values. Post-treatment TAPSE values significantly increased in both groups compared to pre-treatment values. In the insulin group, values for 2D-STE parameters of the left ventricular global longitudinal strain (LVGLS) based on apical long-axis (ALA) images increased significantly (p: 0.047) compared to pre-treatment values; however, apical 4-chamber (A4C), apical 2-chamber (A2C), LVGLS, and right ventricular global longitudinal strain (RVGLS) values did not change. In the exenatide group, LVGLS based on A4C values improved (p: 0.048), while ALA, A2C, and LVGLS values did not change. Moreover, the RVGLS values improved significantly after exenatide treatment (p: 0.002). Based on 2D-STE parameters the two treatments did not differ statistically in either pre- or post-treatment periods.. Glp-1 treatment can improve left ventricular regional and right ventricular global subclinical dysfunction. Therefore, early GLP-1 treatment may be recommended in diabetic patients with a high risk of cardiac dysfunction. Topics: Diabetes Mellitus, Type 2; Exenatide; Glucagon-Like Peptide 1; Humans; Insulin Glargine; Ventricular Dysfunction, Right | 2022 |
Metagenomic analysis reveals crosstalk between gut microbiota and glucose-lowering drugs targeting the gastrointestinal tract in Chinese patients with type 2 diabetes: a 6 month, two-arm randomised trial.
The use of oral glucose-lowering drugs, particularly those designed to target the gut ecosystem, is often observed in association with altered gut microbial composition or functional capacity in individuals with type 2 diabetes. The gut microbiota, in turn, plays crucial roles in the modulation of drug efficacy. We aimed to assess the impacts of acarbose and vildagliptin on human gut microbiota and the relationships between pre-treatment gut microbiota and therapeutic responses.. This was a randomised, open-labelled, two-arm trial in treatment-naive type 2 diabetes patients conducted in Beijing between December 2016 and December 2017. One hundred participants with overweight/obesity and newly diagnosed type 2 diabetes were recruited from the Pinggu Hospital and randomly assigned to the acarbose (n=50) or vildagliptin (n=50) group using sealed envelopes. The treatment period was 6 months. Blood, faecal samples and visceral fat data from computed tomography images were collected before and after treatments to measure therapeutic outcomes and gut microbiota. Metagenomic datasets from a previous type 2 diabetes cohort receiving acarbose or glipizide for 3 months were downloaded and processed. Statistical analyses were applied to identify the treatment-related changes in clinical variables, gut microbiota and associations.. This study reveals common microbial responses in type 2 diabetes patients treated with two glucose-lowering drugs targeting the gut differently and acceptable performance of baseline gut microbiota in classifying individuals with different GLP-1 responses to vildagliptin. Our findings highlight bidirectional interactions between gut microbiota and glucose-lowering drugs.. ClinicalTrials.gov NCT02999841 FUNDING: National Key Research and Development Project: 2016YFC1304901. Topics: Acarbose; Blood Glucose; China; Diabetes Mellitus, Type 2; Ecosystem; Gastrointestinal Microbiome; Gastrointestinal Tract; Glipizide; Glucagon-Like Peptide 1; Glucose; Humans; Hypoglycemic Agents; Research; Vildagliptin | 2022 |
[Focus on tirzepatide, a dual unimolecular GIP-GLP-1 receptor agonist in type 2 diabetes].
Tirzepatide is a unimolecular dual agonist of both glucose-dependent insulinotropic polypeptide (GIP) and glucagon-like peptide-1 (GLP-1) receptors, which is developed as once-weekly injection for the treatment of type 2 diabetes. Because of the complementarity of action of the two incretins, tirzepatide showed, in a dose-dependent manner (5, 10 and 15 mg), a better efficacy (greater reduction in HbA1c and body weight) compared with placebo, basal insulin and two GLP-1 analogues (dulaglutide and semaglutide) in the SURPASS program. Its cardiovascular protection (versus dulaglutide) is currently tested in SURPASS-CVOT. Finally, studies for the treatment of obesity and metabolic associated fatty liver disease are also ongoing. Gastrointestinal tolerance of tirzepatide appears comparable to that of GLP-1 analogues, except more diarrhoea.. Le tirzépatide est un agoniste unimoléculaire double des récepteurs du polypeptide insulinotrope dépendant du glucose (GIP) et du Glucagon-Like Peptide-1 (GLP-1) développé, en injection hebdomadaire, pour le traitement du diabète de type 2. De par la complémentarité des 2 incrétines, il a montré, de façon dose-dépendante (5, 10 et 15 mg), une efficacité supérieure (plus forte réduction du taux d’HbA1c (hémoglobine glyquée) et du poids corporel) par rapport au placebo, à l’insuline basale et à 2 analogues du GLP-1 (dulaglutide et sémaglutide) dans le programme SURPASS. Sa protection cardiovasculaire (versus le dulaglutide) est actuellement testée dans SURPASS-CVOT. Enfin, des études sont en cours dans l’obésité et la stéatopathie hépatique. La tolérance digestive du tirzépatide est comparable à celle des analogues du GLP-1, hormis davantage de diarrhée. Topics: Blood Glucose; Diabetes Mellitus, Type 2; Gastric Inhibitory Polypeptide; Glucagon-Like Peptide 1; Glucagon-Like Peptide-1 Receptor; Humans; Hypoglycemic Agents | 2022 |
Gut microbiota is correlated with gastrointestinal adverse events of metformin in patients with type 2 diabetes.
Gastrointestinal discomfort is the most common adverse event in metformin treatment for type 2 diabetes. The mechanism of action of metformin is associated with gut microbiota. However, the gut microbial community structure related to metformin-induced gastrointestinal adverse events remains unclear. This study aimed to investigate it.. 50 patients with newly diagnosed diabetes were treated with metformin 1500mg/d for 12 weeks. The patients were divided into two groups according to whether gastrointestinal adverse events occurred (group B) or did not occur (group A) after treatment. The fecal bacterial communities and short-chain fatty acids (SCFAs) were sequenced and compared. 70 diabetes mice were randomly divided into 8 groups and treated with metformin (Met), clindamycin (Clin) and/or SCFA, which were the Met+/Clin+, Met+/Clin-, Met-/Clin+, Met-/Clin-, Met+/SCFA+, Met+/SCFA-, Met-/SCFA+ and Met-/SCFA- group. After 4 weeks of metformin treatment, blood glucose, food intake, fecal SCFAs, gut microbiota and gut hormones were measured.. Our data suggest that metformin promotes the secretion of intestinal hormones such as GLP-1 by increasing the abundance of SCFA-producing bacteria, which not only plays an anti-diabetic role, but also may causes gastrointestinal adverse events. Topics: Animals; Diabetes Mellitus, Type 2; Gastrointestinal Hormones; Gastrointestinal Microbiome; Glucagon-Like Peptide 1; Humans; Metformin; Mice; Propionates | 2022 |
Ceramides and phospholipids are downregulated with liraglutide treatment: results from the LiraFlame randomized controlled trial.
Treatment with glucagon-like peptide-1 receptor agonists (GLP-1 RAs) can reduce risk of cardiovascular disease (CVD) in persons living with type 2 diabetes, however the mechanisms explaining this cardiovascular benefit are still debated. We investigated changes in the plasma lipidome following treatment with the GLP-1 RA liraglutide.. In a double-blind placebo-controlled trial, we randomized 102 persons with type 2 diabetes to liraglutide or placebo for 26 weeks. Fasting blood plasma was collected at baseline and at end-of-treatment. The lipidome was measured using liquid-chromatography-coupled mass-spectrometry as a secondary end point in the study. Treatment response of each lipid was tested with lipid-specific linear mixed-effect models comparing liraglutide with placebo. Bonferroni p<7.1e-03 was employed. The independence of the findings from clinical covariates was evaluated with adjustment for body mass index, HbA. In total, 260 lipids were identified covering 11 lipid families. We observed significant decreases following liraglutide treatment compared with placebo in 21 lipids (p<7.1e-03) from the following lipid families: ceramides, hexocyl-ceramides, phosphatidylcholines, phosphatidylethanolamines and triglycerides. We confirmed these findings in adjusted models (p≤0.01). In the liraglutide-treated group, the individual lipids were reduced in the range of 14%-61% from baseline level, compared with 19% decrease to 27% increase from baseline level in the placebo group.. Compared with placebo, liraglutide treatment led to a significant downregulation in ceramides, phospholipids and triglycerides, which all are linked to higher risk of CVD. These findings were independent of relevant clinical covariates. Our findings are hypothesis generating and shed light on the biological mechanisms underlying the cardiovascular benefits observed with GLP-1 RAs in outcome studies, and further strengthen the evidence base for recommending GLP-1 RAs to prevent CVD in type 2 diabetes.. NCT03449654. Topics: Ceramides; Diabetes Mellitus, Type 2; Glucagon-Like Peptide 1; Humans; Liraglutide; Phospholipids | 2021 |
Efficacy of a glucagon-like peptide-1 agonist and restrictive versus liberal oxygen supply in patients undergoing coronary artery bypass grafting or aortic valve replacement: study protocol for a 2-by-2 factorial designed, randomised clinical trial.
Coronary artery bypass grafting (CABG) and/or aortic valve replacement (AVR) are associated with risk of death, as well as brain, heart and kidney injury. Glucagon-like peptide-1 (GLP-1) analogues are approved for treatment of type 2 diabetes, and GLP-1 analogues have been suggested to have potential organ-protective and anti-inflammatory effects. During cardiopulmonary bypass (CPB), consensus on the optimal fraction of oxygen is lacking. The objective of this study is to determine the efficacy of the GLP-1-analogue exenatide versus placebo and restrictive oxygenation (50% fractional inspired oxygen, FiO2) versus liberal oxygenation (100% FiO2) in patients undergoing open heart surgery.. A randomised, placebo-controlled, double blind (for the exenatide intervention)/single blind (for the oxygenation strategy), 2×2 factorial designed single-centre trial on adult patients undergoing elective or subacute CABG and/or surgical AVR. Patients will be randomised in a 1:1 and 1:1 ratio to a 6-hour and 15 min infusion of 17.4 µg of exenatide or placebo during CPB and to a FiO2 of 50% or 100% during and after weaning from CPB. Patients will be followed until 12 months after inclusion of the last participant. The primary composite endpoint consists of time to first event of death, renal failure requiring renal replacement therapy, hospitalisation for stroke or heart failure. In addition, the trial will include predefined sub-studies applying more advanced measures of cardiac- and pulmonary dysfunction, renal dysfunction and cerebral dysfunction. The trial is event driven and aims at 323 primary endpoints with a projected inclusion of 1400 patients.. Eligible patients will provide informed, written consent prior to randomisation. The trial is approved by the local ethics committee and is conducted in accordance with Danish legislation and the Declaration of Helsinki. The results will be presented in peer-reviewed journals.. NCT02673931. Topics: Adult; Aortic Valve; Coronary Artery Bypass; Diabetes Mellitus, Type 2; Double-Blind Method; Glucagon-Like Peptide 1; Humans; Oxygen; Randomized Controlled Trials as Topic; Single-Blind Method; Treatment Outcome | 2021 |
Safety, tolerability, pharmacodynamics, and pharmacokinetics of CJC-1134-PC in healthy Chinese subjects and type-2 diabetic subjects.
Glucagon-like peptide-1 (GLP-1) mimetics are widely used for treating type 2 diabetes (T2D) with pleiotropic effects on heart and kidneys. The safety/tolerability and pharmacokinetics/pharmacodynamics ((PK/PD) of CJC-1134-PC (a long-acting GLP-1) were investigated in Chinese.. Two randomized, double-blind, placebo-controlled phase I studies were conducted. Study A: 30 healthy subjects received (subcutaneously injected) a single dose (2 mg) or titrate doses (2 + 3 and 2 + 3 + 4 mg at weekly intervals) of CJC-1134-PC. Study B: 49 T2D subjects received 10 weekly doses (1, 2, 3, and 4 mg).. CJC-1134-PC was well tolerated with gastrointestinal (GI) side effects. Higher doses increased the adverse events risk. CJC-1134-PC was steadily absorbed, with maximum plasma concentrations(C. The safety and PK/PD profiles of weekly CJC-1134-PC doses support Phase II studies with guidance on optimal-dose selection. Clinical trial registration: ChiCTR-IPC-15007190. Topics: China; Diabetes Mellitus, Type 2; Dose-Response Relationship, Drug; Double-Blind Method; Glucagon-Like Peptide 1; Healthy Volunteers; Humans | 2021 |
The Mediterranean diet increases glucagon-like peptide 1 and oxyntomodulin compared with a vegetarian diet in patients with type 2 diabetes: A randomized controlled cross-over trial.
To compare a Mediterranean diet (MED) with a high-fibre vegetarian diet (HFV) in terms of hunger-satiety perception through post-prandial assessment of appetite-related hormones glucagon-like peptide 1 (GLP-1) and oxyntomodulin, as well as self-rated visual analogue scale (VAS) quantification, in overweight/obese subjects with type 2 diabetes (T2D).. Twelve T2D subjects (Male to female ratio = 7:5), mean age 63 ± 8.5 years, were enrolled in a randomized, controlled, crossover study. Participants consumed an MED meal as well as an isocaloric meal rich in complex carbohydrate as well as an isocaloric MED meal in two different visits with a 1-week washout period between the two visits. Appetite ratings, glucose/insulin, and gastrointestinal hormone concentrations were measured at fasting and every 30' until 210' following meal consumption.. GLP-1 and oxyntomodulin levels were significantly higher following MED meal compared with HFV meals (210' area under the curve, p < 0.022 and p < 0.023, respectively). Both MED and HFV meal resulted in a biphasic pattern of GLP-1 and oxyntomodulin, although MED meal was related to a delayed, significantly higher second GLP-1 peak at 150' compared with that of HFV meal (p < 0.05). MED meal was related to lower glucose profile compared with HFV meal (p < 0.039), whereas we did not observe significant changes in terms of self-reported VAS scores and insulin trend.. In T2D overweight/obese subjects, an MED meal is more effective than a HFV meal in terms of post-prandial plasma glucose homoeostasis and GLP-1 and oxyntomodulin release. These changes were not confirmed by VAS appetite self-assessment over a 210' period. Topics: Aged; Blood Glucose; Cross-Over Studies; Diabetes Mellitus, Type 2; Diet, Mediterranean; Diet, Vegetarian; Female; Glucagon-Like Peptide 1; Glucose; Humans; Insulin; Male; Middle Aged; Obesity; Overweight; Oxyntomodulin; Postprandial Period | 2021 |
Acute effects of delayed-release hydrolyzed pine nut oil on glucose tolerance, incretins, ghrelin and appetite in healthy humans.
Pinolenic acid, a major component (~20%) of pine nut oil, is a dual agonist of the free fatty acid receptors, FFA1 and FFA4, which may regulate release of incretins and ghrelin from the gut. Here, we investigated the acute effects of hydrolyzed pine nut oil (PNO-FFA), delivered to the small intestine by delayed-release capsules, on glucose tolerance, insulin, incretin and ghrelin secretion, and appetite.. In two cross-over studies, we evaluated 3 g unhydrolyzed pine nut oil (PNO-TG) or 3 g PNO-FFA versus no oil in eight healthy, non-obese subjects (study 1), and 3 g PNO-FFA or 6 g PNO-FFA versus no oil in ten healthy, overweight/obese subjects (study 2) in both studies given in delayed-release capsules 30 min prior to a 4-h-oral glucose tolerance test (OGTT). Outcomes were circulating levels of glucose, insulin, GLP-1, GIP, ghrelin, appetite and gastrointestinal tolerability during OGTT.. Both 3 g PNO-FFA in study 1 and 6 g PNO-FFA in study 2 markedly increased GLP-1 levels (p < 0.001) and attenuated ghrelin levels (p < 0.001) during the last 2 h of the OGTT compared with no oil. In study 2, these effects of PNO-FFA were accompanied by an increased satiety and fullness (p < 0.03), and decreased prospective food consumption (p < 0.05). PNO-FFA caused only small reductions in glucose and insulin levels during the first 2 h of the OGTT.. Our results provide evidence that PNO-FFA delivered to the small intestine by delayed-release capsules may reduce appetite by augmenting GLP-1 release and attenuating ghrelin secretion in the late postprandial state.. NCT03062592 and NCT03305367. Topics: Adult; Aged; Appetite; Blood Glucose; C-Peptide; Cross-Over Studies; Delayed-Action Preparations; Diabetes Mellitus, Type 2; Female; Gastric Inhibitory Polypeptide; Ghrelin; Glucagon-Like Peptide 1; Glucose Tolerance Test; Humans; Hydrolysis; Incretins; Insulin; Intestine, Small; Linolenic Acids; Male; Middle Aged; Pinus; Plant Oils; Seeds | 2021 |
The Effect of Standard Versus Longer Intestinal Bypass on GLP-1 Regulation and Glucose Metabolism in Patients With Type 2 Diabetes Undergoing Roux-en-Y Gastric Bypass: The Long-Limb Study.
Roux-en-Y gastric bypass (RYGB) characteristically enhances postprandial levels of glucagon-like peptide 1 (GLP-1), a mechanism that contributes to its profound glucose-lowering effects. This enhancement is thought to be triggered by bypass of food to the distal small intestine with higher densities of neuroendocrine L-cells. We hypothesized that if this is the predominant mechanism behind the enhanced secretion of GLP-1, a longer intestinal bypass would potentiate the postprandial peak in GLP-1, translating into higher insulin secretion and, thus, additional improvements in glucose tolerance. To investigate this, we conducted a mechanistic study comparing two variants of RYGB that differ in the length of intestinal bypass.. A total of 53 patients with type 2 diabetes (T2D) and obesity were randomized to either standard limb RYGB (50-cm biliopancreatic limb) or long limb RYGB (150-cm biliopancreatic limb). They underwent measurements of GLP-1 and insulin secretion following a mixed meal and insulin sensitivity using euglycemic hyperinsulinemic clamps at baseline and 2 weeks and at 20% weight loss after surgery.. Both groups exhibited enhancement in postprandial GLP-1 secretion and improvements in glycemia compared with baseline. There were no significant differences in postprandial peak concentrations of GLP-1, time to peak, insulin secretion, and insulin sensitivity.. The findings of this study demonstrate that lengthening of the intestinal bypass in RYGB does not affect GLP-1 secretion. Thus, the characteristic enhancement of GLP-1 response after RYGB might not depend on delivery of nutrients to more distal intestinal segments. Topics: Blood Glucose; Diabetes Mellitus, Type 2; Gastric Bypass; Glucagon-Like Peptide 1; Humans; Insulin; Jejunoileal Bypass | 2021 |
Safety, Pharmacokinetics, and Pharmacodynamics of a Dipeptidyl Peptidase-4 Inhibitor: A Randomized, Double-Blinded, Placebo-Controlled Daily Administration of Fotagliptin Benzoate for 14 Days for Type 2 Diabetes Mellitus.
This study investigated the pharmacokinetics, pharmacodynamics, and safety of fotagliptin benzoate (fotagliptin), a dipeptidyl peptidase-4 (DPP-4) inhibitor, in Chinese patients with type 2 diabetes mellitus (T2DM). In a randomized, double-blinded, placebo-controlled study, 10 and 4 patients with T2DM were randomized and received, respectively, once-daily oral fotagliptin (24 mg) or placebo, for 14 days. The pharmacokinetics and pharmacodynamics were assessed throughout the study, including monitoring DPP-4, glucagon-like peptide-1 (GLP-1), glycosylated hemoglobin, and fasting blood glucose. Fotagliptin was rapidly absorbed, and the median time to maximum concentration value was ∼1.5 hours. Plasma fotagliptin levels were stable after 14 days of once-daily dosage. The accumulation ratios for the area under the plasma concentration-time curve of fotagliptin, M1, and M2-1, were 1.19 ± 0.10, 1.59 ± 0.27, and 1.39 ± 0.26, respectively. The durations for DPP-4 inhibition >80% in the fotagliptin group on days 1 and 14 were 23.5 and 24.0 hours, respectively. The concentrations of GLP-1 were higher on days 1 and 14 than at the baseline. No serious complications occurred. Fotagliptin showed favorable pharmacokinetics and pharmacodynamics and was well tolerated. Treatment with fotagliptin can achieve high DPP-4 inhibition and increase plasma GLP-1. A once-per-day dosing regimen may be recommended as clinically efficacious. Topics: Administration, Oral; Adult; Area Under Curve; Blood Glucose; Diabetes Mellitus, Type 2; Dipeptidyl-Peptidase IV Inhibitors; Double-Blind Method; Female; Glucagon-Like Peptide 1; Glycated Hemoglobin; Humans; Male; Middle Aged; Piperidines; Triazines | 2021 |
The role of GLP-1 in the postprandial effects of acarbose in type 2 diabetes.
The alpha-glucosidase inhibitor acarbose is believed to reduce plasma glucose by delaying hydrolysis of carbohydrates. Acarbose-induced transfer of carbohydrates to the distal parts of the intestine increases circulating glucagon-like peptide 1 (GLP-1). Using the GLP-1 receptor antagonist exendin(9-39)NH2, we investigated the effect of acarbose-induced GLP-1 secretion on postprandial glucose metabolism in patients with type 2 diabetes.. In a double-blinded, placebo-controlled, randomized, crossover study, 15 participants with metformin-treated type 2 diabetes (age: 57-85 years, HbA1c: 40-74 mmol/mol) were subjected to two 14-day treatment periods with acarbose or placebo, respectively, separated by a 6-week wash-out period. At the end of each period, two randomized 4-h liquid mixed meal tests with concomitant infusion of exendin(9-39)NH2 and saline, respectively, were performed.. Compared to placebo, acarbose increased postprandial GLP-1 concentrations and decreased postprandial glucose. We observed no absolute difference in the exendin(9-39)NH2-induced increase in postprandial glucose excursions between placebo and acarbose periods, but relatively, postprandial glucose was increased by 119 ± 116% (mean ± s.d.) during exendin(9-39)NH2 infusion in the acarbose period vs a 39 ± 27% increase during the placebo period (P = 0.0163).. We confirm that acarbose treatment stimulates postprandial GLP-1 secretion in patients with type 2 diabetes. Using exendin(9-39)NH2, we did not see an impact of acarbose-induced GLP-1 secretion on absolute measures of postprandial glucose tolerance, but relatively, the effect of exendin(9-39)NH2 was most pronounced during acarbose treatment. Topics: Acarbose; Aged; Aged, 80 and over; Blood Glucose; Cross-Over Studies; Denmark; Diabetes Mellitus, Type 2; Double-Blind Method; Female; Gastric Emptying; Glucagon-Like Peptide 1; Humans; Insulin Resistance; Insulin-Secreting Cells; Male; Metformin; Middle Aged; Placebos; Postprandial Period | 2021 |
Efficacy and safety of glucagon-like peptide-1/glucagon receptor co-agonist JNJ-64565111 in individuals with type 2 diabetes mellitus and obesity: A randomized dose-ranging study.
Weight loss has been shown to improve metabolic parameters and cardiovascular risk in people with type 2 diabetes mellitus (T2DM). This phase 2 study evaluated the safety and efficacy of JNJ-64565111, a dual agonist of GLP-1 and glucagon receptors, in individuals with T2DM and class II/III obesity. In this randomized, double-blind study, participants with T2DM (HbA1c 6.5%-9.5%), body mass index of 35 to 50 kg/m Topics: Blood Glucose; Diabetes Mellitus, Type 2; Double-Blind Method; Glucagon-Like Peptide 1; Glucagon-Like Peptide-1 Receptor; Glycated Hemoglobin; Humans; Hypoglycemic Agents; Obesity; Receptors, Glucagon | 2021 |
Efficacy and safety of glucagon-like peptide-1/glucagon receptor co-agonist JNJ-64565111 in individuals with obesity without type 2 diabetes mellitus: A randomized dose-ranging study.
Individuals with obesity have a heightened risk of developing serious comorbidities, and pharmacological treatments for people with obesity are limited. This phase 2 study assessed the safety and efficacy of JNJ-64565111, a dual agonist of glucagon-like peptide-1 and glucagon receptors, in individuals with class II/III obesity without type 2 diabetes. In this randomized, double-blind, placebo-controlled and open-label active-controlled, parallel-group, multicentre study, participants aged 18 to 70 years with a body mass index of 35 to 50 kg/m Topics: Adolescent; Adult; Aged; Blood Glucose; Diabetes Mellitus, Type 2; Double-Blind Method; Glucagon-Like Peptide 1; Glucagon-Like Peptide-1 Receptor; Glycated Hemoglobin; Humans; Hypoglycemic Agents; Liraglutide; Middle Aged; Obesity; Receptors, Glucagon; Treatment Outcome; Young Adult | 2021 |
Glucagonostatic Potency of GLP-1 in Patients With Type 2 Diabetes, Patients With Type 1 Diabetes, and Healthy Control Subjects.
Hyperglucagonemia is a well-known contributor to diabetic hyperglycemia, and glucagon-like peptide 1 (GLP-1) suppresses glucagon secretion. Reduced inhibitory effects of glucose and GLP-1 on glucagon secretion may contribute to the hyperglucagonemia in diabetes and influence the success of GLP-1 receptor agonist therapy. We examined the dose-response relationship for GLP-1 on glucose-induced glucagon suppression in healthy individuals and patients with type 2 and type 1 diabetes. In randomized order, 10 healthy individuals with normal glucose tolerance, 10 patients with type 2 diabetes, and 9 C-peptide-negative patients with type 1 diabetes underwent 4 separate stepwise glucose clamps (five 30-min steps from fasting level to 15 mmol/L plasma glucose) during simultaneous intravenous infusions of saline or 0.2, 0.4, or 0.8 pmol GLP-1/kg/min. In healthy individuals and patients with type 2 diabetes, GLP-1 potentiated the glucagon-suppressive effect of intravenous glucose in a dose-dependent manner. In patients with type 1 diabetes, no significant changes in glucagon secretion were observed during the clamps whether with saline or GLP-1 infusions. In conclusion, the glucagonostatic potency of GLP-1 during a stepwise glucose clamp is preserved in patients with type 2 diabetes, whereas our patients with type 1 diabetes were insensitive to the glucagonostatic effects of both glucose and GLP-1. Topics: Blood Glucose; Denmark; Diabetes Mellitus, Type 1; Diabetes Mellitus, Type 2; Dose-Response Relationship, Drug; Fasting; Female; Glucagon; Glucagon-Like Peptide 1; Glucose Clamp Technique; Glycated Hemoglobin; Healthy Volunteers; Humans; Male; Middle Aged; Treatment Outcome | 2021 |
The Effect of Antrum Size on Weight Loss, Glucagon-Like Peptide-1 (GLP-1) Levels, and Glycemic Control Following Laparoscopic Sleeve Gastrectomy in Adolescents with Obesity and Type 2 Diabetes.
The aim of this study was to compare the effect of antral resection versus antral preservation sleeve gastrectomy on the post-operative GLP-1, glycemic control, and weight loss in adolescents suffering from severe obesity and type 2 diabetes (T2D).. This study included 36 adolescents. Patients were randomly divided into 2 groups: group (A) and group (B). Each group included 18 patients who underwent LSG, starting transection at 2 cm or 5 cm from the pyloric ring in group (A) and group (B), respectively. They were followed up at 1, 3, 6, 12, and 24 months post-operatively. The outcomes were the post-operative GLP-1 response, glycemic control, weight loss, and safety.. The improvements in the body mass index and the percentage of excess weight loss (%EWL) were statistically significant within each group. The mean GLP-1 levels showed significant increase at the 1, 3, and 6 months but not in the 12 and 24 months in all the studied samples within each group. The mean HbA1c levels and post-prandial serum C-peptide significantly improved within each group (P < 0.05). No statistical differences in the weight loss, %EWL, GLP-1, HbA1c, C-peptide changes, and complication rates were observed between both groups. Diabetic remission was significantly higher (88.9%) in group (A).. LSG resulted in generalized significant GLP-1 initial response that decreased over time. The reduced antrum size did not influence the GLP-1 response, glycemic control, or insulin resistance, but resulted in significantly better T2D remission. Since the study examines a small number of patients, further studies are needed.. ClinicalTrials.gov Identifier: NCT04388059. Topics: Adolescent; Body Mass Index; Diabetes Mellitus, Type 2; Gastrectomy; Glucagon-Like Peptide 1; Glycemic Control; Humans; Laparoscopy; Obesity, Morbid; Pediatric Obesity; Treatment Outcome; Weight Loss | 2021 |
Changes in Bone Mineral Density in Patients with Type 2 Diabetes After Different Bariatric Surgery Procedures and the Role of Gastrointestinal Hormones.
To compare changes in bone mineral density (BMD) in patients with morbid obesity and type 2 diabetes (T2D) a year after being randomized to metabolic gastric bypass (mRYGB), sleeve gastrectomy (SG), and greater curvature plication (GCP). We also analyzed the association of gastrointestinal hormones with skeletal metabolism.. Forty-five patients with T2D (mean BMI 39.4 ± 1.9 kg/m. After surgery, the decrease at femoral neck (FN) was similar but at lumbar spine (LS), it was greater in the mRYGB group compared with SG and GCP - 7.29 (4.6) vs. - 0.48 (3.9) vs. - 1.2 (2.7)%, p < 0.001. Osteocalcin and alkaline phosphatase increased more after mRYGB. Bone mineral content (BMC) at the LS after surgery correlated with fasting ghrelin (r = - 0.412, p = 0.01) and AUC for GLP-1 (r = - 0.402, p = 0.017). FN BMD at 12 months correlated with post-surgical fasting glucagon (r = 0.498, p = 0.04) and insulin AUC (r = 0.384, p = 0.030) and at LS with the AUC for GLP-1 in the same time period (r = - 0.335, p = 0.049). However, in the multiple regression analysis after adjusting for age, sex, and BMI, the type of surgery (mRYGB) remained the only factor associated with BMD reduction at LS and FN.. mRYGB induces greater deleterious effects on the bone at LS compared with SG and GCP, and gastrointestinal hormones do not play a major role in bone changes. Topics: Adult; Bariatric Surgery; Bone and Bones; Bone Density; Bone Remodeling; Diabetes Mellitus, Type 2; Female; Femur Neck; Follow-Up Studies; Gastrointestinal Hormones; Ghrelin; Glucagon; Glucagon-Like Peptide 1; Humans; Insulin; Male; Middle Aged; Obesity, Morbid; Treatment Outcome | 2020 |
Treatment intensification strategies after initial metformin therapy in adult patients with type-2 diabetes: results of the DPV and DIVE registries.
Our study aimed to analyse treatment strategies after failure of initial metformin mono-therapy in adult patients with type-2 diabetes (T2DM).. The DIVE and DPV databases were combined and 16,681 adult patients with T2DM and metformin mono-therapy identified. Patients were analysed depending on whether metformin was continued (MET), or whether it was combined with other oral antidiabetics (OAD), with GLP-1 antagonists (GLP-1) or with basal insulin (BOT/BOT plus). Metabolic control, body weight and hypoglycaemia, micro- and macro-vascular events were compared within 1 year.. A total of 11,911 (71%) participants continued MET until the end of the observation period, 3334 (20.0%) were intensified using OAD, 579 (3%) started on GLP-1, and 857 (5%) were initiated on BOT/BOTplus. Predictors of OAD and BOT/BOTplus therapy were elevated HbA1c, longer diabetes duration and the presence of micro- and macro-vascular diseases, while GLP-1 therapy was predicted by younger age, female sex, higher body weight and shorter diabetes duration. Micro- and macro-vascular diseases were negative predictors of GLP-1 therapy. Effects on HbA1c were highest in the BOT/BOTplus and OAD group, while GLP-1 treatment had the best effect on body weight.. BOT/BOTplus and OAD show good HbA1c reduction even in patients with longer diabetes duration and in older patients. GLP-1 therapy is effective concerning weight loss in overweight patients and is more often used in females and patients with shorter diabetes duration. Interestingly, despite several studies showing positive effects on micro- and macro-vascular outcomes, prevalent macro-vascular diseases are no predictors of GLP-1 use. Topics: Adult; Aged; Blood Glucose; Diabetes Mellitus, Type 2; Drug Therapy, Combination; Female; Germany; Glucagon-Like Peptide 1; Glycated Hemoglobin; Humans; Hypoglycemic Agents; Male; Metformin; Middle Aged; Registries; Treatment Outcome | 2020 |
Efficacy, Safety, and Mechanistic Insights of Cotadutide, a Dual Receptor Glucagon-Like Peptide-1 and Glucagon Agonist.
Cotadutide is a dual receptor agonist with balanced glucagon-like peptide-1 and glucagon activity.. To evaluate different doses of cotadutide and investigate underlying mechanisms for its glucose-lowering effects.. Randomized, double-blind, phase 2a study conducted in 2 cohorts at 5 clinical trial sites.. Participants were 65 adult overweight/obese patients with type 2 diabetes mellitus; 63 completed the study; 2 were withdrawn due to AEs.. Once-daily subcutaneous cotadutide or placebo for 49 days. Doses (50-300 µg) were uptitrated weekly (cohort 1) or biweekly (cohort 2).. Co-primary end points (cohort 1) were percentage changes from baseline to end of treatment in glucose (area under the curve from 0 to 4 hours [AUC0-4h]) post-mixed-meal tolerance test (MMTT) and weight. Exploratory measures included postprandial insulin and gastric emptying time (GET; cohort 2).. Patients received cotadutide (cohort 1, n = 26; cohort 2, n = 20) or placebo (cohort 1, n = 13; cohort 2, n = 6). Significant reductions were observed with cotadutide vs placebo in glucose AUC0-4h post MMTT (least squares mean [90% CI], -21.52% [-25.68, -17.37] vs 6.32% [0.45, 12.20]; P < 0.001) and body weight (-3.41% [-4.37, -2.44] vs -0.08% [-1.45, 1.28]; P = 0.002). A significant increase in insulin AUC0-4h post MMTT was observed with cotadutide (19.3 mU.h/L [5.9, 32.6]; P = 0.008) and GET was prolonged on day 43 with cotadutide vs placebo (t½: 117.2 minutes vs -42.9 minutes; P = 0.0392).. These results suggest that the glucose-lowering effects of cotadutide are mediated by enhanced insulin secretion and delayed gastric emptying.. ClinicalTrials.gov, NCT03244800. Topics: Biomarkers; Diabetes Mellitus, Type 2; Double-Blind Method; Female; Follow-Up Studies; Glucagon; Glucagon-Like Peptide 1; Glucagon-Like Peptide-1 Receptor; Humans; Male; Middle Aged; Obesity; Overweight; Peptides; Prognosis; Receptors, Glucagon | 2020 |
Role of endogenous glucagon-like peptide-1 enhanced by vildagliptin in the glycaemic and energy expenditure responses to intraduodenal fat infusion in type 2 diabetes.
To evaluate the effects of the dipeptidyl peptidase-4 (DPP-4) inhibitor vildagliptin on glycaemic and energy expenditure responses during intraduodenal fat infusion, as well as the contribution of endogenous glucagon-like peptide-1 (GLP-1) signalling, in people with type 2 diabetes (T2DM).. A total of 15 people with T2DM managed by diet and/or metformin (glycated haemoglobin 49.3 ± 2.1 mmol/mol) were studied on three occasions (two with vildagliptin and one with placebo) in a double-blind, randomized, crossover fashion. On each day, vildagliptin 50 mg or placebo was given orally, followed by intravenous exendin (9-39) 600 pmol/kg/min, on one of the two vildagliptin treatment days, or 0.9% saline over 180 minutes. At between 0 and 120 minutes, a fat emulsion was infused intraduodenally at 2 kcal/min. Energy expenditure, plasma glucose and glucose-regulatory hormones were evaluated.. Intraduodenal fat increased plasma GLP-1 and glucose-dependent insulinotropic polypeptide (GIP), insulin and glucagon, and energy expenditure, and decreased plasma glucose (all P < 0.05). On the two intravenous saline days, plasma glucose and glucagon were lower, plasma intact GLP-1 was higher (all P < 0.05), and energy expenditure tended to be lower after vildagliptin (P = 0.08) than placebo. On the two vildagliptin days, plasma glucose, glucagon and GLP-1 (both total and intact), and energy expenditure were higher during intravenous exendin (9-39) than saline (all P < 0.05).. In well-controlled T2DM during intraduodenal fat infusion, vildagliptin lowered plasma glucose and glucagon, and tended to decrease energy expenditure, effects that were mediated by endogenous GLP-1. Topics: Adamantane; Blood Glucose; Diabetes Mellitus, Type 2; Energy Metabolism; Gastric Inhibitory Polypeptide; Glucagon-Like Peptide 1; Humans; Insulin; Nitriles; Pyrrolidines; Vildagliptin | 2020 |
GLP-1 secretion is regulated by IL-6 signalling: a randomised, placebo-controlled study.
IL-6 is a cytokine with various effects on metabolism. In mice, IL-6 improved beta cell function and glucose homeostasis via upregulation of glucagon-like peptide 1 (GLP-1), and IL-6 release from muscle during exercise potentiated this beneficial increase in GLP-1. This study aimed to identify whether exercise-induced IL-6 has a similar effect in humans.. In a multicentre, double-blind clinical trial, we randomly assigned patients with type 2 diabetes or obesity to intravenous tocilizumab (an IL-6 receptor antagonist) 8 mg/kg every 4 weeks, oral sitagliptin (a dipeptidyl peptidase-4 inhibitor) 100 mg daily or double placebos (a placebo saline infusion every 4 weeks and a placebo pill once daily) during a 12 week training intervention. The primary endpoints were the difference in change of active GLP-1 response to an acute exercise bout and change in the AUC for the concentration-time curve of active GLP-1 during mixed meal tolerance tests at baseline and after the training intervention.. Nineteen patients were allocated to tocilizumab, 17 to sitagliptin and 16 to placebos. During the acute exercise bout active GLP-1 levels were 26% lower with tocilizumab (multiplicative effect: 0.74 [95% CI 0.56, 0.98], p = 0.034) and 53% higher with sitagliptin (1.53 [1.15, 2.03], p = 0.004) compared with placebo. After the 12 week training intervention, the active GLP-1 AUC with sitagliptin was about twofold that with placebo (2.03 [1.56, 2.62]; p < 0.001), while GLP-1 AUC values showed a small non-significant decrease of 13% at 4 weeks after the last tocilizumab infusion (0.87 [0.67, 1.12]; p = 0.261).. IL-6 is implicated in the regulation of GLP-1 in humans. IL-6 receptor blockade lowered active GLP-1 levels in response to a meal and an acute exercise bout in a reversible manner, without lasting effects beyond IL-6 receptor blockade.. Clinicaltrials.gov NCT01073826.. Danish National Research Foundation. Danish Council for Independent Research. Novo Nordisk Foundation. Danish Centre for Strategic Research in Type 2 Diabetes. European Foundation for the Study of Diabetes. Swiss National Research Foundation. Topics: Antibodies, Monoclonal, Humanized; Diabetes Mellitus, Type 2; Double-Blind Method; Exercise; Female; Glucagon-Like Peptide 1; Humans; Interleukin-6; Male; Obesity; Receptors, Interleukin-6; Sitagliptin Phosphate | 2020 |
Endogenously released GIP reduces and GLP-1 increases hepatic insulin extraction.
GIP was proposed to play a key role in the development of non- alcoholic fatty liver disease (NAFLD) in response to sugar intake. Isomaltulose, is a 1,6-linked glucose-fructose dimer which improves glucose homeostasis and prevents NAFLD compared to 1,2-linked sucrose by reducing glucose-dependent insulinotropic peptide (GIP) in mice. We compared effects of sucrose vs. isomaltulose on GIP and glucagon-like peptide-1 (GLP-1) secretion, hepatic insulin clearance (HIC) and insulin sensitivity in normal (NGT), impaired glucose tolerant (IGT) and Type 2 diabetes mellitus (T2DM) participants. A randomized crossover study was performed in 15 NGT, 10 IGT and 10 T2DM subjects. In comparison to sucrose, peak glucose concentrations were reduced by 2.3, 2.1 and 2.5 mmol/l (all p < 0.05) and insulin levels were 88% (p < 0.01, NGT), 32% (p < 0.05, IGT) and 55% (T2DM) lower after the isomaltulose load. Postprandial GIP Topics: Adult; Case-Control Studies; Cross-Over Studies; Diabetes Mellitus, Type 2; Female; Gastric Inhibitory Polypeptide; Glucagon-Like Peptide 1; Humans; Incretins; Insulin; Insulin Resistance; Isomaltose; Liver; Male; Middle Aged; Sucrose | 2020 |
No Acute Effects of Exogenous Glucose-Dependent Insulinotropic Polypeptide on Energy Intake, Appetite, or Energy Expenditure When Added to Treatment With a Long-Acting Glucagon-Like Peptide 1 Receptor Agonist in Men With Type 2 Diabetes.
Dual incretin receptor agonists in clinical development have shown reductions in body weight and hemoglobin A. Energy intake was similar during GIP and placebo infusion (648 ± 74 kcal vs. 594 ± 55 kcal, respectively;. In patients with type 2 diabetes, GIP infusion on top of treatment with metformin and a long-acting GLP-1R agonist did not affect energy intake, appetite, or energy expenditure but increased plasma glucose compared with placebo. These results indicate no acute beneficial effects of combining GIP and GLP-1. Topics: Adult; Aged; Appetite; Delayed-Action Preparations; Diabetes Mellitus, Type 2; Double-Blind Method; Drug Administration Schedule; Drug Therapy, Combination; Energy Intake; Energy Metabolism; Gastric Inhibitory Polypeptide; Glucagon; Glucagon-Like Peptide 1; Glucagon-Like Peptide-1 Receptor; Glycated Hemoglobin; Humans; Insulin; Male; Middle Aged | 2020 |
Late-night-dinner deteriorates postprandial glucose and insulin whereas consuming dinner dividedly ameliorates them in patients with type 2 diabetes: A randomized crossover clinical trial.
The aims of this study is to explore the acute effect of consuming dinner at different timing on postprandial glucose and hormone in patients with type 2 diabetes.. Eight patients (age 70.8±1.9 years, HbA1c 7.6±0.6 %, BMI 23.3±3.2, mean±SD) were randomly assigned in this crossover study. Patients consumed the test meals of dinner at 18:00 on the first day, and dinner at 21:00 or divided dinner (vegetable and rice at 18:00 and vegetable and the main dish at 21:00) on the second or third day. Postprandial glucose, insulin, glucagon, free fatty acid (FFA), active glucagon-like peptide-1 (GLP-1), and active glucose- dependent insulinotropic polypeptide (GIP) concentration after dinner were evaluated.. Both incremental area under the curve (IAUC) 2h for glucose and insulin were higher in dinner at 21:00 than those in dinner at 18:00 (IAUC glucose: 449±83 vs 216±43 mmol/L×min, p<0.01, IAUC insulin:772±104 vs 527±107 μU/mL×min, p<0.01, mean±SEM). However, in divided dinner both IAUC 4h for glucose and insulin tended to be lower than those of dinner at 21:00 (IAUC glucose: 269±76 mmol/L×min, p=0.070, IAUC insulin: 552±114 μU/mL×min, p=0.070). IAUC of active GLP-1 and active GIP demonstrated no difference among different dinner regimen.. Consuming late-night-dinner (21:00) deteriorates postprandial glucose and insulin compared with those of early-evening-dinner (18:00) whereas consuming dinner dividedly ameliorates them. Topics: Aged; Area Under Curve; Cross-Over Studies; Diabetes Mellitus, Type 2; Fatty Acids, Nonesterified; Female; Gastric Inhibitory Polypeptide; Glucagon; Glucagon-Like Peptide 1; Glucose; Humans; Insulin; Japan; Male; Meals; Middle Aged; Postprandial Period | 2020 |
Ileo-colonic delivery of conjugated bile acids improves glucose homeostasis via colonic GLP-1-producing enteroendocrine cells in human obesity and diabetes.
The bile acid (BA) pathway plays a role in regulation of food intake and glucose metabolism, based mainly on findings in animal models. Our aim was to determine whether the BA pathway is altered and correctable in human obesity and diabetes.. We conducted 3 investigations: 1) BA receptor pathways were studied in NCI-H716 enteroendocrine cell (EEC) line, whole human colonic mucosal tissue and in human colonic EEC isolated by Fluorescence-activated Cell Sorting (ex vivo) from endoscopically-obtained biopsies colon mucosa; 2) We characterized the BA pathway in 307 participants by measuring during fasting and postprandial levels of FGF19, 7αC4 and serum BA; 3) In a placebo-controlled, double-blind, randomised, 28-day trial, we studied the effect of ileo-colonic delivery of conjugated BAs (IC-CBAS) on glucose metabolism, incretins, and lipids, in participants with obesity and diabetes.. Human colonic GLP-1-producing EECs express TGR5, and upon treatment with bile acids in vitro, human EEC differentially expressed GLP-1 at the protein and mRNA level. In Ussing Chamber, GLP-1 release was stimulated by Taurocholic acid in either the apical or basolateral compartment. FGF19 was decreased in obesity and diabetes compared to controls. When compared to placebo, IC-CBAS significantly decreased postprandial glucose, fructosamine, fasting insulin, fasting LDL, and postprandial FGF19 and increased postprandial GLP-1 and C-peptide. Increase in faecal BA was associated with weight loss and with decreased fructosamine.. In humans, BA signalling machinery is expressed in colonic EECs, deficient in obesity and diabetes, and when stimulated with IC-CBAS, improved glucose homeostasis. ClinicalTrials.gov number, NCT02871882, NCT02033876.. Research support and drug was provided by Satiogen Pharmaceuticals (San Diego, CA). AA, MC, and NFL report grants (AA- C-Sig P30DK84567, K23 DK114460; MC- NIH R01 DK67071; NFL- R01 DK057993) from the NIH. JR was supported by an Early Career Grant from Society for Endocrinology. Topics: Administration, Oral; Bile Acids and Salts; Biological Transport; Blood Glucose; Capsules; Cell Line; Cholestenones; Colon; Diabetes Mellitus, Type 2; Diffusion Chambers, Culture; Enteroendocrine Cells; Fasting; Fibroblast Growth Factors; Fructosamine; Gene Expression; Glucagon-Like Peptide 1; Homeostasis; Humans; Ileum; Insulin; Obesity; Postprandial Period; Primary Cell Culture; Receptors, G-Protein-Coupled | 2020 |
Glycemic variability in newly diagnosed diabetic cats treated with the glucagon-like peptide-1 analogue exenatide extended release.
Glycemic variability (GV) is an indicator of glycemic control and can be evaluated by calculating the SD of blood glucose measurements. In humans with diabetes mellitus (DM), adding a glucagon-like peptide-1 (GLP-1) analogue to conventional therapy reduces GV. In diabetic cats, the influence of GLP-1 analogues on GV is unknown.. To evaluate GV in diabetic cats receiving the GLP-1 analogue exenatide extended release (EER) and insulin.. Thirty client-owned cats with newly diagnosed spontaneous DM.. Retrospective study. Blood glucose curves from a recent prospective placebo-controlled clinical trial generated 1, 3, 6, 10, and 16 weeks after starting therapy were retrospectively evaluated for GV. Cats received either EER (200 μg/kg) or 0.9% saline SC once weekly, insulin glargine and a low-carbohydrate diet. Mean blood glucose concentrations were calculated and GV was assessed by SD. Data were analyzed using nonparametric tests.. In the EER group, GV (mean SD [95% confidence interval]) was lower at weeks 6 (1.69 mmol/L [0.9-2.48]; P = .02), 10 (1.14 mmol/L [0.66-1.62]; P = .002) and 16 (1.66 mmol/L [1.09-2.23]; P = .02) compared to week 1 (4.21 mmol/L [2.48-5.93]) and lower compared to placebo at week 6 (3.29 mmol/L [1.95-4.63]; P = .04) and week 10 (4.34 mmol/L [2.43-6.24]; P < .000). Cats achieving remission (1.21 mmol/L [0.23-2.19]) had lower GV compared to those without remission (2.96 mmol/L [1.97-3.96]; P = .01) at week 6.. The combination of EER, insulin, and a low-carbohydrate diet might be advantageous in the treatment of newly diagnosed diabetic cats. Topics: Animals; Blood Glucose; Cat Diseases; Cats; Diabetes Mellitus; Diabetes Mellitus, Type 2; Exenatide; Glucagon-Like Peptide 1; Hypoglycemic Agents; Insulin; Prospective Studies; Retrospective Studies | 2020 |
An Almond-Based Low Carbohydrate Diet Improves Depression and Glycometabolism in Patients with Type 2 Diabetes through Modulating Gut Microbiota and GLP-1: A Randomized Controlled Trial.
Alow carbohydrate diet (LCD) is more beneficial for the glycometabolism in type 2 diabetes (T2DM) and may be effective in reducing depression. Almond, which is a common nut, has been shown to effectively improve hyperglycemia and depression symptoms. This study aimed to determine the effect of an almond-based LCD (a-LCD) on depression and glycometabolism, as well as gut microbiota and fasting glucagon-like peptide 1 (GLP-1) in patients with T2DM.. This was a randomized controlled trial which compared an a-LCD with a low-fat diet (LFD). Forty-five participants with T2DM at a diabetes club and the Endocrine Division of the First and Second Affiliated Hospital of Soochow University between December 2018 to December 2019 completed each dietary intervention for 3 months, including 22 in the a-LCD group and 23 in the LFD group. The indicators for depression and biochemical indicators including glycosylated hemoglobin (HbA1c), gut microbiota, and GLP-1 concentration were assessed at the baseline and third month and compared between the two groups.. A-LCD significantly improved depression and HbA1c (. A-LCD could exert a beneficial effect on depression and glycometabolism in patients with T2DM. We speculate that the role of a-LCD in improving depression in patients with T2DM may be associated with it stimulating the growth of SCFAs-producing bacteria, increasing SCFAs production and GPR43 activation, and further maintaining GLP-1 secretion. In future studies, the SCFAs and GPR43 activation should be further examined. Topics: Aged; Blood Glucose; Depression; Diabetes Mellitus, Type 2; Diet, Carbohydrate-Restricted; Fasting; Feces; Female; Gastrointestinal Microbiome; Glucagon-Like Peptide 1; Glycated Hemoglobin; Glycemic Control; Humans; Male; Prospective Studies; Prunus dulcis; Treatment Outcome | 2020 |
The insulinotropic effect of a high-protein nutrient preload is mediated by the increase of plasma amino acids in type 2 diabetes.
Eating protein before carbohydrate reduces postprandial glucose excursions by enhancing insulin and glucagon-like peptide-1 (GLP-1) secretion in type 2 diabetes (T2D). We tested the hypothesis that this insulinotropic effect depends on the elevation of plasma amino acids (AA) after the digestion of food protein.. In 16 T2D patients, we measured plasma AA levels through the course of two 75-g oral glucose tolerance tests (OGTT) preceded by either 500-ml water or a high-protein nutrient preload (50-g Parmesan cheese, one boiled egg, and 300-ml water). Changes in beta cell function were evaluated by measuring and modelling plasma glucose, insulin, and C-peptide through the OGTT. Changes in incretin hormone secretion were assessed by measuring plasma GLP-1.. Plasma AA levels were 24% higher after the nutrient preload (p < 0.0001). This increment was directly proportional to both the enhancement of beta cell function (r = 0.58, p = 0.02) and the plasma GLP-1 gradients (r = 0.57, p = 0.02) produced by the nutrient preload. Among single AA, glutamine showed the strongest correlation with changes in beta cell function (r = 0.61, p = 0.01), while leucine showed the strongest correlation with GLP-1 responses (r = 0.74, p = 0.001).. The elevation of circulating AA that occurs after a high-protein nutrient preload is associated with an enhancement of beta cell function and GLP-1 secretion in T2D. Manipulating the meal sequence of nutrient ingestion may reduce postprandial hyperglycaemia through a direct and GLP-1-mediated stimulation of insulin secretion by plasma AA.. NCT02342834. Topics: Adult; Aged; Amino Acids; Cross-Over Studies; Diabetes Mellitus, Type 2; Dietary Proteins; Female; Glucagon-Like Peptide 1; Humans; Insulin; Male; Middle Aged; Postprandial Period | 2019 |
GI Dysfunctions in Diabetic Gastroenteropathy, Their Relationships With Symptoms, and Effects of a GLP-1 Antagonist.
Delayed gastric emptying (GE) is common but often asymptomatic in diabetes. The relationship between symptoms, glycemia, and neurohormonal functions, including glucagonlike peptide 1 (GLP-1), are unclear.. To assess whether GE disturbances, symptoms during a GE study, and symptoms during enteral lipid infusion explain daily symptoms and whether GLP-1 mediates symptoms during enteral lipid infusion.. In this randomized controlled trial, GE, enteral lipid infusion, gastrointestinal (GI) symptoms during these assessments, autonomic functions, glycosylated hemoglobin (HbA1c), and daily GI symptoms (2-week Gastroparesis Cardinal Symptom Index diary) were evaluated. During enteral lipid infusion, participants received the GLP-1 antagonist exendin 9-39 or placebo.. Single tertiary referral center.. 24 healthy controls and 40 patients with diabetic gastroenteropathy.. GE, symptoms during enteral lipid infusion, and the effect of exendin 9-39 on the latter.. In patients, GE was normal (55%), delayed (33%), or rapid (12%). During lipid infusion, GI symptoms tended to be greater (P = 0.06) in patients with diabetes mellitus (DM) than controls; exendin 9-39 did not affect symptoms. The HbA1c was inversely correlated with the mean symptom score during the GE study (r = -0.46, P = 0.003) and lipid infusion (r = -0.47, P < 0.01). GE and symptoms during GE study accounted for 40% and 32%, respectively, of the variance in daily symptom severity and quality of life.. In DM gastroenteropathy, GE and symptoms during a GE study explain daily symptoms. Symptoms during enteral lipid infusion were borderline increased but not reduced by a GLP-1 antagonist. Topics: Administration, Oral; Adult; Asymptomatic Diseases; Blood Glucose; Diabetes Mellitus, Type 1; Diabetes Mellitus, Type 2; Emulsions; Female; Gastric Emptying; Gastrointestinal Diseases; Glucagon-Like Peptide 1; Glycated Hemoglobin; Humans; Lipids; Male; Middle Aged; Peptide Fragments; Quality of Life; Treatment Outcome | 2019 |
Comparative effects of proximal and distal small intestinal administration of metformin on plasma glucose and glucagon-like peptide-1, and gastric emptying after oral glucose, in type 2 diabetes.
The gastrointestinal tract, particularly the lower gut, may be key to the anti-diabetic action of metformin. We evaluated whether administration of metformin into the distal, vs the proximal, small intestine would be more effective in lowering plasma glucose by stimulating glucagon-like pepetide-1 (GLP-1) and/or slowing gastric emptying (GE) in type 2 diabetes (T2DM).. Ten diet-controlled T2DM patients were studied on three occasions. A transnasal catheter was positioned with proximal and distal infusion ports located 13 and 190 cm beyond the pylorus, respectively. Participants received infusions of (a) proximal + distal saline (control), (b) proximal metformin (1000 mg) + distal saline or (c) proximal saline + distal metformin (1000 mg) over 5 minutes, followed 60 minutes later by a glucose drink containing 50 g glucose and 150 mg. Compared with control, both proximal and distal metformin reduced plasma glucose and augmented GLP-1 responses to oral glucose comparably (P < 0.05 each), without affecting plasma insulin or glucagon. GE was slower after proximal metformin than after control (P < 0.05) and tended to be slower after distal metformin, without any difference between proximal and distal metformin.. In diet-controlled T2DM patients, glucose-lowering via a single dose of metformin administered to the upper and lower gut was comparable and was associated with stimulation of GLP-1 and slowing of GE. These observations suggest that the site of gastrointestinal administration is not critical to the glucose-lowering capacity of metformin. Topics: Aged; Blood Glucose; Diabetes Mellitus, Type 2; Drug Administration Routes; Female; Gastric Emptying; Glucagon-Like Peptide 1; Glucose; Glucose Tolerance Test; Humans; Intestine, Small; Male; Metformin; Middle Aged | 2019 |
A whey/guar "preload" improves postprandial glycaemia and glycated haemoglobin levels in type 2 diabetes: A 12-week, single-blind, randomized, placebo-controlled trial.
To evaluate the effects of 12 weeks of treatment with a whey/guar preload on gastric emptying, postprandial glycaemia and glycated haemoglobin (HbA1c) levels in people with type 2 diabetes (T2DM).. A total of 79 people with T2DM, managed on diet or metformin (HbA1c 49 ± 0.7 mmol/mol [6.6 ± 0.1%]), were randomized, in single-blind fashion, to receive 150 mL flavoured preloads, containing either 17 g whey protein plus 5 g guar (n = 37) or flavoured placebo (n = 42), 15 minutes before two meals, each day for 12 weeks. Blood glucose and gastric emptying (breath test) were measured before and after a mashed potato meal at baseline (without preload), and after the preload at the beginning (week 1) and end (week 12) of treatment. HbA1c levels, energy intake, weight and body composition were also evaluated.. Gastric emptying was slower (P < 0.01) and postprandial blood glucose levels lower (P < 0.05) with the whey/guar preload compared to placebo preload, and the magnitude of reduction in glycaemia was related to the rate of gastric emptying at both week 1 (r = -0.54, P < 0.001) and week 12 (r = -0.54, P < 0.0001). At the end of treatment, there was a 1 mmol/mol [0.1%] reduction in HbA1c in the whey/guar group compared to the placebo group (49 ± 1.0 mmol/mol [6.6 ± 0.05%] vs. 50 ± 0.8 mmol/mol [6.7 ± 0.05%]; P < 0.05). There were no differences in energy intake, body weight, or lean or fat mass between the groups.. In patients with well-controlled T2DM, 12 weeks' treatment with a low-dose whey/guar preload, taken twice daily before meals, had sustained effects of slowing gastric emptying and reducing postprandial blood glucose, which were associated with a modest reduction in HbA1c, without causing weight gain. Topics: Aged; Blood Glucose; Body Composition; Body Weight; Diabetes Mellitus, Type 2; Diet, Diabetic; Energy Intake; Female; Galactans; Gastric Emptying; Glucagon; Glucagon-Like Peptide 1; Glycated Hemoglobin; Humans; Hypoglycemic Agents; Insulin; Male; Mannans; Metformin; Middle Aged; Plant Gums; Postprandial Period; Single-Blind Method; Whey Proteins | 2019 |
Safety and Pharmacokinetics of Single and Multiple Ascending Doses of the Novel Oral Human GLP-1 Analogue, Oral Semaglutide, in Healthy Subjects and Subjects with Type 2 Diabetes.
Oral semaglutide is a novel tablet containing the human glucagon-like peptide-1 (GLP‑1) analogue semaglutide, co-formulated with the absorption enhancer sodium N-(8-[2-hydroxybenzoyl] amino) caprylate (SNAC). The safety and pharmacokinetics of oral semaglutide were investigated in two randomised, double-blind, placebo-controlled trials.. In a single-dose, first-in-human trial, 135 healthy males received oral semaglutide (2-20 mg semaglutide co-formulated with 150-600 mg SNAC) or placebo with SNAC. In a 10-week, once-daily, multiple-dose trial, 84 healthy males received 20 or 40 mg oral semaglutide (with 300 mg SNAC), placebo, or placebo with SNAC, and 23 males with type 2 diabetes (T2D) received 40 mg oral semaglutide (with 300 mg SNAC), placebo, or placebo with SNAC.. Oral semaglutide was safe and well-tolerated in both trials. The majority of adverse events (AEs) were mild, with the most common AEs being gastrointestinal disorders. In the single-dose trial, semaglutide exposure was highest when co-formulated with 300 mg SNAC. In the multiple-dose trial, semaglutide exposure was approximately twofold higher with 40 versus 20 mg oral semaglutide in healthy males, in accordance with dose proportionality, and was similar between healthy males and males with T2D. The half-life of semaglutide was approximately 1 week in all groups.. The safety profile of oral semaglutide was as expected for the GLP-1 receptor agonist drug class. Oral semaglutide co-formulated with 300 mg SNAC was chosen for further clinical development. The pharmacokinetic results supported that oral semaglutide is suitable for once-daily dosing. CLINICALTRIALS.. NCT01037582, NCT01686945. Topics: Administration, Oral; Adolescent; Adult; Area Under Curve; Diabetes Mellitus, Type 2; Dose-Response Relationship, Drug; Double-Blind Method; Glucagon-Like Peptide 1; Glucagon-Like Peptides; Healthy Volunteers; Humans; Hypoglycemic Agents; Male; Metabolic Clearance Rate; Middle Aged; Young Adult | 2019 |
Postprandial Effects of Blueberry (
The consumption of blueberries, as well as the phenolic compounds they contain, may alter metabolic processes related to type 2 diabetes. The study investigated the effects of adding 140 g of blueberries to a higher-carbohydrate breakfast meal on postprandial glucose metabolism, gastrointestinal hormone response, and perceived appetite. As part of a randomized crossover design study, 17 healthy adults consumed a standardized higher-carbohydrate breakfast along with 2 treatments: (1) 140 g (1 cup) of whole blueberries and (2) a placebo gel (matched for calories, sugars, and fiber of the whole blueberries). Each subject participated in two 2-h meal tests on separate visits ≥8 days apart. Venous blood samples and perceived appetite ratings using visual analog scales were obtained prior to and at 30, 60, 90, and 120 min after consuming the breakfast meals. Results show that glucose metabolism, several gastrointestinal hormones, glucagon-like peptide-1 (GLP-1), glucose-dependent insulinotropic peptide (GIP), peptide YY (PYY) concentrations and perceived appetite did not change significantly with blueberry consumption. However, pancreatic polypeptide (PP) concentrations were statistically significantly higher ( Topics: Adult; Appetite; Blood Glucose; Blueberry Plants; Breakfast; Cross-Over Studies; Diabetes Mellitus, Type 2; Energy Intake; Female; Fruit; Gastric Inhibitory Polypeptide; Gastrointestinal Hormones; Glucagon-Like Peptide 1; Humans; Male; Middle Aged; Pancreas; Pancreatic Polypeptide; Peptide YY; Polyphenols; Postprandial Period; Reference Values; Young Adult | 2019 |
Comparative Effects of Proximal and Distal Small Intestinal Glucose Exposure on Glycemia, Incretin Hormone Secretion, and the Incretin Effect in Health and Type 2 Diabetes.
Cells releasing glucose-dependent insulinotropic polypeptide (GIP) and glucagon-like peptide 1 (GLP-1) are distributed predominately in the proximal and distal gut, respectively. Hence, the region of gut exposed to nutrients may influence GIP and GLP-1 secretion and impact on the incretin effect and gastrointestinal-mediated glucose disposal (GIGD). We evaluated glycemic and incretin responses to glucose administered into the proximal or distal small intestine and quantified the corresponding incretin effect and GIGD in health and type 2 diabetes mellitus (T2DM).. Ten healthy subjects and 10 patients with T2DM were each studied on four occasions. On two days, a transnasal catheter was positioned with infusion ports opening 13 cm and 190 cm beyond the pylorus, and 30 g glucose with 3 g 3-. In both groups, blood glucose and serum 3-. The distal, as opposed to proximal, small intestine is superior in modulating postprandial glucose metabolism in both health and T2DM. Topics: Adult; Blood Glucose; Diabetes Mellitus, Type 2; Double-Blind Method; Drug Administration Routes; Female; Gastric Inhibitory Polypeptide; Glucagon-Like Peptide 1; Glucose; Healthy Volunteers; Humans; Incretins; Insulin; Intestine, Small; Male; Middle Aged; Postprandial Period | 2019 |
Liver-derived fibroblast growth factor 21 mediates effects of glucagon-like peptide-1 in attenuating hepatic glucose output.
Glucagon-like peptide-1 (GLP-1) and its based agents improve glycemic control. Although their attenuating effect on hepatic glucose output has drawn our attention for decades, the potential mechanisms remain unclear.. Cytokine array kit was used to assess cytokine profiles in db/db mice and mouse primary hepatocytes treated with exenatide (exendin-4). Two diabetic mouse models (db/db and Pax6. Utilizing the cytokine array, we identified that FGF21 secretion was upregulated by exenatide (exendin-4). Similarly, FGF21 production in hepatocytes was stimulated by exenatide or liraglutide. FGF21 blockage attenuated the inhibitory effects of the GLP-1 analogs on hepatic glucose output. Similar results were also observed in primary hepatocytes from Fgf21 knockout mice. Furthermore, exenatide treatment increased serum FGF21 level in patients with T2D, particularly in those with better glucose control.. We identify that function of GLP-1 in inhibiting hepatic glucose output is mediated via the liver hormone FGF21. Thus, we provide a new extra-pancreatic mechanism by which GLP-1 regulates glucose homeostasis. FUND: National Key Research and Development Program of China, the National Natural Science Foundation of China, the Natural Science Foundation of Beijing and Peking University Medicine Seed Fund for Interdisciplinary Research. Topics: Adult; Aged; Animals; Cells, Cultured; Diabetes Mellitus, Type 2; Exenatide; Fibroblast Growth Factors; Glucagon-Like Peptide 1; Gluconeogenesis; Glucose; Hep G2 Cells; Humans; Hypoglycemic Agents; Liraglutide; Liver; Male; Mice; Mice, Inbred C57BL; Middle Aged | 2019 |
Effect of Additional Oral Semaglutide vs Sitagliptin on Glycated Hemoglobin in Adults With Type 2 Diabetes Uncontrolled With Metformin Alone or With Sulfonylurea: The PIONEER 3 Randomized Clinical Trial.
Phase 3 trials have not compared oral semaglutide, a glucagon-like peptide 1 receptor agonist, with other classes of glucose-lowering therapy.. To compare efficacy and assess long-term adverse event profiles of once-daily oral semaglutide vs sitagliptin, 100 mg added on to metformin with or without sulfonylurea, in patients with type 2 diabetes.. Randomized, double-blind, double-dummy, parallel-group, phase 3a trial conducted at 206 sites in 14 countries over 78 weeks from February 2016 to March 2018. Of 2463 patients screened, 1864 adults with type 2 diabetes uncontrolled with metformin with or without sulfonylurea were randomized.. Patients were randomized to receive once-daily oral semaglutide, 3 mg (n = 466), 7 mg (n = 466), or 14 mg (n = 465), or sitagliptin, 100 mg (n = 467). Semaglutide was initiated at 3 mg/d and escalated every 4 weeks, first to 7 mg/d then to 14 mg/d, until the randomized dosage was achieved.. The primary end point was change in glycated hemoglobin (HbA1c), and the key secondary end point was change in body weight, both from baseline to week 26. Both were assessed at weeks 52 and 78 as additional secondary end points. End points were tested for noninferiority with respect to HbA1c (noninferiority margin, 0.3%) prior to testing for superiority of HbA1c and body weight.. Among 1864 patients randomized (mean age, 58 [SD, 10] years; mean baseline HbA1c, 8.3% [SD, 0.9%]; mean body mass index, 32.5 [SD, 6.4]; n=879 [47.2%] women), 1758 (94.3%) completed the trial and 298 prematurely discontinued treatment (16.7% for semaglutide, 3 mg/d; 15.0% for semaglutide, 7 mg/d; 19.1% for semaglutide, 14 mg/d; and 13.1% for sitagliptin). Semaglutide, 7 and 14 mg/d, compared with sitagliptin, significantly reduced HbA1c (differences, -0.3% [95% CI, -0.4% to -0.1%] and -0.5% [95% CI, -0.6% to -0.4%], respectively; P < .001 for both) and body weight (differences, -1.6 kg [95% CI, -2.0 to -1.1 kg] and -2.5 kg [95% CI, -3.0 to -2.0 kg], respectively; P < .001 for both) from baseline to week 26. Noninferiority of semaglutide, 3 mg/d, with respect to HbA1c was not demonstrated. Week 78 reductions in both end points were statistically significantly greater with semaglutide, 14 mg/d, vs sitagliptin.. Among adults with type 2 diabetes uncontrolled with metformin with or without sulfonylurea, oral semaglutide, 7 mg/d and 14 mg/d, compared with sitagliptin, resulted in significantly greater reductions in HbA1c over 26 weeks, but there was no significant benefit with the 3-mg/d dosage. Further research is needed to assess effectiveness in a clinical setting.. ClinicalTrials.gov Identifier: NCT02607865. Topics: Administration, Oral; Adult; Diabetes Mellitus, Type 2; Dose-Response Relationship, Drug; Double-Blind Method; Drug Therapy, Combination; Female; Glucagon-Like Peptide 1; Glucagon-Like Peptides; Glycated Hemoglobin; Humans; Hypoglycemic Agents; Male; Metformin; Middle Aged; Sitagliptin Phosphate; Sulfonylurea Compounds | 2019 |
Assessment of Drug-Drug Interactions between Taspoglutide, a Glucagon-Like Peptide-1 Agonist, and Drugs Commonly Used in Type 2 Diabetes Mellitus: Results of Five Phase I Trials.
Taspoglutide, a glucagon-like peptide-1 agonist, like native glucagon-like peptide-1, delays gastric emptying time and prolongs intestinal transit time, which may alter the pharmacokinetics of concomitantly administered oral drugs. The effect of taspoglutide on the pharmacokinetics of five oral drugs commonly used in patients with type 2 diabetes mellitus was assessed in healthy subjects.. Five clinical pharmacology studies evaluated the potential drug-drug interaction between multiple subcutaneous taspoglutide doses and a single dose of lisinopril, warfarin, and simvastatin and multiple doses of digoxin and an oral contraceptive containing ethinylestradiol and levonorgestrel. The extent of interaction was quantified using geometric mean ratios and 90% confidence intervals for the maximum plasma concentration and area under the plasma concentration-time curve. In addition to pharmacokinetics, pharmacodynamic effects were assessed for warfarin and the oral contraceptive.. Among the tested drugs, the effect of taspoglutide on the pharmacokinetics of simvastatin was most pronounced, on the day of taspoglutide administration, the average exposure to simvastatin was decreased by - 26% and - 58% for the area under the plasma concentration-time curve and maximum plasma concentration, respectively, accompanied by an increase in average exposure to its active metabolite, simvastatin β-hydroxy acid (+ 74% and + 23% for area under the plasma concentration-time curve and maximum plasma concentration, respectively). Although statistically significant changes in exposure were observed for other test drugs, the 90% confidence intervals for the geometric mean ratio for maximum plasma concentration and area under the plasma concentration-time curve were within the 0.7-1.3 interval. No clinically relevant changes on coagulation (for warfarin) and ovulation-suppressing activity (for the oral contraceptive) were apparent.. Overall, multiple doses of taspoglutide did not result in changes in the pharmacokinetics of digoxin, an oral contraceptive containing ethinylestradiol and levonorgestrel, lisinopril, warfarin, and simvastatin that would be considered of clinical relevance. Therefore, no dose adjustments are warranted upon co-administration. Topics: Administration, Oral; Adult; Angiotensin-Converting Enzyme Inhibitors; Anticholesteremic Agents; Anticoagulants; Cardiotonic Agents; Case-Control Studies; Contraceptives, Oral; Diabetes Mellitus, Type 2; Digoxin; Drug Interactions; Female; Glucagon-Like Peptide 1; Healthy Volunteers; Humans; Injections, Subcutaneous; Lisinopril; Male; Middle Aged; Peptides; Pharmaceutical Preparations; Simvastatin; Warfarin | 2019 |
Efficacy and safety of an albiglutide liquid formulation compared with the lyophilized formulation: A 26-week randomized, double-blind, repeat-dose study in patients with type 2 diabetes mellitus.
Compare the efficacy and safety of albiglutide from a ready-to-use, single-dose, auto-injector system with the lyophilized product in patients with type 2 diabetes mellitus (T2DM).. In this phase 3 study, 308 patients between 18 and 80 years with T2DM and experiencing inadequate glycemic control on their current regimen of diet/exercise alone or in combination with metformin were randomized 1:1 to weekly injections for 26 weeks with an active albiglutide auto-injector and placebo lyophilized dual-chamber cartridge (DCC) pen injector (n = 154) or active albiglutide lyophilized DCC pen injector and placebo liquid auto-injector (n = 154). Participants received liquid or lyophilized albiglutide 30 mg for 4 weeks, and then 50 mg for the remaining 22 weeks. Change in HbA. Change from baseline in HbA Topics: Adolescent; Adult; Aged; Aged, 80 and over; Blood Glucose; Diabetes Mellitus, Type 2; Dose-Response Relationship, Drug; Double-Blind Method; Drug Administration Schedule; Drug Compounding; Female; Freeze Drying; Glucagon-Like Peptide 1; Glycated Hemoglobin; Humans; Hypoglycemic Agents; Male; Metformin; Middle Aged; Solutions; Treatment Outcome; Young Adult | 2019 |
A randomized trial comparing the efficacy and safety of treating patients with type 2 diabetes and highly elevated HbA1c levels with basal-bolus insulin or a glucagon-like peptide-1 receptor agonist plus basal insulin: The SIMPLE study.
To compare the efficacy and safety of a glucagon-like peptide-1 receptor agonist (GLP1RA) plus basal insulin versus basal-bolus insulin treatment in patients with very uncontrolled type 2 diabetes.. The SIMPLE study was a 6-month pragmatic, randomized, open-label trial testing the effectiveness of two approaches to treat patients with type 2 diabetes and HbA1c ≥10%. We randomized patients to detemir plus liraglutide or detemir plus aspart (before each meal). The primary endpoint was change in HbA1c; changes in body weight, insulin dose, hypoglycaemia and diabetes-related quality-of-life were secondary outcomes.. In patients with HbA1c ≥10% treatment with GLP1RA plus basal insulin, compared with basal-bolus insulin, resulted in better glycaemic control and body weight, lower insulin dosage and hypoglycaemia, and improved quality of life. This treatment strategy is an effective and safe alternative to a basal-bolus insulin regimen. Topics: Adult; Blood Glucose; Body Weight; Comparative Effectiveness Research; Diabetes Mellitus, Type 2; Drug Therapy, Combination; Female; Glucagon-Like Peptide 1; Glycated Hemoglobin; Humans; Hypoglycemia; Hypoglycemic Agents; Insulin Aspart; Insulin Detemir; Liraglutide; Male; Meals; Middle Aged; Treatment Outcome | 2019 |
Combined GLP-1, Oxyntomodulin, and Peptide YY Improves Body Weight and Glycemia in Obesity and Prediabetes/Type 2 Diabetes: A Randomized, Single-Blinded, Placebo-Controlled Study.
Roux-en-Y gastric bypass (RYGB) augments postprandial secretion of glucagon-like peptide 1 (GLP-1), oxyntomodulin (OXM), and peptide YY (PYY). Subcutaneous infusion of these hormones ("GOP"), mimicking postprandial levels, reduces energy intake. Our objective was to study the effects of GOP on glycemia and body weight when given for 4 weeks to patients with diabetes and obesity.. In this single-blinded mechanistic study, obese patients with prediabetes/diabetes were randomized to GOP (. GOP infusion improves glycemia and reduces body weight. It achieves superior glucose tolerance and reduced glucose variability compared with RYGB and VLCD. GOP is a viable alternative for the treatment of diabetes with favorable effects on body weight. Topics: Adult; Blood Glucose; Blood Glucose Self-Monitoring; Body Weight; Diabetes Mellitus, Type 2; Drug Therapy, Combination; Female; Glucagon-Like Peptide 1; Humans; Hypoglycemia; Infusions, Subcutaneous; Insulin; Male; Meals; Middle Aged; Obesity; Oxyntomodulin; Peptide YY; Postprandial Period; Prediabetic State; Single-Blind Method; Weight Loss | 2019 |
Locally delivered GLP-1 analogues liraglutide and exenatide enhance microvascular perfusion in individuals with and without type 2 diabetes.
Glucagon-like peptide-1 (GLP-1) analogues reduce the risk of macrovascular disease in diabetes; however, little is known about their microvascular effects. This research examined the microvascular actions of the GLP-1 analogues liraglutide and exenatide in individuals with and without type 2 diabetes (study 1). It also explored the involvement of the GLP-1 receptor (study 2) and the nitric oxide pathway in mediating the microvascular effects of the analogues.. Trial design: Studies 1 and 2 had a randomised, controlled, double-blind study design. Study 1 participants, intervention and methods: three participant groups were recruited: individuals with well-controlled type 2 diabetes, and obese and lean individuals without diabetes (21 participants per group). Liraglutide (0.06 mg), exenatide (0.5 μg) and saline (154 mmol/l NaCl; 0.9%) control were microinjected into separate sites in the dermis (forearm) in a randomised order, blinded to operator and participant. Skin microvascular perfusion was assessed by laser Doppler perfusion imaging. Outcomes were stabilised response (mean skin perfusion between 7.5 and 10 min post microinjection) and total response (AUC, normalised for baseline perfusion). Perfusion response to GLP-1 analogues was compared with saline within each group as well as between groups. Study 2 participants, intervention and methods: in healthy individuals (N = 16), liraglutide (0.06 mg) and saline microinjected sites were pretreated with saline or the GLP-1 receptor blocker, exendin-(9,39), in a randomised order, blinded to participant and operator. Outcomes were as above (stabilised response and total perfusion response). Perfusion response to liraglutide was compared between the saline and the exendin-(9,39) pretreated sites. In vitro study: the effects of liraglutide and exenatide on nitrate levels and endothelial nitric oxide synthase phosphorylation (activation) were examined using human microvascular endothelial cells.. Study 1 results: both analogues increased skin perfusion (stabilised response and total response) in all groups (n = 21 per group, p < 0.001), with the microvascular responses similar across groups (p ≥ 0.389). Study 2 results: liraglutide response (stabilised response and total response) was not influenced by pretreatment with exendin-(9,39) (70 nmol/l) (N = 15, one dataset excluded) (p ≥ 0.609). Liraglutide and exenatide increased nitrate production and endothelial nitric oxide synthase (eNOS) phosphorylation (p ≤ 0.020).. Liraglutide and exenatide increased skin microvascular perfusion in individuals with and without well-controlled diabetes, potentially mediated, at least in part, by NO.. ClinicalTrials.gov NCT01677104.. This work was supported by Diabetes UK (grant numbers: 09/0003955 and 12/0004600 [RW and JM Collins Legacy, Funded Studentship]). Topics: Adult; Aged; Aged, 80 and over; Diabetes Mellitus, Type 2; Exenatide; Female; Glucagon-Like Peptide 1; Hemodynamics; Humans; Linear Models; Liraglutide; Male; Microcirculation; Middle Aged | 2019 |
Improved treatment satisfaction in patients with type 2 diabetes treated with once-weekly semaglutide in the SUSTAIN trials.
To investigate treatment satisfaction with semaglutide, a once-weekly glucagon-like peptide-1 receptor agonist, versus placebo/active comparators in the SUSTAIN clinical trial programme.. In SUSTAIN 2-5 and 7, the Diabetes Treatment Satisfaction Questionnaire was used to evaluate patient-perceived treatment satisfaction, hyperglycaemia and hypoglycaemia. Post hoc subgroup analyses were conducted to explore the effects of gastrointestinal adverse events (GI AEs), weight loss (≥5%) or achieving glycaemic (HbA1c < 7%) targets on treatment satisfaction.. Overall treatment satisfaction increased from baseline to end of treatment with all treatments across trials. Improvements were significantly greater with semaglutide versus comparators/placebo in SUSTAIN 2-5 (all P < 0.05), and generally greater in patients who achieved versus did not achieve weight loss and glycaemic targets, often with greater improvements with semaglutide 1.0 mg versus comparator/placebo in both weight loss groups. In SUSTAIN 7, improvements in overall treatment satisfaction were generally similar between semaglutide and dulaglutide, irrespective of weight loss or glycaemic control. In SUSTAIN 7, changes in overall treatment satisfaction score were generally lower in patients with versus without GI AEs at week 16 (except dulaglutide 0.75 mg), but similar by week 40. Perceived hyperglycaemia was significantly reduced from baseline to end of treatment with semaglutide versus all comparators/placebo (all P < 0.05). No differences between treatments were observed for perceived hypoglycaemia.. Semaglutide was associated with significantly greater (SUSTAIN 2-5) or similar (SUSTAIN 7) improvements in overall treatment satisfaction versus comparators/placebo. Improvements in overall treatment satisfaction were generally greater in patients achieving versus not achieving treatment targets. Clinicaltrials.gov: NCT01930188 (SUSTAIN 2), NCT01885208 (SUSTAIN 3), NCT02128932 (SUSTAIN 4), NCT02305381 (SUSTAIN 5) and NCT02648204 (SUSTAIN 7). EudraCT: 2012-004827-19 (SUSTAIN 2), 2012-004826-92 (SUSTAIN 3), 2013-004392-12 (SUSTAIN 4), 2013-004502-26 (SUSTAIN 5) and 2014-005375-91 (SUSTAIN 7). Topics: Blood Glucose; Diabetes Mellitus, Type 2; Glucagon-Like Peptide 1; Glucagon-Like Peptides; Humans; Hypoglycemic Agents; Patient Satisfaction; Surveys and Questionnaires; Weight Loss | 2019 |
Effect of Oral Nutritional Supplements with Sucromalt and Isomaltulose versus Standard Formula on Glycaemic Index, Entero-Insular Axis Peptides and Subjective Appetite in Patients with Type 2 Diabetes: A Randomised Cross-Over Study.
Oral diabetes-specific nutritional supplements (ONS-D) induce favourable postprandial responses in subjects with type 2 diabetes (DM2), but they have not been correlated yet with incretin release and subjective appetite (SA). This randomised, double-blind, cross-over study compared postprandial effects of ONS-D with isomaltulose and sucromalt versus standard formula (ET) on glycaemic index (GI), insulin, glucose-dependent insulinotropic polypeptide (GIP), glucagon-like peptide 1 (GLP-1) and SA in 16 individuals with DM2. After overnight fasting, subjects consumed a portion of supplements containing 25 g of carbohydrates or reference food. Blood samples were collected at baseline and at 30, 60, 90, 120, 150 and 180 min; and SA sensations were assessed by a visual analogue scale on separate days. Glycaemic index values were low for ONS-D and intermediate for ET ( Topics: Administration, Oral; Appetite Regulation; Biomarkers; Blood Glucose; Cross-Over Studies; Diabetes Mellitus, Type 2; Dietary Supplements; Disaccharides; Double-Blind Method; Female; Fructose; Gastric Inhibitory Polypeptide; Glucagon-Like Peptide 1; Glycemic Index; Humans; Insulin; Isomaltose; Male; Middle Aged; Peptide Hormones; Time Factors; Treatment Outcome | 2019 |
The bile acid-sequestering resin sevelamer eliminates the acute GLP-1 stimulatory effect of endogenously released bile acids in patients with type 2 diabetes.
Discovery of the specific bile acid receptors farnesoid X receptor (FXR) and Takeda G protein-coupled receptor 5 (TGR5) in enteroendocrine L cells has prompted research focusing on the impact of bile acids on glucagon-like peptide-1 (GLP-1) secretion and glucose metabolism. The aim of the present study was to assess the GLP-1 secretory and gluco-metabolic effects of endogenously released bile, with and without concomitant administration of the bile acid-sequestering resin, sevelamer, in patients with type 2 diabetes.. We performed a randomized, placebo-controlled, double-blinded cross-over study including 15 metformin-treated patients with type 2 diabetes. During 4 experimental study days, either sevelamer 3200 mg or placebo in combination with intravenous infusion of cholecystokinin (CCK) (0.4 pmol sulfated CCK-8/kg/min) or saline was administered in randomized order. The primary endpoint was plasma GLP-1 excursions as measured by incremental area under the curve. Secondary endpoints included plasma responses of glucose, triglycerides, insulin, CCK, fibroblast growth factor-19 and 7α-hydroxy-4-cholesten-3-one (C4). In addition, gallbladder dynamics, gastric emptying, resting energy expenditure, appetite and ad libitum food intake were assessed.. CCK-mediated gallbladder emptying was demonstrated to elicit a significant induction of GLP-1 secretion compared to saline, whereas concomitant single-dose administration of the bile acid sequestrant sevelamer was shown to eliminate the acute bile acid-induced increase in plasma GLP-1 excursions.. Single-dose administration of sevelamer eliminated bile acid-mediated GLP-1 secretion in patients with type 2 diabetes, which could be explained by reduced bile acid stimulation of the basolaterally localized TGR5 on enteroendocrine L cells. Topics: Aged; Bile Acids and Salts; Chelating Agents; Cholagogues and Choleretics; Cross-Over Studies; Diabetes Mellitus, Type 2; Double-Blind Method; Drug Therapy, Combination; Enteroendocrine Cells; Female; Gallbladder Emptying; Gastric Emptying; Gastrointestinal Agents; Glucagon-Like Peptide 1; Humans; Hypoglycemic Agents; Infusions, Intravenous; Male; Metformin; Middle Aged; Sevelamer; Sincalide | 2018 |
Glucagon-Like Peptides 1 and 2 Are Involved in Satiety Modulation After Modified Biliopancreatic Diversion: Results of a Pilot Study.
This paper aimed to evaluate the influence of modified biliopancreatic diversion (BPD) on the levels of GLP-1 and GLP-2 and correlate them with satiety regulation.. This is a pilot prospective cohort study that evaluated six mildly obese individuals with type 2 diabetes mellitus, which underwent modified BPD and were followed-up for 12 months. Levels of GLP-1 and GLP-2 after a standard meal tolerance test were determined and correlated with satiety scores obtained by means of a visual analogue scale (VAS).. Modified BPD does not lead to significant changes in satiety evaluated by the VAS; different aspects of satiety regulation are correlated with the postprandial levels of GLP-1 (hunger feeling) and GLP-2 (satiation feeling and desire to eat) 1 year after modified BPD, signaling a specific postoperative gut hormone-related modulation of appetite. Topics: Adult; Appetite Regulation; Biliopancreatic Diversion; Diabetes Mellitus, Type 2; Female; Follow-Up Studies; Glucagon-Like Peptide 1; Glucagon-Like Peptide 2; Humans; Male; Middle Aged; Obesity, Morbid; Pilot Projects; Postoperative Period; Postprandial Period; Satiation | 2018 |
Modulation of GLP-1 Levels by a Genetic Variant That Regulates the Cardiovascular Effects of Intensive Glycemic Control in ACCORD.
A genome-wide association study in the Action to Control Cardiovascular Risk in Diabetes (ACCORD) trial identified two markers (rs57922 and rs9299870) that were significantly associated with cardiovascular mortality during intensive glycemic control and could potentially be used, when combined into a genetic risk score (GRS), to identify patients with diabetes likely to derive benefit from intensive control rather than harm. The aim of this study was to gain insights into the pathways involved in the modulatory effect of these variants.. Fasting levels of 65 biomarkers were measured at baseline and at 12 months of follow-up in the ACCORD-Memory in Diabetes (ACCORD-MIND) MRI substudy (. Differences in GLP-1 axis activation may mediate the modulatory effect of variant rs57922 on the cardiovascular response to intensive glycemic control. These findings highlight the importance of GLP-1 as a cardioprotective factor. Topics: Aged; Blood Glucose; Diabetes Mellitus, Type 2; Diabetic Angiopathies; Female; Genetic Predisposition to Disease; Genome-Wide Association Study; Genotype; Glucagon-Like Peptide 1; Humans; Hypoglycemic Agents; Male; Middle Aged; Polymorphism, Single Nucleotide; Risk Factors | 2018 |
Glycemic Control after Sleeve Gastrectomy and Roux-En-Y Gastric Bypass in Obese Subjects with Type 2 Diabetes Mellitus.
Roux-en-Y gastric bypass (LRYGB) has weight-independent effects on glycemia in obese type 2 diabetic patients, whereas sleeve gastrectomy (LSG) is less well characterized. This study aims to compare early weight-independent and later weight-dependent glycemic effects of LRYGB and LSG.. Eighteen LRYGB and 15 LSG patients were included in the study. Glucose, insulin, GLP-1, and GIP levels were monitored during a modified 30 g oral glucose tolerance test before surgery and 2 days, 3 weeks, and 12 months after surgery. Patients self-monitored glucose levels 2 weeks before and after surgery.. Postoperative fasting blood glucose decreased similarly in both groups (LRYGB vs. SG; baseline-8.1 ± 0.6 vs. 8.2 ± 0.4 mmol/l, 2 days-7.8 ± 0.5 vs. 7.4 ± 0.3 mmol/l, 3 weeks-6.6 ± 0.4 vs. 6.6 ± 0.3 mmol/l, respectively, P < 0.01 vs. baseline for both groups; 12 months-6.6 ± 0.4 vs. 5.9 ± 0.4, respectively, P < 0.05 for LRYGB and P < 0.001 for LSG vs. baseline, P = ns between the groups at all times). LSG, but not LRYGB, showed increased peak insulin levels 2 days postoperatively (mean ± SEM; LSG + 58 ± 14%, P < 0.01; LRYGB - 8 ± 17%, P = ns). GLP-1 levels increased similarly at 2 days, but were higher in LRYGB at 3 weeks (AUC; 7525 ± 1258 vs. 4779 ± 712 pmol × min, respectively, P < 0.05). GIP levels did not differ. Body mass index (BMI) decreased more after LRYGB than LSG (- 10.1 ± 0.9 vs. - 7.9 ± 0.5 kg/m. LRYGB and LSG show very similar effects on glycemic control, despite lower GLP-1 levels and inferior BMI decrease after LSG. Topics: Blood Glucose; Body Mass Index; Diabetes Mellitus, Type 2; Female; Follow-Up Studies; Gastrectomy; Gastric Bypass; Glucagon-Like Peptide 1; Humans; Insulin; Laparoscopy; Male; Middle Aged; Obesity; Postoperative Period; Sweden; Weight Loss | 2018 |
Comparing olive oil and C4-dietary oil, a prodrug for the GPR119 agonist, 2-oleoyl glycerol, less energy intake of the latter is needed to stimulate incretin hormone secretion in overweight subjects with type 2 diabetes.
After digestion, dietary triacylglycerol stimulates incretin release in humans, mainly through generation of 2-monoacylglycerol, an agonist for the intestinal G protein-coupled receptor 119 (GPR119). Enhanced incretin release may have beneficial metabolic effects. However, dietary fat may promote weight gain and should therefore be restricted in obesity. We designed C4-dietary oil (1,3-di-butyryl-2-oleoyl glycerol) as a 2-oleoyl glycerol (2-OG)-generating fat type, which would stimulate incretin release to the same extent while providing less calories than equimolar amounts of common triglycerides, e.g., olive oil.. We studied the effect over 180 min of (a) 19 g olive oil plus 200 g carrot, (b) 10.7 g C4 dietary oil plus 200 g carrot and (c) 200 g carrot, respectively, on plasma responses of gut and pancreatic hormones in 13 overweight patients with type 2 diabetes (T2D). Theoretically, both oil meals result in formation of 7.7 g 2-OG during digestion.. Both olive oil and C4-dietary oil resulted in greater postprandial (P ≤ 0.01) glucagon-like peptide 1 (GLP-1) and glucose-dependent insulinotropic polypeptide (GIP) responses (incremental area under curve (iAUC)): iAUC. C4-dietary oil enhanced secretion of GLP-1 and GIP to almost the same extent as olive oil, in spite of liberation of both 2-OG and oleic acid, which also may stimulate incretin secretion, from olive oil. Thus, C4-dietary oil is more effective as incretin releaser than olive oil per unit of energy and may be useful for dietary intervention. Topics: Aged; Area Under Curve; Diabetes Mellitus, Type 2; Dietary Fats, Unsaturated; Female; Gastric Inhibitory Polypeptide; Glucagon-Like Peptide 1; Glycerides; Glycerol; Humans; Incretins; Male; Meals; Middle Aged; Obesity; Oleic Acid; Olive Oil; Overweight; Postprandial Period; Prodrugs; Receptors, G-Protein-Coupled; Single-Blind Method; Triglycerides | 2018 |
Pre-Meal Effect of Whey Proteins on Metabolic Parameters in Subjects with and without Type 2 Diabetes: A Randomized, Crossover Trial.
Diabetic dyslipidemia with elevated postprandial triglyceride (TG) responses is characteristic in type 2 diabetes (T2D). Diet and meal timing can modify postprandial lipemia (PPL). The impact of a pre-meal of whey proteins (WP) on lipid metabolism is unidentified. We determined whether a WP pre-meal prior to a fat-rich meal influences TG and apolipoprotein B-48 (ApoB-48) responses differentially in patients with and without T2D. Two matched groups of 12 subjects with and without T2D accomplished an acute, randomized, cross-over trial. A pre-meal of WP (20 g) or water (control) was consumed 15 min before a fat-rich meal (supplemented with 20 g WP in case of water pre-meal). Postprandial responses were examined during a 360-min period. A WP pre-meal significantly increased postprandial concentrations of insulin ( Topics: Acetaminophen; Aged; Apolipoprotein B-48; Blood Glucose; Cross-Over Studies; Diabetes Mellitus, Type 2; Diet; Fatty Acids, Nonesterified; Female; Gastric Emptying; Gastric Inhibitory Polypeptide; Glucagon; Glucagon-Like Peptide 1; Glycated Hemoglobin; Humans; Insulin; Male; Meals; Middle Aged; Postprandial Period; Triglycerides; Whey Proteins | 2018 |
The effects of short-term continuous subcutaneous insulin infusion treatment on fasting glucagon-like peptide-1 concentrations in newly diagnosed type 2 diabetes.
Early short-term intensive insulin therapy in newly diagnosed type 2 diabetes patients shows benefit in glycemic control and β-cell function. Glucagon-like peptide-1 (GLP-1) plays an important role in glucose metabolism and development of type 2 diabetes. We did a study to observe the changes of GLP-1 and β-cell function after short-term continuous subcutaneous insulin infusion (CSII) treatment.. A total of 66 subjects were enrolled, including 30 normal glucose tolerance controls (NGT) and 36 patients with newly diagnosed type 2 diabetes between October 2015 and July 2016. Fasting plasma glucose (FPG), insulin, and GLP-1 were measured in each subject. The patients underwent CSII treatment for 2 weeks, and then FBG, insulin, and GLP-1 were measured. HOMA-IR and HOMA-B were then calculated.. All patients achieved target glycemic control in two weeks. HOMA-IR and HOMA-B improved significantly after intensive interventions (p < 0.05). The GLP-1 concentration increased significantly in patients after treatment (p < 0.05). When grouped according to bodyweight and age in all patients, the HOMA-IR changed significantly in overweight and old age subgroups, the HOMA-B increased significantly in normal weight, overweight and middle age subgroups, and the GLP-1 concentration also increased significantly in overweight and middle age subgroups respectively (p < 0.05).. Short-term CSII treatment can obtain glycemic control target and recover β-cell function and GLP-1 secretion in newly diagnosed type 2 diabetes patients. The overweight and middle-aged patients may get more benefit from this treatment. Topics: Adult; Aged; Blood Glucose; Diabetes Mellitus, Type 2; Drug Administration Schedule; Drug Delivery Systems; Fasting; Female; Glucagon-Like Peptide 1; Humans; Infusions, Subcutaneous; Insulin; Male; Middle Aged; Time Factors | 2018 |
Glucose-lowering effects and mechanisms of the bile acid-sequestering resin sevelamer.
Sevelamer, a non-absorbable amine-based resin used for treatment of hyperphosphataemia, has been demonstrated to have a marked bile acid-binding potential alongside beneficial effects on lipid and glucose metabolism. The aim of this study was to investigate the glucose-lowering effect and mechanism(s) of sevelamer in patients with type 2 diabetes.. In this double-blinded randomized controlled trial, we randomized 30 patients with type 2 diabetes to sevelamer (n = 20) or placebo (n = 10). Participants were subjected to standardized 4-hour liquid meal tests at baseline and after 7 days of treatment. The main outcome measure was plasma glucagon-like peptide-1 excursions as measured by area under the curve. In addition, blood was sampled for measurements of glucose, lipids, glucose-dependent insulinotropic polypeptide, C-peptide, glucagon, fibroblast growth factor-19, cholecystokinin and bile acids. Assessments of gastric emptying, resting energy expenditure and gut microbiota composition were performed.. Sevelamer elicited a significant placebo-corrected reduction in plasma glucose with concomitant reduced fibroblast growth factor-19 concentrations, increased de novo synthesis of bile acids, a shift towards a more hydrophilic bile acid pool and increased lipogenesis. No glucagon-like peptide-1-mediated effects on insulin, glucagon or gastric emptying were evident, which points to a limited contribution of this incretin hormone to the glucose-lowering effect of sevelamer. Furthermore, no sevelamer-mediated effects on gut microbiota composition or resting energy expenditure were observed.. Sevelamer reduced plasma glucose concentrations in patients with type 2 diabetes by mechanisms that seemed to involve decreased intestinal and hepatic bile acid-mediated farnesoid X receptor activation. Topics: Aged; Area Under Curve; Bile Acids and Salts; Blood Glucose; C-Peptide; Chelating Agents; Cholecystokinin; Cholesterol; Cholesterol, HDL; Cholesterol, LDL; Diabetes Mellitus, Type 2; Double-Blind Method; Energy Metabolism; Female; Fibroblast Growth Factors; Gastric Emptying; Gastric Inhibitory Polypeptide; Gastrointestinal Microbiome; Glucagon; Glucagon-Like Peptide 1; Humans; Male; Middle Aged; RNA, Ribosomal, 16S; Sequestering Agents; Sevelamer; Triglycerides | 2018 |
Gut bacteria selectively promoted by dietary fibers alleviate type 2 diabetes.
The gut microbiota benefits humans via short-chain fatty acid (SCFA) production from carbohydrate fermentation, and deficiency in SCFA production is associated with type 2 diabetes mellitus (T2DM). We conducted a randomized clinical study of specifically designed isoenergetic diets, together with fecal shotgun metagenomics, to show that a select group of SCFA-producing strains was promoted by dietary fibers and that most other potential producers were either diminished or unchanged in patients with T2DM. When the fiber-promoted SCFA producers were present in greater diversity and abundance, participants had better improvement in hemoglobin A1c levels, partly via increased glucagon-like peptide-1 production. Promotion of these positive responders diminished producers of metabolically detrimental compounds such as indole and hydrogen sulfide. Targeted restoration of these SCFA producers may present a novel ecological approach for managing T2DM. Topics: Adult; Aged; Bacteria; China; Diabetes Mellitus, Type 2; Diet; Dietary Fiber; Fatty Acids, Volatile; Feces; Female; Fermentation; Gastrointestinal Microbiome; Glucagon-Like Peptide 1; Glycated Hemoglobin; Humans; Hydrogen Sulfide; Indoles; Male; Metagenomics; Middle Aged | 2018 |
Interleukin-6 Delays Gastric Emptying in Humans with Direct Effects on Glycemic Control.
Gastric emptying is a critical regulator of postprandial glucose and delayed gastric emptying is an important mechanism of improved glycemic control achieved by short-acting glucagon-like peptide-1 (GLP-1) analogs in clinical practice. Here we report on a novel regulatory mechanism of gastric emptying in humans. We show that increasing interleukin (IL)-6 concentrations delays gastric emptying leading to reduced postprandial glycemia. IL-6 furthermore reduces insulin secretion in a GLP-1-dependent manner while effects on gastric emptying are GLP-1 independent. Inhibitory effects of IL-6 on gastric emptying were confirmed following exercise-induced increases in IL-6. Importantly, gastric- and insulin-reducing effects were maintained in individuals with type 2 diabetes. These data have clinical implications with respect to the use of IL-6 inhibition in autoimmune/inflammatory disease, and identify a novel target that could be exploited pharmacologically to delay gastric emptying and spare insulin, which may be beneficial for the beta cell in type 2 diabetes. Topics: Aged; Blood Glucose; Case-Control Studies; Diabetes Mellitus, Type 2; Double-Blind Method; Exercise; Gastric Emptying; Glucagon-Like Peptide 1; Humans; Hypoglycemia; Insulin; Insulin Secretion; Insulin-Secreting Cells; Interleukin-6; Male; Recombinant Proteins; Young Adult | 2018 |
MEDI0382, a GLP-1/glucagon receptor dual agonist, meets safety and tolerability endpoints in a single-dose, healthy-subject, randomized, Phase 1 study.
MEDI0382 is a balanced glucagon-like peptide-1/glucagon receptor dual agonist under development for the treatment of type 2 diabetes mellitus and non-alcoholic steatohepatitis. The primary objective was to assess the safety of MEDI0382 in healthy subjects.. In this placebo-controlled, double-blind, Phase 1 study, healthy subjects (aged 18-45 years) were randomized (3:1) to receive a single subcutaneous dose of MEDI0382 or placebo after ≥8 h of fasting. The study consisted of six cohorts that received study drug at 5 μg, 10 μg, 30 μg, 100 μg, 150 μg or 300 μg. The primary objective was safety and tolerability. Secondary endpoints included assessments of pharmacokinetics and immunogenicity. All subjects were followed for up to 28 days.. A total of 36 subjects received MEDI0382 (n = 6 per cohort) and 12 subjects received placebo (n = 2 per cohort). Treatment-emergent adverse events (TEAEs) occurred more frequently with MEDI0382 vs. placebo, which was mostly due to an increased occurrence at MEDI0382 doses ≥150 μg. All TEAEs were mild or moderate in severity. The most common TEAEs were vomiting, nausea and dizziness. There appeared to be a dose-dependent increase in heart rate with MEDI0382 treatment. MEDI0382 showed linear pharmacokinetic profile (time to maximum plasma concentration: 4.50-9.00 h; elimination half-life: 9.54-12.07 h). No immunogenicity was observed in the study.. In this single-dose, Phase 1 study in healthy subjects, the safety and pharmacokinetic profiles of MEDI0382 support once-daily dosing and further clinical development of MEDI0382. Topics: Adult; Diabetes Mellitus, Type 2; Dose-Response Relationship, Drug; Double-Blind Method; Drug Administration Schedule; Female; Glucagon-Like Peptide 1; Half-Life; Healthy Volunteers; Humans; Hypoglycemic Agents; Injections, Subcutaneous; Male; Peptides; Receptors, Glucagon; Young Adult | 2018 |
Rate of appearance of amino acids after a meal regulates insulin and glucagon secretion in patients with type 2 diabetes: a randomized clinical trial.
Meal composition regulates the postprandial response of pancreatic and gastrointestinal hormones and plays an important role in patients with type 2 diabetes (T2D). Proteins have glucagon and insulinotropic effects, which may differ depending on amino acid composition, form of intake, and rate of digestibility and absorption.. The aim of this study was to test effects of isolated pea protein-based (PP) compared with casein protein-based (CP) meals differing in amino acid compositions on endocrine responses to meal tolerance tests (MTTs) in patients with T2D.. Thirty-seven individuals with T2D [mean ± SD age: 64 ± 6 y; mean ± SD body mass index (kg/m2): 30.2 ± 3.6; mean ± SD glycated hemoglobin: 7.0% ± 0.6%] were randomly assigned to receive either high-animal-protein (∼80% of total protein) or high-plant-protein (∼72% of total protein) diets (30% of energy from protein, 40% of energy from carbohydrate, 30% of energy from fat) for 6 wk. MTTs were performed at study onset and after 6 wk. Participants received standardized high-protein (30% of energy) meals 2 times/d containing either CP-rich (∼85% wt:wt) or PP-rich (∼95% wt:wt) foods.. The CP and PP meals produced differences in insulin, C-peptide, glucagon, and glucose-dependent insulinotropic peptide (GIP) release. Total areas under the curve after CP were significantly lower than after the PP lunch by 40% for insulin and 23% for glucagon. Indexes of insulin sensitivity and secretion were significantly improved for the second CP MTT. This was accompanied by differential rates of appearance of amino acids. The ingestion of PP resulted in significant increases in amino acids after both meals, with a decline between meals. By contrast, CP intake resulted in increases in most amino acids after breakfast, which remained elevated but did not increase further after lunch.. PP elicits greater postprandial increases in glucagon than does CP and consequently requires higher insulin to control glucose metabolism, which appears to be related to the rate of amino acid appearance. The metabolic impact of protein quality could be used as a strategy to lower insulin needs in patients with T2D. This trial was registered at www.clinicaltrials.gov as NCT02402985. Topics: Aged; Amino Acids; Blood Glucose; Diabetes Mellitus, Type 2; Diet, High-Protein; Female; Gastric Inhibitory Polypeptide; Glucagon; Glucagon-Like Peptide 1; Humans; Insulin; Male; Middle Aged | 2018 |
Harmony Outcomes: A randomized, double-blind, placebo-controlled trial of the effect of albiglutide on major cardiovascular events in patients with type 2 diabetes mellitus-Rationale, design, and baseline characteristics.
Albiglutide is a long-acting glucagon-like peptide-1 receptor agonist that improves glycemic control in patients with type 2 diabetes mellitus (T2DM). Harmony Outcomes is a randomized, double-blind, placebo-controlled trial of the effect of albiglutide on major adverse cardiovascular (CV) events in patients with T2DM and established CV disease.. The trial was designed to recruit 9,400 patients aged ≥40 years with T2DM, prior atherosclerotic CV disease, and suboptimal glycemic control. Participants were assigned in a 1:1 ratio to albiglutide 30 mg (potentially increasing to 50 mg) or matching placebo administered once weekly by subcutaneous injection. The trial will continue until ≥611 confirmed primary outcome events (CV death, myocardial infarction, or stroke) occur over a median follow-up of at least 1.5 years.. A total of 9,463 patients were enrolled at 611 sites in 28 countries between July 2015 and December 2016. The mean age was 64.1 years; duration of T2DM, 13.8 years; and glycated hemoglobin, 8.7%. The percentage of patients with prior coronary artery disease was 70.5%; peripheral arterial disease, 25.0%; stroke, 17.7%; heart failure, 20.2%; and chronic kidney disease, 22.6%.. Harmony Outcomes will assess the CV safety of albiglutide in patients with T2DM and CV disease. Trials of other agents in the glucagon-like peptide-1 receptor agonist class have shown CV benefit for only some of these medications, possibly due to differences in trial design or instead due to differences in drug structure or metabolism. Harmony Outcomes will provide information critical to our understanding of this heterogenous class of glucose-lowering agents. Topics: Adult; Aged; Blood Glucose; Cardiovascular Diseases; Diabetes Mellitus, Type 2; Double-Blind Method; Female; Follow-Up Studies; Glucagon-Like Peptide 1; Glycated Hemoglobin; Humans; Hypoglycemic Agents; Incidence; Incretins; Italy; Male; Middle Aged; Ontario; Survival Rate; Treatment Outcome; United Kingdom; United States | 2018 |
Predictive factors of efficacy of combination therapy with basal insulin and liraglutide in type 2 diabetes when switched from longstanding basal-bolus insulin: Association between the responses of β- and α-cells to GLP-1 stimulation and the glycaemic con
To evaluate the glycaemic control of combination therapy with basal insulin and liraglutide, and to explore the factors predictive of efficacy in patients with type 2 diabetes when switched from longstanding basal-bolus insulin therapy.. We studied 41 patients who switched from basal-bolus insulin therapy of more than 3 years to basal insulin/liraglutide combination therapy. Glycaemic control was evaluated at 6 months after switching therapy and used to subdivide the patients into good-responders (HbA1c <7.0% or 1.0% decrease) and poor-responders (the rest of participants). To evaluate the glucose-dependent insulin/glucagon responses without/with liraglutide, a 75-g oral glucose tolerance test (OGTT) was performed twice, before (1st-OGTT) and 2-days after (2nd-OGTT) liraglutide administration.. Twenty-eight patients (68.3%) were identified as good-responders. No differences were found in baseline characteristics including insulin/glucagon responses during 1st-OGTT between the groups. 2nd-OGTT revealed that paradoxical hyperglucagonemia were significantly improved in both groups, but significant increases in insulin secretory response were observed only in good-responders. Logistic regression analyses revealed that the improvement of the insulin-response during 2nd-OGTT compared to that during 1st-OGTT is associated with the good-responder.. Enhancement of glucose-dependent insulin-response under liraglutide administration is a potential predictor of long-term glycaemic control after switching the therapies. Topics: Aged; Blood Glucose; Diabetes Mellitus, Type 2; Drug Combinations; Female; Glucagon-Like Peptide 1; Glucagon-Secreting Cells; Glucose Tolerance Test; Glycated Hemoglobin; Glycemic Index; Humans; Hypoglycemic Agents; Insulin; Insulin-Secreting Cells; Liraglutide; Male; Middle Aged; Prospective Studies | 2018 |
Successful treatment of prediabetes in clinical practice using physiological assessment (STOP DIABETES).
Of the 84 million American adults with prediabetes, over 5 to 7 years, about 28 million progress to type 2 diabetes. We aimed to assess whether a real-world, pathophysiology-based, therapeutic approach could prevent development of type 2 diabetes in high-risk individuals.. We did a retrospective observational study of people at increased risk of type 2 diabetes from a community practice in southern California, USA. Participants had an oral glucose tolerance test and were assigned a risk stratification on the basis of presence and severity of insulin resistance, impaired β-cell function, and glycaemia (ie, 1-h plasma glucose concentration of more than 8·6 mmol/L during an oral glucose tolerance test). Treatment was recommended on the basis of risk: metformin, pioglitazone, glucagon-like peptide-1 (GLP-1) receptor agonist, and lifestyle therapy for participants at high risk of diabetes, and metformin, pioglitazone, and lifestyle therapy for those at intermediate risk. Individuals who refused pharmacological therapy were assigned to lifestyle therapy only. Participants were followed up every 6 months and oral glucose tolerance tests were repeated at 6 months and subsequently every 2 years or sooner. The primary outcome of our analysis was incidence of type 2 diabetes according to the American Diabetes Association criteria, within the study period (2009-16). This study is registered with ClinicalTrials.gov, number NCT03308773.. Between Jan 1, 2009 and Dec 31, 2016, we assessed 1769 people at increased risk of diabetes, of which 747 (42%) were identified at high or intermediate risk and were recommended pharmacological treatment. Of 422 participants analysed, 28 (7%) progressed to type 2 diabetes (seven [5%] of 141 participants who received metformin, pioglitazone, and lifestyle therapy, none [0%] of 81 who received metformin, pioglitazone, GLP-1 receptor agonist, and lifestyle therapy, and 21 [11%] of 200 who received lifestyle therapy only) after mean follow-up of 32·09 months (SEM 1·24). Compared with participants who received lifestyle therapy only, the adjusted hazard ratio for progression to type 2 diabetes was 0·29 (95% CI 0·11-0·78, p=0·0009) in participants who received metformin and pioglitazone, and 0·12 (95% CI 0·02-0·94, p=0·04) in participants who received metformin, pioglitazone, and GLP-1 receptor agonist. Improved β-cell function was the strongest predictor of type 2 diabetes prevention.. Progression to type 2 diabetes in people at high risk of diabetes can be markedly reduced with interventions designed to correct underlying pathophysiological disturbances (ie, impaired insulin secretion and resistance) in a real-world setting.. None. Topics: Diabetes Mellitus, Type 2; Female; Glucagon-Like Peptide 1; Glucose Tolerance Test; Humans; Hypoglycemic Agents; Male; Metformin; Middle Aged; Pioglitazone; Prediabetic State; Retrospective Studies; Risk Factors; Risk Reduction Behavior; Treatment Outcome | 2018 |
Albiglutide and cardiovascular outcomes in patients with type 2 diabetes and cardiovascular disease (Harmony Outcomes): a double-blind, randomised placebo-controlled trial.
Glucagon-like peptide 1 receptor agonists differ in chemical structure, duration of action, and in their effects on clinical outcomes. The cardiovascular effects of once-weekly albiglutide in type 2 diabetes are unknown. We aimed to determine the safety and efficacy of albiglutide in preventing cardiovascular death, myocardial infarction, or stroke.. We did a double-blind, randomised, placebo-controlled trial in 610 sites across 28 countries. We randomly assigned patients aged 40 years and older with type 2 diabetes and cardiovascular disease (at a 1:1 ratio) to groups that either received a subcutaneous injection of albiglutide (30-50 mg, based on glycaemic response and tolerability) or of a matched volume of placebo once a week, in addition to their standard care. Investigators used an interactive voice or web response system to obtain treatment assignment, and patients and all study investigators were masked to their treatment allocation. We hypothesised that albiglutide would be non-inferior to placebo for the primary outcome of the first occurrence of cardiovascular death, myocardial infarction, or stroke, which was assessed in the intention-to-treat population. If non-inferiority was confirmed by an upper limit of the 95% CI for a hazard ratio of less than 1·30, closed testing for superiority was prespecified. This study is registered with ClinicalTrials.gov, number NCT02465515.. Patients were screened between July 1, 2015, and Nov 24, 2016. 10 793 patients were screened and 9463 participants were enrolled and randomly assigned to groups: 4731 patients were assigned to receive albiglutide and 4732 patients to receive placebo. On Nov 8, 2017, it was determined that 611 primary endpoints and a median follow-up of at least 1·5 years had accrued, and participants returned for a final visit and discontinuation from study treatment; the last patient visit was on March 12, 2018. These 9463 patients, the intention-to-treat population, were evaluated for a median duration of 1·6 years and were assessed for the primary outcome. The primary composite outcome occurred in 338 (7%) of 4731 patients at an incidence rate of 4·6 events per 100 person-years in the albiglutide group and in 428 (9%) of 4732 patients at an incidence rate of 5·9 events per 100 person-years in the placebo group (hazard ratio 0·78, 95% CI 0·68-0·90), which indicated that albiglutide was superior to placebo (p<0·0001 for non-inferiority; p=0·0006 for superiority). The incidence of acute pancreatitis (ten patients in the albiglutide group and seven patients in the placebo group), pancreatic cancer (six patients in the albiglutide group and five patients in the placebo group), medullary thyroid carcinoma (zero patients in both groups), and other serious adverse events did not differ between the two groups. There were three (<1%) deaths in the placebo group that were assessed by investigators, who were masked to study drug assignment, to be treatment-related and two (<1%) deaths in the albiglutide group.. In patients with type 2 diabetes and cardiovascular disease, albiglutide was superior to placebo with respect to major adverse cardiovascular events. Evidence-based glucagon-like peptide 1 receptor agonists should therefore be considered as part of a comprehensive strategy to reduce the risk of cardiovascular events in patients with type 2 diabetes.. GlaxoSmithKline. Topics: Adult; Aged; Cardiovascular Diseases; Diabetes Mellitus, Type 2; Double-Blind Method; Drug Administration Schedule; Female; Glucagon-Like Peptide 1; Humans; Hypoglycemic Agents; Injections, Subcutaneous; Kaplan-Meier Estimate; Male; Middle Aged; Myocardial Infarction; Stroke; Treatment Outcome | 2018 |
Metformin-induced glucagon-like peptide-1 secretion contributes to the actions of metformin in type 2 diabetes.
Metformin reduces plasma glucose and has been shown to increase glucagon-like peptide 1 (GLP-1) secretion. Whether this is a direct action of metformin on GLP-1 release, and whether some of the glucose-lowering effect of metformin occurs due to GLP-1 release, is unknown. The current study investigated metformin-induced GLP-1 secretion and its contribution to the overall glucose-lowering effect of metformin and underlying mechanisms in patients with type 2 diabetes.. Twelve patients with type 2 diabetes were included in this placebo-controlled, double-blinded study. On 4 separate days, the patients received metformin (1,500 mg) or placebo suspended in a liquid meal, with subsequent i.v. infusion of the GLP-1 receptor antagonist exendin9-39 (Ex9-39) or saline. During 240 minutes, blood was sampled. The direct effect of metformin on GLP-1 secretion was tested ex vivo in human ileal and colonic tissue with and without dorsomorphin-induced inhibiting of the AMPK activity.. Metformin increased postprandial GLP-1 secretion compared with placebo (P = 0.014), and the postprandial glucose excursions were significantly smaller after metformin + saline compared with metformin + Ex9-39 (P = 0.004). Ex vivo metformin acutely increased GLP-1 secretion (colonic tissue, P < 0.01; ileal tissue, P < 0.05), but the effect was abolished by inhibition of AMPK activity.. Metformin has a direct and AMPK-dependent effect on GLP-1-secreting L cells and increases postprandial GLP-1 secretion, which seems to contribute to metformin's glucose-lowering effect and mode of action.. NCT02050074 (https://clinicaltrials.gov/ct2/show/NCT02050074).. This study received grants from the A.P. Møller Foundation, the Novo Nordisk Foundation, the Danish Medical Association research grant, the Australian Research Council, the National Health and Medical Research Council, and Pfizer Inc. Topics: Adult; Aged; Aged, 80 and over; Australia; Blood Glucose; Diabetes Mellitus, Type 2; Double-Blind Method; Female; Glucagon-Like Peptide 1; Humans; Male; Metformin; Middle Aged; Postprandial Period | 2018 |
Pharmacokinetics and Tolerability of a Single Dose of Semaglutide, a Human Glucagon-Like Peptide-1 Analog, in Subjects With and Without Renal Impairment.
The pharmacokinetics and tolerability of semaglutide, a once-weekly human glucagon-like peptide-1 analog in development for the treatment of type 2 diabetes mellitus, were investigated in subjects with/without renal impairment (RI).. Fifty-six subjects, categorized into renal function groups [normal, mild, moderate, severe, and end-stage renal disease (ESRD)], received a single subcutaneous dose of semaglutide 0.5 mg. Semaglutide plasma concentrations were assessed ≤480 h post-dose; the primary endpoint was the area under the plasma concentration-time curve from time zero to infinity.. Semaglutide exposure in subjects with mild/moderate RI and ESRD was similar to that in subjects with normal renal function. In subjects with severe RI, the mean exposure of semaglutide was 22% higher than in subjects with normal renal function, and the 95% confidence interval (1.02-1.47) for the ratio exceeded the pre-specified limits (0.70-1.43). When adjusted for differences in sex, age, and body weight between the groups, all comparisons were within the pre-specified clinically relevant limits. Across RI groups there was no relationship between creatinine clearance (CL. When adjusted for differences in sex, age, and body weight, semaglutide exposure was similar between subjects with RI and subjects with normal renal function. Semaglutide (0.5 mg) was well-tolerated. Dose adjustment may not be warranted for subjects with RI. CLINICALTRIALS.. NCT00833716. Topics: Adolescent; Adult; Aged; Diabetes Mellitus, Type 2; Female; Glucagon-Like Peptide 1; Glucagon-Like Peptides; Humans; Hypoglycemic Agents; Male; Middle Aged; Renal Insufficiency; Young Adult | 2017 |
The effect of meal frequency in a reduced-energy regimen on the gastrointestinal and appetite hormones in patients with type 2 diabetes: A randomised crossover study.
Appetite and gastrointestinal hormones (GIHs) participate in energy homeostasis, feeding behavior and regulation of body weight. We demonstrated previously the superior effect of a hypocaloric diet regimen with lower meal frequency (B2) on body weight, hepatic fat content, insulin sensitivity and feelings of hunger compared to the same diet divided into six smaller meals a day (A6). Studies with isoenergetic diet regimens indicate that lower meal frequency should also have an effect on fasting and postprandial responses of GIHs. The aim of this secondary analysis was to explore the effect of two hypocaloric diet regimens on fasting levels of appetite and GIHs and on their postprandial responses after a standard meal. It was hypothesized that lower meal frequency in a reduced-energy regimen leading to greater body weight reduction and reduced hunger would be associated with decreased plasma concentrations of GIHs: gastric inhibitory peptide (GIP), glucagon-like peptide-1(GLP-1), peptide YY(PYY), pancreatic polypeptide (PP) and leptin and increased plasma concentration of ghrelin. The postprandial response of satiety hormones (GLP-1, PYY and PP) and postprandial suppression of ghrelin will be improved.. In a randomized crossover study, 54 patients suffering from type 2 diabetes (T2D) underwent both regimens. The concentrations of GLP-1, GIP, PP, PYY, amylin, leptin and ghrelin were determined using multiplex immunoanalyses.. Fasting leptin and GIP decreased in response to both regimens with no difference between the treatments (p = 0.37 and p = 0.83, respectively). Fasting ghrelin decreased in A6 and increased in B2 (with difference between regimens p = 0.023). Fasting PP increased in B2with no significant difference between regimens (p = 0.17). Neither GLP-1 nor PYY did change in either regimen. The decrease in body weight correlated negatively with changes in fasting ghrelin (r = -0.4, p<0.043) and the postprandial reduction of ghrelin correlated positively with its fasting level (r = 0.9, p<0.001). The postprandial responses of GIHs and appetite hormones were similar after both diet regimens.. Both hypocaloric diet regimens reduced fasting leptin and GIP and postprandial response of GIP comparably. The postprandial responses of GIHs and appetite hormones were similar after both diet regimens. Eating only breakfast and lunch increased fasting plasma ghrelin more than the same caloric restriction split into six meals. The changes in fasting ghrelin correlated negatively with the decrease in body weight. These results suggest that for type 2 diabetic patients on a hypocaloric diet, eating larger breakfast and lunch may be more efficient than six smaller meals during the day. Topics: Adult; Aged; Body Weight; Caloric Restriction; Cross-Over Studies; Diabetes Mellitus, Type 2; Female; Gastric Inhibitory Polypeptide; Ghrelin; Glucagon-Like Peptide 1; Humans; Hunger; Insulin Resistance; Leptin; Male; Meals; Middle Aged; Pancreatic Polypeptide; Peptide YY; Time Factors; Treatment Outcome | 2017 |
Effect of GLP-1 and GIP on C-peptide secretion after glucagon or mixed meal tests: Significance in assessing B-cell function in diabetes.
The aim of the study was to investigate the different B-cell responses after a glucagon stimulation test (GST) versus mixed meal tolerance test (MMTT).. We conducted GST and MMTT in 10 healthy people (aged 25-40 years) and measured C-peptide, gastric inhibitory peptide (GIP) and glucagon-like peptide-1 (GLP-1) at different time points after the administration of 1 mg i.v. glucagon for GST or a liquid mixed meal for MMTT.. The GST stimulated C-peptide showed a mean increase of 147.1%, whereas the mean increase of MMTT stimulated C-peptide was 99.82% (Δincrease = 47.2%). Maximum C-peptide level reached with the MMTT was greater than that obtained with the GST (C-pept max MMTT = 2.35 nmol/L vs C-pep max GST = 1.9 nmol/L). A positive and linear correlation was found between the GST incremental area under the curve C-peptide and the MMTT incremental area under the curve C-peptide (r = 0.618, P = .05). After GST, there was no increment of GIP and glucagon like peptide-1 levels compared to baseline levels. A positive and linear correlation between GIP and C-peptide levels was observed only for the MMTT (r = 0.922, P = .008) indicating that in the GST, the C-peptide response is independent of the incretin axis response.. Although the 2 stimulation tests may elicit a similar response in C-peptide secretion, B-cell response to MMTT depends on a functionally normal incretin axis. These results may have implications when investigating the B-cell response in people with diabetes and for studies in which stimulated C-peptide secretion is used as primary or secondary outcome for response to therapy. Topics: Adult; C-Peptide; Cross-Over Studies; Diabetes Mellitus, Type 2; Diagnostic Techniques, Endocrine; Eating; Female; Gastric Inhibitory Polypeptide; Glucagon; Glucagon-Like Peptide 1; Humans; Insulin-Secreting Cells; Male; Meals; Stimulation, Chemical | 2017 |
Predictive Value of Gut Peptides in T2D Remission: Randomized Controlled Trial Comparing Metabolic Gastric Bypass, Sleeve Gastrectomy and Greater Curvature Plication.
Our aim was to determine the predictive value of gut hormone changes for the improvement of type 2 diabetes (T2D) following metabolic Roux-en-Y gastric bypass (mRYGB), sleeve gastrectomy (SG), and greater curvature plication (GCP) in a randomized controlled trial. Contradictory results have been obtained regarding the role of gastrointestinal hormones (in particular GLP-1) in beneficial metabolic bariatric surgery outcomes.. Forty-five patients with T2D (mean BMI 39.4 ± 1.9 kg/m. Twelve months after surgery, total weight loss percentage was higher and HbA1c lower in the mRYGB group than in the SG and GCP groups (-35.2 ± 8.1 and 5.1 ± 0.6% vs. -27.8 ± 5.4 and 6.2 ± 0.8% vs. -20.5 ± 6.8 and 6.6 ± 1.3%; p = 0.007 and p < 0.001, respectively). Moreover, GLP-1 AUC at months 1 and 12 was greater and T2D remission was higher in mRYGB (80 vs. 53.3 vs. 20%, p < 0.001). Insulin treatment (odds ratio (OR) 0.025, p = 0.018) and the increase in GLP-1 AUC from baseline to month 1 (OR 1.021, p = 0.013) were associated with T2D remission.. mRYGB achieves a superior rate of weight loss and T2D remission at month 12. Enhanced GLP-1 secretion 1 month after surgery was a determinant of glucose metabolism improvement. Registration number ( http://www.clinicaltrials.gov ): NCT14104758. Topics: Adult; Diabetes Mellitus, Type 2; Female; Gastrectomy; Gastric Bypass; Gastrointestinal Hormones; Gastroplasty; Glucagon-Like Peptide 1; Humans; Male; Middle Aged; Obesity, Morbid; Remission Induction; Stomach; Weight Loss | 2017 |
Once weekly glucagon-like peptide-1 receptor agonist albiglutide vs. prandial insulin added to basal insulin in patients with type 2 diabetes mellitus: Results over 52 weeks.
We have previously reported that once-weekly albiglutide was noninferior to thrice-daily lispro for glycemic lowering, with decreased weight and risk of hypoglycemia, in patients inadequately controlled on basal insulin over 26 weeks. Findings after 52 weeks reveal similar responses to albiglutide as an add-on to insulin glargine. Topics: Diabetes Mellitus, Type 2; Drug Administration Schedule; Drug Monitoring; Drug Resistance; Drug Therapy, Combination; Glucagon-Like Peptide 1; Glucagon-Like Peptide-1 Receptor; Glycated Hemoglobin; Humans; Hyperglycemia; Hypoglycemia; Hypoglycemic Agents; Incidence; Incretins; Insulin Glargine; Insulin Lispro; Meals; Risk; Weight Gain; Weight Loss | 2017 |
Surgical and Advanced Medical Therapy for the Treatment of Type 2 Diabetes in Class I Obese Patients: a Short-Term Outcome.
Bariatric surgery, incretin-based therapy (glucagon-like peptide-1 analogues), and sodium-glucose co-transporter 2 (SGLT2) inhibitors have antidiabetic properties in morbidly obese patients. However, their comparative efficacy in treating type 2 diabetes mellitus (T2DM) in class I obese patients specifically in Indian has not been studied yet. This study evaluates and compares the efficacy and side effect of surgical and advanced medical management of T2DM in class I obese patients.. T2DM patients with body mass index ranging from 30 to 35 kg/m. There was statistically significant lowering of HbA1c and FPG after 12 months in all the three groups. However, this lowering was clinically insignificant in GLP-1 and SGLT2 groups. There was also improvement in lipid profile values in all the three groups with significantly higher percentage change in bariatric surgery group when compared to other modalities.. Bariatric surgery is a safe and effective procedure to treat T2DM in class I obese patients. It is also superior to advance medical treatment modalities such as GLP-1 analogues and SGLT2 inhibitors. Topics: Adult; Bariatric Surgery; Body Mass Index; Combined Modality Therapy; Diabetes Mellitus, Type 2; Female; Glucagon-Like Peptide 1; Humans; Hypoglycemic Agents; Incretins; Male; Middle Aged; Obesity; Sodium-Glucose Transporter 2; Sodium-Glucose Transporter 2 Inhibitors; Treatment Outcome | 2017 |
Three-year data from 5 HARMONY phase 3 clinical trials of albiglutide in type 2 diabetes mellitus: Long-term efficacy with or without rescue therapy.
Diabetes therapies that provide durable glycaemic control for people with type 2 diabetes mellitus (T2DM) are needed. We present efficacy results of albiglutide, a glucagon-like peptide-1 receptor agonist, in people with T2DM over a 3-year period.. Five of the 8 HARMONY phase 3 trials, comparing albiglutide with other therapies or placebo across a spectrum of clinical care, lasted for a preplanned 3years. Participants with uncontrolled hyperglycaemia who met predetermined criteria could receive rescue medication. The ability to remain on study medication without needing additional rescue was an efficacy measure. Glycaemic measures and body weight were analysed in 2 populations: those who remained rescue-free and all participants.. Participants (n=3132) were randomised to albiglutide or comparator. A greater proportion of participants who received albiglutide remained rescue-free (55-71%) compared with placebo (35-51%; p<0.001 to p=0.002). The proportion of rescue-free participants with albiglutide did not differ from glimepiride or insulin glargine, was higher than with sitagliptin (p=0.013), and lower than with pioglitazone (p=0.045). At 3years, albiglutide was associated with clinically significant reductions in hyperglycaemia (eg, rescue-free participants: HbA1c -0.52% [SE0.11] to -0.98% [0.12]; -5.7mmol/mol [1.2] to -10.7mmol/mol [1.3] and all participants: HbA1c -0.29% [0.11] to-0.92% [0.13]; -3.2mmol/mol [1.2] to -10.1mmol/mol [1.4]). Albiglutide was also associated with modest reductions in body weight vs pioglitazone, glimepiride, and insulin glargine, which were associated with weight gain.. These 3-year efficacy data support long-term use of albiglutide in the management of people with T2DM. ClinicalTrials.gov NCT00849056, NCT00849017, NCT00838903, NCT00838916, NCT00839527. Topics: Blood Glucose; Body Weight; Diabetes Mellitus, Type 2; Drug Therapy, Combination; Female; Glucagon-Like Peptide 1; Glucagon-Like Peptide-1 Receptor; Glycated Hemoglobin; Humans; Hyperglycemia; Hypoglycemic Agents; Insulin Glargine; Male; Pioglitazone; Sitagliptin Phosphate; Sulfonylurea Compounds; Thiazolidinediones; Treatment Outcome | 2017 |
Pharmacodynamics, pharmacokinetics and safety of multiple ascending doses of the novel dual glucose-dependent insulinotropic polypeptide/glucagon-like peptide-1 agonist RG7697 in people with type 2 diabetes mellitus.
To investigate the pharmacodynamics, pharmacokinetics and safety of multiple ascending doses of RG7697, a dual glucose-dependent insulinotropic polypeptide/glucagon-like peptide-1 agonist, in patients with type 2 diabetes mellitus (T2D).. A total of 56 patients with T2D received once-daily subcutaneous (s.c.) injection of RG7697 (0.25-2.5 mg) or placebo for 14 days in a randomized, double-blind, dose-escalation study. Adverse events (AEs), vital signs, ECGs and routine laboratory variables were intensively monitored. Drug concentrations, fasting glycaemic variables, 24-hour glucose profiles, glycated haemoglobin (HbA1c) and antibody formation were measured. Several meal tolerance and gastric emptying tests were performed during the study.. Daily s.c. injections of RG7697 were well tolerated by the majority of participants with T2D. The most frequently reported AEs with RG7697 were diarrhoea, nausea and decreased appetite. Asymptomatic events of hypoglycaemia were relatively uniformly distributed across dose groups including placebo. Pharmacokinetic steady-state was achieved within 1 week. Meaningful reductions in fasting, postprandial and 24-hour plasma glucose profile were observed at doses ≥0.75 mg, and were associated with numerical decreases in HbA1c (-0.67% [2.5-mg dose] vs -0.21% [placebo]). Decrease in postprandial insulin at doses ≥1.1 mg suggested improvement in insulin sensitivity. Minimum delay in gastric emptying and body weight reductions numerically greater than placebo (- 3.0 kg vs -0.9 kg) were seen at the highest dose of 2.5 mg.. Daily doses of RG7697 for 2 weeks were well tolerated by the majority of patients with T2D. Pharmacokinetic data supported once-daily dosing and pharmacodynamic effect displayed dose-dependent reductions in fasting and postprandial plasma glucose, without increasing the risk of hypoglycaemia. Topics: Adult; Aged; Blood Glucose; Diabetes Mellitus, Type 2; Dose-Response Relationship, Drug; Double-Blind Method; Drugs, Investigational; Female; Gastric Inhibitory Polypeptide; Glucagon-Like Peptide 1; Humans; Hypoglycemic Agents; Male; Middle Aged | 2017 |
Pharmacodynamics, pharmacokinetics, safety and tolerability of the novel dual glucose-dependent insulinotropic polypeptide/glucagon-like peptide-1 agonist RG7697 after single subcutaneous administration in healthy subjects.
To evaluate the pharmacodynamics, pharmacokinetics and safety of single subcutaneous (s.c.) injection of ascending doses of RG7697, a dual glucose-dependent insulinotropic polypeptide/glucagon-like peptide-1 agonist, in healthy subjects.. A total of 51 healthy volunteers were enrolled in this double-blind, placebo-controlled study investigating RG7697 doses ranging from 0.03 to 5 mg. Adverse events (AEs) were monitored and drug concentrations, fasting glycaemic variables, vital signs, ECG, antibody formation and routine laboratory variables were assessed. A meal tolerance test (MTT) was performed at the same time on day -1 (baseline) and day 1.. Single s.c. injections of RG7697 up to 3.6 mg were generally well tolerated. Evidence of glycaemic effect and pharmacokinetic profiles consistent with once-daily dosing render this drug candidate suitable to be further tested in multiple-dose clinical trials in patients with type 2 diabetes. Topics: Adolescent; Adult; Blood Glucose; Diabetes Mellitus, Type 2; Dose-Response Relationship, Drug; Double-Blind Method; Female; Gastric Inhibitory Polypeptide; Glucagon-Like Peptide 1; Half-Life; Healthy Volunteers; Humans; Hypoglycemic Agents; Injections, Subcutaneous; Male; Middle Aged; Young Adult | 2017 |
Effect of canagliflozin on circulating active GLP-1 levels in patients with type 2 diabetes: a randomized trial.
Canagliflozin has a robust inhibitory effect on sodium glucose transporter (SGLT)-2 and a mild inhibitory effect on SGLT1. The main purpose of this study was to investigate the effect of canagliflozin on circulating active glucagon-like peptide 1 (GLP-1) levels in patients with type 2 diabetes. Patients were randomly divided into a control group (n =15) and a canagliflozin-treated group (n =15). After hospitalization, the canagliflozin-treated group took 100 mg/day canagliflozin for the entire study, and after 3 days both groups took 20 mg/day teneligliptin for an additional 3 days. In a meal test, canagliflozin significantly decreased the area under curve (AUC) (0-120 min) for plasma glucose (PG) after 3 days when compared with that at baseline, and addition of teneligliptin to the canagliflozin-treated group further decreased it. A significant decrease in the AUC (0-120 min) for serum insulin by canagliflozin was obtained, but the addition of teneligliptin elevated the AUC, and thus abolished the significant difference from baseline. A significant increase in the AUC (0-120 min) of plasma active GLP-1 by canagliflozin-treatment compared with that at baseline was observed, and the addition of teneligliptin resulted in a further increase. However, canagliflozin-treatment did not change the AUC (0-120 min) of plasma active glucose-dependent insulinotropic peptide (GIP). In conclusions, canagliflozin-administration before meals decreased PG and serum insulin, and increased plasma active GLP-1 levels in patients with type 2 diabetes. Canagliflozin did not greatly influence plasma active GIP levels. Topics: Aged; Blood Glucose; Canagliflozin; Diabetes Mellitus, Type 2; Female; Gastric Inhibitory Polypeptide; Glucagon; Glucagon-Like Peptide 1; Humans; Hypoglycemic Agents; Insulin; Male; Middle Aged; Treatment Outcome | 2017 |
Influences of Breakfast on Clock Gene Expression and Postprandial Glycemia in Healthy Individuals and Individuals With Diabetes: A Randomized Clinical Trial.
The circadian clock regulates glucose metabolism by mediating the activity of metabolic enzymes, hormones, and transport systems. Breakfast skipping and night eating have been associated with high HbA. In healthy individuals, the expression level of. Breakfast consumption acutely affects clock and clock-controlled gene expression leading to normal oscillation. Breakfast skipping adversely affects clock and clock-controlled gene expression and is correlated with increased postprandial glycemic response in both healthy individuals and individuals with diabetes. Topics: Adult; Aged; AMP-Activated Protein Kinases; ARNTL Transcription Factors; Blood Glucose; Body Mass Index; Breakfast; Circadian Clocks; Cross-Over Studies; Diabetes Mellitus, Type 2; Gene Expression Regulation; Glucagon-Like Peptide 1; Glycated Hemoglobin; Homeostasis; Humans; Insulin; Middle Aged; Period Circadian Proteins; Postprandial Period; Sirtuin 1 | 2017 |
Liraglutide and Renal Outcomes in Type 2 Diabetes.
In a randomized, controlled trial that compared liraglutide, a glucagon-like peptide 1 analogue, with placebo in patients with type 2 diabetes and high cardiovascular risk who were receiving usual care, we found that liraglutide resulted in lower risks of the primary end point (nonfatal myocardial infarction, nonfatal stroke, or death from cardiovascular causes) and death. However, the long-term effects of liraglutide on renal outcomes in patients with type 2 diabetes are unknown.. We report the prespecified secondary renal outcomes of that randomized, controlled trial in which patients were assigned to receive liraglutide or placebo. The secondary renal outcome was a composite of new-onset persistent macroalbuminuria, persistent doubling of the serum creatinine level, end-stage renal disease, or death due to renal disease. The risk of renal outcomes was determined with the use of time-to-event analyses with an intention-to-treat approach. Changes in the estimated glomerular filtration rate and albuminuria were also analyzed.. A total of 9340 patients underwent randomization, and the median follow-up of the patients was 3.84 years. The renal outcome occurred in fewer participants in the liraglutide group than in the placebo group (268 of 4668 patients vs. 337 of 4672; hazard ratio, 0.78; 95% confidence interval [CI], 0.67 to 0.92; P=0.003). This result was driven primarily by the new onset of persistent macroalbuminuria, which occurred in fewer participants in the liraglutide group than in the placebo group (161 vs. 215 patients; hazard ratio, 0.74; 95% CI, 0.60 to 0.91; P=0.004). The rates of renal adverse events were similar in the liraglutide group and the placebo group (15.1 events and 16.5 events per 1000 patient-years), including the rate of acute kidney injury (7.1 and 6.2 events per 1000 patient-years, respectively).. This prespecified secondary analysis shows that, when added to usual care, liraglutide resulted in lower rates of the development and progression of diabetic kidney disease than placebo. (Funded by Novo Nordisk and the National Institutes of Health; LEADER ClinicalTrials.gov number, NCT01179048 .). Topics: Acute Kidney Injury; Aged; Albuminuria; Creatinine; Diabetes Mellitus, Type 2; Diabetic Nephropathies; Double-Blind Method; Female; Follow-Up Studies; Glomerular Filtration Rate; Glucagon-Like Peptide 1; Humans; Hypoglycemic Agents; Intention to Treat Analysis; Kidney Failure, Chronic; Liraglutide; Male; Middle Aged | 2017 |
Effects of Liraglutide on Weight Loss, Fat Distribution, and β-Cell Function in Obese Subjects With Prediabetes or Early Type 2 Diabetes.
Obesity is associated with an increased risk of type 2 diabetes and cardiovascular complications. The risk depends significantly on adipose tissue distribution. Liraglutide, a glucagon-like peptide 1 analog, is associated with weight loss, improved glycemic control, and reduced cardiovascular risk. We determined whether an equal degree of weight loss by liraglutide or lifestyle changes has a different impact on subcutaneous adipose tissue (SAT) and visceral adipose tissue (VAT) in obese subjects with prediabetes or early type 2 diabetes.. Sixty-two metformin-treated obese subjects with prediabetes or newly diagnosed type 2 diabetes, were randomized to liraglutide (1.8 mg/day) or lifestyle counseling. Changes in SAT and VAT levels (determined by abdominal MRI), insulin sensitivity (according to the Matsuda index), and β-cell function (β-index) were assessed during a multiple-sampling oral glucose tolerance test; and circulating levels of IGF-I and IGF-II were assessed before and after a comparable weight loss (7% of initial body weight).. After comparable weight loss, achieved by 20 patients per arm, and superimposable glycemic control, as reflected by HbA. Liraglutide effects on visceral obesity and β-cell function might provide a rationale for using this molecule in obese subjects in an early phase of glucose metabolism dysregulation natural history. Topics: Adipocytes; Blood Glucose; Body Mass Index; Diabetes Mellitus, Type 2; Female; Glucagon-Like Peptide 1; Glucose Tolerance Test; Glycated Hemoglobin; Humans; Hypoglycemic Agents; Insulin-Like Growth Factor I; Insulin-Like Growth Factor II; Insulin-Secreting Cells; Life Style; Liraglutide; Longitudinal Studies; Lost to Follow-Up; Male; Metformin; Middle Aged; Obesity; Prediabetic State; Risk Factors; Weight Loss | 2017 |
Single-Dose Metformin Enhances Bile Acid-Induced Glucagon-Like Peptide-1 Secretion in Patients With Type 2 Diabetes.
Despite a position as the first-line pharmacotherapy in type 2 diabetes, the glucose-lowering mechanisms of metformin remain to be fully clarified. Gut-derived modes of action, including suppression of bile acid reabsorption and a resulting increase in glucagon-like peptide-1 (GLP-1) secretion, have been proposed.. The aim of this study was to assess the GLP-1 secretory and glucometabolic effects of endogenously released bile, with and without concomitant single-dose administration of metformin in patients with type 2 diabetes.. Randomized, placebo-controlled, and double-blinded crossover study.. This study was conducted at Center for Diabetes Research, Gentofte Hospital, Denmark.. Fifteen metformin-treated patients with type 2 diabetes; all participants completed the study.. Four experimental study days in randomized order with administration of either 1500 mg metformin or placebo in combination with intravenous infusion of cholecystokinin (0.4 pmol × kg-1 × min-1) or saline.. Plasma GLP-1 excursions as measured by baseline-subtracted area under the curve.. Single-dose metformin further enhanced bile acid-mediated induction of GLP-1 secretion (P = 0.02), whereas metformin alone did not increase plasma GLP-1 concentrations compared with placebo (P = 0.17). Metformin, both with (P = 0.02) and without (P = 0.02) concomitant cholecystokinin-induced gallbladder emptying, elicited reduced plasma glucose excursions compared with placebo. No GLP-1-mediated induction of insulin secretion or suppression of glucagon was observed.. Metformin elicited an enhancement of the GLP-1 response to cholecystokinin-induced gallbladder emptying in patients with type 2 diabetes, whereas no derived effects on insulin or glucagon secretion were evident in this acute setting. Topics: Aged; Bile Acids and Salts; Blood Glucose; Cholecystokinin; Cross-Over Studies; Diabetes Mellitus, Type 2; Dose-Response Relationship, Drug; Double-Blind Method; Female; Gallbladder Emptying; Glucagon-Like Peptide 1; Humans; Male; Metformin; Middle Aged; Placebos | 2017 |
Effect of Butyrate and Inulin Supplementation on Glycemic Status, Lipid Profile and Glucagon-Like Peptide 1 Level in Patients with Type 2 Diabetes: A Randomized Double-Blind, Placebo-Controlled Trial.
Studies on humans with diabetes mellitus showed that the crosstalk between the intestinal microbiota and the host has a key role in controlling the disease. The aim of this study was to evaluate the effects of sodium butyrate and high performance inulin supplementation simultaneously or singly on glycemic status, lipid profile, and glucagon-like peptide 1 level in adults with type 2 diabetes mellitus. Sixty patients were recruited for the study. The participants were randomly allocated, using randomized block procedure, to one of the four treatment groups (A, B, C, or D). Group A received sodium butyrate capsules, group B received inulin supplement powder, group C was exposed to the concomitant use of inulin and sodium butyrate, and group D consumed placebo for 45 consecutive days. Markers of glycemia, lipid profile, and glucagon-like peptide 1 were measured pre- and post-intervention. Dietary supplementation in groups A, B, and C significantly reduced diastolic blood pressure in comparison with the placebo group (p<0.05). Also, intra-group statistical analysis showed that only treatment with sodium butyrate + inulin (group C) significantly reduced fasting blood sugar (p=0.049) and waist to hip ratio (p=0.020). Waist circumference in groups B and C reduced significantly after the intervention (p=0.007 and p=0.011; respectively). The post hoc Tukey tests showed significant increase in glucagon-like peptide 1 concentration in groups A and C in comparison with group D (p<0.05). The results suggest that inulin supplementation may be useful to diabetic patients and these effects could be increased with butyrate supplement. Topics: Blood Glucose; Butyrates; Diabetes Mellitus, Type 2; Dietary Supplements; Double-Blind Method; Female; Glucagon-Like Peptide 1; Humans; Inulin; Lipids; Male; Middle Aged | 2017 |
Glucagon-like peptide-1 levels and dipeptidyl peptidase-4 activity in type 2 diabetes.
Hyperglycemia is the major risk factor for microvascular complications in type 2 diabetes mellitus (T2DM) patients. This randomized controlled clinical trial aimed to investigate T2DM patients with microvascular complications with regard to possible relations among serum clusterin (CLU), amylin, secreted frizzled-related protein-4 (SFRP-4), glucagon-like peptide-1 (GLP-1) and dipeptidyl peptidase-4 (DPP-4) activities.. Subject groups were defined as follows: T2DM without complications (n=25, F/M=9/16, age 53.9±11.1 years); T2DM+Retinopathy (n=25, F/M=13/12, age 63.8±7.1 years); T2DM+Nephropathy (n=25, F/M=13/12, age 58.7±14.4 years); T2DM+Neuropathy (n=25, F/M=15/10, age 63.2±9.6 years); and healthy control subjects (HC) (n=25). CLU, amylin, SFRP-4, DPP-4 and GLP-1 (total and active) activities were measured and compared in blood samples from type 2 diabetic patients with and without microvascular complications.. Significantly lower levels of DPP-4 and GLP-1total (P. Topics: Adult; Aged; Diabetes Mellitus, Type 2; Diabetic Nephropathies; Diabetic Retinopathy; Dipeptidyl Peptidase 4; Female; Glucagon-Like Peptide 1; Humans; Hyperglycemia; Male; Middle Aged | 2017 |
Impaired beta cell sensitivity to incretins in type 2 diabetes is insufficiently compensated by higher incretin response.
The incretin effect is impaired in type 2 diabetes (T2D), but the underlying mechanisms are only partially understood. We investigated the relationships between the time course of the incretin effect and that of glucose-dependent insulinotropic polypeptide (GIP) and glucagon-like peptide-1 (GLP-1) during oral glucose tolerance tests (OGTTs), thereby estimating incretin sensitivity of the beta cell, and its associated factors.. Eight patients with T2D and eight matched subjects with normal glucose tolerance (NGT) received 25, 75, and 125 g OGTTs and corresponding isoglycemic glucose infusions (IIGI). The time course of the incretin effect, representing potentiation of insulin secretion by incretins (P. Relative incretin insensitivity is partly compensated for by higher incretin secretory responses. However, T2D shows both impairment in incretin sensitivity and abnormal compensation by incretin secretion. Topics: Aged; Biomarkers; Blood Glucose; Case-Control Studies; Denmark; Diabetes Mellitus, Type 2; Female; Gastric Inhibitory Polypeptide; Glucagon-Like Peptide 1; Glucose Tolerance Test; Humans; Incretins; Insulin; Insulin Secretion; Insulin-Secreting Cells; Male; Middle Aged; Models, Biological; Time Factors | 2017 |
A randomized controlled trial of Roux-en-Y gastrojejunostomy vs. gastroduodenostomy with respect to the improvement of type 2 diabetes mellitus after distal gastrectomy in gastric cancer patients.
The purpose of this study is to compare the effect of diabetes control induced by Roux-en-Y gastrojejunostomy(RY) vs Billroth-I reconstruction(BI) after distal gastrectomy in patients with early gastric cancer(EGC) and type 2 diabetes(T2DM). Forty EGC patients with T2DM, aged 20-80 years, who were expected to undergo curative distal gastrectomy were randomized 1:1 to RY(n = 20) or BI(n = 20). Diabetes medication status, biochemical and hormonal data including blood glucose, HbA1c, insulin, C-peptide, HOMA-IR, ghrelin, leptin, GLP-1, PYY, and GIP were evaluated for 12 months after surgery. Although pre- and postoperative 12-month fasting and postprandial glucose levels did not show a significant difference, HbA1c, C-peptide, and HOMA-IR levels were significantly improved at 12 months after surgery in both BI and RY groups. Sixty percent of RY patients and 20% of BI patients decreased their medication satisfying FBS<126 mg/dL and HbA1c<6.5% and 5% of BI patients stopped their medication satisfying the criteria of FBS<126 mg/dL and HbA1c<6.0%. The improvement patterns were more sustainable with less fluctuation in RY than in BI. On hormonal analysis, ghrelin and leptin levels were decreased and PYY and GIP levels were increased at 12 months after surgery in both groups without significant difference according to the reconstruction type and diabetic improvement status except ghrelin. In gastric cancer surgery, RY reconstruction showed better and more durable diabetes control compared to BI during the first year after surgery. Gastric cancer surgery led to decreased ghrelin and leptin and increased PYY and GIP, which might have a role in improving insulin resistance and glucose homeostasis. Topics: Aged; Diabetes Mellitus, Type 2; Duodenum; Female; Gastric Bypass; Gastric Inhibitory Polypeptide; Ghrelin; Glucagon-Like Peptide 1; Humans; Leptin; Male; Middle Aged; Peptide YY; Prospective Studies; Stomach; Stomach Neoplasms; Treatment Outcome | 2017 |
Endobarrier® in Grade I Obese Patients with Long-Standing Type 2 Diabetes: Role of Gastrointestinal Hormones in Glucose Metabolism.
The purpose of this study was to evaluate the efficacy and safety of Endobarrier® in grade 1 obese T2DM patients with poor metabolic control and the role of gastro-intestinal hormone changes on the metabolic outcomes.. Twenty-one patients aged 54.1 ± 9.5 years, diabetes duration 14.8 ± 8.5 years, BMI 33.4 ± 1.9 kg/m. Patients lost 14.9 ± 5.7 % of their total body weight. HbA1c decreased 1.3 % in the first month, but at the end of the study, the reduction was 0.6 %. HbA1c ≤ 7 % was achieved in 26.3 % of patients. No differences in GLP-1 AUC values were found before and after implant. Fasting plasma ghrelin and PYY concentrations increased from month 1 to 12. Conversely, fasting plasma glucagon concentrations decreased at month 1 and increased thereafter. Weight (β 0.152) and HbA1c decrease at month 1 (β 0.176) were the only variables predictive of HbA1c values at 12 months (adjusted R. Endobarrier® in T2DM patients with grade I obesity and poor metabolic control is associated with significant weight decrease and moderate reduction in HbA1c at month 12. Our data do not support a role for GLP-1 in the metabolic improvement in this subset of patients. Topics: Adult; Bariatric Surgery; Blood Glucose; Device Removal; Diabetes Mellitus, Type 2; Endoscopy, Gastrointestinal; Female; Gastrointestinal Hormones; Ghrelin; Glucagon; Glucagon-Like Peptide 1; Glucose; Humans; Insulin; Male; Middle Aged; Obesity, Morbid; Prosthesis Implantation | 2017 |
Acute Changes in Non-esterified Fatty Acids in Patients with Type 2 Diabetes Receiving Bariatric Surgery.
The purpose of this study was to compare acute changes of non-esterified fatty acids (NEFA) in relation to beta cell function (BCF) and insulin resistance in obese patients with type 2 diabetes (T2D) who underwent laparoscopic gastric bypass (GBP), laparoscopic sleeve gastrectomy (SG) or very low calorie diet (VLCD).. In a non-randomised study, fasting plasma samples were collected from 38 obese patients with T2D, matched for age, body mass index (BMI) and glycaemic control, who underwent GBP (11) or SG (14) or VLCD (13). Samples were collected the day before and 3 days after the intervention, during a 75-g oral glucose tolerance test. Glucose, insulin, c-peptide, glucagon like peptide-1 (GLP-1) and gastric inhibitory polypeptide (GIP) were measured, and individual NEFAs were measured using a triple-quadrupole liquid chromatography-mass spectrometry (LC-MS/MS). BCF by mathematical modelling and insulin resistance were estimated.. Palmitic acid significantly decreased after each intervention. Monounsaturated/polyunsaturated ratio (MUFA/PUFA) and unsaturated/saturated fat ratios increased after each intervention. BCF was improved only after VLCD. Linoleic acid was positively correlated with total insulin secretion (p = 0.03). Glucose sensitivity correlated with palmitic acid (p = 0.01), unsaturated/saturated ratio (p = 0.0008) and MUFA/PUFA (p = 0.009). HOMA-IR correlated with stearic acid (p = 0.03), unsaturated/saturated ratio (p = 0.005) and MUFA/PUFA (p = 0.009). GIP AUC0-120 correlated with stearic acid (p = 0.04), but not GLP-1.. GBP, SG and VLCD have similar acute effects on decreasing palmitic acid. Several NEFAs correlated with BCF parameters and HOMA-IR. Topics: Adult; Bariatric Surgery; Blood Glucose; Diabetes Mellitus, Type 2; Fatty Acids; Female; Glucagon-Like Peptide 1; Humans; Insulin; Insulin-Secreting Cells; Male; Middle Aged; Obesity; Obesity, Morbid; Tandem Mass Spectrometry; Young Adult | 2017 |
Addition of a dipeptidyl peptidase-4 inhibitor, sitagliptin, to ongoing therapy with the glucagon-like peptide-1 receptor agonist liraglutide: A randomized controlled trial in patients with type 2 diabetes.
To determine whether the addition of sitagliptin to pre-existing therapy with liraglutide changes glycaemic excursions after a mixed meal.. A total of 16 patients with type 2 diabetes treated with metformin and liraglutide (1.2 mg/d for ≥2 weeks) were randomized (sealed envelopes), within a cross-over design, to be studied on two occasions, after an overnight fast, with (1) sitagliptin (100 mg orally) and (2) placebo (patients and care givers blinded) administered 60 minutes before a mixed meal, or vice versa. Glucose excursions (incremental area under the curve [AUC]; primary endpoint) and insulin, C-peptide, glucagon and incretin concentrations were measured. The study setting was a metabolic study unit at a specialized diabetes hospital.. All 16 patients completed the study and were analysed. Glucose (AUC. Sitagliptin, in patients already treated with a GLP-1 receptor agonist (liraglutide), increased intact GLP-1 and GIP concentrations, but with marginal, non-significant effects on glycaemic control. GLP-1 receptors have probably been maximally stimulated by liraglutide. Our findings do not support combination treatment with GLP-1 receptor agonists and DPP-4 inhibitors, but longer-term trials are needed to support clinical recommendations. Topics: Adult; Aged; Blood Glucose; C-Peptide; Cross-Over Studies; Diabetes Mellitus, Type 2; Dipeptidyl-Peptidase IV Inhibitors; Drug Therapy, Combination; Female; Gastric Inhibitory Polypeptide; Glucagon; Glucagon-Like Peptide 1; Glucagon-Like Peptide-1 Receptor; Glycated Hemoglobin; Humans; Hypoglycemic Agents; Insulin; Liraglutide; Male; Metformin; Middle Aged; Sitagliptin Phosphate; Treatment Outcome | 2017 |
Metformin reduces the rate of small intestinal glucose absorption in type 2 diabetes.
In rodents, metformin slows intestinal glucose absorption, potentially increasing exposure of the distal gut to glucose to enhance postprandial glucagon-like peptide-1 (GLP-1) secretion. We evaluated the effects of metformin on serum 3-O-methylglucose (3-OMG; a marker of glucose absorption) and plasma total GLP-1 concentrations during a standardized intraduodenal infusion of glucose and 3-OMG in patients with type 2 diabetes. A total of 12 patients, treated with metformin 850 mg twice daily or placebo for 7 days each in a double-blind, randomized, crossover design (14 days' washout between treatments), were evaluated on days 5 or 8 of each treatment (6 subjects each). On each study day, 30 minutes after ingesting 850 mg metformin or placebo, patients received an infusion of glucose (60 g + 5 g 3-OMG, dissolved in water to 240 mL) via an intraduodenal catheter over the course of 120 minutes. Compared with placebo, metformin was associated with lower serum 3-OMG ( P < .001) and higher plasma total GLP-1 ( P = .003) concentrations. The increment in plasma GLP-1 after metformin vs placebo was related to the reduction in serum 3-OMG concentrations ( P = .019). Accordingly, metformin inhibits small intestinal glucose absorption, which may contribute to augmented GLP-1 secretion in type 2 diabetes. Topics: 3-O-Methylglucose; Aged; Cross-Over Studies; Diabetes Mellitus, Type 2; Double-Blind Method; Glucagon-Like Peptide 1; Glucose; Humans; Hypoglycemic Agents; Intestinal Absorption; Intestine, Small; Male; Metformin; Middle Aged; Postprandial Period | 2017 |
Sustained influence of metformin therapy on circulating glucagon-like peptide-1 levels in individuals with and without type 2 diabetes.
To investigate, in the Carotid Atherosclerosis: Metformin for Insulin Resistance (CAMERA) trial (NCT00723307), whether the influence of metformin on the glucagon-like peptide (GLP)-1 axis in individuals with and without type 2 diabetes (T2DM) is sustained and related to changes in glycaemia or weight, and to investigate basal and post-meal GLP-1 levels in patients with T2DM in the cross-sectional Diabetes Research on Patient Stratification (DIRECT) study.. CAMERA was a double-blind randomized placebo-controlled trial of metformin in 173 participants without diabetes. Using 6-monthly fasted total GLP-1 levels over 18 months, we evaluated metformin's effect on total GLP-1 with repeated-measures analysis and analysis of covariance. In the DIRECT study, we examined active and total fasting and 60-minute post-meal GLP-1 levels in 775 people recently diagnosed with T2DM treated with metformin or diet, using Student's t-tests and linear regression.. In CAMERA, metformin increased total GLP-1 at 6 (+20.7%, 95% confidence interval [CI] 4.7-39.0), 12 (+26.7%, 95% CI 10.3-45.6) and 18 months (+18.7%, 95% CI 3.8-35.7), an overall increase of 23.4% (95% CI 11.2-36.9; P < .0001) vs placebo. Adjustment for changes in glycaemia and adiposity, individually or combined, did not attenuate this effect. In the DIRECT study, metformin was associated with higher fasting active (39.1%, 95% CI 21.3-56.4) and total GLP-1 (14.1%, 95% CI 1.2-25.9) but not post-meal incremental GLP-1. These changes were independent of potential confounders including age, sex, adiposity and glycated haemoglobin.. In people without diabetes, metformin increases total GLP-1 in a sustained manner and independently of changes in weight or glycaemia. Metformin-treated patients with T2DM also have higher fasted GLP-1 levels, independently of weight and glycaemia. Topics: Adult; Aged; Blood Glucose; Body Weight; Case-Control Studies; Diabetes Mellitus, Type 2; Double-Blind Method; Fasting; Female; Glucagon-Like Peptide 1; Glycated Hemoglobin; Humans; Hypoglycemic Agents; Intercellular Signaling Peptides and Proteins; Male; Metformin; Middle Aged; Peptides; Postprandial Period | 2017 |
Effects of gemigliptin, a dipeptidyl peptidase-4 inhibitor, on lipid metabolism and endotoxemia after a high-fat meal in patients with type 2 diabetes.
We aimed to investigate the effects of gemigliptin, a dipeptidyl peptidase-4 inhibitor, on postprandial lipoprotein levels and endotoxemia in a randomized, double-blind, placebo-controlled, crossover study. Ten people with type 2 diabetes mellitus (T2DM), inadequately controlled with oral antidiabetic medications and/or lifestyle modification, were randomized to gemigliptin or placebo for 4 weeks. At the end of each treatment phase, the study participants underwent a high-fat meal tolerance test and needle aspiration of abdominal subcutaneous adipose tissue. The median (range) fasting and total area under the curve of apolipoprotein B48 (ApoB48) were significantly lower with gemigliptin than with placebo (2.9 [1.5-15.8] µg/mL vs 4.2 [1.3-23.4] µg/mL; P = .020; 35.3 [14.4-87.4] µg/mL × hour vs 42.2 [17.5-109.0] µg/mL × hour; P = .020, respectively), whereas apolipoprotein B100 showed no significant difference. Serum endotoxin levels were undetectable in 70% of the samples, so we were not able to evaluate the effect of gemigliptin on endotoxemia. The gene expression of inflammatory cytokines in subcutaneous adipose tissue was not affected by gemigliptin. Gemigliptin reduced ApoB48 levels after a high-fat meal in participants with T2DM. Whether systemic endotoxin levels can be reduced by gemigliptin requires further investigation. Topics: Adiponectin; Adult; Aged; Apolipoprotein B-100; Apolipoprotein B-48; Blood Glucose; C-Reactive Protein; Cholesterol; Cholesterol, HDL; Cholesterol, LDL; Cross-Over Studies; Cytokines; Diabetes Mellitus, Type 2; Diet, High-Fat; Dipeptidyl-Peptidase IV Inhibitors; Double-Blind Method; Endotoxemia; Endotoxins; Female; Glucagon; Glucagon-Like Peptide 1; Humans; Insulin; Insulin Resistance; Interleukin-6; Lipid Metabolism; Male; Middle Aged; Piperidones; Postprandial Period; Pyrimidines; RNA, Messenger; Subcutaneous Fat, Abdominal; Transcriptome; Triglycerides; Tumor Necrosis Factor-alpha | 2017 |
Exenatide improves diastolic function and attenuates arterial stiffness but does not alter exercise capacity in individuals with type 2 diabetes.
Exercise is recommended as a cornerstone of treatment for type 2 diabetes mellitus (T2DM), however, it is often poorly adopted by patients. Even in the absence of apparent cardiovascular disease, persons with T2DM have an impaired ability to carry out maximal and submaximal exercise and these impairments are correlated with cardiac and endothelial dysfunction. Glucagon-like pepetide-1 (GLP-1) augments endothelial and cardiac function in T2DM. We hypothesized that administration of a GLP-1 agonist (exenatide) would improve exercise capacity in T2DM.. Administration of exenatide improved cardiac function and reduced arterial stiffness, however, these changes were not accompanied by improved functional exercise capacity. In order to realize the benefits of this drug on exercise capacity, combining exenatide with aerobic exercise training in participants with T2DM may be warranted. Topics: Aged; Arteries; Diabetes Mellitus, Type 2; Diabetic Angiopathies; Diabetic Cardiomyopathies; Double-Blind Method; Endothelium, Vascular; Exenatide; Exercise Tolerance; Female; Follow-Up Studies; Glucagon-Like Peptide 1; Heart Ventricles; Humans; Hypoglycemic Agents; Male; Middle Aged; Oxygen Consumption; Peptides; Pulse Wave Analysis; Sedentary Behavior; Vascular Stiffness; Venoms; Ventricular Dysfunction, Left | 2017 |
Exenatide induces an increase in vasodilatory and a decrease in vasoconstrictive mediators.
In view of the known vasodilatory effects of glucagon-like peptide-1 and exenatide, we investigated the effects of exenatide on vasoactive factors. We analysed blood samples and mononuclear cells (MNCs) from a previous study, collected after a single dose and 12 weeks of exenatide or placebo treatment in a series of 24 patients with type 2 diabetes mellitus. After exenatide treatment, plasma concentrations of atrial natriuretic peptide, cyclic guanyl monophosphate (cGMP) and cyclic adenyl monophosphate increased significantly at 12 weeks. Plasma cGMP and adenylate cyclase expression in MNCs increased significantly after a single dose. Angiotensinogen concentration fell significantly 2 hours after a single dose and at 12 weeks, while renin and angiotensin II levels fell significantly only after a single dose and not after 12 weeks of treatment. Exenatide also suppressed the plasma concentration of transforming growth factor-β and the expression of P311 in MNCs at 12 weeks. Thus, exenatide induces an increase in a series of vasodilators, while suppressing the renin-angiotensin system. These changes may contribute to the overall vasodilatory effect of exenatide. Topics: Adenylyl Cyclases; Angiotensinogen; Anti-Obesity Agents; Antihypertensive Agents; Atrial Natriuretic Factor; Blood Pressure; Cyclic AMP; Cyclic GMP; Diabetes Mellitus, Type 2; Exenatide; Gene Expression Regulation; Glucagon-Like Peptide 1; Humans; Hypoglycemic Agents; Leukocytes, Mononuclear; Nerve Tissue Proteins; Obesity; Oncogene Proteins; Peptides; Renin-Angiotensin System; Reproducibility of Results; Single-Blind Method; Transforming Growth Factor beta; Venoms | 2017 |
GLP-1 analogue-induced weight loss does not improve obesity-induced AT dysfunction.
Glucagon-like peptide-1 (GLP-1) analogues aid weight loss that improves obesity-associated adipose tissue (AT) dysfunction. GLP-1 treatment may however also directly influence AT that expresses the GLP-1 receptor (GLP-1R). The present study aimed to assess the impact of GLP-1 analogue treatment on subcutaneous AT (SCAT) inflammatory and fibrotic responses, compared with weight loss by calorie reduction (control). Among the 39 participants with Type 2 diabetes recruited, 30 age-matched participants were randomized to 4 months treatment with Liraglutide ( Topics: Adiponectin; Adipose Tissue; Aged; Diabetes Mellitus, Type 2; Extracellular Matrix; Glucagon-Like Peptide 1; Humans; Hypoglycemic Agents; Inflammation; Leptin; Liraglutide; Male; Middle Aged; Obesity | 2017 |
Liraglutide causes large and rapid epicardial fat reduction.
Epicardial adipose tissue (EAT), the visceral fat depot of the heart, is a modifiable cardiovascular risk factor and emerging therapeutic target. Liraglutide, an analog of glucagon-like peptide-1, is indicated for the treatment of type 2 diabetes mellitus. Liraglutide has recently been shown to reduce cardiovascular risk. Nevertheless, whether liraglutide could reduce EAT is unknown.. To test the hypothesis, a 6-month randomized, open-label, controlled study was performed in 95 type 2 diabetic subjects with body mass index (BMI) ≥27 kg/m. In the liraglutide group, EAT decreased from 9.6 ± 2 to 6.8 ± 1.5 and 6.2 ± 1.5 mm (P < 0.001), accounting for a -29% and -36% of reduction at 3 and 6 months, respectively, whereas there was no EAT reduction in the metformin group; BMI and hemoglobinA1c improved only in the liraglutide group after 6 months.. Liraglutide causes a substantial and rapid EAT reduction. Liraglutide cardiometabolic effects may be EAT-mediated. Topics: Adipose Tissue; Adult; Body Mass Index; Cardiovascular Diseases; Diabetes Mellitus, Type 2; Female; Glucagon-Like Peptide 1; Glycated Hemoglobin; Humans; Hypoglycemic Agents; Intra-Abdominal Fat; Liraglutide; Male; Metformin; Middle Aged; Pericardium; Risk Factors | 2017 |
Chronic liraglutide therapy induces an enhanced endogenous glucagon-like peptide-1 secretory response in early type 2 diabetes.
Sustained exogenous stimulation of a hormone-specific receptor can affect endogenous hormonal regulation. In this context, little is known about the impact of chronic treatment with glucagon-like peptide-1 (GLP-1) agonists on the endogenous GLP-1 response. We therefore evaluated the impact of chronic liraglutide therapy on endogenous GLP-1 and glucose-dependent insulinotropic polypeptide (GIP) response to an oral glucose challenge. A total of 51 people with type 2 diabetes of 2.6 ± 1.9 years' duration were randomized to daily subcutaneous liraglutide or placebo injection and followed for 48 weeks, with an oral glucose tolerance test (OGTT) every 12 weeks. GLP-1 and GIP responses were assessed according to their respective area under the curve (AUC) from measurements taken at 0, 30, 60, 90 and 120 minutes during each OGTT. There were no differences in AUC Topics: Adult; Diabetes Mellitus, Type 2; Double-Blind Method; Enteroendocrine Cells; Enzyme-Linked Immunosorbent Assay; Gastric Inhibitory Polypeptide; Glucagon-Like Peptide 1; Glucose Tolerance Test; Glycated Hemoglobin; Humans; Hyperglycemia; Hypoglycemia; Hypoglycemic Agents; Incretins; Injections, Subcutaneous; Insulin-Secreting Cells; Liraglutide; Time Factors | 2017 |
Effectiveness of acarbose in treating elderly patients with diabetes with postprandial hypotension.
: Postprandial hypotension (PPH) is a common condition that occurs primarily in elderly patients with type 2 diabetes mellitus (T2DM). This study aimed to assess the effectiveness of acarbose for PPH; it also investigated possible mechanisms behind PPH development. This single-blind, randomized controlled trial included 91 elderly patients with T2DM, aged between 60 and 80 years, who were inpatients at Beijing Hospital between March 2012 and November 2014. The patients were included into one of three groups: Group A, patients with T2DM without PPH; Group B, patients with T2DM with PPH receiving placebo; and Group C, patients with T2DM with PPH receiving acarbose. After an overnight fast, patients received a single dose of acarbose (100 mg) or placebo and then consumed a standardized 450 kcal meal. Blood pressure, glucose levels, heart rate (HR), and catecholamine levels were evaluated. Acarbose ameliorated PPH as determined by significant improvements in the duration and maximal fall in blood pressure (both p<0.001); however, no differences in HR and blood glucose levels were observed. In patients with PPH, blood pressure was correlated with blood glucose and HR variability values (p<0.05). Correlations between epinephrine and glucagon-like peptide-1 with blood pressure in groups A and C were largely lost in group B. Acarbose reduced postprandial blood pressure fluctuations in elderly patients with diabetes. PPH may be related to impaired autonomic nervous system function, reduced catecholamine secretion, and postprandial fluctuations in blood glucose levels.. Chinese Clinical Trial Registry ChiCTR-IPR-15006177. Topics: Acarbose; Aged; Aged, 80 and over; Blood Glucose; Blood Glucose Self-Monitoring; Blood Pressure; C-Peptide; Catecholamines; Demography; Diabetes Mellitus, Type 2; Glucagon-Like Peptide 1; Heart Rate; Humans; Hypotension; Postprandial Period; Treatment Outcome | 2017 |
Albiglutide for the treatment of type 2 diabetes mellitus: An integrated safety analysis of the HARMONY phase 3 trials.
Glucagon-like peptide-1 receptor agonists (GLP-1 RAs) stimulate the incretin system and lower glycaemic parameters in type 2 diabetes mellitus (T2DM). This analysis of clinical studies of up to 3years evaluated the safety of albiglutide, a GLP-1 RA, in people with T2DM.. Integrated safety analysis included seven phase-3 T2DM studies of albiglutide compared with placebo and/or active comparators (a dipeptidyl peptidase-4 inhibitor, GLP-1 RA, insulin, sulphonylurea, and thiazolidinedione).. Studies of 32months (HARMONY 7), 1year (HARMONY 6), and 3years (HARMONY 1-5), reported similar rates of adverse events (AEs) (84.8%, 82.3%), and serious AEs (13.1%, 12.9%) between albiglutide and all comparators, respectively. AEs that did not differ between the groups included symptomatic or severe hypoglycaemia as well as nausea (12.0%, 11.3%) and vomiting (5.3%, 4.7%) for albiglutide and all comparators, respectively. According to the Medical Dictionary for Regulatory Activities preferred terms, only diarrhoea (13.7%, 9.9%), injection-site reaction (9.0%, 2.0%), and peripheral oedema (4.5%, 6.8%) had at least 2% difference between the albiglutide and all-comparator groups. In a similar integrated analysis, pancreatitis occurred more often with albiglutide (0.3%, 0.1%). Renal and cardiac function did not differ between the two groups.. In an integrated analysis of seven phase 3 clinical trials, albiglutide-treated patients experienced frequencies of AEs (including cardiovascular and renal) similar to the all-comparators group treated with other T2DM medications or placebo. Albiglutide treatment was associated with higher rates of diarrhoea and injection-site reactions, but not increased nausea and vomiting, versus all comparators. Topics: Adult; Aged; Blood Glucose; Diabetes Mellitus, Type 2; Dipeptidyl-Peptidase IV Inhibitors; Drug Therapy, Combination; Drug-Related Side Effects and Adverse Reactions; Female; Glucagon-Like Peptide 1; Glucagon-Like Peptide-1 Receptor; Humans; Hypoglycemia; Hypoglycemic Agents; Incretins; Injections; Insulin; Male; Middle Aged; Sulfonylurea Compounds | 2017 |
Liraglutide Reduces CNS Activation in Response to Visual Food Cues Only After Short-term Treatment in Patients With Type 2 Diabetes.
Glucagon-like peptide-1 receptor agonists (GLP-1RAs) are associated with reduced appetite and body weight. We investigated whether these effects could be mediated by the central nervous system (CNS).. We performed a randomized crossover study in obese patients with type 2 diabetes (n = 20, mean age 59.3 ± 4.1 years, mean BMI 32 ± 4.7 kg/m(2)), consisting of two periods of 12-week treatment with either liraglutide 1.8 mg or insulin glargine. Using functional MRI, we determined the effects of treatment on CNS responses to viewing food pictures in the fasted condition and 30 min after meal intake.. After 12 weeks, the decrease in HbA1c was larger with liraglutide versus insulin glargine (Δ-0.7% vs. -0.2%, P < 0.001). Body weight decreased during liraglutide versus insulin glargine (Δ-3.3 kg vs. 0.8 kg, P < 0.001). After 10 days, patients treated with liraglutide, compared with insulin glargine, showed decreased responses to food pictures in insula and putamen (P ≤ 0.02). In addition, liraglutide enhanced the satiating effect of meal intake on responses in putamen and amygdala (P ≤ 0.05). Differences between liraglutide and insulin glargine were not observed after 12 weeks.. Compared with insulin, liraglutide decreased CNS activation significantly only after short-term treatment, suggesting that these effects of GLP-1RA on the CNS may contribute to the induction of weight loss, but not necessarily to its maintenance, in view of the absence of an effect of liraglutide on CNS activation in response to food pictures after longer-term treatment. Topics: Blood Glucose; Body Weight; Brain; Cross-Over Studies; Cues; Diabetes Mellitus, Type 2; Fasting; Female; Food; Glucagon-Like Peptide 1; Humans; Hypoglycemic Agents; Insulin; Insulin Glargine; Liraglutide; Male; Middle Aged; Obesity; Satiation | 2016 |
Postprandial hyperglycemia was ameliorated by taking metformin 30 min before a meal than taking metformin with a meal; a randomized, open-label, crossover pilot study.
Taking metformin with a meal has been shown to decrease bioavailability of metformin. We hypothesized that taking metformin 30 min before a meal improves glucose metabolism. As an animal model, 18 Zucker-rats were divided into three groups as follows: no medication (Control), metformin (600 mg/kg) with meal (Met), and metformin 10 min before meal (pre-Met). In addition, five diabetic patients were recruited and randomized to take metformin (1000 mg) either 30 min before a meal (pre-Met protocol) or with a meal (Met protocol). In the animal model, the peak glucose level of pre-Met (7.8 ± 1.5 mmol/L) was lower than that of Control (12.6 ± 2.5 mmol/L, P = 0.010) or Met (14.1 ± 2.9 mmol/L, P = 0.020). Although there was no statistical difference among the three groups, total GLP-1 level at t = 0 min of pre-Met (7.4 ± 2.7 pmol/L) tended to be higher than that of Control (3.7 ± 2.0 pmol/L, P = 0.030) or Met (3.9 ± 1.2 pmol/L, P = 0.020). In diabetic patients, the peak glucose level of pre-Met protocol (7.0 ± 0.4 mmol/L) was lower than that of Met protocol (8.5 ± 0.9 mmol/L, P = 0.021). Total GLP-1 level at t = 30 min of pre-Met protocol (11.0 ± 6.1 pmol/L) was higher than that of Met protocol (6.7 ± 3.9 pmol/L, P = 0.033). Taking metformin 30 min before a meal ameliorated postprandial hyperglycemia. This promises to be a novel approach for postprandial hyperglycemia. Topics: Animals; Cross-Over Studies; Diabetes Mellitus, Type 2; Glucagon-Like Peptide 1; Humans; Hyperglycemia; Hypoglycemic Agents; Metformin; Pilot Projects; Rats, Zucker | 2016 |
Effect of the GLP-1 Receptor Agonist Lixisenatide on Counterregulatory Responses to Hypoglycemia in Subjects With Insulin-Treated Type 2 Diabetes.
Counterregulatory responses are critical to prevent hypoglycemia in subjects with type 2 diabetes. This is particularly important in insulin-treated patients. This study explored the effect of the glucagon-like peptide 1 receptor agonist lixisenatide on the hormonal counterregulatory responses to insulin-induced hypoglycemia when added to basal insulin therapy in subjects with type 2 diabetes.. The study was a single-center, double-blind, randomized, placebo-controlled crossover study involving 18 subjects with type 2 diabetes (11 males) with a mean age of 55 years, diabetes duration of 12 years, HbA1c level of 7.7%, fasting blood glucose (FBG) concentration of 9.7 mmol/L, and a BMI of 33 kg/m(2), who were treated with basal insulin (mean duration 7 years, daily dose 39 units/day) and metformin (mean daily dose 2.1 g). Subjects received treatment with lixisenatide or placebo for 6 weeks in random order, with a 4-week washout period in between. After 6 weeks of treatment, subjects underwent a two-step hyperinsulinemic hypoglycemic clamp at 3.5 and 2.8 mmol/L.. After 6 weeks of treatment, HbA1c and FBG levels were lower after lixisenatide therapy than after placebo therapy. At the hypoglycemic level of 3.5 mmol/L, glucagon and epinephrine levels were significantly lower during lixisenatide treatment than during placebo treatment, whereas at 2.8 mmol/L glucagon and epinephrine levels did not differ between the subjects. Cortisol, pancreatic polypeptide, and norepinephrine levels did not differ significantly between the treatments.. Glucagon and epinephrine levels are reduced by lixisenatide at a concentration of 3.5 mmol/L, but their counterregulatory responses to deep hypoglycemia at a concentration of 2.8 mmol/L are sustained during treatment with lixisenatide in combination with basal insulin. Topics: Blood Glucose; Cross-Over Studies; Diabetes Mellitus, Type 2; Double-Blind Method; Female; Glucagon; Glucagon-Like Peptide 1; Glucagon-Like Peptide-1 Receptor; Glycated Hemoglobin; Humans; Hydrocortisone; Hypoglycemia; Hypoglycemic Agents; Insulin; Male; Metformin; Middle Aged; Peptides | 2016 |
The effect of encapsulated glutamine on gut peptide secretion in human volunteers.
Weight loss and improved blood glucose control after bariatric surgery have been attributed in part to increased ileal nutrient delivery with enhanced release of glucagon-like peptide 1 (GLP-1). Non-surgical strategies to manage obesity are required. The aim of the current study was to assess whether encapsulated glutamine, targeted to the ileum, could increase GLP-1 secretion, improve glucose tolerance or reduce meal size.. A single-center, randomised, double blind, placebo-controlled, cross-over study was performed in 24 healthy volunteers and 8 patients with type 2 diabetes. Fasting participants received a single dose of encapsulated ileal-release glutamine (3.6 or 6.0 g) or placebo per visit with blood sampling at baseline and for 4h thereafter. Glucose tolerance and meal size were studied using a 75 g oral glucose tolerance test and ad libitum meal respectively.. In healthy volunteers, ingestion of 6.0 g glutamine was associated with increased GLP-1 concentrations after 90 min compared with placebo (mean 10.6 pg/ml vs 6.9 pg/ml, p=0.004), increased insulin concentrations after 90 min (mean 70.9 vs 48.5, p=0.048), and increased meal size at 120 min (mean 542 g eaten vs 481 g, p=0.008). Ingestion of 6.0 g glutamine was not associated with significant differences in GLP-1, glucose or insulin concentrations after a glucose tolerance test in healthy or type 2 diabetic participants.. Single oral dosing of encapsulated glutamine did not provoke consistent increases in GLP-1 and insulin secretion and was not associated with beneficial metabolic effects in healthy volunteers or patients with type 2 diabetes. Topics: Adult; Aged; Appetite; Appetite Depressants; Blood Glucose; Diabetes Mellitus, Type 2; Double-Blind Method; Female; Glucagon-Like Peptide 1; Glucose Tolerance Test; Glutamine; Humans; Insulin; Male; Middle Aged; Young Adult | 2016 |
A Randomised Crossover Trial: The Effect of Inulin on Glucose Homeostasis in Subtypes of Prediabetes.
Fermentable carbohydrates (FCHO) have been shown to improve insulin sensitivity in normoglycaemic and insulin-resistant subjects. However, there are no data on subjects with prediabetes. We aimed to investigate the effect of the FCHO inulin, on glucose homeostasis in subjects with prediabetes.. In a double-blind and placebo-controlled crossover study, 40 volunteers with prediabetes were randomly allocated to take 30 g/day of inulin or cellulose for 2 weeks in a crossover trial, following a 4-week dose-escalation run-in. Fasting insulin and glucose were measured for all subjects. Fifteen of the 40 subjects also underwent a meal tolerance test to assess insulin sensitivity, free fatty acids and glucagon-like peptide-1 concentrations. A subanalysis was carried out to examine any differences between the prediabetes subtypes.. Inulin was associated with a significant increase in (0-30 min)incremental AUC (iAUC) for insulin (treatment: p < 0.04) and (0-60 min)iAUC for insulin (treatment: p < 0.04) compared to control. There was a significant reduction in insulin resistance measured by the homeostatic model assessment in the isolated-impaired fasting glucose (p < 0.05) but not in the isolated-impaired glucose tolerance groups (p = 0.59).. The FCHO, inulin, may have unique metabolic effects that are of particular benefit to people at risk of diabetes, which warrant further investigation. Topics: Aged; Blood Glucose; Body Mass Index; Cross-Over Studies; Diabetes Mellitus, Type 2; Double-Blind Method; Fatty Acids, Nonesterified; Female; Glucagon-Like Peptide 1; Homeostasis; Humans; Insulin; Insulin Resistance; Inulin; Male; Middle Aged; Prediabetic State; Risk Factors | 2016 |
Efficacy and safety of once-weekly GLP-1 receptor agonist albiglutide (HARMONY 2): 52 week primary endpoint results from a randomised, placebo-controlled trial in patients with type 2 diabetes mellitus inadequately controlled with diet and exercise.
Additional safe and effective therapies for type 2 diabetes are needed, especially ones that do not cause weight gain and have a low risk of hypoglycaemia. The present study evaluated albiglutide as monotherapy.. In this placebo-controlled study, 309 patients (aged ≥ 18 years) with type 2 diabetes inadequately controlled by diet and exercise and who were not using a glucose-lowering agent (HbA1c 7.0-10.0% [53.00-85.79 mmol/mol], body mass index 20-45 kg/m(2), and fasting C-peptide ≥ 0.26 nmol/l) were randomised (1:1:1 on a fixed randomisation schedule using an interactive voice response system) to receive once-weekly albiglutide 30 mg (n = 102) or 50 mg (n = 102) or matching placebo (n = 105). The study treatments were blinded to both patients and study personnel. All study data were collected at individual patient clinic visits. The primary efficacy endpoint was change in HbA1c from baseline to week 52. The primary analysis was applied to the intent-to-treat population. Additional efficacy and safety endpoints were assessed.. At week 52, both albiglutide 30 mg and 50 mg were superior to placebo in reducing HbA1c. The least-squares means treatment difference from placebo was -0.84% (95% CI -1.11%, -0.58%; p < 0.0001) with albiglutide 30 mg and -1.04% (-1.31%, -0.77%; p < 0.0001) with albiglutide 50 mg. Injection-site reactions were reported more frequently with albiglutide (30 mg: 17.8%; 50 mg: 22.2%) than with placebo (9.9%). Other commonly reported adverse events included nausea, diarrhoea, vomiting and hypoglycaemia; the incidences of these were generally similar across treatment groups.. Albiglutide is safe and effective as monotherapy and significantly lowered HbA1c levels over 52 weeks, did not cause weight gain, and had good gastrointestinal tolerability and a low rate of hypoglycaemia compared with placebo. Trial registration ClinicalTrials.gov NCT00849017 Funding This study was sponsored by GlaxoSmithKline. Topics: Adult; Aged; Biomarkers; Diabetes Mellitus, Type 2; Diet; Exercise; Female; Follow-Up Studies; Glucagon-Like Peptide 1; Glucagon-Like Peptide-1 Receptor; Glycated Hemoglobin; Humans; Hypoglycemic Agents; Male; Middle Aged; Treatment Outcome | 2016 |
Administration of resveratrol for 5 wk has no effect on glucagon-like peptide 1 secretion, gastric emptying, or glycemic control in type 2 diabetes: a randomized controlled trial.
Resveratrol has been reported to lower glycemia in rodent models of type 2 diabetes associated with the stimulation of glucagon-like peptide 1 (GLP-1), which is known to slow gastric emptying, stimulate insulin secretion, and suppress glucagon secretion and energy intake.. We evaluated the effects of 5 wk of resveratrol treatment on GLP-1 secretion, gastric emptying, and glycemic control in type 2 diabetes.. Fourteen patients with diet-controlled type-2 diabetes [mean ± SEM glycated hemoglobin (HbA1c): 6.4 ± 0.2% (46.4 ± 2.2 mmol/mol)] received resveratrol (500 mg twice daily) or a placebo over two 5-wk intervention periods with a 5-wk washout period in between in a double-blind, randomized, crossover design. Before and after each intervention period (4 visits), body weight and HbA1c were measured, and patients were evaluated after an overnight fast with a standardized mashed-potato meal labeled with 100 μg (13)C-octanoic acid to measure blood glucose and plasma GLP-1 concentrations and gastric emptying (breath test) over 240 min. Daily energy intake was estimated from 3-d food diaries during the week before each visit.. Fasting and postprandial blood glucose and plasma total GLP-1 as well as gastric emptying were similar at each assessment, and the change in each variable from weeks 0 to 5 did not differ between resveratrol and placebo groups. Similarly, changes in HbA1c, daily energy intake, and body weight after 5 wk did not differ between the 2 treatments.. In patients with diet-controlled type 2 diabetes, 5 wk of twice-daily 500 mg-resveratrol supplementation had no effect on GLP-1 secretion, glycemic control, gastric emptying, body weight, or energy intake. Our observations do not support the use of resveratrol for improving glycemic control. This trial was registered at www.anzctr.org.au as ACTRN12613000717752. Topics: Aged; Blood Glucose; Body Weight; Diabetes Mellitus, Type 2; Double-Blind Method; Energy Intake; Female; Gastric Emptying; Glucagon-Like Peptide 1; Glycated Hemoglobin; Humans; Hypoglycemic Agents; Insulin; Male; Postprandial Period; Resveratrol; Stilbenes | 2016 |
Alogliptin, a Dipeptidyl Peptidase 4 Inhibitor, Prevents the Progression of Carotid Atherosclerosis in Patients With Type 2 Diabetes: The Study of Preventive Effects of Alogliptin on Diabetic Atherosclerosis (SPEAD-A).
Recent experimental studies have shown that dipeptidyl peptidase 4 (DPP-4) inhibitors have antiatherosclerotic benefits in glucagon-like peptide 1-dependent and -independent manners. The current study investigated the effects of alogliptin, a DPP-4 inhibitor, on the progression of carotid atherosclerosis in patients with type 2 diabetes mellitus (T2DM).. This prospective, randomized, open-label, blinded-end point, multicenter, parallel-group, comparative study included 341 patients with T2DM free of a history of apparent cardiovascular diseases recruited at 11 clinical units and randomly allocated to treatment with alogliptin (n = 172) or conventional treatment (n = 169). Primary outcomes were changes in mean common and maximum intima-media thickness (IMT) of the carotid artery measured by carotid arterial echography during a 24-month treatment period.. Alogliptin treatment had a more potent glucose-lowering effect than the conventional treatment (-0.3 ± 0.7% vs. -0.1 ± 0.8%, P = 0.004) without an increase of hypoglycemia. Changes in the mean common and the right and left maximum IMT of the carotid arteries were significantly greater after alogliptin treatment than after conventional treatment (-0.026 mm [SE 0.009] vs. 0.005 mm [SE 0.009], P = 0.022; -0.045 mm [SE 0.018] vs. 0.011 mm [SE 0.017], P = 0.025, and -0.079 mm [SE 0.018] vs. -0.015 mm [SE 0.018], P = 0.013, respectively).. Alogliptin treatment attenuated the progression of carotid IMT in patients with T2DM free of apparent cardiovascular disease compared with the conventional treatment. Topics: Aged; Atherosclerosis; Blood Glucose; Carotid Arteries; Carotid Artery Diseases; Carotid Intima-Media Thickness; Diabetes Mellitus, Type 2; Dipeptidyl-Peptidase IV Inhibitors; Disease Progression; Female; Glucagon-Like Peptide 1; Humans; Hypoglycemic Agents; Japan; Male; Middle Aged; Piperidines; Prospective Studies; Uracil | 2016 |
Evaluation of Efficacy and Safety of the Glucagon Receptor Antagonist LY2409021 in Patients With Type 2 Diabetes: 12- and 24-Week Phase 2 Studies.
Type 2 diabetes pathophysiology is characterized by dysregulated glucagon secretion. LY2409021, a potent, selective small-molecule glucagon receptor antagonist that lowers glucose was evaluated for efficacy and safety in patients with type 2 diabetes.. The efficacy (HbA1c and glucose) and safety (serum aminotransferase) of once-daily oral administration of LY2409021 was assessed in two double-blind studies. Phase 2a study patients were randomized to 10, 30, or 60 mg of LY2409021 or placebo for 12 weeks. Phase 2b study patients were randomized to 2.5, 10, or 20 mg LY2409021 or placebo for 24 weeks.. LY2409021 produced reductions in HbA1c that were significantly different from placebo over both 12 and 24 weeks. After 12 weeks, least squares (LS) mean change from baseline in HbA1c was -0.83% (10 mg), -0.65% (30 mg), and -0.66% (60 mg) (all P < 0.05) vs. placebo, 0.11%. After 24 weeks, LS mean change from baseline in HbA1c was -0.45% (2.5 mg), -0.78% (10 mg, P < 0.05), -0.92% (20 mg, P < 0.05), and -0.15% with placebo. Increases in serum aminotransferase, fasting glucagon, and total fasting glucagon-like peptide-1 (GLP-1) were observed; levels returned to baseline after drug washout. Fasting glucose was also lowered with LY2409021 at doses associated with only modest increases in aminotransferases (mean increase in alanine aminotransferase [ALT] ≤10 units/L). The incidence of hypoglycemia in the LY2409021 groups was not statistically different from placebo.. In patients with type 2 diabetes, glucagon receptor antagonist treatment significantly lowered HbA1c and glucose levels with good overall tolerability and a low risk for hypoglycemia. Modest, reversible increases in serum aminotransferases were observed. Topics: Adult; Aged; Biphenyl Compounds; Blood Glucose; Diabetes Mellitus, Type 2; Double-Blind Method; Female; Glucagon-Like Peptide 1; Glycated Hemoglobin; Humans; Hypoglycemia; Hypoglycemic Agents; Male; Middle Aged; Receptors, Glucagon; Transaminases; Young Adult | 2016 |
Meal sequence and glucose excursion, gastric emptying and incretin secretion in type 2 diabetes: a randomised, controlled crossover, exploratory trial.
Investigation of dietary therapy for diabetes has focused on meal size and composition; examination of the effects of meal sequence on postprandial glucose management is limited. The effects of fish or meat before rice on postprandial glucose excursion, gastric emptying and incretin secretions were investigated.. The experiment was a single centre, randomised controlled crossover, exploratory trial conducted in an outpatient ward of a private hospital in Osaka, Japan. Patients with type 2 diabetes (n = 12) and healthy volunteers (n = 10), with age 30-75 years, HbA1c 9.0% (75 mmol/mol) or less, and BMI 35 kg/m(2) or less, were randomised evenly to two groups by use of stratified randomisation, and subjected to meal sequence tests on three separate mornings; days 1 and 2, rice before fish (RF) or fish before rice (FR) in a crossover fashion; and day 3, meat before rice (MR). Pre- and postprandial levels of glucose, insulin, C-peptide and glucagon as well as glucagon-like peptide-1 (GLP-1) and glucose-dependent insulinotropic polypeptide were evaluated. Gastric emptying rate was determined by (13)C-acetate breath test involving measurement of (13)CO2 in breath samples collected before and after ingestion of rice steamed with (13)C-labelled sodium acetate. Participants, people doing measurements or examinations, and people assessing the outcomes were not blinded to group assignment.. FR and MR in comparison with RF ameliorated postprandial glucose excursion (AUC-15-240 min-glucose: type 2 diabetes, FR 2,326.6 ± 114.7 mmol/l × min, MR 2,257.0 ± 82.3 mmol/l × min, RF 2,475.6 ± 87.2 mmol/l × min [p < 0.05 for FR vs RF and MR vs RF]; healthy, FR 1,419.8 ± 72.3 mmol/l × min, MR 1,389.7 ± 69.4 mmol/l × min, RF 1,483.9 ± 72.8 mmol/l × min) and glucose variability (SD-15-240 min-glucose: type 2 diabetes, FR 1.94 ± 0.22 mmol/l, MR 1.68 ± 0.18 mmol/l, RF 2.77 ± 0.24 mmol/l [p < 0.05 for FR vs RF and MR vs RF]; healthy, FR 0.95 ± 0.21 mmol/l, MR 0.83 ± 0.16 mmol/l, RF 1.18 ± 0.27 mmol/l). FR and MR also enhanced GLP-1 secretion, MR more strongly than FR or RF (AUC-15-240 min-GLP-1: type 2 diabetes, FR 7,123.4 ± 376.3 pmol/l × min, MR 7,743.6 ± 801.4 pmol/l × min, RF 6,189.9 ± 581.3 pmol/l × min [p < 0.05 for FR vs RF and MR vs RF]; healthy, FR 3,977.3 ± 324.6 pmol/l × min, MR 4,897.7 ± 330.7 pmol/l × min, RF 3,747.5 ± 572.6 pmol/l × min [p < 0.05 for MR vs RF and MR vs FR]). FR and MR delayed gastric emptying (Time50%: type 2 diabetes, FR 83.2 ± 7.2 min, MR 82.3 ± 6.4 min, RF 29.8 ± 3.9 min [p < 0.05 for FR vs RF and MR vs RF]; healthy, FR 66.3 ± 5.5 min, MR 74.4 ± 7.6 min, RF 32.4 ± 4.5 min [p < 0.05 for FR vs RF and MR vs RF]), which is associated with amelioration of postprandial glucose excursion (AUC-15-120 min-glucose: type 2 diabetes, r = -0.746, p < 0.05; healthy, r = -0.433, p < 0.05) and glucose variability (SD-15-240 min-glucose: type 2 diabetes, r = -0.578, p < 0.05; healthy, r = -0.526, p < 0.05), as well as with increasing GLP-1 (AUC-15-120 min-GLP-1: type 2 diabetes, r = 0.437, p < 0.05; healthy, r = 0.300, p = 0.107) and glucagon (AUC-15-120 min-glucagon: type 2 diabetes, r = 0.399, p < 0.05; healthy, r = 0.471, p < 0.05). The measured outcomes were comparable between the two randomised groups.. Meal sequence can play a role in postprandial glucose control through both delayed gastric emptying and enhanced incretin secretion. Our findings provide clues for medical nutrition therapy to better prevent and manage type 2 diabetes.. UMIN Clinical Trials Registry UMIN000017434.. Japan Society for Promotion of Science, Japan Association for Diabetes Education and Care, and Japan Vascular Disease Research Foundation. Topics: Adult; Aged; C-Peptide; Cross-Over Studies; Diabetes Mellitus, Type 2; Diet; Female; Gastric Inhibitory Polypeptide; Glucagon; Glucagon-Like Peptide 1; Glucose; Humans; Incretins; Insulin; Japan; Male; Meals; Middle Aged; Postprandial Period | 2016 |
Diabetic and nondiabetic patients with nonalcoholic fatty liver disease have an impaired incretin effect and fasting hyperglucagonaemia.
We evaluated whether patients with histologically verified nonalcoholic fatty liver disease (NAFLD) have an impaired incretin effect and hyperglucagonaemia.. Four groups matched for age, sex and body mass index were studied: (i) 10 patients with normal glucose tolerance and NAFLD; (ii) 10 patients with type 2 diabetes and NAFLD; (iii) eight patients with type 2 diabetes and no liver disease; and (iv) 10 controls. All participants underwent a 50-g oral glucose tolerance test (OGTT) and an isoglycaemic intravenous glucose infusion (IIGI). We determined the incretin effect by relating the beta cell secretory responses during the OGTT and IIGI. Data are presented as medians (interquartile range), and the groups were compared by using the Kruskal-Wallis test.. Controls exhibited a higher incretin effect [55% (43-73%)] compared with the remaining three groups (P < 0.001): 39% (44-71%) in the nondiabetic NAFLD patients, 20% (-5-50%) in NAFLD patients with type 2 diabetes, and 2% (-8-6%) in patients with type 2 diabetes and no liver disease. We found fasting hyperglucagonaemia in NAFLD patients with [7.5 pmol L(-1) (6.8-15 pmol L(-1))] and without diabetes [7.5 pmol L(-1) (5.0-8.0 pmol L(-1))]. Fasting glucagon levels were lower but similar in patients with type 2 diabetes and no liver disease [4.5 pmol L(-1) (3.0-6.0 pmol L(-1))] and controls [3.4 pmol L(-1) (1.8-6.0 pmol L(-1) )]. All groups had similar glucagon-like peptide-1 and glucose-dependent insulinotropic polypeptide responses.. Patients with NAFLD have a reduced incretin effect and fasting hyperglucagonaemia, with the latter occurring independently of glucose (in)tolerance. Topics: Adult; Blood Glucose; C-Reactive Protein; Diabetes Mellitus, Type 2; Fasting; Female; Gastric Inhibitory Polypeptide; Glucagon; Glucagon-Like Peptide 1; Glucose Intolerance; Humans; Incretins; Insulin; Male; Middle Aged; Non-alcoholic Fatty Liver Disease | 2016 |
A Protein Preload Enhances the Glucose-Lowering Efficacy of Vildagliptin in Type 2 Diabetes.
Nutrient "preloads" given before meals can attenuate postprandial glycemic excursions, at least partly by slowing gastric emptying and stimulating secretion of the incretins (i.e., glucagon-like peptide-1 [GLP-1] and glucose-dependent insulinotropic polypeptide [GIP]). This study was designed to evaluate whether a protein preload could improve the efficacy of the dipeptidyl peptidase-4 (DPP-4) inhibitor vildagliptin to increase incretin concentrations, slow gastric emptying, and lower postprandial glycemia in type 2 diabetes.. Twenty-two patients with type 2 diabetes treated with metformin were studied on four occasions, receiving either 50 mg vildagliptin (VILD) or placebo (PLBO) on both the evening before and the morning of each study day. The latter dose was followed after 60 min by a preload drink containing either 25 g whey protein (WHEY) or control flavoring (CTRL), and after another 30 min by a (13)C-octanoate-labeled mashed potato meal. Plasma glucose and hormones, and gastric emptying, were evaluated.. Compared with PLBO/CTRL, PLBO/WHEY reduced postprandial peak glycemia, increased plasma insulin, glucagon, and incretin hormones (total and intact), and slowed gastric emptying, whereas VILD/CTRL reduced both the peak and area under the curve for glucose, increased plasma intact incretins, and slowed gastric emptying but suppressed plasma glucagon and total incretins (P < 0.05 each). Compared with both PLBO/WHEY and VILD/CTRL, VILD/WHEY was associated with higher plasma intact GLP-1 and GIP, slower gastric emptying, and lower postprandial glycemia (P < 0.05 each).. In metformin-treated type 2 diabetes, a protein preload has the capacity to enhance the efficacy of vildagliptin to slow gastric emptying, increase plasma intact incretins, and reduce postprandial glycemia. Topics: Adamantane; Aged; Blood Glucose; Diabetes Mellitus, Type 2; Dipeptidyl-Peptidase IV Inhibitors; Double-Blind Method; Gastric Emptying; Gastric Inhibitory Polypeptide; Glucagon; Glucagon-Like Peptide 1; Humans; Hypoglycemic Agents; Incretins; Insulin; Male; Metformin; Middle Aged; Nitriles; Postprandial Period; Pyrrolidines; Vildagliptin; Whey Proteins | 2016 |
GLP-1 receptors exist in the parietal cortex, hypothalamus and medulla of human brains and the GLP-1 analogue liraglutide alters brain activity related to highly desirable food cues in individuals with diabetes: a crossover, randomised, placebo-controlled
Liraglutide is a glucagon-like peptide-1 (GLP-1) analogue that has been demonstrated to successfully treat diabetes and promote weight loss. The mechanisms by which liraglutide confers weight loss remain to be fully clarified. Thus, we investigated whether GLP-1 receptors are expressed in human brains and whether liraglutide administration affects neural responses to food cues in diabetic individuals (primary outcome).. In 22 consecutively studied human brains, expression of GLP-1 receptors in the hypothalamus, medulla oblongata and parietal cortex was examined using immunohistochemistry. In a randomised (assigned by the pharmacy using a randomisation enrolment table), placebo-controlled, double-blind, crossover trial, 21 individuals with type 2 diabetes (18 included in analysis due to lack or poor quality of data) were treated with placebo and liraglutide for a total of 17 days each (0.6 mg for 7 days, 1.2 mg for 7 days, and 1.8 mg for 3 days). Participants were eligible if they had type 2 diabetes and were currently being treated with lifestyle changes or metformin. Participants, caregivers, people doing measurements and/or examinations, and people assessing the outcomes were blinded to the medication assignment. We studied metabolic changes as well as neurocognitive and neuroimaging (functional MRI) of responses to food cues at the clinical research centre of Beth Israel Deaconess Medical Center.. Immunohistochemical analysis revealed the presence of GLP-1 receptors on neurons in the human hypothalamus, medulla and parietal cortex. Liraglutide decreased activation of the parietal cortex in response to highly desirable (vs less desirable) food images (p < 0.001; effect size: placebo 0.53 ± 0.24, liraglutide -0.47 ± 0.18). No significant adverse effects were noted. In a secondary analysis, we observed decreased activation in the insula and putamen, areas involved in the reward system. Furthermore, we showed that increased ratings of hunger and appetite correlated with increased brain activation in response to highly desirable food cues while on liraglutide, while ratings of nausea correlated with decreased brain activation.. For the first time, we demonstrate the presence of GLP-1 receptors in human brains. We also observe that liraglutide alters brain activity related to highly desirable food cues. Our data point to a central mechanism contributing to, or underlying, the effects of liraglutide on metabolism and weight loss. Future studies will be needed to confirm and extend these findings in larger samples of diabetic individuals and/or with the higher doses of liraglutide (3 mg) recently approved for obesity.. ClinicalTrials.gov NCT01562678 FUNDING : The study was funded by Novo Nordisk, NIH UL1 RR025758 and 5T32HD052961. Topics: Adult; Aged; Aged, 80 and over; Blood Glucose; Brain; Cross-Over Studies; Diabetes Mellitus, Type 2; Double-Blind Method; Female; Glucagon-Like Peptide 1; Glucagon-Like Peptide-1 Receptor; Humans; Hypoglycemic Agents; Hypothalamus; Liraglutide; Magnetic Resonance Imaging; Male; Medulla Oblongata; Middle Aged | 2016 |
Improving Effect of the Acute Administration of Dietary Fiber-Enriched Cereals on Blood Glucose Levels and Gut Hormone Secretion.
Dietary fiber improves hyperglycemia in patients with type 2 diabetes through its physicochemical properties and possible modulation of gut hormone secretion, such as glucagon-like peptide 1 (GLP-1). We assessed the effect of dietary fiber-enriched cereal flakes (DC) on postprandial hyperglycemia and gut hormone secretion in patients with type 2 diabetes. Thirteen participants ate isocaloric meals based on either DC or conventional cereal flakes (CC) in a crossover design. DC or CC was provided for dinner, night snack on day 1 and breakfast on day 2, followed by a high-fat lunch. On day 2, the levels of plasma glucose, GLP-1, glucose-dependent insulinotropic polypeptide (GIP), and insulin were measured. Compared to CC, DC intake exhibited a lower post-breakfast 2-hours glucose level (198.5±12.8 vs. 245.9±15.2 mg/dL, P<0.05) and a lower incremental peak of glucose from baseline (101.8±9.1 vs. 140.3±14.3 mg/dL, P<0.001). The incremental area under the curve (iAUC) of glucose after breakfast was lower with DC than with CC (P<0.001). However, there were no differences in the plasma insulin, glucagon, GLP-1, and GIP levels. In conclusion, acute administration of DC attenuates postprandial hyperglycemia without any significant change in the representative glucose-regulating hormones in patients with type 2 diabetes (ClinicalTrials.gov. NCT 01997281). Topics: Adult; Aged; Area Under Curve; Blood Glucose; Cross-Over Studies; Diabetes Mellitus, Type 2; Dietary Fiber; Female; Gastric Inhibitory Polypeptide; Glucagon; Glucagon-Like Peptide 1; Glycated Hemoglobin; Humans; Hyperglycemia; Insulin; Intestinal Mucosa; Male; Middle Aged; ROC Curve | 2016 |
Shift to Fatty Substrate Utilization in Response to Sodium-Glucose Cotransporter 2 Inhibition in Subjects Without Diabetes and Patients With Type 2 Diabetes.
Pharmacologically induced glycosuria elicits adaptive responses in glucose homeostasis and hormone release. In type 2 diabetes (T2D), along with decrements in plasma glucose and insulin levels and increments in glucagon release, sodium-glucose cotransporter 2 (SGLT2) inhibitors induce stimulation of endogenous glucose production (EGP) and a suppression of tissue glucose disposal (TGD). We measured fasting and postmeal glucose fluxes in 25 subjects without diabetes using a double glucose tracer technique; in these subjects and in 66 previously reported patients with T2D, we also estimated lipolysis (from [(2)H5]glycerol turnover rate and circulating free fatty acids, glycerol, and triglycerides), lipid oxidation (LOx; by indirect calorimetry), and ketogenesis (from circulating β-hydroxybutyrate concentrations). In both groups, empagliflozin administration raised EGP, lowered TGD, and stimulated lipolysis, LOx, and ketogenesis. The pattern of glycosuria-induced changes was similar in subjects without diabetes and in those with T2D but quantitatively smaller in the former. With chronic (4 weeks) versus acute (first dose) drug administration, glucose flux responses were attenuated, whereas lipid responses were enhanced; in patients with T2D, fasting β-hydroxybutyrate levels rose from 246 ± 288 to 561 ± 596 µmol/L (P < 0.01). We conclude that by shunting substantial amounts of carbohydrate into urine, SGLT2-mediated glycosuria results in a progressive shift in fuel utilization toward fatty substrates. The associated hormonal milieu (lower insulin-to-glucagon ratio) favors glucose release and ketogenesis. Topics: 3-Hydroxybutyric Acid; Algorithms; Benzhydryl Compounds; C-Reactive Protein; Carbohydrate Metabolism; Diabetes Mellitus, Type 2; Energy Metabolism; Glucagon; Glucagon-Like Peptide 1; Glucose Intolerance; Glucosides; Glycosuria; Humans; Hypoglycemic Agents; Insulin; Insulin Secretion; Lipid Metabolism; Lipolysis; Membrane Transport Modulators; Renal Elimination; Sodium-Glucose Transporter 2; Sodium-Glucose Transporter 2 Inhibitors; Time Factors | 2016 |
Pharmacokinetic and Pharmacodynamic Effects of Multiple-dose Administration of Omarigliptin, a Once-weekly Dipeptidyl Peptidase-4 Inhibitor, in Obese Participants With and Without Type 2 Diabetes Mellitus.
Omarigliptin (MK-3102) is a potent, oral, long-acting dipeptidyl peptidase (DPP)-4 inhibitor approved in Japan and in global development as a once-weekly treatment for type 2 diabetes mellitus (T2DM). The aim of this study was to investigate the pharmacokinetic (PK) and pharmacodynamic (PD) effects of omarigliptin in obese participants with and without T2DM.. This was a Phase I, randomized, double-blind, placebo-controlled, multiple-dose study of 50-mg omarigliptin administered once weekly for 4 weeks. Participants included 24 obese but otherwise healthy subjects (panel A; omarigliptin, n = 18; placebo, n = 6) and 8 obese patients with T2DM (treatment naive, hemoglobin A1c ≥ 6.5% and ≤ 10.0% [panel B]; omarigliptin, n = 6; placebo, n = 2). Participants were 45 to 65 years of age with a body mass index of ≥ 30 and ≤ 40 kg/m(2). Blood sampling occurred at select time points, depending on the study panel, to evaluate the PK properties of omarigliptin, DPP-4 activity, active glucagon-like peptide 1 levels, and plasma glucose concentrations. Body weight was an exploratory end point. Due to sparse sampling in panel A, a thorough PK analysis was performed in obese patients with T2DM (panel B) only. PD analyses were performed in the overall study population (pooled panels A and B).. PK profiles in obese participants with and without T2DM were similar to those observed in nonobese reference subjects (historical data). Steady state was achieved after 1 or 2 weekly doses in obese participants with and without T2DM. In obese patients with T2DM, omarigliptin was rapidly absorbed, with a median Tmax of 1 to 2.5 hours (days 1 and 22). Compared with those in reference subjects, the geometric mean ratios (95% CI) (Obese T2DM/reference) for steady-state plasma AUC0-168h, Cmax, and C168h were 0.80 (0.65-0.98), 0.86 (0.53-1.41), and 1.08 (0.88-1.33), respectively. Trough DPP-4 activity was inhibited by ~90%; postprandial (PP) 4-hour weighted mean active GLP-1 concentrations were increased ~2-fold; and PP glucose was significantly reduced with omarigliptin versus placebo in the pooled population. Omarigliptin was generally well-tolerated in the pooled population, and there were no hypoglycemic events. Consistent with other DPP-4 inhibitors, omarigliptin had no effect on body weight in this short-duration study.. The administration of omarigliptin was generally well-tolerated in obese participants with and without T2DM, and the favorable PK and PD profiles support once-weekly dosing. Omarigliptin may provide an important once-weekly treatment option for patients with T2DM. ClinicalTrials.gov identifier: NCT01088711. Topics: Administration, Oral; Aged; Area Under Curve; Blood Glucose; Diabetes Mellitus, Type 2; Dipeptidyl-Peptidase IV Inhibitors; Dose-Response Relationship, Drug; Double-Blind Method; Female; Glucagon-Like Peptide 1; Glycated Hemoglobin; Heterocyclic Compounds, 2-Ring; Humans; Hypoglycemic Agents; Male; Middle Aged; Obesity; Pyrans | 2016 |
Effect of chenodeoxycholic acid and the bile acid sequestrant colesevelam on glucagon-like peptide-1 secretion.
To evaluate the effects of the primary human bile acid, chenodeoxycholic acid (CDCA), and the bile acid sequestrant (BAS) colesevelam, instilled into the stomach, on plasma levels of glucagon-like peptide-1 (GLP-1), glucose-dependent insulinotropic polypeptide, glucose, insulin, C-peptide, glucagon, cholecystokinin and gastrin, as well as on gastric emptying, gallbladder volume, appetite and food intake.. On four separate days, nine patients with type 2 diabetes, and 10 matched healthy control subjects received bolus instillations of (i) CDCA, (ii) colesevelam, (iii) CDCA + colesevelam or (iv) placebo. At baseline and for 180 min after instillation, blood was sampled.. In both the type 2 diabetes group and the healthy control group, CDCA elicited an increase in GLP-1 levels compared with colesevelam, CDCA + colesevelam and placebo, respectively (p < 0.05). The interventions did not affect plasma glucose, insulin or C-peptide concentrations in any of the groups. CDCA elicited a small increase in plasma insulin : glucose ratio compared with colesevelam, CDCA + colesevelam and placebo in both groups. Compared with colesevelam, CDCA + colesevelam and placebo, respectively, CDCA increased glucagon and delayed gastric emptying in both groups.. CDCA increased GLP-1 and glucagon secretion, and delayed gastric emptying. We speculate that bile acid-induced activation of TGR5 on L cells increases GLP-1 secretion, which, in turn, may result in amplification of glucose-stimulated insulin secretion. Furthermore our data suggest that colesevelam does not have an acute effect on GLP-1 secretion in humans. Topics: Aged; Bile Acids and Salts; Blood Glucose; C-Peptide; Chenodeoxycholic Acid; Colesevelam Hydrochloride; Diabetes Mellitus, Type 2; Double-Blind Method; Female; Gastric Emptying; Glucagon-Like Peptide 1; Humans; Incretins; Insulin; Insulin Secretion; Male; Middle Aged; Placebos | 2016 |
GLP-1 Restores Altered Insulin and Glucagon Secretion in Posttransplantation Diabetes.
Development of posttransplantation diabetes (PTDM) is characterized by reduced insulin secretion and sensitivity. We aimed to investigate whether hyperglucagonemia could play a role in PTDM and to examine the insulinotropic and glucagonostatic effects of the incretin hormone glucagon-like peptide 1 (GLP-1) during fasting and hyperglycemic conditions, respectively.. Renal transplant recipients with (n = 12) and without (n = 12) PTDM underwent two separate experimental days with 3-h intravenous infusions of GLP-1 (0.8 pmol/kg/min) and saline, respectively. After 1 h of infusion, a 2-h hyperglycemic clamp (fasting plasma glucose + 5 mmol/L) was established. Five grams of arginine was given as an intravenous bolus 10 min before termination of the clamp.. Fasting concentrations of glucagon (P = 0.92) and insulin (P = 0.23) were similar between the groups. In PTDM patients, glucose-induced glucagon suppression was significantly less pronounced (maximal suppression from baseline: 43 ± 12 vs. 65 ± 12%, P < 0.001), while first- and second-phase insulin secretion were significantly lower. The PTDM group also exhibited a significantly lower insulin response to arginine (P = 0.01) but similar glucagon and proinsulin responses compared with control subjects. In the preclamp phase, GLP-1 lowered fasting plasma glucose to the same extent in both groups but reduced glucagon only in PTDM patients. During hyperglycemic clamp, GLP-1 reduced glucagon concentrations and increased first- and second-phase insulin secretion in both groups.. PTDM is characterized by reduced glucose-induced insulin secretion and attenuated glucagon suppression during a hyperglycemic clamp. Similar to the case in type 2 diabetes, GLP-1 infusion seems to improve (insulin) or even normalize (glucagon) these pathophysiological defects. Topics: Adult; Aged; Blood Glucose; Body Mass Index; Diabetes Mellitus, Type 2; Female; Glucagon; Glucagon-Like Peptide 1; Glycated Hemoglobin; Humans; Incretins; Infusions, Intravenous; Insulin; Insulin Secretion; Kidney Transplantation; Male; Middle Aged; Proinsulin | 2016 |
Comparison of efficacy and safety of taking miglitol dissolved in water during a meal and taking a miglitol tablet just before a meal in patients with type 2 diabetes.
We compared the efficacy and safety of taking miglitol dissolved in water during a meal and taking a miglitol tablet just before a meal. Primary efficacy parameter is the area under the curve (AUC) for postprandial plasma glucose.. Miglitol was administered according to three different intake schedules in each subject: intake schedule A, no miglitol; intake schedule B, administration of miglitol (50 mg) just before breakfast; intake schedule C, dissolving miglitol (50 mg) in water and taking it just before (1/3), during (1/3), and just after breakfast (1/3). Blood samples were collected at 0, 30, 60, 120, and 180 min after breakfast.. The AUCs for plasma glucose, insulin, and total glucose-dependent insulinotropic polypeptide (GIP) were significantly lower for intake schedules B and C, compared with those for intake schedule A. The AUC for total glucagon like peptide-1(GLP-1) was higher for intake schedule C than for intake schedule A. The coefficient of variation (CV) of plasma glucose was significantly lower for intake schedule C than for intake schedules A and B.. Taking miglitol dissolved in water was equivalent to taking a miglitol tablet. The CV of plasma glucose was significantly lower for the dissolved-dose regimen. Topics: 1-Deoxynojirimycin; Blood Glucose; Breakfast; Cross-Over Studies; Diabetes Mellitus, Type 2; Drug Administration Schedule; Female; Gastric Inhibitory Polypeptide; Glucagon-Like Peptide 1; Humans; Hypoglycemic Agents; Insulin; Male; Middle Aged; Postprandial Period; Tablets | 2016 |
Rationale and design of the EXenatide Study of Cardiovascular Event Lowering (EXSCEL) trial.
Exenatide once-weekly is an extended release formulation of exenatide, a glucagon-like peptide-1 receptor agonist, which can improve glycemic control, body weight, blood pressure, and lipid levels in patients with type 2 diabetes mellitus (T2DM). The EXenatide Study of Cardiovascular Event Lowering (EXSCEL) will compare the impact of adding exenatide once-weekly to usual care with usual care alone on major cardiovascular outcomes. EXSCEL is an academically led, phase III/IV, double-blind, pragmatic placebo-controlled, global trial conducted in 35 countries aiming to enrol 14,000 patients with T2DM and a broad range of cardiovascular risk over approximately 5 years. Participants will be randomized (1:1) to receive exenatide once-weekly 2 mg or matching placebo by subcutaneous injections. The trial will continue until 1,360 confirmed primary composite cardiovascular end points, defined as cardiovascular death, nonfatal myocardial infarction, or nonfatal stroke, have occurred. The primary efficacy hypothesis is that exenatide once-weekly is superior to usual care with respect to the primary composite cardiovascular end point. EXSCEL is powered to detect a 15% relative risk reduction in the exenatide once-weekly group, with 85% power and a 2-sided 5% alpha. The primary safety hypothesis is that exenatide once-weekly is noninferior to usual care with respect to the primary cardiovascular composite end point. Noninferiority will be concluded if the upper limit of the CI is <1.30. EXSCEL will assess whether exenatide once-weekly can reduce cardiovascular events in patients with T2DM with a broad range of cardiovascular risk. It will also provide long-term safety information on exenatide once-weekly in people with T2DM. ClinicalTrials.gov Identifier: NCT01144338. Topics: Adult; Aged; Blood Glucose; Cardiovascular Diseases; China; Diabetes Mellitus, Type 2; Dose-Response Relationship, Drug; Double-Blind Method; Drug Administration Schedule; Exenatide; Female; Follow-Up Studies; Glucagon-Like Peptide 1; Glycated Hemoglobin; Humans; Hypoglycemic Agents; Incidence; Injections, Subcutaneous; Italy; Male; Microspheres; Middle Aged; Ontario; Peptides; Prognosis; Risk Assessment; Risk Factors; Survival Rate; Time Factors; United Kingdom; United States; Venoms | 2016 |
Effects of multiple ascending doses of the glucagon receptor antagonist PF-06291874 in patients with type 2 diabetes mellitus.
To assess the pharmacokinetics, pharmacodynamics, safety and tolerability of multiple ascending doses of the glucagon receptor antagonist PF-06291874 in patients with type 2 diabetes mellitus (T2DM).. Patients were randomized to oral PF-06291874 or placebo on a background of either metformin (Part A, Cohorts 1-5: 5-150 mg once daily), or metformin and sulphonylurea (Part B, Cohorts 1-2: 15 or 30 mg once daily) for 14-28 days. A mixed-meal tolerance test (MMTT) was administered on days -1 (baseline), 14 and 28. Assessments were conducted with regard to pharmacokinetics, various pharmacodynamic variables, safety and tolerability. Circulating amino acid concentrations were also measured.. PF-06291874 exposure was approximately dose-proportional with a half-life of ∼19.7-22.7 h. Day 14 fasting plasma glucose and mean daily glucose values were reduced from baseline in a dose-dependent manner, with placebo-corrected decreases of 34.3 and 42.4 mg/dl, respectively, at the 150 mg dose. After the MMTT, dose-dependent increases in glucagon and total glucagon-like peptide-1 (GLP-1) were observed, although no meaningful changes were noted in insulin, C-peptide or active GLP-1 levels. Small dose-dependent increases in LDL cholesterol were observed, along with reversible increases in serum aminotransferases that were largely within the laboratory reference range. An increase in circulating gluconeogenic amino acids was also observed on days 2 and 14. All dose levels of PF-06291874 were well tolerated.. PF-06291874 was well tolerated, has a pharmacokinetic profile suitable for once-daily dosing, and results in reductions in glucose with minimal risk of hypoglycaemia. Topics: Adult; Aged; Alanine Transaminase; Amino Acids; Aspartate Aminotransferases; beta-Alanine; Blood Glucose; C-Peptide; Cholesterol, LDL; Diabetes Mellitus, Type 2; Double-Blind Method; Drug Therapy, Combination; Fasting; Female; Glucagon; Glucagon-Like Peptide 1; Glycated Hemoglobin; Humans; Hypoglycemic Agents; Insulin; Male; Metformin; Middle Aged; Pyrazoles; Receptors, Glucagon; Sulfonylurea Compounds | 2016 |
Weight and Glucose Reduction Observed with a Combination of Nutritional Agents in Rodent Models Does Not Translate to Humans in a Randomized Clinical Trial with Healthy Volunteers and Subjects with Type 2 Diabetes.
Nutritional agents have modest efficacy in reducing weight and blood glucose in animal models and humans, but combinations are less well characterized. GSK2890457 (GSK457) is a combination of 4 nutritional agents, discovered by the systematic assessment of 16 potential components using the diet-induced obese mouse model, which was subsequently evaluated in a human study.. In the diet-induced obese mouse model, GSK457 (15% w/w in chow) given with a long-acting glucagon-like peptide -1 receptor agonist, exendin-4 AlbudAb, produced weight loss of 30.8% after 28 days of treatment. In db/db mice, a model of diabetes, GSK457 (10% w/w) combined with the exendin-4 AlbudAb reduced glucose by 217 mg/dL and HbA1c by 1.2% after 14 days.. GSK457 was evaluated in a 6 week randomized, placebo-controlled study that enrolled healthy subjects and subjects with type 2 diabetes to investigate changes in weight and glucose. In healthy subjects, GSK457 well tolerated when titrated up to 40 g/day, and it reduced systemic exposure of metformin by ~ 30%. In subjects with diabetes taking liraglutide 1.8 mg/day, GSK457 did not reduce weight, but it slightly decreased mean glucose by 0.356 mmol/L (95% CI: -1.409, 0.698) and HbAlc by 0.065% (95% CI: -0.495, 0.365), compared to placebo. In subjects with diabetes taking metformin, weight increased in the GSK457-treated group [adjusted mean % increase from baseline: 1.26% (95% CI: -0.24, 2.75)], and mean glucose and HbA1c were decreased slightly compared to placebo [adjusted mean glucose change from baseline: -1.22 mmol/L (95% CI: -2.45, 0.01); adjusted mean HbA1c change from baseline: -0.219% (95% CI: -0.910, 0.472)].. Our data demonstrate remarkable effects of GSK457 in rodent models of obesity and diabetes, but a marked lack of translation to humans. Caution should be exercised with nutritional agents when predicting human efficacy from rodent models of obesity and diabetes.. ClinicalTrials.gov NCT01725126. Topics: Adolescent; Adult; Aged; Animals; Biological Factors; Blood Glucose; Body Weight; Diabetes Mellitus, Type 2; Female; Glucagon-Like Peptide 1; Healthy Volunteers; Humans; Hypoglycemic Agents; Liraglutide; Male; Metformin; Mice; Mice, Inbred C57BL; Middle Aged; Weight Loss; Young Adult | 2016 |
[Should diabetics have breakfast?].
Topics: Blood Glucose; Breakfast; Cross-Over Studies; Diabetes Mellitus, Type 2; Female; Glucagon-Like Peptide 1; Glycated Hemoglobin; Humans; Hyperglycemia; Insulin; Male; Middle Aged | 2016 |
Comparative evaluation of the therapeutic effect of metformin monotherapy with metformin and acupuncture combined therapy on weight loss and insulin sensitivity in diabetic patients.
Obesity induces insulin resistance (IR), the key etiologic defect of type 2 diabetes mellitus (T2DM). Therefore, an incidence of obesity-induced diabetes is expected to decrease if obesity is controlled. Although Metformin is currently one of the main treatment options for T2DM in obese patients, resulting in an average of 5% weight loss, adequate weight control in all patients cannot be achieved with Metformin alone. Thus, additional therapies with a weight loss effect, such as acupuncture, may improve the effectiveness of Metformin.Subjective:We designed this randomized clinical trial (RCT) to compare the effects of Metformin monotherapy with that of Metformin and acupuncture combined therapy on weight loss and insulin sensitivity among overweight/obese T2DM patients, to understand whether acupuncture plus Metformin is a better approach than Metformin only on treating diabetes. To understand whether acupuncture can be an insulin sensitizer and, if so, its therapeutic mechanism.. Our results show that Metformin and acupuncture combined therapy significantly improves body weight, body mass index (BMI), fasting blood sugar (FBS), fasting insulin (FINS), homeostasis model assessment (HOMA) index, interleukin-6 (IL-6), tumor necrosis factor-α (TNF-α), leptin, adiponectin, glucagon-like peptide-1 (GLP-1), resistin, serotonin, free fatty acids (FFAs), triglyceride (TG), low-density lipoprotein cholesterol (LDLc), high-density lipoprotein cholesterol (HDLc) and ceramides.. Consequently, Metformin and acupuncture combined therapy is more effective than Metformin only, proving that acupuncture is an insulin sensitizer and is able to improve insulin sensitivity possibly by reducing body weight and inflammation, while improving lipid metabolism and adipokines. As a result, electro-acupuncture (EA) might be useful in controlling the ongoing epidemics in obesity and T2DM. Topics: Acupuncture Therapy; Adiponectin; Adult; Biomarkers; Body Mass Index; Body Weight; Cholesterol, HDL; Cholesterol, LDL; Diabetes Mellitus, Type 2; Fatty Acids, Nonesterified; Female; Glucagon-Like Peptide 1; Humans; Insulin; Insulin Resistance; Interleukin-6; Leptin; Male; Metformin; Obesity; Resistin; Serotonin; Triglycerides; Tumor Necrosis Factor-alpha; Weight Loss | 2016 |
Impact of Sleeve Gastrectomy on Type 2 Diabetes Mellitus, Gastric Emptying Time, Glucagon-Like Peptide 1 (GLP-1), Ghrelin and Leptin in Non-morbidly Obese Subjects with BMI 30-35.0 kg/m
The study was conducted to evaluate the impact of laparoscopic sleeve gastrectomy (LSG) on type 2 diabetes mellitus (T2DM) in patients with a body mass index (BMI) of 30.0-35.0 kg/m. Twenty obese patients with T2DM and with a BMI of 30.0-35.0 kg/m. The average duration of follow-up was 17.6 months, and 10 patients had completed 2 years of follow-up. After 2 years, the average BMI decreased from 33.4 ± 1.2 to 26.7 ± 1.8 kg/m. This prospective study confirms the positive impact of LSG on diabetic status of non-morbidly obese patients. The possible mechanisms include the rise in post-prandial GLP-1 level induced by accelerated gastric emptying, leading to an increase in insulin secretion. LSG also leads to decreased ghrelin and leptin levels which may have a role in improving glucose homeostasis after surgery. Topics: Adult; Body Mass Index; Diabetes Mellitus, Type 2; Female; Gastrectomy; Gastric Emptying; Ghrelin; Glucagon-Like Peptide 1; Glycated Hemoglobin; Humans; Insulin; Laparoscopy; Leptin; Male; Middle Aged; Obesity; Treatment Outcome; Young Adult | 2016 |
Quantification of the Contribution of GLP-1 to Mediating Insulinotropic Effects of DPP-4 Inhibition With Vildagliptin in Healthy Subjects and Patients With Type 2 Diabetes Using Exendin [9-39] as a GLP-1 Receptor Antagonist.
We quantified the contribution of GLP-1 as a mediator of the therapeutic effects of dipeptidyl peptidase 4 (DPP-4) inhibition (vildagliptin) by using the GLP-1 receptor antagonist exendin [9-39] in patients with type 2 diabetes and in healthy subjects. Thirty-two patients with type 2 diabetes and 29 age- and weight-matched healthy control subjects were treated in randomized order with 100 mg once daily vildagliptin or placebo for 10 days. Meal tests were performed (days 9 and 10) without and with a high-dose intravenous infusion of exendin [9-39]. The main end point was the ratio of the areas under the curve (AUCs) of integrated insulin secretion rates (total AUCISR) and glucose (total AUCglucose) over 4 h after the meal. Vildagliptin treatment more than doubled responses of intact GLP-1 and glucose-dependent insulinotropic polypeptide and lowered glucose responses without changing AUCISR/AUCglucose in healthy subjects. Vildagliptin significantly increased this ratio by 10.5% in patients with type 2 diabetes, and exendin [9-39] reduced it (both P < 0.0001). The percentage reduction in the AUCISR/AUCglucose ratio achieved with exendin [9-39] was significantly smaller after vildagliptin treatment than after placebo treatment (P = 0.026) and was equivalent to 47 ± 5% of the increments due to vildagliptin. Thus, other mediators appear to contribute significantly to the therapeutic effects of DPP-4 inhibition. Topics: Adamantane; Adult; Aged; Blood Glucose; Diabetes Mellitus, Type 2; Dipeptidyl-Peptidase IV Inhibitors; Female; Gastric Emptying; Gastric Inhibitory Polypeptide; Glucagon-Like Peptide 1; Glucagon-Like Peptide-1 Receptor; Healthy Volunteers; Humans; Hypoglycemic Agents; Insulin; Male; Middle Aged; Nitriles; Peptide Fragments; Pyrrolidines; Vildagliptin | 2016 |
Metabolic responses to xenin-25 are altered in humans with Roux-en-Y gastric bypass surgery.
Xenin-25 (Xen) is a neurotensin-related peptide secreted by a subset of enteroendocrine cells located in the proximal small intestine. Many effects of Xen are mediated by neurotensin receptor-1 on neurons. In healthy humans with normal glucose tolerance (NGT), Xen administration causes diarrhea and inhibits postprandial glucagon-like peptide-1 (GLP-1) release but not insulin secretion. This study determines (i) if Xen has similar effects in humans with Roux-en-Y gastric bypass (RYGB) and (ii) whether neural pathways potentially mediate effects of Xen on glucose homeostasis. Eight females with RYGB and no history of type 2 diabetes received infusions with 0, 4 or 12pmol Xen/kg/min with liquid meals on separate occasions. Plasma glucose and gastrointestinal hormone levels were measured and insulin secretion rates calculated. Pancreatic polypeptide and neuropeptide Y levels were surrogate markers for parasympathetic input to islets and sympathetic tone, respectively. Responses were compared to those in well-matched non-surgical participants with NGT from our earlier study. Xen similarly increased pancreatic polypeptide and neuropeptide Y responses in patients with and without RYGB. In contrast, the ability of Xen to inhibit GLP-1 release and cause diarrhea was severely blunted in patients with RYGB. With RYGB, Xen had no statistically significant effect on glucose, insulin secretory, GLP-1, glucose-dependent insulinotropic peptide, and glucagon responses. However, insulin and glucose-dependent insulinotropic peptide secretion preceded GLP-1 release suggesting circulating GLP-1 does not mediate exaggerated insulin release after RYGB. Thus, Xen has unmasked neural circuits to the distal gut that inhibit GLP-1 secretion, cause diarrhea, and are altered by RYGB. Topics: Adolescent; Adult; Aged; Blood Glucose; Diabetes Mellitus, Type 2; Diarrhea; Female; Gastric Bypass; Gastric Inhibitory Polypeptide; Glucagon; Glucagon-Like Peptide 1; Glucose; Humans; Insulin; Insulin Secretion; Male; Middle Aged; Neuropeptide Y; Neurotensin; Pancreatic Polypeptide | 2016 |
Feedback suppression of meal-induced glucagon-like peptide-1 (GLP-1) secretion mediated through elevations in intact GLP-1 caused by dipeptidyl peptidase-4 inhibition: a randomized, prospective comparison of sitagliptin and vildagliptin treatment.
To compare directly the clinical effects of vildagliptin and sitagliptin in patients with type 2 diabetes, with a special emphasis on incretin hormones and L-cell feedback inhibition induced by dipeptidyl peptidase (DPP-4) inhibition.. A total of 24 patients (12 on a diet/exercise regimen, 12 on metformin) were treated, in randomized order, for 7-9 days, with either vildagliptin (50 mg twice daily = 100 mg/d), sitagliptin (100 mg once daily in those on diet, 50 mg twice daily in those on metformin treatment = 100 mg/d) or placebo (twice daily). A mixed-meal test was performed.. Intact glucagon-like peptide-1 (GLP-1) and glucose-dependent insulinotropic polypeptide concentrations were doubled by both DPP-4 inhibitors. Meal-related total GLP-1 responses were reduced by vildagliptin and sitagliptin treatment alike in the majority of patients (vildagliptin: p = 0.0005; sitagliptin: p = 0.019), but with substantial inter-individual variation. L-cell feedback appeared to be more pronounced in those whose intact GLP-1 relative to total GLP-1 increased more, and who had greater reductions in fasting plasma glucose after DPP-4 inhibition. K-cell feedback inhibition overall was not significant. There were no differences in any of the clinical variables (glycaemia, insulin and glucagon secretory responses) between vildagliptin and sitagliptin treatment.. Vildagliptin and sitagliptin affected incretin hormones, glucose concentrations, insulin and glucagon secretion in a similar manner. Inter-individual variations in L-cell feedback inhibition may indicate heterogeneity in the clinical response to DPP-4 inhibition. Topics: Adamantane; Aged; Combined Modality Therapy; Cross-Over Studies; Diabetes Mellitus, Type 2; Diet, Diabetic; Dipeptidyl-Peptidase IV Inhibitors; Double-Blind Method; Down-Regulation; Drug Administration Schedule; Drug Therapy, Combination; Exercise Therapy; Feedback, Physiological; Female; Glucagon-Like Peptide 1; Humans; Male; Meals; Metformin; Middle Aged; Nitriles; Pyrrolidines; Sitagliptin Phosphate; Vildagliptin | 2016 |
Hormonal Responses to Cholinergic Input Are Different in Humans with and without Type 2 Diabetes Mellitus.
Peripheral muscarinic acetylcholine receptors regulate insulin and glucagon release in rodents but their importance for similar roles in humans is unclear. Bethanechol, an acetylcholine analogue that does not cross the blood-brain barrier, was used to examine the role of peripheral muscarinic signaling on glucose homeostasis in humans with normal glucose tolerance (NGT; n = 10), impaired glucose tolerance (IGT; n = 11), and type 2 diabetes mellitus (T2DM; n = 9). Subjects received four liquid meal tolerance tests, each with a different dose of oral bethanechol (0, 50, 100, or 150 mg) given 60 min before a meal containing acetaminophen. Plasma pancreatic polypeptide (PP), glucose-dependent insulinotropic polypeptide (GIP), glucagon-like peptide-1 (GLP-1), glucose, glucagon, C-peptide, and acetaminophen concentrations were measured. Insulin secretion rates (ISRs) were calculated from C-peptide levels. Acetaminophen and PP concentrations were surrogate markers for gastric emptying and cholinergic input to islets. The 150 mg dose of bethanechol increased the PP response 2-fold only in the IGT group, amplified GLP-1 release in the IGT and T2DM groups, and augmented the GIP response only in the NGT group. However, bethanechol did not alter ISRs or plasma glucose, glucagon, or acetaminophen concentrations in any group. Prior studies showed infusion of xenin-25, an intestinal peptide, delays gastric emptying and reduces GLP-1 release but not ISRs when normalized to plasma glucose levels. Analysis of archived plasma samples from this study showed xenin-25 amplified postprandial PP responses ~4-fold in subjects with NGT, IGT, and T2DM. Thus, increasing postprandial cholinergic input to islets augments insulin secretion in mice but not humans.. ClinicalTrials.gov NCT01434901. Topics: Administration, Oral; Adult; Bethanechol; Blood Glucose; C-Peptide; Cross-Over Studies; Diabetes Mellitus, Type 2; Dose-Response Relationship, Drug; Female; Gastric Emptying; Gastric Inhibitory Polypeptide; Glucagon; Glucagon-Like Peptide 1; Glucose Intolerance; Hormones; Humans; Insulin; Islets of Langerhans; Male; Middle Aged; Muscarinic Agonists; Neurotensin; Non-Randomized Controlled Trials as Topic; Pancreatic Polypeptide; Postprandial Period | 2016 |
Peptide YY and glucagon-like peptide-1 contribute to decreased food intake after Roux-en-Y gastric bypass surgery.
Exaggerated postprandial secretion of glucagon-like peptide-1 (GLP-1) and peptide YY (PYY) may explain appetite reduction and weight loss after Roux-en-Y gastric bypass (RYGB), but causality has not been established. We hypothesized that food intake decreases after surgery through combined actions from GLP-1 and PYY. GLP-1 actions can be blocked using the GLP-1 receptor antagonist Exendin 9-39 (Ex-9), whereas PYY actions can be inhibited by the administration of a dipeptidyl peptidase-4 (DPP-4) inhibitor preventing the formation of PYY. In study 1, food intake decreased by 35% following RYGB compared with before surgery. Before surgery, GLP-1 receptor blockage increased food intake but no effect was seen postoperatively, whereas PYY secretion was markedly increased. In study 2, combined GLP-1 receptor blockage and DPP-4 inhibitor mediated lowering of PYY. Blockade of actions from only one of the two L-cell hormones, GLP-1 and PYY Topics: Appetite; Appetite Regulation; Cross-Over Studies; Denmark; Diabetes Mellitus, Type 2; Eating; Female; Gastric Bypass; Glucagon-Like Peptide 1; Glucagon-Like Peptide-1 Receptor; Humans; Male; Obesity, Morbid; Peptide Fragments; Peptide YY; Treatment Outcome; Weight Loss | 2016 |
Rationale and design of the randomised controlled trial to assess the impact of liraglutide on cardiac function and structure in young adults with type 2 diabetes (the LYDIA study).
The prevalence of type 2 diabetes (T2DM) in younger adults is growing. Compared to the late onset T2DM, it is well recognized that the disease tends to behave more aggressively in the younger age group with evidence of premature micro and macrovasular diseases and shorter life span. This increased mortality is largely attributed to cardiovascular complications. In a recent pilot study, young adults with T2DM were found to have significantly lower peak diastolic strain rate (PEDSR) on cardiac MRI (CMR), a forerunner of diabetic cardiomyopathy. Liraglutide, a glucagon like peptide-1 (GLP-1) analogue, is one of the new classes of glucose lowering therapies licensed to be used in management of T2DM. In randomised controlled trials, liraglutide improves glycaemic control by 1-1.5 % with an added benefit of weight loss of 2-3 kg. In addition, there is emerging evidence elucidating the cardioprotective effects of GLP-1 analogues independent of glycaemic control. In a small study, liraglutide has also been shown to improve cardiac function in patients with coronary ischaemia or congestive heart failure.. This is a prospective, randomised, open-label, blind end-point (PROBE) active-comparator trial. A total of 90 obese eligible participants with T2DM (18-50 years) will be randomised to either liraglutide 1.8 mg once daily or sitagliptin 100 mg once daily for 26 weeks. The primary aim is to assess whether liraglutide improves diastolic function compared to sitagliptin as measured by PEDSR using CMR.. Although newer classes of GLP-1 analogues are made available in recent years, there are very few published studies demonstrating the beneficial effect of GLP-1 analogues on cardiovascular endpoints. In a recently published LEADER study, liraglutide has shown superiority to placebo in a population of type 2 diabetes with high risk of cardiovascular disease. To the best of our knowledge, there are no published studies establishing the effect of liraglutide on cardiac function in younger patients with T2DM on a larger scale. The LYDIA study will comprehensively describe changes in various parameters of cardiac structure and function in patients treated with liraglutide aiming to provide new evidence on effect of liraglutide on diastolic function in young obese people with T2DM. Trial Registration ClinicalTrials.gov identifier: NCT02043054. Topics: Adult; Aged; Cardiovascular Diseases; Diabetes Mellitus, Type 2; Double-Blind Method; Female; Glucagon-Like Peptide 1; Humans; Hypoglycemic Agents; Liraglutide; Male; Middle Aged; Obesity; Pilot Projects; Young Adult | 2016 |
Impact of Diabetes-Specific Nutritional Formulas versus Oatmeal on Postprandial Glucose, Insulin, GLP-1 and Postprandial Lipidemia.
Diabetes-specific nutritional formulas (DSNFs) are frequently used as part of medical nutrition therapy for patients with diabetes. This study aims to evaluate postprandial (PP) effects of 2 DSNFs; Glucerna (GL) and Ultra Glucose Control (UGC) versus oatmeal (OM) on glucose, insulin, glucagon-like peptide-1 (GLP-1), free fatty acids (FFA) and triglycerides (TG). After an overnight fast, 22 overweight/obese patients with type 2 diabetes were given 200 kcal of each of the three meals on three separate days in random order. Blood samples were collected at baseline and at 30, 60, 90, 120, 180 and 240 min. Glucose area under the curve (AUC0-240) after GL and UGC was lower than OM (p < 0.001 for both). Insulin positive AUC0-120 after UGC was higher than after OM (p = 0.02). GLP-1 AUC0-120 and AUC0-240 after GL and UGC was higher than after OM (p < 0.001 for both). FFA and TG levels were not different between meals. Intake of DSNFs improves PP glucose for 4 h in comparison to oatmeal of similar caloric level. This is achieved by either direct stimulation of insulin secretion or indirectly by stimulating GLP-1 secretion. The difference between their effects is probably related to their unique blends of amino acids, carbohydrates and fat. Topics: Aged; Avena; Body Mass Index; Cross-Over Studies; Diabetes Mellitus, Type 2; Diet, Diabetic; Diet, Reducing; Dietary Carbohydrates; Dietary Fats, Unsaturated; Female; Food, Formulated; Glucagon-Like Peptide 1; Glycated Hemoglobin; Glycemic Index; Humans; Hyperglycemia; Hyperinsulinism; Hyperlipidemias; Male; Meals; Middle Aged; Overweight; Seeds | 2016 |
Effects of Liraglutide on Clinical Stability Among Patients With Advanced Heart Failure and Reduced Ejection Fraction: A Randomized Clinical Trial.
Abnormal cardiac metabolism contributes to the pathophysiology of advanced heart failure with reduced left ventricular ejection fraction (LVEF). Glucagon-like peptide 1 (GLP-1) agonists have shown cardioprotective effects in early clinical studies of patients with advanced heart failure, irrespective of type 2 diabetes status.. To test whether therapy with a GLP-1 agonist improves clinical stability following hospitalization for acute heart failure.. Phase 2, double-blind, placebo-controlled randomized clinical trial of patients with established heart failure and reduced LVEF who were recently hospitalized. Patients were enrolled between August 2013 and March 2015 at 24 US sites.. The GLP-1 agonist liraglutide (n = 154) or placebo (n = 146) via a daily subcutaneous injection; study drug was advanced to a dosage of 1.8 mg/d during the first 30 days as tolerated and continued for 180 days.. The primary end point was a global rank score in which all patients, regardless of treatment assignment, were ranked across 3 hierarchical tiers: time to death, time to rehospitalization for heart failure, and time-averaged proportional change in N-terminal pro-B-type natriuretic peptide level from baseline to 180 days. Higher values indicate better health (stability). Exploratory secondary outcomes included primary end point components, cardiac structure and function, 6-minute walk distance, quality of life, and combined events.. Among the 300 patients who were randomized (median age, 61 years [interquartile range {IQR}, 52-68 years]; 64 [21%] women; 178 [59%] with type 2 diabetes; median LVEF of 25% [IQR, 19%-33%]; median N-terminal pro-B-type natriuretic peptide level of 2049 pg/mL [IQR, 1054-4235 pg/mL]), 271 completed the study. Compared with placebo, liraglutide had no significant effect on the primary end point (mean rank of 146 for the liraglutide group vs 156 for the placebo group, P = .31). There were no significant between-group differences in the number of deaths (19 [12%] in the liraglutide group vs 16 [11%] in the placebo group; hazard ratio, 1.10 [95% CI, 0.57-2.14]; P = .78) or rehospitalizations for heart failure (63 [41%] vs 50 [34%], respectively; hazard ratio, 1.30 [95% CI, 0.89-1.88]; P = .17) or for the exploratory secondary end points. Prespecified subgroup analyses in patients with diabetes did not reveal any significant between-group differences. The number of investigator-reported hyperglycemic events was 16 (10%) in the liraglutide group vs 27 (18%) in the placebo group and hypoglycemic events were infrequent (2 [1%] vs 4 [3%], respectively).. Among patients recently hospitalized with heart failure and reduced LVEF, the use of liraglutide did not lead to greater posthospitalization clinical stability. These findings do not support the use of liraglutide in this clinical situation.. clinicaltrials.gov Identifier: NCT01800968. Topics: Aged; Diabetes Mellitus, Type 2; Double-Blind Method; Female; Glucagon-Like Peptide 1; Heart Failure; Humans; Hypoglycemic Agents; Liraglutide; Male; Middle Aged; Odds Ratio; Patient Readmission; Quality of Life; Stroke Volume; Treatment Outcome; United States; Ventricular Dysfunction, Left | 2016 |
GLP-1-Based Therapies Have No Microvascular Effects in Type 2 Diabetes Mellitus: An Acute and 12-Week Randomized, Double-Blind, Placebo-Controlled Trial.
To assess the effects of glucagon-like peptide (GLP)-1-based therapies (ie, GLP-1 receptor agonists and dipeptidyl peptidase-4 inhibitors) on microvascular function in patients with type 2 diabetes mellitus.. We studied 57 patients with type 2 diabetes mellitus (mean±SD age: 62.8±6.9 years; body mass index: 31.8±4.1 kg/m(2); HbA1c [glycated hemoglobin] 7.3±0.6%) in an acute and 12-week randomized, placebo-controlled, double-blind trial conducted at the Diabetes Center of the VU University Medical Center. In the acute study, the GLP-1 receptor agonist exenatide (therapeutic concentrations) or placebo (saline 0.9%) was administered intravenously. During the 12-week study, patients received the GLP-1 receptor agonist liraglutide (1.8 mg daily), the dipeptidyl peptidase-4 inhibitor sitagliptin (100 mg daily), or matching placebos. Capillary perfusion was assessed by nailfold skin capillary videomicroscopy and vasomotion by laser Doppler fluxmetry, in the fasting state and after a high-fat mixed meal. In neither study, treatment affected fasting or postprandial capillary perfusion compared with placebo (P>0.05). In the fasting state, acute exenatide infusion increased neurogenic vasomotion domain power, while reducing myogenic domain power (both P<0.05). After the meal, exenatide increased endothelial domain power (P<0.05). In the 12-week study, no effects on vasomotion were observed.. Despite modest changes in vasomotion, suggestive of sympathetic nervous system activation and improved endothelial function, acute exenatide infusion does not affect skin capillary perfusion in type 2 diabetes mellitus. Twelve-week treatment with liraglutide or sitagliptin has no effect on capillary perfusion or vasomotion in these patients. Our data suggest that the effects of GLP-1-based therapies on glucose are not mediated through microvascular responses. Topics: Adult; Aged; Blood Flow Velocity; Blood Glucose; Diabetes Mellitus, Type 2; Dipeptidyl Peptidase 4; Dipeptidyl-Peptidase IV Inhibitors; Double-Blind Method; Exenatide; Female; Glucagon-Like Peptide 1; Glucagon-Like Peptide-1 Receptor; Glycated Hemoglobin; Humans; Incretins; Laser-Doppler Flowmetry; Liraglutide; Male; Microcirculation; Microscopic Angioscopy; Microscopy, Video; Microvessels; Middle Aged; Netherlands; Peptides; Regional Blood Flow; Signal Transduction; Sitagliptin Phosphate; Skin; Time Factors; Treatment Outcome; Venoms | 2016 |
Calorie restriction and not glucagon-like peptide-1 explains the acute improvement in glucose control after gastric bypass in Type 2 diabetes.
To compare directly the impact of glucagon-like peptide-1 secretion on glucose metabolism in individuals with Type 2 diabetes listed for Roux-en-Y gastric bypass surgery, randomized to be studied before and 7 days after undergoing Roux-en-Y gastric bypass or after following a very-low-calorie diet.. A semi-solid meal test was used to investigate glucose, insulin and glucagon-like peptide-1 response. Insulin secretion in response to intravenous glucose and arginine stimulus was measured. Hepatic and pancreatic fat content was quantified using magnetic resonance imaging.. The decrease in fat mass was almost identical in the Roux-en-Y gastric bypass and the very-low-calorie diet groups (3.0±0.3 and 3.0±0.7kg). The early rise in plasma glucose level and in acute insulin secretion were greater after Roux-en-Y gastric bypass than after a very-low-calorie diet; however, the early rise in glucagon-like peptide-1 was disproportionately greater (sevenfold) after Roux-en-Y gastric bypass than after a very-low-calorie diet. This did not translate into a greater improvement in fasting glucose level or area under the curve for glucose. The reduction in liver fat was greater after Roux-en-Y gastric bypass (29.8±3.7 vs 18.6±4.0%) and the relationships between weight loss and reduction in liver fat differed between the Roux-en-Y gastric bypass group and the very-low-calorie diet group.. This study shows that gastroenterostomy increases the rate of nutrient absorption, bringing about a commensurately rapid rise in insulin level; however, there was no association with the large post-meal rise in glucagon-like peptide-1, and post-meal glucose homeostasis was similar in the Roux-en-Y gastric bypass and very-low-calorie diet groups. (Clinical trials registry number: ISRCTN11969319.). Topics: Adipose Tissue; Adult; Aged; Amino Acids; Arginine; Blood Glucose; Body Composition; Caloric Restriction; Chromium; Diabetes Mellitus, Type 2; Female; Gastric Bypass; Glucagon-Like Peptide 1; Glucose; Glycated Hemoglobin; Humans; Insulin; Insulin Resistance; Insulin Secretion; Lipase; Liver; Male; Membrane Proteins; Middle Aged; Nicotinic Acids; Pancreas; Triglycerides | 2016 |
Semaglutide and Cardiovascular Outcomes in Patients with Type 2 Diabetes.
Regulatory guidance specifies the need to establish cardiovascular safety of new diabetes therapies in patients with type 2 diabetes in order to rule out excess cardiovascular risk. The cardiovascular effects of semaglutide, a glucagon-like peptide 1 analogue with an extended half-life of approximately 1 week, in type 2 diabetes are unknown.. We randomly assigned 3297 patients with type 2 diabetes who were on a standard-care regimen to receive once-weekly semaglutide (0.5 mg or 1.0 mg) or placebo for 104 weeks. The primary composite outcome was the first occurrence of cardiovascular death, nonfatal myocardial infarction, or nonfatal stroke. We hypothesized that semaglutide would be noninferior to placebo for the primary outcome. The noninferiority margin was 1.8 for the upper boundary of the 95% confidence interval of the hazard ratio.. At baseline, 2735 of the patients (83.0%) had established cardiovascular disease, chronic kidney disease, or both. The primary outcome occurred in 108 of 1648 patients (6.6%) in the semaglutide group and in 146 of 1649 patients (8.9%) in the placebo group (hazard ratio, 0.74; 95% confidence interval [CI], 0.58 to 0.95; P<0.001 for noninferiority). Nonfatal myocardial infarction occurred in 2.9% of the patients receiving semaglutide and in 3.9% of those receiving placebo (hazard ratio, 0.74; 95% CI, 0.51 to 1.08; P=0.12); nonfatal stroke occurred in 1.6% and 2.7%, respectively (hazard ratio, 0.61; 95% CI, 0.38 to 0.99; P=0.04). Rates of death from cardiovascular causes were similar in the two groups. Rates of new or worsening nephropathy were lower in the semaglutide group, but rates of retinopathy complications (vitreous hemorrhage, blindness, or conditions requiring treatment with an intravitreal agent or photocoagulation) were significantly higher (hazard ratio, 1.76; 95% CI, 1.11 to 2.78; P=0.02). Fewer serious adverse events occurred in the semaglutide group, although more patients discontinued treatment because of adverse events, mainly gastrointestinal.. In patients with type 2 diabetes who were at high cardiovascular risk, the rate of cardiovascular death, nonfatal myocardial infarction, or nonfatal stroke was significantly lower among patients receiving semaglutide than among those receiving placebo, an outcome that confirmed the noninferiority of semaglutide. (Funded by Novo Nordisk; SUSTAIN-6 ClinicalTrials.gov number, NCT01720446 .). Topics: Aged; Cardiovascular Diseases; Diabetes Mellitus, Type 2; Diabetic Nephropathies; Diabetic Retinopathy; Female; Gastrointestinal Diseases; Glucagon-Like Peptide 1; Glucagon-Like Peptides; Glycated Hemoglobin; Humans; Kaplan-Meier Estimate; Male; Middle Aged | 2016 |
Add-on therapy with anagliptin in Japanese patients with type-2 diabetes mellitus treated with metformin and miglitol can maintain higher concentrations of biologically active GLP-1/total GIP and a lower concentration of leptin.
Metformin, α-glucosidase inhibitors (α-GIs), and dipeptidyl peptidase 4 inhibitors (DPP-4Is) reduce hyperglycemia without excessive insulin secretion, and enhance postprandial plasma concentration of glucagon-like peptide-1 (GLP-1) in type-2 diabetes mellitus (T2DM) patients. We assessed add-on therapeutic effects of DPP-4I anagliptin in Japanese T2DM patients treated with metformin, an α-GI miglitol, or both drugs on postprandial responses of GLP-1 and glucose-dependent insulinotropic polypeptide (GIP), and on plasma concentration of the appetite-suppressing hormone leptin. Forty-two Japanese T2DM patients with inadequately controlled disease (HbA1c: 6.5%-8.0%) treated with metformin (n=14), miglitol (n=14) or a combination of the two drugs (n=14) received additional treatment with anagliptin (100mg, p.o., b.i.d.) for 52 weeks. We assessed glycemic control, postprandial responses of GLP-1 and glucose-dependent insulinotropic polypeptide (GIP), and on plasma concentration of leptin in those patients. Add-on therapy with anagliptin for 52 weeks improved glycemic control and increased the area under the curve of biologically active GLP-1 concentration without altering obesity indicators. Total GIP concentration at 52 weeks was reduced by add-on therapy in groups treated with miglitol compared with those treated with metformin. Add-on therapy reduced leptin concentrations. Add-on therapy with anagliptin in Japanese T2DM patients treated with metformin and miglitol for 52 weeks improved glycemic control and enhanced postprandial concentrations of active GLP-1/total GIP, and reduce the leptin concentration. Topics: 1-Deoxynojirimycin; Aged; Blood Glucose; Diabetes Mellitus, Type 2; Drug Therapy, Combination; Female; Gastric Inhibitory Polypeptide; Glucagon-Like Peptide 1; Humans; Hypoglycemic Agents; Leptin; Male; Metformin; Middle Aged; Pyrimidines; Treatment Outcome | 2016 |
Surgical treatment of type 2 diabetes in subjects with mild obesity: mechanisms underlying metabolic improvements.
This study aims to assess the clinical and physiological effects of Roux-en-Y gastric bypass (RYGBP) on type 2 diabetes associated with mild obesity (body mass index [BMI] 30-34.9 kg/m(2)) over 24 months postsurgery.. In this prospective trial, 36 mildly obese subjects (19 males) with type 2 diabetes using oral antidiabetic drugs with (n = 24) or without insulin (n = 12) underwent RYGBP. Follow-up was conducted at baseline and 3, 6, 12, and 24 months postsurgery. The following endpoints were considered: changes in HbA1c, fasting glucose and insulin, antidiabetic therapy, BMI, oral glucose insulin sensitivity [OGIS, from meal tolerance test (MTT)], beta-cell secretory function [ΔCP(0-30)/ΔGlu(0-30) (ΔC-peptide/Δglucose ratio, MTT 0-30 min), disposition index (DI = OGIS [Symbol: see text] ΔCP(0-30)/ΔGlu(0-30)], glucagon-like peptide (GLP-1) and glucose-dependent insulinotropic polypeptide (GIP) [incremental area under the curve (AUCi)], adiponectin, C-reactive protein, and lipids.. All subjects achieved normal-to-overweight BMI after 3 months. Over 24 months, 31/36 (86 %) subjects presented HbA1c <7 % [complete and partial remission of diabetes in 9/36 (22 %) and 1/36 (3 %), respectively]. Since 3 months postsurgery, improvements were observed in OGIS [290 (174) to 373 (77) ml/min/m(2), P = 0.009], ΔCP(0-30)/ΔGlu(0-30) [0.24 (0.19) to 0.52 (0.34) ng/mg, P = 0.001], DI [7.16 (8.53) to 19.8 (15.4) (ng/mg) (ml/min/m(2)), P = 0.001], GLP-1 AUCi [0.56 (0.64) to 3.97 (3.86) ng/dl [Symbol: see text] 10 min [Symbol: see text] 103, P = 0.000], and GIP AUCi [30.2 (12.6) to 27.0 (20.2) ng/dl [Symbol: see text] 10 min [Symbol: see text] 103, P = 0.004]. At baseline and after 12 months, subjects with diabetes nonremission had longer diabetes duration, higher HbA1c, lower beta-cell secretory function, and higher first 30-min GIP AUCi, compared with those with remission.. RYGBP improves the glucose metabolism in subjects with type 2 diabetes and mild obesity. This effect is associated with improvement of insulin sensitivity, beta-cell secretory function, and incretin secretion. Topics: Adult; Blood Glucose; Body Mass Index; Diabetes Mellitus, Type 2; Female; Gastric Bypass; Glucagon-Like Peptide 1; Glucose Tolerance Test; Humans; Insulin; Insulin Resistance; Male; Middle Aged; Obesity; Severity of Illness Index | 2015 |
Design and methods of a randomised double-blind trial of adding liraglutide to control HbA1c in patients with type 2 diabetes with impaired glycaemic control treated with multiple daily insulin injections (MDI-Liraglutide trial).
Patients with type 2 diabetes are generally treated in primary care setting and as a final treatment step to obtain good glycaemic control, multiple daily insulin injections (MDI) are generally used. The aim of this study is to evaluate the effect of GLP-1 analogue liraglutide on glycaemic control in patients with type 2 diabetes treated with MDI with inadequate glycaemic control.. Overweight and obese patients with type 2 diabetes and impaired glycaemic control treated with MDI were randomised to liraglutide or placebo over 24 weeks. Masked continuous glucose monitoring was performed at baseline and during the trial. The primary endpoint was the change in haemoglobin A1c from baseline to week 24. Additional endpoints include changes in weight, fasting glucose, glycaemic variability, treatment satisfaction, insulin dose, hypoglycaemias, blood pressure and blood lipid levels.. Recruitment occurred between February 2013 and February 2014. A total of 124 patients were randomised. Study completion is anticipated in August 2014.. It is expected that the results of this study will establish whether adding liraglutide to patients with type 2 diabetes treated with MDI will improve glycaemic control, lower body weight, and influence glycaemic variability. Topics: Biomarkers; Blood Glucose; Clinical Protocols; Diabetes Mellitus, Type 2; Double-Blind Method; Drug Administration Schedule; Drug Therapy, Combination; Glucagon-Like Peptide 1; Glycated Hemoglobin; Humans; Hypoglycemic Agents; Incretins; Injections; Insulin; Liraglutide; Patient Selection; Research Design; Sample Size; Sweden; Time Factors; Treatment Outcome | 2015 |
Restoration of the insulinotropic effect of glucose-dependent insulinotropic polypeptide contributes to the antidiabetic effect of dipeptidyl peptidase-4 inhibitors.
To examine whether 12 weeks of treatment with a dipeptidyl peptidase-4 (DPP-4) inhibitor, sitagliptin, influences the insulin secretion induced by glucose, glucose-dependent insulinotropic polypeptide (GIP) and glucagon-like peptide-1 (GLP-1) during a hyperglycaemic clamp in patients with type 2 diabetes (T2DM).. A randomized, double-blind, placebo-controlled study was conducted over 12 weeks, during which 25 patients with T2DM completed treatment with either sitagliptin (100 mg once daily) or placebo as add-on therapy to metformin [sitagliptin group (n = 12): mean ± standard error of the mean (s.e.m.) age 54 ± 2.5 years, mean ± s.e.m. HbA1c 7.8 ± 0.2%; placebo group (n = 13): mean ± s.e.m. age: 57 ± 3.0 years, mean ± s.e.m. HbA1c 7.9 ± 0.2 %]. In weeks 1 and 12, the patients underwent three 2-h 15-mM hyperglycaemic clamp experiments with infusion of either saline, GLP-1 or GIP. β-cell function was evaluated according to first-phase, second-phase, incremental and total insulin and C-peptide responses.. In the sitagliptin group, the mean HbA1c concentration was significantly reduced by 0.9% (p = 0.01). The total β-cell response during GIP infusion improved significantly from week 1 to week 12, both within the sitagliptin group (p = 0.004) and when compared with the placebo group (p = 0.04). The total β-cell response during GLP-1 infusion was significantly higher (p = 0.001) when compared with saline and GIP infusion, but with no improvement from week 1 to week 12. No significant changes in β-cell function occurred in the placebo group.. Treatment with the DPP-4 inhibitor sitagliptin over 12 weeks in patients with T2DM partially restored the lost insulinotropic effect of GIP, whereas the preserved insulinotropic effect of GLP-1 was not further improved. A gradual enhancement of the insulinotropic effect of GIP, therefore, possibly contributes to the antidiabetic actions of DPP-4 inhibitors. Topics: C-Peptide; Diabetes Mellitus, Type 2; Dipeptidyl-Peptidase IV Inhibitors; Double-Blind Method; Drug Therapy, Combination; Female; Gastric Inhibitory Polypeptide; Glucagon-Like Peptide 1; Glucose Clamp Technique; Glycated Hemoglobin; Humans; Hyperglycemia; Hypoglycemic Agents; Insulin; Insulin Secretion; Insulin-Secreting Cells; Male; Metformin; Middle Aged; Pyrazines; Sitagliptin Phosphate; Triazoles; Up-Regulation | 2015 |
Albiglutide does not impair the counter-regulatory hormone response to hypoglycaemia: a randomized, double-blind, placebo-controlled, stepped glucose clamp study in subjects with type 2 diabetes mellitus.
To determine if the glucagon-like peptide-1 (GLP-1) receptor agonist albiglutide, once weekly, impairs counter-regulatory responses during hypoglycaemia.. We conducted a randomized, double-blind, parallel, placebo-controlled study in subjects with type 2 diabetes mellitus. A single dose of albiglutide 50 mg (n = 22) or placebo (n = 22) was administered on day 1. Glucose was clamped on day 4 (to coincide with the approximate albiglutide maximum plasma concentration) at 9.0, 5.0, 4.0, 3.3 and 2.8 mmol/l (162, 90, 72, 59.4 and 50.4 mg/dl), with a post-clamp recovery period to 3.9 mmol/l (70 mg/dl). Hormone measurements were made at each plateau and adverse events (AEs) were recorded.. The counter-regulatory hormones glucagon, epinephrine, norepinephrine, growth hormone and cortisol were appropriately suppressed when plasma glucose levels were >4.0 mmol/l (>72 mg/dl), but increased in the albiglutide and placebo groups with glucose levels <3.3 mmol/l (<59.4 mg/dl) in response to hypoglycaemia. The area under the curve geometric mean ratios (albiglutide : placebo), calculated from the clamped plateau of 4.0 mmol/l (72 mg/dl) to the glucose recovery point, were not significantly different for any of the counter-regulatory hormones. When plasma glucose levels were >5.0 mmol/l (>90 mg/dl), albiglutide increased pancreatic β-cell secretion of C-peptide in a glucose-dependent manner to a greater extent than did placebo, and it was suppressed in each group when levels were <4.0 mmol/l (<72 mg/dl). No significant difference between groups was observed in the recovery time to glucose level ≥3.9 mmol/l (≥70 mg/dl). There were no clinically relevant differences in AEs or other safety variables.. A single 50-mg dose of albiglutide was well tolerated and did not impair the counter-regulatory response to hypoglycaemia. These data provide mechanistic evidence supporting the low intrinsic hypoglycaemic potential of albiglutide. Topics: Adult; Blood Glucose; Diabetes Mellitus, Type 2; Double-Blind Method; Down-Regulation; Female; Glucagon; Glucagon-Like Peptide 1; Glucose Clamp Technique; Humans; Hyperglycemia; Hypoglycemia; Hypoglycemic Agents; Insulin; Insulin Secretion; Male; Middle Aged; Pancreas; Recombinant Proteins; Up-Regulation | 2015 |
Sucralose enhances GLP-1 release and lowers blood glucose in the presence of carbohydrate in healthy subjects but not in patients with type 2 diabetes.
Artificial sweeteners were thought to be metabolically inactive, but after demonstrating that the gustatory mechanism was also localized in the small intestine, suspicions about the metabolic effects of artificial sweeteners have emerged. The objective of this study was to determine the effect of artificial sweeteners (aspartame and sucralose) on blood glucose, insulin, c-peptide and glucagon-like peptide-1 (GLP-1) levels.. Eight newly diagnosed drug-naive type 2 diabetic patients (mean age 51.5±9.2 years; F/M: 4/4) and eight healthy subjects (mean age 45.0±4.1 years; F/M: 4/4) underwent 75 g oral glucose tolerance test (OGTT). During OGTT, glucose, insulin, c-peptide and GLP-1 were measured at 15- min intervals for 120 min. The OGTTs were performed at three settings on different days, where subjects were given 72 mg of aspartame and 24 mg of sucralose in 200 ml of water or 200 ml of water alone 15 min before OGTT in a single-blinded randomized order.. In healthy subjects, the total area under the curve (AUC) of glucose was statistically significantly lower in the sucralose setting than in the water setting (P=0.002). There was no difference between the aspartame setting and the water setting (P=0.53). Total AUC of insulin and c-peptide was similar in aspartame, sucralose and water settings. Total AUC of GLP-1 was significantly higher in the sucralose setting than in the water setting (P=0.04). Total AUC values of glucose, insulin, c-peptide and GLP-1 were not statistically different in three settings in type 2 diabetic patients.. Sucralose enhances GLP-1 release and lowers blood glucose in the presence of carbohydrate in healthy subjects but not in newly diagnosed type 2 diabetic patients. Topics: Adult; Area Under Curve; Aspartame; Blood Glucose; C-Peptide; Diabetes Mellitus, Type 2; Dietary Carbohydrates; Female; Glucagon; Glucagon-Like Peptide 1; Glucose; Glucose Tolerance Test; Healthy Volunteers; Humans; Insulin; Male; Middle Aged; Sucrose; Sweetening Agents | 2015 |
Addition of sitagliptin or metformin to insulin monotherapy improves blood glucose control via different effects on insulin and glucagon secretion in hyperglycemic Japanese patients with type 2 diabetes.
This study aimed to explore the effects of the dipeptidyl peptidase-4 inhibitor sitagliptin and the biguanide metformin on the secretion of insulin and glucagon, as well as incretin levels, in Japanese subjects with type 2 diabetes mellitus poorly controlled with insulin monotherapy. This was a single-center, randomized, open-label, parallel group study, enrolling 25 subjects. Eleven patients (hemoglobin A1c [HbA1c] 8.40 ± 0.96%) and 10 patients (8.10 ± 0.54%) on insulin monotherapy completed 12-week treatment with sitagliptin (50 mg) and metformin (750 mg), respectively. Before and after treatment, each subject underwent a meal tolerance test. The plasma glucose, glucagon-like peptide-1 (GLP-1), glucose-dependent insulinotropic polypeptide (GIP), C-peptide, and glucagon responses to a meal challenge were measured. HbA1c reductions were similar in patients treated with sitagliptin (0.76 ± 0.18%) and metformin (0.77 ± 0.17%). In the sitagliptin group, glucose excursion during a meal tolerance test was reduced and accompanied by elevations in active GLP-1 and active GIP concentrations. C-peptide levels were unaltered despite reduced glucose responses, while glucagon responses were significantly suppressed (-7.93 ± 1.95% of baseline). In the metformin group, glucose excursion and incretin responses were unaltered. C-peptide levels were slightly increased but glucagon responses were unchanged. Our data indicate that sitagliptin and metformin exert different effects on islet hormone secretion in Japanese type 2 diabetic patients on insulin monotherapy. A glucagon suppressing effect of sitagliptin could be one of the factors improving blood glucose control in patients inadequately controlled with insulin therapy. Topics: Aged; Diabetes Mellitus, Type 2; Dipeptidyl-Peptidase IV Inhibitors; Drug Resistance; Drug Therapy, Combination; Female; Gastric Inhibitory Polypeptide; Glucagon; Glucagon-Like Peptide 1; Glucagon-Secreting Cells; Glycated Hemoglobin; Humans; Hyperglycemia; Hypoglycemic Agents; Insulin; Insulin Secretion; Insulin-Secreting Cells; Male; Metformin; Middle Aged; Postprandial Period; Sitagliptin Phosphate | 2015 |
Comparison of insulin glargine and liraglutide added to oral agents in patients with poorly controlled type 2 diabetes.
To compare safety and efficacy of insulin glargine and liraglutide in patients with type 2 diabetes (T2DM).. This randomized, multinational, open-label trial included subjects treated for T2DM with metformin ± sulphonylurea, who had glycated haemoglobin (HbA1c) levels of 7.5-12%. Subjects were assigned to 24 weeks of insulin glargine, titrated to target fasting plasma glucose of 4.0-5.5 mmol/L or liraglutide, escalated to the highest approved clinical dose of 1.8 mg daily. The trial was powered to detect superiority of glargine over liraglutide in percentage of people reaching HbA1c <7%.. The mean [standard deviation (s.d.)] age of the participants was 57 (9) years, the duration of diabetes was 9 (6) years, body mass index was 31.9 (4.2) kg/m(2) and HbA1c level was 9.0 (1.1)%. Equal numbers (n = 489) were allocated to glargine and liraglutide. Similar numbers of subjects in both groups attained an HbA1c level of <7% (48.4 vs. 45.9%); therefore, superiority of glargine over liraglutide was not observed (p = 0.44). Subjects treated with glargine had greater reductions of HbA1c [-1.94% (0.05) and -1.79% (0.05); p = 0.019] and fasting plasma glucose [6.2 (1.6) and 7.9 (2.2) mmol/L; p < 0.001] than those receiving liraglutide. The liraglutide group reported a greater number of gastrointestinal treatment-emergent adverse events (p < 0.001). The mean (s.d.) weight change was +2.0 (4.0) kg for glargine and -3.0 (3.6) kg for liraglutide (p < 0.001). Symptomatic hypoglycaemia was more common with glargine (p < 0.001). A greater number of subjects in the liraglutide arm withdrew as a result of adverse events (p < 0.001).. Adding either insulin glargine or liraglutide to subjects with poorly controlled T2DM reduces HbA1c substantially, with nearly half of subjects reaching target levels of 7%. Topics: Administration, Oral; Aged; Blood Glucose; Body Mass Index; Body Weight; Diabetes Mellitus, Type 2; Drug Therapy, Combination; Female; Glucagon-Like Peptide 1; Glycated Hemoglobin; Humans; Hypoglycemic Agents; Insulin Glargine; Insulin, Long-Acting; International Cooperation; Liraglutide; Male; Metformin; Middle Aged; Treatment Outcome | 2015 |
Liraglutide reduces oxidative stress and restores heme oxygenase-1 and ghrelin levels in patients with type 2 diabetes: a prospective pilot study.
Liraglutide is a glucagon-like peptide-1 analog and glucose-lowering agent whose effects on cardiovascular risk markers have not been fully elucidated.. We evaluated the effect of liraglutide on markers of oxidative stress, heme oxygenase-1 (HO-1), and plasma ghrelin levels in patients with type-2 diabetes mellitus (T2DM).. A prospective pilot study of 2 months' duration has been performed at the Unit of Diabetes and Cardiovascular Prevention at University of Palermo, Italy. Patients and Intervention(s): Twenty subjects with T2DM (10 men and 10 women; mean age: 57 ± 13 y) were treated with liraglutide sc (0.6 mg/d for 2 wk, followed by 1.2 mg/d) in addition to metformin (1500 mg/d orally) for 2 months. Patients with liver disorders or renal failure were excluded.. Plasma ghrelin concentrations, oxidative stress markers, and heat-shock proteins, including HO-1 were assessed.. The addition of liraglutide resulted in a significant decrease in glycated hemoglobin (HbA1c) (8.5 ± 0.4 vs 7.5 ± 0.4%, P < .0001). In addition, plasma ghrelin and glutathione concentrations increased (8.2 ± 4.1 vs 13.6 ± 7.3 pg/ml, P = .0007 and 0.36 ± 0.06 vs 0.44 ± 0.07 nmol/ml, P = .0002, respectively), whereas serum lipid hydroperoxides and HO-1 decreased (0.11 ± 0.05 vs 0.04 ± 0.07 pg/ml, P = .0487 and 7.7 ± 7.7 vs 3.6 ± 1.8 pg/ml, P = .0445, respectively). These changes were not correlated with changes in fasting glycemia or HbA1c.. In a 2-months prospective pilot study, the addition of liraglutide to metformin resulted in improvement in oxidative stress as well as plasma ghrelin and HO-1 concentrations in patients with T2DM. These findings seemed to be independent of the known effects of liraglutide on glucose metabolism. Topics: Adult; Aged; Diabetes Mellitus, Type 2; Drug Therapy, Combination; Female; Ghrelin; Glucagon-Like Peptide 1; Heme Oxygenase-1; Humans; Hypoglycemic Agents; Liraglutide; Male; Metformin; Middle Aged; Oxidative Stress; Pilot Projects; Prospective Studies | 2015 |
Postprandial glucose, insulin and incretin responses to different carbohydrate tolerance tests.
Few studies have focused on postprandial incretin responses to different carbohydrate meals. Therefore, we designed a study to compare the different effects of two carbohydrates (75 g oral glucose, a monosaccharide and 100 g standard noodle, a polysaccharide, with 75 g carbohydrates equivalently) on postprandial glucose, insulin and incretin responses in different glucose tolerance groups.. This study was an open-label, randomized, two-way crossover clinical trial. 240 participants were assigned to take two carbohydrates in a randomized order separated by a washout period of 5-7 days. The plasma glucose, insulin, c-peptide, glucagon and active glucagon-like peptide-1 (AGLP-1) were measured. The incremental area under curve above baseline from 0 to 120 min of insulin (iAUC(0 -120 min)- INS) and AGLP-1(iAUC(0 -120 min)- AGLP-1) was calculated.. Compared with standard noodles, the plasma glucose and insulin after consumption of oral glucose were higher at 30 min (both P < 0.001) and 60 min (both P < 0.001), while lower at 180 min (both P < 0.001), but no differences were found at 120 min. The glucagon at 180 min was higher after consumption of oral glucose (P = 0.010). The AGLP-1 response to oral glucose was higher at 30 min (P < 0.001), 60 min (P < 0.001) and 120 min (P = 0.022), but lower at 180 min (P = 0.027). In normal glucose tolerance (NGT), oral glucose elicited a higher insulin response to the corresponding AGLP-1 (P < 0.001), which was represented by iAUC(0 -120 min) -INS /iAUC(0 -120 min)- AGLP-1, while in type 2 diabetes mellitus (T2DM), standard noodles did (P = 0.001).. Monosaccharide potentiated more rapid and higher glycemic and insulin responses. Oral glucose of liquid state would elicit a more potent release of AGLP-1. The incretin effect was amplified after consumption of standard noodles in T2DM. Topics: Adolescent; Adult; Aged; Biomarkers; Blood Glucose; C-Peptide; China; Cross-Over Studies; Diabetes Mellitus, Type 1; Diabetes Mellitus, Type 2; Dietary Carbohydrates; Female; Glucagon; Glucagon-Like Peptide 1; Glucose Tolerance Test; Humans; Incretins; Insulin; Male; Middle Aged; Postprandial Period; Predictive Value of Tests; Time Factors; Young Adult | 2015 |
Efficacy and tolerability of albiglutide versus placebo or pioglitazone over 1 year in people with type 2 diabetes currently taking metformin and glimepiride: HARMONY 5.
To investigate the efficacy and tolerability of albiglutide, a weekly glucagon-like peptide-1 receptor agonist, when added to metformin and glimepiride in a triple therapy regimen in people with type 2 diabetes mellitus.. This was a 156-week, randomized, double-blind, parallel-group, multicentre study. In the present paper we describe the primary results, namely those at 52 weeks. Adult participants (n = 685) were randomly assigned to albiglutide (30 mg/week), pioglitazone (30 mg/day) or placebo. If needed, blinded uptitration of albiglutide (to 50 mg/week) and pioglitazone (to 45 mg/day) was allowed. The participant's current dose of metformin (>1500 mg/day) was maintained throughout. The glimepiride dose (4 mg/day), standardized before randomization, could be decreased if persistent hypoglycaemia occurred.. The week 52 model-adjusted difference in change of glycated haemoglobin (primary endpoint) for albiglutide versus placebo was -0.87 [95% confidence interval (CI) -1.07, -0.68]%-units (p < 0.001), and for albiglutide versus pioglitazone it was 0.25 (95% CI 0.10, 0.40)%-units; therefore, not non-inferior. In the albiglutide group only, fasting plasma glucose reduced rapidly in the first 2 weeks. Confirmed hypoglycaemia occurred in 14% of participants on albiglutide, 25% on pioglitazone and 14% on placebo. The mean (± standard error) weight change was -0.42 (±0.2) kg with albiglutide, +4.4 (±0.2) kg (p < 0.001) with pioglitazone, and -0.40 (±0.4) kg with placebo and serious adverse events occurred in 6.3, 9.0 and 6.1% of participants in the respective groups. Injection site reactions occurred in 13% of participants on albiglutide and resulted in treatment discontinuation for four participants (1.4%).. Albiglutide, as part of triple therapy, provided effective glucose-lowering and was generally well tolerated. Topics: Blood Glucose; Diabetes Mellitus, Type 2; Dipeptidyl-Peptidase IV Inhibitors; Double-Blind Method; Drug Administration Schedule; Drug Therapy, Combination; Female; Glucagon-Like Peptide 1; Glycated Hemoglobin; Humans; Hypoglycemic Agents; Male; Metformin; Middle Aged; Pioglitazone; Sulfonylurea Compounds; Thiazolidinediones; Treatment Outcome | 2015 |
Liraglutide promotes natriuresis but does not increase circulating levels of atrial natriuretic peptide in hypertensive subjects with type 2 diabetes.
GLP-1 receptor (GLP-1R) agonists induce natriuresis and reduce blood pressure (BP) through incompletely understood mechanisms. We examined the effects of acute and 21-day administration of liraglutide on plasma atrial natriuretic peptide (ANP), urinary sodium excretion, office and 24-h BP, and heart rate (HR).. Liraglutide or placebo was administered for 3 weeks to hypertensive subjects with type 2 diabetes in a double-blinded, randomized, placebo-controlled crossover clinical trial in the ambulatory setting. End points included within-subject change from baseline in plasma ANP, Nt-proBNP, office BP, and HR at baseline and over 4 h following a single dose of liraglutide (0.6 mg) and after 21 days of liraglutide (titrated to 1.8 mg) versus placebo administration. Simultaneous 24-h ambulatory BP and HR monitoring and 24-h urine collections were measured at baseline and following 21 days of treatment.. Plasma ANP levels did not change significantly after acute (+16.72 pg/mL, P = 0.24, 95% CI [-12.1, +45.5] at 2 h) or chronic (-17.42 pg/mL, 95% CI [-36.0, +1.21] at 2 h) liraglutide administration. Liraglutide significantly increased 24-h and nighttime urinary sodium excretion; however, 24-h systolic BP was not significantly different. Small but significant increases in 24-h and nighttime diastolic BP and HR were observed with liraglutide. Body weight, HbA1c, and cholesterol were lower, and office-measured HR was transiently increased (for up to 4 h) with liraglutide administration.. Sustained liraglutide administration for 3 weeks increases urinary sodium excretion independent of changes in ANP or BP in overweight and obese hypertensive patients with type 2 diabetes. Topics: Adult; Aged; Atrial Natriuretic Factor; Blood Pressure; Body Weight; Cross-Over Studies; Diabetes Mellitus, Type 2; Double-Blind Method; Endpoint Determination; Female; Glucagon-Like Peptide 1; Glucagon-Like Peptide-1 Receptor; Heart Rate; Humans; Hypertension; Liraglutide; Male; Middle Aged; Natriuresis; Natriuretic Peptide, Brain; Obesity; Peptide Fragments; Receptors, Glucagon; Sodium | 2015 |
LX4211 therapy reduces postprandial glucose levels in patients with type 2 diabetes mellitus and renal impairment despite low urinary glucose excretion.
We sought to assess the efficacy and safety profile of LX4211, a dual inhibitor of sodium-glucose cotransporter1 (SGLT1) and SGLT2, in patients with type 2 diabetes and renal impairment.. Thirty-one patients with an estimated glomerular filtration rate (eGFR) <60 mL/min/1.73 m(2) were randomly assigned to receive 400 mg of LX4211 or placebo for 7 days. The primary end point was the change from baseline to day 7 in postprandial glucose (PPG) levels. Other end points included changes in fasting plasma glucose levels, glucagon-like peptide 1 levels, urinary glucose excretion (UGE), and blood pressure.. LX4211 therapy significantly reduced PPG levels relative to placebo in the total population and in patients with an eGFR <45 mL/min/1.73 m(2), with a placebo-adjusted decrease in incremental AUCpredose-4 of 73.5 mg·h/dL (P = 0.009) and 137.2 mg·h/dL (P = 0.001) for the total population and the eGFR <45 mL/min/1.73 m(2) subgroup, respectively. There was a significant reduction in fasting plasma glucose levels relative to baseline of -27.1 mg/dL (P < 0.001). Total and active glucagon-like peptide 1 levels were significantly elevated relative to placebo with LX4211 dosing, and UGE was significantly elevated with placebo-subtracted measures of 38.7, 53.5, and 20.4 g/24 h (P ≤ 0.007 for all 3) in the total population, eGFR 45 to 59 mL/min/1.73 m(2), and eGFR <45 mL/min/1.73 m(2) subgroups, respectively.. The PPG effects were maintained in patients with an eGFR <45 mL/min/1.73 m(2) despite the expected reduction in UGE, suggesting that dual SGLT1 and SGLT2 inhibition with LX4211 could prove useful for the treatment of patients with type 2 diabetes and renal impairment. ClinicalTrials.gov identifier: NCT01555008. Topics: Aged; Blood Glucose; Diabetes Mellitus, Type 2; Female; Glucagon-Like Peptide 1; Glycosides; Glycosuria; Humans; Hypoglycemic Agents; Male; Middle Aged; Postprandial Period; Renal Insufficiency | 2015 |
Effect of exogenous intravenous administrations of GLP-1 and/or GIP on circulating pro-atrial natriuretic peptide in subjects with different stages of glucose tolerance.
Topics: Administration, Intravenous; Aged; Atrial Natriuretic Factor; Diabetes Mellitus, Type 2; Female; Gastric Inhibitory Polypeptide; Glucagon-Like Peptide 1; Glucose Intolerance; Humans; Male; Middle Aged; Overweight | 2015 |
Postdinner resistance exercise improves postprandial risk factors more effectively than predinner resistance exercise in patients with type 2 diabetes.
Abnormally elevated postprandial glucose and triacylglycerol (TAG) concentrations are risk factors for cardiovascular disease in type 2 diabetes. The most effective time to exercise to lower postprandial glucose and TAG concentrations is unknown. Thus the aim of this study was to determine what time is more effective, either pre- or postdinner resistance exercise (RE), at improving postprandial risk factors in patients with type 2 diabetes. Thirteen obese patients with type 2 diabetes completed three trials in a random order in which they consumed a dinner meal with 1) no RE (NoRE), 2) predinner RE (RE → M), and 3) postdinner RE beginning 45 min after dinner (M → RE). Clinical outcome measures included postprandial glucose and TAG concentrations. In addition, postprandial acetaminophen (gastric emptying), endocrine responses, free fatty acids, and β-cell function (mathematical modeling) were measured to determine whether these factors were related to changes in glucose and TAG. The TAG incremental area under the curve (iAUC) was ∼92% lower (P ≤ 0.02) during M → RE compared with NoRE and RE → M, an effect due in part to lower very-low-density lipoprotein-1 TAG concentrations. The glucose iAUC was reduced (P = 0.02) by ∼18 and 30% during the RE → M and M → RE trials, respectively, compared with NoRE, with no difference between RE trials. RE → M and M → RE reduced the insulin iAUC by 35 and 48%, respectively, compared with NoRE (P < 0.01). The glucagon-like peptide-1 iAUC was ∼50% lower (P ≤ 0.02) during M → RE compared with NoRE and RE → M. Given that predinner RE only improves postprandial glucose concentrations, whereas postdinner RE improves both postprandial glucose and TAG concentrations, postdinner RE may lower the risk of cardiovascular disease more effectively. Topics: Diabetes Mellitus, Type 2; Exercise; Fatty Acids, Nonesterified; Female; Gastric Emptying; Glucagon-Like Peptide 1; Glucose; Humans; Insulin; Insulin-Secreting Cells; Male; Meals; Middle Aged; Postprandial Period; Risk Factors; Triglycerides | 2015 |
Clinical effectiveness of exenatide in diabetic patients waiting for bariatric surgery.
Bariatric surgery constitutes the most effective treatment for severely obese type 2 diabetic patients. Exenatide is a glucagon-like peptide 1 receptor agonist that can improve glycemic control and cause weight loss in patients with type 2 diabetes. Clinical experience with exenatide in obese patients with type 2 diabetes waiting for bariatric surgery has not been reported. The aim of the study was to evaluate, in clinical practice, weight and metabolic effects of exenatide (after 3 and 6 months) in patients with type 2 diabetes and obesity waiting for bariatric surgery.. A total of 100 diabetic adult subjects with a BMI ≥ 35 kg/m(2) were included. Primary endpoints were changes in weight and HbA1c after 6 months of treatment. Secondary endpoints were changes from baseline of a variety of clinical measures (triglycerides levels, blood pressure, and waist circumference). Data were analyzed at 3 and 6 months of follow-up.. Treatment for 6 months with exenatide decreased significantly body weight (-12.5 kg) and waist circumference (-13 cm). Twenty percent of patients reduced their BMI under 35 kg/m(2) and significantly improved their metabolic profile (HbA1c <7 %). Significant and maintained decreases in HbA1c of 1 % were observed in the 3 and 6 months cohorts. Triglycerides levels and blood pressure also decreased from baseline to the end of the study. Treatment was discontinued in 19 % of patients mainly due to drug inefficacy (6 %) or adverse events (4 %).. Exenatide twice daily (BID) leads to early, robust, and significant weight loss in a subset of patients with diabetes and severe obesity before bariatric surgery. Clinical trials are needed to confirm the benefits of GLP-1 agonists in type 2 diabetic obese patients or high-risk super-obese patients waiting for bariatric surgery. Topics: Adult; Bariatric Surgery; Blood Glucose; Blood Pressure; Diabetes Mellitus, Type 2; Exenatide; Female; Glucagon-Like Peptide 1; Humans; Hypoglycemic Agents; Male; Middle Aged; Obesity, Morbid; Peptides; Prospective Studies; Treatment Outcome; Venoms; Waist Circumference; Weight Loss | 2015 |
Liraglutide reduces the body weight and waist circumference in Chinese overweight and obese type 2 diabetic patients.
To investigate the effects of liraglutide, a glucagon-like peptide-1 (GLP-1) receptor activator, on body weight and waist circumference in Chinese overweight and obese type 2 diabetic patients.. A total of 328 Chinese overweight and obese type 2 diabetic patients were included in this multi-center, open-labeled and self-controlled clinical study. The patients were subcutaneously injected with liraglutide once daily for 24 weeks as add-on therapy to their previous hypoglycemic treatments. Statistical analyses were performed using SPSS software package version 11.5 for Windows.. Liraglutide treatment caused significant reduction of the mean body weight (from 86.61±14.09 to 79.10±13.55 kg) and waist circumference (from 101.81±13.96 to 94.29±14.17 cm), resulting in body weight lose of 5%-10% in 43.67% patients, and body weight loss above 10% in 34.06% patients, who had significant lower plasma creatinine levels. Baseline waist circumference, BMI and HOMA-IR were independently correlated with the body weight loss. Furthermore, liraglutide treatment significantly decreased HbA1c levels (from 8.66%±2.17% to 6.92%±0.95%) with HbA1c<7.0% in 35.37% patients, who had a significantly lower baseline level of HbA1c, but higher baseline levels of C peptide and glucagon. Moreover, liraglutide treatment resulted in greater body weight loss in patients with a long duration of diabetes, and better glycemic control in patients with a short duration of diabetes.. Liraglutide significantly reduces body weight and waist circumference in Chinese overweight and obese type 2 diabetic patients. Patients with apparent visceral obesity, insulin resistance and a long duration of diabetes may have greater body weight loss; whereas patients with high insulin-secreting ability, hyperglucagonemia, and short-duration diabetes may obtain better glycemic control with liraglutide. Topics: Asian People; Body Weight; Diabetes Mellitus, Type 2; Female; Glucagon-Like Peptide 1; Humans; Hypoglycemic Agents; Liraglutide; Male; Middle Aged; Overweight; Waist Circumference | 2015 |
A high-protein breakfast induces greater insulin and glucose-dependent insulinotropic peptide responses to a subsequent lunch meal in individuals with type 2 diabetes.
The previous meal modulates the postprandial glycemic responses to a subsequent meal; this is termed the second-meal phenomenon.. This study examined the effects of high-protein vs. high-carbohydrate breakfast meals on the metabolic and incretin responses after the breakfast and lunch meals.. Twelve type 2 diabetic men and women [age: 21-55 y; body mass index (BMI): 30-40 kg/m(2)] completed two 7-d breakfast conditions consisting of 500-kcal breakfast meals as protein (35% protein/45% carbohydrate) or carbohydrate (15% protein/65% carbohydrate). On day 7, subjects completed an 8-h testing day. After an overnight fast, the subjects consumed their respective breakfast followed by a standard 500-kcal high-carbohydrate lunch meal 4 h later. Blood samples were taken throughout the day for assessment of 4-h postbreakfast and 4-h postlunch total area under the curve (AUC) for glucose, insulin, C-peptide, glucagon, glucose-dependent insulinotropic peptide (GIP), and glucagon-like peptide 1 (GLP-1).. Postbreakfast glucose and GIP AUCs were lower after the protein (17%) vs. after the carbohydrate (23%) condition (P < 0.05), whereas postbreakfast insulin, C-peptide, glucagon, and GLP-1 AUCs were not different between conditions. A protein-rich breakfast may reduce the consequences of hyperglycemia in this population. Postlunch insulin, C-peptide, and GIP AUCs were greater after the protein condition vs. after the carbohydrate condition (second-meal phenomenon; all, P < 0.05), but postlunch AUCs were not different between conditions. The overall glucose, glucagon, and GLP-1 responses (e.g., 8 h) were greater after the protein condition vs. after the carbohydrate condition (all, P < 0.05).. In type 2 diabetic individuals, compared with a high-carbohydrate breakfast, the consumption of a high-protein breakfast meal attenuates the postprandial glucose response and does not magnify the response to the second meal. Insulin, C-peptide, and GIP concentrations demonstrate the second-meal phenomenon and most likely aid in keeping the glucose concentrations controlled in response to the subsequent meal. The trial was registered at www.clinicaltrials.gov/ct2/show/NCT02180646 as NCT02180646. Topics: Adult; Blood Glucose; Body Mass Index; Breakfast; C-Peptide; Cross-Over Studies; Diabetes Mellitus, Type 2; Diet; Diet Records; Dietary Carbohydrates; Dietary Proteins; Energy Intake; Female; Gastric Inhibitory Polypeptide; Glucagon; Glucagon-Like Peptide 1; Humans; Hyperglycemia; Insulin; Lunch; Male; Middle Aged; Postprandial Period; Single-Blind Method; Young Adult | 2015 |
Hyperglycemia potentiates the slowing of gastric emptying induced by exogenous GLP-1.
Acute hyperglycemia markedly slows gastric emptying. Exogenous GLP-1 also slows gastric emptying, leading to diminished glycemic excursions. The primary objective was to determine whether hyperglycemia potentiates the slowing of gastric emptying induced by GLP-1 administration.. Ten healthy participants were studied on 4 separate days. Blood glucose was clamped at hyperglycemia using an intravenous infusion of 25% dextrose (∼12 mmol/L; hyper) on 2 days, or maintained at euglycemia (∼6 mmol/L; eu) on 2 days, between t = -15 and 240 min. During hyperglycemic and euglycemic days, participants received intravenous GLP-1 (1.2 pmol/kg/min) and placebo in a randomized double-blind fashion. At t = 0 min, subjects ingested 100 g beef mince labeled with 20 MBq technetium-99m-sulfur colloid and 3 g 3-O-methyl-glucose (3-OMG), a marker of glucose absorption. Gastric emptying was measured scintigraphically from t = 0 to 240 min and serum 3-OMG taken at regular intervals from t = 15 to 240 min. The areas under the curve for gastric emptying and 3-OMG were analyzed using one-way repeated-measures ANOVA with Bonferroni-Holm adjusted post hoc tests.. Hyperglycemia slowed gastric emptying (eu/placebo vs. hyper/placebo; P < 0.001) as did GLP-1 (eu/placebo vs. eu/GLP-1; P < 0.001). There was an additive effect of GLP-1 and hyperglycemia, such that gastric emptying was markedly slower compared with GLP-1 administration during euglycemia (eu/GLP-1 vs. hyper/GLP-1; P < 0.01).. Acute administration of exogenous GLP-1 profoundly slows gastric emptying during hyperglycemia in excess of the slowing induced by GLP-1 during euglycemia. Studies are required to determine the effects of hyperglycemia on gastric emptying with the subcutaneously administered commercially available GLP-1 agonists in patients with type 2 diabetes. Topics: Aged; Analysis of Variance; Blood Glucose; Diabetes Mellitus, Type 2; Double-Blind Method; Female; Gastric Emptying; Gastrointestinal Agents; Glucagon-Like Peptide 1; Glucose; Healthy Volunteers; Humans; Hyperglycemia; Hypoglycemic Agents; Infusions, Intravenous; Insulin; Male; Middle Aged | 2015 |
L-glutamine and whole protein restore first-phase insulin response and increase glucagon-like peptide-1 in type 2 diabetes patients.
L-glutamine triggers glucagon-like peptide-1 (GLP-1) release from L cells in vitro and when ingested pre-meal, decreases postprandial glycaemia and increases circulating insulin and GLP-1 in type 2 diabetes (T2D) patients. We aimed to evaluate the effect of oral L-glutamine, compared with whole protein low in glutamine, on insulin response in well-controlled T2D patients. In a randomized study with a crossover design, T2D patients (n = 10, 6 men) aged 65.1 ± 5.8, with glycosylated hemoglobin (HbA1c) 6.6% ± 0.7% (48 ± 8 mmol/mol), received oral L-glutamine (25 g), protein (25 g) or water, followed by an intravenous glucose bolus (0.3 g/kg) and hyperglycemic glucose clamp for 2 h. Blood was frequently collected for analyses of glucose, serum insulin and plasma total and active GLP-1 and area under the curve of glucose, insulin, total and active GLP-1 excursions calculated. Treatments were tested 1-2 weeks apart. Both L-glutamine and protein increased first-phase insulin response (p ≤ 0.02). Protein (p = 0.05), but not L-glutamine (p = 0.2), increased second-phase insulin response. Total GLP-1 was increased by both L-glutamine and protein (p ≤ 0.02). We conclude that oral L-glutamine and whole protein are similarly effective in restoring first-phase insulin response in T2D patients. Larger studies are required to further investigate the utility of similar approaches in improving insulin response in diabetes. Topics: Adult; Aged; Blood Glucose; Cross-Over Studies; Diabetes Mellitus, Type 2; Dietary Proteins; Female; Glucagon-Like Peptide 1; Glutamine; Humans; Insulin; Male; Middle Aged | 2015 |
Effect of the glucagon-like peptide-1 analogue liraglutide on coronary microvascular function in patients with type 2 diabetes - a randomized, single-blinded, cross-over pilot study.
Impaired coronary microcirculation is associated with a poor prognosis in patients with type 2 diabetes. In the absence of stenosis of major coronary arteries, coronary flow reserve (CFR) reflects coronary microcirculation. Studies have shown beneficial effects of glucagon-like peptide-1 (GLP-1) on the cardiovascular system. The aim of the study was to explore the short-term effect of GLP-1 treatment on coronary microcirculation estimated by CFR in patients with type 2 diabetes.. Patients with type 2 diabetes and no history of coronary artery disease were treated with either the GLP-1 analogue liraglutide or received no treatment for 10 weeks, in a randomized, single-blinded, cross-over setup with a 2 weeks wash-out period. The effect of liraglutide on coronary microcirculation was evaluated using non-invasive trans-thoracic Doppler-flow echocardiography during dipyridamole induced stress. Peripheral microvascular endothelial function was assessed by Endo-PAT2000®. Interventions were compared by two-sample t-test after ensuring no carry over effect.. A total of 24 patients were included. Twenty patients completed the study (15 male; mean age 57 ± 9; mean BMI 33.1 ± 4.4, mean baseline CFR 2.35 ± 0.45). There was a small increase in CFR following liraglutide treatment (change 0.18, CI95% [-0.01; 0.36], p = 0.06) but no difference in effect in comparison with no treatment (difference between treatment allocation 0.16, CI95% [-0.08; 0.40], p = 0.18). Liraglutide significantly reduced glycated haemoglobin (HbA1c) (-10.1 mmol/mol CI95% [-13.9; -6.4], p = 0.01), systolic blood pressure (-10 mmHg CI95% [-17; -3], p = 0.01) and weight (-1.9 kg CI95% [-3.6; -0.2], p = 0.03) compared to no treatment. There was no effect on peripheral microvascular endothelial function after either intervention.. In this short-term treatment study, 10 weeks of liraglutide treatment had no significant effect on neither coronary nor peripheral microvascular function in patients with type 2 diabetes. Further long-term studies, preferably in patients with more impaired microvascular function and using a higher dosage of GLP-1 analogues, are needed to confirm these findings.. ClinicalTrials.gov: NCT01931982 . Topics: Aged; Coronary Circulation; Cross-Over Studies; Diabetes Mellitus, Type 2; Female; Glucagon-Like Peptide 1; Humans; Hypoglycemic Agents; Liraglutide; Male; Microvessels; Middle Aged; Pilot Projects; Single-Blind Method; Treatment Outcome | 2015 |
Preserved Insulin Secretory Capacity and Weight Loss Are the Predominant Predictors of Glycemic Control in Patients With Type 2 Diabetes Randomized to Roux-en-Y Gastric Bypass.
Improvement in type 2 diabetes after Roux-en-Y gastric bypass (RYGB) has been attributed partly to weight loss, but mechanisms beyond weight loss remain unclear. We performed an ancillary study to the Diabetes Surgery Study to assess changes in incretins, insulin sensitivity, and secretion 1 year after randomization to lifestyle modification and intensive medical management (LS/IMM) alone (n = 34) or in conjunction with RYGB (n = 34). The RYGB group lost more weight and had greater improvement in HbA1c. Fasting glucose was lower after RYGB than after LS/IMM, although the glucose area under the curve decreased comparably for both groups. Insulin sensitivity increased in both groups. Insulin secretion was unchanged after LS/IMM but decreased after RYGB, except for a rapid increase during the first 30 min after meal ingestion. Glucagon-like peptide 1 (GLP-1) was substantially increased after RYGB, while gastric inhibitory polypeptide and glucagon decreased. Lower HbA1c was most strongly correlated with the percentage of weight loss for both groups. At baseline, a greater C-peptide index and 90-min postprandial C-peptide level were predictive of lower HbA1c at 1 year after RYGB. β-Cell glucose sensitivity, which improved only after RYGB, and improved disposition index were associated with lower HbA1c in both groups, independent of weight loss. Weight loss and preserved β-cell function both predominantly determine the greatest glycemic benefit after RYGB. Topics: Adiponectin; Blood Glucose; C-Peptide; Diabetes Mellitus, Type 2; Female; Gastric Bypass; Gastric Inhibitory Polypeptide; Glucagon; Glucagon-Like Peptide 1; Glucagon-Like Peptide 2; Glycated Hemoglobin; Humans; Hypoglycemic Agents; Insulin; Insulin Resistance; Insulin Secretion; Insulin-Secreting Cells; Male; Middle Aged; Obesity; Treatment Outcome; Weight Loss | 2015 |
Postprandial incretin and islet hormone responses and dipeptidyl-peptidase 4 enzymatic activity in patients with maturity onset diabetes of the young.
The role of the incretin hormones in the pathophysiology of maturity onset diabetes of the young (MODY) is unclear.. We studied the postprandial plasma responses of glucagon, incretin hormones (glucagon-like peptide 1 (GLP1) and glucose-dependent insulinotropic polypeptide (GIP)) and dipeptidyl-peptidase 4 (DPP4) enzymatic activity in patients with glucokinase (GCK) diabetes (MODY2) and hepatocyte nuclear factor 1α (HNF1A) diabetes (MODY3) as well as in matched healthy individuals (CTRLs).. Ten patients with MODY2 (mean age ± S.E.M. 43 ± 5 years; BMI 24 ± 2 kg/m(2); fasting plasma glucose (FPG) 7.1 ± 0.3 mmol/l: HbA1c 6.6 ± 0.2%), ten patients with MODY3 (age 31 ± 3 years; BMI 24 ± 1 kg/m(2); FPG 8.9 ± 0.8 mmol/l; HbA1c 7.0 ± 0.3%) and ten CTRLs (age 40 ± 5 years; BMI 24 ± 1 kg/m(2); FPG 5.1 ± 0.1 mmol/l; HbA1c 5.3 ± 0.1%) were examined with a liquid test meal.. All of the groups exhibited similar baseline values of glucagon (MODY2: 7 ± 1 pmol/l; MODY3: 6 ± 1 pmol/l; CTRLs: 8 ± 2 pmol/l, P=0.787), but patients with MODY3 exhibited postprandial hyperglucagonaemia (area under the curve (AUC) 838 ± 108 min × pmol/l) as compared to CTRLs (182 ± 176 min × pmol/l, P=0.005) and tended to have a greater response than did patients with MODY2 (410 ± 154 min × pmol/l, P=0.063). Similar peak concentrations and AUCs for plasma GIP and plasma GLP1 were observed across the groups. Increased fasting DPP4 activity was seen in patients with MODY3 (17.7 ± 1.2 mU/ml) vs CTRLs (13.6 ± 0.8 mU/ml, P=0.011), but the amount of activity was similar to that in patients with MODY2 (15.0 ± 0.7 mU/ml, P=0.133).. The pathophysiology of MODY3 includes exaggerated postprandial glucagon responses and increased fasting DPP4 enzymatic activity but normal postprandial incretin responses both in patients with MODY2 and in patients with MODY3. Topics: Adult; Blood Glucose; Diabetes Mellitus, Type 2; Dipeptidyl Peptidase 4; Fasting; Female; Glucagon; Glucagon-Like Peptide 1; Humans; Incretins; Insulin; Male; Middle Aged; Postprandial Period | 2015 |
Intake of Lactobacillus reuteri improves incretin and insulin secretion in glucose-tolerant humans: a proof of concept.
Ingestion of probiotics can modify gut microbiota and alter insulin resistance and diabetes development in rodents. We hypothesized that daily intake of Lactobacillus reuteri increases insulin sensitivity by changing cytokine release and insulin secretion via modulation of the release of glucagon-like peptides (GLP)-1 and -2.. A prospective, double-blind, randomized trial was performed in 21 glucose-tolerant humans (11 lean: age 49 ± 7 years, BMI 23.6 ± 1.7 kg/m(2); 10 obese: age 51 ± 7 years, BMI 35.5 ± 4.9 kg/m(2)). Participants ingested 10(10) b.i.d. L. reuteri SD5865 or placebo over 4 weeks. Oral glucose tolerance and isoglycemic glucose infusion tests were used to assess incretin effect and GLP-1 and GLP-2 secretion, and euglycemic-hyperinsulinemic clamps with [6,6-(2)H2]glucose were used to measure peripheral insulin sensitivity and endogenous glucose production. Muscle and hepatic lipid contents were assessed by (1)H-magnetic resonance spectroscopy, and immune status, cytokines, and endotoxin were measured with specific assays.. In glucose-tolerant volunteers, daily administration of L. reuteri SD5865 increased glucose-stimulated GLP-1 and GLP-2 release by 76% (P < 0.01) and 43% (P < 0.01), respectively, compared with placebo, along with 49% higher insulin (P < 0.05) and 55% higher C-peptide secretion (P < 0.05). However, the intervention did not alter peripheral and hepatic insulin sensitivity, body mass, ectopic fat content, or circulating cytokines.. Enrichment of gut microbiota with L. reuteri increases insulin secretion, possibly due to augmented incretin release, but does not directly affect insulin sensitivity or body fat distribution. This suggests that oral ingestion of one specific strain may serve as a novel therapeutic approach to improve glucose-dependent insulin release. Topics: Adult; Aged; Blood Glucose; C-Peptide; Diabetes Mellitus, Type 2; Double-Blind Method; Female; Glucagon; Glucagon-Like Peptide 1; Glucagon-Like Peptide 2; Glucose; Glucose Clamp Technique; Glucose Tolerance Test; Humans; Incretins; Insulin; Insulin Resistance; Insulin Secretion; Insulin-Secreting Cells; Limosilactobacillus reuteri; Male; Middle Aged; Obesity; Oxidative Stress; Pilot Projects; Probiotics; Prospective Studies; Protein Precursors | 2015 |
Comparison of effects of sitagliptin and voglibose on left ventricular diastolic dysfunction in patients with type 2 diabetes: results of the 3D trial.
Left ventricular (LV) diastolic dysfunction is frequently observed in patients with type 2 diabetes. Dipeptidyl peptidase-4 inhibitor (DPP-4i) attenuates postprandial hyperglycemia (PPH) and may have cardio-protective effects. It remains unclear whether DPP-4i improves LV diastolic function in patients with type 2 diabetes, and, if so, it is attributable to the attenuation of PPH or to a direct cardiac effect of DPP-4i. We compared the effects of the DPP-4i, sitagliptin, and the alpha-glucosidase inhibitor, voglibose, on LV diastolic function in patients with type 2 diabetes.. We conducted a prospective, randomized, open-label, multicenter study of 100 diabetic patients with LV diastolic dysfunction. Patients received sitagliptin (50 mg/day) or voglibose (0.6 mg/day). The primary endpoints were changes in the e' velocity and E/e' ratio from baseline to 24 weeks later. The secondary efficacy measures included HbA1c, GLP-1, lipid profiles, oxidative stress markers and inflammatory markers.. The study was completed with 40 patients in the sitagliptin group and 40 patients in the voglibose group. There were no significant changes in the e' velocity and E/e' ratio from baseline to 24 weeks later in both groups. However, analysis of covariance demonstrated that pioglitazone use is an independent factor associated with changes in the e' and E/e' ratio. Among patients not using pioglitazone, e' increased and the E/e' ratio decreased in both the sitagliptin and voglibose groups. GLP-1 level increased from baseline to 24 weeks later only in the sitagliptin group (4.8 ± 4.7 vs. 7.3 ± 5.5 pmol/L, p < 0.05). The reductions in HbA1c and body weight were significantly greater in the sitagliptin group than in the voglibose group (-0.7 ± 0.6 % vs. -0.3 ± 0.4, p < 0.005; -1.3 ± 3.2 kg vs. 0.4 ± 2.8 kg, p < 0.05, respectively). There were no changes in lipid profiles and inflammatory markers in both groups.. Our trial showed that sitagliptin reduces HbA1c levels more greatly than voglibose does, but that neither was associated with improvement in the echocardiographic parameters of LV diastolic function in patients with diabetes.. Registered at http://www.umin.ac.jp under UMIN000003784. Topics: Aged; Diabetes Mellitus, Type 2; Diastole; Dipeptidyl-Peptidase IV Inhibitors; Echocardiography; Female; Glucagon-Like Peptide 1; Glycated Hemoglobin; Glycoside Hydrolase Inhibitors; Humans; Inositol; Male; Middle Aged; Sitagliptin Phosphate; Treatment Outcome; Ventricular Dysfunction, Left | 2015 |
Fasting until noon triggers increased postprandial hyperglycemia and impaired insulin response after lunch and dinner in individuals with type 2 diabetes: a randomized clinical trial.
Skipping breakfast has been consistently associated with high HbA1c and postprandial hyperglycemia (PPHG) in patients with type 2 diabetes. Our aim was to explore the effect of skipping breakfast on glycemia after a subsequent isocaloric (700 kcal) lunch and dinner.. In a crossover design, 22 patients with diabetes with a mean diabetes duration of 8.4 ± 0.7 years, age 56.9 ± 1.0 years, BMI 28.2 ± 0.6 kg/m(2), and HbA1c 7.7 ± 0.1% (61 ± 0.8 mmol/mol) were randomly assigned to two test days: one day with breakfast, lunch, and dinner (YesB) and another with lunch and dinner but no breakfast (NoB). Postprandial plasma glucose, insulin, C-peptide, free fatty acids (FFA), glucagon, and intact glucagon-like peptide-1 (iGLP-1) were assessed.. Compared with YesB, lunch area under the curves for 0-180 min (AUC0-180) for plasma glucose, FFA, and glucagon were 36.8, 41.1, and 14.8% higher, respectively, whereas the AUC0-180 for insulin and iGLP-1 were 17% and 19% lower, respectively, on the NoB day (P < 0.0001). Similarly, dinner AUC0-180 for glucose, FFA, and glucagon were 26.6, 29.6, and 11.5% higher, respectively, and AUC0-180 for insulin and iGLP-1 were 7.9% and 16.5% lower on the NoB day compared with the YesB day (P < 0.0001). Furthermore, insulin peak was delayed 30 min after lunch and dinner on the NoB day compared with the YesB day.. Skipping breakfast increases PPHG after lunch and dinner in association with lower iGLP-1 and impaired insulin response. This study shows a long-term influence of breakfast on glucose regulation that persists throughout the day. Breakfast consumption could be a successful strategy for reduction of PPHG in type 2 diabetes. Topics: Adult; Aged; Blood Glucose; Body Mass Index; Breakfast; C-Peptide; Cross-Over Studies; Diabetes Mellitus, Type 2; Fasting; Fatty Acids, Nonesterified; Female; Follow-Up Studies; Glucagon; Glucagon-Like Peptide 1; Glycated Hemoglobin; Humans; Hyperglycemia; Insulin; Lunch; Male; Meals; Middle Aged; Postprandial Period | 2015 |
Glucagon-like peptide-1 protects against ischemic left ventricular dysfunction during hyperglycemia in patients with coronary artery disease and type 2 diabetes mellitus.
Enhancement of myocardial glucose uptake may reduce fatty acid oxidation and improve tolerance to ischemia. Hyperglycemia, in association with hyperinsulinemia, stimulates this metabolic change but may have deleterious effects on left ventricular (LV) function. The incretin hormone, glucagon-like peptide-1 (GLP-1), also has favorable cardiovascular effects, and has emerged as an alternative method of altering myocardial substrate utilization. In patients with coronary artery disease (CAD), we investigated: (1) the effect of a hyperinsulinemic hyperglycemic clamp (HHC) on myocardial performance during dobutamine stress echocardiography (DSE), and (2) whether an infusion of GLP-1(7-36) at the time of HHC protects against ischemic LV dysfunction during DSE in patients with type 2 diabetes mellitus (T2DM).. In study 1, twelve patients underwent two DSEs with tissue Doppler imaging (TDI)-one during the steady-state phase of a HHC. In study 2, ten patients with T2DM underwent two DSEs with TDI during the steady-state phase of a HHC. GLP-1(7-36) was infused intravenously at 1.2 pmol/kg/min during one of the scans. In both studies, global LV function was assessed by ejection fraction and mitral annular systolic velocity, and regional wall LV function was assessed using peak systolic velocity, strain and strain rate from 12 paired non-apical segments.. In study 1, the HHC (compared with control) increased glucose (13.0 ± 1.9 versus 4.8 ± 0.5 mmol/l, p < 0.0001) and insulin (1,212 ± 514 versus 114 ± 47 pmol/l, p = 0.01) concentrations, and reduced FFA levels (249 ± 175 versus 1,001 ± 333 μmol/l, p < 0.0001), but had no net effect on either global or regional LV function. In study 2, GLP-1 enhanced both global (ejection fraction, 77.5 ± 5.0 versus 71.3 ± 4.3%, p = 0.004) and regional (peak systolic strain -18.1 ± 6.6 versus -15.5 ± 5.4%, p < 0.0001) myocardial performance at peak stress and at 30 min recovery. These effects were predominantly driven by a reduction in contractile dysfunction in regions subject to demand ischemia.. In patients with CAD, hyperinsulinemic hyperglycemia has a neutral effect on LV function during DSE. However, GLP-1 at the time of hyperglycemia improves myocardial tolerance to demand ischemia in patients with T2DM.. http://www.isrctn.org . Unique identifier ISRCTN69686930. Topics: Aged; Biomarkers; Biomechanical Phenomena; Blood Glucose; Coronary Artery Disease; Diabetes Mellitus, Type 2; Diabetic Cardiomyopathies; Echocardiography, Doppler, Color; Echocardiography, Stress; Female; Glucagon-Like Peptide 1; Glucose Clamp Technique; Humans; Hyperglycemia; Incretins; Infusions, Intravenous; Insulin; Male; Middle Aged; Myocardial Contraction; Peptide Fragments; Stroke Volume; Ventricular Dysfunction, Left; Ventricular Function, Left | 2015 |
[The efficacy and safety of human glucagon-like peptide-1 analogue liraglutide in newly diagnosed type 2 diabetes with glycosylated hemoglobin A1c > 9].
To evaluate the efficacy and safety of human glucagon-like peptide-1 analogue liraglutide in newly diagnosed type 2 diabetes mellitus (T2DM) with glycosylated hemoglobin A1c (HbA1c) > 9%.. This was an open-labelled, randomized, parallel-group, treat-to-target trial. Newly diagnosed T2DM patients with HbA1c > 9% were enrolled. These patients were treated with metformin with repaglinide and randomized to receive once-daily liraglutide (LIRA, n=25) or the insulin glargine (IGla, n=24) at bedtime. Efficacy and safety were assessed and compared after 18-month treatment.. (1) Compared with the baseline, patients with LIRA had significantly reduced mean body weight,BMI and waist circumference (P < 0.01), whereas, the above indexes were increased (P < 0.01) in patients treated with IGla. (2) After 18 months of treatment, fasting plasma glucose (FPG), 2-hour plasma glucose after a 75g oral glucose load (2hPG) and HbA1c were significantly improved in all patients (P < 0.01), with 2hPG, mean blood glucose (MBG), the largest amplitude of glycemic excursions (LAGE), mean amplitude of glycemic excursions (MAGE) were significantly lower in LIRA group than in IGla group (all P < 0.05). (3) HOMA-IR decreased in both groups (P < 0.05). However, ΔI30/ΔG30, AUCCP180 and Matsuda index were only significantly increased in patients treated with LIRA (respectively, 4.88 ± 1.55 vs 7.60±1.91, 9.23 ± 2.66 vs 13.18 ± 2.72, 39.28 ± 20.35 vs 54.64 ± 23.34, all P < 0.01), while HOMA-IR reduced (4.41 ± 1.58 vs 3.52 ± 1.44, P < 0.05). But in IGla group only HOMA-IR was reduced (4.92 ± 1.84 vs 4.57 ± 1.80, P < 0.05). The index of ΔI30/ΔG30, AUCCP180 and Matsuda index in LIRA group are higher than those of indexes in IGla group(respectively, 7.60 ± 1.91 vs 4.18 ± 1.00, 13.18 ± 2.72 vs 10.53 ± 2.68,54.64 ± 23.34 vs 41.65 ± 17.84, all P < 0.05), while HOMA-IR is lower (3.52 ± 1.44 vs 4.57 ± 1.80, P< 0.05). (4) The rate of HbA1c ≤ 6.5% and the dosages of oral anti-diabetic drugs in LIRA group were significantly better than that in IGla group. (5) No significant differences were observed in hypoglycemic episodes and adverse events between two groups.. It seems that liraglutide is superior to insulin glargine in newly diagnosed T2DM patients with HbA1c > 9% in improving beta-cell function, insulin sensitivity and glucose homeostasis. Topics: Blood Glucose; Diabetes Mellitus, Type 2; Glucagon-Like Peptide 1; Glycated Hemoglobin; Humans; Hypoglycemic Agents; Insulin Glargine; Insulin, Long-Acting; Liraglutide; Metformin; Treatment Outcome | 2015 |
Efficacy of Liraglutide for Weight Loss Among Patients With Type 2 Diabetes: The SCALE Diabetes Randomized Clinical Trial.
Weight loss of 5% to 10% can improve type 2 diabetes and related comorbidities. Few safe, effective weight-management drugs are currently available.. To investigate efficacy and safety of liraglutide vs placebo for weight management in adults with overweight or obesity and type 2 diabetes.. Fifty-six-week randomized (2:1:1), double-blind, placebo-controlled, parallel-group trial with 12-week observational off-drug follow-up period. The study was conducted at 126 sites in 9 countries between June 2011 and January 2013. Of 1361 participants assessed for eligibility, 846 were randomized. Inclusion criteria were body mass index of 27.0 or greater, age 18 years or older, taking 0 to 3 oral hypoglycemic agents (metformin, thiazolidinedione, sulfonylurea) with stable body weight, and glycated hemoglobin level 7.0% to 10.0%.. Once-daily, subcutaneous liraglutide (3.0 mg) (n = 423), liraglutide (1.8 mg) (n = 211), or placebo (n = 212), all as adjunct to 500 kcal/d dietary deficit and increased physical activity (≥150 min/wk).. Three coprimary end points: relative change in weight, proportion of participants losing 5% or more, or more than 10%, of baseline weight at week 56.. Baseline weight was 105.7 kg with liraglutide (3.0-mg dose), 105.8 kg with liraglutide (1.8-mg dose), and 106.5 kg with placebo. Weight loss was 6.0% (6.4 kg) with liraglutide (3.0-mg dose), 4.7% (5.0 kg) with liraglutide (1.8-mg dose), and 2.0% (2.2 kg) with placebo (estimated difference for liraglutide [3.0 mg] vs placebo, -4.00% [95% CI, -5.10% to -2.90%]; liraglutide [1.8 mg] vs placebo, -2.71% [95% CI, -4.00% to -1.42%]; P < .001 for both). Weight loss of 5% or greater occurred in 54.3% with liraglutide (3.0 mg) and 40.4% with liraglutide (1.8 mg) vs 21.4% with placebo (estimated difference for liraglutide [3.0 mg] vs placebo, 32.9% [95% CI, 24.6% to 41.2%]; for liraglutide [1.8 mg] vs placebo, 19.0% [95% CI, 9.1% to 28.8%]; P < .001 for both). Weight loss greater than 10% occurred in 25.2% with liraglutide (3.0 mg) and 15.9% with liraglutide (1.8 mg) vs 6.7% with placebo (estimated difference for liraglutide [3.0 mg] vs placebo, 18.5% [95% CI, 12.7% to 24.4%], P < .001; for liraglutide [1.8 mg] vs placebo, 9.3% [95% CI, 2.7% to 15.8%], P = .006). More gastrointestinal disorders were reported with liraglutide (3.0 mg) vs liraglutide (1.8 mg) and placebo. No pancreatitis was reported.. Among overweight and obese participants with type 2 diabetes, use of subcutaneous liraglutide (3.0 mg) daily, compared with placebo, resulted in weight loss over 56 weeks. Further studies are needed to evaluate longer-term efficacy and safety.. clinicaltrials.gov Identifier:NCT01272232. Topics: Adult; Aged; Body Weight; Diabetes Mellitus, Type 2; Diet, Reducing; Double-Blind Method; Exercise; Female; Glucagon-Like Peptide 1; Humans; Hypoglycemic Agents; Injections, Subcutaneous; Liraglutide; Male; Middle Aged; Obesity; Weight Loss | 2015 |
[Effects of GLP-1 Agonist Exenatide on Cardiac Diastolic Function and Vascular Endothelial Function in Diabetic Patients].
To study the protective effect of glucagon-like peptide-1 (GLP-1) on the left ventricular diastolic function and endothelial function in patients with type 2 diabetes.. 27 patients with type 2 diabetes were randomly divided into two groups: GLP-1 treated group and insulin treated group. Patients in the GLP-1 group were given GLP-1 analogue and metformin hydrochloride. Patients in the insulin group were given insulin and metformin hydrochloride. The outcomes of treatments were measured by fasting plasma glucose (FBG) fasting lipid profile, glycosylated hemoglobin (HbA1c), blood pressure and general clinical features. High resolution Doppler ultrasound was performed to detect mitral early diastolic rapid filling (E-wave), atrial contraction late filling (A-wave), E/A ratio, early diastolic mitral annular velocity (e), late diastolic mitral annular velocity (a), e/a ratio, endothelium-dependent vasodilatation (EDV) mediated by brachial arterial blood flow, and endothelium-independent vasodilatation (EIV) mediated by nitroglycerin.. The levels of FBG and HbA1c decreased significantly in both groups after treatments (P < 0.05). Patients in the GLP-1 group showed improved e, e/a ratio, and E/e ratio after treatments (P < 0.05), but no significant changed in E, A, and E/A ratio (P > 0.05). By contrast, patients in the insulin group showed no significant changes in e, a, E, A, E/A ratio, e/a ratio and E/e ratio after treatments (P > 0.05). EDV increased significantly after treatments in both groups (P < 0.05). A higher level of post-treatment EDV was found in patients in the GLP-1 group compared with those in the insulin group. No significant changes in EIV were found in both groups.. GLP-1 may be able to mitigate the left ventricular diastolic dysfunction and improve endothelial function of patients with type 2 diabetes. Our findings suggest that GLP-1 has the potential to prevent or delay cardiovascular complications in patients with type 2 diabetes. Further studies are needed. Topics: Diabetes Mellitus, Type 2; Diastole; Exenatide; Glucagon-Like Peptide 1; Glycated Hemoglobin; Humans; Hypoglycemic Agents; Insulin; Mitral Valve; Peptides; Vasodilation; Venoms; Ventricular Function, Left | 2015 |
Glucose Variability and β- Cell Response by GLP-1 Analogue added-on CSII for Patients with Poorly Controlled Type 2 Diabetes.
The effects of twice-daily GLP-1 analogue injections added on continuous subcutaneous insulin infusion (CSII) in patients with poorly controlled type 2 diabetes (T2DM) were unknown. After optimization of blood glucose in the first 3 days by CSII during hospitalization, patients with poorly controlled T2DM were randomized to receive CSII combined with injections of exenatide or placebo for another 3 days. A total of 51 patients (30 in exenatide and 21 in placebo groups) with mean A1C 11% were studied. There was no difference in mean glucose but a significant higher standard deviation of plasma glucose (SDPG) was found in the exenatide group (50.51 ± 2.43 vs. 41.49 ± 3.00 mg/dl, p = 0.027). The improvement of incremental area under the curve (AUC) of glucose and insulinogenic index (Insulin 0-peak/ Glucose 0-peak) in 75 g oral glucose tolerance test was prominent in the exenatide group (p < 0.01). The adiponectin level was significantly increased with exenatide added on (0.39 ± 0.32 vs. -1.62 ± 0.97 μg/mL, in exenatide and placebo groups, respectively, p = 0.045). In conclusion, the add-on of GLP-1 analogue to CSII increased glucose variability and the β - cell response in patients with poorly controlled T2DM. Topics: Adiponectin; Biomarkers; Blood Glucose; C-Peptide; Cardiovascular Diseases; Diabetes Mellitus, Type 2; Endpoint Determination; Exenatide; Female; Glucagon-Like Peptide 1; Glucose Tolerance Test; Humans; Injections, Subcutaneous; Insulin; Insulin Infusion Systems; Insulin Resistance; Insulin-Secreting Cells; Male; Middle Aged; Peptides; Risk Factors; Venoms | 2015 |
Diacylglycerol acyltransferase 1 inhibition with AZD7687 alters lipid handling and hormone secretion in the gut with intolerable side effects: a randomized clinical trial.
Inhibition of diacylglycerol acyltransferase 1 (DGAT1) is a potential treatment modality for patients with type 2 diabetes mellitus and obesity, based on preclinical data suggesting it is associated with insulin sensitization and weight loss. This randomized, placebo-controlled, phase 1 study in 62 overweight or obese men explored the effects and tolerability of AZD7687, a reversible and selective DGAT1 inhibitor.. Multiple doses of AZD7687 (1, 2.5, 5, 10 and 20 mg/day, n = 6 or n = 12 for each) or placebo (n = 20) were administered for 1 week. Postprandial serum triacylglycerol (TAG) was measured for 8 h after a standardized 45% fat meal. Glucagon-like peptide-1 (GLP-1) and peptide YY (PYY) were measured and a paracetamol challenge was performed to assess gastric emptying.. Dose-dependent reductions in postprandial serum TAG were demonstrated with AZD7687 doses ≥5 mg compared with placebo (p < 0.01). Significant (p < 0.001) increases in plasma GLP-1 and PYY levels were seen at these doses, but no clear effect on gastric emptying was demonstrated at the end of treatment. With AZD7687 doses >5 mg/day, gastrointestinal (GI) side effects increased; 11/18 of these participants discontinued treatment owing to diarrhoea.. Altered lipid handling and hormone secretion in the gut were demonstrated during 1-week treatment with the DGAT1 inhibitor AZD7687. However, the apparent lack of therapeutic window owing to GI side effects of AZD7687, particularly diarrhoea, makes the utility of DGAT1 inhibition as a novel treatment for diabetes and obesity questionable. Topics: Acetates; Adult; Anti-Obesity Agents; Diabetes Mellitus, Type 2; Diacylglycerol O-Acyltransferase; Diarrhea; Dose-Response Relationship, Drug; Gastric Emptying; Glucagon-Like Peptide 1; Humans; Intestinal Absorption; Male; Middle Aged; Obesity; Peptide YY; Pyrazines; Treatment Outcome; Weight Loss | 2014 |
Restoring Insulin Secretion (RISE): design of studies of β-cell preservation in prediabetes and early type 2 diabetes across the life span.
The Restoring Insulin Secretion (RISE) Consortium is testing interventions designed to preserve or improve β-cell function in prediabetes or early type 2 diabetes.. β-Cell function is measured using hyperglycemic clamps and oral glucose tolerance tests (OGTTs). The adult medication protocol randomizes participants to 12 months of placebo, metformin alone, liraglutide plus metformin, or insulin (3 months) followed by metformin (9 months). The pediatric medication protocol randomizes participants to metformin or insulin followed by metformin. The adult surgical protocol randomizes participants to gastric banding or metformin (24 months). Adult medication protocol inclusion criteria include fasting plasma glucose 95-125 mg/dL (5.3-6.9 mmol/L), OGTT 2-h glucose ≥140 mg/dL (≥7.8 mmol/L), HbA1c 5.8-7.0% (40-53 mmol/mol), and BMI 25-40 kg/m(2). Adult surgical protocol criteria are similar, except for fasting plasma glucose ≥90 mg/dL (≥5.0 mmol/L), BMI 30-40 kg/m(2), HbA1c <7.0% (<53 mmol/mol), and diabetes duration <12 months. Pediatric inclusion criteria include fasting plasma glucose ≥90 mg/dL (≥5.0 mmol/L), 2-h glucose ≥140 mg/dL (≥7.8 mmol/L), HbA1c ≤8.0% (≤64 mmol/mol), BMI >85th percentile and ≤50 kg/m(2), 10-19 years of age, and diabetes <6 months.. Primary outcomes are clamp-derived glucose-stimulated C-peptide secretion and maximal C-peptide response to arginine during hyperglycemia. Measurements are made at baseline, after 12 months on treatment, and 3 months after treatment withdrawal (medication protocols) or 24 months postintervention (surgery protocol). OGTT-derived measures are also obtained at these time points.. RISE is determining whether medication or surgical intervention strategies can mitigate progressive β-cell dysfunction in adults and youth with prediabetes or early type 2 diabetes. Topics: Adolescent; Adult; Aged; Arginine; Blood Glucose; C-Peptide; Child; Diabetes Mellitus, Type 2; Drug Therapy, Combination; Female; Gastroplasty; Glucagon-Like Peptide 1; Glucose Clamp Technique; Glucose Tolerance Test; Humans; Hyperglycemia; Hypoglycemic Agents; Insulin; Insulin Resistance; Insulin Secretion; Insulin-Secreting Cells; Liraglutide; Male; Metformin; Middle Aged; Prediabetic State; Young Adult | 2014 |
Dose response of continuous subcutaneous infusion of recombinant glucagon-like peptide-1 in combination with metformin and sulphonylurea over 12 weeks in patients with type 2 diabetes mellitus.
Any differences observed between natural glucagon-like peptide-1 (GLP-1) and studies obtained with analogues might call for renewed considerations concerning the use and design of such analogues. Thus, we aimed to evaluate the dose-response relationship of recombinant glucagon-like peptide-1 (7-36) amide (rGLP-1) administered by continuous subcutaneous infusion (CSCI) in subjects with type 2 diabetes.. We compared the efficacy and safety of three doses of recombinant GLP-1, ranging from 1.25 to 5.0 pmol/kg/min (pkm) and placebo, given by continuous subcutaneous infusion over 3 months in combination with metformin and sulphonylurea (SU), to lower haemoglobin A1c (HbA1c), fasting plasma glucose and weight in 95 type 2 diabetes patients with inadequate glycaemic control.. The mean decreases in HbA1c at endpoint (week 12) were significantly greater for all three rGLP-1 dose groups when each was compared with the placebo group, with the greatest decrease occurring in the 5.0 pkm dose group (-1.3%, s.d. ± 0.18, p < 0.001). The mean decreases in fasting plasma glucose from baseline to endpoint were significantly greater for all three rGLP-1 dose groups than for the placebo group, with the greatest decrease occurring in the 5.0 pkm dose group (-26.0 mg/dl, s.d. ± 8.5, p = 0.02). Body weight was significantly reduced by 1.8 kg (s.d. ± 1.3) in the 1.25 pkm dose group only (p = 0.04).. Administration of rGLP-1 by CSCI over a 12-week period in combination with metformin and an SU had a dose dependent effect in lowering HbA1c and fasting plasma glucose. However, administration of rGLP-1 by CSCI may be less effective with respect to lowering of body weight compared with the daily and once weekly analogues. Topics: Adult; Aged; Aged, 80 and over; Analysis of Variance; Blood Glucose; Body Weight; Diabetes Mellitus, Type 2; Dose-Response Relationship, Drug; Double-Blind Method; Drug Therapy, Combination; Female; Follow-Up Studies; Glucagon-Like Peptide 1; Glycated Hemoglobin; Humans; Hypoglycemic Agents; Infusions, Subcutaneous; Male; Metformin; Middle Aged; Sulfonylurea Compounds; Time Factors | 2014 |
Defining the role of GLP-1 in the enteroinsulinar axis in type 2 diabetes using DPP-4 inhibition and GLP-1 receptor blockade.
Understanding the incretin pathway has led to significant advancements in the treatment of type 2 diabetes (T2D). Still, the exact mechanisms are not fully understood. In a randomized, placebo-controlled, four-period, crossover study in 24 patients with T2D, dipeptidyl peptidase-4 (DPP-4) inhibition and its glucose-lowering actions were tested after an oral glucose tolerance test (OGTT). The contribution of GLP-1 was examined by infusion of the GLP-1 receptor (GLP-1r) antagonist exendin-9. DPP-4 inhibition reduced glycemia and enhanced insulin levels and the incretin effect (IE). Glucagon was suppressed, and gastric emptying (GE) was decelerated. Exendin-9 increased glucose levels and glucagon secretion, attenuated insulinemia and the IE, and accelerated GE. With the GLP-1r antagonist, the glucose-lowering effects of DPP-4 inhibition were reduced by ∼ 50%. However, a significant effect on insulin secretion remained during GLP-1r blockade, whereas the inhibitory effects of DPP-4 inhibition on glucagon and GE were abolished. Thus, in this cohort of T2D patients with a substantial IE, GLP-1 contributed ∼ 50% to the insulin excursion after an OGTT with and without DPP-4 inhibition. Thus, a significant DPP-4-sensitive glucose-lowering mechanism contributes to glycemic control in T2D patients that may be not mediated by circulating GLP-1. Topics: Blood Glucose; C-Peptide; Cross-Over Studies; Diabetes Mellitus, Type 2; Dipeptidyl-Peptidase IV Inhibitors; Fasting; Female; Gastric Emptying; Glucagon-Like Peptide 1; Glucagon-Like Peptide-1 Receptor; Glucose Tolerance Test; Humans; Incretins; Insulin; Insulin Secretion; Male; Middle Aged; Pyrazines; Receptors, Glucagon; Sitagliptin Phosphate; Triazoles | 2014 |
Differing effects of liraglutide on gastric emptying in Japanese patients with type 2 diabetes.
This study was performed to clarify the influence of liraglutide on gastric emptying in Japanese patients with type 2 diabetes. In 16 patients, the [(13) C]-acetate breath test was performed to compare gastric emptying before and after liraglutide treatment. We found two patterns of response, with gastric emptying being delayed by liraglutide in seven patients (delayers) and not delayed in nine patients (non-delayers). The mean increase of the maximum gastric emptying time was 31 ± 4 min (p < 0.01 vs. baseline) in the delayers, while it was only 2 ± 3 min (p = 0.60 vs. baseline) in the non-delayers. The delayers showed a greater early decrease of AUC-PG from 0 to 60 min, despite no increase of the plasma insulin level compared with non-delayers. In conclusion, the effect of liraglutide treatment on gastric emptying shows heterogeneity, and patients can be classified as delayers or non-delayers. Topics: Adult; Aged; Asian People; Blood Glucose; Breath Tests; Diabetes Mellitus, Type 2; Female; Gastric Emptying; Glucagon-Like Peptide 1; Humans; Hypoglycemic Agents; Liraglutide; Male; Middle Aged; Tachyphylaxis | 2014 |
Xenin-25 delays gastric emptying and reduces postprandial glucose levels in humans with and without type 2 diabetes.
Xenin-25 (Xen) is a neurotensin-related peptide secreted by a subset of glucose-dependent insulinotropic polypeptide (GIP)-producing enteroendocrine cells. In animals, Xen regulates gastrointestinal function and glucose homeostasis, typically by initiating neural relays. However, little is known about Xen action in humans. This study determines whether exogenously administered Xen modulates gastric emptying and/or insulin secretion rates (ISRs) following meal ingestion. Fasted subjects with normal (NGT) or impaired (IGT) glucose tolerance and Type 2 diabetes mellitus (T2DM; n = 10-14 per group) ingested a liquid mixed meal plus acetaminophen (ACM; to assess gastric emptying) at time zero. On separate occasions, a primed-constant intravenous infusion of vehicle or Xen at 4 (Lo-Xen) or 12 (Hi-Xen) pmol · kg(-1) · min(-1) was administered from zero until 300 min. Some subjects with NGT received 30- and 90-min Hi-Xen infusions. Plasma ACM, glucose, insulin, C-peptide, glucagon, Xen, GIP, and glucagon-like peptide-1 (GLP-1) levels were measured and ISRs calculated. Areas under the curves were compared for treatment effects. Infusion with Hi-Xen, but not Lo-Xen, similarly delayed gastric emptying and reduced postprandial glucose levels in all groups. Infusions for 90 or 300 min, but not 30 min, were equally effective. Hi-Xen reduced plasma GLP-1, but not GIP, levels without altering the insulin secretory response to glucose. Intense staining for Xen receptors was detected on PGP9.5-positive nerve fibers in the longitudinal muscle of the human stomach. Thus Xen reduces gastric emptying in humans with and without T2DM, probably via a neural relay. Moreover, endogenous GLP-1 may not be a major enhancer of insulin secretion in healthy humans under physiological conditions. Topics: Adult; Biomarkers; Blood Glucose; C-Peptide; Cross-Over Studies; Diabetes Mellitus, Type 2; Drug Administration Schedule; Female; Gastric Emptying; Glucagon; Glucagon-Like Peptide 1; Humans; Hypoglycemic Agents; Infusions, Intravenous; Insulin; Male; Middle Aged; Missouri; Neurotensin; Postprandial Period; Receptors, Neurotensin; Time Factors; Treatment Outcome | 2014 |
A randomized controlled trial comparing the GLP-1 receptor agonist liraglutide to a sulphonylurea as add on to metformin in patients with established type 2 diabetes during Ramadan: the Treat 4 Ramadan Trial.
To compare a sulphonylurea with the glucagon like peptide-1 (GLP-1) receptor agonist liraglutide in combination with metformin in patients on mono/dual oral therapy with established type 2 diabetes fasting during Ramadan.. Ninety-nine adults intending to fast during Ramadan [50% male, mean age 52 years, body mass index (BMI) 32 kg/m(2)] were randomized from two UK sites. Baseline data were collected ≥14 days prior to Ramadan and at 3 and 12 weeks after Ramadan.. At 12 weeks, more patients in the liraglutide compared with the sulphonylurea group achieved a composite endpoint of haemoglobin A1c (HbA1c) < 7%, no weight gain and no severe hypoglycaemia but this did not reach statistical significance [odds ratio (OR) 4.08, 95% confidence interval (CI) 0.97, 17.22, p = 0.06]. From a baseline of 7.7% there was no change in HbA1c at 12 weeks in the sulphonylurea (+0.02%) compared with a 0.3% reduction in the liraglutide group (adjusted coefficient -0.41, 95% CI -0.83, 0.01, p = 0.05). Significant reductions were also observed in weight and diastolic blood pressure (BP) in the liraglutide compared with the sulphonylurea group. Treatment satisfaction was comparable across the treatment groups. There were no episodes of severe hypoglycaemia in either group, however, self-recorded episodes of blood glucose ≤3.9 mmol/l were significantly lower with liraglutide (incidence rate ratio 0.29, 95% CI 0.19, 0.41, p < 0.0001).. Liraglutide compared with sulphonylurea is well tolerated and maybe an effective therapy in combination with metformin during Ramadan with more patients able to achieve target HbA1c, lose or maintain weight with no severe hypoglycaemia. This was achieved with a high level of treatment satisfaction. Topics: Adult; Diabetes Mellitus, Type 2; Drug Therapy, Combination; Fasting; Female; Glucagon-Like Peptide 1; Glucagon-Like Peptide-1 Receptor; Glycated Hemoglobin; Humans; Hypoglycemia; Hypoglycemic Agents; Islam; Liraglutide; Male; Metformin; Middle Aged; Patient Satisfaction; Receptors, Glucagon; Sulfonylurea Compounds; Treatment Outcome; United Kingdom | 2014 |
A comparison of adding liraglutide versus a single daily dose of insulin aspart to insulin degludec in subjects with type 2 diabetes (BEGIN: VICTOZA ADD-ON).
Two treatment strategies were compared in patients with type 2 diabetes (T2DM) on basal insulin requiring intensification: addition of once-daily (OD) liraglutide (Lira) or OD insulin aspart (IAsp) with largest meal.. Subjects completing 104 weeks (52-week main trial BEGIN ONCE-LONG + 52-week extension) on insulin degludec (IDeg) OD + metformin with HbA1c ≥ 7.0% (≥53 mmol/mol) were randomized to IDeg+Lira [n = 88, mean HbA1c: 7.7% (61 mmol/mol)] or IDeg+IAsp (n = 89, mean HbA1c: 7.7%) for 26 weeks, continuing metformin. Subjects completing 104 weeks with HbA1c <7.0% continued IDeg + metformin in a third, non-randomized arm (n = 236).. IDeg+Lira reduced HbA1c (-0.74%-points) significantly more than IDeg+IAsp (-0.39%-points); estimated treatment difference (ETD) (IDeg+Lira-IDeg+IAsp) -0.32%-points (95% CI -0.53; -0.12); p = 0.0024. More IDeg+Lira (49.4%) than IDeg+IAsp (7.2%) subjects achieved HbA1c <7.0% without confirmed hypoglycaemia [plasma glucose <3.1 mmol/l (<56 mg/dl) or severe hypoglycaemia) and without weight gain; estimated odds ratio (IDeg+Lira/IDeg+IAsp) 13.79 (95% CI 5.24; 36.28); p < 0.0001. IDeg+Lira subjects had significantly less confirmed and nocturnal confirmed hypoglycaemia, and significantly greater weight loss (-2.8 kg) versus IDeg+IAsp (+0.9 kg); ETD (IDeg+Lira-IDeg+IAsp) -3.75 kg (95% CI -4.70; -2.79); p < 0.0001. Other than more gastrointestinal side effects with IDeg+Lira, no safety differences occurred. Durability of IDeg was established in the non-randomized arm, as mean HbA1c remained <7.0% [mean 6.5% (48 mmol/mol) at end-of-trial].. IDeg+Lira improved long-term glycaemic control, with weight loss and less hypoglycaemia versus adding a single daily dose of IAsp in patients with T2DM inadequately controlled with IDeg + metformin. Topics: Blood Glucose; Body Mass Index; Diabetes Mellitus, Type 2; Drug Administration Schedule; Drug Combinations; Drug Therapy, Combination; Female; Glucagon-Like Peptide 1; Humans; Hypoglycemic Agents; Insulin Aspart; Insulin, Long-Acting; Liraglutide; Male; Metformin; Middle Aged; Treatment Outcome; Weight Loss | 2014 |
Effect of linagliptin compared with glimepiride on postprandial glucose metabolism, islet cell function and vascular function parameters in patients with type 2 diabetes mellitus receiving ongoing metformin treatment.
The goal of this study was to investigate the effects of linagliptin compared with glimepiride on alpha and beta cell function and several vascular biomarkers after a standardized test meal.. Thirty-nine patients on metformin alone (age, 64 ± 7 years; duration of type 2 diabetes mellitus, 7.8 ± 4.5years, 27 male, 12 female; HbA1c , 57.2 ± 6.9 mmol/mol; mean ± SD) were randomized to receive linagliptin 5 mg (n = 19) or glimepiride (n = 20) for a study duration of 12 weeks. Glucagon-like peptide 1, blood glucose, insulin, intact proinsulin, glucagon, plasminogen activator inhibitor-1 (PAI-1), cyclic guanosinmonophosphat and asymetric dimethylarginin levels were measured in the fasting state and postprandial at 30-min intervals for a duration of 5 h. The areas under the curve (AUC0-300 min ) were calculated for group comparisons.. HbA1c , fasting and postprandial glucose levels improved in both groups. An increase in postprandial insulin (22595 ± 5984 pmol/L*min), postprandial intact proinsulin (1359 ± 658 pmol/L*min), postprandial glucagon (317 ± 1136 pg/mL*min) and postprandial PAI-1 levels (863 ± 467 ng/mL*min) could be observed during treatment with glimepiride, whereas treatment with linagliptin was associated with a decrease in postprandial insulin (-8007 ± 4204 pmol/L*min), intact proinsulin (-1771 ± 426 pmol/L*min), postprandial glucagon (-1597 ± 1831 pg/mL*min) and PAI-1 levels (-410 ± 276 ng/mL*min).. Despite an improvement in blood glucose control in both groups, linagliptin reduced postprandial insulin, proinsulin, glucagon and PAI-levels. These results indicate an improvement in postprandial alpha and beta cell function, as well as a reduced postprandial vascular risk profile during treatment with linagliptin. Topics: Aged; Biomarkers; Blood Glucose; Cardiovascular Diseases; Diabetes Mellitus, Type 2; Drug Therapy, Combination; Female; Glucagon; Glucagon-Like Peptide 1; Humans; Hypoglycemic Agents; Insulin; Islets of Langerhans; Linagliptin; Male; Metformin; Middle Aged; Plasminogen Activator Inhibitor 1; Postprandial Period; Proinsulin; Purines; Quinazolines; Risk Factors; Sulfonylurea Compounds | 2014 |
Chronic dipeptidyl peptidase-4 inhibition with sitagliptin is associated with sustained protection against ischemic left ventricular dysfunction in a pilot study of patients with type 2 diabetes mellitus and coronary artery disease.
The incretin hormone, glucagon-like peptide-1, promotes myocardial glucose uptake and may improve myocardial tolerance to ischemia. Endogenous glucagon-like peptide-1 (7-36) is augmented by pharmacological inhibition of dipeptidyl peptidase-4. We investigated whether chronic dipeptidyl peptidase-4 inhibition by sitagliptin protected against ischemic left ventricular dysfunction during dobutamine stress in patients with type 2 diabetes mellitus and coronary artery disease.. A total of 19 patients with type 2 diabetes mellitus underwent dobutamine stress echocardiography with tissue Doppler imaging on 2 separate occasions: the first (control) while receiving oral hypoglycemic agents, and the second after the addition of sitagliptin (100 mg once daily) for ≈4 weeks. Sitagliptin increased plasma glucagon-like peptide-1 (7-36) levels and, at peak stress, enhanced both global (ejection fraction, 70.5±7.0 versus 65.7±8.0%; P<0.0001; mitral annular systolic velocity, 11.7±2.6 versus 10.9±2.3 cm/s; P=0.01) and regional left ventricular function, assessed by peak systolic velocity and strain rate in 12 paired, nonapical segments. This was predominantly because of a cardioprotective effect on ischemic segments (strain rate in ischemic segments, -2.27±0.65 versus -1.98±0.58 s(-1); P=0.001), whereas no effect was seen in nonischemic segments (-2.19±0.48 versus -2.18±0.54 s(-1); P=0.87). At 30 minutes recovery, dipeptidyl peptidase-4 inhibition mitigated the postischemic stunning seen in the control scan.. The addition of dipeptidyl peptidase-4 inhibitor therapy with sitagliptin to the treatment regime of patients with type 2 diabetes mellitus and coronary artery disease is associated with a sustained improvement in myocardial performance during dobutamine stress and a reduction in postischemic stunning.. URL: http://www.isrctn.org. Unique identifier ISRCTN61646154. Topics: Aged; Coronary Angiography; Coronary Artery Disease; Diabetes Mellitus, Type 2; Dipeptidyl Peptidase 4; Dipeptidyl-Peptidase IV Inhibitors; Echocardiography, Doppler; Echocardiography, Stress; Electrocardiography; Female; Follow-Up Studies; Glucagon-Like Peptide 1; Heart Ventricles; Humans; Male; Myocardial Ischemia; Pilot Projects; Pyrazines; Sitagliptin Phosphate; Stroke Volume; Treatment Outcome; Triazoles; Ventricular Dysfunction, Left | 2014 |
Lixisenatide resensitizes the insulin-secretory response to intravenous glucose challenge in people with type 2 diabetes--a study in both people with type 2 diabetes and healthy subjects.
Glucagon-like peptide-1 (GLP-1) receptor agonists improve blood glucose control by enhancing glucose-sensitive insulin release, delaying gastric emptying and reducing postprandial glucagon secretion. The studies reported here investigated the insulin response to an intravenous (iv) glucose challenge after injection of lixisenatide (LIXI) 20 µg or placebo.. Two single-centre, double-blind, randomized, placebo-controlled, single-dose, crossover studies were performed in healthy subjects (HS) and people with type 2 diabetes mellitus (T2DM). Participants received subcutaneous LIXI or placebo 2 h before an iv glucose challenge. Study endpoints included first- and second-phase insulin response, insulin concentration (INS), glucagon response and glucose disposal rate (K(glucose)). LIXI exposure was measured over 12 h.. LIXI 20 µg reached maximum concentration after 2 h and resensitized first-phase insulin secretion by 2.8-fold in T2DM to rates comparable with those in HS on placebo, and raised second-phase insulin secretion by 1.6-fold in T2DM. INS rose correspondingly and glucose disposal was accelerated by 1.8-fold in T2DM. First-phase insulin secretion and glucose disposal were also augmented by LIXI in HS, whereas second-phase insulin secretion reduced blood glucose concentrations to below fasting levels and then ceased, accompanied by a rapid, short-lasting rise in glucagon. Otherwise, suppression of glucagon release subsequent to augmentation of insulin release was unaffected in T2DM and in HS.. LIXI resensitized the insulin response to an iv glucose challenge in people with T2DM, thereby accelerating glucose disposal to nearly physiological intensity, and did not impair counter-regulation to low glucose levels by glucagon. Topics: Adult; Blood Glucose; Cross-Over Studies; Diabetes Mellitus, Type 2; Double-Blind Method; Fasting; Female; Gastric Emptying; Glucagon; Glucagon-Like Peptide 1; Glucose Tolerance Test; Healthy Volunteers; Humans; Hypoglycemic Agents; Injections, Intravenous; Insulin; Insulin Secretion; Male; Peptides; Postprandial Period; Treatment Outcome | 2014 |
A randomized dose-finding study demonstrating the efficacy and tolerability of albiglutide in Japanese patients with type 2 diabetes mellitus.
To investigate the optimal dosage/regimen and to evaluate the efficacy and safety of albiglutide in Japanese patients with type 2 diabetes mellitus.. This was a randomized, double-blind, placebo-controlled, multicenter, parallel-group, dose-ranging, superiority study in Japanese patients with type 2 diabetes mellitus. Patients (n = 215) who were treatment naive or washed out of one oral antidiabetic drug were randomized to placebo or albiglutide 15 mg weekly, 30 mg weekly, or 30 mg every other week (biweekly).. NCT01098461.. The primary end point was the change from baseline in HbA1c at week 16, measured using the Japan Diabetes Society standardization scheme and presented here using the National Glycohemoglobin Standardization Program equivalents. Other measures of efficacy as well as safety and population pharmacokinetics and pharmacokinetics/pharmacodynamics of albiglutide were assessed.. Baseline HbA1c was 8.53%. There was a statistically significant difference between each albiglutide treatment group and placebo for change from baseline in HbA1c at week 16, with treatment effects of -0.89% for 15 mg weekly, -1.55% for 30 mg weekly, and -1.10% for 30 mg biweekly (P < 0.0001 for all groups vs placebo). By week 16, 63.0% and 33.3% of patients in the 30 mg weekly albiglutide group compared with 6.0% and 0% of patients in the placebo group achieved HbA1c <7.4% and <6.9%, respectively. No serious adverse events were related to study therapy; no deaths occurred. Nasopharyngitis was the most frequently reported adverse event in all treatment groups (n = 43 [20.3%]).. Albiglutide exhibited therapeutic hypoglycemic effects with good tolerability among Japanese patients with type 2 diabetes mellitus; the 30 mg weekly dose was the most efficacious in this study. The 16 week duration of the study prevents generalizing these conclusions to longer treatment periods. Topics: Administration, Oral; Adult; Aged; Diabetes Mellitus, Type 2; Female; Glucagon-Like Peptide 1; Glycated Hemoglobin; Humans; Hypoglycemic Agents; Japan; Male; Middle Aged; Young Adult | 2014 |
Liraglutide decreases carotid intima-media thickness in patients with type 2 diabetes: 8-month prospective pilot study.
Liraglutide, a long-acting glucagon-like peptide-1 (GLP-1) analog, has several non- glycemic properties, but its effect on carotid intima-media thickness (IMT), a recognized marker of subclinical atherosclerosis, is still unknown.. A prospective study of 8 months duration in 64 patients with type-2 diabetes and no prior history of coronary artery disease evaluated whether adding liraglutide to metformin affects carotid IMT, measured by color doppler ultrasound.. After 8 months, fasting glucose decreased by 2.1 mmol/l and HbA1c by 1.9% (p < 0.01 for all). Liraglutide reduced total-cholesterol and triglycerides by 10%, and LDL-cholesterol by 19%, whereas HDL-cholesterol increased by 18% (p < 0.01 for all lipid changes). Carotid IMT decreased from 1.19 ± 0.47 to 0.94 ± 0.21 mm (p < 0.01). Yet, changes in carotid IMT did not correlate with changes in any other variable studied.. Liraglutide decreases carotid IMT after 8 months treatment independently of its effect on plasma glucose and lipids concentrations.. ClinicalTrials.gov: NCT01715428. Topics: Aged; Carotid Intima-Media Thickness; Diabetes Mellitus, Type 2; Female; Glucagon-Like Peptide 1; Humans; Hypoglycemic Agents; Liraglutide; Male; Middle Aged; Pilot Projects; Prospective Studies | 2014 |
The effect of addition of liraglutide to high-dose intensive insulin therapy: a randomized prospective trial.
Patients with type 2 diabetes and insulin resistance may require high insulin doses to control hyperglycaemia. The addition of glucagon-like peptide-1 receptor agonists (GLP-1 RAs) to basal insulin therapy has been shown to reduce insulin requirement while reducing insulin-associated weight gain [1,2]. The effect of GLP-1 RA therapy added to intensive (basal/bolus) insulin therapy has not been studied in a prospective trial. This trial evaluated the effect of the addition of liraglutide to high-dose intensive insulin therapy compared with standard insulin up-titration in obese insulin-resistant patients with type 2 diabetes requiring high-dose insulin therapy.. Thirty-seven subjects with type 2 diabetes requiring >100 units of insulin daily administered either by continuous subcutaneous insulin infusion (CSII) or by multiple daily injections (MDIs) with or without metformin were randomized to receive either liraglutide plus insulin (LIRA) or intensive insulin only (controls). Liraglutide was initiated at 0.6 mg subcutaneously (sq) per day and increased to either 1.2 or 1.8 mg daily in combination with intensive insulin therapy. Controls received intensive insulin up-titration only.. At 6 months, subjects receiving liraglutide plus insulin experienced statistically significant reductions in HbA1c, weight, insulin dose and glycaemic variability (GV) by continuous glucose monitor (CGM) compared with the control group receiving insulin only.. Adding liraglutide to intensive high-dose (basal/bolus) insulin therapy results in greater improvement in glycaemic control than insulin therapy alone, with additional benefits of weight loss and reduced GV. Topics: Blood Glucose; Body Mass Index; Body Weight; Diabetes Mellitus, Type 2; Drug Administration Schedule; Drug Therapy, Combination; Female; Glucagon-Like Peptide 1; Glycated Hemoglobin; Humans; Hyperglycemia; Hypoglycemic Agents; Insulin; Liraglutide; Male; Middle Aged; Obesity; Prospective Studies; Treatment Outcome | 2014 |
Postprandial effects of test meals including concentrated arabinoxylan and whole grain rye in subjects with the metabolic syndrome: a randomised study.
Prospective studies have shown an inverse relationship between whole grain consumption and the risk of type 2 diabetes, where short chain fatty acids (SCFA) may be involved. Our objective was to determine the effect of isolated arabinoxylan alone or in combination with whole grain rye kernels on postprandial glucose, insulin, free fatty acids (FFA), gut hormones, SCFA and appetite in subjects with the metabolic syndrome (MetS).. Fifteen subjects with MetS participated in this acute, randomised, cross-over study. The test meals each providing 50 g of digestible carbohydrate were as follows: semolina porridge added concentrated arabinoxylan (AX), rye kernels (RK) or concentrated arabinoxylan combined with rye kernels (AXRK) and semolina porridge as control (SE). A standard lunch was served 4 h after the test meals. Blood samples were drawn during a 6-h period, and appetite scores and breath hydrogen were assessed every 30 min.. The AXRK meal reduced the acute glucose (P=0.005) and insulin responses (P<0.001) and the feeling of hunger (P=0.005; 0-360 min) compared with the control meal. The AX and AXRK meals increased butyrate and acetate concentrations after 6 h. No significant differences were found for the second meal responses of glucose, insulin, FFA, glucagon-like peptide-1 or ghrelin.. Our results indicate a stimulatory effect of arabinoxylan on butyrate and acetate production, however, with no detectable effect on the second meal glucose response. It remains to be tested in a long-term study if a beneficial effect on the glucose response of the isolated arabinoxylan will be related to the SCFA production. Topics: Aged; Appetite; Blood Glucose; Breath Tests; Cross-Over Studies; Diabetes Mellitus, Type 2; Fatty Acids, Nonesterified; Fatty Acids, Volatile; Female; Gastrointestinal Hormones; Ghrelin; Glucagon-Like Peptide 1; Humans; Hunger; Insulin; Male; Meals; Metabolic Syndrome; Middle Aged; Postprandial Period; Secale; Triticum; Xylans | 2014 |
A whole-grain cereal-based diet lowers postprandial plasma insulin and triglyceride levels in individuals with metabolic syndrome.
Until recently, very few intervention studies have investigated the effects of whole-grain cereals on postprandial glucose, insulin and lipid metabolism, and the existing studies have provided mixed results. The objective of this study was to evaluate the effects of a 12-week intervention with either a whole-grain-based or a refined cereal-based diet on postprandial glucose, insulin and lipid metabolism in individuals with metabolic syndrome.. Sixty-one men and women age range 40-65 years, with the metabolic syndrome were recruited to participate in this study using a parallel group design. After a 4-week run-in period, participants were randomly assigned to a 12-week diet based on whole-grain products (whole-grain group) or refined cereal products (control group). Blood samples were taken at the beginning and end of the intervention, both fasting and 3 h after a lunch, to measure biochemical parameters. Generalized linear model (GLM) was used for between-group comparisons. Overall, 26 participants in the control group and 28 in the whole-grain group completed the dietary intervention. Drop-outs (five in the control and two in the whole-grain group) did not affect randomization. After 12 weeks, postprandial insulin and triglyceride responses (evaluated as average change 2 and 3 h after the meal, respectively) decreased by 29% and 43%, respectively, in the whole-grain group compared to the run-in period. Postprandial insulin and triglyceride responses were significantly lower at the end of the intervention in the whole-grain group compared to the control group (p = 0.04 and p = 0.05; respectively) whereas there was no change in postprandial response of glucose and other parameters evaluated.. A twelve week whole-grain cereal-based diet, compared to refined cereals, reduced postprandial insulin and triglycerides responses. This finding may have implications for type 2 diabetes risk and cardiovascular disease. Topics: Adult; Aged; Apolipoproteins A; Apolipoproteins B; Blood Glucose; Cardiovascular Diseases; Cholesterol, HDL; Cholesterol, LDL; Diabetes Mellitus, Type 2; Diet; Edible Grain; Fatty Acids, Nonesterified; Female; Glucagon-Like Peptide 1; Glycemic Index; Humans; Insulin; Linear Models; Lipid Metabolism; Male; Metabolic Syndrome; Middle Aged; Nutrition Assessment; Patient Compliance; Postprandial Period; Triglycerides | 2014 |
Effects of green tea extract on insulin resistance and glucagon-like peptide 1 in patients with type 2 diabetes and lipid abnormalities: a randomized, double-blinded, and placebo-controlled trial.
The aim of this study is to investigate the effect of green tea extract on patients with type 2 diabetes mellitus and lipid abnormalities on glycemic and lipid profiles, and hormone peptides by a double-blinded, randomized and placebo-controlled clinical trial. This trial enrolled 92 subjects with type 2 diabetes mellitus and lipid abnormalities randomized into 2 arms, each arm comprising 46 participants. Of the participants, 39 in therapeutic arm took 500 mg green tea extract, three times a day, while 38 in control arm took cellulose with the same dose and frequency to complete the 16-week study. Anthropometrics measurements, glycemic and lipid profiles, safety parameters, and obesity-related hormone peptides were analyzed at screening and after 16-week course. Within-group comparisons showed that green tea extract caused a significant decrease in triglyceride and homeostasis model assessment of insulin resistance index after 16 weeks. Green tea extract also increased significantly high density lipoprotein cholesterol. The HOMA-IR index decreased from 5.4±3.9 to 3.5±2.0 in therapeutic arm only. Adiponectin, apolipoprotein A1, and apolipoprotein B100 increased significantly in both arms, but only glucagon-like peptide 1 increased in the therapeutic arm. However, only decreasing trend in triglyceride was found in between-group comparison. Our study suggested that green tea extract significantly improved insulin resistance and increased glucagon-like peptide 1 only in within-group comparison. The potential effects of green tea extract on insulin resistance and glucagon-like peptide 1 warrant further investigation.. ClinicalTrials.gov NCT01360567. Topics: Demography; Diabetes Mellitus, Type 2; Double-Blind Method; Female; Glucagon-Like Peptide 1; Humans; Insulin Resistance; Lipids; Male; Middle Aged; Placebos; Plant Extracts | 2014 |
Effects of sitagliptin on glycemia, incretin hormones, and antropyloroduodenal motility in response to intraduodenal glucose infusion in healthy lean and obese humans and patients with type 2 diabetes treated with or without metformin.
The impact of variations in gastric emptying, which influence the magnitude of glucose-dependent insulinotropic polypeptide (GIP) and glucagon-like peptide 1 (GLP-1) secretion, on glucose lowering by dipeptidyl peptidase-4 (DPP-4) inhibitors is unclear. We evaluated responses to intraduodenal glucose infusion (60 g over 120 min [i.e., 2 kcal/min], a rate that predominantly stimulates GIP but not GLP-1) after sitagliptin versus control in 12 healthy lean, 12 obese, and 12 type 2 diabetic subjects taking metformin 850 mg b.i.d. versus placebo. As expected, sitagliptin augmented plasma-intact GIP substantially and intact GLP-1 modestly. Sitagliptin attenuated glycemic excursions in healthy lean and obese but not type 2 diabetic subjects, without affecting glucagon or energy intake. In contrast, metformin reduced fasting and glucose-stimulated glycemia, suppressed energy intake, and augmented total and intact GLP-1, total GIP, and glucagon in type 2 diabetic subjects, with no additional glucose lowering when combined with sitagliptin. These observations indicate that in type 2 diabetes, 1) the capacity of endogenous GIP to lower blood glucose is impaired; 2) the effect of DPP-4 inhibition on glycemia is likely to depend on adequate endogenous GLP-1 release, requiring gastric emptying >2 kcal/min; and 3) the action of metformin to lower blood glucose is not predominantly by way of the incretin axis. Topics: Adult; Blood Glucose; Diabetes Mellitus, Type 2; Double-Blind Method; Drug Therapy, Combination; Energy Intake; Gastric Inhibitory Polypeptide; Gastrointestinal Motility; Glucagon-Like Peptide 1; Glucose; Humans; Hypoglycemic Agents; Incretins; Male; Metformin; Obesity; Pyrazines; Sitagliptin Phosphate; Triazoles | 2014 |
Exploratory trial of intranasal administration of glucagon-like peptide-1 in Japanese patients with type 2 diabetes.
This study aimed to assess the efficacy and safety of our newly developed nasal glucagon-like peptide-1 (GLP-1) compound and injector.. Twenty-six patients with type 2 diabetes were enrolled in this double-blind placebo-controlled study. The nasal compound containing 1.2 mg of human GLP-1 (7-36) amide or placebo was administered immediately before every meal for 2 weeks.. The plasma peak concentration of active GLP-1 was 47.2 pmol/L, and its Tmax was 8.1 min. The early phase of insulin and glucagon secretion were recovered and suppressed, respectively, in the GLP-1 group. Glycoalbumin levels became significantly lower and 1,5-anhydroglucitol levels significantly higher after GLP-1 administration. No marked adverse events were observed after using nasal GLP-1.. The newly developed nasal GLP-1 compound may be a potential treatment for type 2 diabetes. The long-term application of the drug should be evaluated in future trials. Topics: Administration, Intranasal; Aged; Asian People; Diabetes Mellitus, Type 2; Double-Blind Method; Female; Glucagon; Glucagon-Like Peptide 1; Humans; Insulin; Insulin Secretion; Male; Middle Aged; Prospective Studies | 2014 |
Simultaneous GLP-1 and insulin administration acutely enhances their vasodilatory, antiinflammatory, and antioxidant action in type 2 diabetes.
To test the hypothesis that the simultaneous administration of GLP-1 and insulin may increase their vasodilatory, antiinflammatory, and antioxidant action in type 2 diabetes.. In two groups of persons with type 2 diabetes, two sets of experiments were performed. The first group had two normoglycemic-normoinsulinemic clamps with or without GLP-1 and two normoglycemic-hyperinsulinemic clamps with or without GLP-1. The second group had two hyperglycemic-normoinsulinemic clamps and two hyperglycemic-hyperinsulinemic clamps with or without GLP-1.. During the normoglycemic-hyperinsulinemic clamp, flow-mediated dilatation (FMD) increased, while soluble intercellular adhesion molecule (sICAM-1), plasma 8-iso-prostaglandin F2α (8-iso-PGF2α), nitrotyrosine, and interleukin (IL)-6 decreased compared with normoglycemic-normoinsulinemic clamp. Similar results were obtained with the infusion of GLP-1 during the normoglycemic-normoinsulinemic clamp. The combination of hyperinsulinemia and GLP-1 in normoglycemia was accompanied by a further FMD increase and sICAM-1, 8-iso-PGF2α, nitrotyrosine, and IL-6 decrease. During the hyperglycemic-normoinsulinemic clamp, FMD significantly decreased, while sICAM-1, 8-iso-PGF2α, nitrotyrosine, and IL-6 significantly increased. When hyperglycemia was accompanied by hyperinsulinemia or by the simultaneous infusion of GLP-1, these phenomena were attenuated. The simultaneous presence of hyperinsulinemia and GLP-1 had an increased beneficial effect.. Our results show that the combination of insulin and GLP-1 is more effective than insulin or GLP-1 alone in improving endothelial dysfunction, inflammation, and oxidative stress in type 2 diabetes. Topics: Anti-Inflammatory Agents; Antioxidants; Diabetes Mellitus, Type 2; Dinoprost; Female; Glucagon-Like Peptide 1; Humans; Hyperglycemia; Hyperinsulinism; Hypoglycemic Agents; Insulin; Interleukin-6; Male; Middle Aged; Oxidative Stress; Vasodilator Agents | 2014 |
Gut hormone pharmacology of a novel GPR119 agonist (GSK1292263), metformin, and sitagliptin in type 2 diabetes mellitus: results from two randomized studies.
GPR119 receptor agonists improve glucose metabolism and alter gut hormone profiles in animal models and healthy subjects. We therefore investigated the pharmacology of GSK1292263 (GSK263), a selective GPR119 agonist, in two randomized, placebo-controlled studies that enrolled subjects with type 2 diabetes. Study 1 had drug-naive subjects or subjects who had stopped their diabetic medications, and Study 2 had subjects taking metformin. GSK263 was administered as single (25-800 mg; n = 45) or multiple doses (100-600 mg/day for 14 days; n = 96). Placebo and sitagliptin 100 mg/day were administered as comparators. In Study 1, sitagliptin was co-administered with GSK263 or placebo on Day 14 of dosing. Oral glucose and meal challenges were used to assess the effects on plasma glucose, insulin, C-peptide, glucagon, peptide tyrosine-tyrosine (PYY), glucagon-like peptide-1 (GLP-1) and glucose-dependent insulinotropic peptide (GIP). After 13 days of dosing, GSK263 significantly increased plasma total PYY levels by ∼ five-fold compared with placebo, reaching peak concentrations of ∼ 50 pM after each of the three standardized meals with the 300 mg BID dose. Co-dosing of GSK263 and metformin augmented peak concentrations to ∼ 100 pM at lunchtime. GSK263 had no effect on active or total GLP-1 or GIP, but co-dosing with metformin increased post-prandial total GLP-1, with little effect on active GLP-1. Sitagliptin increased active GLP-1, but caused a profound suppression of total PYY, GLP-1, and GIP when dosed alone or with GSK263. This suppression of peptides was reduced when sitagliptin was co-dosed with metformin. GSK263 had no significant effect on circulating glucose, insulin, C-peptide or glucagon levels. We conclude that GSK263 did not improve glucose control in type 2 diabetics, but it had profound effects on circulating PYY. The gut hormone effects of this GPR119 agonist were modulated when co-dosed with metformin and sitagliptin. Metformin may modulate negative feedback loops controlling the secretion of enteroendocrine peptides.. Clinicaltrials.gov NCT01119846 Clinicaltrials.gov NCT01128621. Topics: Blood Glucose; C-Peptide; Cross-Over Studies; Diabetes Mellitus, Type 2; Double-Blind Method; Drug Therapy, Combination; Female; Gastrointestinal Hormones; Glucagon; Glucagon-Like Peptide 1; Humans; Hypoglycemic Agents; Insulin; Male; Mesylates; Metformin; Middle Aged; Oxadiazoles; Peptide YY; Prognosis; Pyrazines; Receptors, G-Protein-Coupled; Sitagliptin Phosphate; Triazoles | 2014 |
Once-weekly albiglutide versus once-daily liraglutide in patients with type 2 diabetes inadequately controlled on oral drugs (HARMONY 7): a randomised, open-label, multicentre, non-inferiority phase 3 study.
As new members of a drug class are developed, head-to-head trials are an important strategy to guide personalised treatment decisions. We assessed two glucagon-like peptide-1 receptor agonists, once-weekly albiglutide and once-daily liraglutide, in patients with type 2 diabetes inadequately controlled on oral antidiabetic drugs.. We undertook this 32-week, open-label, phase 3 non-inferiority study at 162 sites in eight countries: USA (121 sites), Australia (9 sites), Peru (7 sites), Philippines (7 sites), South Korea (5 sites), UK (5 sites), Israel (4 sites), and Spain (4 sites). 841 adult participants (aged ≥18 years) with inadequately controlled type 2 diabetes and a BMI between 20 and 45 kg/m(2) were enrolled and randomised in a 1:1 ratio to receive albiglutide 30 mg once weekly titrated to 50 mg at week 6, or liraglutide 0·6 mg once daily titrated to 1·2 mg at week 1 and 1·8 mg at week 2. The randomisation schedule was generated by an independent randomisation team by the permuted block method with a fixed block size of 16. Participants and investigators were unmasked to treatment. The primary endpoint was change from baseline in HbA1c for albiglutide versus liraglutide, with a 95% CI non-inferiority upper margin of 0·3%. The primary analysis was by modified intention to treat. The study is registered with ClinicalTrials.gov, number NCT01128894.. 422 patients were randomly allocated to the albigultide group and 419 to the liraglutide group; 404 patients in the abliglutide group and 408 in the liraglutide group received the study drugs. The primary endpoint analysis was done on the modified intention-to-treat population, which included 402 participants in the albiglutide group and 403 in the liraglutide group. Model-adjusted change in HbA1c from baseline to week 32 was -0·78% (95% CI -0·87 to -0·69) in the albigludite group and -0·99% (-1·08 to -0·90) in the liraglutide group; treatment difference was 0·21% (0·08-0·34; non-inferiority p value=0·0846). Injection-site reactions occurred in more patients given albiglutide than in those given liraglutide (12·9% vs 5·4%; treatment difference 7·5% [95% CI 3·6-11·4]; p=0·0002), whereas the opposite was the case for gastrointestinal events, which occurred in 49·0% of patients in the liraglutide group versus 35·9% in the albiglutide group (treatment difference -13·1% [95% CI -19·9 to -6·4]; p=0·00013).. Patients who received once-daily liraglutide had greater reductions in HbA1c than did those who received once-weekly albiglutide. Participants in the albiglutide group had more injection-site reactions and fewer gastrointestinal events than did those in the liraglutide group.. GlaxoSmithKline. Topics: Adult; Aged; Blood Glucose; Diabetes Mellitus, Type 2; Female; Glucagon-Like Peptide 1; Glycated Hemoglobin; Humans; Hypoglycemic Agents; Liraglutide; Male; Middle Aged; Treatment Outcome | 2014 |
Exenatide once weekly versus insulin glargine for type 2 diabetes (DURATION-3): 3-year results of an open-label randomised trial.
When patients with type 2 diabetes start their first injectable therapy, clinicians can choose between glucagon-like peptide-1 (GLP-1) receptor agonists and basal insulins. In DURATION-3, exenatide once weekly was compared with insulin glargine (henceforth, glargine) as first injectable therapy. Here, we report the results of the final 3-year follow-up.. DURATION-3 was an open-label randomised trial done between May 13, 2008, and Jan 30, 2012. Patients with type 2 diabetes aged 18 years or older were enrolled at 72 sites worldwide. They were eligible when they had suboptimum glycaemic control (HbA1c 7.1-11.0% [54-97 mmol/mol]) despite maximum tolerated doses of metformin alone or with a sulfonylurea for at least 3 months, a stable bodyweight for at least 3 months, and a BMI of 25-45 kg/m(2) (23-45 kg/m(2) in South Korea and Taiwan). Patients were randomly assigned (1:1) by computer-generated random sequence with an interactive voice-response system (block size four, stratified by country and concomitant therapy) to once-weekly exenatide (2 mg subcutaneous injection) or once-daily glargine (titrated to target) to be given in addition to their existing oral glucose-lowering regimens. The primary efficacy measure at 3 years was change in HbA1c from baseline in patients given at least one dose of the assigned drug (ie, analyses by modified intention to treat). Patients, investigators, and data analysts were not masked to treatment assignment. This trial is registered with ClinicalTrials.gov, number NCT00641056.. 456 patients underwent randomisation and received at least one dose of the assigned drug (233 given exenatide, 223 glargine). At 3 years, least-squares mean HbA1c change was -1.01% (SE 0.07) in the exenatide group versus -0.81% (0.07) in the glargine group (least-squares mean difference -0.20%, SE 0.10, 95% CI -0.39 to -0.02; p=0.03). Transient gastrointestinal adverse events characteristic of GLP-1 receptor agonists were more frequent with exenatide than glargine (nausea: 36 [15%] of 233 patients vs five [2%] of 223; vomiting: 15 [6%] vs six [3%]; diarrhoea: 32 [14%] vs 15 [7%]), although frequency of these events did decrease after week 26 in the exenatide group. The proportion of patients who reported serious adverse events in the exenatide group (36 patients [15%]) was the same as that in the glargine group (33 [15%]). The exposure-adjusted rate of overall hypoglycaemia was three times higher in patients given glargine (0.9 events per patient per year) than in those given exenatide (0.3 events per patient per year).. Efficacy of once-weekly exenatide is sustained for 3 years. GLP-1 receptor agonists could be a viable long-term injectable treatment option in patients with type 2 diabetes who have not yet started taking insulin.. Amylin Pharmaceuticals and Eli Lilly. Topics: Blood Glucose; Body Mass Index; Diabetes Mellitus, Type 2; Drug Administration Schedule; Exenatide; Female; Follow-Up Studies; Glucagon-Like Peptide 1; Glycated Hemoglobin; Humans; Hypoglycemic Agents; Injections, Subcutaneous; Insulin Glargine; Insulin, Long-Acting; Male; Middle Aged; Peptides; Republic of Korea; Taiwan; Treatment Outcome; Venoms | 2014 |
Efficacy and safety of dulaglutide versus sitagliptin after 52 weeks in type 2 diabetes in a randomized controlled trial (AWARD-5).
To compare the efficacy and safety of two doses of once-weekly dulaglutide, a glucagon-like peptide 1 receptor agonist, to sitagliptin in uncontrolled, metformin-treated patients with type 2 diabetes. The primary objective was to compare (for noninferiority and then superiority) dulaglutide 1.5 mg versus sitagliptin in change from baseline in glycosylated hemoglobin A1c (HbA1c) at 52 weeks.. This multicenter, adaptive, double-blind, parallel-arm study randomized patients (N = 1,098; mean baseline age 54 years; HbA1c 8.1% [65 mmol/mol]; weight 86.4 kg; diabetes duration 7 years) to dulaglutide 1.5 mg, dulaglutide 0.75 mg, sitagliptin 100 mg, or placebo (placebo-controlled period up to 26 weeks). The treatment period lasted 104 weeks, with 52-week primary end point data presented.. The mean HbA1c changes to 52 weeks were (least squares mean ± SE): -1.10 ± 0.06% (-12.0 ± 0.7 mmol/mol), -0.87 ± 0.06% (9.5 ± 0.7 mmol/mol), and -0.39 ± 0.06% (4.3 ± 0.7 mmol/mol) for dulaglutide 1.5 mg, dulaglutide 0.75 mg, and sitagliptin, respectively. Both dulaglutide doses were superior to sitagliptin (P < 0.001, both comparisons). No events of severe hypoglycemia were reported. Mean weight changes to 52 weeks were greater with dulaglutide 1.5 mg (-3.03 ± 0.22 kg) and dulaglutide 0.75 mg (-2.60 ± 0.23 kg) compared with sitagliptin (-1.53 ± 0.22 kg) (P < 0.001, both comparisons). The most common gastrointestinal treatment-emergent adverse events in dulaglutide 1.5- and 0.75-mg arms were nausea, diarrhea, and vomiting.. Both dulaglutide doses demonstrated superior glycemic control versus sitagliptin at 52 weeks with an acceptable tolerability and safety profile. Topics: Aged; Blood Glucose; Diabetes Mellitus, Type 2; Dose-Response Relationship, Drug; Double-Blind Method; Drug Therapy, Combination; Female; Glucagon-Like Peptide 1; Glucagon-Like Peptides; Glycated Hemoglobin; Humans; Hypoglycemic Agents; Immunoglobulin Fc Fragments; Male; Metformin; Middle Aged; Pyrazines; Recombinant Fusion Proteins; Sitagliptin Phosphate; Treatment Outcome; Triazoles | 2014 |
Efficacy and safety comparison of add-on therapy with liraglutide, saxagliptin and vildagliptin, all in combination with current conventional oral hypoglycemic agents therapy in poorly controlled Chinese type 2 diabetes.
To compare the efficacy and safety of adding liraglutide, saxagliptin and vildagliptin to current therapy in Chinese type 2 diabetes subjects with poor glycemic control.A 24-week, randomized, open-label, parallel clinical trial was performed. A total 178 patients completed the trial who had been randomly assigned to add-on once daily liraglutide (1.2 mg/day injected subcutaneously), to saxagliptin (5 mg once daily) or to vildagliptin (50 mg twice daily). Glycosylated hemoglobin (HbA1c) values, fasting and postprandial blood glucose (FBG and P2BG), body weight, body mass index (BMI), episodes of hypoglycemia and adverse events were evaluated.Over the 24-week treatment period, greater lowering of mean of HbA1c was achieved with 1.2 mg liraglutide (-1.50%, 95% CI [-1.67, -1.34]) than with saxagliptin (-1.23%, 95% CI [-1.36, -1.11]) and vildagliptin (-1.25%, 95% CI [-1.37, -1.13]). There was no significant between-group difference of percentages of subjects who reached a target HbA1c<7.0%, but significantly more subjects with liraglutide achieved HbA1c≤6.5% compared with saxagliptin and vildagliptin. The mean reduction of FBG value from baseline was 2.23 mmol/L with liraglutide, much greater than 1.83 mmol/L with saxagliptin (p=0.013), but similar to 2.03 mmol/L with -vildaglitpin group. As to the P2BG value, greater reductions was found with liraglutide (-4.80 mmol/L) than -3.56 mmol/L with saxagliptin (p=0.000) and -3.57 mmol/L with vildagliptin (p=0.000). Moreover, greater mean reductions of body weight and BMI with liraglutide (-6.0 kg and -2.1 kg/m(2)) were achieved than with saxagliptin and vildagliptin (both p<0.001), whereas no significant difference was found between saxagliptin and vildagliptin group. The incidence of hypoglycemia was recorded low and similar in each treatment group. Nausea was more common with liraglutide (27%) than with saxagliptin (3.2%) and vildagliptin (5.2%), but no significant between-group difference was reported in other AEs.Adding liraglutide demonstrated superiority to saxagliptin and vildagliptin for reductions of HbA1c and weight loss in Chinese subjects with T2DM who had inadequate glycemic control with conventional oral hypoglycemic agents. These findings support the add-on of liraglutide could offer notable advantages over DPP-4 inhibitors in both efficacy and safety. Topics: Adamantane; Adult; Asian People; Blood Glucose; Body Weight; China; Diabetes Mellitus, Type 2; Dipeptides; Drug Therapy, Combination; Female; Glucagon-Like Peptide 1; Humans; Hypoglycemic Agents; Insulin; Liraglutide; Male; Metformin; Middle Aged; Nitriles; Pyrrolidines; Treatment Outcome; Vildagliptin | 2014 |
Impaired incretin secretion and pancreatic dysfunction with older age and diabetes.
To estimate the impact of aging and diabetes on insulin sensitivity, beta-cell function, adipocytokines, and incretin production.. Hyperglycemic clamps, arginine tests and meal tolerance tests were performed in 50 non-obese subjects to measure insulin sensitivity (IS) and insulin secretion as well as plasma levels of glucagon, GLP-1 and GIP. Patients with diabetes and healthy control subjects were divided into the following groups: middle-aged type 2 diabetes (MA-DM), aged Type 2 diabetes (A-DM) and middle-aged or aged subjects with normal glucose tolerance (MA-NGT or A-NGT).. IS, as determined by the homeostasis model assessment, glucose infusion rate, and oral glucose insulin sensitivity, was reduced in the aged and DM groups compared with MA-NGT, but it was similar in the MA-DM and A-DM groups. Insulinogenic index, first and second phase insulin secretion and the disposition indices, but not insulin response to arginine, were reduced in the aged and DM groups. Postprandial glucagon production was higher in MA-DM compared to MA-NGT. Whereas the GLP-1 production was reduced in A-DM, no differences between groups were observed in GIP production.. In non-obese subjects, diabetes and aging impair insulin sensitivity. Insulin production is reduced by aging, and diabetes exacerbates this condition. Aging associated defects superimposed diabetic physiopathology, particularly regarding GLP-1 production. On the other hand, the glucose-independent secretion of insulin was preserved. Knowledge of the complex relationship between aging and diabetes could support the development of physiopathological and pharmacological based therapies. Topics: Adiponectin; Adipose Tissue; Adult; Aged; Aging; Cross-Sectional Studies; Diabetes Mellitus, Type 2; Down-Regulation; Gastric Inhibitory Polypeptide; Glucagon; Glucagon-Like Peptide 1; Humans; Incretins; Insulin; Insulin Resistance; Insulin Secretion; Male; Middle Aged; Pancreas; Postprandial Period; Up-Regulation | 2014 |
Advancing basal insulin replacement in type 2 diabetes inadequately controlled with insulin glargine plus oral agents: a comparison of adding albiglutide, a weekly GLP-1 receptor agonist, versus thrice-daily prandial insulin lispro.
GLP-1 receptor agonists may provide an alternative to prandial insulin for advancing basal insulin therapy. Harmony 6 was a randomized, open-label, active-controlled trial testing once-weekly albiglutide vs. thrice-daily prandial insulin lispro as an add-on to titrated once-daily insulin glargine.. Patients taking basal insulin (with or without oral agents) with HbA1c 7-10.5% (53-91 mmol/mol) entered a glargine standardization period, followed by randomization to albiglutide, 30 mg weekly (n = 282), subsequently uptitrated to 50 mg, if necessary, or thrice-daily prandial lispro (n = 281) while continuing metformin and/or pioglitazone. Glargine was titrated to fasting plasma glucose of <5.6 mmol/L, and lispro was adjusted based on glucose monitoring. The primary end point was the difference in the HbA1c change from baseline at week 26.. At week 26, HbA1c decreased from baseline by -0.82 ± SE 0.06% (9.0 mmol/mol) with albiglutide and -0.66 ± 0.06% (7.2 mmol/mol) with lispro; treatment difference, -0.16% (95% CI -0.32 to 0.00; 1.8 mmol/mol; P < 0.0001), meeting the noninferiority end point (margin, 0.4%). Weight decreased with albiglutide but increased with lispro (-0.73 ± 0.19 kg vs. +0.81 ± 0.19 kg). The mean glargine dose increased from 47 to 53 IU (albiglutide) and from 44 to 51 IU (lispro). Adverse events for albiglutide versus lispro included severe hypoglycemia (0 vs. 2 events), documented symptomatic hypoglycemia (15.8% vs. 29.9%), nausea (11.2% vs. 1.4%), vomiting (6.7% vs. 1.4%), and injection site reactions (9.5% vs. 5.3%).. Weekly albiglutide is a simpler therapeutic option than thrice-daily lispro for advancing basal insulin glargine therapy, resulting in comparable HbA1c reduction with weight loss and lower hypoglycemia risk. Topics: Administration, Oral; Adult; Aged; Blood Glucose; Diabetes Mellitus, Type 2; Drug Administration Schedule; Drug Substitution; Drug Therapy, Combination; Female; Glucagon-Like Peptide 1; Glucagon-Like Peptide-1 Receptor; Glycated Hemoglobin; Humans; Hypoglycemic Agents; Insulin; Insulin Glargine; Insulin Lispro; Insulin, Long-Acting; Male; Meals; Metformin; Middle Aged; Pioglitazone; Receptors, Glucagon; Thiazolidinediones; Treatment Outcome | 2014 |
HARMONY 3: 104-week randomized, double-blind, placebo- and active-controlled trial assessing the efficacy and safety of albiglutide compared with placebo, sitagliptin, and glimepiride in patients with type 2 diabetes taking metformin.
To compare the efficacy and safety of weekly albiglutide with daily sitagliptin, daily glimepiride, and placebo.. Patients with type 2 diabetes receiving metformin were randomized to albiglutide (30 mg), sitagliptin (100 mg), glimepiride (2 mg), or placebo. Blinded dose titration for albiglutide (to 50 mg) and glimepiride (to 4 mg) was based on predefined hyperglycemia criteria. The primary end point was change in HbA1c from baseline at week 104. Secondary end points included fasting plasma glucose (FPG), weight, and time to hyperglycemic rescue.. Baseline characteristics were similar among the albiglutide (n = 302), glimepiride (n = 307), sitagliptin (n = 302), and placebo (n = 101) groups. Baseline HbA1c was 8.1% (65.0 mmol/mol); mean age was 54.5 years. The mean doses for albiglutide and glimepiride at week 104 were 40.5 and 3.1 mg, respectively. At week 104, albiglutide significantly reduced HbA1c compared with placebo (-0.9% [-9.8 mmol/mol]; P < 0.0001), sitagliptin (-0.4% [-4.4 mmol/mol]; P = 0.0001), and glimepiride (-0.3% [-3.3 mmol/mol]; P = 0.0033). Outcomes for FPG and HbA1c were similar. Weight change from baseline for each were as follows: albiglutide -1.21 kg (95% CI -1.68 to -0.74), placebo -1.00 kg (95% CI -1.81 to -0.20), sitagliptin -0.86 kg (95% CI -1.32 to -0.39), glimepiride 1.17 kg (95% CI 0.70-1.63). The difference between albiglutide and glimepiride was statistically significant (P < 0.0001). Hyperglycemic rescue rate at week 104 was 25.8% for albiglutide compared with 59.2% (P < 0.0001), 36.4% (P = 0.0118), and 32.7% (P = 0.1504) for placebo, sitagliptin, and glimepiride, respectively. Rates of serious adverse events in the albiglutide group were similar to comparison groups. Diarrhea (albiglutide 12.9%, other groups 8.6-10.9%) and nausea (albiglutide 10.3%, other groups 6.2-10.9%) were generally the most frequently reported gastrointestinal events.. Added to metformin, albiglutide was well tolerated; produced superior reductions in HbA1c and FPG at week 104 compared with placebo, sitagliptin, and glimepiride; and resulted in weight loss compared with glimepiride. Topics: Aged; Body Weight; Diabetes Mellitus, Type 2; Double-Blind Method; Drug Therapy, Combination; Female; Glucagon-Like Peptide 1; Glycated Hemoglobin; Humans; Hyperglycemia; Hypoglycemic Agents; Male; Metformin; Middle Aged; Pyrazines; Sitagliptin Phosphate; Sulfonylurea Compounds; Treatment Outcome; Triazoles | 2014 |
Effect of renal impairment on the pharmacokinetics, efficacy, and safety of albiglutide.
Chronic kidney disease is frequently present in patients with type 2 diabetes mellitus (T2DM). New therapeutic options in this patient subpopulation are needed.. Assess the effect of renal impairment on the pharmacokinetics (PK), efficacy, and safety of albiglutide in single- and multiple-dose studies.. Pharmacokinetics, safety, and efficacy of once weekly albiglutide in patients with T2DM was assessed from a single-dose (30 mg), nonrandomized, open-label study (N = 41) including subjects with normal and varying degrees of renal impairment, including hemodialysis, and a pooled analysis of 4 phase 3, randomized, double-blind (1 open-label), active or placebo-controlled multiple-dose studies. The pooled analysis of the latter 4 studies (N = 1113) was part of the population PK analysis, which included subjects with normal and varying degrees of renal impairment (mild, moderate, severe) treated with albiglutide (30 to 50 mg) to primary end points of 26 to 52 weeks.. Single-dose PK showed area-under-the-curve ratios (and 90% CIs) of 1.32 (0.96-1.80), 1.39 (1.03-1.89), and 0.99 (0.63-1.57) for the moderate, severe, and hemodialysis groups, respectively, relative to the normal group. Results indicate that modest increases in plasma concentration of albiglutide were observed with the severity of renal impairment. There was a trend for more glycemic lowering as the estimated glomerular filtration rate decreased. The severe group had a higher frequency of gastrointestinal (eg, diarrhea, constipation, nausea, and vomiting) and hypoglycemic (with background sulfonylurea use) events compared with patients with mild or moderate renal impairment.. The PK, efficacy, and safety data indicate that albiglutide has a favorable benefit/risk ratio in patients with T2DM and varying degrees of renal impairment, and the need for a dose adjustment is not suggested. Experience in patients with more severe renal impairment is very limited, so the recommendation is to use albiglutide carefully in this population.. (ClinicalTrials.gov):NCT00938158, NCT00849017, NCT00838916, NCT00839527, NCT0198539. Topics: Adult; Aged; Area Under Curve; Blood Pressure; Diabetes Mellitus, Type 2; Dose-Response Relationship, Drug; Double-Blind Method; Female; Glomerular Filtration Rate; Glucagon-Like Peptide 1; Glycated Hemoglobin; Humans; Hypoglycemic Agents; Kidney Failure, Chronic; Male; Middle Aged; Multicenter Studies as Topic; Randomized Controlled Trials as Topic; Severity of Illness Index | 2014 |
Glucose-lowering effects and low risk of hypoglycemia in patients with maturity-onset diabetes of the young when treated with a GLP-1 receptor agonist: a double-blind, randomized, crossover trial.
The most common form of maturity-onset diabetes of the young (MODY), hepatocyte nuclear factor 1α (HNF1A diabetes: MODY3) is often treated with sulfonylureas that confer a high risk of hypoglycemia. We evaluated treatment with GLP-1 receptor agonists (GLP-1RAs) in patients with HNF1A diabetes.. Sixteen patients with HNF1A diabetes (8 women; mean age 39 years [range 23-67 years]; BMI 24.9 ± 0.5 kg/m(2) [mean ± SEM]; fasting plasma glucose [FPG] 9.9 ± 0.9 mmol/L; HbA1c 6.4 ± 0.2% [47 ± 3 mmol/mol]) received 6 weeks of treatment with a GLP-1RA (liraglutide) and placebo (tablets), as well as a sulfonylurea (glimepiride) and placebo (injections), in randomized order, in a double-blind, crossover trial. Glimepiride was up-titrated once weekly in a treat-to-target manner; liraglutide was up-titrated once weekly to 1.8 mg once daily. At baseline and at the end of each treatment period a standardized liquid meal test was performed, including a 30-min light bicycle test.. FPG decreased during the treatment periods (-1.6 ± 0.5 mmol/L liraglutide [P = 0.012] and -2.8 ± 0.7 mmol/L glimepiride [P = 0.003]), with no difference between treatments (P = 0.624). Postprandial plasma glucose (PG) responses (total area under the curve) were lower with both glimepiride (2,136 ± 292 min × mmol/L) and liraglutide (2,624 ± 340 min × mmol/L) compared with baseline (3,127 ± 291 min × mmol/L; P < 0.001, glimepiride; P = 0.017, liraglutide), with no difference between treatments (P = 0.121). Eighteen episodes of hypoglycemia (PG ≤3.9 mmol/L) occurred during glimepiride treatment and one during liraglutide treatment.. Six weeks of treatment with glimepiride or liraglutide lowered FPG and postprandial glucose excursions in patients with HNF1A diabetes. The glucose-lowering effect was greater with glimepiride at the expense of a higher risk of exclusively mild hypoglycemia. Topics: Adult; Aged; Blood Glucose; Cross-Over Studies; Diabetes Mellitus, Type 2; Double-Blind Method; Fasting; Female; Glucagon-Like Peptide 1; Glucagon-Like Peptide-1 Receptor; Glycated Hemoglobin; Humans; Hypoglycemia; Hypoglycemic Agents; Liraglutide; Male; Middle Aged; Postprandial Period; Receptors, Glucagon; Sulfonylurea Compounds; Young Adult | 2014 |
Impact of sitagliptin on carotid intima-media thickness in patients with coronary artery disease and impaired glucose tolerance or mild diabetes mellitus.
Sitagliptin has been widely used for the treatment of diabetes and shown recently to have beneficial pleiotropic outcomes on cardiovascular systems in experimental studies. However, little is known about the influence of sitagliptin on atherosclerosis-related cardiovascular diseases in a clinical setting. This study examined the effect of sitagliptin on carotid intima-media thickness (IMT). A total of 76 patients with clinically stable and documented coronary artery disease, who were newly diagnosed with impaired glucose tolerance or mild type 2 diabetes mellitus, were allocated, randomly, to receive either sitagliptin 100 mg/day or the placebo control. Common carotid IMT, glucose profiles, glycosylated hemoglobin (HbA1c), and lipid profiles were measured at baseline and repeated at 12 months. Sitagliptin-treated patients showed less IMT progression than the control group (p = 0.02). In addition, the sitagliptin group showed greater reductions in body weight (2.2%), 2-hour glucose levels on the 75-g oral glucose tolerance test (17.3%), HbA1c (4.7%), and low-density lipoprotein cholesterol levels (7.9%) from that at baseline. In conclusion, treatment with sitagliptin for 12 months was associated with a beneficial effect in the prevention of carotid IMT progression, compared with the diet control. Topics: Aged; Aged, 80 and over; Blood Glucose; Carotid Arteries; Coronary Angiography; Coronary Artery Disease; Diabetes Mellitus, Type 2; Dipeptidyl-Peptidase IV Inhibitors; Dose-Response Relationship, Drug; Female; Follow-Up Studies; Glucagon-Like Peptide 1; Glucose Tolerance Test; Humans; Male; Middle Aged; Prospective Studies; Pyrazines; Sitagliptin Phosphate; Time Factors; Treatment Outcome; Triazoles; Tunica Intima; Ultrasonography | 2014 |
Effect of treatment with sitagliptin on somatosensory-evoked potentials and metabolic control in patients with type 2 diabetes mellitus.
To evaluate the effect of sitagliptin on somatosensory-evoked potentials (SEPs) and metabolic control in patients with type 2 diabetes mellitus without clinical diabetic neuropathy.. Interventional, prospective, and open study. Patients with less than six months from the diagnosis were included. Examinations of SEPs and laboratory tests at fasting and after food stimulation were performed before and after three months of treatment with sitagliptin (100 mg/day).. There was a reduction in the mean levels of HbA1c (P < 0.0001), fasting glucose (P = 0.001), total cholesterol (P = 0.019), and ALT (P = 0.022). An increase in active GLP-1 was found at the end of the study (P = 0.0025). Several SEPs showed statistically significant differences when analyzed before and after treatment with sitagliptin.. The results give a glimpse of the possible use of sitagliptin in the treatment of some neurodegenerative conditions of the peripheral nervous system, in addition to its already established role in glycemic control. Topics: Activation, Metabolic; Adult; Alanine Transaminase; Area Under Curve; Aspartate Aminotransferases; Blood Glucose; Cholesterol; Diabetes Mellitus, Type 2; Evoked Potentials, Somatosensory; Fasting; Female; Food, Formulated; gamma-Glutamyltransferase; Glucagon-Like Peptide 1; Glycated Hemoglobin; Humans; Hypoglycemic Agents; Male; Middle Aged; Prospective Studies; Pyrazines; Sitagliptin Phosphate; Statistics, Nonparametric; Triazoles; Triglycerides | 2014 |
Liraglutide reverses pronounced insulin-associated weight gain, improves glycaemic control and decreases insulin dose in patients with type 2 diabetes: a 26 week, randomised clinical trial (ELEGANT).
The best treatment strategy for a patient with type 2 diabetes who shows pronounced weight gain after the introduction of insulin treatment is unclear. We determined whether addition of a glucagon-like peptide-1 (GLP-1) analogue could reverse pronounced insulin-associated weight gain while maintaining glycaemic control, and compared this with the most practised strategy, continuation and intensification of standard insulin therapy.. In a 26-week, randomised controlled trial (ELEGANT), conducted in the outpatient departments of one academic and one large non-academic teaching hospital in the Netherlands, adult patients with type 2 diabetes with ≥ 4% weight gain during short-term (≤ 16 months) insulin therapy received either open-label addition of liraglutide 1.8 mg/day (n = 26) or continued standard therapy (n = 24). A computer-generated random number list was used to allocate treatments. Participants were evaluated every 4-6 weeks for weight, glycaemic control and adverse events. The primary endpoint was between-group weight difference after 26 weeks of treatment (intention to treat).. Of 50 randomised patients (mean age 58 years, BMI 33 kg/m(2), HbA1c 7.4% [57 mmol/mol]), 47 (94%) completed the study; all patients were analysed. Body weight decreased by 4.5 kg with liraglutide and increased by 0.9 kg with standard therapy (mean difference -5.2 kg [95% CI -6.7, -3.6 kg]; p < 0.001). The respective changes in HbA1c were -0.77% (-8.4 mmol/mol) and +0.01% (+0.1 mmol/mol) (difference -0.74% [-8.1 mmol/mol]) ([95% CI -1.08%, -0.41%] [-11.8, -4.5 mmol/mol]; p < 0.001); respective changes in insulin dose were -29 U/day and +5 U/day (difference -33 U/day [95% CI -41, -25 U/day]; p < 0.001). In five patients (19%), insulin could be completely discontinued. Liraglutide was well tolerated; no severe adverse events or severe hypoglycaemia occurred.. In patients with pronounced insulin-associated weight gain, addition of liraglutide to their treatment regimen reverses weight, decreases insulin dose and improves glycaemic control, and hence seems a valuable therapeutic option compared with continuation of standard insulin treatment. Trial registration ClinicalTrials.gov NCT01392898. Funding The study was funded by Novo Nordisk. Topics: Aged; Blood Glucose; Diabetes Mellitus, Type 2; Female; Glucagon-Like Peptide 1; Humans; Hypoglycemic Agents; Insulin; Liraglutide; Male; Middle Aged; Weight Gain | 2014 |
Effect of exenatide, sitagliptin, or glimepiride on β-cell secretory capacity in early type 2 diabetes.
Agents that augment GLP-1 effects enhance glucose-dependent β-cell insulin production and secretion and thus are hoped to prevent progressive impairment in insulin secretion characteristic of type 2 diabetes (T2D). The purpose of this study was to evaluate GLP-1 effects on β-cell secretory capacity, an in vivo measure of functional β-cell mass, early in the course of T2D.. We conducted a randomized controlled trial in 40 subjects with early T2D who received the GLP-1 analog exenatide (n = 14), the dipeptidyl peptidase IV inhibitor sitagliptin (n = 12), or the sulfonylurea glimepiride (n = 14) as an active comparator insulin secretagogue for 6 months. Acute insulin responses to arginine (AIRarg) were measured at baseline and after 6 months of treatment with 5 days of drug washout under fasting, 230 mg/dL (glucose potentiation of arginine-induced insulin release [AIRpot]), and 340 mg/dL (maximum arginine-induced insulin release [AIRmax]) hyperglycemic clamp conditions, in which AIRmax provides the β-cell secretory capacity.. The change in AIRpot was significantly greater with glimepiride versus exenatide treatment (P < 0.05), and a similar trend was notable for the change in AIRmax (P = 0.1). Within each group, the primary outcome measure, AIRmax, was unchanged after 6 months of treatment with exenatide or sitagliptin compared with baseline but was increased with glimepiride (P < 0.05). α-Cell glucagon secretion (AGRmin) was also increased with glimepiride treatment (P < 0.05), and the change in AGRmin trended higher with glimepiride than with exenatide (P = 0.06).. After 6 months of treatment, exenatide or sitagliptin had no significant effect on functional β-cell mass as measured by β-cell secretory capacity, whereas glimepiride appeared to enhance β- and α-cell secretion. Topics: Adolescent; Adult; Aged; Diabetes Mellitus, Type 2; Exenatide; Female; Glucagon-Like Peptide 1; Glucagon-Secreting Cells; Glucose Tolerance Test; Humans; Hypoglycemic Agents; Insulin; Insulin-Secreting Cells; Male; Middle Aged; Peptides; Prognosis; Pyrazines; Sitagliptin Phosphate; Sulfonylurea Compounds; Triazoles; Venoms; Young Adult | 2014 |
Postprandial gallbladder emptying in patients with type 2 diabetes: potential implications for bile-induced secretion of glucagon-like peptide 1.
Recent preclinical work has suggested that postprandial flow of bile acids into the small intestine potentiates nutrient-induced glucagon-like peptide 1 (GLP1(GCG)) secretion via bile acid-induced activation of the G protein-coupled receptor TGR5 in intestinal L cells. The notion of bile-induced GLP1 secretion combined with the findings of reduced postprandial gallbladder emptying in patients with type 2 diabetes (T2DM) led us to speculate whether reduced postprandial GLP1 responses in some patients with T2DM arise as a consequence of diabetic gallbladder dysmotility.. In a randomised design, 15 patients with long-standing T2DM and 15 healthy age-, gender- and BMI-matched control subjects were studied during 75-g oral glucose tolerance test (OGTT) and three isocaloric (500 kcal) and isovolaemic (350 ml) liquid meals: i) 2.5 g fat, 107 g carbohydrate and 13 g protein; ii) 10 g fat, 93 g carbohydrate and 11 g protein; and iii) 40 g fat, 32 g carbohydrate and 3 g protein. Basal and postprandial plasma concentrations of glucose, insulin, C-peptide, glucagon, GLP1, glucose-dependent insulinotropic polypeptide (GIP), cholecystokinin and gastrin were measured. Furthermore, gallbladder emptying and gastric emptying were examined.. Gallbladder emptying increased with increasing meal fat content, but no intergroup differences were demonstrated. GIP and GLP1 responses were comparable among the groups with GIP levels being higher following high-fat meals, whereas GLP1 secretion was similar after both OGTT and meals.. In conclusion, patients with T2DM exhibited normal gallbladder emptying to meals with a wide range of fat content. Incretin responses were similar to that in controls, and an association with postprandial gallbladder contraction could not be demonstrated. Topics: Adult; Aged; Area Under Curve; Bile; Biomarkers; Blood Glucose; C-Peptide; Case-Control Studies; Cholecystokinin; Denmark; Diabetes Mellitus, Type 2; Dietary Fats; Female; Gallbladder Emptying; Gastric Emptying; Gastric Inhibitory Polypeptide; Gastrins; Glucagon; Glucagon-Like Peptide 1; Glucose Tolerance Test; Humans; Insulin; Male; Middle Aged; Postprandial Period; Receptors, G-Protein-Coupled | 2014 |
Novel gut-based pharmacology of metformin in patients with type 2 diabetes mellitus.
Metformin, a biguanide derivate, has pleiotropic effects beyond glucose reduction, including improvement of lipid profiles and lowering microvascular and macrovascular complications associated with type 2 diabetes mellitus (T2DM). These effects have been ascribed to adenosine monophosphate-activated protein kinase (AMPK) activation in the liver and skeletal muscle. However, metformin effects are not attenuated when AMPK is knocked out and intravenous metformin is less effective than oral medication, raising the possibility of important gut pharmacology. We hypothesized that the pharmacology of metformin includes alteration of bile acid recirculation and gut microbiota resulting in enhanced enteroendocrine hormone secretion. In this study we evaluated T2DM subjects on and off metformin monotherapy to characterize the gut-based mechanisms of metformin. Subjects were studied at 4 time points: (i) at baseline on metformin, (ii) 7 days after stopping metformin, (iii) when fasting blood glucose (FBG) had risen by 25% after stopping metformin, and (iv) when FBG returned to baseline levels after restarting the metformin. At these timepoints we profiled glucose, insulin, gut hormones (glucagon-like peptide-1 (GLP-1), peptide tyrosine-tyrosine (PYY) and glucose-dependent insulinotropic peptide (GIP) and bile acids in blood, as well as duodenal and faecal bile acids and gut microbiota. We found that metformin withdrawal was associated with a reduction of active and total GLP-1 and elevation of serum bile acids, especially cholic acid and its conjugates. These effects reversed when metformin was restarted. Effects on circulating PYY were more modest, while GIP changes were negligible. Microbiota abundance of the phylum Firmicutes was positively correlated with changes in cholic acid and conjugates, while Bacteroidetes abundance was negatively correlated. Firmicutes and Bacteroidetes representation were also correlated with levels of serum PYY. Our study suggests that metformin has complex effects due to gut-based pharmacology which might provide insights into novel therapeutic approaches to treat T2DM and associated metabolic diseases.. www.ClinicalTrials.gov NCT01357876. Topics: Adolescent; Adult; Aged; Bile Acids and Salts; Blood Glucose; Diabetes Mellitus, Type 2; Female; Glucagon-Like Peptide 1; Humans; Hypoglycemic Agents; Intestinal Mucosa; Intestines; Male; Metformin; Microbiota; Middle Aged; Peptide YY | 2014 |
Incretin, insulinotropic and glucose-lowering effects of whey protein pre-load in type 2 diabetes: a randomised clinical trial.
Since protein ingestion is known to stimulate the secretion of glucagon-like peptide-1 (GLP-1), we hypothesised that enhancing GLP-1 secretion to harness its insulinotropic/beta cell-stimulating activity with whey protein pre-load may have beneficial glucose-lowering effects in type 2 diabetes.. In a randomised, open-label crossover clinical trial, we studied 15 individuals with well-controlled type 2 diabetes who were not taking any medications except for sulfonylurea or metformin. These participants consumed, on two separate days, 50 g whey in 250 ml water or placebo (250 ml water) followed by a standardised high-glycaemic-index breakfast in a hospital setting. Participants were randomised using a coin flip. The primary endpoints of the study were plasma concentrations of glucose, intact GLP-1 and insulin during the 30 min following meal ingestion.. In each group, 15 patients were analysed. The results showed that over the whole 180 min post-meal period, glucose levels were reduced by 28% after whey pre-load with a uniform reduction during both early and late phases. Insulin and C-peptide responses were both significantly higher (by 105% and 43%, respectively) with whey pre-load. Notably, the early insulin response was 96% higher after whey. Similarly, both total GLP-1 (tGLP-1) and intact GLP-1 (iGLP-1) levels were significantly higher (by 141% and 298%, respectively) with whey pre-load. Dipeptidyl peptidase 4 plasma activity did not display any significant difference after breakfast between the groups.. In summary, consumption of whey protein shortly before a high-glycaemic-index breakfast increased the early prandial and late insulin secretion, augmented tGLP-1 and iGLP-1 responses and reduced postprandial glycaemia in type 2 diabetic patients. Whey protein may therefore represent a novel approach for enhancing glucose-lowering strategies in type 2 diabetes. Trial registration ClinicalTrials.gov NCT01571622 Funding The Israeli Ministry of Health and Milk Council funded the research. Topics: Aged; Blood Glucose; Cross-Over Studies; Diabetes Mellitus, Type 2; Female; Glucagon-Like Peptide 1; Humans; Incretins; Insulin; Male; Middle Aged; Milk Proteins; Whey Proteins | 2014 |
Once-weekly dulaglutide versus once-daily liraglutide in metformin-treated patients with type 2 diabetes (AWARD-6): a randomised, open-label, phase 3, non-inferiority trial.
Dulaglutide and liraglutide, both glucagon-like peptide-1 (GLP-1) receptor agonists, improve glycaemic control and reduce weight in patients with type 2 diabetes. In a head-to-head trial, we compared the safety and efficacy of once-weekly dulaglutide with that of once-daily liraglutide in metformin-treated patients with uncontrolled type 2 diabetes.. We did a phase 3, randomised, open-label, parallel-group study at 62 sites in nine countries between June 20, 2012, and Nov 25, 2013. Patients with inadequately controlled type 2 diabetes receiving metformin (≥1500 mg/day), aged 18 years or older, with glycated haemoglobin (HbA1c) 7·0% or greater (≥53 mmol/mol) and 10·0% or lower (≤86 mmol/mol), and body-mass index 45 kg/m(2) or lower were randomly assigned to receive once-weekly dulaglutide (1·5 mg) or once-daily liraglutide (1·8 mg). Randomisation was done according to a computer-generated random sequence with an interactive voice response system. Participants and investigators were not masked to treatment allocation. The primary outcome was non-inferiority (margin 0·4%) of dulaglutide compared with liraglutide for change in HbA1c (least-squares mean change from baseline) at 26 weeks. Safety data were collected for a further 4 weeks' follow-up. Analysis was by intention to treat. This study is registered with ClinicalTrials.gov, number NCT01624259.. We randomly assigned 599 patients to receive once-weekly dulaglutide (299 patients) or once-daily liraglutide (300 patients). 269 participants in each group completed treatment at week 26. Least-squares mean reduction in HbA1c was -1·42% (SE 0·05) in the dulaglutide group and -1·36% (0·05) in the liraglutide group. Mean treatment difference in HbA1c was -0·06% (95% CI -0·19 to 0·07, pnon-inferiority<0·0001) between the two groups. The most common gastrointestinal adverse events were nausea (61 [20%] in dulaglutide group vs 54 [18%] in liraglutide group), diarrhoea (36 [12%] vs 36 [12%]), dyspepsia (24 [8%] vs 18 [6%]), and vomiting (21 [7%] vs 25 [8%]), with similar rates of study or study drug discontinuation because of adverse events between the two groups (18 [6%] in each group). The hypoglycaemia rate was 0·34 (SE 1·44) and 0·52 (3·01) events per patient per year, respectively, and no severe hypoglycaemia was reported.. Once-weekly dulaglutide is non-inferior to once-daily liraglutide for least-squares mean reduction in HbA1c, with a similar safety and tolerability profile.. Eli Lilly and Company. Topics: Analysis of Variance; Blood Glucose; Diabetes Mellitus, Type 2; Drug Administration Schedule; Fasting; Female; Glucagon-Like Peptide 1; Glucagon-Like Peptides; Glycated Hemoglobin; Humans; Hypoglycemic Agents; Immunoglobulin Fc Fragments; Liraglutide; Male; Metformin; Middle Aged; Recombinant Fusion Proteins; Treatment Outcome | 2014 |
Comparison of the effects of slowly and rapidly absorbed carbohydrates on postprandial glucose metabolism in type 2 diabetes mellitus patients: a randomized trial.
Isomaltulose attenuates postprandial glucose and insulin concentrations compared with sucrose in patients with type 2 diabetes mellitus (T2DM). However, the mechanism by which isomaltulose limits postprandial hyperglycemia has not been clarified.. The objective was therefore to assess the effects of bolus administration of isomaltulose on glucose metabolism compared with sucrose in T2DM.. In a randomized, double-blind, crossover design, 11 participants with T2DM initially underwent a 3-h euglycemic-hyperinsulinemic (0.8 mU · kg(-1) · min(-1)) clamp that was subsequently combined with 1 g/kg body wt of an oral (13)C-enriched isomaltulose or sucrose load. Hormonal responses and glucose kinetics were analyzed during a 4-h postprandial period.. Compared with sucrose, absorption of isomaltulose was prolonged by ∼50 min (P = 0.004). Mean plasma concentrations of insulin, C-peptide, glucagon, and glucose-dependent insulinotropic peptide were ∼10-23% lower (P < 0.05). In contrast, glucagon-like peptide 1 (GLP-1) was ∼64% higher (P < 0.001) after isomaltulose ingestion, which results in an increased insulin-to-glucagon ratio (P < 0.001) compared with sucrose. The cumulative amount of systemic glucose appearance was ∼35% lower after isomaltulose than after sucrose (P = 0.003) because of the reduction in orally derived and endogenously produced glucose and a higher first-pass splanchnic glucose uptake (SGU). Insulin action was enhanced after isomaltulose compared with sucrose (P = 0.013).. Ingestion of slowly absorbed isomaltulose attenuates postprandial hyperglycemia by reducing oral glucose appearance, inhibiting endogenous glucose production (EGP), and increasing SGU compared with ingestion of rapidly absorbed sucrose in patients with T2DM. In addition, GLP-1 secretion contributes to a beneficial shift in the insulin-to-glucagon ratio, suppression of EGP, and enhancement of SGU after isomaltulose consumption. This trial was registered at clinicaltrials.gov as NCT01070238. Topics: Blood Glucose; C-Peptide; Carbohydrate Metabolism; Cross-Over Studies; Diabetes Mellitus, Type 2; Dietary Carbohydrates; Double-Blind Method; Female; Gastric Inhibitory Polypeptide; Glucagon; Glucagon-Like Peptide 1; Humans; Hyperglycemia; Insulin; Isomaltose; Male; Middle Aged; Postprandial Period; Sucrose | 2014 |
Effects of sitagliptin therapy on markers of low-grade inflammation and cell adhesion molecules in patients with type 2 diabetes.
Inflammation and endothelial dysfunction are increasingly being recognized as key etiological factors in the development of atherosclerosis and subsequent cardiovascular disease. These pro-atherogenic factors are strongly correlated and are often found to co-segregate in patients with type 2 diabetes. The impact of sitagliptin, a selective inhibitor of dipeptidyl peptidase-4, on inflammation and markers of endothelial function remains to be fully characterized.. The objective of the present study was to examine the effects of treatment with sitagliptin on the plasma levels of various markers of low-grade inflammation and cell adhesion molecules in patients with type 2 diabetes.. Thirty-six subjects with type 2 diabetes (30 men/6 postmenopausal women with a mean age of 58.1 ± 6.4 years and a body mass index of 30.7 ± 4.9 kg/m²) were recruited into this double-blind, cross-over study using sitagliptin (100mg/d) or placebo, each for a 6-week period, including a 4-week washout period between the two phases. Blood samples were taken at the end of each phase of treatment. Compared with placebo, treatment with sitagliptin significantly reduced the plasma levels of C-reactive protein (CRP) (44.9%, P=0.006), interleukin (IL)-6 (24.7%, P=0.04), IL-18 (7.3%, P=0.004), secreted phospholipase-A₂ (sPLA₂) (12.9%, P=0.04), soluble intercellular adhesion molecule-1 (5.3%, P=0.002), and E-selectin (5.9%, P=0.005). A significant inverse correlation was found between changes in glucagon-like peptide-1 (GLP-1) and changes in CRP levels (r=0.41, P=0.01) following sitagliptin therapy. Sitagliptin therapy had more pronounced effects in subjects with higher levels of inflammatory markers and cell adhesion molecules compared with subjects with lower levels.. Treatment with sitagliptin for 6 weeks reduced plasma markers of low-grade inflammation and cell adhesion molecules, most likely by increasing plasma GLP-1 levels and improving glucose-insulin homeostasis. These beneficial effects of sitagliptin might represent a further advantage in the management of diabetes and its proatherogenic comorbidities. Topics: Anti-Inflammatory Agents, Non-Steroidal; Biomarkers; Cell Adhesion Molecules; Cross-Over Studies; Diabetes Mellitus, Type 2; Dipeptidyl-Peptidase IV Inhibitors; Double-Blind Method; Down-Regulation; E-Selectin; Endothelium, Vascular; Female; Glucagon-Like Peptide 1; Humans; Inflammation Mediators; Intercellular Adhesion Molecule-1; Male; Middle Aged; Phospholipases A2, Secretory; Pyrazines; Sitagliptin Phosphate; Solubility; Triazoles | 2014 |
Liraglutide's safety, tolerability, pharmacokinetics, and pharmacodynamics in pediatric type 2 diabetes: a randomized, double-blind, placebo-controlled trial.
The prevalence of type 2 diabetes (T2D) in youth is increasing. Treatment options beyond metformin and insulin are needed. The safety, tolerability, pharmacokinetics, and pharmacodynamics of liraglutide once daily in youth (10-17 years old) with T2D were investigated in a randomized, double-blind, placebo-controlled trial.. Youth treated with diet/exercise alone or with metformin and having a hemoglobin A1c (HbA1c) level of 6.5-11% were randomized to liraglutide (n=14) or placebo (n=7). Starting at 0.3 mg/day, doses were escalated weekly to 0.6, 0.9, 1.2, and 1.8 mg/day (or placebo equivalent) for 5 weeks.. Nineteen participants completed the trial. Baseline characteristics were similar between groups, with mean (SD) values for age of 14.8 (2.2) years, weight of 113.2 (35.6) kg (range, 57-214 kg), diabetes duration of 1.7 (1.4) years, and HbA1c level of 8.1% (1.2%). No serious adverse events (AEs), including severe hypoglycemia, occurred. Transient gastrointestinal AEs were most common at lower liraglutide doses during dose escalation. No significant changes in safety and tolerability parameters occurred. There was no evidence of pancreatitis or lipase elevations above three times the upper normal limit; calcitonin levels remained within the normal range. For liraglutide 1.8 mg, mean half-life was 12 h, and clearance was 1.7 L/h. After 5 weeks, the decline in HbA1c level was greater with liraglutide versus placebo (-0.86 vs. 0.04%, P=0.0007), whereas mean body weight remained stable (-0.50 vs. -0.54 kg, P=0.9703).. Liraglutide was well tolerated in youth with T2D, with safety, tolerability, and pharmacokinetic profiles similar to profiles in adults. Topics: Adolescent; Age of Onset; Belgium; Blood Glucose; Body Weight; Child; Diabetes Mellitus, Type 2; Dose-Response Relationship, Drug; Double-Blind Method; Glucagon-Like Peptide 1; Glycated Hemoglobin; Humans; Hypoglycemic Agents; Liraglutide; Pediatric Obesity; Prevalence; Slovenia; Treatment Outcome; United Kingdom; United States; Weight Loss | 2014 |
Glycemic/metabolic responses to identical meal tolerance tests at breakfast, lunch and dinner in Japanese patients with type 2 diabetes mellitus treated with a dipeptidyl peptidase-4 inhibitor and the effects of adding a mitiglinide/voglibose fixed-dose c
The effects of the mitiglinide/voglibose fixed-dose combination on postprandial glycemic/metabolic responses in patients with type 2 diabetes mellitus (T2DM) treated with dipeptidyl peptidase-4 (DPP-4) inhibitors are unknown.. Twelve T2DM patients treated with a DPP-4 inhibitor underwent identical meal tolerance tests (MTTs) at breakfast, lunch and dinner, before and 2 - 3 weeks after treatment with a fixed-dose combination of mitiglinide 10 mg and voglibose 0.2 mg (combination). Patients were randomized in a cross-over fashion to administer the combination either three-times-daily before each meal or twice-daily before breakfast and dinner. Glycemic/metabolic responses were evaluated at 0, 30, 60 and 120 min in each MTT.. Three-times-daily administration of the combination significantly suppressed postprandial hyperglycemia after each meal, particularly after lunch and dinner. Active glucagon-like peptide-1 levels increased significantly after each meal, as did early-phase insulin secretion without excessive insulin secretion. Postprandial hyperglycemia after lunch was significantly greater after twice-daily than three-times-daily administration, but there were no clinically relevant differences in other metabolic responses.. This study revealed that adding the mitiglinide/voglibose combination to a DPP-4 inhibitor elicited additive improvements in postprandial glycemic/metabolic responses assessed using MTTs at breakfast, lunch and dinner with identical meal compositions. Topics: Aged; Blood Glucose; Breakfast; Diabetes Mellitus, Type 2; Dipeptidyl-Peptidase IV Inhibitors; Drug Combinations; Drug Therapy, Combination; Female; Glucagon-Like Peptide 1; Humans; Hyperglycemia; Hypoglycemic Agents; Inositol; Insulin; Insulin Secretion; Isoindoles; Lunch; Male; Meals; Middle Aged; Postprandial Period | 2014 |
Efficacy and safety of the once-weekly GLP-1 receptor agonist albiglutide versus sitagliptin in patients with type 2 diabetes and renal impairment: a randomized phase III study.
To evaluate weekly subcutaneous albiglutide versus daily sitagliptin in renally impaired patients with type 2 diabetes and inadequately controlled glycemia on a regimen of diet and exercise and/or oral antihyperglycemic medications.. In this phase III, randomized, double-blind, multicenter, 52-week study, the primary study end point was HbA1c change from baseline at week 26 in patients with renal impairment, as assessed with estimated glomerular filtration rate and categorized as mild, moderate, or severe (≥60 to ≤89, ≥30 to ≤59, and ≥15 to ≤29 mL/min/1.73 m(2), respectively). Secondary end points included fasting plasma glucose (FPG), weight, achievement of treatment targets, hyperglycemic rescue, and safety.. Baseline demographics were similar across treatment and renal impairment groups with overall mean age of 63.3 years, BMI of 30.4 kg/m(2), HbA1c of 8.2% (66 mmol/mol), and diabetes disease duration of 11.2 years. HbA1c change from baseline at week 26 was significantly greater for albiglutide than sitagliptin (-0.83% vs. -0.52%, P = 0.0003). Decreases in HbA1c, FPG, and weight were seen through week 52. Time to hyperglycemic rescue through week 52 was significantly longer for albiglutide than sitagliptin (P = 0.0017). Results of safety assessments were similar between groups, and most adverse events (AEs) were mild or moderate. The incidences of gastrointestinal AEs for albiglutide and sitagliptin were as follows: overall, 31.7%, 25.2%; diarrhea, 10.0%, 6.5%; nausea, 4.8%, 3.3%; and vomiting, 1.6%, 1.2%, respectively.. Once-weekly albiglutide therapy in renally impaired patients with type 2 diabetes provided statistically superior glycemic improvement with almost similar tolerability compared with daily sitagliptin therapy. Topics: Aged; Blood Glucose; Diabetes Mellitus, Type 2; Diabetic Nephropathies; Double-Blind Method; Drug Administration Schedule; Female; Glucagon-Like Peptide 1; Glucagon-Like Peptide-1 Receptor; Glycated Hemoglobin; Humans; Hypoglycemic Agents; Male; Middle Aged; Pyrazines; Receptors, Glucagon; Renal Insufficiency; Sitagliptin Phosphate; Treatment Outcome; Triazoles | 2014 |
Contribution of liraglutide in the fixed-ratio combination of insulin degludec and liraglutide (IDegLira).
Insulin degludec/liraglutide (IDegLira) is a novel combination of insulin degludec (IDeg) and liraglutide. This trial investigated the contribution of the liraglutide component of IDegLira versus IDeg alone on efficacy and safety in patients with type 2 diabetes.. In a 26-week, double-blind trial, patients with type 2 diabetes (A1C 7.5-10.0% [58-86 mmol/mol]) on basal insulin (20-40 units) and metformin with or without sulfonylurea/glinides were randomized (1:1) to once-daily IDegLira + metformin or IDeg + metformin with titration aiming for fasting plasma glucose between 4 and 5 mmol/L. Maximum allowed doses were 50 dose steps (equal to 50 units IDeg plus 1.8 mg liraglutide) and 50 units for IDeg. The primary end point was change in A1C from baseline.. A total of 413 patients were randomized (mean A1C 8.8% [73 mmol/mol]; BMI 33.7 kg/m2). IDeg dose, alone or as part of IDegLira, was equivalent (45 units). A1C decreased by 1.9% (21 mmol/mol) with IDegLira and by 0.9% (10 mmol/mol) with IDeg (estimated treatment difference -1.1% [95% CI -1.3, -0.8], -12 mmol/mol [95% CI -14, -9; P < 0.0001). Mean weight reduction with IDegLira was 2.7 kg vs. no weight change with IDeg, P < 0.0001. Hypoglycemia incidence was comparable (24% for IDegLira vs. 25% for IDeg). Overall adverse events were similar, and incidence of nausea was low in both groups (IDegLira 6.5% vs. IDeg 3.5%).. IDegLira achieved glycemic control superior to that of IDeg at equivalent insulin doses without higher risk of hypoglycemia and with the benefit of weight loss. These findings establish the efficacy and safety of IDegLira and the distinct contribution of the liraglutide component. Topics: Aged; Blood Glucose; Diabetes Mellitus, Type 2; Double-Blind Method; Drug Combinations; Drug Therapy, Combination; Female; Glucagon-Like Peptide 1; Humans; Hypoglycemia; Hypoglycemic Agents; Insulin, Long-Acting; Liraglutide; Male; Metformin; Middle Aged; Sulfonylurea Compounds; Treatment Outcome; Weight Loss | 2014 |
Efficacy and safety of once-weekly glucagon-like peptide 1 receptor agonist albiglutide (HARMONY 1 trial): 52-week primary endpoint results from a randomized, double-blind, placebo-controlled trial in patients with type 2 diabetes mellitus not controlled
To show that albiglutide, a glucagon-like peptide-1 receptor agonist, is an effective and generally safe treatment to improve glycaemic control in patients with type 2 diabetes mellitus whose hyperglycaemia is inadequately controlled with pioglitazone (with or without metformin).. In this 3-year, randomized, double-blind, placebo-controlled study, 310 adult patients on a regimen of pioglitazone (with or without metformin) were randomly assigned to receive additional treatment with albiglutide [30 mg subcutaneous (s.c.) once weekly, n = 155] or matching placebo (n = 155). The primary efficacy endpoint was change from baseline to week 52 (intention-to-treat) in glycated haemoglobin (HbA1c).. The model-adjusted change from baseline in HbA1c at week 52 was significantly better with albiglutide than with placebo (-0.8%, 95% confidence interval -1.0, -0.6; p < 0.0001). Change from baseline fasting plasma glucose was -1.3 mmol/l in the albiglutide group and +0.4 mmol/l in the placebo group (p < 0.0001); a significantly higher percentage of patients reached the HbA1c goals with albiglutide (p < 0.0001), and the rate of hyperglycaemia rescue up to week 52 for albiglutide was 24.4 versus 47.7% for placebo (p < 0.0001). Albiglutide plus pioglitazone had no impact on weight, and severe hypoglycaemia was observed rarely (n = 2). With few exceptions, the results of safety assessments were similar between the groups, and most adverse events (AEs) were mild or moderate. The 52-week incidence rates for gastrointestinal AEs for albiglutide and placebo were: 31.3 and 29.8%, respectively (diarrhoea: 11.3 and 8.6%; nausea: 10.7 and 11.3%; vomiting: 4.0 and 4.0%).. Albiglutide 30 mg administered once weekly as an add-on to pioglitazone (with or without metformin) provided effective and durable glucose lowering and was generally well tolerated. Topics: Blood Glucose; Diabetes Mellitus, Type 2; Double-Blind Method; Drug Administration Schedule; Drug Therapy, Combination; Female; Glucagon-Like Peptide 1; Humans; Hypoglycemia; Hypoglycemic Agents; Incretins; Male; Metformin; Middle Aged; Pioglitazone; Thiazolidinediones; Treatment Outcome | 2014 |
Study of postprandial lipaemia in type 2 diabetes mellitus: exenatide versus liraglutide.
Therapeutic approaches based on the actions of the incretin hormone GLP-1 have been widely established in the management of T2DM. Nevertheless, much less research has been aimed at elucidating the role of GLP-1 in lipid metabolism and in particular postprandial dyslipidemia. Exenatide and liraglutide are two GLP-1 receptor agonists which are currently available as subcutaneously administered treatment for T2DM but their chronic effects on postprandial lipaemia have not been well investigated. The aim of this study is to examine the effect of treatment with either liraglutide or exenatide for two weeks on postprandial lipaemia in obese subjects with T2DM. This study was a single-center, two-armed, randomized, controlled 2-week prospective intervention trial in 20 subjects with T2DM. Patients were randomized to receive either liraglutide or exenatide treatment and underwent a standardized meal tolerance test early in the morning after 10 h fast at baseline (visit 1, beginning of treatment) and after a two-week treatment period (visit 2). Exenatide and liraglutide both appear to be equally effective in lowering postprandial lipaemia after the first administration and after a two-week treatment. The mechanisms which lead to this phenomenon, which seem to be independent of gastric emptying, are yet to be studied. Topics: Adult; Aged; Diabetes Complications; Diabetes Mellitus, Type 2; Exenatide; Female; Glucagon-Like Peptide 1; Humans; Hyperlipidemias; Hypoglycemic Agents; Liraglutide; Male; Middle Aged; Peptides; Postprandial Period; Prospective Studies; Time Factors; Treatment Outcome; Venoms | 2014 |
Mechanism of increase in plasma intact GLP-1 by metformin in type 2 diabetes: stimulation of GLP-1 secretion or reduction in plasma DPP-4 activity?
Metformin was reported to increase plasma intact glucagon-like peptide-1 (GLP-1) concentrations in type 2 diabetes. This is, at least partly, attributable to stimulation of GLP-1 secretion. A reduction in soluble dipeptidyl peptidase-4 activity may also make a modest contribution. Topics: Blood Glucose; Cross-Over Studies; Diabetes Mellitus, Type 2; Dipeptidyl Peptidase 4; Glucagon-Like Peptide 1; Humans; Hypoglycemic Agents; Male; Metformin; Middle Aged; Retrospective Studies | 2014 |
Efficacy and safety of a fixed-ratio combination of insulin degludec and liraglutide (IDegLira) compared with its components given alone: results of a phase 3, open-label, randomised, 26-week, treat-to-target trial in insulin-naive patients with type 2 di
A fixed-ratio combination of the basal insulin analogue insulin degludec and the glucagon-like peptide-1 (GLP-1) analogue liraglutide has been developed as a once-daily injection for the treatment of type 2 diabetes. We aimed to compare combined insulin degludec-liraglutide (IDegLira) with its components given alone in insulin-naive patients.. In this phase 3, 26-week, open-label, randomised trial, adults with type 2 diabetes, HbA1c of 7-10% (inclusive), a BMI of 40 kg/m(2) or less, and treated with metformin with or without pioglitazone were randomly assigned (2:1:1) to daily injections of IDegLira, insulin degludec, or liraglutide (1·8 mg per day). IDegLira and insulin degludec were titrated to achieve a self-measured prebreakfast plasma glucose concentration of 4-5 mmol/L. The primary endpoint was change in HbA1c after 26 weeks of treatment, and the main objective was to assess the non-inferiority of IDegLira to insulin degludec (with an upper 95% CI margin of 0·3%), and the superiority of IDegLira to liraglutide (with a lower 95% CI margin of 0%). This study is registered with ClinicalTrials.gov, number NCT01336023.. 1663 adults (mean age 55 years [SD 10], HbA1c 8·3% [0·9], and BMI 31·2 kg/m(2) [4·8]) were randomly assigned, 834 to IDegLira, 414 to insulin degludec, and 415 to liraglutide. After 26 weeks, mean HbA1c had decreased by 1·9% (SD 1·1) to 6·4% (1·0) with IDegLira, by 1·4% (1·0) to 6·9% (1·1) with insulin degludec, and by 1·3% (1·1) to 7·0% (1·2) with liraglutide. IDegLira was non-inferior to insulin degludec (estimated treatment difference -0·47%, 95% CI -0·58 to -0·36, p<0·0001) and superior to liraglutide (-0·64%, -0·75 to -0·53, p<0·0001). IDegLira was generally well tolerated; fewer participants in the IDegLira group than in the liraglutide group reported gastrointestinal adverse events (nausea 8·8 vs 19·7%), although the insulin degludec group had the fewest participants with gastrointestinal adverse events (nausea 3·6%). We noted no clinically relevant differences between treatments with respect to standard safety assessments, and the safety profile of IDegLira reflected those of its component parts. The number of confirmed hypoglycaemic events per patient year was 1·8 for IDegLira, 0·2 for liraglutide, and 2·6 for insulin degludec. Serious adverse events occurred in 19 (2%) of 825 patients in the IDegLira group, eight (2%) of 412 in the insulin degludec group, and 14 (3%) of 412 in the liraglutide group.. IDegLira combines the clinical advantages of basal insulin and GLP-1 receptor agonist treatment, resulting in improved glycaemic control compared with its components given alone.. Novo Nordisk. Topics: Blood Glucose; Diabetes Mellitus, Type 2; Drug Combinations; Female; Glucagon-Like Peptide 1; Glycated Hemoglobin; Humans; Hypoglycemic Agents; Insulin, Long-Acting; Liraglutide; Male; Middle Aged; Treatment Outcome | 2014 |
HARMONY 4: randomised clinical trial comparing once-weekly albiglutide and insulin glargine in patients with type 2 diabetes inadequately controlled with metformin with or without sulfonylurea.
The aim of this study was to compare the efficacy and safety of once-weekly albiglutide with once-daily insulin glargine (A21Gly,B31Arg,B32Arg human insulin) in patients with type 2 diabetes inadequately controlled on metformin with or without sulfonylurea.. This was a randomised, open-label, multicentre (n = 222), parallel-group, non-inferiority out-patient clinical trial, with 779 patients enrolled in the study. The study was conducted in 222 centres located in four countries. Patients aged ≥18 years with type 2 diabetes treated with metformin (±sulfonylurea) for at least 3 months with a baseline HbA1c 7.0-10.0% (53.0-85.8 mmol/mol) were randomly assigned (2:1) via a computer-generated randomisation sequence with a voice response system to receive albiglutide (30 mg once a week, n = 504) or insulin glargine (10 U once a day, n = 241) added to current therapy. Participants and investigators were not masked to treatment assignment. Doses of each medication were adjusted on the basis of the glycaemic response. The primary endpoint was change from baseline in HbA1c at week 52.. In the albiglutide group, HbA1c declined from 8.28 ± 0.90% (67.0 ± 9.8 mmol/mol) (mean ± SD) at baseline to 7.62 ± 1.12% (59.8 ± 12.2 mmol/mol) at week 52. A similar reduction occurred in the insulin glargine group (8.36 ± 0.95% to 7.55 ± 1.04% [67.9 ± 10.4 to 59.0 ± 11.4 mmol/mol]). The model-adjusted treatment difference of 0.11% (95% CI -0.04%, 0.27%) (1.2 mmol/mol [95% CI -0.4, 3.0 mmol/mol]) indicated non-inferiority of albiglutide to insulin glargine based on the pre-specified non-inferiority margin of 0.3% (3.3 mmol/mol, p = 0.0086). Body weight increased in the insulin glargine group and decreased in the albiglutide group, with a mean treatment difference of -2.61 kg (95% CI -3.20, -2.02; p < 0.0001). Documented symptomatic hypoglycaemia occurred in a higher proportion of patients in the insulin glargine group than in the albiglutide group (27.4% vs 17.5%, p = 0.0377).. Albiglutide was non-inferior to insulin glargine at reducing HbA1c at week 52, with modest weight loss and less hypoglycaemia. Both drugs were well tolerated. Albiglutide may be considered an alternative to insulin glargine in this patient population.. ClinicalTrials.gov NCT00838916 (completed). This study was planned and conducted by GlaxoSmithKline. Topics: Adolescent; Adult; Aged; Aged, 80 and over; Blood Glucose; Diabetes Mellitus, Type 2; Drug Administration Schedule; Drug Therapy, Combination; Female; Glucagon-Like Peptide 1; Humans; Hypoglycemic Agents; Insulin Glargine; Insulin, Long-Acting; Male; Metformin; Middle Aged; Retreatment; Sulfonylurea Compounds; Treatment Outcome; Young Adult | 2014 |
The effect of liraglutide on endothelial function in patients with type 2 diabetes.
This single-centre, 12-week, double-blind, placebo-controlled trial assessed how the human glucagon-like-peptide 1 analogue liraglutide impacted endothelial function in adult patients (n = 49) with type 2 diabetes and no overt cardiovascular disease. Patients were randomized to liraglutide, placebo or glimepiride. At baseline and Week 12, venous occlusion plethysmography was used to measure forearm blood flow (FBF) in response to acetylcholine (ACh) and sodium nitroprusside (SNP) before and after (L)-N(G)-monomethyl arginine (L-NMMA) infusion. At Week 12, ACh-mediated FBF increased with liraglutide and decreased with placebo; however, the between-treatment difference was not significant (p = 0.055). Inhibition of ACh-mediated FBF after L-NMMA infusion increased with liraglutide and decreased with placebo; this between-treatment difference was also not significant (p = 0.149). No change in FBF was observed with SNP. Liraglutide did not significantly impact endothelium-dependent vasodilation after 12 weeks; however, additional investigations looking at the effect of liraglutide on endothelial function in alternative vasculature and during the postprandial period are warranted. Topics: Acetylcholine; Aged; Blood Glucose; Blood Pressure; Body Weight; C-Peptide; Diabetes Mellitus, Type 2; Endothelium, Vascular; Female; Glucagon; Glucagon-Like Peptide 1; Glucose Clamp Technique; Humans; Hypoglycemic Agents; Insulin; Lipids; Liraglutide; Male; Middle Aged; Nitroprusside; Plethysmography | 2014 |
Differential acute postprandial effects of processed meat and isocaloric vegan meals on the gastrointestinal hormone response in subjects suffering from type 2 diabetes and healthy controls: a randomized crossover study.
The intake of meat, particularly processed meat, is a dietary risk factor for diabetes. Meat intake impairs insulin sensitivity and leads to increased oxidative stress. However, its effect on postprandial gastrointestinal hormone (GIH) secretion is unclear. We aimed to investigate the acute effects of two standardized isocaloric meals: a processed hamburger meat meal rich in protein and saturated fat (M-meal) and a vegan meal rich in carbohydrates (V-meal). We hypothesized that the meat meal would lead to abnormal postprandial increases in plasma lipids and oxidative stress markers and impaired GIH responses.. In a randomized crossover study, 50 patients suffering from type 2 diabetes (T2D) and 50 healthy subjects underwent two 3-h meal tolerance tests. For statistical analyses, repeated-measures ANOVA was performed.. The M-meal resulted in a higher postprandial increase in lipids in both groups (p<0.001) and persistent postprandial hyperinsulinemia in patients with diabetes (p<0.001). The plasma glucose levels were significantly higher after the V-meal only at the peak level. The plasma concentrations of glucose-dependent insulinotropic peptide (GIP), peptide tyrosine-tyrosine (PYY) and pancreatic polypeptide (PP) were higher (p<0.05, p<0.001, p<0.001, respectively) and the ghrelin concentration was lower (p<0.001) after the M-meal in healthy subjects. In contrast, the concentrations of GIP, PYY and PP were significantly lower after the M-meal in T2D patients (p<0.001). Compared with the V-meal, the M-meal was associated with a larger increase in lipoperoxidation in T2D patients (p<0.05).. Our results suggest that the diet composition and the energy content, rather than the carbohydrate count, should be important considerations for dietary management and demonstrate that processed meat consumption is accompanied by impaired GIH responses and increased oxidative stress marker levels in diabetic patients.. ClinicalTrials.gov NCT01572402. Topics: Blood Glucose; Diabetes Mellitus, Type 2; Diet, Vegan; Female; Food Handling; Gastric Inhibitory Polypeptide; Gastrointestinal Hormones; Ghrelin; Glucagon-Like Peptide 1; Humans; Insulin; Lipids; Male; Meat; Middle Aged; Postprandial Period; Triglycerides | 2014 |
Liraglutide and the preservation of pancreatic β-cell function in early type 2 diabetes: the LIBRA trial.
Clinical studies evaluating the effects of medications on β-cell function in type 2 diabetes (T2DM) are compromised by an inability to determine the actual baseline degree of β-cell dysfunction independent of the reversible dysfunction induced by hyperglycemia (glucotoxicity). Short-term intensive insulin therapy (IIT) is a strategy for eliminating glucotoxicity before randomization. This study determined whether liraglutide can preserve β-cell function over 48 weeks in early T2DM following initial elimination of glucotoxicity with IIT.. In this double-blind, randomized, placebo-controlled trial, 51 patients with T2DM of 2.6 ± 1.9 years' duration and an A1C of 6.8 ± 0.8% (51 ± 8.7 mmol/mol) completed 4 weeks of IIT before randomization to daily subcutaneous liraglutide or placebo injection, with serial assessment of β-cell function by Insulin Secretion-Sensitivity Index-2 (ISSI-2) on oral glucose tolerance test performed every 12 weeks.. The primary outcome of baseline-adjusted ISSI-2 at 48 weeks was higher in the liraglutide group than in the placebo group (339.8 ± 27.8 vs. 229.3 ± 28.4, P = 0.008). Baseline-adjusted HbA1c at 48 weeks was lower in the liraglutide group (6.2 ± 0.1% vs. 6.6 ± 0.1%, P = 0.055) (44 ± 1.1 vs. 49 ± 1.1 mmol/mol). At each quarterly assessment, >50% of participants on liraglutide had an HbA1c ≤6.0% (42 mmol/mol) and glucose tolerance in the nondiabetic range. Despite this level of glycemic control, no difference was found in the incidence of hypoglycemia between the liraglutide and placebo groups (P = 0.61). Two weeks after stopping treatment, however, the beneficial effect on ISSI-2 of liraglutide versus placebo was entirely lost (191.9 ± 24.7 vs. 238.1 ± 25.2, P = 0.20).. Liraglutide provides robust enhancement of β-cell function that is sustained over 48 weeks in early T2DM but lost upon cessation of therapy. Topics: Adult; Aged; Blood Glucose; Cytoprotection; Diabetes Mellitus, Type 2; Disease Progression; Double-Blind Method; Female; Glucagon-Like Peptide 1; Humans; Hypoglycemia; Hypoglycemic Agents; Insulin; Insulin Resistance; Insulin-Secreting Cells; Liraglutide; Male; Middle Aged | 2014 |
LEADER 3--lipase and amylase activity in subjects with type 2 diabetes: baseline data from over 9000 subjects in the LEADER Trial.
This report from the LEADER (Liraglutide Effect and Action in Diabetes: Evaluation of Cardiovascular Outcome Results) trial describes baseline lipase and amylase activity in type 2 diabetic subjects without acute pancreatitis symptoms before randomization to the glucagonlike peptide analog liraglutide or placebo.. The LEADER is an international randomized placebo-controlled trial evaluating the cardiovascular safety of liraglutide in 9340 type 2 diabetic patients at high cardiovascular risk. Fasting lipase and amylase activity was assessed at baseline, before receiving liraglutide or placebo, using a commercial assay (Roche) with upper limit of normal values of 63 U/L for lipase and 100 U/L for amylase.. Either or both enzymes were above the upper limit of normal in 22.7% of subjects; 16.6% (n = 1540) had an elevated lipase level (including 1.2% >3-fold elevated), and 11.8% (n = 1094) had an elevated amylase level (including 0.2% >3-fold elevated). In multivariable regression models, severely reduced kidney function was associated with the largest effect on increasing activity of both. However, even among subjects with normal kidney function, 12.2% and 7.7% had elevated lipase and amylase levels.. In this large study of type 2 diabetic patients, nearly 25% had elevated lipase or amylase levels without symptoms of acute pancreatitis. The clinician must take these data into account when evaluating abdominal symptoms in type 2 diabetic patients. Topics: Acute Disease; Aged; Amylases; Biomarkers; Diabetes Mellitus, Type 2; Double-Blind Method; Fasting; Female; Glucagon-Like Peptide 1; Humans; Hypoglycemic Agents; Kidney; Lipase; Liraglutide; Male; Middle Aged; Pancreatitis | 2014 |
The protective effect of the Mediterranean diet on endothelial resistance to GLP-1 in type 2 diabetes: a preliminary report.
In type 2 diabetes, acute hyperglycemia worsens endothelial function and inflammation,while resistance to GLP-1 action occurs. All these phenomena seem to be related to the generation of oxidative stress. A Mediterranean diet, supplemented with olive oil, increases plasma antioxidant capacity, suggesting that its implementation can have a favorable effect on the aforementioned phenomena. In the present study, we test the hypothesis that a Mediterranean diet using olive oil can counteract the effects of acute hyperglycemia and can improve the resistance of the endothelium to GLP-1 action.. Two groups of type 2 diabetic patients, each consisting of twelve subjects, participated in a randomized trial for three months, following a Mediterranean diet using olive oil or a control low-fat diet. Plasma antioxidant capacity, endothelial function, nitrotyrosine, 8-iso-PGF2a, IL-6 and ICAM-1 levels were evaluated at baseline and at the end of the study. The effect of GLP-1 during a hyperglycemic clamp, was also studied at baseline and at the end of the study.. Compared to the control diet, the Mediterranean diet increased plasma antioxidant capacity and improved basal endothelial function, nitrotyrosine, 8-iso-PGF2a, IL-6 and ICAM-1 levels. The Mediterranean diet also reduced the negative effects of acute hyperglycemia, induced by a hyperglycemic clamp, on endothelial function, nitrotyrosine, 8-iso-PGF2a, IL-6 and ICAM-1 levels. Furthermore, the Mediterranean diet improved the protective action of GLP-1 on endothelial function, nitrotyrosine, 8-iso-PGF2a, IL-6 and ICAM-1 levels, also increasing GLP-1-induced insulin secretion.. These data suggest that the Mediterranean diet, using olive oil, prevents the acute hyperglycemia effect on endothelial function, inflammation and oxidative stress, and improves the action of GLP-1, which may have a favorable effect on the management of type 2 diabetes, particularly for the prevention of cardiovascular disease. Topics: Adult; Aged; Blood Glucose; Cardiovascular Diseases; Diabetes Mellitus, Type 2; Diet, Mediterranean; Drug Resistance; Endothelium, Vascular; Female; Glucagon-Like Peptide 1; Humans; Hyperglycemia; Inflammation; Male; Middle Aged; Oxidative Stress | 2014 |
Study protocol of a randomised controlled trial comparing perioperative intravenous insulin, GIK or GLP-1 treatment in diabetes-PILGRIM trial.
Diabetes mellitus (DM) is associated with poor outcome after surgery. The prevalence of DM in hospitalised patients is up to 40%, meaning that the anaesthesiologist will encounter a patient with DM in the operating room on a daily basis. Despite an abundance of published glucose lowering protocols and the known negative outcomes associated with perioperative hyperglycaemia in DM, there is no evidence regarding the optimal intraoperative glucose lowering treatment. In addition, protocol adherence is usually low and protocol targets are not simply met. Recently, incretins have been introduced to lower blood glucose. The main hormone of the incretin system is glucagon-like peptide-1 (GLP-1). GLP-1 increases insulin and decreases glucagon secretion in a glucose-dependent manner, resulting in glucose lowering action with a low incidence of hypoglycaemia. We set out to determine the optimal intraoperative treatment algorithm to lower glucose in patients with DM type 2 undergoing non-cardiac surgery, comparing intraoperative glucose-insulin-potassium infusion (GIK), insulin bolus regimen (BR) and GPL-1 (liragludite, LG) treatment.. This is a multicentre randomised open label trial in patients with DM type 2 undergoing non-cardiac surgery. Patients are randomly assigned to one of three study arms; intraoperative glucose-insulin-potassium infusion (GIK), intraoperative sliding-scale insulin boluses (BR) or GPL-1 pre-treatment with liraglutide (LG). Capillary glucose will be measured every hour. If necessary, in all study arms glucose will be adjusted with an intravenous bolus of insulin. Researchers, care givers and patients will not be blinded for the assigned treatment. The main outcome measure is the difference in median glucose between the three study arms at 1 hour postoperatively. We will include 315 patients, which gives us a 90% power to detect a 1 mmol l(-1) difference in glucose between the study arms.. The PILGRIM trial started in January 2014 and will provide relevant information on the perioperative use of GLP-1 agonists and the optimal intraoperative treatment algorithm in patients with diabetes mellitus type 2.. ClinicalTrials.gov, NCT02036372. Topics: Algorithms; Blood Glucose; Diabetes Mellitus, Type 2; Glucagon-Like Peptide 1; Glucose; Humans; Hypoglycemic Agents; Infusions, Intravenous; Insulin; Liraglutide; Perioperative Care; Postoperative Complications; Potassium; Research Design; Surgical Procedures, Operative | 2014 |
Very short-term effects of the dipeptidyl peptidase-4 inhibitor sitagliptin on the secretion of insulin, glucagon, and incretin hormones in Japanese patients with type 2 diabetes mellitus: analysis of meal tolerance test data.
Sitagliptin inhibits dipeptidyl peptidase-4, which inactivates the incretin hormones glucagon-like peptide-1 (GLP-1) and glucose-dependent insulinotropic polypeptide. To assess its antidiabetic potency, we used meal tolerance tests (MTTs) to determine the very short-term effects of sitagliptin on plasma concentrations of insulin and glucagon.. On day 1, patients with newly diagnosed or uncontrolled type 2 diabetes mellitus started a calorie-restricted diet. On day 2, the first MTT was performed, before treatment with sitagliptin 50 mg/day started later the same day. On day 5, a second MTT was performed. Area under the concentration-time curves (AUCs) of relevant laboratory values were calculated [AUC from time zero to 2 h (AUC0-2h) and from time zero to 4 h (AUC0-4h)].. Fifteen patients were enrolled. AUCs for postprandial plasma glucose were decreased after 3 days of sitagliptin treatment [AUC0-2h 457 ± 115 mg/dL·h (25.4 ± 6.4 mmol/L·h) to 369 ± 108 mg/dL·h (20.5 ± 6.0 mmol/L·h); AUC0-4h 896 ± 248 mg/dL·h (49.7 ± 13.8 mmol/L·h) to 701 ± 246 mg/dL·h (38.9 ± 13.7 mmol/L·h); both p < 0.001]. AUC0-2h and AUC0-4h for postprandial plasma glucagon also decreased: 195 ± 57 to 180 ± 57 pg/mL·h (p < 0.05) and 376 ± 105 to 349 ± 105 pg/mL·h (p < 0.01), respectively. The AUC0-2h [median with quartile values (25%, 75%)] for active GLP-1 increased: 10.5 (8.5, 15.2) to 26.4 (16.7, 32.4) pmol/L·h (p = 0.03).. Very short-term (3-day) treatment with sitagliptin decreases postprandial plasma glucose significantly. This early reduction in glucose may result partly from suppression of excessive glucagon secretion, through a direct effect on active GLP-1. Improvement in postprandial plasma glucose, through suppression of glucagon secretion, is believed to be an advantage of sitagliptin for the treatment of patients with type 2 diabetes. Topics: Aged; Blood Glucose; Diabetes Mellitus, Type 2; Dipeptidyl-Peptidase IV Inhibitors; Female; Food; Glucagon; Glucagon-Like Peptide 1; Humans; Incretins; Insulin; Insulin Secretion; Male; Middle Aged; Postprandial Period; Sitagliptin Phosphate | 2014 |
Evaluation of exenatide versus insulin glargine for the impact on endothelial functions and cardiovascular risk markers.
To demonstrate the efficacy of exenatide versus insulin glargine on endothelial functions and cardiovascular risk markers.. Thirty-four insulin and incretin-naive patients with type 2 diabetes mellitus (body mass index 25-45 kg/m(2)) who received metformin for at least two months were randomized to exenatide or insulin glargine treatment arms and followed-up for 26 weeks. Measurements of endothelial functions were done by ultrasonography, cardiovascular risk markers by serum enzyme-linked immunosorbent assay, and total body fat mass by bioimpedance.. Levels of high sensitivity-C-reactive protein and endothelin-1 decreased (27.5% and 18.75%, respectively) in the exenatide arm. However, in the insulin glargine arm, fibrinogen, monocyte chemoattractant protein-1, leptin and endothelin-1 levels (13.4, 30.2, 47.5, and 80%, respectively) increased. Post-treatment flow mediated dilatation and endothelium independent vascular responses were significantly higher in both arms (p=0.0001, p=0.0001). Positive correlation was observed between the changes in body weight and endothelium-independent vasodilatation, leptin, plasminogen activator inhibitor type 1 and endothelin-1 in both arms (r=0.376, r=0.507, r=0.490, r=0.362, respectively).. Insulin glargine improved endothelial functions, without leading to positive changes in cardiovascular risk markers. Exenatide treatment of 26 weeks resulted in reduced body weight and improvement in certain cardiovascular risk markers and endothelial functions. Topics: Biomarkers; Blood Glucose; Brachial Artery; Cardiovascular Diseases; Diabetes Mellitus, Type 2; Endothelin-1; Endothelium, Vascular; Enzyme-Linked Immunosorbent Assay; Exenatide; Female; Follow-Up Studies; Glucagon-Like Peptide 1; Glycated Hemoglobin; Humans; Hypoglycemic Agents; Insulin Glargine; Insulin, Long-Acting; Male; Middle Aged; Peptides; Prognosis; Risk Factors; Ultrasonography; Vasodilation; Venoms | 2014 |
Effects of LX4211, a dual SGLT1/SGLT2 inhibitor, plus sitagliptin on postprandial active GLP-1 and glycemic control in type 2 diabetes.
Combination therapy is required to provide adequate glycemic control in many patients with type 2 diabetes mellitus (T2DM). Because sodium-dependent glucose transporter (SGLT)-1 inhibition results in an increased release of glucagon-like peptide (GLP)-1, and because dipeptidyl peptidase (DPP)-4 inhibitors prevent its inactivation, the 2 mechanisms together provide an intriguing potential combination therapy.. This combination was explored in preclinical models and then tested in patients with T2DM to compare the effects of single-dose LX4211 400 mg and sitagliptin 100 mg, administered as monotherapy or in combination, on GLP-1, peptide tyrosine tyrosine (PYY), gastric inhibitory peptide (GIP), glucose, and insulin.. Preclinical: Obese male C57BL6J mice were assigned to 1 of 4 treatment groups: LX4211 60 mg/kg, sitagliptin 30 mg/kg, LX4211 + sitagliptin, or inactive vehicle. Clinical: This 3-treatment, 3-crossover, randomized, open-label study was conducted at a single center. Patients on metformin monotherapy were washed out from metformin and were randomly assigned to receive sequences of single-dose LX4211, sitagliptin, or the combination. In both studies, blood was collected for the analysis of pharmacodynamic variables (GLP-1, PYY, GIP, glucose, and insulin). In the clinical study, urine was collected to assess urinary glucose excretion.. Preclinical: 120 mice were treated and assessed (5/time point/treatment group). With repeat daily dosing, the combination was associated with apparently synergistic increases in active GLP-1 relative to monotherapy with either agent; this finding was supported by findings from an additional 14-day repeated-dose experiment. Clinical: 18 patients were enrolled and treated (mean age, 49 years; 56% male; 89% white). The LX4211 + sitagliptin combination was associated with significantly increased active GLP-1, total GLP-1, and total PYY; with a significant reduction in total GIP; and with a significantly improved blood glucose level, with less insulin, compared with sitagliptin monotherapy. LX4211 was associated with a significant increase in total GLP-1 and PYY and a reduced total GIP, likely due to a reduction in SGLT1-mediated intestinal glucose absorption, whereas sitagliptin was associated with suppression of all 3 peptides relative to baseline. All treatments were well tolerated, with no evidence of diarrhea with LX4211 treatment.. The findings from the preclinical studies suggest that the LX4211 + sitagliptin combination produced synergistic increases in active GLP-1 after a meal challenge containing glucose. These initial clinical results also suggest that a LX4211 + DPP-4 inhibitor combination may provide an option in patients with T2DM. The potential long-term clinical benefits of such combination treatment need to be confirmed in large clinical trials. ClinicalTrials.gov identifier: NCT01441232. Topics: Animals; Blood Glucose; Cross-Over Studies; Diabetes Mellitus, Type 2; Enzyme-Linked Immunosorbent Assay; Glucagon-Like Peptide 1; Glycosides; Humans; Hypoglycemic Agents; Mice; Postprandial Period; Pyrazines; Sitagliptin Phosphate; Sodium-Glucose Transporter 1; Sodium-Glucose Transporter 2; Sodium-Glucose Transporter 2 Inhibitors; Triazoles | 2013 |
Metabolic effects of bariatric surgery in patients with moderate obesity and type 2 diabetes: analysis of a randomized control trial comparing surgery with intensive medical treatment.
To evaluate the effects of two bariatric procedures versus intensive medical therapy (IMT) on β-cell function and body composition.. This was a prospective, randomized, controlled trial of 60 subjects with uncontrolled type 2 diabetes (HbA1c 9.7 ± 1%) and moderate obesity (BMI 36 ± 2 kg/m(2)) randomized to IMT alone, IMT plus Roux-en-Y gastric bypass, or IMT plus sleeve gastrectomy. Assessment of β-cell function (mixed-meal tolerance testing) and body composition was performed at baseline and 12 and 24 months.. Glycemic control improved in all three groups at 24 months (N = 54), with a mean HbA1c of 6.7 ± 1.2% for gastric bypass, 7.1 ± 0.8% for sleeve gastrectomy, and 8.4 ± 2.3% for IMT (P < 0.05 for each surgical group versus IMT). Reduction in body fat was similar for both surgery groups, with greater absolute reduction in truncal fat in gastric bypass versus sleeve gastrectomy (-16 vs. -10%; P = 0.04). Insulin sensitivity increased significantly from baseline in gastric bypass (2.7-fold; P = 0.004) and did not change in sleeve gastrectomy or IMT. β-Cell function (oral disposition index) increased 5.8-fold in gastric bypass from baseline, was markedly greater than IMT (P = 0.001), and was not different between sleeve gastrectomy versus IMT (P = 0.30). At 24 months, β-cell function inversely correlated with truncal fat and prandial free fatty acid levels.. Bariatric surgery provides durable glycemic control compared with intensive medical therapy at 2 years. Despite similar weight loss as sleeve gastrectomy, gastric bypass uniquely restores pancreatic β-cell function and reduces truncal fat, thus reversing the core defects in diabetes. Topics: Bariatric Surgery; Blood Glucose; Diabetes Mellitus, Type 2; Gastrectomy; Gastric Bypass; Glucagon-Like Peptide 1; Humans; Insulin Resistance; Insulin-Secreting Cells; Lipid Metabolism; Obesity; Weight Loss | 2013 |
A randomised trial of enteric-coated nutrient pellets to stimulate gastrointestinal peptide release and lower glycaemia in type 2 diabetes.
Glucagon-like peptide-1 (GLP-1), an important mediator of postprandial glycaemia, could potentially be stimulated by delivering small quantities of nutrient to a long length of distal gut. We aimed to determine whether enteric-coated pellets, releasing small amounts of lauric acid throughout the ileum and colon, could reduce glycaemic responses to meals in type 2 diabetes, associated with stimulation of GLP-1.. Eligible patients, who had type 2 diabetes controlled by diet or metformin, were each studied on two occasions in a hospital setting. After an overnight fast, patients consumed 5 g active pellets (47% lauric acid by weight) or placebo with breakfast (T = 0 min) and lunch (T = 240 min), in a crossover design with order randomised by the hospital pharmacy and allocation concealed by numbered containers. Patients and investigators making measurements were blinded to the intervention. Blood was sampled frequently for blood glucose (the primary outcome) and hormone assays.. Eight patients were randomised (four to receive either intervention first), and all completed the study without adverse effects. Blood glucose was lower after breakfast (T = 0-240 min, area under the curve (AUC) 2,075 ± 368 vs 2,216 ± 163 mmol/l × min) and lunch (T = 240-480 min, AUC 1,916 ± 115 vs 2,088 ± 151 mmol/l × min) (p = 0.02 for each) after active pellets than after placebo. Plasma GLP-1 concentrations were higher after breakfast (p = 0.08) and lunch (p = 0.04) for active pellets. While there were no differences in insulin or glucose-dependent insulinotropic polypeptide concentrations, glucagon concentrations were higher after breakfast and lunch (p = 0.002 for each) for active pellets.. Delivering small amounts of nutrient to the ileum and colon can stimulate substantial endogenous GLP-1 release and attenuate postprandial glycaemia. This novel approach has therapeutic potential in type 2 diabetes.. Australian New Zealand Clinical Trials Registry ACTRN12612000600842.. The study was funded by Meyer Nutriceuticals. Topics: Area Under Curve; Blood Glucose; Colon; Cross-Over Studies; Diabetes Mellitus, Type 2; Female; Glucagon; Glucagon-Like Peptide 1; Humans; Hyperglycemia; Ileum; Insulin; Lauric Acids; Male; Metformin; Middle Aged; Tablets, Enteric-Coated; Time Factors | 2013 |
Consumption of buckwheat modulates the post-prandial response of selected gastrointestinal satiety hormones in individuals with type 2 diabetes mellitus.
In healthy participants and those with diet-controlled type 2 diabetes (T2DM), to (1) compare the acute 3-hour post-prandial response of glucose, insulin and other gastrointestinal hormones known to influence food intake and glucose metabolism after consumption of a food product made from whole grain buckwheat flour versus rice flour; (2) determine the effect of daily consumption of a food product made from whole grain buckwheat flour on fasting glucose, lipids and apolipoproteins.. Healthy participants or those with T2DM consumed either buckwheat or rice crackers. Blood samples were collected at baseline and 15, 30, 45, 60, 120 and 180minutes after consumption. In a second phase of the study, participants consumed one serving of buckwheat crackers daily for 1week; fasting blood samples from day 1 and day 7 were analyzed.. Post-prandial plasma glucagon-like peptide-1, glucose-dependent insulinotropic peptide and pancreatic polypeptide were altered after consuming buckwheat versus rice crackers. Interestingly, changes in these hormones did not lead to changes in post-prandial glucose, insulin or C-peptide concentrations. Significant correlations were observed between both fasting concentrations and post-prandial responses of several of the hormones examined. Interestingly, certain correlations were present only in the healthy participant group or the T2DM group. There was no effect of consuming buckwheat for one week on fasting glucose, lipids or apolipoproteins in either the healthy participants or those with T2DM.. Although the buckwheat cracker did not modify acute glycemia or insulinemia, it was sufficient to modulate gastrointestinal satiety hormones. Topics: Aged; Body Mass Index; Canada; Cross-Over Studies; Diabetes Mellitus, Type 2; Dietary Fiber; Fagopyrum; Female; Gastric Inhibitory Polypeptide; Gastrointestinal Tract; Glucagon-Like Peptide 1; Humans; Male; Middle Aged; Oryza; Overweight; Postprandial Period; Satiety Response; Seeds; Single-Blind Method | 2013 |
Acute peripheral administration of synthetic human GLP-1 (7-36 amide) decreases circulating IL-6 in obese patients with type 2 diabetes mellitus: a potential role for GLP-1 in modulation of the diabetic pro-inflammatory state?
To explore the effects of acute administration of GLP-1 and GIP on circulating levels of key adipocyte-derived hormones and gut-brain peptides with established roles in energy and appetite regulation, modulation of insulin sensitivity and inflammation.. Six obese male patients with diet-treated type 2 diabetes (T2DM) and 6 healthy lean subjects were studied. The protocol included 4 experiments for each participant that were carried out in randomised order and comprised: GLP-1 infusion at a rate of 1 pmol/kg/min for 4h, GIP at a rate of 2 pmol/kg/min, GLP-1+GIP and placebo infusion. Plasma leptin, adiponectin, IL-6, insulin, ghrelin and obestatin were measured at baseline, 15, 60, 120, 180 and 240 min following the start of infusion.. Patients with T2DM had higher baseline IL-6 compared with healthy [day of placebo infusion: T2DM IL-6 mean (SEM) 1.3 (0.3) pg/ml vs 0.3 (0.1)pg/ml, p=0.003]. GLP-1 infusion in T2DM was associated with a significant reduction in circulating IL-6 [baseline IL-6 1.2 pg/ml vs IL-6=0.7 at 120 min, p=0.0001; vs IL-6=0.8 at 180 min, p=0.001]. There was no significant change in leptin, adiponectin, ghrelin or obestatin compared to baseline on all 4 experimental days in both groups.. Short-term infusion of supraphysiological concentrations of GLP-1 in T2DM results in suppression of IL-6, a key inflammatory mediator strongly linked to development of obesity and T2DM-related insulin resistance. It remains to be confirmed whether GLP-1-based diabetes therapies can impact favourably on cardiovascular outcomes. Topics: Adult; Diabetes Mellitus, Type 2; Glucagon-Like Peptide 1; Humans; Inflammation; Interleukin-6; Male; Middle Aged; Obesity; Peptide Fragments | 2013 |
The once-daily human GLP-1 analogue liraglutide impacts appetite and energy intake in patients with type 2 diabetes after short-term treatment.
The aim was to investigate effects of liraglutide on appetite and energy intake in a randomized, placebo-controlled, double-blind, crossover study. Eighteen subjects with type 2 diabetes were assigned to treatment with once-daily subcutaneous liraglutide (increasing by weekly 0.6 mg increments) or placebo for 3 weeks. Appetite ratings were assessed using visual analogue scales during a 5-h meal test. Energy and macronutrient intake during the subsequent ad libitum lunch were also measured. After 3 weeks, mean postprandial and minimum hunger ratings were significantly lower with liraglutide 1.8 mg than placebo (p < 0.01), and the mean overall appetite score was significantly higher (p = 0.05), indicating reduced appetite. Liraglutide was associated with higher maximum fullness ratings (p = 0.001) and lower minimum ratings of prospective food consumption (p = 0.01). Mean estimated energy intake was 18% lower for liraglutide than placebo [estimated ratio 0.82 (95% CI 0.73;0.94); p = 0.004], but no significant differences in macronutrient distribution were noted. Findings suggest that reduced appetite and energy intake may contribute to liraglutide-induced weight loss. Topics: Appetite; Blood Glucose; Cross-Over Studies; Diabetes Mellitus, Type 2; Double-Blind Method; Drug Administration Schedule; Energy Intake; Female; Glucagon-Like Peptide 1; Humans; Hypoglycemic Agents; Liraglutide; Male; Postprandial Period; Weight Loss | 2013 |
Effects of intraduodenal glutamine on incretin hormone and insulin release, the glycemic response to an intraduodenal glucose infusion, and antropyloroduodenal motility in health and type 2 diabetes.
Glutamine reduces postprandial glycemia when given before oral glucose. We evaluated whether this is mediated by stimulation of insulin and/or slowing of gastric emptying.. Ten healthy subjects were studied during intraduodenal (ID) infusion of glutamine (7.5 or 15 g) or saline over 30 min, followed by glucose (75 g over 100 min), while recording antropyloroduodenal pressures. Ten patients with type 2 diabetes mellitus (T2DM) were also studied with 15 g glutamine or saline.. ID glutamine stimulated glucagon-like peptide 1 (GLP-1; healthy: P < 0.05; T2DM: P < 0.05), glucose-dependent insulinotropic polypeptide (GIP; P = 0.098; P < 0.05), glucagon (P < 0.01; P < 0.001), insulin (P = 0.05; P < 0.01), and phasic pyloric pressures (P < 0.05; P < 0.05), but did not lower blood glucose (P = 0.077; P = 0.5).. Glutamine does not lower glycemia after ID glucose, despite stimulating GLP-1, GIP, and insulin, probably due to increased glucagon. Its capacity for pyloric stimulation suggests that delayed gastric emptying is a major mechanism for lowering glycemia when glutamine is given before oral glucose. Topics: Adult; Aged; Blood Glucose; Diabetes Mellitus, Type 2; Duodenum; Female; Gastric Emptying; Gastric Inhibitory Polypeptide; Glucagon; Glucagon-Like Peptide 1; Glucose; Glutamine; Healthy Volunteers; Humans; Incretins; Insulin; Insulin Secretion; Male | 2013 |
Mechanisms of glucose lowering of dipeptidyl peptidase-4 inhibitor sitagliptin when used alone or with metformin in type 2 diabetes: a double-tracer study.
To assess glucose-lowering mechanisms of sitagliptin (S), metformin (M), and the two combined (M+S).. We randomized 16 patients with type 2 diabetes mellitus (T2DM) to four 6-week treatments with placebo (P), M, S, and M+S. After each period, subjects received a 6-h meal tolerance test (MTT) with [(14)C]glucose to calculate glucose kinetics. Fasting plasma glucose (FPG), fasting plasma insulin, C-peptide (insulin secretory rate [ISR]), fasting plasma glucagon, and bioactive glucagon-like peptide (GLP-1) and gastrointestinal insulinotropic peptide (GIP) were measured.. FPG decreased from P, 160 ± 4 to M, 150 ± 4; S, 154 ± 4; and M+S, 125 ± 3 mg/dL. Mean post-MTT plasma glucose decreased from P, 207 ± 5 to M, 191 ± 4; S, 195 ± 4; and M+S, 161 ± 3 mg/dL (P < 0.01). The increase in mean post-MTT plasma insulin and in ISR was similar in P, M, and S and slightly greater in M+S. Fasting plasma glucagon was equal (≈ 65-75 pg/mL) with all treatments, but there was a significant drop during the initial 120 min with S 24% and M+S 34% (both P < 0.05) vs. P 17% and M 16%. Fasting and mean post-MTT plasma bioactive GLP-1 were higher (P < 0.01) after S and M+S vs. M and P. Basal endogenous glucose production (EGP) fell from P 2.0 ± 0.1 to S 1.8 ± 0.1 mg/kg · min, M 1.8 ± 0.2 mg/kg · min (both P < 0.05 vs. P), and M+S 1.5 ± 0.1 mg/kg · min (P < 0.01 vs. P). Although the EGP slope of decline was faster in M and M+S vs. S, all had comparable greater post-MTT EGP inhibition vs. P (P < 0.05).. M+S combined produce additive effects to 1) reduce FPG and postmeal plasma glucose, 2) augment GLP-1 secretion and β-cell function, 3) decrease plasma glucagon, and 4) inhibit fasting and postmeal EGP compared with M or S monotherapy. Topics: Blood Glucose; C-Peptide; Diabetes Mellitus, Type 2; Dipeptidyl-Peptidase IV Inhibitors; Fasting; Gastric Inhibitory Polypeptide; Glucagon-Like Peptide 1; Humans; Hypoglycemic Agents; Insulin; Metformin; Pyrazines; Sitagliptin Phosphate; Triazoles | 2013 |
Efficacy and safety over 26 weeks of an oral treatment strategy including sitagliptin compared with an injectable treatment strategy with liraglutide in patients with type 2 diabetes mellitus inadequately controlled on metformin: a randomised clinical tri
The aim of this work was to compare treatment intensification strategies based on orally administered vs injectable incretin-based antihyperglycaemic agents in patients with type 2 diabetes mellitus on metformin monotherapy.. In a 26 week, open-label study, 653 patients (baseline HbA1c = 8.2% [66 mmol/mol]) were randomised at 111 sites in 21 countries in a 1:1 ratio to a strategy using oral agents (starting with sitagliptin 100 mg/day) or a strategy using the injectable drug liraglutide starting at a dose of 0.6 mg/day, up-titrated to 1.2 mg/day after 1 week. The following patients with type 2 diabetes mellitus were recruited for the study: those aged 18-79 years, on a stable dose of metformin monotherapy ≥1,500 mg/day for ≥12 weeks, with an HbA1c ≥7.0% (53 mmol/mol) and ≤11.0% (97 mmol/mol) and a fasting fingerstick glucose (FFG) <15 mmol/l (<270 mg/dl) at the randomisation visit, deemed capable by the investigator of using a Victoza pen injection device (containing 6 mg/ml liraglutide; Novo Nordisk, Bagsværd, Denmark). Women taking part in the study agreed to remain abstinent or use an acceptable method of birth control during the study. Randomisation was performed via a computer-generated allocation schedule using an interactive voice response system. After 12 weeks, patients on sitagliptin with HbA1c ≥ 7.0% (53 mmol/mol) and fasting glucose >6.1 mmol/l had their treatment intensified with glimepiride; patients on liraglutide with HbA1c ≥ 7.0% (53 mmol/mol) had the dose up-titrated to 1.8 mg/day. The primary analysis assessed whether the strategy using oral drugs was non-inferior to that using an injectable drug regarding HbA1c change from baseline at week 26 using a per-protocol (PP) population and a non-inferiority margin of 0.4%.. In the PP population (522 patients included: oral strategy, n = 269; injectable strategy, n = 253) antihyperglycaemic therapy was intensified at week 12 in 50.2% and 28.5%, respectively. HbA1c decreased over 26 weeks in both treatment strategy groups, with a larger initial reduction at week 12 in the injectable strategy group. The LS mean change in HbA1c at week 26 was -1.3% (95% CI -1.4, -1.2) in the oral strategy group and -1.4% (95% CI -1.5, -1.3) in the injectable strategy group; the study met the non-inferiority criterion. Both treatment regimens were generally well tolerated; hypoglycaemia was reported more often with the oral strategy, while nausea, vomiting, diarrhoea and abdominal pain were reported more often with the injectable strategy.. An oral, incretin-based treatment strategy with sitagliptin and, if needed, glimepiride may be a good approach in many patients with type 2 diabetes mellitus for managing inadequate glycaemic control on metformin monotherapy, as compared with an injectable treatment strategy with liraglutide. The oral and injectable strategies had similar effects on HbA1c and had good overall tolerability. Trial registration ClinicalTrials.gov NCT01296412 Funding The study was sponsored by Merck Sharp & Dohme Corp., a subsidiary of Merck and Co., Inc., Whitehouse Station, NJ, USA. Topics: Adolescent; Adult; Aged; Diabetes Mellitus, Type 2; Female; Glucagon-Like Peptide 1; Glycated Hemoglobin; Humans; Hypoglycemic Agents; Liraglutide; Male; Metformin; Middle Aged; Pyrazines; Sitagliptin Phosphate; Sulfonylurea Compounds; Treatment Outcome; Triazoles; Young Adult | 2013 |
Effect of vildagliptin on glucose and insulin concentrations during a 24-hour period in type 2 diabetes patients with different ranges of baseline hemoglobin A1c levels.
Currently, it is still unknown whether differences in glycemic control have any effect on glucose and insulin kinetics after vildagliptin administration. The aim of this study was to evaluate the effect of vildagliptin on glucose and insulin concentrations during a 24-h period in type 2 diabetes patients with different ranges of baseline hemoglobin A1c (A1C) levels.. A randomized, double-blind, crossover, placebo-controlled clinical trial was carried out in 12 drug-naive adult volunteers with type 2 diabetes and overweight or obesity. Subjects had fasting glucose values between 7.2 and 13.3 mmol/L. Six patients had A1C between 7.0% and 8.4% (Group A), and the remaining subjects had A1C between 8.5% and 10.0% (Group B). Patients received oral administration of vildagliptin (50 mg twice daily) or placebo in a crossover manner for two consecutive days. Until the second day of the interventions, glucose and insulin concentrations were measured every hour during a 24-h period, and areas under the curve (AUCs) were calculated. Statistical analyses were evaluated with Wilcoxon and Mann-Whitney U tests.. There were significant decreases in glucose concentrations after vildagliptin administration in both groups when comparing placebo in all measurements throughout the 24-h period and in the AUC. There were no significant changes in insulin concentration in both groups after vildagliptin administration when comparing placebo in all measurements throughout the 24-h period and in the AUC.. Vildagliptin administration improved glucose control during a 24-h period in type 2 diabetes patients, independent of the basal A1C level, without changes in insulin levels. Topics: Adamantane; Adult; Blood Glucose; Body Mass Index; Cross-Over Studies; Diabetes Mellitus, Type 2; Dipeptidyl-Peptidase IV Inhibitors; Double-Blind Method; Female; Glucagon-Like Peptide 1; Glycated Hemoglobin; Humans; Hyperglycemia; Insulin; Insulin Secretion; Insulin-Secreting Cells; Kinetics; Male; Middle Aged; Nitriles; Obesity; Overweight; Pyrrolidines; Vildagliptin | 2013 |
Effects of ingestion routes on hormonal and metabolic profiles in gastric-bypassed humans.
Gastric bypass surgery (GBP) results in the rapid resolution of type 2 diabetes. Most studies aiming to explain the underlying mechanisms are limited to data obtained after a postsurgical recovery period, making assessment of confounding influences from, for example, weight loss and altered nutrient intake difficult.. To examine the impact of GBP on hormonal and metabolite profiles under conditions of identical nutrient intake independent of weight loss, we studied GBP patients fitted with a gastrostomy tube to enable the administration of nutrients to bypassed segments of the gut. Thus, this model allowed us to simulate partially the preoperative condition and compare this with the postoperative situation in the same patient.. Patients (n = 4) were first given a mixed meal test (MMT) orally and then via the gastrostomy tube, preceded by overnight and 2-hour fasting, respectively. Blood samples were assessed for hormones and metabolites.. The oral MMT yielded 4.6-fold increase in plasma insulin (P < .05), 2-fold in glucagon-like peptide-1 (P < .05), and 2.5-fold in glucose-dependent insulinotropic peptide (P < .05) plasma levels, compared with the gastrostomy MMT. The changes in hormone levels were accompanied by elevated branched-chain amino acid levels (1.4-2-fold, P < .05) and suppressed fatty acid levels (∼50%, P < .05).. These data, comparing identical nutrient delivery, demonstrate markedly higher incretin and insulin responses after oral MMT than after gastric MMT, thereby providing a potential explanation for the rapid remission of type 2 diabetes observed after GBP. The simultaneous increase in branched-chain amino acid questions its role as a marker for insulin resistance. Topics: Adult; Amino Acids, Branched-Chain; Biomarkers; Body Mass Index; Diabetes Mellitus, Type 2; Fatty Acids, Nonesterified; Female; Gastric Bypass; Gastric Inhibitory Polypeptide; Gastrostomy; Glucagon-Like Peptide 1; Humans; Insulin; Insulin Resistance; Meals; Obesity, Morbid; Postoperative Period; Postprandial Period | 2013 |
The CTRB1/2 locus affects diabetes susceptibility and treatment via the incretin pathway.
The incretin hormone glucagon-like peptide 1 (GLP-1) promotes glucose homeostasis and enhances β-cell function. GLP-1 receptor agonists (GLP-1 RAs) and dipeptidyl peptidase-4 (DPP-4) inhibitors, which inhibit the physiological inactivation of endogenous GLP-1, are used for the treatment of type 2 diabetes. Using the Metabochip, we identified three novel genetic loci with large effects (30-40%) on GLP-1-stimulated insulin secretion during hyperglycemic clamps in nondiabetic Caucasian individuals (TMEM114; CHST3 and CTRB1/2; n = 232; all P ≤ 8.8 × 10(-7)). rs7202877 near CTRB1/2, a known diabetes risk locus, also associated with an absolute 0.51 ± 0.16% (5.6 ± 1.7 mmol/mol) lower A1C response to DPP-4 inhibitor treatment in G-allele carriers, but there was no effect on GLP-1 RA treatment in type 2 diabetic patients (n = 527). Furthermore, in pancreatic tissue, we show that rs7202877 acts as expression quantitative trait locus for CTRB1 and CTRB2, encoding chymotrypsinogen, and increases fecal chymotrypsin activity in healthy carriers. Chymotrypsin is one of the most abundant digestive enzymes in the gut where it cleaves food proteins into smaller peptide fragments. Our data identify chymotrypsin in the regulation of the incretin pathway, development of diabetes, and response to DPP-4 inhibitor treatment. Topics: Adult; Aged; Chymotrypsin; Diabetes Mellitus; Diabetes Mellitus, Type 2; Dipeptidyl-Peptidase IV Inhibitors; Female; Genotype; Glucagon-Like Peptide 1; Glucagon-Like Peptide-1 Receptor; Humans; Hypoglycemic Agents; Incretins; Insulin; Male; Middle Aged; Receptors, Glucagon; Signal Transduction | 2013 |
Effects of liraglutide, a human glucagon-like peptide-1 analogue, on body weight, body fat area and body fat-related markers in patients with type 2 diabetes mellitus.
To evaluate the effects of six-month liraglutide treatment on body weight, visceral and subcutaneous fat and related markers in Japanese type 2 diabetic patients.. A total of 59 patients with type 2 diabetes were treated with liraglutide (0.3 mg/day for ≥1 week and then 0.6 mg/day for ≥1 week, gradually increasing the dose to 0.9 mg/day) for six months. Changes in body weight, body mass index (BMI), HbA1c, the fasting blood glucose level, visceral and subcutaneous fat areas, hepatic and renal CT values and the associated markers proinsulin, adiponectin and pentraxin (PTX) 3 were measured.. The study included one treatment-naïve patient, 10 patients who were switched from oral antidiabetic drugs and 35 patients who were switched from insulin therapy. At six months after treatment, the preprandial blood glucose levels were higher (148.8±40.5 mg/dL) than the baseline values (130.8±36.7, p<0.05); however, body weight, BMI and abdominal circumference were lower, and the liver/kidney CT ratio improved significantly from 1.64±0.44 at baseline to 1.78±0.42. An analysis of the patients who were not pretreated with insulin resistance ameliorators showed that six months of liraglutide treatment significantly decreased the subcutaneous but not visceral fat areas, significantly decreased the serum adiponectin levels and significantly increased the serum PTX3 levels.. In addition to its glucose-lowering effects, liraglutide exhibits weight loss promotion actions, reducing subcutaneous fat areas in particular. The weight and total fat area reduction properties of liraglutide are likely to be beneficial when this medication is used in combination with other oral antidiabetic drugs and insulin. Topics: Adiponectin; Adiposity; Aged; Anthropometry; Asian People; Blood Glucose; Body Mass Index; Body Weight; C-Reactive Protein; Diabetes Mellitus, Type 2; Fasting; Fatty Liver; Female; Glucagon-Like Peptide 1; Glycated Hemoglobin; Humans; Hypoglycemic Agents; Intra-Abdominal Fat; Japan; Kidney; Liraglutide; Liver; Male; Middle Aged; Non-alcoholic Fatty Liver Disease; Proinsulin; Serum Amyloid P-Component; Subcutaneous Fat; Tomography, X-Ray Computed | 2013 |
Liraglutide suppresses postprandial triglyceride and apolipoprotein B48 elevations after a fat-rich meal in patients with type 2 diabetes: a randomized, double-blind, placebo-controlled, cross-over trial.
Postprandial triglyceridaemia is a risk factor for cardiovascular disease (CVD). This study investigated the effects of steady-state liraglutide 1.8 mg versus placebo on postprandial plasma lipid concentrations after 3 weeks of treatment in patients with type 2 diabetes mellitus (T2DM).. In a cross-over trial, patients with T2DM (n = 20, 18-75 years, BMI 18.5-40 kg/m²) were randomized to once-daily subcutaneous liraglutide (weekly dose escalation from 0.6 to 1.8 mg) and placebo. After each 3-week period, a standardized fat-rich meal was provided, and the effects of liraglutide on triglyceride (primary endpoint AUC(0-8h)), apolipoprotein B48, non-esterified fatty acids, glycaemic responses and gastric emptying were assessed. ClinicalTrials.gov ID: NCT00993304.. Novo Nordisk A/S.. After 3 weeks, mean postprandial triglyceride (AUC(0-8h) liraglutide/placebo treatment-ratio 0.72, 95% CI [0.62-0.83], p = 0.0004) and apolipoprotein B48 (AUC(0-8h) ratio 0.65 [0.58-0.73], p < 0.0001) significantly decreased with liraglutide 1.8 mg versus placebo, as did iAUC(0-8h) and C(max) (p < 0.001). No significant treatment differences were observed for non-esterified fatty acids. Mean postprandial glucose and glucagon AUC(0-8h) and C(max) were significantly reduced with liraglutide versus placebo. Postprandial gastric emptying rate [assessed by paracetamol absorption (liquid phase) and the ¹³C-octanoate breath test (solid phase)] displayed no treatment differences. Mean low-density lipoprotein and total cholesterol decreased significantly with liraglutide versus placebo.. Liraglutide treatment in patients with T2DM significantly reduced postprandial excursions of triglyceride and apolipoprotein B48 after a fat-rich meal, independently of gastric emptying. Results indicate liraglutide's potential to reduce CVD risk via improvement of postprandial lipaemia. Topics: Aged; Body Mass Index; Cardiovascular Diseases; Cross-Over Studies; Denmark; Diabetes Mellitus, Type 2; Diet, High-Fat; Double-Blind Method; Female; Gastric Emptying; Germany; Glucagon-Like Peptide 1; Half-Life; Humans; Hyperlipidemias; Hypoglycemic Agents; Hypolipidemic Agents; Lipids; Liraglutide; Male; Middle Aged; Obesity; Postprandial Period; Risk Factors | 2013 |
Rationale and design of the glycemia reduction approaches in diabetes: a comparative effectiveness study (GRADE).
The epidemic of type 2 diabetes (T2DM) threatens to become the major public health problem of this century. However, a comprehensive comparison of the long-term effects of medications to treat T2DM has not been conducted. GRADE, a pragmatic, unmasked clinical trial, aims to compare commonly used diabetes medications, when combined with metformin, on glycemia-lowering effectiveness and patient-centered outcomes.. GRADE was designed with support from a U34 planning grant from the National Institute of Diabetes and Digestive and Kidney Diseases (NIDDK). The consensus protocol was approved by NIDDK and the GRADE Research Group. Eligibility criteria for the 5,000 metformin-treated subjects include <5 years' diabetes duration, ≥ 30 years of age at time of diagnosis, and baseline hemoglobin A1c (A1C) of 6.8-8.5% (51-69 mmol/mol). Medications representing four classes (sulfonylureas, dipeptidyl peptidase 4 inhibitors, glucagon-like peptide 1 receptor agonists, and insulin) will be randomly assigned and added to metformin (minimum-maximum 1,000-2,000 mg/day). The primary metabolic outcome is the time to primary failure defined as an A1C ≥ 7% (53 mmol/mol), subsequently confirmed, over an anticipated mean observation period of 4.8 years (range 4-7 years). Other long-term metabolic outcomes include the need for the addition of basal insulin after a confirmed A1C >7.5% (58 mmol/mol) and, ultimately, the need to implement an intensive basal/bolus insulin regimen. The four drugs will also be compared with respect to selected microvascular complications, cardiovascular disease risk factors, adverse effects, tolerability, quality of life, and cost-effectiveness.. GRADE will compare the long-term effectiveness of major glycemia-lowering medications and provide guidance to clinicians about the most appropriate medications to treat T2DM. GRADE begins recruitment at 37 centers in the U.S. in 2013. Topics: Adult; Blood Glucose; Comparative Effectiveness Research; Cost-Benefit Analysis; Diabetes Mellitus, Type 2; Dipeptidyl-Peptidase IV Inhibitors; Female; Glucagon-Like Peptide 1; Glycated Hemoglobin; Humans; Hypoglycemic Agents; Insulin Glargine; Insulin, Long-Acting; Liraglutide; Male; Metformin; Middle Aged; Outcome Assessment, Health Care; Pyrazines; Sitagliptin Phosphate; Sulfonylurea Compounds; Triazoles | 2013 |
Independent glucose and weight-reducing effects of Liraglutide in a real-world population of type 2 diabetic outpatients.
The GLP-1 receptor agonist Liraglutide is effective in reducing HbA1c in type 2 diabetic (T2D) patients. In addition, treatment with Liraglutide is associated with significant weight loss. In this study, we analyzed the inter-relationships between glycemic and weight effects of Liraglutide treatment in a population of type 2 diabetic outpatients. T2D patients initiating Liraglutide therapy since September 2010 to July 2012 at 3 outpatient clinics were enrolled and followed-up. We collected baseline information about anthropometric data, cardiovascular risk factors, diabetes duration, prevalence of complications and history of anti-diabetic medications. We collected HbA1c and body weight at baseline and every 4 months. A total of 166 patients were included, who were on average 56.6 ± 8.9 (mean ± SD) years old and had a baseline HbA1c of 8.7 ± 1.3 % and BMI 36.3 ± 6.4 kg/m(2). Mean follow-up was 9.4 ± 4.2 months (range 4-16). Patients lost on average 1.5 ± 1.3 % HbA1c and 4.0 ± 5.0 kg body weight. Most patients (73.5 %) improved HbA1c and loosed weight. Significant independent determinants of HbA1c drop were baseline HbA1c (r = 0.673; p < 0.001) and previous insulin therapy (r = -0.251; p < 0.001). The only independent determinant of weight loss was baseline BMI (r = 0.429; p < 0.001). Drop in HbA1c was unrelated to baseline BMI or weight loss. Weight loss was unrelated to baseline HbA1c or drop in HbA1c. Glycemic improvement and weight reduction obtained with Liraglutide treatment in T2D patients in a real-world setting are independent and possibly mediated by different mechanisms. Topics: Adult; Aged; Blood Glucose; Body Mass Index; Body Weight; Diabetes Mellitus, Type 2; Female; Glucagon-Like Peptide 1; Humans; Hypoglycemic Agents; Liraglutide; Male; Middle Aged; Outpatients; Weight Loss | 2013 |
Impaired cardiometabolic responses to glucagon-like peptide 1 in obesity and type 2 diabetes mellitus.
Glucagon-like peptide 1 (GLP-1) has insulin-like effects on myocardial glucose uptake which may contribute to its beneficial effects in the setting of myocardial ischemia. Whether these effects are different in the setting of obesity or type 2 diabetes (T2DM) requires investigation. We examined the cardiometabolic actions of GLP-1 (7-36) in lean and obese/T2DM humans, and in lean and obese Ossabaw swine. GLP-1 significantly augmented myocardial glucose uptake under resting conditions in lean humans, but this effect was impaired in T2DM. This observation was confirmed and extended in swine, where GLP-1 effects to augment myocardial glucose uptake during exercise were seen in lean but not in obese swine. GLP-1 did not increase myocardial oxygen consumption or blood flow in humans or in swine. Impaired myocardial responsiveness to GLP-1 in obesity was not associated with any apparent alterations in myocardial or coronary GLP1-R expression. No evidence for GLP-1-mediated activation of cAMP/PKA or AMPK signaling in lean or obese hearts was observed. GLP-1 treatment augmented p38-MAPK activity in lean, but not obese cardiac tissue. Taken together, these data provide novel evidence indicating that the cardiometabolic effects of GLP-1 are attenuated in obesity and T2DM, via mechanisms that may involve impaired p38-MAPK signaling. Topics: Adult; Animals; Comorbidity; Diabetes Mellitus, Type 2; Disease Models, Animal; Female; Glucagon-Like Peptide 1; Glucose; Hemodynamics; Humans; Incretins; Male; Middle Aged; Myocardium; Obesity; Oxygen Consumption; p38 Mitogen-Activated Protein Kinases; Physical Conditioning, Animal; Regional Blood Flow; Rest; Signal Transduction; Swine; Treatment Outcome | 2013 |
Pharmacokinetic and pharmacodynamic interaction of vildagliptin and voglibose in Japanese patients with Type 2 diabetes.
To assess the extent of pharmacokinetic and pharmacodynamic interaction between vildagliptin, a potent and selective inhibitor of dipeptidyl peptidase IV (DPP-4) enzyme, and voglibose, an α-glucosidase inhibitor widely prescribed in Japan, when coadministered in Japanese patients with Type 2 diabetes.. In this open-label, randomized, 3-treatment, 3-period and 6-way crossover study, 24 Japanese patients with Type 2 diabetes received 50 mg vildagliptin twice daily; 50 mg vildagliptin twice daily co-administered with 0.2 mg voglibose three times daily; or 0.2 mg voglibose three times daily for 3 days in each period. Plasma concentrations of vildagliptin, DPP-4, glucagon-like peptide-1 (GLP-1), glucose, insulin, and glucagon were determined from blood samples collected at steady state.. Exposure to vildagliptin 50 mg (area under the concentration-time curve from 0 to 12 hours (AUCτ,ss)) and maximum plasma concentration at steady state (Cmax,ss) was reduced by 23% and 34% respectively with co-administration of voglibose. The percentage of DPP-4 inhibition by vildagliptin remained unchanged when vildagliptin was given alone or co-administered with voglibose; maximum inhibition was 98.3 ± 1.4% (mean ± SD) for vildagliptin alone and 97.4 ± 1.1% with co-administration. Coadministration of vildagliptin and voglibose led to a greater increase in the active GLP-1 plasma concentration than did vildagliptin alone (geometric mean ratio 1.63 (90% CI, 1.30, 2.03), p = 0.0007). The combination of vildagliptin and voglibose also led to a significantly lower plasma glucose levels (p < 0.0001).. Plasma vildagliptin levels were decreased when voglibose was co-administered, although DPP- 4 inhibition remained unchanged. Co-administration led to significantly better pharmacodynamic response compared with each treatment alone, including higher active GLP-1 and lower glucose levels. The results indicate that this coadministration may be beneficial in the clinical situation. Vildagliptin and voglibose treatments, alone or when co-administered, were well tolerated in Japanese patients with Type 2 diabetes. Topics: Adamantane; Adult; Blood Glucose; Cross-Over Studies; Diabetes Mellitus, Type 2; Dipeptidyl-Peptidase IV Inhibitors; Drug Interactions; Female; Glucagon; Glucagon-Like Peptide 1; Glycoside Hydrolase Inhibitors; Humans; Hypoglycemic Agents; Inositol; Insulin; Male; Middle Aged; Nitriles; Pyrrolidines; Vildagliptin | 2013 |
Benefits of liraglutide treatment in overweight and obese older individuals with prediabetes.
The aim was to evaluate the ability of liraglutide to augment weight loss and improve insulin resistance, cardiovascular disease (CVD) risk factors, and inflammation in a high-risk population for type 2 diabetes (T2DM) and CVD.. We randomized 68 older individuals (mean age, 58±8 years) with overweight/obesity and prediabetes to this double-blind study of liraglutide 1.8 mg versus placebo for 14 weeks. All subjects were advised to decrease calorie intake by 500 kcal/day. Peripheral insulin resistance was quantified by measuring the steady-state plasma glucose (SSPG) concentration during the insulin suppression test. Traditional CVD risk factors and inflammatory markers also were assessed.. Eleven out of 35 individuals (31%) assigned to liraglutide discontinued the study compared with 6 out of 33 (18%) assigned to placebo (P=0.26). Subjects who continued to use liraglutide (n=24) lost twice as much weight as those using placebo (n=27; 6.8 vs. 3.3 kg; P<0.001). Liraglutide-treated subjects also had a significant improvement in SSPG concentration (-3.2 vs. 0.2 mmol/L; P<0.001) and significantly (P≤0.04) greater lowering of systolic blood pressure (-8.1 vs. -2.6 mmHg), fasting glucose (-0.5 vs. 0 mmol/L), and triglyceride (-0.4 vs. -0.1 mmol/L) concentration. Inflammatory markers did not differ between the two groups, but pulse increased after liraglutide treatment (6.4 vs. -0.9 bpm; P=0.001).. The addition of liraglutide to calorie restriction significantly augmented weight loss and improved insulin resistance, systolic blood pressure, glucose, and triglyceride concentration in this population at high risk for development of T2DM and CVD. Topics: Body Weight; Caloric Restriction; Diabetes Mellitus, Type 2; Double-Blind Method; Female; Glucagon-Like Peptide 1; Humans; Hypoglycemic Agents; Insulin Resistance; Liraglutide; Male; Middle Aged; Obesity; Overweight; Prediabetic State; Triglycerides; Weight Loss | 2013 |
The glucagon-like peptide-1 receptor agonist, liraglutide, attenuates the progression of overt diabetic nephropathy in type 2 diabetic patients.
Diabetic nephropathy (DN) is the leading cause of end-stage renal disease. Glucagon-like peptide-1 (GLP-1) is one of the incretins, gut hormones released from the intestine in response to food intake. GLP-1 receptor (GLP-1R) agonists have been used to treat type 2 diabetes. Here, we studied the effect of the administration of a GLP-1R agonist, liraglutide, on proteinuria and the progression of overt DN in type 2 diabetic patients. Twenty-three type 2 diabetic patients with overt DN, who had already been treated with blockade of renin-angiotensin system under dietary sodium restriction, were given liraglutide for a period of 12 months. Treatment with liraglutide caused a significant decrease in HbA1c from 7.4 ± 0.2% to 6.9 ± 0.3% (p = 0.04), and in body mass index (BMI) from 27.6 ± 0.9 kg/m² to 26.5 ± 0.8 kg/m² after 12 months (p < 0.001), while systolic blood pressure did not change. The progression of DN was determined as the rate of decline in estimated glomerular filtration rate (eGFR). The 12-month administration of liraglutide caused a significant decrease in proteinuria from 2.53 ± 0.48 g/g creatinine to 1.47 ± 0.28 g/g creatinine (p = 0.002). The administration of liraglutide also substantially diminished the rate of decline in eGFR from 6.6 ± 1.5 mL/min/1.73 m²/year to 0.3 ± 1.9 mL/min/1.73 m²/year (p = 0.003). Liraglutide can be used not only for reducing HbA1c and BMI, but also for attenuating the progression of nephropathy in type 2 diabetic patients. Topics: Blood Pressure; Body Mass Index; Diabetes Mellitus, Type 2; Diabetic Nephropathies; Disease Progression; Female; Glomerular Filtration Rate; Glucagon-Like Peptide 1; Glucagon-Like Peptide-1 Receptor; Glycated Hemoglobin; Humans; Liraglutide; Male; Middle Aged; Proteinuria; Receptors, Glucagon; Systole | 2013 |
Unimolecular dual incretins maximize metabolic benefits in rodents, monkeys, and humans.
We report the discovery and translational therapeutic efficacy of a peptide with potent, balanced co-agonism at both of the receptors for the incretin hormones glucagon-like peptide-1 (GLP-1) and glucose-dependent insulinotropic polypeptide (GIP). This unimolecular dual incretin is derived from an intermixed sequence of GLP-1 and GIP, and demonstrated enhanced antihyperglycemic and insulinotropic efficacy relative to selective GLP-1 agonists. Notably, this superior efficacy translated across rodent models of obesity and diabetes, including db/db mice and ZDF rats, to primates (cynomolgus monkeys and humans). Furthermore, this co-agonist exhibited synergism in reducing fat mass in obese rodents, whereas a selective GIP agonist demonstrated negligible weight-lowering efficacy. The unimolecular dual incretins corrected two causal mechanisms of diabesity, adiposity-induced insulin resistance and pancreatic insulin deficiency, more effectively than did selective mono-agonists. The duration of action of the unimolecular dual incretins was refined through site-specific lipidation or PEGylation to support less frequent administration. These peptides provide comparable pharmacology to the native peptides and enhanced efficacy relative to similarly modified selective GLP-1 agonists. The pharmacokinetic enhancement lessened peak drug exposure and, in combination with less dependence on GLP-1-mediated pharmacology, avoided the adverse gastrointestinal effects that typify selective GLP-1-based agonists. This discovery and validation of a balanced and high-potency dual incretin agonist enables a more physiological approach to management of diseases associated with impaired glucose tolerance. Topics: Acylation; Adolescent; Adult; Aged; Animals; Diabetes Mellitus, Type 2; Exenatide; Female; Gastric Inhibitory Polypeptide; Glucagon-Like Peptide 1; Glucagon-Like Peptide-1 Receptor; Glucose Tolerance Test; Haplorhini; Humans; Hyperglycemia; Incretins; Insulin; Liraglutide; Male; Mice; Middle Aged; Peptides; Rats; Receptors, Gastrointestinal Hormone; Receptors, Glucagon; Rodentia; Treatment Outcome; Venoms; Weight Loss; Young Adult | 2013 |
Design of the liraglutide effect and action in diabetes: evaluation of cardiovascular outcome results (LEADER) trial.
Diabetes is a multisystem disorder associated with a nearly twofold excess risk for a broad range of adverse cardiovascular outcomes including coronary heart disease, stroke, and cardiovascular death. Liraglutide is a human glucagon-like peptide receptor analog approved for use in patients with type 2 diabetes mellitus (T2DM).. To formally assess the cardiovascular safety of liraglutide, the Liraglutide Effect and Action in Diabetes: Evaluation of cardiovascular outcome Results (LEADER) trial was commenced in 2010. LEADER is a phase 3B, multicenter, international, randomized, double-blind, placebo-controlled clinical trial with long-term follow-up. Patients with T2DM at high risk for cardiovascular disease (CVD) who were either drug naive or treated with oral antihyperglycemic agents or selected insulin regimens (human NPH, long-acting analog, or premixed) alone or in combination with oral antihyperglycemics were eligible for inclusion. Randomized patients are being followed for up to 5 years. The primary end point is the time from randomization to a composite outcome consisting of the first occurrence of cardiovascular death, nonfatal myocardial infarction, or nonfatal stroke.. LEADER commenced in September 2010, and enrollment concluded in April 2012. There were 9,340 patients enrolled at 410 sites in 32 countries. The mean age of patients was 64.3 ± 7.2 years, 64.3% were men, and mean body mass index was 32.5 ± 6.3 kg/m2. There were 7,592 (81.3%) patients with prior CVD and 1,748 (18.7%) who were high risk but without prior CVD. It is expected that LEADER will provide conclusive data regarding the cardiovascular safety of liraglutide relative to the current standard of usual care for a global population of patients with T2DM. Topics: Aged; Cardiovascular Diseases; Diabetes Mellitus, Type 2; Double-Blind Method; Female; Glucagon-Like Peptide 1; Humans; Hypoglycemic Agents; Liraglutide; Male; Middle Aged; Research Design; Treatment Outcome | 2013 |
Long-term safety and efficacy of empagliflozin, sitagliptin, and metformin: an active-controlled, parallel-group, randomized, 78-week open-label extension study in patients with type 2 diabetes.
To investigate the long-term safety and efficacy of empagliflozin, a sodium glucose cotransporter 2 inhibitor; sitagliptin; and metformin in patients with type 2 diabetes.. In this randomized, open-label, 78-week extension study of two 12-week, blinded, dose-finding studies of empagliflozin (monotherapy and add-on to metformin) with open-label comparators, 272 patients received 10 mg empagliflozin (166 as add-on to metformin), 275 received 25 mg empagliflozin (166 as add-on to metformin), 56 patients received metformin, and 56 patients received sitagliptin as add-on to metformin.. Changes from baseline in HbA1c at week 90 were -0.34 to -0.63% (-3.7 to -6.9 mmol/mol) with empagliflozin, -0.56% (-6.1 mmol/mol) with metformin, and -0.40% (-4.4 mmol/mol) with sitagliptin. Changes from baseline in weight at week 90 were -2.2 to -4.0 kg with empagliflozin, -1.3 kg with metformin, and -0.4 kg with sitagliptin. Adverse events (AEs) were reported in 63.2-74.1% of patients on empagliflozin and 69.6% on metformin or sitagliptin; most AEs were mild or moderate in intensity. Hypoglycemic events were rare in all treatment groups, and none required assistance. AEs consistent with genital infections were reported in 3.0-5.5% of patients on empagliflozin, 1.8% on metformin, and none on sitagliptin. AEs consistent with urinary tract infections were reported in 3.8-12.7% of patients on empagliflozin, 3.6% on metformin, and 12.5% on sitagliptin.. Long-term empagliflozin treatment provided sustained glycemic and weight control and was well tolerated with a low risk of hypoglycemia in patients with type 2 diabetes. Topics: Adolescent; Adult; Aged; Benzhydryl Compounds; Blood Glucose; Diabetes Mellitus, Type 2; Dose-Response Relationship, Drug; Double-Blind Method; Drug Therapy, Combination; Female; Follow-Up Studies; Glucagon-Like Peptide 1; Glucosides; Glycated Hemoglobin; Humans; Hypoglycemic Agents; Male; Metformin; Middle Aged; Pyrazines; Sitagliptin Phosphate; Time Factors; Treatment Outcome; Triazoles | 2013 |
Effects of aerobic exercise with or without metformin on plasma incretins in type 2 diabetes.
Despite positive effects of incretins on insulin secretion, little is known about the effect of exercise on these hormones. Metformin can affect incretin concentrations and is prescribed to a large proportion of people with diabetes. We, therefore, examined the effects of aerobic exercise and/or metformin on incretin hormones.. Ten participants with type 2 diabetes were recruited for this randomized crossover study. Metformin or placebo was given for 28 days, followed by the alternate treatment for 28 days. On the last 2 days of each condition, participants were assessed during a non-exercise day and a subsequent exercise day. Aerobic exercise took place in the morning and blood samples were taken in the subsequent hours (before and after lunch).. Aerobic exercise did not increase total plasma glucagon-like peptide-1 (GLP-1) or glucose-dependent insulinotropic polypeptide (GIP) in the pre- or post-lunch periods (all p>0.1). GLP-1 was higher in the pre-lunch (p=0.016) and post-lunch (p=0.018) periods of the metformin conditions compared with the placebo. Total plasma GIP was higher in the pre-lunch period (p=0.05), but not in the post-lunch period (p=0.95), with metformin compared with placebo.. In contrast to our hypothesis, aerobic exercise did not acutely increase total GLP-1 and GIP levels in patients with type 2 diabetes. Metformin, independent of exercise, significantly increased total plasma GLP-1 and GIP concentrations in these patients. Topics: Combined Modality Therapy; Cross-Over Studies; Diabetes Mellitus, Type 2; Exercise Therapy; Female; Gastric Inhibitory Polypeptide; Glucagon-Like Peptide 1; Humans; Hypoglycemic Agents; Male; Metformin; Middle Aged | 2013 |
Weight change with liraglutide and comparator therapies: an analysis of seven phase 3 trials from the liraglutide diabetes development programme.
We investigated the relationship between weight change and related factors in subjects with type 2 diabetes mellitus (T2DM) treated with liraglutide versus comparator diabetes therapies.. Twenty-six-week data from seven phase 3, randomized trials in the liraglutide T2DM development programme were analysed by trial and treatment group: liraglutide (1.2 and 1.8 mg), active comparator and placebo. Outcome measures included proportions of subjects in various weight change categories and their percentage weight change from baseline; impact of body mass index (BMI) and gastrointestinal (GI) adverse events (AEs) on weight change and correlation of weight change with change in glycosylated haemoglobin (HbA1c).. A number of subjects experienced >5% weight loss during the trials (24.4% liraglutide 1.8 mg and 17.7% liraglutide 1.2 mg; 17.7% exenatide, 10.0% sitagliptin, 3.6-7.0% sulphonylurea, 2.6% thiazolidinedione and 2.6% glargine; 9.9% placebo). More weight loss was seen with liraglutide 1.2 and 1.8 mg than with active comparators except exenatide. Across trials, higher initial BMI was associated with slightly greater weight loss with liraglutide. Mean weight loss increased slightly the longer GI AEs persisted. Although HbA1c reduction was slightly larger in higher weight loss categories across treatments (including placebo), sample sizes were small and no clear correlation could be determined. Liraglutide-treated subjects experienced additional HbA1c reduction beyond that which appeared weight induced; thus, not all HbA1c-lowering effect appears weight mediated.. The majority of liraglutide-treated T2DM subjects experienced weight loss in this analysis. Weight loss was greater and occurred more in glucagon-like peptide-1 receptor agonist-treated subjects than in active comparator-treated subjects. Topics: Blood Glucose; Body Mass Index; Diabetes Mellitus, Type 2; Exenatide; Female; Glucagon-Like Peptide 1; Glycated Hemoglobin; Humans; Hypoglycemic Agents; Insulin Glargine; Insulin, Long-Acting; Liraglutide; Male; Middle Aged; Peptides; Pyrazines; Sitagliptin Phosphate; Sulfonylurea Compounds; Thiazolidinediones; Triazoles; Venoms; Weight Loss | 2013 |
Taspoglutide, a once-weekly glucagon-like peptide 1 analogue, vs. insulin glargine titrated to target in patients with Type 2 diabetes: an open-label randomized trial.
To compare the efficacy and safety of once-weekly taspoglutide with insulin glargine in patients with advanced Type 2 diabetes failing metformin and sulphonylurea combination therapy.. This open-label, parallel-group, multi-centre trial randomized 1049 patients continuing metformin 1:1:1 to taspoglutide 10 mg once weekly, taspoglutide 20 mg once weekly or insulin glargine once daily with forced titration to fasting plasma glucose ≤ 6.1 mmol/l. Sulphonylureas were discontinued before randomization. The primary endpoint was change in HbA(1c) after 24 weeks.. After 24 weeks, least-square mean changes from baseline in HbA(1c) in patients receiving taspoglutide 10 mg [-8 mmol/mol (se 1)] [-0.77% (se 0.05)] or taspoglutide 20 mg [-11 mmol/mol (se 1)] [-0.98% (se 0.05)] were non-inferior to insulin glargine [-9 mmol/mol (se 1)] [-0.84% (se 0.05)]; treatment difference of 0.07% (95% CI -0.06 to 0.21) and -0.14% (95% CI -0.28 to -0.01), for taspoglutide 10 and 20 mg, respectively, vs. insulin glargine. Taspoglutide was associated with more adverse events (mainly gastrointestinal) and significantly less hypoglycaemia than insulin glargine.. Compared with insulin glargine, taspoglutide provided non-inferior HbA(1c) reductions associated with less hypoglycaemia, but more gastrointestinal adverse events. Topics: Adolescent; Adult; Aged; Diabetes Mellitus, Type 2; Drug Administration Schedule; Female; Glucagon-Like Peptide 1; Glycated Hemoglobin; Humans; Hypoglycemic Agents; Insulin Glargine; Insulin, Long-Acting; Male; Metformin; Middle Aged; Peptides; Treatment Outcome; Young Adult | 2013 |
A dipeptidyl peptidase-4 inhibitor, sitagliptin, exerts anti-inflammatory effects in type 2 diabetic patients.
Glucagon-like peptide-1 (GLP-1) exerts beneficial effects on the cardiovascular system. Here, we examined the effect of sitagliptin, a dipeptidyl peptidase-4 (DPP-4) inhibitor, on systemic inflammation and pro-inflammatory (M1)/anti-inflammatory (M2)-like phenotypes of peripheral blood monocytes in diabetic patients.. Forty-eight type 2 diabetic patients were divided into the following two groups: sitagliptin-treatment (50mg daily for 3months) (n=24) and untreated control (n=24) groups. Measurements were undertaken to assess changes in glucose-lipid metabolism, serum levels of inflammatory cytokines such as serum amyloid A-LDL (SAA-LDL), C-reactive protein (CRP), interleukin-6 (IL-6), IL-10 and tumor necrosis factor-α (TNF-α). Furthermore, the effects of sitagliptin treatment on M1/M2-like phenotypes in peripheral blood monocytes were examined.. Treatment with sitagliptin significantly decreased fasting plasma glucose, hemoglobin A1c (HbA1c), serum levels of inflammatory markers, such as SAA-LDL, CRP, and TNF-α. In contrast, sitagliptin increased serum IL-10, an anti-inflammatory cytokine, as well as plasma GLP-1. In addition, sitagliptin increased monocyte IL-10 expression and decreased monocyte TNF-α expression. Multivariate regression analysis revealed that the sitagliptin treatment was the only factor independently associated with an increase in monocyte IL-10 (β=0.499; R(2)=0.293, P<0.05). However, other factors including the improvement of glucose metabolism were not associated with the increase.. This study is the first to show that a DPP-4 inhibitor, sitagliptin, reduces inflammatory cytokines and improves the unfavorable M1/M2-like phenotypes of peripheral blood monocytes in Japanese type 2 diabetic patients. Topics: Blood Glucose; C-Reactive Protein; Cholesterol; Diabetes Mellitus, Type 2; Dipeptidyl-Peptidase IV Inhibitors; Female; Glucagon-Like Peptide 1; Humans; Inflammation; Interleukin-10; Interleukin-6; Leukocytes, Mononuclear; Male; Middle Aged; Multivariate Analysis; Prospective Studies; Pyrazines; Regression Analysis; Serum Amyloid A Protein; Sitagliptin Phosphate; Triazoles; Tumor Necrosis Factor-alpha | 2013 |
Exenatide once weekly versus liraglutide once daily in patients with type 2 diabetes (DURATION-6): a randomised, open-label study.
Glucagon-like peptide-1 receptor agonists exenatide and liraglutide have been shown to improve glycaemic control and reduce bodyweight in patients with type 2 diabetes. We compared the efficacy and safety of exenatide once weekly with liraglutide once daily in patients with type 2 diabetes.. We did a 26 week, open-label, randomised, parallel-group study at 105 sites in 19 countries between Jan 11, 2010, and Jan 17, 2011. Patients aged 18 years or older with type 2 diabetes treated with lifestyle modification and oral antihyperglycaemic drugs were randomly assigned (1:1), via a computer-generated randomisation sequence with a voice response system, to receive injections of once-daily liraglutide (1·8 mg) or once-weekly exenatide (2 mg). Participants and investigators were not masked to treatment assignment. The primary endpoint was change in glycated haemoglobin (HbA(1c)) from baseline to week 26. Analysis was by intention to treat. This trial is registered with ClinicalTrials.gov, number NCT01029886.. Of 912 randomised patients, 911 were included in the intention-to-treat analysis (450 liraglutide, 461 exenatide). The least-squares mean change in HbA(1c) was greater in patients in the liraglutide group (-1·48%, SE 0·05; n=386) than in those in the exenatide group (-1·28%, 0·05; 390) with the treatment difference (0·21%, 95% CI 0·08-0·33) not meeting predefined non-inferiority criteria (upper limit of CI <0·25%). The most common adverse events were nausea (93 [21%] in the liraglutide group vs 43 [9%] in the exenatide group), diarrhoea (59 [13%] vs 28 [6%]), and vomiting 48 [11%] vs 17 [4%]), which occurred less frequently in the exenatide group and with decreasing incidence over time in both groups. 24 (5%) patients allocated to liraglutide and 12 (3%) allocated to exenatide discontinued participation because of adverse events.. Both once daily liraglutide and once weekly exenatide led to improvements in glycaemic control, with greater reductions noted with liraglutide. These findings, plus differences in injection frequency and tolerability, could inform therapeutic decisions for treatment of patients with type 2 diabetes.. Eli Lilly and Company and Amylin Pharmaceuticals LLC. Topics: Diabetes Mellitus, Type 2; Drug Administration Schedule; Exenatide; Glucagon-Like Peptide 1; Glycated Hemoglobin; Humans; Hypoglycemic Agents; Liraglutide; Male; Middle Aged; Peptides; Treatment Outcome; Venoms | 2013 |
Postprandial glucose, insulin and gastrointestinal hormones in healthy and diabetic subjects fed a fructose-free and resistant starch type IV-enriched enteral formula.
Reducing the dietary glycaemic response has been proposed as a means of reducing the risk of diabetes.. To evaluate the effects of a new diabetes-specific formula (DSF) enriched with resistant starch type IV and fructose-free on postprandial glycaemia, insulinaemia and gastrointestinal hormones in healthy volunteers and in outpatient type 2 diabetics.. (1) Twenty-four healthy volunteers were divided into two groups: Group 1 ( n = 10) was provided 50 g of the carbohydrate (CHO) constituent of the new product and 50 g of glucose separated by 1 week; Group 2 ( n = 14) was provided 400 ml of the new DSF (T-Diet Plus(®) Diabet NP) and 400 ml of a control product separated by 1 week. (2) Ten type 2 diabetic patients received 400 ml of the new DSF and two other commercially available DSF (Glucerna(®) SR and Novasource(®) Diabet) on three occasions separated by 1 week. Venous blood samples were drawn at time 0 and at different times until 120 min. Glucose, insulin and gastrointestinal hormones were determined. Glycaemic and insulinaemic indices and glycaemic load were calculated.. The CHO constituent and the new DSF showed low glycaemic index and glycaemic load. In healthy subjects, insulin and C-peptide release were lower after administration of the CHO constituent as well as after the new DSF (P < 0.001). Ghrelin, glucagon-like peptide-1 (GLP-1) and glucose-dependent insulinotropic peptide (GIP) production were lower after intake of the CHO constituent (P ranging from <0.001 to 0.019) compared with glucose, and GIP was lower after ingestion of the new DSF (P = 0.002) than after the control product. In type 2 diabetic patients, glucose AUC was lower after the administration of the new DSF (P = 0.037) compared with the others.. Our results indicate that this new product could be beneficial for diabetic patients. Topics: Adult; Area Under Curve; Blood Glucose; C-Peptide; Diabetes Mellitus, Type 2; Dietary Carbohydrates; Dietary Fats, Unsaturated; Dietary Supplements; Enteral Nutrition; Fatty Acids, Omega-3; Female; Fructose; Gastric Inhibitory Polypeptide; Ghrelin; Glucagon-Like Peptide 1; Glycemic Index; Healthy Volunteers; Humans; Insulin; Lipids; Male; Middle Aged; Postprandial Period; Starch; Young Adult | 2013 |
Circulating Sfrp5 is a signature of obesity-related metabolic disorders and is regulated by glucose and liraglutide in humans.
Secreted frizzled-related protein-5 (Sfrp5) is a novel adipocyte-secreted hormone that has been shown to link obesity with diabetes. Studies in mice have revealed that Sfrp5 represents a potential target for the control of obesity-linked abnormalities in glucose homeostasis.. Our objective was to gain insight into the physiological role of circulating Sfrp5 in humans.. We conducted a series of cross-sectional and interventional studies of the general population and outpatients of the Internal Medicine Department at the Second Affiliated Hospital, Chongqing Medical University, Chongqing, China. Subjects included 104 healthy subjects, 101 with impaired glucose tolerance, and 112 with newly diagnosed type 2 diabetes mellitus and, in a separate study, 30 healthy women, and 32 women with polycystic ovarian syndrome (PCOS). Oral glucose tolerance test and euglycemic-hyperinsulinemic clamp were performed to assess glucose tolerance and insulin sensitivity.. Circulating Sfrp5 was significantly lower in both impaired glucose intolerance and newly diagnosed type 2 diabetes mellitus than in individuals with normal glucose tolerance (P < 0.01). Overweight/obese subjects had significantly lower Sfrp5 levels than lean individuals (P < 0.01), but females had higher Sfrp5 levels than males (P < 0.05). In a separate study, Sfrp5 levels were lower in PCOS women than healthy women (P < 0.05). Moreover, circulating Sfrp5 correlated with markers of adiposity, including body mass index, waist-to-hip ratio, percent body fat, homeostasis model assessment of insulin resistance, lipid profile, and adiponectin. Hyperglycemia decreased circulating Sfrp5 levels, whereas liraglutide increased Sfrp5 levels. In the euglycemic-hyperinsulinemic state, circulating Sfrp5 was significantly decreased in healthy women but not in PCOS women.. We conclude that circulating Sfrp5 is likely to play a major role in insulin resistance in humans. Topics: Adaptor Proteins, Signal Transducing; Adult; Aged; Biomarkers; Cross-Sectional Studies; Diabetes Mellitus, Type 2; Eye Proteins; Female; Glucagon-Like Peptide 1; Glucose; Glucose Intolerance; Humans; Hypoglycemic Agents; Insulin Resistance; Liraglutide; Male; Membrane Proteins; Metabolic Diseases; Middle Aged; Obesity | 2013 |
Effect of additional administration of acarbose on blood glucose fluctuations and postprandial hyperglycemia in patients with type 2 diabetes mellitus under treatment with alogliptin.
Acarbose was administered at 300 mg/day to patients with type 2 diabetes mellitus (T2DM) who had been taking 25 mg/day of alogliptin, and levels of blood glucose were analyzed by continuous glucose monitoring (CGM) for 3 days. The mean blood glucose level with acarbose (136.4 ± 30.7 mg/dL) did not differ significantly from that without acarbose (141.7 ± 28.3 mg/dL). However, in the condition of the combination therapy, there were significant decreases in the standard deviation of the mean blood glucose levels for the 24-hour period (27.6 ± 9.1 vs. 16.2 ± 6.9 mg/dL, p<0.001) and mean amplitude of glycemic excursions (MAGE) (65.8 ± 26.1 vs. 38.8 ± 19.2 mg/dL, p=0.010). In addition, a meal tolerance test was conducted to monitor changes in insulin secretion and active GLP-1 and total GIP values. Ten subjects (5 males, 5 females) of 54.9 ± 6.9 years with BMI 25.9 ± 5.2 kg/m² and HbAlc 9.2 ± 1.2% were enrolled. In the meal tolerance test, active GLP-1 values before and after acarbose administration were 17.0 ± 5.8 and 24.1 ± 9.3 pmol·hr/mL (p=0.054), respectively, showing an increasing tendency, and total GIP(AUC0-180) values were 685.9 ± 209.7 and 404.4 ± 173.7 pmol·hr/mL, respectively, showing a significant decrease (p=0.010). The results indicate that the combined administration of both inhibitors is effective not only in decreasing blood glucose fluctuations and preventing postprandial insulin secretion. The beneficial effects may also protect the endocrine pancreas and inhibit body weight gain. Topics: Acarbose; Blood Glucose; Body Mass Index; Diabetes Mellitus, Type 2; Dipeptidyl-Peptidase IV Inhibitors; Drug Therapy, Combination; Enzyme Inhibitors; Female; Glucagon-Like Peptide 1; Glycated Hemoglobin; Glycoside Hydrolase Inhibitors; Humans; Hyperglycemia; Hypoglycemia; Insulin; Insulin Secretion; Islets of Langerhans; Male; Middle Aged; Overweight; Piperidines; Uracil; Weight Gain | 2013 |
The effect of a bile acid sequestrant on glucose metabolism in subjects with type 2 diabetes.
We designed an experiment to examine the effect of bile acid sequestration with Colesevelam on fasting and postprandial glucose metabolism in type 2 diabetes. To do so, we tested the hypothesis that Colesevelam increases the disposition index (DI), and this increase is associated with increased glucagon-like peptide-1 (GLP-1) concentrations. Thirty-eight subjects on metformin monotherapy were studied using a double-blind, placebo-controlled, parallel-group design. Subjects were studied before and after 12 weeks of Colesevelam or placebo using a labeled triple-tracer mixed meal to measure the rate of meal appearance (Meal Ra), endogenous glucose production (EGP), and glucose disappearance (Rd). Insulin sensitivity and β-cell responsivity indices were estimated using the oral minimal model and then used to calculate DI. Therapy with Colesevelam was associated with a decrease in fasting (7.0 ± 0.2 vs. 6.6 ± 0.2 mmol/L; P = 0.004) and postprandial glucose concentrations (3,145 ± 138 vs. 2,896 ± 127 mmol/6 h; P = 0.01) in the absence of a change in insulin concentrations. Minimal model-derived indices of insulin secretion and action were unchanged. Postprandial GLP-1 concentrations were not altered by Colesevelam. Although EGP and Rd were unchanged, integrated Meal Ra was decreased by Colesevelam (5,191 ± 204 vs. 5,817 ± 204 μmol/kg/6 h; P = 0.04), suggesting increased splanchnic sequestration of meal-derived glucose. Topics: Allylamine; Anticholesteremic Agents; Blood Glucose; C-Peptide; Colesevelam Hydrochloride; Diabetes Mellitus, Type 2; Double-Blind Method; Fasting; Female; Glucagon; Glucagon-Like Peptide 1; Glucose; Humans; Insulin; Insulin Resistance; Male; Middle Aged; Postprandial Period | 2013 |
Zinc-α2-glycoprotein is associated with insulin resistance in humans and is regulated by hyperglycemia, hyperinsulinemia, or liraglutide administration: cross-sectional and interventional studies in normal subjects, insulin-resistant subjects, and subject
Zinc-α2-glycoprotein (ZAG) has been proposed to play a role in the pathogenesis of insulin resistance. Previous studies in humans and in rodents have produced conflicting results regarding the link between ZAG and insulin resistance. The objective of this study was to examine the relationships between ZAG and insulin resistance in cross-sectional and interventional studies.. Serum ZAG (determined with ELISA) was compared with various parameters related to insulin resistance in subjects with normal glucose tolerance, impaired glucose tolerance (IGT), and newly diagnosed type 2 diabetes mellitus (T2DM), and in women with or without polycystic ovary syndrome (PCOS). Euglycemic-hyperinsulinemic clamps were performed in healthy and PCOS women. Real-time RT-PCR and Western blotting were used to assess mRNA and protein expression of ZAG. The effect of a glucagon-like peptide-1 agonist on ZAG was studied in a 12-week liraglutide treatment trial.. Circulating ZAG was lower in patients with IGT and newly diagnosed T2DM than in controls. Circulating ZAG correlated positively with HDL cholesterol and adiponectin, and correlated inversely with BMI, waist-to-hip ratio, body fat percentage, triglycerides, fasting blood glucose, fasting insulin, HbA1c, and homeostasis model assessment of insulin resistance (HOMA-IR). On multivariate analysis, ZAG was independently associated with BMI, HOMA-IR, and adiponectin. ZAG mRNA and protein were decreased in adipose tissue of T2DM patients. Moreover, circulating ZAG levels were lower in women with PCOS than in women with high insulin sensitivity. Liraglutide treatment for 12 weeks significantly increased circulating ZAG levels.. We conclude that ZAG may be an adipokine associated with insulin resistance. Topics: Adipokines; Adult; Aged; Cross-Sectional Studies; Diabetes Mellitus, Type 2; Female; Glucagon-Like Peptide 1; Humans; Hyperglycemia; Hyperinsulinism; Insulin Resistance; Liraglutide; Male; Middle Aged; Polycystic Ovary Syndrome; Seminal Plasma Proteins; Zn-Alpha-2-Glycoprotein | 2013 |
Efficacy and safety of the dipeptidyl peptidase-4 inhibitor gemigliptin compared with sitagliptin added to ongoing metformin therapy in patients with type 2 diabetes inadequately controlled with metformin alone.
This study was designed to assess the efficacy and safety of a dipeptidyl peptidase-4 inhibitor, gemigliptin versus sitagliptin added to metformin in patients with type 2 diabetes.. We conducted a double-blind, randomized, active-controlled trial in 425 Asian patients with inadequately controlled type 2 diabetes being treated with metformin alone. Eligible patients were randomized into three groups: 50 mg gemigliptin qd, 25 mg gemigliptin bid or sitagliptin 100 mg qd added to ongoing metformin treatment for 24 weeks. Haemoglobin A1c (HbA1c) and fasting plasma glucose (FPG) were measured periodically, and oral glucose tolerance tests were performed at baseline and 24 weeks after starting the treatment regimen.. Twenty-four weeks later, adding gemigliptin (50 mg/day) to ongoing metformin therapy significantly improved glycaemic control. Reduction in HbA1c caused by 50 mg gemigliptin qd (-0.77% ± 0.8) was non-inferior to that caused by 100 mg sitagliptin qd (-0.8% ± 0.85). Proportion of patients achieving HbA1c <7% while taking 25 mg gemigliptin bid (50%) or 50 mg gemigliptin qd (54.07%) was comparable to the results with 100 mg sitagliptin qd (48.87%). There were significant decreases in FPG, postprandial glucose and AUC0-2 h glucose, as well as increases in GLP-1 and β cell sensitivity to glucose (supported by homeostasis model assessment of β-cell function, postprandial 2-h c-peptide and insulinogenic index) in patients receiving gemigliptin treatment with their metformin therapy. There was no increased risk of adverse effects with this dose of gemigliptin compared with sitagliptin 100 mg qd.. Addition of gemigliptin 50 mg daily to metformin was shown to be efficacious, well tolerated and non-inferior to sitagliptin in patients with type 2 diabetes mellitus. Topics: Adolescent; Adult; Aged; Asian People; Blood Glucose; Diabetes Mellitus, Type 2; Dipeptidyl-Peptidase IV Inhibitors; Double-Blind Method; Fasting; Female; Glucagon-Like Peptide 1; Glucose Tolerance Test; Glycated Hemoglobin; Humans; Hypoglycemic Agents; Male; Metformin; Middle Aged; Piperidones; Pyrazines; Pyrimidines; Republic of Korea; Risk Reduction Behavior; Sitagliptin Phosphate; Treatment Outcome; Triazoles | 2013 |
Sitagliptin improves beta-cell function in patients with acute coronary syndromes and newly diagnosed glucose abnormalities--the BEGAMI study.
Newly detected impaired glucose tolerance (IGT) or type 2 diabetes mellitus (T2DM) are common in patients with acute coronary syndrome (ACS; i.e. unstable angina/myocardial infarction) and related to disturbed beta-cell function. The aim of this study is to test the hypothesis that treatment with a dipeptidyl peptidase-4 inhibitor initiated soon after a coronary event improves beta-cell function.. Acute coronary syndrome ACS patients with IGT or T2DM (n = 71), screened by oral glucose tolerance test (OGTT) 4-23 days (median 6 days) after hospital admission, were randomly assigned to sitagliptin 100 mg (n = 34) or placebo (n = 37) and treated for a duration of 12 weeks. All patients received lifestyle advice but no glucose-lowering agents other than the study drug. The study end-point was beta-cell function assessed using the insulinogenic index (IGI = ΔInsulin30 /ΔGlucose30 ), derived from an OGTT, and acute insulin response to glucose (AIRg) assessed by a frequently sampled intravenous glucose tolerance test.. The IGI and AIRg did not differ at baseline between the sitagliptin and placebo groups (69.9 vs. 66.4 pmol mmol(-1) and 1394 vs. 1106 pmol L(-1) min(-1) respectively). After 12 weeks, the IGI was 85.0 in the sitagliptin and 58.1 pmol/mmol in the placebo group (P = 0.013) and AIRg was 1909 and 1043 pmol L(-1) min(-1) (P < 0.0001) in the sitagliptin and placebo groups respectively. Fasting glucose at baseline was 6.1 mmol L(-1) in sitagliptin-treated patients and 6.0 mmol L(-1) in those who received placebo compared with 5.8 and 5.9 mmol L(-1) respectively, after 12 weeks of treatment. Post load glucose metabolism improved in significantly more sitagliptin-treated patients compared with the placebo group (P = 0.003). Sitagliptin was well tolerated.. Sitagliptin improved beta-cell function and glucose perturbations in patients with ACS and newly diagnosed glucose disturbances. Topics: Acute Coronary Syndrome; Blood Glucose; Diabetes Mellitus, Type 2; Double-Blind Method; Follow-Up Studies; Glucagon-Like Peptide 1; Glucose Intolerance; Glucose Tolerance Test; Humans; Hypoglycemic Agents; Insulin-Secreting Cells; Prospective Studies; Pyrazines; Sitagliptin Phosphate; Treatment Outcome; Triazoles | 2013 |
Effects of a D-xylose preload with or without sitagliptin on gastric emptying, glucagon-like peptide-1, and postprandial glycemia in type 2 diabetes.
Macronutrient "preloads" can reduce postprandial glycemia by slowing gastric emptying and stimulating glucagon-like peptide-1 (GLP-1) secretion. An ideal preload would entail minimal additional energy intake and might be optimized by concurrent inhibition of dipeptidyl peptidase-4 (DPP-4). We evaluated the effects of a low-energy D-xylose preload, with or without sitagliptin, on gastric emptying, plasma intact GLP-1 concentrations, and postprandial glycemia in type 2 diabetes.. Twelve type 2 diabetic patients were studied on four occasions each. After 100 mg sitagliptin (S) or placebo (P) and an overnight fast, patients consumed a preload drink containing either 50 g D-xylose (X) or 80 mg sucralose (control [C]), followed after 40 min by a mashed potato meal labeled with (13)C-octanoate. Blood was sampled at intervals. Gastric emptying was determined.. Both peak blood glucose and the amplitude of glycemic excursion were lower after PX and SC than PC (P < 0.01 for each) and were lowest after SX (P < 0.05 for each), while overall blood glucose was lower after SX than PC (P < 0.05). The postprandial insulin-to-glucose ratio was attenuated (P < 0.05) and gastric emptying was slower (P < 0.01) after D-xylose, without any effect of sitagliptin. Plasma GLP-1 concentrations were higher after D-xylose than control only before the meal (P < 0.05) but were sustained postprandially when combined with sitagliptin (P < 0.05).. In type 2 diabetes, acute administration of a D-xylose preload reduces postprandial glycemia and enhances the effect of a DPP-4 inhibitor. Topics: Aged; Blood Glucose; Diabetes Mellitus, Type 2; Dipeptidyl-Peptidase IV Inhibitors; Enzyme-Linked Immunosorbent Assay; Female; Gastric Emptying; Glucagon-Like Peptide 1; Humans; Insulin; Male; Middle Aged; Postprandial Period; Pyrazines; Radioimmunoassay; Sitagliptin Phosphate; Triazoles; Xylose | 2013 |
Pharmacodynamic characteristics of lixisenatide once daily versus liraglutide once daily in patients with type 2 diabetes insufficiently controlled on metformin.
Assess the pharmacodynamics of lixisenatide once daily (QD) versus liraglutide QD in type 2 diabetes insufficiently controlled on metformin.. In this 28-day, randomized, open-label, parallel-group, multicentre study (NCT01175473), patients (mean HbA1c 7.3%) received subcutaneous lixisenatide QD (10 µg weeks 1-2, then 20 µg; n = 77) or liraglutide QD (0.6 mg week 1, 1.2 mg week 2, then 1.8 mg; n = 71) 30 min before breakfast. Primary endpoint was change in postprandial plasma glucose (PPG) exposure from baseline to day 28 during a breakfast test meal.. Lixisenatide reduced PPG significantly more than liraglutide [mean change in AUC(0:30-4:30h) : -12.6 vs. -4.0 h·mmol/L, respectively; p < 0.0001 (0:30 h = start of meal)]. Change in maximum PPG excursion was -3.9 mmol/l vs. -1.4 mmol/l, respectively (p < 0.0001). More lixisenatide-treated patients achieved 2-h PPG <7.8 mmol/l (69% vs. 29%). Changes in fasting plasma glucose were greater with liraglutide (-0.3 vs. -1.3 mmol/l, p < 0.0001). Lixisenatide provided greater decreases in postprandial glucagon (p < 0.05), insulin (p < 0.0001) and C-peptide (p < 0.0001). Mean HbA1c decreased in both treatment groups (from 7.2% to 6.9% with lixisenatide vs. 7.4% to 6.9% with liraglutide) as did body weight (-1.6 kg vs. -2.4 kg, respectively). Overall incidence of adverse events was lower with lixisenatide (55%) versus liraglutide (65%), with no serious events or hypoglycaemia reported.. Once daily prebreakfast lixisenatide provided a significantly greater reduction in PPG (AUC) during a morning test meal versus prebreakfast liraglutide. Lixisenatide provided significant decreases in postprandial insulin, C-peptide (vs. an increase with liraglutide) and glucagon, and better gastrointestinal tolerability than liraglutide. Topics: Adult; Aged; C-Peptide; Diabetes Mellitus, Type 2; Drug Administration Schedule; Drug Resistance; Female; Glucagon; Glucagon-Like Peptide 1; Glycated Hemoglobin; Humans; Hyperglycemia; Hyperinsulinism; Hypoglycemic Agents; Incretins; Injections, Subcutaneous; Liraglutide; Male; Metformin; Middle Aged; Peptides | 2013 |
Miglitol administered before breakfast increased plasma active glucagon-like peptide-1 (GLP-1) levels after lunch in patients with type 2 diabetes treated with sitagliptin.
We recently reported that the administration of miglitol alone just before breakfast improved postprandial hyperglycemia and increased active glucagon-like peptide-1 (GLP-1) levels after lunch in men without diabetes. Miglitol and dipeptidyl peptidase-4 inhibitors, such as sitagliptin, enhance plasma active GLP-1 concentrations via different mechanisms; therefore, combined therapy with these agents was more effective than monotherapy. In this study, we compared the effectiveness of the administration of miglitol alone just before breakfast on the plasma glucose, serum insulin and glucagon, and plasma incretin levels in sitagliptin-treated patients with type 2 diabetes. We measured the plasma glucose, serum insulin and glucagon, plasma active GLP-1, and total glucose-dependent insulinotropic polypeptide levels before breakfast, at 120 min after breakfast, before lunch, and 60 and 120 min after lunch in patients with diabetes who are receiving sitagliptin. This trial was performed for the following 2 days on each subject (Day 1: no miglitol, Day 2: miglitol alone [50 mg] administered just before breakfast). The area under the curve (AUC) of the plasma glucose levels after lunch in the miglitol-treated group tended to be lower than that in the miglitol-untreated group, but the difference was not statistically significant. Miglitol alone administered at breakfast increased the AUC of the active plasma GLP-1 levels after lunch in sitagliptin-treated patients with diabetes. Our results suggest that the once-daily administration of miglitol as a "GLP-1 enhancer" in combination with sitagliptin was effective for the treatment for patients with diabetes. Topics: 1-Deoxynojirimycin; Blood Glucose; Diabetes Mellitus, Type 2; Dipeptidyl-Peptidase IV Inhibitors; Drug Administration Schedule; Drug Therapy, Combination; Female; Food-Drug Interactions; Glucagon; Glucagon-Like Peptide 1; Humans; Hypoglycemic Agents; Insulin; Male; Middle Aged; Postprandial Period; Pyrazines; Sitagliptin Phosphate; Triazoles | 2012 |
Effects of variations in duodenal glucose load on glycaemic, insulin, and incretin responses in type 2 diabetes.
Postprandial glucagon-like peptide-1 (GLP-1) secretion and the 'incretin effect' have been reported to be deficient in Type 2 diabetes, but most studies have not controlled for variations in the rate of gastric emptying. We evaluated blood glucose, and plasma insulin, GLP-1 and glucose-dependent insulinotropic polypeptide (GIP) responses to intraduodenal glucose in Type 2 diabetes, and compared these with data from healthy controls.. Eight males with well-controlled Type 2 diabetes, managed by diet alone, were studied on four occasions in single-blind, randomized order. Blood glucose, and plasma insulin, GLP-1, and GIP were measured during 120-min intraduodenal glucose infusions at 1 kcal/min (G1), 2 kcal/min (G2) and 4 kcal/min (G4) or saline control.. Type 2 patients had higher basal (P < 0.0005) and incremental (P < 0.0005) blood glucose responses to G2 and G4, when compared with healthy controls. In both groups, the stimulation of insulin and GLP-1 by increasing glucose loads was not linear; responses to G1 and G2 were minimal, whereas responses to G4 were much greater (P < 0.005 for each) (incremental area under the GLP-1 curve 224 ± 65, 756 ± 331 and 2807 ± 473 pmol/l.min, respectively, in Type 2 patients and 373 ± 231, 505 ± 161 and 1742 ± 456 pmol/l.min, respectively, in healthy controls). The GLP-1 responses appeared comparable in the two groups. In both groups there was a load-dependent increase in plasma GIP with no difference between them.. In patients with well-controlled Type 2 diabetes, blood glucose, insulin and GLP-1 responses are critically dependent on the small intestinal glucose load, and GLP-1 responses are not deficient. Topics: Analysis of Variance; Blood Glucose; Diabetes Mellitus, Type 2; Duodenum; Gastric Emptying; Gastric Inhibitory Polypeptide; Glucagon-Like Peptide 1; Glucose; Humans; Incretins; Insulin; Insulin Secretion; Male; Middle Aged; Postprandial Period; Single-Blind Method | 2012 |
Effects of vildagliptin on postprandial markers of bone resorption and calcium homeostasis in recently diagnosed, well-controlled type 2 diabetes patients.
Bone metabolism is a dynamic process that is influenced by food ingestion. Endogenous incretins have been shown to be important regulators of bone turnover. The aim of the present study was to assess whether a dipeptidylpeptidase (DPP)-4 inhibitor affects markers of bone resorption and calcium homeostasis.. The present study was a single-center, double blind, randomized clinical trail. Fifty-nine drug-naïve patients with type 2 diabetes (T2D) were randomized to either 1 year treatment with the DPP-4 inhibitor vildagliptin (100 mg, once daily; n = 29) or placebo (n = 30). Patients received a standardized breakfast after measurement of serum concentrations of cross-linked C-terminal telopeptide (s-CTx), a bone resorption marker influenced by food intake, before and after 50 weeks treatment.. Vildagliptin did not change postprandial s-CTx concentrations compared with pretreatment levels (between-group ratio 1.15 ± 0.17; P = 0.320). Fasting serum alkaline phosphatase, calcium, and phosphate were also unaffected y 1 year treatment with vildagliptin.. Treatment with vildagliptin for 1 year was not associated with changes in markers of bone resorption and calcium homeostasis in drug-naïve patients with T2D and mild hyperglycemia. Topics: Adamantane; Aged; Alkaline Phosphatase; Biomarkers; Blood Glucose; Bone and Bones; Bone Resorption; Calcium; Collagen Type I; Diabetes Mellitus, Type 2; Dipeptidyl-Peptidase IV Inhibitors; Double-Blind Method; Female; Glucagon-Like Peptide 1; Homeostasis; Humans; Insulin; Male; Middle Aged; Netherlands; Nitriles; Peptides; Phosphates; Postprandial Period; Pyrrolidines; Time Factors; Treatment Outcome; Vildagliptin | 2012 |
Comparisons of the effects of 12-week administration of miglitol and voglibose on the responses of plasma incretins after a mixed meal in Japanese type 2 diabetic patients.
To compare the effects of miglitol [an alpha-glucosidase inhibitor (AGI) absorbed in the intestine] and voglibose (an AGI not absorbed) on plasma glucagon-like peptide-1 (GLP-1) and gastric inhibitory polypeptide (GIP) levels, 26 and 24 Japanese type 2 diabetic patients were randomly assigned to receive miglitol or voglibose, respectively. After 12-week administration of both drugs, during 2-h meal tolerance test, plasma glucose, serum insulin and total GIP were significantly decreased and active GLP-1 was significantly increased. Miglitol group showed a significantly lower total GIP level than voglibose group. Miglitol, but not voglibose, significantly reduced body weight (BW). In all participants, the relative change in BW was positively correlated with that of insulin significantly and of GIP with a weak tendency, but not of GLP-1. In conclusion, both drugs can enhance postprandial GLP-1 responses and reduce GIP responses. The significant BW reduction by miglitol might be attributable to its strong GIP-reducing efficacy. Topics: 1-Deoxynojirimycin; Asian People; Diabetes Mellitus, Type 2; Drug Administration Schedule; Female; Gastric Inhibitory Polypeptide; Glucagon-Like Peptide 1; Humans; Hypoglycemic Agents; Incretins; Inositol; Male; Middle Aged; Obesity; Postprandial Period | 2012 |
Effect of bile acid sequestrants on glucose metabolism, hepatic de novo lipogenesis, and cholesterol and bile acid kinetics in type 2 diabetes: a randomised controlled study.
The primary aim of this completed multicentre randomised, parallel, double-blind placebo-controlled study was to elucidate the mechanisms of glucose-lowering with colesevelam and secondarily to investigate its effects on lipid metabolism (hepatic de novo lipogenesis, cholesterol and bile acid synthesis).. Participants with type 2 diabetes (HbA(1c) 6.7-10.0% [50-86 mmol/mol], fasting glucose <16.7 mmol/l, fasting triacylglycerols <3.9 mmol/l and LDL-cholesterol >1.55 mmol/l) treated with diet and exercise, sulfonylurea, metformin or a combination thereof, were randomised by a central coordinator to either 3.75 g/day colesevelam (n = 30) or placebo (n = 30) for 12 weeks at three clinical sites in the USA. The primary measure was the change from baseline in glucose kinetics with colesevelam compared to placebo treatment. Fasting and postprandial glucose, lipid and bile acid pathways were measured at baseline and post-treatment using stable isotope techniques. Plasma glucose, insulin, total glucagon-like peptide-1 (GLP-1), total glucose-dependent insulinotropic polypeptide (GIP), glucagon and fibroblast growth factor-19 (FGF-19) concentrations were measured during the fasting state and following a meal tolerance test. Data was collected by people blinded to treatment.. Compared with placebo, colesevelam improved HbA(1c) (mean change from baseline of 0.3 [SD 1.1]% for placebo [n = 28] and -0.3 [1.1]% for colesevelam [n = 26]), glucose concentrations, fasting plasma glucose clearance and glycolytic disposal of oral glucose. Colesevelam did not affect gluconeogenesis or appearance rate (absorption) of oral glucose. Fasting endogenous glucose production and glycogenolysis significantly increased with placebo but were unchanged with colesevelam (treatment effect did not reach statistical significance). Compared with placebo, colesevelam increased total GLP-1 and GIP concentrations and improved HOMA-beta cell function while insulin, glucagon and HOMA-insulin resistance were unchanged. Colesevelam increased cholesterol and bile acid synthesis and decreased FGF-19 concentrations. However, no effect was seen on fractional hepatic de novo lipogenesis.. Colesevelam, a non-absorbed bile acid sequestrant, increased circulating incretins and improved tissue glucose metabolism in both the fasting and postprandial states in a manner different from other approved oral agents.. ClinicalTrials.gov NCT00596427. The study was funded by Daiichi Sankyo. Topics: Administration, Oral; Adult; Aged; Allylamine; Anticholesteremic Agents; Bile Acids and Salts; Blood Glucose; Cholesterol; Colesevelam Hydrochloride; Diabetes Mellitus, Type 2; Female; Fibroblast Growth Factors; Gastric Inhibitory Polypeptide; Glucagon-Like Peptide 1; Glucose; Glycated Hemoglobin; Humans; Insulin; Kinetics; Lipid Metabolism; Lipogenesis; Liver; Male; Middle Aged; Placebos; Postprandial Period | 2012 |
Dosing rationale for liraglutide in type 2 diabetes mellitus: a pharmacometric assessment.
The glucagon-like peptide-1 (GLP-1) receptor agonist liraglutide was approved in 2010 by the US Food and Drug Administration (FDA) as an adjunct treatment to diet and exercise to improve glycemic control in adults with type 2 diabetes mellitus. This article provides insights into the use of pharmacometric analyses for regulatory review with a focus on the dosing recommendations. The assessment was based on the totality of exploratory and confirmatory analysis of dose-finding and pivotal clinical data and was structured around a set of key questions in accordance with current FDA review practice. For the pharmacometric review of liraglutide, the key questions focused on exposure-response relationships for effects on fasting plasma glucose, hemoglobin A(1c), and calcitonin and on variability in exposure across demographic subgroups of patients. The importance of conducting exploratory exposure-response analysis and population pharmacokinetic studies in clinical drug development to support dosing recommendations is highlighted. Topics: Adolescent; Adult; Aged; Aged, 80 and over; Blood Glucose; Calcitonin; Diabetes Mellitus, Type 2; Dose-Response Relationship, Drug; Fasting; Female; Glucagon-Like Peptide 1; Glycated Hemoglobin; Humans; Hypoglycemic Agents; Liraglutide; Male; Middle Aged; Young Adult | 2012 |
Addition of liraglutide in patients with Type 2 diabetes well controlled on metformin monotherapy improves several markers of vascular function.
The aim of this study was to investigate the vascular effects of liraglutide in patients well controlled on metformin monotherapy.. Forty-four patients with Type 2 diabetes were included in the study. Main inclusion criteria were: pretreatment with metformin on a stable dosage, HbA(1c) < 53 mmol/mol (7.0%), age 30-65 years. Patients were randomized to receive additional liraglutide or to remain on metformin monotherapy. After 6 weeks (1.2 mg) and after 12 weeks (1.8 mg), venous blood was taken for the measurement of several laboratory markers characterizing vascular and endothelial function. In addition, retinal microvascular endothelial function and arterial stiffness were measured.. HbA(1c) levels declined from 45 ± 4 mmol/mol (6.3 ± 0.4%; mean ± SD) to 40 ± 3 mmol/mol (5.8 ± 0.3%) during liraglutide treatment. Asymmetric dimethylarginin was reduced by liraglutide treatment from 0.39 ± 0.08 to 0.35 ± 0.06 μmol/l, E-selectin from 43.6 ± 15.4 to 40.8 ± 15.1 ng/ml, plasminogen activator inhibitor 1 from 861.6 ± 584.3 to 666.1 ± 499.4 ng/ml and intact proinsulin from 9.0 ± 7.2 to 7.0 ± 4.8 pmol/l at 12 weeks of treatment. The microvascular response to flicker light increased from 7.0 ± 15.1 to 15.4 ± 11.5% after 6 weeks and to 11.1 ± 9.9% after 12 weeks. No change could be observed for high-sensitivity C-reactive protein, monocyte chemotactic protein 1, vascular cell adhesion molecule or arterial stiffness parameters.. In patients with Type 2 diabetes, well controlled with metformin monotherapy, addition of liraglutide improves several cardiovascular risk markers beyond glycaemic control. Topics: Adult; Aged; Arginine; Biomarkers; Blood Glucose; Diabetes Mellitus, Type 2; Drug Therapy, Combination; E-Selectin; Endothelium, Vascular; Female; Glucagon-Like Peptide 1; Humans; Hypoglycemic Agents; Liraglutide; Male; Metformin; Microcirculation; Middle Aged; Plasminogen Activator Inhibitor 1; Proinsulin; Prospective Studies | 2012 |
Effects of JNJ-38431055, a novel GPR119 receptor agonist, in randomized, double-blind, placebo-controlled studies in subjects with type 2 diabetes.
G-protein coupled receptor agonists are currently under investigation for their potential utility in patients with type 2 diabetes mellitus (T2DM). The objective was to determine the pharmacokinetics, pharmacodynamics, safety and tolerability of GPR119 agonist, JNJ-38431055 in T2DM subjects.. This was a randomized, double-blind, placebo- and positive-controled, single-dose cross-over study and a randomized, double-blind, placebo-controled multiple-dose parallel design study. The study was conducted at 4 US research centres. Two different experiments involving 25 and 32 different subjects were performed in male and female subjects, aged 25-60 years, mean body mass index between 22 and 39.9 kg/m2 who had T2DM diagnosed 6 months to 10 years before screening. JNJ-38431055 (100 and 500 mg) or sitagliptin (100 mg) as a single-dose or JNJ-38431055 (500 mg) once daily for 14 consecutive days were tested. Effects on stimulated plasma glucose, insulin, C-peptide and incretin concentrations were pre-specified outcomes.. JNJ-38431055 was well tolerated and not associated with hypoglycaemia. Plasma systemic exposure of JNJ-38431055 increased as the dose increased, was approximately two-fold greater after multiple-dose administration, and attained steady-state after approximately 8 days. Compared with placebo, single-dose administration of oral JNJ-38431055 decreased glucose excursion during an oral glucose tolerance test, but multiple-dose administration did not alter 24-h weighted mean glucose. Multiple dosing of JNJ-38431055 increased post-meal total glucagon-like peptide 1 and gastric insulinotropic peptide concentrations compared to baseline.. These studies provide evidence of limited glucose lowering and incretin activity for JNJ-38431055 in subjects with T2DM. Topics: Administration, Oral; Adult; Blood Glucose; Cross-Over Studies; Diabetes Mellitus, Type 2; Dipeptidyl-Peptidase IV Inhibitors; Double-Blind Method; Female; Glucagon-Like Peptide 1; Glucose Tolerance Test; Humans; Incretins; Male; Middle Aged; Pyrazines; Receptors, G-Protein-Coupled; Sitagliptin Phosphate; Treatment Outcome; Triazoles | 2012 |
Effects of diet soda on gut hormones in youths with diabetes.
In patients with type 2 diabetes, but not type 1 diabetes, abnormal secretion of incretins in response to oral nutrients has been described. In healthy youths, we recently reported accentuated glucagon-like peptide 1 (GLP-1) secretion in response to a diet soda sweetened with sucralose and acesulfame-K. In this study, we examined the effect of diet soda on gut hormones in youths with diabetes.. Subjects aged 12-25 years with type 1 diabetes (n = 9) or type 2 diabetes (n = 10), or healthy control participants (n = 25) drank 240 mL cola-flavored caffeine-free diet soda or carbonated water, followed by a 75-g glucose load, in a randomized, cross-over design. Glucose, C-peptide, GLP-1, glucose-dependent insulinotropic peptide (GIP), and peptide Tyr-Tyr (PYY) were measured for 180 min. Glucose and GLP-1 have previously been reported for the healthy control subjects.. GLP-1 area under the curve (AUC) was 43% higher after ingestion of diet soda versus carbonated water in individuals with type 1 diabetes (P = 0.020), similar to control subjects (34% higher, P = 0.029), but was unaffected by diet soda in patients with type 2 diabetes (P = 0.92). Glucose, C-peptide, GIP, and PYY AUC were not statistically different between the two conditions in any group.. Ingestion of diet soda before a glucose load augmented GLP-1 secretion in type 1 diabetic and control subjects but not type 2 diabetic subjects. GIP and PYY secretion were not affected by diet soda. The clinical significance of this increased GLP-1 secretion, and its absence in youths with type 2 diabetes, needs to be determined. Topics: Adolescent; Adult; Blood Glucose; C-Peptide; Carbonated Beverages; Child; Cross-Over Studies; Diabetes Mellitus; Diabetes Mellitus, Type 1; Diabetes Mellitus, Type 2; Female; Gastric Inhibitory Polypeptide; Gastrointestinal Hormones; Glucagon-Like Peptide 1; Glucose; Humans; Male; Peptide YY; Young Adult | 2012 |
Mechanism-based population modelling of the effects of vildagliptin on GLP-1, glucose and insulin in patients with type 2 diabetes.
To build a mechanism-based population pharmacodynamic model to describe and predict the time course of active GLP-1, glucose and insulin in type 2 diabetic patients after treatment with various doses of vildagliptin.. Vildagliptin concentrations, DPP-4 activity, active GLP-1, glucose and insulin concentrations from 13 type 2 diabetic patients after oral vildagliptin doses of 10, 25 or 100 mg and placebo twice daily for 28 days were co-modelled. The population PK/PD model was developed utilizing the MC-PEM algorithm in parallelized S-ADAPT version 1.56.. In the PD model, active GLP-1 production was stimulated by gastrointestinal intake of nutrients. Active GLP-1 was primarily metabolized by DPP-4 and an additional non-saturable pathway. Increased plasma glucose stimulated secretion of insulin which stimulated utilization of glucose. Active GLP-1 stimulated both glucose-dependent insulin secretion and insulin-dependent glucose utilization. Complete inhibition of DPP-4 resulted in an approximately 2.5-fold increase of active GLP-1 half-life.. The effects of vildagliptin in patients with type 2 diabetes on several PD endpoints were successfully described by the proposed model. The mechanisms of vildagliptin on glycaemic control could be evaluated from a variety of aspects such as effects of DPP-4 on GLP-1, effects of GLP-1 on insulin secretion and effects on hepatic and peripheral insulin sensitivity. The present model can be used to predict the effects of other dosage regimens of vildagliptin on DPP-4 inhibition, active GLP-1, glucose and insulin concentrations, or can be modified and applied to other incretin-related anti-diabetes therapies. Topics: Adamantane; Administration, Oral; Adult; Blood Glucose; Cross-Over Studies; Diabetes Mellitus, Type 2; Dipeptidyl-Peptidase IV Inhibitors; Dose-Response Relationship, Drug; Double-Blind Method; Enzyme-Linked Immunosorbent Assay; Female; Glucagon-Like Peptide 1; Humans; Insulin; Male; Middle Aged; Models, Biological; Nitriles; Pyrrolidines; Vildagliptin | 2012 |
Effect of the once-daily human GLP-1 analogue liraglutide on appetite, energy intake, energy expenditure and gastric emptying in type 2 diabetes.
Liraglutide reduces bodyweight in patients with type 2 diabetes mellitus (T2DM). This study aimed to investigate the mechanisms underlying this effect.. The comparative effects of liraglutide, glimepiride and placebo on energy intake, appetite, nausea, gastric emptying, antral distension, bodyweight, gastrointestinal hormones, fasting plasma glucose and resting energy expenditure (REE), were assessed in subjects with T2DM randomised to treatment A (liraglutide-placebo), B (placebo-glimepiride) or C (glimepiride-liraglutide). Assessments were performed at the end of each 4-week treatment period.. Energy intake was less (NS) with liraglutide vs placebo and glimepiride, and 24-h REE was higher (NS) with liraglutide vs placebo and glimepiride. Fasting hunger was less (p=0.01) with liraglutide vs placebo and glimepiride, and meal duration was shorter with liraglutide (p=0.002) vs placebo. Paracetamol AUC(0-60 min) and C(max) were less (p<0.01) and fasting peptide YY was lower (p ≤ 0.001) after liraglutide vs placebo and glimepiride. Bodyweight reductions of 1.3 and 2.0 kg were observed with liraglutide vs placebo and glimepiride (p<0.001). There were no differences on antral distension, nausea, or other gastro-intestinal hormones.. Liraglutide caused decreased gastric emptying and increased reduction in bodyweight. The mechanisms of the liraglutide-induced weight-loss may involve a combined effect on energy intake and energy expenditure. Topics: Adolescent; Adult; Aged; Appetite; Australia; Blood Glucose; Body Weight; Diabetes Mellitus, Type 2; Energy Intake; Energy Metabolism; Female; Gastric Emptying; Glucagon-Like Peptide 1; Humans; Hypoglycemic Agents; Liraglutide; Male; Middle Aged; Obesity; Sulfonylurea Compounds; Young Adult | 2012 |
Effects of meal timing relative to dosing on the pharmacokinetics and pharmacodynamics of vildagliptin in Japanese patients with Type 2 diabetes.
To assess the effects of meal timing on the pharmacokinetics and pharmacodynamics of the dipeptidyl peptidase IV (DPP-4) inhibitor vildagliptin in Japanese patients with Type 2 diabetes.. In this open-label, single-center crossover study, 12 Japanese patients with Type 2 diabetes were randomized to twice-daily vildagliptin 50 mg, administered 30 min before or immediately before breakfast and dinner for 7 days. After a 7-day washout period, patients received the other regimen. Blood samples were collected for the determination of vildagliptin, DPP-4, glucagon-like peptide-1 (GLP-1) and glucose.. Vildagliptin absorption appeared slower when administered 30 min before rather than immediately before meals (tmax absolute range: 1.00 - 2.00 h vs. 0.33 - 1.58 h). Vildagliptin Cmax and AUC0-8 h were essentially the same irrespective of meal timing (geometric mean ratio: Cmax 1.08 (90% CI; 0.92 - 1.26); AUC0-8 h 0.97 (90% CI; 0.91 - 1.05)). Meal timing did not affect pharmacodynamics; complete DPP-4 inhibition (> 90%) was sustained for 8 h post-dose, and plasma active glucagon-like peptide-1 levels increased 2 - 3-fold from baseline. Fasting plasma glucose (FPG) and postprandial plasma glucose (PPPG) reductions from baseline did not differ significantly with meal timing (30 min before vs. immediately before: FPG, -8.9 vs. -5.8 mg/dl; adjusted AUE0-4 h, -67.0 vs. -51.0 mg×h/dl). Vildagliptin was well tolerated.. Dosing 30 min or immediately before meals did not affect vildagliptin pharmacokinetics or pharmacodynamics in Japanese patients with Type 2 diabetes. Topics: Adamantane; Adult; Analysis of Variance; Area Under Curve; Asian People; Biomarkers; Blood Glucose; Cross-Over Studies; Diabetes Mellitus, Type 2; Dipeptidyl-Peptidase IV Inhibitors; Drug Administration Schedule; Drug Monitoring; Eating; Feeding Behavior; Female; Food-Drug Interactions; Glucagon-Like Peptide 1; Humans; Intestinal Absorption; Japan; Male; Middle Aged; Nitriles; Postprandial Period; Pyrrolidines; Treatment Outcome; Vildagliptin | 2012 |
Acute and long-term effects of Roux-en-Y gastric bypass on glucose metabolism in subjects with Type 2 diabetes and normal glucose tolerance.
Our aim was to study the potential mechanisms responsible for the improvement in glucose control in Type 2 diabetes (T2D) within days after Roux-en-Y gastric bypass (RYGB). Thirteen obese subjects with T2D and twelve matched subjects with normal glucose tolerance (NGT) were examined during a liquid meal before (Pre), 1 wk, 3 mo, and 1 yr after RYGB. Glucose, insulin, C-peptide, glucagon-like peptide-1 (GLP-1), glucose-dependent-insulinotropic polypeptide (GIP), and glucagon concentrations were measured. Insulin resistance (HOMA-IR), β-cell glucose sensitivity (β-GS), and disposition index (D(β-GS): β-GS × 1/HOMA-IR) were calculated. Within the first week after RYGB, fasting glucose [T2D Pre: 8.8 ± 2.3, 1 wk: 7.0 ± 1.2 (P < 0.001)], and insulin concentrations decreased significantly in both groups. At 129 min, glucose concentrations decreased in T2D [Pre: 11.4 ± 3, 1 wk: 8.2 ± 2 (P = 0.003)] but not in NGT. HOMA-IR decreased by 50% in both groups. β-GS increased in T2D [Pre: 1.03 ± 0.49, 1 wk: 1.70 ± 1.2, (P = 0.012)] but did not change in NGT. The increase in DI(β-GS) was 3-fold in T2D and 1.5-fold in NGT. After RYGB, glucagon secretion was increased in response to the meal. GIP secretion was unchanged, while GLP-1 secretion increased more than 10-fold in both groups. The changes induced by RYGB were sustained or further enhanced 3 mo and 1 yr after surgery. Improvement in glycemic control in T2D after RYGB occurs within days after surgery and is associated with increased insulin sensitivity and improved β-cell function, the latter of which may be explained by dramatic increases in GLP-1 secretion. Topics: Adult; Body Mass Index; C-Peptide; Diabetes Mellitus, Type 2; Female; Follow-Up Studies; Gastric Bypass; Glucagon; Glucagon-Like Peptide 1; Glucose; Humans; Hyperglycemia; Insulin Resistance; Insulin-Secreting Cells; Male; Middle Aged; Obesity; Obesity, Morbid; Postprandial Period; Time Factors | 2012 |
Sequential intensification of metformin treatment in type 2 diabetes with liraglutide followed by randomized addition of basal insulin prompted by A1C targets.
We evaluated the addition of liraglutide to metformin in type 2 diabetes followed by intensification with basal insulin (detemir) if glycated hemoglobin (A1C) ≥7%.. In 988 participants from North America and Europe uncontrolled on metformin ± sulfonylurea, sulfonylurea was discontinued and liraglutide 1.8 mg/day added for 12 weeks (run-in). Subsequently, those with A1C ≥7% were randomized 1:1 to 26 weeks' open-label addition of insulin detemir to metformin + liraglutide (n = 162) or continuation without insulin detemir (n = 161). Patients achieving A1C <7% continued unchanged treatment (observational arm). The primary end point was A1C change between randomized groups.. Of 821 participants completing the run-in, 61% (n = 498) achieved A1C <7% (mean change -1.3% from 7.7% at start), whereas 39% (n = 323) did not (-0.6% from 8.3% at start). During run-in, 167 of 988 (17%) withdrew; 46% of these due to gastrointestinal adverse events. At week 26, A1C decreased further, by 0.5% (from 7.6% at randomization) with insulin detemir (n = 162) versus 0.02% increase without insulin detemir (n = 157) to 7.1 and 7.5%, respectively (estimated treatment difference -0.52 [95% CI -0.68 to -0.36]; P < 0.0001). Forty-three percent of participants with insulin detemir versus 17% without reached A1C <7%. Mean weight decreased by 3.5 kg during run-in, then by 0.16 kg with insulin detemir or 0.95 kg without insulin detemir. In the randomized phase, no major hypoglycemia occurred and minor hypoglycemia rates were 0.286 and 0.029 events per participant-year with and without insulin detemir (9.2 vs. 1.3%).. Supplementation of metformin with liraglutide and then insulin detemir was well tolerated in the majority of patients, with good glycemic control, sustained weight loss, and very low hypoglycemia rates. Topics: Adolescent; Adult; Aged; Aged, 80 and over; Blood Glucose; Diabetes Mellitus, Type 2; Female; Glucagon-Like Peptide 1; Glycated Hemoglobin; Humans; Hypoglycemic Agents; Insulin Detemir; Insulin, Long-Acting; Liraglutide; Male; Metformin; Middle Aged | 2012 |
Metabolic surgery for non-obese type 2 diabetes: incretins, adipocytokines, and insulin secretion/resistance changes in a 1-year interventional clinical controlled study.
To compare duodenal-jejunal bypass (DJB) with standard medical care in nonobese patients with type 2 diabetes and evaluate surgically induced endocrine and metabolic changes.. Eighteen patients submitted to a DJB procedure met the following criteria: overweight, diabetes diagnosis less than 15 years, current insulin treatment, residual β-cell function, and absence of autoimmunity. Patients who refused surgical treatment received standard medical care (control group). At baseline, 3, 6, and 12 months after surgery, insulin sensitivity and production of glucagon-like peptide-1 and glucose-insulinotropic polypeptide were assessed during a meal tolerance test. Fasting adipocytokines and dipeptidyl-peptidase-4 concentrations were measured.. The mean age of the patients was 50 (5) years, time of diagnosis: 9 (2) years, time of insulin usage: 6 (5) months, fasting glucose: 9.9 (2.5) mmol/dL, and HbA1c (glycosylated hemoglobin) level: 8.9% (1.2%). Duodenal-jejunal bypass group showed greater reductions in fasting glucose (22% vs 6% in control group, P < 0.05) and daily insulin requirement (93% vs 15%, P < 0.01). Twelve patients from DJB group stopped using insulin and showed improvements in insulin sensitivity and β-cell function (P < 0.01), and reductions in glucose-insulinotropic polypeptide levels (P < 0.001), glucagon during the first 30 minutes after meal (P < 0.05), and leptin levels (P < 0.05). Dipeptidyl-peptidase-4 levels increased after surgery (P < 0.01), but glucagon-like peptide-1 levels did not change.. Duodenal-jejunal bypass improved insulin sensitivity and β-cell function and reduced glucose-insulinotropic polypeptide, leptin, and glucagon production. Hence, DJB resulted in better glycemic control and reduction in insulin requirement but DJB did not result in remission of diabetes. Topics: Blood Glucose; Diabetes Mellitus, Type 2; Digestive System Surgical Procedures; Dipeptidyl Peptidase 4; Duodenum; Gastric Inhibitory Polypeptide; Glucagon-Like Peptide 1; Homeostasis; Humans; Incretins; Insulin Resistance; Jejunum; Middle Aged | 2012 |
Mechanisms for the antihyperglycemic effect of sitagliptin in patients with type 2 diabetes.
Dipeptidyl peptidase IV (DPP-4) inhibitors improve glycemic control in patients with type 2 diabetes. The underlying mechanisms (incretin effect, β-cell function, endogenous glucose production) are not well known.. The aim of the study was to examine mechanisms of the antihyperglycemic effect of DPP-4 inhibitors.. We administered a mixed meal with glucose tracers ([6,6-(2)H(2)]-glucose infused, [1-(2)H]-glucose ingested), and on a separate day, a glucose infusion matched the glucose responses to the meal (isoglycemic test) in 50 type 2 diabetes patients (hemoglobin A(1c) = 7.4 ± 0.8%) and seven controls; 47 diabetic completers were restudied after 6 wk. Glucose fluxes were calculated, and β-cell function was assessed by mathematical modeling. The incretin effect was calculated as the ratio of oral to iv insulin secretion.. We conducted a 6-wk, double-blind, randomized treatment with sitagliptin (100 mg/d; n = 25) or placebo (n = 22).. Relative to placebo, meal-induced changes in fasting glucose and glucose area under the curve (AUC) were greater with sitagliptin, in parallel with a lower appearance of oral glucose [difference (post-pre) AUC = -353 ± 915 vs. +146 ± 601 μmol · kg(-1) · 5 h] and greater suppression of endogenous glucose production. Insulin sensitivity improved 10%, whereas total insulin secretion was unchanged. During the meal, β-cell glucose sensitivity improved (+19[29] vs. 5[21] pmol · min(-1) · m(-2) · mm(-1); median [interquartile range]) and glucagon AUC decreased (19.6 ± 7.5 to 17.3 ± 7.1 ng · ml(-1) · 5 h), whereas intact glucose-dependent insulinotropic polypeptide and glucagon-like peptide-1 AUC increased with sitagliptin vs. placebo. The incretin effect was unchanged because sitagliptin increased β-cell glucose sensitivity also during the isoglycemic test.. Chronic sitagliptin treatment improves glycemic control by lowering the appearance of oral glucose, postprandial endogenous glucose release, and glucagon response, and by improving insulin sensitivity and β-cell glucose sensing in response to both oral and iv glucose. Topics: Adult; Aged; Blood Glucose; Diabetes Mellitus, Type 2; Double-Blind Method; Female; Glucagon; Glucagon-Like Peptide 1; Humans; Hypoglycemic Agents; Insulin-Secreting Cells; Male; Middle Aged; Pyrazines; Sitagliptin Phosphate; Triazoles | 2012 |
LX4211, a dual SGLT1/SGLT2 inhibitor, improved glycemic control in patients with type 2 diabetes in a randomized, placebo-controlled trial.
Thirty-six patients with type 2 diabetes mellitus (T2DM) were randomized 1:1:1 to receive a once-daily oral dose of placebo or 150 or 300 mg of the dual SGLT1/SGLT2 inhibitor LX4211 for 28 days. Relative to placebo, LX4211 enhanced urinary glucose excretion by inhibiting SGLT2-mediated renal glucose reabsorption; markedly and significantly improved multiple measures of glycemic control, including fasting plasma glucose, oral glucose tolerance, and HbA(1c); and significantly lowered serum triglycerides. LX4211 also mediated trends for lower weight, lower blood pressure, and higher glucagon-like peptide-1 levels. In a follow-up single-dose study in 12 patients with T2DM, LX4211 (300 mg) significantly increased glucagon-like peptide-1 and peptide YY levels relative to pretreatment values, probably by delaying SGLT1-mediated intestinal glucose absorption. In both studies, LX4211 was well tolerated without evidence of increased gastrointestinal side effects. These data support further study of LX4211-mediated dual SGLT1/SGLT2 inhibition as a novel mechanism of action in the treatment of T2DM. Topics: Administration, Oral; Adult; Blood Glucose; Diabetes Mellitus, Type 2; Dose-Response Relationship, Drug; Female; Glucagon-Like Peptide 1; Glucose Tolerance Test; Glycated Hemoglobin; Glycosides; Humans; Hypoglycemic Agents; Intestinal Absorption; Male; Middle Aged; Peptide YY; Sodium-Glucose Transporter 1; Sodium-Glucose Transporter 2 Inhibitors; Triglycerides | 2012 |
Sitagliptin exerts an antinflammatory action.
Sitagliptin is an inhibitor of the enzyme dipeptidyl peptidase-IV (DPP-IV), which degrades the incretins, glucagon-like peptide-1 and glucose-dependent insulinotropic polypeptide, and thus, sitagliptin increases their bioavailability. The stimulation of insulin and the suppression of glucagon secretion that follow exert a glucose lowering effect and hence its use as an antidiabetic drug. Because DPP-IV is expressed as CD26 on cell membranes and because CD26 mediates proinflammatory signals, we hypothesized that sitagliptin may exert an antiinflammatory effect.. Twenty-two patients with type 2 diabetes were randomized to receive either 100 mg daily of sitagliptin or placebo for 12 wk. Fasting blood samples were obtained at baseline and at 2, 4, and 6 hours after a single dose of sitagliptin and at 2, 4, 8, and 12 wk of treatment.. Glycosylated hemoglobin fell significantly from 7.6 ± 0.4 to 6.9 ± 3% in patients treated with sitagliptin. Fasting glucagon-like peptide-1 concentrations increased significantly, whereas the mRNA expression in mononuclear cell of CD26, the proinflammatory cytokine, TNFα, the receptor for endotoxin, Toll-like receptor (TLR)-4, TLR-2, and proinflammatory kinases, c-Jun N-terminal kinase-1 and inhibitory-κB kinase (IKKβ), and that of the chemokine receptor CCR-2 fell significantly after 12 wk of sitagliptin. TLR-2, IKKβ, CCR-2, and CD26 expression and nuclear factor-κB binding also fell after a single dose of sitagliptin. There was a fall in protein expression of c-Jun N-terminal kinase-1, IKKβ, and TLR-4 and in plasma concentrations of C-reactive protein, IL-6, and free fatty acids after 12 wk of sitagliptin.. These effects are consistent with a potent and rapid antiinflammatory effect of sitagliptin and may potentially contribute to the inhibition of atherosclerosis. The suppression of CD26 expression suggests that sitagliptin may inhibit the synthesis of DPP-IV in addition to inhibiting its action. Topics: Adult; Aged; Anti-Inflammatory Agents, Non-Steroidal; Blood Glucose; Blotting, Western; C-Reactive Protein; Cell Separation; Diabetes Mellitus, Type 2; Dipeptidyl Peptidase 4; Dipeptidyl-Peptidase IV Inhibitors; Double-Blind Method; Female; Glucagon-Like Peptide 1; Glycated Hemoglobin; Humans; I-kappa B Kinase; Interleukin-6; Male; MAP Kinase Kinase 4; Middle Aged; Monocytes; Prospective Studies; Pyrazines; Receptors, CCR2; Sitagliptin Phosphate; Toll-Like Receptor 2; Toll-Like Receptor 4; Triazoles; Tumor Necrosis Factor-alpha | 2012 |
Safety, pharmacokinetics and pharmacodynamics of multiple-ascending doses of the novel glucokinase activator AZD1656 in patients with type 2 diabetes mellitus.
To assess the safety, pharmacokinetics and pharmacodynamics of multiple-ascending doses of the novel glucokinase activator AZD1656 in patients with type 2 diabetes mellitus (T2DM).. This randomized, single-blind, placebo-controlled, monotherapy study was carried out in two parts. In part A, 32 patients received AZD1656 (7, 20, 40 or 80 mg) twice daily or placebo for 8 days in hospital. In part B, another 20 patients received, as outpatients, individually titrated AZD1656 15-45 mg twice daily or placebo for 28 days. Safety, pharmacokinetics and pharmacodynamic variables were evaluated.. AZD1656 was generally well tolerated. Pharmacokinetics of AZD1656 were virtually dose- and time-independent. AZD1656 was rapidly absorbed and eliminated. An active metabolite was formed which had a longer half-life than AZD1656, but showed ∼15% of the area under the plasma concentration versus time curve from 0 to 24 h compared with that of AZD1656. Renal excretion of AZD1656 and the metabolite was low. In part A, fasting plasma glucose (FPG) was reduced by up to 21% and mean 24-h plasma glucose was reduced by up to 24% with AZD1656 versus placebo, depending on dose. No dose-related changes in serum insulin or C-peptide were observed with AZD1656 at the end of treatment. Results in part B confirmed the glucose-lowering effect of AZD1656 versus placebo.. AZD1656 was well tolerated with predictable pharmacokinetics in patients with T2DM. Dose-dependent reductions in plasma glucose were observed. Topics: Adult; Azetidines; Blood Glucose; Diabetes Mellitus, Type 2; Dose-Response Relationship, Drug; Female; Gastric Inhibitory Polypeptide; Glucagon-Like Peptide 1; Glucokinase; Glycated Hemoglobin; Humans; Hypoglycemic Agents; Incretins; Insulin; Male; Middle Aged; Peptide Fragments; Pyrazines; Single-Blind Method; Treatment Outcome | 2012 |
Monotherapy with the once-weekly GLP-1 analogue dulaglutide for 12 weeks in patients with Type 2 diabetes: dose-dependent effects on glycaemic control in a randomized, double-blind, placebo-controlled study.
Evaluate dose-dependent effects of once-weekly dulaglutide, a glucagon-like peptide-1 analogue, on glycaemic control in patients with Type 2 diabetes treated with lifestyle measures with or without previous metformin.. This 12-week, double-blind, placebo-controlled, dose-response trial randomized 167 patients who were anti-hyperglycaemic medication-naïve or had discontinued metformin monotherapy [mean baseline HbA(1c) 59 ± 8 to 61 ± 8 mmol/mol (7.6 ± 0.7 to 7.8 ± 0.8%)] to once-weekly injections of placebo or dulaglutide (0.1, 0.5, 1.0 or 1.5 mg).. A significant dose-dependent reduction in HbA(1c) (least squares mean ± SE) was observed across doses (P < 0.001). HbA(1c) reductions in the 0.5, 1.0 and 1.5 mg dulaglutide groups were greater than in the placebo group [-10 ± 1, -11 ± 1 and -11 ± 1 vs. 0 ± 1 mmol/mol (-0.9 ± 0.1, -1.0 ± 0.1 and -1.0 ± 0.1 vs. 0.0 ± 0.1%), respectively, all P < 0.001]. Dose-dependent reductions in fasting plasma glucose were also observed [least squares mean difference (95% CI) ranging from -0.43 (-1.06 to 0.19) mmol/l for dulaglutide 0.1 mg to -1.87 (-2.56 to -1.19) mmol/l for dulaglutide 1.5 mg, P < 0.001]. Dose-dependent weight loss was demonstrated across doses (P = 0.009), but none of the groups were different from placebo. The most common adverse events were nausea and diarrhoea.. The observed dulaglutide dose-dependent reduction in HbA(1c) and its acceptable safety profile support further clinical development for treatment of Type 2 diabetes. Topics: Blood Glucose; Diabetes Mellitus, Type 2; Dose-Response Relationship, Drug; Double-Blind Method; Fasting; Female; Glucagon-Like Peptide 1; Glucagon-Like Peptides; Humans; Hypoglycemic Agents; Immunoglobulin Fc Fragments; Male; Middle Aged; Recombinant Fusion Proteins | 2012 |
Efficacy and safety of switching from the DPP-4 inhibitor sitagliptin to the human GLP-1 analog liraglutide after 52 weeks in metformin-treated patients with type 2 diabetes: a randomized, open-label trial.
To assess the efficacy and safety of switching from sitagliptin to liraglutide in metformin-treated adults with type 2 diabetes.. In an open-label trial, participants randomized to receive either liraglutide (1.2 or 1.8 mg/day) or sitagliptin (100 mg/day), each added to metformin, continued treatment for 52 weeks. In a 26-week extension, sitagliptin-treated participants were randomly allocated to receive instead liraglutide at either 1.2 or 1.8 mg/day, while participants originally randomized to receive liraglutide continued unchanged.. Although 52 weeks of sitagliptin changed glycosylated hemoglobin (HbA(1c)) by -0.9% from baseline, additional decreases occurred after switching to liraglutide (1.2 mg/day, -0.2%, P = 0.006; 1.8 mg/day, -0.5%, P = 0.0001). Conversion to liraglutide was associated with reductions in fasting plasma glucose (FPG) (1.2 mg/day, -0.8 mmol/L, P = 0.0004; 1.8 mg/day, -1.4 mmol/L, P < 0.0001) and body weight (1.2 mg/day, -1.6 kg; 1.8 mg/day, -2.5 kg; both P < 0.0001) and with an increased proportion of patients reaching HbA(1c) <7% (from ∼30% to ∼50%). Overall treatment satisfaction, assessed by the Diabetes Treatment Satisfaction Questionnaire, improved after switching to liraglutide (pooled 1.2 and 1.8 mg/day, 1.3; P = 0.0189). After switching, mostly transient nausea occurred in 21% of participants, and minor hypoglycemia remained low (3-4% of participants). Continuing liraglutide treatment at 1.2 mg/day and 1.8 mg/day for 78 weeks reduced HbA(1c) (baseline 8.3 and 8.4%, respectively) by -0.9 and -1.3%, respectively; FPG by -1.3 and -1.7 mmol/L, respectively; and weight by -2.6 and -3.1 kg, respectively, with 9-10% of participants reporting minor hypoglycemia.. Glycemic control, weight, and treatment satisfaction improved after switching from sitagliptin to liraglutide, albeit with a transient increase in gastrointestinal reactions. Topics: Adult; Blood Glucose; Body Weight; Diabetes Mellitus, Type 2; Dipeptidyl-Peptidase IV Inhibitors; Glucagon-Like Peptide 1; Glycated Hemoglobin; Humans; Liraglutide; Metformin; Nausea; Patient Satisfaction; Pyrazines; Sitagliptin Phosphate; Treatment Outcome; Triazoles | 2012 |
Efficacy and safety profile of exenatide once weekly compared with insulin once daily in Japanese patients with type 2 diabetes treated with oral antidiabetes drug(s): results from a 26-week, randomized, open-label, parallel-group, multicenter, noninferio
Exenatide once weekly (QW) is an extended-release formulation of exenatide, a glucagon-like peptide-1 receptor agonist that reportedly improves glycemic control in patients with type 2 diabetes.. The goal of this study was to test the hypothesis that exenatide QW is noninferior to insulin glargine, as measured by change in glycosylated hemoglobin (HbA(1c)) from baseline to end point (week 26 [primary end point]) in Japanese patients with type 2 diabetes who have inadequate glycemic control with oral antidiabetes drugs.. In this open-label, parallel-group, multicenter, noninferiority registration study, patients were randomized (1:1) to add exenatide QW (2 mg) or once-daily insulin glargine (starting dose, 4 U) to their current oral antidiabetes drug treatment. The primary analysis was change in HbA(1c) from baseline to end point, evaluated by using a last-observation-carried-forward ANCOVA model, with a predefined noninferiority margin of 0.4%. Secondary analyses (a priori) included analysis of superiority for between-group comparisons of change in weight and the proportion of patients reaching HbA(1c) target levels of ≤7.0% or ≤6.5%.. The baseline characteristics of the exenatide QW (215 patients) and insulin glargine (212 patients) treatment groups were similar: mean (SD) age, 57 (10) years and 56 (11) years, respectively; 66.0% and 69.8% male; mean HbA(1c), 8.5% (0.82%) and 8.5% (0.79%); and mean weight, 69.9 (13.2) kg and 71.0 (13.9) kg. Exenatide QW was statistically noninferior to insulin glargine for the change in HbA(1c) from baseline to end point (least squares mean difference, -0.43% [95% CI, -0.59 to -0.26]; P < 0.001), with the 95% CI upper limit less than the predefined noninferiority margin (0.4%). A significantly greater proportion of patients receiving exenatide QW compared with insulin glargine achieved HbA(1c) target levels of ≤7.0% (89 of 211 [42.2%] vs 44 of 210 [21.0%]) or ≤6.5% (44 of 214 [20.6%] vs 9 of 212 [4.2%]) at end point (P < 0.001 for both). Patient weight was reduced with exenatide QW compared with insulin glargine at end point (least squares mean difference, -2.01 kg [95% CI, -2.46 to -1.56]; P < 0.001). Exenatide QW was well tolerated, with a lower risk of hypoglycemia compared with insulin glargine but a higher incidence of injection-site induration.. Exenatide QW was statistically noninferior to insulin glargine for the change in HbA(1c) from baseline to end point; these results suggest that exenatide QW may provide an effective alternative treatment for Japanese patients who require additional therapy to control their diabetes. ClinicalTrials.gov identifier: NCT00935532. Topics: Administration, Oral; Aged; Blood Glucose; Body Weight; Delayed-Action Preparations; Diabetes Mellitus, Type 2; Exenatide; Female; Glucagon-Like Peptide 1; Glycated Hemoglobin; Humans; Hypoglycemia; Hypoglycemic Agents; Insulin Glargine; Insulin, Long-Acting; Japan; Least-Squares Analysis; Male; Middle Aged; Peptides; Venoms | 2012 |
Lower ghrelin levels and exaggerated postprandial peptide-YY, glucagon-like peptide-1, and insulin responses, after gastric fundus resection, in patients undergoing Roux-en-Y gastric bypass: a randomized clinical trial.
Laparoscopic Roux-en Y-Gastric bypass (LRYGBP) is the commonest available option for the surgical treatment of morbid obesity. Weight loss following bariatric surgery has been linked to changes of gastrointestinal peptides, shown to be implicated also in metabolic effects and appetite control. The purpose of this study was to evaluate whether gastric fundus resection in patients undergoing LRYGBP enhances the efficacy of the procedure in terms of weight loss, glucose levels, and hormonal secretion.. Twelve patients underwent LRYGBP and 12 patients LRYGBP plus gastric fundus resection (LRYGBP+FR). All patients were evaluated before and at 3, 6, and 12 months postoperatively. Blood samples were collected after an overnight fast and 30, 60, and 120 min after a standard 300-kcal mixed meal.. Body weight and body mass index decreased markedly and comparably after both procedures. Fasting ghrelin decreased 3 months after LRYGBP, but increased at 12 months to levels higher than baseline while after LRYGBP+FR was markedly and persistently decreased. Postprandial GLP-1, PYY, and insulin responses were enhanced more and postprandial glucose levels were lower after LRYGBP+FR compared to LRYGBP. Postoperatively, ghrelin changes correlated negatively with GLP-1 changes.. Resection of the gastric fundus in patients undergoing LRYGBP was associated with persistently lower fasting ghrelin levels; higher postprandial PYY, GLP-1, and insulin responses; and lower postprandial glucose levels compared to LRYGBP. These findings suggest that fundus resection in the setting of LRYGBP may be more effective than RYGBP for the management of morbid obesity and diabetes type 2. Topics: Biomarkers; Body Mass Index; Diabetes Mellitus, Type 2; Fasting; Female; Gastric Bypass; Gastric Fundus; Ghrelin; Glucagon-Like Peptide 1; Humans; Male; Obesity, Morbid; Peptide YY; Postprandial Period; Weight Loss | 2012 |
Glucagon-like peptide-1 decreases intracerebral glucose content by activating hexokinase and changing glucose clearance during hyperglycemia.
Type 2 diabetes and hyperglycemia with the resulting increase of glucose concentrations in the brain impair the outcome of ischemic stroke, and may increase the risk of developing Alzheimer's disease (AD). Reports indicate that glucagon-like peptide-1 (GLP-1) may be neuroprotective in models of AD and stroke: Although the mechanism is unclear, glucose homeostasis appears to be important. We conducted a randomized, double-blinded, placebo-controlled crossover study in nine healthy males. Positron emission tomography was used to determine the effect of GLP-1 on cerebral glucose transport and metabolism during a hyperglycemic clamp with (18)fluoro-deoxy-glucose as tracer. Glucagon-like peptide-1 lowered brain glucose (P=0.023) in all regions. The cerebral metabolic rate for glucose was increased everywhere (P=0.039) but not to the same extent in all regions (P=0.022). The unidirectional glucose transfer across the blood-brain barrier remained unchanged (P=0.099) in all regions, while the unidirectional clearance and the phosphorylation rate increased (P=0.013 and 0.017), leading to increased net clearance of the glucose tracer (P=0.006). We show that GLP-1 plays a role in a regulatory mechanism involved in the actions of GLUT1 and glucose metabolism: GLP-1 ensures less fluctuation of brain glucose levels in response to alterations in plasma glucose, which may prove to be neuroprotective during hyperglycemia. Topics: Adult; Alzheimer Disease; Biological Transport; Blood-Brain Barrier; Brain Chemistry; Brain Ischemia; Cross-Over Studies; Diabetes Mellitus, Type 2; Double-Blind Method; Fluorodeoxyglucose F18; Glucagon-Like Peptide 1; Glucose; Glucose Clamp Technique; Glucose Transporter Type 1; Hexokinase; Humans; Hyperglycemia; Male; Positron-Emission Tomography; Radiography; Radiopharmaceuticals; Stroke | 2012 |
Efficacy and safety comparison between liraglutide as add-on therapy to insulin and insulin dose-increase in Chinese subjects with poorly controlled type 2 diabetes and abdominal obesity.
To assess the efficacy and safety of adding liraglutide to established insulin therapy in poorly controlled Chinese subjects with type 2 diabetes and abdominal obesity compared with increasing insulin dose.. A 12-week, randomized, parallel-group study was carried out. A total of 84 patients completed the trial who had been randomly assigned to either the liraglutide-added group or the insulin-increasing group while continuing current insulin based treatment. Insulin dose was reduced by 0-30% upon the initiation of liraglutide. Insulin doses were subsequently adjusted to optimized glycemic control. Glycosylated hemoglobin (HbA1c) values, blood glucose, total daily insulin dose, body weight, waist circumference, and the number of hypoglycemic events and adverse events were evaluated.. At the end of study, the mean reduction in HbA1c between the liraglutide-added group and the insulin-increasing group was not significantly different (1.9% vs. 1.77%, p>0.05). However, the percentage of subjects reaching the composite endpoint of HbA1c ≤ 7.0% with no weight gain and no hypoglycemia, was significantly higher in the liraglutide-added group than in the insulin-increasing group (67% vs. 19%, p<0.001). Add-on liraglutide treatment significantly reduced mean body weight (5.62 kg, p<0.01), waist circumference (5.70 cm, p<0.01), body mass index (BMI) (1.93 kg/m2, p<0.01) and daily total insulin dose (dropped by 66%) during 12-week treatment period, while all of these significantly increased with insulin increasing treatment. Add-on liraglutide treated patients had lower rate of hypoglycemic events and greater insulin and oral antidiabetic drugs discontinuation. Gastrointestinal disorders were the most common adverse events in the liraglutide added treatment, but were transient.. Addition of liraglutide to abdominally obese, insulin-treated patients led to improvement in glycemic control similar to that achieved by increasing insulin dosage, but with a lower daily dose of insulin and fewer hypoglycemic events. Adding liraglutide to insulin also induced a significant reduction in body weight and waist circumference. Liraglutide combined with insulin may be the best treatment option for poorly controlled type 2 diabetes and abdominal obesity. Topics: Adult; Asian People; Biomarkers; Blood Glucose; China; Diabetes Mellitus, Type 2; Dose-Response Relationship, Drug; Drug Therapy, Combination; Female; Glucagon-Like Peptide 1; Glycated Hemoglobin; Humans; Hypoglycemia; Hypoglycemic Agents; Insulin; Liraglutide; Male; Middle Aged; Obesity, Abdominal; Time Factors; Treatment Outcome; Waist Circumference; Weight Gain | 2012 |
Dipeptidyl peptidase 4 inhibition may facilitate healing of chronic foot ulcers in patients with type 2 diabetes.
The pathophysiology of chronic diabetic ulcers is complex and still incompletely understood, both micro- and macroangiopathy strongly contribute to the development and delayed healing of diabetic wounds, through an impaired tissue feeding and response to ischemia. With adequate treatment, some ulcers may last only weeks; however, many ulcers are difficult to treat and may last months, in certain cases years; 19-35% of ulcers are reported as nonhealing. As no efficient therapy is available, it is a high priority to develop new strategies for treatment of this devastating complication. Because experimental and pathological studies suggest that incretin hormone glucagon-like peptide-1 may improves VEGF generation and promote the upregulation of HIF-1α through a reduction of oxidative stress, the study evaluated the effect of the augmentation of GLP-1, by inhibitors of the dipeptidyl peptidase-4, such as vildagliptin, on angiogenesis process and wound healing in diabetic chronic ulcers. Although elucidation of the pathophysiologic importance of these aspects awaits further confirmations, the present study evidences an additional aspect of how DPP-4 inhibition might contribute to improved ulcer outcome. Topics: Adamantane; Aged; Aged, 80 and over; Capillaries; Chronic Disease; Diabetes Mellitus, Type 2; Diabetic Foot; Dipeptidyl Peptidase 4; Dipeptidyl-Peptidase IV Inhibitors; Female; Gene Expression Regulation; Glucagon-Like Peptide 1; Humans; Hypoxia-Inducible Factor 1, alpha Subunit; Italy; Male; Middle Aged; Neovascularization, Physiologic; Nitriles; Oxidative Stress; Proteasome Endopeptidase Complex; Pyrrolidines; RNA, Messenger; Time Factors; Treatment Outcome; Vascular Endothelial Growth Factor A; Vildagliptin; Wound Healing | 2012 |
Application of adaptive design methodology in development of a long-acting glucagon-like peptide-1 analog (dulaglutide): statistical design and simulations.
Dulaglutide (dula, LY2189265), a long-acting glucagon-like peptide-1 analog, is being developed to treat type 2 diabetes mellitus.. To foster the development of dula, we designed a two-stage adaptive, dose-finding, inferentially seamless phase 2/3 study. The Bayesian theoretical framework is used to adaptively randomize patients in stage 1 to 7 dula doses and, at the decision point, to either stop for futility or to select up to 2 dula doses for stage 2. After dose selection, patients continue to be randomized to the selected dula doses or comparator arms. Data from patients assigned the selected doses will be pooled across both stages and analyzed with an analysis of covariance model, using baseline hemoglobin A1c and country as covariates. The operating characteristics of the trial were assessed by extensive simulation studies.. Simulations demonstrated that the adaptive design would identify the correct doses 88% of the time, compared to as low as 6% for a fixed-dose design (the latter value based on frequentist decision rules analogous to the Bayesian decision rules for adaptive design).. This article discusses the decision rules used to select the dula dose(s); the mathematical details of the adaptive algorithm-including a description of the clinical utility index used to mathematically quantify the desirability of a dose based on safety and efficacy measurements; and a description of the simulation process and results that quantify the operating characteristics of the design. Topics: Algorithms; Diabetes Mellitus, Type 2; Dose-Response Relationship, Drug; Double-Blind Method; Glucagon-Like Peptide 1; Glucagon-Like Peptides; Humans; Hypoglycemic Agents; Immunoglobulin Fc Fragments; Recombinant Fusion Proteins; Research Design | 2012 |
An adaptive, dose-finding, seamless phase 2/3 study of a long-acting glucagon-like peptide-1 analog (dulaglutide): trial design and baseline characteristics.
Dulaglutide (dula, LY2189265) is a once-weekly glucagon-like peptide-1 analog in development for the treatment of type 2 diabetes mellitus. An adaptive, dose-finding, inferentially seamless phase 2/3 study was designed to support the development of this novel diabetes therapeutic. The study is divided into two stages based on two randomization schemes: a Bayesian adaptive scheme (stage 1) and a fixed scheme (stage 2). Stage 1 of the trial employs an adaptive, dose-finding design to lead to a dula dose-selection decision or early study termination due to futility. If dose selection occurs, the study proceeds to stage 2 to allow continued evaluation of the selected dula doses. At completion, the entire study will serve as a confirmatory phase 3 trial. The final study design is discussed, along with specifics pertaining to the actual execution of this study and selected baseline characteristics of the participants. Topics: Bayes Theorem; Diabetes Mellitus, Type 2; Dose-Response Relationship, Drug; Double-Blind Method; Female; Glucagon-Like Peptide 1; Glucagon-Like Peptides; Humans; Hypoglycemic Agents; Immunoglobulin Fc Fragments; Male; Middle Aged; Pyrazines; Recombinant Fusion Proteins; Research Design; Sitagliptin Phosphate; Triazoles | 2012 |
Addition of metformin to exogenous glucagon-like peptide-1 results in increased serum glucagon-like peptide-1 concentrations and greater glucose lowering in type 2 diabetes mellitus.
Glucagon-like peptide-1 (GLP-1) is an incretin hormone that lowers blood glucose after meals in type 2 diabetes mellitus. The therapeutic potential of GLP-1 in diabetes is limited by rapid inactivation by the enzyme dipeptidylpeptidase-4 (DPP-4). Metformin has been reported to inhibit DPP-4. Here we investigated the acute effects of metformin and GLP-1 alone or in combination on plasma DPP-4 activity, active GLP-1 concentrations, and glucose lowering in type 2 diabetes mellitus. Ten subjects with type 2 diabetes mellitus (8 male and 2 female; age, 68.7 ± 2.6 years [mean ± SEM]; body mass index, 29.6 ± 1.7 kg/m²; hemoglobin A(1c), 7.0% ± 0.1%) received 1 of 3 combinations after an overnight fast in a randomized crossover design: metformin 1 g orally plus subcutaneous injection saline (Metformin), GLP-1 (1.5 nmol/kg body weight subcutaneously) plus placebo tablet (GLP-1), or metformin 1 g plus GLP-1(Metformin + GLP-1). At 15 minutes, glucose was raised to 15 mmol/L by rapid intravenous infusion of glucose; and responses were assessed over the next 3 hours. This stimulus does not activate the enteroinsular axis and secretion of endogenous GLP-1, enabling the effect of exogenously administered GLP-1 to be examined. Mean area under curve (AUC) (0-180 minutes) plasma glucose responses were lowest after Metformin + GLP-1 (mean ± SEM, 1629 ± 90 mmol/[L min]) compared with GLP-1 (1885 ± 86 mmol/[L min], P < .002) and Metformin (2045 ± 115 mmol/[L min], P < .001). Mean AUC serum insulin responses were similar after either Metformin + GLP-1 (5426 ± 498 mU/[L min]) or GLP-1 (5655 ± 854 mU/[L min]) treatment, and both were higher than Metformin (3521 ± 410 mU/[L min]; P < .001 and P < .05, respectively). Mean AUC for plasma DPP-4 activity was lower after Metformin + GLP-1 (1505 ± 2 μmol/[mL min], P < .001) and Metformin (1508 ± 2 μmol/[mL min], P < .002) compared with GLP-1 (1587 ± 3 μmol/[mL min]). Mean AUC measures for plasma active GLP-1 concentrations were higher after Metformin + GLP-1 (820 x 10⁴ ± 51 x 10⁴ pmol/[L min]) compared with GLP-1 (484 x 10⁴ ± 31 x 10⁴ pmol/[L min], P < .001) and Metformin (419 × 10⁴ ± 34 x 10⁴ pmol/[L min], P < .001), respectively. In patients with type 2 diabetes mellitus, metformin inhibits DPP-4 activity and thus increases active GLP-1 concentrations after subcutaneous injection. In combination with GLP-1, metformin significantly lowers plasma glucose concentrations in type 2 diabetes mellitus subjects compared with GLP-1 alone, whe Topics: Aged; Blood Glucose; Cross-Over Studies; Diabetes Mellitus, Type 2; Dipeptidyl Peptidase 4; Female; Glucagon-Like Peptide 1; Humans; Hypoglycemic Agents; Male; Metformin | 2011 |
Liraglutide provides similar glycaemic control as glimepiride (both in combination with metformin) and reduces body weight and systolic blood pressure in Asian population with type 2 diabetes from China, South Korea and India: a 16-week, randomized, doubl
To assess and compare the efficacy and safety of liraglutide with those of glimepiride, both in combination with metformin for the treatment of type 2 diabetes in Asian population from China, South Korea and India.. A 16-week, randomized, double-blind, double-dummy, four-arm, active control trial was carried out. In total, 929 subjects with type 2 diabetes with a mean (±s.d.) age of 53.3 ± 9.5 years, HbA₁(c) of 8.6 ± 1.0% and body weight of 68.1 ± 11.7 kg were randomized (liraglutide 0.6, 1.2 or 1.8 mg once daily or glimepiride 4 mg once daily all in combination with metformin: 1 : 1 : 1 : 1). One subject withdrew immediately after randomization and before exposure.. HbA₁(c) was significantly reduced in all groups compared with baseline. Treatment with liraglutide 1.2 and 1.8 mg was non-inferior to glimepiride (mean HbA₁(c) reduction: 1.36% points, 1.45% points and 1.39% points, respectively). No significant difference was shown in the percentage of subjects reaching American Diabetes Association HbA₁(c) target <7% or American Association of Clinical Endocrinologists target ≤6.5% between liraglutide 1.2 and 1.8 mg and glimepiride. Liraglutide was associated with a 1.8-2.4 kg mean weight reduction, compared with a 0.1 kg mean weight gain with glimepiride. Liraglutide led to a significantly greater reduction in systolic blood pressure (SBP) compared with glimepiride. Two subjects in the glimepiride group reported major hypoglycaemia while none in the liraglutide groups. Liraglutide was associated with about 10-fold lower incidence of minor hypoglycaemia than glimepiride. Gastrointestinal disorders were the most common adverse events (AEs) for liraglutide, but were transient and resulted in few withdrawals.. In Asian subjects with type 2 diabetes, once-daily liraglutide led to improvement in glycaemic control similar to that with glimepiride but with less frequent major and minor hypoglycaemia. Liraglutide also induced a significant weight loss and reduced SBP and was generally well tolerated. The most frequently reported AE was transient nausea. The effect of liraglutide in this Asian population is comparable to the effects seen in Caucasian, African American and Hispanic populations in global liraglutide phase 3 trials. Topics: Adolescent; Adult; Aged; Aged, 80 and over; Asian People; Blood Pressure; China; Diabetes Mellitus, Type 2; Double-Blind Method; Drug Therapy, Combination; Female; Glucagon-Like Peptide 1; Humans; Hypoglycemic Agents; India; Liraglutide; Male; Metformin; Middle Aged; Republic of Korea; Sulfonylurea Compounds; Weight Loss; Young Adult | 2011 |
Effects of multiple doses of the DPP-IV inhibitor PF-734200 on the relationship between GLP-1 and glucose in subjects with type 2 diabetes mellitus.
A randomized, placebo-controlled study evaluated the effects multiple-doses (28 days) dipeptidyl peptidase-IV (DPP-IV) inhibitor PF-734200 on DPP-IV activity, glucose, glucagon-like peptide-1 (GLP-1), glucagon and insulin levels in 72 subjects with type 2 diabetes. The relationship between changes in active GLP-1 and glucose during a meal test appeared non-linear. Topics: Adult; Aged; Blood Glucose; Diabetes Mellitus, Type 2; Dipeptidyl-Peptidase IV Inhibitors; Double-Blind Method; Drug Administration Schedule; Female; Glucagon-Like Peptide 1; Humans; Male; Middle Aged | 2011 |
Additive hypoglycaemic effect of nateglinide and exogenous glucagon-like peptide-1 in type 2 diabetes.
We examined the postprandial glucose regulators nateglinide and GLP-1, separately and in combination, in people with type 2 diabetes. Nateglinide inhibited DPP-4 activity, reduced GLP-1 degradation and enhanced its insulinotropic and blood glucose lowering effect. Combining nateglinide and GLP-1 derivatives may effectively control postprandial glycaemia. Topics: Aged; Blood Glucose; Cross-Over Studies; Cyclohexanes; Diabetes Mellitus, Type 2; Drug Synergism; Drug Therapy, Combination; Female; Glucagon-Like Peptide 1; Humans; Hypoglycemic Agents; Male; Nateglinide; Phenylalanine; Postprandial Period; Treatment Outcome | 2011 |
Liraglutide, a once-daily human glucagon-like peptide 1 analogue, provides sustained improvements in glycaemic control and weight for 2 years as monotherapy compared with glimepiride in patients with type 2 diabetes.
Most treatments for type 2 diabetes fail over time, necessitating combination therapy. We investigated the safety, tolerability and efficacy of liraglutide monotherapy compared with glimepiride monotherapy over 2 years.. Participants were randomized to receive once-daily liraglutide 1.2 mg, liraglutide 1.8 mg or glimepiride 8 mg. Participants completing the 1-year randomized, double-blind, double-dummy period could continue open-label treatment for an additional year. Safety data were evaluated for the full population exposed to treatment, and efficacy data were evaluated for the full intention-to-treat (ITT) and 2-year completer populations. Outcome measures included change in glycosylated haemoglobin (HbA1c), fasting plasma glucose (FPG), body weight and frequency of nausea and hypoglycaemia.. For patients completing 2 years of therapy, HbA1c reductions were -0.6% with glimepiride versus -0.9% with liraglutide 1.2 mg (difference: -0.37, 95% CI: -0.71 to -0.02; p = 0.0376) and -1.1% with liraglutide 1.8 mg (difference: -0.55, 95% CI: -0.88 to -0.21; p = 0.0016). In the ITT population, HbA1c reductions were -0.3% with glimepiride versus -0.6% with liraglutide 1.2 mg (difference: -0.31, 95% CI: -0.54 to -0.08; p = 0.0076) and -0.9% with liraglutide 1.8 mg (difference: -0.60, 95% CI: -0.83 to -0.38; p < 0.0001). For both ITT and completer populations, liraglutide was more effective in reducing HbA1c, FPG and weight. Over 2 years, rates of minor hypoglycaemia [self-treated plasma glucose <3.1 mmol/l (<56 mg/dl)] were significantly lower with liraglutide 1.2 mg and 1.8 mg compared with glimepiride (p < 0.0001).. Liraglutide monotherapy for 2 years provides significant and sustained improvements in glycaemic control and body weight compared with glimepiride monotherapy, at a lower risk of hypoglycaemia. Topics: Blood Glucose; Body Weight; Diabetes Mellitus, Type 2; Double-Blind Method; Female; Glucagon-Like Peptide 1; Glycated Hemoglobin; Humans; Hypoglycemic Agents; Liraglutide; Male; Middle Aged; Sulfonylurea Compounds; Treatment Outcome | 2011 |
GLP-1 and calcitonin concentration in humans: lack of evidence of calcitonin release from sequential screening in over 5000 subjects with type 2 diabetes or nondiabetic obese subjects treated with the human GLP-1 analog, liraglutide.
Serum calcitonin (CT) is a well-accepted marker of C-cell proliferation, particularly in medullary thyroid carcinoma. Chronic glucagon-like peptide-1 (GLP-1) receptor agonist administration in rodents has been associated with increased serum CT levels and C-cell tumor formation. There are no longitudinal studies measuring CT in humans without medullary thyroid carcinoma or a family history of medullary thyroid carcinoma and no published studies on the effect of GLP-1 receptor agonists on human serum CT concentrations.. The aim of the study was to determine serum CT response over time to the GLP-1 receptor agonist liraglutide in subjects with type 2 diabetes mellitus or nondiabetic obese subjects.. Unstimulated serum CT concentrations were measured at 3-month intervals for no more than 2 yr in a series of trials in over 5000 subjects receiving liraglutide or control therapy.. Basal mean CT concentrations were at the low end of normal range in all treatment groups and remained low throughout the trials. At 2 yr, estimated geometric mean values were no greater than 1.0 ng/liter, well below upper normal ranges for males and females. Proportions of subjects whose CT levels increased above a clinically relevant cutoff of 20 ng/liter were very low in all groups. There was no consistent dose or time-dependent relationship and no consistent difference between treatment groups.. These data do not support an effect of GLP-1 receptor activation on serum CT levels in humans and suggest that findings previously reported in rodents may not apply to humans. However, the long-term consequences of GLP-1 receptor agonist treatment are a subject of further studies. Topics: Adult; Calcitonin; Diabetes Complications; Diabetes Mellitus, Type 2; Dose-Response Relationship, Drug; Female; Glucagon-Like Peptide 1; Glucagon-Like Peptide-1 Receptor; Humans; Hypoglycemic Agents; Liraglutide; Male; Middle Aged; Obesity; Receptors, Glucagon | 2011 |
A 5-week study of the pharmacokinetics and pharmacodynamics of LY2189265, a novel, long-acting glucagon-like peptide-1 analogue, in patients with type 2 diabetes.
To investigate the safety, tolerability, pharmacokinetics and pharmacodynamics of LY2189265 (LY), a novel, long-acting glucagen-like peptide-1 analogue, administered once weekly to subjects with type 2 diabetes.. This was a placebo-controlled, parallel-group, subject- and investigator-blind study of LY in subjects (N = 43) with type 2 diabetes mellitus controlled with diet and exercise alone or with a single oral antidiabetic medication. Subjects taking metformin or thiazolidinediones continued on their therapy. Subjects receiving sulfonylurea, acarbose, repaglinide or nateglinide were switched to metformin prior to enrollment. Subjects received five once-weekly doses of 0.05, 0.3, 1, 3, 5 or 8 mg. Effects on glucose, insulin and C-peptide concentrations were determined during fasting and following standard test meals. The pharmacokinetics of LY and its effects on HBA1c, glucagon, body weight, gastric emptying and safety parameters were assessed.. Once-weekly administration of LY significantly reduced (p < 0.01) fasting plasma glucose, 2-h post-test meal postprandial glucose and area under the curve (AUC) of glucose after test meals at doses ≥1 mg. These effects were seen after the first dose and were sustained through the weekly dosing cycle. Most doses produced statistically significant increases in insulin and C-peptide AUC when normalized for glucose AUC. Statistically significant reductions in HBA1c were observed for all dose groups except 0.3 mg. The most commonly reported adverse effects (AEs) were nausea (35 events), headache (20 events), vomiting (18 events) and diarrhoea (8 events).. LY showed improvement in fasting and postprandial glycaemic parameters when administered once weekly in subjects with type 2 diabetes. The pharmacokinetics and safety profiles also support further investigation of this novel agent. Topics: Adult; Aged; Area Under Curve; Blood Glucose; Cohort Studies; Diabetes Mellitus, Type 2; Dose-Response Relationship, Drug; Double-Blind Method; Drug Administration Schedule; Fasting; Female; Glucagon-Like Peptide 1; Glucagon-Like Peptides; Humans; Hypoglycemic Agents; Immunoglobulin Fc Fragments; Male; Metformin; Middle Aged; Postprandial Period; Recombinant Fusion Proteins; Thiazolidinediones; Treatment Outcome | 2011 |
The effects of LY2189265, a long-acting glucagon-like peptide-1 analogue, in a randomized, placebo-controlled, double-blind study of overweight/obese patients with type 2 diabetes: the EGO study.
To evaluate the efficacy and tolerability of once-weekly LY2189265 (LY), a novel glucagon-like peptide-1 (GLP-1) IgG4-Fc fusion protein, in patients with type 2 diabetes failing oral antihyperglycaemic medications (OAMs).. Placebo-controlled, double-blind study in 262 patients (mean age 57 ± 12 years; BMI 33.9 ± 4.1 kg/m(2); and glycosylated haemoglobin A1c (A1c) 8.24 ± 0.93%) receiving two OAMs. Patients were randomized to once-weekly subcutaneous injections of placebo or LY 0.5 mg for 4 weeks, then 1.0 mg for 12 weeks (LY 0.5/1.0); 1.0 mg for 16 weeks (LY 1.0/1.0); or 1.0 mg for 4 weeks, then 2.0 mg for 12 weeks (LY 1.0/2.0).. At week 16, A1c changes (least-squares mean ± standard error) were -0.24 ± 0.12, -1.38 ± 0.12, -1.32 ± 0.12 and -1.59 ± 0.12%, in the placebo, LY 0.5/1.0, LY 1.0/1.0 and LY 1.0/2.0 arms, respectively (all p < 0.001 vs. placebo). Both fasting (p < 0.001) and postprandial (p < 0.05) blood glucose decreased significantly compared to placebo at all LY doses. Weight loss was dose dependent and ranged from -1.34 ± 0.39 to -2.55 ± 0.40 kg at 16 weeks (all p < 0.05 vs. placebo). At the highest LY dosage, the most common adverse events were nausea (13.8%), diarrhoea (13.8%) and abdominal distension (13.8%). Hypoglycaemia was uncommon overall (≤0.8 episodes/patient/30 days) but more common with LY than placebo through the initial 4 weeks (p < 0.05). No differences in cardiovascular events or blood pressure were shown between treatments.. LY2189265, given to overweight/obese patients with type 2 diabetes for 16 weeks in combination with OAMs, was relatively well tolerated and significantly reduced A1c, blood glucose and body weight. Topics: Area Under Curve; Blood Glucose; Diabetes Mellitus, Type 2; Dose-Response Relationship, Drug; Double-Blind Method; Glucagon-Like Peptide 1; Glucagon-Like Peptides; Glycated Hemoglobin; Humans; Hypoglycemic Agents; Immunoglobulin Fc Fragments; Male; Middle Aged; Obesity; Postprandial Period; Recombinant Fusion Proteins; Treatment Outcome; Weight Loss | 2011 |
LY2189265, a long-acting glucagon-like peptide-1 analogue, showed a dose-dependent effect on insulin secretion in healthy subjects.
To assess the safety, tolerability, pharmacokinetics, pharmacodynamics and potential immunogenicity of single, escalating subcutaneous injections of a once-weekly glucagon-like peptide-1 analogue in healthy subjects.. This phase 1, three-period, crossover, double-blind, placebo-controlled study investigated single, escalating subcutaneous doses of LY2189265 (LY) ranging from 0.1 to 12 mg; approximately six subjects were randomized to each dose. Parameters of safety, including adverse events, were assessed. The pharmacokinetic profile was assessed over 14 days. Pharmacodynamic parameters (glucose and insulin concentrations) were measured following a step-glucose infusion (day 3) and as part of an oral glucose tolerance test (OGTT) (day 5).. LY was generally well tolerated with some increase in gastrointestinal symptoms with escalating doses. There were small dose-dependent increases in pulse rate with doses ≥1.0 mg and diastolic blood pressure with doses ≥3.0 mg. The half-life of LY was approximately 90 h, with C(max) occurring between 24 and 48 h in most subjects. Evidence of increase in glucose-dependent insulin secretion and suppression of serum glucose excursions were observed during an OGTT at all doses compared to placebo; no episodes of hypoglycaemia occurred. No subjects developed antibodies to LY2189265.. LY showed an acceptable safety profile and exhibited the expected glucagon-like peptide-1 pharmacological effects on glucose suppression and insulin secretion with a half-life that supports once-weekly dosing. Topics: Adolescent; Adult; Area Under Curve; Cross-Over Studies; Diabetes Mellitus, Type 2; Dose-Response Relationship, Drug; Double-Blind Method; Female; Glucagon-Like Peptide 1; Glucagon-Like Peptides; Glucose Tolerance Test; Half-Life; Humans; Hypoglycemic Agents; Immunoglobulin Fc Fragments; Injections, Subcutaneous; Insulin; Male; Middle Aged; Recombinant Fusion Proteins; Treatment Outcome; Young Adult | 2011 |
Exogenous glucagon-like peptide-1 attenuates the glycaemic response to postpyloric nutrient infusion in critically ill patients with type-2 diabetes.
Glucagon-like peptide-1 (GLP-1) attenuates the glycaemic response to small intestinal nutrient infusion in stress-induced hyperglycaemia and reduces fasting glucose concentrations in critically ill patients with type-2 diabetes. The objective of this study was to evaluate the effects of acute administration of GLP-1 on the glycaemic response to small intestinal nutrient infusion in critically ill patients with pre-existing type-2 diabetes.. Eleven critically ill mechanically-ventilated patients with known type-2 diabetes received intravenous infusions of GLP-1 (1.2 pmol/kg/minute) and placebo from t = 0 to 270 minutes on separate days in randomised double-blind fashion. Between t = 30 to 270 minutes a liquid nutrient was infused intraduodenally at a rate of 1 kcal/min via a naso-enteric catheter. Blood glucose, serum insulin and C-peptide, and plasma glucagon were measured. Data are mean ± SEM.. GLP-1 attenuated the overall glycaemic response to nutrient (blood glucose AUC30-270 min: GLP-1 2,244 ± 184 vs. placebo 2,679 ± 233 mmol/l/minute; P = 0.02). Blood glucose was maintained at < 10 mmol/l in 6/11 patients when receiving GLP-1 and 4/11 with placebo. GLP-1 increased serum insulin at 270 minutes (GLP-1: 23.4 ± 6.7 vs. placebo: 16.4 ± 5.5 mU/l; P < 0.05), but had no effect on the change in plasma glucagon.. Exogenous GLP-1 in a dose of 1.2 pmol/kg/minute attenuates the glycaemic response to small intestinal nutrient in critically ill patients with type-2 diabetes. Given the modest magnitude of the reduction in glycaemia the effects of GLP-1 at higher doses and/or when administered in combination with insulin, warrant evaluation in this group.. ANZCTR:ACTRN12610000185066. Topics: Blood Glucose; Critical Care; Critical Illness; Diabetes Mellitus, Type 2; Dose-Response Relationship, Drug; Double-Blind Method; Enteral Nutrition; Female; Glucagon-Like Peptide 1; Humans; Hypoglycemic Agents; Male; Middle Aged; Pylorus; Treatment Outcome | 2011 |
Liraglutide improves treatment satisfaction in people with Type 2 diabetes compared with sitagliptin, each as an add on to metformin.
Patient-reported outcomes from clinical trials offer insight into the impact of disease on health-related quality of life, including treatment satisfaction. This patient-reported outcomes evaluation was a substudy of a 26-week randomized, open-label trial comparing the once-daily injectable human GLP-1 analogue liraglutide with once-daily oral sitagliptin, both added to metformin. The patient reported outcomes substudy aimed to evaluate treatment satisfaction using the Diabetes Treatment Satisfaction Questionnaire (DTSQ) at baseline and 26 weeks.. In the main 26-week randomized, open-label study (n =658), liraglutide, 1.2 or 1.8 mg, injected with a pen, led to greater HbA1c reduction than oral sitagliptin, 100 mg once daily, both added to metformin = 1500 mg daily: mean HbA1c reduction was 1.5, 1.2 and 0.9% (7, 10 and 14 mmol/mol) for liraglutide 1.8 mg, 1.2 mg and sitagliptin, respectively (P < 0.0001 for both liraglutide doses vs. sitagliptin) and liraglutide patients lost more weight (3 vs.1 kg; P < 0.0001). In this patient-reported outcomes substudy (liraglutide 1.8 mg, n = 171; 1.2 mg, n = 164; sitagliptin, n = 170) DTSQ scores were analyzed by ANCOVA with treatment and country as fixed effects and baseline value as covariate.. Overall treatment satisfaction, calculated by adding satisfaction scores for `current treatment', `convenience', `flexibility', `understanding', `recommend', and `continue', improved in all groups at 26 weeks; greater improvement with liraglutide (4.35 and 3.51 vs. 2.96; P = 0.03 for liraglutide 1.8 mg vs. sitagliptin) may reflect greater HbA1c reduction and weight loss. Patients perceived themselves to be hyperglycaemic significantly less frequently with liraglutide 1.8 mg (difference = -0.88; P < 0.0001) and 1.2 mg ( -0.49; P = 0.01). Perceived frequency of hypoglycaemia was similar across all groups.. Injectable liraglutide may lead to greater treatment satisfaction than oral sitagliptin, potentially by facilitating greater improvement in glycaemic control, weight loss and/ or perception of greater treatment efficacy. Topics: Diabetes Mellitus, Type 2; Drug Therapy, Combination; Female; Glucagon-Like Peptide 1; Glycated Hemoglobin; Humans; Hypoglycemic Agents; Liraglutide; Male; Metformin; Patient Satisfaction; Pyrazines; Quality of Life; Sitagliptin Phosphate; Surveys and Questionnaires; Treatment Outcome; Triazoles | 2011 |
GIP does not potentiate the antidiabetic effects of GLP-1 in hyperglycemic patients with type 2 diabetes.
The incretin glucagon-like peptide 1 (GLP-1) exerts insulinotropic activity in type 2 diabetic patients, whereas glucose-dependent insulinotropic polypeptide (GIP) no longer does. We studied whether GIP can alter the insulinotropic or glucagonostatic activity of GLP-1 in type 2 diabetic patients.. Twelve patients with type 2 diabetes (nine men and three women; 61 ± 10 years; BMI 30.0 ± 3.7 kg/m²; HbA(1c) 7.3 ± 1.5%) were studied. In randomized order, intravenous infusions of GLP-1(7-36)-amide (1.2 pmol · kg⁻¹ · min⁻¹), GIP (4 pmol · kg⁻¹ · min⁻¹), GLP-1 plus GIP, and placebo were administered over 360 min after an overnight fast (≥ 1 day wash-out period between experiments). Capillary blood glucose, plasma insulin, C-peptide, glucagon, GIP, GLP-1, and free fatty acids (FFA) were determined.. Exogenous GLP-1 alone reduced glycemia from 10.3 to 5.1 ± 0.2 mmol/L. Insulin secretion was stimulated (insulin, C-peptide, P < 0.0001), and glucagon was suppressed (P = 0.009). With GIP alone, glucose was lowered slightly (P = 0.0021); insulin and C-peptide were stimulated to a lesser degree than with GLP-1 (P < 0.001). Adding GIP to GLP-1 did not further enhance the insulinotropic activity of GLP-1 (insulin, P = 0.90; C-peptide, P = 0.85). Rather, the suppression of glucagon elicited by GLP-1 was antagonized by the addition of GIP (P = 0.008). FFA were suppressed by GLP-1 (P < 0.0001) and hardly affected by GIP (P = 0.07).. GIP is unable to further amplify the insulinotropic and glucose-lowering effects of GLP-1 in type 2 diabetes. Rather, the suppression of glucagon by GLP-1 is antagonized by GIP. Topics: Adult; Aged; Diabetes Mellitus, Type 2; Drug Interactions; Female; Gastric Inhibitory Polypeptide; Glucagon-Like Peptide 1; Humans; Hyperglycemia; Hypoglycemic Agents; Incretins; Male; Middle Aged | 2011 |
The once-daily human glucagon-like peptide-1 (GLP-1) analog liraglutide improves postprandial glucose levels in type 2 diabetes patients.
Fasting and postprandial plasma glucose (FPG, PPG) control are both necessary to achieve glycosylated hemoglobin (HbA(1c)) regulation goals. Liraglutide, based on its glucagon-like peptide 1 (GLP-1)-mediated pharmacology and pharmacokinetics may reduce HbA(1c) through both FPG and PPG levels. The objective of the present study was to investigate the effect of once-daily liraglutide (0.6, 1.2, and 1.8 mg) at steady state on FPG, PPG, postprandial insulin, and gastric emptying.. Eighteen subjects with type 2 diabetes, aged 18-70 years, with a body mass index of 18.5-40 kg/m(2) and HbA(1c) of 7.0%-9.5% were included in this single-centre, randomized, placebo-controlled, double-blind, two-period, cross over trial. Patients were randomized into two groups (A or B). Group A received oncedaily liraglutide for 3 weeks, followed by a 3-4-week washout period and 3 weeks of oncedaily placebo. Group B was treated as for Group A, but treatment periods were reversed (ie, placebo followed by liraglutide). A meal test was performed at steady-state liraglutide/placebo doses of 0.6, 1.2, and 1.8 mg/day. Plasma glucose, insulin, and paracetamol (acetaminophen) concentrations (to assess gastric emptying) were measured pre- and postmeal.. PPG levels significantly decreased (P<0.001) after all three liraglutide doses when compared with placebo. This decrease was also apparent when corrected for baseline (incremental excursions), with the exception of average incremental increase calculated as area under the concentration curve (AUC) over the fasting value from time zero to 5 hours (iAUC (0-5 h)/5 hours) after liraglutide 0.6 mg, where there was a trend to decrease (P=0.082). In addition, FPG levels significantly decreased at all three liraglutide dose levels when compared to placebo (P<0.001). Fasting and postprandial insulin levels significantly increased with liraglutide versus placebo at all doses studied (P<0.001). A significant delay in gastric emptying during the first hour postmeal was observed at the two highest liraglutide doses versus placebo.. In addition to lowering FPG levels, liraglutide improves PPG levels (absolute and incremental) possibly by both stimulating postprandial insulin secretion and delaying gastric emptying. Topics: Adolescent; Adult; Aged; Blood Glucose; Cross-Over Studies; Diabetes Mellitus, Type 2; Double-Blind Method; Fasting; Female; Gastric Emptying; Glucagon-Like Peptide 1; Humans; Incretins; Insulin; Liraglutide; Male; Middle Aged; Postprandial Period; Young Adult | 2011 |
Cost-effectiveness of liraglutide versus rosiglitazone, both in combination with glimepiride in treatment of type 2 diabetes in the US.
Many patients with type 2 diabetes mellitus (T2DM) are not able to maintain adequate HbA(1c) control (<7.0%), even at maximal dosage levels of one or two oral agents, and are at increased risk for diabetes-related complications.. To estimate the cost-effectiveness of a once-daily GLP-1 analog Victoza [Novo Nordisk] versus a thiazolidinedione (TZD), rosiglitazone in patients with T2DM. Both treatment groups included background therapy with glimepiride.. The CORE Diabetes Model (CDM) was used to project and compare 35-year clinical and economic outcomes associated with liraglutide 1.2 mg + glimepiride and liraglutide 1.8 mg + glimepiride versus rosiglitazone 4 mg + glimepiride. Baseline cohort characteristics (HbA(1c) (8.4%), age, duration of disease, sex, body-mass index (BMI), blood pressure, and lipids) were based on the Liraglutide Effect and Action in Diabetes-1 (LEAD-1) trial.. Primary outcomes included life expectancy (LE), quality-adjusted life-years (QALYs), total costs and incremental cost-effectiveness ratios (ICERs). results: When compared to rosiglitazone, liraglutide 1.2 mg and 1.8 mg increased mean LE by 0.968 and 1.041 years, and QALYs by 0.764 and 0.837, respectively. Total lifetime costs increased by $26,094 for liraglutide 1.2 mg versus rosiglitazone, and by $47,041 for liraglutide 1.8 mg versus rosiglitazone. ICERs for liraglutide 1.2 mg versus rosiglitazone and 1.8 mg versus rosiglitazone were $34,147 and $56,190, respectively.. Compared to rosiglitazone 4 mg plus glimepiride, liraglutide (particularly at the 1.2-mg dose) plus glimepiride is a cost-effective treatment option for improving glucose control in T2DM. Limitations include the projection of short term efficacy results from randomized control trials to longer time horizons. In addition, clinical acceptance and overall use of rosiglitazone in the treatment of diabetes has continued to fall since publication of the clinical trial upon which this modeling analyses was based. Topics: Costs and Cost Analysis; Diabetes Mellitus, Type 2; Drug Therapy, Combination; Female; Glucagon-Like Peptide 1; Humans; Hypoglycemic Agents; Liraglutide; Male; Middle Aged; Quality of Life; Rosiglitazone; Sulfonylurea Compounds; Thiazolidinediones; United States | 2011 |
One year of liraglutide treatment offers sustained and more effective glycaemic control and weight reduction compared with sitagliptin, both in combination with metformin, in patients with type 2 diabetes: a randomised, parallel-group, open-label trial.
The aim of this study was to compare the efficacy and safety of once-daily human glucagon-like peptide-1 analogue liraglutide with dipeptidyl peptidase-4 inhibitor sitagliptin, each added to metformin, over 52 weeks in individuals with type 2 diabetes.. In an open-label, parallel-group trial, metformin-treated participants were randomised to liraglutide 1.2 mg/day (n=225), liraglutide 1.8 mg/day (n=221) or sitagliptin 100 mg/day (n=219) for 26 weeks (main phase). Participants continued the same treatment in a 26-week extension.. Liraglutide (1.2 or 1.8 mg) was superior to sitagliptin for reducing HbA(1c) from baseline (8.4-8.5%) to 52 weeks: -1.29% and -1.51% vs. -0.88% respectively. Estimated mean treatment differences between liraglutide and sitagliptin were as follows: -0.40% (95% confidence interval -0.59 to -0.22) for 1.2 mg and -0.63% (-0.81 to -0.44) for 1.8 mg (both p<0.0001). Weight loss was greater with liraglutide 1.2 mg (-2.78 kg) and 1.8 mg (-3.68 kg) than sitagliptin (-1.16 kg) (both p<0.0001). Diabetes Treatment Satisfaction Questionnaire scores increased significantly more with liraglutide 1.8 mg than with sitagliptin (p=0.03). Proportions of participants reporting adverse events were generally comparable; minor hypoglycaemia was 8.1%, 8.3% and 6.4% for liraglutide 1.2 mg, 1.8 mg and sitagliptin respectively. Gastrointestinal side effects, mainly nausea, initially occurred more frequently with liraglutide, but declined after several weeks.. Liraglutide provides greater sustained glycaemic control and body weight reduction over 52 weeks. Treatment satisfaction was significantly greater with 1.8 mg liraglutide, similar to 26-week results. The safety profiles of liraglutide and sitagliptin are consistent with previous reports. Topics: Aged; Blood Glucose; Diabetes Mellitus, Type 2; Drug Therapy, Combination; Fasting; Female; Glucagon-Like Peptide 1; Glycated Hemoglobin; Humans; Hypoglycemic Agents; Liraglutide; Male; Metformin; Middle Aged; Pyrazines; Sitagliptin Phosphate; Treatment Outcome; Triazoles; Weight Loss | 2011 |
Dose response of subcutaneous GLP-1 infusion in patients with type 2 diabetes.
To evaluate the dose-response relationship of the recombinant glucagon-like peptide-1 (7-36) amide (rGLP-1) administered by continuous subcutaneous infusion (CSCI) in subjects with type 2 diabetes, with respect to reductions in fasting, postprandial and 11-h serum glucose profiles.. In a double-blind, parallel, placebo-controlled trial, 47 patients were randomized to placebo or rGLP-1 (1.25, 2.5, 5.0 or 8.5 pmol/kg/min) by CSCI for 7 days. On day 1 (pretreatment) and on day 8, patients underwent monitoring of fasting, postprandial, and 11-h profiles of glucose and hormones.. Fasting serum glucose decreased by 76.2, 53.9, 37.0 and 22.7 mg/dl for the 8.5, 5.0, 2.5 and 1.25 pmol/kg/min rGLP-1 groups, respectively, compared to a decrease of 1.1 mg/dl for placebo (p = 0.0002, 0.005, 0.064 and 0.27, respectively). Mean 11-h serum glucose area under the curve decreased by 36.3, 23.3, 16.9 and 10.0% for 8.5, 5.0, 2.5 and 1.25 pmol/kg/min rGLP-1, respectively, compared to no change for placebo (p = 0.0001, 0.0019, 0.012 and 0.14, respectively). Mean fasting C-peptide increased dose dependently with rGLP-1 (p = 0.0023 for the highest dose) and decreased with placebo. There were no serious safety concerns and no instances of hypoglycaemia.. rGLP-1 produced continuous improvements in glycaemic control across a broad dose range of up to 8.5 pmol/kg/min. Topics: Blood Glucose; C-Peptide; Diabetes Mellitus, Type 2; Dose-Response Relationship, Drug; Double-Blind Method; Female; Glucagon-Like Peptide 1; Humans; Hypoglycemic Agents; Infusions, Subcutaneous; Male; Middle Aged; Peptide Fragments; Placebos; Postprandial Period | 2011 |
Patient-reported outcomes are superior in patients with Type 2 diabetes treated with liraglutide as compared with exenatide, when added to metformin, sulphonylurea or both: results from a randomized, open-label study.
The Liraglutide Effect and Action in Diabetes 6 trial was an open-label trial comparing liraglutide with exenatide as an 'add-on' to metformin and/or sulphonylurea.. Patients with Type 2 diabetes were randomized to liraglutide 1.8 mg once daily or exenatide 10 μg twice daily for 26 weeks. This was followed by a 14-week extension phase, in which all patients received liraglutide 1.8 mg once daily.. Patient-reported outcomes were measured in 379 patients using Diabetes Treatment Satisfaction Questionnaire status (DTSQs) and DTSQ change (DTSQc). The change in overall treatment satisfaction (DTSQs score) from baseline at week 26 with liraglutide was 4.71 and with exentaide was 1.66 [difference between groups 3.04 (95% CI 1.73-4.35), P<0.0001]. Five of the six items on the DTSQs improved significantly more with liraglutide than with exenatide (differences: current treatment 0.37, P=0.0093; convenience 0.68, P<0.0001; flexibility 0.57, P=0.0002; recommend 0.49, P=0.0003; continue 0.66, P=0.0001). Patients perceived a greater reduction in hypoglycaemia at week 26 with liraglutide than with exenatide [difference in DTSQc score 0.48 (0.08-0.89), P=0.0193] and a greater reduction in perceived hyperglycaemia [difference 0.74 (0.31-1.17), P=0.0007]. During the extension phase, when all patients received liraglutide, DTSQs scores remained stable in patients who continued on liraglutide and increased significantly (P=0.0026) in those switching from exenatide.. These results demonstrate significant improvements in patients' treatment satisfaction with liraglutide compared with exenatide. Topics: Adolescent; Adult; Aged; Aged, 80 and over; Blood Glucose; Diabetes Mellitus, Type 2; Drug Administration Schedule; Female; Glucagon-Like Peptide 1; Glycated Hemoglobin; Humans; Hypoglycemia; Liraglutide; Male; Middle Aged; Patient Satisfaction; Sulfonylurea Compounds; Surveys and Questionnaires; Treatment Outcome; Young Adult | 2011 |
DURATION-2: efficacy and safety of switching from maximum daily sitagliptin or pioglitazone to once-weekly exenatide.
In the initial 26-week, double-blind, double-dummy assessment period of the DURATION-2 trial in patients with Type 2 diabetes on metformin, the once-weekly glucagon-like peptide 1 (GLP-1) receptor agonist exenatide once-weekly resulted in greater HbA(1c) improvement and weight reduction compared with maximum approved daily doses of sitagliptin or pioglitazone. This subsequent, 26-week, open-label, uncontrolled assessment period evaluated the safety and efficacy of (i) continued exenatide once-weekly treatment and (ii) switching from sitagliptin or pioglitazone to exenatide once-weekly.. Randomised oral medications were discontinued and all patients received exenatide once-weekly. Of the 364 patients [original baseline HbA(1c) 8.5 ± 1.1% (70 mmol/mol), fasting plasma glucose 9.0 ± 2.5 mmol/l, weight 88 ± 20 kg) who continued into the open-label period, 319 patients (88%) completed 52 weeks.. Evaluable patients who received only exenatide once-weekly demonstrated significant 52-week improvements (least square mean ± se) in HbA(1c) (-1.6 ± 0.1%), fasting plasma glucose (-1.8 ± 0.3 mmol/l) and weight (-1.8 ± 0.5 kg). Evaluable patients who switched from sitagliptin to exenatide once-weekly demonstrated significant incremental improvements in HbA(1c) (-0.3 ± 0.1%), fasting plasma glucose (-0.7 ± 0.2 mmol/l) and weight (-1.1 ± 0.3 kg). Patients who switched from pioglitazone to exenatide once-weekly maintained HbA(1c) and fasting plasma glucose improvements (week 52: -1.6 ± 0.1%, -1.7 ± 0.3 mmol/l), with significant weight reduction (-3.0 ± 0.3 kg). Exenatide once-weekly was generally well tolerated and adverse events were predominantly mild or moderate in intensity. Nausea was the most frequent adverse event in this assessment period (intent-to-treat: exenatide once-weekly-only 5%; sitagliptin→exenatide once-weekly 11%; pioglitazone→exenatide once-weekly 10%). No major hypoglycaemia was observed.. Patients who switched to once-weekly exenatide from daily sitagliptin or pioglitazone had improved or sustained glycaemic control, with weight loss. Topics: Diabetes Mellitus, Type 2; Double-Blind Method; Drug Administration Schedule; Drug Substitution; Exenatide; Female; Glucagon-Like Peptide 1; Glycated Hemoglobin; Humans; Hypoglycemic Agents; Male; Metformin; Middle Aged; Peptides; Pioglitazone; Pyrazines; Sitagliptin Phosphate; Thiazolidinediones; Treatment Outcome; Triazoles; Venoms | 2011 |
Liraglutide treatment is associated with a low frequency and magnitude of antibody formation with no apparent impact on glycemic response or increased frequency of adverse events: results from the Liraglutide Effect and Action in Diabetes (LEAD) trials.
Therapeutic proteins/peptides can produce immunogenic responses that may increase the risk of adverse events or reduce efficacy.. The objectives were to measure and characterize antibody formation to liraglutide, a glucagon-like peptide-1 receptor agonist, to investigate the impact on glycemic control and safety, and to compare it with exenatide, an agent in the same class.. Antibody data were collected during six Liraglutide Effect and Action in Diabetes (LEAD) trials (26-104 wk duration).. Samples for determination of antibody formation were collected at LEAD trial sites and analyzed at central laboratories.. Antibodies were measured in LEAD trial participants with type 2 diabetes.. Interventions included once-daily liraglutide (1.2 or 1.8 mg) or twice-daily exenatide (10 μg).. The main outcome measures included the proportion of patients positive for anti-liraglutide or anti-exenatide antibodies, a glucagon-like peptide-1 cross-reacting effect, and an in vitro liraglutide- or exenatide-neutralizing effect. Change in glycosylated hemoglobin A(1c) (HbA(1c)) by antibody status and magnitude [negative, positive (high or low level)].. After 26 wk, 32 of 369 (8.7%) and 49 of 587 (8.3%) patients had low-level antibodies to liraglutide 1.2 and 1.8 mg, respectively [mean 3.3% antibody-bound radioactivity out of total radioactivity (%B/T), range 1.6-10.7%B/T], which did not attenuate glycemic efficacy (HbA(1c) reductions 1.1-1.3% in antibody-positive vs. 1.2% in antibody-negative patients). In LEAD-6, 113 of 185 extension patients (61%) had anti-exenatide antibodies at wk 26 (range 2.4-60.2%B/T). High levels of anti-exenatide antibodies were correlated with significantly smaller HbA(1c) reductions (P = 0.0022). After switching from exenatide to liraglutide, anti-exenatide antibodies did not compromise a further glycemic response to liraglutide (additional 0.4% HbA(1c) reduction).. Liraglutide was less immunogenic than exenatide; the frequency and levels of anti-liraglutide antibodies were low and did not impact glycemic efficacy or safety. Topics: Antibody Formation; Blood Glucose; Diabetes Mellitus, Type 2; Exenatide; Female; Glucagon-Like Peptide 1; Humans; Liraglutide; Male; Peptides; Radioimmunoassay; Venoms | 2011 |
Effects of the long-acting human glucagon-like peptide-1 analog liraglutide on plasma omentin-1 levels in patients with type 2 diabetes mellitus.
Omentin is a protein expressed and secreted from visceral but not subcutaneous adipose tissue, which increases insulin sensitivity in human adipocytes. However, its pathophysiologic role in humans remains largely unknown. The objective of this study is to assess plasma omentin-1 levels in patients with type 2 diabetes mellitus (T2DM) and matched control subjects and to investigate the effects of liraglutide on plasma omentin-1 levels in patients with T2DM.. Thirty T2DM patients with poor glycemic control after more than 3 months of treatment with one or two OHA(s) (T2DM), and 30 matched normal glycaemic controls (NGT) participated in the study. The T2DM group was given an injection of liraglutide once-daily for 16 weeks. Plasma omentin-1 levels were measured by enzyme-linked immunosorbent assay and the relationship between plasma omentin-1 levels and metabolic parameters was also analyzed.. Plasma omentin-1 levels were lower in T2DM than in the control (19.3 ± 4.0 μg/L vs. 26.4 ± 6.0 μg/L, P < 0.01). Plasma omentin-1 levels increased significantly in T2DM patients after treatment with liraglutide compared with pre-treatment (19.3 ± 4.0 μg/L vs. 21.2 ± 3. 9 μg/L, P < 0.01). In all diabetic patients, multiple regression analysis showed that FINS and HOMA-IR were independently associated with plasma omentin-1 levels.. In T2DM patients, plasma omentin-1 levels decreased, but significantly increased after the treatment with liraglutide and metformin. These data suggest that liraglutide may play a role in increasing omentin-1 levels in T2DM patients. Topics: Adolescent; Adult; Aged; Cytokines; Diabetes Mellitus, Type 2; Female; Glucagon-Like Peptide 1; GPI-Linked Proteins; Humans; Incretins; Lectins; Liraglutide; Male; Middle Aged; Young Adult | 2011 |
Almond ingestion at mealtime reduces postprandial glycemia and chronic ingestion reduces hemoglobin A(1c) in individuals with well-controlled type 2 diabetes mellitus.
Cohort studies are equivocal regarding a relationship between regular nut consumption and reduced risk of type 2 diabetes mellitus. Although acute trials show reductions in postprandial glycemia in healthy individuals ingesting 60 to 90 g almonds, trials have not been conducted using a single serving of almonds (28 g) in individuals with type 2 diabetes mellitus. This randomized crossover trial examined the impact of one serving of almonds at mealtime on postprandial glycemia, insulinemia, and plasma glucagon-like peptide-1 in healthy individuals and individuals with type 2 diabetes mellitus. On 2 occasions separated by at least 1 week, 19 adults (including 7 adults with type 2 diabetes mellitus) consumed a standardized evening meal and fasted overnight before ingesting the test meal (bagel, juice, and butter) with or without almonds. A small pilot study (6-7 subjects per group) was also conducted to observe whether chronic almond ingestion (1 serving 5 d/wk for 12 weeks) lowered hemoglobin A(1c) in individuals with type 2 diabetes mellitus. A standard serving of almonds reduced postprandial glycemia significantly in participants with diabetes (-30%, P = .043) but did not influence glycemia in participants without diabetes (-7%, P = .638). Insulinemia and glucagon-like peptide-1 at 30 minutes postmeal were not impacted by almond ingestion for either group. In the pilot study, regular almond ingestion for 12 weeks reduced hemoglobin A(1c) by 4% (P = .045 for interaction) but did not influence fasting glucose concentrations. These data show that modest almond consumption favorably improves both short-term and long-term markers of glucose control in individuals with uncomplicated type 2 diabetes mellitus. Topics: Aged; Amylases; Blood Glucose; Cross-Over Studies; Diabetes Mellitus, Type 2; Female; Glucagon-Like Peptide 1; Glycated Hemoglobin; Humans; Male; Middle Aged; Postprandial Period; Prunus | 2011 |
Early improvement in glycemic control after bariatric surgery and its relationships with insulin, GLP-1, and glucagon secretion in type 2 diabetic patients.
The surgical treatment of obesity ameliorates metabolic abnormalities in patients with type 2 diabetes. The objective of this study was to evaluate the early effects of Roux-en-Y gastric bypass (RYGB) on metabolic and hormonal parameters in patients with type 2 diabetes (T2DM).. Ten patients with T2DM (BMI, 39.7 ± 1.9) were evaluated before and 7, 30, and 90 days after RYGB. A meal test was performed, and plasma insulin, glucose, glucagon, and glucagon-like-peptide 1 (GLP-1) levels were measured at fasting and postprandially.. Seven days after RYGB, a significant reduction was observed in HOMA-IR index from 7.8 ± 5.5 to 2.6 ± 1.7; p < 0.05 was associated with a nonsignificant reduction in body weight. The insulin and GLP-1 curves began to show a peak at 30 min after food ingestion, while there was a progressive decrease in glucagon and blood glucose levels throughout the meal test. Thirty and 90 days after RYGB, along with progressive weight loss, blood glucose and hormonal changes remained in the same direction and became more expressive with the post-meal insulin curve suggesting recovery of the first phase of insulin secretion and with the increase in insulinogenic index, denoting improvement in β-cell function. Furthermore, a positive correlation was found between changes in GLP-1 and insulin levels measured at 30 min after meal (r = 0.6; p = 0.000).. Our data suggest that the RYGB surgery, beyond weight loss, induces early beneficial hormonal changes which favor glycemic control in type 2 diabetes. Topics: Adult; Aged; Blood Glucose; Diabetes Mellitus, Type 2; Female; Gastric Bypass; Glucagon; Glucagon-Like Peptide 1; Humans; Insulin; Insulin Resistance; Male; Middle Aged; Obesity; Prospective Studies; Treatment Outcome; Weight Loss | 2011 |
The metabolic syndrome influences the response to incretin-based therapies.
We hypothesize that type 2 diabetic patients with different phenotypes may show different response to incretin-based therapies. Therefore, we tested whether the presence of metabolic syndrome (MS) influences glycemic response to these drugs. We prospectively followed 211 patients, treated with the GLP-1 analog exenatide (n = 102) or a DPP-4 inhibitor (n = 109) for at least 4 months. Treatment was decided on clinical grounds. We collected baseline data (age, sex, BMI, waist, systolic and diastolic blood pressure, lipid profile, data on diabetic complications and concomitant treatment) and HbA1c at subsequent visits. Patients were divided into groups according to the presence/absence of MS. Compared to patients on exenatide, patients on DPP-4 inhibitors were older and had lower BMI, waist, diastolic blood pressure, fasting plasma glucose, and HbA1c. At means of baseline values, HbA1c reduction was similar in patients treated with exenatide or DPP-4 inhibitors. Patients on exenatide showed significantly higher HbA1c reduction if they had MS (-1.55 ± 0.22%; n = 88) than if they had not (-0.34 ± 0.18%; P = 0.002). Conversely, patients on DPP-4 inhibitors showed significantly lower HbA1c reduction if they had MS (-0.60 ± 0.12%; n = 73) than if they had not (-1.50 ± 0.24%; P < 0.001). Type of MS definition (ATP-III, IDF or WHO) poorly influenced these trends. The interaction between type of therapy (exenatide vs. DPP-4 inhibitors) and MS remained significant after adjusting for age, baseline HbA1c, BMI, and concomitant medications. In conclusion, the presence of MS appears to modify the response to incretin-based therapies. Given the non-randomized nature of this study, these data need to be replicated. Topics: Adamantane; Aged; Diabetes Mellitus, Type 2; Dipeptidyl-Peptidase IV Inhibitors; Exenatide; Female; Glucagon-Like Peptide 1; Humans; Hypoglycemic Agents; Incretins; Male; Metabolic Syndrome; Middle Aged; Nitriles; Peptides; Prognosis; Pyrazines; Pyrrolidines; Sitagliptin Phosphate; Treatment Outcome; Triazoles; Venoms; Vildagliptin | 2011 |
Glutamine reduces postprandial glycemia and augments the glucagon-like peptide-1 response in type 2 diabetes patients.
Impaired glucagon-like peptide (GLP-1) secretion or response may contribute to ineffective insulin release in type 2 diabetes. The conditionally essential amino acid glutamine stimulates GLP-1 secretion in vitro and in vivo. In a randomized, crossover study, we evaluated the effect of oral glutamine, with or without sitagliptin (SIT), on postprandial glycemia and GLP-1 concentration in 15 type 2 diabetes patients (glycated hemoglobin 6.5 ± 0.6%). Participants ingested a low-fat meal (5% fat) after receiving either water (control), 30 g l-glutamine (Gln-30), 15 g L-glutamine (Gln-15), 100 mg SIT, or 100 mg SIT and 15 g L-glutamine (SIT+Gln-15). Studies were conducted 1-2 wk apart. Blood was collected at baseline and postprandially for 180 min for measurement of circulating glucose, insulin, C-peptide, glucagon, and total and active GLP-1. Gln-30 and SIT+Gln-15 reduced the early (t = 0-60 min) postprandial glycemic response compared with control. All Gln treatments enhanced the postprandial insulin response from t = 60-180 min but had no effect on the C-peptide response compared with control. The postprandial glucagon concentration was increased by Gln-30 and Gln-15 compared with control, but the insulin:glucagon ratio was not affected by any treatment. In contrast to Gln-30, which tended to increase the total GLP-1 AUC, SIT tended to decrease the total GLP-1 AUC relative to control (both P = 0.03). Gln-30 and SIT increased the active GLP-1 AUC compared with control (P = 0.008 and P = 0.01, respectively). In summary, Gln-30 decreased the early postprandial glucose response, enhanced late postprandial insulinemia, and augmented postprandial active GLP-1 responses compared with control. These findings suggest that glutamine may be a novel agent for stimulating GLP-1 concentration and limiting postprandial glycemia in type 2 diabetes. Topics: Administration, Oral; Aged; Blood Glucose; C-Peptide; Cross-Over Studies; Diabetes Mellitus, Type 2; Female; Gastric Emptying; Glucagon; Glucagon-Like Peptide 1; Glutamine; Humans; Hyperglycemia; Insulin; Insulin Secretion; Male; Middle Aged; Postprandial Period; Pyrazines; Sitagliptin Phosphate; Triazoles | 2011 |
[Development of the novel delivery system of GLP-1 administration for the treatment of diabetes mellitus].
Glucagon-like peptide 1 (GLP-1) is a peptide produced in the endocrine L cells of the distal intestine. GLP-1(7-36)NH2 is a major molecular form that stimulates insulin release, reduces food intake, and has a potential to promote beta-cell regeneration. We have developed a device for intranasal application of GLP-1(7-36)NH2 and completed a double-blind clinical trial of intranasal administration of GLP-1(7-36)NH2 to 26 type II diabetic patients. Intranasal administration of GLP-1 increased its plasma level, stimulated postprandial insulin release, and suppressed glucagon release. Two-week intranasal administration of GLP-1 just before meals significantly decreased serum glycoalbumin level and significantly increased 1,5-AG (1,5-anhydro-D-glucitol) level. Hypoglycemia was not found through this study. Intranasal GLP-1 administration using the novel device and medication improved glycemic control in type 2 diabetic patients without any adverse effects. Topics: Administration, Intranasal; Diabetes Mellitus, Type 2; Double-Blind Method; Drug Delivery Systems; Equipment Design; Glucagon-Like Peptide 1; Humans; Incretins | 2011 |
Effects of exenatide twice daily versus sitagliptin on 24-h glucose, glucoregulatory and hormonal measures: a randomized, double-blind, crossover study.
To compare exenatide and sitagliptin glucose and glucoregulatory measures in subjects with type 2 diabetes.. An 8-week, double-blind, randomized, crossover, single-centre study. Eighty-six subjects (58% female, body mass index 35 ± 5 kg/m², haemoglobin A1c 8.3 ± 1.0%) received either exenatide 10 µg (subcutaneous) twice daily or sitagliptin 100 mg (oral) daily for 4 weeks and crossed to the other therapy for an additional 4 weeks. Main outcome was time-averaged glucose during the 24-h inpatient visits.. Both treatments decreased average 24-h glucose, but exenatide had a greater effect [between-group difference: -0.67 mmol/l, 95% confidence interval (CI): -0.9 to -0.4 mmol/l]. Both treatments decreased 2-h postprandial glucose (PPG), area under the curve of glucose above 7.8 mmol/l (140 mg/dl) and 11 mmol/l (200 mg/dl) and increased the time spent with glucose between 3.9 and 7.8 mmol/l (70 and 140 mg/dl) during 24 h, but exenatide had a significantly greater effect (p < 0.05). Both treatments decreased postprandial serum glucagon, with exenatide having a greater effect (p < 0.005). Both treatments decreased fasting blood glucose to a similar degree (p = 0.766). Sitagliptin increased, while exenatide decreased, postprandial intact glucagon-like peptide-1. Both drugs improved homeostasis model assessment of β-cell function (HOMA-B), with exenatide having a significantly greater effect (p = 0.005). Both exenatide and sitagliptin decreased 24-h caloric intake, with exenatide having a greater effect (p < 0.001). There was no episode of major hypoglycaemia. Adverse events were mild to moderate and mostly gastrointestinal in nature with exenatide. No study withdrawals were due to an adverse event.. Compared to sitagliptin, exenatide showed significantly lower average 24-h glucose, 2-h PPG, glucagon, caloric intake and improved HOMA-B. Topics: Adolescent; Adult; Aged; Biomarkers; Blood Glucose; Body Mass Index; Cross-Over Studies; Diabetes Mellitus, Type 2; Dipeptidyl-Peptidase IV Inhibitors; Double-Blind Method; Exenatide; Female; Glucagon-Like Peptide 1; Glycated Hemoglobin; Humans; Hypoglycemic Agents; Male; Middle Aged; Peptides; Postprandial Period; Pyrazines; Sitagliptin Phosphate; Time Factors; Triazoles; Venoms; Young Adult | 2011 |
Effect of the dipeptidyl peptidase-4 inhibitor sitagliptin in older adults with type 2 diabetes mellitus.
Topics: Age Factors; Aged; Blood Glucose; Diabetes Mellitus, Type 2; Dipeptidyl-Peptidase IV Inhibitors; Female; Gastric Inhibitory Polypeptide; Glucagon; Glucagon-Like Peptide 1; Glucose Clamp Technique; Humans; Insulin; Male; Pyrazines; Sitagliptin Phosphate; Treatment Outcome; Triazoles | 2011 |
The effect of the once-daily human glucagon-like peptide 1 analog liraglutide on the pharmacokinetics of acetaminophen.
Acetaminophen is a commonly used analgesic and antipyretic drug, and is frequently used to study gastric emptying. Due to its high permeability and high solubility, acetaminophen can be used as a pharmacologic model for medications with similar characteristics. The objective of this study was to assess the effect of liraglutide on the pharmacokinetics (PK) of acetaminophen in patients with type 2 diabetes.. This was a randomized, placebo-controlled, two-period crossover trial in which subjects with type 2 diabetes received placebo or liraglutide. After steady state PK of liraglutide 1.8 mg/ placebo were established, a single dose of acetaminophen 1 g was administered at the time of liraglutide C(max) (maximum concentration). The PK profile of acetaminophen was assessed at 18 time points during the 8-hour post-dosing period. Placebo and liraglutide were considered equivalent with respect to area under the curve (AUC)(0-∞) and AUC(0-480) min of acetaminophen if the 90% CI for the ratio was fully contained within the limits of 0.80 to 1.25.. All subjects (n=18; mean [SD] age 59 [7] years, body mass index [BMI] 29.7 [4.2] kg/m(2), and glycated hemoglobin [HbA(1c)] 7.8% [0.6%]) completed the study. Equivalence was demonstrated between liraglutide 1.8 mg at steady state and placebo, with respect to acetaminophen AUC(0-∞) (estimated ratio 1.04; 90% CI: 0.97, 1.10) and acetaminophen AUC(0-480) min (estimated ratio 0.95; 90% CI: 0.89, 1.01). During liraglutide, a lower C(max) was observed (estimated ratio 0.69; 90% CI: 0.56, 0.85) and the median acetaminophen t(max) occurred 15 minutes later compared with placebo.. The overall exposure of acetaminophen following a 1 g dose was comparable for subjects taking liraglutide or placebo, and the clinical impact of the lower C(max) and delay in absorption of acetaminophen was considered to be transient and small, and without clinical relevance. No adjustment for acetaminophen is recommended when used concomitantly with liraglutide. Topics: Acetaminophen; Adolescent; Adult; Aged; Analgesics, Non-Narcotic; Blood Glucose; Cross-Over Studies; Diabetes Mellitus, Type 2; Drug Interactions; Gastric Emptying; Glucagon-Like Peptide 1; Humans; Hypoglycemic Agents; Liraglutide; Middle Aged; Young Adult | 2011 |
Effects of a long-acting GLP-1 mimetic (PF-04603629) on pulse rate and diastolic blood pressure in patients with type 2 diabetes mellitus.
PF-04603629, an exendin-transferrin fusion protein, is a long-acting glucagon-like peptide-1 (GLP-1) mimetic. This randomized, double-blind study characterized the safety and pharmacodynamics of a single dose of PF-04603629 (n = 57; 1-70 mg) or placebo (n = 14) in subjects with type 2 diabetes mellitus (T2DM). There were dose-dependent decreases from baseline in day 6 glucose area under the curve following a mixed meal test (-27 ± 12% with 70 mg). Most treatment-related adverse events were gastrointestinal, with nausea and vomiting most frequent at 70 mg. Pulse rate (PR) and diastolic blood pressure (DBP) increased dose dependently within the normal range. At 24 h postdose mean PR increased 23 ± 9 bpm and mean DBP increased 10 ± 5 mmHg with 70 mg. In conclusion, PF-04603629 exhibited efficacy and tolerability consistent with its mechanism of action; however, PR and DBP increased. Similar effects have been reported occasionally with other GLP-1 mimetics. These data underscore the importance of careful assessments of haemodynamic effects in GLP-1 analogues. Topics: Adolescent; Adult; Aged; Blood Pressure; Body Mass Index; Diabetes Mellitus, Type 2; Dose-Response Relationship, Drug; Double-Blind Method; Female; Glucagon-Like Peptide 1; Heart Rate; Humans; Hypoglycemic Agents; Male; Middle Aged; Recombinant Fusion Proteins; Young Adult | 2011 |
Effects of short-term therapy with glibenclamide and repaglinide on incretin hormones and oxidative damage associated with postprandial hyperglycaemia in people with type 2 diabetes mellitus.
To examine the effects of glibenclamide and repaglinide on glucose stimulated insulin release, incretins, oxidative stress and cell adhesion molecules in patients with type 2 diabetes suboptimally treated with metformin.. A randomized clinical trial was performed recruiting 27 subjects (HbA(1c) between 7.5 and 10.5%) free from cardiovascular and renal disease. Glucose, insulin, C-peptide, glucagon-like peptide-1 (GLP-1), glucose-dependent insulinotropic peptide (GIP), total antioxidant status, F(2)-isoprostane, interleukin-6 and cell adhesion molecules were measured during an oral glucose load at baseline and after eight weeks of treatment. The areas under the curve were analysed at 45, 60 and 120 min (AUC(45), AUC(60), AUC(120)).. Significant improvements in glucose were observed with repaglinide (HBA(1c): -1.5%, fasting glucose: -2.8 mmol/L, 2-h glucose: -3.7 mmol/L, AUC(120): -18.9%) and glibenclamide (-1.0%, -2.2 mmol/L, -2.5 mmol/L, -17.5%). Repaglinide was also associated with an increase in the AUC(60) and AUC(120) for insulin (+56%, +61%) and C-peptide (+41%, +36%). GLP-1, GIP, IL-6, ICAM-1 and E-selectin levels did not change in either group. No association was observed between GLP-1, GIP-1 and plasma markers of oxidative stress.. Repaglinide is associated with improved postprandial glycaemic control via insulin and C-peptide release. We observed no direct effects of glibenclamide or repaglinide on plasma levels of GLP-1 or GIP. We observed no associations of GLP-1 and GIP with plasma markers of oxidative stress. Topics: Adult; Aged; Analysis of Variance; Biomarkers; Blood Glucose; Carbamates; Diabetes Mellitus, Type 2; Drug Administration Schedule; Drug Therapy, Combination; E-Selectin; F2-Isoprostanes; Female; Gastric Inhibitory Polypeptide; Glucagon-Like Peptide 1; Glyburide; Glycated Hemoglobin; Humans; Hyperglycemia; Hypoglycemic Agents; Incretins; Insulin; Intercellular Adhesion Molecule-1; Interleukin-6; Male; Metformin; Middle Aged; Oxidative Stress; Piperidines; Postprandial Period; Time Factors; Treatment Outcome; Wales | 2011 |
Liraglutide narrows the range of circadian glycemic variations in Japanese type 2 diabetes patients and nearly flattens these variations in drug-naive type 2 diabetes patients: a continuous glucose monitoring-based study.
Liraglutide was examined for its effects on 24-h glucose fluctuations in Japanese type 2 diabetes patients as well as for its differential effects depending on glucose tolerance status after favorable glycemic control was obtained in these patients.. In this prospective open-label pilot study, a total of 20 type 2 diabetes patients hospitalized for glycemic control were given liraglutide 0.3 mg, followed by liraglutide 0.6 mg and 0.9 mg, with each given at 1-week intervals. The patients were continuously monitored for their 24-h glucose levels before treatment and during the course of treatment with liraglutide 0.3 mg, 0.6 mg, and 0.9 mg, respectively, using continuous glucose monitoring (CGM). At the start of treatment with liraglutide, 12 patients were on diet therapy alone, of which six were drug-naive, and eight were being treated with glimepiride.. Liraglutide not only significantly reduced 24-h mean glucose levels but also significantly improved all the indices for glycemic variation evaluated, which included SDs of 24-h glucose levels, mean amplitude of glycemic excursions (MAGE), and total area under the glucose fluctuation curve (AUC) for 24 h. The study showed a significant negative correlation for mean glucose levels, SD, and AUC immediately before treatment versus their changes with liraglutide. A 75-g oral glucose tolerance test (OGTT) was given in 11 patients treated with liraglutide monotherapy once favorable glycemic control was achieved. The OGTT revealed that of these, six were found to have normal glucose tolerance, four had impaired glucose tolerance, and one had diabetes, and that of the six drug-naive patients, five patients were found to have normal glucose tolerance, and one had impaired glucose tolerance.. Study results showed that liraglutide is expected not only to reduce mean glucose levels but also to improve 24-h glucose fluctuations, including postprandial glucose excursions, with its effects being particularly conspicuous in patients with early-stage type 2 diabetes. Topics: Adult; Aged; Asian People; Blood Glucose Self-Monitoring; Circadian Rhythm; Diabetes Mellitus, Type 2; Female; Glucagon-Like Peptide 1; Glucose Tolerance Test; Glycated Hemoglobin; Humans; Hypoglycemic Agents; Liraglutide; Male; Middle Aged; Pilot Projects; Sulfonylurea Compounds; Young Adult | 2011 |
Short reaction of C-peptide, glucagon-like peptide-1, ghrelin and endomorphin-1 for different style diet in type 2 diabetic patients.
Food composition and style is changing dramatically now, which causes inappropriate secretion of hormones from brain, gastrointestinal and endo-pancreas, may be related to unbalance of glucose in blood. The aim of this study was to explore the fast response of C-peptide, glucagon-like peptide-1 (GLP-1), ghrelin and endomorphin-1 (EM-1) to the eastern and western style meals in patients with type 2 diabetes mellitus.. The study enrolled 57 patients with type 2 diabetes (20 men and 37 women, mean age (67.05 ± 8.26) years). Eastern style meal (meal A) and western style meal (meal B) were designed to produce the fullness effect. C-peptide, GLP-1, ghrelin and EM-1 were assessed before (0 hour) and after (2 hours) each diet.. The delta (2h - 0h) of C- peptide in meal A was significantly lower than that in meal B (P = 0.0004). C-peptide, GLP-1, ghrelin and EM-1 were obviously higher before meal B than those before meal A (P < 0.0001, < 0.0001, = 0.001, = 0.0004 respectively). Blood glucose 2 hours and 3 hours after meal B were higher than those after meal A (P = 0.0005, 0.0079 respectively). Correlations between GLP-1 and ghrelin were strongly positive before both meals and 2 hours after both meals and also in relation to the delta of meal A and meal B (r(A0h) = 0.7836, r(B0h) = 0.9368, r(A2h) = 0.7615, r(B2h) = 0.9409, r(A(2h-0h)) = 0.7531, r((2h-0h))B = 0.9980, respectively, P < 0.0001).. Western style meal (high fat and protein food) could make more response of C-peptide than eastern style meal, and could stimulate more gut hormones (GLP-1, ghrelin) and brain peptide (EM-1) at the first phase of digestion. Topics: Aged; C-Peptide; Diabetes Mellitus, Type 2; Diet; Fasting; Female; Ghrelin; Glucagon-Like Peptide 1; Humans; Male; Middle Aged; Oligopeptides; Postprandial Period | 2011 |
Acute effects of casein on postprandial lipemia and incretin responses in type 2 diabetic subjects.
Exaggerated and prolonged postprandial lipemia is potentially atherogenic and associated with type 2 diabetes. Limited data exist regarding the influence of dietary protein on postprandial lipemia in type 2 diabetes. We investigated, over 8-h, the acute effects of casein alone or in combination with carbohydrate on postprandial lipid and incretin responses to a fat-rich meal in type 2 diabetes.. Eleven type 2 diabetic subjects ingested four test meals in random order: an energy-free soup plus 80 g of fat (control-meal); control-meal plus 45 g carbohydrates (CHO-meal); control-meal plus 45 g of casein (PRO-meal); and PRO-meal plus 45 g carbohydrates (CHO+PRO-meal). Triglyceride and retinyl palmitate responses were measured in plasma and in a chylomicron-rich and chylomicron-poor fraction. We found no significant differences in triglyceride responses to PRO- and CHO+PRO-meal compared to the control-meal. However, the addition of casein to the CHO-meal reduced the raised triglyceride response in the chylomicron-rich fraction. Retinyl palmitate responses did not differ significantly between meals in the chylomicron-rich fraction, whereas the PRO-meal increased retinyl palmitate in the chylomicron-poor fraction. PRO- and PRO+CHO-meal increased insulin and glucagon compared to the control-meal. PRO+CHO-meal increased the glucose-dependent insulinotropic peptide response while no change in glucagon-like peptide-1 responses was detected.. The data presented suggest that casein per se did not modulate the postprandial triglyceride response in type 2 diabetes. When added to carbohydrate, casein suppressed the triglyceride response in the chylomicron-rich fraction, increased insulin and glucagon but did not affect the incretin responses. Topics: Aged; Biomarkers; Blood Glucose; Caseins; Chylomicrons; Cross-Over Studies; Diabetes Mellitus, Type 2; Dietary Carbohydrates; Dietary Fats; Dietary Proteins; Diterpenes; Female; Glucagon; Glucagon-Like Peptide 1; Glycated Hemoglobin; Humans; Hyperlipidemias; Hypoglycemic Agents; Incretins; Insulin; Male; Middle Aged; Postprandial Period; Retinyl Esters; Time Factors; Triglycerides; Vitamin A | 2010 |
Adding liraglutide to oral antidiabetic drug therapy: onset of treatment effects over time.
To investigate the onset of treatment effects over time observed for liraglutide in combination with oral antidiabetic drugs (OADs).. This analysis included patients from three phase 3, 26-week, randomised, double-blind, parallel-group trials. Prior to randomisation, patients underwent a run-in and titration period with metformin (Liraglutide Effect and Action in Diabetes-2, LEAD-2), glimepiride (LEAD-1) or metformin plus rosiglitazone (LEAD-4). Patients were then randomised to receive liraglutide (0.6, 1.2 or 1.8 mg once-daily), active comparator and/or placebo. For this analysis, only the 1.2 mg and 1.8 mg liraglutide doses were included. Outcome measures included change in HbA(1c), fasting plasma glucose (FPG), weight and systolic blood pressure (SBP). The safety profile was also investigated.. Significant reductions in HbA(1c) were observed within 8 weeks of treatment with liraglutide plus OADs (p < 0.0001) and maintained until week 26. Furthermore, liraglutide plus OADs led to significant reductions in FPG within 2 weeks (p < 0.0001) and sustained over 26 weeks. Adding liraglutide to metformin or metformin plus rosiglitazone also led to early reductions and maintained reductions in body weight (within 8 weeks, p < 0.0001); however, liraglutide treatment plus glimepiride was weight neutral. Rapid reductions in SBP were observed for liraglutide plus OADs (within 2 weeks, p < 0.05-0.001) and maintained for 26 weeks. Some patients experienced nausea, which for the majority it diminished within 2 weeks.. Liraglutide treatment combined with OADs led to rapid improvements in FPG and SBP. Early reductions in HbA(1c) and body weight were also observed. Adding liraglutide to OADs early on may therefore be a good treatment option for patients with type 2 diabetes. Topics: Administration, Oral; Adolescent; Adult; Aged; Analysis of Variance; Blood Glucose; Blood Pressure; Body Weight; Diabetes Mellitus, Type 2; Fasting; Glucagon-Like Peptide 1; Glycated Hemoglobin; Humans; Hypoglycemic Agents; Liraglutide; Middle Aged; Nausea; Young Adult | 2010 |
Pancreatic beta-cell responses to GLP-1 after near-normalization of blood glucose in patients with type 2 diabetes.
This study investigated the effects of strict glycaemic control on beta-cell function in nine obese subjects with type 2 diabetes (T2DM), using graded glucose infusions together with infusions of saline or GLP-1 before (HbA(1)c: 8.0+/-0.4%) and after four weeks of near-normalization of blood glucose (BG) using insulin (mean diurnal BG: 6.4+/-0.3 mmol/l; HbA(1)c: 6.6+/-0.3%). Nine matched healthy subjects acted as controls. In controls, area-under-curve (AUC) for amylin, C-peptide and proinsulin were higher with GLP-1 than saline (P<0.001). The AUC amylin/C-peptide ratio was similar on both days, while AUC proinsulin/C-peptide ratio was higher with GLP-1 (P=0.02). In the patients, amylin, C-peptide and proinsulin AUCs were unaltered by near-normoglycaemia per se. Proinsulin responses to GLP-1 were unchanged, but amylin and C-peptide AUCs increased (P<0.05) after insulin treatment, and AUC amylin/C-peptide ratios rose to control levels. Near-normoglycaemia tended to reduce AUC proinsulin/C-peptide ratio, which was significant (P=0.04) with GLP-1, but still higher than with saline (P=0.004). In conclusion, amylin, C-peptide and proinsulin responses to glucose were unaffected by four weeks of near-normoglycaemia, whereas GLP-1 increased amylin and C-peptide secretion and amylin/C-peptide ratio. Near-normoglycaemia reduced proinsulin/C-peptide ratio during stimulation with GLP-1, suggesting that strict glycaemic control might ameliorate some of the disturbances in beta-cell function characterizing T2DM. Topics: Amyloid; Area Under Curve; Blood Glucose; C-Peptide; Diabetes Mellitus, Type 2; Female; Glucagon-Like Peptide 1; Glucose; Humans; Incretins; Insulin; Insulin-Secreting Cells; Islet Amyloid Polypeptide; Male; Middle Aged; Proinsulin; Time Factors | 2010 |
Acute effects of gastric bypass versus gastric restrictive surgery on beta-cell function and insulinotropic hormones in severely obese patients with type 2 diabetes.
Hyperglycemia resolves quickly after bariatric surgery, but the underlying mechanism and the most effective type of surgery remains unclear.. To examine glucose metabolism and beta-cell function in patients with type 2 diabetes mellitus (T2DM) after two types of bariatric intervention; Roux-en-Y gastric bypass (RYGB) and gastric restrictive (GR) surgery.. Prospective, nonrandomized, repeated-measures, 4-week, longitudinal clinical trial.. In all, 16 T2DM patients (9 males and 7 females, 52+/-14 years, 47+/-9 kg m(-2), HbA1c 7.2+/-1.1%) undergoing either RYGB (N=9) or GR (N=7) surgery.. Glucose, insulin secretion, insulin sensitivity at baseline, and 1 and 4 weeks post-surgery, using hyperglycemic clamps and C-peptide modeling kinetics; glucose, insulin secretion and gut-peptide responses to mixed meal tolerance test (MMTT) at baseline and 4 weeks post-surgery.. At 1 week post-surgery, both groups experienced a similar weight loss and reduction in fasting glucose (P<0.01). However, insulin sensitivity increased only after RYGB, (P<0.05). At 4 weeks post-surgery, weight loss remained similar for both groups, but fasting glucose was normalized only after RYGB (95+/-3 mg 100 ml(-1)). Insulin sensitivity improved after RYGB (P<0.01) and did not change with GR, whereas the disposition index remained unchanged after RYGB and increased 30% after GR (P=0.10). The MMTT elicited a robust increase in insulin secretion, glucagon-like peptide-1 (GLP-1) levels and beta-cell sensitivity to glucose only after RYGB (P<0.05).. RYGB provides a more rapid improvement in glucose regulation compared with GR. This improvement is accompanied by enhanced insulin sensitivity and beta-cell responsiveness to glucose, in part because of an incretin effect. Topics: Bariatric Surgery; Blood Glucose; Body Mass Index; Body Weight; Diabetes Mellitus, Type 2; Female; Gastric Bypass; Gastrointestinal Hormones; Glucagon-Like Peptide 1; Humans; Insulin; Insulin Resistance; Insulin-Secreting Cells; Male; Middle Aged; Obesity, Morbid; Prospective Studies; Weight Loss | 2010 |
Efficacy and safety of the once-daily human GLP-1 analogue, liraglutide, vs glibenclamide monotherapy in Japanese patients with type 2 diabetes.
Liraglutide is a once-daily human glucagon-like peptide-1 (GLP-1) analogue developed for the treatment of type 2 diabetes mellitus (T2DM). In Phase 2 and Phase 3 trials, largely conducted in populations of European descent, liraglutide has been shown to lower HbA(1C), weight and systolic blood pressure with a low risk of hypoglycaemia. This Phase 3, 24-week, multi-centre, double-blind, double dummy, randomised parallel-group trial compared the efficacy and safety of liraglutide and glibenclamide monotherapy in Japanese subjects with T2DM, inadequately controlled with diet therapy or oral antidiabetic drug (OAD) monotherapy.. A total of 411 Japanese subjects were randomised 2:1 to liraglutide (n = 272) or glibenclamide (n = 139). Liraglutide was administered at a maximum planned dose of 0.9 mg once daily. Glibenclamide was administered once or twice daily at a planned maximum dose of 2.5 mg/day, before or after meals.. NCT00393718.. After 24 weeks, glycaemic control with liraglutide was non-inferior/superior to glibenclamide, with HbA(1C) at 24 weeks of 6.99% (SE +/- 0.07) with liraglutide and 7.50% (+/-0.09) with glibenclamide (difference, -0.5%; 95% CI -0.70 to 0.30; p < 0.0001). Mean fasting plasma glucose (FPG) levels at 24 weeks were significantly lower with liraglutide (7.6 mmol/l [SE +/- 0.1]) vs glibenclamide (8.3 mmol/l [+/-0.1]; difference, -0.72 mmol/l; 95% CI -1.0 to -0.4; p < 0.0001). Weight was reduced by -0.92 kg from a baseline of 65.2 kg in liraglutide-treated patients, compared with weight gain of +0.99 kg from a baseline of 64.8 kg with glibenclamide (difference, -1.91 kg; 95% CI -2.34 to -1.48; p < 0.0001). A significantly lower rate of minor hypoglycaemic episodes was achieved with liraglutide compared with glibenclamide (p < 0.0001), and no major hypoglycaemic episodes were reported in either treatment group. The most common gastrointestinal AEs were diarrhoea (liraglutide, 6.3%; glibenclamide, 3.8%) and constipation (liraglutide, 5.6%; glibenclamide, 3.8%). Nausea was infrequent (liraglutide, 4.5%; glibenclamide, 1.5%).. Liraglutide monotherapy, administered once daily for 24 weeks in Japanese subjects with T2DM, was well tolerated. Compared with glibenclamide monotherapy, liraglutide achieved superior glycaemic control and weight outcome, and a significantly lower incidence of hypoglycaemia. Future studies, comprising a greater proportion of true therapy-naïve Japanese patients, will be beneficial in order to establish the true add-on efficacy of liraglutide monotherapy in patients with T2DM. Topics: Blood Glucose; Body Weight; Diabetes Mellitus, Type 2; Double-Blind Method; Drug Administration Schedule; Glucagon-Like Peptide 1; Glyburide; Glycated Hemoglobin; Humans; Hypoglycemic Agents; Lipids; Liraglutide; Placebos | 2010 |
Switching to once-daily liraglutide from twice-daily exenatide further improves glycemic control in patients with type 2 diabetes using oral agents.
To evaluate efficacy and safety of switching from twice-daily exenatide to once-daily liraglutide or of 40 weeks of continuous liraglutide therapy.. When added to oral antidiabetes drugs in a 26-week randomized trial (Liraglutide Effect and Action in Diabetes [LEAD]-6), liraglutide more effectively improved A1C, fasting plasma glucose, and the homeostasis model of beta-cell function (HOMA-B) than exenatide, with less persistent nausea and hypoglycemia. In this 14-week extension of LEAD-6, patients switched from 10 microg twice-daily exenatide to 1.8 mg once-daily liraglutide or continued liraglutide.. Switching from exenatide to liraglutide further and significantly reduced A1C (0.32%), fasting plasma glucose (0.9 mmol/l), body weight (0.9 kg), and systolic blood pressure (3.8 mmHg) with minimal minor hypoglycemia (1.30 episodes/patient-year) or nausea (3.2%). Among patients continuing liraglutide, further significant decreases in body weight (0.4 kg) and systolic blood pressure (2.2 mmHg) occurred with 0.74 episodes/patient-year of minor hypoglycemia and 1.5% experiencing nausea.. Conversion from exenatide to liraglutide is well tolerated and provides additional glycemic control and cardiometabolic benefits. Topics: Blood Glucose; Diabetes Mellitus, Type 2; Drug Administration Schedule; Exenatide; Glucagon-Like Peptide 1; Humans; Hypoglycemic Agents; Liraglutide; Peptides; Venoms | 2010 |
Twelve weeks treatment with the DPP-4 inhibitor, sitagliptin, prevents degradation of peptide YY and improves glucose and non-glucose induced insulin secretion in patients with type 2 diabetes mellitus.
To examine the effects of 12 weeks of treatment with the DPP-4 inhibitor, sitagliptin, on gastrointestinal hormone responses to a standardized mixed meal and beta cell secretory capacity, measured as glucose and non-glucose induced insulin secretion during a hyperglycaemic clamp, in patients with type 2 diabetes.. A double-blinded, placebo-controlled study over 12 weeks in which 24 patients with T2DM were randomized to receive either sitagliptin (Januvia) 100 mg qd or placebo as an add-on therapy to metformin. In week 0, 1 and 12 patients underwent a meal test and a 90-min 20 mM hyperglycaemic clamp with 5 g of l-arginine infusion. Main outcome measure was postprandial total glucagon-like peptide 1 (GLP-1) concentration. Additional measures were insulin and C-peptide, glycaemic control, intact and total peptide YY (PYY) and glucose-dependent insulinotropic polypeptide (GIP), and intact glucagon-like peptide 2 (GLP-2) and GLP-1.. All patients [sitagliptin n = 12, age: 59.5 (39-64) years, HbA1c: 8.0 (7.3-10.0)%, BMI: 33.2 (29.3-39.4); placebo n = 12, age: 60 (31-72) years, HbA1c: 7.7 (7.1-9.8)%, BMI: 30.7 (25.7-40.5)] [median (range)] completed the trial. Sitagliptin treatment improved glycaemic control, had no effect on total GLP-1, GIP or intact GLP-2, but reduced total PYY and PYY(3- 36), and increased PYY(1- 36) and intact incretin hormones. Sitagliptin improved first and second phases of beta cell secretion and maximal secretory capacity. All effects were achieved after 1 week. No significant changes occurred in the placebo group.. The postprandial responses of total GLP-1 and GIP and intact GLP-2 were unaltered. PYY degradation was prevented. Glucose and non-glucose induced beta cell secretion was improved. There was no difference in responses to sitagliptin between 1 and 12 weeks of treatment. Topics: Adult; Aged; Diabetes Mellitus, Type 2; Dipeptidyl-Peptidase IV Inhibitors; Double-Blind Method; Drug Administration Schedule; Female; Gastric Inhibitory Polypeptide; Glucagon-Like Peptide 1; Glucagon-Like Peptide 2; Humans; Hypoglycemic Agents; Insulin; Insulin Secretion; Male; Metformin; Middle Aged; Peptide YY; Postprandial Period; Pyrazines; Sitagliptin Phosphate; Triazoles | 2010 |
Improved glycaemic control with minimal hypoglycaemia and no weight change with the once-daily human glucagon-like peptide-1 analogue liraglutide as add-on to sulphonylurea in Japanese patients with type 2 diabetes.
Sulphonylureas (SUs) are often used as first-line treatments for type 2 diabetes in Japan, hence it is important to study new antidiabetic drugs in combination with SUs in Japanese patients.. The efficacy and safety of the once-daily human glucagon-like peptide-1 (GLP-1) analogue liraglutide were compared in 264 Japanese subjects [mean body mass index (BMI) 24.9 kg/m(2); mean glycated haemoglobin (HBA1c) 8.4%] randomized and exposed to receive liraglutide 0.6 mg/day (n = 88), 0.9 mg/day (n = 88) or placebo (n = 88) each added to SU monotherapy (glibenclamide, glicazide or glimeprimide) in a 24-week, double-blind, parallel-group trial.. The mean change in HBA1c from baseline to week 24 (LOCF) was -1.56 (s.d. 0.84) and -1.46 (s.d. 0.95) with liraglutide 0.9 and 0.6 mg respectively, and -0.40 (s.d. 0.93) with placebo. HBA1c decreased in the placebo group from 8.45 to 8.06%, while liraglutide reduced HBA1c from 8.60 to 7.14%, and from 8.23 to 6.67% at the 0.6 and 0.9 mg doses respectively. Mean HBA1c at week 24 of the two liraglutide groups were significantly lower than the placebo group (p < 0.0001 for both). More subjects reached HBA1c < 7.0% with liraglutide (0.6 mg: 46.5%; 0.9 mg: 71.3%) vs. placebo (14.8%). Fasting plasma glucose (FPG) levels were significantly improved with liraglutide (difference -1.47 mmol/l and -1.80 mmol/l with 0.6 and 0.9 mg vs. placebo; p < 0.0001). Overall safety was similar between treatments: no major hypoglycaemic episodes were reported, while 84/77/38 minor hypoglycaemic episodes occurred in the 0.6 mg/0.9 mg and placebo treatment groups (all in combination with SU), reflecting lower ambient glucose levels. No relevant change in mean body weight occurred in subjects receiving liraglutide (0.6 mg: 0.06 kg; 0.9 mg: -0.37 kg), while mean body weight decreased in subjects receiving placebo (-1.12 kg).. The addition of liraglutide to SU treatment for 24 weeks dose-dependently improved glycaemic control vs. SU monotherapy, without causing major hypoglycaemia or weight gain or loss. Topics: Asian People; Body Mass Index; Body Weight; Diabetes Mellitus, Type 2; Double-Blind Method; Drug Administration Schedule; Drug Therapy, Combination; Female; Glucagon-Like Peptide 1; Glycated Hemoglobin; Humans; Hypoglycemic Agents; Liraglutide; Male; Middle Aged; Placebos; Sulfonylurea Compounds; Treatment Outcome | 2010 |
Effects of exenatide combined with lifestyle modification in patients with type 2 diabetes.
To determine the effect of a lifestyle modification program plus exenatide versus lifestyle modification program plus placebo on weight loss in overweight or obese participants with type 2 diabetes treated with metformin and/or sulfonylurea.. In this 24-week, multicenter, randomized, double-blind, placebo-controlled study, 194 patients participated in a lifestyle modification program, consisting of goals of 600 kcal/day deficit and physical activity of at least 2.5 hours/week. Participants were randomized to 5 microg exenatide twice daily injection + lifestyle modification program (n = 96) or placebo + lifestyle modification program (n = 98), and after 4 weeks increased their exenatide dose to 10 microg twice daily or volume equivalent of placebo.. Baseline characteristics: (mean +/- standard deviation) age, 54.8 +/- 9.5 years; weight, 95.5 +/- 16.0 kg; hemoglobin A(1c), 7.6 +/- 0.8%. At 24 weeks (least squares mean +/- standard error), treatments showed similar decreases in caloric intake (-378 +/- 58 vs -295 +/- 58 kcal/day, exenatide + lifestyle modification program vs placebo + lifestyle modification program, P = .27) and increases in exercise-derived energy expenditure. Exenatide + lifestyle modification program showed greater change in weight (-6.16 +/- 0.54 kg vs -3.97 +/- 0.52 kg, P = .003), hemoglobin A(1c) (-1.21 +/- 0.09% vs -0.73 +/- 0.09%, P <.0001), systolic (-9.44 +/- 1.40 vs -1.97 +/- 1.40 mm Hg, P <.001) and diastolic blood pressure (-2.22 +/- 1.00 vs 0.47 +/- 0.99 mm Hg, P = .04). Nausea was reported more for exenatide + lifestyle modification program than placebo + lifestyle modification program (44.8% vs 19.4%, respectively, P <.001), with no difference in withdrawal rates due to adverse events (4.2% vs 5.1%, respectively, P = 1.0) or rates of hypoglycemia.. When combined with lifestyle modification, exenatide treatment led to significant weight loss, improved glycemic control, and decreased blood pressure compared with lifestyle modification alone in overweight or obese participants with type 2 diabetes on metformin and/or sulfonylurea treatment. Topics: Adolescent; Adult; Aged; Blood Glucose; Blood Pressure; Body Weight; Diabetes Mellitus, Type 2; Double-Blind Method; Exenatide; Female; Glucagon-Like Peptide 1; Humans; Hypoglycemic Agents; Life Style; Male; Middle Aged; Peptides; Venoms | 2010 |
Liraglutide versus sitagliptin for patients with type 2 diabetes who did not have adequate glycaemic control with metformin: a 26-week, randomised, parallel-group, open-label trial.
Agonists of the glucagon-like peptide-1 (GLP-1) receptor provide pharmacological levels of GLP-1 activity, whereas dipeptidyl peptidase-4 (DPP-4) inhibitors increase concentrations of endogenous GLP-1 and glucose-dependent insulinotropic polypeptide. We aimed to assess the efficacy and safety of the human GLP-1 analogue liraglutide versus the DPP-4 inhibitor sitagliptin, as adjunct treatments to metformin, in individuals with type 2 diabetes who did not achieve adequate glycaemic control with metformin alone.. In this parallel-group, open-label trial, participants (aged 18-80 years) with type 2 diabetes mellitus who had inadequate glycaemic control (glycosylated haemoglobin [HbA(1c)] 7.5-10.0%) on metformin (>or=1500 mg daily for >or=3 months) were enrolled and treated at office-based sites in Europe, the USA, and Canada. Participants were randomly allocated to receive 26 weeks' treatment with 1.2 mg (n=225) or 1.8 mg (n=221) subcutaneous liraglutide once daily, or 100 mg oral sitagliptin once daily (n=219). The primary endpoint was change in HbA(1c) from baseline to week 26. The efficacy of liraglutide versus sitagliptin was assessed hierarchically by a non-inferiority comparison, with a margin of 0.4%, followed by a superiority comparison. Analyses were done on the full analysis set with missing values imputed by last observation carried forward; seven patients assigned to liraglutide did not receive treatment and thus did not meet criteria for inclusion in the full analysis set. This trial is registered with ClinicalTrials.gov, number NCT00700817.. Greater lowering of mean HbA(1c) (8.5% at baseline) was achieved with 1.8 mg liraglutide (-1.50%, 95% CI -1.63 to -1.37, n=218) and 1.2 mg liraglutide (-1.24%, -1.37 to -1.11, n=221) than with sitagliptin (-0.90%, -1.03 to -0.77, n=219). Estimated mean treatment differences for liraglutide versus sitagliptin were -0.60% (95% CI -0.77 to -0.43, p<0.0001) for 1.8 mg and -0.34% (-0.51 to -0.16, p<0.0001) for 1.2 mg liraglutide. Nausea was more common with liraglutide (59 [27%] patients on 1.8 mg; 46 [21%] on 1.2 mg) than with sitagliptin (10 [5%]). Minor hypoglycaemia was recorded in about 5% of participants in each treatment group.. Liraglutide was superior to sitagliptin for reduction of HbA(1c), and was well tolerated with minimum risk of hypoglycaemia. These findings support the use of liraglutide as an effective GLP-1 agent to add to metformin.. Novo Nordisk. Topics: Adolescent; Adult; Aged; Aged, 80 and over; Diabetes Mellitus, Type 2; Dipeptidyl-Peptidase IV Inhibitors; Female; Glucagon-Like Peptide 1; Humans; Hypoglycemic Agents; Liraglutide; Male; Metformin; Middle Aged; Pyrazines; Sitagliptin Phosphate; Treatment Failure; Treatment Outcome; Triazoles; Young Adult | 2010 |
Patient-reported outcomes in patients with type 2 diabetes treated with liraglutide or glimepiride, both as add-on to metformin.
Patient-reported outcomes for liraglutide or glimepiride on metformin were investigated. Patients' treatment satisfaction on liraglutide was higher than with metformin alone and comparable with glimepiride+metformin. Patients perceived lower frequency of hypoglycaemia than glimepiride+metformin and lower frequency of hyperglycaemia than metformin. Impact of weight on quality of life did not differ. Topics: Aged; Diabetes Mellitus, Type 2; Drug Therapy, Combination; Female; Glucagon-Like Peptide 1; Humans; Hypoglycemia; Hypoglycemic Agents; Liraglutide; Male; Metformin; Middle Aged; Patient Satisfaction; Quality of Life; Sulfonylurea Compounds; Treatment Outcome | 2010 |
Effects of miglitol, sitagliptin or their combination on plasma glucose, insulin and incretin levels in non-diabetic men.
alpha-glucosidase inhibitors (alphaGIs) increase active glucagon-like peptide-1 (GLP-1) and reduce the total glucosedependent insulinotropic polypeptide (GIP) levels, but their ability to prevent diabetes remains uncertain. Dipeptidyl peptidase-4 (DPP-4) inhibitors, such as sitagliptin, increase active GLP-1 and GIP levels and improve hyperglycemia in a glucose-dependent fashion. However, the effectiveness of their combination in subjects with normal glucose tolerance (NGT) or impaired glucose tolerance (IGT) is uncertain. The present study evaluated the effect of miglitol, sitagliptin, and their combination on glucose, insulin and incretin levels in non-diabetic men. Miglitol and sitagliptin were administered according to four different intake schedules (C: no drug, M: miglitol; S: sitagliptin, M+S: miglitol and sitagliptin). The plasma glucose levels were significantly lower for M, S and M+S than for the control. The areas under the curve (AUCs) of the plasma active GLP-1 level in the M, S, and M+S groups were significantly greater than that in the control group. The AUC of the plasma active GLP-1 level was significantly greater for M+S group than for the M and S groups. The AUC of the plasma total GIP level was significantly smaller for M+S group than for the control and M and S groups. The results of our study suggest that miglitol, sitagliptin, or their combination contributes to the prevention of type 2 diabetes. Topics: 1-Deoxynojirimycin; Adult; Blood Glucose; Cross-Over Studies; Diabetes Mellitus, Type 2; Drug Therapy, Combination; Enzyme Inhibitors; Food; Glucagon-Like Peptide 1; Glycoside Hydrolase Inhibitors; Humans; Hypoglycemic Agents; Incretins; Insulin; Kinetics; Male; Pyrazines; Sitagliptin Phosphate; Triazoles | 2010 |
Safety and tolerability of high doses of taspoglutide, a once-weekly human GLP-1 analogue, in diabetic patients treated with metformin: a randomized double-blind placebo-controlled study.
The study objective was to investigate the safety and tolerability of up-titration to high doses of taspoglutide, a once-weekly human glucagon-like peptide-1 analogue, in subjects with Type 2 diabetes inadequately controlled on metformin alone.. In this double-blind phase II trial, subjects were randomized to placebo or taspoglutide (20 mg; three separate groups) administered once weekly by subcutaneous injection for 4 weeks. This was followed by dose maintenance at 20 mg, or titration to 30 mg (20/30) or 40 mg (20/40) once weekly with matched placebo for an additional 4 weeks. Subjects were monitored for adverse events (AEs) throughout the study and 4-week follow-up.. One hundred and twenty-nine subjects were randomized and treated [mean age 57 years, mean baseline glycated haemoglobin (HbA(1c)), 7.9%]. The most frequently reported AEs were nausea and vomiting. The number of patients reporting gastrointestinal AEs did not increase following titration to higher doses of taspoglutide or when continuing the initial 20 mg regimen. Three subjects were withdrawn from the study as a result of gastrointestinal AEs (one before and two after titration to higher doses). Although not designed to investigate efficacy, improvement in glycaemic control was observed in all active arms of the study. The proportion of subjects achieving HbA(1c) < 7.0% after 8 weeks of treatment was 72, 53 and 70% in the 20/20-, 20/30- and 20/40-mg arms, respectively, vs. 19% for placebo.. Taspoglutide was safe, well tolerated at high doses and efficacious for lowering HbA(1c). Up-titration of dose was not associated with a worsening AE profile. Topics: Diabetes Mellitus, Type 2; Dipeptidyl-Peptidase IV Inhibitors; Dose-Response Relationship, Drug; Double-Blind Method; Female; Gastrointestinal Diseases; Glucagon-Like Peptide 1; Glucagon-Like Peptide-1 Receptor; Glycated Hemoglobin; Humans; Hypoglycemic Agents; Injections, Subcutaneous; Male; Metformin; Middle Aged; Nausea; Peptides; Receptors, Glucagon; Vomiting | 2010 |
Patient-reported outcomes following treatment with the human GLP-1 analogue liraglutide or glimepiride in monotherapy: results from a randomized controlled trial in patients with type 2 diabetes.
As weight gain and hypoglycaemia associated with glimepiride therapy can negatively impact weight perceptions, psychological well-being and overall quality of life in type 2 diabetes, we investigated whether liraglutide treatment could improve these factors.. Seven hundred and thirty-two patients with type 2 diabetes completed a 77-item questionnaire during a randomized, 52-week, double-blind study with liraglutide 1.2 mg (n = 245) or 1.8 mg (n = 242) compared with glimepiride 8 mg (n = 245).. Mean (SE) decreases in glycated haemoglobin levels were greater with liraglutide 1.2 mg [-0.84 (0.08)%] and 1.8 mg [-1.14 (0.08)%] than glimepiride [-0.51 (0.08)%; p = 0.0014 and p < 0.0001, respectively]. Patients gained weight on glimepiride [mean (SE), 1.12 (0.27) kg] but lost weight on liraglutide [1.2 mg: -2.05 (0.28) kg; 1.8 mg: -2.45 (0.28) kg; both p < 0.0001]. Patient weight assessment was more favourable with liraglutide 1.8 mg [mean (SE) score: 40.0 (2.0)] than glimepiride [48.7 (2.0); p = 0.002], and liraglutide 1.8 mg patients were 52% less likely to feel overweight [odds ratio (OR) 0.48; 95% confidence interval (CI): 0.331-0.696]. Mean (SE) weight concerns were less with liraglutide [1.2 mg: 30.0 (1.2); 1.8 mg: 32.8 (1.2)] than glimepiride [38.8 (1.2); p < 0.0001 and p < 0.001, respectively], with liraglutide groups 45% less likely to report weight concern (OR 0.55, 95% CI: 0.41-0.73). Mean (SE) mental and emotional health and general perceived health improved more with liraglutide 1.8 mg [476.1 (2.8) and 444.2 (3.2), respectively] than glimepiride [466.3 (2.8) and 434.5 (3.2), respectively; p = 0.012 and p = 0.033, respectively].. Improved glycaemic control and decreased weight with liraglutide 1.8 mg vs. glimepiride can improve psychological and emotional well-being and health perceptions by reducing anxiety and worry associated with weight gain. Topics: Diabetes Mellitus, Type 2; Double-Blind Method; Female; Glucagon-Like Peptide 1; Glycated Hemoglobin; Humans; Hypoglycemia; Hypoglycemic Agents; Liraglutide; Male; Middle Aged; Sulfonylurea Compounds; Treatment Outcome; Weight Gain | 2010 |
Pharmacokinetics and pharmacodynamics of inhaled GLP-1 (MKC253): proof-of-concept studies in healthy normal volunteers and in patients with type 2 diabetes.
MKC253 is glucagon-like peptide 1 (GLP-1, 7-36 amide) adsorbed onto Technosphere microparticles for oral inhalation. The pharmacokinetics of inhaled GLP-1 and the pharmacokinetic-pharmacodynamic (PK-PD) relationship between inhaled GLP-1 and insulin were analyzed in two trials, one in healthy normal volunteers and the other in patients with type 2 diabetes. Inhaled GLP-1 was absorbed quickly, with peak concentrations occurring within 5 min, and levels returned to baseline within 30 min. Inhaled GLP-1 appeared to produce plasma levels of GLP-1 comparable to those of parenteral administration and sufficient to induce insulin secretion resulting in attenuation of postmeal glucose excursions in subjects with type 2 diabetes. An E(max) (maximum effect) model described the relationship between GLP-1 concentration and insulin release. The variability in the E(max) may be due to differences in baseline glucose levels, differences resulting from genetic polymorphisms in GLP-1 receptors (GLP-1Rs), or the stage of diabetes of the patient. Topics: Administration, Inhalation; Adult; Aged; Blood Glucose; C-Peptide; Diabetes Mellitus, Type 2; Dose-Response Relationship, Drug; Drug Delivery Systems; Energy Intake; Female; Glucagon; Glucagon-Like Peptide 1; Humans; Hypoglycemic Agents; Insulin; Male; Middle Aged; Peptide Fragments | 2010 |
Once weekly exenatide compared with insulin glargine titrated to target in patients with type 2 diabetes (DURATION-3): an open-label randomised trial.
Diabetes treatments are needed that are convenient, provide effective glycaemic control, and do not cause weight gain. We aimed to test the hypothesis that improvement in haemoglobin A(1c) (HbA(1c)) achieved with once weekly exenatide was superior to that achieved with insulin glargine titrated to glucose targets.. In this 26-week, open-label, randomised, parallel study, we compared exenatide with insulin glargine in adults with type 2 diabetes who had suboptimum glycaemic control despite use of maximum tolerated doses of blood-glucose-lowering drugs for 3 months or longer. Patients were randomly assigned to add exenatide (2 mg, once-a-week injection) or insulin glargine (once-daily injection, starting dose 10 IU, target glucose range 4.0-5.5 mmol/L) to their blood-glucose-lowering regimens. Randomisation was with a one-to-one allocation and block size four, stratified according to country and concomitant treatment (70% metformin only; 30% metformin plus sulphonylurea). Participants and clinical investigators were not masked to assignment, but investigators analysing data were. The primary endpoint was change in HbA(1c) from baseline, and analysis of this outcome was by modified intention to treat for all patients who received at least one dose of study drug. This trial is registered at ClinicalTrials.gov, number NCT00641056.. 456 patients were randomly allocated to treatment and were included in the modified intention-to-treat analysis (233 exenatide, 223 insulin glargine). Participants who received at least one dose of study drug and for whom baseline and at least one postbaseline measurement of HbA(1c) were available were included in the primary efficacy analysis. Change in HbA(1c) at 26 weeks was greater in patients taking exenatide (n=228; -1.5%, SE 0.05) than in those taking insulin glargine (n=220; -1.3%, 0.06; treatment difference -0.16%, 0.07, 95% CI -0.29 to -0.03). 12 (5%) of 233 patients allocated to exenatide and two (1%) of 223 taking insulin glargine discontinued participation because of adverse events (p=0.012). A planned extension period (up to 2.5 years' duration) is in progress.. Once weekly exenatide is an important therapeutic option for patients for whom risk of hypoglycaemia, weight loss, and convenience are particular concerns.. Amylin Pharmaceuticals; Eli Lilly and Company. Topics: Blood Glucose; Diabetes Mellitus, Type 2; Drug Administration Schedule; Exenatide; Female; Glucagon-Like Peptide 1; Glycated Hemoglobin; Humans; Hypoglycemic Agents; Injections, Subcutaneous; Insulin; Insulin Glargine; Insulin, Long-Acting; Male; Middle Aged; Peptides; Venoms | 2010 |
A new C-Peptide correction model used to assess bioavailability of regular human insulin.
The clinical assessment of new formulations of human insulin is problematic due to the inability to distinguish between endogenous insulin and exogenously administered insulin. The usual methods to surmount the problem of distinguishing between endogenous and exogenous human insulin include evaluation in subjects with no or little endogenous insulin, hyper-insulinemic clamp studies or the administration of somatostatin to suppress endogenous insulin secretion. All of these methods have significant drawbacks. This paper describes a method for C-Peptide correction based upon a mixed effects linear regression of multiple time point sampling of C-Peptide and insulin. This model was able to describe each individual's insulin to C-Peptide relationship using the data from four different phase I clinical trials involving both subjects with and without type 2 diabetes in which insulin and C-Peptide were measured. These studies used hyper-insulinemic euglycemic clamps or meal challenges and subjects received insulin or Glucagon-like peptide 1 (GLP-1). It was possible to determine the exogenously administered insulin concentration from the measured total insulin concentration. A simple statistical technique can be used to determine each individual's insulin to C-Peptide relationship to estimate exogenous and endogenous insulin following the administration of regular human insulin. This technique will simplify the assessment of new formulations of human insulin. Topics: Biological Availability; Blood Glucose; C-Peptide; Diabetes Mellitus, Type 2; Glucagon-Like Peptide 1; Glucagon-Like Peptides; Glucose Clamp Technique; Glucose Tolerance Test; Humans; Hypoglycemic Agents; Insulin; Pulmonary Disease, Chronic Obstructive | 2010 |
Pharmacokinetics and pharmacodynamics of vildagliptin in Japanese patients with type 2 diabetes.
To assess the pharmacokinetics, pharmacodynamics and safety of vildagliptin, a potent and selective inhibitor of dipeptidyl peptidase IV (DPP-4), in Japanese patients with Type 2 diabetes.. In this randomized, double-blind, placebo-controlled, parallel-group study, 62 Japanese patients with Type 2 diabetes received vildagliptin 10 mg, 25 mg or 50 mg twice daily for 7 days. Blood samples were collected for the determination of plasma concentrations of vildagliptin, DPP-4, glucagon-like peptide-1 (GLP-1), glucose, insulin and glucagon.. Exposure to vildagliptin (area under the plasma concentration-time curve from 0 to 12 h (AUC0-12h) and the maximum plasma concentration (Cmax)) increased in an approximately dose-proportional manner, and no accumulation was observed following multiple doses of vildagliptin (accumulation factor 1.00 - 1.02). DPP-4 activity was completely inhibited for varying durations by all doses of vildagliptin; the duration of complete DPP-4 inhibition was dose-dependent. DPP-4 inhibition after vildagliptin 50 mg twice daily remained > 80% throughout the 24-h period. Vildagliptin treatment led to a dose-dependent increase in plasma active GLP-1 levels; the overall increases (area under the effect-time course from 0 to 8 h, AUE0-8h) after 7 days' treatment were 1.5-, 1.7-, and 1.8-fold with vildagliptin 10 mg, 25 mg and 50 mg twice daily, respectively (all p < 0.0001 vs. placebo). Postprandial plasma glucose during the 4-h period after breakfast was significantly reduced with the 10, 25 and 50 mg vildagliptin doses by 50.3, 92.2 and 69.5 mg·h/dl, respectively. Insulin levels remained unchanged in the context of reduced glucose levels at all doses studied.. Vildagliptin demonstrated similar pharmacokinetic and pharmacodynamic effects in Japanese patients to those observed previously in non-Japanese patients with Type 2 diabetes. Topics: Adamantane; Adult; Aged; Area Under Curve; Diabetes Mellitus, Type 2; Dipeptidyl-Peptidase IV Inhibitors; Double-Blind Method; Female; Glucagon; Glucagon-Like Peptide 1; Humans; Insulin; Male; Middle Aged; Nitriles; Pyrrolidines; Vildagliptin | 2010 |
Influence of hepatic impairment on pharmacokinetics of the human GLP-1 analogue, liraglutide.
To compare the pharmacokinetics (PK) of a single-dose of liraglutide in subjects with hepatic impairment.. This parallel group, open label trial involved four groups of six subjects with healthy, mild, moderate and severe hepatic impairment, respectively. Each subject received 0.75 mg of liraglutide (s.c., thigh), and blood samples were taken over 72 h for PK assessment. Standard laboratory and safety data were collected. The primary endpoint was area under the plasma liraglutide concentration-time curve from time zero to infinity (AUC(0,∞)).. Exposure to liraglutide was not increased by hepatic impairment. On the contrary, mean AUC(0,∞) was highest for healthy subjects and lowest for subjects with severe hepatic impairment (severe/healthy: 0.56, with 90% CI 0.39, 0.81) and equivalence in this parameter across groups was not demonstrated. C(max) also tended to decrease with hepatic impairment (severe/healthy: 0.71, with 90% CI 0.52, 0.97), but t(max) was similar across groups (11.3-13.2 h). There were no serious adverse events, hypoglycaemic episodes or clinically significant changes in laboratory parameters and liraglutide was considered well tolerated.. This study indicated no safety concerns regarding use of liraglutide in patients with hepatic impairment. Exposure to liraglutide was not increased by impaired liver function; rather, the results suggest a decreased exposure with increasing degree of hepatic impairment. However, data are not conclusive to suggest a dose increase of liraglutide. Thus, the results indicate that patients with type 2 diabetes mellitus and hepatic impairment can use standard treatment regimens of liraglutide. There is, however, currently limited clinical experience with liraglutide in patients with hepatic impairment. Topics: Adolescent; Adult; Aged; Diabetes Mellitus, Type 2; Female; Glucagon-Like Peptide 1; Half-Life; Humans; Hypoglycemic Agents; Liraglutide; Liver Diseases; Male; Middle Aged; Serum Albumin; Severity of Illness Index; Young Adult | 2010 |
Liraglutide versus glimepiride monotherapy for type 2 diabetes (LEAD-3 Mono): a randomised, 52-week, phase III, double-blind, parallel-treatment trial.
New treatments for type 2 diabetes mellitus are needed to retain insulin-glucose coupling and lower the risk of weight gain and hypoglycaemia. We aimed to investigate the safety and efficacy of liraglutide as monotherapy for this disorder.. In a double-blind, double-dummy, active-control, parallel-group study, 746 patients with early type 2 diabetes were randomly assigned to once daily liraglutide (1.2 mg [n=251] or 1.8 mg [n=247]) or glimepiride 8 mg (n=248) for 52 weeks. The primary outcome was change in proportion of glycosylated haemoglobin (HbA(1c)). Analysis was done by intention-to-treat. This trial is registered with ClinicalTrials.gov, number NTC00294723.. At 52 weeks, HbA(1c) decreased by 0.51% (SD 1.20%) with glimepiride, compared with 0.84% (1.23%) with liraglutide 1.2 mg (difference -0.33%; 95% CI -0.53 to -0.13, p=0.0014) and 1.14% (1.24%) with liraglutide 1.8 mg (-0.62; -0.83 to -0.42, p<0.0001). Five patients in the liraglutide 1.2 mg, and one in 1.8 mg groups discontinued treatment because of vomiting, whereas none in the glimepiride group did so.. Liraglutide is safe and effective as initial pharmacological therapy for type 2 diabetes mellitus and leads to greater reductions in HbA(1c), weight, hypoglycaemia, and blood pressure than does glimepiride. Topics: Blood Glucose; Blood Pressure; Diabetes Mellitus, Type 2; Double-Blind Method; Female; Glucagon-Like Peptide 1; Glycated Hemoglobin; Humans; Hypoglycemic Agents; Liraglutide; Male; Middle Aged; Sulfonylurea Compounds | 2009 |
Efficacy and safety comparison of liraglutide, glimepiride, and placebo, all in combination with metformin, in type 2 diabetes: the LEAD (liraglutide effect and action in diabetes)-2 study.
The efficacy and safety of adding liraglutide (a glucagon-like peptide-1 receptor agonist) to metformin were compared with addition of placebo or glimepiride to metformin in subjects previously treated with oral antidiabetes (OAD) therapy.. In this 26-week, double-blind, double-dummy, placebo- and active-controlled, parallel-group trial, 1,091 subjects were randomly assigned (2:2:2:1:2) to once-daily liraglutide (either 0.6, 1.2, or 1.8 mg/day injected subcutaneously), to placebo, or to glimepiride (4 mg once daily). All treatments were in combination therapy with metformin (1g twice daily). Enrolled subjects (aged 25-79 years) had type 2 diabetes, A1C of 7-11% (previous OAD monotherapy for > or =3 months) or 7-10% (previous OAD combination therapy for > or =3 months), and BMI < or =40 kg/m(2).. A1C values were significantly reduced in all liraglutide groups versus the placebo group (P < 0.0001) with mean decreases of 1.0% for 1.8 mg liraglutide, 1.2 mg liraglutide, and glimepiride and 0.7% for 0.6 mg liraglutide and an increase of 0.1% for placebo. Body weight decreased in all liraglutide groups (1.8-2.8 kg) compared with an increase in the glimepiride group (1.0 kg; P < 0.0001). The incidence of minor hypoglycemia with liraglutide ( approximately 3%) was comparable to that with placebo but less than that with glimepiride (17%; P < 0.001). Nausea was reported by 11-19% of the liraglutide-treated subjects versus 3-4% in the placebo and glimepiride groups. The incidence of nausea declined over time.. In subjects with type 2 diabetes, once-daily liraglutide induced similar glycemic control, reduced body weight, and lowered the occurrence of hypoglycemia compared with glimepiride, when both had background therapy of metformin. Topics: Adult; Aged; Diabetes Mellitus, Type 2; Drug Therapy, Combination; Female; Glucagon-Like Peptide 1; Glycated Hemoglobin; Humans; Hypoglycemic Agents; Liraglutide; Male; Metformin; Middle Aged; Obesity; Placebos; Safety; Sulfonylurea Compounds | 2009 |
Treatment with the dipeptidyl peptidase-4 inhibitor vildagliptin improves fasting islet-cell function in subjects with type 2 diabetes.
Dipeptidyl peptidase 4 (DPP-4) inhibitors are proposed to lower blood glucose in type 2 diabetes mellitus (T2DM) by prolonging the activity of the circulating incretins, glucose-dependent insulinotropic polypeptide (GIP) and glucagon-like peptide 1 (GLP-1). Consistent with this mechanism of action, DPP-4 inhibitors improve glucose tolerance after meals by increasing insulin and reducing glucagon levels in the plasma. However, DPP-4 inhibitors also reduce fasting blood glucose, an unexpected effect because circulating levels of active GIP and GLP-1 are low in the postabsorptive state.. The objective of the study was to examine the effects of DPP-4 inhibition on fasting islet function.. We conducted a randomized, double-blind, placebo-controlled trial.. The study was performed in General Clinical Research Centers at two University Hospitals.. Forty-one subjects with T2DM were treated with metformin or diet, having good glycemic control with glycosylated hemoglobin values of 6.2-7.5%.. Subjects were treated with vildagliptin (50 mg twice daily) or placebo for 3 months, followed by a 2-wk washout. Major Outcome Measure: We measured insulin secretion in response to iv glucose and arginine before and after treatment and after drug washout.. There were small and comparable reductions in glycosylated hemoglobin in both groups over 3 months. Vildagliptin increased fasting GLP-1 levels in subjects taking metformin, but not those managed with diet, and raised active GIP levels slightly. DPP-4 inhibitor treatment improved the acute insulin and C-peptide responses to glucose (50 and 100% respectively; P < 0.05) and increased the slope of the C-peptide response to glucose (33%; P = 0.023).. Vildagliptin improves islet function in T2DM under fasting conditions. This suggests that DPP-4 inhibition has metabolic benefits in addition to enhancing meal-induced GLP-1 and GIP activity. Topics: Adamantane; Aged; Diabetes Mellitus, Type 2; Dipeptidyl-Peptidase IV Inhibitors; Double-Blind Method; Fasting; Glucagon-Like Peptide 1; Glycated Hemoglobin; Humans; Islets of Langerhans; Middle Aged; Nitriles; Pyrrolidines; Vildagliptin | 2009 |
Oral glutamine increases circulating glucagon-like peptide 1, glucagon, and insulin concentrations in lean, obese, and type 2 diabetic subjects.
Incretin hormones, such as glucagon-like peptide 1 (GLP-1) and glucose-dependent insulinotropic polypeptide (GIP), play an important role in meal-related insulin secretion. We previously demonstrated that glutamine is a potent stimulus of GLP-1 secretion in vitro.. Our objective was to determine whether glutamine increases circulating GLP-1 and GIP concentrations in vivo and, if so, whether this is associated with an increase in plasma insulin.. We recruited 8 healthy normal-weight volunteers (LEAN), 8 obese individuals with type 2 diabetes or impaired glucose tolerance (OB-DIAB) and 8 obese nondiabetic control subjects (OB-CON). Oral glucose (75 g), glutamine (30 g), and water were administered on 3 separate days in random order, and plasma concentrations of GLP-1, GIP, insulin, glucagon, and glucose were measured over 120 min.. Oral glucose led to increases in circulating GLP-1 concentrations, which peaked at 30 min in LEAN (31.9 +/- 5.7 pmol/L) and OB-CON (24.3 +/- 2.1 pmol/L) subjects and at 45 min in OB-DIAB subjects (19.5 +/- 1.8 pmol/L). Circulating GLP-1 concentrations increased in all study groups after glutamine ingestion, with peak concentrations at 30 min of 22.5 +/- 3.4, 17.9 +/- 1.1, and 17.3 +/- 3.4 pmol/L in LEAN, OB-CON, and OB-DIAB subjects, respectively. Glutamine also increased plasma GIP concentrations but less effectively than glucose. Consistent with the increases in GLP-1 and GIP, glutamine significantly increased circulating plasma insulin concentrations. Glutamine stimulated glucagon secretion in all 3 study groups.. Glutamine effectively increases circulating GLP-1, GIP, and insulin concentrations in vivo and may represent a novel therapeutic approach to stimulating insulin secretion in obesity and type 2 diabetes. Topics: Administration, Oral; Adult; Area Under Curve; Blood Glucose; Cross-Over Studies; Diabetes Mellitus, Type 2; Female; Gastric Inhibitory Polypeptide; Glucagon; Glucagon-Like Peptide 1; Glucose Tolerance Test; Glutamine; Humans; Insulin; Insulin Secretion; Male; Obesity; Thinness | 2009 |
Dipeptidyl-peptidase-IV inhibition augments postprandial lipid mobilization and oxidation in type 2 diabetic patients.
Dipeptidyl-peptidase-IV (DPP-4) inhibition increases endogenous GLP-1 activity, resulting in improved glycemic control in patients with type 2 diabetes mellitus. The metabolic response may be explained in part by extrapancreatic mechanisms.. We tested the hypothesis that DPP-4 inhibition with vildagliptin elicits changes in adipose tissue and skeletal muscle metabolism.. We conducted a randomized, double-blind, crossover study at an academic clinical research center.. Twenty patients with type 2 diabetes, body mass index between 28 and 40 kg/m(2), participated.. INTERVENTION included 7 d treatment with the selective DPP-4 inhibitor vildagliptin or placebo and a standardized test meal on d 7.. Venous DPP-4 activity, catecholamines, free fatty acids, glycerol, glucose, (pro)insulin, dialysate glucose, lactate, pyruvate, glycerol were measured.. Fasting and postprandial venous insulin, glucose, glycerol, triglycerides, and free fatty acid concentrations were not different with vildagliptin and with placebo. Vildagliptin augmented the postprandial increase in plasma norepinephrine. Furthermore, vildagliptin increased dialysate glycerol and lactate concentrations in adipose tissue while suppressing dialysate lactate and pyruvate concentration in skeletal muscle. The respiratory quotient increased with meal ingestion but was consistently lower with vildagliptin.. Our study is the first to suggest that DPP-4 inhibition augments postprandial lipid mobilization and oxidation. The response may be explained by sympathetic activation rather than a direct effect on metabolic status. Topics: Adamantane; Adipose Tissue; Adult; Aged; Cross-Over Studies; Diabetes Mellitus, Type 2; Dipeptidyl-Peptidase IV Inhibitors; Double-Blind Method; Female; Glucagon-Like Peptide 1; Humans; Hypoglycemic Agents; Lipid Mobilization; Male; Middle Aged; Muscle, Skeletal; Nitriles; Norepinephrine; Oxidation-Reduction; Postprandial Period; Pyrrolidines; Vildagliptin | 2009 |
Vildagliptin enhances islet responsiveness to both hyper- and hypoglycemia in patients with type 2 diabetes.
Dipeptidyl peptidase-4 inhibitors act by increasing plasma levels of glucagon-like peptide-1 and suppressing excessive glucagon secretion in patients with type 2 diabetes. However, their effects on the glucagon response to hypoglycemia are not established.. The aim of the study was to assess effects of the dipeptidyl peptidase-4 inhibitor vildagliptin on alpha-cell response to hyper- and hypoglycemia.. We conducted a single-center, randomized, double-blind, placebo-controlled, two-period crossover study of 28-d treatment, with a 4-wk between-period washout.. We studied drug-naive patients with type 2 diabetes and baseline glycosylated hemoglobin of 7.5% or less.. Participants received vildagliptin (100 mg/d) or placebo as outpatients. PRIMARY OUTCOME MEASURE(S): We measured the following: 1) change in plasma glucagon levels during hypoglycemic (2.5 mm glucose) clamp; and 2) incremental (Delta) glucagon area under the concentration-time curve from time 0 to 60 min (AUC(0-60 min)) during standard meal test. Before the study, it was hypothesized that vildagliptin would suppress glucagon secretion during meal tests and enhance the glucagon response to hypoglycemia.. The mean change in glucagon during hypoglycemic clamp was 46.7 +/- 6.9 ng/liter with vildagliptin treatment and 33.9 +/- 6.7 ng/liter with placebo; the between-treatment difference was 12.8 +/- 7.0 ng/liter (P = 0.039), representing a 38% increase with vildagliptin. In contrast, the mean glucagon DeltaAUC(0-60 min) during meal test with vildagliptin was 512 +/- 163 ng/liter x min vs. 861 +/- 130 ng/liter x min with placebo; the between-treatment difference was -349 +/- 158 ng/liter x min (P = 0.019), representing a 41% decrease with vildagliptin.. Vildagliptin enhances alpha-cell responsiveness to both the suppressive effects of hyperglycemia and the stimulatory effects of hypoglycemia. These effects likely contribute to the efficacy of vildagliptin to improve glycemic control as well as to its low hypoglycemic potential. Topics: Adamantane; Aged; Blood Glucose; Body Mass Index; Cross-Over Studies; Diabetes Mellitus, Type 2; Double-Blind Method; Female; Glucagon; Glucagon-Like Peptide 1; Glycated Hemoglobin; Humans; Hyperglycemia; Hypoglycemia; Hypoglycemic Agents; Insulin; Insulin Secretion; Male; Middle Aged; Nitriles; Pyrrolidines; Vildagliptin | 2009 |
Long-term outcomes in patients with type 2 diabetes receiving glimepiride combined with liraglutide or rosiglitazone.
Poor control of type 2 diabetes results in substantial long-term consequences. Studies of new diabetes treatments are rarely designed to assess mortality, complication rates and costs. We sought to estimate the long-term consequences of liraglutide and rosiglitazone both added to glimepiride.. To estimate long-term clinical and economic consequences, we used the CORE diabetes model, a validated cohort model that uses epidemiologic data from long-term clinical trials to simulate morbidity, mortality and costs of diabetes. Clinical data were extracted from the LEAD-1 trial evaluating two doses (1.2 mg and 1.8 mg) of a once daily GLP-1 analog liraglutide, or rosiglitazone 4 mg, on a background of glimepiride in type 2 diabetes. CORE was calibrated to the LEAD-1 baseline patient characteristics. Survival, cumulative incidence of cardiovascular, ocular and renal events and healthcare costs were estimated over three periods: 10, 20 and 30 years.. In a hypothetical cohort of 5000 patients per treatment followed for 30 years, liraglutide 1.2 mg and 1.8 mg had higher survival rates compared to the group treated with rosiglitazone (15.0% and 16.0% vs. 12.6% after 30 years), and fewer cardiovascular, renal, and ocular events. Cardiovascular death rates after 30 years were 69.7%, 68.4% and 72.5%, for liraglutide 1.2 mg, 1.8 mg, and rosiglitazone, respectively. First and recurrent amputations were lower in the rosiglitazone group, probably due to a 'survival paradox' in the liraglutide arms (number of events: 565, 529, and 507, respectively). Overall cumulative costs per patient, were lower in both liraglutide groups compared to rosiglitazone (US$38,963, $39,239, and $40,401 for liraglutide 1.2 mg, 1.8 mg, and rosiglitazone, respectively), mainly driven by the costs of cardiovascular events in all groups.. Using data from LEAD-1 and epidemiologic evidence from the CORE diabetes model, projected rates of mortality, diabetes complications and healthcare costs over the long term favor liraglutide plus glimepiride over rosiglitazone plus glimepiride.. LEAD-1 NCT00318422; LEAD-2 NCT00318461; LEAD-3 NCT 00294723; LEAD-4 NCT00333151; LEAD-5 NCT00331851; LEAD-6 NCT00518882. Topics: Aged; Cohort Studies; Diabetes Mellitus, Type 2; Drug Therapy, Combination; Female; Follow-Up Studies; Glucagon-Like Peptide 1; Humans; Liraglutide; Male; Middle Aged; Rosiglitazone; Sulfonylurea Compounds; Thiazolidinediones; Treatment Outcome | 2009 |
Efficacy and safety of the human glucagon-like peptide-1 analog liraglutide in combination with metformin and thiazolidinedione in patients with type 2 diabetes (LEAD-4 Met+TZD).
To determine the efficacy and safety of liraglutide (a glucagon-like peptide-1 receptor agonist) when added to metformin and rosiglitazone in type 2 diabetes.. This 26-week, double-blind, placebo-controlled, parallel-group trial randomized 533 subjects (1:1:1) to once-daily liraglutide (1.2 or 1.8 mg) or liraglutide placebo in combination with metformin (1 g twice daily) and rosiglitazone (4 mg twice daily). Subjects had type 2 diabetes, A1C 7-11% (previous oral antidiabetes drug [OAD] monotherapy >or=3 months) or 7-10% (previous OAD combination therapy >or=3 months), and BMI Topics: Adolescent; Adult; Aged; Blood Glucose; Blood Pressure; Diabetes Mellitus, Type 2; Double-Blind Method; Drug Therapy, Combination; Fasting; Glucagon-Like Peptide 1; Glycated Hemoglobin; Humans; Hypoglycemic Agents; Liraglutide; Metformin; Middle Aged; Placebos; Safety; Thiazolidinediones; Young Adult | 2009 |
Liraglutide, a once-daily human GLP-1 analogue, added to a sulphonylurea over 26 weeks produces greater improvements in glycaemic and weight control compared with adding rosiglitazone or placebo in subjects with Type 2 diabetes (LEAD-1 SU).
To compare the effects of combining liraglutide (0.6, 1.2 or 1.8 mg/day) or rosiglitazone 4 mg/day (all n >or= 228) or placebo (n = 114) with glimepiride (2-4 mg/day) on glycaemic control, body weight and safety in Type 2 diabetes.. In total, 1041 adults (mean +/- sd), age 56 +/- 10 years, weight 82 +/- 17 kg and glycated haemoglobin (HbA(1c)) 8.4 +/- 1.0% at 116 sites in 21 countries were stratified based on previous oral glucose-lowering mono : combination therapies (30 : 70%) to participate in a five-arm, 26-week, double-dummy, randomized study.. Liraglutide (1.2 or 1.8 mg) produced greater reductions in HbA(1c) from baseline, (-1.1%, baseline 8.5%) compared with placebo (+0.2%, P < 0.0001, baseline 8.4%) or rosiglitazone (-0.4%, P < 0.0001, baseline 8.4%) when added to glimepiride. Liraglutide 0.6 mg was less effective (-0.6%, baseline 8.4%). Fasting plasma glucose decreased by week 2, with a 1.6 mmol/l decrease from baseline at week 26 with liraglutide 1.2 mg (baseline 9.8 mmol/l) or 1.8 mg (baseline 9.7 mmol/l) compared with a 0.9 mmol/l increase (placebo, P < 0.0001, baseline 9.5 mmol/l) or 1.0 mmol/l decrease (rosiglitazone, P < 0.006, baseline 9.9 mmol/l). Decreases in postprandial plasma glucose from baseline were greater with liraglutide 1.2 or 1.8 mg [-2.5 to -2.7 mmol/l (baseline 12.9 mmol/l for both)] compared with placebo (-0.4 mmol/l, P < 0.0001, baseline 12.7 mmol/l) or rosiglitazone (-1.8 mmol/l, P < 0.05, baseline 13.0 mmol/l). Changes in body weight with liraglutide 1.8 mg (-0.2 kg, baseline 83.0 kg), 1.2 mg (+0.3 kg, baseline 80.0 kg) or placebo (-0.1 kg, baseline 81.9 kg) were less than with rosiglitazone (+2.1 kg, P < 0.0001, baseline 80.6 kg). Main adverse events for all treatments were minor hypoglycaemia (< 10%), nausea (< 11%), vomiting (< 5%) and diarrhoea (< 8%).. Liraglutide added to glimepiride was well tolerated and provided improved glycaemic control and favourable weight profile. Topics: Aged; Blood Glucose; Body Weight; Diabetes Mellitus, Type 2; Double-Blind Method; Drug Therapy, Combination; Female; Glucagon-Like Peptide 1; Humans; Hypoglycemia; Hypoglycemic Agents; Male; Middle Aged; Rosiglitazone; Sulfonylurea Compounds; Thiazolidinediones | 2009 |
Adding liraglutide to oral antidiabetic drug monotherapy: efficacy and weight benefits.
To examine the options for add-on therapy in patients with type 2 diabetes whose disease is no longer adequately controlled by lifestyle interventions and oral antidiabetic drug (OAD)monotherapy.. This analysis included a subset of patients receiving prior OAD monotherapy from 2 phase 3, 26-week, randomized, double-blind, double-dummy, active-control, parallel-group, multicenter, multinational trials. Prior to randomization, patients not already receiving either metformin or glimepiride were switched to monotherapy with one of these drugs, and the dose was titrated to defined targets. Patients were then randomized to liraglutide (1.8 mg, 1.2 mg, or 0.6 mg once daily), placebo (OAD monotherapy plus placebo), or active comparator (rosiglitazone or glimepiride). For this analysis, only the liraglutide 1.8-mg dose was included. The primary outcome measure was change in glycosylated hemoglobin (HbA1c) from baseline. Secondary endpoints included in this analysis are percentage of patients achieving HbA1c < 7%, change in fasting plasma glucose, systolic blood pressure, body weight, beta-cell function, hypoglycemic episodes, and nausea.. There was a significant reduction in HbA1c in patients previously treated with OAD monotherapy (P < 0.0001) and significantly more patients achieved HbA1c < 7% (P = 0.0005) with the addition of liraglutide than with rosiglitazone. In addition, rosiglitazone plus glimepiride was associated with significantly more weight gain (P < 0.0001) than liraglutide plus glimepiride (P = 0.04). For patients on metformin monotherapy, the addition of liraglutide or glimepiride resulted in similar levels of glycemic control; however, patients receiving glimepiride had significantly greater weight gain (P < 0.0001) and higher rates of minor hyperglycemia.. Given the combination of effective glycemic control and weight benefits, liraglutide is a good option for early add-on therapy for patients on OAD monotherapy. Topics: Administration, Oral; Blood Glucose; Body Weight; Diabetes Mellitus, Type 2; Dose-Response Relationship, Drug; Double-Blind Method; Drug Therapy, Combination; Female; Follow-Up Studies; Glucagon-Like Peptide 1; Glycated Hemoglobin; Humans; Hypoglycemic Agents; Liraglutide; Male; Middle Aged; Treatment Outcome | 2009 |
Liraglutide once a day versus exenatide twice a day for type 2 diabetes: a 26-week randomised, parallel-group, multinational, open-label trial (LEAD-6).
Unlike most antihyperglycaemic drugs, glucagon-like peptide-1 (GLP-1) receptor agonists have a glucose-dependent action and promote weight loss. We compared the efficacy and safety of liraglutide, a human GLP-1 analogue, with exenatide, an exendin-based GLP-1 receptor agonist.. Adults with inadequately controlled type 2 diabetes on maximally tolerated doses of metformin, sulphonylurea, or both, were stratified by previous oral antidiabetic therapy and randomly assigned to receive additional liraglutide 1.8 mg once a day (n=233) or exenatide 10 microg twice a day (n=231) in a 26-week open-label, parallel-group, multinational (15 countries) study. The primary outcome was change in glycosylated haemoglobin (HbA(1c)). Efficacy analyses were by intention to treat. The trial is registered with ClinicalTrials.gov, number NCT00518882.. Mean baseline HbA(1c) for the study population was 8.2%. Liraglutide reduced mean HbA(1c) significantly more than did exenatide (-1.12% [SE 0.08] vs -0.79% [0.08]; estimated treatment difference -0.33; 95% CI -0.47 to -0.18; p<0.0001) and more patients achieved a HbA(1c) value of less than 7% (54%vs 43%, respectively; odds ratio 2.02; 95% CI 1.31 to 3.11; p=0.0015). Liraglutide reduced mean fasting plasma glucose more than did exenatide (-1.61 mmol/L [SE 0.20] vs -0.60 mmol/L [0.20]; estimated treatment difference -1.01 mmol/L; 95% CI -1.37 to -0.65; p<0.0001) but postprandial glucose control was less effective after breakfast and dinner. Both drugs promoted similar weight losses (liraglutide -3.24 kg vs exenatide -2.87 kg). Both drugs were well tolerated, but nausea was less persistent (estimated treatment rate ratio 0.448, p<0.0001) and minor hypoglycaemia less frequent with liraglutide than with exenatide (1.93 vs 2.60 events per patient per year; rate ratio 0.55; 95% CI 0.34 to 0.88; p=0.0131; 25.5%vs 33.6% had minor hypoglycaemia). Two patients taking both exenatide and a sulphonylurea had a major hypoglycaemic episode.. Liraglutide once a day provided significantly greater improvements in glycaemic control than did exenatide twice a day, and was generally better tolerated. The results suggest that liraglutide might be a treatment option for type 2 diabetes, especially when weight loss and risk of hypoglycaemia are major considerations.. Novo Nordisk A/S. Topics: Analysis of Variance; Blood Glucose; Diabetes Mellitus, Type 2; Dose-Response Relationship, Drug; Drug Administration Schedule; Exenatide; Female; Glucagon-Like Peptide 1; Glycated Hemoglobin; Humans; Hypoglycemia; Hypoglycemic Agents; Injections, Subcutaneous; Linear Models; Liraglutide; Logistic Models; Male; Middle Aged; Nausea; Peptides; Treatment Outcome; Venoms; Weight Loss | 2009 |
Efficacy of a continuous GLP-1 infusion compared with a structured insulin infusion protocol to reach normoglycemia in nonfasted type 2 diabetic patients: a clinical pilot trial.
Continuously administered insulin is limited by the need for frequent blood glucose measurements, dose adjustments, and risk of hypoglycemia. Regimens based on glucagon-like peptide 1 (GLP-1) could represent a less complicated treatment alternative. This alternative might be advantageous in hyperglycemic patients hospitalized for acute critical illnesses, who benefit from near normoglycemic control.. In a prospective open randomized crossover trial, we investigated eight clinically stable type 2 diabetic patients during intravenous insulin or GLP-1 regimens to normalize blood glucose after a standardized breakfast.. The time to reach a plasma glucose below 115 mg/dl was significantly shorter during GLP-1 administration (252 +/- 51 vs. 321 +/- 43 min, P < 0.01). Maximum glycemia (312 +/- 51 vs. 254 +/- 48 mg/dl, P < 0.01) and glycemia after 2 h (271 +/- 51 vs. 168 +/- 48 mg/dl, P = 0.012) and after 4 h (155 +/- 51 vs. 116 +/- 27 mg/dl, P = 0.02) were significantly lower during GLP-1 administration.. GLP-1 infusion is superior to an established insulin infusion regimen with regard to effectiveness and practicability. Topics: Cross-Over Studies; Diabetes Mellitus, Type 2; Female; Glucagon-Like Peptide 1; Humans; Hypoglycemic Agents; Incretins; Insulin; Male; Middle Aged | 2009 |
Effects of a protein preload on gastric emptying, glycemia, and gut hormones after a carbohydrate meal in diet-controlled type 2 diabetes.
We evaluated whether a whey preload could slow gastric emptying, stimulate incretin hormones, and attenuate postprandial glycemia in type 2 diabetes.. Eight type 2 diabetic patients ingested 350 ml beef soup 30 min before a potato meal; 55 g whey was added to either the soup (whey preload) or potato (whey in meal) or no whey was given.. Gastric emptying was slowest after the whey preload (P < 0.0005). The incremental area under the blood glucose curve was less after the whey preload and whey in meal than after no whey (P < 0.005). Plasma glucose-dependent insulinotropic polypeptide, insulin, and cholecystokinin concentrations were higher on both whey days than after no whey, whereas glucagon-like peptide 1 was greatest after the whey preload (P < 0.05).. Whey protein consumed before a carbohydrate meal can stimulate insulin and incretin hormone secretion and slow gastric emptying, leading to marked reduction in postprandial glycemia in type 2 diabetes. Topics: Blood Glucose; Cholecystokinin; Diabetes Mellitus, Type 2; Dietary Proteins; Female; Gastric Emptying; Gastrointestinal Hormones; Glucagon-Like Peptide 1; Humans; Insulin; Male; Middle Aged | 2009 |
Potential of albiglutide, a long-acting GLP-1 receptor agonist, in type 2 diabetes: a randomized controlled trial exploring weekly, biweekly, and monthly dosing.
To evaluate the efficacy, safety, and tolerability of incremental doses of albiglutide, a long-acting glucagon-like peptide-1 receptor agonist, administered with three dosing schedules in patients with type 2 diabetes inadequately controlled with diet and exercise or metformin monotherapy.. In this randomized multicenter double-blind parallel-group study, 356 type 2 diabetic subjects with similar mean baseline characteristics (age 54 years, diabetes duration 4.9 years, BMI 32.1 kg/m(2), A1C 8.0%) received subcutaneous placebo or albiglutide (weekly [4, 15, or 30 mg], biweekly [15, 30, or 50 mg], or monthly [50 or 100 mg]) or exenatide twice daily as an open-label active reference (per labeling in metformin subjects only) over 16 weeks followed by an 11-week washout period. The main outcome measure was change from baseline A1C of albiglutide groups versus placebo at week 16.. Dose-dependent reductions in A1C were observed within all albiglutide schedules. Mean A1C was similarly reduced from baseline by albiglutide 30 mg weekly, 50 mg biweekly (every 2 weeks), and 100 mg monthly (-0.87, -0.79, and -0.87%, respectively) versus placebo (-0.17%, P < 0.004) and exenatide (-0.54%). Weight loss (-1.1 to -1.7 kg) was observed with these three albiglutide doses with no significant between-group effects. The incidence of gastrointestinal adverse events in subjects receiving albiglutide 30 mg weekly was less than that observed for the highest biweekly and monthly doses of albiglutide or exenatide.. Weekly albiglutide administration significantly improved glycemic control and elicited weight loss in type 2 diabetic patients, with a favorable safety and tolerability profile. Topics: Diabetes Mellitus, Type 2; Double-Blind Method; Drug Administration Schedule; Glucagon-Like Peptide 1; Glucagon-Like Peptide-1 Receptor; Humans; Hypoglycemic Agents; Multicenter Studies as Topic; Placebo Effect; Receptors, Glucagon; Treatment Outcome | 2009 |
Liraglutide vs insulin glargine and placebo in combination with metformin and sulfonylurea therapy in type 2 diabetes mellitus (LEAD-5 met+SU): a randomised controlled trial.
The aim of the study was to compare the efficacy and safety of liraglutide in type 2 diabetes mellitus vs placebo and insulin glargine (A21Gly,B31Arg,B32Arg human insulin), all in combination with metformin and glimepiride.. This randomised (using a telephone or web-based randomisation system), parallel-group, controlled 26 week trial of 581 patients with type 2 diabetes mellitus on prior monotherapy (HbA(1c) 7.5-10%) and combination therapy (7.0-10%) was conducted in 107 centres in 17 countries. The primary endpoint was HbA(1c). Patients were randomised (2:1:2) to liraglutide 1.8 mg once daily (n = 232), liraglutide placebo (n = 115) and open-label insulin glargine (n = 234), all in combination with metformin (1 g twice daily) and glimepiride (4 mg once daily). Investigators, participants and study monitors were blinded to the treatment status of the liraglutide and placebo groups at all times.. The number of patients analysed as intention to treat were: liraglutide n = 230, placebo n = 114, insulin glargine n = 232. Liraglutide reduced HbA(1c) significantly vs glargine (1.33% vs 1.09%; -0.24% difference, 95% CI 0.08, 0.39; p = 0.0015) and placebo (-1.09% difference, 95% CI 0.90, 1.28; p < 0.0001). There was greater weight loss with liraglutide vs placebo (treatment difference -1.39 kg, 95% CI 2.10, 0.69; p = 0.0001), and vs glargine (treatment difference -3.43 kg, 95% CI 4.00, 2.86; p < 0.0001). Liraglutide reduced systolic BP (-4.0 mmHg) vs glargine (+0.5 mmHg; -4.5 mmHg difference, 95% CI 6.8, -2.2; p = 0.0001) but not vs placebo (p = 0.0791). Rates of hypoglycaemic episodes (major, minor and symptoms only, respectively) were 0.06, 1.2 and 1.0 events/patient/year, respectively, in the liraglutide group (vs 0, 1.3, 1.8 and 0, 1.0, 0.5 with glargine and placebo, respectively). A slightly higher number of adverse events (including nausea at 14%) were reported with liraglutide, but only 9.8% of participants in the group receiving liraglutide developed anti-liraglutide antibodies.. Liraglutide added to metformin and sulfonylurea produced significant improvement in glycaemic control and bodyweight compared with placebo and insulin glargine. The difference vs insulin glargine in HbA(1c) was within the predefined non-inferiority margin.. ClinicalTrials.gov NCT00331851.. The study was funded by Novo Nordisk A/S. Topics: Adolescent; Adult; Aged; Aged, 80 and over; Blood Glucose; Body Weight; Diabetes Mellitus, Type 2; Drug Therapy, Combination; Female; Glucagon-Like Peptide 1; Humans; Hypoglycemic Agents; Insulin; Insulin Glargine; Insulin, Long-Acting; Liraglutide; Male; Metformin; Middle Aged; Placebos; Sulfonylurea Compounds; Young Adult | 2009 |
Absence of QTc prolongation in a thorough QT study with subcutaneous liraglutide, a once-daily human GLP-1 analog for treatment of type 2 diabetes.
The objective of this study was to establish effects of liraglutide on the QTc interval. In this randomized, placebo-controlled, double-blind crossover study, 51 healthy participants were administered placebo, 0.6, 1.2, and 1.8 mg liraglutide once daily for 7 days each. Electrocardiograms were recorded periodically over 24 hours at the end of placebo and highest dosing periods. Four different models for QT correction were used: QTci, as the primary endpoint, and QTciL, QTcF, and QTcB as secondary endpoints. The upper bound of the 1-sided 95% confidence interval for time-matched, baseline-corrected, placebo-subtracted QTc intervals was <10 ms for all 4 correction methods. Moxifloxacin (400 mg) increased QTc intervals by 10.6 to 12.3 ms at 2 hours. There was no concentration-exposure dependency on QTc interval changes by liraglutide and no QTc thresholds above 500 ms or QTc increases >60 ms. The authors conclude that liraglutide caused no clinically relevant increases in the QTc interval. Topics: Adolescent; Adult; Aza Compounds; Cross-Over Studies; Diabetes Mellitus, Type 2; Dose-Response Relationship, Drug; Drug Evaluation, Preclinical; Electrocardiography; Female; Fluoroquinolones; Glucagon-Like Peptide 1; Heart Conduction System; Humans; Injections, Subcutaneous; Liraglutide; Male; Middle Aged; Models, Statistical; Moxifloxacin; Quinolines; Time Factors | 2009 |
Preserved inhibitory potency of GLP-1 on glucagon secretion in type 2 diabetes mellitus.
Glucagon-like peptide-1 (GLP-1) is insulinotropic, but its effect on the alpha-cell is less clear. We investigated the dose-response relationship for GLP-1-induced glucagon suppression in patients with type 2 diabetes (T2DM) and healthy controls.. Ten patients with T2DM (duration of DM, 4 +/- 1 yr; glycosylated hemoglobin, 7.1 +/- 0.3%) were studied on 2 d, with stepwise increasing GLP-1 infusions (0.25, 0.5, 1.0, and 2.0 pmol x kg(-1) x min(-1)) (d 1) or saline (d 2) with plasma glucose (PG) clamped at fasting level. On d 3, patient PG was normalized overnight using a variable insulin infusion, followed by a 3-h GLP-1 infusion as on d 1. Ten healthy subjects were examined with the same protocol on d 1 and 2.. We observed similar dose-dependent stepwise suppression of glucagon secretion in both patients and controls. Significant suppression was observed at a GLP-1 infusion rate of 0.25 pmol x kg(-1) x min(-1) (resulting in physiological plasma concentrations) as early as time 15 min in healthy controls and time 30 min in patients (d 1 and d 3). AUC for glucagon was significantly reduced on d 1 and 3 (1096 +/- 109 and 1116 +/- 108 3h x pmol/liter; P = NS) as compared to d 2 (1733 +/- 193 3h x pmol/liter; P < 0.01) in patients with T2DM. A similar reduction in AUC for glucagon was observed in healthy controls [1122 +/- 186 (d 1) vs. 1733 +/- 312 3h x pmol/liter (d 2); P < 0.001].. The diabetic alpha-cell appears to be highly sensitive to the inhibitory action of GLP-1 both during high and near-normalized PG levels, but responds with a short, nevertheless significant delay. Topics: Blood Glucose; C-Peptide; Diabetes Mellitus, Type 2; Dose-Response Relationship, Drug; Female; Glucagon; Glucagon-Like Peptide 1; Glucagon-Secreting Cells; Glucose Tolerance Test; Humans; Infusions, Intravenous; Insulin; Male; Middle Aged | 2009 |
Safety, tolerability, pharmacokinetics and pharmacodynamics of albiglutide, a long-acting GLP-1-receptor agonist, in Japanese subjects with type 2 diabetes mellitus.
To investigate safety, pharmacokinetics and pharmacodynamics of albiglutide in Japanese subjects with type 2 diabetes mellitus.. This randomized, single-blind, placebo-controlled study examined four doses/dose schedules of subcutaneously (sc) administered albiglutide: 15 mg weekly, 30 mg weekly, 50 mg biweekly, and 100 mg monthly (cohorts A-D, respectively) in 40 subjects (mean age 54.5 years, mean range of glycosylated hemoglobin [HbA(1c)] 7.1-8.3%), over a 4-week treatment period.. Safety parameters, including adverse events, clinical laboratory tests, vital signs, and 12-lead electrocardiogram; plasma concentrations of albiglutide; and pharmacodynamic parameters, including change from baseline and weighted mean AUC(0-4) in plasma glucose, glucagon, insulin, and C-peptide levels.. NCT00530309.. At day 29, mean changes from baseline (vs. placebo) in fasting plasma glucose (FPG) were: cohort A, -1.92 mmol/L; B, -1.98 mmol/L; C, -1.74 mmol/L; D, -0.73 mmol/L; changes in weighted mean glucose AUC(0-4) were: cohort A, -2.86 mmol/L; B, -3.58 mmol/L; C, -2.51 mmol/L; D, -1.44 mmol/L (for FPG and AUC(0-4), all p < or = 0.002 except 100 mg sc monthly, p = NS); changes from baseline HbA(1c) were: cohort A, -0.58%; B, -0.57%; C, -0.63%; and D, -0.51% (all p < 0.03). Albiglutide sc had a median half-life of 5.3 days, plasma apparent systemic clearance of 68.7 mL/h, and apparent volume of distribution of 12.6 L. Incidence of adverse events was low and comparable to sc placebo in all albiglutide treatment arms except 100 mg sc monthly, where gastrointestinal (GI) adverse events were most common. Limitations of this study include the small sample size, short treatment duration, and enrollment of predominantly male subjects.. Weekly and biweekly albiglutide improved glycemic control and were well-tolerated in Japanese subjects with type 2 diabetes mellitus. Topics: Adult; Aged; Algorithms; Asian People; Delayed-Action Preparations; Diabetes Mellitus, Type 2; Dose-Response Relationship, Drug; Drug Administration Schedule; Female; Glucagon-Like Peptide 1; Glucagon-Like Peptide-1 Receptor; Humans; Hypoglycemic Agents; Male; Middle Aged; Placebos; Receptors, Glucagon; Single-Blind Method | 2009 |
A simulation of the comparative long-term effectiveness of liraglutide and glimepiride monotherapies in patients with type 2 diabetes mellitus.
To project and compare long-term outcomes of morbidity and mortality, and costs of complications of type 2 diabetes mellitus from a randomized controlled trial of patients receiving liraglutide versus glimepiride monotherapy.. Mathematic simulation using the validated Center for Outcomes Research (CORE) Diabetes Model, calibrated to baseline patient characteristics from a short-term, randomized, controlled trial of liraglutide and glimepiride monotherapies (Liraglutide Effect and Action in Diabetes [LEAD]-3 trial) and using data from long-term outcomes studies.. Simulated routine clinical practice.. Seven hundred forty-six patients with type 2 diabetes who participated in the LEAD-3 trial, and three hypothetical cohorts of 5000 patients each that were based on the baseline characteristics of the patients in the LEAD-3 trial. The patients in the LEAD-3 trial were randomly assigned to monotherapy with liraglutide 1.2 mg/day (251 patients), liraglutide 1.8 mg/day (247 patients), or glimepiride 8 mg/day (248 patients).. The impact of the three treatments for type 2 diabetes on survival and cumulative incidence of cardiovascular, ocular, or renal events and costs were estimated at three time periods: 10, 20, and 30 years. Simulations predicted improved survival for liraglutide 1.8 and 1.2 mg at all three time points compared with glimepiride. Survival benefits were greatest after 30 years of follow-up: 16.5%, 13.6%, and 7.3%, respectively. The frequency of nonfatal renal and ocular events was lower for both liraglutide doses than for glimepiride. The rate of neuropathies leading to first or recurrent amputation was higher for glimepiride compared with both liraglutide doses. The average cumulative cost/patient was higher for glimepiride compared with liraglutide 1.2 mg and liraglutide 1.8 mg.. With use of the CORE Diabetes Model and data from the LEAD-3 trial, long-term projected survival, diabetes complications, and costs favored liraglutide 1.2- and 1.8-mg monotherapies compared with glimepiride in the treatment of type 2 diabetes. Topics: Blood Glucose; Blood Pressure; Cohort Studies; Computer Simulation; Diabetes Mellitus, Type 2; Dose-Response Relationship, Drug; Double-Blind Method; Drug Therapy, Combination; Female; Follow-Up Studies; Glucagon-Like Peptide 1; Glycated Hemoglobin; Humans; Hypoglycemic Agents; Liraglutide; Male; Models, Theoretical; Morbidity; Sulfonylurea Compounds; Survival Analysis; Time Factors; Treatment Outcome | 2009 |
Pharmacokinetic and pharmacodynamic properties of taspoglutide, a once-weekly, human GLP-1 analogue, after single-dose administration in patients with Type 2 diabetes.
The study objectives were to evaluate the pharmacokinetic and pharmacodynamic properties, as well as safety and tolerability, of single doses of taspoglutide, a human glucagon-like peptide-1 (GLP-1) analogue.. In a double-blind, placebo-controlled study, 48 patients with Type 2 diabetes [mean age 56 +/- 7 years; mean body mass index (BMI) 30.4 +/- 3.0 kg/m(2)] inadequately controlled with metformin (< or = 2 g/day) were enrolled in three sequential cohorts; 12 patients in each cohort were randomized to a single subcutaneous injection of taspoglutide (1, 8 or 30 mg) and four received placebo.. Plasma concentrations peaked within 24 h after injection and were sustained for > or = 14 days with all doses. In comparison with placebo, the 8- and 30-mg doses of taspoglutide significantly reduced glycaemic parameters, including 24-h blood glucose and 5-h postprandial glucose areas under the curve (AUCs), for up to 14 days with the 30-mg dose (P < 0.001). The most common adverse events, primarily gastrointestinal in nature, were dose-dependent and transient.. A single dose of taspoglutide significantly improved glycaemic parameters in Type 2 diabetes patients for up to 14 days. The formulation was well tolerated and appears suitable for weekly administration. Topics: Delayed-Action Preparations; Diabetes Mellitus, Type 2; Dose-Response Relationship, Drug; Double-Blind Method; Drug Administration Schedule; Female; Glucagon-Like Peptide 1; Humans; Hypoglycemic Agents; Injections, Subcutaneous; Male; Middle Aged; Peptides; Treatment Outcome | 2009 |
Weight loss with liraglutide, a once-daily human glucagon-like peptide-1 analogue for type 2 diabetes treatment as monotherapy or added to metformin, is primarily as a result of a reduction in fat tissue.
The effect on body composition of liraglutide, a once-daily human glucagon-like peptide-1 analogue, as monotherapy or added to metformin was examined in patients with type 2 diabetes (T2D).. These were randomized, double-blind, parallel-group trials of 26 [Liraglutide Effect and Action in Diabetes-2 (LEAD-2)] and 52 weeks (LEAD-3). Patients with T2D, aged 18-80 years, body mass index (BMI) < or =40 kg/m(2) (LEAD-2), < or =45 kg/m(2) (LEAD-3) and HbA1c 7.0-11.0% were included. Patients were randomized to liraglutide 1.8, 1.2 or 0.6 mg/day, placebo or glimepiride 4 mg/day, all combined with metformin 1.5-2 g/day in LEAD-2 and to liraglutide 1.8, 1.2 or glimepiride 8 mg/day in LEAD-3. LEAD-2/3: total lean body tissue, fat tissue and fat percentage were measured. LEAD-2: adipose tissue area and hepatic steatosis were assessed.. LEAD-2: fat percentage with liraglutide 1.2 and 1.8 mg/metformin was significantly reduced vs. glimepiride/metformin (p < 0.05) but not vs. placebo. Visceral and subcutaneous adipose tissue areas were reduced from baseline in all liraglutide/metformin arms. Except with liraglutide 0.6 mg/metformin, reductions were significantly different vs. changes seen with glimepiride (p < 0.05) but not with placebo. Liver-to-spleen attenuation ratio increased with liraglutide 1.8 mg/metformin possibly indicating reduced hepatic steatosis. LEAD-3: reductions in fat mass and fat percentage with liraglutide monotherapy were significantly different vs. increases with glimepiride (p < 0.01).. Liraglutide (monotherapy or added to metformin) significantly reduced fat mass and fat percentage vs. glimepiride in patients with T2D. Topics: Adolescent; Adult; Aged; Aged, 80 and over; Body Composition; Body Weight; Delayed-Action Preparations; Diabetes Mellitus, Type 2; Double-Blind Method; Female; Glucagon-Like Peptide 1; Glycated Hemoglobin; Humans; Hypoglycemic Agents; Liraglutide; Male; Middle Aged; Sulfonylurea Compounds; Treatment Outcome; Weight Loss; Young Adult | 2009 |
Effect of renal impairment on the pharmacokinetics of the GLP-1 analogue liraglutide.
* Patients with Type 2 diabetes are likely to have or to develop renal impairment, which affects the pharmacokinetics of some antidiabetic treatments. * Whether dosing of the once-daily human glucagon-like peptide-1 analogue liraglutide should be modified in patients with renal impairment has not previously been studied.. * Renal dysfunction was not found to increase the exposure of liraglutide. * Hence, no dose adjustment is expected to be required in patients with Type 2 diabetes and renal impairment treated with liraglutide.. To investigate whether dose adjustment of the once-daily human glucagon-like peptide-1 analogue liraglutide is required in patients with varying stages of renal impairment.. A cohort of 30 subjects, of whom 24 had varying degrees of renal impairment and six had normal renal function, were given a single dose of liraglutide, 0.75 mg subcutaneously, and completed serial blood sampling for plasma liraglutide measurements for pharmacokinetic estimation.. No clear trend for change in pharmacokinetics was evident across groups with increasing renal dysfunction. While the between-group comparisons of the area under the liraglutide concentration-curve (AUC) did not demonstrate equivalence [estimated ratio AUC(severe)/AUC(healthy) 0.73, 90% confidence interval (CI) 0.57, 0.94; and AUC (continuous ambulatory peritoneal dialysis)(CAPD)/AUC(healthy) 0.74, 90% CI 0.56, 0.97], the regression analysis of log(AUC) for subjects with normal renal function and mild-to-severe renal impairment showed no significant effect of decreasing creatinine clearance on the pharmacokinetics of liraglutide. The expected AUC ratio between the two subjects with the lowest and highest creatinine clearance in the study was estimated to be 0.88 (95% CI 0.58, 1.34) (NS). Degree of renal impairment did not appear to be associated with an increased risk of adverse events.. This study indicated no safety concerns regarding use of liraglutide in patients with renal impairment. Renal dysfunction was not found to increase exposure of liraglutide, and patients with Type 2 diabetes and renal impairment should use standard treatment regimens of liraglutide. There is, however, currently limited experience with liraglutide in patients beyond mild-stage renal disease. Topics: Adolescent; Adult; Aged; Aged, 80 and over; Area Under Curve; Diabetes Mellitus, Type 2; Diabetic Nephropathies; Dose-Response Relationship, Drug; Female; Glucagon-Like Peptide 1; Humans; Incretins; Kidney; Liraglutide; Male; Middle Aged; New Zealand; Young Adult | 2009 |
Tolerability, pharmacokinetics and pharmacodynamics of the once-daily human GLP-1 analog liraglutide in Japanese healthy subjects: a randomized, double-blind, placebo-controlled dose-escalation study.
Liraglutide is a once-daily human GLP-1 analog being developed as a Type 2 diabetes therapy. A dose-finding study in Japanese patients with Type 2 diabetes showed liraglutide to produce dose-dependent decreases in HbA(1C). Studies have also shown that, with stepped dose titration, liraglutide is well tolerated. This double-blind trial in 24 healthy Japanese men assessed the safety, tolerability, pharmacokinetics and pharmacodynamics of once-daily subcutaneous (s.c.) liraglutide using doses exceeding those previously studied, and using the stepped titration approach.. Subjects were randomized to three groups in each of which 6 received liraglutide, and 2 placebo for 35 consecutive days. The daily dose of liraglutide was stepped from 5 microg/kg (s.c. abdomen, morning) to 10 and then 15 microg/kg at 7-day intervals. One group remained at this dose, the others titrating further to 20 and 25 microg/kg, respectively. Subjects remained at the study site from Day 21 until the end of the trial, with standard meals served during inhouse periods.. No safety issues, hypoglycemia, gastrointestinal or any other adverse events were observed. Liraglutide showed dose-dependent increases in the pharmacokinetic parameters of AUC0-24 h, C(max) and C(trough), while t(max), t(1/2) and V(d/F) were constant. Mean plasma glucose concentrations were similar across all treatment groups at baseline, but dose-dependent decreases in mean and postprandial plasma glucose were seen with liraglutide, although all values remained within normal ranges. There was a tendency for weight to decrease with liraglutide in comparison to placebo.. Liraglutide appears to be well tolerated at doses of up to 25 microg/kg in Japanese subjects. Despite clear pharmacodynamic effects in this euglycemic cohort, a low risk for hypoglycemia was suggested together with good gastrointestinal tolerability. Topics: Adult; Area Under Curve; Blood Glucose; Diabetes Mellitus, Type 2; Dose-Response Relationship, Drug; Double-Blind Method; Glucagon-Like Peptide 1; Half-Life; Humans; Hypoglycemic Agents; Injections, Subcutaneous; Japan; Liraglutide; Male; Middle Aged; Tissue Distribution; Weight Loss | 2008 |
Efficacy and safety of exenatide administered before the two largest daily meals of Latin American patients with type 2 diabetes.
To evaluate whether exenatide administered before breakfast and dinner (BD) or before lunch and dinner (LD) provided similar glycemic control in Latin American patients with type 2 diabetes mellitus (T2DM) who consume a small breakfast.. In this open-label, 2-arm study, patients taking metformin, sulfonylureas, and/or thiazolidinediones were randomized to exenatide before BD or before LD (5-mug exenatide for 4 weeks, then 10-microg exenatide for 8 weeks). Treatment assignment was determined by a computer-generated random sequence using an interactive response system. Patients were eligible for study inclusion if they consumed <15% of their total caloric intake at breakfast. The primary endpoint was HbA(1c) change from baseline to endpoint. Secondary endpoints included fasting serum glucose (FSG) level, 7-point SMBG profile, and safety. Clinicaltrials.gov Identifier: NCT00359879.. 377 participants (55% female, age 54 +/- 10 years, weight 82 +/- 15 kg, BMI 31 +/- 4 kg/m(2), HbA(1c) 8.4 +/- 0.9%; mean +/- SD) from Brazil and Mexico were randomized to study treatment. HbA(1c) reduction with exenatide administration before BD was non-inferior to administration before LD (mean difference between (LD-BD) treatments: 0.14%; 95% CI -0.04 to 0.32%, p=0.120). Both treatments resulted in statistically significant HbA(1c) reductions at endpoint (BD -1.2% and LD -1.1%, respectively, p<0.001). In Brazil, the non-inferiority criteria were met for HbA(1c) reduction between treatment arms (-0.12%; CI -0.37 to 0.13%, p=0.344), whereas in Mexico, there was a difference favoring exenatide administration before BD (0.41%; CI 0.16 to 0.66%, p=0.002). At endpoint, there were no statistical significant differences between the BD and LD arms in mean change in FSG (0.50 mmol/L; CI -0.02 to 1.02 mmol/L, p=0.058) and daily mean change in SMBG (0.19 mmol/L; CI -0.17 to 0.54 mmol/L, p=0.295). The rates of symptomatic hypoglycemia (5.2 events/patient-year vs. 6.1 events/patient-year) and nausea (23% vs. 25%), were similar between the BD and LD arms, respectively. A limitation of the study design was that caloric intake of patients and meal times were not monitored.. In T2DM patients who consume a small breakfast, exenatide administration before breakfast or lunch resulted in significant improvement in glycemic control. Topics: Adult; Blood Glucose; Diabetes Mellitus, Type 2; Eating; Exenatide; Female; Glucagon-Like Peptide 1; Glycated Hemoglobin; Hispanic or Latino; Humans; Hypoglycemic Agents; Male; Middle Aged; Peptides; Venoms | 2008 |
Effect of two carbohydrate-modified tube-feeding formulas on metabolic responses in patients with type 2 diabetes.
This study evaluated the glycemic, insulinemic, and glucagon-like peptide-1 (GLP-1) responses of subjects with type 2 diabetes mellitus to consumption of two diabetes-specific tube-feeding formulas (slowly digested carbohydrate formula [SDC] and diabetes-specific formula [DSF]) and one formula intended for individuals without diabetes (standard formula [STND]).. Forty-eight subjects controlled with diet and/or oral antihyperglycemic medications received the SDC, DSF, and STND. Postprandial glucose, insulin, and GLP-1 were measured on three occasions after an overnight fast in a double-blinded, randomized, three-treatment, crossover design.. The positive area under the curve for glucose and insulin with the STND was higher (P < 0.001) compared with the SDC and DSF. The adjusted GLP-1 concentration at 60 min was higher for the SDC compared with the DSF and STND (P < 0.05).. Both lower-carbohydrate diabetes-specific formulas resulted in a lower postprandial blood glucose response compared with the STND. The formula also rich in slowly digested carbohydrate and monounsaturated and omega-3 fatty acids (SDC) produced significantly lower blood glucose and insulin responses and higher levels of GLP-1 in the presence of significantly lower insulin concentrations. These results support the view that the quantity and quality of carbohydrate and fat may play important roles in the management of patients with type 2 diabetes mellitus and could result in improved beta-cell function over the long term. Topics: Adolescent; Adult; Aged; Area Under Curve; Blood Glucose; Carbohydrate Metabolism; Cross-Over Studies; Diabetes Mellitus, Type 2; Dietary Carbohydrates; Dietary Fats, Unsaturated; Digestion; Double-Blind Method; Female; Food, Formulated; Glucagon-Like Peptide 1; Humans; Insulin; Male; Middle Aged; Treatment Outcome; Young Adult | 2008 |
Pharmacokinetics and tolerability of a novel long-acting glucagon-like peptide-1 analog, CJC-1131, in healthy and diabetic subjects.
The safety, tolerability, pharmacokinetics and preliminary pharmacodynamics of single rising doses of a novel GLP-1 analog, CJC-1131, was evaluated.. CJC-1131 was subcutaneously injected in 8 groups (1.5 - 20.5 microg/kg) of healthy subjects (each group of six subjects included 1 placebo per dose level). CJC-1131 was also injected subcutaneously in 6 groups (1.5 - 12 microg/kg) of Type 2 diabetic patients after a 9-day washout period from their own anti-diabetic medication. Each group of 8 patients included 2 placebo-treated patients. Seven blood glucose measurements were taken daily, and meal tolerance tests were performed on the day before dosing and on Day 3.. CJC-1131 was quickly absorbed from the subcutaneous space, and a less than dose-proportional increase was found in Cmax. The half-life of CJC-1131 varied from 8.9 - 14.7 days in healthy subjects and from 9.1 - 13.8 days in patients. The maximum tolerated dose in healthy subjects was established at 12 microg/kg with nausea and vomiting being the dose-limiting events. These events occurred generally in the morning after dosing. Blood glucose levels in patients decreased on Day 1 in proportion with dose, with a maximum average decrease of 4.1 mmol/l in the highest dose group. Higher doses appeared to be related to a slight weight loss in patients.. Conjugation to albumin led to a major prolongation of the half-life of GLP-1. The tolerability of this potential antidiabetic drug seems to be limited only by gastrointestinal complaints. Topics: Adult; Aged; Blood Glucose; Diabetes Mellitus, Type 2; Dose-Response Relationship, Drug; Double-Blind Method; Female; Glucagon-Like Peptide 1; Half-Life; Humans; Hypoglycemic Agents; Injections, Subcutaneous; Male; Maleimides; Maximum Tolerated Dose; Middle Aged; Nausea; Peptides; Protein Binding; Serum Albumin; Vomiting | 2008 |
Pharmacodynamics, pharmacokinetics, safety, and tolerability of albiglutide, a long-acting glucagon-like peptide-1 mimetic, in patients with type 2 diabetes.
Native glucagon-like peptide-1 increases insulin secretion, decreases glucagon secretion, and reduces appetite but is rapidly inactivated by dipeptidyl peptidase-4. Albiglutide is a novel dipeptidyl peptidase-4-resistant glucagon-like peptide-1 dimer fused to human albumin designed to have sustained efficacy in vivo.. The objectives were to investigate pharmacodynamics, pharmacokinetics, safety, and tolerability of albiglutide in type 2 diabetes subjects.. In a single-blind dose-escalation study, 54 subjects were randomized to receive placebo or 9-, 16-, or 32-mg albiglutide on d 1 and 8. In a complementary study, 46 subjects were randomized to a single dose (16 or 64 mg) of albiglutide to the arm, leg, or abdomen.. Significant dose-dependent reductions in 24-h mean weighted glucose [area under the curve((0-24 h))] were observed, with placebo-adjusted least squares means difference values in the 32-mg cohort of -34.8 and -56.4 mg/dl [95% confidence interval (-54.1, -15.5) and (-82.2, -30.5)] for d 2 and 9, respectively. Placebo-adjusted fasting plasma glucose decreased by -26.7 and -50.7 mg/dl [95% confidence interval (-46.3, -7.06) and (-75.4, -26.0)] on d 2 and 9, respectively. Postprandial glucose was also reduced. No hypoglycemic episodes were detected in the albiglutide cohorts. The frequency and severity of the most common adverse events, headache and nausea, were comparable with placebo controls. Albiglutide half-life ranged between 6 and 7 d. The pharmacokinetics or pharmacodynamic of albiglutide was unaffected by injection site.. Albiglutide improved fasting plasma glucose and postprandial glucose with a favorable safety profile in subjects with type 2 diabetes. Albiglutide's long half-life may allow for once-weekly or less frequent dosing. Topics: Adolescent; Adult; Aged; Area Under Curve; Blood Glucose; Diabetes Mellitus, Type 2; Dose-Response Relationship, Drug; Female; Glucagon-Like Peptide 1; Glycated Hemoglobin; Half-Life; Humans; Hypoglycemic Agents; Injections, Intravenous; Male; Middle Aged; Molecular Mimicry; Young Adult | 2008 |
Beneficial effects of once-daily liraglutide, a human glucagon-like peptide-1 analogue, on cardiovascular risk biomarkers in patients with Type 2 diabetes.
Topics: Biomarkers; Blood Glucose; Diabetes Mellitus, Type 2; Diabetic Angiopathies; Drug Administration Schedule; Glucagon-Like Peptide 1; Humans; Hypoglycemic Agents; Liraglutide; Risk Factors | 2008 |
Measurements of islet function and glucose metabolism with the dipeptidyl peptidase 4 inhibitor vildagliptin in patients with type 2 diabetes.
Pharmacological inhibition with the dipeptidyl peptidase 4 (DPP-4) inhibitor vildagliptin prolongs the action of endogenously secreted incretin hormones leading to improved glycemic control in patients with type 2 diabetes mellitus (T2DM). We undertook a double-blinded, randomized-order, crossover study to examine the vildagliptin mechanisms of action on islet function and glucose utilization.. Participants with T2DM (n = 16) who had a baseline hemoglobin A(1c) of 7.1 +/- 0.2% completed a crossover study with 6 wk of treatment with vildagliptin and 6 wk with placebo. At the completion of each arm, participants had a study of postprandial metabolism and a two-step glucose clamp performed at 20 and 80 mU/min x m(2) insulin infusions.. Vildagliptin increased postprandial glucagon-like peptide-1 and glucose-dependent insulinotropic polypeptide by 3- and 2-fold, respectively, reduced fasting plasma glucose and postprandial plasma glucose by 1.3 +/- 0.3 mmol/liter and 1.6 +/- 0.3 mmol/liter (both P <0.01), and improved glucose responsiveness of insulin secretion by 50% (P < 0.01). Vildagliptin lowered postprandial glucagon by 16% (P <0.01). Examined by glucose clamp, insulin sensitivity and glucose clearance improved after vildagliptin (P < 0.01).. Vildagliptin improves islet function in T2DM and improves glucose metabolism in peripheral tissues. Topics: Adamantane; Blood Glucose; C-Reactive Protein; Cross-Over Studies; Diabetes Mellitus, Type 2; Dipeptidyl-Peptidase IV Inhibitors; Double-Blind Method; Female; Gastric Inhibitory Polypeptide; Glucagon-Like Peptide 1; Glucose; Humans; Insulin; Islets of Langerhans; Male; Middle Aged; Nitriles; Postprandial Period; Pyrrolidines; Vildagliptin | 2008 |
Efficacy and safety of sitagliptin added to ongoing metformin therapy in patients with type 2 diabetes.
The purpose of this study was to evaluate the efficacy and safety of sitagliptin as an add-on to metformin therapy in patients with moderately severe (hemoglobin A(1c) >or= 8.0% and Topics: Adult; Aged; Area Under Curve; Body Weight; Diabetes Mellitus, Type 2; Drug Therapy, Combination; Female; Glucagon-Like Peptide 1; Glycated Hemoglobin; Humans; Hypoglycemic Agents; Male; Metformin; Middle Aged; Pyrazines; Sitagliptin Phosphate; Treatment Outcome; Triazoles | 2008 |
Liraglutide, a once-daily human GLP-1 analogue, improves pancreatic B-cell function and arginine-stimulated insulin secretion during hyperglycaemia in patients with Type 2 diabetes mellitus.
To assess the effect of liraglutide, a once-daily human glucagon-like peptide-1 analogue on pancreatic B-cell function. methods: Patients with Type 2 diabetes (n = 39) were randomized to treatment with 0.65, 1.25 or 1.9 mg/day liraglutide or placebo for 14 weeks. First- and second-phase insulin release were measured by means of the insulin-modified frequently sampled intravenous glucose tolerance test. Arginine-stimulated insulin secretion was measured during a hyperglycaemic clamp (20 mmol/l). Glucose effectiveness and insulin sensitivity were estimated by means of the insulin-modified frequently sampled intravenous glucose tolerance test.. The two highest doses of liraglutide (1.25 and 1.9 mg/day) significantly increased first-phase insulin secretion by 118 and 103%, respectively (P < 0.05). Second-phase insulin secretion was significantly increased only in the 1.25 mg/day group vs. placebo. Arginine-stimulated insulin secretion increased significantly at the two highest dose levels vs. placebo by 114 and 94%, respectively (P < 0.05). There was no significant treatment effect on glucose effectiveness or insulin sensitivity.. Fourteen weeks of treatment with liraglutide showed improvements in first- and second-phase insulin secretion, together with improvements in arginine-stimulated insulin secretion during hyperglycaemia. Topics: C-Peptide; Diabetes Mellitus, Type 2; Drug Administration Schedule; Female; Glucagon-Like Peptide 1; Humans; Hypoglycemic Agents; Incretins; Insulin Resistance; Islets of Langerhans; Liraglutide; Male; Middle Aged; Receptors, Glucagon; Treatment Outcome | 2008 |
The effect of dipeptidyl peptidase-4 inhibition on gastric volume, satiation and enteroendocrine secretion in type 2 diabetes: a double-blind, placebo-controlled crossover study.
The incretin hormone glucagon-like peptide-1 (GLP-1) retards gastric emptying and decreases caloric intake. It is unclear whether increased GLP-1 concentrations achieved by inhibition of the inactivating enzyme dipeptidyl peptidase-4 (DPP-4) alter gastric volumes and satiation in people with type 2 diabetes.. In a double-blind, placebo-controlled crossover design, 14 subjects with type 2 diabetes received vildagliptin (50 mg bid) or placebo for 10 days in random order separated by a 2-week washout. On day 7, fasting and postmeal gastric volumes were measured by a (99m)Tc single-photon emission computed tomography (SPECT) method. On day 8, a liquid Ensure meal was consumed at 30 ml/min, and maximum tolerated volume (MTV) and symptoms 30 min later were measured using a visual analogue scale (VAS) to assess effects on satiation. On day 10, subjects ingested water until maximum satiation was achieved. The volume ingested was recorded and symptoms similarly measured using a VAS.. Vildagliptin raised plasma GLP-1 concentrations. However, fasting (248 +/- 21 vs. 247 +/- 19 ml, P = 0.98) and fed (746 +/- 28 vs. 772 +/- 26 ml, P = 0.54) gastric volumes did not differ when subjects received vildagliptin or placebo. Treatment with vildagliptin did not alter the MTV of Ensure (1657 +/- 308 vs. 1389 +/- 197 ml, P = 0.15) or water compared to placebo (1371 +/- 141 vs. 1172 +/- 156 ml, P = 0.23). Vildagliptin was associated with decreased peptide YY (PYY) concentrations 60 min after initiation of the meal (166 +/- 27 vs. 229 +/- 34 pmol/l, P = 0.01).. Vildagliptin does not alter satiation or gastric volume in people with type 2 diabetes despite elevated GLP-1 concentrations. Compensatory changes in enteroendocrine secretion could account for the lack of gastrointestinal symptoms. Topics: Adamantane; Cross-Over Studies; Diabetes Mellitus, Type 2; Dipeptidyl-Peptidase IV Inhibitors; Double-Blind Method; Drinking; Eating; Enteroendocrine Cells; Fasting; Gastric Emptying; Ghrelin; Glucagon-Like Peptide 1; Humans; Hypoglycemic Agents; Middle Aged; Nitriles; Organ Size; Placebos; Postprandial Period; Pyrrolidines; Satiation; Stomach; Vildagliptin | 2008 |
Patient-reported rating of gastrointestinal adverse effects during treatment of type 2 diabetes with the once-daily human GLP-1 analogue, liraglutide.
Topics: Diabetes Mellitus, Type 2; Dose-Response Relationship, Drug; Female; Gastrointestinal Diseases; Glucagon-Like Peptide 1; Humans; Incretins; Liraglutide; Male; Middle Aged | 2008 |
Dose-dependent improvement in glycemia with once-daily liraglutide without hypoglycemia or weight gain: A double-blind, randomized, controlled trial in Japanese patients with type 2 diabetes.
To evaluate dose-response efficacy and safety of once-daily human GLP-1 analog liraglutide in Japanese subjects with type 2 diabetes.. Patients (226, treated with diet with/without OADs, mean HbA(1c) 8.30%, mean BMI 23.9kg/m(2)) were randomized after OAD discontinuation and washout to receive liraglutide 0.1, 0.3, 0.6 or 0.9mg once daily, or placebo in double-blind, parallel-group design for 14 weeks.. Liraglutide dose levels reduced HbA(1c) versus placebo (by 0.79%, 1.22%, 1.64% and 1.85%, respectively; p<0.0001 for linear contrast). Liraglutide 0.9mg/day resulted in 75% of patients achieving HbA(1c) <7.0% and 57% achieving HbA(1c) <6.5%. There were no major or minor hypoglycemic events. Liraglutide also reduced, with significant dose-response (each p<0.0001 for linear contrast) versus placebo: fasting plasma glucose (up to 2.5mmol/L), postprandial (0-3h) glucose excursion (up to 12.8mmol/(Lh)); and increased postprandial insulin secretion (up to 23.0microU/(mLh)) and beta-cell function as evaluated by HOMA-beta (up to around 20.0(microU/mL)/(mg/dL)). Body weight was unchanged; no development of liraglutide antibodies was detected.. Liraglutide was highly effective and well tolerated at doses up to 0.9mg/day in Japanese patients with type 2 diabetes, allowing glycemic control without weight gain or hypoglycemia. Topics: Blood Glucose; Diabetes Mellitus, Type 2; Female; Glucagon-Like Peptide 1; Glycated Hemoglobin; Humans; Hypoglycemic Agents; Japan; Liraglutide; Male; Middle Aged; Postprandial Period; Safety | 2008 |
Vildagliptin does not affect C-peptide clearance in patients with type 2 diabetes.
Topics: Adamantane; Adult; Analysis of Variance; Blood Glucose; C-Peptide; Chromatography, Liquid; Diabetes Mellitus, Type 2; Dipeptidyl Peptidase 4; Dipeptidyl-Peptidase IV Inhibitors; Double-Blind Method; Female; Glucagon-Like Peptide 1; Humans; Hypoglycemic Agents; Insulin; Male; Middle Aged; Nitriles; Pyrrolidines; Radioimmunoassay; Tandem Mass Spectrometry; Time Factors; Vildagliptin | 2007 |
Glucagon-like peptide-1 (7-36) amide response to low versus high glycaemic index preloads in overweight subjects with and without type II diabetes mellitus.
Glucagon-like-peptide-1 (7-36) amide (GLP-1) is an insulin secretagogue and potential treatment for type II diabetes mellitus. An alternative to GLP-1 administration is endogenous dietary stimulation. We described a greater GLP-1 release following ingestion of liquids versus solids. We add to this work studying the effect of fluid preloads with differing glycaemic indices (GI) on the metabolic response to a meal.. GLP-1, insulin and glucose responses were measured in six overweight individuals and six subjects with type II diabetes on three occasions, after preload (milk, low GI; Ovaltine Light, high GI; or water, non-nutritive control) and meal ingestion.. In people with and without diabetes, the high GI preload produced the greatest glucose incremental area under the curve (IAUC)(0-20), followed by the low GI preload, and water (P<0.001). In both groups, insulin IAUC(0-20) was higher following high and low GI preloads compared with water (NS). In people without diabetes, the GLP-1 response was higher when high and low GI preloads were consumed compared with water (P=0.041), with no significant difference between nutritive preloads. GLP-1 response did not differ between preloads in people with diabetes. Despite initial differences, total IAUCs(0-200) for biochemical variables did not differ by preload.. We confirm that nutritive liquids stimulate GLP-1 to a greater extent than water in subjects without diabetes; however, this does not influence subsequent meal-induced response. The GI of preloads does not influence the degree of GLP-1 stimulation. Topics: Animals; Area Under Curve; Blood Chemical Analysis; Blood Glucose; Cross-Over Studies; Diabetes Mellitus, Type 2; Dietary Carbohydrates; Female; Gastric Emptying; Glucagon-Like Peptide 1; Glycemic Index; Humans; Insulin; Male; Middle Aged; Milk; Overweight; Postprandial Period; Water | 2007 |
Effects of dipeptidyl peptidase-4 inhibition on gastrointestinal function, meal appearance, and glucose metabolism in type 2 diabetes.
We sought to determine whether alterations in meal absorption and gastric emptying contribute to the mechanism by which inhibitors of dipeptidyl peptidase-4 (DPP-4) lower postprandial glucose concentrations.. We simultaneously measured gastric emptying, meal appearance, endogenous glucose production, and glucose disappearance in 14 subjects with type 2 diabetes treated with either vildaglipitin (50 mg b.i.d.) or placebo for 10 days using a double-blind, placebo-controlled, randomized, crossover design.. Fasting (7.3 +/- 0.5 vs. 7.9 +/- 0.5 mmol/l) and peak postprandial (14.1 +/- 0.6 vs. 15.9 +/- 0.9 mmol/l) glucose concentrations were lower (P < 0.01) after vildagliptin treatment than placebo. Despite lower glucose concentrations, postprandial insulin and C-peptide concentrations did not differ during the two treatments. On the other hand, the integrated (area under the curve) postprandial glucagon concentrations were lower (20.9 +/- 1.6 vs. 23.7 +/- 1.3 mg/ml per 5 h, P < 0.05), and glucagon-like peptide 1 (GLP-1) concentrations were higher (1,878 +/- 270 vs. 1,277 +/- 312 pmol/l per 5 h, P = 0.001) during vildagliptin administration compared with placebo. Gastric emptying and meal appearance did not differ between treatments.. Vildagliptin does not alter gastric emptying or the rate of entry of ingested glucose into the systemic circulation in humans. DPP-4 inhibitors do not lower postprandial glucose concentrations by altering the rate of nutrient absorption or delivery to systemic circulation. Alterations in islet function, secondary to increased circulating concentrations of active GLP-1, are associated with the decreased postprandial glycemic excursion observed in the presence of vildagliptin. Topics: Adenosine Deaminase Inhibitors; Appetite; Blood Glucose; Cross-Over Studies; Diabetes Mellitus, Type 2; Dipeptidyl Peptidase 4; Dipeptidyl-Peptidase IV Inhibitors; Double-Blind Method; Eating; Fasting; Gastric Emptying; Gastrointestinal Tract; Glucagon-Like Peptide 1; Glycoproteins; Humans; Postprandial Period | 2007 |
Liraglutide, a long-acting human glucagon-like peptide-1 analog, given as monotherapy significantly improves glycemic control and lowers body weight without risk of hypoglycemia in patients with type 2 diabetes.
Topics: Adult; Blood Glucose; Diabetes Mellitus, Type 2; Glucagon-Like Peptide 1; Glycated Hemoglobin; Humans; Hypoglycemia; Hypoglycemic Agents; Liraglutide; Placebos; Safety; Weight Loss | 2007 |
Pharmacodynamics of vildagliptin in patients with type 2 diabetes during OGTT.
This randomized, open-label, placebo-controlled, 7-period crossover study assessed dose-response relationships following single oral doses (10-400 mg) of vildagliptin in 16 patients with type 2 diabetes mellitus. Plasma levels of parent drug, dipeptidyl peptidase-4 activity, glucose, insulin, and glucagon were measured during 75-g oral glucose tolerance tests performed after an overnight fast, 30 minutes after drug administration. The t(max) for parent drug was observed between 0.5 and 1.5 hours postdose. Both C(max) and AUC(0-8 h) increased dose proportionately. Both onset and duration of dipeptidyl peptidase-4 inhibition were dose dependent, but >90% inhibition occurred within 45 minutes and was maintained for >/=4 hours after each dose. Glucose excursions and glucagon levels during oral glucose tolerance tests were significantly and similarly decreased after each dose of vildagliptin, and insulin levels were significantly and similarly increased after each dose level. Unlike findings during mixed-meal challenges, vildagliptin increases plasma insulin levels during oral glucose tolerance tests in patients with type 2 diabetes mellitus. Topics: Adamantane; Adenosine Deaminase; Adenosine Deaminase Inhibitors; Blood Glucose; Cross-Over Studies; Diabetes Mellitus, Type 2; Dipeptidyl Peptidase 4; Dipeptidyl-Peptidase IV Inhibitors; Female; Gastric Inhibitory Polypeptide; Glucagon; Glucagon-Like Peptide 1; Glucose Tolerance Test; Glycoproteins; Humans; Hypoglycemic Agents; Insulin; Male; Middle Aged; Nitriles; Pyrrolidines; Vildagliptin | 2007 |
Effects of the long-acting human glucagon-like peptide-1 analog liraglutide on beta-cell function in normal living conditions.
Topics: Aged; Blood Glucose; Diabetes Mellitus, Type 2; Double-Blind Method; Fasting; Female; Glucagon-Like Peptide 1; Humans; Insulin; Insulin Secretion; Insulin-Secreting Cells; Liraglutide; Male; Middle Aged; Placebos | 2007 |
Entero-endocrine changes after gastric bypass in diabetic and nondiabetic patients: a preliminary study.
Alterations in entero-endocrine signaling may play a role in improvements in satiety and glucose tolerance after Roux-en-Y gastric bypass (RYGB). We report our findings of gut hormone secretion in a cohort of diabetic and nondiabetic morbidly obese patients.. Ten morbidly obese subjects who underwent uncomplicated RYGB were studied: 5 were diabetic and 9 were female. Nonfasting plasma levels of glucagon-like peptide-1 (GLP-1), insulin, desacyl ghrelin, active ghrelin, neuropeptide Y (NPY), and gastric inhibitory polypeptide (GIP) were determined preoperatively and 6 months postoperatively.. Mean patient age was 42 +/- 11 years, and the mean preoperative body mass index was 50 +/- 6 kg/m(2). At 6 months mean BMI fell to 33 +/- 5 kg/m(2) (P < 0.0001), and there were no differences between diabetics and nondiabetics with respect to amount of weight loss. In non-diabetics, compared to preoperative levels, there were significant increases in GLP-1 and desacyl-ghrelin in the nondiabetic patients (P = 0.046 and P = 0.016, respectively); no change in plasma insulin, active ghrelin, NPY, or GIP was demonstrated. In contrast, when compared to preoperative levels, there were no significant changes in entero-endocrine hormone levels in the diabetic cohort postoperatively.. At 6 months postoperation, RYGB significantly alters the hormone levels for GLP-1 and desacyl-ghrelin in morbidly obese nondiabetic patients. No significant change was noted in a matched cohort of diabetic patients. Weight loss was similar in diabetics and nondiabetics, suggesting that GLP-1 and ghrelin are not the only mechanisms producing weight loss after RYGB. Topics: Adult; Diabetes Mellitus, Type 2; Female; Gastric Bypass; Gastric Inhibitory Polypeptide; Gastrointestinal Hormones; Gastrointestinal Tract; Ghrelin; Glucagon-Like Peptide 1; Humans; Insulin; Male; Middle Aged; Neuropeptide Y; Obesity, Morbid; Peptide Hormones; Weight Loss | 2007 |
Pharmacokinetics and pharmacodynamics of vildagliptin in patients with type 2 diabetes mellitus.
Vildagliptin is a dipeptidyl peptidase IV (DPP-4) inhibitor currently under development for the treatment of type 2 diabetes mellitus.. To assess the pharmacokinetic and pharmacodynamic characteristics and tolerability of vildagliptin at doses of 10 mg, 25 mg and 100 mg twice daily following oral administration in patients with type 2 diabetes.. Thirteen patients with type 2 diabetes were enrolled in this randomised, double-blind, double-dummy, placebo-controlled, four-period, crossover study. Patients received vildagliptin 10 mg, 25 mg and 100 mg as well as placebo twice daily for 28 days.. Vildagliptin was absorbed rapidly (median time to reach maximum concentration 1 hour) and had a mean terminal elimination half-life ranging from 1.32 to 2.43 hours. The peak concentration and total exposure increased in an approximately dose-proportional manner. Vildagliptin inhibited DPP-4 (>90%) at all doses and demonstrated a dose-dependent effect on the duration of inhibition. The areas under the plasma concentration-time curves of glucagon-like peptide-1 (GLP-1) [p < 0.001] and glucose-dependent insulinotropic peptide (GIP) [p < 0.001] were increased whereas postprandial glucagon was significantly reduced at the 25 mg (p = 0.006) and 100mg (p = 0.005) doses compared with placebo. As compared with placebo treatment, mean plasma glucose concentrations were decreased by 1.4 mmol/L with the vildagliptin 25 mg dosing regimen and by 2.5 mmol/L with the 100 mg dosing regimen, corresponding to a 10% and 19% reduction, respectively. Vildagliptin was generally well tolerated.. Vildagliptin is likely to be a useful therapy for patients with type 2 diabetes based on the inhibition of DPP-4 and the subsequent increase in incretin hormones, GLP-1 and GIP, and the decrease in glucose and glucagon levels. Topics: Adamantane; Administration, Oral; Adult; Aged; Area Under Curve; Blood Glucose; Cross-Over Studies; Diabetes Mellitus, Type 2; Dose-Response Relationship, Drug; Double-Blind Method; Drug Administration Schedule; Female; Gastric Inhibitory Polypeptide; Glucagon-Like Peptide 1; Half-Life; Humans; Hypoglycemic Agents; Male; Middle Aged; Nausea; Nitriles; Pyrrolidines; Treatment Outcome; Vildagliptin; Vomiting | 2007 |
A MUFA-rich diet improves posprandial glucose, lipid and GLP-1 responses in insulin-resistant subjects.
To study the effects of three weight-maintenance diets with different macronutrient composition on carbohydrate, lipid metabolism, insulin and incretin levels in insulin-resistant subjects.. A prospective study was performed in eleven (7 W, 4 M) offspring of obese and type 2 diabetes patients. Subjects had a BMI > 25 Kg/m2, waist circumference (men/women) > 102/88, HBA1c < 6.5% and were regarded as insulin-resistant after an OGTT (Matsuda ISIm <4). They were randomly divided into three groups and underwent three dietary periods each of 28 days in a crossover design: a) diet high in saturated fat (SAT), b) diet rich in monounsaturated fat (MUFA; Mediterranean diet) and c) diet rich in carbohydrate (CHO).. Body weight and resting energy expenditure did not changed during the three dietary periods. Fasting serum glucose concentrations fell during MUFA-rich and CHO-rich diets compared with high-SAT diets (5.02 +/- 0.1, 5.03 +/- 0.1, 5.50 +/- 0.2 mmol/L, respectively. Anova < 0.05). The MUFA-rich diet improved insulin sensitivity, as indicated by lower homeostasis model analysis-insulin resistance (HOMA-ir), compared with CHO-rich and high-SAT diets (2.32 +/- 0.3, 2.52 +/- 0.4, 2.72 +/- 0.4, respectively, Anova < 0.01). After a MUFA-rich and high-SAT breakfasts (443 kcal) the postprandial integrated area under curve (AUC) of glucose and insulin were lowered compared with isocaloric CHO-rich breakfast (7.8 +/- 1.3, 5.84 +/- 1.2, 11.9 +/- 2.7 mmol . 180 min/L, Anova < 0.05; and 1004 +/- 147, 1253 +/- 140, 2667 +/- 329 pmol . 180 min/L, Anova <0.01, respectively); while the integrated glucagon-like peptide-1 response increased with MUFA and SAT breakfasts compared with isocaloric CHO-rich meals (4.22 +/- 0.7, 4.34 +/- 1.1, 1.85 +/- 1.1, respectively, Anova < 0.05). Fasting and postprandial HDL cholesterol concentrations rose with MUFA-rich diets, and the AUCs of triacylglycerol fell with the CHO-rich diet. Similarly fasting proinsulin (PI) concentration fell, while stimulated ratio PI/I was not changed by MUFA-rich diet.. Weight maintenance with a MUFA-rich diet improves HOMA-ir and fasting proinsulin levels in insulin-resistant subjects. Ingestion of a virgin olive oil-based breakfast decreased postprandial glucose and insulin concentrations, and increased HDL-C and GLP-1 concentrations as compared with CHO-rich diet. Topics: Analysis of Variance; Area Under Curve; Blood Glucose; Calorimetry, Indirect; Cross-Over Studies; Diabetes Mellitus, Type 2; Dietary Carbohydrates; Dietary Fats; Dietary Fats, Unsaturated; Fatty Acids; Female; Glucagon-Like Peptide 1; Glucose Tolerance Test; Humans; Incretins; Insulin; Insulin Resistance; Lipids; Male; Middle Aged; Obesity; Postprandial Period; Prospective Studies | 2007 |
The metabolite generated by dipeptidyl-peptidase 4 metabolism of glucagon-like peptide-1 has no influence on plasma glucose levels in patients with type 2 diabetes.
Glucagon-like peptide-1 (GLP-1) is metabolised by the enzyme dipeptidyl-peptidase 4 (DPP-4), generating a metabolite with potential antagonistic properties. This study was conducted to evaluate the effect of that metabolite on plasma glucose levels in patients with type 2 diabetes.. The randomised crossover study consisted of five regimens: (1) i.v. infusion of GLP-1 (1.2 pmol kg(-1) min(-1); IV); (2 and 3) s.c. infusion of GLP-1 (2.4 and 9.6 pmol kg(-1) min(-1); LSC, HSC); (4) s.c. infusion of GLP-1 (2.4 pmol kg(-1) min(-1)) in combination with a DPP-4 inhibitor (IB); and (5) s.c. infusion of saline (154 mmol NaCl/l; SAL). Seven patients with type 2 diabetes participated in all protocols.. Plasma levels of intact GLP-1 increased from 7+/-1 (SAL) to 17+/-3 (LSC), 61+/-7 (IB), 62+/-5 (IV) and 94+/-10 (9.6 s.c.) pmol/l, p<0.0001. Plasma concentrations of the metabolite increased from 1+/-3 (SAL) and 2+/-6 (IB) pmol/l to 42+/-4 (LSC), 64+/-8 (IV) and 327+/-16 (HSC) pmol/l, p<0.0001. Mean plasma glucose levels at 6 h decreased from 12.4+/-1.1 (SAL) mmol/l to 10.4+/-1.1 (LSC), 8.6+/-0.6 (IB), 8.8+/-0.8 (IV) and 9.1+/-0.9 (HSC) mmol/l, p<0.0001.. At approximately similar concentrations of intact GLP-1 (IV, IB, HSC), but with widely ranging metabolite concentrations, the effect on plasma glucose levels was equal, indicating that the presence of the metabolite does not antagonise the glucose-lowering effect of GLP-1. Topics: Blood Glucose; C-Peptide; Cross-Over Studies; Diabetes Mellitus, Type 2; Dipeptidyl Peptidase 4; Enzyme Activation; Enzyme Inhibitors; Female; Glucagon; Glucagon-Like Peptide 1; Humans; Insulin; Male; Middle Aged; Nitriles; Peptides; Pyrrolidines | 2006 |
Pharmacokinetic and pharmacodynamic properties of multiple oral doses of sitagliptin, a dipeptidyl peptidase-IV inhibitor: a double-blind, randomized, placebo-controlled study in healthy male volunteers.
Dipeptidyl peptidase-IV (DPP-IV) inhibitors represent a new class of oral antihyperglycemic agents. Sitagliptin is an orally active and selective DPP-IV inhibitor currently in Phase III development for the treatment of type 2 diabetes mellitus.. The aim of this study was to assess the pharmacokinetic and pharmacodynamic (PK/PD) properties and tolerability of multiple oral once-daily or twice-daily doses of sitagliptin.. This double-blind, randomized, placebo-controlled,incremental oral-dose study was conducted at SGS Biopharma, Antwerp, Belgium. Healthy, nonsmoking male volunteers aged 18 to 45 years with a creatinine clearance rate of >80 mL/min and normoglycemia and weighing within 15% of their ideal height/weight range were randomly assigned to 1 of 8 treatment groups: sitagliptin 25, 50, 100, 200, or 400 mg or placebo, QD for 10 days; a single dose of sitagliptin 800 mg administered on day 1 followed by 600 mg QD on days 3 to 10; or sitagliptin 300 mg BID for 10 days. For analysis of PK properties, plasma and urine samples were obtained before study drug administration on day 1 and at 0.5, 1, 2, 4, 6, 8, 10, 12, and 16 hours after study drug administration on day 1; before study drug administration on days 2 to 9; and every 24 hours for 96 hours after the last dose on day 10, and analyzed for sitagliptin concentrations. Assays were used to measure inhibition of plasma DPP-IV activity and plasma concentrations of active and total glucagon-like peptide-1 (GLP-1), glucose, and glucagon, and serum concentrations of insulin, C-peptide, insulin-like growth factor-1, and insulin like growth factor binding protein-3. Tolerability was assessed throughout the study using physical examination, including vital sign measurements; 12-lead electrocardiography; and laboratory analysis, including hematology, biochemistry (hepatic aminotransferase and creatine phosphokinase), and urinalysis.. Seventy subjects were enrolled (mean age, 32.9 years [range, 18-45 years]; mean weight, 79.7 kg [range, 63.4-97.7 kg]; 8 patients per sitagliptin study group and 14 patients in the control group). In the sitagliptin groups, the plasma concentration-time profiles and principal PK parameters (T(max), C(max), and t((1/2))) were statistically similar at days 1 (single dose) and 10 (steady state). In the groups receiving sitagliptin QD doses, accumulation of sitagliptin was modest (AUC accumulation ratio [day 10/day 1] range, 1.05-1.29), and the apparent terminal elimination t((1/2)) was 11.8 to 14.4 hours. At steady state in the sitagliptin QD groups, the mean proportion of drug excreted unchanged in the urine was approximately 70.6%. Dose-dependent inhibition of plasma DPP-IV activity was apparent, and the pattern of inhibition at steady state (day 10) was statistically similar to that observed on day 1. Day-10 weighted mean inhibition of plasma DPP-IV activity over 24 hours was > or = 80% for doses of > or = 50 mg QD. After a standard meal, active GLP-1 concentrations were significantly increased in the sitagliptin groups by approximately 2-fold compared with that in the control group, a finding consistent with near-maximal acute glucose lowering in preclinical studies. Across doses, no apparent adverse effects, including hypoglycemia, were found or reported.. The results from this study in a select population of healthy male volunteers suggest that multiple oral doses of sitagliptin inhibited plasma DPP-IV activity and affected active GLP-1 concentrations in a dose-dependent manner, without producing hypoglycemia. Multiple dosing of sitagliptin exhibited a PK/PD profile consistent with that of a QD regimen and was well tolerated. Topics: Administration, Oral; Adolescent; Adult; Blood Glucose; Diabetes Mellitus, Type 2; Dipeptidyl Peptidase 4; Dose-Response Relationship, Drug; Double-Blind Method; Enzyme-Linked Immunosorbent Assay; Follow-Up Studies; Glucagon-Like Peptide 1; Humans; Insulin-Like Growth Factor Binding Protein 3; Insulin-Like Growth Factor I; Male; Middle Aged; Pyrazines; Reference Values; Sitagliptin Phosphate; Triazoles | 2006 |
Vildagliptin therapy reduces postprandial intestinal triglyceride-rich lipoprotein particles in patients with type 2 diabetes.
We assessed the effects of vildagliptin, a novel dipeptidyl peptidase IV inhibitor, on postprandial lipid and lipoprotein metabolism in patients with type 2 diabetes.. This was a single-centre, randomised, double-blind study in drug-naive patients with type 2 diabetes. Patients received vildagliptin (50 mg twice daily, n=15) or placebo (n=16) for 4 weeks. Triglyceride, cholesterol, lipoprotein, glucose, insulin, glucagon and glucagon-like peptide-1 (GLP-1) responses to a fat-rich mixed meal were determined for 8 h postprandially before and after 4 weeks of treatment.. Relative to placebo, 4 weeks of treatment with vildagliptin decreased the AUC(0-8h) for total trigyceride by 22+/-11% (p=0.037), the incremental AUC(0-8h) (IAUC(0-8h)) for total triglyceride by 85+/-47% (p=0.065), the AUC(0-8h) for chylomicron triglyceride by 65+/-19% (p=0.001) and the IAUC(0-8h) for chylomicron triglyceride by 91+/-28% (p=0.002). This was associated with a decrease in chylomicron apolipoprotein B-48 (AUC(0-8h), -1.0+/-0.5 mg l(-1) h, p=0.037) and chylomicron cholesterol (AUC(0-8h), -0.14+/-0.07 mmol l(-1) h, p=0.046). Consistent with previous studies, 4 weeks of treatment with vildagliptin also increased intact GLP-1, suppressed inappropriate glucagon secretion, decreased fasting and postprandial glucose, and decreased HbA(1c) from a baseline of 6.7% (change, -0.4+/-0.1%, p<0.001), all relative to placebo.. Treatment with vildagliptin for 4 weeks improves postprandial plasma triglyceride and apolipoprotein B-48-containing triglyceride-rich lipoprotein particle metabolism after a fat-rich meal. The mechanisms underlying the effects of this dipeptidyl peptidase IV inhibitor on postprandial lipid metabolism remain to be explored. Topics: Adamantane; Apolipoprotein B-48; Blood Glucose; Diabetes Mellitus, Type 2; Dipeptidyl-Peptidase IV Inhibitors; Double-Blind Method; Female; Glucagon; Glucagon-Like Peptide 1; Humans; Insulin; Intestinal Mucosa; Intestines; Lipids; Lipoproteins; Male; Middle Aged; Nitriles; Postprandial Period; Pyrrolidines; Time Factors; Treatment Outcome; Triglycerides; Vildagliptin | 2006 |
Effect of single oral doses of sitagliptin, a dipeptidyl peptidase-4 inhibitor, on incretin and plasma glucose levels after an oral glucose tolerance test in patients with type 2 diabetes.
In response to a meal, glucagon-like peptide-1 (GLP-1) and glucose-dependent insulinotropic peptide (GIP) are released and modulate glycemic control. Normally these incretins are rapidly degraded by dipeptidyl peptidase-4 (DPP-4). DPP-4 inhibitors are a novel class of oral antihyperglycemic agents in development for the treatment of type 2 diabetes. The degree of DPP-4 inhibition and the level of active incretin augmentation required for glucose lowering efficacy after an oral glucose tolerance test (OGTT) were evaluated.. The objective of the study was to examine the pharmacodynamics, pharmacokinetics, and tolerability of sitagliptin.. This was a randomized, double-blind, placebo-controlled, three-period, single-dose crossover study.. The study was conducted at six investigational sites.. The study population consisted of 58 patients with type 2 diabetes who were not on antihyperglycemic agents.. Interventions included sitagliptin 25 mg, sitagliptin 200 mg, or placebo.. Measurements included plasma DPP-4 activity; post-OGTT glucose excursion; active and total incretin GIP levels; insulin, C-peptide, and glucagon concentrations; and sitagliptin pharmacokinetics.. Sitagliptin dose-dependently inhibited plasma DPP-4 activity over 24 h, enhanced active GLP-1 and GIP levels, increased insulin/C-peptide, decreased glucagon, and reduced glycemic excursion after OGTTs administered at 2 and 24 h after single oral 25- or 200-mg doses of sitagliptin. Sitagliptin was generally well tolerated, with no hypoglycemic events.. In this study in patients with type 2 diabetes, near maximal glucose-lowering efficacy of sitagliptin after single oral doses was associated with inhibition of plasma DPP-4 activity of 80% or greater, corresponding to a plasma sitagliptin concentration of 100 nm or greater, and an augmentation of active GLP-1 and GIP levels of 2-fold or higher after an OGTT. Topics: Administration, Oral; Adult; Area Under Curve; Blood Glucose; Cross-Over Studies; Diabetes Mellitus, Type 2; Dipeptidyl-Peptidase IV Inhibitors; Double-Blind Method; Enzyme Inhibitors; Female; Gastric Inhibitory Polypeptide; Glucagon-Like Peptide 1; Glucose Tolerance Test; Humans; Hypoglycemic Agents; Male; Middle Aged; Placebos; Pyrazines; Sitagliptin Phosphate; Triazoles | 2006 |
Tolerability and pharmacokinetics of metformin and the dipeptidyl peptidase-4 inhibitor sitagliptin when co-administered in patients with type 2 diabetes.
As part of the clinical development of sitagliptin, a dipeptidyl peptidase-4 inhibitor, for the treatment of type 2 diabetes, the potential for pharmacokinetic interactions with other antihyperglycemic agents used in managing patients with type 2 diabetes are being carefully evaluated. The purposes of this study were to evaluate the tolerability of co-administered sitagliptin and metformin and effects of sitagliptin on metformin pharmacokinetics as well as metformin on sitagliptin pharmacokinetics under steady-state conditions.. This placebo-controlled, multiple-dose, crossover study in patients with type 2 diabetes assessed the tolerability of co-administered sitagliptin (50 mg b.i.d.) with metformin (1000 mg b.i.d.). Patients received, in a randomized crossover manner, three treatments (each of 7 days duration): 50 mg sitagliptin twice daily and placebo to metformin twice daily; 1000 mg of metformin twice daily and placebo to sitagliptin twice daily; concomitant administration of 50 mg of sitagliptin twice daily and 1000 mg of metformin twice daily. Following dosing on Day 7 of each treatment period, these pharmacokinetic parameters were determined for plasma sitagliptin and metformin: area under the plasma concentrations-time curve over the dosing interval (AUC(0-12h)), maximum observed plasma concentrations (C(max)), and time of occurrence of maximum observed plasma concentrations (T(max)). Renal clearance was also determined for sitagliptin.. In this study, no adverse experiences were reported by 11 of 13 patients. Two patients had adverse experiences, which were not related to study drugs as determined by the investigators. The mean metformin plasma concentration-time profiles were nearly identical with or without sitagliptin co-administration [metformin AUC(0-12h) geometric mean ratio (GMR; [metformin + sitagliptin]/metformin)] was 1.02 (90% CI 0.95, 1.09). Similarly metformin administration did not alter the plasma sitagliptin pharmacokinetics [sitagliptin AUC(0-12 h) GMR ([sitagliptin + metformin]/sitagliptin)] was 1.02 (90% CI 0.97, 1.08) or renal clearance of sitagliptin. No efficacy measurements (glycosylated hemoglobin or fasting plasma glucose) were obtained during this study. Urinary pharmacokinetics for metformin were not determined due to the lack of effect of sitagliptin on plasma metformin pharmacokinetics.. In this study, co-administration of sitagliptin and metformin was generally well tolerated in patients with type 2 diabetes and did not meaningfully alter the steady-state pharmacokinetics of either agent. Topics: Adenosine Deaminase Inhibitors; Adult; Area Under Curve; Cross-Over Studies; Diabetes Mellitus, Type 2; Dipeptidyl Peptidase 4; Double-Blind Method; Drug Synergism; Drug Therapy, Combination; Female; Glucagon-Like Peptide 1; Glycoproteins; Humans; Hypoglycemic Agents; Male; Metformin; Middle Aged; Pyrazines; Sitagliptin Phosphate; Triazoles | 2006 |
Five weeks of treatment with the GLP-1 analogue liraglutide improves glycaemic control and lowers body weight in subjects with type 2 diabetes.
Effects of the long acting GLP-1 analogue--liraglutide in subjects with type 2 diabetes.. 144 type 2 diabetic subjects on metformin treatment (1000 mg BID) were randomised to 5 weeks of treatment (double-blind) with metformin plus liraglutide, liraglutide or metformin, or metformin plus glimepiride (open label). The dose of liraglutide was increased weekly from 0.5 to 2 mg OD.. Liraglutide added to metformin monotherapy was associated with a significant reduction in fasting serum glucose (FSG) (-3.9 mM -4.9; -2.9) (primary objective), and HbA1c levels (-0.8% -1.2; -0.4). Furthermore, liraglutide in combination with metformin vs. metformin plus glimepiride significantly reduced FSG (-1.2 mM -2.2; -0.2). In addition, body weight was significantly lower in the metformin plus liraglutide vs. the metformin plus glimepiride group (-2.9 kg -3.6; -2.1). There were no biochemically confirmed episodes of hypoglycaemia with liraglutide treatment. Nausea was the most frequently reported adverse event following liraglutide therapy, it was transient in nature, and led to withdrawal of only 4% of the subjects.. Using a weekly dose-titration liraglutide is well tolerated up to 2 mg daily. While liraglutide caused transient gastrointestinal side effects, this rarely interfered with continuing treatment. An improvement in FSG over that in control groups was seen for liraglutide as an add-on to metformin. In the latter case, body weight was reduced in comparison to metformin plus glimepiride. Liraglutide is a promising drug for the treatment of type 2 diabetes. Topics: Adult; Blood Glucose; Body Weight; Diabetes Mellitus, Type 2; Double-Blind Method; Drug Therapy, Combination; Female; Glucagon-Like Peptide 1; Humans; Hypoglycemic Agents; Liraglutide; Male; Metformin; Middle Aged | 2006 |
alpha-Glucosidase inhibition (acarbose) fails to enhance secretion of glucagon-like peptide 1 (7-36 amide) and to delay gastric emptying in Type 2 diabetic patients.
Acarbose is able to enhance GLP-1 release and delay gastric emptying in normal subjects. The effect of alpha-glucosidase inhibition on GLP-1 has been less evident in Type 2 diabetic patients. The aim of this study was to investigate the possible influence of acarbose on GLP-1 release and gastric emptying in Type 2 diabetic patients after a mixed test meal.. Ten Type 2 diabetic patients were tested with 100 mg acarbose or placebo served with a mixed meal that was labelled with 100 mg 13C-octanoic acid. Plasma concentrations of glucose, insulin, C-peptide, glucagon, GLP-1 and GIP were determined over 6 h. Gastric emptying was measured by determining breath 13CO2 using infrared absorptiometry. Statistics repeated-measures anova.. Gastric emptying rates (t1/2: 162 +/- 45 vs. 163 +/- 62 min, P = 0.65) and plasma concentrations (increasing from approximately 12 to approximately 25 pmol/l, P = 0.37) and integrated responses of GLP-1 (P = 0.37) were not changed significantly by acarbose treatment. Postprandial plasma glucose concentrations (P < 0.0001) and their integrated responses were lowered by acarbose (by 64%; P = 0.016). The plasma concentrations of insulin and C-peptide were reduced (P = 0.007 and 0.057, respectively) by acarbose, while glucagon was not changed (P = 0.96). GIP plasma concentrations (increasing with placebo from approximately 10 to approximately 85 pmol/l and with acarbose to approximately 55 pmol/l (P < 0.0001) and their integrated responses were significantly lowered (by 43%) by acarbose (P = 0.021). After 2 weeks of acarbose treatment (50 mg t.i.d. for the first and 100 mg t.i.d. for the second week, n = 6), similar results were found.. In hyperglycaemic Type 2 diabetic patients, ingestion of acarbose with a mixed test meal failed to enhance GLP-1 release and did not influence gastric emptying. Topics: Acarbose; Blood Glucose; C-Peptide; Diabetes Mellitus, Type 2; Enzyme Inhibitors; Female; Gastric Emptying; Gastric Inhibitory Polypeptide; Glucagon; Glucagon-Like Peptide 1; Glycoside Hydrolase Inhibitors; Humans; Hypoglycemic Agents; Insulin; Male; Middle Aged; Peptide Fragments; Postprandial Period; Protein Precursors | 2005 |
Initially more rapid small intestinal glucose delivery increases plasma insulin, GIP, and GLP-1 but does not improve overall glycemia in healthy subjects.
The rate of gastric emptying of glucose-containing liquids is a major determinant of postprandial glycemia. The latter is also dependent on stimulation of insulin secretion by glucose-dependent insulinotropic polypeptide (GIP) and glucagon-like peptide-1 (GLP-1). Although overall emptying of glucose approximates 1-3 kcal/min, the "early phase" of gastric emptying is usually more rapid. We have evaluated the hypothesis that increased stimulation of incretin hormones and insulin by a more rapid initial rate of small intestinal glucose delivery would reduce the overall glycemic response to a standardized enteral glucose load. Twelve healthy subjects were studied on two separate days in which they received an intraduodenal (id) glucose infusion for 120 min. On one day, the infusion rate was variable, being more rapid (6 kcal/min) between t = 0 and 10 min and slower (0.55 kcal/min) between t = 10 and 120 min, whereas on the other day the rate was constant (1 kcal/min) from t = 0-120 min, i.e., on both days 120 kcal were given. Between t = 0 and 75 min, plasma insulin, GIP, and GLP-1 were higher with the variable infusion. Despite the increase in insulin and incretin hormones, blood glucose levels were also higher. Between t = 75 and 180 min, blood glucose and plasma insulin were lower with the variable infusion. There was no difference in the area under the curve 0-180 min for blood glucose. We conclude that stimulation of incretin hormone and insulin release by a more rapid initial rate of id glucose delivery does not lead to an overall reduction in glycemia in healthy subjects. Topics: Adult; Blood Glucose; Diabetes Mellitus, Type 2; Gastric Emptying; Gastric Inhibitory Polypeptide; Glucagon; Glucagon-Like Peptide 1; Glucose; Humans; Hyperglycemia; Insulin; Intestine, Small; Male; Peptide Fragments; Postprandial Period; Protein Precursors; Reference Values | 2005 |
Effect of whey on blood glucose and insulin responses to composite breakfast and lunch meals in type 2 diabetic subjects.
Whey proteins have insulinotropic effects and reduce the postprandial glycemia in healthy subjects. The mechanism is not known, but insulinogenic amino acids and the incretin hormones seem to be involved.. The aim was to evaluate whether supplementation of meals with a high glycemic index (GI) with whey proteins may increase insulin secretion and improve blood glucose control in type 2 diabetic subjects.. Fourteen diet-treated subjects with type 2 diabetes were served a high-GI breakfast (white bread) and subsequent high-GI lunch (mashed potatoes with meatballs). The breakfast and lunch meals were supplemented with whey on one day; whey was exchanged for lean ham and lactose on another day. Venous blood samples were drawn before and during 4 h after breakfast and 3 h after lunch for the measurement of blood glucose, serum insulin, glucose-dependent insulinotropic polypeptide (GIP), and glucagon-like peptide 1 (GLP-1).. The insulin responses were higher after both breakfast (31%) and lunch (57%) when whey was included in the meal than when whey was not included. After lunch, the blood glucose response was significantly reduced [-21%; 120 min area under the curve (AUC)] after whey ingestion. Postprandial GIP responses were higher after whey ingestion, whereas no differences were found in GLP-1 between the reference and test meals.. It can be concluded that the addition of whey to meals with rapidly digested and absorbed carbohydrates stimulates insulin release and reduces postprandial blood glucose excursion after a lunch meal consisting of mashed potatoes and meatballs in type 2 diabetic subjects. Topics: Adult; Aged; Area Under Curve; Blood Glucose; Diabetes Mellitus, Type 2; Dietary Proteins; Female; Gastric Inhibitory Polypeptide; Glucagon; Glucagon-Like Peptide 1; Glycemic Index; Humans; Insulin; Insulin Secretion; Male; Middle Aged; Milk Proteins; Peptide Fragments; Postprandial Period; Protein Precursors; Whey Proteins | 2005 |
Effects of liraglutide (NN2211), a long-acting GLP-1 analogue, on glycaemic control and bodyweight in subjects with Type 2 diabetes.
Liraglutide (NN2211) is a long-acting GLP-1 analogue, with a pharmacokinetic profile suitable for once-daily administration. This multicentre, double-blind, parallel-group, double-dummy study explored the dose-response relationship of liraglutide effects on bodyweight and glycaemic control in subjects with Type 2 diabetes.. Subjects (BMI 27-42 kg/m(2)) with Type 2 diabetes who were previously treated with an OAD (oral anti-diabetic drug) monotherapy (69% with metformin), and had HbA(1c) < or = 10% were enrolled. After a 4-week metformin run-in period, 210 subjects (27-73 years, 60% female) were randomised to receive liraglutide (0.045-0.75 mg) once daily or continued on metformin 1000 mg b.d. for 12 weeks.. Mean baseline values for the six treatment groups ranged from 6.8 to 7.5% for HbA(1c), and 8.06-9.44 mmol/l (145-170 mg/dl) for fasting plasma glucose. After 12-week treatment, a weight change of -0.05 to -1.9% was observed for the six treatment groups. Mean HbA(1c) changes from baseline for 0.045, 0.225, 0.45, 0.6, 0.75 mg liraglutide and metformin were +1.28%, +0.86%, +0.22%, +0.16%, +0.30% and +0.09%, respectively. No significant differences in HbA(1c) were observed between liraglutide and metformin groups at the three highest liraglutide dose levels (0.45, 0.6 and 0.75 mg). The lowest two liraglutide doses (0.045 mg and 0.225 mg) were not sufficient to maintain the fasting plasma glucose values achieved by metformin. No major hypoglycaemic episodes were reported. Episodes of nausea and/or vomiting were reported by 11 patients (6.3%) receiving liraglutide and three (8.8%) receiving metformin.. Once-daily liraglutide improved glycaemic control and weight, in a comparable degree to metformin. Liraglutide appeared to be safe and generally well tolerated. Higher doses of liraglutide merit study in future clinical trials. Topics: Adult; Aged; Blood Glucose; Body Mass Index; Body Weight; Delayed-Action Preparations; Diabetes Mellitus, Type 2; Double-Blind Method; Drug Administration Schedule; Female; Glucagon; Glucagon-Like Peptide 1; Glycated Hemoglobin; Humans; Hypoglycemic Agents; Liraglutide; Male; Middle Aged | 2005 |
Exenatide augments first- and second-phase insulin secretion in response to intravenous glucose in subjects with type 2 diabetes.
First-phase insulin secretion (within 10 min after a sudden rise in plasma glucose) is reduced in type 2 diabetes mellitus (DM2). The incretin mimetic exenatide has glucoregulatory activities in DM2, including glucose-dependent enhancement of insulin secretion.. The objective of the study was to determine whether exenatide can restore a more normal pattern of insulin secretion in subjects with DM2.. Fasted subjects received iv insulin infusion to reach plasma glucose 4.4-5.6 mmol/liter. Subjects received iv exenatide (DM2) or saline (DM2 and healthy volunteers), followed by iv glucose challenge.. Thirteen evaluable DM2 subjects were included in the study: 11 males, two females; age, 56 +/- 7 yr; body mass index, 31.7 +/- 2.4 kg/m2; hemoglobin A1c, 6.6 +/- 0.7% (mean +/- sd) treated with diet/exercise (n = 1), metformin (n = 10), or acarbose (n = 2). Controls included 12 healthy, weight-matched subjects with normal glucose tolerance: nine males, three females; age, 57 +/- 9 yr; and body mass index, 32.0 +/- 3.0 kg/m2.. The study was conducted at an academic hospital.. Plasma insulin, plasma C-peptide, insulin secretion rate (derived by deconvolution), and plasma glucagon were the main outcome measures.. DM2 subjects administered saline had diminished first-phase insulin secretion, compared with healthy control subjects. Exenatide-treated DM2 subjects had an insulin secretory pattern similar to healthy subjects in both first (0-10 min) and second (10-180 min) phases after glucose challenge, in contrast to saline-treated DM2 subjects. In exenatide-treated DM2 subjects, the most common adverse event was moderate nausea (two of 13 subjects).. Short-term exposure to exenatide can restore the insulin secretory pattern in response to acute rises in glucose concentrations in DM2 patients who, in the absence of exenatide, do not display a first phase of insulin secretion. Loss of first-phase insulin secretion in DM2 patients may be restored by treatment with exenatide. Topics: Adult; Diabetes Mellitus, Type 2; Exenatide; Female; Glucagon-Like Peptide 1; Glucose; Humans; Insulin; Insulin Secretion; Male; Middle Aged; Peptides; Venoms | 2005 |
Antihyperglycemic effects of stevioside in type 2 diabetic subjects.
Stevioside is present in the plant Stevia rebaudiana Bertoni (SrB). Extracts of SrB have been used for the treatment of diabetes in, for example, Brazil, although a positive effect on glucose metabolism has not been unequivocally demonstrated. We studied the acute effects of stevioside in type 2 diabetic patients. We hypothesize that supplementation with stevioside to a test meal causes a reduction in postprandial blood glucose. Twelve type 2 diabetic patients were included in an acute, paired cross-over study. A standard test meal was supplemented with either 1 g of stevioside or 1 g of maize starch (control). Blood samples were drawn at 30 minutes before and for 240 minutes after ingestion of the test meal. Compared to control, stevioside reduced the incremental area under the glucose response curve by 18% (P =.013). The insulinogenic index (AUC(i,insulin)/AUC(i,glucose)) was increased by approximately 40% by stevioside compared to control (P <.001). Stevioside tended to decrease glucagon levels, while it did not significantly alter the area under the insulin, glucagon-like peptide 1, and glucose-dependent insulinotropic polypeptide curves. In conclusion, stevioside reduces postprandial blood glucose levels in type 2 diabetic patients, indicating beneficial effects on the glucose metabolism. Stevioside may be advantageous in the treatment of type 2 diabetes. Topics: Aged; Blood Glucose; Cross-Over Studies; Diabetes Mellitus, Type 2; Diterpenes; Diterpenes, Kaurane; Diuresis; Fatty Acids, Nonesterified; Female; Food; Gastric Inhibitory Polypeptide; Glucagon; Glucagon-Like Peptide 1; Glucosides; Glycated Hemoglobin; Glycosuria; Humans; Hypoglycemic Agents; Insulin; Kinetics; Male; Middle Aged; Peptide Fragments; Placebos; Protein Precursors; Triglycerides | 2004 |
Ethanol with a mixed meal decreases the incretin levels early postprandially and increases postprandial lipemia in type 2 diabetic patients.
Increased postprandial lipemia is a risk marker of cardiovascular disease (CVD). While moderate alcohol drinking is associated with a reduced risk of CVD in nondiabetic and type 2 diabetic patients, it is also known that alcohol increases postprandial triacylglycerol levels. The incretins, glucose-dependent insulinotropic polypeptide (GIP) and glucagon-like peptide 1 (GLP-1), are important hormones from the gut that enhance nutrient-stimulated insulin secretion. Their responses to a moderate alcohol dose in type 2 diabetes have not previously been studied. We sought to determine how alcohol influences postprandial lipid and incretin levels in patients with type 2 diabetes when taken in combination with a fat-rich mixed meal. Eleven patients with type 2 diabetes ingested on 3 separate days in random order 3 different meals containing: 100 g butter alone or 100 g butter in combination with 40 g alcohol and 50 g carbohydrate, or 100 g butter and 120 g carbohydrate. The meal with alcohol and 50 g carbohydrate was isocaloric to that of 120 g carbohydrate. Triacylglycerol levels were measured after separation by ultracentrifugation into a chylomicron-rich fraction with Svedberg flotation unit values (Sf) > 1,000, and a chylomicron-poor fraction with Sf < 1,000. Supplementation of a fat-rich mixed meal with alcohol in type 2 diabetic subjects suppressed GLP-1 early in the postprandial phase and increased the late triacylglycerol responses compared with the 2 other meals. In the chylomicron-rich fraction, both triacylglycerol and cholesterol were increased by alcohol. No significant differences in high-density lipoprotein (HDL)-cholesterol levels were seen. Isocaloric amounts of carbohydrate and alcohol suppressed equally the postprandial free fatty acid levels, but carbohydrate increased the postprandial glucose, GIP, and insulin levels the most. Early in the postprandial phase, alcohol suppresses the incretin responses and increases the late postprandial triacylglycerol levels in type 2 diabetic patients. Whether this reflects an alcohol-induced suppression of the incretin response, which adds to the alcohol-induced impairment of triacylglycerol clearance in type 2 diabetic patients, remains to be elucidated. Topics: Aged; Alcohol Drinking; Butter; Cholesterol; Cholesterol, HDL; Chylomicrons; Diabetes Mellitus, Type 2; Dietary Carbohydrates; Dietary Fats; Energy Intake; Ethanol; Fatty Acids; Fatty Acids, Nonesterified; Food; Gastric Inhibitory Polypeptide; Glucagon; Glucagon-Like Peptide 1; Glucagon-Like Peptides; Humans; Insulin; Lipids; Middle Aged; Peptide Fragments; Protein Precursors; Triglycerides | 2004 |
Blood glucose control in healthy subject and patients receiving intravenous glucose infusion or total parenteral nutrition using glucagon-like peptide 1.
It was the aim of the study to examine whether the insulinotropic gut hormone GLP-1 is able to control or even normalise glycaemia in healthy subjects receiving intravenous glucose infusions and in severely ill patients hyperglycaemic during total parenteral nutrition.. Eight healthy subjects and nine patients were examined. The volunteers received, in six separate experiments in randomised order, intravenous glucose at doses of 0, 2 and 5mg kg(-1) min(-1), each with intravenous GLP-1 or placebo for 6 h. Patients were selected on the basis of hyperglycaemia (>150 mg/dl) during complete parenteral nutrition with glucose (3.2+/-1.4 mg kg(-1) min(-1)), amino acids (n=8; 0.9+/-0.2 mg kg(-1) min(-1)), with or without lipid emulsions. Four hours (8 a.m. to 12 a.m. on parenteral nutrition plus NaCl as placebo) were compared to 4 h (12 a.m. to 4 p.m.) with additional GLP-1 administered intravenously. The dose of GLP-1 was 1.2 pmol kg(-1) min(-1). Blood was drawn for the determination of glucose, insulin, C-peptide, GLP-1, glucagon, and free fatty acids.. Glycaemia was raised dose-dependently by glucose infusions in healthy volunteers (p<0.0001). GLP-1 ( approximately 100-150 pmol/l) stimulated insulin and reduced glucagon secretion and reduced glucose concentrations into the normoglycaemic fasting range (all p<0.05). In hyperglycaemic patients, glucose concentrations during the placebo period averaged 211+/-24 mg/dl. This level was reduced to 159+/-25 mg/dl with GLP-1 (p<0.0001), accompanied by a rise in insulin (p=0.0002) and C-peptide (p<0.0001), and by trend towards a reduction in glucagon (p=0.08) and free fatty acids (p=0.02). GLP-1 was well tolerated.. Hyperglycaemia during parenteral nutrition can be controlled by exogenous GLP-1, e.g. the natural peptide (available today), whereas the chronic therapy of Type 2 diabetes requires GLP-1 derivatives with longer duration of action. Topics: Adult; Blood Glucose; Diabetes Mellitus, Type 2; Dose-Response Relationship, Drug; Fatty Acids; Female; Glucagon; Glucagon-Like Peptide 1; Glucagon-Like Peptides; Glucose; Humans; Hyperglycemia; Infusions, Intravenous; Insulin; Male; Middle Aged; Parenteral Nutrition, Total; Peptide Fragments; Placebos | 2004 |
Intravenous glucagon-like peptide 1 normalizes blood glucose after major surgery in patients with type 2 diabetes.
Hyperglycemia is a major risk factor for a poor outcome after major surgery in patients with type 2 diabetes. Intensive insulin treatment aiming at normoglycemia can markedly improve the survival of critically ill patients, but the broad clinical application is limited by its practicability and the risk of hypoglycemia. Therefore, the glucose-lowering effect of the incretin hormone glucagon-like peptide 1 (GLP-1) was investigated in patients with type 2 diabetes after major surgery.. Randomised clinical study.. A surgical unit of a university hospital.. Eight patients with type 2 diabetes (five men, three women; age, 49+/-15 yrs; body mass index, 28+/-3 kg/m; glycosylated hemoglobin, 8.0%+/-1.9%), who had undergone major surgical procedures, were studied between the second and the eighth postoperative day with the intravenous administration of GLP-1 (1.2 pmol x kg x min) and placebo over 8 hrs, each administered in randomized order in the fasting state. C-reactive protein concentrations of 4.9+/-4.2 mg/dL indicated a systemic inflammation. Blood was drawn in 30-min intervals for glucose (glucose oxidase), insulin, C-peptide, glucagon, and GLP-1 (specific immunoassays). Statistics were done with repeated-measures analysis of variance and Duncan's post hoc tests.. During the intravenous infusion of GLP-1, plasma glucose concentrations were significantly lowered, reaching the normoglycemic fasting glucose range within 150 mins, but they remained elevated during placebo infusion (p <.001). The GLP-1 infusion led to a significant increase of insulin secretion (p <.001 for insulin and C-peptide) and a suppression of glucagon secretion (p =.041). No hypoglycemic events were recorded during the experiments.. As far as can be concluded on the basis of our data with the infusion of GLP-1 over 8 hrs in eight patients, GLP-1 can be used to reduce glucose concentrations in patients with type 2 diabetes after major surgery. Topics: Adult; Aged; Analysis of Variance; Diabetes Mellitus, Type 2; Female; Glucagon; Glucagon-Like Peptide 1; Humans; Hyperglycemia; Hypoglycemic Agents; Infusions, Intravenous; Male; Middle Aged; Peptide Fragments; Postoperative Care; Postoperative Complications; Protein Precursors | 2004 |
One week's treatment with the long-acting glucagon-like peptide 1 derivative liraglutide (NN2211) markedly improves 24-h glycemia and alpha- and beta-cell function and reduces endogenous glucose release in patients with type 2 diabetes.
Glucagon-like peptide 1 (GLP-1) is potentially a very attractive agent for treating type 2 diabetes. We explored the effect of short-term (1 week) treatment with a GLP-1 derivative, liraglutide (NN2211), on 24-h dynamics in glycemia and circulating free fatty acids, islet cell hormone profiles, and gastric emptying during meals using acetaminophen. Furthermore, fasting endogenous glucose release and gluconeogenesis (3-(3)H-glucose infusion and (2)H(2)O ingestion, respectively) were determined, and aspects of pancreatic islet cell function were elucidated on the subsequent day using homeostasis model assessment and first- and second-phase insulin response during a hyperglycemic clamp (plasma glucose approximately 16 mmol/l), and, finally, on top of hyperglycemia, an arginine stimulation test was performed. For accomplishing this, 13 patients with type 2 diabetes were examined in a double-blind, placebo-controlled crossover design. Liraglutide (6 micro g/kg) was administered subcutaneously once daily. Liraglutide significantly reduced the 24-h area under the curve for glucose (P = 0.01) and glucagon (P = 0.04), whereas the area under the curve for circulating free fatty acids was unaltered. Twenty-four-hour insulin secretion rates as assessed by deconvolution of serum C-peptide concentrations were unchanged, indicating a relative increase. Gastric emptying was not influenced at the dose of liraglutide used. Fasting endogenous glucose release was decreased (P = 0.04) as a result of a reduced glycogenolysis (P = 0.01), whereas gluconeogenesis was unaltered. First-phase insulin response and the insulin response to an arginine stimulation test with the presence of hyperglycemia were markedly increased (P < 0.001), whereas the proinsulin/insulin ratio fell (P = 0.001). The disposition index (peak insulin concentration after intravenous bolus of glucose multiplied by insulin sensitivity as assessed by homeostasis model assessment) almost doubled during liraglutide treatment (P < 0.01). Both during hyperglycemia per se and after arginine exposure, the glucagon responses were reduced during liraglutide administration (P < 0.01 and P = 0.01). Thus, 1 week's treatment with a single daily dose of the GLP-1 derivative liraglutide, operating through several different mechanisms including an ameliorated pancreatic islet cell function in individuals with type 2 diabetes, improves glycemic control throughout 24 h of daily living, i.e., prandial and nocturnal periods. This Topics: Circadian Rhythm; Cross-Over Studies; Delayed-Action Preparations; Diabetes Mellitus, Type 2; Double-Blind Method; Drug Administration Schedule; Female; Gastric Emptying; Glucagon; Glucagon-Like Peptide 1; Glucose; Hormones; Humans; Hypoglycemic Agents; Insulin Resistance; Islets of Langerhans; Liraglutide; Male; Middle Aged | 2004 |
Orlistat augments postprandial increases in glucagon-like peptide 1 in obese type 2 diabetic patients.
Orlistat leads to improved glycemic control in obese type 2 diabetic patients, which is attributed to decreased insulin resistance associated with weight loss. Glucagon-like peptide 1 (GLP-1) and glucose-dependent insulinotropic peptide (GIP) are gut hormones that are secreted in response to food intake, and they both stimulate insulin secretion. Orlistat decreases fat absorption and increases intestinal fat content, which may lead to increased secretion of these peptides. In this pilot study, we tested the hypothesis that increased levels of these intestinal hormones may be involved in the improvement of postprandial hyperglycemia observed previously with orlistat in type 2 diabetic patients.. A total of 29 type 2 diabetic patients, who were not taking insulin or alpha-glucosidase inhibitors, were enrolled in the study. On a crossover and single-blind design, after an overnight fasting, the patients received 120-mg orlistat or placebo capsules, followed by a standard 600-kcal mixed meal that contained 38% fat. At baseline and 60 min after the meal, blood samples were obtained for the measurement of GLP-1, GIP, insulin, C-peptide, triglycerides, free fatty acids, and glucose.. All measured parameters increased significantly in response to the mixed meal compared with baseline, both with orlistat or placebo. When compared with the placebo, the orlistat administration resulted in a significantly enhanced postprandial increase in GLP-1 and C-peptide levels and attenuated the postprandial rise in glucose and triglycerides.. The results of this study suggest that apart from decreasing insulin resistance as a result of weight loss, orlistat may increase postprandial GLP-1 levels, thereby enhancing the insulin secretory response to the meal and blunting the postprandial rise in glucose in type 2 diabetic patients. Increased GLP-1 levels, which lead to decreased food intake, may also contribute to the weight loss that is associated with the use of this drug. Topics: Adult; Aged; Anti-Obesity Agents; Cross-Over Studies; Diabetes Mellitus; Diabetes Mellitus, Type 2; Female; Gastric Inhibitory Polypeptide; Glucagon; Glucagon-Like Peptide 1; Humans; Insulin; Lactones; Male; Middle Aged; Obesity; Orlistat; Peptide Fragments; Protein Precursors; Single-Blind Method; Weight Loss | 2004 |
Improved glycemic control with no weight increase in patients with type 2 diabetes after once-daily treatment with the long-acting glucagon-like peptide 1 analog liraglutide (NN2211): a 12-week, double-blind, randomized, controlled trial.
Liraglutide is a long-acting glucagon-like peptide 1 analog designed for once daily injection. This study assessed the efficacy and safety of liraglutide after 12 weeks of treatment in type 2 diabetic patients.. A double-blind, randomized, parallel-group, placebo-controlled trial with an open-label comparator arm was conducted among 193 outpatients with type 2 diabetes. The mean age was 56.6 years and the mean HbA(1c) was 7.6% across the treatment groups. Patients were randomly assigned to one of five fixed-dosage groups of liraglutide (0.045, 0.225, 0.45, 0.60, or 0.75 mg), placebo, or open-label sulfonylurea (glimepiride, 1-4 mg). The primary end point was HbA(1c) after 12 weeks; secondary end points were fasting serum glucose, fasting C-peptide, fasting glucagon, fasting insulin, beta-cell function, body weight, adverse events, and hypoglycemic episodes.. A total of 190 patients were included in the intention-to-treat (ITT) analysis. HbA(1c) decreased in all but the lowest liraglutide dosage group. In the 0.75-mg liraglutide group, HbA(1c) decreased by 0.75 percentage points (P < 0.0001) and fasting glucose decreased by 1.8 mmol/l (P = 0.0003) compared with placebo. Improvement in glycemic control was evident after 1 week. Body weight decreased by 1.2 kg in the 0.45-mg liraglutide group (P = 0.0184) compared with placebo. The proinsulin-to-insulin ratio decreased in the 0.75-mg liraglutide group (-0.18; P = 0.0244) compared with placebo. Patients treated with glimepiride had decreased HbA(1c) and fasting glucose, but slightly increased body weight. No safety issues were raised for liraglutide; observed adverse events were mild and transient.. A once-daily dose of liraglutide provides efficacious glycemic control and is not associated with weight gain. Adverse events with the drug are mild and transient, and the risk of hypoglycemia is negligible. Topics: Blood Glucose; Body Weight; Delayed-Action Preparations; Diabetes Mellitus, Type 2; Double-Blind Method; Drug Administration Schedule; Female; Glucagon; Glucagon-Like Peptide 1; Glycated Hemoglobin; Humans; Insulin; Liraglutide; Male; Middle Aged; Placebos; Treatment Outcome | 2004 |
Effect of variations in small intestinal glucose delivery on plasma glucose, insulin, and incretin hormones in healthy subjects and type 2 diabetes.
The determinants of postprandial blood glycemia are controversial. We assessed the effects of variations in the initial rate of small intestinal glucose delivery on blood glucose, plasma insulin, and incretin responses in both health and type 2 diabetes. Eight controls and eight patients with type 2 diabetes managed by diet alone underwent paired studies. On both days subjects received an intraduodenal glucose infusion (t = 0-120 min); on one day the infusion rate was variable, being more rapid initially (3 kcal/min) between t = 0 and 15 min and slower (0.71 kcal/min) subsequently (t = 15-120 min), whereas on the other day, the infusion rate was constant (1 kcal/min) from t = 0 to 120 min (i.e. on both days 120 kcal of glucose were administered). Between t = 0-180 min blood glucose, plasma insulin and plasma glucose-dependent insulin-releasing polypeptide were greater with the variable, compared with the constant, infusion. Between t = 0 and 30 min the magnitude of the rise in plasma glucagon-like peptide-1 was greater with the variable, compared with the constant infusion (P < 0.01, both groups). We conclude that modest variations in the initial rate of duodenal glucose entry may have profound effects on subsequent glycemic, insulin, and incretin responses. Topics: Biological Availability; Blood Glucose; Case-Control Studies; Diabetes Mellitus, Type 2; Duodenum; Female; Gastric Inhibitory Polypeptide; Glucagon; Glucagon-Like Peptide 1; Glucose; Humans; Insulin; Intestine, Small; Middle Aged; Osmolar Concentration; Peptide Fragments; Protein Precursors | 2004 |
Additive effects of glucagon-like peptide 1 and pioglitazone in patients with type 2 diabetes.
To evaluate the effect of combination therapy with pioglitazone and glucagon-like peptide (GLP)-1 in patients with type 2 diabetes.. Eight patients with type 2 diabetes (BMI 32.7 +/- 1.3 kg/m(2) and fasting plasma glucose 13.5 +/- 1.2 mmol/l) underwent four different treatment regimens in random order: saline therapy, monotherapy with continuous subcutaneous infusion of GLP-1 (4.8 pmol x kg(-1) x min(-1)), monotherapy with pioglitazone (30-mg tablet of Actos), and combination therapy with GLP-1 and pioglitazone. The observation period was 48 h. End points were plasma levels of glucose, insulin, glucagon, free fatty acids (FFAs), and sensation of appetite.. Fasting plasma glucose decreased from 13.5 +/- 1.2 mmol/l (saline) to 11.7 +/- 1.2 (GLP-1) and 11.5 +/- 1.2 (pioglitazone) and further decreased to 9.9 +/- 1.0 (combination) (P < 0.001). Eight-hour mean plasma glucose levels were reduced from 13.7 +/- 1.1 mmol/l (saline) to 10.6 +/- 1.0 (GLP-1) and 12.0 +/- 1.2 (pioglitazone) and were further reduced to 9.5 +/- 0.8 (combination) (P < 0.0001). Insulin levels increased during monotherapy with GLP-1 compared with monotherapy with pioglitazone (P < 0.01). Glucagon levels were reduced in GLP-1 and combination therapy compared with saline and monotherapy with pioglitazone (P < 0.01). FFAs during breakfast (area under the curve, 0-3 h) were reduced in combination therapy compared with saline (P = 0.03). Sensation of appetite was reduced during monotherapy with GLP-1 and combination therapy (P < 0.05).. GLP-1 and pioglitazone show an additive glucose-lowering effect. A combination of the two agents may, therefore, be a valuable therapeutic approach for the treatment of type 2 diabetes. Topics: Aged; Blood Glucose; Diabetes Mellitus, Type 2; Drug Therapy, Combination; Glucagon; Glucagon-Like Peptide 1; Glycated Hemoglobin; Humans; Hypoglycemic Agents; Insulin; Male; Middle Aged; Peptide Fragments; Pioglitazone; Protein Precursors; Thiazolidinediones | 2004 |
The effect of liraglutide, a long-acting glucagon-like peptide 1 derivative, on glycemic control, body composition, and 24-h energy expenditure in patients with type 2 diabetes.
Glucagon-like peptide (GLP)-1 is a gut hormone that exerts incretin effects and suppresses food intake in humans, but its therapeutic use is limited due to its short half-life. This was a randomized, double-blind, parallel-group, placebo-controlled trial investigating the effect of the long-acting GLP-1 derivative liraglutide (NN2211) on glycemic control, body weight, body composition, and 24-h energy expenditure in obese subjects with type 2 diabetes.. Thirty-three patients (mean +/- SD) aged 60.0 +/- 9.5 years, with HbA(1c) 7.5 +/- 1.2% and BMI 36.6 +/- 4.1 kg/m(2), were randomized to treatment with a single daily subcutaneous dose of 0.6 mg liraglutide (n = 21) or placebo (n = 12) for 8 weeks. In addition to weight and glycemic parameters, body composition was assessed by dual-energy X-ray absorptiometry (DEXA) scanning and 24-h energy expenditure in a respiratory chamber.. After 8 weeks, liraglutide reduced fasting serum glucose (liraglutide, -1.90 mmol/l, and placebo, 0.27 mmol/l; P = 0.002) and HbA(1c) (liraglutide, -0.33%, and placebo, 0.47%; P = 0.028) compared with placebo. No change in body weight was detected (liraglutide, -0.7 kg, and placebo, -0.9 kg; P = 0.756). There was a nonsignificant trend toward a decrease in total fat mass (liraglutide, -0.98%, and placebo, -0.12%; P = 0.088) and toward an increase in lean body mass (liraglutide, 1.02%, and placebo, 0.23%; P = 0.118) in the liraglutide group compared with the placebo group. Twenty-four-hour energy expenditure was unaffected by the treatment (liraglutide, -12.6 kJ/h, and placebo, -13.7 kJ/h; P = 0.799).. Eight weeks of 0.6-mg liraglutide treatment significantly improved glycemic control without increasing weight in subjects with type 2 diabetes compared with those on placebo. No influence on 24-h energy expenditure was detected. Topics: Blood Glucose; Body Composition; Body Mass Index; Body Weight; Diabetes Mellitus, Type 2; Energy Metabolism; Female; Glucagon; Glucagon-Like Peptide 1; Glycated Hemoglobin; Humans; Liraglutide; Male; Middle Aged; Placebos | 2004 |
Effects of glucagon-like peptide-1 on endothelial function in type 2 diabetes patients with stable coronary artery disease.
GLP-1 stimulates insulin secretion, suppresses glucagon secretion, delays gastric emptying, and inhibits small bowel motility, all actions contributing to the anti-diabetogenic peptide effect. Endothelial dysfunction is strongly associated with insulin resistance and type 2 diabetes mellitus and may cause the angiopathy typifying this debilitating disease. Therefore, interventions affecting both endothelial dysfunction and insulin resistance may prove useful in improving survival in type 2 diabetes patients. We investigated GLP-1's effect on endothelial function and insulin sensitivity (S(I)) in two groups: 1) 12 type 2 diabetes patients with stable coronary artery disease and 2) 10 healthy subjects with normal endothelial function and S(I). Subjects underwent infusion of recombinant GLP-1 or saline in a random crossover study. Endothelial function was measured by postischemic FMD of brachial artery, using ultrasonography. S(I) [in (10(-4) dl.kg(-1).min(-1))/(muU/ml)] was measured by hyperinsulinemic isoglycemic clamp technique. In type 2 diabetic subjects, GLP-1 infusion significantly increased relative changes in brachial artery diameter from baseline FMD(%) (3.1 +/- 0.6 vs. 6.6 +/- 1.0%, P < 0.05), with no significant effects on S(I) (4.5 +/- 0.8 vs. 5.2 +/- 0.9, P = NS). In healthy subjects, GLP-1 infusion affected neither FMD(%) (11.9 +/- 0.9 vs. 10.3 +/- 1.0%, P = NS) nor S(I) (14.8 +/- 1.8 vs. 11.6 +/- 2.0, P = NS). We conclude that GLP-1 improves endothelial dysfunction but not insulin resistance in type 2 diabetic patients with coronary heart disease. This beneficial vascular effect of GLP-1 adds yet another salutary property of the peptide useful in diabetes treatment. Topics: Adult; Brachial Artery; Coronary Circulation; Coronary Disease; Coronary Vessels; Cross-Over Studies; Diabetes Mellitus, Type 2; Diabetic Angiopathies; Endothelial Cells; Endothelium, Vascular; Glucagon; Glucagon-Like Peptide 1; Glucagon-Like Peptide-1 Receptor; Humans; Insulin; Male; Middle Aged; Nitroglycerin; Peptide Fragments; Pilot Projects; Protein Precursors; Receptors, Glucagon; Regional Blood Flow; Vasodilation | 2004 |
Initial experience with GLP-1 treatment on metabolic control and myocardial function in patients with type 2 diabetes mellitus and heart failure.
Congestive heart failure (CHF) is a serious disease with a poor prognosis. Diabetes is an independent risk factor for CHF, probably in part due to disturbances in myocardial metabolism. Glucagon-like peptide-1 (GLP-1) causes glucose-dependent secretion of insulin, improving glycaemic control. In turn, this may improve myocardial metabolism and myocardial function. The aim of the present study was to assess the feasibility and safety of three days' infusion of recombinant GLP-1 in an open observational study in six patients with type 2 diabetes and CHF. The study included assessment of myocardial function. There were no major complications of the infusion, and all patients completed the study protocol. Some improvement was observed in glycaemic state, and there was an insignificant trend towards improved myocardial function. It is concluded that GLP-1 deserves further evaluation in such patients. Topics: Blood Glucose; C-Peptide; Diabetes Mellitus, Type 2; Echocardiography, Doppler; Exercise Test; Glucagon; Glucagon-Like Peptide 1; Heart; Heart Failure; Humans; Infusions, Parenteral; Injections, Subcutaneous; Insulin; Male; Myocardial Contraction; Pilot Projects; Recombinant Proteins; Time Factors | 2004 |
Differential effects of saturated and monounsaturated fats on postprandial lipemia and glucagon-like peptide 1 responses in patients with type 2 diabetes.
Postprandial lipemia is important in the development of coronary artery disease because of elevated postprandial triacylglycerol-rich plasma lipoproteins and suppressed HDL-cholesterol concentrations. We showed in healthy subjects a possible association between postprandial lipid metabolism and the responses of the duodenal incretin hormones glucagon-like peptide 1 (GLP-1) and gastric inhibitory polypeptide after meals rich in saturated and monounsaturated fatty acids (oleic acid), respectively.. The objective was to compare the postprandial responses (8 h) of glucose, insulin, fatty acids, triacylglycerol, gastric inhibitory polypeptide, and GLP-1 to saturated- and monounsaturated-rich test meals.. Twelve overweight patients with type 2 diabetes ingested 3 meals randomly: an energy-free soup with 50 g carbohydrate (control meal), the control meal plus 100 g butter, and the control meal plus 80 g olive oil. Triacylglycerol responses were measured in total plasma and in a chylomicron-rich and a chylomicron-poor fraction.. No significant differences in the glucose, insulin, or fatty acid responses to the 2 fat-rich meals were seen. The plasma triacylglycerol and chylomicron triacylglycerol responses were highest after the butter meal. HDL-cholesterol concentrations decreased significantly after the butter meal but did not change significantly after the olive oil meal. GLP-1 responses were highest after the olive oil meal.. Olive oil induced lower triacylglycerol concentrations and higher HDL-cholesterol concentrations than did butter, without eliciting significant changes in glucose, insulin, or fatty acids. Furthermore, olive oil induced higher concentrations of GLP-1, which may indicate a relation between fatty acid composition, incretin responses, and triacylglycerol metabolism postprandially in patients with type 2 diabetes. Topics: Area Under Curve; Blood Glucose; Butter; Cholesterol, HDL; Chylomicrons; Coronary Artery Disease; Diabetes Mellitus; Diabetes Mellitus, Type 2; Fatty Acids; Fatty Acids, Monounsaturated; Female; Gastric Inhibitory Polypeptide; Glucagon; Glucagon-Like Peptide 1; Humans; Insulin; Male; Middle Aged; Obesity; Olive Oil; Peptide Fragments; Plant Oils; Postprandial Period; Protein Precursors; Triglycerides | 2003 |
Differential effects of acute and extended infusions of glucagon-like peptide-1 on first- and second-phase insulin secretion in diabetic and nondiabetic humans.
The purpose of this study was to determine whether an extended infusion of the incretin hormone glucagon-like peptide 1 (GLP-1) has a greater effect to promote insulin secretion in type 2 diabetic subjects than acute administration of the peptide.. Nine diabetic subjects and nine nondiabetic volunteers of similar age and weight were studied in identical protocols. First-phase insulin release (FPIR; the incremental insulin response in the first 10 min after the intravenous glucose bolus) and second-phase insulin release (SPIR; the incremental insulin response from 10-60 min after intravenous glucose) were measured during three separate intravenous glucose tolerance tests (IVGTTs): 1). without GLP-1 (control); 2). with acute administration of GLP-1 as a square wave starting just before glucose administration; and 3). with an extended infusion of GLP-1 for 3 h before and during the IVGTT.. In the subjects with diabetes, FPIR was severely impaired-a defect that was only modestly improved by acute administration of GLP-1 (197 +/- 97 vs. 539 +/- 218 pmol/l. min, P < 0.05), while SPIR was substantially increased (1952 +/- 512 vs. 8072 +/- 1664 pmol/l. min, P < 0.05). In contrast, the 3-h preinfusion of GLP-1 normalized fasting hyperglycemia (7.9 +/- 0.5 vs. 5.2 +/- 0.6, P < 0.05), increased FPIR by 5- to 6-fold (197 +/- 97 vs. 1141 +/- 409 pmol/l. min, P < 0.05), and augmented SPIR significantly (1952 +/- 512 vs. 4026 +/- 851 pmol/l. min, P < 0.05), but to a lesser degree than the acute administration of GLP-1. In addition, only the 3-h GLP-1 preinfusion significantly improved intravenous glucose tolerance (K(g) control 0.61 +/- 0.04, acute infusion 0.71 +/- 0.04, P = NS; 3-h infusion 0.92 +/- 0.08%/min, P < 0.05). These findings were also noted in the nondiabetic subjects in whom acute administration of GLP-1 significantly increased SPIR relative to the control IVGTT (9439 +/- 2885 vs. 31553 +/- 11660 pmol/l. min, P < 0.001) with less effect on FPIR (3221 +/- 918 vs. 4917 +/- 1614 pmol/l. min, P = 0.075), while the 3-h preinfusion of GLP-1 significantly increased both FPIR (3221 +/- 918 vs. 7948 +/- 2647 pmol/l. min, P < 0.01) and SPIR (9439 +/- 2885 vs. 21997 +/- 9849 pmol/l. min, P < 0.03).. Extended administration of GLP-1 not only augments glucose-stimulated insulin secretion, but also shifts the dynamics of the insulin response to earlier release in both diabetic and nondiabetic humans. The restitution of some FPIR in subjects with type 2 diabetes is associated with significantly improved glucose tolerance. These findings demonstrate the benefits of a 3-h infusion of GLP-1 on beta-cell function beyond those of an acute insulin secretagogue, and support the development of strategies using continuous or prolonged GLP-1 receptor agonism for treating diabetic patients. Topics: Aged; Blood Glucose; Diabetes Mellitus, Type 2; Female; Glucagon; Glucagon-Like Peptide 1; Humans; Infusions, Intravenous; Insulin; Insulin Secretion; Islets of Langerhans; Male; Middle Aged; Peptide Fragments; Protein Precursors | 2003 |
Normalization of glucose concentrations and deceleration of gastric emptying after solid meals during intravenous glucagon-like peptide 1 in patients with type 2 diabetes.
The effects of different i.v. doses of glucagon-like peptide 1 (GLP-1) on glucose homeostasis and gastric emptying were compared in patients with type 2 diabetes. Twelve patients with type 2 diabetes received three different infusion rates of GLP-1 (0.4, 0.8, and 1.2 pmol/kg x min) or placebo in the fasting state and after a solid test meal (containing [(13)C]octanoic acid). Blood was drawn for glucose, insulin, C-peptide, glucagon, and GLP-1 determinations. The gastric emptying rate was calculated from the (13)CO(2) excretion rates in breath samples. Statistics were determined using repeated measures ANOVA and Duncan's post hoc test. Plasma glucose concentrations were equally normalized with all GLP-1 doses (P < 0.001). Insulin and C-peptide concentrations dose-dependently rose during GLP-1 infusion in the fasting state (P < 0.05), but were dose-dependently reduced by GLP-1 after meal ingestion (P = 0.0031 and 0.0074, respectively). Glucagon secretion was suppressed with GLP-1. Gastric emptying was decelerated by GLP-1 in a dose-dependent fashion (P < 0.001). Despite a dose-dependent stimulation of insulin secretion, glucose normalization can be achieved even with 0.4 pmol GLP-1/kg x min. Due to the dose-dependent inhibition of gastric emptying, lower GLP-1 doses than previously used may be as suitable for glucose control in patients with type 2 diabetes. Topics: Aged; Blood Glucose; Diabetes Mellitus, Type 2; Dose-Response Relationship, Drug; Fasting; Female; Gastric Emptying; Glucagon; Glucagon-Like Peptide 1; Humans; Injections, Intravenous; Male; Middle Aged; Osmolar Concentration; Peptide Fragments; Postprandial Period; Protein Precursors; Time Factors | 2003 |
The GLP-1 derivative NN2211 restores beta-cell sensitivity to glucose in type 2 diabetic patients after a single dose.
Glucagon-like peptide 1 (GLP-1) stimulates insulin secretion in a glucose-dependent manner, but its short half-life limits its therapeutic potential. We tested NN2211, a long-acting GLP-1 derivative, in 10 subjects with type 2 diabetes (means +/- SD: age 63 +/- 8 years, BMI 30.1 +/- 4.2 kg/m(2), HbA(1c) 6.5 +/- 0.8%) in a randomized, double-blind, placebo-controlled, crossover study. A single injection (7.5 micro g/kg) of NN2211 or placebo was administered 9 h before the study. beta-cell sensitivity was assessed by a graded glucose infusion protocol, with glucose levels matched over the 5-12 mmol/l range. Insulin secretion rates (ISRs) were estimated by deconvolution of C-peptide levels. Findings were compared with those in 10 nondiabetic volunteers during the same glucose infusion protocol. In type 2 diabetic subjects, NN2211, in comparison with placebo, increased insulin and C-peptide levels, the ISR area under the curve (AUC) (1,130 +/- 150 vs. 668 +/- 106 pmol/kg; P < 0.001), and the slope of ISR versus plasma glucose (1.26 +/- 0.36 vs. 0.54 +/- 0.18 pmol x l[min(-1) x mmol(-1) x kg(-1)]; P < 0.014), with values similar to those of nondiabetic control subjects (ISR AUC 1,206 +/- 99; slope of ISR versus plasma glucose, 1.44 +/- 0.18). The long-acting GLP-1 derivative, NN2211, restored beta-cell responsiveness to physiological hyperglycemia in type 2 diabetic subjects. Topics: Aged; Blood Glucose; Cross-Over Studies; Diabetes Mellitus, Type 2; Double-Blind Method; Female; Glucagon; Glucagon-Like Peptide 1; Glucose Clamp Technique; Humans; Liraglutide; Male; Middle Aged; Peptide Fragments; Placebos; Protein Precursors; Reference Values | 2003 |
Effect of lipase inhibition on gastric emptying of, and the glycemic and incretin responses to, an oil/aqueous drink in type 2 diabetes mellitus.
This study examined the effects of the lipase inhibitor, orlistat, on gastric emptying of, and the glycemic and incretin hormone responses to, a drink containing oil and glucose components in patients with type 2 diabetes. Seven patients (aged 58 +/- 5 yr), managed by diet alone, consumed 60 ml olive oil (labeled with 20 MBq (99m)Tc-V-thiocyanate) and 300 ml water containing 75 g glucose (labeled with 6 MBq (67)Ga-EDTA), on two occasions, with and without 120 mg orlistat, positioned in the left lateral decubitus position with their back against a gamma camera. Venous blood samples, for measurement of blood glucose and plasma insulin, glucagon-like peptide-1 and glucose-dependent insulintropic polypeptide were obtained immediately before, and after, the drink. Gastric emptying of both oil (P < 0.001) and glucose (P < 0.0005) was faster after orlistat compared with control. Postprandial blood glucose (P < 0.001) and plasma insulin (P < 0.05) were substantially greater after orlistat compared with control. In contrast, plasma glucagon-like peptide-1 (P < 0.005) and glucose-dependent insulintropic polypeptide (P < 0.05) were less after orlistat. In conclusion, inhibition of fat digestion, by orlistat, may exacerbate postprandial glycemia, as a result of more rapid gastric emptying and a diminished incretin response. Topics: Autonomic Nervous System; Blood Glucose; Diabetes Mellitus, Type 2; Dietary Fats; Enzyme Inhibitors; Female; Gastric Emptying; Gastric Inhibitory Polypeptide; Gastric Mucosa; Glucagon; Glucagon-Like Peptide 1; Glucagon-Like Peptides; Glucose; Hemodynamics; Humans; Insulin; Lactones; Lipase; Male; Middle Aged; Orlistat; Peptide Fragments; Peptides | 2003 |
No hypoglycemia after subcutaneous administration of glucagon-like peptide-1 in lean type 2 diabetic patients and in patients with diabetes secondary to chronic pancreatitis.
Glucagon-like peptide 1 (GLP-1) is a proglucagon derivative secreted primarily from the L-cells of the small intestinal mucosa in response to the ingestion of meals. GLP-1 stimulates insulin secretion and inhibits glucagon secretion. It has previously been shown that intravenous or subcutaneous administration of GLP-1 concomitant with intravenous glucose results in hypoglycemia in healthy subjects. Because GLP-1 is also effective in type 2 diabetic patients and is currently being evaluated as a therapeutic agent, it is important to investigate whether GLP-1 may cause hypoglycemia in such patients. We have previously shown that GLP-1 does not cause hypoglycemia in obese type 2 diabetic patients with insulin resistance amounting to 5.4 +/- 1.1 according to homeostasis model assessment (HOMA). In this study, we investigated diabetic patients with normal or close to normal insulin sensitivity.. Eight lean type 2 diabetic patients (group 1) aged 60 years (range 50-72) with BMI 23.1 kg/m(2) (20.3-25.5) and HbA(1c) 8.0% (6.9-11.4) and eight patients with type 2 diabetes secondary to chronic pancreatitis (group 2) aged 52 years (41-62) with BMI 21.9 kg/m(2) (17.6-27.3) and HbA(1c) 7.8% (6.2-12.4) were given a subcutaneous injection of 1.5 nmol GLP-1/kg body wt. Then, 15 min later, at the time of peak GLP-1 concentration, plasma glucose (PG) was raised to 15 mmol/l with an intravenous glucose bolus. HOMA (mean +/- SEM) showed insulin resistance amounting to 1.9 +/- 0.3 and 1.7 +/- 0.5 in the two groups, respectively.. In both groups, PG decreased rapidly and stabilized at 7.5 mmol/l (range 3.9-10.1) and 7.2 mmol/l (3.1-10.9) in groups 1 and 2, respectively, after 90 min. Neither symptoms of hypoglycemia nor biochemical hypoglycemia were observed in any patient.. We conclude that a GLP-1-based therapy would not be expected to be associated with an increased risk of hypoglycemia in insulin-sensitive type 2 diabetic patients. Topics: Adult; Aged; Blood Glucose; C-Peptide; Chronic Disease; Diabetes Mellitus; Diabetes Mellitus, Type 2; Glucagon; Glucagon-Like Peptide 1; Glycated Hemoglobin; Humans; Hypoglycemia; Injections, Subcutaneous; Insulin; Kinetics; Middle Aged; Pancreatitis; Peptide Fragments; Protein Precursors | 2003 |
Effects of 3 months of continuous subcutaneous administration of glucagon-like peptide 1 in elderly patients with type 2 diabetes.
Glucagon-like peptide 1 (GLP-1) is an insulinotropic gut hormone that, when given exogenously, may be a useful agent in the treatment of type 2 diabetes. We conducted a 3-month trial to determine the efficacy and safety of GLP-1 in elderly diabetic patients.. A total of 16 patients with type 2 diabetes who were being treated with oral hypoglycemic agents were enrolled. Eight patients (aged 75 +/- 2 years, BMI 27 +/- 1 kg/m(2)) remained on usual glucose-lowering therapy and eight patients (aged 73 +/- 1 years, BMI 27 +/- 1 kg/m(2)), after discontinuing hypoglycemic medications, received GLP-1 delivered by continuous subcutaneous infusion for 12 weeks. The maximum dose was 120 pmol x kg(-1). h(-1). Patients recorded their capillary blood glucose (CBG) levels (four times per day, 3 days per week) and whenever they perceived hypoglycemic symptoms. The primary end points were HbA(1c) and CBG determinations. Additionally, changes in beta-cell sensitivity to glucose, peripheral tissue sensitivity to insulin, and changes in plasma ghrelin levels were examined.. HbA(1c) levels (7.1%) and body weight were equally maintained in both groups. The usual treatment group had a total of 87 CBG measurements of Topics: Aged; Blood Glucose; C-Peptide; Diabetes Mellitus, Type 2; Drug Implants; Fasting; Fatty Acids, Nonesterified; Female; Glucagon; Glucagon-Like Peptide 1; Glycated Hemoglobin; Humans; Injections, Subcutaneous; Insulin; Male; Peptide Fragments; Protein Precursors; Treatment Outcome | 2003 |
The pathophysiology of diabetes involves a defective amplification of the late-phase insulin response to glucose by glucose-dependent insulinotropic polypeptide-regardless of etiology and phenotype.
The effect of the insulinotropic incretin hormone, glucagon-like peptide-1 (GLP-1), is preserved in typical middle-aged, obese, insulin-resistant type 2 diabetic patients, whereas a defective amplification of the so-called late-phase plasma insulin response (20-120 min) to glucose by the other incretin hormone, glucose-dependent insulinotropic polypeptide (GIP), is seen in these patients. The aim of the present investigation was to evaluate plasma insulin and C-peptide responses to GLP-1 and GIP in five groups of diabetic patients with etiology and phenotype distinct from the obese type 2 diabetic patients. We studied (six in each group): 1) patients with diabetes mellitus secondary to chronic pancreatitis; 2) lean type 2 diabetic patients (body mass index < 25 kg/m(2)); 3) patients with latent autoimmune diabetes in adults; 4) diabetic patients with mutations in the HNF-1alpha gene [maturity-onset diabetes of the young (MODY)3]; and 5) newly diagnosed type 1 diabetic patients. All participants underwent three hyperglycemic clamps (2 h, 15 mM) with continuous infusion of saline, 1 pmol GLP-1 (7-36)amide/kg body weight.min or 4 pmol GIP pmol/kg body weight.min. The early-phase (0-20 min) plasma insulin response tended to be enhanced by both GIP and GLP-1, compared with glucose alone, in all five groups. In contrast, the late-phase (20-120 min) plasma insulin response to GIP was attenuated, compared with the plasma insulin response to GLP-1, in all five groups. Significantly higher glucose infusion rates were required during the late phase of the GLP-1 stimulation, compared with the GIP stimulation. In conclusion, lack of GIP amplification of the late-phase plasma insulin response to glucose seems to be a consequence of diabetes mellitus, characterizing most, if not all, forms of diabetes. Topics: Adult; Aged; Blood Glucose; C-Peptide; Chronic Disease; Diabetes Mellitus, Type 1; Diabetes Mellitus, Type 2; DNA-Binding Proteins; Female; Gastric Inhibitory Polypeptide; Glucagon; Glucagon-Like Peptide 1; Glucagon-Like Peptides; Glucose; Hepatocyte Nuclear Factor 1; Hepatocyte Nuclear Factor 1-alpha; Hepatocyte Nuclear Factor 1-beta; Humans; Hyperglycemia; Insulin; Islets of Langerhans; Male; Middle Aged; Neurotransmitter Agents; Nuclear Proteins; Pancreatitis; Peptide Fragments; Phenotype; Protein Precursors; Transcription Factors | 2003 |
Recombinant glucagon-like peptide-1 (7-36 amide) lowers fasting serum glucose in a broad spectrum of patients with type 2 diabetes.
To evaluate the safety and efficacy of various doses of recombinant glucagon-like peptide-1 (7-36) amide (rGLP-1) administered subcutaneously (s. c.) via bolus injection or continuous infusion to lower fasting serum glucose (FSG) levels in subjects with type 2 diabetes treated by diet, hypoglycemic drugs, or insulin injection.. rGLP-1 was administered s. c. to 40 type 2 diabetics currently treated by diet, sulfonylurea (SU), metformin, or insulin in a double-blind, placebo-controlled, cross-over trial; preexisting treatments were continued during the study. In the bolus injection protocol, 32 subjects (8 from each of the 4 treatment groups) received 0.0, 0.5, 1.0, and 1.5 nmol rGLP-1/kg per injection (two injections, two hours apart, beginning one hour after the evening meal) in a randomized order on separate days. In the continuous s. c. infusion protocol, 40 subjects received rGLP-1 at 0.0, 1.5, 2.5, 3.5, and 4.5 pmol/kg/min for 10-12 hours overnight starting one hour after the evening meal. Fasting bloods were taken the morning after for glucose, insulin, and glucagon measurements.. In the diet, SU, and metformin cohorts, bolus rGLP-1 injections produced modest reductions in mean FSG levels, averaging 17.4 mg/dl (7.3-27.5; 95 % CI) at the highest dose (p < 0.001 vs. placebo). Reductions in FSG levels were greater by continuous infusion at up to 30.3 mg/dl (18.8 - 41.8; 95 % CI; p < 0.001 vs. placebo). The greatest reduction in mean FSG occurred in the SU cohort (up to 43.9 mg/dl, 24.7 - 63.1; 95 % CI; p < 0.001). rGLP-1 infusions resulted in significant increases in fasting plasma insulin and decreases in fasting plasma glucagon levels. There were no serious adverse events; GI-related symptoms were dose-related and more commonly associated with injections.. rGLP-1 (7-36) amide dose-dependently lowered FSG in a broad spectrum of type 2 diabetics when added to their existing treatment. Subcutaneous infusion was more effective than injection, and the combination with SU was more effective than with metformin. Topics: Blood Glucose; Cross-Over Studies; Diabetes Mellitus, Type 2; Double-Blind Method; Drug Therapy, Combination; Fasting; Glucagon; Glucagon-Like Peptide 1; Glucagon-Like Peptides; Humans; Hypoglycemic Agents; Insulin; Metformin; Peptide Fragments; Placebos; Recombinant Proteins; Sulfonylurea Compounds | 2003 |
Glucagon-like peptide-1 augments insulin-mediated glucose uptake in the obese state.
The insulinotropic hormone, glucagon-like peptide-1 (GLP-1), is being examined as a potential new agent for treatment in type 2 diabetic patients. Whereas the insulinotropic properties of this peptide are well established, another property of the hormone, an insulinomimetic effect per se, is controversial. In the normal glucose-tolerant lean state, it is difficult to demonstrate an insulinomimetic effect. The current study was conducted to examine whether GLP-1 has insulinomimetic effect in the obese state. Ten obese volunteers (body mass index, 34.6 +/- 0.8 kg/m(2)), whose ages were 32.5 +/- 3.0 yr, participated in two euglycemic clamp studies (n = 20 clamps) for 120 min. Five of the volunteers were females. The initial clamp was performed with a primed (0-10)-constant (10-60) infusion of GLP-1 at a final rate of 1.5 pmol x kg(-1) x min(-1). At 60 min, the GLP-1 infusion was terminated, and euglycemic was maintained from 60-120 min. After the GLP-1 study, each individual's plasma insulin level was measured. A second study was performed that was identical to the first, with the infusion of regular insulin in place of GLP-1. Insulin infusion rates were regulated in each individual to simulate plasma insulin levels produced during the GLP-1 infusion. The rate of disappearance of glucose was calculated for each subject. Fasting plasma insulin levels were similar between studies. In response to the GLP-1 infusion, with maintenance of plasma glucose level clamped at fasting level, significant increases in plasma insulin occurred in all subjects (P < 0.001). The insulin levels during the insulin infusion study were similar to that induced by GLP-1. The rate of disappearance of glucose (insulin-mediated glucose uptake) progressively increased in response to both the GLP-1 and insulin infusion. However, the rate of disappearance of glucose during the GLP-1 study was significantly higher (P = 0.033) than during the insulin study. We conclude that in insulin-resistant states, GLP-1 has insulinomimetic properties per se. Topics: Adult; Blood Glucose; C-Peptide; Diabetes Mellitus, Type 2; Drug Therapy, Combination; Fatty Acids, Nonesterified; Female; Glucagon; Glucagon-Like Peptide 1; Glucose; Glucose Clamp Technique; Humans; Hypoglycemic Agents; Insulin; Insulin Resistance; Male; Obesity; Peptide Fragments; Protein Precursors | 2002 |
The effects of miglitol on glucagon-like peptide-1 secretion and appetite sensations in obese type 2 diabetics.
Previous studies reported that administration of first generation alpha-glucosidase inhibitors (AGIs), such as voglibose or acarbose, produced exaggerated and sustained postprandial responses of glucagon-like peptide-1 (GLP-1), an incretin hormone from the enteroinsular axis, in healthy humans. Little is known about the postprandial release of GLP-1 after AGI therapy in diabetics. GLP-1 plays a role to mediate satiety. Any agent that substantially elevates GLP-1 levels may theoretically reduce hunger, increase satiation and limit food intake.. This study was performed to analyse the effect of miglitol, a more potent second generation AGI with fewer gastrointestinal side-effects, on the regulation of meal-related GLP-1 secretion and on the change of insulin-glucose dynamics as well as the release of gastric inhibitory polypeptide (GIP), another incretin hormone, after stimulation by an ordinary meal in obese type-2-diabetic subjects. Miglitol's subsequent influences on appetite sensations and food intake were also measured.. In total, 8 obese type-2-diabetic women were randomized to receive treatment with 100 mg of miglitol or placebo three times a day for 2 days (six doses total) in a double-blind fashion. On day 3 of each treatment period (miglitol or placebo), measurements of GLP-1, GIP, insulin and glucose were taken periodically during 3 h after eating a 720 kcal breakfast. Appetite ratings with visual analogue scales (VASs) were used to assess ingestive behaviour hourly just before breakfast and hourly after for 6 h until immediately before lunch. The number of tuna sandwiches eaten at lunch was used to measure food consumption.. The plasma GLP-1, glucose, insulin and GIP levels in response to the mixed meal were compared after the miglitol and placebo treatment. Miglitol effectively enhanced postprandial GLP-1 release and suppressed plasma GIP secretion. The ingestion of a mixed meal induced a remarkable rise in GLP-1 after miglitol as compared with placebo in overweight diabetic subjects. The meal-related rise in GLP-1 after miglitol was significantly greater at all time-points between 30 and 180 min than after the placebo. The postprandial incremental area under the curve for GLP-1 with miglitol treatment was about twofold that with the placebo. The GLP-1 level reached a maximum at 120 min after the mixed meal and steadily rose throughout the rest of the 3-h study period. In the miglitol-treated condition, the average caloric intake at lunch during a 30-min eating period was 12% lower (p < 0.05) as compared with that after the placebo in six out of the eight subjects who exhibited a GLP-1 rise after the breakfast meal by greater than 30% from the placebo-treated condition. Correspondingly, the average rating scores were significantly lower for hunger feelings and markedly greater for sensations of satiety under the miglitol treatment; beginning 2 and 3 h, respectively, before the lunch test.. Miglitol induced an enhanced and prolonged GLP-1 release at high physiological concentrations after ingesting an ordinary meal in glycaemic-controlled diabetics. The excessive postprandial GLP-1 elevation after miglitol therapy modified feeding behaviour and food intake, and thereby has potential value in regulating appetite and stabilizing body weight in obese type-2-diabetic patients. Topics: 1-Deoxynojirimycin; Adult; Aged; Appetite; Diabetes Mellitus; Diabetes Mellitus, Type 2; Double-Blind Method; Female; Gastric Inhibitory Polypeptide; Glucagon; Glucagon-Like Peptide 1; Glucosamine; Humans; Hypoglycemic Agents; Imino Pyranoses; Middle Aged; Obesity; Peptide Fragments; Postprandial Period; Protein Precursors | 2002 |
Bedtime administration of NN2211, a long-acting GLP-1 derivative, substantially reduces fasting and postprandial glycemia in type 2 diabetes.
Glucagon-like peptide 1 (GLP-1) is a potent glucose-lowering agent of potential interest for the treatment of type 2 diabetes. To evaluate actions of NN2211, a long-acting GLP-1 derivative, we examined 11 patients with type 2 diabetes, age 59 +/- 7 years (mean +/- SD), BMI 28.9 +/- 3.0 kg/m(2), HbA(1c) 6.5 +/- 0.6%, in a double-blind, placebo-controlled, crossover design. A single injection (10 microg/kg) of NN2211 was administered at 2300 h, and profiles of circulating insulin, C-peptide, glucose, and glucagon were monitored during the next 16.5 h. A standardized mixed meal was served at 1130 h. Efficacy analyses were performed for the fasting (7-8 h) and mealtime (1130-1530 h) periods. Insulin secretory rates (ISR) were estimated by C-peptide deconvolution analysis. Glucose pulse entrainment (6 mg x kg(-1) x min(-1) every 10 min) was evaluated by 1-min sampled measurements of insulin concentrations from 0930 to 1030 h and subsequent time series analysis of the insulin concentration profiles. All results are given as NN2211 versus placebo; statistical analyses were performed by analysis of variance. In the fasting state, plasma glucose was significantly reduced (6.9 +/- 1.0 vs. 8.1 +/- 1.0 mmol/l; P = 0.004), ISR was increased (179 +/- 70 vs. 163 +/- 66 pmol/min; P = 0.03), and plasma glucagon was unaltered (19 +/- 4 vs. 20 +/- 4 pg/ml; P = 0.17) by NN2211. Meal-related area under the curve (AUC)(1130-1530 h) for glucose was markedly reduced (30.6 +/- 2.4 vs. 39.9 +/- 7.3 mmol x l(-1) x h(-1); P < 0.001), ISR AUC(1130-1530 h) was unchanged (118 +/- 32 vs. 106 +/- 27 nmol; P = 0.13), but the increment (relative to premeal values) was increased (65 +/- 22 vs. 45 +/- 11 nmol; P = 0.04). Glucagon AUC(1130-1530 h) was suppressed (77 +/- 18 vs. 82 +/- 17 pmol x l(-1) x h(-1); P = 0.04). Gastric emptying was significantly delayed as assessed by AUC(1130-1530 h) of 3-ortho-methylglucose (400 +/- 84 vs. 440 +/- 70 mg x l(-1) x h(-1); P = 0.02). During pulse entrainment, there was a tendency to increased high frequency regularity of insulin release as measured by a greater spectral power and autocorrelation coefficient (0.05 < P < 0.10). The pharmacokinetic profile of NN2211, as assessed by blood samplings for up to 63 h postdosing, was as follows: T(1/2) = 10.0 +/- 3.5 h and T(max) = 12.4 +/- 1.7 h. Two patients experienced gastrointestinal side effects on the day of active treatment. In conclusion, the long-acting GLP-1 derivative NN2211 effectively reduces fast Topics: Aged; Blood Glucose; Cross-Over Studies; Delayed-Action Preparations; Diabetes Mellitus, Type 2; Drug Administration Schedule; Fasting; Female; Glucagon; Glucagon-Like Peptide 1; Homeostasis; Humans; Insulin; Insulin Secretion; Liraglutide; Male; Middle Aged; Osmolar Concentration; Postprandial Period | 2002 |
Effect of 6-week course of glucagon-like peptide 1 on glycaemic control, insulin sensitivity, and beta-cell function in type 2 diabetes: a parallel-group study.
Glucagon-like peptide 1 (GLP-1) has been proposed as a treatment for type 2 diabetes. We have investigated the long-term effects of continuous administration of this peptide hormone in a 6-week pilot study.. 20 patients with type 2 diabetes were alternately assigned continuous subcutaneous infusion of GLP-1 (n=10) or saline (n=10) for 6 weeks. Before (week 0) and at weeks 1 and 6, they underwent beta-cell function tests (hyperglycaemic clamps), 8 h profiles of plasma glucose, insulin, C-peptide, glucagon, and free fatty acids, and appetite and side-effect ratings on 100 mm visual analogue scales; at weeks 0 and 6 they also underwent dexascanning, measurement of insulin sensitivity (hyperinsulinaemic euglycaemic clamps), haemoglobin A(1c), and fructosamine. The primary endpoints were haemoglobin A(1c) concentration, 8-h profile of glucose concentration in plasma, and beta-cell function (defined as the first-phase response to glucose and the maximum insulin secretory capacity of the cell). Analyses were per protocol.. One patient assigned saline was excluded because no veins were accessible. In the remaining nine patients in that group, no significant changes were observed except an increase in fructosamine concentration (p=0.0004). In the GLP-1 group, fasting and 8 h mean plasma glucose decreased by 4.3 mmol/L and 5.5 mmol/L (p<0.0001). Haemoglobin A(1c) decreased by 1.3% (p=0.003) and fructosamine fell to normal values (p=0.0002). Fasting and 8 h mean concentrations of free fatty acids decreased by 30% and 23% (p=0.0005 and 0.01, respectively). Gastric emptying was inhibited, bodyweight decreased by 1.9 kg, and appetite was reduced. Both insulin sensitivity and beta-cell function improved (p=0.003 and p=0.003, respectively). No important side-effects were seen.. GLP-1 could be a new treatment for type 2 diabetes, though further investigation of the long-term effects of GLP-1 is needed. Topics: Blood Glucose; C-Peptide; Diabetes Mellitus, Type 2; Fasting; Female; Glucagon; Glucagon-Like Peptide 1; Humans; Insulin; Islets of Langerhans; Male; Middle Aged; Peptide Fragments; Pilot Projects; Protein Precursors | 2002 |
Glucagon-like peptide 1 increases secretory burst mass of pulsatile insulin secretion in patients with type 2 diabetes and impaired glucose tolerance.
The insulinotropic gut hormone glucagon-like peptide (GLP)-1 increases secretory burst mass and the amplitude of pulsatile insulin secretion in healthy volunteers without affecting burst frequency. Effects of GLP-1 on secretory mechanisms in type 2 diabetic patients and subjects with impaired glucose tolerance (IGT) known to have impaired pulsatile release of insulin have not yet been studied. Eight type 2 diabetic patients (64+/-9 years, BMI 28.9+/-7.2 kg/m2, HbA1c 7.7+/-1.3%) and eight subjects with IGT (63+/-10 years, BMI 31.7+/-6.4 kg/m2, HbA1c 5.7+/-0.4) were studied on separate occasions in the fasting state during the continued administration of exogenous GLP-1 (1.2 pmol x kg(-1) x min(-1), started at 10:00 P.M. the evening before) or placebo. For comparison, eight healthy volunteers (62+/-7 years, BMI 27.7+/-4.8 kg/m2, HbA1c 5.4+/-0.5) were studied only with placebo. Blood was sampled continuously over 60 min (roller-pump) in 1-min fractions for the measurement of plasma glucose and insulin. Pulsatile insulin secretion was characterized by deconvolution, autocorrelation, and spectral analysis and by estimating the degree of randomness (approximate entropy). In type 2 diabetic patients, exogenous GLP-1 at approximately 90 pmol/l improved plasma glucose concentrations (6.4+/-2.1 mmol/l vs. placebo 9.8+/-4.1 mmol/l, P = 0.0005) and significantly increased mean insulin burst mass (by 68%, P = 0.007) and amplitude (by 59%, P = 0.006; deconvolution analysis). In IGT subjects, burst mass was increased by 45% (P = 0.019) and amplitude by 38% (P = 0.02). By deconvolution analysis, insulin secretory burst frequency was not affected by GLP-1 in either type 2 diabetic patients (P = 0.15) or IGT subjects (P = 0.76). However, by both autocorrelation and spectral analysis, GLP-1 prolonged the period (lag time) between subsequent maxima of insulin concentrations significantly from approximately 9 to approximately 13 min in both type 2 diabetic patients and IGT subjects. Under placebo conditions, parameters of pulsatile insulin secretion were similar in normal subjects, type 2 diabetic patients, and IGT subjects based on all methodological approaches (P > 0.05). In conclusion, intravenous GLP-1 reduces plasma glucose in type 2 diabetic patients and improves the oscillatory secretion pattern by amplifying insulin secretory burst mass, whereas the oscillatory period determined by autocorrelation and spectral analysis is significantly prolonged. This was not the case Topics: Aged; Aged, 80 and over; Blood Glucose; Diabetes Mellitus, Type 2; Entropy; Female; Glucagon; Glucagon-Like Peptide 1; Glucose Intolerance; Hormones; Humans; Injections, Intravenous; Insulin; Insulin Secretion; Male; Middle Aged; Osmolar Concentration; Peptide Fragments; Protein Precursors; Pulsatile Flow; Reference Values | 2001 |
Additive glucose-lowering effects of glucagon-like peptide-1 and metformin in type 2 diabetes.
The incretin hormone glucagon-like peptide-1 (GLP-1) reduces plasma glucose in type 2 diabetic patients by stimulating insulin secretion and inhibiting glucagon secretion. The biguanide metformin is believed to lower plasma glucose without affecting insulin secretion. We conducted this study to investigate the effect of a combination therapy with GLP-1 and metformin, which could theoretically be additive, in type 2 diabetic patients.. In a semiblinded randomized crossover study, seven patients received treatment with metformin (1,500 mg daily orally) alternating with GLP-1 (continuous subcutaneous infusion of 2.4 pmol x kg(-1) x min(-1)) alternating with a combination of metformin and GLP-1 for 48 h. Under fixed energy intake, we examined the effects on plasma glucose, insulin, C-peptide, glucagon, and appetite.. Fasting plasma glucose (day 2) decreased from 13.9 +/- 1 (no treatment) to 11.2 +/- 0.4 (metformin) and 11.5 +/- 0.5 (GLP-1) and further decreased to 9.4 +/- 0.7 (combination therapy) (P = 0.0005, no difference between monotherapy with GLP-1 and metformin). The 24-h mean plasma glucose (day 2) decreased from 11.8 +/- 0.5 (metformin) and 11.7 +/- 0.8 (GLP-1) to 9.8 +/- 0.5 (combination) (P = 0.02, no difference between GLP-1 and metformin). Insulin levels were similar between the three regimens, but glucagon levels were significantly reduced with GLP-1 compared with metformin (P = 0.0003). Combination therapy had no additional effect on appetite scores.. Monotherapy with GLP-1 and metformin have equal effects on plasma glucose and additive effects upon combination. Topics: Blood Glucose; C-Peptide; Cross-Over Studies; Diabetes Mellitus, Type 2; Drug Administration Schedule; Drug Therapy, Combination; Female; Gastrointestinal Hormones; Glucagon; Glucagon-Like Peptide 1; Glucagon-Like Peptides; Glycated Hemoglobin; Humans; Infusions, Parenteral; Insulin; Insulin Secretion; Kinetics; Male; Metformin; Middle Aged; Peptide Fragments; Placebos; Research Design | 2001 |
Antidiabetogenic action of glucagon-like peptide-1 related to administration relative to meal intake in subjects with type 2 diabetes.
To establish the antidiabetogenic effect of glucagon-like peptide-1 (GLP-1) when differently administered relative to meal intake in subjects with type 2 diabetes.. The study was a placebo-controlled comparison with random assignment to treatment sequence. A 3-h stepwise infusion of GLP-1 (17 nmol) was started either at the onset of a standard meal (550 kCal) (A) or at 30 min (B) or 60 min (C) after the start of the meal.. The study was conducted at a university hospital.. Eight patients with type 2 diabetes (four women and four men), age 62 +/- 3.9 years (range 47-74 years), weight 79.8 +/- 5.4 kg (range 62-104 kg), BMI 26.2 +/- 1.3 kg m(-2) (range 21-31 kg m(-2)), diabetes duration 10.5 +/- 2.0 years (range 3-19 years) and HbA1c levels 6.1 +/- 0.3% (range 4.7-7.7%) participated in the study. All patients were treated with oral sulphonylureas.. Glucagon-like peptide-1 significantly lowered postprandial glycaemia by a similar degree in all three situations versus the control meal (P < 0.05). Postprandial insulin levels were not different in the four experimental series, whereas the postprandial glucagon levels were significantly lowered by GLP-1 in (A) and (B) (P < 0.03) but not in (C). Gastric emptying, as determined by the paracetamol test, was retarded by GLP-1 only in (A) (P < 0.01), but not affected in (B) or (C).. GLP-1 reduced postprandial hyperglycaemia in subjects with type 2 diabetes regardless of administration at the onset of meal intake or at 30 or 60 min after start of meal intake, although the mechanism of the antidiabetogenic action of GLP-1 depended on administration versus meal intake. Thus, when administered at the start of a meal, GLP-1 was antidiabetogenic mainly through retarding gastric emptying, whereas when given at 30 or 60 min after meal ingestion, changes in islet hormone secretion seem to be predominant. Topics: Aged; Blood Glucose; Diabetes Mellitus, Type 2; Drug Administration Schedule; Eating; Female; Gastric Emptying; Glucagon; Glucagon-Like Peptide 1; Humans; Hypoglycemic Agents; Insulin; Islets of Langerhans; Male; Middle Aged; Peptide Fragments; Protein Precursors; Time Factors | 2001 |
Glucagon-like peptide-1 infusion must be maintained for 24 h/day to obtain acceptable glycemia in type 2 diabetic patients who are poorly controlled on sulphonylurea treatment.
To assess the efficacy and safety of glucagon-like peptide-1 (GLP-1) on the plasma glucose level when given as a continuous infusion for either 16 or 24 h per day to type 2 diabetic patients who were poorly controlled on sulfonylurea treatment.. This single-center, randomized, parallel, double-blind, placebo-controlled trial was conducted in 40 hospitalized patients who were randomized to receive infusions of either placebo or GLP-1 4 or 8 ng. kg(-1). min(-1) for either 16 or 24 h per day for 7 days. At predetermined intervals, 24-h profiles of glucose, glucagon, and insulin were measured. Adverse events and clinical chemistry and hematology were recorded.. For all active treatment groups, the change in average glucose (area under the curve [AUC] for day 7 minus AUC for day 0 divided by 24 h) was statistically significantly different from placebo (P < or = 0.001). The GLP-1 8 ng. kg(-1). min(-1) dose given for 24 h was more efficacious than any of the other doses (P < or = 0.05). Nocturnal and fasting plasma glucose levels at day 7 were greater in the 16-h groups compared with the 24-h groups (P < or = 0.05). Insulin AUC did not show any treatment effect for any of the treatment groups when change was assessed from day 0 to day 7. However, for the 16-h groups, the pattern of the insulin profiles changed; the insulin profiles were considerably higher during the initial 3-4 h after restart of the GLP-1 infusion on day 7, although there was a tendency for insulin levels to decrease during the afternoon and evening. Glucagon AUC decreased significantly for all active treatment groups compared with placebo. GLP-1 was generally well tolerated.. This study demonstrated that GLP-1 should be given continuously to obtain the most optimal glycemic control. Because of the short plasma half-life of native GLP-1, long-acting derivatives should be developed to make GLP-1 treatment clinically relevant. Topics: Adult; Aged; Area Under Curve; Blood Glucose; Circadian Rhythm; Diabetes Mellitus, Type 2; Double-Blind Method; Female; Glucagon; Glucagon-Like Peptide 1; Humans; Hypoglycemic Agents; Infusions, Intravenous; Inpatients; Insulin; Male; Middle Aged; Peptide Fragments; Placebos; Protein Precursors; Sulfonylurea Compounds; Time Factors | 2001 |
Glucagon-like peptide-1 (7-37) augments insulin-mediated glucose uptake in elderly patients with diabetes.
Glucagon-like peptide-1 (GLP-1) is an intestinal insulinotropic hormone that augments glucose-induced insulin secretion in patients with type 2 diabetes. It has also been proposed that a substantial component of the glucose-lowering effects of GLP-1 occurs because this hormone enhances insulin-mediated glucose disposal. However, interpretations of the studies have been controversial. This study determines the effect of GLP-1 on insulin-mediated glucose disposal in elderly patients with type 2 diabetes.. Studies were conducted on 8 elderly patients with type 2 diabetes (age range, 76 +/- 1 years; body mass index, 28 +/- 1 kg/m(2)). Each subject underwent two 180-minute euglycemic (insulin infusion rate, 40 mU/m(2)/min) insulin clamps in random order. Glucose production (Ra) and disposal (Rd) rates were measured using tritiated glucose methodology. In one study, glucose and insulin alone were infused. In the other study, a primed-continuous infusion of GLP-1 was administered at a final rate of 1.5 pmol x kg(-1) x min(-1) from 30 to 180 minutes.. Glucose values were similar between the control and GLP-1 infusion studies. 120- to 180-minute insulin values appeared to be higher during the GLP-1 infusion study (control, 795 +/- 63 pmol/l; GLP-1, 1140 +/- 275 pmol/l; p = not significant [NS]). The higher insulin values were largely due to 2 subjects who had substantial insulin responses to GLP-1 despite euglycemia and hyperinsulinemia. The 120- to 180-minute insulin values were similar in the other 6 subjects (control, 746 +/- 35 pmol/l; GLP-1, 781 +/- 41 pmol/l; p = NS). Basal (control, 2.08 +/- 0.05 mg/kg/min; GLP-1, 2.13 +/- 0.04 mg/kg/min; p = NS) and 120- to 180-minute (control, 0.50 +/- 0.18 mg/kg/min; GLP-1, 0.45 +/- 0.14 mg/kg/min; p = NS) Ra was similar between studies. The 120- to 180-minute Rd values were higher during the GLP-1 infusion studies (control, 4.73 +/- 0.39 mg/kg/min; GLP-1, 5.52 +/- 0.43 mg/kg/min; p <.01). When the 2 subjects who had significant insulin responses to GLP-1 during the euglycemic clamp were excluded, the 120- to 180-minute Rd values were still higher in the GLP-1 infusion study (control, 5.22 +/- 0.32 mg/kg/min; GLP-1, 6.05 +/- 0.37 mg/kg/min; p <.05).. We conclude that GLP-1 may enhance insulin sensitivity in elderly patients with diabetes. Topics: Aged; Biological Transport, Active; Blood Glucose; C-Peptide; Diabetes Mellitus, Type 2; Glucagon; Glucagon-Like Peptide 1; Glucagon-Like Peptides; Glucose; Glucose Clamp Technique; Humans; Insulin; Peptide Fragments; Peptides | 2001 |
Antidiabetogenic action of cholecystokinin-8 in type 2 diabetes.
Cholecystokinin (CCK) is a gut hormone and a neuropeptide that has the capacity to stimulate insulin secretion. As insulin secretion is impaired in type 2 diabetes, we explored whether exogenous administration of this peptide exerts antidiabetogenic action. The C-terminal octapeptide of CCK (CCK-8) was therefore infused i.v. (24 pmol/kg x h) for 90 min in six healthy postmenopausal women and in six postmenopausal women with type 2 diabetes. At 15 min after start of infusion, a meal was served and ingested during 10 min. On a separate day, saline was infused instead of CCK-8. In both healthy subjects and subjects with type 2 diabetes, CCK-8 reduced the increase in circulating glucose after meal ingestion and potentiated the increase in circulating insulin. The ratio between the area under the curves for serum insulin and plasma glucose during the 15- to 75-min period after meal ingestion was increased by CCK-8 by 198 +/- 18% in healthy subjects (P = 0.002) and by 474 +/- 151% (P = 0.038) in subjects with type 2 diabetes. In contrast, the increase in the circulating levels of gastric inhibitory polypeptide (GIP), glucagon-like peptide-1 (GLP-1), or glucagon after meal ingestion was not significantly affected by CCK-8. The study therefore shows that CCK-8 exerts an antidiabetogenic action in both healthy subjects and type 2 diabetes through an insulinotropic action that most likely is exerted trough a direct islet effect. As at the same time, CCK-8 was infused without any adverse effects, the study suggests that CCK is a potential treatment for type 2 diabetes. Topics: Aged; Area Under Curve; Blood Glucose; Diabetes Mellitus, Type 2; Female; Gastric Inhibitory Polypeptide; Glucagon; Glucagon-Like Peptide 1; Humans; Hypoglycemic Agents; Injections, Intravenous; Insulin; Pancreas; Peptide Fragments; Postprandial Period; Protein Precursors; Sincalide | 2000 |
A novel hyperglycaemic clamp for characterization of islet function in humans: assessment of three different secretagogues, maximal insulin response and reproducibility.
Characterization of beta-cell function in humans is essential for identifying genetic defects involved in abnormal insulin secretion and the pathogenesis of type 2 diabetes.. We designed a novel test assessing plasma insulin and C-peptide in response to 3 different secretagogues. Seven lean, healthy volunteers twice underwent a 200 min hyperglycaemic clamp (10 mmol L-1) with administration of GLP-1 (1.5 pmol. kg-1. min-1) starting at 120 min and an arginine bolus at 180 min. We determined glucose-induced first and second-phase insulin secretion, GLP-1-stimulated insulin secretion, arginine-stimulated insulin response (increase above prestimulus, DeltaIarg) and the maximal, i. e. highest absolute, insulin concentration (Imax). Insulin sensitivity was assessed during second-phase hyperglycaemia. On a third occasion 6 subjects additionally received an arginine bolus at > 25 mM blood glucose, a test hitherto claimed to provoke maximal insulin secretion.. Insulin levels increased from 46 +/- 11 pM to 566 +/- 202 pM at 120 min, to 5104 +/- 1179 pM at 180 min and to maximally 8361 +/- 1368 pM after arginine (all P < 0.001). The within subject coefficients of variation of the different secretion parameters ranged from 10 +/- 3% to 16 +/- 6%. Except for second-phase which failed to correlate significantly with DeltaIarg (r = 0.52, P = 0.23) and Imax (r = 0.75, P = 0.053) all phases of insulin secretion correlated with one another. The insulin concentration after the arginine bolus at > 25 mM glucose (n = 6) was 2773 +/- 855 pM vs. 7562 +/- 1168 pM for Imax (P = 0.003).. This novel insulin secretion test elicits a distinct pattern of plasma insulin concentrations in response to the secretagogues glucose, GLP-1 and arginine and is highly reproducible and can be used for differential characterization of islet function. Topics: Adult; Arginine; Blood Glucose; C-Peptide; Diabetes Mellitus, Type 2; Female; Glucagon; Glucagon-Like Peptide 1; Glucagon-Like Peptides; Glucose; Glucose Clamp Technique; Humans; Hyperglycemia; Insulin; Insulin Resistance; Insulin Secretion; Islets of Langerhans; Male; Peptide Fragments; Protein Precursors; Reproducibility of Results | 2000 |
Short-term treatment with GLP-1 increases pulsatile insulin secretion in Type II diabetes with no effect on orderliness.
The enteric incretin hormone, glucagon-like peptide-1 (GLP-1), is a potent insulin secretagogue in healthy humans and patients with Type II (non-insulin-dependent) diabetes mellitus. In this study we assessed the impact of short-term GLP-1 infusion on pulsatile insulin secretion in Type II diabetic patients.. Type II diabetic patients (n = 8) were studied in a randomised cross-over design. Plasma insulin concentration time series were obtained during basal conditions and during infusion with saline or GLP-1 (1.2 pmol/l x kg(-1) x min(-1)) on 2 separate days. Plasma glucose was clamped at the initial concentration by a variable glucose infusion. Serum insulin concentration time series were evaluated by deconvolution analysis, autocorrelation analysis, spectral analysis and approximate entropy.. Serum insulin concentrations increased by approximately 100% during GLP-1 infusion. Pulsatile insulin secretion was increased as measured by secretory burst mass (19.3 +/- 3.8 vs 53.0 +/- 10.7 pmol/l/ pulse, p = 0.02) and secretory burst amplitude (7.7 +/- 1.5 vs 21.1 +/- 4.3 pmol/l/min, p = 0.02). A similar increase in basal insulin secretion was observed (3.6 +/- 0.9 vs 10.2 +/- 2.2 pmol/l/min, p = 0.004) with no changes in the fraction of insulin delivered in pulses (0.50 +/- 0.06 vs 0.49 +/- 0.02, p = 0.84). Regularity of secretion was unchanged as measured by spectral analysis (normalised spectral power: 5.9 +/- 0.6 vs 6.3 +/- 0.8, p = 0.86), autocorrelation analysis (autocorrelation coefficient: 0.19 +/- 0.04 vs 0.18 +/- 0.05, p = 0.66) and the approximate entropy statistic (1.48 +/- 0.02 vs 1.51 +/- 0.02, p = 0.86).. Short-term stimulation with GLP-1 jointly increases pulsatile and basal insulin secretion, maintaining but not improving system regularity in Type II diabetic patients. Topics: Blood Glucose; C-Peptide; Cross-Over Studies; Diabetes Mellitus, Type 2; Glucagon; Glucagon-Like Peptide 1; Humans; Insulin; Insulin Secretion; Middle Aged; Peptide Fragments; Periodicity; Protein Precursors | 2000 |
Effect of glucagon-like peptide 1(7-36) amide on glucose effectiveness and insulin action in people with type 2 diabetes.
Although it is well established that glucagon-like peptide 1(7-36) amide (GLP-1) is a potent stimulator of insulin secretion, its effects on insulin action and glucose effectiveness are less clear. To determine whether GLP-1 increases insulin action and glucose effectiveness, subjects with type 2 diabetes were studied on two occasions. Insulin was infused during the night on both occasions to ensure that baseline glucose concentrations were comparable. On the morning of study, either GLP-1 (1.2 pmol x kg(-1) x min(-1)) or saline were infused along with somatostatin and replacement amounts of glucagon. Glucose also was infused in a pattern mimicking that typically observed after a carbohydrate meal. Insulin concentrations were either kept constant at basal levels (n = 6) or varied so as to create a prandial insulin profile (n = 6). The increase in glucose concentration was virtually identical on the GLP-1 and saline study days during both the basal (1.21 +/- 0.15 vs. 1.32 +/- 0.19 mol/l per 6 h) and prandial (0.56 +/- 0.14 vs. 0.56 +/- 0.10 mol/l per 6 h) insulin infusions. During both the basal and prandial insulin infusions, glucose disappearance promptly increased after initiation of the glucose infusion to rates that did not differ on the GLP-1 and saline study days. Suppression of endogenous glucose production also was comparable on the GLP-1 and saline study days during both the basal (-2.7 +/- 0.3 vs. -3.1 +/- 0.2 micromol/kg) and prandial (-3.1 +/- 0.4 vs. -3.0 +/- 0.6 pmol/kg) insulin infusions. We conclude that when insulin and glucagon concentrations are matched, GLP-1 has negligible effects on either insulin action or glucose effectiveness in people with type 2 diabetes. These data strongly support the concept that GLP-1 improves glycemic control in people with type 2 diabetes by increasing insulin secretion, by inhibiting glucagon secretion, and by delaying gastric emptying rather than by altering extrapancreatic glucose metabolism. Topics: Blood Glucose; C-Peptide; Diabetes Mellitus, Type 2; Food; Gastric Emptying; Glucagon; Glucagon-Like Peptide 1; Glucagon-Like Peptides; Human Growth Hormone; Humans; Hydrocortisone; Insulin; Kinetics; Peptide Fragments; Somatostatin | 2000 |
Diet-induced change in fatty acid composition of plasma triacylglycerols is not associated with change in glucagon-like peptide 1 or insulin sensitivity in people with type 2 diabetes.
Polyunsaturated fatty acids (PUFAs) and monounsaturated fatty acids (MUFAs) have been shown to positively affect blood lipids; however, their comparative effects on insulin sensitivity are unclear.. Our objective was to investigate whether chronic intake of MUFAs or PUFAs improves insulin sensitivity in people with type 2 diabetes via stimulation of the endogenous gut hormone glucagon-like peptide 1 [7-36] amide (GLP-1).. Nine overweight people with type 2 diabetes received isoenergetic high-MUFA (20.3 +/- 3.5% of total energy) or high-PUFA (13.4 +/- 1. 3%) diets for 24 d in a randomized, double-blind crossover design.. Weight and glycemic control remained stable throughout the study. Despite a significant change in the plasma triacylglycerol linoleic-oleic acid ratio (L:O) with both diets (MUFA: from 0.46 +/- 0.03 to 0.29 +/- 0.02, P: < 0.005; PUFA: from 0.36 +/- 0.04 to 0.56 +/- 0.05, P: < 0.05) and the phospholipid L:O (1.7 +/- 0.1 to 2.0 +/- 0.3; P: = 0.04) during consumption of the PUFA diet, this change was not associated with a change in insulin sensitivity, measured by the short-insulin-tolerance test. There was a significant reduction in the ratio of total to HDL cholesterol during consumption of the PUFA diet (5.2 +/- 0.4 compared with 4.7 +/- 0.3; P: = 0.005) but no change with the MUFA diet. There was no change in the fasting or postprandial incremental area under the curve in response to an identical standard test meal for glucose, insulin, triacylglycerol, nonesterified fatty acids, or GLP-1.. Over the 3-wk intervention period, diet-induced change in the triacylglycerol or phospholipid L:O was not associated with either increased stimulation of GLP-1 or a change in insulin sensitivity in people with type 2 diabetes. Topics: Blood Glucose; Cross-Over Studies; Diabetes Mellitus, Type 2; Dietary Fats, Unsaturated; Double-Blind Method; Fatty Acids; Fatty Acids, Monounsaturated; Fatty Acids, Nonesterified; Fatty Acids, Unsaturated; Glucagon; Glucagon-Like Peptide 1; Humans; Insulin; Linoleic Acid; Oleic Acid; Peptide Fragments; Protein Precursors; Triglycerides | 2000 |
Effect of nutrient ingestion on glucagon-like peptide 1 (7-36 amide) secretion in human type 1 and type 2 diabetes.
Exogenous glucagon-like peptide 1(GLP-1) bioactivity is preserved in type 2 diabetic patients, resulting the peptide administration in a near-normalization of plasma glucose mainly through its insulinotropic effect. GLP-1 also reduces meal-related insulin requirement in type 1 diabetic patients, suggesting an impairment of the entero-insular axis in both diabetic conditions. To investigate this metabolic dysfunction, we evaluated endogenous GLP-1 concentrations, both at fasting and in response to nutrient ingestion, in 16 type 1 diabetic patients (age = 40.5 +/- 14yr, HbA1C = 7.8 +/- 1.5%), 14 type 2 diabetics (age = 56.5 +/- 13yr, HbA1C = 8.1 +/- 1.8%), and 10 matched controls. In postabsorptive state, a mixed breakfast (230 KCal) was administered to all subjects and blood samples were collected for plasma glucose, insulin, C-peptide and GLP-1 determination during the following 3 hours. In normal subjects, the test meal induced a significant increase of GLP-1 (30', 60': p < 0.01), returning the peptide values towards basal concentrations. In type 2 diabetic patients, fasting plasma GLP-1 was similar to controls (102.1 +/- 1.9 vs. 97.3 +/- 4.01 pg/ml), but nutrient ingestion failed to increase plasma peptide levels, which even decreased during the test (p < 0.01). Similarly, no increase in postprandial GLP-1 occurred in type 1 diabetics, in spite of maintained basal peptide secretion (106.5 +/- 1.5 pg/ml). With respect to controls, the test meal induced in both diabetic groups a significant increase in plasma glucagon levels at 60' (p < 0.01). In conclusion, either in condition of insulin resistance or insulin deficiency chronic hyperglycemia, which is a common feature of both metabolic disorders, could induce a progressive desensitization of intestinal L-cells with consequent peptide failure response to specific stimulation. Topics: Adult; Blood Glucose; Diabetes Mellitus, Type 1; Diabetes Mellitus, Type 2; Eating; Female; Gastrointestinal Hormones; Glucagon; Glucagon-Like Peptide 1; Glucagon-Like Peptides; Humans; Insulin; Male; Middle Aged; Peptide Fragments; Radioimmunoassay | 2000 |
Glucagon-like peptide-1 promotes satiety and reduces food intake in patients with diabetes mellitus type 2.
Glucagon-like peptide-1-(7-36) amide (GLP-1) is an incretin hormone of the enteroinsular axis. Recent experimental evidence in animals and healthy subjects suggests that GLP-1 has a role in controlling appetite and energy intake in humans. We have therefore examined in a double-blind, placebo-controlled, crossover study in 12 patients with diabetes type 2 the effect of intravenously infused GLP-1 on appetite sensations and energy intake. On 2 days, either saline or GLP-1 (1.5 pmol. kg-1. min-1) was given throughout the experiment. Visual analog scales were used to assess appetite sensations; furthermore, food and fluid intake of a test meal were recorded, and blood was sampled for analysis of plasma glucose and hormone levels. GLP-1 infusion enhanced satiety and fullness compared with placebo (P = 0.028 for fullness and P = 0.026 for hunger feelings). Energy intake was reduced by 27% by GLP-1 (P = 0.034) compared with saline. The results demonstrate a marked effect of GLP-1 on appetite by showing enhanced satiety and reduced energy intake in patients with diabetes type 2. Topics: Appetite; Blood Glucose; Brain Chemistry; Cross-Over Studies; Diabetes Mellitus, Type 2; Double-Blind Method; Eating; Glucagon; Glucagon-Like Peptide 1; Humans; Hyperglycemia; Infusions, Intravenous; Insulin; Male; Middle Aged; Obesity; Peptide Fragments; Protein Precursors; Satiation | 1999 |
Continuous subcutaneous infusion of glucagon-like peptide 1 lowers plasma glucose and reduces appetite in type 2 diabetic patients.
The gut hormone glucagon-like peptide 1 (GLP-1) has insulinotropic and anorectic effects during intravenous infusion and has been proposed as a new treatment for type 2 diabetes and obesity. The effect of a single subcutaneous injection is brief because of rapid degradation. We therefore sought to evaluate the effect of infusion of GLP-1 for 48 h in patients with type 2 diabetes.. We infused GLP-1 (2.4 pmol.kg-1.min-1) or saline subcutaneously for 48 h in randomized order in six patients with type 2 diabetes to evaluate the effect on appetite during fixed energy intake and on plasma glucose, insulin, glucagon, postprandial lipidemia, blood pressure, heart rate, and basal metabolic rate.. The infusion resulted in elevations of the plasma concentrations of intact GLP-1 similar to those observed after intravenous infusion of 1.2 pmol.kg-1.min-1, previously shown to lower blood glucose effectively in type 2 diabetic patients. Fasting plasma glucose (day 2) decreased from 14.1 +/- 0.9 (saline) to 12.2 +/- 0.7 mmol/l (GLP-1), P = 0.009, and 24-h mean plasma glucose decreased from 15.4 +/- 1.0 to 13.0 +/- 1.0 mmol/l, P = 0.0009. Fasting and total area under the curve for insulin and C-peptide levels were significantly higher during the GLP-1 administration, whereas glucagon levels were unchanged. Neither triglycerides nor free fatty acids were affected. GLP-1 administration decreased hunger and prospective food intake and increased satiety, whereas fullness was unaffected. No side effects during GLP-1 infusion were recorded except for a brief cutaneous reaction. Basal metabolic rate and heart rate did not change significantly during GLP-1 administration. Both systolic and diastolic blood pressure tended to be lower during the GLP-1 infusion.. We conclude that 48-h continuous subcutaneous infusion of GLP-1 in type 2 diabetic patients 1) lowers fasting as well as meal-related plasma glucose, 2) reduces appetite, 3) has no gastrointestinal side effects, and 4) has no negative effect on blood pressure. Topics: Adult; Aged; Appetite; Appetite Depressants; Blood Glucose; Blood Pressure; C-Peptide; Diabetes Mellitus, Type 2; Drug Delivery Systems; Energy Intake; Glucagon; Glucagon-Like Peptide 1; Glucagon-Like Peptides; Humans; Hypoglycemic Agents; Infusion Pumps; Insulin; Lipids; Middle Aged; Peptide Fragments; Peptides; Pilot Projects; Postprandial Period; Protein Precursors | 1999 |
Mechanisms of the antidiabetic action of subcutaneous glucagon-like peptide-1(7-36)amide in non-insulin dependent diabetes mellitus.
Twelve patients with non-insulin dependent diabetes mellitus (NIDDM) under secondary failure to sulfonylureas were studied to evaluate the effects of subcutaneous glucagon-like peptide-1(7-36)amide (GLP-1) on (a) the gastric emptying pattern of a solid meal (250 kcal) and (b) the glycemic and endocrine responses to this solid meal and an oral glucose tolerance test (OGTT, 300 kcal). 0.5 nmol/kg of GLP-1 or placebo were subcutaneously injected 20 min after meal ingestion. GLP-1 modified the pattern of gastric emptying by prolonging the time to reach maximal emptying velocity (lag period) which was followed by an acceleration in the post-lag period. The maximal emptying velocity and the emptying half-time remained unaltered. With both meals, GLP-1 diminished the postprandial glucose peak, and reduced the glycemic response during the first two postprandial hours by 54.5% (solid meal) and 32.7% (OGTT) (P < 0.05). GLP-1 markedly stimulated insulin secretion with an effect lasting for 105 min (solid meal) or 150 min (OGTT). The postprandial increase of plasma glucagon was abolished by GLP-1. GLP-1 diminished the postprandial release of pancreatic polypeptide. The initial and transient delay of gastric emptying, the enhancement of postprandial insulin release, and the inhibition of postprandial glucagon release were independent determinants (P < 0.002) of the postprandial glucose response after subcutaneous GLP-1. An inhibition of efferent vagal activity may contribute to the inhibitory effect of GLP-1 on gastric emptying. Topics: Aged; Blood Glucose; Breath Tests; Diabetes Mellitus, Type 2; Female; Gastric Emptying; Glucagon; Glucagon-Like Peptide 1; Glucagon-Like Peptides; Glucose Tolerance Test; Humans; Injections, Subcutaneous; Insulin; Male; Middle Aged; Neurotransmitter Agents; Pancreatic Polypeptide; Peptide Fragments; Postprandial Period; Regression Analysis | 1998 |
Overnight GLP-1 normalizes fasting but not daytime plasma glucose levels in NIDDM patients.
GLP-1 (7-36 amide) normalizes fasting plasma glucose in NIDDM patients. It was the aim to study the effect of overnight intravenous GLP-1 (7-36 amide) on the following 24 h-glucose profiles. Ten NIDDM patients (7 female, 3 male; age 62 +/- 4 y., BMI (Body-Mass-Index) 29.6 +/- 3.9 kg/m2, duration 10 +/- 7 y., HbA1c 10.9 +/- 1.3% (normal 4.0-6.1%), treated with glibenclamide and/or metformin) were studied on two occasions in random order: Either GLP-1 (7-36 amide) (Saxon Biochemicals, Hannover, FRG, 1 pmol x kg(-1) x min(-1)) or placebo (0.9% NaCl with 1% human serum albumin, Behringwerke, Marburg, FRG) were infused intravenously from 22:00 to 7:00 (9 h) and plasma glucose profiles were obtained during the GLP-1 infusion and the following 24 hours. GLP-1 (7-36 amide) (plasma concentration 110 +/- 12 pmol/l) raised plasma C-peptide concentrations (p = 0.0005), suppressed glucagon (p = 0.01) and lowered plasma glucose to 5.5 +/- 0.6 and 6.3 +/- 0.4 mmol/l at 3:00 and 7:00 a.m. (vs. 10.3 +/- 0.9 and 11.3 +/- 0.6 mmol/l, p = 0.0003 and p < 0.0001, respectively, with placebo). Thereafter, starting 1 h after breakfast, no significant differences in plasma glucose, insulin, C-peptide or glucagon profiles were found between experiments with GLP-1 (7-36 amide) and placebo. Average plasma glucose concentrations over the whole 24 h period were reduced by 18% by GLP-1 administered overnight. In conclusion, (1) overnight GLP-1 (7-36 amide) normalizes fasting plasma glucose, but (2) has no sustained effect on meal-induced glucose, insulin or glucagon concentrations once its administration has been stopped. (3) Normalization of fasting plasma glucose alone does not improve daytime metabolic control in NIDDM patients on oral agents. Topics: Aged; Blood Glucose; C-Peptide; Diabetes Mellitus, Type 2; Drug Administration Schedule; Fasting; Female; Glucagon; Glucagon-Like Peptide 1; Humans; Insulin; Insulin Secretion; Male; Middle Aged; Peptide Fragments; Postprandial Period; Protein Precursors; Single-Blind Method; Time Factors; Treatment Outcome | 1998 |
Prolonged and enhanced secretion of glucagon-like peptide 1 (7-36 amide) after oral sucrose due to alpha-glucosidase inhibition (acarbose) in Type 2 diabetic patients.
GLP-1, an incretin hormone of the enteroinsular axis with insulinotropic and glucagonostatic activity, is secreted after nutrient ingestion. GLP-1 is mainly produced by intestinal L-cells in the lower gastrointestinal tract (GIT); simple carbohydrates are absorbed in the upper GIT and alpha-glucosidase inhibition leads to augmented and prolonged GLP-1 release in normal subjects. In a cross-over study, 100 mg acarbose or placebo was administered simultaneously with 100 g sucrose to 11 hyperglycaemic Type 2 diabetic patients poorly controlled with diet and sulphonylureas. Plasma levels of GLP-1, insulin, C-peptide, glugacon, GIP, glucose and H2-exhalation were measured over 6 h. Differences in the integrated responses over the observation period were evaluated by repeated measurement analysis of variance with fasting values used as covariates. With acarbose, sucrose reached the colon 60-90 min after ingestion as indicated by a significant increment in breath hydrogen exhalation (p = 0.005). After an early GLP-1 increment 15 min after sucrose under both conditions, GLP-1 release was prolonged in the acarbose group (p = 0.001; significant from 210 to 360 min.). Initially (0-150 min), glucose (p = 0.001), insulin (p = 0.001), and GIP (p < 0.001) were suppressed by acarbose, whereas later there were no significant differences. Glucagon levels were higher with acarbose in the last 3 h of the 6 h observation period (p = 0.02). We conclude that in hyperglycaemic Type 2 diabetic patients, ingestion of acarbose with a sucrose load leads to elevated and prolonged GLP-1 release. Topics: Acarbose; Administration, Oral; Aged; Blood Glucose; C-Peptide; Diabetes Mellitus, Type 2; Enzyme Inhibitors; Female; Gastric Inhibitory Polypeptide; Gastrointestinal Hormones; Glucagon; Glucagon-Like Peptide 1; Glucagon-Like Peptides; Glycoside Hydrolase Inhibitors; Humans; Hypoglycemic Agents; Insulin; Male; Middle Aged; Peptide Fragments; Sucrose; Time Factors; Trisaccharides | 1998 |
Subcutaneous glucagon-like peptide-1 improves postprandial glycaemic control over a 3-week period in patients with early type 2 diabetes.
1.Glucagon-like peptide-1 (7-36) amide (GLP-1) is released into the circulation after meals and is the most potent physiological insulinotropic hormone in man. GLP-1 has the advantages over other therapeutic agents for Type 2 diabetes of also suppressing glucagon secretion and delaying gastric emptying. One of the initial abnormalities of Type 2 diabetes is the loss of the first-phase insulin response, leading to postprandial hyperglycaemia.2. To investigate the therapeutic potential of GLP-1 in Type 2 diabetes, six patients were entered into a 6-week, double-blind crossover trial during which each received 3 weeks treatment with subcutaneous GLP-1 or saline, self-administered three times a day immediately before meals. A standard test meal was given at the beginning and end of each treatment period.3.GLP-1 reduced plasma glucose area under the curve (AUC) after the standard test meal by 58% (AUC, 0-240 min: GLP-1 start of treatment, 196+/-141 mmol.min-1.l-1; saline start of treatment, 469+/-124 mmol.min-1.l-1; F=16.4, P<0.05). The plasma insulin excursions were significantly higher with GLP-1 compared with saline over the initial postprandial 30 min, the time period during which the GLP-1 concentration was considerably elevated. The plasma glucagon levels were significantly lower over the 240-min postprandial period with GLP-1 treatment. The beneficial effects of GLP-1 on plasma glucose, insulin and glucagon concentrations were fully maintained for the 3-week treatment period. 4. We have demonstrated a significant improvement in postprandial glycaemic control with subcutaneous GLP-1 treatment. GLP-1 improves glycaemic control partially by restoring the first-phase insulin response and suppressing glucagon and is a potential treatment for Type 2 diabetes. Topics: Adult; Analysis of Variance; Area Under Curve; Blood Glucose; Cross-Over Studies; Diabetes Mellitus, Type 2; Double-Blind Method; Drug Administration Schedule; Female; Glucagon; Glucagon-Like Peptide 1; Humans; Hypoglycemic Agents; Injections, Subcutaneous; Insulin; Male; Peptide Fragments; Postprandial Period; Protein Precursors | 1998 |
Influence of glucagon-like peptide 1 on fasting glycemia in type 2 diabetic patients treated with insulin after sulfonylurea secondary failure.
Glucagon-like peptide 1 (GLP-1) has glucose-dependent insulinotropic and glucagonostatic actions in type 2 diabetic patients on diet and on oral agents. It is not known, however, whether after secondary sulfonylurea failure, GLP-1 is still effective.. Therefore, 10 type 2 diabetic patients (6 women, 4 men; age 65+/-10 years, BMI 30.4+/-5.1 kg/m2, HbA1c 8.2+/-1.5%, 6+/-3 [2-13] years after starting insulin treatment) were examined in the fasting state after discontinuing NPH insulin on the evening before the two study days. GLP-1 (1.2 pmol x kg(-1) x min(-1) or placebo (NaCl with 1% human serum albumin) were infused over 6 h. Plasma glucose (glucose oxidase) insulin (IMx), and C-peptide (enzyme-linked immunosorbent assay) were measured. Statistical analysis was performed using repeated measures analysis of variance.. Fasting plasma glucose was 9.4+/-0.5 mmol/l and was reduced by GLP-1 to 5.3+/-0.3 (3.9-7.3) mmol/l (placebo: 8.2+/-0.7 mmol/l; P < 0.0001). GLP-1 transiently increased insulin (from 115+/-31 to 222+/-64 pmol/l at 150 min; P < 0.0001) and C-peptide (from 1.00+/-0.12 to 1.90+/-0.23 nmol/l at 120 min; P < 0.0001) with no effect of placebo. Glucagon and free fatty acids were lowered transiently. After normalization of plasma glucose, insulin and C-peptide concentrations became lower again during the ongoing administration of exogenous GLP-1, and no hypoglycemia occurred.. It is concluded that exogenous GLP-1 effectively lowers plasma glucose concentrations in advanced type 2 diabetes long after sulfonylurea secondary failure. These findings may broaden the applicability of GLP-1-derived drugs as a new treatment to nearly all type 2 diabetic patients. Topics: Aged; Blood Glucose; C-Peptide; Calorimetry, Indirect; Cholesterol; Diabetes Mellitus, Type 2; Enzyme-Linked Immunosorbent Assay; Fasting; Fatty Acids, Nonesterified; Female; Glucagon; Glucagon-Like Peptide 1; Humans; Hypoglycemic Agents; Insulin; Male; Middle Aged; Peptide Fragments; Postprandial Period; Proinsulin; Protein Precursors; Sulfonylurea Compounds; Triglycerides | 1998 |
Normalization of fasting glycaemia by intravenous GLP-1 ([7-36 amide] or [7-37]) in type 2 diabetic patients.
Intravenous GLP-1 [7-36 amide] can normalize fasting hyperglycaemia in Type 2 diabetic patients. Whether GLP-1 [7-37] has similar effects and how quickly plasma glucose concentrations revert to hyperglycaemia after stopping GLP-1 is not known. Therefore, 8 patients with Type 2 diabetes (5 female, 3 male; 65+/-6 years; BMI 34.3+/-7.9 kg m(-2); HbA1c 9.6+/-1.2%; treatment with diet alone (n=2), sulphonylurea (n=5), metformin (n=1)) were examined twice in randomized order. GLP-1 [7-36 amide] or [7-37] (1 pmol kg(-1)min(-1) were infused intravenously over 4 h in fasted subjects. Plasma glucose (glucose-oxidase), insulin and C-peptide (ELISA) was measured during infusion and for 4 h thereafter. Indirect calorimetry was performed. Fasting hyperglycaemia was 11.7+/-0.9 [7-36 amide] and 11.3+/-0.9 mmol l(-1) [7-37]. GLP-1 infusions stimulated insulin secretion approximately 3-fold (insulin peak 168+/-32 and 156+/-47 pmol l(-1), p<0.0001 vs basal; C-peptide peak 2.32+/-0.28 and 2.34+/-0.43 nmol l(-1), p<0.0001, respectively, with GLP-1 [7-36 amide] and [7-37]). Four hours of GLP-1 infusion reduced plasma glucose (4.8+/-0.4 and 4.6+/-0.3 mmol l(-1), p<0.0001 vs basal values), and it remained in the non-diabetic fasting range after a further 4 h (5.1+/-0.4 and 5.3+/-0.4 mmol l(-1), for GLP [7-36 amide] and [7-37], respectively). There were no significant differences between GLP-1 [7-36 amide] and [7-37] (glucose, p=0.99; insulin, p=0.99; C-peptide, p=0.99). Neither glucose oxidation nor lipid oxidation (or any other parameters determined by indirect calorimetry) changed during or after the administration of exogenous GLP-1. In conclusion, GLP-1 [7-36 amide] and [7-37] normalize fasting hyperglycaemia in Type 2 diabetic patients. Diabetes therapy (diet, sulphonyl ureas or metformin) does not appear to influence this effect. In fasting and resting patients, the effect persists during administration of GLP-1 and for at least 4 h thereafter, without rebound. Significant changes in circulating substrate concentrations (e.g. glucose) are not accompanied by changes in intracellular substrate metabolism. Topics: Age of Onset; Aged; Blood Glucose; C-Peptide; Calorimetry, Indirect; Cholesterol; Diabetes Mellitus, Type 2; Fasting; Fatty Acids, Nonesterified; Female; Glucagon; Glucagon-Like Peptide 1; Glucagon-Like Peptides; Glycated Hemoglobin; Humans; Hypoglycemic Agents; Infusions, Intravenous; Insulin; Insulin Secretion; Male; Middle Aged; Peptide Fragments; Peptides; Triglycerides | 1998 |
Near-normalisation of diurnal glucose concentrations by continuous administration of glucagon-like peptide-1 (GLP-1) in subjects with NIDDM.
The gut hormone, glucagon-like peptide-1 (GLP-1) is a potent insulin secretogogue with potential as a therapy for non-insulin-dependent diabetes mellitus (NIDDM). GLP-1 has been shown to reduce glucose concentrations, both basally, and, independently, in response to a single meal. For it to be an effective treatment, it would need to be administered as a long-acting therapy, but this might not be feasible due to the profound delay in gastric emptying induced by GLP-1. In order to assess the feasibility and efficacy of continuous administration of GLP-1 in NIDDM, we determined the effects of continuous intravenous infusion of GLP-1 (7-36) amide, from 22.00-17.00 hours, on glucose and insulin concentrations overnight and in response to three standard meals, in eight subjects with NIDDM. These were compared with responses to 0.9% NaCl infusion and responses in six non-diabetic control subjects who were not receiving GLP-1. Effects of beta-cell function were assessed in the basal state using homeostasis model assessment (HOMA) and in the postprandial state by dividing incremental insulin responses to breakfast by incremental glucose responses. To assess possible clinical benefit from priming of beta cells by GLP-1 given overnight only, a third study assessed the effect of GLP-1 given from 22.00-07.30 hours on subsequent glucose responses the next day. Continuous GLP-1 infusion markedly reduced overnight glucose concentrations (mean from 24.00-08.00 hours) from median (range) 7.8 (6.1-13.8) to 5.1 (4.0-9.2) mmol/l (p < 0.02), not significantly different from control subjects, 5.6 (5.0-5.8) mmol/l. Daytime glucose concentrations (mean from 08.00-17.00 hours) were reduced from 11.0 (9.3-16.4) to 7.6 (4.9-11.5) mmol/l (p < 0.02), not significantly different from control subjects, 6.7 (6.5-7.0) mmol/l. GLP-1 improved beta-cell function in the basal state from 62 (13-102) to 116 (46-180) %beta (p < 0.02) and following breakfast from 57 (19-185) to 113 (31-494) pmol/mmol (p < 0.02). GLP-1 only given overnight did not improve the glucose responses to meals the next day. In conclusion, continuous infusion of GLP-1 markedly reduced diurnal glucose concentrations, suggesting that continuous GLP-1 administration may be as useful therapy in NIDDM. Topics: Adult; Aged; Blood Glucose; Circadian Rhythm; Diabetes Mellitus, Type 2; Female; Gastric Emptying; Glucagon; Glucagon-Like Peptide 1; Humans; Hypoglycemic Agents; Infusions, Intravenous; Islets of Langerhans; Male; Middle Aged; Peptide Fragments; Prospective Studies; Protein Precursors | 1997 |
No apparent benefit of liquid formula diet in NIDDM.
We have studied the impact of liquid diets formulated for complete or supplemental enteral nutrition of type II, non insulin-dependent (NIDDM) diabetics on carbohydrate homeostasis. To achieve this, liquid formula tolerance tests were performed in NIDDM patients under an oral treatment regimen with a combination of diet plus glibenclamide (7 men, 3 women, age: 56 +/- 11 years; mean body mass index of 26.2 +/- 3.6 kg/m2). After an overnight fast, each patient received the usual morning medication and, thereafter, ingested formula diet in randomized order with 10 day intervals between tests. 500 ml were administered of either a standard liquid diet (Biosorb Sonde), a fibre containing diet (Biosorb Plus Sonde), or a carbohydrate modified, fructose containing "diabetes" diet (Fresubin Diabetes) (carbohydrate contents of approximately equal to 60 g, respectively). Blood samples were collected over 180 min. Considering minor variations in the nutritional values of the diets, IR-insulin, IR-C-peptide, IR-glucose-dependent insulinotropic polypeptide (GIP), and IR-glucagon-like peptide. 1 (GLP-1) in plasma did not significantly differ between the study groups. After ingestion of Biosorb Sonde area under the curve glucose was greater than that seen after uptake of fibre containing or carbohydrate modified, i.e. fructose containing "liquid diabetes diets". All diets challenged the entero-insular axis in non-insulin dependent diabetics to a comparable extent. This data does not support the contention to employ special "diabetes" formulas for enteral nutrition of patients with NIDDM. Topics: Adult; Aged; Blood Glucose; C-Peptide; Diabetes Mellitus, Type 2; Enteral Nutrition; Female; Gastric Inhibitory Polypeptide; Glucagon-Like Peptide 1; Humans; Insulin; Insulin Secretion; Male; Middle Aged; Peptides; Postprandial Period | 1997 |
Glucagon-like peptide-1 (GLP-1): a trial of treatment in non-insulin-dependent diabetes mellitus.
Glucagon-like peptide-1 (7-36) amide (GLP-1) is released from the gut into the circulation after meals and is the most potent physiological insulinotropic hormone in man. In contrast to presently available therapeutic agents for non-insulin-dependent diabetes mellitus (NIDDM), GLP-1 has the advantages of both suppressing glucagon secretion and delaying gastric emptying. We report the first chronic study of subcutaneous (s/c) GLP-1 treatment in NIDDM. Five patients with poorly controlled NIDDM were entered into a six-week, double-blind crossover trial. Each received three weeks treatment with s/c GLP-1 40 nmol or saline, given three times a day immediately before meals. A standardized test meal was given at the beginning and end of each treatment period. GLP-1 reduced plasma glucose area under the curve (AUC) following the standard test meal by 25% (AUC, 0-180 mins, GLP-1 start of treatment 482.2 +/- 38.2 vs. saline start of treatment 635.7 +/- 45.4 mmol min L-1, F = 16.4, P < 0.02). The beneficial effect of GLP-1 on plasma glucose concentration was fully maintained for the three-week treatment period. Plasma glucagon levels were significantly lower for 60 min postprandially after GLP-1 treatment. In this group of patients there was no significant increase in postprandial insulin levels with GLP-1. We have demonstrated a significant improvement in postprandial glycaemic control with s/c GLP-1 treatment that was fully maintained over a three-week treatment period. GLP-1 improves glycaemic control even in the absence of an insulinotropic effect and is a potential treatment for NIDDM. Topics: Blood Glucose; Cross-Over Studies; Diabetes Mellitus, Type 2; Double-Blind Method; Female; Glucagon; Glucagon-Like Peptide 1; Humans; Injections, Subcutaneous; Insulin; Male; Middle Aged; Peptides | 1997 |
Glucagon-like peptide 1 and its potential in the treatment of non-insulin-dependent diabetes mellitus.
Studies examining small groups of type 2-(NIDDM) diabetic patients have shown the potential of glucagon-like peptide 1 (GLP-1) to normalize fasting hyperglycaemia. Patient characteristics determining the size of the effect have not been reported. Therefore, the results of four studies were analysed. Exogenous GLP-1 was administered i.v. or s.c. in 37 type 2-diabetic patients, age 60 +/- 8 years; BMI 28.2 +/- 5.3 kg/m2; HbA1c 10.6 +/- 1.6%; diabetes duration 10 +/- 6 years, treatment with sulfonylureas, n = 33, metformin, n = 11, acarbose, n = 3. Results were analysed using repeated measures analysis of variance and multiple regression analysis. Exogenous GLP-1 lowered fasting plasma glucose within 4-5 h from 12.8 +/- 2.5 to 5.3 +/- 1.3 mmol/l (placebo: 12.8 +/- 2.3 to 10.0 +/- 2.2; p < 0.0001 for the interaction of treatment and time). Only fasting glycaemia (p = 0.0085) and the route (i.v. vs. s.c.; p = 0.05), but not gender, age, BMI, HbA1c, diabetes duration, treatment with sulfonylureas, metformin or acarbose, were significant predictors of the plasma glucose concentrations reached after the administration of GLP-1 (variation: 3.4-8.5 mmol/l). In conclusion, GLP-1 is able to normalize plasma glucose in all type 2-diabetic patients studied. This analysis underlines the great therapeutic potential of GLP-1. Topics: Acarbose; Aged; Blood Glucose; Body Mass Index; Diabetes Mellitus, Type 2; Glucagon; Glucagon-Like Peptide 1; Glycated Hemoglobin; Humans; Metformin; Middle Aged; Peptide Fragments; Protein Precursors; Regression Analysis; Sulfonylurea Compounds; Trisaccharides | 1997 |
GLP-1 tablet in type 2 diabetes in fasting and postprandial conditions.
To examine the absorption of glucagon-like peptide (GLP)-1(7-36) amide from the buccal mucosa of type 2 diabetic patients. Previously, the effects of the peptide have been studied following intravenous and subcutaneous injection. Now, a mucoadhesive, biodegradable buccal GLP-1 tablet (9 mm) containing 119 nmol has been developed as a possible alternative to injection.. A total of 10 type 2 diabetic patients received a single tablet under fasting conditions and before a standard meal in this randomized placebo-controlled study.. The mean peak GLP-1 concentration was 125.1 pmol/l and occurred 30 min after application. The mean placebo-adjusted area under the curve was 5,334 min pmol/l, consistent with a relative bioavailability of 6% vs. intravenous injection and 42% vs. subcutaneous injection. The half-life of total peptide activity after buccal administration was 17 min. The placebo-adjusted glucose concentrations decreased by 1.4 mmol/l in fasting experiments and by 4.2 mmol/l after a standard mixed meal. In the fasting state at 30 min, plasma insulin increased by 185% and glucagon decreased by 20%, consistent with the increase in plasma GLP-1 concentrations. The peptide exerted a significant insulinotropic effect during meals (calculated as an insulinogenic index, 0-120 min; 84.1 vs. 45.7 in placebo experiments).. Potentially therapeutic plasma levels of GLP-1 were achieved after administration of a single buccal tablet in type 2 diabetic patients. The peptide had a marked glucose-lowering effect during the first 2 h. This new GLP-1 tablet may become a feasible alternative treatment for type 2 diabetic patients, although a more prolonged pharmacokinetic profile is required. Topics: Absorption; Administration, Buccal; Aged; Blood Glucose; Cross-Over Studies; Diabetes Mellitus, Type 2; Double-Blind Method; Fasting; Female; Glucagon; Glucagon-Like Peptide 1; Half-Life; Humans; Insulin; Male; Middle Aged; Peptide Fragments; Postprandial Period; Protein Precursors; Tablets | 1997 |
No correlation between insulin and islet amyloid polypeptide after stimulation with glucagon-like peptide-1 in type 2 diabetes.
To examine whether glucagon-like peptide-1 (GLP-1), which has been suggested as a new therapeutic agent in type 2 diabetes, affects circulating islet amyloid polypeptide (IAPP), a B-cell peptide of potential importance for diabetes pathophysiology.. GLP-1 was administered in a buccal tablet (400 micrograms) to seven healthy subjects and nine subjects with type 2 diabetes. Serum IAPP and insulin levels were measured before and after GLP-1 administration.. In the fasting state, serum IAPP was 4.1 +/- 0.3 pmol/l in the controls vs 9.8 +/- 0.9 pmol/l in the subjects with type 2 diabetes (P < 0.001). IAPP correlated with insulin only in controls (r = 0.74, P = 0.002) but not in type 2 diabetes (r = 0.26, NS). At 15 min after GLP-1, circulating IAPP increased to (6.0 +/- 0.5 pmol/l in controls P = 0.009) and to 13.8 +/- 1.2 pmol/l in type 2 diabetes (P = 0.021). In both groups, serum insulin increased and blood glucose decreased compared with placebo. In controls serum IAPP increased in parallel with insulin (r = 0.79, P = 0.032), whereas in type 2 diabetes the increase in IAPP did not correlate with the increase in insulin.. Type 2 diabetes is associated with elevated circulating IAPP; GLP-1stimulates IAPP secretion both in healthy human subjects and in type 2 diabetes; IAPP secretion correlates with insulin secretion only in healthy subjects and not in type 2 diabetes. Topics: Adult; Amyloid; Diabetes Mellitus, Type 2; Fasting; Female; Glucagon; Glucagon-Like Peptide 1; Humans; Insulin; Islet Amyloid Polypeptide; Male; Middle Aged; Peptide Fragments; Protein Precursors | 1997 |
Gastric emptying, glucose responses, and insulin secretion after a liquid test meal: effects of exogenous glucagon-like peptide-1 (GLP-1)-(7-36) amide in type 2 (noninsulin-dependent) diabetic patients.
The aim of the study was to investigate whether inhibition of gastric emptying of meals plays a role in the mechanism of the blood glucose-lowering action of glucagon-like peptide-1-(7-36) amide [GLP-1-(7-36) amide] in type 2 diabetes. Eight poorly controlled type 2 diabetic patients (age, 58 +/- 6 yr; body mass index, 30.0 +/- 5.2 kg/m2; hemoglobin A1c, 10.5 +/- 1.2%) were studied in the fasting state (plasma glucose, 11.1 +/- 1.1 mmol/L). A liquid meal of 400 mL containing 8% amino acids and 50 g sucrose (327 Kcal) was administered at time zero by a nasogastric tube. Gastric volume was determined by a dye dilution technique using phenol red. In randomized order, GLP-1-(7-36) amide (1.2 pmol/kg.min; Saxon Biochemicals) or placebo (0.9% NaCl with 1% human serum albumin) was infused between -30 and 240 min. In the control experiment, gastric emptying was completed within 120 min, and plasma glucose, insulin, C-peptide, GLP-1-(7-36) amide, and glucagon concentrations transiently increased. With exogenous GLP-1-(7-36) amide (plasma level, approximately 70 pmol/L), gastric volume remained constant over the period it was measured (120 min; P < 0.0001 vs. placebo), and plasma glucose fell to normal fasting values (5.4 +/- 0.7 mmol/L) within 3-4 h, whereas insulin was stimulated in most, but not all, patients, and glucagon remained at the basal level or was slightly suppressed. In conclusion, GLP-1-(7-36) amide inhibits gastric emptying in type 2 diabetic patients. Together with the stimulation of insulin and the inhibition of glucagon secretion, this effect probably contributes to the blood glucose-lowering action of GLP-1-(7-36) amide in type 2-diabetic patients when studied after meal ingestion. At the degree observed, inhibition of gastric emptying, however, must be overcome by tachyphylaxis, reduction in dose, or pharmacological interventions so as not to interfere with the therapeutic use of GLP-1-(7-36) amide in type 2 diabetic patients. Topics: Aged; Blood Glucose; Diabetes Mellitus, Type 2; Female; Gastric Emptying; Glucagon; Glucagon-Like Peptide 1; Humans; Insulin; Insulin Secretion; Male; Middle Aged; Peptide Fragments; Protein Precursors | 1996 |
Glucagonostatic actions and reduction of fasting hyperglycemia by exogenous glucagon-like peptide I(7-36) amide in type I diabetic patients.
Glucagon-like peptide I(7-36) amide (GLP-1) is a physiological incretin hormone that, in slightly supraphysiological doses, stimulates insulin secretion, lowers glucagon concentrations, and thereby normalizes elevated fasting plasma glucose concentrations in type II diabetic patients. It is not known whether GLP-1 has effects also in fasting type I diabetic patients.. In 11 type I diabetic patients (HbA1c 9.1 +/- 2.1%; normal, 4.2-6.3%), fasting hyperglycemia was provoked by halving their usual evening NPH insulin dose. In random order on two occasions, 1.2 pmol . kg-1 . min-1 GLP-1 or placebo was infused intravenously in the morning (plasma glucose 13.7 +/- 0.9 mmol/l; plasma insulin 26 +/- 4 pmol/l). Glucose (glucose oxidase method), insulin, C-peptide, glucagon, GLP-1, cortisol, growth hormone (immunoassays), triglycerides, cholesterol, and nonesterified fatty acids (enzymatic tests) were measured.. Glucagon was reduced from approximately 8 to 4 pmol/l, and plasma glucose was lowered from 13.4 +/- 1.0 to 10.0 +/- 1.2 mmol/l with GLP-1 administration (plasma concentrations approximately 100 pmol, P < 0.0001), but not with placebo (14.2 +/- 0.7 to 13.2 +/- 1.0). Transiently, C-peptide was stimulated from basal 0.09 +/- 0.02 to 0.19 +/- 0.06 nmol/l by GLP-1 (P < 0.0001), but not by placebo (0.07 +/- 0.02 to 0.07 +/- 0.02). There was no significant effect on nonesterified fatty acids (P = 0.34), triglycerides (P = 0.57), cholesterol (P = 0.64), cortisol (P = 0.40), or growth hormone (P = 0.53).. Therefore, exogenous GLP-1 is able to lower fasting glycemia also in type I diabetic patients, mainly by reducing glucagon concentrations. However, this alone is not sufficient to normalize fasting plasma glucose concentrations, as was previously observed in type II diabetic patients, in whom insulin secretion (C-peptide response) was stimulated 20-fold. Topics: Adult; Analysis of Variance; Blood Glucose; C-Peptide; Diabetes Mellitus, Type 1; Diabetes Mellitus, Type 2; Fasting; Fatty Acids, Nonesterified; Female; Glucagon; Glucagon-Like Peptide 1; Glucagon-Like Peptides; Humans; Insulin; Male; Peptide Fragments; Protein Precursors; Time Factors | 1996 |
Glucagon-like peptide I enhances the insulinotropic effect of glibenclamide in NIDDM patients and in the perfused rat pancreas.
To investigate the acute effects of glibenclamide and glucagon-like peptide I (GLP-I) and their combination in perfused isolated rat pancreas and in patients with secondary failure to sulfonylureas.. Rat islets were perfused with 10 nmol/l GLP-I in combination with 2 mumol/l glibenclamide. In human experiments, GLP-I (0.75 pmol. kg-1.min-1) was given as a continuous infusion during 240 min, while glibenclamide (3.5 mg) was administered orally. Eight patients participated in the study (age 57.6 +/- 2.7 years, BMI 28.7 +/- 1.5 kg/m2, mean +/- SE). In all subjects, blood glucose was first normalized by insulin infusion administered by an artificial pancreas (Biostator).. GLP-I increased the insulinotropic effect of glibenclamide fourfold in the perfused rat pancreas. In human experiments, treatment with GLP-I alone and in combination with glibenclamide significantly decreased basal glucose levels (5.1 +/- 0.4 and 4.5 +/- 0.1 vs. 6.0 +/- 0.3 mmol/l, P < 0.01), while with only glibenclamide, glucose concentrations remained unchanged. GLP-I markedly decreased total integrated glucose response to the meal (353 +/- 60 vs. 724 +/- 91 mmol.l-1. min-1, area under the curve [AUC] [-30-180 min], P < 0.02), whereas glibenclamide had no effect (598 +/- 101 mmol.l-1. min-1, AUC [-30-180 min], NS). The combined treatment further enhanced the glucose lowering effect of GLP-I (138 +/- 24 mmol. l-1.min, AUC [-30-180 min], P < 0.001). GLP-I, glibenclamide, and combined treat-stimulated meal-induced insulin release as reflected by insulinogenic indexes (control 1.44 +/- 0.4; GLP-I 6.3 +/- 1.6, P < 0.01; glibenclamide 6.8 +/- 2.1, P < 0.01; combination 20.7 +/- 5.0, P < 0.001). GLP-I inhibited basal but not postprandial glucagon responses. Using paracetamol as a marker for gastric emptying rate of the test meal, treatment with GLP-I decreased gastric emptying at 180 min by approximately 50% compared with the control subjects (P < 0.01).. In acute experiments on overweight patients with NIDDM, GLP-I exerted a marked antidiabetogenic action on the basal and postprandial state. The peptide stimulated insulin, suppressed basal glucagon release, and prolonged gastric emptying. The glucose-lowering effect of GLP-I was further enhanced by glibenclamide. This action may be at least partially accounted for by a synergistic effect of these two compounds on insulin release. Glibenclamide per se enhanced postprandial but not basal insulin release and exerted a less pronounced antidiabetogenic effect compared with GLP-I. Topics: Analysis of Variance; Animals; Diabetes Mellitus, Type 2; Drug Synergism; Drug Therapy, Combination; Gastric Emptying; Glucagon; Glucagon-Like Peptide 1; Glucagon-Like Peptides; Glyburide; Humans; In Vitro Techniques; Infusions, Intravenous; Insulin; Insulin Secretion; Islets of Langerhans; Middle Aged; Peptide Fragments; Perfusion; Protein Precursors; Rats; Rats, Sprague-Dawley; Treatment Failure | 1996 |
The antidiabetogenic effect of GLP-1 is maintained during a 7-day treatment period and improves diabetic dyslipoproteinemia in NIDDM patients.
To investigate the long-term antidiabetogenic effect of glucagon-like peptide 1 (GLP-1) and its influence on diabetic dyslipoproteinemia, patients with NIDDM were treated with GLP-1 subcutaneously for 1 week.. Twelve patients participated in the study. The 1st week of the study, all of them were on intensive insulin treatment and from day 8, four were randomized to a control group continuing with insulin, and eight to a treatment group where GLP-1 was given at meals together with regular insulin from day 8 to 12. On days 13 and 14, they were only given GLP-1 at meals. NPH insulin at bedtime was given throughout the study.. In the GLP-1-treated patients, the doses of regular insulin, given to keep a satisfactory blood glucose control, were reduced compared with treatment with insulin only. GLP-1 virtually inhibited the early increase in blood glucose after the meals, whereas an increase of approximately 2 mmol was seen during an optimized insulin treatment. In agreement with the short half-life of the peptide, 2-h postprandial plasma insulin levels were significantly decreased both at day 12 and 14, suggesting that there was not enough GLP-1 left to stimulate endogenous insulin release and compensate for the decrease in the dose of exogenous insulin. Therefore, the effect of GLP-1 was lost before the next meal, resulting in increased preprandial blood glucose values at lunch and dinner. The concentration of VLDL triglycerides decreased already during the 1st week. This decrease persisted during the 2nd week when GLP-1 was included in the treatment. No changes were observed in the levels of LDL and HDL cholesterol. The LDL particle diameter increased from a mean of 22.3 to 22.6 nm (P < 0.01) in response to insulin treatment. A further increment to 22.9 nm (P < 0.05) was seen after GLP-1 treatment. The LDL particle size did not change in the control group. Lipoprotein lipase activity was decreased by 27% and hepatic lipase was reduced by 13% in the GLP-1-treated group.. We confirm the antidiabetogenic effect of GLP-1 in NIDDM patients. This effect was maintained during 7 days, which implies that the patients did not develop tolerance during this treatment period. Intensive insulin treatment, leading to normotriglyceridemia, increased the mean LDL particle diameter, which is likely to lower the risk of future coronary heart disease in patients with NIDDM. Furthermore, an additive effect of GLP-1 is indicated. Hence, this study gives additional evidence that GLP-1 may be useful as an agent for treating NIDDM. Topics: Blood Glucose; C-Peptide; Cholesterol, HDL; Cholesterol, LDL; Diabetes Mellitus, Type 2; Female; Glucagon; Glucagon-Like Peptide 1; Glycated Hemoglobin; Humans; Hyperlipoproteinemias; Hypoglycemic Agents; Insulin; Lipoproteins, VLDL; Male; Middle Aged; Peptide Fragments; Protein Precursors; Time Factors; Triglycerides | 1996 |
Effects of subcutaneous glucagon-like peptide 1 (GLP-1 [7-36 amide]) in patients with NIDDM.
Intravenous glucagon-like peptide (GLP)-1 [7-36 amide] can normalize plasma glucose in non-insulin-dependent diabetic (NIDDM) patients. Since this is no form for routine therapeutic administration, effects of subcutaneous GLP-1 at a high dose (1.5 nmol/kg body weight) were examined. Three groups of 8, 9 and 7 patients (61 +/- 7, 61 +/- 9, 50 +/- 11 years; BMI 29.5 +/- 2.5, 26.1 +/- 2.3, 28.0 +/- 4.2 kg/m2; HbA1c 11.3 +/- 1.5, 9.9 +/- 1.0, 10.6 +/- 0.7%) were examined: after a single subcutaneous injection of 1.5 nmol/kg GLP [7-36 amide]; after repeated subcutaneous injections (0 and 120 min) in fasting patients; after a single, subcutaneous injection 30 min before a liquid test meal (amino acids 8%, and sucrose 50 g in 400 ml), all compared with a placebo. Glucose (glucose oxidase), insulin, C-peptide, GLP-1 and glucagon (specific immunoassays) were measured. Gastric emptying was assessed with the indicator-dilution method and phenol red. Repeated measures ANOVA was used for statistical analysis. GLP-1 injection led to a short-lived increment in GLP-1 concentrations (peak at 30-60 min, then return to basal levels after 90-120 min). Each GLP-1 injection stimulated insulin (insulin, C-peptide, p < 0.0001, respectively) and inhibited glucagon secretion (p < 0.0001). In fasting patients the repeated administration of GLP-1 normalized plasma glucose (5.8 +/- 0.4 mmol/l after 240 min vs 8.2 +/- 0.7 mmol/l after a single dose, p = 0.0065). With the meal, subcutaneous GLP-1 led to a complete cessation of gastric emptying for 30-45 min (p < 0.0001 statistically different from placebo) followed by emptying at a normal rate. As a consequence, integrated incremental glucose responses were reduced by 40% (p = 0.051). In conclusion, subcutaneous GLP-1 [7-36 amide] has similar effects in NIDDM patients as an intravenous infusion. Preparations with retarded release of GLP-1 would appear more suitable for therapeutic purposes because elevation of GLP-1 concentrations for 4 rather than 2 h (repeated doses) normalized fasting plasma glucose better. In the short term, there appears to be no tachyphylaxis, since insulin stimulation and glucagon suppression were similar upon repeated administrations of GLP-1 [7-36 amide]. It may be easier to influence fasting hyperglycaemia by GLP-1 than to reduce meal-related increments in glycaemia. Topics: Adult; Aged; Blood Glucose; C-Peptide; Cohort Studies; Diabetes Mellitus, Type 2; Fasting; Female; Gastric Emptying; Gastrointestinal Hormones; Glucagon; Glucagon-Like Peptide 1; Glucagon-Like Peptides; Humans; Injections, Subcutaneous; Insulin; Male; Middle Aged; Peptide Fragments; Peptides | 1996 |
Voglibose (AO-128) is an efficient alpha-glucosidase inhibitor and mobilizes the endogenous GLP-1 reserve.
The alpha-glucosidase inhibitor voglibose (AO-128) was designed to prevent rapid postprandial blood glucose rises in non-insulin-dependent diabetics. We analyzed its effect on the entero-insular axis in 72 healthy volunteers in a double-blind study design before, after the 1st dose, and on the 7th day of a 7-day treatment protocol (3 daily loads). Six parallel groups of 12 volunteers received voglibose (0.5, 1.0, 2.0, or 5.0 mg) or placebo (two groups). Blood was drawn at regular intervals up to 180 min after a standardized breakfast to analyze the levels of glucose, insulin, C peptide, gastric inhibitory polypeptide, and glucagon-like peptide 1 (GLP-1). As expected, after ingestion of voglibose, slight to moderate gastro-intestinal discomfort but no severe side-effects were reported. In a dose-dependent manner, voglibose significantly reduced postprandial increases of blood glucose, insulin, and C peptide. At the lower loads (0.5 and 1 mg voglibose three times daily), these effects were more pronounced after 7 days. The postprandial increase of gastric inhibitory polypeptide was already reduced after the first load of 2 and 5 mg voglibose. In comparison to the placebo group, this inhibition became also significant for the lower loads after 7 days. Interestingly, GLP-1, originating from the lower intestines, was increasingly released under voglibose treatment. The first administration of 1 mg voglibose enhanced GLP-1 secretion > 80% above controls. Treatment with 1 mg voglibose three times daily over 7 days revealed a maximal mobilizing effect on endogenous GLP-1 (> 90% above controls) which was not further increased by 2- or 5-mg loads. We conclude that voglibose treatment effectively inhibits intestinal disaccharidases and thereby mobilizes the endogenous pool of insulinotropic GLP-1. Topics: Adolescent; Adult; Blood Glucose; C-Peptide; Cyclohexanols; Diabetes Mellitus, Type 2; Dose-Response Relationship, Drug; Double-Blind Method; Enzyme Inhibitors; Gastric Inhibitory Polypeptide; Glucagon; Glucagon-Like Peptide 1; Glycoside Hydrolase Inhibitors; Humans; Insulin; Male; Peptide Fragments; Protein Precursors | 1995 |
Subcutaneous injection of the incretin hormone glucagon-like peptide 1 abolishes postprandial glycemia in NIDDM.
To investigate the effect of subcutaneously injected glucagon-like peptide 1 (GLP-1) (7-36)amide on postprandial plasma glucose, insulin, and C-peptide levels in patients with non-insulin-dependent diabetes mellitus (NIDDM) and a secondary failure to sulfonylureas.. GLP-1 (25 nmol) was injected subcutaneously into either the abdominal wall or the gluteal region at a standardized depth and speed. The injection device was guided by the ultrasound determination of the depth of the fat layer. The peptide was given 5 min before a standard meal. Plasma concentrations of glucose, C-peptide, insulin, glucagon, and GLP-1 were followed during 240 min after the injection.. In control experiments, a significant hyperglycemia was attained after the meal. GLP-1 given into the abdominal wall not only virtually abolished the post-prandial blood glucose rise but significantly decreased glucose concentrations, with a nadir at approximately 25 min after the injection. A rapid rise of C-peptide and insulin levels was observed 10-15 min after the injection of GLP-1. The stimulatory effect of GLP-1 was transient, and, at 45 min after the meal, both insulin and C-peptide levels were almost identical in GLP-1 and control experiments. Significantly lower glucagon concentrations were observed 35-65 min after the peptide injection. GLP-1 concentration in plasma increased from 10 pM to a peak concentration (Cmax) of 70 pM at Tmax 30 min after injection. Then GLP-1 levels rapidly decreased to 25 pM at 95 min and returned to basal at 215 min. The gluteal injection of GLP-1 had similar effects compared with the abdominal administration on plasma levels of glucose, insulin, C-peptide, and glucagon.. GLP-1 is promptly absorbed from the subcutaneous tissue. It exerts a significant blood glucose lowering effect when administered before meals in overweight patients with NIDDM. Topics: Blood Glucose; C-Peptide; Diabetes Mellitus, Type 2; Eating; Female; Glucagon; Glucagon-Like Peptide 1; Humans; Hyperglycemia; Injections, Subcutaneous; Insulin; Male; Middle Aged; Peptide Fragments; Protein Precursors; Radioimmunoassay; Time Factors | 1994 |
Normalization of fasting hyperglycaemia by exogenous glucagon-like peptide 1 (7-36 amide) in type 2 (non-insulin-dependent) diabetic patients.
Glucagon-like peptide 1 (GLP-1) (7-36 amide) is a physiological incretin hormone that is released after nutrient intake from the lower gut and stimulates insulin secretion at elevated plasma glucose concentrations. Previous work has shown that even in Type 2 (non-insulin-dependent) diabetic patients GLP-1 (7-36 amide) retains much of its insulinotropic action. However, it is not known whether the magnitude of this response is sufficient to normalize plasma glucose in Type 2 diabetic patients with poor metabolic control. Therefore, in 10 Type 2 diabetic patients with unsatisfactory metabolic control (HbA1c 11.6 +/- 1.7%) on diet and sulphonylurea therapy (in some patients supplemented by metformin or acarbose), 1.2 pmol x kg-1 x min-1 GLP-1 (7-36 amide) or placebo was infused intravenously in the fasting state (plasma glucose 13.1 +/- 0.6 mmol/l). In all patients, insulin (by 17.4 +/- 4.7 nmol x 1-1 x min; p = 0.0157) and C-peptide (by 228.0 +/- 39.1 nmol x 1-1 x min; p = 0.0019) increased significantly over basal levels, glucagon was reduced (by -1418 +/- 308 pmol x 1-1 x min) and plasma glucose reached normal fasting concentrations (4.9 +/- 0.3 mmol/l) within 4 h of GLP-1 (7-36 amide) administration, but not with placebo. When normal fasting plasma glucose concentrations were reached insulin returned towards basal levels and plasma glucose concentrations remained stable despite the ongoing infusion of GLP-1 (7-36 amide). Therefore, exogenous GLP-1 (7-36 amide) is an effective means of normalizing fasting plasma glucose concentrations in poorly-controlled Type 2 diabetic patients.(ABSTRACT TRUNCATED AT 250 WORDS) Topics: Adult; Blood Glucose; Diabetes Mellitus, Type 2; Fasting; Female; Glucagon; Glucagon-Like Peptide 1; Glucagon-Like Peptides; Glycated Hemoglobin; Humans; Hyperglycemia; Hypoglycemic Agents; Infusions, Intravenous; Kinetics; Male; Middle Aged; Peptide Fragments; Time Factors | 1993 |
Preserved incretin activity of glucagon-like peptide 1 [7-36 amide] but not of synthetic human gastric inhibitory polypeptide in patients with type-2 diabetes mellitus.
In type-2 diabetes, the overall incretin effect is reduced. The present investigation was designed to compare insulinotropic actions of exogenous incretin hormones (gastric inhibitory peptide [GIP] and glucagon-like peptide 1 [GLP-1] [7-36 amide]) in nine type-2 diabetic patients (fasting plasma glucose 7.8 mmol/liter; hemoglobin A1c 6.3 +/- 0.6%) and in nine age- and weight-matched normal subjects. Synthetic human GIP (0.8 and 2.4 pmol/kg.min over 1 h each), GLP-1 [7-36 amide] (0.4 and 1.2 pmol/kg.min over 1 h each), and placebo were administered under hyperglycemic clamp conditions (8.75 mmol/liter) in separate experiments. Plasma GIP and GLP-1 [7-36 amide] concentrations (radioimmunoassay) were comparable to those after oral glucose with the low, and clearly supraphysiological with the high infusion rates. Both GIP and GLP-1 [7-36 amide] dose-dependently augmented insulin secretion (insulin, C-peptide) in both groups (P < 0.05). With GIP, the maximum effect in type-2 diabetic patients was significantly lower (by 54%; P < 0.05) than in normal subjects. With GLP-1 [7-36 amide] type-2 diabetic patients reached 71% of the increments in C-peptide of normal subjects (difference not significant). Glucagon was lowered during hyperglycemic clamps in normal subjects, but not in type-2 diabetic patients, and further by GLP-1 [7-36 amide] in both groups (P < 0.05), but not by GIP. In conclusion, in mild type-2 diabetes, GLP-1 [7-36 amide], in contrast to GIP, retains much of its insulinotropic activity. It also lowers glucagon concentrations. Topics: Blood Glucose; C-Peptide; Diabetes Mellitus, Type 2; Female; Gastric Inhibitory Polypeptide; Glucagon; Glucagon-Like Peptide 1; Glucagon-Like Peptides; Glucose Clamp Technique; Glycated Hemoglobin; Humans; Insulin; Insulin Secretion; Kinetics; Male; Middle Aged; Peptide Fragments; Protein Precursors; Reference Values; Time Factors | 1993 |
Insulinotropic action of glucagonlike peptide-I-(7-37) in diabetic and nondiabetic subjects.
Whether glucagonlike peptide-I-(7-37) (GLP-I-[7-37]), a naturally occurring intestinal peptide, is insulinotropic in nondiabetic and non-insulin-dependent (type II) diabetic subjects.. GLP-I-(7-37) or saline placebo was infused (1-5 ng.kg-1.min-1 for 30 min) in 4 nondiabetic and 11 type II diabetic subjects in the fasting and prandial state. Glucose, insulin, and GLP-I-(7-37) levels were measured.. GLP-I-(7-37) infusion resulted in a 3- to 10-fold increase in peak insulin levels and in insulin area under the curve in nondiabetic and diabetic subjects. In diabetic subjects, infusion concurrent with a standard meal eliminated the postprandial glucose excursion for 60 min after the meal. Insulin-releasing potency of GLP-I-(7-37) was attenuated at decreased glucose levels.. GLP-I-(7-37) has potent insulinotropic effects in nondiabetic and diabetic subjects. Whether GLP-I-(7-37) is useful as a therapeutic medication in type II diabetes requires further investigation. Topics: Adult; Aged; Blood Glucose; Diabetes Mellitus, Type 2; Eating; Fasting; Female; Glucagon; Glucagon-Like Peptide 1; Glucagon-Like Peptides; Humans; Insulin; Kinetics; Male; Middle Aged; Peptide Fragments; Peptides; Reference Values; Time Factors | 1992 |
1571 other study(ies) available for glucagon-like-peptide-1 and Diabetes-Mellitus--Type-2
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Relevance of GLP-1 receptor agonists or SGLT-2 inhibitors on the recruitment for clinical studies in patients with NAFLD.
Guidelines increasingly recommend the use of glucagon-like peptide-1 receptor agonists (GLP-1 RA) or sodium-glucose co-transporter-2 inhibitors (SGLT2i) to prevent cardiovascular and cardiorenal endpoints. Both drugs also show beneficial effects in nonalcoholic fatty liver disease (NAFLD). Preexisting GLP-1 RA and SGLT2i therapies are frequently defined as exclusion criterion in clinical studies to avoid confounding effects. We therefore investigated how this might limit recruitment and design of NAFLD studies.. GLP-1 RA and SGLT2i prescriptions were analyzed in NAFLD patients with diabetes mellitus recruited at a tertiary referral center and from the population-based LIFE-Adult-Study. Individuals were stratified according to noninvasive parameters of liver fibrosis based on vibration-controlled transient elastography (VCTE).. 97 individuals were recruited at tertiary care and 473 from the LIFE-Adult-Study. VCTE was available in 97/97 and 147/473 cases.GLP-1 RA or SGLT2i were used in 11.9% of the population-based cohort (LSM < 8 kPa), but in 32.0% with LSM ≥ 8 kPa. In the tertiary clinic, it was 30.9% overall, independent of LSM, and 36.8% in patients with medium and high risk for fibrotic NASH (FAST score > 0.35). At baseline, 3.1% of the patients in tertiary care were taking GLP-1 RA and 4.1% SGLT2i. Four years later, the numbers had increased to 15.5% and 21.6%.. GLP-1 RA and SGLT2i are frequently and increasingly prescribed. In candidates for liver biopsy for NASH studies (VCTE ≥ 8 kPa) the use of them exceeds 30%, which needs careful consideration when designing NASH trials. Topics: Adult; Diabetes Mellitus, Type 2; Glucagon-Like Peptide 1; Glucagon-Like Peptide-1 Receptor; Humans; Hypoglycemic Agents; Liver Cirrhosis; Non-alcoholic Fatty Liver Disease; Sodium-Glucose Transporter 2 Inhibitors | 2024 |
High unmet treatment needs in patients with chronic kidney disease and type 2 diabetes: real-world evidence from a US claims database.
Chronic kidney disease (CKD), a serious complication of type 2 diabetes (T2D) increases the comorbid risk of cardiovascular disease (CVD) and end-stage kidney disease(ESKD). Treatment guidelines recommend renin-angiotensin blockade and antihyperglycemic treatment with metformin and sodium-glucose cotransporter 2 inhibitors (SGLT2is) as first-line treatment. We evaluated treatment initiation and discontinuation overall and in subgroups of T2D patients with incident CKD (incident cohort) and rates of clinical and economic outcomes in patients with T2D and any CKD (prevalent cohort).. In this retrospective study of administrative claims in the USA between 1 January 2007 and 31 March 2019, we evaluated the proportion of patients with concomitant, newly initiated and discontinued use of antihypertensive [angiotensin-converting enzyme inhibitor (ACEi)/angiotensin II receptor blockers (ARBs), steroidal mineralocorticoid receptor antagonists (sMRAs)] and antidiabetic [SGLT2is, dipeptidyl peptidase-4 inhibitors (DPP4is), glucagon-like peptide-1 receptor agonists (GLP-1 RAs), insulin and sulfonylureas] medications, rates of clinical outcomes per 1000 person-years and mean total healthcare costs.. We identified 63 127 and 326 763 patients in the incident and prevalent CKD cohorts, respectively. Low initiation and high discontinuation rates were observed with 17.8% and 56.0% for ACEi/ARBs, 1.3% and 66.0% for sMRAs, 2.5% and 65.0% for SGLT2is, 3.7% and 66.8% for DPP4is, 2.31% and 69.0% for GLP-1 RAs, 4% and 75.7% for insulin and 5.5% and 56.9% for sulfonylureas. Similar results were seen by subgroups. Rates of clinical outcomes ranged from 35.07 per 1000 person-years for all-cause mortality to 104.19 for ESKD, with rates of hospitalization ranging from 36.61 for kidney hospitalizations to 283.14 for all-cause hospitalizations. Among patients with comorbidities, higher clinical and economic outcomes were found.. Our results highlight high unmet needs of CKD and T2D, particularly subgroups of patients with multimorbid CVD, high-risk CKD (low estimated glomerular filtration rate or high urinary albumin:creatinine ratio) or rapidly progressing CKD. Low initiation and high discontinuation of recommended treatments suggest that adherence to guidelines for halting CKD progression is suboptimal. These high-risk patients may benefit from further treatment options to improve morbidity and mortality and reduce the economic burden. Topics: Angiotensin Receptor Antagonists; Angiotensin-Converting Enzyme Inhibitors; Cardiovascular Diseases; Diabetes Mellitus, Type 2; Glucagon-Like Peptide 1; Humans; Hypoglycemic Agents; Insulins; Renal Insufficiency, Chronic; Retrospective Studies | 2023 |
Comparison of the Effectiveness of Liraglutide vs Semaglutide in a Veteran Population.
Topics: Cohort Studies; Diabetes Mellitus, Type 2; Glucagon-Like Peptide 1; Glycated Hemoglobin; Humans; Hypoglycemic Agents; Insulin; Liraglutide; Retrospective Studies; Veterans | 2023 |
Disutility of injectable therapies in obesity and type 2 diabetes mellitus: general population preferences in the UK, Canada, and China.
Once-daily and once-weekly injectable glucagon-like peptide-1 receptor agonist therapies (GLP-1 RAs) are established in obesity and type 2 diabetes mellitus (T2DM). In T2DM, both once-daily and once-weekly insulin are expected to be available. This study elicited utilities associated with these treatment regimens from members of the general public in the UK, Canada, and China, to quantify administration-related disutility of more-frequent injectable treatment, and allow economic modelling.. Two anchor states (no pharmacological treatment), and seven treatment states (daily oral tablet and generic injectable regimens of variable frequency), with identical outcomes were tested A broadly representative sample of the general public in each country participated (excluding individuals with diabetes or pharmacologically treated obesity). An adapted Measurement and Valuation of Health protocol was administered 1:1 in web-enabled interviews by trained moderators: visual analogue scale (VAS) as a "warm-up", and time trade-off (TTO) using a 20-year time horizon for utility elicitation.. A total of 310 individuals participated. The average disutility of once-daily versus once-weekly GLP-1 RA was - 0.048 in obesity and - 0.033 in T2DM; the corresponding average disutility for insulin was - 0.064. Disutilities were substantially greater in China, relative to UK and Canada.. Within obesity and T2DM, more-frequent treatment health states had lower utility. Scores by VAS also followed a logical order. The generated utility values are suitable for use in modelling injectable therapy regimens in obesity and T2DM, due to the use of generic descriptions and assumption of equal efficacy. Future research could examine the reasons for greater administration-related disutility in China. Topics: Diabetes Mellitus, Type 2; Glucagon-Like Peptide 1; Humans; Hypoglycemic Agents; Insulin; Obesity; United Kingdom | 2023 |
The Effects of Adding Semaglutide to High Daily Dose Insulin Regimens in Patients With Type 2 Diabetes.
Escalating doses of insulin required with progression of type 2 diabetes may lead to weight gain. Weight loss associated with semaglutide may be beneficial. However, data on the use of semaglutide in patients requiring high daily doses of insulin are currently lacking.. The purpose of this project was to evaluate the impact of semaglutide on total daily dose (TDD) of insulin when initiated in patients with type 2 diabetes mellitus (T2DM) on high daily doses of insulin. Secondary objectives assessed included changes in weight, body mass index (BMI), blood pressure, heart rate, and diabetes and blood pressure medications.. This IRB exempt retrospective medical record review included patients with T2DM prescribed semaglutide and at least 100 units TDD of insulin between January 1, 2019, and December 31, 2019.. Of the 72 patients included, the TDD of insulin decreased from baseline to 6 months (183 ± 98 units and 143 ± 99 units,. Improvement in glycemic control occurred despite reductions in TDD of insulin. Improvements in A1c and body weight were clinically significant. This analysis adds to existing literature supporting the use of GLP-1 RAs in patients on high daily doses of insulin. Topics: Diabetes Mellitus, Type 2; Glucagon-Like Peptide 1; Glucagon-Like Peptide-1 Receptor; Glucagon-Like Peptides; Glycated Hemoglobin; Humans; Hypoglycemic Agents; Insulin; Retrospective Studies; Weight Loss | 2023 |
Glucagon-like Peptide-1 Receptor-based Therapeutics for Metabolic Liver Disease.
Glucagon-like peptide-1 (GLP-1) controls islet hormone secretion, gut motility, and body weight, supporting development of GLP-1 receptor agonists (GLP-1RA) for the treatment of type 2 diabetes (T2D) and obesity. GLP-1RA exhibit a favorable safety profile and reduce the incidence of major adverse cardiovascular events in people with T2D. Considerable preclinical data, supported by the results of clinical trials, link therapy with GLP-RA to reduction of hepatic inflammation, steatosis, and fibrosis. Mechanistically, the actions of GLP-1 on the liver are primarily indirect, as hepatocytes, Kupffer cells, and stellate cells do not express the canonical GLP-1R. GLP-1RA reduce appetite and body weight, decrease postprandial lipoprotein secretion, and attenuate systemic and tissue inflammation, actions that may contribute to attenuation of metabolic-associated fatty liver disease (MAFLD). Here we discuss evolving concepts of GLP-1 action that improve liver health and highlight evidence that links sustained GLP-1R activation in distinct cell types to control of hepatic glucose and lipid metabolism, and reduction of experimental and clinical nonalcoholic steatohepatitis (NASH). The therapeutic potential of GLP-1RA alone, or in combination with peptide agonists, or new small molecule therapeutics is discussed in the context of potential efficacy and safety. Ongoing trials in people with obesity will further clarify the safety of GLP-1RA, and pivotal studies underway in people with NASH will define whether GLP-1-based medicines represent effective and safe therapies for people with MAFLD. Topics: Diabetes Mellitus, Type 2; Glucagon-Like Peptide 1; Glucagon-Like Peptide-1 Receptor; Humans; Hypoglycemic Agents; Inflammation; Non-alcoholic Fatty Liver Disease; Obesity | 2023 |
Cardiovascular effects of incretins: focus on glucagon-like peptide-1 receptor agonists.
Glucagon-like peptide-1 receptor agonists (GLP-1 RAs) have been used to treat patients with type 2 diabetes since 2005 and have become popular because of the efficacy and durability in relation to glycaemic control in combination with weight loss in most patients. Today in 2022, seven GLP-1 RAs, including oral semaglutide are available for treatment of type 2 diabetes. Since the efficacy in relation to reduction of HbA1c and body weight as well as tolerability and dosing frequency vary between agents, the GLP-1 RAs cannot be considered equal. The short acting lixisenatide showed no cardiovascular benefits, while once daily liraglutide and the weekly agonists, subcutaneous semaglutide, dulaglutide, and efpeglenatide, all lowered the incidence of cardiovascular events. Liraglutide, oral semaglutide and exenatide once weekly also reduced mortality. GLP-1 RAs reduce the progression of diabetic kidney disease. In the 2019 consensus report from European Association for the Study of Diabetes/American Diabetes Association, GLP-1 RAs with demonstrated cardio-renal benefits (liraglutide, semaglutide and dulaglutide) are recommended after metformin to patients with established cardiovascular diseases or multiple cardiovascular risk factors. European Society of Cardiology suggests starting with a sodium-glucose cotransprter-2 inhibitor or a GLP-1 RA in drug naïve patients with type 2 diabetes (T2D) and atherosclerotic cardiovascular disease (CVD) or high CV Risk. However, the results from cardiovascular outcome trials (CVOT) are very heterogeneous suggesting that some GLP-1RAs are more suitable to prevent CVD than others. The CVOTs provide a basis upon which individual treatment decisions for patients with T2D and CVD can be made. Topics: Cardiovascular Diseases; Diabetes Mellitus, Type 2; Glucagon-Like Peptide 1; Glucagon-Like Peptide-1 Receptor; Humans; Hypoglycemic Agents; Incretins; Liraglutide | 2023 |
Effects of site-directed mutagenesis of GLP-1 and glucagon receptors on signal transduction activated by dual and triple agonists.
The paradigm of one drug against multiple targets, known as unimolecular polypharmacology, offers the potential to improve efficacy while overcoming some adverse events associated with the treatment. This approach is best exemplified by targeting two or three class B1 G protein-coupled receptors, namely, glucagon-like peptide-1 receptor (GLP-1R), glucagon receptor (GCGR) and glucose-dependent insulinotropic polypeptide receptor for treatment of type 2 diabetes and obesity. Some of the dual and triple agonists have already shown initial successes in clinical trials, although the molecular mechanisms underlying their multiplexed pharmacology remain elusive. In this study we employed structure-based site-directed mutagenesis together with pharmacological assays to compare agonist efficacy across two key signaling pathways, cAMP accumulation and ERK1/2 phosphorylation (pERK1/2). Three dual agonists (peptide 15, MEDI0382 and SAR425899) and one triple agonist (peptide 20) were evaluated at GLP-1R and GCGR, relative to the native peptidic ligands (GLP-1 and glucagon). Our results reveal the existence of residue networks crucial for unimolecular agonist-mediated receptor activation and their distinct signaling patterns, which might be useful to the rational design of biased drug leads. Topics: Diabetes Mellitus, Type 2; Glucagon-Like Peptide 1; Glucagon-Like Peptide-1 Receptor; Humans; Mutagenesis, Site-Directed; Peptides; Receptors, Glucagon; Signal Transduction; Transcription Factors | 2023 |
Diabetes of Unclear Type in an Adolescent Boy With Multiple Islet-cell Autoantibody Positivity Successfully Managed With Glucagon-like Peptide-1 Receptor Agonist Alone: A Case Report.
Diabetes classification has traditionally considered type 1 and type 2 diabetes as 2 separate entities with different pathogenic mechanisms. However, clinicians and researchers see increasingly more exceptions to this conventional paradigm, leading to a concept of mixed phenotypes in diabetes classification. Herein we report the case of an adolescent with unclear diabetes type due to the presence of obesity, robust endogenous insulin production, multiple islet autoantibody positivity and severe hyperglycemia at diabetes diagnosis that has been successfully treated with liraglutide therapy alone. Our case report highlights the difficulty of diabetes classification and subsequent need for personalized medicine with regard to diabetes management. Topics: Autoantibodies; Diabetes Mellitus, Type 2; Glucagon-Like Peptide 1; Glucagon-Like Peptide-1 Receptor; Humans; Hypoglycemic Agents; Insulin; Liraglutide | 2023 |
Cardiovascular disease management in Australian adults with type 2 diabetes: insights from the CAPTURE study.
Type 2 diabetes (T2D) is a well-recognised cardiovascular disease (CVD) risk factor, and recent guidelines for the management of T2D include consideration of CVD risk.. To assess whether contemporary clinical management of Australians with T2D is in accord with recent national and international guidelines.. This Australia-specific analysis of the CAPTURE study, a non-interventional, cross-sectional study included adults diagnosed with T2D ≥180 days prior to providing informed consent and visiting primary or specialist care. Main outcome measures were the use of blood glucose-lowering medications (BGLMs), BGLMs with proven cardiovascular benefits and other CVD medications, stratified by CVD status and care setting.. Of 824 Australian participants in the CAPTURE sample, 332 (40.3%) had CVD. Oral BGLMs were used by 83.9% of all participants, most commonly metformin (76.0%), dipeptidyl peptidase-4 inhibitors (28.8%), sodium-glucose cotransporter-2 inhibitors (SGLT2is; 21.8%) and sulfonylureas (21.7%). Insulin was used by 29.2% of participants. BGLMs with proven CV benefit were used by 22.6%; glucagon-like peptide-1 receptor agonists (GLP-1 RAs) were less commonly used than SGLT2is in all CVD groups, but these drug classes were more often prescribed in specialist than primary care (SGLT2is 25.4 vs 20.7%, GLP-1 RAs 3.2 vs 0.8% respectively). Use of non-BGLMs for CVD risk reduction appeared consistent with guidelines.. Use of BGLMs with CVD benefits appears low in Australia, irrespective of CVD status. This likely reflects the delay in translation of clinical evidence into contemporary care and prescribing restrictions. Topics: Adult; Australia; Blood Glucose; Cardiovascular Diseases; Cross-Sectional Studies; Diabetes Mellitus, Type 2; Glucagon-Like Peptide 1; Glucose; Humans; Hypoglycemic Agents; Sodium-Glucose Transporter 2 Inhibitors | 2023 |
Hectogram-scale synthesis of [Aib
Based on small-scale synthesis (0.3 g), a 100-g scale-up synthesis of crude [Aib Topics: Diabetes Mellitus, Type 2; Glucagon-Like Peptide 1; Glucagon-Like Peptide-1 Receptor; Humans; Hypoglycemic Agents; Peptide Fragments | 2023 |
De-intensification of basal-bolus insulin regimen after initiation of a GLP-1 RA improves glycaemic control and promotes weight loss in subjects with type 2 diabetes.
To evaluate the impact of adding a glucagon-like peptide-1 receptor agonist (GLP-1 RA) in people with type 2 diabetes (T2D) in basal-bolus (BB) insulin regimen, on insulin requirement, HbA1c, weight loss up to 24 months.. Data on subjects with T2D on BB who initiated a GLP-1 RA have been retrospectively collected. HbA1c, body weight, and insulin dose were recorded at baseline, 6, 12, and 24 months after initiation of GLP-1 RA therapy. A linear mixed model for repeated measures was used to evaluate the changes in HbA1c, body weight, and insulin requirement over time.. We included 156 subjects (63.5% males; age 62 ± 11 years, HbA1c 70 ± 22.0 mmol/mol; 8.6 ± 4.2%). Compared to baseline, HbA1c and body weight were significantly lower at 6 months after introducing a GLP-1RA and remained stable up to 24 months (all p < 0.0001 vs. baseline). At 24 months, 81% of subjects discontinued prandial insulin, while 38.6% discontinued basal insulin as well. Insulin requirement at baseline (aOR 0.144; 95% CI, 0.046-0.456; P = 0.001) was the only significant predictor of prandial insulin discontinuation.. Replacing prandial insulin with GLP-1 RA is a valuable strategy to simplify the BB insulin regimen while improving glycaemic control and promoting weight loss in subjects with T2D. Topics: Aged; Blood Glucose; Body Weight; Diabetes Mellitus, Type 2; Female; Glucagon-Like Peptide 1; Glucagon-Like Peptide-1 Receptor; Glycated Hemoglobin; Glycemic Control; Humans; Hypoglycemic Agents; Insulin; Male; Middle Aged; Retrospective Studies; Weight Loss | 2023 |
Increased expression of glucagon-like peptide-1 and cystic fibrosis transmembrane conductance regulator in the ileum and colon in mouse treated with metformin.
Topics: Animals; Caco-2 Cells; Colon; Creosote; Cyclic AMP; Cystic Fibrosis Transmembrane Conductance Regulator; Diabetes Mellitus, Type 2; Diarrhea; Glucagon-Like Peptide 1; Humans; Ileum; Metformin; Mice; Mice, Inbred C57BL; RNA, Messenger | 2023 |
Cardiovascular risk and lifetime benefit from preventive treatment in type 2 diabetes: A post hoc analysis of the CAPTURE study.
To assess the potential gain in the number of life-years free of a (recurrent) cardiovascular disease (CVD) event with optimal cardiovascular risk management (CVRM) and initiation of glucose-lowering agents with proven cardiovascular benefit in people with type 2 diabetes (T2D).. 9,416 individuals with T2D from the CAPTURE study, a non-interventional, cross-sectional, multinational study, were included. The diabetes lifetime-perspective prediction model was used for calculating individual 10-year and lifetime CVD risk. The distribution of preventive medication use was assessed according to predicted CVD risk and stratified for history of CVD. For the estimation of absolute individual benefit from lifelong preventive treatment, including optimal CVRM and the addition of glucagon-like peptide-1 receptor agonists (GLP-1 RAs) and sodium-glucose co-transporter-2 inhibitors (SGLT-2is), the model was combined with treatment effects from current evidence.. GLP-1 RA or SGLT-2i use did not greatly differ between patients with and without CVD history, while use of blood pressure-lowering medication, statins and aspirin was more frequent in patients with CVD. Mean (standard deviation [SD]) lifetime benefit from optimal CVRM was 3.9 (3.0) and 1.3 (1.9) years in patients with and without established CVD, respectively. Further addition of a GLP-1 RA and an SGLT-2i in patients with CVD gave an added mean (SD) lifetime benefit of 1.2 (0.6) years.. Life-years gained free of (recurrent) CVD by optimal CVRM and the addition of a GLP-1 RA or aSGLT-2i is dependent on baseline CVD status. These results aid individualizing prevention and promote shared decision-making in patients with T2D. Topics: Cardiovascular Diseases; Cross-Sectional Studies; Diabetes Mellitus, Type 2; Glucagon-Like Peptide 1; Glucagon-Like Peptide-1 Receptor; Glucose; Heart Disease Risk Factors; Humans; Hypoglycemic Agents; Risk Factors; Sodium-Glucose Transporter 2 Inhibitors | 2023 |
Impact of Lycium barbarum polysaccharide on the expression of glucagon-like peptide 1 in vitro and in vivo.
Topics: alpha-Glucosidases; Animals; Diabetes Mellitus, Type 2; Drugs, Chinese Herbal; Glucagon-Like Peptide 1; Hypoglycemic Agents; Lycium; Mice | 2023 |
Use of Sodium-Glucose Cotransporter 2 Inhibitors and Glucagonlike Peptide-1 Receptor Agonists in Patients With Diabetes and Cardiovascular Disease in Community Practice.
Recent national guidelines recommend sodium-glucose cotransporter 2 inhibitors (SGLT2i) and glucagonlike peptide-1 receptor agonists (GLP-1 RA) in patients with type 2 diabetes (T2D) and atherosclerotic cardiovascular disease (ASCVD); yet, there are limited data on the use of these agents in contemporary community practice.. To evaluate the use of SGLT2i and GLP-1 RA in adults with T2D and ASCVD across a diverse sample of health care systems in the US.. This multicenter, retrospective cohort study used electronic health record data from 88 US health care systems participating in Cerner Real World Data between January 2018 to March 2021. Adults with ASCVD and T2D taking at least 1 glucose-lowering medication, had end-stage kidney disease, or had stage 5 chronic kidney disease were excluded.. Treatment with SGLT2i or GLP-1 RA.. A total of 321 304 patients were identified with T2D and ASCVD ASCVD (130 280 female [40.5%]; median [IQR] age, 70.9 [62.9-78.0] years) who were potentially eligible for SGLT2i and/or GLP-1 RA, including 37 754 Black individuals (11.8%), 51 522 Hispanic individuals (16.0%), and 256 008 White individuals (11.8%). From January 2018 to March 2021, the use of SGLT2i increased from 5.8% (11 285 of 194 264) to 12.9% (11 058 of 85 956), GLP-1 RA increased from 6.9% (13 402 of 194 264) to 13.8% (11 901 of 85 956), and use of either agent increased from 11.4% (22 069 of 194 264) to 23.2% (19 909 of 85 956). Those taking an SGLT2i or GLP-1 RA were younger, less frequently hospitalized in the year prior, and more likely to be taking additional secondary prevention medications. Treated and nontreated populations were similar in terms of race, ethnicity, and outpatient health care utilization. Sulfonylureas and dipeptidyl peptidase 4 inhibitors remained more commonly used than SGLT2i or GLP-1 RA through 2021.. In this study, uptake of SGLT2i and GLP-1 RA in adults with T2D and ASCVD increased modestly after guideline recommendations, although less than a quarter of persons with ASCVD and T2D receiving medical therapy were taking either. Further efforts are necessary to maximize the potential population benefit of these therapies in this high-risk population. Topics: Adult; Aged; Cardiovascular Diseases; Diabetes Mellitus, Type 2; Female; Glucagon-Like Peptide 1; Glucose; Humans; Hypoglycemic Agents; Peptides; Retrospective Studies; Sodium; Sodium-Glucose Transporter 2 Inhibitors | 2023 |
GLP-1 Receptor Agonists and the Risk of Thyroid Cancer.
To determine whether use of glucagon-like peptide 1 (GLP-1) receptor agonists (RA) is associated with increased risk of thyroid cancer.. A nested case-control analysis was performed with use of the French national health care insurance system (SNDS) database. Individuals with type 2 diabetes treated with second-line antidiabetes drugs between 2006 and 2018 were included in the cohort. All thyroid cancers were identified through hospital discharge diagnoses and medical procedures between 2014 and 2018. Exposure to GLP-1 RA was measured within the 6 years preceding a 6-month lag-time period and considered as current use and cumulative duration of use based on defined daily dose (≤1, 1 to 3, >3 years). Case subjects were matched with up to 20 control subjects on age, sex, and length of diabetes with the risk-set sampling procedure. Risk of thyroid cancer related to use of GLP-1 RA was estimated with a conditional logistic regression with adjustment for goiter, hypothyroidism, hyperthyroidism, other antidiabetes drugs, and social deprivation index.. A total of 2,562 case subjects with thyroid cancers were included in the study and matched with 45,184 control subjects. Use of GLP-1 RA for 1-3 years was associated with increased risk of all thyroid cancer (adjusted hazard ratio [HR] 1.58, 95% CI 1.27-1.95) and medullary thyroid cancer (adjusted HR 1.78, 95% CI 1.04-3.05).. In the current study we found increased risk of all thyroid cancer and medullary thyroid cancer with use of GLP-1 RA, in particular after 1-3 years of treatment. Topics: Diabetes Mellitus, Type 2; Glucagon-Like Peptide 1; Glucagon-Like Peptide-1 Receptor; Humans; Hypoglycemic Agents; Thyroid Neoplasms | 2023 |
Deficits and Disparities in Early Uptake of Glucagon-Like Peptide 1 Receptor Agonists and SGLT2i Among Medicare-Insured Adults Following a New Diagnosis of Cardiovascular Disease or Heart Failure.
To examine the association of race/ethnicity and socioeconomic deprivation with initiation of guideline-recommended diabetes medications with cardiovascular benefit (glucagon-like peptide 1 receptor agonists [GLP1-RA] and sodium-glucose cotransporter 2 inhibitors [SGLT2i]) among older adults with type 2 diabetes (T2D) and either incident atherosclerotic cardiovascular disease (ASCVD) or congestive heart failure (CHF).. Using Medicare data (2016-2019), we identified 4,057,725 individuals age >65 years with T2D and either incident ASCVD or CHF. We estimated incidence rates and hazard ratios (HR) of GLP1-RA or SGLT2i initiation within 180 days by race/ethnicity and zip code-level Social Deprivation Index (SDI) using adjusted Cox proportional hazards models.. Incidence rates of GLP1-RA or SGLT2i initiation increased over time but remained low (<0.6 initiations per 100 person-months) in all years studied. Medication initiation was less common among those of Black or other race/ethnicity (HR 0.81 [95% CI 0.79-0.84] and HR 0.84 [95% CI 0.75-0.95], respectively) and decreased with increasing SDI (HR 0.96 [95% CI 0.96-0.97]). Initiation was higher in ASCVD than CHF (0.35 vs. 0.135 initiations per 100 person-months). Moderate (e.g., nephropathy, nonalcoholic fatty liver disease) but not severe (e.g., advanced chronic kidney disease, cirrhosis) comorbidities were associated with higher probability of medication initiation.. Among older adults with T2D and either ASCVD or CHF, initiation of GLP1-RA or SGLT2i was low, suggesting a substantial deficit in delivery of guideline-recommended care or treatment barriers. Individuals of Black and other race/ethnicity and those with higher area-level socioeconomic deprivation were less likely to initiate these medications. Topics: Aged; Atherosclerosis; Cardiovascular Diseases; Diabetes Mellitus, Type 2; Glucagon-Like Peptide 1; Glucagon-Like Peptide-1 Receptor; Heart Failure; Humans; Hypoglycemic Agents; Medicare; United States | 2023 |
Projecting the incidence and costs of major cardiovascular and kidney complications of type 2 diabetes with widespread SGLT2i and GLP-1 RA use: a cost-effectiveness analysis.
Whether sodium-glucose co-transporter 2 inhibitors (SGLT2is) or glucagon-like peptide-1 receptor agonists (GLP-1 RAs) are cost-effective based solely on their cardiovascular and kidney benefits is unknown. We projected the health and economic outcomes due to myocardial infarction (MI), stroke, heart failure (HF) and end-stage kidney disease (ESKD) among people with type 2 diabetes, with and without CVD, under scenarios of widespread use of these drugs.. We designed a microsimulation model using real-world data that captured CVD and ESKD morbidity and mortality from 2020 to 2040. The populations and transition probabilities were derived by linking the Australian Diabetes Registry (1.1 million people with type 2 diabetes) to hospital admissions databases, the National Death Index and the ESKD Registry using data from 2010 to 2019. We modelled four interventions: increase in use of SGLT2is or GLP-1 RAs to 75% of the total population with type 2 diabetes, and increase in use of SGLT2is or GLP-1 RAs to 75% of the secondary prevention population (i.e. people with type 2 diabetes and prior CVD). All interventions were compared with current use of SGLT2is (20% of the total population) and GLP-1 RAs (5% of the total population). Outcomes of interest included quality-adjusted life years (QALYs), total costs (from the Australian public healthcare perspective) and the incremental cost-effectiveness ratio (ICER). We applied 5% annual discounting for health economic outcomes. The willingness-to-pay threshold was set at AU$28,000 per QALY gained.. The numbers of QALYs gained from 2020 to 2040 with increased SGLT2i and GLP-1 RA use in the total population (n=1.1 million in 2020; n=1.5 million in 2040) were 176,446 and 200,932, respectively, compared with current use. Net cost differences were AU$4.2 billion for SGLT2is and AU$20.2 billion for GLP-1 RAs, and the ICERs were AU$23,717 and AU$100,705 per QALY gained, respectively. In the secondary prevention population, the ICERs were AU$8878 for SGLT2is and AU$79,742 for GLP-1 RAs.. At current prices, use of SGLT2is, but not GLP-1 RAs, would be cost-effective when considering only their cardiovascular and kidney disease benefits for people with type 2 diabetes. Topics: Australia; Cardiovascular Diseases; Cost-Effectiveness Analysis; Diabetes Mellitus, Type 2; Glucagon-Like Peptide 1; Glucagon-Like Peptide-1 Receptor; Heart Failure; Humans; Hypoglycemic Agents; Incidence; Kidney; Sodium-Glucose Transporter 2 Inhibitors | 2023 |
The Effects of Dual GLP-1/Glucagon Receptor Agonists with Different Receptor Selectivity in Mouse Models of Obesity and Nonalcoholic Steatohepatitis.
There is an unmet need for nonalcoholic steatohepatitis (NASH) therapeutics, considering the increase in global obesity. Dual GLP-1/glucagon (GCG) receptor agonists have shown beneficial effects in circumventing the pathophysiology linked to NASH. However, dual GLP-1/GCG receptor agonists as a treatment of metabolic diseases need delicate optimization to maximize metabolism effects. The impacts of increased relative GLP-1/GCG receptor activity in NASH settings must be addressed to unleash the full potential. In this study, we investigated the potential of OXM-104 and OXM-101, two dual GLP-1/GCG receptor agonists with different receptor selectivity in the setting of NASH, to establish the relative receptor activities leading to the best metabolic outcome efficacies to reduce the gap between surgery and pharmacological interventions. We developed dual GLP-1/GCG receptor agonists with selective agonism. Despite the improved metabolic effects of OXM-101, we explored a hyperglycemic risk attached to increased relative GCG receptor agonism. Thirty-eight days of treatment with a dual GLP-1/GCG receptor agonist, OXM-104, with increased GLP-1 receptor agonism in obese NASH mice was found to ameliorate the development of NASH by lowering body weight, improving liver and lipid profiles, reducing the levels of the fibrosis marker PRO-C4, and improving glucose control. Similarly, dual GLP-1/GCG receptor agonist OXM-101 with increased relative GCG receptor agonism ameliorated NASH by eliciting dramatic body weight reductions to OXM-104, reflected in the improvement of liver and lipid enzymes and reduced PRO-C4 levels. Optimizing dual GLP-1/GCG agonists with increased relative GCG receptor agonism can provide the setting for future agonists to treat obesity, type 2 diabetes, and NASH without having a hyperglycemic risk. SIGNIFICANT STATEMENT: There is an unmet need for nonalcoholic steatohepatitis (NASH) therapeutics, considering the increase in global obesity. Dual GLP-1/glucagon (GCG) receptor agonists have shown beneficial effects in circumventing the pathophysiology linked to NASH. Therefore, this study has examined OXM-104 and OXM-101, two dual GLP-1/GCG receptor agonists in the setting of NASH, to establish the relative receptor activities leading to the best metabolic outcome efficacies to reduce the gap between surgery and pharmacological interventions. Topics: Animals; Body Weight; Complement C4; Diabetes Mellitus, Type 2; Disease Models, Animal; Glucagon; Glucagon-Like Peptide 1; Glucagon-Like Peptide-1 Receptor; Lipids; Mice; Non-alcoholic Fatty Liver Disease; Obesity; Receptors, Glucagon | 2023 |
Switching to a fixed-ratio combination of insulin degludec/liraglutide (IDegLira) is associated with improved glycaemic control in a real-world population with type 2 diabetes mellitus in the United Arab Emirates: Results from the multicentre, prospective
Investigate the effectiveness of IDegLira, a fixed-ratio combination of insulin degludec/liraglutide, in a real-world setting in patients with type 2 diabetes mellitus in the United Arab Emirates.. This non-interventional study enrolled adults switching to IDegLira from basal insulin (BI) or glucagon-like peptide-1 receptor agonists (GLP-1 RAs) with/without concomitant oral antidiabetic drugs (OADs). Primary endpoint was change in HbA1c from baseline, assessed using a mixed model for repeated measurements.. Among 263 patients (BI ± OADs, n = 206; GLP-1 RA ± OADs, n = 57), mean baseline HbA1c was 9.29 % (78 mmol/mol). After 26 weeks, HbA1c was significantly reduced (BI ± OADs, -0.83 % [-9.0 mmol/mol] and GLP-1 RA ± OADs, -1.24 % [-13.5 mmol/mol]; both p < 0.0001). Fasting plasma glucose (FPG) was significantly reduced (-39.48 mg/dL [BI ± OADs] and -82.49 mg/dL [GLP-1 RA ± OADs]; both p < 0.0001). Before treatment initiation, 3/263 patients experienced ≥ 1 severe hypoglycaemic episode and 7/263 patients experienced ≥ 1 non-severe hypoglycaemic episode compared with 1/263 patients who had ≥ 1 severe and 1/263 who had ≥ 1 non-severe episode at end of study. Body weight decreased significantly among patients switching from BI ± OADs (-1.05 kg [p < 0.0001]). Treatment was well tolerated.. IDegLira significantly reduced HbA1c and FPG in this real-world setting, along with less frequent episodes of hypoglycaemia. Switching to IDegLira offers effective treatment intensification for type 2 diabetes patients with inadequate glycaemic control. Topics: Adult; Blood Glucose; Diabetes Mellitus, Type 2; Drug Combinations; Glucagon-Like Peptide 1; Glycated Hemoglobin; Glycemic Control; Humans; Hypoglycemia; Hypoglycemic Agents; Liraglutide; Prospective Studies; United Arab Emirates | 2023 |
[In patients with type 2 diabetes on metformin, the addition of which antihyperglycemic class among a sulfonylurea (glimepiride), a DPP-4 inhibitor (sitagliptin), a GLP-1 agonist (liraglutide), or basal insulin (glargine) is the most effective to achieve
Topics: Blood Glucose; Diabetes Mellitus, Type 2; Dipeptidyl-Peptidase IV Inhibitors; Drug Therapy, Combination; Glucagon-Like Peptide 1; Glycemic Control; Humans; Hypoglycemic Agents; Insulin; Insulin Glargine; Liraglutide; Metformin; Sitagliptin Phosphate; Treatment Outcome | 2023 |
Glucagon-like peptide-1 therapy for youth with type 2 diabetes.
Topics: Adolescent; Blood Glucose; Diabetes Mellitus, Type 2; Glucagon-Like Peptide 1; Glucagon-Like Peptide-1 Receptor; Humans; Hypoglycemic Agents; Insulin; Peptide Fragments | 2023 |
Altered chronic glycemic control in a clinically relevant model of rat thoracic spinal contusion.
The lifetime risk for Type 2 diabetes mellitus remains higher in people with spinal cord injuries (SCIs) than in the able-bodied population. However, the mechanisms driving this disparity remain poorly understood. The goal of the present study was to evaluate the impact of a palatable high-fat diet (HFD) on glycemic regulation using a rodent model of moderate thoracic contusion. Animals were placed on either Chow or HFD and tolerance to glucose, insulin, and ENSURE mixed meal were investigated. Important targets in the gut-brain axis were investigated. HFD consumption equally induced weight gain in SCI and naïve rats over chow (CH) rats. Elevated blood glucose was observed during intraperitoneal glucose tolerance test in HFD-fed rats over CH-fed rats. Insulin tolerance test (ITT) was unremarkable among the three groups. Gavage of ENSURE resulted in high glucagon-like peptide 1 (GLP-1) release from SCI rats over naïve controls. An elevation in terminal total GLP-1 was measured, with a marked reduction in circulating dipeptidyl peptidase 4, the GLP-1 cleaving enzyme, in SCI rats, compared with naïve. Increased glucagon mRNA in the pancreas and reduced immunoreactive glucagon-positive staining in the pancreas in SCI rats compared with controls suggested increased glucagon turnover. Finally, GLP-1 receptor gene expression in the ileum, the primary source of GLP-1 production and release, in SCI rats suggests the responsivity of the gut to altered circulating GLP-1 in the body. In conclusion, the actions of GLP-1 and its preprohormone, glucagon, are markedly uncoupled from their actions on glucose control in the SCI rat. More work is required to understand GLP-1 in the human. Topics: Animals; Blood Glucose; Diabetes Mellitus, Type 2; Glucagon; Glucagon-Like Peptide 1; Glycemic Control; Humans; Insulin; Rats | 2023 |
Beta-cell mass adaptation to ileum nutrient flow. An experimental model.
The population with obesity has increased at an alarming rate during this century. Bariatric surgery has been demonstrated to be a good method to control weight and, most importantly, associated comorbidities, such as type 2 diabetes mellitus or high blood pressure. The reason why this happens even before losing significant weight remains unclear. Many authors believe that incretins play a main role, triggering special functions of the digestive tract. In reports, these hypotheses are known as foregut and hindgut theories. Initially, the theories were mutually exclusive; additionally, many other propositions have been analysed, according to different surgical techniques (e.g., bile acids and specific enterohormonal components). To elucidate the participation of the ileum, we developed a surgical technique to study the rapid response to nutrients in the ileum. Our goal was to study the stress functional test and histological changes in the pancreas that may explain the variations in glycaemic homeostasis in our rat model. After the oral glucose tolerance test, the experimental group presented an increased insulin release response with conserved glycaemia. We report an increasing beta-cell mass in the experimental group (+11.87 mg vs. +9.65 mg, respectively), while alpha-cell mass was not different. Based on transcription factors, the pathways that were increased were the proliferation process (as the number of PCNA-positive cells in the experimental group versus sham (+12.06 vs. +6.2 PCNA+ cells/mm²)) and transdifferentiation (ARX; +2.67 ARX+ cells/mm² in the experimental group vs. +2.04 ARX+ cells/mm² in the controls). We report the consequences of the rapid arrival of nonprocessed nutrients to the ileum on the endocrine cellular pancreas. The ileum could be a principal effector in the enterohormonal axis, which conditions endocrine pancreas cellularity. Topics: Animals; Blood Glucose; Diabetes Mellitus, Type 2; Glucagon-Like Peptide 1; Ileum; Models, Theoretical; Proliferating Cell Nuclear Antigen; Rats | 2023 |
Tirzepatide versus semaglutide for weight loss in patients with type 2 diabetes mellitus: A value for money analysis.
Higher doses of the glucagon-like peptide-1 agonist semaglutide and, more recently, tirzepatide, a dual glucose-dependent insulinotropic polypeptide and glucagon-like peptide-1 agonist showed a significant reduction in body weight in patients with type 2 diabetes mellitus. However, their comparative value for money for this indication is unclear. Therefore, we aimed to establish which provides better value for money.. We calculated the cost needed to treat to achieve a 1% reduction in body weight using high-dose tirzepatide (15 mg) versus semaglutide (2.4 mg). The body weight reductions were extracted from published results of SURMOUNT-1 and STEP 1 trials, respectively. In addition, we performed a scenario analysis to mitigate the primary differences between the two study populations. Drug costs were based on US GoodRx prices as of October 2022.. Using tirzepatide resulted in a weight loss of 17.8% (95% CI: 16.3%-19.3%) compared with 12.4% (95% CI: 11.5%-13.4%) for semaglutide. The total cost of 72 weeks of tirzepatide was estimated at $17 527 compared with $22 878 for 68 weeks of semaglutide. Accordingly, the cost needed to treat per 1% of body weight reduction with tirzepatide is estimated at $985 (95% CI: $908-$1075) compared with $1845 (95% CI: $1707-$1989) with semaglutide. Scenario analysis confirmed these findings.. Tirzepatide provides better value for money than semaglutide for weight reduction. Topics: Body Weight; Diabetes Mellitus, Type 2; Glucagon-Like Peptide 1; Glucagon-Like Peptide-1 Receptor; Glucagon-Like Peptides; Glycated Hemoglobin; Humans; Hypoglycemic Agents; Weight Loss | 2023 |
Putting GLP-1 RAs and Thyroid Cancer in Context: Additional Evidence and Remaining Doubts.
Topics: Diabetes Mellitus, Type 2; Glucagon-Like Peptide 1; Glucagon-Like Peptide-1 Receptor; Humans; Hypoglycemic Agents; Thyroid Neoplasms | 2023 |
The GLP-1 receptor agonist exenatide ameliorates neuroinflammation, locomotor activity, and anxiety-like behavior in mice with diet-induced obesity through the modulation of microglial M2 polarization and downregulation of SR-A4.
Obesity is associated with multiple comorbidities, such as metabolic abnormalities and cognitive dysfunction. Moreover, accumulating evidence indicates that neurodegenerative disorders are associated with chronic neuroinflammation. GLP-1 receptor agonists (RAs) have been extensively studied as a treatment for type 2 diabetes. Emerging evidence has demonstrated a protective effect of GLP-1 RAs on neurodegenerative disease, which is independent of its glucose-lowering effects. In this study, we aimed to examine the effects of a long-acting GLP-1 RA, exenatide, on high-fat diet (HFD)-induced neuroinflammation and related brain function impairment. First, mice treated with exenatide exhibited significantly reduced HFD-increased body weight and blood glucose. In an open field test, exenatide treatment ameliorated the reduction in local motor activity and anxiety in HFD-fed mice. Moreover, HFD induced astrogliosis, microgliosis, and upregulation of IL-1β, IL-6 and TNF-α in hippocampus and cortex. Exenatide treatment reduced HFD-induced astrogliosis and IL-1β and TNF-α expressions. Moreover, exenatide increased phosphor-ERK and M2-type microglia marker arginase-1 expression in the hippocampus and cortex. In addition, we found that scavenger receptor-A4 protein expression was induced by HFD and was subsequently inhibited by exenatide. SR-A4 knockout reversed the locomotor activity impairment but not the anxiety behavior caused by HFD consumption. SR-A4 knockout also reduced HFD-induced neuroinflammation, as shown by the reduced expression of GFAP and IBA-1 compared with that in wild-type control mice. These results demonstrate that exenatide decreases HFD-increased neuroinflammation and promotes anti-inflammatory M2 differentiation. The inhibition of SR-A4 by exenatide exerts anti-inflammatory activity. Topics: Animals; Anxiety; Diabetes Mellitus, Type 2; Diet, High-Fat; Down-Regulation; Exenatide; Gliosis; Glucagon-Like Peptide 1; Glucagon-Like Peptide-1 Receptor; Locomotion; Mice; Mice, Inbred C57BL; Microglia; Neurodegenerative Diseases; Neuroinflammatory Diseases; Obesity; Tumor Necrosis Factor-alpha | 2023 |
Egg Microneedle for Transdermal Delivery of Active Liraglutide.
Liraglutide, a human glucagon-like peptide-1 (GLP-1) analog, is promising for safely treating type 2 diabetes mellitus (T2DM), compared to insulin, by significantly reducing the risk of glucose-dependent hypoglycemia. Concerns related to injection prevent T2DM patients from taking liraglutide regularly, even though once-a-day subcutaneous (SC) injections. Dissolving microneedles (DMNs) are promising substitutes for SC injection and for improving patient convenience. However, there are two fundamental limitations: the low drug delivery due to incomplete insertion and loss of drug activity during DMN fabrication. Here, it is shown that an egg microneedle (EMN) designed with three functional layered structures can maintain the maximum activity of the loaded compound during DMN fabrication and deliver it completely into the skin, with the base layer allowing the complete delivery of liraglutide, and the shell layer maintaining the drug activity by mimicking the role of albumin in eggs. In a diabetic mouse model, liraglutide administration via EMN exhibited similar effect when compared to that of injection. Therefore, EMN-mediated liraglutide administration is a good potential option for replacing liraglutide injections in T2DM treatment. Topics: Administration, Cutaneous; Animals; Diabetes Mellitus, Type 2; Glucagon-Like Peptide 1; Humans; Liraglutide; Mice; Skin | 2023 |
Real-world weight-loss effectiveness of glucagon-like peptide-1 agonists among patients with type 2 diabetes: A retrospective cohort study.
Weight loss achieved with standard doses of glucagon-like peptide-1 (GLP-1) agonists among real-world patients with type 2 diabetes has not been determined. This study sought to describe the percent change in body weight 72 weeks after starting a GLP-1 agonist.. A retrospective cohort study of nonpregnant adults who were first dispensed a GLP-1 agonist between 2011 and 2018 was conducted using electronic health record data from patients receiving care at a large health system. Linear mixed models were used, with a person-level random intercept controlling for baseline variables associated with missing weight data to estimate percent body weight change during follow-up.. The cohort included 2405 patients (mean [SD] age 48 [10] years, 53% female), with a mean BMI of 37 (8) kg/m. In this real-world study of more than 2400 patients with overweight or obesity and type 2 diabetes, starting a GLP-1 agonist at standard glycemic control doses was associated with modest weight loss through 72 weeks. Topics: Adult; Body Weight; Diabetes Mellitus, Type 2; Female; Glucagon-Like Peptide 1; Glucagon-Like Peptide-1 Receptor; Glycated Hemoglobin; Humans; Hypoglycemic Agents; Male; Middle Aged; Retrospective Studies; Weight Loss | 2023 |
The 'early' postprandial glucagon response is related to the rate of gastric emptying in type 2 diabetes.
Gastric emptying (GE) is a major determinant of the postprandial glycemic and insulinemic responses in health and type 2 diabetes (T2D). However, the effect of GE on the postprandial glucagon response, which is characteristically augmented in T2D, is unknown. This study examined the relationship between plasma glucagon and GE of a standardized mixed meal in individuals with well-controlled T2D. 89 individuals with T2D (HbA1c 6.6 ± 0.1%) consumed a mashed potato meal labeled with 100 µL Topics: Blood Glucose; Diabetes Mellitus, Type 2; Gastric Emptying; Glucagon; Glucagon-Like Peptide 1; Humans; Insulin; Postprandial Period | 2023 |
[A new era for glucagon-like peptide-1 receptor agonists].
Glucagon-like peptide-1 (GLP-1) receptor agonists have a privileged place in the management of type 2 diabetes (T2D). They not only improve glucose control without inducing hypoglycaemia and trigger weight loss, but also protect against atherosclerotic cardiovascular disease. Increasing the dose of three of them (liraglutide, semaglutide, dulaglutide) allows better glycaemic results and of potential interest a greater weight reduction. Liraglutide at a daily dose of 3.0 mg and semaglutide at a weekly dose of 2.4 mg received the indication for the therapy of obesity. A recent innovation consists in the development of dual unimolecular agonists that target GLP-1 and GIP («glucose-dependent insulinotropic polypeptide») receptors (tirzepatide) or GLP-1 and glucagon receptors (cotadutide). Tirzepatide, in the SURPASS programme, showed impressive reductions in glycated haemoglobin level and body weight, greater than those observed with dulaglutide or semaglutide. Tirzepatide received the indication of the treatment of T2D and is currently tested in obesity (SURMOUNT programme). Interestingly, triagonists GIP/GLP-1/glucagon are currently developed for the management of T2D and obesity, with also perspectives for treating metabolic-associated fatty liver disease.. Les agonistes du glucagon-like peptide-1 (GLP-1) ont une place de choix dans la prise en charge des patients avec un diabète de type 2 (DT2). Non seulement ils améliorent le contrôle glycémique sans provoquer des hypoglycémies et font perdre du poids, mais ils protègent également contre les maladies cardiovasculaires athéromateuses. Une augmentation de la posologie de trois d’entre eux (liraglutide, sémaglutide, dulaglutide) a permis de meilleurs résultats glycémiques et surtout une plus grande perte pondérale. Le liraglutide, à la dose de 3,0 mg/jour, et le sémaglutide, à la dose de 2,4 mg/semaine, ont d’ailleurs reçu l’indication pour le traitement de l’obésité. Une innovation récente consiste dans le développement d’agonistes unimoléculaires doubles ciblant les récepteurs du GLP-1 et du GIP («glucose-dependent insulinotropic polypeptide») (tirzépatide) ou les récepteurs du GLP-1 et du glucagon (cotadutide). Le tirzépatide, dans le programme SURPASS, a montré des réductions importantes du taux d’hémoglobine glyquée et du poids corporel, supérieures à celles observées avec le dulaglutide ou le sémaglutide. Il a reçu l’indication du traitement du DT2 et est actuellement testé dans l’obésité (programme SURMOUNT). Des triagonistes GIP/GLP-1/glucagon sont également développés pour le traitement du DT2 et de l’obésité, avec des perspectives également dans la stéatopathie hépatique. Topics: Diabetes Mellitus, Type 2; Glucagon-Like Peptide 1; Glucagon-Like Peptide-1 Receptor; Glucagon-Like Peptides; Humans; Hypoglycemic Agents; Liraglutide; Obesity; Weight Loss | 2023 |
Glucagon-like peptide 1 therapy as an adjunct treatment after bariatric metabolic surgery: Preliminary experience from an East-Asian medical center.
Topics: Bariatric Surgery; Diabetes Mellitus, Type 2; Glucagon-Like Peptide 1; Humans | 2023 |
Benefits of GLP-1 Mimetics on Epicardial Adiposity.
The epicardial adipose tissue, which is referred to as fats surrounding the myocardium, is an active organ able to induce cardiovascular problems in pathophysiologic conditions through several pathways, such as inflammation, fibrosis, fat infiltration, and electrophysiologic problems. So, control of its volume and thickness, especially in patients with diabetes, is highly important. Incretin-based pharmacologic agents are newly developed antidiabetics that could provide further cardiovascular benefits through control and modulating epicardial adiposity. They can reduce cardiovascular risks by rapidly reducing epicardial adipose tissues, improving cardiac efficiency. We are at the first steps of a long way, but current evidence demonstrates the sum of possible mechanisms. In this study, we evaluate epicardial adiposity in physiologic and pathologic states and the impact of incretin-based drugs. Topics: Adiposity; Diabetes Mellitus, Type 2; Dipeptidyl-Peptidase IV Inhibitors; Glucagon-Like Peptide 1; Humans; Hypoglycemic Agents; Incretins; Obesity; Pericardium | 2023 |
Discovery of novel OXM-based glucagon-like peptide 1 (GLP-1)/glucagon receptor dual agonists.
Novel glucagon receptor (GCGR) and glucagon-like peptide 1 receptor (GLP-1R) dual agonists are reported to have improved efficacy over GLP-1R mono-agonists in treating type 2 diabetes (T2DM) and obesity. Here, we describe the discovery of a novel oxyntomodulin (OXM) based GLP-1R/GCGR dual agonist with potent and balanced potency toward GLP-1R and GCGR. The lead peptide OXM-7 was obtained via stepwise rational design and long-acting modification. In ICR and db/db mice, OXM-7 exhibited prominent acute and long-acting hypoglycemic effects. In diet-induced obesity (DIO) mice, twice-daily administration of OXM-7 produced significant weight loss, normalized lipid metabolism, and improved glucose control. In DIO-nonalcoholic steatohepatitis (NASH) mice, OXM-7 treatment significantly reversed hepatic steatosis, and reduced serum and hepatic lipid levels. These preclinical data suggest the therapeutic potential of OXM-7 as a novel anti-diabetic, anti-steatotic and/or anti-obesity agent. Topics: Animals; Diabetes Mellitus, Type 2; Glucagon-Like Peptide 1; Glucagon-Like Peptide-1 Receptor; Mice; Mice, Inbred ICR; Obesity; Oxyntomodulin; Receptors, Glucagon | 2023 |
Does glucose lowering restore GIP effects on insulin secretion?
Some studies have shown that in type 2 diabetic patients the potentiation of insulin secretion by glucose-dependent insulinotropic polypeptide (GIP) is compromised but can be partially restored if glucose is lowered. Renewed interest for this phenomenon has been expressed in the context of the new dual GIP-GLP-1 (glucagon-like peptide-1) receptor agonists, which have shown greater efficacy of this drug class compared with single GLP-1 receptor agonists, including on insulin secretion. However, contrasting evidence has been reported on the recovery of GIP action with glucose lowering. In our study, we reconsider all publications relevant for the problem and analyze the results using a uniform methodology.. We show that, while some contradictions might be explained by heterogeneous analysis methods, it is possible to interpret all the available data coherently and conclude that the effect of glucose lowering is relevant only when glucose concentration is virtually normalized.. While a significant restoration of GIP action may not occur with some traditional diabetes treatments, GIP action improvement might become relevant when glucose is virtually normalized and could explain part of the success of the double GIP-GLP-1 receptor agonists. Topics: Blood Glucose; Diabetes Mellitus, Type 2; Gastric Inhibitory Polypeptide; Glucagon-Like Peptide 1; Glucagon-Like Peptide-1 Receptor; Glucose; Humans; Insulin; Insulin Secretion | 2023 |
Glucagon-like peptide-1 receptor agonists and diabetic retinopathy: nationwide cohort and Mendelian randomization studies.
The ability of glucagon-like peptide-1 receptor agonists (GLP-1 RAs) to decrease certain microvascular events has called for the investigation of GLP-1 RAs against diabetic retinopathy (DR), but the evidence is limited. By combining data from observational and Mendelian randomization (MR) studies, we aimed to investigate whether GLP-1 RAs decrease the risk of DR.. We combined data from several Swedish Registers and identified patients with incident type 2 diabetes being treated with GLP-1 RAs between 2006 and 2015, and matched them to diabetic patients who did not use GLP-1 RAs as the comparisons. The Cox proportional hazards models were applied to assess the risk of DR. We further performed the summary-data-based MR (SMR) analyses based on the Genotype-Tissue Expression databases and the Genome-Wide Association Study of DR from the FinnGen consortium.. A total of 2390 diabetic patients were treated with GLP-1 RAs and the incidence of DR was 5.97 per 1000 person-years. Compared with diabetic patients who did not use GLP-1 RAs having an incidence of 12.85 per 1000 person-years, the adjusted hazard ratio (HR) of DR was 0.42 [95% confidence interval (CI), 0.29-0.61]. Genetically-predicted GLP1R expression (the target of GLP-1 RAs) showed an inverse association with background [odds ratio (OR)=0.83, 95% CI, 0.71-0.97] and severe nonproliferative DR (OR=0.72, 95% CI, 0.53-0.98), and a non-significant association with overall (OR=0.97, 95% CI, 0.92-1.03) and proliferative DR (OR=0.98, 95% CI, 0.91-1.05).. Both observational and mendelian randomization analyses showed a significantly lower risk of DR for patients treated with GLP-1 RAs, which calls for further studies to validate these findings. Topics: Diabetes Mellitus, Type 2; Diabetic Retinopathy; Genome-Wide Association Study; Glucagon-Like Peptide 1; Glucagon-Like Peptide-1 Receptor; Humans; Hypoglycemic Agents; Mendelian Randomization Analysis | 2023 |
Glucagon-Like Peptide 1 Therapy: From Discovery to Type 2 Diabetes and Beyond.
The therapeutic benefits of the incretin hormone, glucagon-like peptide 1 (GLP1), for people with type 2 diabetes and/or obesity, are now firmly established. The evidence-base arising from head-to-head comparative effectiveness studies in people with type 2 diabetes, as well as the recommendations by professional guidelines suggest that GLP1 receptor agonists should replace more traditional treatment options such as sulfonylureas and dipeptidyl-peptidase 4 (DPP4) inhibitors. Furthermore, their benefits in reducing cardiovascular events in people with type 2 diabetes beyond improvements in glycaemic control has led to numerous clinical trials seeking to translate this benefit beyond type 2 diabetes. Following early trial results their therapeutic benefit is currently being tested in other conditions including fatty liver disease, kidney disease, and Alzheimer's disease. Topics: Diabetes Mellitus, Type 2; Dipeptidyl-Peptidase IV Inhibitors; Glucagon-Like Peptide 1; Humans; Hypoglycemic Agents; Kidney Diseases | 2023 |
Impact of chronic GLP-1 RA and SGLT-2I therapy on in-hospital outcome of diabetic patients with acute myocardial infarction.
Glucagon-like peptide-1 receptor agonists (GLP-1 RA) and sodium glucose cotransporter-2 inhibitors (SGLT-2i) demonstrated cardiovascular and renal protection. Whether their benefits occur also during hospitalization for acute myocardial infarction (AMI) in patients with diabetes mellitus (DM) is not known. We evaluated in-hospital outcomes of patients hospitalized with AMI according to their chronic use of GLP-1 RA and/or SGLT-2i.. Using the health administrative databases of Lombardy, patients hospitalized with AMI from 2010 to 2019 were included. They were stratified according to DM status, then grouped into three cohorts using a propensity score matching: non-DM patients; DM patients treated with GLP-1 RA and/or SGLT-2i; DM patients not treated with GLP-1 RA/SGLT-2i. The primary endpoint of the study was the composite of in-hospital mortality, acute heart failure, and acute kidney injury requiring renal replacement therapy.. We identified 146,798 patients hospitalized with AMI (mean age 71 ± 13 years, 34% females, 47% STEMI; 26% with DM). After matching, 3,090 AMI patients (1030 in each group) were included in the analysis. Overall, the primary endpoint rate was 16% (n = 502) and progressively increased from non-DM patients to DM patients treated with and without GLP-1 RA/SGLT-2i (13%, 16%, and 20%, respectively; P < 0.0001). Compared with non-DM patients, DM patients with GLP-1 RA/SGLT-2i had a 30% higher risk of the primary endpoint, while those not treated with GLP-1 RA/SGLT-2i had a 60% higher risk (P < 0.0001).. Chronic therapy with GLP-1 RA and/or SGLT-2i has a favorable impact on the clinical outcome of DM patients hospitalized with AMI. Topics: Aged; Aged, 80 and over; Diabetes Mellitus, Type 2; Female; Glucagon-Like Peptide 1; Glucagon-Like Peptide-1 Receptor; Hospitals; Humans; Hypoglycemic Agents; Male; Middle Aged; Myocardial Infarction; Risk Factors; Sodium-Glucose Transporter 2 Inhibitors | 2023 |
Basal Insulin/GLP-1 RA Fixed-Ratio Combinations as an Option for Advancement of Basal Insulin Therapy in Older Adults With Type 2 Diabetes.
The prevalence of type 2 diabetes (T2D) is increasing, and owing to the aging population, the number of older adults with T2D is growing rapidly. By virtue of their age, older adults are likely to have been living with the disease longer than their younger counterparts. This, coupled with differences in T2D pathophysiology between younger and older patients, means that older adults often require advancement of treatment from basal insulin. However, older adults with T2D represent a heterogeneous population, for whom the goals of treatment are complex, and overtreatment can increase the risk of complications. These factors highlight the need for individualized glycemic targets and therapeutic strategies. In this roundtable, the authors discuss the management of older adults with T2D--a large patient population who often require treatment simplification. Topics: Aged; Diabetes Mellitus, Type 2; Glucagon-Like Peptide 1; Glucagon-Like Peptide-1 Receptor; Humans; Hypoglycemic Agents; Insulin | 2023 |
New Drug: Tirzepatide (Mounjaro
Type 2 diabetes mellitus (T2DM) is the most common form of diabetes and is a chronic and progressive illness. Millions of Americans have T2DM and many patients do not achieve the recommended blood glucose levels. Glucagon-like peptide 1 (GLP-1) based therapy is an established treatment for the management of T2DM and is recommended early in the treatment algorithm. GLP-1 therapy is associated with better glycemic control, weight reduction, and favorable cardiovascular outcomes. Tirzepatide (Mounjaro™) is a novel dual glucose-dependent insulinotropic polypeptide (GIP) receptor and GLP-1 receptor agonist. Evidence from five SURPASS clinical trials has demonstrated that tirzepatide has potent glucose lowering and weight loss with adverse effects comparable to GLP-1 receptor agonists. This paper gives an overview of tirzepatide and SURPASS clinical trials. Topics: Diabetes Mellitus, Type 2; Glucagon-Like Peptide 1; Glucagon-Like Peptide-1 Receptor; Glucose; Humans; Weight Loss | 2023 |
Glucagon-like peptide-1 agonists combined with sodium-glucose cotransporter-2 inhibitors reduce weight in type 1 diabetes.
This study evaluated whether adding sodium-glucose cotransporter-2 inhibitors (SGLT2i) and/or glucagon-like peptide-1 receptor agonists (GLP1-RA) to insulin reduced weight and glycemia in people with type 1 diabetes.. This retrospective analysis of electronic health records evaluated 296 people with type 1 diabetes over 12 months after medications were first prescribed. Four groups were defined: control n = 80, SGLT2i n = 94, GLP1-RA n = 82, and combination of drugs (Combo) n = 40. We measured changes at 1 year in weight and glycated hemoglobin (HbA1c).. The control group did not have changes in weight or glycemic control. The mean (SD) percentage weight loss after 12 months was 4.4% (6.0%), 8.2% (8.5%), and 9.0% (8.4%) in the SGLT2i, GLP1-RA, and Combo groups, respectively (p < 0.001). The Combo group lost the most weight (p < 0.001). The HbA1c reduction was 0.4% (0.7%), 0.3% (0.7%), and 0.6% (0.8%) in the SGLT2i, GLP1-RA, and Combo groups, respectively (p < 0.001). The Combo group had the biggest improvements in glycemic control and total and low-density lipoprotein cholesterol compared with baseline (all p < 0.01). Severe adverse events were similar between all the groups, with no increased risk of diabetic ketoacidosis.. The SGLT2i and GLP1-RA agents on their own improved body weight and glycemia, but combining the medications resulted in more weight loss. Treatment intensification appears to result in benefits with no difference in severe adverse events. Topics: Diabetes Mellitus, Type 1; Diabetes Mellitus, Type 2; Glucagon-Like Peptide 1; Glucagon-Like Peptide-1 Receptor; Glucose; Glycated Hemoglobin; Humans; Hypoglycemic Agents; Retrospective Studies; Sodium; Sodium-Glucose Transporter 2 Inhibitors; Weight Loss | 2023 |
Comparative cardiovascular effects of GLP-1 agonists using real-world data.
There is limited research using real-world data to evaluate protective cardiovascular effects of glucagon-like peptide-1 (GLP-1) agonists among adults with type 2 diabetes (T2D) early in treatment.. We conducted a retrospective, active comparator cohort study using 2011-2015 administrative claims data to compare cardiovascular disease (CVD) event rates following initiation of exenatide extended-release (E-ER), exenatide immediate-release (E-IR) or liraglutide in T2D adults who previously received no other antidiabetic medication (ADM) except metformin. The primary outcome was time to first major adverse CVD event (ischaemic heart disease, stroke, congestive heart failure or peripheral arterial disease) after starting GLP-1. Cox proportional hazards regression was used to model the association between index GLP-1 and CVD events, adjusting for baseline patient, prescriber and plan characteristics. Primary analyses included all patients with ≥2 prescription fills for the index GLP-1, regardless of subsequent refill adherence or initiation of other ADM after index date.. Compared with liraglutide, neither E-ER nor E-IR was associated with risk of composite major CVD events (hazard ratios [HRs] for E-ER and E-IR: 1.33 [95% C.I. 0.73-2.39] and 1.30 [0.81-2.09]). No associations were observed between event rates for individual CVD components. The HR for an ischaemic event with E-IR relative to liraglutide was 1.85 (95% C.I. 0.97-3.53). Adjusting for time-varying exposure to other ADM and CVD medications after index date produced similar results.. Initiating either immediate or extended-release exenatide rather than liraglutide was not associated with significant differences in CVD risk in this observational real-world study. Topics: Adult; Cardiovascular Diseases; Cohort Studies; Diabetes Mellitus, Type 2; Exenatide; Glucagon-Like Peptide 1; Humans; Hypoglycemic Agents; Liraglutide; Retrospective Studies | 2023 |
Risks of stroke, its subtypes and atrial fibrillation associated with glucagon-like peptide 1 receptor agonists versus sodium-glucose cotransporter 2 inhibitors: a real-world population-based cohort study in Hong Kong.
There are limited data on head-to-head comparative risk of stroke between sodium-glucose cotransporter 2 inhibitors (SGLT2i) and glucagon-like peptide-1 receptor agonists (GLP-1RA). We compared risk of stroke with its subtypes and incident atrial fibrillation (AF) between them.. A population-based, retrospective cohort of patients with type 2 diabetes between 2008 and 2020 were identified from the electronic health records of Hong Kong Hospital Authority. Patients who received SGLT2i or GLP-1RA were matched pairwise by propensity score. Risks of stroke and AF were evaluated by hazard ratios (HRs) from the Cox proportional hazard regression models.. A total of 5840 patients (2920 SGLT2i users; 2920 GLP-1RA users) were included (mean age 55.5 years, 56.1% men, mean HbA1c 8.9% and duration of diabetes 13.7 years). Upon median follow-up of 17 months, there were 111 (1.9%) events of stroke (SGLT2i: 62, 2.1%; GLP-1RA: 49 1.7%). SGLT2i users had comparable risk of all stroke as GLP-1RA users (HR 1.46, 95% CI 0.99-2.17, p = 0.058). SGLT2i users had higher risk of ischemic stroke (HR 1.53, 95% CI 1.01-2.33, p = 0.044) but similar risk of hemorrhagic stroke compared to GLP-1RA users. Although SGLT2i was associated with lower risk of incident AF (HR 0.43, 95% CI 0.23-0.79, p = 0.006), risk of cardioembolic stroke was similar.. Our real-world study demonstrated that GLP-1RA use was associated with lower risk of ischemic stroke, despite the association between SGLT2i use and lower risk of incident AF. There was no significant difference in hemorrhagic stroke risk. GLP-1RA may be the preferred agent for patients with type 2 diabetes at risk of ischemic stroke. Topics: Atrial Fibrillation; Cohort Studies; Diabetes Mellitus, Type 2; Female; Glucagon-Like Peptide 1; Glucagon-Like Peptide-1 Receptor; Glucose; Hemorrhagic Stroke; Hong Kong; Humans; Hypoglycemic Agents; Ischemic Stroke; Male; Middle Aged; Retrospective Studies; Sodium; Sodium-Glucose Transporter 2 Inhibitors | 2023 |
Telehealth Intervention to Improve Uptake of Evidence-Based Medications among Patients with Type 2 Diabetes and Heart Failure or Cardiovascular Disease.
Sodium glucose cotransporter-2 (SGLT-2) inhibitors and glucagon-like peptide 1 receptor (GLP-1) agonists are recommended for patients with type two diabetes (T2D) and atherosclerotic cardiovascular disease (ASCVD) or heart failure (HF) to reduce cardiovascular-related mortality. The objective of this study was to evaluate a telehealth targeted medication review (TMR) program to identify patients for uptake of these evidence-based medications.. This was an observational descriptive study of a TMR program for Medicare-enrolled, Medication Therapy Management-eligible patients in one insurance plan. Prescription claims and patient interviews identified individuals who would benefit from SGLT-2 inhibitors or GLP-1 agonists. Facsimiles were sent to providers of patients with educational information about the targeted medications. Descriptive statistics described characteristics and proportion of patients prescribed targeted medications after 120 days. Bivariate statistical tests evaluated associations between age, sex, number of medications, number of providers, and poverty level with adoption of targeted medications.. A total of 1106 of 1127 had a facsimile sent to their provider after a conversation with the patient. Among patients with a provider facsimile, 69 (6%) patients filled a prescription for a targeted medication after 120 days. There was a significant difference in age between individuals who started a targeted medication (67 ± 10 years) compared with patients who did not (71 ± 10 years) (. A TMR efficiently identified patients with T2D and ASCVD or HF who would benefit from evidence-based medications. Although younger patients were more likely to receive these medications, the overall uptake of these medications within four months of the intervention was lower than expected. Topics: Aged; Aged, 80 and over; Atherosclerosis; Cardiovascular Diseases; Diabetes Mellitus, Type 2; Glucagon-Like Peptide 1; Heart Failure; Humans; Hypoglycemic Agents; Medicare; Middle Aged; Telemedicine; United States | 2023 |
The GLP-1 receptor agonist exenatide reduces serum TSH by its effect on body weight in people with type 2 diabetes.
Glucagon-like peptide-1 receptor agonist (GLP-1 RA) therapy in patients with type 2 diabetes and obesity leads to a significant reduction in serum thyrotropin (TSH) levels but it is unclear whether this is related to weight loss and improvement in sensitivity to thyroid hormones (TH).. We prospectively analysed clinical and biochemical data in patients with type 2 diabetes and obesity who were commenced on the GLP-1 RA exenatide and followed them for 12 months. We assessed the relationship between changes in body weight and serum TSH and resistance to TH indices.. Exenatide therapy reduces serum TSH levels and improves central sensitivity to TH action over 12 months via its effect on weight loss. The effectiveness of weight loss strategies, rather than TH replacement, should be investigated in individuals with obesity and mildly raised serum TSH levels. Topics: Body Weight; Diabetes Mellitus, Type 2; Exenatide; Female; Glucagon-Like Peptide 1; Glucagon-Like Peptide-1 Receptor; Humans; Male; Middle Aged; Obesity; Thyroid Hormones; Thyrotropin; Weight Loss | 2023 |
Clinical characteristics, treatment patterns, and persistence in individuals with type 2 diabetes initiating a glucagon-like peptide-1 receptor agonist: A retrospective analysis of the Diabetes Prospective Follow-Up Registry.
To describe clinical characteristics, treatment patterns and glucagon-like peptide-1 receptor agonist (GLP-1 RA) persistence in individuals with type 2 diabetes (T2D) initiating their first GLP-1 RA.. A real-world analysis of adults with T2D initiating GLP-1 RA therapy between 2007 and June 2020 from the multicentre Diabetes Prospective Follow-Up (DPV) Registry, stratified by antidiabetes therapy at the time of GLP-1 RA initiation: oral antidiabetic drugs (OAD), insulin ± OAD or lifestyle modification (LM). GLP-1 RA treatment persistence in individuals with ≥12 months follow-up was determined by Kaplan-Meier analysis.. Overall, 15 111 individuals with T2D initiating GLP-1 RA therapy (55% men) were identified; median [interquartile range (IQR)] age [58.7 (50.6-66.7) years], diabetes duration [8.5 (3.6-14.7) years], glycated haemoglobin [HbA1c; 8.2 (7.1-9.8)%]. Median (95% confidence interval) GLP-1 RA persistence in eligible individuals (n = 5189) was 11 (10-12) months; OAD 12 (11-14) months (n = 2453); insulin ± OAD 11 (9-12) months (n = 2204); and LM 7 (5-9) months (n = 532). Median treatment persistence tended to increase from 2007-2012 to 2017-2020. Median (IQR) HbA1c decreased from baseline [8.2 (7.1-9.8)%] to discontinuation [7.5 (6.6-8.7)%], with a greater decrease observed in individuals with persistence >12 months versus ≤12 months. Individuals who discontinued GLP-1 RA therapy predominantly switched to insulin (if not already using) or dipeptidyl peptidase-4 inhibitors.. Real-world registry data revealed improved outcomes with longer median GLP-1 RA persistence; ~50% of patients overall achieved HbA1c <7% at 12 months. Persistence was highest with baseline OAD and/or insulin, and tended to increase over the period 2007-2020. Topics: Adult; Aged; Diabetes Mellitus, Type 2; Female; Follow-Up Studies; Glucagon-Like Peptide 1; Glucagon-Like Peptide-1 Receptor; Glycated Hemoglobin; Humans; Hypoglycemic Agents; Insulin; Insulin, Regular, Human; Male; Middle Aged; Prospective Studies; Retrospective Studies | 2023 |
Implication of sugar, protein and incretins in excessive glucagon secretion in type 2 diabetes after mixed meals.
Amino acids powerfully release glucagon but their contribution to postprandial hyperglucagonemia in type 2 diabetes remains unclear. Exogenously applied GIP stimulates, while GLP-1 inhibits, glucagon secretion in humans. However, their role in mixed meals is unclear, which we therefore characterized.. In three experiments, participants with type 2 diabetes and obese controls randomly received different loads of sugars and/or proteins. In the first experiment, participants ingested the rapidly cleaved saccharose (SAC) or slowly cleaved isomaltulose (ISO) which is known to elicit opposite profiles of GIP and GLP-1 secretion. In the second one participants received test meals which contained saccharose or isomaltulose in combination with milk protein. The third set of participants underwent randomized oral protein tests with whey protein or casein. Incretins, glucagon, C-peptide, and insulin were profiled by specific immunological assays.. 50 g of the sugars alone suppressed glucagon in controls but slightly less in type 2 diabetes patients. Participants with type 2 diabetes showed excessive glucagon responses within 15 min and lasting over 3 h, while the obese controls showed small initial and delayed greater glucagon responses to mixed meals. The release of GIP was significantly faster and greater with SAC compared to ISO, while GLP-1 showed an inverse pattern. The glucagon responses to whey or casein were only moderately increased in type 2 diabetes patients without a left shift of the dose response curve.. The rapid hypersecretion of glucagon after mixed meals in type 2 diabetes patients compared to controls is unaffected by endogenous incretins. The defective suppression of glucagon by glucose combined with hypersecretion to protein is required for the exaggerated response.. NCT03806920, NCT02219295, NCT04564391. Topics: Blood Glucose; Caseins; Diabetes Mellitus, Type 2; Glucagon; Glucagon-Like Peptide 1; Humans; Incretins; Insulin; Meals; Obesity; Sucrose; Sugars | 2023 |
Sustained release of GLP-1 analog from γ-PGA-PAE copolymers for management of type 2 diabetes.
GLP-1 has been clinically exploited for treating type 2 diabetes, while its short circulation half-life requires multiple daily injections to maintain effective glycemic control, thus limiting its widespread application. Here we developed a drug delivery system based on self-assembling polymer-amino acid conjugates (γ-PGA-PAE) to provide sustained release of GLP-1 analog (DLG3312). The DLG3312 loaded γ-PGA based nanoparticles (DLG3312@NPs) exhibited a spherical shape with a good monodispersity under transmission electron microscope (TEM) observation. The DLG3312 encapsulation was optimized, and the loading efficiency was as high as 78.4 ± 2.2 %. The transformation of DLG3312@NPs to network structures was observed upon treatment with the fresh serum, resulting in a sustained drug release. The in vivo long-term hypoglycemic assays indicated that DLG3312@NPs significantly reduced blood glucose and glycosylated hemoglobin level. Furthermore, DLG3312@NPs extended the efficacy of DLG3312, leading to a decrease in the dosing schedule that from once a day to once every other day. This approach combined the molecular and materials engineering strategies that offered a unique solution to maximize the availability of anti-diabetic drug and minimize its burdens to type 2 diabetic patients. Topics: Delayed-Action Preparations; Diabetes Mellitus, Type 2; Glucagon-Like Peptide 1; Humans; Hypoglycemic Agents; Polymers | 2023 |
Jiang-Tang-San-Huang pill alleviates type 2 diabetes mellitus through modulating the gut microbiota and bile acids metabolism.
Jiang-Tang-San-Huang (JTSH) pill, a traditional Chinese medicine (TCM) prescription, has long been applied to clinically treat type 2 diabetes mellitus (T2DM), while the underlying antidiabetic mechanism remains unclarified. Currently, it is believed that the interaction between intestinal microbiota and bile acids (BAs) metabolism mediates host metabolism and promotes T2DM.. To elucidate the underlying mechanisms of JTSH for treating T2DM with animal models.. In this study, male SD rats received high-fat diet (HFD) and streptozotocin (STZ) injection to induce T2DM and were treated with different dosages (0.27, 0.54 and 1.08 g/kg) of JTSH pill for 4 weeks; metformin was given as a positive control. Alterations of gut microbiota and BA profiles in the distal ileum were assessed by 16S ribosomal RNA gene sequencing and ultra-high performance liquid chromatography-tandem mass spectrometry (UPLC-MS/MS), respectively. Additionally, we conducted quantitative Real Time-PCR and western blotting to determine the mRNA and protein expression levels of intestinal farnesoid X receptor (FXR), fibroblast growth factor 15 (FGF15), Takeda G-protein-coupled receptor 5 (TGR5) and glucagon-like peptide 1 (GLP-1) as well as hepatic cytochrome P450, family 7, subfamily a, poly-peptide 1 (CYP7A1) and cytochrome P450, family 8, subfamily b, poly-peptide 1 (CYP8B1), which are involved in BAs metabolism and enterohepatic circulation.. Here, the results revealed that JTSH treatment significantly ameliorated hyperglycaemia, insulin resistance (IR), hyperlipidaemia, and pathological changes in the pancreas, liver, kidney and intestine and reduced the serum levels of pro-inflammatory cytokines in T2DM model rats. 16S rRNA sequencing and UPLC-MS/MS showed that JTSH treatment could modulate gut microbiota dysbiosis by preferentially increasing bacteria (e.g., Bacteroides, Lactobacillus, Bifidobacterium) with bile-salt hydrolase (BSH) activity, which might in turn lead to the accumulation of ileal unconjugated BAs (e.g., CDCA, DCA) and further upregulate the intestinal FXR/FGF15 and TGR5/GLP-1 signaling pathways.. The study demonstrated that JTSH treatment could alleviate T2DM by modulating the interaction between gut microbiota and BAs metabolism. These findings suggest that JTSH pill may serve as a promising oral therapeutic agent for T2DM. Topics: Animals; Bile Acids and Salts; Chromatography, Liquid; Cytochrome P-450 Enzyme System; Diabetes Mellitus, Type 2; Gastrointestinal Microbiome; Glucagon-Like Peptide 1; Liver; Male; Rats; Rats, Sprague-Dawley; RNA, Ribosomal, 16S; Tandem Mass Spectrometry | 2023 |
Risk of Diabetic Retinopathy between Sodium-Glucose Cotransporter-2 Inhibitors and Glucagon-Like Peptide-1 Receptor Agonists.
To compare risk of diabetic retinopathy (DR) between patients taking sodium-glucose cotransporter-2 inhibitors (SGLT2is) and those taking glucagon-like peptide-1 receptor agonists (GLP1-RAs) in routine care.. This retrospective cohort study emulating a target trial included patient data from the multi-institutional Chang Gung Research Database in Taiwan. Totally, 33,021 patients with type 2 diabetes mellitus using SGLT2is and GLP1-RAs between 2016 and 2019 were identified. 3,249 patients were excluded due to missing demographics, age <40 years, prior use of any study drug, a diagnosis of retinal disorders, a history of receiving vitreoretinal procedure, no baseline glycosylated hemoglobin, or no follow-up data. Baseline characteristics were balanced using inverse probability of treatment weighting with propensity scores. DR diagnoses and vitreoretinal interventions served as the primary outcomes. Occurrence of proliferative DR and DR receiving vitreoretinal interventions were regarded as vision-threatening DR.. There were 21,491 SGLT2i and 1,887 GLP1-RA users included for the analysis. Patients receiving SGLT2is and GLP-1 RAs exhibited comparable rate of any DR (subdistribution hazard ratio [SHR], 0.90; 95% confidence interval [CI], 0.79 to 1.03), whereas the rate of proliferative DR (SHR, 0.53; 95% CI, 0.42 to 0.68) was significantly lower in the SGLT2i group. Also, SGLT2i users showed significantly reduced risk of composite surgical outcome (SHR, 0.58; 95% CI, 0.48 to 0.70).. Compared to those taking GLP1-RAs, patients receiving SGLT2is had a lower risk of proliferative DR and vitreoretinal interventions, although the rate of any DR was comparable between the SGLT2i and GLP1-RA groups. Thus, SGLT2is may be associated with a lower risk of vision-threatening DR but not DR development. Topics: Adult; Diabetes Mellitus, Type 2; Diabetic Retinopathy; Glucagon-Like Peptide 1; Glucagon-Like Peptide-1 Receptor; Glucose; Humans; Hypoglycemic Agents; Retrospective Studies; Sodium; Sodium-Glucose Transporter 2 Inhibitors | 2023 |
The role of mosapride and levosulpiride in gut function and glycemic control in diabetic rats.
Gastroparesis is a well-known consequence of long-standing diabetes that presents with gastric dysmotility in the absence of gastric outlet obstruction. This study aimed to evaluate the therapeutic effects of mosapride and levosulpiride on improving gastric emptying in type 2 diabetes mellitus (T2DM) while regulating glycemic levels.. Rats were divided into the normal control, untreated diabetic, metformin-treated (100 mg/kg/day), mosapride-treated (3 mg/kg/day), levosulpiride-treated (5 mg/kg/day), metformin (100 mg/kg/day) + mosapride (3 mg/kg/day)-treated, and metformin (100 mg/kg/day) + levosulpiride (5 mg/kg/day)-treated diabetic groups. T2DM was induced by a streptozotocin-nicotinamide model. Fourweeks from diabetes onset, the treatment was started orally daily for 2 weeks. Serum glucose, insulin, and glucagon-like peptide 1 (GLP-1) levels were measured. Gastric motility study was performed using isolated rat fundus and pylorus strip preparations. Moreover, the intestinal transit rate was measured.. Mosapride and levosulpiride administration showed a significant decrease in serum glucose levels with improvement of gastric motility and intestinal transit rate. Mosapride showed a significant increase in serum insulin and GLP-1 levels. Metformin with mosapride and levosulpiride co-administration showed better glycemic control and gastric emptying than either drug administered alone.. Mosapride and levosulpiride showed comparable prokinetic effects. Metformin administration with mosapride and levosulpiride showed better glycemic control and prokinetic effects. Mosapride provided better glycemic control than levosulpiride. Metformin + mosapride combination provided superior glycemic control and prokinetic effects. Topics: Animals; Blood Glucose; Diabetes Mellitus, Experimental; Diabetes Mellitus, Type 2; Gastroparesis; Glucagon-Like Peptide 1; Glycemic Control; Insulins; Metformin; Rats | 2023 |
The efficacy and safety of combined GLP-1RA and basal insulin therapy among inadequately controlled T2D with premixed insulin therapy.
This study investigated the effect of a combination of glucagon-like peptide-1 receptor agonist (GLP-1 RA) and basal insulin (BI) in poorly controlled type 2 diabetes mellitus previously treated with premixed insulin. The possible therapeutic benefit of the subject is mainly hoped to provide a direction for optimizing treatment options to reduce the risk of hypoglycemia and weight gain. A single-arm, open-label study was conducted. The antidiabetic regimen was switched to GLP-1 RA plus BI to replace previous treatment with premixed insulin in type 2 diabetes mellitus subjects. After 3 months of treatment modification, GLP-1 RA plus BI was compared for superior outcomes by continuous glucose monitoring system. There were 34 subjects at the beginning, 4 withdrew due to gastrointestinal discomfort, and finally 30 subjects completed the trial, of which 43% were male; the average age was 58 ± 9 years old, and the average duration of diabetes was 12 ± 6 years, the baseline glycated hemoglobin level was 8.6 ± 0.9 %. The initial insulin dose of premixed insulin was 61 ± 18 units, and the final insulin dose of GLP-1 RA + BI was 32 ± 12 units (P < .001). Time out of range (from 59%-42%), time-in-range (from 39%-56%) as well as glucose variability index including standard deviation also improved, mean magnitude of glycemic excursions, mean daily difference and continuous population in continuous glucose monitoring system, continuous overall net glycemic action (CONGA). Also noted was a decrease in body weight (from 70.9 kg-68.6 kg) and body mass index (all P values < .05). It provided important information for physicians to decide to modify therapeutic strategy as individualized needs. Topics: Aged; Blood Glucose; Blood Glucose Self-Monitoring; Diabetes Mellitus, Type 2; Female; Glucagon-Like Peptide 1; Glucagon-Like Peptide-1 Receptor; Glucose; Glycated Hemoglobin; Humans; Hypoglycemic Agents; Insulin; Male; Middle Aged | 2023 |
Expression of Neurotensin and Its Receptors Along the Intestinal Tract in Type 2 Diabetes Patients and Healthy Controls.
Enteroendocrine N cells secrete neurotensin (NTS). NTS reduces food intake in rodents and may increase insulin release. In humans, postprandial NTS responses increase following Roux-en-Y gastric bypass, associating the hormone with the glucose- and body weight-lowering effects of these procedures.. We looked at N cell density and mucosal messenger RNA (mRNA) expression profiles of NTS and NTS receptors in type 2 diabetes (T2D) patients and healthy controls.. Using double-balloon enteroscopy, 12 patients with T2D and 12 sex-, age-, and body mass index-matched healthy controls had mucosa biopsies taken from the entire length of the small intestine (at 30-cm intervals) and from 7 anatomically well-defined locations in the large intestine. Biopsies were analyzed using immunohistochemistry and mRNA sequencing.. N cell density and NTS mRNA expression gradually increased from the duodenum to the ileum, while negligible NTS-positive cells and NTS mRNA expression were observed in the large intestine. NTS receptor 1 and 2 mRNA expression were not detected, but sortilin, a single-pass transmembrane neuropeptide receptor of which NTS also is a ligand, was uniformly expressed in the intestines. Patients with T2D exhibited lower levels of NTS-positive cells and mRNA expression than healthy controls, but this was not statistically significant after adjusting for multiple testing.. This unique intestinal mapping of N cell density and NTS expression shows increasing levels from the small intestine's proximal to distal end (without differences between patients with T2D and healthy controls), while negligible N-cells and NTS mRNA expression were observed in the large intestine. Sortilin was expressed throughout the intestines in both groups; no NTS receptor 1 or 2 mRNA expression were detected. Topics: Diabetes Mellitus, Type 2; Glucagon-Like Peptide 1; Humans; Intestines; Neurotensin; Proteins; RNA, Messenger | 2023 |
[Anti-obesity drugs : from previous disappointments to new hopes].
Both physicians and patients dream of an efficacious and safe pharmacological approach to treat obesity. Unfortunately, most anti-obesity drugs prescribed since the fifties were associated with an unfavourable risk profile that led to numerous withdrawals. Medications issued from pharmaco-chemistry that mainly target brain amines to reduce appetite have been abandoned because of potential cardiovascular and neuropsychiatric toxicities. More recently, biological medications emerged, especially GLP-1 (Glucagon-Like Peptide-1) receptor agonists, well-known to manage type 2 diabetes and now recommended at higher doses for the treatment of obesity (liraglutide, semaglutide). A dual agonist that targets both GLP-1 and GIP (Glucose-dependent Insulinotropic Polypeptide) receptors (tirzepatide) appears to be even more potent as glucose-lowering agent and is currently tested as an anti-obesity agent. Many other pharmacological approaches are currently investigated but they should not mask the importance of life-style measurements.. Médecins et patients rêvent d’une approche pharmacologique efficace et sûre pour traiter l’obésité. Hélas, la plupart des médicaments anti-obésité testés depuis les années 50 ont été grevés d’un profil de risque défavorable, ce qui a amené de nombreux retraits du marché. Les médicaments issus de la pharmacochimie ciblant principalement les amines cérébrales pour freiner l’appétit ont été abandonnés en raison de leur toxicité potentielle, cardiovasculaire et neuropsychiatrique. Une nouvelle opportunité est offerte avec l’avènement de médicaments biologiques, en particulier des analogues du GLP-1 (Glucagon-Like Peptide-1) bien connus pour traiter le diabète de type 2 et aussi commercialisés à plus fortes doses pour traiter l’obésité (liraglutide, sémaglutide). Un agoniste double ciblant à la fois les récepteurs du GLP-1 et du GIP («Glucose-dependent Insulinotropic Polypeptide»), le tirzépatide, s’avère encore plus puissant comme médicament antidiabétique et est actuellement testé comme agent anti-obésité. Un grand nombre d’autres approches pharmacologiques sont en cours d’investigation, mais toutes ces initiatives ne doivent pas scotomiser l’importance des mesures hygiéno-diététiques. Topics: Anti-Obesity Agents; Diabetes Mellitus, Type 2; Glucagon-Like Peptide 1; Glucagon-Like Peptide-1 Receptor; Glucose; Humans; Hypoglycemic Agents; Obesity | 2023 |
The cardiovascular and renal effects of glucagon-like peptide 1 receptor agonists in patients with advanced diabetic kidney disease.
To determine whether glucagon-like peptide 1 receptor agonists (GLP-1RAs) have cardiovascular and renal protective effects in patients with advanced diabetic kidney disease (DKD) with an estimated glomerular filtration rate (eGFR) < 30 mL/min per 1.73 m. In this cohort study, patients with type 2 diabetes mellitus and eGFR < 30 mL/min per 1.73 m. A total of 8922 participants [mean (SD) age 68.4 (11.5) years; 4516 (50.6%) males; GLP-1RAs, n = 759; DPP-4is, n = 8163] were eligible for this study. During a mean follow-up of 2.1 years, 78 (13%) and 204 (13.8%) patients developed composite cardiovascular events in the GLP-1RA and DPP-4i groups, respectively [hazard ratio (HR) 0.88, 95% confidence interval CI 0.68-1.13]. Composite kidney events were reported in 134 (38.2%) and 393 (44.2%) patients in the GLP-1RA and DPP-4i groups, respectively (subdistribution HR 0.72, 95% CI 0.56-0.93).. GLP-1RAs had a neutral effect on the composite cardiovascular outcomes but reduced composite kidney events in the patients with advanced DKD compared with DPP-4is. Topics: Aged; Cardiovascular Diseases; Cohort Studies; Diabetes Mellitus, Type 2; Diabetic Nephropathies; Dipeptidyl-Peptidase IV Inhibitors; Female; Glucagon-Like Peptide 1; Glucagon-Like Peptide-1 Receptor; Humans; Hypoglycemic Agents; Kidney; Male | 2023 |
Circulating levels of gastrointestinal hormones in prediabetes reversing to normoglycemia or progressing to diabetes in a year-A cross-sectional and prospective analysis.
We aimed to compare the concentrations of GLP-1, glucagon and GIP (established regulators of glucose homeostasis) and glicentin (emerging new metabolic marker)during an OGTT in patients with normal glucose tolerance (NGT), prediabetes and diabetes at onset, and one-year before, when all had prediabetes.. GLP-1, glucagon, GIP and glicentin concentrations were measured and compared with markers of body composition, insulin sensitivity and β-cell function at a 5-timepoint OGTT in 125 subjects (30 diabetes, 65 prediabetes, 30 NGT) and in 106 of them one-year before, when all had prediabetes.. At baseline, when all subjects were in prediabetic state, hormonal levels did not differ between groups. One year later, patients progressing to diabetes had lower postprandial increases of glicentin and GLP-1, lower postprandial decrease of glucagon, and higher levels of fasting GIP compared to patients regressing to NGT. Changes in glicentin and GLP-1 AUC within this year correlated negatively with changes in Glucose AUC of OGTT and with changes in markers of beta cell function.. Incretins, glucagon and glicentin profiles in prediabetic state cannot predict future glycemic traits, but prediabetes progressing to diabetes is accompanied by deterioration of postprandial increases of GLP-1 and glicentin. Topics: Blood Glucose; Cross-Sectional Studies; Diabetes Mellitus, Type 2; Gastric Inhibitory Polypeptide; Gastrointestinal Hormones; Glicentin; Glucagon; Glucagon-Like Peptide 1; Glucose Tolerance Test; Humans; Insulin; Prediabetic State | 2023 |
Weight Loss Versus Glycemic Control as the Primary Treatment Target in Newly Diagnosed Type 2 Diabetes: Why Choose When You Can Have Both?
Weight loss has been associated with significant improvements in glycemic control, quality of life, and comorbidities in people with type 2 diabetes. Furthermore, achieving diabetes remission can reduce the risk of microvascular complications and mitigate the burden of diabetes on healthcare systems. However, preventing weight regain is challenging in the long term. Strict glycemic control, particularly in the early stages of the disease, can reduce the subsequent risk of microvascular complications and specific macrovascular endpoints in the long run; however, its impact on cardiovascular and all-cause mortality remains controversial. New classes of antidiabetic agents, namely glucagon-like peptide 1 receptor agonists and sodium-glucose cotransporter 2 inhibitors, have been shown to reduce cardiorenal risk and induce weight loss, in addition to effectively lowering blood glucose with a minimal risk of hypoglycemia. Recently, it has been debated whether weight loss or glycemic control should be the first priority in people with a recent diagnosis of type 2 diabetes. This article aims to discuss the debate from a clinical perspective, evaluate the advantages and disadvantages of each therapeutic strategy, and assess the impact of both approaches on the future risk of diabetic complications, based on the latest evidence. Given that both goals are equally important, the authors suggest that merging the two strategies, with the early and aggressive use of combination therapies consisting of glucagon-like peptide 1 receptor agonists and sodium-glucose cotransporter 2 inhibitors, will confer maximum benefits in terms of weight loss and glycemic control, and will reduce the future risk of complications from diabetes. A personalized approach that takes into account specific patient characteristics, including age, sex, race, frailty, and cognitive status, among others, can lead to more effective diabetes care. Topics: Blood Glucose; Diabetes Mellitus, Type 2; Glucagon-Like Peptide 1; Glucagon-Like Peptide-1 Receptor; Glycemic Control; Humans; Hypoglycemic Agents; Quality of Life; Sodium; Weight Loss | 2023 |
Evaluating the Effect of Hypoglycemic Agents on Diabetic Retinopathy Progression.
Newer hypoglycemics such as dipeptidyl peptidase 4 (DPP-4) inhibitors, sodium-glucose cotransporter-2 (SGLT-2) inhibitors, glucagon-like peptide-1 (GLP-1) receptor agonists have been increasingly used in diabetes. This study aimed to assess the relationship between usage of these hypoglycemic agents and effect on diabetic retinopathy (DR).. Using the Vestrum Health Retina Database, patients with DR with 1 year follow-up after use of a hypoglycemic agent were included and stratified by agent, including no pharmacotherapy.. Of 60,649 eyes, in 1 year after hypoglycemic agent usage, progression rates from severe nonproliferative diabetic retinopathy (NPDR) to proliferative diabetic retinopathy (PDR) were the following: DPP-4 (17%), SGLT-2 (12%), GLP-1 (21%), metformin (18%), and none (20%). Progression rates from moderate NPDR to severe NPDR or PDR were the following: DPP-4 (11%), SGLT-2 (10%), GLP-1 (11%), metformin (10%), none (13%). Progression rates from mild NPDR to moderate/severe NPDR or PDR were the following: DPP-4 (6%), SGLT-2 (9%), GLP-1 (9%), metformin (7%), and none (10%).. Within a large real-world database, patients prescribed GLP-1 agonists were found to have DR progression rates comparable to those of patients receiving no hypoglycemic agents. Topics: Diabetes Mellitus, Type 2; Diabetic Retinopathy; Dipeptidyl-Peptidase IV Inhibitors; Glucagon-Like Peptide 1; Humans; Hypoglycemic Agents; Metformin | 2023 |
GLP-1 agonist Liraglutide prevents MK‑801-induced schizophrenia‑like behaviors and BDNF, CREB, p-CREB, Trk-B expressions in the hippocampus and prefrontal cortex in Balb/c mice.
Glucagon-like peptide 1 (GLP-1) agonists are among the agents that can be used to treat type 2 diabetes mellitus, and they have also been reported to have neuroprotective effects. This study examined the effects of GLP-1 agonist Liraglutide on CREB, BDNF, Trk-B expression and emotional/cognitive behaviors in an experimental schizophrenia-like behavior model induced by MK-801. MK-801 (0.25 mg/kg, 0.1 ml/kg body weight) and/or Liraglutide (300 mcg/kg) were injected intraperitoneally once a day for 7 weeks into 8-10 weeks old male Balb/c mice (n = 78). Mice were randomly divided into 5 groups: Saline+Saline, MK-801 +Saline, Liraglutide+Saline, MK-801 +Liraglutide co-treatment, and Liraglutide+MK-801 co-treatment. A Morris water maze test, an elevated plus maze test, and an open field test were performed after injection. Western blots were performed on mice' hippocampus and PFC for BDNF, Trk-B, CREB, and p-CREB expression. Our study found that MK-801 impaired emotional and cognitive functions in mice. MK-801 administration did not affect Liraglutide's positive effects on spatial learning and memory activity in the Liraglutide+MK-801 group. Liraglutide administration (Liraglutide+MK-801 group) improved the BDNF/Trk-B and p-CREB/CREB ratio in the hippocampus, and the p-CREB/CREB ratio in the PFC to the control group level. The negative effects of MK-801 on cognitive behavior were not reversed by Liraglutide in the MK-801 +Liraglutide group. In conclusion, Liraglutide does not affect NMDA receptor blockade-induced emotional and cognitive behaviors. However, it has a protective effect against cognitive impairment. Furthermore, it is possible that the GLP-1 receptors in the hippocampus and PFC are involved in the modulation of NMDA receptor activity through CREB activation/deactivation. Topics: Animals; Brain-Derived Neurotrophic Factor; Diabetes Mellitus, Type 2; Dizocilpine Maleate; Glucagon-Like Peptide 1; Hippocampus; Liraglutide; Male; Mice; Mice, Inbred BALB C; Prefrontal Cortex; Receptors, N-Methyl-D-Aspartate; Schizophrenia | 2023 |
[GLP-1 and GIP receptor agonists: emerging therapies for obesity].
Obesity is a chronic and recurrent metabolic disease associated with serious complications and increased mortality. Bariatric surgery was until recently the only intervention that could lead to significant and sustained weight loss. A better understanding of the endocrine regulation of appetite has allowed the development of new treatments. GLP-1 analogues are already available and a dual treatment of GLP-1 analogue and GIP has recently shown even greater efficacy in terms of weight loss. We present a summary of the known mechanisms of action and clinical data that support the use of these molecules in the treatment of obesity.. L’obésité est une maladie métabolique chronique et récidivante associée à de graves complications et à une mortalité accrue. La chirurgie bariatrique était jusqu’à récemment la seule intervention permettant d’obtenir une perte de poids significative et son maintien. Une meilleure compréhension de la régulation endocrinienne de l’appétit a permis le développement de nouveaux traitements. Les analogues du GLP-1 sont déjà disponibles et une double activation des récepteurs du GLP-1 et du GIP (double agoniste) a récemment montré une efficacité encore plus importante en termes de perte pondérale. Nous proposons une synthèse des mécanismes d’action connus et des données cliniques qui soutiennent l’utilisation de ces molécules dans le traitement de l’obésité. Topics: Diabetes Mellitus, Type 2; Gastric Inhibitory Polypeptide; Glucagon-Like Peptide 1; Glucagon-Like Peptide-1 Receptor; Humans; Hypoglycemic Agents; Obesity; Weight Loss | 2023 |
Synthesis of menarandroside A from dehydroepiandrosterone.
Menarandroside A, which bears a 12α-hydroxypregnenolone steroid backbone, was isolated from the plant, Topics: Dehydroepiandrosterone; Diabetes Mellitus, Type 2; Glucagon-Like Peptide 1; Humans; Oxidation-Reduction; Steroids | 2023 |
Severe and fatal COVID-19 is characterised by increased circulating glucagon like peptide 1 and procalcitonin modulated by type 2 diabetes.
Endotoxemia commonly occurs in severe and fatal COVID-19, suggesting that concomitant bacterial stimuli may amplify the innate immune response induced by SARS-CoV-2. We previously demonstrated that the endogenous glucagon like peptide 1 (GLP-1) system in conjunction with increased procalcitonin (PCT) is hyperactivated in patients with severe Gram-negative sepsis and modulated by type 2 diabetes (T2D). We aimed to determine the association of COVID-19 severity with endogenous GLP-1 activation upregulated by increased specific pro-inflammatory innate immune response in patients with and without T2D.. Plasma levels of total GLP-1, IL-6, and PCT were estimated on admission and during hospitalisation in 61 patients (17 with T2D) with non-severe and severe COVID-19.. COVID-19 patients demonstrated ten-fold increase of IL-6 levels regardless of disease severity. Increased admission GLP-1 levels (p = 0.03) accompanied by two-fold increased PCT were found in severe as compared with non-severe patients. Moreover, GLP-1 and PCT levels were significantly increased in non-survived as compared with survived patients at admission (p = 0.01 and p = 0.001, respectively) and at 5 to 6 days of hospitalisation (p = 0.05). Both non-diabetic and T2D patients demonstrated a positive correlation between GLP-1 and PCT response (r = 0.33, p = 0.03, and r = 0.54, p = 0.03, respectively), but the intensity of this joint pro-inflammatory/GLP-1 response was modulated by T2D. In addition, hypoxaemia down-regulated GLP-1 response only in T2D patients with bilateral lung damage.. The persistent joint increase of endogenous GLP-1 and PCT in severe and fatal COVID-19 suggests a role of concomitant bacterial infection in disease exacerbation. Early elevation of endogenous GLP-1 may serve as a new biomarker of COVID-19 severity and fatal outcome. Topics: Biomarkers; COVID-19; Diabetes Mellitus, Type 2; Glucagon-Like Peptide 1; Humans; Interleukin-6; Procalcitonin; SARS-CoV-2 | 2023 |
Acute Inhibition of Intestinal Neprilysin Enhances Insulin Secretion via GLP-1 Receptor Signaling in Male Mice.
The peptidase neprilysin modulates glucose homeostasis by cleaving and inactivating insulinotropic peptides, including some produced in the intestine such as glucagon-like peptide-1 (GLP-1). Under diabetic conditions, systemic or islet-selective inhibition of neprilysin enhances beta-cell function through GLP-1 receptor (GLP-1R) signaling. While neprilysin is expressed in intestine, its local contribution to modulation of beta-cell function remains unknown. We sought to determine whether acute selective pharmacological inhibition of intestinal neprilysin enhanced glucose-stimulated insulin secretion under physiological conditions, and whether this effect was mediated through GLP-1R. Lean chow-fed Glp1r+/+ and Glp1r-/- mice received a single oral low dose of the neprilysin inhibitor thiorphan or vehicle. To confirm selective intestinal neprilysin inhibition, neprilysin activity in plasma and intestine (ileum and colon) was assessed 40 minutes after thiorphan or vehicle administration. In a separate cohort of mice, an oral glucose tolerance test was performed 30 minutes after thiorphan or vehicle administration to assess glucose-stimulated insulin secretion. Systemic active GLP-1 levels were measured in plasma collected 10 minutes after glucose administration. In both Glp1r+/+ and Glp1r-/- mice, thiorphan inhibited neprilysin activity in ileum and colon without altering plasma neprilysin activity or active GLP-1 levels. Further, thiorphan significantly increased insulin secretion in Glp1r+/+ mice, whereas it did not change insulin secretion in Glp1r-/- mice. In conclusion, under physiological conditions, acute pharmacological inhibition of intestinal neprilysin increases glucose-stimulated insulin secretion in a GLP-1R-dependent manner. Since intestinal neprilysin modulates beta-cell function, strategies to inhibit its activity specifically in the intestine may improve beta-cell dysfunction in type 2 diabetes. Topics: Animals; Diabetes Mellitus, Type 2; Glucagon-Like Peptide 1; Glucagon-Like Peptide-1 Receptor; Glucose; Insulin; Insulin Secretion; Intestines; Male; Mice; Mice, Inbred C57BL; Neprilysin; Thiorphan | 2023 |
Management of Type 2 Diabetes Mellitus in the Very Elderly: One Practice's Experience.
Type 2 diabetes mellitus (T2DM) affects 25% of adults over age 65. Nevertheless, few clinical trials include patients over age 75.. This case series reports retrospective data on a cohort of 85 patients aged 80 and over (mean 88.1, range 80-104) with T2DM, managed by a single endocrinologist. The practice's computerized data base was searched for all patients 80 years of age and older with a diagnosis of T2DM.. The major observations were the significant decrease in the use of agents associated with hypoglycemia (sulfonylureas and insulin), and the beneficial and well-tolerated use of glucagon like peptide-1 receptor analogues (GLP-1 RA). The mean A1c in the entire cohort dropped from 7.6% to 6.6% over a mean of 9 months. Nearly one-half of the cohort were treated with GLP1-RA, reflecting studies demonstrating the safety and efficacy of this class of drugs in less elderly patients. At presentation, 75% were on sulfonylurea and/or insulin; this number was reduced to 27%. Furthermore, none of the patients required short-acting (bolus) insulin to achieve the individualized A1c target.. Patients with T2DM aged 80 and over respond well to GLP1-RA drugs, drastically reducing the need for agents associated with hypoglycemia. The important question, which will require larger and prospective studies, is whether the lowering of A1c, as shown in this paper, and the use of GLP-1 RA specifically, are associated with improved morbidity and mortality in the very elderly. Topics: Adult; Aged; Aged, 80 and over; Diabetes Mellitus, Type 2; Glucagon-Like Peptide 1; Glucagon-Like Peptide-1 Receptor; Glycated Hemoglobin; Humans; Hypoglycemia; Hypoglycemic Agents; Insulin; Insulin, Regular, Human; Prospective Studies; Retrospective Studies; Sulfonylurea Compounds | 2023 |
Time-dependent effect of GLP-1 receptor agonists on cardiovascular benefits: a real-world study.
Glucagon-like peptide-1 receptor agonists (GLP-1 RAs) have shown cardiovascular benefits in cardiovascular outcome trials in type 2 diabetes mellitus. However, the most convincing evidence was obtained in subjects with established cardiovascular (CV) disease. We analyzed the determinants of GLP-1 RA-mediated CV protection in a real-world population of persons with type 2 diabetes with and without a history of CV events with long-term follow-up.. Retrospective cohort study of 550 individuals with type 2 diabetes (395 in primary CV prevention, 155 in secondary CV prevention), followed at a single center after the first prescription of a GLP-1 RA between 2009 and 2019. CV and metabolic outcomes were assessed.. Median duration of follow-up was 5.0 years (0.25-10.8) in primary prevention and 3.6 years (0-10.3) in secondary prevention, with a median duration of treatment of 3.2 years (0-10.8) and 2.5 years (0-10.3) respectively. In the multivariable Cox regression model considering GLP-1 RA treatment as a time-dependent covariate, in the primary prevention group, changes in BMI and glycated hemoglobin did not have an impact on MACE risk, while age at the time of GLP-1 initiation (HR 1.08, 95% CI 1.03-1.14, p = 0.001) and GLP-1 RA cessation by time (HR 3.40, 95% CI 1.82-6.32, p < 0.001) increased the risk of MACE. Regarding the secondary prevention group, only GLP-1 RA cessation by time (HR 2.71, 95% CI 1.46-5.01, p = 0.002) increased the risk of MACE. With respect to those who withdrew treatment, subjects who continued the GLP-1 RA had significantly greater weight loss and lower glycated hemoglobin levels during follow-up.. In this real-world type 2 diabetes population, discontinuation of GLP-1 RA treatment was associated to a higher risk of major cardiovascular events, in both subjects with and without a history of CV events. Topics: Cardiovascular Diseases; Diabetes Mellitus, Type 2; Glucagon-Like Peptide 1; Glucagon-Like Peptide-1 Receptor; Glycated Hemoglobin; Humans; Hypoglycemic Agents; Retrospective Studies | 2023 |
Possible Advantage of Glucagon-Like Peptide 1 Receptor Agonists for Kidney Transplant Recipients With Type 2 Diabetes.
Glucagon-like peptide-1 (GLP-1) receptor agonists (RAs) have the potential to improve native kidney function.. This work aimed to elucidate the possible protective effects of GLP-1 RAs on kidney graft function after successful kidney transplantation (KTX).. This retrospective cohort study included all KTX recipients (KTRs) at our facility with type 2 diabetes who were followed up from 1 month post-transplantation for 24 months or longer as of December 31, 2020. We investigated associations between the use of GLP-1 RAs and other antidiabetic medications (non-GLP-1 RAs) and the risk of sustained estimated glomerular filtration rate (eGFR) reduction (40% reduction compared with baseline for 4 months) for KTRs with type 2 diabetes. We calculated the propensity score of initiating GLP-1 RAs compared with that of initiating non-GLP-1 RAs as a function of baseline covariates using logistic regression. The inverse probability of the treatment-weighted odds ratio was estimated to control for baseline confounding variables. Sodium-glucose cotransporter 2 inhibitor use was a competing event. The primary outcome was sustained eGFR reduction of at least 40% from baseline for 4 months post-transplantation.. Seventy-three patients were GLP-1 RA users and 73 were non-GLP-1 RA users. Six patients and 1 patient in the non-GLP-1 RA and GLP-1 RA groups had sustained eGFR reduction. GLP-1 RA use after KTX was associated with a lower risk of sustained eGFR reduction.. GLP-1 RAs resulted in lower eGFR reduction compared with non-GLP-1 RAs and may contribute to better kidney graft survival after KTX. Topics: Diabetes Mellitus, Type 2; Glucagon-Like Peptide 1; Glucagon-Like Peptide-1 Receptor; Humans; Hypoglycemic Agents; Kidney Transplantation; Renal Insufficiency; Retrospective Studies | 2023 |
Glucagon-like peptide 1 receptor agonists and the potential risk of pancreatic carcinoma: a pharmacovigilance study using the FDA Adverse Event Reporting System and literature visualization analysis.
There are increasing data on the potential risk of pancreatic carcinoma associated with glucagon-like peptide 1 receptor agonists (GLP-1RAs).. The study aimed to determine whether GLP-1RAs are associated with increased detection of pancreatic carcinoma based on the FDA Adverse Events Reporting System and clarify its potential mechanisms through keyword co-occurrence analysis from literature database.. Disproportionality and Bayesian analyses were used for signal detection using reporting odds ratio (ROR), proportional reporting ratio (PRR), information component (IC), and empirical Bayesian geometric mean (EBGM). Mortality, life-threatening events, and hospitalizations were also investigated. VOSviewer was adopted to generate visual analysis of keyword hotspots.. A total of 3073 pancreatic carcinoma cases were related to GLP-1RAs. Five GLP-1RAs were detected with signals for pancreatic carcinoma. Liraglutide had the strongest signal detection (ROR 54.45, 95% CI 51.21-57.90; PRR 52.52, 95% CI 49.49-55.73; IC 5.59; EBGM 48.30). The signals of exenatide (ROR 37.32, 95% CI 35.47-39.28; PRR 36.45, 95% CI 34.67-38.32; IC 5.00; EBGM 32.10) and lixisenatide (ROR 37.07, 95% CI 9.09-151.09; PRR 36.09; 95% CI 9.20-141.64; IC 5.17, EBGM 36.09) were stronger than those of semaglutide (ROR 7.43, 95% CI 5.22-10.57; PRR 7.39; 95% CI 5.20-10.50; IC 2.88, EBGM 7.38) and dulaglutide (ROR 6.47, 95% CI 5.56-7.54; PRR 6.45; 95% CI 5.54-7.51; IC 2.67, EBGM 6.38). The highest mortality rate occurred in exenatide (63.6%). Based on the bibliometric investigation, cAMP/protein-kinase, Ca. Based on this pharmacovigilance study, GLP-1RAs, except albiglutide, are associated with pancreatic carcinoma. Topics: Bayes Theorem; Diabetes Mellitus, Type 2; Exenatide; Glucagon-Like Peptide 1; Glucagon-Like Peptide-1 Receptor; Humans; Hypoglycemic Agents; Pancreatic Neoplasms; Pharmacovigilance | 2023 |
Disparities in the Glycemic and Incretin Responses to Intraduodenal Glucose Infusion Between Healthy Young Men and Women.
Premenopausal women are at a lower risk of type 2 diabetes (T2D) compared to men, but the underlying mechanism(s) remain elusive. The secretion of the incretin hormones, glucose-dependent insulinotropic polypeptide (GIP) and glucagon-like peptide-1 (GLP-1), from the small intestine is a major determinant of glucose homeostasis and may be influenced by sex.. This study compared blood glucose and plasma insulin and incretin responses to intraduodenal glucose infusions in healthy young males and females.. In Study 1, 9 women and 20 men received an intraduodenal glucose infusion at 2 kcal/min for 60 minutes. In Study 2, 10 women and 26 men received an intraduodenal glucose at 3 kcal/min for 60 minutes. Venous blood was sampled every 15 minutes for measurements of blood glucose and plasma insulin, GLP-1 and GIP.. In response to intraduodenal glucose at 2 kcal/min, the incremental area under the curve between t = 0-60 minutes (iAUC0-60min) for blood glucose and plasma GIP did not differ between the 2 groups. However, iAUC0-60min for plasma GLP-1 (P = 0.016) and insulin (P = 0.011) were ∼2-fold higher in women than men. In response to intraduodenal glucose at 3 kcal/min, iAUC0-60min for blood glucose, plasma GIP, and insulin did not differ between women and men, but GLP-1 iAUC0-60min was 2.5-fold higher in women (P = 0.012).. Healthy young women exhibit comparable GIP but a markedly greater GLP-1 response to intraduodenal glucose than men. This disparity warrants further investigations to delineate the underlying mechanisms and may be of relevance to the reduced risk of diabetes in premenopausal women when compared to men. Topics: Blood Glucose; Diabetes Mellitus, Type 2; Female; Gastric Inhibitory Polypeptide; Glucagon-Like Peptide 1; Glucose; Humans; Incretins; Insulin; Male | 2023 |
Encapsulation and Assessment of Antidiabetic Potential of α-Lactalbumin-Derived Hydrolysates.
Dipeptidyl peptidase-IV (DPP-IV) is an exopeptidase mainly present in epithelial tissues of the liver, kidney, and intestine. It is involved in the cleavage of a variety of substrates including the incretin hormones like glucagon-like peptide-1 (GLP-1). GLP-1 binds to the GLP-1 receptors of pancreatic β-cells and leads to β-cell proliferation and increases insulin secretion through associated gene expression. In diabetes, a constant increase in the glucose level leads to glucotoxicity, which destroys pancreatic β-cells, decreases the insulin level, and further increases the blood glucose level. Inhibition of DPP-IV is one of the strategies for the treatment of type 2 diabetes. In recent years, peptides derived from a variety of dietary proteins have been reported to exhibit inhibitory activity against the DPP-IV enzyme. Such peptides should also be protected from the action of digestive enzymes to keep their bioactivity intact. Therefore, the present investigation was aimed to evaluate the in vitro DPP-IV inhibition potential and in vivo antidiabetic potential of α-lactalbumin in non-encapsulated hydrolysate (NEH), freeze-dried encapsulated hydrolysate (FDEH), and emulsified encapsulated hydrolysate (EEH) forms. Percent DPP-IV inhibition by the NEH, FDEH, and EEH after simulated gastrointestinal digestion was 36 ± 2.28, 54 ± 2.02, and 64 ± 2.02, respectively. The oral administration of the NEH, FDEH, and EEH at a dose of 300 mg/kg body weight was evaluated in nicotinamide-streptozotocin-induced type 2 diabetic experimental rats in a study of 30 days. Rats in the diabetic control group showed an increase in the blood glucose level and liver function enzymes and a decrease in GLP-1, insulin, and antioxidative enzymes. Administration of hydrolysates reversed the parameters by lowering the blood glucose level and increasing GLP-1 and insulin levels in plasma. The blood lipid profile, liver enzyme (ALT, AST, and AP) levels, and catalase and superoxide dismutase activity were also found to be normalized and better managed in experimental diabetic rats. Topics: Animals; Blood Glucose; Diabetes Mellitus, Experimental; Diabetes Mellitus, Type 2; Dipeptidyl-Peptidase IV Inhibitors; Glucagon-Like Peptide 1; Hypoglycemic Agents; Insulin; Lactalbumin; Peptides; Rats | 2023 |
Novel LC-MS/MS analysis of the GLP-1 analog semaglutide with its application to pharmacokinetics and brain distribution studies in rats.
Semaglutide, one of the most potent glucagon-like peptide (GLP)-1 analogs, has widely been used to treat type II diabetes mellitus and obesity. Recent studies have shown that semaglutide also works on the brain, suggesting its potential utility for various diseases, including Parkinson's disease and Alzheimer's disease. This study aimed to develop a novel liquid chromatography-tandem mass spectrometry (LC-MS/MS) analysis of semaglutide in both plasma and brain to characterize the pharmacokinetics and brain distribution in rats. Semaglutide was extracted by simple protein precipitation with methanol from plasma and by solid phase extraction from brain tissue. Liraglutide was used as an internal standard. Gradient elution profiles with mobile phases comprising 0.1 % formic acid in water and acetonitrile were used for chromatographic separation. The lower limit of quantification (LLOQ) of the LC-MS/MS assay was 0.5 ng/mL for both rat plasma and brain. Intra- and inter-day accuracy ranged 89.20-109.50 % in the plasma and 92.00-105.00 % in the brain. Precision was within 8.92 % in the plasma and 7.94 % in the brain. Sprague-Dawley rats were given semaglutide by intravenous (IV, 0.02 mg/kg) and subcutaneous (SC, 0.1 and 0.2 mg/kg) injection. Plasma concentrations of semaglutide showed a multi-exponential decline with an average half-life of 7.22-9.26 hr in rats. The subcutaneous bioavailability of semaglutide was 76.65-82.85 %. The brain tissue to plasma partition coefficient (K Topics: Animals; Brain; Chromatography, Liquid; Diabetes Mellitus, Type 2; Glucagon-Like Peptide 1; Rats; Rats, Sprague-Dawley; Reproducibility of Results; Tandem Mass Spectrometry | 2023 |
Dual effect of RYGB on the entero-insular axis: How GLP-1 is enhanced by surgical duodenal exclusion.
The role of the ileum and Glucagon Like Peptide-1 (GLP-1) secretion in the pathophysiological processes underlying the effects of Roux-en-Y gastric bypass (RYGB) on type 2 Diabetes mellitus (T2DM) improvement has been previously determined. However, the roles of duodenal exclusion and Glucose Insulinotropic Peptide (GIP) secretion change is not clear. To clarify this aspect, we compared the pathophysiological mechanisms triggered by RYGB, which implies the early arrival of food to the ileum with duodenal exclusion, and through pre-duodenal ileal transposition (PdIT), with early arrival of food to the ileum but without duodenal exclusion, in a nondiabetic rodent model.. We compared plasma and insulin, glucose (OGTT), GIP and GLP-1 plasma levels, ileal and duodenal GIP and GLP-1 tissue expression and beta-cell mass for n = 12 Sham-operated, n = 6 RYGB-operated, and n = 6 PdIT-operated Wistar rats.. No surgery induced changes in blood glucose levels after the OGTT. However, RYGB induced a significant and strong insulin response that increased less in PdIT animals. Increased beta-cell mass was found in RYGB and PdIT animals as well as similar GLP-1 secretion and GLP-1 intestinal expression. However, differential GIP secretion and GIP duodenal expression were found between RYGB and PdIT.. The RYGB effect on glucose metabolism is mostly due to early ileal stimulation; however, duodenal exclusion potentiates the ileal response within RYGB effects through enhanced GIP secretion. Topics: Animals; Blood Glucose; Diabetes Mellitus, Type 2; Gastric Bypass; Glucagon-Like Peptide 1; Glucose; Insulin; Rats; Rats, Wistar | 2023 |
Efficacy and safety of once-weekly efpeglenatide in people with suboptimally controlled type 2 diabetes: The AMPLITUDE-D, AMPLITUDE-L and AMPLITUDE-S randomized controlled trials.
To evaluate the efficacy and safety of once-weekly (QW) efpeglenatide in people with type 2 diabetes (T2D) suboptimally controlled with oral glucose-lowering drugs and/or basal insulin (BI).. Three phase 3, multicentre, randomized controlled trials compared the efficacy and safety of QW efpeglenatide versus dulaglutide when added to metformin (AMPLITUDE-D), efpeglenatide versus placebo when added to BI ± oral glucose-lowering drugs (AMPLITUDE-L) or metformin ± sulphonylurea (AMPLITUDE-S). All trials were terminated early by the sponsor because of funding rather than safety or efficacy concerns.. In AMPLITUDE-D, non-inferiority of efpeglenatide to dulaglutide 1.5 mg was shown in HbA1c reduction from baseline to week 56, least squares mean treatment difference (95% CI): 4 mg, -0.03% (-0.20%, 0.14%)/-0.35 mmol/mol (-2.20, 1.49); 6 mg, -0.08% (-0.25%, 0.09%)/-0.90 mmol/mol (-2.76, 0.96). The reductions in body weight (approximately 3 kg) from baseline to week 56 were similar across all treatment groups. In AMPLITUDE-L and AMPLITUDE-S, numerically greater reduction in HbA1c and body weight were observed at all doses of efpeglenatide than placebo. American Diabetes Association level 2 hypoglycaemia (< 54 mg/dL [< 3.0 mmol/L]) was reported in few participants across all treatment groups (AMPLITUDE-D, ≤ 1%; AMPLITUDE-L, ≤ 10%; and AMPLITUDE-S, ≤ 4%). The adverse events profile was consistent with other glucagon-like peptide-1 receptor agonists (GLP-1 RAs); gastrointestinal adverse events were most frequent in all three studies.. In people with T2D suboptimally controlled with oral glucose-lowering drugs and/or BI, QW efpeglenatide was non-inferior to dulaglutide in terms of HbA1c reduction and showed numerically greater improvements than placebo in glycaemic control and body weight, with safety consistent with the GLP-1 RA class. Topics: Blood Glucose; Body Weight; Diabetes Mellitus, Type 2; Glucagon-Like Peptide 1; Glucagon-Like Peptides; Glucose; Glycated Hemoglobin; Humans; Hypoglycemic Agents; Immunoglobulin Fc Fragments; Metformin; Randomized Controlled Trials as Topic; Recombinant Fusion Proteins; Treatment Outcome | 2023 |
Reduction of Plasma BCAAs following Roux-en-Y Gastric Bypass Surgery Is Primarily Mediated by FGF21.
Type 2 diabetes (T2D) is a challenging health concern worldwide. A lifestyle intervention to treat T2D is difficult to adhere, and the effectiveness of approved medications such as metformin, thiazolidinediones (TZDs), and sulfonylureas are suboptimal. On the other hand, bariatric procedures such as Roux-en-Y gastric bypass (RYGB) are being recognized for their remarkable ability to achieve diabetes remission, although the underlying mechanism is not clear. Recent evidence points to branched-chain amino acids (BCAAs) as a potential contributor to glucose impairment and insulin resistance. RYGB has been shown to effectively lower plasma BCAAs in insulin-resistant or T2D patients that may help improve glycemic control, but the underlying mechanism for BCAA reduction is not understood. Hence, we attempted to explore the mechanism by which RYGB reduces BCAAs. To this end, we randomized diet-induced obese (DIO) mice into three groups that underwent either sham or RYGB surgery or food restriction to match the weight of RYGB mice. We also included regular chow-diet-fed healthy mice as an additional control group. Here, we show that compared to sham surgery, RYGB in DIO mice markedly lowered serum BCAAs most likely by rescuing BCAA breakdown in both liver and white adipose tissues. Importantly, the restored BCAA metabolism following RYGB was independent of caloric intake. Fasting insulin and HOMA-IR were decreased as expected, and serum valine was strongly associated with insulin resistance. While gut hormones such as glucagon-like peptide-1 (GLP-1) and peptide YY (PYY) are postulated to mediate various surgery-induced metabolic benefits, mice lacking these hormonal signals (GLP-1R/Y2R double KO) were still able to effectively lower plasma BCAAs and improve glucose tolerance, similar to mice with intact GLP-1 and PYY signaling. On the other hand, mice deficient in fibroblast growth factor 21 (FGF21), another candidate hormone implicated in enhanced glucoregulatory action following RYGB, failed to decrease plasma BCAAs and normalize hepatic BCAA degradation following surgery. This is the first study using an animal model to successfully recapitulate the RYGB-led reduction of circulating BCAAs observed in humans. Our findings unmasked a critical role of FGF21 in mediating the rescue of BCAA metabolism following surgery. It would be interesting to explore the possibility of whether RYGB-induced improvement in glucose homeostasis is partly through decreased BCAAs. Topics: Amino Acids, Branched-Chain; Animals; Blood Glucose; Diabetes Mellitus, Type 2; Gastric Bypass; Glucagon-Like Peptide 1; Glucose; Humans; Insulin; Insulin Resistance; Mice; Obesity | 2023 |
Perspectives in weight control in diabetes - SGLT2 inhibitors and GLP-1-glucagon dual agonism.
Treatment of people with type 2 diabetes mellitus (T2D) and obesity should include glycemic control and sustained weight loss. However, organ protection and/or risk reduction for co-morbidities have also emerged as important goals. Here, we define this combined treatment approach as 'weight loss plus' and describe it as a metabolic concept where prolonged periods of energy consumption is central to outcomes. We suggest there are currently two drug classes - sodium-glucose cotransporter-2 inhibitors (SGLT2i) and glucagon-like peptide-1 (GLP-1)-glucagon dual agonists - that can facilitate this 'weight loss plus' approach. We describe evidence supporting that both classes address the underlying pathophysiology of T2D and facilitate normalization of metabolism through increased periods with a catabolic type of energy consumption, which effect other organ systems and may facilitate long-term cardio-renal benefits. These benefits have been demonstrated in trials of SGLT2is, and appear, to some degree, to be independent of glycemia and substantial weight loss. The combined effect of caloric restriction and metabolic correction facilitated by SGLT2i and GLP-1-glucagon dual agonists can be conceptualized as mimicking dietary restriction and physical activity, a phenomenon not previously observed with drugs whose benefits predominantly arise from absolute weight loss, and which may be key to achieving a 'weight loss plus' approach to treatment. Topics: Diabetes Mellitus, Type 2; Glucagon; Glucagon-Like Peptide 1; Glucagon-Like Peptide-1 Receptor; Humans; Hypoglycemic Agents; Sodium-Glucose Transporter 2 Inhibitors; Weight Loss | 2023 |
Is retatrutide (LY3437943), a GLP-1, GIP, and glucagon receptor agonist a step forward in the treatment of diabetes and obesity?
Despite there being a wide range of medicines available for the treatment of type 2 diabetes, the high rate of mortality suggests treatment needs to be improved. Only a few medicines have shown long-term effectiveness in obesity, and new medicines are urgently needed.. A multiple-ascending dose phase 1b clinical trial of a new drug retatrutide (LY3437943), which in addition to stimulating Glucagon-like peptide 1 (GLP-1) and Glucose-dependent insulinotropic polypeptide (GIP) receptors, stimulates glucagon receptors, in subjects with type 2 diabetes. Retatrutide was relatively safe and pharmacokinetics support once-weekly dosing.. The role of stimulating glucagon receptors in the treatment of type 2 diabetes and/or obesity is poorly defined and needs to be clarified. Although retatrutide may be superior to the GLP-1 receptor agonist dulaglutide in reducing plasma glucose and body weight, this is not a meaningful comparison, as another GLP-1 receptor agonist (semaglutide) is more potent than dulaglutide at this and may have similar efficacy to retatrutide. Retatrutide also needs to be compared to another Eli Lilly and Company drug, the combined GLP-1 and GIP receptor agonist, tirzepatide. The safety of retatrutide needs to be determined in larger and longer trials. Topics: Diabetes Mellitus, Type 2; Glucagon; Glucagon-Like Peptide 1; Glucagon-Like Peptide-1 Receptor; Humans; Hypoglycemic Agents; Obesity; Receptors, Glucagon | 2023 |
Designer GLP1 poly-agonist peptides in the management of diabesity.
To date, the 21. A PubMed search of published data on the GLP1PP class of therapies was conducted. The gut-brain axis forms complex multi-directional interlinks that include autonomic nervous signaling, components of the gut microbiota (including metabolic by-products and gram-negative cell wall components [e.g. endotoxinaemia]), and incretin hormones that are secreted from the gut in response to the ingestion of nutrients. The development of dual-incretin agonist therapies includes combinations of the GLP1 peptide with Glucose-dependent Insulinotropic Polypeptide (GIP), Glucagon (Gcg), Cholecystokinin (CCK), Peptide YY (PYY), and Glucagon-Like Peptide 2 (GLP2). Triple incretin agonist therapies are also under development.. At the dawn of a new era in the therapeutic management of diabesity, the designer GLP1PP class holds great promise, with each novel combination building on a preexisting palimpsest of clinical data and insights. Future innovations of the GLP1PP class will likely enable medically induced weight loss and glycemic control in diabesity to rival or even out-perform those resulting from bariatric surgery. Topics: Diabetes Mellitus, Type 2; Gastric Inhibitory Polypeptide; Glucagon; Glucagon-Like Peptide 1; Humans; Incretins | 2023 |
Design, synthesis, and biological evaluation of a potential long-acting glucagon-like peptide-1 (GLP-1) analog.
By binding to its receptor, glucagon-like peptide-1 (GLP-1) plays various physiological roles, including activating glucose-dependent insulin secretion, inhibiting gastric emptying, and reducing appetite. This suite of activities makes GLP-1 and its analogs an attractive choice for treating type 2 diabetes mellitus in the context of overweight or obesity. This study used different types and lengths of fatty acids to design dual fatty acid side chains for GLP-1 receptor agonists including decanoic, dodecanoic, tetradecanoic, hexadecanoic, dodecanedioic, tetradecanedioic, hexadecanedioic, and octadecanedioic acids. Sixteen GLP-1 receptor agonists (conjugates 13-28) with dual fatty acid side chains were obtained by liquid-phase synthesis. After structural confirmation using high-resolution mass spectrometry, peptide mapping, and circular dichroism, the biological activities of the conjugates were screened. First, the conjugates were screened for albumin binding and activity in GLP-1R-CRE-bla CHO-K1 cells. Albumin binding results suggested a synergistic effect between the two fatty acids in the conjugates. Next, conjugates 18, 19, and 21 selected after primary screening were assessed for receptor affinity, activity in INS-1 cells, plasma stability across different species, and efficacy and pharmacokinetics in normal and db/db mice. One candidate (conjugate 19) was found to have albumin binding of >99 %, good receptor affinity, activities of INS-1 cells, and plasma stability. We found that cellular activities in GLP-1R-CRE-bla CHO-K1 cells and pharmacodynamics and pharmacokinetics in normal and db/db mice for conjugate 19 were superior to those of semaglutide. Topics: Albumins; Animals; Cricetinae; Cricetulus; Diabetes Mellitus, Type 2; Glucagon-Like Peptide 1; Glucagon-Like Peptide-1 Receptor; Hypoglycemic Agents; Mice | 2023 |
[Obesity and type 2 diabetes (Update 2023)].
The body mass index (BMI) is a very crude measure of body fatness in individuals. Even normal weight persons can have too much body fat in cases of a lack of muscle mass (sarcopenia), which is why additional measurements of waist circumference and body fatness, e.g. bioimpedance analysis (BIA), are recommended. Lifestyle management including nutrition modification and increase in physical activity are important measures for the prevention and treatment of diabetes. Regarding the treatment of type 2 diabetes, body weight is increasingly used as a secondary target parameter. The choice of anti-diabetic treatment and additional concomitant therapies is increasingly influenced by body weight. The importance of modern GLP‑1 agonists and dual GLP‑1 GIP agonists increases since these drugs target obesity and type 2 diabetes. Bariatric surgery is at present indicated with a BMI > 35 kg/m. Der Body-Mass-Index (BMI) ist individuell betrachtet ein sehr grobes Maß für den Anteil des Körperfetts am Körpergewicht. Sogar Normalgewichtige können bei Muskelmangel zu viel Körperfett aufweisen (Sarkopenie), weswegen zusätzlich Messungen der Körperzusammensetzung (z. B. Bioimpedanzanalyse [BIA]) empfohlen werden. Lebensstilmanagement mit Ernährungsumstellung und Bewegung ist eine der wichtigsten Maßnahmen in der Diabetesprävention und -therapie. In der Therapie des Typ-2-Diabetes hat das Gewicht als sekundärer Zielparameter zunehmende Bedeutung erlangt. Auch die Wahl der antidiabetischen Therapie, aber auch der Begleittherapien nimmt immer mehr darauf Rücksicht. Die modernen GLP‑1 Analoga als auch der kombinierte GLP-1–GIP-Agonist Tirzepatid nehmen einen wichtigen Stellenwert in der gemeinsamen Behandlung von Adipositas und Diabetes mellitus Typ 2 ein. Die bariatrische Chirurgie ist derzeit bei an Diabetes mellitus Typ 2 erkrankten Menschen mit BMI > 35 kg/m Topics: Body Composition; Body Mass Index; Body Weight; Diabetes Mellitus, Type 2; Glucagon-Like Peptide 1; Humans; Obesity | 2023 |
[Diabetes mellitus and road traffic-a position paper of the Austrian Diabetes Association (update 2023)].
Public safety (prevention of accidents) is the primary objective in assessing fitness to drive a motor vehicle. However, general access to mobility should not be restricted if there is no particular risk to public safety. For people with diabetes mellitus, the Führerscheingesetz (Driving Licence Legislation) and the Führerscheingesetz-Gesundheitsverordnung (Driving Licence Legislation Health enactment) regulate important aspects of driving safety in connection with acute and chronic complications of the disease. Critical complications that may be relevant to road safety include severe hypoglycemia, pronounced hyperglycemia and hypoglycemia perception disorder as well as severe retinopathy and neuropathy, endstage renal disease and certain cardiovascular manifestations. If there is a suspicion of the presence of one of these complications, a detailed evaluation is required.In addition, the individual antihyperglycemic medication should be checked for existing potential for hypoglycemia. Sulfonylureas, glinides and insulin belong to this group and are therefore associated with the requirement of a 5-year limitation of the driver's license. Other antihyperglycemic drugs without potential for hypoglycemia such as Metformin, SGLT‑2 inhibitors (Sodium-dependent-glucose-transporter‑2 inhibitors, gliflozins), DPP-4-inhibitors (Dipeptidyl-Peptidase inhibitors, gliptins), and GLP‑1 analogues (GLP‑1 rezeptor agonists) are not associated with such a time limitation.The relevant laws which regulate driving safety give room for interpretation, so that specific topics on driving safety for people with diabetes mellitus are elaborated from a medical and traffic-relevant point of view. This position paper is intended to support people involved in this challenging matter.. Bei der Beurteilung der gesundheitlichen Eignung zum Lenken eines Kraftfahrzeuges ist die öffentliche Sicherheit (Unfallprävention) das vorrangige Ziel. Der generelle Zugang zu Mobilität sollte jedoch nicht eingeschränkt werden, wenn kein besonderes Risiko für die öffentliche Sicherheit besteht. Für Menschen mit Diabetes mellitus sind im Führerscheingesetz (FSG) und in der Führerscheingesetz-Gesundheitsversorgung (FSG-GV) wichtige Aspekte zur Fahrsicherheit in Zusammenhang mit akuten und chronischen Komplikationen der Erkrankung geregelt. Zu den kritischen Komplikationen, die für die Verkehrssicherheit relevant sind, gehören schwere Hypoglykämie, ausgeprägte Hyperglykämie und Hypoglykämiewahrnehmungsstörung, sowie schwere Retinopathie und Neuropathie, weiters fortgeschrittene Nierenerkrankung und bestimmte kardiovaskuläre Manifestationen. Bei Verdacht auf Präsenz einer dieser Akutkomplikationen oder Folgeschäden ist eine genaue Evaluierung erforderlich.Darüber hinaus ist die individuelle antihyperglykämische Medikation auf vorhandenes Potenzial für Hypoglykämien zu überprüfen. Sulfonylharnstoffe, Glinide und Insulin gehören in diese Gruppe und sind daher automatisch mit der Auflage einer 5‑jährigen Befristung des Führerscheines assoziiert. Metformin, DPP-4-Hemmer (Dipeptidyl-Peptidase-4-Hemmer, Gliptine), SGLT2-Hemmer (Sodium-dependent-glucose-transporter‑2 inhibitors, Gliflozine), Glitazone und die zu injizierenden GLP-1 Analoga (GLP‑1 Rezeptor Agonisten) weisen kein Hypoglykämiepotential auf und sind daher nicht mit einer Befristung verbunden.Die FSG-GV gibt Spielraum für Interpretation, sodass im Folgenden spezifische Themen zur Fahrsicherheit für Menschen mit Diabetes mellitus aus fachärztlicher und verkehrsrelevanter Sicht aufgearbeitet wurden. Dieses Positionspapier dient zur Unterstützung von Personen, die mit dieser herausfordernden Materie befasst sind. Topics: Accidents, Traffic; Austria; Automobile Driving; Diabetes Mellitus; Diabetes Mellitus, Type 2; Glucagon-Like Peptide 1; Humans; Hypoglycemia; Hypoglycemic Agents | 2023 |
Circulating levels of endothelial progenitor cells are associated with better cognitive function in older adults with glucagon-like peptide 1 receptor agonist-treated type 2 diabetes.
To evaluate cognitive function in subjects with type 2 diabetes (T2D) treated with glucagon-like peptide 1 receptor agonist (GLP-1RA) plus metformin or metformin alone and its association with endothelial progenitor cells (EPCs).. Adults with T2D treated with GLP-1RA plus metformin (GLP-1RA + MET) or MET alone for at least 12 months were included. Montreal Cognitive Assessment test (MoCA), Mini-Mental State Examination (MMSE), Mini Nutritional Assessment (MNA) and disability tests were administered. Circulating levels of seven EPCs phenotypes were measured by flow cytometry.. A total of 154 elderly patients were included, of whom 78 in GLP-1RA + MET group and 76 in MET group. The GLP-1RA + MET group showed better cognitive function as indicated by a significant higher MoCA and MMSE scores, and higher levels of CD34. People with T2D on GLP-1RA + MET treatment had better cognitive function and higher circulating levels of EPCs as compared with those on MET alone warranting further studies to understand the interrelationship between EPCs, GLP-RA treatment and cognitive health. Topics: Antigens, CD34; Cognition; Diabetes Mellitus, Type 2; Endothelial Progenitor Cells; Glucagon-Like Peptide 1; Glucagon-Like Peptide-1 Receptor; Humans; Hypoglycemic Agents; Metformin | 2023 |
Tirzepatide: A Dual Glucose-Dependent Insulinotropic Polypeptide and Glucagon-Like Peptide-1 Agonist for the Management of Type 2 Diabetes Mellitus: Erratum.
Topics: Diabetes Mellitus, Type 2; Gastric Inhibitory Polypeptide; Glucagon-Like Peptide 1; Glucagon-Like Peptide-1 Receptor; Glucose; Humans; Hypoglycemic Agents | 2023 |
Insulin secretory actions of ethanolic extract of Acacia arabica bark in high fat-fed diet-induced obese Type 2 diabetic rats.
Acacia arabica commonly known as 'babul' has been widely used for the treatment of numerous diseases, including diabetes due to their potential pharmacological actions. The aim of the present study was to investigate the insulinotropic and antidiabetic properties of ethanol extract of Acacia arabica (EEAA) bark through in vitro and in vivo studies in high fat-fed (HFF) rats. EEAA at 40-5000 µg/ml significantly increased (P<0.05-0.001) insulin secretion with 5.6 and 16.7 mM glucose, respectively, from clonal pancreatic BRIN BD11 β-cells. Similarly, EEAA at 10-40 µg/ml demonstrated a substantial (P<0.05-0.001) insulin secretory effect with 16.7 mM glucose from isolated mouse islets, with a magnitude comparable to 1 µM glucagon-like peptide-1 (GLP-1). Diazoxide, verapamil, and calcium-free conditions decreased insulin secretion by 25-26%. The insulin secretory effect was further potentiated (P<0.05-0.01) with 200 µM isobutylmethylxanthine (IBMX; 1.5-fold), 200 µM tolbutamide (1.4-fold), and 30 mM KCl (1.4-fold). EEAA at 40 µg/ml, induced membrane depolarization and elevated intracellular Ca2+ as well as increased (P<0.05-0.001) glucose uptake in 3T3L1 cells and inhibited starch digestion, glucose diffusion, dipeptidyl peptidase-IV (DPP-IV) enzyme activity, and protein glycation by 15-38%, 11-29%, 15-64%, and 21-38% (P<0.05, 0.001), respectively. In HFF rats, EEAA (250 mg/5 ml/kg) improved glucose tolerance, plasma insulin, and GLP-1 levels, and lowered DPP-IV enzyme activity. Phytochemical screening of EEAA revealed the presence of flavonoids, tannins and anthraquinone. These naturally occurring phytoconstituents may contribute to the potential antidiabetic actions of EEAA. Thus, our finding suggests that EEAA, as a good source of antidiabetic constituents, would be beneficial for Type 2 diabetes patients. Topics: Acacia; Animals; Blood Glucose; Diabetes Mellitus, Experimental; Diabetes Mellitus, Type 2; Diet; Dipeptidyl Peptidase 4; Ethanol; Glucagon-Like Peptide 1; Glucose; Hypoglycemic Agents; Insulin; Insulin Secretion; Mice; Obesity; Plant Bark; Rats | 2023 |
Divergent acute versus prolonged pharmacological GLP-1R responses in adult β cell-specific β-arrestin 2 knockout mice.
The glucagon-like peptide-1 receptor (GLP-1R) is a major type 2 diabetes therapeutic target. Stimulated GLP-1Rs are rapidly desensitized by β-arrestins, scaffolding proteins that not only terminate G protein interactions but also act as independent signaling mediators. Here, we have assessed in vivo glycemic responses to the pharmacological GLP-1R agonist exendin-4 in adult β cell-specific β-arrestin 2 knockout (KO) mice. KOs displayed a sex-dimorphic phenotype consisting of weaker acute responses that improved 6 hours after agonist injection. Similar effects were observed for semaglutide and tirzepatide but not with biased agonist exendin-phe1. Acute cyclic adenosine 5'-monophosphate increases were impaired, but desensitization reduced in KO islets. The former defect was attributed to enhanced β-arrestin 1 and phosphodiesterase 4 activities, while reduced desensitization co-occurred with impaired GLP-1R recycling and lysosomal targeting, increased trans-Golgi network signaling, and reduced GLP-1R ubiquitination. This study has unveiled fundamental aspects of GLP-1R response regulation with direct application to the rational design of GLP-1R-targeting therapeutics. Topics: Animals; beta-Arrestin 2; Diabetes Mellitus, Type 2; Glucagon-Like Peptide 1; Glucagon-Like Peptide-1 Receptor; Mice; Mice, Knockout | 2023 |
Glucagon-like peptide 1 aggregates into low-molecular-weight oligomers off-pathway to fibrillation.
The physical stability of peptide-based drugs is of great interest to the pharmaceutical industry. Glucagon-like peptide 1 (GLP-1) is a 31-amino acid peptide hormone, the analogs of which are frequently used in the treatment of type 2 diabetes. We investigated the physical stability of GLP-1 and its C-terminal amide derivative, GLP-1-Am, both of which aggregate into amyloid fibrils. While off-pathway oligomers have been proposed to explain the unusual aggregation kinetics observed previously for GLP-1 under specific conditions, these oligomers have not been studied in any detail. Such states are important as they may represent potential sources of cytotoxicity and immunogenicity. Here, we identified and isolated stable, low-molecular-weight oligomers of GLP-1 and GLP-1-Am, using size-exclusion chromatography. Under the conditions studied, isolated oligomers were shown to be resistant to fibrillation or dissociation. These oligomers contain between two and five polypeptide chains and they have a highly disordered structure as indicated by a variety of spectroscopic techniques. They are highly stable with respect to time, temperature, or agitation despite their noncovalent character, which was established using liquid chromatography-mass spectrometry and sodium dodecyl sulfate-polyacrylamide gel electrophoresis. These results provide evidence of stable, low-molecular-weight oligomers that are formed by an off-pathway mechanism which competes with amyloid fibril formation. Topics: Amyloid; Amyloid beta-Peptides; Chromatography, Gel; Diabetes Mellitus, Type 2; Glucagon-Like Peptide 1; Humans; Peptide Fragments; Peptides | 2023 |
Glucagon-like peptide-1 receptor agonists to expand the healthy lifespan: Current and future potentials.
To help ensure an expanded healthy lifespan for as many people as possible worldwide, there is a need to prevent or manage a number of prevalent chronic diseases directly and indirectly closely related to aging, including diabetes and obesity. Glucagon-like peptide 1 receptor agonists (GLP-1 RAs) have proven beneficial in type 2 diabetes, are amongst the few medicines approved for weight management, and are also licensed for focused cardiovascular risk reduction. In addition, strong evidence suggests several other beneficial effects of the pleiotropic peptide hormone, including anti-inflammation. Consequently, GLP-1 RAs are now in advanced clinical development for the treatment of chronic kidney disease, broader cardiovascular risk reduction, metabolic liver disease and Alzheimer's disease. In sum, GLP-1 RAs are positioned as one of the pharmacotherapeutic options that can contribute to addressing the high unmet medical need characterising several prevalent aging-related diseases, potentially helping more people enjoy a prolonged healthy lifespan. Topics: Diabetes Mellitus, Type 2; Glucagon-Like Peptide 1; Glucagon-Like Peptide-1 Receptor; Humans; Hypoglycemic Agents; Longevity | 2023 |
Rare Heterozygous Loss-of-Function Variants in the Human GLP-1 Receptor Are Not Associated With Cardiometabolic Phenotypes.
Lost glucagon-like peptide 1 receptor (GLP-1R) function affects human physiology.. This work aimed to identify coding nonsynonymous GLP1R variants in Danish individuals to link their in vitro phenotypes and clinical phenotypic associations.. We sequenced GLP1R in 8642 Danish individuals with type 2 diabetes or normal glucose tolerance and examined the ability of nonsynonymous variants to bind GLP-1 and to signal in transfected cells via cyclic adenosine monophosphate (cAMP) formation and β-arrestin recruitment. We performed a cross-sectional study between the burden of loss-of-signaling (LoS) variants and cardiometabolic phenotypes in 2930 patients with type 2 diabetes and 5712 participants in a population-based cohort. Furthermore, we studied the association between cardiometabolic phenotypes and the burden of the LoS variants and 60 partly overlapping predicted loss-of-function (pLoF) GLP1R variants found in 330 566 unrelated White exome-sequenced participants in the UK Biobank cohort.. We identified 36 nonsynonymous variants in GLP1R, of which 10 had a statistically significant loss in GLP-1-induced cAMP signaling compared to wild-type. However, no association was observed between the LoS variants and type 2 diabetes, although LoS variant carriers had a minor increased fasting plasma glucose level. Moreover, pLoF variants from the UK Biobank also did not reveal substantial cardiometabolic associations, despite a small effect on glycated hemoglobin A1c.. Since no homozygous LoS nor pLoF variants were identified and heterozygous carriers had similar cardiometabolic phenotype as noncarriers, we conclude that GLP-1R may be of particular importance in human physiology, due to a potential evolutionary intolerance of harmful homozygous GLP1R variants. Topics: Cardiovascular Diseases; Cross-Sectional Studies; Diabetes Mellitus, Type 2; Glucagon-Like Peptide 1; Glucagon-Like Peptide-1 Receptor; Humans; Phenotype | 2023 |
In Vitro Screening for Probiotic Properties of
Non-alcoholic fatty liver disease (NAFLD) is a multifactorial metabolic disorder that poses health challenges worldwide and is expected to continue to rise dramatically. NAFLD is associated with metabolic syndrome, type 2 diabetes mellitus, and impaired gut health. Increased gut permeability, caused by disturbance of tight junction proteins, allows passage of damaging microbial components that, upon reaching the liver, have been proposed to trigger the release of inflammatory cytokines and generate cellular stress. A growing body of research has suggested the utilization of targeted probiotic supplements as a preventive therapy to improve gut barrier function and tight junctions. Furthermore, specific microbial interactions and metabolites induce the secretion of hormones such as GLP-1, resulting in beneficial effects on liver health. To increase the likelihood of finding beneficial probiotic strains, we set up a novel screening platform consisting of multiple in vitro and ex vivo assays for the screening of 42 bacterial strains. Analysis of transepithelial electrical resistance response via co-incubation of the 42 bacterial strains with human colonic cells (Caco-2) revealed improved barrier integrity. Then, strain-individual metabolome profiling was performed revealing species-specific clusters. GLP-1 secretion assay with intestinal secretin tumor cell line (STC-1) found at least seven of the strains tested capable of enhancing GLP-1 secretion in vitro. Gene expression profiling in human biopsy-derived intestinal organoids was performed using next generation sequencing transcriptomics post bacterial co-incubation. Here, different degrees of immunomodulation by the increase in certain cytokine and chemokine transcripts were found. Treatment of mouse primary hepatocytes with selected highly produced bacterial metabolites revealed that indole metabolites robustly inhibited de novo lipogenesis. Collectively, through our comprehensive bacterial screening pipeline, not previously ascribed strains from both Lactobacillus and Bifidobacterium genera were proposed as potential probiotics based on their ability to increase epithelial barrier integrity and immunity, promote GLP-1 secretion, and produce metabolites relevant to liver health. Topics: Animals; Bifidobacterium; Caco-2 Cells; Cytokines; Diabetes Mellitus, Type 2; Glucagon-Like Peptide 1; Humans; Lactobacillus; Mice; Non-alcoholic Fatty Liver Disease; Probiotics | 2023 |
Acute pharmacodynamic responses to exenatide: Drug-induced increases in insulin secretion and glucose effectiveness.
Glucagon-like peptide-1 receptor agonists provide multiple benefits to patients with type 2 diabetes, including improved glycaemic control, weight loss and decreased risk of major adverse cardiovascular events. Because drug responses vary among individuals, we initiated investigations to identify genetic variants associated with the magnitude of drug responses.. Exenatide (5 μg, subcutaneously) or saline (0.2 ml, subcutaneously) was administered to 62 healthy volunteers. Frequently sampled intravenous glucose tolerance tests were conducted to assess the impact of exenatide on insulin secretion and insulin action. This pilot study was a crossover design in which participants received exenatide and saline in random order.. Exenatide increased first phase insulin secretion 1.9-fold (p = 1.9 × 10. This pilot study provides validation for the value of a frequently sampled intravenous glucose tolerance test (including minimal model analysis) to provide primary data for our ongoing pharmacogenomic study of pharmacodynamic effects of semaglutide (NCT05071898). Three endpoints provide quantitative assessments of the effects of glucagon-like peptide-1 receptor agonists on glucose metabolism: first phase insulin secretion, glucose disappearance rates and glucose effectiveness. Topics: Blood Glucose; Diabetes Mellitus, Type 2; Exenatide; Glucagon-Like Peptide 1; Glucagon-Like Peptide-1 Receptor; Glucose; Humans; Hypoglycemic Agents; Insulin; Insulin Secretion; Peptides; Pilot Projects; Venoms | 2023 |
Prescribing trends of glucose-lowering drugs in older adults from 2010 to 2021: A population-based study of Northern Italy.
To describe glucose-lowering drugs prescribing pattern in a large population of older diabetics from 2010 to 2021.. Using linkable administrative health databases, we included patients aged 65-90 years treated with glucose-lowering drugs. Prevalence rate of drugs was collected within each study year. A stratified analysis by gender, age and coexistence of cardiovascular disease (CVD) was conducted.. A total of 251 737 and 308 372 patients were identified in 2010 and 2021, respectively. Use of metformin (68.4% to 76.6%), DPP-4i (1.6% to 18.4%), GLP-1-RA (0.4% to 10.2%), SGLT2i (0.6% to 11.1%) increased, while sulfonylureas (53.6% to 20.7%) and glinides (10.5% to 3.5%) decreased over time. Metformin, glitazones, GLP1-RA, SGLT2i and DPP4i (except for 2021) usage decreased with aging, in contrast to sulfonylureas, glinides and insulin. The coexistence of CVD was associated with a higher prescription of glinides, insulin, DPP-4i, GLP1-RA and SGLT2i, particularly in 2021.. We found a significant increase in the prescriptions of GLP-1 RA and SGLT2i in older diabetics, mainly in those with CVD. However, drugs without CV benefits including sulfonylureas and DPP-4i continued to be highly prescribed in older patients. There is still room to improve the management in this population according to recommendations. Topics: Aged; Cardiovascular Diseases; Diabetes Mellitus, Type 2; Dipeptidyl-Peptidase IV Inhibitors; Glucagon-Like Peptide 1; Glucagon-Like Peptide-1 Receptor; Glucose; Humans; Hypoglycemic Agents; Insulin; Insulin, Regular, Human; Metformin; Sodium-Glucose Transporter 2 Inhibitors; Sulfonylurea Compounds | 2023 |
Regurgitation under anesthesia in a fasted patient prescribed semaglutide for weight loss: a case report.
Glucagon-like peptide-1 receptor agonists (GLP-1 RAs) such as semaglutide are a class of medications prescribed to treat type 2 diabetes mellitus, and more recently, as an adjunct for weight loss because of its effects of delaying gastric emptying and suppressing appetite. Semaglutide is a long-acting agent with a half-life of approximately one week, and there are currently no guidelines that address the perioperative management of such agents.. We describe an unexpected case of regurgitation of a large volume of gastric contents upon induction of general anesthesia in a nondiabetic, nonobese patient despite a long preoperative fasting period (20 hr for solids and eight hours for clear fluids). This patient had no traditional risk factors for regurgitation or aspiration but was taking the GLP-1 RA semaglutide for weight loss and had last taken the medication two days before their scheduled procedure.. Patients taking long-acting GLP-1 RAs such as semaglutide may be at risk of pulmonary aspiration under anesthesia. We propose strategies to mitigate this risk including holding the medication four weeks prior to a scheduled procedure when feasible and considering full stomach precautions.. RéSUMé: OBJECTIF: Les agonistes des récepteurs du glucagon-like peptide-1 (AR GLP-1) tels que le sémaglutide sont une classe de médicaments prescrits pour traiter le diabète sucré de type 2 et, plus récemment, comme complément à la perte de poids en raison de ses effets de retardement de la vidange gastrique et de suppression de l’appétit. Le sémaglutide est un agent à action prolongée dont la demi-vie est d’environ une semaine, et il n’existe actuellement aucune ligne directrice traitant de la prise en charge périopératoire de ces agents. CARACTéRISTIQUES CLINIQUES: Nous décrivons un cas inattendu de régurgitation d’un important volume de contenu gastrique lors de l’induction de l’anesthésie générale chez une personne non diabétique et non obèse malgré une longue période de jeûne préopératoire (20 heures pour les solides et huit heures pour les liquides clairs). Cette personne ne présentait aucun facteur de risque traditionnel de régurgitation ou d’aspiration, mais prenait du sémaglutide (AR GLP-1) à des fins de perte de poids et avait pris le médicament pour la dernière fois deux jours avant l’intervention prévue. CONCLUSION: Les patient·es prenant des AR GLP-1 à action prolongée tels que le sémaglutide peuvent être à risque d’aspiration pulmonaire sous anesthésie. Nous proposons des stratégies pour atténuer ce risque, y compris d’interrompre la prise du médicament quatre semaines avant une intervention prévue lorsque cela est possible et d’envisager de prendre les précautions requises pour un estomac plein. Topics: Anesthesia, General; Diabetes Mellitus, Type 2; Fasting; Glucagon-Like Peptide 1; Glucagon-Like Peptide-1 Receptor; Humans; Hypoglycemic Agents; Weight Loss | 2023 |
Dosing Patterns of Dulaglutide and Semaglutide in Patients with Type 2 Diabetes in the United Kingdom and Germany: A Retrospective Cohort Study.
As new glucagon-like peptide 1 receptor agonist (GLP-1 RA) formulations are available, the aim of this study was to understand dulaglutide and subcutaneous (s.c.) semaglutide dosing patterns in people with type 2 diabetes mellitus (T2DM) in the UK and Germany as well as oral semaglutide in the UK.. Adults with evidence of T2DM and a prescription of dulaglutide or semaglutide between August 2020 and December 2021 were identified using the IQVIA Longitudinal Prescription Data (LRx). Patients were divided into cohort 1 (incident users) and cohort 2 (prevalent users) based on previous exposure to GLP-1 RAs and were followed up to 12 months post-index.. During the patient selection window in Germany and the UK, 368,320 and 123,548 patients respectively received at least one prescription of a study GLP-1 RA. Among dulaglutide users in Germany at 12 months post-index, the 1.5-mg dosage formulation was the most common for both cohort 1 (65.6%) and 2 (71.2%). Among s.c. semaglutide users at 12 months post-index, 39.2% and 58.4% of cohort 1 received 0.5 mg and 1.0 mg, respectively. In the UK, at 12 months post-index, the most common dulaglutide dosage formulation was 1.5 mg (71.7% cohort 1 and 80.9% cohort 2). Among s.c. semaglutide users at 12 months post-index, 0.5- and 1.0-mg formulations were the most common for both cohort 1 (38.9% and 56.0%, respectively) and cohort 2 (29.5% and 67.1%, respectively). Prescribing of the more recently introduced 3.0- and 4.5-mg formulations for dulaglutide and oral semaglutide was also reported in the study.. Dosing patterns of GLP-1 RAs, although similar between the UK and Germany, were heterogeneous over time. Given that the higher dulaglutide doses and oral semaglutide were recently introduced to the market, additional real-world evidence studies which include clinical outcomes is required. Topics: Adult; Diabetes Mellitus, Type 2; Glucagon-Like Peptide 1; Glucagon-Like Peptides; Humans; Hypoglycemic Agents; Retrospective Studies; United Kingdom | 2023 |
Evaluation of Out-of-Pocket Costs and Treatment Intensification With an SGLT2 Inhibitor or GLP-1 RA in Patients With Type 2 Diabetes and Cardiovascular Disease.
The latest guidelines continue to recommend sodium-glucose cotransporter 2 (SGLT2) inhibitors and glucagon-like peptide-1 receptor agonists (GLP-1 RAs) for patients with type 2 diabetes (T2D) and established cardiovascular disease (CVD). Despite this, overall use of these 2 drug classes has been suboptimal.. To assess the association of high out-of-pocket (OOP) costs and the initiation of an SGLT2 inhibitor or GLP-1 RA among adults with T2D and established CVD who are treated with metformin-treated.. This retrospective cohort study used 2017 to 2021 data from the Optum deidentified Clinformatics Data Mart Database. Each individual in the cohort was categorized into quartiles of OOP costs for a 1-month supply of SGLT2 inhibitor and GLP-1 RA based on their health plan assignment. Data were analyzed from April 2021 to October 2022.. OOP cost for SGLT2 inhibitors and GLP-1 RA.. The primary outcome was treatment intensification, defined as a new dispensing (ie, initiation) of either an SGLT2 inhibitor or GLP-1 RA, among patients with T2D previously treated with metformin monotherapy. For each drug class separately, Cox proportional hazards models were used to adjust for demographic, clinical, plan, clinician, and laboratory characteristics to estimate the hazard ratios of treatment intensification comparing the highest vs the lowest quartile of OOP costs.. Our cohort included 80 807 adult patients (mean [SD] age, 72 [9.5] years, 45 129 [55.8%] male; 71 128 [88%] were insured with Medicare Advantage) with T2D and established CVD on metformin monotherapy. Patients were followed for a median (IQR) of 1080 days (528 to 1337). The mean (SD) of OOP costs in the highest vs lowest quartile was $118 [32] vs $25 [12] for GLP-1 RA, and $91 [25] vs $23 [9] for SGLT2 inhibitors. Compared with patients in plans with the lowest quartile (Q1) of OOP costs, patients in plans with the highest quartile (Q4) of costs were less likely to initiate a GLP-1 RA (adjusted HR, 0.87 [95% CI, 0.78 to 0.97]) or an SGLT2 inhibitor (adjusted HR, 0.80 [95% CI, 0.73 to 0.88]). The median (IQR) number of days to initiating a GLP-1 RA was 481 (207-820) days in Q1 and 556 (237-917) days in Q4 of OOP costs and 520 (193-876) days in Q1 vs 685 (309-1017) days in Q4 for SGLT2 inhibitors.. In this cohort study of more than 80 000 older adults with T2D and established CVD covered by Medicare Advantage and commercial plans, those in the highest quartile of OOP cost were 13% and 20% less likely to initiate a GLP-1 RA or SGLT2 inhibitor, respectively, when compared with those in the lowest quartile of OOP costs. Topics: Aged; Cardiovascular Diseases; Cohort Studies; Diabetes Mellitus, Type 2; Female; Glucagon-Like Peptide 1; Health Expenditures; Humans; Male; Medicare; Metformin; Retrospective Studies; Sodium-Glucose Transporter 2 Inhibitors; United States | 2023 |
The novel GIP, GLP-1 and glucagon receptor agonist retatrutide delays gastric emptying.
Topics: Blood Glucose; Diabetes Mellitus, Type 2; Gastric Emptying; Gastric Inhibitory Polypeptide; Glucagon; Glucagon-Like Peptide 1; Glucagon-Like Peptide-1 Receptor; Humans; Insulin; Receptors, Glucagon | 2023 |
Treatment sequencing using the dual amylin and calcitonin receptor agonist KBP-336 and semaglutide results in durable weight loss.
Long-acting dual amylin and calcitonin receptor agonists (DACRAs) hold great promise as potential treatments for obesity and its associated comorbidities. These agents have demonstrated beneficial effects on body weight, glucose control, and insulin action mirroring the effects observed with glucagon-like peptide-1 (GLP-1) agonist treatment. Strategies aimed at enhancing and prolonging treatment efficacy include treatment sequencing and combination therapy. Here, we sought to investigate the impact of switching between or combining treatment with the DACRA KBP-336 and the GLP-1 analog semaglutide in fed rats with obesity induced by a high-fat diet (HFD).. Two studies were performed in which HFD-induced obese Sprague Dawley rats were switched between treatment with KBP-336 (4.5 nmol/kg, Q3D) and semaglutide (50 nmol/kg, Q3D) or a combination of the two. Treatment efficacy on weight loss and food intake was evaluated, and glucose tolerance was assessed by oral glucose tolerance tests.. KBP-336 and semaglutide monotherapy resulted in a similar reduction in body weight and food intake. Treatment sequencing resulted in continuous weight loss and all monotherapies resulted in similar weight loss independent of the treatment regimen (P < 0.001 compared to vehicle). The combination of KBP-336 and semaglutide significantly improved the weight loss compared to either monotherapy alone (P < 0.001), which was evident in the adiposity at the study end. All treatments improved glucose tolerance, with the KBP-effect on insulin sensitivity as the dominant response.. These findings highlight KBP-336 as a promising anti-obesity therapy both alone, in treatment sequencing, and in combination with semaglutide or other incretin-based therapies. Topics: Amylin Receptor Agonists; Animals; Body Weight; Bone Density Conservation Agents; Diabetes Mellitus, Type 2; Glucagon-Like Peptide 1; Glucagon-Like Peptide-1 Receptor; Glucose; Hypoglycemic Agents; Islet Amyloid Polypeptide; Obesity; Rats; Rats, Sprague-Dawley; Receptors, Calcitonin; Weight Loss | 2023 |
CCK and GLP-1 response on enteroendocrine cells of semi-dynamic digests of hydrolyzed and intact casein.
A semi-dynamic gastrointestinal device was employed to explore the link between protein structure and metabolic response upon digestion for two different substrates, a casein hydrolysate and the precursor micellar casein. As expected, casein formed a firm coagulum that remained until the end of the gastric phase while the hydrolysate did not develop any visible aggregate. Each gastric emptying point was subjected to a static intestinal phase where the peptide and amino acid composition changed drastically from that found during the gastric phase. Gastrointestinal digests from the hydrolysate were characterized by a high abundancy of resistant peptides and free amino acids. Although all gastric and intestinal digests from both substrates induced the secretion of cholecystokinin (CCK) and glucagon-like peptide-1 (GLP-1) in STC-1 cells, GLP-1 levels were maximum in response to gastrointestinal digests from the hydrolysate. The enrichment of protein ingredients with gastric-resistant peptides by enzymatic hydrolysis is proposed as strategy to deliver protein stimuli to the distal gastrointestinal tract to control food intake or type 2 diabetes. Topics: Caseins; Cholecystokinin; Diabetes Mellitus, Type 2; Enteroendocrine Cells; Glucagon-Like Peptide 1; Humans; Peptides | 2023 |
GLP-1 agonists for people living with HIV and obesity, is there a potential?
Obesity trends and metabolic dysregulation are rising in people living with HIV using antiretrovirals (ARVs). Underlying causes and preventive strategies are being investigated. Two glucagon like-peptide 1 (GLP-1) agonists, liraglutide and semaglutide, were formerly approved as glucose-lowering drugs and have been recently approved for long-term weight loss in people with obesity. Due to the lack of therapeutic guidelines or clinical trials in people with HIV, we discuss the potential benefits, safety aspects and pharmacological considerations of prescribing liraglutide and semaglutide in people with HIV.. Clinical experience is limited to two clinical cases of diabetic people with HIV using liraglutide after which a successful weight loss and glycaemic control were observed. None of the adverse events associated with liraglutide and semaglutide usage indicate an additional risk for people with HIV. Extra caution showed be warranted when initiating GLP-1 agonist therapy in people with HIV taking protease inhibitors who have pre-existing risk factors for heart rate variability to reduce the incidence of RP interval prolongation. GLP-1 agonists are metabolized by endopeptidases, and thus do not generate major drug-drug interactions with most drugs, including ARVs. GLP-s agonists are known to inhibit gastric acid secretion, which warrants caution and close monitoring when combined with atazanavir and oral rilpivirine, two ARVs that require low gastric pH for an optimal absorption.. Theoretical considerations and a few available clinical observations support semaglutide and liraglutide prescription in people with HIV, with, thus far, no indications of concern regarding efficacy, safety or pharmacological interactions with ARVs. Topics: Diabetes Mellitus, Type 2; Glucagon-Like Peptide 1; HIV Infections; Humans; Hypoglycemic Agents; Liraglutide; Obesity; Weight Loss | 2023 |
Effect of dipeptidyl peptidase-4 inhibitors on glycated hemoglobin levels relies on dietary sodium intake.
Sodium load increases endogenous glucagon-like peptide-1 (GLP-1) levels in humans. Therefore, patients with an increased amount of dietary sodium intake are supposed to have higher endogenous GLP-1 levels compared to those with less dietary sodium intake. Therefore, it can be hypothesized that patients with type 2 diabetes mellitus (T2DM) with more dietary sodium intake show better dipeptidyl peptidase-4 inhibitor (DPP-4i) effect on glycemic control because of the expected higher GLP-1 level. Thus, we performed a single-center cohort study to explore this idea.. Medical records of patients with T2DM prescribed DPP-4i in the last 11 years were investigated. Dietary sodium intake was measured before the DPP-4i prescription with Tanaka's formula using casual spot urine samples. The effect of DPP-4i on glycemic control was estimated by the subtraction of glycated hemoglobin (HbA1c) before DPP-4i initiation from HbA1c 1 year after DPP-4i administration. We analyzed 50 patients.. DPP-4i improved HbA1c by -0.41% ± 0.66%. The effect of DPP-4i on glycemic control was significantly negatively correlated with the dietary sodium intake (r = -0.400). Thus, the more dietary sodium intake, the better the glycemic control by DPP-4i.. Thus, patients can expect better plasma glucose control by DPP-4is if patients are taking increased dietary sodium intake. Topics: Cohort Studies; Diabetes Mellitus, Type 2; Dipeptidyl-Peptidase IV Inhibitors; Dipeptidyl-Peptidases and Tripeptidyl-Peptidases; Glucagon-Like Peptide 1; Glycated Hemoglobin; Humans; Hypoglycemic Agents; Sodium, Dietary | 2023 |
A new class of glucose-lowering therapy for type 2 diabetes: the latest development in the incretin arena.
Topics: Blood Glucose; Diabetes Mellitus, Type 2; Glucagon-Like Peptide 1; Glucose; Humans; Hypoglycemic Agents; Incretins; Insulin | 2023 |
Glucagon-like peptide-1 treatment reduces the risk of diabetes-type 2 related amputations: A cohort study in Denmark.
To assess the impact of Glucagon-like peptide-1 (GLP-1) agonists on the risk of lower extremity amputations in patients with type 2 diabetes mellitus (DM2).. We conducted a cohort study on 309,116 patients with DM2 using Danish National Register and Diabetes Database. We tracked the GLP-1 agonists over time along with the medication dose. Time-varying models are used to assess the risk of amputation for patients with/without GLP-1 treatment.. Patients on GLP-1 treatment experience a notable reduction in the risk of amputation compared to those without the treatment with a hazard ratio (HR) of 0.5, 95% CI [0.54-0.74], indicating a statistically significant difference (p <.005). This risk reduction was consistent across different age groups, but notably most pronounced among middle income patients. The findings were further validated by using time-varying Cox models, which considered the patient's comorbidity history.. Our analysis reveals compelling evidence of a reduced risk of amputation among patients receiving GLP-1 therapy, an effect dominated by liraglutide, compared to those without the treatment, even after adjusting for various socio-economic factors. However, further investigation is required to identify and account for any other potential confounding variables that may impact the outcome. Topics: Amputation, Surgical; Cohort Studies; Denmark; Diabetes Mellitus, Type 2; Glucagon-Like Peptide 1; Glucagon-Like Peptide-1 Receptor; Humans; Hypoglycemic Agents | 2023 |
Semaglutide versus tirzepatide for people with type 2 diabetes: cost of glycemic control in Austria, the Netherlands, Lithuania, and the United Arab Emirates.
The glucagon-like peptide-1 agonist semaglutide and the dual glucose-dependent insulinotropic polypeptide tirzepatide have proven to significantly reduce glucose levels in people with type 2 diabetes. However, the costs needed to achieve a sustained decrease in HbA1c level and disease control with semaglutide and tirzepatide, respectively, are unclear. Therefore, this study aimed to compare the cost of treatment with semaglutide with the cost of treatment with tirzepatide for type 2 diabetes in Austria, the Netherlands, Lithuania, and the United Arab Emirates in order to determine their respective value for money.. The primary outcome of this analysis was the cost in euros needed to achieve disease control in one person with type 2 diabetes based on the composite endpoint of HbA1c <7%, ≥5% weight loss, and no hypoglycemic events. In addition, analyses regarding the cost needed to reach relevant HbA1c endpoints were performed. Clinical data were obtained from the SURPASS 2 trial, registered at clinicaltrials.gov (NCT03987919), and drug cost was based on wholesale acquisition cost or pharmacy purchase prices from public domains obtained in Q1 of 2023.. The cost needed to achieve disease control in one person with type 2 diabetes (HbA1c <7%, ≥5% weight loss, and no hypoglycemic events) was up to three times lower using semaglutide compared with all three doses of tirzepatide in most markets. In the HbA1c analyses, semaglutide was also found to be the least expensive treatment option.. Semaglutide provides better value for money than tirzepatide for HbA1c-lowering endpoints. Topics: Austria; Diabetes Mellitus, Type 2; Glucagon-Like Peptide 1; Glucose; Glycated Hemoglobin; Glycemic Control; Humans; Hypoglycemic Agents; Lithuania; Netherlands; United Arab Emirates; Weight Loss | 2023 |
A model-based approach to predict individual weight loss with semaglutide in people with overweight or obesity.
To determine the relationship between exposure and weight-loss trajectories for the glucagon-like peptide-1 analogue semaglutide for weight management.. Data from one 52-week, phase 2, dose-ranging trial (once-daily subcutaneous semaglutide 0.05-0.4 mg) and two 68-week phase 3 trials (once-weekly subcutaneous semaglutide 2.4 mg) for weight management in people with overweight or obesity with or without type 2 diabetes were used to develop a population pharmacokinetic (PK) model describing semaglutide exposure. An exposure-response model describing weight change was then developed using baseline demographics, glycated haemoglobin and PK data during treatment. The ability of the exposure-response model to predict 1-year weight loss based on weight data collected at baseline and after up to 28 weeks of treatment, was assessed using three independent phase 3 trials.. Based on population PK, exposure levels over time consistently explained the weight-loss trajectories across trials and dosing regimens. The exposure-response model had high precision and limited bias for predicting body weight loss at 1 year in independent datasets, with increased precision when data from later time points were included in the prediction.. An exposure-response model has been established that quantitatively describes the relationship between systemic semaglutide exposure and weight loss and predicts weight-loss trajectories for people with overweight or obesity who are receiving semaglutide doses up to 2.4 mg once weekly. Topics: Diabetes Mellitus, Type 2; Glucagon-Like Peptide 1; Glucagon-Like Peptides; Humans; Hypoglycemic Agents; Obesity; Overweight; Weight Loss | 2023 |
Pregnancy glucagon-like peptide 1 predicts insulin but not glucose concentrations.
Incretin hormones glucagon-like peptide 1 (GLP-1) and gastric inhibitory peptide (GIP) cause increased insulin secretion in non-pregnant adults, but their role in pregnancy, where there are additional metabolically-active hormones from the placenta, is less clear. The aim of the present study was to assess if fasting and post-load incretin concentrations were predictive of pregnancy insulin and glucose concentrations.. Pregnant women (n = 394) with one or more risk factors for gestational diabetes were recruited at 28 weeks for a 75 g oral glucose tolerance test (OGTT). Glucose, insulin, GLP-1 and GIP were measured in the fasting state and 120 min after glucose ingestion.. Fasting plasma GLP-1 concentrations were associated with plasma insulin (standardised β' 0.393 (0.289-0.498), p = 1.3 × 10. These results suggest that the relationship between insulin and incretins is preserved in pregnancy, but that other factors, such as placental hormones or counter-regulatory hormones, may be more important determinants of glycaemia and gestational diabetes aetiology. Topics: Adult; Blood Glucose; Diabetes Mellitus, Type 2; Diabetes, Gestational; Female; Gastric Inhibitory Polypeptide; Glucagon-Like Peptide 1; Glucose; Humans; Incretins; Insulin; Placenta; Pregnancy | 2023 |
Aspiration risk with glucagon-like peptide 1 (GLP-1) agonists.
Topics: Diabetes Mellitus, Type 2; Disease Susceptibility; Glucagon-Like Peptide 1; Humans; Hypoglycemic Agents | 2023 |
Are GLP-1R agonists the long-sought-after panacea for obesity?
Glucagon-like peptide 1 (GLP-1) receptor (GLP-1R) agonists are hugely effective in the treatment of obesity. Originally developed for type 2 diabetes (T2D), these drugs cause dramatic weight loss in people with overweight or obesity, but how do they work, and are these therapeutics the long-sought-after solution to obesity? Here we explain the mechanisms of action of GLP-1R agonists in the context of weight loss and discuss their importance as therapeutics for obesity treatment. Topics: Diabetes Mellitus, Type 2; Glucagon-Like Peptide 1; Glucagon-Like Peptide-1 Receptor; Humans; Obesity; Weight Loss | 2023 |
Approach to obesity in the elderly population: a consensus report from the Diabetes, Obesity and Nutrition Working Group of SEMI (Spanish Society of Internal Medicine).
Obesity in the elderly not only impacts morbidity and mortality but their quality of life. This phenomenon has sparked extensive research and debate regarding treatment recommendations, primarly due to the lack evidence in this specific population. When addressing possible treatment recommendations for older adults with obesity, it is crucial to assess certain essential aspects such as functional status, sarcopenia, cognitive status, and others. Intentional weight loss in this population can be both effective and safe. The best weight loss plan for the elderly revolves around adopting a healthy lifestyle, which includes following a Mediterranean diet pattern and engaging in physical exercise, particularly strength training. Additionally, the use of weight loss medications, particularly glucagon-like peptide-1 receptor agonists (GLP-1 RA) and novel glucose-dependent insulinotropic polypeptide (GIP)/GLP-1 receptor agonists, can provide an additional stage of treatment. In selective candidates, bariatric surgery may also be considered. The objective of this document is to propose a comprehensive algorithm of recommendations for the management of obesity in the elderly (above the age of 65), based on scientific evidence and the expertise of members from the Diabetes, Obesity, and Nutrition Workgroup of the Spanish Society of Internal Medicine. Topics: Aged; Consensus; Diabetes Mellitus, Type 2; Glucagon-Like Peptide 1; Humans; Obesity; Quality of Life; Weight Loss | 2023 |
News in diabetology 2022.
The use of new antidiabetic drugs in clinical practice in the last two decades has completely changed the Type 2 diabetes management. Following the results of new clinical trials, international recommendations for the treatment of diabetes were regularly modified. In the field of Type 1 diabetes, new technologies have appeared, such as smart insulin pens. We can await once weekly insulins and dual GLP-1 and GIP analogues in the near future. Topics: Diabetes Mellitus, Type 2; Glucagon-Like Peptide 1; Glucagon-Like Peptide-1 Receptor; Humans; Hypoglycemic Agents; Insulin | 2023 |
Are GLP-1 agonists the answer to our obesity epidemic?
Topics: Diabetes Mellitus, Type 2; Glucagon-Like Peptide 1; Humans; Hypoglycemic Agents; Obesity | 2023 |
Targeted MicroRNA Profiling Reveals That Exendin-4 Modulates the Expression of Several MicroRNAs to Reduce Steatosis in HepG2 Cells.
Excess hepatic lipid accumulation is the hallmark of non-alcoholic fatty liver disease (NAFLD), for which no medication is currently approved. However, glucagon-like peptide-1 receptor agonists (GLP-1RAs), already approved for treating type 2 diabetes, have lately emerged as possible treatments. Herein we aim to investigate how the GLP-1RA exendin-4 (Ex-4) affects the microRNA (miRNAs) expression profile using an in vitro model of steatosis. Total RNA, including miRNAs, was isolated from control, steatotic, and Ex-4-treated steatotic cells and used for probing a panel of 799 highly curated miRNAs using NanoString technology. Enrichment pathway analysis was used to find the signaling pathways and cellular functions associated with the differentially expressed miRNAs. Our data shows that Ex-4 reversed the expression of a set of miRNAs. Functional enrichment analysis highlighted many relevant signaling pathways and cellular functions enriched in the differentially expressed miRNAs, including hepatic fibrosis, insulin receptor, PPAR, Wnt/β-Catenin, VEGF, and mTOR receptor signaling pathways, fibrosis of the liver, cirrhosis of the liver, proliferation of hepatic stellate cells, diabetes mellitus, glucose metabolism disorder and proliferation of liver cells. Our findings suggest that miRNAs may play essential roles in the processes driving steatosis reduction in response to GLP-1R agonists, which warrants further functional investigation. Topics: Diabetes Mellitus, Type 2; Exenatide; Glucagon-Like Peptide 1; Glucagon-Like Peptide-1 Receptor; Hep G2 Cells; Humans; Liver Cirrhosis; MicroRNAs; Non-alcoholic Fatty Liver Disease | 2023 |
Microbial-host-isozyme analyses reveal microbial DPP4 as a potential antidiabetic target.
A mechanistic understanding of how microbial proteins affect the host could yield deeper insights into gut microbiota-host cross-talk. We developed an enzyme activity-screening platform to investigate how gut microbiota-derived enzymes might influence host physiology. We discovered that dipeptidyl peptidase 4 (DPP4) is expressed by specific bacterial taxa of the microbiota. Microbial DPP4 was able to decrease the active glucagon like peptide-1 (GLP-1) and disrupt glucose metabolism in mice with a leaky gut. Furthermore, the current drugs targeting human DPP4, including sitagliptin, had little effect on microbial DPP4. Using high-throughput screening, we identified daurisoline-d4 (Dau-d4) as a selective microbial DPP4 inhibitor that improves glucose tolerance in diabetic mice. Topics: Animals; Bacteroides; Diabetes Mellitus, Type 2; Dipeptidyl Peptidase 4; Dipeptidyl-Peptidase IV Inhibitors; Feces; Gastrointestinal Microbiome; Glucagon-Like Peptide 1; Glucose; Host Microbial Interactions; Humans; Hypoglycemic Agents; Isoenzymes; Mice; Sitagliptin Phosphate | 2023 |
Implications of Ozempic and Other Semaglutide Medications for Facial Plastic Surgeons.
Obesity is a growing global health concern, leading to various health issues, including diabetes. Semaglutide-based medications, such as Ozempic, Wegovy, and Rybelsus, have emerged as potential treatments. These medications, belonging to the glucagon-like peptide-1 (GLP-1) receptor agonist class, mimic the action of GLP-1, regulating appetite and promoting weight loss. Clinical trials have shown their effectiveness in reducing body weight and improving metabolic parameters. Ozempic, though Food and Drug Administration-approved for diabetes, is also used off-label for weight loss alone. Rapid weight and fat loss with Ozempic can lead to the characteristic "Ozempic face," where facial volume and fat are depleted, resulting in wrinkles and sagging skin. Providers prescribing Ozempic seldom counsel patients about the potential impact on the face. As a result, the plastic surgery community faces a challenge in managing facial changes associated with rapid weight loss. Dermal fillers, skin tightening techniques, and surgical interventions are useful for both restoration of facial volume and to manage excess skin. Discontinuation of Ozempic should be considered prior to general anesthesia due to gastrointestinal side effects including delayed gastric emptying. As the popularity of Ozempic grows, facial plastic surgeons must be aware of both the impact on facial appearance and perioperative considerations. Topics: Diabetes Mellitus, Type 2; Glucagon-Like Peptide 1; Humans; Hypoglycemic Agents; Surgeons; United States; Weight Loss | 2023 |
Neprilysin deficiency reduces hepatic gluconeogenesis in high fat-fed mice.
Topics: Animals; Blood Glucose; Diabetes Mellitus, Type 2; Glucagon-Like Peptide 1; Gluconeogenesis; Glucose; Insulin; Liver; Liver Glycogen; Mice; Neprilysin; Obesity | 2023 |
Development of a novel Fc fusion protein dual glucagon-like peptide-1 and gastric inhibitory polypeptide receptor agonists.
To develop and investigate an imbalanced dual gastric inhibitory polypeptide receptor (GIPR)/glucagon-like peptide-1 receptor (GLP-1 R) agonist with Fc fusion protein structure.. We designed and constructed an Fc fusion protein that is a dual agonist (HEC-CG115) with an empirically optimized potency ratio for GLP-1R and GIPR. The long-term effects of HEC-CG115 on body weight and glycaemic control were evaluated in diet-induced obese mice and diabetic db/db mice. Repeat dose toxicity assays were performed to investigate the safety profile of HEC-CG115 in Sprague-Dawley rats.. HEC-CG115 displayed high potency for GIPR and relatively low potency for GLP-1R, and we labelled it 'imbalanced'. In animal models, HEC-CG115 (3 nmol/kg) led to more weight loss than semaglutide at a higher dose (10 nmol/kg) in diet-induced obese model mice. HEC-CG115 (one dose every 3 days) reduced fasting blood glucose and glycated haemoglobin levels similar to those after semaglutide (once daily) at the same dose. In a 4-week subcutaneous toxicity study conducted to assess the biosafety of HEC-CG115, the no observed adverse effect level was determined to be 3 mg/kg.. HEC-CG115 is a novel Fc fusion protein with imbalanced dual agonism that shows superior weight loss, glycaemic control and metabolic improvement in animal models, and has an optimal safety profile according to a repeat-dose toxicity study. Therefore, the use of HEC-CG115 appears to be safe and effective for the treatment of obesity and type 2 diabetes. Topics: Animals; Diabetes Mellitus, Type 2; Gastric Inhibitory Polypeptide; Glucagon-Like Peptide 1; Glucagon-Like Peptide-1 Receptor; Mice; Rats; Rats, Sprague-Dawley; Receptors, G-Protein-Coupled; Weight Loss | 2023 |
Effects of GLP-1 receptor agonists on mitochondrial function, inflammatory markers and leukocyte-endothelium interactions in type 2 diabetes.
Type 2 diabetes (T2D) is linked to metabolic, mitochondrial and inflammatory alterations, atherosclerosis development and cardiovascular diseases (CVDs). The aim was to investigate the potential therapeutic benefits of GLP-1 receptor agonists (GLP-1 RA) on oxidative stress, mitochondrial respiration, leukocyte-endothelial interactions, inflammation and carotid intima-media thickness (CIMT) in T2D patients.. Type 2 diabetic patients (255) and control subjects (175) were recruited, paired by age and sex, and separated into two groups: without GLP-1 RA treatment (196) and treated with GLP-1 RA (59). Peripheral blood polymorphonuclear leukocytes (PMNs) were isolated to measure reactive oxygen species (ROS) production by flow cytometry and oxygen consumption with a Clark electrode. PMNs were also used to assess leukocyte-endothelial interactions. Circulating levels of adhesion molecules and inflammatory markers were quantified by Luminex's technology, and CIMT was measured as surrogate marker of atherosclerosis.. Treatment with GLP-1 RA reduced ROS production and recovered mitochondrial membrane potential, oxygen consumption and MPO levels. The velocity of leukocytes rolling over endothelial cells increased in PMNs from GLP-1 RA-treated patients, whereas rolling and adhesion were diminished. ICAM-1, VCAM-1, IL-6, TNFα and IL-12 protein levels also decreased in the GLP-1 RA-treated group, while IL-10 increased. CIMT was lower in GLP-1 RA-treated T2D patients than in T2D patients without GLP-1 RA treatment.. GLP-1 RA treatment improves the redox state and mitochondrial respiration, and reduces leukocyte-endothelial interactions, inflammation and CIMT in T2D patients, thereby potentially diminishing the risk of atherosclerosis and CVDs. Topics: Atherosclerosis; Cardiovascular Diseases; Carotid Intima-Media Thickness; Diabetes Mellitus, Type 2; Endothelial Cells; Endothelium; Glucagon-Like Peptide 1; Glucagon-Like Peptide-1 Receptor; Humans; Inflammation; Leukocytes; Reactive Oxygen Species | 2023 |
6-Azaspiro[2.5]octanes as small molecule agonists of the human glucagon-like peptide-1 receptor.
Activation of the glucagon-like peptide-1 (GLP-1) receptor stimulates insulin release, lowers plasma glucose levels, delays gastric emptying, increases satiety, suppresses food intake, and affords weight loss in humans. These beneficial attributes have made peptide-based agonists valuable tools for the treatment of type 2 diabetes mellitus and obesity. However, efficient, and consistent delivery of peptide agents generally requires subcutaneous injection, which can reduce patient utilization. Traditional orally absorbed small molecules for this target may offer improved patient compliance as well as the opportunity for co-formulation with other oral therapeutics. Herein, we describe an SAR investigation leading to small-molecule GLP-1 receptor agonists that represent a series that parallels the recently reported clinical candidate danuglipron. In the event, identification of a benzyloxypyrimidine lead, using a sensitized high-throughput GLP-1 agonist assay, was followed by optimization of the SAR using substituent modifications analogous to those discovered in the danuglipron series. A new series of 6-azaspiro[2.5]octane molecules was optimized into potent GLP-1 agonists. Information gleaned from cryogenic electron microscope structures was used to rationalize the SAR of the optimized compounds. Topics: Diabetes Mellitus, Type 2; Glucagon-Like Peptide 1; Glucagon-Like Peptide-1 Receptor; High-Throughput Screening Assays; Humans; Hypoglycemic Agents; Octanes; Spiro Compounds | 2023 |
The alleviating effect and mechanism of GLP-1 on ulcerative colitis.
Topics: Animals; Body Weight; Colitis, Ulcerative; Diabetes Mellitus, Type 2; Glucagon-Like Peptide 1; Mice; Quality of Life | 2023 |
SIRT1 Controls Enteroendocrine Progenitor Cell Proliferation in High-Fat Diet-Fed Mice.
We aimed to investigate how sirtuin 1 (SIRT1), a conserved mammalian Nicotinamide adenine dinucleotide. We used mice with specific Sirt1 disruption in the intestinal epithelium (VilKO, villin-Cre. In HFD-fed VilKO and NgnKO mice, an increase in EECs (42.3% and 37.2%), GLP-1- or GLP-2-producing L cells (93.0% and 61.4%), and GLP-1 (85.7% and 109.6%) was observed after glucose loading, explaining the improved metabolic phenotype of HFD-VilKO mice. These increases were associated with up-regulated expression of neurogenin 3 (EEPC marker) in crypts of HFD-VilKO and HFD-NgnKO mice, respectively. Conversely, Sir2d or 24-hour fasted mice showed a decrease in EECs (21.6%), L cells (41.6%), and proliferative progenitor cells. SIRT1 overexpression- or knockdown-mediated change in the progenitor cell proliferation was associated with Wnt/β-catenin activity changes. Notably, Wnt/β-catenin inhibitor completely suppressed EEC and L-cell increases in HFD-VilKO mice or organoids from HFD-VilKO and HFD-NgnKO mice.. Intestinal SIRT1 in EECs modulates the EEPC cycle by regulating β-catenin activity and can control the number of EECs in HFD-fed mice, which is a previously unknown role. Topics: Animals; beta Catenin; Cell Proliferation; Diabetes Mellitus, Type 2; Diet, High-Fat; Glucagon-Like Peptide 1; Glucose; Mammals; Mice; Neoplasms; Sirtuin 1 | 2023 |
Incretin hormone responses to carbohydrate and protein/fat are preserved in adults with sulfonylurea-treated KCNJ11 neonatal diabetes.
The incretin hormones glucagon-like peptide-1 (GLP-1) and glucose-dependent insulinotropic polypeptide (GIP), are thought to be the main drivers of insulin secretion in individuals with sulfonylurea (SU)-treated KCNJ11 permanent neonatal diabetes. The aim of this study was to assess for the first time the incretin hormone response to carbohydrate and protein/fat in adults with sulfonylurea-treated KCNJ11 permanent neonatal diabetes compared with that of controls without diabetes. Participants were given a breakfast high in carbohydrate and an isocaloric breakfast high in protein/fat on two different mornings. Incremental area under the curve and total area under the curve (0-240 minutes) for total GLP-1 and GIP were compared between groups, using non-parametric statistical methods. Post-meal GLP-1 and GIP secretion were similar in cases and controls, suggesting this process is adenosine triphosphate-sensitive potassium channel-independent. Future research will investigate whether treatments targeting the incretin pathway are effective in individuals with KCNJ11 permanent neonatal diabetes who do not have good glycemic control on sulfonylurea alone. Topics: Adult; Blood Glucose; Diabetes Mellitus; Diabetes Mellitus, Type 2; Gastric Inhibitory Polypeptide; Glucagon; Glucagon-Like Peptide 1; Humans; Incretins; Infant, Newborn; Insulin | 2023 |
Cardiovascular efficacy and safety of antidiabetic agents: A network meta-analysis of randomized controlled trials.
An important characteristic of glucose-lowering therapies (GLTs) is their ability to prevent cardiovascular complications. We aimed to investigate the cardiorenal efficacy and general safety of GLTs.. Multicentre, randomized, clinical trials that included over 100 participants comparing antidiabetic agents with a placebo or a different antidiabetic agent and reporting major adverse cardiovascular events (MACEs), or primarily reporting heart failure, were searched in the PubMed, Embase and Cochrane databases. Data were extracted independently for random-effects network meta-analyses to calculate the hazard ratio estimates.. Forty-three trials that compared nine types of GLTs were included in the present analysis. The risk of three-point MACE was reduced in the presence of glucagon-like peptide-1 receptor agonists (GLP-1 RAs), sodium-glucose cotransporter-2 inhibitors (SGLT-2is) and thiazolidinedione therapy compared with the placebo, dipeptidyl peptidase-4 inhibitors, or insulin therapy. GLP-1 RAs were favourable for cardiovascular and renal outcomes. SGLT-2is reduced renal outcomes by ~40%, which was superior to other GLTs. Thiazolidinedione therapy increased the risks of hospitalization for heart failure and had no benefits on mortality. Adverse events leading to drug discontinuation were higher with GLP-1 RAs and thiazolidinediones than placebo.. GLP-1 RAs, SGLT-2is and thiazolidinediones reduced three-point MACE compared with other GLTs. Each drug class had unique advantages and disadvantages. Topics: Cardiovascular Diseases; Diabetes Mellitus, Type 2; Dipeptidyl-Peptidase IV Inhibitors; Glucagon-Like Peptide 1; Glucagon-Like Peptide-1 Receptor; Glucose; Heart Failure; Humans; Hypoglycemic Agents; Network Meta-Analysis; Randomized Controlled Trials as Topic; Sodium-Glucose Transporter 2 Inhibitors; Thiazolidinediones | 2023 |
GLP-1 receptor agonists modulate blood glucose levels in T2DM by affecting Faecalibacterium prausnitzii abundance in the intestine.
Glucagon-like peptide 1 (GLP-1) receptor agonists are a class of medications used to treat type 2 diabetes, including metformin, which is considered first-line therapy for type 2 diabetes. In recent years, GLP-1 receptor agonists (GLP-1 RAs) have been found to alter the composition and structure of gut flora and also promote the production of gut probiotics. However, there have been few clinical studies regarding the effects of GLP-1 RAs on gut flora. In this study, we investigated changes in the abundance of Lactobacillus delbrueckii (L delbrueckii) and Faecalibacterium prausnitzii (F prausnitzii) 1 week after administration of a GLP-1 RA in the clinical treatment of type 2 diabetes. The association with glycemic and body mass index (BMI) correlations was also explored.. Twelve newly diagnosed patients with type 2 diabetes were examined for changes in the abundance of L delbrueckii and F prausnitzii by Fluorescence in Situ Hybridization 1 week after administration of GLP-1 RAs. Subjects BMI was measured and fasting glucose changes were detected using the glucose oxidase method, and Spearman correlation analysis was performed to explore their relevance.. There was no significant change in the abundance of L delbrueckii in the intestine (P = .695) and no significant correlation with BMI and fasting glucose levels (R = 0.134, P = .534) after the use of GLP-1 RA (R = -0.098, P = .647); F prausnitzii on the other hand had a significantly higher abundance (P = .002) and a significant negative correlation with fasting glucose level (R = -0.689, P < .001), but no significant correlation with BMI (R = -0.056, P = .796).. F prausnitzii may be one of the pathways through which glucose is regulated in the treatment of type 2 diabetes by GLP-1 RAs. Topics: Blood Glucose; Diabetes Mellitus, Type 2; Faecalibacterium prausnitzii; Glucagon-Like Peptide 1; Glucagon-Like Peptide-1 Receptor; Glucose; Humans; In Situ Hybridization, Fluorescence; Intestines | 2023 |
Denosumab Improves Glycaemic Parameters in Postmenopausal Osteoporosis Patients with Combined Type 2 Diabetes Mellitus.
This study aimed to determine whether RANKL inhibitors in postmenopausal osteoporosis patients with combined type 2 diabetes mellitus (T2DM) could improve their glucose metabolism index. First of all, 84 patients affected with postmenopausal osteoporosis with combined T2DM attending the Department of Endocrinology at the Third Hospital of Hebei Medical University were selected and randomized into two groups of 42 patients each. One group was given Denosumab 60 mg once every six months (denosumab group, D.G.), and the other group was given 2 mg ibandronate once every three months (ibandronate group, I.G.). Blood glucose parameters were compared before and after treatment in both groups and serum active GLP-1 levels and DPP-4 levels were also assessed. After treatment, there was no significant difference in fasting glucose between the two groups, but there was a significant decrease in fasting glucose in the Denosumab Group (D.G.) compared to before treatment. There was a significant difference in 2-hour postprandial glucose (2hPG) between the two groups after treatment, with the D.G. being lower than the ibandronate group (I.G.). Glycosylated haemoglobin (HbA1c) was lower in the D.G. than in the I.G. after treatment, but the difference between them was insignificant. In the D.G., serum active GLP-1 levels increased after treatment, and serum DPP-4 levels decreased. Serum GLP-1 and DPP-4 levels in the I.G. did not change compared with those before treatment. In conclusion, In the clinical management of postmenopausal osteoporosis patients with combined T2DM, the choice of RANKL inhibitors as anti-osteoporosis therapy may benefit their glycaemic parameters by elevating serum active GLP-1 levels and decreasing serum DPP-4 levels. Topics: Denosumab; Diabetes Mellitus, Type 2; Female; Glucagon-Like Peptide 1; Glucose; Humans; Ibandronic Acid; Osteoporosis, Postmenopausal; Transcription Factors | 2023 |
Regulation of Human Sortilin Alternative Splicing by Glucagon-like Peptide-1 (GLP1) in Adipocytes.
Type 2 diabetes mellitus is a chronic metabolic disease with no cure. Adipose tissue is a major site of systemic insulin resistance. Sortilin is a central component of the glucose transporter -Glut4 storage vesicles (GSV) which translocate to the plasma membrane to uptake glucose from circulation. Here, using human adipocytes we demonstrate the presence of the alternatively spliced, truncated sortilin variant (Sort_T) whose expression is significantly increased in diabetic adipose tissue. Artificial-intelligence-based modeling, molecular dynamics, intrinsically disordered region analysis, and co-immunoprecipitation demonstrated association of Sort_T with Glut4 and decreased glucose uptake in adipocytes. The results show that glucagon-like peptide-1 (GLP1) hormone decreases Sort_T. We deciphered the molecular mechanism underlying GLP1 regulation of alternative splicing of human sortilin. Using splicing minigenes and RNA-immunoprecipitation assays, the results show that GLP1 regulates Sort_T alternative splicing via the splice factor, TRA2B. We demonstrate that targeted antisense oligonucleotide morpholinos reduces Sort_T levels and improves glucose uptake in diabetic adipocytes. Thus, we demonstrate that GLP1 regulates alternative splicing of sortilin in human diabetic adipocytes. Topics: Adipocytes; Alternative Splicing; Diabetes Mellitus, Type 2; Glucagon-Like Peptide 1; Glucose; Humans | 2023 |
What about glucagon-like peptide-1 receptor agonist for all? Recent data and perspectives.
Topics: Diabetes Mellitus, Type 2; Glucagon-Like Peptide 1; Glucagon-Like Peptide-1 Receptor; Humans; Hypoglycemic Agents | 2023 |
Data from network meta-analyses can inform clinical practice guidelines and decision-making in diabetes management: perspectives of the taskforce of the guideline workshop.
In recent years, several novel agents have become available to treat individuals with type 2 diabetes (T2D), such as sodium-glucose cotransporter-2 inhibitors (SGLT-2i), tirzepatide, which is a dual glucose-dependent insulinotropic polypeptide receptor agonist (GIP RA)/glucagon-like peptide-1 receptor agonist (GLP-1 RA), and finerenone, a non-steroidal mineralocorticoid receptor antagonist (MRA) that confers significant renal and cardiovascular benefits in individuals with (CKD). New medications have the potential to improve the lives of individuals with diabetes. However, clinicians are challenged to understand the benefits and potential risks associated with these new and emerging treatment options. In this article, we discuss how use of network meta-analyses (NMA) can fill this need. Topics: Diabetes Mellitus, Type 2; Glucagon-Like Peptide 1; Glucagon-Like Peptide-1 Receptor; Humans; Hypoglycemic Agents; Kidney; Network Meta-Analysis; Sodium-Glucose Transporter 2 Inhibitors | 2023 |
The novel GLP-1/GIP dual agonist DA3-CH improves rat type 2 diabetes through activating AMPK/ACC signaling pathway.
Type 2 diabetes mellitus (T2DM) accounts for more than 95% of all diabetes. DA3-CH is a novel dual receptor agonist of glucagon like peptide-1 (GLP-1) and glucose dependent insulin stimulating polypeptide (GIP). The regulatory role of DA3-CH in T2DM has not been reported.. T2DM rat model was established successfully with high sugar and fat feed and streptomycin (STZ) induction. The mRNA and protein expression were measured with RT-PCR and western blotting. The apoptosis level in the pancreatic tissue was evaluated with Tunel staining. Blood glucose, fat, and oxidative stress indicators were measured.. DA3-CH greatly improved T2DM symptoms by reducing blood glucose, blood fat, pancreatic tissue injury, apoptosis, and oxidative stress condition. The inactivation of Adenylate activated protein kinase (AMPK)/acetyl CoA carboxylase (ACC) signaling pathway in T2DM rats was promoted by DA3-CH. The influence of DA3-CH was significantly reversed by Com-C, the inhibitor of AMPK/ACC signaling pathway.. DA3-CH might improve T2DM through targeting AMPK/ACC signaling pathway. This study might provide a novel therapeutic strategy for the prevention and treatment of T2DM through targeting DA3-CH and AMPK/ACC signaling pathway. Topics: Acetyl-CoA Carboxylase; AMP-Activated Protein Kinases; Animals; Blood Glucose; Diabetes Mellitus, Type 2; Glucagon-Like Peptide 1; Rats; Signal Transduction | 2023 |
Designing and computational analyzing of chimeric long-lasting GLP-1 receptor agonists for type 2 diabetes.
Glucagon-like peptide-1 (GLP-1) is an intestinally derived incretin that plays a vital role in engineering the biological circuit involved in treating type 2 diabetes. Exceedingly short half-life (1-2 min) of GLP-1 limits its therapeutic applicability, and the implication of its new variants is under question. Since albumin-binding DARPin as a mimetic molecule has been reported to increase the serum half-life of therapeutic compounds, the interaction of new variants of GLP-1 in fusion with DARPin needs to be examined against the GLP-1 receptor. This study was aimed to design stable and functional fusion proteins consisting of new protease-resistant GLP-1 mutants (mGLP1) genetically fused to DARPin as a critical step toward developing long-acting GLP-1 receptor agonists. The stability and solubility of the engineered fusion proteins were analyzed, and their secondary and tertiary structures were predicted and satisfactorily validated. Molecular dynamics simulation studies revealed that the predicted structures of engineered fusion proteins remained stable throughout the simulation. The relative binding affinity of the engineered fusion proteins' complex with human serum albumin and the GLP-1 receptor individually was assessed using molecular docking analyses. It revealed a higher affinity compared to the interaction of the individual GLP-1 and HSA-binding DARPin with the GLP-1 receptor and human serum albumin, respectively. The present study suggests that engineered fusion proteins can be used as a potential molecule in the treatment of type 2 diabetes, and this study provides insight into further experimental use of mimetic complexes as alternative molecules to be evaluated as new bio-breaks in the engineering of biological circuits in the treatment of type 2 diabetes. Topics: Designed Ankyrin Repeat Proteins; Diabetes Mellitus, Type 2; Glucagon-Like Peptide 1; Glucagon-Like Peptide-1 Receptor; Humans; Hypoglycemic Agents; Molecular Docking Simulation; Serum Albumin, Human | 2023 |
Effect of combined administration of Acyl-CoA: Cholesterol acyltransferase 1 inhibitor and glucagon-like peptide 1 receptor agonist on a rodent model of diet-induced obesity.
A glucagon-like peptide 1 receptor agonist (GLP-1 RA) semaglutide was approved for the treatment of obesity by the Food and Drug Administration. However, it can cause gastrointestinal events at high doses, limiting its broader use. Combining drugs with multiple mechanisms of action could enhance the weight-reducing effects while minimizing side effects. To this end, we investigated the combined effects of semaglutide and avasimibe, an acyl-CoA:cholesterol acyltransferase 1 (ACAT1) inhibitor, on weight reduction in diet-induced obesity mice. Two cohorts of mice were used: In cohort 1, mice were fed a high-fat (HF) diet for 12 weeks and then randomly assigned to the vehicle, avasimibe [10 mg/kg body weight (BW)], semaglutide (0.4 mg/kg BW), or combination groups. The drugs were administered via subcutaneous (sc) injections on a daily basis. In cohort 2, mice were fed an HF diet for 8 weeks and randomly assigned to the same four groups, but avasimibe was administered at a dose of 20 mg/kg BW, and the drugs were administered every 3 days. In cohort 1, semaglutide initially reduced food intake initially, but this effect was diminished with prolonged administration. Avasimibe, on the other hand, did not affect food intake but prevented weight gain to a lesser extent than semaglutide. Importantly, the combination treatment resulted in the greatest percentage of body weight reduction, along with lower plasma glucose and leptin levels compared to the semaglutide single-treatment group. Cohort 2 confirmed that the superior weight loss in the combination group compared to the other three groups was largely due to a significant reduction in fat mass. Histological analysis of inguinal adipose tissue showed smaller adipocyte size across all treatment groups compared to the vehicle group, with no significant differences among the treatment groups. Collectively, these findings suggest combining semaglutide and avasimibe could be an effective approach to weight management. Topics: Acyl Coenzyme A; Acyltransferases; Animals; Diabetes Mellitus, Type 2; Diet; Glucagon-Like Peptide 1; Glucagon-Like Peptide-1 Receptor; Humans; Hypoglycemic Agents; Mice; Obesity; Rodentia; Sterol O-Acyltransferase; Weight Loss | 2023 |
GLP-1 and dual GIP/GLP-1 receptor agonists in overweight/obese patients for atherosclerotic cardiovascular disease prevention: Where are we now?
Topics: Cardiovascular Diseases; Diabetes Mellitus, Type 2; Gastric Inhibitory Polypeptide; Glucagon-Like Peptide 1; Glucagon-Like Peptide-1 Receptor; Humans; Obesity; Overweight | 2023 |
Once-weekly glucagon-like peptide-1 receptor agonists vs dipeptidyl peptidase-4 inhibitors: cardiovascular effects in people with diabetes and cardiovascular disease.
Glucagon-like peptide-1 receptor agonists (GLP-1 RAs), which have proven cardiovascular benefits, are recommended in people with type 2 diabetes (T2D) and atherosclerotic cardiovascular disease (ASCVD). However, there is limited real-world evidence comparing the effects of once-weekly (OW) GLP-1 RAs and dipeptidyl peptidase-4 inhibitors (DPP-4is). This observational cohort study (1/1/2017-9/30/2021) used data from the Optum Clinformatics. Time to occurrence of ischemic stroke, myocardial infarction (MI), or their composite and ASCVD-related and all-cause HCRU and medical costs were investigated. Baseline characteristics were balanced using inverse probability of treatment weighting. Survival analyses were conducted to compare risks during exposure.. OW GLP-1 RA users (weighted N = 25,287) had 26%, 22%, and 24% lower risk of ischemic stroke, MI, and their composite, respectively, compared with DPP-4i users (weighted N = 39,684; all P < 0.01). Compared with DPP-4i users, OW GLP-1 RA users had 25% and 26% lower ASCVD-related and all-cause hospitalization costs, 19% and 23% lower ASCVD-related and all-cause medical costs, 23% and 27% fewer ASCVD-related and all-cause hospitalizations, 13% and 8% fewer ASCVD-related and all-cause outpatient visits, and 8% fewer all-cause ER visits (all P < 0.01).. In adults with T2D and ASCVD, OW GLP-1 RAs are associated with reduced stroke and MI risks and ASCVD-related and all-cause HCRU and costs vs DPP-4is. Topics: Adult; Cardiovascular Diseases; Diabetes Mellitus, Type 2; Dipeptidyl-Peptidase IV Inhibitors; Dipeptidyl-Peptidases and Tripeptidyl-Peptidases; Glucagon-Like Peptide 1; Glucagon-Like Peptide-1 Receptor; Humans; Hypoglycemic Agents; Ischemic Stroke; Myocardial Infarction; Risk Factors | 2023 |
Use of a biomimetic hydrogel depot technology for sustained delivery of GLP-1 receptor agonists reduces burden of diabetes management.
Glucagon-like peptide-1 (GLP-1) is an incretin hormone and neurotransmitter secreted from intestinal L cells in response to nutrients to stimulate insulin and block glucagon secretion in a glucose-dependent manner. Long-acting GLP-1 receptor agonists (GLP-1 RAs) have become central to treating type 2 diabetes (T2D); however, these therapies are burdensome, as they must be taken daily or weekly. Technological innovations that enable less frequent administrations would reduce patient burden and increase patient compliance. Herein, we leverage an injectable hydrogel depot technology to develop a GLP-1 RA drug product capable of months-long GLP-1 RA delivery. Using a rat model of T2D, we confirm that one injection of hydrogel-based therapy sustains exposure of GLP-1 RA over 42 days, corresponding to a once-every-4-months therapy in humans. Hydrogel therapy maintains management of blood glucose and weight comparable to daily injections of a leading GLP-1 RA drug. This long-acting GLP-1 RA treatment is a promising therapy for more effective T2D management. Topics: Animals; Biomimetics; Diabetes Mellitus, Type 2; Glucagon-Like Peptide 1; Glucagon-Like Peptide-1 Receptor; Humans; Hydrogels; Hypoglycemic Agents; Rats | 2023 |
Semaglutide and Tirzepatide reduce alcohol consumption in individuals with obesity.
Alcohol Use Disorder (AUD) contributes significantly to global mortality. GLP-1 (Glucagon-like peptide-1) and GLP-1/GIP (Glucose-dependent Insulinotropic Polypeptide) agonists, FDA-approved for managing type 2 diabetes and obesity, where the former has shown to effectively reduce the consumption of alcohol in animal models but no reports exist on the latter. In this report, we conducted two studies. In the first study, we conducted an analysis of abundant social media texts. Specifically, a machine-learning based attribution mapping of ~ 68,250 posts related to GLP-1 or GLP-1/GIP agonists on the Reddit platform. Secondly, we recruited participants (n = 153; current alcohol drinkers; BMI ≥ 30) who self-reported either taking Semaglutide (GLP-1 agonist), Tirzepatide (the GLP-1/GIP combination) for ≥ 30 days or, as a control group; no medication to manage diabetes or weight loss for a within and between subject remote study. In the social media study, we report 8 major themes including effects of medications (30%); diabetes (21%); and Weight loss and obesity (19%). Among the alcohol-related posts (n = 1580), 71% were identified as craving reduction, decreased desire to drink, and other negative effects. In the remote study, we observe a significantly lower self-reported intake of alcohol, drinks per drinking episode, binge drinking odds, Alcohol Use Disorders Identification Test (AUDIT) scores, and stimulating, and sedative effects in the Semaglutide or Tirzepatide group when compared to prior to starting medication timepoint (within-subjects) and the control group (between-subjects). In summary, we provide initial real-world evidence of reduced alcohol consumption in people with obesity taking Semaglutide or Tirzepatide medications, suggesting potential efficacy for treatment in AUD comorbid with obesity. Topics: Alcohol Drinking; Alcoholism; Animals; Diabetes Mellitus, Type 2; Ethanol; Gastric Inhibitory Polypeptide; Glucagon-Like Peptide 1; Glucagon-Like Peptide-1 Receptor; Humans; Hypoglycemic Agents; Obesity; Weight Loss | 2023 |
Increased Insulin Secretion and Glucose Effectiveness in Obese Patients with Type 2 Diabetes following Bariatric Surgery.
To determine the contribution of these regulators on glucose tolerance after bariatric surgery, an oral glucose tolerance test (OGTT) was performed before and 2 months after surgery in 9 RYGB and 7 SG subjects. Eight healthy subjects served as metabolic controls. Plasma glucose, insulin, C-peptide, GLP-1, and GIP were measured during each OGTT. Insulin sensitivity and secretion, glucose effectiveness, and glucose rate of appearance were determined via oral minimal models.. RYGB and SG resulted in similar weight reductions (13%, RYGB (. These results demonstrate that the early improvement in glucose tolerance in obese T2D after RYGB and SG surgeries is attributable mainly to increased insulin secretion and glucose effectiveness, while insulin sensitivity seems to play only a minor role. This trial is registered with NCT02713555. Topics: Bariatric Surgery; Blood Glucose; Diabetes Mellitus, Type 2; Gastrectomy; Gastric Bypass; Glucagon-Like Peptide 1; Glucose; Humans; Insulin; Insulin Resistance; Insulin Secretion; Obesity | 2023 |
Mendelian randomization analyses suggest a causal role for circulating GIP and IL-1RA levels in homeostatic model assessment-derived measures of β-cell function and insulin sensitivity in Africans without type 2 diabetes.
In vitro and in vivo studies have shown that certain cytokines and hormones may play a role in the development and progression of type 2 diabetes (T2D). However, studies on their role in T2D in humans are scarce. We evaluated associations between 11 circulating cytokines and hormones with T2D among a population of sub-Saharan Africans and tested for causal relationships using Mendelian randomization (MR) analyses.. We used logistic regression analysis adjusted for age, sex, body mass index, and recruitment country to regress levels of 11 cytokines and hormones (adipsin, leptin, visfatin, PAI-1, GIP, GLP-1, ghrelin, resistin, IL-6, IL-10, IL-1RA) on T2D among Ghanaians, Nigerians, and Kenyans from the Africa America Diabetes Mellitus study including 2276 individuals with T2D and 2790 non-T2D individuals. Similar linear regression models were fitted with homeostatic modelling assessments of insulin sensitivity (HOMA-S) and β-cell function (HOMA-B) as dependent variables among non-T2D individuals (n = 2790). We used 35 genetic variants previously associated with at least one of these 11 cytokines and hormones among non-T2D individuals as instrumental variables in univariable and multivariable MR analyses. Statistical significance was set at 0.0045 (0.05/11 cytokines and hormones).. Circulating GIP and IL-1RA levels were associated with T2D. Nine of the 11 cytokines and hormones (exceptions GLP-1 and IL-6) were associated with HOMA-S, HOMA-B, or both among non-T2D individuals. Two-stage least squares MR analysis provided evidence for a causal effect of GIP and IL-RA on HOMA-S and HOMA-B in multivariable analyses (GIP ~ HOMA-S β = - 0.67, P-value = 1.88 × 10. The findings of this comprehensive MR analysis indicate that circulating GIP and IL-1RA levels are causal for reduced insulin sensitivity and increased β-cell function. GIP's effect being independent of BMI suggests that circulating levels of GIP could be a promising early biomarker for T2D risk. Our MR analyses do not provide conclusive evidence for a causal role of other circulating cytokines in T2D among sub-Saharan Africans. Topics: African People; Blood Glucose; Complement Factor D; Diabetes Mellitus, Type 2; Genome-Wide Association Study; Ghana; Glucagon-Like Peptide 1; Humans; Insulin; Insulin Resistance; Interleukin 1 Receptor Antagonist Protein; Interleukin-6; Kenya; Mendelian Randomization Analysis; Risk Factors | 2023 |
Pharmacist impact on evidence-based prescribing of diabetes medications in patients with clinical atherosclerotic cardiovascular disease.
Including pharmacists on care teams of patients with type 2 diabetes (T2D) has been shown to promote guideline-based prescribing and improve glycemic control, lowering risks of adverse cardiovascular outcomes. Evidence is lacking regarding whether including pharmacists on the care team is associated with the prescribing of GLP-1 receptor agonists (GLP-1 RA) and SGLT-2 inhibitors (SGLT-2i) recommended for use in patients with T2D and atherosclerotic cardiovascular disease (ASCVD).. To assess the association between having a pharmacist on the primary care team of patients with T2D and ASCVD and being prescribed a guideline-recommended GLP-1 RA or SGLT-2i.. A cross-sectional analysis of patients with T2D and ASCVD seen by primary care providers at an academic medical center between June 2019 and May 2020 was completed. Patients with prescriptions for GLP-1 RA or SGLT-2i with evidence of cardiovascular benefit were identified and compared between those with pharmacist care vs usual care using multivariable log-binominal regression analyses.. Of 1,497 included patients, 1,283 (85.7%) were in the usual care group (mean age 68.9 years, hemoglobin A1c 7.6%) and 214 (14.3%) in the pharmacist care group (mean age 64.5 years, A1c 9.0%). Of the pharmacist care group, 50.5% were prescribed a GLP-1 RA or SGLT-2i with cardiovascular benefit vs 17.9% in the usual care group (. These data provide preliminary evidence that integrating pharmacists into patient care teams is associated with increased prescribing of guideline-recommended treatment with GLP-1 RA and SGLT-2i in patients with T2D and ASCVD, yet there is room for improvement in prescribing these agents to patients with T2D and ASCVD. Topics: Aged; Atherosclerosis; Cardiovascular Diseases; Cross-Sectional Studies; Diabetes Mellitus, Type 2; Glucagon-Like Peptide 1; Glucagon-Like Peptide-1 Receptor; Glycated Hemoglobin; Humans; Hypoglycemic Agents; Middle Aged; Pharmacists; Sodium-Glucose Transporter 2 Inhibitors | 2023 |
Glucagon-like peptide 1 receptor agonist use is associated with reduced risk for glaucoma.
Glucagon-like peptide-1 receptor (GLP-1R) agonists regulate blood glucose and are commonly used to treat type 2 diabetes mellitus. Recent work showed that treatment with the GLP-1R agonist NLY01 decreased retinal neuroinflammation and glial activation to rescue retinal ganglion cells in a mouse model of glaucoma. In this study, we used an insurance claims database (Clinformatics Data Mart) to examine whether GLP-1R agonist exposure impacts glaucoma risk.. A retrospective cohort of patients who initiated a new GLP-1R agonist was 1:3 age, gender, race, classes of active diabetes medications and year of index date matched to patients who initiated a different class of oral diabetic medication. Inverse probability of treatment weighting (IPTW) was used within a multivariable Cox proportional hazard regression model to test the association between GLP-1R agonist exposure and a new diagnosis of primary open-angle glaucoma, glaucoma suspect or low-tension glaucoma.. Cohorts were comprised of 1961 new users of GLP-1R agonists matched to 4371 unexposed controls. After IPTW, all variables were balanced (standard mean deviation <|0.1|) between cohorts. Ten (0.51%) new diagnoses of glaucoma were present in the GLP-1R agonist cohort compared with 58 (1.33%) in the unexposed controls. After adjustment, GLP-1R exposure conferred a reduced hazard of 0.56 (95% CI: 0.36 to 0.89, p=0.01), suggesting that GLP-1R agonists decrease the risk for glaucoma.. GLP-1R agonist use was associated with a statistically significant hazard reduction for a new diagnosis of glaucoma. Our findings support further investigations into the use of GLP-1R agonists in glaucoma prevention. Topics: Animals; Diabetes Mellitus, Type 2; Glaucoma, Open-Angle; Glucagon-Like Peptide 1; Glucagon-Like Peptide-1 Receptor; Mice; Retrospective Studies | 2023 |
Safety and Efficacy of Glucagon-like Peptide 1 Receptor Agonists in Patients With Cirrhosis.
Topics: Diabetes Mellitus, Type 2; Glucagon-Like Peptide 1; Humans; Hypoglycemic Agents; Liver Cirrhosis | 2022 |
Gut microbiota dysbiosis of type 2 diabetic mice impairs the intestinal daily rhythms of GLP-1 sensitivity.
The gut-brain-beta cell glucagon-like peptide-1 (GLP-1)-dependent axis and the clock genes both control insulin secretion. Evidence shows that a keystone of this molecular interaction could be the gut microbiota. We analyzed in mice the circadian profile of GLP-1 sensitivity on insulin secretion and the impact of the autonomic neuropathy, antibiotic treated in different diabetic mouse models and in germ-free colonized mice. We show that GLP-1sensitivity is maximal during the dark feeding period, i.e., the postprandial state. Coincidently, the ileum expression of GLP-1 receptor and peripherin is increased and tightly correlated with a subset of clock gene. Since both are markers of enteric neurons, it suggests a role in the gut-brain-beta cell GLP-1-dependent axis. We evaluated the importance of gut microbiota dysbiosis and found that the abundance of ileum bacteria, particularly Ruminococcaceae and Lachnospiraceae, oscillated diurnally, with a maximum during the dark period, along with expression patterns of a subset of clock genes. This diurnal pattern of circadian gene expression and Lachnospiraceae abundance was also observed in two separate mouse models of gut microbiota dysbiosis and of autonomic neuropathy with impaired GLP-1 sensitivity (1.high-fat diet-fed type 2 diabetic, 2.antibiotic-treated/germ-free mice). Our data show that GLP-1 sensitivity relies on specific pattern of intestinal clock gene expression and specific gut bacteria. This new statement opens opportunities to treat diabetic patient with GLP-1-based therapies by using on a possible pre/probiotic co-treatment to improve the time-dependent efficiency of these therapies. Topics: Animals; Diabetes Mellitus, Experimental; Diabetes Mellitus, Type 2; Dysbiosis; Gastrointestinal Microbiome; Glucagon-Like Peptide 1; Humans; Mice | 2022 |
TGR5 agonists for diabetes treatment: a patent review and clinical advancements (2012-present).
A cell surface bile acid receptor TGR5 is expressed in various tissues, including the liver, kidney, intestine, and adrenal glands, causing its effect in each tissue to differ. A major role for TGR5 is to maintain blood sugar levels and increase in energy expenditure. These benefits make it a potential candidate for the treatment of type 2 diabetes, obesity, and other metabolic diseases.. This paper highlights recent advances in the development of potent steroidal and non-steroidal TGR5 agonists and the peer-reviewed scientific articles that have led to understanding the structure-activity relationship for TGR5 agonists (2012-2020). The review also discusses the clinical progress made by some TGR5 agonists over the past eight years.. In preclinical studies, TGR5 has been found to play a crucial role in GLP-1 secretion and has shown promise for weight loss, anti-diabetic outcomes etc. Semi synthetic and synthetic derivatives can be considered a potential avenue for discovering novel TGR5 agonists. Currently, few TGR5 agonists have reached the clinical trial stage, and, likely, soon novel TGR5 modulator will be discovered with fewer adverse effects. In silico studies can also be performed with various heterocyclic scaffolds to discover selective and safe TGR5 agonists. Topics: Bile Acids and Salts; Diabetes Mellitus, Type 2; Glucagon-Like Peptide 1; Humans; Obesity; Patents as Topic; Receptors, G-Protein-Coupled | 2022 |
Plasma GLP-1 Response to Oral and Intraduodenal Nutrients in Health and Type 2 Diabetes-Impact on Gastric Emptying.
Both gastric emptying and the secretion of glucagon-like peptide-1 (GLP-1) are major determinants of postprandial glycemia in health and type 2 diabetes (T2D). GLP-1 secretion after a meal is dependent on the entry of nutrients into the small intestine, which, in turn, slows gastric emptying.. To define the relationship between gastric emptying and the GLP-1 response to both oral and small intestinal nutrients in subjects with and without T2D.. We evaluated: (i) the relationship between gastric emptying (breath test) and postprandial GLP-1 levels after a mashed potato meal in 73 individuals with T2D; (ii) inter-individual variations in GLP-1 response to (a) intraduodenal glucose (4 kcal/min) during euglycemia and hyperglycemia in 11 healthy and 12 T2D, subjects, (b) intraduodenal fat (2 kcal/min) in 15 T2D subjects, and (c) intraduodenal protein (3 kcal/min) in 10 healthy subjects; and (iii) the relationship between gastric emptying (breath test) of 75 g oral glucose and the GLP-1 response to intraduodenal glucose (4 kcal/min) in 21 subjects (9 healthy, 12 T2D).. The GLP-1 response to the mashed potato meal was unrelated to the gastric half-emptying time (T50). The GLP-1 responses to intraduodenal glucose, fat, and protein varied substantially between individuals, but intra-individual variation to glucose was modest. The T50 of oral glucose was related directly to the GLP-1 response to intraduodenal glucose (r = 0.65, P = 0.002).. In a given individual, gastric emptying is not a determinant of the postprandial GLP-1 response. However, the intrinsic gastric emptying rate is determined in part by the responsiveness of GLP-1 to intestinal nutrients. Topics: Blood Glucose; Diabetes Mellitus, Type 2; Gastric Emptying; Glucagon-Like Peptide 1; Glucose; Humans; Insulin; Nutrients; Postprandial Period | 2022 |
Comparison of Beinaglutide Versus Metformin for Weight Loss in Overweight and Obese Non-diabetic Patients.
We compared the efficacy and safety of beinaglutide, a glucagon-like peptide-1 (GLP-1) analogue with metformin in lowering the bodyweight of patients who were overweight/obese and non-diabetic.. Seventy-eight non-diabetic patients were randomly selected and beinaglutide or metformin was administered for 12 weeks. The primary endpoints were changes in body weight and the proportions of patients who lost≥5 and≥10% of their baseline body weights.. A total of 64 patients completed the study; patients in the beinaglutide group exhibited more bodyweight loss than those in the metformin group [(9.5±0.8%; 9.1±0.9 kg) and (5.1±0.9%; 4.5±0.8 kg), respectively, corresponding to a difference of approximately 4.5 kg (95% confidence interval, 2.2-6.9 kg;. Beinaglutide is more efficient than metformin at reducing weight and fat mass in patients who are overweight/obese and non-diabetic. Beinaglutide may be a useful therapeutic option for overweight/obesity control in the Chinese population. Topics: Body Weight; Diabetes Mellitus, Type 2; Glucagon-Like Peptide 1; Humans; Hypoglycemic Agents; Metformin; Obesity; Overweight; Peptide Fragments; Weight Loss | 2022 |
A novel integrated QSP model of in vivo human glucose regulation to support the development of a glucagon/GLP-1 dual agonist.
Glucagon-like peptide-1 (GLP-1) receptor agonists (GLP-1RAs) and dual GLP-1/glucagon receptor agonists improve glycaemic control and cause significant weight loss in patients with type 2 diabetes. Topics: Blood Glucose; Diabetes Mellitus, Type 2; Glucagon; Glucagon-Like Peptide 1; Glucagon-Like Peptide-1 Receptor; Glucose; Humans; Insulin | 2022 |
Intra-islet glucagon confers β-cell glucose competence for first-phase insulin secretion and favors GLP-1R stimulation by exogenous glucagon.
We report that intra-islet glucagon secreted from α-cells signals through β-cell glucagon and GLP-1 receptors (GcgR and GLP-1R), thereby conferring to rat islets their competence to exhibit first-phase glucose-stimulated insulin secretion (GSIS). Thus, in islets not treated with exogenous glucagon or GLP-1, first-phase GSIS is abolished by a GcgR antagonist (LY2786890) or a GLP-1R antagonist (Ex[9-39]). Mechanistically, glucose competence in response to intra-islet glucagon is conditional on β-cell cAMP signaling because it is blocked by the cAMP antagonist prodrug Rp-8-Br-cAMPS-pAB. In its role as a paracrine hormone, intra-islet glucagon binds with high affinity to the GcgR, while also exerting a "spillover" effect to bind with low affinity to the GLP-1R. This produces a right shift of the concentration-response relationship for the potentiation of GSIS by exogenous glucagon. Thus, 0.3 nM glucagon fails to potentiate GSIS, as expected if similar concentrations of intra-islet glucagon already occupy the GcgR. However, 10 to 30 nM glucagon effectively engages the β-cell GLP-1R to potentiate GSIS, an action blocked by Ex[9-39] but not LY2786890. Finally, we report that the action of intra-islet glucagon to support insulin secretion requires a step-wise increase of glucose concentration to trigger first-phase GSIS. It is not measurable when GSIS is stimulated by a gradient of increasing glucose concentrations, as occurs during an oral glucose tolerance test in vivo. Collectively, such findings are understandable if defective intra-islet glucagon action contributes to the characteristic loss of first-phase GSIS in an intravenous glucose tolerance test that is diagnostic of type 2 diabetes in the clinical setting. Topics: Animals; Diabetes Mellitus, Type 2; Glucagon; Glucagon-Like Peptide 1; Glucagon-Like Peptide-1 Receptor; Glucose; Insulin; Insulin Secretion; Islets of Langerhans; Mice; Mice, Inbred C57BL; Rats | 2022 |
Distal mutation V486M disrupts the catalytic activity of DPP4 by affecting the flap of the propeller domain.
Dipeptidyl peptidase-4 (DPP4) plays a crucial role in regulating the bioactivity of glucagon-like peptide-1 (GLP-1) that enhances insulin secretion and pancreatic β-cell proliferation, making it a therapeutic target for type 2 diabetes. Although the crystal structure of DPP4 has been determined, its structure-function mechanism is largely unknown. Here, we examined the biochemical properties of sporadic human DPP4 mutations distal from its catalytic site, among which V486M ablates DPP4 dimerization and causes loss of enzymatic activity. Unbiased molecular dynamics simulations revealed that the distal V486M mutation induces a local conformational collapse in a β-propeller loop (residues 234-260, defined as the flap) and disrupts the dimerization of DPP4. The "open/closed" conformational transitions of the flap whereby capping the active site, are involved in the enzymatic activity of DPP4. Further site-directed mutagenesis guided by theoretical predictions verified the importance of the conformational dynamics of the flap for the enzymatic activity of DPP4. Therefore, the current studies that combined theoretical modeling and experimental identification, provide important insights into the biological function of DPP4 and allow for the evaluation of directed DPP4 genetic mutations before initiating clinical applications and drug development. Topics: Diabetes Mellitus, Type 2; Dipeptidyl Peptidase 4; Glucagon-Like Peptide 1; Humans; Mutation | 2022 |
Pancreatic and gut hormone responses to mixed meal test in post-chronic pancreatitis diabetes mellitus.
More than one-third of chronic pancreatitis patients will eventually develop diabetes, recently classified as post-chronic pancreatitis diabetes mellitus (PPDM-C). This study was aimed to investigate the pancreatic and gut hormone responses to a mixed meal test in PPDM-C patients, compared with non-diabetic chronic pancreatitis (CP), and type 2 diabetes patients or healthy controls.. Sixteen patients with PPDM-C, 12 with non-diabetic CP as well as 10 with type 2 diabetes and healthy controls were recruited. All participants underwent mixed meal tests, and blood samples were collected for measurements of blood glucose, C-peptide, insulin, glucagon, pancreatic polypeptide (PP), ghrelin, peptide YY, glucagon like peptide-1 (GLP-1) and gastric inhibitory peptide (GIP). Indices of insulin sensitivity and secretion were calculated. Repeated measures analysis of variance was performed.. Participants with PPDM-C exhibited decreases in both fasting and postprandial responses of C-peptide (P < 0.001), insulin (P < 0.001), ghrelin (P < 0.001) and PYY (P = 0.006) compared to participants with type 2 diabetes and healthy controls. Patients with CP showed blunted glucagon, PP and incretin reactions, while the responses were increased in patients with PPDM-C compared to controls. The level of insulin sensitivity was higher for PPDM-C than type 2 diabetes (P < 0.01), however the indices for early/late-phase and overall insulin secretion (P < 0.01) were lower.. Patients with PPDM-C are characterized by decreased C-peptide, insulin, ghrelin and PYY responses, and similar levels of glucagon, PP, GIP and GLP-1 compared to those with type 2 diabetes. The above findings, when confirmed in a larger population, may prove helpful to establish the diagnosis of PPDM-C, and should promote study on underlying pathophysiological mechanisms. Topics: Blood Glucose; C-Peptide; Diabetes Mellitus, Type 2; Gastric Inhibitory Polypeptide; Ghrelin; Glucagon; Glucagon-Like Peptide 1; Humans; Insulin; Insulin Resistance; Pancreatitis, Chronic; Peptide YY | 2022 |
Obesity and GLP-1 RAs.
Topics: Anti-Obesity Agents; Diabetes Mellitus, Type 2; Glucagon-Like Peptide 1; Glucagon-Like Peptide-1 Receptor; Humans; Hypoglycemic Agents; Obesity | 2022 |
Impact of Pharmacists in Therapeutic Optimization Relative to the 2020 American Diabetes Association Standards of Medical Care in Diabetes Guidelines in Patients with Clinical Atherosclerotic Cardiovascular Disease.
In 2020, the American Diabetes Association (ADA) Standards of Medical Care in Diabetes Guidelines newly recommended adding a sodium-glucose cotransporter-2 (SGLT-2) inhibitor or a glucagon-like peptide 1 (GLP-1) receptor agonist in patients with both type 2 diabetes and atherosclerotic cardiovascular disease, regardless of hemoglobin A1c (HbA1c) levels. In this study, the primary objective was to assess the pharmacist's role in the therapeutic optimization of patients with both type 2 diabetes and atherosclerotic cardiovascular disease relative to the new recommendations. The secondary objectives were to assess other factors affecting therapeutic optimization and clinician familiarity with the recommendations. This study, conducted at the East Hawai.i Health Clinic, included 60 patients with type 2 diabetes and atherosclerotic cardiovascular disease. Anonymous surveys were sent to clinicians at the clinic to assess recommendation familiarity. Patients seen by a pharmacist were significantly more likely to be therapeutically optimized per the 2020 ADA guidelines than those not seen by a pharmacist. HbA1c and age also influenced SGLT-2/GLP-1 therapy use. All clinicians were more likely to prescribe SGLT-2/GLP-1 therapy for patients with uncontrolled HbA1c but were less likely to prescribe additional therapy for patients with controlled HbA1c, even in patients with previous atherosclerotic events. Topics: Cardiovascular Diseases; Diabetes Mellitus, Type 2; Glucagon-Like Peptide 1; Glucagon-Like Peptide-1 Receptor; Glycated Hemoglobin; Humans; Pharmacists; Sodium-Glucose Transporter 2 Inhibitors; United States | 2022 |
Determining When to Recommend Glucose-Lowering Drugs That Reduce Cardiovascular Risk.
Topics: Aged; Blood Glucose; Cardiovascular Diseases; Diabetes Mellitus, Type 2; Dipeptidyl-Peptidase IV Inhibitors; Female; Glucagon-Like Peptide 1; Glucose; Heart Disease Risk Factors; Humans; Hypoglycemic Agents; Male; Middle Aged; Sodium-Glucose Transporter 2 Inhibitors | 2022 |
Guidelines for When to Consider Mortality-Reducing Treatments for Patients With Type 2 Diabetes Mellitus.
Topics: Cardiovascular Diseases; Diabetes Mellitus, Type 2; Glucagon-Like Peptide 1; Humans; Hypoglycemic Agents; Kidney Diseases; Practice Guidelines as Topic; Risk Factors; Sodium-Glucose Transporter 2 Inhibitors | 2022 |
Glucose-Lowering Medications and Post-Dementia Survival in Patients with Diabetes and Dementia.
The effectiveness of glucose-lowering drugs (GLDs) is unknown among patients with dementia.. To analyze all-cause mortality among users of six GLDs in dementia and dementia-free subjects, respectively.. This was a longitudinal open-cohort registry-based study using data from the Swedish Dementia Registry, Total Population Register, and four supplemental registers providing data on dementia status, drug usage, confounders, and mortality. The cohort comprised 132,402 subjects with diabetes at baseline, of which 11,401 (8.6%) had dementia and 121,001 (91.4%) were dementia-free. Subsequently, comparable dementia - dementia-free pairs were sampled. Then, as-treated and intention-to-treat exposures to metformin, insulin, sulfonylurea, dipeptidyl-peptidase-4 inhibitors, glucagon-like peptide-1 analogues (GLP-1a), and sodium-glucose cotransporter-2 inhibitors (SGLT-2i) were analyzed in the parallel dementia and dementia-free cohorts. Confounding was addressed using inverse-probability weighting and propensity-score matching, and flexible parametric survival models were used to produce hazard ratios (HR) and 95% confidence intervals (CI) of the association between GLDs and all-cause mortality.. In the as-treated models, increased mortality was observed among insulin users with dementia (HR 1.34 [95%CI 1.24-1.45]) as well as in dementia-free subjects (1.54 [1.10-1.55]). Conversely, sulfonylurea was associated with higher mortality only in dementia subjects (1.19 [1.01-1.42]). GLP-1a (0.44 [0.25-0.78]) and SGLT-2i users with dementia (0.43 [0.23-0.80]) experienced lower mortality compared to non-users.. Insulin and sulfonylurea carried higher mortality risk among dementia patients, while GLP-1a and SGLT-2i were associated with lower risk. GLD-associated mortality varied between dementia and comparable dementia-free subjects. Further studies are needed to optimize GLD use in dementia patients. Topics: Dementia; Diabetes Mellitus, Type 2; Glucagon-Like Peptide 1; Glucose; Humans; Hypoglycemic Agents; Insulin; Sodium-Glucose Transporter 2 Inhibitors; Sulfonylurea Compounds | 2022 |
Oligomerization, albumin binding and catabolism of therapeutic peptides in the subcutaneous compartment: An investigation on lipidated GLP-1 analogs.
Lipidation, a common strategy to improve half-life of therapeutic peptides, affects their tendency to oligomerize, their interaction with plasmatic proteins, and their catabolism. In this work, we have leveraged the use of NMR and SPR spectroscopy to elucidate oligomerization propensity and albumin interaction of different analogs of the two marketed lipidated GLP-1 agonists liraglutide and semaglutide. As most lipidated therapeutic peptides are administered by subcutaneous injection, we have also assessed in vitro their catabolism in the SC tissue using the LC-HRMS-based SCiMetPep assay. We observed that oligomerization had a shielding effect against catabolism. At the same time, binding to albumin may provide only limited protection from proteolysis due to the higher unbound peptide fraction present in the subcutaneous compartment with respect to the plasma. Finally, identification of catabolites in rat plasma after SC dosing of semaglutide showed a good correlation with the in vitro data, with Tyr Topics: Albumins; Animals; Diabetes Mellitus, Type 2; Glucagon-Like Peptide 1; Half-Life; Hypoglycemic Agents; Liraglutide; Peptides; Rats | 2022 |
Rise in Postprandial GLP-1 Levels After Roux-en-Y Gastric Bypass: Involvement of the Vagus Nerve-Spleen Anti-inflammatory Axis in Type 2 Diabetic Rats.
The mechanism underlying postprandial glucagon-like peptide-1 (GLP-1) changes after metabolic surgery remains mostly unclarified. This investigation aimed to address whether the vagus nerve-spleen anti-inflammatory axis is involved in the rise in postprandial GLP-1 levels in type 2 diabetes mellitus (T2DM) rats following metabolic surgery.. T2DM rat model was established with a high-fat diet and a low dose of streptozotocin and subjected to Roux-en-Y gastric bypass (RYGB) and splenic denervation. A mixed-meal tolerance test for postprandial GLP-1 response was performed. TNF-α in the plasma, spleen, and ileum was measured by ELISA, and alpha 7 nicotinic acetylcholine receptor (α7nAChR) expression in the spleen was analyzed by Western blot.. Postprandial GLP-1 improvement by RYGB was accompanied by the reduction of TNF-α levels in spleen and ileum and up-regulation of splenic α7nAChR in T2DM rats. Splenic denervation abrogates a rise in postprandial GLP-1 levels in response to the mixed-meal challenge, along with higher TNF-α levels in spleen and ileum and down-regulation of splenicα7nAChR, compared with denervated sham rats.. Our results reveal that the vagus nerve-spleen anti-inflammatory axis mediates the rise of postprandial GLP-1 response after RYGB through lowering TNF-α contents in the intestinal tissue in T2DM rats. Topics: alpha7 Nicotinic Acetylcholine Receptor; Animals; Anti-Inflammatory Agents; Blood Glucose; Diabetes Mellitus, Experimental; Diabetes Mellitus, Type 2; Gastric Bypass; Glucagon-Like Peptide 1; Humans; Insulin; Obesity, Morbid; Rats; Spleen; Tumor Necrosis Factor-alpha; Vagus Nerve | 2022 |
Incidence and Predictors of Primary Nonadherence to Sodium Glucose Co-transporter 2 Inhibitors and Glucagon-Like Peptide 1 Agonists in a Large Integrated Healthcare System.
Newer glucose-lowering drugs, including sodium glucose co-transporter 2 inhibitors (SGLT2i) and GLP-1 agonists, have a key role in the pharmacologic management of type 2 diabetes. No studies have measured primary nonadherence for these two drug classes, defined as when a medication is prescribed for a patient but ultimately not dispensed to them.. To describe the incidence and predictors of primary nonadherence to SGLT2i (canagliflozin, empagliflozin) or GLP-1 agonists (dulaglutide, liraglutide, semaglutide) using a dataset that links electronic prescribing with health insurance claims.. A retrospective cohort design using data of adult patients from a large health system who had at least one prescription order for a SGLT2i or GLP-1 agonist between 2012 and 2019. We used mixed-effects multivariable logistic regression to determine associations between sociodemographic, clinical, and provider variables and primary nonadherence.. Primary medication nonadherence, defined as no dispensed claim within 30 days of an electronic prescription order for any drug within each medication class.. The cohort included 5146 patients newly prescribed a SGLT2i or GLP-1 agonist. The overall incidence of 30-day primary medication nonadherence was 31.8% (1637/5146). This incidence rate was 29.8% (n = 726) and 33.6% (n = 911) among those initiating a GLP-1 agonist and SGLT2i, respectively. Age ≥ 65 (aOR 1.37 (95% CI 1.09 to 1.72)), Black race vs White (aOR 1.29 (95% CI 1.02 to 1.62)), diabetic nephropathy (aOR 1.31 (95% CI 1.02 to 1.68)), and hyperlipidemia (aOR 1.18 (95% CI 1.01 to 1.39)) were associated with a higher odds of primary nonadherence. Female sex (aOR 0.86 (95% CI 0.75 to 0.99)), peripheral artery disease (aOR 0.73 (95% CI 0.56 to 0.94)), and having the index prescription ordered by an endocrinologist vs a primary care provider (aOR 0.76 (95% CI 0.61 to 0.95)) were associated with lower odds of primary nonadherence.. One third of patients prescribed SGLT2i or GLP-1 agonists in this sample did not fill their prescription within 30 days. Black race, male sex, older age, having greater baseline comorbidities, and having a primary care provider vs endocrinologist prescribe the index drug were associated with higher odds of primary nonadherence. Interventions targeting medication adherence for these newer drugs must consider primary nonadherence as a barrier to optimal clinical care. Topics: Adult; Canagliflozin; Delivery of Health Care, Integrated; Diabetes Mellitus, Type 2; Female; Glucagon-Like Peptide 1; Glucose; Humans; Hypoglycemic Agents; Incidence; Liraglutide; Male; Retrospective Studies; Sodium; Sodium-Glucose Transporter 2 Inhibitors; Symporters | 2022 |
A Potential Synbiotic Strategy for the Prevention of Type 2 Diabetes:
The disturbance of intestinal microorganisms and the exacerbation of type 2 diabetes (T2D) are mutually influenced. In this study, the effect of exopolysaccharides (EPS) from Topics: Animals; Bacterial Adhesion; Blood Glucose; Caco-2 Cells; Diabetes Mellitus, Type 2; Energy Metabolism; Gastrointestinal Microbiome; Glucagon-Like Peptide 1; Humans; Inflammation; Interleukin-10; Interleukin-6; Intestines; Lacticaseibacillus paracasei; Lactobacillus plantarum; Liver; Male; Mice; Mice, Inbred C57BL; Pancreas; Peptide YY; Polysaccharides, Bacterial; Random Allocation; Synbiotics; Tumor Necrosis Factor-alpha | 2022 |
Efficient synthesis of Aib
Glucagon-like peptide-1 (GLP-1) is a potential therapeutic agent for treating Type 2 diabetes, owing to its glucose-dependent capability to stimulate insulin secretion. Semaglutide is currently the best GLP-1 analogue; however, the Aib Topics: Diabetes Mellitus, Type 2; Glucagon-Like Peptide 1; Humans; Peptide Fragments; Peptides | 2022 |
Effects of luseogliflozin on the secretion of islet hormones and incretins in patients with type 2 diabetes.
The insufficient activity of insulin and the hyperactivity of glucagon are responsible for glucose intolerance in patients with type 2 diabetes. Whereas sodium-glucose cotransporter-2 (SGLT2) inhibitors improve blood glucose levels in patients with type 2 diabetes, their effects on the secretion profiles of glucagon and incretins remain unclear. Therefore, to investigate the effects of the SGLT2 inhibitor luseogliflozin on metabolic and endocrine profiles, 19 outpatients with type 2 diabetes were administered luseogliflozin for 12 weeks. It is of note that all subjects were treated only with diet and exercise therapy, and we were able to investigate the effects of luseogliflozin separately from the effects of other antidiabetic agents. Body weight, body fat mass, fat-free mass, and muscle mass were significantly reduced after 12 weeks of luseogliflozin administration. Glycosylated hemoglobin significantly decreased from the baseline of 8.2% ± 0.8% to 7.3% ± 0.7% (p < 0.0001). The meal tolerance test demonstrated that luseogliflozin significantly recovered glucose tolerance, accompanied by improved insulin resistance and β-cell function, whereas glucagon secretion was unaffected. Furthermore, GLP-1 secretion was significantly increased after luseogliflozin administration. Thus, luseogliflozin improved metabolic and endocrine profiles accompanied by increased GLP-1 secretion in type 2 diabetic patients without any antidiabetic medication, but did not affect glucagon secretion. Topics: Blood Glucose; Diabetes Mellitus, Type 2; Glucagon; Glucagon-Like Peptide 1; Glucose; Humans; Hypoglycemic Agents; Incretins; Sorbitol | 2022 |
The Protective Effect of Transit Bipartition and Its Modification Against Sleeve Gastrectomy-Related Esophagitis in a Rodent Model.
The protective effect of transit bipartition against esophagitis has not yet been proven. Thus, we investigate and compare the bariatric outcomes and esophagus' histological changes of sleeve gastrectomy (SG), SG with transit bipartition (SG-TB), and the proximal SG-TB (SG-PTB) in a rodent model.. This study included 45 diabetic Sprague-Dawley rats assigned to one of the four groups, SG-PTB (n = 15), SG-TB (n = 12), SG (n = 10), and SHAM (n = 8). Eight surviving rats from each group were included for further investigation. Histological analysis of the gastroesophageal junction was performed. Body weight, food intake, glucose control, and hormonal changes (glucagon-like peptide-1 and insulin) were assessed before and after surgery in all groups.. Preoperatively, no significant differences were observed in food intake, body weight, and fasting blood glucose levels among the groups. Postoperatively, the SG-PTB and SG-TB groups showed significantly superior glucose control compared to the SG group following the gavage of glucose (p < 0.05). Postoperatively, the SG-PTB and SG-TB groups had higher postoperative GLP-1 levels than postoperative SG and SHAM groups. More severe esophageal hyperpapillomatosis (EHP) of the esophageal section was observed in the SG group. The mucosal height of the SG group was significantly higher than that of the SG-PTB, SG-TB, and SHAM groups (p < 0.05).. The transit bipartition procedure may protect the distal esophagus from histological changes associated with esophagitis. Clinical studies are needed to confirm the anti-reflux effects of transit bipartition. Topics: Animals; Blood Glucose; Diabetes Mellitus, Type 2; Esophagitis; Gastrectomy; Glucagon-Like Peptide 1; Humans; Obesity, Morbid; Rats; Rats, Sprague-Dawley; Rodentia | 2022 |
Glucagon-Like Peptide 1 Receptor Agonists and Sodium-Glucose Cotransporter 2 Inhibitors and Risk of Nonalcoholic Fatty Liver Disease Among Patients With Type 2 Diabetes.
To determine whether glucagon-like peptide 1 receptor agonists (GLP-1 RA) and sodium-glucose cotransporter 2 (SGLT-2) inhibitors, separately, are associated with a decreased risk of nonalcoholic fatty liver disease (NAFLD) compared with dipeptidyl peptidase 4 (DPP-4) inhibitors among patients with type 2 diabetes.. We assembled two new-user, active comparator cohorts using the U.K. Clinical Practice Research Datalink. The first included 30,291 and 225,320 new users of GLP-1 RA and DPP-4 inhibitors, respectively. The second included 41,184 and 148,421 new users of SGLT-2 inhibitors and DPP-4 inhibitors, respectively. Cox proportional hazards models weighted using propensity score fine stratification were fit to estimate hazard ratios (HRs) with 95% CIs of NAFLD. We also determined whether the study drugs were associated with a decreased risk of hepatic transaminase elevation within restricted subcohorts.. GLP-1 RA were associated with a lower incidence of NAFLD with a wide CI compared with DPP-4 inhibitors (3.9 vs. 4.6 per 1,000 person-years, respectively; HR 0.86, 95% CI 0.73-1.01). SGLT-2 inhibitors were associated with a decreased risk of NAFLD (5.4 vs. 7.0 per 1,000 person-years, respectively; HR 0.78, 95% CI 0.68-0.89). In the restricted subcohorts, both GLP-1 RA and SGLT-2 inhibitors were associated with a decreased risk of hepatic transaminase elevation (HR 0.89, 95% CI 0.83-0.95, and HR 0.66, 95% CI 0.61-0.71).. SGLT-2 inhibitors, and possibly GLP-1 RA, may be associated with a decreased incidence of NAFLD and hepatic transaminase elevation among patients with type 2 diabetes. Topics: Diabetes Mellitus, Type 2; Dipeptidyl-Peptidase IV Inhibitors; Glucagon-Like Peptide 1; Glucagon-Like Peptide-1 Receptor; Glucose; Humans; Hypoglycemic Agents; Non-alcoholic Fatty Liver Disease; Sodium; Sodium-Glucose Transporter 2 Inhibitors; Transaminases | 2022 |
New developments in the prospects for GLP-1 therapy.
Topics: Diabetes Mellitus, Type 2; Glucagon-Like Peptide 1; Glucagon-Like Peptide-1 Receptor; Humans; Hypoglycemic Agents | 2022 |
Neprilysin inhibition improves intravenous but not oral glucose-mediated insulin secretion via GLP-1R signaling in mice with
Type 2 diabetes is associated with the upregulation of neprilysin, a peptidase capable of cleaving glucoregulatory peptides such as glucagon-like peptide-1 (GLP-1). In humans, use of the neprilysin inhibitor sacubitril in combination with an angiotensin II receptor blocker was associated with increased plasma GLP-1 levels and improved glycemic control. Whether neprilysin inhibition per se is mediating these effects remains unknown. We sought to determine whether pharmacological neprilysin inhibition on its own confers beneficial effects on glycemic status and β-cell function in a mouse model of reduced insulin secretion, and whether any such effects are dependent on GLP-1 receptor (GLP-1R) signaling. High-fat-fed male wild-type ( Topics: Aminobutyrates; Animals; Biphenyl Compounds; Diabetes Mellitus, Type 2; Glucagon-Like Peptide 1; Glucagon-Like Peptide-1 Receptor; Glucose; Insulin; Insulin Secretion; Male; Mice; Mice, Inbred C57BL; Mice, Knockout; Neprilysin | 2022 |
Comparison of renal outcomes between sodium glucose co-transporter 2 inhibitors and glucagon-like peptide 1 receptor agonists.
This study aimed to clarify the differences in how sodium glucose co-transporter 2 inhibitors (SGLT2i) and glucagon-like peptide 1 receptor agonists (GLP1Ra) influence kidney function in Japanese patients with type 2 diabetes mellitus (T2DM).. We retrospectively built two databases of patients with T2DM who visited the clinics of members of Kanagawa Physicians Association. We defined the renal composite outcome as either progression of albuminuria status and/or > 15% deterioration in estimated glomerular filtration rate (eGFR) per year. We used propensity score matching to compare patient outcomes after SGLT2i and GLP1Ra treatments.. Renal composite outcome incidence was lower in SGLT2i-treated patients than in GLP1Ra-treated patients. Topics: Diabetes Mellitus, Type 2; Female; Glucagon-Like Peptide 1; Glucagon-Like Peptide-1 Receptor; Glucose; Humans; Hypoglycemic Agents; Kidney; Male; Retrospective Studies; Sodium; Sodium-Glucose Transporter 2 Inhibitors; Symporters | 2022 |
Glucagon-Like Peptide 1 Receptor Agonists and Risk of Anaphylactic Reaction Among Patients With Type 2 Diabetes: A Multisite Population-Based Cohort Study.
Case reports and a pharmacovigilance analysis have linked glucagon-like peptide 1 receptor agonists (GLP-1 RAs) with anaphylactic reactions, but real-world evidence for this possible association is lacking. Using databases from the United Kingdom (Clinical Practice Research Datalink) and the United States (Medicare, Optum (Optum, Inc., Eden Prairie, Minnesota), and IBM MarketScan (IBM, Armonk, New York)), we employed a new-user, active comparator study design wherein initiators of GLP-1 RAs were compared with 2 different active comparator groups (initiators of dipeptidyl peptidase 4 (DPP-4) inhibitors and initiators of sodium-glucose cotransporter 2 (SGLT-2) inhibitors) between 2007 and 2019. Propensity score fine stratification weighted Cox proportional hazards models were fitted to estimate hazard ratios (HRs) and 95% confidence intervals (CIs) for an anaphylactic reaction. Database-specific HRs were pooled using random-effects models. Compared with the use of DPP-4 inhibitors (n = 1,641,520), use of GLP-1 RAs (n = 324,098) generated a modest increase in the HR for anaphylactic reaction, with a wide 95% CI (36.9 per 100,000 person-years vs. 32.1 per 100,000 person-years, respectively; HR = 1.15, 95% CI: 0.94, 1.42). Compared with SGLT-2 inhibitors (n = 366,067), GLP-1 RAs (n = 259,929) were associated with a 38% increased risk of anaphylactic reaction (40.7 per 100,000 person-years vs. 29.4 per 100,000 person-years, respectively; HR = 1.38, 95% CI: 1.02, 1.87). In this large, multisite population-based cohort study, GLP-1 RAs were associated with a modestly increased risk of anaphylactic reaction when compared with DPP-4 inhibitors and SGLT-2 inhibitors. Topics: Aged; Anaphylaxis; Cohort Studies; Diabetes Mellitus, Type 2; Dipeptidyl-Peptidase IV Inhibitors; Glucagon-Like Peptide 1; Humans; Hypoglycemic Agents; Medicare; Sodium-Glucose Transporter 2 Inhibitors; United States | 2022 |
Real-world evaluation of insulin requirements after GLP1 agonist or SGLT2 inhibitor initiation and titration.
To describe insulin adjustments made following initiation of glucagon-like peptide 1 agonist (GLP1a) or sodium-glucose cotransporter-2 inhibitor (SGLT2i) therapy in patients within a primary care setting.. This was a multicenter, retrospective cohort study conducted at an academic health system. Adults with type 2 diabetes mellitus initiated on a GLP1a or SGLT2i while on insulin and managed by an ambulatory care pharmacist were included. The primary endpoint was the percent change in total daily insulin dose at specified time points (2 weeks, 4 weeks, 6 weeks, 3 months, and 6 months) after agent initiation. The secondary endpoints included a glycosylated hemoglobin (HbA1c) value of less than 8%, change from baseline HbA1c, and safety profiles of GLP1a therapy and SGLT2i therapy.. Of the 150 patients included, 123 were initiated on a GLP1a and 27 on an SGLT2i. After 6 months, GLP1a initiation had resulted in a mean 23.5% decrease (P < 0.001) in insulin dosage and SGLT2i resulted in a mean 0.2% increase (P = 0.20). Insulin dosage reduction with GLP1a use was significantly different between baseline and each time point (P < 0.001). About 72% of patients initiated on a GLP1a and 59% of those initiated on an SGLT2i achieved an HbA1c value of less than 8%. The mean absolute change from baseline in HbA1c concentration was -1.7% with GLP1a use and -1.5% with SGLT2i use (P < 0.001 for both comparisons with baseline values). Hypoglycemia occurred in 21% of patients on a GLP1a and 11% of those on an SGLT2i.. After GLP1a initiation, the mean total daily insulin dose decreased by 23.5%; after SGLT2i initiation, insulin requirements increased by a mean of 0.2%. These results will help guide insulin adjustments after initiation of these medications. Topics: Adult; Diabetes Mellitus, Type 2; Glucagon-Like Peptide 1; Glycated Hemoglobin; Humans; Hypoglycemic Agents; Insulin; Retrospective Studies; Sodium-Glucose Transporter 2 Inhibitors | 2022 |
Spinal cord-wide structural disruption in type 2 diabetes rescued by exenatide "a glucagon-like peptide-1 analogue" via down-regulating inflammatory, oxidative stress and apoptotic signaling pathways.
The mechanisms of spinal cord-wide structural and functional disruption in diabetic patients remain elusive. This study evaluated histopathological alterations of the spinal cord cytoarchitecture in T2DM model of rats and assessed the potential ameliorating effect of exenatide "a potent GLP-1 analogue". Thirty male rats were allocated into three groups; I (control), II (Diabetic): T2DM was induced by high fat diet for 8 weeks followed by a single I.P injection of STZ (25 mg/kg BW) and III (Diabetic/Exenatide): T2DM rats injected with exenatide (10 μg/Kg, S.C. twice daily for 2 weeks). Neurobehavioral sensory and motor tests were carried out and glycemic control biomarkers and indices of insulin resistance and sensitivity were measured. In addition, the spinal cord was processed for histological and immunohistochemical studies besides assessing its tissue homogenate levels of pro-inflammatory/anti-inflamatory cytokines and oxidant/antioxidant biomarkers. Moreover, RT-qPCR was performed to measure the expression of proapoptotic/antiapoptotic and neurotrophic genes. The diabetic rats exhibited thermal hyperalgesia, mechanical allodynia and decreased locomotor activity along with increased serum glucose, insulin, HbA1c, HOMA-IR while, quantitative insulin sensitivity check index (QUICKI) was decreased. Also, IL-1β NF-kB, MDA increased while IL-10, SOD activity and β-endorphin decreased in the spinal tissue. Up regulation of caspase-3 and down regulation of Bcl-2, nerve growth factor (NGF) and glial cell-derived neurotrophic (GDNF) in diabetic rats. Also, they exhibited histopathological changes and increased CD68 positive microglia and Bax immunoreactivity in the spinal cord. Subsequent to exenatide treatment, most biomolecular, structural and functional impairments of the spinal cord were restored in the diabetic rats. In conclusion, the neuro-modulating effect of exenatide against diabetic-induced spinal cord affection warrants the concern about its therapeutic relevance in confronting the devastating diabetic neuropathic complications. Topics: Animals; Diabetes Mellitus, Experimental; Diabetes Mellitus, Type 2; Exenatide; Glucagon-Like Peptide 1; Humans; Hyperalgesia; Male; Oxidative Stress; Rats; Signal Transduction; Spinal Cord | 2022 |
Pancreatic cancer-associated diabetes mellitus is characterized by reduced β-cell secretory capacity, rather than insulin resistance.
The early distinction of pancreatic cancer associated diabetes (PaCDM) in patients with elderly diabetes is critical. However, PaCDM and type 2 diabetes mellitus (T2DM) remain indistinguishable. We aim to address the differences between the pancreatic and gut endocrine hormones of patients with PaCDM and T2DM.. A total of 44 participants underwent mixed meal tolerance test (MMTT). Fasting and postprandial concentrations of insulin, C-peptide, glucagon, pancreatic polypeptide (PP), glucagon-like peptide-1 (GLP-1), and gastric inhibitory peptide (GIP) were measured. Insulin sensitivity and secretion indices were calculated. One-way ANOVA with post-hoc analysis was used for statistical analysis.. Insulin and C-peptide responses to MMTT were blunted in PaCDM patients compared with T2DM. Baseline concentrations and AUCs differed. PaCDM patients showed lower insulin secretion capacity but better insulin sensitivity than T2DM patients. The peak concentration and AUC of PP in T2DM group were higher than healthy controls, but in accordance with PaCDM. PaCDM patients presented lower baseline GLP-1 concentration than T2DM patients. No between-group differences were found for glucagon and GIP.. PaCDM patients had a lower baseline and postprandial insulin and C-peptide secretion than T2DM patients. Reduced insulin secretion and improved peripheral sensitivity were found in PaCDM patients compared with T2DM. Topics: Aged; Blood Glucose; C-Peptide; Diabetes Mellitus, Type 2; Gastric Inhibitory Polypeptide; Glucagon; Glucagon-Like Peptide 1; Humans; Insulin; Insulin Resistance; Pancreatic Neoplasms | 2022 |
Incretin Hypersecretion in Gestational Diabetes Mellitus.
Incretins are crucial stimulators of insulin secretion following food intake. Data on incretin secretion and action during pregnancy are sparse.. The aim of the study was to investigate the incretin response during an oral glucose tolerance test (OGTT) in pregnant women with and without gestational diabetes mellitus (GDM).. We analyzed data from the ongoing observational PREG study (NCT04270578).. The study was conducted at the University Hospital Tübingen.. We examined 167 women (33 with GDM) during gestational week 27 ± 2.2.. Subjects underwent 5-point OGTT with a 75-g glucose load.. We assessed insulin secretion and levels of total glucagon-like peptide-1 (GLP-1), glucose-dependent insulinotropic peptide (GIP), glicentin, and glucagon during OGTT. Linear regression was used to analyze the relation of GLP-1 and glucose with insulin secretion and the association of incretin levels on birth outcome.. Insulin secretion was significantly lower in women with GDM (P < 0.001). Postload GLP-1 and GIP were ~20% higher in women with GDM (all P < 0.05) independent of age, body mass index, and gestational age. GLP-1 increase was associated with insulin secretion only in GDM, but not in normal glucose tolerance. Postprandial GLP-1 levels were negatively associated with birth weight.. The more pronounced GLP-1 increase in women with GDM could be part of a compensatory mechanism counteracting GLP-1 resistance. Higher GLP-1 levels might be protective against fetal overgrowth. Topics: Blood Glucose; Diabetes Mellitus, Type 2; Diabetes, Gestational; Female; Fetal Macrosomia; Gastric Inhibitory Polypeptide; Glucagon-Like Peptide 1; Glucose; Humans; Incretins; Insulin; Pregnancy | 2022 |
Effects of Glucagon-like peptide 1 (GLP-1) analogs in the hippocampus.
The glucagon-like peptide-1 (GLP-1) is a pleiotropic hormone very well known for its incretin effect in the glucose-dependent stimulation of insulin secretion. However, GLP-1 is also produced in the brain, and it displays critical roles in neuroprotection by activating the GLP-1 receptor signaling pathways. GLP-1 enhances learning and memory in the hippocampus, promotes neurogenesis, decreases inflammation and apoptosis, modulates reward behavior, and reduces food intake. Its pharmacokinetics have been improved to enhance the peptide's half-life, enhancing exposure and time of action. The GLP-1 agonists are successfully in clinical use for the treatment of type-2 diabetes, obesity, and clinical evaluation for the treatment of neurodegenerative diseases. Topics: Diabetes Mellitus, Type 2; Glucagon-Like Peptide 1; Glucagon-Like Peptide-1 Receptor; Hippocampus; Humans; Incretins; Peptide Fragments | 2022 |
Development of drug alone and carrier-based GLP-1 dry powder inhaler formulations.
Topics: Administration, Inhalation; Aerosols; Diabetes Mellitus, Type 2; Drug Carriers; Dry Powder Inhalers; Excipients; Glucagon-Like Peptide 1; Humans; Particle Size; Powders | 2022 |
Novel glucagon-like peptide-1 analogue exhibits potency-driven G-protein biased agonism with promising effects on diabetes and diabetic dry eye syndrome.
Topics: Animals; Diabetes Mellitus, Experimental; Diabetes Mellitus, Type 2; Dry Eye Syndromes; Glucagon-Like Peptide 1; Glucagon-Like Peptide-1 Receptor; GTP-Binding Proteins; Hypoglycemic Agents; Mice | 2022 |
Small-molecule albumin ligand modification to enhance the anti-diabetic ability of GLP-1 derivatives.
Glucagon-like peptide-1 (GLP-1) receptor agonists modified with albumin ligands which can specificity bind to the human serum albumin (HSA) was an efficient strategy to prolong the half-time of GLP-1. Herein, we investigated the effect of small-molecule albumin ligand modification on the hypoglycemic activities of GLP-1 derivatives. Two GLP-1 derivatives MPA-C12-GLP-1 and Rhein-C12-GLP-1 were achieved by modification of the side chain amino of lysine in position 26 of the Arg34-GLP-1(7-37)-OH with Rhein and 3-Maleimidopropionic acid respectively using 12-aminolauric acid as a linker, and its specific albumin-conjugating characteristics, pharmaceutical characterization, and the antidiabetic effects were investigated. In vitro level, two GLP-1 derivatives demonstrated a higher binding capacity to GLP-1 receptor than that of Arg34-GLP-1(7-37)-OH. Interestingly, although the binding ability of MPA-C12-GLP-1 was equal to liraglutide, the binding ability of Rhein-C12-GLP-1 was 10-fold higher than liraglutide. In vivo level, the two GLP-1 derivatives can significantly increase their glucose tolerance and prolong their half-life in ICR mice, and they were also superior to GLP-1 in controlling glucose homeostasis and suppression of food intake and water consumption in db/db mice. Importantly, the two GLP-1 derivatives showed comparable efficacy to liraglutide for the therapy of type 2 diabetes mellitus. The in vitro INS-1 cells toxicity and the in vivo hepatotoxicity indicated that the Rhein-C12-GLP-1 was a safe candidate for the therapy of type 2 diabetes, and the serum biomarkers determination results showed that the Rhein-modified GLP-1 could significantly improve the HbA Topics: Albumins; Animals; Blood Glucose; Diabetes Mellitus, Type 2; Glucagon-Like Peptide 1; Hypoglycemic Agents; Ligands; Mice; Mice, Inbred C57BL; Mice, Inbred ICR | 2022 |
Structural insights into multiplexed pharmacological actions of tirzepatide and peptide 20 at the GIP, GLP-1 or glucagon receptors.
Glucose homeostasis, regulated by glucose-dependent insulinotropic polypeptide (GIP), glucagon-like peptide-1 (GLP-1) and glucagon (GCG) is critical to human health. Several multi-targeting agonists at GIPR, GLP-1R or GCGR, developed to maximize metabolic benefits with reduced side-effects, are in clinical trials to treat type 2 diabetes and obesity. To elucidate the molecular mechanisms by which tirzepatide, a GIPR/GLP-1R dual agonist, and peptide 20, a GIPR/GLP-1R/GCGR triagonist, manifest their multiplexed pharmacological actions over monoagonists such as semaglutide, we determine cryo-electron microscopy structures of tirzepatide-bound GIPR and GLP-1R as well as peptide 20-bound GIPR, GLP-1R and GCGR. The structures reveal both common and unique features for the dual and triple agonism by illustrating key interactions of clinical relevance at the near-atomic level. Retention of glucagon function is required to achieve such an advantage over GLP-1 monotherapy. Our findings provide valuable insights into the structural basis of functional versatility of tirzepatide and peptide 20. Topics: Cryoelectron Microscopy; Diabetes Mellitus, Type 2; Gastric Inhibitory Polypeptide; Glucagon; Glucagon-Like Peptide 1; Glucagon-Like Peptide-1 Receptor; Glucose; Humans; Peptides; Receptors, G-Protein-Coupled; Receptors, Glucagon | 2022 |
Explore the Link between the Improvement of Metabolic Indicators in Diabetic Rats with Sleeve Gastrectomy and Changes in the Composition of Intestinal Flora.
Diabetes mellitus (DM) has become a major medical and health problem in my country and even the world. Doctors and patients have gradually realized that a new type of metabolic surgery is a way to treat diabetes. The operation is relatively simple, and the effect of the operation is no less than that of the gastric shunt. The initial hypothesis could not fully explain the blood pressure and blood sugar reduction mechanism in waist and abdominal surgery. According to requirements, they were divided into the sleeve gastrectomy group (SG group, Topics: Animals; Blood Glucose; Body Weight; Diabetes Mellitus, Experimental; Diabetes Mellitus, Type 2; Gastrectomy; Gastrointestinal Microbiome; Glucagon-Like Peptide 1; Humans; Rats; RNA, Messenger | 2022 |
In CV disease, GLP-1 RAs and SGLT2 inhibitors reduce CV mortality.
Kanie T, Mizuno A, Takaoka Y, et al. Topics: Cardiovascular Diseases; Diabetes Mellitus, Type 2; Dipeptidyl-Peptidase IV Inhibitors; Glucagon-Like Peptide 1; Humans; Hypoglycemic Agents; Sodium-Glucose Transporter 2 Inhibitors | 2022 |
Serum bile acid response to oral glucose is attenuated in patients with early type 2 diabetes and correlates with 2-hour plasma glucose in individuals without diabetes.
To determine the serum bile acid (BA) response to 75-g oral glucose in individuals without diabetes, and whether this is attenuated in patients with 'early' type 2 diabetes (T2D) and related to the glycaemic response at 2 hours in either group.. Forty newly diagnosed, treatment-naïve Han Chinese T2D subjects and 40 age-, gender-, and body mass index-matched controls without T2D ingested a 75-g glucose drink after an overnight fast. Plasma glucose and serum concentrations of total and individual BAs, fibroblast growth factor-19 (FGF-19), total glucagon-like peptide-1 (GLP-1), and insulin, were measured before and 2 hours after oral glucose.. Fasting total BA levels were higher in T2D than control subjects (P < .05). At 2 hours, the BA profile exhibited a shift from baseline in both groups, with increases in conjugated BAs and/or decreases in unconjugated BAs. There were increases in total BA and FGF-19 levels in control (both P < .05), but not T2D, subjects. Plasma glucose concentrations at 2 hours related inversely to serum total BA levels in control subjects (r = -0.42, P = .006). Total GLP-1 and the insulin/glucose ratio were increased at 2 hours in both groups, and the magnitude of the increase was greater in control subjects.. The serum BA response to a 75-g oral glucose load is attenuated in patients with 'early' T2D, as is the secretion of FGF-19 and GLP-1, while in individuals without T2D it correlates with 2-hour plasma glucose levels. These observations support a role for BAs in the regulation of postprandial glucose metabolism. Topics: Bile Acids and Salts; Blood Glucose; Diabetes Mellitus, Type 2; Fibroblast Growth Factors; Glucagon-Like Peptide 1; Glucose; Humans; Insulin | 2022 |
The efficacy of single pharmacist medication review among type II diabetic patients who take six chronic medications or more: a case-control study.
Pharmacist medication review has been implemented in many health organizations throughout the world in an attempt to alleviate the underlying risk of polypharmacy in elderly patients. These consultations are often frequent and prolonged, and are thus associated with increased costs. To date, data regarding the most effective way to utilize pharmacist consultations for the improvement of health status is scant.. To evaluate the effectiveness of a single pharmacist consultation on changes in chronic medication regimes and on selected outcomes of diabetes 1-year after the consultation.. A case-control study included an intervention group of 740 patients who had pharmacist consultations and a reference group of 1476 matched patients who did not have a pharmacist consultation. 1-year outcome measures were compared including changes in medications, improved safety, and objective variables such as Hba1c, blood pressure, and lipid profile.. In the pharmacist consultation group, there were significantly more treatment changes ([mean 1.5 vs. 0.7, p < 0.001 medications were stopped], and [mean 1.3 vs. 0.4, p < 0.05 medications were started]). Patient safety improved with a general reduction in opiates and benzodiazepines ([50.0% vs. 31.6%, p < 0.05 opioids were stopped] and [58.8% vs 43.8%, p < 0.001 benzodiazepines were stopped]). Sulfonylurea treatment reduced (10.7% vs. 3.6%, p < 0.05 patients who stopped Sulfonylurea) and Glucagon-like peptide-1 receptor agonists (GLP-1) increased (16.4% vs. 11.2%, p < 0.001 patients who started GLP-1). Additionally, HbA1c levels showed a small decrease in the pharmacist consultation group ([- 0.18 ± 1.11] vs. [- 0.051 ± 0.80], p = 0.0058) but no significant differences were found regarding blood pressure or lipids profile.. A single pharmacist consultation beneficially impacted specific clinical and patient safety outcomes. Pharmacist consultations may thus help resolve polypharmacy complexities in primary care. Topics: Aged; Benzodiazepines; Case-Control Studies; Diabetes Mellitus, Type 2; Glucagon-Like Peptide 1; Glycated Hemoglobin; Humans; Israel; Medication Review; Pharmacists; Polypharmacy | 2022 |
Association of Glucagon-Like Peptide-1 Receptor Agonist vs Dipeptidyl Peptidase-4 Inhibitor Use With Mortality Among Patients With Type 2 Diabetes and Advanced Chronic Kidney Disease.
Glucagon-like peptide-1 (GLP-1) receptor agonist use is associated with reduced mortality and improved cardiovascular outcomes in the general population with diabetes. Dipeptidyl peptidase-4 (DPP-4) inhibitors are commonly used antidiabetic agents for patients with advanced-stage chronic kidney disease (CKD). The association of these 2 drug classes with outcomes among patients with diabetes and advanced-stage CKD or end-stage kidney disease (ESKD) is not well understood.. To assess whether use of GLP-1 receptor agonists in a population with diabetes and advanced-stage CKD or ESKD is associated with better outcomes compared with use of DPP-4 inhibitors.. This retrospective cohort study used data on patients with type 2 diabetes and stage 5 CKD or ESKD obtained from the National Health Insurance Research Database of Taiwan. The study was conducted between January 1, 2012, and December 31, 2018. Data were analyzed from June 2020 to July 2021.. Treatment with GLP-1 receptor agonists compared with treatment with DPP-4 inhibitors.. All-cause mortality, sepsis- and infection-related mortality, and mortality related to major adverse cardiovascular and cerebrovascular events were compared between patients treated with GLP-1 receptor agonists and patients treated with DPP-4 inhibitors. Propensity score weighting was used to mitigate the imbalance among covariates between the groups.. Of 27 279 patients included in the study, 26 578 were in the DPP-4 inhibitor group (14 443 [54.34%] male; mean [SD] age, 65 [13] years) and 701 in the GLP-1 receptor agonist group (346 [49.36%] male; mean [SD] age, 59 [13] years). After weighting, the use of GLP-1 receptor agonists was associated with lower all-cause mortality (hazard ratio [HR], 0.79; 95% CI, 0.63-0.98) and lower sepsis- and infection-related mortality (HR, 0.61; 95% CI, 0.40-0.91). Subgroup analysis demonstrated a lower risk of mortality associated with use of GLP-1 receptor agonists compared with DDP-4 inhibitors among patients with cerebrovascular disease (HR, 0.33; 95% CI, 0.12-0.86) than among those without cerebrovascular disease (HR, 0.89; 95% CI, 0.71-1.12) (P = .04 for interaction).. Treatment with GLP-1 receptor agonists was associated with lower all-cause mortality among patients with type 2 diabetes, advanced-stage CKD, and ESKD than was treatment with DPP-4 inhibitors. Additional well-designed, prospective studies are needed to confirm the potential benefit of GLP-1 receptor agonist treatment for patients with advanced CKD or ESKD. Topics: Aged; Cohort Studies; Diabetes Mellitus, Type 2; Dipeptidyl-Peptidase IV Inhibitors; Dipeptidyl-Peptidases and Tripeptidyl-Peptidases; Female; Glucagon-Like Peptide 1; Glucagon-Like Peptide-1 Receptor; Humans; Hypoglycemic Agents; Kidney Failure, Chronic; Male; Middle Aged; Renal Insufficiency, Chronic; Retrospective Studies; Sepsis; Sodium-Glucose Transporter 2 Inhibitors; Taiwan | 2022 |
CAPTURE: A cross-sectional study on the prevalence of cardiovascular disease in adults with type 2 diabetes in Italy.
The prevalence of type 2 diabetes (T2D) in Italy is increasing and cardiovascular disease (CVD) represents the leading cause of death in this population. CAPTURE was a multinational, multicentre, non-interventional, cross-sectional study assessing the prevalence of CVD, atherosclerotic CVD (AsCVD) and CVD subtypes among patients with T2D, across 13 countries. Here we report the results from Italy.. Overall, 816 patients with T2D (median age, 69 years [interquartile range: 62-75]; median duration of diabetes, 11.2 years [interquartile range: 5.7-18.7]) were recruited during routine clinical visits at secondary care centres in Italy between December 2018-September 2019. The prevalence of CVD was estimated at 38.8%, largely accounted for by AsCVD (33.1%). The most prevalent CVD subtype was coronary heart disease (20.8%), followed by carotid artery disease (13.2%). Most patients (85.9%) were prescribed oral glucose-lowering agents (GLAs), particularly biguanide (76.7%). Insulin use was higher in patients with CVD (41.3%) than in patients without CVD (32.9%). Sodium-glucose co-transporter-2 inhibitors (SGLT2is) and glucagon-like peptide-1 receptor agonists (GLP-1 RAs) were prescribed to 20.2% vs 14.6%, and 14.5% vs 16.6% of patients with CVD compared to those without CVD, respectively.. The results show that, in Italy, more than one in three patients with T2D attending secondary care centres have CVD, 85% of whom have AsCVD, yet only a minority are treated with SGLT2is and GLP-1 RAs, in discordance with the recommendations of current national and international guidelines. Topics: Adult; Aged; Cardiovascular Diseases; Cross-Sectional Studies; Diabetes Mellitus, Type 2; Glucagon-Like Peptide 1; Glucagon-Like Peptide-1 Receptor; Glucose; Humans; Hypoglycemic Agents; Middle Aged; Prevalence; Sodium-Glucose Transporter 2 Inhibitors | 2022 |
Greater Adherence and Persistence with Injectable Dulaglutide Compared with Injectable Semaglutide at 1-Year Follow-up: Data from US Clinical Practice.
Greater medication adherence and persistence have been associated with improved glycemic control in patients with type 2 diabetes mellitus. This study compared adherence, persistence, and treatment patterns among patients naïve to glucagon-like peptide 1 receptor agonists initiating once-weekly injectable treatment with dulaglutide versus semaglutide over 6-month (6M) and 12-month (12M) follow-up periods.. This retrospective, observational cohort study used administrative claims data from three IBM MarketScan research databases. Data from adult patients with type 2 diabetes newly initiating treatment with dulaglutide or semaglutide between January 2018 and January 2020 (index date was defined as the earliest fill date), without evidence of glucagon-like peptide 1 receptor agonist use in the 6M baseline period, and with continuous enrollment in the 6M baseline and 6M or 12M follow-up period were included. Dulaglutide initiators were propensity score-matched, in a 1:1 ratio, to semaglutide initiators in each 6M and 12M follow-up cohort (26,284 and 13,837 pairs, respectively).. In the matched cohorts, baseline characteristics were balanced; the mean age was 53 years, and 50% of patients were women. Compared to semaglutide initiators, dulaglutide initiators were more adherent (6M, 63.4% vs 47.8%; 12M, 54.4% vs 43.3%; both, P < 0.0001), more persistent on therapy (6M, 72% vs 62%, 12M, 55.5% vs 45.3%, both, P < 0.001), and had more mean days of persistence (6M, 145 vs 132, 12M, 254.3 vs 220.7; both, P < 0.001).. At both 6M and 12M follow-up, dulaglutide initiators had significantly greater adherence and greater persistence compared with matched semaglutide initiators. Topics: Adult; Diabetes Mellitus, Type 2; Female; Glucagon-Like Peptide 1; Glucagon-Like Peptides; Humans; Hypoglycemic Agents; Immunoglobulin Fc Fragments; Male; Middle Aged; Recombinant Fusion Proteins; Retrospective Studies | 2022 |
GLP-1RAs for Ischemic Stroke Prevention in Patients With Type 2 Diabetes Without Established Atherosclerotic Cardiovascular Disease.
We assessed the effect of glucagon-like peptide 1 receptor agonists (GLP-1RAs) on ischemic stroke prevention in the Asian population with type 2 diabetes (T2D) without established cardiovascular disease.. This retrospective cohort study examined data obtained from the Taiwan National Health Insurance Research Database for the period from 1998 to 2018. The follow-up ended upon the occurrence of hospitalization for ischemic stroke. The median follow-up period was 3 years. The effect of GLP-1RA exposure time on the development of hospitalization for ischemic stroke was assessed.. The GLP-1RA and non-GLP-1RA user groups both included 6,534 patients. Approximately 53% of the patients were women, and the mean age was 49 ± 12 years. The overall risk of ischemic stroke hospitalization for GLP-1RA users was not significantly lower than that for GLP-1RA nonusers (adjusted hazard ratio [HR] 0.69 [95% CI 0.47-1.00]; P = 0.0506), but GLP-1RA users with a >251-day supply during the study period had a significantly lower risk of ischemic stroke hospitalization than GLP-1RA nonusers (adjusted HR 0.28 [95% CI 0.11-0.71]). Higher cumulative dose of GLP-1 RAs (>1,784 mg) was associated with significantly lower risk of ischemic stroke hospitalization. The subgroup analyses defined by various baseline features did not reveal significant differences in the observed effect of GLP-1RAs.. Longer use and higher dose of GLP-1 RAs were associated with a decreased risk of hospitalization for ischemic stroke among Asian patients with T2D who did not have established atherosclerotic cardiovascular diseases, but who did have dyslipidemia or hypertension. Topics: Adult; Atherosclerosis; Cardiovascular Diseases; Diabetes Mellitus, Type 2; Female; Glucagon-Like Peptide 1; Glucagon-Like Peptide-1 Receptor; Humans; Hypoglycemic Agents; Ischemia; Ischemic Stroke; Male; Middle Aged; Retrospective Studies | 2022 |
A Horse, a Jockey, and a Therapeutic Dilemma: Choosing the Best Option for a Patient with Diabetes and Coronary Artery Disease.
Current guidelines for the management of hyperglycemia recommend the use of agents with proven cardiovascular (CV) benefit in patients with type 2 diabetes (T2D) and established CV disease. Although both glucagon-like peptide 1 receptor agonists (GLP-1 RA) and sodium-glucose co-transporter 2 inhibitors (SGLT2i) have been shown to reduce the risk of major adverse CV events (MACE) in high-risk populations with T2D, the ideal choice between the two classes for people with coronary artery disease remains controversial. SGLT2i reduce CV risk primarily through hemodynamic effects and changes in energy metabolism, making them the first choice in cases where heart failure or chronic kidney disease predominates. On the other hand, GLP-1 RA exert powerful anti-atherogenic properties that are the main drivers of their cardioprotection, and seem to have a consistent benefit in the atherosclerotic components of MACE. However, most people with diabetes and CV disease could take advantage of the complementary effects of the two drug categories on glycemic control, body weight, and diabetic complications. Future mechanistic studies and clinical head-to-head trials are expected to shed more light on this intriguing clinical dilemma and provide clear guidance for daily practice. Topics: Animals; Cardiovascular Diseases; Coronary Artery Disease; Diabetes Mellitus, Type 2; Glucagon-Like Peptide 1; Horses; Humans; Hypoglycemic Agents; Sodium-Glucose Transporter 2 Inhibitors | 2022 |
The alpha-7 nicotinic acetylcholine receptor agonist GTS-21 engages the glucagon-like peptide-1 incretin hormone axis to lower levels of blood glucose in db/db mice.
To establish if alpha-7 nicotinic acetylcholine receptor (α7nAChR) agonist GTS-21 exerts a blood glucose-lowering action in db/db mice, and to test if this action requires coordinate α7nAChR and GLP-1 receptor (GLP-1R) stimulation by GTS-21 and endogenous GLP-1, respectively.. Blood glucose levels were measured during an oral glucose tolerance test (OGTT) using db/db mice administered intraperitoneal GTS-21. Plasma GLP-1, peptide tyrosine tyrosine 1-36 (PYY1-36), glucose-dependent insulinotropic peptide (GIP), glucagon, and insulin levels were measured by ELISA. A GLP-1R-mediated action of GTS-21 that is secondary to α7nAChR stimulation was evaluated using α7nAChR and GLP-1R knockout (KO) mice, or by co-administration of GTS-21 with the dipeptidyl peptidase-4 inhibitor, sitagliptin, or the GLP-1R antagonist, exendin (9-39). Insulin sensitivity was assessed in an insulin tolerance test.. Single or multiple dose GTS-21 (0.5-8.0 mg/kg) acted in a dose-dependent manner to lower levels of blood glucose in the OGTT using 10-14 week-old male and female db/db mice. This action of GTS-21 was reproduced by the α7nAChR agonist, PNU-282987, was enhanced by sitagliptin, was counteracted by exendin (9-39), and was absent in α7nAChR and GLP-1R KO mice. Plasma GLP-1, PYY1-36, GIP, glucagon, and insulin levels increased in response to GTS-21, but insulin sensitivity, body weight, and food intake were unchanged.. α7nAChR agonists improve oral glucose tolerance in db/db mice. This action is contingent to coordinate α7nAChR and GLP-1R stimulation. Thus α7nAChR agonists administered in combination with sitagliptin might serve as a new treatment for type 2 diabetes. Topics: alpha7 Nicotinic Acetylcholine Receptor; Animals; Benzylidene Compounds; Blood Glucose; Diabetes Mellitus, Type 2; Female; Gastric Inhibitory Polypeptide; Glucagon; Glucagon-Like Peptide 1; Glucagon-Like Peptide-1 Receptor; Glucose Tolerance Test; Humans; Incretins; Insulin; Insulin Resistance; Male; Mice; Mice, Knockout; Nicotinic Agonists; Pyridines; Sitagliptin Phosphate; Tyrosine | 2022 |
The Effect and Mechanism of Duodenal-Jejunal Bypass to Treat Type 2 Diabetes Mellitus in a Rat Model.
Bariatric surgery can treat obesity and T2DM, but the specific mechanism is unknown. This study investigated the effect and possible mechanism of duodenal-jejunal bypass (DJB) to treat T2DM.. A T2DM rat model was established using a high-fat, high-sugar diet and a low dose of streptozotocin. DJB surgery and a sham operation (SO) were performed to analyze the effects on glucose homeostasis, lipid metabolism, and inflammation changes. Furthermore, the glucagon-like peptide-1 (GLP-1) in the ileum and the markers of endoplasmic reticulum stress (ERS) in the pancreas were examined after the surgery. The insulinoma cells (INS-1) were divided into three groups; group A was cultured with a normal sugar content (11.1 mmol/L), group B was cultured with fluctuating high glucose (11.1 mmol/L alternating with 33.3 mmol/L), and group C was cultured with fluctuating high glucose and exendin-4 (100 nmol/L). The cells were continuously cultured for 7 days in complete culture medium. The viability of the INS-1 cells was then investigated using the MTT method, apoptosis was detected by flow cytometry, and the ERS markers were detected by Western blot.. The blood glucose, lipids, insulin, and TNF-α were significantly elevated in the T2DM model. A gradual recovery was observed in the DJB group. GLP-1 expression in the distal ileum of the DJB group was significantly higher than that in the T2DM control group (DM) and the SO group (p < 0.05), and the markers of ERS expression in the pancreases of the DJB group decreased significantly more than those of groups DM and SO (p < 0.05). Compared with group A, the cell viability in group B was decreased, and the ERS and apoptosis were increased (p < 0.05). However, compared with group B, the cell viability in group C was improved, and the ERS and apoptosis declined (p < 0.05).. DJB can be used to treat T2DM in T2DM rats. The mechanism may be that the DJB stimulates the increased expression of GLP-1 on the far side of the ileum, and then, GLP-1 inhibits ERS in the pancreas, reducing the apoptosis of β cells to create a treatment effect in the T2DM rats. Topics: Animals; Blood Glucose; Diabetes Mellitus, Type 2; Duodenum; Gastric Bypass; Glucagon-Like Peptide 1; Humans; Jejunum; Rats | 2022 |
Implications of ligand-receptor binding kinetics on GLP-1R signalling.
Topics: Diabetes Mellitus, Type 2; Glucagon-Like Peptide 1; Glucagon-Like Peptide-1 Receptor; Humans; Kinetics; Ligands; Peptides; Receptors, G-Protein-Coupled | 2022 |
Correlates of Glucagon-Like Peptide-1 Receptor Agonist Use Among Patients With Atherosclerotic Cardiovascular Disease and Type 2 Diabetes Mellitus (from the Department of Veterans Affairs).
This study used data from the Veterans Affairs administrative and clinical dataset to evaluate determinants of glucagon-like peptide-1 receptor agonist (GLP-1 RA) use among patients with concomitant atherosclerotic cardiovascular disease and diabetes mellitus and an antecedent primary care provider visit. The prevalence of GLP-1 RA use was 8.0%. In multivariable-adjusted models, White race, hypertension, obesity, higher hemoglobin A1c, ischemic heart disease, chronic kidney disease, a higher number of primary care provider visits, and previous cardiology or endocrinology visits were directly associated with GLP-1 RA use. Older age, having a physician primary care provider, and receiving care at a teaching facility were inversely associated with GLP-1 RA use. Our data can help inform targeted interventions to promote equitable access to GLP-1 RA and incentivize the adoption of these disease-modifying agents in high-risk patient populations. Topics: Atherosclerosis; Cardiovascular Diseases; Diabetes Mellitus, Type 2; Glucagon-Like Peptide 1; Glucagon-Like Peptide-1 Receptor; Humans; Hypoglycemic Agents; Veterans | 2022 |
Diabetes, antidiabetic medications and risk of depression - A population-based cohort and nested case-control study.
Diabetes type 2 is associated with depression, but the impact of antidiabetic drugs is not clear. The objective was to analyze the association between diabetes type 2, antidiabetic drugs, and depression.. This register-based study included 116.699 patients with diabetes type 2 diagnosed from 2000 to 2012 and an age, gender, and municipality matched reference group of 116.008 individuals without diabetes. All participants were followed for a diagnosis of depression or prescription of antidepressant medication. Based on this, a case-control study was nested within the cohort, using risk set sampling. Antidiabetic medication was categorized into insulin, metformin, sulfonylureas and glinides combined, glitazones, dipeptidyl peptidase 4 (DPP4) inhibitors, glucagon-like peptide 1 (GLP1) analogs, sodium-glucose transport protein 2 (SGLT2) inhibitors and acarbose. The association between diabetes and depression was analyzed using Cox proportional hazards regression, whereas conditional logistic regression was used to analyze the association between use of antidiabetic drugs and depression.. Patients with diabetes had higher risk of depression compared to individuals without diabetes (hazard ratio 1.14 (95% confidence interval 1.14-1.15)). Low doses of metformin, DPP4 inhibitors, GLP1 analogs, and SGLT2 inhibitors were associated with lower risk of depression in patients with diabetes compared to non-users, with the lowest risk for sodium-glucose transport protein 2 inhibitor users (odds ratio 0.55 (0.44-0.70)). Use of insulin, sulfonylurea and high doses of metformin were associated with higher risk of depression.. Patients with diabetes had increased risk of depression. However, users of specific antidiabetic drugs had lower risk of depression compared to non-users. Topics: Case-Control Studies; Depression; Diabetes Mellitus, Type 2; Dipeptidyl-Peptidase IV Inhibitors; Glucagon-Like Peptide 1; Humans; Hypoglycemic Agents; Insulin; Metformin | 2022 |
The Role of Glucagon-Like Peptide 1 (GLP-1) Receptor Agonists in the Prevention and Treatment of Diabetic Kidney Disease: Insights from the AMPLITUDE-O Trial.
Topics: Clinical Trials as Topic; Diabetes Mellitus, Type 2; Diabetic Nephropathies; Glucagon-Like Peptide 1; Glucagon-Like Peptide-1 Receptor; Humans; Hypoglycemic Agents | 2022 |
Impact on Glucose Homeostasis: Is Food Biofortified with Molybdenum a Workable Solution? A Two-Arm Study.
Diabetes is expected to increase up to 700 million people worldwide with type 2 diabetes being the most frequent. The use of nutritional interventions is one of the most natural approaches for managing the disease. Minerals are of paramount importance in order to preserve and obtain good health and among them molybdenum is an essential component. There are no studies about the consumption of biofortified food with molybdenum on glucose homeostasis but recent studies in humans suggest that molybdenum could exert hypoglycemic effects. The present study aims to assess if consumption of lettuce biofortified with molybdenum influences glucose homeostasis and whether the effects would be due to changes in gastrointestinal hormone levels and specifically Peptide YY (PYY), Glucagon-Like Peptide 1 (GLP-1), Glucagon-Like Peptide 2 (GLP-2), and Gastric Inhibitory Polypeptide (GIP). A cohort of 24 people was supplemented with biofortified lettuce for 12 days. Blood and urine samples were obtained at baseline (T0) and after 12 days (T2) of supplementation. Blood was analyzed for glucose, insulin, insulin resistance, β-cell function, and insulin sensitivity, PYY, GLP-1, GLP-2 and GIP. Urine samples were tested for molybdenum concentration. The results showed that consumption of lettuce biofortified with molybdenum for 12 days did not affect beta cell function but significantly reduced fasting glucose, insulin, insulin resistance and increased insulin sensitivity in healthy people. Consumption of biofortified lettuce did not show any modification in urine concentration of molybdenum among the groups. These data suggest that consumption of lettuce biofortified with molybdenum improves glucose homeostasis and PYY and GIP are involved in the action mechanism. Topics: Blood Glucose; Diabetes Mellitus, Type 2; Food, Fortified; Gastric Inhibitory Polypeptide; Glucagon-Like Peptide 1; Glucagon-Like Peptide 2; Glucose; Homeostasis; Humans; Insulin; Insulin Resistance; Lactuca; Molybdenum; Peptide YY | 2022 |
Enhancement of DPP-IV inhibitory activity and the capacity for enabling GLP-1 secretion through RADA16-assisted molecular designed rapeseed peptide nanogels.
The potential of pentapeptide IPQVS (RAP1) and octapeptide ELHQEEPL (RAP2) derived from rapeseed napin as natural dipeptidyl-peptidase IV (DPP-IV) inhibitors is promising. The objective was to develop a nanogel strategy to resist the hydrolysis of digestive and intestinal enzymes to enhance the DPP-IV inhibitory activity of RAP1 and RAP2, and stimulate glucagon-like peptide 1 (GLP-1) secretion of RAP2 by a RADA16-assisted molecular design. The linker of double Gly was used in the connection of RADA16 and the functional oligopeptide region (RAP1 and RAP2). Compared to the original oligopeptides, DPP-IV IC Topics: Brassica napus; Brassica rapa; Caco-2 Cells; Diabetes Mellitus, Type 2; Dipeptidyl Peptidase 4; Dipeptidyl-Peptidase IV Inhibitors; Glucagon-Like Peptide 1; Humans; Nanogels; Peptides | 2022 |
GLP1-oestrogen agonist protects β-cells from insulin-deficient diabetes mellitus.
Topics: Diabetes Mellitus, Type 2; Estrogens; Glucagon-Like Peptide 1; Humans; Insulin; Insulin-Secreting Cells | 2022 |
Pharmacological profile of once-weekly injectable semaglutide for chronic weight management.
The recent approval in the USA (Food and Drug Administration), Canada (Health Canada), UK (Medicines and Healthcare products Regulatory Agency), and EU (European Medicines Agency) of once-weekly injectable semaglutide 2.4 mg, as an adjunct to a calorie-controlled diet and increased physical activity, for chronic weight management provides health-care practitioners with an additional option when prescribing weight-loss medication.. We describe the chemistry, mechanism of action, and pharmacological properties of semaglutide (a glucagon-like peptide 1 receptor agonist [GLP-1 RA]) and discuss clinical data and considerations for using once-weekly subcutaneous semaglutide 2.4 mg as treatment for overweight and obesity among patients with and without type 2 diabetes (T2D).. Once-weekly subcutaneous semaglutide 2.4 mg is the most efficacious medication approved for chronic weight management among patients with overweight and obesity, with and without T2D, and is the first drug to induce sustained double-digit reductions in percentage body weight over 1- to 2-year treatment periods. It demonstrates a similar safety and tolerability profile to other GLP-1 RAs. Semaglutide 2.4 mg treatment could dramatically improve clinical approaches to weight management, but the relatively high cost might prevent patients accessing treatment. Further research exploring the cost-effectiveness of subcutaneous semaglutide 2.4 mg is required. Topics: Diabetes Mellitus, Type 2; Glucagon-Like Peptide 1; Glucagon-Like Peptide-1 Receptor; Glucagon-Like Peptides; Humans; Hypoglycemic Agents; Obesity; Overweight; Pharmaceutical Preparations | 2022 |
Global use of SGLT2 inhibitors and GLP-1 receptor agonists in type 2 diabetes. Results from DISCOVER.
Despite strong evidence of benefit, uptake of newer glucose-lowering medications that reduce cardiovascular risk has been low. We sought to examine global trends and predictors of use of SGLT2i and GLP-1 RA in patients with type 2 diabetes.. DISCOVER is a global, prospective, observational study of patients with diabetes enrolled from 2014-16 at initiation of second-line glucose-lowering therapy and followed for 3 years. We used hierarchical logistic regression to examine factors associated with use of either an SGLT2i or GLP-1 RA at last follow-up and to assess country-level variability.. Among 14,576 patients from 37 countries, 1579 (10.8%) were started on an SGLT2i (1275; 8.7%) or GLP-1 RA (318; 2.2%) at enrollment, increasing to 16.1% at end of follow-up, with large variability across countries (range 0-62.7%). Use was highest in patients treated by cardiologists (26.1%) versus primary care physicians (10.4%), endocrinologists (16.9%), and other specialists (22.0%; p < 0.001). Coronary artery disease (OR 1.29, 95% CI 1.08-1.54) was associated with greater use of SGLT2i or GLP-1 RA while peripheral artery disease (OR 0.73, 95% CI 0.54-1.00) and chronic kidney disease (OR 0.73, 95% CI 0.58-0.94) were associated with lower use (OR 0.73, 95% CI 0.54-1.00). The country-level median odds ratio was 3.48, indicating a very large amount of variability in the use of SGLT2i or GLP-1 RA independent of patient demographic and clinical factors.. Global use of glucose-lowering medications with established cardiovascular benefits has increased over time but remains suboptimal, particularly in sub-groups most likely to benefit. Substantial country-level variability exists independent of patient factors, suggesting structural barriers may limit more widespread use of these medications. Topics: Diabetes Mellitus, Type 2; Glucagon-Like Peptide 1; Glucagon-Like Peptide-1 Receptor; Glucose; Humans; Hypoglycemic Agents; Prospective Studies; Sodium-Glucose Transporter 2 Inhibitors | 2022 |
Glucagonlike Peptide-1 Receptor Imaging in Individuals with Type 2 Diabetes.
Topics: Diabetes Mellitus, Type 2; Diagnostic Imaging; Glucagon-Like Peptide 1; Glucagon-Like Peptide-1 Receptor; Humans; Peptides | 2022 |
Acute concomitant glucose-dependent insulinotropic polypeptide receptor antagonism during glucagon-like peptide 1 receptor agonism does not affect appetite, resting energy expenditure or food intake in patients with type 2 diabetes and overweight/obesity.
Topics: Appetite; Diabetes Mellitus, Type 2; Eating; Energy Metabolism; Gastric Inhibitory Polypeptide; Glucagon-Like Peptide 1; Glucagon-Like Peptide-1 Receptor; Humans; Incretins; Obesity; Overweight; Receptors, Gastrointestinal Hormone | 2022 |
Real-world outcomes of addition of insulin glargine 300 U/mL (Gla-300) to glucagon-like peptide-1 receptor agonist (GLP-1 RA) therapy in people with type 2 diabetes: The DELIVER-G study.
To provide real-world data on the addition of basal insulin (BI) in people with type 2 diabetes mellitus (PWD2) suboptimally controlled with glucagon-like peptide-1 receptor agonist (GLP-1RA) therapy. However, real-world data on the addition of BI to GLP-1RA therapy are limited.. We used a US electronic medical record data source (IBM® Explorys®) that includes approximately 4 million PWD2 to assess the real-world impact of adding the second-generation BI analogue insulin glargine 300 U/mL (Gla-300) to GLP-1RA therapy. Insulin-naïve PWD2 receiving GLP-1RAs who also received Gla-300 between March 1, 2015 and September 30, 2019 were identified; participants were required to have data for ≥12 months before, and ≥6 months after, addition of Gla-300.. The mean (standard deviation [SD]) age of participants (N = 271) was 57.9 (10.8) years. Baseline glycated haemoglobin (HbA1c) was 9.16% and was significantly reduced (-0.97 [SD 1.60]%; P < 0.0001) after addition of Gla-300; a significant increase in the proportion of PWD2 achieving HbA1c control was observed after addition of Gla-300 (HbA1c <7.0%: 4.80% vs. 22.14%, P < 0.0001; HbA1c <8.0%: 19.56% vs. 51.29%, P < 0.0001). The incidence of overall (8.49% vs. 9.59%; P = 0.513) and inpatient/emergency department (ED)-associated hypoglycaemia (0.37% vs. 0.74%; P = 1.000), as well as overall (0.33 vs. 0.46 per person per year [PPPY]; P = 0.170) and inpatient/ED-associated hypoglycaemia events (0.01 vs. 0.04 PPPY; P = 0.466) were similar before and after addition of Gla-300.. In US real-world clinical practice, adding Gla-300 to GLP-1RA significantly improved glycaemic control without significantly increasing hypoglycaemia in PWD2. Further research into the effect of adding Gla-300 to GLP-1RA therapy is warranted. Topics: Diabetes Mellitus, Type 2; Glucagon-Like Peptide 1; Glucagon-Like Peptide-1 Receptor; Glycated Hemoglobin; Humans; Hypoglycemia; Hypoglycemic Agents; Insulin; Insulin Glargine; Middle Aged | 2022 |
Healthcare costs and hospitalizations in US patients with type 2 diabetes and cardiovascular disease: A retrospective database study (OFFSET).
To investigate the budget implications of treatment with glucagon-like peptide-1 receptor agonists (GLP-1 RAs) versus other glucose-lowering treatment (here termed 'standard of care' [SoC]) during 2012-2019.. GLP-1 RA-naïve adults with type 2 diabetes (T2D) in the IBM MarketScan database with at least one glucose-lowering medication claim within 6 months after their first cardiovascular disease (CVD) hospitalization were included (index date was the date of first claim for a GLP-1 RA for the GLP-1 RA group, and the date of the first claim, independent of medication type, for the SoC group). Monthly healthcare costs and hospitalization risk over 12 months postindex date were compared for those who initiated a GLP-1 RA posthospitalization versus those with a claim for any other glucose-lowering medication.. Postindex date, mean observed total costs were lower for patients receiving a GLP-1 RA compared with SoC ($3853 vs. $4288). In adjusted analysis, both groups had similar total healthcare costs (P = .56). This was driven by significantly lower inpatient and outpatient costs and higher drug costs in the GLP-1 RA group compared with SoC (P < .001). Risks of all-cause (adjusted hazard ratio: 0.85) and CVD-related hospitalization (0.76) were significantly lower in the GLP-1 RA group compared with SoC (P < .001). Similar results were observed in a subgroup with atherosclerotic CVD.. These findings suggest that, in US patients with T2D and a CVD-related hospitalization, the added medical cost of treatment with GLP-1 RAs is offset by lower inpatient and outpatient care costs, resulting in budget neutrality against SoC. Topics: Adult; Cardiovascular Diseases; Diabetes Mellitus, Type 2; Glucagon-Like Peptide 1; Glucagon-Like Peptide-1 Receptor; Glucose; Health Care Costs; Hospitalization; Humans; Hypoglycemic Agents; Retrospective Studies | 2022 |
Association between different diabetes medication classes and risk of Parkinson's disease in people with diabetes.
Diabetes has been associated with increased risk of Parkinson's disease (PD). Diabetes medications have been suggested as a possible explanation, but findings have been inconsistent. More information on the role of exposure in different time windows is needed because PD has long onset. We assessed the association between use of different diabetes medication categories and risk of PD in different exposure periods.. A case-control study restricted to people with diabetes was performed as part of nationwide register-based Finnish study on PD (FINPARK). We included 2017 cases (diagnosed 1999-2015) with PD and 7934 controls without PD. Diabetes medication use was identified from Prescription Register (1995-2015) and categorized to insulins, biguanides, sulfonylureas, thiazolidinediones (TZDs), dipeptidyl peptidase 4 (DPP-4) inhibitors, glucagon-like peptide-1 (GLP-1) analogues and glinide. Exposure for each medication class was determined as none, at least 3 years before outcome and only within the three-year lag time before PD outcome.. The use of insulins, biguanides, sulfonylureas, DPP-4 inhibitors, GLP-1 analogues or glinides was not associated with PD. Use of TZDs before lag time compared to non-use of TZDs (adjusted odds ratio (OR) 0.78; 95% Confidence interval (CI) 0.64-0.95) was associated with decreased risk of PD.. Our nationwide case-control study of people with diabetes found no robust evidence on the association between specific diabetes medication classes and risk of PD. Consistent with earlier studies, TZD use was associated with slightly decreased risk of PD. The mechanism for this should be verified in further studies. Topics: Biguanides; Case-Control Studies; Diabetes Mellitus, Type 2; Dipeptidyl-Peptidase IV Inhibitors; Glucagon-Like Peptide 1; Humans; Hypoglycemic Agents; Insulin; Parkinson Disease; Sulfonylurea Compounds; Thiazolidinediones | 2022 |
Sodium-Glucose Cotransporter-2 Inhibitors and Urinary Tract Infections: A Propensity Score-matched Population-based Cohort Study.
Sodium-glucose cotransporter-2 (SGLT2) inhibitor-induced glycosuria is hypothesized to increase the risk of urinary tract infections (UTIs). We assessed the risk of UTIs associated with SGLT2 inhibitor initiation in type 2 diabetes.. We conducted a population-based cohort study using primary care data from the United Kingdom's Clinical Practice Research Datalink (CPRD) and administrative health-care data from Alberta, Canada. From a base cohort of new metformin users, we constructed 5 comparative cohorts, wherein the exposure contrast was defined as new use of SGLT2 inhibitors or 1 of 5 active comparators: dipeptidylpeptidase-4 (DPP-4) inhibitors, sulfonylureas (SU), glucagon-like peptide-1 receptor agonists (GLP-1 RA), thiazolidinediones (TZD) and insulin. We defined a composite UTI outcome based on hospitalizations or physician visit records. For each comparative cohort, we used high-dimensional propensity score matching to adjust for confounding and Cox proportional hazards regression to estimate the hazard ratios (HRs) in each database. We meta-analyzed estimates using a random-effects model.. SGLT2 inhibitor use was not associated with a higher risk of UTI compared with DPP-4 inhibitors (pooled HR, 1.08; 95% confidence interval [CI], 0.89 to 1.30), SU (pooled HR, 1.08; 95% CI, 0.90 to 1.30), GLP-1 RA (pooled HR, 0.81; 95% CI, 0.61 to 1.09) or TZD (pooled HR, 0.81; 95% CI, 0.55 to 1.19). The risk of UTI was lower compared with insulin (pooled HR, 0.74; 95% CI, 0.63 to 0.87). The risk of UTI did not differ based on the SGLT2 inhibitor agent or dose. Last, SGLT2 inhibitor initiation was not associated with an increased risk of UTI recurrence.. SGLT2 inhibitor use is not associated with an increased risk of UTIs, compared with other antidiabetic agents. Topics: Alberta; Cohort Studies; Diabetes Mellitus, Type 2; Dipeptidyl-Peptidase IV Inhibitors; Glucagon-Like Peptide 1; Glucose; Humans; Hypoglycemic Agents; Insulin; Propensity Score; Sodium; Sodium-Glucose Transporter 2 Inhibitors; Sulfonylurea Compounds; Thiazolidinediones; Urinary Tract Infections | 2022 |
Incretin Response to Mixed Meal Challenge in Active Cushing's Disease and after Pasireotide Therapy.
Cushing’s disease (CD) causes diabetes mellitus (DM) through different mechanisms in a significant proportion of patients. Glucose metabolism has rarely been assessed with appropriate testing in CD; we aimed to evaluate hormonal response to a mixed meal tolerance test (MMTT) in CD patients and analyzed the effect of pasireotide (PAS) on glucose homeostasis. To assess gastro-entero-pancreatic hormones response in diabetic (DM+) and non-diabetic (DM−) patients, 26 patients with CD underwent an MMTT. Ten patients were submitted to a second MMTT after two months of PAS 600 µg twice daily. The DM+ group had significantly higher BMI, waist circumference, glycemia, HbA1c, ACTH levels and insulin resistance indexes than DM− (p < 0.05). Moreover, DM+ patients exhibited increased C-peptide (p = 0.004) and glucose area under the curve (AUC) (p = 0.021) during MMTT, with a blunted insulinotropic peptide (GIP) response (p = 0.035). Glucagon levels were similar in both groups, showing a quick rise after meals. No difference in estimated insulin secretion and insulin:glucagon ratio was found. After two months, PAS induced an increase in both fasting glycemia and HbA1c compared to baseline (p < 0.05). However, this glucose trend after meal did not worsen despite the blunted insulin and C-peptide response to MMTT. After PAS treatment, patients exhibited reduced insulin secretion (p = 0.005) and resistance (p = 0.007) indexes. Conversely, glucagon did not change with a consequent impairment of insulin:glucagon ratio (p = 0.009). No significant differences were observed in incretins basal and meal-induced levels. Insulin resistance confirmed its pivotal role in glucocorticoid-induced DM. A blunted GIP response to MMTT in the DM+ group might suggest a potential inhibitory role of hypercortisolism on enteropancreatic axis. As expected, PAS reduced insulin secretion but also induced an improvement in insulin sensitivity as a result of cortisol reduction. No differences in incretin response to MMTT were recorded during PAS therapy. The discrepancy between insulin and glucagon trends while on PAS may be an important pathophysiological mechanism in this iatrogenic DM; hence restoring insulin:glucagon ratio by either enhancing insulin secretion or reducing glucagon tone can be a potential therapeutic target. Topics: Blood Glucose; C-Peptide; Diabetes Mellitus; Diabetes Mellitus, Type 2; Gastric Inhibitory Polypeptide; Glucagon; Glucagon-Like Peptide 1; Glycated Hemoglobin; Humans; Incretins; Insulin; Insulin Resistance; Meals; Pituitary ACTH Hypersecretion; Somatostatin | 2022 |
Cardiovascular protection conferred by glucagon-like peptide-1 receptor agonists: A role for serum uric acid reduction?
Topics: Cardiovascular Diseases; Cardiovascular System; Diabetes Mellitus, Type 2; Glucagon-Like Peptide 1; Glucagon-Like Peptide-1 Receptor; Humans; Hypoglycemic Agents; Uric Acid | 2022 |
Serum uric acid lowering mediated by glucagon-like peptide-1 receptor agonists: Emerging considerations.
Topics: Diabetes Mellitus, Type 2; Glucagon-Like Peptide 1; Glucagon-Like Peptide-1 Receptor; Humans; Hypoglycemic Agents; Uric Acid | 2022 |
Discovery of once-weekly, peptide-based selective GLP-1 and cholecystokinin 2 receptors co-agonizts.
A group of long-acting, peptide-based, and selective GLP-1R/CCK-2R dual agonizts were identified by rational design. Guided by sequence analysis, structural elements of the CCK-2R agonist moiety were engineered into the GLP-1R agonist Xenopus GLP-1, resulting in hybrid peptides with potent GLP-1R/CCK-2R dual activity. Further modifications with fatty acids resulted in novel metabolically stable peptides, among which 3d and 3 h showed potent GLP-1R and CCK-2R activation potencies and comparable stability to semaglutide. In food intake tests, 3d and 3 h also showed a potent reduction in food intake, superior to that of semaglutide. Moreover, the acute hypoglycemic and insulinotropic activities of 3d and 3 h were better than that of semaglutide and ZP3022. Importantly, the limited pica response following 3d and 3 h administration in SD rats preliminarily indicated that the food intake reduction effects of 3d and 3 h are independent of nausea/vomiting. In a 35-day study in db/db mice, every two days administration of 3d and 3 h increased islet areas and numbers, insulin contents, β-cell area, β-cell proliferation, as well as improved glucose tolerance, and decreased HbA1c, to a greater extent than ZP3022 and semaglutide. In a 21-day study in DIO mice, once-weekly administration of 3d and 3 h significantly induced body weight loss, improved glucose tolerance, and normalized lipid metabolism, to a greater extent than semaglutide. The current study showed the antidiabetic and antiobesity potentials of GLP-1R/CCK-2R dual agonizts that warrant further investigation. Topics: Animals; Anti-Obesity Agents; Cholecystokinin; Diabetes Mellitus, Type 2; Glucagon-Like Peptide 1; Glucagon-Like Peptide-1 Receptor; Glucose; Hypoglycemic Agents; Mice; Peptides; Rats; Rats, Sprague-Dawley; Receptor, Cholecystokinin B | 2022 |
Glucose- and Bile Acid-Stimulated Secretion of Gut Hormones in the Isolated Perfused Intestine Is Not Impaired in Diet-Induced Obese Mice.
Decreased circulating levels of food-intake-regulating gut hormones have been observed in type 2 diabetes and obesity. However, it is still unknown if this is due to decreased secretion from the gut mucosal cells or due to extra-intestinal processing of hormones.. We measured intestinal hormone content and assessed morphological differences in the intestinal mucosa by histology and immunohistochemistry. Secretion of hormones and absorption of glucose and bile acids (BA) were assessed in isolated perfused mouse intestine.. GIP (glucose-dependent insulinotropic polypeptide) and SS (somatostatin) contents were higher in the duodenum of control mice (p < 0.001, and <0.01). Duodenal GLP-1 (glucagon-like peptide-1) content (p < 0.01) and distal ileum PYY content were higher in DIO mice (p < 0.05). Villus height in the jejunum, crypt depth, and villus height in the ileum were increased in DIO mice (p < 0.05 and p = 0.001). In the distal ileum of DIO mice, more immunoreactive GLP-1 and PYY cells were observed (p = 0.01 and 0.007). There was no difference in the absorption of glucose and bile acids. Distal secretion of SS tended to be higher in DIO mice (p < 0.058), whereas no difference was observed for the other hormones in response to glucose or bile acids.. Our data suggest that differences regarding production and secretion are unlikely to be responsible for the altered circulating gut hormone levels in obesity, since enteroendocrine morphology and hormone secretion capacity were largely unaffected in DIO mice. Topics: Animals; Bile Acids and Salts; Diabetes Mellitus, Type 2; Diet; Gastrointestinal Hormones; Glucagon-Like Peptide 1; Glucose; Intestinal Mucosa; Mice; Mice, Obese; Obesity | 2022 |
Relationships of Glucose, GLP-1, and Insulin Secretion With Gastric Emptying After a 75-g Glucose Load in Type 2 Diabetes.
The relationships of gastric emptying (GE) with the glycemic response at 120 minutes, glucagon-like peptide-1 (GLP-1), and insulin secretion following a glucose load in type 2 diabetes (T2D) are uncertain.. We evaluated the relationship of plasma glucose, GLP-1, and insulin secretion with GE of a 75-g oral glucose load in T2D.. Single-center, cross-sectional, post hoc analysis.. Institutional research center.. 43 individuals with T2D age 65.6 ± 1.1 years, hemoglobin A1c 7.2 ± 1.0%, median duration of diabetes 5 years managed by diet and/or metformin.. Participants consumed the glucose drink radiolabeled with 99mTc-phytate colloid following an overnight fast. GE (scintigraphy), plasma glucose, GLP-1, insulin, and C-peptide were measured between 0 and 180 minutes.. The relationships of the plasma glucose at 120 minutes, plasma GLP-1, and insulin secretion (calculated by Δinsulin0-30/ Δglucose0-30 and ΔC-peptide0-30/Δglucose0-30) with the rate of GE (scintigraphy) were evaluated.. There were positive relationships of plasma glucose at 30 minutes (r = 0.56, P < 0.001), 60 minutes (r = 0.57, P < 0.001), and 120 minutes (r = 0.51, P < 0.001) but not at 180 minutes (r = 0.13, P = 0.38), with GE. The 120-minute plasma glucose and GE correlated weakly in multiple regression models adjusting for age, GLP-1, and insulin secretion (P = 0.04 and P = 0.06, respectively). There was no relationship of plasma GLP-1 with GE. Multiple linear regression analysis indicated that there was no significant effect of GE on insulin secretion.. In T2D, while insulin secretion is the dominant determinant of the 120-minute plasma glucose, GE also correlates. Given the relevance to interpreting the results of an oral glucose tolerance test, this relationship should be evaluated further. There appears to be no direct effect of GE on either GLP-1 or insulin secretion. Topics: Aged; Blood Glucose; Cross-Sectional Studies; Diabetes Mellitus, Type 2; Gastric Emptying; Glucagon-Like Peptide 1; Glucose; Humans; Insulin; Insulin Secretion; Middle Aged | 2022 |
Response of blood glucose and GLP-1 to different food temperature in normal subject and patients with type 2 diabetes.
Eating behavior is a major factor in type 2 diabetes. We investigated the different responses of glucose-regulating hormones to cold and hot glucose solutions in normal subjects and patients with type 2 diabetes.. In this crossover, self-controlled study, normal subjects (N = 19) and patients with type 2 diabetes (N = 22) were recruited and randomly assigned to a hot (50 °C) or a cold (8 °C) oral glucose-tolerance test (OGTT). The subsequent day, they were switched to the OGTT at the other temperature. Blood glucose, insulin, GIP, glucagon-like peptide-1 (GLP-1), and cortisol were measured at 0, 5, 10, 30, 60, and 120 min during each OGTT. After the hot OGTT, all subjects ingested hot (>42 °C) food and water for that day, and ingested food and water at room temperature (≤24 °C) for the day after cold OGTT. All participants had continuous glucose monitoring (CGM) throughout the study.. Compared to cold OGTT, blood glucose was significantly higher with hot OGTT in both groups (both P < 0.05). However, insulin and GLP-1 levels were significantly higher in hot OGTT in normal subjects only (both P < 0.05). The GIP and cortisol responses did not differ with temperature in both groups. CGM showed that normal subjects had significantly higher 24-h mean glucose (MBG) (6.11 ± 0.13 vs. 5.84 ± 0.11 mmol/L, P = 0.021), and standard deviation of MBG with hot meals (0.59 ± 0.06 vs. 0.48 ± 0.05 mmol/L, P = 0.043), T2DM patients had higher MBG only (8.46 ± 0.38 vs. 8.88 ± 0.39 mmol/L, P = 0.022).. Food temperature is an important factor in glucose absorption and GLP-1 response. These food temperatures elicited differences are lost in type 2 diabetes. Topics: Blood Glucose; Blood Glucose Self-Monitoring; Diabetes Mellitus, Type 2; Gastric Inhibitory Polypeptide; Glucagon-Like Peptide 1; Glucose; Humans; Hydrocortisone; Insulin; Temperature; Water | 2022 |
Glucagon-like peptide-1 receptor agonists as anti-inflammatory agents: A potential mode of cardiovascular benefits.
Topics: Anti-Inflammatory Agents; Cardiovascular Diseases; Diabetes Mellitus, Type 2; Glucagon-Like Peptide 1; Glucagon-Like Peptide-1 Receptor; Humans; Hypoglycemic Agents | 2022 |
Glucagon-like peptide-1 effect on β-cell function varies according to diabetes remission status after Roux-en-Y gastric bypass.
The contribution of endogenous glucagon-like peptide (GLP)-1 to β-cell function after Roux-en-Y gastric bypass surgery (RYGB) is well established in normoglycaemic individuals, but not in those with postoperative hyperglycaemia. We, therefore, studied the effect of GLP-1 on β-cell function in individuals with varying degrees of type 2 diabetes mellitus (T2D) control after RYGB.. EX9 blunted the increase in β-cell glucose sensitivity at 3 months (-44.1%, p < .001) and 12 months (-43.3%, p < .001), but not at 24 months (-12.4%, p = .243). EX9 enhanced postprandial glucagon concentrations by 62.0% at 3 months (p = .008), 46.5% at 12 months (p = .055), and 30.4% at 24 months (p = .017). EX9 counterintuitively decreased glucose concentrations at 3 months in the entire cohort (p < .001) but had no effect on glycaemia at 12 and 24 months in persistent T2D and impaired glucose tolerance; it minimally worsened glycaemia in REM at 12 months.. GLP-1 blockade reversed the improvement in β-cell function observed after RYGB, but this effect varied temporally and by REM status. GLP-1 blockade transiently and minimally worsened glycaemia only in REM, and lowered postprandial glucose values at 3 months, regardless of REM status. Topics: Blood Glucose; Diabetes Mellitus, Type 2; Gastric Bypass; Glucagon; Glucagon-Like Peptide 1; Glucagon-Like Peptide-1 Receptor; Glucose; Glucose Intolerance; Humans; Insulin; Retrospective Studies | 2022 |
GLP-1 receptor nitration contributes to loss of brain pericyte function in a mouse model of diabetes.
We have previously shown that diabetes causes pericyte dysfunction, leading to loss of vascular integrity and vascular cognitive impairment and dementia (VCID). Glucagon-like peptide-1 (GLP-1) receptor agonists (GLP-1 RAs), used in managing type 2 diabetes mellitus, improve the cognitive function of diabetic individuals beyond glycaemic control, yet the mechanism is not fully understood. In the present study, we hypothesise that GLP-1 RAs improve VCID by preventing diabetes-induced pericyte dysfunction.. Mice with streptozotocin-induced diabetes and non-diabetic control mice received either saline (NaCl 154 mmol/l) or exendin-4, a GLP-1 RA, through an osmotic pump over 28 days. Vascular integrity was assessed by measuring cerebrovascular neovascularisation indices (vascular density, tortuosity and branching density). Cognitive function was evaluated with Barnes maze and Morris water maze. Human brain microvascular pericytes (HBMPCs), were grown in high glucose (25 mmol/l) and sodium palmitate (200 μmol/l) to mimic diabetic conditions. HBMPCs were treated with/without exendin-4 and assessed for nitrative and oxidative stress, and angiogenic and blood-brain barrier functions.. Diabetic mice treated with exendin-4 showed a significant reduction in all cerebral pathological neovascularisation indices and an improved blood-brain barrier (p<0.05). The vascular protective effects were accompanied by significant improvement in the learning and memory functions of diabetic mice compared with control mice (p<0.05). Our results showed that HBMPCs expressed the GLP-1 receptor. Diabetes increased GLP-1 receptor expression and receptor nitration in HBMPCs. Stimulation of HBMPCs with exendin-4 under diabetic conditions decreased diabetes-induced vascular inflammation and oxidative stress, and restored pericyte function (p<0.05).. This study provides novel evidence that brain pericytes express the GLP-1 receptor, which is nitrated under diabetic conditions. GLP-1 receptor activation improves brain pericyte function resulting in restoration of vascular integrity and BBB functions in diabetes. Furthermore, the GLP-1 RA exendin-4 alleviates diabetes-induced cognitive impairment in mice. Restoration of pericyte function in diabetes represents a novel therapeutic target for diabetes-induced cerebrovascular microangiopathy and VCID. Topics: Animals; Brain; Diabetes Mellitus, Experimental; Diabetes Mellitus, Type 2; Disease Models, Animal; Exenatide; Glucagon-Like Peptide 1; Glucagon-Like Peptide-1 Receptor; Humans; Mice; Pericytes | 2022 |
Persistent disparities in diabetes medication receipt by socio-economic disadvantage in Australia.
It is unknown how use of newer glucose-lowering drugs (GLDs) has changed in Australia following the publication of clinical trials demonstrating definitive clinical advantages for glucagon-like peptide-1 receptor agonists (GLP-1 RAs) and sodium-glucose co-transporter 2 inhibitors (SGLT2is), and whether this varies by socio-economic disadvantage.. We included 1,064,645 people with type 2 diabetes registered on the National Diabetes Services Scheme. This cohort was linked to the Pharmaceutical Benefits Scheme database to evaluate trends in diabetes medication receipt and variation by socio-economic disadvantage between 2013 and 2019.. The proportion of people with type 2 diabetes receiving ≥3 GLDs concurrently increased from 12% in 2013 to 25% in 2019. By 2019, 6% of people with diabetes were receiving a GLP-1 RA and 21% an SGLT2i. Disparities in receipt of GLP-1 RAs and SGLT2is by socio-economic disadvantage decreased over time (ORs for most vs. least disadvantaged quintile were 0.80 [0.77-0.85] and 0.87 [0.82-0.94] in 2014 and 0.95 [0.92-0.98] and 1.07 [1.05-1.09] in 2019 for GLP-1 RAs and SGLT2is, respectively). However, people in more disadvantaged areas were more likely to receive multiple GLDs. After stratifying by number of concurrent GLDs received, people in more disadvantaged areas were less likely to receive GLP-1 RAs and SGLT2is in 2019 (ORs for most vs. least disadvantaged: 0.81 [0.78-0.84] and 0.90 [0.87-0.93] for people receiving ≥3 GLDs, respectively).. After controlling for intensity of glucose-lowering therapy, people in more disadvantaged areas were less likely to receive cardioprotective GLDs, although disparities decreased over time. Topics: Australia; Diabetes Mellitus, Type 2; Glucagon-Like Peptide 1; Glucagon-Like Peptide-1 Receptor; Glucose; Humans; Hypoglycemic Agents; Socioeconomic Factors; Sodium-Glucose Transporter 2 Inhibitors | 2022 |
Design and Development of a New Glucagon-Like Peptide-1 Receptor Agonist to Obtain High Oral Bioavailability.
Semaglutide is the only oral GLP-1 RA in the market, but oral bioavailability is generally limited in range of 0.4-1%. In this study, a new GLP-1RA named SHR-2042 was developed to gain higher oral bioavailability than semaglutide.. Self-association of SHR-2042, semaglutide and liraglutide were assessed using SEC-MALS. The intestinal perfusion test in SD rats was used to select permeation enhancers (PEs) including SNAC, C10 and LCC. ITC, CD and DLS were used to explore the interaction between SHR-2042 and SNAC. Gastric administrated test in SD rats was used to screen SHR-2042 granules with different SHR-2042/SNAC ratios. The oral bioavailability of SHR-2042 was studied in rats and monkeys.. The designed GLP-1RA, SHR-2042, gives a better solubility and lipophilicity than semaglutide. While it forms a similar oligomer with that of semaglutide. During the selection of PEs, SNAC shows better exposure than the other competing PEs including C10 and LCC. SHR-2042 and SNAC bind quickly and exhibit hydrophobic interaction. SNAC could promote monomerization of SHR-2042 and form micelles to trap the monomerized SHR-2042. The oral bioavailability of SHR-2042 paired with SNAC is 0.041% (1:0, w/w), 0.083% (1:10, w/w), 0.32% (1:30, w/w) and 2.83% (1:60, w/w) in rats. And the oral bioavailability of SHR-2042 matched with SNAC is 3.39% (1:30, w/w) in monkeys, which is over 10 times higher than that of semaglutide.. We believe that the design and development of oral SHR-2042 will provide a new way to design more and more GLP-1RAs with high oral bioavailability in the future. Topics: Animals; Biological Availability; Diabetes Mellitus, Type 2; Glucagon-Like Peptide 1; Glucagon-Like Peptide-1 Receptor; Hypoglycemic Agents; Rats; Rats, Inbred SHR; Rats, Sprague-Dawley | 2022 |
Glucagon-Like Peptide 1 Receptor Agonists (GLP1RA) and Sodium-glucose co-transporter-2 inhibitors (SGLT2i): Making a pragmatic choice in diabetes management.
The availability of newer glucose-lowering drugs has created opportunities for comprehensive diabetes care. Two classes of drugs, GLP1RA (glucagon-like peptide 1 receptor agonists), and SGLT2i (sodium glucose cotransporter 2 inhibitors) have demonstrated their efficacy in glucose control as well as cardiovascular risk reduction. While both can be used together, there is an ongoing debate regarding their relative advantages and limitations. We present a clinical perspective to compare and control these two classes of drugs, and promote rational prescription in diabetes praxis. Topics: Cardiovascular Diseases; Diabetes Mellitus, Type 2; Glucagon-Like Peptide 1; Glucagon-Like Peptide-1 Receptor; Glucose; Humans; Hypoglycemic Agents; Sodium; Sodium-Glucose Transporter 2 Inhibitors; Symporters | 2022 |
GZR18, a novel long-acting GLP-1 analog, demonstrated positive in vitro and in vivo pharmacokinetic and pharmacodynamic characteristics in animal models.
Topics: Animals; Blood Glucose; Body Weight; Diabetes Mellitus, Experimental; Diabetes Mellitus, Type 2; Glucagon-Like Peptide 1; Glucagon-Like Peptide-1 Receptor; Hypoglycemic Agents; Insulin; Mice; Mice, Inbred C57BL; Mice, Inbred Strains; Models, Animal; Rats; Rats, Sprague-Dawley | 2022 |
Exposure-Response Analysis of Cardiovascular Outcome Trials With Incretin-Based Therapies.
Our study aimed to evaluate the exposure-response relationship between incretin-based medications and the risk of major adverse cardiovascular events (MACE) using cardiovascular outcome trials (CVOTs). Eleven CVOTs with incretin-based medications were included. The median follow-up time, percentage of time exposure, and hazard ratio (HR) of MACE were obtained from each CVOT. The pharmacokinetic parameters of glucagon-like peptide-1 receptor agonists (GLP-1 RAs) and dipeptidyl peptidase-4 inhibitor (DPP-4) were obtained from published studies. Regression analysis was performed to assess the relationship between drug exposure and MACE HR. Cutoff values were determined from the ROC curves. The linear regression results indicated that log C Topics: Diabetes Mellitus, Type 2; Dipeptidyl-Peptidase IV Inhibitors; Glucagon-Like Peptide 1; Glucagon-Like Peptide-1 Receptor; Humans; Incretins | 2022 |
Association of GLP1R Polymorphisms With the Incretin Response.
Polymorphisms in the gene encoding the glucagon-like peptide-1 receptor (GLP1R) are associated with type 2 diabetes but their effects on incretin levels remain unclear.. We evaluated the physiologic and hormonal effects of GLP1R genotypes before and after interventions that influence glucose physiology.. Pharmacogenetic study conducted at 3 academic centers in Boston, Massachusetts.. A total of 868 antidiabetic drug-naïve participants with type 2 diabetes or at risk for developing diabetes.. We analyzed 5 variants within GLP1R (rs761387, rs10305423, rs10305441, rs742762, and rs10305492) and recorded biochemical data during a 5-mg glipizide challenge and a 75-g oral glucose tolerance test (OGTT) following 4 doses of metformin 500 mg over 2 days.. We used an additive mixed-effects model to evaluate the association of these variants with glucose, insulin, and incretin levels over multiple timepoints during the OGTT.. During the OGTT, the G-risk allele at rs761387 was associated with higher total GLP-1 (2.61 pmol/L; 95% CI, 1.0.72-4.50), active GLP-1 (2.61 pmol/L; 95% CI, 0.04-5.18), and a trend toward higher glucose (3.63; 95% CI, -0.16 to 7.42 mg/dL) per allele but was not associated with insulin. During the glipizide challenge, the G allele was associated with higher insulin levels per allele (2.01 IU/mL; 95% CI, 0.26-3.76). The other variants were not associated with any of the outcomes tested.. GLP1R variation is associated with differences in GLP-1 levels following an OGTT load despite no differences in insulin levels, highlighting altered incretin signaling as a potential mechanism by which GLP1R variation affects T2D risk. Topics: Blood Glucose; Diabetes Mellitus, Type 2; Glipizide; Glucagon-Like Peptide 1; Glucagon-Like Peptide-1 Receptor; Glucose; Humans; Incretins; Insulin | 2022 |
IMMUNOHISTOCHEMICAL DETECTION OF L CELLS IN GASTROINTESTINAL TRACT MUCOSA OF PATIENTS AFTER SURGICAL TREATMENT FOR CONTROL OF TYPE 2 DIABETES MELLITUS.
Type 2 diabetes mellitus (T2DM) is a disease of global impact that has led to an increase in comorbidities and mortality in several countries. Immunoexpression of the incretin hormones such as glucagon-like peptide-1 (GLP-1) and peptide YY (3-36) (PYY3-36) can be used as a scorer in the gastrointestinal tract to analyze L-cell activity in response to T2DM treatment. This study aimed to investigate the presence, location, and secretion of L cells in the small intestine of patients undergoing the form of bariatric surgery denominated adaptive gastroenteromentectomy with partial bipartition.. Immunohistochemical assays, quantitative real-time polymerase chain reaction (qPCR), and Western blot analysis were performed on samples of intestinal mucosa from patients with T2DM in both the preoperative and postoperative periods.. All results were consistent and indicated basal expression and secretion of GLP-1 and PYY3-36 incretins by L cells. A greater density of cells was demonstrated in the most distal portions of the small intestine. No significant difference was found between GLP-1 and PYY3-36 expression levels in the preoperative and postoperative periods because of prolonged fasting during which the samples were collected.. The greater number of L cells in activity implies better peptide signaling, response, and functioning of the neuroendocrine system. Topics: Animals; Diabetes Mellitus, Type 2; Gastrointestinal Tract; Glucagon-Like Peptide 1; Humans; Incretins; L Cells; Mice; Mucous Membrane | 2022 |
Low Use of Guideline-recommended Cardiorenal Protective Antihyperglycemic Agents in Primary Care: A Cross-sectional Study of Adults With Type 2 Diabetes.
Glucagon-like peptide-1 receptor agonists (GLP-1 RA) and sodium-glucose cotransporter-2 inhibitors (SGLT2i) have shown cardiorenal benefits independent of their glucose-lowering effects among persons living with type 2 diabetes mellitus (T2DM). In this study, we describe the proportion of persons with T2DM eligible to receive and currently receiving these agents based on their risk criteria for cardiorenal events.. This study was a cross-sectional analysis of primary care electronic medical records, in southern Alberta, of persons with T2DM who had at least 1 encounter with their primary care provider between December 31, 2018, to December 31, 2020. A descriptive and multivariate logistic regression analysis was conducted to examine clinical and demographic determinants of being prescribed one of the new treatments.. Our study sample included 11,939 persons living with T2DM, among whom 66.3% had a cardiorenal indication for SGLT2i or GLP-1 RA use. In the secondary and primary prevention subsamples, 19.4% and 16.6% of persons were prescribed SGLT2i or GLP-1 RA, respectively, compared with 20.0% of those with no specific cardiorenal indication. Several person-level characteristics, such as age (odds ratio [OR], 0.96; 95% confidence interval [CI], 0.96 to 0.97), male sex (OR, 1.37; 95% CI, 1.21 to 1.55) and glycated hemoglobin (OR, 1.29; 95% CI, 1.24 to 1.34), were associated with being prescribed SGLT2i or GLP-1 RA.. Low rates of SGLT2i or GLP-1 RA use and minimal differences between high-risk and no cardiorenal indication subsamples suggest the presence of barriers to prescribing these medications in a primary care setting. Action to highlight the indications for, and improve access to agents with, cardiorenal benefits will be required to achieve better outcomes for people with T2DM in primary care. Topics: Adult; Cross-Sectional Studies; Diabetes Mellitus, Type 2; Glucagon-Like Peptide 1; Glucose; Humans; Hypoglycemic Agents; Male; Primary Health Care; Sodium-Glucose Transporter 2 Inhibitors | 2022 |
Gut hormones and reproduction.
Reproduction and metabolism are intricately linked. Gut hormones play key roles in the regulation of body weight and glucose homeostasis, factors that influence the functioning of the hypothalamic-pituitary-gonadal axis and reproductive outcomes. Data from rodent models suggest gut hormones may have direct stimulatory effects on reproductive hormone release. However, the effects of gut hormones on reproductive function in humans are more complex, with possible involvement of direct (e.g. via gut hormone receptor agonism) as well as indirect (e.g. via weight reduction in people with obesity) mechanisms. The use of gut hormone receptor agonists has become an integral part of the management of metabolic diseases (including obesity and type 2 diabetes), with additional indications for their use on the horizon. Future work may identify specific roles for gut hormone receptor agonists in the treatment of reproductive co-morbidities that are increasingly being recognised in people with metabolic diseases. Topics: Diabetes Mellitus, Type 2; Gastrointestinal Hormones; Glucagon-Like Peptide 1; Humans; Obesity; Peptide YY; Reproduction | 2022 |
Are we there yet? Increasing use of cardioprotective antihyperglycemic agents in patients with T2D and CVD or CV risk in the United States.
To report on the use of antihyperglycemic agents (AHAs) by age (i.e. <65, ≥65 years) in patients with type 2 diabetes (T2D) and cardiovascular disease (CVD) or cardiovascular risk (CV risk) factors in the United States.. Patients with T2D and CVD (CVD cohort) or T2D and an additional CV risk factor without pre-existing CVD (CV risk cohort) were identified from 2015 to 2019 in a claims database. Patients were followed from their first observed CVD diagnosis or CV risk factor for each year they were continuously enrolled or until occurrence of a CVD diagnosis (CV risk cohort only). Classes of AHAs received were reported by year, cohort, and age group.. From 2015 to 2019, the percentage of patients <65 years on glucagon-like peptide-1 receptor agonists (GLP-1 RAs) increased (CVD: 9-17%, CV risk: 9-17%) and was approximately twice that of those ≥65 years (CVD: 4-8%, CV risk: 4-8%); the percentage of patients <65 years on sodium-glucose cotransporter-2 (SGLT2) inhibitors increased (CVD: 11-16%, CV risk: 11-17%) and was approximately triple that of those ≥65 years (CVD: 3-6%, CV risk: 4-7%).. The use of GLP-1 RAs and SGLT2 inhibitors increased during the study period; however, most patients did not receive these medications. Patients aged ≥65 years were particularly disadvantaged. Topics: Cardiotonic Agents; Cardiovascular Diseases; Diabetes Mellitus, Type 2; Glucagon-Like Peptide 1; Glucagon-Like Peptide-1 Receptor; Heart Disease Risk Factors; Humans; Hypoglycemic Agents; Risk Factors; United States | 2022 |
Development of a Primary Human Intestinal Epithelium Enriched in L-Cells for Assay of GLP-1 Secretion.
Type 2 diabetes mellitus is a chronic disease associated with obesity and dysregulated human feeding behavior. The hormone glucagon-like peptide 1 (GLP-1), a critical regulator of body weight, food intake, and blood glucose levels, is secreted by enteroendocrine L-cells. The paucity of L-cells in primary intestinal cell cultures including organoids and monolayers has made assays of GLP-1 secretion from primary human cells challenging. In the current paper, an analytical assay pipeline consisting of an optimized human intestinal tissue construct enriched in L-cells paired with standard antibody-based GLP-1 assays was developed to screen compounds for the development of pharmaceuticals to modulate L-cell signaling. The addition of the serotonin receptor agonist Bimu 8, optimization of R-spondin and Noggin concentrations, and utilization of vasoactive intestinal peptide (VIP) increased the density of L-cells in a primary human colonic epithelial monolayer. Additionally, the incorporation of an air-liquid interface culture format increased the L-cell number so that the signal-to-noise ratio of conventional enzyme-linked immunoassays could be used to monitor GLP-1 secretion in compound screens. To demonstrate the utility of the optimized analytical method, 21 types of beverage sweeteners were screened for their ability to stimulate GLP-1 secretion. Stevioside and cyclamate were found to be the most potent inducers of GLP-1 secretion. This platform enables the quantification of GLP-1 secretion from human primary L-cells and will have broad application in understanding L-cell formation and physiology and will improve the identification of modulators of human feeding behavior. Topics: Animals; Diabetes Mellitus, Type 2; Enteroendocrine Cells; Glucagon-Like Peptide 1; Humans; Intestinal Mucosa; L Cells; Mice | 2022 |
Dietary fiber of Tartary buckwheat bran modified by steam explosion alleviates hyperglycemia and modulates gut microbiota in db/db mice.
Type 2 diabetes is a serious threat to human health. Tartary buckwheat bran dietary fiber has good hypoglycemic activity, with its modification widely studied. However, the hypoglycemic activity of steam explosion modified Tartary buckwheat bran soluble dietary fiber (SE-SDF) has not been reported. This research aimed at investigating the hypoglycemic effect with its underlying mechanism of SE-SDF on type 2 diabetic db/db mice. Results found SE-SDF decreased the levels of fasting blood glucose and glycosylated hemoglobin while improved oral glucose tolerance, insulin resistance, and injuries of liver, pancreas, and colon in diabetic db/db mice. Additionally, SE-SDF up-regulated the protein expression levels of hepatic phosphatidylinositol 3 kinase (PI3K), G protein-coupled receptor43 (GPR43), and phospho-adenosine monophosphate activated protein kinase (p-AMPK), whereas inhibited the protein expression levels of hepatic fork-head transcription factor O1 (FoxO1), phosphoenolpyruvate carboxy kinase (PEPCK) and glucose-6-phosphatase (G-6-Pase). Moreover, SE-SDF increased the production of fecal short chain fatty acids (SCFAs) and the expression of colon GPR43 and the concentration of serum glucagon like peptide-1 (GLP-1), leading to reduced ratio of Firmicutes/Bacteroidetes but increased relative abundance of Parabacteroides, norank_f_Muribaculaceae, Alloprevotella, Ruminiclostridium_9, unclassified_f_Ruminococcaceae, and Lachnospiraceae_NK4A136_group. These findings suggested that SE-SDF ameliorated type 2 diabetes via activating the liver PI3K/Akt/FoxO1 and GPR43/AMPK signaling pathways and modulating the gut microbiota-SCFAs-GPR43/GLP-1 signaling axis. Topics: AMP-Activated Protein Kinases; Animals; Diabetes Mellitus, Type 2; Dietary Fiber; Fagopyrum; Fatty Acids, Volatile; Gastrointestinal Microbiome; Glucagon-Like Peptide 1; Hyperglycemia; Hypoglycemic Agents; Mice; Phosphatidylinositol 3-Kinases; Steam | 2022 |
Anti-diabetic effect of banana peel dietary fibers on type 2 diabetic mellitus mice induced by streptozotocin and high-sugar and high-fat diet.
We used a high-fat diet (HFD) and streptozotocin (STZ) to induce type 2 diabetic mellitus (T2DM) mice and evaluated the effect of banana peel dietary fibers (BP-DFs) as potential hypoglycemic agents. After 5 weeks of intervention with banana peel dietary fibers (BP-DFs), food intake was reduced, body weight was increased, blood lipids and glucose were reduced, fasting insulin and GLP-1 levels were increased, and liver and pancreatic tissue damage was reduced. Banana peel soluble dietary fiber (BP-SDF) has the most significant effect. The results of fecal microbiota analysis showed that BP-DFs could ameliorates gut microbiome dysbiosis, and all three types of dietary fibers have obvious effects. The results of fecal short-chain fatty acids (SCFAs) showed that the content of fecal SCFAs was increased after BP-DFs dietary intervention, and BP-SDF had the most obvious effect. RT-PCR experiment results show that BP-DFs can up-regulate the mRNA expression levels of PI3K, AKT, IRS-1, and FOXO1 in the liver of diabetic mice, which indicates that BD-DFs may play a role in improving insulin resistance and insulin signal transduction via the IRS/PI3K/AKT pathway, improving insulin resistance and insulin signal transduction. Our research may be extended to BP-DFs, especially BP-SDF, as the basis for potential dietary intervention to prevent or treat type 2 diabetic mellitus. This work supports future research studies of the anti-diabetic properties of BP-SDF in humans. PRACTICAL APPLICATIONS: Diabetes can lead to a variety of complications that have a huge impact on health. Dietary fiber may help in lowering blood sugar. Our experimental results showed that banana peel dietary fibers have the effect of reducing food intake, blood sugar, improving liver and pancreas function, increasing the abundance of intestinal flora, and improving the IRS/PI3K/AKT pathway in T2DM mice. Therefore, this study could provide a theoretical basis for the development of functional foods with banana peel dietary fiber. Topics: Animals; Blood Glucose; Diabetes Mellitus, Experimental; Diabetes Mellitus, Type 2; Diet, High-Fat; Dietary Fiber; Glucagon-Like Peptide 1; Glucose; Humans; Hypoglycemic Agents; Insulin; Insulin Resistance; Lipids; Mice; Musa; Phosphatidylinositol 3-Kinases; Proto-Oncogene Proteins c-akt; RNA, Messenger; Streptozocin | 2022 |
GLP-1 Receptor Blockade Reduces Stimulated Insulin Secretion in Fasted Subjects With Low Circulating GLP-1.
Glucagon-like peptide 1 (GLP-1), an insulinotropic peptide released into the circulation from intestinal enteroendocrine cells, is considered a hormonal mediator of insulin secretion. However, the physiological actions of circulating GLP-1 have been questioned because of the short half-life of the active peptide. Moreover, there is mounting evidence for localized, intra-islet mediation of GLP-1 receptor (GLP-1r) signaling including a role for islet dipeptidyl-peptidase 4 (DPP4).. To determine whether GLP-1r signaling contributes to insulin secretion in the absence of enteral stimulation and increased plasma levels, and whether this is affected by DPP4.. Single-site study conducted at an academic medical center of 20 nondiabetic subjects and 13 subjects with type 2 diabetes. This was a crossover study in which subjects received either a DPP4 inhibitor (DPP4i; sitagliptin) or placebo on 2 separate days. On each day they received a bolus of intravenous (IV) arginine during sequential 60-minute infusions of the GLP-1r blocker exendin[9-39] (Ex-9) and saline. The main outcome measures were arginine-stimulated secretion of C-Peptide (C-PArg) and insulin (InsArg).. Plasma GLP-1 remained at fasting levels throughout the experiments and IV arginine stimulated both α- and β-cell secretion in all subjects. Ex-9 infusion reduced C-PArg in both the diabetic and nondiabetic groups by ~14% (P < .03 for both groups). Sitagliptin lowered baseline glycemia but did not affect the primary measures of insulin secretion. However, a significant interaction between sitagliptin and Ex-9 suggested more GLP-1r activation with DPP4i treatment in subjects with diabetes.. GLP-1r activation contributes to β-cell secretion in diabetic and nondiabetic people during α-cell activation, but in the absence of increased circulating GLP-1. These results are compatible with regulation of β-cells by paracrine signals from α-cells. This process may be affected by DPP4 inhibition. Topics: Arginine; Cross-Over Studies; Diabetes Mellitus, Type 2; Dipeptidyl Peptidase 4; Fasting; Glucagon-Like Peptide 1; Glucagon-Like Peptide-1 Receptor; Humans; Insulin; Insulin Secretion; Sitagliptin Phosphate | 2022 |
Population pharmacokinetic of paracetamol and atorvastatin with co-administration of semaglutide.
Semaglutide is a glucagon-like-peptide-1 (GLP-1) analogue marketed for once-weekly subcutaneous administration for type 2 diabetes mellitus. Like other long-acting GLP-1 analogues, semaglutide reduces gastric emptying and, potentially, alters the rate of absorption of orally co-administered drugs. The objective of the current analysis was to evaluate the effects on the gastric emptying rate caused by semaglutide on pharmacokinetic model parameters of paracetamol and atorvastatin in healthy subjects. Non-linear mixed effect modeling was used to estimate population pharmacokinetic model parameters of paracetamol and atorvastatin after single doses with or without semaglutide. The absorption rate (ka) of paracetamol decreased by 53% when co-administered with semaglutide. For atorvastatin, ka and transit compartment rate (ktr) decreased by 72% and 91%, respectively. Thus, gastric emptying, measured as T50, i.e., drug disappearance from the absorption compartments, showed an additional 5-min delay for paracetamol and a 67-min delay for atorvastatin when co-administered with semaglutide. Semaglutide affected pharmacokinetic model parameters of paracetamol and atorvastatin, and minor quantitative differences in gastric emptying between placebo vs. semaglutide administration were observed. However, these effects of semaglutide were considered not to be of clinical relevance. Topics: Acetaminophen; Atorvastatin; Diabetes Mellitus, Type 2; Glucagon-Like Peptide 1; Glucagon-Like Peptides; Humans; Hypoglycemic Agents | 2022 |
Analysis of Intestinal Short-Chain Fatty Acid Metabolism Profile After Probiotics and GLP-1 Treatment for Type 2 Diabetes Mellitus.
Type 2 diabetes accounts for about 90% of diabetes patients, and the incidence of diabetes is on the rise as people's lifestyles change. Compared with GLP-1 treatment, probiotic treatment can directly regulate homeostasis of the host gut microbe, and thus homeostasis of its metabolites. Currently, the regulatory role of probiotics on intestinal metabolites after treatment of type 2 diabetes mellitus remains unclear. The purpose of this study was to investigate the therapeutic effect of probiotics on type 2 diabetes mellitus and its regulatory effect on short-chain fatty acids, which are metabolites of intestinal microorganisms. I collected feces from 15 patients with diabetes before treatment and 15 patients with type 2 diabetes after treatment with GLP-1 and probiotics. The abundance of short-chain fatty acids in feces was determined by GC-MS. Results Both GLP-1 and probiotics could improve the levels of blood glucose, urine glucose and BMI in patients with type 2 diabetes. After glP-1 treatment, two short-chain fatty acids (butyric acid and valerate acid) in intestine were significantly changed. Propionic acid and isovalerate were significantly changed after probiotic treatment. At the same time, KEGG signal pathway enrichment results showed that probiotics intervention mainly achieved the purpose of treating type 2 diabetes through regulating protein and carbohydrate metabolism. Taken together, our study shows changes in intestinal short-chain fatty acids after probiotics or GLP-1 treatment of type 2 diabetes, which will provide us with new insights into the mechanism of probiotics treatment of type 2 diabetes, as well as potential intervention targets for diabetes treatment. Topics: Blood Glucose; Diabetes Mellitus, Type 2; Fatty Acids, Volatile; Glucagon-Like Peptide 1; Humans; Probiotics | 2022 |
The potential mechanism of Liu-Wei-Di-Huang Pills in treatment of type 2 diabetic mellitus: from gut microbiota to short-chain fatty acids metabolism.
Type 2 diabetes mellitus (T2DM) has already become a global pandemic. Recently, reports showed its pathogenesis was closely related to a disorder of gut microbiota. In China, the Liu-Wei-Di-Huang Pills (LWDH) have treated T2DM for thousands of years. However, its therapeutic mechanism associated with gut microbiota is worthy of further study.. This study aims to investigate the effects of LWDH on T2DM by regulating gut microbiota and short-chain fatty acids (SCFAs) in Goto-Kakizaki (GK) rats.. T2DM models were successfully established based on GK rats and administrated with LWDH. The changes in fasting blood glucose (FBG), oral glucose tolerance test (OGTT), and serum insulin (INS) were determined, and the immunohistochemical (IHC) method was used to test INS expression in pancreas. The 16S-ribosomal DNA (16S rDNA) sequencing analysis assessed gut microbiota structural changes; a gas chromatography-mass spectrometer (GC-MS)-based metabolomics method was adopted to detect SCFA levels. The pathological morphology of jejunum was detected by hematoxylin-eosin (H&E) staining, and the expression of GPR43, GPR41, GLP-1, and GLP-1R was evaluated by qRT-PCR and ELISA, respectively.. We observed that GK rats treated with LWDH: (a) has altered the microbial structure and promoted the abundance of bacteria in Firmicutes, including Lactobacillus, Allobaculum, and Ruminococcus_2, (b) increased SCFAs levels involving acetic acid, propionic acid, and butyric acid and (c) alleviated T2DM and jejunum injuries potentially based on SCFAs-GPR43/41-GLP-1 pathway.. LWDH could improve T2DM by regulating gut microbiota and SCFAs, and the therapeutic mechanism might be related to the SCFAs-GPR43/41-GLP-1 pathway. Topics: Animals; Diabetes Mellitus, Type 2; Fatty Acids, Volatile; Gastrointestinal Microbiome; Glucagon-Like Peptide 1; Lipid Metabolism; Rats | 2022 |
Incretin-Based Drugs and the Risk of Acute Liver Injury Among Patients With Type 2 Diabetes.
To determine whether the use of dipeptidyl peptidase 4 (DPP-4) inhibitors and glucagon-like peptide 1 receptor agonists (GLP-1 RAs), separately, is associated with an increased risk of acute liver injury compared with the use of sodium-glucose cotransporter 2 (SGLT-2) inhibitors.. We used the U.K. Clinical Practice Research Datalink linked with the Hospital Episode Statistics Admitted Patient Care and the Office for National Statistics databases to assemble two new-user, active-comparator cohorts. The first included 106,310 initiators of DPP-4 inhibitors and 27,277 initiators of SGLT-2 inhibitors, while the second included 9,470 initiators of GLP-1 RAs and 26,936 initiators of SGLT-2 inhibitors. Cox proportional hazards models with propensity score fine stratification weighting were used to estimate hazard ratios (HRs) and 95% CIs of acute liver injury.. Compared with SGLT-2 inhibitors, DPP-4 inhibitors were associated with a 53% increased risk of acute liver injury (HR 1.53, 95% CI 1.02-2.30). In contrast, GLP-1 RAs were not associated with an overall increased risk of acute liver injury (HR 1.11, 95% CI 0.57-2.16). However, an increased risk was observed among female users of both DPP-4 inhibitors (HR 3.22, 95% CI 1.67-6.21) and GLP-1 RAs (HR 3.23, 95% CI 1.44-7.25).. In this population-based study, DPP-4 inhibitors were associated with an increased risk of acute liver injury compared with SGLT-2 inhibitors in patients with type 2 diabetes. In contrast, an increased risk of acute liver injury was observed only among female GLP-1 RA users. Topics: Diabetes Mellitus, Type 2; Dipeptidyl Peptidase 4; Dipeptidyl-Peptidase IV Inhibitors; Female; Glucagon-Like Peptide 1; Glucagon-Like Peptide-1 Receptor; Glucose; Humans; Hypoglycemic Agents; Incretins; Liver; Sodium; Sodium-Glucose Transporter 2 Inhibitors | 2022 |
The Real-World Observational Prospective Study of Health Outcomes with Dulaglutide and Liraglutide in Patients with Type 2 Diabetes (TROPHIES): Patient disposition, clinical characteristics and treatment persistence at 12 months.
The primary objective of the TROPHIES observational study is to estimate the duration of treatment on dulaglutide or liraglutide without a significant treatment change by 24 months in patients with type 2 diabetes (T2D) initiating their first injectable treatment with these glucagon-like peptide-1 receptor agonists (GLP-1 RAs). This manuscript presents 12-month interim data.. TROPHIES is a prospective, non-comparative, observational study of patients with T2D in Europe, naïve to injectable antihyperglycaemic treatments and initiating dulaglutide or liraglutide. Data on clinical characteristics, GLP-1 RA persistence and treatment patterns of glucose-lowering medication were collected at initiation of first injectable therapy and by 12 months.. By 12 months, 1014 dulaglutide and 991 liraglutide patients were eligible across France, Germany and Italy. Both cohorts presented a high probability [95% confidence interval (CI)] of GLP-1 RA persistence [dulaglutide, 0.88 (0.86 to 0.90); liraglutide, 0.83 (0.80 to 0.85)] and reduction in mean glycated haemoglobin percentage (95% CI) from baseline [dulaglutide, -1.18 (-1.27 to -1.08); liraglutide, -1.15 (-1.26 to -1.05)] with 48.2% of dulaglutide and 41.2% of liraglutide patients reaching their individualized glycated haemoglobin percentage target set by the physician at baseline. Mean weight (95% CI) change from baseline was -3.2 kg (-3.6 to -2.8) for dulaglutide and -3.4 kg (-3.9 to -3.0) for liraglutide. Slight changes in concomitant medications were observed compared with baseline.. In the real-world setting, dulaglutide and liraglutide cohorts achieved good persistence with similarly improved glycaemic control that was accompanied by weight loss at 12 months, consistent with previous clinical trial results. Topics: Diabetes Mellitus, Type 2; Drug Administration Schedule; Glucagon-Like Peptide 1; Glucagon-Like Peptide-1 Receptor; Glucagon-Like Peptides; Glycated Hemoglobin; Humans; Hypoglycemic Agents; Immunoglobulin Fc Fragments; Liraglutide; Outcome Assessment, Health Care; Prospective Studies; Recombinant Fusion Proteins | 2022 |
Disrupted and Elevated Circadian Secretion of Glucagon-Like Peptide-1 in a Murine Model of Type 2 Diabetes.
Metabolism and circadian rhythms are intimately linked, with circadian glucagon-like peptide-1 (GLP-1) secretion by the intestinal L-cell entraining rhythmic insulin release. GLP-1 secretion has been explored in the context of obesogenic diets, but never in a rodent model of type 2 diabetes (T2D). There is also considerable disagreement regarding GLP-1 levels in human T2D. Furthermore, recent evidence has demonstrated decreased expression of the β-cell exocytotic protein secretagogin (SCGN) in T2D. To extend these findings to the L-cell, we administered oral glucose tolerance tests at 6 time points in 4-hour intervals to the high-fat diet/streptozotocin (HFD-STZ) mouse model of T2D. This revealed a 10-fold increase in peak GLP-1 secretion with a phase shift of the peak from the normal feeding period into the fasting-phase. This was accompanied by impairments in the rhythms of glucose, glucagon, mucosal clock genes (Arntl and Cry2), and Scgn. Immunostaining revealed that L-cell GLP-1 intensity was increased in the HFD-STZ model, as was the proportion of L-cells that expressed SCGN; however, this was not found in L-cells from humans with T2D, which exhibited decreased GLP-1 staining but maintained their SCGN expression. Gcg expression in isolated L-cells was increased along with pathways relating to GLP-1 secretion and electron transport chain activity in the HFD-STZ condition. Further investigation into the mechanisms responsible for this increase in GLP-1 secretion may give insights into therapies directed toward upregulating endogenous GLP-1 secretion. Topics: Animals; Circadian Rhythm; Diabetes Mellitus, Type 2; Disease Models, Animal; Glucagon; Glucagon-Like Peptide 1; Glucose Tolerance Test; Humans; Insulin; Mice | 2022 |
Exenatide challenge in oral glucose tolerance test is insufficient for predictions of glucose metabolism and insulin secretion after sleeve gastrectomy (SG) in obese patients with type 2 diabetes: a pilot study to establish a preoperative model to estimat
The postoperative increase in glucagon-like peptide-1 (GLP-1) is the main factor to improve glucose metabolism following sleeve gastrectomy (SG) in obese patients with type 2 diabetes. We investigated whether the β-cell responsiveness to an injection of exogenous GLP-1 in the preoperative period could determine the postoperative glucose tolerance in 18 patients underwent SG. In the preoperative period, a regular oral glucose tolerance test (OGTT) and an exenatide-challenge during OGTT (Ex-OGTT) were performed to evaluate the β-cell function and its responsiveness to GLP-1. The postoperative glucose tolerance was evaluated by another regular OGTT performed at 3 months after SG. The significant decrease in glucose levels with enhanced secretions of insulin and GLP-1 was observed in OGTT at 3 months after SG. The area under the curve of glucose from 0 to 120 minutes (AUC glucose Topics: Blood Glucose; Diabetes Mellitus, Type 2; Exenatide; Gastrectomy; Glucagon-Like Peptide 1; Glucose; Glucose Tolerance Test; Humans; Insulin; Insulin Secretion; Obesity; Pilot Projects | 2022 |
Islet MC4R Regulates PC1/3 to Improve Insulin Secretion in T2DM Mice via the cAMP and β-arrestin-1 Pathways.
Melanocortin-4 receptor (MC4R) plays an important role in energy balance regulation and insulin secretion. It has been demonstrated that in the pancreas, it is expressed in islet α and β cells, wherein it is significantly correlated with insulin and glucagon-like peptide-1 (GLP-1) secretion. However, the molecular mechanism by which it regulates islet function is still unclear. Therefore, in this study, our aim was to clarify the signaling and target genes involved in the regulation of insulin and GLP-1 secretion by islet MC4R. The results obtained showed that in islet cells, the expression of prohormone convertase 1/3 (PC1/3), which is correlated with islet GLP-1 and insulin secretion, increased significantly under the action of the MC4R agonist, NDP-α-MSH, but decreased under the action of the MC4R antagonist, AgRP. Additionally, we observed that to exert their regulatory functions in the islets, cAMP and β-arrestin-1 acted as important signaling mediators of MC4R, and compared with control islets, the cAMP, PKA, and β-arrestin-1 levels corresponding to NDP-α-MSH-treated islets were significantly elevated; however, in AgRP-treated islets, their levels decreased significantly. Islets treated with the PKA inhibitor, H89, and the ERK1/2 inhibitor, PD98059, also showed significant decreases in PC1/3 expression level, indicating that the cAMP and β-arrestin-1 pathways are significantly correlated with PC1/3 expression. These findings suggest that islet MC4R possibly affects PC1/3 expression via the cAMP and β-arrestin-1 pathways to regulate GLP-1 and insulin secretion. These results provide a new theoretical basis for targeting the molecular mechanism of type 2 diabetes mellitus. Topics: Agouti-Related Protein; Animals; beta-Arrestin 1; Diabetes Mellitus, Type 2; Glucagon-Like Peptide 1; Glucose; Insulin; Insulin Secretion; Islets of Langerhans; Mice; Proprotein Convertase 1; Receptor, Melanocortin, Type 4 | 2022 |
Translating results from the cardiovascular outcomes trials with glucagon-like peptide-1 receptor agonists into clinical practice: Recommendations from a Eastern and Southern Europe diabetes expert group.
Glucagon-like peptide-1 (GLP-1) receptor agonists mimic the action of the endogenous GLP-1 incretin hormone, improving glycaemic control in type 2 diabetes mellitus (T2DM) by increasing insulin secretion and decreasing glucagon secretion in a glucose-dependent manner. However, as cardiovascular (CV) morbidity and mortality is common in patients with T2DM, several trials with the use of GLP-1 receptor agonists (RAs) have been performed focusing on endpoints related to cardiovascular disease rather than metabolic control of T2DM. Following the positive cardiovascular effects of liraglutide, dulaglutide and semaglutide observed in these trials, major changes in T2DM management guidelines have occurred. This document from a Eastern and Southern European Diabetes Expert Group discusses the results of GLP-1 RA CV outcomes trials, their impact on recent clinical guidelines for the management of T2DM, and some selected combination regimens utilising GLP-1 RAs. We also propose an algorithm for guiding GLP-1 RA-based treatment according to patients' characteristics, which can be easily applied in every day clinical practice. Topics: Cardiovascular Diseases; Diabetes Mellitus, Type 2; Glucagon-Like Peptide 1; Glucagon-Like Peptide-1 Receptor; Humans; Hypoglycemic Agents; Liraglutide | 2022 |
Isseki nichō (one stone, two birds): a dual incretin receptor agonist for type 2 diabetes.
Topics: Diabetes Mellitus, Type 2; Dipeptidyl-Peptidase IV Inhibitors; Gastric Inhibitory Polypeptide; Glucagon-Like Peptide 1; Glucagon-Like Peptide-1 Receptor; Humans; Hypoglycemic Agents; Incretins | 2022 |
Usefulness of circulating EPAC1 as biomarkers of therapeutic response to GLP-1 receptor agonists.
The response to Glucagon-like peptide-1 receptor agonists (GLP-1RAs) is highly varia-ble among patients. Thus, the identification of predictive biomarkers of therapeutic response to GLP-1 RA could help us to optimize the use of this class of drugs. GLP-1RAs increase exchange proteins directly activated by cAMP (EPAC). The aim of the present study was to assess whether the increase of EPAC1 after GLP-1RAs treatment could be a biomarker of clinical response.. After showing that GLP-1 (10 ng/mL) significantly increased the expression of EPAC1 in human endo-thelial vascular cells (HUVEC), a pilot clinical study was planned. For this purpose 49 patients with type 2 diabetes who started treatment with liraglutide were included. EPAC1 concentration was determined by ELISA before and at one month of liraglutide treatment.. We found that serum concentration of EPAC1 increased significantly after treatment with liraglutide. Only in those patients in whom EPAC1 increased (64%), a significant decrease in HbA1c, LDL-C, body mass index (BMI), and waist circumference was shown.. This pilot study suggests that the increase of circulating EPAC1 after GLP-1RAs treatment could be a useful biomarker to predict clinical GLP1-RAs response. Topics: Biomarkers; Cholesterol, LDL; Diabetes Mellitus, Type 2; Glucagon-Like Peptide 1; Glucagon-Like Peptide-1 Receptor; Glycated Hemoglobin; Guanine Nucleotide Exchange Factors; Humans; Hypoglycemic Agents; Liraglutide; Pilot Projects | 2022 |
Comparative Effects of Co-Ingesting Whey Protein and Glucose Alone and Combined on Blood Glucose, Plasma Insulin and Glucagon Concentrations in Younger and Older Men.
The ingestion of dietary protein with, or before, carbohydrate may be a useful strategy to reduce postprandial hyperglycemia, but its effect in older people, who have an increased predisposition for type 2 diabetes, has not been clarified. Blood glucose, plasma insulin and glucagon concentrations were measured for 180 min following a drink containing either glucose (120 kcal), whey-protein (120 kcal), whey-protein plus glucose (240 kcal) or control (~2 kcal) in healthy younger (n = 10, 29 ± 2 years; 26.1 ± 0.4 kg/m2) and older men (n = 10, 78 ± 2 years; 27.3 ± 1.4 kg/m2). Mixed model analysis was used. In both age groups the co-ingestion of protein with glucose (i) markedly reduced the increase in blood glucose concentrations following glucose ingestion alone (p < 0.001) and (ii) had a synergistic effect on the increase in insulin concentrations (p = 0.002). Peak insulin concentrations after protein were unaffected by ageing, whereas insulin levels after glucose were lower in older than younger men (p < 0.05) and peak insulin concentrations were higher after glucose than protein in younger (p < 0.001) but not older men. Glucagon concentrations were unaffected by age. We conclude that the ability of whey-protein to reduce carbohydrate-induced postprandial hyperglycemia is retained in older men and that protein supplementation may be a useful strategy in the prevention and management of type 2 diabetes in older people. Topics: Aged; Blood Glucose; Diabetes Mellitus, Type 2; Glucagon; Glucagon-Like Peptide 1; Glucose; Humans; Hyperglycemia; Insulin; Male; Postprandial Period; Whey Proteins | 2022 |
Practical Considerations for Use of Insulin/Glucagon-Like Peptide 1 Receptor Agonist Combinations in Older Adults With Type 2 Diabetes.
Over 25% of adults ≥65 years of age have type 2 diabetes (T2D). Individualization of care is important in older adults with T2D, with treatment targets and therapeutic approaches informed by patient-specific medical, psychosocial, functional, and social considerations. Fixed-ratio combination injectable products offer unique benefits in older adults, including reduction of both fasting and postprandial glucose, low hypoglycemia risk, lack of weight gain, fewer gastrointestinal side effects, strong durability of effect, and the potential for medication regimen simplification. Topics: Aged; Blood Glucose; Diabetes Mellitus, Type 2; Glucagon-Like Peptide 1; Glucagon-Like Peptide-1 Receptor; Humans; Hypoglycemic Agents; Insulin | 2022 |
Association between use of novel glucose-lowering drugs and COVID-19 hospitalization and death in patients with type 2 diabetes: a nationwide registry analysis.
Type 2 diabetes (T2DM) in patients with coronavirus disease-19 (COVID-19) is associated with a worse prognosis. We separately investigated the associations between the use of sodium-glucose cotransporter 2 inhibitors (SGLT2i), glucagon-like peptide-1 receptor agonists (GLP-1 RA), and dipeptidyl peptidase-4 inhibitors (DPP-4i), and the risk of COVID-19 hospitalization and death.. Patients with T2DM registered in the Swedish National Patient Registry and alive on 1 February 2020 were included. 'Incident severe COVID-19' was defined as the first hospitalization and/or death from COVID-19. A modified Poisson regression approach was applied to a 1:1 propensity score-matched population receiving vs. not receiving SGLT2i, GLP-1 RA, and DPP-4i to analyse the associations between their use and (I) incident severe COVID-19 and (II) risk of 30-day mortality in patients hospitalized for COVID-19.Among 344 413 patients, 39 172 (11%) were treated with SGLT2i, 34 290 (10%) with GLP-1 RA, and 53 044 (15%) with DPP-4i; 9538 (2.8%) had incident severe COVID-19 by 15 May 2021. SGLT2i and DPP-4i were associated with a 10% and 11% higher risk of incident severe COVID-19, respectively, whereas there was no association for GLP-1 RA. DPP-4i was also associated with a 10% higher 30-day mortality in patients hospitalized for COVID-19, whereas there was no association for SGLT2i and GLP-1 RA.. SGLT2i and DPP-4i use were associated with a higher risk of incident severe COVID-19. DPP-4i use was associated with higher 30-day mortality in patients with COVID-19, whereas SGLT2i use was not. No increased risk for any outcome was observed with GLP-1 RA. Topics: COVID-19; Diabetes Mellitus, Type 2; Dipeptidyl-Peptidase IV Inhibitors; Glucagon-Like Peptide 1; Glucagon-Like Peptide-1 Receptor; Glucose; Hospitalization; Humans; Registries | 2022 |
Use of GLP-1 receptor agonists and subsequent risk of alcohol-related events. A nationwide register-based cohort and self-controlled case series study.
Animal studies have related glucagon-like peptide 1 receptor agonists (GLP-1) to lower alcohol intake. We examined whether GLP-1 was associated with risk of alcohol-related events in a nationwide cohort study and a self-controlled case series analysis including all new users of GLP1 (n = 38 454) and dipeptidyl peptidase 4 inhibitors (DPP4) (n = 49 222) in Denmark 2009-2017. They were followed for hospital contacts with alcohol use disorder or purchase of drugs for treatment of alcohol dependence in nationwide registers from 2009 to 2018. Associations were examined using Cox proportional hazard and conditional Poisson regression. During follow-up of median 4.1 years, 649 (0.7%) of participants were registered with an alcohol-related event. Initiation of GLP-1 treatment was associated with lower risk of an alcohol-related event (Hazard ratio = 0.46 (95%CI: 0.24-0.86) compared with initiation of DPP4 during the first 3 months of follow-up. Self-controlled analysis showed the highest risk of alcohol-related events in the 3-month pretreatment period (incidence rate ratio [IRR] = 1.25 (1.00-1.58)), whereas the risk was lowest in the first 3-month treatment period (IRR = 0.74 (0.56-0.97). In conclusion, compared with DPP4 users, individuals who start treatment with GLP-1 had lower incidence of alcohol-related events both in cohort and self-controlled analyses. Thus, there might be a transient preventive effect of GLP1 on alcohol-related events the first months after treatment initiation. Topics: Cohort Studies; Diabetes Mellitus, Type 2; Dipeptidyl Peptidase 4; Dipeptidyl-Peptidase IV Inhibitors; Glucagon-Like Peptide 1; Glucagon-Like Peptide-1 Receptor; Humans; Hypoglycemic Agents | 2022 |
Trends in Prescribing Preferences for Antidiabetic Medications Among Patients With Type 2 Diabetes in the U.K. With and Without Chronic Kidney Disease, 2006-2020.
To evaluate trends in antidiabetic medication initiation patterns among patients with type 2 diabetes mellitus (T2DM) with and without chronic kidney disease (CKD).. A retrospective cohort study using the UK Clinical Practice Research Datalink (2006-2020) was conducted to evaluate the overall, first-, and second line (after metformin) medication initiation patterns among patients with CKD (n = 38,622) and those without CKD (n = 230,963) who had T2DM.. Relative to other glucose-lowering therapies, metformin initiations declined overall but remained the first-line treatment of choice for both patients with and those without CKD. Sodium-glucose cotransporter-2 (SGLT2i) use increased modestly among patients with CKD, but this increase was more pronounced among patients without CKD; by 2020, patients without CKD, compared with patients with CKD, were three (28.5% vs. 9.4%) and six (46.3% vs. 7.9%) times more likely to initiate SGLT2i overall and as second-line therapy, respectively. Glucagon-like peptide 1 receptor agonist (GLP-1RA) use was minimal regardless of CKD status (<5%), whereas both dipeptidyl peptidase-4 inhibitor (DPP4i) and sulfonylurea use remained high among patients with CKD. For instance, by 2020, and among patients with CKD, DPP4i and sulfonylureas constituted 28.3% and 20.6% of all initiations, and 57.4% and 30.3% of second-line initiations, respectively.. SGLT2i use increased among patients with T2DM, but this increase was largely driven by patients without CKD. Work is needed to identify barriers associated with the uptake of therapies with proven cardiorenal benefits (e.g., SGLT2i, GLP-1RA) among patients with CKD. Topics: Diabetes Mellitus, Type 2; Dipeptidyl-Peptidase IV Inhibitors; Dipeptidyl-Peptidases and Tripeptidyl-Peptidases; Glucagon-Like Peptide 1; Glucagon-Like Peptide-1 Receptor; Glucose; Humans; Hypoglycemic Agents; Metformin; Renal Insufficiency, Chronic; Retrospective Studies; Sodium; Sodium-Glucose Transporter 2 Inhibitors; Sulfonylurea Compounds | 2022 |
GLP-1-mediated delivery of tesaglitazar improves obesity and glucose metabolism in male mice.
Dual agonists activating the peroxisome proliferator-activated receptors alpha and gamma (PPARɑ/ɣ) have beneficial effects on glucose and lipid metabolism in patients with type 2 diabetes, but their development was discontinued due to potential adverse effects. Here we report the design and preclinical evaluation of a molecule that covalently links the PPARɑ/ɣ dual-agonist tesaglitazar to a GLP-1 receptor agonist (GLP-1RA) to allow for GLP-1R-dependent cellular delivery of tesaglitazar. GLP-1RA/tesaglitazar does not differ from the pharmacokinetically matched GLP-1RA in GLP-1R signalling, but shows GLP-1R-dependent PPARɣ-retinoic acid receptor heterodimerization and enhanced improvements of body weight, food intake and glucose metabolism relative to the GLP-1RA or tesaglitazar alone in obese male mice. The conjugate fails to affect body weight and glucose metabolism in GLP-1R knockout mice and shows preserved effects in obese mice at subthreshold doses for the GLP-1RA and tesaglitazar. Liquid chromatography-mass spectrometry-based proteomics identified PPAR regulated proteins in the hypothalamus that are acutely upregulated by GLP-1RA/tesaglitazar. Our data show that GLP-1RA/tesaglitazar improves glucose control with superior efficacy to the GLP-1RA or tesaglitazar alone and suggest that this conjugate might hold therapeutic value to acutely treat hyperglycaemia and insulin resistance. Topics: Alkanesulfonates; Animals; Body Weight; Diabetes Mellitus, Type 2; Glucagon-Like Peptide 1; Glucagon-Like Peptide-1 Receptor; Glucose; Male; Mice; Obesity; Phenylpropionates; PPAR alpha | 2022 |
In vivo drug discovery for increasing incretin-expressing cells identifies DYRK inhibitors that reinforce the enteroendocrine system.
Analogs of the incretin hormones Gip and Glp-1 are used to treat type 2 diabetes and obesity. Findings in experimental models suggest that manipulating several hormones simultaneously may be more effective. To identify small molecules that increase the number of incretin-expressing cells, we established a high-throughput in vivo chemical screen by using the gip promoter to drive the expression of luciferase in zebrafish. All hits increased the numbers of neurogenin 3-expressing enteroendocrine progenitors, Gip-expressing K-cells, and Glp-1-expressing L-cells. One of the hits, a dual-specificity tyrosine phosphorylation-regulated kinase (DYRK) inhibitor, additionally decreased glucose levels in both larval and juvenile fish. Knock-down experiments indicated that nfatc4, a downstream mediator of DYRKs, regulates incretin Topics: Animals; Diabetes Mellitus, Experimental; Diabetes Mellitus, Type 2; Drug Discovery; Gastric Inhibitory Polypeptide; Glucagon-Like Peptide 1; Glucose; Incretins; Mice; Tyrosine; Zebrafish | 2022 |
Effectiveness and safety of GLP-1 receptor agonists versus SGLT-2 inhibitors in type 2 diabetes: an Italian cohort study.
GLP-1 receptor agonists (GLP-1 RA) and SGLT-2 inhibitors (SGLT-2i) have shown to reduce the risk of major adverse cardiovascular events (MACE), death and worsening nephropathy when added to standard of care. However, these two dug classes differ in efficacy and safety. We compared the effectiveness and safety profile of GLP-1 RA and SGLT-2i in a large and unselected cohort of patients with type 2 diabetes resident in Lombardy from 2015 to 2020.. Using linkable administrative health databases, we included patients aged 50 years and older initiating GLP-1 RA or SGLT-2i. Clinical events were: death, hospital admission for myocardial infarction (MI), stroke, heart failure (HF), and renal disease as individual and composite outcomes (MACE-3: all cause-death, non-fatal MI, non-fatal stroke; MACE-4: MACE-3 plus unstable angina). Outcomes were evaluated separately in subjects with and without previous cardiovascular (CV) diseases. Treatments were compared using Cox proportional hazards regression model after Propensity Score Matching (PSM) in both intention-to-treat (ITT) and per protocol (PP) analyses. Serious adverse events were also evaluated.. The analysis comprised 20,762 patients per cohort. The ITT analysis showed a significant risk reduction for non-fatal MI (HR 0.77; CI 95% 0.66-0.90), MACE-3 (HR 0.91; CI 95% 0.84-0.98), and MACE-4 (HR 0.92; CI 95% 0.86-0.99) in GLP-1RA compared with SGLT-2i users, while no difference was reported in the incidence of HF hospitalization and stroke between the two cohorts. Similar benefits were found in the subgroup of patients without previous CV diseases only. PP analysis largely confirmed the main results. The incidence of serious adverse events was low in both cohorts (< 1%).. GLP-1RA showed to be equally safe and more effective than SGLT-2i in reducing the risk of MACE-3, MACE-4 and MI. This study adds to the growing body of real-world evidence addressing the specific clinical properties of GLP-1RA and SGLT-2i in everyday practice to tailor treatment to the individual patient. Topics: Aged; Cardiovascular Diseases; Cohort Studies; Diabetes Mellitus, Type 2; Glucagon-Like Peptide 1; Glucagon-Like Peptide-1 Receptor; Humans; Hypoglycemic Agents; Middle Aged; Sodium-Glucose Transporter 2 Inhibitors; Stroke | 2022 |
Oral glucagon-like peptide 1 analogue ameliorates glucose intolerance in db/db mice.
We constructed a recombinant oral GLP-1 analogue in Lactococcus lactis (L. lactis) and evaluated its physiological functions.. In silico docking suggested the alanine at position 8 substituted with serine (A8SGLP-1) reduced binding of DPP4, which translated to reduced cleavage by DPP4 with minimal changes in stability. This was further confirmed by an in vitro enzymatic assay which showed that A8SGLP-1 significantly increased half-life upon DPP4 treatment. In addition, recombinant L. lactis (LL-A8SGLP-1) demonstrated reduced fat mass with no changes in body weight, significant improvement of random glycemic control and reduced systemic inflammation compared with WT GLP-1 in db/db mice.. LL-A8SGLP-1 adopted in live biotherapeutic products reduce blood glucose in db/db mice without affecting its function. Topics: Alanine; Animals; Blood Glucose; Diabetes Mellitus, Type 2; Dipeptidyl Peptidase 4; Glucagon-Like Peptide 1; Glucose Intolerance; Hypoglycemic Agents; Mice; Mice, Inbred C57BL; Serine | 2022 |
Several birds with one stone; GLP-1 agonists for the glucose control, weight reduction, and prevention of cardiac and renal outcomes.
Topics: Blood Glucose; Diabetes Mellitus, Type 2; Glucagon-Like Peptide 1; Glucagon-Like Peptide-1 Receptor; Humans; Hypoglycemic Agents; Weight Loss | 2022 |
Acute Cholecystitis Associated With the Use of Glucagon-Like Peptide-1 Receptor Agonists Reported to the US Food and Drug Administration.
This case series identifies cases reported in the US Food and Drug Administration Adverse Event Reporting System of acute cholecystitis associated with use of glucagon-like peptide-1 receptor agonists that did not have gallbladder disease warnings in their labeling. Topics: Cholecystitis, Acute; Diabetes Mellitus, Type 2; Glucagon-Like Peptide 1; Glucagon-Like Peptide-1 Receptor; Humans; Hypoglycemic Agents; United States; United States Food and Drug Administration | 2022 |
GLP-1 Targeted Novel 3-phenyl-7-hydroxy Substituted Coumarins Mitigate STZ-induced Pancreatic Damage and Improve Glucose Homeostasis in OGTT Method.
Worldwide, type 2 diabetes mellitus accounts for a considerable burden of disease, with an estimated global cost of >800 billion USD annually. For this reason, the search for more effective and efficient therapeutic anti-diabetic agents is continuing. Recent studies support the search for coumarins or related compounds with potential blood glucose-lowering properties.. The study aims to design, synthesize and evaluate the hypoglycemic activity of a new class of 7-hydroxy coumarin derivatives.. To explore and establish the in-silico-driven pharmacological role of a new class of 7- hydroxy coumarin derivatives as the therapeutic strategies against type 2 diabetes mellitus.. A new class of 7-hydroxy coumarin derivatives was designed by assessment of their physicochemical properties and molecular docking against the Glucagon-like peptide-1 (GLP-1) receptor. Two novel series of 30 compounds were synthesized. The chemical structures of all the synthesized analogues have been elucidated by spectral studies of IR,. The molecular docking studies of synthesized derivatives reveal significant molecular interaction with the various amino acid residues of the GLP-1 receptor. IR spectral analysis revealed a strong band of -NH stretching in the range of 3406.7-3201.61 cm. Coumarin derivatives explored a good structure-activity relationship (SAR) and produced significant hypoglycemic potential. Topics: Blood Glucose; Coumarins; Diabetes Mellitus, Type 2; Glucagon-Like Peptide 1; Glucose Tolerance Test; Homeostasis; Humans; Hypoglycemic Agents; Molecular Docking Simulation; Streptozocin; Structure-Activity Relationship | 2022 |
Editorial: Treatment with Dual Incretin Receptor Agonists to Maintain Normal Glucose Levels May Also Maintain Normal Weight and Control Metabolic Dysfunction-Associated Fatty Liver Disease (MAFLD).
Worldwide, metabolic dysfunction-associated fatty liver disease (MAFLD) is the most common chronic liver disease. MAFLD is associated with insulin resistance, type 2 diabetes mellitus (T2DM), obesity, hypertension, and dyslipidemia. Early diagnosis and management are vital to improving hepatic and cardiometabolic outcomes. Dietary change, weight loss, and structured exercise are the main treatment approaches for fatty liver disease. Since 2010, several investigational drug treatments failed to achieve regulatory approval due to mixed and unsatisfactory results. Although glucagon-like peptide 1 receptor agonists (GLP1-RAs) showed initial promise as therapeutic agents, metabolic liver damage can recur after monotherapy cessation. Dual incretin receptor agonists target the receptors for glucagon-like peptide 1 (GLP-1) and gastric inhibitory peptide (GIP). Importantly, on May 13, 2022, the US Food and Drug Administration (FDA) approved tirzepatide as the first dual GLP-1 and GIP receptor agonist for the treatment of T2DM. Dual incretin receptor agonists induce weight loss and enhance hepatic lipid metabolism and systemic insulin sensitivity. Insulin resistance and hepatic steatosis are the main contributors to the development of MAFLD. Treatment with dual incretin analogs reduces hepatic steatosis, lobular inflammation, liver cell damage, fibrosis, and total liver triglyceride levels. The availability of dual incretin receptor agonists for patients with MAFLD may result in weight control, normalizing insulin sensitivity, and reducing or even reversing metabolic dysfunction and liver damage. This Editorial aims to provide an update and discuss how treatment with dual incretin receptor agonists may maintain normal glucose levels and weight and control MAFLD. Topics: Diabetes Mellitus, Type 2; Glucagon-Like Peptide 1; Glucose; Humans; Incretins; Insulin Resistance; United States; Weight Loss | 2022 |
Glucagon-like peptide 1 receptor agonists in heart failure: the need for a rewind.
Topics: Cardiovascular Diseases; Diabetes Mellitus, Type 2; Glucagon-Like Peptide 1; Glucagon-Like Peptide-1 Receptor; Heart Failure; Humans; Hypoglycemic Agents | 2022 |
Alpha-cells and therapy of diabetes: Inhibition, antagonism or death?
Absolute or relative hyperglucagonaemia is a characteristic of both Type 1 and Type 2 diabetes, resulting in fasting hyperglycaemia due in part to increased hepatic glucose production and lack of postprandial suppression of circulating glucagon concentrations. Consequently, therapeutics that target glucagon secretion or biological action may be effective antidiabetic agents. In this regard, specific glucagon receptor (GCGR) antagonists have been developed that exhibit impressive glucose-lowering actions, but unfortunately may cause off-target adverse effects in humans. Further to this, several currently approved antidiabetic agents, including GLP-1 mimetics, DPP-4 inhibitors, metformin, sulphonylureas and pramlintide likely exert part of their glucose homeostatic actions through direct or indirect inhibition of GCGR signalling. In addition to agents that inhibit the release of glucagon, compounds that enhance the transdifferentiation of glucagon secreting alpha-cells towards an insulin positive beta-cell phenotype could also help curb excess glucagon secretion in diabetes. Use of alpha-cell toxins represents another possible strategy to address hyperglucagonaemia in diabetes. In that respect, research from the 1920 s with diguanides such as synthalin A demonstrated effective glucose-lowering with alpha-cell ablation in both animal models and humans with diabetes. However, further clinical use of synthalin A was curtailed due its adverse effects and the increased availability of insulin. Overall, these observations with therapeutics that directly target alpha-cells, or GCGR signaling, highlight a largely untapped potential for diabetes therapy that merits further detailed consideration. Topics: Animals; Diabetes Mellitus, Type 2; Dipeptidyl-Peptidase IV Inhibitors; Glucagon; Glucagon-Like Peptide 1; Glucose; Guanidines; Humans; Hypoglycemic Agents; Insulin; Metformin; Receptors, Glucagon | 2022 |
Short-Clustered Maltodextrin Activates Ileal Glucose-Sensing and Induces Glucagon-like Peptide 1 Secretion to Ameliorate Glucose Homeostasis in Type 2 Diabetic Mice.
Reconstructing molecular structure is an effective approach to attenuating glycemic response to starch. Previously, we rearranged α-1,4 and α-1,6-glycosidic bonds in starch molecules to produce short-clustered maltodextrin (SCMD). The present study revealed that SCMD slowly released glucose until the distal ileum. The activated ileal glucose-sensing enabled SCMD to be a potent inducer for glucagon-like peptide-1 (GLP-1). Furthermore, SCMD was found feasible to serve as the dominant dietary carbohydrate to rescue mice from diabetes. Interestingly, a mixture of normal maltodextrin and resistant dextrin (MD+RD), although it caused an attenuated glycemic response similar to that of SCMD, failed to ameliorate glucose homeostasis because it hardly induced GLP-1 secretion. The serum GLP-1 levels seen in MD+RD-fed mice (5.25 ± 1.51 pmol/L) were significantly lower than those seen in SCMD-fed mice (8.25 ± 2.01 pmol/L, Topics: Animals; Blood Glucose; Dextrins; Diabetes Mellitus, Experimental; Diabetes Mellitus, Type 2; Glucagon-Like Peptide 1; Glucagon-Like Peptide-1 Receptor; Glucose; Homeostasis; Ileum; Insulin; Mice; Polysaccharides | 2022 |
Uygur type 2 diabetes patient fecal microbiota transplantation disrupts blood glucose and bile acid levels by changing the ability of the intestinal flora to metabolize bile acids in C57BL/6 mice.
Our epidemiological study showed that the intestinal flora of Uygur T2DM patients differed from that of normal glucose-tolerant people. However, whether the Uygur T2DM fecal microbiota transplantation could reproduce the glucose metabolism disorder and the mechanism behind has not been reported. This study was designed to explore whether Uygur T2DM fecal microbiota transplantation could reproduce the glucose metabolism disorder and its mechanism.. The normal diet and high fat diet group consisted of C57BL/6 mice orally administered 0.2 mL sterile normal saline. For the MT (microbiota transplantation) intervention groups, C57BL/6 mice received oral 0.2 mL faecal microorganisms from Uygur T2DM. All mice were treated daily for 8 weeks and Blood glucose levels of mice were detected. Mice faecal DNA samples were sequenced and quantified using 16S rDNA gene sequencing. Then we detected the ability of the intestinal flora to metabolize bile acids (BAs) through co-culture of fecal bacteria and BAs. BA levels in plasma were determined by UPLC-MS. Further BA receptors and glucagon-like peptide-1 (GLP-1) expression levels were determined with RT-q PCR and western blotting.. MT impaired insulin and oral glucose tolerance. Deoxycholic acid increased and tauro-β-muricholic acid and the non-12-OH BA:12-OH BA ratio decreased in plasma. MT improved the ability of intestinal flora to produce deoxycholic acid. Besides, the vitamin D receptor in the liver and ileum and GLP-1 in the ileum decreased significantly.. Uygur T2DM fecal microbiota transplantation disrupts glucose metabolism by changing the ability of intestinal flora to metabolize BAs and the BAs/GLP-1 pathway. Topics: Animals; Bile Acids and Salts; Blood Glucose; Chromatography, Liquid; Deoxycholic Acid; Diabetes Mellitus, Type 2; DNA, Ribosomal; Fecal Microbiota Transplantation; Gastrointestinal Microbiome; Glucagon-Like Peptide 1; Humans; Insulin; Mice; Mice, Inbred C57BL; Receptors, Calcitriol; Saline Solution; Tandem Mass Spectrometry | 2022 |
Fasting and stimulated glucagon-like peptide-1 exhibit a compensatory adaptive response in diabetes and pre-diabetes states: A multi-ethnic comparative study.
Impaired secretion of glucagon-like peptide-1 (GLP-1) among Caucasians contributes to reduced incretin effect in type 2 diabetes mellitus (T2DM) patients. However, studies emanating from East Asia suggested preserved GLP-1 levels in pre-diabetes (pre-DM) and T2DM. We aimed to resolve these conflicting findings by investigating GLP-1 levels during oral glucose tolerance test (OGTT) among Malay, Chinese, and Indian ethnicities with normal glucose tolerance (NGT), pre-DM, and T2DM. The association between total GLP-1 levels, insulin resistance, and insulin sensitivity, and GLP-1 predictors were also analyzed.. A total of 174 subjects were divided into NGT (n=58), pre-DM (n=54), and T2DM (n=62). Plasma total GLP-1 concentrations were measured at 0, 30, and 120 min during a 75-g OGTT. Homeostasis model assessment of insulin resistance (HOMA-IR), HOMA of insulin sensitivity (HOMA-IS), and triglyceride-glucose index (TyG) were calculated.. Total GLP-1 levels at fasting and 30 min were significantly higher in T2DM compared with pre-DM and NGT (27.18 ± 11.56 pmol/L vs. 21.99 ± 10.16 pmol/L vs. 16.24 ± 7.79 pmol/L, p=0.001; and 50.22 ± 18.03 pmol/L vs. 41.05 ± 17.68 pmol/L vs. 31.44 ± 22.59 pmol/L, p<0.001; respectively). Ethnicity was a significant determinant of AUC. This is the first study that showed GLP-1 responses are augmented as IR states increase. Fasting and post-OGTT GLP-1 levels are raised in T2DM and pre-DM compared to that in NGT. This raises a possibility of an adaptive compensatory response that has not been reported before. Among the three ethnic groups, the Indians has the highest IR and GLP-1 levels supporting the notion of an adaptive compensatory secretion of GLP-1. Topics: Blood Glucose; Diabetes Mellitus, Type 2; Ethnicity; Fasting; Glucagon-Like Peptide 1; Humans; Incretins; Insulin; Insulin Resistance; Prediabetic State; Triglycerides | 2022 |
Comparison of the blood pressure management between sodium-glucose cotransporter 2 inhibitors and glucagon-like peptide 1 receptor agonists.
Topics: Blood Pressure; Diabetes Mellitus, Type 2; Glucagon-Like Peptide 1; Glucagon-Like Peptide-1 Receptor; Glucose; Humans; Hypoglycemic Agents; Retrospective Studies; Sodium; Sodium-Glucose Transporter 2 Inhibitors | 2022 |
Characteristics of new users of recent antidiabetic drugs in Canada and the United Kingdom.
Characteristics of patients using newer 2. We conducted a multi-database cohort study using administrative health databases from 7 Canadian provinces and the UK Clinical Practice Research Datalink. We assembled a base cohort of antidiabetic drug users between 2006 and 2018, from which we constructed 3 cohorts of new users of SGLT-2i, DPP-4i, and GLP-1 RA between 2016 and 2018.. Our cohorts included 194,070 new users of DPP-4i, 166,722 new users of SGLT-2i, and 27,719 new users of GLP-1 RA. New users of GLP-1 RA were more likely to be younger (mean ± SD: 56.7 ± 12.2 years) than new users of DPP-4i (67.8 ± 12.3 years) or SGLT-2i (64.4 ± 11.1 years). In Canada, new users of DPP-4i were more likely to have a history of coronary artery disease (22%) than new users of SGLT-2i (20%) or GLP-1 RA (15%).. Although SGLT-2i, DPP-4i, and GLP-1 RAs are recommended as 2 Topics: Canada; Cohort Studies; Diabetes Mellitus, Type 2; Dipeptidyl-Peptidase IV Inhibitors; Dipeptidyl-Peptidases and Tripeptidyl-Peptidases; Glucagon-Like Peptide 1; Glucagon-Like Peptide-1 Receptor; Glucose; Humans; Hypoglycemic Agents; Sodium; Sodium-Glucose Transporter 2 Inhibitors; Symporters; United Kingdom | 2022 |
Safe and Appropriate Use of GLP-1 RAs in Treating Adult Patients With Type 2 Diabetes and Macrovascular Disease.
Over the past decade, the type 2 diabetes (T2D) treatment landscape has evolved, allowing for more therapeutic options and the opportunity to tailor treatments to achieve patient treatment goals. In this video roundtable series, James LaSalle, DO; Lucia M. Novak, CRNP; and Lawrence Blonde, MD, MACE, FACP, discuss the mechanisms of action and clinical trial data for use of glucagon-like peptide 1 receptor agonists (GLP-1 RAs) in the safe and effective primary care management of individuals with T2D and macrovascular disease. Topics: Diabetes Mellitus, Type 2; Glucagon-Like Peptide 1; Glucagon-Like Peptide-1 Receptor; Humans; Hypoglycemic Agents | 2022 |
First-Line Therapy for Type 2 Diabetes With Sodium-Glucose Cotransporter-2 Inhibitors and Glucagon-Like Peptide-1 Receptor Agonists : A Cost-Effectiveness Study.
Guidelines recommend sodium-glucose cotransporter-2 (SGLT2) inhibitors and glucagon-like peptide-1 (GLP1) receptor agonists as second-line therapy for patients with type 2 diabetes. Expanding their use as first-line therapy has been proposed but the clinical benefits may not outweigh their costs.. To evaluate the lifetime cost-effectiveness of a strategy of first-line SGLT2 inhibitors or GLP1 receptor agonists.. Individual-level Monte Carlo-based Markov model.. Randomized trials, Centers for Disease Control and Prevention databases, RED BOOK, and the National Health and Nutrition Examination Survey.. Drug-naive U.S. patients with type 2 diabetes.. Lifetime.. Health care sector.. First-line SGLT2 inhibitors or GLP1 receptor agonists.. Life expectancy, lifetime costs, incremental cost-effectiveness ratios (ICERs).. First-line SGLT2 inhibitors and GLP1 receptor agonists had lower lifetime rates of congestive heart failure, ischemic heart disease, myocardial infarction, and stroke compared with metformin. First-line SGLT2 inhibitors cost $43 000 more and added 1.8 quality-adjusted months versus first-line metformin ($478 000 per quality-adjusted life-year [QALY]). First-line injectable GLP1 receptor agonists cost more and reduced QALYs compared with metformin.. By removing injection disutility, first-line GLP1 receptor agonists were no longer dominated (ICER, $327 000 per QALY). Oral GLP1 receptor agonists were not cost-effective (ICER, $823 000 per QALY). To be cost-effective at under $150 000 per QALY, costs for SGLT2 inhibitors would need to be under $5 per day and under $6 per day for oral GLP1 receptor agonists.. U.S. population and costs not generalizable internationally.. As first-line agents, SGLT2 inhibitors and GLP1 receptor agonists would improve type 2 diabetes outcomes, but their costs would need to fall by at least 70% to be cost-effective.. American Diabetes Association. Topics: Cost-Benefit Analysis; Diabetes Mellitus, Type 2; Glucagon-Like Peptide 1; Glucagon-Like Peptide-1 Receptor; Glucose; Humans; Hypoglycemic Agents; Metformin; Nutrition Surveys; Quality-Adjusted Life Years; Sodium; Sodium-Glucose Transporter 2; Sodium-Glucose Transporter 2 Inhibitors | 2022 |
Diabetes management in chronic kidney disease: a consensus report by the American Diabetes Association (ADA) and Kidney Disease: Improving Global Outcomes (KDIGO).
People with diabetes and chronic kidney disease (CKD) are at high risk for kidney failure, atherosclerotic cardiovascular disease, heart failure, and premature mortality. Recent clinical trials support new approaches to treat diabetes and CKD. The 2022 American Diabetes Association (ADA) Standards of Medical Care in Diabetes and the Kidney Disease: Improving Global Outcomes (KDIGO) 2022 Clinical Practice Guideline for Diabetes Management in Chronic Kidney Disease each provide evidence-based recommendations for management. A joint group of ADA and KDIGO representatives reviewed and developed a series of consensus statements to guide clinical care from the ADA and KDIGO guidelines. The published guidelines are aligned in the areas of CKD screening and diagnosis, glycemia monitoring, lifestyle therapies, treatment goals, and pharmacologic management. Recommendations include comprehensive care in which pharmacotherapy that is proven to improve kidney and cardiovascular outcomes is layered on a foundation of healthy lifestyle. Consensus statements provide specific guidance on use of renin-angiotensin system inhibitors, metformin, sodium-glucose cotransporter-2 inhibitors, glucagon-like peptide 1 receptor agonists, and a nonsteroidal mineralocorticoid receptor antagonist. These areas of consensus provide clear direction for implementation of care to improve clinical outcomes of people with diabetes and CKD. Topics: Diabetes Mellitus, Type 2; Glucagon-Like Peptide 1; Glucose; Humans; Kidney; Metformin; Mineralocorticoid Receptor Antagonists; Renal Insufficiency, Chronic; Sodium; Sodium-Glucose Transporter 2 Inhibitors; United States | 2022 |
Oral semaglutide - Rybelsus®, the first GLP-1 receptor agonist for oral use in clinical practice.
Glucagon like peptide-1 receptor agonists (GLP-1 RA) are potent antidiabetic drugs associated with significant weight loss and minimal risk of hypoglycemia. Semaglutide is a GLP-1 RA with a proven cardiovascular benefit. It is currently also available in oral form, which is especially suitable for the treatment of the initial phase of type 2 diabetes. However, it is also effective at later initiation of therapy, in different diabetic populations. The PIONEER 6 trial demonstrated cardiovascular safety of oral semaglutide, its administration was accompanied by a significant reduction in cardiovascular and overall mortality. Topics: Administration, Oral; Diabetes Mellitus, Type 2; Glucagon-Like Peptide 1; Glucagon-Like Peptide-1 Receptor; Glucagon-Like Peptides; Glycated Hemoglobin; Humans; Hypoglycemic Agents | 2022 |
Any expectations from the more powerful dulaglutide?
Dulaglutide is a frequently used GLP-1 analogue and one of the most potent antidiabetic drugs. Practical aspects of treatment with dulaglutide are presented in this article, together with new data from AWARD-11 study with higher concentrations of dulaglutide, especially the effects on diabetes control, body weight and side effects. Topics: Diabetes Mellitus, Type 2; Glucagon-Like Peptide 1; Glucagon-Like Peptide-1 Receptor; Glucagon-Like Peptides; Glycated Hemoglobin; Humans; Hypoglycemic Agents; Immunoglobulin Fc Fragments; Motivation; Recombinant Fusion Proteins | 2022 |
Real-world characteristics, modern antidiabetic treatment patterns, and comorbidities of patients with type 2 diabetes in central and Eastern Europe: retrospective cross-sectional and longitudinal evaluations in the CORDIALLY
Guidelines from 2016 onwards recommend early use of SGLT2i or GLP-1 RA for patients with type 2 diabetes (T2D) and cardiovascular disease (CVD), to reduce CV events and mortality. Many eligible patients are not treated accordingly, although data are lacking for Central and Eastern Europe (CEE).. The CORDIALLY non-interventional study evaluated the real-world characteristics, modern antidiabetic treatment patterns, and the prevalence of CVD and chronic kidney disease (CKD) in adults with T2D at nonhospital-based practices in CEE. Data were retrospectively collated by medical chart review for patients initiating empagliflozin, another SGLT2i, DPP4i, or GLP-1 RA in autumn 2018. All data were analysed cross-sectionally, except for discontinuations assessed 1 year ± 2 months after initiation.. Patients (N = 4055) were enrolled by diabetologists (56.7%), endocrinologists (40.7%), or cardiologists (2.5%). Empagliflozin (48.5%) was the most prescribed medication among SGLT2i, DPP4i, and GLP-1 RA; > 3 times more patients were prescribed empagliflozin than other SGLT2i (10 times more by cardiologists). Overall, 36.6% of patients had diagnosed CVD. Despite guidelines recommending SGLT2i or GLP-1 RA, 26.8% of patients with CVD received DPP4i. Patients initiating DPP4i were older (mean 66.4 years) than with SGLT2i (62.4 years) or GLP-1 RA (58.3 years). CKD prevalence differed by physician assessment (14.5%) or based on eGFR and UACR (27.9%). Many patients with CKD (≥ 41%) received DPP4i, despite guidelines recommending SGLT2is owing to their renal benefits. 1 year ± 2-months after initiation, 10.0% (7.9-12.3%) of patients had discontinued study medication: 23.7-45.0% due to 'financial burden of co-payment', 0-1.9% due to adverse events (no patients discontinued DPP4i due to adverse events). Treatment guidelines were 'highly relevant' for a greater proportion of cardiologists (79.4%) and endocrinologists (72.9%) than diabetologists (56.9%), and ≤ 20% of physicians consulted other physicians when choosing and discontinuing treatments.. In CORDIALLY, significant proportions of patients with T2D and CVD/CKD who initiated modern antidiabetic medication in CEE in autumn 2018 were not treated with cardioprotective T2D medications. Use of DPP4i instead of SGLT2i or GLP-1 RA may be related to lack of affordable access, the perceived safety of these medications, lack of adherence to the latest treatment guidelines, and lack of collaboration between physicians. Thus, many patients with T2D and comorbidities may develop preventable complications or die prematurely. Trial registration NCT03807440. Topics: Adult; Benzhydryl Compounds; Cardiovascular Diseases; Cross-Sectional Studies; Diabetes Mellitus, Type 2; Glucagon-Like Peptide 1; Glucagon-Like Peptide-1 Receptor; Glucosides; Humans; Hypoglycemic Agents; Renal Insufficiency, Chronic; Retrospective Studies; Sodium-Glucose Transporter 2 Inhibitors | 2022 |
[Effects of metabolic surgery on islet function in Asian patients with type 2 diabetes].
Type 2 diabetes is a high-profile global public health problem, particularly in Asia. The young age of onset, low body mass index, and early appearance of pancreatic islet dysfunction are characteristics of Asian patients with T2DM. Metabolic surgery has become the standard treatment for T2DM patients and can significantly improve T2DM through a variety of mechanisms including modulation of energy homeostasis and reduction of body fat mass. Indeed, restoration of islet function also plays an integral role in the remission of T2DM. After metabolic surgery, islet function in Asian T2DM patients has improved significantly, with proven short-term and long-term effects. In addition, islet function is an important criterion and reference for patient selection prior to metabolic surgery. The mechanism of islet function improvement after metabolic surgery is not clear, but postoperative anatomical changes in the gastrointestinal tract leading to a number of hormonal changes seem to be the potential cause, including glucagon-like peptide-1, gastric inhibitory polypeptide, peptide YY, ghrelin, and cholecystokinin. The authors analyzed the current retrospective and prospective studies on the effect of metabolic surgery on the islet function of Asian T2DM patients with a low BMI and its mechanism, summarized the clinical evidence that metabolic surgery improved islet function in Asian T2DM patients with a low BMI, and discussed its underlying mechanism. It is of great significance for realizing personalized and precise treatment of metabolic surgery and further improving its clinical benefits.. 2型糖尿病(T2DM)是当前备受瞩目的全球性公共卫生问题,在亚洲地区尤为突出。发病年龄小、体质指数(BMI)低以及早期出现胰岛功能缺陷是亚洲T2DM患者的特征。代谢手术已经成为T2DM的标准治疗手段,其可通过调节能量稳态和降低体脂质量等多种机制显著改善T2DM。事实上,胰岛功能的恢复在T2DM的缓解过程中同样发挥着不可或缺的作用。代谢手术后,亚洲T2DM患者的胰岛功能显著改善,其短期及长期效果均已获得验证。不仅如此,胰岛功能还是代谢手术前进行患者选择的重要依据和参考指标。代谢手术后胰岛功能改善的机制尚不明确,但术后胃肠道的解剖改变所致的胰高血糖素样肽-1、抑胃肽、酪酪肽、胃饥饿素及胆囊收缩素等激素的变化可能参与其中。笔者分析了目前针对代谢手术对亚洲低BMI T2DM患者胰岛功能的影响及其机制的回顾性和前瞻性研究,总结了关于代谢手术改善亚洲低BMI T2DM患者胰岛功能的临床证据,并探讨其内在机制。这对于实现代谢手术的个性化、精准化治疗,进一步提高其临床效益具有重要意义。. Topics: Bariatric Surgery; Body Mass Index; Cholecystokinin; Diabetes Mellitus, Type 2; Gastric Inhibitory Polypeptide; Ghrelin; Glucagon-Like Peptide 1; Humans; Peptide YY; Prospective Studies; Retrospective Studies; Treatment Outcome | 2022 |
Predictors of acarbose therapeutic efficacy in newly diagnosed type 2 diabetes mellitus patients in China.
Acarbose is one of the optimal drugs for patients with the first diagnosis of type 2 diabetes mellitus (T2DM). But what kind of emerging patients has the best therapeutic response to acarbose therapy has never been reported. To this end, we investigated predictors of acarbose therapeutic efficacy in newly diagnosed T2DM patients in China.. A total of 346 T2DM patients received acarbose monotherapy for 48 weeks as part of participating in the Study of Acarbose in Newly Diagnosed Patients with T2DM in China (MARCH study) from November 2008 to June 2011. Change in glycated hemoglobin (ΔHbA1c) served as a dependent variable while different baseline variables including sex, age, disease duration, weight, body mass index (BMI), systolic blood pressure (SBP), diastolic blood pressure (DBP), HbA1c, fasting plasma glucose (FPG), 2-h postprandial blood glucose (2 h PG), fasting insulin (FINS), 2-h postprandial insulin (2 h INS), early insulin secretion index (IGI), homeostasis model assessment of insulin resistance index (HOMA-IR), homeostasis model assessment of beta cell function (HOMA-B), area under the curve (AUC) of glucagon, insulin and GLP-1 were assessed as independent predictors. Step-wise multiple linear regression was employed for statistical analysis.. The results suggested that independent predictors of ΔHbA1c at 12 weeks included baseline body weight (β = - 0.012, P = 0.006), DBP (β = 0.010, P = 0.047), FPG (β = 0.111, P = 0.005) and 2 h PG (β = 0.042, P = 0.043). Independent predictors of ΔHbA1c at 24 weeks included disease duration (β = 0.040, P = 0.019) and FPG (β = 0.117, P = 0.001). Finally, independent predictor of ΔHbA1c at 48 weeks was disease duration (β = 0.038, P = 0.046).. Acarbose may be more effective in newly diagnosed T2DM patients with low FPG, low 2 h PG and obesity. The earlier T2DM is diagnosed and continuously treated with acarbose, the better the response to therapy. Topics: Acarbose; Blood Glucose; China; Diabetes Mellitus, Type 2; Glucagon; Glucagon-Like Peptide 1; Glycated Hemoglobin; Humans; Insulin; Insulin Resistance; Insulins | 2022 |
Endogenous GLP-1 levels play an important role in determining the efficacy of DPP-IV Inhibitors in both prediabetes and type 2 diabetes.
In contrast to Western population, glucagon-like peptide-1 (GLP-1) levels are preserved in some East Asian population with type 2 diabetes (T2D), explaining why dipeptidyl peptidase-IV (DPP-IV) inhibitors are more effective in East Asians. We assessed whether differences in endogenous GLP-1 levels resulted in different treatment responses to DPP-IV inhibitors in prediabetes and T2D.. A prospective 12-week study using linagliptin 5mg once daily in 50 subjects (28 prediabetes and 22 T2D) who were stratified into high versus low fasting GLP-1 groups. A 75-g oral glucose tolerance test (OGTT) was performed at week 0 and 12. Primary outcomes were changes in HbA1c, fasting and post-OGTT glucose after 12 weeks. Secondary outcomes included changes in insulin resistance and beta cell function indices.. There was a greater HbA1c reduction in subjects with high GLP-1 compared to low GLP-1 levels in both the prediabetes and T2D populations [least-squares mean (LS-mean) change of -0.33% vs. -0.11% and -1.48% vs. -0.90% respectively)]. Linagliptin significantly reduced glucose excursion by 18% in high GLP-1 compared with 8% in low GLP-1 prediabetes groups. The reduction in glucose excursion was greater in high GLP-1 compared to low GLP-1 T2D by 30% and 21% respectively. There were significant LS-mean between-group differences in fasting glucose (-0.95 mmol/L), 2-hour glucose post-OGTT (-2.4 mmol/L) in the high GLP-1 T2D group. Improvement in insulin resistance indices were seen in the high GLP-1 T2D group while high GLP-1 prediabetes group demonstrated improvement in beta cell function indices. No incidence of hypoglycemia was reported.. Linagliptin resulted in a greater HbA1c reduction in the high GLP-1 prediabetes and T2D compared to low GLP-1 groups. Endogenous GLP-1 level play an important role in determining the efficacy of DPP-IV inhibitors irrespective of the abnormal glucose tolerance states. Topics: Blood Glucose; Diabetes Mellitus, Type 2; Dipeptidyl-Peptidase IV Inhibitors; Dipeptidyl-Peptidases and Tripeptidyl-Peptidases; Glucagon-Like Peptide 1; Glycated Hemoglobin; Humans; Insulin Resistance; Linagliptin; Prediabetic State; Prospective Studies | 2022 |
Changing Patterns of Antihyperglycaemic Treatment among Patients with Type 2 Diabetes in Hungary between 2015 and 2020-Nationwide Data from a Register-Based Analysis.
Background and objectives: In the last couple of years, pharmacological management of patients with type 2 diabetes mellitus (T2DM) have been markedly renewed. The aim of this study was to analyse the changes in prescribing patterns of antidiabetic drugs for treating patients with T2DM in Hungary between 2015 and 2020. Material and Methods: In this retrospective, nationwide analysis, we used the central database of the National Health Insurance Fund. We present annual numbers and their proportion of T2DM patients with different treatment regimens. Results: In the period of 2015−2020, the number of incident cases decreased from 60,049 to 29,865, while prevalent cases increased from 682,274 to 752,367. Patients with metformin (MET) monotherapy had the highest prevalence (31% in 2020). Prevalence of insulin (INS) monotherapy continuously but slightly decreased from 29% to 27% while that of sulfonylurea (SU) monotherapy markedly decreased from 37% to 20%. Dipeptidyl peptidase (DPP-4) inhibitors remained popular in 2020 as monotherapy (5%), in dual combination with MET (12%) and in triple combination with MET and SU (5%). The prevalence of patients with sodium-glucose co-transporter-2 (SGLT-2) inhibitors increased from 1% to 4% in monotherapy, from <1% to 6% in dual combination with MET, and from <1% to 2% in triple oral combination with MET and SU or DPP-4-inhibitors. The prevalence of patients using glucagon-like peptide-1 receptor agonists (GLP-1-RAs) also increased but remained around 1−2% both in monotherapy and combinations. For initiating antihyperglycaemic treatment, MET monotherapy was the most frequently used regime in 2020 (50%), followed by monotherapy with SUs (16%) or INS (10%). After initial MET monotherapy, the incidence rates of patients with add-on GLP-1-RAs (2%, 3%, and 4%) and those of add-on SGLT-2 inhibitors (4%, 6%, and 8%) slowly increased in the subsequent 24, 48, and 72 months, respectively. Conclusions: In the period of 2015−2020, we documented important changes in trends of antihyperglycaemic therapeutic patterns in patients with T2DM which followed the new scientific recommendations but remained below our expectations regarding timing and magnitude. More efforts are warranted to implement new agents with cardiovascular/renal benefits into therapeutic management in time, in a much larger proportion of T2DM population, and without delay. Topics: Blood Glucose; Diabetes Mellitus, Type 2; Dipeptidyl-Peptidase IV Inhibitors; Dipeptidyl-Peptidases and Tripeptidyl-Peptidases; Glucagon-Like Peptide 1; Glucagon-Like Peptide-1 Receptor; Humans; Hungary; Hypoglycemic Agents; Insulin; Metformin; Retrospective Studies; Sodium; Sodium-Glucose Transporter 2 Inhibitors; Sulfonylurea Compounds; Symporters | 2022 |
The risk of major osteoporotic fractures with GLP-1 receptor agonists when compared to DPP-4 inhibitors: A Danish nationwide cohort study.
Type 2 diabetes mellitus (T2D) is associated with an increased fracture risk. There is little evidence for the effects of glucagon-like peptide 1 receptor agonists (GLP-1RA) on fracture risk in T2D. We aimed to investigate the risk of major osteoporotic fractures (MOF) for treatment with GLP-1RA compared to dipeptidyl peptidase 4 inhibitors (DPP-4i) as add-on therapies to metformin.. We conducted a population-based cohort study using Danish national health registries. Diagnoses were obtained from discharge diagnosis codes (ICD-10 and ICD-8-system) from the Danish National Patient Registry, and all redeemed drug prescriptions were obtained from the Danish National Prescription Registry (ATC classification system). Subjects treated with metformin in combination with either GLP-1RA or DPP-4i were enrolled from 2007 to 2018. Subjects were propensity-score matched 1:1 based on age, sex, and index date. MOF were defined as hip, vertebral, humerus, or forearm fractures. A Cox proportional hazards model was utilized to estimate hazard rate ratios (HR) for MOF, and survival curves were plotted using the Kaplan-Meier estimator. In addition, Aalen's Additive Hazards model was applied to examine additive rather than relative hazard effects while allowing time-varying effects.. In total, 42,816 individuals treated with either combination were identified and included. After matching, 32,266 individuals were included in the main analysis (16,133 in each group). Median follow-up times were 642 days and 529 days in the GLP-1RA and DPP-4i group, respectively. We found a crude HR of 0.89 [0.76-1.05] for MOF with GLP-1RA compared to DPP-4i. In the fully adjusted model, we obtained an unaltered HR of 0.86 [0.73-1.03]. For the case of hip fracture, we found a crude HR of 0.68 [0.49-0.96] and a similar adjusted HR. Fracture risk was lower in the GLP-1RA group when examining higher daily doses of the medications, when allowing follow-up to continue after medication change, and when examining hip fractures, specifically. Additional subgroup- and sensitivity analyses yielded results similar to the main analysis.. In our primary analysis, we did not observe a significantly different risk of MOF between treatment with GLP-1RA and DPP-4i. We conclude that GLP-1RA are safe in terms of fracture. Topics: Cohort Studies; Denmark; Diabetes Mellitus, Type 2; Dipeptidyl-Peptidase IV Inhibitors; Glucagon-Like Peptide 1; Glucagon-Like Peptide-1 Receptor; Humans; Metformin; Osteoporotic Fractures | 2022 |
Peptide Tyrosine-Tyrosine Triggers GLP-2-Mediated Intestinal Hypertrophy After Roux-en-Y Gastric Bypass.
PURPOSE : Intestinal remodeling and adaptation of the alimentary limb after Roux-en-Y gastric bypass (RYGB) play an important role in the pathophysiological events that lead to type 2 diabetes mellitus (T2DM) improvement. Intestinal absorptive loop hypertrophy and growth following surgery have been related to GLP-2 secretion by ileal L-cells. The secretion of peptide tyrosine-tyrosine (PYY) enterohormone after a meal has been proposed as a trigger for ileal secretion of GLP-1. Our aim is to determine the role of PYY as a GLP-2 secretion modulator as an adaptation result in the alimentary limb after RYGB.. We used a non-obese euglycemic rodent model. Circulating glucose, insulin, PYY, and GLP-2 were measured in the experimental and control groups. We used four groups: fasting control, Sham-operated, RYGB-operated (RYGB), and RYGB-operated and treated with BIIE0246 (RYGB + BII). BIIE0246 is a NPY2 receptor antagonist in L-cells. Intestinal glucose transporters and GLP-1 and PYY gut expression and hypertrophy were analyzed after 12 weeks of surgery.. RYGB increased PYY3-36 plasma levels in rats with or without BII treatment. A high-insulin response was observed in the RYGB group but not in the control or RYGB + BII groups. BIIE0246 treatment limited plasma GLP-2 levels. In the alimentary intestinal limb, hypertrophy and SGLT1 and GLUT1 expression appeared to be reduced after RYGB compared to controls.. The postprandial ileal PYY secretion is enhanced after RYGB. This increase mediates GLP-2 release through its binding to the Y2 receptor on L-cells. This mechanism plays a role in alimentary limb hypertrophy after surgery. Topics: Animals; Blood Glucose; Diabetes Mellitus, Type 2; Gastric Bypass; Glucagon-Like Peptide 1; Glucagon-Like Peptide 2; Glucose; Hypertrophy; Insulins; Obesity, Morbid; Rats | 2022 |
Glucagon-like peptide-1 analog liraglutide leads to multiple metabolic alterations in diet-induced obese mice.
Liraglutide, a glucagon-like peptide-1 analog, has beneficial metabolic effects in patients with type 2 diabetes and obesity. Although the high efficacy of liraglutide as an anti-diabetic and anti-obesity drug is well known, liraglutide-induced metabolic alterations in diverse tissues remain largely unexplored. Here, we report the changes in metabolic profiles induced by a 2-week subcutaneous injection of liraglutide in diet-induced obese mice fed a high-fat diet for 8 weeks. Our comprehensive metabolomic analyses of the hypothalamus, plasma, liver, and skeletal muscle showed that liraglutide intervention led to various metabolic alterations in comparison with diet-induced obese or nonobese mice. We found that liraglutide remarkably coordinated not only fatty acid metabolism in the hypothalamus and skeletal muscle but also amino acid and carbohydrate metabolism in plasma and liver. Comparative analyses of metabolite dynamics revealed that liraglutide rewired intertissue metabolic correlations. Our study points to a previously unappreciated metabolic alteration by liraglutide in several tissues, which may underlie its therapeutic effects within and across the tissues. Topics: Animals; Diabetes Mellitus, Type 2; Diet, High-Fat; Glucagon-Like Peptide 1; Hypoglycemic Agents; Liraglutide; Mice; Mice, Obese; Obesity | 2022 |
Duodenal Dual-Wavelength Photobiomodulation Improves Hyperglycemia and Hepatic Parameters with Alteration of Gut Microbiome in Type 2 Diabetes Animal Model.
Recently, the duodenum has garnered interest for its role in treating metabolic diseases, including type 2 diabetes (T2DM). Multiple sessions of external photobiomodulation (PBM) in previous animal studies suggested it resulted in improved hyperglycemia, glucose intolerance, and insulin resistance with a multifactorial mechanism of action, despite the target organ of PBM not being clearly proven. This study aimed to determine whether a single session of a duodenal light-emitting diode (LED) PBM may impact the T2DM treatment in an animal model.. Goto-Kakizaki rats as T2DM models were subjected to PBM through duodenal lumen irradiation, sham procedure, or control in 1-week pilot (630 nm, 850 nm, or 630/850 nm) and 4-week follow-up (630 nm or 630/850 nm) studies. Oral glucose tolerance tests; serum glucagon-like peptide 1 (GLP-1), glucose-dependent insulinotropic polypeptide, and insulin levels; liver chemistry and histology; and gut microbiome in the PBM, sham control, and control groups were evaluated.. In the 1-week study, duodenal dual-wavelength (D, 630/850 nm) LED PBM showed improved glucose intolerance, alkaline phosphatase and cholesterol levels, and weight gain than other groups. The D-LED PBM group in the 4-week study also showed improved hyperglycemia and liver enzyme levels, with relatively preserved pancreatic islets and increased serum insulin and GLP-1 levels. Five genera (. A single session of D-LED PBM improved hyperglycemia and hepatic parameters through the change of serum insulin, insulin resistance, insulin expression in the pancreatic β-cells, and gut microbiome in T2DM animal models. Topics: Animals; Diabetes Mellitus, Type 2; Disease Models, Animal; Duodenum; Gastrointestinal Microbiome; Glucagon-Like Peptide 1; Glucose Intolerance; Hyperglycemia; Insulin; Insulin Resistance; Liver; Rats | 2022 |
Depot-specific adipose tissue modulation by SGLT2 inhibitors and GLP1 agonists mediates their cardioprotective effects in metabolic disease.
Sodium-glucose transporter-2 inhibitors (SGLT-2i) and glucagon-like peptide 1 (GLP-1) receptor agonists are newer antidiabetic drug classes, which were recently shown to decrease cardiovascular (CV) morbidity and mortality in diabetic patients. CV benefits of these drugs could not be directly attributed to their blood glucose lowering capacity possibly implicating a pleotropic effect as a mediator of their impact on cardiovascular disease (CVD). Particularly, preclinical and clinical studies indicate that SGLT-2i(s) and GLP-1 receptor agonists are capable of differentially modulating distinct adipose pools reducing the accumulation of fat in some depots, promoting the healthy expansion of others, and/or enhancing their browning, leading to the suppression of the metabolically induced inflammatory processes. These changes are accompanied with improvements in markers of cardiac structure and injury, coronary and vascular endothelial healing and function, vascular remodeling, as well as reduction of atherogenesis. Here, through a summary of the available evidence, we bring forth our view that the observed CV benefit in response to SGLT-2i or GLP-1 agonists therapy might be driven by their ameliorative impact on adipose tissue inflammation. Topics: Adipose Tissue; Cardiovascular Diseases; Diabetes Mellitus, Type 2; Glucagon-Like Peptide 1; Glucagon-Like Peptide-1 Receptor; Humans; Hypoglycemic Agents; Metabolic Diseases; Sodium-Glucose Transporter 2 Inhibitors | 2022 |
Glucagon-like Peptide-1 receptor Tie2+ cells are essential for the cardioprotective actions of liraglutide in mice with experimental myocardial infarction.
Glucagon-like peptide-1 receptor (GLP-1R) agonists reduce the rates of major cardiovascular events, including myocardial infarction in people with type 2 diabetes, and decrease infarct size while preserving ventricular function in preclinical studies. Nevertheless, the precise cellular sites of GLP-1R expression that mediate the cardioprotective actions of GLP-1 in the setting of ischemic cardiac injury are uncertain.. Publicly available single cell RNA sequencing (scRNA-seq) datasets on mouse and human heart cells were analyzed for Glp1r/GLP1R expression. Fluorescent activated cell sorting was used to localize Glp1r expression in cell populations from the mouse heart. The importance of endothelial and hematopoietic cells for the cardioprotective response to liraglutide in the setting of acute myocardial infarction (MI) was determined by inactivating the Glp1r in Tie2+ cell populations. Cardiac gene expression profiles regulated by liraglutide were examined using RNA-seq to interrogate mouse atria and both infarcted and non-infarcted ventricular tissue after acute coronary artery ligation.. In mice, cardiac Glp1r mRNA transcripts were exclusively detected in endocardial cells by scRNA-seq. In contrast, analysis of human heart by scRNA-seq localized GLP1R mRNA transcripts to populations of atrial and ventricular cardiomyocytes. Moreover, very low levels of GIPR, GCGR and GLP2R mRNA transcripts were detected in the human heart. Cell sorting and RNA analyses detected cardiac Glp1r expression in endothelial cells (ECs) within the atria and ventricle in the ischemic and non-ischemic mouse heart. Transcriptional responses to liraglutide administration were not evident in wild type mouse ventricles following acute MI, however liraglutide differentially regulated genes important for inflammation, cardiac repair, cell proliferation, and angiogenesis in the left atrium, while reducing circulating levels of IL-6 and KC/GRO within hours of acute MI. Inactivation of the Glp1r within the Tie2+ cell expression domain encompassing ECs revealed normal cardiac structure and function, glucose homeostasis and body weight in Glp1r. These findings identify the importance of the murine Tie2+ endothelial cell GLP-1R as a target for the cardioprotective actions of GLP-1R agonists and support the importance of the atrial and ventricular endocardial GLP-1R as key sites of GLP-1 action in the ischemic mouse heart. Hitherto unexplored species-specific differences in cardiac GLP-1R expression challenge the exclusive use of mouse models for understanding the mechanisms of GLP-1 action in the normal and ischemic human heart. Topics: Animals; Atrial Fibrillation; Diabetes Mellitus, Type 2; Disease Models, Animal; Endothelial Cells; Glucagon-Like Peptide 1; Glucagon-Like Peptide-1 Receptor; Humans; Liraglutide; Mice; Myocardial Infarction; Receptor, TIE-2; RNA, Messenger | 2022 |
The prescribing pattern of sodium-glucose cotransporter-2 inhibitors and glucagon-like peptide-1 receptor agonists in patient with type two diabetes mellitus: A two-center retrospective cross-sectional study.
The use of sodium-glucose cotransporter-2 inhibitors (SGLT2i) and glucagon-like peptide-1 receptor agonists (GLP-1 RA) in patients with type 2 diabetes mellitus (T2DM) remains limited, especially in those with other compelling indications. Thus, this study aimed to describe the prescribing patterns of GLP-1-RA and SGLT2i in patients with T2DM and to determine the factors that affect the prescribing of these medications.. This multicenter retrospective cross-sectional study reviewed the electronic health records of adult patients diagnosed with T2DM who received care between January and December 2020. The patients were classified according to their compelling indications into "patients who are more likely" to benefit from SGLT2i or GLP-1 RA and "patients who are less likely" to benefit from them. They were then further categorized depending on whether these medications were prescribed.. A total of 1,220 patients were included; most were female (56.9%). SGLT2i or GLP-1 RA were preferably prescribed in only 19% of the patients for reasons including BMI ≥ 27 kg/m. The results concur with those of previous studies highlighting the underutilization of GLP-1 RA and SGLT2i in patients with T2DM but also with compelling indications. To optimize the use of GLP-1 RA and SGLT2i for their additional benefits, prescribers need to assess the benefits of using these agents in patients who would likely benefit from them, regardless of DM control. Topics: Cross-Sectional Studies; Diabetes Mellitus, Type 2; Female; Glucagon-Like Peptide 1; Glucagon-Like Peptide-1 Receptor; Glucose; Humans; Hypoglycemic Agents; Male; Retrospective Studies; Sodium; Sodium-Glucose Transporter 2 Inhibitors | 2022 |
Xenopus GLP-1-based glycopeptides as dual glucagon-like peptide 1 receptor/glucagon receptor agonists with improved in vivo stability for treating diabetes and obesity.
Peptide dual agonists toward both glucagon-like peptide 1 receptor (GLP-1R) and glucagon receptor (GCGR) are emerging as novel therapeutics for the treatment of type 2 diabetes mellitus (T2DM) patients with obesity. Our previous work identified a Xenopus GLP-1-based dual GLP-1R/GCGR agonist termed xGLP/GCG-13, which showed decent hypoglycemic and body weight lowering activity. However, the clinical utility of xGLP/GCG-13 is limited due to its short in vivo half-life. Inspired by the fact that O-GlcNAcylation of intracellular proteins leads to increased stability of secreted proteins, we rationally designed a panel of O-GlcNAcylated xGLP/GCG-13 analogs as potential long-acting GLP-1R/ GCGR dual agonists. One of the synthesized glycopeptides 1f was found to be equipotent to xGLP/GCG-13 in cell-based receptor activation assays. As expected, O-GlcNAcylation effectively improved the stability of xGLP/GCG-13 in vivo. Importantly, chronic administration of 1f potently induced body weight loss and hypoglycemic effects, improved glucose tolerance, and normalized lipid metabolism and adiposity in both db/db and diet induced obesity (DIO) mice models. These results supported the hypothesis that glycosylation is a useful strategy for improving the in vivo stability of GLP-1-based peptides and promoted the development of dual GLP-1R/GCGR agonists as antidiabetic/antiobesity drugs. Topics: Animals; Diabetes Mellitus, Type 2; Glucagon-Like Peptide 1; Glycopeptides; Hypoglycemic Agents; Mice; Obesity; Peptides; Receptors, Glucagon; Xenopus laevis | 2022 |
Ginsenoside compound K increases glucagon-like peptide-1 release and L-cell abundance in db/db mice through TGR5/YAP signaling.
Incretin impairment refers to L-cell-derived glucagon-like peptide-1 (GLP-1) deficiency, commonly observed in patients with type 2 diabetes mellitus (T2DM). Promoting the enteroendocrine L-cell population to elevate GLP-1 secretory capacity represents a potential therapeutic strategy for T2DM. It has been established that ginsenoside compound K (CK) could stimulate GLP-1 secretion; however, the underlying mechanisms remain elusive.. CK was intragastrically administered to male db/db mice for 4 weeks that subsequently underwent oral glucose tolerance testing. Serum samples were collected to measure the GLP-1 secretion, insulin level, inflammatory factors, and bile acid (BA) profiles. Ileum epithelial injury was detected by Hematoxylin and Eosin (H&E) and Masson staining. Gene markers associated with L-cell differentiation were evaluated by RT-PCR, and L-cells were labeled by Gcg via immunofluorescence assays. TGR5 and YAP expression was analyzed by immunoblotting and immunofluorescence assays.. Compound K attenuated hyperglycemia and inflammation in db/db mice and upregulated TGR5 expression by increasing lithocholic acid (LCA) and deoxycholic acid (DCA) levels in response to ileum epithelium injury. Meanwhile, fibrosis was alleviated, and the crypt architecture was restored, with increased L-cell abundance and serum GLP-1 levels. The upregulation in genes associated with L-cell differentiation promoted transformation into L-cells. Further mechanistic analyses showed that the effects of CK on the L-cell population required YAP activation, which triggered actin cytoskeleton dynamics.. Our results indicate that TGR5 could modulate the abundance of L-cells to enhance GLP-1 release through YAP-driven intestinal regeneration in db/db mice. Accordingly, CK has huge prospects for application to alleviate incretin impairment in T2DM. Topics: Animals; Diabetes Mellitus, Type 2; Glucagon-Like Peptide 1; Incretins; L Cells; Male; Mice; Mice, Inbred Strains | 2022 |
Regimen comprising GLP-1 receptor agonist and basal insulin can decrease the effect of food on glycemic variability compared to a pre-mixed insulin regimen.
Increasing evidence suggests that glucagon-like peptide 1 (GLP-1) receptor agonists (RA) can stabilize glycemic variability (GV) and interfere with eating behavior. This study compared the impact of insulin, GLP-1 RA, and dietary components on GV using professional continuous glucose monitoring (CGM).. Patients with type 2 diabetes underwent CGM before and after switching from a twice-daily pre-mixed insulin treatment regimen to a GLP-1 RA (liraglutide) plus basal insulin regimen. The dietary components were recorded and analyzed by a certified dietitian. The interactions between the medical regimen, GV indices, and nutrient components were analyzed.. Sixteen patients with type 2 diabetes were enrolled in this study. No significant differences in the diet components and total calorie intake between the two regimens were found. Under the pre-mixed insulin regimen, for increase in carbohydrate intake ratio, mean amplitude of glucose excursion (MAGE) and standard deviation (SD) increased; in contrast, under the new regimen, for increase in fat intake ratio, MAGE and SD decreased, while when the protein intake ratio increased, the coefficient of variation (CV) decreased. The impact of the food intake ratio on GV indices disappeared under the GLP-1 RA regimen. After switching to the GLP-1 RA regimen, the median MAGE, SD, and CV values decreased significantly. However, the significant difference in GV between the two regimens decreased during the daytime.. A GLP-1 RA plus basal insulin regimen can stabilize GV better than a regimen of twice-daily pre-mixed insulin, especially in the daytime, and can diminish the effect of food components on GV. Topics: Biphasic Insulins; Blood Glucose; Blood Glucose Self-Monitoring; Diabetes Mellitus, Type 2; Glucagon-Like Peptide 1; Glucagon-Like Peptide-1 Receptor; Glucose; Humans; Insulin | 2022 |
Semaglutide versus GLP-1 agonists. Effectiveness, safety, and quality of life in patients with diabetes mellitus 2. The SEVERAL study.
The cardiovascular disease is the first cause of deaths in patients with diabetes mellitus 2. The objective is to evaluate and compare the weight loss in patients with diabetes treated with the different GLP-1 receptor agonists for the first time. Secondary endpoints are glycosylated hemoglobin reduction, changes in quality of life and physical activity and the safety of these drugs.. It is a postauthorization, multicenter, non-randomized and prospective study. 360 Patients that will start treatment for the first time with GLP-1 receptor agonists will be recruited in 10 centers in the National Health System for a period of 6 months and 44 weeks of follow-up. The primary endpoint will be weight loss achieved with the different GLP-1 receptor agonists and the secondary endpoint will be glycosylated hemoglobin reduction, changes in the quality of life through the EuroQol‑5D and changes physical activity through the SF-12 questionnaire, and also the safety of these drugs. The estimate recruitment period will be 6 months, from 1 December 2021 to 1 May 2022. The follow up will finish in December 2022.. The SEVERAL study will try to provide information about weight loss efficacy, changes in quality of life, physical activity and safety of the GLP-1 receptor agonists in patients with diabetes that start treatment with these drugs in the real life. This study try to compare different GLP-1 receptor gonists in terms of effectiveness and safety for a better posterior election when these drugs are used in patients with diabetes mellitus 2 and obesity.. La enfermedad cardiovascular es la causa principal de muerte en pacientes con diabetes mellitus 2. El objetivo principal es evaluar y comparar prospectivamente la pérdida de peso en pacientes con diabetes mellitus 2 tratados por primera vez con los diferentes análogos de la GLP-1. Como variables secundarias se estudiará reducción de la hemoglobina glicosilada, cambios en calidad de vida y actividad física y la seguridad de estos fármacos.Método: Se trata de un estudio postautorización, multicéntrico, no leatorizado de seguimiento prospectivo. Se reclutarán 360 pacientes que inicien tratamiento por primera vez con análogos de la GLP1 en 10 centros del sistema público durante un período de 6 meses y un seguimiento de 44 semanas. La variable principal será la pérdida de peso con los diferentes análogos de la GLP1 y como variable secundaria se valorarán: reducción de hemoglobina glicosilada, cambios en la calidad de vida y actividad física a través del EuroQol-5D y SF-12 y seguridad. Se ha estimadoun período de reclutamiento de 6 meses, desde el 1 de Diciembre 2021 al 1 de Mayo 2022. El seguimiento finalizará en Diciembre de 2022.Discusión: El estudio intentará aportar información sobre la efectividad en pérdida de peso, cambios en calidad de vida, actividad física y seguridad de los análogos de la GLP1 en pacientes con diabetes mellitus 2 que inician tratamiento con estos fármacos en la vida real. Este trabajo pretende comparar los diferentes análogos de la GLP1 en términos de eficacia y eguridad para una posterior mejor elección en la prescripción de estos fármacos en pacientes con diabetes mellitus 2 y obesidad. Topics: Diabetes Mellitus, Type 2; Glucagon-Like Peptide 1; Glucagon-Like Peptide-1 Receptor; Glycated Hemoglobin; Humans; Hypoglycemic Agents; Prospective Studies; Quality of Life | 2022 |
Voglibose Regulates the Secretion of GLP-1 Accompanied by Amelioration of Ileal Inflammatory Damage and Endoplasmic Reticulum Stress in Diabetic KKAy Mice.
Voglibose is an α-glycosidase inhibitor that improves postprandial hyperglycemia and increases glucagon-like peptide-1 (GLP-1) secretion in patients with type 2 diabetes. Recently, there has been increasing interest in the anti-inflammatory effects of voglibose on the intestine, but the underlying mechanism is not clear. This study evaluated the effects and mechanisms of voglibose on glycemic control and intestinal inflammation. Type 2 diabetic KKAy mice were treated with voglibose (1 mg/kg) by oral gavage once daily. After 8 weeks, glucose metabolism, levels of short-chain fatty acids (SCFAs), systematic inflammatory factors, intestinal integrity and inflammation were evaluated using hematoxylin and eosin staining, immunohistochemistry, immunofluorescence and Western blot analysis. Voglibose ameliorated glucose metabolism by enhancing basal- and glucose-dependent GLP-1 secretion. Several beneficial SCFAs, such as acetic acid and propionic acid, were increased by voglibose in the fecal sample. Additionally, voglibose notably decreased the proportion of pro-inflammatory macrophages and the expression of nuclear factor kappa B but increased the expression of tight junction proteins in the ileum, thus markedly improving intestinal inflammatory damage and reducing the systematic inflammatory factors. Ileal genomics and protein validation suggested that voglibose attenuated inositol-requiring protein 1α-X-box binding protein 1-mediated endoplasmic reticulum stress (ERS). Together, these results showed that voglibose enhanced the secretion of GLP-1, which contributed to the glycemic control in KKAy mice at least in part by regulating intestinal inflammation and the expression of ERS factors. Topics: Animals; Diabetes Mellitus, Type 2; Glucagon-Like Peptide 1; Glucose; Ileum; Inositol; Mice | 2022 |
Elevated Glucagon-like Peptide-1 Receptor Level in the Paraventricular Hypothalamic Nucleus of Type 2 Diabetes Mellitus Patients.
Glucagon-like peptide-1 (GLP-1) receptor (GLP-1R) agonists have been approved for the treatment of type 2 diabetes mellitus (T2DM); however, the brain actions of these drugs are not properly established. We used post mortem microdissected human hypothalamic samples for RT-qPCR and Western blotting. For in situ hybridization histochemistry and immunolabelling, parallel cryosections were prepared from the hypothalamus. We developed in situ hybridization probes for human GLP-1R and oxytocin. In addition, GLP-1 and oxytocin were visualized by immunohistochemistry. Radioactive in situ hybridization histochemistry revealed abundant GLP-1R labelling in the human paraventricular hypothalamic nucleus (PVN), particularly in its magnocellular subdivision (PVNmc). Quantitative analysis of the mRNA signal demonstrated increased GLP-1R expression in the PVNmc in post mortem hypothalamic samples from T2DM subjects as compared to controls, while there was no difference in the expression level of GLP-1R in the other subdivisions of the PVN, the hypothalamic dorsomedial and infundibular nuclei. Our results in the PVN were confirmed by RT-qPCR. Furthermore, we demonstrated by Western blot technique that the GLP-1R protein level was also elevated in the PVN of T2DM patients. GLP-1 fibre terminals were also observed in the PVNmc closely apposing oxytocin neurons using immunohistochemistry. The data suggest that GLP-1 activates GLP-1Rs in the PVNmc and that GLP-1R is elevated in T2DM patients, which may be related to the dysregulation of feeding behaviour and glucose homeostasis in T2DM. Topics: Diabetes Mellitus, Type 2; Glucagon-Like Peptide 1; Glucagon-Like Peptide-1 Receptor; Humans; Oxytocin; Paraventricular Hypothalamic Nucleus | 2022 |
Association between different GLP-1 receptor agonists and gastrointestinal adverse reactions: A real-world disproportionality study based on FDA adverse event reporting system database.
Glucagon-like peptide-1 receptor agonists (GLP-1 RAs) have significantly improved clinical effects on glycemic control. However, real-world data concerning the difference in gastrointestinal adverse events (AEs) among different GLP-1 RAs are still lacking. Our study aimed to characterize and compare gastrointestinal AEs among different marketed GLP-1 RAs (exenatide, liraglutide, dulaglutide, lixisenatide, and semaglutide) based on real-world data.. Disproportionality analysis was used to evaluate the association between GLP-1 RAs and gastrointestinal adverse events. Data were extracted from the US FDA Adverse Event Reporting System (FAERS) database between January 2018 and September 2022. Clinical characteristics, the time-to-onset, and the severe proportion of GLP-1 RAs-associated gastrointestinal AEs were further analyzed.. A total of 21,281 reports of gastrointestinal toxicity were analyzed out of 81,752 adverse event reports, and the median age of the included patients was 62 (interquartile range [IQR] 54-70) years old. Overall GLP-1 RAs were associated with increased risk of gastrointestinal system disorders (ROR, 1.46; 95% CI, 1.44-1.49), which were further attributed to liraglutide (ROR, 2.39; 95% CI, 2.28-2.51), dulaglutide (ROR, 1.39; 95% CI, 1.36-1.42), and semaglutide (ROR, 3.00; 95% CI, 2.89-3.11). Adverse events uncovered in the labels included gastroesophageal reflux disease, gastritis, bezoar, breath odor, intra-abdominal hematoma, etc. Furthermore, it was observed that semaglutide had the greatest risk of nausea (ROR, 7.41; 95% CI, 7.10-7.74), diarrhea (ROR, 3.55; 95% CI, 3.35-3.77), vomiting (ROR, 6.67; 95% CI, 6.32-7.05), and constipation (ROR, 6.17; 95% CI, 5.72-6.66); liraglutide had the greatest risk of abdominal pain upper (ROR, 4.63; 95% CI, 4.12-5.21) and pancreatitis (ROR, 32.67; 95% CI, 29.44-36.25). Most gastrointestinal AEs tended to occur within one month. Liraglutide had the highest severe rate of gastrointestinal AEs (23.31%), while dulaglutide had the lowest, with a severe rate of 12.29%.. GLP-1 RA were significantly associated with gastrointestinal AEs, and the association was further attributed to liraglutide, dulaglutide, and semaglutide. In addition, semaglutide had the greatest risk of nausea, diarrhea, vomiting, constipation, and pancreatitis, while liraglutide had the greatest risk of upper abdominal pain. Our study provided valuable evidence for selecting appropriate GLP-1 RAs to avoid the occurrence of GLP-1 RA-induced gastrointestinal AEs. Topics: Abdominal Pain; Adverse Drug Reaction Reporting Systems; Aged; Constipation; Databases, Factual; Diabetes Mellitus, Type 2; Diarrhea; Gastrointestinal Diseases; Glucagon-Like Peptide 1; Glucagon-Like Peptide-1 Receptor; Humans; Hypoglycemic Agents; Liraglutide; Middle Aged; Nausea; Pancreatitis; United States; United States Food and Drug Administration; Vomiting | 2022 |
Obesity in women's life: role of GLP-1 agonists.
Topics: Diabetes Mellitus, Type 2; Female; Glucagon-Like Peptide 1; Humans; Hypoglycemic Agents; Obesity | 2022 |
Incretin-based therapy of metabolic disease.
Recent studies show that incretin hormone analogues effectively control blood glucose while producing major weight losses and reducing the risk of all-cause mortality, myocardial infarction, stroke and kidney function impairment. Furthermore, the risk of dementia and cognitive impairment is reduced. A monomolecular coagonist (tirzepatide) of receptors for both incretin hormones (glucagon-like peptide-1 and glucose-dependent insulinotropic polypeptide) produced HbA1c values below 5.7% in 50% of the treated patients and weight losses exceeding 20% in obese individuals. These new agents will radically change our approach to the treatment of T2DM and obesity alike. Topics: Blood Glucose; Diabetes Mellitus, Type 2; Gastric Inhibitory Polypeptide; Glucagon-Like Peptide 1; Humans; Incretins; Metabolic Diseases; Obesity; Weight Loss | 2022 |
Acute gastric dilation associated with the use of semaglutide, a GLP-1 analogue.
Topics: Diabetes Mellitus, Type 2; Gastric Dilatation; Glucagon-Like Peptide 1; Glucagon-Like Peptides; Humans; Hypoglycemic Agents | 2022 |
A High-Fat Diet Increases Activation of the Glucagon-Like Peptide-1-Producing Neurons in the Nucleus Tractus Solitarii: an Effect that is Partially Reversed by Drugs Normalizing Glycemia.
Glucagon-like peptide-1 (GLP-1) is a peripheral incretin and centrally active peptide produced in the intestine and nucleus tractus solitarii (NTS), respectively. GLP-1 not only regulates metabolism but also improves cognition and is neuroprotective. While intestinal GLP-1-producing cells have been well characterized, less is known about GLP-1-producing neurons in NTS. We hypothesized that obesity-induced type 2 diabetes (T2D) impairs the function of NTS GLP-1-producing neurons and glycemia normalization counteracts this effect. We used immunohistochemistry/quantitative microscopy to investigate the number, potential atrophy, and activation (cFos-expression based) of NTS GLP-1-producing neurons, in non-diabetic versus obese/T2D mice (after 12 months of high-fat diet). NTS neuroinflammation was also assessed. The same parameters were quantified in obese/T2D mice treated from month 9 to 12 with two unrelated anti-hyperglycemic drugs: the dipeptidyl peptidase-4 inhibitor linagliptin and the sulfonylurea glimepiride. We show no effect of T2D on the number and volume but increased activation of NTS GLP-1-producing neurons. This effect was partially normalized by both anti-diabetic treatments, concurrent with decreased neuroinflammation. Increased activation of NTS GLP-1-producing neurons could represent an aberrant metabolic demand in T2D/obesity, attenuated by glycemia normalization. Whether this effect represents a pathophysiological process preceding GLP-1 signaling impairment in the CNS, remains to be investigated. Topics: Animals; Blood Glucose; Diabetes Mellitus, Type 2; Diet, High-Fat; Glucagon-Like Peptide 1; Mice; Neurons; Obesity; Solitary Nucleus | 2022 |
The leaves and fruits of Topics: Diabetes Mellitus, Type 2; Dipeptidyl-Peptidase IV Inhibitors; Gastric Inhibitory Polypeptide; Glucagon-Like Peptide 1; Humans; Hypoglycemic Agents; Molecular Docking Simulation; Molecular Dynamics Simulation; Phytochemicals | 2022 |
Signaling profiles in HEK 293T cells co-expressing GLP-1 and GIP receptors.
Glucagon-like peptide-1 (GLP-1) and glucose-dependent insulinotropic polypeptide (GIP) are regarded as 'incretins' working closely to regulate glucose homeostasis. Unimolecular dual and triple agonists of GLP-1R and GIPR have shown remarkable clinical benefits in treating type 2 diabetes. However, their pharmacological characterization is usually carried out in a single receptor-expressing system. In the present study we constructed a co-expression system of both GLP-1R and GIPR to study the signaling profiles elicited by mono, dual and triple agonists. We show that when the two receptors were co-expressed in HEK 293T cells with comparable receptor ratio to pancreatic cancer cells, GIP predominately induced cAMP accumulation while GLP-1 was biased towards β-arrestin 2 recruitment. The presence of GIPR negatively impacted GLP-1R-mediated cAMP and β-arrestin 2 responses. While sharing some common modulating features, dual agonists (peptide 19 and LY3298176) and a triple agonist displayed differentiated signaling profiles as well as negative impact on the heteromerization that may help interpret their superior clinical efficacies. Topics: beta-Arrestin 2; Diabetes Mellitus, Type 2; Gastric Inhibitory Polypeptide; Glucagon-Like Peptide 1; Glucagon-Like Peptide-1 Receptor; Glucose; HEK293 Cells; Humans | 2022 |
Basal insulin plus GLP-1 RA or SGLT2 inhibitor was noninferior to basal-bolus insulin intensification for HbA
Giugliano D, Longo M, Caruso P, et al. Topics: Blood Glucose; Diabetes Mellitus, Type 2; Glucagon-Like Peptide 1; Humans; Hypoglycemic Agents; Insulin; Sodium-Glucose Transporter 2 Inhibitors | 2021 |
Circulating microRNAs Signature for Predicting Response to GLP1-RA Therapy in Type 2 Diabetic Patients: A Pilot Study.
Type 2 diabetes (T2D) represents one of the major health issues of this century. Despite the availability of an increasing number of anti-hyperglycemic drugs, a significant proportion of patients are inadequately controlled, thus highlighting the need for novel biomarkers to guide treatment selection. MicroRNAs (miRNAs) are small non-coding RNAs, proposed as useful diagnostic/prognostic markers. The aim of our study was to identify a miRNA signature occurring in responders to glucagon-like peptide 1 receptor agonists (GLP1-RA) therapy. We investigated the expression profile of eight T2D-associated circulating miRNAs in 26 prospectively evaluated diabetic patients in whom GLP1-RA was added to metformin. As expected, GLP1-RA treatment induced significant reductions of HbA1c and body weight, both after 6 and 12 months of therapy. Of note, baseline expression levels of the selected miRNAs revealed two distinct patient clusters: "high expressing" and "low expressing". Interestingly, a significantly higher percentage of patients in the high expression group reached the glycemic target after 12 months of treatment. Our findings suggest that the evaluation of miRNA expression could be used to predict the likelihood of an early treatment response to GLP1-RA and to select patients in whom to start such treatment, paving the way to a personalized medicine approach. Topics: Adult; Biomarkers, Pharmacological; Blood Glucose; Circulating MicroRNA; Diabetes Mellitus, Type 2; Female; Gene Expression; Gene Expression Profiling; Glucagon-Like Peptide 1; Glucagon-Like Peptide-1 Receptor; Glucose; Humans; Hypoglycemic Agents; Male; MicroRNAs; Middle Aged; Pilot Projects; Transcriptome | 2021 |
GLP-1 Analogs Are Superior in Mediating Weight Loss But Not Glycemic Control in Diabetic Patients on Antidepressant Medications: A Retrospective Cohort Study.
Topics: Antidepressive Agents; Diabetes Mellitus, Type 2; Female; Glucagon-Like Peptide 1; Humans; Prospective Studies; Retrospective Studies; Weight Loss | 2021 |
Glucagon-like peptide-1 serum levels are associated with weight gain in patients treated with clozapine.
Metabolic syndrome and related cardiovascular risk factors are well-known comorbidities among patients with schizophrenia. Biomarkers of these antipsychotic-associated metabolic adverse effects and antipsychotic-induced weight gain are needed. Glucagon-like peptide-1 (GLP-1) is involved in insulin secretion, regulation of satiety, inhibition of food intake, and inhibition of gastric emptying. GLP-1 also induces reduction in body weight. Visfatin/ NAMPT/ PBEF is an adipocytokine secreted by several cells and tissues. Increased plasma visfatin levels have been associated with overweight/obesity, type 2 diabetes mellitus, insulin resistance, metabolic syndrome and cardiovascular diseases, low grade inflammation, and proinflammatory markers. Associations between antipsychotic-induced weight gain and serum visfatin and GLP-1 levels have been little studied in patients with schizophrenia. The aim of the present study was to test the possible role of serum GLP-1 and visfatin level alterations as markers of weight gain in association with metabolic and inflammatory markers in 190 patients (109 male, 81 female) with schizophrenia on clozapine treatment. High serum levels of GLP-1 correlated significantly with higher levels of visfatin, leptin, insulin, HOMA-IR, higher BMI, and weight change among men. Associations between serum visfatin levels and BMI or weight change were not found in the present patients. Serum GLP-1 level seems to be a marker of metabolic risk factors among men with schizophrenia on clozapine treatment. Female patients may be more sensitive to suppressive effects of clozapine on GLP-1 secretion. Patients on clozapine would benefit from GLP-1 agonists as preventive treatment. Topics: Clozapine; Diabetes Mellitus, Type 2; Female; Glucagon-Like Peptide 1; Humans; Male; Obesity; Weight Gain | 2021 |
The new dual gastric inhibitory peptide/glucagon-like peptide 1 agonist tirzepatide in type 2 diabetes: Is the future bright?
Tirzepatide is a dual gastric inhibitory peptide/glucagon-like peptide 1 (GIP/GLP-1) receptor agonist formulated as a synthetic linear peptide, based on the native GIP sequence. It has a prolonged half-life of 5 days, which enables once-weekly dosing. Studies have hitherto demonstrated its superiority in achieving optimal glycaemic control and body weight management, as compared with various agents used in the treatment of type 2 diabetes mellitus (T2DM), including GLP-1 receptor agonists. Thus, it is expected to enrich our therapeutic armamentarium in T2DM. However, further experience, notably longer follow-up data and information on cardiovascular effects, is still needed. Topics: Diabetes Mellitus, Type 2; Gastric Inhibitory Polypeptide; Glucagon-Like Peptide 1; Glucagon-Like Peptide-1 Receptor; Humans; Hypoglycemic Agents | 2021 |
Comment on Rosenstock et al. Impact of a Weekly Glucagon-Like Peptide 1 Receptor Agonist, Albiglutide, on Glycemic Control and on Reducing Prandial Insulin Use in Type 2 Diabetes Inadequately Controlled on Multiple Insulin Therapy: A Randomized Trial. Dia
Topics: Diabetes Mellitus, Type 2; Glucagon-Like Peptide 1; Glycemic Control; Humans; Hypoglycemic Agents; Insulin | 2021 |
Response to Comment on Rosenstock et al. Impact of a Weekly Glucagon-Like Peptide 1 Receptor Agonist, Albiglutide, on Glycemic Control and on Reducing Prandial Insulin Use in Type 2 Diabetes Inadequately Controlled on Multiple Insulin Therapy: A Randomize
Topics: Diabetes Mellitus, Type 2; Glucagon-Like Peptide 1; Glycemic Control; Humans; Hypoglycemic Agents; Insulin | 2021 |
Impact of the different biliopancreatic limb length on diabetes and incretin hormone secretion following distal gastrectomy in gastric cancer patients.
The present study aimed to investigate changes in glucose metabolism and incretin hormone response following longer intestinal bypass reconstruction after distal gastrectomy (DG) in low BMI patients with gastric cancer and type 2 diabetes. A total of 20 patients were prospectively recruited and underwent either conventional Billroth I (BI), Billroth II with long-biliopancreatic limb (BII), or Roux-en-Y anastomosis with long-Roux limb (RY) after DG. A 75g-oral glucose tolerance test (OGTT) was given preoperatively; and at 5 days, 3 months, and 6 months postoperatively. Serum glucose, insulin, glucagon, glucagon-like peptide-1 (GLP-1), and glucose-dependent insulinotropic polypeptide (GIP) were serially measured. At 6 months after surgery, complete diabetes remission was achieved in 57.1% of the BII group but in no patients in the other two groups (p = 0.018). BII group showed a significant reduction in glucose concentration during OGTT at 6 months in contrast to the other 2 groups. In the BII group, a significant increase in GLP-1 secretion was observed after surgery but not maintained at 6 months, while postoperative hyperglucagonemia was alleviated along with a reduction in GIP. BII gastrojejunostomy with long biliopancreatic limb achieved better diabetes control with favorable incretin response after DG compared to BI or RY reconstruction. Topics: Aged; Anastomosis, Roux-en-Y; Blood Glucose; Body Mass Index; Diabetes Mellitus, Type 2; Female; Follow-Up Studies; Gastrectomy; Gastric Bypass; Gastric Inhibitory Polypeptide; Glucagon; Glucagon-Like Peptide 1; Glucose Tolerance Test; Humans; Incretins; Insulin; Male; Middle Aged; Postoperative Period; Prospective Studies; Stomach Neoplasms; Treatment Outcome | 2021 |
Danning tablets might improve glucose and lipid metabolism in asymptomatic T2MD patients after cholecystectomy: A cohort study.
Considering the role of bile acids in glucose metabolism and the effect of farnesoid X receptor agonists on bile acids, we investigated the possible effect of Danning tablets (DNTs), a type of farnesoid X receptor agonist, on glucose and lipid metabolism in asymptomatic type 2 diabetes mellitus (T2DM) patients.A series of asymptomatic T2DM patients who underwent cholecystectomy at least 2 years prior and were regularly followed up in our hospital were included in our analysis. According to their choice, they were divided into 2 groups: the DNT group and the control group. Demographic data, body weight, food intake, effects on diabetes control, and biomedical variables were collected.After propensity score matching, a total of 64 T2DM patients (41 males and 23 females) were included in the analysis. The amount of daily food intake (kcals) and diet composition were little changed 6-months after DNT administration (P = .612). However, the average fasting glucose level of the DNT group decreased from 9.5 ± 1.4 mmol/L to 8.3 ± 1.6 mmol/L (P < .001), and the level of hemoglobin A1c decreased from 8.3 ± 1.1% to 7.6 ± 1.0% (P = .001). The total cholesterol level (P = .024) and low-density lipoprotein cholesterol level (P = .034) decreased significantly (P = .018). Moreover, the average level of total bile acids decreased from 6.05 ± 2.60 μmol/L to 5.10 ± 1.83 μmol/L in the DNT group (P = .037), and the level of glucagon-like peptide-1 significantly increased from 6.93 ± 4.94 pmol/L to 11.25 ± 5.88 pmol/L (P < .001).The results of our study show that DNT intake improved glucose and lipid metabolism and increased the level of glucagon-like peptide-1.Trial registration: registered in Chinese Clinical Trial Registry (No. ChiCTR1900027823). Topics: Aged; Bile Acids and Salts; Blood Glucose; Cholecystectomy; Cholesterol; Cohort Studies; Diabetes Mellitus, Type 2; Female; Glucagon-Like Peptide 1; Glucose; Humans; Lipid Metabolism; Male; Middle Aged; Receptors, Cytoplasmic and Nuclear; Tablets | 2021 |
Boosting GLP-1 by Natural Products.
The prevalence of diabetes mellitus is growing rapidly. Diabetes is the underlying cause of many metabolic and tissue dysfunctions, and, therefore, many therapeutic agents have been developed to regulate the glycemic profile. Glucagon-like peptide-1 (GLP-1) receptor agonists are a newly developed class of antidiabetic drugs that have potent hypoglycemic effects via several molecular pathways. In addition to synthetic GLP-1 receptor agonists, some evidence suggests that natural products may have modulatory effects on GLP-1 expression and secretion. In the current study, we conclude that certain herbal-based constituents, such as berberine, tea, curcumin, cinnamon, wheat, soybean, resveratrol, and gardenia, can exert an influence on GLP-1 release. Topics: Biological Products; Diabetes Mellitus, Type 2; Glucagon-Like Peptide 1; Glucagon-Like Peptide-1 Receptor; Humans; Hypoglycemic Agents | 2021 |
Racial, Ethnic, and Socioeconomic Inequities in Glucagon-Like Peptide-1 Receptor Agonist Use Among Patients With Diabetes in the US.
Randomized clinical trials have shown that glucagon-like peptide-1 receptor agonists (GLP-1 RAs) cause significant weight loss and reduce cardiovascular events in patients with type 2 diabetes (T2D). Black patients have a disproportionate burden of obesity and cardiovascular disease and have a higher rate of cardiovascular-related mortality. Racial and ethnic disparities in health outcomes are largely attributable to the pervasiveness of structural racism, and patients who are marginalized by racism have less access to novel therapeutics.. To evaluate GLP-1 RA uptake among a commercially insured population of patients with T2D; identify associations of race, ethnicity, sex, and socioeconomic status with GLP-1 RA use; and specifically examine its use among the subgroup of patients with atherosclerotic cardiovascular disease (ASCVD) because of the known benefit of GLP-1 RA use for this population.. This was a retrospective cohort analysis using data from OptumInsight Clinformatics Data Mart of commercially insured adult patients with T2D (with or without ASCVD) in the US. Data from October 1, 2015, to June 31, 2019, were included, and the analyses were performed in July 2020. We estimated multivariable logistic regression models to identify the association of race, ethnicity, sex, and socioeconomic status with GLP-1 RA use.. A prescription for a GLP-1 RA.. Of the 1 180 260 patients with T2D (median [IQR] age, 69 [59-76] years; 50.3% female; 57.7% White), 90 934 (7.7%) were treated with GLP-1 RA during the study period. From 2015 to 2019, the percentage of T2D patients treated with an GLP-1 RA increased from 3.2% to 10.7%. Among patients with T2D and ASCVD, use also increased but remained low (2.8%-9.4%). In multivariable analyses, lower rates of GLP-1 RA use were found among Asian (aOR, 0.59; 95% CI, 0.56-0.62), Black (adjusted odds ratio [aOR] 0.81; 95% CI, 0.79-0.83), and Hispanic (aOR, 0.91; 95% CI, 0.88-0.93) patients with T2D. Female sex (aOR, 1.22; 95% CI, 1.20-1.24) and higher zip code-linked median household incomes (>$100 000 [OR, 1.13; 95% CI, 1.11-1.16] and $50 000-$99 999 [OR, 1.07; 95% CI, 1.05-1.09] vs <$50 000) were associated with higher GLP-1 RA use. These results were similar to those found among patients with ASCVD.. In this cohort study of US patients with T2D, GLP-1 RA use increased, but remained low overall for treatment of T2D, particularly among patients with ASCVD who are likely to derive the most benefit. Asian, Black, and Hispanic patients and those with low income were less likely to receive treatment with a GLP-1 RA. Strategies to lower barriers to GLP-1 RA use, such as lower cost, are needed to prevent the widening of well-documented inequities in cardiovascular disease outcomes in the US. Topics: Adult; Aged; Cardiovascular Diseases; Cohort Studies; Diabetes Mellitus, Type 2; Ethnicity; Female; Glucagon-Like Peptide 1; Glucagon-Like Peptide-1 Receptor; Humans; Male; Retrospective Studies; Socioeconomic Factors | 2021 |
[Prognostic factors for the carbohydrate metabolism normalization in patients with type 2 diabetes mellitus and obesity using liraglutide 3.0 mg per day].
Glucagon-like peptide-1 receptor agonists (GLP-1 RA) are innovative drugs that effectively reduce glycemic levels and overweight in patients with type 2 diabetes mellitus (T2DM). However, the criteria for predicting the hypoglycemic effect of this group of drugs have not been practically defined.. To assess the factors contributing to the achievement the glycemia normalization in patients with diabetes mellitus and obesity by adding to antihyperglycemic therapy (AT) a drug from the GLP-1 RA group liraglutide 3.0 mg per day.. A single-center, prospective, non-randomized study was provided. The objects of the study were patients with T2DM and obesity (n=22). Liraglutide 3.0 mg per day was added to the current AT of patients. Initially, the parameters of carbohydrate metabolism, hormones of the incretin system on an empty stomach and during the mixed-meal test, insulin resistance using the euglycemic hyperinsulinemic clamp test, and body composition were studied. After 9 months of therapy, all studies were repeated and a search for possible predictors of the carbohydrate metabolism normalization was made.. The body mass index of patients decreased from 42.4 [37.7; 45.0] to 35.9 [33.0; 40.9] kg/m2. Fasting blood glucose and glycated hemoglobin levels decreased from 9.02 [7.40; 11.37] mmol/L and 7.85 [7.43; 8.65]% up to 5.90 [5.12; 6.18] mmol/L and 6.40 [5.90; 6.60]%, respectively. 14 (63.6%) patients reached normoglycemia. Insulin resistance according to the clamp test did not change over the study. Basal concentrations of oxyntomodulin, glycentin and the area under the GLP-1, oxyntomodulin, glycentin curve significantly decreased 9 months after liraglutide administration. The prognostic marker of the achievement of normoglycemia during therapy with liraglutide 3.0 mg/day is the level of endogenous GLP-15.5 pmol/L before the appointment of arGPP-1 therapy.. The concentration of endogenous GLP-1 before the appointment of liraglutide therapy at a dose of 3.0 mg per day can be used for prediction the drug hypoglycemic effect and achieving normoglycemia possibility.. Актуальность. Агонисты рецепторов глюкагоноподобного пептида-1 (арГПП-1) являются инновационными препаратами, эффективно снижающими уровень гликемии и избыточный вес у пациентов с сахарным диабетом 2-го типа (СД 2). Однако практически не определены критерии, позволяющие прогнозировать сахароснижающий эффект этой группы препаратов. Цель. Оценить факторы, способствующие достижению нормализации гликемии у пациентов с СД 2 и ожирением при добавлении к сахароснижающей терапии (СТ) препарата из группы арГПП-1 лираглутида 3,0 мг/сут. Материалы и методы. Проведено одноцентровое проспективное нерандомизированное исследование. Объектами исследования выступили пациенты с СД 2 и ожирением (n=22). К текущей СТ пациентов был добавлен лираглутид 3,0 мг/сут. Исходно исследованы показатели углеводного обмена, гормонов инкретиновой системы натощак и в течение теста со смешанной пищей, инсулинорезистентности с помощью эугликемического гиперинсулинемического клэмп-теста, композитного состава тела. Через 9 мес терапии повторены все исследования и проведен поиск возможных предикторов нормализации углеводного обмена. Результаты. Индекс массы тела пациентов снизился с 42,4 [37,7; 45,0] до 35,9 [33,0; 40,9] кг/м2. Уровни глюкозы крови натощак и гликированного гемоглобина снизились с 9,02 [7,40; 11,37] ммоль/л и 7,85 [7,43; 8,65]% до 5,90 [5,12; 6,18] ммоль/л и 6,40 [5,90; 6,60]% соответственно. Нормогликемии достигли 14 (63,6%) пациентов. Инсулинорезистентность, согласно клэмп-тесту, не изменилась на протяжении 9 мес исследования. Базальные концентрации оксинтомодулина, глицентина и площади под кривой ГПП-1, оксинтомодулина, глицентина значимо снизились через 9 мес после назначения лираглутида. Прогностическим маркером достижения нормогликемии при терапии лираглутидом 3,0 мг/сут является уровень эндогенного ГПП-15,5 пмоль/л до назначения терапии арГПП-1. Заключение. Концентрация эндогенного ГПП-1 до назначения терапии лираглутидом в дозе 3,0 мг/сут может быть использована для прогнозирования сахароснижающего эффекта препарата и возможности достижения нормогликемии. Topics: Blood Glucose; Carbohydrate Metabolism; Diabetes Mellitus, Type 2; Glucagon-Like Peptide 1; Glucagon-Like Peptide-1 Receptor; Glycated Hemoglobin; Humans; Hypoglycemic Agents; Incretins; Insulin Resistance; Liraglutide; Obesity; Oxyntomodulin; Prognosis; Prospective Studies | 2021 |
Display of quintuple glucagon-like peptide 1 (28-36) nonapeptide on Bacillus subtilis spore for oral administration in the treatment of type 2 diabetes.
To develop an oral delivery system of glucagon-like peptide 1 (GLP-1) (28-36) for treating type-2 diabetes, B.S-GLP-1(28-36), a recombinant Bacillus subtilis spores transformed with a plasmid vector encoding five consecutive GLP-1 (28-36) nonapeptides with an enterokinase site was constructed.. GLP-1(28-36) nonapeptide was successfully expressed on the surface of B. subtilis spores and validated by Western blot and immunofluorescence. The therapeutic effect of oral administration of B.S-GLP-1(28-36) spores was evaluated in type 2 diabetic model mice. The efficacy of recombinant spores was examined for a period of 13 weeks after oral administration in diabetic mice. At the end of the sixth week, diabetic mice with oral administration of BS-GLP-1(28-36) spores showed decreased blood glucose levels from 2·4 × 10. The results of pathological observation showed that the recombinant spores also had a certain protective effect on the liver and islets of mice, and the content of GLP-1(28-36) in the pancreas of the experimental group was increased.. The results of this study revealed that GLP-1(28-36) nonapeptides can reduce blood glucose and play an important role in the treatment of type 2 diabetes. Topics: Administration, Oral; Animals; Bacillus subtilis; Blood Glucose; Cell Surface Display Techniques; Diabetes Mellitus, Experimental; Diabetes Mellitus, Type 2; Glucagon-Like Peptide 1; Incretins; Insulin; Male; Mice; Recombinant Proteins; Spores, Bacterial; Treatment Outcome | 2021 |
Glucagon-like peptide-1 analogues and thyroid cancer: An analysis of cases reported in the European pharmacovigilance database.
The use of glucagon-like peptide-1 (GLP-1) analogues has been linked to the risk of thyroid cancer. Spontaneous reports can provide information about rare adverse events occurring after the time of marketing. Our objective was to detect, from the European pharmacovigilance database (EudraVigilance), a signal of thyroid cancer during GLP-1 analogues treatment in patients with diabetes.. Herein, we analysed all reports of thyroid cancer reported with GLP-1 analogues in EudraVigilance database from their first marketing authorization till 30 January 2020. A case/non-case method was used to assess the association between thyroid cancer and GLP-1 analogues, calculating proportional reporting ratios (PRRs) and their 95% confidence interval (CI) as a measure of disproportionality. The cases were identified with Medical Dictionary for Regulatory Activities (MedDRA) version 22.1.. There were 11 243 cases of thyroid cancer and related preferred terms (PTs) in the 6 665 794 reports recorded in EudraVigilance during the study period. GLP-1 analogues were involved in 236 cases. Exenatide, liraglutide and dulaglutide met the criteria to generate a safety signal, suggesting that thyroid cancer is reported relatively more frequently in association with these drugs than with other medicinal products. The association was strongest for liraglutide followed by exenatide with PRR of 27.5 (95% CI, 22.7-33.3) and 22.5 (95% CI, 17.9-28.3), respectively. Disproportionality was also observed for GLP-1 analogues and individual identified preferred term, that is thyroid cancer (N = 111), medullary thyroid cancer (N = 64) and thyroid neoplasm (N = 46) with PRR of 14.4 (95% CI, 11.8-17.4), 221.5 (95% CI, 155.7-315.1) and 35.5 (95% CI, 25.9-48.5), respectively.. Our findings showed disproportionality for thyroid cancer, medullary thyroid cancer and thyroid neoplasm in patients treated with GLP-1 analogues. We have found evidence from spontaneous reports that GLP-1 analogues are associated with thyroid cancer in patients with diabetes. Topics: Adolescent; Adult; Aged; Aged, 80 and over; Databases, Factual; Diabetes Mellitus, Type 2; Europe; Female; Glucagon-Like Peptide 1; Humans; Hypoglycemic Agents; Male; Middle Aged; Pharmacovigilance; Thyroid Neoplasms; Young Adult | 2021 |
Albumin-binding domain extends half-life of glucagon-like peptide-1.
Glucagon-like peptide-1 (GLP-1) is considered to be a promising peptide for the treatment of type 2 diabetes mellitus (T2DM). However, the extremely short half-life of GLP-1 limits its clinical application. Albumin-binding domain (ABD) with high affinity for human serum albumin (HSA) has been used widely for half-life extension of therapeutic peptides and proteins. In the present study, novel GLP-1 receptor agonists were designed by genetic fusion of GLP-1 to three kinds of ABDs with different affinities for HSA: GA3, ABD035 and ABDCon. The bioactivities and half-lives of ABD-fusion GLP-1 proteins with different types and lengths of linkers were investigated in vitro and in vivo. The results demonstrated that ABD-fusion GLP-1 proteins could bind to HSA with high affinity. The blood glucose-lowering effect of GLP-1 was significantly improved and sustained by fusion to ABD. Meanwhile, the fusion proteins significantly inhibited food intake, which was beneficial for T2DM and obesity treatment. The half-life of GLP-1 was substantially extended by virtue of ABD. The in vivo results also showed that a longer linker inserted between GLP-1 and ABD resulted in a higher blood glucose-lowering effect. The fusion proteins generated by fusion of GLP-1 to GA3, ABD035 and ABDCon exhibited similar bioactivities and pharmacokinetics in vivo. These findings demonstrate that ABD-fusion GLP-1 proteins retain the bioactivities of natural GLP-1 and can be further developed for T2DM treatment and weight loss. It also indicates that the ABD-fusion strategy can be generally applicable to any peptide or protein, to improve pharmacodynamic and pharmacokinetic properties. Topics: Animals; Anti-Obesity Agents; Blood Glucose; Diabetes Mellitus, Type 2; Eating; Female; Glucagon-Like Peptide 1; Glucagon-Like Peptide-1 Receptor; Glucose Tolerance Test; Half-Life; Humans; Hypoglycemic Agents; Male; Mice, Inbred BALB C; Mice, Inbred C57BL; Protein Binding; Protein Domains; Recombinant Fusion Proteins; Serum Albumin, Human | 2021 |
Hyper-Activation of Endogenous GLP-1 System to Gram-negative Sepsis Is Associated With Early Innate Immune Response and Modulated by Diabetes.
Culture-positive gram-negative sepsis induces greater magnitude of early innate immunity /inflammatory response compared with culture-negative sepsis. We previously demonstrated increased activation of anti-inflammatory Glucagon Like Peptide-1 (GLP-1) hormone in initial phase of sepsis more pronounced in diabetes patients. However, whether GLP-1 system is hyperactivated during the early innate immune response to gram-negative sepsis and modulated by diabetes remains unknown.. Total and active GLP-1, soluble Dipeptidyl peptidase 4 (sDPP-4) enzyme, and innate immunity markers presepsin (sCD14) and procalcitonin (PCT) in plasma were determined by ELISA on admission and after 2 to 4 days in 37 adult patients with and without type 2 diabetes and gram-negative or culture-negative sepsis of different severity.. Severe but not non-severe sepsis was associated with markedly increased GLP-1 system response, which correlated with PCT and the organ dysfunction marker lactate. Culture-positive gram-negative bacteria but not culture-negative sepsis induced hyper-activation of GLP-1 system, which correlated with increased innate immune markers sCD14, PCT, and lactate. GLP-1 inhibitory enzyme sDPP-4 was down regulated by sepsis and correlated negatively with sCD14 in gram-negative sepsis. Diabetic patients demonstrated increased GLP-1 response but significantly weaker innate immune response to severe and gram-negative sepsis.. Early stage of gram-negative sepsis is characterized by endogenous GLP-1 system hyperactivity associated with over activation of innate immune response and organ dysfunction, which are modulated by diabetes. Total GLP-1 may be novel marker for rapid diagnosis of gram-negative sepsis and its severity. Topics: Adult; Aged; Aged, 80 and over; Diabetes Mellitus, Type 2; Female; Glucagon-Like Peptide 1; Gram-Negative Bacterial Infections; Humans; Immunity, Innate; Male; Middle Aged; Sepsis; Time Factors; Young Adult | 2021 |
GLP-1 modulates insulin-induced relaxation response through β-arrestin2 regulation in diabetic mice aortas.
Diabetes impairs insulin-induced endothelium-dependent relaxation by reducing nitric oxide (NO) production. GLP-1, an incretin hormone, has been shown to prevent the development of endothelial dysfunction. In this study, we hypothesized that GLP-1 would improve the impaired insulin-induced relaxation response in diabetic mice. We also examined the underlying mechanisms.. Using aortic rings from ob/ob mice, an animal model of obesity and type 2 diabetes, and from lean mice, vascular relaxation responses and protein expressions were evaluated using insulin, GLP-1, and pathway-specific inhibitors to elucidate the mechanisms of response. In parallel experiments, β-arrestin2 siRNA-transfected aortas were treated with GLP-1 to evaluate its effects on aortic response pathways.. When compared to that of untreated ob/ob aortas, GLP-1 increased insulin-induced vasorelaxation and NO production. AMPK inhibition did not alter this vasorelaxation in both GLP-1-treated lean and ob/ob aortas, while Akt inhibition reduced vasorelaxation in both groups, and co-treatment with GLP-1 and insulin caused Akt/eNOS activation. Additionally, GLP-1 decreased GRK2 activity and enhanced β-arrestin2 translocation from the cytosol to membrane in ob/ob aortas. β-Arrestin2 siRNA decreased insulin-induced relaxation both in lean aortas and GLP-1-treated ob/ob aortas.. We demonstrated that insulin-induced relaxation is dependent on β-arrestin2 translocation and Akt activation via GLP-1-stimulated GRK2 inactivation in ob/ob aortas. We showed a novel cross-talk between GLP-1-responsive β-arrestin2 and insulin signalling in diabetic aortas. Topics: Animals; Aorta; beta-Arrestin 1; Diabetes Mellitus, Experimental; Diabetes Mellitus, Type 2; Endothelium, Vascular; Glucagon-Like Peptide 1; Insulin; Mice; Nitric Oxide Synthase Type III; Proto-Oncogene Proteins c-akt; Vasodilation | 2021 |
Different mechanisms of GIP and GLP-1 action explain their different therapeutic efficacy in type 2 diabetes.
The reduced action of incretin hormones in type 2 diabetes (T2D) is mainly attributed to GIP insensitivity, but efficacy estimates of GIP and GLP-1 differ among studies, and the negligible effects of pharmacological GIP doses remain unexplained. We aimed to characterize incretin action in vivo in subjects with normal glucose tolerance (NGT) or T2D and provide an explanation for the different insulinotropic activity of GIP and GLP-1 in T2D subjects.. We used in vivo data from ten studies employing hormone infusion or an oral glucose test (OGTT). To homogeneously interpret and compare the results of the studies we performed the analysis using a mathematical model of the β-cell incorporating the effects of incretins on the triggering and amplifying pathways. The effect on the amplifying pathway was quantified by a time-dependent factor that is greater than one when insulin secretion (ISR) is amplified by incretins. To validate the model results for GIP in NGT subjects, we performed an extensive literature search of the available data.. a) the stimulatory effects of GIP and GLP-1 differ markedly: ISR potentiation increases linearly with GLP-1 over the whole dose range, while with GIP infusion it reaches a plateau at ~100 pmol/L GIP, with ISR potentiation of ~2 fold; b) ISR potentiation in T2D is reduced by ~50% for GIP and by ~40% for GLP-1; c) the literature search of GIP in NGT subjects confirmed the saturative effect on insulin secretion.. We show that incretin potentiation of ISR is reduced in T2D, but not abolished, and that the lack of effects of pharmacological GIP doses is due to saturation of the GIP effect more than insensitivity to GIP in T2D. Topics: Blood Glucose; Diabetes Mellitus, Type 2; Gastric Inhibitory Polypeptide; Glucagon-Like Peptide 1; Glucose Tolerance Test; Humans; Incretins; Insulin Secretion; Insulin-Secreting Cells; Models, Theoretical | 2021 |
Diabetes and Its Complications: Therapies Available, Anticipated and Aspired.
Worldwide, diabetes ranks among the ten leading causes of mortality. Prevalence of diabetes is growing rapidly in low and middle income countries. It is a progressive disease leading to serious co-morbidities, which results in increased cost of treatment and over-all health system of the country. Pathophysiological alterations in Type 2 Diabetes (T2D) progressed from a simple disturbance in the functioning of the pancreas to triumvirate to ominous octet to egregious eleven to dirty dozen model. Due to complex interplay of multiple hormones in T2D, there may be multifaceted approach in its management. The 'long-term secondary complications' in uncontrolled diabetes may affect almost every organ of the body, and finally may lead to multi-organ dysfunction. Available therapies are inconsistent in maintaining long term glycemic control and their long term use may be associated with adverse effects. There is need for newer drugs, not only for glycemic control but also for prevention or mitigation of secondary microvascular and macrovascular complications. Increased knowledge of the pathophysiology of diabetes has contributed to the development of novel treatments. Several new agents like Glucagon Like Peptide - 1 (GLP-1) agonists, Dipeptidyl Peptidase IV (DPP-4) inhibitors, amylin analogues, Sodium-Glucose transport -2 (SGLT- 2) inhibitors and dual Peroxisome Proliferator-Activated Receptor (PPAR) agonists are available or will be available soon, thus extending the range of therapy for T2D, thereby preventing its long term complications. The article discusses the pathophysiology of diabetes along with its comorbidities, with a focus on existing and novel upcoming antidiabetic drugs which are under investigation. It also dives deep to deliberate upon the novel therapies that are in various stages of development. Adding new options with new mechanisms of action to the treatment armamentarium of diabetes may eventually help improve outcomes and reduce its economic burden. Topics: Diabetes Mellitus, Type 2; Dipeptidyl-Peptidase IV Inhibitors; Glucagon-Like Peptide 1; Humans; Hypoglycemic Agents | 2021 |
Diet-induced obesity enhances postprandial glucagon-like peptide-1 secretion in Wistar rats, but not in diabetic Goto-Kakizaki rats.
Glucagon-like peptide-1 (GLP-1) is postprandially secreted from enteroendocrine L-cells and enhances insulin secretion. Currently, it is still controversial whether postprandial GLP-1 responses are altered in obesity and diabetes. To address the issue and to find out possible factors related, we compared postprandial GLP-1 responses in normal rats and in diabetic rats chronically fed an obesogenic diet. Male Wistar rats and diabetic Goto-Kakizaki (GK) rats were fed either a control diet or a high-fat/high-sucrose (HFS, 30 % fat and 40 % sucrose) diet for 26 weeks. Meal tolerance tests were performed for monitoring postprandial responses after a liquid diet administration (62·76 kJ/kg body weight) every 4 or 8 weeks. Postprandial glucose, GLP-1 and insulin responses in Wistar rats fed the HFS diet (WH) were higher than Wistar rats fed the control diet (WC). Although GK rats fed the HFS diet (GH) had higher glycaemic responses than GK rats fed the control diet (GC), these groups had similar postprandial GLP-1 and insulin responses throughout the study. Jejunal and ileal GLP-1 contents were increased by the HFS diet only in Wistar rats. Furthermore, mRNA expression levels of fatty acid receptors (Ffar1) in the jejunum were mildly (P = 0·053) increased by the HFS diet in Wistar rats, but not in GK rats. These results demonstrate that postprandial GLP-1 responses are enhanced under an obesogenic status in normal rats, but not in diabetic rats. Failure of adaptive enhancement of GLP-1 response in GK rats could be partly responsible for the development of glucose intolerance. Topics: Animals; Blood Glucose; Diabetes Mellitus, Experimental; Diabetes Mellitus, Type 2; Diet, High-Fat; Glucagon-Like Peptide 1; Insulin; Male; Obesity; Rats; Rats, Wistar | 2021 |
Preparation of Nanocomposite Peptide and Its Inhibitory Effect on Myocardial Injury in Type-II Diabetic Rats.
Complications of diabetes are the main cause of death and disability in diabetic patients. Cardiovascular diseases, especially diabetic cardiomyopathy, are one of the major complications and causes of death in type 2 diabetes. Peptide drugs have a better effect on improving cellular oxidative damage, reducing tissue inflammation and inhibiting intracellular calcium overload. The application of nanotechnology to the preparation of peptide drugs and myocardial injury can effectively improve myocardial stun, arrhythmia and myocardial systolic dysfunction in patients with type 2 diabetes. The use of nanotechnology to develop more stable Glucagon-like peptide 1 analogues or sustained-release preparations, improve patient compliance and improve the efficacy of diabetes, is of great significance for the prevention and treatment of diabetic cardiomyopathy. Therefore, this study used nanotechnology to prepare PLGA-GLP-1 nanoparticles using polyglycolic acid glycolic acid as a drug carrier, which achieved long-acting drug and its morphology by transmission electron microscopy. At the same time, this study explored the anti-cardiomyocyte injury and anti-myocardial damage of PLGA-GLP-1 nanocomposite peptide and its molecular mechanism by using animal models and cell models. Experimental studies have shown that PLGA-GLP-1 nanocomposite peptide has a protective effect on myocardial injury in diabetic rats. Its mechanism is related to the PLGA-GLP-1 nanocomposite peptide enhancing the body's antioxidant capacity, anti-cardiomyocyte apoptosis, and promoting mitochondrial DNA repair in cardiomyocytes. Topics: Animals; Diabetes Mellitus, Experimental; Diabetes Mellitus, Type 2; Glucagon-Like Peptide 1; Humans; Nanocomposites; Peptides; Rats | 2021 |
GK-rats respond to gastric bypass surgery with improved glycemia despite unaffected insulin secretion and beta cell mass.
Roux-en-Y gastric bypass (RYGB) is the most effective treatment for morbid obesity and results in rapid remission of type 2 diabetes (T2D), before significant weight loss occurs. The underlying mechanisms for T2D remission are not fully understood. To gain insight into these mechanisms we used RYGB-operated diabetic GK-rats and Wistar control rats. Twelve adult male Wistar- and twelve adult male GK-rats were subjected to RYGB- or sham-operation. Oral glucose tolerance tests (OGTT) were performed six weeks after surgery. RYGB normalized fasting glucose levels in GK-rats, without affecting fasting insulin levels. In both rat strains, RYGB caused increased postprandial responses in glucose, GLP-1, and GIP. RYGB caused elevated postprandial insulin secretion in Wistar-rats, but had no effect on insulin secretion in GK-rats. In agreement with this, RYGB improved HOMA-IR in GK-rats, but had no effect on HOMA-β. RYGB-operated GK-rats had an increased number of GIP receptor and GLP-1 receptor immunoreactive islet cells, but RYGB had no major effect on beta or alpha cell mass. Furthermore, in RYGB-operated GK-rats, increased Slc5a1, Pck2 and Pfkfb1 and reduced Fasn hepatic mRNA expression was observed. In summary, our data shows that RYGB induces T2D remission and enhanced postprandial incretin hormone secretion in GK-rats, without affecting insulin secretion or beta cell mass. Thus our data question the dogmatic view of how T2D remission is achieved and instead point at improved insulin sensitivity as the main mechanism of remission. Topics: Animals; Diabetes Mellitus, Type 2; Disease Models, Animal; Gastric Bypass; Gastric Inhibitory Polypeptide; Glucagon-Like Peptide 1; Glucose Tolerance Test; Humans; Insulin; Insulin Secretion; Insulin-Secreting Cells; Islets of Langerhans; Obesity, Morbid; Rats; Rats, Wistar; Weight Loss | 2021 |
Secondary analysis of gut hormone data from children with and without in utero exposure to gestational diabetes: Differences in the associations among ghrelin, GLP-1, and insulin secretion.
Intrauterine exposure to gestational diabetes mellitus (GDM) increases risk for type 2 diabetes (T2D). Ghrelin and GLP-1 have opposite functions in nutritional homeostasis and are associated with insulin secretion, but it is not known if individuals exposed to GDM exhibit dysregulation in these associations.. Test the hypothesis that children exposed to GDM in utero will exhibit dysregulation among ghrelin, GLP-1, and C-peptide (reflecting insulin secretion).. Data from N = 43 children aged 5 to 10 years were included in this secondary analysis of ghrelin, GLP-1, and C-peptide response to a liquid meal test. Repeated measures mixed model analyses were used to measure associations among hormones.. The association of ghrelin and GLP-1 was moderated by GDM group (P < .01), such that ghrelin was inversely associated with GLP-1 in children without GDM exposure, but not for those exposed to GDM. GLP-1 was positively associated with C-peptide in both groups, but the association was stronger in those exposed to GDM (estimate = 1.06 vs 1.01).. Differences in the associations among ghrelin, GLP-1, and C-peptide displayed here suggest novel lines of research about whether the regulation of gut hormones and insulin secretion contribute to obesity and risk for T2D in children exposed to GDM. Topics: Child; Child, Preschool; Diabetes Mellitus, Type 2; Diabetes, Gestational; Female; Ghrelin; Glucagon-Like Peptide 1; Humans; Insulin; Insulin Secretion; Pregnancy; Prenatal Exposure Delayed Effects | 2021 |
Incretins in fibrocalculous pancreatic diabetes: A unique subtype of pancreatogenic diabetes.
Studies evaluating endocrine and exocrine functions in fibrocalculous pancreatic diabetes (FCPD) are scarce.. Insulin, C-peptide, glucagon, incretin hormones (glucagon-like peptide 1 [GLP-1] and gastric inhibitory peptide [GIP]), and dipeptidyl peptidase IV (DPP-IV) were estimated in patients with FCPD (n = 20), type 2 diabetes mellitus (T2DM) (n = 20), and controls (n = 20) in fasting and 60 minutes after 75 g glucose.. Fasting and post-glucose C-peptide and insulin in FCPD were lower than that of T2DM and controls. Plasma glucagon decreased after glucose load in controls (3.72, 2.29), but increased in T2DM (4.01, 5.73), and remained unchanged in FCPD (3.44, 3.44). Active GLP-1 (pmol/L) after glucose load increased in FCPD (6.14 to 9.72, P = <.001), in T2DM (2.87 to 4.62, P < .001), and in controls (3.91 to 6.13, P < .001). Median active GLP-1 in FCPD, both in fasting and post-glucose state (6.14, 9.72), was twice that of T2DM (2.87, 4.62) and 1.5 times that of controls (3.91, 6.13) (P < .001 for all). Post-glucose GIP (pmol/L) increased in all: FCPD (15.83 to 94.14), T2DM (21.85 to 88.29), and control (13.00 to 74.65) (P < .001 for all). GIP was not different between groups. DPP-IV concentration (ng/mL) increased in controls (1578.54, 3012.00) and FCPD (1609.95, 1995.42), but not in T2DM (1204.50, 1939.50) (P = .131). DPP-IV between the three groups was not different. Fecal elastase was low in FCPD compared with T2DM controls.. In FCPD, basal C-peptide and glucagon are low, and glucagon does not increase after glucose load. GLP-1, but not GIP, in FCPD increases 1.5 to 2 times as compared with T2DM and controls (fasting and post glucose) without differences in DPP-IV.. 背景: 评价纤维结石性胰腺糖尿病(FCPD)内分泌和外分泌功能的研究很少。 方法: 测定FCPD组(n=20)、2型糖尿病(T2 DM)组(n=20)和对照组(n=20)空腹和75g葡萄糖后60min的胰岛素、C肽、胰高血糖素、肠泌素(胰高血糖素样肽1[GLP-1]和胃抑制肽[GIP])、二肽基肽酶IV(DPP-IV)水平。 结果: FCPD组空腹和糖负荷后C肽、胰岛素水平均低于T2 DM组和对照组。对照组糖负荷后胰高血糖素(pmol/L)降低(3.72; 2.29); T2 DM组升高(4.01; 5.73); FCPD组(3.44; 3.44)无明显变化。FCPD组(6.14~9.72; P=<0.001)、T2 DM组(2.87~4.62; P<0.001)和对照组(3.91~6.13; P<0.001)糖负荷后活性GLP-1(pmol/L)升高。FCPD组空腹和糖负荷后GLP-1(pmol/L)活性中位数(6.14; 9.72)是T2 DM组(2.87; 4.62)的两倍; 是对照组(3.91; 6.13)的1.5倍(P<0.001)。糖负荷后GIP(pmol/L)在所有组别中都升高:FCPD(15.83~94.14)、T2DM(21.85~88.29)、对照组(13.00~74.65), P<0.01。不同组间GIP差异无统计学意义。对照组(1578.54,3012.00)和FCPD组(1609.95,1995.42)的DPP-IV浓度(ng/mL)升高; 而T2 DM组(1204.50,1939.50)的DPP-IV浓度无明显变化(P=0.131)。DPP-IV于三组间差异无统计学意义。FCPD组中粪弹性蛋白酶低于T2 DM组对照组。 结论: FCPD患者糖负荷后基础C肽和胰高血糖素降低; 在糖负荷后胰高血糖素不升高。FCPD的GLP-1; 而不是GIP; 与T2 DM和对照组(空腹和糖负荷后)相比升高了1.5-2倍; 而DPP-IV没有差异. Topics: Adolescent; Adult; Biomarkers; Blood Glucose; C-Peptide; Calcinosis; Case-Control Studies; Diabetes Mellitus, Type 2; Dipeptidyl Peptidase 4; Female; Fibrosis; Gastric Inhibitory Polypeptide; Glucagon; Glucagon-Like Peptide 1; Humans; Hypoglycemic Agents; Incretins; Insulin; Male; Middle Aged; Pancreatitis, Chronic; Time Factors; Young Adult | 2021 |
Novel GLP-1 analog supaglutide improves glucose homeostasis in diabetic monkeys.
Glucagon-like peptide 1 (GLP-1) is an insulinotropic hormone and plays an important role in regulating glucose homeostasis. GLP-1 has a short half-life (t1/2 < 2 min) due to degrading enzyme dipeptidyl peptidase-IV and rapid kidney clearance, which limits its clinical application as a therapeutic reagent. We demonstrated recently that supaglutide, a novel GLP-1 mimetic generated by recombinant fusion protein techniques, exerted hypoglycemic and β-cell trophic effects in type 2 diabetes db/db mice. In the present study, we examined supaglutide's therapeutic efficacy and pharmacokinetics in diabetic rhesus monkeys. We found that a single subcutaneous injection of supaglutide of tested doses transiently and significantly reduced blood glucose levels in a dose-dependent fashion in the diabetic monkeys. During a 4-week intervention period, treatment of supaglutide of weekly dosing dose-dependently decreased fasting and random blood glucose levels. This was associated with significantly declined plasma fructosamine levels. The repeated administration of supaglutide remarkably also decreased body weight in a dose-dependent fashion accompanied by decreased food intake. Intravenous glucose tolerance test results showed that supaglutide improved glucose tolerance. The intervention also showed enhanced glucose-stimulated insulin secretion and improved lipid profile in diabetic rhesus monkeys. These results reveal that supaglutide exerts beneficial effects in regulating blood glucose and lipid homeostasis in diabetic rhesus monkeys. Topics: Animals; Blood Glucose; Body Weight; Diabetes Mellitus, Type 2; Drug Evaluation, Preclinical; Glucagon-Like Peptide 1; Insulin; Insulin Secretion; Lipid Metabolism; Macaca mulatta; Male | 2021 |
Effects of a glucagon-like peptide-1 analog on appetitive and consummatory behavior for rewarding and aversive gustatory stimuli in rats.
Glucagon-like peptide-1 (GLP-1) is an incretin hormone that is essential for the regulation of food intake and approved for the treatment of type 2 diabetes mellitus and obesity in humans. More recently, GLP-1 has been investigated for its ability to modulate motivation for food and drugs. Reward behavior can be divided into two components: 'motivational' (i.e., approach and consummatory behaviors) and 'affective' (i.e., perceived palatability). Studies show that GLP-1 analogs reduce the motivation to approach and consume palatable food, but the impact on affective responding is unknown. Thus, the present study tested the effect of the GLP-1 analog, Exendin-4 (Ex-4), on the appetitive response to intraorally delivered sucrose and quinine. Results showed that Ex-4 (2.4ug/kg ip) failed to alter passive drip, appetitive reactions (i.e., mouth movements, tongue protrusions, and lateral tongue protrusions) or aversive reactions (i.e., gapes) to sucrose. Paw-licking, however, was significantly reduced by Ex-4. Treatment with Ex-4 also failed to influence passive drip to quinine, but increased the latency to gape and reduced the total number of gapes emitted. In addition, Ex-4 reduced intake of quinine in water restricted rats, but did not reduce conditioned aversion (i.e., gapes) or avoidance (i.e., reduced intake) of a LiCl-paired saccharin cue. Thus, while Ex-4 had no effect on a learned aversion, it reduced approach and ingestion of sweet and bitter solutions, while leaving the appetitive affective response to the sweet almost intact, and the aversive affective response to the bitter reduced. Treatment with Ex-4, then, differentially modulates appetitive and consummatory components of reward, depending on the valence of the stimulus and whether its valence is learned or innate. Topics: Animals; Appetitive Behavior; Consummatory Behavior; Diabetes Mellitus, Type 2; Glucagon-Like Peptide 1; Rats; Reward; Taste | 2021 |
Circulating cathepsin S improves glycaemic control in mice.
Cathepsin S (CTSS) is a cysteine protease that regulates many physiological processes and is increased in obesity and type 2 diabetes. While previous studies show that deletion of CTSS improves glycaemic control through suppression of hepatic glucose output, little is known about the role of circulating CTSS in regulating glucose and energy metabolism. We assessed the effects of recombinant CTSS on metabolism in cultured hepatocytes, myotubes and adipocytes, and in mice following acute CTSS administration. CTSS improved glucose tolerance in lean mice and this coincided with increased plasma insulin. CTSS reduced G6pc and Pck1 mRNA expression and glucose output from hepatocytes but did not affect glucose metabolism in myotubes or adipocytes. CTSS did not affect insulin secretion from pancreatic β-cells, rather CTSS stimulated glucagon-like peptide (GLP)-1 secretion from intestinal mucosal tissues. CTSS retained its positive effects on glycaemic control in mice injected with the GLP1 receptor antagonist Exendin (9-39) amide. The effects of CTSS on glycaemic control were not retained in high-fat-fed mice or db/db mice, despite the preservation of CTSS' inhibitory actions on hepatic glucose output in isolated primary hepatocytes. In conclusion, we unveil a role for CTSS in the regulation of glycaemic control via direct effects on hepatocytes, and that these effects on glycaemic control are abrogated in insulin resistant states. Topics: 3T3-L1 Cells; Adipocytes; Animals; Blood Glucose; Cathepsins; Diabetes Mellitus, Type 2; Drug Evaluation, Preclinical; Glucagon-Like Peptide 1; Glucose; Glycemic Control; Liver; Mice | 2021 |
Hyocholic acid species improve glucose homeostasis through a distinct TGR5 and FXR signaling mechanism.
Hyocholic acid (HCA) and its derivatives are found in trace amounts in human blood but constitute approximately 76% of the bile acid (BA) pool in pigs, a species known for its exceptional resistance to type 2 diabetes. Here, we show that BA depletion in pigs suppressed secretion of glucagon-like peptide-1 (GLP-1) and increased blood glucose levels. HCA administration in diabetic mouse models improved serum fasting GLP-1 secretion and glucose homeostasis to a greater extent than tauroursodeoxycholic acid. HCA upregulated GLP-1 production and secretion in enteroendocrine cells via simultaneously activating G-protein-coupled BA receptor, TGR5, and inhibiting farnesoid X receptor (FXR), a unique mechanism that is not found in other BA species. We verified the findings in TGR5 knockout, intestinal FXR activation, and GLP-1 receptor inhibition mouse models. Finally, we confirmed in a clinical cohort, that lower serum concentrations of HCA species were associated with diabetes and closely related to glycemic markers. Topics: Animals; Blood Glucose; Cell Line; Cholic Acids; Diabetes Mellitus, Experimental; Diabetes Mellitus, Type 2; Glucagon-Like Peptide 1; Glucagon-Like Peptide-1 Receptor; Glucose; Humans; Isoxazoles; Male; Mice; Mice, Inbred C57BL; Mice, Knockout; Receptors, Cytoplasmic and Nuclear; Receptors, G-Protein-Coupled; Signal Transduction; Swine | 2021 |
The ginsenoside metabolite compound K stimulates glucagon-like peptide-1 secretion in NCI-H716 cells by regulating the RhoA/ROCKs/YAP signaling pathway and cytoskeleton formation.
Ginsenoside Rb1 has been shown to have antidiabetic and anti-inflammatory effects. Its major metabolite, compound K (CK), can stimulate the secretion of glucagon-like peptide-1 (GLP1), a gastrointestinal hormone that plays a vital role in regulating glucose metabolism. However, the mechanism underlying the regulation of GLP1 secretion by compound K has not been fully explored. This study was designed to investigate whether CK ameliorates incretin impairment by regulating the RhoA/ROCKs/YAP signaling pathway and cytoskeleton formation in NCI-H716 cells. Using NCI-H716 cells as a model cell line for GLP1 secretion, we analyzed the effect of CK on the expression of RhoA/ROCK/YAP pathway components. Our results suggest that the effect of CK on GLP1 secretion depends on the anti-inflammatory effect of CK. We also demonstrated that CK can affect the RhoA/ROCK/YAP pathway, which is downstream of transforming growth factor β1 (TGFβ1), by maintaining the capacity of intestinal differentiation. In addition, this effect was mediated by regulating F/G-actin dynamics. These results provide not only the mechanistic insight for the effect of CK on intestinal L cells but also the molecular basis for the further development of CK as a potential therapeutic agent to treat type 2 diabetes mellitus (T2D). Topics: Cell Cycle Proteins; Cell Line; Cytoskeleton; Diabetes Mellitus, Type 2; Ginsenosides; Glucagon-Like Peptide 1; Humans; Molecular Targeted Therapy; Phytotherapy; rho-Associated Kinases; rhoA GTP-Binding Protein; Signal Transduction; Transcription Factors; Transforming Growth Factor beta1 | 2021 |
Newly prescribed canagliflozin vs. GLP-1 agonists was linked to amputation in older adults with type 2 DM and CVD.
Fralick M, Kim SC, Schneeweiss S, et al. Topics: Aged; Amputation, Surgical; Canagliflozin; Cardiovascular Diseases; Cohort Studies; Diabetes Mellitus, Type 2; Glucagon-Like Peptide 1; Heart Disease Risk Factors; Humans; Hypoglycemic Agents; Retrospective Studies; Risk Factors | 2021 |
Neutral effect of exenatide on serum testosterone in men with type 2 diabetes mellitus: A prospective cohort.
Endogenous testosterone increases with weight loss from diet, exercise, and bariatric surgery. However, little is known about testosterone levels after weight loss from medication.. Uncover the effects of Glucagon-Like Peptide-1 receptor agonist (GLP-1 RA) therapy on serum testosterone.. Prospective cohort study of men starting GLP-1 RA therapy for type 2 diabetes mellitus.. 51 men lost 2.27 kg (p = 0.00162) and their HbA1c values improved by 0.7% (p = 0.000503) after 6 months of GLP-1 RA therapy. There was no significant change in testosterone for the group as a whole. However, in subgroup analyses, there was a significant difference in total testosterone change between men starting with baseline total testosterone <320 ng/dL (238.5 ± 56.5 ng/dL to 272.2 ± 82.3 ng/dL) compared to higher values (438 ± 98.2 ng/dL to 412 ± 141.2 ng/dL) (p = 0.0172);free testosterone increased if the baseline total testosterone was <320 ng/dL (55.2 ± 12.8 pg/mL to 57.2 ± 17.6 pg/mL) and decreased if >320 ng/dL (74.7 ± 16.3 pg/mL to 64.2 ± 17.7 pg/mL) (p = 0.00807). Additionally, there were significant differences in testosterone change between men with HbA1c improvements ≥1% (351.6 ± 123.9 ng/dL to 394.4 ± 136.5 ng/dL) compared to men with HbA1c changes <1% (331.8 ± 128.6 ng/dL to 316.1 ± 126.2 ng/dL) (p = 0.0413).. GLP-1 RA therapy improves weight and HbA1c without adverse effects on testosterone. Those starting with lower testosterone values or attaining greater improvement in HbA1c may see additional benefits. Topics: Aged; Diabetes Mellitus, Type 2; Exenatide; Glucagon-Like Peptide 1; Humans; Hypoglycemic Agents; Male; Middle Aged; Prospective Studies; Testosterone | 2021 |
A microbial metabolite remodels the gut-liver axis following bariatric surgery.
Bariatric surgery is the most effective treatment for type 2 diabetes and is associated with changes in gut metabolites. Previous work uncovered a gut-restricted TGR5 agonist with anti-diabetic properties-cholic acid-7-sulfate (CA7S)-that is elevated following sleeve gastrectomy (SG). Here, we elucidate a microbiome-dependent pathway by which SG increases CA7S production. We show that a microbial metabolite, lithocholic acid (LCA), is increased in murine portal veins post-SG and by activating the vitamin D receptor, induces hepatic mSult2A1/hSULT2A expression to drive CA7S production. An SG-induced shift in the microbiome increases gut expression of the bile acid transporters Asbt and Ostα, which in turn facilitate selective transport of LCA across the gut epithelium. Cecal microbiota transplant from SG animals is sufficient to recreate the pathway in germ-free (GF) animals. Activation of this gut-liver pathway leads to CA7S synthesis and GLP-1 secretion, causally connecting a microbial metabolite with the improvement of diabetic phenotypes. Topics: Animals; Bariatric Surgery; Diabetes Mellitus, Type 2; Gastrectomy; Gastrointestinal Microbiome; Germ-Free Life; Glucagon-Like Peptide 1; Hep G2 Cells; Humans; Ileum; Liver; Male; Mice; Mice, Inbred C57BL; Mice, Knockout; Receptors, Calcitriol; Sulfotransferases | 2021 |
GLP-1 RA and atrial fibrillation in the cardiovascular outcome trials.
Topics: Atrial Fibrillation; Cardiovascular System; Diabetes Mellitus, Type 2; Glucagon-Like Peptide 1; Glucagon-Like Peptide-1 Receptor; Humans; Hypoglycemic Agents | 2021 |
Are glucagon-like peptide 1 analogues effective and safe in severe COVID-19 patients with type 2 diabetes?-a case report.
Many cases of novel coronavirus 2019 (COVID-19) have confirmed in many countries around the world. Due to the disorders of the immune system, diabetic patients are more likely to suffer from severe COVID-19. Glucagon-like peptide 1 analogues (GLP-1 analogues) commonly can be used to reduce blood sugar. There is no clear evidence that it can be safely and effectively used in patients with diabetes merged severe COVID-19. In this case, we described A 65-year-old male with hypertension and diabetes was diagnosed with severe COVID-19, he took liraglutide at doses ranging from 0.8 to 1.8 mg. Before admission, liraglutide was not used to reduce blood glucose. Hydroxychloroquine sulfate and abidol were used to antivirus and supportive treatment were used simultaneously during hospitalization. During treatment, the patient's own state was paid attention to, and blood glucose, liver function, kidney function, white blood cells, lymphocytes and other indicators were checked and chest CT was reviewed regularly, which could reflect changes in disease. After treatment, the patient's blood glucose was under control, and his liver function, renal function, white blood cells, lymphocytes and other indicators were normal and chest CT also improved. The case showed that liraglutide may be effective and safe used in patients with severe COVID-19 combined with type 2 diabetes, but more clinical trials are needed. Topics: Aged; COVID-19; Diabetes Mellitus, Type 2; Glucagon-Like Peptide 1; Humans; Hypoglycemic Agents; Male; SARS-CoV-2 | 2021 |
Dynamic Uni- and Multicellular Patterns Encode Biphasic Activity in Pancreatic Islets.
Biphasic secretion is an autonomous feature of many endocrine micro-organs to fulfill physiological demands. The biphasic activity of islet β-cells maintains glucose homeostasis and is altered in type 2 diabetes. Nevertheless, underlying cellular or multicellular functional organizations are only partially understood. High-resolution noninvasive multielectrode array recordings permit simultaneous analysis of recruitment, of single-cell, and of coupling activity within entire islets in long-time experiments. Using this unbiased approach, we addressed the organizational modes of both first and second phase in mouse and human islets under physiological and pathophysiological conditions. Our data provide a new uni- and multicellular model of islet β-cell activation: during the first phase, small but highly active β-cell clusters are dominant, whereas during the second phase, electrical coupling generates large functional clusters via multicellular slow potentials to favor an economic sustained activity. Postprandial levels of glucagon-like peptide 1 favor coupling only in the second phase, whereas aging and glucotoxicity alter coupled activity in both phases. In summary, biphasic activity is encoded upstream of vesicle pools at the micro-organ level by multicellular electrical signals and their dynamic synchronization between β-cells. The profound alteration of the electrical organization of islets in pathophysiological conditions may contribute to functional deficits in type 2 diabetes. Topics: Animals; Diabetes Mellitus, Type 2; Electrophysiology; Glucagon-Like Peptide 1; Humans; Insulin; Insulin Secretion; Insulin-Secreting Cells; Islets of Langerhans; Male; Mice; Mice, Inbred C57BL; Postprandial Period | 2021 |
Comparative Effectiveness and Safety of Sodium-Glucose Cotransporter 2 Inhibitors Versus Glucagon-Like Peptide 1 Receptor Agonists in Older Adults.
Both sodium-glucose cotransporter 2 inhibitors (SGLT2i) and glucagon-like peptide 1 receptor agonists (GLP-1RA) demonstrated cardiovascular benefits in randomized controlled trials of patients with type 2 diabetes (T2D) generally <65 years old and mostly with cardiovascular disease. We aimed to evaluate the comparative effectiveness and safety of SGLT2i and GLP-1RA among real-world older adults.. Using Medicare data (April 2013-December 2016), we identified 90,094 propensity score-matched (1:1) T2D patients ≥66 years old initiating SGLT2i or GLP-1RA. Primary outcomes were major adverse cardiovascular events (MACE) (i.e., myocardial infarction, stroke, or cardiovascular death) and hospitalization for heart failure (HHF). Other outcomes included diabetic ketoacidosis (DKA), genital infections, fractures, lower-limb amputations (LLA), acute kidney injury (AKI), severe urinary tract infections, and overall mortality. We estimated hazard ratios (HRs) and rate differences (RDs) per 1,000 person-years, controlling for 140 baseline covariates.. Compared with GLP-1RA, SGLT2i initiators had similar MACE risk (HR 0.98 [95% CI 0.87, 1.10]; RD -0.38 [95% CI -2.48, 1.72]) and reduced HHF risk (HR 0.68 [95% CI 0.57, 0.80]; RD -3.23 [95% CI -4.68, -1.77]), over a median follow-up of ∼6 months. They also had 0.7 more DKA events (RD 0.72 [95% CI 0.02, 1.41]), 0.9 more LLA (RD 0.90 [95% CI 0.10, 1.70]), 57.1 more genital infections (RD 57.08 [95% CI 53.45, 60.70]), and 7.1 fewer AKI events (RD -7.05 [95% CI -10.27, -3.83]) per 1,000 person-years.. Among older adults, those taking SGLT2i had similar MACE risk, decreased HHF risk, and increased risk of DKA, LLA, and genital infections versus those taking GLP-1RA. Topics: Aged; Diabetes Mellitus, Type 2; Glucagon-Like Peptide 1; Glucagon-Like Peptide-1 Receptor; Glucose; Humans; Hypoglycemic Agents; Medicare; Myocardial Infarction; Sodium; Sodium-Glucose Transporter 2 Inhibitors; United States | 2021 |
Switching to iGlarLixi versus continuation of a daily or weekly glucagon-like peptide-1 receptor agonist (GLP-1 RA) in insufficiently controlled type 2 diabetes: A LixiLan-G trial subgroup analysis by HbA1c and GLP-1 RA use at screening.
In people with type 2 diabetes (T2D) requiring intensification beyond glucagon-like peptide-1 receptor agonists (GLP-1 RAs) and oral antihyperglycaemic drugs (OADs), switching to iGlarLixi was shown to be efficacious and well-tolerated in the LixiLan-G trial. This exploratory analysis of LixiLan-G assessed the efficacy and safety of switching to iGlarLixi versus continuing GLP-1 RA therapy, stratified by screening HbA1c level (≥7.0 to ≤7.5 %; >7.5 to ≤8.0 %; >8.0 to ≤9.0 % [≥53 to ≤58 mmol/mol; >58 to ≤64 mmol/mol; >64 to ≤75 mmol/mol]) and previous GLP-1 RA regimen at screening (once/twice daily or once weekly).. Endpoints for all subgroups included: change in HbA1c, achievement of HbA1c <7 % and hypoglycaemia events. Adverse events and changes in fasting plasma glucose (FPG), 2-hour postprandial plasma glucose (PPG), 2-hour PPG excursion and weight were analysed according to previous GLP-1 RA regimen.. Switching to iGlarLixi in all subgroups resulted in significantly greater reductions in HbA1c and proportions of participants reaching HbA1c <7 % (including with no documented hypoglycaemia) at Week 26 compared with continued GLP-1 RA treatment. Switching to iGlarLixi also led to significantly greater reductions in FPG, 2-hour PPG, and 2-hour PPG excursion, irrespective of previous GLP-1 RA regimen. Rates of hypoglycaemia were low, but slightly higher in those who switched to iGlarLixi for all subgroups. Modest weight gain was seen with iGlarLixi, irrespective of previous GLP-1 RA regimen.. Switching to iGlarLixi improved glycaemic control, regardless of screening HbA1c or previous GLP-1 RA type, offering a simple, efficacious and well-tolerated treatment intensification option for people with T2D inadequately controlled by GLP-1 RAs and OADs. Topics: Blood Glucose; Diabetes Mellitus, Type 2; Drug Combinations; Glucagon-Like Peptide 1; Glucagon-Like Peptide-1 Receptor; Glycated Hemoglobin; Humans; Hypoglycemic Agents; Insulin Glargine; Peptides | 2021 |
Effects of liraglutide versus sitagliptin on circulating cardiovascular biomarkers, including circulating progenitor cells, in individuals with type 2 diabetes and obesity: Analyses from the LYDIA trial.
Topics: Adult; Biomarkers; Diabetes Mellitus, Type 2; Dipeptidyl-Peptidase IV Inhibitors; Glucagon-Like Peptide 1; Humans; Hypoglycemic Agents; Liraglutide; Middle Aged; Obesity; Sitagliptin Phosphate; Stem Cells; Vascular Endothelial Growth Factor A | 2021 |
Cardiovascular effectiveness of human-based vs. exendin-based glucagon like peptide-1 receptor agonists: a retrospective study in patients with type 2 diabetes.
Glucagon like peptide-1 (GLP-1) receptor agonists (GLP-1RA) are effective to control type 2 diabetes (T2Ds) and can protect from adverse cardiovascular outcomes. GLP-1RA are based on the human GLP-1 or the exendin-4 sequence. We compared cardiovascular outcomes of patients with T2D who received human-based or exendin-based GLP-1RA in routine clinical practice.. We performed a retrospective study on the administrative database of T2D patients from the Veneto Region (North-East Italy). We identified patients who initiated a human-based or exendin-based GLP-1RA from 2011 to 2018. The primary outcome was occurrence of major adverse cardiovascular events (MACE). Secondary outcomes were individual MACE components, revascularization, hospitalization for heart failure, or for cardiovascular causes. From 330 193 patients with diabetes, 6620 were new users of GLP-1RA. After propensity score matching, we analysed 1098 patients in each group, who were on average 61 years old, 59.5% males, 13% with established cardiovascular disease, had an estimated diabetes duration of 8.4 years, and a baseline HbA1c of 7.9%. During a median follow-up of 18 months, patients treated with human-based GLP-1RA as compared to those treated with exendin-based GLP-1RA, showed lower rates of MACE [hazard ratio 0.61; 95% confidence interval (CI) 0.39-0.95], myocardial infarction (0.51; 95% CI 0.28-0.94), and hospitalization for cardiovascular causes (0.66; 95% CI 0.47-0.92).. We observed better cardiovascular outcomes among patients treated with human-based vs. exendin-based GLP-1RA under routine care. In the absence of comparative trials and in view of the limitations of retrospective studies, this finding provides a moderate level of evidence to guide clinical decision. Topics: Diabetes Mellitus, Type 2; Female; Glucagon-Like Peptide 1; Glucagon-Like Peptide-1 Receptor; Humans; Hypoglycemic Agents; Male; Middle Aged; Myocardial Infarction; Retrospective Studies | 2021 |
GLP-1, SGLT-2, new devices for interventional cardiologists.
Topics: Cardiologists; Diabetes Mellitus, Type 2; Glucagon-Like Peptide 1; Humans | 2021 |
Unlocking the Therapeutic Potential of Glucagon-Like Peptide-1 Analogue and Fibroblast Growth Factor 21 Combination for the Pathogenesis of Atherosclerosis in Type 2 Diabetes.
Topics: Atherosclerosis; Diabetes Mellitus, Type 2; Fibroblast Growth Factors; Glucagon-Like Peptide 1; Humans | 2021 |
Effects of Glucagon-Like Peptide-1 Analogue and Fibroblast Growth Factor 21 Combination on the Atherosclerosis-Related Process in a Type 2 Diabetes Mouse Model.
Glucagon-like peptide-1 (GLP-1) analogues regulate glucose homeostasis and have anti-inflammatory properties, but cause gastrointestinal side effects. The fibroblast growth factor 21 (FGF21) is a hormonal regulator of lipid and glucose metabolism that has poor pharmacokinetic properties, including a short half-life. To overcome these limitations, we investigated the effect of a low-dose combination of a GLP-1 analogue and FGF21 on atherosclerosis-related molecular pathways.. C57BL/6J mice were fed a high-fat diet for 30 weeks followed by an atherogenic diet for 10 weeks and were divided into four groups: control (saline), liraglutide (0.3 mg/kg/day), FGF21 (5 mg/kg/day), and low-dose combination treatment with liraglutide (0.1 mg/kg/day) and FGF21 (2.5 mg/kg/day) (n=6/group) for 6 weeks. The effects of each treatment on various atherogenesisrelated pathways were assessed.. Liraglutide, FGF21, and their low-dose combination significantly reduced atheromatous plaque in aorta, decreased weight, glucose, and leptin levels, and increased adiponectin levels. The combination treatment upregulated the hepatic uncoupling protein-1 (UCP1) and Akt1 mRNAs compared with controls. Matric mentalloproteinase-9 (MMP-9), monocyte chemoattractant protein-1 (MCP-1), and intercellular adhesion molecule-1 (ICAM-1) were downregulated and phosphorylated Akt (p-Akt) and phosphorylated extracellular signal-regulated kinase (p-ERK) were upregulated in liver of the liraglutide-alone and combination-treatment groups. The combination therapy also significantly decreased the proliferation of vascular smooth muscle cells. Caspase-3 was increased, whereas MMP-9, ICAM-1, p-Akt, and p-ERK1/2 were downregulated in the liraglutide-alone and combination-treatment groups.. Administration of a low-dose GLP-1 analogue and FGF21 combination exerts beneficial effects on critical pathways related to atherosclerosis, suggesting the synergism of the two compounds. Topics: Animals; Atherosclerosis; Diabetes Mellitus, Type 2; Fibroblast Growth Factors; Glucagon-Like Peptide 1; Mice; Mice, Inbred C57BL | 2021 |
Bitter Melon Extract Yields Multiple Effects on Intestinal Epithelial Cells and Likely Contributes to Anti-diabetic Functions.
The intestines have been recognized as important tissues for metabolic regulation, including glycemic control, but their vital role in promoting the anti-diabetic effects of bitter melon, the fruit of Topics: Cell Line; Diabetes Mellitus, Type 1; Diabetes Mellitus, Type 2; Enterocytes; Enteroendocrine Cells; Glucagon-Like Peptide 1; Glucose; Humans; Insulin; Insulin Resistance; Intestinal Mucosa; Momordica charantia; Plant Extracts | 2021 |
Factors associated with A1C reduction with GLP-1 agonist or SGLT-2 inhibitor use.
While use of glucagon-like peptide-1 (GLP-1) agonists and sodium-glucose cotransporter-2 (SGLT-2) inhibitors reduces the risk of atherosclerotic cardiovascular disease outcomes and lowers glycosylated haemoglobin (A1C), evidence on patient characteristics associated with clinically relevant A1C reduction is lacking.. The objective of this retrospective cohort study was to identify patient characteristics associated with A1C reduction with initial GLP-1 or SGLT-2 use.. Patients with type 2 diabetes and a baseline A1C ≥7% who were dispensed a GLP-1 or SGLT-2 between 01/01/10 and 12/31/17 were included. Patients were categorized as having a ≥1% or <1% A1C reduction during the 90-365 days after GLP-1/SGLT-2 initiation. Patient characteristics were collected during the 180 days prior to initiation. Multivariable logistic and linear regression modelling was performed to identify characteristics associated with a ≥1% A1C reduction and absolute change in A1C, respectively.. Five hundred and seventy-two patients were included with 261 (46%) and 311 (54%) having and not having an ≥1% A1C reduction. Patients were primarily middle-aged, female, white, non-Hispanic and had a high burden of chronic disease. Characteristics associated with a ≥1% A1C reduction included: GLP-1/SGLT-2 persistence, congestive heart failure comorbidity, phentermine dispensing, care management team (CMT) enrollee and higher baseline A1C. Characteristics associated with absolute A1C reduction included: age, baseline A1C, CMT enrollee, GLP-1/SGLT-2 persistence and a phentermine dispensing.. The results of this study provide practitioners with guidance on the patients who are most likely to have a clinically relevant A1C reduction with GLP-1 or SGLT-2 use. Topics: Diabetes Mellitus, Type 2; Female; Glucagon-Like Peptide 1; Glucagon-Like Peptide-1 Receptor; Glycated Hemoglobin; Humans; Hypoglycemic Agents; Middle Aged; Retrospective Studies; Sodium-Glucose Transporter 2 Inhibitors | 2021 |
The islet's bridesmaid becomes the bride: Proglucagon-derived peptides deliver transformative therapies.
The 2021 Gairdner Prize is awarded to Daniel Drucker, Joel Habener, and Jens Juul Holst for the discovery of novel peptides encoded in the proglucagon sequence and the establishment of their physiological roles. These discoveries underpinned the development of therapeutics that are now benefiting patients with type 2 diabetes and other disorders worldwide. Topics: Diabetes Mellitus, Type 2; Glucagon-Like Peptide 1; Glucagon-Like Peptide 2; Humans; Islets of Langerhans; Proglucagon; Receptors, Glucagon; Short Bowel Syndrome | 2021 |
A real-world comparison of cardiovascular, medical and costs outcomes in new users of SGLT2 inhibitors versus GLP-1 agonists.
To compare SGLT2 inhibitors and GLP-1 agonists on cardiovascular (CV) outcomes, treatment persistence/discontinuation, healthcare utilization and costs.. This retrospective cohort study utilized medical and pharmacy claims to identify new SGLT2 inhibitor or GLP-1 agonist users from January 2015 to June 2017. A total of 5,507 patients were included in each treatment group after 1:1 propensity score matching. Cox proportional hazards models were used to compare CV outcomes and treatment discontinuation. Healthcare utilization and costs were compared using Wilcoxon signed rank test.. No differences in the primary composite CV outcome or secondary CV outcome were observed. Patients using GLP-1 agonists were more likely to discontinue treatment (hazard ratio 1.15, 95% confidence interval 1.10-1.21) and more likely to have an inpatient hospitalization (14.4% vs. 11.9%, P < 0.001) or emergency department visit (27.4% vs. 23.5%, P < 0.001) compared to patients on SGLT2 inhibitors. The average per-person per-month cost difference was +$179 for total cost (P < 0.001), +$70 for medical cost (P < 0.001) and +$108 for pharmacy cost (P < 0.001) for GLP-1 agonists compared to SGLT2 inhibitors.. Differences in composite CV outcomes were not established. However, other findings that favored SGLT2 inhibitors should be weighed against the known risks associated with this therapeutic class. Topics: Adult; Aged; Aged, 80 and over; Cohort Studies; Diabetes Mellitus, Type 2; Female; Glucagon-Like Peptide 1; Humans; Male; Middle Aged; Propensity Score; Retrospective Studies; Sodium-Glucose Transporter 2 Inhibitors; Young Adult | 2021 |
Effect of GLP-1/GLP-1R on the Polarization of Macrophages in the Occurrence and Development of Atherosclerosis.
To investigate the effect of GLP-1/GLP-1R on the polarization of macrophages in the occurrence and development of atherosclerosis.. Totally, 49 patients with coronary heart disease (CHD) and 52 cases of health control (HC) were recruited, all subjects accept coronary angiography gold standard inspection. One or more major coronary arteries (LM, LAD, LCx, and RCA) stenosis degree in 50% of patients as CHD group; the rest of the stenosis less than 50% or not seen obvious stenosis are assigned to the HC group. Flow cytometry were used to detect the percentage of (CD14+) M macrophages, (CD14+CD80+) M1 macrophages, (CD14+CD206+) M2 macrophages, and their surface GLP-1R expression differences in the two groups, using BD cytokine kit to detect the levels of IL-8, IL-1. GLP-1R expression on the surface of total macrophages and M2 macrophages was different between the CHD group and the HC group (. GLP-1R agonist is independent of the hypoglycemic effect of T2DM and has protective effect on cardiovascular system. GLP-1R may regulate the polarization of macrophages toward M2, thus playing a protective role in the progression of coronary atherosclerosis. Topics: Adult; Aged; Cell Polarity; Coronary Artery Disease; Cytokines; Diabetes Mellitus, Type 2; Female; Glucagon-Like Peptide 1; Glucagon-Like Peptide-1 Receptor; Humans; Lipids; Macrophages; Male; Middle Aged | 2021 |
Glucagon-Like Peptide 1 Receptor Agonists and Chronic Lower Respiratory Disease Exacerbations Among Patients With Type 2 Diabetes.
Emerging data from animal and human pilot studies suggest potential benefits of glucagon-like peptide 1 receptor agonists (GLP-1RA) on lung function. We aimed to assess the association of GLP-1RA and chronic lower respiratory disease (CLRD) exacerbation in a population with comorbid type 2 diabetes (T2D) and CLRD.. A new-user active-comparator analysis was conducted with use of a national claims database of beneficiaries with employer-sponsored health insurance spanning 2005-2017. We included adults with T2D and CLRD who initiated GLP-1RA or dipeptidyl peptidase 4 inhibitors (DPP-4I) as an add-on therapy to their antidiabetes regimen. The primary outcome was time to first hospital admission for CLRD. The secondary outcome was a count of any CLRD exacerbation associated with an inpatient or outpatient visit. We estimated incidence rates using inverse probability of treatment weighting for each study group and compared via risk ratios.. The study sample consisted of 4,150 GLP-1RA and 12,540 DPP-4I new users with comorbid T2D and CLRD. The adjusted incidence rate of first CLRD admission during follow-up was 10.7 and 20.3 per 1,000 person-years for GLP-1RA and DPP-4I users, respectively, resulting in an adjusted hazard ratio of 0.52 (95. GLP-1RA users had fewer CLRD exacerbations in comparison with DPP-4I users. Considering both plausible mechanistic pathways and this real-world evidence, potential beneficial effects of GLP-1RA may be considered in selection of an antidiabetes treatment regimen. Randomized clinical trials are warranted to confirm our findings. Topics: Diabetes Mellitus, Type 2; Dipeptidyl-Peptidase IV Inhibitors; Disease Progression; Glucagon-Like Peptide 1; Glucagon-Like Peptide-1 Receptor; Humans; Hypoglycemic Agents | 2021 |
Exploring the GLP-1-GLP-1R axis in porcine pancreas and gastrointestinal tract in vivo by ex vivo autoradiography.
Glucagon-like peptide-1 (GLP-1) increases insulin secretion from pancreatic beta-cells and GLP-1 receptor (GLP-1R) agonists are widely used as treatment for type 2 diabetes mellitus. Studying occupancy of the GLP-1R in various tissues is challenging due to lack of quantitative, repeatable assessments of GLP-1R density. The present study aimed to describe the quantitative distribution of GLP-1Rs and occupancy by endogenous GLP-1 during oral glucose tolerance test (OGTT) in pigs, a species that is used in biomedical research to model humans.. GLP-1R distribution and occupancy were measured in pancreas and gastrointestinal tract by ex vivo autoradiography using the GLP-1R-specific radioligand. High homogenous uptake of. We identified areas with similarities as well as important differences regarding GLP-1R distribution and occupancy in pigs compared with humans. First, there was strong ligand binding in the exocrine pancreas in islets. Second, GLP-1 secretion during OGTT is minimal and GLP-1 might not be an important incretin in pigs under physiological conditions. These findings offer new insights on the relevance of porcine diabetes models. Topics: Animals; Autoradiography; Diabetes Mellitus, Type 2; Gastrointestinal Tract; Glucagon-Like Peptide 1; Pancreas; Swine; Tissue Distribution | 2021 |
Elevation of Fasting GLP-1 Levels in Child and Adolescent Obesity: Friend or Foe?
Glucagon-like peptide-1 (GLP-1) receptor agonists have been gaining much attention as a therapeutic approach to type 2 diabetes and obesity. Stinson et al recently reported that fasting GLP-1 is higher in children and adolescents with overweight/obesity and that it associates with cardiometabolic risk factors in a cross-sectional study comprising more than 4000 subjects. Obvious questions include why fasting GLP-1 is significantly increased in children and adolescents with overweight/obesity and why this is correlated with cardiometabolic risks. It has been shown that the inflammatory cytokine interleukin-6 (IL-6) stimulates GLP-1 secretion from pancreatic α-cells. IL-6-induced GLP-1 secretion could therefore play a role in expanding the β-cell reservoir in compensation for increased insulin needs due to exacerbation of insulin resistance. On the other hand, augmented GLP-1 secretion leads to increased insulin secretion, thereby enhancing hepatic lipogenesis and stimulating adipogenesis, which might underlie the associations of fasting GLP-1 with % body fat, triglycerides, and alanine aminotransferase. It is also possible that GLP-1 levels are naturally increased to oppose body weight gain to maintain body weight. However, it is important to note the differing biological effects of GLP-1 at physiological and pharmacological levels, which are evident in body weight reduction by GLP-1 receptor agonists and DPP-4 inhibitors. The Stinson study clearly demonstrated that fasting GLP-1 associates with overweight/obesity and cardiometabolic risk factors in children and adolescents. However, additional experiments need to be carried out to fully understand the relevance of these observations to human disease and health. Topics: Adolescent; Child; Cross-Sectional Studies; Diabetes Mellitus, Type 2; Fasting; Glucagon-Like Peptide 1; Humans; Pediatric Obesity | 2021 |
Use of glucagon-like peptide-1 receptor agonists for pediatric patients with obesity and diabetes: The providers' perspectives.
Glucagon-like peptide-1 receptor agonists (GLP-1RA) have been widely used in adults with Type 2 diabetes (T2D) and obesity. We sought to evaluate the experience of pediatric endocrinology providers with GLP-1RA and factors that guide them on whether and how to prescribe these medications.. We surveyed the members of the Pediatric Endocrine Society regarding the use of GLP-1RA in their practice.. The respondents (n = 102) were predominantly from academic centers (84%) and 75%reported using GLP-1RA in pediatric patients, mostly to treat T2D and obesity. Patient tolerance for the medication was reported to be the driving factor determining the duration of treatment. Gastrointestinal side effects were observed more commonly than local reactions or elevation of pancreatic enzymes. Lack of clinical experience was reported to be a major barrier for prescribing GLP-1RA, particularly among those with more than 5 years of clinical experience. Finally, liraglutide was used more often (93%) than other GLP-1RA.. The use of GLP-1RA has increased in pediatric patients. Recent Food and Drug Administration approval of liraglutide for pediatric obesity will likely further increase its prescription rate. Providers should be vigilant about side effects and adjust the doses of GLP-1RA accordingly. More efforts should be made by professional societies to educate pediatric endocrinology providers about the proper use of GLP-1RA and enhance their confidence in prescribing these medications. Topics: Adolescent; Child; Diabetes Mellitus, Type 2; Glucagon-Like Peptide 1; Humans; Hypoglycemic Agents; Pediatric Obesity; Practice Patterns, Physicians'; Surveys and Questionnaires; Young Adult | 2021 |
In type 2 diabetes, SGLT2 inhibitors reduce all-cause, but not cardiovascular, mortality vs. GLP-1 RAs.
Palmer SC, Tendal B, Mustafa RA, et al. Topics: Diabetes Mellitus, Type 2; Glucagon-Like Peptide 1; Glucagon-Like Peptide-1 Receptor; Humans; Hypoglycemic Agents; Sodium-Glucose Transporter 2 Inhibitors | 2021 |
Effects of three types of bariatric interventions on myocardial infarct size and vascular function in rats with type 2 diabetes mellitus.
The effects of three types of bariatric interventions on myocardial infarct size were tested in the rat model of type 2 diabetes mellitus (T2DM). We also evaluated the effects of bariatric surgery on no-reflow phenomenon and vascular dysfunction caused by T2DM.. Rats with T2DM were assigned into groups: without surgery, sham-operated, ileal transposition, Roux-en-Y gastric bypass, and sleeve gastrectomy. Oral glucose tolerance, glucagon-like peptide-1, and insulin levels were measured. Six weeks after surgery, the animals were subjected to myocardial ischemia-reperfusion followed by histochemical determination of infarct size (IS), no-reflow zone, and blood stasis area size. Vascular dysfunction was characterized using wire myography.. All bariatric surgery types caused significant reductions in animal body weight and resulted in T2DM compensation. All bariatric interventions partially normalized glucagon-like peptide-1 responses attenuated by T2DM. IS was significantly smaller in animals with T2DM. Bariatric surgery provided no additional IS limitation compared with T2DM alone. Bariatric surgeries reversed T2DM-induced enhanced contractile responses of the mesenteric artery to 5-hydroxytryptamine. Sleeve gastrectomy normalized decreased nitric oxide synthase contribution to the endothelium-dependent vasodilatation in T2DM.. T2DM resulted in a reduction of infarct size and no-reflow zone size. Bariatric surgery provided no additional infarct-limiting effect, but it normalized T2DM-induced augmented vascular contractility and reversed decreased contribution of nitric oxide to endothelium-dependent vasodilatation typical of T2DM. All taken together, we suggest that this type of surgery may have a beneficial effect on T2DM-induced cardiovascular diseases. Topics: Animals; Bariatric Surgery; Blood Glucose; Diabetes Mellitus, Experimental; Diabetes Mellitus, Type 2; Diabetic Angiopathies; Gastric Bypass; Glucagon-Like Peptide 1; Male; Myocardial Infarction; Rats; Rats, Wistar | 2021 |
Smart-watch-programmed green-light-operated percutaneous control of therapeutic transgenes.
Wearable smart electronic devices, such as smart watches, are generally equipped with green-light-emitting diodes, which are used for photoplethysmography to monitor a panoply of physical health parameters. Here, we present a traceless, green-light-operated, smart-watch-controlled mammalian gene switch (Glow Control), composed of an engineered membrane-tethered green-light-sensitive cobalamin-binding domain of Thermus thermophilus (TtCBD) CarH protein in combination with a synthetic cytosolic TtCBD-transactivator fusion protein, which manage translocation of TtCBD-transactivator into the nucleus to trigger expression of transgenes upon illumination. We show that Apple-Watch-programmed percutaneous remote control of implanted Glow-controlled engineered human cells can effectively treat experimental type-2 diabetes by producing and releasing human glucagon-like peptide-1 on demand. Directly interfacing wearable smart electronic devices with therapeutic gene expression will advance next-generation personalized therapies by linking biopharmaceutical interventions to the internet of things. Topics: Animals; Bacterial Proteins; Cell Engineering; Diabetes Mellitus, Type 2; Female; Genetic Engineering; Glucagon-Like Peptide 1; HEK293 Cells; Humans; Light; Male; Mesenchymal Stem Cells; Mice; Mice, Obese; Optogenetics; Photoplethysmography; Protein Domains; Recombinant Fusion Proteins; Thermus thermophilus; Trans-Activators; Transgenes; Wearable Electronic Devices | 2021 |
Hepatoprotective effect of gallic acid against type 2-induced diabetic liver injury in male rats through modulation of fetuin-A and GLP-1 with involvement of ERK1/2/NF-κB and Wnt1/β-catenin signaling pathways.
Gallic acid is a phenolic compound with biological and pharmacological activities. Therefore, our study aimed to examine whether gallic acid has a beneficial effect against type 2-induced diabetic hepatic injury in rats and attempt to discover its possible intracellular pathways. Adult male rats were subdivided into six groups: Control, DM (diabetes mellitus), GA (gallic acid)+DM, DM+GA, DM+MET (metformin) and DM+GA+MET. Type 2 diabetes mellitus (T2DM) induced a significant increase in the blood glucose, HOMA-IR, liver enzymes, fetuin-A, hepatic triglycerides content with diminished serum insulin and hepatic glycogen content associated with impairment of cellular redox balance. Administration of gallic acid successfully restored all these alterations which was confirmed by marked improvement of the histopathological changes of the liver. Significantly, gallic acid increased the expression of glucagon-like peptide-1 (GLP-1) immunoreactive cells in the terminal ileum with negative correlation observed between fetuin-A and GLP-1 cells. Furthermore, our results discovered that gallic acid could diminish the DM-induced hepatic damage via upregulated hepatic mRNA expression of GLUT-4, Wnt1 and β-catenin with inhibitory effects on the elevated expression of ERK1/2/NF-κB. In conclusion, this study suggests that gallic acid provides a significant protection against T2DM-mediated liver injury. The use of gallic acid with traditional anti-diabetic drug enhanced its efficiency compared with traditional drug alone. Topics: alpha-2-HS-Glycoprotein; Animals; beta Catenin; Diabetes Mellitus, Experimental; Diabetes Mellitus, Type 2; Gallic Acid; Glucagon-Like Peptide 1; Liver; Male; MAP Kinase Signaling System; NF-kappa B; Rats; Rats, Wistar; Wnt1 Protein | 2021 |
Impaired Ca
Ca Topics: Alstrom Syndrome; Animals; Blood Glucose; Calcium; Calcium Signaling; Diabetes Mellitus, Type 2; Disease Models, Animal; Endoplasmic Reticulum; Exenatide; Fluorescent Dyes; Fura-2; Glucagon-Like Peptide 1; Hepatocytes; Hypoglycemic Agents; Insulin; Insulin Resistance; Liver; Male; Mice; Mice, Transgenic; Non-alcoholic Fatty Liver Disease; Obesity; Palmitic Acid | 2021 |
The incessant increase curve during oral glucose tolerance tests in Chinese adults with type 2 diabetes and its association with gut hormone levels.
Glucose curve shapes during oral glucose tolerance tests (OGTTs) are mainly classified as incessant increase, monophasic and biphasic. Youth with an incessant increase curve have worse β-cell function. The aim of this paper was to investigate the incessant increase curve in Chinese adults with type 2 diabetes (T2DM), and its association with β-cell function and gut hormone levels. Eighty-nine Chinese patients (59 males and 30 females) were included in this study with a mean age of 50.56 ± 16.00 years. They were all recently diagnosed with T2DM and underwent 180-min OGTTs. Data on demographics, β-cell function, and insulin sensitivity were also collected. Gut hormones, including glucagon-like peptide-1 (GLP-1), glucose-dependent insulinotropic polypeptide (GIP), and ghrelin, were also detected during the OGTT. A total of 39.3 % of subjects had an incessant increase in the glucose response curve, while 59.6 % had a monophasic curve. Because only one curve was classified as biphasic, patients with a biphasic curve were omitted from further research. Lower plasma C-peptide, HOMA2-β, area under the curve (AUC) of C-peptide, and ratio of AUC of insulin to AUC of glucose were found in patients with incessant increase curves compared to those with monophasic curves (P < 0.05). Higher glycated hemoglobin (HbA Topics: Adult; Aged; Asian People; Diabetes Mellitus, Type 2; Female; Gastric Inhibitory Polypeptide; Gastrointestinal Hormones; Ghrelin; Glucagon-Like Peptide 1; Glucose Tolerance Test; Humans; Insulin Resistance; Male; Middle Aged | 2021 |
Another milestone in the evolution of GLP-1-based diabetes therapies.
Topics: Diabetes Mellitus, Type 2; Glucagon-Like Peptide 1; Humans; Hypoglycemic Agents | 2021 |
Persistence of GLP-1 RA in combination with basal insulin among adults with type 2 diabetes in Canada.
The purpose of this study is to assess the persistence of Canadians with Type 2 diabetes mellitus (T2D) on loose-dose combination treatment (i.e., administered by separate devices) with a glucagon-like peptide 1 receptor agonist (GLP-1 RA) and basal insulin over 12 months.. This study is a retrospective cohort study of T2D adults using a Canadian longitudinal prescription database over a 5-year period. Cohort 1 (n = 12,411) is a primary cohort including only individuals inexperienced with the combination therapy at index. Cohort 2 (n = 13,498) is an exploratory cohort and includes everyone regardless of previous experience on the loose-dose combination therapy. The primary endpoint is the proportion of individuals persistent and average days persistent to the loose-dose combination therapy at 12 months in Canada.. In Cohort 1, overall persistence was 47% in the 12-month period post-index. Persistence is similar when including all inexperienced and subsequent loose-dose combination experiences in Cohort 2 (45%).. Canadian T2D adults taking a loose-dose combination therapy of a GLP-1 RA and basal insulin had overall low persistence and lower than reports from previous studies of GLP-1 RA or basal insulin alone. Improving persistence to combination therapy with GLP-1 RA plus basal insulin is an important issue to explore in clinical practice. Topics: Adult; Canada; Diabetes Mellitus, Type 2; Glucagon-Like Peptide 1; Glucagon-Like Peptide-1 Receptor; Glycated Hemoglobin; Humans; Hypoglycemic Agents; Insulin; Retrospective Studies | 2021 |
Holdemanella biformis improves glucose tolerance and regulates GLP-1 signaling in obese mice.
Impaired glucose homeostasis in obesity is mitigated by enhancing the glucoregulatory actions of glucagon-like peptide 1 (GLP-1), and thus, strategies that improve GLP-1 sensitivity and secretion have therapeutic potential for the treatment of type 2 diabetes. This study shows that Holdemanella biformis, isolated from the feces of a metabolically healthy volunteer, ameliorates hyperglycemia, improves oral glucose tolerance and restores gluconeogenesis and insulin signaling in the liver of obese mice. These effects were associated with the ability of H. biformis to restore GLP-1 levels, enhancing GLP-1 neural signaling in the proximal and distal small intestine and GLP-1 sensitivity of vagal sensory neurons, and to modify the cecal abundance of unsaturated fatty acids and the bacterial species associated with metabolic health. Our findings overall suggest the potential use of H biformis in the management of type 2 diabetes in obesity to optimize the sensitivity and function of the GLP-1 system, through direct and indirect mechanisms. Topics: Animals; Blood Glucose; Diabetes Mellitus, Type 2; Disease Models, Animal; Firmicutes; Glucagon-Like Peptide 1; Gluconeogenesis; Glucose; Glucose Tolerance Test; Hyperglycemia; Insulin; Mice; Mice, Inbred C57BL; Mice, Obese; Obesity | 2021 |
Molecular insights into ago-allosteric modulation of the human glucagon-like peptide-1 receptor.
The glucagon-like peptide-1 (GLP-1) receptor is a validated drug target for metabolic disorders. Ago-allosteric modulators are capable of acting both as agonists on their own and as efficacy enhancers of orthosteric ligands. However, the molecular details of ago-allosterism remain elusive. Here, we report three cryo-electron microscopy structures of GLP-1R bound to (i) compound 2 (an ago-allosteric modulator); (ii) compound 2 and GLP-1; and (iii) compound 2 and LY3502970 (a small molecule agonist), all in complex with heterotrimeric G Topics: Animals; Binding Sites; Cell Line; CHO Cells; Cricetulus; Cryoelectron Microscopy; Diabetes Mellitus, Type 2; Enzyme Activation; Glucagon-Like Peptide 1; Glucagon-Like Peptide-1 Receptor; Glucagon-Like Peptides; HEK293 Cells; Humans; Molecular Dynamics Simulation; Protein Conformation; Sf9 Cells; Spodoptera | 2021 |
Uptake of new antidiabetic medicines in 11 European countries.
Several new antidiabetic medicines (GLP-1 receptor agonists, DPP-4 inhibitors, and SGLT-2 inhibitors) have been approved by the European Medicines Agency since 2006. The aim of this study was to evaluate the uptake of new antidiabetic medicines in European countries over a 10-year period.. The study used IQVIA quarterly value and volume sales data January 2006-December 2016. The market uptake of new antidiabetic medicines together with intensity of prescribing policy for all antidiabetic medicines were estimated for Austria, Croatia, France, Germany, Hungary, Italy, Poland, Slovenia, Spain, Sweden, and the United Kingdom. The following measures were determined: number of available new active substances, median time to first continuous use, volume market share, and annual therapy cost.. All countries had at least one new antidiabetic medicine in continuous use and an increase in intensity of prescribing policy for all antidiabetic medicines was observed. A tenfold difference in median time to first continuous use (3-30 months) was found. The annual therapy cost in 2016 of new antidiabetic medicines ranged from EUR 363 to EUR 769. Among new antidiabetic medicines, the market share of DPP-4 inhibitors was the highest. Countries with a higher volume market share of incretin-based medicines (Spain, France, Austria, and Germany) in 2011 had a lower increase in intensity of prescribing policy. This kind of correlation was not found in the case of SGLT-2 inhibitors.. This study found important differences and variability in the uptake of new antidiabetic medicines in the included countries. Topics: Databases, Factual; Diabetes Mellitus, Type 2; Dipeptidyl-Peptidase IV Inhibitors; Drug Approval; Europe; Glucagon-Like Peptide 1; Humans; Hypoglycemic Agents; Sodium-Glucose Transporter 2 Inhibitors | 2021 |
Type 2 Diabetes Medication and Cardiovascular Benefits.
Diabetes mellitus remains one of the most common and disabling diseases in the world. Patients with diabetes tend to have more cardiovascular complications, regardless of their prior cardiac history. Tight glycemic control has been shown to prevent microvascular complications as it relates to nephropathy and retinopathy; however, it hasn't been proven beneficial in patients with macrovascular diseases, i.e., cardiovascular disease. In fact, two groups of diabetic medications, dual peroxisome-proliferator-activated receptor - agonists and sulfonylurea, are known to worsen cardiovascular disease. Patients using this group of medications have shown increased heart failure readmission rates and increased risk for cardiovascular death. Insulin and Metformin have been the gold standard treatment for diabetes management to prevent worsening cardiac outcomes, and now a newer class of medications have demonstrated similar results. These drug classes includes sodium glucose cotransporter 2(SGLT 2) inhibitors, dipeptidyl peptidase-4 (DPP-4) inhibitors, and glucagon like peptide-1 (GLP 1) analogues. Topics: Cardiovascular Diseases; Diabetes Mellitus, Type 2; Dipeptidyl-Peptidase IV Inhibitors; Glucagon-Like Peptide 1; Humans; Hypoglycemic Agents; Sodium-Glucose Transporter 2 Inhibitors | 2021 |
Whey protein preload enhances the active GLP-1 response and reduces circulating glucose in women with polycystic ovarian syndrome.
Polycystic ovary syndrome (PCOS) increases risk for development of type 2 diabetes. Whey protein ingestion before a carbohydrate load attenuates blood glucose. For our exploratory, case-control study design, we hypothesized that 35 g whey protein isolate (WPI) preloading would increase postprandial incretins and reduce hyperglycemia in women with PCOS. Twenty-nine age-matched women (PCO = 14 and CON = 15) completed oral glycemic tolerance tests (OGTT) following baseline (Day 0) as well as 35 g WPI acute (Day 1) and short-term supplementation (Day 7). Eight venous samples were collected during each test for quantification of glucose, and enteropancreatic hormones and to calculate area under the curve (AUC). Data was analyzed via repeated measures ANCOVA with significance set at P< .05. "Day x time x group" significantly influenced glucose (P = .01) and insulin changes (P = .03). In both groups, AUC Topics: Adolescent; Adult; Analysis of Variance; Area Under Curve; Blood Glucose; Case-Control Studies; Diabetes Mellitus, Type 2; Dietary Proteins; Dietary Supplements; Female; Glucagon; Glucagon-Like Peptide 1; Glucose Tolerance Test; Humans; Hyperglycemia; Incretins; Insulin; Polycystic Ovary Syndrome; Postprandial Period; Whey Proteins; Young Adult | 2021 |
A method for constructing GLP-1 overexpression intestinal organoids.
As a potent insulinotrophic hormone, glucagon-like peptide 1 (GLP-1) is mainly secreted by intestinal L cells, which can effectively promote the release of insulin and thus reduce blood glucose. Therefore, GLP-1 and its analogs have a good prospect in the treatment of type 2 diabetes. In this study, we constructed mouse intestinal organoids that overexpress GLP-1 by optimizing the GLP-1 lentivirus infection method. We found that supernatants secreted by the GLP-1 overexpression organoids effectively enhanced glucose tolerance in wild-type and diabetic mouse. Thus, the GLP-1 overexpression organoids built in this study may provide a novel strategy for the treatment of type 2 diabetes.. 胰高血糖素样肽1 (glucagon-like peptide 1, GLP-1)作为一种肠促胰岛素,主要由肠道L细胞分泌,由于其能够有效促进胰岛素的释放从而降低血糖,因此GLP-1及其类似物在2型糖尿病的治疗上具有良好的应用前景。本研究优化了慢病毒感染类器官的方法,利用该方法成功构建了GLP-1过表达的小鼠小肠类器官(organoids)。结果显示该类器官分泌的GLP-1能够有效地提高野生型及糖尿病小鼠的葡萄糖耐受能力。因此,本研究构建的GLP-1过表达类器官可以为2型糖尿病的治疗提供一种新的策略。. Topics: Animals; Blood Glucose; Diabetes Mellitus, Type 2; Glucagon; Glucagon-Like Peptide 1; Insulin; Mice; Organoids | 2021 |
Comment on Albogami et al. Glucagon-Like Peptide 1 Receptor Agonists and Chronic Lower Respiratory Disease Exacerbations Among Patients With Type 2 Diabetes. Diabetes Care 2021;44:1344-1352.
Topics: Diabetes Mellitus, Type 2; Disease Progression; Glucagon-Like Peptide 1; Glucagon-Like Peptide-1 Receptor; Humans; Hypoglycemic Agents | 2021 |
Once-weekly subcutaneous semaglutide treatment for persons with type 2 diabetes: Real-world data from a diabetes out-patient clinic.
The once-weekly administered glucagon-like peptide 1 (GLP-1) receptor agonist (GLP-1RA) semaglutide, has, in clinical trials, demonstrated significant reductions in glycated haemoglobin A. We observed effects of semaglutide once weekly on HbA Topics: Aged; Diabetes Mellitus, Type 2; Drug Administration Schedule; Female; Glucagon-Like Peptide 1; Glucagon-Like Peptides; Glycated Hemoglobin; Humans; Injections, Subcutaneous; Male; Middle Aged; Outpatients; Retrospective Studies; Treatment Outcome | 2021 |
Slow digestion-oriented dietary strategy to sustain the secretion of GLP-1 for improved glucose homeostasis.
Dysregulated glucose metabolism is associated with many chronic diseases such as obesity and type 2 diabetes mellitus (T2DM), and strategies to restore and maintain glucose homeostasis are essential to health. The incretin hormone of glucagon-like peptide-1 (GLP-1) is known to play a critical role in regulating glucose homeostasis and dietary nutrients are the primary stimuli to the release of intestinal GLP-1. However, the GLP-1 producing enteroendocrine L-cells are mainly distributed in the distal region of the gastrointestinal tract where there are almost no nutrients to stimulate the secretion of GLP-1 under normal situations. Thus, a dietary strategy to sustain the release of GLP-1 was proposed, and the slow digestion property and dipeptidyl peptidase IV (DPP-IV) inhibitory activity of food components, approaches to reduce the rate of food digestion, and mechanisms to sustain the release of GLP-1 were reviewed. A slow digestion-oriented dietary approach through encapsulation of nutrients, incorporation of viscous dietary fibers, and enzyme inhibitors of phytochemicals in a designed whole food matrix will be implemented to efficiently reduce the digestion rate of food nutrients, potentiate their distal deposition and a sustained secretion of GLP-1, which will be beneficial to improved glucose homeostasis and health. Topics: Diabetes Mellitus, Type 2; Digestion; Glucagon-Like Peptide 1; Glucose; Homeostasis; Humans | 2021 |
A GLP-1/GIP Dual Receptor Agonist DA4-JC Effectively Attenuates Cognitive Impairment and Pathology in the APP/PS1/Tau Model of Alzheimer's Disease.
Alzheimer's disease (AD) is a degenerative disorder, accompanied by progressive cognitive decline, for which there is no cure. Recently, the close correlation between AD and type 2 diabetes mellitus (T2DM) has been noted, and a promising anti-AD strategy is the use of anti-T2DM drugs.. To investigate if the novel glucagon-like peptide-1 (GLP-1)/glucose-dependent insulinotropic polypeptide (GIP) receptor agonist DA4-JC shows protective effects in the triple APP/PS1/tau mouse model of AD.. A battery of behavioral tests were followed by in vivo recording of long-term potentiation (LTP) in the hippocampus, quantified synapses using the Golgi method, and biochemical analysis of biomarkers.. DA4-JC improved cognitive impairment in a range of tests and relieved pathological features of APP/PS1/tau mice, enhanced LTP in the hippocampus, increased numbers of synapses and dendritic spines, upregulating levels of post-synaptic density protein 95 (PSD95) and synaptophysin (SYP), normalized volume and numbers of mitochondria and improving the phosphatase and tensin homologue induced putative kinase 1 (PINK1) - Parkin mitophagy signaling pathway, while downregulating amyloid, p-tau, and autophagy marker P62 levels.. DA4-JC is a promising drug for the treatment of AD. Topics: Alzheimer Disease; Animals; Cognitive Dysfunction; Diabetes Mellitus, Type 2; Disease Models, Animal; Disks Large Homolog 4 Protein; Female; Glucagon-Like Peptide 1; Hippocampus; Humans; Long-Term Potentiation; Male; Mice; Mice, Inbred C57BL; Mice, Transgenic; Neuroprotective Agents; Synapses | 2021 |
GLP-1 and GIP receptor agonists in the treatment of Parkinson's disease: Translational systematic review and meta-analysis protocol of clinical and preclinical studies.
Parkinson's disease (PD) is a progressive multifactorial neurodegenerative condition. Epidemiological studies have shown that patients with type 2 diabetes mellitus (T2DM2) are at increased risk for developing PD, indicating a possible insulin-modulating role in this latter condition. We hypothesized that drugs similar to glucagon-like peptide-1 (GLP-1) and gastric inhibitory polypeptide (GIP), used in the treatment of T2DM2, may play a role in PD.. The purpose of this study is to systematically review and meta-analyze data of preclinical and clinical studies evaluating the efficacy and safety of GLP-1 and GIP drugs in the treatment of PD.. Two reviewers will independently evaluate the studies available in the Ovid Medline, Ovid Embase, Web of Science, Cochrane Central Register of Controlled Trials, Cinahl, and Lilacs databases. Preclinical rodent or non-human primate studies and randomized controlled human clinical trials will be included, without language or publication period restrictions. Outcomes of interest in preclinical studies will be primarily locomotor improvements and adverse effects in animal models of PD. For clinical trials, we will evaluate clinical improvements rated by the Movement Disorders Society Unified Parkinson's Disease Rating Scale-parts I, II, III, and IV, and adverse effects. The risk of bias of preclinical studies will be assessed by the SYRCLE tool and CAMARADES checklist and the clinical studies by the Cochrane tool; the certainty of the evidence will be rated by GRADE.. There is an urge for new PD treatments that may slow the progression of the disease rather than just restoring dopamine levels. This study will comprehensively review and update the state of the art of what is known about incretin hormones and PD and highlight the strengths and limitations of translating preclinical data to the clinic whenever possible.. PROSPERO registration number CRD42020223435. Topics: Diabetes Mellitus, Type 2; Disease Progression; Dopamine; Glucagon-Like Peptide 1; Glucagon-Like Peptide-1 Receptor; Humans; Insulin; Meta-Analysis as Topic; Parkinson Disease; Systematic Reviews as Topic | 2021 |
The Human and Mouse Islet Peptidome: Effects of Obesity and Type 2 Diabetes, and Assessment of Intraislet Production of Glucagon-like Peptide-1.
To characterize the impact of metabolic disease on the peptidome of human and mouse pancreatic islets, LC-MS was used to analyze extracts of human and mouse islets, purified mouse alpha, beta, and delta cells, supernatants from mouse islet incubations, and plasma from patients with type 2 diabetes. Islets were obtained from healthy and type 2 diabetic human donors, and mice on chow or high fat diet. All major islet hormones were detected in lysed islets as well as numerous peptides from vesicular proteins including granins and processing enzymes. Glucose-dependent insulinotropic peptide (GIP) was not detectable. High fat diet modestly increased islet content of proinsulin-derived peptides in mice. Human diabetic islets contained increased content of proglucagon-derived peptides at the expense of insulin, but no evident prohormone processing defects. Diabetic plasma, however, contained increased ratios of proinsulin and des-31,32-proinsulin to insulin. Active GLP-1 was detectable in human and mouse islets but 100-1000-fold less abundant than glucagon. LC-MS offers advantages over antibody-based approaches for identifying exact peptide sequences, and revealed a shift toward islet insulin production in high fat fed mice, and toward proglucagon production in type 2 diabetes, with no evidence of systematic defective prohormone processing. Topics: Animals; Diabetes Mellitus, Type 2; Glucagon; Glucagon-Like Peptide 1; Humans; Insulin; Islets of Langerhans; Mice; Obesity | 2021 |
[Potentiation of weight reduction with GLP-1 receptor agonists].
Glucagon-like peptide-1 receptor agonists are the antidiabetic agents that are associated with the greatest weight loss beyond a marked reduction in glycated haemoglobin. Weight loss results from a reduction in appetite through a predominant central effect combined with a peripheral effect. Liraglutide and semaglutide are developed for the treatment of obesity, independently of type 2 diabetes. Three approaches may be considered to potentiate weight loss: an increase of the drug dosage because of the demonstration of a dose-response, an add-on therapy with a sodium-glucose cotransporter type 2 inhibitor as this agent exerts a complementary action through urinary calorie loss (glucosuria) or a combination of the effects of two incretin hormones (GLP-1 and GIP), as the potent dual agonist tirzepatide currently in development.. Les agonistes des récepteurs du glucagon-like peptide-1 (GLP-1) sont les agents antidiabétiques qui, outre une baisse importante du taux d’hémoglobine glyquée, offrent la perte pondérale la plus marquée, en augmentant la satiété par un effet central, prédominant et périphérique. Le liraglutide et le sémaglutide sont développés pour le traitement de l’obésité, indépendamment de la présence d’un diabète de type 2. Trois approches sont possibles pour potentialiser la perte de poids: augmenter la posologie, compte tenu de l’existence d’une relation dose-réponse, ajouter un inhibiteur des sodium-glucose cotransporteurs 2 qui exerce un effet complémentaire grâce à une fuite calorique urinaire (glucosurie), ou encore combiner les effets de deux hormones incrétines (GLP-1 et Glucose-dependent Insulin Releasing Polypeptide), comme avec le puissant double agoniste tirzépatide en développement. Topics: Diabetes Mellitus, Type 2; Glucagon-Like Peptide 1; Glucagon-Like Peptide-1 Receptor; Humans; Pharmaceutical Preparations; Weight Loss | 2021 |
Glucagon-like peptide-1 receptor controls exocytosis in chromaffin cells by increasing full-fusion events.
Agonists for glucagon-like-peptide-1 receptor (GLP-1R) are currently used for the treatment of type 2 diabetes and obesity. Their benefits have been centered on pancreas and hypothalamus, but their roles in other organ systems are not well understood. We studied the action of GLP-1R on secretions of adrenal medulla. Exendin-4, a synthetic analog of GLP-1, increases the synthesis and the release of catecholamines (CAs) by increasing cyclic AMP (cAMP) production, without apparent participation of cAMP-regulated guanine nucleotide exchange factor (Epac). Exendin-4, when incubated for 24 h, increases CA synthesis by promoting the activation of tyrosine hydroxylase. Short incubation (20 min) increases the quantum size of exocytotic events by switching exocytosis from partial to full fusion. Our results give a strong support to the role of GLP-1 in the fine control of exocytosis. Topics: Animals; Chromaffin Cells; Cyclic AMP; Diabetes Mellitus, Type 2; Exenatide; Exocytosis; Glucagon-Like Peptide 1; Glucagon-Like Peptide-1 Receptor; Guanine Nucleotide Exchange Factors; Islets of Langerhans; Rats; Receptors, Glucagon | 2021 |
Glucose-lowering drug use and new-onset atrial fibrillation in patients with diabetes mellitus.
Topics: Aged; Aged, 80 and over; Atrial Fibrillation; Diabetes Mellitus, Type 1; Diabetes Mellitus, Type 2; Dipeptidyl-Peptidase IV Inhibitors; Female; Glucagon-Like Peptide 1; Humans; Hypoglycemic Agents; Insulin; Male; Metformin; Middle Aged; Risk Assessment; Sulfonylurea Compounds | 2021 |
Generation of novel long-acting GLP-1R agonists using DARPins as a scaffold.
Glucagon-like peptide-1 (GLP-1) has been considered to be a promising peptide for treatment of type 2 diabetes mellitus (T2DM). However, the extremely short half-life (minutes) of native GLP-1 limits its clinical application potential. Here, we designed two GLP-1 analogues by genetic fusion of GLP-1 to one or two tandem human serum albumin-binding designed ankyrin repeat proteins (DARPins), denoted as GLP-DARPin or GLP-2DARPin. The two DARPin-fusion GLP-1 proteins were expressed in E. coli and purified, followed by measurements of their bioactivities and half-lives in mice. The results revealed that the half-life of GLP-2DARPin, binding two HSA molecules, was approximately 3-fold longer than GLP-DARPin (52.3 h versus 18.0 h). In contrast, the bioactivity results demonstrated that the blood glucose-lowering effect of GLP-DARPin was more potent than that of GLP-2DARPin. The oral glucose tolerance tests indicated that blood glucose levels were significantly reduced for at least 48 h by GLP-DARPin, but were reduced for only 24 h by GLP-2DARPin. Injected once every two days, GLP-DARPin substantially reduced blood glucose levels in streptozotocin (STZ)-induced diabetic mice to the same levels as normal mice. During the treatment course, GLP-DARPin significantly reduced the food intake and body weight of diabetic mice up to approximately 17% compared with the control group. A histological analysis revealed that GLP-DARPin alleviated islet loss in diabetic mice. These findings suggest that long-acting GLP-DARPin holds great potential for further development into drugs for the treatment of T2DM and obesity. Meanwhile, our data indicate that albumin-binding DARPins can be used as a universal scaffold to improve the pharmacokinetic profiles and pharmacological activities of therapeutic peptides and proteins. Topics: Animals; Diabetes Mellitus, Experimental; Diabetes Mellitus, Type 2; Escherichia coli; Glucagon-Like Peptide 1; Hypoglycemic Agents; Mice | 2021 |
Novel strategy for oral peptide delivery in incretin-based diabetes treatment.
To fulfil an unmet therapeutic need for treating type 2 diabetes by developing an innovative oral drug delivery nanosystem increasing the production of glucagon-like peptide-1 (GLP-1) and the absorption of peptides into the circulation.. We developed a nanocarrier for the oral delivery of peptides using lipid-based nanocapsules. We encapsulated the GLP-1 analogue exenatide within nanocapsules and investigated in vitro in human L-cells (NCl-H716) and murine L-cells (GLUTag cells) the ability of the nanosystem to trigger GLP-1 secretion. The therapeutic relevance of the nanosystem in vivo was tested in high-fat diet (HFD)-induced diabetic mice following acute (one administration) or chronic treatment (5 weeks) in obese and diabetic mice.. We demonstrated that this innovative nanosystem triggers GLP-1 secretion in both human and murine cells as well as in vivo in mice. This strategy increases the endogenous secretion of GLP-1 and the oral bioavailability of the GLP-1 analogue exenatide (4% bioavailability with our nanosystem).The nanosystem synergizes its own biological effect with the encapsulated GLP-1 analogue leading to a marked improvement of glucose tolerance and insulin resistance (acute and chronic). The chronic treatment decreased diet-induced obesity, fat mass, hepatic steatosis, together with lower infiltration and recruitment of immune cell populations and inflammation.. We developed a novel nanosystem compatible with human use that synergizes its own biological effect with the effects of increasing the bioavailability of a GLP-1 analogue. The effects of the formulation were comparable to the results observed for the marketed subcutaneous formulation. This nanocarrier-based strategy represents a novel promising approach for oral peptide delivery in incretin-based diabetes treatment. Topics: Administration, Oral; Analysis of Variance; Animals; Diabetes Mellitus, Experimental; Diabetes Mellitus, Type 2; Drug Administration Schedule; Drug Carriers; Exenatide; Glucagon-Like Peptide 1; Humans; Hypoglycemic Agents; Incretins; Insulin Secretion; Male; Mice; Nanocapsules; Random Allocation; Treatment Outcome | 2020 |
Role of incretin-based therapy in hospitalized patients with type 2 diabetes.
Evidence about the treatment of hospitalized type 2 diabetes patients with incretin-based therapy has emerged in the past 15 years. Based on this evidence, dipeptidyl peptidase-4 inhibitors should be considered for hospitalized patients with type 2 diabetes and an algorithm for this is proposed. In relation to use of glucagon-like peptide-1 and glucagon-like peptide-1 receptor agonist, further research is required to help define their role in the inpatient setting. Topics: Diabetes Mellitus, Type 2; Dipeptidyl-Peptidase IV Inhibitors; Disease Management; Glucagon-Like Peptide 1; Glucagon-Like Peptide-1 Receptor; Hospitalization; Humans; Incretins; Treatment Outcome | 2020 |
Anti-hyperglycemic and anti-hyperlipidemic effects of a special fraction of Luohanguo extract on obese T2DM rats.
Luohanguo (LHG), a traditional Chinese medicine, could clear heat, moisten the lung, soothe the throat, restore the voice, and lubricate intestine and open the bowels. LHG has been utilized for the treatment of sore throats and hyperglycemia in folk medicine as a homology of medicine and food. The hypoglycemic pharmacology of LHG has attracted considerable attention, and mogrosides have been considered to be active ingredients against diabetes mellitus. We have found that these mogrosides could be metabolized into their secondary glycosides containing 1-3 glucose residues in type 2 diabetes mellitus (T2DM) rats in previous studies. These metabolites may be the antidiabetic components of LHG in vivo. Thus far, no reports have been found on reducing blood glucose of mogrosides containing 1-3 glucose residues.. The aim of this study was to confirm that mogrosides containing 1-3 glucose residues were the active components of LHG for antidiabetic effects and to understand their potential mechanisms of action.. First, the special fraction of mogrosides containing 1-3 glucose residues was separated from a 50% ethanol extract of LHG, and the chemical components were identified by ultra-performance liquid chromatography (UPLC) and named low-polar Siraitia grosvenorii glycosides (L-SGgly). Second, the antidiabetic effects of L-SGgly were evaluated by HFD/STZ-induced (high-fat diet and streptozocin) obese T2DM rats by indexing fasting blood glucose (FBG), fasting insulin (FINS), and insulin resistance, and then compared with other fractions in the separation process. The changes in serum lipid levels were also detected. Finally, possible mechanisms of antidiabetic activity of L-SGgly were identified as increasing GLP-1 levels and activating liver AMPK in T2DM rats.. The chemical analysis of L-SGgly showed that they contain 11-oxomogroside V, mogroside V, mogroside III, mogroside IIE, mogroside IIIA. L-SGgly, fractions separated from LHG extract, were verified to have obvious anti-hyperglycemic and anti-hyperlipidemic effects on T2DM rats. Furthermore, L-SGgly regulated insulin secretion in T2DM rats by increasing GLP-1 levels. These findings provide an explanation for the antidiabetic role of LHG. Topics: Administration, Oral; Animals; Blood Glucose; Chemical Fractionation; Cucurbitaceae; Diabetes Mellitus, Experimental; Diabetes Mellitus, Type 2; Diet, High-Fat; Drugs, Chinese Herbal; Glucagon-Like Peptide 1; Glycosides; Humans; Hypoglycemic Agents; Hypolipidemic Agents; Insulin; Lipid Metabolism; Male; Obesity; Rats; Streptozocin; Triterpenes | 2020 |
In silico screening of potential antidiabetic phytochemicals from Phyllanthus emblica against therapeutic targets of type 2 diabetes.
Phyllanthus emblica Linn. (Syn. Emblica officinalis Gaertn.), has been used to cure many ailments of human beings. Literature survey demonstrates that it has many pharmacological activities i.e. antidiabetic, antioxidant, anti-microbial, antifungal, antiallergic, antiviral, and anticancer properties.. The present study aimed to identify the novel plant-derived antidiabetic compounds from P. emblica to understand the molecular basis of antidiabetic activities.. Text mining analysis of P. emblica and its disease association was carried out using server DLAD4U. Due to the highest score of P. emblica with diabetes, the virtual screening of a phytochemical library of P. emblica against three targets of diabetes was carried out. After that FAF-Drug4, admetSAR and DruLiTo servers were used for drug-likeness prediction. Additionally, pharmacophore modeling was also carried out to understand the antidiabetic activity of screened compounds.. The docking scores, drug-likeness and pharmacophore studies found that Ellagic acid, Estradiol, Sesamine, Kaempferol, Zeatin, Quercetin, and Leucodelphinidin are potential antidiabetic compounds.. Our study shows that phytochemicals of P. emblica are very potential antidiabetic candidates. Using the modern techniques these molecules could be used to develop an effective antidiabetic drugs from a natural resource. Topics: Computer Simulation; Diabetes Mellitus, Type 2; Glucagon-Like Peptide 1; Humans; Hypoglycemic Agents; Models, Biological; Molecular Docking Simulation; Phyllanthus emblica; Phytochemicals; Phytotherapy; PPAR gamma; Sodium-Glucose Transporter 2 | 2020 |
A sea cucumber (Holothuria leucospilota) polysaccharide improves the gut microbiome to alleviate the symptoms of type 2 diabetes mellitus in Goto-Kakizaki rats.
Diabetes mellitus has become a worldwide concern in recent years. In this study, the effect of Holothuria leucospilota polysaccharide (HLP) on type 2 diabetes mellitus (T2DM) was investigated in Goto-Kakizaki (GK) rats. The results showed that HLP significantly improved glucose intolerance and regulated blood lipid and hormone levels (p < 0.05). Pathological analysis showed that HLP repaired the impairments of the pancreas and colon in diabetic rats. In addition, a high dose of HLP (200 mg/kg) significantly upregulated the gene expression of peroxisome proliferator-activated receptor-α (PPAR-α), peroxisome proliferator-activated receptor-γ (PPAR-γ), phosphoinositide 3-kinase (PI3K), protein kinase B (PKB/AKT), glucose transporter-4 (GLUT4) and anti-apoptotic (Bcl-2), and downregulated the mRNA levels of pro-apoptotic (Bax) and cluster of differentiation 36 (CD36) in diabetic rats (p < 0.05). Furthermore, HLP treatment increased the short-chain fatty acid-producing bacteria and decreased the opportunistic bacterial pathogen in the feces of diabetic rats. These results demonstrated that HLP has the potential to ameliorate T2DM in GK rats. Topics: Adiponectin; Animals; Blood Glucose; Diabetes Mellitus, Experimental; Diabetes Mellitus, Type 2; Gastrointestinal Microbiome; Glucagon-Like Peptide 1; Insulin; Leptin; Lipids; Male; Peroxisome Proliferator-Activated Receptors; Phosphatidylinositol 3-Kinases; Polysaccharides; Proto-Oncogene Proteins c-akt; Rats; Sea Cucumbers; Signal Transduction | 2020 |
Pharmacological potential of novel agonists for FFAR4 on islet and enteroendocrine cell function and glucose homeostasis.
To investigate the metabolic effects of FFAR4-selective agonists on islet and enteroendocrine cell hormone release and the combined therapeutic effectiveness with DPP-IV inhibitors.. Insulinotropic activity and specificity of FFAR4 agonists were determined in clonal pancreatic BRIN-BD11 cells. Expression of FFAR4 was assessed by qPCR and western blotting following agonist treatment in BRIN-BD11 cells and by immunohistochemistry in mouse islets. Acute in-vivo effects of agonists was investigated after intraperitoneal (i.p.) or oral administration in lean and HFF-obese diabetic mice.. Specific FFAR4 agonism improves glucose tolerance through insulin and incretin secretion, with enhanced DPP-IV inhibition in combination with Sitagliptin.. These findings have for the first time demonstrated that selective FFAR4 activation regulates both islet and enteroendocrine hormone function with agonist combinational therapy, presenting a promising strategy for the treatment of type-2-diabetes. Topics: Aniline Compounds; Animals; Blood Glucose; Diabetes Mellitus, Experimental; Diabetes Mellitus, Type 2; Enteroendocrine Cells; Glucagon-Like Peptide 1; Glucose; Homeostasis; Hypoglycemic Agents; Insulin; Insulin-Secreting Cells; Male; Mice; Receptors, G-Protein-Coupled; Sulfonamides | 2020 |
DR10601, a novel recombinant long-acting dual glucagon-like peptide-1 and glucagon receptor agonist for the treatment of obesity and type 2 diabetes mellitus.
Both glucagon-like peptide-1 (GLP-1) and glucagon (GCG) belong to the incretin family. This study aimed to investigate the pharmacokinetics and pharmacodynamics of DR10601, a fully recombinant hybrid peptide with dual GLP-1/GCG receptor agonistic activity.. The agonistic ability of DR10601 was indirectly assessed by inducing cAMP accumulation in Chinese hamster ovary cells transfected with GLP-1R or GCGR in vitro. Following s.c. administration, the plasma pharmacokinetics of DR10601 were analysed in male Sprague-Dawley rats. The antiobesity effects and improved glycaemic control of DR10601 in vivo were evaluated by administering DR10601 to high-fat DIO mice and ICR mice as a single dose or repeated s.c. doses once every 4 days for 24 days.. DR10601 exhibits dual agonistic activity on GLP-1 and glucagon receptors. The plasma half-life of DR10601 in Sprague-Dawley rats following s.c. administration was 51.9 ± 12.2 h. In an IPGTT, a single s.c. dose of DR10601 (30 nmol/kg) produced similar glycaemic control effects and a longer duration of action compared to dulaglutide (10 nmol/kg). Compared with that achieved with liraglutide (40 nmol/kg) s.c. administered daily, DR10601 administered s.c. once every 4 days at 90 nmol/kg exerted a nearly equivalent effect on food intake and significantly reduced the body weights of high-fat DIO mice at 24 days.. Repeated administration of DR1060 provides potent and sustained glycemic control and body weight loss effect in high-fat DIO mice. DR10601 is a promising long-acting agent deserving further investigation for the treatment of type 2 diabetes and obesity. Topics: Animals; Anti-Obesity Agents; Blood Glucose; Diabetes Mellitus, Type 2; Glucagon-Like Peptide 1; Glucagon-Like Peptides; Humans; Hypoglycemic Agents; Immunoglobulin Fc Fragments; Liraglutide; Male; Mice; Obesity; Rats; Rats, Sprague-Dawley; Receptors, Glucagon; Recombinant Fusion Proteins | 2020 |
The role of linagliptin, a selective dipeptidyl peptidase-4 inhibitor, in the morphine rewarding effects in rats.
Linagliptin is a selective dipeptidyl peptidase-4 (DPP-4) inhibitor which suppresses the rapid degradation of endogenous glucagon-like peptide-1 (GLP-1). In clinical practice, it is used as an antidiabetic drug, but recent studies have confirmed its role in the activity of the central nervous system (CNS). The reported study focused on the role of linagliptin (10 and 20 mg/kg, ip) in the morphine rewarding effect, analyzing how the agent had influenced the conditioned place preference (CPP) in rats via the expression, acquisition, extinction and reinstatement of the morphine rewarding effect. The obtained results clearly demonstrated linagliptin to inhibit the expression and acquisition, to accelerate the extinction and, eventually, to reduce the reinstatement of morphine-induced CPP. The undertaken experiments significantly extended our knowledge on the mechanisms behind the morphine rewarding effect. Topics: Animals; Behavior, Animal; Diabetes Mellitus, Type 2; Dipeptidyl Peptidase 4; Dipeptidyl-Peptidase IV Inhibitors; Glucagon-Like Peptide 1; Hypoglycemic Agents; Linagliptin; Male; Morphine; Rats, Wistar; Reward | 2020 |
[Primary prevention of coronary heart disease : Evidence-based drug treatment].
Coronary artery disease (CAD) is the most frequent cause of morbidity and mortality worldwide. Lifestyle modifications and drug treatment of cardiovascular risk factors are able to effectively prevent CAD. The basis of prevention is the assessment of the individual cardiovascular risk, e.g. by using a validated risk score. Documented evidence for prevention of CAD is available for the control of hypertension using angiotensin-converting enzyme (ACE) inhibitors, angiotensin receptor blockers (ARB) and calcium antagonists, for the treatment of hypercholesterolemia using statins, ezetimibe and proprotein convertase subtilisin-kexin type 9 (PCSK-9) inhibitors and for the treatment of type 2 diabetes mellitus with metformin, sodium-glucose transporter 2 (SGLT-2) inhibitors and glucagon-like peptide 1 (GLP-1) agonists. There is no positive benefit-risk ratio for people with a low risk in the use of acetylsalicylic acid in primary prevention, in contrast to the positive recommendations for secondary prevention. There is no evidence for the efficacy of primary prevention with beta blockers, dipeptidyl peptidase 4 (DPP-4) inhibitors, glitazones, sulfonylureas or insulin. Similarly, there is no evidence for drug treatment of obesity, any supplementation with vitamins or hormone preparations or omega‑3 fatty acids. Topics: Coronary Artery Disease; Diabetes Mellitus, Type 2; Glucagon-Like Peptide 1; Humans; Hypoglycemic Agents; Primary Prevention | 2020 |
Glucagon-like peptide-1 receptors in the kidney: impact on renal autoregulation.
Glucagon-like peptide-1 (GLP-1) and strategies based on this blood sugar-reducing and appetite-suppressing hormone are used to treat obesity and type 2 diabetes. However, the GLP-1 receptor (GLP-1R) is also present in the kidney, where it influences renal function. The effect of GLP-1 on the kidney varies between humans and rodents. The effect of GLP-1 on kidney function also seems to vary depending on its concentration and the physiological or pathological state of the kidney. In studies with rodents or humans, acute infusion of pharmacological doses of GLP-1 stimulates natriuresis and diuresis. However, the effect on the renal vasculature is less clear. In rodents, GLP-1 infusion increases renal plasma flow and glomerular filtration rate, suggesting renal vasodilation. In humans, only a subset of the study participants exhibits increased renal plasma flow and glomerular filtration rate. Differential status of kidney function and changes in renal vascular resistance of the preglomerular arterioles may account for the different responses of the human study participants. Because renal function in patients with type 2 diabetes is already at risk or compromised, understanding the effects of GLP-1R activation on kidney function in these patients is particularly important. This review examines the distribution of GLP-1R in the kidney and the effects elicited by GLP-1 or GLP-1R agonists. By integrating results from acute and chronic studies in healthy individuals and patients with type 2 diabetes along with those from rodent studies, we provide insight into how GLP-1R activation affects renal function and autoregulation. Topics: Animals; Diabetes Mellitus, Type 2; Diabetic Nephropathies; Glomerular Filtration Rate; Glucagon-Like Peptide 1; Glucagon-Like Peptide-1 Receptor; Homeostasis; Humans; Incretins; Kidney; Ligands; Natriuresis; Renal Circulation; Signal Transduction | 2020 |
The relationship between plasma GIP and GLP-1 levels in individuals with normal and impaired glucose tolerance.
Glucose-dependent insulinotropic polypeptide (GIP) is released primarily from the proximal small intestine and glucagon-like peptide-1 (GLP-1) from the more distal small intestine and colon. Their relative importance to the incretin effect in health has been contentious in the past, although it now appears that GIP has the dominant role. It is uncertain whether there is a relationship between GIP and GLP-1 secretion. We aimed to evaluate the relationship between plasma GIP and GLP-1 responses to a 75-g oral glucose load in individuals with normal (NGT) and impaired glucose tolerance (IGT).. One hundred healthy subjects had measurements of blood glucose, serum insulin, plasma GIP and GLP-1 concentrations for 240 min after a 300 mL drink containing 75 g glucose.. Fifty had NGT and 41 IGT; 9 had type 2 diabetes and were excluded from analysis. In both groups, there were increases in plasma GIP and GLP-1 following the glucose drink, with no difference in the magnitude of the responses between t = 0-240 min. There was a weak relationship between the iAUC. There is a weak relationship between oral glucose-induced GIP and GLP-1 secretions in non-diabetic subjects. Topics: Aged; Blood Glucose; Case-Control Studies; Diabetes Mellitus, Type 2; Female; Gastric Inhibitory Polypeptide; Glucagon-Like Peptide 1; Glucose Intolerance; Glucose Tolerance Test; Humans; Insulin; Male | 2020 |
Myeloid-Derived Growth Factor Promotes Intestinal Glucagon-Like Peptide-1 Production in Male Mice With Type 2 Diabetes.
Myeloid-derived growth factor (MYDGF), which is produced by bone marrow-derived cells, mediates cardiac repair following myocardial infarction by inhibiting cardiac myocyte apoptosis to subsequently reduce the infarct size. However, the function of MYDGF in the incretin system of diabetes is still unknown. Here, loss-of-function and gain-of-function experiments in mice revealed that MYDGF maintains glucose homeostasis by inducing glucagon-like peptide-1 (GLP-1) production and secretion and that it improves glucose tolerance and lipid metabolism. Treatment with recombinant MYDGF increased the secretion and production of GLP-1 in STC-1 cells in vitro. Mechanistically, the positive effects of MYDGF are potentially attributable to the activation of protein kinase A/glycogen synthase kinase 3β/β-catenin (PKA/GSK-3β/β-catenin) and mitogen-activated protein kinase (MAPK) kinases/extracellular regulated protein kinase (MEK/ERK) pathways. Based on these findings, MYDGF promotes the secretion and production of GLP-1 in intestinal L-cells and potentially represents a potential therapeutic medication target for type 2 diabetes. Topics: Adult; Aged; Animals; Case-Control Studies; Cell Line; Diabetes Mellitus, Experimental; Diabetes Mellitus, Type 2; Glucagon-Like Peptide 1; Humans; Incretins; Interleukins; Male; MAP Kinase Signaling System; Mice, Knockout; Middle Aged | 2020 |
[Which injectable therapy after failure of oral antidiabetic agents in type 2 diabetes ?]
The shift to injection therapy, after failure of oral antidiabetic agents, is often considered as a difficult step by both the patient with type 2 diabetes and the physician, a situation that may lead to clinical inertia. Schematically, two options may be considered, either starting insulin therapy with a preference for basal insulin analogues, or adding a glucagon-like peptide-1 receptor agonist (GLP-1 RA). Each option has its advantages and disadvantages, which opens the road to personalized medicine. Nevertheless, the preference is increasingly given to GLP-1 AR, yet this solution is more limited by reimbursement conditions. A combination of the two approaches is also possible, with the recent commercialisation of fixed-ratio specialities combining a basal insulin analogue and a GLP-1 RA. This clinical case offers the opportunity to discuss all these different therapeutic options in a patient with poorly controlled type 2 diabetes despite a combination of oral antidiabetic agents, taking also into account the current conditions for reimbursement in Belgium.. Le passage à un traitement injectable, après échec des antidiabétiques oraux, est souvent considéré comme une étape délicate, pour le patient diabétique de type 2 comme pour le médecin, ce qui peut conduire à une certaine inertie thérapeutique. Schématiquement, deux options peuvent être envisagées, soit débuter une insulinothérapie en préférant un analogue d’insuline à action basale, soit recourir à un agoniste des récepteurs du glucagon-like peptide-1 (AR GLP-1). Chaque option a ses avantages et ses inconvénients, ce qui ouvre la voie à une médecine personnalisée. Néanmoins, la préférence est de plus en plus donnée aux AR GLP-1, mais cette solution est davantage soumise à des conditions restrictives de remboursement. Une combinaison des deux options est également possible, avec la commercialisation récente de deux spécialités à ratio fixe d’un analogue d’insuline basale et d’un AR GLP-1. Cette vignette clinique discute ces différentes options thérapeutiques chez un patient diabétique de type 2 insuffisamment contrôlé sous antidiabétiques oraux, tout en tenant compte des conditions de remboursement actuellement en vigueur en Belgique. Topics: Administration, Oral; Diabetes Mellitus, Type 2; Glucagon-Like Peptide 1; Glucagon-Like Peptide-1 Receptor; Humans; Hypoglycemic Agents; Insulin | 2020 |
Assessing the Risk for Gout With Sodium-Glucose Cotransporter-2 Inhibitors in Patients With Type 2 Diabetes: A Population-Based Cohort Study.
Hyperuricemia is common in patients with type 2 diabetes mellitus and is known to cause gout. Sodium-glucose cotransporter-2 (SGLT2) inhibitors prevent glucose reabsorption and lower serum uric acid levels.. To compare the rate of gout between adults prescribed an SGLT2 inhibitor and those prescribed a glucagon-like peptide-1 (GLP1) receptor agonist.. Population-based new-user cohort study.. A U.S. nationwide commercial insurance database from March 2013 to December 2017.. Persons with type 2 diabetes newly prescribed an SGLT2 inhibitor were 1:1 propensity score matched to patients newly prescribed a GLP1 agonist. Persons were excluded if they had a history of gout or had received gout-specific treatment previously.. The primary outcome was a new diagnosis of gout. Cox proportional hazards regression was used to estimate hazard ratios (HRs) of the primary outcome and 95% CIs.. The study identified 295 907 adults with type 2 diabetes mellitus who were newly prescribed an SGLT2 inhibitor or a GLP1 agonist. The gout incidence rate was lower among patients prescribed an SGLT2 inhibitor (4.9 events per 1000 person-years) than those prescribed a GLP1 agonist (7.8 events per 1000 person-years), with an HR of 0.64 (95% CI, 0.57 to 0.72) and a rate difference of -2.9 (CI, -3.6 to -2.1) per 1000 person-years.. Unmeasured confounding, missing data (namely incomplete laboratory data), and low baseline risk for gout.. Adults with type 2 diabetes prescribed an SGLT2 inhibitor had a lower rate of gout than those prescribed a GLP1 agonist. Sodium-glucose cotransporter-2 inhibitors may reduce the risk for gout among adults with type 2 diabetes mellitus, although future studies are necessary to confirm this observation.. Brigham and Women's Hospital. Topics: Cohort Studies; Diabetes Mellitus, Type 2; Female; Glucagon-Like Peptide 1; Gout; Humans; Hypoglycemic Agents; Male; Matched-Pair Analysis; Middle Aged; Sodium-Glucose Transporter 2 Inhibitors; United States | 2020 |
Glucagon-Like Peptide Analogs Are Superior for Diabetes and Weight Control in Patients on Antipsychotic Medications: A Retrospective Cohort Study.
Glucagon-like peptide (GLP-1) analogs promote diabetes control and weight loss. Most GLP-1 analogs also lower adverse cardiovascular outcomes, making them ideal agents for patients with severe mental illness. The objective of this study was to analyze diabetic patients taking antipsychotic medications, comparing those on GLP-1 analogs with those on other diabetes treatments.. A total of 46 patients referred to outpatient diabetes clinics between July 2010 and April 2017 who were prescribed antipsychotic medications during the entire study period were included in this retrospective analysis. Eleven (24%) patients were started on a GLP-1 analog (cases), and 35 (76%) were treated with alternative antidiabetic agents (controls).. Cases and controls did not differ in age, sex, height, weight, or medical therapies at the time of referral. Within 1 year, a reduction in mean ± SE glycosylated hemoglobin (HbA1c) levels was noted for both groups (cases: -1.26% ± 0.17%, controls: -1.47% ± 0.45%). However, while patients on GLP-1 analogs lost 7.07 ± 2.62 kg, control patients gained 1.93 ± 1.14 kg (P < .05). Blunted HbA1c reductions were also noted in patients who took antipsychotic medication in addition to antidepressant medication (on antidepressant medication [n = 22]: -0.77% ± 0.29%, off antidepressant medication [n = 9]: -2.97% ± 0.6%, P < .001). This observation did not apply to patients treated with GLP-1 analogs, as they had larger HbA1c reductions than patients on alternative regimens (controls [n = 15]: -0.46% ± 0.4%, cases [n = 7]: -1.43% ± 0.15%, P < .05).. GLP-1 analogs promote both diabetes and weight control in diabetic patients on antipsychotic medications with or without antidepressant medications. Topics: Adult; Aged; Antipsychotic Agents; Body Weight; Case-Control Studies; Comorbidity; Diabetes Mellitus, Type 2; Female; Glucagon-Like Peptide 1; Glycated Hemoglobin; Humans; Hypoglycemic Agents; Male; Mental Disorders; Middle Aged; Retrospective Studies; Treatment Outcome | 2020 |
Composite probiotics alleviate type 2 diabetes by regulating intestinal microbiota and inducing GLP-1 secretion in db/db mice.
Previous studies have found that probiotic fermented camel milk has anti-diabetic effect by inducing (glucagon-like peptide-1) GLP-1 secretion. Probiotics are valuable in prevention and treatment of diabetes. As a result, our team islolated 14 probiotics from fermented camel milk. These probiotics have beneficial characteristics, but the possible anti-diabetic mechanisms remains unclear. The present study aimed to explore the possoble anti-diabetic mechanisms of 14 probiotics.. C57BL/Ks mice were normal group. The db/db mice were randomized into five groups: model group, metformin group, liraglutide group, low-dose and high-dose probiotic group. Biochemical parameters were determined by the respective assay kits. The levels of the short-chain fatty acids (SCFAs) and microbiota were respectively determined by gas chromatography and qRT-PCR. HE staining and immunofluorescence were used for histomorphological observation. Quantitative PCR and western-blot were determined the gene and protein expression of Bax, Bcl-2, Caspase-3 and PI3K/AKT.. Probiotics significantly improved blood glucose and blood lipid parameters, as well as the morphological changes of pancreas, liver and kidney. Probiotics improved the gut barrier function through increasing the levels of SCFA-producing bacteria and SCFAs as well as the expression of claudin-1 and mucin-2, and decreasing Escherichia coli and LPS level. In additon, probiotics enhanced insulin secretion through glucose-triggered GLP-1 secretion by upregulating G protein-coupled receptor 43/41 (GPR43/41), proglucagon and proconvertase 1/3 activity. Forthermore, probiotics protected pancreas against apoptosis, which may be dependent on the upregulation of PI3K/AKT pathway.. The anti-diabetic effect of 14 probiotics in db/db mice seem to be related to an increase of SCFA-producing bacteria, the improvement of intestinal barrier function and the upregulation of GLP-1 production, and indicate these probiotics might be a good candidate to prevent and treat diabetes. Topics: Animals; Blood Glucose; Camelus; Cholesterol; Diabetes Mellitus, Experimental; Diabetes Mellitus, Type 2; Gastrointestinal Microbiome; Glucagon-Like Peptide 1; Male; Mice; Mice, Inbred C57BL; Probiotics | 2020 |
Glucagon receptor antagonist upregulates circulating GLP-1 level by promoting intestinal L-cell proliferation and GLP-1 production in type 2 diabetes.
Glucagon receptor (GCGR) blockage improves glycemic control and increases circulating glucagon-like peptide-1 (GLP-1) level in diabetic animals and humans. The elevated GLP-1 has been reported to be involved in the hypoglycemic effect of GCGR blockage. However, the source of this elevation remains to be clarified.. The elevated circulating GLP-1 level by GCGR mAb is mainly due to intestinal L-cell proliferation and GLP-1 production, which may be mediated via GLP-1R/PKA signaling pathways. Therefore, GCGR mAb represents a promising strategy to improve glycemic control and restore the impaired GLP-1 production in T2D. Topics: Animals; Antibodies, Monoclonal; Cell Proliferation; Diabetes Mellitus, Experimental; Diabetes Mellitus, Type 2; Glucagon-Like Peptide 1; Ileum; L Cells; Male; Mice; Mice, Inbred C57BL; Proglucagon; Receptors, Glucagon; Signal Transduction | 2020 |
Liraglutide Protects Against Brain Amyloid-β
Topics: Alzheimer Disease; Amyloid beta-Peptides; Animals; Behavior, Animal; Brain; Cyclic AMP-Dependent Protein Kinases; Diabetes Mellitus, Type 2; Estradiol; Female; Glucagon-Like Peptide 1; Glycolysis; Hypoglycemic Agents; Inflammation; Liraglutide; Maze Learning; Memory Disorders; Mice; Neurofibrillary Tangles; Nitrosative Stress; Oxidative Stress; Peptide Fragments; Phenotype; Plaque, Amyloid | 2020 |
Fructo-oligosaccharides alleviate inflammation-associated apoptosis of GLP-1 secreting L cells via inhibition of iNOS and cleaved caspase-3 expression.
Glucagon-like peptide 1 (GLP-1) released from enteroendocrine (L) cells regulates insulin secretion. Intestinal inflammation and impaired GLP-1 release have been found in type 2 diabetes mellitus (T2DM) patients. Fructo-oligosaccharides (FOS), a known prebiotic, improve GLP-1 release and glucose homeostasis in T2DM models. This study aimed to investigate the effect of tumor necrosis factor-α (TNF-α), a proinflammatory cytokine associated with intestinal inflammation in T2DM, on L cell apoptosis and the effect of FOS on inflammation-associated impairment of GLP-1 secretion. Herein, using cell death assays, immunofluorescence staining, real time PCR and Western blot analyses, we found that TNF-α induced L cell apoptosis via nuclear factor kappa B (NF-κB)- inducible nitric oxide synthase (iNOS)-cleaved caspase-3-dependent pathways. Interestingly, FOS did not suppress TNF-α-induced NF-κB nuclear translocation, but inhibited expression of iNOS and cleaved caspase-3. In addition, FOS alleviated apoptosis and rescued impaired GLP-1 release in TNF-α-treated L cells. Altogether, our data indicate that TNF-α induces L cell apoptosis via an NF-κB-iNOS-caspase-3-dependent pathway. FOS may be useful in suppressing inflammation-associated L cell apoptosis and maintaining GLP-1 level in T2DM patients. Topics: Apoptosis; Caspase 3; Diabetes Mellitus, Type 2; Enteroendocrine Cells; Glucagon-Like Peptide 1; Humans; Inflammation; NF-kappa B; Nitric Oxide Synthase Type II; Oligosaccharides; Signal Transduction; Tumor Necrosis Factor-alpha | 2020 |
Risk of Major Adverse Cardiovascular Events, Severe Hypoglycemia, and All-Cause Mortality for Widely Used Antihyperglycemic Dual and Triple Therapies for Type 2 Diabetes Management: A Cohort Study of All Danish Users.
The vast number of antihyperglycemic medications and growing amount of evidence make clinical decision making difficult. The aim of this study was to investigate the safety of antihyperglycemic dual and triple therapies for type 2 diabetes management with respect to major adverse cardiovascular events, severe hypoglycemia, and all-cause mortality in a real-life clinical setting.. Cox regression models were constructed to analyze 20 years of data from the Danish National Patient Registry with respect to effect of the antihyperglycemic therapies on the three end points.. A total of 66,807 people with type 2 diabetes were treated with metformin (MET) plus a combination of second- and third-line therapies. People on MET plus sulfonylurea (SU) had the highest risk of all end points, except for severe hypoglycemia, for which people on MET plus basal insulin (BASAL) had a higher risk. The lowest risk of major adverse cardiovascular events was seen for people on a regimen including a glucagon-like peptide 1 (GLP-1) receptor agonist. People treated with MET, GLP-1, and BASAL had a lower risk of all three end points than people treated with MET and BASAL, especially for severe hypoglycemia. The lowest risk of all three end points was, in general, seen for people treated with MET, sodium-glucose cotransporter 2 inhibitor, and GLP-1.. Findings from this study do not support SU as the second-line treatment choice for patients with type 2 diabetes. Moreover, the results indicate that adding a GLP-1 in people treated with MET and BASAL could be considered, especially if those people suffer from severe hypoglycemia. Topics: Aged; Cardiovascular Diseases; Cause of Death; Cohort Studies; Denmark; Diabetes Mellitus, Type 2; Drug Therapy, Combination; Drug-Related Side Effects and Adverse Reactions; Female; Glucagon-Like Peptide 1; Humans; Hypoglycemia; Hypoglycemic Agents; Male; Metformin; Middle Aged; Registries; Risk Factors; Severity of Illness Index; Sulfonylurea Compounds; Treatment Outcome | 2020 |
Ferritin-Displayed GLP-1 with Improved Pharmacological Activities and Pharmacokinetics.
Glucagon-like peptide-1 (GLP-1) is an incretin (a type of metabolic hormone that stimulates a decrease in blood glucose levels), holding great potential for the treatment of type 2 diabetes mellitus (T2DM). However, its extremely short half-life of 1-2 min hampers any direct clinical application. Here, we describe the application of the heavy chain of human ferritin (HFt) nanocage as a carrier to improve the pharmacological properties of GLP-1. The GLP-HFt was designed by genetic fusion of GLP-1 to the N-terminus of HFt and was expressed in inclusion bodies in Topics: Animals; Blood Glucose; Diabetes Mellitus, Type 2; Escherichia coli; Ferritins; Glucagon-Like Peptide 1; Hypoglycemic Agents; Insulin; Mice | 2020 |
The GLP-1 analog exendin-4 modulates HSP72 expression and ERK1/2 activity in BTC6 mouse pancreatic cells.
Lipotoxicity, an important factor in the pathogenesis of diabetes, leads to defective β-cell proliferation and increased apoptosis. Glucagon-like peptide-1 (GLP-1) analogs, which are used to treat type 2 diabetes, reduce endoplasmic reticulum stress and inflammation in pancreatic β-cells and improve their survival. However, their effects on the heat shock response (HSR) have not been elucidated yet. We investigated whether the GLP-1 analog exendin-4 exerts its protective effect by modulating the HSR and mitogen-activated protein kinases (MAPKs) in BTC-6 mouse pancreatic cells under palmitic acid (PA) stress. Expression patterns were analyzed using mass spectrometry, Western blotting, and qRT-PCR in the presence of 250 or 400 μM PA and 100 nM exendin-4. Additionally, we measured MAPK expression and phosphorylation using qRT-PCR and Western blotting, respectively. Upregulation of heat shock protein (HSP), notably HSP72, in the presence of PA, was attenuated by exendin-4. Despite the absence of global effects on the HSR system, exendin-4 attenuated the expression of other non-classical HSPs (GRP94, DNAJA1, and DNAJB6) in the presence of PA. Regarding MAPKs, only extracellular signal-regulated kinase (ERK) phosphorylation was highly increased by exendin-4 in both the presence and absence of PA. Furthermore, exendin-4 significantly alleviated PA-induced cell death, which was further confirmed with proteomics analysis where key cellular functions, including cellular growth, assembly, and organization, were improved by exendin-4 treatment. Thus, our results expand the protective role of GLP-1 analogs to include other cellular mechanisms involved in restoring normal β-cell homeostasis. Topics: Animals; Apoptosis; Cell Line; Cell Proliferation; Cell Survival; Diabetes Mellitus, Type 2; Endoplasmic Reticulum; Exenatide; Glucagon-Like Peptide 1; HSP40 Heat-Shock Proteins; HSP72 Heat-Shock Proteins; Insulin-Secreting Cells; MAP Kinase Signaling System; Membrane Glycoproteins; Mice; Molecular Chaperones; Phosphorylation; Protective Agents; Protein Interaction Maps; Up-Regulation | 2020 |
An orally available hypoglycaemic peptide taken up by caveolae transcytosis displays improved hypoglycaemic effects and body weight control in db/db mice.
Type 2 diabetes is one of the most severe chronic diseases and is an increasingly important public health problem worldwide. Several agonists of the glucagon-like peptide-1 (GLP-1) receptor have been developed to treat Type 2 diabetes but most of them are administered by injection. This mode of administration seriously reduces patient compliance and increases the risk of infection. Here, we describe the actions of a novel, orally available, GLP-1 receptor agonist - oral hypoglycaemic peptide 2 (OHP2) - derived from exendin-4 by replacing amino acids. We have also investigated its pharmacokinetic profiles, therapeutic effects and absorption mechanism.. Healthy Wistar rats were used for pharmacokinetic analyses. In diabetic db/db mice. OHP2 was given for 8 weeks to evaluate its effects on hyperglycaemia, dyslipidaemia, basal metabolism and tissue injury. Possible endocytosis and transcytosis mechanisms of OHP2 uptake were explored in Caco-2 cell monolayers.. In rats, the absolute bioavailability of orally administered OHP2 was 20-fold greater than that of orally administered exendin-4. In db/db mice, OHP2 dose-dependently exhibits good potential in glucose-lowering and weight loss after oral administration. OHP2 also alleviated hyperlipidaemia, ameliorated energy metabolism and promoted tissue repair in diabetic mice. Furthermore, uptake of OHP2 by Caco-2 cells was dependent on caveolae-mediated transcytosis rather than endocytosis mediated by GLP-1 receptors.. OHP2 is a potential, orally bioavailable, candidate drug for the treatment of Type 2 diabetes. Its transcytosis mechanism of uptake could help in the development of absorption enhancers of OHP2. Topics: Animals; Blood Glucose; Body Weight; Caco-2 Cells; Caveolae; Diabetes Mellitus, Experimental; Diabetes Mellitus, Type 2; Glucagon-Like Peptide 1; Glucagon-Like Peptide-1 Receptor; Humans; Hypoglycemic Agents; Insulin; Mice; Mice, Inbred Strains; Peptides; Rats; Rats, Wistar; Transcytosis | 2020 |
Glucagon from the phylogenetically ancient paddlefish provides a template for the design of a long-acting peptide with effective anti-diabetic and anti-obesity activities.
This study has examined the in vitro and in vivo anti-diabetic properties of the peptidase-resistant analogues [D-Ser Topics: Amino Acid Sequence; Animals; Anti-Obesity Agents; Apoptosis; Blood Glucose; Body Weight; Cell Proliferation; Cytokines; Diabetes Mellitus, Experimental; Diabetes Mellitus, Type 2; Gene Expression Regulation; Glucagon; Glucagon-Like Peptide 1; Glucagon-Like Peptide-1 Receptor; Glucose Transporter Type 2; Humans; Hypoglycemic Agents; Insulin; Insulin Resistance; Insulin-Secreting Cells; Islets of Langerhans; Male; Mice; Neoplasm Proteins; Obesity; Receptors, Glucagon; Structure-Activity Relationship | 2020 |
Rational design and biological evaluation of gemfibrozil modified Xenopus GLP-1 derivatives as long-acting hypoglycemic agents.
Novel methods for peptides structural modification and bioactivity optimization are highly needed in peptide-based drug discovery. Herein, we explored the use gemfibrozil (GFZ) as an albumin binder to enhance the stability and improve the bioactivity of peptides. Short-acting Xenopus glucagon-like peptide-1 (xGLP-1) analogues with anti-diabetic activity were selected as the starting point. Mono-GFZ conjugation, peptide sequence hybridization, and dimeric-GFZ derivatization were successively used to generate novel GFZ-xGLP-1 conjugates, biologically screened by various in vitro and in vivo models. Dimeric-GFZ modified conjugate 3b was finally identified as a promising anti-diabetic candidate with high albumin binding affinity, enhanced in vivo stability in SD rats, and long-acting hypoglycemic activity in db/db mice. Moreover, GFZ endowed 3b with strong lipid-regulating ability in DIO and db/db mice. In a twelve-week study, chronic administration of 3b in db/db mice resulted in sustained glycemic control, to a greater extent than liraglutide and semaglutide. In addition, 3b showed comparable therapeutic efficacies to liraglutide and semaglutide on HbA1c and pancreas islets protection. Our studies reveal 3b as a potential candidate for the treatment of metabolic diseases and indicate dimeric-GFZ modification as a novel method for peptide optimization. Topics: Albumins; Animals; Blood Glucose; Diabetes Mellitus, Experimental; Diabetes Mellitus, Type 2; Dose-Response Relationship, Drug; Drug Development; Gemfibrozil; Glucagon-Like Peptide 1; Glucagon-Like Peptides; Glucose Tolerance Test; HEK293 Cells; Humans; Hypoglycemic Agents; Liraglutide; Male; Mice; Mice, Inbred C57BL; Mice, Inbred ICR; Rats, Sprague-Dawley; Xenopus laevis | 2020 |
Receptor-Mediated Bioassay Reflects Dynamic Change of Glucose-Dependent Insulinotropic Polypeptide by Dipeptidyl Peptidase 4 Inhibitor Treatment in Subjects With Type 2 Diabetes.
Topics: Aged; Biological Assay; Biomarkers; Blood Glucose; Case-Control Studies; Diabetes Mellitus, Type 2; Dipeptidyl-Peptidase IV Inhibitors; Female; Follow-Up Studies; Gastric Inhibitory Polypeptide; Glucagon; Glucagon-Like Peptide 1; Glucose Tolerance Test; Glycated Hemoglobin; Humans; Male; Prognosis; Receptors, Gastrointestinal Hormone | 2020 |
Human islets contain a subpopulation of glucagon-like peptide-1 secreting α cells that is increased in type 2 diabetes.
Our study shows that glucagon-like peptide-1 (GLP-1) is secreted within human islets and may play an unexpectedly important paracrine role in islet physiology and pathophysiology. It is known that α cells within rodent and human pancreatic islets are capable of secreting GLP-1, but little is known about the functional role that islet-derived GLP-1 plays in human islets.. We used flow cytometry, immunohistochemistry, perifusions, and calcium imaging techniques to analyse GLP-1 expression and function in islets isolated from cadaveric human donors with or without type 2 diabetes. We also used immunohistochemistry to analyse GLP-1 expression within islets from pancreatic biopsies obtained from living donors.. We have demonstrated that human islets secrete ∼50-fold more GLP-1 than murine islets and that ∼40% of the total human α cells contain GLP-1. Our results also confirm that dipeptidyl peptidase-4 (DPP4) is expressed in α cells. Sitagliptin increased GLP-1 secretion from cultured human islets but did not enhance glucose-stimulated insulin secretion (GSIS) in islets from non-diabetic (ND) or type 2 diabetic (T2D) donors, suggesting that β cell GLP-1 receptors (GLP-1R) may already be maximally activated. Therefore, we tested the effects of exendin-9, a GLP-1R antagonist. Exendin-9 was shown to reduce GSIS by 39% and 61% in ND islets and T2D islets, respectively. We also observed significantly more GLP-1+ α cells in T2D islets compared with ND islets obtained from cadaveric donors. Furthermore, GLP-1+ α cells were also identified in pancreatic islet sections obtained from living donors undergoing surgery.. In summary, we demonstrated that human islets secrete robust amounts of GLP-1 from an α cell subpopulation and that GLP-1R signalling may support GSIS to a greater extent in T2D islets. Topics: Animals; Biomarkers; Diabetes Mellitus, Type 2; Gene Expression; Glucagon; Glucagon-Like Peptide 1; Glucagon-Secreting Cells; Glucose; Humans; Immunophenotyping; Insulin; Insulin-Secreting Cells; Islets of Langerhans; Mice | 2020 |
Cardioprotective effects of GLP-1(28-36a): A degraded metabolite or GLP-1's better half?
Molecular mechanism underlying glucagon-like peptide-1 exertion of cardioprotective effects in glucagon-like peptide-1 receptor-dependent and -independent manners. Glucagon-like peptide-1 (28-36a) enters coronary artery endothelial cells through macropinocytosis and binds to mitochondrial trifunctional protein-α, shifting substrate utilization to increase adenosine triphosphate production and modulating a adenosine triphosphate-sensor soluble adenylyl cyclase, thereby producing cyclic adenosine monophosphate and activating protein kinase A to exert cytoprotection from oxidative injury. Topics: Adenosine Triphosphate; Cardiotonic Agents; Cardiovascular Diseases; Diabetes Mellitus, Type 2; Glucagon-Like Peptide 1; Glucagon-Like Peptide-1 Receptor; Humans; Hypoglycemic Agents; Peptide Fragments; Prognosis; Signal Transduction | 2020 |
Everestmab, a novel long-acting GLP-1/anti GLP-1R nanobody fusion protein, exerts potent anti-diabetic effects.
In the present study, a novel single domain antibody (sdAb) fusion protein, named everestmab, composing of a mutated GLP-1(A8G) fused to the tandem bispecific humanized GLP-1R-targeting and albumin-binding nanobodies was designed and characterized for the therapies for type 2 diabetes mellitus (T2DM). Surface plasmon resonance (SPR) measurements demonstrated everestmab associates with serum albumins of rat and monkey species with high affinity, and tends to be cross-reactive with rat and monkey species. Topics: Animals; Diabetes Mellitus, Type 2; Glucagon-Like Peptide 1; Glucagon-Like Peptide-1 Receptor; Hypoglycemic Agents; Macaca fascicularis; Male; Rats; Rats, Sprague-Dawley; Recombinant Fusion Proteins; Single-Domain Antibodies; Tissue Distribution | 2020 |
Zwitterionic Polymer Conjugated Glucagon-like Peptide-1 for Prolonged Glycemic Control.
Glucagon-like peptide-1 (GLP-1) is of particular interest for treating type 2 diabetes mellitus (T2DM), as it induces insulin secretion in a glucose-dependent fashion and has the potential to facilitate weight control. However, native GLP-1 is a short incretin peptide that is susceptible to fast proteolytic inactivation and rapid clearance from the circulation. Various GLP-1 analogs and bioconjugation of GLP-1 analogs have been developed to counter these issues, but these modifications are frequently accompanied by the sacrifice of potency and the induction of immunogenicity. Here, we demonstrated that with the conjugation of a zwitterionic polymer, poly(carboxybetaine) (pCB), the pharmacokinetic properties of native GLP-1 were greatly enhanced without serious negative effects on its potency and secondary structure. The pCB conjugated GLP-1 further provided glycemic control for up to 6 days in a mouse study. These results illustrate that the conjugation of pCB could realize the potential of using native GLP-1 for prolonged glycemic control in treating T2DM. Topics: Animals; Diabetes Mellitus, Type 2; Disease Models, Animal; Glucagon-Like Peptide 1; Glycemic Control; Half-Life; Hypoglycemic Agents; Mice; Polymers; Protein Structure, Secondary | 2020 |
The novel dual glucose-dependent insulinotropic polypeptide and glucagon-like peptide-1 (GLP-1) receptor agonist tirzepatide transiently delays gastric emptying similarly to selective long-acting GLP-1 receptor agonists.
The effect of dual glucose-dependent insulinotropic polypeptide (GIP) and glucagon-like peptide-1 (GLP-1) receptor agonist (RA) tirzepatide on gastric emptying (GE) was compared to that of GLP-1RAs in non-clinical and clinical studies. GE was assessed following acute and chronic treatment with tirzepatide in diet-induced obese mice versus semaglutide or long-acting GIP analogue alone. Participants [with and without type 2 diabetes (T2DM)] from a phase 1, 4-week multiple dose study received tirzepatide, dulaglutide or placebo. GE was assessed by acetaminophen absorption. In mice, tirzepatide delayed GE to a similar degree to that achieved with semaglutide; however, these acute inhibitory effects were abolished after 2 weeks of treatment. GIP analogue alone had no effect on GE or on GLP-1's effect on GE. In participants with and without T2DM, once-weekly tirzepatide (≥5 and ≥4.5 mg, respectively) delayed GE after a single dose. This effect diminished after multiple doses of tirzepatide or dulaglutide in healthy participants. In participants with T2DM treated with an escalation schedule of tirzepatide 5/5/10/10 or 5/5/10/15 mg, a residual GE delay was still observed after multiple doses. These data suggest that tirzepatide's activity on GE is comparable to that of selective GLP-1RAs. Topics: Animals; Blood Glucose; Diabetes Mellitus, Type 2; Gastric Emptying; Gastric Inhibitory Polypeptide; Glucagon-Like Peptide 1; Glucagon-Like Peptide-1 Receptor; Glucose; Mice | 2020 |
Renal outcomes of SGLT2 inhibitors and GLP1 agonists in clinical practice.
Topics: Cohort Studies; Diabetes Mellitus, Type 2; Glucagon-Like Peptide 1; Humans; Hypoglycemic Agents; Sodium-Glucose Transporter 2 Inhibitors | 2020 |
A Physiologically-Based Quantitative Systems Pharmacology Model of the Incretin Hormones GLP-1 and GIP and the DPP4 Inhibitor Sitagliptin.
Incretin hormones glucagon-like peptide-1 (GLP-1) and glucose-dependent insulinotropic polypeptide (GIP) play a major role in regulation of postprandial glucose and the development of type 2 diabetes mellitus. The incretins are rapidly metabolized, primarily by the enzyme dipeptidyl-peptidase 4 (DPP4), and the neutral endopeptidase (NEP), although the exact metabolization pathways are unknown. We developed a physiologically-based (PB) quantitative systems pharmacology model of GLP-1 and GIP and their metabolites that describes the secretion of the incretins in response to intraduodenal glucose infusions and their degradation by DPP4 and NEP. The model describes the observed data and suggests that NEP significantly contributes to the metabolization of GLP-1, and the traditional assays for the total GLP-1 and GIP forms measure yet unknown entities produced by NEP. We further extended the model with a PB pharmacokinetics/pharmacodynamics model of the DPP4 inhibitor sitagliptin that allows predictions of the effects of this medication class on incretin concentrations. Topics: Computer Simulation; Diabetes Mellitus, Type 2; Dipeptidyl Peptidase 4; Dipeptidyl-Peptidase IV Inhibitors; Gastric Inhibitory Polypeptide; Glucagon-Like Peptide 1; Humans; Models, Biological; Neprilysin; Numerical Analysis, Computer-Assisted; Sitagliptin Phosphate; Treatment Outcome | 2020 |
Optimized Methods for the Production and Bioconjugation of Site-Specific, Alkyne-Modified Glucagon-like Peptide-1 (GLP-1) Analogs to Azide-Modified Delivery Platforms Using Copper-Catalyzed Alkyne-Azide Cycloaddition.
Topics: Alkynes; Amino Acid Sequence; Azides; Blood Glucose; Copper; Cycloaddition Reaction; Diabetes Mellitus, Type 2; Drug Delivery Systems; Drug Stability; Glucagon-Like Peptide 1; Humans | 2020 |
Cyclocarya paliurus polysaccharides alleviate type 2 diabetic symptoms by modulating gut microbiota and short-chain fatty acids.
Cyclocarya paliurus polysaccharide (CCPP), a primary active component in the leaves of Cyclocarya paliurus (Batal.) Iljinsk (C. paliurus), has the ability to treat type 2 diabetes mellitus (T2DM), but cannot be digested by our digestive system. Therefore, mechanisms of regulating the gut microbiota and intestinal metabolites might exist.. To reveal the potential mechanism of CCPP treatment, this study aimed to investigate the alterations of the gut microbiota and intestinal metabolites especially short chain fatty acids (SCFAs) in type 2 diabetic rats.. Type 2 diabetic rat models were developed, and the therapeutic effects of CCPP were evaluated. Metagenomics analysis was utilized to analyze the alterations to the gut microbiota, and UHPLC-QTOF/MS-based untargeted metabolomics analysis of colon contents was used to identify the differential intestinal metabolites. GC/MS was used to measure the SCFAs in rat's colon contents and human fecal inoculums. Furthermore, the expression of SCFA receptors including GPR41, GPR43 and GPR109a was verified by qRT-PCR and the concentration of glucagon-like peptide-1(GLP-1) and peptide tyrosinetyrosine (PYY) was measured by Elisa.. Inhibition of the blood glucose levels and improvements in glucose tolerance and serum lipid parameters were observed after CCPP treatment. Eleven SCFA-producing species including Ruminococcus_bromii, Anaerotruncus_colihominis, Clostridium_methylpentosum, Roseburia_intestinalis, Roseburia_hominis, Clostridium_asparagiforme, Pseudoflavonifractor_capillosus, Intestinimonas_butyriciproducens, Intestinimonas_sp._GD2, Oscillibacter_valericigenes and Oscillibacter_ruminantium were clearly increased in the CCPP group. Furthermore, our study indicated that CCPP increases the production of SCFAs both in vivo and in vitro, and the gut microbiota are the key factor of this process. The SCFA receptors including GPR41, GPR43 and GPR109a, were significantly stimulated in the CCPP treated rats, which was accompanied by the upregulated expression of GLP-1 and PYY.. These results demonstrated that CCPP could alleviate type 2 diabetic symptoms by increasing the SCFA-producing bacteria, promoting the production of SCFAs and upregulating SCFA-GLP1/PYY associated sensory mediators. Topics: Adult; Animals; Diabetes Mellitus, Experimental; Diabetes Mellitus, Type 2; Fatty Acids, Volatile; Feces; Female; Gastrointestinal Microbiome; Glucagon-Like Peptide 1; Humans; Hypoglycemic Agents; Juglandaceae; Male; Metabolomics; Metagenome; Plant Leaves; Plants, Medicinal; Polysaccharides; Rats, Sprague-Dawley | 2020 |
A Protein/Lipid Preload Attenuates Glucose-Induced Endothelial Dysfunction in Individuals with Abnormal Glucose Tolerance.
Postprandial hyperglycemia interferes with vascular reactivity and is a strong predictor of cardiovascular disease. Macronutrient preloads reduce postprandial hyperglycemia in subjects with impaired glucose tolerance (IGT) or type 2 diabetes (T2D), but the effect on endothelial function is unknown. Therefore, we examined whether a protein/lipid preload can attenuate postprandial endothelial dysfunction by lowering plasma glucose responses in subjects with IGT/T2D. Endothelial function was assessed by the reactive hyperemia index (RHI) at fasting, 60 min and 120 min during two 75 g oral glucose tolerance tests (OGTTs) preceded by either water or a macronutrient preload (i.e., egg and parmesan cheese) in 22 volunteers with IGT/T2D. Plasma glucose, insulin, glucagon-like peptide-1 (GLP-1), glucose-dependent insulinotropic polypeptide (GIP), glucagon, free fatty acids, and amino acids were measured through each test. RHI negatively correlated with fasting plasma glucose. During the control OGTT, RHI decreased by 9% and its deterioration was associated with the rise in plasma glucose. The macronutrient preload attenuated the decline in RHI and markedly reduced postprandial glycemia. The beneficial effect of the macronutrient preload on RHI was proportional to the improvement in glucose tolerance and was associated with the increase in plasma GLP-1 and arginine levels. In conclusion, a protein/lipid macronutrient preload attenuates glucose-induced endothelial dysfunction in individuals with IGT/T2D by lowering plasma glucose excursions and by increasing GLP-1 and arginine levels, which are known regulators of the nitric oxide vasodilator system. Topics: Adult; Blood Glucose; Diabetes Mellitus, Type 2; Dietary Fats; Dietary Proteins; Endothelium, Vascular; Fasting; Female; Gastric Inhibitory Polypeptide; Glucagon; Glucagon-Like Peptide 1; Glucose Intolerance; Glucose Tolerance Test; Humans; Hyperglycemia; Insulin; Male; Middle Aged; Postprandial Period; Young Adult | 2020 |
Dapagliflozin promotes beta cell regeneration by inducing pancreatic endocrine cell phenotype conversion in type 2 diabetic mice.
Clinical trials and animal studies have shown that sodium-glucose co-transporter type 2 (SGLT2) inhibitors improve pancreatic beta cell function. Our study aimed to investigate the effect of dapagliflozin on islet morphology and cell phenotype, and explore the origin and possible reason of the regenerated beta cells.. Two diabetic mouse models, db/db mice and pancreatic alpha cell lineage-tracing (glucagon-β-gal) mice whose diabetes was induced by high fat diet combined with streptozotocin, were used. Mice were treated by daily intragastric administration of dapagliflozin (1 mg/kg) or vehicle for 6 weeks. The plasma insulin, glucagon and glucagon-like peptide-1 (GLP-1) were determined by using ELISA. The evaluation of islet morphology and cell phenotype was performed with immunofluorescence. Primary rodent islets and αTC1.9, a mouse alpha cell line, were incubated with dapagliflozin (0.25-25 μmol/L) or vehicle in the presence or absence of GLP-1 receptor antagonist for 24 h in regular or high glucose medium. The expression of specific markers and hormone levels were determined.. Treatment with dapagliflozin significantly decreased blood glucose in the two diabetic models and upregulated plasma insulin and GLP-1 levels in db/db mice. The dapagliflozin treatment increased islet and beta cell numbers in the two diabetic mice. The beta cell proliferation as indicated by C-peptide and BrdU double-positive cells was boosted by dapagliflozin. The alpha to beta cell conversion, as evaluated by glucagon and insulin double-positive cells and confirmed by using alpha cell lineage-tracing, was facilitated by dapagliflozin. After the dapagliflozin treatment, some insulin-positive cells were located in the duct compartment or even co-localized with duct cell markers, suggestive of duct-derived beta cell neogenesis. In cultured primary rodent islets and αTC1.9 cells, dapagliflozin upregulated the expression of pancreatic endocrine progenitor and beta cell specific markers (including Pdx1) under high glucose condition. Moreover, dapagliflozin upregulated the expression of Pcsk1 (which encodes prohormone convertase 1/3, an important enzyme for processing proglucagon to GLP-1), and increased GLP-1 content and secretion in αTC1.9 cells. Importantly, the dapagliflozin-induced upregulation of Pdx1 expression was attenuated by GLP-1 receptor antagonist.. Except for glucose-lowering effect, dapagliflozin has extra protective effects on beta cells in type 2 diabetes. Dapagliflozin enhances beta cell self-replication, induces alpha to beta cell conversion, and promotes duct-derived beta cell neogenesis. The promoting effects of dapagliflozin on beta cell regeneration may be partially mediated via GLP-1 secreted from alpha cells. Topics: Animals; Benzhydryl Compounds; Blood Glucose; C-Peptide; Diabetes Mellitus, Experimental; Diabetes Mellitus, Type 2; Disease Models, Animal; Endocrine Cells; Glucagon; Glucagon-Like Peptide 1; Glucagon-Like Peptide-1 Receptor; Glucagon-Secreting Cells; Glucose; Glucosides; Insulin; Insulin-Secreting Cells; Male; Mice; Proprotein Convertase 1; Regeneration; Sodium-Glucose Transporter 2 Inhibitors | 2020 |
(E
Obesity has been recognized as a low-grade, chronic inflammatory disease that leads to an increase in obesity-associated disorders, including type 2 diabetes (T2D), fatty liver diseases and cancer. Glucagon-like peptide-1 (GLP-1) is an effective drug for T2D, and it not only has glucose-regulating effects but also has anti-inflammatory effects in obesity. In our previous study, we designed a novel GLP-1 analogue, (E Topics: Adipose Tissue; Animals; Anti-Inflammatory Agents; Cytokines; Diabetes Mellitus, Type 2; Diet, High-Fat; Glucagon-Like Peptide 1; Glucagon-Like Peptide-1 Receptor; Inflammation; Leptin; Macrophage Activation; Macrophages; Male; Mice, Inbred C57BL; Mice, Obese; NF-kappa B; Obesity; Signal Transduction | 2020 |
A surrogate of Roux-en-Y gastric bypass (the enterogastro anastomosis surgery) regulates multiple beta-cell pathways during resolution of diabetes in ob/ob mice.
Bariatric surgery is an effective treatment for type 2 diabetes. Early post-surgical enhancement of insulin secretion is key for diabetes remission. The full complement of mechanisms responsible for improved pancreatic beta cell functionality after bariatric surgery is still unclear. Our aim was to identify pathways, evident in the islet transcriptome, that characterize the adaptive response to bariatric surgery independently of body weight changes.. We performed entero-gastro-anastomosis (EGA) with pyloric ligature in leptin-deficient ob/ob mice as a surrogate of Roux-en-Y gastric bypass (RYGB) in humans. Multiple approaches such as determination of glucose tolerance, GLP-1 and insulin secretion, whole body insulin sensitivity, ex vivo glucose-stimulated insulin secretion (GSIS) and functional multicellular Ca. Taken together, our data highlight novel miRNA-gene interactions in the pancreatic islet during the resolution of diabetes after bariatric surgery that form part of a blood signature of diabetes reversal.. European Union's Horizon 2020 research and innovation programme via the Innovative Medicines Initiative 2 Joint Undertaking (RHAPSODY), INSERM, Société Francophone du Diabète, Institut Benjamin Delessert, Wellcome Trust Investigator Award (212625/Z/18/Z), MRC Programme grants (MR/R022259/1, MR/J0003042/1, MR/L020149/1), Diabetes UK (BDA/11/0004210, BDA/15/0005275, BDA 16/0005485) project grants, National Science Foundation (310030-188447), Fondation de l'Avenir. Topics: Animals; Diabetes Mellitus, Type 2; Disease Models, Animal; Gastric Bypass; Gene Expression Profiling; Gene Expression Regulation; Gene Regulatory Networks; Glucagon-Like Peptide 1; Glucose Tolerance Test; Humans; Insulin; Insulin-Secreting Cells; Male; Mice; Mice, Obese; MicroRNAs; Obesity | 2020 |
Risk of amputation with canagliflozin across categories of age and cardiovascular risk in three US nationwide databases: cohort study.
To estimate the rate of lower limb amputation among adults newly prescribed canagliflozin according to age and cardiovascular disease.. Population based, new user, cohort study.. Two commercial and Medicare claims databases, 2013-17.. Patients newly prescribed canagliflozin were propensity score matched 1:1 with patients newly prescribed a glucagon-like peptide-1 (GLP-1) receptor agonist. Hazard ratios and rate differences per 1000 person years were computed for the rate of lower limb amputation in the following four groups: group 1, patients aged less than 65 years without baseline cardiovascular disease; group 2, patients aged less than 65 with baseline cardiovascular disease; group 3, patients aged 65 or older without baseline cardiovascular disease; group 4, patients aged 65 or older with baseline cardiovascular disease. Within each group, pooled hazard ratio and rate difference per 1000 person years were calculated by meta-analysis.. Canagliflozin versus a GLP-1 agonist.. Lower limb amputation requiring surgery.. Across the three databases, 310 840 propensity score matched adults who started canagliflozin or a GLP-1 agonist were identified. The hazard ratio and rate difference per 1000 person years for amputation in adults receiving canagliflozin compared with a GLP-1 agonist for each group was: group 1, hazard ratio 1.09 (95% confidence interval 0.83 to 1.43), rate difference 0.12 (-0.31 to 0.55); group 2, hazard ratio 1.18 (0.86 to 1.62), rate difference 1.06 (-1.77 to 3.89); group 3, hazard ratio 1.30 (0.52 to 3.26), rate difference 0.47 (-0.73 to 1.67); and group 4, hazard ratio 1.73 (1.30 to 2.29), rate difference 3.66 (1.74 to 5.59).. The increase in rate of amputation with canagliflozin was small and most apparent on an absolute scale for adults aged 65 or older with baseline cardiovascular disease, resulting in a number needed to treat for an additional harmful outcome of 556 patients at six months (that is, 18 more amputations per 10 000 people who received canagliflozin). These results help to contextualize the risk of amputation with canagliflozin in routine care. Topics: Age Distribution; Aged; Amputation, Surgical; Canagliflozin; Cardiovascular Diseases; Cardiovascular System; Case-Control Studies; Databases, Factual; Diabetes Mellitus, Type 2; Female; Glucagon-Like Peptide 1; Humans; Longitudinal Studies; Male; Middle Aged; Propensity Score; Risk Factors; Sodium-Glucose Transporter 2 Inhibitors; United States | 2020 |
Precision Medicine in Type 2 Diabetes: Using Individualized Prediction Models to Optimize Selection of Treatment.
Despite the known heterogeneity of type 2 diabetes and variable response to glucose lowering medications, current evidence on optimal treatment is predominantly based on average effects in clinical trials rather than individual-level characteristics. A precision medicine approach based on treatment response would aim to improve on this by identifying predictors of differential drug response for people based on their characteristics and then using this information to select optimal treatment. Recent research has demonstrated robust and clinically relevant differential drug response with all noninsulin treatments after metformin (sulfonylureas, thiazolidinediones, dipeptidyl peptidase 4 [DPP-4] inhibitors, glucagon-like peptide 1 [GLP-1] receptor agonists, and sodium-glucose cotransporter 2 [SGLT2] inhibitors) using routinely available clinical features. This Perspective reviews this current evidence and discusses how differences in drug response could inform selection of optimal type 2 diabetes treatment in the near future. It presents a novel framework for developing and testing precision medicine-based strategies to optimize treatment, harnessing existing routine clinical and trial data sources. This framework was recently applied to demonstrate that "subtype" approaches, in which people are classified into subgroups based on features reflecting underlying pathophysiology, are likely to have less clinical utility compared with approaches that combine the same features as continuous measures in probabilistic "individualized prediction" models. Topics: Diabetes Mellitus, Type 2; Dipeptidyl Peptidase 4; Dipeptidyl-Peptidase IV Inhibitors; Female; Glucagon-Like Peptide 1; Glycated Hemoglobin; Humans; Hypoglycemic Agents; Male; Metformin; Precision Medicine; Sulfonylurea Compounds; Thiazolidinediones | 2020 |
Insight in the safety profile of antidiabetic agents glucagon-like peptide-1 agonists and dipeptidyl peptidase-4 inhibitors in daily practice from the patient perspective.
The primary aim of this study was to gain insight in the safety profile of the new antidiabetic agents glucagon-like peptide-1 (GLP-1) agonists and dipeptidyl peptidase-4 (DPP-4) inhibitors in daily practice. The secondary aim was to compare reported adverse drug reactions (ADRs) with information described in the Summary of Product Characteristics (SPC) and to generate knowledge about characteristics, like time to onset and outcome of ADRs. This knowledge is important for drug regulators and clinical practice to understand and manage ADRs better.. A prospective, observational web-based cohort event monitoring study among first-time users of GLP-1 agonists and DPP-4 inhibitors. Patients were recruited through community pharmacies from 2008 to 2016. Participants were invited to complete six web-based questionnaires over a 1-year periods after start of the antidiabetic agent. Questions were posed about patient characteristics, drug use, and ADRs. Data were analyzed using descriptive statistics.. Then, 743 patients were included. Also 62% of all GLP-1 agonist users (total n = 119) and 33% of DPP-4 inhibitor users (total n = 624) experienced an ADR. Of the 10 most reported ADRs, for GLP-1 agonist all, and for DPP-4 inhibitors 8 were described in the drug's SPC. For 45 (91%) ADRs, the patients recovered without discontinuation of the GLP-1 agonist and 79 (73%) ADRs without discontinuation of the DPP-4 inhibitor therapy.. This study gives insight in the safety profile and ADR characteristics of the new antidiabetic agents. This study provides important knowledge for healthcare professionals in managing ADRs and can be directly applied in consultations in daily practice. Topics: Diabetes Mellitus, Type 2; Dipeptidyl-Peptidase IV Inhibitors; Dipeptidyl-Peptidases and Tripeptidyl-Peptidases; Glucagon-Like Peptide 1; Glucagon-Like Peptide-1 Receptor; Humans; Hypoglycemic Agents; Prospective Studies | 2020 |
Prescribing Paradigm Shift? Damned If You Do, Damned If You Don't.
Topics: Cardiology; Cardiovascular Diseases; Diabetes Mellitus, Type 2; Glucagon-Like Peptide 1; Glucose; Humans; Metformin; Prediabetic State; Scotland; Sodium | 2020 |
Sustained release of a GLP-1 and FGF21 dual agonist from an injectable depot protects mice from obesity and hyperglycemia.
There is great interest in identifying a glucagon-like peptide-1 (GLP-1)-based combination therapy that will more effectively promote weight loss in patients with type 2 diabetes. Fibroblast growth factor 21 (FGF21) is a compelling yet previously unexplored drug candidate to combine with GLP-1 due to its thermogenic and insulin-sensitizing effects. Here, we describe the development of a biologic that fuses GLP-1 to FGF21 with an elastin-like polypeptide linker that acts as a sustained release module with zero-order drug release. We show that once-weekly dual-agonist treatment of diabetic mice results in potent weight-reducing effects and enhanced glycemic control that are not observed with either agonist alone. Furthermore, the dual-agonist formulation has superior efficacy compared to a GLP-1/FGF21 mixture, demonstrating the utility of combining two structurally distinct peptides into one multifunctional molecule. We anticipate that these results will spur further investigation into GLP-1/FGF21 multiagonism for the treatment of metabolic disease. Topics: Animals; Delayed-Action Preparations; Diabetes Mellitus, Experimental; Diabetes Mellitus, Type 2; Fibroblast Growth Factors; Glucagon-Like Peptide 1; Glucagon-Like Peptide-1 Receptor; Humans; Hyperglycemia; Mice; Obesity; Peptides | 2020 |
GLP-1 improves adipose tissue glyoxalase activity and capillarization improving insulin sensitivity in type 2 diabetes.
Methylglyoxal was shown to impair adipose tissue capillarization and insulin sensitivity in obese models. We hypothesized that glyoxalase-1 (GLO-1) activity could be diminished in the adipose tissue of type 2 diabetic obese patients. Moreover, we assessed whether such activity could be increased by GLP-1-based therapies in order to improve adipose tissue capillarization and insulin sensitivity. GLO-1 activity was assessed in visceral adipose tissue of a cohort of obese patients. The role of GLP-1 in modulating GLO-1 was assessed in type 2 diabetic GK rats submitted to sleeve gastrectomy or Liraglutide treatment, in the adipose tissue angiogenesis assay and in the HUVEC cell line. Glyoxalase-1 activity was decreased in visceral adipose tissue of pre-diabetic and diabetic obese patients, together with other markers of adipose tissue dysfunction and correlated with increased HbA1c levels. Decreased adipose tissue GLO-1 levels in GK rats were increased by sleeve gastrectomy and Liraglutide, being associated with overexpression of angiogenic and vasoactive factors, as well as insulin receptor phosphorylation (Tyr1161). Moreover, GLP-1 increased adipose tissue capillarization and HUVEC proliferation in a glyoxalase-dependent manner. Lower adipose tissue GLO-1 activity was observed in dysmetabolic patients, being a target for GLP-1 in improving adipose tissue capillarization and insulin sensitivity. Topics: Adipose Tissue; Adult; Aged; Animals; Capillaries; Cells, Cultured; Diabetes Mellitus, Type 2; Disease Models, Animal; Female; Gastrectomy; Glucagon-Like Peptide 1; Glucagon-Like Peptide-1 Receptor; Human Umbilical Vein Endothelial Cells; Humans; Hypoglycemic Agents; Incretins; Insulin Resistance; Lactoylglutathione Lyase; Liraglutide; Male; Middle Aged; Neovascularization, Physiologic; Obesity; Rats, Wistar; Signal Transduction | 2020 |
Switching From Insulin Bolus Treatment to GLP-1 RAs Added to Continued Basal Insulin in People With Type 2 Diabetes on Basal-Bolus Insulin.
Topics: Diabetes Mellitus, Type 2; Glucagon-Like Peptide 1; Glycemic Control; Humans; Hypoglycemic Agents; Insulin | 2020 |
Circulating Levels of the Soluble Receptor for AGE (sRAGE) during Escalating Oral Glucose Dosages and Corresponding Isoglycaemic i.v. Glucose Infusions in Individuals with and without Type 2 Diabetes.
Postprandial glucose excursions are postulated to increase the risk for diabetes complications via the production of advanced glycation end products (AGEs). The soluble receptor of AGEs (sRAGE) likely acts as a decoy receptor, mopping up AGEs, diminishing their capacity for pro-inflammatory and pro-apoptotic signaling. Recent evidence suggests that AGEs and soluble receptor for AGEs (sRAGE) may be altered under postprandial and fasting conditions. Here, we investigated the effects of increasing oral glucose loads during oral glucose tolerance tests (OGTT) and matched isoglycaemic intravenous (i.v.) glucose infusions (IIGI) on circulating concentrations of sRAGE. Samples from eight individuals with type 2 diabetes and eight age-, gender-, and body mass index (BMI)-matched controls, all of whom underwent three differently dosed OGTTs (25 g, 75 g, and 125 g), and three matched IIGIs were utilised (NCT00529048). Serum concentrations of sRAGE were measured over 240 min during each test. For individuals with diabetes, sRAGE area under the curve (AUC Topics: Administration, Oral; Aged; Blood Glucose; Body Mass Index; Diabetes Complications; Diabetes Mellitus, Type 2; Female; Glucagon-Like Peptide 1; Glucose; Glucose Tolerance Test; Homeostasis; Humans; Incretins; Male; Middle Aged; Receptor for Advanced Glycation End Products | 2020 |
Diabetes medications and risk of Parkinson's disease: a cohort study of patients with diabetes.
The elevated risk of Parkinson's disease in patients with diabetes might be mitigated depending on the type of drugs prescribed to treat diabetes. Population data for risk of Parkinson's disease in users of the newer types of drugs used in diabetes are scarce. We compared the risk of Parkinson's disease in patients with diabetes exposed to thiazolidinediones (glitazones), glucagon-like peptide-1 (GLP-1) receptor agonists and dipeptidyl peptidase 4 (DPP4) inhibitors, with the risk of Parkinson's disease of users of any other oral glucose lowering drugs. A population-based, longitudinal, cohort study was conducted using historic primary care data from The Health Improvement Network. Patients with a diagnosis of diabetes and a minimum of two prescriptions for diabetes medications between January 2006 and January 2019 were included in our study. The primary outcome was the first recording of a diagnosis of Parkinson's disease after the index date, identified from clinical records. We compared the risk of Parkinson's disease in individuals treated with glitazones or DPP4 inhibitors and/or GLP-1 receptor agonists to individuals treated with other antidiabetic agents using a Cox regression with inverse probability of treatment weighting based on propensity scores. Results were analysed separately for insulin users. Among 100 288 patients [mean age 62.8 years (standard deviation 12.6)], 329 (0.3%) were diagnosed with Parkinson's disease during the median follow-up of 3.33 years. The incidence of Parkinson's disease was 8 per 10 000 person-years in 21 175 patients using glitazones, 5 per 10 000 person-years in 36 897 patients using DPP4 inhibitors and 4 per 10 000 person-years in 10 684 using GLP-1 mimetics, 6861 of whom were prescribed GTZ and/or DPP4 inhibitors prior to using GLP-1 mimetics. Compared with the incidence of Parkinson's disease in the comparison group (10 per 10 000 person-years), adjusted results showed no evidence of any association between the use of glitazones and Parkinson's disease [incidence rate ratio (IRR) 1.17; 95% confidence interval (CI) 0.76-1.63; P = 0.467], but there was strong evidence of an inverse association between use of DPP4 inhibitors and GLP-1 mimetics and the onset of Parkinson's disease (IRR 0.64; 95% CI 0.43-0.88; P < 0.01 and IRR 0.38; 95% CI 0.17-0.60; P < 0.01, respectively). Results for insulin users were in the same direction, but the overall size of this group was small. The incidence of Parkinson's disease in patie Topics: Aged; Cohort Studies; Diabetes Mellitus, Type 2; Dipeptidyl-Peptidase IV Inhibitors; Female; Glucagon-Like Peptide 1; Humans; Hypoglycemic Agents; Longitudinal Studies; Male; Middle Aged; Parkinson Disease; Risk Factors; United Kingdom | 2020 |
Hypoglycemic effects and mechanism of different molecular weights of konjac glucomannans in type 2 diabetic rats.
Konjac glucomannan (KGM) is a hypoglycemic polysaccharide with a wide range of molecular weights. But study on hypoglycemic effects of KGMs relate to molecular weight is limited. In this study, KGMs with high and medium molecular weights, and the degraded KGMs were analyzed with physicochemical properties, hypoglycemic effects and mechanisms. Results showed that as the molecular weight KGMs decreased, the viscosity decreased, molecular flexibility increased, while chemical groups, crystal structures and main chains showed little change. KGMs with medium molecular weights (KGM-M1, KGM-M2) showed better effects on increasing body weight, decreasing levels of fasting blood glucose, insulin resistance, total cholesterol and low density lipoprotein cholesterol, and enhancing integrity of pancreas and colon, than KGMs with high or low molecular weights (KGM-H, KGM-L) in type 2 diabetic rats. Mechanism analysis suggested that KGM-M1 and KGM-M2 had higher antioxidant and anti-inflammatory activities on elevating superoxide dismutase, decreasing malondialdehyde and tumor necrosis factor-α levels. Moreover, KGM-M1 and KGM-M2 increased gut microbiota diversity, Bacteroidetes/Firmicutes ratio and Muribaculaceae, decreased Romboutsia and Klebsiella, and improved 6 diabetic related metabolites. Combined, KGM-M1 and KGM-M2 showed higher hypoglycemic effects, due to regulatory activities of antioxidant, anti-inflammatory, intestinal microbiota, and relieved metabolic disorders. Topics: Animals; Biomarkers; Blood Glucose; Body Weight; Diabetes Mellitus, Experimental; Diabetes Mellitus, Type 2; Drinking Behavior; Fasting; Feces; Feeding Behavior; Gastrointestinal Microbiome; Glucagon-Like Peptide 1; Glucose Tolerance Test; Hypoglycemic Agents; Insulin Resistance; Lipids; Magnetic Resonance Spectroscopy; Male; Mannans; Molecular Weight; Multivariate Analysis; Oxidative Stress; Phylogeny; Rats, Sprague-Dawley; Scattering, Radiation; Spectrophotometry, Ultraviolet; Spectroscopy, Fourier Transform Infrared; X-Ray Diffraction | 2020 |
Lowering the risk of Parkinson's disease with GLP-1 agonists and DPP4 inhibitors in type 2 diabetes.
Topics: Cohort Studies; Diabetes Mellitus, Type 2; Dipeptidyl Peptidase 4; Dipeptidyl-Peptidase IV Inhibitors; Glucagon-Like Peptide 1; Humans; Hypoglycemic Agents; Parkinson Disease | 2020 |
Effects of the linagliptin, dipeptidyl peptidase-4 inhibitor, on bone fragility induced by type 2 diabetes mellitus in obese mice.
Recently, it has been suggested that glucose-dependent insulinotropic polypeptide (GIP) and glucagon-like peptide 1 (GLP-1), which play important roles in the homeostasis of glucose metabolism, could be involved in the regulation of bone metabolism. Inhibitors of dipeptidyl peptidase 4 (DPP-4), an enzyme that degrades GIP and GLP-1, are widely used clinically as a therapeutic agent for diabetes. However, the effects of DPP-4 inhibitors on bone metabolism remain unclear. In this study, we investigated the effects of linagliptin, a DPP-4 inhibitor, on bone fragility induced by type 2 diabetes mellitus (T2DM). Non-diabetic mice were used as controls, and T2DM mice were administered linagliptin orally on a daily basis for 12 weeks. In T2DM mice, decreased bone mineral density was observed in the lower limb bones along with low serum osteocalcin levels and high serum tartrate-resistant acid phosphatase-5b (TRAP) levels. In contrast, the decreased serum osteocalcin levels and increased serum TRAP levels observed in T2DM mice were significantly suppressed after the administration of linagliptin 30 mg/kg. Bone histomorphometric analysis revealed a reduced osteoid volume and osteoblast surface with an increase in the eroded surface and number of osteoclasts in T2DM mice. This decreased bone formation and increased bone resorption observed in the T2DM mice were suppressed and trabecular bone volume increased following the administration of 30 mg/kg linagliptin. Collectively, these findings suggest that linagliptin may improve the microstructure of trabecular bone by inhibiting both a decrease in bone formation and an increase in bone resorption induced by T2DM. Topics: Administration, Oral; Animals; Bone and Bones; Bone Density; Case-Control Studies; Diabetes Mellitus, Type 2; Dipeptidyl-Peptidase IV Inhibitors; Gastric Inhibitory Polypeptide; Glucagon-Like Peptide 1; Linagliptin; Male; Mice; Mice, Obese; Osteocalcin; Tartrate-Resistant Acid Phosphatase | 2020 |
Pancreatic GLP-1r binding potential is reduced in insulin-resistant pigs.
The insulinotropic capacity of exogenous glucagon like peptide-1 (GLP-1) is reduced in type 2 diabetes and the insulin-resistant obese. We have tested the hypothesis that this response is the consequence of a reduced pancreatic GLP-1 receptor (GLP-1r) density in insulin-resistant obese animals.. GLP-1r density was measured in lean and insulin-resistant adult miniature pigs after the administration of a. GLP-1r binding potential in the obese pancreas was reduced by 75% compared with lean animals. Similar reductions were evident for fat tissue, but not for the duodenum. In the lean group, induced hyperinsulinemia reduced pancreatic GLP-1r density to a level comparable with that of the obese group. The reduction in blood to tissue transfer of the GLP-1r ligand paralleled that of tissue perfusion estimated using. These observations establish that a reduction in abdominal tissue perfusion and a lower GLP-1r density account for the diminished insulinotropic effect of GLP-1 agonists in type 2 diabetes. Topics: Animals; Diabetes Mellitus, Type 2; Glucagon-Like Peptide 1; Glucagon-Like Peptide-1 Receptor; Insulin; Insulin Resistance; Pancreas; Swine | 2020 |
Teadenol A in microbial fermented tea acts as a novel ligand on GPR120 to increase GLP-1 secretion.
Topics: Bodily Secretions; Diabetes Mellitus, Type 2; Fatty Acids; Fermentation; Fermented Foods; Glucagon-Like Peptide 1; HEK293 Cells; Humans; Ligands; Receptors, G-Protein-Coupled; Signal Transduction; Tea | 2020 |
Preferential Gq signaling in diabetes: an electrical switch in incretin action and in diabetes progression?
Patients with type 2 diabetes (T2D) fail to secrete insulin in response to increased glucose levels that occur with eating. Glucagon-like peptide-1 (GLP-1) and glucose-dependent insulinotropic polypeptide (GIP) are two incretins secreted from gastrointestinal cells that amplify insulin secretion when glucose is high. In this issue of the JCI, Oduori et al. explore the role of ATP-sensitive K+ (KATP) channels in maintaining glucose homeostasis. In persistently depolarized β cells from KATP channel knockout (KO) mice, the researchers revealed a shift in G protein signaling from the Gs family to the Gq family. This shift explains why GLP-1, which signals via Gq, but not GIP, which signals preferentially via Gs, can effectively potentiate secretion in islets from the KATP channel-deficient mice and in other models of KATP deficiency, including diabetic KK-Ay mice. Their results provide one explanation for differential insulinotropic potential of incretins in human T2D and point to a potentially unifying model for T2D progression itself. Topics: Animals; Blood Glucose; Diabetes Mellitus, Type 2; Gastric Inhibitory Polypeptide; Glucagon-Like Peptide 1; Humans; Incretins; Insulin; Mice | 2020 |
In type 2 diabetes, GLP-1 RA plus SGLT2 inhibitor vs. either drug alone reduces HbA
Mantsiou C, Karagiannis T, Kakotrichi P, et al. Topics: Blood Glucose; Body Weight; Diabetes Mellitus, Type 2; Glucagon-Like Peptide 1; Glucagon-Like Peptide-1 Receptor; Humans; Hypoglycemic Agents; Pharmaceutical Preparations; Sodium; Sodium-Glucose Transporter 2 Inhibitors; Symporters | 2020 |
Amelioration of non-alcoholic fatty liver disease by sodium butyrate is linked to the modulation of intestinal tight junctions in db/db mice.
The intestinal microenvironment, a potential factor that contributes to the development of non-alcoholic fatty liver disease (NALFD) and type 2 diabetes (T2DM), has a close relationship with intestinal tight junctions (TJs). Here, we show that the disruption of intestinal TJs in the intestines of 16-week-old db/db mice and in high glucose (HG)-cultured Caco-2 cells can both be improved by sodium butyrate (NaB) in a dose-dependent manner in vitro and in vivo. Accompanying the improved intestinal TJs, NaB not only relieved intestine inflammation of db/db mice and HG and LPS co-cultured Caco-2 cells but also restored intestinal Takeda G-protein-coupled (TGR5) expression, resulting in up-regulated serum GLP-1 levels. Subsequently, the GLP-1 analogue Exendin-4 was used to examine the improvement of lipid accumulation in HG and free fatty acid (FFA) co-cultured HepG2 cells. Finally, we used 16-week-old db/db mice to examine the hepatoprotective effects of NaB and its producing strain Clostridium butyricum. Our data showed that NaB and Clostridium butyricum treatment significantly reduced the levels of blood glucose and serum transaminase and markedly reduced T2DM-induced histological alterations of the liver, together with improved liver inflammation and lipid accumulation. These findings suggest that NaB and Clostridium butyricum are a potential adjuvant treatment strategy for T2DM-induced NAFLD; their hepatoprotective effect was linked to the modulation of intestinal TJs, causing the restoration of glucose and lipid metabolism and the improvement of inflammation in hepatocytes. Topics: Animals; Blood Glucose; Butyric Acid; Caco-2 Cells; Cholesterol; Clostridium butyricum; Colon; Cytokines; Diabetes Mellitus, Type 2; Exenatide; Glucagon-Like Peptide 1; Hep G2 Cells; Humans; Hypoglycemic Agents; Inflammation; Intestines; Lipid Metabolism; Liver; Male; Mice; Mice, Inbred C57BL; Non-alcoholic Fatty Liver Disease; Receptors, G-Protein-Coupled; Tight Junctions; Triglycerides | 2020 |
The in vivo digestibility study of banana flour with high content of resistant starch at different ripening stages.
Resistant starch, a functional food ingredient, can improve the nutritional value of food products. In this study, the in vitro digestibility of starch from banana flour at four ripening stages was evaluated. The result showed that the resistant starch content of banana flour at ripening stage 1 was up to 81%. Furthermore, to explore the effect of resistant starch in the body, the in vivo digestibility of banana flour was investigated. The intake of banana flour at ripening stage 1 resulted in a nearly 70% decrease in the homeostasis model assessment of insulin resistance value, compared to that of the model group. By contrast, the genes related to glucokinase were upregulated by 66%, and the expression level of the insulin receptor gene was increased by more than 1.5 times that of the model group. Thus, natural banana flour has potential for controlling type 2 diabetes mellitus. Topics: Blood Glucose; Body Weight; Diabetes Mellitus, Type 2; Digestion; Flour; Functional Food; Glucagon-Like Peptide 1; Homeostasis; Insulin Resistance; Lipids; Musa; Nutritive Value; Resistant Starch; Starch | 2020 |
Have a heart: failure to increase GLP-1 caused by heart failure increases the risk of diabetes.
Incretins represent a group of gut-derived peptide hormones that, at physiological concentrations, potentiate the release of insulin. Work leading to the discovery of incretins began as early as the late 1800s where scientists, including Claude Bernard who is widely considered the father of modern physiology (Rehfeld, J.F. The Origin and Understanding of the Incretin Concept. Front. Endocrinol. (Lausanne) (2018) 9, 387; Robin, E.D. Claude Bernard. Pioneer of regulatory biology. JAMA (1979) 242, 1283-1284), attempted to understand the pancreas as an important organ in the development of diabetes mellitus and blood glucose control. After the seminal work of Paulescu and Banting and Best in the early 1920s that led to the discovery of insulin (Murray I. Paulesco and the isolation of insulin. J. Hist. Med. Allied Sci. (1971) 26, 150-157; Raju T.N. The Nobel Chronicles. 1923: Frederick G. Banting (1891-1941), John J.R. Macleod (1876-1935). Lancet (1998) 352, 1482), attention was turned toward understanding gastrointestinal factors that might regulate insulin secretion. A series of experiments by Jean La Barre showed that a specific fraction of intestinal extract caused a reduction in blood glucose. La Barre posited that the fraction's glucose lowering actions occurred by increasing insulin release, after which he coined the term 'incretin'. In the 1970s, the first incretin was purified, glucose insulinotropic polypeptide (GIP) (Gupta K. and Raja A. Physiology, Gastric Inhibitory Peptide StatPearls Treasure Island (FL); 2020), followed by the discovery of a second incretin in the 1980s, glucagon-like peptide-1 (GLP-1). Interest and understanding of the incretins, has grown since that time. Topics: Blood Glucose; Diabetes Mellitus, Type 2; Gastric Inhibitory Polypeptide; Glucagon-Like Peptide 1; Heart Failure; Humans; Incretins; Insulin; Male | 2020 |
[Obesity without diabetes: the role of hormonal regulation].
Obese patients without diabetes present an interesting phenotype to explore protective mechanisms against type 2 diabetes (T2D) development. In our study we looked for specific hormonal features of obese patients without T2D.. We included 6 groups of patients with different metabolic profiles (n=212): controls with BMI25 kg/m2, HbA1c6%, age 30 years; patients with 25BMI30 kg/m2and HbA1c6%; patients with 25BMI30 kg/m2and HbA1c6%; patients with BMI30 kg/m2and HbA1c6% (+ Obesity - T2D) obese patients without T2D or prediabetes; patients with BMI30 kg/m2and newly-diagnosed T2D/prediabetes, HbA1c6%; patients with known history of T2D on glucose-lowering drugs with BMI30 kg/m2. Insulin, GLP-1, GIP were measured during glucose-tolerance test at 0, 30 and 120 minutes; insulin resistance (IR) was assessed by HOMA-IR.. Waist circumference was bigger in patients with obesity despite their metabolic profile comparing to patients without obesity (p0.001). Waist-to-hip ratio was similar in patients with different metabolic status. According to IR + Obesity - T2D group had intermediate position: IR was higher in that group comparing to people without obesity, but was less that in patients with obesity and HbA1c6% (p0.001). + Obesity - T2D group had the most potent baseline insulin secretion, assessed by НОМА-%band the highest postprandial secretion, measured by insulinogenic index among all patient groups with obesity (p0.001). There was no significant difference in GLP-1 secretion; GIP secretion was higher in patients with BMI30 kg/m2comparing to people with BMI30 kg/m2(p0.01).. Пациенты с ожирением без нарушений углеводного обмена представляет большой интерес для изучения механизмов, защищающих от развития сахарного диабета 2-го типа (СД 2). Цель.Проанализировать особенности гормональной секреции у лиц с ожирением без СД 2. Материалы и методы.В исследование включены 6 групп пациентов с различным метаболическим статусом (n=212): контрольная группа с индексом массы тела (ИМТ)25 кг/м2, гликированным гемоглобином (HbA1c)6%, возраст 30 лет; пациенты с ИМТ 25ИМТ30 кг/м2и HbA1c6%; пациенты с ИМТ 25ИМТ30 кг/м2и HbA1c6%; пациенты с ИМТ30 кг/м2и HbA1c6% (+ ожирение - СД) группа с ожирением без СД 2 и предиабета; пациенты с ИМТ30 кг/м2и впервые выявленным HbA1c6%; пациенты с известным СД 2 на сахароснижающих препаратах с ИМТ30 кг/м2. В ходе глюкозотолерантного теста (0, 30, 120 мин) определены инсулин, глюкозозависимый инсулинотропный полипептид 1-го типа, глюкозозависимый инсулинотропный полипептид, рассчитан показатель HOMA-IR. Результаты.Окружность талии отмечена больше у пациентов с ожирением вне зависимости от метаболических нарушений по сравнению с лицами без ожирения (p0,001). Соотношение окружностей талии и бедер не позволяло дифференцировать пациентов с разными метаболическими рисками. В группе + ожирение - СД инсулинорезистентность выше, чем у пациентов без ожирения, но ниже, чем у пациентов с ожирением и HbA1c6% (p0,001). Эта группа также имела наиболее высокие показатели базальной (НОМА-%) и стимулированной секреции инсулина (индекс инсулиногенности) среди всех пациентов с ИМТ30 кг/м2(p0,001). Секреция ГПП-1 не отличалась, секреция ГИП отмечена выше в группах с ИМТ30 кг/м2по сравнению с лицами с ИМТ30 кг/м2(p0,01). Заключение.Отличие фенотипа пациентов с ожирением без СД 2 от лиц с СД 2 заключалось в менее выраженной инсулинорезистентности и более сохранной базальной и стимулированной секреции инсулина, достаточной для поддержания нормогликемии. Topics: Blood Glucose; Diabetes Mellitus, Type 2; Glucagon-Like Peptide 1; Humans; Insulin; Insulin Resistance; Obesity | 2020 |
Glucagon-like peptide 1 and its association with dipeptidyl peptidase IV in subjects with various degrees of glucose tolerance.
Dipeptidyl peptidase IV (DPP-4) and Glucagon like peptide 1 (GLP-1) has profound effect on insulin and glucagon secretion; ultimately decreasing glucose levels. We find out the association of GLP-1 levels and DPP-4 in normal, impaired and newly diagnose type 2 diabetic glucose tolerance. Prospective case control study was conducted at Department of Physiology, Baqai Medical University by the collaboration of Baqai Institute of Diabetology and Endocrinology; Karachi-Pakistan. Study groups were categorized into three groups Control, Impaired glucose tolerant (IGT) and newly diagnose type 2 diabetes mellitus (NDD). Biochemical parameters were estimated by international standard protocols. Logistic regression analysis and Chi square test with statistical significance at p value <0.05 were applied. DPP-4 concentrations were significantly lower in NDD participants compared to control and IGT participants (p=0.01), whereas GLP-1 levels were significantly higher in Control than Impaired glucose tolerant and NDD (p = 0.013). GLP1 levels and SBP were also found to be positively correlated with serum DPP4 levels in NDD group (p<0.05). GLP1 and DPP4 levels in NDD group (p<0.05) and in controls (p<0.001) respectively showed strong significant positive correlation. Effective correlation between GLP1 and DPP4 was found as both contribute to control hyperglycemia in NDD and impaired glucose tolerant people. Topics: Case-Control Studies; Diabetes Mellitus, Type 2; Dipeptidyl Peptidase 4; Glucagon-Like Peptide 1; Glucose Intolerance; Glucose Tolerance Test; Humans; Logistic Models; Prospective Studies | 2020 |
Magnitude of slowing gastric emptying by glucagon-like peptide-1 receptor agonists determines the amelioration of postprandial glucose excursion in Japanese patients with type 2 diabetes.
Pharmacological levels of glucagon-like peptide-1 (GLP-1) can decelerate gastric emptying (GE) and reduce postprandial glucose levels. Most previous studies have used liquid meals to evaluate GE. We evaluated the effects of GLP-1 receptor agonists (GLP-1 RAs) on GE and postprandial glucose excursion in Japanese type 2 diabetes mellitus patients using a combination of solid and liquid meals.. In this single-center, prospective, open-label study, nine healthy individuals and 17 patients with type 2 diabetes mellitus consumed a 460-kcal combination of a solid and liquid meal labeled with. There were no differences in the average GE coefficient (GEC) and lag time between the healthy and type 2 diabetes mellitus groups. However, the type 2 diabetes mellitus group showed larger GEC variations (P < 0.05). The coefficient of variation of R-R intervals was a significant predictor of GEC in type 2 diabetes mellitus patients (P < 0.01). The short-acting GLP-1 RA reduced the GEC at 1 month (P = 0.012), whereas the long-acting GLP-1 RA did not significantly change the GEC after treatment. A positive relationship was observed between postprandial glucose excursion from T. The reduction in GE rate by the administration of GLP-1 RAs can predict the improvement in postprandial glucose excursion in type 2 diabetes mellitus patients. Topics: Adult; Aged; Asian People; Blood Glucose; Breath Tests; Diabetes Mellitus, Type 2; Female; Gastric Emptying; Glucagon-Like Peptide 1; Humans; Japan; Male; Middle Aged; Postprandial Period; Prospective Studies | 2020 |
Agonist-induced membrane nanodomain clustering drives GLP-1 receptor responses in pancreatic beta cells.
The glucagon-like peptide-1 receptor (GLP-1R), a key pharmacological target in type 2 diabetes (T2D) and obesity, undergoes rapid endocytosis after stimulation by endogenous and therapeutic agonists. We have previously highlighted the relevance of this process in fine-tuning GLP-1R responses in pancreatic beta cells to control insulin secretion. In the present study, we demonstrate an important role for the translocation of active GLP-1Rs into liquid-ordered plasma membrane nanodomains, which act as hotspots for optimal coordination of intracellular signaling and clathrin-mediated endocytosis. This process is dynamically regulated by agonist binding through palmitoylation of the GLP-1R at its carboxyl-terminal tail. Biased GLP-1R agonists and small molecule allosteric modulation both influence GLP-1R palmitoylation, clustering, nanodomain signaling, and internalization. Downstream effects on insulin secretion from pancreatic beta cells indicate that these processes are relevant to GLP-1R physiological actions and might be therapeutically targetable. Topics: Animals; Cell Membrane; CHO Cells; Cluster Analysis; Cricetulus; Cyclic AMP; Diabetes Mellitus, Type 2; Endocytosis; Glucagon-Like Peptide 1; Glucagon-Like Peptide-1 Receptor; HEK293 Cells; Humans; Insulin; Insulin Secretion; Insulin-Secreting Cells; Lipoylation; Signal Transduction | 2019 |
Sitagliptin favorably modulates immune-relevant pathways in human beta cells.
Type 2 diabetes (T2D) is a condition characterized by hyperglycemia and chronic complications. Antidiabetic drugs and lifestyle interventions are the current gold standard therapy for T2D; current therapies, however, can only delay long-term diabetic complications and can additionally be associated with beta cell failure. While the mechanism of beta cell failure is well-studied, little is known about the immunological and inflammatory events associated with antidiabetic agents. Here we studied the effects of three antidiabetic drugs (Metformin, Sitagliptin, and Liraglutide) on immune-relevant pathways in a human beta cell line. Costimulatory molecule expression, cytokine secretion, and gene expression profiles were evaluated at different time points following challenge with the aforementioned antidiabetic agents. Our results showed that these three antidiabetic agents, particularly Sitagliptin, downregulate HLA Class I and II expression and upregulate the immune-regulatory molecules PD-L1 and CTLA4. Metformin and Liraglutide were shown to elicit significantly greater release of TNFa, IL-6, and GM-CSF, while Sitagliptin had a lesser effect on pro-inflammatory cytokine production. Gene expression analysis confirmed the aforementioned observations and also demonstrated upregulation of NOS2, SIRT1, SITR3, POLRMT, MRPL43 and NFkB with antidiabetic agents. We conclude that Sitagliptin most effectively modulates beneficial immune-relevant pathways in a human beta cell line. Topics: Cell Line; Diabetes Mellitus, Type 2; Gene Expression; Glucagon-Like Peptide 1; Glycated Hemoglobin; Humans; Hypoglycemic Agents; Immunologic Factors; Inflammation; Insulin-Secreting Cells; Interleukin-6; Liraglutide; Metformin; Signal Transduction; Sitagliptin Phosphate; Tumor Necrosis Factor-alpha; Up-Regulation | 2019 |
The possible synergistic action of sex hormones and glucagon-like peptide-1 (GLP-1) agonists on body mass decline in patients with type 2 diabetes mellitus.
Adiposity is a chronic disease and one of the major modifiable risk factors for the development of type 2 diabetes mellitus (T2DM). Its prevalence in the world could be considered epidemic with 80% of patients with T2DM being obese. Novel antidiabetic drugs, such as glucagone-like peptide-1 (GLP-1) agonists have demonstrated benefitial effect on weight reduction. Nevertheless, in the last decades the need for new therapeutic strategies in the management of adiposity have emerged. Both adiposity and T2DM have negative effect on hypothalamic-pituitary-gonadal axis. Conversely, it has been known that sex hormone replacement therapy improves metabolic parameters in hypogonadal subjects. Recent research has found potential therapeutic effect of combination therapies with sex hormones and GLP-1 agonists in reducing body weight. Based on the aforementioned, we hypothesize that there is a possible synergistic effect of GLP-1 agonists and sex hormones on body mass reduction in patients with type 2 diabetes. The possible additional effect of sex hormones on weight loss could contribute to more effective treatment of T2DM and its complications. Topics: Adiposity; Anti-Obesity Agents; Appetite Depressants; Diabetes Mellitus, Type 2; Drug Synergism; Estradiol; Female; Glucagon; Glucagon-Like Peptide 1; Gonadal Steroid Hormones; Humans; Hypoglycemic Agents; Insulin; Male; Menstrual Cycle; Models, Biological; Overweight; Pancreas; Risk Factors; Secretory Rate; Testosterone; Weight Loss | 2019 |
Dipeptidyl peptidase-4 inhibitors can inhibit angiotensin converting enzyme.
Angiotensin-1 converting enzyme inhibitors (ACEIs) improve insulin sensitivity. Inhibitors of dipeptidyl peptidase-4 (DPP-4) are anti-diabetic drugs with several cardio-renal effects. Both ACE and DPP-4 share common features. Thus, we tested if they could be inhibited by one inhibitor. First, in silico screening was used to investigate the ability of different DPP-4 inhibitors or ACEIs to interact with DPP-4 and ACE. The results of screening were then extrapolated into animal study. Fifty Sprague Dawley rats were randomly assigned into 5 groups treated with vehicle, captopril, enalapril, linagliptin or sitagliptin. Both low and high doses of each drug were tested. Baseline blood samples and samples at days 1, 8, 10, 14 were used to measure plasma DPP-4 and ACE activities and angiotensin II levels. Active glucagon-like peptide-1 (GLP-1) levels were measured after oral glucose challenge. All tested DPP-4 inhibitors could interact with ACE at a relatively reasonable binding energy while most of the ACEIs only interacted with DPP-4 at a predicted high inhibition constant. In rats, high dose of sitagliptin was able to inhibit ACE activity and reduce angiotensin II levels while linagliptin had only a mild effect. ACEIs did not significantly affect DPP-4 activity or prevent GLP-1 degradation. It seems that some DPP-4 inhibitors could inhibit ACE and this could partially explain the cardio-renal effects of these drugs. Further studies are required to determine if such inhibition could take place in clinical settings. Topics: Angiotensin II; Angiotensin-Converting Enzyme Inhibitors; Animals; Captopril; Diabetes Mellitus, Type 2; Dipeptidyl Peptidase 4; Dipeptidyl-Peptidase IV Inhibitors; Dose-Response Relationship, Drug; Drug Evaluation, Preclinical; Enalapril; Female; Glucagon-Like Peptide 1; Humans; Hypertension; Linagliptin; Peptidyl-Dipeptidase A; Protein Binding; Rats; Rats, Sprague-Dawley; Sitagliptin Phosphate | 2019 |
Disparities in glycaemic control, monitoring, and treatment of type 2 diabetes in England: A retrospective cohort analysis.
Disparities in type 2 diabetes (T2D) care provision and clinical outcomes have been reported in the last 2 decades in the UK. Since then, a number of initiatives have attempted to address this imbalance. The aim was to evaluate contemporary data as to whether disparities exist in glycaemic control, monitoring, and prescribing in people with T2D.. A T2D cohort was identified from the Royal College of General Practitioners Research and Surveillance Centre dataset: a nationally representative sample of 164 primary care practices (general practices) across England. Diabetes healthcare provision and glucose-lowering medication use between 1 January 2012 and 31 December 2016 were studied. Healthcare provision included annual HbA1c, renal function (estimated glomerular filtration rate [eGFR]), blood pressure (BP), retinopathy, and neuropathy testing. Variables potentially associated with disparity outcomes were assessed using mixed effects logistic and linear regression, adjusted for age, sex, ethnicity, and socioeconomic status (SES) using the Index of Multiple Deprivation (IMD), and nested using random effects within general practices. Ethnicity was defined using the Office for National Statistics ethnicity categories: White, Mixed, Asian, Black, and Other (including Arab people and other groups not classified elsewhere). From the primary care adult population (n = 1,238,909), we identified a cohort of 84,452 (5.29%) adults with T2D. The mean age of people with T2D in the included cohort at 31 December 2016 was 68.7 ± 12.6 years; 21,656 (43.9%) were female. The mean body mass index was 30.7 ± SD 6.4 kg/m2. The most deprived groups (IMD quintiles 1 and 2) showed poorer HbA1c than the least deprived (IMD quintile 5). People of Black ethnicity had worse HbA1c than those of White ethnicity. Asian individuals were less likely than White individuals to be prescribed insulin (odds ratio [OR] 0.86, 95% CI 0.79-0.95; p < 0.01), sodium-glucose cotransporter-2 (SGLT2) inhibitors (OR 0.68, 95% CI 0.58-0.79; p < 0.001), and glucagon-like peptide-1 (GLP-1) agonists (OR 0.37, 95% CI 0.31-0.44; p < 0.001). Black individuals were less likely than White individuals to be prescribed SGLT2 inhibitors (OR 0.50, 95% CI 0.39-0.65; p < 0.001) and GLP-1 agonists (OR 0.45, 95% CI 0.35-0.57; p < 0.001). Individuals in IMD quintile 5 were more likely than those in the other IMD quintiles to have annual testing for HbA1c, BP, eGFR, retinopathy, and neuropathy. Black individuals were less likely than White individuals to have annual testing for HbA1c (OR 0.89, 95% CI 0.79-0.99; p = 0.04) and retinopathy (OR 0.82, 95% CI 0.70-0.96; p = 0.011). Asian individuals were more likely than White individuals to have monitoring for HbA1c (OR 1.10, 95% CI 1.01-1.20; p = 0.023) and eGFR (OR 1.09, 95% CI 1.00-1.19; p = 0.048), but less likely f. Our findings suggest that disparity in glycaemic control, diabetes-related monitoring, and prescription of newer therapies remains a challenge in diabetes care. Both SES and ethnicity were important determinants of inequality. Disparities in glycaemic control and other areas of care may lead to higher rates of complications and adverse outcomes for some groups. Topics: Aged; Aged, 80 and over; Black People; Blood Glucose; Diabetes Mellitus, Type 2; England; Female; Glucagon-Like Peptide 1; Glycated Hemoglobin; Healthcare Disparities; Humans; Hyperglycemia; Hypoglycemic Agents; Male; Middle Aged; Primary Health Care; Retrospective Studies; Sodium-Glucose Transporter 2 Inhibitors; Treatment Outcome; White People | 2019 |
Topics: Administration, Oral; Diabetes Mellitus, Type 2; Glucagon-Like Peptide 1; Humans; Hypoglycemic Agents | 2019 |
Prolonged half-life of small-sized therapeutic protein using serum albumin-specific protein binder.
Many small-sized proteins and peptides, such as cytokines and hormones, are clinically used for the treatment of a variety of diseases. However, their short half-life in blood owing to fast renal clearance usually results in a low therapeutic efficacy and frequent dosing. Here we present the development of a human serum albumin (HSA)-specific protein binder with a binding affinity of 4.3nM through a phage display selection and modular evolution approach to extend the blood half-life of a small-sized therapeutic protein. As a proof-of-concept, the protein binder composed of LRR (Leucine-rich repeat) modules was genetically fused to the N-terminus of Glucagon-like Peptide-1 (GLP-1). The fused GLP-1 was shown to have a significantly improved pharmacokinetic property: The terminal half-life of the fused GLP-1 increased to approximately 10h, and the area under the curve was 5-times higher than that of the control. The utility and potential of our approach was demonstrated by the efficient control of the blood glucose level in type-2 diabetes mouse models using the HSA-specific protein binder-fused GLP-1 over a prolonged time period. The present approach can be effectively used in enhancing the efficacy of small-sized therapeutic proteins and peptides through an enhanced blood circulation time. Topics: Animals; Blood Glucose; Diabetes Mellitus, Experimental; Diabetes Mellitus, Type 2; Glucagon-Like Peptide 1; Half-Life; Humans; Hypoglycemic Agents; Leucine-Rich Repeat Proteins; Male; Mice; Mice, Inbred BALB C; Mice, Inbred C57BL; Particle Size; Peptides; Protein Binding; Proteins; Serum Albumin, Human | 2019 |
Reduction of cardiac and renal dysfunction by new inhibitor of DPP4 in diabetic rats.
Increased mortality due to type 2 diabetes mellitus (T2DM) has been associated with renal and/or cardiovascular dysfunction. Dipeptidyl dipeptidase-4 inhibitors (iDPP-4s) may exert cardioprotective effects through their pleiotropic actions via glucagon-like peptide 1-dependent mechanisms. In this study, the pharmacological profile of a new iDPP-4 (LASSBio-2124) was investigated in rats with cardiac and renal dysfunction induced by T2DM.. T2DM was induced in rats by 2 weeks of a high-fat diet followed by intravenous injection of streptozotocin. Metabolic disturbance and cardiac, vascular, and renal dysfunction were analyzed in the experimental groups.. Sitagliptin and LASSBio-2124 administration after T2DM induction reduced elevated glucose levels to 319.8 ± 13.2 and 279.7 ± 17.8 mg/dL, respectively (p < 0.05). LASSBio-2124 also lowered the cholesterol and triglyceride levels from 76.8 ± 8.0 to 42.7 ± 3.2 mg/dL and from 229.7 ± 25.4 to 100.7 ± 17.1 mg/dL, in diabetic rats. Sitagliptin and LASSBio-2124 reversed the reduction of the plasma insulin level. LASSBio-2124 recovered the increased urinary flow in diabetic animals and reduced 24-h proteinuria from 23.7 ± 1.5 to 13.3 ± 2.8 mg (p < 0.05). It also reduced systolic and diastolic left-ventricular dysfunction in hearts from diabetic rats.. The effects of LASSBio-2124 were superior to those of sitagliptin in the cardiovascular systems of T2DM rats. This new prototype showed promise for the avoidance of comorbidities in a T2DM experimental model, and thus may constitute an innovative therapeutic agent for the treatment of these conditions in the clinical field in future. Topics: Animals; Diabetes Mellitus, Experimental; Diabetes Mellitus, Type 2; Dipeptidyl Peptidase 4; Dipeptidyl-Peptidase IV Inhibitors; Glucagon-Like Peptide 1; Heart; Kidney Diseases; Male; Rats; Rats, Wistar; Sitagliptin Phosphate; Streptozocin; Ventricular Dysfunction, Left | 2019 |
Glucagon-like peptide-1 receptor agonist exendin-4 mitigates lipopolysaccharide-induced inflammatory responses in RAW264.7 macrophages.
Macrophages play a critical role in the immune response against pathogen invasion and injury. However, under pathological stress, macrophages could have aberrant roles and contribute to the pathogenesis of inflammatory associated diseases. Exenatide is a glucagon-like peptide 1(GLP-1) agonist, which belongs to the family of synthetic exendin-based incretin mimetic. Exendin related compounds reduce glucose levels in type 2 diabetes patients. The purpose of this study was to examine the anti-inflammatory effects of exendin-4 in LPS-induced activation of macrophages. We show that exendin-4 inhibits LPS-induced expression of inflammatory mediators (iNOS, COX-2, PGE2 and NO) and pro-inflammatory cytokines (TNF-α, IL-1β, and IL-6) in RAW264.7 macrophages. Exendin-4 pretreatment mitigates LPS induced cellular ROS production. Mechanistically, Exendin-4 suppresses the LPS-induced activation of the JNK and AP-1 pathway. Furthermore, exendin-4 suppresses both nuclear p65 accumulation and transfected NF-κB promoter activity, indicating it inhibits the activation of the NF-κB pathway. Our study demonstrates that the GLP-1 agonist exendin-4 has a potent anti-inflammatory effect independent on its glucose reducing ability, and exendin-4 has the potential implication to treat inflammatory associated diseases. Topics: Animals; Anti-Inflammatory Agents; Cell Line; Cyclooxygenase 2; Cytokines; Diabetes Mellitus, Type 2; Exenatide; Glucagon-Like Peptide 1; Inflammation; Lipopolysaccharides; Macrophages; Mice; NF-kappa B; Nitric Oxide; RAW 264.7 Cells; Reactive Oxygen Species; Signal Transduction; Tumor Necrosis Factor-alpha | 2019 |
Physiology of the Incretin Hormones, GIP and GLP-1-Regulation of Release and Posttranslational Modifications.
The focus of this article is on the analysis of the release and postrelease fate of the incretin hormones, glucagon-like peptide-1 and glucose-dependent insulinotropic polypeptide. Their actions are dealt with to the extent that they are linked to their secretion. For both hormones, their posttranslational processing is analyzed in detail, because of its importance for the understanding of the molecular heterogeneity of the hormones. Methods of analysis, in particular regarding measurements in plasma from in vivo experiments, are discussed in detail in relation to the molecular heterogeneity of the hormones, and the importance of the designations "total" versus "intact hormones" is explained. Both hormones are substrates for the ubiquitous enzyme, dipeptidyl peptidase-4, which inactivates the peptides with dramatic consequences for their physiological spectrum of activities. The role of endogenous and exogenous antagonists of the receptors is discussed in detail because of their importance for the elucidation of the physiology and pathophysiology of the hormones. Regarding the actual secretion, the most important factors are discussed, including gastric emptying rate and the influence of the different macronutrients. Additional factors discussed are the role of bile, paracrine regulation, the role of the microbiota, pharmaceuticals, and exercise. Finally, the secretion during pathological conditions is discussed. © 2019 American Physiological Society. Compr Physiol 9:1339-1381, 2019. Topics: Cytokines; Diabetes Mellitus, Type 2; Glucagon-Like Peptide 1; Glucose; Humans; Incretins; Protein Processing, Post-Translational | 2019 |
Comparison of serum amylase level between dipeptidyl peptidase-4 inhibitor and GLP-1 analog administration in patients with type 2 diabetes mellitus.
We monitored serum amylase level in patients with type 2 diabetes mellitus (T2DM) prescribed either dipeptidyl peptidase-4 inhibitor or GLP-1 analog (GLP-1 group) as monotherapy. Patients were treated for a 36-month period. All subjects were non-smoker and did not take any alcoholic beverages. Forty-nine patients were prescribed DPP4is (DPP4i group), and 9 patients were prescribed GLP-1 analogs (GLP-1 group). The median of serum amylase levels in DPP4is group was 73 U/mL and the median of serum amylase levels in GLP-1 analog group was 76. Thus, there was no statistical significance between the two groups. However, the increased serum amylase levels in the three patients were observed only in the DPP4is group. One strength of the current study is that the serum amylase level was consistently measured in all subjects, and those subjects had been treated with either DPP4is or GLP-1 analogs as monotherapy. The incidence of elevated serum pancreatic amylase levels beyond normal range was calculated as 6.12% in the DPP4is group although the frequency was 0% in the GLP-1 analog group. Measurement of serum amylase consistently might have clinical meaning to catch the onset of pancreatitis and minimize the side effects due to DPP4is and GLP-1 analogs. Topics: Adult; Aged; Aged, 80 and over; Amylases; Diabetes Mellitus, Type 2; Dipeptidyl-Peptidase IV Inhibitors; Female; Glucagon-Like Peptide 1; Humans; Hypoglycemic Agents; Male; Middle Aged | 2019 |
Does evidence matter? Comparative effectiveness research and prescribing of Type 2 diabetes mellitus drugs.
Topics: Comparative Effectiveness Research; Diabetes Mellitus, Type 2; Dipeptidyl-Peptidase IV Inhibitors; Drug Prescriptions; Exenatide; Glucagon-Like Peptide 1; Glycated Hemoglobin; Humans; Hypoglycemic Agents; Liraglutide; Marketing of Health Services; Practice Patterns, Physicians'; Retrospective Studies; Sitagliptin Phosphate; United States | 2019 |
SGLT-2 inhibitors were not linked to severe or nonsevere UTIs vs DPP-4 inhibitors or GLP-1 agonists.
Topics: Cohort Studies; Diabetes Mellitus, Type 2; Dipeptidyl-Peptidase IV Inhibitors; Glucagon-Like Peptide 1; Humans; Hypoglycemic Agents; Sodium-Glucose Transporter 2 Inhibitors; Urinary Tract Infections | 2019 |
Why are there Variations in the Responses of Glucagon-like Peptide-1 Agonists among the Type 2 Diabetic Patients?
Topics: Diabetes Mellitus, Type 2; Glucagon-Like Peptide 1; Glucagon-Like Peptide-1 Receptor; Humans; Pharmacogenetics; Polymorphism, Single Nucleotide | 2019 |
Endogenous glucagon-like peptide-1 system response is impaired during ST-elevation myocardial infarction in type 2 diabetes patients.
We previously demonstrated increased glucagon-like peptide-1 (GLP-1) secretion during acute ST elevation myocardial infarction (STEMI) in non-diabetic (ND) patients. Whether the endogenous GLP-1 system response is different in patients with type 2 diabetes (T2D) during STEMI is unknown. Patients with STEMI (20 ND, 13 T2D) and 3 control groups (non-STEMI [14 ND, 13 T2D], stable angina pectoris [SAP] [8 ND, 10 T2D] patients and healthy subjects) (n = 25) were studied. Plasma levels of total and active GLP-1 and soluble dipeptidyl peptidase-4 (sDPP4) were estimated by enzyme-linked immunosorbent assay on admission and at 24 and 48 hours after percutaneous coronary intervention in all patients. Sharply elevated levels of total and active GLP-1 were found in ND STEMI patients at 24 h (P < 0.05 and P < 0.005, respectively), but not in T2D STEMI patients. All patients demonstrated decreased sDPP4 levels compared with healthy controls (P < 0.0005) accompanied by increased active/total GLP-1 ratio regardless of their ischemic state. These data demonstrate that T2D patients fail to further upregulate their endogenous GLP-1 system during STEMI. This may underlie their worse cardiovascular outcome. Topics: Adult; Aged; Aged, 80 and over; Diabetes Mellitus, Type 2; Dipeptidyl Peptidase 4; Female; Glucagon-Like Peptide 1; Humans; Male; Middle Aged; ST Elevation Myocardial Infarction | 2019 |
Probiotic Lactobacillus gasseri SBT2055 improves insulin secretion in a diabetic rat model.
The probiotic Lactobacillus gasseri SBT2055 (LG2055) has a protective effect against metabolic syndrome in rats and humans. Metabolic syndrome increases the risk of type 2 diabetes mellitus. In this study, Goto-Kakizaki rats were used as a diabetic model and fed diets containing LG2055-fermented or nonfermented skim milk for 4 wk. Indices of diabetes such as blood glucose levels, serum glucagon levels, plasma levels of insulin, C-peptide, and glucagon-like peptide-1, tissue glycogen contents, and pancreatic mRNA levels were measured. The plasma C-peptide levels and pancreatic mRNA levels of insulin genes (Ins1 and Ins2) and Pdx1 (a transcriptional factor of insulin genes) were increased in LG2055 diet-fed rats. The increase in insulin secretion corresponded to an improvement in serum and pancreatic inflammatory status, associated with decreases in serum levels of serum amyloid P and pancreatic levels of granulocyte colony-stimulating factor. Insulin resistance in Goto-Kakizaki rats was ameliorated by increased glycogen storage in the liver and quadriceps femoris muscles and decreased serum free fatty acid levels. This improvement may be related to the increased cecal production of short-chain fatty acids. In conclusion, dietary LG2055 improved insulin secretion in diabetic rats by improving the inflammatory status in the pancreas and serum. Topics: Animals; Blood Glucose; Cecum; Diabetes Mellitus, Type 2; Diet; Fatty Acids, Volatile; Glucagon-Like Peptide 1; Glycogen; Humans; Insulin; Insulin Resistance; Insulin Secretion; Lactobacillus gasseri; Liver; Male; Muscle, Skeletal; Probiotics; Rats | 2019 |
A low GLP-1 response among patients treated for acute organophosphate and carbamate poisoning: a comparative cross-sectional study from an agrarian region of Sri Lanka.
Higher incidence of diabetes along with increased use of pesticides is seen in Southeast Asia. Recent hypothesis postulated a link between acetylcholinesterase inhibitor insecticides and type 2 diabetes through the GLP-1 pathway. This study compares the GLP-1 response between groups with low and high red blood cell acetylcholinesterase (RBC-AChE) activity. A comparative cross-sectional study was conducted amongst patients who were within 3 months after an acute organophosphate or carbamate poisoning (acute group) and amongst vegetable farmers with low (chronic group) and high (control group) RBC-AChE activity. Acute (366 mU/μM Hb) and chronic (361 mU/μM Hb) groups had significantly lower RBC-AChE activity in comparison to the control (471 mU/μM Hb) group (P < 0.0001). Only the acute group, which has had atropine therapy, showed a significantly lower 120 min value in comparison to the control group (P = 0.0028). Also, the acute group had significantly low late (P = 0.0287) and total (P = 0.0358) responses of GLP-1 in comparison to the control group. The findings of the study allude towards attenuation of GLP-1 response amongst patients after acute organophosphate and carbamate poisoning. The possibility of an atropine-mediated attenuation of GLP-1 response was discussed. Topics: Acetylcholinesterase; Acute Disease; Adult; Atropine; Carbamates; Chronic Disease; Cross-Sectional Studies; Diabetes Mellitus, Type 2; Dose-Response Relationship, Drug; Erythrocytes; Female; Glucagon-Like Peptide 1; Humans; Incidence; Incretins; Insecticides; Male; Middle Aged; Occupational Exposure; Organophosphate Poisoning; Sri Lanka | 2019 |
Long circulating genetically encoded intrinsically disordered zwitterionic polypeptides for drug delivery.
The clinical utility of many peptide and protein drugs is limited by their short in-vivo half-life. To address this limitation, we report a new class of polypeptide-based materials that have a long plasma circulation time. The design of these polypeptides is motivated by the hypothesis that incorporating a zwitterionic sequence, within an intrinsically disordered polypeptide motif, would impart "stealth" behavior to the polypeptide and increase its plasma residence time, a behavior akin to that of synthetic stealth polymers. We designed these zwitterionic polypeptides (ZIPPs) with a repetitive (VPX Topics: Amino Acid Sequence; Animals; Diabetes Mellitus, Experimental; Diabetes Mellitus, Type 2; Drug Delivery Systems; Elastin; Glucagon-Like Peptide 1; Intrinsically Disordered Proteins; Male; Mice, Inbred C57BL; Peptides; Tissue Distribution | 2019 |
Farnesoid X receptor interacts with cAMP response element binding protein to modulate glucagon-like peptide-1 (7-36) amide secretion by intestinal L cell.
Type II diabetes is a complex, chronic, and progressive disease. Glucagon-like peptide-1 (7-36) amide (GLP-1) is a gut hormone released from the L cells which stimulate insulin secretion and promotes insulin gene expression and β-cell growth and differentiation. Elevated levels of hormones secreted by L cells are an essential reason for diabetes improvement. GLP-1 secretion has been reported to be regulated by farnesoid X receptor (FXR), a transcriptional sensor for bile acids which also acts on glucose metabolism. Herein, we attempted to evaluate the effect of FXR on GLP-1 secretion in mouse enteroendocrine L cell line, namely STC-1, and to investigate the underlying mechanism. FXR inversely regulated GLP-1 secretion in STC-1. A total of 24 nonredundant human proteins were shown to be related to FXR by BioGRID; KEGG pathway analysis revealed that FXR was related to glucagon signaling pathway, particularly with the transcriptional activators CREB, PGC1α, Sirt1, and CBP. CREB could positively regulate GLP-1 secretion in STC-1 cells. FXR combined with CREB to inhibit its transcriptional activity, thus inhibiting proprotein convertase subtilisin/kexin type 1 protein level and GLP-1 secretion. In the present study, we demonstrated a negative regulation of GLP-1 secretion by FXR in L cell line, STC-1; FXR exerts its function in L cells through interacting with CREB, a crucial transcriptional regulator of cAMP-CREB signaling pathway, to inhibit its transcriptional activity. Targeting FXR to rescue GLP-1 secretion may be a promising strategy for type II diabetes. Topics: Animals; Cell Line; Cyclic AMP; Cyclic AMP Response Element-Binding Protein; Diabetes Mellitus, Type 2; Enteroendocrine Cells; Gene Expression Regulation; Glucagon-Like Peptide 1; Humans; Insulin-Secreting Cells; Mice | 2019 |
Gut Hormone Responses to Mixed Meal Test in New-Onset Prediabetes/Diabetes After Acute Pancreatitis.
The study was aimed to investigate gut hormone responses to mixed meal test in individuals with new-onset prediabetes or diabetes after acute pancreatitis (cases) compared with healthy controls, and the effect of body fat parameters. A total of 29 cases and 29 age- and sex-matched healthy controls were recruited. All participants were given standard mixed meal drink and blood samples were collected to measure dipeptidyl peptidase IV, gastric inhibitory peptide, glucagon like peptide-1, insulin, oxyntomodulin, and peptide YY. Body fat parameters were measured using magnetic resonance imaging. Repeated measures and linear regression analyses were conducted in unadjusted and adjusted models. Gastric inhibitory peptide levels were significantly higher whereas oxyntomodulin levels were significantly lower in cases compared with controls in both the unadjusted (p<0.001 and p<0.001, respectively) and adjusted (p<0.001 and p<0.001, respectively) models. In cases, liver fat % contributed up to 13.4% (vs. 2.9% in controls) to variance in circulating levels of gastric inhibitory peptide whereas body mass index - up to 20.8% (vs. 9.9% in controls) in circulating levels of oxyntomodulin. New-onset prediabetes/diabetes after acute pancreatitis is characterised by increased levels of gastric inhibitory peptide and decreased levels of oxyntomodulin. Further, liver fat % and body mass index appear to be the body fat parameters that contribute most significantly to gastric inhibitory peptide and oxyntomodulin levels, respectively. Topics: Adult; Aged; Blood Glucose; Diabetes Mellitus, Type 2; Dipeptidyl Peptidase 4; Female; Gastric Inhibitory Polypeptide; Gastrointestinal Hormones; Glucagon; Glucagon-Like Peptide 1; Humans; Insulin; Magnetic Resonance Imaging; Male; Meals; Middle Aged; Oxyntomodulin; Pancreatitis; Peptide YY; Postprandial Period; Prediabetic State; Subcutaneous Fat | 2019 |
SAD-A, a downstream mediator of GLP-1 signaling, promotes the phosphorylation of Bad S155 to regulate in vitro β-cell functions.
The incretin hormone GLP-1 reduces β-cell failure in patients with type 2 diabetes. Previous studies demonstrated that GLP-1 activates SAD-A, a member of the AMPK family, to regulate glucose-stimulated secretion (GSIS), but the underlying mechanisms of SAD-A regulation of β-cell functions remain poorly understood. Here, we propose that activation of SAD-A by GLP-1 promotes the phosphorylation of Bad S155, which in turn positively affects GSIS and β-cell survival. Bad therefore appears to be a downstream molecule of a SAD-A pathway that mediates the GLP-1-triggered reduction in β-cell failure. Knockdown of endogenous SAD-A expression significantly exacerbated in vitro β-cell dysfunction under lipotoxic conditions and promoted lipotoxicity-induced apoptosis, whereas overexpression of SAD-A inhibited β-cell apoptosis. SAD-A silencing increased ER stress and inhibited the autophagic flux, which contributed to β-cell apoptosis. Thus, SAD-A appears to function as a downstream molecule of GLP-1 signaling that results in Bad S155 phosphorylation. This phosphorylation might therefore be involved in the GLP-1-linked protection against β-cell dysfunction and apoptosis. Topics: Animals; Apoptosis; bcl-Associated Death Protein; Cell Line; Cells, Cultured; Diabetes Mellitus, Type 2; Glucagon-Like Peptide 1; Insulin-Secreting Cells; Mice; Palmitic Acid; Phosphorylation; Protein Serine-Threonine Kinases; Signal Transduction | 2019 |
Contribution of endogenous glucagon-like peptide-1 to changes in glucose metabolism and islet function in people with type 2 diabetes four weeks after Roux-en-Y gastric bypass (RYGB).
Glucagon-Like Peptide-1 (GLP-1) is an insulin secretagogue which is elevated after Roux-en-Y Gastric Bypass (RYGB). However, its contribution to glucose metabolism after RYGB remains uncertain.. We tested the hypothesis that GLP-1 lowers postprandial glucose concentrations and improves β-cell function after RYGB.. To address these questions we used a labeled mixed meal to assess glucose metabolism and islet function in 12 obese subjects with type 2 diabetes studied before and four weeks after RYGB. During the post-RYGB study subjects were randomly assigned to receive an infusion of either saline or Exendin-9,39 a competitive antagonist of GLP-1 at its receptor. Exendin-9,39 was infused at 300 pmol/kg/min for 6 h. All subjects underwent RYGB for medically-complicated obesity.. Exendin-9,39 resulted in increased integrated incremental postprandial glucose concentrations (181 ± 154 vs. 582 ± 129 mmol per 6 h, p = 0.02). In contrast, this was unchanged in the presence of saline (275 ± 88 vs. 315 ± 66 mmol per 6 h, p = 0.56) after RYGB. Exendin-9,39 also impaired β-cell responsivity to glucose but did not alter Disposition Index (DI).. These data indicate that the elevated GLP-1 concentrations that occur early after RYGB improve postprandial glucose tolerance by enhancing postprandial insulin secretion. Topics: Adult; Blood Glucose; Diabetes Mellitus, Type 2; Female; Gastric Bypass; Glucagon-Like Peptide 1; Humans; Insulin; Insulin-Secreting Cells; Islets of Langerhans; Male; Obesity; Postoperative Period; Postprandial Period | 2019 |
Possible role of GLP-1 in antidepressant effects of metformin and exercise in CUMS mice.
Both depression itself and antidepressant medication have been reported to be significantly related to the risk of type 2 diabetes mellitus (T2DM). Glucagon-like peptide-1 (GLP-1), a treatment target for T2DM, has a neuroprotective effect. As an enhancer and sensitiser of GLP-1, metformin has been reported to be safe for the neurodevelopment. The present study aimed to determine whether and how GLP-1 mediates antidepressant effects of metformin and exercise in mice.. Male C57BL/6 mice were exposed to chronic unpredictable mild stress (CUMS) for 8 weeks. From the 4th week, CUMS mice were subjected to oral metformin treatment and/or treadmill running. A videocomputerized tracking system was used to record behaviors of mice for a 5-min session. ELISA, western blotting and immunohistochemistry were used to examine serum protein concentrations, protein levels in whole hippocampus, protein distribution and expression in dorsal and ventral hippocampus, respectively.. Our results supported the validity of metformin as a useful antidepressant; moreover, treadmill running favored metformin effects on exploratory behaviors and serum corticosterone levels. CUMS reduced GLP-1 protein levels and phosphorylation levels of extracellular signal-regulated kinase 1/2 (ERK1/2), but increased protein levels of B-cell lymphoma 2-associated X-protein (BAX) in mice hippocampus. All these changes were restored by both single and combined treatment with metformin and exercise.. We did not establish a causal relationship between GLP-1 expression and related signaling, using GLP-1 agonist and antagonist or knockout techniques.. Our findings have demonstrated that protein levels of pERK and BAX may be relevant to the role of GLP-1 in antidepressant effects of metformin and exercise, which may provide a novel topic for future clinical research. Topics: Animals; Antidepressive Agents; bcl-2-Associated X Protein; Corticosterone; Depression; Depressive Disorder; Diabetes Mellitus, Type 2; Exercise Therapy; Exploratory Behavior; Glucagon-Like Peptide 1; Hippocampus; Hypoglycemic Agents; Male; MAP Kinase Signaling System; Metformin; Mice; Mice, Inbred C57BL; Neuroprotective Agents; Signal Transduction; Stress, Psychological | 2019 |
Comparison of Diabetes Remission and Micronutrient Deficiency in a Mildly Obese Diabetic Rat Model Undergoing SADI-S Versus RYGB.
Single-anastomosis duodeno-ileal bypass with sleeve gastrectomy (SADI-S) has launched a huge challenge to classic Roux-en-Y gastric bypass (RYGB). Our objective was to compare diabetes remission and micronutrient deficiency in a mildly obese diabetic rat model undergoing SADI-S versus RYGB.. Thirty adult male mildly obese diabetic rats were randomly assigned to sham (S), SADI-S, and RYGB groups. Body weight, food intake, fasting plasma glucose (FPG), oral glucose tolerance test (OGTT), plasma insulin, GLP-1, and ghrelin levels were measured at indicated time points. Meanwhile, insulin sensitivity and pancreatic β cell function were assessed during OGTT. Finally, plasma micronutrient evaluation and islet β cell mass analysis were performed after all animals were sacrificed.. As compared to sham, the SADI-S and RYGB groups achieved almost equivalent efficacy in caloric restriction and FPG control without excessive weight loss. During OGTT, the SADI-S and RYGB groups also provided comparable effects on glycemic excursion, insulin sensitivity, and β cell function; however, only rats in the RYGB group showed significant changes in gut hormones, whereas the three groups were found to exhibit no significant difference in β cell mass. In addition, only vitamin E in the RYGB group was deficient as compared with the SADI-S and S groups.. In mildly obese diabetic rat, SADI-S and RYGB procedures have comparable efficacy in diabetes remission and risk of micronutrient deficiency. These data show that each of the surgery accomplishes diabetes improvements through both overlapping and distinct mechanisms requiring further investigation. Topics: Anastomosis, Surgical; Animals; Bariatric Surgery; Blood Glucose; Diabetes Mellitus, Experimental; Diabetes Mellitus, Type 2; Duodenum; Eating; Gastrectomy; Gastric Bypass; Gastrointestinal Hormones; Glucagon-Like Peptide 1; Glucose Tolerance Test; Ileum; Insulin Resistance; Insulin-Secreting Cells; Male; Micronutrients; Obesity; Random Allocation; Rats; Rats, Wistar; Remission Induction; Weight Loss | 2019 |
PYY plays a key role in the resolution of diabetes following bariatric surgery in humans.
Bariatric surgery leads to early and long-lasting remission of type 2 diabetes (T2D). However, the mechanisms behind this phenomenon remain unclear. Among several factors, gut hormones are thought to be crucial mediators of this effect. Unlike GLP-1, the role of the hormone peptide tyrosine tyrosine (PYY) in bariatric surgery in humans has been limited to appetite regulation and its impact on pancreatic islet secretory function and glucose metabolism remains under-studied.. Changes in PYY concentrations were examined in obese patients after bariatric surgery and compared to healthy controls. Human pancreatic islet function was tested upon treatment with sera from patients before and after the surgery, in presence or absence of PYY. Alterations in intra-islet PYY release and insulin secretion were analysed after stimulation with short chain fatty acids (SCFAs), bile acids and the cytokine IL-22.. We demonstrate that PYY is a key effector of the early recovery of impaired glucose-mediated insulin and glucagon secretion in bariatric surgery. We establish that the short chain fatty acid propionate and bile acids, which are elevated after surgery, can trigger PYY release not only from enteroendocrine cells but also from human pancreatic islets. In addition, we identify IL-22 as a new factor which is modulated by bariatric surgery in humans and which directly regulates PYY expression and release.. This study shows that some major metabolic benefits of bariatric surgery can be emulated ex vivo. Our findings are expected to have a direct impact on the development of new non-surgical therapy for T2D correction. Topics: Animals; Bariatric Surgery; Biomarkers; Diabetes Mellitus, Type 2; Enteroendocrine Cells; Female; Gene Expression; Glucagon-Like Peptide 1; Humans; Interleukin-22; Interleukins; Islets of Langerhans; Male; Mice; Peptide YY; Rats | 2019 |
A Novel Dipeptidyl Peptidase IV Inhibitory Tea Peptide Improves Pancreatic β-Cell Function and Reduces α-Cell Proliferation in Streptozotocin-Induced Diabetic Mice.
Dipeptidyl peptidase IV (DPP-IV) inhibitors occupy a growing place in the drugs used for the management of type 2 diabetes. Recently, food components, including food-derived bioactive peptides, have been suggested as sources of DPP-IV inhibitors without side effects. Chinese black tea is a traditional health beverage, and it was used for finding DPP-IV inhibitory peptides in this study. The ultra-filtrated fractions isolated from the aqueous extracts of black tea revealed DPP-IV inhibitory activity in vitro. Four peptides under 1 kDa were identified by SDS-PAGE and LC-MS/MS (Liquid Chromatography-Mass Spectrometry-Mass Spectrometry) from the ultra-filtrate. The peptide II (sequence: AGFAGDDAPR), with a molecular mass of 976 Da, showed the greatest DPP-IV inhibitory activity (in vitro) among the four peptides. After administration of peptide II (400 mg/day) for 57 days to streptozotocin (STZ)-induced hyperglycemic mice, the concentration of glucagon-like peptide-1 (GLP-1) in the blood increased from 9.85 ± 1.96 pmol/L to 19.22 ± 6.79 pmol/L, and the insulin level was increased 4.3-fold compared to that in STZ control mice. Immunohistochemistry revealed the improved function of pancreatic beta-cells and suppressed proliferation of pancreatic alpha-cells. This study provides new insight into the use of black tea as a potential resource of food-derived DPP-IV inhibitory peptides for the management of type 2 diabetes. Topics: Animals; Cell Proliferation; Diabetes Mellitus, Experimental; Diabetes Mellitus, Type 2; Dipeptidyl Peptidase 4; Dipeptidyl-Peptidase IV Inhibitors; Glucagon-Like Peptide 1; Glucagon-Secreting Cells; Humans; Insulin-Secreting Cells; Mice; Tea | 2019 |
Duodenal-jejunal lining increases postprandial unconjugated bile acid responses and disrupts the bile acid-FXR-FGF19 axis in humans.
Placement of the duodenal-jejunal bypass liner (DJBL) leads to rapid weight loss and restoration of insulin sensitivity in a similar fashion to bariatric surgery. Increased systemic bile acid levels are candidate effectors for these effects through postprandial activation of their receptors TGR5 and FXR. We aimed to quantify postprandial bile acid, GLP-1 and FGF19 responses and assess their temporal relation to the weight loss and metabolic and hormonal changes seen after DJBL placement.. We performed mixed meal testing in 17 obese patients with type 2 diabetes mellitus (DM2) directly before, one week after and 6 months after DJBL placement.. Both fasting and postprandial bile acid levels were unchanged at 1 week after implantation, and greatly increased 6 months after implantation. The increase consisted of unconjugated bile acid species. 3 hour-postprandial GLP-1 levels increased after 1 week and were sustained, whereas FGF19 levels and postprandial plasma courses were unaffected.. DJBL placement leads to profound increases in unconjugated bile acid levels after 6 months, similar to the effects of bariatric surgery. The temporal dissociation between the changes in bile acids, GLP-1 and FGF19 and other gut hormone responses warrant caution about the beneficial role of bile acids after DJBL placement. This observational uncontrolled study emphasizes the need for future controlled studies. Topics: Bile Acids and Salts; Diabetes Mellitus, Type 2; Duodenum; Female; Fibroblast Growth Factors; Glucagon-Like Peptide 1; Humans; Jejunum; Male; Middle Aged; Postprandial Period; Weight Loss | 2019 |
Gastrointestinal motility in patients with end-stage renal disease on chronic hemodialysis.
Previous studies indicated delayed gastric emptying in patients with end-stage renal disease (ESRD) using indirect methods. The objective of the current study was to examine gastrointestinal motility using a direct method as well as the role of the incretin hormones and glucagon.. Patients on chronic hemodialysis and with either normal glucose tolerance, impaired glucose tolerance or type 2 diabetes, and healthy control subjects (N = 8, respectively) were studied. Gastric emptying time was measured by repeated gamma camera imaging for 6 hours after intake of a radioactive labeled standardized mixed solid and liquid meal. Glucagon, glucagon-like peptide-1 (GLP-1), and glucose-dependent insulinotropic polypeptide (GIP) levels were measured.. Patients were age, gender and BMI matched with controls. We found significantly higher gastric retention at 15 minutes, prolonged gastric mean emptying time, and gastric half-emptying time of the solid marker in all three groups of ESRD patients compared to controls. Significant differences in mean total area under the concentration curve (AUC) values across the four groups for GIP (P = 0.001), but not for GLP-1 and glucagon. The ESRD group had significant higher total AUC of GIP and glucagon compared to controls (P < 0.001 and P < 0.04) but not for GLP-1 (P = 0.4). No difference in incremental AUC was found.. We found altered gastrointestinal motility in dialysis patients, with higher gastric retention and prolonged gastric emptying, and higher total AUC of GIP and glucagon independent of the presence of diabetes or prediabetes. Topics: Aged; Blood Glucose; Diabetes Mellitus, Type 2; Female; Gastric Emptying; Gastric Inhibitory Polypeptide; Gastrointestinal Motility; Glucagon; Glucagon-Like Peptide 1; Glucose Intolerance; Humans; Kidney Failure, Chronic; Male; Middle Aged; Renal Dialysis | 2019 |
Discovery of a Natural-Product-Derived Preclinical Candidate for Once-Weekly Treatment of Type 2 Diabetes.
Poor medication adherence is one of the leading causes of suboptimal glycaemic control in approximately half of the patients with type 2 diabetes mellitus (T2DM). Long-acting antidiabetic drugs are clinically needed for improving patients' compliance. Dipeptidyl peptidase-4 (DPP-4) inhibitors play an increasingly important role in the treatment of T2DM because of their favorable properties of weight neutrality and hypoglycemia avoidance. Herein, we report the successful discovery and scale-up synthesis of compound 5, a structurally novel, potent, and long-acting DPP-4 inhibitor for the once-weekly treatment of T2DM. Inhibitor 5 has fast-associating and slow-dissociating binding kinetics profiles as well as slow clearance rate and long terminal half-life pharmacokinetic properties. A single-dose oral administration of 5 (3 mg/kg) inhibited >80% of DPP-4 activity for more than 7 days in diabetic mice. The long-term antidiabetic efficacies of 5 (10 mg/kg, qw) were better than those of the once-weekly trelagliptin and omarigliptin, especially in decreasing the hemoglobin A1c level. Topics: Animals; Biological Products; Blood Glucose; Diabetes Mellitus, Experimental; Diabetes Mellitus, Type 2; Dipeptidyl-Peptidase IV Inhibitors; Drug Administration Schedule; Glucagon-Like Peptide 1; Half-Life; Hypoglycemic Agents; Insulin; Mice; Mice, Inbred ICR; Rats; Rats, Sprague-Dawley | 2019 |
Lecithin nano-liposomal particle as a CRISPR/Cas9 complex delivery system for treating type 2 diabetes.
Protein-based Cas9 in vivo gene editing therapeutics have practical limitations owing to their instability and low efficacy. To overcome these obstacles and improve stability, we designed a nanocarrier primarily consisting of lecithin that can efficiently target liver disease and encapsulate complexes of Cas9 with a single-stranded guide RNA (sgRNA) ribonucleoprotein (Cas9-RNP) through polymer fusion self-assembly.. In this study, we optimized an sgRNA sequence specifically for dipeptidyl peptidase-4 gene (DPP-4) to modulate the function of glucagon-like peptide 1. We then injected our nanocarrier Cas9-RNP complexes directly into type 2 diabetes mellitus (T2DM) db/db mice, which disrupted the expression of DPP-4 gene in T2DM mice with remarkable efficacy. The decline in DPP-4 enzyme activity was also accompanied by normalized blood glucose levels, insulin response, and reduced liver and kidney damage. These outcomes were found to be similar to those of sitagliptin, the current chemical DPP-4 inhibition therapy drug which requires recurrent doses.. Our results demonstrate that a nano-liposomal carrier system with therapeutic Cas9-RNP has great potential as a platform to improve genomic editing therapies for human liver diseases. Topics: Animals; Blood Glucose; Cell Line; CRISPR-Cas Systems; Diabetes Mellitus, Type 2; Dipeptidyl Peptidase 4; Drug Delivery Systems; Gene Editing; Gene Targeting; Genetic Therapy; Glucagon-Like Peptide 1; Humans; Lecithins; Liposomes; Mice; Mice, Knockout; RNA, Guide, Kinetoplastida | 2019 |
Intestinal electrical stimulation attenuates hyperglycemia and prevents loss of pancreatic β cells in type 2 diabetic Goto-Kakizaki rats.
Recently, intestinal electrical stimulation (IES) has been reported to result in weight loss; however, it is unclear whether it has a therapeutic potential for diabetes. The aim of the present study was to explore the potential hypoglycemic effects of IES and its possible mechanisms involving β cells in diabetic rats.. Diabetic Goto-Kakizaki (GK) rats were chronically implanted with one pair of electrodes in the duodenum. The oral glucose tolerance test (OGTT) and insulin tolerance test (ITT) were performed with or without IES, and plasma glucagon-like peptide-1 (GLP-1) and insulin level were measured. In the other two OGTT sessions, rats were treated with either Exendin (9-39) (GLP-1 antagonist) or Exendin (9-39) plus IES to investigate the underlying mechanism involving GLP-1. Gastric emptying and small intestinal transit were also measured with or without IES. In a chronic study, GK rats were treated with IES or Sham-IES for 8 weeks. Blood glucose, plasma GLP-1 and insulin level, body weight, and food intake were measured. Pancreas weight, islet β-cell apoptosis, and proliferation were also analyzed.. Acute IES reduced blood glucose level from 60 to 120 min during OGTT by 16-20% (all p < 0.05, vs. Sham-IES). GLP-1 antagonist significantly blocked the inhibitory effect of IES on hyperglycemia from 15 to 120 min (all p < 0.05). IES accelerated the small intestinal transit by 15% (p = 0.004). After 8 weeks of chronic stimulation, IES significantly reduced blood glucose (p < 0.05) and body weight (p = 0.02) and increased the plasma GLP-1 concentration (p < 0.05). Furthermore, we observed that chronic IES reduced pancreatic β-cell apoptosis (p = 0.045), but showed no effects on β-cell proliferation.. Our study firstly proved the hypoglycemic effect of IES in a rodent model of type 2 diabetes, possibly attributed to the increasing GLP-1 secretion and improvement in β-cell functions. Topics: Animals; Blood Glucose; Body Weight; Diabetes Mellitus, Type 2; Eating; Electric Stimulation Therapy; Glucagon-Like Peptide 1; Glucose Tolerance Test; Hyperglycemia; Insulin; Insulin-Secreting Cells; Intestines; Male; Peptide Fragments; Rats | 2019 |
Comparison of Human and Murine Enteroendocrine Cells by Transcriptomic and Peptidomic Profiling.
Enteroendocrine cells (EECs) produce hormones such as glucagon-like peptide 1 and peptide YY that regulate food absorption, insulin secretion, and appetite. Based on the success of glucagon-like peptide 1-based therapies for type 2 diabetes and obesity, EECs are themselves the focus of drug discovery programs to enhance gut hormone secretion. The aim of this study was to identify the transcriptome and peptidome of human EECs and to provide a cross-species comparison between humans and mice. By RNA sequencing of human EECs purified by flow cytometry after cell fixation and staining, we present a first transcriptomic analysis of human EEC populations and demonstrate a strong correlation with murine counterparts. RNA sequencing was deep enough to enable identification of low-abundance transcripts such as G-protein-coupled receptors and ion channels, revealing expression in human EECs of G-protein-coupled receptors previously found to play roles in postprandial nutrient detection. With liquid chromatography-tandem mass spectrometry, we profiled the gradients of peptide hormones along the human and mouse gut, including their sequences and posttranslational modifications. The transcriptomic and peptidomic profiles of human and mouse EECs and cross-species comparison will be valuable tools for drug discovery programs and for understanding human metabolism and the endocrine impacts of bariatric surgery. Topics: Animals; Diabetes Mellitus, Type 2; Enteroendocrine Cells; Glucagon-Like Peptide 1; Humans; Mice; Receptors, G-Protein-Coupled; Transcriptome | 2019 |
Fractionated whole body gamma irradiation modulates the hepatic response in type II diabetes of high fat diet model rats.
HFD animals were exposed to a low rate of different fractionated whole body gamma irradiation doses (0.5, 1 and 2 Gy, three fractions per week for two consecutive months) and the expression of certain genes involved in type 2 diabetes mellitus (T2DM) in livers and brains of HFD Wistar rats was investigated. Additionally, levels of diabetes-related proteins encoded by the studied genes were analyzed. Results indicated that mRNA level of incretin glucagon like peptite-1 receptor (GLP-1R) was augmented in livers and brains exposed to 1 and 2 Gy doses. Moreover, the mitochondrial uncoupling proteins 2 and 3 (UCP2/3) expressions in animals fed on HFD compared to those fed on normal chow diet were significantly increased at all applied doses. GLP-1R and UCP3 protein levels were up regulated in livers. Total protein content increased at 0.5 and 1 Gy gamma irradiation exposure and returned to its normal level at 2 Gy dose. Results could be an indicator of type 2 diabetes delayed development during irradiation exposure and support the importance of GLP-1R as a target gene in radiotherapy against T2DM and its chronic complications. A new hypothesis of brain-liver and intestine interface is speculated by which an increase in the hepatic GLP-1R is influenced by the effect of fractionated whole body gamma irradiation. Topics: Animals; Brain; Diabetes Mellitus, Experimental; Diabetes Mellitus, Type 2; Diet, High-Fat; Disease Models, Animal; Gamma Rays; Glucagon-Like Peptide 1; Glucagon-Like Peptide-1 Receptor; Liver; Male; Rats; Rats, Wistar; Receptors, Glucagon; RNA, Messenger; Uncoupling Protein 2; Uncoupling Protein 3 | 2019 |
SGLT-2 inhibitors and GLP-1 receptor agonists for nephroprotection and cardioprotection in patients with diabetes mellitus and chronic kidney disease. A consensus statement by the EURECA-m and the DIABESITY working groups of the ERA-EDTA.
Chronic kidney disease (CKD) in patients with diabetes mellitus (DM) is a major problem of public health. Currently, many of these patients experience progression of cardiovascular and renal disease, even when receiving optimal treatment. In previous years, several new drug classes for the treatment of type 2 DM have emerged, including inhibitors of renal sodium-glucose co-transporter-2 (SGLT-2) and glucagon-like peptide-1 (GLP-1) receptor agonists. Apart from reducing glycaemia, these classes were reported to have other beneficial effects for the cardiovascular and renal systems, such as weight loss and blood pressure reduction. Most importantly, in contrast to all previous studies with anti-diabetic agents, a series of recent randomized, placebo-controlled outcome trials showed that SGLT-2 inhibitors and GLP-1 receptor agonists are able to reduce cardiovascular events and all-cause mortality, as well as progression of renal disease, in patients with type 2 DM. This document presents in detail the available evidence on the cardioprotective and nephroprotective effects of SGLT-2 inhibitors and GLP-1 analogues, analyses the potential mechanisms involved in these actions and discusses their place in the treatment of patients with CKD and DM. Topics: Blood Glucose; Diabetes Mellitus, Type 2; Disease Progression; Glucagon-Like Peptide 1; Glucagon-Like Peptide-1 Receptor; Heart Diseases; Humans; Hypoglycemic Agents; Kidney; Practice Guidelines as Topic; Randomized Controlled Trials as Topic; Renal Insufficiency, Chronic; Societies, Medical; Sodium-Glucose Transporter 2 Inhibitors; Weight Loss | 2019 |
The Effect of Gastric Bypass with a Distal Gastric Pouch on Glucose Tolerance and Diabetes Remission in Type 2 Diabetes Sprague-Dawley Rat Model.
Gastric bypass with a proximal gastric pouch (Roux-en-Y gastric bypass) induces early diabetes remission. The effect of gastric bypass with a distal gastric pouch remains unknown.. To observe the effect on glucose tolerance and diabetes remission of gastric bypass with a distal gastric pouch.. A type 2 diabetes (T2D) model was created in 44 Sprague-Dawley (SD) rats that randomly underwent Roux-en-Y gastric bypass (RYGB, n = 8); gastric bypass with duodenal-jejunal transit (GB-DJT, n = 8); distal-pouch gastric bypass with duodenal-jejunal transit (DPGB-DJT, n = 8); distal-pouch gastric bypass with duodenal-jejunal bypass (DPGB-DJB, n = 8); sham (n = 6); and Roux-en-Y gastric bypass with esophageal re-anastomosis (RYGB-Er, n = 6) surgery. In the DPGB-DJT and the DPGB-DJB groups, the gastric pouch was created in the distal stomach. In the RYGB and the GB-DJT groups, the gastric pouch was created in the proximal stomach. An oral glucose tolerance test (OGTT), insulin tolerance test (ITT) and mixed-meal tolerance test (MMTT) conducted preoperatively were repeated postoperatively.. GLP-1 AUC recorded preoperatively was significantly increased 8 weeks postoperatively in the RYGB, GB-DJT, and DPGB-DJB groups. Increased GLP-1 AUC in the DPGB-DJT did not reach statistical significance. Improved glucose tolerance in the RYGB and GB-DJT groups was significantly higher than DPGB-DJT group. DPGB-DJB did not improve glucose tolerance significantly. Gastrin level was increased significantly in the DPGB-DJT and DPGB-DJB groups.. In gastric bypass, creating the gastric pouch in the distal region of the stomach significantly impairs the glucose tolerance and diabetes remission in spite of the increased GLP-1 and insulin responses in T2D SD rat model, suggesting that bypassing the distal stomach may be the key mediator of early diabetes remission after RYGB. Topics: Analysis of Variance; Animals; Biomarkers; Blood Glucose; Diabetes Mellitus, Experimental; Diabetes Mellitus, Type 2; Gastric Bypass; Glucagon-Like Peptide 1; Glucose Tolerance Test; Insulin; Insulin Resistance; Male; Obesity, Morbid; Rats; Rats, Sprague-Dawley; Remission Induction | 2019 |
Construction of a dietary-cure
Topics: Animals; Blood Glucose; Diabetes Mellitus, Experimental; Diabetes Mellitus, Type 2; Disease Models, Animal; Gene Expression Regulation; Genetic Vectors; Glucagon-Like Peptide 1; Humans; Hypoglycemic Agents; Mice; Peptides; Saccharomyces cerevisiae; Tandem Repeat Sequences | 2019 |
Treatment with liraglutide, a glucagon-like peptide-1 analogue, improves effectively the skin lesions of psoriasis patients with type 2 diabetes: A prospective cohort study.
It has been reported that GLP-1 analogue can improve the skin lesions of psoriasis. However further research is needed to confirm that finding.. The study can provide further data regarding the efficacy and safety of GLP-1 analogue liraglutide in the treatment of psoriasis patients with type 2 diabetes.. We recruit 7 psoriasis patients with type 2 diabetes, and use hypodermic injection with liraglutide1.8 mg. In 12 weeks of treatment, we estimate the difference of before and after respectively, likeBMI, waist circumference, fasting blood glucose, fasting C-peptide, HbA1c, blood lipid levels, CRP, PASI, DLQI, skin tissue and pathological analysis of psoriasis.. GLP-1 analogueliraglutide can improve the skin lesions of psoriasis patients with type 2 diabetes effectively, especially for extremely severe psoriasis patients. Its therapeutic effect may be related to anti-inflammatory, hypoglycemic and reducing weight. Topics: Aged; Blood Glucose; Diabetes Mellitus, Type 2; Female; Glucagon-Like Peptide 1; Humans; Hypoglycemic Agents; Liraglutide; Male; Middle Aged; Prognosis; Prospective Studies; Psoriasis | 2019 |
GLP-1 and the renin-angiotensin-aldosterone system.
Topics: Angiotensin-Converting Enzyme Inhibitors; Diabetes Mellitus, Type 2; Glucagon-Like Peptide 1; Humans; Renin; Renin-Angiotensin System | 2019 |
How do these 3 diabetes agents compare in reducing mortality?
A meta-analysis reveals that there may be advantages associated with SGLT-2 inhibitors and GLP-1 agonists that are not associated with DPP-4 inhibitors. Topics: Diabetes Mellitus, Type 2; Dipeptidyl-Peptidase IV Inhibitors; Glucagon-Like Peptide 1; Glucose; Humans; Hypoglycemic Agents; Patients; Sodium | 2019 |
Bile Modulates Secretion of Incretins and Insulin: A Study of Human Extrahepatic Cholestasis.
Changes in bile flow after bariatric surgery may beneficially modulate secretion of insulin and incretins, leading to diabetes remission. However, the exact mechanism(s) involved is still unclear. Here, we propose an alternative method to investigate the relationship between alterations in physiological bile flow and insulin and incretin secretion by studying changes in gut-pancreatic function in extrahepatic cholestasis in nondiabetic humans.. To pursue this aim, 58 nondiabetic patients with recent diagnosis of periampullary tumors underwent an oral glucose tolerance test (OGTT), and a subgroup of 16 patients also underwent 4-hour mixed meal tests and hyperinsulinemic-euglycemic clamps.. The analysis of the entire cohort revealed a strong inverse correlation between total bilirubin levels and insulinogenic index. When subjects were divided on the basis of bilirubin levels, used as a marker of altered bile flow, subjects with high bilirubin levels displayed inferior glucose control and decreased insulin secretion during the OGTT. Altered bile flow elicited a markedly greater increase in glucagon and glucagon-like peptide 1 (GLP-1) secretion at fasting state, and following the meal, both glucagon and GLP-1 levels remained increased over time. Conversely, Glucose-dependent insulinotropic polypeptide (GIP) levels were comparable at the fasting state, whereas the increase following meal ingestion was significantly blunted with high bilirubin levels. We reveal strong correlations between total bilirubin and glucagon and GLP-1 levels.. Our findings suggest that acute extrahepatic cholestasis determines major impairment in enteroendocrine gut-pancreatic secretory function. The altered bile flow may determine a direct deleterious effect on β-cell function, perhaps mediated by the impairment of incretin hormone function. Topics: Ampulla of Vater; Bariatric Surgery; Bile; Bile Acids and Salts; Bilirubin; Blood Glucose; Cholestasis, Extrahepatic; Diabetes Mellitus, Type 2; Duodenal Neoplasms; Fasting; Female; Gastric Inhibitory Polypeptide; Glucagon; Glucagon-Like Peptide 1; Glucose Clamp Technique; Glucose Tolerance Test; Humans; Incretins; Insulin; Insulin Secretion; Male; Middle Aged; Pancreaticoduodenectomy; Postprandial Period | 2019 |
Does GLP-1 suppress hepatocyte glucose production directly, via fibroblast growth factor 21?
Topics: Animals; Diabetes Mellitus, Type 2; Fibroblast Growth Factors; Glucagon-Like Peptide 1; Glucose; Hepatocytes; Humans; Mice | 2019 |
Factors Related to Blood Intact Incretin Levels in Patients with Type 2 Diabetes Mellitus.
We performed this study to identify factors related to intact incretin levels in patients with type 2 diabetes mellitus (T2DM).. We cross-sectionally analyzed 336 patients with T2DM. Intact glucagon-like peptide 1 (iGLP-1) and intact glucose-dependent insulinotropic polypeptide (iGIP) levels were measured in a fasted state and 30 minutes after ingestion of a standard mixed meal. The differences between 30 and 0 minute iGLP-1 and iGIP levels were indicated as ΔiGLP-1 and ΔiGIP.. In simple correlation analyses, fasting iGLP-1 was positively correlated with glucose, C-peptide, creatinine, and triglyceride levels, and negatively correlated with estimated glomerular filtration rate. ΔiGLP-1 was positively correlated only with ΔC-peptide levels. Fasting iGIP showed positive correlations with glycosylated hemoglobin (HbA1c) and fasting glucose levels, and negative correlations with ΔC-peptide levels. ΔiGIP was negatively correlated with diabetes duration and HbA1c levels, and positively correlated with Δglucose and ΔC-peptide levels. In multivariate analyses adjusting for age, sex, and covariates, fasting iGLP-1 levels were significantly related to fasting glucose levels, ΔiGLP-1 levels were positively related to ΔC-peptide levels, fasting iGIP levels were related to fasting C-peptide levels, and ΔiGIP levels were positively related to ΔC-peptide and Δglucose levels.. Taken together, intact incretin levels are primarily related to C-peptide and glucose levels. This result suggests that glycemia and insulin secretion are the main factors associated with intact incretin levels in T2DM patients. Topics: Aged; Blood Glucose; C-Peptide; Creatinine; Cross-Sectional Studies; Diabetes Mellitus, Type 2; Eating; Fasting; Female; Gastric Inhibitory Polypeptide; Glucagon-Like Peptide 1; Humans; Incretins; Insulin Secretion; Male; Middle Aged; Multivariate Analysis; Triglycerides | 2019 |
Glucose-dependent Insulinotropic Polypeptide (GIP) Resistance and β-cell Dysfunction Contribute to Hyperglycaemia in Acromegaly.
Impaired insulin sensitivity (IS) and β-cell dysfunction result in hyperglycaemia in patients of acromegaly. However, alterations in incretins and their impact on glucose-insulin homeostasis in these patients still remain elusive. Twenty patients of active acromegaly (10 each, with and without diabetes) underwent hyperinsulinemic euglycaemic clamp and mixed meal test, before and after surgery, to measure indices of IS, β-cell function, GIP, GLP-1 and glucagon response. Immunohistochemistry (IHC) for GIP and GLP-1 was also done on intestinal biopsies of all acromegalics and healthy controls. Patients of acromegaly, irrespective of presence or absence of hyperglycaemia, had similar degree of insulin resistance, however patients with diabetes exhibited hyperglucagonemia, and compromised β-cell function despite significantly higher GIP levels. After surgery, indices of IS improved, GIP and glucagon levels decreased significantly in both the groups, while there was no significant change in indices of β-cell function in those with hyperglycaemia. IHC positivity for GIP, but not GLP-1, staining cells in duodenum and colon was significantly lower in acromegalics with diabetes as compared to healthy controls possibly because of high K-cell turnover. Chronic GH excess induces an equipoise insulin resistance in patients of acromegaly irrespective of their glycaemic status. Dysglycaemia in these patients is an outcome of β-cell dysfunction consequent to GIP resistance and hyperglucagonemia. Topics: Acromegaly; Adult; Blood Glucose; Case-Control Studies; Diabetes Mellitus, Type 2; Female; Gastric Inhibitory Polypeptide; Glucagon; Glucagon-Like Peptide 1; Glucose Clamp Technique; Humans; Hyperglycemia; Incretins; Insulin; Insulin Resistance; Insulin-Secreting Cells; Male; Prospective Studies; Receptors, Gastrointestinal Hormone | 2019 |
Hypoglycemic and Hypolipidemic Effects of Glucomannan Extracted from Konjac on Type 2 Diabetic Rats.
Diabetes and its complications are one of the most concerned metabolic diseases worldwide and threaten human health severely. Hypoglycemic and hypolipidemic effects of glucomannan extracted from konjac on high-fat diet and streptozocin-induced type 2 diabetic rats were evaluated in this study. Administration of konjac glucomannan significantly decreased the levels of fasting blood glucose, serum insulin, glucagon-like peptide 1, and glycated serum protein. The concentrations of serum lipids, including total cholesterol, triacylglycerols, low-density lipoprotein cholesterol, and non-esterified fatty acid, were notably reduced by konjac glucomannan treatment. In addition, antioxidant capacity, pancreatic injury, and adipose cell hypertrophy were ameliorated by konjac glucomannan administration in type 2 diabetic rats. Besides, ultra performance liquid chromatography-quadrupole time-of-flight mass spectrometry-based lipidomics analysis was used to explore the improvement of lipid metabolic by konjac glucomannan treatment. The disturbance of glycerolipid (diacylglycerol, monoacylglycerol, and triacylglycerol), fatty acyl (acylcarnitine and hydroxyl fatty acid), sphingolipid (ceramide and sphingomyelin), and glycerophospholipid (phosphatidylcholine) metabolism were attenuated by the glucomannan treatment. This study provided new insights for investigating the anti-diabetic effects of konjac glucomannan and suggests that konjac glucomannan may be a promising nutraceutical for treating type 2 diabetes. Topics: Amorphophallus; Animals; Blood Glucose; Diabetes Mellitus, Type 2; Diet, High-Fat; Fatty Acids, Nonesterified; Glucagon-Like Peptide 1; Humans; Hypoglycemic Agents; Hypolipidemic Agents; Insulin; Male; Mannans; Rats; Rats, Wistar | 2019 |
Authors' reply to "Comment on generalizability of GLP-1 RA CVOTs in US T2D population".
The authors of the manuscript "Generalizability of Glucagon-Like Peptide-1 Receptor Agonist Cardiovascular Outcome Trials Enrollment Criteria to the US Type 2 Diabetes Population" respond to a letter to the editor. Topics: Diabetes Mellitus, Type 2; Glucagon-Like Peptide 1; Glucagon-Like Peptide-1 Receptor; Humans | 2019 |
Comment on generalizability of GLP-1 RA CVOTs in US T2D population.
Previous research overstated the generalizability of the Exenatide Study of Cardiovascular Event Lowering trial results by omitting the restriction on the percentage of patients without a prior cardiovascular event. Topics: Cardiovascular Diseases; Diabetes Mellitus, Type 2; Glucagon-Like Peptide 1; Glucagon-Like Peptide-1 Receptor; Humans; Hypoglycemic Agents | 2019 |
[Incretins-adipocytokines interactions in type 2 diabetic subjects with or without non-alcoholic fatty liver disease: interest of GLP-1 (glucagon-like peptide-1) as a modulating biomarker].
Type 2 diabetes (T2DM) associated with non-alcoholic fatty liver disease (NAFLD) increases cardiovascular risk. Complex and subtle connections are established between hepatic dysfunction and adipose tissue hyperactivity. This relationship is mediated by insulin resistance, dyslipidemia and inflammation. Recently incretins have been involved in this connection including GLP-1 (glucagon-like peptide-1). The aim of this study is to establish interactions between the GLP-1 plasma levels and metabolic syndrome clusters and adipocytokines profile (leptin, adiponectin, resistin, TNFα and IL-6) in diabetic subjects with or without NAFLD. The study was undertaken on 320 adult subjects divided into four groups: NAFLD, DT2, NAFLD+DT2 and control. In all subjects, the metabolic syndrome clusters was investigated according to the NCEP/ATPIII criteria. Insulin resistance was evaluated by the Homa-IR model. The metabolic parameters were determined on Cobas® automated biochemical analysis. The adipocytokines are determined by immunoassay method on Elisa human reader - Biotek ELX 800. The NAFLD has been confirmed by abdominal ultrasound and by histology. Feeding and fasting plasma GLP-1 was assessed by Elisa method. The data revealed that insulin resistance (Homa-IR) is present in all groups. Homa-IR is negatively associated with plasma GLP-1 depletion in the NAFLD, DT2 and NAFLD+DT2 groups. Adiponectin levels are decreased in all groups as for GLP-1. At the opposite, leptin, resistin, TNFα and IL-6 levels show an inverse correlation with GLP-1. This study suggests that plasma GLP-1 can be considered as a transition and evolution biomarker between NAFLD and T2D. GLP-1 accurately reflects metabolic and inflammatory status, both in subjects with NAFLD only or with T2D only, before the diabetes - steatosis stage. Topics: Adipokines; Adult; Biomarkers; Case-Control Studies; Cross-Sectional Studies; Diabetes Mellitus, Type 2; Female; Glucagon-Like Peptide 1; Humans; Incretins; Insulin Resistance; Liver; Male; Metabolic Networks and Pathways; Metabolic Syndrome; Middle Aged; Non-alcoholic Fatty Liver Disease | 2019 |
Therapeutic Effects of Sleeve Gastrectomy and Ileal Transposition on Type 2 Diabetes in a Non-Obese Rat Model by Regulating Blood Glucose and Reducing Ghrelin Levels.
BACKGROUND Nowadays, more than 170 million patients suffer from diabetes mellitus worldwide. This study aimed to investigate the effects of sleeve gastrectomy (SG) and ileal transposition (IT) surgery on the control of diabetes. MATERIAL AND METHODS Goto-Kakizaki rats were used to establish type 2 diabetes models and undergo SG or IT surgery. At 2 months post-surgery, insulin, glucose, triglycerides (TG), total cholesterol (TC), glucose tolerance, glucagon-like peptide-1 (GLP-1) levels, and insulin sensitivity were evaluated. RESULTS SG significantly shortened operative time and post-operative recovery time compared to IT surgery (P<0.05). SG and IT surgery resulted in significantly induced weight loss, significantly decreased levels of glucose, and significantly enhanced levels of Ghrelin compared the Sham surgery group (P<0.001). SG and IT surgery resulted in significantly increased GLP-1 levels compared to Sham surgery (P<0.001). SG resulted in better reduction of oral glucose tolerance test (OGTT) glucose compared to IT surgery (P<0.05). SG and IT surgery significantly upregulated insulin tolerance test (ITT) levels compared to Sham surgery (P<0.001). SG induced better reductions in TC and TG compared to IT surgery (P<0.05). CONCLUSIONS In non-obese rats with spontaneous diabetes, both SG and IT surgery were found to control diabetes by regulating body weight and levels of glucose, Ghrelin, GLP-1, OGTT glucose, insulin, TC, and TG. Moreover, SG demonstrated advantages of shorter operative time, shorter post-operative recovery time, and better control of diabetes compared to IT surgery. Topics: Anastomosis, Surgical; Animals; Blood Glucose; Body Weight; Cholesterol; Diabetes Mellitus, Experimental; Diabetes Mellitus, Type 2; Disease Models, Animal; Gastrectomy; Ghrelin; Glucagon-Like Peptide 1; Glucose; Glucose Tolerance Test; Ileum; Insulin; Insulin Resistance; Male; Rats; Rats, Inbred Strains; Weight Loss | 2019 |
The Chinese herbal formulae (Yitangkang) exerts an antidiabetic effect through the regulation of substance metabolism and energy metabolism in type 2 diabetic rats.
Type 2 diabetes mellitus (T2DM) regarded as a "hot" disease in traditional Chinese medicine (TCM). Accordingly, TCM uses a cold drug or formula such as the Chinese herbal formulae "Yitangkang" (YTK) as a treatment. YTK exhibited a good clinical antidiabetic effect in several experiments. The correlation between the properties of a TCM drug or formula and its ability to regulate the substance metabolism, the energy metabolism and the endocrine system has been proven.. The present study aiming to evaluate the mechanism of antidiabetic action of YTK from the above perspective.. Three groups of streptozotocin (STZ)-diabetic rats have been treated with YTK at oral doses of 56 g/kg/d, 28 g/kg/d and 14 g/kg/d for 28 days using metformin as a reference drug. After treatment, several indices correlated with energy metabolism (superoxide dismutase, glutathione peroxidase, lactic dehydrogenase, adenotriphos, creatine phosphate kinase, AMPK, Na. Our findings showed that the formulae YTK could effectively regulate the levels of blood glucose, HbA1c, glucagon-like peptide-1, and significantly down-regulate the substance metabolism, energy metabolism and endocrine system indices of the diabetic rats.. These results were consistent with the TCM description of YTK as a "cold" treatment. It could provide an effective way to interpret the scientific connotation and comprehensive system of the Chinese herbal formulae. Topics: Animals; Blood Glucose; Cyclic AMP; Cyclic GMP; Diabetes Mellitus, Experimental; Diabetes Mellitus, Type 2; Drugs, Chinese Herbal; Energy Metabolism; Glucagon-Like Peptide 1; Glycated Hemoglobin; Hypoglycemic Agents; Liver; Male; Medicine, Chinese Traditional; Myocardium; Rats, Sprague-Dawley; Thyroid Hormones | 2019 |
Effects of boschnaloside from Boschniakia rossica on dysglycemia and islet dysfunction in severely diabetic mice through modulating the action of glucagon-like peptide-1.
Boschniakia rossica is a well-known traditional Chinese medicine for tonifying kidney and improving impotence. Boschnaloside is the major iridoid glycoside in this herb but therapeutic benefits for diabetes remained to be evaluated.. The current investigation aims to study the antidiabetic effect and the underlying pharmacological mechanisms.. Receptor binding, cAMP production, Ins secretion, glucagon-like peptide 1 (GLP-1) secretion, and dipeptidyl peptidase-4 activity assays were performed. Therapeutic benefits of orally administrated boschnaloside (150 and 300 mg/kg/day) were evaluated using severely 12-week old female diabetic db/db mice (Hemoglobin A1c >10%).. It appears that bochnaloside at oral dosage greater than 150 mg/kg/day exerts antidiabetic effects in vivo through modulating the action of GLP-1. Topics: Administration, Oral; Animals; Blood Glucose; Diabetes Mellitus, Experimental; Diabetes Mellitus, Type 2; Drugs, Chinese Herbal; Female; Glucagon-Like Peptide 1; Glucagon-Like Peptide-1 Receptor; Glucose Metabolism Disorders; Glycated Hemoglobin; Hypoglycemic Agents; Insulin; Insulin-Secreting Cells; Iridoids; Mice; Orobanchaceae; Plants, Medicinal; Rats | 2019 |
Antihyperglycemic effect of a chicken feet hydrolysate via the incretin system: DPP-IV-inhibitory activity and GLP-1 release stimulation.
Herein, the potential of hydrolysates of chicken feet proteins as natural dipeptidyl-peptidase IV (DPP-IV) inhibitors was investigated; moreover, three hydrolysates were selected due to their high DPP-IV inhibitory capacity (>80% inhibition), showing the IC50 values of around 300 μg estimated protein per mL; one of them (named p4H) was selected for the posterior analysis. In addition, its effect on glucose tolerance was investigated in two rat models (diet and age-induced) of glucose-intolerance and healthy animals; the amount of 300 mg estimated peptide per kg body weight improved the plasma glucose profile in both glucose-intolerance models. Moreover, it stimulated active GLP-1 release in the enteroendocrine STC-1 cells and rat ileum tissue. In conclusion, our results indicate that chicken feet proteins are a good source of bioactive peptides as DPP-IV inhibitors. Moreover, our results highlight the potential of the selected hydrolysate p4H in the management of type 2 diabetes due to its dual function of inhibition of the DPP-IV activity and induction of the GLP-1 release. Topics: Animals; Blood Glucose; Body Weight; Cell Line; Chickens; Diabetes Mellitus, Type 2; Diet; Dipeptidyl-Peptidase IV Inhibitors; Disease Models, Animal; Drug Delivery Systems; Female; Foot; Glucagon-Like Peptide 1; Glucose Intolerance; Hypoglycemic Agents; Incretins; Inhibitory Concentration 50; Male; Protein Hydrolysates; Rats; Rats, Wistar | 2019 |
[The effect of different types of bariatric surgery on the metabolic and hormonal parameters in rats with decompensed form of type 2 diabetes mellitus.]
Currently, one of the approaches to correct metabolic disorders in the type 2 diabetes mellitus (DM2) with obesity are bariatric surgery (BS), including sleeve gastrectomy (SG), gastric bypass (GB) and ileal transposition (IT). However, their effectiveness and impact on the hypothalamic signaling and hormonal status in severe forms of DM2 without obesity remain little studied. The aim of the work was to study the effect of IT, SG and GB on the insulin, leptin, ghrelin and glucagon-like peptide-1 (GLP-1) levels in the blood and on the expression of the genes encoding the main components of the hypothalamic signaling systems in rats with decompensated form of DM2, which was induced by a high-fat diet (3 months) and a single low dose of streptozotocin (25 mg/kg, 2 months after the start of the diet). In diabetic rats, a significantly expressed hyperglycemia, an impaired glucose tolerance, a decrease in glucose-stimulated GLP-1 level, a slight decrease in the insulin and leptin levels and an slight increase in ghrelin level were detected. In the hypothalamus, the expression of the genes encoding GLP-1 receptor, orexigenic agouti-related peptide (AgRP), as well as phosphotyrosine phosphatase 1B and SOCS3, the negative regulators of the leptin and insulin pathways was increased. In diabetic rats, the IT reduced the glucose levels 120 minutes after glucose load, increased the basal and glucose-stimulated GLP-1 levels, normalized the gene expression for phosphotyrosine phosphatase 1B, SOCS3, AgRP and GLP-1 receptor, which indicates the restoration of the hypothalamic signaling responsible for the control of energy metabolism and insulin sensitivity. In the case of SG and GB, an improvement in the glucose tolerance was found, and in the case of SG, an increase in the basal and glucose-stimulated GLP-1 levels was shown. However, no significant effect on the expression of the hypothalamic genes in SG and GB was found. Thus, IT is the most effective of all studied BS in the treatment of severe forms of DM2 without obesity.. В настоящее время одним из вариантов коррекции метаболических нарушений при сахарном диабете 2-го типа (СД2), который сопровождается ожирением, являются бариатрические операции, в том числе продольная резекция желудка (ПРЖ), гастрошунтирование (ГШ) и илеотранспозиция (ИТ). Однако их эффективность и влияние на гипоталамический сигналинг и гормональный статус при тяжелых формах СД2 без ожирения остаются малоизученными. Целью работы была оценка влияния ИТ, ПРЖ и ГШ на уровни инсулина, лептина, грелина и глюкагоноподобного пептида-1 (ГПП-1) в крови и на экспрессию генов, кодирующих ключевые компоненты гипоталамических сигнальных систем, у крыс с декомпенсированной формой СД2, которую вызывали высокожировой диетой (3 мес) и однократной низкой дозой стрептозотоцина (25 мг/кг, через 2 мес после начала диеты). У диабетических крыс отмечали сильно выраженную гипергликемию, нарушенную толерантность к глюкозе, снижение стимулированного глюкозой уровня ГПП-1, небольшое снижение содержания инсулина и лептина и повышение уровня грелина. В гипоталамусе была повышена экспрессия генов, кодирующих рецептор ГПП-1, орексигенный агутиподобный пептид (АПП), а также фосфотирозинфосфатазу 1B и SOCS3, негативные регуляторы лептинового и инсулинового путей. Проведение ИТ у диабетических крыс снижало уровень глюкозы через 120 мин после глюкозной нагрузки, повышало базальный и стимулированный глюкозой уровень ГПП-1, нормализовало экспрессию генов для фосфотирозинфосфатазы 1B, SOCS3, АПП и рецептора ГПП-1, что свидетельствует о восстановлении гипоталамической сигнализации, ответственной за контроль энергетического обмена и инсулиновой чувствительности. В случае ПРЖ и ГШ отмечали улучшение толерантности к глюкозе, а в случае ПРЖ также повышение базального и стимулированного глюкозой уровня ГПП-1, но заметного влияния на экспрессию гипоталамических генов выявлено не было. Таким образом, ИТ является наиболее эффективной из всех изученных бариатрических операций при лечении тяжелой формы СД2 без ожирения. Topics: Animals; Bariatric Surgery; Blood Glucose; Diabetes Mellitus, Experimental; Diabetes Mellitus, Type 2; Gastrectomy; Ghrelin; Glucagon-Like Peptide 1; Insulin; Leptin; Rats | 2019 |
An Electrochemical Sense Array Based on Aptamer and Biotin-Avidin System for the Selective Detection of Glucagon-Like Peptide-1.
GLP-1 as an incretin, has the ability to decrease blood sugar levels in a glucose-dependent manner by enhancing the secretion of insulin. Besides the insulinotropic effects, GLP-1 has been associated with numerous regulatory and protective effects. Thus, the action of GLP-1 is preserved in patients with type 2 diabetes and substantial pharmaceutical research has therefore been directed towards the development of GLP-1-based treatment.. In this work, we reported an electrochemical sense array based on the aptamer and biotin-avidin system for the detection of glucagon-like peptide-1 (GLP-1). The sense array employed a "stem-loop" conformation ap-tamer which was immobilized on the electrode of the 16-unit gold array via pre-labeled thiol group (-SH). Pre-labeled biotin serves as an affinity tag for the binding of avidin-horseradish peroxidase (avidin-HRP). The stem-loop structure of the aptamer kept the biotin from being approached by a bulky avidin-HRP by means of the steric hindrance. After the interaction of the target (GLP-1) and the aptamer, the aptamer would undergo a significant conformational change to force biotin away from the electrode, giving the avidin-HRP easy access to the labeled biotin. The HRP in the substrate could sensitively transduce the concentration of GLP-1 into the electrical signals, which were then measured by electrochemical technology of cyclic voltammetry and amperometric i-t curve.. Under the optimal experimental conditions, the proposed sense array for GLP-1 had a good linear relationship from 0.1 pmol/L to 20 pmol/L with a detection limit of 0.05 pmol/L and can be used to accurately detect the GLP-1 in serum.. The experimental results show that GLP-1 could be selectively detected by the electrochemical sense array, indicating that the proposed sense array based on the biotin-avidin system and the stem-loop aptamer has great potential in the detection of GLP-1. Topics: Aptamers, Nucleotide; Avidin; Biosensing Techniques; Biotin; Diabetes Mellitus, Type 2; Electrochemical Techniques; Glucagon-Like Peptide 1; Horseradish Peroxidase; Humans; Protein Binding; Reproducibility of Results | 2019 |
Effect of semaglutide on liver enzymes and markers of inflammation in subjects with type 2 diabetes and/or obesity.
Obesity and type 2 diabetes are drivers of non-alcoholic fatty liver disease (NAFLD). Glucagon-like peptide-1 analogues effectively treat obesity and type 2 diabetes and may offer potential for NAFLD treatment.. To evaluate the effect of the glucagon-like peptide-1 analogue, semaglutide, on alanine aminotransferase (ALT) and high-sensitivity C-reactive protein (hsCRP) in subjects at risk of NAFLD.. Data from a 104-week cardiovascular outcomes trial in type 2 diabetes (semaglutide 0.5 or 1.0 mg/week) and a 52-week weight management trial (semaglutide 0.05-0.4 mg/day) were analysed. Treatment ratios vs placebo were estimated for ALT (both trials) and hsCRP (weight management trial only) using a mixed model for repeated measurements, with or without adjustment for change in body weight.. Elevated baseline ALT (men >30 IU/L; women >19 IU/L) was present in 52% (499/957) of weight management trial subjects. In this group with elevated ALT, end-of-treatment ALT reductions were 6%-21% (P<0.05 for doses≥0.2 mg/day) and hsCRP reductions 25%-43% vs placebo (P < 0.05 for 0.2 and 0.4 mg/day). Normalisation of elevated baseline ALT occurred in 25%-46% of weight management trial subjects, vs 18% on placebo. Elevated baseline ALT was present in 41% (1325/3268) of cardiovascular outcomes trial subjects. In this group with elevated ALT, no significant ALT reduction was noted at end-of-treatment for 0.5 mg/week, while a 9% reduction vs placebo was seen for 1.0 mg/week (P = 0.0024). Treatment ratios for changes in ALT and hsCRP were not statistically significant after adjustment for weight change.. Semaglutide significantly reduced ALT and hsCRP in clinical trials in subjects with obesity and/or type 2 diabetes. Topics: Adolescent; Adult; Aged; Aged, 80 and over; Alanine Transaminase; Biomarkers; Body Weight; Cardiovascular Diseases; Clinical Trials, Phase II as Topic; Clinical Trials, Phase III as Topic; Diabetes Mellitus, Type 2; Double-Blind Method; Female; Glucagon-Like Peptide 1; Glucagon-Like Peptides; Humans; Hypoglycemic Agents; Inflammation; Liver; Male; Middle Aged; Multicenter Studies as Topic; Non-alcoholic Fatty Liver Disease; Obesity; Randomized Controlled Trials as Topic; Retrospective Studies; Weight Reduction Programs; Young Adult | 2019 |
Investigating Intestinal Glucagon After Roux-en-Y Gastric Bypass Surgery.
After Roux-en-Y gastric bypass (RYGB) surgery, postprandial plasma glucagon concentrations have been reported to increase. This occurs despite concomitant improved glucose tolerance and increased circulating plasma concentrations of insulin and the glucagon-inhibiting hormone glucagon-like peptide 1 (GLP-1).. To investigate whether RYGB-induced hyperglucagonemia may be derived from the gut.. Substudy of a prospective cross-sectional study at a university hospital in Copenhagen, Denmark.. Morbidly obese individuals undergoing RYGB (n = 8) with or without type 2 diabetes.. Three months before and after RYGB, participants underwent upper enteroscopy with retrieval of gastrointestinal mucosal biopsy specimens. Mixed-meal tests were performed 1 week and 3 months before and after RYGB.. The 29-amino acid glucagon concentrations in plasma and in mucosal gastrointestinal biopsy specimens were assessed using mass spectrometry-validated immunoassays, and a new monoclonal antibody reacting with immunoreactive glucagon was used for immunohistochemistry.. Postprandial plasma concentrations of glucagon after RYGB were increased. Expression of the glucagon gene in the small intestine increased after surgery. Glucagon was identified in the small-intestine biopsy specimens obtained after, but not before, RYGB. Immunohistochemically, mucosal biopsy specimens from the small intestine harbored cells costained for GLP-1 and immunoreactive glucagon.. Increased concentrations of glucagon were observed in small-intestine biopsy specimens and postprandially in plasma after RYGB. The small intestine harbored cells immunohistochemically costaining for GLP-1 and glucagon-like immunoreactivity after RYGB. Glucagon derived from small-intestine enteroendocrine l cells may contribute to postprandial plasma concentrations of glucagon after RYGB. Topics: Adolescent; Adult; Balloon Enteroscopy; Biomarkers; Blood Glucose; Case-Control Studies; Cross-Sectional Studies; Diabetes Mellitus, Type 2; Female; Follow-Up Studies; Gastric Bypass; Gastric Inhibitory Polypeptide; Glucagon; Glucagon-Like Peptide 1; Glycated Hemoglobin; Humans; Insulin; Intestines; Male; Meals; Middle Aged; Obesity, Morbid; Postprandial Period; Prognosis; Prospective Studies; Young Adult | 2019 |
Abcc5 Knockout Mice Have Lower Fat Mass and Increased Levels of Circulating GLP-1.
A previous genome-wide association study linked overexpression of an ATP-binding cassette transporter, ABCC5, in humans with a susceptibility to developing type 2 diabetes with age. Specifically, ABCC5 gene overexpression was shown to be strongly associated with increased visceral fat mass and reduced peripheral insulin sensitivity. Currently, the role of ABCC5 in diabetes and obesity is unknown. This study reports the metabolic phenotyping of a global Abcc5 knockout mouse.. Abcc5. ABCC5 protein expression levels are inversely related to fat mass and appear to play a role in the regulation of GLP-1 secretion from enteroendocrine cells. Topics: Adipose Tissue; Animals; Diabetes Mellitus, Type 2; Genome-Wide Association Study; Glucagon-Like Peptide 1; Glucose Tolerance Test; Homeostasis; Insulin; Insulin Resistance; Male; Mice; Mice, Knockout; Multidrug Resistance-Associated Proteins | 2019 |
Relationships between Body Composition and Plasma Levels of Pancreatic, Gut, and Adipose Tissue Hormones in db/db Mice, a Model of Type 2 Diabetes Mellitus.
Topics: Adipose Tissue; Animals; Body Composition; Diabetes Mellitus, Type 2; Gastrointestinal Hormones; Ghrelin; Glucagon; Glucagon-Like Peptide 1; Glucose; Insulin; Leptin; Male; Mice; Mice, Inbred NOD; Pancreatic Hormones; Plasminogen Activators; Resistin | 2019 |
Surface Coating Approach to Overcome Mucosal Entrapment of DNA Nanoparticles for Oral Gene Delivery of Glucagon-like Peptide 1.
Topics: A549 Cells; Animals; Blood Glucose; Diabetes Mellitus, Type 2; DNA; Drug Carriers; Glucagon-Like Peptide 1; HEK293 Cells; HeLa Cells; Hep G2 Cells; Humans; Immunohistochemistry; Insulin; Liver; Lung; Mice; Nanoparticles; Polyethylene Glycols | 2019 |
Brain GLP-1/IGF-1 Signaling and Autophagy Mediate Exendin-4 Protection Against Apoptosis in Type 2 Diabetic Rats.
Type 2 diabetes (T2D) is a modern socioeconomic burden, mostly due to its long-term complications affecting nearly all tissues. One of them is the brain, whose dysfunctional intracellular quality control mechanisms (namely autophagy) may upregulate apoptosis, leading to cognitive dysfunction and Alzheimer disease (AD). Since impaired brain insulin signaling may constitute the crosslink between T2D and AD, its restoration may be potentially therapeutic herein. Accordingly, the insulinotropic anti-T2D drugs from glucagon-like peptide-1 (GLP-1) mimetics, namely, exendin-4 (Ex-4), could be a promising therapy. In line with this, we hypothesized that peripherally administered Ex-4 rescues brain intracellular signaling pathways, promoting autophagy and ultimately protecting against chronic T2D-induced apoptosis. Thus, we aimed to explore the effects of chronic, continuous, subcutaneous (s.c.) exposure to Ex-4 in brain cortical GLP-1/insulin/insulin-like growth factor-1 (IGF-1) signaling, and in autophagic and cell death mechanisms in middle-aged (8 months old), male T2D Goto-Kakizaki (GK) rats. We used brain cortical homogenates obtained from middle-aged (8 months old) male Wistar (control) and T2D GK rats. Ex-4 was continuously administered for 28 days, via s.c. implanted micro-osmotic pumps (5 μg/kg/day; infusion rate 2.5 μL/h). Peripheral characterization of the animal models was given by the standard biochemical analyses of blood or plasma, the intraperitoneal glucose tolerance test, and the heart rate. GLP-1, insulin, and IGF-1, their downstream signaling and autophagic markers were evaluated by specific ELISA kits and Western blotting. Caspase-like activities and other apoptotic markers were given by colorimetric methods and Western blotting. Chronic Ex-4 treatment attenuated peripheral features of T2D in GK rats, including hyperglycemia and insulin resistance. Furthermore, s.c. Ex-4 enhanced their brain cortical GLP-1 and IGF-1 levels, and subsequent signaling pathways. Specifically, Ex-4 stimulated protein kinase A (PKA) and phosphoinositide 3-kinase (PI3K)/Akt signaling, increasing cGMP and AMPK levels, and decreasing GSK3β and JNK activation in T2D rat brains. Moreover, Ex-4 regulated several markers for autophagy in GK rat brains (as mTOR, PI3K class III, LC3 II, Atg7, p62, LAMP-1, and Parkin), ultimately protecting against apoptosis (by decreasing several caspase-like activities and mitochondrial cytochrome c, and increasing Bcl2 levels upon T2D). A Topics: Animals; Apoptosis; Autophagy; Brain; Diabetes Mellitus, Experimental; Diabetes Mellitus, Type 2; Exenatide; Glucagon-Like Peptide 1; Insulin-Like Growth Factor I; Male; Models, Biological; Rats, Wistar; Signal Transduction | 2018 |
Real-world comparison of treatment patterns and effectiveness of albiglutide and liraglutide.
To compare medication adherence, discontinuation and glycemic control in patients receiving albiglutide versus liraglutide.. Administrative claims data and glycated hemoglobin (HbA. Patients were matched 1:1 in the albiglutide (n = 2213) and liraglutide (n = 2213) overall cohorts and in 244 patients with HbA. Similar treatment patterns and clinically meaningful reductions in HbA Topics: Blood Glucose; Diabetes Mellitus, Type 2; Female; Glucagon-Like Peptide 1; Glycated Hemoglobin; Humans; Hypoglycemic Agents; Liraglutide; Male; Medication Adherence; Middle Aged; Retrospective Studies; Treatment Outcome | 2018 |
Rebirth of the Incretin Concept: Its conception and early development.
This paper describes the resurrection of the Incretin Concept in the early 1960s. It began with the more or less simultaneous discovery by three groups working independently in London. Dupre demonstrated that secretin given intravenously with glucose increased its rate of disappearance from the blood, McIntyre and co-workers established that hyperglycaemia evoked by oral glucose stimulated more insulin secretion than comparable hyperglycaemia produced by intravenous glucose and Marks and Samols established the insulinotropic properties of glucagon. The concept evolved with the discovery by Samols and co-workers that oral glucose stimulated the release of immunoreactive glucagon-like substances from the gut mucosa and the subsequent isolation of glucagon immunoreactive compounds, most notably oxyntomodulin and glicentin, and of gastic inhibitory polypetide (GIP). It concluded with the isolation and characterisation of glucagon-like peptide 1 (7-36) amide. Topics: Blood Glucose; Diabetes Mellitus, Type 2; Gastric Inhibitory Polypeptide; Glucagon; Glucagon-Like Peptide 1; Glucose; Humans; Hyperglycemia; Incretins; Insulin; Peptide Fragments | 2018 |
Comparative effectiveness of once-weekly glucagon-like peptide-1 receptor agonists with regard to 6-month glycaemic control and weight outcomes in patients with type 2 diabetes.
A retrospective cohort study was conducted in patients with type 2 diabetes in an electronic medical record database to compare real-world, 6-month glycated haemoglobin (HbA1c) and weight outcomes for exenatide once weekly with those for dulaglutide and albiglutide. The study included 2465 patients: exenatide once weekly, n = 2133; dulaglutide, n = 201; and albiglutide, n = 131. The overall mean (standard deviation [s.d.]) age was 60 (11) years and 54% were men; neither differed among the comparison groups. The mean (s.d.) baseline HbA1c was similar in the exenatide once-weekly (8.3 [1.7]%) and dulaglutide groups (8.5 [1.5]%; P = .165), but higher in the albiglutide group (8.7 [1.7]%; P < .001). The overall mean (s.d.) HbA1c change was -0.5 (1.5)% (P < .001) and this did not differ among the comparison groups in either adjusted or unadjusted analyses. The mean (s.d.) weight change was -1.4 (4.7) kg for exenatide once weekly and -1.6 (3.7) kg for albiglutide (P = .579), but was greater for dulaglutide, at -2.7 (5.7) kg (P = .001). Outcomes were similar in subsets of insulin-naive patients with baseline HbA1c ≥7.0% or ≥9.0%. All agents significantly reduced HbA1c at 6 months, with no significant differences among agents or according to baseline HbA1c in insulin-naive subgroups. Topics: Adult; Aged; Body Mass Index; Cohort Studies; Diabetes Mellitus, Type 2; Drug Administration Schedule; Exenatide; Female; Follow-Up Studies; Glucagon-Like Peptide 1; Glucagon-Like Peptide-1 Receptor; Glucagon-Like Peptides; Glycated Hemoglobin; Humans; Hyperglycemia; Hypoglycemia; Hypoglycemic Agents; Immunoglobulin Fc Fragments; Male; Middle Aged; Obesity; Recombinant Fusion Proteins; Retrospective Studies; Weight Loss | 2018 |
Sitagliptin and Roux-en-Y gastric bypass modulate insulin secretion via regulation of intra-islet PYY.
The gut hormone peptide tyrosine tyrosine (PYY) is critical for maintaining islet integrity and restoring islet function following Roux-en-Y gastric bypass (RYGB). The expression of PYY and its receptors (NPYRs) in islets has been documented but not fully characterized. Modulation of islet PYY by the proteolytic enzyme dipeptidyl peptidase IV (DPP-IV) has not been investigated and the impact of DPP-IV inhibition on islet PYY function remains unexplored. Here we have addressed these gaps and their effects on glucose-stimulated insulin secretion (GSIS). We have also investigated changes in pancreatic PYY in diabetes and following RYGB.. Immunohistochemistry and gene expression analysis were used to assess PYY, NPYRs and DPP-IV expression in rodent and human islets. DPP-IV activity inhibition was achieved by sitagliptin. Secretion studies were used to test PYY and the effects of sitagliptin on insulin release, and the involvement of GLP-1. Radioimmunoassays were used to measure hormone content in islets.. PYY and DPP-IV localized in different cell types in islets while NPYR expression was confined to the beta-cells. Chronic PYY application enhanced GSIS in rodent and diabetic human islets. DPP-IV inhibition by sitagliptin potentiated GSIS; this was mediated by locally-produced PYY, and not GLP-1. Pancreatic PYY was markedly reduced in diabetes. RYGB strongly increased islet PYY content, but did not lead to full restoration of pancreatic GLP-1 levels.. Local regulation of pancreatic PYY, rather than GLP-1, by DPP-IV inhibition or RYGB can directly modulate the insulin secretory response to glucose, indicating a novel role of pancreatic PYY in diabetes and weight-loss surgery. Topics: Animals; Diabetes Mellitus, Type 2; Dipeptides; Dipeptidyl Peptidase 4; Dipeptidyl-Peptidase IV Inhibitors; Dose-Response Relationship, Drug; Female; Gastric Bypass; Glucagon-Like Peptide 1; Humans; Hypoglycemic Agents; Insulin Secretion; Insulin-Secreting Cells; Male; Mice; Rats, Wistar; Receptors, Neuropeptide Y; Sitagliptin Phosphate | 2018 |
Metabolite ratios as potential biomarkers for type 2 diabetes: a DIRECT study.
Circulating metabolites have been shown to reflect metabolic changes during the development of type 2 diabetes. In this study we examined the association of metabolite levels and pairwise metabolite ratios with insulin responses after glucose, glucagon-like peptide-1 (GLP-1) and arginine stimulation. We then investigated if the identified metabolite ratios were associated with measures of OGTT-derived beta cell function and with prevalent and incident type 2 diabetes.. We measured the levels of 188 metabolites in plasma samples from 130 healthy members of twin families (from the Netherlands Twin Register) at five time points during a modified 3 h hyperglycaemic clamp with glucose, GLP-1 and arginine stimulation. We validated our results in cohorts with OGTT data (n = 340) and epidemiological case-control studies of prevalent (n = 4925) and incident (n = 4277) diabetes. The data were analysed using regression models with adjustment for potential confounders.. There were dynamic changes in metabolite levels in response to the different secretagogues. Furthermore, several fasting pairwise metabolite ratios were associated with one or multiple clamp-derived measures of insulin secretion (all p < 9.2 × 10. In this study we have shown that the Val_PC ae C32:2 metabolite ratio is associated with an increased risk of type 2 diabetes and measures of insulin secretion and resistance. The observed effects were stronger than that of the individual metabolites and independent of known risk factors. Topics: Arginine; Biomarkers; Blood Glucose; Diabetes Mellitus, Type 2; Female; Glucagon-Like Peptide 1; Glucose; Glucose Tolerance Test; Humans; Insulin; Male; Risk Factors | 2018 |
The role of whey protein in postprandial glycaemic control.
Epidemiological studies demonstrate that poor glycaemic control is an independent risk factor for CVD. Postprandial glycaemia has been demonstrated as a better predictor of glycated Hb, the gold standard of glycaemic control, when compared with fasting blood glucose. There is a need for more refined strategies to tightly control postprandial glycaemia, particularly in those with type 2 diabetes, and nutritional strategies around meal consumption may be effective in enhancing subsequent glycaemic control. Whey protein administration around meal times has been demonstrated to reduce postprandial glycaemia, mediated through various mechanisms including an enhancement of insulin secretion. Whey protein ingestion has also been shown to elicit an incretin effect, enhancing the secretion of glucose-dependent insulinotropic peptide and glucagon-like peptide-1, which may also influence appetite regulation. Acute intervention studies have shown some promising results however many have used large dosages (50-55 g) of whey protein alongside high-glycaemic index test meals, such as instant powdered potato mixed with glucose, which does not reflect realistic dietary strategies. Long-term intervention studies using realistic strategies around timing, format and amount of whey protein in relevant population groups are required. Topics: Blood Glucose; Diabetes Mellitus, Type 2; Gastric Inhibitory Polypeptide; Glucagon-Like Peptide 1; Glycated Hemoglobin; Glycemic Index; Humans; Incretins; Insulin Secretion; Meals; Postprandial Period; Whey Proteins | 2018 |
Enteroendocrine K and L cells in healthy and type 2 diabetic individuals.
Enteroendocrine K and L cells are pivotal in regulating appetite and glucose homeostasis. Knowledge of their distribution in humans is sparse and it is unknown whether alterations occur in type 2 diabetes. We aimed to evaluate the distribution of enteroendocrine K and L cells and relevant prohormone-processing enzymes (using immunohistochemical staining), and to evaluate the mRNA expression of the corresponding genes along the entire intestinal tract in individuals with type 2 diabetes and healthy participants.. In this cross-sectional study, 12 individuals with type 2 diabetes and 12 age- and BMI-matched healthy individuals underwent upper and lower double-balloon enteroscopy with mucosal biopsy retrieval from approximately every 30 cm of the small intestine and from seven specific anatomical locations in the large intestine.. Significantly different densities for cells positive for chromogranin A (CgA), glucagon-like peptide-1, glucose-dependent insulinotropic polypeptide, peptide YY, prohormone convertase (PC) 1/3 and PC2 were observed along the intestinal tract. The expression of CHGA did not vary along the intestinal tract, but the mRNA expression of GCG, GIP, PYY, PCSK1 and PCSK2 differed along the intestinal tract. Lower counts of CgA-positive and PC1/3-positive cells, respectively, were observed in the small intestine of individuals with type 2 diabetes compared with healthy participants. In individuals with type 2 diabetes compared with healthy participants, the expression of GCG and PYY was greater in the colon, while the expression of GIP and PCSK1 was greater in the small intestine and colon, and the expression of PCSK2 was greater in the small intestine.. Our findings provide a detailed description of the distribution of enteroendocrine K and L cells and the expression of their products in the human intestinal tract and demonstrate significant differences between individuals with type 2 diabetes and healthy participants.. NCT03044860. Topics: Adult; Aged; Chromogranin A; Cross-Sectional Studies; Diabetes Mellitus, Type 2; Enteroendocrine Cells; Female; Gastric Inhibitory Polypeptide; Gastrointestinal Tract; Glucagon-Like Peptide 1; Humans; Immunohistochemistry; Male; Middle Aged; Peptide YY; Proprotein Convertase 1; Proprotein Convertase 2; Proprotein Convertases | 2018 |
Protective effects of dietary polyphenols from black soybean seed coats on islet and renal function in streptozotocin-induced diabetic rats.
The aim of this study was to investigate the antidiabetic effects of the crude polyphenol extract (BSCP) from black soybean seed coats (BSC) and the whole flour of BSC and illustrate the mechanism in terms of islet and renal protection.. BSCP and BSC effectively controlled the increased blood glucose level and impaired glucose tolerance in streptozotocin (STZ)-induced diabetic rats after 8 weeks of treatment. They increased the concentrations of serum insulin, C-peptide and Glp-1 (P < 0.05) by improving the STZ-induced damage of islet β-cells and increasing their insulin expression (P < 0.05). Lipid profiles and antioxidant activities were also improved. Moreover, BSCP and BSC tended to decrease serum creatinine (0.05 < P < 0.1), and blood urea nitrogen was decreased by BSC significantly (P < 0.05). They also led to significantly lower glomerular volume (P < 0.05).. Long-term intervention with BSC at a low dose of polyphenols plays a role in controlling blood glucose and lipids levels by promoting insulin secretion and restoring islet β-cell function, the same as BSCP. These benefits are accompanied by their potential protection of diabetic renal dysfunction. BSCP is mainly responsible for the antidiabetic effect of BSC. © 2017 Society of Chemical Industry. Topics: Animals; Blood Glucose; Diabetes Mellitus, Type 2; Glucagon-Like Peptide 1; Glycine max; Humans; Hypoglycemic Agents; Insulin; Insulin Secretion; Islets of Langerhans; Kidney; Male; Oxidative Stress; Phytotherapy; Plant Extracts; Polyphenols; Rats; Rats, Sprague-Dawley; Rats, Wistar; Seeds; Streptozocin | 2018 |
Postmeal increment in intact glucagon-like peptide 1 level, but not intact glucose-dependent insulinotropic polypeptide levels, is inversely associated with metabolic syndrome in patients with type 2 diabetes.
Metabolic syndrome increases the risk of cardiovascular disease. Recently glucagon-like peptide 1 (GLP-1) agonists proved to be effective in preventing cardiovascular disease (CVD) in patients with type 2 diabetes. We investigated the association of blood incretin levels with metabolic syndrome in patients with type 2 diabetes.. This is a cross-sectional study involving 334 people with type 2 diabetes. Intact GLP-1 (iGLP-1) and intact glucose-dependent insulinotropic polypeptide (iGIP) levels were measured in a fasted state and 30 min after ingestion of a standard mixed meal. Metabolic syndrome was diagnosed based on the criteria of the International Diabetes Federation.. Two hundred twenty-five (69%) of the subjects have metabolic syndrome. The fasting iGLP-1 level was no different between groups. Thirty-min postprandial iGLP-1 was non-significantly lower in the subjects who had metabolic syndrome. Incremental iGLP-1 (ΔiGLP-1, the difference between 30-min postmeal and fasting iGLP-1 levels) was significantly lower in those with metabolic syndrome. There were no significant differences in fasting iGIP, postprandial iGIP, and ΔiGIP between groups. The ΔiGLP-1, but not ΔiGIP levels decreased significantly as the number of metabolic syndrome components increased. In hierarchical logistic regression analysis, the ΔiGLP-1 level was found to be a significant contributor to metabolic syndrome even after adjusting for other covariates.. Taken together, the iGLP-1 increment in the 30 min after meal ingestion is inversely associated with metabolic syndrome in patients with type 2 diabetes. This suggests that postmeal iGLP-1 increment could be useful in assessing cardiovascular risk in type 2 diabetes. Topics: Aged; Cardiovascular Diseases; Cross-Sectional Studies; Diabetes Mellitus, Type 2; Female; Gastric Inhibitory Polypeptide; Glucagon-Like Peptide 1; Humans; Incretins; Male; Metabolic Syndrome; Middle Aged; Postprandial Period; Risk | 2018 |
Deactivation of the NLRP3 inflammasome in infiltrating macrophages by duodenal-jejunal bypass surgery mediates improvement of beta cell function in type 2 diabetes.
Bariatric surgery could improve pancreatic beta cell function, thereby leading to the remission of the type 2 diabetes mellitus (T2DM). However, the specific mechanism underlying this phenomenon is yet to be revealed. The aim of this study is to test the hypothesis that Nod-like receptor family pyrin domain containing 3 (NLRP3) inflammasome in infiltrating macrophages plays an important role in the modulation of beta cell function after duodenal-jejunal bypass (DJB) surgery.. DJB and sham surgery were performed in diabetic Sprague-Dawley (SD) rats induced by high-fat diet (HFD) and streptozotocin (STZ). Body weight, food intake, and glucose tolerance test (GTT) were measured at indicated time points. Apoptosis of the beta cells was measured by Terminal deoxynucleotidyl transferase mediated dUTP Nick End Labeling (TUNEL) assay. We also assessed the macrophage content and NLRP3 expression in the rat model. Furthermore, macrophage reconstitution was performed after DJB surgery. Beta cell function and NLRP3 inflammasome pathway were re-evaluated in wild-type macrophage reconstitution group and NLRP3-knockdown macrophage reconstitution group.. DJB surgery group rats displayed rapid and sustained improvement in glucose tolerance. Decreased apoptosis and improved secretion function of the beta cells were observed in DJB surgery group. NLRP3 inflammasome pathway in infiltrating macrophages was also suppressed after DJB surgery. Moreover, diabetic remission acquired by DJB sustained in NLRP3-knockdown macrophage reconstitution group, while extinguished in group reconstituted with wild-type macrophage.. NLRP3 inflammasome deactivation in infiltrating macrophages is involved in marked beta cell function improvement after DJB surgery. Topics: Animals; Bariatric Surgery; Diabetes Mellitus, Experimental; Diabetes Mellitus, Type 2; Diet, High-Fat; Glucagon-Like Peptide 1; Insulin-Secreting Cells; Macrophages; Male; NLR Family, Pyrin Domain-Containing 3 Protein; Rats; Rats, Sprague-Dawley; Streptozocin | 2018 |
Impaired secretion of active GLP-1 in patients with hypertriglyceridaemia: A novel lipotoxicity paradigm?
Lipotoxicity plays an important role in the pathogenesis of β-cell dysfunction. Glucagon-like peptide-1 (GLP-1) is an incretin hormone that exerts beneficial effects on the number and function of islet β cells. However, the effect of lipotoxicity on GLP-1 secretion is still unknown.. Twenty-five patients who were newly diagnosed with diabetes were recruited from 400 subjects based on 75-g Oral Glucose Tolerance Test. Patients were divided into diabetes (DM) and DM combined with hypertriglyceridaemia (DM + HTG) groups according to their serum triglyceride (TG) levels. Seventy-one normal controls and 17 patients with isolated hypertriglyceridaemia were matched by age and gender.. Total and active fasting GLP-1 and 2-hour GLP-1 levels were not significantly altered among the 4 groups. However, total and active ΔGLP-1 levels (the difference between 2-hour GLP-1 and fasting GLP-1 levels) were significantly reduced in the isolated HTG, DM, and DM + HTG groups, particularly the DM + HTG group. The ratio of serum active GLP-1 (AGLP-1) to total GLP-1 (TGLP-1) levels was also decreased in patients with isolated HTG, suggesting that active GLP-1 secretion may be more seriously impaired. Both ΔTGLP-1 and ΔAGLP-1 levels were negatively correlated with serum TG levels, body mass index and fasting plasma glucose (FPG) levels and positively correlated with HDL-C levels. According to the multivariate linear regression analysis, only TG and FPG levels were independently associated with ΔTGLP-1 and ΔAGLP-1 levels.. Impaired GLP-1 secretion was associated with hypertriglyceridaemia and diabetes, and a more obvious association was noted in hypertriglyceridaemic patients with diabetes. Topics: Adolescent; Adult; Aged; Biomarkers; Blood Glucose; Body Mass Index; Case-Control Studies; China; Diabetes Mellitus, Type 2; Female; Follow-Up Studies; Glucagon-Like Peptide 1; Glucose Tolerance Test; Humans; Hypertriglyceridemia; Incidence; Male; Middle Aged; Prognosis; Young Adult | 2018 |
The GLP-1 response to glucose does not mediate beta and alpha cell dysfunction in Hispanics with abnormal glucose metabolism.
Glucagon-like peptide-1 (GLP-1) contributes to insulin secretion after meals. Though Hispanics have increased risk for type 2 diabetes mellitus, it is unknown if impaired GLP-1 secretion contributes to this risk. We therefore studied plasma GLP-1 secretion and action in Hispanic adults.. Hispanic (H; n = 31) and non-Hispanic (nH; n = 15) participants underwent an oral glucose tolerance test (OGTT). All participants were categorized by glucose tolerance into four groups: normal glucose tolerant non-Hispanic (NGT-nH; n = 15), normal glucose tolerant Hispanic (NGT-H; n = 12), impaired glucose tolerant Hispanic (IGT-H; n = 11), or newly diagnosed type 2 diabetes mellitus, Hispanic (T2D-H; n = 8).. Glucose-induced increments in plasma GLP-1 (Δ-GLP-1) were not different in NGT-H and NGT-nH (p = .38), nor amongst Hispanic subgroups with varying degrees of glucose homeostasis (p = .6). In contrast, the insulinogenic index in T2D-H group was lower than the other groups (p = .016). Subjects with abnormal glucose homeostasis (AGH), i.e., T2D-H plus IGT-H, had a diminished glucagon suppression index compared to patients with normal glucose homeostasis (NGT-H plus NGT-nH) (p = .035).. GLP-1 responses to glucose were similar in Hispanic and Non-Hispanic NGT. Despite similar glucose-induced Δ-GLP-1, insulin and glucagon responses were abnormal in T2D-H and AGH, respectively. Thus, impaired GLP-1 secretion is unlikely to play a role in islet dysfunction in T2D. Although GLP-1 therapeutics enhance insulin secretion and glucagon suppression, it is likely due to pharmacological amplification of the GLP-1 pathways rather than treatment of hormonal deficiency. Topics: Adult; Blood Glucose; Diabetes Mellitus, Type 2; Female; Glucagon-Like Peptide 1; Glucose Intolerance; Hispanic or Latino; Humans; Male; Middle Aged | 2018 |
Enteroendocrine and adipokine associations with type 2 diabetes: Phenotypic risk scoring approaches.
The contribution of gut-derived factors to the mechanisms linking obesity and metabolic disease remains under-investigated. The aim of the current study was to examine the associations between glucagon and enteroendocrine signaling and type 2 diabetes (T2D) using a derived risk score approach. To compare the relative importance of the enteroendocrine system, associations between adipokine measures and T2D were also investigated.. A total of 130 individuals with T2D and 161 individuals without T2D were included in the study. Circulating concentrations of enteroendocrine (glucagon, ghrelin, glucagon-like peptide-1, and gastric inhibitory peptide) and adipokine mediators (adiponectin, leptin, resistin, visfatin, and adipsin) were measured. Standard scores (Z-scores) were determined for each measure and enteroendocrine risk scores (ERS) and adipokine risk scores (ARS) calculated based on summation of the component measures. Associations between both the ERS and ARS and T2D status were assessed using logistic regression models.. The ERS was significantly associated with T2D status in an adjusted model (odds ratio: 1.36; 95% confidence interval [CI]: 1.08-1.72; P = 0.009). Associations between the ARS and T2D status were not independent of age, sex, and body mass index (odds ratio: 1.21; 95%CI: 0.99-1.47; P = 0.06). Quantification of risk across ERS tertiles revealed that individuals with an ERS in the upper tertile were 10 times more likely (CI: 3.23-32.73; P < 0.001) to have T2D.. These data support an association between enteroendocrine signaling and T2D. Use of the ERS as a potential tool for classifying individuals with metabolic syndrome as high or low risk for T2D development is being considered. Topics: Adipokines; Adolescent; Adult; Aged; Body Mass Index; Diabetes Mellitus, Type 2; Female; Gastric Inhibitory Polypeptide; Ghrelin; Glucagon; Glucagon-Like Peptide 1; Humans; Male; Metabolic Syndrome; Middle Aged; Phenotype; Risk Assessment; Young Adult | 2018 |
GLP-1 receptor agonists: differentiation within the class.
Topics: Diabetes Mellitus, Type 2; Glucagon-Like Peptide 1; Glucagon-Like Peptide-1 Receptor; Humans; Hypoglycemic Agents; Liraglutide; Venoms | 2018 |
Poor responders after bariatric surgery - Are there second chances?
Topics: Bariatric Surgery; Cognitive Behavioral Therapy; Combined Modality Therapy; Diabetes Mellitus, Type 2; Diet, Diabetic; Diet, Reducing; Feeding Behavior; Follow-Up Studies; Glucagon-Like Peptide 1; Humans; Hypoglycemic Agents; Obesity, Morbid; Patient Compliance; Postoperative Complications; Recurrence; Reoperation; Risk Factors; Treatment Failure; Weight Gain | 2018 |
Size Effect on Lipid Nanocapsule-Mediated GLP-1 Secretion from Enteroendocrine L Cells.
L cells are enteroendocrine cells located throughout the gastrointestinal tract that secrete physiologically important peptides. The most characterized peptides secreted by L cells are the peptide YY (PYY) and the glucagon-like peptides 1 (GLP-1) and 2 (GLP-2). These peptides are released rapidly into the circulation after oral nutrient ingestion. Recently, lipid-based nanoparticles (NP) have been described as triggers for GLP-1 secretion by L cells. NP physicochemical properties play a key role in the NP-cell interaction, and drive NP cell internalization. We herein hypothesize that lipid-based NP with appropriate size would not only be able to deliver drugs into blood circulation but also act like endogenous ligands to stimulate GLP-1 secretion. We tested five different size (25, 50, 100, 150, and 200 nm) lipid nanocapsules (LNC) on murine L cells in vitro to confirm this hypothesis. Our study showed that GLP-1 secretion was induced only by the 200 nm size LNC, highlighting the importance of LNC particle size on the secretion of GLP-1 by L cells. The different formulations did not affect proglucagon mRNA expression, suggesting that there was not an increased GLP-1 synthesis. As a proof of concept, we further demonstrated in normoglycemic mice that 200 nm LNC administration increases GLP-1 levels by 4- and 3-fold compared to untreated control mice 60 and 180 min after the administration, respectively. Our study suggests that 200 nm LNC as a nanocarrier to encapsulate drug candidates and as a ligand to induce endogenous GLP-1 secretion might represent a promising strategy for type 2 diabetes mellitus treatment. Topics: Animals; Cell Line; Cell Survival; Diabetes Mellitus, Type 2; Enteroendocrine Cells; Glucagon-Like Peptide 1; Incretins; Lipids; Male; Mice; Mice, Inbred C57BL; Microscopy, Confocal; Nanocapsules | 2018 |
Duodenal Exclusion but Not Sleeve Gastrectomy Preserves Insulin Secretion, Making It the More Effective Metabolic Procedure.
There is an ongoing debate on which procedure provides the best treatment for type 2 diabetes. Furthermore, the pathomechanisms of diabetes improvement of partly anatomically differing operations is not fully understood.. A loop duodenojejunostomy (DJOS) with exclusion of one third of intestinal length, a sleeve gastrectomy (SG), or a combination of DJOS + SG was performed in 8-week-old male ZDF rats. One, three, and six months after surgery, an oral glucose tolerance test and measurements of GLP-1, GIP, insulin, and bile acids were conducted.. After an initial (4 weeks) equal glucose control, DJOS and DJOS + SG showed significantly lower glucose levels than SG 3 and 6 months after surgery. There was sharp decline of insulin levels in SG animals over time, whereas insulin levels in DJOS and DJOS + SG were preserved. GIP levels were significantly larger in both groups containing a sleeve at all three time points, whereas GLP-1 was equal in all groups at all time. Bile acid levels were significantly higher in the DJOS compared to the SG group at all time points. Interestingly, the additional SG in the DJOS + SG group led to lower bile acid levels 1 and 6 months postoperatively.. The effect of SG on glucose control was transient, whereas a duodenal exclusion was the more effective procedure in this model due to a sustained pancreatic function with a preserved insulin secretion. Topics: Anastomosis, Surgical; Animals; Bariatric Surgery; Blood Glucose; Body Weight; Diabetes Mellitus, Experimental; Diabetes Mellitus, Type 2; Duodenum; Gastrectomy; Glucagon-Like Peptide 1; Glucose Tolerance Test; Insulin; Insulin Resistance; Insulin Secretion; Insulin-Secreting Cells; Jejunum; Male; Obesity, Morbid; Rats; Rats, Zucker | 2018 |
The role of gut in type 2 diabetes mellitus during whole body gamma irradiation in high-fat diet Wistar rats.
The effects of a low rate (100 mGy/min) fractionated whole body gamma irradiation (FWBGI) at different doses were assessed using a real-time PCR technique on the expression of some target genes implicated in the development of type 2 diabetes mellitus in high-fat diet (HFD) Wistar rats.. HFD Wistar rats were exposed to different doses (12, 24 and 48 Gy) divided into 24 fractions (three times a week for two months), thus, the daily doses were 0.5, 1, 2 Gy, respectively. Total RNA was extracted and the expression of target genes was measured in the four intestinal segments (duodenum, jejunum, ileum and colon).. The pre-diabetic state already induced by HFD was found to be improved by irradiation exposure. This irradiation effect occurs mainly via altered anti-diabetic gene expressions (mRNA and protein levels) of the incretin glucagon-like peptide-1 (GLP-1) overall bowel segments except the colon which has its own specific response to irradiation exposure by the induction of the insulin receptor substrate 4 (IRS-4) and the uncoupling protein 3 (UCP3).. Results could be of great importance suggesting for the first time, a protective role for FWBGI on HFD animal models by increasing GLP-1 and UCP3 levels. Topics: Animals; Diabetes Mellitus, Experimental; Diabetes Mellitus, Type 2; Diet, High-Fat; Dose-Response Relationship, Radiation; Gene Expression Regulation; Glucagon-Like Peptide 1; Glucose Tolerance Test; Insulin Receptor Substrate Proteins; Male; Rats; Rats, Wistar; Real-Time Polymerase Chain Reaction; RNA, Messenger; Uncoupling Protein 3; Whole-Body Irradiation | 2018 |
Incretin-based Drugs and the Incidence of Colorectal Cancer in Patients with Type 2 Diabetes.
Evidence on the safety of the incretin-based drugs (glucagon-like peptide-1 [GLP-1] analogues and dipeptidyl peptidase-4 [DPP-4] inhibitors) with respect to colorectal cancer is contradictory. The objective of this study was to determine whether use of incretin-based drugs is associated with risk of incident colorectal cancer in patients with type 2 diabetes.. Using data from the UK Clinical Practice Research Datalink, we identified a cohort of 112,040 patients newly treated with antidiabetic drugs between 1 January 2007 and 31 March 2015. We modeled use of GLP-1 analogues and DPP-4 inhibitors as time-varying variables and compared them with use of sulfonylureas. We lagged exposures by 1 year for latency and to reduce reverse causality and detection bias. We used time-dependent Cox proportional hazards models to estimate hazard ratios with 95% confidence intervals of incident colorectal cancer associated with the use of GLP-1 analogues and DPP-4 inhibitors overall, by cumulative duration of use and by time since initiation.. During 388,619 person-years of follow-up, there were 733 incident colorectal cancer events (incidence rate: 1.9 per 1,000 person-years). Use of GLP-1 analogues was not associated with colorectal cancer incidence (hazard ratio: 1.0; 95% confidence interval = 0.7, 1.6), nor was use of DPP-4 inhibitors (hazard ratio: 1.2; 95% confidence interval = 1.0, 1.5). There was no evidence of a duration-response relation for either drug.. The results of this large population-based study indicate that use of incretin-based drugs is not associated with colorectal cancer incidence among patients with type 2 diabetes. Topics: Aged; Colorectal Neoplasms; Databases, Factual; Diabetes Mellitus, Type 2; Dipeptidyl-Peptidase IV Inhibitors; Female; Glucagon-Like Peptide 1; Humans; Hypoglycemic Agents; Incidence; Incretins; Longitudinal Studies; Male; Medical Audit; Middle Aged; Proportional Hazards Models; United Kingdom | 2018 |
Sitagliptin improved glucose assimilation in detriment of fatty-acid utilization in experimental type-II diabetes: role of GLP-1 isoforms in Glut4 receptor trafficking.
The distribution of glucose and fatty-acid transporters in the heart is crucial for energy consecution and myocardial function. In this sense, the glucagon-like peptide-1 (GLP-1) enhancer, sitagliptin, improves glucose homeostasis but it could also trigger direct cardioprotective actions, including regulation of energy substrate utilization.. Type-II diabetic GK (Goto-Kakizaki), sitagliptin-treated GK (10 mg/kg/day) and wistar rats (n = 10, each) underwent echocardiographic evaluation, and positron emission tomography scanning for [. Besides of its anti-hyperglycemic effect, sitagliptin-enhanced GLP-1 may ameliorate diastolic dysfunction in type-II diabetes by shifting fatty acid to glucose utilization in the cardiomyocyte, and thus, improving cardiac efficiency and reducing lipolysis. Topics: Animals; Blood Glucose; Cells, Cultured; Diabetes Mellitus, Type 2; Diabetic Cardiomyopathies; Dipeptidyl-Peptidase IV Inhibitors; Disease Models, Animal; Energy Metabolism; Fatty Acids; Glucagon-Like Peptide 1; Glucose Transporter Type 4; Incretins; Male; Mice; Myocytes, Cardiac; Protein Transport; Rats, Wistar; Signal Transduction; Sitagliptin Phosphate | 2018 |
The rs7903146 T allele in transcription factor 7 like 2 (. We genotyped rs7903146 in 608 individuals without diabetes and recorded biochemical data before and after. TT risk-allele homozygotes had 1.6 mg/dL higher baseline fasting glucose levels and 2.5 pg/mL lower glucagon levels per T allele than carriers of other genotypes at baseline. In a subset of participants, the T allele was associated with higher basal glucagon-like peptide 1 (GLP-1) levels at visit 1 (β = 1.52,. Our findings demonstrate that common variation at Topics: Adult; Aged; Alleles; Blood Glucose; Diabetes Mellitus, Type 2; Female; Genotyping Techniques; Glipizide; Glucagon; Glucagon-Like Peptide 1; Glucose Tolerance Test; Humans; Incretins; Male; Metformin; Middle Aged; Polymorphism, Single Nucleotide; Prospective Studies; Retrospective Studies; Risk Factors; Sulfonylurea Compounds; Transcription Factor 7-Like 2 Protein | 2018 |
Sepsis-induced activation of endogenous GLP-1 system is enhanced in type 2 diabetes.
High levels of circulating GLP-1 are associated with severity of sepsis in critically ill nondiabetic patients. Whether patients with type 2 diabetes (T2D) display different activation of the endogenous GLP-1 system during sepsis and whether it is affected by diabetes-related metabolic parameters are not known.. Serum levels of GLP-1 (total and active forms) and its inhibitor enzyme sDPP-4 were determined by ELISA on admission and after 2 to 4 days in 37 sepsis patients with (n = 13) and without T2D (n = 24) and compared to normal healthy controls (n = 25). Correlations between GLP-1 system activation and clinical, inflammatory, and diabetes-related metabolic parameters were performed.. A 5-fold (P < .001) and 2-fold (P < .05) increase in active and total GLP-1 levels, respectively, were found on admission as compared to controls. At 2 to 4 days from admission, the level of active GLP-1 forms in surviving patients were decreased significantly (P < .005), and positively correlated with inflammatory marker CRP (r = 0.33, P = .05). T2D survivors displayed a similar but more enhanced pattern of GLP-1 response than nondiabetic survivors. Nonsurvivors demonstrate an early extreme increase of both total and active GLP-1 forms, 9.5-fold and 5-fold, respectively (P < .05). The initial and late levels of circulating GLP-1 inhibitory enzyme sDPP-4 were twice lower in all studied groups (P < .001), compared with healthy controls.. Taken together, these data indicate that endogenous GLP-1 system is activated during sepsis. Patients with T2D display an enhanced and prolonged activation as compared to nondiabetic patients. Extreme early increased GLP-1 levels during sepsis indicate poor prognosis. Topics: Adult; Aged; Aged, 80 and over; Biomarkers; Case-Control Studies; Critical Illness; Diabetes Mellitus, Type 2; Female; Follow-Up Studies; Glucagon-Like Peptide 1; Humans; Male; Middle Aged; Prognosis; Sepsis; Young Adult | 2018 |
Resolution of type 2 diabetes after sleeve gastrectomy: a 2-step hypothesis.
Weight loss (WL) and altered gut hormonal levels are involved in glucose homeostasis after laparoscopic sleeve gastrectomy (LSG).. The aim of this study was to evaluate the time-related effects of WL, ghrelin, and glucacon-like peptide-1 (GLP-1) plasma concentrations on type 2 diabetes resolution after LSG.. University hospital, Italy.. Ninety-one patients who underwent LSG were investigated. Insulin secretion (insulinogenic index [IGI]), insulin resistance, plasma glucose level and percentage glycated hemoglobin using the oral glucose tolerance test were assessed before surgery, on postoperative day 3, and then at 6, 12, 24, and 36 months after LSG. At the same time points, WL, ghrelin, and GLP-1 levels were determined.. During follow-up, the resolution rate of type 2 diabetes was 9.4%, 42.3%, 71.8%, 81.2%, and 91.8%, respectively. Ghrelin plasma concentrations decreased significantly after LSG (271.5 ± 24.5 pg/mL versus 122.4 ± 23.4 pg/mL, P = .04). GLP-1 plasma concentrations increased significantly after LSG (1.7 ± 2.6 pg/mL versus 2.5 ± 3.4 pg/mL, P = .04). The percentage of excess weight loss and IGI presented a positive linear correlation (r) at all follow-up time points with a strong positive correlation at 12 and 24 months. A strong negative correlation between ghrelin and IGI was recorded during the first 3 days after LSG (r = -.9). GLP-1 and IGI presented a strong positive correlation at day 3 and 6 months (i.e., .8 and .8, respectively).. LSG may affect glucose homeostasis by 2 different time-related modes: a first step in which the hormonal changes play a predominant role in glucose homeostasis and a second step in which the percentage excess weight loss determines the metabolic results. Topics: Adult; Bariatric Surgery; Blood Glucose; Diabetes Mellitus, Type 2; Female; Gastrectomy; Ghrelin; Glucagon-Like Peptide 1; Glycated Hemoglobin; Humans; Insulin; Insulin Resistance; Insulin Secretion; Laparoscopy; Male; Middle Aged; Obesity, Morbid; Prospective Studies; Weight Loss; Young Adult | 2018 |
Discovery of a long-acting glucagon-like peptide-1 analog with enhanced aggregation propensity.
In the course of our search for new GLP-1 analogs, we screened a number of [Ser Topics: Animals; Diabetes Mellitus, Experimental; Diabetes Mellitus, Type 2; Glucagon-Like Peptide 1; Glucose Tolerance Test; Glycated Hemoglobin; Humans; Hypoglycemic Agents; Insulin; Mice; Peptides; Protein Aggregates; Rats; Streptococcaceae | 2018 |
Nanoparticles induced by embedding self-assembling cassette into glucagon-like peptide 1 for improving in vivo stability.
The multiple physiologic characteristics of glucagon-like peptide 1 (GLP-1) make it a promising drug candidate for treating type 2 diabetes mellitus. However, the half-life of GLP-1 is short as a result of degradation by dipeptidyl peptidase IV and renal clearance. Stabilizing GLP-1 is therefore critical for its use in drug development. Self-assembling peptides are a class of peptides that undergo spontaneous assembly into ordered nanostructures. Recently, studies of self-assembling peptides as drug carriers have increased because of their enhanced stability. In the present study, GLP-1 was modified to incorporate the structural characteristics of self-assembling peptides aiming to generate a self-assembling GLP-1 derivative. Receptor binding capacity and insulinotropic effects were measured to investigate the physiologic functions of GLP-1, along with morphologic approaches to observe supramolecular formation on self-assembly at the nano scale. Finally, blood glucose regulation and body weight were monitored after administration of selected derivatives. Our findings revealed that cadyglp1e and cadyglp1m both exhibited improved stability even though different nanoshapes were observed for these two self-assembling peptides. Both cadyglp1e and cadyglp1m retained glucoregulatory activity after insulin stimulation and were potent drug candidates for long-acting GLP-1 derivatives to treat type 2 diabetes mellitus. Our findings support the feasibility of introducing self-assembly functions into peptides with poor stabilities, such as GLP-1.-Li, Y., Cui, T., Kong, X., Yi, X., Kong, D., Zhang, J., Liu, C., Gong, M. Nanoparticles induced by embedding self-assembling cassette into glucagon-like peptide 1 for improving in vivo stability. Topics: Animals; Blood Glucose; Body Weight; Diabetes Mellitus, Type 2; Drug Carriers; Glucagon-Like Peptide 1; Male; Nanoparticles; Protein Stability; Rats; Rats, Wistar | 2018 |
Therapeutic Potential of Lentivirus-Mediated Glucagon-Like Peptide-1 Gene Therapy for Diabetes.
Postprandial glucose-induced insulin secretion from the islets of Langerhans is facilitated by glucagon-like peptide-1 (GLP-1)-a metabolic hormone with insulinotropic properties. Among the variety of effects it mediates, GLP-1 induces delta cell secretion of somatostatin, inhibits alpha cell release of glucagon, reduces gastric emptying, and slows food intake. These events collectively contribute to weight loss over time. During type 2 diabetes (T2DM), however, the incretin response to glucose is reduced and accompanied by a moderate reduction in GLP-1 secretion. To compensate for the reduced incretin effect, a human immunodeficiency virus-based lentiviral vector was generated to deliver DNA encoding human GLP-1 (LentiGLP-1), and the anti-diabetic efficacy of LentiGLP-1 was tested in a high-fat diet/streptozotocin-induced model of T2DM. Therapeutic administration of LentiGLP-1 reduced blood glucose levels in obese diabetic Sprague Dawley rats, along with improving insulin sensitivity and glucose tolerance. Normoglycemia was correlated with increased blood GLP-1 and pancreatic beta cell regeneration in LentiGLP-1-treated rats. Plasma triglyceride levels were also normalized after LentiGLP-1 injection. Collectively, these data suggest the clinical potential of GLP-1 gene transfer therapy for the treatment of T2DM. Topics: Animals; Diabetes Mellitus, Type 2; Disease Models, Animal; Genetic Therapy; Glucagon-Like Peptide 1; Glucose; Humans; Incretins; Insulin; Islets of Langerhans; Lentivirus; Obesity; Rats | 2018 |
Tissue expression of DPP-IV in obesity-diabetes and modulatory effects on peptide regulation of insulin secretion.
Dipeptidyl peptidase type 4 (DPP-4) inhibitors represent an important class of glucose-lowering drug for type 2 diabetes. DPP-4 enzyme activity has been observed to be significantly altered in type 2 diabetes. Here, the role of DPP-4 was examined in a high fat fed (HFF) mouse model of insulin resistance. HFF mice had an increased bodyweight (p < .01), were hyperglycaemic (p < .01) and hyperinsulinaemic (p < .05). Compared to normal diet, HFF mice exhibited increased plasma DPP-4 activity (p < .01). Tissue distribution patterns in lean and HFF mice demonstrated highest levels of DPP-4 activity in lung (20-26 μmol/min/mg protein) and small intestine (13-14 μmol/min/mg protein), and lowest activity in the spleen (3.8 μmol/min/mg protein). Modulation of DPP-4 activity by high fat feeding was observed in several tissues with increases in the lung (p < .05), liver (p < .05), kidney (p < .05) and pancreas (p < .05). With a high fat diet, DPP-4 gene expression was upregulated in the liver (p < .001) and downregulated in the pancreas (p < 0.001) and small intestine (p < .001). Immunohistochemical analysis revealed increased DPP-4 immunostaining localised primarily in the pancreatic islets of HFF mice (p < .01) with no change in islet GLP-1 expression. Treatment of HFF mice with metformin for 21-days resulted in inhibition of circulating DPP-4 activity (p < .05), decreased blood glucose (p < .05) and increased GLP-1 gene expression (p < .001). These data indicate that DPP-4 is modulated in a tissue specific manner and is dependent on physiological conditions such as hyperglycaemia and insulin resistance, suggesting a significant role in disorders such as diabetes. Topics: Animals; Blood Glucose; Diabetes Mellitus, Type 2; Diet, High-Fat; Dipeptidyl Peptidase 4; Dipeptidyl-Peptidase IV Inhibitors; Gene Expression Regulation; Glucagon-Like Peptide 1; Glucose; Humans; Hypoglycemic Agents; Insulin; Insulin Resistance; Insulin Secretion; Islets of Langerhans; Metformin; Mice; Obesity | 2018 |
Effect of adding GLP-1RA on mortality, cardiovascular events, and metabolic outcomes among insulin-treated patients with type 2 diabetes: A large retrospective UK cohort study.
Combining a GLP-1 receptor agonist (GLP-1RA) with insulin is often an effective treatment strategy for overweight patients with type 2 diabetes (T2D), but little is known about the longer-term effects on cardiovascular and mortality outcomes in routine clinical practice in the United Kingdom. We therefore compared the times to a major nonfatal cardiovascular (CV) event and all-cause mortality among overweight patients with T2D treated with insulin alone versus insulin+GLP-1RA in a large UK database.. A retrospective cohort study was conducted in 18,227 patients with insulin-treated T2D from UK General Practices using The Health Improvement Network database. The 5-year risk of mortality and a 3-point composite of all-cause mortality and nonfatal CV outcomes (myocardial infarction or stroke) was compared between a propensity score-matched cohort of those on insulin alone (n=1,793) and insulin+GLP-1RA (n=1,793), irrespective of other diabetes therapies, providing a total of 12,682 person-years of follow-up. Cox proportional hazard models were used to estimate the hazard ratios of the outcomes.. Hemoglobin A1c reduction was similar between both groups (-0.42 vs -0.33%, P=.089 at 12 months). Overall, 3-point composite events of all-cause mortality and CV events (major adverse cardiovascular even) were 98 versus 55 for the insulin alone versus insulin+GLP-1RA groups, respectively (14.7 vs 9.2 per 1,000 person-years; adjusted hazard ratio [aHR]: 0.64; 95% CI: 0.42-0.98; P=.038). Corresponding composite nonfatal CV events were 33 versus 28 (6.0 vs 5.6 per 1,000 person-years; aHR: 0.76; 95% CI: 0.41-1.42; P=.393), whereas all-cause mortality events were 49 versus 13 (6.9 vs 2.0 per 1,000 person-years; aHR: 0.35; 95% CI: 0.17-0.73; P=.005).. Based on a large UK cohort in routine clinical practice, adding a GLP-1RA to insulin therapy is associated with a reduction in risk of composite CV events and all-cause mortality but a nonsignificant higher risk of hospitalization for heart failure in overweight patients with T2D. Topics: Adult; Aged; Body Mass Index; Cardiovascular Diseases; Cohort Studies; Diabetes Mellitus, Type 2; Drug Therapy, Combination; Female; Glucagon-Like Peptide 1; Humans; Hypoglycemic Agents; Insulin; Male; Middle Aged; Overweight; Propensity Score; Proportional Hazards Models; Retrospective Studies; Severity of Illness Index; Survival Analysis; United Kingdom | 2018 |
Glutamine up-regulates pancreatic sodium-dependent neutral aminoacid transporter-2 and mitigates islets apoptosis in diabetic rats.
Glutamine aminoacid regulates insulin exocytosis from pancreatic β-cells. Liraglutide is a glucagon-like peptide-1 (GLP-1) analogue that has fascinated function in inhibiting β-cell apoptosis and preserving pancreatic β-cell mass. The present study investigated the benefit of adding glutamine to a regimen of liraglutide in diabetic rats focusing on their role in increasing insulin production and upregulation of the expression of sodium-dependent neutral aminoacid transporter-2 (SNAT2).. In the present study, diabetes mellitus was induced in rats using streptozotocin (STZ, 50mg/kg, ip). Male rats were allocated into 5 groups, (i) vehicle group, (ii) STZ-diabetic rats, (iii) STZ-diabetic rats treated with liraglutide (150μg/kg, sc), (iv) STZ-diabetic rats treated with glutamine (po) and (v) STZ-diabetic rats treated with a combination of liraglutide and glutamine for four weeks. After finishing the therapeutic courses, the fasting blood glucose value was determined and rats were sacrificed. Pancreases were used for quantification of mRNA expression for SNAT2. Paraffin fixed samples were used for histologic staining and immunohistochemistry for insulin and apoptosis markers (activated caspase-3, BCL2 and BAX).. Treatment with liraglutide and/or glutamine enhanced insulin production and hence glycemic control in diabetic male rats with favorable effects on apoptosis markers. Treatment with glutamine and its combination with liraglutide significantly increased pancreatic expression of SNAT2 by approximately 30-35 folds.. Addition of glutamine to liraglutide regimen enhances the glycemic control and may have utility in clinical settings. Topics: Amino Acid Transport System A; Amino Acid Transport Systems; Animals; Apoptosis; Blood Glucose; Diabetes Mellitus, Experimental; Diabetes Mellitus, Type 2; Glucagon-Like Peptide 1; Glutamine; Hypoglycemic Agents; Insulin; Insulin-Secreting Cells; Islets of Langerhans; Liraglutide; Male; Pancreas; Rats; Streptozocin; Up-Regulation | 2018 |
SGLT2 inhibitors and GLP-1 receptor agonists: a sound combination.
Topics: Diabetes Mellitus, Type 2; Dipeptidyl-Peptidase IV Inhibitors; Double-Blind Method; Glucagon-Like Peptide 1; Glucagon-Like Peptide-1 Receptor; Glucagon-Like Peptides; Humans; Hypoglycemic Agents; Immunoglobulin Fc Fragments; Recombinant Fusion Proteins; Sodium-Glucose Transporter 2 | 2018 |
Sodium-glucose co-transporter-2 inhibitors, the latest residents on the block: Impact on glycaemic control at a general practice level in England.
To determine, using published general practice-level data, how differences in Type 2 diabetes mellitus (T2DM) prescribing patterns relate to glycaemic target achievement levels.. Multiple linear regression modelling was used to link practice characteristics and defined daily dose (DDD) of different classes of medication in 2015/2016 and changes between that year and the year 2014/2015 in medication to proportion of patients achieving target glycaemic control (glycated haemoglobin A1c [HbA1c] ≤58 mmol/mol [7.5%]) and proportion of patients at high glycaemic risk (HbA1c >86 mmol/mol [10.0%]) for practices in the National Diabetes Audit with >100 people with T2DM on their register.. Overall, HbA1c outcomes were not different between the years studied. Although, in percentage terms, most practices increased their use of sodium-glucose co-transporter-2 (SGLT2) inhibitors (96%), dipeptidyl peptidase-4 (DPP-4) inhibitors (76%) and glucagon-like peptide 1 (GLP-1) analogues (53%), there was wide variation in the use of older and newer therapies. For example, 12% of practices used >200% of the national average for some newer agents. In cross-sectional analysis, greater prescribing of metformin and analogue insulin were associated with a higher proportion of patients achieving HbA1c ≤58 mmol/mol; the use of SGLT2 inhibitors and metformin was associated with a reduced proportion of patients with HbA1c >86 mol/mol; otherwise associations for sulphonylureas, GLP-1 analogues, SGLT2 inhibitors and DPP-4 inhibitors were neutral or negative. In year-on-year analysis there was ongoing deterioration in glycaemic control, which was offset to some extent by increased use of SGLT2 inhibitors and GLP-1 analogues, which were associated with a greater proportion of patients achieving HbA1c levels ≤58 mmol/mol and a smaller proportion of patients with HbA1c levels >86 mmol/mol. SGLT2 inhibitor prescribing was associated with significantly greater improvements than those found for GLP-1 analogues.. Greater use of newer agents was associated with improvement in glycaemic outcomes but was not sufficient to compensate for the prevailing decline. This may reflect wide variability in the prescribing of newer agents. We found that SGLT inhibitors may be superior to other oral agents in relation to HbA1c outcome. Serious consideration should be given to their use. Topics: Aged; Blood Glucose; Cross-Sectional Studies; Diabetes Mellitus, Type 2; Dipeptidyl-Peptidase IV Inhibitors; Drug Therapy, Combination; England; Female; General Practice; General Practitioners; Glucagon-Like Peptide 1; Glycated Hemoglobin; Humans; Hypoglycemic Agents; Linear Models; Male; Metformin; Middle Aged; Practice Patterns, Physicians'; Sodium-Glucose Transporter 2 Inhibitors; Sulfonylurea Compounds | 2018 |
Liraglutide, a human glucagon-like peptide-1 analogue, stimulates AKT-dependent survival signalling and inhibits pancreatic β-cell apoptosis.
Liraglutide, a human long-lasting GLP-1 analogue, is currently regarded as a powerful treatment option for type 2 diabetes. Apart from glucoregulatory and insulinotropic actions, liraglutide increases β-cell mass through stimulation of β-cell proliferation and islet neogenesis, as well as inhibition of β-cell apoptosis. However, the underline molecular mechanisms have not been fully characterized. In this study, we investigated the mechanism by which liraglutide preserves islet β-cells in an animal model of overt diabetes, the obese db/db mice, and protects a mouse pancreatic β-cell line (βTC-6 cells) against apoptosis. Treatment of 12-week-old diabetic mice with liraglutide for 2 weeks had no appreciable effects on blood non-fasting glucose concentration, islet insulin content and body weight. However, morphological and biochemical examination of diabetic mouse pancreatic islets demonstrated that liraglutide restores islet size, reduces islet β-cell apoptosis and improves nephrin expression, a protein involved in β-cell survival signalling. Our results indicated that liraglutide protects βTC-6 cells from serum withdrawal-induced apoptosis through inhibition of caspase-3 activation. The molecular mechanism of the anti-apoptotic action of liraglutide in βTC-6-cells comprises stimulation of PI3-kinase-dependent AKT phosphorylation leading to the phosphorylation, hence inactivation of the pro-apoptotic protein BAD and inhibition of FoxO1 transcription factor. In conclusion, we provided evidence that the GLP-1 analogue liraglutide exerts important beneficial effects on pancreatic islet architecture and β-cell survival by protecting cells against apoptosis. These findings extend our understanding of the actions of liraglutide and further support the use of GLP-1R agonists in the treatment of patients with type 2 diabetes. Topics: Animals; Apoptosis; Cell Line; Cell Proliferation; Cell Survival; Diabetes Mellitus, Type 2; Forkhead Box Protein O1; Glucagon-Like Peptide 1; Humans; Hypoglycemic Agents; Insulin; Insulin-Secreting Cells; Liraglutide; Mice; Mice, Obese; Phosphatidylinositol 3-Kinases; Phosphorylation; Proto-Oncogene Proteins c-akt; Signal Transduction | 2018 |
Roux-en-Y gastric bypass compared with equivalent diet restriction: Mechanistic insights into diabetes remission.
To investigate the physiological mechanisms leading to rapid improvement in diabetes after Roux-en-Y gastric bypass (RYGB) and specifically the contribution of the concurrent peri-operative dietary restrictions, which may also alter glucose metabolism.. In order to assess the differential contributions of diet and surgery to the mechanisms leading to the rapid improvement in diabetes after RYGB we enrolled 10 patients with type 2 diabetes scheduled to undergo RYGB. All patients underwent a 10-day inpatient supervised dietary intervention equivalent to the peri-operative diet (diet-only period), followed by, after a re-equilibration (washout) period, an identical period of pair-matched diet in conjunction with RYGB (diet and RYGB period). We conducted extensive metabolic assessments during a 6-hour mixed-meal challenge test, with stable isotope glucose tracer infusion performed before and after each intervention.. Similar improvements in glucose levels, β-cell function, insulin sensitivity and post-meal hepatic insulin resistance were observed with both interventions. Both interventions led to significant reductions in fasting and postprandial acyl ghrelin. The diet-only intervention induced greater improvements in basal hepatic glucose output and post-meal gastric inhibitory polypeptide (GIP) secretion. The diet and RYGB intervention induced significantly greater increases in post-meal glucagon-like peptide-1 (GLP-1), peptide YY (PYY) and glucagon levels.. Strict peri-operative dietary restriction is a main contributor to the rapid improvement in glucose metabolism after RYGB. The RYGB-induced changes in the incretin hormones GLP-1 and PYY probably play a major role in long-term compliance with such major dietary restrictions through central and peripheral mechanisms. Topics: Blood Glucose; Caloric Restriction; Diabetes Mellitus, Type 2; Fasting; Female; Gastric Bypass; Gastric Inhibitory Polypeptide; Ghrelin; Glucagon; Glucagon-Like Peptide 1; Humans; Insulin Resistance; Insulin Secretion; Insulin-Secreting Cells; Liver; Male; Middle Aged; Obesity; Peptide YY; Postprandial Period; Remission Induction | 2018 |
The pattern of prescribing of glucose modulating agents for type 2 diabetes in general practices in England 2016/17.
In the financial year 2016/17 there were 52.0 million items prescribed for diabetes at a total net ingredient cost of £983.7 million - up from 28.9 million prescription items and £572.4 million in 2006/07. Anti-diabetes drugs (British National Formulary section 6.1.2) make up 45.1 per cent of the total £983.7 million net ingredient cost of drugs used in diabetes and account for 72.0 per cent of prescription items for all diabetes prescribing.. We examined the way that agents licensed to treat type 2 diabetes were used across GP practices in England in the year 2016/2017. Analysis was at a GP practice level not at the level of patient data.. Annual prescribing costs / patient / medication type for monotherapy varied considerable from £11/year for gliclazide and glimepiride to £885/year for Liraglutide. The use of SGLT-2i agents grew strongly at 70% per annum to around 100,000 DDD with prescriptions seen in 95% of GP practices. Liraglutide expenditure (11% of total) was high for a relatively small number of patients (1.3% of Defined Daily Doses), with still significant spend on exenatide. Liraglutide use significantly exceeded that of other glucagon-like peptide-1 (GLP-1) agonists.. Our work demonstrates the significant cost of medication to modulate tissue glucose levels in type 2 diabetes and the dominance of some non-generic preparations in terms of number of prescriptions and overall spend. There are some older sulphonylureas in use, which should not generally be prescribed. Regular audit of patient treatment at a general practice level will ensure appropriate targeted use of licensed medications and of their cost effectiveness. Topics: Cost-Benefit Analysis; Diabetes Mellitus, Type 2; Drug Costs; Drug Prescriptions; England; Exenatide; General Practice; Gliclazide; Glucagon-Like Peptide 1; Humans; Hypoglycemic Agents; Liraglutide; Peptides; Practice Patterns, Physicians'; Sodium-Glucose Transporter 2; Sodium-Glucose Transporter 2 Inhibitors; Sulfonylurea Compounds; Venoms | 2018 |
Impaired Secretion of Glucagon-Like Peptide 1 in Patients with Colorectal Adenoma after an Oral Glucose Load.
Obesity and insulin resistance are associated with an increased risk of colorectal adenoma (CRA). Glucagon-like peptide-1 (GLP-1) plays an important role in glucose homeostasis through its amplification of insulin secretion in response to oral nutrients; however, its role in human CRA remains unknown. We investigated oral glucose-mediated GLP-1 secretion in patients with adenoma.. We performed a case-control study of 15 nondiabetic patients with pathologically diagnosed CRA and 10 age-matched healthy controls without adenoma. Plasma concentrations of active GLP-1 were measured during a 75 g oral glucose tolerance test.. Mean waist circumference (WC), homeostasis model assessment of insulin resistance (HOMA-IR) values, the total areas under the curve (AUC) of glucose and insulin were significantly higher in patients with CRA than in controls. The total AUC of GLP-1 (p = 0.01) was lower in patients with CRA than in controls. Moreover, the total AUC of GLP-1 showed a negative correlation with WC, total AUC of glucose, and HOMA-IR. Multiple linear regression analyses revealed that the total AUC of GLP-1 was independently correlated with the number and maximum size of CRAs.. GLP-1 could actively participate in the development of CRA in humans, particularly in patients with metabolic syndrome. Topics: Adenoma; Adult; Aged; Blood Glucose; Case-Control Studies; Colonoscopy; Colorectal Neoplasms; Comorbidity; Diabetes Mellitus, Type 2; Female; Glucagon-Like Peptide 1; Glucose Tolerance Test; Humans; Insulin; Insulin Secretion; Male; Metabolic Syndrome; Middle Aged | 2018 |
HBA1C CONTROL AND COST-EFFECTIVENESS IN PATIENTS WITH TYPE 2 DIABETES MELLITUS INITIATED ON CANAGLIFLOZIN OR A GLUCAGON-LIKE PEPTIDE 1 RECEPTOR AGONIST IN A REAL-WORLD SETTING.
To compare glycated hemoglobin (HbA1c) control and medication costs between patients with type 2 diabetes mellitus (T2DM) treated with canagliflozin 300 mg (CANA) or a glucagon-like peptide 1 receptor agonist (GLP-1 RA) in a real-world setting.. Adults with T2DM newly initiated on CANA or a GLP-1 RA (index date) were identified from IQVIA. For both cohorts (CANA: n = 11,435; GLP-1 RA: n = 11,582), HbA1c levels decreased at 3 months postindex and remained lower through 30 months. Absolute changes in mean HbA1c from index to 3 months postindex for CANA and GLP-1 RA were -1.16% and -1.21% (patients with baseline HbA1c ≥7% [53 mmol/mol]); -1.54% and -1.51% (patients with baseline HbA1c ≥8% [64 mmol/mol]); and -2.13% and -1.99% (patients with baseline HbA1c ≥9% [75 mmol/mol]), respectively. Postindex, CANA patients with baseline HbA1c ≥7% had similar HbA1c levels at each interval versus GLP-1 RA patients, except 9 months (mean HbA1c, 7.75% [61 mmol/mol] vs. 7.86% [62 mmol/mol]; P = .0305). CANA patients with baseline HbA1c ≥8% and ≥9% had consistently lower HbA1c numerically versus GLP-1 RA patients and statistically lower HbA1c at 9 (baseline HbA1c ≥8% or ≥9%), 27, and 30 months (baseline HbA1c ≥9%). Continuous 12-month medication cost $3,326 less for CANA versus GLP-1 RA.. This retrospective study demonstrated a similar evolution of HbA1c levels among CANA and GLP-1 RA patients in a real-world setting. Lower medication costs suggest CANA is economically dominant over GLP-1 RA (similar effectiveness, lower cost).. AHA = antihyperglycemic agent BMI = body mass index CANA = canagliflozin 300 mg DCSI = diabetes complications severity index eGFR = estimated glomerular filtration rate EMR = electronic medical record GLP-1 RA = glucagon-like peptide 1 receptor agonist HbA1c = glycated hemoglobin ICD-9-CM = International Classification of Diseases-Ninth Revision-Clinical Modification ICD-10-CM = International Classification of Diseases-Tenth Revision-Clinical Modification IPTW = inverse probability of treatment weighting ITT = intent-to-treat MPR = medication possession ratio PDC = proportion of days covered PS = propensity score PSM = propensity score matching Quan-CCI = Quan-Charlson comorbidity index SGLT2 = sodium-glucose cotransporter 2 T2DM = type 2 diabetes mellitus WAC = wholesale acquisition cost. Topics: Adolescent; Adult; Aged; Aged, 80 and over; Canagliflozin; Comorbidity; Cost-Benefit Analysis; Diabetes Complications; Diabetes Mellitus, Type 2; Electronic Health Records; Female; Glucagon-Like Peptide 1; Glycated Hemoglobin; Health Care Costs; Humans; Hypoglycemic Agents; Male; Middle Aged; Retrospective Studies; Young Adult | 2018 |
Don't Play with Your Nodule: Case Report of Tachycardia and Other Adverse Reactions from Manipulation of an Exenatide Injection Site Nodule.
Type II diabetes mellitus (DM) is an increasingly prevalent cause of morbidity and mortality among U.S. adults, with increasing prevalence in emergency department (ED) visits. Multiple medications, such as exenatide, a glucagon-like peptide-1 agonist, have been developed in the past decade to combat this growing problem. This medication is well documented to cause gastrointestinal upset and skin nodules at the injection site. However, currently no documented cases exist regarding manipulation of injection nodules causing increased absorption or reports demonstrating an increase in adverse drug reactions.. We report an interesting case of an adult male patient who likely experienced increased systemic absorption of exenatide by manipulating an injection nodule, which ultimately resulted in nausea, retching, diarrhea, and a tachycardic heart rate of 130-140 beats/min. These symptoms are known side effects of exenatide. WHY SHOULD AN EMERGENCY PHYSICIAN BE AWARE OF THIS?: Given the high frequency of DM patients presenting to the ED, emergency physicians should be familiar with diabetic maintenance medications and their adverse reactions. Treating these side effects and properly educating patients can alleviate discomfort, prevent future adverse reactions, and decrease return visits to the ED. Topics: Chest Pain; Diabetes Mellitus, Type 2; Diarrhea; Emergency Service, Hospital; Exenatide; Glucagon-Like Peptide 1; Humans; Hypoglycemic Agents; Injection Site Reaction; Male; Middle Aged; Nausea; Tachycardia | 2018 |
Quality goal attainment and maintenance in patients with type II diabetes mellitus initiated on canagliflozin or a glucagon-like peptide-1 receptor agonist in an actual practice setting.
To compare achievement of quality goals (HbA1c, weight loss/body mass index [BMI], systolic blood pressure [SBP]), including maintaining HbA1c, between patients with type 2 diabetes mellitus (T2DM) treated with canagliflozin 300 mg (CANA) or a GLP-1 in an actual practice setting.. Adults with T2DM newly initiated on CANA or a GLP-1 were identified from the IQVIA. CANA (n = 11,435) and GLP-1 (n = 11,582) cohorts had similar attainment of HbA1c < 8.0% (64 mmol/mol) and HbA1c < 9.0% (75 mmol/mol; HbA1c < 8.0%: HR [CI] = 0.98 [0.91-1.06]; HbA1c < 9.0%: HR [CI] = 1.02 [0.93-1.12]), while GLP-1 patients were 10% more likely to achieve HbA1c < 7.0% (53 mmol/mol). CANA and GLP-1 patients were similar in maintaining HbA1c < 7.0%, < 8.0%, or <9.0%, achieving weight loss ≥5% (HR [CI] = 1.05 [0.99-1.12]), achieving BMI <30 kg/m. This retrospective study in an actual practice setting showed that CANA patients were generally as likely as GLP-1 patients to achieve HbA1c, weight, and blood pressure thresholds, and to maintain glycemic control while being less likely to discontinue treatment and/or have a new anti-hyperglycemic prescribed. Topics: Blood Pressure; Body Weight; Canagliflozin; Diabetes Mellitus, Type 2; Electronic Health Records; Female; Glucagon-Like Peptide 1; Glucagon-Like Peptide-1 Receptor; Glycated Hemoglobin; Humans; Hypoglycemic Agents; Male; Middle Aged; Patient Preference; Retrospective Studies; Treatment Outcome; United States | 2018 |
MiR-7, miR-9 and miR-375 contribute to effect of Exendin-4 on pancreatic β-cells in high-fat-diet-fed mice.
The purpose of this study was to test whether glucagon-like peptide-1 (GLP-1) receptor activation preserved pancreatic β-cells via the regulation of microRNAs and target genes in high-fat-diet-fed mice.. C57BL/6 male mice were simultaneously treated with high-fat-diet (HFD) and GLP-1 analogue, Exendin-4 (Ex-4) (3 μg/kg/day or 30 μg/kg/day), i.p. or vehicle, for consecutive 13 weeks. Fasting blood glucose, postprandial blood glucose, ΔI30/ΔG30, HOMA-IR and HOMA-% β were measured in each group. Pancreatic β-cell mass was assessed by immunohistochemistry. The expression of miRNAs and related downstream genes were investigated using quantitative real-time PCR.. Thirteen weeks of Ex-4 treatment significantly reduced body weight and food intake in HFD-fed mice (P. Topics: Animals; Diabetes Mellitus, Type 2; Dietary Fats; Exenatide; Glucagon-Like Peptide 1; Insulin-Secreting Cells; Male; Mice; MicroRNAs; Obesity | 2018 |
17-β Estradiol regulates proglucagon-derived peptide secretion in mouse and human α- and L cells.
Clinical and experimental data indicate a beneficial effect of estrogens on energy and glucose homeostasis associated with improved insulin sensitivity and positive effects on insulin secretion. The aim of the study was to investigate the impact of estrogens on proglucagon-producing cells, pancreatic α cells, and enteroendocrine L cells. The consequences of sexual hormone deprivation were evaluated in ovariectomized mice (ovx). Ovx mice exhibited impaired glucose tolerance during oral glucose tolerance tests (OGTT), which was associated with decreased GLP-1 intestinal and pancreatic secretion and content, an effect that was reversed by estradiol (E2) treatment. Indeed, E2 increased oral glucose-induced GLP-1 secretion in vivo and GLP-1 secretion from primary culture of mouse and human α cells through the activation of all 3 estrogen receptors (ERs), whereas E2-induced GLP-1 secretion from mouse and human intestinal explants occurred only by ERβ activation. Underlying the implication of ERβ, its selective agonist WAY20070 was able to restore glucose tolerance in ovx mice at least partly through plasma GLP-1 increase. We conclude that E2 directly controls both α- and L cells to increase GLP-1 secretion, in addition to its effects on insulin and glucagon secretion, highlighting the potential beneficial role of the estrogenic pathway and, more particularly, of ERβ agonists to prevent type 2 diabetes. Topics: Animals; Cells, Cultured; Diabetes Mellitus, Type 2; Enteroendocrine Cells; Estradiol; Estrogen Receptor beta; Female; Glucagon-Like Peptide 1; Glucagon-Secreting Cells; Glucose; Glucose Tolerance Test; Humans; Mice; Mice, Inbred C57BL; Mice, Transgenic; Ovariectomy; Oxazoles; Phenols; Primary Cell Culture | 2018 |
Potential mechanisms underlying differences in the effect of incretin-based antidiabetic drugs on the risk of major atherosclerotic ischemic events.
Topics: Atherosclerosis; Constriction, Pathologic; Diabetes Mellitus, Type 2; Diabetic Angiopathies; Dipeptidyl-Peptidase IV Inhibitors; Drug Design; Glucagon-Like Peptide 1; Glucagon-Like Peptide-1 Receptor; Humans; Hypoglycemic Agents; Incidence; Incretins; Ischemia; Myocardial Infarction; Risk Factors; Signal Transduction; Stroke | 2018 |
Evaluation of novel TGR5 agonist in combination with Sitagliptin for possible treatment of type 2 diabetes.
TGR5 is a member of G protein-coupled receptor (GPCR) superfamily, a promising molecular target for metabolic diseases. Activation of TGR5 promotes secretion of glucagon-like peptide-1 (GLP-1), which activates insulin secretion. A series of 2-thio-imidazole derivatives have been identified as novel, potent and orally efficacious TGR5 agonists. Compound 4d, a novel TGR5 agonist, in combination with Sitagliptin, a DPP-4 inhibitor, has demonstrated an adequate GLP-1 secretion and glucose lowering effect in animal models, suggesting a potential clinical option in treatment of type-2 diabetes. Topics: Animals; Binding Sites; Diabetes Mellitus, Type 2; Drug Therapy, Combination; Female; Glucagon-Like Peptide 1; Half-Life; Humans; Hypoglycemic Agents; Imidazoles; Mice; Mice, Inbred C57BL; Molecular Docking Simulation; Protein Structure, Tertiary; Receptors, G-Protein-Coupled; Sitagliptin Phosphate; Structure-Activity Relationship | 2018 |
Exenatide effects on gastric emptying rate and the glucose rate of appearance in plasma: A quantitative assessment using an integrative systems pharmacology model.
This study aimed to quantify the effect of the immediate release (IR) of exenatide, a short-acting glucagon-like peptide-1 (GLP-1) receptor agonist (GLP-1RA), on gastric emptying rate (GER) and the glucose rate of appearance (GluRA), and evaluate the influence of drug characteristics and food-related factors on postprandial plasma glucose (PPG) stabilization under GLP-1RA treatment. A quantitative systems pharmacology (QSP) approach was used, and the proposed model was based on data from published sources including: (1) GLP-1 and exenatide plasma concentration-time profiles; (2) GER estimates under placebo, GLP-1 or exenatide IR dosing; and (3) GluRA measurements upon food intake. According to the model's predictions, the recommended twice-daily 5- and 10-μg exenatide IR treatment is associated with GluRA flattening after morning and evening meals (48%-49%), whereas the midday GluRA peak is affected to a lesser degree (5%-30%) due to lower plasma drug concentrations. This effect was dose-dependent and influenced by food carbohydrate content, but not by the lag time between exenatide injection and meal ingestion. Hence, GER inhibition by exenatide IR represents an important additional mechanism of its effect on PPG. Topics: Blood Glucose; Diabetes Mellitus, Type 2; Dietary Carbohydrates; Digestion; Dose-Response Relationship, Drug; Drug Administration Schedule; Drug Liberation; Exenatide; Gastric Emptying; Glucagon-Like Peptide 1; Glucagon-Like Peptide-1 Receptor; Humans; Hyperglycemia; Hypoglycemia; Hypoglycemic Agents; Incretins; Intestinal Absorption; Models, Biological; Postprandial Period; Systems Biology | 2018 |
A surface plasmon resonance assay for characterisation and epitope mapping of anti-GLP-1 antibodies.
The incretin hormone glucagon-like peptide-1 (GLP-1) has been subject to substantial pharmaceutical research regarding the treatment of type 2 diabetes mellitus. However, quantification of GLP-1 levels remains complicated due to the low circulation concentration and concurrent existence of numerous metabolites, homologous peptides, and potentially introduced GLP-1 receptor agonists. Surface plasmon resonance (SPR) facilitates real-time monitoring allowing a more detailed characterisation of the interaction compared with conventional enzyme-linked immunosorbent assays (ELISA). In this paper, we describe the development of the first SPR assays for characterisation of anti-GLP-1 antibodies for ELISA purposes. Binding responses were obtained on covalently immobilised anti-GLP-1 antibodies at 12°C, 25°C, and 40°C and fitted to a biomolecular (1:1) interaction model showing association rates of 1.01 × 10 Topics: Antibodies, Anti-Idiotypic; Diabetes Mellitus, Type 2; Enzyme-Linked Immunosorbent Assay; Epitope Mapping; Epitopes; Glucagon-Like Peptide 1; Humans; Kinetics; Protein Binding; Surface Plasmon Resonance; Thermodynamics | 2018 |
Targeting GLP-1 receptor trafficking to improve agonist efficacy.
Glucagon-like peptide-1 receptor (GLP-1R) activation promotes insulin secretion from pancreatic beta cells, causes weight loss, and is an important pharmacological target in type 2 diabetes (T2D). Like other G protein-coupled receptors, the GLP-1R undergoes agonist-mediated endocytosis, but the functional and therapeutic consequences of modulating GLP-1R endocytic trafficking have not been clearly defined. Here, we investigate a series of biased GLP-1R agonists with variable propensities for GLP-1R internalization and recycling. Compared to a panel of FDA-approved GLP-1 mimetics, compounds that retain GLP-1R at the plasma membrane produce greater long-term insulin release, which is dependent on a reduction in β-arrestin recruitment and faster agonist dissociation rates. Such molecules elicit glycemic benefits in mice without concomitant increases in signs of nausea, a common side effect of GLP-1 therapies. Our study identifies a set of agents with specific GLP-1R trafficking profiles and the potential for greater efficacy and tolerability as T2D treatments. Topics: Animals; Blood Glucose; Cell Membrane; CHO Cells; Cricetulus; Diabetes Mellitus, Experimental; Diabetes Mellitus, Type 2; Endocytosis; Glucagon-Like Peptide 1; Glucagon-Like Peptide-1 Receptor; HEK293 Cells; Humans; Hypoglycemic Agents; Insulin; Insulin-Secreting Cells; Male; Mice; Mice, Inbred C57BL; Nausea; Primary Cell Culture; Protein Transport; RNA, Small Interfering; Treatment Outcome | 2018 |
Comparison of low-dose liraglutide use versus other GLP-1 receptor agonists in patients without type 2 diabetes.
The objective was to compare the use of low-dose liraglutide (LD-L) (Victoza) to the other glucagon-like peptide-1 receptor agonists (GLP-1 RAs) in patients without a type 2 diabetes (T2D) diagnosis in the post approval period for high-dose liraglutide (HD-L) (Saxenda), which is not indicated for T2D.. This was a retrospective, repeated cross-sectional, cohort study.. Adult patients with T2D with more than 1 prescription for a GLP-1 RA in the Optum Humedica database between December 2014 and March 2016 were included. The proportions of patients without a T2D diagnosis who were prescribed L-DL versus the other GLP-1 RAs and within each cohort were computed. Logistic regression models estimated the predictive value of either treatment in those without a T2D diagnosis, controlling for multiple factors. To supplement these findings, administrative claims data were extracted from the Truven Health MarketScan database.. Analyses identified 11,245 patients prescribed LD-L and 4134 patients prescribed other GLP-1 RAs. For the entire study period, Humedica data revealed that patients without T2D accounted for 2.7% of the GLP-1 RA cohort and 17.5% of the LD-L cohort. Multivariable logistic regression analyses identified that patients receiving LD-L were more than 6 times likely to have no indication of T2D relative to patients taking other GLP-1 RAs. Claims data from MarketScan corroborated the Humedica results.. In patients without a T2D diagnosis, LD-L use was significantly greater than that with other GLP-1 RAs within 6 months after approval of HD-L; differences persisted until the end of the study. Increased payer scrutiny of appropriate LD-L use is warranted. Topics: Adult; Cohort Studies; Cross-Sectional Studies; Diabetes Mellitus, Type 2; Drug Administration Schedule; Female; Glucagon-Like Peptide 1; Humans; Hypoglycemic Agents; Liraglutide; Male; Medication Adherence; Retrospective Studies | 2018 |
Effects of Diet on Bile Acid Metabolism and Insulin Resistance in Type 2 Diabetic Rats after Roux-en-Y Gastric Bypass.
Roux-en-Y gastric bypass (RYGB) is effective for the treatment of type 2 diabetes mellitus; however, the mechanism remains unclear.. The effects of RYGB on postprandial responses to three different diets (low carbohydrate (CH)-rich diet, high CH-rich diet, and fat-rich diet) of different nutritional composition in a Goto-Kakizaki (GK) diabetic rat model were assessed by measuring glucose tolerance, insulin resistance, incretin responses, and bile acid (BA) metabolism.. GK-RYGB group rats lost weight and preferred low CH-rich diet, but there were no significant differences in BW among the different diets. Glucose tolerance and insulin resistance were improved in rats who underwent RYGB, together with higher levels of circulating BAs, plasma GLP-1, and PYY levels. GK-RYGB rats fed high CH-rich or fat-rich diet showed increased glucose level and insulin resistance, together with high plasma BA, GIP, and PYY levels compared to those fed a low CH-rich diet.. RYGB improves glucose tolerance and insulin resistance which may be related to BA metabolism and hormone levels, and the nutrient composition of the diet affects the treatment effect of RYGB on T2DM. Topics: Animals; Bile Acids and Salts; Blood Glucose; Diabetes Mellitus, Experimental; Diabetes Mellitus, Type 2; Diet; Gastric Bypass; Glucagon-Like Peptide 1; Insulin Resistance; Rats | 2018 |
Differential GIP/GLP-1 intestinal cell distribution in diabetics' yields distinctive rearrangements depending on Roux-en-Y biliopancreatic limb length.
As incretins are known to play an important role in type 2 diabetics (T2D) improvement observed after Roux-en-Y gastric bypass (RYGB), our aim was to assess whether increasing the length of RYGB biliopancreatic limb in T2D would modify the incretin staining cell density found after the gastric outlet. Small intestine biopsies (n = 38) were harvested during RYGB at two different distances from the duodenal angle; either 60-90 cm (n = 28), from non-diabetic (n = 18) patients, and T2D (n = 10), or 200 cm (n = 10) from T2D. GIP and GLP-1 staining cells were identified by immunohistochemistry and GLP-1/GIP co-staining cells by immunofluorescence. Incretin staining cell density at the proximal small intestine of T2D and non-diabetic individuals was similar. At 200 cm, T2D patients depicted a significantly lower GIP staining cell density (0.181 ± 0.016 vs 0.266 ± 0.033, P = 0.038) with a similar GLP-1 staining cell density when compared to the proximal gut. GIP/GLP-1 co-staining cells was similar in all studied groups. In T2D patients, the incretin staining cells density in the distal intestine is significantly different from the proximal gut. Thus, a longer RYGB biliopancreatic limb produces a distinctive incretin cell pattern at the gastro-enteric anastomosis that can result in different endocrine profiles. Topics: Adult; Diabetes Mellitus, Type 2; Enteroendocrine Cells; Female; Gastric Bypass; Glucagon-Like Peptide 1; Humans; Incretins; Intestine, Small; Male; Obesity | 2018 |
How does glucagon-like peptide 1 stimulate human β-cell proliferation? A lesson from islet graft experiments.
The incidence of type 2 diabetes increases with age. The age-dependent decline in functional β-cell mass contributes to the increased risk of onset of diabetes, reflecting the central role of pancreatic β-cells in glucose homeostasis. Indeed, the replication rate of human and rodent β-cells is known to decline sharply with age, and such a characteristic of β-cells might explain the increased onset of type 2 diabetes in the older population. The molecular mechanism involved in the age-dependent decline of β-cell proliferation has been extensively studied, mainly using rodents and in vitro culture systems, but its molecular basis is still largely unknown. A mechanism by which glucagon-like peptide-1 receptor activation induces human β-cell proliferation only within a restricted time window was recently suggested in a study in which human islets were grafted into immunodeficient mice. The authors found that the mitogenic effects of exendin-4 require calcineurin/nuclear factor of activated T-cells signaling, and that only in juvenile islets, exendin-4 induced the expression of nuclear factor of activated T-cells signaling components, as well as downstream target genes that facilitate β-cell proliferation. These findings provide a mechanistic explanation as to why glucagon-like peptide 1 exerts mitogenic effects only in juvenile human β-cells. Topics: Animals; Cell Proliferation; Diabetes Mellitus, Type 2; Glucagon-Like Peptide 1; Humans; Insulin-Secreting Cells; Islets of Langerhans; Mice; Signal Transduction; Transplants | 2018 |
Mechanisms in bariatric surgery: Gut hormones, diabetes resolution, and weight loss.
Gastric bypass surgery leads to profound changes in the secretion of gut hormones with effects on metabolism, appetite, and food intake. Here, we discuss their contributions to the improvement in glucose tolerance and the weight loss that results from the operations. We find that the improved glucose tolerance is due the following events: a negative energy balance and resulting weight loss, which improve first hepatic and later peripheral insulin sensitivity, in combination with increased postprandial insulin secretion elicited particularly by exaggerated glucagon-like peptide-1 responses. The weight loss is due to loss of appetite resulting in reduced energy intake, and we find it probable that this process is driven by exaggerated secretion of appetite-regulating gut hormones including, but probably not limited to, glucagon-like peptide-1 and peptide-YY. The increased secretion is due to an accelerated exposure to and absorption of nutrients in the small intestine. This places the weight loss and the gut hormones in key positions with respect to the metabolic improvements after bypass surgery. Topics: Appetite; Bariatric Surgery; Diabetes Mellitus, Type 2; Dietary Carbohydrates; Dietary Proteins; Digestion; Eating; Gastric Bypass; Gastrointestinal Hormones; Glucagon-Like Peptide 1; Humans; Insulin Resistance; Intestinal Absorption; Nutrients; Obesity, Morbid; Peptide YY; Weight Loss | 2018 |
The Impacts of Gastroileostomy Rat Model on Glucagon-like Peptide-1: a Promising Model to Control Type 2 Diabetes Mellitus.
One of the new current treatment options for Diabetes Mellitus is about increasing glucagon-like peptide-1 (GLP-1) activity. GLP-1 with its incretin effect showed major role in glucose homeostasis. Gastroileostomy can increase GLP-1 secretion by rapid delivery of undigested food to the terminal ileum. We studied the early effects of a gastroileostomy on serum levels of GLP-1, glucose, and insulin in rats.. Gastroileostomies with side-to-side anastomosis were performed on 15 male New Zealand rats. Blood samples were obtained before and 1 week after the gastroileostomy.. Our results showed that the rats lost a lot of weight from start (330 ± 15 g) to the end (240 ± 25 g) of the experiment (p = 0.048). The data analysis showed that the gastroileostomy surgery elevates the level of GLP-1in plasma significantly (89.1852 vs. 177.440 respectively; p < 0.001) and caused a significant decrease in plasma glucose as well (92.00 and 66.29 mg/dL respectively; p < 0.001). However, the insulin state elevated after the surgery significantly (8.03 vs. 9.89; p < 0.001).. In this study, we showed the effectiveness of gastroileostomy treatment to decrease body weight and plasma glucose with increased GLP-1 in rats. This small rat model suggests the potential of this surgery to treat type 2 diabetes mellitus. Topics: Animals; Blood Glucose; Combined Modality Therapy; Diabetes Mellitus, Experimental; Diabetes Mellitus, Type 2; Disease Models, Animal; Gastric Bypass; Glucagon-Like Peptide 1; Ileostomy; Incretins; Insulin; Male; Rats | 2018 |
Lithocholic Acid-Based Peptide Delivery System for an Enhanced Pharmacological and Pharmacokinetic Profile of Xenopus GLP-1 Analogs.
GLP-1 analogs suffer from the main disadvantage of a short in vivo half-life. Lithocholic acid (LCA), one of the four main bile acids in the human body, possesses a high albumin binding rate. We therefore envisioned that a LCA-based peptide delivery system could extend the half-life of GLP-1 analogs by facilitating the noncovalent binding of peptides to human serum albumin. On the basis of our previously identified Xenopus GLP-1 analogs (1-3), a series of LCA-modified Xenopus GLP-1 conjugates were designed (4a-4r), and the bioactivity studies of these conjugates were performed to identify compounds with balanced in vitro receptor activation potency and plasma stability. 4c, 4i, and 4r were selected, and their LCA side chains were optimized to further increase their stability, affording 5a-5c. Compound 5b showed a more increased albumin affinity and prolonged in vitro stability than that of 4i and liraglutide. In db/ db mice, 5b exhibited comparable hypoglycemic and insulinotropic activity to liraglutide and semaglutide. Importantly, the enhanced albumin affinity of 5b resulted in a prolonged in vivo antidiabetic duration. Finally, chronic treatment investigations of 5b demonstrated the therapeutic effects of 5b on HbA1c, body weight, blood glucose, and pancreatic endocrine deficiencies on db/ db mice. Our studies revealed 5b as a promising antidiabetic candidate. Furthermore, our study suggests the derivatization of Xenopus GLP-1 analogs with LCA represents an effective strategy to develop potent long-acting GLP-1 receptor agonists for the treatment of type 2 diabetes. Topics: Animals; Blood Glucose; Diabetes Mellitus, Experimental; Diabetes Mellitus, Type 2; Drug Evaluation, Preclinical; Drug Stability; Glucagon-Like Peptide 1; Glucagon-Like Peptides; Half-Life; HEK293 Cells; Humans; Hypoglycemic Agents; Liraglutide; Lithocholic Acid; Male; Mice; Mice, Inbred C57BL; Rats; Rats, Sprague-Dawley; Serum Albumin, Human; Treatment Outcome; Xenopus Proteins | 2018 |
Glucagon‑like peptide‑1 protects mouse podocytes against high glucose‑induced apoptosis, and suppresses reactive oxygen species production and proinflammatory cytokine secretion, through sirtuin 1 activation in vitro.
Glucagon‑like peptide‑1 (GLP‑1) is a gut incretin hormone that is considered to be a promising target for the treatment of patients with type 2 diabetes. However, the mechanisms underlying the protective effects of GLP‑1 on diabetic nephropathy are yet to be fully elucidated. Sirtuin (SIRT)1 encodes a member of the SIRT family of proteins that serves an important role in mitochondrial function and is reported to be associated with the pathogenesis of chronic kidney disease. The present study treated mouse podocytes with various concentrations of D‑glucose to establish a high glucose (HG)‑induced model of renal injury. The results of a 2',7'‑dichlorodihydrofluorescein diacetate assay, Annexin V/propidium iodide staining and ELISA demonstrated that treatment of podocytes with HG significantly enhanced the production of reactive oxygen species (ROS), promoted cell apoptosis and increased the secretion of proinflammatory cytokines, respectively. The cytokines increased following HG treatment included tumor necrosis factor‑α, interleukin (IL)‑1β and IL‑6. Notably, treatment with GLP‑1 attenuated HG‑induced increases in ROS production and podocyte apoptosis, which may occur via downregulation of the expression of caspase‑3 and caspase‑9, and increased expression of nephrin, podocin and SIRT1, as determined by reverse transcription‑quantitative polymerase chain reaction and western blot analysis. Treatment with GLP‑1 led to protective effects in podocytes that were similar to those of resveratrol. Furthermore, SIRT1 knockdown using short hairpin RNA significantly enhanced the expression of caspase‑3 and caspase‑9 in mouse podocytes, compared with normal mouse podocytes. SIRT1 knockdown with or without GLP‑1 administration significantly decreased the expression of caspase‑3 and caspase‑9 in mouse podocytes, compared with SIRT1 knockdown mouse podocytes. In conclusion, the results of the present study indicated that GLP‑1 may be a promising target for the development of novel therapeutic strategies for HG‑induced nephropathy, and may function through the activation of SIRT1. Topics: Acute Kidney Injury; Animals; Apoptosis; Cytokines; Diabetes Mellitus, Type 2; Diabetic Nephropathies; Gene Knockdown Techniques; Glucagon-Like Peptide 1; Glucose; Humans; Mice; Podocytes; Reactive Oxygen Species; Renal Insufficiency, Chronic; Sirtuin 1 | 2018 |
Takeda G Protein-Coupled Receptor 5-Mechanistic Target of Rapamycin Complex 1 Signaling Contributes to the Increment of Glucagon-Like Peptide-1 Production after Roux-en-Y Gastric Bypass.
The mechanism by which Roux-en-Y Gastric Bypass (RYGB) increases the secretion of glucagon-like peptide-1 (GLP-1) remains incompletely defined. Here we investigated whether TGR5-mTORC1 signaling mediates the RYGB-induced alteration in GLP-1 production in mice and human beings.. Circulating bile acids, TGR5-mTORC1 signaling, GLP-1 synthesis and secretion were determined in lean or obese male C57BL/6 mice with or without RYGB operation, as well as in normal glycemic subjects, obese patients with type 2 diabetes before and after RYGB.. Positive relationships were observed among circulating bile acids, ileal mechanistic target of rapamycin complex 1 (mTORC1) signaling and GLP-1 during changes in energy status in the present study. RYGB increased circulating bile acids, ileal Takeda G protein-coupled receptor 5 (TGR5) and mTORC1 signaling activity, as well as GLP-1 production in both mice and human subjects. Inhibition of ileal mTORC1 signaling by rapamycin significantly attenuated the stimulation of bile acid secretion, TGR5 expression and GLP-1 synthesis induced by RYGB in lean and diet-induced obese mice. GLP-1 production and ileal TGR5-mTORC1 signaling were positively correlated with plasma deoxycholic acid (DCA) in mice. Treatment of STC-1 cells with DCA stimulated the production of GLP-1. This effect was associated with a significant enhancement of TGR5-mTORC1 signaling. siRNA knockdown of mTORC1 or TGR5 abolished the enhancement of GLP-1 synthesis induced by DCA. DCA increased interaction between mTOR-regulatory-associated protein of mechanistic target of rapamycin (Raptor) and TGR5 in STC-1 cells.. Deoxycholic acid-TGR5-mTORC1 signaling contributes to the up-regulation of GLP-1 production after RYGB. Topics: Animals; Bile Acids and Salts; Blood Glucose; Deoxycholic Acid; Diabetes Mellitus, Type 2; Gastric Bypass; Gene Expression Regulation; Glucagon-Like Peptide 1; Humans; Insulin Resistance; Male; Mechanistic Target of Rapamycin Complex 1; Mice; Mice, Obese; Middle Aged; Obesity; Receptors, G-Protein-Coupled; Signal Transduction | 2018 |
The Clinical Impact of GLP-1 Receptor Agonists in Type 2 Diabetes: Focus on the Long-Acting Analogs.
GLP-1 receptor agonists (GLP-1 RAs), introduced for clinical use in 2005, have excellent potency in reducing HbA Topics: Blood Glucose; Diabetes Mellitus, Type 2; Drug Therapy, Combination; Exenatide; Glucagon-Like Peptide 1; Glucagon-Like Peptide-1 Receptor; Humans; Hypoglycemic Agents; Insulin, Long-Acting; Treatment Outcome | 2018 |
Farnesoid X Receptor (FXR) Interacts with Camp Response Element Binding Protein (CREB) to Modulate Glucagon-Like Peptide-1 (7-36) Amide (GLP-1) Secretion by Intestinal L Cell.
Type II diabetes is a complex, chronic, and progressive disease. Glucagon-like peptide-1 (7-6) amide (GLP-1) is a gut hormone released from the L cells which stimulates insulin secretion, and promotes insulin gene expression and β-cell growth and differentiation. Elevated levels of hormone secreted by L cells are an important reason for diabetes improvement. GLP-1 secretion has been reported to be regulated by farnesoid X receptor (FXR), a transcriptional sensor for bile acids which also acts on glucose metabolism. Herein, we attempted to evaluate the effect of FXR on GLP-1 secretion in mouse enteroendocrine L cell lines, STC-1 and GLUTag, and to investigate the underlying mechanism.. ELISA and Western blot assays were employed to examine the levels of GLP-1 and FXR, and the effect of FXR on GLP-1 secretion; online database, including BioGRID and KEGG were used to identify the potential interactions between FXR and proteins and involved pathways; GST pull-down and Co-Immunoprecipitation (Co-IP) assays were performed to validate FXR-CREB interaction; Luciferase reporter gene assays were used for CREB transcriptional activity determination.. FXR inversely regulated GLP-1 secretion in the mouse enteroendocrine L cell lines, GLUTag and STC-1. A total of 24 nonredundant human proteins were shown to be related to FXR by BioGRID; KEGG pathway analysis showed that FXR was related to glucagon signaling pathway, particularly with the transcriptional activators CREB, PGC1α, Sirt1 and CBP. CREB could positively regulate GLP-1 secretion in GLUTag and STC-1 cells. FXR combined with CREB to inhibit its transcriptional activity, thus inhibiting proprotein convertase subtilisin/ kexin type 1 (PCSK1) protein level and GLP-1 secretion.. In the present study, we demonstrated a negative regulation of GLP-1 secretion by FXR in L cell lines, GLUTag and STC-1; FXR exerts its function in L cells through interacting with CREB, a crucial transcriptional regulator of cAMP-CREB signaling pathway, to inhibit its transcriptional activity. Targeting FXR to rescue GLP-1 secretion may be a promising strategy for type II diabetes. Topics: Animals; CREB-Binding Protein; Diabetes Mellitus, Type 2; Enteroendocrine Cells; Glucagon-Like Peptide 1; L Cells; Mice; Peptide Fragments; Receptors, Cytoplasmic and Nuclear | 2018 |
Agonism of receptors in the gut-pancreas axis in type 2 diabetes: are two better than one?
Topics: Diabetes Mellitus, Type 2; Double-Blind Method; Glucagon; Glucagon-Like Peptide 1; Humans; Obesity; Overweight; Peptides; Receptors, Glucagon | 2018 |
Venous blood provides lower glucagon-like peptide-1 concentrations than arterialized blood in the postprandial but not the fasted state: Consequences of sampling methods.
What is the central question of this study? Glucagon-like peptide-1 (GLP-1) is an important obesity/diabetes target, with effects dependent on circulating GLP-1 concentrations. Peripheral tissues extract GLP-1; therefore, sampling venous versus arterialized blood might provide different GLP-1 concentrations. This study examined whether arterialization alters GLP-1 concentrations during fasting and feeding. What is the main finding and its importance? This study demonstrates that venous blood provides lower postprandial but not fasting GLP-1 concentrations versus arterialized blood. Therefore, when accurate assessment of postprandial peripheral availability of GLP-1 is required, blood sampling methods should be considered carefully, reported clearly, and arterialization is recommended.. Glucagon-like peptide-1 (GLP-1) displays concentration-dependent effects on metabolism, appetite and angiogenesis; therefore, accurate determination of circulating GLP-1 concentrations is important. In this study, we compared GLP-1 concentrations in venous versus arterialized blood in both fasted and fed conditions. Venous and arterialized blood samples were obtained simultaneously from 10 young, healthy men before and 30, 60 and 120 min after ingestion of 75 g glucose. Plasma GLP-1 concentrations increased in response to glucose ingestion (time effect, P < 0.01) and to a lesser extent in venous versus arterialized plasma (time × arterialization interaction, P < 0.01). Accordingly, the plasma incremental area under the curve was lower in venous versus arterialized plasma (974 ± 88 versus 1214 ± 115 pmol l (120 min) Topics: Adult; Arteries; Blood Specimen Collection; Diabetes Mellitus, Type 2; Fasting; Glucagon-Like Peptide 1; Glucose; Glucose Tolerance Test; Humans; Insulin; Male; Postprandial Period; Veins; Young Adult | 2018 |
Prevalence and factors associated with nonalcoholic fatty pancreas disease and its severity in China.
Pancreatic lipidosis (nonalcoholic fatty pancreas disease, NAFPD) causes insulin resistance and dysfunction of pancreatic β-cells, with the risk of type 2 diabetes mellitus (T2DM). However, the prevalence and pathogenic factors associated with NAFPD are not clear. The aim of the study was to explore the prevalence of NAFPD in a Chinese adult population, and investigate factors associated with NAFPD aggravation.This was a cross-sectional study; 4419 subjects were enrolled for NAFPD screening and were divided into NAFPD (n = 488) and without NAFPD (n = 3930) groups. The sex, age, related concomitant diseases, general physical parameters, and serum glucose and lipid metabolism were compared between the 2 groups.The overall NAFPD prevalence was 11.05%, but increased with age. In those <55 years NAFPD prevalence was lower in females than males (P < .05), but prevalence was similar >55 years. Nonalcoholic fatty liver disease (NAFLD), T2DM, homeostasis model assessment-insulin resistance index, total cholesterol, triglyceride, lipoprotein, adiponectin, and glucagon-like peptide 1 (GLP-1) were the independent risk factors for NAFPD (P < .05). Analaysis of mild NAFPD (MN) and severe NAFPD (SN) subgroups, according to the extent of fat deposition, suggested that NAFLD, triglyceride, lipoprotein, and adiponectin were independent risk factors for NAFPD aggravation (P < .05).The NAFPD prevalence was about 11% in Chinese adults. Its development and progression was related to NAFLD, T2DM, insulin resistance, dyslipidemia, and GLP-1 levels. Severe NAFPD was associated with NAFLD and dyslipidemia. Topics: Adiponectin; Adult; Age Factors; China; Comorbidity; Cross-Sectional Studies; Diabetes Mellitus, Type 2; Dyslipidemias; Female; Glucagon-Like Peptide 1; Humans; Hypertension; Insulin Resistance; Lipoproteins; Male; Middle Aged; Overweight; Pancreatic Diseases; Prevalence; Risk Factors; Sex Factors; Triglycerides | 2018 |
Review: In type 2 diabetes, SGLT-2 inhibitors or GLP-1 agonists reduce mortality vs control or DPP-4 inhibitors.
Topics: Diabetes Mellitus, Type 2; Dipeptidyl-Peptidase IV Inhibitors; Glucagon-Like Peptide 1; Glucose; Humans; Hypoglycemic Agents; Sodium; Sodium-Glucose Transporter 2 Inhibitors | 2018 |
Lipidation and conformational constraining for prolonging the effects of peptides: Xenopus glucagon-like peptide 1 analogues with potent and long-acting hypoglycemic activity.
Topics: Animals; Delayed-Action Preparations; Diabetes Mellitus, Type 2; Glucagon-Like Peptide 1; HEK293 Cells; Humans; Hypoglycemic Agents; Lipids; Male; Mice, Inbred C57BL; Molecular Conformation; Rats, Sprague-Dawley; Structure-Activity Relationship; Xenopus Proteins | 2018 |
Rational design of dimeric lipidated Xenopus glucagon-like peptide 1 analogues as long-acting antihyperglycaemic agents.
Dimerization is viewed as an effective means to enhance the binding affinity and therapeutic potency of peptides. Both dimerization and lipidation effectively prolong the half-life of peptides in vivo by increasing hydrodynamic size and facilitating physical interactions with serum albumin. Here, we report a novel method to discover long-acting glucagon-like peptide 1 (GLP-1) analogues by rational design based on Xenopus GLP-1 through a combined dimerization and lipidization strategy. On the basis of our previous structure analysis of Xenopus GLP-1, palmitic acid and a C-terminal Cys were firstly introduced into two Xenopus GLP-1 analogues (1 and 2), and the afforded 3 and 4 were further reacted with bis-maleimide amine to afford two dimeric lipidated Xenopus GLP-1 analogues (5 and 6). The in vitro and in vivo biological activities of 5 and 6 were significantly improved as compared with their monomers. Moreover, the selected compound 6 showed greater hypoglycemic and insulinotropic activities than liraglutide even when the dose of 6 was reduced to half in db/db mice. Pharmacokinetic test revealed that 6 had a ∼ 3-fold longer half-life than liraglutide in Kunming mice and SD rats, and the longer half-life of 6 led to excellent long-acting hypoglycemic effects as confirmed by two different pharmacological methods conducted on db/db mice. Finally, a 7 weeks chronic study conducted on db/db mice demonstrated the better therapeutic efficacies of 6 on glucose tolerance normalization, HbA1c reduction and pancreas islets protection than liraglutide. The present research showed that combined dimerization and lipidization is effective when applied to Xenopus GLP-1 analogue to develop novel GLP-1 analogue for the treatment of type 2 diabetes. In addition, the promising preclinical data of 6 suggested the therapeutic potential of 6 as a novel anti-diabetic agent. Topics: Animals; Diabetes Mellitus, Experimental; Diabetes Mellitus, Type 2; Dose-Response Relationship, Drug; Drug Design; Glucagon-Like Peptide 1; Glucose Tolerance Test; Hypoglycemic Agents; Male; Mice; Mice, Inbred C57BL; Mice, Inbred Strains; Mice, Mutant Strains; Molecular Structure; Obesity; Rats; Rats, Sprague-Dawley; Structure-Activity Relationship; Xenopus | 2018 |
Association Between Sodium-Glucose Cotransporter 2 Inhibitors and Lower Extremity Amputation Among Patients With Type 2 Diabetes.
Results of clinical trials suggest that canagliflozin, a sodium-glucose cotransporter 2 (SGLT-2) inhibitor for treating type 2 diabetes, may be associated with lower extremity amputation.. To quantify the association between the use of oral medication for type 2 diabetes and 5 outcomes (lower extremity amputation, peripheral arterial disease, critical limb ischemia, osteomyelitis, and ulcer).. A retrospective cohort study was conducted using Truven Health MarketScan Commercial Claims and Encounters data on new users between September 1, 2012, and September 30, 2015. The study focused on 2.0 million commercially insured individuals and used propensity score weighting to balance baseline differences among groups. Sensitivity analyses varied statistical models, assessed the effect of combining dipeptidyl peptidase 4 (DPP-4) inhibitors and glucagon-like peptide 1 (GLP-1) agonists as a single referent group, adjusted for baseline use of older oral agents, and included people with baseline amputation.. New use of SGLT-2 inhibitors alone, DPP-4 inhibitors alone, GLP-1 agonists alone, or other antidiabetic agents (sulfonylurea, metformin hydrochloride, or thiazolidinediones).. Foot and leg amputation, defined by validated International Classification of Diseases, Ninth Revision and Current Procedural Terminology codes.. Among 2.0 million potentially eligible individuals, a total of 953 906 (516 046 women and 437 860 men; mean [SD] age, 51.8 [10.9] years) were included in the final analyses, including 39 869 new users of SGLT-2 inhibitors (4.2%), 105 023 new users of DPP-4 inhibitors (11.0%), and 39 120 new users of GLP-1 agonists (4.1%). The median observation time ranged from 99 days for new users of GLP-1 agonists to 127 days for those using metformin, sulfonylureas, and thiazolidinediones, while the crude incident rates ranged from 4.90 per 10 000 person-years for those using metformin, sulfonylureas, and thiazolidinediones to 10.53 per 10 000 person-years for new users of SGLT-2 inhibitors. After propensity score weighting and adjustment for demographics, severity of diabetes, comorbidities, and medications, there was a nonstatistically significant increased risk of amputation associated with new use of SGLT-2 inhibitors compared with DPP-4 inhibitors (adjusted hazard ratio, 1.50; 95% CI, 0.85-2.67) and GLP-1 agonists (adjusted hazard ratio, 1.47; 95% CI, 0.64-3.36). New use of SGLT-2 inhibitors was statistically significantly associated with amputation compared with sulfonylureas, metformin, or thiazolidinediones (adjusted hazard ratio, 2.12; 95% CI, 1.19-3.77). These results persisted in sensitivity analyses.. Use of SGLT-2 inhibitors may be associated with increased risk of amputation compared with some oral treatments for type 2 diabetes. Further observational studies are needed with extended follow-up and larger sample sizes. Topics: Amputation, Surgical; Blood Glucose; Canagliflozin; Diabetes Mellitus, Type 2; Dipeptidyl-Peptidase IV Inhibitors; Drug Therapy, Combination; Female; Follow-Up Studies; Glucagon-Like Peptide 1; Humans; Incidence; Lower Extremity; Male; Middle Aged; Peripheral Arterial Disease; Population Surveillance; Propensity Score; Retrospective Studies; Sodium-Glucose Transporter 2 Inhibitors; United States | 2018 |
Mixed Meal and Intravenous L-Arginine Tests Both Stimulate Incretin Release Across Glucose Tolerance in Man: Lack of Correlation with β Cell Function.
The aims of this study were to 1. define the responses of glucagon-like peptide-1 (GLP-1), glucose-dependent insulinotropic polypeptide (GIP), glucagon, and peptide YY (PYY) to an oral meal and to intravenous L-arginine; and 2. examine correlation of enteroendocrine hormones with insulin secretion. We hypothesized a relationship between circulating incretin concentrations and insulin secretion.. Subjects with normal glucose tolerance (NGT, n = 23), prediabetes (PDM, n = 17), or with type 2 diabetes (T2DM, n = 22) were studied twice, following a mixed test meal (470 kCal) (mixed meal tolerance test [MMTT]) or intravenous L-arginine (arginine maximal stimulation test [AST], 5 g). GLP-1 (total and active), PYY, GIP, glucagon, and β cell function were measured before and following each stimulus.. Baseline enteroendocrine hormones differed across the glucose tolerance (GT) spectrum, T2DM generally >NGT and PDM. In response to MMTT, total and active GLP-1, GIP, glucagon, and PYY increased in all populations. The incremental area-under-the-curve (0-120 min) of analytes like total GLP-1 were often higher in T2DM compared with NGT and PDM (35-51%; P < 0.05). At baseline glucose, L-arginine increased total and active GLP-1 and glucagon concentrations in all GT populations (all P < 0.05). As expected, the MMTT and AST provoked differential glucose, insulin, and C-peptide responses across GT populations. Baseline or stimulated enteroendocrine hormone concentrations did not consistently correlate with either measure of β cell function.. Both MMTT and AST resulted in insulin and enteroendocrine hormone responses across GT populations without consistent correlation between release of incretins and insulin, which is in line with other published research. If a defect is in the enteroendocrine/β cell axis, it is probably reduced response to rather than diminished secretion of enteroendocrine hormones. Topics: Administration, Intravenous; Arginine; Biomarkers; Blood Glucose; Cross-Sectional Studies; Diabetes Mellitus, Type 2; Eating; Enteroendocrine Cells; Gastric Inhibitory Polypeptide; Gastrointestinal Hormones; Glucagon; Glucagon-Like Peptide 1; Humans; Insulin; Insulin-Secreting Cells; Peptide YY; Postprandial Period; Prediabetic State; Time Factors; United States | 2018 |
Intestinal bitter taste receptor activation alters hormone secretion and imparts metabolic benefits.
Extracts of the hops plant have been shown to reduce weight and insulin resistance in rodents and humans, but elucidation of the mechanisms responsible for these benefits has been hindered by the use of heterogeneous hops-derived mixtures. Because hop extracts are used as flavoring agents for their bitter properties, we hypothesized that bitter taste receptors (Tas2rs) could be mediating their beneficial effects in metabolic disease. Studies have shown that exposure of cultured enteroendocrine cells to bitter tastants can stimulate release of hormones, including glucagon-like peptide 1 (GLP-1). These findings have led to the suggestion that activation of Tas2rs may be of benefit in diabetes, but this tenet has not been tested. Here, we have assessed the ability of a pure derivative of a hops isohumulone with anti-diabetic properties, KDT501, to signal through Tas2rs. We have further used this compound as a tool to systematically assess the impact of bitter taste receptor activation in obesity-diabetes.. KDT501 was tested in a panel of bitter taste receptor signaling assays. Diet-induced obese mice (DIO) were dosed orally with KDT501 and acute effects on glucose homeostasis determined. A wide range of metabolic parameters were evaluated in DIO mice chronically treated with KDT501 to establish the full impact of activating gut bitter taste signaling.. We show that KDT501 signals through Tas2r108, one of 35 mouse Tas2rs. In DIO mice, acute treatment stimulated GLP-1 secretion and enhanced glucose tolerance. Chronic treatment caused weight and fat mass loss, increased energy expenditure, enhanced glucose tolerance and insulin sensitivity, normalized plasma lipids, and induced broad suppression of inflammatory markers. Chronic KDT501 treatment altered enteroendocrine hormone levels and bile acid homeostasis and stimulated sustained GLP-1 release. Combined treatment with a dipeptidyl peptidase IV inhibitor amplified the incretin-based benefits of this pure isohumulone.. Activation of Tas2r108 in the gut results in a remodeling of enteroendocrine hormone release and bile acid metabolism that ameliorates multiple features of metabolic syndrome. Targeting extraoral bitter taste receptors may be useful in metabolic disease. Topics: Animals; Body Weight; Cyclopentanes; Diabetes Mellitus, Type 2; Disease Models, Animal; Enteroendocrine Cells; Glucagon-Like Peptide 1; Humulus; Hypoglycemic Agents; Insulin Resistance; Intestinal Mucosa; Intestines; Male; Mice; Mice, Inbred C57BL; Mice, Obese; Receptors, G-Protein-Coupled; Signal Transduction | 2018 |
Oral GLP-1 Analog for Type 2 Diabetes on the Horizon.
Topics: Administration, Oral; Diabetes Mellitus, Type 2; Glucagon-Like Peptide 1; Glucagon-Like Peptides; Humans; Hypoglycemic Agents | 2018 |
Semaglutide and GLP-1 analogues as weight-loss agents.
Topics: Anti-Obesity Agents; Diabetes Mellitus, Type 2; Glucagon-Like Peptide 1; Glucagon-Like Peptides; Hypoglycemic Agents | 2018 |
The effect of distal-ileal exclusion after Roux-en-Y gastric bypass on glucose tolerance and GLP-1 response in type-2 diabetes Sprague-Dawley rat model.
An increase in glucagon-like peptide-1 (GLP-1) mediating early diabetes remission after Roux-en-Y gastric bypass (RYGB) is believed to be associated with distal-ileal stimulation.. To observe the effect of distal-ileal exclusion on glucose tolerance and GLP-1 response after RYGB.. Affiliated Hospital of Xuzhou Medical University, Xuzhou, Jiangsu, China.. A type 2 diabetes model was created in 40 Sprague-Dawley rats that were randomly assigned to a RYGB group (n = 32) and a sham group (n = 8). Four weeks after surgery, the RYGB group was further divided into the RYGB control group (n = 8) and the distal-ileal exclusion group (RYGB-IEx, n = 24). Rats in the RYGB-IEx group underwent laparotomy, and the last 20 cm of ileum was excluded. An oral glucose tolerance test, insulin tolerance test, and mixed-meal tolerance test conducted preoperatively were repeated in all groups at 4 and 8 weeks postoperatively.. Compared with preoperative level, GLP-1 was significantly increased after RYGB. GLP-1 area under the curve recorded after oral gavage at week 4 postoperatively was significantly higher than the preoperative level (P < .05). GLP-1, insulin area under the curve, and improved glucose-excursion on oral glucose tolerance test 4 weeks after gastric bypass were not reversed at week 8 after distal-ileal exclusion in the RYGB-IEx group. Food intake increased significantly after distal-ileal exclusion in the RYGB-IEx group.. These findings suggest that distal-ileal stimulation might not be required for incretin response and diabetes remission after gastric bypass in the type 2 diabetes Sprague-Dawley rat model. Topics: Animals; Blood Glucose; Diabetes Mellitus, Experimental; Diabetes Mellitus, Type 2; Gastric Bypass; Glucagon-Like Peptide 1; Glucose; Glucose Tolerance Test; Ileum; Male; Postoperative Period; Random Allocation; Rats, Sprague-Dawley; Sweetening Agents | 2018 |
Introduction.
This supplement was funded by Novo Nordisk. McGill has received grants and personal fees from Novo Nordisk; grants from AstraZeneca, Novartis, Lexicon, and Pfizer; and personal fees from Intarcia, Boehringer-Ingelheim, Janssen, Mannkind, Bayer, and Merck. Topics: Diabetes Mellitus, Type 2; Glucagon-Like Peptide 1; Glucagon-Like Peptide-1 Receptor; Humans; Hypoglycemic Agents | 2018 |
Blackcurrant Extract Ameliorates Hyperglycemia in Type 2 Diabetic Mice in Association with Increased Basal Secretion of Glucagon-Like Peptide-1 and Activation of AMP-Activated Protein Kinase.
Topics: AMP-Activated Protein Kinases; Animals; Cell Membrane; Diabetes Mellitus, Type 2; Dietary Supplements; Enzyme Activation; Enzyme Induction; Fruit; Glucagon-Like Peptide 1; Glucose Transporter Type 4; Hypoglycemic Agents; Ileum; Intestinal Mucosa; Isoenzymes; Male; Mice, Mutant Strains; Muscle, Skeletal; Plant Extracts; Proprotein Convertases; Protein Transport; Ribes; Specific Pathogen-Free Organisms | 2018 |
DS-8500a, an Orally Available G Protein-Coupled Receptor 119 Agonist, Upregulates Glucagon-Like Peptide-1 and Enhances Glucose-Dependent Insulin Secretion and Improves Glucose Homeostasis in Type 2 Diabetic Rats.
Topics: Animals; Benzamides; CHO Cells; Cricetulus; Cyclopropanes; Diabetes Mellitus, Experimental; Diabetes Mellitus, Type 2; Glucagon-Like Peptide 1; Glucose; Homeostasis; Humans; Hypoglycemic Agents; Insulin; Insulin Secretion; Insulin-Secreting Cells; Male; Mesylates; Mice; Oxadiazoles; Rats; Rats, Sprague-Dawley; Rats, Zucker; Receptors, G-Protein-Coupled; Tetrazoles; Thiazoles; Up-Regulation | 2018 |
Low glucagon-like peptide-1 (GLP-1) concentration in serum is indicative of mild cognitive impairment in type 2 diabetes patients.
To reveal potential association between glucagon-like peptide 1 (GLP-1) concentration in serum and mild cognitive function impairment (MCI) in type 2 diabetes mellitus (T2DM) patients.. A total of 106 T2DM patients and 47 normal controls were recruited in this study. Montreal Cognitive Assessment (MoCA) was performed in all subjects. Among the 106 patients, 52 presented with MCI. Fasting blood glucose (FBG), total cholesterol (TC), low-density cholesterol (LDL-C), high-density cholesterol (HDL-C), triglyceride (TG), uric acid (UA) and GLP-1 levels were also assessed in all subjects.. Patients with MCI had higher serum concentrations of FBG and TC and lower concentrations of GLP-1 and HDL-C than controls. Bivariate correlation analysis showed that MCI in T2DM patients closely correlated with FBG, HDL-C, and GLP-1 levels. Moreover, ordinal regression analysis showed that GLP-1 concentration in serum was protective for MCI in T2DM patients (OR = 0.025; 95%CI: 0.005-3.934).. Our results indicated that low concentration of GLP-1 may play a role in the pathogenesis of MCI in T2DM patients. Topics: Adult; Biomarkers; Cognitive Dysfunction; Diabetes Mellitus, Type 2; Female; Glucagon-Like Peptide 1; Humans; Hypertension; Hypoglycemic Agents; Male; Middle Aged; Risk Factors | 2018 |
HARMONY or discord in cardiovascular outcome trials of GLP-1 receptor agonists?
Topics: Cardiovascular Diseases; Diabetes Mellitus, Type 2; Double-Blind Method; Glucagon-Like Peptide 1; Glucagon-Like Peptide-1 Receptor; Humans | 2018 |
Glucagon-Like Peptide-1 Modulates Cholesterol Homeostasis by Suppressing the miR-19b-Induced Downregulation of ABCA1.
Abnormal regulation of cholesterol homeostasis is associated with type 2 diabetes mellitus (T2DM) and multiple other diseases. Glucagon-like peptide-1 (GLP-1) has unique effects on modulating hepatic lipid metabolism. However, the mechanism behind these is largely unknown. The aim of this study was to investigate the effects of GLP-1 on cholesterol-induced lipotoxicity in hepatocytes and examine the underlying mechanisms.. Cell viability was determined by CCK-8. Caspase-3 detection was used to assess the effects of GLP-1 on cholesterol-induced apoptosis. TNF-α and IL-6 as the inflammatory markers were measured by ELISA. The alterations of miR-19b and ATP-binding cassette transporter A1 (ABCA1) resulting from high-fat diet/cholesterol incubation or GLP-1 were detected by real-time PCR and western blot.. GLP-1 markedly up-regulated the expression of ABCA1 protein, but didn't affect peroxisome proliferator-activated receptor α (PPAR-α) protein. The miR-19b levels were significantly down-regulated in GLP-1-treated groups. The inhibition and overexpression of miR-19b were established to explore the effects of a GLP-1-mediated alteration in miR-19b. Cholesterol transport assays revealed that treatment with GLP-1 alone or together with miR-19b inhibitor significantly enhanced ABCA1-dependent cholesterol efflux, resulting in reduced total cholesterol. Further, histological examination was used to detect lipid accumulation. Cholesterol significantly attenuated cell viability, promoted hepatic cell apoptosis, and facilitated lipid accumulation, and these effects could be reversed by GLP-1.. GLP-1 may affect cholesterol homeostasis by regulating the expression of miR-19b and ABCA1. Topics: Animals; Antagomirs; Apoptosis; ATP Binding Cassette Transporter 1; Cholesterol; Diabetes Mellitus, Type 2; Diet, High-Fat; Down-Regulation; Glucagon-Like Peptide 1; Hep G2 Cells; Humans; Lipid Metabolism; Liver; Male; MicroRNAs; PPAR alpha; Rats; Rats, Sprague-Dawley; Tumor Necrosis Factor-alpha | 2018 |
Cardiovascular benefit of albiglutide.
Topics: Cardiovascular Diseases; Diabetes Mellitus, Type 2; Double-Blind Method; Glucagon-Like Peptide 1; Humans | 2018 |
Management of Diabetes Mellitus With Glucagonlike Peptide-1 Agonist Liraglutide in Renal Transplant Recipients: A Retrospective Study.
Diabetes mellitus (DM) is the major cause of end-stage renal disease (ESRD) in Taiwan. Despite the use of steroids and/or calcineurin inhibitors (CNIs) in renal transplantation (RTx), additional challenges occur when a patient displays persisting metabolic disease, carries on an unhealthy lifestyle, or experiences genetic effects. Although RTx recipients could get better glycemic control by oral anti-diabetic drugs (OADs) or several insulin agents, they still need more than two kinds of medication. Liraglutide, a GLP-1 receptor agonist, stimulates insulin secretion and inhibits glucagon secretion and hepatic glucose production in a glucose-dependent manner. In addition, it delays gastric emptying and suppresses appetite through the central pathways. Herein we report on the long-term benefits of liraglutide in the management of DM in RTx recipients.. We retrospectively retrieved 7 RTx patients in August 2015, who had been prescribed liraglutide due to their poor glycemic control; however, 2 of them discontinued their scheduled doses within 1 month. The mean follow-up period was 19.4 ± 7.6 (range 10.5-27.6) months.. Liraglutide may be safe and effective for RTx recipients with poor diabetic glycemic control, although there have been incidences of intolerance in some patients, and potential concern regarding absorption of oral medications due to a delay of gastric emptying. Evidence of liraglutide in diabetic RTx recipients is limited, so additional prospective clinical studies should be undertaken in the future. Topics: Diabetes Mellitus, Type 2; Female; Glucagon-Like Peptide 1; Humans; Hypoglycemic Agents; Kidney Transplantation; Liraglutide; Male; Middle Aged; Prospective Studies; Retrospective Studies; Taiwan | 2018 |
"Let's Stay Together"; GIP and GLP-1 dual agonism in the treatment of metabolic disease.
Topics: Diabetes Mellitus, Type 2; Glucagon-Like Peptide 1; Glucagon-Like Peptide-1 Receptor; Humans; Incretins; Metabolic Diseases | 2018 |
Clinical inertia among patients with type 2 diabetes mellitus treated with DPP-4i and/or SGLT-2i.
Failure to intensify treatment of patients with type 2 diabetes (T2D) in a timely manner is a common challenge. If newer oral anti-diabetic drugs (NOADs) such as dipeptidyl peptidase-4 inhibitors (DPP-4i) and sodium/glucose cotransporter 2 inhibitors (SGLT-2i) do not achieve metabolic control, injectable therapy like insulin or glucagon-like Peptide 1 (GLP-1) receptor agonists are required. We investigated the time in poor glycaemic control (PC, HbA1c > 7%, >7.5%, >8%) in adults with T2D treated with DPP-4i/SGLT-2i until treatment intensification with insulin/GLP-1 or until the most recent documented visit.. T2D ≥ 18 years were identified from the diabetes patient follow-up registry (DPV), which captures data from diabetes specialist care. Patients with ≥2 documented visits with DPP-4i/SGLT-2i treatment and with the most recent treatment year ≥2015 were included.. The study population consisted of 4576 patients treated with DPP-4i/SGLT-2i. A subgroup of 1416 patients were intensified with an injectable therapy. Mean time in PC until intensification with insulin/GLP-1 was 16.7 months (HbA1c > 7%), 15.7 and 15.1 months (HbA1c > 7.5%, HbA1c > 8%) in this subgroup, respectively. Mean time in PC until most recent visit was 12.6, 9.9 and 8.4 months in the subgroup of patients without treatment intensification.. Even with NOADs, a substantial proportion of T2D do not achieve good metabolic control. These findings may be due to individualized target setting for HbA1c, or reluctance of patients and physicians towards injectable therapy. Effective diabetes management strategies are necessary to reduce the risk of adverse outcomes and to increase quality of life in T2D. Topics: Aged; Diabetes Mellitus, Type 2; Dipeptidyl-Peptidase IV Inhibitors; Female; Glucagon-Like Peptide 1; Humans; Hypoglycemic Agents; Male | 2018 |
Engineering of a GLP-1 analogue peptide/anti-PCSK9 antibody fusion for type 2 diabetes treatment.
Type 2 diabetes (T2D) is a complex and progressive disease requiring polypharmacy to manage hyperglycaemia and cardiovascular risk factors. However, most patients do not achieve combined treatment goals. To address this therapeutic gap, we have developed MEDI4166, a novel glucagon-like peptide-1 (GLP-1) receptor agonist peptide fused to a proprotein convertase subtilisin/kexin type 9 (PCSK9) neutralising antibody that allows for glycaemic control and low-density lipoprotein cholesterol (LDL-C) lowering in a single molecule. The fusion has been engineered to deliver sustained peptide activity in vivo in combination with reduced potency, to manage GLP-1 driven adverse effects at high dose, and a favourable manufacturability profile. MEDI4166 showed robust and sustained LDL-C lowering in cynomolgus monkeys and exhibited the anticipated GLP-1 effects in T2D mouse models. We believe MEDI4166 is a novel molecule combining long acting agonist peptide and neutralising antibody activities to deliver a unique pharmacology profile for the management of T2D. Topics: Animals; Antibodies, Monoclonal; CHO Cells; Cricetulus; Diabetes Mellitus, Experimental; Diabetes Mellitus, Type 2; Glucagon-Like Peptide 1; Hep G2 Cells; Humans; Hypoglycemic Agents; Macaca fascicularis; Male; Mice; PCSK9 Inhibitors; Recombinant Fusion Proteins | 2018 |
Creation of Straight-Chain Cationic Polysaccharide-Based Bile Salt Sequestrants Made from Euglenoid β-1,3-Glucan as Potential Antidiabetic Agents.
Straight-chain polysaccharides have a greater potential of selectively adsorbing hydrophobic bile salts than resin-based bile salt sequesters because of ionic and hydrophobic interactions; hence, they may possess antidiabetic activity. The feasibility of using cationic polysaccharides made from euglenoid β-1,3-glucan (referred to as paramylon) as potential antidiabetic agents was examined by using in vitro and animal experiments.. Cationic straight-chain polysaccharides were synthesized from euglenoid polysaccharide and glycidyltrimethylammonium chloride. The effects of administration of the synthetic polysaccharide on metabolic syndrome-related indicators were examined in high-fat diet-induced obesity mice. The degree of adsorption of bile salts by the polysaccharides was evaluated using spectroscopic analysis.. Administration of the cationic paramylon derivatives significantly reduced body and mesenteric fat weight in high-fat diet-induced obesity mice. A noteworthy effect was that glucagon-like peptide-1 (GLP-1) secretion was approximately three times higher in diet-induced obesity mice receiving cationic paramylon derivatives than in those receiving cellulose as a control.. Our results indicate that these cationic paramylon derivatives are potential GLP-1 secretagogues suitable for further study. Topics: Abdominal Fat; Animals; Bile Acids and Salts; Body Weight; Diabetes Mellitus, Type 2; Diet, High-Fat; Energy Intake; Feces; Glucagon-Like Peptide 1; Glucans; Hypoglycemic Agents; Mice; Mice, Inbred C57BL | 2018 |
GLP1 Receptor Agonist Liraglutide Is an Effective Therapeutic Option for Perioperative Glycemic Control in Type 2 Diabetes within Enhanced Recovery After Surgery (ERAS) Protocols.
Enhanced Recovery After Surgery (ERAS) protocols are multimodal perioperative care pathways designed to achieve early recovery after surgical procedures by maintaining preoperative organ function and reducing profound stress responses following surgery [Wilmore and Kehlet: BMJ 2001; 322(7284): 473-6]. Glucagon-like peptide-1 receptor agonists (GLP-1RAgs), such as liraglutide, have recently been widely used as antidiabetic agents in patients with type 2 diabetes (T2D) because they maintain blood glucose at an ideal level throughout the day, including during postprandial periods, thereby improving hypoglycemia and body weight more than insulin therapies. Additionally, the administration of liraglutide may exert cardiovascular, renal, and cerebral protective effects in T2D patients. The use of GLP-1RAgs for perioperative glycemic control is sometimes considered to be controversial.. The efficacy and safety of liraglutide therapy during perioperative glycemic control in elective surgery patients within ERAS protocols were compared with those of insulin therapy. Ninety adult T2D patients scheduled to undergo elective surgery within ERAS protocols were randomized and analyzed. Forty-nine subjects were prescribed liraglutide and 41 insulin therapy. Procedures comprised orthopedic, thoracic, urological, otolaryngological, hepatic resection, and gynecological breast surgeries.. Liraglutide was shown to be a more effective option than insulin therapy because (1) glycemic levels were more stable; (2) the number of patients requiring additional insulin according to the insulin sliding scale was significantly smaller (Fisher's exact test, p = 0.005); (3) the insulin dosage required on the day of surgery was significantly smaller (Fisher's exact, p = 0.004); (4) the additional insulin volume required was significantly less for patients throughout the perioperative period (Fisher's exact test, p = 0.001); and (5) while lean body mass remained the same, body fat measurements, particularly visceral fat, tended to decrease.. Based on the results of the present study and a recent large-scale clinical study showing cardiovascular and renal protective effects in T2D patients, we consider the administration of liraglutide within ERAS protocols for T2D patients to represent a more comprehensive suite of patient protection measures as a perioperative non-insulin agent, particularly in patients with limited exercise ability and those at risk of hypoglycemia. Topics: Aged; Aged, 80 and over; Blood Glucose; Clinical Protocols; Diabetes Mellitus, Type 2; Female; Glucagon-Like Peptide 1; Humans; Liraglutide; Male; Middle Aged; Perioperative Care; Postoperative Complications; Recovery of Function | 2018 |
Association of Second-line Antidiabetic Medications With Cardiovascular Events Among Insured Adults With Type 2 Diabetes.
Understanding cardiovascular outcomes of initiating second-line antidiabetic medications (ADMs) may help inform treatment decisions after metformin alone is not sufficient or not tolerated. To date, no studies have compared the cardiovascular effects of all major second-line ADMs during this early decision point in the pharmacologic management of type 2 diabetes.. To examine the association of second-line ADM classes with major adverse cardiovascular events.. Retrospective cohort study among 132 737 insured adults with type 2 diabetes who started therapy with a second-line ADM after taking either metformin alone or no prior ADM. This study used 2011-2015 US nationwide administrative claims data. Data analysis was performed from January 2017 to October 2018.. Dipeptidyl peptidase 4 (DPP-4) inhibitors, glucagon-like peptide-1 (GLP-1) receptor agonists, sodium-glucose cotransporter 2 (SGLT-2) inhibitors, thiazolidinediones (TZDs), basal insulin, and sulfonylureas or meglitinides (both referred to as sulfonylureas hereafter). The DPP-4 inhibitors served as the comparison group in all analyses.. The primary outcome was time to first cardiovascular event after starting the second-line ADM. This composite outcome was based on hospitalization for the following cardiovascular conditions: congestive heart failure, stroke, ischemic heart disease, or peripheral artery disease.. Among 132 737 insured adult patients with type 2 diabetes (men, 55%; aged 45-64 years, 58%; white, 63%), there were 3480 incident cardiovascular events during 169 384 person-years of follow-up. Patients were censored after the first cardiovascular event, discontinuation of insurance coverage, transition from International Classification of Diseases, Ninth Revision (ICD-9) to end of ICD-9 coding, or 2 years of follow-up. After adjusting for patient, prescriber, and health plan characteristics, the risk of composite cardiovascular events after starting GLP-1 receptor agonists was lower than DPP-4 inhibitors (hazard ratio [HR], 0.78; 95% CI, 0.63-0.96), but this finding was not significant in all sensitivity analyses. Cardiovascular event rates after starting treatment with SGLT-2 inhibitors (HR, 0.81; 95% CI, 0.57-1.53) and TZDs (HR, 0.92; 95% CI, 0.76-1.11) were not statistically different from DPP-4 inhibitors. The comparative risk of cardiovascular events was higher after starting treatment with sulfonylureas (HR, 1.36; 95% CI, 1.23-1.49) or basal insulin (HR, 2.03; 95% CI, 1.81-2.27) than DPP-4 inhibitors.. Among insured adult patients with type 2 diabetes initiating second-line ADM therapy, the short-term cardiovascular outcomes of GLP-1 receptor agonists, SGLT-2 inhibitors, and DPP-4 inhibitors were similar. Higher cardiovascular risk was associated with use of sulfonylureas or basal insulin compared with newer ADM classes. Clinicians may consider prescribing GLP-1 receptor agonists, SGLT-2 inhibitors, or DPP-4 inhibitors more routinely after metformin rather than sulfonylureas or basal insulin. Topics: Aged; Cardiovascular Diseases; Diabetes Mellitus, Type 2; Dipeptidyl-Peptidase IV Inhibitors; Female; Glucagon-Like Peptide 1; Humans; Hypoglycemic Agents; Male; Middle Aged; Retrospective Studies; Risk Factors; Sodium-Glucose Transporter 2 Inhibitors; Sulfonylurea Compounds | 2018 |
Improvement in glucose tolerance and insulin sensitivity by probiotic strains of Indian gut origin in high-fat diet-fed C57BL/6J mice.
Diabetes and obesity are characterized by glucose intolerance, fat deposition, inflammation, and dyslipidemia. Recent reports postulated that distinct gut microbiota alterations were observed in obese/diabetic subjects and modulating gut microbiota beneficially through specific probiotics could be a potential therapeutic option for type 2 diabetes/obesity. Therefore, we attempted to study the efficacy of probiotics of Indian gut origin (Lactobacillus plantarum MTCC5690 and Lactobacillus fermentum MTCC5689) along with a positive control, Lactobacillus rhamnosus (LGG) on glucose/lipid homeostasis in high-fat-diet-induced diabetic animal model.. C57BL/6J male mice were divided into seven groups (n = 6 per group) comprising feeding on: (1) Normal Pellet Diet (NPD), (2) High-Fat Diet (HFD), (3) HFD with LGG, (4) HFD with MTCC5690, (5) HFD with MTCC5689, (6) HFD with metformin, and 7) HFD with vildagliptin for a period of 6 months. Biochemical markers, glucose tolerance, insulin resistance, and GLP-1 and LPS levels were assessed by standard protocols. Gut integrity was measured by intestinal permeability test. Transcriptional levels of tight junction proteins (TJPs) were probed in small intestinal tissues while inflammatory signals and other pathway specific genes were profiled in liver, visceral adipose tissue, and skeletal muscle.. Mice fed with HFD became insulin resistant, glucose intolerant, hyperglycemic, and dyslipidemic. Diabetic mice were characterized to exhibit decreased levels of GLP-1, increased gut permeability, increased circulatory levels of LPS, decrease in the gene expression patterns of intestinal tight junction markers (occludin and ZO-1), and increased proinflammatory gene markers (TNFα and IL6) in visceral fat along with decreased mRNA expression of FIAF and adiponectin. Diabetic mice also exhibited increased mRNA expression of ER stress markers in skeletal muscle. In addition, liver from HFD-fed diabetic mice showed increased gene expressions of proinflammation, lipogenesis, and gluconeogenesis. Probiotic interventions (most prominently the MTCC5689) resisted insulin resistance and development of diabetes in mice under HFD feeding and beneficially modulated all the biochemical and molecular alterations in a mechanistic way in several tissues. The metabolic benefits offered by the probiotics were also more or less similar to that of standard drugs such as metformin and vildagliptin.. Native probiotic strains MTCC 5690 and MTCC 5689 appear to have potential against insulin resistance and type 2 diabetes with mechanistic, multiple tissue-specific mode of actions. Topics: Animals; Blood Glucose; Diabetes Mellitus, Experimental; Diabetes Mellitus, Type 2; Diet, High-Fat; Dyslipidemias; Endoplasmic Reticulum Stress; Gastrointestinal Microbiome; Glucagon-Like Peptide 1; Gluconeogenesis; Glucose Intolerance; India; Inflammation; Insulin Resistance; Lactobacillus plantarum; Limosilactobacillus fermentum; Lipids; Lipogenesis; Lipopolysaccharides; Male; Mice; Mice, Inbred C57BL; Probiotics; Transcriptome | 2018 |
Molecular modeling and statistical analysis in the design of derivatives of human dipeptidyl peptidase IV.
Human dipeptidyl peptidase IV (hDDP-IV) has a considerable importance in inactivation of glucagon-like peptide-1, which is related to type 2 diabetes. One approach for the treatment is the development of small hDDP-IV inhibitors. In order to design better inhibitors, we analyzed 5-(aminomethyl)-6-(2,4-dichlrophenyl)-2-(3,5-dimethoxyphenyl)pyrimidin-4-amine and a set of 24 molecules found in the BindingDB web database for model designing. The analysis of their molecular properties allowed the design of a multiple linear regression model for activity prediction. Their docking analysis allowed visualization of the interactions between the pharmacophore regions and hDDP-IV. After both analyses were performed, we proposed a set of nine molecules in order to predict their activity. Four of them displayed promising activity, and thus, had their docking performed, as well as, the pharmacokinetic and toxicological study. Two compounds from the proposed set showed suitable pharmacokinetic and toxicological characteristics, and therefore, they were considered promising for future synthesis and in vitro studies. Topics: Binding Sites; Diabetes Mellitus, Type 2; Dipeptidyl Peptidase 4; Dipeptidyl-Peptidase IV Inhibitors; Glucagon-Like Peptide 1; Humans; Hypoglycemic Agents; Models, Molecular; Molecular Docking Simulation; Structure-Activity Relationship | 2018 |
Differential increments of basal glucagon-like-1 peptide concentration among SLC47A1 rs2289669 genotypes were associated with inter-individual variability in glycaemic response to metformin in Chinese people with newly diagnosed Type 2 diabetes.
To elucidate the effects of rs2289669, an intron variant of the SLC47A1 gene, on glucose response to metformin in Chinese people with newly diagnosed Type 2 diabetes.. Rs2289669 was genotyped, using Sequenom, in 291 participants receiving 48 weeks of metformin monotherapy. The changes in HbA. We found that, compared with participants with a homozygous G allele, those carrying the minor A allele had significantly greater HbA. Our findings suggest that rs2289669 might help predict the glycaemic response to metformin in Chinese people newly diagnosed with Type 2 diabetes, and that differential increases in basal glucagon-like peptide-1 concentration among rs2289669 genotypes might be associated with inter-individual response to metformin. Topics: Adult; China; Cohort Studies; Diabetes Mellitus, Type 2; Drug Resistance; Female; Follow-Up Studies; Genetic Association Studies; Glucagon-Like Peptide 1; Glycated Hemoglobin; Humans; Hyperglycemia; Hypoglycemia; Hypoglycemic Agents; Introns; Linear Models; Male; Metformin; Middle Aged; Organic Cation Transport Proteins; Polymorphism, Single Nucleotide; Prospective Studies | 2017 |
All-cause mortality in patients with diabetes under glucagon-like peptide-1 agonists: A population-based, open cohort study.
The glucagon-like peptide-1 receptor agonist (GLP1a) liraglutide has been described to benefit patients with type 2 diabetes mellitus (T2DM) at high cardiovascular risk. However, there are still uncertainties relating to these cardiovascular benefits: whether they also apply to an unselected diabetic population that includes low-risk patients, represent a class-effect, and could be observed in a real-world setting.. We conducted a population-based, retrospective open cohort study using data derived from The Health Improvement Network database between Jan 2008 to Sept 2015. Patients with T2DM exposed to GLP1a (n=8345) were compared to age, gender, body mass index, duration of T2DM and smoking status-matched patients with T2DM unexposed to GLP1a (n=16,541).. Patients with diabetes receiving GLP1a were significantly less likely to die from any cause compared to matched control patients with diabetes (adjusted incidence rate ratio [aIRR]: 0.64, 95% CI: 0.56-0.74, P-value<0.0001). Similar findings were observed in low-risk patients (aIRR: 0.64, 95% CI: 0.53-0.76, P -value=0.0001). No significant difference in the risk of incident CVD was detected in the low-risk patients (aIRR: 0.93, 95% CI: 0.83-1.12). Subgroup analyses suggested that effect is persistent in the elderly or across glycated haemoglobin categories.. GLP1a treatment in a real-world setting may confer additional mortality benefit in patients with T2DM irrespective of their baseline CVD risk, age or baseline glycated haemoglobin and was sustained over the observation period. Topics: Aged; Cardiovascular Diseases; Diabetes Mellitus, Type 2; Female; Glucagon-Like Peptide 1; Humans; Hypoglycemic Agents; Liraglutide; Male; Middle Aged; Retrospective Studies | 2017 |
Design, synthesis and biological evaluation of PEGylated Xenopus glucagon-like peptide-1 derivatives as long-acting hypoglycemic agents.
Topics: Animals; Blood Glucose; Cysteine; Diabetes Mellitus, Type 2; Drug Design; Glucagon-Like Peptide 1; Half-Life; Humans; Hypoglycemic Agents; Insulin; Mice, Inbred Strains; Mutagenesis, Site-Directed; Mutant Chimeric Proteins; Polyethylene Glycols; Xenopus | 2017 |
Mathematical Modelling of Glucose-Dependent Insulinotropic Polypeptide and Glucagon-like Peptide-1 following Ingestion of Glucose.
The incretin hormones, glucose-dependent insulinotropic polypeptide (GIP) and glucagon-like peptide-1 (GLP-1), play an important role in glucose homeostasis by potentiating glucose-induced insulin secretion. Furthermore, GLP-1 has been reported to play a role in glucose homeostasis by inhibiting glucagon secretion and delaying gastric emptying. As the insulinotropic effect of GLP-1 is preserved in patients with type 2 diabetes (T2D), therapies based on GLP-1 have been developed in recent years, and these have proven to be efficient in the treatment of T2D. The endogenous secretion of both GIP and GLP-1 is stimulated by glucose in the small intestine, and the release is dependent on the amount. In this work, we developed a semimechanistic model describing the release of GIP and GLP-1 after ingestion of various glucose doses in healthy volunteers and patients with T2D. In the model, the release of both hormones is stimulated by glucose in the proximal small intestine, and no differences in the secretion dynamics between healthy individuals and patients with T2D were identified after taking differences in glucose profiles into account. Topics: Adult; Aged; Case-Control Studies; Diabetes Mellitus, Type 2; Female; Gastric Emptying; Gastric Inhibitory Polypeptide; Glucagon-Like Peptide 1; Glucose; Glucose Tolerance Test; Hormone Antagonists; Humans; Intestinal Absorption; Intestine, Small; Kinetics; Male; Middle Aged; Models, Biological; Reproducibility of Results | 2017 |
Glucagon-like peptide 1-related peptides increase nitric oxide effects to reduce platelet activation.
Glucagon-like peptide 1 (GLP-1) is object of intensive investigation for not only its metabolic effects but also the protective vascular actions. Since platelets exert a primary role in the pathogenesis of atherosclerosis, inflammation and vascular complications, we investigated whether GLP-1 directly influences platelet reactivity. For this purpose, in platelets from 72 healthy volunteers we evaluated GLP-1 receptor (GLP-1R) expression and the effects of a 15-minute incubation with the native form GLP-1(7-36), the N-terminally truncated form GLP-1(9-36) and the GLP-1 analogue Liraglutide (100 nmol/l) on: i) aggregation induced by collagen or arachidonic acid (AA); ii) platelet function under shear stress; iii) cGMP and cAMP synthesis and cGMP-dependent protein kinase (PKG)-induced Vasodilator-Stimulated-Phosphoprotein (VASP) phosphorylation; iv) activation of the signalling molecules Phosphatidylinositol 3-Kinase (PI3-K)/Akt and Mitogen Activated Protein Kinase (MAPK)/ERK-1/2; and v) oxidative stress. Experiments were repeated in the presence of the nitric oxide donor Na-nitroprusside. We found that platelets constitutively express GLP-1R and that, independently of GLP-1R, GLP-1(7-36), GLP-1(9-36) and Liraglutide exert platelet inhibitory effects as shown by: a) increased NO-antiaggregating effects, b) increased the activation of the cGMP/PKG/VASP pathway, c) reduced the activation of PI3-K/Akt and MAPK/ERK-2 pathways, d) reduced the AA-induced oxidative stress. When the experiments were repeated in the presence of the antagonist of GLP-1R Exendin(9-39), the platelet inhibitory effects were maintained, thus indicating a mechanism independent of GLP-1R. In conclusion, GLP-1(7-36), its degradation product GLP-1(9-36) and Liraglutide exert similar inhibitory effects on platelet activation, suggesting a potential protective effect on the cardiovascular system. Topics: Adult; Blood Platelets; Cell Adhesion Molecules; Cells, Cultured; Cyclic GMP; Diabetes Mellitus, Type 2; Female; Glucagon-Like Peptide 1; Glucagon-Like Peptide-1 Receptor; Humans; Liraglutide; Male; Microfilament Proteins; Nitric Oxide; Nitroprusside; Peptide Fragments; Phosphatidylinositol 3-Kinases; Phosphoproteins; Phosphorylation; Platelet Activation; Signal Transduction | 2017 |
Favorable Effect on Blood Volume Control in Hemodialysis Patients with Type 2 Diabetes after Switching from Insulin Therapy to Liraglutide, a Human Glucagon-like Peptide-1 Analog--Results from a Pilot Study in Japan-.
Hemodialysis patients are advised to limit the intake of foods in order to control volume status and body weight (BW). We report the clinical course of five Japanese hemodialysis patients with type 2 diabetes mellitus (T2DM) who were switched from insulin to liraglutide, and the efficacy of the treatment, especially in terms of changes in interdialysis weight gain (IDWG).. This retrospective pilot study included 5 Japanese hemodialysis patients with T2DM. Insulin and other oral hypoglycemic agents, if any, were discontinued before switching to liraglutide. The initial dose of liraglutide was set at 0.3 mg/day for more than 1 week, increased to 0.6 mg/day for more than 1 week and then, to 0.9 mg/day if needed.. Switching from insulin to liraglutide seems effective in hemodialysis patients with T2DM, especially in those with difficult blood fluid volume control associated with failure of dietary restriction. Topics: Aged; Blood Volume; Body Mass Index; Diabetes Mellitus, Type 2; Diet; Drug Substitution; Female; Glucagon-Like Peptide 1; Glycated Hemoglobin; Humans; Insulin; Japan; Liraglutide; Male; Middle Aged; Pilot Projects; Renal Dialysis; Retrospective Studies; Treatment Outcome; Weight Gain | 2017 |
Topical Intestinal Aminoimidazole Agonists of G-Protein-Coupled Bile Acid Receptor 1 Promote Glucagon Like Peptide-1 Secretion and Improve Glucose Tolerance.
The role of the G-protein-coupled bile acid receptor TGR5 in various organs, tissues, and cell types, specifically in intestinal endocrine L-cells and brown adipose tissue, has made it a promising therapeutical target in several diseases, especially type-2 diabetes and metabolic syndrome. However, recent studies have shown deleterious on-target effects of systemic TGR5 agonists. To avoid these systemic effects while stimulating glucagon-like peptide-1 (GLP-1) secreting enteroendocrine L-cells, we have designed TGR5 agonists with low intestinal permeability. In this article, we describe their synthesis, characterization, and biological evaluation. Among them, compound 24 is a potent GLP-1 secretagogue, has low effect on gallbladder volume, and improves glucose homeostasis in a preclinical murine model of diet-induced obesity and insulin resistance, making the proof of concept of the potential of topical intestinal TGR5 agonists as therapeutic agents in type-2 diabetes. Topics: Amination; Animals; Caco-2 Cells; Diabetes Mellitus, Type 2; Glucagon-Like Peptide 1; Glucose; Glucose Tolerance Test; Humans; Hypoglycemic Agents; Imidazoles; Intestinal Absorption; Intestinal Mucosa; Mice, Inbred C57BL; Receptors, G-Protein-Coupled | 2017 |
Adherence and persistence in patients with type 2 diabetes mellitus newly initiating canagliflozin, dapagliflozin, dpp-4s, or glp-1s in the United States.
Sodium-glucose co-transporter 2 inhibitors were first approved in the US in 2013; therefore, real-world (RW) studies describing outcomes are limited. This retrospective study evaluated adherence and persistence among patients initiating canagliflozin (CANA), dapagliflozin (DAPA), GLP-1 agonists (GLP-1s), and DPP-4 inhibitors (DPP-4s) over a 12-month follow-up from a US managed care perspective.. Patients newly initiating CANA, DAPA, GLP-1s, or DPP-4s from February 1, 2014-June 30, 2014 were identified from the QuintilesIMS PharMetrics Plus Database. The first fill defined the index date/drug. Patients were required to have a T2DM diagnosis (ICD-9-CM 250.x[0,2]) and ≥12 months of continuous enrollment pre- and post-index (follow-up). Main outcome measures were adherence (proportion of days covered, PDC; medication possession ratio, MPR) and persistence on index therapy. PDC or MPR ≥0.80 was considered adherent. Patients were considered persistent until evidence of discontinuation (gap ≥90 days between two subsequent index therapy prescriptions). Kaplan-Meier (KM) analysis assessed time to discontinuation, while a Cox proportional hazards model (PHM) evaluated risk of discontinuation. Logistic regression models evaluated the likelihood of non-adherence.. The final sample consisted of 23,702 patients (6,546 CANA, 3,087 DAPA, 6,273 GLP-1s, and 7,796 DPP-4s; 56% male, and mean [SD] age = 55 [9.1] years). Mean PDC ranged from 0.56 (GLP-1), to 0.71 (CANA), with 33-56% adherent, respectively; MPR results were similar. Fifty-two per cent (GLP-1) to 68% (CANA) were persistent over the follow-up. CANA patients had the longest time to discontinuation. In regression analyses, compared to CANA 100 mg, DAPA, DPP-4, and GLP-1 patients had a significantly higher likelihood of non-adherence and a significantly higher risk of discontinuation. CANA 300 mg patients had a significantly lower likelihood of non-adherence and a significantly lower risk of discontinuation compared to CANA 100 mg.. Adherence and persistence were significantly better with CANA (100 mg and 300 mg) compared to DAPA, GLP-1s, and DPP-4s in the RW setting. Topics: Adolescent; Adult; Aged; Benzhydryl Compounds; Canagliflozin; Databases, Factual; Diabetes Mellitus, Type 2; Dipeptidyl-Peptidase IV Inhibitors; Female; Glucagon-Like Peptide 1; Glucosides; Humans; Hypoglycemic Agents; Logistic Models; Male; Medication Adherence; Middle Aged; Proportional Hazards Models; Retrospective Studies; United States; Young Adult | 2017 |
A sandwich ELISA for measurement of the primary glucagon-like peptide-1 metabolite.
Glucagon-like peptide-1 (GLP-1) is an incretin hormone secreted from the gastrointestinal tract. It is best known for its glucose-dependent insulinotropic effects. GLP-1 is secreted in its intact (active) form (7-36NH Topics: Area Under Curve; Diabetes Mellitus, Type 2; Dipeptidyl-Peptidase IV Inhibitors; Enzyme-Linked Immunosorbent Assay; Glucagon-Like Peptide 1; Glucose Tolerance Test; Healthy Volunteers; Humans; Infusions, Intravenous; Peptide Fragments; Peptides; Reproducibility of Results | 2017 |
Effects of GW002, a novel recombinant human glucagon-like peptide-1 (GLP-1) analog fusion protein, on CHO recombinant cells and BKS-db mice.
GLP-1-based strategies have many advantages in treatment of type 2 diabetes mellitus (T2DM), but native GLP-1 has a short half-life in the circulation, which limits its clinical application. The purpose of this study was to evaluate the effects of GW002, a novel recombinant GLP-1 analog fusion protein produced by linking the human GLP-1 analog C-terminus to the N-terminus of human serum albumin via a linker, in vitro and in BKS-db mice.. To determine whether GW002 can activate the GLP-1 receptor in cells, the level of luciferase expression was evaluated in vitro. In vivo, body weight, food intake, non-fasting and fasting blood glucose, oral glucose tolerance test, blood glucose and insulin levels, liver histology, liver function parameters and antibody levels in BKS-db mice were investigated to evaluate the effects of GW002. Albiglutide was chosen as a positive comparator.. Cyclic adenosine monophosphate levels were increased in a dose-dependent manner in cells. In vivo studies demonstrated that GW002 lowers non-fasting and fasting blood glucose levels and improves glucose tolerance and insulin secretion in BKS-db mice. The degree of hepatic steatosis and hepatic biochemical indexes was also decreased. In this study, the mice body weight was not reduced significantly.. The above results showed that the efficacy of GW002 in BKS-db mice displayed a significant hypoglycemic effect, which indicated that GW002 might be a potential candidate for the treatment of T2DM. Topics: Animals; Blood Glucose; Body Weight; CHO Cells; Cricetinae; Cricetulus; Diabetes Mellitus, Experimental; Diabetes Mellitus, Type 2; Glucagon-Like Peptide 1; Glucagon-Like Peptide-1 Receptor; Glucose Tolerance Test; Humans; Hypoglycemic Agents; Insulin; Male; Mice; Mice, Inbred C57BL; Mice, Transgenic | 2017 |
Recommendations on the effect of antidiabetic drugs in bone.
To provide recommendations on the effect of antidiabetic drugs on bone fragility to help select the most adequate antidiabetic treatment, especially in diabetic patients with high risk of fracture.. Members of the Bone Metabolism Working Group of the Spanish Society of Endocrinology.. The GRADE system (Grading of Recommendations, Assessment, Development, and Evaluation) was used to establish both the strength of recommendations and the quality of evidence. A systematic search was made in MEDLINE (Pubmed) using the following terms associated to the name of each antidiabetic drug: AND "osteoporosis", "fractures", "bone mineral density", "bone markers", "calciotropic hormones". Papers in English with publication date before 30 April 2016 were reviewed. Recommendations were jointly discussed by the Working Group.. The document summaries the data on the potential effects of antidiabetic drugs on bone metabolism and fracture risk. Topics: Aged; Bone Remodeling; Bone Resorption; Contraindications, Drug; Diabetes Mellitus, Type 2; Dipeptidyl-Peptidase IV Inhibitors; Female; Fractures, Spontaneous; Glucagon-Like Peptide 1; Humans; Hypoglycemic Agents; Insulin; Male; Metformin; Middle Aged; Osteoporosis; Randomized Controlled Trials as Topic; Sodium-Glucose Transporter 2 Inhibitors; Sulfonylurea Compounds; Thiazolidinediones | 2017 |
A Specific Gut Microbiota Dysbiosis of Type 2 Diabetic Mice Induces GLP-1 Resistance through an Enteric NO-Dependent and Gut-Brain Axis Mechanism.
Glucagon-like peptide-1 (GLP-1)-based therapies control glycemia in type 2 diabetic (T2D) patients. However, in some patients the treatment must be discontinued, defining a state of GLP-1 resistance. In animal models we identified a specific set of ileum bacteria impairing the GLP-1-activated gut-brain axis for the control of insulin secretion and gastric emptying. Using prediction algorithms, we identified bacterial pathways related to amino acid metabolism and transport system modules associated to GLP-1 resistance. The conventionalization of germ-free mice demonstrated their role in enteric neuron biology and the gut-brain-periphery axis. Altogether, insulin secretion and gastric emptying require functional GLP-1 receptor and neuronal nitric oxide synthase in the enteric nervous system within a eubiotic gut microbiota environment. Our data open a novel route to improve GLP-1-based therapies. Topics: Animals; Brain; Diabetes Mellitus, Type 2; Dysbiosis; Enteric Nervous System; Gastrointestinal Microbiome; Gastrointestinal Tract; Glucagon-Like Peptide 1; Glucagon-Like Peptide-1 Receptor; Male; Mice; Mice, Inbred C57BL; Nitric Oxide | 2017 |
Therapy: Liraglutide - preventing or postponing T2DM diagnosis?
Topics: Blood Glucose; Diabetes Mellitus, Type 2; Glucagon-Like Peptide 1; Glycated Hemoglobin; Humans; Hypoglycemic Agents; Liraglutide | 2017 |
Increased β-Cell Mass in Obese Rats after Gastric Bypass: A Potential Mechanism for Improving Glycemic Control.
BACKGROUND Over the past few decades, bariatric surgery, especially Roux-en-Y gastric bypass (RYGB), has become widely considered the most effective treatment for morbid obesity. In most cases, it results in enhanced glucose management in patients with obesity and type 2 diabetes (T2D), which is observed before significant weight loss. However, what accounts for this effect remains controversial. To gain insight into the benefits of RYGB in T2D, we investigated changes in the β-cell mass of obese rats following RYGB. MATERIAL AND METHODS RYGB or a sham operation was performed on obese rats that had been fed a high-fat diet (HFD) for 16 weeks. Then, the HFD was continued for 8 weeks in both groups. Additional normal chow diet (NCD) and obese groups were used as controls. RESULTS In the present study, RYGB induced improved glycemic control and enhanced β-cell function, which was reflected in a better glucose tolerance and a rapidly increased secretion of insulin and C-peptide after glucose administration. Consistently, rats in the RYGB group displayed increased β-cell mass and islet numbers, which were attributed in part to increased glucagon-like peptide 1 levels following RYGB. CONCLUSIONS Our data indicate that RYGB can improve b-cell function via increasing β-cell mass, which plays a key role in improved glycemic control after RYGB. Topics: Animals; Bariatric Surgery; Blood Glucose; Body Mass Index; Diabetes Mellitus, Type 2; Diet, High-Fat; Disease Models, Animal; Gastric Bypass; Glucagon-Like Peptide 1; Glucose; Glucose Tolerance Test; Insulin; Insulin Resistance; Insulin-Secreting Cells; Islets of Langerhans; Male; Obesity; Obesity, Morbid; Rats; Rats, Sprague-Dawley; Weight Loss | 2017 |
HNF1α defect influences post-prandial lipid regulation.
Hepatocyte nuclear factor 1 alpha (HNF1α) defects cause Mature Onset Diabetes of the Young type 3 (MODY3), characterized by defects in beta-cell insulin secretion. However, HNF1α is involved in many other metabolic pathways with relevance for monogenic or polygenic type 2 diabetes. We aimed to investigate gut hormones, lipids, and insulin regulation in response to a meal test in HNF1α defect carriers (MODY3) compared to non-diabetic subjects (controls) and type 2 diabetes (T2D).. We administered a standardized liquid meal to each participant. Over 6 hours, we measured post-meal responses of insulin regulation (blood glucose, c-peptide, insulin), gut hormones (ghrelin, glucose-dependent insulinotropic polypeptide, glucagon-like peptide-1) and lipids (non-esterified fatty acids [NEFA] and triglycerides).. We found that MODY3 participants had lower insulin secretion indices than controls and T2D participants, showing the expected β-cell defect. MODY3 had similar glycated hemoglobin levels (HbA1c median [IQR]: 6.5 [5.6-7.6]%) compared to T2D (median: 6.6 [6.2-6.9]%; P<0.05). MODY3 had greater insulin sensitivity (Matsuda index: 71.9 [29.6; 125.5]) than T2D (3.2 [4.0; 6.0]; P<0.05). MODY3 experienced a larger decrease in the ratio of NEFA to insulin (NEFA 30-0 / insulin 30-0: -39 [-78; -30] x104) in the early post-prandial period (0-30 minutes) compared to controls and to T2D (-2.0 [-0.6; -6.4] x104; P<0.05). MODY3 had lower fasting (0.66 [0.46; 1.2] mM) and post-meal triglycerides levels compared to T2D (fasting: 2.3 [1.7; 2.7] mM; P<0.05). We did not detect significant post-meal differences in ghrelin and incretins between MODY3 and other groups.. In response to a standard meal test, MODY3 showed greater early post-prandial NEFA diminution in response to relatively low early insulin secretion, and they maintained very low post-prandial triglycerides levels. Topics: Adolescent; Adult; Aged; Blood Glucose; C-Peptide; Child; Diabetes Mellitus, Type 2; Fatty Acids, Nonesterified; Female; Gastric Inhibitory Polypeptide; Ghrelin; Glucagon-Like Peptide 1; Hepatocyte Nuclear Factor 1-alpha; Humans; Insulin; Male; Middle Aged; Postprandial Period; Triglycerides; Young Adult | 2017 |
Glucagonlike peptide 1 analogs in diabetes care.
Topics: Cardiovascular Diseases; Diabetes Mellitus, Type 2; Glucagon-Like Peptide 1; Glucagon-Like Peptides; Glycated Hemoglobin; Humans; Liraglutide; Neoplasms; Randomized Controlled Trials as Topic | 2017 |
The Molecular Mechanism of Glucagon-Like Peptide-1 Therapy in Alzheimer's Disease, Based on a Mechanistic Target of Rapamycin Pathway.
The mechanistic target of rapamycin (mTOR) is an important molecule that connects aging, lifespan, energy balance, glucose and lipid metabolism, and neurodegeneration. Rapamycin exerts effects in numerous biological activities via its target protein, playing a key role in energy balance, regulation of autophagy, extension of lifespan, immunosuppression, and protection against neurodegeneration. There are many similar pathophysiological processes and molecular pathways between Alzheimer's disease (AD) and type 2 diabetes mellitus (T2DM), and pharmacologic agents used to treat T2DM, including glucagon-like peptide-1 (GLP-1) analogs, seem to be beneficial for AD. mTOR mediates the effects of GLP-1 analogs in the treatment of T2DM; hence, I hypothesize that mTOR is a key molecule for mediating the protective effects of GLP-1 for AD. Topics: Alzheimer Disease; Animals; Diabetes Mellitus, Type 2; Glucagon-Like Peptide 1; Humans; Neuroprotective Agents; Signal Transduction; TOR Serine-Threonine Kinases | 2017 |
Mechanistic insights into the effects of quercetin and/or GLP-1 analogue liraglutide on high-fat diet/streptozotocin-induced type 2 diabetes in rats.
The development of complementary treatment strategies that focuses on achieving a balance between adaptive and apoptotic unfolded protein response (UPR), enhancing endoplasmic reticulum (ER) homeostasis, and thus preserving β cell mass and function is particularly warranted.. This study was designed to investigate the effectiveness of the combined treatment by Quercetin (QUE) and Liraglutide (LIRA) in modulating hyperglycemia, insulin-insensitivity, UPR/ER stress markers, apoptosis, oxidative stress and inflammation using a high-fat diet/streptozotocin -induced type 2 diabetic rat model.. Sixty male albino rats were allocated into five equal groups: normal control, diabetic control, LIRA treated diabetic; QUE treated diabetic and combined treatment diabetic groups. Fasting glucose, insulin, CHOP, macrophage inflammatory protein -1 α (MIP-1α) and Bax, Bcl. The combined treatment with both LIRA and QUE causes significant improvements in all the studied parameters; including XBP1 splicing, CHOP, MIP-1α, Bax/Bcl. Our study nominates this combination to be used in T2DM to achieve adequate glycaemic control and to preserve optimal β cell function. Topics: Animals; Diabetes Mellitus, Type 2; Diet, High-Fat; Drug Therapy, Combination; Glucagon-Like Peptide 1; Hypoglycemic Agents; Liraglutide; Male; Quercetin; Rats; Streptozocin; Treatment Outcome | 2017 |
Incretin-based therapy for type 2 diabetes: What have we learned from the meta-analyses?
Topics: Diabetes Mellitus, Type 2; Glucagon-Like Peptide 1; Humans; Hypoglycemic Agents; Incretins | 2017 |
Incretin-Based Therapies: Revisiting Their Mode of Action.
Topics: Diabetes Mellitus, Type 2; Dipeptidyl-Peptidase IV Inhibitors; Glucagon-Like Peptide 1; Glucagon-Like Peptide-1 Receptor; Humans; Hypoglycemic Agents; Incretins | 2017 |
Interleukin 6 protects pancreatic β cells from apoptosis by stimulation of autophagy.
IL-6 is a pleiotropic cytokine with complex roles in inflammation and metabolic disease. The role of IL-6 as a pro- or anti-inflammatory cytokine is still unclear. Within the pancreatic islet, IL-6 stimulates secretion of the prosurvival incretin hormone glucagon-like peptide 1 (GLP-1) by α cells and acts directly on β cells to stimulate insulin secretion Topics: Adaptor Proteins, Signal Transducing; Animals; Apoptosis; Autophagy; Cell Line; Diabetes Mellitus, Type 2; Gene Expression Regulation; Glucagon-Like Peptide 1; Humans; Infusion Pumps, Implantable; Insulin-Secreting Cells; Interleukin-6; Islets of Langerhans; Male; Mice; Microtubule-Associated Proteins; Rats; Recombinant Proteins; Signal Transduction | 2017 |
The SNARE Protein Syntaxin-1a Plays an Essential Role in Biphasic Exocytosis of the Incretin Hormone Glucagon-Like Peptide 1.
Exocytosis of the hormone glucagon-like peptide 1 (GLP-1) by the intestinal L cell is essential for the incretin effect after nutrient ingestion and is critical for the actions of dipeptidyl peptidase 4 inhibitors that enhance GLP-1 levels in patients with type 2 diabetes. Two-photon microscopy revealed that exocytosis of GLP-1 is biphasic, with a first peak at 1-6 min and a second peak at 7-12 min after stimulation with forskolin. Approximately 75% of the exocytotic events were represented by compound granule fusion, and the remainder were accounted for by full fusion of single granules under basal and stimulated conditions. The core SNARE protein syntaxin-1a (syn1a) was expressed by murine ileal L cells. At the single L-cell level, first-phase forskolin-induced exocytosis was reduced to basal ( Topics: Animals; Cells, Cultured; Diabetes Mellitus, Type 2; Enteroendocrine Cells; Exocytosis; Female; Gene Expression Regulation; Glucagon-Like Peptide 1; Glucose; Ileum; Male; Mice; Mice, Inbred C57BL; Mice, Knockout; Obesity; Syntaxin 1 | 2017 |
Single-Molecule Combinatorial Therapeutics for Treating Obesity and Diabetes.
Topics: Brain; Diabetes Mellitus; Diabetes Mellitus, Type 2; Gastric Inhibitory Polypeptide; Glucagon; Glucagon-Like Peptide 1; Humans; Obesity; Precision Medicine | 2017 |
The GLP-1 analogue lixisenatide decreases atherosclerosis in insulin-resistant mice by modulating macrophage phenotype.
Recent clinical studies indicate that glucagon-like peptide-1 (GLP-1) analogues prevent acute cardiovascular events in type 2 diabetes mellitus but their mechanisms remain unknown. In the present study, the impact of GLP-1 analogues and their potential underlying molecular mechanisms in insulin resistance and atherosclerosis are investigated.. Atherosclerosis development was evaluated in Apoe. Treatment of Apoe. Lixisenatide decreases atheroma plaque size and instability in Apoe Topics: Animals; Atherosclerosis; Diabetes Mellitus, Type 2; Glucagon-Like Peptide 1; Inflammation; Insulin Resistance; Macrophages; Mice; Peptides; STAT3 Transcription Factor | 2017 |
Purification of family B G protein-coupled receptors using nanodiscs: Application to human glucagon-like peptide-1 receptor.
Family B G protein-coupled receptors (GPCRs) play vital roles in hormone-regulated homeostasis. They are drug targets for metabolic diseases, including type 2 diabetes and osteoporosis. Despite their importance, the signaling mechanisms for family B GPCRs at the molecular level remain largely unexplored due to the challenges in purification of functional receptors in sufficient amount for biophysical characterization. Here, we purified the family B GPCR human glucagon-like peptide-1 (GLP-1) receptor (GLP1R), whose agonists, e.g. exendin-4, are used for the treatment of type 2 diabetes mellitus. The receptor was expressed in HEK293S GnTl- cells using our recently developed protocol. The protocol incorporates the receptor into the native-like lipid environment of reconstituted high density lipoprotein (rHDL) particles, also known as nanodiscs, immediately after the membrane solubilization step followed by chromatographic purification, minimizing detergent contact with the target receptor to reduce denaturation and prolonging stabilization of receptor in lipid bilayers without extra steps of reconstitution. This method yielded purified GLP1R in nanodiscs that could bind to GLP-1 and exendin-4 and activate Gs protein. This nanodisc purification method can potentially be a general strategy to routinely obtain purified family B GPCRs in the 10s of microgram amounts useful for spectroscopic analysis of receptor functions and activation mechanisms. Topics: Diabetes Mellitus, Type 2; Exenatide; Glucagon-Like Peptide 1; Glucagon-Like Peptide-1 Receptor; HEK293 Cells; Humans; Hypoglycemic Agents; Lipid Bilayers; Lipoproteins, HDL; Microscopy, Electron, Transmission; Nanostructures; Nanotechnology; Peptides; Protein Binding; Receptors, G-Protein-Coupled; Reproducibility of Results; Venoms | 2017 |
BPI-3016, a novel long-acting hGLP-1 analogue for the treatment of Type 2 diabetes mellitus.
Glucagon-like peptide-1 (GLP-1) analogues have been commonly used as add-on medications for patients with Type 2 diabetes mellitus (T2DM). Currently, the development of long-acting GLP-1 analogues which allow the freedom and flexibility of once-weekly injections while maintaining their potency for a relatively long period has become the mainstream. Here, we successfully developed a long-acting human GLP-1(7-37) analogue (BPI-3016) with significantly extended half-life and increased resistance to dipeptidyl peptidase IV (DPP-IV) cleavage by structural modifications of human GLP-1. In vitro activity of BPI-3016 including GLP-1 receptor affinity and stimulation of cyclic adenosine monophosphate (cAMP) production was measured. In vivo activity of BPI-3016 such as its effects on glycemic control, β-cell mass and body weight was evaluated in ob/ob mice, db/db mice, and spontaneous diabetic cynomolgus monkeys. The results indicated that BPI-3016 preserved receptor affinity to GLP receptors, and was capable of stimulating cAMP production. In in vivo pharmacokinetic study, the half-life of BPI-3016 was more than 95h after single dosing in diabetic cynomolgus monkeys. Also, BPI-3016 reduced fasting and post-prandial plasma glucose levels for up to a week after a single dose; It reduced body mass index (BMI), body fat, improved glucose tolerance and showed insulinotropic effects after once-weekly injection for 7 weeks. In conclusion, BPI-3016 retains the effects of GLP-1 with significantly prolonged half-life, making it a promising therapy for type 2 diabetes with once-weekly treatment in the clinic. Topics: Animals; Blood Glucose; Diabetes Mellitus, Type 2; Female; Glucagon-Like Peptide 1; Glucagon-Like Peptide-1 Receptor; HEK293 Cells; Humans; Hypoglycemic Agents; Insulin-Secreting Cells; Macaca fascicularis; Male; Mice; Peptide Fragments | 2017 |
Bariatric surgery may reduce the risk of Alzheimer's diseases through GLP-1 mediated neuroprotective effects.
Obesity and diabetes are associated with deficits in multiple neurocognitive domains and increased risk for dementia. Over the last two decades, there has been a significant increase in bariatric and metabolic surgery worldwide, driven by rising intertwined pandemics of obesity and diabetes, along with improvement in surgical techniques. Patients undergoing bariatric surgery achieve a significant decrease in their excess weight and a multitude of sequela associated with obesity, diabetes, and metabolic syndrome. Glucagon-like peptide 1 (GLP-1) is an intestinal peptide that has been implicated as one of the weight loss-independent mechanisms in how bariatric surgery affects type 2 diabetes. GLP-1 improves insulin secretion, inhibits apoptosis and induce pancreatic islet neogenesis, promotes satiety, and can regulate heart rate and blood pressure. Moreover, numerous studies have demonstrated potential neuroprotective and neurotrophic effects of GLP-1. Increased GLP-1 activity has been shown to increase cortical activity, promote neuronal growth, and inhibit neuronal degeneration. Specifically, in experimental studies on Alzheimer's disease, GLP-1 decreases amyloid deposition and neurofibrillary tangles. Furthermore, recent studies have also suggested that GLP-1 based therapies, new class of antidiabetic drugs, have favorable effects on neurodegenerative disorders such as Alzheimer's disease. We present a hypothesis that bariatric surgery can help delay or even prevent the onset of Alzheimer's disease in long-term by increasing the levels of GLP-1. This hypothesis has a potential for many studies from basic science projects to large population studies to fully understand the neurological and cognitive consequences of bariatric surgery and associated rise in GLP-1. Topics: Aged; Aged, 80 and over; Alzheimer Disease; Apoptosis; Bariatric Surgery; Diabetes Mellitus, Type 2; Glucagon-Like Peptide 1; Humans; Hypoglycemic Agents; Insulin; Insulin Secretion; Models, Theoretical; Neurons; Neuroprotective Agents; Obesity; Risk; Weight Loss | 2017 |
Will Gut Microbiota Help Design the Next Generation of GLP-1-Based Therapies for Type 2 Diabetes?
Glucagon-like peptide one (GLP-1)-based therapies for reducing hyperglycemia in type 2 diabetic patients are efficient, though some individuals develop GLP-1 resistance. In a recent issue of Cell Metabolism, Grasset et al. (2017) demonstrated that GLP-1 sensitivity is modulated by gut bacteria through NO signaling in the enteric nervous system. Topics: Animals; Diabetes Mellitus, Type 2; Gastrointestinal Microbiome; Glucagon-Like Peptide 1; Humans; Hypoglycemic Agents; Incretins; Nitric Oxide; Receptors, Glucagon; Signal Transduction | 2017 |
Modified human glucagon-like peptide-1 (GLP-1) produced in E. coli has a long-acting therapeutic effect in type 2 diabetic mice.
Glucagon-like peptide 1 (GLP-1) is a very potent insulinotropic hormone secreted into the blood stream after eating. Thus, it has potential to be used in therapeutic treatment of diabetes. The half-life of GLP-1, however, is very short due to its rapid cleavage by dipeptidyl peptidase IV (DPP-IV). This presents a great challenge if it is to be used as a therapeutic drug. GLP-1, like many other small peptides, is commonly produced through chemical synthesis, but is limited by cost and product quantity. In order to overcome these problems, a sequence encoding a six codon-optimized tandem repeats of modified GLP-1 was constructed and expressed in the E. coli to produce a protease-resistant protein, 6×mGLP-1. The purified recombinant 6×mGLP-1, with a yield of approximately 20 mg/L, could be digested with trypsin to obtain single peptides. The single mGLP-1 peptides significantly stimulated the proliferation of a mouse pancreatic β cell line, MIN6. The recombinant peptide also greatly improved the oral glucose tolerance test of mice, exerted a positive glucoregulatory effect, and most notably had a glucose lowering effect for as long as 16.7 hours in mice altered to create a type 2 diabetic condition and exerted a positive glucoregulatory effect in db/db mice. These results indicate that recombinant 6×mGLP-1 has great potential to be used as an effective and cost-efficient drug for the treatment of type 2 diabetes. Topics: Animals; Blood Glucose; Cell Proliferation; Diabetes Mellitus, Experimental; Diabetes Mellitus, Type 2; Disease Models, Animal; Escherichia coli; Glucagon-Like Peptide 1; Glucose Tolerance Test; Humans; Insulin-Secreting Cells; Mice; Peptide Hydrolases; Recombinant Proteins | 2017 |
Once Blind, Now We See GLP-1 Molecular Action.
The macromolecular mechanics of GLP-1 with its cell surface receptor came into focus as two landmark publications recently published in Nature collectively herald advancement in structure-based design for a receptor class of great therapeutic importance (Jazayeri et al., 2017; Zhang et al., 2017). Topics: Diabetes Mellitus, Type 2; Glucagon-Like Peptide 1; Glucagon-Like Peptide-1 Receptor; Humans; Peptides | 2017 |
Engineered Epidermal Progenitor Cells Can Correct Diet-Induced Obesity and Diabetes.
Somatic gene therapy is a promising approach for treating otherwise terminal or debilitating diseases. The human skin is a promising conduit for genetic engineering, as it is the largest and most accessible organ, epidermal autografts and tissue-engineered skin equivalents have been successfully deployed in clinical applications, and skin epidermal stem/progenitor cells for generating such grafts are easy to obtain and expand in vitro. Here, we develop skin grafts from mouse and human epidermal progenitors that were engineered by CRISPR-mediated genome editing to controllably release GLP-1 (glucagon-like peptide 1), a critical incretin that regulates blood glucose homeostasis. GLP-1 induction from engineered mouse cells grafted onto immunocompetent hosts increased insulin secretion and reversed high-fat-diet-induced weight gain and insulin resistance. Taken together, these results highlight the clinical potential of developing long-lasting, safe, and versatile gene therapy approaches based on engineering epidermal progenitor cells. Topics: Animals; Blood Glucose; Body Weight; CRISPR-Cas Systems; Diabetes Mellitus, Type 2; Diet, High-Fat; Epidermis; Gene Editing; Gene Transfer Techniques; Genetic Engineering; Glucagon-Like Peptide 1; Homeostasis; Humans; Mice; Obesity; Skin Transplantation; Stem Cells | 2017 |
Expression of sweet taste receptor and gut hormone secretion in modelled type 2 diabetes.
Sweet taste receptors (STRs) are expressed in L cells which secret glucagon-like peptide-1 (GLP-1) in the gut. The STR blocker lactisole reduces GLP-1 secretion and increases blood glucose levels. Therefore, we investigated the expression of sweet taste molecules in the proximal and distal small intestine, and gut hormone secretion, in healthy control and type 2 diabetic rats. Two groups of rats (Sprague Dawley (SD), and Zucker diabetic fatty (ZDF)) were involved in the study. Each group (n=10) received an intragastric glucose infusion (50% glucose solution, 2g/kg body weight). Blood samples were taken for measurement of blood glucose, plasma insulin, and GLP-1 concentrations. One week later, we obtained small intestinal tissue and detected the expression of STRs and glucose transporters (GTs) by real time polymerase chain reaction (Real Time-PCR). Sweet taste molecules of T1R2, T1R3, α-gustducin and TRPM5 in ileum were dramatically higher than those in duodenum (P<0.01 for each). T1R3, α-gustducin and TRPM5 expression were less in the ileum of ZDF than those in SD (P<0.05 for each), while expression of glucose transporter 2 (GLUT-2) in ileum was significantly higher in ZDF rats. Plasma GLP-1 levels were higher in ZDF rats than SD rats at t=0, 15, 30, 60 and 120min (P<0.01). In conclusion, transcript levels of ileal T1R3 and GLUT-2 are disordered in ZDF rats suggesting that intestinal sweet taste receptor expression is associated with altered glucose metabolism. The mechanism needs further investigation, but might provide a potential therapy in the treatment of type 2 diabetes. Topics: Animals; Blood Glucose; Diabetes Mellitus, Experimental; Diabetes Mellitus, Type 2; Disease Models, Animal; Duodenum; Glucagon-Like Peptide 1; Glucose Transporter Type 2; Ileum; Insulin; Intestinal Mucosa; Male; Rats, Sprague-Dawley; Rats, Zucker; Receptors, G-Protein-Coupled; RNA, Messenger; Taste; Transducin | 2017 |
Lactobacillus casei CCFM419 attenuates type 2 diabetes via a gut microbiota dependent mechanism.
Topics: Animals; Bacteria; Blood Glucose; Diabetes Mellitus, Type 2; Gastrointestinal Microbiome; Glucagon-Like Peptide 1; Humans; Interleukin-6; Intestinal Mucosa; Intestines; Lacticaseibacillus casei; Male; Mice; Mice, Inbred C57BL; Probiotics; Tumor Necrosis Factor-alpha | 2017 |
[6]-Gingerol, from Zingiber officinale, potentiates GLP-1 mediated glucose-stimulated insulin secretion pathway in pancreatic β-cells and increases RAB8/RAB10-regulated membrane presentation of GLUT4 transporters in skeletal muscle to improve hyperglycemi
[6]-Gingerol, a major component of Zingiber officinale, was previously reported to ameliorate hyperglycemia in type 2 diabetic mice. Endocrine signaling is involved in insulin secretion and is perturbed in db/db Type-2 diabetic mice. [6]-Gingerol was reported to restore the disrupted endocrine signaling in rodents. In this current study on Lepr. 4-weeks treatment of [6]-Gingerol dramatically increased glucose-stimulated insulin secretion and improved glucose tolerance. Plasma GLP-1 was found to be significantly elevated in the treated mice. Pharmacological intervention of GLP-1 levels regulated the effect of [6]-Gingerol on insulin secretion. Mechanistically, [6]-Gingerol treatment upregulated and activated cAMP, PKA, and CREB in the pancreatic islets, which are critical components of GLP-1-mediated insulin secretion pathway. [6]-Gingerol upregulated both Rab27a GTPase and its effector protein Slp4-a expression in isolated islets, which regulates the exocytosis of insulin-containing dense-core granules. [6]-Gingerol treatment improved skeletal glycogen storage by increased glycogen synthase 1 activity. Additionally, GLUT4 transporters were highly abundant in the membrane of the skeletal myocytes, which could be explained by the increased expression of Rab8 and Rab10 GTPases that are responsible for GLUT4 vesicle fusion to the membrane.. Collectively, our study reports that GLP-1 mediates the insulinotropic activity of [6]-Gingerol, and [6]-Gingerol treatment facilitates glucose disposal in skeletal muscles through increased activity of glycogen synthase 1 and enhanced cell surface presentation of GLUT4 transporters. Topics: Animals; Blood Glucose; Catechols; Diabetes Mellitus, Type 2; Fatty Alcohols; Glucagon-Like Peptide 1; Glucose Transporter Type 4; Glycogen; Glycogen Synthase; Hyperglycemia; Insulin; Insulin Secretion; Insulin-Secreting Cells; Membrane Proteins; Mice; Mice, Inbred NOD; Mice, Knockout; Muscle, Skeletal; Phytotherapy; Plant Extracts; rab GTP-Binding Proteins; Secretory Pathway; Vesicular Transport Proteins; Zingiber officinale | 2017 |
Differential Effects of Linagliptin on the Function of Human Islets Isolated from Non-diabetic and Diabetic Donors.
Linagliptin is a dipeptidyl Peptidase-4 (DPP-4) inhibitor that inhibits the degradation of glucagon-like peptide 1 (GLP-1), and has been approved for the treatment of type 2 diabetes (T2D) in clinic. Previous studies have shown linagliptin improves β cell function using animal models and isolated islets from normal subjects. Since β cell dysfunction occurs during diabetes development, it was not clear how human islets of T2D patients would respond to linagliptin treatment. Therefore, in this study we employed human islets isolated from donors with and without T2D and evaluated how they responded to linagliptin treatment. Our data showed that linagliptin significantly improved glucose-stimulated insulin secretion for both non-diabetic and diabetic human islets, but its effectiveness on T2D islets was lower than on normal islets. The differential effects were attributed to reduced GLP-1 receptor expression in diabetic islets. In addition, linagliptin treatment increased the relative GLP-1 vs glucagon production in both non-diabetic and diabetic islets, suggesting a positive role of linagliptin in modulating α cell function to restore normoglycemia. Our study indicated that, from the standpoint of islet cell function, linagliptin would be more effective in treating early-stage diabetic patients before they develop severe β cell dysfunction. Topics: Cells, Cultured; Diabetes Mellitus, Type 2; Dipeptidyl-Peptidase IV Inhibitors; Glucagon; Glucagon-Like Peptide 1; Glucagon-Like Peptide-1 Receptor; Glucagon-Secreting Cells; Humans; Hypoglycemic Agents; Insulin Secretion; Insulin-Secreting Cells; Linagliptin | 2017 |
COMPARING CLINICAL OUTCOMES AND COSTS FOR DIFFERENT TREATMENT INTENSIFICATION APPROACHES IN PATIENTS WITH TYPE 2 DIABETES UNCONTROLLED ON BASAL INSULIN: ADDING GLUCAGON-LIKE PEPTIDE 1 RECEPTOR AGONISTS VERSUS ADDING RAPID-ACTING INSULIN OR INCREASING BASA
Not all patients with type 2 diabetes achieve recommended glycated hemoglobin A. This retrospective analysis of health insurance claims data in the U.S. MarketScan database compared glycemic control and healthcare resource utilization and costs 12 months after adding a GLP-1 RA to BI versus adding a RAI or increasing BI doses. Propensity score matching was used in the comparative effectiveness analysis.. A total of 8,034 patients underwent treatment intensification within 6 months of showing poor glycemic control; 4,134 patients had their BI dose adjusted, and 2,076 and 331 received RAI and GLP-1 RA, respectively. A1C changes were similar for the GLP-1 RA and RAI cohorts but higher for the GLP-1 RA versus the dose-adjustment group. The hypoglycemia rate was lower after adding GLP-1 RA versus RAI or increasing BI dose. No overall changes in utilization of healthcare resources or diabetes-related costs were observed between intensification strategies, although prescription costs were higher for the GLP-1 RA cohort.. BI in combination with GLP-1 RAs appears to be an effective intensification strategy, further reducing A1C levels and hypoglycemia frequency compared to increasing BI doses. GLP-1 RA addition also decreases hypoglycemia frequency versus BI dose increases and RAI addition, without raising overall healthcare costs.. A1C = hemoglobin A Topics: Aged; Diabetes Mellitus, Type 2; Female; Glucagon-Like Peptide 1; Glycated Hemoglobin; Health Care Costs; Humans; Insulin; Male; Middle Aged; Propensity Score; Retrospective Studies | 2017 |
Roles of increased glycaemic variability, GLP-1 and glucagon in hypoglycaemia after Roux-en-Y gastric bypass.
Roux-en-Y gastric bypass (RYGB) surgery is currently the most effective treatment for diabetes and obesity. An increasingly recognized and highly disabling complication of RYGB is postprandial hypoglycaemia (PPH). The pathophysiology of PPH remains unclear with multiple mechanisms suggested including nesidioblastosis, altered insulin clearance and increased glucagon-like peptide-1 (GLP-1) secretion. Whilst many PPH patients respond to dietary modification, some have severely disabling symptoms. Multiple treatments are proposed, including dietary modification, GLP-1 antagonism, GLP-1 analogues and even surgical reversal, with none showing a more decided advantage over the others. A greater understanding of the pathophysiology of PPH could guide the development of new therapeutic strategies.. We studied a cohort of PPH patients at the Imperial Weight Center. We performed continuous glucose monitoring to characterize their altered glycaemic variability. We also performed a mixed meal test (MMT) and measured gut hormone concentrations.. We found increased glycaemic variability in our cohort of PPH patients, specifically a higher mean amplitude glucose excursion (MAGE) score of 4.9. We observed significantly greater and earlier increases in insulin, GLP-1 and glucagon in patients who had hypoglycaemia in response to an MMT (MMT Hypo) relative to those that did not (MMT Non-Hypo). No significant differences in oxyntomodulin, GIP or peptide YY secretion were seen between these two groups.. An early peak in GLP-1 and glucagon may together trigger an exaggerated insulinotropic response to eating and consequent hypoglycaemia in patients with PPH. Topics: Blood Glucose; Cohort Studies; Combined Modality Therapy; Diabetes Mellitus, Type 2; Diet, Diabetic; Diet, Reducing; Female; Gastric Bypass; Glucagon; Glucagon-Like Peptide 1; Humans; Hypoglycemia; Insulin; Insulin Secretion; London; Male; Middle Aged; Monitoring, Ambulatory; Obesity; Postoperative Complications; Postprandial Period; Prevalence; Risk Factors | 2017 |
Oral delivery of a therapeutic gene encoding glucagon-like peptide 1 to treat high fat diet-induced diabetes.
The number of people suffering from insulin-independent type 2 diabetes mellitus (T2DM) is ever increasing on a yearly basis. Current anti-diabetic medications often result in adverse weight gain and hypoglycemic episodes. Hypoglycemia can be avoided with glucagon-like peptide (GLP)-1 receptor agonists, which are expensive and require daily injections that may result immune activation. This study demonstrates the use of non-viral vector based oral delivery of GLP-1 gene through enterohepatic recycling pathways of bile acids. Oral administration of the plasmid DNA (pDNA) encoding GLP-1 decreased diabetic glucose levels to the normoglycemic range with significant weight reduction in a high-fat diet (HFD) induced diabetic mouse model and a genetically engineered T2DM rat model. This novel oral GLP1 delivery system is an attractive alternative to treat late-stage T2DM conditions that require repeated insulin injection and can potentially minimize the occurrence of hypoglycemic anomalies. Topics: Animals; Cell Line; Diabetes Mellitus, Type 2; Diet, High-Fat; DNA; Female; Gene Transfer Techniques; Genetic Therapy; Glucagon-Like Peptide 1; Heparin; Humans; Male; Mice; Mice, Inbred C57BL; Rats, Sprague-Dawley; Rats, Zucker; Taurocholic Acid | 2017 |
Incretins and Their Endocrine and Metabolic Functions.
Incretins are hormones secreted into the blood stream from the gut mucosa in response to nutrient intake. They have been characterized based on their capacity to lower blood glucose levels. The more potent reduction of blood glucose coupled to a more intensive stimulation of insulin secretion, in response to oral glucose uptake, as compared to intravenous glucose infusion has further been termed the "incretin effect." As a prototype incretin hormone, the biology of glucagon-like peptide 1 (GLP-1) has been intensively studied. GLP-1 actions are mediated through cyclic adenosine monophosphate-coupled membrane receptors. Classical physiological effects involve stimulation of insulin secretion from pancreatic beta cells and reduction of glucagon secretion from pancreatic alpha cells, inhibition of gastric motility, and increase of satiety with reduced food uptake. The understanding of these metabolic functions has led to the notion that incretin hormones, and specifically GLP-1, would represent ideal antidiabetic treatment options. As native GLP-1 is degraded by dipeptidyl peptidase type 4 (DPP-4) within minutes, other pharmacological approaches to exploit GLP-1 actions for the treatment of type 2 diabetes have been developed. These include DPP-4 inhibitors as oral medications and GLP-1 receptor agonists (incretin mimetics) as peptide compounds to be injected. Topics: Blood Glucose; Diabetes Mellitus, Type 2; Dipeptidyl Peptidase 4; Dipeptidyl-Peptidase IV Inhibitors; Gastrointestinal Tract; Glucagon; Glucagon-Like Peptide 1; Glucagon-Like Peptide-1 Receptor; Glucagon-Secreting Cells; Glucose; Humans; Hypoglycemic Agents; Incretins; Insulin; Insulin Secretion; Insulin-Secreting Cells | 2017 |
Glucagon-Like Peptide-1 (GLP-1) Treatment Ameliorates Cognitive Impairment by Attenuating Arc Expression in Type 2 Diabetic Rats.
BACKGROUND Glucagon-like peptide-1 (GLP-1) has been reported to exert some beneficial effects on the central nervous system (CNS). However, the effect of GLP-1 on cognitive impairment associated with type 2 diabetes is not well known. This study investigated the effect of GLP-1 on ameliorating memory deficits in type 2 diabetic rats. MATERIAL AND METHODS Type 2 diabetic rats were induced by a high-sugar, high-fat diet, followed by streptozotocin (STZ) injection and then tested in the Morris Water Maze (MWM) 1 week after the induction of diabetes. The mRNA expression of Arc, APP, BACE1, and PS1 were determined by real-time quantitative PCR, and the Arc protein was analyzed by immunoblotting and immunohistochemistry. RESULTS Type 2 diabetic rats exhibited a significant decline in learning and memory in the MWM tests, but GLP-1 treatment was able to protect this decline and significantly improved learning ability and memory. The mRNA expression assays showed that GLP-1 treatment markedly reduced Arc, APP, BACE1, and PS1 expressions, which were elevated in the diabetic rats. Immunoblotting and immunohistochemistry results also confirmed that Arc protein increased in the hippocampus of diabetic rats, but was reduced after GLP-1 treatment. CONCLUSIONS Our findings suggest that GLP-1 treatment improves learning and memory deficits in type 2 diabetic rats, and this effect is likely through the reduction of Arc expression in the hippocampus. Topics: Animals; Blood Glucose; Cognitive Dysfunction; Cytoskeletal Proteins; Diabetes Mellitus, Experimental; Diabetes Mellitus, Type 2; Diet, High-Fat; Disease Models, Animal; Glucagon-Like Peptide 1; Hippocampus; Male; Maze Learning; Memory Disorders; Nerve Tissue Proteins; Rats; Rats, Sprague-Dawley | 2017 |
Association of TCM body constitution with insulin resistance and risk of diabetes in impaired glucose regulation patients.
Impaired glucose regulation (IGR) patients have increased risk of type 2 diabetes mellitus (T2DM). Identifying relevant risk factors in IGR subjects could facilitate early detection and prevention of IGR progression to diabetes. This study investigated the association between Traditional Chinese Medicine (TCM) body constitution and serum cytokines, and whether body constitution could independently predict diabetes in IGR subjects.. Patients with IGR (n = 306) received a blood test and their body constitution type was assessed using a body constitution questionnaire (BCQ). Serum levels of cytokines were measured by ELISA. Patients were followed up for at least three years, and their status of diabetes were recorded. Multivariate logistic regression was used to estimate odds ratios (ORs) of diabetes for body constitution.. Phlegm-damp, Damp-heat and Qi-deficiency were three most common unbanlenced constitutions among IGR subjects. Phlegm-damp and Damp-heat constitution subjects showed higher serum levels of interleukin 6 (IL-6), tumour necrosis factor-α (TNF-α), leptin and lower serum levels of adiponectin (P<0.05). Qi-deficiency constitution subjects showed higher serum levels of leptin and lower serum levels of adiponectin, glucagon-like peptide-1 (GLP-1) and gastric inhibitory polypeptide (GIP) (P<0.05). Subjects with Phlegm-damp or Damp-heat constitution demonstrated a significantly higher risk of diabetes (P<0.05).. Phlegm-damp and Damp-heat TCM body constitution are strongly associated with abnormal serum cytokines, and could potentially serve as a predictor of diabetes in IGR subjects. Body constitution can help to identify IGR subjects who are at a high risk of progression to diabetes. Topics: Adiponectin; Cytokines; Diabetes Mellitus, Type 2; Female; Gastric Inhibitory Polypeptide; Glucagon-Like Peptide 1; Humans; Insulin Resistance; Leptin; Male; Medicine, Chinese Traditional; Middle Aged; Prospective Studies; Surveys and Questionnaires | 2017 |
Micellar Nanomedicine of Novel Fatty Acid Modified Xenopus Glucagon-like Peptide-1: Improved Physicochemical Characteristics and Therapeutic Utilities for Type 2 Diabetes.
To develop novel long-acting antidiabetics with improved therapeutic efficacy, two glucagon-like peptide-1 (GLP-1) analogs were constructed through the hybridization of key sequences of GLP-1, xenGLP-1B, exendin-4, and lixisenatide. Hybrids 1 and 2 demonstrated enhanced in vitro and in vivo biological activities and were further site-specifically lipidized at lysine residues to achieve prolonged duration of action and less frequent administration. Compared with their native peptides, compounds 3-6 showed similar in vitro activities but impaired in vivo acute hypoglycemic potencies due to decreased aqueous solubility and retarded absorption in vivo. To circumvent these issues, compound 3 (xenoglutide) was selected to be self-associated with sterically stabilized micelles (SSM). The α-helix and solubility of xenoglutide were significantly improved after self-associated with SSM. Notably, the improved physicochemical characteristics of xenoglutide-SSM led to revival of acute hypoglycemic ability without affecting its long-term glucose-lowering activity. Most importantly, preclinical studies demonstrated improved therapeutic effects and safety of xenoglutide-SSM in diabetic db/db mice. Our work suggests the SSM incorporation as an effective approach to improve the pharmacokinetic and biological properties of hydrophobicity peptide drugs. Furthermore, our data clearly indicate xenoglutide-SSM as a novel nanomedicine for the treatment of type 2 diabetics. Topics: Animals; Cell Line; Cell Survival; Diabetes Mellitus, Type 2; Eating; Exenatide; Fatty Acids; Glucagon-Like Peptide 1; Glucose Tolerance Test; Humans; Hypoglycemic Agents; Liraglutide; Male; Mice; Micelles; Nanomedicine; Peptides; Venoms | 2017 |
The relationship between bile acid concentration, glucagon-like-peptide 1, fibroblast growth factor 15 and bile acid receptors in rats during progression of glucose intolerance.
Recent studies show that bile acids are involved in glucose and energy homeostasis through activation of G protein coupled membrane receptor (TGR5) and farnesoid X receptor (FXR). A few researches have explored changes of TGR5 and FXR in animals with impaired glucose regulation. This study aimed to observe changes of plasma total bile acids (TBA), glucagon-like-peptide 1 (GLP-1), fibroblast growth factor 15 (FGF15), intestinal expressions of TGR5 and FXR, and correlations between them in rats with glucose intolerance.. Besides plasma fasting glucose, lipid, TBAs, alanine transaminase (ALT), active GLP-1(GLP-1A) and FGF15, a postprandial meal test was used to compare responses in glucose, insulin and GLP-1A among groups. The expressions of TGR5 and FXR in distal ileum and ascending colon were quantified by real-time PCR and western blot.. TGR5 expression was significantly decreased in distal ileum in DM group compared to other groups, and TGR5 and FXR expressions in ascending colon were also decreased in DM group compared to other groups. Correlation analysis showed correlations between TBA and GLP-1A or FGF15. GLP-1A was correlated with TGR5 mRNA expression in colon, and FGF15 was correlated with FXR mRNA expression in colon.. These results indicates that bile acid-TGR5/FXR axis contributes to glucose homeostasis. Topics: Animals; Bile Acids and Salts; Diabetes Mellitus, Experimental; Diabetes Mellitus, Type 2; Diet, High-Fat; Disease Progression; Fibroblast Growth Factors; Glucagon-Like Peptide 1; Glucose Intolerance; Intestinal Mucosa; Liver Diseases; Male; Rats; Receptors, Cytoplasmic and Nuclear; Receptors, G-Protein-Coupled | 2017 |
Vildagliptin increases butyrate-producing bacteria in the gut of diabetic rats.
Emerging evidence supports a key role for the gut microbiota in metabolic diseases, including type 2 diabetes (T2D) and obesity. The dipeptidyl peptidase-4 inhibitor vildagliptin is highly efficacious in treating T2D. However, whether vildagliptin can alter the gut microbiome is still unclear. This study aimed to identify whether vildagliptin modifies the gut microbiota structure during T2D treatment. Diabetic Sprague-Dawley (SD) rats were induced by a high-fat diet and streptozotocin injection (HFD/STZ). Diabetic rats were orally administered a low dose of vildagliptin (LV, 0.01 g/kg/d vildagliptin), high dose of vildagliptin (HV, 0.02 g/kg/d vildagliptin), or normal saline for 12 weeks. Fasting blood glucose, blood glucose after glucose loading, and serum insulin levels were significantly reduced in the LV and HV groups compared with those in the T2D group. The serum GLP-1 level increased more in the vildagliptin-treated group than in the T2D group. Pyrosequencing of the V3-V4 regions of 16S rRNA genes revealed that vildagliptin significantly altered the gut microbiota. The operational taxonomic units (OTUs) and community richness (Chao1) index were significantly reduced in the vildagliptin and diabetic groups compared with those in the control group. At the phylum level, a higher relative abundance of Bacteroidetes, lower abundance of Firmicutes, and reduced ratio of Fimicutes/Bacteroidetes were observed in the vildagliptin-treated group. Moreover, vildagliptin treatment increased butyrate-producing bacteria, including Baceroides and Erysipelotrichaeae, in the diabetic rats. Moreover, Lachnospira abundance was significantly negatively correlated with fasting blood glucose levels. In conclusion, vildagliptin treatment could benefit the communities of the gut microbiota. Topics: Adamantane; Administration, Oral; Animals; Blood Glucose; Butyrates; Diabetes Mellitus, Experimental; Diabetes Mellitus, Type 2; Dipeptidyl-Peptidase IV Inhibitors; Gastrointestinal Microbiome; Glucagon-Like Peptide 1; Insulin Resistance; Interleukin-6; Male; Nitriles; Pyrrolidines; Random Allocation; Rats, Sprague-Dawley; RNA, Ribosomal, 16S; Vildagliptin | 2017 |
Activation of intestinal olfactory receptor stimulates glucagon-like peptide-1 secretion in enteroendocrine cells and attenuates hyperglycemia in type 2 diabetic mice.
Odorants are non-nutrients. However, they exist abundantly in foods, wines, and teas, and thus can be ingested along with the other nutrients during a meal. Here, we have focused on the chemical-recognition ability of these ORs and hypothesized that the odorants ingested during a meal may play a physiological role by activating the gut-expressed ORs. Using a human-derived enteroendocrine L cell line, we discovered the geraniol- and citronellal-mediated stimulation of glucagon-like peptide-1 (GLP-1) secretion and elucidated the corresponding cellular downstream signaling pathways. The geraniol-stimulated GLP-1 secretion event in the enteroendocrine cell line was mediated by the olfactory-type G protein, the activation of adenylyl cyclase, increased intracellular cAMP levels, and extracellular calcium influx. TaqMan qPCR demonstrated that two ORs corresponding to geraniol and citronellal were expressed in the human enteroendocrine cell line and in mouse intestinal specimen. In a type 2 diabetes mellitus mouse model (db/db), oral administration of geraniol improved glucose homeostasis by increasing plasma GLP-1 and insulin levels. This insulinotropic action of geraniol was GLP-1 receptor-mediated, and also was glucose-dependent. This study demonstrates that odor compounds can be recognized by gut-expressed ORs during meal ingestion and therefore, participate in the glucose homeostasis by inducing the secretion of gut-peptides. Topics: Animals; Blood Glucose; Diabetes Mellitus, Experimental; Diabetes Mellitus, Type 2; Enteroendocrine Cells; Glucagon-Like Peptide 1; Hyperglycemia; Intestinal Mucosa; Male; Mice; Mice, Inbred C57BL; Receptors, Odorant | 2017 |
Measurement of Gastrointestinal Hormones.
Towards the end of the 20th century, the number of subjects with diabetes and obesity rose exponentially. The discoveries of insulin- and appetite-modulating chemical signals, including glucagon-like peptide-1 (GLP-1), secreted from the gastrointestinal system, led to development of a new group of drugs which now are being used for glucose-lowering therapy and weight loss. Understanding of the physiology of gut derived signals and their pathophysiologi-cal importance requires accurate measurements of their circulat-ing levels. However, the assessment of these gut-derived hor-mones has been hampered by numerous preanalytical and analyti-cal challenges. We focused on three members of the proglucagon family; glucagon, oxyntomodulin and GLP-1, aiming to meet both preanalytical and analytical challenges and to elucidate their implication in diseases including diabetes. First, we studied (Study 1) the preanalytical and storage conditions of GLP-1 and glucagon in humans, demonstrating that inappropriate sample handling may cause up to 50% variation in the RESULTS. Using robust meas-uring METHODS ensuring optimal conditions for preanalytical han-dling of these peptides, we then focused on plasma concentra-tions of glucagon and oxyntomodulin in different clinical condi-tions, including type 2 diabetes and bariatric surgery, because abnormal secretion of these hormones may represent early and specific signs of altered glucose metabolism. To that end, we developed an unbiased mass-spectrometry based platform for detection of low-abundant peptides, including the gut hormones (Study 2). Using the platform, we validated a new method for the measurement of oxyntomodulin, and in a series of in vitro, ex vivo, and clinical studies, we demonstrated that oxyntomodulin is co-distributed and co-secreted in response to glucose with GLP-1 and is degraded by dipeptidyl peptidase 4. Because oxyntomodulin has both GLP-1-like and glucagon-like bioactivity, the secretion of this hormone is of interest in both type 2 diabetes and bariatric sur-gery. Furthermore, using these newly developed METHODS, we subsequently were able to establish that elevated plasma concen-trations of glucagon (hyperglucagonemia) in diseases (Study 3) may be due to either a) increased secretion of fully processed glucagon, as in subjects with diabetes or b) secretion of N-terminally elongated molecular forms (Study 4) in conditions including bariatric surgery and in diseases affecting the kidneys. This glucag Topics: Bariatric Surgery; Diabetes Mellitus, Type 2; Glucagon; Glucagon-Like Peptide 1; Humans; Mass Spectrometry; Neuropeptides; Obesity; Oxyntomodulin; Specimen Handling | 2017 |
Glucagon-Like Peptide-1 (GLP-1) Receptor Agonist Liraglutide Alters Bone Marrow Exosome-Mediated miRNA Signal Pathways in Ovariectomized Rats with Type 2 Diabetes.
BACKGROUND Compared with normal postmenopausal women, estrogen deficiency and hyperglycemia in postmenopausal women with type 2 diabetes (T2DM) lead to more severe bone property degradation. Liraglutide, a glucagon-like peptide-1 (GLP-1) receptor agonist, has been reported to improve bone condition among people with T2DM but the precise mechanisms remain unclear. Exosomes work as mediators in cell-to-cell communication, delivering functional miRNAs between cells. We aimed to explore the role of exosomes in T2DM-related bone metabolic disorders and the bone protective mechanisms of liraglutide. MATERIAL AND METHODS We made comparative analyses of bone marrow-derived exosomal miRNAs from ovariectomized (OVX) control rats, OVX + T2DM rats, and OVX + T2DM + liraglutide-treated rats. miRNA profiles were generated using high-throughput sequencing. Target gene prediction and pathway analysis were performed to investigate the signal pathway alterations. Three miRNAs were randomly chosen to validate their absolute expression levels by real-time quantitative PCR. RESULTS Bone marrow-derived exosomal miRNAs were different with respect to miRNA numbers, species, and expression levels. miRNA spectra varied under T2DM condition and after liraglutide treatment. By bioinformatics analysis, we found T2DM and liraglutide administration lead to significant changes in exosomal miRNAs which targeted to insulin secretion and insulin-signaling pathway. Wnt signaling pathway alteration was the critical point regarding bone metabolism. CONCLUSIONS Our findings show the selective packaging of functional miRNA cargoes into exosomes due to T2DM and liraglutide treatment. Bone marrow exosome-mediated Wnt signaling pathway alteration may play a part in the bone protective effect of liraglutide. Topics: Animals; Blood Glucose; Bone Marrow; Diabetes Mellitus, Type 2; Disease Models, Animal; Exosomes; Female; Glucagon-Like Peptide 1; Glucagon-Like Peptide-1 Receptor; Hyperglycemia; Hypoglycemic Agents; Insulin; Liraglutide; MicroRNAs; Ovariectomy; Rats; Rats, Sprague-Dawley; Signal Transduction; Transcriptome | 2017 |
Liraglutide and Renal Outcomes in Type 2 Diabetes.
Topics: Diabetes Mellitus, Type 2; Glucagon-Like Peptide 1; Humans; Hypoglycemic Agents; Kidney; Liraglutide | 2017 |
NUTRITIONAL INSULIN OR GLP-1 RECEPTOR AGONIST: CROSSROADS IN THE TREATMENT OF TYPE 2 DIABETES MELLITUS.
Topics: Blood Glucose; Diabetes Mellitus, Type 2; Glucagon-Like Peptide 1; Glucagon-Like Peptide-1 Receptor; Humans; Hypoglycemic Agents; Insulin | 2017 |
Characterization of Optimized Functional-Complementary Dual Insulinotorpic Peptide rolGG.
Glucagon-like peptide-1 (GLP-1) and gastric inhibitory polypeptide (GIP) play a similar but complementary role in the regulation of glucose levels in islet β-cells. This study was aimed to develop a fusion peptide, which combines 4 tandem repeated GLP-1 and 4 tandem repeated GIP (4rolGG), and to investigate its therapeutic effect on type 2 diabetes using a diabetic mice model.. A 4rolGG expression plasmid was constructed and expressed in BL21 (DE3). By inducting with IPTG, 4rolGG was expressed at a high level, which was confirmed by SDS-PAGE electrophoresis and Western Blotting. Subsequently, 4rolGG was purified by Ni-NTA affinity chromatography and the purity of 4rolGG was up to 90%.. After oral administration of 4rolGG for 4 weeks, streptozotocin-induced diabetic mice showed a dramatic reduction in the levels of plasma glucose, GHbA1C, TC and TG, while the insulin levels were increased significantly. Topics: Administration, Oral; Amino Acid Sequence; Animals; Blood Glucose; Diabetes Mellitus, Experimental; Diabetes Mellitus, Type 2; Gastric Inhibitory Polypeptide; Glucagon-Like Peptide 1; Humans; Insulin; Male; Mice; Mice, Inbred C57BL; Peptide Fragments; Plasmids; Protein Engineering | 2017 |
Liraglutide and Renal Outcomes in Type 2 Diabetes.
Topics: Diabetes Mellitus, Type 2; Glucagon-Like Peptide 1; Glycated Hemoglobin; Humans; Hypoglycemic Agents; Kidney; Liraglutide | 2017 |
Gastric bypass procedure for type 2 diabetes patients with BMI <28 kg/m
To evaluate the Roux-en-Y gastric bypass (GBP) procedure for patients suffering from type 2 diabetes mellitus (T2DM) with body mass index (BMI) <28 kg/m. Thirty-one patients suffering from T2DM were selected to undergo laparoscopic Roux-en-Y gastric bypass surgery and were enrolled at Beijing Shijitan Hospital between November 2012 and December 2014. The fasting plasma glucose (FPG), glycosylated hemoglobin (HbA1c), C-peptide, fasting insulin (FINS) and glucagon-like peptide-1 (GLP-1) of all patients were measured before and at 1, 3, 6 months after surgery. The results were compared and analyzed.. Thirty-one patients suffering from T2DM successfully underwent GBP surgery (a mean age of 46 years), 14 were male and 17 were female. Among them, 7 patients had hypertriglyceridemia (HTG). The patients were followed up for 6 months. No major complications were found. The average BMI was 26.5 ± 1.4 kg/m. This research shows that the GBP procedure is safe and effective for T2DM patients with BMI <28 kg/m Topics: Adult; Aged; Body Mass Index; C-Peptide; Diabetes Mellitus, Type 2; Female; Follow-Up Studies; Gastric Bypass; Glucagon-Like Peptide 1; Glycated Hemoglobin; Humans; Insulin; Laparoscopy; Male; Middle Aged; Remission Induction; Triglycerides; Weight Loss; Young Adult | 2017 |
Influence of New Modified Biliopancreatic Diversion on Blood Glucose and Lipids in GK rats.
This study aimed to investigate the influence of new biliopancreatic diversion (NBPD) and duodenal-jejunal bypass (DJB) surgery on blood glucose, lipids, gastrointestinal hormones, and insulin in Goto-Kakizaki (GK) rats, an animal model for type 2 diabetes, in order to elucidate the mechanisms underlying the therapeutic effect of these types of surgery on this clinical condition.. Thirty 30 male GK rats (SPF) aged 12 weeks were randomly assigned into three groups (n = 10 per group): sham group, NBPD group, and DJB group. Body weight, random plasma glucose, fasting plasma glucose (FPG), oral glucose tolerance (OGT), blood lipids, plasma insulin, glucagon like peptide-1 (GLP-1), and gastric inhibitory polypeptide (GIP) were measured before and after surgery.. NBPD surgery improved glucose tolerance, decreased fasting free fatty acids, triglycerides, and cholesterol. It also increased fasting and postprandial GIP, but caused no change in GLP-1. DJB surgery produced results similar to NBPD surgery except for causing a decrease in postprandial GLP-1 and insulin, and a larger increase in fasting GIP.. Moving the biliopancreatic duct outlet to the mid-jejunum (NBPD surgery) improves glucose tolerance and increases GIP, but does not change GLP-1. Adding duodenal bypass (DJB surgery) increases fasting GIP and decreases postprandial GLP-1. Topics: Animals; Biliopancreatic Diversion; Blood Glucose; Diabetes Mellitus, Experimental; Diabetes Mellitus, Type 2; Duodenum; Gastric Bypass; Gastric Inhibitory Polypeptide; Glucagon-Like Peptide 1; Glucose Tolerance Test; Insulin; Insulin Resistance; Jejunum; Lipid Metabolism; Lipids; Male; Rats | 2017 |
Pharmacological Effects and Pharmacokinetic Properties of a Dual-Function Peptide 5rolGLP-HV.
In order to better understand the therapeutic mechanism of dual-function peptide 5rolGLP-HV in treatment of treat diabetes and its complication of thrombosis, the pharmacological effects and pharmacokinetic properties of 5rolGLP-HV were conducted in this study. 5rolGLP-HV was orally administered to diabetic mice, and the hypoglycemic mechanism was investigated. Thrombotic mice were applied to study the thrombus dissolving ability of 5rolGLP-HV. The concentration of rolGLP and rHV in rat plasma following single oral dose or intravenous injection of 5rolGLP-HV was measured. Treatment with 5rolGLP-HV decreased insulin resistance (2.96 ± 1.43 vs. 9.35 ± 1.51, p < 0.05) of diabetic mice. 5rolGLP-HV shortened the length of thrombus in thrombosis mice (2.92 ± 0.74 vs. 5.92 ± 1.16 cm, p < 0.01) and extended the thrombin time (15.35 ± 1.22 vs. 8.67 ± 0.89 s, p < 0.01) of normal mice. Meanwhile, 5rolGLP-HV restored the damage of pancreatic, liver, kidney, and adipose tissues induced in the diabetic mice. 5rolGLP-HV exhibited a fast absorption and slow elimination phase after digested into rolGLP-1 and rHV in vivo. These results suggested that 5rolGLP-HV had an ideal therapeutic potential in the prevention of β cell dysfunction in type 2 diabetes and delay of the thrombus. Topics: Administration, Oral; Animals; Diabetes Mellitus, Type 2; Drug Combinations; Fibrinolytic Agents; Glucagon-Like Peptide 1; Hirudins; Hypoglycemic Agents; Male; Metabolic Clearance Rate; Mice; Mice, Inbred C57BL; Rats; Rats, Sprague-Dawley; Recombinant Fusion Proteins; Thrombosis; Treatment Outcome | 2017 |
Combination therapy with GLP-1 analogues and SGLT-2 inhibitors in the management of diabesity: the real world experience.
Diabesity-obesity resulting in diabetes-is a major health problem globally because of the obesity epidemic. Several anti-diabetic medications cause weight gain and may worsen obesity, and possibly diabeisty. Two recent small retrospective cohort studies showed weight loss and diabetes improvement with combination of glucagon-like peptide-1 (GLP-1) agonists and sodium-glucose co-transporter type-2 (SGLT-2) inhibitors in obese subjects. We assessed the effect of combination therapy with GLP-1 agonists and SGLT-2 inhibitors in the management of diabesity in a retrospective study at the Wolverhampton Diabetes Centre. Out of 79 patients on this combination regimen with other anti-diabetic medications, 37 cases who had follow up at 3-6 months were studied. Mean age and duration of follow up were 57.4 (+/-7.8) and 139 (+/-32.6) days, respectively. Twenty-two patients (59.5 %) were Asians. Statistically significant improvements in clinical parameters such as body weight reduction (3.07 kg), glycated haemoglobin (HbA1c) reduction (1.05 %), lower BMI (-1.13 kg/M Topics: Aged; Blood Glucose; Diabetes Mellitus, Type 2; Drug Therapy, Combination; Female; Glucagon-Like Peptide 1; Humans; Hypoglycemic Agents; Insulin; Insulin Resistance; Male; Middle Aged; Obesity; Retrospective Studies; Sodium-Glucose Transporter 2; Treatment Outcome; Weight Loss | 2017 |
The impact of EndoBarrier gastrointestinal liner in obese patients with normal glucose tolerance and in patients with type 2 diabetes.
The duodenal-jejunal bypass sleeve ((DJBS) or EndoBarrier Gastrointestinal Liner) induces weight loss in obese subjects and may improve glucose homeostasis in patients with type 2 diabetes (T2D). To explore the underlying mechanisms, we evaluated postprandial physiology including glucose metabolism, gut hormone secretion, gallbladder emptying, appetite and food intake in patients undergoing DJBS treatment.. A total of 10 normal glucose-tolerant (NGT) obese subjects and 9 age-, body weight- and body mass index-matched metformin-treated T2D patients underwent a liquid mixed meal test and a subsequent ad libitum meal test before implantation with DJBS and 1 week (1w) and 26 weeks (26w) after implantation.. At 26w, both groups had achieved a weight loss of 6 to 7 kg. Postprandial glucagon-like peptide-1 (GLP-1) and peptide YY responses increased at 1w and 26w, but only in T2D subjects. In contrast, glucose-dependent insulinotropic polypeptide responses were reduced only by DJBS in the NGT group. Postprandial glucose, insulin, C-peptide, glucagon, cholecystokinin and gastrin responses were unaffected by DJBS in both groups. Satiety and fullness sensations were stronger and food intake was reduced at 1w in NGT subjects; no changes in appetite measures or food intake were observed in the T2D group. No effect of DJBS on postprandial gallbladder emptying was observed, and gastric emptying was not delayed.. DJBS-induced weight loss was associated with only marginal changes in postprandial physiology, which may explain the absence of effect on postprandial glucose metabolism. Topics: Adult; Appetite; Bariatric Surgery; Blood Glucose; Body Composition; C-Peptide; Case-Control Studies; Cholecystokinin; Comorbidity; Diabetes Mellitus, Type 2; Eating; Female; Gallbladder Emptying; Gastric Emptying; Gastric Inhibitory Polypeptide; Gastrins; Glucagon-Like Peptide 1; Glycated Hemoglobin; Humans; Insulin; Male; Middle Aged; Obesity; Peptide YY; Postprandial Period; Prospective Studies; Satiety Response; Treatment Outcome | 2017 |
Associations between changes in glucagon-like peptide-1 and bodyweight reduction in patients receiving acarbose or metformin treatment.
The present post hoc analysis investigated whether changes in endogenous glucagon-like peptide-1 (∆GLP-1) levels are associated with weight loss in newly diagnosed diabetes patients.. In all, 784 subjects from the Metformin and AcaRbose in Chinese as initial Hypoglycemic treatment (MARCH) study were stratified according to ∆GLP-1. Changes in clinical and physiological parameters were evaluated across ∆GLP-1 subgroups (low, medium, and high) to assess correlations between ∆GLP-1 and weight loss in acarbose- versus metformin-treated groups.. Changes in GLP-1 levels are associated with weight loss in newly diagnosed Chinese diabetes patients receiving acarbose. Topics: Acarbose; Adult; Aged; Blood Glucose; Diabetes Mellitus, Type 2; Female; Glucagon; Glucagon-Like Peptide 1; Glycated Hemoglobin; Humans; Hypoglycemic Agents; Insulin; Male; Metformin; Middle Aged; Patient Education as Topic; Weight Loss | 2017 |
Incretin treatment and atherosclerotic plaque stability: Role of adiponectin/APPL1 signaling pathway.
Glucagon like peptide 1 (GLP-1) analogues and dipeptidyl peptidase IV (DPP-4) inhibitors reduce atherosclerosis progression in type 2 diabetes mellitus (T2DM) patients and are associated with morphological and compositional characteristics of stable plaque phenotype. GLP-1 promotes the secretion of adiponectin which exerts anti-inflammatory effects through the adaptor protein PH domain and leucine zipper containing 1 (APPL1). The potential role of APPL1 expression in the evolution of atherosclerotic plaque in TDM2 patients has not previously evaluated.. The effect of incretin therapy in the regulation of adiponectin/APPL1 signaling was evaluated both on carotid plaques of asymptomatic diabetic (n=71) and non-diabetic patients (n=52), and through in vitro experiments on endothelial cell (EC).. Atherosclerotic plaques of T2DM patients showed lower adiponectin and APPL1 levels compared with non-diabetic patients, along with higher oxidative stress, tumor necrosis factor-α (TNF-α), vimentin, and matrix metalloproteinase-9 (MMP-9) levels. Among T2DM subjects, current incretin-users presented higher APPL1 and adiponectin content compared with never incretin-users. Similarly, in vitro observations on endothelial cells co-treated with high-glucose (25mM) and GLP-1 (100nM) showed a greater APPL1 protein expression compared with high-glucose treatment alone.. Our findings suggest a potential role of adiponectin/APPL1 signaling in mediating the effect of incretin in the prevention of atherosclerosis progression or plaque vulnerability in T2DM. Topics: Adaptor Proteins, Signal Transducing; Adiponectin; Aged; Anti-Inflammatory Agents, Non-Steroidal; Antioxidants; Carotid Stenosis; Cells, Cultured; Diabetes Mellitus, Type 2; Diabetic Angiopathies; Endarterectomy, Carotid; Endothelium, Vascular; Female; Glucagon-Like Peptide 1; Humans; Incretins; Italy; Male; Oxidative Stress; Plaque, Atherosclerotic; Risk Factors; Secondary Prevention; Signal Transduction | 2017 |
Liraglutide, a GLP-1 receptor agonist, prevents cardiovascular outcomes in patients with type 2 diabetes.
Topics: Diabetes Mellitus, Type 2; Glucagon-Like Peptide 1; Glucagon-Like Peptide-1 Receptor; Humans; Hypoglycemic Agents; Liraglutide | 2017 |
Albiglutide, a weekly GLP-1 receptor agonist, improves glycemic parameters in Japanese patients with type 2 diabetes over 1 year when added to single oral antidiabetic drugs.
To evaluate the safety and efficacy of once weekly albiglutide added to a single oral antidiabetic drug (OAD) in Japanese patients with inadequately controlled type 2 diabetes mellitus (T2DM).. In this phase 3, 1 year study (NCT01777282), patients (N = 374) received albiglutide 30 mg plus a single OAD (sulfonylurea [n = 120], biguanide [n = 67)], glinide [n = 65], thiazolidinedione [n = 61], or α-glucosidase inhibitor [n = 61]). Albiglutide could be increased to 50 mg after Week 4, based on glycemic criteria. Primary endpoints were the incidence of adverse events (AEs) and hypoglycemia; secondary endpoints were changes from baseline at Week 52 in HbA. On-therapy AEs occurred in 78.6% of patients and serious AEs in 2.1%. Common AEs were nasopharyngitis (32.6%), constipation (7.2%), and diabetic retinopathy (5.3%). No serious AEs occurred more than once or were reported in >1 patient. Hypoglycemia occurred in 6.4% of patients, mostly in the albiglutide + sulfonylurea (14.2%) and the albiglutide + glinide (6.2%) groups. Albiglutide was uptitrated in 53.2% of patients. Mean baseline HbA. When combined with a single OAD in Japanese patients with inadequately controlled T2DM, albiglutide led to favorable changes in all glycemic parameters, with minor changes in body weight depending on the background OAD. No new safety concerns were noted. Topics: Adult; Aged; Blood Glucose; Diabetes Mellitus, Type 2; Female; Glucagon-Like Peptide 1; Glucagon-Like Peptide-1 Receptor; Glycated Hemoglobin; Humans; Hyperglycemia; Hypoglycemia; Hypoglycemic Agents; Male; Middle Aged; Recombinant Proteins | 2017 |
Duodenal-jejunal bypass attenuates progressive failure of pancreatic islets in streptozotocin-induced diabetic rats.
Preservation of pancreatic beta cell function has been increasingly appealing in the treatment of type 2 diabetes. Evidence is still limited on how bariatric surgery affects pancreatic beta cell apoptosis.. University medical center.. The study aimed to investigate the effect of a major component of Roux-en-Y gastric bypass, duodenal-jejunal bypass, on protecting pancreatic beta cells from progressive loss.. Forty-five normal Sprague-Dawley rats were randomly assigned into 3 groups: duodenal-jejunal bypass (DJB) group (n = 16) and sham (S) group (n = 17), based upon the procedure received, and a control (C) group (n = 12) without any procedure performed, to eliminate potential traumatic effects from surgery. Ten days after surgery, streptozotocin (STZ, 45 mg/kg weight) was injected intraperitoneally into each animal, including the control animals, to selectively induce pancreatic beta cell apoptosis. Weight, food intake, plasma glucose level, and the results of an oral glucose tolerance test were measured before surgery, pre-STZ injection, and up to 4 weeks after STZ injection. Plasma insulin and glucagon-like peptide-1 levels were also assayed during oral glucose tolerance test. At the end, pancreatic tissues were sliced and stained for beta cell analysis.. There were no significant differences in weight among all groups at any time points measured, despite rats in the S and C groups consuming more food than those in the DJB group as measured on day 10 (P<.05) and day 20 (P<.01) after STZ injection. Animals undergoing DJB did not experience symptoms typical of uncompensated diabetes, including hyperphagia and progressive weight loss. After STZ injection, fasting plasma glucose levels in the DJB group were significantly lower than those in the C and S groups (P<.001). When challenged by glucose load, DJB rats also had a better glycemic excursion (P<.01) and incretin response compared with C and S rats (P<.05). In addition, pancreatic beta cell size and mass was better preserved in DJB rats (P< .001).. DJB is able to protect pancreatic beta cells from apoptosis, which leads to better glycemic control and delayed onset of diabetes. These results imply the necessity of including a DJB component when designing bariatric procedure to achieve a better long-term outcome. Topics: Analysis of Variance; Anastomosis, Surgical; Animals; Apoptosis; Blood Glucose; Body Weight; Diabetes Mellitus, Experimental; Diabetes Mellitus, Type 2; Duodenum; Eating; Fasting; Gastric Bypass; Glucagon-Like Peptide 1; Glucose Tolerance Test; Incretins; Injections, Intraperitoneal; Insulin; Islets of Langerhans; Jejunum; Male; Random Allocation; Rats, Sprague-Dawley; Streptozocin | 2017 |
Roux-en-Y gastric bypass versus calorie restriction: support for surgery per se as the direct contributor to altered responses of insulin and incretins to a mixed meal.
To study the immediate effects of Roux-en-Y gastric bypass (RYGB) on glucose homeostasis, insulin, and incretin responses to mixed-meal tests compared with the effects of calorie restriction (CR).. University-affiliated bariatric surgery clinic.. RYGB induces remission of type 2 diabetes (T2D) long before significant weight loss occurs. The time course and underlying mechanisms of this remission remain enigmatic. A prevailing theory is that secretory patterns of incretin hormones are altered due to rearrangement of the gastrointestinal tract. To what extent reduced calorie intake contributes to the remission of T2D is unknown.. Nine normoglycemic patients and 10 T2D patients were subjected to mixed-meal tests (MMT) 4 weeks before surgery before initiation of a very low calorie diet regimen (MMT. CR lowered insulin in T2D patients, whereas glucose, GIP, and GLP-1 were unaffected. RYGB immediately increased plasma insulin and GIP. The GLP-1 response was delayed compared with the GIP response. T2D patients exhibited lower insulin responses after RYGB compared with normoglycemic patients. GIP responses were similar in both groups at all occasions, whereas T2D patients displayed markedly elevated GLP-1 responses 6 weeks after RYGB. Glucose was unaffected by CR and RYGB in both groups. Insulin sensitivity was unaffected by CR but improved with RYGB.. RYGB exerts powerful and immediate effects on insulin and incretin responses to food, independently of changes caused by CR. Topics: Adult; Blood Glucose; Caloric Restriction; Diabetes Mellitus, Type 2; Female; Gastric Bypass; Gastric Inhibitory Polypeptide; Glucagon-Like Peptide 1; Homeostasis; Humans; Hypoglycemic Agents; Incretins; Insulin; Insulins; Meals; Obesity | 2017 |
Liraglutide for weight management: benefits and risks.
Topics: Body Weight; Diabetes Mellitus, Type 2; Glucagon-Like Peptide 1; Hypoglycemic Agents; Liraglutide; Obesity; Risk Assessment; Weight Loss | 2017 |
A novel GLP-1 analog, a dimer of GLP-1 via covalent linkage by a lysine, prolongs the action of GLP-1 in the treatment of type 2 diabetes.
GLP-1 is an incretin hormone that can effectively lower blood glucose, however, the short time of biological activity and the side effect limit its therapeutic application. Many methods have been tried to optimize GLP-1 to extend its in vivo half-time, reduce its side effect and enhance its activity. Here we have chosen the idea to dimerize GLP-1 with a C-terminal lysine to form a new GLP-1 analog, DLG3312. We have explored the structure and the biological property of DLG3312, and the results indicated that DLG3312 not only remained the ability to activate the GLP-1R, but also strongly stimulated Min6 cell to secrete insulin. The in vivo bioactivities have been tested on two kinds of animal models, the STZ induced T2DM mice and the db/db mice, respectively. DLG3312 showed potent anti-diabetic ability in glucose tolerance assay and single-dose administration of DLG3312 could lower blood glucose for at least 10 hours. Long-term treatment with DLG3312 can reduce fasted blood glucose, decrease water consumption and food intake and significantly reduce the HbA1c level by 1.80% and 2.37% on STZ induced T2DM mice and the db/db mice, respectively. We also compared DLG3312 with liraglutide to investigate its integrated control of the type 2 diabetes. The results indicated that DLG3312 almost has the same effect as liraglutide but with a much simpler preparation process. In conclusion, we, by using C-terminal lysine as a linker, have synthesized a novel GLP-1 analog, DLG3312. With simplified preparation and improved physiological characterizations, DLG3312 could be considered as a promising candidate for the type 2 diabetes therapy. Topics: Animals; Blood Glucose; Diabetes Mellitus, Type 2; Glucagon-Like Peptide 1; Glucagon-Like Peptide-1 Receptor; Humans; Hypoglycemic Agents; Insulin; Mice | 2017 |
Incretin-related drugs and cardiovascular events: A comparison of GLP-1 analogue and DPP-4 inhibitor.
Topics: Blood Glucose; Cardiovascular Diseases; Diabetes Mellitus, Type 2; Glucagon-Like Peptide 1; Humans; Hypoglycemic Agents | 2017 |
Glucose Metabolism After Gastric Banding and Gastric Bypass in Individuals With Type 2 Diabetes: Weight Loss Effect.
The superior effect of Roux-en-Y gastric bypass (RYGB) on glucose control compared with laparoscopic adjustable gastric banding (LAGB) is confounded by the greater weight loss after RYGB. We therefore examined the effect of these two surgeries on metabolic parameters matched on small and large amounts of weight loss.. Severely obese individuals with type 2 diabetes were tested for glucose metabolism, β-cell function, and insulin sensitivity after oral and intravenous glucose stimuli, before and 1 year after RYGB and LAGB, and at 10% and 20% weight loss after each surgery.. RYGB resulted in greater glucagon-like peptide 1 release and incretin effect, compared with LAGB, at any level of weight loss. RYGB decreased glucose levels (120 min and area under the curve for glucose) more than LAGB at 10% weight loss. However, the improvement in glucose metabolism, the rate of diabetes remission and use of diabetes medications, insulin sensitivity, and β-cell function were similar after the two types of surgery after 20% equivalent weight loss.. Although RYGB retained its unique effect on incretins, the superiority of the effect of RYGB over that of LAGB on glucose metabolism, which is apparent after 10% weight loss, was attenuated after larger weight loss. Topics: Adult; Bariatric Surgery; Diabetes Mellitus, Type 2; Female; Gastric Bypass; Glucagon-Like Peptide 1; Glucose; Humans; Incretins; Insulin Resistance; Longitudinal Studies; Male; Middle Aged; Obesity; Postoperative Period; Prospective Studies; Sweetening Agents; Weight Loss | 2017 |
Neoglycolipids for Prolonging the Effects of Peptides: Self-Assembling Glucagon-like Peptide 1 Analogues with Albumin Binding Properties and Potent in Vivo Efficacy.
Novel principles for optimizing the properties of peptide-based drugs are needed in order to leverage their full pharmacological potential. We present the design, synthesis, and evaluation of a library of neoglycolipidated glucagon-like peptide 1 (GLP-1) analogues, which are valuable drug candidates for treatment of type 2 diabetes and obesity. Neoglycolipidation of GLP-1 balanced the lipophilicity, directed formation of soluble oligomers, and mediated albumin binding. Moreover, neoglycolipidation did not compromise bioactivity, as in vitro potency of neoglycolipidated GLP-1 analogues was maintained or even improved compared to native GLP-1. This translated into pronounced in vivo efficacy in terms of both decreased acute food intake and improved glucose homeostasis in mice. Thus, we propose neoglycolipidation as a novel, general method for modulating the properties of therapeutic peptides. Topics: Albumins; Animals; Delayed-Action Preparations; Diabetes Mellitus, Type 2; Glucagon-Like Peptide 1; Glucose; Glucose Tolerance Test; Glycolipids; Homeostasis; Hypoglycemic Agents; Insulin; Male; Mice; Peptides | 2017 |
The cost-effectiveness of dulaglutide versus liraglutide for the treatment of type 2 diabetes mellitus in Spain in patients with BMI ≥30 kg/m
Dulaglutide 1.5 mg once weekly is a novel glucagon-like peptide 1 (GLP-1) receptor agonist, for the treatment of type two diabetes mellitus (T2DM). The objective was to estimate the cost-effectiveness of dulaglutide once weekly vs liraglutide 1.8 mg once daily for the treatment of T2DM in Spain in patients with a BMI ≥30 kg/m. The IMS CORE Diabetes Model (CDM) was used to estimate costs and outcomes from the perspective of Spanish National Health System, capturing relevant direct medical costs over a lifetime time horizon. Comparative safety and efficacy data were derived from direct comparison of dulaglutide 1.5 mg vs liraglutide 1.8 mg from the AWARD-6 trial in patients with a body mass index (BMI) ≥30 kg/m. Under base case assumptions, dulaglutide 1.5 mg was less costly and more effective vs liraglutide 1.8 mg (total lifetime costs €108,489 vs €109,653; total QALYS 10.281 vs 10.259). OWSA demonstrated that dulaglutide 1.5 mg remained dominant given plausible variations in key input parameters. Results of the PSA were consistent with base case results.. Primary limitations of the analysis are common to other cost-effectiveness analyses of chronic diseases like T2DM and include the extrapolation of short-term clinical data to the lifetime time horizon and uncertainty around optimum treatment durations.. The model found that dulaglutide 1.5 mg was more effective and less costly than liraglutide 1.8 mg for the treatment of T2DM in Spain. Findings were robust to plausible variations in inputs. Based on these results, dulaglutide may result in cost savings to the Spanish National Health System. Topics: Aged; Body Mass Index; Computer Simulation; Cost-Benefit Analysis; Diabetes Complications; Diabetes Mellitus, Type 2; Drug Administration Schedule; Fees, Pharmaceutical; Female; Glucagon-Like Peptide 1; Glucagon-Like Peptides; Glycated Hemoglobin; Health Services; Humans; Hypoglycemic Agents; Immunoglobulin Fc Fragments; Liraglutide; Male; Markov Chains; Middle Aged; Models, Econometric; Quality-Adjusted Life Years; Recombinant Fusion Proteins; Spain | 2017 |
Lactobacillus rhamnosus NCDC17 ameliorates type-2 diabetes by improving gut function, oxidative stress and inflammation in high-fat-diet fed and streptozotocintreated rats.
Restoration of dysbiosed gut microbiota through probiotic may have profound effect on type 2 diabetes. In the present study, rats were fed high fat diet (HFD) for 3 weeks and injected with low dose streptozotocin to induce type 2 diabetes. Diabetic rats were then fed Lactobacillus rhamnosus NCDC 17 and L. rhamnosus GG with HFD for six weeks. L. rhamnosus NCDC 17 improved oral glucose tolerance test, biochemical parameters (fasting blood glucose, plasma insulin, glycosylated haemoglobin, free fatty acids, triglycerides, total cholesterol, low-density lipoprotein cholesterol and high-density lipoprotein cholesterol), oxidative stress (thiobarbituric acid reactive substance and activities of catalase, superoxide dismutase and glutathione peroxidase in blood and liver), bifidobacteria and lactobacilli in cecum, expression of glucagon like peptide-1 producing genes in cecum, and adiponection in epididymal fat, while decreased propionate proportions (%) in caecum, and expression of tumour necrosis factor-α and interlukin-6 in epididymal fat of diabetic rats as compared to diabetes control group. These findings offered a base for the use of L. rhamnosus NCDC 17 for the improvement and early treatment of type 2 diabetes. Topics: Adiponectin; Animals; Blood Glucose; Cecum; Cultured Milk Products; Diabetes Mellitus, Experimental; Diabetes Mellitus, Type 2; Diet, High-Fat; Dietary Supplements; Gastrointestinal Microbiome; Glucagon-Like Peptide 1; Glucose Tolerance Test; Interleukin-6; Lacticaseibacillus rhamnosus; Male; Oxidative Stress; Probiotics; Propionates; Rats; Rats, Wistar; Streptozocin; Tumor Necrosis Factor-alpha | 2017 |
Albiglutide for the treatment of type 2 diabetes mellitus.
Topics: Adult; Aged; Aged, 80 and over; Diabetes Mellitus, Type 2; Female; Glucagon-Like Peptide 1; Humans; Hypoglycemic Agents; Incretins; Male; Middle Aged | 2017 |
Glucagon-like peptide-1 analogues - an efficient therapeutic option for the severe insulin resistance of lipodystrophic syndromes: two case reports.
Lipodystrophic syndromes are uncommon medical conditions which are normally associated with metabolic disorders, such as diabetes mellitus, dyslipidemia, and fatty liver disease. These complications are generally difficult to treat, particularly diabetes, due to severe insulin resistance. We present two case reports of successful treatment of diabetes with glucagon-like peptide-1 analogues in patients with clinical features of lipodystrophic syndromes.. Two white women aged 49 and 60 years manifested marked central body fat deposition with severe lipoatrophy of their limbs and buttocks and pronounced acanthosis nigricans. They had hypertension, dyslipidemia, fatty liver disease, and poorly controlled diabetes (glycated hemoglobin 8.3% and 10.2%, respectively) despite the use of three classes of oral antidiabetic drugs taken in combination in the first case, and high doses of insulin in the second case. Four months after the addition of glucagon-like peptide-1 analogue to their previous treatment they both showed a pronounced improvement in metabolic control (glycated hemoglobin 5.6% and 6.2%, respectively). In the first case, a weight loss of nearly 30 kg was recorded.. We intend to demonstrate that glucagon-like peptide-1 analogues could be a valuable tool for patients with lipodystrophic disorders, probably by improving body fat distribution, with favorable results in insulin-sensitivity and glycemic control. Topics: Diabetes Mellitus, Type 2; Female; Glucagon-Like Peptide 1; Humans; Hypoglycemic Agents; Insulin Resistance; Lipodystrophy; Middle Aged; Obesity; Treatment Outcome; Weight Loss | 2017 |
Discovery of Pyrrolidine-Containing GPR40 Agonists: Stereochemistry Effects a Change in Binding Mode.
A novel series of pyrrolidine-containing GPR40 agonists is described as a potential treatment for type 2 diabetes. The initial pyrrolidine hit was modified by moving the position of the carboxylic acid, a key pharmacophore for GPR40. Addition of a 4-cis-CF Topics: Animals; Blood Glucose; Cell Line; Cells, Cultured; Diabetes Mellitus, Type 2; Glucagon-Like Peptide 1; Humans; Hypoglycemic Agents; Insulin; Male; Mice, Inbred C57BL; Models, Molecular; Pyrrolidines; Rats; Receptors, G-Protein-Coupled | 2017 |
[Cardiovascular effects of liraglutide therapy in patients with type 2 diabetes : Liraglutide Effect and Action in Diabetes: Evaluation of Cardiovascular Outcome Results (LEADER)].
Topics: Cardiovascular Diseases; Diabetes Mellitus, Type 2; Glucagon-Like Peptide 1; Humans; Hypoglycemic Agents; Liraglutide | 2017 |
Hybrid peptides in the landscape of drug discovery.
Topics: Animals; Diabetes Mellitus, Type 2; Drug Discovery; Estrogens; Glucagon; Glucagon-Like Peptide 1; Humans; Ligands; Models, Animal; Obesity; Peptide Hormones; Recombinant Fusion Proteins | 2017 |
A Synthetic-Biology-Inspired Therapeutic Strategy for Targeting and Treating Hepatogenous Diabetes.
Hepatogenous diabetes is a complex disease that is typified by the simultaneous presence of type 2 diabetes and many forms of liver disease. The chief pathogenic determinant in this pathophysiological network is insulin resistance (IR), an asymptomatic disease state in which impaired insulin signaling in target tissues initiates a variety of organ dysfunctions. However, pharmacotherapies targeting IR remain limited and are generally inapplicable for liver disease patients. Oleanolic acid (OA) is a plant-derived triterpenoid that is frequently used in Chinese medicine as a safe but slow-acting treatment in many liver disorders. Here, we utilized the congruent pharmacological activities of OA and glucagon-like-peptide 1 (GLP-1) in relieving IR and improving liver and pancreas functions and used a synthetic-biology-inspired design principle to engineer a therapeutic gene circuit that enables a concerted action of both drugs. In particular, OA-triggered short human GLP-1 (shGLP-1) expression in hepatogenous diabetic mice rapidly and simultaneously attenuated many disease-specific metabolic failures, whereas OA or shGLP-1 monotherapy failed to achieve corresponding therapeutic effects. Collectively, this work shows that rationally engineered synthetic gene circuits are capable of treating multifactorial diseases in a synergistic manner by multiplexing the targeting efficacies of single therapeutics. Topics: Animals; Cell Engineering; Cell Line; Diabetes Mellitus, Type 2; Disease Models, Animal; Drug Design; Gene Expression Regulation; Gene Regulatory Networks; Genetic Engineering; Glucagon-Like Peptide 1; Humans; Insulin Resistance; Liver Diseases; Male; Mice; Mice, Transgenic; Oleanolic Acid; Synthetic Biology | 2017 |
Lifestyle change reduces cardiometabolic risk factors and glucagon-like peptide-1 levels in obese first-degree relatives of people with diabetes.
Preventing type 2 diabetes in a real-world setting remains challenging. The present study aimed to assess the effectiveness of a lifestyle-based programme for individuals at high risk of developing type 2 diabetes as assessed by achieved weight loss, cardiovascular risk factors and glucagon-like peptide-1 (GLP-1).. Sixty-six obese individuals with history of diabetes in first-degree relatives participated in an 8-month lifestyle programme consisting of 12 × 1.25 h group education sessions led by dietitian and a weekly exercise programme. Before and after comparisons were made of fasting blood glucose, insulin, HbA1c, lipids, GLP-1 and quality of life (QoL).. Fifty-four participants of whom the majority were women [47 females; mean (SD) body mass index 35.3 (2.8) kg m. An evidence-based lifestyle programme achieved sustained weight loss in obese first-degree relatives of individuals with type 2 diabetes associated with improvements in cardiometabolic risk factors and QoL without the 'voltage drop' of less benefit commonly seen when moving from the clinical trial experience into the real world. Topics: Adolescent; Adult; Aged; Blood Glucose; Body Mass Index; Body Weight; Cardiovascular Diseases; Diabetes Mellitus, Type 2; Female; Glucagon-Like Peptide 1; Glycated Hemoglobin; Humans; Insulin; Life Style; Middle Aged; Non-Randomized Controlled Trials as Topic; Obesity; Quality of Life; Risk Factors; Weight Loss; Young Adult | 2017 |
Real-World Glycemic Control from GLP-1RA Therapy with and Without Concurrent Insulin in Patients with Type 2 Diabetes.
Glucagon-like peptide 1 receptor agonists (GLP-1RAs) are recommended as add-on therapy in patients with uncontrolled type 2 diabetes (T2D), with no specific guidance as to timing versus insulin. Furthermore, real-world data assessing GLP-1RA outcomes with or without concurrent insulin therapy are lacking.. To identify glycemic response with GLP-1RAs by insulin use in patients with T2D at 1-year follow-up to inform decisions regarding GLP-1RA use with or without insulin.. This uncontrolled retrospective cohort study included adults with T2D in the Quintiles Electronic Medical Records Database who were newly prescribed GLP-1RA therapy with exenatide once weekly or liraglutide once daily between February 1, 2012, and March 31, 2013 (index period). Primary outcomes were change in hemoglobin A1c (A1c) at 1 year and attainment of A1c < 7%, < 8%, and < 9%. Results were stratified by baseline insulin use, which was defined as no insulin use at baseline, insulin initiated with a GLP-1RA on index date, and insulin prescribed before starting GLP-1RA therapy. Secondary outcomes included 1-year weight, low-density lipoprotein cholesterol (LDL-C), and blood pressure outcomes for the study population. Adjusted mean (marginal) change in A1c at 1 year was estimated using multivariate linear regression, and multivariate logistic regression was used to estimate the likelihood of patients attaining A1c < 7% at follow-up, controlling for potential confounders.. This study included 5,141 patients with a mean (SD) age of 57.0 (10.9) years, 53.5% of whom were females, and with a mean baseline A1c of 8.4% (1.6). Overall, 35.4% had no baseline insulin use, 42.9% were prescribed insulin before starting GLP-1RA therapy, and 21.7% were started on insulin with a GLP-1RA. The adjusted mean A1c reduction at 1 year was 0.75% (95% CI = -0.86 to -0.63) for patients initiating insulin on index date, 0.61% (95% CI = -0.70 to -0.51) for patients with no baseline insulin use, and 0.23% (95% CI = -0.33 to -0.13) for patients prescribed insulin before GLP-1RA therapy. Patients with no baseline insulin or who coinitiated insulin and a GLP-1RA were more likely to attain A1c < 7% at follow-up versus patients prescribed insulin before initiating GLP-1RA therapy (OR = 1.50, 95% CI = 1.08 to 2.09 and OR = 1.85, 95% CI = 1.30 to 2.62, respectively). At 1-year follow-up, significant improvements in weight, LDL-C, and blood pressures were also observed.. GLP-1RA therapy was associated with significant improvements in glycemic control when used with or without insulin, as well as reductions in weight and LDL-C overall. However, greater A1c reductions and a higher likelihood of attaining A1c goal levels were observed when a GLP-1RA was initiated alone or with insulin than when a GLP-1RA was added to a regimen that included insulin. GLP-1RA therapy is an effective treatment option when used with or without insulin and may be considered in patients with uncontrolled glycemia.. The study was funded by a collaborative research grant from AstraZeneca. Employees of AstraZeneca participated in most aspects of the study and in manuscript preparation. Nguyen and Hurd are employed by, and hold stock in, AstraZeneca. McAdam-Marx reports participation in the AMCP Diabetes Partnership and has stock ownership in GlaxoSmithKline. Study concept and design were contributed by Nguyen, McAdam-Marx, and Singhal, along with Unni and Schauerhamer. Singhal, Unni, Nguyen, and McAdam-Marx collected the data, with assistance from Schauerhamer and Hurd, and data interpretation was performed by Unni, Hurd, McAdam-Marx, Singhal, Nguyen, and Schauerhamer. The manuscript was written by Singhal, Schauerhamer, Unni, and McAdam-Marx, along with Nguyen and Hurd, and revised by McAdam-Marx, Singhal, Unni, and Nguyen, along with Schauerhamer and Hurd. Topics: Blood Glucose; Blood Pressure; Diabetes Mellitus, Type 2; Exenatide; Female; Glucagon-Like Peptide 1; Glucagon-Like Peptide-1 Receptor; Glycated Hemoglobin; Humans; Hypoglycemic Agents; Insulin; Lipoproteins, LDL; Liraglutide; Male; Middle Aged; Peptides; Retrospective Studies; Venoms | 2017 |
Glucagon-Like Peptide 1 Protects Pancreatic β-Cells From Death by Increasing Autophagic Flux and Restoring Lysosomal Function.
Studies in animal models of type 2 diabetes have shown that glucagon-like peptide 1 (GLP-1) receptor agonists prevent β-cell loss. Whether GLP-1 mediates β-cell survival via the key lysosomal-mediated process of autophagy is unknown. In this study, we report that treatment of INS-1E β-cells and primary islets with glucolipotoxicity (0.5 mmol/L palmitate and 25 mmol/L glucose) increases LC3 II, a marker of autophagy. Further analysis indicates a blockage in autophagic flux associated with lysosomal dysfunction. Accumulation of defective lysosomes leads to lysosomal membrane permeabilization and release of cathepsin D, which contributes to cell death. Our data further demonstrated defects in autophagic flux and lysosomal staining in human samples of type 2 diabetes. Cotreatment with the GLP-1 receptor agonist exendin-4 reversed the lysosomal dysfunction, relieving the impairment in autophagic flux and further stimulated autophagy. Small interfering RNA knockdown showed the restoration of autophagic flux is also essential for the protective effects of exendin-4. Collectively, our data highlight lysosomal dysfunction as a critical mediator of β-cell loss and shows that exendin-4 improves cell survival via restoration of lysosomal function and autophagic flux. Modulation of autophagy/lysosomal homeostasis may thus define a novel therapeutic strategy for type 2 diabetes, with the GLP-1 signaling pathway as a potential focus. Topics: Adult; Animals; Apoptosis; Autophagy; Blotting, Western; Case-Control Studies; Cathepsin D; Cell Line; Cell Survival; Diabetes Mellitus, Type 2; Exenatide; Glucagon-Like Peptide 1; Glucose; Humans; Immunohistochemistry; Incretins; Insulin-Secreting Cells; Islets of Langerhans; Lysosomes; Mice; Microtubule-Associated Proteins; Middle Aged; Palmitates; Peptides; Rats; Real-Time Polymerase Chain Reaction; Reverse Transcriptase Polymerase Chain Reaction; RNA, Small Interfering; Venoms | 2017 |
Effects of Duodenal-Jejunal Exclusion and New Bilio-Pancreatic Diversion on Blood Glucose in Rats with Type 2 Diabetes Mellitus.
The current study aimed to investigate the effects of duodenal-jejunal bypass (DJB), new bilio-pancreatic diversion (NBPD), and duodenal-jejunal exclusion (DJE) on blood glucose in rats with type 2 diabetes mellitus (T2DM).. Male Sprague Dawley rats were fed with high glucose, high fat food, and intraperitoneally injected with streptozotocin to establish a T2DM animal model. T2DM rats were randomly assigned into 4 groups: a sham group (n = 8), DJB group (n = 9), NBPD group (n = 10), and DJE group (n = 10). Body weight, 2-h postprandial glucose, oral glucose tolerance, fasting serum bile acid, 2-h postprandial serum bile acid, fasting insulin, 2-h postprandial insulin (INS), fasting glucagon-like peptide-1 (GLP-1), and 2-h postprandial GLP-1 were measured before and after surgery.. Six weeks after surgery, the 2-h postprandial glucose in the DJB (16.1 ± 6.7 mmol/L) and NBPD (19.5 ± 5.7 mmol/L) groups decreased significantly compared to the sham group (25.8 ± 4.9 mmol/L) (P < 0.05). There was no significant difference between the DJE (25.0 ± 5.0 mmol/L) and sham groups (P > 0.05). Four weeks after surgery, fasting serum bile acid in the DJB group (60.6 ± 11.4 μmol/L) and NBPD group (54.4 ± 7.64 μmol/L) was significantly higher than that in the sham group (34.3 ± 6.98 μmol/L; P < 0.05). However, fasting GLP-1, 2-h postprandial GLP-1, and insulin remained unchanged at different time points after surgery (P > 0.05). Body weight remained stable after surgery in all 4 groups (P > 0.05).. NBPD plays a major role in the therapy of T2DM with DJB. NBPD may significantly increase fasting serum bile acid in T2DM rats, an action that may be one of the mechanisms underlying the therapeutic effects of DJB on T2DM. Topics: Animals; Biliopancreatic Diversion; Blood Glucose; Diabetes Mellitus, Experimental; Diabetes Mellitus, Type 2; Duodenum; Gastric Bypass; Glucagon-Like Peptide 1; Glucose Tolerance Test; Insulin; Insulin Resistance; Jejunum; Male; Rats; Rats, Sprague-Dawley; Streptozocin | 2017 |
Treating prediabetes in the obese: are GLP-1 analogues the answer?
Topics: Blood Glucose; Diabetes Mellitus, Type 2; Glucagon-Like Peptide 1; Humans; Hypoglycemic Agents; Obesity; Prediabetic State | 2017 |
Gastric bypass in the pig increases GIP levels and decreases active GLP-1 levels.
Gastric bypass surgery results in remission of type 2 diabetes in the majority of patients. The incretin hormones glucagon-like peptide 1 (GLP-1) and glucose-dependent insulinotropic polypeptide (GIP) have been implicated in the observed remission. Most knowledge so far has been generated in obese subjects. To isolate the surgical effects of gastric bypass on metabolism and hormone responses from the confounding influence of obesity, T2D, or food intake, we performed gastric bypass in lean pigs, using sham-operated and pair-fed pigs as controls. Thus, pigs were subjected to Roux-en-Y gastric bypass (RYGB) or sham surgery and oral glucose tolerance tests (OGTT). RYGB pigs and sham pigs exhibited similar basal and 120-min glucose levels in response to the OGTT. However, RYGB pigs had approximately 1.6-fold higher 30-min glucose (p<0.01). Early insulin release (EIR) was enhanced approximately 3.5-fold in the RYGB pigs (p<0.01). Furthermore, GIP release, both acute and sustained release (p<0.001 and p<0.01, respectively), was increased approximately 2.5-fold and 1.4-fold, respectively, in RYGB pigs. Although total GLP-1 release increased approximately 2.1-fold after RYGB (p<0.001), active GLP-1 was 33% lower (p<0.01). Interestingly basal DPP4-activity was approximately 3.2-fold higher in RYGB pigs (p<0.001). In conclusion, RYGB in lean pigs increases the response of GIP, total GLP-1, and insulin, but reduces levels of active GLP-1 in response to an oral glucose load. These data challenge the role of active GLP-1 as a contributor to remission from diabetes after RYGB. Topics: Animals; Diabetes Mellitus, Type 2; Female; Gastric Bypass; Gastric Inhibitory Polypeptide; Glucagon; Glucagon-Like Peptide 1; Glucose Tolerance Test; Humans; Insulin; Insulin Resistance; Obesity; Sus scrofa | 2017 |
Is HOMA-IR a potential screening test for non-alcoholic fatty liver disease in adults with type 2 diabetes?
Non-alcoholic fatty liver disease (NAFLD) is the commonest hepatic disease in many parts of the World, with particularly high prevalence in patients with type 2 diabetes (T2DM). However, a good screening test for NAFLD in T2DM has not been established. Insulin resistance (IR) has been associated with NAFLD, and homeostatic model assessment of insulin resistance (HOMA-IR), a good proxy for IR, may represent an affordable predictive test which could be easily applied in routine clinical practice. We aimed to evaluate the diagnostic accuracy of HOMA-IR for NAFLD in T2DM and sought to estimate an optimal cut-off value for discriminating NAFLD from non-NAFLD cases.. We conducted a retrospective analysis of 56 well-controlled patients with T2DM (HbAc1<7%, on oral anti-diabetic and/or glucagon-like peptide-1 agonist treatment), who had at least one glucose and insulin level determined, and at least one hepatic imaging test (ultrasonography or computed tomography scanning).. The prevalence of NAFLD was 73.2% (95% CI: 59.7-84.2) in our population. An association between HOMA-IR and NAFLD was found (OR 1.5; 95% CI: 1.03-2.1; p=0.033), independently of transaminases, fat percentage, BMI and triglyceride levels. The AUROC curve of HOMA-IR for identifying NAFLD was 80.7% (95% CI: 68.9-92.5). A value of HOMA-IR of 4.5 was estimated to be an optimal threshold for discriminating NAFLD from non-NAFLD cases.. HOMA-IR is independently associated with the presence of NAFLD in adults with T2DM, and might potentially be applied in clinical practice as a screen for this condition. Topics: Aged; Diabetes Mellitus, Type 2; Female; Glucagon-Like Peptide 1; Humans; Insulin; Insulin Resistance; Liver; Logistic Models; Male; Mass Screening; Middle Aged; Non-alcoholic Fatty Liver Disease; Retrospective Studies; ROC Curve; Spain; Tomography, X-Ray Computed; Ultrasonography | 2017 |
Purification, Conformational Analysis, and Properties of a Family of Tigerinin Peptides from Skin Secretions of the Crowned Bullfrog Hoplobatrachus occipitalis.
Four host-defense peptides belonging to the tigerinin family (tigerinin-1O: RICTPIPFPMCY; tigerinin-2O: RTCIPIPLVMC; tigerinin-3O: RICTAIPLPMCL; and tigerinin-4O: RTCIPIPPVCF) were isolated from skin secretions of the African crowned bullfrog Hoplobatrachus occipitalis. In aqueous solution at pH 4.8, the cyclic domain of tigerinin-2O adopts a rigid amphipathic conformation that incorporates a flexible N-terminal tail. The tigerinins lacked antimicrobial (MIC > 100 μM) and hemolytic (LC50 > 500 μM) activities but, at a concentration of 20 μg/mL, significantly (P < 0.05) inhibited production of interferon-γ (IFN-γ) by peritoneal cells from C57BL/6 mice without affecting production of IL-10 and IL-17. Tigerinin-2O and -4O inhibited IFN-γ production at concentrations as low as 1 μg/mL. The tigerinins significantly (P ≤ 0.05) stimulated the rate of insulin release from BRIN-BD11 clonal β-cells without compromising the integrity of the plasma membrane. Tigerinin-1O was the most potent (threshold concentration 1 nM) and the most effective (395% increase over basal rate at a concentration of 1 μM). Tigerinin-4O was the most potent and effective peptide in stimulating the rate of glucagon-like peptide-1 release from GLUTag enteroendocrine cells (threshold concentration 10 nM; 289% increase over basal rate at 1 μM). Tigerinin peptides have potential for development into agents for the treatment of patients with type 2 diabetes. Topics: Amphibian Proteins; Animals; Antimicrobial Cationic Peptides; Diabetes Mellitus, Type 2; Humans; Hydrogen-Ion Concentration; Insulin; Interleukin-10; Interleukin-17; Mice; Mice, Inbred C57BL; Microbial Sensitivity Tests; Peptides; Rana catesbeiana; Skin | 2016 |
Incretin secretion in obese Korean children and adolescents with newly diagnosed type 2 diabetes.
The role of incretins in type 2 diabetes is controversial. This study investigated the association between incretin levels in obese Korean children and adolescents newly diagnosed with type 2 diabetes.. We performed a 2-hr oral glucose tolerance test (OGTT) in obese children and adolescents with type 2 diabetes and with normal glucose tolerance.. Twelve obese children and adolescents with newly diagnosed type 2 diabetes (DM group) and 12 obese age-matched subjects without type 2 diabetes (NDM group) were included.. An OGTT was conducted and insulin, C-peptide, glucagon, glucagon-like peptide-1 (GLP-1) and glucose-dependent insulinotropic polypeptide (GIP) were measured during the OGTT.. The mean age of the patients was 13·8 ± 2·0 years, and the mean body mass index (BMI) Z-score was 2·1 ± 0·5. The groups were comparable in age, sex, BMI Z-score and waist:hip ratio. The DM group had significantly lower homeostasis model assessment of β and insulinogenic index values (P < 0·001). The homeostasis model assessment of insulin resistance index was not different between the two groups. Insulin and C-peptide secretions were significantly lower in the DM group than in the NDM group (P < 0·001). Total GLP-1 secretion was significantly higher in the DM group while intact GLP-1 and GIP secretion values were not significantly different between the two groups.. Impaired insulin secretion might be important in the pathogenesis of type 2 diabetes in obese Korean children and adolescents, however, which may not be attributed to incretin secretion. Topics: Adolescent; Analysis of Variance; Asian People; Blood Glucose; Body Mass Index; C-Peptide; Case-Control Studies; Child; Diabetes Mellitus, Type 2; Female; Gastric Inhibitory Polypeptide; Glucagon; Glucagon-Like Peptide 1; Glucose Tolerance Test; Humans; Incretins; Insulin; Insulin Resistance; Male; Obesity; Republic of Korea | 2016 |
Risk of overall mortality and cardiovascular events in patients with type 2 diabetes on dual drug therapy including metformin: A large database study from the Cleveland Clinic.
The aim of the present study was to assess the risk of overall mortality, coronary artery disease (CAD), and congestive heart failure (CHF) in patients with type 2 diabetes mellitus (T2DM) treated with metformin (MF) and an additional antidiabetic agent.. A retrospective cohort study was conducted using an academic health center enterprise-wide electronic health record (EHR) system to identify 13,185 adult patients (>18 years) with T2DM from January 2008 to June 2013 and received a prescription for MF in combination with a sulfonylurea (SU; n = 9419), thiazolidinedione (TZD; n = 1846), dipeptidyl peptidase-4 inhibitor (DPP-4i; n = 1487), or a glucagon-like peptide-1 receptor agonist (GLP-1a; n = 433). Multivariate Cox models with propensity analysis were used to compare cohorts, with MF+SU serving as the comparator group.. The mean (±SD) age was 60.6 ± 12.6 years, with 54.6% male and 75.8% Caucasians. The median follow-up was 4 years. There were 1077 deaths, 1733 CAD events, and 528 CHF events in 55,100 person-years of follow-up. A higher risk of CHF was observed with MF+DPP-4i use (hazard ratio [HR] 1.104; 95% confidence interval [CI] 1.04-1.17; P = 0.001). A trend towards improved overall survival for users of MF+TZD (HR 0.86; 95% CI 0.74-1.0; P = 0.05) and MF+GLP-1a (HR 0.569; 95% CI 0.30-1.07; P = 0.08) was observed. No significant differences in the risk of CAD were identified.. Consistent with recent studies, our results raise concern for an increased risk of CHF with use of DPP-4i. Topics: Aged; Coronary Artery Disease; Diabetes Mellitus, Type 2; Dipeptidyl-Peptidase IV Inhibitors; Drug Therapy, Combination; Female; Glucagon-Like Peptide 1; Heart Failure; Humans; Hypoglycemic Agents; Male; Metformin; Middle Aged; Multivariate Analysis; Outcome Assessment, Health Care; Peptide Fragments; Proportional Hazards Models; Retrospective Studies; Risk Factors; Sulfonylurea Compounds; Survival Rate; Thiazolidinediones | 2016 |
Exclusion of the Distal Ileum Cannot Reverse the Anti-Diabetic Effects of Duodenal-Jejunal Bypass Surgery.
Duodenal-jejunal bypass (DJB) has been proven effective in glycemic control in various type 2 diabetes (T2DM) rat models. "Hindgut hypothesis" and "foregut hypothesis" are two prevailing theories to elucidate the weight-independent anti-diabetic mechanisms of DJB, however, which mechanism plays the dominant role that has not been illuminated.. This paper aims to verify that exclusion of the foregut leads to loss of weight and remission of type 2 diabetes without expedited delivery of nutrients to the distal bowel.. Thirty-five diabetic rats induced by high-fat diet (HFD) and low dose of streptozotocin (STZ) were randomly assigned to the control, sham-DJB (S-DJB), DJB, ileal bypass (ILB), and DJB combined with ILB (DJB-ILB) groups. Effects of surgeries on body weight, food intake, blood glucose, glucose-stimulated insulin, and gastrointestinal hormones secretion were evaluated at indicated time points.. Compared to the control and S-DJB groups, the DJB group had significant and sustained glycemic control independent of weight loss. Excluding part of the distal ileum did not reverse the diabetic control that followed DJB surgery. The glucagon-like peptide 1 (GLP-1) and PYY levels were significantly increased after DJB. Although GLP-1 and PYY are mainly secreted by L cells in the distal ileum, excluding part of the ileum did not decrease the levels of GLP-1 and PYY after DJB.. The beneficial effects of DJB in glycemic control could not be reversed by excluding the distal ileum. Topics: Anastomosis, Surgical; Animals; Blood Glucose; Diabetes Mellitus, Experimental; Diabetes Mellitus, Type 2; Disease Models, Animal; Duodenum; Glucagon-Like Peptide 1; Ileum; Jejunum; Male; Obesity, Morbid; Peptide YY; Rats; Rats, Wistar | 2016 |
Effect of Sleeve Gastrectomy Plus Side-to-Side Jejunoileal Anastomosis for Type 2 Diabetes Control in an Obese Rat Model.
Sleeve gastrectomy plus side-to-side jejunoileal anastomosis (JI-SG), a relatively new approach to bariatric surgeries, has shown promising results for treating obesity and metabolic comorbidities. This study investigated the feasibility and safety of JI-SG in weight loss and diabetes remission compared with sleeve gastrectomy (SG) and Roux-en-Y gastric bypass (RYGB).. Forty 10-week-old male Zucker diabetic fatty rats were randomly assigned to four groups: control, SG, JI-SG, and RYGB. Their body weights, food intake, and levels of gut hormones (ghrelin, insulin, and glucagon-like peptide-1 (GLP-1)) and lipids were measured.. Rats in the SG, JI-SG, and RYGB groups demonstrated lower food intake and more weight loss 2 weeks postoperatively compared with control rats. Furthermore, rats in the JI-SG group achieved more weight loss (mean 242.7 ± 11.2 g) compared with those in the SG and RYGB groups (SG, 401.4 ± 15.1 g and RYGB, 298 ± 12 g, both P < 0.01). All surgery groups demonstrated a decreased fasting insulin, serum glucose, lipid levels, and increased GLP-1 postoperatively. The JI-SG group had lower fasting ghrelin levels than the RYGB group (168 ± 19.8 ng/L vs. 182 ± 16.7 ng/L, P < 0.01) and higher fasting GLP-1 levels than the SG group (1.99 ± 0.11 pmol/L vs. 1.71 ± 0.12 pmol/L, P < 0.01) at 12 weeks postoperatively. Over the experimental period, the ghrelin levels slowly increased in all surgical groups but remained lower than the preoperative and control levels.. JI-SG induced higher ghrelin and GLP-1 levels and improved glycemic control in Zucker diabetic fatty rats. Compared with SG and RYGB, JI-SG appeared to be a simple, relatively safe, and more effective procedure for treating type 2 diabetes and obesity in this animal model. Topics: Anastomosis, Surgical; Animals; Blood Glucose; Diabetes Mellitus, Type 2; Disease Models, Animal; Eating; Fasting; Gastrectomy; Glucagon-Like Peptide 1; Ileum; Insulin; Jejunum; Lipids; Male; Obesity; Random Allocation; Rats; Rats, Zucker | 2016 |
Efficacy of acarbose and metformin in newly diagnosed type 2 diabetes patients stratified by HbA1c levels.
The aim of the present study was to investigate whether the therapeutic efficacy of acarbose and metformin is correlated with baseline HbA1c levels in Chinese patients with newly diagnosed type 2 diabetes mellitus (T2DM).. Data for 711 subjects were retrieved from the MARCH (Metformin and AcaRbose in Chinese as initial Hypoglycemic treatment) trial database and reviewed retrospectively. Patients were grouped according to baseline HbA1c levels (<7%, 7%-8%, and >8%) and the results for these three groups were compared between acarbose and metformin treatments.. Acarbose and metformin treatment significantly improved T2DM-associated parameters (weight, fasting plasma glucose [FPG], postprandial glucose [PPG], glucagon-like peptide-1 [GLP-1], HOMA-IR, and total cholesterol) across all HbA1c levels. Acarbose decreased PPG and HOMA-β significantly more than metformin, but only in subjects with lower baseline HbA1c (PPG in the <7% and 7%-8%, HOMA-β in the <7% groups; all P < 0.05). Acarbose decreased triglyceride (TG) levels, and the areas under the curve (AUC) for insulin and glucagon more than metformin at all HbA1c levels (P < 0.05). After 24 weeks treatment, metformin decreased FPG levels significantly more than acarbose for all baseline HbA1c groups (all P < 0.001). With the exception of FPG, PPG, and TG levels, differences between the two treatment groups observed at 24 weeks were not detected at 48 weeks.. Acarbose decreased PPG and TG and spared the AUC for insulin more effectively in patients with low-to-moderate baseline HbA1c levels, whereas metformin induced greater reductions in FPG. These results may help guide selection of initial therapy based on baseline HbA1c. Topics: Acarbose; Adult; Analysis of Variance; Asian People; Blood Glucose; China; Cholesterol; Diabetes Mellitus, Type 2; Fasting; Female; Glucagon-Like Peptide 1; Glycated Hemoglobin; Glycoside Hydrolase Inhibitors; Humans; Hypoglycemic Agents; Male; Metformin; Middle Aged; Postprandial Period; Retrospective Studies; Treatment Outcome; Triglycerides | 2016 |
Mixed meal ingestion diminishes glucose excursion in comparison with glucose ingestion via several adaptive mechanisms in people with and without type 2 diabetes.
To study the integrative impact of macronutrients on postprandial glycaemia, β-cell function, glucagon and incretin hormones in humans.. Macronutrients were ingested alone (glucose 330 kcal, protein 110 kcal or fat 110 kcal) or together (550 kcal) by healthy subjects (n = 18) and by subjects with drug-naïve type 2 diabetes (T2D; n = 18). β-cell function and insulin clearance were estimated by modelling glucose, insulin and C-peptide data. Secretion of glucose-dependent insulinotropic polypeptide (GIP) and glucagon-like peptide-1 (GLP-1) were measured, and paracetamol was administered to estimate gastric emptying.. In both groups, the mixed-meal challenge diminished glucose excursion compared with glucose challenge alone, and insulin levels, but not C-peptide levels, rose more than after the mixed meal than after glucose alone. β-cell function was augmented, insulin clearance was reduced and glucagon levels were higher after the mixed meal compared with glucose alone. GLP-1 and GIP levels increased after all challenges and GIP secretion was markedly higher after the mixed meal than after glucose alone. The appearance of paracetamol was delayed after the mixed-meal challenge compared with glucose alone.. Adding protein and fat macronutrients to glucose in a mixed meal diminished glucose excursion. This occurred in association with increased β-cell function, reduced insulin clearance, delayed gastric emptying and augmented glucagon and GIP secretion. This suggests that the macronutrient composition regulates glycaemia through both islet and extra-islet mechanisms in both healthy subjects and in subjects with T2D. Topics: Acetaminophen; Adult; Aged; Analgesics, Non-Narcotic; Blood Glucose; C-Peptide; Case-Control Studies; Diabetes Mellitus, Type 2; Dietary Fats; Dietary Proteins; Female; Gastric Emptying; Gastric Inhibitory Polypeptide; Glucagon; Glucagon-Like Peptide 1; Glucose; Healthy Volunteers; Humans; Incretins; Insulin; Insulin-Secreting Cells; Male; Meals; Middle Aged; Postprandial Period | 2016 |
Topical Administration of GLP-1 Receptor Agonists Prevents Retinal Neurodegeneration in Experimental Diabetes.
Retinal neurodegeneration is an early event in the pathogenesis of diabetic retinopathy (DR). Since glucagon-like peptide 1 (GLP-1) exerts neuroprotective effects in the central nervous system and the retina is ontogenically a brain-derived tissue, the aims of the current study were as follows: 1) to examine the expression and content of GLP-1 receptor (GLP-1R) in human and db/db mice retinas; 2) to determine the retinal neuroprotective effects of systemic and topical administration (eye drops) of GLP-1R agonists in db/db mice; and 3) to examine the underlying neuroprotective mechanisms. We have found abundant expression of GLP-1R in the human retina and retinas from db/db mice. Moreover, we have demonstrated that systemic administration of a GLP-1R agonist (liraglutide) prevents retinal neurodegeneration (glial activation, neural apoptosis, and electroretinographical abnormalities). This effect can be attributed to a significant reduction of extracellular glutamate and an increase of prosurvival signaling pathways. We have found a similar neuroprotective effect using topical administration of native GLP-1 and several GLP-1R agonists (liraglutide, lixisenatide, and exenatide). Notably, this neuroprotective action was observed without any reduction in blood glucose levels. These results suggest that GLP-1R activation itself prevents retinal neurodegeneration. Our results should open up a new approach in the treatment of the early stages of DR. Topics: Administration, Ophthalmic; Aged; Animals; Apoptosis; Blotting, Western; Diabetes Mellitus, Experimental; Diabetes Mellitus, Type 2; Diabetic Retinopathy; Electroretinography; Exenatide; Female; Glial Fibrillary Acidic Protein; Glucagon-Like Peptide 1; Glucagon-Like Peptide-1 Receptor; Humans; Immunohistochemistry; Liraglutide; Male; Mice; Middle Aged; Neuroprotective Agents; Peptides; Real-Time Polymerase Chain Reaction; Retina; Retinal Neurons; Venoms | 2016 |
In vitro and in vivo insulinotropic properties of the multifunctional frog skin peptide hymenochirin-1B: a structure-activity study.
Hymenochirin-1b (Hym-1B; IKLSPETKDNLKKVLKGAIKGAIAVAKMV.NH2) is a cationic, α-helical amphibian host-defense peptide with antimicrobial, anticancer, and immunomodulatory properties. This study investigates the abilities of the peptide and nine analogues containing substitutions of Pro(5), Glu(6), and Asp(9) by either L-lysine or D-lysine to stimulate insulin release in vitro using BRIN-BD11 clonal β cells or isolated mouse islets and in vivo using mice fed a high-fat diet to produce obesity and insulin resistance. Hym-1B produced a significant and concentration-dependent increase in the rate of insulin release from BRIN-BD11 cells without cytotoxicity at concentrations up to 1 µM with a threshold concentration of 1 nM. The threshold concentrations for the analogues were: [P5K], [E6K], [D9K], [P5K, E6K] and [E6K, D9k] 0.003 nM, [E6K, D9K] and [D9k] 0.01 nM, [P5K, D9K] 0.1 nM and [E6k] 0.3 nM. All peptides displayed cytotoxicity at concentrations ≥1 µM except the [P5K] and [D9k] analogues which were non-toxic at 3 µM. The potency and maximum rate of insulin release from mouse islets produced by the [P5K] peptide were significantly greater than produced by Hym-1B. Neither Hym-1B nor the [P5K] analogue at 1 µM concentration had an effect on membrane depolarization or intracellular Ca(2+). The [P5K] analogue (1 µM) produced a significant increase in cAMP concentration in BRIN-BD11 cells and stimulated GLP-1 secretion from GLUTag cells. Down-regulation of the protein kinase A pathway by overnight incubation with forskolin completely abolished the insulin-releasing effects of [P5K]hym-1B. Intraperitoneal administration of the [P5K] and [D9k] analogues (75 nmol/kg body weight) to high-fat-fed mice with insulin resistance significantly enhanced glucose tolerance with a concomitant increase in insulin secretion. We conclude that [P5K]hym-1B and [D9k]hym-1B show potential for development into anti-diabetic agents. Topics: Amphibian Proteins; Animals; Antimicrobial Cationic Peptides; Anura; Calcium; Cell Line; Cyclic AMP; Cyclic AMP-Dependent Protein Kinases; Diabetes Mellitus, Type 2; Diet, High-Fat; Glucagon-Like Peptide 1; Glucose; Hypoglycemic Agents; Insulin; Insulin Resistance; Insulin Secretion; Islets of Langerhans; L-Lactate Dehydrogenase; Membrane Potentials; Mice; Mice, Inbred C57BL; Organ Culture Techniques; Protein Kinase C; Rats; Structure-Activity Relationship | 2016 |
Medical treatments of elderly, French patients with type 2 diabetes: results at inclusion in the GERODIAB Cohort.
Prevalence of diabetes in the elderly increases, and half of the French diabetics are over the age of 75 years. The GERODIAB study is the first French multicentre, prospective, observational study designed to analyse over 5 years the influence of glycaemic control on morbidity-mortality in type 2 diabetics patients 70 years old and over. This study analysed the diabetic and geriatric factors associated with the treatment modalities, particularly insulin, at inclusion in the cohort. The cohort of 987 type 2 diabetics was divided into three groups according to the method of treatment. Slightly fewer than one-third of these patients (26.4%) were treated with insulin alone, 31% received insulin and oral antidiabetic drugs, and 42.7% oral antidiabetic drugs alone. The patients that received insulin alone were significantly older, had poorer glycaemic control (HbA1c = 7.9 ± 1.4, 7.8 ± 1.0 and 7.1 ± 1.2%, respectively; P < 0.001) and had greater alterations of glomerular filtration rate (GFR). HbA1c was below 6.5% in 15% of patients and 37.3% of patients had a GFR below 60 mL/min. The patients treated with insulin alone had significantly more hypoglycaemic episodes (respectively 53.3, 36.3 and 19.5%, P < 0.001), retinopathy, cardiovascular involvement and more specific geriatric complications, such as cognitive disorders (respectively 34.1, 31.4 and 23.6%, P = 0.006). In this specific population of elderly type 2 diabetic patients, diabetic and geriatric conditions significantly differed between the types of drug treatments. Considering low values of HbA1c and GFR, some patients seemed overtreated and other patients received inappropriate drugs. Topics: Administration, Oral; Age Factors; Aged; Aged, 80 and over; Blood Glucose; Cohort Studies; Diabetes Mellitus, Type 2; Drug Therapy, Combination; Female; France; Glucagon-Like Peptide 1; Glycated Hemoglobin; Health Services for the Aged; Humans; Hypoglycemic Agents; Insulin; Male; Prevalence; Prospective Studies | 2016 |
Hepatic role in an early glucose-lowering effect by a novel dipeptidyl peptidase 4 inhibitor, evogliptin, in a rodent model of type 2 diabetes.
Although multiple dipeptidyl peptidase 4 (DPP4) inhibitors have shown glucose-lowering effects by preserving pancreatic cells in high-fat diet (HFD)/streptozotocin (STZ)-induced diabetic mice, the hepatic role in regulation of glucose homeostasis by DPP4 inhibitors in HFD/STZ mice remains elusive. In herein study, parallel comparison of effects on the liver (expression of gluconeogenic genes and the linked signaling molecules) and pancreas (islet morphology and relative area of alpha or beta cells) in combination with glucose-lowering effects were made at the end of 2- and 10-week of evogliptin treatment in HFD/STZ mice. Significant control of hyperglycemia was observed from the second week and persisted during 10-week treatment of 0.3% evogliptin in HFD/STZ mice. This effect was accompanied by increased level of plasma glucagon-like peptide-1 and preserved pancreas islet structure. Furthermore, the hepatic increases in gluconeogenic gene expression in HFD/STZ mice was significantly reduced by evogliptin treatment, which was accompanied by the suppression of cAMP response element-binding protein (CREB) phosphorylation and expression of transducer of regulated CREB protein 2. This hepatic effect of evogliptin treatment was reproduced in 2-week study, however, pancreatic beta-cell area was not altered yet although the expression of pancreatic and duodenal homeobox protein 1 was increased. We conclude that the suppression of hepatic gluconeogenesis by evogliptin is followed by preservation of pancreatic islet, leading to remarkable and persistent glucose-lowering effect in HFD/STZ mice. Our findings provide further insight for the hepatic role in DPP4 inhibitor-mediated glucose control in diabetes. Topics: Animals; Cyclic AMP Response Element-Binding Protein; Diabetes Mellitus, Experimental; Diabetes Mellitus, Type 2; Diet, High-Fat; Dipeptidyl Peptidase 4; Dipeptidyl-Peptidase IV Inhibitors; Glucagon-Like Peptide 1; Gluconeogenesis; Glucose; Glucose Tolerance Test; Insulin; Insulin-Secreting Cells; Liver; Male; Mice; Mice, Inbred ICR; Pancreas; Piperazines | 2016 |
Weight Loss Decreases Excess Pancreatic Triacylglycerol Specifically in Type 2 Diabetes.
This study determined whether the decrease in pancreatic triacylglycerol during weight loss in type 2 diabetes mellitus (T2DM) is simply reflective of whole-body fat or specific to diabetes and associated with the simultaneous recovery of insulin secretory function.. Individuals listed for gastric bypass surgery who had T2DM or normal glucose tolerance (NGT) matched for age, weight, and sex were studied before and 8 weeks after surgery. Pancreas and liver triacylglycerol were quantified using in-phase, out-of-phase MRI. Also measured were the first-phase insulin response to a stepped intravenous glucose infusion, hepatic insulin sensitivity, and glycemic and incretin responses to a semisolid test meal.. Weight loss after surgery was similar (NGT: 12.8 ± 0.8% and T2DM: 13.6 ± 0.7%) as was the change in fat mass (56.7 ± 3.3 to 45.4 ± 2.3 vs. 56.6 ± 2.4 to 43.0 ± 2.4 kg). Pancreatic triacylglycerol did not change in NGT (5.1 ± 0.2 to 5.5 ± 0.4%) but decreased in the group with T2DM (6.6 ± 0.5 to 5.4 ± 0.4%; P = 0.007). First-phase insulin response to a stepped intravenous glucose infusion did not change in NGT (0.24 [0.13-0.46] to 0.23 [0.19-0.37] nmol ⋅ min(-1) ⋅ m(-2)) but normalized in T2DM (0.08 [-0.01 to -0.10] to 0.22 [0.07-0.30]) nmol ⋅ min(-1) ⋅ m(-2) at week 8 (P = 0.005). No differential effect of incretin secretion was observed after gastric bypass, with more rapid glucose absorption bringing about equivalently enhanced glucagon-like peptide 1 secretion in the two groups.. The fall in intrapancreatic triacylglycerol in T2DM, which occurs during weight loss, is associated with the condition itself rather than decreased total body fat. Topics: Adult; Blood Glucose; Body Weight; Diabetes Mellitus, Type 2; Female; Gastric Bypass; Glucagon-Like Peptide 1; Glucose Tolerance Test; Humans; Incretins; Insulin; Insulin Resistance; Insulin Secretion; Liver; Male; Middle Aged; Pancreas; Randomized Controlled Trials as Topic; Triglycerides; Weight Loss | 2016 |
Time for Glucagon like peptide-1 receptor agonists treatment for patients with NAFLD?
Topics: Diabetes Mellitus, Type 2; Glucagon-Like Peptide 1; Humans; Hypoglycemic Agents; Non-alcoholic Fatty Liver Disease; Peptides | 2016 |
Use of liraglutide in type 1 diabetes: implications for management.
Topics: Diabetes Mellitus, Type 1; Diabetes Mellitus, Type 2; Glucagon-Like Peptide 1; Glycated Hemoglobin; Humans; Hypoglycemic Agents; Liraglutide | 2016 |
Defective insulin secretion by chronic glucagon receptor activation in glucose intolerant mice.
Stimulation of insulin secretion by short-term glucagon receptor (GCGR) activation is well characterized; however, the effect of long-term GCGR activation on β-cell function is not known, but of interest, since hyperglucagonemia occurs early during development of type 2 diabetes. Therefore, we examined whether chronic GCGR activation affects insulin secretion in glucose intolerant mice. To induce chronic GCGR activation, high-fat diet fed mice were continuously (2 weeks) infused with the stable glucagon analog ZP-GA-1 and challenged with oral glucose and intravenous glucose±glucagon-like peptide 1 (GLP1). Islets were isolated to evaluate the insulin secretory response to glucose±GLP1 and their pancreas were collected for immunohistochemical analysis. Two weeks of ZP-GA-1 infusion reduced insulin secretion both after oral and intravenous glucose challenges in vivo and in isolated islets. These inhibitory effects were corrected for by GLP1. Also, we observed increased β-cell area and islet size. We conclude that induction of chronic ZP-GA-1 levels in glucose intolerant mice markedly reduces insulin secretion, and thus, we suggest that chronic activation of the GCGR may contribute to the failure of β-cell function during development of type 2 diabetes. Topics: Animals; Diabetes Mellitus, Type 2; Diet, High-Fat; Female; Glucagon; Glucagon-Like Peptide 1; Glucose; Glucose Intolerance; Glucose Tolerance Test; Insulin; Insulin Secretion; Insulin-Secreting Cells; Mice; Mice, Inbred C57BL; Receptors, Glucagon | 2016 |
Duodenal-Jejunal Bypass Preferentially Elevates Serum Taurine-Conjugated Bile Acids and Alters Gut Microbiota in a Diabetic Rat Model.
Bile acids (BAs) have emerged as important signaling molecules in regulating metabolism and are closely related to gut microbiota. Bariatric surgery elevates serum BAs and affects gut microbiota universally. However, the specific profiles of postsurgical BA components and gut microbiota are still controversial. The aim of this study is to investigate the serum profiles of BA components and gut microbiota after duodenal-jejunal bypass (DJB).. DJB and SHAM procedures were performed in a high-fat-diet/streptozotocin-induced diabetic rat model. Body weight, energy intake, oral glucose tolerance test, insulin tolerance test, HOMA-IR, serum hormones, serum BAs, expression of BA transporters, and gut microbiota were analyzed at week 2 and week 12 postsurgery.. Compared with SHAM, DJB achieved rapid and durable improvement in glucose tolerance and insulin sensitivity, with enhanced GLP-1 secretion. DJB also elevated serum BAs, especially the taurine-conjugated BAs, with upregulation of BA transporters in the terminal ileum. The phylum level of Firmicutes and Proteobacteria abundance was increased postsurgery, at the expense of Bacteroidetes.. DJB preferentially increases serum taurine-conjugated BAs, probably because of more BA reabsorption in the terminal ileum. The gut microbiota is altered with more Firmicutes and Proteobacteria and less Bacteroidetes. Topics: Animals; Bile Acids and Salts; Blood Glucose; Diabetes Mellitus, Type 2; Disease Models, Animal; Duodenum; Gastric Bypass; Gastrointestinal Microbiome; Glucagon-Like Peptide 1; Jejunum; Male; Obesity, Morbid; Rats; Rats, Wistar; Taurine | 2016 |
Effects of gastric bypass on FoxO1 expression in the liver and pancreas of diabetic rats.
To explore the mechanism by which gastric bypass surgery (GBS) ameliorates type 2 diabetes mellitus (T2DM) by investigating whether FoxO1 (a transcription factor that plays a crucial role in the regulation of glycolipid metabolism) expression is altered in the liver and pancreatic islet cells in a rat model of GBS-treated T2DM.. Sprague-Dawley rats were randomly divided into four groups (n = 10 rats each): diabetic rats treated by GBS (DM + GBS), diabetic rats subjected to sham operation (DM + sham), normal control rats (control), and diabetic rats without surgery (DM). Fasting levels of blood glucose (BG), insulin, and glucagon-like peptide-1 (GLP-1) were measured in all groups before and 4, 8, 16, and 24 weeks after operation. Rats were killed 24 weeks after surgery. Liver and pancreas expressions of FoxO1 were investigated by immunohistochemistry and Western blotting analyses.. In the DM + GBS group, fasting BG before and 24 weeks after surgery decreased from 20.2 ± 2.1 to 7.7 ± 1.1 mmol/L, respectively; fasting insulin showed no change (2.9 ± 0.1 and 3.0 ± 0.1 mU/L, respectively); and fasting GLP-1 increased from 8.7 ± 0.9 to 23.5 ± 0.2 pmol/L, respectively. Fasting BG levels after surgery in the DM + GBS group were significantly lower than those in the DM + sham and DM groups. FoxO1 expression levels in the liver and pancreatic islets of the DM + GBS group were reduced compared to those in the DM + sham and DM groups. FoxO1 in the pancreatic β-cells was expressed mainly in the cytoplasm.. Gastric bypass may improve type 2 diabetes mellitus by changing FoxO1 expression in the liver and pancreatic islet cells. Topics: Animals; Blood Glucose; Diabetes Mellitus, Experimental; Diabetes Mellitus, Type 2; Gastric Bypass; Glucagon-Like Peptide 1; Insulin; Liver; Male; Nerve Tissue Proteins; Pancreas; Rats; Rats, Sprague-Dawley | 2016 |
Altered expression of uncoupling protein 2 in GLP-1-producing cells after chronic high glucose exposure: implications for the pathogenesis of diabetes mellitus.
Glucagon-like peptide-1 (GLP-1) is a gut L-cell hormone that enhances glucose-stimulated insulin secretion. Several approaches that prevent GLP-1 degradation or activate the GLP-1 receptor are being used to treat type 2 diabetes mellitus (T2DM) patients. In T2DM, GLP-1 secretion has been suggested to be impaired, and this defect appears to be a consequence rather than a cause of impaired glucose homeostasis. However, although defective GLP-1 secretion has been correlated with insulin resistance, little is known about the direct effects of chronic high glucose concentrations, which are typical in diabetes patients, on GLP-1-secreting cell function. In the present study, we demonstrate that glucotoxicity directly affects GLP-1 secretion in GLUTag cells chronically exposed to high glucose. Our results indicate that this abnormality is associated with a decrease in ATP production due to the elevated expression of mitochondrial uncoupling protein 2 (UCP2). Furthermore, UCP2 inhibition using small interfering RNA (siRNA) and the application of glibenclamide, an ATP-sensitive potassium (KATP(+)) channel blocker, reverse the GLP-1 secretion defect induced by chronic high-glucose treatment. These results show that glucotoxicity diminishes the secretory responsiveness of GLP-1-secreting cells to acute glucose stimulation. We conclude that the loss of the incretin effect, as observed in T2DM patients, could at least partially depend on hyperglycemia, which is typical in diabetes patients. Such an understanding may not only provide new insight into diabetes complications but also ultimately contribute to the identification of novel molecular targets within intestinal L-cells for controlling and improving endogenous GLP-1 secretion. Topics: Animals; Blotting, Western; Cell Line; Diabetes Mellitus, Type 2; Gene Knockdown Techniques; Glucagon-Like Peptide 1; Glucose; Intestinal Mucosa; Ion Channels; Mice; Mitochondrial Proteins; Polymerase Chain Reaction; RNA, Small Interfering; Transfection; Uncoupling Protein 2 | 2016 |
Impaired secretion of glucagon-like peptide 1 during oral glucose tolerance test in patients with newly diagnosed type 2 diabetes mellitus.
To assess glucagon-like peptide 1 (GLP-1) secretion after oral glucose tolerance tests (OGTTs) in subjects with newly diagnosed type 2 diabetes mellitus (T2DM), impaired glucose tolerance (IGT), and normal glucose tolerance (NGT) to clarify changes in GLP-1 secretion during the course of T2DM. . In this cross sectional study, 80 subjects were divided into the NGT, IGT, and T2DM groups after undergoing a 75 g OGTT from March to December 2014 at the School of Medicine, First Affiliated Hospital, Shihezi University, Xinjiang, China. Plasma total GLP-1 was measured at 0, 30, 60, 120, and 180 minutes. Homeostasis model assessment of insulin resistance (HOMA-IR), islet β-cell function (HOMA-β), Gutt index, Matsuda index, incremental GLP-1 (ΔGLP-1), and areas under the curves of GLP-1 (AUCglp-1), glucose (AUCg), and insulin (AUCins) were calculated.. Plasma total GLP-1 at 30-120 minutes and ΔGLP-1 at 30-120 minutes were lower in the T2DM group than in the IGT and NGT groups (p less than 0.05). Peak GLP-1 levels were 35% lower in the T2DM group than in the NGT group. Plasma total GLP-1, ΔGLP-1, and AUCglp-1 correlated negatively with HOMA-IR and AUCg, and positively with HOMA-β, Gutt index, Matsuda index, and AUCins (p less than 0.05). . The GLP-1 secretion after 75 g OGTT was impaired in newly diagnosed T2DM patients, inversely proportional to IR and hyperglycemia, and positively correlated with β-cell function and insulin sensitivity. Topics: Adult; Area Under Curve; Case-Control Studies; Cross-Sectional Studies; Diabetes Mellitus, Type 2; Female; Glucagon-Like Peptide 1; Glucose Intolerance; Glucose Tolerance Test; Humans; Insulin Resistance; Male; Middle Aged | 2016 |
Altered Plasma Levels of Glucagon, GLP-1 and Glicentin During OGTT in Adolescents With Obesity and Type 2 Diabetes.
Proglucagon-derived hormones are important for glucose metabolism, but little is known about them in pediatric obesity and type 2 diabetes mellitus (T2DM).. Fasting and postprandial levels of proglucagon-derived peptides glucagon, GLP-1, and glicentin in adolescents with obesity across the glucose tolerance spectrum were investigated.. This was a cross-sectional study with plasma hormone levels quantified at fasting and during an oral glucose tolerance test (OGTT).. This study took place in a pediatric obesity clinic at Uppsala University Hospital, Sweden.. Adolescents with obesity, age 10-18 years, with normal glucose tolerance (NGT, n = 23), impaired glucose tolerance (IGT, n = 19), or T2DM (n = 4) and age-matched lean adolescents (n = 19) were included.. Outcome measures were fasting and OGTT plasma levels of insulin, glucagon, active GLP-1, and glicentin.. Adolescents with obesity and IGT had lower fasting GLP-1 and glicentin levels than those with NGT (0.25 vs 0.53 pM, P < .05; 18.2 vs 23.6 pM, P < .01) and adolescents with obesity and T2DM had higher fasting glucagon levels (18.1 vs 10.1 pM, P < .01) than those with NGT. During OGTT, glicentin/glucagon ratios were lower in adolescents with obesity and NGT than in lean adolescents (P < .01) and even lower in IGT (P < .05) and T2DM (P < .001).. Obese adolescents with IGT have lowered fasting GLP-1 and glicentin levels. In T2DM, fasting glucagon levels are elevated, whereas GLP-1 and glicentin levels are maintained low. During OGTT, adolescents with obesity have more products of pancreatically than intestinally cleaved proglucagon (ie, more glucagon and less GLP-1) in the plasma. This shift becomes more pronounced when glucose tolerance deteriorates. Topics: Adolescent; Blood Glucose; Case-Control Studies; Child; Cross-Sectional Studies; Diabetes Mellitus, Type 2; Female; Glicentin; Glucagon; Glucagon-Like Peptide 1; Glucose Intolerance; Glucose Tolerance Test; Humans; Male; Pediatric Obesity; Sweden | 2016 |
Activation of Transmembrane Bile Acid Receptor TGR5 Modulates Pancreatic Islet α Cells to Promote Glucose Homeostasis.
The physiological role of the TGR5 receptor in the pancreas is not fully understood. We previously showed that activation of TGR5 in pancreatic β cells by bile acids induces insulin secretion. Glucagon released from pancreatic α cells and glucagon-like peptide 1 (GLP-1) released from intestinal L cells regulate insulin secretion. Both glucagon and GLP-1 are derived from alternate splicing of a common precursor, proglucagon by PC2 and PC1, respectively. We investigated whether TGR5 activation in pancreatic α cells enhances hyperglycemia-induced PC1 expression thereby releasing GLP-1, which in turn increases β cell mass and function in a paracrine manner. TGR5 activation augmented a hyperglycemia-induced switch from glucagon to GLP-1 synthesis in human and mouse islet α cells by GS/cAMP/PKA/cAMP-response element-binding protein-dependent activation of PC1. Furthermore, TGR5-induced GLP-1 release from α cells was via an Epac-mediated PKA-independent mechanism. Administration of the TGR5 agonist, INT-777, to db/db mice attenuated the increase in body weight and improved glucose tolerance and insulin sensitivity. INT-777 augmented PC1 expression in α cells and stimulated GLP-1 release from islets of db/db mice compared with control. INT-777 also increased pancreatic β cell proliferation and insulin synthesis. The effect of TGR5-mediated GLP-1 from α cells on insulin release from islets could be blocked by GLP-1 receptor antagonist. These results suggest that TGR5 activation mediates cross-talk between α and β cells by switching from glucagon to GLP-1 to restore β cell mass and function under hyperglycemic conditions. Thus, INT-777-mediated TGR5 activation could be leveraged as a novel way to treat type 2 diabetes mellitus. Topics: Animals; Benzene Derivatives; Benzenesulfonates; Cell Line; Cholic Acids; Cyclic AMP-Dependent Protein Kinases; Diabetes Mellitus, Experimental; Diabetes Mellitus, Type 2; Estrenes; Gene Expression Regulation; Glucagon-Like Peptide 1; Glucagon-Secreting Cells; Glucose; Homeostasis; Humans; Insulin Resistance; Insulin-Secreting Cells; Male; Mice; Mice, Inbred C57BL; Mice, Transgenic; Paracrine Communication; Proprotein Convertase 1; Proprotein Convertase 2; Pyrrolidinones; Receptors, G-Protein-Coupled; Signal Transduction; Sulfones | 2016 |
Endogenous GLP1 and GLP1 analogue alter CNS responses to palatable food consumption.
Glucagon-like peptide-1 (GLP1) affects appetite, supposedly mediated via the central nervous system (CNS). In this study, we investigate whether modulation of CNS responses to palatable food consumption may be a mechanism by which GLP1 contributes to the central regulation of feeding. Using functional MRI, we determined the effects of endogenous GLP1 and treatment with the GLP1 analogue liraglutide on CNS activation to chocolate milk receipt. Study 1 included 20 healthy lean individuals and 20 obese patients with type 2 diabetes (T2DM). Scans were performed on two occasions: during infusion of the GLP1 receptor antagonist exendin 9-39 (blocking actions of endogenous GLP1) and during placebo infusion. Study 2 was a randomised, cross-over intervention study carried out in 20 T2DM patients, comparing treatment with liraglutide to insulin, after 10 days and 12 weeks. Compared with lean individuals, T2DM patients showed reduced activation to chocolate milk in right insula (P = 0.04). In lean individuals, blockade of endogenous GLP1 effects inhibited activation in bilateral insula (P ≤ 0.03). Treatment in T2DM with liraglutide, vs insulin, increased activation to chocolate milk in right insula and caudate nucleus after 10 days (P ≤ 0.03); however, these effects ceased to be significant after 12 weeks. Our findings in healthy lean individuals indicate that endogenous GLP1 is involved in the central regulation of feeding by affecting central responsiveness to palatable food consumption. In obese T2DM, treatment with liraglutide may improve the observed deficit in responsiveness to palatable food, which may contribute to the induction of weight loss observed during treatment. However, no long-term effects of liraglutide were observed. Topics: Appetite; Blood Glucose; Case-Control Studies; Central Nervous System; Diabetes Mellitus, Type 2; Eating; Female; Glucagon-Like Peptide 1; Humans; Liraglutide; Magnetic Resonance Imaging; Male; Middle Aged; Obesity; Peptide Fragments | 2016 |
Construction of a Fusion Peptide 5rolGLP-HV and Analysis of its Therapeutic Effect on Type 2 Diabetes Mellitus and Thrombosis in Mice.
Glucagon-like peptide-1 (GLP-1), is currently used to treat type 2 diabetes mellitus and hirudin (HV), plays an important role in controlling thrombosis and cardiovascular diseases. This investigation aimed to develop a fusion peptide 5rolGLP-HV which combined functions of rolGLP-1 and rHV to treat diabetes and thrombosis. In this study, we constructed a fusion gene including five copies of rolGLP-1 and one copy of rHV (5rolGLP-HV). The optimum expression conditions of 5rolGLP-HV in a soluble form were 0.8 mM IPTG induction when OD600 reached 0.6-0.8 and further growing at 25 °C for 9 h. Isolated rolGLP-1 and rHV were acquired by trypsin digestion in vitro, and the concentration of them was determined by HPLC in vivo. Oral administration of 5rolGLP-HV significantly decreased the levels of blood glucose, GHbA1C, TC, and TG in diabetic mice at the time of 3 weeks compared to the saline-treated group (p < 0.05), while the insulin level was reversed significantly (p < 0.05). 5rolGLP-HV treatment significantly shortened the length of thrombus in thrombosis mice compared to the saline-treated group (p < 0.01). These results indicated that 5rolGLP-HV had dual-function in treating diabetes and preventing thrombosis. Topics: Animals; Anticoagulants; Blood Glucose; Diabetes Mellitus, Type 2; Glucagon-Like Peptide 1; Hirudins; Humans; Insulin; Mice; Recombinant Fusion Proteins; Thrombosis | 2016 |
Upregulated Pdx1 and MafA Contribute to β-Cell Function Improvement by Sleeve Gastrectomy.
Sleeve gastrectomy is an effective technique for the treatment of severe obesity, and its effects on the improved β-cell function have not yet been fully understood.. From February 2014 to July 2015, sleeve gastrectomy was performed in 5 patients with T2D, who were assessed before and after sleeve gastrectomy (SG). Moreover, a high-fat-diet (HFD) mouse model was also used to study the molecular mechanisms of β-cell functional improvement after SG.. The glucose-stimulated acute insulin response was restored in the T2D patients after SG. The expression of GLP-1 in colonic tissue as well as β-cell specific transcription factors (TFs), Pdx1, and MafA in islets was significantly increased after SG.. β-cell dysfunction can be ameliorated by SG. The re-activation of key TFs contributes to the improvement of β cell function. Topics: Aged; Animals; Diabetes Mellitus, Type 2; Diet, High-Fat; Disease Models, Animal; Gastrectomy; Glucagon-Like Peptide 1; Homeodomain Proteins; Humans; Insulin-Secreting Cells; Maf Transcription Factors, Large; Male; Mice; Mice, Inbred C57BL; Obesity, Morbid; Trans-Activators; Transcription Factors; Up-Regulation | 2016 |
Cost-utility of albiglutide versus insulin lispro, insulin glargine, and sitagliptin for the treatment of type 2 diabetes in the US.
Objective To compare the cost-utility of the glucagon-like peptide-1 receptor agonist albiglutide with those of insulin lispro (both in combination with insulin glargine), insulin glargine, and the dipeptidyl peptidase-4 inhibitor sitagliptin, representing treatments along the type 2 diabetes treatment continuum. Methods The Centre for Outcomes Research and Effectiveness (CORE) Diabetes Model was used for the cost-utility analysis. Data from three Phase 3 clinical trials (HARMONY 6, HARMONY 4, and HARMONY 3) evaluating albiglutide for the treatment of patients with type 2 diabetes were used for the baseline characteristics and treatment effects. Utilities and costs were derived from published sources. Results Albiglutide treatment was associated with an improvement in mean quality-adjusted life expectancy of 0.099, 0.033, and 0.101 years when compared with insulin lispro, insulin glargine, and sitagliptin, respectively. Over the 50-year time horizon, mean total costs in the albiglutide arm were $4332, $2597, and $2223 more than in the other respective treatments. These costs resulted in an incremental cost-utility ratio of $43,541, $79,166, and $22,094 per quality-adjusted life-year (QALY) gained for albiglutide vs insulin lispro, insulin glargine, and sitagliptin, respectively. At a willingness-to-pay threshold of $50,000 per QALY gained, there was a 53.0%, 41.5%, and 67.5% probability of albiglutide being cost-effective compared with the other respective treatments. Limitations This analysis was an extrapolation over a 50-year time horizon based on relatively short-term data obtained during clinical trials. It does not take into account potential differences between the respective treatments in adherence and persistence that can influence both effects and costs. Conclusions Albiglutide represents a reasonable treatment option for patients with type 2 diabetes based on its cost-utility, relative to insulin lispro, insulin glargine, and sitagliptin. Topics: Aged; Body Mass Index; Computer Simulation; Cost-Benefit Analysis; Diabetes Complications; Diabetes Mellitus, Type 2; Dipeptidyl-Peptidase IV Inhibitors; Drug Therapy, Combination; Female; Glucagon-Like Peptide 1; Glycated Hemoglobin; Health Status; Humans; Hypoglycemic Agents; Insulin Glargine; Insulin Lispro; Insulins; Male; Middle Aged; Models, Econometric; Quality-Adjusted Life Years; Sitagliptin Phosphate | 2016 |
Abundance and turnover of GLP-1 producing L-cells in ileal mucosa are not different in patients with and without type 2 diabetes.
The gastrointestinal hormone GLP-1 is released from enteroendocrine L-cells and augments postprandial insulin secretion. In patients with type 2 diabetes, the incretin effect is markedly diminished. It is unclear, whether this is due to a reduction in the abundance of L-cells in the intestine.. Ileal tissue samples from 10 patients with and 10 patients without diabetes that underwent surgery for the removal of colon tumors were included. Tissue sections were stained for GLP-1, Ki67, TUNEL and chromogranin A.. The number of L-cells was not different between patients with and without diabetes in either crypts (1.81±0.21% vs. 1.49±0.24%, respectively; p=0.31) or villi (1.07±0.16% vs. 0.83±0.10%, respectively; p=0.23). L-cell number was higher in crypts than in villi (p<0.0001). L-cell replication was detected rarely and not different between the groups. L-cell apoptosis was similar in patients with and without diabetes in both crypts (7.84±2.77% vs. 8.65±3.77%, p=0.85) and villi (4.48±2.89% vs. 8.62±4.64%, p=0.42). Chromogranin A staining was found in a subset of L-cells only.. Intestinal L-cell density is higher in crypts than in villi. Chromogranin A is not a prerequisite for GLP-1 production. L-cell density and turnover are not different between patients with and without diabetes. Thus, alterations in the number of GLP-1 producing cells do not explain the reduced incretin effect in patients with type 2 diabetes. Topics: Aged; Aged, 80 and over; Biomarkers, Tumor; Cell Count; Chromogranin A; Diabetes Mellitus, Type 2; Enteroendocrine Cells; Female; Glucagon-Like Peptide 1; Humans; Ileum; Intestinal Mucosa; Ki-67 Antigen; Male; Middle Aged | 2016 |
A new GLP-1 analogue with prolonged glucose-lowering activity in vivo via backbone-based modification at the N-terminus.
Glucagon-like peptide-1 (GLP-1) is an endogenous insulinotropic hormone with wonderful glucose-lowering activity. However, its clinical use in type II diabetes is limited due to its rapid degradation at the N-terminus by dipeptidyl peptidase IV (DPP-IV). Among the N-terminal modifications of GLP-1, backbone-based modification was rarely reported. Herein, we employed two backbone-based strategies to modify the N-terminus of tGLP-1. Firstly, the amide N-methylated analogues 2-6 were designed and synthesized to make a full screening of the N-terminal amide bonds, and the loss of GLP-1 receptor (GLP-1R) activation indicated the importance of amide H-bonds. Secondly, with retaining the N-terminal amide H-bonds, the β-peptide replacement strategy was used and analogues 7-13 were synthesized. By two rounds of screening, analogue 10 was identified. Analogue 10 greatly improved the DPP-IV resistance with maintaining good GLP-1R activation in vitro, and showed approximately a 4-fold prolonged blood glucose-lowering activity in vivo in comparison with tGLP-1. This modification strategy will benefit the development of GLP-1-based anti-diabetic drugs. Topics: Blood Glucose; Diabetes Mellitus, Type 2; Glucagon-Like Peptide 1; Humans; Hypoglycemic Agents; Molecular Structure | 2016 |
Importance and methods of searching for E-publications ahead of print in systematic reviews.
Topics: Antibodies, Monoclonal; Antineoplastic Agents; Databases, Bibliographic; Diabetes Mellitus, Type 2; Exenatide; Glucagon-Like Peptide 1; Humans; Hypoglycemic Agents; Ipilimumab; Melanoma; Peptides; Periodicals as Topic; Printing; Review Literature as Topic; Venoms | 2016 |
Effectiveness of Ipragliflozin, a Sodium-Glucose Co-transporter 2 Inhibitor, as a Second-line Treatment for Non-Alcoholic Fatty Liver Disease Patients with Type 2 Diabetes Mellitus Who Do Not Respond to Incretin-Based Therapies Including Glucagon-like Pep
We previously reported that incretin-based drugs, such as dipeptidyl peptidase-4 (DPP-4) inhibitors or glucagon-like peptide-1 (GLP-1) analogs, improved glycemic control and liver inflammation in non-alcoholic fatty liver disease (NAFLD) patients with type 2 diabetes mellitus (T2DM). However, the effect on alanine aminotransferase (ALT) normalization was still limited.. The aim of this study is to elucidate the effectiveness of sodium-glucose co-transporter 2 (SGLT-2) inhibitors as second-line treatments for NAFLD patients with T2DM who do not respond to incretin-based therapy.. We retrospectively enrolled 130 consecutive Japanese NAFLD patients with T2DM who were treated with GLP-1 analogs or DPP-4 inhibitors. Among them, 70 patients (53.8 %) had normal ALT levels. Of the remaining 60 patients (46.2 %) who did not have normal ALT levels, 24 (40.0 %) were enrolled in our study and were administered SGLT-2 inhibitors in addition to GLP-1 analogs or DPP-4 inhibitors. We compared changes in laboratory data including ALT levels and body weight at the end of the follow-up.. Thirteen patients were administered a combination of SGLT-2 inhibitors with DPP-4 inhibitors, and the remaining 11 patients were administered a combination of SGLT-2 inhibitors with GLP-1 analogs. The median dosing period was 320 days. At the end of the follow-up, body weight (from 84.8 to 81.7 kg, p < 0.01) and glycosylated hemoglobin levels (from 8.4 to 7.6 %, p < 0.01) decreased significantly. Serum ALT levels also decreased significantly (from 62 to 38 IU/L, p < 0.01) with an improvement in the FIB-4 index (from 1.75 to 1.39, p = 0.04). Finally, 14 patients (58.3 %) achieved normalization of serum ALT levels.. Administration of SGLT-2 inhibitors led to not only good glycemic control, but also to a reduction in body weight, normalization of ALT levels, and a reduction in the FIB-4 index even in patients who did not respond to incretin-based therapy. Topics: Alanine Transaminase; Diabetes Mellitus, Type 2; Dipeptidyl-Peptidase IV Inhibitors; Female; Glucagon-Like Peptide 1; Glucosides; Humans; Incretins; Liver Cirrhosis; Male; Middle Aged; Non-alcoholic Fatty Liver Disease; Retrospective Studies; Sodium-Glucose Transporter 2; Sodium-Glucose Transporter 2 Inhibitors; Thiophenes; Weight Loss | 2016 |
Exenatide (a GLP-1 agonist) expresses anti-inflammatory properties in cultured human monocytes/macrophages in a protein kinase A and B/Akt manner.
Incretin-based therapies in the treatment of type 2 diabetes mellitus are associated with significant improvements in glycemic control, which are accompanied by a beneficial impact on atherosclerosis. Macrophages are essential in the development of atherosclerotic plaques and may develop features that accelerate atherosclerosis (classically activated macrophages) or protect arterial walls against it (alternatively activated macrophages). Therefore, we explored whether beneficial actions of exenatide are connected with the influence on the macrophages' phenotype and synthesis of inflammatory and anti-inflammatory cytokines.. Monocytes/macrophages were harvested from 10 healthy subjects. Cells were cultured in the presence of exenatide, exendin 9-39 (GLP-1 antagonist), LPS, IL-4, PKI (PKA inhibitor) and triciribine (PKB/Akt inhibitor). We measured the effects of the above-mentioned compounds on markers of macrophages' phenotype (inducible nitrous oxide (iNOS), arginase 1 (arg1) and mannose receptors) and concentration of nitrite, IL-1β, TNF-α and IL-10.. Exenatide significantly increased the level of IL-10 and decreased both TNF-α and IL-1β in LPS-treated monocytes/macrophages. Furthermore exenatide increased the expression of arg1-a marker of classical activation and reduced the LPS-induced expression of iNOS-a marker of classical activation. According to experiments with protein kinases inhibitors we found that proinflammatory markers were protein kinase A dependent, whereas the activation of alternative activation was similarly reliant on protein kinase A and B/Akt.. We showed that exenatide skewed the macrophages phenotype toward anti-inflammatory phenotype and this effect is predominantly attributable to protein kinase A and to a less extent to B/Akt activation. Topics: Anti-Inflammatory Agents; Cells, Cultured; Cyclic AMP-Dependent Protein Kinases; Diabetes Mellitus, Type 2; Exenatide; Glucagon-Like Peptide 1; Humans; Inflammation; Interleukin-10; Interleukin-1beta; Lipopolysaccharides; Macrophages; Monocytes; Nitric Oxide Synthase Type II; Peptides; Proto-Oncogene Proteins c-akt; Tumor Necrosis Factor-alpha; Venoms | 2016 |
Diabetes: Concerns about long-term use of GLP-1 analogues.
Topics: Diabetes Mellitus, Type 2; Glucagon-Like Peptide 1; Humans; Hypoglycemic Agents | 2016 |
Glucagon-like peptide-1 does not have acute effects on central or renal hemodynamics in patients with type 2 diabetes without nephropathy.
During acute administration of native glucagon-like peptide-1 (GLP-1), we previously demonstrated central hemodynamic effects in healthy males, whereas renal hemodynamics, despite renal uptake of GLP-1 in excess of glomerular filtration, was unaffected. In the present study, we studied hemodynamic effects of GLP-1 in patients with type 2 diabetes under fixed sodium intake. During a 3-h infusion of GLP-1 (1.5 pmol·kg(-1)·min(-1)) or saline, intra-arterial blood pressure and heart rate were measured continuously, concomitantly with cardiac output estimated by pulse contour analysis. Renal plasma flow, glomerular filtration rate, and uptake/release of hormones and ions were measured using Fick's Principle after catheterization of a renal vein. Urine collection was conducted throughout the experiments at voluntary voiding, and patients remained supine during the experiments. During the GLP-1 infusion, systolic and diastolic blood pressure and cardiac output remained unchanged, whereas heart rate increased significantly. Arterio-venous gradients for GLP-1 exceeded glomerular filtrations significantly, but renal plasma flow and glomerular filtration rate as well as renal sodium and lithium excretion were not affected. In conclusion, acute administration of GLP-1 in patients with type 2 diabetes leads to a positive chronotropic effect, but in contrast to healthy individuals, cardiac output does not increase in patients with type 2 diabetes. Renal hemodynamics and sodium excretion are not affected. Topics: Blood Pressure; Cardiac Output; Diabetes Mellitus, Type 2; Glomerular Filtration Rate; Glucagon-Like Peptide 1; Heart Rate; Hemodynamics; Humans; Infusions, Intravenous; Kidney; Male; Middle Aged; Natriuresis; Renal Plasma Flow; Sodium | 2016 |
The Dose-Dependent Organ-Specific Effects of a Dipeptidyl Peptidase-4 Inhibitor on Cardiovascular Complications in a Model of Type 2 Diabetes.
Although dipeptidyl peptidase-4 (DPP-4) inhibitors have been suggested to have a non-glucoregulatory protective effect in various tissues, the effects of long-term inhibition of DPP-4 on the micro- and macro-vascular complications of type 2 diabetes remain uncertain. The aim of the present study was to investigate the organ-specific protective effects of DPP-4 inhibitor in rodent model of type 2 diabetes.. Eight-week-old diabetic and obese db/db mice and controls (db/m mice) received vehicle or one of two doses of gemigliptin (0.04 and 0.4%) daily for 12 weeks. Urine albumin excretion and echocardiography measured at 20 weeks of age. Heart and kidney tissue were subjected to molecular analysis and immunohistochemical evaluation.. Gemigliptin effectively suppressed plasma DPP-4 activation in db/db mice in a dose-dependent manner. The HbA1c level was normalized in the 0.4% gemigliptin, but not in the 0.04% gemigliptin group. Gemigliptin showed a dose-dependent protective effect on podocytes, anti-apoptotic and anti-oxidant effects in the diabetic kidney. However, the dose-dependent effect of gemigliptin on diabetic cardiomyopathy was ambivalent. The lower dose significantly attenuated left ventricular (LV) dysfunction, apoptosis, and cardiac fibrosis, but the higher dose could not protect the LV dysfunction and cardiac fibrosis.. Gemigliptin exerted non-glucoregulatory protective effects on both diabetic nephropathy and cardiomyopathy. However, high-level inhibition of DPP-4 was associated with an organ-specific effect on cardiovascular complications in type 2 diabetes. Topics: Albuminuria; Animals; Apoptosis; Cardiomegaly; Cardiovascular Diseases; Diabetes Mellitus, Type 2; Dipeptidyl Peptidase 4; Dipeptidyl-Peptidase IV Inhibitors; Disease Models, Animal; Forkhead Box Protein O3; Forkhead Transcription Factors; Glucagon-Like Peptide 1; Glycated Hemoglobin; Immunohistochemistry; Kidney; Male; Mice; NADPH Oxidases; Piperidones; Podocytes; Proto-Oncogene Proteins c-akt; Pyrimidines; Ventricular Dysfunction | 2016 |
Glucagon-like peptide-1 improves beta-cell antioxidant capacity via extracellular regulated kinases pathway and Nrf2 translocation.
Oxidative stress plays an important role in the development of beta-cell dysfunction and insulin resistance, two major pathophysiological abnormalities of type 2 diabetes. Expression levels of antioxidant enzymes in beta cells are very low, rendering them more susceptible to damage caused by reactive oxygen species (ROS). Although the antioxidant effects of glucagon-like peptide-1 (GLP-1) and its analogs have been previously reported, the exact mechanisms involved are still unclear. In this study, we demonstrated that GLP-1 was able to effectively inhibit oxidative stress and cell death of INS-1E beta cells induced by the pro-oxidant tert-butyl hydroperoxide (tert-BOOH). Incubation with GLP-1 enhanced cellular levels of glutathione and the activity of its related enzymes, glutathione-peroxidase (GPx) and -reductase (GR) in beta cells. However, inhibition of ERK, but not of the PI3K/AKT pathway abolished, at least in part, the antioxidant effect of GLP-1. Moreover, ERK activation seems to be protein kinase A (PKA)-dependent because inhibition of PKA with H-89 was sufficient to block the GLP-1-derived protective effect on beta cells. GLP-1 likewise increased the synthesis of GR and favored the translocation of the nuclear transcription factor erythroid 2p45-related factor (Nrf2), a transcription factor implicated in the expression of several antioxidant/detoxificant enzymes. Glucose-stimulated insulin secretion was also preserved in beta-cells challenged with tert-BOOH but pre-treated with GLP-1, probably through the down-regulation of the mitochondrial uncoupling-protein2 (UCP2). Thus, our results provide additional mechanisms of action of GLP-1 to prevent oxidative damage in beta cells through the modulation of signaling pathways involved in antioxidant enzyme regulation. Topics: Animals; Antioxidants; Cyclic AMP-Dependent Protein Kinases; Diabetes Mellitus, Type 2; Extracellular Signal-Regulated MAP Kinases; Glucagon-Like Peptide 1; Glucose; Glutathione; Glutathione Reductase; Humans; Insulin; Insulin Resistance; Insulin Secretion; Insulin-Secreting Cells; Isoquinolines; NF-E2-Related Factor 2; Oxidative Stress; Rats; Reactive Oxygen Species; Sulfonamides; tert-Butylhydroperoxide; Uncoupling Protein 2 | 2016 |
Effects of different metabolic states and surgical models on glucose metabolism and secretion of ileal L-cell peptides: protocol for a cross-sectional study.
Obesity and type 2 diabetes mellitus are increasing worldwide, reaching pandemic proportions. The understanding of the role of functional restriction and gut hormones can be a beneficial tool in treating obesity and diabetes. However, the exact hormonal profiles in different metabolic states and surgical models are not known.. The HIPER-1 Study is a single-centre cross-sectional study in which 240 patients (in different metabolic states and surgical models) will receive an oral mixed-meal tolerance test (OMTT). At baseline and after 30, 60 and 120 min, peptide YY and glucagon-like peptide 1 levels and glucose and insulin sensitivity will be measured. The primary end point of the study will be the area under the glucagon-like peptide 1 and peptide YY curves after the OMTT. Secondary study end points will include examination of the difference in plasma levels of the distal ileal hormones in subjects with various health statuses and in patients who have been treated with different surgical techniques.. An independent ethics committee, the Institutional Review Board of Istanbul Sisli Kolan International Hospital, Turkey, has approved the study protocol. Dissemination will occur via publication, national and international conference presentations, and exchanges with regional, provincial and national stakeholders.. NCT02532829; Pre-results. Topics: Adult; Blood Glucose; Case-Control Studies; Cross-Sectional Studies; Diabetes Mellitus, Type 2; Digestive System Surgical Procedures; Female; Gastrointestinal Hormones; Glucagon-Like Peptide 1; Glucose Tolerance Test; Humans; Insulin; Insulin Resistance; Male; Middle Aged; Models, Anatomic; Obesity; Peptide YY; Prospective Studies; Research Design; Turkey | 2016 |
Glucagon-like peptide-1 and vitamin D: anti-inflammatory response in diabetic kidney disease in db/db mice and in cultured endothelial cells.
Glucagon-like peptide-1 (GLP-1) is a gut incretin hormone that stimulates insulin secretion and may affect the inflammatory pathways involved in diabetes mellitus. Calcitriol, an active form of vitamin D, plays an important role in renal, endothelial and cardiovascular protection. We evaluated the anti-inflammatory and histologic effects of a GLP-1 analogue (liraglutide) and of calcitriol in a db/db mouse diabetes model and in endothelial cells exposed to a diabetes-like environment.. Diabetic db/db mice were treated with liraglutide and calcitriol for 14 weeks, after which the kidneys were perfused and removed for mRNA and protein analysis and histology. Endothelial cells were stimulated with advanced glycation end products (AGEs), glucose, liraglutide and calcitriol. Total RNA and protein were extracted and analysed for the expression of selected inflammatory markers.. Typical histological changes, glomerular enlargement and mesangial expansion were seen in db/db mice compared with control mice. Glomerular hypertrophy was ameliorated with liraglutide, compared with db/db controls. Liraglutide up-regulated endothelial nitric oxide synthase protein expression compared with the db/db control group and down-regulated p65 protein expression. Calcitriol did not further improve the beneficial effect observed on protein expression. In endothelial cells, liraglutide treatment exhibited a dose-dependent ability to prevent an inflammatory response in the selected markers: thioredoxin-interacting protein, p65, IL6 and IL8. In most gene and protein expressions, addition of calcitriol did not enhance the effect of liraglutide.. The GLP-1 analogue liraglutide prevented the inflammatory response observed in endothelial cells exposed to a diabetes-like environment and in db/db mice at the level of protein expression and significantly ameliorated the glomerular hypertrophy seen in the diabetic control group. Copyright © 2016 John Wiley & Sons, Ltd. Topics: Animals; Anti-Inflammatory Agents; Cells, Cultured; Diabetes Mellitus, Experimental; Diabetes Mellitus, Type 2; Diabetic Nephropathies; Glucagon-Like Peptide 1; Human Umbilical Vein Endothelial Cells; Humans; Incretins; Mice; Mice, Inbred C57BL; Mice, Obese; Vitamin D; Vitamins | 2016 |
Effects of glucagon-like peptide-1 on the differentiation and metabolism of human adipocytes.
Glucagon-like peptide-1 (GLP-1) analogues improve glycaemic control in type 2 diabetic (T2D) patients and cause weight loss in obese subjects by as yet unknown mechanisms. We recently demonstrated that the GLP-1 receptor, which is present in adipocytes and the stromal vascular fraction of human adipose tissue (AT), is up-regulated in AT of insulin-resistant morbidly obese subjects compared with healthy lean subjects. The aim of this study was to explore the effects of in vitro and in vivo administration of GLP-1 and its analogues on AT and adipocyte functions from T2D morbidly obese subjects.. We analysed the effects of GLP-1 on human AT and isolated adipocytes in vitro and the effects of GLP-1 mimetics on AT of morbidly obese T2D subjects in vivo.. GLP-1 down-regulated the expression of lipogenic genes when administered during in vitro differentiation of human adipocytes from morbidly obese patients. GLP-1 also decreased the expression of adipogenic/lipogenic genes in AT explants and mature adipocytes, while increasing that of lipolytic markers and adiponectin. In 3T3-L1 adipocytes, GLP-1 decreased free cytosolic Ca2+ concentration ([Ca2+]i). GLP-1-induced responses were only partially blocked by GLP-1 receptor antagonist exendin (9–39). Moreover, administration of exenatide or liraglutide reduced adipogenic and inflammatory marker mRNA in AT of T2D obese subjects.. Our data suggest that the beneficial effects of GLP-1 are associated with changes in the adipogenic potential and ability of AT to expand, via activation of the canonical GLP-1 receptor and an additional, as yet unknown, receptor. Topics: 3T3-L1 Cells; Adipocytes; Animals; Cell Differentiation; Diabetes Mellitus, Type 2; Exenatide; Gene Expression; Genetic Markers; Glucagon-Like Peptide 1; Humans; Mice; Obesity, Morbid; Peptides; Pilot Projects; Prospective Studies; Venoms | 2016 |
Phenotyping of type 2 diabetes mellitus at onset on the basis of fasting incretin tone: Results of a two-step cluster analysis.
According to some authors, in type 2 diabetes there is a reduced postprandial action of glucagon-like peptide-1 (GLP-1) and glucose-dependent insulinotropic polypeptide (GIP). However, little is known about the role of fasting incretins in glucose homeostasis. Our aim was to evaluate, through a two-step cluster analysis, the possibility of phenotyping patients with type 2 diabetes at onset on the basis of fasting GLP-1, GIP and ghrelin.. A total of 96 patients with type 2 diabetes within 6 months of onset (mean age 62.40 ± 6.36 years) were cross-sectionally studied. Clinical, anthropometric and metabolic parameters were evaluated. At fasting the following were carried out: assay of GLP-1, GIP, ghrelin, insulin, C-peptide, glucagon and a panel of adipocytokines (visfatin, resistin, leptin, soluble leptin receptor and adiponectin).. The analysis resulted in two clusters: cluster 1 (63 patients) had significantly lower levels of GLP-1 (4.93 ± 0.98 vs 7.81 ± 1.98 pmol/L; P < 0.001), GIP (12.73 ± 9.44 vs 23.88 ± 28.56 pmol/L; P < 0.001) and ghrelin (26.54 ± 2.94 vs 39.47 ± 9.84 pmol/L; P < 0.001) compared with cluster 2 (33 patients). Between the two clusters, no differences in age, duration of disease, sex, clinical-anthropometric parameters, insulin sensitivity and adipocytokines were highlighted. However, cluster 1 was associated with significantly higher levels of glycated hemoglobin (7.4 ± 0.61 vs 6.68 ± 0.57%, P = 0.007), glucagon (232.02 ± 37.27 vs 183.33 ± 97.29 ng/L; P = 0.001), fasting glucose (7.85 ± 1.60 vs 6.93 ± 1.01 mmol/L; P = 0.003) and significantly lower levels of C-peptide (0.12 ± 0.11 vs 0.20 ± 0.20 nmol/L; P = 0.017).. The present study suggests that fasting incretins play an important role in the pathophysiology of type 2 diabetes, which requires to further investigation. Topics: Aged; Blood Glucose; Cluster Analysis; Diabetes Mellitus, Type 2; Female; Gastric Inhibitory Polypeptide; Ghrelin; Glucagon-Like Peptide 1; Glucose; Homeostasis; Humans; Incretins; Insulin Resistance; Male; Middle Aged; Phenotype | 2016 |
Diabetes: No increased risk of heart failure with incretin-based drugs.
Topics: Diabetes Mellitus; Diabetes Mellitus, Type 2; Dipeptidyl-Peptidase IV Inhibitors; Glucagon-Like Peptide 1; Heart Failure; Humans; Hypoglycemic Agents; Incretins | 2016 |
Oral hypoglycaemic effect of GLP-1 and DPP4 inhibitor based nanocomposites in a diabetic animal model.
Glucagon-like peptide-1 (GLP-1), an incretin hormone, is used for type 2 diabetes mellitus (T2DM) treatment because of its ability to stimulate insulin secretion and release in a glucose-dependent manner. Despite of its potent insulinotropic effect, oral GLP-1 delivery is greatly limited by its instability in the gastrointestinal tract, poor absorption efficiency and rapid degradation by dipeptidylpeptidase-4 (DPP4) enzyme leading to a short half-life (~2min). Thus, a multistage dual-drug delivery nanosystem was developed to deliver GLP-1 and DPP4 inhibitor simultaneously. The system comprised of chitosan-modified porous silicon (CSUn) nanoparticles, which were coated by an enteric polymer, hydroxypropylmethylcellulose acetate succinate MF, using aerosol flow reactor technology. A non-obese T2DM rat model induced by co-administration of nicotinamide and streptozotocin was used to evaluate the in vivo efficacy of the nanosystem. The oral administration of H-CSUn nanoparticles resulted in 32% reduction in blood glucose levels and ~6.0-fold enhancement in pancreatic insulin content, as compared to the GLP-1+DPP4 inhibitor solution. Overall, these results present a promising system for oral co-delivery of GLP-1 and DPP4 inhibitor that could be further evaluated in a chronic diabetic study. Topics: Administration, Oral; Animals; Blood Glucose; Chitosan; Diabetes Mellitus, Experimental; Diabetes Mellitus, Type 2; Dipeptidyl-Peptidase IV Inhibitors; Drug Therapy, Combination; Glucagon-Like Peptide 1; Intestine, Small; Methylcellulose; Nanocomposites; Nanoparticles; Rats, Wistar; Silicon | 2016 |
Gastrointestinal safety across the albiglutide development programme.
Gastrointestinal (GI) adverse events (AEs) are the most frequently reported treatment-related AEs associated with glucagon-like peptide-1 receptor agonists (GLP-1RAs) in the treatment of type 2 diabetes mellitus. The GI safety of albiglutide, a once-weekly GLP-1RA, was assessed using data from five phase III studies. In a pooled analysis of four placebo-controlled trials, the most common GI AEs were diarrhoea (albiglutide, 14.5% vs. placebo, 11.5%) and nausea (albiglutide, 11.9% vs. placebo, 10.3%), with most patients experiencing 1-2 events. The majority were mild or moderate in intensity and their median duration was 3-4 days. Vomiting occurred in 4.9% of patients in the albiglutide vs. 2.6% in the placebo group. For both albiglutide and placebo, serious GI AEs (2.0% vs. 1.5%) and withdrawals attributable to GI AEs (1.7% vs. 1.5%) were low. In a 32-week trial of albiglutide 50 mg weekly versus liraglutide 1.8 mg daily, nausea occurred in 9.9% of patients in the albiglutide group vs. 29.2% in the liraglutide group. Vomiting occurred in 5.0% in the albiglutide vs. 9.3% in the liraglutide group. In conclusion, albiglutide has an acceptable GI tolerability profile, with nausea and vomiting rates slightly higher than those for placebo but lower than those for liraglutide. Topics: Abdominal Pain; Clinical Trials, Phase III as Topic; Constipation; Diabetes Mellitus, Type 2; Diarrhea; Gastroesophageal Reflux; Gastrointestinal Diseases; Glucagon-Like Peptide 1; Humans; Incretins; Nausea; Severity of Illness Index; Vomiting | 2016 |
Clinical Implications of Cardiovascular Outcome Trials in Type 2 Diabetes: From DCCT to EMPA-REG.
Cardiovascular disease is a major threat to people with diabetes. Attempts have long been made to lower cardiovascular risk by means of glucose-lowering treatment. Initially, it seemed that was an option, but subsequent trials could not verify the original observations and there was concern that some glucose-lowering drugs can actually cause cardiovascular harm. This led medical product agencies in the United States and Europe to require major outcomes trials before accepting new glucose-lowering drugs. The least requirement was noninferiority compared with existing treatment modalities. A large number of such trials have been performed or are ongoing, including >100,000 patients. The drug classes investigated are basal insulin, glucagon-like peptide-1 agonists, dipeptidyl peptidase 4 inhibitors, and sodium-glucose cotransporter-2 (SGLT2) inhibitors. This commentary discusses these trials and their outcomes, the reasons why several of them ended with neutral results (noninferiority), and that the likelihood for showing cardiovascular benefit was minor or even nonexistent. The surprising and highly rewarding impact of the SGLT2 inhibitor empagliflozin is described and potential mechanisms for cardiovascular benefits are discussed. Topics: Benzhydryl Compounds; Cardiovascular Diseases; Clinical Trials as Topic; Diabetes Mellitus, Type 2; Dipeptidyl-Peptidase IV Inhibitors; Glucagon-Like Peptide 1; Glucosides; Humans; Hypoglycemic Agents; Insulin; Risk Factors; Sodium-Glucose Transporter 2; Sodium-Glucose Transporter 2 Inhibitors | 2016 |
PYY-Dependent Restoration of Impaired Insulin and Glucagon Secretion in Type 2 Diabetes following Roux-En-Y Gastric Bypass Surgery.
Roux-en-Y gastric bypass (RYGB) is a weight-reduction procedure resulting in rapid resolution of type 2 diabetes (T2D). The role of pancreatic islet function in this restoration of normoglycemia has not been fully elucidated. Using the diabetic Goto-Kakizaki (GK) rat model, we demonstrate that RYGB restores normal glucose regulation of glucagon and insulin secretion and normalizes islet morphology. Culture of isolated islets with serum from RYGB animals mimicked these effects, implicating a humoral factor. These latter effects were reversed following neutralization of the gut hormone peptide tyrosine tyrosine (PYY) but persisted in the presence of a glucagon-like peptide-1 (GLP-1) receptor antagonist. The effects of RYGB on secretion were replicated by chronic exposure of diabetic rat islets to PYY in vitro. These findings indicate that the mechanism underlying T2D remission may be mediated by PYY and suggest that drugs promoting PYY release or action may restore pancreatic islet function in T2D. Topics: Adult; Animals; Diabetes Mellitus, Type 2; Gastric Bypass; Glucagon; Glucagon-Like Peptide 1; Humans; Insulin; Insulin Secretion; Islets of Langerhans; Male; Peptide YY; Rats, Wistar; Transcription, Genetic | 2016 |
From organophosphate poisoning to diabetes mellitus: The incretin effect.
Organophosphate (OP) poisoning induced disruption of glucose homeostasis is well established. OP poisoning leads to accumulation of acetylcholine (ACh) due to the inhibition of acetylcholinesterases (AChE). On the other hand the incidence of type 2 diabetes mellitus (T2DM) is shown to rise along with the use of pesticides in Southeast Asia. Attenuation of the 'incretin effect' is seen in T2DM. This effect is regulated by a complex loop of mechanism involving ACh driven muscarinic receptors. We hypothesize that OP poisoning leads to disruption of glucose homeostasis by attenuation of the incretin effect. Inhibition of the Glucagon Like Peptide-1 (GLP-1) secretion is our main focus of interest. Positive finding of the hypothesis will open possibility of using incretin based treatment modalities to treat or prevent acute OP induced disruption of glucose homeostasis. Topics: Acetylcholine; Acetylcholinesterase; Animals; Atropine; Diabetes Mellitus, Type 2; Endocrine System; Glucagon-Like Peptide 1; Glucose; Homeostasis; Humans; Incretins; Models, Theoretical; Organophosphate Poisoning; Organophosphates; Treatment Outcome | 2016 |
In vivo dual-delivery of glucagon like peptide-1 (GLP-1) and dipeptidyl peptidase-4 (DPP4) inhibitor through composites prepared by microfluidics for diabetes therapy.
Oral delivery of proteins is still a challenge in the pharmaceutical field. Nanoparticles are among the most promising carrier systems for the oral delivery of proteins by increasing their oral bioavailability. However, most of the existent data regarding nanosystems for oral protein delivery is from in vitro studies, lacking in vivo experiments to evaluate the efficacy of these systems. Herein, a multifunctional composite system, tailored by droplet microfluidics, was used for dual delivery of glucagon like peptide-1 (GLP-1) and dipeptidyl peptidase-4 inhibitor (iDPP4) in vivo. Oral delivery of GLP-1 with nano- or micro-systems has been studied before, but the simultaneous nanodelivery of GLP-1 with iDPP4 is a novel strategy presented here. The type 2 diabetes mellitus (T2DM) rat model, induced through the combined administration of streptozotocin and nicotinamide, a non-obese model of T2DM, was used. The combination of both drugs resulted in an increase in the hypoglycemic effects in a sustained, but prolonged manner, where the iDPP4 improved the therapeutic efficacy of GLP-1. Four hours after the oral administration of the system, blood glucose levels were decreased by 44%, and were constant for another 4 h, representing half of the glucose area under the curve when compared to the control. An enhancement of the plasmatic insulin levels was also observed 6 h after the oral administration of the dual-drug composite system and, although no statistically significant differences existed, the amount of pancreatic insulin was also higher. These are promising results for the oral delivery of GLP-1 to be pursued further in a chronic diabetic model study. Topics: Animals; Blood Glucose; Diabetes Mellitus, Experimental; Diabetes Mellitus, Type 2; Dipeptidyl-Peptidase IV Inhibitors; Enzyme Inhibitors; Glucagon-Like Peptide 1; Hypoglycemic Agents; Insulin; Male; Microfluidics; Rats; Rats, Wistar | 2016 |
Benefits and challenges of a QSP approach through case study: Evaluation of a hypothetical GLP-1/GIP dual agonist therapy.
Quantitative Systems Pharmacology (QSP) is an emerging science with increasing application to pharmaceutical research and development paradigms. Through case study we provide an overview of the benefits and challenges of applying QSP approaches to inform program decisions in the early stages of drug discovery and development. Specifically, we describe the use of a type 2 diabetes systems model to inform a No-Go decision prior to lead development for a potential GLP-1/GIP dual agonist program, enabling prioritization of exploratory programs with higher probability of clinical success. Topics: Cohort Studies; Computer Simulation; Diabetes Mellitus, Type 2; Drug Evaluation, Preclinical; Drug Therapy, Combination; Gastric Inhibitory Polypeptide; Glucagon-Like Peptide 1; Humans; Hypoglycemic Agents; Liraglutide; Pharmacology, Clinical | 2016 |
A bitter pill for type 2 diabetes? The activation of bitter taste receptor TAS2R38 can stimulate GLP-1 release from enteroendocrine L-cells.
The bitter taste receptor TAS2R38 is a G protein coupled receptor (GPCR) that has been found in many extra-oral locations like the gastrointestinal (GI) system, respiratory system, and brain, though its function at these locations is only beginning to be understood. To probe the receptor's potential metabolic role, immunohistochemistry of human ileum tissues was performed, which showed that the receptor was co-localized with glucagon-like peptide 1 (GLP-1) in L-cells. In a previous study, we had modeled the structure of this receptor for its many taste-variant haplotypes (Tan et al. 2011), including the taster haplotype PAV. The structure of this haplotype was then used in a virtual ligand screening pipeline using a collection of ∼2.5 million purchasable molecules from the ZINC database. Three compounds (Z7, Z3, Z1) were purchased from the top hits and tested along with PTU (known TAS2R38 agonist) in in vitro and in vivo assays. The dose-response study of the effect of PTU and Z7 on GLP-1 release using wild-type and TAS2R38 knockout HuTu-80 cells showed that the receptor TAS2R38 plays a major role in GLP-1 release due to these molecules. In vivo studies of PTU and the three compounds showed that they each increase GLP-1 release. PTU was also chemical linked to cellulose to slow its absorption and when tested in vivo, it showed an enhanced and prolonged GLP-1 release. These results suggest that the GI lumen location of TAS2R38 on the L-cell makes it a relatively safe drug target as systemic absorption is not needed for a TAS2R38 agonist drug to effect GLP-1 release. Topics: Animals; Cell Line; Diabetes Mellitus, Type 2; Enteroendocrine Cells; Glucagon-Like Peptide 1; Humans; Ligands; Male; Mice, Inbred BALB C; Molecular Targeted Therapy; Receptors, G-Protein-Coupled | 2016 |
Novel application of hydrophobin in medical science: a drug carrier for improving serum stability.
Multiple physiological properties of glucagon-like peptide-1 (GLP-1) ensure that it is a promising drug candidate for the treatment of type 2 diabetes. However, the in vivo half-life of GLP-1 is short because of rapid degradation by dipeptidyl peptidase-IV (DPP-IV) and renal clearance. The poor serum stability of GLP-1 has significantly limited its clinical utility, although many studies are focused on extending the serum stability of this molecule. Hydrophobin, a self-assembling protein, was first applied as drug carrier to stabilize GLP-1 against protease degradation by forming a cavity. The glucose tolerance test clarified that the complex retained blood glucose clearance activity for 72 hours suggesting that this complex might be utilized as a drug candidate administered every 2-3 days. Additionally, it was found that the mutagenesis of hydrophobin preferred a unique pH condition for self-assembly. These findings suggested that hydrophobin might be a powerful tool as a drug carrier or a pH sensitive drug-release compound. The novel pharmaceutical applications of hydrophobin might result in future widespread interest in hydrophobin. Topics: Animals; Cell Line; Diabetes Mellitus, Experimental; Diabetes Mellitus, Type 2; Dipeptidyl Peptidase 4; Drug Carriers; Fungal Proteins; Glucagon-Like Peptide 1; Glucose Tolerance Test; Half-Life; Humans; Hydrogen-Ion Concentration; Male; Rats | 2016 |
Cardiovascular events and all-cause mortality with insulin versus glucagon-like peptide-1 analogue in type 2 diabetes.
To analyse time to cardiovascular events and mortality in patients with type 2 diabetes (T2D) who received treatment intensification with insulin or a glucagon-like peptide-1 (GLP-1ar) analogue following dual therapy failure with metformin (MET) and sulphonylurea (SU).. A retrospective cohort study was conducted in 2003 patients who were newly treated with a GLP-1ar or insulin following dual therapy (MET+SU) failure between 2006 and 2014. Data were sourced from The Health Improvement Network database. Risks of major adverse cardiovascular events (MACE) (non-fatal myocardial infarction, non-fatal stroke and all-cause mortality) were compared between MET+SU+insulin (N=1584) versus MET+SU+GLP-1ar (N=419). Follow-up was for 5 years (6614 person-years). Propensity score matching analysis and Cox proportional hazard models were employed.. Mean age was 52.8±14.1 years. Overall, the number of MACE was 231 vs 11 for patients who added insulin versus GLP-1ar, respectively (44.5 vs 7.7 per 1000-person-years adjusted HR (aHR): 0.27; 95% CI 0.14 to 0.53; p<0.0001). Insulin was associated with significant increase in weight compared with GLP-1ar (1.78 vs -3.93 kg; p<0.0001) but haemoglobin A1c reduction was similar between both treatment groups (-1.29 vs -0.98; p=0.156). In a subgroup analysis of obese patients (body mass index >30 kg/m(2)) there were 84 vs 11 composite outcomes (38.6 vs 8.1 per 1000 person-years; aHR: 0.31; 95% CI 0.16 to 0.61; p=0.001) in the insulin and GLP-1ar groups, respectively.. In this cohort of obese people with T2DM, intensification of dual oral therapy by adding GLP-1ar analogue is associated with a lower MACE outcome in routine clinical practice, compared with adding insulin therapy as the third glucose-lowering agent. Topics: Adult; Aged; Biomarkers; Blood Glucose; Cardiovascular Diseases; Cause of Death; Databases, Factual; Diabetes Mellitus, Type 2; Drug Therapy, Combination; Female; Glucagon-Like Peptide 1; Glycated Hemoglobin; Humans; Hypoglycemic Agents; Insulin; Kaplan-Meier Estimate; Male; Metformin; Middle Aged; Obesity; Propensity Score; Proportional Hazards Models; Retrospective Studies; Risk Assessment; Risk Factors; Sulfonylurea Compounds; Time Factors; Treatment Outcome; United Kingdom | 2016 |
Clinical effects of liraglutide are possibly influenced by hypertriglyceridemia and remaining pancreatic β-cell function in subjects with type 2 diabetes mellitus.
We searched for factors influencing the clinical effects of GLP-1 analogue liraglutide in subjects with type 2 diabetes. Multivariate analyses showed that hypertriglyceridemia and baseline HbA1c levels were independent predictors for the efficacy of liraglutide and that CPR index was an independent predictor for the durability of liraglutide. Topics: Blood Glucose; Diabetes Mellitus, Type 2; Female; Glucagon-Like Peptide 1; Humans; Hypertriglyceridemia; Hypoglycemic Agents; Insulin-Secreting Cells; Liraglutide; Male; Middle Aged | 2016 |
Endocrine and metabolic diurnal rhythms in young adult men born small vs appropriate for gestational age.
Sleep disturbances and alterations of diurnal endocrine rhythms are associated with increased risk of type 2 diabetes (T2D). We previously showed that young men born small for gestational age (SGA) and with increased risk of T2D have elevated fat and decreased glucose oxidation rates during nighttime. In this study, we investigated whether SGA men have an altered diurnal profile of hormones, substrates and inflammatory markers implicated in T2D pathophysiology compared with matched individuals born appropriate for gestational age (AGA).. We collected hourly blood samples for 24 h, to measure levels of glucose, free fatty acids (FFA), triglycerides (TG), insulin, C-peptide, leptin, resistin, ghrelin, plasminogen activator inhibitor-1 (PAI-1), incretins (GLP-1 and GIP), and inflammatory markers (TNF-α and IL-6) in 13 young men born SGA and 11 young men born AGA.. Repeated measurements analyses were used to analyze the diurnal variations and differences between groups. The SGA subjects had increased 24-h glucose (P=0.03), glucagon (P=0.03) and resistin (P=0.003) levels with no difference in diurnal rhythms compared with AGA controls. We found significant diurnal variations in levels of blood glucose, plasma TG, FFA, insulin, C-peptide, GLP-1, GIP, leptin, visfatin, TNF-α, IL-6 and PAI-1. The variation in FFA levels differed between the groups during the evening. Plasma ghrelin and glucagon levels did not display diurnal variations.. Young men born SGA exhibit elevated 24-h blood glucose, and plasma glucagon and resistin levels with no major differences in diurnal rhythms of these or other key metabolic hormones, substrates or inflammatory markers implicated in the origin of adiposity and T2D. Topics: Blood Glucose; C-Peptide; Circadian Rhythm; Diabetes Mellitus, Type 2; Fatty Acids, Nonesterified; Gestational Age; Ghrelin; Glucagon-Like Peptide 1; Humans; Infant, Newborn; Infant, Small for Gestational Age; Insulin; Interleukin-6; Leptin; Male; Resistin; Triglycerides; Tumor Necrosis Factor-alpha; Young Adult | 2016 |
Cardiovascular safety of glucose-lowering agents as add-on medication to metformin treatment in type 2 diabetes: report from the Swedish National Diabetes Register.
To investigate the relative safety of various glucose-lowering agents as add-on medication to metformin in type 2 diabetes in an observational study linking five national health registers.. Patients with type 2 diabetes who had been on metformin monotherapy and started another agent in addition to metformin were eligible for inclusion. The study period was 2005-2012. Adjusted hazard ratios (HRs) with 95% confidence intervals (CIs) of mortality, cardiovascular disease (CVD), coronary heart disease (CHD), stroke and congestive heart failure (CHF) were estimated using Cox proportional hazards models, weighted for a propensity score.. Of the 20 422 patients included in the study, 43% started on second-line treatment with sulphonylurea (SU), 21% basal insulin, 12% thiazolidinedione (TZD), 11% meglitinide, 10% dipeptidyl peptidase-4 (DPP-4) inhibitor, 1% glucagon-like peptide-1 (GLP-1) receptor agonist and 1% acarbose. At the index date, the mean patient age was ~60 years for all groups except the GLP-1 receptor agonist (56.0 years) and SU (62.9 years) groups. Diabetes duration and glycated haemoglobin levels were similar in all groups. When compared with SU, basal insulin was associated with an 18% higher risk and TZD with a 24% lower risk of mortality [HR 1.18 (95% CI 1.03-1.36) and 0.76 (95% CI 0.62-0.94)], respectively. DPP-4 inhibitor treatment was associated with significantly lower risks of CVD, fatal CVD, CHD, fatal CHD and CHF.. This nationwide observational study showed that second-line treatment with TZD and DPP-4 inhibitor as add-on medication to metformin were associated with significantly lower risks of mortality and cardiovascular events compared with SU, whereas basal insulin was associated with a higher risk of mortality. Topics: Aged; Blood Glucose; Cardiotoxicity; Cardiovascular Diseases; Coronary Disease; Diabetes Mellitus, Type 2; Dipeptidyl-Peptidase IV Inhibitors; Drug Therapy, Combination; Female; Glucagon-Like Peptide 1; Heart Failure; Humans; Hypoglycemic Agents; Insulin; Male; Metformin; Middle Aged; Registries; Sulfonylurea Compounds; Sweden; Thiazolidinediones; Treatment Outcome | 2016 |
The Shape of the Glucose Response Curve During an Oral Glucose Tolerance Test Heralds Biomarkers of Type 2 Diabetes Risk in Obese Youth.
The shape of the glucose response curve during an oral glucose tolerance test (OGTT), monophasic versus biphasic, identifies physiologically distinct groups of individuals with differences in insulin secretion and sensitivity. We aimed to verify the value of the OGTT-glucose response curve against more sensitive clamp-measured biomarkers of type 2 diabetes risk, and to examine incretin/pancreatic hormones and free fatty acid associations in these curve phenotypes in obese adolescents without diabetes.. A total of 277 obese adolescents without diabetes completed a 2-h OGTT and were categorized to either a monophasic or a biphasic group. Body composition, abdominal adipose tissue, OGTT-based metabolic parameters, and incretin/pancreatic hormone levels were examined. A subset of 106 participants had both hyperinsulinemic-euglycemic and hyperglycemic clamps to measure in vivo insulin sensitivity, insulin secretion, and β-cell function relative to insulin sensitivity.. Despite similar fasting and 2-h glucose and insulin concentrations, the monophasic group had significantly higher glucose, insulin, C-peptide, and free fatty acid OGTT areas under the curve compared with the biphasic group, with no differences in levels of glucagon, total glucagon-like peptide 1, glucose-dependent insulinotropic polypeptide, and pancreatic polypeptide. Furthermore, the monophasic group had significantly lower in vivo hepatic and peripheral insulin sensitivity, lack of compensatory first and second phase insulin secretion, and impaired β-cell function relative to insulin sensitivity.. In obese youth without diabetes, the risk imparted by the monophasic glucose curve compared with biphasic glucose curve, independent of fasting and 2-h glucose and insulin concentrations, is reflected in lower insulin sensitivity and poorer β-cell function, which are two major pathophysiological biomarkers of type 2 diabetes in youth. Topics: Adiposity; Adolescent; Biomarkers; Blood Glucose; Body Composition; Body Mass Index; C-Peptide; Cross-Sectional Studies; Diabetes Mellitus, Type 2; Female; Gastric Inhibitory Polypeptide; Glucagon; Glucagon-Like Peptide 1; Glucose Tolerance Test; Glycated Hemoglobin; Humans; Incretins; Insulin; Insulin Secretion; Male; Pediatric Obesity; Risk Factors | 2016 |
Finding a Potential Dipeptidyl Peptidase-4 (DPP-4) Inhibitor for Type-2 Diabetes Treatment Based on Molecular Docking, Pharmacophore Generation, and Molecular Dynamics Simulation.
Dipeptidyl peptidase-4 (DPP-4) is the vital enzyme that is responsible for inactivating intestinal peptides glucagon like peptide-1 (GLP-1) and Gastric inhibitory polypeptide (GIP), which stimulates a decline in blood glucose levels. The aim of this study was to explore the inhibition activity of small molecule inhibitors to DPP-4 following a computational strategy based on docking studies and molecular dynamics simulations. The thorough docking protocol we applied allowed us to derive good correlation parameters between the predicted binding affinities (pKi) of the DPP-4 inhibitors and the experimental activity values (pIC50). Based on molecular docking receptor-ligand interactions, pharmacophore generation was carried out in order to identify the binding modes of structurally diverse compounds in the receptor active site. Consideration of the permanence and flexibility of DPP-4 inhibitor complexes by means of molecular dynamics (MD) simulation specified that the inhibitors maintained the binding mode observed in the docking study. The present study helps generate new information for further structural optimization and can influence the development of new DPP-4 inhibitors discoveries in the treatment of type-2 diabetes. Topics: Binding Sites; Catalytic Domain; Diabetes Mellitus, Type 2; Dipeptidyl Peptidase 4; Dipeptidyl-Peptidase IV Inhibitors; Glucagon-Like Peptide 1; Humans; Hydrogen Bonding; Hypoglycemic Agents; Molecular Conformation; Molecular Docking Simulation; Molecular Dynamics Simulation; Protein Binding; Structure-Activity Relationship | 2016 |
Oxyntomodulin Identified as a Marker of Type 2 Diabetes and Gastric Bypass Surgery by Mass-spectrometry Based Profiling of Human Plasma.
Low-abundance regulatory peptides, including metabolically important gut hormones, have shown promising therapeutic potential. Here, we present a streamlined mass spectrometry-based platform for identifying and characterizing low-abundance regulatory peptides in humans. We demonstrate the clinical applicability of this platform by studying a hitherto neglected glucose- and appetite-regulating gut hormone, namely, oxyntomodulin. Our results show that the secretion of oxyntomodulin in patients with type 2 diabetes is significantly impaired, and that its level is increased by more than 10-fold after gastric bypass surgery. Furthermore, we report that oxyntomodulin is co-distributed and co-secreted with the insulin-stimulating and appetite-regulating gut hormone glucagon-like peptide-1 (GLP-1), is inactivated by the same protease (dipeptidyl peptidase-4) as GLP-1 and acts through its receptor. Thus, oxyntomodulin may participate with GLP-1 in the regulation of glucose metabolism and appetite in humans. In conclusion, this mass spectrometry-based platform is a powerful resource for identifying and characterizing metabolically active low-abundance peptides. Topics: Animals; Biomarkers; Diabetes Mellitus, Type 2; Dipeptidyl Peptidase 4; Disease Models, Animal; Gastric Bypass; Glucagon-Like Peptide 1; Humans; Mass Spectrometry; Mice; Oxyntomodulin; Proteomics | 2016 |
South Asian consensus guideline: Use of GLP-1 receptor agonists during Ramadan: Update 2016 Revised Guidelines on the use of GLP-1A in Ramadan.
This guidance is an update to the South Asian Consensus Guideline: Use of GLP1RA in Diabetes during Ramadan, published in the Indian Journal of Endocrinology and Metabolism in 2012. A five country working group has collated evidence and experience to suggest guidelines for the safe and rational use of glucagon-like peptide1 receptor agonists during Ramadan. The suggestions contained herewith are based upon recently published evidence as well as available basic pharmacological data. Topics: Diabetes Mellitus, Type 2; Fasting; Glucagon-Like Peptide 1; Glucagon-Like Peptide-1 Receptor; Humans; Hypoglycemic Agents; Islam; Liraglutide; Peptide Fragments; Peptides; Practice Guidelines as Topic; Venoms | 2016 |
Access to diabetes drugs in New Zealand is inadequate.
Topics: Diabetes Mellitus, Type 2; Dipeptidyl-Peptidase IV Inhibitors; Drug Costs; Financing, Government; Glucagon-Like Peptide 1; Glycated Hemoglobin; Health Services Accessibility; Healthcare Financing; Humans; Hypoglycemia; Hypoglycemic Agents; New Zealand; Practice Guidelines as Topic; Sodium-Glucose Transporter 2 Inhibitors | 2016 |
Endocrine effects of duodenal-jejunal exclusion in obese patients with type 2 diabetes mellitus.
Duodenal-jejunal bypass liner (DJBL) is an endoscopically implantable device designed to noninvasively mimic the effects of gastrointestinal bypass operations by excluding the duodenum and proximal jejunum from the contact with ingested food. The aim of our study was to assess the influence of DJBL on anthropometric parameters, glucose regulation, metabolic and hormonal profile in obese patients with type 2 diabetes mellitus (T2DM) and to characterize both the magnitude and the possible mechanisms of its effect. Thirty obese patients with poorly controlled T2DM underwent the implantation of DJBL and were assessed before and 1, 6 and 10months after the implantation, and 3months after the removal of DJBL. The implantation decreased body weight, and improved lipid levels and glucose regulation along with reduced glycemic variability. Serum concentrations of fibroblast growth factor 19 (FGF19) and bile acids markedly increased together with a tendency to restoration of postprandial peak of GLP1. White blood cell count slightly increased and red blood cell count decreased throughout the DJBL implantation period along with decreased ferritin, iron and vitamin B12 concentrations. Blood count returned to baseline values 3months after DJBL removal. Decreased body weight and improved glucose control persisted with only slight deterioration 3months after DJBL removal while the effect on lipids was lost. We conclude that the implantation of DJBL induced a sustained reduction in body weight and improvement in regulation of lipid and glucose. The increase in FGF19 and bile acids levels could be at least partially responsible for these effects. Topics: Adult; Aged; Bariatric Surgery; Bile Acids and Salts; Blood Glucose; Diabetes Mellitus, Type 2; Duodenum; Female; Fibroblast Growth Factors; Glucagon-Like Peptide 1; Humans; Jejunum; Lipids; Male; Middle Aged; Obesity; Postoperative Period; Postprandial Period; Time Factors; Treatment Outcome; Weight Loss | 2016 |
Association of Bile Duct and Gallbladder Diseases With the Use of Incretin-Based Drugs in Patients With Type 2 Diabetes Mellitus.
The use of dipeptidyl-peptidase-4 (DPP-4) inhibitors and glucagon-like peptide 1 (GLP-1) analogues-a group of drugs used in the management of type 2 diabetes mellitus-may be associated with an increased risk of bile duct and gallbladder disease. To date, no observational study has assessed this possible association.. To determine whether the use of DPP-4 inhibitors and GLP-1 analogues is associated with an increased risk of incident bile duct and gallbladder disease in patients with type 2 diabetes.. A population-based cohort study linked the United Kingdom Clinical Practice Research Datalink with the Hospital Episodes Statistics database, yielding a cohort of 71 369 patients, 18 years or older, initiating an antidiabetic drug (including oral and injectable agents) between January 1, 2007, and March 31, 2014.. Current use of DPP-4 inhibitors and GLP-1 analogues (alone or in combination therapy) compared with current use of at least 2 oral antidiabetic drugs.. Time-dependent Cox proportional hazards models were used to estimate hazard ratios (HRs) with 95% CIs of incident bile duct or gallbladder events (cholelithiasis, cholecystitis, cholangitis) causing hospitalization, comparing current use of DPP-4 inhibitors and GLP-1 analogues with current use of at least 2 oral antidiabetic drugs.. During 227 994 person-years of follow-up, 853 of the 71 369 patients were hospitalized for bile duct and gallbladder disease (incidence rate per 1000 person-years, 3.7; 95% CI, 3.5-4.0). Current use of DPP-4 inhibitors was not associated with an increased risk of bile duct and gallbladder disease compared with current use of at least 2 oral antidiabetic drugs (3.6 vs 3.3 per 1000 person-years; adjusted HR, 0.99; 95% CI, 0.75-1.32). In contrast, the use of GLP-1 analogues was associated with an increased risk of bile duct and gallbladder disease compared with current use of at least 2 oral antidiabetic drugs (6.1 vs 3.3 per 1000 person-years; adjusted HR, 1.79; 95% CI, 1.21-2.67). In a secondary analysis, GLP-1 analogues were also associated with an increased risk of cholecystectomy (adjusted HR, 2.08; 95% CI, 1.08-4.02).. The use of GLP-1 analogues was associated with an increased risk of bile duct and gallbladder disease. Physicians should be aware of this potential adverse event when prescribing these drugs. Topics: Adult; Bile Duct Diseases; Cholecystectomy; Cohort Studies; Diabetes Mellitus, Type 2; Dipeptidyl-Peptidase IV Inhibitors; Female; Gallbladder Diseases; Glucagon-Like Peptide 1; Humans; Hypoglycemic Agents; Incidence; Male; Proportional Hazards Models; United Kingdom | 2016 |
Glucagon-like Peptide 1 Drugs as Second-line Therapy for Type 2 Diabetes.
Topics: Blood Glucose; Diabetes Mellitus, Type 2; Glucagon-Like Peptide 1; Glucagon-Like Peptide-1 Receptor; Humans; Hypoglycemic Agents; Insulin | 2016 |
Association Between Incretin-Based Drugs and the Risk of Acute Pancreatitis.
The association between incretin-based drugs, such as dipeptidyl peptidase 4 (DPP-4) inhibitors and glucagon-like peptide 1 (GLP-1) agonists, and acute pancreatitis is controversial.. To determine whether the use of incretin-based drugs, compared with the use of 2 or more other oral antidiabetic drugs, is associated with an increased risk of acute pancreatitis.. A large, international, multicenter, population-based cohort study was conducted using combined health records from 7 participating sites in Canada, the United States, and the United Kingdom. An overall cohort of 1 532 513 patients with type 2 diabetes initiating the use of antidiabetic drugs between January 1, 2007, and June 30, 2013, was included, with follow-up until June 30, 2014.. Current use of incretin-based drugs compared with current use of at least 2 oral antidiabetic drugs.. Nested case-control analyses were conducted including hospitalized patients with acute pancreatitis matched with up to 20 controls on sex, age, cohort entry date, duration of treated diabetes, and follow-up duration. Hazard ratios (HRs) and 95% CIs for hospitalized acute pancreatitis were estimated and compared current use of incretin-based drugs with current use of 2 or more oral antidiabetic drugs. Secondary analyses were performed to assess whether the risk varied by class of drug (DPP-4 inhibitors and GLP-1 agonists) or by duration of use. Site-specific HRs were pooled using random-effects models.. Of 1 532 513 patients included in the analysis, 781 567 (51.0%) were male; mean age was 56.6 years. During 3 464 659 person-years of follow-up, 5165 patients were hospitalized for acute pancreatitis (incidence rate, 1.49 per 1000 person-years). Compared with current use of 2 or more oral antidiabetic drugs, current use of incretin-based drugs was not associated with an increased risk of acute pancreatitis (pooled adjusted HR, 1.03; 95% CI, 0.87-1.22). Similarly, the risk did not vary by drug class (DPP-4 inhibitors: pooled adjusted HR, 1.09; 95% CI, 0.86-1.22; GLP-1 agonists: pooled adjusted HR, 1.04; 95% CI, 0.81-1.35) and there was no evidence of a duration-response association.. In this large population-based study, use of incretin-based drugs was not associated with an increased risk of acute pancreatitis compared with other oral antidiabetic drugs. Topics: Adolescent; Adult; Aged; Canada; Case-Control Studies; Cohort Studies; Diabetes Mellitus, Type 2; Dipeptidyl-Peptidase IV Inhibitors; Female; Glucagon-Like Peptide 1; Humans; Hypoglycemic Agents; Incretins; Male; Middle Aged; Pancreatitis; United Kingdom; United States; Young Adult | 2016 |
Glucagon like peptide-1 receptor agonists may ameliorate the metabolic adverse effect associated with antiretroviral therapy.
The number of people living with HIV and AIDS (PLWHA) reached to almost 40 million, half of which are under antiretroviral treatment (ART). Although the introduction of this therapy significantly improved the life span and quality of PLWHA, metabolic complications of these people remains to be an important issue. These metabolic complications include hyperlipidemia, abnormal fat redistribution and diabetes mellitus, which are defined as lipodystrophy syndrome. Glucagon-like peptide-1 (GLP-1) is a neuropeptide secreted from intestinal L cells and recently developed GLP-1 receptor agonists (GLP-1RAs) stimulate insulin secretion, improve weight control and reduce cardiovascular outcomes. This class of drugs may be a valuable medication in the treatment of HIV-associated metabolic adverse effects and extend the life expectancy of patients infected with HIV. Topics: Acquired Immunodeficiency Syndrome; Anti-Retroviral Agents; Body Weight; Diabetes Mellitus; Diabetes Mellitus, Type 2; Disease Progression; Glucagon-Like Peptide 1; Glucagon-Like Peptide-1 Receptor; HIV Infections; Humans; Hyperlipidemias; Hypoglycemic Agents; Life Expectancy; Lipodystrophy; Models, Theoretical; Subcutaneous Fat; Treatment Outcome | 2016 |
Therapy: Gastrointestinal risks of incretin-based drugs.
Topics: Diabetes Mellitus, Type 2; Glucagon-Like Peptide 1; Humans; Hypoglycemic Agents; Incretins | 2016 |
Functional and Molecular Adaptations of Enteroendocrine L-Cells in Male Obese Mice Are Associated With Preservation of Pancreatic α-Cell Function and Prevention of Hyperglycemia.
Glucose homeostasis depends on the coordinated secretion of glucagon, insulin, and Glucagon-like peptide (GLP)-1 by pancreas and intestine. Obesity, which is associated with an increased risk of developing insulin resistance and type 2 diabetes, affects the function of these organs. Here, we investigate the functional and molecular adaptations of proglucagon-producing cells in obese mice to better define their involvement in type 2 diabetes development. We used GLU-Venus transgenic male mice specifically expressing Venus fluorochrome in proglucagon-producing cells. Mice were subjected to 16 weeks of low-fat diet or high-fat diet (HFD) and then subdivided by measuring glycated hemoglobin (HbA1c) in 3 groups: low-fat diet mice and I-HFD (glucose-intolerant) mice with similar HbA1c and H-HFD (hyperglycemic) mice, which exhibited higher HbA1c. At 16 weeks, both HFD groups exhibited similar weight gain, hyperinsulinemia, and insulin resistance. However, I-HFD mice exhibited better glucose tolerance compared with H-HFD mice. I-HFD mice displayed functional and molecular adaptations of enteroendocrine L-cells resulting in increased intestinal GLP-1 biosynthesis and release as well as maintained pancreatic α- and β-cell functions. By contrast, H-HFD mice exhibited dysfunctional L, α- and β-cells with increased β- and L-cell numbers. Administration of the GLP-1R antagonist Exendin9-39 in I-HFD mice led to hyperglycemia and alterations of glucagon secretion without changes in insulin secretion. Our results highlight the cross-talk between islet and intestine endocrine cells and indicate that a compensatory adaptation of L-cell function in obesity plays an important role in preserving glucose homeostasis through the control of pancreatic α-cell functions. Topics: Animals; Diabetes Mellitus, Type 2; Diet, High-Fat; Enteroendocrine Cells; Glucagon; Glucagon-Like Peptide 1; Glucagon-Secreting Cells; Hyperglycemia; Insulin-Secreting Cells; Male; Mice, Inbred C57BL; Mice, Transgenic; Obesity; Peptide Fragments; Phenotype | 2016 |
Glucagon-Like Peptide-1 Receptor Agonists and Diabetic Cardiovascular Disease: Implications of the LEADER Study.
Topics: Cardiovascular Diseases; Diabetes Mellitus, Type 2; Glucagon-Like Peptide 1; Glucagon-Like Peptide-1 Receptor; Humans; Hypoglycemic Agents | 2016 |
Esophageal and Gastric Dysmotilities are Associated with Altered Glucose Homeostasis and Plasma Levels of Incretins and Leptin.
Gastrointestinal complications in diabetes may affect glucose and endocrine homeostasis. Glucose-dependent insulinotropic peptide (GIP), glucagon-like peptide-1 (GLP-1), and leptin regulate glucose homeostasis, food intake, and gastric emptying.. The aim was to investigate associations between diabetes complications and glucose homeostasis and plasma levels of GIP, GLP-1, and leptin.. Sixteen diabetes patients (seven men) were examined with gastric emptying scintigraphy and 72-h continuous subcutaneous glucose monitoring, 14 with the deep-breathing test, and 12 with esophageal manometry. A fiber-rich breakfast was given during the second day of glucose registration. Blood samples were taken 10 min and right before a fat-rich breakfast, as well as 10, 20, 30, 45, 60, 90, 120, 150, and 180 min afterwards. 20 healthy volunteers acted as controls. Plasma was analyzed regarding GIP, GLP-1, and leptin by Luminex.. Gastroparesis lowered maximal concentration (c-max) (p = 0.003) and total area under the curve (tAUC) (p = 0.019) of glucose levels as well as d-min (p = 0.043) of leptin levels. It tended to lower baseline (p = 0.073), c-max (p = 0.066), change from baseline (d-max) (p = 0.073), and tAUC (p = 0.093) of GLP-1 concentrations. Esophageal dysmotility tended to lower tAUC of glucose levels (p = 0.063), and c-min (p = 0.065) and tAUC (p = 0.063) of leptin levels. Diabetes patients had a higher baseline concentration of glucose (p = 0.013), GIP (p = 0.023), and leptin (p = 0.019) compared with healthy subjects.. Gastric and esophageal dysmotility are associated with both lesser increases in postprandial glucose elevations and decreased postprandial changes in GLP-1 and leptin. Topics: Adult; Blood Glucose; Diabetes Mellitus, Type 2; Esophageal Motility Disorders; Female; Gastric Inhibitory Polypeptide; Gastroparesis; Glucagon-Like Peptide 1; Humans; Insulin; Leptin; Male; Middle Aged; Postprandial Period | 2016 |
Beneficial Metabolic Effects of Duodenal Jejunal Bypass Liner for the Treatment of Adipose Patients with Type 2 Diabetes Mellitus: Analysis of Responders and Non-Responders.
Implantation of a duodenal-jejunal endoluminal bypass liner (DJBL) has shown to induce weight loss and to improve metabolic parameters. DJBL is a reversible endoduodenal sleeve mimicking duodenal bypass while lacking risks and limitations of bariatric surgery.Effects on metabolic control, body mass parameters, appetite regulation, glucose tolerance, organ health, and lipid profile were determined in 16 morbidly overweight patients with type 2 diabetes mellitus. In addition, relevant hormones (leptin, ghrelin, gastric inhibitory peptide, glucagon-like peptide, and insulin) were measured by enzyme-linked immunosorbent assay (ELISA) and chemiluminescent microparticle immunoassay (CMIA) at 0, 1, 32, and 52 weeks post-implant following a mixed meal tolerance test. Lipoprotein subclasses were analysed by proton nuclear magnetic resonance ( Topics: Adiposity; Adult; Aged; Bariatric Surgery; Blood Glucose; Case-Control Studies; Diabetes Mellitus, Type 2; Duodenum; Female; Follow-Up Studies; Gastric Inhibitory Polypeptide; Glucagon; Glucagon-Like Peptide 1; Humans; Insulin; Insulin Secretion; Jejunum; Male; Middle Aged; Obesity, Morbid; Treatment Outcome; Weight Loss | 2016 |
Combined insulin/GLP-1 pens near market.
Topics: Diabetes Mellitus, Type 2; Drug Approval; Drug Combinations; Glucagon-Like Peptide 1; Humans; Hypoglycemic Agents; Insulin; United States; United States Food and Drug Administration | 2016 |
GLP-1 receptor agonists and SGLT2 inhibitors: a couple at last?
Topics: Diabetes Mellitus, Type 2; Dipeptidyl-Peptidase IV Inhibitors; Glucagon-Like Peptide 1; Glucagon-Like Peptide-1 Receptor; Humans; Hypoglycemic Agents; Sodium-Glucose Transporter 2 | 2016 |
Comment on the FLAT-SUGAR Trial Investigators. Glucose Variability in a 26-Week Randomized Comparison of Mealtime Treatment With Rapid-Acting Insulin Versus GLP-1 Agonist in Participants With Type 2 Diabetes at High Cardiovascular Risk. Diabetes Care 2016
Topics: Blood Glucose; Cardiovascular Diseases; Diabetes Mellitus, Type 2; Glucagon-Like Peptide 1; Glucose; Humans; Hypoglycemic Agents; Insulin; Insulin, Short-Acting; Research Personnel; Risk Factors; Sugars | 2016 |
Response to Comment on the FLAT-SUGAR Trial Investigators. Glucose Variability in a 26-Week Randomized Comparison of Mealtime Treatment With Rapid-Acting Insulin Versus GLP-1 Agonist in Participants With Type 2 Diabetes at High Cardiovascular Risk. Diabet
Topics: Blood Glucose; Cardiovascular Diseases; Diabetes Mellitus, Type 2; Glucagon-Like Peptide 1; Glucose; Humans; Hypoglycemic Agents; Insulin; Insulin, Short-Acting; Research Personnel; Risk Factors; Sugars | 2016 |
Diabetes: Cardiovascular benefits of semaglutide.
Topics: Cardiovascular Diseases; Diabetes Mellitus, Type 2; Glucagon-Like Peptide 1; Glucagon-Like Peptides; Humans | 2016 |
Effect of Resected Gastric Volume on Ghrelin and GLP-1 Plasma Levels: a Prospective Study.
The correlation between resected gastric volume (RGV) and neuro-humoral changes (ghrelin and GLP-1) after laparoscopic sleeve gastrectomy (LSG) and their effects on type 2 diabetes mellitus (T2DM) has been evaluated.. Ninety-eight patients were divided in two groups: RGV <1200 mL (group A: 53 pts) and RGV >1200 mL (group B: 45 pts). Insulin secretion (insulin area under the curve (AUC)), insulinogenic index (IGI) and insulin-resistance (homeostasis model assessment, HOMA. A significant difference in T2DM resolution rate was observed after 6, 12 and 24 months in favour of RGV >1200 mL. Group B performed better than group A at the 3rd day and at the 6th, 12th and 24th months with regard to AUC, IGI and HOMA. Ghrelin and GLP-1 changes play a role in the regulation of glucose metabolism during the 1st year after LSG. RGV influences ghrelin and GLP-1 plasma levels after LSG, with a significant improvement in the T2DM control. Topics: Adult; Bariatric Surgery; Diabetes Mellitus, Type 2; Female; Gastrectomy; Ghrelin; Glucagon-Like Peptide 1; Glucose Tolerance Test; Humans; Insulin; Insulin Resistance; Insulin Secretion; Laparoscopy; Male; Middle Aged; Obesity, Morbid; Organ Size; Postoperative Period; Preoperative Period; Prospective Studies; Stomach | 2016 |
Prescribing differences in family practice for diabetic patients in Germany according to statutory or private health insurance: the case of DPP-4-inhibitors and GLP-1-agonists.
The objective of this study was to analyze prescription decisions for family practice (FP) patients with Diabetes mellitus type 2 (DM2) using the case of the incretin mimetics Dipeptidyl peptidase-4 (DDP-4) inhibitors and Glucagon-like peptide-1 (GLP-1) agonists dependent on patients' health insurance status (statutory or private) in Germany. This study is important since the scientific debate is still open with regard to DPP-4-inhibitors and GLP-1-agonists, where some critics are raising questions on potential long-term risks for patients.. Data for this analysis were sourced from the German health services research register CONTENT (CONTinuous morbidity registration Epidemiologic NeTwork), in which FP health services information, generated by family practitioners, is continuously collated, e.g. patients' health insurance status, morbidity and pharmacotherapy. Patients with Diabetes mellitus type 1 (DM1) were excluded from the study.. From the family practices collaborating in the CONTENT research network, there were 7298 patients treated with pharmacotherapeutic agents for DM2 between 01.09.2009 and 31.08.2014. 586 (8.03 %) of these patients had private insurance. Prescriptions for the incretin mimetics were 40.6 % higher (9.7 vs. 6.9 %; p < 0.0001) for patients with private insurance compared to patients with statutory health insurance. This finding was confirmed with multivariable analyses.. There was a statistically significant difference found in prescription patterns according to the patient's health insurance status for the incretin mimetics in this sample population of German patients with DM2. Obviously, these differences result from the eligibility for reimbursement according to patients' health insurance status. Whether incretin mimetics pose specific long term risks for particular patients is yet to be determined. Topics: Aged; Aged, 80 and over; Diabetes Mellitus, Type 2; Dipeptidyl-Peptidase IV Inhibitors; Drug Prescriptions; Family Practice; Female; Germany; Glucagon-Like Peptide 1; Humans; Incretins; Insurance, Health; Male; Middle Aged; Peptidomimetics; Practice Patterns, Physicians' | 2016 |
[Glucagon-like peptide 1 improves learning and memory abilities of rats with type 2 diabetes].
To investigate the effect of glucagon-like peptide 1 (GLP-1) on cognitive dysfunction in diabetic rats.. Male SD rats were randomly divided into normal control group, diabetes mellitus (DM) group, and GLP-1 treatment group. Rat models of type 2 diabetes were established by high-sugar and high-fat feeding and streptozotocin (STZ) injection, and 25 days after the onset of diabetes, GLP-1 was infused in GLP-1 treatment group at the rate of 30 pmol·kg. Compared with the normal control group, the diabetic rats showed significantly decreased learning and memory abilities (P<0.05) with increased hippocampal expressions of APP, BACE1, Arc, ERK1/2, PKA, and PKC mRNAs (P<0.05) and Arc protein. Compared with diabetic rats, GLP-1-treated rats showed significantly improvements in the learning and memory function (P<0.05) with decreased expressions of APP, BACE1, Arc, ERK1/2, and PKA mRNAs (P<0.05) and Arc protein.. GLP-1 can improve cognitive dysfunctions in diabetic rats possibly by regulating the PKC, PKA, and ERK1/2 pathways and inhibiting Arc expression in the hippocampus. Topics: Animals; Diabetes Mellitus, Experimental; Diabetes Mellitus, Type 2; Glucagon-Like Peptide 1; Hippocampus; Learning; Male; Memory; Rats; Rats, Sprague-Dawley; Real-Time Polymerase Chain Reaction; Streptozocin | 2016 |
Glucagon-like peptide-1 analogues and risk of breast cancer in women with type 2 diabetes: population based cohort study using the UK Clinical Practice Research Datalink.
To determine whether the use of glucagon-like peptide-1 (GLP-1) analogues, compared with the use of dipeptidylpeptidase-4 (DPP-4) inhibitors, is associated with an increased risk of incident breast cancer in patients with type 2 diabetes.. Population based cohort study.. Clinical Practice Research Datalink, UK.. 44 984 women aged at least 40 years, who were newly treated with glucose lowering drugs between 1 January 2007 and 31 March 2015, with follow-up until 31 March 2016.. Time varying use of GLP-1 analogues compared with use of DPP-4 inhibitors, with exposures lagged by one year for latency purposes. Time dependent Cox proportional hazards models were used to estimate adjusted hazard ratios with 95% confidence intervals of incident breast cancer associated with use of GLP-1 analogues overall, by cumulative duration of use, and time since initiation.. The cohort was followed for a mean of 3.5 years (standard deviation 2.2), with 549 incident events of breast cancer recorded (crude incidence 3.5 (95% confidence interval 3.3 to 3.8) per 1000 person years). Overall, compared with use of DPP-4 inhibitors, use of GLP-1 analogues was not associated with an increased risk of breast cancer (incidence 4.4 v 3.4 per 1000 person years; hazard ratio 1.40 (95% confidence interval 0.91 to 2.16)). Hazard ratios gradually increased with longer durations of use, with a peak between two to three years of GLP-1 use (2.66 (95% confidence interval 1.32 to 5.38)), and returned closer to the null after more than three years of use (0.98 (0.24 to 4.03)). A similar pattern was observed with time since initiation of GLP-1 analogues.. In this population based cohort study, use of GLP-1 analogues was not associated with an overall increased risk of breast cancer. Although it is not possible to rule out a tumour promoter effect, the observed duration-response associations are likely the result of a transient increase in detection of breast cancers in GLP-1 analogue users. Topics: Aged; Breast Neoplasms; Cohort Studies; Diabetes Mellitus, Type 2; Dipeptidyl-Peptidase IV Inhibitors; Female; Glucagon-Like Peptide 1; Humans; Hypoglycemic Agents; Middle Aged; Risk Factors; Time Factors; United Kingdom | 2016 |
Liraglutide and Cardiovascular Outcomes in Type 2 Diabetes.
Topics: Cardiovascular System; Diabetes Mellitus, Type 2; Glucagon-Like Peptide 1; Humans; Hypoglycemic Agents; Liraglutide; Treatment Outcome | 2016 |
Liraglutide and Cardiovascular Outcomes in Type 2 Diabetes.
Topics: Cardiovascular System; Diabetes Mellitus, Type 2; Glucagon-Like Peptide 1; Humans; Hypoglycemic Agents; Liraglutide; Treatment Outcome | 2016 |
Liraglutide and Cardiovascular Outcomes in Type 2 Diabetes.
Topics: Cardiovascular System; Diabetes Mellitus, Type 2; Glucagon-Like Peptide 1; Humans; Hypoglycemic Agents; Liraglutide; Treatment Outcome | 2016 |
Diabetes: Incretin mimetics and insulin - closing the gap to normoglycaemia.
Topics: Diabetes Mellitus, Type 2; Dipeptidyl-Peptidase IV Inhibitors; Glucagon-Like Peptide 1; Humans; Hypoglycemic Agents; Incretins; Insulin | 2016 |
GLP-1 ANALOGUES FOR THE TREATMENT OF TYPE 2 DIABETES IN LATINOS/HISPANICS.
Topics: Diabetes Mellitus, Type 2; Glucagon-Like Peptide 1; Hispanic or Latino; Humans; Hypoglycemic Agents | 2016 |
β-cell-mimetic designer cells provide closed-loop glycemic control.
Chronically deregulated blood-glucose concentrations in diabetes mellitus result from a loss of pancreatic insulin-producing β cells (type 1 diabetes, T1D) or from impaired insulin sensitivity of body cells and glucose-stimulated insulin release (type 2 diabetes, T2D). Here, we show that therapeutically applicable β-cell-mimetic designer cells can be established by minimal engineering of human cells. We achieved glucose responsiveness by a synthetic circuit that couples glycolysis-mediated calcium entry to an excitation-transcription system controlling therapeutic transgene expression. Implanted circuit-carrying cells corrected insulin deficiency and self-sufficiently abolished persistent hyperglycemia in T1D mice. Similarly, glucose-inducible glucagon-like peptide 1 transcription improved endogenous glucose-stimulated insulin release and glucose tolerance in T2D mice. These systems may enable a combination of diagnosis and treatment for diabetes mellitus therapy. Topics: Animals; Biomimetics; Blood Glucose; Calcium; Calcium Channels, L-Type; Cell Engineering; Diabetes Mellitus, Experimental; Diabetes Mellitus, Type 1; Diabetes Mellitus, Type 2; Glucagon-Like Peptide 1; HEK293 Cells; Humans; Hyperglycemia; Insulin; Insulin Secretion; Insulin-Secreting Cells; Transcription, Genetic; Transgenes | 2016 |
Lack of Benefit for Liraglutide in Heart Failure.
Topics: Diabetes Mellitus, Type 2; Glucagon-Like Peptide 1; Heart Failure; Humans; Hypoglycemic Agents; Liraglutide | 2016 |
Lack of Benefit for Liraglutide in Heart Failure-Reply.
Topics: Diabetes Mellitus, Type 2; Glucagon-Like Peptide 1; Heart Failure; Humans; Hypoglycemic Agents; Liraglutide | 2016 |
Glucagon-like Peptide 1 Receptor Signaling in Acinar Cells Causes Growth-Dependent Release of Pancreatic Enzymes.
Incretin-based therapies are widely used for type 2 diabetes and now also for obesity, but they are associated with elevated plasma levels of pancreatic enzymes and perhaps a modestly increased risk of acute pancreatitis. However, little is known about the effects of the incretin hormone glucagon-like peptide 1 (GLP-1) on the exocrine pancreas. Here, we identify GLP-1 receptors on pancreatic acini and analyze the impact of receptor activation in humans, rodents, isolated acini, and cell lines from the exocrine pancreas. GLP-1 did not directly stimulate amylase or lipase release. However, we saw that GLP-1 induces phosphorylation of the epidermal growth factor receptor and activation of Foxo1, resulting in cell growth with concomitant enzyme release. Our work uncovers GLP-1-induced signaling pathways in the exocrine pancreas and suggests that increases in amylase and lipase levels in subjects treated with GLP-1 receptor agonists reflect adaptive growth rather than early-stage pancreatitis. Topics: Acinar Cells; Amylases; Animals; Cell Line; Cell Proliferation; Diabetes Mellitus, Type 2; Forkhead Box Protein O1; Gene Expression Regulation, Enzymologic; Glucagon-Like Peptide 1; Glucagon-Like Peptide-1 Receptor; Humans; Incretins; Lipase; Pancreas; Pancreatitis; Signal Transduction | 2016 |
Blockade of Central GLP-1 Receptors Deteriorates the Improvement of Diabetes after Ileal Transposition.
Topics: Animals; Bariatric Surgery; Blood Glucose; Diabetes Mellitus, Experimental; Diabetes Mellitus, Type 2; Eating; Glucagon-Like Peptide 1; Glucagon-Like Peptide-1 Receptor; Ileum; Male; Random Allocation; Rats | 2016 |
Conformational Analysis of the Host-Defense Peptides Pseudhymenochirin-1Pb and -2Pa and Design of Analogues with Insulin-Releasing Activities and Reduced Toxicities.
Pseudhymenochirin-1Pb (Ps-1Pb; IKIPSFFRNILKKVGKEAVSLIAGALKQS) and pseudhymenochirin-2Pa (Ps-2Pa; GIFPIFAKLLGKVIKVASSLISKGRTE) are amphibian peptides with broad spectrum antimicrobial activities and cytotoxicity against mammalian cells. In the membrane-mimetic solvent 50% (v/v) trifluoroethanol-H2O, both peptides adopt a well-defined α-helical conformation that extends over almost all the sequence and incorporates a flexible bend. Both peptides significantly (p < 0.05) stimulate the rate of release of insulin from BRIN-BD11 clonal β-cells at concentrations ≥ 0.1 nM but produce loss of integrity of the plasma membrane at concentrations ≥ 1 μM. Increasing cationicity by the substitution Glu(17) → l-Lys in Ps-1Pb and Glu(27) → l-Lys in Ps-2Pa generates analogues with increased cytotoxicity and reduced insulin-releasing potency. In contrast, the analogues [R8r]Ps-1Pb and [K8k,K19k]Ps-2Pa, incorporating d-amino acid residues to destabilize the α-helical domains, retain potent insulin-releasing activity but are nontoxic to BRIN-BD11 cells at concentrations of 3 μM. [R8r]Ps-1Pb produces a significant increase in insulin release rate at 0.3 nM and [K8k,K19k]Ps-2Pa at 0.01 nM. Both analogues show low hemolytic activity (IC50 > 100 μM) but retain broad-spectrum antimicrobial activity and remain cytotoxic to a range of human tumor cell lines, albeit with lower potency than the naturally occurring peptides. These analogues show potential for development into agents for type 2 diabetes therapy. Topics: Amino Acid Sequence; Amphibian Proteins; Animals; Antimicrobial Cationic Peptides; Cell Line, Tumor; Diabetes Mellitus, Type 2; Humans; Insulin; Insulin Secretion; Microbial Sensitivity Tests; Molecular Structure; Nuclear Magnetic Resonance, Biomolecular | 2015 |
Preoperative use of incretins is associated with increased diabetes remission after RYGB surgery among patients taking insulin: a retrospective cohort analysis.
The main goal of this study was to determine the effects of incretins on type 2 diabetes (T2D) remission after Roux-en-Y gastric bypass (RYGB) surgery for patients taking insulin.. Type 2 diabetes is a chronic disease with potentially debilitating consequences. RYGB surgery is one of the few interventions that can remit T2D. Preoperative use of insulin, however, predisposes to significantly lower T2D remission rates.. A retrospective cohort of 690 T2D patients with at least 12 months follow-up and available electronic medical records was used to identify 37 T2D patients who were actively using a Glucagon-like peptide 1 (GLP-1) agonist in addition to another antidiabetic medication, during the preoperative period.. Here, we report that use of insulin, along with other antidiabetic medications, significantly diminished overall T2D remission rates 14 months after RYGB surgery (9%) compared with patients not taking insulin (56%). Addition of the GLP-1 agonist, however, increased significantly T2D early remission rates (22%), compared with patients not taking the GLP-1 agonist (4%). Moreover, the 6-year remission rates were also significantly higher for the former group of patients. The GLP-1 agonist did not improve the remission rates of diabetic patients not taking insulin as part of their pharmacotherapy.. Preoperative use of antidiabetic medication, coupled with an incretin agonist, could significantly improve the odds of T2D remission after RYGB surgery in patients also using insulin. Topics: Diabetes Mellitus, Type 2; Gastric Bypass; Glucagon-Like Peptide 1; Humans; Hypoglycemic Agents; Incretins; Insulin; Preoperative Period; Remission Induction; Retrospective Studies | 2015 |
Effects of selected antidiabetics on weight loss--a retrospective database analysis.
In published studies metformin was often associated with weight loss in type 2 diabetes patients. Until now, no epidemiological studies have directly compared the effects of DPP-4 and GLP-1 versus metformin on weight loss. Our study is a comparison of sulfonylurea, DPP-4 and GLP-1 with metformin regarding body weight in type 2 diabetes patients.. Data from 2641 patients initiated therapy with either metformin, sulfonylurea, DPP-inhibitors or GLP-1 with baseline BMI >30 were retrospectively analyzed (Disease Analyzer Germany: 11/2008-10/2012). Comparison was performed for the weight change after 1 year of therapy compared with the last value prior to therapy. Differences between SU, DPP-4, GLP-1 versus metformin were estimated using regression model adjusted for age, gender, health insurance status, defined co-diagnoses and body weight at baseline.. In absolute values, metformin patients lost an average of 2.6 kg, subjects treated with SU gained 0.3 kg, body weight in the DPP-4 group decreased by 1.8 kg and GLP-1 patients lost 3.3 kg in body weight after 1 year. After adjustment for other variables, comparisons with metformin revealed the following results: SU +3.4 kg (p < 0.001), DPP-4 +1.0 kg (p = 0.003) and GLP-1 -0.4 kg (p = 0.589).. Our study showed that GLP-1 treatment was comparable to metformin regarding the weight reduction, while sulfonylurea and DPP-4 are inferior in this regard. Topics: Aged; Databases, Factual; Diabetes Mellitus, Type 2; Dipeptidyl-Peptidase IV Inhibitors; Female; Glucagon-Like Peptide 1; Humans; Hypoglycemic Agents; Male; Middle Aged; Retrospective Studies; Sulfonylurea Compounds; Time Factors; Treatment Outcome; Weight Loss | 2015 |
Relationship between glycemic control and gastric emptying in poorly controlled type 2 diabetes.
Acute hyperglycemia delays gastric emptying in patients with diabetes. However, it is not clear whether improved control of glycemia affects gastric emptying in these patients. We investigated whether overnight and short-term (6 mo) improvements in control of glycemia affect gastric emptying.. We studied 30 patients with poorly controlled type 2 diabetes (level of glycosylated hemoglobin, >9%). We measured gastric emptying using the [(13)C]-Spirulina platensis breath test on the patients' first visit (visit 1), after overnight administration of insulin or saline, 1 week later (visit 2), and 6 months after intensive therapy for diabetes. We also measured fasting and postprandial plasma levels of C-peptide, glucagon-like peptide 1, and amylin, as well as autonomic functions.. At visit 1, gastric emptying was normal in 10 patients, delayed in 14, and accelerated in 6; 6 patients had gastrointestinal symptoms; vagal dysfunction was associated with delayed gastric emptying (P < .05). Higher fasting blood levels of glucose were associated with shorter half-times of gastric emptying (thalf) at visits 1 (r = -0.46; P = .01) and 2 (r = -0.43; P = .02). Although blood levels of glucose were lower after administration of insulin (132 ± 7 mg/dL) than saline (211 ± 15 mg/dL; P = .0002), gastric emptying thalf was not lower after administration of insulin, compared with saline. After 6 months of intensive therapy, levels of glycosylated hemoglobin decreased from 10.6% ± 0.3% to 9% ± 0.4% (P = .0003), but gastric emptying thalf did not change (92 ± 8 min before, 92 ± 7 min after). Gastric emptying did not correlate with plasma levels of glucagon-like peptide 1 and amylin.. Two-thirds of patients with poorly controlled type 2 diabetes have mostly asymptomatic yet abnormal gastric emptying. Higher fasting blood levels of glucose are associated with faster gastric emptying. Overnight and sustained (6 mo) improvements in glycemic control do not affect gastric emptying. Topics: Blood Glucose; Breath Tests; C-Peptide; Diabetes Mellitus, Type 2; Female; Gastric Emptying; Glucagon-Like Peptide 1; Humans; Islet Amyloid Polypeptide; Male; Middle Aged | 2015 |
Role of rs6923761 gene variant in glucagon-like peptide 1 receptor in basal GLP-1 levels, cardiovascular risk factor and serum adipokine levels in naïve type 2 diabetic patients.
Role of GLP-1 variants on basal GLP-1 levels, body weight and cardiovascular risk factors remains unclear in patients with diabetes mellitus type 2.. Our aim was to analyze the effects of rs6923761 GLP-1 receptor polymorphism on body weight, cardiovascular risk factors, basal GLP-1 levels and serum adipokine levels in naïve patients with diabetes mellitus type 2.. A sample of 104 naïve patients with diabetes mellitus type 2 was enrolled in a prospective way. Basal fasting glucose, c-reactive protein (CRP), insulin, insulin resistance (HOMA), total cholesterol, LDL-cholesterol, HDL-cholesterol, triglycerides concentration, basal GLP-1, HbA1c and adipokines (leptin, adiponectin, resistin) levels were determined. Weights, body mass index, waist circumference, fat mass by bioimpedance and blood pressure measures were measured.. Forty-nine patients (47.1%) had the genotype GG and 55 (52.9%) diabetic subjects had the next genotypes; GA (44 patients, 42.3%) or AA (11 study subjects, 10.6%) (second group). In A allele carriers, basal GLP-1 levels were higher than non-carriers (2.9 ± 2.1 ng/ml; p < 0.05). No differences were detected between both genotype groups.. Our cross-sectional study revealed an association between the rs6923761 GLP-1 receptor polymorphism (A allele carriers) and basal GLP-1 levels in naïve patients with diabetes mellitus type 2. Topics: Adipokines; Adult; Aged; Cardiovascular Diseases; Cross-Sectional Studies; Diabetes Mellitus, Type 2; Female; Genetic Variation; Glucagon-Like Peptide 1; Glucagon-Like Peptide-1 Receptor; Humans; Male; Middle Aged; Prospective Studies; Risk Factors | 2015 |
Incretin-based drugs and the risk of congestive heart failure.
To determine whether the use of incretin-based drugs, including GLP-1 analogs and dipeptidyl peptidase-4 inhibitors, is associated with an increased risk of congestive heart failure (CHF) among patients with type 2 diabetes.. The U.K. Clinical Practice Research Datalink, linked to the Hospital Episode Statistics database, was used to conduct a cohort study with a nested case-control analysis among patients newly prescribed antidiabetic drugs between 1 January 2007 and 31 March 2012 and no prior history of CHF. Case subjects were defined as patients hospitalized for a first CHF and matched with up to 20 control subjects on age, duration of treated diabetes, calendar year, and time since cohort entry. Conditional logistic regression was used to estimate odds ratios (ORs) with corresponding 95% CIs of incident CHF comparing current use of incretin-based drugs with current use of two or more oral antidiabetic drugs.. The cohort consisted of 57,737 patients followed for a mean 2.4 years, during which time 1,118 incident cases of hospitalized CHF were identified (incidence rate 8.1/1,000 person-years). Current use of incretin-based drugs was not associated with an increased risk of CHF (adjusted OR 0.85 [95% CI 0.62-1.16]). Secondary analyses revealed no duration-response relationship (P trend = 0.39).. In our population-based study, incretin-based drug use was not associated with an increased risk of CHF among patients with type 2 diabetes. These findings provide some reassurance, but will need to be replicated in other large-scale studies. Topics: Aged; Diabetes Mellitus, Type 2; Diabetic Cardiomyopathies; Dipeptidyl-Peptidase IV Inhibitors; Epidemiologic Methods; Female; Glucagon-Like Peptide 1; Heart Failure; Humans; Hypoglycemic Agents; Incretins; Male; Middle Aged | 2015 |
Teneligliptin improves glycemic control with the reduction of postprandial insulin requirement in Japanese diabetic patients.
Teneligliptin is a novel peptidomimetic-chemotype prolylthiazolidine-based inhibitor of dipeptidyl peptidase-4 (DPP-4). The aim of this study was to evaluate the effects of teneligliptin on 24 h blood glucose control and gastrointestinal hormone responses to a meal tolerance test, and to investigate the glucose-lowering mechanisms of teneligliptin. Ten patients with type 2 diabetes mellitus (T2DM) were treated for 3 days with teneligliptin (20 mg/day). Postprandial profiles for glucose, insulin, glucagon, active glucagon-like peptide-1 (GLP-1), active glucose-dependent insulinotropic polypeptide (GIP), ghrelin, des-acyl ghrelin, and 24 h glycemic fluctuations were measured via continuous glucose monitoring for 4 days. Once daily teneligliptin administration for 3 days significantly lowered postprandial and fasting glucose levels. Significant elevations of fasting and postprandial active GLP-1 and postprandial active GIP levels were observed. Teneligliptin lowered postprandial glucose elevations, 24 h mean blood glucose levels, standard deviation of 24 h glucose levels and mean amplitude of glycemic excursions (MAGE) without hypoglycemia. Serum insulin levels in the fasting state and 30 min after a meal were similar before and after teneligliptin treatment; however significant reductions at 60 to 180 min after treatment were observed. A significant elevation in early-phase insulin secretion estimated by insulinogenic and oral disposition indices, and a significant reduction in postprandial glucagon AUC were observed. Both plasma ghrelin and des-acyl ghrelin levels were unaltered following teneligliptin treatment. Teneligliptin improved 24 h blood glucose levels by increasing active incretin levels and early-phase insulin secretion, reducing the postprandial insulin requirement, and reducing glucagon secretion. Even short-term teneligliptin treatment may offer benefits for patients with T2DM. Topics: Aged; Blood Glucose; Combined Modality Therapy; Diabetes Mellitus, Type 2; Dipeptidyl-Peptidase IV Inhibitors; Drug Therapy, Combination; Female; Gastric Inhibitory Polypeptide; Glucagon; Glucagon-Like Peptide 1; Humans; Hyperglycemia; Hypoglycemia; Hypoglycemic Agents; Insulin; Insulin Resistance; Japan; Middle Aged; Monitoring, Ambulatory; Postprandial Period; Pyrazoles; Thiazolidines | 2015 |
Positive effects of GLP-1 receptor activation with liraglutide on pancreatic islet morphology and metabolic control in C57BL/KsJ db/db mice with degenerative diabetes.
Stable glucagon-like peptide-1 (GLP-1) mimetics, such as the GLP-1 analogue liraglutide, are approved for treatment of type 2 diabetes. GLP-1 has a spectrum of anti-diabetic effects that are of possible utility in the treatment of more severe forms of diabetes.. The present study has evaluated the effect of once daily liraglutide injection (25 nmol/kg bw) for 15 days on metabolic control, islet architecture, and islet morphology in C57BL/KsJ db/db mice.. Liraglutide had no appreciable effects on body weight, food intake, and non-fasting glucose and insulin concentrations. However, HbA1c was significantly (p < 0.001) decreased, and oral glucose tolerance improved in liraglutide treated db/db mice. Pancreatic insulin content was increased (p < 0.05) compared with saline controls, and the ratio of pancreatic insulin to glucagon in liraglutide mice was similar to lean mice. Although liraglutide did not alter islet number or area, the proportion of beta cells per islet was significantly increased (p < 0.05) and alpha cells decreased (p < 0.05), with normalization of islet architecture. In harmony with this, cell proliferation was significantly (p < 0.001) augmented and apoptosis reduced (p < 0.001) in liraglutide treated mice. Expression of pancreatic islet glucose-dependent insulinotropic polypeptide immunoreactivity was observed in lean control and, particularly, liraglutide treated db/db mice, whereas control db/db mice exhibited little glucose-dependent insulinotropic polypeptide staining.. These data reveal that stable GLP-1 analogues exert important beneficial effects on pancreatic islet architecture and beta-cell turnover, indicating that they may be useful in the treatment of severe forms of diabetes with islet degeneration. Topics: Animals; Apoptosis; Blood Glucose; Body Weight; Cell Proliferation; Diabetes Mellitus, Experimental; Diabetes Mellitus, Type 2; Glucagon-Like Peptide 1; Glucagon-Like Peptide-1 Receptor; Glycated Hemoglobin; Hypoglycemic Agents; Islets of Langerhans; Liraglutide; Male; Mice; Mice, Inbred C57BL; Radioimmunoassay | 2015 |
Saxagliptin restores vascular mitochondrial exercise response in the Goto-Kakizaki rat.
Cardiovascular disease risk and all-cause mortality are largely predicted by physical fitness. Exercise stimulates vascular mitochondrial biogenesis through endothelial nitric oxide synthase (eNOS), sirtuins, and PPARγ coactivator 1α (PGC-1α), a response absent in diabetes and hypertension. We hypothesized that an agent regulating eNOS in the context of diabetes could reconstitute exercise-mediated signaling to mitochondrial biogenesis. Glucagon-like peptide 1 (GLP-1) stimulates eNOS and blood flow; we used saxagliptin, an inhibitor of GLP-1 degradation, to test whether vascular mitochondrial adaptation to exercise in diabetes could be restored. Goto-Kakizaki (GK) rats, a nonobese, type 2 diabetes model, and Wistar controls were exposed to an 8-day exercise intervention with or without saxagliptin (10 mg·kg·d). We evaluated the impact of exercise and saxagliptin on mitochondrial proteins and signaling pathways in aorta. Mitochondrial protein expression increased with exercise in the Wistar aorta and decreased or remained unchanged in the GK animals. GK rats treated with saxagliptin plus exercise showed increased expression of mitochondrial complexes, cytochrome c, eNOS, nNOS, PGC-1α, and UCP3 proteins. Notably, a 3-week saxagliptin plus exercise intervention significantly increased running time in the GK rats. These data suggest that saxagliptin restores vascular mitochondrial adaptation to exercise in a diabetic rodent model and may augment the impact of exercise on the vasculature. Topics: Adamantane; Animals; Diabetes Mellitus, Type 2; Dipeptides; Dipeptidyl-Peptidase IV Inhibitors; Disease Models, Animal; Glucagon-Like Peptide 1; Mitochondria, Muscle; Mitochondrial Proteins; Motor Activity; Muscle, Smooth, Vascular; Nitric Oxide Synthase Type III; Organelle Biogenesis; Physical Conditioning, Animal; Rats; Treatment Outcome | 2015 |
Is insulin the most effective injectable antihyperglycaemic therapy?
The recent type 2 diabetes American Diabetes Association/European Association for the Study of Diabetes (ADA/EASD) position statement suggested insulin is the most effective glucose-lowering therapy, especially when glycated haemoglobin (HbA1c) is very high. However, randomized studies comparing glucagon-like peptide-1 receptor agonists (GLP-1RAs) exenatide once-weekly [OW; DURATION-3 (Diabetes therapy Utilization: Researching changes in A1c, weight, and other factors Through Intervention with exenatide ONce-Weekly)] and liraglutide once-daily [OD; LEAD-5 (Liraglutide Effect and Action in Diabetes)] with insulin glargine documented greater HbA1c reduction with GLP-1RAs, from baseline HbA1c ∼8.3% (67 mmol/mol). This post hoc analysis of DURATION-3 and LEAD-5 examined changes in HbA1c, fasting glucose and weight with exenatide OW or liraglutide and glargine, by baseline HbA1c quartile.. Descriptive statistics were provided for change in HbA1c, fasting glucose, weight, and insulin dose, and subjects (%) achieving HbA1c <7.0%, by baseline HbA1c quartile. Inferential statistical analysis on the effect of baseline HbA1c quartile was performed for change in HbA1c. An analysis of covariance (ANCOVA) model was used to evaluate similarity in change in HbA1c across HbA1c quartiles.. At 26 weeks, in both studies, HbA1c reduction, and proportion of subjects reaching HbA1c <7.0%, were similar or numerically greater with the GLP-1RAs than glargine for all baseline HbA1c quartiles. Fasting glucose reduction was similar or numerically greater with glargine. Weight decreased with both GLP-1RAs across all quartiles; subjects taking glargine gained weight, more at higher baseline HbA1c. Adverse events were uncommon although gastrointestinal events occurred more frequently with GLP-1RAs.. HbA1c reduction with the GLP-1RAs appears at least equivalent to that with basal insulin, irrespective of baseline HbA1c. This suggests that liraglutide and exenatide OW may be appropriate alternatives to basal insulin in type 2 diabetes, including when baseline HbA1c is very high (≥9.0%). Topics: Blood Glucose; Body Weight; Diabetes Mellitus, Type 2; Exenatide; Fasting; Female; Glucagon-Like Peptide 1; Glycated Hemoglobin; Humans; Hypoglycemic Agents; Insulin Glargine; Insulin, Long-Acting; Liraglutide; Male; Metformin; Middle Aged; Peptides; Treatment Outcome; Venoms | 2015 |
Short- and long-term hormonal and metabolic consequences of reversing gastric bypass to normal anatomy in a type 2 diabetes patient.
Gastric bypass (GBP) results in rapid type 2 diabetes (T2D) remission in most cases. Consequences of GBP reversal are unknown. A GBP-operated T2D patient was given mixed-meal tests before (MMTpre), 2 months (MMT2-M) and 12 months (MMT12-M) after GBP reversal. Glucose, hormones and metabolite profiles were assessed. MMT2-M displayed slightly lower glucose levels; MMT12-M displayed higher glucose and insulin levels, indicating deteriorating glycaemia. Homeostasis model assessment (HOMA)-β was higher at MMT2-M, but reduced at MMT12-M. Matsuda index revealed slightly reduced insulin sensitivity at MMT2-M, which deteriorated further at MMT12-M. Markers for metabolic stress and insulin resistance were elevated at MMT12-M. Gastric inhibitory polypeptide (GIP) levels were increased at MMT2-M and decreased at MMT12-M. Glucagon-like peptide-1 (GLP-1) decreased at MMT2-M and further decreased at MMT12-M. In conclusion, in this patient, GBP reversal provoked deteriorating glycaemia and long-term development of insulin resistance. Topics: Anastomosis, Surgical; Blood Glucose; Diabetes Mellitus, Type 2; Follow-Up Studies; Gastric Bypass; Gastric Inhibitory Polypeptide; Glucagon-Like Peptide 1; Humans; Insulin; Insulin Resistance; Male; Meals; Middle Aged; Time Factors | 2015 |
Partial blockade of Kv2.1 channel potentiates GLP-1's insulinotropic effects in islets and reduces its dose required for improving glucose tolerance in type 2 diabetic male mice.
Glucagon-like peptide-1 (GLP-1)-based medicines have recently been widely used to treat type 2 diabetic patients, whereas adverse effects of nausea and vomiting have been documented. Inhibition of voltage-gated K(+) channel subtype Kv2.1 in pancreatic β-cells has been suggested to contribute to mild depolarization and promotion of insulin release. This study aimed to determine whether the blockade of Kv2.1 channels potentiates the insulinotropic effect of GLP-1 agonists. Kv2.1 channel blocker guangxitoxin-1E (GxTx) and GLP-1 agonist exendin-4 at subthreshold concentrations, when combined, markedly increased the insulin release and cytosolic Ca(2+) concentration ([Ca(2+)]i) in a glucose-dependent manner in mouse islets and β-cells. Exendin-4 at subthreshold concentration alone increased islet insulin release and β-cell [Ca(2+)]i in Kv2.1(+/-) mice. The [Ca(2+)]i response to subthreshold exendin-4 and GxTx in combination was attenuated by pretreatment with protein kinase A inhibitor H-89, indicating the protein kinase A dependency of the cooperative effect. Furthermore, subthreshold doses of GxTx and GLP-1 agonist liraglutide in combination markedly increased plasma insulin and improved glucose tolerance in diabetic db/db mice and NSY mice. These results demonstrate that a modest suppression of Kv2.1 channels dramatically raises insulinotropic potency of GLP-1-based drugs, which opens a new avenue to reduce their doses and associated adverse effects while achieving the same glycemic control in type 2 diabetes. Topics: Animals; Arthropod Proteins; Cells, Cultured; Diabetes Mellitus, Type 2; Exenatide; Glucagon-Like Peptide 1; Glucose Intolerance; Glucose Tolerance Test; Insulin; Islets of Langerhans; Male; Mice; Mice, Inbred C57BL; Mice, Inbred NOD; Mice, Knockout; Peptides; Shab Potassium Channels; Spider Venoms; Venoms | 2015 |
Selective disruption of Tcf7l2 in the pancreatic β cell impairs secretory function and lowers β cell mass.
Type 2 diabetes (T2D) is characterized by β cell dysfunction and loss. Single nucleotide polymorphisms in the T-cell factor 7-like 2 (TCF7L2) gene, associated with T2D by genome-wide association studies, lead to impaired β cell function. While deletion of the homologous murine Tcf7l2 gene throughout the developing pancreas leads to impaired glucose tolerance, deletion in the β cell in adult mice reportedly has more modest effects. To inactivate Tcf7l2 highly selectively in β cells from the earliest expression of the Ins1 gene (∼E11.5) we have therefore used a Cre recombinase introduced at the Ins1 locus. Tcfl2(fl/fl)::Ins1Cre mice display impaired oral and intraperitoneal glucose tolerance by 8 and 16 weeks, respectively, and defective responses to the GLP-1 analogue liraglutide at 8 weeks. Tcfl2(fl/fl)::Ins1Cre islets displayed defective glucose- and GLP-1-stimulated insulin secretion and the expression of both the Ins2 (∼20%) and Glp1r (∼40%) genes were significantly reduced. Glucose- and GLP-1-induced intracellular free Ca(2+) increases, and connectivity between individual β cells, were both lowered by Tcf7l2 deletion in islets from mice maintained on a high (60%) fat diet. Finally, analysis by optical projection tomography revealed ∼30% decrease in β cell mass in pancreata from Tcfl2(fl/fl)::Ins1Cre mice. These data demonstrate that Tcf7l2 plays a cell autonomous role in the control of β cell function and mass, serving as an important regulator of gene expression and islet cell coordination. The possible relevance of these findings for the action of TCF7L2 polymorphisms associated with Type 2 diabetes in man is discussed. Topics: Animals; Blood Glucose; Diabetes Mellitus, Type 2; Diet, High-Fat; Disease Models, Animal; Gene Deletion; Genetic Loci; Genome-Wide Association Study; Glucagon; Glucagon-Like Peptide 1; Glucagon-Like Peptide-1 Receptor; Insulin; Insulin Secretion; Insulin-Secreting Cells; Integrases; Mice; Mice, Inbred C57BL; Mice, Knockout; Molecular Weight; Pancreas; Polymorphism, Single Nucleotide; Receptors, Glucagon; Transcription Factor 7-Like 2 Protein; Wnt Signaling Pathway | 2015 |
Global biochemical profiling identifies β-hydroxypyruvate as a potential mediator of type 2 diabetes in mice and humans.
Glucose-dependent insulinotropic polypeptide (GIP) and GLP-1 are incretins secreted by respective K and L enteroendocrine cells after eating and amplify glucose-stimulated insulin secretion (GSIS). This amplification has been termed the "incretin response." To determine the role(s) of K cells for the incretin response and type 2 diabetes mellitus (T2DM), diphtheria toxin-expressing (DT) mice that specifically lack GIP-producing cells were backcrossed five to eight times onto the diabetogenic NONcNZO10/Ltj background. As in humans with T2DM, DT mice lacked an incretin response, although GLP-1 release was maintained. With high-fat (HF) feeding, DT mice remained lean but developed T2DM, whereas wild-type mice developed obesity but not diabetes. Metabolomics identified biochemicals reflecting impaired glucose handling, insulin resistance, and diabetes complications in prediabetic DT/HF mice. β-Hydroxypyruvate and benzoate levels were increased and decreased, respectively, suggesting β-hydroxypyruvate production from d-serine. In vitro, β-hydroxypyruvate altered excitatory properties of myenteric neurons and reduced islet insulin content but not GSIS. β-Hydroxypyruvate-to-d-serine ratios were lower in humans with impaired glucose tolerance compared with normal glucose tolerance and T2DM. Earlier human studies unmasked a neural relay that amplifies GIP-mediated insulin secretion in a pattern reciprocal to β-hydroxypyruvate-to-d-serine ratios in all groups. Thus, K cells may maintain long-term function of neurons and β-cells by regulating β-hydroxypyruvate levels. Topics: Animals; Blood Glucose; Diabetes Mellitus, Type 2; Enteroendocrine Cells; Female; Gastric Inhibitory Polypeptide; Glucagon-Like Peptide 1; Humans; Insulin-Secreting Cells; Male; Metabolomics; Mice; Mice, Transgenic; Pyruvates | 2015 |
Effects of acute exercise on pancreatic endocrine function in subjects with type 2 diabetes.
We determined the effects of exercise on pancreatic endocrine responses to metabolic stimuli in subjects with type 2 diabetes (T2D) and examined the influence of subjects' diabetic status. Fourteen subjects underwent a hyperglycaemic clamp with glucagon-like peptide-1 (GLP-1) infusion and arginine injection, the morning after a 1-h walk or no exercise. Subjects were stratified by high and low fasting plasma glucose (FPG) levels and by glycated haemoglobin (HbA1c) levels, as well as by current use/non-use of antidiabetic medication. In the entire cohort, exercise did not alter insulin secretion, while glucagon levels were increased in all clamp phases (p < 0.05 to <0.01). In subjects with low FPG levels, exercise increased GLP-1-stimulated insulin secretion (p < 0.05), with the same trend being observed for arginine (p = 0.08). The same trends were seen for subjects with low HbA1c levels. Furthermore, exercise increased GLP-1- and arginine-stimulated insulin secretion (p < 0.05) in subjects who were antidiabetic drug-naïve. Exercise-induced increases in insulin secretion are blunted in subjects with T2D with high rates of hyperglycaemia and in those using antidiabetic drugs. Topics: Arginine; Blood Glucose; Diabetes Mellitus, Type 2; Exercise; Fasting; Female; Glucagon; Glucagon-Like Peptide 1; Glucose Clamp Technique; Humans; Hyperglycemia; Infusions, Intravenous; Injections; Insulin; Insulin Secretion; Male; Pancreas; Treatment Outcome | 2015 |
Association of antidiabetic medications targeting the glucagon-like peptide 1 pathway and heart failure events in patients with diabetes.
Glucagon-like peptide-1 (GLP-1) agonists and dipeptidyl peptidase 4 (DPP-4) inhibitors (GLP-1 agents) may be protective in heart failure (HF). We set out to determine whether GLP-1 agent use is associated with HF risk in diabetics.. In this retrospective cohort study of members of a large health system, we identified >19,000 adult diabetics from January 1, 2000, to July 1, 2012. GLP-1 agent users were matched 1:2 to control subjects with the use of propensity matching based on age, race, sex, coronary disease, HF, diabetes duration, and number of antidiabetic medications. The association of GLP-1 agents with time to HF hospitalization was tested with multivariable Cox regression. All-cause hospitalization and mortality were secondary end points. We identified 1,426 users of GLP-1 agents and 2,798 control subjects. Both were similar except for angiotensin-converting enzyme inhibitors/angiotensin receptor blocker use, number of antidiabetic medications, and age. There were 199 hospitalizations, of which 128 were for HF, and 114 deaths. GLP-1 agents were associated with reduced risk of HF hospitalization (adjusted hazard ratio [aHR] 0.51, 95% confidence interval [CI] 0.34-0.77; P = .002), all-cause hospitalization (aHR 0.54, 95% CI 0.38-0.74; P = .001), and death (aHR 0.31, 95% CI 0.18-0.53; P = .001).. GLP-1 agents may reduce the risk of HF events in diabetics. Topics: Aged; Cohort Studies; Diabetes Mellitus, Type 2; Dipeptidyl-Peptidase IV Inhibitors; Drug Delivery Systems; Female; Glucagon-Like Peptide 1; Heart Failure; Hospitalization; Humans; Hypoglycemic Agents; Male; Middle Aged; Retrospective Studies | 2015 |
Liraglutide treatment in a patient with HIV, type 2 diabetes and sleep apnoea-hypopnoea syndrome.
Topics: Diabetes Mellitus, Type 2; Glucagon-Like Peptide 1; HIV Infections; Humans; Hypoglycemic Agents; Liraglutide; Male; Middle Aged; Obesity; Sleep Apnea, Obstructive; Weight Loss | 2015 |
Protective effects of pioglitazone and/or liraglutide on pancreatic β-cells in db/db mice: Comparison of their effects between in an early and advanced stage of diabetes.
The aim was to compare the protective effects of pioglitazone (PIO) and/or liraglutide (LIRA) on β-cells with the progression of diabetes. Male db/db mice were treated with PIO and/or LIRA for 2 weeks in an early and advanced stage. In an early stage insulin biosynthesis and secretion were markedly increased by PIO and LIRA which was not observed in an advanced stage. In concomitant with such phenomena, expression levels of various β-cell-related factors were up-regulated by PIO and LIRA only in an early stage. Furthermore, β-cell mass was also increased by the treatment only in an early stage. Although there was no difference in apoptosis ratio between the two stages, β-cell proliferation was augmented by the treatment only in an early stage. In conclusion, protective effects of pioglitazone and/or liraglutide on β-cells were more powerful in an early stage of diabetes compared to an advanced stage. Topics: Animals; Apoptosis; Blood Glucose; Caspases; Cell Proliferation; Diabetes Mellitus, Type 2; Disease Models, Animal; Disease Progression; Gene Expression; Glucagon; Glucagon-Like Peptide 1; Hypoglycemic Agents; Insulin; Insulin-Secreting Cells; Ki-67 Antigen; Liraglutide; Male; Mice; Mice, Transgenic; Organ Size; Pioglitazone; Proto-Oncogene Proteins c-bcl-2; RNA, Ribosomal, 18S; Thiazolidinediones; Time Factors; Triglycerides | 2015 |
A rationally designed monomeric peptide triagonist corrects obesity and diabetes in rodents.
We report the discovery of a new monomeric peptide that reduces body weight and diabetic complications in rodent models of obesity by acting as an agonist at three key metabolically-related peptide hormone receptors: glucagon-like peptide-1 (GLP-1), glucose-dependent insulinotropic polypeptide (GIP) and glucagon receptors. This triple agonist demonstrates supraphysiological potency and equally aligned constituent activities at each receptor, all without cross-reactivity at other related receptors. Such balanced unimolecular triple agonism proved superior to any existing dual coagonists and best-in-class monoagonists to reduce body weight, enhance glycemic control and reverse hepatic steatosis in relevant rodent models. Various loss-of-function models, including genetic knockout, pharmacological blockade and selective chemical knockout, confirmed contributions of each constituent activity in vivo. We demonstrate that these individual constituent activities harmonize to govern the overall metabolic efficacy, which predominantly results from synergistic glucagon action to increase energy expenditure, GLP-1 action to reduce caloric intake and improve glucose control, and GIP action to potentiate the incretin effect and buffer against the diabetogenic effect of inherent glucagon activity. These preclinical studies suggest that, so far, this unimolecular, polypharmaceutical strategy has potential to be the most effective pharmacological approach to reversing obesity and related metabolic disorders. Topics: Animals; Blood Glucose; Body Weight; Diabetes Complications; Diabetes Mellitus, Type 2; Glucagon-Like Peptide 1; HEK293 Cells; Humans; Insulin; Mice; Obesity; Peptides; Rats; Receptors, Gastrointestinal Hormone; Receptors, Glucagon; Rodentia | 2015 |
(7) Approaches to glycemic treatment.
Topics: Blood Glucose; Diabetes Mellitus, Type 1; Diabetes Mellitus, Type 2; Dipeptidyl-Peptidase IV Inhibitors; Glucagon-Like Peptide 1; Glycated Hemoglobin; Humans; Hypoglycemic Agents; Insulin; Insulin Infusion Systems; Metformin; Sodium-Glucose Transport Proteins; Sulfonylurea Compounds | 2015 |
Effect of bariatric surgery combined with medical therapy versus intensive medical therapy or calorie restriction and weight loss on glycemic control in Zucker diabetic fatty rats.
Bariatric surgery rapidly improves Type 2 diabetes mellitus (T2DM). Our objective was to profile and compare the extent and duration of improved glycemic control following Roux-en-Y gastric (RYGB) bypass surgery and vertical sleeve gastrectomy (SG) and compare against calorie restriction/weight loss and medical combination therapy-based approaches using the Zucker diabetic fatty rat (ZDF) rodent model of advanced T2DM. Male ZDF rats underwent RYGB (n = 15) or SG surgery (n = 10) at 18 wk of age and received postsurgical insulin treatment, as required to maintain mid-light-phase glycemia within a predefined range (10-15 mmol/l). In parallel, other groups of animals underwent sham surgery with ad libitum feeding (n = 6), with body weight (n = 8), or glycemic matching (n = 8) to the RYGB group, using food restriction or a combination of insulin, metformin, and liraglutide, respectively. Both bariatric procedures decreased the daily insulin dose required to maintain mid-light-phase blood glucose levels below 15 mmol/l, compared with those required by body weight or glycemia-matched rats (P < 0.001). No difference was noted between RYGB and SG with regard to initial efficacy. SG was, however, associated with higher food intake, weight regain, and higher insulin requirements vs. RYGB at study end (P < 0.05). Severe hypoglycemia occurred in several rats after RYGB. RYGB and SG significantly improved glycemic control in a rodent model of advanced T2DM. While short-term outcomes are similar, long-term efficacy appears marginally better after RYGB, although this is tempered by the increased risk of hypoglycemia. Topics: Age Factors; Animals; Behavior, Animal; Biomarkers; Blood Glucose; Caloric Restriction; Combined Modality Therapy; Diabetes Mellitus, Type 2; Disease Models, Animal; Drug Therapy, Combination; Eating; Feeding Behavior; Gastrectomy; Gastric Bypass; Glucagon-Like Peptide 1; Hypoglycemia; Hypoglycemic Agents; Insulin; Liraglutide; Male; Metformin; Obesity; Rats, Zucker; Risk Factors; Time Factors; Weight Gain; Weight Loss | 2015 |
Association of low GLP-1 with oxidative stress is related to cardiac disease and outcome in patients with type 2 diabetes mellitus: a pilot study.
Oxidative stress (OS) contributes to cardiovascular damage in type 2 diabetes mellitus (T2DM). The peptide glucagon-like peptide-1 (GLP-1) inhibits OS and exerts cardiovascular protective actions. Our aim was to investigate whether cardiac remodeling (CR) and cardiovascular events (CVE) are associated with circulating GLP-1 and biomarkers of OS in T2DM patients. We also studied GLP-1 antioxidant effects in a model of cardiomyocyte lipotoxicity. We examined 72 T2DM patients with no coronary or valve heart disease and 14 nondiabetic subjects. A median of 6 years follow-up information was obtained in 60 patients. Circulating GLP-1, dipeptidyl peptidase-4 activity, and biomarkers of OS were quantified. In T2DM patients, circulating GLP-1 decreased and OS biomarkers increased, compared with nondiabetics. Plasma GLP-1 was inversely correlated with serum 3-nitrotyrosine in T2DM patients. Patients showing high circulating 3-nitrotyrosine and low GLP-1 levels exhibited CR and higher risk for CVE, compared to the remaining patients. In palmitate-stimulated HL-1 cardiomyocytes, GLP-1 reduced cytosolic and mitochondrial oxidative stress, increased mitochondrial ATP synthase expression, partially restored mitochondrial membrane permeability and cytochrome c oxidase activity, blunted leakage of creatine to the extracellular medium, and inhibited oxidative damage in total and mitochondrial DNA. These results suggest that T2DM patients with reduced circulating GLP-1 and exacerbated OS may exhibit CR and be at higher risk for CVE. In addition, GLP-1 exerts antioxidant effects in HL-1 palmitate-overloaded cardiomyocytes. It is proposed that therapies aimed to increase GLP-1 may counteract OS, protect from CR, and prevent CVE in patients with T2DM. Topics: 8-Hydroxy-2'-Deoxyguanosine; Aged; Animals; Antioxidants; Atrial Remodeling; Cardiomegaly; Cardiovascular System; Case-Control Studies; Cell Line; Deoxyguanosine; Diabetes Mellitus, Type 2; Dipeptidyl Peptidase 4; Female; Glucagon-Like Peptide 1; Humans; Male; Mice; Middle Aged; Mitochondria; Myocytes, Cardiac; Oxidative Stress; Palmitic Acid; Pilot Projects; Retrospective Studies; Tyrosine; Ventricular Remodeling | 2015 |
Comment on Retnakaran et al. Liraglutide and the preservation of pancreatic β-cell function in early type 2 diabetes: the LIBRA trial. Diabetes Care 2014;37:3270-3278.
Topics: Cytoprotection; Diabetes Mellitus, Type 2; Female; Glucagon-Like Peptide 1; Humans; Hypoglycemic Agents; Insulin-Secreting Cells; Male | 2015 |
Response to Comment on Retnakaran et al. Liraglutide and the preservation of pancreatic β-cell function in early type 2 diabetes: the LIBRA trial. Diabetes Care 2014;37:3270-3278.
Topics: Cytoprotection; Diabetes Mellitus, Type 2; Female; Glucagon-Like Peptide 1; Humans; Hypoglycemic Agents; Insulin-Secreting Cells; Male | 2015 |
Incretin-based therapy and risk of acute pancreatitis: a nationwide population-based case-control study.
To investigate whether the use of incretin-based drugs (GLP-1 receptor agonists and dipeptidyl peptidase 4 [DPP4] inhibitors) is associated with acute pancreatitis.. The study was a nationwide population-based case-control study using medical databases in Denmark. Participants were 12,868 patients with a first-time hospitalization for acute pancreatitis between 2005 and 2012 and a population of 128,680 matched control subjects. The main outcome measure was the odds ratio (OR) for acute pancreatitis associated with different antihyperglycemic drugs. We adjusted for history of gallstones, alcoholism, obesity, and other pancreatitis-associated comorbidities and medications.. A total of 89 pancreatitis patients (0.69%) and 684 control subjects (0.53%) were ever users of incretins. The crude OR for acute pancreatitis among incretin users was 1.36 (95% CI 1.08-1.69), while it was 1.44 (95% CI 1.34-1.54) among users of other antihyperglycemic drugs. After confounder adjustment, the risk of acute pancreatitis was not increased among incretin users (OR 0.95 [95% CI 0.75-1.21]), including DPP4 inhibitor users (OR 1.04 [95% CI 0.80-1.37]) or GLP-1 receptor agonist users (OR 0.82 [95% CI 0.54-1.23]), or among nonincretin antihyperglycemic drug users (OR 1.05 [95% CI 0.98-1.13]), compared with nonusers of any antihyperglycemic drugs. Findings were similar in current versus ever drug users and in patients with pancreatitis risk factors. The adjusted OR comparing incretin-based therapy with other antihyperglycemic therapy internally while also adjusting for diabetes duration and complications was 0.97 (95% CI 0.76-1.23).. Our findings suggest that the use of incretin-based drugs appears not to be associated with an increased risk of acute pancreatitis. Topics: Acute Disease; Adolescent; Adult; Aged; Databases, Factual; Denmark; Diabetes Mellitus, Type 2; Dipeptidyl-Peptidase IV Inhibitors; Epidemiologic Methods; Female; Glucagon-Like Peptide 1; Hospitalization; Humans; Hypoglycemic Agents; Incretins; Male; Middle Aged; Pancreatitis; Young Adult | 2015 |
[Construction of yeast strains expressing long-acting glucagon-like peptide-1 (GLP-1) and their therapeutic effects on type 2 diabetes mellitus mouse model].
Probiotics, i.e., bacteria expressing therapeutic peptides (protein), are used as a new type of orally administrated biologic drugs to treat diseases. To develop yeast strains which could effectively prevent and treat type 2 diabetes mellitus, we firstly constructed the yeast integrating plasmid pNK1-PGK which could successfully express green fluorescent protein (GFP) in Saccharomyces cerevisiae. The gene encoding ten tandem repeats of glucagon-like peptide-1(10 × GLP-1) was cloned into the vector pNK1-PGK and the resulting plasmids were then transformed into the S. cerevisiae INVSc1. The long-acting GLP-1 hypoglycemic yeast (LHY) which grows rapidly and expresses 10 × GLP-1 stably was selected by nutrition screening and Western blotting. The amount of 10 × GLP-1 produced by LHY reached 1.56 mg per gram of wet cells. Moreover, the oral administration of LHY significantly reduced blood glucose level in type 2 diabetic mice induced by streptozotocin plus high fat and high sugar diet.. 益生菌生物药物是指通过口服表达药用多肽(蛋白)的重组益生菌活细胞达到治疗疾病的新型口服给药系统。为了构建一种能有效防治2型糖尿病的酵母生物药物,文章首先构建了酿酒酵母(S.cerevisiae)整合型表达载体pNK1-PGK,并且通过绿色荧光蛋白(GFP)证明其表达功能正常,利用该载体将10×GLP-1 (Glucagon-like peptide-1)基因转化到酿酒酵母INVSc1中,通过营养缺陷型和Western blotting成功筛选出表达10×GLP-1的长效促胰岛素降糖酵母(Long-acting GLP-1 hypoglycemic yeast, LHY)。该酵母生长迅速,外源基因10×GLP-1表达稳定,表达量达到1.56 mg/g细胞湿重。通过链脲佐菌素和高脂高糖饮食联合诱导的方法构建了2型糖尿病小鼠模型,用LHY对其进行口服灌胃治疗,证明LHY具有较好疗效,明显降低血糖水平。. Topics: Animals; Blood Glucose; Diabetes Mellitus, Experimental; Diabetes Mellitus, Type 2; Glucagon-Like Peptide 1; Mice; Mice, Inbred C57BL; Plasmids; Saccharomyces cerevisiae; Streptozocin | 2015 |
In vitro bioactive properties of intact and enzymatically hydrolysed whey protein: targeting the enteroinsular axis.
Enzymatically hydrolysed milk proteins have a variety of biofunctional effects some of which may be beneficial in the management of type 2 diabetes mellitus. The purpose of this study was to evaluate the effect of commercially available intact and hydrolysed whey protein ingredients (DH 32, DH 45) on markers of the enteroinsular axis (glucagon like peptide-1 secretion, dipeptidyl peptidase IV inhibition, insulin secretion and antioxidant activity) before and after simulated gastrointestinal digestion (SGID). A whey protein hydrolysate, DH32, significantly enhanced (P < 0.05) insulin secretion from BRIN BD11 β-cells compared to the positive control (16.7 mM glucose and 10 mM Ala). The whey protein hydrolysates inhibited dipeptidyl peptidase IV activity, yielding half maximal inhibitory concentration values (IC50) of 1.5 ± 0.1 and 1.1 ± 0.1 mg mL(-1) for the DH 32 and DH 45, samples respectively, and were significantly more potent than the intact whey (P < 0.05). Enzymatic hydrolysis of whey protein significantly enhanced (P < 0.05) its antioxidant activity compared to intact whey, as measured by the oxygen radical absorbance capacity assay (ORAC). This antioxidant activity was maintained (DH 32, P > 0.05) or enhanced (DH 45, P < 0.05) following SGID. Intact whey stimulated GLP-1 secretion from enteroendocrine cells compared to vehicle control (P < 0.05). This data confirm that whey proteins and peptides can act through multiple targets within the enteroinsular axis and as such may have glucoregulatory potential. Topics: Animals; Biomarkers; Cell Line; Chemical Phenomena; Diabetes Mellitus, Type 2; Dietary Supplements; Digestion; Dipeptidyl-Peptidase IV Inhibitors; Enteroendocrine Cells; Glucagon-Like Peptide 1; Hypoglycemic Agents; Insulin; Insulin Secretion; Insulin-Secreting Cells; Kinetics; Mice; Oxidants; Oxidative Stress; Protein Hydrolysates; Rats; Whey Proteins | 2015 |
Central Nervous System Regulation of Intestinal Lipoprotein Metabolism by Glucagon-Like Peptide-1 via a Brain-Gut Axis.
Intestinal overproduction of atherogenic chylomicron particles postprandially is an important component of diabetic dyslipidemia in insulin-resistant states. In addition to enhancing insulin secretion, peripheral glucagon-like peptide-1 (GLP-1) receptor stimulation has the added benefit of reducing this chylomicron overproduction in patients with type 2 diabetes mellitus. Given the presence of central GLP-1 receptors and GLP-1-producing neurons, we assessed whether central GLP-1 exerts an integral layer of neuronal control during the production of these potentially atherogenic particles.. Postprandial production of triglyceride-rich lipoproteins was assessed in Syrian hamsters administered a single intracerebroventricular injection of the GLP-1 receptor agonist exendin-4. Intracerebroventricular exendin-4 reduced triglyceride-rich lipoprotein-triglyceride and -apolipoprotein B48 accumulation relative to vehicle-treated controls. This was mirrored by intracerebroventricular MK-0626, an inhibitor of endogenous GLP-1 degradation, and prevented by central exendin9-39, a GLP-1 receptor antagonist. The effects of intracerebroventricular exendin-4 were also lost during peripheral adrenergic receptor and central melanocortin-4 receptor inhibition, achieved using intravenous propranolol and phentolamine and intracerebroventricular HS014, respectively. However, central exendin9-39 did not preclude the effects of peripheral exendin-4 treatment on chylomicron output.. Central GLP-1 is a novel regulator of chylomicron production via melanocortin-4 receptors. Our findings point to the relative importance of central accessibility of GLP-1-based therapies and compel further studies examining the status of this brain-gut axis in the development of diabetic dyslipidemia and chylomicron overproduction. Topics: Animals; Central Nervous System; Chylomicrons; Cricetinae; Diabetes Mellitus, Type 2; Disease Models, Animal; Exenatide; Glucagon-Like Peptide 1; Glucagon-Like Peptide-1 Receptor; Intestinal Mucosa; Intestines; Lipid Metabolism; Lipoproteins; Peptides; Random Allocation; Receptors, Glucagon; Venoms | 2015 |
GLP-1 Response to Oral Glucose Is Reduced in Prediabetes, Screen-Detected Type 2 Diabetes, and Obesity and Influenced by Sex: The ADDITION-PRO Study.
The role of glucose-stimulated release of GLP-1 in the development of obesity and type 2 diabetes is unclear. We assessed GLP-1 response to oral glucose in a large study population of lean and obese men and women with normal and impaired glucose regulation. Circulating concentrations of glucose, insulin, and GLP-1 during an oral glucose tolerance test (OGTT) were analyzed in individuals with normal glucose tolerance (NGT) (n = 774), prediabetes (n = 525), or screen-detected type 2 diabetes (n = 163) who attended the Danish ADDITION-PRO study (n = 1,462). Compared with individuals with NGT, women with prediabetes or type 2 diabetes had 25% lower GLP-1 response to an OGTT, and both men and women with prediabetes or type 2 diabetes had 16-21% lower 120-min GLP-1 concentrations independent of age and obesity. Obese and overweight individuals had up to 20% reduced GLP-1 response to oral glucose compared with normal weight individuals independent of glucose tolerance status. Higher GLP-1 responses were associated with better insulin sensitivity and β-cell function, older age, and lesser degree of obesity. Our findings indicate that a reduction in GLP-1 response to oral glucose occurs prior to the development of type 2 diabetes and obesity, which can have consequences for early prevention strategies for diabetes. Topics: Age Factors; Aged; Blood Glucose; Body Mass Index; Diabetes Mellitus, Type 2; Female; Glucagon-Like Peptide 1; Glucose Tolerance Test; Humans; Insulin; Male; Middle Aged; Obesity; Prediabetic State; Sex Characteristics; Waist Circumference | 2015 |
Determining predictors of early response to exenatide in patients with type 2 diabetes mellitus.
Exenatide is a GLP-1 analogue used in the management of T2DM yet within a subset of patients fails due to adverse side effects or from failure to attain the end goal. This retrospective observational study aimed to determine whether we could predict response to exenatide in patients with T2DM. 112 patients on exenatide were included with patient age, gender, duration of T2DM, medications alongside exenatide and weight, BMI, and HbA1c at baseline and 3 and 6 months of exenatide use being recorded. 63 responded with 11 mmol/mol reduction from baseline HbA1c after six months and 49 did not respond to exenatide. HbA1c solely differed significantly between cohorts at baseline, 3 months, and 6 months (P < 0.05). Regression analyses identified a negative linear relationship with higher baseline HbA1c correlating to greater reductions in HbA1c by 6 months (P < 0.0001). HbA1c was the sole predictor of exenatide response with higher baseline HbA1c increasing the odds of response by 5% (P = 0.004). Patients with HbA1c reductions ≥15-20% by 3 months were more likely to be responders by 6 months (P = 0.033). Our study identified that baseline HbA1c acted as the sole predictor of exenatide response and that response may be determined after 3 months of exenatide administration. Topics: Aged; Anthropometry; Body Mass Index; Body Weight; Diabetes Mellitus, Type 2; Exenatide; Female; Glucagon-Like Peptide 1; Humans; Hypoglycemic Agents; Linear Models; Liraglutide; Male; Middle Aged; Peptides; Predictive Value of Tests; Regression Analysis; Retrospective Studies; Treatment Outcome; Venoms | 2015 |
Can a fixed-ratio combination of insulin degludec and liraglutide help Type 2 diabetes patients to optimize glycemic control across the day?
'IDegLira' combines insulin degludec (IDeg) with the glucagon-like peptide-1 analog liraglutide (Lira) at a ratio of 1 unit IDeg to 0.036 mg Lira. The two components have complementary therapeutic actions for the treatment of Type 2 diabetes. Studies have shown that combinations of basal insulin with glucagon-like peptide-1 receptor agonists can be clinically successful, lowering elevated blood glucose with a low risk of hypoglycemia and weight gain. IDegLira is being assessed in a series of studies (two already published), which provide insights into its clinical utility in previously insulin-naive patients and those failing to achieve good glycemic control on a basal-only insulin regimen. This article critically examines the available data to assess the product's likely clinical profile. Topics: Blood Glucose; Diabetes Mellitus, Type 2; Drug Combinations; Glucagon-Like Peptide 1; Humans; Hypoglycemic Agents; Insulin; Insulin, Long-Acting; Liraglutide; Treatment Outcome | 2015 |
Moving towards a more precise treatment of diabetes.
Topics: Diabetes Mellitus, Type 2; Gastric Inhibitory Polypeptide; Glucagon-Like Peptide 1; Humans; Hypoglycemic Agents; Precision Medicine; Receptors, Glucagon | 2015 |
Ezetimibe stimulates intestinal glucagon-like peptide 1 secretion via the MEK/ERK pathway rather than dipeptidyl peptidase 4 inhibition.
Ezetimibe is known as a Niemann-Pick C1-Like 1 (NPC1L1) inhibitor and has been used as an agent for hypercholesterolemia. In our previous study, ezetimibe administration improved glycemic control and increased glucagon like peptide-1 (GLP-1), an incretin hormone with anti-diabetic properties. However, the mechanisms by which ezetimibe stimulates GLP-1 secretion are not fully understood. Thus, the specific aim of this study was to investigate the mechanism(s) by which ezetimibe stimulates GLP-1 secretion.. Male KK/H1J mice were divided into following groups: AIN-93G (NC), NC with ezetimibe (10 mg/kg/day), 45% high fat (HF) diet, and HF diet with ezetimibe. To investigate the role of ezetimibe in glucose homeostasis and GLP-1 secretion, an insulin tolerance test was performed and serum and intestinal GLP-1 levels and intestinal mRNA expression involved in GLP-1 synthesis were measured after 6 weeks of ezetimibe treatment. In vivo and in vitro dipeptidyl peptidase-4 (DPP-4) inhibition assays were employed to demonstrate the association between ezetimibe-induced GLP-1 change and DPP-4. The molecular mechanism by which ezetimibe affects GLP-1 secretion was evaluated by using human enteroendocrine NCI-H716 cells.. Ezetimibe supplementation significantly ameliorated HF-increased glucose and insulin resistance in the type 2 diabetic KK/H1J mouse model. Serum and intestinal active GLP-1 levels were significantly increased by ezetimibe in HF-fed animals. However, mRNA expression of genes involved in intestinal GLP-1 synthesis was not altered. Furthermore, ezetimibe did not inhibit the activity of either in vivo or in vitro dipeptidyl peptidase-4 (DPP-4). The direct effects of ezetimibe on GLP-1 secretion and L cell secretory mechanisms were examined in human NCI-H716 intestinal cells. Ezetimibe significantly stimulated active GLP-1 secretion, which was accompanied by the activation of mitogen-activated protein/extracellular signal-regulated kinase kinase (MEK)/extracellular signal-regulated kinase (ERK). Ezetimibe-increased GLP-1 secretion was abrogated by inhibiting the MEK/ERK pathway with PD98059.. These findings suggest a possible novel biological role of ezetimibe in glycemic control to stimulate intestinal GLP-1 secretion via the MEK/ERK signaling pathway. Topics: Animals; Azetidines; Blood Glucose; Blotting, Western; Diabetes Mellitus, Type 2; Dipeptidyl-Peptidase IV Inhibitors; Ezetimibe; Glucagon-Like Peptide 1; Insulin; Intestinal Mucosa; L Cells; Male; MAP Kinase Signaling System; Mice; Rats; Rats, Sprague-Dawley; Specific Pathogen-Free Organisms | 2015 |
Care trajectories are associated with quality improvement in the treatment of patients with uncontrolled type 2 diabetes: A registry based cohort study.
To analyse whether care trajectories (CT) were associated with increased prevalence of parenteral hypoglycemic treatment (PHT=insulin or GLP-1 analogues), statin therapy or RAAS-inhibition. Introduced in 2009 in Belgium, CTs target patients with type 2 diabetes mellitus (T2DM), in need for or with PHT.. Retrospective study based on a registry with 97 general practitioners. The evolution in treatment since 2006 was compared between patients with vs. without a CT, using longitudinal logistic regression.. Comparing patients with (N=271) vs. without a CT (N=4424), we noted significant differences (p<0.05) in diabetes duration (10.1 vs. 7.3 years), HbA1c (7.5 vs. 6.9%), LDL-C (85 vs. 98mg/dl), microvascular complications (26 vs. 16%). Moreover, in 2006, parenteral treatment (OR 52.1), statins (OR 4.1) and RAAS-inhibition (OR 9.6) were significantly more prevalent (p<0.001). Between 2006 and 2011, the prevalence rose in both groups regarding all three treatments, but rose significantly faster (p<0.05) after 2009 in the CT-group.. Patients enrolled in a CT differ from other patients even before the start of this initiative with more intense hypoglycemic and cardiovascular treatment. Yet, they presented higher HbA1c-levels and more complications. Enrolment in a CT is associated with additional treatment intensification. Topics: Aged; Angiotensin II Type 1 Receptor Blockers; Angiotensin-Converting Enzyme Inhibitors; Belgium; Biomarkers; Blood Glucose; Cholesterol, LDL; Critical Pathways; Diabetes Mellitus, Type 2; Diabetic Angiopathies; Female; General Practice; Glucagon-Like Peptide 1; Glycated Hemoglobin; Humans; Hydroxymethylglutaryl-CoA Reductase Inhibitors; Hypoglycemic Agents; Incretins; Insulin; Linear Models; Logistic Models; Male; Odds Ratio; Quality Improvement; Quality Indicators, Health Care; Registries; Retrospective Studies; Risk Factors; Time Factors; Treatment Outcome | 2015 |
Therapy with proton pump inhibitors in patients with type 2 diabetes is independently associated with improved glycometabolic control.
Experimental data demonstrated that gastrin has incretin-like stimulating actions on β-cells, resulting in a promotion of glucose-induced insulin secretion. As proton pump inhibitors (PPIs) consistently increase plasma gastrin levels, a possible effect of this treatment on glucose-insulin homeostasis may be hypothesized. Therefore, the aim of this study was to evaluate the effect of chronic PPIs treatment on glycemic control in patients affected by type 2 diabetes.. This is an observational, retrospective study. A total of 548 consecutive patients with type 2 diabetes (mean age ± SD: 67.1 ± 10.9 years, M/F: 309/239, diabetes duration: 12.4 ± 9.8 years) referring to our diabetes outpatient clinics were enrolled; among them, 45 %were treated with PPIs longer than 2 years for preventive/therapeutic purposes. Fasting plasma glucose (FPG), glycated hemoglobin (HbA1c), serum lipids and transaminases were measured by standard laboratory methods. Major cardiovascular events and concomitant medications were recorded in all participants, and daily insulin requirement was calculated in insulin-treated subjects.. PPIs-treated patients had significantly lower HbA1c (7.1 ± 1.07 %-54.1 ± 12 vs 7.4 ± 1.4 %-57.4 ± 8 mmol/mol, p = 0.011) and FPG (127 ± 36.9 vs 147.6 ± 49.4 mg/dl, p < 0.001) levels than those untreated. These differences increased in patients under insulin therapy and in those with concomitant PPIs + GLP-1-based therapy. The multivariate regression analysis demonstrated that the association between chronic PPIs treatment and HbA1c was independent from possible confounders (p = 0.01).. PPIs treatment is associated with greater glycemic control in patients with type 2 diabetes, particularly in those on insulin- or GLP-1-based therapy. Our results suggest a role for PPIs in glucose-insulin homeostasis and may open a new scenario for diabetes therapy. Topics: Aged; Blood Glucose; Diabetes Mellitus, Type 2; Fasting; Female; Glucagon-Like Peptide 1; Glycated Hemoglobin; Homeostasis; Humans; Insulin; Male; Middle Aged; Proton Pump Inhibitors; Retrospective Studies | 2015 |
Dipeptidyl peptidase-4 inhibition in diabetic rats leads to activation of the transcription factor CREB in β-cells.
Incretin therapies are effective in controlling blood glucose levels in type 2 diabetic patients by improving the survival and function of β-cells. They include dipeptidyl peptidase-4 (DPP-4) inhibitors and long-acting glucagon-like peptide-1 (GLP-1) analogs. We have previously reported that GLP-1 enhances the survival of cultured human islets by activation of the transcription factor CREB. To test the in vivo relevance of these findings, we examined the effects of alogliptin, a DPP-4 inhibitor, in Zucker Diabetic rats, a model for type 2 diabetes. The plasma levels of GLP-1 increased in alogliptin-treated diabetic rats leading to normoglycemia. Pancreatic islets of untreated diabetic rats were characterized by decreased immunostaining for insulin and PDX-1. Elevation of GLP-1 in treated diabetic rats resulted in the improved survival of β-cells. Dual immunofluorescent staining showed phosphorylation/activation of CREB in insulin-positive β-cells of islets. This led to increases in the levels of CREB targets including Bcl-2, an antiapoptotic mitochondrial protein, BIRC3, a caspase inhibitor and IRS-2, an adapter protein needed for insulin signaling. Findings from this study suggest potential activation of cytoprotective CREB by GLP-1 in pancreatic β-cells of diabetic patients undergoing incretin-based therapies. Topics: Animals; Baculoviral IAP Repeat-Containing 3 Protein; Blood Glucose; Cyclic AMP Response Element-Binding Protein; Diabetes Mellitus, Experimental; Diabetes Mellitus, Type 2; Dipeptidyl-Peptidase IV Inhibitors; Glucagon-Like Peptide 1; Inhibitor of Apoptosis Proteins; Insulin; Insulin Receptor Substrate Proteins; Insulin-Secreting Cells; Male; Piperidines; Proto-Oncogene Proteins c-bcl-2; Rats, Zucker; Triglycerides; Uracil | 2015 |
Liraglutide-related cholelithiasis.
Liraglutide is a glucagon-like peptide-1 analog and recently started to be using as an incretin-based treatment for diabetes mellitus. Liraglutide causes some adverse affects including nausea, vomiting, acute nasopharyngitis and acute pancreatitis. However, development of liraglutide-dependent cholelithiasis has not been reported in the literature. A 75-year-old female patient had been diagnosed with type 2 diabetes mellitus for 10 years and she has been treated by liraglutide for 6 months. The patient was admitted to the emergency service due to sudden onset of abdominal pain. After laboratory and imaging studies, she was diagnosed with acute cholecystitis and cholelithiasis. And then patient's oral intake was stopped, intravenous fluid and ceftriaxone 2 g/day were started. Furthermore, liraglutide treatment discontinued and ursodeoxycholic acid (UDCA) was started to treat cholelithiasis. During follow-up, abdominal pain completely relieved. Hepatobiliary ultrasonography in sixth month follow-up showed entirely regression of cholelithiasis. Any liraglutide-related cholelithiasis case has not been reported in the literature previously. Therefore, our case is the first case. Especially, elderly diabetic patients who are started to liraglutide treatment should be monitored closely for the formation of cholelithiasis. UDCA treatment would be an alternative prior to surgical treatment for liraglutide-related cholelithiasis. Topics: Aged; Cholagogues and Choleretics; Cholelithiasis; Diabetes Mellitus, Type 2; Female; Glucagon-Like Peptide 1; Humans; Hypoglycemic Agents; Liraglutide; Treatment Outcome; Ursodeoxycholic Acid; Withholding Treatment | 2015 |
Expedited Biliopancreatic Juice Flow to the Distal Gut Benefits the Diabetes Control After Duodenal-Jejunal Bypass.
Serum bile acids (BAs) are elevated after metabolic surgeries including Roux-en-Y gastric bypass (RYGB), ileal transposition (IT), and duodenal-jejunal bypass (DJB). Recently, BAs have emerged as a kind of signaling molecules, which can not only promote glucagon-like peptide-1 (GLP-1) secretion but can also regulate multiple enzymes involved in glucose metabolism. The aim of this study was to investigate whether expedited biliopancreatic juice flow to the distal gut contributes to the increased serum GLP-1 and BAs and benefits the diabetes control after DJB.. DJB, long alimentary limb DJB (LDJB), duodenal-jejunal anastomosis (DJA), and sham operation were performed in diabetic rats induced by high-fat diet (HFD) and low dose of streptozotocin (STZ). Body weight, food intake, oral glucose tolerance, insulin tolerance, glucose-stimulated insulin and GLP-1 secretion, fasting serum total bile acids (TBAs), and lipid profiles were measured at indicated time points.. Compared with sham operation, DJA, DJB, and LDJB all achieved rapid and dramatic improvements in glucose tolerance and insulin sensitivity independently of food restriction and weight loss. DJB and LDJB-operated rats exhibited even better glucose tolerance, higher fasting serum TBAs, and higher glucose-stimulated GLP-1 secretion than the DJA group postoperatively. No difference was detected in insulin sensitivity and glucose-stimulated insulin secretion between DJA, DJB, and LDJB groups.. Expedited biliopancreatic juice flow to the distal gut was associated with augmented GLP-1 secretion and increased fasting serum TBA concentration, which may partly explain the metabolic benefits of DJB. Topics: Animals; Bile; Bile Acids and Salts; Blood Glucose; Diabetes Mellitus, Experimental; Diabetes Mellitus, Type 2; Diet, High-Fat; Duodenum; Gastric Bypass; Glucagon-Like Peptide 1; Glucose Tolerance Test; Insulin; Insulin Resistance; Jejunum; Male; Pancreatic Juice; Rats; Rats, Wistar | 2015 |
Reduction of insulinotropic properties of GLP-1 and GIP after glucocorticoid-induced insulin resistance.
We evaluated the insulinotropic properties of glucagon-like peptide-1 (GLP-1) and glucose-dependent insulinotropic polypeptide (GIP) in healthy individuals at risk of developing type 2 diabetes before and after glucocorticoid-induced insulin resistance.. Nineteen healthy, glucose tolerant, first-degree relatives of type 2 diabetic patients underwent OGTT and 7 mmol/l and 15 mmol/l glucose clamps with concomitant infusions of GLP-1, GIP or NaCl and a final infusion of arginine for determination of maximum beta cell capacity before and after treatment with dexamethasone. In addition, first-phase insulin responses were determined at 7 mmol/l and 15 mmol/l and second-phase insulin responses at 7 mmol/l.. After dexamethasone treatment, all 19 participants had increased insulin resistance (HOMA-IR and insulin sensitivity index [M/I] values) and 2 h plasma glucose concentrations, while beta cell function indices generally increased according to the increased resistance. First-phase insulin responses induced by GLP-1 and GIP at 7 mmol/l and maximal beta cell secretory capacity did not differ before and after dexamethasone, while second-phase responses to 7 mmol/l and first-phase responses to 15 mmol/l glucose were reduced equally for both hormones.. Glucocorticoid-induced insulin resistance in individuals at risk of type 2 diabetes leads to a reduced insulinotropic effect of the incretin hormones. This reduction was not associated with a decrease in the maximal beta cell secretory capacity, indicating that the reduced incretin effect in the developing dysglycaemia of the present experimental model is due to a specific early reduction of the insulinotropic effects of the incretin hormones.. Clinicaltrials.gov NCT02235584. Topics: Adult; Blood Glucose; Dexamethasone; Diabetes Mellitus, Type 2; Female; Gastric Inhibitory Polypeptide; Glucagon-Like Peptide 1; Glucocorticoids; Glucose Clamp Technique; Glucose Tolerance Test; Humans; Insulin; Insulin Resistance; Male; Risk Factors | 2015 |
Polymorphisms of GLP-1 receptor gene and response to GLP-1 analogue in patients with poorly controlled type 2 diabetes.
The relationship between genetic polymorphisms of the glucagon-like peptide-1 (GLP-1) receptor (GLP1R) gene and unresponsiveness to GLP-1 analogue treatment in patients with poorly controlled type 2 diabetes mellitus (DM) is unclear.. Thirty-six patients with poorly controlled type 2 DM were enrolled and they received six days of continuous subcutaneous insulin infusion for this study. After the normalization of blood glucose in the first 3 days, the patients then received a combination therapy with injections of the GLP-1 analogue, exenatide, for another 3 days. All 13 exons and intron-exon boundaries of the GLP1R gene were amplified to investigate the association.. The short tandem repeat at 8GA/7GA (rs5875654) had complete linkage disequilibrium (LD, with r2 = 1) with single nucleotide polymorphism (SNP) rs761386. Quantitative trait loci analysis of GLP1R gene variation with clinical response of GLP1 analogue showed the missense rs3765467 and rs761386 significantly associated with changes in the standard deviation of plasma glucose (SDPG(baseline) - SDPG(treatment with GLP-1 analogue)) (P = 0.041 and 0.019, resp.). The reported P values became insignificant after multiple testing adjustments.. The variable response to the GLP-1 analogue was not statistically correlated with polymorphisms of the GLP1R gene in patients with poorly controlled type 2 DM. Topics: Blood Glucose; Diabetes Mellitus, Type 2; Female; Genotype; Glucagon-Like Peptide 1; Glucagon-Like Peptide-1 Receptor; Glucose Tolerance Test; Hospitalization; Humans; Hypoglycemia; Infusions, Subcutaneous; Insulin; Linkage Disequilibrium; Male; Microsatellite Repeats; Middle Aged; Mutation, Missense; Polymorphism, Genetic; Polymorphism, Single Nucleotide; Quantitative Trait Loci; Sequence Analysis, DNA | 2015 |
β-Hydroxypyruvate: a new diabetogenic factor?
Topics: Animals; Diabetes Mellitus, Type 2; Enteroendocrine Cells; Female; Gastric Inhibitory Polypeptide; Glucagon-Like Peptide 1; Humans; Male; Pyruvates | 2015 |
Effects of sitagliptin on the serum creatinine in Japanese type 2 diabetes.
We found a slight elevation of serum creatinine in the subjects treated with sitagliptin for 2 years and a correlation between creatinine elevation and HbA1c reduction. These results suggest that creatinine elevation is associated with activation of incretin, most possibly with up-regulation of diuretic activity of GLP-1. Topics: Aged; Creatinine; Diabetes Mellitus, Type 2; Dipeptidyl-Peptidase IV Inhibitors; Female; Glucagon-Like Peptide 1; Glycated Hemoglobin; Humans; Japan; Male; Middle Aged; Retrospective Studies; Sitagliptin Phosphate | 2015 |
The anti-diabetic effects of GLP-1-gastrin dual agonist ZP3022 in ZDF rats.
Combination treatment with exendin-4 and gastrin has proven beneficial in treatment of diabetes and preservation of beta cell mass in diabetic mice. Here, we examined the chronic effects of a GLP-1-gastrin dual agonist ZP3022 on glycemic control and beta cell dysfunction in overtly diabetic Zucker Diabetic Fatty (ZDF) rats.. ZDF rats aged 11 weeks were dosed s.c., b.i.d. for 8 weeks with vehicle, ZP3022, liraglutide, exendin-4, or gastrin-17 with or without exendin-4. Glycemic control was assessed by measurements of HbA1c and blood glucose levels, as well as glucose tolerance during an oral glucose tolerance test (OGTT). Beta cell dynamics were examined by morphometric analyses of beta and alpha cell fractions.. ZP3022 improved glycemic control as measured by terminal HbA1c levels (6.2±0.12 (high dose) vs. 7.9±0.07% (vehicle), P<0.001), as did all treatments, except gastrin-17 monotherapy. In contrast, only ZP3022, exendin-4 and combination treatment with exendin-4 and gastrin-17 significantly improved glucose tolerance and increased insulin levels during an OGTT. Moreover, only ZP3022 significantly enhanced the beta cell fraction in ZDF rats, a difference of 41%, when compared to the vehicle group (0.31±0.03 vs. 0.22±0.02%, respectively, P<0.05).. These data suggest that ZP3022 may have therapeutic potential in the prevention/delay of beta cell dysfunction in type 2 diabetes. Topics: Animals; Blood Glucose; Diabetes Mellitus, Experimental; Diabetes Mellitus, Type 2; Gastrins; Glucagon-Like Peptide 1; Glycated Hemoglobin; Humans; Insulin; Insulin-Secreting Cells; Mice; Peptides; Rats; Rats, Zucker | 2015 |
Effects of exenatide on postprandial vascular endothelial dysfunction in type 2 diabetes mellitus.
Basic studies have shown that glucagon-like peptide-1 (GLP-1) analogs exert a direct protective effect on the vascular endothelium in addition to their indirect effects on postprandial glucose and lipid metabolism. GLP-1 analogs are also reported to inhibit postprandial vascular endothelial dysfunction. This study examined whether the GLP-1 analog exenatide inhibits postprandial vascular endothelial dysfunction in patients with type 2 diabetes mellitus (T2DM).. Seventeen patients with T2DM underwent a meal tolerance test to examine changes in postprandial vascular endothelial function and in glucose and lipid metabolism, both without exenatide (baseline) and after a single subcutaneous injection of 10 μg exenatide. Vascular endothelial function was determined using reactive hyperemia index (RHI) measured by peripheral arterial tonometry before and 120 min after the meal loading test. The primary endpoint was the difference in changes in postprandial vascular endothelial function between the baseline and exenatide tests.. The natural logarithmically-scaled RHI (L_RHI) was significantly lower after the baseline meal test but not in the exenatide test. The use of exenatide resulted in a significant decrease in triglycerides (TG) area under the curve and coefficient of variation (CV). The change in L_RHI correlated with changes in CV of triglycerides and HDL-cholesterol. Multivariate analysis identified changes in triglyceride CV as the only determinant of changes in L_RHI, contributing to 41% of the observed change.. Exenatide inhibited postprandial vascular endothelial dysfunction after the meal loading test, suggesting that exenatide has a multiphasic anti-atherogenic action involving not only glucose but also lipid metabolism.. ClinicalTrials.gov: UMIN000015699. Topics: Adult; Aged; Diabetes Mellitus, Type 2; Endothelium, Vascular; Exenatide; Female; Glucagon-Like Peptide 1; Humans; Hypoglycemic Agents; Male; Middle Aged; Peptides; Postprandial Period; Venoms | 2015 |
Expression of CTB-10×rolGLP-1 in E. coli and its therapeutic effect on type 2 diabetes.
Glucagon-like peptide-1 (GLP-1) is a short peptide that can significantly reduce blood glucose level. Recombination oral long-acting glucagon-like peptide-1 (rolGLP-1), is a GLP-1 analog generated from site-specific mutation of GLP-1. CTB is a non-toxic portion of the cholera toxin and an ideal protein antigen carrier. In this study, we firstly constructed a vector pET-22b (+)-CTB-10×rolGLP-1 to express a fusion protein composed of CTB and ten tandem repeated rolGLP-1 in BL21 (DE3) line of E. coli. The CTB-10×rolGLP-1 was expressed efficiently in the inclusion bodies. The expression product was analyzed by SDS-PAGE electrophoresis and Western blotting. The inclusion bodies were then denatured, refolded and purified by ion exchange chromatography to obtain a high-purity CTB- 10×rolGLP-1. The therapeutic effect of CTB-10×rolGLP-1 was assessed in comparison with 10×rolGLP-1 alone by daily oral-gavage administration up to 10 days in streptozotocin-induced type 2 diabetic mice. The results showed that the level of blood glucose was reduced more effectively and the oral glucose tolerance of mice was improved more significantly with the administration of CTB-10×rolGLP-1. Our results provided a potentially promising oral biological drug for the treatment of type 2 diabetes. Topics: Administration, Oral; Animals; Blood Glucose; Cholera Toxin; Diabetes Mellitus, Type 2; Drug Combinations; Escherichia coli; Glucagon-Like Peptide 1; Hypoglycemic Agents; Male; Mice; Protein Engineering; Recombinant Fusion Proteins; Treatment Outcome | 2015 |
Retrospective study comparing healthcare costs and utilization between commercially insured patients with type 2 diabetes mellitus who are newly initiating exenatide once weekly or liraglutide in the United States.
To compare healthcare costs and utilization between commercially insured patients with type 2 diabetes mellitus (T2DM) in the United States newly initiating exenatide once weekly (QW) or liraglutide.. This retrospective cohort study used US administrative claims data to study patients with T2DM initiating exenatide QW or liraglutide (initiated therapy = index therapy). Patients were included if they had T2DM, were glucagon-like peptide-1 receptor agonist (GLP-1RA) naïve, initiated exenatide QW or liraglutide from 1 February 2012 to 1 October 2012 (date of initiation = index), were ≥18 years at index, and had continuous enrollment for 12 months before (baseline) to 6 months after index (follow-up). Study outcomes were overall and diabetes-specific healthcare utilization and costs. Multivariable regressions compared the study outcomes between exenatide QW and liraglutide, adjusting for potential confounders. Sensitivity analyses were performed to assess liraglutide by dose (1.2 mg/1.8 mg).. The study sample included 9106 liraglutide (4188, 1.2 mg; 4918, 1.8 mg) patients and 2445 exenatide QW patients. In multivariable-adjusted analyses, compared with liraglutide patients, exenatide QW patients had statistically significantly lower odds of overall inpatient admissions (odds ratio [OR] = 0.80, p = 0.046) and diabetes-specific (OR = 0.83, p = 0.026) inpatient admissions, similar overall total costs ($7833 exenatide QW, $8296 liraglutide, p = 0.069) and diabetes-specific total costs ($3610 exenatide QW, $3736 liraglutide, p = 0.298), and statistically significantly lower overall medical costs ($3939 exenatide QW, $4652 liraglutide, p = 0.008) and diabetes-specific medical costs ($1161 exenatide QW, $1469 liraglutide, p = 0.007). Sensitivity analyses assessing liraglutide by dose were directionally consistent. Unadjusted exploratory analyses showed that exenatide QW patients obtained a greater median number of days supplied for their GLP-1RA during follow-up (141 days) than liraglutide patients (124 days).. In this 6 month follow-up study, patients receiving exenatide QW had similar total healthcare costs but lower odds of inpatient admission and lower medical costs compared with patients receiving liraglutide. Topics: Comorbidity; Diabetes Mellitus, Type 2; Drug Administration Schedule; Exenatide; Fees, Pharmaceutical; Female; Glucagon-Like Peptide 1; Health Expenditures; Humans; Hypoglycemic Agents; Insurance Coverage; Insurance, Health; Liraglutide; Male; Middle Aged; Models, Econometric; Patient Acceptance of Health Care; Peptides; Retrospective Studies; Severity of Illness Index; United States; Venoms | 2015 |
Preoperative β-cell function in patients with type 2 diabetes is important for the outcome of Roux-en-Y gastric bypass surgery.
The majority of the patients with type 2 diabetes (T2DM) show remission after Roux-en-Y gastric bypass (RYGB). This is the result of increased postoperative insulin sensitivity and β-cell secretion. The aim of the present study was to elucidate the importance of the preoperative β-cell function in T2DM for the chance of remission after RYGB. Fifteen patients with and 18 without T2DM had 25 g oral (OGTT) and intravenous (IVGTT) glucose tolerance tests performed at inclusion, after a diet-induced weight loss, and 4 and 18 months after RYGB. Postoperative first phase insulin secretion rate (ISR) during the IVGTT and β-cell glucose sensitivity during the OGTT increased in T2DM. Postoperative insulin sensitivity and the disposition index (DI) markedly increased in both groups. By stratifying the T2DM into two groups according to highest (T2DMhigh ) and lowest (T2DMlow ) baseline DI, a restoration of first phase ISR and β-cell glucose sensitivity were seen only in T2DMhigh . Remission of type 2 diabetes was 71 and 38% in T2DMhigh and T2DMlow , respectively. Postoperative postprandial GLP-1 concentrations increased markedly, but did not differ between the groups. Our findings emphasize the importance of the preoperative of β-cell function for remission of diabetes after RYGB. Topics: Adult; Anastomosis, Roux-en-Y; Blood Glucose; Diabetes Mellitus, Type 2; Female; Glucagon-Like Peptide 1; Humans; Insulin; Insulin Secretion; Insulin-Secreting Cells; Male; Obesity; Preoperative Period | 2015 |
Are we waiting too long for the cardiovascular outcome trials with the glucagon-like peptide-1 receptor agonists?
Several new medicines are in development for the treatment of type 2 diabetes, and cardiovascular outcome trials are the gold standard for these medicines. This editorial demonstrates that despite being available for over 10 years, there are no cardiovascular outcome studies for any of the glucagon-like peptide-1 receptor agonists, which demonstrate cardiovascular safety or benefit in subjects with high cardiovascular risk. The author argues that the FDA should be ensuring that clinical outcome studies for subjects with type 2 diabetes and high cardiovascular risk be undertaken in a timelier manner. Topics: Cardiovascular Diseases; Clinical Trials as Topic; Diabetes Mellitus, Type 2; Drug Design; Glucagon-Like Peptide 1; Humans; Hypoglycemic Agents; Risk; Time Factors | 2015 |
The effect of combined treatment with canagliflozin and teneligliptin on glucose intolerance in Zucker diabetic fatty rats.
To assess the impact of concomitant inhibition of sodium-glucose cotransporter (SGLT) 2 and dipeptidyl peptidase IV (DPP4) for the treatment of type 2 diabetes mellitus (T2DM), the effect of combined treatment with canagliflozin, a novel SGLT2 inhibitor, and teneligliptin, a DPP4 inhibitor, on glucose intolerance was investigated in Zucker diabetic fatty (ZDF) rats. Canagliflozin potently inhibited human and rat SGLT2 and moderately inhibited human and rat SGLT1 activities but did not affect DPP4 activity. In contrast, teneligliptin inhibited human and rat DPP4 activities but not SGLT activities. A single oral treatment of canagliflozin and teneligliptin suppressed plasma glucose elevation in an oral glucose tolerance test in 13 week-old ZDF rats. This combination of agents elevated plasma active GLP-1 levels in a synergistic manner, probably mediated by intestinal SGLT1 inhibition, and further improved glucose intolerance. In the combination-treated animals, there was no pharmacokinetic interaction of the drugs and no further inhibition of plasma DPP4 activity compared with that in the teneligliptin-treated animals. These results suggest that the inhibition of SGLT2 and DPP4 improves glucose intolerance and that combined treatment with canagliflozin and teneligliptin is a novel therapeutic option for glycemic control in T2DM. Topics: Administration, Oral; Animals; Canagliflozin; Cells, Cultured; Cricetinae; Cricetulus; Diabetes Mellitus, Type 2; Dipeptidyl Peptidase 4; Dipeptidyl-Peptidase IV Inhibitors; Drug Therapy, Combination; Glucagon-Like Peptide 1; Glucose Intolerance; Humans; Hypoglycemic Agents; Male; Pyrazoles; Rats, Zucker; Sodium-Glucose Transporter 1; Sodium-Glucose Transporter 2; Sodium-Glucose Transporter 2 Inhibitors; Thiazolidines | 2015 |
Nutrient induced type 2 and chemical induced type 1 experimental diabetes differently modulate gastric GLP-1 receptor expression.
T2DM patients demonstrate reduced GLP-1 receptor (GLP-1R) expression in their gastric glands. Whether induced T2DM and T1DM differently affect the gastric GLP-1R expression is not known. This study assessed extrapancreatic GLP-1R system in glandular stomach of rodents with different types of experimental diabetes. T2DM and T1DM were induced in Psammomys obesus (PO) by high-energy (HE) diet and by streptozotocin (STZ) in Sprague Dawly (SD) rats, respectively. GLP-1R expression was determined in glandular stomach by RT PCR and immunohistomorphological analysis. The mRNA expression and cellular association of the GLP-1R in principal glands were similar in control PO and SD rats. However, nutrient and chemical induced diabetes resulted in opposite alterations of glandular GLP-1R expression. Diabetic PO demonstrated increased GLP-1R mRNA expression, intensity of cellular GLP-1R immunostaining, and frequency of GLP-1R positive cells in the neck area of principal glands compared with controls. In contrast, SD diabetic rats demonstrated decreased GLP-1 mRNA, cellular GLP-1R immunoreactivity, and frequency of GLP-1R immunoreactive cells in the neck area compared with controls. In conclusion, nutrient and chemical induced experimental diabetes result in distinct opposite alterations of GLP-1R expression in glandular stomach. These results suggest that induced T1DM and T2DM may differently modulate GLP-1R system in enteropancreatic axis. Topics: Animals; Diabetes Mellitus, Experimental; Diabetes Mellitus, Type 1; Diabetes Mellitus, Type 2; Disease Models, Animal; Female; Gastric Mucosa; Gerbillinae; Glucagon-Like Peptide 1; Glucagon-Like Peptide-1 Receptor; Pancreas; Rats; Rats, Sprague-Dawley; RNA, Messenger; Streptozocin | 2015 |
[Treatment of GLP1 receptor agonists and body mass control].
The prevalence of obesity continues to be increasing in all age groups in most countries of the European Union (EU). Many obese people have a history of several successful weight losses, but very few are able to maintain the weight loss over a longer period of time. Initiation of the GLP1 RA administration during weight loss maintenance would inhibit weight loss-induced increases in soluble leptin receptor plasma concentrations resulting in higher level of free leptin thereby preventing weight regain. In contrast initiation of insulin treatment in type 2 diabetes patients is frequently accompanied with weight gain. The GLP1 administration results in HbA1c decrease accompanied with weight loss, presents attractive alternative to basal insulin. The question remains to be answered in the future, if the GLP1 RA administration is generally more frequently started in antiobese than antidiabetes implication. Topics: Body Mass Index; Diabetes Mellitus, Type 2; Glucagon-Like Peptide 1; Humans; Hypoglycemic Agents; Receptors, Glucagon; Weight Loss | 2015 |
GLP1, an Important Regulator of Intestinal Lipid Metabolism.
Topics: Animals; Central Nervous System; Diabetes Mellitus, Type 2; Glucagon-Like Peptide 1; Lipoproteins; Peptides; Receptors, Glucagon; Venoms | 2015 |
Care of type 2 diabetes: where do the new medications fit?
Topics: Diabetes Mellitus, Type 2; Glucagon-Like Peptide 1; Humans; Hypoglycemic Agents; Sodium-Glucose Transporter 2 Inhibitors | 2015 |
Pancreatic Amylase and Lipase Plasma Concentrations Are Unaffected by Increments in Endogenous GLP-1 Levels Following Liquid Meal Tests.
Topics: Amylases; Case-Control Studies; Diabetes Mellitus, Type 2; Food, Formulated; Glucagon-Like Peptide 1; Glucose Tolerance Test; Humans; Incretins; Lipase; Middle Aged; Pancreas | 2015 |
Liraglutide, a glucagon-like peptide-1 analog, increased insulin sensitivity assessed by hyperinsulinemic-euglycemic clamp examination in patients with uncontrolled type 2 diabetes mellitus.
Glucagon-like peptide-1 (GLP-1) analog promotes insulin secretion by acting on pancreatic β-cells. This antihyperglycemic treatment for type 2 diabetes mellitus (DM) has attracted increased clinical attention not only for its antihyperglycemic action but also for its potential extrapancreatic effects. We investigated whether liraglutide, a GLP-1 analog, could enhance insulin sensitivity as assessed by the hyperinsulinemic-euglycemic clamp in type 2 DM patients.. We prospectively enrolled 31 uncontrolled type 2 DM patients who were hospitalized and equally managed by guided diet- and exercise-therapies and then introduced to either liraglutide- or intensive insulin-therapy for 4 weeks. Insulin sensitivity was assessed by the glucose infusion rate (GIR) using hyperinsulinemic-euglycemic clamp before and after the therapies.. Values of HbA1c, postprandial plasma glucose, and body mass index (BMI) were significantly decreased by hospitalized intensive insulin-therapy or liraglutide-therapy. GIR was significantly increased by liraglutide-therapy but not by insulin-therapy, indicating that liraglutide-therapy significantly enhanced insulin sensitivity. BMI decreased during liraglutide-therapy but was not significantly correlated with changes in GIR. Multivariate logistic regression analysis demonstrated that liraglutide-therapy significantly correlated with increased insulin sensitivity in uncontrolled DM patients.. Liraglutide may exhibit favorable effects on diabetes control for type 2 DM patients by increasing insulin sensitivity as an extrapancreatic action. Clinical trial registration Unique Identifier is UMIN000015201. Topics: Aged; Diabetes Mellitus, Type 2; Diet; Diet Therapy; Exercise; Female; Glucagon-Like Peptide 1; Glucose; Glucose Clamp Technique; Glycated Hemoglobin; Hospitalization; Humans; Hyperinsulinism; Insulin; Insulin-Secreting Cells; Life Style; Liraglutide; Male; Middle Aged; Multivariate Analysis; Prospective Studies | 2015 |
Improvement of glycemic control in streptozotocin-induced diabetic rats by Atlantic salmon skin gelatin hydrolysate as the dipeptidyl-peptidase IV inhibitor.
In our previous study, Atlantic salmon skin gelatin hydrolysed with flavourzyme possessed 42.5% dipeptidyl-peptidase (DPP)-IV inhibitory activity at a concentration of 5 mg mL(-1). The oral administration of the hydrolysate (FSGH) at a single dose of 300 mg per day in streptozotocin (STZ)-induced diabetic rats for 5 weeks was evaluated for its antidiabetic effect. During the 5-week experiment, body weight increased, and the food and water intake was reduced by FSGH in diabetic rats. The daily administration of FSGH for 5 weeks was effective for lowering the blood glucose levels of diabetic rats during an oral glucose tolerance test (OGTT). After the 5-week treatment, plasma DPP-IV activity was inhibited; the plasma activity of glucagon-like peptide-1 (GLP-1), insulin, and the insulin-to-glucagon ratio were increased by FSGH in diabetic rats. The results indicate that FSGH has the function of inhibiting GLP-1 degradation by DPP-IV, resulting in the enhancement of insulin secretion and improvement of glycemic control in STZ-induced diabetic rats. Topics: Animals; British Columbia; Diabetes Mellitus, Type 2; Dietary Supplements; Dipeptidyl Peptidase 4; Dipeptidyl-Peptidase IV Inhibitors; Endopeptidases; Fish Proteins; Food-Processing Industry; Gelatin; Glucagon; Glucagon-Like Peptide 1; Hyperglycemia; Industrial Waste; Insulin; Insulin Secretion; Male; Protein Hydrolysates; Rats, Sprague-Dawley; Salmo salar; Skin | 2015 |
Minimizing Hypoglycemia and Weight Gain with Intensive Glucose Control: Potential Benefits of a New Combination Therapy (IDegLira).
Due to the progressive nature of type 2 diabetes (T2D), the majority of patients require increasing levels of therapy to achieve and maintain good glycemic control. At present, once patients become uncontrolled on oral antidiabetic therapies, the two primary treatment options are glucagon-like peptide-1 receptor agonists (GLP-1RAs) or basal insulin, although earlier use of GLP-1RAs has also been advocated. While both of these drug classes have proven efficacy in treating T2D, there can be limitations to their use in some patients, and resistance to further treatment intensification among both patients and physicians. More recently, treatment incorporating both a GLP-1RA and a basal insulin has been used successfully in the clinic and the first such combination product, IDegLira (insulin degludec+liraglutide), has recently been approved for use in Europe. IDegLira combines insulin degludec and the GLP-1RA liraglutide in a single injection. In both insulin-naïve and basal insulin-treated individuals with T2D, IDegLira has demonstrated greater reductions in glycated hemoglobin (HbA1c) than either of the individual components, with a low rate of hypoglycemia and weight loss. IDegLira may provide a new option for patients requiring treatment intensification but for whom increased weight or a higher risk of hypoglycemia are barriers. This article discusses the rationale behind combining these two drug classes and reviews the available clinical evidence for the efficacy and safety of IDegLira. Topics: Blood Glucose; Diabetes Mellitus, Type 2; Drug Combinations; Europe; Glucagon-Like Peptide 1; Glycated Hemoglobin; Humans; Hypoglycemia; Insulin; Insulin, Long-Acting; Liraglutide; Treatment Outcome; Weight Gain | 2015 |
Incretin-based therapies: where will we be 50 years from now?
The development of incretin-based therapies (glucagon-like peptide 1 [GLP-1] receptor agonists and dipeptidyl peptidase-4 [DPP-4] inhibitors) has changed the landscape of type 2 diabetes management over the past decade. Current developments include longer-acting GLP-1 receptor agonists, fixed-ratio combinations of GLP-1 analogues and basal insulin, as well as implantable osmotic minipumps for long-term delivery of GLP-1 receptor agonists. In longer terms, oral or inhaled GLP-1 analogues may become a reality. In addition, oral enhancers of GLP-1 secretion (e.g. via G-protein-coupled receptors, nuclear farnesoid-receptor X and the G-protein-coupled bile acid-activated receptor [TGR5]) are currently being explored in experimental studies. Combination of GLP-1 with other gut hormones (e.g. peptide YY, glucagon, gastrin, glucose-dependent insulinotropic polypeptide [GIP], secretin, cholecystokinin, vasoactive intestinal polypeptide and pituitary adenylate cyclase-activating polypeptide) may enhance the glucose- and weight-lowering effect of GLP-1 alone, and dual or triple hormone receptor agonists may even exploit the properties of different peptides with just one molecule. There is also an increasing interest in employing incretin-based therapies in other areas, such as type 1 diabetes, impaired glucose metabolism, obesity, polycystic ovary syndrome, non-alcoholic fatty liver disease (NAFLD)/non-alcoholic steatohepatitis (NASH), psoriasis or even neurodegeneration. Thus, incretin-based therapies may continue to broaden the therapeutic spectrum for type 2 diabetes and for various other indications in the coming years. This is one of a series of commentaries under the banner '50 years forward', giving personal opinions on future perspectives in diabetes, to celebrate the 50th anniversary of Diabetologia (1965-2015). Topics: Diabetes Mellitus, Type 2; Dipeptidyl-Peptidase IV Inhibitors; Glucagon-Like Peptide 1; Humans; Hypoglycemic Agents; Incretins | 2015 |
The effects of insulin and liraglutide on osteoprotegerin and vascular calcification in vitro and in patients with type 2 diabetes.
Vascular calcification (VC) is inhibited by the glycoprotein osteoprotegerin (OPG). It is unclear whether treatments for type 2 diabetes are capable of promoting or inhibiting VC. The present study examined the effects of insulin and liraglutide on i) the production of OPG and ii) the emergence of VC, both in vitro in human aortic smooth muscle cells (HASMCs) and in vivo in type 2 diabetes.. HASMCs were exposed to insulin glargine or liraglutide, after which OPG production, alkaline phosphatase (ALP) activity and levels of Runx2, ALP and bone sialoprotein (BSP) mRNA were measured. A prospective, nonrandomised human subject study was also conducted, in which OPG levels and coronary artery calcification (CAC) were measured in a type 2 diabetes population before and 16 months after the commencement of either insulin or liraglutide treatment and in a control group that took oral hypoglycemics only.. Exposure to insulin glargine, but not liraglutide, was associated with significantly decreased OPG production (11 913±1409 pg/10(4) cells vs 282±13 pg/10(4) cells, control vs 10 nmol/l insulin, P<0.0001), increased ALP activity (0.82±0.06 IU/10(4) cells vs 2.40±0.16 IU/10(4) cells, control vs 10 nmol/l insulin, P<0.0001) and increased osteogenic gene expression by HASMCs. In the clinical study (n=101), insulin treatment was associated with a significant reduction in OPG levels and, despite not achieving full statistical significance, a trend towards increased CAC in patients.. Exogenous insulin down-regulated OPG in vitro and in vivo and promoted VC in vitro. Although neither insulin nor liraglutide significantly affected CAC in the present pilot study, these data support the establishment of randomised trials to investigate medications and VC in diabetes. Topics: Aged; Alkaline Phosphatase; Cells, Cultured; Core Binding Factor Alpha 1 Subunit; Coronary Vessels; Diabetes Mellitus, Type 2; Endpoint Determination; Female; Glucagon-Like Peptide 1; Humans; Hypoglycemic Agents; In Vitro Techniques; Insulin Glargine; Insulin, Long-Acting; Liraglutide; Male; Metformin; Middle Aged; Muscle, Smooth, Vascular; Osteoprotegerin; Pilot Projects; Prospective Studies; Sialoglycoproteins; Vascular Calcification | 2015 |
Effects of exogenous glucagon-like peptide-1 on blood pressure, heart rate, gastric emptying, mesenteric blood flow and glycaemic responses to oral glucose in older individuals with normal glucose tolerance or type 2 diabetes.
A postprandial fall in BP occurs frequently in older individuals and in patients with type 2 diabetes. The magnitude of this decrease in BP is related to the rate of gastric emptying (GE). Intravenous administration of glucagon-like peptide-1 (GLP-1) attenuates the hypotensive response to intraduodenal glucose in healthy older individuals. We sought to determine the effects of exogenous GLP-1 on BP, GE, superior mesenteric artery (SMA) flow and glycaemic response to oral ingestion of glucose in healthy older individuals and patients with type 2 diabetes.. Fourteen older volunteers (six men, eight women; age 72.1 ± 1.1 years) and ten patients with type 2 diabetes (six men, four women; age 68.7 ± 3.4 years; HbA1c 6.6 ± 0.2% [48.5 ± 2.0 mmol/mol]; nine with blood glucose managed with metformin, two with a sulfonylurea and one with a dipeptidyl-peptidase 4 inhibitor) received an i.v. infusion of GLP-1 (0.9 pmol kg(-1) min(-1)) or saline (154 mmol/l NaCl) for 150 min (t = -30 min to t = 120 min) in randomised order. At t = 0 min, volunteers consumed a radiolabelled 75 g glucose drink. BP was assessed with an automated device, GE by scintigraphy and SMA flow by ultrasonography. Blood glucose and serum insulin were measured.. GLP-1 attenuated the fall in diastolic BP after the glucose drink in older individuals (p < 0.05) and attenuated the fall in systolic and diastolic BP in patients with type 2 diabetes (p < 0.05). GE was faster in patients with type 2 diabetes than in healthy individuals (p < 0.05). In both groups, individuals had slower GE (p < 0.001), decreased SMA flow (p < 0.05) and a lower degree of glycaemia (p < 0.001) when receiving GLP-1.. Intravenous GLP-1 attenuates the hypotensive response to orally administered glucose and decreases SMA flow, probably by slowing GE. GLP-1 and 'short-acting' GLP-1 agonists may be useful in the management of postprandial hypotension. Topics: Aged; Blood Pressure; Diabetes Mellitus, Type 2; Female; Gastric Emptying; Glucagon-Like Peptide 1; Glucose; Heart Rate; Humans; Hypoglycemic Agents; Insulin; Male; Mesenteric Artery, Superior; Postprandial Period; Regional Blood Flow | 2015 |
[Optimizing treatment of type 2 diabetic patients].
Topics: Administration, Oral; Diabetes Mellitus, Type 2; Drug Combinations; Germany; Glucagon-Like Peptide 1; Glycated Hemoglobin; Humans; Injections, Subcutaneous; Insulin, Long-Acting; Liraglutide; Metformin | 2015 |
Synthesis and Evaluation of a Series of Long-Acting Glucagon-Like Peptide-1 (GLP-1) Pentasaccharide Conjugates for the Treatment of Type 2 Diabetes.
The present study details the development of a family of novel D-Ala(8) glucagon-like peptide-1 (GLP-1) peptide conjugates by site specific conjugation to an antithrombin III (ATIII) binding carrier pentasaccharide through tetraethylene glycol linkers. All conjugates were found to possess potent insulin-releasing activity. Peptides with short linkers (<25 atoms) conjugated at Lys(34) and Lys(37) displayed strong GLP-1 receptor (GLP-1-R) binding affinity. All D-Ala(8) GLP-1 conjugates exhibited prominent glucose-lowering action. Biological activity of the Lys(37) short-linker peptide was evident up to 72 h post-injection. In agreement, the pharmacokinetic profile of this conjugate (t1/2 , 11 h) was superior to that of the GLP-1-R agonist, exenatide. Once-daily injection of the Lys(37) short-linker peptide in ob/ob mice for 21 days significantly decreased food intake and improved HbA1c and glucose tolerance. Islet size was decreased, with no discernible change in islet number. The beneficial effects of the Lys(37) short-linker peptide were similar to or better than either exenatide or liraglutide, another GLP-1-R agonist. In conclusion, GLP-1 peptides conjugated to an ATIII binding carrier pentasaccharide have a substantially prolonged bioactive profile compatible for possible once-weekly treatment of type 2 diabetes in humans. Topics: Animals; Antithrombin III; Area Under Curve; Blood Glucose; Diabetes Mellitus, Type 2; Drug Evaluation, Preclinical; Exenatide; Glucagon-Like Peptide 1; Glucose Tolerance Test; Glycated Hemoglobin; Half-Life; Humans; Hypoglycemic Agents; Insulin; Mice; Mice, Inbred C57BL; Mice, Obese; Oligosaccharides; Peptides; Protein Binding; Receptors, Glucagon; ROC Curve; Venoms | 2015 |
ACP Journal Club. Incretin use was not associated with increased risk for acute pancreatitis.
Topics: Diabetes Mellitus, Type 2; Dipeptidyl-Peptidase IV Inhibitors; Female; Glucagon-Like Peptide 1; Humans; Hypoglycemic Agents; Incretins; Male; Pancreatitis | 2015 |
Metabolic surgery and intestinal gene expression: Digestive tract and diabetes evolution considerations.
To investigate the effects of bariatric surgery on metabolic parameters, incretin hormone secretion, and duodenal and ileal mucosal gene expression.. Nine patients with type 2 diabetes mellitus (T2DM), chronic serum hyperglycemia for more than 2 years, and a body mass index (BMI) of 30-35 kg/m(2) underwent metabolic surgery sleeve gastrectomy with transit bipartition between May 2011 and December 2011. Blood samples were collected pre and 3, 6 and 12 mo postsurgery. Duodenal and ileal mucosa samples were collected pre- and 3 mo postsurgery. Pre- and postoperative blood samples were collected in the fasting state before ingestion of a standard meal (520 kcal) and again 30, 60, 90, and 120 min after the meal to determine hemoglobin A1c (HbA1c) levels and the lipid profile, which consisted of triglyceride and total cholesterol levels. Intestinal gene expression of p53 and transforming growth factor (TGF)-β was analyzed using quantitative reverse-transcription PCR. Gastric inhibitory polypeptide (GIP) and glucagon-like peptide-1 (GLP-1) were quantified using the enzyme-linked immunoassay method and analyzed pre- and postoperatively. Student's t test or repeated measurements analysis of variance with Bonferroni corrections were performed as appropriate.. BMI values decreased by 15.7% within the initial 3 mo after surgery (31.29 ± 0.73 vs 26.398 ± 0.68, P < 0.05) and then stabilized at 22% at 6 mo postoperative, resulting in similar values 12 mo postoperatively (20-25 kg/m(2)). All of the patients experienced improved T2DM, with 7 patients (78%) achieving complete remission (HbA1c < 6.5%), and 2 patients (22%) achieving improved diabetes (HbA1c < 7.0% with or without the use of oral hypoglycemic agents). At 3 mo postoperatively, fasting plasma glucose had also decreased (59%) (269.55 ± 18.24 mg/dL vs 100.77 ± 3.13 mg/dL, P < 0.05) with no further significant changes at 6 or 12 mo postoperatively. In the first month postoperatively, there was a complete withdrawal of hypoglycemic medications in all patients, who were taking at least 2 hypoglycemic drugs preoperatively. GLP-1 levels significantly increased after surgery (149.96 ± 31.25 vs 220.23 ± 27.55) (P < 0.05), while GIP levels decreased but not significantly. p53 gene expression significantly increased in the duodenal mucosa (P < 0.05, 2.06 fold) whereas the tumor growth factor-β gene expression significantly increased (P < 0.05, 2.52 fold) in the ileal mucosa after surgery.. Metabolic surgery ameliorated diabetes in all of the patients, accompanied by increased anti-proliferative intestinal gene expression in non-excluded segments of the intestine. Topics: Adult; Bariatric Surgery; Biomarkers; Biopsy; Blood Glucose; Body Mass Index; Cell Proliferation; Diabetes Mellitus, Type 2; Duodenum; Fasting; Female; Gastrectomy; Gastric Inhibitory Polypeptide; Gene Expression Regulation; Glucagon-Like Peptide 1; Glycated Hemoglobin; Humans; Hypoglycemic Agents; Ileum; Intestinal Mucosa; Male; Middle Aged; Obesity; Postprandial Period; Remission Induction; Time Factors; Transforming Growth Factor beta; Treatment Outcome; Tumor Suppressor Protein p53; Weight Loss | 2015 |
Intestinal Sodium Glucose Cotransporter 1 Inhibition Enhances Glucagon-Like Peptide-1 Secretion in Normal and Diabetic Rodents.
The sodium glucose cotransporter (SGLT) 1 plays a major role in glucose absorption and incretin hormone release in the gastrointestinal tract; however, the impact of SGLT1 inhibition on plasma glucagon-like peptide-1 (GLP-1) levels in vivo is controversial. We analyzed the effects of SGLT1 inhibitors on GLP-1 secretion in normoglycemic and hyperglycemic rodents using phloridzin, CGMI [3-(4-cyclopropylphenylmethyl)-1-(β-d-glucopyranosyl)-4-methylindole], and canagliflozin. These compounds are SGLT2 inhibitors with moderate SGLT1 inhibitory activity, and their IC50 values against rat SGLT1 and mouse SGLT1 were 609 and 760 nM for phloridzin, 39.4 and 41.5 nM for CGMI, and 555 and 613 nM for canagliflozin, respectively. Oral administration of these inhibitors markedly enhanced and prolonged the glucose-induced plasma active GLP-1 (aGLP-1) increase in combination treatment with sitagliptin, a dipeptidyl peptidase-4 (DPP4) inhibitor, in normoglycemic mice and rats. CGMI, the most potent SGLT1 inhibitor among them, enhanced glucose-induced, but not fat-induced, plasma aGLP-1 increase at a lower dose compared with canagliflozin. Both CGMI and canagliflozin delayed intestinal glucose absorption after oral administration in normoglycemic rats. The combined treatment of canagliflozin and a DPP4 inhibitor increased plasma aGLP-1 levels and improved glucose tolerance compared with single treatment in both 8- and 13-week-old Zucker diabetic fatty rats. These results suggest that transient inhibition of intestinal SGLT1 promotes GLP-1 secretion by delaying glucose absorption and that concomitant inhibition of intestinal SGLT1 and DPP4 is a novel therapeutic option for glycemic control in type 2 diabetes mellitus. Topics: Animals; CHO Cells; Cricetulus; Diabetes Mellitus, Experimental; Diabetes Mellitus, Type 2; Dipeptidyl Peptidase 4; Glucagon-Like Peptide 1; Glucose; Humans; Hyperglycemia; Hypoglycemic Agents; Intestinal Absorption; Intestinal Mucosa; Intestines; Male; Mice; Mice, Inbred C57BL; Rats; Rats, Sprague-Dawley; Rats, Zucker; Sodium-Glucose Transporter 1; Sodium-Glucose Transporter 2 | 2015 |
Defective Glucagon-Like Peptide 1 Secretion in Prediabetes and Type 2 Diabetes Is Influenced by Weight and Sex. Chicken, Egg, or None of the Above?
Topics: Diabetes Mellitus, Type 2; Female; Glucagon-Like Peptide 1; Humans; Male; Obesity; Prediabetic State | 2015 |
Comment on Thomsen et al. Incretin-Based Therapy and Risk of Acute Pancreatitis: A Nationwide Population-Based Case-Control Study. Diabetes Care 2015;38:1089-1098.
Topics: Diabetes Mellitus, Type 2; Dipeptidyl-Peptidase IV Inhibitors; Female; Glucagon-Like Peptide 1; Humans; Hypoglycemic Agents; Incretins; Male; Pancreatitis | 2015 |
Response to Comment on Thomsen et al. Incretin-Based Therapy and Risk of Acute Pancreatitis: A Nationwide Population-Based Case-Control Study. Diabetes Care 2015;38:1089-1098.
Topics: Diabetes Mellitus, Type 2; Dipeptidyl-Peptidase IV Inhibitors; Female; Glucagon-Like Peptide 1; Humans; Hypoglycemic Agents; Incretins; Male; Pancreatitis | 2015 |
A bitter herbal medicine Gentiana scabra root extract stimulates glucagon-like peptide-1 secretion and regulates blood glucose in db/db mouse.
Gentiana scabra root extract (GS) is frequently prescribed as an internal remedy in traditional Korean medicine for treatment of diabetes mellitus. GS contains bitter iridoid glycosides including loganic acid, gentiopicrin, trifloroside, and rindoside. We previously reported that the intestinal bitter taste sensation stimulates GLP-1 secretion, and thereupon hypothesized that the blood glucose regulatory effect of GS is due to its GLP-1 secreting effect in enteroendocrine L cells.. We studied GLP-1 secreting effect of GS treatment and its cellular downstream mechanism in human enteroendocrine NCI-H716 cells using the G protein-coupled receptor (GPCR) pathway inhibitors. Intracellular calcium assay also demonstrated the signal transduction pathway stimulated by the GS treatment. Using db/db mice, we performed oral glucose tolerance test (OGTT) to examine the blood glucose lowering effect of GS administration. We also collected the mouse plasma during the OGTT to measure the GLP-1 and insulin levels.. We demonstrated dose-dependent GLP-1 secreting effect of GS on the NCI-H716 cells. The GLP-1 secreting effect of GS is mediated by the G protein βγ-subunit and inositol triphosphate. Using db/db mice, we found that the effect of GS on lowering blood glucose is due to its GLP-1 secretion, and consequential insulinotropic effect. The chemical fingerprint of GS was obtained through a direct analysis in realtime mass spectrometry (DART-MS) and high-performance liquid chromatography (HPLC)/MS. Through the GLP-1 secretion study, we found that loganic acid, an iridoid glycoside, contributes to the GLP-1 secreting effect of GS.. The findings of this study highlight the potential of exploiting the antidiabetic effect of GS on type 2 diabetes mellitus patients. Topics: Animals; Blood Glucose; Cell Line; Chromatography, High Pressure Liquid; Diabetes Mellitus, Experimental; Diabetes Mellitus, Type 2; Enteroendocrine Cells; Gentiana; Glucagon-Like Peptide 1; Glucose Tolerance Test; Humans; Hypoglycemic Agents; Male; Mass Spectrometry; Mice; Plant Extracts; Plant Roots; Receptors, G-Protein-Coupled; Signal Transduction | 2015 |
Expression of a glucagon-like peptide-1 analogue, as a therapeutic agent for type II diabetes, with enhanced bioactivity and increased N-terminal homogeneity in Pichia pastoris.
To improve the bioactivity and increase the N-terminal homogeneity of a glucagon-like peptide-1 (GLP-1) analogue expressed in Pichia pastoris.. The GLP-1 analogue. GGH, consisting of two tandem mutant GLP-1 (GLP-1[A2G]) fused with the N-terminus of human serum albumin (HSA), was expressed in P. pastoris. We also designed and expressed the novel GLP-1 analogue NGGH, which had a His-tag fused with the N-terminus of GGH and an enterokinase (EK) cleavage site at the fusion junction. The His-tag was removed by EK digestion to yield GGH2, which was subsequently compared with GGH expressed in P. pastoris. The purification recovery of GGH2 was 35 % compared with 23 % for GGH. Furthermore, the bioactivity of GGH2 was 605 % higher than GGH, and N-terminal homogeneity was also improved.. A simple method for the preparation of GGH2 with a cleavable His-tag was developed, and the resultant protein possessed improved bioactivity and N-terminal homogeneity. Topics: Diabetes Mellitus, Type 2; Fermentation; Glucagon-Like Peptide 1; Humans; Hypoglycemic Agents; Pichia; Recombinant Proteins | 2015 |
Albiglutide for treating type 2 diabetes: an evaluation of pharmacokinetics/pharmacodynamics and clinical efficacy.
Albiglutide is a once-weekly, glucagon-like peptide-1 receptor agonist approved during 2014 in both the US and Europe for the treatment of adults with type 2 diabetes. The recommended dose is 30 mg with the possibility of uptitration to 50 mg based on individual glycemic response.. Here, we outline the pharmacokinetics, pharmacodynamics and clinical efficacy data originating from the Phase I - III studies carried out to obtain market authorization for albiglutide.. The eight Phase III clinical trials have provided evidence that albiglutide in monotherapy and as an add-on to different background therapies confers placebo-corrected reductions in glycemia with changes in glycated hemoglobin of -0.8 to -1.0%. Albiglutide did not cause significant weight loss compared to placebo, but the adverse events profile was favorable with gastrointestinal adverse events occurring only slightly more with albiglutide than placebo. There is no clinical evidence of an effect of albiglutide on major cardiovascular outcomes. Topics: Adult; Clinical Trials, Phase I as Topic; Clinical Trials, Phase II as Topic; Clinical Trials, Phase III as Topic; Diabetes Mellitus, Type 2; Dose-Response Relationship, Drug; Glucagon-Like Peptide 1; Glucagon-Like Peptide-1 Receptor; Humans; Hypoglycemic Agents; Weight Loss | 2015 |
Ileal Interposition in Rats with Experimental Type 2 Like Diabetes Improves Glycemic Control Independently of Glucose Absorption.
Bariatric operations in obese patients with type 2 diabetes often improve diabetes before weight loss is observed. In patients mainly Roux-en-Y-gastric bypass with partial stomach resection is performed. Duodenojejunal bypass (DJB) and ileal interposition (IIP) are employed in animal experiments. Due to increased glucose exposition of L-cells located in distal ileum, all bariatric surgery procedures lead to higher secretion of antidiabetic glucagon like peptide-1 (GLP-1) after glucose gavage. After DJB also downregulation of Na(+)-d-glucose cotransporter SGLT1 was observed. This suggested a direct contribution of decreased glucose absorption to the antidiabetic effect of bariatric surgery. To investigate whether glucose absorption is also decreased after IIP, we induced diabetes with decreased glucose tolerance and insulin sensitivity in male rats and investigated effects of IIP on diabetes and SGLT1. After IIP, we observed weight-independent improvement of glucose tolerance, increased insulin sensitivity, and increased plasma GLP-1 after glucose gavage. The interposed ileum was increased in diameter and showed increased length of villi, hyperplasia of the epithelial layer, and increased number of L-cells. The amount of SGLT1-mediated glucose uptake in interposed ileum was increased 2-fold reaching the same level as in jejunum. Thus, improvement of glycemic control by bariatric surgery does not require decreased glucose absorption. Topics: Animals; Bariatric Surgery; Blood Glucose; Diabetes Mellitus, Type 2; Enteroendocrine Cells; Glucagon-Like Peptide 1; Glucose; Hyperglycemia; Hyperplasia; Hypoglycemia; Ileum; Insulin Resistance; Intestinal Absorption; Male; Microvilli; Obesity; Rats, Inbred Lew; Sodium-Glucose Transporter 1; Specific Pathogen-Free Organisms | 2015 |
Effect of Roux-en-Y gastric bypass on the distribution and hormone expression of small-intestinal enteroendocrine cells in obese patients with type 2 diabetes.
We studied the impact of Roux-en-Y gastric bypass (RYGB) on the density and hormonal gene expression of small-intestinal enteroendocrine cells in obese patients with type 2 diabetes.. Twelve patients with diabetes and 11 age- and BMI-matched controls underwent RYGB followed by enteroscopy ~10 months later. Mucosal biopsies taken during surgery and enteroscopy were immunohistochemically stained for glucagon-like peptide-1 (GLP-1), peptide YY (PYY), cholecystokinin (CCK), glucose-dependent insulinotropic polypeptide (GIP) and prohormone convertase 2 (PC2) and the expression of GCG (encoding preproglucagon), PYY, CCK, GIP, GHRL (encoding ghrelin), SCT (encoding secretin), NTS (encoding neurotensin) and NR1H4 (encoding farnesoid X receptor) was evaluated.. The density of cells immunoreactive for GLP-1, CCK and GIP increased in patients after RYGB and the density of those immunoreactive for GLP-1, PYY, CCK and PC2 increased in controls. In both groups, GHRL, SCT and GIP mRNA was reduced after RYGB while PYY, CCK, NTS and NR1H4 gene expression was unaltered. GCG mRNA was upregulated in both groups.. Numerous alterations in the distribution of enteroendocrine cells and their expression of hormonal genes are seen after RYGB and include increased density of GLP-1-, PYY-, CCK-, GIP- and PC2-positive cells, reduced gene expression of GHRL, SCT and GIP and increased expression of GCG. Topics: Adult; Cholecystokinin; Diabetes Mellitus, Type 2; Enteroendocrine Cells; Female; Gastric Bypass; Gastric Inhibitory Polypeptide; Ghrelin; Glucagon-Like Peptide 1; Humans; Male; Middle Aged; Obesity, Morbid; Peptide YY; Proprotein Convertase 2; Treatment Outcome | 2015 |
A Novel TGR5 Activator WB403 Promotes GLP-1 Secretion and Preserves Pancreatic β-Cells in Type 2 Diabetic Mice.
The G protein-coupled receptor TGR5 is a membrane receptor for bile acids. Its agonism increases energy expenditure and controls blood glucose through secretion of glucagon-like peptide-1 in enteroendocrine cells. In this study, we explored the therapeutic potential of WB403, a small compound activating TGR5 which was identified by combining TGR5 targeted luciferase assay and active GLP-1 assay, in treating type 2 diabetes. After confirmation of TGR5 and GLP-1 stimulating activities in various cell systems, WB403 was examined in oral glucose tolerance test, and tested on different mouse models of type 2 diabetes for glycemic control and pancreatic β-cell protection effect. As a result, WB403 exhibited a moderate TGR5 activation effect while promoting GLP-1 secretion efficiently. Interestingly, gallbladder filling effect, which was reported for some known TGR5 agonists, was not detected in this novel compound. In vivo results showed that WB403 significantly improved glucose tolerance and decreased fasting blood glucose, postprandial blood glucose and HbA1c in type 2 diabetic mice. Further analysis revealed that WB403 increased pancreatic β-cells and restored the normal distribution pattern of α-cell and β-cell in islets. These findings demonstrated that TGR5 activator WB403 effectively promoted GLP-1 release, improved hyperglycemia and preserved the mass and function of pancreatic β-cells, whereas it did not show a significant side effect on gallbladder. It may represent a promising approach for future type 2 diabetes mellitus drug development. Topics: Animals; Blood Glucose; Diabetes Mellitus, Experimental; Diabetes Mellitus, Type 2; Glucagon; Glucagon-Like Peptide 1; Glucose Intolerance; Glucose Tolerance Test; Insulin-Secreting Cells; Mice; Postprandial Period; Receptors, G-Protein-Coupled | 2015 |
Induction of miR-132 and miR-212 Expression by Glucagon-Like Peptide 1 (GLP-1) in Rodent and Human Pancreatic β-Cells.
Better understanding how glucagon-like peptide 1 (GLP-1) promotes pancreatic β-cell function and/or mass may uncover new treatment for type 2 diabetes. In this study, we investigated the potential involvement of microRNAs (miRNAs) in the effect of GLP-1 on glucose-stimulated insulin secretion. miRNA levels in INS-1 cells and isolated rodent and human islets treated with GLP-1 in vitro and in vivo (with osmotic pumps) were measured by real-time quantitative PCR. The role of miRNAs on insulin secretion was studied by transfecting INS-1 cells with either precursors or antisense inhibitors of miRNAs. Among the 250 miRNAs surveyed, miR-132 and miR-212 were significantly up-regulated by GLP-1 by greater than 2-fold in INS-1 832/3 cells, which were subsequently reproduced in freshly isolated rat, mouse, and human islets, as well as the islets from GLP-1 infusion in vivo in mice. The inductions of miR-132 and miR-212 by GLP-1 were correlated with cAMP production and were blocked by the protein kinase A inhibitor H-89 but not affected by the exchange protein activated by cAMP activator 8-pCPT-2'-O-Me-cAMP-AM. GLP-1 failed to increase miR-132 or miR-212 expression levels in the 832/13 line of INS-1 cells, which lacks robust cAMP and insulin responses to GLP-1 treatment. Overexpression of miR-132 or miR-212 significantly enhanced glucose-stimulated insulin secretion in both 832/3 and 832/13 cells, and restored insulin responses to GLP-1 in INS-1 832/13 cells. GLP-1 increases the expression of miRNAs 132 and 212 via a cAMP/protein kinase A-dependent pathway in pancreatic β-cells. Overexpression of miR-132 or miR-212 enhances glucose and GLP-1-stimulated insulin secretion. Topics: Animals; Cell Line, Tumor; Cyclic AMP; Cyclic AMP-Dependent Protein Kinases; Diabetes Mellitus, Type 2; Glucagon-Like Peptide 1; Glucose; Humans; Insulin; Insulin Secretion; Insulin-Secreting Cells; Isoquinolines; Mice; Mice, Inbred C57BL; MicroRNAs; Protein Kinase Inhibitors; Rats; Rats, Sprague-Dawley; Sulfonamides | 2015 |
Mechanisms through which a small protein and lipid preload improves glucose tolerance.
Small protein or lipid preloads are able to improve glucose tolerance to a different extent and through different and poorly defined mechanisms. We aimed at quantifying the effect of a mixed protein and lipid preload and at evaluating the underlying mechanisms.. Volunteers with normal (NGT, n = 12) or impaired (IGT, n = 13) glucose tolerance and patients with type 2 diabetes (n = 10) underwent two OGTTs coupled to the double glucose tracer protocol, preceded by either 50 g of parmesan cheese, a boiled egg and 300 ml of water, or 500 ml of water. We measured plasma glucose, insulin, C-peptide, glucagon-like peptide-1 (GLP-1), glucose-dependent insulinotropic polypeptide (GIP), pancreatic polypeptide (PP), NEFA and glucose tracers, and calculated glucose fluxes, beta cell function variables, insulin sensitivity and clearance.. After the nutrient preload, the OGTT-induced rise of plasma glucose was lower than after water alone in each study group. This reduction—more pronounced across classes of glucose tolerance (NGT -32%, IGT -37%, type 2 diabetes -49%; p < 0.002)—was the result of different combinations of slower exogenous glucose rate of appearance, improved beta cell function and reduced insulin clearance, in this order of relevance, which were associated with an only mild stimulation of GIP and GLP-1.. After a non-glucidic nutrient preload, glucose tolerance improved in proportion to the degree of its baseline deterioration through mechanisms that appear particularly effective in type 2 diabetes. Exploiting the physiological responses to nutrient ingestion might reveal, at least in the first stages of the diabetic disease, a potent tool to improve daily life glycaemic control.. ClinicalTrials.gov NCT02342834 FUNDING: This work was supported by grants from the University of Pisa (Fondi di Ateneo) and by FCT grant (PIC/IC/82956/2007). Topics: Adolescent; Adult; Aged; Blood Glucose; C-Peptide; Diabetes Mellitus, Type 2; Dietary Fats; Dietary Proteins; Female; Glucagon-Like Peptide 1; Glucose Intolerance; Glucose Tolerance Test; Humans; Insulin; Male; Middle Aged; Young Adult | 2015 |
Transfer of liraglutide from blood to cerebrospinal fluid is minimal in patients with type 2 diabetes.
Treatment with liraglutide leads to weight loss. We investigated whether blood-to-cerebrospinal fluid (CSF) transfer of liraglutide occurs, and if so, whether it associates with clinical weight loss following liraglutide treatment in humans. We performed lumbar puncture and blood sampling in eight patients with type 2 diabetes (mean (range)): age 63 (54-79) years; actual body weight: 90 (75-118) kg treated with 1.8 mg liraglutide for 14 (5-22) months and with a treatment-induced weight loss of 8.4 (7-11) kg. We measured liraglutide in plasma and CSF with a radioimmunoassay specific for the N-terminus of the GLP-1 moiety of liraglutide. Mean plasma liraglutide was 31 (range: 21-63) nmol l(-1). The mean CSF-liraglutide concentration was 6.5 (range: 0.9-13.9) pmol l(-1). Ratio of CSF: plasma-liraglutide concentrations was 0.02 (range: 0.07-0.002)% and plasma liraglutide did not correlate with CSF-liraglutide levels (P=0.67). Body weight loss tended to correlate with plasma-liraglutide levels (P=0.06), but not with CSF-liraglutide levels (P=0.69). In conclusion, we measured very low concentrations of liraglutide in CSF, and the levels of CSF liraglutide did not correlate with the actual clinical weight loss in these patients. The amount of liraglutide in plasma tended to correlate with the clinical weight loss. Topics: Aged; Anti-Obesity Agents; Biomarkers; Blood-Brain Barrier; Body Weight; Diabetes Mellitus, Type 2; Female; Glucagon-Like Peptide 1; Humans; Liraglutide; Male; Middle Aged; Treatment Outcome | 2015 |
A Comparative Study of the Effect of Gastric Bypass, Sleeve Gastrectomy, and Duodenal-Jejunal Bypass on Type-2 Diabetes in non-Obese Rats.
We compared the therapeutic effects of Roux-en-Y gastric bypass (RYGB), sleeve gastrectomy (SG), and duodenal-jejunal bypass (DJB) on type-2 diabetes mellitus (T2DM) in non-obese rats using clamp testing.. Goto-Kakizaki rats (non-obese rats with T2DM) underwent surgery: RYGB, SG, or DJB. Rats were observed for 8 weeks after surgery to evaluate weight changes. Levels of glucose, insulin, and glucagon-like peptide (GLP)-1 were determined 2, 4, 6, and 8 weeks after surgery. An oral glucose tolerance test (OGTT) and clamp test was used to evaluate glucose tolerance and insulin resistance.. Rats in RYGB, SG, and DJB groups weighed significantly less than sham-group rats 6 and 8 weeks after surgery. Fasting blood glucose levels of RYGB, SG, and DJB rats were significantly lower than preoperative levels. One month after surgery, the area under the curve of the OGTT (in mmol•h/L) for RYGB, SG, DJB, and sham surgery groups was 38.9 ± 5.9, 50.9 ± 2.9, 46.8 ± 3.3, and 67.4 ± 6.0, respectively; there was no significant difference in glucose levels of SG and DJB groups. Glucose infusion rates (in mg/(kg•min)) were 18.3 ± 2.7, 17.2 ± 2.1, and 16.8 ± 1.9 in hyperinsulinemic-euglycemic-clamped RYGB, DJB, and SG rats, respectively, 8 weeks after surgery. The rate in the sham surgery group was 6.3 ± 0.9. Area under plasma insulin curves 8 weeks after surgery in hyperglycemic-clamped RYGB, DJB, SG, and sham surgery rats (in mU•h/L) were 98.8 ± 7.0, 84.4 ± 6.1, 89.0 ± 7.1, and 22.6 ± 2.6, respectively.. The three surgical methods described alleviated T2DM and reduced insulin resistance in non-obese rats with T2DM. Topics: Animals; Bariatric Surgery; Blood Glucose; Diabetes Mellitus, Type 2; Duodenum; Gastrectomy; Gastric Bypass; Glucagon-Like Peptide 1; Glucose Clamp Technique; Insulin; Insulin Resistance; Jejunum; Male; Rats; Rats, Inbred Strains | 2015 |
Cardiovascular safety of albiglutide and other glucagon-like peptide-1 receptor agonists.
Topics: Cardiovascular System; Diabetes Mellitus, Type 2; Female; Glucagon-Like Peptide 1; Humans; Incretins; Male | 2015 |
Comment on Færch et al. GLP-1 Response to Oral Glucose Is Reduced in Prediabetes, Screen-Detected Type 2 Diabetes, and Obesity and Influenced by Sex: The ADDITION-PRO Study. Diabetes 2015;64:2513-2525.
Topics: Diabetes Mellitus, Type 2; Female; Glucagon-Like Peptide 1; Humans; Male; Obesity; Prediabetic State | 2015 |
SGLT-2 INHIBITOR THERAPY ADDED TO GLP-1 AGONIST THERAPY IN THE MANAGEMENT OF T2DM.
To assess the real-world efficacy and safety of canagliflozin therapy added to type 2 diabetes mellitus (T2DM) patients who have received a minimum 1 year of glucagon-like peptide-1 (GLP-1) agonist therapy.. This pre-post observational study assessed the efficacy and safety of canagliflozin in a group of T2DM patients from a community endocrinology practice who received GLP-1 agonist therapy for a minimum of 12 months. The primary study outcome was change in mean glycated hemoglobin (HbA1c) level from baseline. Secondary endpoints included changes in average weight, and comparison of the percentage of patients obtaining an HbA1c <7%.. A total of 75 patients met all the study criteria. Baseline patient characteristics were as follows: average age, 58 ± 9 years; mean duration of T2DM, 14 ± 6 years; 56% male; 92% Caucasian; baseline body mass index (BMI), 39.4 ± 9.4 kg/m(2); and mean baseline HbA1c, 7.94 ± 0.69%. HbA1c and weight were significantly reduced by 0.39% and 4.6 kg, respectively. Adverse effects were reported by 13 (17.3%) patients, including 4 (5.3%) who discontinued canagliflozin because of adverse reactions.. Canagliflozin was generally well tolerated and significantly further reduced mean HbA1c levels and body weight in patients with T2DM when added to GLP-1 regimen. Topics: Adult; Aged; Blood Glucose; Body Weight; Canagliflozin; Diabetes Mellitus, Type 2; Drug Therapy, Combination; Female; Follow-Up Studies; Glucagon-Like Peptide 1; Glycated Hemoglobin; Humans; Hypoglycemic Agents; Male; Middle Aged; Sodium-Glucose Transporter 2; Sodium-Glucose Transporter 2 Inhibitors; Treatment Outcome | 2015 |
A new angle for glp-1 receptor agonist: the medical economics argument. Editorial on: Huetson P, Palmer JL, Levorsen A, et al. Cost-effectiveness of the once-daily glp-1 receptor agonist lixisenatide compared to bolus insulin both in combination with basa
Glucagon-like peptide-1 receptor agonists (GLP-1 RA) are relatively new medications for diabetes that offer a weight-loss profile that can be considered desirable for patients with both type 2 diabetes (T2D) and obesity. GLP-1 RA are effective in combination with insulin, and even slightly superior or at least equal to short-acting insulin in T2D; however, since they work in the incretin system, they may not be effective in long-standing disease. Additionally, only recently have publications reported their cardiovascular safety, and there is limited evidence for long-term effectiveness. The work presented by Huetson et al. offers a much needed perspective through a medical economic model for the long term cost-effectiveness of GLP-1 RA. The authors found benefits in quality-adjusted life years and reduced lifetime healthcare costs. While there are a few limitations, this study contributes to the understanding of these agents and their impact on the epidemics of obesity in T2D, where weight management is no longer an option, but an essential component of the diabetes plan of care. Topics: Cost-Benefit Analysis; Diabetes Mellitus, Type 2; Economics, Medical; Glucagon-Like Peptide 1; Glucagon-Like Peptide-1 Receptor; Humans; Hypoglycemic Agents; Insulin; Receptors, Glucagon | 2015 |
Effects of E2HSA, a Long-Acting Glucagon Like Peptide-1 Receptor Agonist, on Glycemic Control and Beta Cell Function in Spontaneous Diabetic db/db Mice.
Glucagon like peptide-1 (GLP-1) receptor agonists such as exendin-4 have been widely used but their short half-life limits their therapeutic value. The recombinant protein, E2HSA, is a novel, long-acting GLP-1 receptor agonist generated by the fusion of exendin-4 with human serum albumin. In mouse pancreatic NIT-1 cells, E2HSA activated GLP-1 receptor with similar efficacy as exendin-4. After single-dose administration in ICR mice, E2HSA showed prolonged glucose lowering effects which lasted up to four days and extended inhibition on gastric emptying for at least 72 hours. Chronic E2HSA treatment in db/db mice significantly improved glucose tolerance, reduced elevated nonfasting and fasting plasma glucose levels, and also decreased HbA1c levels. E2HSA also increased insulin secretion and decreased body weight and appetite. Furthermore, immunofluorescence analysis showed that E2HSA increased β-cell area, improved islet morphology, and reduced β-cell apoptosis. In accordance with the promotion of β-cell function and survival, E2HSA upregulated genes such as Irs2, Pdx-1, Nkx6.1, and MafA and downregulated the expression levels of FoxO1 and proapoptotic Bcl-2 family proteins. In conclusion, with prolonged glucose lowering effects and promoting β-cell function and survival, the fusion protein, E2HSA, is a promising new therapeutic for once weekly treatment of type 2 diabetes. Topics: Animals; Apoptosis; Blood Glucose; Body Weight; Diabetes Mellitus, Type 2; Exenatide; Female; Gastric Emptying; Glucagon-Like Peptide 1; Glucagon-Like Peptide-1 Receptor; Glucose; Glucose Tolerance Test; Humans; Insulin; Insulin Secretion; Insulin-Secreting Cells; Male; Mice; Mice, Inbred ICR; Microscopy, Fluorescence; Pancreas; Peptides; Recombinant Fusion Proteins; Serum Albumin; Serum Albumin, Human; Venoms | 2015 |
[Basal insulin and liraglutide combined in a pen].
Topics: Diabetes Mellitus, Type 2; Drug Combinations; Glucagon-Like Peptide 1; Humans; Hypoglycemic Agents; Injections, Subcutaneous; Insulin; Liraglutide | 2015 |
[Dulaglutide and liraglutide compared].
Topics: Diabetes Mellitus, Type 2; Glucagon-Like Peptide 1; Glucagon-Like Peptides; Humans; Hypoglycemic Agents; Immunoglobulin Fc Fragments; Liraglutide; Recombinant Fusion Proteins | 2015 |
Endogenous GLP-1 mediates postprandial reductions in activation in central reward and satiety areas in patients with type 2 diabetes.
The central nervous system (CNS) is a major player in the regulation of food intake. The gut hormone glucagon-like peptide-1 (GLP-1) has been proposed to have an important role in this regulation by relaying information about nutritional status to the CNS. We hypothesised that endogenous GLP-1 has effects on CNS reward and satiety circuits.. This was a randomised, crossover, placebo-controlled intervention study, performed in a university medical centre in the Netherlands. We included patients with type 2 diabetes and healthy lean control subjects. Individuals were eligible if they were 40-65 years. Inclusion criteria for the healthy lean individuals included a BMI <25 kg/m(2) and normoglycaemia. Inclusion criteria for the patients with type 2 diabetes included BMI >26 kg/m(2), HbA1c levels between 42 and 69 mmol/mol (6.0-8.5%) and treatment for diabetes with only oral glucose-lowering agents. We assessed CNS activation, defined as blood oxygen level dependent (BOLD) signal, in response to food pictures in obese patients with type 2 diabetes (n = 20) and healthy lean individuals (n = 20) using functional magnetic resonance imaging (fMRI). fMRI was performed in the fasted state and after meal intake on two occasions, once during infusion of the GLP-1 receptor antagonist exendin 9-39, which was administered to block actions of endogenous GLP-1, and on the other occasion during saline (placebo) infusion. Participants were blinded for the type of infusion. The order of infusion was determined by block randomisation. The primary outcome was the difference in BOLD signal, i.e. in CNS activation, in predefined regions in the CNS in response to viewing food pictures.. All patients were included in the analyses. Patients with type 2 diabetes showed increased CNS activation in CNS areas involved in the regulation of feeding (insula, amygdala and orbitofrontal cortex) in response to food pictures compared with lean individuals (p ≤ 0.04). Meal intake reduced activation in the insula in response to food pictures in both groups (p ≤ 0.05), but this was more pronounced in patients with type 2 diabetes. Blocking actions of endogenous GLP-1 significantly prevented meal-induced reductions in bilateral insula activation in response to food pictures in patients with type 2 diabetes (p ≤ 0.03).. Our findings support the hypothesis that endogenous GLP-1 is involved in postprandial satiating effects in the CNS of obese patients with type 2 diabetes.. ClinicalTrials.gov NCT 01363609. Funding The study was funded in part by a grant from Novo Nordisk. Topics: Adult; Aged; Cross-Over Studies; Diabetes Mellitus, Type 2; Female; Food; Glucagon-Like Peptide 1; Glucagon-Like Peptide-1 Receptor; Glycated Hemoglobin; Humans; Magnetic Resonance Imaging; Male; Middle Aged; Obesity; Oxygen; Peptide Fragments; Photic Stimulation; Postprandial Period; Reward; Satiety Response | 2015 |
Immunohistochemical, apoptotic and biochemical changes by dipeptidyl peptidase-4 inhibitor-sitagliptin in type-2 diabetic rats.
Diabetes is a major public health problem that is rapidly increasing in prevalence. In this study, the effects of sitagliptin, a dipeptidyl peptidase-4 inhibitor, were examined on newborn diabetic rat model.. Wistar albino newborn rats were divided into control (Ctrl), sitagliptin (Sit), diabetic and diabetic+Sit groups. On the second day after the birth, 100mg/kg streptozotocin (STZ) was administered intraperitoneally in a single dose to induce type-2 diabetes in rats. The Sit and diabetic+Sit groups were administered sitagliptin (1.5mg/kg subcutaneous) as of the day 5 for 15 days. The pancreas sections were stained with insulin (INS), glucagon (GLU), somatostatin (SS), glucagon-like peptide-1 (GLP-1) and glucagon-like peptide-1 receptor (GLP-1R) antibodies by the streptavidin-biotin peroxidase technique. The TUNEL method for apoptosis and biochemical analysis were performed in the pancreas and serum, respectively.. Body weight and blood glucose levels showed significant differences among all groups on days 11 and 20. In diabetic rats following treatment with sitagliptin, the area percentage of INS immunopositive cells increased while the area percentage of SS immunopositive cells decreased, insignificantly. A significant increase was observed on the area percentage of GLU, GLP-1 and GLP-1R immunopositive cells in the diabetic+Sit group when compared to the diabetic group. The area percentage of apoptotic cells was the same among all groups. While serum glutathione and malondialdehyde levels demonstrated insignificant alterations, the catalase and superoxide dismutase activity significantly changed among four groups.. According to our findings, sitagliptin may be a useful therapeutic agent to a certain extent of type-2 diabetic condition. Topics: Animals; Animals, Newborn; Apoptosis; Blood Glucose; Body Weight; Diabetes Mellitus, Experimental; Diabetes Mellitus, Type 2; Dipeptidyl-Peptidase IV Inhibitors; Glucagon; Glucagon-Like Peptide 1; Islets of Langerhans; Rats; Rats, Wistar; Sitagliptin Phosphate; Somatostatin | 2015 |
Yhhu4488, a novel GPR40 agonist, promotes GLP-1 secretion and exerts anti-diabetic effect in rodent models.
G protein-coupled receptor 40 (GPR40) is predominantly expressed in pancreatic β-cells and activated by long-chain fatty acids. GPR40 has drawn considerable interest as a potential therapeutic target for type 2 diabetes mellitus (T2DM) due to its important role in enhancing glucose-stimulated insulin secretion (GSIS). Encouragingly, GPR40 is also proven to be highly expressed in glucagon-like peptide-1 (GLP-1)-producing enteroendocrine cells afterwards, which opens a potential role of GPR40 in enhancing GLP-1 secretion to exert additional anti-diabetic efficacy. In the present study, we discovered a novel GPR40 agonist, yhhu4488, which is structurally different from other reported GPR40 agonists. Yhhu4488 showed potent agonist activity with EC50 of 49.96 nM, 70.83 nM and 58.68 nM in HEK293 cells stably expressing human, rat and mouse GPR40, respectively. Yhhu4488 stimulated GLP-1 secretion from fetal rat intestinal cells (FRIC) via triggering endogenous calcium store mobilization and extracellular calcium influx. The effect of yhhu4488 on GLP-1 secretion was further confirmed in type 2 diabetic db/db mice. Yhhu4488 exhibited satisfactory potency in in vivo studies. Single administration of yhhu4488 improved glucose tolerance in SD rats. Chronic administration of yhhu4488 effectively decreased fasting blood glucose level, improved β-cell function and lipid homeostasis in type 2 diabetic ob/ob mice. Taken together, yhhu4488 is a novel GPR40 agonist that enhances GLP-1 secretion, improves metabolic control and β-cell function, suggesting its promising potential for the treatment of type 2 diabetes. Topics: Animals; Diabetes Mellitus, Type 2; Female; Glucagon-Like Peptide 1; Glucose Tolerance Test; Humans; Hypoglycemic Agents; Insulin-Secreting Cells; Male; Mice; Mice, Mutant Strains; Phenylpropionates; Pregnancy; Pyridines; Rats; Rats, Sprague-Dawley; Receptors, G-Protein-Coupled | 2015 |
Effectiveness and Persistence with Liraglutide Among Patients with Type 2 Diabetes in Routine Clinical Practice--EVIDENCE: A Prospective, 2-Year Follow-Up, Observational, Post-Marketing Study.
The aim of this study was to investigate whether the efficacy of liraglutide observed in randomized controlled trials translates into therapeutic benefits in the French population during routine clinical practice.. This observational, prospective, multicenter study included 3152 adults with type 2 diabetes who had recently started or were about to start liraglutide treatment. During 2 years of follow-up, an evaluation of the reasons for prescribing liraglutide, maintenance dose of liraglutide, changes in combined antidiabetic treatments, level of glycemic control, change in body weight and body mass index (BMI), patient satisfaction with diabetes treatment and safety of liraglutide were investigated. The primary study endpoint was the proportion of patients still receiving liraglutide and presenting with HbA1c <7.0% after 2 years of follow-up.. At the end of the study, 29.5% of patients maintained liraglutide treatment and reached the HbA(1c) target. Mean (±SD) HbA(1c), fasting plasma glucose concentration, body weight and BMI were significantly reduced from baseline [8.46% (±1.46) to 7.44% (±1.20); 180 (±60) to 146 (±44) mg/dL; 95.2 (±20.0) to 91.1 (±19.6) kg; 34.0 (±7.2) to 32.5 (±6.9) kg/m(2); respectively, all P < 0.0001]. Patient treatment satisfaction increased, with the mean diabetes treatment satisfaction questionnaire status version score increasing from 22.17 (±7.64) to 28.55 (±5.79), P < 0.0001. The main adverse event type was gastrointestinal, with a frequency of 10.9%, and the percentage of patients suffering ≥1 hypoglycemic episode decreased from 6.9% to 4.4%.. The results of the EVIDENCE study suggest that the effectiveness of liraglutide in real-world clinical practice is similar to that observed in randomized controlled trials.. Novo Nordisk A/S.. ClinicalTrials.gov identifier, NCT01226966. Topics: Aged; Blood Glucose; Body Mass Index; Body Weight; Diabetes Mellitus, Type 2; Female; Glucagon-Like Peptide 1; Glycated Hemoglobin; Humans; Hypoglycemia; Hypoglycemic Agents; Liraglutide; Male; Medication Adherence; Middle Aged; Product Surveillance, Postmarketing; Prospective Studies | 2015 |
Serum Levels of Soluble CD26/Dipeptidyl Peptidase-IV in Type 2 Diabetes Mellitus and Its Association with Metabolic Syndrome and Therapy with Antidiabetic Agents in Malaysian Subjects.
A soluble form of CD26/dipeptidyl peptidase-IV (sCD26/DPP-IV) induces DPP-IV enzymatic activity that degrades incretin. We investigated fasting serum levels of sCD26/DPP-IV and active glucagon-like peptide-1 (GLP-1) in Malaysian patients with type 2 diabetes mellitus (T2DM) with and without metabolic syndrome (MetS), as well as the associations between sCD26/DPP-IV levels, MetS, and antidiabetic therapy.. We assessed sCD26/DPP-IV levels, active GLP-1 levels, body mass index (BMI), glucose, insulin, A1c, glucose homeostasis indices, and lipid profiles in 549 Malaysian subjects (including 257 T2DM patients with MetS, 57 T2DM patients without MetS, 71 non-diabetics with MetS, and 164 control subjects without diabetes or metabolic syndrome).. Fasting serum levels of sCD26/DPP-IV were significantly higher in T2DM patients with and without MetS than in normal subjects. Likewise, sCD26/DPP-IV levels were significantly higher in patients with T2DM and MetS than in non-diabetic patients with MetS. However, active GLP-1 levels were significantly lower in T2DM patients both with and without MetS than in normal subjects. In T2DM subjects, sCD26/DPP-IV levels were associated with significantly higher A1c levels, but were significantly lower in patients using monotherapy with metformin. In addition, no significant differences in sCD26/DPP-IV levels were found between diabetic subjects with and without MetS. Furthermore, sCD26/DPP-IV levels were negatively correlated with active GLP-1 levels in T2DM patients both with and without MetS. In normal subjects, sCD26/DPP-IV levels were associated with increased BMI, cholesterol, and LDL-cholesterol (LDL-c) levels.. Serum sCD26/DPP-IV levels increased in T2DM subjects with and without MetS. Active GLP-1 levels decreased in T2DM patients both with and without MetS. In addition, sCD26/DPP-IV levels were associated with Alc levels and negatively correlated with active GLP-1 levels. Moreover, metformin monotherapy was associated with reduced sCD26/DPP-IV levels. In normal subjects, sCD26/DPP-IV levels were associated with increased BMI, cholesterol, and LDL-c. Topics: Case-Control Studies; Diabetes Mellitus, Type 2; Dipeptidyl Peptidase 4; Fasting; Female; Glucagon-Like Peptide 1; Glycated Hemoglobin; Humans; Hypoglycemic Agents; Malaysia; Male; Metabolic Syndrome; Metformin; Middle Aged; Solubility | 2015 |
SGLT-2 INHIBITION ADDED TO GLP-1 AGONIST THERAPY FOR TYPE 2 DIABETES: WHAT IS THE BENEFIT?
Topics: Canagliflozin; Diabetes Mellitus, Type 2; Female; Glucagon-Like Peptide 1; Humans; Hypoglycemic Agents; Male; Sodium-Glucose Transporter 2 Inhibitors | 2015 |
Localization of dipeptidyl peptidase-4 (CD26) to human pancreatic ducts and islet alpha cells.
DPP-4/CD26 degrades the incretins GLP-1 and GIP. The localization of DPP-4 within the human pancreas is not well documented but is likely to be relevant for understanding incretin function. We aimed to define the cellular localization of DPP-4 in the human pancreas from cadaveric organ donors with and without diabetes.. Pancreas was snap-frozen and immunoreactive DPP-4 detected in cryosections using the APAAP technique. For co-localization studies, pancreas sections were double-stained for DPP-4 and proinsulin or glucagon and scanned by confocal microscopy. Pancreata were digested and cells in islets and in islet-depleted, duct-enriched digests analyzed for expression of DPP-4 and other markers by flow cytometry.. DPP-4 was expressed by pancreatic duct and islet cells. In pancreata from donors without diabetes or with type 2 diabetes, DPP-4-positive cells in islets had the same location and morphology as glucagon-positive cells, and the expression of DPP-4 and glucagon overlapped. In donors with type 1 diabetes, the majority of residual cells in islets were DPP-4-positive.. In the human pancreas, DPP-4 expression is localized to duct and alpha cells. This finding is consistent with the view that DPP-4 regulates exposure to incretins of duct cells directly and of beta cells indirectly in a paracrine manner. Topics: Adult; Aged; Diabetes Mellitus, Type 2; Dipeptidyl Peptidase 4; Female; Glucagon; Glucagon-Like Peptide 1; Glucagon-Secreting Cells; Humans; Immunohistochemistry; Incretins; Insulin-Secreting Cells; Male; Middle Aged; Pancreatic Ducts; Proinsulin; Young Adult | 2015 |
Functions of Cholesterol Metabolites.
Cholesterol is a major component of membrane lipids. Thus, adjusting the membrane cholesterol composition is essential for maintaining cellular homeostasis. Cholesterol biosynthesis and uptake by LDL receptors are tightly regulated at the transcriptional level through negative feedback control, which is mediated by sterol regulatory element-binding proteins (SREBPs). In particular, SREBP-2 is activated in a cholesterol-dependent manner and, thus, is significantly involved in regulating the expression of those genes associated with cholesterol metabolism. Cholesterol metabolites such as oxysterols are involved in regulating sterol metabolism by binding to the nuclear receptor, liver X receptor (LXR). Cholesterol catabolites, i.e., bile acids, are agonists for another nuclear receptor, farnesoid X receptor (FXR), and a bile acid receptor, TGR5. Activated FXR regulates bile acid metabolism and TGR5 improves glucose metabolism through the actions of glucagon-like peptide-1 (GLP-1). Topics: Bile Acids and Salts; Blood Glucose; Cell Membrane; Cholesterol; Diabetes Mellitus, Type 2; Gene Expression Regulation; Glucagon-Like Peptide 1; Humans; Lipid Metabolism; Liver X Receptors; Obesity; Orphan Nuclear Receptors; Receptors, Cytoplasmic and Nuclear; Receptors, G-Protein-Coupled; Receptors, LDL; Sterol Regulatory Element Binding Protein 2 | 2015 |
An association between liraglutide treatment and reduction in excessive daytime sleepiness in obese subjects with type 2 diabetes.
The main purpose of the present study is to evaluate whether treatment with long-acting human glucagon-like peptide-1 liraglutide was associated with an improvement of excessive daytime sleepiness (EDS) in obese subjects with type-2 diabetes.. This single-centre retrospective study included 158 obese (body mass index [BMI] ≥ 30 kg/m(2)) adult subjects with type-2 diabetes who were initiated with liraglutide treatment at least 3 months before study inclusion. Data of the Epworth Sleepiness Scale (ESS), anthropometric parameters, glucose-control and metabolic parameters were collected at liraglutide initiation (baseline) and at months 1 and 3 after liraglutide initiation.. Significant reductions in ESS score were achieved at months 1 (-1.3 ± 2.8, p < 0.001) and 3 (-1.5 ± 3.0, p < 0.001) after liraglutide introduction. After 3 months of treatment with liraglutide, significant changes in body weight (p < 0.001), BMI (p < 0.001), waist (p < 0.001) and neck circumferences (p < 0.005), HbA1c (p < 0.001), mean blood glucose (p < 0.001), fasting plasma glucose (p < 0.001), triglycerides (p < 0.01) and total cholesterol (p < 0.001) were achieved.. After 3 months of treatment with liraglutide a significant reduction in EDS was observed in obese subjects with type-2 diabetes. Besides this, significant changes in body weight and metabolic parameters of diabetes control were also accomplished. Further investigation is required to determine whether liraglutide could improve other abnormal sleep patterns and obstructive sleep apnoea. Topics: Blood Glucose; Body Mass Index; Cholesterol; Diabetes Mellitus, Type 2; Disorders of Excessive Somnolence; Female; Glucagon-Like Peptide 1; Glycated Hemoglobin; Humans; Hypoglycemic Agents; Liraglutide; Male; Middle Aged; Obesity; Retrospective Studies; Spain; Treatment Outcome | 2015 |
Variant fatty acid-like molecules Conjugation, novel approaches for extending the stability of therapeutic peptides.
The multiple physiological properties of glucagon-like peptide-1 (GLP-1) make it a promising drug candidate for the treatment of type 2 diabetes. However, the in vivo half-life of GLP-1 is short due to rapid degradation by dipeptidyl peptidase-IV (DPP-IV) and renal clearance. The poor stability of GLP-1 has significantly limited its clinical utility; however, many studies are focused on extending its stability. Fatty acid conjugation is a traditional approach for extending the stability of therapeutic peptides because of the high binding affinity of human serum albumin for fatty acids. However, the conjugate requires a complex synthetic approach, usually involving Lys and occasionally involving a linker. In the current study, we conjugated the GLP-1 molecule with fatty acid derivatives to simplify the synthesis steps. Human serum albumin binding assays indicated that the retained carboxyl groups of the fatty acids helped maintain a tight affinity to HSA. The conjugation of fatty acid-like molecules improved the stability and increased the binding affinity of GLP-1 to HSA. The use of fatty acid-like molecules as conjugating components allowed variant conjugation positions and freed carboxyl groups for other potential uses. This may be a novel, long-acting strategy for the development of therapeutic peptides. Topics: Animals; Diabetes Mellitus, Type 2; Dipeptidyl Peptidase 4; Fatty Acids; Glucagon-Like Peptide 1; Half-Life; Humans; Male; Mice; Peptides; Protein Precursors; Rats; Serum Albumin | 2015 |
The aglycone of ginsenoside Rg3 enables glucagon-like peptide-1 secretion in enteroendocrine cells and alleviates hyperglycemia in type 2 diabetic mice.
Ginsenosides can be classified on the basis of the skeleton of their aglycones. Here, we hypothesized that the sugar moieties attached to the dammarane backbone enable binding of the ginsenosides to the sweet taste receptor, eliciting glucagon-like peptide-1 (GLP-1) secretion in the enteroendocrine L cells. Using the human enteroendocrine NCI-H716 cells, we demonstrated that 15 ginsenosides stimulate GLP-1 secretion according to the position of their sugar moieties. Through a pharmacological approach and RNA interference technique to inhibit the cellular signal cascade and using the Gαgust(-/-) mice, we elucidated that GLP-1 secreting effect of Rg3 mediated by the sweet taste receptor mediated the signaling pathway. Rg3, a ginsenoside metabolite that transformed the structure through a steaming process, showed the strongest GLP-1 secreting effects in NCI-H716 cells and also showed an anti-hyperglycemic effect on a type 2 diabetic mouse model through increased plasma GLP-1 and plasma insulin levels during an oral glucose tolerance test. Our study reveals a novel mechanism where the sugar moieties of ginsenosides Rg3 stimulates GLP-1 secretion in enteroendocrine L cells through a sweet taste receptor-mediated signal transduction pathway and thus has an anti-hyperglycemic effect on the type 2 diabetic mouse model. Topics: Animals; Cell Line, Tumor; Diabetes Mellitus, Type 2; Enteroendocrine Cells; Enzyme-Linked Immunosorbent Assay; Gene Expression; Ginsenosides; Glucagon-Like Peptide 1; Glucose Tolerance Test; Humans; Hyperglycemia; Immunoblotting; Mice, Inbred C57BL; Mice, Knockout; Receptors, G-Protein-Coupled; Reverse Transcriptase Polymerase Chain Reaction; RNA Interference; Transducin | 2015 |
GLP-1 RAs as compared to prandial insulin after failure of basal insulin in type 2 diabetes: lessons from the 4B and Get-Goal DUO 2 trials.
The add-on of a prandial (short-acting) GLP-1 RA to basal insulin in subjects with T2DM who fail to control A1C on basal insulin, stems from the physiological principles of post-prandial glucose homeostasis, and it is based on evidence from clinical trials. The 4B and GetGoal DUO 2 studies are the first to establish in head-to-head comparison, the efficacy and safety of short-acting GLP-1 RAs vs prandial insulin, when added-on to basal insulin glargine. In the 4B study (exenatide 2/d vs lispro 3/d) exenatide demonstrated similar efficacy vs lispro in reducing A1C to ~7.2%. However, exenatide reduced also body weight and hypoglycemia incidence as compared to lispro. In GetGoal DUO 2, the head-to-head comparison was between lixisenatide 1/d vs glulisine either 1/d (at the main meal, basal-plus) or 3/d (basal-bolus). Like in 4B, in GetGoal DUO 2 the A1C decreased to similar values with lixisenatide or glulisine 1/d (~7.2%), or glulisine 3/d (~7.0%). Again, as in the 4B, body weight and hypoglycemia incidence were lower with lixisenatide. In both studies a similar percentage of subjects reached the A1C <7.0% on GLP-1 RA or prandial insulin. A higher percentage of subjects reported adverse events on GLP-1 RAs, primarily gastrointestinal related. The studies 4B and GetGoal DUO 2 suggest that after failure of basal insulin in T2DM, the add-on of prandial GLP-1 RA is as effective as prandial insulin in lowering A1C, with added benefits of reducing body weight and risk for hypoglycemia. In addition, the GLP-1 RA + basal insulin is a simpler therapeutic option as compared to basal-plus and basal-bolus regimens. Topics: Blood Glucose; Diabetes Mellitus, Type 2; Drug Administration Schedule; Drug Therapy, Combination; Exenatide; Glucagon-Like Peptide 1; Humans; Hypoglycemic Agents; Insulin; Insulin Glargine; Patient Care Planning; Peptides; Postprandial Period; Randomized Controlled Trials as Topic; Venoms | 2015 |
Physiological aspects of the combination of insulin and GLP-1 in the regulation of blood glucose control.
Combining insulin with glucagon-like peptide-1 (GLP-1) receptor agonists or dipeptidyl peptidase-4 (DPP-4) inhibitors as glucose-lowering therapy for type 2 diabetes is a promising strategy that has gained considerable interest over the past few years. One advantage of this combination is the complementary mechanistic actions of insulin and GLP-1. Insulin increases glucose utilization and retards hepatic glucose production through direct actions in muscle, adipose tissue and the liver. On the other hand, GLP-1 stimulates insulin secretion, inhibits glucagon secretion and retards gastric emptying. Combining these effects results in powerful reductions in both fasting and postprandial glucose through diminished glucose entry into the bloodstream after food consumption, reduced hepatic production of glucose and increased glucose utilization. In addition, GLP-1 receptor agonists induce satiety, leading to decreases in food intakes and body weight, thereby preventing the weight gain often seen with insulin therapy. Clinical trials have verified that these physiological effects as a result of combining insulin with GLP-1 receptor agonists or DPP-4 inhibitors can indeed result in improved glycaemia, with limited risks of hypoglycaemia and weight gain. Topics: Blood Glucose; Diabetes Mellitus, Type 2; Dipeptidyl-Peptidase IV Inhibitors; Drug Therapy, Combination; Fasting; Glucagon-Like Peptide 1; Humans; Hypoglycemic Agents; Incretins; Insulin | 2015 |
Mechanism of bile acid-regulated glucose and lipid metabolism in duodenal-jejunal bypass.
Bile acid plays an important role in regulating blood glucose, lipid and energy metabolism. The present study was implemented to determine the effect of duodenal-jejunal bypass (DJB) on FXR, TGR-5expression in terminal ileum and its bile acid-related mechanism on glucose and lipid metabolism. Immunohistochemistry was used to detect relative gene or protein expression in liver and intestine. Firstly, we found that expression of FXR in liver and terminal ileum of DJB group was significantly higher than that in S-DJB group (P<0.05). In addition, DJB dramatically increased the activation of TGR-5 in the liver of rats. Furthermore, PEPCK, G6Pase, FBPase 1 and GLP-1 were up-regulated by DJB. In conclusion, these results showed that bile acid ameliorated glucose and lipid metabolism through bile acid-FXR and bile acid- TGR-5 signaling pathway. Topics: Anastomosis, Surgical; Animals; Bile Acids and Salts; Diabetes Mellitus, Type 2; Disease Models, Animal; Duodenum; Fructose-Bisphosphatase; Glucagon-Like Peptide 1; Glucose; Glucose-6-Phosphatase; Ileum; Intracellular Signaling Peptides and Proteins; Jejunum; Lipid Metabolism; Liver; Phosphoenolpyruvate Carboxykinase (GTP); Rats, Sprague-Dawley; Receptors, Cytoplasmic and Nuclear; Receptors, G-Protein-Coupled | 2015 |
Beta cell specific probing with fluorescent exendin-4 is progressively reduced in type 2 diabetic mouse models.
Probes based on GLP-1R agonist exendin-4 have shown promise as in vivo β cell tracers. However, questions remain regarding the β cell specificity of exendin-4 probes, and it is unclear if the expression levels of the GLP-1R are affected in a type 2 diabetic state. Using in vivo probing followed by ex vivo imaging we found fluorescent exendin-4 probes to distinctly label the pancreatic islets in mice in a Glp-1r dependent manner. Furthermore, a co-localization study revealed a near 100 percent β cell specificity with less than one percent probing in other analyzed cell types. We then tested if probing was affected in models of type 2 diabetes using the Lepr(db/db) (db/db) and the Diet-Induced Obese (DIO) mouse. Although nearly all β cells continued to be probed, we observed a progressive decline in probing intensity in both models with the most dramatic reduction seen in db/db mice. This was paralleled by a progressive decrease in Glp-1r protein expression levels. These data confirm β cell specificity for exendin-4 based probes in mice. Furthermore, they also suggest that GLP-1R targeting probes may provide a tool to monitor β cell function rather than mass in type 2 diabetic mouse models. Topics: Animals; Diabetes Mellitus, Experimental; Diabetes Mellitus, Type 2; Disease Progression; Exenatide; Glucagon-Like Peptide 1; Hypoglycemic Agents; Insulin-Secreting Cells; Islets of Langerhans; Mice; Mice, Obese; Peptides; Receptors, Glucagon; Venoms | 2015 |
The incretin effect in Korean subjects with normal glucose tolerance or type 2 diabetes.
The incretin effect is known to be decreased in type 2 diabetes. However, there are limited data on the incretin effect in non-Caucasian subjects. Because Asian patients with type 2 diabetes are characterized by decreased insulin secretion, this study set out to examine the incretin effect in Korean subjects with normal glucose tolerance (NGT) or type 2 diabetes.. We performed 75-g oral glucose tolerance tests (OGTTs) and corresponding isoglycaemic intravenous glucose infusion (IIGI) studies in Korean subjects with NGT (n = 14) or type 2 diabetes (n = 16). The incretin effect was calculated based on the incremental area under the curves (iAUCs) of the plasma levels of insulin, C-peptide or insulin secretion rate (ISR). The plasma levels of total glucagon-like peptide-1 (GLP-1) and glucose-dependent insulinotropic polypeptide (GIP) were measured by ELISA.. The incretin effect was not different between the subjects with NGT and type 2 diabetes (43 ± 6% vs 47 ± 4%, P = 0·575 by insulin; 29 ± 7% vs 38 ± 4%, P = 0·253 by C-peptide; 28 ± 7% vs 35 ± 5%, P = 0·372 by ISR, respectively). However, the gastrointestinally mediated glucose disposal (GIGD) was markedly decreased in type 2 diabetes (28·5 ± 4·2% vs 59·0 ± 4·3%, P < 0·001). The plasma levels of the total GLP-1 and GIP during the OGTTs were comparable between the two groups.. In Koreans, the secretion of GLP-1 or GIP during OGTTs and the incretin effect were comparable between subjects with NGT and type 2 diabetes, whereas the GIGD was significantly decreased in patients with type 2 diabetes. Topics: Adult; Asian People; Blood Glucose; C-Peptide; Diabetes Mellitus, Type 2; Gastric Inhibitory Polypeptide; Glucagon; Glucagon-Like Peptide 1; Glucose Tolerance Test; Humans; Incretins; Insulin; Insulin Secretion; Male; Middle Aged; Republic of Korea | 2014 |
Surgical control of obesity and diabetes: the role of intestinal vs. gastric mechanisms in the regulation of body weight and glucose homeostasis.
To elucidate the specific role of gastric vs. intestinal manipulations in the regulation of body weight and glucose homeostasis.. The effects of intestinal bypass alone (duodenal-jejunal bypass -DJB) and gastric resection alone (SG) in Zucker Diabetic Fatty (ZDF) rats were compared. Additional animals underwent a combination procedure (SG + DJB). Outcome measures included changes in weight, food intake (FI), oral glucose tolerance (GT) and gut hormones.. DJB did not substantially affect weight and FI, whereas SG significantly reduced weight gain and food consumption. DJB rats showed weight-independent improvement in GT, which improved less after SG. Furthermore, SG significantly suppressed plasma ghrelin and increased insulin, glucagon like peptide-1 (GLP-1), glucose-dependent insulinotropic peptide and peptide YY response to oral glucose whereas DJB had no effects on postprandial levels of these hormones. DJB restored postprandial glucagon suppression in diabetic rats whereas SG did not affect glucagon response. The combination procedure (SG + DJB) induced greater weight loss and better GT than SG alone without reducing food intake further.. These findings reveal a dominant role of the stomach in the regulation of body weight and incretin response to oral glucose whereas intestinal bypass primarily affects glucose homeostasis by a weight-, insulin- and incretin-independent mechanism. Topics: Animals; Blood Glucose; Body Weight; Diabetes Mellitus, Experimental; Diabetes Mellitus, Type 2; Duodenum; Gastrectomy; Gastric Inhibitory Polypeptide; Ghrelin; Glucagon-Like Peptide 1; Glucose Tolerance Test; Homeostasis; Insulin; Jejunoileal Bypass; Jejunum; Male; Obesity; Peptide YY; Postoperative Care; Rats | 2014 |
GLP-1 and peptide YY secretory response after fat load is impaired by insulin resistance, impaired fasting glucose and type 2 diabetes in morbidly obese subjects.
Both glucagon-like peptide-1 (GLP-1) and peptide YY (PYY) are gut hormones involved in energy homoeostasis. Obesity, insulin resistance and hyperglycaemia are significant confounders when GLP-1 and PYY secretion is assessed. Thus, we evaluated GLP-1 and PYY response after fat load in morbidly obese patients with different degrees of insulin resistance and glycemic status.. We studied 40 morbidly obese subjects (mean age, 40·6 ± 1·3 years; mean BMI, 53·1 ± 1·2 kg/m(2) ) divided into groups according to their glycemic status: normal fasting glucose (NFG) group, impaired fasting glucose (IFG) group and type 2 diabetes mellitus (T2D) group. NFG patients were additionally subclassified, according to the homoeostasis model assessment of insulin resistance (HOMAIR ), into a low insulin-resistance (LIR) group (HOMAIR <3·9) or a high insulin-resistance (HIR) group (HOMAIR ≥3·9).. Lipid emulsion was administered orally and measurements made at baseline and 180 min postprandially of levels of GLP-1, PYY, insulin, glucose, free fatty acids, triglycerides and leptin.. At the 180-minute postprandial reading, GLP-1 and PYY had increased in LIR-NFG subjects (41·84%, P = 0·01; 35·7%, P = 0·05; respectively), whereas no changes were observed in HIR-NFG, IFG or T2D subjects.. These results suggest that in morbidly obese subjects, both insulin resistance and abnormal glucose metabolism (IFG or T2D) impair the GLP-1 and PYY response to fat load. The implications of this attenuated enteroendocrine response should be elucidated by further studies. Topics: Adult; Blood Glucose; Body Mass Index; Diabetes Mellitus, Type 2; Fasting; Female; Glucagon-Like Peptide 1; Homeostasis; Humans; Insulin Resistance; Lipids; Male; Middle Aged; Obesity, Morbid; Peptide YY | 2014 |
Fructooligosaccharide augments benefits of quercetin-3-O-β-glucoside on insulin sensitivity and plasma total cholesterol with promotion of flavonoid absorption in sucrose-fed rats.
The aim was to investigate both individual and synergistic effects of quercetin-3-O-β-glucoside (Q3G) and fructooligosaccharide (FOS) on indices of metabolic syndrome and plasma total cholesterol level with potential mechanisms of action.. Five groups of rats were fed a dextrin-based diet as the normal reference group, or sucrose-based (S) diets with 0.3% Q3G, 5% FOS, or 0.3% Q3G + 5% FOS (Q3G + FOS) for 48 days. Oral glucose tolerance tests (OGTTs) were conducted on days 0, 14, 28, and 45, and adipose tissue and aortic blood were collected on day 48. Effects of Q3G and FOS on portal GLP-1 secretion were separately examined using rats after ileal administration.. Abdominal fat weight reduced in FOS-fed groups. Blood glucose levels of the Q3G + FOS group at 60 min in OGTT and HOMA-IR (0.25 ± 0.03 vs 0.83 ± 0.12 on day 45) were clearly lower in the Q3G + FOS group than in S group throughout the experimental period. Muscle Akt phosphorylation was enhanced only in the Q3G group. The plasma quercetin was largely increased by FOS feeding on day 48 (18.37 ± 1.20 with FOS, 2.02 ± 0.30 without FOS). Plasma total cholesterol levels in the Q3G + FOS group (3.10 ± 0.12, P < 0.05 on day 45) were clearly suppressed compared to the S group (4.03 ± 0.18). GLP-1 secretion was enhanced in Q3G + FOS group than in Q3G or FOS group.. Q3G + FOS diet improved glucose tolerance, insulin sensitivity, and total cholesterol level with increasing GLP-1 secretion and a higher level of blood quercetin. Q3G + FOS may reduce the risk of T2DM. Topics: Absorption; Animals; Blood Glucose; Body Weight; Cecum; Cholesterol; Diabetes Mellitus, Type 2; Diet; Flavonoids; Fructose; Glucagon-Like Peptide 1; Glucose Tolerance Test; Hydrogen-Ion Concentration; Insulin Resistance; Male; Oligosaccharides; Phosphorylation; Proto-Oncogene Proteins c-akt; Quercetin; Rats; Rats, Wistar; Sucrose | 2014 |
Effects of duodeno-jejunal bypass on glucose metabolism in obese rats with type 2 diabetes.
To evaluate the foregut and hindgut hypotheses for metabolic surgery in obese rats with diabetes.. Otsuka Long-Evans Tokushima fatty rats were divided into a sham operation group, a partial duodeno-jejunal bypass (P-DJB) group, and a complete DJB (C-DJB) group. P-DJB is a model to test foregut hypothesis, whereas C-DJB is a model to test both hypotheses. We performed oral glucose tolerance tests (OGTT) on all groups at baseline, and then 4 and 8 weeks postoperatively. The rats were killed thereafter and the plasma levels of glucagon-like peptide-1 (GLP-1) and peptide YY (PYY) were measured. A separate sub-group of C-DJB rats underwent OGTT after treatment with the GLP-1 antagonist, the PYY antagonist, or saline.. Marked improvement of the blood glucose control during the OGTT was noted 8 weeks after C-DJB, but not 8 weeks after P-DJB or the sham operation. The serum GLP-1 and PYY levels were higher in the C-DJB group than in the other two groups. Pretreatment with the GLP-1 antagonist increased the blood glucose levels 30 min after the OGTT in the C-DJB rats.. Improvement in glucose metabolism after DJB was associated with the inflow of bile and pancreatic juice into the ileum, supporting validity of the hindgut hypothesis. GLP-1 appears to play a role in this improvement. Topics: Animals; Bariatric Surgery; Bile; Blood Glucose; Diabetes Mellitus, Type 2; Duodenum; Glucagon-Like Peptide 1; Glucose; Glucose Tolerance Test; Ileum; Jejunum; Male; Obesity; Pancreatic Juice; Peptide YY; Rats; Rats, Inbred OLETF | 2014 |
Novel GPR119 agonist HD0471042 attenuated type 2 diabetes mellitus.
In type 2 diabetes mellitus (T2DM) patients, the gradual loss of pancreatic β-cell function is a characteristic feature of disease progression that is associated with sustained hyperglycemia. Recently, G protein-coupled receptor 119 (GPR119) has been identified as a promising anti-diabetic therapeutic target. It is predominantly expressed in pancreatic β-cells, directly promotes glucose stimulated insulin secretion and indirectly increases glucagon-like peptide 1 (GLP-1) levels reducing appetite and food intake. Activation of GPR119 leads to insulin release in β-cells by increasing intracellular cAMP. Here, we identified a novel structural class of small-molecule GPR119 agonists, HD0471042, consisting of substituted a 3-isopropyl-1,2,4-oxadiazol-piperidine derivative with promising potential for the treatment of T2DM. The GPR119 agonist, HD0471042 increased intracellular cAMP levels in stably human GPR119 expressing CHO cell lines and HIT-T15 cell lines, hamster β-cell line expressing endogenously GPR119. HD0471042, significantly elevated insulin release in INS-1 cells of rat pancreatic β-cell line. In in vivo experiments, a single dose of HD0471042 improved glucose tolerance. Insulin and GLP-1 level were increased in a dose-dependent manner. Treatment with HD0471042 for 6 weeks in diet induced obesity mice and for 4 weeks in ob/ob and db/db mice improved glycemic control and also reduced weight gain in a dose-dependent manner. These data demonstrate that the novel GPR119 agonist, HD0471042, not only effectively controlled glucose levels, but also had an anti-obesity effect, a feature observed with GLP-1. We therefore suggest that HD0471042 represents a new type of anti-diabetes agent with anti-obesity potential for the effective treatment of type 2 diabetes. Topics: Animals; Anti-Obesity Agents; Blood Glucose; CHO Cells; Cricetulus; Cyclic AMP; Diabetes Mellitus, Type 2; Disease Models, Animal; Dose-Response Relationship, Drug; Drug Design; Glucagon-Like Peptide 1; Humans; Hypoglycemic Agents; Insulin; Insulin-Secreting Cells; Male; Mice, Inbred C57BL; Obesity; Oxadiazoles; Piperidines; Rats; Receptors, G-Protein-Coupled; Structure-Activity Relationship; Time Factors; Transfection; Weight Gain | 2014 |
Lower glycemic fluctuations early after bariatric surgery partially explained by caloric restriction.
We assessed the acute impact of laparoscopic Roux-en-Y gastric bypass (GBP) or sleeve gastrectomy (SG) compared to caloric-matched control group without surgery on glucose excursion in obese patients with type 2 diabetes, and examined if this was mediated by changes in insulin resistance, early insulin response or glucagon-like peptide (GLP)-1 levels.. Six-day subcutaneous continuous glucose monitoring (CGM) recordings were obtained from patients beginning 3 days before GBP (n = 11), SG (n = 10) or fasting in control group (n = 10). GLP-1, insulin and glucose were measured during 75 g oral glucose tolerance testing at the start and end of each CGM.. Post-operative hyperglycaemia occurred after both surgeries in the first 6 h, with a more rapid decline in glycaemia after GBP (p < 0.001). Beyond 24 h post-operatively, continuous overlapping of net glycaemia action reduced from baseline after GBP (median [interquartile range]) 1.6 [1.2-2.4] to 1.0 [0.7-1.3] and after SG 1.4 [0.9-1.8] to 0.7 [0.7-1.0]; p < 0.05), similar to controls (2.2 [1.7-2.5] to 1.3 [0.8-2.8] p < 0.05). Higher log GLP-1 increment post-oral glucose occurred after GBP (mean ± SE, 0.80 ± 0.12 vs. 0.37 ± 0.09, p < 0.05), but not after SG or control intervention. Among subgroup with baseline hyperglycaemia, a reduction in HOMA-IR followed GBP. Reduction in time and level of peak glucose and 2-h glucose occurred after both surgeries but not in controls.. GBP and SG have a similar acute impact on reducing glycaemia to caloric restriction; however, with a superior impact on glucose tolerance. Topics: Adult; Bariatric Surgery; Blood Glucose; Caloric Restriction; Diabetes Mellitus, Type 2; Female; Gastrectomy; Gastric Bypass; Glucagon-Like Peptide 1; Glucose Intolerance; Glucose Tolerance Test; Humans; Hyperglycemia; Insulin; Insulin Resistance; Laparoscopy; Male; Middle Aged; Obesity, Morbid | 2014 |
Epigenomic approach in understanding Alzheimer's disease and type 2 diabetes mellitus.
Cognitive decline is a debilitating feature of Alzheimer's disease (AD). The causes leading to such impairment are still poorly understood and effective treatments for AD are still unavailable. Type 2 diabetes mellitus (T2DM) has been identified as a risk factor for AD due to desensitisation of insulin receptors in the brain. Recent studies have suggested that epigenetic mechanisms may also play a pivotal role in the pathogenesis of both AD and T2DM. This article describes the correlation between AD and T2DM and provides the insights to the epigenetics of AD. Currently, more research is needed to clarify the exact role of epigenetic regulation in the course and development of AD and also in relation to insulin. Research conducted especially in the earlier stages of the disease could provide more insight into its underlying pathophysiology to help in early diagnosis and the development of more effective treatment strategies. Topics: Alzheimer Disease; Animals; Diabetes Mellitus, Type 2; DNA Methylation; Epigenesis, Genetic; Epigenomics; Gene Expression; Glucagon-Like Peptide 1; Humans; Insulin | 2014 |
The better effect of Roux-en-Y gastrointestinal reconstruction on blood glucose of nonobese type 2 diabetes mellitus patients.
Given the role of gastrointestinal reconstruction, we investigated whether Roux-en-Y gastrointestinal reconstruction (RYGR) and Billroth I reconstruction (B1R) can improve glucose in nonobese type 2 diabetes mellitus patients.. Seventy-six nonobese type 2 diabetes mellitus patients underwent open subtotal gastrectomy with RYGR and B1R between January 2005 and January 2010 in our hospital. Besides demographic data, preoperative weight, glucose, hemoglobin A1c, ghrelin, and glucagon-like peptide 1 were determined.. As defined previously, 2 of 35 patients with RYGR were cured, 5 patients were controlled, and 10 patients were improved; similarly, 2 of 41 patients with B1R were controlled, and 3 patients improved 12 months after surgery. The fasting glucose and hemoglobin A1c decreased more significantly in RYGR patients (P < .05). Moreover, a higher fasting plasma GLP-1 level in RYGR patients and lower ghrelin in B1R patients were noted after surgery (P < .05).. RYGR shows a more effective amelioration in nonobese type 2 diabetes mellitus patients. Topics: Anastomosis, Roux-en-Y; Blood Glucose; Diabetes Mellitus, Type 2; Enzyme-Linked Immunosorbent Assay; Female; Gastrectomy; Gastroenterostomy; Ghrelin; Glucagon-Like Peptide 1; Glycated Hemoglobin; Humans; Length of Stay; Male; Middle Aged; Retrospective Studies; Treatment Outcome | 2014 |
Calcium/calmodulin-dependent serine protein kinase is involved in exendin-4-induced insulin secretion in INS-1 cells.
Exendin-4 (Ex-4) is an anti-diabetic drug that is a potent agonist of the glucagon-like peptide-1 (GLP-1) receptor. It has already been approved for the treatment of type 2 diabetes mellitus, but its underlying mechanisms of action are not fully understood. Calcium/calmodulin-dependent serine protein kinase (CASK), which plays a vital role in the transport and release of neurotransmitters in neurons, is expressed in pancreatic islet cells and β-cells. This study aimed to investigate whether CASK is involved in the insulin secretagogue action induced by Ex-4 in INS-1 cells.. A glucose-stimulated insulin secretion (GSIS) assay was performed with or without siRNA treatment against CASK. The expression level and location of CASK were evaluated by real-time PCR, western blotting and immunofluorescence. With the use of a protein kinase A (PKA) inhibitor or an exchange protein directly activated by cAMP-2 (Epac2) agonist, immunoblotting was performed to establish the signaling pathway through which Ex-4 alters CASK expression.. Knock-down of CASK significantly attenuated the Ex-4-enhanced insulin release, and we showed that Ex-4 could increase transcription of CASK mRNA and expression of CASK protein but did not change the cellular location of CASK. A PKA inhibitor reduced the ability of Ex-4 to stimulate CASK expression, but an Epac2 agonist had no effect suggesting that regulation was mediated by the cAMP/PKA pathway.. Our study suggests that the stimulation of β-cell insulin secretion by Ex-4 is mediated, at least in part, by CASK via a novel signaling mechanism. Topics: Animals; Blotting, Western; Cell Line, Tumor; Cyclic AMP-Dependent Protein Kinases; Diabetes Mellitus, Type 2; Exenatide; Gene Knockdown Techniques; Glucagon-Like Peptide 1; Guanylate Kinases; Hypoglycemic Agents; Insulin; Insulin Secretion; Insulinoma; Microscopy, Fluorescence; Pancreatic Neoplasms; Peptides; Rats; Real-Time Polymerase Chain Reaction; RNA, Small Interfering; Signal Transduction; Venoms | 2014 |
Use of exenatide and liraglutide in Denmark: a drug utilization study.
The purpose of this study was to characterise the utilization of the glucagon-like peptide-1 (GLP-1) analogues exenatide and liraglutide in Denmark.. From the Danish National Prescription Registry, we extracted all prescriptions for either liraglutide or exenatide twice-daily in the period 1 April 2007 to 31 December 2012. Using descriptive statistics, we calculated incidence rates, prevalence proportions, daily consumption, and concomitant drug use. For a subset of users we included data from other registries and characterised the baseline characteristics of incident users of GLP-1 analogues.. We identified 21,561 and 2,354 users of liraglutide and exenatide respectively. From market entry in 2009 liraglutide showed an increasing prevalence reaching 2.4 per thousand inhabitants in 2012. Exenatide ranged between 0.01 and 0.25 per thousand inhabitants from 2007 to 2012. Treatment intensity showed geographical variation ranging from 1.84per thousand inhabitants to 3.22 per thousand inhabitants for liraglutide. Average doses were 1.34 mg/day (liraglutide) and 16.4 μg/day (exenatide). Treatment initiation was most often performed by a hospital physician and was not associated with any changes in concomitant treatment with antihypertensives, cholesterol-lowering drugs or anticoagulants. Of liraglutide and exenatide users, 38 % and 43 % also used insulin. Low kidney function (eGFR < 30 ml/min) was found in 10.1 % and 9.0 % of users of liraglutide and exenatide respectively.. The preferred GLP-1 analogue in Denmark is liraglutide. Certain aspects of the utilization of GLP-1 analogues, such as large regional differences and concomitant use of GLP-1 analogues and insulin, warrant further investigation. Topics: Adult; Aged; Aged, 80 and over; Databases, Factual; Denmark; Diabetes Mellitus, Type 2; Drug Utilization; Exenatide; Female; Glucagon-Like Peptide 1; Humans; Hypoglycemic Agents; Liraglutide; Male; Middle Aged; Peptides; Venoms; Young Adult | 2014 |
GLP-1 receptor agonist-induced polyarthritis: a case report.
Occasional cases of bilateral, symmetrical, seronegative polyarthritis have been reported in patients treated with dipeptidyl peptidase-4 inhibitors (Crickx et al. in Rheumatol Int, 2013). We report here a similar case observed during treatment with a GLP-1 receptor agonist. A 42-year-old man with type 2 diabetes treated with metformin 1,500 mg/day and liraglutide 1.8 mg/day. After 6 months from the beginning of treatment, the patient complained of bilateral arthralgia (hands, feet, ankles, knees, and hips). Erythrocyte sedimentation rate (ESR), C-reactive protein (CRP), and leukocytes were increased. Rheumatoid factor, anticyclic citrullinated protein antibody, antinuclear antibodies, anti-Borrelia, and burgdorferi antibodies were all negative, and myoglobin and calcitonin were normal. Liraglutide was withdrawn, and the symptoms completely disappeared within 1 week, with normalization of ESR, CRP, fibrinogen, and leukocytes. Previously described cases of polyarthritis associated with DPP4 inhibitors had been attributed to a direct effect of the drugs on inflammatory cells expressing the enzyme. The present case, occurred during treatment with a GLP-1 receptor agonists, suggests a possibly different mechanism, mediated by GLP-1 receptor stimulation, which deserved further investigation. Topics: Adult; Arthritis; Diabetes Mellitus, Type 2; Glucagon-Like Peptide 1; Glucagon-Like Peptide-1 Receptor; Humans; Hypoglycemic Agents; Liraglutide; Male; Receptors, Glucagon | 2014 |
Effects of chronic exposure of clonal β-cells to elevated glucose and free fatty acids on incretin receptor gene expression and secretory responses to GIP and GLP-1.
The incretin effect, mediated by glucose-dependent insulinotropic polypeptide (GIP) and glucagon-like peptide-1 (GLP-1), is impaired in type 2 diabetes.. This study examines the effects of prolonged exposure to elevated glucose and free fatty acids in clonal BRIN BD11 cells on GIP and GLP-1 action.. Glucotoxic conditions (18 h) had no effect on GIP- or GLP-1-mediated insulinotropic responses. In contrast, 48 h glucotoxic culture impaired (p < 0.05 to p < 0.001) insulin release in response to GLP-1, and particularly GIP. Culture under lipotoxic conditions (18 h) impaired (p < 0.05 to p < 0.001) the insulin-releasing effect of GIP, but was without effect on GLP-1. However, 48 h lipotoxic culture compromised both GIP (p < 0.05 to p < 0.001) and GLP-1 (p < 0.05 to p < 0.01) insulin-releasing actions. Glucolipotoxic culture (18 h) completely annulled the insulinotropic action of GIP, whereas GLP-1 effects were similar to control. However, when glucolipotoxic culture was extended to 48 h, both GIP- and GLP-1-mediated effects were (p < 0.05 to p < 0.001) impaired. Assessment of cell viability, number and insulin content revealed detrimental (p < 0.05 to p < 0.001) effects under all culture conditions, barring 18 h glucotoxic and lipotoxic culture. Finally, GIP-R gene and protein expression was increased (p < 0.05 to p < 0.01) under glucotoxic culture, with decreased (p < 0.05 to p < 0.001) expression following glucolipotoxic culture. GLP-1-R gene expression followed a similar trend, but protein levels were generally reduced under all culture conditions.. The results indicate that impaired insulinotropic response to GIP and GLP-1 under diabetic milieu involves mechanisms beyond simple expression of respective receptors. Topics: Blood Glucose; Blotting, Western; Cells, Cultured; Diabetes Mellitus, Type 2; Fatty Acids, Nonesterified; Gastric Inhibitory Polypeptide; Gene Expression; Glucagon-Like Peptide 1; Glucose; Humans; Incretins; Insulin; Insulin Secretion; Insulin-Secreting Cells; Receptors, Gastrointestinal Hormone | 2014 |
Duodenal-jejunal bypass and jejunectomy improve insulin sensitivity in Goto-Kakizaki diabetic rats without changes in incretins or insulin secretion.
Gastric bypass surgery can dramatically improve type 2 diabetes. It has been hypothesized that by excluding duodenum and jejunum from nutrient transit, this procedure may reduce putative signals from the proximal intestine that negatively influence insulin sensitivity (SI). To test this hypothesis, resection or bypass of different intestinal segments were performed in diabetic Goto-Kakizaki and Wistar rats. Rats were randomly assigned to five groups: duodenal-jejunal bypass (DJB), jejunal resection (jejunectomy), ileal resection (ileectomy), pair-fed sham-operated, and nonoperated controls. Oral glucose tolerance test was performed within 2 weeks after surgery. Baseline and poststimulation levels of glucose, insulin, glucagon-like peptide 1 (GLP-1), and glucose-dependent insulinotropic polypeptide (GIP) were measured. Minimal model analysis was used to assess SI. SI improved after DJB (SI = 1.14 ± 0.32 × 10(-4) min(-1) ⋅ pM(-1)) and jejunectomy (SI = 0.80 ± 0.14 × 10(-4) min(-1) ⋅ pM(-1)), but not after ileectomy or sham operation/pair feeding in diabetic rats. Both DJB and jejunal resection normalized SI in diabetic rats as shown by SI levels equivalent to those of Wistar rats (SI = 1.01 ± 0.06 × 10(-4) min(-1) ⋅ pM(-1); P = NS). Glucose effectiveness did not change after operations in any group. While ileectomy increased plasma GIP levels, no changes in GIP or GLP-1 were observed after DJB and jejunectomy. These findings support the hypothesis that anatomic alterations of the proximal small bowel may reduce factors associated with negative influence on SI, therefore contributing to the control of diabetes after gastric bypass surgery. Topics: Animals; Area Under Curve; Blood Glucose; Diabetes Mellitus, Type 2; Duodenum; Gastric Bypass; Glucagon-Like Peptide 1; Incretins; Insulin; Insulin Resistance; Insulin Secretion; Jejunum; Male; Rats; Rats, Wistar | 2014 |
The association between postprandial urinary C-peptide creatinine ratio and the treatment response to liraglutide: a multi-centre observational study.
The response to glucagon-like peptide 1 receptor agonist treatment may be influenced by endogenous β-cell function. We investigated whether urinary C-peptide creatinine ratio assessed before or during liraglutide treatment was associated with treatment response.. A single, outpatient urine sample for urinary C-peptide creatinine ratio was collected 2 h after the largest meal of the day among two separate groups: (1) subjects initiating liraglutide (0.6 → 1.2 mg daily) or (2) subjects already treated with liraglutide for 20-32 weeks. The associations between pretreatment and on-treatment urinary C-peptide creatinine ratio and HbA1c change at 32 weeks were assessed using univariate and multivariate analyses (the ratio was logarithm transformed for multivariate analyses). Changes in HbA1c according to pretreatment urinary C-peptide creatinine ratio quartiles are shown.. One hundred and sixteen subjects (70 pretreatment, 46 on treatment) with Type 2 diabetes from 10 diabetes centres were studied. In univariate analyses, neither pretreatment nor on-treatment urinary C-peptide creatinine ratio correlated with HbA1c change (Spearman rank correlation coefficient, r = -0.17, P = 0.17 and r = -0.20, P = 0.19, respectively). In multi-linear regression analyses, entering baseline HbA1c and log urinary C-peptide creatinine ratio, pretreatment and on-treatment log urinary C-peptide creatinine ratio became significantly associated with HbA1c change (P = 0.048 and P = 0.040, respectively). Mean (sd) HbA1c changes from baseline in quartiles 1 to 4 of pretreatment urinary C-peptide creatinine ratio were -3 ± 17 mmol/mol (-0.3 ± 1.6%) (P = 0.52), -12 ± 15 mmol/mol (-1.1 ± 1.4%) (P = 0.003), -11 ± 13 mmol/mol (-1.0 ± 1.2%) (P = 0.002) and -12±17 mmol/mol (-1.1±1.6%) (P=0.016), respectively.. Postprandial urinary C-peptide creatinine ratios before and during liraglutide treatment were weakly associated with the glycaemic response to treatment. Low pretreatment urinary C-peptide creatinine ratio may be more useful than higher values by predicting poorer glycaemic response. Topics: Aged; C-Peptide; Creatinine; Diabetes Mellitus, Type 2; Female; Glucagon-Like Peptide 1; Glycated Hemoglobin; Humans; Incretins; Liraglutide; Male; Middle Aged; Postprandial Period; Treatment Outcome | 2014 |
HNF4A mutation: switch from hyperinsulinaemic hypoglycaemia to maturity-onset diabetes of the young, and incretin response.
Hepatocyte nuclear factor 4α (HNF4A) is a member of the nuclear receptor family of ligand-activated transcription factors. HNF4A mutations cause hyperinsulinaemic hypoglycaemia in early life and maturity-onset diabetes of the young. Regular screening of HNF4A mutation carriers using the oral glucose tolerance test has been recommended to diagnose diabetes mellitus at an early stage. Glucagon-like peptide-1 and glucose-dependent insulinotropic polypeptide are incretin hormones, responsible for up to 70% of the secreted insulin after a meal in healthy individuals. We describe, for the first time, gradual alteration of glucose homeostasis in a patient with HNF4A mutation after resolution of hyperinsulinaemic hypoglycaemia, on serial oral glucose tolerance testing. We also measured the incretin response to a mixed meal in our patient.. Our patient was born with macrosomia and developed hyperinsulinaemic hypoglycaemia in the neonatal period. Molecular genetic analysis confirmed HNF4A mutation (p.M116I, c.317G>A) as an underlying cause of hyperinsulinaemic hypoglycaemia. Serial oral glucose tolerance testing, after the resolution of hyperinsulinaemic hypoglycaemia, confirmed the diagnosis of maturity-onset diabetes of the young at the age of 10 years. Interestingly, the intravenous glucose tolerance test revealed normal glucose disappearance rate and first-phase insulin secretion. Incretin hormones showed a suboptimal rise in response to the mixed meal, potentially explaining the discrepancy between the oral glucose tolerance test and the intravenous glucose tolerance test.. Maturity-onset diabetes of the young can develop as early as the first decade of life in persons with an HNF4A mutation. Impaired incretin response might be contributory in the early stages of HNF4A maturity-onset diabetes of the young. Topics: Blood Glucose; Child; Congenital Hyperinsulinism; Diabetes Mellitus, Type 2; Fetal Macrosomia; Glucagon-Like Peptide 1; Glucose Tolerance Test; Hepatocyte Nuclear Factor 4; Humans; Incretins; Insulin; Male; Mutation | 2014 |
Laparoscopic greater curvature plication in morbidly obese women with type 2 diabetes: effects on glucose homeostasis, postprandial triglyceridemia and selected gut hormones.
Laparoscopic greater curvature plication (LGCP) is an emerging bariatric procedure that reduces the gastric volume without implantable devices or gastrectomy. The aim of this study was to explore changes in glucose homeostasis, postprandial triglyceridemia, and meal-stimulated secretion of selected gut hormones [glucose-dependent insulinotropic polypeptide (GIP), glucagon-like peptide-1 (GLP-1), ghrelin, and obestatin] in patients with type 2 diabetes mellitus (T2DM) at 1 and 6 months after the procedure.. Thirteen morbidly obese T2DM women (mean age, 53.2 ± 8.76 years; body mass index, 40.1 ± 4.59 kg/m2) were prospectively investigated before the LGCP and at 1- and 6-month follow-up. At these time points, all study patients underwent a standardized liquid mixed-meal test, and blood was sampled for assessment of plasma levels of glucose, insulin, C-peptide, triglycerides, GIP, GLP-1, ghrelin, and obestatin.. All patients had significant weight loss both at 1 and 6 months after the LGCP (p ≤ 0.002), with mean percent excess weight loss (%EWL) reaching 29.7 ± 2.9% at the 6-month follow-up. Fasting hyperglycemia and hyperinsulinemia improved significantly at 6 months after the LGCP (p < 0.05), with parallel improvement in insulin sensitivity and HbA1c levels (p < 0.0001). Meal-induced glucose plasma levels were significantly lower at 6 months after the LGCP (p < 0.0001), and postprandial triglyceridemia was also ameliorated at the 6-month follow-up (p < 0.001). Postprandial GIP plasma levels were significantly increased both at 1 and 6 months after the LGCP (p < 0.0001), whereas the overall meal-induced GLP-1 response was not significantly changed after the procedure (p > 0.05). Postprandial ghrelin plasma levels decreased at 1 and 6 months after the LGCP (p < 0.0001) with no significant changes in circulating obestatin levels.. During the initial 6-month postoperative period, LGCP induces significant weight loss and improves the metabolic profile of morbidly obese T2DM patients, while it also decreases circulating postprandial ghrelin levels and increases the meal-induced GIP response. Topics: Blood Glucose; Body Mass Index; Diabetes Mellitus, Type 2; Female; Follow-Up Studies; Gastric Inhibitory Polypeptide; Gastrointestinal Hormones; Gastroplasty; Ghrelin; Glucagon-Like Peptide 1; Homeostasis; Humans; Laparoscopy; Middle Aged; Obesity, Morbid; Postprandial Period; Time Factors; Treatment Outcome; Triglycerides; Weight Loss | 2014 |
Plasma level of glucagon-like peptide 1 in obese Egyptians with normal and impaired glucose tolerance.
Low GLP-1 has been implicated in obesity and type 2 diabetes. Some studies reported reduced post-prandial GLP-1 levels in type 2 diabetics, whereas others reported GLP-1 levels not reduced in patients with impaired glucose tolerance (IGT) or type 2 diabetes. We undertook this study to evaluate the effect of obesity and pre-diabetes on GLP-1 levels in response to 75 g oral glucose.. Eighty subjects comprised four groups: 20 control subjects (normal weight and normal glucose tolerance (NGT)), 20 obese with NGT, 20 obese with impaired fasting glucose (IFG) and 20 obese with both IFG and impaired glucose tolerance (IGT). Laboratory tests included fasting blood glucose (FBG), 75 g glucose OGTT, fasting insulin and glucose-stimulated GLP-1 (30 min after 75 g glucose). Insulin resistance was quantified using HOMA-IR.. GLP-1 levels were significantly decreased in obese subjects compared to controls (571.17 ± 170.37 vs. 908.50 ± 169.90 pg/mL, p <0.001) and it was negatively correlated with body mass index (BMI) and waist circumference in all studied groups. Levels of GLP-1 were negatively correlated with HOMA-IR in all obese groups (r = -0.75, p <0.001). No significant difference was found in GLP-1 levels between all obese subjects (611.50 ± 187.96, 577.50 ± 150.85, 524.50 ± 167.35 pg/mL respectively, p >0.05). Morbidly obese cases (n = 15) had a significantly higher fasting insulin (25.20 ± 2.49 vs. 14 ± 3.81 μIU/ml), higher HOMA-IR (6.69 ± 1.2 vs. 3.48 ± 1.20), and lower GLP- 1 (212.0 ± 35.64 vs. 603.82 ± 136.35 pg/mL) (p <0.001) compared to non-morbid obese cases (n = 45).. Obesity reduces the GLP-1 levels. In insulin resistance, GLP-1 levels were reduced and it was related to the degree of insulin resistance. Topics: Adult; Blood Glucose; Case-Control Studies; Diabetes Mellitus, Type 2; Fasting; Female; Glucagon-Like Peptide 1; Glucose Intolerance; Glucose Tolerance Test; Humans; Insulin; Insulin Resistance; Male; Middle Aged; Obesity; Obesity, Morbid; Prediabetic State | 2014 |
Role of genetic variation in the cannabinoid receptor gene (CNR1) (G1359A polymorphism) on weight loss and cardiovascular risk factors after liraglutide treatment in obese patients with diabetes mellitus type 2.
A polymorphism (1359 G/A) of the cannabinoid receptor 1 (CNR1) gene was reported as a common polymorphism (rs1049353) with potential implications in weight loss. We decide to investigate the role of this polymorphism on metabolic changes and weight loss secondary to treatment with liraglutide.. A population of 86 patients with diabetes mellitus type 2 and obesity, unable to achieve glycemic control (hemoglobine glycate A1c >7%) with metformin alone or associated to sulfonylurea, who require initiation of liraglutide treatment in progressive dose to 1.8 mg/d subcutaneously, was analyzed.. Fifty-one patients (59.3%) had the genotype G1359G, and 35 patients (40.7%) had G1359A (28 patients, 32.6%) or A1359A (7 patients, 8.1%) (A allele carriers). In patients with both genotypes, basal glucose, HbA1c, body mass index, weight, fat mass, waist circumference, and systolic blood pressures decreased. In patients with G1359G genotype, total cholesterol and low-density lipoprotein cholesterol decreased, and in patients with A allele, homeostasis model assessment for insulin resistance decreased, too.. There is an association of the A allele with an improvement of insulin resistance secondary to weight loss after liraglutide treatment in obese patients with diabetes mellitus type 2. Noncarriers of A allele showed an improvement in cholesterol levels after weight loss. Topics: Adult; Aged; Cardiovascular Diseases; Diabetes Mellitus, Type 2; Female; Genetic Variation; Glucagon-Like Peptide 1; Humans; Hypoglycemic Agents; Insulin Resistance; Liraglutide; Male; Middle Aged; Obesity; Prospective Studies; Receptor, Cannabinoid, CB1; Risk Factors; Treatment Outcome; Weight Loss | 2014 |
Effects of short chain fatty acid producing bacteria on epigenetic regulation of FFAR3 in type 2 diabetes and obesity.
The human gut microbiota and microbial influences on lipid and glucose metabolism, satiety, and chronic low-grade inflammation are known to be involved in metabolic syndrome. Fermentation end products, especially short chain fatty acids, are believed to engage the epigenetic regulation of inflammatory reactions via FFARs (free fatty acid receptor) and other short chain fatty acid receptors. We studied a potential interaction of the microbiota with epigenetic regulation in obese and type 2 diabetes patients compared to a lean control group over a four month intervention period. Intervention comprised a GLP-1 agonist (glucagon-like peptide 1) for type 2 diabetics and nutritional counseling for both intervention groups. Microbiota was analyzed for abundance, butyryl-CoA:acetate CoA-transferase gene and for diversity by polymerase chain reaction and 454 high-throughput sequencing. Epigenetic methylation of the promoter region of FFAR3 and LINE1 (long interspersed nuclear element 1) was analyzed using bisulfite conversion and pyrosequencing. The diversity of the microbiota as well as the abundance of Faecalibacterium prausnitzii were significantly lower in obese and type 2 diabetic patients compared to lean individuals. Results from Clostridium cluster IV and Clostridium cluster XIVa showed a decreasing trend in type 2 diabetics in comparison to the butyryl-CoA:acetate CoA-transferase gene and according to melt curve analysis. During intervention no significant changes were observed in either intervention group. The analysis of five CpGs in the promoter region of FFAR3 showed a significant lower methylation in obese and type 2 diabetics with an increase in obese patients over the intervention period. These results disclosed a significant correlation between a higher body mass index and lower methylation of FFAR3. LINE-1, a marker of global methylation, indicated no significant differences between the three groups or the time points, although methylation of type 2 diabetics tended to increase over time. Our results provide evidence that a different composition of gut microbiota in obesity and type 2 diabetes affect the epigenetic regulation of genes. Interactions between the microbiota and epigenetic regulation may involve not only short chain fatty acids binding to FFARs. Therefore dietary interventions influencing microbial composition may be considered as an option in the engagement against metabolic syndrome. Topics: Adult; Aged; Biodiversity; Body Mass Index; Case-Control Studies; Coenzyme A-Transferases; Diabetes Mellitus, Type 2; DNA Methylation; Epigenesis, Genetic; Fatty Acids, Volatile; Feces; Feeding Behavior; Female; Gastrointestinal Tract; Glucagon-Like Peptide 1; Gram-Positive Bacteria; Gram-Positive Endospore-Forming Bacteria; Humans; Liraglutide; Long Interspersed Nucleotide Elements; Male; Microbiota; Middle Aged; Obesity; Promoter Regions, Genetic; Receptors, G-Protein-Coupled | 2014 |
The glycemic/metabolic responses to meal tolerance tests at breakfast, lunch and dinner, and effects of the mitiglinide/voglibose fixed-dose combination on postprandial profiles in Japanese patients with type 2 diabetes mellitus.
Meal tolerance tests (MTTs) are usually conducted at breakfast after overnight fasting in type 2 diabetes mellitus (T2DM) patients, but differences in postprandial glycemic responses between meals have been reported.. We conducted MTTs at breakfast, lunch, and dinner to examine the effects of a fixed combination of 10 mg mitiglinide/0.2 mg voglibose (the combination) on glycemic/metabolic responses to meals during the day in T2DM patients. MTTs with unified meals were conducted in 11 T2DM patients before and after 4 weeks of treatment with the combination administered thrice daily before meals. Glycemic/metabolic profiles measured before and at 30, 60, and 120 min after each meal were compared between each meal and between the baseline and treatment periods.. The combination significantly reduced postprandial hyperglycemia after each meal. Postprandial AUC0 - 120 min for insulin significantly decreased after lunch and dinner compared with after breakfast, while insulin levels significantly increased at only 30 min after breakfast and dinner. The combination also significantly increased postprandial C-peptide and active glucagon-like peptide-1 levels, and reduced free fatty acid and triglyceride levels, but did not significantly affect glucagon levels compared with baseline, confirming that treatment with the combination improves postprandial responses in Japanese T2DM patients. Topics: Aged; Blood Glucose; Breakfast; C-Reactive Protein; Diabetes Mellitus, Type 2; Drug Combinations; Fatty Acids, Nonesterified; Female; Glucagon; Glucagon-Like Peptide 1; Humans; Hyperglycemia; Hypoglycemic Agents; Inositol; Insulin; Isoindoles; Lunch; Male; Meals; Middle Aged; Postprandial Period; Triglycerides | 2014 |
Type 2 diabetes and congenital hyperinsulinism cause DNA double-strand breaks and p53 activity in β cells.
β cell failure in type 2 diabetes (T2D) is associated with hyperglycemia, but the mechanisms are not fully understood. Congenital hyperinsulinism caused by glucokinase mutations (GCK-CHI) is associated with β cell replication and apoptosis. Here, we show that genetic activation of β cell glucokinase, initially triggering replication, causes apoptosis associated with DNA double-strand breaks and activation of the tumor suppressor p53. ATP-sensitive potassium channels (KATP channels) and calcineurin mediate this toxic effect. Toxicity of long-term glucokinase overactivity was confirmed by finding late-onset diabetes in older members of a GCK-CHI family. Glucagon-like peptide-1 (GLP-1) mimetic treatment or p53 deletion rescues β cells from glucokinase-induced death, but only GLP-1 analog rescues β cell function. DNA damage and p53 activity in T2D suggest shared mechanisms of β cell failure in hyperglycemia and CHI. Our results reveal membrane depolarization via KATP channels, calcineurin signaling, DNA breaks, and p53 as determinants of β cell glucotoxicity and suggest pharmacological approaches to enhance β cell survival in diabetes. Topics: Animals; Biomarkers; Calcineurin; Cell Death; Cell Proliferation; Congenital Hyperinsulinism; Diabetes Mellitus, Type 2; Disease Models, Animal; DNA Breaks, Double-Stranded; Enzyme Activation; Enzyme Induction; Fasting; Glucagon-Like Peptide 1; Glucokinase; Glucose; Humans; Insulin-Secreting Cells; Membrane Potentials; Mice; Transgenes; Tumor Suppressor Protein p53 | 2014 |
Pancreatitis associated with the use of GLP-1 analogs and DPP-4 inhibitors: a case/non-case study from the French Pharmacovigilance Database.
In the recent past, concerns have raised regarding the potential risk of acute pancreatitis among type 2 diabetic patients using incretin-based drugs such as glucagon-like peptide 1 (GLP-1) analogs and dipeptidyl peptidase 4 (DPP-4) inhibitors. The aim of this study is to investigate the association between exposure to incretin-based drugs and the occurrence of pancreatitis reported in the French Pharmacovigilance Database. The case/non-case method was performed from serious adverse drug reactions (ADRs) involving antihyperglycemic agents (except insulin alone) reported to the French pharmacovigilance system between March 2008 (first marketing of an incretin-based drug in France) and March 2013. Cases were defined as reports of pancreatitis, and all other serious ADRs were considered non-cases. Disproportionality was assessed by calculating reporting odds ratios (ROR) adjusted for age, gender, history of pancreatitis, other antihyperglycemic drugs and other drugs associated with a higher risk of pancreatitis. Among 3,109 serious ADRs, 147 (4.7 %) reports of pancreatitis were identified as cases and 2,962 reports (95.3 %) of other ADRs as non-cases. Among the cases, 122 (83.0 %) involved incretin-based drugs. Disproportionality was found for all incretin-based drugs (adjusted ROR: 15.7 [95 % CI 9.8-24.9]), all GLP-1 analogs (29.4 [16.0-53.8]), exenatide (28.3 [12.8-62.3]), liraglutide (30.4 [15.4-60.0]), all DPP-4 inhibitors (12.1 [7.3-20.0]), sitagliptin (12.4 [7.3-21.0]), saxagliptin (15.1 [4.3-52.7]), and vildagliptin (7.4 [3.1-17.6]). Temporal analysis found disproportionality for incretin-based drugs since their first year of marketing in France. Compared with other antihyperglycemic agents, use of incretin-based drugs is associated with an increased risk of reported pancreatitis in France. Topics: Adult; Aged; Aged, 80 and over; Case-Control Studies; Databases, Factual; Diabetes Mellitus, Type 2; Dipeptidyl-Peptidase IV Inhibitors; Female; France; Glucagon-Like Peptide 1; Humans; Male; Middle Aged; Pancreatitis; Pharmacovigilance | 2014 |
Glucagon-like peptide 1 analogue therapy directly modulates innate immune-mediated inflammation in individuals with type 2 diabetes mellitus.
Glucagon-like peptide 1 (GLP-1) is a gut hormone used in the treatment of type 2 diabetes mellitus. There is emerging evidence that GLP-1 has anti-inflammatory activity in humans, with murine studies suggesting an effect on macrophage polarisation. We hypothesised that GLP-1 analogue therapy in individuals with type 2 diabetes mellitus would affect the inflammatory macrophage molecule soluble CD163 (sCD163) and adipocytokine profile.. We studied ten obese type 2 diabetes mellitus patients starting GLP-1 analogue therapy at a hospital-based diabetes service. We investigated levels of sCD163, TNF-α, IL-1β, IL-6, adiponectin and leptin by ELISA, before and after 8 weeks of GLP-1 analogue therapy.. GLP-1 analogue therapy reduced levels of the inflammatory macrophage activation molecule sCD163 (220 ng/ml vs 171 ng/ml, p < 0.001). This occurred independent of changes in body weight, fructosamine and HbA1c. GLP-1 analogue therapy was associated with a decrease in levels of the inflammatory cytokines TNF-α (264 vs 149 pg/ml, p < 0.05), IL-1β (2,919 vs 748 pg/ml, p < 0.05) and IL-6 (1,379 vs 461 pg/ml p < 0.05) and an increase in levels of the anti-inflammatory adipokine adiponectin (4,480 vs 6,290 pg/ml, p < 0.002).. In individuals with type 2 diabetes mellitus, GLP-1 analogue therapy reduces the frequency of inflammatory macrophages. This effect is not dependent on the glycaemic or body weight effects of GLP-1. Topics: Body Weight; Diabetes Mellitus, Type 2; Female; Glucagon-Like Peptide 1; Humans; Immunity, Innate; Inflammation; Inflammation Mediators; Male; Middle Aged | 2014 |
Unsaturated glycoceramides as molecular carriers for mucosal drug delivery of GLP-1.
The incretin hormone Glucagon-like peptide 1 (GLP-1) requires delivery by injection for the treatment of Type 2 diabetes mellitus. Here, we test if the properties of glycosphingolipid trafficking in epithelial cells can be applied to convert GLP-1 into a molecule suitable for mucosal absorption. GLP-1 was coupled to the extracellular oligosaccharide domain of GM1 species containing ceramides with different fatty acids and with minimal loss of incretin bioactivity. When applied to apical surfaces of polarized epithelial cells in monolayer culture, only GLP-1 coupled to GM1-ceramides with short- or cis-unsaturated fatty acids trafficked efficiently across the cell to the basolateral membrane by transcytosis. In vivo studies showed mucosal absorption after nasal administration. The results substantiate our recently reported dependence on ceramide structure for trafficking the GM1 across polarized epithelial cells and support the idea that specific glycosphingolipids can be harnessed as molecular vehicles for mucosal delivery of therapeutic peptides. Topics: Amino Acid Sequence; Animals; Cell Line; Ceramides; Diabetes Mellitus, Type 2; Drug Carriers; G(M1) Ganglioside; Glucagon-Like Peptide 1; HEK293 Cells; Humans; Incretins; Male; Mice; Mice, Inbred C57BL; Models, Molecular; Molecular Sequence Data; Transcytosis | 2014 |
Early improvement of postprandial lipemia after bariatric surgery in obese type 2 diabetic patients.
Bariatric surgery (BS) is able to positively influence fasting lipid profile in obese type 2 diabetic patients (T2DM), but no data is available on the impact of BS on postprandial lipid metabolism neither on its relation with incretin hormones. We evaluated the short-term (2 weeks) effects of BS on fasting and postprandial lipid metabolism in obese T2DM patients and the contribution of changes in active GLP-1.. We studied 25 obese T2DM patients (age = 46 ± 8 years, BMI = 44 ± 7 kg/m2), of which 15 underwent sleeve gastrectomy and 10 underwent gastric bypass. Lipid and incretin hormone concentrations were evaluated for 3 h after ingestion of a liquid meal before and 2 weeks after BS.. After BS, there was a significant reduction in body weight (p < 0.001), fasting plasma glucose (p < 0.001), fasting plasma insulin (p < 0.05), HOMA-IR (p < 0.001), and fasting plasma lipids (p < 0.05). The meal response of plasma triglycerides, total cholesterol, and HDL cholesterol was significantly lower compared to pre-intervention (p < 0.05, p < 0.001). In particular, the incremental area under the curve (IAUC) of plasma triglycerides decreased by 60% (p < 0.005). The meal-stimulated response of active GLP-1 increased, reaching a statistical significance (p < 0.001).. BS leads to an early improvement of fasting and postprandial lipemia. The fall in fasting triglycerides is associated with an improvement of insulin resistance, while the reduction of postprandial lipemia is likely related to reduced intestinal lipid absorption consequent to bariatric surgery. Topics: Adult; Bariatric Surgery; Blood Glucose; Diabetes Mellitus, Type 2; Fasting; Female; Gastric Inhibitory Polypeptide; Glucagon-Like Peptide 1; Glycated Hemoglobin; Homeostasis; Humans; Hyperlipidemias; Incretins; Insulin Resistance; Lipids; Male; Middle Aged; Obesity, Morbid; Postprandial Period; Treatment Outcome; Triglycerides | 2014 |
Early liraglutide treatment is better in glucose control, β-cell function improvement and mass preservation in db/db mice.
Glucagon-like peptide-1 (GLP-1) has been proved to have effects of anti-hyperglycemia and β-cell preservation. However, it is still unclear whether there are differences between early and late GLP-1 intervention in type 2 diabetes mellitus (T2DM). We divided the mice into 5 groups: early treated group (n=7, 8-week old, fasting glucose>10mmol/l), late treated group (n=7, 10-week old, fasting glucose>20mmol/l), early control group (n=7), late control group (n=7) and wild type group (n=7). Treated group was injected with liraglutide (a GLP-1 analog) 300μg/kg bid for 4 weeks, while control group was given saline at the same time. The results showed that compared with control group, food intake and body weight gain were reduced in both early and late treated group (p<0.05), and there was no significance between the two treated groups. Early liraglutide intervention showed better improvements in glucose control, acute insulin response to glucose (AIRg) and disposition index (before vs. after treatment, AIRg 1.01±0.53 vs. 2.98±0.63, disposition index 10.81±0.89 vs. 27.4±2.15) than late intervention (AIRg 0.99±0.02 vs. 1.41±0.32, disposition index 3.47±0.38 vs. 6.43±1.62, p=0.001). The histopathology of the pancreas showed the estimated β-cell mass (BCM) was increased more in early treated group than that in late one (0.03 vs. 0.01g). Expressions of the proliferation related genes PDX-1, MafA and GLP-1 receptor (GLP-1R) in early treated group were 1.81, 2.57 and 1.59 times as much as that in late treated group. In conclusion, early liraglutide intervention was better in glucose control, β-cell function improvement and β-cell mass preservation. Topics: Animals; Body Mass Index; Diabetes Mellitus, Type 2; Eating; Gene Expression Regulation; Glucagon-Like Peptide 1; Glucagon-Like Peptide-1 Receptor; Glucose; Homeodomain Proteins; Hypoglycemic Agents; Insulin-Secreting Cells; Liraglutide; Maf Transcription Factors, Large; Male; Mice; Receptors, Glucagon; Trans-Activators | 2014 |
Liraglutide therapy in obese people with type 2 diabetes - experience of a weight management centre.
Topics: Adult; Aged; Aged, 80 and over; Diabetes Mellitus, Type 2; Female; Glucagon-Like Peptide 1; Humans; Hypoglycemic Agents; Liraglutide; Male; Middle Aged; Obesity; Weight Loss; Young Adult | 2014 |
Alternative dosing strategies for liraglutide in patients with type 2 diabetes mellitus.
Alternative dosing strategies for liraglutide in patients with type 2 diabetes mellitus are described.. Nausea is the most common adverse effect of liraglutide, affecting upward of 40% of patients depending on the dose of liraglutide and concomitant medications. The frequency of nausea is dose dependent, with a lower rate of nausea reported with 0.6 mg (5.2-10.7%) compared with 1.2 mg (10.5-29.2%) or 1.8 mg (6.8-40%). Due to dose-related adverse effects, it is reasonable to assume that smaller or slower dosage adjustments may improve tolerability and increase the likelihood that the patient will be able to continue therapy long term. Depending on the degree of nausea and the necessary reduction in blood glucose levels, it is reasonable to consider a smaller or slower increase in liraglutide dosage than what is currently recommended by the manufacturer. For instance, increasing the dose of liraglutide by 0.3 mg weekly instead of 0.6 mg weekly may help prevent or decrease the severity of nausea. Alternative dosing strategies may also include increasing the dosage every two weeks or even monthly rather than weekly. Depending on the degree of nausea and glycemic control, providers may recommend patients stop increasing the dosage. It is important to proactively assess each patient's ability to comply with special instructions to ensure safe use of the product.. Alternative dosing strategies that allow for slower dosage adjustments or smaller dosages may offer improved tolerability and increase the likelihood that patients will be able to continue long-term therapy with liraglutide. Topics: Blood Glucose; Diabetes Mellitus, Type 2; Dose-Response Relationship, Drug; Glucagon-Like Peptide 1; Humans; Hypoglycemic Agents; Liraglutide; Nausea | 2014 |
The incretin response after successful islet transplantation.
Topics: Aged; Diabetes Mellitus, Type 2; Female; Glucagon-Like Peptide 1; Glucose Tolerance Test; Humans; Incretins; Islets of Langerhans Transplantation; Male; Middle Aged | 2014 |
PAS kinase is a nutrient and energy sensor in hypothalamic areas required for the normal function of AMPK and mTOR/S6K1.
The complications caused by overweight, obesity and type 2 diabetes are one of the main problems that increase morbidity and mortality in developed countries. Hypothalamic metabolic sensors play an important role in the control of feeding and energy homeostasis. PAS kinase (PASK) is a nutrient sensor proposed as a regulator of glucose metabolism and cellular energy. The role of PASK might be similar to other known metabolic sensors, such as AMP-activated protein kinase (AMPK) and the mammalian target of rapamycin (mTOR). PASK-deficient mice resist diet-induced obesity. We have recently reported that AMPK and mTOR/S6K1 pathways are regulated in the ventromedial and lateral hypothalamus in response to nutritional states, being modulated by anorexigenic glucagon-like peptide-1 (GLP-1)/exendin-4 in lean and obese rats. We identified PASK in hypothalamic areas, and its expression was regulated under fasting/re-feeding conditions and modulated by exendin-4. Furthermore, PASK-deficient mice have an impaired activation response of AMPK and mTOR/S6K1 pathways. Thus, hypothalamic AMPK and S6K1 were highly activated under fasted/re-fed conditions. Additionally, in this study, we have observed that the exendin-4 regulatory effect in the activity of metabolic sensors was lost in PASK-deficient mice, and the anorexigenic properties of exendin-4 were significantly reduced, suggesting that PASK could be a mediator in the GLP-1 signalling pathway. Our data indicated that the PASK function could be critical for preserving the nutrient effect on AMPK and mTOR/S6K1 pathways and maintain the regulatory role of exendin-4 in food intake. Some of the antidiabetogenic effects of exendin-4 might be modulated through these processes. Topics: AMP-Activated Protein Kinases; Animals; Diabetes Mellitus, Type 2; Eating; Energy Metabolism; Exenatide; Glucagon-Like Peptide 1; Homeostasis; Hypothalamus; Male; Mice, Inbred C57BL; Peptides; Protein Serine-Threonine Kinases; Ribosomal Protein S6 Kinases, 90-kDa; Signal Transduction; TOR Serine-Threonine Kinases; Venoms | 2014 |
Severe acute renal failure in patients treated with glucagon-like peptide-1 receptor agonists.
We report two patients with diabetes in whom acute renal failure requiring hemodialysis occurred while on treatment with glucagon-like peptide-1 receptor agonists. We discuss the mechanisms of this complication and the potential for its prevention. Topics: Acute Kidney Injury; Aged; Diabetes Mellitus, Type 2; Female; Glucagon-Like Peptide 1; Glucagon-Like Peptide-1 Receptor; Humans; Hypoglycemic Agents; Male; Middle Aged; Prognosis; Receptors, Glucagon; Renal Dialysis | 2014 |
Effects of exenatide on metabolic parameters/control in obese Japanese patients with type 2 diabetes.
The effects of exenatide on glycemic control, lipid metabolism, blood pressure, and gastrointestinal symptoms were investigated in obese Japanese patients with type 2 diabetes mellitus. Twenty-six outpatients were enrolled and administered 5 μg of exenatide twice daily. If there was insufficient weight loss and/or insufficient improvement in glycemic control, the dose was increased to 10 μg twice daily. Follow-up was continued until the 12th week of administration. Hemoglobin A1c, glycoalbumin, fasting plasma glucose, body weight, fasting serum C-peptide, serum lipids, blood pressure, and pulse rate were measured before and after the observation period. In the initial phase of exenatide therapy, each patient received a diary to record gastrointestinal symptoms. During treatment with exenatide, hemoglobin A1c decreased significantly and serum C-peptide increased significantly. Body weight, low-density lipoprotein cholesterol, and systolic blood pressure decreased significantly. Nausea was the most frequent gastrointestinal symptom and occurred in 16 patients. Its onset was noted at a mean of 1.7 h after injection, the mean duration was 1.1 h, and it continued for a mean of 9.3 days after the initiation of administration. Patients with nausea showed a significant decrease in hemoglobin Alc, glycoalbumin, or body weight compared with those without nausea. These findings suggest that a more marked improvement in metabolic parameters by exenatide can be partly dependent on the manifestation of gastrointestinal symptoms. Topics: Adult; Aged; Anti-Obesity Agents; Anticholesteremic Agents; Antihypertensive Agents; Body Mass Index; Diabetes Mellitus, Type 2; Exenatide; Female; Follow-Up Studies; Gastrointestinal Agents; Glucagon-Like Peptide 1; Humans; Hyperglycemia; Hypoglycemic Agents; Injections, Subcutaneous; Japan; Male; Middle Aged; Nausea; Obesity; Peptides; Venoms; Weight Loss | 2014 |
[Liraglutide in polycystic ovary syndrome].
Topics: Adult; Diabetes Mellitus, Type 2; Drug Synergism; Female; Glucagon-Like Peptide 1; Hirsutism; Humans; Hypoglycemic Agents; Liraglutide; Menstrual Cycle; Metformin; Obesity, Morbid; Polycystic Ovary Syndrome; Testosterone; Weight Loss | 2014 |
The impact of improved glycaemic control with GLP-1 receptor agonist therapy on diabetic retinopathy.
Rapid improvement in glycaemic control with GLP-1 receptor agonist (RA) therapy has been reported to be associated with significant progression of diabetic retinopathy. This deterioration is transient, and continuing GLP-1 RA treatment is associated with reversal of this phenomenon. Pre-existent maculopathy, higher grade of retinopathy and longer duration of diabetes may be risk factors for persistent deterioration. Topics: Blood Glucose; Diabetes Mellitus, Type 2; Diabetic Retinopathy; Disease Progression; Exenatide; Follow-Up Studies; Glucagon-Like Peptide 1; Glucagon-Like Peptide-1 Receptor; Glycated Hemoglobin; Humans; Hypoglycemic Agents; Middle Aged; Peptides; Receptors, Glucagon; Risk Factors; Venoms | 2014 |
Real-world cost-effectiveness: lower cost of treating patients to glycemic goal with liraglutide versus exenatide.
While the liraglutide effect and action in diabetes (LEAD-6) clinical trial compared the efficacy and safety of liraglutide once daily (LIRA) to exenatide twice daily (EXEN) in adult patients with type 2 diabetes, few studies have explored the associated per-patient costs of glycemic goal achievement of their use in a real-world clinical setting.. This retrospective cohort study used integrated medical and pharmacy claims linked with glycated hemoglobin A1C (A1C) results from the IMS Patient-Centric Integrated Data Warehouse. Patients' ≥18 years and naïve to incretin therapies during a 6-month pre-index period, with ≥1 prescription for LIRA or EXEN between January 2010 and December 2010, were included. Patients with evidence of insulin use (pre- or post-index) were excluded. Only patients who were persistent on their index treatment during a 180-day post-index period were included. Follow-up A1C assessments were based on available laboratory data within 45 days before or after the 6-month post-index point in time. Diabetes-related pharmacy costs over the 6-month post-index period were captured and included costs for both the index drugs and concomitant diabetes medications.. 234 LIRA and 182 EXEN patients were identified for the analysis. The adjusted predicted diabetes-related pharmacy costs per patient over the 6-month post-index period were higher for LIRA compared to EXEN ($2,002 [95% confidence interval (CI): $1,981, $2,023] vs. $1,799 [95% CI: $1,778, $1,820]; P < 0.001). However, a higher adjusted predicted percentage of patients on LIRA reached A1C < 7% goal (64.4% [95% CI: 63.5, 65.3] vs. 53.6% [95% CI: 52.6, 54.6]; P < 0.05), translating into lower average diabetes-related pharmacy costs per successfully treated patient for LIRA as compared to EXEN ($3,108 vs. $3,354; P < 0.0001).. Although predicted diabetes-related pharmacy costs were greater with LIRA vs. EXEN, a higher proportion of patients on LIRA achieved A1C < 7%, resulting in a lower per-patient cost of A1C goal achievement with LIRA compared to EXEN. Topics: Adolescent; Adult; Aged; Cohort Studies; Cost-Benefit Analysis; Diabetes Mellitus, Type 2; Drug Costs; Exenatide; Female; Glucagon-Like Peptide 1; Glycated Hemoglobin; Humans; Hypoglycemic Agents; Liraglutide; Male; Middle Aged; Peptides; Retrospective Studies; Treatment Outcome; Venoms; Young Adult | 2014 |
Glucagon-like peptide-1 receptor agonists vs. insulin in inadequately controlled patients with type 2 diabetes. Is this meta-analysis miscalculated?
Topics: Diabetes Mellitus, Type 2; Female; Glucagon-Like Peptide 1; Humans; Hypoglycemic Agents; Insulin; Male; Receptors, Glucagon | 2014 |
Changes in liraglutide-induced body composition are related to modifications in plasma cardiac natriuretic peptides levels in obese type 2 diabetic patients.
Liraglutide treatment can improve glycemic control with a concomitant weight loss, but the underlying mechanism on weight loss is not completely understood. Cardiac natriuretic peptides (NPs) can resist body fat accumulation through increasing adipocytes lypolysis. In this study, we tested the hypothesis that liraglutide-induced weight loss was associated with increased plasma NPs concentrations.. Thirty-one outpatients with type 2 diabetes (T2D) treated with metformin and other oral antidiabetic drugs except for thiazolidinediones (TZDs) were subcutaneously administered with liraglutide for 12 weeks. Body composition, abdominal visceral adipose tissue areas (VAT) and subcutaneous adipose tissue areas (SAT) were assessed at pre- and post-treatment by dual-energy X-ray absorptiometry (DXA) scanning and abdominal computerized tomography (CT). Plasma atrial natriuretic peptides (ANP) and B-type ventricular natriuretic peptides (BNP) concentrations were tested by commercial ELISA Kit quantitatively.. Following 12-week liraglutide treatment, body weight, waist circumference, total fat and lean mass, fat percentage, SAT and VAT areas were significantly reduced from baseline. Concurrently, plasma ANP and BNP levels were significantly increased following 12-week liraglutide treatment. There were significant correlations between the reductions in body compositions and the increases in both plasma ANP and BNP levels.. There were significant correlations between increases in both plasma ANP and BNP levels and changes in liraglutide-induced body composition. Our data implied that increases in plasma NPs may add a novel dimension to explain how liraglutide induces weight loss. Topics: Adult; Atrial Natriuretic Factor; Biomarkers; Body Composition; Diabetes Mellitus, Type 2; Female; Follow-Up Studies; Glucagon-Like Peptide 1; Humans; Hypoglycemic Agents; Liraglutide; Male; Middle Aged; Natriuretic Peptide, Brain; Natriuretic Peptides; Obesity; Prospective Studies | 2014 |
Improvement of psoriasis during glucagon-like peptide-1 analogue therapy in type 2 diabetes is associated with decreasing dermal γδ T-cell number: a prospective case-series study.
A few case reports suggest that incretin-based therapies could improve psoriasis in patients with type 2 diabetes, the mechanism(s) of which remain unclear.. To determine the effects after 16-20 weeks of treatment with a glucagon-like peptide (GLP)-1 analogue on clinical severity and histopathological aspects of psoriasis in patients with type 2 diabetes, and to examine the presence of γδ T cells and the expression of interleukin (IL)-17 in psoriasis before and after treatment.. Seven patients with type 2 diabetes and psoriasis were followed. Psoriasis Area and Severity Index (PASI) was measured at baseline (T0) and after 7 ± 1 (T1) and 18 ± 2 (T2) weeks' treatment with exenatide/liraglutide. The histopathological pattern of psoriasis, and flow cytometry and immunological data (γδ T-cell percentage and IL-17 expression) were obtained from psoriatic and control sites.. The mean PASI decreased from 12·0 ± 5·9 to 9·2 ± 6·4 (P = 0·04). Histological analysis showed a reduction in epidermal thickness after treatment. The dermal γδ T-cell percentage was higher in psoriatic lesions than in control specimens (P = 0·03), as was IL-17 expression (P = 0·018). A reduction of γδ T cells from 6·7 ± 4·5% to 2·7 ± 3·8% (P = 0·05) was demonstrated in the six patients with improved/unchanged PASI. A correlation between PASI and γδ T-cell percentage evolution during therapy (T2-T0) was noted (r = 0·894, P = 0·007). IL-17 was reduced in the four patients with the highest PASI reductions.. The administration of a GLP-1 analogue improved clinical psoriasis severity in patients with type 2 diabetes. This favourable outcome was associated with a decrease of dermal γδ T-cell number and IL-17 expression. Further studies are needed to establish long-term efficacy in (diabetic) patients with psoriasis. Topics: Adult; Chronic Disease; Diabetes Mellitus, Type 2; Exenatide; Female; Glucagon-Like Peptide 1; Humans; Hypoglycemic Agents; Incretins; Interleukin-17; Liraglutide; Lymphocyte Count; Male; Middle Aged; Peptides; Prospective Studies; Psoriasis; Severity of Illness Index; Skin; T-Lymphocytes; Treatment Outcome; Venoms | 2014 |
Progressive change of intra-islet GLP-1 production during diabetes development.
Glucagon-like peptide 1 (GLP-1) and glucagon share the same precursor molecule proglucagon, but each arises from a distinct posttranslational process in a tissue-specific manner. Recently, it has been shown that GLP-1 is co-expressed with glucagon in pancreatic islet cells. This study was aimed to investigate the progressive changes of GLP-1 versus glucagon production in pancreatic islets during the course of diabetes development.. Both type 1 (non-obese diabetes mice) and type 2 (db/db mice) diabetes models were employed in this study. The mice were monitored closely for their diabetes progression and were sacrificed at different stages according to their blood glucose levels. GLP-1 and glucagon expression in the pancreatic islets was examined using immunohistochemistry assays. Quantitative analysis was performed to evaluate the significance of the changes.. The ratio of GLP-1-expressing cells to glucagon-expressing cells in the islets showed significant, progressive increase with the development of diabetes in db/db mice. The increase of GLP-1 expression was in agreement with the upregulation of PC1/3 expression in these cells. Interestingly, intra-islet GLP-1 expression was not significantly changed during the development of type 1 diabetes in non-obese diabetes mice.. The study demonstrated that GLP-1 was progressively upregulated in pancreatic islets during type 2 diabetes development. In addition, the data suggest clear differences in intra-islet GLP-1 production between type 1 and type 2 diabetes developments. These differences may have an effect on the clinical and pathophysiological processes of these diseases and may be a target for therapeutic approaches. Topics: Algorithms; Animals; Diabetes Mellitus, Type 1; Diabetes Mellitus, Type 2; Disease Progression; Female; Glucagon; Glucagon-Like Peptide 1; Glucagon-Secreting Cells; Immunohistochemistry; Islets of Langerhans; Male; Mice, Inbred C57BL; Mice, Inbred NOD; Mice, Mutant Strains; Prediabetic State; Proprotein Convertase 1; Up-Regulation | 2014 |
Epidermal insulin resistance as a therapeutic target in acanthosis nigricans?
Topics: Acanthosis Nigricans; Adult; Diabetes Mellitus, Type 2; Epidermis; Female; Glucagon-Like Peptide 1; Humans; Hypoglycemic Agents; Insulin Resistance; Liraglutide | 2014 |
Marked improvement of insulin sensitivity without enhancement of GLP-1 and insulin secretion after Roux-en-Y gastric bypass surgery in a mildly obese patient with diabetes.
Roux-en-Y gastric bypass is an option of treatment for morbidly obese patients with diabetes. However, the value of the operation in mildly obese patients is not established. We report the first prospective systematic endocrine and metabolic analysis in a mildly obese patient who underwent a Roux-en-Y gastric bypass. In a 49-year-old man with BMI 32.6 kg/m(2) having type 2 diabetes, intramucosal gastric cancer was treated by partial gastrectomy with Roux-en-Y gastric bypass. Pre-operatively, he received 53 U/day insulin and the HbA1c value was 63 mmol/mol: meal tolerance test showed diabetic hyperglycemia and low insulin sensitivity with attenuated insulin secretion and normal glucagon-like peptide 1(7-36) secretion. After the operation, hypoglycemic agent was stopped. Body weight reduced from 84.0 to 77.0 kg within 2 weeks and increased thereafter to 79.4 kg at 4 months later, when the degree of hyperglycemia was unchanged as indexed by a HbA1c value of 62 mmol/mol. Upon repeated meal tolerance test, no increase of glucagon-like peptide 1 and insulin secretion, but significantly improved hepatic and peripheral insulin sensitivity were found, compared to the preoperative meal tolerance test. Marked dissociation of endocrine and metabolic effects of Roux-en-Y gastric bypass, that is, absence of increased glucagon-like peptide 1/insulin secretion with improvement of insulin sensitivity, was found in a mildly obese patient with type 2 diabetes. Topics: Diabetes Mellitus, Type 2; Gastric Bypass; Glucagon-Like Peptide 1; Humans; Insulin; Insulin Secretion; Male; Middle Aged; Obesity | 2014 |
Beneficial effects of liraglutide on adipocytokines, insulin sensitivity parameters and cardiovascular risk biomarkers in patients with Type 2 diabetes: a prospective study.
To evaluate the effects of liraglutide after 14 weeks of treatment on serum adipokines, insulin resistance index and cardiovascular risk biomarkers in overweight or obese T2DM patients unable to achieve glycemic control with metformin alone or in association with a sulfonylurea in daily clinical practice.. Prospective study in 59 consecutive overweight or obese (BMI≥25kg/m(2)) T2DM patients unable to achieve glycemic control (HbA1c>7%, 53mmol/mol) with metformin alone or in association with sulfonylurea that require initiation of liraglutide in progressive dose increase up to 1.8mg/day subcutaneously. Weight, body composition, blood pressure, glucose, HbA1c, C-peptide, insulin, plasma lipids, adipokines (leptin, adiponectin, resistin and visfatin) as well as cardiovascular biomarkers (IL-6 and TNF-a) levels were measured fasting at baseline and 14 weeks after liraglutide initiation.. 14 weeks of liraglutide treatment significantly reduced HbA1c, BMI and total body fat mass by 0.9%, 1.4kg/m(2) and 0.5% respectively. Statistically significant lower insulin resistance and higher insulin secretion was found by HOMA-IR 8.4 (1.6) vs 4.6 (0.9)molmIU/L(2) and HOMA-B 48.2 (9.0) vs 87.6 (16.3)μIU/mmol. Statistically significantly higher levels of visfatin 6.3 (2.1) vs 6.8 (2.1)ng/ml and resistin 3.6 (2.0) vs 4.3 (2.3)ng/ml were also observed after treatment. Baseline visfatin was negatively correlated with basal fasting plasma glucose r=-0.360 (p<0.05).. Liraglutide treatment for 14 weeks in daily clinical practice led to reduction of BMI and improvement of glucose control and insulin sensitivity and resistance parameters. Additionally, circulating levels of adipokines and pro-inflammatory factors could play an important role in GLP-1 treatment response. Topics: Adipokines; Biomarkers; Blood Glucose; Body Weight; Cardiovascular Diseases; Diabetes Mellitus, Type 2; Female; Glucagon-Like Peptide 1; Humans; Hypoglycemic Agents; Insulin Resistance; Liraglutide; Male; Middle Aged; Obesity; Prospective Studies; Risk Factors | 2014 |
Microbiota and epigenetic regulation of inflammatory mediators in type 2 diabetes and obesity.
Metabolic syndrome is associated with alterations in the structure of the gut microbiota leading to low-grade inflammatory responses. An increased penetration of the impaired gut membrane by bacterial components is believed to induce this inflammation, possibly involving epigenetic alteration of inflammatory molecules such as Toll-like receptors (TLRs). We evaluated changes of the gut microbiota and epigenetic DNA methylation of TLR2 and TLR4 in three groups of subjects: type 2 diabetics under glucagon-like peptide-1 agonist therapy, obese individuals without established insulin resistance, and a lean control group. Clostridium cluster IV, Clostridium cluster XIVa, lactic acid bacteria, Faecalibacterium prausnitzii and Bacteroidetes abundances were analysed by PCR and 454 high-throughput sequencing. The epigenetic methylation in the regulatory region of TLR4 and TLR2 was analysed using bisulfite conversion and pyrosequencing. We observed a significantly higher ratio of Firmicutes/ Bacteroidetes in type 2 diabetics compared to lean controls and obese. Major differences were shown in lactic acid bacteria, with the highest abundance in type 2 diabetics, followed by obese and lean participants. In comparison, F. prausnitzii was least abundant in type 2 diabetics, and most abundant in lean controls. Methylation analysis of four CpGs in the first exon of TLR4 showed significantly lower methylation in obese individuals, but no significant difference between type 2 diabetics and lean controls. Methylation of seven CpGs in the promoter region of TLR2 was significantly lower in type 2 diabetics compared to obese subjects and lean controls. The methylation levels of both TLRs were significantly correlated with body mass index. Our data suggest that changes in gut microbiota and thus cell wall components are involved in the epigenetic regulation of inflammatory reactions. An improved diet targeted to induce gut microbial balance and in the following even epigenetic changes of pro-inflammatory genes may be effective in the prevention of metabolic syndrome. Topics: Bacteroidetes; Body Mass Index; Clostridium; Diabetes Mellitus, Type 2; DNA Methylation; Epigenomics; Gastrointestinal Tract; Glucagon-Like Peptide 1; Humans; Inflammation; Inflammation Mediators; Metabolic Syndrome; Microbiota; Obesity; Promoter Regions, Genetic; Toll-Like Receptor 2; Toll-Like Receptor 4 | 2014 |
Gastric bypass increases postprandial insulin and GLP-1 in nonobese minipigs.
Gastric bypass in obese patients induces a dramatic increase of postprandial insulin and glucagon-like peptide-1 (GLP-1) secretion, independently of weight loss. We explored postprandial insulin and GLP-1 secretion in nonobese minipigs before and after RYGB.. Lean adult Göttingen minipigs (n = 7) were submitted to an open gastric bypass surgery mimicking the clinical procedure in humans (30-cm(3) gastric pouch/150-cm alimentary limb/70-cm biliary limb). All animals were evaluated at baseline and then 10 and 30 days after surgery. At each time point, serum glucose, insulin, GLP-1 and D-xylose levels were measured 3 h after a standardized mixed meal.. Weight remained stable during follow-up. Insulin and GLP-1 responses to the test meal were dramatically and similarly increased at 10 days and 1 month after RYGB. Maximal postprandial insulin and GLP-1 levels were 16.3 ± 1.7 mIU/l and 71.7 ± 16.5 pmol/l at baseline, 111.5 ± 38.9 mIU/l and 320.8 ± 84.0 pmol/l at 10 days and 96.6 ± 10.4 mIU/l and 297.3 ± 79.1 pmol/l at 1 month, respectively. D-Xylose absorption remained unchanged before and after surgery.. RYGB induced a dramatic increase of postprandial insulin and GLP-1 secretion in nonobese minipigs. This preclinical model could help to understand the underlying metabolic effects of RYGB, focusing on the role of postsurgical anatomical rearrangement, especially duodenojejunal exclusion and ileal brake. This study supports the use of RYGB in diabetic nonobese patients in absence of obesity. Topics: Animals; Blood Glucose; Diabetes Mellitus, Type 2; Female; Gastric Bypass; Glucagon-Like Peptide 1; Humans; Insulin; Models, Anatomic; Models, Animal; Obesity; Postprandial Period; Swine; Swine, Miniature; Xylose | 2014 |
A novel exendin-4 human serum albumin fusion protein, E2HSA, with an extended half-life and good glucoregulatory effect in healthy rhesus monkeys.
Glucagon-like peptide-1 (GLP-1) has attracted considerable research interest in terms of the treatment of type 2 diabetes due to their multiple glucoregulatory functions. However, the short half-life, rapid inactivation by dipeptidyl peptidase-IV (DPP-IV) and excretion, limits the therapeutic potential of the native incretin hormone. Therefore, efforts are being made to develop the long-acting incretin mimetics via modifying its structure. Here we report a novel recombinant exendin-4 human serum albumin fusion protein E2HSA with HSA molecule extends their circulatory half-life in vivo while still retaining exendin-4 biological activity and therapeutic properties. In vitro comparisons of E2HSA and exendin-4 showed similar insulinotropic activity on rat pancreatic islets and GLP-1R-dependent biological activity on RIN-m5F cells, although E2HSA was less potent than exendin-4. E2HSA had a terminal elimation half-life of approximate 54 h in healthy rhesus monkeys. Furthermore, E2HSA could reduce postprandial glucose excursion and control fasting glucose level, dose-dependent suppress food intake. Improvement in glucose-dependent insulin secretion and control serum glucose excursions were observed during hyperglycemic clamp test (18 h) and oral glucose tolerance test (42 h) respectively. Thus the improved physiological characterization of E2HSA make it a new potent anti-diabetic drug for type 2 diabetes therapy. Topics: Amino Acid Sequence; Animals; Diabetes Mellitus, Type 2; Exenatide; Glucagon-Like Peptide 1; Glucose; Glucose Tolerance Test; Humans; Hypoglycemic Agents; Insulin; Macaca mulatta; Male; Molecular Sequence Data; Peptides; Rats; Rats, Sprague-Dawley; Recombinant Fusion Proteins; Serum Albumin; Serum Albumin, Human; Venoms | 2014 |
Use of antidiabetic drugs in the U.S., 2003-2012.
To describe market trends for antidiabetic drugs, focusing on newly approved drugs, concomitant use of antidiabetic drugs, and effects of safety concerns and access restrictions on thiazolidinedione use.. Nationally projected data on antidiabetic prescriptions for adults dispensed from U.S. retail pharmacies were extracted from IMS Health Vector One National and Total Patient Tracker for 2003-2012 and from Encuity Research Treatment Answers and Symphony Health Solutions PHAST Prescription Monthly for 2012.. Since 2003, the number of adult antidiabetic drug users increased by 42.9% to 18.8 million in 2012. Metformin use increased by 97.0% to 60.4 million prescriptions dispensed in retail pharmacies in 2012. Among antidiabetic drugs newly approved for marketing between 2003 and 2012, the dipeptidyl peptidase-4 (DPP-4) inhibitor sitagliptin had the largest share with 10.5 million prescriptions in 2012. Rosiglitazone use plummeted to <13,000 prescriptions dispensed in retail or mail-order pharmacies in 2012. Concomitancy analyses showed that 44.9% of metformin use was for monotherapy. Between 33.4 and 48.1% of sulfonylurea, DPP-4 inhibitor, thiazolidinedione, and glucagon-like peptide 1 analog use was not accompanied by metformin.. The antidiabetic drug market is characterized by steady increases in volume, and newly approved drugs experienced substantial uptake, especially DPP-4 inhibitors. The use of rosiglitazone has been negligible since restrictions were put in place in 2011. Further study is needed to understand why one-third to one-half of other noninsulin antidiabetic drug use was not concomitant with metformin use despite guidelines recommending that metformin be continued when other agents are added to treatment. Topics: Adult; Diabetes Mellitus, Type 2; Dipeptidyl-Peptidase IV Inhibitors; Drug Prescriptions; Drug Therapy, Combination; Glucagon-Like Peptide 1; Humans; Hypoglycemic Agents; Marketing of Health Services; Metformin; Pharmacies; Prescription Drugs; Pyrazines; Rosiglitazone; Sitagliptin Phosphate; Sulfonylurea Compounds; Thiazolidinediones; Triazoles; United States | 2014 |
The antidiabetic action of camel milk in experimental type 2 diabetes mellitus: an overview on the changes in incretin hormones, insulin resistance, and inflammatory cytokines.
Folk medicine stories accredited the aptitude of camel milk (CMK) as a hypoglycemic agent and recent studies have confirmed this in the diabetic patients and experimental animals. However, the mechanism(s) by which CMK influences glucose homeostasis is yet unclear. The current study investigated the changes in the glucose homeostatic parameters, the incretin hormones, and the inflammatory cytokines in the CMK-treated diabetic animals. A model of type 2 diabetes mellitus was induced in rats by intraperitoneal injection of streptozotocin 40 mg/kg/day for 4 repeated doses. Camel milk treatment was administered for 8 weeks. The changes in glucagon like peptide-1 (GLP-1), glucose dependent insulinotropic peptide (GIP), glucose tolerance, fasting and glucose-stimulated insulin secretion, insulin resistance (IR), TNF-α, TGF-β1, lipid profile, atherogenic index (AI), and body weight were investigated. The untreated diabetic animals showed hyperglycemia, increased HOMA-IR, hyperlipidemia, elevated AI, high serum incretins [GLP-1 and GIP], TNF-α, and TGF-β1 levels and weight loss as compared with the control group. Camel milk treatment to the diabetic animals resulted in significant lowered fasting glucose level, hypolipidemia, decreased HOMA-IR, recovery of insulin secretion, weight gain, and no mortality during the study. Additionally, CMK inhibits the diabetes-induced elevation in incretin hormones, TNF-α and TGF-β1 levels. The increase in glucose-stimulated insulin secretion, decreased HOMA-IR, modulation of the secretion and/or the action of incretins, and the anti-inflammatory effect are anticipated mechanisms to the antidiabetic effect of CMK and suggest it as a valuable adjuvant antidiabetic therapy. Topics: Animals; Atherosclerosis; Blood Glucose; Body Weight; Camelus; Cytokines; Diabetes Mellitus, Experimental; Diabetes Mellitus, Type 2; Fasting; Gastric Inhibitory Polypeptide; Glucagon-Like Peptide 1; Glucose Tolerance Test; Hypoglycemic Agents; Incretins; Inflammation Mediators; Insulin; Insulin Resistance; Lipids; Male; Milk; Rats, Wistar; Transforming Growth Factor beta1; Tumor Necrosis Factor-alpha | 2014 |
Altered pattern of the incretin effect as assessed by modelling in individuals with glucose tolerance ranging from normal to diabetic.
Oral glucose elicits a higher insulin secretory response than intravenous glucose at matched glucose concentrations. This potentiation, known as the incretin effect, is typically expressed as the difference between the total insulin response to oral vs intravenous glucose. This approach does not describe the dynamics of insulin secretion potentiation. We developed a model for the simultaneous analysis of oral and isoglycaemic intravenous glucose responses to dissect the impact of hyperglycaemia and incretin effect on insulin secretion and beta cell function.. Fifty individuals (23 with normal glucose tolerance [NGT], 17 with impaired glucose tolerance [IGT] and ten with type 2 diabetes) received an OGTT and an isoglycaemic test with measurement of plasma glucose, insulin, C-peptide, glucagon-like peptide-1 (GLP-1) and glucose-dependent insulinotropic polypeptide (GIP). Our model featured an incretin potentiation factor (PINCR) for the dose–response function relating insulin secretion to glucose concentration, and an effect on early secretion (rate sensitivity).. In NGT, PINCR rapidly increased and remained sustained during the whole OGTT (mean PINCR>1, p<0.009). The increase was transient in IGT and virtually absent in diabetes. Mean PINCR was significantly but loosely correlated with GLP-1 AUC (r=0.49, p<0.006), while the relationship was not significant for GIP. An incretin effect on rate sensitivity was present in all groups (p<0.002).. The onset of the incretin effect is rapid and sustained in NGT, transient in IGT and virtually absent in diabetes. The profiles of the incretin effect are poorly related to those of the incretin hormones. Topics: Adult; Blood Glucose; C-Peptide; Diabetes Mellitus, Type 2; Female; Gastric Inhibitory Polypeptide; Glucagon-Like Peptide 1; Glucose Intolerance; Glucose Tolerance Test; Humans; Incretins; Insulin; Male; Middle Aged; Models, Theoretical | 2014 |
Prophylactic effects of the glucagon-like Peptide-1 analog liraglutide on hyperglycemia in a rat model of type 2 diabetes mellitus associated with chronic pancreatitis and obesity.
The objective of this study was to investigate the effects of liraglutide, an analog of human glucagon-like peptide 1 (GLP1), on WBN/Kob-Lepr(fa) (fa/fa) rats, which spontaneously develop type 2 diabetes mellitus with pancreatic disorder and obesity. Male fa/fa rats (age, 7 wk) were allocated into 4 groups and received liraglutide (37.5, 75, 150 μg/kg SC) or saline (control group) once daily for 4 wk. All rats in the control group became overweight and developed hyperglycemia as they aged. Although the rats given liraglutide showed a dose-dependent reduction in food intake, no significant effects on body weight or fat content occurred. In the liraglutide groups, the development of hyperglycemia was suppressed, even as plasma insulin concentrations increased in a dose-dependent manner. Intravenous glucose tolerance testing of the liraglutide-treated rats confirmed improvement of glucose tolerance and enhanced insulin secretion. Histologic examination revealed increased numbers of pancreatic β-cell type islet cells and increased proliferation of epithelial cells of the small ducts in the liraglutide-treated groups. Although our study did not reveal a significant decrease in obesity after liraglutide administration, the results suggest a marked antidiabetic effect characterized by increased insulin secretion in fa/fa rats with pancreatic disorders. Topics: Adiposity; Age Factors; Animals; Body Weight; Diabetes Mellitus, Type 2; Disease Models, Animal; Dose-Response Relationship, Drug; Glucagon-Like Peptide 1; Hyperglycemia; Insulin; Liraglutide; Male; Obesity; Pancreatitis, Chronic; Pre-Exposure Prophylaxis; Rats | 2014 |
Incretin effect and glucagon responses to oral and intravenous glucose in patients with maturity-onset diabetes of the young--type 2 and type 3.
Maturity-onset diabetes of the young (MODY) is a clinically and genetically heterogeneous subgroup of nonautoimmune diabetes, constituting 1-2% of all diabetes. Because little is known about incretin function in patients with MODY, we studied the incretin effect and hormone responses to oral and intravenous glucose loads in patients with glucokinase (GCK)-diabetes (MODY2) and hepatocyte nuclear factor 1α (HNF1A)-diabetes (MODY3), respectively, and in matched healthy control subjects. Both MODY groups exhibited glucose intolerance after oral glucose (most pronounced in patients with HNF1A-diabetes), but only patients with HNF1A-diabetes had impaired incretin effect and inappropriate glucagon responses to OGTT. Both groups of patients with diabetes showed normal suppression of glucagon in response to intravenous glucose. Thus, HNF1A-diabetes, similar to type 2 diabetes, is characterized by an impaired incretin effect and inappropriate glucagon responses, whereas incretin effect and glucagon response to oral glucose remain unaffected in GCK-diabetes, reflecting important pathogenetic differences between the two MODY forms. Topics: Administration, Intravenous; Administration, Oral; Adult; Diabetes Mellitus, Type 2; Female; Gastric Emptying; Gastric Inhibitory Polypeptide; Gene Expression Regulation; Glucagon; Glucagon-Like Peptide 1; Glucokinase; Glucose; Hepatocyte Nuclear Factor 1-alpha; Humans; Incretins; Insulin Resistance; Male; Middle Aged | 2014 |
Effects of treatment with liraglutide on oxidative stress and cardiac natriuretic peptide levels in patients with type 2 diabetes mellitus.
Topics: Aged; Diabetes Mellitus, Type 2; Female; Glucagon-Like Peptide 1; Humans; Hypoglycemic Agents; Liraglutide; Male; Middle Aged; Natriuretic Peptide, C-Type; Oxidative Stress | 2014 |
Small intestinal glucose exposure determines the magnitude of the incretin effect in health and type 2 diabetes.
The potential influence of gastric emptying on the "incretin effect," mediated by glucose-dependent insulinotropic polypeptide (GIP) and glucagon-like peptide-1 (GLP-1), is unknown. The objectives of this study were to determine the effects of intraduodenal (ID) glucose infusions at 2 (ID2) and 4 (ID4) kcal/min (equating to two rates of gastric emptying within the physiological range) on the size of the incretin effect, gastrointestinal glucose disposal (GIGD), plasma GIP, GLP-1, and glucagon secretion in health and type 2 diabetes. We studied 10 male BMI-matched controls and 11 male type 2 patients managed by diet or metformin only. In both groups, GIP, GLP-1, and the magnitude of incretin effect were greater with ID4 than ID2, as was GIGD; plasma glucagon was suppressed by ID2, but not ID4. There was no difference in the incretin effect between the two groups. Based on these data, we conclude that the rate of small intestinal glucose exposure (i.e., glucose load) is a major determinant of the comparative secretion of GIP and GLP-1, as well as the magnitude of the incretin effect and GIGD in health and type 2 diabetes. Topics: Animals; Blood Glucose; Body Mass Index; C-Peptide; Case-Control Studies; Diabetes Mellitus, Type 2; Gastric Inhibitory Polypeptide; Gene Expression Regulation; Glucagon; Glucagon-Like Peptide 1; Glucose; Humans; Incretins; Insulin; Male | 2014 |
GLP-1 receptor agonists: why is once weekly inferior to once daily?
Topics: Diabetes Mellitus, Type 2; Female; Glucagon-Like Peptide 1; Humans; Hypoglycemic Agents; Liraglutide; Male | 2014 |
Deletion of hypoxia-inducible factor-1α in adipocytes enhances glucagon-like peptide-1 secretion and reduces adipose tissue inflammation.
It is known that obese adipose tissues are hypoxic and express hypoxia-inducible factor (HIF)-1α. Although some studies have shown that the expression of HIF-1α in adipocytes induces glucose intolerance, the mechanisms are still not clear. In this study, we examined its effects on the development of type 2 diabetes by using adipocyte-specific HIF-1α knockout (ahKO) mice. ahKO mice showed improved glucose tolerance compared with wild type (WT) mice. Macrophage infiltration and mRNA levels of monocyte chemotactic protein-1 (MCP-1) and tumor necrosis factor α (TNFα) were decreased in the epididymal adipose tissues of high fat diet induced obese ahKO mice. The results indicated that the obesity-induced adipose tissue inflammation was suppressed in ahKO mice. In addition, in the ahKO mice, serum insulin levels were increased under the free-feeding but not the fasting condition, indicating that postprandial insulin secretion was enhanced. Serum glucagon-like peptide-1 (GLP-1) levels were also increased in the ahKO mice. Interestingly, adiponectin, whose serum levels were increased in the obese ahKO mice compared with the obese WT mice, stimulated GLP-1 secretion from cultured intestinal L cells. Therefore, insulin secretion may have been enhanced through the adiponectin-GLP-1 pathway in the ahKO mice. Our results suggest that the deletion of HIF-1α in adipocytes improves glucose tolerance by enhancing insulin secretion through the GLP-1 pathway and by reducing macrophage infiltration and inflammation in adipose tissue. Topics: Adipocytes; Animals; Blotting, Western; Chemokine CCL2; Diabetes Mellitus, Type 2; DNA Primers; Gene Deletion; Glucagon-Like Peptide 1; Glucose Tolerance Test; Hypoxia-Inducible Factor 1, alpha Subunit; Immunohistochemistry; Insulin; Insulin Secretion; Mice; Mice, Knockout; Real-Time Polymerase Chain Reaction; Tumor Necrosis Factor-alpha | 2014 |
Active glucagon-like peptide 1 quantitation in human plasma: a comparison of multiple ligand binding assay platforms.
There are a wide variety of ligand binding assay platforms available for implementation in present day bioanalytical laboratories. Selecting the platform that best suits a particular project's needs is highly dependent upon multiple assay characteristics. The active form of glucagon-like protein (GLP-1) is a biomarker of interest for type 2 diabetes (T2DM), and therefore a common target for quantitation. Previous projects requiring active GLP-1 measurements involved the use of a labor intensive ELISA, spurring an investigation towards other potential assay platforms. To that end, four separate ligand binding assay formats (standard ELISA, electrochemiluminescence, Gyrolab, and Singulex) were evaluated. The platforms were compared for numerous assay parameters including dynamic range, sample volume requirements, throughput, and cost. Additionally, thirty individual donor plasmas were run with each assay as representative study samples. Although our evaluation did not show any platform that was better than others in all assay characteristics, there was one that was best in sensitivity (Singulex) and one that was best in throughput and sample volume requirements (Gyrolab). The lack of a technology that was best in all categories underscores the importance of due diligence when selecting an assay platform; there are no silver bullets, and one must take into account what is necessary for project needs and the intended use of the data. Topics: Biomarkers; Cost-Benefit Analysis; Diabetes Mellitus, Type 2; Electrochemical Techniques; Enzyme-Linked Immunosorbent Assay; Glucagon-Like Peptide 1; Humans; Immunosorbent Techniques; Ligands; Luminescent Measurements; Sensitivity and Specificity | 2014 |
Duodenal-Jejunal bypass improves glucose homeostasis in association with decreased proinflammatory response and activation of JNK in the liver and adipose tissue in a T2DM rat model.
There is accumulating evidence that obesity leads to a proinflammatory state, which plays crucial roles in insulin resistance and development of type 2 diabetes mellitus (T2DM). Previous studies demonstrated that weight loss after bariatric surgery was accompanied by a suppression of the proinflammatory state. However, the effect of bariatric surgery on the proinflammatory state and associated signaling beyond weight loss is still elusive. The objective of this study was to investigate the effect of duodenal-jejunal bypass (DJB) on glucose homeostasis, the proinflammatory state and the involving signaling independently of weight loss.. A high-fat diet and low-dose streptozotocin administration were used to induce T2DM in male Sprague-Dawley rats. The diabetic rats underwent DJB or sham surgery. The blood glucose, glucose tolerance and insulin resistance were determined to evaluate the glucose homeostasis. Serum insulin, GLP-1 and hsCRP were detected by ELISA. The gene expression of TNF-α, IL-6, IL-1β and MCP-1 in liver and fat was determined by quantitative real-time RT-PCR. The JNK activity and serine phosphorylation of IRS-1 in liver and adipose tissue were determined by Western blotting.. Compared to the S-DJB group, DJB induced significant and sustained glycemic control with improved insulin sensitivity and glucose tolerance independently of weight loss. DJB improved the proinflammatory state indicated by decreased circulating hsCRP and proinflammatory gene expression in the liver and adipose tissue. The JNK activity and serine phosphorylation of IRS-1 in liver and adipose tissue were significantly reduced after DJB.. DJB achieved a rapid and sustainable glycemic control independently of weight loss. The data indicated that the improved proinflammatory state and decreased JNK activity after DJB may contribute to the improved glucose homeostasis. Topics: Adipose Tissue; Animals; Blood Glucose; Chemokine CCL2; Diabetes Mellitus, Experimental; Diabetes Mellitus, Type 2; Disease Models, Animal; Duodenum; Gastric Bypass; Glucagon-Like Peptide 1; Insulin Receptor Substrate Proteins; Insulin Resistance; Interleukins; Jejunum; Liver; Male; MAP Kinase Signaling System; Rats; Rats, Sprague-Dawley; Tumor Necrosis Factor-alpha; Weight Loss | 2014 |
Basal insulin or longacting GLP-1 receptor agonists-making the right choice.
Topics: Blood Glucose; Diabetes Mellitus, Type 2; Exenatide; Female; Glucagon-Like Peptide 1; Humans; Hypoglycemic Agents; Insulin Glargine; Insulin, Long-Acting; Male; Peptides; Venoms | 2014 |
Liraglutide-induced autoimmune hepatitis.
Use of incretin-based hypoglycemic agents is increasing, but safety data remain limited. We treated a woman with marker-negative autoimmune hepatitis associated with the glucagon-like peptide 1 agonist liraglutide.. A young woman with type 2 diabetes mellitus and vitiligo presented with a 10-day history of acute hepatitis. Other than starting liraglutide therapy 4 months prior, she reported no changes in medication therapy and no use of supplements. At admission, aspartate aminotransferase level was 991 U/L; alanine aminotransferase level, 1123 U/L; total bilirubin level, 9.5 mg/dL; and international normalized ratio, 1.3. Results of a liver biopsy demonstrated interface hepatitis with prominent eosinophils and rare plasma cells. The patient's liraglutide therapy was withheld at discharge but her symptoms worsened. A second biopsy specimen revealed massive hepatic necrosis. She started oral prednisone therapy for presumed liraglutide-induced marker-negative autoimmune hepatitis.. This case represents, to our knowledge, the first report of liraglutide-induced autoimmune hepatitis. Hepatotoxicity may be an incretin analogue class effect with a long latency period. This case raises prescriber awareness about the potential adverse effects of glucagon-like peptide 1 agonists. Postmarketing studies are needed to define the hepatotoxic potential of these agents. Topics: Diabetes Complications; Diabetes Mellitus, Type 2; Female; Glucagon-Like Peptide 1; Hepatitis, Autoimmune; Humans; Incretins; Liraglutide; Liver; Young Adult | 2014 |
ADCY5 couples glucose to insulin secretion in human islets.
Single nucleotide polymorphisms (SNPs) within the ADCY5 gene, encoding adenylate cyclase 5, are associated with elevated fasting glucose and increased type 2 diabetes (T2D) risk. Despite this, the mechanisms underlying the effects of these polymorphic variants at the level of pancreatic β-cells remain unclear. Here, we show firstly that ADCY5 mRNA expression in islets is lowered by the possession of risk alleles at rs11708067. Next, we demonstrate that ADCY5 is indispensable for coupling glucose, but not GLP-1, to insulin secretion in human islets. Assessed by in situ imaging of recombinant probes, ADCY5 silencing impaired glucose-induced cAMP increases and blocked glucose metabolism toward ATP at concentrations of the sugar >8 mmol/L. However, calcium transient generation and functional connectivity between individual human β-cells were sharply inhibited at all glucose concentrations tested, implying additional, metabolism-independent roles for ADCY5. In contrast, calcium rises were unaffected in ADCY5-depleted islets exposed to GLP-1. Alterations in β-cell ADCY5 expression and impaired glucose signaling thus provide a likely route through which ADCY5 gene polymorphisms influence fasting glucose levels and T2D risk, while exerting more minor effects on incretin action. Topics: Adenylyl Cyclases; Calcium; Diabetes Mellitus, Type 2; Glucagon-Like Peptide 1; Glucose; Humans; Insulin; Insulin Secretion; Insulin-Secreting Cells; Polymorphism, Single Nucleotide; Risk; RNA, Messenger | 2014 |
Diabetes, incretin hormones and cardioprotection.
Topics: Animals; Blood Glucose; Cardiotonic Agents; Clinical Trials, Phase II as Topic; Delayed Diagnosis; Diabetes Mellitus, Type 2; Dipeptidyl-Peptidase IV Inhibitors; Global Health; Glucagon-Like Peptide 1; Glucagon-Like Peptide-1 Receptor; Heart Diseases; Humans; Hypoglycemic Agents; Incretins; Models, Animal; Receptors, Glucagon | 2014 |
A nondigestible saccharide, fructooligosaccharide, increases the promotive effect of a flavonoid, α-glucosyl-isoquercitrin, on glucagon-like peptide 1 (GLP-1) secretion in rat intestine and enteroendocrine cells.
This study conducted in vivo and in situ experiments with rats to investigate the glucagon-like peptide-1 (GLP-1) secretion in response to oral or ileal administration of α-glucosyl-isoquercitrin (20-40 mmol in 2 mL; Q3G), fructooligosaccharides (200 mmol in 2 mL; FOS) and Q3G + FOS. Direct effects on GLP-1-producing l-cells were also examined by an in vitro study using a murine enteroendocrine cell line, GLUTag. To evaluate the plasma GLP-1 level, blood samples from jugular cannula for in vivo and portal cannula for in situ experiments were obtained before and after administration of Q3G, FOS, or Q3G + FOS. We found tendencies for increases but transient stimulation of GLP-1 secretion by Q3G in in vivo and in situ experiments. Although FOS alone did not have any effects, Q3G + FOS enhanced and prolonged high plasma GLP-1 level in both experiments. In addition, application of Q3G on GLUTag cells stimulated GLP-1 secretion while FOS enhanced the effect of Q3G. Our results suggest that Q3G + FOS possess the potential for the management or prevention of Type 2 diabetes mellitus (T2DM) by enhancing and prolonging the GLP-1 secretion via direct stimulation of GLP-1 producing l-cell. Topics: Animals; Cell Line; Diabetes Mellitus, Type 2; Enteroendocrine Cells; Glucagon-Like Peptide 1; Ileum; Male; Oligosaccharides; Quercetin; Rats; Rats, Wistar | 2014 |
Biliopancreatic diversion with duodenal switch improves insulin sensitivity and secretion through caloric restriction.
To assess the rapid improvement of insulin sensitivity and β-cell function following biliopancreatic diversion with duodenal switch (BPD-DS) and determine the role played by caloric restriction in these changes.. Standard meals were administrated before and on day 3, 4, and 5 after BPD-DS to measure total caloric intake, glucose excursion, insulin sensitivity, and secretion in matched type 2 diabetes and normoglycemic (NG) subjects. In a second set of study, other subjects with type 2 diabetes had the same meal tests prior to and after a 3-day caloric restriction identical to that observed after BPD-DS and then 3 days after actually undergoing BPD-DS.. Improvement of HOMA-IR occurred at day 3 after BPD-DS in diabetes and after 3 days of caloric restriction. The disposition index (DI) improved rapidly in diabetes after BPD-DS and to a similar extent after caloric restriction. DI was higher and did not change after BPD-DS in NG. Changes in glucagon-like peptide-1, gastric inhibitory peptide, peptide tyrosine tyrosine, ghrelin, and pancreatic polypeptide levels were not associated with modulation of DI in the participants.. Caloric restriction is the major mechanism underlying the early improvement of insulin sensitivity and β-cell function after BPD-DS in type 2 diabetes. Topics: Adult; Biliopancreatic Diversion; Blood Glucose; Caloric Restriction; Diabetes Mellitus, Type 2; Duodenum; Female; Gastric Inhibitory Polypeptide; Ghrelin; Glucagon-Like Peptide 1; Glucose Tolerance Test; Humans; Insulin; Insulin Resistance; Insulin Secretion; Insulin-Secreting Cells; Male; Middle Aged; Obesity, Morbid; Peptide YY; Pilot Projects | 2014 |
The safety of incretin based drugs.
Topics: Diabetes Mellitus, Type 2; Dipeptidyl-Peptidase IV Inhibitors; Female; Glucagon-Like Peptide 1; Humans; Hypoglycemic Agents; Incretins; Male; Pancreatitis | 2014 |
Incretin based drugs and risk of acute pancreatitis in patients with type 2 diabetes: cohort study.
To determine whether the use of incretin based drugs, compared with sulfonylureas, is associated with an increased risk of acute pancreatitis.. Population based cohort study.. 680 general practices in the United Kingdom contributing to the Clinical Practice Research Datalink.. From 1 January 2007 to 31 March 2012, 20 748 new users of incretin based drugs were compared with 51 712 users of sulfonylureas and followed up until 31 March 2013.. Cox proportional hazards models were used to estimate hazard ratios and 95% confidence intervals for acute pancreatitis in users of incretin based drugs compared with users of sulfonylureas. Models were adjusted for tenths of high dimensional propensity score (hdPS).. The crude incidence rate for acute pancreatitis was 1.45 per 1000 patients per year (95% confidence interval 0.99 to 2.11) for incretin based drug users and 1.47 (1.23 to 1.76) for sulfonylurea users. The rate of acute pancreatitis associated with the use of incretin based drugs was not increased (hdPS adjusted hazard ratio: 1.00, 95% confidence interval 0.59 to 1.70) relative to sulfonylurea use.. Compared with use of sulfonylureas, the use of incretin based drugs is not associated with an increased risk of acute pancreatitis. While this study is reassuring, it does not preclude a modest increased risk, and thus additional studies are needed to confirm these findings. Topics: Acute Disease; Diabetes Mellitus, Type 2; Dipeptidyl-Peptidase IV Inhibitors; Female; Follow-Up Studies; Glucagon-Like Peptide 1; Humans; Hypoglycemic Agents; Incretins; Kaplan-Meier Estimate; Male; Middle Aged; Pancreatitis; Sulfonylurea Compounds | 2014 |
Impact of the hepatic branch of the vagus and Roux-en-Y gastric bypass on the hypoglycemic effect and glucagon-like peptide-1 in rats with type 2 diabetes mellitus.
The impact of the hepatic branch of the vagus and Roux-en-Y gastric bypass (RYGB) on the hypoglycemic effect and glucagon-like peptide-1 (GLP-1) in rats with type 2 diabetes mellitus (T2DM) was investigated, and interactions were preliminarily analyzed.. A total of 45 rats with T2DM were divided into four groups: sham operation (S, n = 10), sham operation with the hepatic branch of the vagus resected (SV, n = 11), RYGB (n = 12), and RYGB without preservation of the vagus (RYGBV, n = 12). Body mass, fasting blood glucose (FBG), fasting serum insulin, and concentrations of fasting serum GLP-1 were examined in the first, second, fourth, and eighth week before and after surgery. The effects of RYGB and the hepatic branch of the vagus on GLP-1 levels in the eighth postoperative week were also analyzed.. RYGB caused a significant reduction in the weight of rats with T2DM (P < 0.05), improved the levels of serum GLP-1 and insulin (P < 0.05), and decreased FBG level (P < 0.05). Retention of the hepatic branch of the vagus maintained weight reduction for a longer period (P < 0.05) and increased the levels of serum GLP-1 and insulin (P < 0.05), but had no impact on FBG level (P > 0.05).. RYGB had better therapeutic efficacy in rats with T2DM. Care should be taken during RYGB surgery to preserve the hepatic branch of the vagus. Topics: Animals; Blood Glucose; Diabetes Mellitus, Experimental; Diabetes Mellitus, Type 2; Disease Models, Animal; Gastric Bypass; Glucagon-Like Peptide 1; Hypoglycemia; Insulin; Liver; Male; Obesity; Postoperative Period; Rats, Sprague-Dawley; Vagotomy; Vagus Nerve; Weight Loss | 2014 |
Pharmacokinetics, pharmacodynamics, and cytotoxicity of recombinant orally-administrated long-lasting GLP-1 and its therapeutic effect on db/db mice.
Recombinant orally long-acting glucagon-like peptide 1 (rolGLP-1), a novel analog of native GLP-1 that can stimulate insulin secretion, was constructed via site-directed mutagenesis by our laboratory. This study was designed to investigate the pharmacokinetics, pharmacodynamics, and the cytotoxicity of rolGLP-1. Diabetic db/db mice were given 125I-rolGLP-1 through a single dose of oral administration to evaluate the pharmacokinetics of rolGLP-1 by trichloroacetic acid-Radioactive assay (TCA-RA). Separately, rolGLP-1 was orally administered to the db/db mice daily for 28 days to evaluate its therapeutic effect. In addition, the safety of rolGLP-1 was assessed based on cytotoxicity testing on the cell line SH-SY5Y by both the MTT assay and the cell counts method. The results showed that the half-life of rolGLP-1 in db/db mice was 68.2 h, which is longer than that of native GLP-1. Results after the 28 day treatment showed glucose homeostasis was improved. Furthermore, rolGLP-1 was also proved to mitigate insulin resistance, alleviate hyperinsulinemia and decreased glycosylated hemoglobin content. Lastly, no visible adverse events were observed in cytotoxicity treatments on SH-SY5Y. Our results revealed that oral administration of rolGLP-1 harbored a longer half-life and a good therapeutic effect for type 2 db/db mice. All the results suggest the capacity and safety of rolGLP-1 for further use as an anti-diabetic agent for type 2 diabetes.This study was supported by Project 863 of China (2008AA02Z205). Topics: Administration, Oral; Animals; Area Under Curve; Biological Availability; Blood Glucose; Cell Line, Tumor; Cell Survival; Diabetes Mellitus, Type 2; Feces; Female; Glucagon-Like Peptide 1; Half-Life; Humans; Hypoglycemic Agents; Male; Mice, Inbred C57BL; Mice, Inbred NOD; Recombinant Proteins; Tissue Distribution | 2014 |
Sitagliptin prevents inflammation and apoptotic cell death in the kidney of type 2 diabetic animals.
This study aimed to evaluate the efficacy of sitagliptin, a dipeptidyl peptidase IV (DPP-IV) inhibitor, in preventing the deleterious effects of diabetes on the kidney in an animal model of type 2 diabetes mellitus; the Zucker diabetic fatty (ZDF) rat: 20-week-old rats were treated with sitagliptin (10 mg/kg bw/day) during 6 weeks. Glycaemia and blood HbA1c levels were monitored, as well as kidney function and lesions. Kidney mRNA and/or protein content/distribution of DPP-IV, GLP-1, GLP-1R, TNF-α, IL-1β, BAX, Bcl-2, and Bid were evaluated by RT-PCR and/or western blotting/immunohistochemistry. Sitagliptin treatment improved glycaemic control, as reflected by the significantly reduced levels of glycaemia and HbA1c (by about 22.5% and 1.2%, resp.) and ameliorated tubulointerstitial and glomerular lesions. Sitagliptin prevented the diabetes-induced increase in DPP-IV levels and the decrease in GLP-1 levels in kidney. Sitagliptin increased colocalization of GLP-1 and GLP-1R in the diabetic kidney. Sitagliptin also decreased IL-1β and TNF-α levels, as well as, prevented the increase of BAX/Bcl-2 ratio, Bid protein levels, and TUNEL-positive cells which indicates protective effects against inflammation and proapoptotic state in the kidney of diabetic rats, respectively. In conclusion, sitagliptin might have a major role in preventing diabetic nephropathy evolution due to anti-inflammatory and antiapoptotic properties. Topics: Animals; Apoptosis; Diabetes Mellitus, Experimental; Diabetes Mellitus, Type 2; Dipeptidyl-Peptidase IV Inhibitors; Glucagon-Like Peptide 1; Inflammation; Kidney; Pyrazines; Rats; Rats, Zucker; Sitagliptin Phosphate; Triazoles; Tumor Necrosis Factor-alpha | 2014 |
Albiglutide approved for type 2 diabetes.
Topics: Diabetes Mellitus, Type 2; Drug Approval; Glucagon-Like Peptide 1; Humans; Hypoglycemic Agents | 2014 |
Obesity associated with type 2 diabetes mellitus is linked to decreased PC1/3 mRNA expression in the Jejunum.
Bariatric surgery is the most effective therapeutic option for obesity and its complications, especially in type 2 diabetes. The aim of this study was to investigate the messenger RNA (mRNA) gene expression of proglucagon, glucose-dependent insulinotropic peptide (GIP), prohormone convertase 1/3 (PC1/3), and dipeptidyl peptidase-IV (DPP-IV) in jejunum cells of the morbidly obese (OB) non type 2 diabetes mellitus (NDM2) and type 2 diabetes mellitus (T2DM), to determine the molecular basis of incretin secretion after bariatric surgery.. Samples of jejunal mucosa were obtained from 20 NDM2 patients: removal of a section of the jejunum about 60 cm distal to the ligament of Treitz and 18 T2DM patients: removal of a section of the jejunum about 100 cm distal to the ligament of Treitz. Total RNA was extracted using TRIzol. Reverse transcription quantitative real-time polymerase chain reaction (RT-qPCR) was carried out. Samples were sequenced to PC1/3 by ACTGene Análises Moleculares Ltd. Immuno content was quantified with a fluorescence microscope.. T2DM showed decreased PC1/3 mRNA expression in the primers tested (primer a, p=0.014; primer b, p=0.048). Many patients (36.5 %) did not express PC1/3 mRNA. NDM2 and T2DM subjects showed nonsignificantly different proglucagon, GIP, and DPP-IV mRNA expression. The immuno contents of glucagon-like peptide-1 and GIP decreased in T2DM jejunum, but incubation with high glucose stimulated the immuno contents.. The results suggest that bioactivation of pro-GIP and proglucagon could be impaired by the lower expression of PC1/3 mRNA in jejunum cells of obese patients with T2DM. However, after surgery, food could activate this system and improve glucose levels in these patients. Topics: Adult; Case-Control Studies; Diabetes Mellitus, Type 2; Dipeptidyl Peptidase 4; Female; Gastric Inhibitory Polypeptide; Gene Expression Regulation; Glucagon-Like Peptide 1; Humans; Jejunum; Male; Middle Aged; Obesity, Morbid; Proprotein Convertase 1; Real-Time Polymerase Chain Reaction; RNA, Messenger | 2014 |
Deterioration of plasticity and metabolic homeostasis in the brain of the UCD-T2DM rat model of naturally occurring type-2 diabetes.
The rising prevalence of type-2 diabetes is becoming a pressing issue based on emerging reports that T2DM can also adversely impact mental health. We have utilized the UCD-T2DM rat model in which the onset of T2DM develops spontaneously across time and can serve to understand the pathophysiology of diabetes in humans. An increased insulin resistance index and plasma glucose levels manifested the onset of T2DM. There was a decrease in hippocampal insulin receptor signaling in the hippocampus, which correlated with peripheral insulin resistance index along the course of diabetes onset (r=-0.56, p<0.01). T2DM increased the hippocampal levels of 4-hydroxynonenal (4-HNE; a marker of lipid peroxidation) in inverse proportion to the changes in the mitochondrial regulator PGC-1α. Disrupted energy homeostasis was further manifested by a concurrent reduction in energy metabolic markers, including TFAM, SIRT1, and AMPK phosphorylation. In addition, T2DM influenced brain plasticity as evidenced by a significant reduction of BDNF-TrkB signaling. These results suggest that the pathology of T2DM in the brain involves a progressive and coordinated disruption of insulin signaling, and energy homeostasis, with profound consequences for brain function and plasticity. All the described consequences of T2DM were attenuated by treatment with the glucagon-like peptide-1 receptor agonist, liraglutide. Similar results to those of liraglutide were obtained by exposing T2DM rats to a food energy restricted diet, which suggest that normalization of brain energy metabolism is a crucial factor to counteract central insulin sensitivity and synaptic plasticity associated with T2DM. Topics: Aldehydes; Animals; Biomarkers; Blood Glucose; Brain; Crosses, Genetic; Diabetes Mellitus, Type 2; Disease Models, Animal; Energy Metabolism; Glucagon-Like Peptide 1; Hippocampus; Homeostasis; Hypoglycemic Agents; Immunoblotting; Insulin Resistance; Liraglutide; Male; Neuronal Plasticity; Obesity; Rats; Rats, Sprague-Dawley; Rats, Zucker; Receptor, Insulin | 2014 |
GLP-1 and glucose tolerance after sleeve gastrectomy in morbidly obese subjects with type 2 diabetes.
Although GLP-1 has been suggested as a major factor for the marked improvement of glucose tolerance commonly seen after sleeve gastrectomy (SG), several observations challenge this hypothesis. To better understand the role of GLP-1 in the remission of type 2 diabetes mellitus (T2DM) long term after SG in humans, we conducted two separate cross-sectional studies: 1) the GLP-1 response to a standardized mixed liquid meal (SMLM) was compared in subjects with T2DM antedating SG but with different long-term (>2 years) T2DM outcomes (remission, relapse, or lack of remission) (study 1) and 2) the effect of GLP-1 receptor blockade with exendin (9-39) on glucose tolerance was examined in subjects with T2DM antedating surgery, who had undergone SG and presented with long-term T2DM remission (study 2). In study 1, we observed a comparable GLP-1 response to the SMLM regardless of the post-SG outcome of T2DM. In study 2, the blockade of GLP-1 action resulted in impaired insulin secretion but limited deterioration of glucose tolerance. Thus, our data suggest the enhanced GLP-1 secretion observed long term after SG is neither sufficient nor critical to maintain normal glucose tolerance in subjects with T2DM antedating the surgery. Topics: Adult; Aged; Blood Glucose; Case-Control Studies; Cross-Sectional Studies; Diabetes Mellitus, Type 2; Female; Gastrectomy; Glucagon-Like Peptide 1; Glucose Tolerance Test; Humans; Male; Middle Aged; Obesity, Morbid | 2014 |
Albiglutide: first global approval.
Albiglutide (Eperzan® [EU]; Tanzeum™ [US]), a glucagon-like peptide 1 receptor agonist, has been developed by GlaxoSmithKline for the treatment of type 2 diabetes mellitus (T2DM). Albiglutide has received its first global approval in this indication in the EU, for use in combination with other antihyperglycaemic agents, including basal insulin, when these drugs and diet and exercise do not provide adequate glycaemic control, and as monotherapy in patients unable to take metformin due to contraindications or intolerance when diet and exercise alone do not provide adequate glycaemic control. Albiglutide has subsequently been approved for the second-line or later treatment of T2DM as an adjunct to diet and exercise in the US. This article summarizes the milestones in the development of albiglutide leading to this first approval for the treatment of T2DM. Topics: Animals; Diabetes Mellitus, Type 2; Drug Approval; Drug Therapy, Combination; Glucagon-Like Peptide 1; Glucagon-Like Peptide-1 Receptor; Humans; Hypoglycemic Agents; Receptors, Glucagon | 2014 |
Glucose tolerance test before and after gastroplasty. Is it a secure measurement?
Topics: Blood Glucose; Diabetes Mellitus, Type 2; Female; Gastroplasty; Glucagon-Like Peptide 1; Humans; Laparoscopy; Obesity, Morbid; Triglycerides; Weight Loss | 2014 |
Reply to letter to the editor by dr. Dimitrios tsamis.
Topics: Blood Glucose; Diabetes Mellitus, Type 2; Female; Gastroplasty; Glucagon-Like Peptide 1; Humans; Laparoscopy; Obesity, Morbid; Triglycerides; Weight Loss | 2014 |
Long-term tolerance and efficacy of adjunctive exenatide therapy on glycaemic control and bodyweight in type 2 diabetes: a retrospective study from a specialist diabetes outpatient clinic.
Weight gain and hypoglycaemia are common adverse effects associated with anti-diabetic treatments.. Our aim was to evaluate the long-term effects of adjunctive exenatide therapy on weight loss and glycaemic control in patients with type 2 diabetes.. A review of medical records in a specialist diabetes clinic over 5 years identified 446 patients who were prescribed exenatide therapy. We examined change in glycosylated haemoglobin (HbA1c), weight, albumin-creatinine ratio and hypoglycaemic medication during 24 months follow up.. Subjects were aged 59 ± 10 years (49% women) and received exenatide in combination with oral agents and insulin (47%). During an average of 17 ± 14 months follow up, 51% (more women than men; odds ratio 1.69, 95% confidence interval 1.14–2.49) remained on treatment. Lack of efficacy (33%) and/or gastrointestinal (27%) side-effects were the main reasons for treatment cessation. At 24 months, there was a reduction in HbA1c of 0.7 ± 1.2% and weight loss of 4.3 ± 5.2 kg. Change in HbA1c was similar regardless of concurrent insulin therapy, yet insulin was associated with greater weight reduction (4.8 ± 5.3 vs 3.8 ± 5.1 kg, P = 0.016). Independent predictors of HbA1c response were higher baseline HbA1c, longer duration of diabetes and use of insulin or sulfonylureas at study end. Predictors of weight response were baseline use of insulin or thiazolidinediones, increased age, female sex and sulfonylurea or thiazolidinediones at study end. Longer exenatide treatment duration was favourable for reducing HbA1c and weight.. Exenatide is effective in reducing HbA1c and weight, regardless of concurrent insulin, and in a specialist diabetes outpatient clinic, is recommended for use in clinical practice. Topics: Ambulatory Care Facilities; Blood Glucose; Body Weight; Diabetes Mellitus, Type 2; Dose-Response Relationship, Drug; Drug Tolerance; Exenatide; Female; Follow-Up Studies; Glucagon-Like Peptide 1; Glycated Hemoglobin; Humans; Hypoglycemic Agents; Male; Middle Aged; Peptides; Retrospective Studies; Time Factors; Treatment Outcome; Venoms | 2014 |
Ileal effect on blood glucose, HbA1c, and GLP-1 in Goto-Kakizaki rats.
There have been enumerable studies on the effects of glucagon-like peptide-1 (GLP-1) on satiety and pancreatic islet function, stimulating the advocacy of surgical transposition of the ileum (rich in GLP-1-generating L-cells) higher in the gastrointestinal tract for earlier stimulation. In the Goto-Kakizaki rat with naturally occurring type 2 diabetes, we studied the influence of ileal exclusion (IE) and ileal resection (IR) on blood glucose, hemoglobin A1c (HbA1c), and GLP-1.. In six control (Ctrl), 10 IE, and 10 IR rats, over 12 weeks of follow-up, we determined blood glucose, HbA1c, and GLP-1.. Two animals in the IE and IR groups did not survive to week 13. Both operated groups weighed more than the Ctrl group at baseline and at 13 weeks; thus, IE and IR did not retard weight gain (p < 0.05). All three groups were equally hyperglycemic at week 13: 255 ± 10.2 Ctrl, 262 ± 11.0 IE, 292 ± 17.8 IR (mg/dl ± SEM). The three groups had statistically identical markedly elevated HbA1c percentages at week 13: 14.7 ± 28 Ctrl, 11.7 ± 3.4 IE, 13.8 ± 3.5 IR (% ± SEM). The end-study GLP-1 values (pM ± SEM) were 5 ± 0.9 Ctrl, 33 ± 8.9 IE, and 25 ± 6.7 IR. P values for intergroup differences were IE vs. Ctrl 0.02, IR vs. Ctrl 0.02, and IE vs. IR 0.59.. Neither IE nor IR resulted in a decrease in the mean GLP-1 level. On the contrary, the exclusion or resection of the L-cell rich ileum raised GLP-1 levels 5- to 6-fold. This increase in the GLP-1 was not associated with the mitigation of hyperglycemia or elevated HbA1c levels. Topics: Anastomosis, Roux-en-Y; Animals; Blood Glucose; Diabetes Mellitus, Type 2; Disease Models, Animal; Glucagon-Like Peptide 1; Glycated Hemoglobin; Ileum; Male; Rats; Rats, Inbred Strains; Weight Gain | 2014 |
Berberine moderates glucose metabolism through the GnRH-GLP-1 and MAPK pathways in the intestine.
Berberine is known to improve glucose and lipid metabolism disorders, but it poorly absorbed into the blood stream from the gut. Therefore, the exact underlying mechanism for berberine is still unknown. In this study, we investigated the effect of berberine on glucose metabolism in diabetic rats and tested the hypothesis that berberine acts directly in the terminal ileums.. Rats were divided into a control group, diabetic group (DM), low dose of berberine group (BerL) and high dose of berberine group (BerH). Ileum samples were analyzed using a Roche NimbleGen mRNA array, qPCR and immunohistochemistry.. We found that 8 weeks of treatment with berberine significantly decreased fasting blood glucose levels. An oral glucose tolerance test (OGTT) showed that blood glucose was significantly reduced in the BerL and BerH groups before and at 30 min, 60 min and 120 min after oral glucose administration. Plasma postprandial glucagon-like peptide-1 (GLP-1) levels were increased in the berberine-treated groups. The ileum from the BerH group had 2112 genes with significantly changed expression (780 increased, 1332 decreased). KEGG pathway analyses indicated that all differentially expressed genes included 9 KEGG pathways. The top two pathways were the MAPK signaling pathway and the GnRH signaling pathway. Q-RT-PCR and immunohistochemistry verified that glucagon-like peptide 1 receptor (Glp1r) and mitogen activated protein kinase 10 (Mapk10) were significantly up-regulated, in contrast, gonadotropin releasing hormone receptor (Gnrhr) and gonadotropin-releasing hormone 1 (Gnrh1) were down-regulated in the BerH group.. Our data suggest that berberine can improve blood glucose levels in diabetic rats. The mechanisms involved may be in the MAPK and GnRh-Glp-1 pathways in the ileum. Topics: Animals; Berberine; Blood Glucose; Body Weight; Carbohydrate Metabolism; Diabetes Mellitus, Experimental; Diabetes Mellitus, Type 2; Gene Expression; Glucagon-Like Peptide 1; Glucagon-Like Peptide-1 Receptor; Glucose; Glucose Tolerance Test; Gonadotropin-Releasing Hormone; Ileum; Insulin; Intestinal Mucosa; Lipid Metabolism; Male; MAP Kinase Signaling System; Phytotherapy; Plant Extracts; Protein Precursors; Random Allocation; Rats; Rats, Sprague-Dawley; Receptors, Glucagon; Reverse Transcriptase Polymerase Chain Reaction | 2014 |
GLP-1 agonism stimulates brown adipose tissue thermogenesis and browning through hypothalamic AMPK.
GLP-1 receptor (GLP-1R) is widely located throughout the brain, but the precise molecular mechanisms mediating the actions of GLP-1 and its long-acting analogs on adipose tissue as well as the brain areas responsible for these interactions remain largely unknown. We found that central injection of a clinically used GLP-1R agonist, liraglutide, in mice stimulates brown adipose tissue (BAT) thermogenesis and adipocyte browning independent of nutrient intake. The mechanism controlling these actions is located in the hypothalamic ventromedial nucleus (VMH), and the activation of AMPK in this area is sufficient to blunt both central liraglutide-induced thermogenesis and adipocyte browning. The decreased body weight caused by the central injection of liraglutide in other hypothalamic sites was sufficiently explained by the suppression of food intake. In a longitudinal study involving obese type 2 diabetic patients treated for 1 year with GLP-1R agonists, both exenatide and liraglutide increased energy expenditure. Although the results do not exclude the possibility that extrahypothalamic areas are also modulating the effects of GLP-1R agonists, the data indicate that long-acting GLP-1R agonists influence body weight by regulating either food intake or energy expenditure through various hypothalamic sites and that these mechanisms might be clinically relevant. Topics: Adipose Tissue, Brown; Adult; Aged; Aged, 80 and over; AMP-Activated Protein Kinase Kinases; Animals; Diabetes Mellitus, Type 2; Drug Therapy, Combination; Eating; Energy Metabolism; Exenatide; Female; Glucagon-Like Peptide 1; Humans; Hypoglycemic Agents; Hypothalamus; Liraglutide; Male; Metformin; Mice; Middle Aged; Obesity; Peptides; Protein Kinases; Rats; Thermogenesis; Venoms; Young Adult | 2014 |
[Bydureon: first once weekly GLP-1 receptor agonist (exenatide LAR)].
Bydureon is a new galenic formulation (long-acting release) of exenatide, the first agonist of Glucagon-Like Peptide-1 (GLP-1) receptors having been commercialized for the management of type 2 diabetes. The microsphere technology permits a prolonged absorption of exenatide from the subcutaneous depot, which allows one injection per week instead of two injections per day with the initial formulation of exenatide (Byetta). The clinical development programme DURATION showed that exenatide 2 mg once weekly more markedly reduces glycated haemoglobin (HbA(1c)), with a similar weight loss but a better digestive tolerance profile (less nausea and vomiting after treatment initiation), compared with the twice daily 10 microg exenatide. When compared to other glucose-lowering agents, once weekly exenatide is more efficacious than sitagliptin, pioglitazone or basal insulin (glargine or detemir), with the advantage of producing weight loss and lowering arterial blood pressure. It does not induce hypoglycaemia and does not necessarily require home blood glucose monitoring, two advantages compared with insulin therapy. Bydureon is currently only reimbursed in Belgium after failure of and in addition to metformin-sulfonylurea combination. Topics: Belgium; Blood Glucose; Delayed-Action Preparations; Diabetes Mellitus, Type 2; Drug Administration Schedule; Exenatide; Glucagon-Like Peptide 1; Glycated Hemoglobin; Humans; Hypoglycemic Agents; Microspheres; Peptides; Reimbursement Mechanisms; Venoms | 2014 |
High-fat diet induces early-onset diabetes in heterozygous Pax6 mutant mice.
Type 2 diabetes is caused by interactions between genetic and environmental factors. Our previous studies reported that paired box 6 mutation heterozygosity (Pax6(m/+)) led to defective proinsulin processing and subsequent abnormal glucose metabolism in mice at 6 months of age. However, high-fat diet exposure could be an important incentive for diabetes development. In this study, we aimed to develop a novel diabetic model imitating human type 2 diabetes by exposing Pax6(m/+) mice to high-fat diet and to explore the underlying mechanism of diabetes in this model.. Over 300 Pax6(m/+) and wild-type male weanling mice were randomly divided into two groups and were fed an high-fat diet or chow diet for 6-10 weeks. Blood glucose and glucose tolerance levels were monitored during this period. Body weights, visceral adipose weights, blood lipid profiles and insulin sensitivity (determined with an insulin tolerance test) were used to evaluate obesity and insulin resistance. Proinsulin processing and insulin secretion levels were used to evaluate pancreatic β cell function.. After 6 weeks of high-fat diet exposure, only the Pax6(m/+) mice showed dramatic postloading hyperglycaemia. These mice exhibited significant high-fat diet-induced visceral obesity and insulin resistance and displayed defective prohormone convertase 1/3 production, an increased proinsulin:total insulin ratio and impaired early-phase insulin secretion, because of the Pax6 mutation. Hyperglycaemia worsened progressively over time with the high-fat diet, and most Pax6(m/+) mice on high-fat diet developed diabetes or impaired glucose tolerance after 10 weeks. Furthermore, high-fat diet withdrawal partly improved blood glucose levels in the diabetic mice.. By combining the Pax6(m/+) genetic background with an high-fat diet environment, we developed a novel diabetic model to mimic human type 2 diabetes. This model is characterized by impaired insulin secretion, caused by the Pax6 mutation, and high-fat diet-induced insulin resistance and therefore provides an ideal tool for research on type 2 diabetes pathogenesis and therapies. Topics: Animals; Diabetes Mellitus, Type 2; Diet, High-Fat; Eye Proteins; Glucagon-Like Peptide 1; Heterozygote; Homeodomain Proteins; Insulin; Insulin Resistance; Insulin Secretion; Islets of Langerhans; Male; Mice, Inbred C57BL; Mice, Mutant Strains; Mutation; Obesity, Abdominal; Paired Box Transcription Factors; PAX6 Transcription Factor; Prediabetic State; Proinsulin; Proprotein Convertase 1; Random Allocation; Repressor Proteins; Weaning; Weight Gain | 2014 |
Oral delivery of glucagon like peptide-1 by a recombinant Lactococcus lactis.
To develop a live oral delivery system of Glucagon like peptide-1 (GLP-1), for the treatment of Type-2 Diabetes.. LL-pUBGLP-1, a recombinant Lactococcus lactis (L. lactis)) transformed with a plasmid vector encoding GLP-1 cDNA was constructed and was used as a delivery system. Secretion of rGLP-1 from LL-pUBGLP-1 was characterized by ELISA. The bioactivity of the rGLP-1 was examined for its insulinotropic activity on HIT-T15 cells. Transport of rGLP-1 across MDCK cell monolayer when delivered by LL-pUBGLP-1 was studied. The therapeutic effect of LL-pUBGLP-1 after oral administration was investigated in ZDF rats.. DNA sequencing and ELISA confirmed the successful construction of the LL-pUBGLP-1 and secretion of the active form of rGLP-1. In vitro insulinotropic studies demonstrated that LL-pUBGLP-1 could significantly (p < 0.05) stimulate HIT-T15 cells to secrete insulin as compared to the controls. When delivered by LL-pUBGLP-1, the GLP-1 transport rate across the MDCK cell monolayer was increased by eight times (p < 0.01) as compared to the free solution form. Oral administration of LL-pUBGLP-1 in ZDF rats resulted in a significant decrease (10-20%, p < 0.05) in blood glucose levels during 2-11 h post dosing and a significant increase in insulin AUC0-11h (2.5 times, p < 0.01) as compared to the free solution.. The present study demonstrates that L. lactis when genetically modified with a recombinant plasmid can be used for the oral delivery of GLP-1. Topics: Animals; Blood Glucose; Diabetes Mellitus, Type 2; Dogs; Drug Delivery Systems; Glucagon-Like Peptide 1; Insulin; Insulin-Secreting Cells; Lactococcus lactis; Madin Darby Canine Kidney Cells; Male; Mesocricetus; Rats; Rats, Zucker | 2014 |
Cost-effectiveness of add-on treatments to metformin in a Swedish setting: liraglutide vs sulphonylurea or sitagplitin.
To evaluate long-run cost-effectiveness in a Swedish setting for liraglutide compared with sulphonylureas (glimepiride) or sitagliptin, all as add-on to metformin for patients with type 2 diabetes insufficiently controlled with metformin in monotherapy.. The IHE Cohort Model of Type 2 Diabetes was used to evaluate clinical and economic outcomes from a societal perspective. Model input data were obtained from two clinical trials, the Swedish National Diabetes Register and the literature. Cost data reflected year 2013 price level. The robustness of results was checked with one-way-sensitivity analysis and probability sensitivity analysis.. The cost per QALY gained for liraglutide (1.2 mg) compared to SU (glimepiride 4 mg), both as add-on to metformin, ranged from SEK 226,000 to SEK 255,000 in analyzed patient cohorts. The cost per QALY for liraglutide (1.2 mg) vs sitagliptin (100 mg) as second-line treatment was lower, ranging from SEK 149,000 to SEK 161,000. Costs of preventive treatment were driving costs, but there was also a cost offset from reduced costs of complications of ∼ 20%. Notable cost differences were found for nephropathy, stroke, and heart failure. The predicted life expectancy with liraglutide increased the cost of net consumption for liraglutide.. The analysis was an ex-ante analysis using model input data from clinical trials which may not reflect effectiveness in real-world clinical practice in broader patient populations. This limitation was explored in the sensitivity analysis. The lack of specific data on loss of production due to diabetes complications implied that these costs may be under-estimated.. Treatment strategies with liraglutide 1.2 mg improved the expected quality-of-life and increased costs when compared to SU and to sitagliptin for second-line add-on treatments. The cost per QALY for liraglutide was in the range considered medium by Swedish authorities. Topics: Cost-Benefit Analysis; Diabetes Mellitus, Type 2; Drug Therapy, Combination; Female; Glucagon-Like Peptide 1; Health Services; Humans; Hypoglycemic Agents; Life Expectancy; Liraglutide; Male; Metformin; Middle Aged; Models, Economic; Pyrazines; Quality-Adjusted Life Years; Sitagliptin Phosphate; Smoking; Sulfonylurea Compounds; Sweden; Triazoles | 2014 |
Potential cardioprotective action of GLP-1: from bench to bedside.
Topics: Atherosclerosis; Cardiotonic Agents; Diabetes Mellitus, Type 2; Glucagon-Like Peptide 1; Humans | 2014 |
Effects of meal size on the release of GLP-1 and PYY after Roux-en-Y gastric bypass surgery in obese subjects with or without type 2 diabetes.
Changes in gastrointestinal peptide release may play an important role in improving glucose control and reducing body weight following Roux-en-Y gastric bypass (RYGB), but the impact of low caloric intake on gut peptide release post-surgery has not been well characterized. The purpose of this study was to assess the relationships between low caloric intake and gut peptide release and how they were altered by RYGB. Obese females including ten normoglycemic (ON) and ten with type 2 diabetes mellitus (T2DM) (OD) were studied before, 1 week, and 3 months after RYGB. Nine lean, normoglycemic women were studied for comparison. Subjects were given three separate mixed meal challenges (MMCs; 75, 150, and 300 kcal). Plasma glucagon-like peptide 1 (GLP-1) and peptide YY (PYY) were analyzed. Prior to surgery, only minimal increases in GLP-1 and PYY were observed in response to the MMCs. After surgery, the peak GLP-1 concentration was progressively elevated in response to increasing meal sizes. The meal sizes had a statistically significant impact on elevation of GLP-1 incremental areas under the curve (ΔAUC) in both ON and OD at 1 week and 3 months post-surgery visits (p < 0.05 for all comparisons). The PYY ∆AUC was also significantly increased in a meal size-dependent manner in both ON and OD at both post-surgery visits (p < 0.05 for all comparisons). Meal sizes as small as 75-300 kcal, which cause minimal stimulation in GLP-1 or PYY release in the subjects before RYGB, are sufficient to provide statistically significant, meal size-dependent increases in the peptides post-RYGB both acutely and after meaningful weight loss occurred. Topics: Adult; Anastomosis, Roux-en-Y; Diabetes Mellitus, Type 2; Female; Food; Glucagon-Like Peptide 1; Humans; Middle Aged; Obesity, Morbid; Peptide YY; Postoperative Period | 2014 |
Which incretin-based therapy for type 2 diabetes?
Topics: Diabetes Mellitus, Type 2; Female; Glucagon-Like Peptide 1; Glucagon-Like Peptides; Humans; Hypoglycemic Agents; Immunoglobulin Fc Fragments; Liraglutide; Male; Recombinant Fusion Proteins | 2014 |
Increased plasma DPP4 activity is predictive of prediabetes and type 2 diabetes onset in Chinese over a four-year period: result from the China National Diabetes and Metabolic Disorders Study.
The significance of associations between prediabetes, type 2 diabetes, and dipeptidyl peptidase-4 (DPP4) activity in a Chinese population is not clear.. The objective of the study was to determine whether DPP4 activity and active glucagon-like peptide-1 (GLP-1) were predictive of the onset of prediabetes and type 2 diabetes.. This was a 4-year follow-up study conducted in Sichuan, China. A total of 474 Chinese women and men aged 18-70 years were studied.. All subjects were divided into 3 groups (normal glucose tolerance, prediabetes, and type 2 diabetes) on the basis of their glucose metabolism status after 4 years. The DPP4 activity, active GLP-1, and glucagon were measured at baseline and 4 years later.. The baseline DPP4 activity was significantly higher in subjects who had progressed to prediabetes or type 2 diabetes compared with subjects who remained normoglycemic (P < .01). In a multiple linear regression analysis, baseline DPP4 activity and active GLP-1 were independent predictors of an increase in insulin resistance over a 4-year period (P < .05). Cox proportional hazards models revealed that DPP4 activity independently predicted the risk of developing prediabetes [relative risk 2.77 (95% confidence interval 1.38-5.55), P < .01] and type 2 diabetes [5.10 (95% confidence interval 1.48-17.61), P < .05] after adjustment for confounding risk factors.. DPP4 activity is an important predictor of the onset of insulin resistance, prediabetes, and type 2 diabetes in apparently healthy Chinese individuals. This finding may have important implications for understanding the etiology of diabetes. Topics: Adolescent; Adult; Aged; Blood Glucose; China; Diabetes Mellitus, Type 2; Dipeptidyl Peptidase 4; Female; Follow-Up Studies; Glucagon-Like Peptide 1; Glucose Tolerance Test; Health Surveys; Humans; Insulin Resistance; Longitudinal Studies; Male; Middle Aged; Prediabetic State; Risk; Young Adult | 2014 |
Novel coumarin modified GLP-1 derivatives with enhanced plasma stability and prolonged in vivo glucose-lowering ability.
The short biological half-life limits the therapeutic use of glucagon-like peptide-1 (GLP-1) and chemical modification to improve the interaction of peptides with serum albumin represents an effective strategy to develop long-acting peptide analogues. Coumarin, a natural product, is known to bind tightly to plasma proteins and possesses many biological activities. Therefore, we designed and synthesized a series of coumarin-modified GLP-1 derivatives, hypothesizing that conjugation with coumarin would retain the therapeutic effects and prolong the biological half-life of the conjugates.. Four cysteine-modified GLP-1 analogues (1-4) were prepared using Gly8 -GLP-1(7-36)-NH2 peptide as a starting point. These analogues were conjugated with two coumarin maleimides to yield eight compounds (conjugates 6-13) for testing. Activation of human GLP-1 receptors, stability to enzymic inactivation in plasma and binding to human albumin were assessed in vitro. In vivo, effects on oral glucose tolerance tests (OGTT) in rats and on blood glucose levels in db/db mice were studied.. Most conjugates showed well preserved receptor activation efficacy, enhanced albumin-binding properties and improved in vitro plasma stability and conjugate 7 was selected to undergo further assessment. In rats, conjugate 7 had a longer circulating t1/2 than exendin-4 or liraglutide. A prolonged antidiabetic effect of conjugate 7 was observed after OGTT in rats and a prolonged hypoglycaemic effect in db/db mice.. Cysteine-specific coumarin conjugation with GLP-1 offers a useful approach to the development of long-acting incretin-based antidiabetic agents. Conjugate 7 is a promising long-lasting GLP-1 derivative deserving further investigation. Topics: Animals; Coumarins; Diabetes Mellitus, Type 2; Disease Models, Animal; Exenatide; Glucagon-Like Peptide 1; Glucagon-Like Peptide-1 Receptor; Glucose; Glucose Tolerance Test; HEK293 Cells; Humans; Hypoglycemic Agents; Insulin; Insulin Secretion; Liraglutide; Male; Mice, Inbred C57BL; Peptides; Rats, Sprague-Dawley; Receptors, Glucagon; Serum Albumin; Venoms | 2014 |
GLP-1 provoked severe hypoglycemia in an individual with type 2 diabetes and a benign insulinoma.
Topics: Diabetes Mellitus, Type 2; Female; Glucagon-Like Peptide 1; Glucagon-Like Peptide-1 Receptor; Humans; Hypoglycemia; Insulin; Insulinoma; Liraglutide; Middle Aged; Pancreatic Neoplasms; Receptors, Glucagon; Severity of Illness Index | 2014 |
Dietary sweet potato (Ipomoea batatas L.) leaf extract attenuates hyperglycaemia by enhancing the secretion of glucagon-like peptide-1 (GLP-1).
'Suioh', a sweet potato (Ipomoea batatas L.) cultivar developed in Japan, has edible leaves and stems. The sweet potato leaves contain polyphenols such as caffeoylquinic acid (CQA) derivatives. It has multiple biological functions and may help to regulate the blood glucose concentration. In this study, we first examined whether sweet potato leaf extract powder (SP) attenuated hyperglycaemia in type 2 diabetic mice. Administration of dietary SP for 5 weeks significantly lowered glycaemia in type 2 diabetic mice. Second, we conducted in vitro experiments, and found that SP and CQA derivatives significantly enhanced glucagon-like peptide-1 (GLP-1) secretion. Third, pre-administration of SP significantly stimulated GLP-1 secretion and was accompanied by enhanced insulin secretion in rats, which resulted in a reduced glycaemic response after glucose injection. These results indicate that oral SP attenuates postprandial hyperglycaemia, possibly through enhancement of GLP-1 secretion. Topics: Animals; Diabetes Mellitus, Type 2; Glucagon-Like Peptide 1; Glucose; Humans; Hyperglycemia; Insulin; Ipomoea batatas; Male; Mice; Plant Extracts; Plant Leaves; Rats; Rats, Sprague-Dawley; Up-Regulation | 2014 |
Diabetes: safety and efficacy of albiglutide-results from two trials.
Type 2 diabetes mellitus is associated with a poor quality of life and considerable health-care costs and can be difficult to control. The recent results from the HARMONY 3 and HARMONY 6 trials suggest that albiglutide is a safe and effective treatment option for patients with type 2 diabetes mellitus. Topics: Diabetes Mellitus, Type 2; Female; Glucagon-Like Peptide 1; Humans; Hypoglycemic Agents; Male; Pyrazines; Sulfonylurea Compounds; Triazoles | 2014 |
Switching from insulin to liraglutide improved glycemic control and the quality of life scores in a case of type 2 diabetes and active Crohn's disease.
A 44-year-old man with type 2 diabetes of five years' duration was admitted for the management of poor glycemic control despite the administration of insulin therapy. On admission, he received vigorous treatment for a 28-year history of Crohn's disease and a 14-year history of a psychiatric disorder. His glycosylated hemoglobin A1c (HbA1c) level was 11.3%, his fasting blood glucose level was 567 mg/dL and his C-peptide level was 1.0 ng/mL. His quality of life (QOL) was severely impaired as a result of frequent episodes of hyperglycemia and hypoglycemia. Treatment with liraglutide was commenced in place of insulin, which improved the patient's glycemic control to an HbA1c level of 5.5% and markedly increased his QOL score with no hypoglycemia. Topics: Adult; Blood Glucose; Crohn Disease; Diabetes Mellitus, Type 2; Glucagon-Like Peptide 1; Glycated Hemoglobin; Humans; Hypoglycemic Agents; Insulin; Liraglutide; Male; Quality of Life | 2014 |
Determinants of glycaemic control in a practice setting: the role of weight loss and treatment adherence (The DELTA Study).
Examine the association between weight loss and adherence with glycaemic goal attainment in patients with inadequately controlled T2DM.. Patients ≥ 18 years with T2DM from a US integrated health system starting a new class of diabetes medication between 11/1/10 and 4/30/11 (index date) with baseline HbA1c ≥ 7.0% were included in this cohort study. Target HbA1c and weight change were defined at 6-months as HbA1c < 7.0% and ≥ 3% loss in body weight. Patient-reported medication adherence was assessed per the Medication Adherence Reporting Scale. Structural equation modelling was used to describe simultaneous associations between adherence, weight loss and HbA1c goal attainment.. Inclusion criteria were met by 477 patients; mean (SD) age 59.1 (11.6) years; 50.9% were female; 30.4% were treatment naïve; baseline HbA1c 8.6% (1.6); weight 102.0 kg (23.0). Most patients (67.9%) reported being adherent to the index diabetes medication. At 6 months mean weight change was -1.3 (5.1) kg (p = 0.39); 28.1% had weight loss of ≥ 3%. Mean HbA1c change was -1.2% (1.8) (p< 0.001); 42.8% attained HbA1c goal. Adherent patients (OR 1.70; p = 0.02) and diabetes therapies that lead to weight loss (metformin, GLP-1) were associated with weight loss ≥ 3% (OR 2.96; p< 0.001). Weight loss (OR 3.60; p < 0.001) and adherence (OR 1.59; p < 0.001) were associated with HbA1c goal attainment.. Weight loss ≥ 3% and medication adherence were associated with HbA1c goal attainment in T2DM; weight loss was a stronger predictor of goal attainment than medication adherence in this study population. It is important to consider weight-effect properties, in addition to patient-centric adherence counselling, when prescribing diabetes therapy. Topics: Adult; Aged; Body Weight; Cohort Studies; Diabetes Mellitus, Type 2; Female; Glucagon-Like Peptide 1; Glycemic Index; Humans; Male; Medication Adherence; Middle Aged; Sulfonylurea Compounds; Weight Loss | 2014 |
Ileal interposition reduces blood glucose levels and decreases insulin resistance in a type 2 diabetes mellitus animal model by up-regulating glucagon-like peptide-1 and its receptor.
This study is to explore the possible mechanism of ileal interposition (IT) treatment of glycemic control of the type 2 diabetes mellitus (T2DM) by establishing an IT animal model. Twelve T2DM rats (GK rats) of 8-week old were divided into GK IT surgery group (GK-IT) and GK sham group (GK-Sham). Six Wistar rats were used as the non-T2DM sham group (WS-Sham). Enzyme-linked immunosorbent assay was used to detect plasma insulin concentration and fasting pancreas glucagon-like peptide-1 (GLP-1) concentration changes. Homeostasis model assessment of insulin resistance was used to quantitatively measure insulin resistance. Glucagon-like peptide-1 receptor (GLP-1R) expression was detected by Western blotting. IT significantly decreased fasting blood glucose level and the oral glucose tolerance, and reduced insulin resistance of GK rats by increasing GLP-1 concentration and GLP-1R levels. The postoperative pancreatic β-cell apoptosis rate of GK-Sham group was significantly higher than those in the GK-IT group and the WS-Sham group. IT significantly reduces blood glucose and decreases insulin resistance by up-regulating GLP-1 concentrations and GLP-1R levels, which may contribute to insulin secretion of pancreatic β-cells and decreases apoptosis of pancreatic β-cell. Topics: Animals; Blood Glucose; Blotting, Western; Diabetes Mellitus, Experimental; Diabetes Mellitus, Type 2; Enzyme-Linked Immunosorbent Assay; Glucagon-Like Peptide 1; Glucagon-Like Peptide-1 Receptor; Ileum; Insulin Resistance; Insulin-Secreting Cells; Jejunoileal Bypass; Male; Rats; Rats, Wistar; Receptors, Glucagon; Up-Regulation | 2014 |
Liraglutide as a potentially useful agent for regulating appetite in diabetic patients with hypothalamic hyperphagia and obesity.
Hypothalamic hyperphagia and obesity are characterized by a lack of satiety and an abnormally high appetite that is difficult to control. We herein report the cases of two patients with hypothalamic hyperphagia and obesity with MRI-detectable hypothalamic lesions. These patients suffered from diabetes mellitus associated with an abnormal eating behavior and weight gain. Liraglutide was successfully used to treat their diabetes mellitus and suppress their abnormal appetites. Glucagon-like peptide-1 analogues, including liraglutide, are promising treatment options in patients with hypothalamic hyperphagia and obesity, as these agents enhance the hypothalamic input of the satiety signal, which is lacking in such patients. Topics: Adult; Aged; Appetite; Diabetes Mellitus, Type 2; Glucagon-Like Peptide 1; Humans; Hyperphagia; Hypoglycemic Agents; Hypothalamic Diseases; Hypothalamo-Hypophyseal System; Liraglutide; Male; Obesity; Treatment Outcome | 2014 |
Decreased gastric motility in type II diabetic patients.
To differentiate gastric motility and sensation between type II diabetic patients and controls and explore different expressions of gastric motility peptides.. Eleven type II diabetic patients and health volunteers of similar age and body mass index were invited. All underwent transabdominal ultrasound for gastric motility and visual analogue scales. Blood samples were taken for glucose and plasma peptides (ghrelin, motilin, and glucagon-like peptides-1) by ELISA method.. Gastric emptying was significantly slower in diabetic patients than controls (T50: 46.3 (28.0-52.3) min versus 20.8 (9.6-22.8) min, P ≤ 0.05) and less antral contractions in type II diabetic patients were observed (P = 0.02). Fundus dimensions did not differ. There were a trend for less changes in gastrointestinal sensations in type II diabetic patients especially abdomen fullness, hunger, and abdominal discomfort. Although the serum peptides between the two groups were similar a trend for less serum GLP-1 in type II diabetic patients was observed (P = 0.098).. Type II diabetic patients have delayed gastric emptying and less antral contractions than controls. The observation that there were lower serum GLP-1 in type II diabetic patients could offer a clue to suggest that delayed gastric emptying in diabetic patients is not mainly influenced by GLP-1. Topics: Body Mass Index; Case-Control Studies; Diabetes Mellitus, Type 2; Female; Gastric Emptying; Gastrointestinal Motility; Glucagon-Like Peptide 1; Glucose; Humans; Male; Middle Aged; Peptides; Stomach | 2014 |
Biological activity studies of the novel glucagon-like peptide-1 derivative HJ07.
To identify the glucose lowering ability and chronic treatment effects of a novel coumarin-glucagon-like peptide-1 (GLP-1) conjugate HJ07.. A receptor activation experiment was performed in HEK 293 cells and the glucose lowering ability was evaluated with hypoglycemic duration and glucose stabilizing tests. Chronic treatment was performed by daily injection of exendin-4, saline, and HJ07. Body weight and HbA1c were measured every week, and an intraperitoneal glucose tolerance test was performed before treatment and after treatment.. HJ07 showed well-preserved receptor activation efficacy. The hypoglycemic duration test showed that HJ07 possessed a long-acting, glucose-lowering effect and the glucose stabilizing test showed that the antihyperglycemic activity of HJ07 was still evident at a predetermined time (12 h) prior to the glucose challenge (0 h). The long time glucose-lowering effect of HJ07 was better than native GLP-1 and exendin-4. Furthermore, once daily injection of HJ07 to db/db mice achieved long-term beneficial effects on HbA1c lowering and glucose tolerance.. The biological activity results of HJ07 suggest that HJ07 is a potential long-acting agent for the treatment of type 2 diabetes. Topics: Animals; Blood Glucose; Coumarins; Diabetes Mellitus; Diabetes Mellitus, Type 2; Exenatide; Glucagon-Like Peptide 1; Glucagon-Like Peptide-1 Receptor; Glucose Tolerance Test; Glycated Hemoglobin; HEK293 Cells; Humans; Hypoglycemic Agents; Male; Mice, Inbred C57BL; Mice, Knockout; Peptides; Receptors, Glucagon; Venoms | 2014 |
Leptin restores the insulinotropic effect of exenatide in a mouse model of type 2 diabetes with increased adiposity induced by streptozotocin and high-fat diet.
Leptin may reduce pancreatic lipid deposition, which increases with progression of obesity and can impair β-cell function. The insulinotropic effect of glucagon-like peptide-1 (GLP-1) and the efficacy of GLP-1 receptor agonist are reduced associated with impaired β-cell function. In this study, we examined whether leptin could restore the efficacy of exenatide, a GLP-1 receptor agonist, in type 2 diabetes with increased adiposity. We chronically administered leptin (500 μg·kg⁻¹·day⁻¹) and/or exenatide (20 μg·kg⁻¹·day⁻¹) for 2 wk in a mouse model of type 2 diabetes with increased adiposity induced by streptozotocin and high-fat diet (STZ/HFD mice). The STZ/HFD mice exhibited hyperglycemia, overweight, increased pancreatic triglyceride level, and reduced glucose-stimulated insulin secretion (GSIS); moreover, the insulinotropic effect of exenatide was reduced. However, leptin significantly reduced pancreatic triglyceride level, and adding leptin to exenatide (LEP/EX) remarkably enhanced GSIS. These results suggested that the leptin treatment restored the insulinotropic effect of exenatide in the mice. In addition, LEP/EX reduced food intake, body weight, and triglyceride levels in the skeletal muscle and liver, and corrected hyperglycemia to a greater extent than either monotherapy. The pair-feeding experiment indicated that the marked reduction of pancreatic triglyceride level and enhancement of GSIS by LEP/EX occurred via mechanisms other than calorie restriction. These results suggest that leptin treatment may restore the insulinotropic effect of exenatide associated with the reduction of pancreatic lipid deposition in type 2 diabetes with increased adiposity. Combination therapy with leptin and exenatide could be an effective treatment for patients with type 2 diabetes with increased adiposity. Topics: Adiposity; Animals; Anti-Obesity Agents; Diabetes Mellitus, Type 2; Diet, High-Fat; Disease Models, Animal; Drug Implants; Drug Synergism; Drug Therapy, Combination; Exenatide; Glucagon-Like Peptide 1; Hyperglycemia; Hypoglycemic Agents; Insulin; Insulin Secretion; Leptin; Male; Mice, Inbred C57BL; Overweight; Pancreas; Peptides; Recombinant Proteins; Streptozocin; Triglycerides; Venoms | 2014 |
Does the hepatic branch of vagus mediate the secretion of glucagon-like peptide-1 during the Roux-en-Y gastric bypass surgery?
The purpose of this study is to investigate the impact of the hepatic branch of the vagus and Roux-en-Y gastric bypass (RYGB) on the level of fasting and postprandial serum glucagon-like peptide-1 (GLP-1) in type 2 diabetic mellitus rats.. Randomized block design, factorial experiment. Forty-five type 2 diabetic rats were divided into four groups: sham operation (S, n = 10) and sham operation with the hepatic branch of the vagotomy (SV, n = 11), Roux-en-Y gastric bypass (RYGB, n = 12) and RYGB without preservation of the vagus (RYGBV, n = 12). Levels of fasting and postprandial serum GLP-1 30 min after 50 % glucose solution (2 g/kg) by gavage were determined before surgery and postoperatively at 1, 4, and 8 weeks. Interactions between RYGB and the common hepatic branch were also assessed.. Roux-en-Y gastric bypass surgery significantly increased the concentration of postprandial serum GLP-1 and maintained it at a higher level (P < 0.05). Preservation of vagus hepatic branch only increased the concentration of postprandial serum GLP-1 at the initial stage (P < 0.05), which gradually weakened over time (P > 0.05). Both RYGB and vagotomy of the hepatic branch had no influence on fasting serum GLP-1 (P > 0.05).. During RYGB surgery for the long-term treatment of T2DM, preservation of the hepatic branch of the vagus might have no impact on serum GLP-1 level. Topics: Analysis of Variance; Anastomosis, Roux-en-Y; Animals; Blood Glucose; Body Weight; Diabetes Mellitus, Experimental; Diabetes Mellitus, Type 2; Disease Models, Animal; Gastric Bypass; Glucagon-Like Peptide 1; Insulin Resistance; Liver; Male; Random Allocation; Rats; Rats, Sprague-Dawley; Reference Values; Streptozocin; Survival Rate; Treatment Outcome; Vagotomy; Vagus Nerve | 2014 |
The shot clock.
Topics: Diabetes Mellitus, Type 2; Glucagon-Like Peptide 1; Humans; Hypoglycemic Agents; Injections, Intramuscular | 2014 |
Fixed-ratio combination of basal insulin and GLP-1 receptor agonist: is two better than one?
Topics: Diabetes Mellitus, Type 2; Female; Glucagon-Like Peptide 1; Humans; Hypoglycemic Agents; Insulin, Long-Acting; Male | 2014 |
The GIP receptor displays higher basal activity than the GLP-1 receptor but does not recruit GRK2 or arrestin3 effectively.
Glucagon-like peptide-1 (GLP-1) and glucose-dependent insulinotropic polypeptide (GIP) are important regulators of insulin secretion, and their functional loss is an early characteristic of type 2 diabetes mellitus (T2DM). Pharmacological levels of GLP-1, but not GIP, can overcome this loss. GLP-1 and GIP exert their insulinotropic effects through their respective receptors expressed on pancreatic β-cells. Both the GLP-1 receptor (GLP-1R) and the GIP receptor (GIPR) are members of the secretin family of G protein-coupled receptors (GPCRs) and couple positively to adenylate cyclase. We compared the signalling properties of these two receptors to gain further insight into why GLP-1, but not GIP, remains insulinotropic in T2DM patients.. GLP-1R and GIPR were transiently expressed in HEK-293 cells, and basal and ligand-induced cAMP production were investigated using a cAMP-responsive luciferase reporter gene assay. Arrestin3 (Arr3) recruitment to the two receptors was investigated using enzyme fragment complementation, confocal microscopy and fluorescence resonance energy transfer (FRET).. GIPR displayed significantly higher (P<0.05) ligand-independent activity than GLP-1R. Arr3 displayed a robust translocation to agonist-stimulated GLP-1R but not to GIPR. These observations were confirmed in FRET experiments, in which GLP-1 stimulated the recruitment of both GPCR kinase 2 (GRK2) and Arr3 to GLP-1R. These interactions were not reversed upon agonist washout. In contrast, GIP did not stimulate recruitment of either GRK2 or Arr3 to its receptor. Interestingly, arrestin remained at the plasma membrane even after prolonged (30 min) stimulation with GLP-1. Although the GLP-1R/arrestin interaction could not be reversed by agonist washout, GLP-1R and arrestin did not co-internalise, suggesting that GLP-1R is a class A receptor with regard to arrestin binding.. GIPR displays higher basal activity than GLP-1R but does not effectively recruit GRK2 or Arr3. Topics: Animals; Arrestins; CHO Cells; Cricetinae; Cricetulus; Diabetes Mellitus, Type 2; G-Protein-Coupled Receptor Kinase 2; Gastric Inhibitory Polypeptide; Glucagon-Like Peptide 1; Glucagon-Like Peptide-1 Receptor; HEK293 Cells; Humans; Protein Binding; Receptors, Gastrointestinal Hormone | 2014 |
A potent α/β-peptide analogue of GLP-1 with prolonged action in vivo.
Glucagon-like peptide-1 (GLP-1) is a natural agonist for GLP-1R, a G protein-coupled receptor (GPCR) on the surface of pancreatic β cells. GLP-1R agoinsts are attractive for treatment of type 2 diabetes, but GLP-1 itself is rapidly degraded by peptidases in vivo. We describe a design strategy for retaining GLP-1-like activity while engendering prolonged activity in vivo, based on strategic replacement of native α residues with conformationally constrained β-amino acid residues. This backbone-modification approach may be useful for developing stabilized analogues of other peptide hormones. Topics: Amino Acid Sequence; Animals; Cells, Cultured; Diabetes Mellitus, Type 2; Glucagon-Like Peptide 1; Glucagon-Like Peptide-1 Receptor; Humans; Mice; Molecular Sequence Data; Protein Stability; Receptors, Glucagon | 2014 |
Long-acting GLP-1 analogue in V-shaped conformation by terminal polylysine modifications.
Glucagon-like peptide-1 (GLP-1) possesses multiple physiological functions, which make it a potential drug candidate for the treatment of type 2 diabetes. However, its clinical application was limited severely by its short half-life in vivo. Therefore, stabilization of GLP-1 is critical for the use of this peptide in drug development. In this study, a novel GLP-1 derivative, VGLP1K6, processed a significantly prolonged half-life in vivo. Structural analysis using molecular dynamics simulations demonstrated that VGLP1K6 has a rigid V-shaped conformation resulting from the intrapeptide disulfide bond. The C-terminal polylysine residues of VGLP1K6 caused the vulnerable N-terminus of GLP-1 (HA-fragment) to reside within the pocket-like cavity of the peptide due to the intrahydrogen bonds. The structural analysis suggested that this structural alteration contributed to the remarkable prolonged half-life of VGLP1K6, which was approximately 70 h. In addition, VGLP1K6 induced better long-acting glucose tolerance and greater HbA1c reductions than GLP-1 in rodents. Our findings suggest that the GLP-1 derivative VGLP1K6 might be a possible potent antidiabetic drug for the treatment of type 2 diabetes mellitus. Topics: Animals; Blood Glucose; Diabetes Mellitus, Type 2; Glucagon-Like Peptide 1; Glucagon-Like Peptide-1 Receptor; Glucose Tolerance Test; Glycated Hemoglobin; Half-Life; Hypoglycemic Agents; Insulin; Kinetics; Male; Polylysine; Rats; Rats, Sprague-Dawley; Rats, Zucker; Receptors, Glucagon | 2014 |
Cost-effectiveness analysis of liraglutide versus sitagliptin or exenatide in patients with inadequately controlled Type 2 diabetes on oral antidiabetic drugs in Greece.
To evaluate the long-term cost-effectiveness of liraglutide versus sitagliptin or exenatide, added to oral antidiabetic drug mono- or combination therapy respectively, in patients with Type 2 diabetes in Greece.. The CORE Diabetes Model, a validated computer simulation model, was adapted to the Greek healthcare setting. Patient and intervention effects data were gathered from a clinical trial comparing liraglutide 1.2 mg once daily vs. sitagliptin 100 mg once daily, both combined with metformin, and a clinical trial comparing liraglutide 1.8 mg once daily vs. exenatide 10 μg twice daily, both as add-on to metformin, glimepiride or both. Direct costs were reported in 2013 Euros and calculated based on published and local sources. All future outcomes were discounted at 3.5% per annum, and the analysis was conducted from the perspective of a third-party payer in Greece.. Over a patient's lifetime, treatment with liraglutide 1.2 mg vs. sitagliptin drove a mean increase in discounted life expectancy of 0.13 (SD 0.23) years and in discounted quality-adjusted life expectancy of 0.19 (0.16) quality-adjusted life years (QALYs), whereas therapy with liraglutide 1.8 mg vs. exenatide yielded increases of 0.14 (0.23) years and 0.19 (0.16) QALYs respectively. As regards lifetime direct costs, liraglutide 1.2 mg resulted in greater costs of €2797 (€1468) versus sitagliptin, and so did liraglutide 1.8 mg compared with exenatide (€1302 [€1492]). Liraglutide 1.2 and 1.8 mg doses were associated with incremental cost effectiveness ratios of €15101 and €6818 per QALY gained, respectively.. Liraglutide is likely to be a cost-effective option for the treatment of Type 2 diabetes in a Greek setting. Topics: Adult; Computer Simulation; Cost-Benefit Analysis; Diabetes Mellitus, Type 2; Exenatide; Female; Glucagon-Like Peptide 1; Greece; Humans; Hypoglycemic Agents; Liraglutide; Male; Middle Aged; Peptides; Pyrazines; Sitagliptin Phosphate; Triazoles; Venoms | 2014 |
The effects of liraglutide on male fertility: a case report.
Liraglutide is an agonist of the glucagon-like peptide I receptor, and is commonly recommended as a treatment for obesity and type 2 diabetes mellitus. Adverse effects related to liraglutide include acute pancreatitis and polyarthritis. No studies, however, have reported an adverse effect of liraglutide on male reproduction. This case report shows a deleterious effect of liraglutide on male reproductive function. Topics: Adult; Diabetes Mellitus, Type 2; Female; Fertility; Glucagon-Like Peptide 1; Humans; Hypoglycemic Agents; Infertility, Male; Liraglutide; Male; Obesity; Pregnancy; Pregnancy Outcome; Sperm Count; Sperm Injections, Intracytoplasmic; Sperm Motility; Spermatozoa | 2014 |
GLP-1 as a mediator in the remission of type 2 diabetes after gastric bypass and sleeve gastrectomy surgery.
Topics: Blood Glucose; Diabetes Mellitus, Type 2; Female; Glucagon-Like Peptide 1; Humans; Male; Obesity, Morbid | 2014 |
[Hormonal deficiencies in the elderly: is there a role for replacement therapy?].
Biological aging is characterized by a progressive loss of the secretion of various hormones, a phenomenon that leads some physicians to propose an anti-aging hormonal therapy. It is mandatory to differentiate: 1) the physiological functional loss, which is a natural phenomenon without clear deleterious consequences on health and should not be compensated by the administration of hormones only to restore plasma levels similar to those measured in young people and 2) a pathological defect that deserves a replacement therapy to correct the endocrine deficiency and improve the health status of older individuals. This article considers the deficiencies in insulin, thyroid hormones, growth hormone, dehydroepiandrosterone (DHEA) and testosterone. For each hormone, a benefit/risk ratio of a so-called replacement therapy will be analyzed. Topics: Adjuvants, Immunologic; Aged; Aging; Androgens; Dehydroepiandrosterone; Diabetes Mellitus, Type 2; Female; Glucagon-Like Peptide 1; Growth Hormone; Health Status; Hormone Replacement Therapy; Humans; Hypoglycemic Agents; Insulin; Male; Metformin; Testosterone; Thyroid Hormones | 2014 |
Discovery of a class of endogenous mammalian lipids with anti-diabetic and anti-inflammatory effects.
Increased adipose tissue lipogenesis is associated with enhanced insulin sensitivity. Mice overexpressing the Glut4 glucose transporter in adipocytes have elevated lipogenesis and increased glucose tolerance despite being obese with elevated circulating fatty acids. Lipidomic analysis of adipose tissue revealed the existence of branched fatty acid esters of hydroxy fatty acids (FAHFAs) that were elevated 16- to 18-fold in these mice. FAHFA isomers differ by the branched ester position on the hydroxy fatty acid (e.g., palmitic-acid-9-hydroxy-stearic-acid, 9-PAHSA). PAHSAs are synthesized in vivo and regulated by fasting and high-fat feeding. PAHSA levels correlate highly with insulin sensitivity and are reduced in adipose tissue and serum of insulin-resistant humans. PAHSA administration in mice lowers ambient glycemia and improves glucose tolerance while stimulating GLP-1 and insulin secretion. PAHSAs also reduce adipose tissue inflammation. In adipocytes, PAHSAs signal through GPR120 to enhance insulin-stimulated glucose uptake. Thus, FAHFAs are endogenous lipids with the potential to treat type 2 diabetes. Topics: Adipose Tissue; Adult; Animals; Diabetes Mellitus, Type 2; Diet; Esters; Fatty Acids; Female; Glucagon-Like Peptide 1; Glucose Transporter Type 4; Humans; Inflammation; Insulin; Insulin Resistance; Lipogenesis; Male; Mass Spectrometry; Mice, Inbred C57BL; Middle Aged; Receptors, G-Protein-Coupled | 2014 |
[Incretin mimetic drugs: therapeutic positioning].
Type 2 diabetes is a chronic and complex disease, due to the differences among affected individuals, which affect choice of treatment. The number of drug families has increased in the last few years, and these families have widely differing mechanisms of action, which contributes greatly to the individualization of treatment according to the patient's characteristics and comorbidities. The present article discusses incretin mimetic drugs. Their development has been based on knowledge of the effects of natural incretin hormones: GLP-1 (glucagon-like peptide 1), GIP (glucose-dependent insulinotropic peptide) and dipeptidyl peptidase enzyme 4 (DPP4), which rapidly degrade them in the systemic circulation. This group is composed of 2 different types of molecules: GLP-1 analogs and DPP4 enzyme inhibitors. The benefits of these molecules include a reduction in plasma glucose without the risk of hypoglycemias or weight gain. There are a series of questions that require new studies to establish a possible association between the use of these drugs and notification of cases of pancreatitis, as well as their relationship with pancreatic and thyroid cancer. Also awaited is the publication of several studies that will provide information on the relationship between these drugs and cardiovascular risk in people with diabetes. All these questions will probably be progressively elucidated with greater experience in the use of these drugs. Topics: Blood Glucose; Diabetes Mellitus, Type 2; Dipeptidyl-Peptidase IV Inhibitors; Drug Design; Glucagon-Like Peptide 1; Humans; Hypoglycemic Agents; Incretins | 2014 |
Liraglutide-induced acute pancreatitis.
An obese lady of 51 year with Type 2 Diabetes Mellitus for 13 years was prescribed Liraglutide, a glucagon like peptide (GLP-1) analogue (Victoza) for glycaemic control and reduction of weight. She was on gliclazide and Insulin prior to initiation of Liraglutide. Eight weeks after initiation of GLP -1 analogue, she developed severe abdominal pain, nausea and vomiting. She was admitted to a private hospital and evaluated. Biochemical tests and CT scan revealed presence of pancreatitis and she was treated for acute pancreatitis. Liraglutide was withdrawn and symptoms subsided. Subsequent follow-up showed that pancreatic enzyme levels were normal. Topics: Acute Disease; Diabetes Mellitus, Type 2; Female; Glucagon-Like Peptide 1; Humans; Hypoglycemic Agents; Liraglutide; Middle Aged; Pancreatitis | 2014 |
Identifying good responders to glucose lowering therapy in type 2 diabetes: implications for stratified medicine.
Defining responders to glucose lowering therapy can be important for both clinical care and for the development of a stratified approach to diabetes management. Response is commonly defined by either HbA1c change after treatment or whether a target HbA1c is achieved. We aimed to determine the extent to which the individuals identified as responders and non-responders to glucose lowering therapy, and their characteristics, depend on the response definition chosen.. We prospectively studied 230 participants commencing GLP-1 agonist therapy. We assessed participant characteristics at baseline and repeated HbA1c after 3 months treatment. We defined responders (best quartile of response) based on HbA1c change or HbA1c achieved. We assessed the extent to which these methods identified the same individuals and how this affected the baseline characteristics associated with treatment response.. Different definitions of response identified different participants. Only 39% of responders by one definition were also good responders by the other. Characteristics associated with good response depend on the response definition chosen: good response by HbA1c achieved was associated with low baseline HbA1c (p<0.001), high C-peptide (p<0.001) and shorter diabetes duration (p = 0.01) whereas response defined by HbA1c change was associated with high HbA1c (p<0.001) only. We describe a simple novel method of defining treatment response based on a combination of HbA1c change and HbA1c achieved that defines response groups with similar baseline glycaemia.. The outcome of studies aiming to identify predictors of treatment response to glucose lowering therapy may depend on how response is defined. Alternative definitions of response should be considered which minimise influence of baseline glycaemia. Topics: Blood Glucose; C-Peptide; Creatinine; Diabetes Mellitus, Type 2; Female; Glucagon-Like Peptide 1; Glycated Hemoglobin; Humans; Hyperglycemia; Male; Middle Aged; Prospective Studies; Time Factors; Treatment Outcome; Triglycerides | 2014 |
Multiple drug combination of anti-diabetic agents as a predictor for poor clinical response to liraglutide.
Aim of the study was to retrospectively analyze the clinical parameters that contribute to the therapeutic outcome of GLP-1 analogues.. We enrolled 106 patients with type 2 diabetes mellitus (T2DM), treated with liraglutide (N.=69) or exenatide (N.=37) for longer than three months. The patients were divided into two groups: good responders and poor responders to GLP-1 analogues, based on pretreatment and post-treatment HbA1c levels. Good responders were those whose HbA1c level had decreased by 1% or more, or maintained at less than 7%. All other patients were categorized as poor responders. We used univariate and multivariate analyses to assess pretreatment parameters between the two groups.. Approximately 35% of the patients were poor responders. Our analysis of the pretreatment clinical parameters revealed that number of anti-diabetic agents and use of sulfonylurea were significantly associated with poor response to liraglutide (P=0.02 and P=0.03, respectively) in a multivariate analysis. We were not able to find any candidate related to clinical response to exenatide.. Our study showed that the therapeutic effects of GLP-1 analogues on T2DM patients were heterogeneous. T2DM patients who require multiple anti-diabetic agents, especially sulfonylurea, do not benefit from liraglutide treatment. Topics: Adult; Aged; Alanine Transaminase; Anthropometry; Biguanides; Body Weight; Comorbidity; Diabetes Mellitus, Type 2; Drug Therapy, Combination; Exenatide; Female; Glucagon-Like Peptide 1; Glycated Hemoglobin; Humans; Hypoglycemic Agents; Insulin; Insulin Secretion; Liraglutide; Male; Middle Aged; Peptides; Prognosis; Retrospective Studies; Sulfonylurea Compounds; Thiazolidines; Treatment Outcome; Venoms | 2014 |
Two new GLP-1 receptor agonists for diabetes.
Topics: Diabetes Mellitus, Type 2; Drug Approval; Drug Interactions; Drug Therapy, Combination; Glucagon-Like Peptide 1; Glucagon-Like Peptide-1 Receptor; Glucagon-Like Peptides; Humans; Immunoglobulin Fc Fragments; Incretins; Randomized Controlled Trials as Topic; Receptors, Glucagon; Recombinant Fusion Proteins; United States; United States Food and Drug Administration | 2014 |
ACP Journal Club: in metformin-treated type 2 diabetes mellitus, weekly dulaglutide was noninferior to daily liraglutide for HbA1c levels.
Topics: Diabetes Mellitus, Type 2; Female; Glucagon-Like Peptide 1; Glucagon-Like Peptides; Humans; Hypoglycemic Agents; Immunoglobulin Fc Fragments; Male; Recombinant Fusion Proteins | 2014 |
Retrospective study of adherence to glucagon-like peptide-1 receptor agonist therapy in patients with type 2 diabetes mellitus in the United States.
Greater adherence to medications has been broadly demonstrated to be associated with improved clinical outcomes. However, there is limited real-world evidence on adherence to glucagon-like peptide-1 receptor agonist (GLP-1RA) therapy in patients with type 2 diabetes mellitus (T2DM).. This retrospective cohort study used United States administrative claims data to compare adherence to GLP-1RAs in T2DM patients initiating exenatide once weekly (QW), exenatide twice daily (BID), or once-daily liraglutide (initiated therapy = index therapy). Patients were included if they had T2DM, were GLP-1RA-naïve, initiated a GLP-1RA from 02/01/2012-01/31/2013 (date of initiation = index), were ≥18 years at index, and had continuous enrollment for 12 months before (baseline) to 6 months after index (follow-up). Study outcome was index GLP-1RA adherence (proportion of days covered [PDC] during follow-up, dichotomized at ≥80% vs. <80%, and at ≥90% vs. <90%). Multivariable logistic regressions compared adherence between the GLP-1RAs, adjusting for potential confounders. Sensitivity analyses were performed separating liraglutide by dose (1.2 mg/1.8 mg).. Study sample included 4,041 exenatide QW, 4,586 exenatide BID, and 14,211 liraglutide (6,641 1.2 mg, 7,570 1.8 mg) patients. Median unadjusted PDC values were 0.783 for exenatide QW, 0.500 exenatide BID, 0.722 liraglutide, 0.761 liraglutide 1.2 mg, and 0.683 liraglutide 1.8 mg. Compared with patients treated with either exenatide BID or liraglutide, patients treated with exenatide QW had a statistically significantly greater multivariable-adjusted odds of achieving adherence of ≥80% (odds ratio vs. exenatide QW (OR) = 0.41 for exenatide BID; 0.80, liraglutide; 0.87, liraglutide 1.2 mg; 0.75, liraglutide 1.8 mg) and ≥90% (OR = 0.31 for exenatide BID; 0.60 liraglutide; 0.66 liraglutide 1.2 mg; 0.56 liraglutide 1.8 mg) (all P < 0.001).. Patients initiating exenatide QW had significantly higher adjusted odds of adherence compared with patients initiating other GLP-1RAs. Given differences in adherence across the GLP-1RAs, research correlating these factors with clinical and economic outcomes is warranted. Topics: Adult; Aged; Cohort Studies; Diabetes Mellitus, Type 2; Drug Administration Schedule; Exenatide; Female; Glucagon-Like Peptide 1; Glucagon-Like Peptide-1 Receptor; Glycated Hemoglobin; Humans; Hypoglycemic Agents; Liraglutide; Male; Medication Adherence; Middle Aged; Outcome Assessment, Health Care; Peptides; Retrospective Studies; United States; Venoms | 2014 |
[Hypertension and diabetes: target blood pressure and blood pressure lowering by new antidiabetic drugs].
Topics: Antihypertensive Agents; Blood Pressure; Cross-Cultural Comparison; Diabetes Mellitus, Type 2; Glucagon-Like Peptide 1; Guideline Adherence; Humans; Hypertension; Hypoglycemic Agents; Sodium-Glucose Transporter 2 Inhibitors | 2014 |
Effect of the ingestion of the palm oil and glutamine in serum levels of GLP-1, PYY and glycemia in diabetes mellitus type 2 patients submitted to metabolic surgery.
Incretins are hormones produced by the intestine and can stimulate the secretion of insulin, helping to diminish the post-prandial glycemia. The administration of an emulsion of palm oil can help in the maintenance of the weight, and can increase circulating incretins levels. Glutamine increases the concentration of incretins in diabetic people. Both can help in metabolic syndrome.. To analyze the effects of ingestion of palm oil and glutamine in glycemia and in incretins in patients with diabetes submitted to surgical duodenojejunal exclusion with ileal interposition without gastrectomy.. Eleven diabetic type 2 patients were included and were operated. They were called to laboratory follow-up without eating anything between eight and 12 hours. They had there blood collected after the stimulus of the palm oil and glutamine taken in different days. For the hormonal doses were used ELISA kits.. The glycemia showed a meaningful fall between the fast and two hours after the stimulus of the palm oil (p=0,018). With the glutamine the GLP-1 showed an increase between the fast and one hour (p=0,32), the PYY showed an important increase between the fast and one hour after the stimulus (p=0,06), the glycemia showed a meaningful fall after two hours of the administration of the stimulus (p=0,03).. Palm oil and glutamine can influence intestinal peptides and glucose. Topics: Adult; Bariatric Surgery; Blood Glucose; Diabetes Mellitus, Type 2; Eating; Female; Glucagon-Like Peptide 1; Glutamine; Humans; Male; Middle Aged; Palm Oil; Peptide YY; Plant Oils; Young Adult | 2014 |
Prandial insulin versus glucagon-like peptide-1 added to basal insulin: comparative effectiveness in the community practice setting.
Real-world data on emerging combination approaches for type 2 diabetes mellitus (T2DM) management are limited. The objective of the current study was to document the characteristics and clinical outcomes of patients with T2DM initiating prandial insulin or a glucagon-like peptide-1 (GLP-1) receptor agonist while on basal insulin.. This was a retrospective analysis of an electronic medical records database of patients with T2DM managed in a community practice setting in the United States. The main outcome measures were glycated hemoglobin (HbA1c), body weight, hypoglycemia, and health care resource utilization at baseline and at 6-month and 1-year follow-up.. A total of 33 810 patients were included in the study: 31 848 on prandial insulin and 1962 on a GLP-1 receptor agonist. At baseline there were significant differences in mean age (60 vs 56 years), mean Charlson Comorbidity Index score (1.1 vs 0.7), mean HbA1c (8.8% vs 8.4%), and mean body weight (99 vs 112 kg) between the prandial insulin and GLP-1 receptor agonist groups, respectively (P < 0.001 for each). After matching for baseline differences, significant and similar changes from baseline were observed between the prandial insulin and the GLP-1 receptor agonist groups during follow-up at the 6 months/1 year post-index date for HbA1c (-0.45/-0.60% vs -0.44/-0.58%, respectively; P = 0.907/0.723 between groups). Body weight changes between the groups were significantly different at 6 months/1 year (+1.7/-1.7 vs -0.9/-3.7 kg; P < 0.001). Hypoglycemia incidence and health care resource utilization were significantly greater in the prandial insulin versus GLP-1 receptor agonist group.. The results of this real-world analysis of patients with T2DM adding a GLP-1 receptor agonist or prandial insulin to basal insulin suggest an association between adding a GLP-1 receptor agonist with similar glycemic control, greater reduction in body weight, lower hypoglycemia incidence, and lower health care utilization compared with adding prandial insulin. Topics: Aged; Community Health Services; Diabetes Mellitus, Type 2; Drug Administration Schedule; Drug Therapy, Combination; Endocrinology; Family Practice; Female; Glucagon-Like Peptide 1; Glycated Hemoglobin; Humans; Hypoglycemia; Hypoglycemic Agents; Incretins; Insulin; Male; Middle Aged; Retrospective Studies; United States; Weight Gain | 2014 |
The low level of glucagon-like peptide-1 (glp-1) is a risk factor of type 2 diabetes mellitus.
Glucagon like peptide-1 (GLP-1), an incretin hormone, regulates glucose metabolism by inducing insulin secretion and suppressing glucagon secretion. The aim of the study is to assess the levels of fasting and post-prandial GLP-1 and their risk for T2DM. A case control study was conducted at the diabetes clinic Sanglah Hospital Denpasar Bali, involving 40 subjects who were native Indonesian citizens and 18-70 years of age. Twenty subjects were allocated as the case group (subjects with T2DM) and 20 subjects were allocated as the control group (subjects with normal glucose tolerance [NGT]). Both fasting intact GLP-1 (FGLP-1) and 60 minutes post-75 gram glucose loading intact GLP-1 (1hGLP-1) levels were measured.. Both fasting and post-prandial GLP-1 levels were significantly lower in subjects with T2DM than those with NGT (2.06 ± 0.43 vs. 2.87 ± 0.67 pg/L, p < 0.01; and 2.49 ± 0.60 vs. 3.42 ± 0.85 pg/L, p = 0.02; respectively). Low levels of FGLP-1 (OR, 13.5; p = 0.001) and 1hGLP-1 (OR, 5.667, p = 0.018), with no response after glucose loading (∆GLP-1), were a significant risk for T2DM. According to the ∆GLP-1, there was a tendency of decreasing response of GLP-1 after glucose loading among subjects with T2DM (∆ = 0.43 pg/L) compared to subjects with NGT (∆ = 0.55 pg/L).. From this study it can be concluded that levels of intact GLP-1 are an important risk factor for T2DM in the Indonesian population. Topics: Adolescent; Adult; Aged; Case-Control Studies; Diabetes Mellitus, Type 2; Fasting; Glucagon-Like Peptide 1; Glucose Tolerance Test; Humans; Indonesia; Middle Aged; Postprandial Period; Risk Factors; Young Adult | 2014 |
[The physiology of glucagon-like peptide-1 and its role in the pathophysiology of type 2 diabetes mellitus].
The hormone glucagon-like peptide-1 (GLP-1) is synthesized and secreted by L cells in the small intestine in response to food ingestion. After reaching the general circulation it has a half-life of 2-3 minutes due to degradation by the enzyme dipeptidyl peptidase-4. Its physiological role is directed to control plasma glucose concentration, though GLP-1 also plays other different metabolic functions following nutrient absorption. Biological activities of GLP-1 include stimulation of insulin biosynthesis and glucose-dependent insulin secretion by pancreatic beta cell, inhibition of glucagon secretion, delay of gastric emptying and inhibition of food intake. GLP-1 is able to reduce plasma glucose levels in patients with type 2 diabetes and also can restore beta cell sensitivity to exogenous secretagogues, suggesting that the increasing GLP-1 concentration may be an useful therapeutic strategy for the treatment of patients with type 2 diabetes. Topics: Animals; Blood Glucose; Carbohydrate Metabolism, Inborn Errors; Clinical Trials as Topic; Diabetes Mellitus, Type 2; Eating; Gastric Emptying; Gastric Inhibitory Polypeptide; Glucagon; Glucagon-Like Peptide 1; Glucagon-Like Peptide-1 Receptor; Glucose; Homeostasis; Humans; Hyperglycemia; Incretins; Insulin; Insulin Secretion; Insulin-Secreting Cells; Malabsorption Syndromes; Mice; Mice, Knockout; Models, Biological; Obesity; Receptors, Glucagon | 2014 |
[Modulation of the incretin effect in the treatment of diabetes].
Modulation of the incretin effect has opened up a new strategy in the treatment of diabetes mellitus type 2 (DM2). To date, this physiological mechanism has been boosted in two ways: firstly, by pharmacological inhibition of the enzyme that physiologically degrades glucagon-like peptide-1 (GLP-1) receptor agonists, dipeptidyl peptidase-4 (DPP4); secondly, through the development of GLP-1 agonists (GLP-1a) that are resistant to the action of DPP-4. Several clinical trials have shown the clinical superiority of GLPa, which seems to be linked to higher circulating levels of GLP-1. On the other hand, this higher efficacy also seems to be associated with the higher rate of adverse effects associated with aGLP-1 therapy compared with DPP-4 inhibition. These and other differentiating characteristics of the two drug families will determine the choice of drug therapy in the personalized treatment of hyperglycemia in patients with DM2. Topics: Clinical Trials as Topic; Diabetes Mellitus, Type 2; Dipeptidyl Peptidase 4; Dipeptidyl-Peptidase IV Inhibitors; Gastrointestinal Motility; Glucagon-Like Peptide 1; Glucagon-Like Peptide-1 Receptor; Humans; Hypoglycemic Agents; Incretins; Models, Biological; Precision Medicine; Receptors, Glucagon; Spain | 2014 |
[Extrapancreatic effects of GLP-1 receptor agonists: an open window towards new treatment goals in type 2 diabetes].
The wide ubiquity of GLP-1 receptors in the body has stimulated the search for different extrapancreatic actions of GLP-1 and its receptor agonists. Thus, severe cardioprotective effects directed on myocardial ischaemia and dysfunction as well as diverse antiaterogenic actions have been reported. Also, native and GLP-1 receptor agonists have demonstrated significant beneficial effects on liver steatosis and fibrosis and on neuronal protection in experimental models of Alzheimer, and Parkinson's disease as well as on cerebral ischaemia. Recent evidences suggest that these drugs may also be useful for prevention and treatment of diabetic retinopathy, nephropathy and peripheral neuropathy. Good results have also been reported in psoriasis. Despite we still need confirmation that these promising effects can be applied to clinical practice, they offer new interesting perspectives for treatment of type 2 diabetes associated complications and give to GLP-1 receptor agonists an even more integral position in diabetes therapy. Topics: Animals; Anti-Inflammatory Agents; Anti-Obesity Agents; Cardiotonic Agents; Cardiovascular Diseases; Clinical Trials as Topic; Diabetes Mellitus, Type 2; Disease Models, Animal; Endothelium, Vascular; Glucagon-Like Peptide 1; Glucagon-Like Peptide-1 Receptor; Humans; Hypoglycemic Agents; Insulin Resistance; Kidney Diseases; Lipid Metabolism; Liver Diseases; Multicenter Studies as Topic; Nervous System Diseases; Neuroprotective Agents; Organ Specificity; Receptors, Glucagon; Recombinant Proteins | 2014 |
Predictors of response to liraglutide in Japanese type 2 diabetes.
In Japan, liraglutide is approved for use alone or in combination with sulfonylureas, and the approved maximum dosage is 0.9 mg/day. This restriction could limit the glucose-lowering effect of liraglutide in Japanese patients with type 2 diabetes mellitus (T2DM). This study was designed to identify predictors of response to liraglutide therapy at the approved dosage.. This observational retrospective study included 380 patients with T2DM who were treated with liraglutide alone or in combination with sulfonylureas at Diabetes Centers located in four geographically different areas of Japan. Binary logistic regression analysis was used to identify patient characteristics associated with discontinuation of liraglutide, while multiple regression and decision tree analyses were used to identify predictors of response to liraglutide therapy.. Factors associated with discontinuation of liraglutide included high BMI, long duration of diabetes, and prior insulin therapy. Predictors of response to liraglutide therapy in patients who did not use insulin previously included previous use of few oral glucose-lowering agents and high baseline HbA1c level.. The results suggest greater efficacy of liraglutide monotherapy or liraglutide-sulfonylurea combination therapy in patients with short duration of diabetes, non-insulin therapy, and low BMI and high HbA1c level at baseline. Topics: Diabetes Mellitus, Type 2; Dose-Response Relationship, Drug; Female; Follow-Up Studies; Glucagon-Like Peptide 1; Glycated Hemoglobin; Humans; Hypoglycemic Agents; Incidence; Japan; Liraglutide; Male; Middle Aged; Retrospective Studies; Treatment Outcome | 2014 |
Once-yearly device takes on daily and weekly diabetes drugs.
Topics: Diabetes Mellitus, Type 2; Drug Delivery Systems; Exenatide; Glucagon-Like Peptide 1; Humans; Peptides; Venoms | 2014 |
[New medications for patients with type 2 diabetes].
Type 2 diabetes is characterised by insulin resistance and deficiencywhich explains the multitude of molecules developed for its treatment.The beneficial effects of metformin and sulfamides have been demonstrated. Over the last 10 years, new molecules have appeared: acarbose, repaglinide and incretins. Topics: Carbamates; Diabetes Mellitus, Type 2; Dipeptidyl-Peptidase IV Inhibitors; Drug Therapy, Combination; Glucagon-Like Peptide 1; Glycoside Hydrolase Inhibitors; Humans; Hypoglycemic Agents; Incretins; Piperidines | 2014 |
Can early use of insulin, GLP-1 halt diabetes progression?
Topics: Diabetes Mellitus, Type 2; Disease Progression; Glucagon-Like Peptide 1; Humans; Hypoglycemic Agents; Insulin; Liraglutide | 2014 |
A prospective study of concomitant GLP-1 analogue and insulin use in type 2 diabetes in clinical practice.
A small number of studies have shown a significant reduction in HbA1c, weight and total daily insulin dose when a glucagon-like-peptide-1 (GLP-1) analogue was added in type 2 diabetes patients already on insulin treatment. Therefore, in a clinical setting, we investigated the effect of adding GLP-1 analogues in patients with type 2 diabetes already using insulin with respect to glycaemic control, body weight and insulin dose.. In this prospective hospital-based study, we included 125 patients suffering from type 2 diabetes, treated with insulin and with a body mass index ≥ 35 kg/m2, who had started on GLP-1 analogues (liraglutide/exenatide). HbA1c, body weight, daily insulin dose, and side effects were registered at baseline, and after three, six and 12 months.. HbA1c and weight decreased significantly at all the timepoints (p ≤ 0.001 compared with baseline; HbA1c: -5.5 mmol/mol (-0.5%) and weight: -14.3 kg after 12 months), with the largest decrease in the first three months. No significant correlation was found between weight loss and HbA1c reduction, and between duration of diabetes and both weight loss and HbA1c reduction. After six and 12 months, the total daily insulin dose decreased significantly (p < 0.001, -75.4 IU after 12 months). Moreover, 34% of the patients were able to stop using insulin therapy after 12 months.. By adding a GLP-1 analogue in obese patients with type 2 diabetes already on insulin therapy, a significant reduction of HbA1c levels and body weight, and a significant reduction in insulin dose or complete discontinuation of insulin can be achieved. Topics: Adult; Aged; Body Mass Index; Diabetes Mellitus, Type 2; Exenatide; Female; Glucagon-Like Peptide 1; Glycated Hemoglobin; Humans; Hypoglycemic Agents; Insulin; Liraglutide; Male; Middle Aged; Obesity; Peptides; Prospective Studies; Venoms; Weight Loss; Young Adult | 2014 |
Improvement in psoriasis after treatment with the glucagon-like peptide-1 receptor agonist liraglutide.
A 59-year old man with moderate and stable psoriasis through 15 years was admitted to our Department with inadequately controlled type 2 diabetes. Treatment was initiated with the glucagon-like peptide-1 receptor (GLP-1R) agonist liraglutide. The patient experienced marked improvement in his psoriasis immediately after the start of liraglutide treatment. Itching stopped within days, scaling was reduced and spots of normal skin emerged. After 3 months, psoriasis was still improving. Excellent glycaemic control and a weight loss of approximately 8 kg over 3 months were moreover obtained. The patient had previously been well controlled in his diabetes without improvement in psoriasis, and the effect of liraglutide on psoriasis started before weight loss occurred. We discuss the possibility of a direct anti-inflammatory effect of liraglutide in psoriasis as well as indirect effects through improvement in comorbidities such as overweight. Randomized clinical trials are needed to reveal whether GLP-1R agonists represent a new therapeutic option for psoriasis. Topics: Diabetes Mellitus, Type 2; Glucagon-Like Peptide 1; Glucagon-Like Peptide-1 Receptor; Humans; Liraglutide; Male; Middle Aged; Psoriasis; Receptors, Glucagon; Treatment Outcome | 2014 |
Effects of sitagliptin beyond glycemic control: focus on quality of life.
Recently, incretin hormones, including glucagon-like peptide-1 (GLP-1) analogue and dipeptidyl peptidase-4 (DPP-4) inhibitor, have been found to regulate glucose metabolism. The aim of this study was to elucidate the efficacy and safety of the clinical usage of DPP-4 inhibitors in Japan.. This study was designed as a prospective, open-label, multi-center trial. Patients with diabetes mellitus type 2 (T2DM) with poor glycemic profiles (HbA1c ≥ 6.2%) in spite of receiving a medical diet, therapeutic exercise, and/or medications were eligible for this study. The participants received 50 to 100 mg of the DPP-4 inhibitor sitagliptin once daily for 12 months.. One hundred and eighty-eight subjects were enrolled. After 12 months of sitagliptin treatment, HbA1c levels decreased (7.65% ± 1.32% to 7.05% ± 1.10%, p < 0.001) as well as fasting plasma glucose (FPG) (145 ± 52 mg/dl to 129 ± 43 mg/dl, p = 0.005). The rate of glycemic control achieved (in accordance with the guidelines of the Japanese Diabetes Society) significantly increased. Blood pressure and serum levels of triglycerides and total cholesterol decreased significantly. Furthermore, the Pittsburgh Sleep Quality Index (PSQI) and Diabetes Symptomatic Scores improved significantly. Adverse events such as hypoglycemia and loss of consciousness occurred in twenty three subjects (11%).. These results suggest that the actions of DPP-4 inhibitors improve not only glycemic control, but also blood pressure, lipid profiles, and quality of life (QOL). Sitagliptin is a sound agent for use in the comprehensive treatment of patients with T2DM. Topics: Aged; Blood Glucose; Diabetes Mellitus, Type 2; Dipeptidyl-Peptidase IV Inhibitors; Female; Glucagon-Like Peptide 1; Glycemic Index; Humans; Hypoglycemic Agents; Male; Middle Aged; Prospective Studies; Pyrazines; Quality of Life; Sitagliptin Phosphate; Treatment Outcome; Triazoles | 2013 |
Long-term effectiveness and safety of liraglutide in clinical practice.
The rising adoption of liraglutide in clinical practice calls for an update on its long-term effectiveness and safety. The aims of this paper were to review characteristics of patients treated with liraglutide under routine clinical practice conditions, to describe therapeutic schemes, to assess the durability of liraglutide after two years of therapy, to evaluate changes in clinical parameters obtained after 20-24 months and to identify elective phenotype of patients that are able to respond better to this treatment.. One diabetes outpatient clinic in Italy systematically collected data of patients receiving liraglutide every four months during a two-year follow-up. Mean levels and changes vs. baseline of HbA1c, fasting blood glucose (FBG), body weight, body mass index, waist circumference, blood pressure and lipid profile were evaluated. Rate of treatment discontinuation and side effects were also investigated.. Overall, 205 patients were analyzed. Liraglutide was prescribed as an add-on drug in 39% of patients and as a replacement in 61%. It was used both in patients with short (21% ≤5 years) and long (32% >15 years) diabetes duration and both in obese and non-obese individuals (38% BMI≤30 Kg/m2). Liraglutide was used within many different therapeutic schemes, also including insulin (20%). On average, HbA1c levels were reduced of 1% vs. baseline at each visit, but magnitude of reduction was inversely related to diabetes duration, i.e., to the preservation of beta-cell function. However, clinically relevant improvements of glycaemic control were obtained and sustained during two years in all subgroups of patients, despite of classes of diabetes duration, BMI and antidiabetic therapeutic regimen. Durability of effectiveness on body weight and waist circumference was also documented. Liraglutide treatment was also associated with a reduction of systolic blood pressure and improvement of lipid profile. Side effects, that occurred in 20% of patients during the first four months of treatment, decreased at 2% at 20 months. The rate of drop-out was 16.1% of the patients treated.. The analysis of our clinical practice shows that treatment with liraglutide was safe, well tolerated and effective in reducing HbA1c, fasting blood glucose and body weight significantly, with positive effects on systolic blood pressure and lipid profile. Therefore, results of LEAD studies are substantially reproduced in the context of routine clinical practice. Even if the maximum effectiveness of liraglutide occurs in patients with short disease duration, preferably treated with metformin, also in patients with long duration of disease, treated with several drugs or in insulin therapy, the use of this GLP-1 analogue allows to obtain more than satisfactory results. Improvements in metabolic control and body weight are maintained after two years, suggesting durability and safety of liraglutide in the long run. Topics: Aged; Ambulatory Care Facilities; Blood Glucose; Blood Pressure; Body Mass Index; Body Weight; Cardiovascular Diseases; Cholesterol, HDL; Cholesterol, LDL; Diabetes Mellitus, Type 2; Female; Follow-Up Studies; Glucagon-Like Peptide 1; Glycated Hemoglobin; Humans; Hypoglycemic Agents; Lipids; Liraglutide; Male; Middle Aged; Obesity; Retrospective Studies; Risk Factors; Treatment Outcome; Triglycerides; Waist Circumference | 2013 |
Glucagonlike peptide 1-based therapies and risk of hospitalization for acute pancreatitis in type 2 diabetes mellitus: a population-based matched case-control study.
Acute pancreatitis has significant morbidity and mortality. Previous studies have raised the possibility that glucagonlike peptide 1 (GLP-1)-based therapies, including a GLP-1 mimetic (exenatide) and a dipeptidyl peptidase 4 inhibitor (sitagliptin phosphate), may increase the risk of acute pancreatitis.. To test whether GLP-1-based therapies such as exenatide and sitagliptin are associated with an increased risk of acute pancreatitis. We used conditional logistic regression to analyze the data.. Population-based case-control study.. A large administrative database in the United States from February 1, 2005, through December 31, 2008.. Adults with type 2 diabetes mellitus aged 18 to 64 years. We identified 1269 hospitalized cases with acute pancreatitis using a validated algorithm and 1269 control subjects matched for age category, sex, enrollment pattern, and diabetes complications.. Hospitalization for acute pancreatitis.. The mean age of included individuals was 52 years, and 57.45% were male. Cases were significantly more likely than controls to have hypertriglyceridemia (12.92% vs 8.35%), alcohol use (3.23% vs 0.24%), gallstones (9.06% vs 1.34), tobacco abuse (16.39% vs 5.52%), obesity (19.62% vs 9.77%), biliary and pancreatic cancer (2.84% vs 0%), cystic fibrosis (0.79% vs 0%), and any neoplasm (29.94% vs 18.05%). After adjusting for available confounders and metformin hydrochloride use, current use of GLP-1-based therapies within 30 days (adjusted odds ratio, 2.24 [95% CI, 1.36-3.68]) and recent use past 30 days and less than 2 years (2.01 [1.37-3.18]) were associated with significantly increased odds of acute pancreatitis relative to the odds in nonusers.. In this administrative database study of US adults with type 2 diabetes mellitus, treatment with the GLP-1-based therapies sitagliptin and exenatide was associated with increased odds of hospitalization for acute pancreatitis. Topics: Acute Disease; Adolescent; Adult; Case-Control Studies; Diabetes Mellitus, Type 2; Dipeptidyl-Peptidase IV Inhibitors; Exenatide; Female; Glucagon-Like Peptide 1; Hospitalization; Humans; Logistic Models; Male; Middle Aged; Pancreatitis; Peptides; Pyrazines; Risk Factors; Sitagliptin Phosphate; Triazoles; Venoms | 2013 |
Glucagonlike Peptide 1-based drugs and pancreatitis: clarity at last, but what about pancreatic cancer?
Topics: Diabetes Mellitus, Type 2; Female; Glucagon-Like Peptide 1; Hospitalization; Humans; Male; Pancreatitis | 2013 |
On-target effects of GLP-1 receptor agonists on thyroid C-cells in rats and mice.
Glucagon-like peptide-1 is an incretin hormone from the gastrointestinal tract, which enhances insulin secretion, slows gastric emptying, and reduces food intake. GLP-1 receptor agonists are being developed for Type 2 diabetes mellitus. GLP-1 is rapidly degraded by serum dipeptidyl peptidase IV, so analogues with a prolonged serum half-life are used clinically. Exenatide was the first GLP-1 agonist approved and is a synthetic version of exendin-4 derived from the Gila monster. Liraglutide was approved for clinical use in 2010. GLP-1 receptor agonists have been shown to increase calcitonin secretion and stimulate C-cell hyperplasia and neoplasia in rats and mice of both sexes. Rat C-cells are more sensitive to the effects of GLP-1 agonists than mice. The effects of GLP-1 agonists on C-cell proliferation or neoplasia have not been documented in nonhuman primates or humans. The proliferative C-cell effects may be rodent-specific. GLP-1 receptors have been demonstrated on normal rodent C-cells, but are either not present or occur in low numbers on C-cells of nonhuman primates and humans. Hyperplasia and neoplasia of C-cells in rodents treated with GLP-1 agonists represent a unique example of an on-target species-specific effect that may not have relevance to humans. Topics: Animals; Diabetes Mellitus, Type 2; Exenatide; Glucagon-Like Peptide 1; Glucagon-Like Peptide-1 Receptor; Humans; Hyperplasia; Hypoglycemic Agents; Immunohistochemistry; Liraglutide; Mice; Peptides; Rats; Receptors, Glucagon; Thyroid Gland; Thyroid Neoplasms; Venoms | 2013 |
Hyperlipidaemia and cardiovascular disease -- newer antihyperglycaemic agents and cardiovascular disease.
Topics: Benzhydryl Compounds; Blood Pressure; Cardiovascular Diseases; Clinical Trials as Topic; Diabetes Mellitus, Type 2; Glucagon-Like Peptide 1; Glucosides; Humans; Hyperlipidemias; Hypoglycemic Agents; Risk Factors; Sodium-Glucose Transporter 2; Sodium-Glucose Transporter 2 Inhibitors; Treatment Outcome | 2013 |
Systemic bile acid sensing by G protein-coupled bile acid receptor 1 (GPBAR1) promotes PYY and GLP-1 release.
Nutrient sensing in the gut is believed to be accomplished through activation of GPCRs expressed on enteroendocrine cells. In particular, L-cells located predominantly in distal regions of the gut secrete glucagon-like peptide 1 (GLP-1) and peptide tyrosine-tyrosine (PYY) upon stimulation by nutrients and bile acids (BA). The study was designed to address the mechanism of hormone secretion in L-cells stimulated by the BA receptor G protein-coupled bile acid receptor 1 (GPBAR1).. A novel, selective, orally bioavailable, and potent GPBAR1 agonist, RO5527239, was synthesized in order to investigate L-cell secretion in vitro and in vivo in mice and monkey. In analogy to BA, RO5527239 was conjugated with taurine to reduce p.o. bioavailability yet retaining its potency. Using RO5527239 and tauro-RO5527239, the acute secretion effects on L-cells were addressed via different routes of administration.. GPBAR1 signalling triggers the co-secretion of PYY and GLP-1, and leads to improved glucose tolerance. The strong correlation of plasma drug exposure and plasma PYY levels suggests activation of GPBAR1 from systemically accessible compartments. In contrast to the orally bioavailable agonist RO5527239, we show that tauro-RO5527239 triggers PYY release only when applied intravenously. Compared to mice, a slower and more sustained PYY secretion was observed in monkeys.. Selective GPBAR1 activation elicits a strong secretagogue effect on L-cells, which primarily requires systemic exposure. We suggest that GPBAR1 is a key player in the intestinal proximal-distal loop that mediates the early phase of nutrient-evoked L-cell secretion effects. Topics: Animals; Cell Line; CHO Cells; Cricetulus; Diabetes Mellitus, Type 2; Enteroendocrine Cells; Gastrointestinal Agents; Glucagon-Like Peptide 1; Humans; Hypoglycemic Agents; Isonipecotic Acids; Macaca fascicularis; Male; Metabolic Detoxication, Phase II; Mice; Mice, Mutant Strains; Mice, Transgenic; Oximes; Peptide YY; Piperidines; Receptors, G-Protein-Coupled; Recombinant Proteins; Taurine | 2013 |
FDA is to assess data linking type 2 diabetes drugs with pancreatitis.
Topics: Databases, Factual; Diabetes Mellitus, Type 2; Glucagon-Like Peptide 1; Humans; Hypoglycemic Agents; Pancreatic Neoplasms; Pancreatitis; Precancerous Conditions; Risk Assessment; United States; United States Food and Drug Administration | 2013 |
Incretins: what is known, new and controversial in 2013?
Glucagon-like peptide (GLP)-1 action involves both endocrine and neural pathways to control peripheral tissues. In diabetes the impairment of either pathway may define different subsets of patients: some may be better treated with GLP-1 receptor agonists that are more likely to directly stimulate beta-cells and extrapancreatic receptors, while others may benefit from dipeptidyl peptidase (DPP)-4 inhibitor treatments that are more likely to increase the neural gut-brain-pancreas axis. Elevated plasma concentrations of GLP-1 associated with agonist treatment or bariatric surgery also appear to exert neuroprotective effects, ameliorate postprandial and fasting lipids, improve heart physiology and protect against heart failure, thereby expanding the possible positioning of GLP-1-based therapies. However, the mechanisms behind GLP-1 secretion, the role played by proximal and distal intestinal GLP-1-producing cells as well as the molecular basis of GLP-1 resistance in diabetes are still to be ascertained. The pharmacological features distinguishing GLP-1 receptor agonists from DPP-4 inhibitors are discussed here to address their respective positions in type 2 diabetes. Topics: Bariatric Surgery; Cardiovascular Diseases; Diabetes Mellitus, Type 2; Diabetic Angiopathies; Dipeptidyl-Peptidase IV Inhibitors; Fasting; Female; Glucagon-Like Peptide 1; Humans; Incretins; Lipids; Male | 2013 |
Endoscopic duodenal-jejunal bypass liner rapidly improves type 2 diabetes.
Bariatric procedures excluding the proximal small intestine improve glycemic control in type 2 diabetes within days. To gain insight into the mediators involved, we investigated factors regulating glucose homeostasis in patients with type 2 diabetes treated with the novel endoscopic duodenal-jejunal bypass liner (DJBL).. Seventeen obese patients (BMI 30-50 kg/m(2)) with type 2 diabetes received the DJBL for 24 weeks. Body weight and type 2 diabetes parameters, including HbA1c and plasma levels of glucose, insulin, glucagon-like peptide-1 (GLP-1), glucose-dependent insulinotropic polypeptide (GIP), and glucagon, were analyzed after a standard meal before, during, and 1 week after DJBL treatment.. At 24 weeks after implantation, patients had lost 12.7 ± 1.3 kg (p < 0.01), while HbA1c had improved from 8.4 ± 0.2 to 7.0 ± 0.2 % (p < 0.01). Both fasting glucose levels and the postprandial glucose response were decreased at 1 week after implantation and remained decreased at 24 weeks (baseline vs. week 1 vs. week 24: 11.6 ± 0.5 vs. 9.0 ± 0.5 vs. 8.6 ± 0.5 mmol/L and 1,999 ± 85 vs. 1,536 ± 51 vs. 1,538 ± 72 mmol/L/min, both p < 0.01). In parallel, the glucagon response decreased (23,762 ± 4,732 vs. 15,989 ± 3,193 vs. 13,1207 ± 1,946 pg/mL/min, p < 0.05) and the GLP-1 response increased (4,440 ± 249 vs. 6,407 ± 480 vs. 6,008 ± 429 pmol/L/min, p < 0.01). The GIP response was decreased at week 24 (baseline-115,272 ± 10,971 vs. week 24-88,499 ± 10,971 pg/mL/min, p < 0.05). Insulin levels did not change significantly. Glycemic control was still improved 1 week after explantation.. The data indicate DJBL to be a promising treatment for obesity and type 2 diabetes, causing rapid improvement of glycemic control paralleled by changes in gut hormones. Topics: Adolescent; Adult; Aged; Area Under Curve; Bariatric Surgery; Blood Glucose; Body Mass Index; Diabetes Mellitus, Type 2; Duodenum; Eating; Endoscopy; Fasting; Female; Gastric Inhibitory Polypeptide; Glucagon; Glucagon-Like Peptide 1; Glycated Hemoglobin; Humans; Insulin; Insulin Secretion; Jejunum; Male; Middle Aged; Netherlands; Obesity; Pilot Projects; Postprandial Period; Remission Induction; Time Factors; Treatment Outcome; Weight Loss | 2013 |
The role of medicinal chemistry in treating obesity, diabetes and metabolic syndrome.
Topics: Chemistry, Pharmaceutical; Diabetes Mellitus, Type 2; Glucagon-Like Peptide 1; Humans; Hypoglycemic Agents; Liraglutide; Metabolic Syndrome; Metformin; Obesity | 2013 |
Hyperplasia from GLP-1 drugs is "not a surprise," say researchers.
Topics: Diabetes Mellitus, Type 2; Glucagon-Like Peptide 1; Humans; Hyperplasia; Incretins; Metaplasia; Pancreas; Pancreatic Neoplasms; Pancreatitis | 2013 |
Evaluating the short-term cost-effectiveness of liraglutide versus sitagliptin in patients with type 2 diabetes failing metformin monotherapy in the United States.
Effective glycemic control can reduce the risk of serious micro- and macrovascular complications in type 2 diabetes. However, many patients fail to reach glycemic targets due partly to low efficacy and adverse effects of treatment such as hypoglycemia or weight gain.. To evaluate the short-term cost-effectiveness of liraglutide versus sitagliptin, in terms of cost per patient reaching a glycated hemoglobin (HbA1c) target with no hypoglycemia and no weight gain after 52 weeks, based on a recently published trial. . Data were taken from a 52-week randomized, controlled trial (NCT00700817) in which adults with type 2 diabetes (mean age = 55 years, HbA1c = 8.4%, body mass index = 33 kg/m2) failing metformin monotherapy were randomly allocated to receive either liraglutide 1.2 mg, liraglutide 1.8 mg, or sitagliptin 100 mg daily, in addition to metformin. For the cost-effectiveness analysis, the proportion of patients achieving a clinically relevant composite endpoint, defined as HbA1c less than 7.0%, with no reported hypoglycemia and no gain in body weight, was estimated using logistic regression. Trial data showed that 38.9% of patients on liraglutide 1.2 mg and 49.9% on liraglutide 1.8 mg achieved the composite endpoint, compared with 18.6% on sitagliptin at 52 weeks. Costs of antihyperglycemia medications were accounted for based on published wholesale acquisition costs in 2012 U.S. dollars. . Overall pharmacy costs (needle costs included) were higher for patients on liraglutide than sitagliptin. The cost per patient achieving an HbA1c less than 7% was lowest for patients receiving liraglutide 1.2 mg ($7,993) and highest for patients receiving sitagliptin ($11,570). When expressed as the mean cost per patient reaching target HbA1c with no hypoglycemia or weight gain (cost of control), costs were notably lower on liraglutide than on sitagliptin. Annual mean costs of control were $10,335 on liraglutide 1.2 mg and $11,755 on liraglutide 1.8 mg versus $16,858 on sitagliptin.. The mean cost per patient achieving control, defined as reaching HbA1c target with no hypoglycemia or weight gain, was lower with liraglutide than with sitagliptin based on data from a recently published 52-week clinical trial. Topics: Cost-Benefit Analysis; Diabetes Mellitus, Type 2; Drug Substitution; Glucagon-Like Peptide 1; Glycemic Index; Health Care Costs; Humans; Hypoglycemic Agents; Liraglutide; Metformin; Middle Aged; Pyrazines; Randomized Controlled Trials as Topic; Sitagliptin Phosphate; Treatment Failure; Triazoles; United States | 2013 |
GLP-1 receptor activation and Epac2 link atrial natriuretic peptide secretion to control of blood pressure.
Glucagon-like peptide-1 receptor (GLP-1R) agonists exert antihypertensive actions through incompletely understood mechanisms. Here we demonstrate that cardiac Glp1r expression is localized to cardiac atria and that GLP-1R activation promotes the secretion of atrial natriuretic peptide (ANP) and a reduction of blood pressure. Consistent with an indirect ANP-dependent mechanism for the antihypertensive effects of GLP-1R activation, the GLP-1R agonist liraglutide did not directly increase the amount of cyclic GMP (cGMP) or relax preconstricted aortic rings; however, conditioned medium from liraglutide-treated hearts relaxed aortic rings in an endothelium-independent, GLP-1R-dependent manner. Liraglutide did not induce ANP secretion, vasorelaxation or lower blood pressure in Glp1r(-/-) or Nppa(-/-) mice. Cardiomyocyte GLP-1R activation promoted the translocation of the Rap guanine nucleotide exchange factor Epac2 (also known as Rapgef4) to the membrane, whereas Epac2 deficiency eliminated GLP-1R-dependent stimulation of ANP secretion. Plasma ANP concentrations were increased after refeeding in wild-type but not Glp1r(-/-) mice, and liraglutide increased urine sodium excretion in wild-type but not Nppa(-/-) mice. These findings define a gut-heart GLP-1R-dependent and ANP-dependent axis that regulates blood pressure. Topics: Animals; Aorta; Atrial Natriuretic Factor; Blood Pressure; Cyclic GMP; Diabetes Mellitus, Type 2; Endothelium, Vascular; Gene Expression Regulation; Glucagon-Like Peptide 1; Glucagon-Like Peptide-1 Receptor; Guanine Nucleotide Exchange Factors; Liraglutide; Male; Mice; Mice, Inbred C57BL; Mice, Knockout; Natriuretic Peptide, C-Type; Perfusion; Protein Precursors; Receptors, Glucagon; Vasodilation | 2013 |
Effects of transoral gastroplasty on glucose homeostasis in obese subjects.
Transoral gastroplasty (TOGA) is a safe and less invasive procedure than traditional bariatric surgery. We studied the effects of TOGA on the risk of progression from prediabetes to overt type 2 diabetes mellitus (T2DM) or on regression from diabetes or prediabetes to a lower risk category.. Prospective, observational study (October 2008 to October 2010) performed at Catholic University, Rome, Italy. Fifty consecutive subjects 18-60 years old, 35 ≥ body mass index < 55 kg/m², were enrolled. Glucose tolerance, insulin sensitivity, and secretion were studied at baseline and 1 week and 1, 6, and 12 months after TOGA. Plasma glucagon-like peptide-1 (GLP-1), glucose-dependent insulinotropic peptide (GIP), and ghrelin levels were measured.. Forty-three patients (86%) completed the 1-year postoperative follow-up. Patients lost 16.90% of baseline weight (P level × factor time <0.001). Body mass index decreased from 42.24 ± 3.43 to 34.65 ± 4.58 kg/m² (P < .001). Twenty-three patients (53.5%) were diagnosed as normal glucose tolerance (NGT) before treatment, 2 (4.6%) were impaired fasting glucose (IFG), 12 (27.9%) were impaired glucose tolerance (IGT), 1 (2.3%) had both IFG and IGT, and 5 (11.6%) had T2DM. At 1-year posttreatment, the percentages changed to 86.0% NGT, 2.3% IFG, 11.6% IGT, 0% IFG plus IGT, and 0% T2DM, respectively. Peripheral insulin resistance and homeostasis model of assessment-insulin resistance improved significantly. Fasting glucose-dependent insulinotropic peptide and ghrelin decreased from 316.9 ± 143.1 to 156.2 ± 68.2 pg/mL (P < .001) and from 630.6 ± 52.1 to 456.7 ± 73.1 pg/mL (P < .001), respectively, whereas GLP-1 increased from 16.2 ± 4.9 to 23.7 ± 9.5 pg/mL (P < .001).. TOGA induced glucose disposal improvement with regression of diabetes to NGT or IGT and regression of IGT and IFG to NGT in half of the cases. Regressors showed a much larger increase of GLP-1 levels than progressors. Topics: Adolescent; Adult; Body Mass Index; Coronary Disease; Diabetes Mellitus, Type 2; Disease Progression; Follow-Up Studies; Gastric Inhibitory Polypeptide; Gastroplasty; Ghrelin; Glucagon-Like Peptide 1; Humans; Insulin Resistance; Middle Aged; Obesity; Obesity, Morbid; Prediabetic State; Prospective Studies; Risk; Rome; Weight Loss; Young Adult | 2013 |
GLP-1 and the long-term outcome of type 2 diabetes mellitus after Roux-en-Y gastric bypass surgery in morbidly obese subjects.
To evaluate the association between glucagon-like peptide 1 (GLP-1) secretion and the long-term (>2 years) outcome of type 2 diabetes mellitus (T2DM) after Roux-en-Y gastric bypass (RYGBP).. Cross-sectional study in 18 T2DM morbidly obese subjects who underwent RYGBP but differed in the long-term outcome of T2DM (remission: G1, n = 6; relapse: G2, n = 6; lack of remission: G3: n = 6). Groups were matched for their sex, age, and body mass index. The GLP-1, glucose, C-peptide, and glucagon responses to a standardized test meal (STM) were evaluated. Insulin secretion and insulin sensitivity were estimated from the STM and by frequently sampling intravenous glucose tolerance test (FSIVGTT). Dual-energy X-ray absorptiometry was used to assess body composition.. Patients in G1 presented a lower area under the curve (AUC0-120) of glucose in response to the STM as compared with G2, and G3 (P < 0.01). In contrast, the AUC0-120 of GLP-1 (P = 0.884) and glucagon (P = 0.630) did not differ significantly among the 3 groups. Indices of insulin secretion adjusted by the prevailing insulin sensitivity derived from STM and FSIVGTT, demonstrated larger β-cell function in subjects in G1 as compared with G2 or G3 (Disposition Index-STM, P = 0.005; DI-FSIVGTT, P = 0.006). Body composition and inflammatory markers did not differ significantly among the 3 study groups.. Our data show that in subjects with T2DM an enhanced GLP-1 response to meal intake is not sufficient to maintain normal glucose tolerance in the long term after RYGBP. Our data suggest that β-cell function is a key determinant of the long-term remission of T2DM after this bariatric surgery technique. Topics: Absorptiometry, Photon; Aged; Biomarkers; Blood Glucose; Body Composition; C-Peptide; Cross-Sectional Studies; Diabetes Mellitus, Type 2; Female; Follow-Up Studies; Gastric Bypass; Glucagon; Glucagon-Like Peptide 1; Glucose Tolerance Test; Humans; Insulin; Insulin Resistance; Male; Middle Aged; Obesity, Morbid; Treatment Outcome | 2013 |
Effects of short-term intensive glycemic control on insulin, glucagon, and glucagon-like peptide-1 secretion in patients with Type 2 diabetes.
Short-term intensive insulin therapy (IIT) in patients with Type 2 diabetes mellitus (T2DM) has beneficial effects on insulin secretion. However, IIT effect on glucagon and glucagon-like peptide-1 (GLP-1) secretion is unknown.. We evaluated short-term intensive glycemic control effects on insulin, glucagon, and GLP-1 secretory dynamics in T2DM.. Twenty-six patients with T2DM were hospitalized and treated with IIT for 10-14 days. A meal tolerance test was performed before and after IIT and the differences in serum immunoreactive insulin (IRI) and C-peptide immunoreactivity (CPR) as well as plasma glucagon and active GLP-1 levels were evaluated.. Glycoalbumin levels decreased significantly from 23.0% before to 19.6% after IIT (p<0.001). However, pre- and post-IIT, IRI and CPR levels were not significantly different; post-IIT glucose levels were significantly decreased. The post-IIT glucagon levels at 0 and 60 min were lower than pre-IIT levels. Moreover, post- IIT area under the curve (AUC) of glucagon significantly reduced from 6755 ± 996 pg/dl · 60 min to 5796 ± 1074 pg/dl · 60 min (p<0.001). Furthermore, post-IIT GLP-1 levels and AUC were significantly higher than pre-IIT values.. Our results suggest that patients with T2DM who received shortterm IIT demonstrated decreased postprandial glucagon levels and increased GLP-1 levels following a meal tolerance test. Topics: Adult; Aged; Aged, 80 and over; Blood Glucose; C-Peptide; Diabetes Mellitus, Type 2; Female; Glucagon; Glucagon-Like Peptide 1; Humans; Insulin; Insulin Secretion; Male; Middle Aged | 2013 |
Mechanism of Roux-en-Y gastric bypass treatment for type 2 diabetes in rats.
Roux-en-Y gastric bypass (RYGB) is a novel therapy for diabetes. We aimed to explore the therapeutic mechanism of RYGB.. After RYGB, animal models were established, and gene expression profile of islets was assessed. Additionally, gastrointestinal hormones were measured using enzyme-linked immunosorbent assays. Ca(2+) was studied using confocal microscopy and patch-clamp technique. The morphology of islets and beta cells was observed using optical microscopy and electron microscopy.. RYGB was an effective treatment in diabetic rats. Expression profiling data showed that RYGB produced a new metabolic environment and that gene expression changed to adapt to the new environment. The differential expression of genes associated with hormones, Ca(2+) and cellular proliferation was closely related to RYGB and diabetes metabolism. Furthermore, the data verified that RYGB led to changes in hormone level and enhanced Ca(2+) concentration changes and Ca(2+) channel activity. Morphological data showed that RYGB induced the proliferation of islets and improved the function of beta cells.. RYGB promoted a new metabolic environment while triggering changes to adapt to the new environment. These changes promoted the cellular proliferation of islets and improved the function of beta cells. The quantity of beta cells increased, and their quality improved, ultimately leading to insulin secretion enhancement. Topics: Animals; Calcium; Calcium Channels; Cell Proliferation; Cells, Cultured; Diabetes Mellitus, Type 2; Gastric Bypass; Ghrelin; Glucagon-Like Peptide 1; Insulin; Insulin-Secreting Cells; Islets of Langerhans; Male; Oligonucleotide Array Sequence Analysis; Rats; Rats, Wistar; RNA; Transcriptome | 2013 |
Colonic delivery of docosahexaenoic acid improves impaired glucose tolerance via GLP-1 secretion and suppresses pancreatic islet hyperplasia in diabetic KK-A(y) mice.
Glucagon-like peptide-1 (GLP-1) is an incretin hormone that regulates the insulin secretion depending on blood glucose level. Recent studies show that the unsaturated fatty acids can promote GLP-1 secretion from intestinal L-cells. We have shown previously that docosahexaenoic acid (DHA) and eicosapentaenoic acid (EPA) administered into a mouse closed intestinal loop, especially into the colonic segment, stimulate GLP-1 and insulin secretion and have a hypoglycemic effect, suggesting that DHA and EPA have potential as antidiabetic agents. The present study examined the antidiabetic effect of DHA following long-term in vivo delivery to the colon using normal ddY and diabetic KK-A(y) mice. The plasma GLP-1 concentration of KK-A(y) mice increased after long-term DHA administration, and this had a significant hypoglycemic effect. In contrast, although GLP-1 secretion in ddY mice tended to increase after DHA administration, blood glucose concentration did not differ between vehicle- and DHA-treated ddY mice. Immunostaining of the pancreas after long-term DHA administration showed that continuous DHA treatment stimulated β-cell apoptosis and accordingly suppressed islet cell growth in KK-A(y) mice. Colon targeting of DHA may provide a new strategy for improving impaired glucose tolerance in type 2 diabetes mellitus by stimulating GLP-1 secretion, which may subsequently suppress the compensatory hyperplasia of pancreatic islets. Topics: Animals; Blood Glucose; Colon; Diabetes Mellitus, Type 2; Docosahexaenoic Acids; Glucagon-Like Peptide 1; Glucose Intolerance; Hyperplasia; Hypoglycemic Agents; Islets of Langerhans; Male; Mice; Mice, Transgenic | 2013 |
[Consumption of light soft drinks in children].
Topics: Adult; Body Mass Index; Body Weight; Carbonated Beverages; Child; Child, Preschool; Diabetes Mellitus, Type 2; Europe; France; Glucagon-Like Peptide 1; Humans; Maximum Allowable Concentration; Overweight; Risk Factors; Sweetening Agents; United States | 2013 |
Effects of 24-week treatment with acarbose on glucagon-like peptide 1 in newly diagnosed type 2 diabetic patients: a preliminary report.
Treatment with the alpha-glucosidase inhibitor (AGI) acarbose is associated with a significant reduction the risk of cardiovascular events. However, the underlying mechanisms of this effect are unclear. AGIs were recently suggested to participate in stimulating glucagon-like peptide 1 (GLP-1) secretion. We therefore examined the effects of a 24-week treatment of acarbose on endogenous GLP-1, nitric oxide (NO) levels, nitric oxide synthase (NOS) activity, and carotid intima-media thickness (CIMT) in newly diagnosed patients with type 2 diabetes (T2D).. Blood was drawn from 24 subjects (14 male, 10 female, age: 50.7 ± 7.36 years, BMI: 26.64 ± 3.38 kg/m2, GHbA1c: 7.00 ± 0.74%) with drug-naïve T2D at 0 and 120 min following a standard mixed meal for the measurements of active GLP-1, NO and NOS. The CIMT was measured prior to and following 24 weeks of acarbose monotherapy (mean dose: 268 mg daily).. Following 24 weeks of acarbose treatment, both fasting and postprandial plasma GLP-1 levels were increased. In patients with increased postprandial GLP-1 levels, serum NO levels and NOS activities were also significantly increased and were positively related to GLP-1 levels. Although the CIMT was not significantly altered following treatment with acarbose, a decreased CIMT was negatively correlated with increased GLP-1 levels.. Twenty-four weeks of acarbose monotherapy in newly diagnosed patients with T2D is associated with significantly increased levels of both fasting and postprandial GLP-1 as well as significantly increased NO levels and NOS activity for those patients in whom postprandial GLP-1 levels were increased. Therefore, the benefits of acarbose on cardiovascular risk may be related to its stimulation of GLP-1 secretion. Topics: Acarbose; Adult; Aged; Carotid Arteries; Carotid Intima-Media Thickness; Cohort Studies; Diabetes Mellitus, Type 2; Female; Glucagon-Like Peptide 1; Glycoside Hydrolase Inhibitors; Humans; Hypoglycemic Agents; Male; Middle Aged; Nitric Oxide; Nitric Oxide Synthase; Postprandial Period; Prospective Studies; Treatment Outcome | 2013 |
Retrospective real-world adherence in patients with type 2 diabetes initiating once-daily liraglutide 1.8 mg or twice-daily exenatide 10 μg.
The effectiveness of a drug is significantly influenced by a patient's adherence to the required regimen.. The goal of this retrospective database analysis was to determine the factors affecting adherence over a 12-month follow-up period in adults with type 2 diabetes mellitus (DM) initiating once-daily liraglutide (1.8 mg) or twice-daily exenatide (10 μg).. A patient-centric claims database was used, covering the period January 2009 to December 2011. Patients were included if they had ≥1 claim of once-daily liraglutide 1.8 mg or twice-daily exenatide 10 μg from January to December 2010 (index date [ID]), ≥2 diagnoses of type 2 DM before ID, continuous enrollment for 12 months before and after ID, and age ≥18 years at ID. Patients were required to be glucagon-like peptide-1 receptor agonist treatment-naive in the 12 months preceding ID and have a second prescription for once-daily liraglutide 1.8 mg or twice-daily exenatide 10 μg during the 12 months after ID. The medication possession ratio (MPR) was used as a continuous variable and to categorize patients as high-adherent (MPR ≥80%) or low-adherent (MPR <80%). Regression analyses were conducted to determine the predictors for nonadherence in the type 2 DM population, with bivariate testing of the MPR categories conducted initially to determine the predictors to be included in the final regression model.. A total of 3623 patients (once-daily liraglutide 1.8 mg, n = 2036; twice-daily exenatide 10 μg, n = 1587) were identified. Variables found to reduce adherence were younger age, female sex, Southern geographic region, twice-daily exenatide treatment, and higher percentage of copayment from the claimant. After adjusting for confounding factors, patients receiving once-daily liraglutide 1.8 mg were ∼11% more adherent than patients receiving twice-daily exenatide 10 μg (95% CI, 7-14; P < 0.0001). The odds ratio for "poor" adherence (MPR <80%) with twice-daily exenatide 10 μg therapy compared with liraglutide 1.8 mg once-daily was 1.33 (95% CI, 1.16-1.53; P < 0.0001).. This study found that adherence to once-daily liraglutide 1.8 mg treatment was superior to twice-daily exenatide 10 μg over a 12-month follow-up period. Nonadherence has important implications to the health care system, both in terms of clinical effectiveness and economic burden (eg, hospitalization, productivity losses). Using strategies to increase adherence is vital to reduce the future clinical and economic burden of diabetes. Topics: Adolescent; Adult; Aged; Diabetes Mellitus, Type 2; Drug Administration Schedule; Exenatide; Female; Glucagon-Like Peptide 1; Humans; Hypoglycemic Agents; Liraglutide; Male; Middle Aged; Patient Compliance; Peptides; Retrospective Studies; Venoms; Young Adult | 2013 |
Exaggerated glucagon-like peptide 1 response is important for improved β-cell function and glucose tolerance after Roux-en-Y gastric bypass in patients with type 2 diabetes.
β-Cell function improves in patients with type 2 diabetes in response to an oral glucose stimulus after Roux-en-Y gastric bypass (RYGB) surgery. This has been linked to the exaggerated secretion of glucagon-like peptide 1 (GLP-1), but causality has not been established. The aim of this study was to investigate the role of GLP-1 in improving β-cell function and glucose tolerance and regulating glucagon release after RYGB using exendin(9-39) (Ex-9), a GLP-1 receptor (GLP-1R)-specific antagonist. Nine patients with type 2 diabetes were examined before and 1 week and 3 months after surgery. Each visit consisted of two experimental days, allowing a meal test with randomized infusion of saline or Ex-9. After RYGB, glucose tolerance improved, β-cell glucose sensitivity (β-GS) doubled, the GLP-1 response greatly increased, and glucagon secretion was augmented. GLP-1R blockade did not affect β-cell function or meal-induced glucagon release before the operation but did impair glucose tolerance. After RYGB, β-GS decreased to preoperative levels, glucagon secretion increased, and glucose tolerance was impaired by Ex-9 infusion. Thus, the exaggerated effect of GLP-1 after RYGB is of major importance for the improvement in β-cell function, control of glucagon release, and glucose tolerance in patients with type 2 diabetes. Topics: Blood Glucose; Diabetes Mellitus, Type 2; Fasting; Female; Gastric Bypass; Gastric Emptying; Gastric Inhibitory Polypeptide; Glucagon; Glucagon-Like Peptide 1; Glucagon-Like Peptide-1 Receptor; Humans; Insulin Resistance; Insulin-Secreting Cells; Male; Middle Aged; Peptide Fragments; Receptors, Glucagon | 2013 |
Influence of hemodialysis on incretin hormones and insulin secretion in diabetic and non-diabetic patients.
Incretin hormones are secreted in the gut after a meal and stimulate insulin production. Both major incretins, that is, glucagon-like peptide-1 (GLP-1) and glucose-dependent insulinotropic polypeptide (GIP), are eliminated by the kidneys. Little is known about the influence of end-stage renal disease (ESRD) on the incretin axis. The aim of the study was to assess the effect of the commencement of chronic hemodialysis (HD) therapy on serum GLP-1 and GIP, and insulin sensitivity in diabetic and non-diabetic patients.. The study comprised 56 patients (23 F, 33 M; mean age 57 ± 14 years) with ESRD in the course of diabetic nephropathy (n = 23) and non-diabetic renal diseases (n = 34) who started chronic HD. Glucose metabolism, including incretin hormones concentration, was assessed before the first HD session and repeated after the first 6 months of the therapy.. After 6 months of HD, a significant increase in fasting GLP-1 concentration was observed in both diabetic and non-diabetic patients [by 2.27 pmol/l (45 %) and 1.28 pmol/l (22 %), respectively, p = 0.0003]. Serum GIP increased significantly only in diabetic patients [by 30.9 pg/ml (55 %); p = 0.008]. No significant change of fasting glucose was found but HOMA-IR and serum insulin decreased significantly in diabetic patients (p = 0.01 and p = 0.008, respectively). In contrast, HOMA-B was unchanged in both groups. Changes of HOMA-IR did not significantly correlate with serum GLP-1 or GIP concentrations.. Our results indicate that starting the hemodialysis therapy helps to restore the incretin axis in particular in patients with the diabetic kidney disease. Topics: Adult; Aged; Blood Glucose; Case-Control Studies; Diabetes Mellitus, Type 2; Diabetic Nephropathies; Fasting; Female; Gastric Inhibitory Polypeptide; Glucagon-Like Peptide 1; Homeostasis; Humans; Insulin; Insulin Resistance; Insulin Secretion; Kidney Failure, Chronic; Male; Middle Aged; Renal Dialysis; Time Factors | 2013 |
The GLP-1 receptor agonist liraglutide inhibits progression of vascular disease via effects on atherogenesis, plaque stability and endothelial function in an ApoE(-/-) mouse model.
Liraglutide, a once-daily glucagon-like peptide-1 receptor (GLP-1R) agonist, has been approved as a new treatment for type 2 diabetes and is the subject of a clinical trial programme to evaluate the effects on cardiovascular disease and safety. The current study aimed to determine the in vivo effect of liraglutide on progression of atherosclerotic vascular disease in the apolipoprotein E-deficient (ApoE(-/-)) mouse model and identify underlying mechanisms responsible. Liraglutide treatment inhibited progression of early onset, low-burden atherosclerotic disease in a partially GLP-1R-dependent manner in the ApoE(-/-) mouse model. In addition, liraglutide treatment inhibited progression of atherosclerotic plaque formation and enhanced plaque stability, again in a partially GLP-1R-dependent manner. No significant effect of liraglutide on progression of late onset, high-burden atherosclerotic disease was observed. In addition, no significant endothelial cell dysfunction was identified in ApoE(-/-) mice with early onset, low-burden atherosclerotic disease, although significant prevention of weight gain was observed in liraglutide-treated mice using this dietary protocol. Taken together, these results suggest a potential role for liraglutide in the prevention and stabilisation of atherosclerotic vascular disease together with possible protection against major cardiovascular events. Topics: Animals; Apolipoproteins E; Atherosclerosis; Diabetes Mellitus, Type 2; Disease Models, Animal; Disease Progression; Endothelial Cells; Glucagon-Like Peptide 1; Glucagon-Like Peptide-1 Receptor; Hypoglycemic Agents; Liraglutide; Mice; Mice, Inbred C57BL; Mice, Knockout; Plaque, Atherosclerotic; Receptors, Glucagon | 2013 |
Duodenal-jejunal bypass surgery up-regulates the expression of the hepatic insulin signaling proteins and the key regulatory enzymes of intestinal gluconeogenesis in diabetic Goto-Kakizaki rats.
Duodenal-jejunal bypass (DJB), which is not routinely applied in metabolic surgery, is an effective surgical procedure in terms of type 2 diabetes mellitus resolution. However, the underlying mechanisms are still undefined. Our aim was to investigate the diabetic improvement by DJB and to explore the changes in hepatic insulin signaling proteins and regulatory enzymes of gluconeogenesis after DJB in a non-obese diabetic rat model.. Sixteen adult male Goto-Kakizaki rats were randomly divided into DJB and sham-operated groups. The body weight, food intake, hormone levels, and glucose metabolism were measured. The levels of protein expression and phosphorylation of insulin receptor-beta (IR-β) and insulin receptor substrate 2 (IRS-2) were evaluated in the liver. We also detected the expression of key regulatory enzymes of gluconeogenesis [phosphoenoylpyruvate carboxykinase-1 (PCK1), glucose-6-phosphatase-alpha (G6Pase-α)] in small intestine and liver.. DJB induced significant diabetic improvement with higher postprandial glucagons-like peptide 1, peptide YY, and insulin levels, but without weight loss. The DJB group exhibited increased expression and phosphorylation of IR-β and IRS-2 in liver, up-regulated the expression of PCK1 and G6Pase-α in small intestine, and down-regulated the expression of these enzymes in liver.. DJB is effective in up-regulating the expression of the key proteins in the hepatic insulin signaling pathway and the key regulatory enzymes of intestinal gluconeogenesis and down-regulating the expression of the key regulatory enzymes of hepatic gluconeogenesis without weight loss. Our study helps to reveal the potential role of hepatic insulin signaling pathway and intestinal gluconeogenesis in ameliorating insulin resistance after metabolic surgery. Topics: Animals; Biological Transport; Blood Glucose; Diabetes Mellitus, Experimental; Diabetes Mellitus, Type 2; Down-Regulation; Duodenum; Gastric Bypass; Glucagon-Like Peptide 1; Gluconeogenesis; Glucose-6-Phosphatase; Incretins; Insulin; Insulin Receptor Substrate Proteins; Insulin Resistance; Intracellular Signaling Peptides and Proteins; Jejunum; Liver; Male; Phosphoenolpyruvate Carboxykinase (GTP); Rats; Rats, Inbred Strains; Remission Induction; Signal Transduction; Up-Regulation; Weight Loss | 2013 |
Sustained weight loss after treatment with a glucagon-like peptide-1 receptor agonist in an obese patient with schizophrenia and type 2 diabetes.
Topics: Antipsychotic Agents; Clozapine; Diabetes Mellitus, Type 2; Female; Glucagon-Like Peptide 1; Glucagon-Like Peptide-1 Receptor; Glycated Hemoglobin; Humans; Liraglutide; Middle Aged; Obesity; Receptors, Glucagon; Schizophrenia; Weight Loss | 2013 |
Postprandial adiponectin levels are associated with improvements in postprandial triglycerides after Roux-en-Y gastric bypass in type 2 diabetic patients.
Postprandial hypertrygliceridemia is a known factor for cardiovascular disease and is often observed in patients with type 2 diabetes mellitus (T2DM) and visceral adiposity. Adiponectin is a hormone with antiatherogenic and anti-inflammatory effects, which decreases in obesity and T2DM subjects. The weight loss induced by diet or bariatric surgery could be restoring adiponectin levels.. The aim of the study was to evaluate the impact of weight loss induced by bariatric surgery, which could restore adiponectin and triglycerides (TG) levels in obese and diabetic patients.. Ten patients with T2DM (BMI 39.3+2.44) were evaluated before and at 7 and 90 days after Roux-en-Y gastric bypass (RYGB). A meal test was performed and plasma insulin, glucagon-like peptide-1 (GLP-1), glucose, TG, and adiponectin levels were measured at fasting and at 30, 60, 90, and 120 min postprandial.. Seven days after surgery, significant reductions in the insulin resistance were observed, while TG and adiponectin levels remained unchanged during the meal test. Ninety days after surgery, TG and glucose levels decreased significantly at fasting, and postprandial, adiponectin, GLP-1, and insulin curves increased significantly after meal ingestion. Both changes in the area under the curve (AUC) of adiponectin correlated with changes in the AUC of TG (R=-0.64, P=0.003) and changes in AUC of adiponectin correlated with changes in total fat mass. No correlation was found between changes in insulin, GLP-1, and TG levels.. The adiponectin levels may be involved in the mechanism responsible for high TG levels in obese and diabetic patients. These abnormalities can be reversed by RYGB. Topics: Adiponectin; Adult; Aged; Anastomosis, Roux-en-Y; Area Under Curve; Blood Glucose; Body Mass Index; Cholesterol; Cholesterol, HDL; Diabetes Mellitus, Type 2; Fasting; Female; Glucagon-Like Peptide 1; Humans; Insulin; Male; Middle Aged; Postprandial Period; Treatment Outcome; Triglycerides; Young Adult | 2013 |
Peptidomic profiling of secreted products from pancreatic islet culture results in a higher yield of full-length peptide hormones than found using cell lysis procedures.
Peptide Hormone Acquisition through Smart Sampling Technique-Mass Spectrometry (PHASST-MS) is a peptidomics platform that employs high resolution liquid chromatography-mass spectrometry (LC-MS) techniques to identify peptide hormones secreted from in vitro or ex vivo cultures enriched in endocrine cells. Application of the methodology to the study of murine pancreatic islets has permitted evaluation of the strengths and weaknesses of the approach, as well as comparison of our results with published islet studies that employed traditional cellular lysis procedures. We found that, while our PHASST-MS approach identified fewer peptides in total, we had greater representation of intact peptide hormones. The technique was further refined to improve coverage of hydrophilic as well as hydrophobic peptides and subsequently applied to human pancreatic islet cultures derived from normal donors or donors with type 2 diabetes. Interestingly, in addition to the expected islet hormones, we identified alpha-cell-derived bioactive GLP-1, consistent with recent reports of paracrine effects of this hormone on beta-cell function. We also identified many novel peptides derived from neurohormonal precursors and proteins related to the cell secretory system. Taken together, these results suggest the PHASST-MS strategy of focusing on cellular secreted products rather than the total tissue peptidome may improve the probability of discovering novel bioactive peptides and also has the potential to offer important new insights into the secretion and function of known hormones. Topics: Amino Acid Motifs; Animals; Chromatography, Liquid; Diabetes Mellitus, Type 2; Glucagon-Like Peptide 1; Humans; Islets of Langerhans; Mass Spectrometry; Mice; Molecular Sequence Annotation; Molecular Sequence Data; Peptide Fragments; Peptide Hormones; Proteomics; Tissue Culture Techniques | 2013 |
Effect of sleeve gastrectomy on body weight, food intake, glucose tolerance, and metabolic hormone level in two different rat models: Goto-Kakizaki and diet-induced obese rat.
It is still an important question whether sleeve gastrectomy (SG) is appropriate only in the context of obesity-the condition for which it was originally developed-or whether lean people with insulin-deficient diabetes might also benefit. The aim of this study is to evaluate the effects of SG in Goto-Kakizaki (GK) and diet-induced obese (DIO) rats that have distinct characteristics in beta-cell function and fat mass.. SG was performed in GK and DIO rats. Body weight, food intake, and fasting blood glucose were monitored after surgery. Des-acyl ghrelin in fasting condition and blood glucose, insulin, and glucagon-like peptide-1 levels during meal test were measured. Homeostatic model assessment and insulinogenic index were examined.. In both GK and DIO rats, SG improved glucose tolerance with increased glucagon-like peptide-1 and insulin secretion during meal test, and reduced fasting des-acyl ghrelin levels. Insulin sensitivity was enhanced after SG in DIO rats. The improvement in glucose tolerance after SG was shown earlier in DIO rats than in GK rats and weight regain after SG occurred faster and was more prominent in GK rats than in DIO rats.. In both DIO and GK rats, SG could improve glucose tolerance with increased insulin secretion and/or action. The improvement in glucose tolerance was shown earlier in DIO rats than in GK rats. Topics: Animals; Blood Glucose; Body Weight; Diabetes Mellitus, Experimental; Diabetes Mellitus, Type 2; Diet, High-Fat; Disease Models, Animal; Eating; Gastrectomy; Ghrelin; Glucagon-Like Peptide 1; Glucose Intolerance; Glucose Tolerance Test; Hormones; Insulin; Male; Obesity; Rats; Rats, Mutant Strains; Rats, Wistar | 2013 |
Do current incretin mimetics exploit the full therapeutic potential inherent in GLP-1 receptor stimulation?
Glucagon-like peptide-1 (GLP-1) receptor agonists (RAs) are incretin-derived glucose-lowering agents that have been used for the treatment of type 2 diabetes since 2007. Agents such as exenatide (short-acting and once weekly preparations), liraglutide, taspoglutide, albiglutide and lixisenatide lower fasting glucose and HbA1c upon subcutaneous injection, leading to glycaemic control that is equivalent to, or better than, that observed with other oral glucose-lowering agents or bedtime insulin. However, varying proportions of patients report nausea and vomiting, adverse events that typically narrow the therapeutic dose range. Furthermore, GLP-1 RAs reduce fasting glucose to a clinically meaningful extent, but not into the normal range. In contrast, where GLP-1 is administered as a short-term intravenous infusion, a full normalisation of glucose concentrations (approximately 5 mmol/l) has been observed without any risk of gastrointestinal side effects. Subcutaneous infusions or injections of GLP-1 are much less effective. The present analysis relates the proportion of patients who report nausea following treatment with GLP-1 and GLP-1 RAs to the clinical effectiveness of the treatment (represented by the fasting glucose concentration achieved with treatment). The results suggest that GLP-1 RAs injected into the subcutaneous compartment do not exploit the full potential inherent in GLP-1 receptor activation. Reasons for this may include modifications of the peptide molecules in the subcutaneous environment or high local concentrations triggering side effects through GLP-1 receptors on autonomic nerves in subcutaneous adipose tissue. Elucidation of the mechanisms underlying differential responses to GLP-1/GLP-1 RAs administered intravenously vs subcutaneously may help to develop improved agents or modes of administration that are more effective and have fewer side effects. Topics: Diabetes Mellitus, Type 2; Exenatide; Glucagon-Like Peptide 1; Glucagon-Like Peptide-1 Receptor; Humans; Incretins; Liraglutide; Peptides; Receptors, Glucagon; Venoms | 2013 |
Helping patients make sense of the risks of taking GLP-1 agonists.
Topics: Asymptomatic Diseases; Diabetes Complications; Diabetes Mellitus, Type 2; Glucagon-Like Peptide 1; Humans; Hyperglycemia; Hypoglycemic Agents; Incretins; Insulin-Secreting Cells; Outcome Assessment, Health Care; Risk Assessment | 2013 |
The effects of dipeptidyl-peptidase-IV inhibitor, vildagliptin, on the exocrine pancreas in spontaneously diabetic Goto-Kakizaki rats.
The risk of adverse effects of dipeptidyl peptidase-4 inhibitors on the exocrine pancreas, particularly the high risk of pancreatitis, is controversial. In this study, we examined the exocrine pancreatic function and structure in spontaneously diabetic Goto-Kakizaki (GK) rats treated with a dipeptidyl peptidase-4 inhibitor.. Male GK rats and normal Wistar rats 4 weeks of age were treated with vildagliptin (VG; 30 mg/kg/d) for 18 weeks. Subsequently, exocrine pancreatic pathology and function in treated animals were compared to those in untreated animals.. In GK rats, VG treatment suppressed elevated serum concentrations of amylase and lipase, reduced lymphocytic infiltration around ducts, around vessels, and in acinar areas, and reduced the frequency of apoptotic acinar cells and ductule formation (both of which occurred more frequently in GK rats than Wistar rats). However, VG treatment had no effect on the proliferation rate of pancreatic duct glandular cells (which was low in GK rats) and of cells in the main ducts, peripheral ducts, and acini (which was similar in all groups).. Perturbations of exocrine pancreatic function and structure in GK rats are ameliorated by long-term VG treatment. Topics: Acinar Cells; Adamantane; Animals; Apoptosis; Blood Glucose; Cell Proliferation; Diabetes Mellitus, Type 2; Dipeptidyl-Peptidase IV Inhibitors; Fasting; Glucagon-Like Peptide 1; Immunohistochemistry; Insulin; Ki-67 Antigen; Male; Nitriles; Pancreas, Exocrine; Pancreatic Ducts; Pyrrolidines; Rats; Rats, Wistar; Species Specificity; Vildagliptin | 2013 |
Dipeptidyl peptidase-4 inhibitor anagliptin ameliorates diabetes in mice with haploinsufficiency of glucokinase on a high-fat diet.
Type 2 diabetes is a chronic metabolic disorder characterized by hyperglycemia with insulin resistance and impaired insulin secretion. DPP-4 inhibitors have attracted attention as a new class of anti-diabetic agents for the treatment of type 2 diabetes. We investigated the effects of anagliptin, a highly selective DPP-4 inhibitor, on insulin secretion and insulin resistance in high-fat diet-fed mice with haploinsufficiency of glucokinase (GckKO) as animal models of type 2 diabetes.. Wild-type and GckKO mice were administered two doses of anagliptin by dietary admixture (0.05% and 0.3%) for 10weeks.. Both doses of anagliptin significantly inhibited the plasma DPP-4 activity and increased the plasma active GLP-1 levels in both the wild-type and GckKO mice to a similar degree. After 10weeks of treatment with 0.3% anagliptin, body weight gain and food intake were significantly suppressed in both wild-type and GckKO mice. In addition, 0.3% anagliptin ameliorated insulin resistance and glucose intolerance in both genotypes of mice. On the other hand, treatment with 0.05% anagliptin was not associated with any significant change of the body weight, food intake or insulin sensitivity in either genotype of mice, but it did improve the glucose tolerance by enhancing insulin secretion and increasing the β-cell mass in both genotypes of mice.. High-dose anagliptin treatment improved glucose tolerance by suppression of body weight gain and amelioration of insulin resistance, whereas low-dose anagliptin treatment improved glucose tolerance by enhancing insulin secretion. Topics: Animals; Diabetes Mellitus, Type 2; Diet, High-Fat; Dipeptidyl Peptidase 4; Dipeptidyl-Peptidase IV Inhibitors; Dose-Response Relationship, Drug; Energy Intake; Glucagon-Like Peptide 1; Glucokinase; Glucose Intolerance; Haploinsufficiency; Insulin; Insulin Resistance; Insulin Secretion; Insulin-Secreting Cells; Male; Mice; Mice, Inbred C57BL; Mice, Knockout; Obesity; Pyrimidines; Weight Gain | 2013 |
Oral administration of corn zein hydrolysate stimulates GLP-1 and GIP secretion and improves glucose tolerance in male normal rats and Goto-Kakizaki rats.
We have previously demonstrated that ileal administration of the dietary protein hydrolysate prepared from corn zein (ZeinH) stimulated glucagon-like peptide-1 (GLP-1) secretion and attenuated hyperglycemia in rats. In this study, to examine whether oral administration of ZeinH improves glucose tolerance by stimulating GLP-1 and glucose-dependent insulinotropic polypeptide (GIP) secretion, glucose tolerance tests were performed in normal Sprague-Dawley male rats and diabetic Goto-Kakizaki (GK) male rats. The test solution was gavaged before ip glucose injection in normal rats or gavaged together with glucose in GK rats. Blood samples were collected from the tail vein or by using the jugular catheter to measure glucose, insulin, GLP-1, and GIP levels. In the ip glucose tolerance test, oral administration of ZeinH (2 g/kg) significantly suppressed the glycemic response accompanied by an immediate increase in plasma GLP-1 and GIP levels in normal rats. In contrast, oral administration of another dietary peptide, meat hydrolysate, did not elicit a similar effect. The glucose-lowering effect of ZeinH was attenuated by a GLP-1 receptor antagonist or by a GIP receptor antagonist. Furthermore, oral ZeinH induced GLP-1 secretion and reduced glycemic response in GK rats under the oral glucose tolerance test. These results indicate that the oral administration of the dietary peptide ZeinH improves glucose tolerance in normal and diabetic rats by its incretin-releasing activity, namely, the incretinotropic effect. Topics: Animals; Cell Line; Diabetes Mellitus, Type 2; Dietary Supplements; Digestion; Enterocytes; Gastric Inhibitory Polypeptide; Glucagon-Like Peptide 1; Glucagon-Like Peptide-1 Receptor; Glucose Tolerance Test; Hypoglycemic Agents; Male; Mice; Protein Hydrolysates; Rats; Rats, Inbred Strains; Rats, Sprague-Dawley; Receptors, Gastrointestinal Hormone; Receptors, Glucagon; Up-Regulation; Zein | 2013 |
Integrating incretin-based therapy into type 2 diabetes management.
Topics: Biomarkers; Clinical Trials as Topic; Diabetes Mellitus, Type 2; Dipeptidyl-Peptidase IV Inhibitors; Drug Administration Schedule; Exenatide; Glucagon-Like Peptide 1; Glucagon-Like Peptide-1 Receptor; Humans; Hypoglycemic Agents; Incretins; Liraglutide; Medication Adherence; Peptides; Practice Guidelines as Topic; Receptors, Glucagon; Venoms | 2013 |
Novo Nordisk replies to BMJ investigation on incretins and pancreatic damage.
Topics: Acute Disease; Diabetes Mellitus, Type 2; Glucagon-Like Peptide 1; Humans; Hypoglycemic Agents; Incretins; Liraglutide; Pancreas; Pancreatitis | 2013 |
In vitro protein binding of liraglutide in human plasma determined by reiterated stepwise equilibrium dialysis.
Liraglutide is a human glucagon-like peptide-1 (GLP-1) analogue approved for the treatment of type 2 diabetes. It is based on human GLP-1 with the addition of a 16-carbon fatty acid, which facilitates binding to plasma proteins, thus prolonging the elimination half-life and allowing once-daily administration. It has not been possible to quantify liraglutide protein binding by ultrafiltration (the usual method of choice), as the lipophilic molecule becomes trapped in the filter membrane. Therefore, the aim of this study was to develop a methodology that could determine the extent of liraglutide binding to plasma proteins in vitro. We report here the details of a novel reiterated stepwise equilibrium dialysis assay that has successfully been used to quantify liraglutide plasma protein binding. The assay allowed quantification of liraglutide binding to proteins in purified plasma protein solutions and human plasma samples and was effective at plasma dilutions as low as 5%. At a clinically relevant liraglutide concentration (10(4) pM), greater than 98.9% of liraglutide was bound to protein. Specific binding to human serum albumin and α1-acid glycoprotein was 99.4% and 99.3%, respectively. The novel methodology described herein could have an application in the quantification of plasma protein binding of other highly lipophilic drug molecules. Topics: Blood Proteins; Diabetes Mellitus, Type 2; Dialysis; Equipment Design; Glucagon-Like Peptide 1; Humans; Hypoglycemic Agents; Liraglutide; Protein Binding | 2013 |
Preserved GLP-1 and exaggerated GIP secretion in type 2 diabetes and relationships with triglycerides and ALT.
To i) compare incretin responses to oral glucose and mixed meal of diabetic patients with the normoglycaemic population and ii) to investigate whether incretin responses are associated with hypertriglyceridaemia and alanine aminotransferase (ALT) as liver fat marker.. A population-based study.. A total of 163 persons with normal glucose metabolism (NGM), 20 with intermediate hyperglycaemia and 20 with type 2 diabetes aged 40-65 years participated. Participants received a mixed meal and oral glucose load on separate occasions. Glucagon-like peptide 1 (GLP-1), glucose-dependent insulinotropic polypeptide (GIP) and glucagon profiles were analysed as total area under the curve (tAUC) and incremental area under the curve.. In diabetic patients compared with persons with NGM, we found increased GLP-1 secretion (tAUC per hour) following oral glucose (23.2 pmol/l (95% CI 17.7-28.7) vs 18.0 (95% CI 16.9-19.1), P<0.05) but not after the mixed meal. GIP secretion among diabetic patients was increased on both occasions (82.9 pmol/l (55.9-109.8) vs 47.1 (43.8-50.4) for oral glucose and 130.6 (92.5-168.7) vs 83.2 (77.5-88.9) for mixed meal, both P<0.05). After oral glucose, GLP-1 (tAUC per hour) was inversely related to fasting triglycerides. GIP (tAUC per hour) was positively related to fasting and postprandial triglycerides. Higher fasting GIP levels were related to higher fasting and postprandial triglyceride levels and ALT.. This study confirms that in type 2 diabetes, GLP-1 secretion is generally preserved and that GIP secretion is exaggerated. The mechanism underlying the divergent associations of GLP-1 and GIP metabolism with fat metabolism and liver fat accumulation warrants further study. Topics: Adult; Aged; Alanine Transaminase; Area Under Curve; Biomarkers; Diabetes Mellitus, Type 2; Eating; Female; Gastric Inhibitory Polypeptide; Glucagon; Glucagon-Like Peptide 1; Glucose; Glucose Tolerance Test; Humans; Incretins; Lipid Metabolism; Male; Middle Aged; Triglycerides | 2013 |
Effects on glucagon-like peptide-1 secretion by distal ileal administration of nutrients.
The aim of this study was to investigate the effects of nutrients (glucose, fat, and amino acid) on glucagon-like peptide-1 (GLP-1) secretion by the L cell in the distal ileum and insulin level in peripheral blood.. Ninety-six Wistar rats were randomly allocated into 12 groups, with 8 rats in each group: glucose-10 cm, glucose-15 cm, glucose-20 cm, fat-10 cm, fat-15 cm, fat-20 cm, amino acid-10 cm, amino acid-15 cm, amino acid-20 cm, control-10 cm, control-15 cm, and control-20 cm. Blood samples were collected at 0, 30, 60, 90, and 120 min after in vivo distal ileal perfusion of nutrients or normal saline (control groups). Blood glucose level was assessed by a handheld glucometer. Plasma GLP-1 and insulin level were evaluated by ELISA. GLP-1 level was also evaluated by immunohistochemistry analysis of GLP-1 expression in ileal mucosa and scanning electron microscope analysis of ultrastructural changes of L cells.. Under administration of nutrients in the distal ileum of equal length, GLP-1 levels were greatest for fat, then glucose, and then amino acid (the peak concentration of GLP-1 in the fat-10 cm group, the glucose-10 cm group, the amino acid-10 cm group, and the control-10 cm group was 29.76 ± 1.32, 28.54 ± 1.29, 26.30 ± 1.26, and 22.52 ± 1.22 pmol/L, respectively, with p < 0.05). Under administration of nutrients in the distal ileum of equal length, insulin levels were also greatest for fat, then glucose, and then amino acid (the peak concentration of insulin in the fat-10 cm group, the glucose-10 cm group, the amino acid-10 cm group, and the control-10 cm group was 30.10 ± 1.33, 27.17 ± 1.27, 22.98 ± 1.31, and 12.40 ± 1.11 mU/L, respectively, with p < 0.05). Under administration of the same nutrients, the longer the distal ileum was stimulated, the greater the GLP-1 and insulin levels.. Long distal ileal administration of fat more efficiently stimulated GLP-1 secretion, resulting in enhanced insulin secretion. Topics: Animals; Diabetes Mellitus, Experimental; Diabetes Mellitus, Type 2; Dietary Fats; Enzyme-Linked Immunosorbent Assay; Gastric Bypass; Glucagon-Like Peptide 1; Glucose; Ileum; Injections, Intraperitoneal; Insulin; Insulin Secretion; Intestinal Mucosa; L Cells; Male; Mice; Peptide Fragments; Rats; Rats, Wistar | 2013 |
Liraglutide ameliorates glycometabolism and insulin resistance through the upregulation of GLUT4 in diabetic KKAy mice.
Liraglutide, a long-lasting glucagon‑like peptide‑1 analogue, has been used for the treatment of patients with type 2 diabetes mellitus since 2009. In this study, we investigated the anti-diabetic effects and mechanisms of action of liraglutide in a spontaneous diabetic animal model, using KK/Upj-Ay/J (KKAy) mice. The KKAy mice were divided into 2 groups, the liraglutide group (mice were treated with 250 µg/kg/day liraglutide) and the model group (treated with an equivalent amount of normal saline). C57BL/6J mice were used as the controls (treated with an equivalent amount of normal saline). The treatment period lasted 6 weeks. During this treatment period, fasting blood glucose (FBG) levels and the body weight of the mice were measured on a weekly basis. Our results revealed that liraglutide significantly decreased FBG levels, the area under the curve following a oral glucose tolerance test and insulin tolerance test, increased serum insulin levels, reduced homeostasis model assessment of insulin resistance and increased the insulin sensitivity index. Furthermore, liraglutide ameliorated glycometabolism dysfunction by increasing glycolysis via hexokinase and glycogenesis via pyruvate kinase activation. An ultrastructural examination of the pancreas revealed that liraglutide improved the damaged state of islet β cells and increased the number of insulin secretory granules. The real-time PCR results revealed that the gene expression of glucose transporter 4 (GLUT4) increased following treatment with liraglutide. Liraglutide also upregulated the protein expression of GLUT4 in liver tissue and skeletal muscle. Our results suggest that liraglutide ameliorates glycometabolism and insulin resistance in diabetic KKAy mice by stimulating insulin secretion, increasing glycogenesis and glycolysis and upregulating the expression of GLUT4. Topics: Animals; Blood Glucose; Body Weight; Diabetes Mellitus, Type 2; Disease Models, Animal; Glucagon-Like Peptide 1; Glucose Tolerance Test; Glucose Transporter Type 4; Glycolysis; Hypoglycemic Agents; Immunohistochemistry; Insulin; Insulin Resistance; Liraglutide; Liver; Male; Mice; Mice, Inbred C57BL; Microscopy, Electron, Transmission; Muscle, Skeletal; Real-Time Polymerase Chain Reaction; Up-Regulation | 2013 |
DNA methylation of the glucagon-like peptide 1 receptor (GLP1R) in human pancreatic islets.
Insulin secretion is enhanced upon the binding of Glucagon-like peptide-1 (GLP-1) to its receptor (GLP1R) in pancreatic β cells. Although a reduced expression of GLP1R in pancreatic islets from type 2 diabetic patients and hyperglycaemic rats has been established, it is still unknown if this is caused by differential DNA methylation of GLP1R in pancreatic islets of type 2 diabetic patients.. In this study, DNA methylation levels of 12 CpG sites close to the transcription start site of GLP1R were analysed in pancreatic islets from 55 non-diabetic and 10 type 2 diabetic human donors as well as in β and α cells isolated from human pancreatic islets. DNA methylation of GLP1R was related to GLP1R expression, HbA1c levels and BMI. Moreover, mRNA expression of MECP2, DNMT1, DNMT3A and DNMT3B was analysed in pancreatic islets of the non-diabetic and type 2 diabetic donors.. One CpG unit, at position +199 and +205 bp from the transcription start site, showed a small increase in DNA methylation in islets from donors with type 2 diabetes compared to non-diabetic donors (0.53%, p=0.02). Furthermore, DNA methylation levels of one CpG site located 376 bp upstream of the transcription start site of GLP1R correlated negatively with GLP1R expression (rho=-0.34, p=0.008) but positively with BMI and HbA1c (rho=0.30, p=0.02 and rho=0.30, p=0.03, respectively). This specific CpG site is located in an area with known SP1 and SP3 transcription factor binding sites. Moreover, when we compared the DNA methylation of the GLP1R promoter in isolated human β and α cells, we found that it was higher in α- compared with β-cells (p=0.009). Finally, there was a trend towards decreased DNMT3A expression (p=0.056) in type 2 diabetic compared with non-diabetic islets.. Together, our study shows that while BMI and HbA1c are positively associated with DNA methylation levels of GLP1R, its expression is negatively associated with DNA methylation of GLP1R in human pancreatic islets. Topics: Aged; Body Mass Index; CpG Islands; Diabetes Mellitus, Type 2; DNA (Cytosine-5-)-Methyltransferase 1; DNA (Cytosine-5-)-Methyltransferases; DNA Methylation; DNA Methyltransferase 3A; DNA Methyltransferase 3B; Female; Glucagon-Like Peptide 1; Glucagon-Like Peptide-1 Receptor; Glucagon-Secreting Cells; Glycated Hemoglobin; Humans; Insulin; Insulin Secretion; Insulin-Secreting Cells; Islets of Langerhans; Male; Methyl-CpG-Binding Protein 2; Middle Aged; Receptors, Glucagon; Transcription Initiation Site | 2013 |
Pathophysiologic approach to therapy in patients with newly diagnosed type 2 diabetes.
Topics: Algorithms; Diabetes Mellitus, Type 2; Drug Therapy, Combination; Glucagon-Like Peptide 1; Humans; Hypoglycemic Agents; Insulin; Insulin Resistance; Insulin-Secreting Cells; Liver; Metformin; Muscles | 2013 |
Resveratrol prevents β-cell dedifferentiation in nonhuman primates given a high-fat/high-sugar diet.
Eating a "Westernized" diet high in fat and sugar leads to weight gain and numerous health problems, including the development of type 2 diabetes mellitus (T2DM). Rodent studies have shown that resveratrol supplementation reduces blood glucose levels, preserves β-cells in islets of Langerhans, and improves insulin action. Although rodent models are helpful for understanding β-cell biology and certain aspects of T2DM pathology, they fail to reproduce the complexity of the human disease as well as that of nonhuman primates. Rhesus monkeys were fed a standard diet (SD), or a high-fat/high-sugar diet in combination with either placebo (HFS) or resveratrol (HFS+Resv) for 24 months, and pancreata were examined before overt dysglycemia occurred. Increased glucose-stimulated insulin secretion and insulin resistance occurred in both HFS and HFS+Resv diets compared with SD. Although islet size was unaffected, there was a significant decrease in β-cells and an increase in α-cells containing glucagon and glucagon-like peptide 1 with HFS diets. Islets from HFS+Resv monkeys were morphologically similar to SD. HFS diets also resulted in decreased expression of essential β-cell transcription factors forkhead box O1 (FOXO1), NKX6-1, NKX2-2, and PDX1, which did not occur with resveratrol supplementation. Similar changes were observed in human islets where the effects of resveratrol were mediated through Sirtuin 1. These findings have implications for the management of humans with insulin resistance, prediabetes, and diabetes. Topics: Animals; Blood Glucose; Body Weight; Cell Dedifferentiation; Densitometry; Diabetes Mellitus, Experimental; Diabetes Mellitus, Type 2; Diet, High-Fat; Dietary Sucrose; Disease Models, Animal; Fluorescent Antibody Technique; Glucagon; Glucagon-Like Peptide 1; Glucagon-Secreting Cells; Glucose Tolerance Test; Glycated Hemoglobin; Homeobox Protein Nkx-2.2; Homeodomain Proteins; Insulin; Insulin Resistance; Insulin-Secreting Cells; Islets of Langerhans; Macaca mulatta; Nuclear Proteins; Protective Agents; Resveratrol; Sirtuin 1; Stilbenes; Transcription Factors | 2013 |
Long-term liraglutide treatment is associated with increased insulin content and secretion in β-cells, and a loss of α-cells in ZDF rats.
The ultimate treatment goal of diabetes is to preserve and restore islet cell function. Treatment of certain diabetic animal models with incretins has been reported to preserve and possibly enhance islet function and promote islet cell growth. The studies reported here detail islet cell anatomy in animals chronically treated with the incretin analog, liraglutide. Our aim was to quantitatively and qualitatively analyze islet cells from diabetic animals treated with vehicle (control) or liraglutide to determine whether normal islet cell anatomy is maintained or enhanced with pharmaceutical treatment. We harvested pancreata from liraglutide and vehicle-treated Zucker Diabetic Fatty (ZDF) rats to examine islet structure and function and obtain isolated islets. Twelve-week-old male rats were assigned to 3 groups: (1) liraglutide-treated diabetic, (2) vehicle-treated diabetic, and (3) lean non-diabetic. Liraglutide was given SC twice daily for 9 weeks. As expected, liraglutide treatment reduced body weight by 15% compared to the vehicle-treated animals, eventually to levels that were not different from lean controls. At the termination of the study, blood glucose was significantly less in the liraglutide-treated rats compared to vehicle treated controls (485.8±22.5 and 547.2±33.1mg/dl, respectively). Insulin content/islet (measured by immunohistochemistry) was 34.2±0.7 pixel units in vehicle-treated rats, and 54.9±0.6 in the liraglutide-treated animals. Glucose-stimulated insulin secretion from isolated islets (measured as the stimulation index) was maintained in the liraglutide-treated rats, but not in the vehicle-treated. However, liraglutide did not preserve normal islet architecture. There was a decrease in the glucagon-positive area/islet and in the α-cell numbers/area with liraglutide treatment (6.5 cells/field), compared to vehicle (17.9 cells/field). There was an increase in β-cell numbers, the β- to α-cell ratio that was statistically higher in the liraglutide-treated rats (24.3±4.4) compared to vehicle (9.1±2.8). Disrupted mitochondria were more commonly observed in the α-cells (51.9±10.3% of cells) than in the β-cells (27.2±4.4%) in the liraglutide-treated group. While liraglutide enhanced or maintained growth and function of certain islet cells, the overall ratio of α- to β-cells was decreased and there was an absolute reduction in islet α-cell content. There was selective disruption of intracellular α-cell organelles, representing an uncoupling of Topics: Animals; Blood Glucose; Diabetes Mellitus, Type 2; Glucagon; Glucagon-Like Peptide 1; Glucagon-Secreting Cells; Hypoglycemic Agents; Insulin; Insulin-Secreting Cells; Liraglutide; Male; Rats; Rats, Zucker | 2013 |
A novel glucagon-like peptide 1 peptide identified from Ophisaurus harti.
Glucagon-like peptide 1 receptor (GLP1R) is a promising target for the treatment of type 2 diabetes. Because of the short half-life of endogenous GLP1 peptide, other GLP1R agonists are considered to be appealing therapeutic candidates. A high-throughput assay has been established to screen for GLP1R agonists in a 60 000-well natural product compound library fractionated from 670 different herbs/materials widely used in traditional Chinese medicines (TCMs). The screening is based on primary screen of GLP1R⁺ reporter gene assay with the counter screen in GLP1R⁻ cell line. An active fraction, A089-147, was identified from the screening. Fraction A089-147 was isolated from dried Ophisaurus harti, and the fact that its GLP1R agonist activity was sensitive to trypsin treatment indicates its peptidic nature. The active ingredient of A089-147 was later identified as O. harti GLP1 through transcriptome analysis. Chemically synthesized O. harti GLP1 showed GLP1R agonist activity and sensitivity to dipeptidase IV digestion. This study illustrated a comprehensive screening strategy to identify novel GLP1R agonists from TCMs libraries and at the same time underlined the difficulty of identifying a non-peptidic GLP1R agonist. The novel O. harti GLP1 peptide yielded from this study confirmed broader application of TCMs libraries in active peptide identification. Topics: Amino Acid Sequence; Animals; Conserved Sequence; Diabetes Mellitus, Type 2; Dipeptidyl Peptidase 4; Drug Evaluation, Preclinical; Gastrointestinal Tract; Glucagon-Like Peptide 1; Glucagon-Like Peptide-1 Receptor; HEK293 Cells; Humans; Hypoglycemic Agents; Lizards; Medicine, Chinese Traditional; Molecular Sequence Data; Proteolysis; Receptors, Glucagon; Reptilian Proteins; Sequence Analysis, Protein; Small Molecule Libraries; Transcriptome | 2013 |
[Impacts of laparoscopic bariatric surgery on GLP-1 and Ghrelin level in patients with type 2 diabetes mellitus].
To investigate the impacts of laparoscopic bariatric surgery on fasting glucagon-like peptide-1 (GLP-1) and Ghrelin level in patients with type 2 diabetes mellitus (T2DM), and the mechanism in surgical treatment of T2DM.. From March 2010 to August 2011, 44 patients with T2DM underwent laparoscopic bariatric, including laparoscopic Roux-en-Y gastric bypass (LRYGB, n = 14), laparoscopic mini-gastric bypass (LMGB, n = 11), laparoscopic sleeve gastrectomy (LSG, n = 9) and laparoscopic adjustable gastric banding (LAGB, n = 10). The curative effects, changes of metabolism and gastrointestinal hormones were analyzed respectively.. Within 6 months after surgery, the clinical complete remission of T2DM was 11, 8, 6, 3 cases in LRYGB, LMGB, LSG, LAGB group respectively; the clinical partial remission was 3, 3, 2, 4 cases respectively. The inefficacy was 1, 3 patients in LSG and LAGB group respectively. The effects of surgery within 6 months postoperative among 4 groups were different (χ(2) = 8.162, P < 0.05). The levels of body mass index (F = 275.29) and homeostasis model assessment of insulin resistance (F = 40.09) of 4 groups were declined in 6 months postoperatively (P < 0.01). The extents of decrease were no significance among 4 groups. Compared to preoperative level, GLP-1 in LRYGB ((116 ± 33) vs. (66 ± 20) ng/L and LMGB group ((103 ± 22) vs. (65 ± 16) ng/L) was higher in the first month after surgery (F = 21.76 and 139.21, P < 0.05). The changes in LSG and LAGB group were no significance (P > 0.05). The level of Ghrelin in LRYGB, LMGB, LSG group at the first week after surgery were (208 ± 79), (275 ± 102) and (258 ± 91) ng/L respectively, and they were lower than preoperative (there were (398 ± 114), (439 ± 96) and (446 ± 105) ng/L, F = 55.08, 49.96 and 46.47, all P < 0.01). But the level of Ghrelin in LRYGB and LMGB groups rebounded in the first postoperative month. The postoperative level of Ghrelin was higher in LAGB group (F = 29.24, P = 0.001).. There are difference efficacies and impacts on gastrointestinal hormones among different modes of bariatric surgery. The change of gastrointestinal hormones is plausible mechanism of T2DM remission after surgery. Topics: Adult; Diabetes Mellitus, Type 2; Endoscopy, Gastrointestinal; Female; Gastrectomy; Ghrelin; Glucagon-Like Peptide 1; Humans; Laparoscopy; Male; Middle Aged; Obesity, Morbid; Young Adult | 2013 |
Subcutaneous administration of liraglutide ameliorates Alzheimer-associated tau hyperphosphorylation in rats with type 2 diabetes.
Type 2 diabetes increases the risk for developing Alzheimer's disease (AD), a progressive neurodegenerative disorder. Brain insulin resistance contributes to the pathogenesis of AD, and abnormal hyperphosphorylation of tau protein is crucial to neurodegeneration. Here we studied whether liraglutide, an agonist of glucagon-like peptide-1 (GLP-1) and a new anti-diabetic drug, can promote brain insulin signaling and inhibit tau hyperphosphorylation in the brains of type 2 diabetic rats.. Type 2 diabetic rats were treated with subcutaneous administration of liraglutide (0.2 mg/kg body weight) or, as a control, saline twice a day for up to four weeks. Blood, cerebrospinal fluid (CSF), and brain tissue (n = 7 each group) were collected for analyses after liraglutide or saline administration for one, two, three, and four weeks.. We found decreased CSF insulin, hyperphosphorylation of tau at AD-relevant phosphorylation sites, and decreased phosphorylation of protein kinase B (AKT) and glycogen synthase kinase-3β (GSK-3β) in the brain, which indicated decreased insulin signaling leading to overactivation of GSK-3β, a major tau kinase, in type 2 diabetic rats. Liraglutide treatment not only ameliorated hyperglycemia and peripheral insulin resistance, but also reversed these brain abnormalities in a time-dependent manner.. Our results indicated that subcutaneous administration of liraglutide restores both peripheral and brain insulin sensitivity and ameliorates tau hyperphosphorylation in rats with type 2 diabetes. These findings support the potential use of liraglutide for the prevention and treatment of AD in individuals with type 2 diabetes. Topics: Alzheimer Disease; Animals; Diabetes Mellitus, Type 2; Glucagon-Like Peptide 1; Hypoglycemic Agents; Injections, Subcutaneous; Liraglutide; Male; Phosphorylation; Random Allocation; Rats; Rats, Wistar; tau Proteins | 2013 |
Short-term glucose metabolism and gut hormone modulations after Billroth II gastrojejunostomy in nonobese gastric cancer patients with type 2 diabetes mellitus, impaired glucose tolerance and normal glucose tolerance.
Roux-en-Y gastric bypass (RYGB) is effective in controlling blood glucose in obese patients with type 2 diabetes (T2DM). The alterations of gut hormones involving in glucose metabolism may play an important role. Our aim was to explore the short-term effects of Billroth II gastrojejunostomy (a similar type of RYGB) on glucose metabolism and gut hormone modulations in nonobese patients with different levels of blood glucose tolerance.. Twenty one nonobese gastric cancer patients with different levels of blood glucose tolerance were submitted to Billroth II gastrojejunostomy. Among them, seven had T2DM, seven with impaired glucose tolerance (IGT) and the other seven had normal glucose tolerance (NGT). Body weight, glucose parameters, responses of plasma glucagon-like peptide-1 (GLP-1), peptide YY (PYY) and gastric inhibitory polypeptide (GIP) to 75 g glucose were measured at baseline and 3 months after surgery.. Similar weight losses were observed in all groups. Blood glucose was reduced in T2DM and IGT patients. Fasting and 30-min plasma glucose were increased significantly in NGT. GLP-1 showed insignificant alterations in all groups. PYY was evaluated in T2DM and IGT but remained unchanged in the NGT group. Decreased fasting and AUC GIP were observed in patients with T2DM; however, fasting and 30-min GIP were increased in NGT patients.. Billroth II gastrojejunostomy is effective in reducing blood glucose in nonobese patients with T2DM and IGT but could deteriorate early blood glucose in nonobese NGT in a 3-month time period. Variations of glucose and gut hormone changes in the three groups suggest a role of proximal intestine in the pathophysiology of T2DM. Topics: Adult; Aged; Area Under Curve; Blood Glucose; Diabetes Mellitus, Type 2; Female; Gastric Bypass; Gastric Inhibitory Polypeptide; Glucagon-Like Peptide 1; Glucose Intolerance; Glucose Tolerance Test; Glycated Hemoglobin; Humans; Insulin; Male; Middle Aged; Obesity; Peptide YY; Postoperative Period; Stomach Neoplasms; Weight Loss | 2013 |
Lipotoxicity disrupts incretin-regulated human β cell connectivity.
Pancreatic β cell dysfunction is pathognomonic of type 2 diabetes mellitus (T2DM) and is driven by environmental and genetic factors. β cell responses to glucose and to incretins such as glucagon-like peptide-1 (GLP-1) and glucose-dependent insulinotropic polypeptide (GIP) are altered in the disease state. While rodent β cells act as a coordinated syncytium to drive insulin release, this property is unexplored in human islets. In situ imaging approaches were therefore used to monitor in real time the islet dynamics underlying hormone release. We found that GLP-1 and GIP recruit a highly coordinated subnetwork of β cells that are targeted by lipotoxicity to suppress insulin secretion. Donor BMI was negatively correlated with subpopulation responses to GLP-1, suggesting that this action of incretin contributes to functional β cell mass in vivo. Conversely, exposure of mice to a high-fat diet unveiled a role for incretin in maintaining coordinated islet activity, supporting the existence of species-specific strategies to maintain normoglycemia. These findings demonstrate that β cell connectedness is an inherent property of human islets that is likely to influence incretin-potentiated insulin secretion and may be perturbed by diabetogenic insults to disrupt glucose homeostasis in humans. Topics: Animals; Blood Glucose; Body Mass Index; Calcium Signaling; Cell Communication; Cells, Cultured; Diabetes Mellitus, Type 2; Diet, High-Fat; Fatty Acids, Nonesterified; Gap Junctions; Glucagon-Like Peptide 1; Glucose; Homeostasis; Humans; Incretins; Insulin; Insulin Secretion; Insulin-Secreting Cells; Mice; Mice, Inbred C57BL; Species Specificity | 2013 |
Reversing metabolic diseases through diabetes surgery: do the proximal gut and related hormones play key roles in glucose homeostasis?
Topics: Blood Glucose; Diabetes Mellitus, Type 2; Female; Gastric Bypass; Glucagon-Like Peptide 1; Glucose Intolerance; Humans; Male; Peptide YY | 2013 |
Maternal ileal interposition surgery confers metabolic improvements to offspring independent of effects on maternal body weight in UCD-T2DM rats.
Increasing numbers of people are undergoing bariatric surgery, of which approximately half are women in their childbearing years. However, information on the long-term effects of maternal bariatric surgery in their children is lacking. Furthermore, since bariatric surgery is performed to reduce body weight, clinical studies have not been able to differentiate between benefits to the child due to maternal body weight loss versus other maternal postoperative metabolic changes. Therefore, we used the University of California, Davis, type 2 diabetes mellitus (UCD-T2DM) rat model to test the hypothesis that maternal ileal interposition (IT) surgery would confer beneficial metabolic effects in offspring, independent of effects on maternal body weight.. IT surgery was performed on 2-month-old prediabetic female UCD-T2DM rats. Females were bred 3 weeks after surgery, and male pups were studied longitudinally.. Maternal IT surgery resulted in decreased body weight in offspring compared with sham offspring (P < 0.05). IT offspring exhibited improvements of glucose-stimulated insulin secretion and nutrient-stimulated glucagon-like peptide-2 (GLP-2) secretion (P < 0.05). Fasting plasma unconjugated bile acid concentrations were 4-fold lower in IT offspring compared with sham offspring at two months of age (P < 0.001).. Overall, maternal IT surgery confers modest improvements of body weight and improves insulin secretion and nutrient-stimulated GLP-2 secretion in offspring in the UCD-T2DM rat model of type 2 diabetes, indicating that this is a useful model for investigating the weight-independent metabolic effects of maternal bariatric surgery. Topics: Animals; Blood Glucose; Diabetes Mellitus, Experimental; Diabetes Mellitus, Type 2; Female; Gastric Bypass; Glucagon-Like Peptide 1; Glucose Tolerance Test; Ileum; Lipid Metabolism; Male; Prediabetic State; Pregnancy; Rats; Weight Loss | 2013 |
SAD-A and AMPK kinases: the "yin and yang" regulators of mTORC1 signaling in pancreatic β cells.
Topics: AMP-Activated Protein Kinases; Animals; Cell Size; Diabetes Mellitus, Type 2; Gene Expression Regulation; Glucagon-Like Peptide 1; Glucose; Humans; Insulin; Insulin-Secreting Cells; Mechanistic Target of Rapamycin Complex 1; Mice; Mice, Knockout; Multiprotein Complexes; Protein Serine-Threonine Kinases; Signal Transduction; TOR Serine-Threonine Kinases | 2013 |
Roux-en-Y gastric bypass and sleeve gastrectomy: mechanisms of diabetes remission and role of gut hormones.
In obese patients with type 2 diabetes (T2DM), Roux-en-Y-gastric-bypass (RYGB) and sleeve gastrectomy (SLG) improve glycemic control.. The objective of this study was to investigate the mechanisms of surgery-induced T2DM improvement and role of gastrointestinal hormones. PATIENTS, SETTING, AND INTERVENTION: In 35 patients with T2DM, we performed a mixed-meal test before and 15 days and 1 year after surgery (23 RYGB and 12 SLG).. Insulin sensitivity, β-cell function, and amylin, ghrelin, PYY, pancreatic polypeptide (PP), glucagon, and glucagon-like peptide-1 (GLP-1) responses to the meal were measured.. T2DM remission occurred in 13 patients undergoing RYGB and in 7 patients undergoing SLG. Similarly in the RYGB and SLG groups, β-cell glucose sensitivity improved both early and long term (P < .005), whereas insulin sensitivity improved long term only (P < .006), in proportion to body mass index changes (P < .001). Early after RYGB, glucagon and GLP-1 responses to the meal increased, whereas the PP response decreased. At 1 year, PYY was increased, and PP, amylin, ghrelin, and GLP-1 were reduced. After SLG, hormonal responses were similar to those with RYGB except that PP was increased, whereas amylin was unchanged. In remitters, fasting GLP-1 was higher (P = .04), but its meal response was flat compared with that of nonremitters; postsurgery, however, the GLP-1 response was higher. Other hormone responses were similar between the 2 groups. In logistic regression, presurgery β-cell glucose sensitivity (positive, P < .0001) and meal-stimulated GLP-1 response (negative, P = .004) were the only predictors of remission.. RYGB and SLG have a similar impact on diabetes remission, of which baseline β-cell glucose sensitivity and a restored GLP-1 response are the chief determinants. Other hormonal responses are the consequences of the altered gastrointestinal anatomy. Topics: Adult; Diabetes Mellitus, Type 2; Female; Gastrectomy; Gastric Bypass; Gastrointestinal Hormones; Glucagon; Glucagon-Like Peptide 1; Glycemic Index; Humans; Insulin; Insulin Resistance; Insulin-Secreting Cells; Islet Amyloid Polypeptide; Male; Middle Aged; Obesity, Morbid; Pancreatic Polypeptide; Peptide YY; Remission Induction | 2013 |
GLP1 analogs as treatment of postprandial hypoglycemia following gastric bypass surgery: a potential new indication?
The number of morbidly obese subjects submitted to bariatric surgery is rising worldwide. In a fraction of patients undergoing gastric bypass (GBP), episodes with late postprandial hypoglycemia (PPHG) develop 1-3 years after surgery. The pathogenesis of this phenomenon is not fully understood; meal-induced rapid and exaggerated increases of circulating incretins and insulin appear to be at least partially responsible. Current treatments include low-carbohydrate diets, inhibition of glucose intestinal uptake, reduction of insulin secretion with calcium channel blockers, somatostatin analogs, or diazoxide, a KATP channel opener. Even partial pancreatectomy has been advocated. In type 2 diabetes, GLP1 analogs have a well-documented effect of stabilizing glucose levels without causing hypoglycemia.. We explored GLP1 analogs as open treatment in five consecutive GBP cases seeking medical attention because of late postprandial hypoglycemic symptoms.. Glucose measured in connection with the episodes in four of the cases had been 2.7, 2.5, 1.8, and 1.6 mmol/l respectively. The patients consistently described that the analogs eliminated their symptoms, which relapsed in four of the five patients when treatment was reduced/discontinued. The drug effect was further documented in one case by repeated 24-h continuous glucose measurements.. These open, uncontrolled observations suggest that GLP1 analogs might provide a new treatment option in patients with problems of late PPHG. Topics: Adult; Blood Glucose; Diabetes Mellitus, Type 2; Female; Gastric Bypass; Glucagon-Like Peptide 1; Humans; Hypoglycemia; Incretins; Male; Middle Aged; Obesity, Morbid; Postprandial Period; Treatment Outcome | 2013 |
Glucagon-like peptide 1-based drugs and pancreatic safety.
Topics: Diabetes Mellitus, Type 2; Female; Glucagon-Like Peptide 1; Hospitalization; Humans; Male; Pancreatitis | 2013 |
Glucagon-like peptide 1-based drugs and pancreatic safety.
Topics: Diabetes Mellitus, Type 2; Female; Glucagon-Like Peptide 1; Hospitalization; Humans; Male; Pancreatitis | 2013 |
Glucagon-like peptide 1-based drugs and pancreatic safety--reply.
Topics: Diabetes Mellitus, Type 2; Female; Glucagon-Like Peptide 1; Hospitalization; Humans; Male; Pancreatitis | 2013 |
Resistant starch intake at breakfast affects postprandial responses in type 2 diabetics and enhances the glucose-dependent insulinotropic polypeptide--insulin relationship following a second meal.
Resistant starch (RS) consumption can modulate postprandial metabolic responses, but its effects on carbohydrate (CHO) handling in type 2 diabetics (T2D) are unclear. It was hypothesized that a bagel high in RS would improve glucose and insulin homeostasis following the 1st meal, regardless of the amount of available CHO, and that in association with incretins, the effects would carry over to a 2nd meal. Using a randomized crossover design, 12 T2D ingested four different bagel treatments (their 1st meal) determined by available CHO and the weight or amount of bagel consumed: treatment A, without RS (50 g of available CHO); treatment B, with RS (same total CHO as in A); treatment C, with RS (same available CHO as in A); and treatment D, with the same RS as in B and available CHO as in A and C. A standard 2nd meal was ingested 3 h later. Following the first meal, B elicited a lower glucose incremental area under the curve (iAUC) than C (P < 0.05), D (P < 0.05), and A (trend; P = 0.07), lower insulin iAUC than A (P < 0.05) and C (P < 0.05), and lower glucose-dependent insulinotropic polypeptide (GIP) iAUC than A (P < 0.05). There was a positive correlation (P < 0.05) between GIP and insulin iAUCs after the 2nd meal, and C had a 3 times greater slope than the other treatments (r = 0.91, P < 0.001), yet lacked a significant concomitant improvement in glucose disposal. These results show that for the 1st meal, RS was effective when it replaced a portion of the available CHO, while ingesting more RS influenced the GIP-insulin axis following the 2nd meal. Topics: Blood Glucose; Breakfast; Diabetes Mellitus, Type 2; Gastric Inhibitory Polypeptide; Glucagon-Like Peptide 1; Glucose; Humans; Insulin; Postprandial Period; Starch | 2013 |
Novel AGLP-1 albumin fusion protein as a long-lasting agent for type 2 diabetes.
Glucagon like peptide-1 (GLP-1) regulates glucose mediated-insulin secretion, nutrient accumulation, and β-cell growth. Despite the potential therapeutic usage for type 2 diabetes (T2D), GLP-1 has a short half-life in vivo (t(1/2) <2 min). In an attempt to prolong half-life, GLP-1 fusion proteins were genetically engineered: GLP-1 human serum albumin fusion (GLP-1/HSA), AGLP-1/HSA which has an additional alanine at the N-terminus of GLP-1, and AGLP-1-L/HSA, in which a peptide linker is inserted between AGLP-1 and HSA. Recombinant fusion proteins secreted from the Chinese Hamster Ovary-K1 (CHO-K1) cell line were purified with high purity (>96%). AGLP-1 fusion protein was resistant against the dipeptidyl peptidase-IV (DPP-IV). The fusion proteins activated cAMP-mediated signaling in rat insulinoma INS-1 cells. Furthermore, a C57BL/6N mice pharmacodynamics study exhibited that AGLP-1-L/HSA effectively reduced blood glucose level compared to AGLP-1/HSA. Topics: Alanine; Animals; Blood Glucose; Cell Line, Tumor; CHO Cells; Cricetinae; Cricetulus; Diabetes Mellitus, Type 2; Dipeptidyl Peptidase 4; Glucagon-Like Peptide 1; Glucose Tolerance Test; Half-Life; Humans; Hypoglycemic Agents; Mice; Mice, Inbred C57BL; Rats; Recombinant Fusion Proteins; Serum Albumin; Transfection | 2013 |
Diabetes treatment: recent developments.
Topics: Blood Glucose; Diabetes Mellitus, Type 2; Female; Glucagon-Like Peptide 1; Humans; Hypoglycemic Agents; Incidence; Insulin; Male; Quality Improvement; Risk Assessment; Treatment Outcome | 2013 |
The INITIATOR study: pilot data on real-world clinical and economic outcomes in US patients with type 2 diabetes initiating injectable therapy.
Type 2 diabetes mellitus (T2DM) progression often results in treatment intensification with injectable therapy to maintain glycemic control. Using pilot data from the Initiation of New Injectable Treatment Introduced after Anti-diabetic Therapy with Oral-only Regimens study, real-world treatment patterns among T2DM patients initiating injectable therapy with insulin glargine or liraglutide were assessed.. This was a retrospective analysis of claims from the OptumInsight™ (OI; January 1, 2010 to July 30, 2010) and HealthCore(®) (HC; January 1, 2010 to June 1, 2010) health insurance databases. Baseline characteristics, health care resource utilization, and costs were compared between adults with T2DM initiating injectable therapy with insulin glargine pen versus liraglutide. Follow-up outcomes, including glycated hemoglobin A1c (A1C), hypoglycemia, health care utilization, and costs, were assessed.. At baseline, almost one in three liraglutide patients (OI, n = 363; HC, n = 521) had A1C <7.0%, while insulin glargine patients (OI, n = 498; HC, n = 1,188) had poorer health status, higher A1C (insulin glargine: 9.8% and 9.1% versus liraglutide: 7.9% and 7.7%, OI and HC, respectively, both P < 0.001), and were less likely to be obese (insulin glargine: 10.8% and 9.2% versus liraglutide: 17.4% and 18.8%, OI and HC, respectively, both P < 0.01). The percentage of patients experiencing a hypoglycemic event was numerically higher for insulin pen use for both cohorts (OI 4.4% versus 3.0%; HC 6.2% versus 2.3%). During follow-up, in the insulin glargine cohort, annualized diabetes-related costs remained unchanged ($8,344 versus $7,749 OI, and $7,094 versus $7,731 HC), despite a significant increase in pharmacy costs, due to non-significant decreases in medical costs, while the liraglutide cohort had a significant increase in annualized diabetes-related costs ($4,510 versus $7,731 OI, and $4,136 versus $7,111 HC; both P < 0.001) due to a non-significant increase in medical costs coupled with a significant increase in pharmacy costs.. These descriptive data identified differences in demographic and baseline clinical characteristics among patients initiating injectable therapies. The different health care utilization and cost patterns warrant further cost-effectiveness analysis. Topics: Adult; Aged; Blood Glucose; Cohort Studies; Cost-Benefit Analysis; Databases, Factual; Diabetes Mellitus, Type 2; Disposable Equipment; Dose-Response Relationship, Drug; Drug Administration Schedule; Female; Glucagon-Like Peptide 1; Health Care Costs; Humans; Hypoglycemic Agents; Injections, Subcutaneous; Insulin Glargine; Insulin, Long-Acting; Liraglutide; Male; Middle Aged; Pilot Projects; Retrospective Studies; Severity of Illness Index; Statistics, Nonparametric; Syringes; Treatment Outcome; United States | 2013 |
Sitagliptin reduces cardiac apoptosis, hypertrophy and fibrosis primarily by insulin-dependent mechanisms in experimental type-II diabetes. Potential roles of GLP-1 isoforms.
Myocardial fibrosis is a key process in diabetic cardiomyopathy. However, their underlying mechanisms have not been elucidated, leading to a lack of therapy. The glucagon-like peptide-1 (GLP-1) enhancer, sitagliptin, reduces hyperglycemia but may also trigger direct effects on the heart.. Goto-Kakizaki (GK) rats developed type-II diabetes and received sitagliptin, an anti-hyperglycemic drug (metformin) or vehicle (n=10, each). After cardiac structure and function assessment, plasma and left ventricles were isolated for biochemical studies. Cultured cardiomyocytes and fibroblasts were used for in vitro assays.. Untreated GK rats exhibited hyperglycemia, hyperlipidemia, plasma GLP-1 decrease, and cardiac cell-death, hypertrophy, fibrosis and prolonged deceleration time. Moreover, cardiac pro-apoptotic/necrotic, hypertrophic and fibrotic factors were up-regulated. Importantly, both sitagliptin and metformin lessened all these parameters. In cultured cardiomyocytes and cardiac fibroblasts, high-concentration of palmitate or glucose induced cell-death, hypertrophy and fibrosis. Interestingly, GLP-1 and its insulinotropic-inactive metabolite, GLP-1(9-36), alleviated these responses. In addition, despite a specific GLP-1 receptor was only detected in cardiomyocytes, GLP-1 isoforms attenuated the pro-fibrotic expression in cardiomyocytes and fibroblasts. In addition, GLP-1 receptor signalling may be linked to PPARδ activation, and metformin may also exhibit anti-apoptotic/necrotic and anti-fibrotic direct effects in cardiac cells.. Sitagliptin, via GLP-1 stabilization, promoted cardioprotection in type-II diabetic hearts primarily by limiting hyperglycemia e hyperlipidemia. However, GLP-1 and GLP-1(9-36) promoted survival and anti-hypertrophic/fibrotic effects on cultured cardiac cells, suggesting cell-autonomous cardioprotective actions. Topics: Animals; Apoptosis; Cardiomegaly; Cardiotonic Agents; Cells, Cultured; Diabetes Mellitus, Type 2; Diabetic Cardiomyopathies; Disease Models, Animal; Drug Evaluation, Preclinical; Fibroblasts; Fibronectins; Fibrosis; Glucagon-Like Peptide 1; Glucose Intolerance; Hypoglycemic Agents; Insulin; Male; Metformin; Myocardium; Myocytes, Cardiac; PPAR delta; Protein Isoforms; Pyrazines; Rats; Sitagliptin Phosphate; Triazoles | 2013 |
[The changes of gastrointestinal hormones GLP-1, PYY and ghrelin in patients with newly diagnosed type 2 diabetes mellitus].
To study the changes of plasma glucagon-like peptide-1 (GLP-1), serum peptide-YY (PYY) and Ghrelin and their secretion functions in patients with newly diagnosed type 2 diabetes mellitus (T2DM).. A total of 102 subjects were enrolled, including 32 normal-glucose-tolerance controls (NGT) and 70 patients with newly diagnosed T2DM. Height, body mass, waist circumference (WC) and hip circumference were measured. The plasma lipids and 0 h, 1/2 h, 2 h plasma glucose, insulin (INS), GLP-1, serum PYY and Ghrelin in a standard meal test in each subject were detected, and body mass index (BMI), homeostasis model assessment of insulin resistance (HOMA-IR), insulin sensitivity index (ISI), homeostasis model assessment of beta cell function (HOMA-B) and early insulin secretion function index (DeltaI30/DeltaG30) were calculated. All these variables were compared between the two groups.. Compared with those in NGT group, the WC, fasting plasma glucose (FPG), postprandial plasma glucose (2 h-PG), triglyceride (TG), HOMA-IR were significantly higher (P 0.05), while INS(30), HOMA-B, ISI, DeltaI30/DeltaG30 were significantly lower in T2DM group (P<0. 05). In addition, in T2DM group, 0 h, 1/2 h, 2 h plasma GLP-1 and serum PYY and the area under the curve (AUC) of GLP-1 (GLP-lAuc ) and PYY (PYYAc) in standard meal test were significantly lower (P<0. 05), but the serum Ghrelin and GhrelinA, were significantly higher (P<0. 05). Meanwhile, the secretory peak of GLP-1 and PYY after standard meal in T2DM patients all disappeared. In T2DM group, PYYAUC and TG were negatively correlated (P<0.05), the fasting serum Ghrelin level was negatively associated with total cholesterol (TC), and GhrelinAuc was positively associated with HOMA-B, but negatively with the low-density lipoprotein cholesterol (LDL-C) and FPG (P(<0. 05).. Patients with newly diagnosed T2DM have decreased fasting and postprandial GLP-1 and PYY levels, along with changes of their secretion mode and increased levels of Ghrelin. Topics: Adult; Case-Control Studies; Diabetes Mellitus, Type 2; Female; Ghrelin; Glucagon-Like Peptide 1; Humans; Male; Middle Aged; Peptide YY | 2013 |
[The body's own signaling system--now as treatment].
Topics: Awards and Prizes; Blood Glucose; Denmark; Diabetes Mellitus, Type 2; Glucagon-Like Peptide 1; Humans; Incretins; Receptors, Glucagon | 2013 |
[The effects of gastric bypass procedures on blood glucose, gastric inhibitory polypeptide and glucagon-like peptide-1 of normal glucose tolerance dogs].
To observe postoperative glucose tolerance, gastric inhibitory polypeptide (GIP) , and glucogan-like peptide-1 (GLP-1) in normal glucose level dogs after undergoing gastric bypass procedures, and to explore the mechanism of gastric bypass procedures to treat type 2 diabetes.. The 6 dogs with normal glucose tolerance had undergone gastric bypass procedures, and measure preoperative and postoperative oral and intravenous glucose tolerance (at time points 1, 2, and 4 weeks) through changes in blood glucose, insulin, gastric inhibitory polypeptide (GIP), glucagon-like peptide-1 (GLP-1), and measure preoperative and postoperative week 4 pancreatic tissue morphology.. Second weeks after operation, the fasting blood sugar was (3.58 ± 0.33) mmol/L, and significantly lower than preoperative (t = 3.571, P < 0.05). The GLP-1 level before oral glucose tolerance test (OGTT) and 30 minutes after OGTT were (0.90 ± 0.21) and (0.91 ± 0.19) pmol/L respectively, and significantly higher than preoperative (t value were -3.660 and -2.971, P < 0.05). GLP-1 levels began to decrease in the second week after surgery. After 4 weeks, the index recovered to the preoperative level. Four weeks after surgery when compared with preoperative, islet morphology, islet number (6.8 ± 0.8 and 7.1 ± 0.8 respectively) and islet cells (16.7 ± 2.5 and 16.3 ± 3.1 respectively) did not change significantly (P > 0.05).. Gastric bypass procedures could be briefly affect normal glucose tolerance in dogs' blood glucose, insulin and diabetes-related gastrointestinal hormones. Topics: Animals; Blood Glucose; Diabetes Mellitus, Type 2; Dogs; Gastric Bypass; Gastric Inhibitory Polypeptide; Glucagon; Glucagon-Like Peptide 1; Glucose; Insulin | 2013 |
[Effects of anti-diabetic therapy on overweight/obesity and dyslipidemia: traditional hypoglycemic agents (metformin, sulfonylureas, thiazolidinediones) versus glucagon-like peptide-1 analogs and dipeptidyl peptidase-4 inhibitors].
Obesity and dyslipidemia often coexist in patients with type 2 diabetes and contribute to increase the risk of cardiovascular events. Pharmacological treatments of diabetes often result in weight gain, an undesirable event associated with a worse cardiovascular risk profile and decreased adherence to therapy. Dipeptidyl peptidase-4 (DPP-4) inhibitors and glucagon-like peptide-1 (GLP-1) analogs have been shown to improve glycemic control without promoting weight gain and to exert beneficial effects on lipid profile by reducing total and LDL cholesterol, triglycerides, and free fatty acid levels. DPP-4 inhibitors have demonstrated to be weight neutral whereas treatment with GLP-1 analogs is associated with a significant weight loss. DPP-4 and GLP-1 analogs represent a new therapeutic option for type 2 diabetes, which offers the advantage of combining glycemic control with beneficial effects on body weight and lipid profile, thus providing greater cardiovascular protection. Topics: Body Weight; Cardiovascular Diseases; Diabetes Mellitus, Type 2; Dipeptidyl-Peptidase IV Inhibitors; Dipeptidyl-Peptidases and Tripeptidyl-Peptidases; Drug Therapy, Combination; Dyslipidemias; Glucagon-Like Peptide 1; Humans; Hypoglycemic Agents; Metformin; Obesity; Risk Factors; Thiazolidinediones | 2013 |
Expression and purification of optimized rolGLP-1, a novel GLP-1 analog, in Escherichia coli BL21(DE3) and its good glucoregulatory effect on type 2 diabetic mice.
Glucagon-like peptide-1 (GLP-1) is an incretin hormone that decreases postprandial glycemic excursions by enhancing insulin secretion but with short half-life due to rapid inactivation by enzymatic N-terminal truncation. Therefore, efforts are being made to improve the stability of GLP-1 via modifying its structure or inhibiting dipeptidylpeptidase IV (DPP IV), which is responsible for its degradation. GLP-M, consisting of 10 tandem repeated rolGLP-1 (GLP-1 analog), has been expressed in Pichia pastoris by our laboratory. Although it had a long effect of maintaining glucose homeostasis, redundant amino acids and purification tag limited its application. Here, optimized rolGLP-1(GLPO) with no redundant amino acids and purification tag was constructed by molecular cloning and site-directed mutagenesis, which was expressed efficiently in Escherichia coli BL21(DE3) with the production of 81.5 mg/L, and confirmed by the results of SDS-PAGE electrophoresis and Western Blotting. Then GLP-O was purified via ion exchange chromatography and gel filtration chromatography. The purity of GLP-O was close to 100%. GLP-O could be cut into single rolGLP-1 by trypsin in vitro, and rolGLP-1 had anti-trypsin activity. After oral administration of GLP-O for 4 weeks, the level of blood glucose in type 2 diabetic mice was lowered effectively, and the oral glucose tolerance of mice was improved significantly. These results settled the foundation for further clinical application of GLP-O. Topics: Animals; Blood Glucose; Cloning, Molecular; Diabetes Mellitus, Type 2; Dose-Response Relationship, Drug; Escherichia coli; Glucagon-Like Peptide 1; Insulin Resistance; Male; Mice; Mice, Inbred C57BL; Pichia; Protein Engineering; Treatment Outcome | 2013 |
A tripeptide Diapin effectively lowers blood glucose levels in male type 2 diabetes mice by increasing blood levels of insulin and GLP-1.
The prevalence of type 2 diabetes (T2D) is rapidly increasing worldwide. Effective therapies, such as insulin and Glucagon-like peptide-1 (GLP-1), require injections, which are costly and result in less patient compliance. Here, we report the identification of a tripeptide with significant potential to treat T2D. The peptide, referred to as Diapin, is comprised of three natural L-amino acids, GlyGlyLeu. Glucose tolerance tests showed that oral administration of Diapin effectively lowered blood glucose after oral glucose loading in both normal C57BL/6J mice and T2D mouse models, including KKay, db/db, ob/ob mice, and high fat diet-induced obesity/T2D mice. In addition, Diapin treatment significantly reduced casual blood glucose in KKay diabetic mice in a time-dependent manner without causing hypoglycemia. Furthermore, we found that plasma GLP-1 and insulin levels in diabetic models were significantly increased with Diapin treatment compared to that in the controls. In summary, our findings establish that a peptide with minimum of three amino acids can improve glucose homeostasis and Diapin shows promise as a novel pharmaceutical agent to treat patients with T2D through its dual effects on GLP-1 and insulin secretion. Topics: Animals; Blood Glucose; Diabetes Mellitus, Type 2; Disease Models, Animal; Glucagon-Like Peptide 1; Hypoglycemic Agents; Insulin; Male; Mice; Mice, Inbred C57BL; Oligopeptides; Time Factors | 2013 |
[Rationale supporting basal insulin-incretin combined therapies in type 2 diabetes].
Type 2 diabetes is characterized by an insulin secretory defect that cannot compensate for insulin resistance. Such relative defect is present in the fasting state (insufficient basal insulin levels) and contributes to overnight hyperglycaemia; it is even more pronounced in the postprandial state when it is then the main responsible factor for hyperglycaemia following meals. An original approach to correct these two disturbances is to propose a therapy combining the injection of a basal insulin (most commonly at bedtime to better control fasting glycaemia) and the administration of an incretin-based medication to potentiate insulin response to the three main meals, without inducing hypoglycaemia. This latter effect can be obtained either by blocking the degradation of incretin hormones with an oral inhibitor of dipeptidyl peptidase-4 (gliptin), or by injecting an agonist of glucagon-like peptide-1 (GLP-1) receptors. These basal insulin-incretin combined therapies are well validated in various controlled trials and observational studies. Lixisenatide is the first GLP-1 receptor agonist being reimbursed in this specific indication of combination with basal insulin in Belgium. Topics: Diabetes Mellitus, Type 2; Dipeptidyl-Peptidase IV Inhibitors; Drug Therapy, Combination; Glucagon-Like Peptide 1; Humans; Hypoglycemic Agents; Incretins; Insulin | 2013 |
[Liraglutide reduces biomarkers and vascular risk in patients with diabetes mellitus type 2].
Topics: Adolescent; Adult; Aged; Aged, 80 and over; Biomarkers; Diabetes Mellitus, Type 2; Female; Glucagon-Like Peptide 1; Humans; Hypoglycemic Agents; Liraglutide; Male; Middle Aged; Risk Assessment; Young Adult | 2013 |
Glucagon-like peptide-1 analogue therapy for psoriasis patients with obesity and type 2 diabetes: a prospective cohort study.
Diabetes and obesity are more prevalent amongst psoriasis patients as is disturbance of the innate immune system. GLP-1 analogue therapy considerably improves weight and glycaemic control in people with type 2 diabetes and its receptor is present on innate immune cells.. We aimed to determine the effect of liraglutide, a GLP-1 analogue, on psoriasis severity.. Before and after 10 weeks of liraglutide therapy (1.2 mg subcutaneously daily) we determined the psoriasis area and severity index (PASI) and the dermatology life quality index (DLQI) in seven people with both psoriasis and diabetes (median age 48 years, median body mass index 48.2 kg/m(2) ). We also evaluated the immunomodulatory properties of liraglutide by measuring circulating lymphocyte subset numbers and monocyte cytokine production.. Liraglutide therapy decreased the median PASI from 4.8 to 3.0 (P = 0.03) and the median DLQI from 6.0 to 2.0 (P = 0.03). Weight and glycaemic control improved significantly. Circulating invariant natural killer T (iNKT) cells increased from 0.13% of T lymphocytes to 0.40% (P = 0.03). Liraglutide therapy also effected a non-significant 54% decrease in the proportion of circulating monocytes that produced tumour necrosis factor alpha (P = 0.07).. GLP-1 analogue therapy improves psoriasis severity, increases circulating iNKT cell number and modulates monocyte cytokine secretion. These effects may result from improvements in weight and glycaemic control as well as from direct immune effects of GLP-1 receptor activation. Prospective controlled trials of GLP-1 therapies are warranted, across all weight groups, in psoriasis patients with and without type 2 diabetes. Topics: Adult; Aged; Animals; Cats; Diabetes Mellitus, Type 2; Female; Glucagon-Like Peptide 1; Humans; Liraglutide; Male; Obesity; Prospective Studies; Psoriasis | 2013 |
The novel GLP-1-gastrin dual agonist, ZP3022, increases β-cell mass and prevents diabetes in db/db mice.
Diabetes is characterized by β-cell deficiency, and therefore restoration of β-cell function has been suggested as a potential therapy. We hypothesized that a novel glucagon-like peptide-1 (GLP-1)-gastrin dual agonist, ZP3022, improves glycaemic control via improvement of β-cell status in db/db mice.. Diabetic mice were studied following short- or long-term treatment with either the GLP-1-gastrin dual agonist or the commercially available GLP-1 agonists (exendin-4 and liraglutide). The effects on glycaemic control were addressed by repeated glucose tolerance tests and/or measurements of HbA1c levels, and pancreatic islet and β-cell masses were determined by stereology.. ZP3022 and the pure GLP-1 agonists improved glycaemic control after both short- and long-term treatment compared with vehicle. Interestingly, the effect was sustainable only in mice treated with ZP3022. Stereology data displayed a dose-dependent increase of β-cell mass (p < 0.05) following treatment with ZP3022, whereas no significant effect of liraglutide was observed (β-cell mass: vehicle 3.7 ± 0.2 mg; liraglutide (30 nmol/kg) 3.4 ± 0.5 mg; ZP3022 (30 nmol/kg) 4.3 ± 0.4 mg and ZP3022 (100 nmol/kg) 5.2 ± 0.4 mg).. The novel GLP-1-gastrin dual agonist, ZP3022, improved glycaemic control in db/db mice, and pancreatic islet and β-cell mass increased significantly following treatment with ZP3022 compared with vehicle. Topics: Animals; Diabetes Mellitus, Experimental; Diabetes Mellitus, Type 2; Exenatide; Gastrins; Glucagon-Like Peptide 1; Hypoglycemic Agents; Insulin; Insulin-Secreting Cells; Liraglutide; Male; Mice; Mice, Inbred C57BL; Peptides; Venoms | 2013 |
Evaluating insulin secretagogues in a humanized mouse model with functional human islets.
To develop a rapid, easy and clinically relevant in vivo model to evaluate novel insulin secretagogues on human islets, we investigated the effect of insulin secretagogues on functional human islets in a humanized mouse model.. Human islets were transplanted under the kidney capsule of streptozotocin (STZ)-induced diabetic mice with immunodeficiency. Human islet graft function was monitored by measuring non-fasting blood glucose levels. After diabetes was reversed, human islet transplanted mice were characterized physiologically by oral glucose tolerance and pharmacologically with clinically proven insulin secretagogues, glucagon-like peptide-1 (GLP-1), exenatide, glyburide, nateglinide and sitagliptin. Additionally, G protein-coupled receptor 40 (GPR40) agonists were evaluated in this model.. Long-term human islet graft survival could be achieved in immunodeficient mice. Oral glucose challenge in human islet transplanted mice resulted in an immediate incremental increase of plasma human C-peptide, while the plasma mouse C-peptide was undetectable. Treatments with GLP-1, exenatide, glyburide, nateglinide and sitagliptin effectively increased plasma human C-peptide levels and improved postprandial glucose concentrations. GPR40 agonists also stimulated human C-peptide secretion and significantly improved postprandial glucose in the human islet transplanted mice.. Our studies indicate that a humanized mouse model with human islet grafts could mimic the in vivo characteristics of human islets and could be a powerful tool for the evaluation of novel insulin secretagogues or other therapeutic agents that directly and/or indirectly target human β cells. Topics: Animals; Blood Glucose; Cyclohexanes; Diabetes Mellitus, Experimental; Diabetes Mellitus, Type 2; Exenatide; Glucagon-Like Peptide 1; Glucose Tolerance Test; Glyburide; Humans; Incretins; Insulin; Insulin Secretion; Islets of Langerhans; Islets of Langerhans Transplantation; Male; Mice; Mice, Nude; Nateglinide; Peptides; Phenylalanine; Pyrazines; Sitagliptin Phosphate; Specific Pathogen-Free Organisms; Triazoles; Venoms | 2013 |
Liraglutide prevents diabetes progression in prediabetic OLETF rats.
One of human GLP-1 analogues, liraglutide has been approved as adjuvant therapy to oral medication in T2DM. It was also shown to prevent diabetes in obese subjects and rats. However, it is unknown whether liraglutide can effectively mitigate the effects of prediabetes. We therefore investigate this by treating 12-weeks old Otsuka-Long-Evans-Tokushima fatty (OLETF) rats with liraglutide 50, 100, and 200 μg/kg, respectively twice a day for 12 weeks. Eight Long-Evans-Tokushima-Otsuka (LETO) rats with saline injection served as normal controls. Body weight, food intake, lipid profiles, inflammatory markers (fibrinogen, Hs-CRP, IL-6, TNFα, and PAI-1), glycemic metabolism and insulin sensitivity, and apoptotic factors (Bcl-2 and Bax) expression were monitored. We found that 12-week old OLETF rats had significantly increased body weight, food intake, serum levels of lipid profiles, inflammatory markers, and insulin compared to LETO rats. FPG level was significantly increased but still lower than 7mmol/L without impaired glucose tolerance (IGT). After 12 weeks, vehicle-treated OLETF rats had further deterioration in IFG, IGT, insulin resistance, lipid profiles, and inflammatory state. Pancreatic islets were hypertrophic with distorted structure, scarring, and inflammatory cell infiltration. However, in the three liraglutide-treated groups, IFG, IGT, the increased lipid profiles and inflammatory markers were reversed. Insulin resistance was similar to the level before the treatment. Moreover, liraglutide restored the islet structure, up-regulated Bcl-2 expression and down-regulated Bax expression. It indicated that liraglutide could suppress diabetes onset in OLETF rats with prediabetes, probably by reserving β cell function via regulating apoptotic factors as well as ameliorating lipid metabolism and inflammatory reactions. Topics: Animals; Biomarkers; Blood Glucose; Body Weight; Diabetes Mellitus, Type 2; Disease Progression; Eating; Glucagon-Like Peptide 1; Hypoglycemic Agents; Insulin; Islets of Langerhans; Liraglutide; Prediabetic State; Rats; Rats, Inbred OLETF | 2013 |
Automated recognition and quantification of pancreatic islets in Zucker diabetic fatty rats treated with exendin-4.
Type 2 diabetes is characterized by impaired insulin secretion from pancreatic β-cells. Quantification of the islet area in addition to the insulin-positive area is important for detailed understanding of pancreatic islet histopathology. Here we show computerized automatic recognition of the islets of Langerhans as a novel high-throughput method to quantify islet histopathology. We utilized state-of-the-art tissue pattern recognition software to enable automatic recognition of islets, eliminating the need to laboriously trace islet borders by hand. After training by a histologist, the software successfully recognized even irregularly shaped islets with depleted insulin immunostaining, which were quite difficult to automatically recognize. The results from automated image analysis were highly correlated with those from manual image analysis. To establish whether this automated, rapid, and objective determination of islet area will facilitate studies of islet histopathology, we showed the beneficial effect of chronic exendin-4, a glucagon-like peptide-1 analog, treatment on islet histopathology in Zucker diabetic fatty (ZDF) rats. Automated image analysis provided qualitative and quantitative evidence that exendin-4 treatment ameliorated the loss of pancreatic insulin content and gave rise to islet hypertrophy. We also showed that glucagon-positive α-cell area was decreased significantly in ZDF rat islets with disorganized structure. This study is the first to demonstrate the utility of automatic quantification of digital images to study pancreatic islet histopathology. The proposed method will facilitate evaluations in preclinical drug efficacy studies as well as elucidation of the pathophysiology of diabetes. Topics: Animals; Artificial Intelligence; Diabetes Mellitus, Type 2; Exenatide; Expert Systems; Glucagon; Glucagon-Like Peptide 1; Glucagon-Secreting Cells; High-Throughput Screening Assays; Hypoglycemic Agents; Insulin; Insulin-Secreting Cells; Islets of Langerhans; Male; Obesity; Pattern Recognition, Automated; Peptides; Rats; Rats, Zucker; Somatostatin; Somatostatin-Secreting Cells; Venoms | 2013 |
Effects of thirty-times chewing per bite on secretion of glucagon-like peptide-1 in healthy volunteers and type 2 diabetic patients.
Glucagon-like peptide 1 (GLP-1) is secreted from the small intestine to the blood in response to glucose intake during a meal; however, it is not known whether mastication affects GLP-1 secretion. Here, we examined the relationship between mastication and GLP-1 secretion, along with postprandial blood glucose and insulin concentrations. We compared the levels of blood glucose, serum insulin, and plasma active GLP-1 concentrations after young healthy volunteers ate a test meal either by usual eating (control) or in one of three specified ways: 1. unilateral chewing, 2. quick eating, 3. 30-times chewing per bite. Ten volunteers participated in each of the three groups. Plasma active GLP-1 concentrations did not change by unilateral chewing or quick eating, but did increase by the third method, without affecting the concentrations of blood glucose or serum insulin. Next, we tested whether 30-times chewing per bite increased plasma active GLP-1 concentrations in 15 patients with type 2 diabetes mellitus, but there was no difference in results between usual eating and 30-times chewing per bite. This is a pilot trial with a small number of subjects, but is the first study to investigate the relationships between various styles of mastication and the GLP-1 secretion in young healthy volunteers and type 2 diabetic patients. Topics: Adult; Blood Glucose; Diabetes Mellitus, Type 2; Female; Ghrelin; Glucagon-Like Peptide 1; Humans; Insulin; Male; Mastication; Pilot Projects; Postprandial Period; Young Adult | 2013 |
Comparing diabetes drugs--helping clinical decisions?
Topics: Diabetes Mellitus, Type 2; Exenatide; Glucagon-Like Peptide 1; Humans; Hypoglycemic Agents; Liraglutide; Male; Peptides; Venoms | 2013 |
Attempted suicide with liraglutide overdose did not induce hypoglycemia.
We document the first reported case of attempted suicide with the GLP-1 receptor agonist, liraglutide: a 33-year-old Japanese woman with type 2 diabetes reported subcutaneously injected 72 mg of liraglutide. She experienced gastrointestinal symptoms but no hypoglycemia. Topics: Adult; Blood Glucose; Diabetes Mellitus, Type 2; Drug Overdose; Female; Gastrointestinal Diseases; Glucagon-Like Peptide 1; Glucagon-Like Peptide-1 Receptor; Humans; Hypoglycemic Agents; Injections, Subcutaneous; Liraglutide; Receptors, Glucagon; Suicide, Attempted; Treatment Outcome | 2013 |
Effects of rectal administration of taurocholic acid on glucagon-like peptide-1 and peptide YY secretion in healthy humans.
Glucagon-like peptide-1 (GLP-1) and peptide YY (PYY), secreted by enteroendocrine L-cells located most densely in the colon and rectum, are of fundamental importance in blood glucose and appetite regulation. In animal models, colonic administration of bile acids can stimulate GLP-1 and PYY by TGR5 receptor activation. We evaluated the effects of taurocholic acid (TCA), administered as an enema, on plasma GLP-1 and PYY, as well as gastrointestinal sensations in 10 healthy male subjects, and observed that rectal administration of TCA promptly stimulated secretion of both GLP-1 and PYY, and increased fullness, in a dose-dependent manner. These observations confirm that topical application of bile acids to the distal gut may have potential for the management of type 2 diabetes and obesity. Topics: Administration, Rectal; Adult; Appetite Regulation; Blood Glucose; Body Mass Index; Cholagogues and Choleretics; Diabetes Mellitus, Type 2; Enema; Glucagon-Like Peptide 1; Humans; Male; Obesity; Peptide YY; Taurocholic Acid; Treatment Outcome | 2013 |
The novel insulin resistance parameters RBP4 and GLP-1 in patients treated with valproic acid: just a sidestep?
Valproic acid (VPA), as one of the most widely prescribed antiepileptic drugs (AED) for many types of epilepsy in adults and children, is associated with weight gain, alteration of adipocytokine homeostasis, insulin resistance and Non-Alcoholic Fatty Liver Disease (NAFLD). Retinol-binding protein 4 (RBP4) and Glucagon-like peptide-1 (GLP-1) are considered as important new targets in modern type 2 diabetes mellitus therapy linked to insulin resistance, NAFLD and visceral obesity acting via peripheral or central mechanisms. We herein demonstrate the lack of an influence of VPA treatment on RBP4 and GLP-1 in otherwise healthy patients. In summary, the absence of any relationship with RBP4 and GLP-1 concentrations does not suggest a role of these novel insulin resistance parameters as potential regulators of glucose and fat metabolism during VPA-therapy. Topics: Adolescent; Adult; Aged; Anticonvulsants; Child; Diabetes Mellitus, Type 2; Fatty Liver; Female; Glucagon-Like Peptide 1; Glucose; Homeostasis; Humans; Insulin Resistance; Liver; Male; Middle Aged; Non-alcoholic Fatty Liver Disease; Retinol-Binding Proteins, Plasma; Valproic Acid; Young Adult | 2013 |
Synthesis, characterization and pharmacodynamics of vitamin-B(12)-conjugated glucagon-like peptide-1.
Clearing the way: Glucagon-like peptide-1 (GLP-1) receptor agonists are proving a potent weapon in the treatment of type II diabetes. A new vitamin B(12)-GLP-1 conjugate is investigated and shown to have insulinotropic properties similar to the unmodified peptide. These results are critical to the exploitation of the vitamin B(12) oral uptake pathway for peptide delivery. Topics: Calcium; Diabetes Mellitus, Type 2; Glucagon-Like Peptide 1; Glucagon-Like Peptide-1 Receptor; HEK293 Cells; Humans; Hypoglycemic Agents; Insulin; Insulin Secretion; Islets of Langerhans; Receptors, Glucagon; Vitamin B 12 | 2013 |
Bile-acid-mediated decrease in endoplasmic reticulum stress: a potential contributor to the metabolic benefits of ileal interposition surgery in UCD-T2DM rats.
Post-operative increases in circulating bile acids have been suggested to contribute to the metabolic benefits of bariatric surgery; however, their mechanistic contributions remain undefined. We have previously reported that ileal interposition (IT) surgery delays the onset of type 2 diabetes in UCD-T2DM rats and increases circulating bile acids, independently of effects on energy intake or body weight. Therefore, we investigated potential mechanisms by which post-operative increases in circulating bile acids improve glucose homeostasis after IT surgery. IT, sham or no surgery was performed on 2-month-old weight-matched male UCD-T2DM rats. Animals underwent an oral fat tolerance test (OFTT) and serial oral glucose tolerance tests (OGTT). Tissues were collected at 1.5 and 4.5 months after surgery. Cell culture models were used to investigate interactions between bile acids and ER stress. IT-operated animals exhibited marked improvements in glucose and lipid metabolism, with concurrent increases in postprandial glucagon-like peptide-1 (GLP-1) secretion during the OFTT and OGTTs, independently of food intake and body weight. Measurement of circulating bile acid profiles revealed increases in circulating total bile acids in IT-operated animals, with a preferential increase in circulating cholic acid concentrations. Gut microbial populations were assessed as potential contributors to the increases in circulating bile acid concentrations, which revealed proportional increases in Gammaproteobacteria in IT-operated animals. Furthermore, IT surgery decreased all three sub-arms of ER stress signaling in liver, adipose and pancreas tissues. Amelioration of ER stress coincided with improved insulin signaling and preservation of β-cell mass in IT-operated animals. Incubation of hepatocyte, adipocyte and β-cell lines with cholic acid decreased ER stress. These results suggest that postoperative increases in circulating cholic acid concentration contribute to improvements in glucose homeostasis after IT surgery by ameliorating ER stress. Topics: Adipocytes; Animals; Bile Acids and Salts; Body Weight; Cecum; Cholic Acid; Diabetes Mellitus, Type 2; Disease Models, Animal; Eating; Endoplasmic Reticulum Stress; Energy Metabolism; Gammaproteobacteria; Glucagon-Like Peptide 1; Glucose; Glucose Tolerance Test; Hepatocytes; Ileum; Insulin; Insulin-Secreting Cells; Lipid Metabolism; Male; Organ Specificity; Rats; Signal Transduction | 2013 |
The glucagon-like peptide-1 receptor--or not?
Topics: Animals; Diabetes Mellitus, Type 2; Glucagon-Like Peptide 1; Glucagon-Like Peptide-1 Receptor; Humans; Hypoglycemic Agents; Receptors, Glucagon | 2013 |
The type 2 diabetes drug liraglutide reduces chronic inflammation induced by irradiation in the mouse brain.
Chronic inflammation in the brain is found in a range of neurodegenerative diseases such as Parkinson's or Alzheimer's disease. We have recently shown that analogues of the glucagon-like polypeptide 1 (GLP-1) such as liraglutide have potent neuroprotective properties in a mouse model of Alzheimer's disease. We also found a reduction of activated microglia in the brain. This finding suggests that GLP-1 analogues such as liraglutide have anti-inflammatory properties. To further characterise this property, we tested the effects of liraglutide on the chronic inflammation response induced by exposure of the brain to 6 Gy (X-ray). Animals were injected i.p. with 25 nmol/kg once daily for 30 days. Brains were analysed for cytokine levels, activated microglia and astrocyte levels, and nitrite levels as a measure for nitric oxide production and protein expression of iNOS. Exposure of the brain to 6 Gy induced a pronounced chronic inflammation response in the brain. The activated microglia load in the cortex and dentate gyrus region of hippocampus (P<0.001), and the activated astrocyte load in the cortex (P<0.01) was reduced by liraglutide. Furthermore, the pro-inflammatory cytokine levels of IL-6 (P<0.01), IL-12p70 (P<0.01), IL-1β (P<0.05), and total nitrite concentration were reduced in the brains of animals treated with liraglutide. The results demonstrate that liraglutide is effective in reducing a number of parameters linked to the chronic inflammation response. Liraglutide or similar GLP-1 analogues may be a suitable treatment for reducing the chronic inflammatory response in the brain found in several neurodegenerative conditions. Topics: Animals; Anti-Inflammatory Agents; Astrocytes; Body Weight; Brain; Cytokines; Diabetes Mellitus, Type 2; Eating; Glucagon-Like Peptide 1; Inflammation; Liraglutide; Male; Mice; Mice, Inbred C57BL; Microglia; Nitric Oxide Synthase Type II; Nitrites; Radiation Injuries, Experimental | 2013 |
Impact of incretin on early-phase insulin secretion and glucose excursion.
This study investigated the impact of incretin on early-phase insulin secretion and glucose excursion. The normal glucose tolerance (NGT), impaired glucose tolerance (IGT), and type 2 diabetes mellitus (T2DM) groups included 16, 8, and 19 subjects, respectively. Subjects underwent continuous glucose monitoring for 3 days, followed by an oral glucose tolerance test. Plasma glucose, insulin, glucagon, total glucose-dependent insulinotropic polypeptide (GIP), and glucagon-like peptide-l (GLP-1) levels were measured at 30-min increments for 2 h after glucose intake. Differences with P < 0.05 were considered statistically significant. The area under the curve (AUC) of total GIP (120-min GIP-AUC) of the T2DM group was significantly lower than those of the NGT and IGT groups. The 120-min GLP-1-AUC of the NGT group was significantly larger than those of the T2DM and IGT groups. The early-phase insulin secretion index (ΔI30/ΔG30) of the T2DM group was significantly lower than those of the NGT and IGT groups. Mean amplitudes of glycemic excursions (MAGEs) went in the order of NGT < IGT < T2DM (P < 0.01, IGT vs. NGT; P < 0.001, T2DM vs. IGT). The 120-min GIP-AUC was negatively correlated with MAGE (r = -0.464), but uncorrelated with ΔI30/ΔG30. The 120-min GLP-1-AUC was positively correlated with ΔI30/ΔG30 (r = 0.580), but negatively correlated with MAGE (r = -0.606). Incretin may ameliorate glucose excursions, and GLP-1 may exert them by promoting early-phase insulin secretion. No correlation was observed between GIP secretion and early-phase insulin secretion. Topics: Adult; Blood Glucose; Cohort Studies; Diabetes Mellitus, Type 2; Female; Gastric Inhibitory Polypeptide; Glucagon; Glucagon-Like Peptide 1; Glucose Intolerance; Glucose Tolerance Test; Humans; Incretins; Insulin; Insulin Secretion; Male; Middle Aged | 2013 |
Exendin-4 increases bone mineral density in type 2 diabetic OLETF rats potentially through the down-regulation of SOST/sclerostin in osteocytes.
Glucagon-like peptide-1 (GLP-1) receptor participates in the control of bone resorption in GLP-1 knockout mice. Also, GLP-1 induces an insulin- and parathyroid hormone-independent osteogenic action through osteoclasts and osteoblasts in insulin-resistant and type 2 diabetic rats. Osteocytes are now considered central to bone homeostasis. A secreted product of osteocytes, sclerostin, inhibits bone formation. However, the effect of GLP-1 on osteocytes remains unclear. Therefore, we investigated the effect of GLP-1 on bone mineral density (BMD), and the cellular and molecular mechanisms associated with osteocytes.. We investigated the presence of GLP-1 receptors in osteocyte-like MLO-Y4 cells and osteocytes of rat femurs through RT-PCR, Western blot and confocal microscopy, and investigated the effect of exendin-4 on the expression of mRNA (by quantitative real-time RT-PCR) and protein (by Western blot) of SOST/sclerostin in osteocyte-like MLO-Y4 cells during culture under normal or high-glucose (30 mM) conditions, and measured circulating levels of sclerostin, osteocalcin, and tartrate-resistant alkaline phosphatase (TRAP) 5b and femoral BMD in type 2 diabetic OLETF rats treated with exendin-4.. GLP-1 receptor was present on MLO-Y4 cells and osteocytes of rat femurs. Exendin-4 reduced the mRNA expression and protein production of SOST/sclerostin under normal or high-glucose conditions in MLO-Y4 cells. Exendin-4 reduced serum levels of sclerostin, increased serum levels of osteocalcin, and increased femoral BMD in type 2 diabetic OLETF rats.. These findings suggest that exendin-4 might increase BMD by decreasing the expression of SOST/sclerostin in osteocytes in type 2 diabetes. Topics: Analysis of Variance; Animals; Blotting, Western; Bone Density; Bone Morphogenetic Proteins; Diabetes Mellitus, Type 2; Enzyme-Linked Immunosorbent Assay; Exenatide; Fluorescent Antibody Technique; Gene Expression Regulation; Genetic Markers; Glucagon-Like Peptide 1; Glucagon-Like Peptide-1 Receptor; Immunohistochemistry; Mice; Mice, Knockout; Microscopy, Confocal; Osteocalcin; Osteocytes; Peptides; Rats; Rats, Inbred OLETF; Real-Time Polymerase Chain Reaction; Receptors, Glucagon; Reverse Transcriptase Polymerase Chain Reaction; Venoms | 2013 |
GLP-1 action and glucose tolerance in subjects with remission of type 2 diabetes after gastric bypass surgery.
Glucagon like peptide-1 (GLP-1) has been suggested as a major factor for the improved glucose tolerance ensuing after Roux-en-Y gastric bypass (RYGBP) surgery. We examined the effect of blocking endogenous GLP-1 action on glucose tolerance in subjects with sustained remission of type 2 diabetes mellitus (T2DM) present before RYGBP.. Blood glucose, insulin, C-peptide, glucagon, GLP-1, and glucose-dependent insulinotropic peptide levels were measured after a meal challenge with either exendin-(9-39) (a GLP-1r antagonist) or saline infusion in eight subjects with sustained remission of T2DM after RYGBP and seven healthy controls.. Infusion of exendin-(9-39) resulted in marginal deterioration of the 2-h plasma glucose after meal intake in RYGBP subjects [saline 78.4 ± 15.1 mg/dL compared with exendin-(9-39) 116.5 ± 22.3 mg/dL; P < 0.001]. Furthermore, glucose response to meal intake was similarly enlarged in the two study groups [percent change in the area under the curve of glucose exendin-(9-39) infusion versus saline infusion: controls 10.84 ± 8.8% versus RYGBP 9.94 ± 8.4%; P = 0.884]. In the RYGBP group, the blockade of the enlarged GLP-1 response to meal intake resulted in reduced insulin (P = 0.001) and C-peptide (P < 0.001), but no change in glucagon (P = 0.258) responses.. The limited deterioration of glucose tolerance on blockade of GLP-1 action in our study suggests the resolution of T2DM after RYGBP may be explained by mechanisms beyond enhancement of GLP-1 action. Topics: C-Peptide; Diabetes Mellitus, Type 2; Female; Gastric Bypass; Gastric Inhibitory Polypeptide; Glucagon; Glucagon-Like Peptide 1; Humans; Male; Middle Aged; Peptide Fragments | 2013 |
An emerging role of glucagon-like peptide-1 in preventing advanced-glycation-end-product-mediated damages in diabetes.
Glucagon-like peptide-1 (GLP-1) is a gut hormone produced in the intestinal epithelial endocrine L cells by differential processing of the proglucagon gene. Released in response to the nutrient ingestion, GLP-1 plays an important role in maintaining glucose homeostasis. GLP-1 has been shown to regulate blood glucose levels by stimulating glucose-dependent insulin secretion and inhibiting glucagon secretion, gastric emptying, and food intake. These antidiabetic activities highlight GLP-1 as a potential therapeutic molecule in the clinical management of type 2 diabetes, (a disease characterized by progressive decline of beta-cell function and mass, increased insulin resistance, and final hyperglycemia). Since chronic hyperglycemia contributed to the acceleration of the formation of Advanced Glycation End-Products (AGEs, a heterogeneous group of compounds derived from the nonenzymatic reaction of reducing sugars with free amino groups of proteins implicated in vascular diabetic complications), the administration of GLP-1 might directly counteract diabetes pathophysiological processes (such as pancreatic β-cell dysfunction). This paper outlines evidence on the protective role of GLP-1 in preventing the deleterious effects mediated by AGEs in type 2 diabetes. Topics: Diabetes Mellitus, Type 2; Glucagon-Like Peptide 1; Glycation End Products, Advanced; Humans; Signal Transduction | 2013 |
Liraglutide effective in the severely insulin-resistant patient with type 2 diabetes requiring U-500 insulin: a case report.
We describe the effectiveness of liraglutide therapy in a severely insulin-resistant patient with type 2 diabetes mellitus (DM-2) requiring U-500 insulin.. A 65-year-old morbidly obese man (body mass index, 67.3 kg/m(2); weight, 156.2 kg) presented with a 20-year history of DM-2; the glycemic control deteriorated to U-500 insulin requirement. He was inadequately controlled (hemoglobin A1c [HbA1c], 9.1%) on metformin plus U-500 insulin titrated to 575 units daily. Liraglutide was added and titrated to 1.8 mg once daily over 3 weeks.. Insulin requirements decreased markedly (>50%) to 250 units daily after 5 months of added liraglutide, with a concurrent improvement in HbA1c from 9.1% to 6.9% and weight loss of 22.6 kg.. The addition of once-daily liraglutide to the regimen of patients with uncontrolled DM-2 requiring U-500 insulin should be considered as it may help to reduce insulin requirements, improve glycemic control, and assist with weight management. Topics: Aged; Blood Glucose; Body Mass Index; Diabetes Mellitus, Type 2; Drug Therapy, Combination; Glucagon-Like Peptide 1; Glycated Hemoglobin; Humans; Hypoglycemic Agents; Insulin; Liraglutide; Male; Obesity, Morbid; Severity of Illness Index; Treatment Outcome | 2013 |
Insulin sensitivity and secretion changes after gastric bypass in normotolerant and diabetic obese subjects.
To elucidate the mechanisms of improvement/reversal of type 2 diabetes after Roux-en-Y gastric bypass (RYGB).. Fourteen morbidly obese subjects, 7 with normal glucose tolerance and 7 with type 2 diabetes, were studied before and 1 month after RYGB by euglycemic hyperinsulinemic clamp (EHC), by intravenous glucose tolerance test (IVGTT) and by oral glucose tolerance test (OGTT) in 3 different sessions. Intravenous glucose tolerance test IVGTT and OGTT insulin secretion rate (ISR) and sensitivity were obtained by the minimal model. Glucose-dependent insulinotropic polypeptide (GIP) and glucagon-like peptide-1 (GLP-1) were measured. Six healthy volunteers were used as controls.. Total ISR largely increased in diabetic subjects only when glucose was administered orally (37.8 ± 14.9 vs 68.3 ± 22.8 nmol; P < 0.05, preoperatively vs postoperatively). The first-phase insulin secretion was restored in type 2 diabetic after the IVGTT (Φ1 × 10: 104 ± 54 vs 228 ± 88; P < 0.05, preoperatively vs postoperatively; 242 ± 99 in controls). Insulin sensitivity by EHC (M × 10) was slightly but significantly improved in both normotolerant and diabetic subjects (1.46 ± 0.22 vs 1.37 ± 0.55 mmol·min·kg; P < 0.05 and 1.53 ± 0.23 vs 1.28 ± 0.62 mmol·min·kg; P < 0.05, respectively). Quantitative insulin sensitivity check index was improved in all normotolerant (0.32 ± 0.02 vs 0.30 ± 0.02; P < 0.05) and diabetic subjects (0.33 ± 0.03 vs 0.31 ± 0.02; P < 0.05). GIP and GLP-1 levels increased both at fast and after OGTT mainly in type 2 diabetic subjects.. The large increase of ISR response to the OGTT together with the restoration of the first-phase insulin secretion in diabetic subjects might explain the reversal of type 2 diabetes after RYGB. The large incretin secretion after the oral glucose load might contribute to the increased ISR. Topics: Adult; Blood Glucose; Diabetes Mellitus, Type 2; Female; Gastric Bypass; Glucagon-Like Peptide 1; Glucose Tolerance Test; Humans; Insulin; Insulin Resistance; Insulin Secretion; Male; Obesity, Morbid; Treatment Outcome | 2013 |
GLP-1 analogues as a new treatment option for hypothalamic obesity in adults: report of nine cases.
Patients with hypothalamic pathology often develop morbid obesity, causing severe metabolic alterations resulting in increased morbidity and mortality. Glucagon-like peptide-1 (GLP-1) analogues improve glycaemic control in type 2 diabetic patients and cause weight loss in obese patients by yet unknown mechanisms. Here we tested whether GLP-1 analogues were also effective in the treatment of obesity and associated metabolic alterations in patients with hypothalamic disease.. Nine patients (eight with type 2 diabetes mellitus) with moderate to severe hypothalamic obesity were treated with GLP-1 analogues for up to 51 months. Body weight, homeostasis model assessment - insulin resistance (HOMA-IR), HbA1c and lipids were assessed.. Eight patients experienced substantial weight loss (-13.1±5.1 kg (range -9 to -22)). Insulin resistance (HOMA-IR -3.2±3.5 (range -9.1 to 0.8)) and HbA1c values (-1.3±1.4% (range -4.5 to 0.0)) improved under treatment (24.3±18.9 months (range 6 to 51)). Five patients reported increased satiation in response to the treatment. Two of the eight patients complained about nausea and vomiting and one of them abandoned therapy because of sustained gastrointestinal discomfort after 6 months. One patient suffered from intolerable nausea and vomiting and discontinued treatment within 2 weeks.. GLP-1 analogues can cause substantial and sustained weight loss in obese patients with hypothalamic disease. This offers a new approach for medical treatment of moderate to severe hypothalamic obesity and associated metabolic alterations. Topics: Adolescent; Adult; Blood Glucose; Craniopharyngioma; Diabetes Mellitus, Type 2; Exenatide; Glucagon-Like Peptide 1; Humans; Hypoglycemic Agents; Hypothalamic Diseases; Insulin Resistance; Liraglutide; Male; Middle Aged; Obesity; Peptides; Pituitary Neoplasms; Venoms | 2013 |
Glucagon-like peptide-1 and diabetes 2012.
Topics: Animals; Diabetes Mellitus, Type 2; Glucagon-Like Peptide 1; Glucagon-Like Peptide-1 Receptor; Humans; Hypoglycemic Agents; Incretins; Receptors, Glucagon; Signal Transduction | 2012 |
Characterization of beta cell and incretin function in patients with MODY1 (HNF4A MODY) and MODY3 (HNF1A MODY) in a Swedish patient collection.
The aim of this study was to evaluate the beta cell and incretin function in patients with HNF4A and HNF1A MODY during a test meal. Clinical characteristics and biochemical data (glucose, proinsulin, insulin, C-peptide, GLP-1 and GIP) during a test meal were compared between MODY patients from eight different families. BMI-matched T2D and healthy subjects were used as two separate control groups. The early phase of insulin secretion was attenuated in HNF4A, HNF1A MODY and T2D (AUC0-30 controls: 558.2 ± 101.2, HNF4A MODY: 93.8 ± 57.0, HNF1A MODY: 170.2 ± 64.5, T2D: 211.2 ± 65.3, P < 0.01). Markedly reduced levels of proinsulin were found in HNF4A MODY compared to T2D and that tended to be so also in HNF1A MODY (HNF4A MODY: 3.7 ± 1.2, HNF1A MODY: 8.3 ± 3.8 vs. T2D: 26.6 ± 14.3). Patients with HNF4A MODY had similar total GLP-1 and GIP responses as controls (GLP-1 AUC: (control: 823.9 ± 703.8, T2D: 556.4 ± 698.2, HNF4A MODY: 1,257.0 ± 999.3, HNF1A MODY: 697.1 ± 818.4) but with a different secretion pattern. The AUC insulin during the test meal was strongly correlated with the GIP secretion (Correlation coefficient 1.0, P < 0.001). No such correlation was seen for insulin and GLP-1. Patients with HNF4A and HNF1A MODY showed an attenuated early phase of insulin secretion similar to T2Ds. AUC insulin during the test meal was strongly correlated with GIP secretion, whereas no such correlation was seen for insulin and GLP-1. Thus, GIP may be a more important factor for insulin secretion than GLP-1 in MODY patients. Topics: Adult; Aged; Case-Control Studies; Diabetes Mellitus, Type 2; Female; Gastric Inhibitory Polypeptide; Glucagon-Like Peptide 1; Hepatocyte Nuclear Factor 1-alpha; Hepatocyte Nuclear Factor 4; Humans; Incretins; Insulin-Secreting Cells; Male; Middle Aged; Proinsulin; Sweden | 2012 |
Cost-utility analysis of liraglutide compared with sulphonylurea or sitagliptin, all as add-on to metformin monotherapy in Type 2 diabetes mellitus.
To investigate the cost-effectiveness of liraglutide as add-on to metformin vs. glimepiride or sitagliptin in patients with Type 2 diabetes uncontrolled with first-line metformin.. Data were sourced from a clinical trial comparing liraglutide vs. glimepiride, both in combination with metformin, and a clinical trial comparing liraglutide vs. sitagliptin, both as add-on to metformin. Only the subgroup of patients in whom liraglutide was added to metformin monotherapy was included in the cost-utility analysis. The CORE Diabetes Model was used to simulate outcomes and costs with liraglutide 1.2 and 1.8 mg vs. glimepiride and vs. sitagliptin over patients' lifetimes. Treatment effects were taken directly from the trials. Costs and outcomes were discounted at 3.5% per annum and costs were accounted from a third-party payer (UK National Health System) perspective.. Treatment with liraglutide 1.2 and 1.8 mg resulted, respectively, in mean increases in quality-adjusted life expectancy of 0.32 ± 0.15 and 0.28 ± 0.14 quality-adjusted life years vs. glimepiride, and 0.19 ± 0.15 and 0.31 ± 0.15 quality-adjusted life years vs. sitagliptin, and was associated with higher costs of £ 3003 ± £ 678 and £ 4688 ± £ 639 vs. glimepiride, and £ 1842 ± £ 751 and £ 3224 ± £ 683 vs. sitagliptin, over a patient's lifetime. Both liraglutide doses were cost-effective, with incremental cost-effectiveness ratios of £ 9449 and £ 16,501 per quality-adjusted life year gained vs. glimepiride, and £ 9851 and £ 10,465 per quality-adjusted life year gained vs. sitagliptin, respectively.. Liraglutide, added to metformin monotherapy, is a cost-effective option for the treatment of Type 2 diabetes in a UK setting. Topics: Adolescent; Adult; Aged; Aged, 80 and over; Body Mass Index; Cost-Benefit Analysis; Diabetes Mellitus, Type 2; Female; Glucagon-Like Peptide 1; Humans; Hypoglycemic Agents; Liraglutide; Male; Metformin; Middle Aged; Pyrazines; Quality-Adjusted Life Years; Sitagliptin Phosphate; Sulfonylurea Compounds; Treatment Outcome; Triazoles; United Kingdom; Young Adult | 2012 |
Inhibition of apical sodium-dependent bile acid transporter as a novel treatment for diabetes.
Bile acids are recognized as metabolic modulators. The present study was aimed at evaluating the effects of a potent Asbt inhibitor (264W94), which blocks intestinal absorption of bile acids, on glucose homeostasis in Zucker Diabetic Fatty (ZDF) rats. Oral administration of 264W94 for two wk increased fecal bile acid concentrations and elevated non-fasting plasma total Glp-1. Treatment of 264W94 significantly decreased HbA1c and glucose, and prevented the drop of insulin levels typical of ZDF rats in a dose-dependent manner. An oral glucose tolerance test revealed up to two-fold increase in plasma total Glp-1 and three-fold increase in insulin in 264W94 treated ZDF rats at doses sufficient to achieve glycemic control. Tissue mRNA analysis indicated a decrease in farnesoid X receptor (Fxr) activation in small intestines and the liver but co-administration of a Fxr agonist (GW4064) did not attenuate 264W94 induced glucose lowering effects. In summary, our results demonstrate that inhibition of Asbt increases bile acids in the distal intestine, promotes Glp-1 release and may offer a new therapeutic strategy for type 2 diabetes mellitus. Topics: Animals; Bile Acids and Salts; Diabetes Mellitus, Type 2; Dose-Response Relationship, Drug; Feces; Gastrointestinal Agents; Gene Expression Regulation; Glucagon-Like Peptide 1; Hypoglycemic Agents; Intestinal Absorption; Intestine, Small; Isoxazoles; Liver; Male; Organic Anion Transporters, Sodium-Dependent; Random Allocation; Rats; Rats, Zucker; Receptors, Cytoplasmic and Nuclear; RNA, Messenger; Symporters; Thiazepines | 2012 |
Glucokinase activation repairs defective bioenergetics of islets of Langerhans isolated from type 2 diabetics.
It was reported previously that isolated human islets from individuals with type 2 diabetes mellitus (T2DM) show reduced glucose-stimulated insulin release. To assess the possibility that impaired bioenergetics may contribute to this defect, glucose-stimulated respiration (Vo(2)), glucose usage and oxidation, intracellular Ca(2+), and insulin secretion (IS) were measured in pancreatic islets isolated from three healthy and three type 2 diabetic organ donors. Isolated mouse and rat islets were studied for comparison. Islets were exposed to a "staircase" glucose stimulus, whereas IR and Vo(2) were measured. Vo(2) of human islets from normals and diabetics increased sigmoidally from equal baselines of 0.25 nmol/100 islets/min as a function of glucose concentration. Maximal Vo(2) of normal islets at 24 mM glucose was 0.40 ± 0.02 nmol·min(-1)·100 islets(-1), and the glucose S(0.5) was 4.39 ± 0.10 mM. The glucose stimulation of respiration of islets from diabetics was lower, V(max) of 0.32 ± 0.01 nmol·min(-1)·100 islets(-1), and the S(0.5) shifted to 5.43 ± 0.13 mM. Glucose-stimulated IS and the rise of intracellular Ca(2+) were also reduced in diabetic islets. A clinically effective glucokinase activator normalized the defective Vo(2), IR, and free calcium responses during glucose stimulation in islets from type 2 diabetics. The body of data shows that there is a clear relationship between the pancreatic islet energy (ATP) production rate and IS. This relationship was similar for normal human, mouse, and rat islets and the data for all species fitted a single sigmoidal curve. The shared threshold rate for IS was ∼13 pmol·min(-1)·islet(-1). Exendin-4, a GLP-1 analog, shifted the ATP production-IS curve to the left and greatly potentiated IS with an ATP production rate threshold of ∼10 pmol·min(-1)·islet(-1). Our data suggest that impaired β-cell bioenergetics resulting in greatly reduced ATP production is critical in the molecular pathogenesis of type 2 diabetes mellitus. Topics: Adult; Animals; Benzeneacetamides; Calcium Signaling; Cell Respiration; Diabetes Mellitus, Type 2; Enzyme Activators; Exenatide; Female; Glucagon-Like Peptide 1; Glucokinase; Glucose; Glycolysis; Humans; Hypoglycemic Agents; Insulin; Insulin Secretion; Islets of Langerhans; Male; Mice; Middle Aged; Oxidative Phosphorylation; Peptides; Rats; Species Specificity; Tissue Culture Techniques; Venoms | 2012 |
Insulin avoidance and treatment outcomes among patients with a professional driving licence starting glucagon-like peptide 1 (GLP-1) agonists in the Association of British Clinical Diabetologists (ABCD) nationwide exenatide and liraglutide audits.
Topics: Automobile Driving; Blood Glucose; Device Approval; Diabetes Mellitus, Type 1; Diabetes Mellitus, Type 2; Dose-Response Relationship, Drug; Exenatide; Female; Glucagon-Like Peptide 1; Humans; Hypoglycemia; Hypoglycemic Agents; Licensure; Liraglutide; Male; Middle Aged; Peptides; United Kingdom; Venoms | 2012 |
Gastric bypass surgery restores meal stimulation of the anorexigenic gut hormones glucagon-like peptide-1 and peptide YY independently of caloric restriction.
The effects of gastric bypass surgery on the secretion of the anorexigenic gut-derived hormones glucagon-like peptide-1 (GLP-1) and peptide YY (PYY), independent of caloric restriction and due to different dietary macronutrients, is not well characterized. This study examines the effects of a mixed-nutrient or high-fat liquid meal on the postprandial stimulation of GLP-1 and PYY following gastric bypass or equivalent hypocaloric diet.. Total PYY and active GLP-1 were measured fasting and at multiple points after standardized mixed-nutrient and high-fat liquid meals in two matched groups of obese subjects. The meal stimulation tests were performed before and 14.6 ± 3.3 days after gastric bypass (GBP, n = 10) and before and after a 7-day hypocaloric liquid diet matching the post-GBP diet (control, n = 10).. Mixed-nutrient and high-fat postprandial GLP-1 levels increased following GBP (mixed-nutrient peak: 85.0 ± 28.6-323 ± 51 pg/ml, P < 0.01; high-fat peak: 81.8 ± 9.6-278 ± 49 pg/ml, P < 0.01), but not after diet (mixed-nutrient peak: 104.4 ± 9.4-114.9 ± 15.8 pg/ml, P = NS; high-fat peak: 118.1 ± 16.4-104.4 ± 10.8 pg/ml, P = NS). The postprandial PYY response also increased after GBP but not diet, though the increase in peak PYY did not reach statistical significance (GBP mixed-nutrient peak: 134.8 ± 26.0-220.7 ± 52.9 pg/ml, P = 0.09; GBP high-fat peak: 142.1 ± 34.6-197.9 ± 12.7 pg/ml, P = 0.07; diet mixed-nutrient peak: 99.8 ± 8.0-101.1 ± 13.3 pg/ml, P = NS; diet high-fat peak: 105.0 ± 8.8-103.1 ± 11.8 pg/ml, P = NS). The postprandial GLP-1 response was not affected by the macronutrient content of the meal. However, following GBP the mixed-nutrient PYY total area under the curve (AUC(0-120)) was significantly greater than the high-fat PYY AUC(0-120) (22,081 ± 5,662 pg/ml min vs. 18,711 ± 1,811 pg/ml min, P = 0.04).. Following GBP there is an increase in the postprandial stimulation of PYY and GLP-1 that is independent of caloric restriction. The phenomenon of "bariatric surgery-induced anorexia" may be linked to the increased levels after GBP. Topics: Adolescent; Adult; Aged; Appetite; Body Mass Index; Caloric Restriction; Case-Control Studies; Diabetes Mellitus, Type 2; Diet, High-Fat; Fasting; Female; Food; Gastric Bypass; Glucagon-Like Peptide 1; Humans; Male; Middle Aged; Obesity, Morbid; Peptide YY; Postprandial Period; Prospective Studies; Weight Loss; Young Adult | 2012 |
Voluntary running exercise prevents β-cell failure in susceptible islets of the Zucker diabetic fatty rat.
Physical activity improves glycemic control in type 2 diabetes (T2D), but its contribution to preserving β-cell function is uncertain. We evaluated the role of physical activity on β-cell secretory function and glycerolipid/fatty acid (GL/FA) cycling in male Zucker diabetic fatty (ZDF) rats. Six-week-old ZDF rats engaged in voluntary running for 6 wk (ZDF-A). Inactive Zucker lean and ZDF (ZDF-I) rats served as controls. ZDF-I rats displayed progressive hyperglycemia with β-cell failure evidenced by falling insulinemia and reduced insulin secretion to oral glucose. Isolated ZDF-I rat islets showed reduced glucose-stimulated insulin secretion expressed per islet and per islet protein. They were also characterized by loss of the glucose regulation of fatty acid oxidation and GL/FA cycling, reduced mRNA expression of key β-cell genes, and severe reduction of insulin stores. Physical activity prevented diabetes in ZDF rats through sustaining β-cell compensation to insulin resistance shown in vivo and in vitro. Surprisingly, ZDF-A islets had persistent defects in fatty acid oxidation, GL/FA cycling, and β-cell gene expression. ZDF-A islets, however, had preserved islet insulin mRNA and insulin stores compared with ZDF-I rats. Physical activity did not prevent hyperphagia, dyslipidemia, or obesity in ZDF rats. In conclusion, islets of ZDF rats have a susceptibility to failure that is possibly due to altered β-cell fatty acid metabolism. Depletion of pancreatic islet insulin stores is a major contributor to islet failure in this T2D model, preventable by physical activity. Topics: Adrenocorticotropic Hormone; Animals; Body Weight; Diabetes Mellitus, Type 2; Dyslipidemias; Eating; Fatty Acids; Glucagon-Like Peptide 1; Insulin; Insulin Resistance; Insulin-Secreting Cells; Male; Muscle, Skeletal; Physical Conditioning, Animal; Rats; Rats, Zucker | 2012 |
Normalizing action of exendin-4 and GLP-1 in the glucose metabolism of extrapancreatic tissues in insulin-resistant and type 2 diabetic states.
Exendin-4 (Ex-4) mimics glucagon-like peptide-1 (GLP-1 or GCG as listed in the HUGO database), being anti-diabetic and anorectic, in stimulating glucose and lipid metabolism in extrapancreatic tissues. We studied the characteristics of Ex-4 and GLP-1 action, during prolonged treatment, on GLUTs expression (mRNA and protein), glycogen content (GC), glucose transport (GT), glycogen synthase a (GSa), and kinase (PI3K and MAPKs) activity, in liver, muscle, and fat of insulin-resistant (IR, by fructose) and type 2 diabetic (T2D, streptozotocin at birth) rats compared with normal rats. In both IR and T2D, the three tissues studied presented alterations in all measured parameters. In liver, GLP-1 and also Ex-4 normalized the lower than normal Glut2 (Slc2a2) expression and showed a trend to normalize the reduced GC in IR, and GLP-1, like Ex-4, also in T2D, effects mediated by PI3K and MAPKs. In skeletal muscle, neither GLP-1 nor Ex-4 modified Glut4 (Slc2a4) expression in either experimental model but showed normalization of reduced GT and GSa, in parallel with the normalization of reduced PI3K activity in T2D and MAPKs in both models. In adipose tissue, the altered GLUT4 expression in IR and T2D, along with reduced GT in IR and increased GT in T2D, and with hyperactivated PI3K in both, became normal after GLP-1 and Ex-4 treatment; yet, MAPKs, that were also higher, became normal only after Ex-4 treatment. The data shows that Ex-4, as well as GLP-1, exerts a normalizing effect on IR and T2D states through a distinct post-receptor mechanism, the liver being the main target for Ex-4 and GLP-1 to control glucose homeostasis. Topics: Adipose Tissue; Animals; Biological Transport; Blood Glucose; Diabetes Mellitus, Experimental; Diabetes Mellitus, Type 2; Exenatide; Glucagon; Glucagon-Like Peptide 1; Glucose; Glucose Transporter Type 2; Glucose Transporter Type 4; Glycogen Synthase; Insulin Resistance; Liver; Male; Mitogen-Activated Protein Kinases; Muscle, Skeletal; Peptides; Phosphatidylinositol 3-Kinases; Rats; Rats, Wistar; Venoms | 2012 |
Chitosan-based therapeutic nanoparticles for combination gene therapy and gene silencing of in vitro cell lines relevant to type 2 diabetes.
Glucagon like peptide 1 (GLP-1), a blood glucose homeostasis modulating incretin, has been proposed for the treatment of type 2 diabetes mellitus (T2DM). However, native GLP-1 pharmacokinetics reveals low bioavailability due to degradation by the ubiquitous dipeptydil peptidase IV (DPP-IV) endoprotease. In this study, the glucosamine-based polymer chitosan was used as a cationic polymer-based in vitro delivery system for GLP-1, DPP-IV resistant GLP-1 analogues and siRNA targeting DPP-IV mRNA. We found chitosans to form spherical nanocomplexes with these nucleic acids, generating two distinct non-overlapping size ranges of 141-283 nm and 68-129 nm for plasmid and siRNA, respectively. The low molecular weight high DDA chitosan 92-10-5 (degree of deacetylation, molecular weight and N:P ratio (DDA-Mn-N:P)) showed the highest plasmid DNA transfection efficiency in HepG2 and Caco-2 cell lines when compared to 80-10-10 and 80-80-5 chitosans. Recombinant native GLP-1 protein levels in media of transfected cells reached 23 ng/L while our DPP-IV resistant analogues resulted in a fivefold increase of GLP-1 protein levels (115 ng/L) relative to native GLP-1, and equivalent to the Lipofectamine positive control. We also found that all chitosan-DPP-IV siRNA nanocomplexes were capable of DPP-IV silencing, with 92-10-5 being significantly more effective in abrogating enzymatic activity of DPP-IV in media of silenced cells, and with no apparent cytotoxicity. These results indicate that specific chitosan formulations may be effectively used for the delivery of plasmid DNA and siRNA in a combination therapy of type 2 diabetes. Topics: Acetylation; Caco-2 Cells; Chemical Phenomena; Chitosan; Diabetes Mellitus, Type 2; Dipeptidyl Peptidase 4; Dipeptidyl-Peptidase IV Inhibitors; Gene Silencing; Gene Transfer Techniques; Genetic Therapy; Glucagon-Like Peptide 1; Hep G2 Cells; HT29 Cells; Humans; Molecular Weight; Nanoparticles; Particle Size; Recombinant Fusion Proteins; Recombinant Proteins; RNA, Small Interfering | 2012 |
Glucagon-like peptide 1 receptor plays a critical role in geniposide-regulated insulin secretion in INS-1 cells.
To explore the role of the glucagon-like peptide 1 receptor (GLP-1R) in geniposide regulated insulin secretion in rat INS-1 insulinoma cells.. Rat INS-1 insulinoma cells were cultured. The content of insulin in the culture medium was measured with ELISA assay. GLP-1R gene in INS-1 cells was knocked down with shRNA interference. The level of GLP-1R protein in INS-1 cells was measured with Western blotting.. Geniposide (0.01-100 μmol/L) increased insulin secretion from INS-1 cells in a concentration-dependent manner. Geniposide (10 μmol/L) enhanced acute insulin secretion in response to both the low (5.5 mmol/L) and moderately high levels (11 mmol/L) of glucose. Blockade of GLP-1R with the GLP-1R antagonist exendin (9-39) (200 nmol/L) or knock-down of GLP-1R with shRNA interference in INS-1 cells decreased the effect of geniposide (10 μmol/L) on insulin secretion stimulated by glucose (5.5 mmol/L).. Geniposide increases insulin secretion through glucagon-like peptide 1 receptors in rat INS-1 insulinoma cells. Topics: Animals; Cell Line, Tumor; Diabetes Mellitus, Type 2; Gardenia; Glucagon-Like Peptide 1; Insulin; Iridoids; Islets of Langerhans; Plant Extracts; Rats; RNA Interference; RNA, Small Interfering | 2012 |
Magnitude and variability of the glucagon-like peptide-1 response in patients with type 2 diabetes up to 2 years following gastric bypass surgery.
To characterize the magnitude and variance of the change of glucose and glucagon-like peptide-1 (GLP-1) concentrations, and to identify determinants of glucose control up to 2 years after gastric bypass (GBP).. Glucose and GLP-1 concentrations were measured during an oral glucose challenge before and 1, 12, and 24 months after GBP in 15 severely obese patients with type 2 diabetes.. Glucose area under the curve from 0 to 180 min (AUC(0-180)) started decreasing in magnitude (P < 0.05) 1 month after surgery. GLP-1 AUC(0-180) increased in magnitude 1 month after GBP (P < 0.05), with increased variance only after 1 year (P(σ)(2) ≤ 0.001). GLP-1 AUC(0-180) was positively associated with insulin AUC(0-180) (P = 0.025).. The increase in variance of GLP-1 at 1 and 2 years after GBP suggests mechanisms other than proximal gut bypass to explain the enhancement of GLP-1 secretion. The association between GLP-1 and insulin concentrations supports the idea that the incretins are involved in glucose control after GBP. Topics: Area Under Curve; Blood Glucose; Diabetes Mellitus, Type 2; Female; Follow-Up Studies; Gastric Bypass; Glucagon-Like Peptide 1; Glucose Tolerance Test; Humans; Incretins; Male; Middle Aged; Obesity | 2012 |
Impaired incretin effect and fasting hyperglucagonaemia characterizing type 2 diabetic subjects are early signs of dysmetabolism in obesity.
People with type 2 diabetes mellitus (T2DM) are characterized by reduced incretin effect and inappropriate glucagon levels. We evaluated α and β-cell responses to oral glucose tolerance test (OGTT) and isoglycaemic intravenous glucose infusion (IIGI) in lean and obese persons with T2DM or normal glucose tolerance (NGT) to elucidate the impact of obesity on the incretin effect and incretin hormone and glucagon responses.. Four hour 50-g OGTT and IIGI were performed in (i) Eight obese patients with T2DM [mean body mass index (BMI): 37 (range: 35-41) kg/m(2)]; (ii) Eight obese subjects with NGT [BMI: 33 (35-38) kg/m(2)]; (iii) Eight lean patients with T2DM [BMI: 24 (22-25) kg/m(2)]; and (iv) Eight lean healthy subjects [BMI: 23 (20-25) kg/m(2)].. The incretin effect was significantly (p < 0.05) reduced in patients with T2DM {obese: 7 ± 7% [mean ± standard error of the mean (SEM)]; lean: 29 ± 8%; p = 0.06)} and was lower in obese subjects (41 ± 4%) than in lean subjects with NGT (53 ± 4%; p < 0.05). Obese subjects with NGT were also characterized by elevated fasting plasma glucagon levels, but the inappropriate glucagon responses to OGTT found in the T2DM patients were not evident in these subjects.. Our findings suggest that reduced incretin effect and fasting hyperglucagonaemia constitute very early steps in the pathophysiology of T2DM detectable even in obese people who despite their insulin-resistant state have NGT. Topics: Adult; Aged; Aged, 80 and over; Biomarkers; Blood Glucose; Body Mass Index; C-Peptide; Diabetes Mellitus, Type 2; Fasting; Female; Glucagon; Glucagon-Like Peptide 1; Glucose; Glucose Tolerance Test; Humans; Incretins; Insulin; Insulin-Secreting Cells; Male; Middle Aged; Obesity | 2012 |
[The new antidiabetic agents in the firing line.... safety reasons or witch hunt?].
Topics: Animals; Breast Neoplasms; Calcitonin; Carcinoma, Medullary; Clinical Trials as Topic; Comorbidity; Diabetes Mellitus, Type 2; Dipeptidyl Peptidase 4; Disease Susceptibility; Female; Glucagon-Like Peptide 1; Humans; Hypoglycemic Agents; Infections; Liraglutide; Pancreatitis; Pharmacovigilance; Pioglitazone; Pyrazines; Risk Assessment; Safety-Based Drug Withdrawals; Sitagliptin Phosphate; Species Specificity; Thiazolidinediones; Thyroid Neoplasms; Triazoles; Urinary Bladder Neoplasms | 2012 |
Regulation of adipocyte formation by GLP-1/GLP-1R signaling.
Increased nutrient intake leads to excessive adipose tissue accumulation, obesity, and the development of associated metabolic disorders. How the intestine signals to adipose tissue to adapt to increased nutrient intake, however, is still not completely understood. We show here, that the gut peptide GLP-1 or its long-lasting analog liraglutide, function as intestinally derived signals to induce adipocyte formation, both in vitro and in vivo. GLP-1 and liraglutide activate the GLP-1R, thereby promoting pre-adipocyte proliferation and inhibition of apoptosis. This is achieved at least partly through activation of ERK, PKC, and AKT signaling pathways. In contrast, loss of GLP-1R expression causes reduction in adipogenesis, through induction of apoptosis in pre-adipocytes, by inhibition of the above mentioned pathways. Because GLP-1 and liraglutide are used for the treatment of type 2 diabetes, these findings implicate GLP-1 as a regulator of adipogenesis, which could be an alternate pathway leading to improved lipid homeostasis and controlled downstream insulin signaling. Topics: 3T3-L1 Cells; Adipocytes; Adipogenesis; Animals; Cell Differentiation; Cell Division; Diabetes Mellitus, Type 2; Gene Knockdown Techniques; Glucagon-Like Peptide 1; Glucagon-Like Peptide-1 Receptor; Intestinal Mucosa; Liraglutide; Male; Mice; Mice, Inbred C57BL; Obesity; Protein Kinase C; Receptors, Glucagon; Signal Transduction | 2012 |
Comparison of metabolic effects of surgical-induced massive weight loss in patients with long-term remission versus non-remission of type 2 diabetes.
The aim of this study was to evaluate the pathophysiological mechanisms underlying the non-remission of type 2 diabetes in Roux-en-Y gastric bypass (RYGB) patients.. A group of patients not in remission (NR) was formed (n = 13). A remission group (R) was composed of patients who had undergone normalization of fasting glycemia and A1c, without anti-diabetic drugs and matched for selected baseline characteristics (i.e., duration of disease, previous BMI, final BMI, fat distribution, and age; n = 15). A control group of lean subjects (n = 41) was formed.. The NR group had higher uric acid (5.1 vs. 3.9 mg/dL), number of leukocytes (6,866.9 vs. 5,423.6), hs-CRP (0.27 vs. 0.12 mg/dL), MCP-1 (118.4 vs. 64.4 ng/mL), HOMA-IR, and AUC(glucose) but lower adiponectin (9.4 vs. 15.4 ng/mL), leptin (12.7 vs. 20.7 ng/mL), and AUC(GLP-1) in comparison to R group; the NR group also had lower leptin and higher adiponectin, HOMA-IR, AUC(glucose), AUC(C-peptide), AUC(glucagon), and AUC(GLP-1) than controls. The R group had lower MCP-1 and higher adiponectin compared to controls. Insulin sensitivity was significantly lower in the NR group than in the R and control groups. The insulin secretion index values were lower in the NR group than in the R and control groups.. This study found greater insulin resistance, lower insulin secretion, persistent adiposopathy and chronic subclinical inflammation, and less robust incretin response in the NR group despite a similar level of weight loss. Persistently altered pathophysiological mechanisms can be related to the lack of remission of type 2 diabetes after RYGB. Topics: Adiponectin; Adolescent; Adult; Area Under Curve; Blood Glucose; Body Mass Index; Brazil; C-Reactive Protein; Diabetes Mellitus, Type 2; Female; Gastric Bypass; Glucagon-Like Peptide 1; Humans; Incretins; Leukocytes; Male; Middle Aged; Obesity, Morbid; Remission Induction; Retrospective Studies; Uric Acid; Weight Loss; Young Adult | 2012 |
Myocardial insulin signaling and glucose transport are up-regulated in Goto-Kakizaki type 2 diabetic rats after ileal transposition.
Ileal transposition (IT) as one of the effective treatments for non-obese type 2 diabetes mellitus has been widely investigated. However, the mechanisms underlying profound improvements in glucose homeostasis are still uncertain. Our objective was to explore the myocardial insulin signal transduction and glucose disposal in non-obese type 2 diabetes mellitus rats after IT surgery.. Adult male Goto-Kakizaki (GK) rats or Sprague-Dawley (SD) rats were randomly assigned to diabetic IT, diabetic sham-IT, and non-diabetic control SD groups. Food intake, body weight, fasting plasma glucose, insulin tolerance, and serum glucagon-like peptide-1 (GLP-1) were measured. Subsequently, the myocardial glucose uptake and the protein levels of insulin receptor-beta (IR-β), phosphorylated IR-β, insulin receptor substrate 1 (IRS-1), phosphorylated IRS-1, and IRS-1-associated phosphatidylinositol-3 kinase (PI3K) from myocardial cell lysates were evaluated. We also assessed the expression of glucose transporter 4 (GLUT4) in both skeletal muscle and myocardial cell lysates.. Compared to sham operations within 6 months, IT surgery for GK rats did (1) result in less food intake and reduced body weight gain over time, (2) improve plasma glucose homeostasis with increased serum GLP-1 secretion and myocardial glucose uptake, (3) increase protein expression of insulin signaling pathway, including IR-β, IRS-1 and their phosphorylation levels, and IRS-1-associated PI3K in the myocardium, and (4) enhance the protein levels of membrane GLUT4 in skeletal muscle and myocardium.. IT surgery ameliorates glucose disorder in GK type 2 diabetic rats. Meanwhile, IT surgery is effective in up-regulating both myocardial insulin signaling and glucose disposal within 6 months. Topics: Animals; Biological Transport; Diabetes Mellitus, Experimental; Diabetes Mellitus, Type 2; Glucagon-Like Peptide 1; Glucose; Glucose Transporter Type 4; Ileum; Insulin; Insulin Receptor Substrate Proteins; Male; Muscle, Skeletal; Myocardium; Rats; Rats, Inbred Strains; Rats, Sprague-Dawley; Signal Transduction; Up-Regulation | 2012 |
Combination therapy with liraglutide and sulfonylurea for a type 2 diabetic patient with high titer of anti-insulin antibodies produced by insulin therapy.
Topics: Aged; Diabetes Mellitus, Type 2; Drug Therapy, Combination; Glucagon-Like Peptide 1; Humans; Hypoglycemic Agents; Incretins; Insulin Antibodies; Liraglutide; Male; Sulfonylurea Compounds; Treatment Outcome | 2012 |
Essay for the 2011 CIHR/CMAJ award: glucagon-like peptides for metabolic and gastrointestinal disorders.
Topics: Animals; Awards and Prizes; Diabetes Mellitus, Type 2; Dipeptidyl Peptidase 4; Dipeptidyl-Peptidase IV Inhibitors; Gastrointestinal Diseases; Glucagon-Like Peptide 1; Glucagon-Like Peptide-1 Receptor; Glucagon-Like Peptides; Humans; Metabolic Diseases; Receptors, Glucagon | 2012 |
The combination of colesevelam with sitagliptin enhances glycemic control in diabetic ZDF rat model.
Bile acid sequestrants have been shown to reduce glucose levels in patients with type 2 diabetes. We previously reported that the bile acid sequestrant colesevelam HCl (Welchol) (COL) induced the release of glucagon-like peptide (GLP)-1 and improved glycemic control in insulin-resistant rats. In the present study, we tested whether adding sitagliptin (Januvia) (SIT), which prolongs bioactive GLP-1 half life, to COL would further enhance glycemic control. Male Zucker diabetic fatty (ZDF) rats were assigned to four groups: diabetic model without treatment (the model), the model treated with 2% COL or 0.4% (120 mg/day) SIT alone, or with the combination (COL+SIT). After 4 wk of treatment, the glucose area under the curve (AUC) was reduced more in the COL+SIT than the COL although both groups showed decreased glucose AUC with increased AUC of bioactive GLP-1 (GLP-1A) compared with the model group. The above changes were not observed after 8 wk. Increasing the SIT dose by 50% (180 mg SIT/day) in the diet reduced the glucose AUC in the COL+SIT group even after 8 wk but still not in the SIT alone group compared with the model. It was noteworthy that, after 8 wk, insulin levels in the SIT group declined to levels similar to the model. Histological examination of the pancreatic β-cell islets showed that islet sizes were larger, proliferation enhanced, and cell apoptosis reduced in the COL+SIT but not the SIT alone group compared with the model. We hypothesize that the combination of COL with SIT extends the half life of COL-induced GLP-1A and benefits preservation of the islets that delay the development of diabetes and improve glycemic control. This study suggests that the combined therapy (COL+SIT) is more effective than either drug alone for reducing glucose levels in diabetes. Topics: Allylamine; Animals; Anticholesteremic Agents; Apoptosis; Bile Acids and Salts; Blood Glucose; Body Weight; Cell Proliferation; Cell Size; Colesevelam Hydrochloride; Diabetes Mellitus, Type 2; Diet; Drug Synergism; Fluorescent Antibody Technique; Glucagon-Like Peptide 1; Glucose Tolerance Test; Hypoglycemic Agents; In Situ Nick-End Labeling; Insulin; Insulin-Secreting Cells; Ki-67 Antigen; Male; Postprandial Period; Pyrazines; Rats; Rats, Zucker; Receptors, G-Protein-Coupled; RNA, Messenger; Sitagliptin Phosphate; Triazoles | 2012 |
Formation of cyclic structure at amino-terminus of glucagon-like peptide-1 exhibited a prolonged half-life in vivo.
The multiple physiological characterizations of glucagon-like peptide-1 (GLP-1) make it a promising drug candidate for the therapy of type 2 diabetes. However, the biological half-life of GLP-1 is short in vivo due to degradation by dipeptidyl peptidase-IV (DPP-IV) and renal clearance. The stabilization of GLP-1 is critical for its utility in drug development. In this study, several GLP-1 mutants containing an N-terminal cyclic conformation were prepared in that the existence of cyclic conformation is predicted to increase the stabilization of GLP-1 in vivo. In this study, the binding capacities of the mutants were determined, the stabilities of the mutants were investigated and the physiological functions of the mutants were compared with those of wild-type GLP-1 in animals. The results indicated that the mutant (GLP1N8) remarkably raised the half-life in vivo; it also showed better glucose tolerance and higher HbA(1c) reduction than GLP-1 and exendin-4 in rodents. These results suggest that the GLP-1 analog (GLP1N8) which contains an N-terminal cyclic structure might be utilized as possible potent anti-diabetic drugs in the treatment of type 2 diabetes mellitus. Topics: Animals; Blood Glucose; Diabetes Mellitus, Experimental; Diabetes Mellitus, Type 2; Dipeptidyl Peptidase 4; Drug Design; Glucagon-Like Peptide 1; Glucose Tolerance Test; Glycated Hemoglobin; Half-Life; Hypoglycemic Agents; Injections, Subcutaneous; Male; Rats | 2012 |
Effects of duodenal-jejunal exclusion on beta cell function and hormonal regulation in Goto-Kakizaki rats.
The aim of our work was to investigate the hormones that control glycemic status and in vitro β-cell function in diabetes mellitus after a duodenal-jejunal exclusion in Goto-Kakizaki rats (Taconic, Denmark).. Twenty-three rats (age, 12-14 wk) were randomized as follows: group 1 (n = 14), no intervention (control); or group 2 (n = 9), duodenal-jejunal exclusion.. In group 2, levels of glucagon and leptin were lower than in group 1 at 1 week and at 8 weeks. Glucagon-like peptide 1 levels had a significant increase at 8 weeks from basal value in group 2 and this value was higher than in group 1. The insulin secretion at 60 minutes in group 2 was higher than in group 1 (group 1, 12.9 ± 12.0 μg/L vs group 2, 41.9 ± 36.3 μg/L; P < .05). Messenger RNA (mRNA) expression of insulin at 2 months was higher in the rat pancreas of the experimental group than in the control group (group 1, .99 ± .48 mRNA amount vs group 2, 1.66 ± .33 mRNA amount; P < .05).. Gastrojejunal bypass in this model improves glucose ratios, with a significant increase of glucagon-like peptide 1 and decrease of homeostasis model assessment, glucagon, and leptin levels after surgery. This type of surgery improves mRNA insulin expression in pancreatic islets and insulin secretion as well. Topics: Animals; Diabetes Mellitus, Type 2; Gastric Bypass; Glucagon; Glucagon-Like Peptide 1; Homeostasis; Insulin; Insulin-Secreting Cells; Leptin; Male; Models, Animal; Pancreas; Random Allocation; Rats; Reverse Transcriptase Polymerase Chain Reaction; RNA, Messenger | 2012 |
Liraglutide-associated acute pancreatitis.
A case of acute pancreatitis associated with liraglutide is reported.. A 53-year-old African-American man (height, 185.4 cm; weight, 108.6 kg) with type 2 diabetes mellitus arrived at the emergency department (ED) with new-onset intolerable abdominal pain in the right upper quadrant and left upper quadrant that had appeared suddenly and lasted two to three hours. He had nausea but no vomiting, with tenderness in the epigastric region. In the ED, his serum amylase concentration was found to be extremely elevated (3,963 units/L), as was his serum lipase concentration (>15,000 units/L). In addition to type 2 diabetes, his medical history included hyperlipidemia, hypertension, peripheral neuropathy, erectile dysfunction, and obesity. His home medications included aspirin 81 mg orally daily, metformin 1000 mg orally every morning and 1500 mg every evening, simvastatin 80 mg orally daily at bedtime, tadalafil 20 mg orally as needed, glimepiride 4 mg orally twice daily, and liraglutide 1.2 mg subcutaneously daily. Two months before his arrival to the ED, the patient's dosage of liraglutide was increased from 0.6 to 1.2 mg subcutaneously daily. Radiographic data were obtained, and acute pancreatitis was diagnosed. Liraglutide was discontinued indefinitely after ruling out elevated triglycerides as the cause of pancreatitis. The patient was initiated on standard therapy for acute pancreatitis and discharged eight days later with complete resolution of symptoms and normal laboratory test values.. A 53-year-old man with type 2 diabetes mellitus developed a probable case of liraglutide-induced acute pancreatitis after receiving the drug for approximately two months. Topics: Acute Disease; Amylases; Diabetes Mellitus, Type 2; Emergency Service, Hospital; Glucagon-Like Peptide 1; Humans; Hypoglycemic Agents; Lipase; Liraglutide; Male; Middle Aged; Pancreatitis | 2012 |
Fasting and oral glucose-stimulated levels of glucose-dependent insulinotropic polypeptide (GIP) and glucagon-like peptide-1 (GLP-1) are highly familial traits.
Heritability estimates have shown a varying degree of genetic contribution to traits related to type 2 diabetes. Therefore, the objective of this study was to investigate the familiality of fasting and stimulated measures of plasma glucose, serum insulin, serum C-peptide, plasma glucose-dependent insulinotropic polypeptide (GIP) and plasma glucagon-like peptide-1 (GLP-1) among non-diabetic relatives of Danish type 2 diabetic patients.. Sixty-one families comprising 193 non-diabetic offspring, 29 non-diabetic spouses, 72 non-diabetic relatives (parent, sibling, etc.) and two non-related relatives underwent a 4 h 75 g OGTT with measurements of plasma glucose, serum insulin, serum C-peptide, plasma GIP and plasma GLP-1 levels at 18 time points. Insulin secretion rates (ISR) and beta cell responses to glucose, GIP and GLP-1 were calculated. Familiality was estimated based on OGTT-derived measures.. A high level of familiality was observed during the OGTT for plasma levels of GIP and GLP-1, with peak familiality values of 74 ± 16% and 65 ± 15%, respectively (h (2) ± SE). Familiality values were lower for plasma glucose, serum insulin and serum C-peptide during the OGTT (range 8-48%, 14-44% and 15-61%, respectively). ISR presented the highest familiality value at fasting reaching 59 ± 16%. Beta cell responsiveness to glucose, GLP-1 and GIP also revealed a strong genetic influence, with peak familiality estimates of 62 ± 13%, 76 ± 15% and 70 ± 14%, respectively.. Our results suggest that circulating levels of GIP and GLP-1 as well as beta cell response to these incretins are highly familial compared with more commonly investigated measures of glucose homeostasis such as fasting and stimulated plasma glucose, serum insulin and serum C-peptide. Topics: Adult; Aged; Aged, 80 and over; Blood Glucose; C-Peptide; Denmark; Diabetes Mellitus, Type 2; Fasting; Female; Gastric Inhibitory Polypeptide; Glucagon-Like Peptide 1; Glucose Tolerance Test; Humans; Insulin; Insulin Secretion; Insulin-Secreting Cells; Male; Middle Aged | 2012 |
Partial small bowel resection with sleeve gastrectomy increases adiponectin levels and improves glucose homeostasis in obese rodents with type 2 diabetes.
The aim of this study was to examine the effect of small bowel resection with and without sleeve gastrectomy on glucose homeostasis in an obese rodent model of type 2 diabetes.. Zucker diabetic fatty rats were randomized into three surgical groups: Sham, small bowel resection, and small bowel resection with sleeve gastrectomy (BRSG). Weight and fasting glucose levels were measured at randomization and monitored after surgery. Oral glucose tolerance testing was performed at baseline and 45 days after surgery to assess glucose homeostasis and peptide changes.. At baseline, all animals exhibited impaired glucose tolerance and showed no difference in weight or fasting (area under the curve) AUC(glucose). At sacrifice, Sham animals weighed more than BRSG animals (p = 0.047). At day 45, the Sham group experienced a significant increase in AUC(glucose) compared to baseline (p = 0.02), whereas there was no difference in AUC(glucose) in either surgical group at any time point: BR (p = 0.58) and BRSG (p = 0.56). Single-factor ANOVA showed a significant difference in AUC(glucose) of p = 0.004 between groups postoperatively: Sham (50,745 ± 11,170) versus BR (23,865 ± 432.6) (p = 0.01); Sham versus BRSG (28,710 ± 3188.8) (p = 0.02). There was no difference in plasma insulin, GLP-1, or adiponectin levels before surgery, although 45 days following surgery adiponectin levels where higher in the BRSG group (p = 0.004).. Partial small bowel resection improved glucose tolerance independent of weight. The combination of small bowel resection and sleeve gastrectomy leads to an increase in adiponectin levels, which may contribute to improved glucose homeostasis. Topics: Adiponectin; Animals; Biomarkers; Blood Glucose; Diabetes Mellitus, Type 2; Gastrectomy; Glucagon-Like Peptide 1; Glucose Tolerance Test; Homeostasis; Insulin; Intestine, Small; Male; Obesity; Random Allocation; Rats; Rats, Zucker; Treatment Outcome; Weight Loss | 2012 |
Reply to: Ahren B et al. Mechanisms of action of the dipeptidyl peptidase-4 inhibitor vildagliptin in humans. Diabetes Obes Metab 2011; 13(9): 775-783 and Ahren B et al. Clinical evidence and mechanistic basis for vildagliptin's action when added to metfo
Topics: Adamantane; Diabetes Mellitus, Type 2; Dipeptidyl Peptidase 4; Dipeptidyl-Peptidase IV Inhibitors; Glucagon-Like Peptide 1; Humans; Hypoglycemic Agents; Metformin; Nitriles; Pyrrolidines | 2012 |
Current challenges in type 2 diabetes.
Topics: Diabetes Mellitus, Type 2; Female; Glucagon-Like Peptide 1; Humans; Hypoglycemia; Hypoglycemic Agents; Incretins; Insulin; Liraglutide; Male; Obesity; Prevalence | 2012 |
The difference of glucostatic parameters according to the remission of diabetes after Roux-en-Y gastric bypass.
Gut hormones play a role in diabetes remission after a Roux-en-Y gastric bypass (RYGB). Our aim was to investigate differences in gut hormone secretion according to diabetes remission after surgery. Second, we aimed to identify differences in insulin secretion and sensitivity according to diabetes remission after RYGB.. Twenty-two severely obese patients with type 2 diabetes underwent RYGB. A meal tolerance test (MTT) was performed 12 months after RYGB. The secretions of active glucagon-like peptide-1 (active GLP-1), glucose-dependent insulinotropic peptide (GIP), peptide YY, C-peptide and insulin during the MTT test were calculated using total area under the curve values (AUC). Remission was defined as glycated haemoglobin (A(1C)) of <6.5% and a fasting glucose concentration of <126 mg/dL for 1 year or more without active pharmacological therapy.. Of the 22 patients, 16 (73%) had diabetes remission (remission group). The secretion CURVES of active GLP-1, GIP and peptide YY were not different between the groups. AUC of insulin and C-peptide were also not different. Homeostasis model assessment estimate of insulin resistance was significantly lower (1.26 ± 1.05 versus 2.37 ± 1.08, p = 0.006), and Matsuda index of insulin sensitivity was significantly higher in the remission group (10.5 ± 6.2 versus 5.8 ± 2.1, p = 0.039). The disposition index (functional reserve of beta cells) was significantly higher in the remission group compared with that in the non-remission group (5.34 ± 2.74 versus 1.83 ± 0.70, p < 0.001).. Remission of diabetes after RYGB is not associated with a difference in gut hormone secretion. Patients remaining diabetic had higher insulin resistance and decreased β cell functional reserve. Topics: Adult; Blood Glucose; C-Peptide; Case-Control Studies; Diabetes Complications; Diabetes Mellitus, Type 2; Female; Gastric Bypass; Glucagon-Like Peptide 1; Glucose Tolerance Test; Humans; Hyperinsulinism; Insulin; Insulin Resistance; Insulin-Secreting Cells; Male; Middle Aged; Obesity; Prognosis; Prospective Studies; Remission Induction; Young Adult | 2012 |
GLP1-derived nonapeptide GLP1(28-36)amide protects pancreatic β-cells from glucolipotoxicity.
Type 2 diabetes, often associated with obesity, results from a deficiency of insulin production and action manifested in increased blood levels of glucose and lipids that further promote insulin resistance and impair insulin secretion. Glucolipotoxicity caused by elevated plasma glucose and lipid levels is a major cause of impaired glucose-stimulated insulin secretion from pancreatic β-cells, due to increased oxidative stress, and insulin resistance. Glucagon-like peptide-1 (GLP1), an insulinotropic glucoincretin hormone, is known to promote β-cell survival via its actions on its G-protein-coupled receptor on β-cells. Here, we report that a nonapeptide, GLP1(28-36)amide, derived from the C-terminal domain of the insulinotropic GLP1, exerts cytoprotective actions on INS-1 β-cells and on dispersed human islet cells in vitro in conditions of glucolipotoxicity and increased oxidative stress independently of the GLP1 receptor. The nonapeptide appears to enter preferably stressed, glucolipotoxic cells compared with normal unstressed cells. It targets mitochondria and improves impaired mitochondrial membrane potential, increases cellular ATP levels, inhibits cytochrome c release, caspase activation, and apoptosis, and enhances the viability and survival of INS-1 β-cells. We propose that GLP1(28-36)amide might be useful in alleviating β-cell stress and might improve β-cell functions and survival. Topics: Adenosine Triphosphate; Apoptosis; Cell Survival; Cells, Cultured; Diabetes Mellitus, Type 2; Exenatide; Glucagon-Like Peptide 1; Glucagon-Like Peptide-1 Receptor; Glucose; Humans; Hydrogen Peroxide; Insulin; Insulin Secretion; Insulin-Secreting Cells; Membrane Potential, Mitochondrial; Oleic Acid; Oxidative Stress; Peptide Fragments; Peptides; Receptors, Glucagon; tert-Butylhydroperoxide; Venoms | 2012 |
GLP-1 response to a mixed meal: what happens 10 years after Roux-en-Y gastric bypass (RYGB)?
Oral meal consumption increases glucagon-like peptide 1 (GLP-1) release which maintains euglycemia by increasing insulin secretion. This effect is exaggerated during short-term follow-up of Roux-en-y gastric bypass (RYGB). We examined the durability of this effect in patient with type 2 diabetes (T2DM) >10 years after RYGB.. GLP-1 response to a mixed meal in the 10-year post-RYGB group (n = 5) was compared to lean (n = 9), obese (n = 6), and type 2 diabetic (n = 10) controls using a cross-sectional study design. Analysis of variance (ANOVA) was used to evaluate GLP-1 response to mixed meal consumption from 0 to 300 min, 0-20 min, 20-60 min, and 60-300 min, respectively. Weight, insulin resistance, and T2DM were also assessed.. GLP-1 response 0-300 min in the 10-year post-RYGB showed a statistically significant overall difference (p = 0.01) compared to controls. Furthermore, GLP-1 response 0-20 min in the 10-year post-RYGB group showed a very rapid statistically significant rise (p = 0.035) to a peak of 40 pM. GLP-1 response between 20 and 60 min showed a rapid statistically significant (p = 0.041) decline in GLP-1 response from ~40 pM to 10 pM. GLP-1 response in the 10-year post-RYGB group from 60 to 300 min showed no statistically significant difference from controls. BMI, HOMA, and fasting serum glucose before and >10 years after RYGB changed from 59.9 → 40.4, 8.7 → 0.88, and 155.2 → 87.6 mg/dl, respectively, and were statistically significant (p < 0.05).. An exaggerated GLP-1 response was noted 10 years after RYGB, strongly suggesting a durability of this effect. This phenomenon may play a key role in maintaining type 2 diabetes remission and weight loss after RYGB. Topics: Analysis of Variance; Blood Glucose; Body Weight; Cohort Studies; Cross-Sectional Studies; Diabetes Mellitus, Type 2; Eating; Female; Follow-Up Studies; Gastric Bypass; Glucagon-Like Peptide 1; Glycated Hemoglobin; Humans; Insulin Resistance; Male; Middle Aged; Obesity, Morbid; Time Factors; Treatment Outcome; Weight Loss | 2012 |
Exenatide BID and liraglutide QD treatment patterns among type 2 diabetes patients in Germany.
This study evaluated patient and prescriber characteristics, treatment patterns, average daily dose (ADD), and glycemic control of patients initiating glucagon-like peptide 1 (GLP-1) receptor agonists in Germany.. The LifeLink™ EMR-EU database was searched to identify patients initiating exenatide twice daily (BID) or liraglutide once daily (QD) during the index period (January 1, 2009-April 4, 2010). Eligible patients had ≥ 180 days pre-index history, ≥ 90 days post-index follow-up, and a pre-index type 2 diabetes diagnosis. Univariate tests were conducted at α=0.05.. Six hundred and ninety-two patients were included (exenatide BID 292, liraglutide QD 400): mean (SD) age 59 (10) years, 59% male. Diabetologists prescribed liraglutide QD to a larger share of patients (65% vs 35% exenatide BID) than non-diabetologists (51% vs 49%). GLP-1 receptor agonist choice was not associated with age (p=0.282), gender (p=0.960), number of pre-index glucose-lowering medications (2.0 [0.9], p=0.159), pre-index HbA1c (8.2 [1.5%], p=0.231) or Charlson Comorbidity Index score (0.45 [0.78], p=0.547). Mean (SD) ADD was 16.7 mcg (9.2, label range 10-20 mcg) for exenatide BID and 1.4 mg (0.7, label range 0.6-1.8 mg) for liraglutide QD. Among patients with post-index HbA1c tests, mean unadjusted values did not differ between cohorts. Exenatide BID patients were more likely than liraglutide QD patients to continue pre-index glucose-lowering medications (67.1% vs 60.3%, p=0.027) or to start concomitant glucose-lowering medications at index (32.2% vs 25.0%, p=0.013); exenatide BID patients were less likely to augment treatment with another drug post-index (15.8% vs 22.5%, p=0.027).. Results may not be generalizable. Lab measures for clinical outcomes were available only for a sub-set of patients.. Results suggested that some differences exist between patients initiating exenatide BID or liraglutide QD, with respect to prescribing physician specialty and pre- and post-index treatment patterns. Both GLP-1 receptor agonists showed comparable post-index HbA1c values in a sub-set of patients. Topics: Adolescent; Adult; Aged; Databases, Factual; Diabetes Mellitus, Type 2; Exenatide; Female; Germany; Glucagon-Like Peptide 1; Humans; Hypoglycemic Agents; Incretins; Liraglutide; Male; Middle Aged; Outcome Assessment, Health Care; Peptides; Practice Patterns, Physicians'; Venoms; Young Adult | 2012 |
The diabetologist/cardiologist debate: a meeting of the minds.
Topics: Aged; Blood Glucose; Cardiovascular Diseases; Clinical Trials as Topic; Diabetes Mellitus, Type 2; Glucagon-Like Peptide 1; Humans; Hypoglycemic Agents; Insulin Glargine; Insulin, Long-Acting; Metformin; Practice Guidelines as Topic; Precision Medicine | 2012 |
Diabetes-associated common genetic variation and its association with GLP-1 concentrations and response to exogenous GLP-1.
The mechanisms by which common genetic variation predisposes to type 2 diabetes remain unclear. The disease-associated variants in TCF7L2 (rs7903146) and WFS1 (rs10010131) have been shown to affect response to exogenous glucagon-like peptide 1 (GLP-1), while variants in KCNQ1 (rs151290, rs2237892, and rs2237895) alter endogenous GLP-1 secretion. We set out to validate these observations using a model of GLP-1-induced insulin secretion. We studied healthy individuals using a hyperglycemic clamp and GLP-1 infusion. In addition, we measured active and total GLP-1 in response to an oral challenge in nondiabetic subjects. After genotyping the relevant single nucleotide polymorphisms, generalized linear regression models and repeated-measures ANCOVA models incorporating potential confounders, such as age and BMI, were used to assess the associations, if any, of response with genotype. These variants did not alter GLP-1 concentrations in response to oral intake. No effects on β-cell responsiveness to hyperglycemia and GLP-1 infusion were apparent. Diabetes-associated variation (T allele at rs7903146) in TCF7L2 may impair the ability of hyperglycemia to suppress glucagon (45 ± 2 vs. 47 ± 2 vs. 60 ± 5 ng/L for CC, CT, and TT, respectively, P = 0.02). In nondiabetic subjects, diabetes-associated genetic variation does not alter GLP-1 concentrations after an oral challenge or its effect on insulin secretion. Topics: C-Peptide; Diabetes Mellitus, Type 2; Genetic Predisposition to Disease; Genetic Variation; Genotype; Glucagon; Glucagon-Like Peptide 1; Glucose; Glucose Clamp Technique; Humans; Hyperglycemia; Insulin; Insulin-Secreting Cells; KCNQ1 Potassium Channel; Membrane Proteins; Transcription Factor 7-Like 2 Protein | 2012 |
The synergistic effect of valsartan and LAF237 [(S)-1-[(3-hydroxy-1-adamantyl)ammo]acetyl-2-cyanopyrrolidine] on vascular oxidative stress and inflammation in type 2 diabetic mice.
To investigate the combination effects and mechanisms of valsartan (angiotensin II type 1 receptor blocker) and LAF237 (DPP-IV inhibitor) on prevention against oxidative stress and inflammation injury in db/db mice aorta.. Db/db mice (n = 40) were randomized to receive valsartan, LAF237, valsartan plus LAF237, or saline. Oxidative stress and inflammatory reaction in diabetic mice aorta were examined.. Valsartan or LAF237 pretreatment significantly increased plasma GLP-1 expression, reduced apoptosis of endothelial cells isolated from diabetic mice aorta. The expression of NAD(P)H oxidase subunits also significantly decreased resulting in decreased superoxide production and ICAM-1 (fold change: valsartan : 7.5 ± 0.7, P < 0.05; LAF237: 10.2 ± 1.7, P < 0.05), VCAM-1 (fold change: valsartan : 5.2 ± 1.2, P < 0.05; LAF237: 4.8 ± 0.6, P < 0.05), and MCP-1 (fold change: valsartan: 3.2 ± 0.6, LAF237: 4.7 ± 0.8; P < 0.05) expression. Moreover, the combination treatment with valsartan and LAF237 resulted in a more significant increase of GLP-1 expression. The decrease of the vascular oxidative stress and inflammation reaction was also higher than monotherapy with valsartan or LAF237.. These data indicated that combination treatment with LAF237 and valsartan acts in a synergistic manner on vascular oxidative stress and inflammation in type 2 diabetic mice. Topics: Adamantane; Angiotensin II Type 1 Receptor Blockers; Animals; Aorta; Apoptosis; Blood Glucose; Diabetes Mellitus, Type 2; Drug Synergism; Endothelial Cells; Endothelium, Vascular; Glucagon-Like Peptide 1; Glucagon-Like Peptide-1 Receptor; Hypoglycemic Agents; Inflammation; Intercellular Adhesion Molecule-1; Mice; NADPH Oxidases; Oxidative Stress; Pyrrolidines; Receptors, Glucagon; Tetrazoles; Valine; Valsartan; Vascular Cell Adhesion Molecule-1 | 2012 |
Effects of chronic treatment with metformin on dipeptidyl peptidase-4 activity, glucagon-like peptide 1 and ghrelin in obese patients with Type 2 diabetes mellitus.
Studies investigating the acute effects of metformin have demonstrated actions on the incretin system and appetite regulatory hormones. There are limited data to support that these effects are sustained in the long term. We therefore studied the effects of chronic treatment with metformin on endogenous glucagon-like peptide 1, dipeptidyl peptidase-4 activity and active ghrelin (an orexigenic hormone) in obese patients with Type 2 diabetes mellitus.. Eight subjects [six male, age 58.7 ± 2.6 years, BMI 41.1 ± 2.9 kg/m(2) , HbA(1c) 69 ± 6 mmol/mol (8.5 ± 0.5%), mean ± sem] with drug-naïve Type 2 diabetes were studied for 6 h following a standard mixed meal, before and after at least 3 months of metformin monotherapy (mean dose 1.75 g daily).. The area under the curve (AUC(0-6 h) ) for active glucagon-like peptide 1 was significantly higher on metformin (pre-metformin 1750.8 ± 640 pmol l(-1) min(-1) vs. post-metformin 2718.8 ± 1182.3 pmol l(-1) min(-1) ; P=0.01). The areas under the curves for dipeptidyl peptidase-4 activity and ghrelin were not significantly different pre- and post-treatment with metformin.. Three months or more of metformin monotherapy in obese patients with Type 2 diabetes was associated with increased postprandial active glucagon-like peptide 1 levels. The effects of metformin on the enteroinsular axis may represent yet another important mechanism underlying its glucose-lowering effects. Topics: Area Under Curve; Diabetes Mellitus, Type 2; Dipeptidyl Peptidase 4; Female; Ghrelin; Glucagon-Like Peptide 1; Humans; Hypoglycemic Agents; Male; Metformin; Middle Aged; Obesity; Postprandial Period; Prospective Studies | 2012 |
Oral salmon calcitonin attenuates hyperglycaemia and preserves pancreatic beta-cell area and function in Zucker diabetic fatty rats.
Oral salmon calcitonin (sCT), a dual-action amylin and calcitonin receptor agonist, improved glucose homeostasis in diet-induced obese rats. Here, we have evaluated the anti-diabetic efficacy of oral sCT using parameters of glycaemic control and beta-cell morphology in male Zucker diabetic fatty (ZDF) rats, a model of type 2 diabetes.. Male ZDF rats were treated with oral sCT (0.5, 1.0 or 2 mg·kg(-1) ) or oral vehicle twice daily from age 8 to 18 weeks. Zucker lean rats served as control group. Fasting and non-fasted blood glucose, glycosylated haemoglobin (HbA1c) and levels of pancreas and incretin hormones were determined. Oral glucose tolerance test and i.p. glucose tolerance test were compared, and beta-cell area and function were evaluated.. Oral sCT treatment dose-dependently attenuated fasting and non-fasted hyperglycaemia during the intervention period. At the end of the study period, oral sCT treatment by dose decreased diabetic hyperglycaemia by ∼9 mM and reduced HbA1c levels by 1.7%. Furthermore, a pronounced reduction in glucose excursions was dose-dependently observed for oral sCT treatment during oral glucose tolerance test. In addition, oral sCT treatment sustained hyperinsulinaemia and attenuated hyperglucagonaemia and hypersecretion of total glucagon-like peptide-1 predominantly in the basal state. Lastly, oral sCT treatment dose-dependently improved pancreatic beta-cell function and beta-cell area at study end.. Oral sCT attenuated diabetic hyperglycaemia in male ZDF rats by improving postprandial glycaemic control, exerting an insulinotropic and glucagonostatic action in the basal state and by preserving pancreatic beta-cell function and beta-cell area. Topics: Administration, Oral; Animals; Blood Glucose; Calcitonin; Diabetes Mellitus, Type 2; Gastric Inhibitory Polypeptide; Glucagon-Like Peptide 1; Glucose Tolerance Test; Glycated Hemoglobin; Hyperglycemia; Hypoglycemic Agents; Insulin-Secreting Cells; Male; Rats; Rats, Zucker | 2012 |
Liraglutide treatment in a patient with HIV and uncontrolled insulin-treated type 2 diabetes.
Topics: Diabetes Mellitus, Type 2; Glucagon-Like Peptide 1; HIV Infections; Humans; Insulin; Liraglutide; Male; Middle Aged | 2012 |
Discovery of a potent and selective GPR120 agonist.
GPR120 is a receptor of unsaturated long-chain fatty acids reported to mediate GLP-1 secretion, insulin sensitization, anti-inflammatory, and anti-obesity effects and is therefore emerging as a new potential target for treatment of type 2 diabetes and metabolic diseases. Further investigation is however hindered by the lack of suitable receptor modulators. Screening of FFA1 ligands provided a lead with moderate activity on GPR120 and moderate selectivity over FFA1. Optimization led to the discovery of the first potent and selective GPR120 agonist. Topics: Biphenyl Compounds; Cell Survival; Cinnamates; Diabetes Mellitus, Type 2; Glucagon-Like Peptide 1; HEK293 Cells; Humans; Magnetic Resonance Spectroscopy; Mass Spectrometry; Molecular Structure; Phenylpropionates; Receptors, G-Protein-Coupled; Structure-Activity Relationship | 2012 |
Sleeve gastrectomy with jejunal bypass for the treatment of type 2 diabetes mellitus in patients with body mass index <35 kg/m2. A cohort study.
The objective of this study was to evaluate sleeve gastrectomy with jejunal bypass (SGJB) as a surgical treatment for type 2 diabetes mellitus (T2DM) in patients with a body mass index (BMI) <35 kg/m(2). This is a prospective cohort study. Patients with T2DM and BMI <35 kg/m(2) who underwent SGJB between January 2009 and June 2011 at DIPRECA Hospital, in Santiago, and Hospital Base, Osorno, Chile were included. SGJB consists of creating a gastric tube, which preserves the pylorus, and performing a jejunoileal anastomosis 300 cm distal to the angle of Treitz. Excess weight loss (EWL) and complete or partial remission of T2DM were reported. Forty-nine patients met the inclusion criteria. The mean age was 49 years (36-62), and 53 % of patients were female. Mean preoperative BMI was 31.6 kg/m(2) (25-34.9 kg/m(2)). Operation time was 123 ± 14 min, with 94.7 % of operations performed laparoscopically. Mean postoperative hospital stay was 2 days. Mean postoperative follow-up was 12 months. Median EWL at 1, 3, 6, 12, and 18 months postoperatively was 31.9 %, 56.9 %, 76.1 %, 81.5 %, and 76.1 %, respectively. Complete T2DM remission was achieved in 81.6 % of patients (40/49) and partial remission in 18.4 % (9/49). Forty of 41 patients (97.6 %) on oral hypoglycemic agents achieved complete T2DM remission, and 100 % of insulin-dependent patients stopped using insulin but were still being treated for T2DM. One patient experienced postoperative gastrointestinal bleeding. There were no deaths. SGJB is an effective treatment for T2DM in patients with BMI <35 kg/m(2). Topics: Adult; Blood Glucose; Body Mass Index; Chile; Cohort Studies; Diabetes Mellitus, Type 2; Female; Follow-Up Studies; Gastroplasty; Glucagon-Like Peptide 1; Humans; Jejunum; Laparoscopy; Male; Middle Aged; Obesity, Morbid; Prospective Studies; Treatment Outcome; Weight Loss | 2012 |
Economic outcomes of exenatide vs liraglutide in type 2 diabetes patients in the United States: results from a retrospective claims database analysis.
The safety and efficacy of the GLP-1 receptor agonists exenatide BID (exenatide) and liraglutide for treating type 2 diabetes mellitus (T2DM) have been established in clinical trials. Effective treatments may lower overall treatment costs. This study examined cost offsets and medication adherence for exenatide vs liraglutide in a large, managed care population in the US.. This was a retrospective cohort analysis comprising adult patients with T2DM who initiated exenatide or liraglutide between 1/1/2010 and 6/30/2010 and had 6 months pre-index and post-index continuous eligibility. Patients were propensity score-matched to controls for baseline differences. Medication adherence was measured by proportion of days covered (PDC). Paired t-test and McNemar's test were used to compare outcomes.. Matched exenatide and liraglutide cohorts (n=1347 pairs) had similar average total 6-month follow-up costs ($6688 vs $7346). However, exenatide patients had significantly lower mean pharmacy costs ($2925 vs $3272, p<0.001). Among liraglutide patients, patients receiving the 1.8 mg dose had significantly higher average total costs compared to those receiving the 1.2 mg dose ($8031 vs $6536, p=0.026), with higher mean pharmacy costs in the 1.8 mg cohort ($3935 vs $3146, p<0.001). There were no significant differences in inpatient or outpatient costs or medication adherence between groups (mean PDC: exenatide 56% vs liraglutide 57%, p=0.088).. The study assumed that all information needed for case classification and matching of cohorts was present and not differential across cohorts. The study did not control for covariates that were unavailable, such as HbA1c and duration of diabetes.. Patients initiating exenatide vs liraglutide for T2DM had similar medication adherence and total healthcare costs; however, exenatide patients had significantly lower total pharmacy costs. Patients prescribed 1.8 mg liraglutide had significantly higher costs compared to those on 1.2 mg. Topics: Adolescent; Adult; Age Factors; Aged; Diabetes Complications; Diabetes Mellitus, Type 2; Exenatide; Fees, Pharmaceutical; Female; Glucagon-Like Peptide 1; Health Expenditures; Health Services; Humans; Hypoglycemic Agents; Insurance Claim Review; Liraglutide; Male; Medication Adherence; Middle Aged; Peptides; Retrospective Studies; Sex Factors; United States; Venoms; Young Adult | 2012 |
Consumer group calls for antidiabetes drug to be withdrawn.
Topics: Consumer Organizations; Diabetes Mellitus, Type 2; Glucagon-Like Peptide 1; Humans; Hypoglycemic Agents; Liraglutide; Safety-Based Drug Withdrawals; United States | 2012 |
Bariatric surgery and T2DM improvement mechanisms: a mathematical model.
Consensus exists that several bariatric surgery procedures produce a rapid improvement of glucose homeostasis in obese diabetic patients, improvement apparently uncorrelated with the degree of eventual weight loss after surgery. Several hypotheses have been suggested to account for these results: among these, the anti-incretin, the ghrelin and the lower-intestinal dumping hypotheses have been discussed in the literature. Since no clear-cut experimental results are so far available to confirm or disprove any of these hypotheses, in the present work a mathematical model of the glucose-insulin-incretin system has been built, capable of expressing these three postulated mechanisms. The model has been populated with critically evaluated parameter values from the literature, and simulations under the three scenarios have been compared.. The modeling results seem to indicate that the suppression of ghrelin release is unlikely to determine major changes in short-term glucose control. The possible existence of an anti-incretin hormone would be supported if an experimental increase of GIP concentrations were evident post-surgery. Given that, on the contrary, collected evidence suggests that GIP concentrations decrease post-surgery, the lower-intestinal dumping hypothesis would seem to describe the mechanism most likely to produce the observed normalization of Type 2 Diabetes Mellitus (T2DM) after bariatric surgery.. The proposed model can help discriminate among competing hypotheses in a context where definitive data are not available and mechanisms are still not clear. Topics: Bariatric Surgery; Diabetes Mellitus, Type 2; Dipeptidyl Peptidase 4; Gastric Inhibitory Polypeptide; Ghrelin; Glucagon-Like Peptide 1; Glucose; Humans; Incretins; Insulin; Intestines; Mathematical Concepts; Models, Biological; Obesity; Treatment Outcome | 2012 |
Early intervention with liraglutide improves glucose tolerance without affecting islet microcirculation in young Goto-Kakizaki rats.
Liraglutide, an analog of glucagon-like peptide-1 (GLP-1), is an effective anti-diabetic agent with few side effects. Since native GLP-1 exerts vascular effects, we investigated changes in pancreatic islet blood flow using a non-radioactive microsphere technique, as well as insulin concentration and glucose tolerance after 17 day treatment with liraglutide in 6-week-old Goto-Kakizaki (GK) rats. Compared to saline-treated control GK rats, liraglutide limited body weight gain, decreased glycemia, improved glucose tolerance and lowered serum insulin concentration. Neither pancreatic or islet blood flow, nor pancreatic insulin content, was affected by liraglutide treatment. We conclude that early intervention with liraglutide decreases glycemia and improves glucose tolerance, thus halting the natural progression towards diabetes, without affecting islet microcirculation or pancreatic insulin content in young female GK rats. Topics: Age Factors; Animals; Blood Glucose; Diabetes Mellitus, Type 2; Disease Progression; Early Medical Intervention; Female; Glucagon-Like Peptide 1; Glucose Tolerance Test; Hypoglycemic Agents; Insulin; Islets of Langerhans; Liraglutide; Male; Microcirculation; Microspheres; Rats; Weight Loss | 2012 |
Glucagon-like peptide 1, insulin, sensory neurons, and diabetic neuropathy.
Like insulin, glucagon-like peptide 1 (GLP-1) may have direct trophic actions on the nervous system, but its potential role in supporting diabetic sensory neurons is uncertain. We identified wide expression of GLP-1 receptors on dorsal root ganglia sensory neurons of diabetic and nondiabetic mice. Exendin-4, a GLP-1 agonist, increased neurite outgrowth of adult sensory neurons in vitro. To determine the effects ofexendin-4 in comparison with continuous low- or high-dose insulin in vivo, we evaluated parallel cohorts of type 1 (streptozotocin-induced) and type 2 (db/db) mice of 2 months' diabetes duration with established neuropathy during an additional month of treatment. High-dose insulin alone reversed hyperglycemia in type 1 diabetic mice, partly reversed thermal sensory loss, improved epidermal innervation but failed to reverse electrophysiological abnormalities. Exendin-4 improved both sensory electrophysiology and behavioral sensory loss. Low-dose insulin was ineffective. In type 2 diabetes, hyperglycemia was uncorrected, and neither insulin nor exendin-4 reversed sensory electrophysiology, sensory behavior, or loss of epidermal axons. However, exendin-4 alone improved motor electrophysiology. Receptor for advanced glycosylated end products and nuclear factor-κB neuronal expression were not significantly altered by diabetes or treatment. Taken together, these results suggest that although GLP-1 agonists and insulin alone are insufficient to reverse all features of diabetic neuropathy, in combination, they might benefit some aspects of established diabetic neuropathy. Topics: Animals; Axons; Blood Glucose; Diabetes Mellitus, Experimental; Diabetes Mellitus, Type 1; Diabetes Mellitus, Type 2; Diabetic Neuropathies; Exenatide; Glucagon-Like Peptide 1; Glucagon-Like Peptide-1 Receptor; Glycated Hemoglobin; Immunohistochemistry; Insulin; Male; Mice; Motor Neurons; Neural Conduction; Peptides; Peripheral Nerves; Rats; Rats, Sprague-Dawley; Receptors, Glucagon; Sensory Receptor Cells; Signal Transduction; Venoms | 2012 |
Update on drugs to treat diabetes.
Topics: Administration, Oral; Diabetes Mellitus, Type 1; Diabetes Mellitus, Type 2; Glucagon-Like Peptide 1; Humans; Hypoglycemic Agents; Injections; Insulin | 2012 |
HOMA-S is associated with greater HbA1c reduction with a GLP-1 analogue in patients with type 2 diabetes.
Exenatide, a glucagon-like peptide-1 (GLP-1) analogue, is an effective glucoregulator for treating overweight individuals, not at target HbA1 c. This prospective study aimed to determine whether estimates of beta cell function (HOMA-B) and insulin sensitivity (HOMA-S) predict response to Exenatide treatment.Prospective data on 43 type 2 diabetes patients were collected for up to 2.8 years in UK primary care. HOMA-B and HOMA-S were estimated prior to initiating Exenatide, with monitoring of cardio-metabolic risk factors.Mean (SD) age and BMI pre-treatment were 54.1±10.5 years and 35.7±7.5 kg/m2 respectively. HbA1c decreased (mean reduction 0.9%, p=0.04; p for trend=0.01) in 61% of patients. In univariate analyses, HOMA-S as a measure of insulin sensitivity was inversely (β=- 0.41, p 0.009) related to change in HbA1c, with no relation for HOMA-B.In a random effects regression model that included age at baseline, weight, LDL-C, HDL-C and triglycerides, change in HbA1c (β= - 0.14, p<0.001) and HDL-C (β= - 0.52, p=0.011) were independently associated with increasing insulin sensitivity (r2=0.52). Thus patients with greater measured insulin sensitivity achieved greater reduction in HbA1c independent of the factors described above.In logistic regression those in the highest tertile of log-HOMA-S were 45% more likely to have a fall in HbA1c with an odds ratio (OR) of 0.55 (95% CI 0.47-0.66) p<0.0001 (log likelihood ratio for the model χ2=71.6, p<0.0001).Patients with greater measured insulin sensitivity achieve greater reduction in HbA1c with Exenatide. Determination of insulin sensitivity may assist in guiding outcome expectation in overweight patients treated with GLP-1 analogues. Topics: Body Mass Index; Diabetes Mellitus, Type 2; Exenatide; Female; Glucagon-Like Peptide 1; Glycated Hemoglobin; Homeostasis; Humans; Hypoglycemic Agents; Insulin; Insulin Resistance; Insulin-Secreting Cells; Lipids; Male; Middle Aged; Models, Biological; Peptides; Prospective Studies; Treatment Outcome; Venoms | 2012 |
Sitagliptin reduces plaque macrophage content and stabilises arteriosclerotic lesions in Apoe (-/-) mice.
Inhibitors of dipeptidyl peptidase-IV (DPP-IV), such as sitagliptin, increase glucagon-like peptide-1 (GLP-1) concentrations and are current treatment options for patients with type 2 diabetes mellitus. As patients with diabetes exhibit a high risk of developing severe atherosclerosis, we investigated the effect of sitagliptin on atherogenesis in Apoe (-/-) mice.. Apoe (-/-) mice were fed a high-fat diet and treated with either sitagliptin or placebo for 12 weeks. Plaque size and plaque composition were analysed using Oil Red O staining and immunohistochemistry. Furthermore, in vitro experiments with the modified Boyden chamber and with gelatine zymography were performed to analyse the effects of GLP-1 on isolated human monocyte migration and metalloproteinase-9 (MMP-9) release.. Treatment of Apoe (-/-) mice with sitagliptin significantly reduced plaque macrophage infiltration (the aortic root and aortic arch both showing a 67% decrease; p < 0.05) and plaque MMP-9 levels (aortic root showing a 69% and aortic arch a 58% reduction; both p < 0.01) compared with controls. Moreover, sitagliptin significantly increased plaque collagen content more than twofold (aortic root showing an increase of 58% and aortic arch an increase of 73%; both p < 0.05) compared with controls but did not change overall lesion size (8.1 ± 3.5% vs 5.1 ± 2.5% for sitagliptin vs controls; p=NS). In vitro, pretreatment of isolated human monocytes with GLP-1 significantly decreased cell migration induced by both monocyte chemotactic protein-1 and by the protein known as regulated on activation, normal T cell expressed and secreted (RANTES) in a concentration-dependent manner. Furthermore, GLP-1 significantly decreased MMP-9 release from isolated human monocyte-derived macrophages.. Sitagliptin reduces plaque inflammation and increases plaque stability, potentially by GLP-1-mediated inhibition of chemokine-induced monocyte migration and macrophage MMP-9 release. The effects observed may provide potential mechanisms for how DPP-IV inhibitors could modulate vascular disease in high-risk patients with type 2 diabetes mellitus. Topics: Animals; Apolipoproteins E; Arteriosclerosis; Body Weight; Cells, Cultured; Diabetes Mellitus, Experimental; Diabetes Mellitus, Type 2; Dipeptidyl-Peptidase IV Inhibitors; Glucagon-Like Peptide 1; Immunohistochemistry; Lipid Metabolism; Macrophages; Male; Mice; Mice, Inbred C57BL; Pyrazines; Sitagliptin Phosphate; Triazoles | 2012 |
Non-insulin injectable treatments (glucagon-like peptide-1 and its analogs) and cardiovascular disease.
Glucagon-like peptide-1 (GLP-1) [GLP-1 (7-36)-amide] plays a fundamental role in regulating postprandial nutrient metabolism. GLP-1 acts through a G-protein-coupled receptor present on the membranes of many tissues, including myocardium and endothelium. GLP-1 is cleaved by the dipeptidyl peptidase-4 enzyme to its metabolite GLP-1 (9-36)-amide within 1-2 min of its release into the circulation. Investigations have been done in humans and in animal models to determine whether GLP-1 has effects on the myocardium. Infusions of GLP-1 increase cardiac function in ischemic and non-ischemic cardiovascular disease. In humans and animal models, constant infusions of GLP-1 decrease the size of infarction and improve myocardial function in ischemic/reperfusion injury. In cardiomyopathy and heart failure, infusions of GLP-1 improve myocardial function. These beneficial effects of GLP-1 on cardiac function are mediated by both GLP-1 receptor activation and GLP-1 receptor independent actions. Infusions of the metabolite GLP-1 (9-36)-amide improve cardiac function in experimental animals with cardiovascular disease even though the metabolite does not bind to the GLP-1 receptor. The beneficial effects of GLP-1 on the heart occur in the presence of a GLP-1 receptor antagonist and in animals devoid of GLP-1 receptors. Preliminary data in animals with available GLP-1 receptor agonists and cardiac disease suggest that exenatide has beneficial effects in porcine models of ischemic heart disease. The animal data with liraglutide are inconclusive. Clinical trials with exenatide and liraglutide show significant improvements in weight, systolic blood pressure, lipid profiles, and other cardiovascular risk factors. Whether these will decrease cardiovascular events is currently under investigation. Topics: Animals; Blood Pressure; Body Weight; Cardiovascular Diseases; Diabetes Mellitus, Type 2; Diabetic Angiopathies; Dipeptidyl Peptidase 4; Dogs; Exenatide; Female; Glucagon-Like Peptide 1; Humans; Lipids; Liraglutide; Male; Mice; Peptides; Rats; Venoms | 2012 |
Novo Nordisk's reply to call for withdrawal of liraglutide.
Topics: Diabetes Mellitus, Type 2; Glucagon-Like Peptide 1; Humans; Hypoglycemic Agents; Safety-Based Drug Withdrawals | 2012 |
Bringing liraglutide to market: a CER case study.
Faced with competition from other drugs and therapies, drug manufacturers may be able to use comparative effectiveness research (CER) to help reduce barriers to a new drug's adoption and integration into formularies. But few examples exist to show how CER can be used effectively and whether the data can make a difference.. To examine how CER can help strengthen a new drug's entry into the market and integration into formularies, and how ongoing CER might be valuable as a drug is implemented in the real world.. A roundtable of 9 representatives from health plans, including formulary decision makers, evaluated how CER in phase 3 development of a new drug can add to the drug's strength of evidence, helping decision makers understand how and where to integrate that drug into a formulary. The round table participants viewed, as a case study, the development of liraglutide, a glucagon-like peptide-1 (GLP-1) receptor agonist for adults with type 2 diabetes that was approved by the FDA in January 2010. With this drug, CER was incorporated into an extensive type 2 diabetes clinical development program, comparing how the drug worked in comparison with other established therapies. Although there are many antidiabetic drugs available for use, patients with type 2 diabetes often need additional agents. The FDA approved liraglutide with the conclusion that benefits of the drug outweighed potential risks but noted the association with pancreatitis in humans and animal data that showed rare medullary thyroid cancer associated with liraglutide. Roundtable participants agreed that while pre-launch CER can be valuable, ongoing real-world research is also important for confirming expected results, identifying additional uses and indications and managing risks. The participants also suggested opportunities for additional CER studies and made recommendations for manufacturers.. Roundtable thought leaders agreed that well-planned trial designs incorporating CER result in high-quality evidence that may provide sufficient data to support adoption of a new therapy onto the formulary. When more real-world data become available and confirm the phase 3 clinical trial results, decision makers may be able to use the results to change the drug's position and either lessen or extend its use. Topics: Clinical Trials, Phase III as Topic; Comparative Effectiveness Research; Decision Making; Diabetes Mellitus, Type 2; Drug Discovery; Drug Industry; Glucagon-Like Peptide 1; Glucagon-Like Peptide-1 Receptor; Humans; Hypoglycemic Agents; Liraglutide; Marketing; Organizational Case Studies; Receptors, Glucagon | 2012 |
The role of bile after Roux-en-Y gastric bypass in promoting weight loss and improving glycaemic control.
Gastric bypass leads to the remission of type 2 diabetes independently of weight loss. Our hypothesis is that changes in bile flow due to the altered anatomy may partly explain the metabolic outcomes of the operation. We prospectively studied 12 patients undergoing gastric bypass and six patients undergoing gastric banding over a 6-wk period. Plasma fibroblast growth factor (FGF)19, stimulated by bile acid absorption in the terminal ileum, and plasma bile acids were measured. In canine and rodent models, we investigated changes in the gut hormone response after altered bile flow. FGF19 and total plasma bile acids levels increased after gastric bypass compared with no change after gastric banding. In the canine model, both food and bile, on their own, stimulated satiety gut hormone responses. However, when combined, the response was doubled. In rats, drainage of endogenous bile into the terminal ileum was associated with an enhanced satiety gut hormone response, reduced food intake, and lower body weight. In conclusion, after gastric bypass, bile flow is altered, leading to increased plasma bile acids, FGF19, incretin. and satiety gut hormone concentrations. Elucidating the mechanism of action of gastric bypass surgery may lead to novel treatments for type 2 diabetes. Topics: Adult; Animals; Bile; Bile Acids and Salts; Blood Glucose; C-Reactive Protein; Calorimetry; Diabetes Mellitus, Type 2; Dogs; Female; Fibroblast Growth Factors; Gastric Bypass; Glucagon-Like Peptide 1; Humans; Male; Middle Aged; Peptide YY; Rats; Rats, Wistar; Weight Loss | 2012 |
[Glucagon-like peptide 1 analogues in the treatment of type 2 diabetes mellitus].
A Cochrane analysis concluded that glucagon-like peptide-1 (GLP-1) analogues were effective for the improvement of glycaemic control in patients with type 2 diabetes. What is the significance for the treatment of Danish patients with type 2 diabetes? In Denmark, two drugs exist, exenatid and liraglutid, and they both reduce HbA1c with approx. 1%. Compared with sulfonylurea and insulin, the advantage of GLP-1 analogues is not only that they rarely induce hypoglycaemia, but also that body weight is reduced. On the other hand, no long-term results exist with regard to impact on the cardiovascular system, and no complete overview of possible side effects has been presented either. Topics: Denmark; Diabetes Mellitus, Type 2; Evidence-Based Medicine; Glucagon-Like Peptide 1; Glycated Hemoglobin; Humans; Hypoglycemic Agents; Incretins | 2012 |
Rectal taurocholate increases L cell and insulin secretion, and decreases blood glucose and food intake in obese type 2 diabetic volunteers.
Glucagon-like peptide-1 (GLP-1) and peptide YY (PYY) are secreted from enteroendocrine L cells in response to numerous stimuli, including bile salts. Both have multiple effects that are potentially useful in treating diabetes and obesity. L cell number and hormone content in the intestine are highest in the rectum in humans. We investigated the effects of intrarectal sodium taurocholate on plasma GLP-1, PYY, insulin and glucose concentrations, and on food intake of a subsequent meal.. Ten obese type 2 diabetic volunteers were each studied on five separate occasions after an overnight fast and oral administration of 100 mg sitagliptin 10 h before the study. They then received an intrarectal infusion of either one of four doses of taurocholate (0.66, 2, 6.66 or 20 mmol, each in 20 ml of vehicle) or vehicle alone (1% carboxymethyl cellulose) single-blind over 1 min. Hormone and glucose measurements were made prior to, and for 1 h following, the infusion. The consumption of a previously selected favourite meal eaten to satiety was measured 75 min after the infusion.. Taurocholate dose-dependently increased GLP-1, PYY and insulin, with 20 mmol doses resulting in peak concentrations 7.2-, 4.2- and 2.6-fold higher, respectively, than those achieved with placebo (p < 0.0001 for each). Plasma glucose decreased by up to 3.8 mmol/l (p < 0.001). Energy intake was decreased dose-dependently by up to 47% (p < 0.0001). The ED(50) values for effects on integrated GLP-1, insulin, PYY, food intake and glucose-lowering responses were 8.1, 10.5, 18.5, 24.2 and 25.1 mmol, respectively.. Therapies that increase bile salts (or their mimics) in the distal bowel may be valuable in the treatment of type 2 diabetes and obesity. Topics: Adult; Blood Glucose; Body Mass Index; Cholagogues and Choleretics; Diabetes Mellitus, Type 2; Eating; Enteroendocrine Cells; Glucagon-Like Peptide 1; Humans; Insulin; Insulin Secretion; Male; Middle Aged; Obesity; Peptide YY; Rectum; Taurocholic Acid; United Arab Emirates | 2012 |
Delivery of two-step transcription amplification exendin-4 plasmid system with arginine-grafted bioreducible polymer in type 2 diabetes animal model.
Exendin-4, glucagon-like peptide 1 (GLP-1) receptor agonist, is an exocrine hormone, which has potent insulinotropic actions similar to GLP-1 such as stimulating insulin biosynthesis, facilitating glucose concentration dependent insulin secretion, slowing gastric emptying, reducing food intake and stimulating β-cell proliferation. Exendin-4, also, has a longer half-life than GLP-1, due to its resistance to degradation by dipeptidyl peptidase-IV (DPP-IV). In spite of its many advantages as a therapeutic agent for diabetes, its clinical application is still restricted. Thus, to improve the activity of exendin-4 in vivo, gene therapy system was developed as an alternative method. An exendin-4 expression system was constructed using the two-step transcription amplification (TSTA) system, which is composed of pβ-Gal4-p65 and pUAS-SP-exendin-4 with combining the advantages of signal peptide (SP) in order to facilitate its secretion in ectopic cells or tissue. Arginine-grafted cyctaminebisacrylamide-diaminohexane polymer (ABP) was used as a gene carrier. Increased expression of exendin-4, glucose dependent insulin secretion in NIT-1 insulinoma cells, and high insulin expression in the presence of DPP-IV were evaluated in vitro after delivery of ABP/TSTA-SP-exendin-4. Blood glucose levels in diabetic mice were decreased dramatically from the third day for experimental period after single intravenous administration with ABP/TSTA-SP-exendin-4. The highest insulinotropic effect of exendin-4 was also observed in the ABP/TSTA/SP-exendin-4-treated mice groups, compared with the others groups from the 3rd day after injection. TSTA exendin-4 expression system with SP and ABP polymer has a potential gene therapy for the treatment of type 2 diabetes. Topics: Animals; Arginine; Blood Glucose; Cell Line; Diabetes Mellitus, Type 2; DNA; Drug Carriers; Exenatide; Gene Expression; Genetic Therapy; Glucagon-Like Peptide 1; Humans; Hypoglycemic Agents; Insulin; Insulin-Secreting Cells; Male; Mice; Mice, Inbred C57BL; Peptides; Plasmids; Polymers; Transcription, Genetic; Venoms | 2012 |
Vertical sleeve gastrectomy improves glucose and lipid metabolism and delays diabetes onset in UCD-T2DM rats.
Vertical sleeve gastrectomy (VSG) has gained interest as a low morbidity bariatric surgery, which is effective in producing weight loss and causing type 2 diabetes resolution. However, the efficacy of VSG to prevent the onset of type 2 diabetes has not been previously investigated. VSG or sham surgery was performed on 2-month-old prediabetic male University of California Davis-type 2 diabetes mellitus rats. Sham-operated animals were either sham-operated ad libitum fed (S-AL) or were weight-matched to VSG-operated animals (S-WM). Diabetes onset was determined by weekly nonfasting blood glucose measurements. Animals underwent oral glucose tolerance tests at 1 and 4 months after surgery and indirect calorimetry at 1.5 months after surgery. VSG surgery significantly delayed diabetes onset compared with both S-AL and S-WM animals. VSG-operated animals ate 23% less and weighed 20% less than S-AL. Energy expenditure did not differ between VSG-operated animals and controls. Results from the oral glucose tolerance tests demonstrate improved glucose tolerance and islet function in VSG-operated animals compared with S-AL and S-WM. Nutrient-stimulated glucagon-like peptide (GLP)-1, GLP-2, and peptide YY excursions were greater in VSG-operated animals. VSG surgery resulted in decreased fasting plasma insulin, ghrelin and lipid concentrations, and markedly higher fasting plasma adiponectin and bile acid concentrations, independent of body weight. Increases of circulating bile acid concentrations were due to selective increases of taurine-conjugated bile acids. Thus, VSG delays type 2 diabetes onset in the University of California Davis-type 2 diabetes mellitus rat, independent of body weight. This is potentially mediated by increases of circulating bile acids, adiponectin, and nutrient-stimulated GLP-1 secretion and decreased circulating ghrelin concentrations. Topics: 3T3-L1 Cells; Animals; Blood Glucose; Body Weight; Diabetes Mellitus, Type 2; Gastrectomy; Glucagon-Like Peptide 1; Glucose Tolerance Test; Insulin; Kaplan-Meier Estimate; Lipid Metabolism; Male; Mice; Rats | 2012 |
Hormone copycats.
Topics: Diabetes Mellitus, Type 2; Exenatide; Glucagon-Like Peptide 1; Humans; Hypoglycemic Agents; Injections, Subcutaneous; Liraglutide; Peptides; Venoms | 2012 |
[Glucagon-like peptide-1 receptor agonists].
Topics: Diabetes Mellitus, Type 2; Exenatide; Glucagon-Like Peptide 1; Humans; Hypoglycemic Agents; Incretins; Peptides; Receptors, Glucagon; Venoms | 2012 |
[Therapeutic use and adverse events of incretin-related drugs].
Topics: Adamantane; Aged; Diabetes Mellitus, Type 2; Dipeptidyl-Peptidase IV Inhibitors; Exenatide; Glucagon-Like Peptide 1; Humans; Hypoglycemic Agents; Incretins; Linagliptin; Liraglutide; Nitriles; Peptides; Piperidines; Purines; Pyrazines; Pyrrolidines; Quinazolines; Sitagliptin Phosphate; Triazoles; Uracil; Venoms; Vildagliptin | 2012 |
[Prospects for incretin-related drugs].
Topics: Diabetes Mellitus, Type 2; Dipeptidyl-Peptidase IV Inhibitors; Glucagon-Like Peptide 1; Humans; Incretins; Receptors, Glucagon | 2012 |
[Perspective of new and future treatment of type 2 diabetes].
Topics: Animals; Diabetes Mellitus, Type 2; Glucagon-Like Peptide 1; Glucagon-Secreting Cells; Glucokinase; Humans; Insulin; Insulin-Secreting Cells; Metabolic Syndrome; Receptors, G-Protein-Coupled; Sodium-Glucose Transporter 2 Inhibitors | 2012 |
The glucagon-like peptide-1 analog liraglutide suppresses ghrelin and controls diabetes in a patient with Prader-Willi syndrome.
Prader-Willi syndrome (PWS) is a genetic disease characterized by severe morbid obesity in association with hyperphagia and type 2 diabetes mellitus. Liraglutide is a glucagon-like peptide (GLP)-1 analog that controls appetite, decreases body weight and improves glycemic control. However, it is unclear if PWS patients with diabetes experience similar benefits of liraglutide therapy. In a 25 year-old female hyperglycemic PWS patient, liraglutide monotherapy improved her Hemoglobin A1c remarkably (12.6% to 6.1%) while steadily decreasing her body mass index (BMI: 39.1 kg/m(2) to 35.7 kg/m(2)). We offered this patient continued liraglutide therapy for one year to determine the effect on various metabolic parameters. Her hyperphagia was controlled soon after liraglutide treatment commenced and remained so throughout the treatment. The metabolic parameters changed as follows: visceral fat area fell from 150.1 to 113.2 (cm(2)); plasma insulin rose from 108.1 to 277.0 (pmol/L); plasma active GLP-1 dropped from 2.1 to 1.2 (fmol/L); plasma active ghrelin diminished from 137.0 to 27.7 (pmol/L). While plasma active ghrelin before treatment was abnormally high, even though her GLP-1 was normal, both decreased following liraglutide therapy. These results suggest that in addition to its insulinotropic effects, other potential mechanisms activated by liraglutide therapy may reduce the plasma ghrelin levels elevated in PWS, leading to an improvement in overeating, BMI and visceral fat, as well as glycemic control. Topics: Abdominal Fat; Adult; Body Mass Index; Diabetes Mellitus, Type 2; Female; Ghrelin; Glucagon-Like Peptide 1; Glycated Hemoglobin; Humans; Hyperphagia; Liraglutide; Prader-Willi Syndrome | 2012 |
Exenatide for once-weekly administration.
▾Exenatide is a glucagon-like peptide 1 (GLP-1) agonist used in the management of people with type 2 diabetes. A twice-daily injectable formulation (▾Byetta - Eli Lilly) was licensed in 2006. ▾Bydureon (Eli Lilly) is a prolonged-release injectable formulation that allows once-weekly administration. Here we discuss the place of Bydureon in the management of type 2 diabetes mellitus. Topics: Clinical Trials as Topic; Delayed-Action Preparations; Diabetes Mellitus, Type 2; Drug Administration Schedule; Drug Costs; Exenatide; Glucagon-Like Peptide 1; Humans; Hypoglycemic Agents; Injections, Subcutaneous; Insulin; Liraglutide; Middle Aged; Peptides; Treatment Outcome; Venoms | 2012 |
The glucose-lowering effects of the PDE4 inhibitors roflumilast and roflumilast-N-oxide in db/db mice.
The cAMP-degrading phosphodiesterase 4 (PDE4) enzyme has recently been implicated in the regulation of glucagon-like peptide-1 (GLP-1), an incretin hormone with glucose-lowering properties. We investigated whether the PDE4 inhibitor roflumilast elevates GLP-1 levels in diabetic db/db mice and whether this elevation is accompanied by glucose-lowering effects.. Plasma GLP-1 was determined in db/db mice after single oral administration of roflumilast or its active metabolite roflumilast-N-oxide. Diabetes-relevant variables including HbA(1c), blood glucose, serum insulin, body weight, food and water intake, and pancreas morphology were determined in db/db mice treated daily for 28 days with roflumilast or roflumilast-N-oxide. Pharmacokinetic/pharmacodynamic analysis clarified the contribution of roflumilast vs its metabolite. In addition, the effect of roflumilast-N-oxide on insulin release was investigated in primary mouse islets.. Single treatment of db/db mice with 10 mg/kg roflumilast or roflumilast-N-oxide enhanced plasma GLP-1 2.5- and fourfold, respectively. Chronic treatment of db/db mice with roflumilast or roflumilast-N-oxide at 3 mg/kg showed prevention of disease progression. Roflumilast-N-oxide abolished the increase in blood glucose, reduced the increment in HbA(1c) by 50% and doubled fasted serum insulin compared with vehicle, concomitant with preservation of pancreatic islet morphology. Furthermore, roflumilast-N-oxide amplified forskolin-induced insulin release in primary islets. Roflumilast-N-oxide showed stronger glucose-lowering effects than its parent compound, consistent with its greater effect on GLP-1 secretion and explainable by pharmacokinetic/pharmacodynamic modelling.. Our results suggest that roflumilast and roflumilast-N-oxide delay the progression of diabetes in db/db mice through protection of pancreatic islet physiology potentially involving GLP-1 and insulin activities. Topics: Administration, Oral; Aminopyridines; Animals; Benzamides; Blood Glucose; Cyclopropanes; Diabetes Mellitus, Type 2; Disease Models, Animal; Disease Progression; Female; Glucagon-Like Peptide 1; Hypoglycemic Agents; Insulin; Mice; Mice, Mutant Strains; Phosphodiesterase 4 Inhibitors | 2012 |
Antidiabetic activities of oligosaccharides of Ophiopogonis japonicus in experimental type 2 diabetic rats.
The aim of the present study is to investigate the antidiabetic properties of oligosaccharides of Ophiopogonis japonicus (OOJ) in experimental type 2 diabetic rats. OOJ was administered orally in doses of 225 and 450 mg/kg body weight to high-fat diet and low-dose streptozotocin (STZ)-induced type 2 diabetic rats for 3 weeks. The results showed that OOJ treatment could increase body weight, decrease organ related weights of liver and kidney, reduce fasting blood glucose level, and improve oral glucose tolerance in diabetic rats. Moreover, increased glycogen content in liver and skeletal muscle, reduced urinary protein excretion, higher hepatic GCK enzyme activity, lower hepatic PEPCK enzyme activity, enhanced GLP-1 level, decreased glucagon level and alleviated histopathological changes of pancreas occurred in OOJ-treated diabetic rats by comparison with untreated diabetic rats. This study demonstrates, for the first time to our knowledge, that OOJ exerts remarkable antidiabetic effect in experimental type 2 diabetes mellitus, thus justifying its traditional usage. Topics: Animals; Blood Glucose; Body Weight; Diabetes Mellitus, Experimental; Diabetes Mellitus, Type 2; Diet, High-Fat; Fasting; Glucagon; Glucagon-Like Peptide 1; Glucose Tolerance Test; Glycogen; Hypoglycemic Agents; Liver; Male; Muscle, Skeletal; Oligosaccharides; Ophiopogon; Organ Size; Proteinuria; Rats; Rats, Sprague-Dawley | 2012 |
Insulin detemir enhances proglucagon gene expression in the intestinal L cells via stimulating β-catenin and CREB activities.
Insulin therapy using insulin detemir (d-INS) has demonstrated weight-sparing effects compared with other insulin formulations. Mechanisms underlying these effects, however, remain largely unknown. Here we postulate that the intestinal tissues' selective preference allows d-INS to exert enhanced action on proglucagon (Gcg) expression and the production of glucagon-like peptide (GLP)-1, an incretin hormone possessing both glycemia-lowering and weight loss effects. To test this hypothesis, we used obese type 2 diabetic db/db mice and conducted a 14-day intervention with daily injection of a therapeutic dose of d-INS or human insulin (h-INS) in these mice. The body weight of the mice after 14-day daily injection of d-INS (5 IU/kg) was decreased significantly compared with those injected with the same dose of h-INS or saline. The weight-sparing effect of d-INS was associated with significantly elevated circulating levels of total GLP-1 and reduced food intake. Histochemistry analysis demonstrated that d-INS induced rapid phosphorylation of protein kinase B (Akt) in the gut L cells of normal mice. Western blotting showed that d-INS stimulated Akt activation in a more rapid and enhanced fashion in the mouse distal ileum compared with those by h-INS. In vitro investigation in primary fetal rat intestinal cell (FRIC) cultures showed that d-INS increased Gcg mRNA expression as determined by Northern blotting and real-time RT-PCR. Consistent with these in vivo investigations, d-INS significantly increased GLP-1 secretion in FRIC cultures. Consistently, d-INS was also shown to induce rapid phosphorylation of Akt in the clonal gut cell line GLUTag. Furthermore, d-INS increased β-catenin phosphorylation, its nuclear translocation, and enhanced cAMP response element-binding protein (CREB) phosphorylation in a phosphatidylinositol 3-kinase and/or mitogen-activated protein kinase kinase/extracellular signal-regulated kinase-sensitive manner. We suggest that the weight-sparing benefit of d-INS in mice is related to its intestinal tissues preference that leads to profound stimulation of Gcg expression and enhanced GLP-1 secretion in intestinal L cells, potentially involving the activation of insulin/β-catenin/CREB signaling pathways. Topics: Animals; beta Catenin; Cells, Cultured; Cyclic AMP Response Element-Binding Protein; Diabetes Mellitus, Type 2; Fetus; Gene Expression Regulation; Glucagon-Like Peptide 1; Hypoglycemic Agents; Insulin Detemir; Insulin, Long-Acting; Intestinal Mucosa; L Cells; Mice; Mice, Mutant Strains; Obesity; Organ Specificity; Phosphorylation; Proglucagon; Protein Processing, Post-Translational; Rats; Rats, Wistar; RNA, Messenger | 2012 |
Effects of long-term treatment with the dipeptidyl peptidase-4 inhibitor vildagliptin on islet endocrine cells in non-obese type 2 diabetic Goto-Kakizaki rats.
Reduced β cell mass is a characteristic feature of type 2 diabetes and incretin therapy is expected to prevent this condition. However, it is unknown whether dipeptidyl peptidase-4 inhibitors influence β and α cell mass in animal models of diabetes that can be translated to humans. Therefore, we examined the long-term effects of treatment with the dipeptidyl peptidase-4 inhibitor vildagliptin on islet morphology in Goto-Kakizaki (GK) rats, a spontaneous, non-obese model of type 2 diabetes, and explored the underlying mechanisms. Four-week-old GK rats were orally administered with vildagliptin (15 mg/kg) twice daily for 18 weeks. Glucose tolerance was monitored during the study. After 18 weeks, β and α cell morphology and the expression of molecules involved in cell proliferation and cell death were examined by immunohistochemistry and morphometric analysis. We found that vildagliptin improved glucose tolerance and insulin secretion, and suppressed hyperglucagonemia by increasing plasma active glucagon-like peptide-1 concentrations. β cell mass was reduced in GK rats to 40% of that in Wistar rats, but was restored to 80% by vildagliptin. Vildagliptin enhanced β and α cell proliferation, and increased the number of small neogenetic islets. Vildagliptin also reduced the number of 8-hydroxy-2'-deoxyguanosine-positive cells and forkhead box protein O1 expression, inhibited macrophage infiltration, and enhanced S6 ribosomal protein, molecule of target of rapamycin, and pancreatic duodenal homeobox 1 expression. These results indicate that starting vildagliptin treatment from an early age improved glucose tolerance and preserved islet β cell mass in GK rats by facilitating the proliferation of islet endocrine cells. Topics: 8-Hydroxy-2'-Deoxyguanosine; Adamantane; Animals; Apoptosis; Cell Proliferation; Deoxyguanosine; Diabetes Mellitus, Type 2; Dipeptidyl Peptidase 4; Dipeptidyl-Peptidase IV Inhibitors; Eating; Glucagon; Glucagon-Like Peptide 1; Glucose Intolerance; Insulin; Insulin Secretion; Insulin-Secreting Cells; Male; Nitriles; Pyrrolidines; Rats; Time Factors; Vildagliptin | 2012 |
16,17-Dihydro-17b-hydroxy isomitraphylline alkaloid as an inhibitor of DPP-IV, and its effect on incretin hormone and β-cell proliferation in diabetic rat.
Reduces levels of intact GLP-1 and inhibition of DPPIV augments levels of intact GLP-1 improves glycemic control in type 2 diabetes patients and diabetic animal model. Although, GLP-1 is known to stimulate insulin secretion, insulin biosynthesis and dose insulin gene transcription, augmented supplies of insulin for secretion. DHIM is an indole alkaloid, isolated from Mitragyna parvifolia. In the present in vitro study, we investigated the inhibitor activity of novel alkaloid on DPP IV. DHIM produced marked inhibition of DPP IV. Accordingly, we used 5, 10 and 20 μg DHIM alkaloids in DPPIV assay, and then found 18%, 56%, and 68% inhibition activity. In the present in vivo study, we examined the 16,17-dihydro-17b-hydroxy (DHIM) effect on neonatal Wistar albino rats treated with streptozotocin, an established model of type 2 diabetes. Diabetic rats, 8 weeks chronic administered with DHIM (100mg/kg) markedly reduced plasma glucose concentration, increased glucose tolerance in response to glucose loading. Consequently, GLP-1 and IL-10 levels were also significantly increased in treated diabetic rats. Despite, body weight was not found changed significantly; the insulin content and β-cell mass at 2 months were significantly increased by DHIM. Immunostaining and Confocal image of TUNEL assay showed that DHIM stimulates β-cell proliferation and reduced pancreatic cell apoptosis in diabetic treated rats. These results suggest that DHIM induces proliferation of pancreatic cells and increases the formation of β-cells. Topics: Animals; Animals, Newborn; Blood Glucose; Cell Proliferation; Diabetes Mellitus, Experimental; Diabetes Mellitus, Type 2; Dipeptidyl-Peptidase IV Inhibitors; Glucagon-Like Peptide 1; Indole Alkaloids; Insulin; Insulin-Secreting Cells; Interleukin-10; Rats; Rats, Wistar | 2012 |
Editorial: beyond glycemic control: incretins and cardiovascular protection in diabetes.
Topics: Cardiovascular Diseases; Diabetes Mellitus, Type 2; Dipeptidyl-Peptidase IV Inhibitors; Glucagon-Like Peptide 1; Humans; Incretins | 2012 |
Natriuretic effect by exendin-4, but not the DPP-4 inhibitor alogliptin, is mediated via the GLP-1 receptor and preserved in obese type 2 diabetic mice.
Activation of the glucagon-like peptide (GLP)-1 receptor (GLP-1R) and inhibition of dipeptidyl peptidase-4 (DPP-4) are new antidiabetic strategies. The GLP-1R and DPP-4 are also expressed in the renal proximal tubular brush border, where they may regulate Na(+) reabsorption. Exendin-4 (EX4) is a naturally occurring antidiabetic polypeptide (from the saliva of the lizard Heloderma suspectum) and GLP-1R agonist; however, part of its nonglucoregulatory effects are through GLP-1R-independent mechanisms. DPP-4 cleaves and inactivates GLP-1; thus the natriuretic effect of DPP-4 inhibition may be mediated by the GLP-1R. We report that parenteral application of EX4 in wild-type mice induced a diuresis and natriuresis associated with increases in glomerular filtration rate, fractional urinary fluid and Na(+) excretion, and renal membrane expression of the Na(+)/H(+) exchanger NHE3 phosphorylated at S552 and S605, established consensus sites for cAMP-dependent PKA. These effects were absent in mice lacking the GLP-1R and independent of adenylyl cyclase 6. In comparison, parenteral application of the DPP-4 inhibitor alogliptin reduced plasma DPP-4 activity by 95% and induced a diuresis and natriuresis independent of the presence of the GLP-1R or changes in phosphorylated NHE3. The inhibitory effect on renal fluid and Na(+) reabsorption of EX4, but not alogliptin, was preserved in diabetic db/db mice and associated with a modest reduction in blood pressure. These results reveal mechanistic differences in how EX4 vs. DPP-4 inhibition induces diuresis and natriuresis under normal states, with preservation of GLP-1R-mediated, but not DPP-4 inhibitor-dependent, natriuretic mechanisms in a mouse model of obese type 2 diabetes. Topics: Animals; Blood Glucose; Diabetes Mellitus, Type 2; Dipeptidyl-Peptidase IV Inhibitors; Exenatide; Glucagon-Like Peptide 1; Glucagon-Like Peptide-1 Receptor; Hypoglycemic Agents; Kidney; Mice; Mice, Knockout; Natriuresis; Natriuretic Agents; Obesity; Peptides; Phosphorylation; Piperidines; Receptors, Glucagon; Uracil; Venoms | 2012 |
Long-term clinical and economic outcomes associated with liraglutide versus sitagliptin therapy when added to metformin in the treatment of type 2 diabetes: a CORE Diabetes Model analysis.
A recent open-label, parallel group trial showed that liraglutide is superior to sitagliptin for reduction of HbA1c, and is well tolerated with minimum risk of hypoglycemia. Although these findings support the use of liraglutide as an effective GLP-1 agent to add to metformin, the value of liraglutide needs to be quantified in the framework of a cost-effectiveness (CE) analysis in a US setting.. This current study sets out to assess the long-term cost-effectiveness outcomes of liraglutide vs sitagliptin based on treatment effects data from the 1860-LIRA-DPP-4 52-week trial.. The IMS CORE Diabetes Model (CDM), a non-product-specific, validated computer simulation model that projects the long-term outcomes related to interventions for type 2 diabetes, is used for simulation of these interventions. In the model, patients were treated initially on one of the three treatment options: liraglutide 1.2 mg daily, 1.8 mg daily, or sitagliptin 100 mg daily, each used as add-on therapy to metformin for 5 years. After 5 years all patients switched to basal insulin treatment for the remainder of the simulation (35-year time horizon overall). Incremental cost-effectiveness ratios (ICERs) were generated for liraglutide 1.2 mg compared with sitagliptin and liraglutide 1.8 mg compared with sitagliptin. Transition probabilities, health state utility values, and complication costs were obtained from published sources. All outcomes were discounted at 3% per annum, and the analysis was conducted from the perspective of a third-party payer in the US. Sensitivity analyses were performed to test robustness of the base case scenario.. For liraglutide 1.8 mg vs sitagliptin, the ICER was $37,234 per QALY gained, while for liraglutide 1.2 mg vs sitagliptin, the ICER was $25,742 per QALY gained. In all sensitivity analyses, including setting the change in HbA1c to the lower limits of the 95% confidence intervals, the ICERs remained below US$ 50,000/QALY, a commonly accepted threshold in the US, except for the shortest time horizon of 10 years.. The availability of liraglutide 1.2 mg and 1.8 mg with improved efficacy profiles over sitagliptin could improve patient care, with the incremental cost effectiveness ratio below $50,000 per QALY gained as add-on to metformin. Topics: Computer Simulation; Diabetes Mellitus, Type 2; Drug Therapy, Combination; Glucagon-Like Peptide 1; Humans; Hypoglycemic Agents; Liraglutide; Markov Chains; Metformin; Outcome Assessment, Health Care; Pyrazines; Quality-Adjusted Life Years; Sitagliptin Phosphate; Treatment Outcome; Triazoles | 2012 |
Willingness to pay for diabetes drug therapy in type 2 diabetes patients: based on LEAD clinical programme results.
The purpose of this study was to investigate the preferences of people with diabetes for liraglutide vs other glucose lowering drugs, based on outcomes of clinical trials.. Willingness to pay (WTP) for diabetes drug treatment was assessed by combining results from a recent WTP study with analysis of results from the Liraglutide Effect and Action in Diabetes (LEAD) programme. The LEAD programme included six randomised clinical trials with 3967 participants analysing efficacy and safety of liraglutide 1.2 mg (LEAD 1-6 trials), rosiglitazone (LEAD 1 trial), glimepiride (LEAD 2-3 trials), insulin glargine (LEAD 5 trial), and exenatide (LEAD 6 trial). The WTP survey used discrete choice experimental (DCE) methodology to evaluate the convenience and clinical effects of glucose lowering treatments.. People with type 2 diabetes were prepared to pay an extra €2.64/day for liraglutide compared with rosiglitazone, an extra €1.94/day compared with glimepiride, an extra €3.36/day compared with insulin glargine, and an extra €0.81/day compared with exenatide. Weight loss was the largest component of WTP for liraglutide compared with rosiglitazone, glimepiride, and insulin glargine. Differences in the administration of the two drugs was the largest component of WTP for liraglutide (once daily anytime) compared with exenatide (twice daily with meals). A limitation of the study was that it was based on six clinical trials where liraglutide was the test drug, but each trial had a different comparator, therefore the clinical effects of liraglutide were much better documented than the comparators.. WTP analyses of the clinical results from the LEAD programme suggested that participants with type 2 diabetes were willing to pay appreciably more for liraglutide than other glucose lowering treatments. This was driven by the relative advantage of weight loss compared with rosiglitazone, glimepiride, and insulin glargine, and administration frequency compared with exenatide. Topics: Cost of Illness; Cost-Benefit Analysis; Diabetes Mellitus, Type 2; Disease Management; Exenatide; Glucagon-Like Peptide 1; Humans; Hypoglycemic Agents; Incretins; Insulin Glargine; Insulin, Long-Acting; Liraglutide; Peptides; Randomized Controlled Trials as Topic; Rosiglitazone; Sulfonylurea Compounds; Thiazolidinediones; Venoms; Weight Loss | 2012 |
[Basal insulin and GLP-1 agonist potentiate each other (interview by Dr. med Dirk Einecke)].
Topics: Administration, Oral; Blood Glucose; Diabetes Mellitus, Type 2; Drug Synergism; Drug Therapy, Combination; Glucagon-Like Peptide 1; Glycated Hemoglobin; Humans; Injections, Subcutaneous; Insulin Glargine; Insulin, Long-Acting; Metformin; Peptides; Randomized Controlled Trials as Topic | 2012 |
Type 2 diabetes control in a nonobese rat model using sleeve gastrectomy with duodenal-jejunal bypass (SGDJB).
As a new bariatric procedure, sleeve gastrectomy with duodenal-jejunal bypass (SGDJB) needs further assessment. We compared the diabetic control between SGDJB and sleeve gastrectomy (SG) in Goto-Kakizaki (GK) rats, a nonobese rat model of type 2 diabetes. Our aim is firstly to develop a nonobese diabetic rat model for SGDJB and secondly to investigate the feasibility and safety of SGDJB to induce diabetes remission.. Fifty 11-week-old male GK rats were divided into five groups: sham-operated SG (SOSG), sham-operated SGDJB (SOSGDJB), control, SG, and SGDJB. Rats were observed for 16 weeks after surgery. The body weight, food intake, glycemic control outcomes, ghrelin, peptide YY (PYY), insulin, glucagon-like peptide 1 (GLP-1), and glucose-dependent insulinotropic peptide were measured.. The operated groups showed lower food intake since 4 weeks postoperation and significant weight loss since 6 weeks postoperation. SGDJB and SG surgeries induced a decreased fasting ghrelin level and increased levels of glucose-stimulated insulin, GLP-1, and PYY secretion at 2 and 16 weeks postoperation. Compared with the SG group, the SGDJB group showed higher glucose-stimulated GLP-1 levels. Both SGDJB and SG groups exhibited significant improvement in oral glucose tolerance and insulin tolerance compared with sham-operated and control groups, but there was no difference between the operated groups.. This nonobese diabetic rat model may be valuable in studying the effect of SGDJB on diabetic control. SGDJB shows similar improvement of glucose metabolism with SG. Our findings do not provide evidence for the foregut-mediated amelioration in glucose homeostasis. Topics: Animals; Blood Glucose; Diabetes Mellitus, Experimental; Diabetes Mellitus, Type 2; Duodenum; Gastroplasty; Ghrelin; Glucagon-Like Peptide 1; Glucose Tolerance Test; Homeostasis; Insulin; Jejunum; Male; Rats; Rats, Inbred Strains; Remission Induction; Weight Loss | 2012 |
Sitagliptin reduces hyperglycemia and increases satiety hormone secretion more effectively when used with a novel polysaccharide in obese Zucker rats.
The novel polysaccharide (NPS) PolyGlycopleX (PGX) has been shown to reduce glycemia. Pharmacological treatment with sitagliptin, a dipeptidyl peptidase 4 (DPP4) inhibitor, also reduces glycemia by increasing glucagon-like peptide-1 (GLP-1). Our objective was to determine if using NPS in combination with sitagliptin reduces hyperglycemia in Zucker diabetic fatty (ZDF) rats more so than either treatment alone. Male ZDF rats were randomized to: 1) cellulose/vehicle [control (C)]; 2) NPS (5% wt:wt)/vehicle (NPS); 3) cellulose/sitagliptin [10 mg/(kg · d) (S)]; or 4) NPS (5%) + S [10 mg/(kg · d) (NPS+S)]. Glucose tolerance, adiposity, satiety hormones, and mechanisms related to DPP4 activity and hepatic and pancreatic histology were examined. A clinically relevant reduction in hyperglycemia occurred in the rats treated with NPS+S (P = 0.001) compared with NPS and S alone. Blood glucose, measured weekly in fed and feed-deprived rats and during an oral glucose tolerance test, was lower in the NPS+S group compared with all other groups (all P = 0.001). At wk 6, glycated hemoglobin was lower in the NPS+S group than in the C and S (P = 0.001) and NPS (P = 0.06) groups. PGX (P = 0.001) and S (P = 0.014) contributed to increased lean mass. Active GLP-1 was increased by S (P = 0.001) and GIP was increased by NPS (P = 0.001). Plasma DPP4 activity was lower in the NPS+S and S groups than in the NPS and C groups (P = 0.007). Insulin secretion and β-cell mass was increased with NPS (P < 0.05). NPS alone reduced LDL cholesterol and hepatic steatosis (P < 0.01). Independently, NPS and S improve several metabolic outcomes in ZDF rats, but combined, their ability to markedly reduce glycemia suggests they may be a promising dietary/pharmacological co-therapy for type 2 diabetes management. Topics: Alginates; Animals; Blood Glucose; Diabetes Mellitus, Type 2; Dipeptidyl Peptidase 4; Dipeptidyl-Peptidase IV Inhibitors; Drug Combinations; Glucagon-Like Peptide 1; Glucose Tolerance Test; Hyperglycemia; Insulin; Insulin Secretion; Insulin-Secreting Cells; Male; Obesity; Polysaccharides, Bacterial; Pyrazines; Rats; Rats, Zucker; Satiation; Sitagliptin Phosphate; Triazoles | 2012 |
The effectiveness of liraglutide in nonalcoholic fatty liver disease patients with type 2 diabetes mellitus compared to sitagliptin and pioglitazone.
BACKGROUND. Liraglutide leading to improve not only glycaemic control but also liver inflammation in non-alcoholic fatty liver disease (NAFLD) patients. AIMS. The aim of this study is to elucidate the effectiveness of liraglutide in NAFLD patients with type 2 diabetes mellitus (T2DM) compared to sitagliptin and pioglitazone. METHODS. We retrospectively enrolled 82 Japanese NAFLD patients with T2DM and divided into three groups (liraglutide: N = 26, sitagliptin; N = 36, pioglitazone; N = 20). We compared the baseline characteristics, changes of laboratory data and body weight. RESULTS. At the end of follow-up, ALT, fast blood glucose, and HbA1c level significantly improved among the three groups. AST to platelet ratio significantly decreased in liraglutide group and pioglitazone group. The body weight significantly decreased in liraglutide group (81.8 kg to 78.0 kg, P < 0.01). On the other hands, the body weight significantly increased in pioglitazone group and did not change in sitagliptin group. Multivariate regression analysis indicated that administration of liraglutide as an independent factor of body weight reduction for more than 5% (OR 9.04; 95% CI 1.12-73.1, P = 0.04). CONCLUSIONS. Administration of liraglutide improved T2DM but also improvement of liver inflammation, alteration of liver fibrosis, and reduction of body weight. Topics: Adult; Alanine Transaminase; Blood Glucose; Body Weight; Comorbidity; Diabetes Mellitus, Type 2; Drug Evaluation; Drug Therapy, Combination; Fatty Liver; Female; Follow-Up Studies; Glucagon-Like Peptide 1; Glycated Hemoglobin; Humans; Inflammation; Liraglutide; Liver Cirrhosis; Logistic Models; Male; Middle Aged; Multivariate Analysis; Non-alcoholic Fatty Liver Disease; Odds Ratio; Pioglitazone; Platelet Count; Pyrazines; Retrospective Studies; Sitagliptin Phosphate; Thiazolidinediones; Treatment Outcome; Triazoles | 2012 |
Small molecule allosteric modulation of the glucagon-like Peptide-1 receptor enhances the insulinotropic effect of oxyntomodulin.
Identifying novel mechanisms to enhance glucagon-like peptide-1 (GLP-1) receptor signaling may enable nascent medicinal chemistry strategies with the aim of developing new orally available therapeutic agents for the treatment of type 2 diabetes mellitus. Therefore, we tested the hypothesis that selectively modulating the low-affinity GLP-1 receptor agonist, oxyntomodulin, would improve the insulin secretory properties of this naturally occurring hormone to provide a rationale for pursuing an unexplored therapeutic approach. Signal transduction and competition binding studies were used to investigate oxyntomodulin activity on the GLP-1 receptor in the presence of the small molecule GLP-1 receptor modulator, 4-(3-benzyloxyphenyl)-2-ethylsulfinyl-6-(trifluoromethyl)pyrimidine (BETP). In vivo, the intravenous glucose tolerance test characterized oxyntomodulin-induced insulin secretion in animals administered the small molecule. BETP increased oxyntomodulin binding affinity for the GLP-1 receptor and enhanced oxyntomodulin-mediated GLP-1 receptor signaling as measured by activation of the α subunit of heterotrimeric G protein and cAMP accumulation. In addition, oxyntomodulin-induced insulin secretion was enhanced in the presence of the compound. BETP was pharmacologically characterized to induce biased signaling by oxyntomodulin. These studies demonstrate that small molecules targeting the GLP-1 receptor can increase binding and receptor activation of the endogenous peptide oxyntomodulin. The biased signaling engendered by BETP suggests that GLP-1 receptor mobilization of cAMP is the critical insulinotropic signaling event. Because of the unique metabolic properties of oxyntomodulin, identifying molecules that enhance its activity should be pursued to assess the efficacy and safety of this novel mechanism. Topics: Animals; Cell Line; CHO Cells; Cricetinae; Cyclic AMP; Diabetes Mellitus, Type 2; Drug Synergism; Glucagon-Like Peptide 1; Glucagon-Like Peptide-1 Receptor; GTP-Binding Proteins; HEK293 Cells; Humans; Hypoglycemic Agents; Insulin; Oxyntomodulin; Receptors, Glucagon; Signal Transduction | 2012 |
Phosphodiesterase III inhibition increases cAMP levels and augments the infarct size limiting effect of a DPP-4 inhibitor in mice with type-2 diabetes mellitus.
We assessed whether phosphodiesterase-III inhibition with cilostazol (Cil) augments the infarct size (IS)-limiting effects of MK0626 (MK), a dipeptidyl-peptidase-4 (DPP4) inhibitor, by increasing intracellular cAMP in mice with type-2 diabetes.. Db/Db mice received 3-day MK (0, 1, 2 or 3 mg/kg/d) with or without Cil (15 mg/kg/d) by oral gavage and were subjected to 30 min coronary artery occlusion and 24 h reperfusion.. Cil and MK at 2 and 3 mg/kg/d significantly reduced IS. Cil and MK had additive effects at all three MK doses. IS was the smallest in the MK-3+Cil. MK in a dose dependent manner and Cil increased cAMP levels (p < 0.001). cAMP levels were higher in the combination groups at all MK doses. MK-2 and Cil increased PKA activity when given alone; however, PKA activity was significantly higher in the MK-2+Cil group than in the other groups. Both MK-2 and Cil increased myocardial levels of Ser(133) P-CREB, Ser(523) P-5-lipoxygenase, Ser(473)P-Akt and Ser(633) P-eNOS. These levels were significantly higher in the MK-2+Cil group. Myocardial PTEN (Phosphatase and tensin homolog on chromosome ten) levels were significantly higher in the Db/Db mice compared to nondiabetic mice. MK-2 and Cil normalized PTEN levels. PTEN levels tended to be lower in the combination group than in the MK and Cil alone groups.. MK and Cil have additive IS-limiting effects in diabetic mice. The additive effects are associated with an increase in myocardial cAMP levels and PKA activity with downstream phosphorylation of Akt, eNOS, 5-lipoxygenase and CREB and downregulation of PTEN expression. Topics: Animals; Blood Glucose; Cilostazol; Cyclic AMP; Cyclic AMP-Dependent Protein Kinases; Diabetes Mellitus, Type 2; Disease Models, Animal; Dose-Response Relationship, Drug; Drug Therapy, Combination; Glucagon-Like Peptide 1; Glycated Hemoglobin; Immunoblotting; Lipids; Lipoxins; Male; Membrane Proteins; Mice; Myocardial Infarction; Myocardium; Phosphodiesterase 3 Inhibitors; PTEN Phosphohydrolase; Tetrazoles; Triazoles | 2012 |
Adult glucose metabolism in extremely birthweight-discordant monozygotic twins.
Low birthweight (BW) is associated with increased risk of type 2 diabetes. We compared glucose metabolism in adult BW-discordant monozygotic (MZ) twins, thereby controlling for genetic factors and rearing environment.. Among 77,885 twins in the Danish Twin Registry, 155 of the most BW-discordant MZ twin pairs (median BW difference 0.5 kg) were assessed using a 2 h oral glucose tolerance test with sampling of plasma (p-)glucose, insulin, C-peptide, glucose-dependent insulinotropic polypeptide and glucagon-like peptide-1. HOMA for beta cell function (HOMA-β) and insulin resistance (HOMA-IR), and also insulin sensitivity index (BIGTT-SI) and acute insulin response (BIGTT-AIR), were calculated. Subgroup analyses were performed in those with: (1) double verification of BW difference; (2) difference in BW >0.5 kg; and (3) no overt metabolic disease (type 2 diabetes, hyperlipidaemia or thyroid disease).. No intra-pair differences in p-glucose, insulin, C-peptide, incretin hormones, HOMA-β, HOMA-IR or BIGTT-SI were identified. p-Glucose at 120 min was higher in the twins with the highest BW without metabolic disease, and BIGTT-AIR was higher in those with the highest BW although not in pairs with a BW difference of >0.5 kg.. BW-discordant MZ twins provide no evidence for a detrimental effect of low BW on glucose metabolism in adulthood once genetic factors and rearing environment are controlled for. Topics: Adult; Aged; Analysis of Variance; Birth Weight; Blood Glucose; C-Peptide; Denmark; Diabetes Mellitus, Type 2; Disease Susceptibility; Female; Glucagon-Like Peptide 1; Glucose Intolerance; Glucose Tolerance Test; Humans; Infant, Low Birth Weight; Infant, Newborn; Insulin Resistance; Logistic Models; Male; Middle Aged; Risk Factors; Surveys and Questionnaires; Twins, Monozygotic | 2012 |
Pancreatitis during treatment with liraglutide.
Topics: Acute Disease; Aged; Diabetes Mellitus, Type 2; Glucagon-Like Peptide 1; Humans; Liraglutide; Male; Pancreatitis | 2012 |
A local glucagon-like peptide 1 (GLP-1) system in human pancreatic islets.
Glucagon-like peptide 1 (GLP-1) is a major incretin, mainly produced by the intestinal L cells, with beneficial actions on pancreatic beta cells. However, while in vivo only very small amounts of GLP-1 reach the pancreas in bioactive form, some observations indicate that GLP-1 may also be produced in the islets. We performed comprehensive morphological, functional and molecular studies to evaluate the presence and various features of a local GLP-1 system in human pancreatic islet cells, including those from type 2 diabetic patients.. The presence of insulin, glucagon, GLP-1, proconvertase (PC) 1/3 and PC2 was determined in human pancreas by immunohistochemistry with confocal microscopy. Islets were isolated from non-diabetic and type 2 diabetic donors. GLP-1 protein abundance was evaluated by immunoblotting and matrix-assisted laser desorption-ionisation-time of flight (MALDI-TOF) mass spectrometry. Single alpha and beta cell suspensions were obtained by enzymatic dissociation and FACS sorting. Glucagon and GLP-1 release were measured in response to nutrients.. Confocal microscopy showed the presence of GLP-1-like and PC1/3 immunoreactivity in subsets of alpha cells, whereas GLP-1 was not observed in beta cells. The presence of GLP-1 in isolated islets was confirmed by immunoblotting, followed by mass spectrometry. Isolated islets and alpha (but not beta) cell fractions released GLP-1, which was regulated by glucose and arginine. PC1/3 (also known as PCSK1) gene expression was shown in alpha cells. GLP-1 release was significantly higher from type 2 diabetic than from non-diabetic isolated islets.. We have shown the presence of a functionally competent GLP-1 system in human pancreatic islets, which resides in alpha cells and might be modulated by type 2 diabetes. Topics: Diabetes Mellitus, Type 2; Female; Glucagon; Glucagon-Like Peptide 1; Glucagon-Secreting Cells; Humans; Immunohistochemistry; Insulin; Male; Mass Spectrometry; Middle Aged; Pancreas | 2012 |
[New pharmacological treatment methods of type 2 diabetes].
The variable pathogenesis and progressive nature of type 2 diabetes emphasise the need for new antidiabetic treatments. The long acting glucagon-like peptide-1 receptor agonists and dipeptidyl peptidase-4 inhibitors have improved the treatment. Novel approaches include inhibitors of sodium glucose co-transporter 2, which increase renal glucose elimination, G-protein-coupled receptor agonists, which potentiate insulin and incretin hormone secretion. Proof of principle has been shown for glucagon receptor agonists, glucokinase activators and treatment with dual intestinal peptides, which all induce weight loss and improve glucose tolerance. Topics: Benzofurans; Diabetes Mellitus, Type 2; Dipeptidyl-Peptidase IV Inhibitors; Dopamine Agonists; Glucagon-Like Peptide 1; Glucagon-Like Peptide-1 Receptor; Glucokinase; Humans; Hyperglycemia; Hypoglycemic Agents; Insulin, Long-Acting; Peptides, Cyclic; Receptors, G-Protein-Coupled; Receptors, Glucagon; Sodium-Glucose Transporter 2 Inhibitors; Sulfones; Weight Loss | 2012 |
Efficacy of liraglutide, a glucagon-like peptide-1 (GLP-1) analogue, on body weight, eating behavior, and glycemic control, in Japanese obese type 2 diabetes.
We recently reported that short-term treatment with liraglutide (20.0 ± 6.4 days) reduced body weight and improved some scales of eating behavior in Japanese type 2 diabetes inpatients. However, it remained uncertain whether such liraglutide-induced improvement is maintained after discharge from the hospital. The aim of the present study was to determine the long-term effects of liraglutide on body weight, glycemic control, and eating behavior in Japanese obese type 2 diabetics.. Patients with obesity (body mass index (BMI) >25 kg/m(2)) and type 2 diabetes were hospitalized at Osaka University Hospital between November 2010 and December 2011. BMI and glycated hemoglobin (HbA1c) were examined on admission, at discharge and at 1, 3, and 6 months after discharge. For the liraglutide group (BMI; 31.3 ± 5.3 kg/m(2), n = 29), patients were introduced to liraglutide after correction of hyperglycemic by insulin or oral glucose-lowering drugs and maintained on liraglutide after discharge. Eating behavior was assessed in patients treated with liraglutide using The Guideline For Obesity questionnaire issued by the Japan Society for the Study of Obesity, at admission, discharge, 3 and 6 months after discharge. For the insulin group (BMI; 29.1 ± 3.0 kg/m(2), n = 28), each patient was treated with insulin during hospitalization and glycemic control maintained by insulin after discharge.. Liraglutide induced significant and persistent weight loss from admission up to 6 months after discharge, while no change in body weight after discharge was noted in the insulin group. Liraglutide produced significant improvements in all major scores of eating behavior questionnaire items and such effect was maintained at 6 months after discharge. Weight loss correlated significantly with the decrease in scores for recognition of weight and constitution, sense of hunger, and eating style.. Liraglutide produced meaningful long-term weight loss and significantly improved eating behavior in obese Japanese patients with type 2 diabetes. Topics: Aged; Anti-Obesity Agents; Asian People; Biomarkers; Blood Glucose; Body Mass Index; Body Weight; Chi-Square Distribution; Diabetes Mellitus, Type 2; Feeding Behavior; Female; Glucagon-Like Peptide 1; Glycated Hemoglobin; Humans; Hypoglycemic Agents; Insulin; Japan; Liraglutide; Male; Middle Aged; Obesity; Time Factors; Treatment Outcome | 2012 |
Glucagon-like peptide-1 (GLP-1) receptor agonism or DPP-4 inhibition does not accelerate neoplasia in carcinogen treated mice.
Glucagon-like peptide-1 (GLP-1) and glucagon-like peptide-2 (GLP-2) are secreted in parallel from the intestinal endocrine cells after nutrient intake. GLP-1 is an incretin hormone and analogues are available for the treatment of type 2 diabetes mellitus (T2DM). GLP-2 is an intestinal growth hormone and is shown to promote growth of colonic adenomas in carcinogen treated mice. Both peptides are degraded by dipeptidyl peptidase-4 (DPP-4) into inactive metabolites. DPP-4 inhibitors are therefore also in use for treatment of T2DM. It is possible that DPP-4 inhibition by enhancing the exposure of endogenous GLP-2 to the intestinal epithelia also might mediate growth and promote neoplasia. We investigated the intestinal growth effect of the GLP-1 receptor agonists (GLP-1 RAs) (liraglutide and exenatide) and DPP-4 inhibition (sitagliptin) in healthy mice. We also investigated the potential tumour promoting effect of liraglutide and sitaglitin in the colon of carcinogen treated mice. We used GLP-2 as a positive control.. For the growth study we treated healthy CD1 mice with liraglutide (300 μg×2), exenatide (12.5 μg×2) or vehicle subcutaneously and sitagliptin (8mg×2) or water by oral gavage for 10 or 30 days. We measured intestinal weight, cross sectional area, villus height and crypt depth. For the tumour study we treated carcinogen treated mice (1,2 dimethylhydrazine 21 mg/kg/week for 12 weeks) with liraglutide (300 μg×2), Gly2-GLP-2 (25 μg×2) or vehicle subcutaneously and sitagliptin (8 mg×2) or water by oral gavage for 45 days. We counted aberrant crypt foci (ACF), mucin depleted foci (MDF) and adenomas in the colon. Using COS-7 cells transfected with a GLP-2 receptor, we tested if liraglutide or exenatide could activate the receptor.. In the 10 days experiment the relative small intestinal weight was increased with 56% in the liraglutide group (p<0.001) and 26% in the exenatide group (p<01) compared with vehicle treated mice. After 30 days of treatment, liraglutide did also increase the colonic weight (p<0.01). By morphometry the growth pattern mimicked that of GLP-2. Sitagliptin treatment had only a minor effect. In the carcinogen treated mice we found no increase of ACF in any of the groups, the numbers of MDF and adenomas after liraglutide and sitagliptin treatments were similar to their respective control groups. Neither liraglutide nor exenatide stimulated cAMP release from GLP-2 receptor transfected cells.. Both GLP-1 analogues were potent growth stimulators of the healthy mouse intestine. No agonism was found for GLP-1 RAs at the GLP-2 receptor. Despite of the growth effect, liraglutide did not promote dysplasia in the colon. Sitagliptin did not show any tumour promoting effects, and non considerable growth effects. Topics: 1,2-Dimethylhydrazine; Aberrant Crypt Foci; Adenoma; Anatomy, Cross-Sectional; Animals; Chlorocebus aethiops; Colon; Colonic Neoplasms; COS Cells; Cyclic AMP; Diabetes Mellitus, Type 2; Dipeptidyl Peptidase 4; Dipeptidyl-Peptidase IV Inhibitors; Exenatide; Female; Glucagon-Like Peptide 1; Glucagon-Like Peptide-1 Receptor; Glucagon-Like Peptide-2 Receptor; Hypoglycemic Agents; Intestinal Mucosa; Intestine, Small; Liraglutide; Mice; Mice, Inbred C57BL; Organ Size; Peptides; Pyrazines; Receptors, Glucagon; Sitagliptin Phosphate; Transfection; Triazoles; Venoms | 2012 |
Cost-utility analysis of liraglutide versus glimepiride as add-on to metformin in type 2 diabetes patients in China.
The aim of this study was to evaluate the long-term cost-utility of liraglutide versus glimepiride as add-on therapy to metformin in patients with type 2 diabetes mellitus (T2DM), based on the results of clinical trial conducted in Asian population.. The validated UKPDS Outcomes Model was used to project life expectancy, quality adjusted life-years (QALYs), incidence of diabetes-related complication and cost of complications in patients receiving those regimens. Baseline cohort characteristics and treatment effects were derived from an Asian study. China-specific complication costs and utility score were taken from local studies. Patients' outcomes were modeled for 30 years and incremental cost-effectiveness ratios were calculated for liraglutide compared with glimepiride from the healthcare system perspective. Both future costs and clinical benefits were discounted at 3 percent. Sensitivity analyses were performed.. Over a period of 30 years, compared with glimepiride, liraglutide 1.8 mg was associated with improvements in life expectancy (0.1 year) and quality adjusted life-year (0.168 QALY), and a reduced incidence of diabetes-related complications leading to an incremental cost-effectiveness ratio per QALY gained versus glimepiride of CNY 25,6871 (DEC 2010, 1 USD = 6.6227 CNY).. Long-term projections indicated that liraglutide was associated with increased life expectancy, QALYs, and reduced complication incidences comparing with glimepiride. When the UK cost of liraglutide was discounted by 38 percent, liraglutide would be a cost-effective option in China from the healthcare system perspective using the 3X GDP/capita per QALY as the WTP threshold. Topics: China; Confidence Intervals; Cost-Benefit Analysis; Diabetes Mellitus, Type 2; Drug Therapy, Combination; Glucagon-Like Peptide 1; Health Care Costs; Humans; Hypoglycemic Agents; Life Expectancy; Liraglutide; Metformin; Models, Economic; Quality-Adjusted Life Years; Sulfonylurea Compounds | 2012 |
A novel, potent, and long-lasting dipeptidyl peptidase-4 inhibitor, teneligliptin, improves postprandial hyperglycemia and dyslipidemia after single and repeated administrations.
Dipeptidyl peptidase-4 (DPP-4) inhibitors have been demonstrated to improve glycemic control, in particular postprandial hyperglycemic control, in patients with type 2 diabetes. Teneligliptin is a novel chemotype prolylthiazolidine-based DPP-4 inhibitor. The present study aimed to characterize the pharmacological profiles of teneligliptin in vitro and in vivo. Teneligliptin competitively inhibited human plasma, rat plasma, and human recombinant DPP-4 in vitro, with IC(50) values of approximately 1 nmol/l. Oral administration of teneligliptin in Wistar rats resulted in the inhibition of plasma DPP-4 with an ED(50) of 0.41 mg/kg. Plasma DPP-4 inhibition was sustained even at 24h after administration of teneligliptin. An oral carbohydrate-loading test in Zucker fatty rats showed that teneligliptin at ≥ 0.1mg/kg increased the maximum increase in plasma glucagon-like peptide-1 and insulin levels, and reduced glucose excursions. This effect was observed over 12h after a dose of 1mg/kg. An oral fat-loading test in Zucker fatty rats also showed that teneligliptin at 1mg/kg reduced triglyceride and free fatty acid excursions. In Zucker fatty rats, repeated administration of teneligliptin for two weeks reduced glucose excursions in the oral carbohydrate-loading test and decreased the plasma levels of triglycerides and free fatty acids under non-fasting conditions. The present studies indicate that teneligliptin is a potent, competitive, and long-lasting DPP-4 inhibitor that improves postprandial hyperglycemia and dyslipidemia by both single and repeated administrations. Topics: Adamantane; Animals; Blood Glucose; Diabetes Mellitus, Type 2; Dipeptidyl Peptidase 4; Dipeptidyl-Peptidase IV Inhibitors; Glucagon-Like Peptide 1; Hyperglycemia; Hypertriglyceridemia; Hypoglycemic Agents; Hypolipidemic Agents; Insulin; Male; Nitriles; Pyrazines; Pyrazoles; Pyrrolidines; Rats; Rats, Wistar; Rats, Zucker; Sitagliptin Phosphate; Thiazolidines; Triazoles; Vildagliptin | 2012 |
C-peptide response to glucagon challenge is correlated with improvement of early insulin secretion by liraglutide treatment.
The amelioration of glucose tolerance by liraglutide was associated with a significant improvement of early insulin-response during OGTT. The serum C-peptide response to glucagon challenge strongly correlated with the improvement of the early insulin-response. The C-peptide response to glucagon challenge would be useful to predict therapeutic response to liraglutide. Topics: Adult; Aged; C-Peptide; Diabetes Mellitus, Type 2; Dose-Response Relationship, Drug; Drug Monitoring; Drug Resistance; Female; Glucagon; Glucagon-Like Peptide 1; Glucagon-Like Peptide-1 Receptor; Glucose Tolerance Test; Humans; Hypoglycemic Agents; Insulin; Insulin Secretion; Insulin-Secreting Cells; Kinetics; Liraglutide; Male; Middle Aged; Receptors, Glucagon | 2012 |
Novo Nordisk incretin leadership summit, Cape Town.
Topics: Diabetes Mellitus, Type 2; Glucagon-Like Peptide 1; Humans; Incretins; Insulin-Secreting Cells; South Africa | 2012 |
[Glucagon-like peptide 1 analogues in the treatment of type 2 diabetes mellitus].
Topics: Diabetes Mellitus, Type 2; Glucagon-Like Peptide 1; Humans; Hypoglycemic Agents; Incretins | 2012 |
Pancreatitis with pancreatic tail swelling associated with incretin-based therapies detected radiologically in two cases of diabetic patients with end-stage renal disease.
We herein report two cases of pancreatitis associated with incretin-based therapies in end-stage renal disease (ESRD) patients undergoing dialysis. A 75-year-old woman with a history of liraglutide use and a 68-year-old man with a history of vildagliptin use both presented with nausea. They showed elevated levels of pancreatic enzymes and pancreatic tail swelling on CT. Their symptoms improved after discontinuing the drugs. In the absence of any obvious secondary causes of pancreatitis, we believe that the pancreatitis observed in these cases was associated with the incretin-based therapies. Few reports have been published on the safety and efficacy of incretin-based therapies in ESRD patients, and it remains uncertain whether the changes in the pancreas observed in the present cases are characteristic of ESRD patients. Topics: Adamantane; Aged; Diabetes Mellitus, Type 2; Diabetic Nephropathies; Female; Glucagon-Like Peptide 1; Humans; Incretins; Kidney Failure, Chronic; Liraglutide; Magnetic Resonance Imaging; Male; Nitriles; Pancreatitis; Pyrrolidines; Renal Dialysis; Tomography, X-Ray Computed; Vildagliptin | 2012 |
GLP-1 receptor activation inhibits VLDL production and reverses hepatic steatosis by decreasing hepatic lipogenesis in high-fat-fed APOE*3-Leiden mice.
In addition to improve glucose intolerance, recent studies suggest that glucagon-like peptide-1 (GLP-1) receptor agonism also decreases triglyceride (TG) levels. The aim of this study was to evaluate the effect of GLP-1 receptor agonism on very-low-density lipoprotein (VLDL)-TG production and liver TG metabolism.. The GLP-1 peptide analogues CNTO3649 and exendin-4 were continuously administered subcutaneously to high fat diet-fed APOE*3-Leiden transgenic mice. After 4 weeks, hepatic VLDL production, lipid content, and expression profiles of selected genes involved in lipid metabolism were determined.. CNTO3649 and exendin-4 reduced fasting plasma glucose (up to -30% and -28% respectively) and insulin (-43% and -65% respectively). In addition, these agents reduced VLDL-TG production (-36% and -54% respectively) and VLDL-apoB production (-36% and -43% respectively), indicating reduced production of VLDL particles rather than reduced lipidation of apoB. Moreover, they markedly decreased hepatic content of TG (-39% and -55% respectively), cholesterol (-30% and -55% respectively), and phospholipids (-23% and -36% respectively), accompanied by down-regulation of expression of genes involved in hepatic lipogenesis (Srebp-1c, Fasn, Dgat1) and apoB synthesis (Apob).. GLP-1 receptor agonism reduces VLDL production and hepatic steatosis in addition to an improvement of glycemic control. These data suggest that GLP-receptor agonists could reduce hepatic steatosis and ameliorate dyslipidemia in patients with type 2 diabetes mellitus. Topics: Animals; Apolipoprotein E3; Apolipoproteins B; Blood Glucose; Diabetes Mellitus, Type 2; Dyslipidemias; Exenatide; Fatty Liver; Glucagon-Like Peptide 1; Glucagon-Like Peptide-1 Receptor; Insulin; Lipogenesis; Liver; Male; Mice; Mice, Transgenic; Peptides; Receptors, Glucagon; Venoms | 2012 |
[Effect of dendrobium mixture on hypoglycemic and the apoptosis of islet in rats with type 2 diabetic mellitus].
To study the effect of Dendrobium mixture on hypoglycemic and the apoptosis of islet in rats with type 2 diabetic mellitus.. Type 2 diabetes mellitus models were induced by high sugar and fat diet and low dose intraperitoneal injection of streptozotocin (STZ) in rats, and treated with Dendrobium mixture (5, 10, 20 g/kg) by intragastric administration. Observed islet cell morphology with histopathological techniques and tested the apoptosis of islet cells by MTT and Annexin V/PI method.. Dendrobium mixture could reduce the levels of blood glucose, triglyceride and glucosylated serum protein effectively and significantly improve the modeling structure and function of rat pancreatic tissue. The apoptotic islet cells was significantly reduced (P < 0.01) in treatment group compared with the model group.. Dendrobium mixture have a hypoglycemic effect on rat models of type 2 diabetes. It can protect and restore the structure and function of pancreatic tissue. Topics: Administration, Oral; Animals; Apoptosis; Blood Glucose; Cells, Cultured; Dendrobium; Diabetes Mellitus, Experimental; Diabetes Mellitus, Type 2; Disease Models, Animal; Drug Combinations; Drugs, Chinese Herbal; Female; Glucagon-Like Peptide 1; Hypoglycemic Agents; Insulin; Islets of Langerhans; Plants, Medicinal; Rats; Rats, Sprague-Dawley; Streptozocin; Triglycerides | 2012 |
Improved glycaemia correlates with liver fat reduction in obese, type 2 diabetes, patients given glucagon-like peptide-1 (GLP-1) receptor agonists.
Glucagon-like peptide-1 receptor agonists (GLP-1 RA) are effective for obese patients with type 2 diabetes mellitus (T2DM) because they concomitantly target obesity and dysglycaemia. Considering the high prevalence of non-alcoholic fatty liver disease (NAFLD) in patients with T2DM, we determined the impact of 6 months' GLP-1 RA therapy on intrahepatic lipid (IHL) in obese, T2DM patients with hepatic steatosis, and evaluated the inter-relationship between changes in IHL with those in glycosylated haemoglobin (HbA(1)c), body weight, and volume of abdominal visceral and subcutaneous adipose tissue (VAT and SAT). We prospectively studied 25 (12 male) patients, age 50±10 years, BMI 38.4±5.6 kg/m(2) (mean ± SD) with baseline IHL of 28.2% (16.5 to 43.1%) and HbA(1)c of 9.6% (7.9 to 10.7%) (median and interquartile range). Patients treated with metformin and sulphonylureas/DPP-IV inhibitors were given 6 months GLP-1 RA (exenatide, n = 19; liraglutide, n = 6). IHL was quantified by liver proton magnetic resonance spectroscopy ((1)H MRS) and VAT and SAT by whole body magnetic resonance imaging (MRI). Treatment was associated with mean weight loss of 5.0 kg (95% CI 3.5,6.5 kg), mean HbA(1c) reduction of 1·6% (17 mmol/mol) (0·8,2·4%) and a 42% relative reduction in IHL (-59.3, -16.5%). The relative reduction in IHL correlated with that in HbA(1)c (ρ = 0.49; p = 0.01) but was not significantly correlated with that in total body weight, VAT or SAT. The greatest IHL reduction occurred in individuals with highest pre-treatment levels. Mechanistic studies are needed to determine potential direct effects of GLP-1 RA on human liver lipid metabolism. Topics: Adiposity; Adult; Blood Glucose; Body Mass Index; Body Weight; Diabetes Mellitus, Type 2; Exenatide; Fatty Liver; Female; Glucagon-Like Peptide 1; Humans; Hypoglycemic Agents; Liraglutide; Liver; Male; Middle Aged; Obesity; Peptides; Prospective Studies; Venoms; Weight Loss | 2012 |
[Towards evidence-based medicine: large-scale intervention trials with glucagon-like peptide-1 receptor agonists].
The primary goal of antihyperglycemic therapy in type 2 diabetes mellitus is to reduce cardiovascular morbidity and mortality. As a consequence, drugs used for the treatment of diabetes must be safe with respect to cardiovascular risk. It would be ideal if antidiabetic drugs could also promote cardiovascular protection mechanisms independent of improved glucose control. Glucagon-like peptide-1 (GLP-1) receptor agonists might indeed be such drugs. Experimental studies in animal models as well as preliminary results in man have provided evidence that GLP-1 receptor agonists may have protective effects on the cardiovascular system. In addition, registration trial data have demonstrated that treatment with liraglutide is associated with a significant improvement in several cardiovascular risk factors. However, definite confirmation of both absolute cardiovascular safety and potential cardiovascular protective effects of GLP-1 receptor agonists can only be provided by large, randomized, controlled intervention trials specifically designed to answer these questions. The design of such ongoing trials is described in this article. Topics: Clinical Trials as Topic; Diabetes Mellitus, Type 2; Evidence-Based Medicine; Exenatide; Glucagon-Like Peptide 1; Humans; Hypoglycemic Agents; Peptides; Venoms | 2012 |
Discovery of potent, selective, and orally bioavailable quinoline-based dipeptidyl peptidase IV inhibitors targeting Lys554.
Dipeptidyl peptidase IV (DPP-4) inhibition is a validated therapeutic option for type 2 diabetes, exhibiting multiple antidiabetic effects with little or no risk of hypoglycemia. In our studies involving non-covalent DPP-4 inhibitors, a novel series of quinoline-based inhibitors were designed based on the co-crystal structure of isoquinolone 2 in complex with DPP-4 to target the side chain of Lys554. Synthesis and evaluation of designed compounds revealed 1-[3-(aminomethyl)-4-(4-methylphenyl)-2-(2-methylpropyl)quinolin-6-yl]piperazine-2,5-dione (1) as a potent, selective, and orally active DPP-4 inhibitor (IC₅₀=1.3 nM) with long-lasting ex vivo activity in dogs and excellent antihyperglycemic effects in rats. A docking study of compound 1 revealed a hydrogen-bonding interaction with the side chain of Lys554, suggesting this residue as a potential target site useful for enhancing DPP-4 inhibition. Topics: Animals; Caco-2 Cells; Cell Line; Diabetes Mellitus, Type 2; Dipeptidyl Peptidase 4; Dipeptidyl-Peptidase IV Inhibitors; Dogs; Female; Humans; Hypoglycemic Agents; Lysine; Quinolines; Rats; Rats, Wistar | 2011 |
Metformin regulates the incretin receptor axis via a pathway dependent on peroxisome proliferator-activated receptor-α in mice.
Metformin is widely used for the treatment of type 2 diabetes. Although it reduces hepatic glucose production, clinical studies show that metformin may reduce plasma dipeptidyl peptidase-4 activity and increase circulating levels of glucagon-like peptide 1 (GLP-1). We examined whether metformin exerts glucoregulatory actions via modulation of the incretin axis.. Metformin action was assessed in Glp1r(-/-), Gipr(-/-), Glp1r:Gipr(-/-), Pparα (also known as Ppara)(-/-) and hyperglycaemic obese wild-type mice with or without the GLP-1 receptor (GLP1R) antagonist exendin(9-39). Experimental endpoints included glucose tolerance, plasma insulin levels, gastric emptying and food intake. Incretin receptor expression was assessed in isolated islets from metformin-treated wild-type and Pparα(-/-) mice, and in INS-1 832/3 beta cells with or without peroxisome proliferator-activated receptor (PPAR)-α or AMP-activated protein kinase (AMPK) antagonists.. In wild-type mice, metformin acutely increased plasma levels of GLP-1, but not those of gastric inhibitory polypeptide or peptide YY; it also improved oral glucose tolerance and reduced gastric emptying. Metformin significantly improved oral glucose tolerance despite loss of incretin action in Glp1r(-/-), Gipr(-/-) and Glp1r(-/-) :Gipr(-/-) mice, and in wild-type mice fed a high-fat diet and treated with exendin(9-39). Levels of mRNA transcripts for Glp1r, Gipr and Pparα were significantly increased in islets from metformin-treated mice. Metformin directly increased Glp1r expression in INS-1 beta cells via a PPAR-α-dependent, AMPK-independent mechanism. Metformin failed to induce incretin receptor gene expression in islets from Pparα(-/-) mice.. As metformin modulates multiple components of the incretin axis, and enhances expression of the Glp1r and related insulinotropic islet receptors through a mechanism requiring PPAR-α, metformin may be mechanistically well suited for combination with incretin-based therapies. Topics: Animals; Cell Line; Diabetes Mellitus, Type 2; Dipeptidyl Peptidase 4; Eating; Gastric Inhibitory Polypeptide; Glucagon-Like Peptide 1; Glucagon-Like Peptide-1 Receptor; Hypoglycemic Agents; Male; Metformin; Mice; Mice, Inbred C57BL; Mice, Mutant Strains; Peptide Fragments; PPAR alpha; Receptors, Gastrointestinal Hormone; Receptors, Glucagon; Signal Transduction | 2011 |
Discovery and characterization of taspoglutide, a novel analogue of human glucagon-like peptide-1, engineered for sustained therapeutic activity in type 2 diabetes.
Glucagon-like peptide-1 (GLP-1) receptor agonists for the treatment of type 2 diabetes are administered by daily injection because of short plasma half-lives, which result partly from the biochemical instability of these peptides. There is a medical need for GLP-1 analogues that can be administered less frequently for patient convenience.. We synthesized a series of human GLP-1 (hGLP-1(7-36)NH(2) ) derivatives containing α-aminoisobutyric acid (Aib) substitutions, analysed their enzymatic stabilities and evaluated their secondary structures using circular dichroism (CD) and nuclear magnetic resonance (NMR).. Plasma stability experiments showed that only the analogue containing Aib substitutions in both the N-terminus (position 8) and the C-terminus (position 35), [Aib⁸(,)³⁵]hGLP-1(7-36)NH₂ (BIM-51077), was fully resistant to enzymatic cleavage. Incubation with human plasma kallikrein or plasmin confirmed that the Aib substitution at position 35 prevented protease cleavage around this residue, which contributes to the significantly enhanced plasma stability and increased plasma half-life. CD revealed increased C-terminal α-helicity in Aib³⁵-substituted analogues compared with both hGLP-1(7-36)NH₂ and analogues containing only Aib⁸ substitutions. Based on NMR studies, the secondary structure of BIM-51077 is similar to hGLP-1(7-36)NH₂ with a slight increase in α-helicity in the C-terminus. Compared with hGLP-1(7-36)NH₂, BIM-51077 had similar binding affinity for the human GLP-1 receptor and activated this receptor with similar potency.. We have discovered an Aib⁸(,)³⁵-substituted analogue of native hGLP-1(7-36)NH₂ (BIM-51077) that retains the structure of the native peptide, and has similar activity and enhanced stability. A sustained-release formulation of this molecule (taspoglutide) is in phase-3 clinical development. Topics: Diabetes Mellitus, Type 2; Drug Discovery; Drug Stability; Glucagon-Like Peptide 1; Half-Life; Humans; Peptides | 2011 |
Co-administration of liraglutide with insulin detemir demonstrates additive pharmacodynamic effects with no pharmacokinetic interaction.
To compare the pharmacokinetic (PK) [area under the curve (AUC₀(-)₂₄ (h), C(max))] and pharmacodynamic (PD) (AUC(GIR) ₀(-)₂₄ (h), GIR(max)) properties of single-dose insulin detemir in the presence or absence of steady-state liraglutide (1.8 mg dose) in subjects with type 2 diabetes to determine whether co-administration affected the PK and PD profiles of either therapeutic agent.. Following a 3-week washout of oral antidiabetic agents (OADs) other than metformin, PK and PD assessments during three euglycaemia clamps were conducted: day 1 following a single dose of insulin detemir alone (0.5 U/kg), day 22 after 3 weeks of once-daily liraglutide with weekly dose escalation to 1.8 mg daily, and day 36 after 2 weeks of steady-state liraglutide maintenance at the 1.8 mg dose following co-administration with a single dose of insulin detemir (0.5 U/kg).. The study population (N = 33; age 49.6 (±8.5) years) had diabetes for an average of 6.5 (±4.1) years, BMI 33 (±6.4) kg/m², FPG 9.7 (±1.6) mmol/l and HbA1c 8.3% (±0.9). PK: The PK profiles of insulin detemir were similar with and without steady-state liraglutide. Liraglutide did not affect AUC or C(max) of insulin detemir and vice versa. The 90% confidence intervals (CIs) for ratios of insulin detemir AUC [1.03; CI (0.97, 1.09)] and C(max) [1.05; CI (0.98, 1.13)] and liraglutide AUC [0.97; CI (0.87, 1.08)] and C(max) [1.03, CI (0.93, 1.13)] were all within the no-effect boundary (0.80, 1.25) (bioequivalence criterion). A stable mean insulin detemir concentration with and without liraglutide was maintained at the end of the 24-h PK sampling period. PD: The sum of AUC(GIR) for liraglutide (1982 mg/kg) and insulin detemir (1058 mg/kg) when given alone was similar to that obtained when the two were co-administered (2947 mg/kg). No serious adverse events were reported and no adverse events led to study withdrawal.. Co-administration of liraglutide 1.8 mg at steady state and insulin detemir produces an additive glucose-lowering effect without affecting the PK profile of either therapeutic agent suggesting that the addition of insulin detemir to patients treated with liraglutide will not require titration algorithms different from when insulin is added to OADs. The co-administration of insulin detemir and liraglutide was well tolerated. Topics: Area Under Curve; Diabetes Mellitus, Type 2; Drug Interactions; Drug Therapy, Combination; Female; Glucagon-Like Peptide 1; Humans; Hypoglycemic Agents; Insulin; Insulin Detemir; Insulin, Long-Acting; Liraglutide; Male; Middle Aged; Treatment Outcome | 2011 |
Effects of the soluble fiber complex PolyGlycopleX® (PGX®) on glycemic control, insulin secretion, and GLP-1 levels in Zucker diabetic rats.
The effects of the novel water soluble, viscous fiber complex PolyGlycopleX® [(α-D-glucurono-α-D-manno-β-D-manno-β-D-gluco), (α-L-gulurono-β-D mannurono), β-D-gluco-β-D-mannan (PGX®)] on body weight, food consumption, glucose, insulin, and glucagon-like peptide (GLP-1) levels were determined in Zucker diabetic rats (ZDFs). Such fibers are thought to improve glycemic control through increased GLP-1 induced insulin secretion.. ZDFs were treated 12 weeks with normal rodent chow supplemented with cellulose (control, inert fiber), inulin or PGX® at 5% wt/wt and effects on body weight, glycemic control, and GLP-1 determined.. In the fed state, PGX® reduced blood glucose compared to the other groups from week 5 until study termination while insulin was significantly elevated when measured at week 9, suggesting an insulin secretagogue effect. Fasting blood glucose was similar among groups until 7-8 weeks when levels began to climb with a modest reduction caused by PGX®. An oral glucose tolerance test in fasted animals (week 11) showed no change in insulin sensitivity scores among diets, suggesting an insulinotropic effect for PGX® rather than increased insulin sensitivity. PGX® increased plasma levels of GLP-1, while HbA(1c) was markedly reduced by PGX®. Body weights were not changed despite a significant reduction in food consumption induced by PGX® up to week 8 when the PGX®-treated group showed an increase in body weight despite a continued reduction in food consumption.. PGX® improved glycemic control and reduced protein glycation, most likely due to the insulin secretagogue effects of increased GLP-1. Topics: Alginates; Animal Feed; Animals; Blood Glucose; Body Weight; Cellulose; Diabetes Mellitus, Type 2; Drug Combinations; Eating; Glucagon-Like Peptide 1; Glucose Tolerance Test; Glycated Hemoglobin; Hyperglycemia; Insulin; Male; Polysaccharides, Bacterial; Rats; Rats, Zucker | 2011 |
New aspects of an old drug: metformin as a glucagon-like peptide 1 (GLP-1) enhancer and sensitiser.
The two major deficits in type 2 diabetes, insulin resistance and impaired beta cell function, are often treated with metformin and incretin-based drugs, respectively. However, there may be unappreciated benefits of this combination of therapies. In this issue of Diabetologia, Maida et al. (doi: 10.1007/s00125-010-1937-z) report that metformin acutely increases plasma levels of glucagon-like peptide 1 (GLP-1) in mice. Moreover, they show that metformin enhances the expression of the genes encoding the receptors for both GLP-1 and glucose-dependent insulinotropic polypeptide (GIP) in mouse islets and also increases the effects of GIP and GLP-1 on insulin secretion from beta cells. Interestingly, these incretin-sensitising effects of metformin appear to be mediated by a peroxisome proliferator-activated receptor α-dependent pathway, as opposed to the more commonly ascribed pathway of metformin action involving AMP-activated protein kinase. These provocative findings by Maida et al. extend our understanding of the mechanism of action of metformin and provide further insights into the benefits of combining metformin with incretin-based drugs to combat diabetes. Topics: Animals; Cell Line; Diabetes Mellitus, Type 2; Dipeptidyl Peptidase 4; Eating; Gastric Inhibitory Polypeptide; Glucagon-Like Peptide 1; Glucagon-Like Peptide-1 Receptor; Humans; Hypoglycemic Agents; Male; Metformin; Mice; Mice, Inbred C57BL; Mice, Mutant Strains; Models, Biological; Peptide Fragments; PPAR alpha; Receptors, Gastrointestinal Hormone; Receptors, Glucagon; Signal Transduction | 2011 |
Targeting enteral endocrinal L-cells with dietary carbohydrates, by increasing the availability of miglitol in the intestinal lumen, leads to multi-fold enhancement of plasma glucagon-like peptide-1 levels in non-diabetic canines.
The principle aim of this study was to design a controlled release (CR), bioadhesive formulation of miglitol (in form of pellets) which would regulate the post-prandial glucose levels via reversible inhibition of α-glucosidase enzyme as well as by modulating the glucagon-like peptide-1 (GLP-1) pathway in non-diabetic canines. A multilayered pellet formulation which was both bioadhesive (because of hydroxy propyl methyl cellulose polymer) and CR (because of the ethyl cellulose layer) was formulated. We report a novel finding that the CR formulation of miglitol (S3) induced a 2.2-fold elevation in the C(max) as well as the overall AUC(0-24) of GLP-1 values in comparison to the non-CR (immediate release (IR) formulation). The S3 formulation also resulted in better, steady, and prolonged control of glucose levels over a time period of 7 h in comparison to the IR formulation possibly due to combination of both, prolonged inhibition of the α-glucosidase enzyme and enhanced plasma GLP-1 levels. The S3 formulation was stable with no changes in the dissolution profiles at both of the stability conditions tested, 25°C/60% RH and 40°C/75% RH. Aqueous polymeric coating of the pellets (in contrast to coating using organic solvents) resulted morphologically in a uniform polymeric film and also releases profiles with lower burst effect. Curing played a significant role in determining release profile of the pellets, prepared by aqueous polymeric coating method. Topics: 1-Deoxynojirimycin; alpha-Glucosidases; Animals; Biological Availability; Blood Glucose; Cellulose; Delayed-Action Preparations; Diabetes Mellitus, Type 2; Dietary Carbohydrates; Dogs; Drug Implants; Enteroendocrine Cells; Glucagon-Like Peptide 1; Glycoside Hydrolase Inhibitors; Intestine, Small; Male; Methylcellulose; Polymers; Postprandial Period; Rats; Rats, Sprague-Dawley | 2011 |
Pharmacokinetics and pharmacodynamics of exenatide extended-release after single and multiple dosing.
Exenatide is a glucagon-like peptide-1 receptor agonist, available in an immediate-release (IR), twice-daily formulation, which improves glycaemic control through enhancement of glucose-dependent insulin secretion, suppression of inappropriately elevated postprandial glucagon secretion, slowing of gastric emptying and reduction of food intake. The objectives of these studies were to assess the safety, tolerability, pharmacokinetics and pharmacodynamics of an extended-release (ER) exenatide formulation in patients with type 2 diabetes mellitus.. Patients with type 2 diabetes participated in either a single-dose trial (n = 62) or a repeated-administration trial (n = 45). The pharmacokinetic and safety effects of single-dose subcutaneous administration of exenatide ER (2.5 mg, 5 mg, 7 mg or 10 mg) versus placebo were studied over a period of 12 weeks in patients with type 2 diabetes. These results were used to predict the dose regimen of exenatide ER required to achieve steady-state therapeutic plasma exenatide concentrations. A second clinical study investigated the pharmacokinetics, pharmacodynamics and safety of weekly exenatide ER subcutaneous injections (0.8 mg or 2 mg) versus placebo in patients with type 2 diabetes over a period of 15 weeks. Furthermore, population-based analyses of these studies were performed to further define the exposure-response relationships associated with exenatide ER.. Exenatide exposure increased with dose (2.5 mg, 5 mg, 7 mg or 10 mg) and exhibited a multiple-peak profile over approximately 10 weeks. Multiple-dosing pharmacokinetics were predicted from superpositioning of single-dose data; weekly administration of exenatide ER 0.8 mg and 2 mg for 15 weeks confirmed the predictions. Weekly dosing resulted in steady-state plasma exenatide concentrations after 6-7 weeks. Fasting plasma glucose levels were reduced similarly with both doses after 15 weeks (-42.7 ± 15.7 mg/dL with the 0.8 mg dose and -39.0 ± 9.3 mg/dL with the 2 mg dose; both p < 0.001 vs placebo), and the integrated exposure-response analysis demonstrated that the drug concentration producing 50% of the maximum effect (EC(50)) on fasting plasma glucose was 56.8 pg/mL (a concentration achieved with both the 0.8 mg and 2 mg doses of exenatide ER). The 2 mg dose reduced bodyweight (-3.8 ± 1.4 kg; p < 0.05 vs placebo) and postprandial glucose excursions. Glycosylated haemoglobin (HbA(1c)) levels were reduced with the 0.8 mg dose (-1.4 ± 0.3%; baseline 8.6%) and with the 2 mg dose (-1.7 ± 0.3%; baseline 8.3%) [both p < 0.001 vs placebo]. Adverse events were generally transient and mild to moderate in intensity.. These studies demonstrated that (i) a single subcutaneous dose of exenatide ER resulted in dose-related increases in plasma exenatide concentrations; (ii) single-dose exposure successfully predicted the weekly-dosing exposure, with 0.8 mg and 2 mg weekly subcutaneous doses of exenatide ER eliciting therapeutic concentrations of exenatide; and (iii) weekly dosing with either 0.8 or 2 mg of exenatide ER improved fasting plasma glucose control, whereas only the 2 mg dose was associated with improved postprandial glucose control and weight loss. [Clinicaltrials.gov Identifier: NCT00103935]. Topics: Blood Glucose; Delayed-Action Preparations; Diabetes Mellitus, Type 2; Dose-Response Relationship, Drug; Drug Administration Schedule; Exenatide; Gastric Emptying; Glucagon-Like Peptide 1; Glucagon-Like Peptide-1 Receptor; Humans; Hypoglycemic Agents; Injections, Subcutaneous; Male; Middle Aged; Peptides; Receptors, Glucagon; Venoms | 2011 |
Pharmacokinetic and pharmacodynamic modeling of exendin-4 in type 2 diabetic Goto-Kakizaki rats.
The pharmacokinetics (PK) and pharmacodynamics (PD) of exendin-4 were studied in type 2 diabetic Goto-Kakizaki rats after single doses at 0.5, 1, 5, or 10 μg/kg by intravenous administration and 5 μg/kg by subcutaneous administration. Plasma exendin-4, glucose, and insulin concentrations were determined. A target-mediated drug disposition model was used to characterize the PK of exendin-4. Glucose turnover was described by an indirect response model, with insulin stimulating glucose disposition. Insulin turnover was characterized by an indirect response model with a precursor compartment. After intravenous doses, exendin-4 rapidly disappeared from the circulation, whereas it exhibited rapid absorption (T(max) = 15-20 min) and incomplete bioavailability (F = 0.51) after the subcutaneous dose. Exendin-4 increased insulin release at 2 to 5 min with capacity S(max) = 6.91 and sensitivity SC₅₀ = 1.29 nM, followed by a rebound at 10 to 15 min and a slow return to the baseline. Glucose initially declined because of enhanced insulin secretion, and then gradually increased because of the activation of the neural system by exendin-4. The hyperglycemic action was modeled with increased hepatic glucose production with a linear factor S(RC) = 0.112 1/nM. The mechanistic PK/PD model satisfactorily described the disposition and effects of exendin-4 on glucose and insulin homeostasis in type 2 diabetic rats. Topics: Animals; Blood Glucose; Diabetes Mellitus, Experimental; Diabetes Mellitus, Type 2; Dose-Response Relationship, Drug; Exenatide; Glucagon-Like Peptide 1; Insulin; Male; Models, Molecular; Peptides; Rats; Venoms | 2011 |
Taspoglutide, a novel human once-weekly GLP-1 analogue, protects pancreatic β-cells in vitro and preserves islet structure and function in the Zucker diabetic fatty rat in vivo.
Glucagon-like peptide-1 (GLP-1) has protective effects on pancreatic β-cells. We evaluated the effects of a novel, long-acting human GLP-1 analogue, taspoglutide, on β-cells in vitro and in vivo.. Proliferation of murine pancreatic β (MIN6B1) cells and rat islets in culture was assessed by imaging of 5-ethynyl-2'-deoxyuridine-positive cells after culture with taspoglutide. Apoptosis was evaluated with the transferase-mediated 2'-deoxyuridine 5'-triphosphate nick-end labelling assay in rat insulinoma (INS-1E) cells and isolated human islets exposed to cytokines (recombinant interleukin-1β, interferon-γ, tumour necrosis factor-α) or lipotoxicity (palmitate) in the presence or absence of taspoglutide. Islet morphology and survival and glucose-stimulated insulin secretion in perfused pancreata were assessed 3-4 weeks after a single application of taspoglutide to prediabetic 6-week-old male Zucker diabetic fatty (ZDF) rats.. Proliferation was increased in a concentration-dependent manner up to fourfold by taspoglutide in MIN6B1 cells and was significantly stimulated in isolated rat islets. Taspoglutide almost completely prevented cytokine- or lipotoxicity-induced apoptosis in INS-1E cells (control 0.5%, cytokines alone 2.2%, taspoglutide + cytokines 0.6%, p < 0.001; palmitate alone 8.1%, taspoglutide + palmitate 0.5%, p < 0.001) and reduced apoptosis in isolated human islets. Treatment of ZDF rats with taspoglutide significantly prevented β-cell apoptosis and preserved healthy islet architecture and insulin staining intensity as shown in pancreatic islet cross sections. Basal and glucose-stimulated insulin secretion of in situ perfused ZDF rat pancreata was normalized after taspoglutide treatment.. Taspoglutide promoted β-cell proliferation, prevented apoptosis in vitro and exerted multiple β-cell protective effects on islet architecture and function in vivo in ZDF rats. Topics: Animals; Apoptosis; Cells, Cultured; Deoxyuridine; Diabetes Mellitus, Type 2; Glucagon-Like Peptide 1; Glucagon-Like Peptide-1 Receptor; Humans; Immunohistochemistry; Insulin-Secreting Cells; Male; Peptides; Rats; Rats, Zucker; Receptors, Glucagon | 2011 |
Sustained glucagon-like peptide 1 expression from encapsulated transduced cells to treat obese diabetic rats.
Obesity and type 2 diabetes (T2D) are two prevalent chronic diseases that have become a major public health concern in industrialized countries. T2D is characterized by hyperglycemia and islet beta cell dysfunction. Glucagon-like peptide 1 (GLP-1) promotes β cell proliferation and neogenesis and has a potent insulinotropic effect. Leptin receptor deficient male rats are obese and diabetic and provide a model of T2D. We hypothesized that their treatment by sustained expression of GLP-1 using encapsulated cells may prevent or delay diabetes onset. Vascular smooth muscle cells (VSMC) retrovirally transduced to secrete GLP-1 were seeded into TheraCyte(TM) encapsulation devices, implanted subcutaneously and rats were monitored for diabetes. Rats that received cell implants showed mean plasma GLP-1 level of 119.3 ± 10.2pM that was significantly elevated over control values of 32.4 ± 2.9pM (P<0.001). GLP-1 treated rats had mean insulin levels of 45.9 ± 2.3ng/ml that were significantly increased over control levels of 7.3±1.5ng/ml (P<0.001). In rats treated before diabetes onset elevations in blood glucose were delayed and rats treated after onset became normoglycemic and showed improved glucose tolerance tests. Untreated diabetic rats possess abnormal islet structures characterized by enlarged islets with α-cell infiltration and multifocal vacuolization. GLP-1 treatment induced normalization of islet structures including a mantle of α-cells and increased islet mass. These data suggest that encapsulated transduced cells may offer a potential long term treatment of patients. Topics: Animals; Blood Glucose; Diabetes Mellitus, Type 2; Glucagon; Glucagon-Like Peptide 1; Glucose Tolerance Test; Insulin; Insulin-Secreting Cells; Islets of Langerhans; Male; Muscle, Smooth, Vascular; Obesity; Rats; Rats, Wistar; Receptors, Leptin; Transduction, Genetic | 2011 |
Impaired regulation of the incretin effect in patients with type 2 diabetes.
In healthy subjects, the incretin effect during an oral glucose tolerance test increases with the size of glucose load, resulting in similar glucose excursions independently of the glucose loads. Whether patients with type 2 diabetes mellitus (T2DM) are able to regulate their incretin effect is unknown.. Incretin effect was measured over 6 d by means of three 4-h oral glucose tolerance test with increasing glucose loads (25, 75, and 125 g) and three corresponding isoglycemic iv glucose infusions in eight patients with T2DM [fasting plasma glucose, mean 7.7 (range 7.0-8.9) mM; glycosylated hemoglobin, 7.0% (6.2-8.4%)] and eight matched healthy control subjects [fasting plasma glucose, 5.3 (4.8-5.7) mM; glycosylated hemoglobin, 5.4% (5.0-5.7%)].. Patients with T2DM exhibited higher peak plasma glucose in response to increasing oral glucose loads, whereas no differences in peak plasma glucose values among control subjects were observed. The incretin effect was significantly (P < 0.003) lower in patients with T2DM (0 ± 7, 11 ± 9, and 36 ± 5%) as compared with control subjects (36 ± 5, 53 ± 6, and 65 ± 6%). Equal and progressively delayed gastric emptying due to the increasing loads was found in both groups. Incretin hormone responses were similar.. Up-regulation of the incretin effect in response to increasing oral glucose loads seems to be crucial for controlling glucose excursions in healthy subjects. Patients with T2DM are characterized by an impaired capability to regulate their incretin effect, which may contribute to the exaggerated glucose excursions after oral ingestion of glucose in these patients. Topics: Acetaminophen; Adult; Aged; Analgesics, Non-Narcotic; Area Under Curve; Blood Glucose; C-Peptide; Diabetes Mellitus, Type 2; Female; Gastric Emptying; Gastric Inhibitory Polypeptide; Glucagon-Like Peptide 1; Glucose; Glucose Tolerance Test; Glycated Hemoglobin; Humans; Incretins; Insulin; Insulin Secretion; Insulin-Secreting Cells; Male; Middle Aged | 2011 |
An analysis of the impact of FDA's guidelines for addressing cardiovascular risk of drugs for type 2 diabetes on clinical development.
We examined the impact of FDA's 2008 guidelines for addressing cardiovascular risks of new therapies for type 2 diabetes on clinical trials. We focused on the new class of incretin-modulating drugs, exenatide, sitagliptin, saxagliptin and liraglutide, which were approved in 2005-2010. We contrasted these findings with those from 2 different groups: 1. diabetes drugs approved in the same timeframe but with a non-incretin mechanism of action (colesevelam HCl and bromocriptine mesylate) and 2. diabetes drugs with NDAs delayed and not yet approved within the same time frame (vildagliptin, alogliptin, insulin inhalation powder, and exenatide long acting release). The new guidelines have had an important impact on clinical development. Review time has increased over 2-fold. The increase is seen even if a drug with the same mechanism of action has been already approved. Whereas exenatide (approved in 2005) required 10 months of regulatory review, the approval of liraglutide in 2010 required more than twice as long (21 months). In contrast, the marketing authorization of liraglutide in the EU required 14 months. Additionally, the manufacturer of vildagliptin announced in June 2008, 30 months after the NDA was filed, that a re-submission to meet FDA's demands was not planned. The drug however received marketing authorization in the EU in 2007. The number of randomized patients and patient-years in NDAs increased more than 2.5 and 4 fold, respectively since the guidelines. The significant cost increases and negative publicity because of rare adverse reactions will adversely affect future clinical research in type 2 diabetes and not address its burgeoning health care impact. Topics: Adamantane; Allylamine; Cardiovascular Diseases; Colesevelam Hydrochloride; Diabetes Mellitus, Type 2; Dipeptides; Dipeptidyl-Peptidase IV Inhibitors; Exenatide; Glucagon-Like Peptide 1; Humans; Hypoglycemic Agents; Incretins; Insulin; Investigational New Drug Application; Liraglutide; Nitriles; Peptides; Piperidines; Practice Guidelines as Topic; Pyrazines; Pyrrolidines; Randomized Controlled Trials as Topic; Sitagliptin Phosphate; Time Factors; Triazoles; United States; United States Food and Drug Administration; Uracil; Venoms; Vildagliptin | 2011 |
Duodenal-jejunal bypass protects GK rats from {beta}-cell loss and aggravation of hyperglycemia and increases enteroendocrine cells coexpressing GIP and GLP-1.
Dramatic improvement of type 2 diabetes is commonly observed after bariatric surgery. However, the mechanisms behind the alterations in glucose homeostasis are still elusive. We examined the effect of duodenal-jejunal bypass (DJB), which maintains the gastric volume intact while bypassing the entire duodenum and the proximal jejunum, on glycemic control, β-cell mass, islet morphology, and changes in enteroendocrine cell populations in nonobese diabetic Goto-Kakizaki (GK) rats and nondiabetic control Wistar rats. We performed DJB or sham surgery in GK and Wistar rats. Blood glucose levels and glucose tolerance were monitored, and the plasma insulin, glucagon-like peptide-1 (GLP-1), and glucose-dependent insulinotropic polypeptide (GIP) levels were measured. β-Cell area, islet fibrosis, intestinal morphology, and the density of enteroendocrine cells expressing GLP-1 and/or GIP were quantified. Improved postprandial glycemia was observed from 3 mo after DJB in diabetic GK rats, persisting until 12 mo after surgery. Compared with the sham-GK rats, the DJB-GK rats had an increased β-cell area and a decreased islet fibrosis, increased insulin secretion with increased GLP-1 secretion in response to a mixed meal, and an increased population of cells coexpressing GIP and GLP-1 in the jejunum anastomosed to the stomach. In contrast, DJB impaired glucose tolerance in nondiabetic Wistar rats. In conclusion, although DJB worsens glucose homeostasis in normal nondiabetic Wistar rats, it can prevent long-term aggravation of glucose homeostasis in diabetic GK rats in association with changes in intestinal enteroendocrine cell populations, increased GLP-1 production, and reduced β-cell deterioration. Topics: Animals; Bariatric Surgery; Blood Glucose; Body Composition; Body Weight; Diabetes Mellitus, Type 2; Duodenum; Endocrine System; Enzyme-Linked Immunosorbent Assay; Fibrosis; Gastric Inhibitory Polypeptide; Glucagon-Like Peptide 1; Glucose Tolerance Test; Hyperglycemia; Immunohistochemistry; Incretins; Insulin-Secreting Cells; Islets of Langerhans; Jejunum; Male; Rats; Rats, Wistar | 2011 |
Plasma levels of glucagon like peptide-1 associate with diastolic function in elderly men.
Congestive heart failure is a major cause of morbidity and mortality in diabetes. Besides the glycaemic effects of glucagon-like peptide 1 (GLP-1) mimetics, their effects on the heart are of interest.. We aimed to investigate longitudinal relationships between plasma levels of fasting GLP-1 (fGLP-1), 60-min oral glucose tolerance test-stimulated GLP-1 levels (60GLP-1), and the dynamic GLP-1 response after oral glucose tolerance test (ΔGLP-1 = 60GLP-1 - fGLP-1) and incidence of hospitalized congestive heart failure, during a follow-up time of a maximum of 9.8 years in 71-year-old men. We also investigated, cross-sectionally, the association between GLP-1 and left ventricular function as estimated by echocardiography. R: During the follow-up period, 16 of 290 participants with normal glucose tolerance experienced a congestive heart failure event (rate 0.7/100 person-years at risk), as did eight of 136 participants (rate 0.8/100 person-years at risk) with impaired glucose tolerance and nine of 72 participants (rate 1.7/100 person-years at risk) with Type 2 diabetes mellitus. Although GLP-1 concentrations did not predict congestive heart failure (fGLP-1: HR 0.98, 95% CI 0.4-2.4; 60GLP-1: HR 1.1, 95% CI 0.4-2.6; ΔGLP-1: HR 0.9, 95% CI 0.3-2.3), there was an association between left ventricular diastolic function (E/A ratio) and fGLP-1 (r = 0.19, P = 0.001), 60GLP-1 (r = 0.20, P < 0.001) and ΔGLP-1 (r = 0.18, P = 0.004). There was a lack of differences in plasma levels of GLP-1 between the groups with Type 2 diabetes and normal glucose tolerance.. There were no longitudinal associations between GLP-1 levels and incidence of hospitalization for congestive heart failure. However, without any causality proven, GLP-1 levels did correlate, cross-sectionally, with left ventricular diastolic function in this cohort, suggesting that pathways including GLP-1 might be involved in the regulation of cardiac diastolic function. Topics: Aged, 80 and over; Cross-Sectional Studies; Diabetes Mellitus, Type 2; Diastole; Fasting; Glucagon-Like Peptide 1; Glucose Clamp Technique; Glucose Tolerance Test; Heart Failure; Humans; Male; Prospective Studies; Survival Analysis | 2011 |
Novel GLP-1 mimetics developed to treat type 2 diabetes promote progenitor cell proliferation in the brain.
One of the symptoms of diabetes is the progressive development of neuropathies. One mechanism to replace neurons in the CNS is through the activation of stem cells and neuronal progenitor cells. We have tested the effects of the novel GLP-1 mimetics exenatide (exendin-4; Byetta) and liraglutide (NN2211; Victoza), which are already on the market as treatments for type 2 diabetes, on the proliferation rate of progenitor cells and differentiation into neurons in the dentate gyrus of brains of mouse models of diabetes. GLP-1 analogues were injected subcutaneously for 4, 6, or 10 weeks once daily in three mouse models of diabetes: ob/ob mice, db/db mice, or high-fat-diet-fed mice. Twenty-four hours before perfusion, animals were injected with 5'-bromo-2'-deoxyuridine (BrdU) to mark dividing progenitor cells. By using immunohistochemistry and stereological methods, the number of progenitor cells or doublecortin-positive young neurons in the dentate gyrus was estimated. We found that, in all three mouse models, progenitor cell division was enhanced compared with nondiabetic controls after chronic i.p. injection of either liraglutide or exendin-4 by 100-150% (P < 0.001). We also found an increase in young neurons in the DG of high-fat-diet-fed mice after drug treatment (P < 0.001). The GLP-1 receptor antagonist exendin(9-36) reduced progenitor cell proliferation in these mice. The results demonstrate that GLP-1 mimetics show promise as a treatment for neurodegenerative diseases such as Alzheimer's disease, because these novel drugs cross the blood-brain barrier and increase neuroneogenesis. Topics: Animals; Brain; Cell Differentiation; Cell Proliferation; Dentate Gyrus; Diabetes Mellitus, Type 2; Disease Models, Animal; Exenatide; Glucagon-Like Peptide 1; Hypoglycemic Agents; Immunohistochemistry; Liraglutide; Male; Mice; Neural Stem Cells; Neurogenesis; Neurons; Peptides; Venoms | 2011 |
Glucagon-like peptide-1 analogues for type 2 diabetes.
Topics: Diabetes Mellitus, Type 2; Exenatide; Female; Glucagon-Like Peptide 1; Humans; Hypoglycemic Agents; Liraglutide; Middle Aged; Peptides; Venoms | 2011 |
Pharmacotherapy: GLP-1 analogues and insulin: sound the wedding bells?
Topics: Animals; Diabetes Mellitus, Type 2; Exenatide; Glucagon-Like Peptide 1; Humans; Hypoglycemic Agents; Insulin; Insulin Glargine; Insulin, Long-Acting; Metformin; Peptides; Pioglitazone; Randomized Controlled Trials as Topic; Thiazolidinediones; Venoms | 2011 |
Which oral agent to use when metformin is no longer effective?
Topics: Administration, Oral; Diabetes Mellitus, Type 2; Dipeptidyl-Peptidase IV Inhibitors; Drug Tolerance; Glucagon-Like Peptide 1; Humans; Hypoglycemic Agents; Metformin; Sulfonylurea Compounds; Thiazolidinediones; Weight Gain | 2011 |
Administration of an acylated GLP-1 and GIP preparation provides added beneficial glucose-lowering and insulinotropic actions over single incretins in mice with Type 2 diabetes and obesity.
The present study examined the glucose-lowering and insulinotropic properties of acylated GLP-1 (glucagon-like peptide-1) and GIP (glucose-dependent insulinotropic polypeptide) peptides in Type 2 diabetes and obesity. GLP-1, GIP, Liraglutide, N-AcGIP(Lys(37)Myr) (N-acetylGIP with myristic acid conjugated at Lys(37)), a simple combination of both peptides and a Lira-AcGIP preparation [overnight preparation of Liraglutide and N-AcGIP(Lys(37)Myr)] were incubated with DPP-IV (dipeptidyl peptidase-IV) to assess peptide stability, and BRIN-BD11 cells were used to evaluate cAMP production and insulin secretion. Acute glucose-lowering and insulinotropic actions were evaluated in Swiss TO mice. Subchronic studies on glucose homoeostasis, insulin secretion, food intake and bodyweight were evaluated in ob/ob mice. Liraglutide, N-AcGIP(Lys(37)Myr), a simple combination of both peptides and the Lira-AcGIP preparation demonstrated improved DPP-IV resistance (P<0.001), while stimulating cAMP production and insulin secretion (1.4-2-fold; P<0.001). The Lira-AcGIP preparation was more potent at lowering plasma glucose (20-51% reduction; P<0.05-P<0.001) and stimulating insulin secretion (1.5-1.8-fold; P<0.05-P<0.001) compared with Liraglutide and N-AcGIP(Lys(37)Myr) or a simple peptide combination. Daily administration of the Lira-AcGIP preparation to ob/ob mice lowered bodyweight (7-9%; P<0.05), food intake (23%; P<0.05) and plasma glucose (46% reduction; P<0.001), while increasing plasma insulin (1.5-1.6-fold; P<0.001). The Lira-AcGIP preparation enhanced glucose tolerance, insulin response to glucose and insulin content (P<0.05-P<0.001). These findings demonstrate that a combined preparation of the acylated GLP-1 and GIP peptides Liraglutide and N-AcGIP(Lys(37)Myr) markedly improved glucose-lowering and insulinotropic properties in diabetic obesity compared with either incretin mimetic given individually. Topics: Animals; Diabetes Mellitus, Type 2; Gastric Inhibitory Polypeptide; Glucagon-Like Peptide 1; Glucose; Incretins; Insulin; Insulin-Secreting Cells; Liraglutide; Male; Mice; Mice, Obese; Models, Biological; Obesity | 2011 |
Sitagliptin lowers glucagon and improves glucose tolerance in prediabetic obese SHROB rats.
The SHROB (spontaneously hypertensive rat - obese strain) is a model of prediabetes and metabolic syndrome with insulin resistance, glucose intolerance and hypertension. Inhibitors of dipeptidyl dipeptidase IV (DPP-IV) are effective hypoglycemic agents in type 2 diabetes through potentiation of incretin hormones that act in the pancreas to increase insulin and decrease glucagon release. We sought to determine whether the DPP-IV inhibitor sitagliptin might be effective in prediabetes relative to standard therapy with the sulfonylurea glyburide, by using the SHROB model. SHROB show normal fasting glucose but are insulin resistant and hyperglucagonemic. SHROB were treated for six weeks with vehicle, sitagliptin (30 mg/kg/d) or glyburide (1 mg/kg/d) and compared with untreated lean spontaneously hypertensive rats. Body weight, food intake and fasting glucose were all unchanged in all three SHROB groups, but glucagon was reduced by 33% by sitagliptin while remaining unchanged following glyburide or vehicle. In oral glucose (6 g/kg) tolerance testing, both sitagliptin and glyburide lowered plasma glucose. Both sitagliptin and glyburide shifted peak insulin secretion earlier (30 min for glyburide and 60 min for sitagliptin but 240 min for vehicle). Only sitagliptin significantly enhanced insulin secretion. Sitagliptin is effective in normalizing excess glucagon levels and delaying exaggerated insulin secretion in response to a glucose challenge in a prediabetic model. Topics: Animals; Blood Glucose; Body Weight; Diabetes Mellitus, Type 2; Disease Models, Animal; Feeding Behavior; Glucagon; Glucagon-Like Peptide 1; Glyburide; Hypoglycemic Agents; Insulin; Insulin Secretion; Pyrazines; Rats; Sitagliptin Phosphate; Triazoles | 2011 |
Chronic administration of ezetimibe increases active glucagon-like peptide-1 and improves glycemic control and pancreatic beta cell mass in a rat model of type 2 diabetes.
Ezetimibe is a cholesterol-lowering agent targeting Niemann-Pick C1-like 1, an intestinal cholesterol transporter. Inhibition of intestinal cholesterol absorption with ezetimibe may ameliorate several metabolic disorders including hepatic steatosis and insulin resistance. In this study, we investigated whether chronic ezetimibe treatment improves glycemic control and pancreatic beta cell mass, and alters levels of glucagon-like peptide-1 (GLP-1), an incretin hormone involved in glucose homeostasis. Male LETO and OLETF rats were treated with vehicle or ezetimibe (10 mg kg(-1)day(-1)) for 20 weeks via stomach gavage. OLETF rats were diabetic with hyperglycemia and significant decreases in pancreatic size and beta cell mass compared with LETO lean controls. Chronic treatment of OLETF rats with ezetimibe improved glycemic control during oral glucose tolerance test compared with OLETF controls. Moreover, ezetimibe treatment rescued the reduced pancreatic size and beta cell mass in OLETF rats. Interestingly, ezetimibe significantly decreased serum dipeptidyl peptidase-4 activity and increased serum active GLP-1 in OLETF rats without altering serum total GLP-1. These findings demonstrated that chronic administration of ezetimibe improves glycemic control and pancreatic beta cell mass, and increases serum active GLP-1 levels, suggesting possible involvement of GLP-1 in the ezetimibe-mediated beneficial effects on glycemic control. Topics: Animals; Anticholesteremic Agents; Azetidines; Blood Glucose; Diabetes Mellitus, Experimental; Diabetes Mellitus, Type 2; Ezetimibe; Glucagon-Like Peptide 1; Hyperglycemia; Insulin-Secreting Cells; Male; Rats; Rats, Inbred Strains | 2011 |
Role of the foregut in the early improvement in glucose tolerance and insulin sensitivity following Roux-en-Y gastric bypass surgery.
Bypass of the foregut following Roux-en-Y gastric bypass (RYGB) surgery results in altered nutrient absorption, which is proposed to underlie the improvement in glucose tolerance and insulin sensitivity. We conducted a prospective crossover study in which a mixed meal was delivered orally before RYGB (gastric) and both orally (jejunal) and by gastrostomy tube (gastric) postoperatively (1 and 6 wk) in nine subjects. Glucose, insulin, and incretin responses were measured, and whole-body insulin sensitivity was estimated with the insulin sensitivity index composite. RYGB resulted in an improved glucose, insulin, and glucagon-like peptide-1 (GLP-1) area under the curve (AUC) in the first 6 wk postoperatively (all P ≤ 0.018); there was no effect of delivery route (all P ≥ 0.632) or route × time interaction (all P ≥ 0.084). The glucose-dependent insulinotropic polypeptide (GIP) AUC was unchanged after RYGB (P = 0.819); however, GIP levels peaked earlier after RYGB with jejunal delivery. The ratio of insulin AUC to GLP-1 and GIP AUC decreased after surgery (P =.001 and 0.061, respectively) without an effect of delivery route over time (both P ≥ 0.646). Insulin sensitivity improved post-RYGB (P = 0.001) with no difference between the gastric and jejunal delivery of the mixed meal over time (P = 0.819). These data suggest that exclusion of nutrients from the foregut with RYGB does not improve glucose tolerance or insulin sensitivity. However, changes in the foregut response post-RYGB due to lack of nutrient exposure cannot be excluded. Our findings suggest that foregut bypass may alter the incretin response by enhanced nutrient delivery to the hindgut. Topics: Adult; Anastomosis, Roux-en-Y; Area Under Curve; Blood Glucose; Body Weight; Diabetes Mellitus, Type 2; Duodenum; Female; Food; Gastric Bypass; Ghrelin; Glucagon-Like Peptide 1; Glucose Tolerance Test; Humans; Incretins; Insulin; Insulin Resistance; Jejunum; Laparoscopy; Male; Metabolism; Middle Aged | 2011 |
The dynamic incretin adaptation and type 2 diabetes.
Topics: Adaptation, Physiological; Diabetes Mellitus, Type 2; Gastric Inhibitory Polypeptide; Glucagon-Like Peptide 1; Glucose; Humans; Hypoglycemic Agents; Incretins | 2011 |
Antidiabetic effects of duodenojejunal bypass in an experimental model of diabetes induced by a high-fat diet.
Obese patients with type II diabetes who undergo bariatric surgery revert to normal blood glucose and insulin levels, and develop a dramatic increase in insulin sensitivity. However, the mechanisms involved are unknown. This study characterized pancreatic islet and duodenojejunal enteroendocrine cells in normal mice and those with diabetes induced by a high-fat diet (HFD) following duodenojejunal bypass (DJB).. C57BL/6J mice, fed for 8 weeks either a normal diet (n = 10) or a HFD (n = 10) resulting in a hyperglycaemic state, underwent DJB (connection of the distal end of the jejunum to the distal stomach and direction of biliopancreatic secretions to the distal jejunum). Metabolic and immunohistological analyses were carried out on the pancreas and gastrointestinal tract.. A significant decrease in fasting blood glucose was observed in normal-DJB and HFD-DJB mice 1 week after the operation, with improved glucose tolerance at 4 weeks. There were no changes in pancreatic β-cell mass, but an increase in the ratio of α-cell to β-cell mass was observed in the DJB groups. Furthermore, the number of cells expressing Pdx-1, glucagon-like peptide 1, pancreatic polypeptide and synaptophysin was increased in the bypassed duodenum and/or gastrojejunum of the DJB groups.. Both normal and obese diabetic mice that underwent DJB displayed improved glucose tolerance and a reduction in fasting blood glucose, which mimicked findings in obese diabetic patients following bariatric surgery. The present data suggest that an increase in specific enteroendocrine cell populations may play a critical role in normalizing glucose homeostasis. Topics: Anastomosis, Surgical; Animals; Blood Glucose; Body Weight; Cholecystokinin; Diabetes Mellitus, Type 2; Diet; Dietary Fats; Duodenum; Eating; Fluorescent Antibody Technique; Glucagon-Like Peptide 1; Homeodomain Proteins; Homeostasis; Islets of Langerhans; Jejunum; Mice; Mice, Inbred C57BL; Mice, Obese; Trans-Activators | 2011 |
Association of TCF7L2 SNPs with age at onset of type 2 diabetes and proinsulin/insulin ratio but not with glucagon-like peptide 1.
Variants in TCF7L2 have been associated with the age at onset of type 2 diabetes in Mexican Americans. However, there is a lack of data on this relationship in Caucasians. Furthermore, risk alleles in TCF7L2 have been suggested to account for decreased conversion of proinsulin to insulin and decreased expression of GLP-1. We investigated the effect of the allelic variants rs1225537 and rs7903146 in TCF7L2 on the age at onset of type 2 diabetes, the plasma concentrations of proinsulin and GLP-1, and the ratio of proinsulin to insulin in a German cohort.. We studied 3185 participants of the LUdwigshafen RIsk and Cardiovascular health (LURIC) study. Among these, 1021 subjects had type 2 diabetes. Data on age at onset of diabetes were available in 925 subjects. OGTTs were performed in a subgroup not previously known to have diabetes.. Carriers of the risk alleles in rs1225537 and rs7901346 had increased risk of type 2 diabetes and elevated HbA(1c) (all p < 0.001). The risk alleles were also associated with early onset of type 2 diabetes, decreased insulin secretion and markedly increased proinsulin and proinsulin to insulin ratio (all p < 0.03). GLP-1 was not significantly related to the TCF7L2 genotype.. Our data demonstrate that TCF7L2 variants are associated with an early age of onset of type 2 diabetes in Caucasians and affects the conversion of proinsulin to insulin. However, TCF7L2 is not consistently associated with fasting GLP-1. Topics: Age of Onset; Aged; Diabetes Mellitus, Type 2; Female; Glucagon-Like Peptide 1; Glucose Tolerance Test; Glycated Hemoglobin; Humans; Insulin; Insulin Secretion; Male; Middle Aged; Polymorphism, Single Nucleotide; Proinsulin; Risk; Transcription Factor 7-Like 2 Protein; White People | 2011 |
Glucagon-like peptide-1 drugs. Use of GLP-1 analogues needs great caution.
Topics: Diabetes Mellitus, Type 2; Diabetic Angiopathies; Glucagon-Like Peptide 1; Glycated Hemoglobin; Humans; Hypoglycemic Agents | 2011 |
Glucagon-like peptide-1 drugs. Are GLP-1 analogues affordable?
Topics: Diabetes Mellitus, Type 2; Drug Costs; Glucagon-Like Peptide 1; Humans; Hypoglycemic Agents | 2011 |
The separate and combined impact of the intestinal hormones, GIP, GLP-1, and GLP-2, on glucagon secretion in type 2 diabetes.
Type 2 diabetes mellitus (T2DM) is associated with reduced suppression of glucagon during oral glucose tolerance test (OGTT), whereas isoglycemic intravenous glucose infusion (IIGI) results in normal glucagon suppression in these patients. We examined the role of the intestinal hormones glucose-dependent insulinotropic polypeptide (GIP), glucagon-like peptide-1 (GLP-1), and glucagon-like peptide-2 (GLP-2) in this discrepancy. Glucagon responses were measured during a 3-h 50-g OGTT (day A) and an IIGI (day B) in 10 patients with T2DM [age (mean ± SE), 51 ± 3 yr; body mass index, 33 ± 2 kg/m(2); HbA(1c), 6.5 ± 0.2%]. During four additional IIGIs, GIP (day C), GLP-1 (day D), GLP-2 (day E) and a combination of the three (day F) were infused intravenously. Isoglycemia during all six study days was obtained. As expected, no suppression of glucagon occurred during the initial phase of the OGTT, whereas significantly (P < 0.05) lower plasma levels of glucagon during the first 30 min of the IIGI (day B) were observed. The glucagon response during the IIGI + GIP + GLP-1 + GLP-2 infusion (day F) equaled the inappropriate glucagon response to OGTT (P = not significant). The separate GIP infusion (day C) elicited significant hypersecretion of glucagon, whereas GLP-1 infusion (day D) resulted in enhancement of glucagon suppression during IIGI. IIGI + GLP-2 infusion (day E) resulted in a glucagon response in the midrange between the glucagon responses to OGTT and IIGI. Our results indicate that the intestinal hormones, GIP, GLP-1, and GLP-2, may play a role in the inappropriate glucagon response to orally ingested glucose in T2DM with, especially, GIP, acting to increase glucagon secretion. Topics: Blood Glucose; C-Peptide; Diabetes Mellitus, Type 2; Female; Gastric Inhibitory Polypeptide; Glucagon; Glucagon-Like Peptide 1; Glucagon-Like Peptide 2; Glucose Tolerance Test; Humans; Incretins; Insulin; Insulin-Secreting Cells; Male; Middle Aged; Peptides | 2011 |
Liraglutide therapy in Prader-Willi syndrome.
Topics: Adolescent; Diabetes Mellitus, Type 2; Drug Therapy, Combination; Female; Glucagon-Like Peptide 1; Humans; Liraglutide; Metformin; Obesity, Morbid; Prader-Willi Syndrome; Treatment Outcome | 2011 |
Clinical efficacy of GLP-1 agonists and their place in the diabetes treatment algorithm.
Incretin-based therapies (subcutaneously administered glucagon-like peptide-1 [GLP-1] agonists and oral dipeptidyl peptidase-4 inhibitors) represent a new mechanism of action with which to target the adverse effects of type 2 diabetes mellitus. Both classes of incretins are excellent choices for patients who have jobs that do not permit use of insulin therapy, who have hypoglycemic unawareness, or for whom hypoglycemia is an especially worrisome potential adverse effect. Glucagon-like peptide-1 agonists are an attractive choice for patients in whom promotion of weight loss is a major consideration and the glycated hemoglobin level is moderately elevated (<8.0%) (ie, insulin is not required). Short-acting exenatide has been available since 2005 and is administered twice a day before meals. Liraglutide is the first of the long-acting GLP-1 agonists to be approved in the United States and is administered once a day. The most common adverse effects of GLP-1 agonists are those related to the gastrointestinal system. Both exenatide and liraglutide are associated with weight loss when used as monotherapy or as part of combination-therapy strategies. Glucagon-like peptide-1 agonists also have beneficial effects on cardiovascular risk factors such as blood pressure and lipids. Topics: Administration, Oral; Algorithms; Diabetes Mellitus, Type 2; Dipeptidyl-Peptidase IV Inhibitors; Drug Therapy, Combination; Glucagon-Like Peptide 1; Humans; Hypoglycemic Agents; Incretins; Osteopathic Physicians; Treatment Outcome | 2011 |
The effect of liraglutide added to U-500 insulin in patients with type 2 diabetes and high insulin requirements.
Patients with insulin-treated type 2 diabetes and high insulin requirements are subject to undesirable treatment-related weight gain. These patients would potentially benefit from the insulin-sparing and weight loss benefits of glucagon-like peptide 1 (GLP-1) receptor agonist therapy; however, GLP-1 receptor agonists currently are not approved for use in combination with insulin. We examined the effects of adding liraglutide at a daily dose of 1.2 or 1.8 mg to an intensive regimen (either multiple daily injections or continuous subcutaneous insulin infusion) of U-500 insulin on hemoglobin A1c (HbA1c), total daily insulin dose, and weight in 15 patients with type 2 diabetes and high insulin requirements (initial mean daily insulin dose of 192 ± 77 units per day; initial mean weight, 300.9 ± 55.7 lbs) in a clinical practice setting.. In this observational case series, we identified 15 patients treated with a combination of U-500 insulin and liraglutide for at least 12 weeks at routine follow-up office visits. The U-500 insulin dose was reduced by 0-30% upon initiation of liraglutide. Insulin doses were subsequently adjusted to optimize glycemic control. Endpoints included change in HbA1c, change in total daily insulin dose, change in weight, and incidence of hypoglycemia. Comparisons of 12-week and baseline values were evaluated by paired two-tailed t tests.. At 12 weeks, the reduction in HbA1c from baseline (8.48%) was 1.4% (P = 0.0001). Weight fell by an average of 11.2 LB (5.1 KG) (P = 0.0001). Total daily insulin dose was reduced by 28% (P = 0.0001). No severe episodes of hypoglycemia occurred.. Adding liraglutide to U-500 insulin resulted in significant improvements in glycemic control, weight loss, and reduced insulin requirements in patients with type 2 diabetes and high insulin requirements. Topics: Body Mass Index; Cohort Studies; Diabetes Mellitus, Type 2; Drug Therapy, Combination; Female; Glucagon-Like Peptide 1; Glucagon-Like Peptide-1 Receptor; Glycated Hemoglobin; Humans; Hypoglycemia; Hypoglycemic Agents; Insulin; Insulin Resistance; Liraglutide; Male; Medical Records; Middle Aged; Obesity; Receptors, Glucagon; Retrospective Studies; Severity of Illness Index; Weight Loss | 2011 |
GLP-1 agonists: improving the future of patients with type 2 diabetes.
Topics: Diabetes Mellitus, Type 2; Glucagon-Like Peptide 1; Humans; Incretins | 2011 |
Characteristic of GLP-1 effects on glucose metabolism in human skeletal muscle from obese patients.
Direct effects of GLP-1, kinase-mediated, on glucose and lipid metabolism in rat and human extrapancreatic tissues, are amply documented and also changes in type-2 diabetic (T2D) patients. Here, we explored the characteristics of the GLP-1 action and those of its analogs Ex-4 and Ex-9, on muscle glucose transport (GT) and metabolism in human morbid obesity (OB), as compared with normal and T2D subjects. In primary cultured myocytes from OB, GT and glycogen synthase a (GSa) activity values were lower than normal, and comparable to those reported in T2D patients; GT was increased by either GLP-1 or Ex-9 in a more efficient manner than in normal or T2D, up to normal levels; the Ex-4 increasing effect on GSa activity was two times that in normal cells, while Ex-9 failed to modify the enzyme activity. In OB, the control value of all kinases analyzed - PI3K, PKB, MAPKs, and p70s6K - although lower than that in normal or T2D subjects, the cells maintained their response capability to GLP-1, Ex-4, Ex-9 and insulin, with some exceptions. GLP-1 and exendins showed a direct normalizing action in the altered glucose uptake and metabolism in the muscle of obese subjects, which in the case of GLP-1 could account, at least in part, for the reported restoration of the metabolic conditions of these patients after restrictive surgery. Topics: Adult; Aged, 80 and over; Cells, Cultured; Diabetes Mellitus, Type 2; Female; Glucagon-Like Peptide 1; Glucose; Humans; Male; Muscle, Skeletal; Obesity, Morbid; Peptide Fragments | 2011 |
Understanding the incretin effect.
Topics: Adamantane; Animals; Blood Glucose; Comprehension; Diabetes Mellitus, Type 2; Dipeptidyl Peptidase 4; Dipeptidyl-Peptidase IV Inhibitors; Gastric Inhibitory Polypeptide; Glucagon-Like Peptide 1; Humans; Incretins; Nitriles; Pyrrolidines; Randomized Controlled Trials as Topic; Vildagliptin | 2011 |
Roux-en-Y gastric bypass-induced improvement of glucose tolerance and insulin resistance in type 2 diabetic rats are mediated by glucagon-like peptide-1.
The aim of this study was to investigate the effects of Roux-en-Y gastric bypass (RYGB) on glucose tolerance and insulin resistance in type 2 diabetic rats and the possible mechanisms involved in this process.. Thirty Goto-Kakizaki (GK) rats were randomly divided into three groups: RYGB operation, sham operation, and food restriction groups. Ten Wistar rats were used as non-diabetic control. The body weight and food consumption of rats were recorded 1 week before or every week after surgery. The fasting blood sugar and oral glucose tolerance test were performed using blood glucose meter. The levels of plasma insulin or glucagon-like peptide-1 (GLP-1) were evaluated by enzyme-linked immunosorbent assay. The insulin resistance was quantified using homeostasis model assessment method. The expression of GLP-1 receptor, Bcl-2, Bax, and caspase-3 was determined by Western blotting.. Our results revealed that RYGB efficiently improved both glucose tolerance and insulin resistance in GK diabetic rats by upregulating GLP-1/GLP-1R expression. In addition, GLP-1R agonist exendin-4 dose-dependently increased insulin secretion in RIN-m5F cells and regulated the proliferation and apoptosis of these cells.. RYGB provides a valuable therapeutic option for patients with type 2 diabetes. GLP-1 may contribute to the regulation of pancreatic β-cell function through its receptor following RYGB. Topics: Animals; Blood Glucose; Blotting, Western; Body Weight; Cell Line; Diabetes Mellitus, Type 2; Eating; Enzyme-Linked Immunosorbent Assay; Exenatide; Gastric Bypass; Glucagon-Like Peptide 1; Glucagon-Like Peptide-1 Receptor; Glucose Tolerance Test; Insulin; Insulin Resistance; Insulin-Secreting Cells; Male; Peptides; Random Allocation; Rats; Rats, Wistar; Receptors, Glucagon; Venoms | 2011 |
Acute pancreatitis associated with liraglutide.
To report what is, to our knowledge, the first postmarketing case of acute pancreatitis associated with liraglutide.. A 60-year-old female with type 2 diabetes presented with a 16-hour history of mid-epigastric pain 3 weeks after treatment was changed from exenatide 10 μg twice daily, which she had taken for 4 years, to liraglutide 1.8 mg daily. Her serum lipase level was elevated (478 units/L) at admission, and other laboratory values were within normal limits. Liraglutide was discontinued at admission. Standard therapy for pancreatitis resulted in symptom resolution and a significant decrease in serum lipase (131 units/L) by hospital day 4; she was discharged on hospital day 5.. Based on the Naranjo scale, this case represents a probable adverse drug reaction. Eight cases of pancreatitis were observed in liraglutide-treated patients in premarketing clinical trials. Extensive literature describing exenatide-related pancreatitis and premarketing reports of liraglutide-related pancreatitis, along with the temporal relationship between the initiation of liraglutide and the onset of this patient's symptoms, suggest that the episode of pancreatitis was induced by liraglutide.. Liraglutide should be used cautiously in patients with a history of pancreatitis, and clinicians should have a high index of suspicion for this rare, but potentially serious, adverse effect. Topics: Acute Disease; Clinical Trials as Topic; Diabetes Mellitus, Type 2; Exenatide; Female; Glucagon-Like Peptide 1; Humans; Hypoglycemic Agents; Lipase; Liraglutide; Middle Aged; Pancreatitis; Peptides; Venoms | 2011 |
GLP-1 analogs containing disulfide bond exhibited prolonged half-life in vivo than GLP-1.
The multiple physiological characterizations of glucagon-like peptide-1 (GLP-1) make it a promising drug candidate for the therapy of type 2 diabetes. However, the half-life of GLP-1 is short in vivo due to degradation by dipeptidyl peptidase-IV (DPP-IV) and renal clearance. This indicates that the stabilization of GLP-1 is critical for its utility in drug development. In this study, we developed a cluster of GLP-1 mutants containing an inter-disulfide bond that is predicted to increase the half-life of GLP-1 in vivo. Exendin-4 was also mutated with a disulfide bond similar to the GLP-1 analogs. In this study, the binding capacities of the mutants were determined, the stabilities of the mutants were investigated and the physiological functions of the mutants were compared with those of wild-type GLP-1 and exendin-4 in animals. The results indicated that the mutants remarkably raised the half-life in vivo; they also showed better glucose tolerance and higher HbA(1c) reduction than GLP-1 and exendin-4 in rodents. These results suggest that GLP-1 and exendin-4 mutants containing disulfide bonds might be utilized as possible potent anti-diabetic drugs in the treatment of type 2 diabetes mellitus. Topics: Amino Acid Sequence; Animals; Blood Glucose; Cells, Cultured; Diabetes Mellitus, Experimental; Diabetes Mellitus, Type 2; Dipeptidyl Peptidase 4; Disulfides; Exenatide; Glucagon; Glucagon-Like Peptide 1; Glucose Tolerance Test; Glycated Hemoglobin; Half-Life; Hypoglycemic Agents; Injections, Subcutaneous; Insulin; Male; Molecular Sequence Data; Peptides; Protein Binding; Protein Stability; Rats; Venoms | 2011 |
Bile acid sequestrants improve glycemic control in type 2 diabetes: a proposed mechanism implicating glucagon-like peptide 1 release.
Topics: Allylamine; Anticholesteremic Agents; Blood Glucose; Colesevelam Hydrochloride; Diabetes Mellitus, Type 2; Glucagon-Like Peptide 1; Humans | 2011 |
Incretin effects on β-cell function, replication, and mass: the human perspective.
Topics: Diabetes Mellitus, Type 2; Exenatide; Glucagon-Like Peptide 1; Glucagon-Like Peptide-1 Receptor; Humans; Hypoglycemic Agents; Incretins; Insulin-Secreting Cells; Liraglutide; Peptides; Receptors, Glucagon; Venoms | 2011 |
Glycemic control impact on body weight potential to reduce cardiovascular risk: glucagon-like peptide 1 agonists.
Topics: Body Weight; Cardiovascular Diseases; Diabetes Mellitus, Type 2; Glucagon-Like Peptide 1; Humans; Hypoglycemic Agents; Incretins | 2011 |
A diabetes drug, sitagliptin, also has a potential to prevent diabetes.
Topics: Animals; Diabetes Mellitus, Type 2; Disease Models, Animal; Glucagon; Glucagon-Like Peptide 1; Hypoglycemic Agents; Insulin; Insulin Secretion; Pyrazines; Rats; Sitagliptin Phosphate; Triazoles | 2011 |
Exenatide once weekly in type 2 diabetes mellitus.
Topics: Diabetes Mellitus, Type 2; Drug Administration Schedule; Exenatide; Glucagon-Like Peptide 1; Glucagon-Like Peptide-1 Receptor; Humans; Hypoglycemic Agents; Peptides; Receptors, Glucagon; Time Factors; Treatment Outcome; Venoms | 2011 |
GLP-1-derived nonapeptide GLP-1(28-36)amide inhibits weight gain and attenuates diabetes and hepatic steatosis in diet-induced obese mice.
The metabolic syndrome is an obesity-associated disease manifested as severe insulin resistance, hyperlipidemia, hepatic steatosis, and diabetes. Previously we proposed that a nonapeptide, FIAWLVKGRamide, GLP-1(28-36)amide, derived from the gluco-incretin hormone, glucagon-like peptide-1 (GLP-1), might have insulin-like actions. Recently, we reported that the nonapeptide appears to enter hepatocytes, target to mitochondria, and suppress glucose production and reactive oxygen species. Therefore, the effects of GLP-1(28-36)amide were examined in diet-induced obese, insulin-resistant mice as a model for the development of human metabolic syndrome.. Three- to 11-week infusions of GLP-1(28-36)amide were administered via osmopumps to mice fed a very high fat diet (VHFD) and to control mice on a normal low fat diet (LFD). Body weight, DXA, energy intake, plasma insulin and glucose, and liver triglyceride levels were assessed. GLP-1(28-36)amide inhibited weight gain, accumulation of liver triglycerides, and improved insulin sensitivity by attenuating the development of fasting hyperglycemia and hyperinsulinemia in mice fed VHFD. GLP-1(28-36)amide had no observable effects in control LFD mice. Surprisingly, the energy intake of peptide-infused obese mice is 25-70% greater than in obese mice receiving vehicle alone, yet did not gain excess weight.. GLP-1(28-36)amide exerts insulin-like actions selectively in conditions of obesity and insulin resistance. The peptide curtails weight gain in diet-induced obese mice in the face of an increase in energy intake suggesting increased energy expenditure. These findings suggest utility of GLP-1(28-36)amide, or a peptide mimetic derived there from, for the treatment of insulin resistance and the metabolic syndrome. Topics: Animals; Diabetes Mellitus, Type 2; Dietary Fats; Eating; Fatty Liver; Glucagon-Like Peptide 1; Hyperglycemia; Hyperinsulinism; Insulin Resistance; Liver; Male; Metabolic Syndrome; Mice; Mice, Inbred C57BL; Obesity; Peptide Fragments; Triglycerides; Weight Gain | 2011 |
Comparison of glucostatic parameters after hypocaloric diet or bariatric surgery and equivalent weight loss.
Weight-loss independent mechanisms may play an important role in the improvement of glucose homeostasis after Roux-en-Y gastric bypass (RYGB). The objective of this analysis was to determine whether RYGB causes greater improvement in glucostatic parameters as compared with laparoscopic adjustable gastric banding (LAGB) or low calorie diet (LCD) after equivalent weight loss and independent of enteral nutrient passage. Study 1 recruited participants without type 2 diabetes mellitus (T2DM) who underwent LAGB (n = 8) or RYGB (n = 9). Study 2 recruited subjects with T2DM who underwent LCD (n = 7) or RYGB (n = 7). Insulin-supplemented frequently-sampled intravenous glucose tolerance test (fsIVGTT) was performed before and after equivalent weight reduction. MINMOD analysis of insulin sensitivity (Si), acute insulin response to glucose (AIRg) and C-peptide (ACPRg) response to glucose, and insulin secretion normalized to the degree of insulin resistance (disposition index (DI)) were analyzed. Weight loss was comparable in all groups (7.8 ± 0.4%). In Study 1, significant improvement of Si, ACPRg, and DI were observed only after LAGB. In Study 2, Si, ACPRg, and plasma adiponectin increased significantly in the RYGB-DM group but not in LCD. DI improved in both T2DM groups, but the absolute increase was greater after RYGB (258.2 ± 86.6 vs. 55.9 ± 19.9; P < 0.05). Antidiabetic medications were discontinued after RYGB contrasting with 55% reduction in the number of medications after LCD. No intervention affected fasting glucagon-like peptide (GLP)-1, peptide YY (PYY) or ghrelin levels. In conclusion, RYGB produced greater improvement in Si and DI compared with diet at equivalent weight loss in T2DM subjects. Such a beneficial effect was not observed in nondiabetic subjects at this early time-point. Topics: Adiponectin; Adult; Blood Glucose; C-Peptide; Caloric Restriction; Diabetes Mellitus, Type 2; Diet, Reducing; Female; Gastric Bypass; Ghrelin; Glucagon-Like Peptide 1; Glucose Tolerance Test; Humans; Insulin; Insulin Resistance; Insulin Secretion; Laparoscopy; Male; Middle Aged; Obesity; Peptide YY; Weight Loss | 2011 |
Disulfide bond prolongs the half-life of therapeutic peptide-GLP-1.
The multiple physiological characterization of glucagon-like peptide-1 (GLP-1) makes it a promising drug candidate for the therapy of type 2 diabetes. However, the half-life of GLP-1 is short in vivo due to rapid degradation by dipeptidyl peptidase-IV (DPP-IV) and renal clearance. This indicates that the stabilization of GLP-1 is critical for its utility in drug development. In this study, we developed a cluster of GLP-1 homodimeric analogs, which fused the mutated GLP-1 monomer by an intra-disulfide bridge. The stabilities of the GLP-1 homodimeric analogs were investigated and the physiological functions of the analogs were compared with those of wild-type GLP-1 in rats and human serum. Single dose glucose tolerance test was performed to investigate the administration frequency which satisfied the efficient glucose regulatory in rats. Multiple dose glucose tolerance tests were employed also to study the long-acting anti-diabetic activity of GLP-1 homodimeric analog. The results indicated that the GLP-1 homodimeric analog (hdGLP1G10C) remarkably raised the biological half-life of GLP-1; also HDGLP1G10C showed better glucose tolerance and higher HbA(1c) reduction than GLP-1 in rodents. Based upon the results in this study, it was suggested that hdGLP1G10C prolonged the stability of GLP-1 and retained the biological activity of GLP-1. The improved physiological characterization of hdGLP1G10C makes it as possible potent anti-diabetic drug in the treatment of type 2 diabetes mellitus. Topics: Animals; Blood Glucose; Diabetes Mellitus, Type 2; Dimerization; Dipeptidyl Peptidase 4; Disulfides; Drug Design; Drug Stability; Glucagon-Like Peptide 1; Glucose Tolerance Test; Glycated Hemoglobin; Half-Life; Humans; Hypoglycemic Agents; Insulin; Male; Mutation; Rats; Rats, Sprague-Dawley; Rats, Zucker; Serum; Spectrometry, Mass, Matrix-Assisted Laser Desorption-Ionization | 2011 |
First-phase insulin secretion, insulin sensitivity, ghrelin, GLP-1, and PYY changes 72 h after sleeve gastrectomy in obese diabetic patients: the gastric hypothesis.
The aim of this study was to evaluate the possible role of sleeve gastrectomy (SG) per se in the reversibility of diabetes.. Insulin secretion and peripheral insulin sensitivity using the intravenous glucose tolerance test (IVGTT) were assessed in 18 obese type 2 diabetic patients and in 10 nondiabetic obese patients before and 3 days after SG, before any food intake and any weight change occurrence. At the same time, ghrelin, GLP-1, and PYY levels were determined.. In diabetic patients who had the disease less than 10.5 years, the first phase of insulin secretion promptly improved after SG. The early insulin area under the curve (AUC) significantly increased at the postoperative IVGTT, indicating an increased glucose-induced insulin secretion. The second phase of insulin secretion (late AUC) significantly decreased after SG in all groups, indicating an improved insulin peripheral sensitivity. In all groups, pre- and postoperatively, intravenous glucose stimulation determined a decrease in ghrelin values and an increase in GLP-1 and PYY values. However, in the group of patients with disease duration >10.5 years, the differences were not significant except for the late insulin AUC. Postoperative basal and intravenous glucose-stimulated ghrelin levels were lower than preoperative levels in all groups of patients. Basal and intravenous stimulated GLP-1 and PYY postoperative values were higher than preoperative levels in all groups.. Restoration of the first phase of insulin secretion and improved insulin sensitivity in diabetic obese patients immediately after SG, before any food passage through the gastrointestinal tract and before any weight loss, seem to be related to ghrelin, GLP-1, and PYY hormonal changes of possible gastric origin and was neither meal- nor weight-change-related. Duration of the disease up to 10.5 years seems to be a major cut off in the pathophysiological changes induced by SG. A "gastric" hypothesis may be put forward to explain the antidiabetes effect of SG. Topics: Diabetes Mellitus, Type 2; Female; Gastrectomy; Ghrelin; Glucagon-Like Peptide 1; Glucose Tolerance Test; Humans; Insulin; Insulin Resistance; Male; Middle Aged; Obesity, Morbid; Peptide YY | 2011 |
Dietary-resistant starch improves maternal glycemic control in Goto-Kakizaki rat.
Dietary prebiotics show potential in anti-diabetes. Dietary resistant starch (RS) has a favorable impact on gut hormone profiles, including glucagon-like peptide-1 (GLP-1) consistently released, a potent anti-diabetic incretin. Also RS reduced body fat and improved glucose tolerance in rats and mice. In the current project, we hypothesize that dietary-resistant starch can improve insulin sensitivity and pancreatic β cell mass in a type 2 diabetic rat model. Altered gut fermentation and microbiota are the initial mechanisms, and enhancement in serum GLP-1 is the secondary mechanism.. In this study, GK rats were fed an RS diet with 30% RS and an energy control diet. After 10 wk, these rats were mated and went through pregnancy and lactation. At the end of the study, pancreatic β cell mass, insulin sensitivity, pancreatic insulin content, total GLP-1 levels, cecal short-chain fatty acid concentrations and butyrate producing bacteria in cecal contents were greatly improved by RS feeding. The offspring of RS-fed dams showed improved fasting glucose levels and normal growth curves.. Dietary RS is potentially of great therapeutic importance in the treatment of diabetes and improvement in outcomes of pregnancy complicated by diabetes. Topics: Animals; Animals, Newborn; Blood Glucose; Body Weight; Butyrates; Cecum; Diabetes Mellitus, Type 2; Disease Models, Animal; Eating; Fatty Acids, Volatile; Female; Glucagon-Like Peptide 1; Hydrogen-Ion Concentration; Hyperglycemia; Insulin Resistance; Insulin-Secreting Cells; Intestinal Mucosa; Ion Channels; Mitochondrial Proteins; Pregnancy; Pregnancy in Diabetics; Rats; Starch; Uncoupling Protein 1 | 2011 |
Peptide complex containing GLP-1 exhibited long-acting properties in the treatment of type 2 diabetes.
The multiple physiological characterizations of glucagon-like peptide-1 (GLP-1) make it a promising drug candidate for the treatment of type 2 diabetes. However, in vivo, the half-life of GLP-1 is short, which is caused by the degradation of dipeptidyl peptidase-IV (DPP-IV) and renal clearance. Thus, the stabilization of GLP-1 is critical for its utility in drug development. Peptides known as GLP-1 protectors are predicted to increase the half-life of GLP-1 in vivo. Protecting peptides are able to form stable complexes by non-covalent interactions with human GLP-1. In this study, the stability of the complex was investigated, and the physiological functions of the GLP-1/peptide 1 complex were compared to those of exenatide and liraglutide in animals. The results indicated that the GLP-1/peptide 1 complex remarkably raised the half-life of GLP-1 in vivo and showed better glucose tolerance and higher HbA(1c) reduction than exenatide and liraglutide in rodents. Based upon these results, it is suggested that the GLP-1/peptide 1 complex might be utilized as a possible potent anti-diabetic drug in the treatment of type 2 diabetes mellitus. Topics: Animals; Chromatography, High Pressure Liquid; Diabetes Mellitus, Type 2; Exenatide; Glucagon-Like Peptide 1; Humans; Hypoglycemic Agents; Liraglutide; Male; Peptides; Rats; Spectrometry, Mass, Electrospray Ionization; Venoms | 2011 |
Resolution of diabetes mellitus by ileal transposition compared with biliopancreatic diversion in a nonobese animal model of type 2 diabetes.
It has been demonstrated that biliopancreatic diversion (BPD) and ileal transposition (IT) effectively induce weight loss and long-term control of type 2 diabetes in morbidly obese individuals. It is unknown whether the control of diabetes is better after IT or after BPD. The objective of this study was to investigate the effects of IT and BPD on the control of diabetes in an animal model.. We performed IT and BPD on 10- to 12-week-old Goto-Kakizaki rats with a spontaneous nonobese model of type 2 diabetes, and we performed a series of detection. The rats were observed for 24 weeks after surgery.. Animals who underwent IT and BPD demonstrated improved glucose tolerance, insulin sensitivity and the secretion of glucagon-like peptide-1 compared with the sham-operated animals. Furthermore, IT resulted in a shorter duration of surgery and better postoperative recovery than BPD.. This study provides strong evidence for the crucial role of the hindgut in the resolution of diabetes after duodenum-jejunum bypass or IT. We confirmed that IT was associated with better postoperative recovery than BPD and had a similar control of diabetes as BPD in nonobese animals with type 2 diabetes. Topics: Anastomosis, Surgical; Animals; Biliopancreatic Diversion; Blood Glucose; Diabetes Mellitus, Experimental; Diabetes Mellitus, Type 2; Glucagon-Like Peptide 1; Ileum; Insulin Resistance; Male; Rats | 2011 |
A novel GLP-1 analog exhibits potent utility in the treatment of type 2 diabetes with an extended half-life and efficient glucose clearance in vivo.
The multiple physiological characterizations of glucagon-like peptide-1 (GLP-1) make it a promising drug candidate for the therapy of type 2 diabetes. However, the half-life of GLP-1 is short in vivo due to degradation by dipeptidyl peptidase-IV (DPP-IV) and renal clearance. Therefore, the stabilization of GLP-1 is critical for its utility in drug development. Based on our previous research, a GLP-1 analog that contained an intra-disulfide bond exhibited a prolonged biological half-life. In this study, we improved upon previous analogs with a novel GLP-1 analog that contained a tryptophan cage-like sequence for an improved binding affinity to the GLP-1 receptor. The binding capacities and the stabilities of GLP715a were investigated, and the physiological functions of the GLP715a were compared to those of the wild-type GLP-1 in animals. The results demonstrated that the new GLP-1 analog (GLP715a) increased its biological half-life to approximately 48h in vivo; GLP715a also exhibited a higher binding affinity to the GLP-1 receptor than the wild-type GLP-1. The increased binding capacity of GLP715a to its receptor resulted in a quick response to glucose administration. The long-acting anti-diabetic property of GLP715a was revealed by its increased glucose tolerance, higher HbA(1c) reduction, more efficient glucose clearance and quicker insulin stimulation upon glucose administration compared to the wild-type GLP-1 in rodents. The improved physiological characterizations of GLP715a make it a possible potent anti-diabetic drug in the treatment of type 2 diabetes mellitus. Topics: Amino Acid Sequence; Animals; Blood Glucose; Diabetes Mellitus, Type 2; Dipeptidyl Peptidase 4; Drug Design; Drug Stability; Glucagon-Like Peptide 1; Glucagon-Like Peptide-1 Receptor; Glucose Tolerance Test; Glycated Hemoglobin; Half-Life; Humans; Hypoglycemic Agents; Insulin; Kinetics; Male; Molecular Sequence Data; Protein Binding; Rats; Rats, Sprague-Dawley; Rats, Zucker; Receptors, Glucagon; Serum; Spectrometry, Mass, Matrix-Assisted Laser Desorption-Ionization; Tryptophan | 2011 |
Characterization of human myotubes from type 2 diabetic and nondiabetic subjects using complementary quantitative mass spectrometric methods.
Skeletal muscle is a key tissue site of insulin resistance in type 2 diabetes. Human myotubes are primary skeletal muscle cells displaying both morphological and biochemical characteristics of mature skeletal muscle and the diabetic phenotype is conserved in myotubes derived from subjects with type 2 diabetes. Several abnormalities have been identified in skeletal muscle from type 2 diabetic subjects, however, the exact molecular mechanisms leading to the diabetic phenotype has still not been found. Here we present a large-scale study in which we combine a quantitative proteomic discovery strategy using isobaric peptide tags for relative and absolute quantification (iTRAQ) and a label-free study with a targeted quantitative proteomic approach using selected reaction monitoring to identify, quantify, and validate changes in protein abundance among human myotubes obtained from nondiabetic lean, nondiabetic obese, and type 2 diabetic subjects, respectively. Using an optimized protein precipitation protocol, a total of 2832 unique proteins were identified and quantified using the iTRAQ strategy. Despite a clear diabetic phenotype in diabetic myotubes, the majority of the proteins identified in this study did not exhibit significant abundance changes across the patient groups. Proteins from all major pathways known to be important in type 2 diabetic subjects were well-characterized in this study. This included pathways like the trichloroacetic acid (TCA) cycle, lipid oxidation, oxidative phosphorylation, the glycolytic pathway, and glycogen metabolism from which all but two enzymes were found in the present study. None of these enzymes were found to be regulated at the level of protein expression or degradation supporting the hypothesis that these pathways are regulated at the level of post-translational modification. Twelve proteins were, however, differentially expressed among the three different groups. Thirty-six proteins were chosen for further analysis and validation using selected reaction monitoring based on the regulation identified in the iTRAQ discovery study. The abundance of adenosine deaminase was considerably down-regulated in diabetic myotubes and as the protein binds propyl dipeptidase (DPP-IV), we speculate whether the reduced binding of adenosine deaminase to DPP-IV may contribute to the diabetic phenotype in vivo by leading to a higher level of free DPP-IV to bind and inactivate the anti-diabetic hormones, glucagon-like peptide-1 and glucos Topics: Adenosine Deaminase; Body Mass Index; Case-Control Studies; Cells, Cultured; Diabetes Mellitus, Type 2; Dipeptidyl Peptidase 4; Down-Regulation; Energy Metabolism; Gastric Inhibitory Polypeptide; Gene Expression; Gene Expression Profiling; Glucagon-Like Peptide 1; Humans; Insulin; Insulin Resistance; Middle Aged; Muscle Fibers, Skeletal; Obesity; Protein Binding; Proteomics; Thinness | 2011 |
A synthetic optogenetic transcription device enhances blood-glucose homeostasis in mice.
Synthetic biology has advanced the design of genetic devices that can be used to reprogram metabolic activities in mammalian cells. By functionally linking the signal transduction of melanopsin to the control circuit of the nuclear factor of activated T cells, we have designed a synthetic signaling cascade enabling light-inducible transgene expression in different cell lines grown in culture or bioreactors or implanted into mice. In animals harboring intraperitoneal hollow-fiber or subcutaneous implants containing light-inducible transgenic cells, the serum levels of the human glycoprotein secreted alkaline phosphatase could be remote-controlled with fiber optics or transdermally regulated through direct illumination. Light-controlled expression of the glucagon-like peptide 1 was able to attenuate glycemic excursions in type II diabetic mice. Synthetic light-pulse-transcription converters may have applications in therapeutics and protein expression technology. Topics: Alkaline Phosphatase; Animals; Bioreactors; Blood Glucose; Cell Line; Cell Line, Tumor; Diabetes Mellitus, Type 2; Gene Expression Regulation; Genes, Reporter; Genetic Engineering; Glucagon-Like Peptide 1; GPI-Linked Proteins; Homeostasis; Humans; Insulin; Isoenzymes; Light; Light Signal Transduction; Mice; NFATC Transcription Factors; Optical Fibers; Rod Opsins; Signal Transduction; Synthetic Biology; Transcription, Genetic; Transfection; Transgenes | 2011 |
The changes of pro-opiomelanocortin neurons in type 2 diabetes mellitus rats after ileal transposition: the role of POMC neurons.
Ileal transposition (IT) can effectively resolve obesity and improve type 2 diabetes. IT is associated with increased glucagon-like peptide 1 secretion. The mechanisms mediating the effects of IT on obesity and diabetes remain undefined. Given the role of pro-opiomelanocortin neurons in energy balance, we sought to determine its potential role in these processes.. Twenty non-obese diabetic Goto-Kakizaki rats underwent either IT or sham operation. Various measures including food intake, body weight, fasting plasma glucose, glucagon-like peptide 1 level, activated pro-opiomelanocortin neuron number, and pro-opiomelanocortin mRNA expression were evaluated.. The IT group demonstrated significantly improved plasma glucose homeostasis with increased glucagon-like peptide 1 secretion. The IT group ate less and demonstrated reduced body weight gain over time. These effects were also associated with increased central neuronal activity with increased pro-opiomelanocortin and derivative gene expression in the hypothalamus and increased protein expression in the pituitary gland.. More pro-opiomelanocortin neurons in the hypothalamus of diabetes rats were activated after ileal transposition. These data suggest a potential important role for pro-opiomelanocortin neurons in the resolution of diabetes after IT. Topics: Animals; Arcuate Nucleus of Hypothalamus; Blood Glucose; Diabetes Mellitus, Type 2; Gene Expression; Glucagon-Like Peptide 1; Ileum; Immunohistochemistry; Male; Neurons; Pituitary Gland; Pro-Opiomelanocortin; Rats; RNA, Messenger; Up-Regulation | 2011 |
Tigerinin-1R: a potent, non-toxic insulin-releasing peptide isolated from the skin of the Asian frog, Hoplobatrachus rugulosus.
Characterization of peptides in the skin of the Vietnamese common lowland frog Hoplobatrachus rugulosus with the ability to stimulate insulin release in vitro and improve glucose tolerance in vivo.. Peptides in an extract of skin were purified by reversed-phase HPLC, and their abilities to stimulate the release of insulin and the cytosolic enzyme lactate dehydrogenase were determined using BRIN-BD11 clonal β cells. Insulin-releasing potencies of synthetic peptides and their effects on membrane potential and intracellular Ca²⁺ concentration were also measured using BRIN-BD11 cells. Effects on glucose tolerance and insulin release in vivo were determined in mice fed a high-fat diet to induce obesity and insulin resistance.. A cyclic dodecapeptide (RVCSAIPLPICH.NH₂), termed tigerinin-1R, was isolated from the skin extract that lacked short-term cytotoxic and haemolytic activity but significantly (p < 0.01) stimulated the rate of release of insulin from BRIN-BD11 cells at concentrations ≥ 0.1 nM. The maximum response was 405% of the basal rate at 5.6 mM ambient glucose concentration and 290% of basal rate at 16.7 mM glucose. C-terminal α-amidation was necessary for high potency and a possible mechanism of action of the peptide-involved membrane depolarization and an increase in intracellular Ca²⁺ concentration. Administration of tigerinin-1R (75 nmol/kg body weight) to high fat-fed mice significantly (p < 0.05) enhanced insulin release and improved glucose tolerance during the 60-min period following an intraperitoneal glucose load.. Tigerinin-1R is a potent, non-toxic insulin-releasing peptide that shows potential for development into an agent for the treatment of type 2 diabetes. Topics: Amino Acid Sequence; Amphibian Proteins; Animals; Antimicrobial Cationic Peptides; Chromatography, High Pressure Liquid; Diabetes Mellitus, Type 2; Diet, High-Fat; Glucagon-Like Peptide 1; Glucose; Insulin; Insulin Secretion; Mice; Peptides; Ranidae; Skin | 2011 |
Glucagon-like peptide-1 (GLP-1) and the regulation of human invariant natural killer T cells: lessons from obesity, diabetes and psoriasis.
The innate immune cells, invariant natural killer T cells (iNKT cells), are implicated in the pathogenesis of psoriasis, an inflammatory condition associated with obesity and other metabolic diseases, such as diabetes and dyslipidaemia. We observed an improvement in psoriasis severity in a patient within days of starting treatment with an incretin-mimetic, glucagon-like peptide-1 (GLP-1) receptor agonist. This was independent of change in glycaemic control. We proposed that this unexpected clinical outcome resulted from a direct effect of GLP-1 on iNKT cells.. We measured circulating and psoriatic plaque iNKT cell numbers in two patients with type 2 diabetes and psoriasis before and after commencing GLP-1 analogue therapy. In addition, we investigated the in vitro effects of GLP-1 on iNKT cells and looked for a functional GLP-1 receptor on these cells.. The Psoriasis Area and Severity Index improved in both patients following 6 weeks of GLP-1 analogue therapy. This was associated with an alteration in iNKT cell number, with an increased number in the circulation and a decreased number in psoriatic plaques. The GLP-1 receptor was expressed on iNKT cells, and GLP-1 induced a dose-dependent inhibition of iNKT cell cytokine secretion, but not cytolytic degranulation in vitro.. The clinical effect observed and the direct interaction between GLP-1 and the immune system raise the possibility of therapeutic applications for GLP-1 in inflammatory conditions such as psoriasis. Topics: Cell Count; Cell Line; Cytokines; Diabetes Mellitus, Type 2; Female; Gene Expression Regulation; Glucagon-Like Peptide 1; Glucagon-Like Peptide-1 Receptor; Humans; Hypoglycemic Agents; Immunologic Factors; Liraglutide; Male; Middle Aged; Molecular Targeted Therapy; Natural Killer T-Cells; Obesity; Psoriasis; Receptors, Glucagon; RNA, Messenger; Severity of Illness Index; Signal Transduction; Skin | 2011 |
cAMP-secretion coupling is impaired in diabetic GK/Par rat β-cells: a defect counteracted by GLP-1.
cAMP-raising agents with glucagon-like peptide-1 (GLP-1) as the first in class, exhibit multiple actions that are beneficial for the treatment of type 2 diabetic (T2D) patients, including improvement of glucose-induced insulin secretion (GIIS). To gain additional insight into the role of cAMP in the disturbed stimulus-secretion coupling within the diabetic β-cell, we examined more thoroughly the relationship between changes in islet cAMP concentration and insulin release in the GK/Par rat model of T2D. Basal cAMP content in GK/Par islets was significantly higher, whereas their basal insulin release was not significantly different from that of Wistar (W) islets. Even in the presence of IBMX or GLP-1, their insulin release did not significantly change despite further enhanced cAMP accumulation in both cases. The high basal cAMP level most likely reflects an increased cAMP generation in GK/Par compared with W islets since 1) forskolin dose-dependently induced an exaggerated cAMP accumulation; 2) adenylyl cyclase (AC)2, AC3, and G(s)α proteins were overexpressed; 3) IBMX-activated cAMP accumulation was less efficient and PDE-3B and PDE-1C mRNA were decreased. Moreover, the GK/Par insulin release apparatus appears less sensitive to cAMP, since GK/Par islets released less insulin at submaximal cAMP levels and required five times more cAMP to reach a maximal secretion rate no longer different from W. GLP-1 was able to reactivate GK/Par insulin secretion so that GIIS became indistinguishable from that of W. The exaggerated cAMP production is instrumental, since GLP-1-induced GIIS reactivation was lost in the presence the AC blocker 2',5'-dideoxyadenosine. This GLP-1 effect takes place in the absence of any improvement of the [Ca(2+)](i) response and correlates with activation of the cAMP-dependent PKA-dependent pathway. Topics: Animals; Cells, Cultured; Cyclic AMP; Diabetes Mellitus, Experimental; Diabetes Mellitus, Type 2; Disease Models, Animal; Glucagon-Like Peptide 1; Glucose; Insulin; Insulin Secretion; Insulin-Secreting Cells; Male; Rats; Rats, Wistar; Secretory Pathway; Streptozocin | 2011 |
Diabetes as a risk factor for Alzheimer's disease: insulin signalling impairment in the brain as an alternative model of Alzheimer's disease.
Surprisingly little is known about the mechanisms that trigger the onset of AD (Alzheimer's disease) in sporadic forms. A number of risk factors have been identified that may shed light on the mechanisms that may trigger or facilitate the development of AD. Recently, T2DM (Type 2 diabetes mellitus) has been identified as a risk factor for AD. A common observation for both conditions is the desensitization of insulin receptors in the brain. Insulin acts as a growth factor in the brain and is neuroprotective, activates dendritic sprouting, regeneration and stem cell proliferation. The impairment of this important growth factor signal may facilitate the development of AD. Insulin as well as other growth factors have shown neuroprotective properties in preclinical and clinical trials. Several drugs have been developed to treat T2DM, which re-sensitize insulin receptors and may be of use to prevent neurodegenerative processes in the brain. In particular, the incretins GLP-1 (glucagon-like peptide-1) and GIP (glucose-dependent insolinotropic polypeptide) are hormones that re-sensitize insulin signalling. Incretins also have similar growth-factor-like properties as insulin and are neuroprotective. In mouse models of AD, GLP-1 receptor agonists reduce amyloid plaque formation, reduce the inflammation response in the brain, protect neurons from oxidative stress, induce neurite outgrowth, and protect synaptic plasticity and memory formation from the detrimental effects caused by β-amyloid production and inflammation. Other growth factors such as BDNF (brain-derived neurotrophic factor), NGF (nerve growth factor) or IGF-1 (insulin-like growth factor 1) also have shown a range of neuroprotective properties in preclinical studies. These results show that these growth factors activate similar cell signalling mechanisms that are protective and regenerative, and suggest that the initial process that may trigger the cascade of neurodegenerative events in AD could be the impairment of growth factor signalling such as early insulin receptor desensitization. Topics: Alzheimer Disease; Animals; Diabetes Mellitus, Type 2; Disease Models, Animal; Gastric Inhibitory Polypeptide; Glucagon-Like Peptide 1; Glucagon-Like Peptide-1 Receptor; Humans; Insulin; Intercellular Signaling Peptides and Proteins; Mice; Mice, Transgenic; Neuroprotective Agents; Receptors, Glucagon; Signal Transduction | 2011 |
Pleiotropic effects of GIP on islet function involve osteopontin.
The incretin hormone GIP (glucose-dependent insulinotropic polypeptide) promotes pancreatic β-cell function by potentiating insulin secretion and β-cell proliferation. Recently, a combined analysis of several genome-wide association studies (Meta-analysis of Glucose and Insulin-Related Traits Consortium [MAGIC]) showed association to postprandial insulin at the GIP receptor (GIPR) locus. Here we explored mechanisms that could explain the protective effects of GIP on islet function.. Associations of GIPR rs10423928 with metabolic and anthropometric phenotypes in both nondiabetic (N = 53,730) and type 2 diabetic individuals (N = 2,731) were explored by combining data from 11 studies. Insulin secretion was measured both in vivo in nondiabetic subjects and in vitro in islets from cadaver donors. Insulin secretion was also measured in response to exogenous GIP. The in vitro measurements included protein and gene expression as well as measurements of β-cell viability and proliferation.. The A allele of GIPR rs10423928 was associated with impaired glucose- and GIP-stimulated insulin secretion and a decrease in BMI, lean body mass, and waist circumference. The decrease in BMI almost completely neutralized the effect of impaired insulin secretion on risk of type 2 diabetes. Expression of GIPR mRNA was decreased in human islets from carriers of the A allele or patients with type 2 diabetes. GIP stimulated osteopontin (OPN) mRNA and protein expression. OPN expression was lower in carriers of the A allele. Both GIP and OPN prevented cytokine-induced reduction in cell viability (apoptosis). In addition, OPN stimulated cell proliferation in insulin-secreting cells.. These findings support β-cell proliferative and antiapoptotic roles for GIP in addition to its action as an incretin hormone. Identification of a link between GIP and OPN may shed new light on the role of GIP in preservation of functional β-cell mass in humans. Topics: Alleles; Diabetes Mellitus, Type 2; Gastric Inhibitory Polypeptide; Genome-Wide Association Study; Glucagon-Like Peptide 1; Humans; Insulin; Insulin Secretion; Insulin-Secreting Cells; Islets of Langerhans; Male; Osteopontin | 2011 |
Homozygous carriers of the G allele of rs4664447 of the glucagon gene (GCG) are characterised by decreased fasting and stimulated levels of insulin, glucagon and glucagon-like peptide (GLP)-1.
The glucagon gene (GCG) encodes several hormones important for energy metabolism: glucagon, oxyntomodulin and glucagon-like peptide (GLP)-1 and -2. Variants in GCG may associate with type 2 diabetes, obesity and/or related metabolic traits.. GCG was re-sequenced as a candidate gene in 865 European individuals. Twenty-nine variants were identified. Four variants that were considered to have a likelihood for altered functionality: rs4664447, rs7581952, Ile158Val and Trp169Ter, were genotyped in 17,584 Danes.. When examined in 5,760 treatment-naive individuals, homozygous carriers of the low frequency (minor allele frequency 2.3%) G allele of rs4664447, predicted to disrupt an essential splice enhancer binding site, had lower levels of fasting plasma glucose (mean ± SD, 4.8 ± 1.2 vs 5.5 ± 0.8 mmol/l, p = 0.004); fasting serum insulin (22 ± 14 vs 42 ± 27 pmol/l, p = 0.04); glucose-stimulated serum insulin (159 ± 83 vs 290 ± 183 pmol/l, p = 0.01) and adult height (165 ± 10 vs 172 ± 9 cm, p = 0.0009) compared with A allele carriers. During oral glucose tolerance and hyperglycaemic arginine stimulation tests, the plasma AUC for GLP-1 (730 ± 69 vs 1,334 ± 288 pmol/l × min, p = 0.0002) and basal and stimulated levels of serum insulin and plasma glucagon were ∼50% decreased (p < 0.001) among three homozygous carriers compared with nine matched wild-type carriers. rs7581952, Ile158Val and Trp169Ter (where 'Ter' indicates 'termination') variants of GCG did not significantly associate or co-segregate with the metabolic traits examined.. Re-sequencing of GCG revealed a low frequency intronic variant, rs4664447, and follow-up physiological studies suggest that this variant in homozygous form may cause decreased fasting and stimulated levels of insulin, glucagon and GLP-1. Overall, our findings suggest that variation in GCG has no major impact on carbohydrate metabolism in the study populations examined. Topics: Adolescent; Adult; Age of Onset; Aged; Case-Control Studies; Child; Child, Preschool; Czechoslovakia; Denmark; Diabetes Mellitus, Type 2; Europe; Female; Genetic Association Studies; Glucagon; Glucagon-Like Peptide 1; Homozygote; Humans; Infant; Insulin; Insulin Resistance; Insulin Secretion; Male; Middle Aged; Obesity; Polymorphism, Single Nucleotide | 2011 |
Combination of TS-021 with metformin improves hyperglycemia and synergistically increases pancreatic β-cell mass in a mouse model of type 2 diabetes.
The objectives of this study were to elucidate the effects of a potent dipeptidyl peptidase (DPP)-IV inhibitor, TS-021, combined with/without metformin on glycemic control and pathological changes in pancreatic islets in high-fat diet and streptozotocin-induced (HFD-STZ) diabetic mice.. The anti-diabetic effects of TS-021 and/or metformin in HFD-STZ mice were examined in both acute and chronic treatment studies. In addition, we performed immunohistochemical analysis after repeated administration of TS-021 and/or metformin to HFD-STZ mice twice a day for 5 weeks.. In the acute treatment study, TS-021 and/or metformin significantly improved glucose tolerance and glucagon-like peptide-1 (GLP-1) level, and TS-021 alone or in combination with metformin significantly increased the plasma insulin level after nutrient ingestion. In the chronic treatment study, TS-021 in combination with metformin significantly lowered the glycosylated hemoglobin level, plasma insulin level, and α-cell-to-β-cell area ratio in pancreatic islets. In particular, the combined treatment synergistically increased the insulin-positive area in pancreatic islets from 32.3% in diabetic mice treated with the vehicle to 51.1% (TS-021 alone, 35.3%; metformin alone, 30.6%).. The present study demonstrated that the coadministration of TS-021 and metformin synergistically improved the islet morphology by increasing the circulating level of biologically active GLP-1, which is thought to result from two different mechanisms (namely, an increase in GLP-1 secretion and DPP-IV inhibition). These findings strongly support the rationale for combined treatment with DPP-IV inhibitors plus metformin in clinical practice by clearly demonstrating an anti-diabetic effect associated with the remarkable improvement in pancreatic β-cell morphology. Topics: Animals; Benzenesulfonates; Diabetes Mellitus, Type 2; Dipeptidyl Peptidase 4; Drug Synergism; Glucagon-Like Peptide 1; Glycated Hemoglobin; Hyperglycemia; Hypoglycemic Agents; Insulin; Insulin-Secreting Cells; Male; Metformin; Mice; Mice, Inbred C57BL; Pyrrolidines | 2011 |
Metabolic effects of an entero-omentectomy in mildly obese type 2 diabetes mellitus patients after three years.
Various digestive tract procedures effectively improve metabolic syndrome, especially the control of type 2 diabetes mellitus. Very good metabolic results have been shown with vertical gastrectomy and entero-omentectomy; however, the metabolic effects of an isolated entero-omentectomy have not been previously studied.. Nine patients with type 2 diabetes mellitus and a body mass index ranging from 29 to 34.8 kg/m² underwent an entero-omentectomy procedure that consisted of an enterectomy of the middle jejunum and exeresis of the major part of the omentum performed through a mini-laparotomy. Glucagon-like peptide-1 and peptide YY were measured preoperatively and three months following the operation. Fasting and postprandial variations in glycemia, insulinemia, triglyceridemia, hemoglobin A1c, and body mass index were determined in the preoperative period and 3, 18 and, 36 months after the operation.. All patients significantly improved the control of their type 2 diabetes mellitus. Postprandial secretion of peptide YY and Glucagon-like peptide-1 were enhanced, whereas hemoglobin A1c, fasting and postprandial glucose, insulin, and triglyceride levels were significantly reduced. Mean body mass index was reduced from 31.1 to 27.3 kg/m². No major surgical or nutritional complications occurred.. Entero-omentectomy is easy and safe to perform. A simple reduction in jejunal extension and visceral fat causes important improvements in the metabolic profile. Topics: Adult; Body Mass Index; Diabetes Mellitus, Type 2; Female; Glucagon-Like Peptide 1; Humans; Jejunum; Male; Metabolic Syndrome; Middle Aged; Nutritional Status; Omentum; Peptide YY; Postoperative Period; Time Factors; Treatment Outcome | 2011 |
Place in therapy for liraglutide and saxagliptin for type 2 diabetes and FDA liraglutide warning.
Topics: Adamantane; Diabetes Mellitus, Type 2; Dipeptides; Dipeptidyl-Peptidase IV Inhibitors; Glucagon-Like Peptide 1; Humans; Incretins | 2011 |
Glucagon-like peptide-1 (GLP-1) receptor agonists, obesity and psoriasis: diabetes meets dermatology.
Type 2 diabetes mellitus is characterised by beta cell failure, which frequently develops in the setting of insulin resistance. Inflammation contributes to the pathophysiology of type 2 diabetes by impairing insulin action in peripheral tissues and via reduction of beta cell function. Inflammation may also play an important role in the development of complications that arise in patients with type 2 diabetes. Hence, the anti-inflammatory actions of commonly used glucose-lowering drugs may contribute, indirectly, to their mechanisms of action and therapeutic benefit. Herein we highlight the anti-inflammatory actions of glucagon-like peptide-1 (GLP-1), which exerts direct and indirect actions on immune function. The observations that GLP-1 receptor agonists exert anti-inflammatory actions in preclinical studies, taken together with case reports linking improvements in psoriasis with GLP-1 receptor agonist therapy, illustrates the emerging clinical implications of non-classical anti-inflammatory actions of incretin-based therapeutics. Topics: Diabetes Mellitus, Type 2; Female; Glucagon-Like Peptide 1; Glucagon-Like Peptide-1 Receptor; Humans; Male; Natural Killer T-Cells; Psoriasis; Receptors, Glucagon | 2011 |
GLP-1 agonist treatment: implications for diabetic retinopathy screening.
Rapid improvement in glycaemic control induced by GLP-1 agonist therapy could be yet another illustration of transient or permanent progression of diabetic retinopathy, similar to documented examples such as pregnancy and continuous subcutaneous insulin infusion. Specific guidelines would be needed to monitor this paradoxical phenomenon during treatment with GLP-1 agonists. Topics: Adult; Aged; Diabetes Complications; Diabetes Mellitus, Type 2; Diabetic Retinopathy; Female; Glucagon-Like Peptide 1; Humans; Insulin Infusion Systems; Male; Mass Screening; Middle Aged; Pregnancy; Pregnancy in Diabetics; Prognosis; Retrospective Studies | 2011 |
Glucagon-like peptide-1 receptor agonists for intensifying diabetes treatment.
Topics: Blood Glucose; Blood Pressure; Body Weight; Diabetes Mellitus, Type 2; Glucagon-Like Peptide 1; Glycated Hemoglobin; Humans; Hypoglycemic Agents; Randomized Controlled Trials as Topic; Treatment Outcome; United States | 2011 |
Mechanism-based population modelling for assessment of L-cell function based on total GLP-1 response following an oral glucose tolerance test.
GLP-1 is an insulinotropic hormone that synergistically with glucose gives rise to an increased insulin response. Its secretion is increased following a meal and it is thus of interest to describe the secretion of this hormone following an oral glucose tolerance test (OGTT). The aim of this study was to build a mechanism-based population model that describes the time course of total GLP-1 and provides indices for capability of secretion in each subject. The goal was thus to model the secretion of GLP-1, and not its effect on insulin production. Single 75 g doses of glucose were administered orally to a mixed group of subjects ranging from healthy volunteers to patients with type 2 diabetes (T2D). Glucose, insulin, and total GLP-1 concentrations were measured. Prior population data analysis on measurements of glucose and insulin were performed in order to estimate the glucose absorption rate. The individual estimates of absorption rate constants were used in the model for GLP-1 secretion. Estimation of parameters was performed using the FOCE method with interaction implemented in NONMEM VI. The final transit/indirect-response model obtained for GLP-1 production following an OGTT included two stimulation components (fast, slow) for the zero-order production rate. The fast stimulation was estimated to be faster than the glucose absorption rate, supporting the presence of a proximal-distal loop for fast secretion from L: -cells. The fast component (st₃) = 8.64·10⁻⁵ [mg⁻¹]) was estimated to peak around 25 min after glucose ingestion, whereas the slower component (st₄ = 26.2·10⁻⁵ [mg⁻¹]) was estimated to peak around 100 min. Elimination of total GLP-1 was characterised by a first-order loss. The individual values of the early phase GLP-1 secretion parameter (st₃) were correlated (r = 0.52) with the AUC(0-60 min.) for GLP-1. A mechanistic population model was successfully developed to describe total GLP-1 concentrations over time observed after an OGTT. The model provides indices related to different mechanisms of subject abilities to secrete GLP-1. The model provides a good basis to study influence of different demographic factors on these components, presented mainly by indices of the fast- and slow phases of GLP-1 response. Topics: Adult; Blood Glucose; Diabetes Mellitus, Type 2; Enteroendocrine Cells; Fasting; Glucagon-Like Peptide 1; Glucose Tolerance Test; Humans; Insulin; Middle Aged; Models, Statistical | 2011 |
Responses of gut microbiota and glucose and lipid metabolism to prebiotics in genetic obese and diet-induced leptin-resistant mice.
To investigate deep and comprehensive analysis of gut microbial communities and biological parameters after prebiotic administration in obese and diabetic mice.. Genetic (ob/ob) or diet-induced obese and diabetic mice were chronically fed with prebiotic-enriched diet or with a control diet. Extensive gut microbiota analyses, including quantitative PCR, pyrosequencing of the 16S rRNA, and phylogenetic microarrays, were performed in ob/ob mice. The impact of gut microbiota modulation on leptin sensitivity was investigated in diet-induced leptin-resistant mice. Metabolic parameters, gene expression, glucose homeostasis, and enteroendocrine-related L-cell function were documented in both models.. In ob/ob mice, prebiotic feeding decreased Firmicutes and increased Bacteroidetes phyla, but also changed 102 distinct taxa, 16 of which displayed a >10-fold change in abundance. In addition, prebiotics improved glucose tolerance, increased L-cell number and associated parameters (intestinal proglucagon mRNA expression and plasma glucagon-like peptide-1 levels), and reduced fat-mass development, oxidative stress, and low-grade inflammation. In high fat-fed mice, prebiotic treatment improved leptin sensitivity as well as metabolic parameters.. We conclude that specific gut microbiota modulation improves glucose homeostasis, leptin sensitivity, and target enteroendocrine cell activity in obese and diabetic mice. By profiling the gut microbiota, we identified a catalog of putative bacterial targets that may affect host metabolism in obesity and diabetes. Topics: Animals; Cecum; Colon; Diabetes Mellitus, Type 2; Dietary Fats; Enteroendocrine Cells; Gene Expression Regulation; Glucagon-Like Peptide 1; Glucose Intolerance; Gram-Negative Bacteria; Gram-Positive Bacteria; Hyperglycemia; Hyperlipidemias; Leptin; Mice; Mice, Inbred C57BL; Mice, Obese; Molecular Typing; Obesity; Prebiotics; Proglucagon; RNA, Messenger | 2011 |
[Drug industry and publication practice].
Topics: Conflict of Interest; Diabetes Mellitus, Type 2; Drug Industry; Editorial Policies; Glucagon-Like Peptide 1; Humans; Hypoglycemic Agents; Peer Review, Research; Periodicals as Topic | 2011 |
Mechanisms underlying metformin-induced secretion of glucagon-like peptide-1 from the intestinal L cell.
Glucagon-like peptide-1(7-36NH2) (GLP-1) is secreted by the intestinal L cell in response to both nutrient and neural stimulation, resulting in enhanced glucose-dependent insulin secretion. GLP-1 is therefore an attractive therapeutic for the treatment of type 2 diabetes. The antidiabetic drug, metformin, is known to increase circulating GLP-1 levels, although its mechanism of action is unknown. Direct effects of metformin (5-2000 μm) or another AMP kinase activator, aminoimidazole carboxamide ribonucleotide (100-1000 μm) on GLP-1 secretion were assessed in murine human NCI-H716, and rat FRIC L cells. Neither agent stimulated GLP-1 secretion in any model, despite increasing AMP kinase phosphorylation (P < 0.05-0.01). Treatment of rats with metformin (300 mg/kg, per os) or aminoimidazole carboxamide ribonucleotide (250 mg/kg, sc) increased plasma total GLP-1 over 2 h, reaching 37 ± 9 and 29 ± 9 pg/ml (P < 0.001), respectively, compared with basal (7 ± 1 pg/ml). Plasma activity of the GLP-1-degrading enzyme, dipeptidylpeptidase-IV, was not affected by metformin treatment. Pretreatment with the nonspecific muscarinic antagonist, atropine (1 mg/kg, iv), decreased metformin-induced GLP-1 secretion by 55 ± 11% (P < 0.05). Pretreatment with the muscarinic (M) 3 receptor antagonist, 1-1-dimethyl-4-diphenylacetoxypiperidinium iodide (500 μg/kg, iv), also decreased the GLP-1 area under curve, by 48 ± 8% (P < 0.05), whereas the antagonists pirenzepine (M1) and gallamine (M2) had no effect. Furthermore, chronic bilateral subdiaphragmatic vagotomy decreased basal secretion compared with sham-operated animals (7 ± 1 vs. 13 ± 1 pg/ml, P < 0.001) but did not alter the GLP-1 response to metformin. In contrast, pretreatment with the gastrin-releasing peptide antagonist, RC-3095 (100 μg/kg, sc), reduced the GLP-1 response to metformin, by 55 ± 6% (P < 0.01) at 30 min. These studies elucidate the mechanism underlying metformin-induced GLP-1 secretion and highlight the benefits of using metformin with dipeptidylpeptidase-IV inhibitors in patients with type 2 diabetes. Topics: Animals; Cells, Cultured; Diabetes Mellitus, Type 2; Dipeptidyl Peptidase 4; Dipeptidyl-Peptidase IV Inhibitors; Drug Therapy, Combination; Enteroendocrine Cells; Glucagon-Like Peptide 1; Humans; Hypoglycemic Agents; Metformin; Mice; Rats | 2011 |
Chlorogenic acid differentially affects postprandial glucose and glucose-dependent insulinotropic polypeptide response in rats.
Regular coffee consumption significantly lowers the risk of type 2 diabetes (T2D). Coffee contains thousands of compounds; however, the specific component(s) responsible for this reduced risk is unknown. Chlorogenic acids (CGA) found in brewed coffee inhibit intestinal glucose uptake in vitro. The objective of this study was to elucidate the mechanisms by which CGA acts to mediate blood glucose response in vivo. Conscious, unrestrained, male Sprague-Dawley rats were chronically catheterized and gavage-fed a standardized meal (59% carbohydrate, 25% fat, 12% protein), administered with or without CGA (120 mg·kg(-1)), in a randomized crossover design separated by a 3-day washout period. Acetaminophen was co-administered to assess the effects of CGA on gastric emptying. The incretins glucagon-like peptide-1 (GLP-1) and glucose-dependent insulinotropic peptide (GIP) were measured. GLP-1 response in the presence of glucose and CGA was further examined, using the human colon cell line NCI-H716. Total area under the curve (AUC) for blood glucose was significantly attenuated in rats fed CGA (p < 0.05). Despite this, no differences in plasma insulin or nonesterified fatty acids were observed, and gastric emptying was not altered. Plasma GIP response was blunted in rats fed CGA, with a lower peak concentration and AUC up to 180 min postprandially (p < 0.05). There were no changes in GLP-1 secretion in either the in vivo or in vitro study. In conclusion, CGA treatment resulted in beneficial effects on blood glucose response, with alterations seen in GIP concentrations. Given the widespread consumption and availability of coffee, CGA may be a viable prevention tool for T2D. Topics: Acetaminophen; Analgesics, Non-Narcotic; Animals; Blood Glucose; Cell Line; Chlorogenic Acid; Coffee; Diabetes Mellitus, Type 2; Drug Interactions; Enteroendocrine Cells; Gastric Emptying; Gastric Inhibitory Polypeptide; Glucagon-Like Peptide 1; Humans; Hypoglycemic Agents; Male; Postprandial Period; Random Allocation; Rats; Rats, Sprague-Dawley | 2011 |
Evaluating the long-term cost-effectiveness of liraglutide versus exenatide BID in patients with type 2 diabetes who fail to improve with oral antidiabetic agents.
The global clinical and economic burden of type 2 diabetes is substantial. Recently, clinical trials with glucagon-like peptide-1 (GLP-1) receptor agonists (liraglutide and exenatide) have shown a multifactorial clinical profile with the potential to address many of the clinical needs of patients and reduce the burden of disease.. The goal of this study was to evaluate the long-term cost-effectiveness of once-daily liraglutide versus exenatide BID in patients with type 2 diabetes who failed to improve with metformin and/or sulfonylurea, based on the results of a previous clinical trial in 6 European countries (Switzerland, Denmark, Norway, Finland, the Netherlands, and Austria).. A validated computer simulation model of diabetes was used to predict life expectancy, quality-adjusted life years (QALYs), and incidence of diabetes-related complications in patients receiving liraglutide (1.8 mg once daily) or exenatide (10 μg BID). Baseline cohort characteristics and treatment effects were derived from the Liraglutide Effect and Action in Diabetes 6 trial. Country-specific complication costs were taken from published sources. Simulations were run over 40 years from third-party payer perspectives. Future costs and clinical benefits were discounted at country-specific discount rates. Sensitivity analyses were performed.. Liraglutide was associated with improvements of 0.12 to 0.17 QALY and a reduced incidence of most diabetes-related complications versus exenatide in all settings. Evaluation of total direct medical costs (treatment plus complication costs) suggest that liraglutide was likely to cost between Euro (€) 1023 and €1866 more than exenatide over patients' lifetimes, leading to incremental cost-effectiveness ratios per QALY gained versus exenatide of: Switzerland, CHF (Swiss francs) 10,950 (€6902); Denmark, Danish krone [kr] 88,160 (€11,805); Norway, Norwegian krone [kr], 111,916 (€13,546); Finland, €8459; the Netherlands, €8119; and Austria, €8516.. Long-term projections indicated that liraglutide was associated with benefits in life expectancy, QALYs, and reduced complication rates versus exenatide. Liraglutide was cost-effective from a health care payer perspective in Switzerland, Denmark, Norway, Finland, the Netherlands, and Austria. Topics: Administration, Oral; Cohort Studies; Cost-Benefit Analysis; Diabetes Mellitus, Type 2; Drug Administration Schedule; Exenatide; Glucagon-Like Peptide 1; Humans; Hypoglycemic Agents; Liraglutide; Middle Aged; Peptides; Quality-Adjusted Life Years; Venoms | 2011 |
Interleukin-6 enhances insulin secretion by increasing glucagon-like peptide-1 secretion from L cells and alpha cells.
Exercise, obesity and type 2 diabetes are associated with elevated plasma concentrations of interleukin-6 (IL-6). Glucagon-like peptide-1 (GLP-1) is a hormone that induces insulin secretion. Here we show that administration of IL-6 or elevated IL-6 concentrations in response to exercise stimulate GLP-1 secretion from intestinal L cells and pancreatic alpha cells, improving insulin secretion and glycemia. IL-6 increased GLP-1 production from alpha cells through increased proglucagon (which is encoded by GCG) and prohormone convertase 1/3 expression. In models of type 2 diabetes, the beneficial effects of IL-6 were maintained, and IL-6 neutralization resulted in further elevation of glycemia and reduced pancreatic GLP-1. Hence, IL-6 mediates crosstalk between insulin-sensitive tissues, intestinal L cells and pancreatic islets to adapt to changes in insulin demand. This previously unidentified endocrine loop implicates IL-6 in the regulation of insulin secretion and suggests that drugs modulating this loop may be useful in type 2 diabetes. Topics: Animals; Blood Glucose; Cells, Cultured; Diabetes Mellitus, Type 2; Diet, High-Fat; Disease Models, Animal; Enteroendocrine Cells; Female; Glucagon-Like Peptide 1; Glucagon-Secreting Cells; Glucose Tolerance Test; Humans; Insulin; Insulin Secretion; Interleukin-6; Male; Mice; Mice, Inbred C57BL; Mice, Transgenic; Physical Conditioning, Animal; Signal Transduction | 2011 |
Comparison of the efficacy and tolerability profile of liraglutide, a once-daily human GLP-1 analog, in patients with type 2 diabetes ≥65 and <65 years of age: a pooled analysis from phase III studies.
Managing elderly patients with type 2 diabetes poses particular challenges, so it is important to evaluate the efficacy and tolerability profile of antidiabetic therapies specifically in this patient population.. The aim of our study was to compare the efficacy and tolerability profile of liraglutide, a GLP-1 analog, in elderly (≥65 years) and younger (<65 years) patients with type 2 diabetes.. A pooled analysis of 6 randomized, placebo-controlled, multinational trials included data from 3967 patients aged18 to 80 years with type 2 diabetes and glycosylated hemoglobin (HbA(1c)) of 7% to 11%. Of these, 552 patients ≥65 years received liraglutide 1.8 mg, liraglutide 1.2 mg, or placebo; 2231 patients <65 years received liraglutide 1.8 mg, liraglutide 1.2 mg, or placebo for 26 weeks. End points were: change in HbA(1c), fasting plasma glucose, body weight, and blood pressure: as marked to identify elements tracked for change from baseline; hypoglycemic episodes; and adverse events.. Reduction in HbA(1c) from baseline was significantly greater with liraglutide 1.8 mg versus placebo (least squares mean difference: ≥65 years, 0.91% [95% CI, 0.69-1.12]; <65 years, 1.17% [95% CI, 1.06-1.28]; both, P < 0.0001) and with liraglutide 1.2 mg versus placebo (≥65 years, 0.87% [95% CI, 0.64-1.11]; <65 years, 1.10% [95% CI, 0.98-1.22]; both, P < 0.0001). For fasting plasma glucose, comparable results were observed between liraglutide 1.8 mg or 1.2 mg and placebo for both age groups (P < 0.0001). No statistically significant difference in body weight change was seen with liraglutide between the age groups. The proportion of patients reporting minor hypoglycemia was low and appeared comparable between the ≥65-year-old (4.3%-15.2%) and <65-year-old (8%-13.2%) groups. Likewise, adverse events appeared comparable in nature and frequency.. Liraglutide provides effective glycemic control and is well tolerated in patients ≥65 and <65 years of age with type 2 diabetes. These data suggest that liraglutide may be a suitable treatment option for older patients who may have additional age-related complications. Topics: Adult; Age Factors; Aged; Aged, 80 and over; Blood Glucose; Clinical Trials, Phase III as Topic; Diabetes Mellitus, Type 2; Dose-Response Relationship, Drug; Female; Glucagon-Like Peptide 1; Glycated Hemoglobin; Humans; Hypoglycemia; Hypoglycemic Agents; Liraglutide; Male; Middle Aged; Randomized Controlled Trials as Topic; Young Adult | 2011 |
The pharmacologic basis for clinical differences among GLP-1 receptor agonists and DPP-4 inhibitors.
The incretin system plays an important role in glucose homeostasis, largely through the actions of glucose-dependent insulinotropic polypeptide (GIP) and glucagon-like peptide-1 (GLP-1). Unlike GIP, the actions of GLP-1 are preserved in patients with type 2 diabetes mellitus, which has led to the development of injectable GLP-1 receptor (GLP-1R) agonists and oral dipeptidyl peptidase-4 (DPP-4) inhibitors. GLP-1R agonists-which can be dosed to pharmacologic levels-act directly upon the GLP-1R. In contrast, DPP-4 inhibitors work indirectly by inhibiting the enzymatic inactivation of native GLP-1, resulting in a modest increase in endogenous GLP-1 levels. GLP-1R agonists generally lower the fasting and postprandial glucose levels more than DPP-4 inhibitors, resulting in a greater mean reduction in glycated hemoglobin level with GLP-1R agonists (0.4%-1.7%) compared with DPP-4 inhibitors (0.4%-1.0%). GLP-1R agonists also promote satiety and reduce total caloric intake, generally resulting in a mean weight loss of 1 to 4 kg over several months in most patients, whereas DPP-4 inhbitors are weight-neutral overall. GLP-1R agonists and DPP-4 inhibitors are generally safe and well tolerated. The glucose-dependent manner of stimulation of insulin release and inhibition of glucagon secretion by both GLP-1R agonists and DPP-4 inhibitors contribute to the low incidence of hypoglycemia. Although transient nausea occurs in 26% to 28% of patients treated with GLP-1R agonists but not DPP-4 inhibitors, this can be reduced by using a dose-escalation strategy. Other adverse events (AEs) associated with GLP-1R agonists include diarrhea, headache, and dizziness. The main AEs associated with DPP-4 inhibitors include upper respiratory tract infection, nasopharyngitis, and headache. Overall, compared with other therapies for type 2 diabetes mellitus with similar efficacy, incretin-based agents have low risk of hypoglycemia and weight gain. However, GLP-1R agonists demonstrate greater comparative efficacy and weight benefit than DPP-4 inhibitors. Topics: Blood Glucose; Body Weight; Diabetes Mellitus, Type 2; Dipeptidyl-Peptidase IV Inhibitors; Drug Hypersensitivity; Exenatide; Glucagon-Like Peptide 1; Glucagon-Like Peptide-1 Receptor; Homeostasis; Humans; Hypoglycemic Agents; Incretins; Liraglutide; Pancreatitis; Peptides; Receptors, Glucagon; Venoms | 2011 |
Short-term effects of liraglutide on visceral fat adiposity, appetite, and food preference: a pilot study of obese Japanese patients with type 2 diabetes.
To examine the effects of liraglutide, a glucagon-like peptide-1 (GLP-1) analogue, on visceral fat adiposity, appetite, food preference, and biomarkers of cardiovascular system in Japanese patients with type 2 diabetes.. The study subjects were 20 inpatients with type 2 diabetes treated with liraglutide [age; 61.2 ± 14.0 years, duration of diabetes; 16.9 ± 6.6 years, glycated hemoglobin (HbA1c); 9.1 ± 1.2%, body mass index (BMI); 28.3 ± 5.2 kg/m(2), mean ± SD]. After improvement in glycemic control by insulin or oral glucose-lowering agents, patients were switched to liraglutide. We assessed the estimated visceral fat area (eVFA) by abdominal bioelectrical impedance analysis, glycemic control by the 75-g oral glucose tolerance test (OGTT) and eating behavior by the Japan Society for the Study of Obesity questionnaire.. Treatment with liraglutide (dose range: 0.3 to 0.9 mg/day) for 20.0 ± 6.4 days significantly reduced waist circumference, waist/hip ratio, eVFA. It also significantly improved the scores of eating behavior, food preference and the urge for fat intake and tended to reduce scores for sense of hunger. Liraglutide increased serum C-peptide immunoreactivity and disposition index.. Short-term treatment with liraglutide improved visceral fat adiposity, appetite, food preference and the urge for fat intake in obese Japanese patients with type 2 diabetes. Topics: Adiposity; Aged; Appetite; Biomarkers; Body Mass Index; Diabetes Mellitus, Type 2; Electric Impedance; Feeding Behavior; Female; Food Preferences; Glucagon-Like Peptide 1; Glucose Tolerance Test; Glycated Hemoglobin; Humans; Hypoglycemic Agents; Intra-Abdominal Fat; Japan; Liraglutide; Male; Middle Aged; Obesity; Pilot Projects; Surveys and Questionnaires; Time Factors; Treatment Outcome | 2011 |
[Beyond glycemic control in type 2 diabetes. Promises and gambles of therapy with glucagon-like peptide-1 receptor agonists].
Topics: Blood Glucose; Body Mass Index; Cardiovascular Diseases; Diabetes Mellitus, Type 2; Glucagon-Like Peptide 1; Glucagon-Like Peptide-1 Receptor; Humans; Hypoglycemic Agents; Obesity; Randomized Controlled Trials as Topic; Receptors, Glucagon; Risk Factors; Treatment Outcome; Weight Loss | 2011 |
[The protection of islet β-cells in db/db mice by combination pioglitazone and glucagon like peptide-1 treatment].
To evaluate the effect of combination of liraglutide, a glucagon-like peptide-1 analogue and pioglitazone, an insulin sensitizer, on diabetic db/db mice.. Thirty-five 8-week old male db/db mice were divided into control group (n = 8), pioglitazone group (n = 9), liraglutide group (n = 9) and combined therapeutic group (n = 9), which was given normal saline 0.1 ml, 2/d, pioglitazone 24 mg×kg(-1)×d(-1) (feed contained 0.02% pioglitazone) + normal saline 0.1 ml, 2/d, liraglutide 300 mg/kg, 2/d, and pioglitazone 20 mg×kg(-1)×d(-1) (feed contained 0.02% pioglitazone) + liraglutide 300 mg/kg, 2/d, respectively. Liraglutide were given at 8:00 and 16:00 via subcutaneous injection after having been diluted with sterilized normal saline. Effect on glucose, lipid metabolism and islet β-cell preservation were assessed after 4 weeks. Oneway ANOVA was adopted for statistical analysis.. Combination therapy displayed promising anti-hyperglycemic [glycosylated hemoglobin A1c: (4.5 ± 0.6)% vs. (7.3 ± 0.4)%, P < 0.001]. Glucose tolerance were improved assessed by area under curve (AUC) of glucose by intraperitoneal glucose tolerance test (IPGTT) [(1814 ± 91) mmol×min×L(-1) vs. (4042 ± 183) mmol×min×L(-1), P < 0.001]; insulin release response to glucose were also preserved as AUC of insulin by IPGTT was higher [(1639 ± 372) µg×min×L(-1) vs.(834 ± 201) µg×min×L(-1)]. Combination therapy also reduced circulated free fatty acids and TG [(202.0 ± 20.4) µmol/L vs. (272.5 ± 21.7) µmol/L, (0.81 ± 0.28) mmol/L vs. (1.35 ± 0.21) mmol/L], and increased plasma adiponectin [(16.7 ± 2.0) mg/L vs. (10.2 ± 1.8) mg/L]. All P value < 0.05. Islet immunohistochemistry showed that combination therapy significantly increased insulin positive area were [(59.5 ± 1.5)% vs. (22.4 ± 1.5)%] and ratio of Brdu positive β-cells was three folds than vehicle-treated mice [(2.4 ± 0.5)% vs. (0.8 ± 0.3)%], both greater than each single treatment. Combined therapy significantly improved islet β cell/α cell distribution, which led to islet recovery.. Combined therapy improves glucose and lipid metabolism, preserves islet β-cell function and stimulates β-cell proliferation, greater than either liraglutide or pioglitazone treatment alone. Topics: Animals; Blood Glucose; Diabetes Mellitus, Experimental; Diabetes Mellitus, Type 2; Glucagon-Like Peptide 1; Insulin; Islets of Langerhans; Male; Mice; Mice, Inbred Strains; Pioglitazone; Thiazolidinediones | 2011 |
A pilot study of the efficacy of miglitol and sitagliptin for type 2 diabetes with a continuous glucose monitoring system and incretin-related markers.
Glucose fluctuations including robust postprandial hyperglycemia are a risk for promoting atherosclerosis and diabetic complications. The α-glucosidase inhibitors and the dipeptidyl peptidase-4 (DPP-4) inhibitors have been found to effectively decrease postprandial hyperglycemia independently. Therefore, glycemic control with the combination of these drugs is warranted.. Continuous glucose monitoring (CGM) was performed for 3 patients with type 2 diabetes and 1 control subject from the beginning to the end of the study. Medications were not administered to any of the subjects on the first day of the study. From the second day to the end of study (days 2-5), the subjects received miglitol (150 mg per day) and on days 4 and 5, sitagliptin (50 mg per day) was added to the treatment regimen. On the first, third, and fifth days of the study, blood was drawn at 0, 30, 60, 120, 180, and 240 min after breakfast for measurements of serum insulin, 1,5-anhydroglucitol (1,5-AG), plasma glucagon, glucagon-like peptide-1 (GLP-1), and glucose-dependent insulinotropic peptide (GIP).. Measurements of CGM and 1,5-AG levels showed that miglitol attenuated the escalation and fluctuation of glucose levels, and this was even more pronounced with the combination of miglitol and sitagliptin. The patterns of insulin secretion and glucagon secretion with miglitol alone or with a combination of miglitol and sitagliptin were various in the study subjects. Miglitol alone enhanced the release of GLP-1 in 1 patient with type 2 diabetes and the control subject, whereas the combination of miglitol and sitagliptin increased GLP-1 levels to varying degrees in all the subjects. Except for 1 subject, none of the subjects showed any change in GIP levels after the addition of sitagliptin, compared to the administration of miglitol alone.. In conclusion, CGM measurements revealed that a combination of the α-GI miglitol and the DPP-4 inhibitor sitagliptin effectively reduced postprandial glucose fluctuation and stabilized blood glucose levels. Completely different response patterns of insulin, glucagon, GLP-1, and GIP were observed among the study subjects with either medication alone or in combination, suggesting that individual hormone-dependent glycemic responses to the α-GI and DPP-4 inhibitors are complicated and multifactorial. Topics: 1-Deoxynojirimycin; Aged; Biomarkers; Blood Glucose; Case-Control Studies; Deoxyglucose; Diabetes Mellitus, Type 2; Dipeptidyl-Peptidase IV Inhibitors; Female; Gastric Inhibitory Polypeptide; Glucagon; Glucagon-Like Peptide 1; Glycoside Hydrolase Inhibitors; Humans; Hyperglycemia; Hypoglycemic Agents; Incretins; Insulin; Male; Middle Aged; Monitoring, Physiologic; Pilot Projects; Postprandial Period; Pyrazines; Sitagliptin Phosphate; Triazoles | 2011 |
Glucagon-like peptide-1 and diabetes.
Topics: Blood Glucose; Diabetes Mellitus, Type 2; Glucagon-Like Peptide 1; Humans; Hyperglycemia; Incretins; Insulin; Signal Transduction | 2011 |
Efficacy of liraglutide in a patient with type 2 diabetes and cryptogenic cirrhosis.
In this work Author presents a case report of a female patient of 65 years old who had suffered from type 2 diabetes mellitus and from concomitant cryptogenic cirrhosis. She was treated with liraglutide, an analogue of human GLP-1, obtaining an optimal metabolic control associated with an improved clinical condition for the cirrhosis. Topics: Aged; Diabetes Mellitus, Type 2; Female; Glucagon-Like Peptide 1; Humans; Incretins; Liraglutide; Liver; Liver Cirrhosis | 2011 |
Efficacy and tolerability of liraglutide in combination with other antidiabetic drugs in type 2 diabetes.
We present a collection case report performed in 29 inadequately controlled diabetic and obese outpatients. The aim of this study was to verify metabolic effects of liraglutide in combination with other antidiabetic drugs. Across this study, liraglutide effectively and rapidly improves glycemic control (both fasting glycemia and HbAlc), body weight and systolic blood pressure, thus promoting the achievement of therapeutic targets proposed by the American Diabetes Association and European Association for the study of Diabetes and reducing cardiovascular risk profile of diabetic patients. (www.actabiomedica.it). Topics: Blood Pressure; Body Weight; Diabetes Mellitus, Type 2; Drug Therapy, Combination; Female; Glucagon-Like Peptide 1; Glycated Hemoglobin; Humans; Hypoglycemic Agents; Incretins; Liraglutide; Male; Middle Aged | 2011 |
The dipeptidyl peptidase IV inhibitor NVP-DPP728 reduces plasma glucagon concentration in cats.
Glucagon-like peptide-1 (GLP-1) analogues and inhibitors of its degrading enzyme, dipeptidyl peptidase IV (DPPIV), are interesting therapy options in human diabetics because they increase insulin secretion and reduce postprandial glucagon secretion. Given the similar pathophysiology of human type 2 and feline diabetes mellitus, this study investigated whether the DPPIV inhibitor NVP-DPP728 reduces plasma glucagon levels in cats. Intravenous glucose tolerance tests (ivGTT; 0.5 g/kg glucose after 12 h fasting) and a meal response test (test meal of 50% of average daily food intake, offered after 24 h fasting) were performed in healthy experimental cats. NVP-DPP728 (0.5-2.5 mg/kg i.v. or s.c.) significantly reduced glucagon output in all tests and increased insulin output in the ivGTT. Follow-up studies will investigate the potential usefulness as therapy in diabetic cats. Topics: Animals; Cats; Diabetes Mellitus, Type 2; Dipeptidyl-Peptidase IV Inhibitors; Disease Models, Animal; Glucagon; Glucagon-Like Peptide 1; Humans; Insulin; Insulin Secretion; Male; Nitriles; Pyrrolidines | 2010 |
Exendin-4 exerts osteogenic actions in insulin-resistant and type 2 diabetic states.
Poor control of glucose homeostasis accounts for diabetes-related bone loss. Incretins - GLP-1 and GIP - have been proposed to affect bone turnover. GLP-1, apart from its anti-diabetic and other actions, has shown to exert a bone anabolic effect in streptozotocin-induced type 2 diabetic (T2D) and fructose-induced insulin-resistant (IR) rats. Exendin-4 (Ex-4), a peptide of non-mammalian nature, is sharing with GLP-1 part of its structural sequence, and also several glucoregulatory effects in mammals in an even more efficient manner. We have explored the effect of continuous administration (3 days by osmotic pump) of Ex-4 or saline (control) on bone turnover factors and bone structure in T2D and IR rats, compared to N, and the possible interaction of Ex-4 with the Wnt signalling pathway. Blood was taken before and after treatment for plasma measurements; tibiae and femurs were collected for gene expression of bone markers (RT-PCR) and structure (microCT) analysis; we also measured the mRNA levels of LRP5 - an activator of the Wnt pathway - and those of DKK1 and sclerostin (SOST) - both blockers of LRP5 activity. Compared to N-control, plasma glucose and insulin were respectively higher and lower in T2D; osteocalcin (OC) and tartrate-resistant alkaline phosphatase 5b (TRAP5b) were lower; after Ex-4, these turnover markers were further reduced in T2D and IR, while TRAP5b increased in N. Bone OC, osteoprogeterin (OPG) and receptor activator of NF-kB ligand (RANKL) mRNA were lower in T2D and IR; Ex-4 increased OC in all groups and OPG in N and IR, reduced RANKL in N and T2D but increased it in IR; the LRP5/DKK1 and LRP5/SOST mRNA ratios were similarly decreased in T2D, but in IR, the latter ratio was reduced while the former was increased; after Ex-4, both ratios augmented in N, and that of LRP5/DKK1 tended to normalize in T2D and IR. In conclusion, Ex-4 exerts osteogenic effects in T2D and IR models, and interacts with the Wnt pathway to promote bone formation. Topics: Animals; Blood Glucose; Bone Morphogenetic Proteins; Diabetes Mellitus, Experimental; Diabetes Mellitus, Type 2; Exenatide; Fructose; Gastric Inhibitory Polypeptide; Genetic Markers; Glucagon-Like Peptide 1; Hypoglycemic Agents; Insulin; Insulin Resistance; Intercellular Signaling Peptides and Proteins; LDL-Receptor Related Proteins; Low Density Lipoprotein Receptor-Related Protein-5; Male; Osteocalcin; Osteogenesis; Osteoporosis; Peptides; Rats; Rats, Wistar; Sweetening Agents; Venoms; Wnt Proteins | 2010 |
Glucagon-like peptide-1 response to meals and post-prandial hyperglycemia in Type 2 diabetic patients.
The impaired response of glucagonlike peptide-1 (GLP-1) to meals in diabetic patients can contribute to the pathogenesis of impaired insulin secretion and post-prandial hyperglycemia. This study is aimed at the assessment of the relationship between meal-induced GLP-1 and post-prandial hyperglycemia in Type 2 diabetic patients.. Twenty-one drug-naïve Type 2 diabetic patients were studied. Blood glucose and active GLP-1 levels were measured 0, 30, 60, 90, and 120 min after a standard test meal. A continuous glucose monitoring (CGM) system was applied for the following 3 days. Nutrient intake at each meal was calculated on the basis of patients' food records. For each patient, post-prandial 120-min glucose incremental area under the curve (iAUC) was included in linear regression model exploring its relationship with total energy and carbohydrate intake, and the angular coefficient for total energy (EAC) and carbohydrate (CAC) was calculated.. GLP-1 levels peaked 30 min after the test meal. Logarithmically transformed 60-min GLP-1 iAUC showed a significant inverse correlation with glycated hemoglobin (HbA1c) (p<0.01). A significant inverse correlation of 60-min GLP-1 iAUC was also observed with EAC and CAC (both p<0.01), meaning that patients with a lower GLP-1 response to the test meal had a higher increment of post-prandial glucose for each additional unit of total energy or carbohydrate intake.. In Type 2 diabetic patients, a lower GLP-1 response to meals is associated with a higher HbA1c, and with a greater degree of meal-induced hyperglycemia, both in a meal test and during CGM in "real-life" conditions. Topics: Area Under Curve; Blood Glucose; Blood Glucose Self-Monitoring; Diabetes Mellitus, Type 2; Eating; Female; Glucagon-Like Peptide 1; Glycated Hemoglobin; Humans; Hyperglycemia; Linear Models; Male; Middle Aged; Postprandial Period | 2010 |
The utility of [(11)C] dihydrotetrabenazine positron emission tomography scanning in assessing beta-cell performance after sleeve gastrectomy and duodenal-jejunal bypass.
The aim of this study was to evaluate the effect of sleeve gastrectomy (SG) and duodenal-jejunal bypass (DJB) on glucose homeostasis and to evaluate the utility of positron emission tomography (PET) scanning for assessing beta-cell mass.. Goto-Kakizaki rats were divided into 4 groups: control, sham, SG, or DJB. Oral glucose tolerance, insulin, and glucagon-like peptide-1 (GLP-1) were measured before and after surgery. Before and 90 days after treatment, [(11)C] DTBZ micro PET scanning was performed.. The control and sham animals gained more weight compared with SG and DJB animals (P < or = .05). Compared with control animals, the glucose area under the curve was lower in DJB animals 30 and 45 days after operations (P < or = .05). At killing, GLP-1 levels were greater in the DJB group compared with sham and SG (P < or = .05), whereas insulin levels were greater in both DJB and SG compared with sham (P < or = .05). With PET scanning, the 90-day posttreatment mean vesicular monoamine transporter type 2 binding index was greatest in the DJB animals (2.45) compared with SG (1.17), both of which were greater than baseline control animals (0.81).. In type 2 diabetic rodents, DJB leads to improved glucose homeostasis and an increase in VMAT2 density as measured by PET scanning. Topics: Animals; Bariatric Surgery; Carbon Radioisotopes; Diabetes Mellitus, Experimental; Diabetes Mellitus, Type 2; Duodenum; Gastrectomy; Glucagon-Like Peptide 1; Glucose; Glucose Tolerance Test; Homeostasis; Insulin; Insulin-Secreting Cells; Jejunum; Positron-Emission Tomography; Rats; Rats, Inbred Strains; Tetrabenazine; Vesicular Monoamine Transport Proteins | 2010 |
Intact glucagon-like peptide-1 levels are not decreased in Japanese patients with type 2 diabetes.
Impaired secretion of glucagon-like peptide 1 (GLP-1) has been suggested to contribute to the deficient incretin effect in patients with type 2 diabetes mellitus (T2DM). Recent studies, however, have not always supported this notion. Since Japanese patients with T2DM usually have severe impairment in the earlyphase of insulin secretion, the measurement of incretin secretions in Japanese T2DM patients would be useful for assessing the association between incretin levels and insulin secretion. We conducted an oral glucose tolerance test (75 g) (OGTT) and meal tolerance test (480 kcal) (MTT) for subjects with normal glucose tolerance (NGT, n=12), subjects with impaired glucose tolerance (IGT, n=7), and T2DM patients (n=21). The tests were carried out over 120-min study periods on separate occasions. Intact GLP-1, GIP, and dipeptidyl peptidase (DPP)-IV were measured by ELISA. T2DM exhibited an impaired early phase of insulin secretion and a reduction in glucagon suppression. There were no significant differences in GLP-1 or GIP levels at each sampling time among NGT, IGT, and T2DM after the ingestions; hence the incremental areas under the curve (IAUC) for the three groups were quite similar. The levels of DPP-IV, a limiting enzyme for the degradation of incretins, were comparable among the three groups. The GLP-1-IAUC was not correlated with IAUCs of insulin, C-peptide, or glucagon determined by the OGTT or the MTT. We concluded that intact GLP-1 levels are comparable between non-diabetics and T2DM, suggesting that impaired insulin secretion in Japanese T2DM is not attributable to defect in GLP-1 secretion. Topics: Adult; Aged; Asian People; Diabetes Mellitus, Type 2; Dipeptidyl Peptidase 4; Gastric Inhibitory Polypeptide; Glucagon-Like Peptide 1; Glucose Intolerance; Glucose Tolerance Test; Humans; Incretins; Insulin; Insulin Secretion; Middle Aged | 2010 |
Postprandial diabetic glucose tolerance is normalized by gastric bypass feeding as opposed to gastric feeding and is associated with exaggerated GLP-1 secretion: a case report.
To examine after gastric bypass the effect of peroral versus gastroduodenal feeding on glucose metabolism.. A type 2 diabetic patient was examined on 2 consecutive days 5 weeks after gastric bypass. A standard liquid meal was given on the first day into the bypassed gastric remnant and on the second day perorally. Plasma glucose, insulin, C-peptide, glucagon, incretin hormones, peptide YY, and free fatty acids were measured.. Peroral feeding reduced 2-h postprandial plasma glucose (7.8 vs. 11.1 mmol/l) and incremental area under the glucose curve (iAUC) (0.33 vs. 0.49 mmol . l(-1) . min(-1)) compared with gastroduodenal feeding. beta-Cell function (iAUC(Cpeptide/Glu)) was more than twofold improved during peroral feeding, and the glucagon-like peptide (GLP)-1 response increased nearly fivefold.. Improvement in postprandial glucose metabolism after gastric bypass is an immediate and direct consequence of the gastrointestinal rearrangement, associated with exaggerated GLP-1 release and independent of changes in insulin sensitivity, weight loss, and caloric restriction. Topics: Area Under Curve; Blood Glucose; C-Peptide; Diabetes Mellitus, Type 2; Enteral Nutrition; Fatty Acids, Nonesterified; Gastric Bypass; Glucagon; Glucagon-Like Peptide 1; Humans; Incretins; Male; Middle Aged; Obesity, Morbid; Peptide YY; Postoperative Period; Postprandial Period | 2010 |
Reduced plasma levels of glucagon-like peptide-1 in elderly men are associated with impaired glucose tolerance but not with coronary heart disease.
Besides the insulinotropic effects of glucagon-like peptide-1 (GLP-1) mimetics, their effects on endothelial dysfunction and myocardial ischaemia are of interest. No previous study has investigated associations between plasma levels of GLP-1 and CHD.. We investigated longitudinal relationships of fasting GLP-1 with the dynamic GLP-1 response after OGTT (difference between 60 min OGTT-stimulated and fasting GLP-1 levels [DeltaGLP-1]) and CHD in a population-based cohort of 71-year-old men. In the same cohort, we also cross-sectionally investigated the association between stimulated GLP-1 levels and: (1) cardiovascular risk factors (blood pressure, lipids, urinary albumin, waist circumference and insulin sensitivity index [M/I] assessed by euglycaemic-hyperinsulinaemic clamp); and (2) impaired glucose tolerance (IGT) and type 2 diabetes mellitus.. During the follow-up period (maximum 13.8 years), of 294 participants with normal glucose tolerance (NGT), 69 experienced a CHD event (13.8 years), as did 42 of 141 with IGT and 32 of 74 with type 2 diabetes mellitus. DeltaGLP-1 did not predict CHD (HR 1.0, 95% CI 0.52-2.28). The prevalence of IGT was associated with DeltaGLP-1, lowest vs highest quartile (OR 0.3, 95% CI 0.12-0.58), with no such association for type 2 diabetes mellitus (OR 1.0, 95% CI 0.38-2.86). M/I was significantly associated with DeltaGLP-1 in the type 2 diabetes mellitus group (r = 0.38, p < 0.01), but not in the IGT (r = 0.11, p = 0.28) or NGT (r = 0.10, p = 0.16) groups.. Impaired GLP-1 secretion is associated with IGT, but not with type 2 diabetes mellitus. This finding in the latter group might be confounded by oral glucose-lowering treatment. GLP-1 does not predict CHD. Although DeltaGLP-1 was associated with insulin sensitivity in the type 2 diabetes mellitus group, GLP-1 does not seem to be a predictor of CHD in insulin-resistant patients. Topics: Aged; Albuminuria; Blood Pressure; Cardiovascular Diseases; Cholesterol; Cohort Studies; Coronary Disease; Diabetes Mellitus, Type 2; Fasting; Follow-Up Studies; Glucagon-Like Peptide 1; Glucose Clamp Technique; Glucose Intolerance; Glucose Tolerance Test; Humans; Insulin; Male; Survival Analysis; Waist Circumference | 2010 |
Liraglutide, but not vildagliptin, restores normoglycaemia and insulin content in the animal model of type 2 diabetes, Psammomys obesus.
In order to investigate the effect and mechanism of liraglutide and vildagliptin in diabetic Psammomys obesus, we examined proliferation and apoptosis of beta-cells, beta-cell mass (BCM), and pancreatic insulin content after zero, six and fourteen days of treatment compared to control groups. One group of animals was kept on low-energy diet and seven groups were given high-energy diet (HED) that induced diabetes over a four week period. Non-fasting morning blood glucose, body weight, HbA(1C) and pancreatic insulin content were measured and beta cell mass (BCM), proliferation and apoptosis frequencies were determined using stereological point counting. Liraglutide significantly reduced blood glucose and even normalized it in all animals treated for six days and in 11 out of 17 animals treated for fourteen days. HED increased BCM and treatment with liraglutide did not change this. However, compared to the vehicle-treated animals pancreatic insulin content was normalized in animals treated for six and fourteen days with liraglutide. In contrast, vildagliptin, in doses causing full inhibition of plasma DPP-IV activity, neither reduced blood glucose nor altered HED-induced increases in BCM or pancreatic insulin content. These results suggest that liraglutide restores normoglycaemia and improves glycaemic control in P. obesus by increasing their insulin content and improving the function of the beta-cells. In contrast, vildagliptin does not improve glycaemic control in P. obesus nor affect beta-cell insulin content. Topics: Adamantane; Animals; Blood Glucose; Diabetes Mellitus, Type 2; Dipeptidyl-Peptidase IV Inhibitors; Disease Models, Animal; Dose-Response Relationship, Drug; Female; Gerbillinae; Glucagon-Like Peptide 1; Immunohistochemistry; Insulin; Liraglutide; Male; Nitriles; Pancreas; Pyrrolidines; Reference Standards; Vildagliptin | 2010 |
Effects of exenatide on systolic blood pressure in subjects with type 2 diabetes.
The majority of patients with type 2 diabetes mellitus have blood pressure (BP) exceeding the recommended value of <130/80 mm Hg. Optimal control of hyperglycemia and hypertension has been shown to reduce the incidence of macrovascular and microvascular complications due to diabetes. Treatment with the GLP-1 receptor agonist exenatide, previously demonstrated to reduce hemoglobin A(1C) and weight in subjects with type 2 diabetes, was associated with BP reduction in several studies.. This analysis explored the effects of exenatide vs. placebo or insulin on BP measurements in pooled data from six trials including 2,171 subjects studied for at least 6 months.. Overall, 6 months of exenatide treatment was associated with a significantly greater reduction in systolic BP (SBP) compared with placebo (least squares mean (s.e.): difference of -2.8 mm Hg (0.75); P = 0.0002) or insulin (difference of -3.7 mm Hg (0.85); P < 0.0001). No significant intergroup differences in diastolic BP (DBP) were observed. The majority of the intergroup difference was observed in subjects with SBP > or = 130 mm Hg (difference of -3.8 mm Hg (1.08) from placebo: P = 0.0004; difference of -4.0 mm Hg (1.01) from insulin; P < 0.0001). The largest intertreatment differences between exenatide and comparators were observed in subjects with SBP >/=150 mm Hg. Similar responses were observed in African-American subjects. A weak correlation between the amount of weight lost and reduction in SBP was found (r = 0.09, P = 0.002) for exenatide-treated subjects.. These results support the need for a prospective, randomized, controlled study of BP changes during exenatide treatment in patients with hypertension and type 2 diabetes. Topics: Blood Pressure; Databases, Factual; Diabetes Mellitus, Type 2; Exenatide; Female; Glucagon-Like Peptide 1; Humans; Hypertension; Hypoglycemic Agents; Male; Middle Aged; Peptides; Randomized Controlled Trials as Topic; Retrospective Studies; Venoms | 2010 |
Glucagon-like peptide-1 analogues enhance synaptic plasticity in the brain: a link between diabetes and Alzheimer's disease.
Type 2 diabetes has been identified as a risk factor for patients with Alzheimer's disease. Insulin signalling is often impaired in Alzheimer's disease, contributing to the neurodegenerative process. One potential strategy to help prevent this is the normalisation of insulin signalling in the brain. Therefore, the present study was designed to test the effects of novel enzyme-resistant analogues of the insulin-releasing incretin hormone, glucagon-like peptide 1 (GLP-1). The effects of Liraglutide (Victoza) and other novel GLP-1 analogues were tested on synaptic plasticity (LTP) in area CA1 of the hippocampus. At a dose of 15nmol in 5microl i.c.v., Liraglutide (P<0.005), Asp(7)GLP-1 (P<0.001), N-glyc-GLP-1 (P<0.01), and Pro(9)GLP-1 (P<0.001). In contrast, the GLP-1 receptor antagonist exendin(9-39)amide impaired LTP (P<0.001). Co-injection of exendin(9-39) and Liraglutide showed no effect on LTP. These results clearly demonstrate that Liraglutide and other GLP-1 analogues elicit effects on neurotransmission in the brain. Furthermore, GLP-1 peptides are not only effective in modulating insulin-release and achieving glycaemic control in type 2 diabetes, but are also effective in modulating synaptic plasticity. These findings are consistent with our previous observations that the novel analogue (Val(8))GLP-1 enhances LTP and reverses the impairments of LTP induced by beta-amyoid fragments. Therefore, the drug effects seen here could potentially ameliorate the impairments in neuronal communication and cognitive processes observed in Alzheimer's disease. Topics: Alzheimer Disease; Animals; Brain; Diabetes Mellitus, Type 2; Glucagon-Like Peptide 1; Liraglutide; Long-Term Potentiation; Male; Rats; Rats, Wistar; Synapses | 2010 |
The fatty acid conjugated exendin-4 analogs for type 2 antidiabetic therapeutics.
Improved glucagon-like peptide-1 (GLP-1) receptor activation is considered one of the most effective targets for antidiabetic therapy. For this purpose, we modified the GLP-1 analog of exendin-4 using two fatty acids (FA) either lauric acid (LUA, C12) or palmitic acid (PAA, C16) at its two lysine residues, to produce; Lys(12)-FA-Exendin-4 (FA-M2), Lys(27)-FA-Exendin-4 (FA-M1), or Lys(12,27)-diBA-Exendin-4 (FA-Di). The structural, biological, and pharmaceutical characteristics of these exendin-4 analogs were then investigated. Biological activity tests demonstrated that LUA-M1 had well-preserved in vivo antidiabetic activity and in vitro insulinotropic activity with minimum GLP-1 receptor binding affinity loss as compared with exendin-4. Furthermore, pharmacokinetic studies in rats revealed that s.c. administration of LUA-M1 significantly enhanced pharmacokinetic parameters, such as, elimination half-life, mean residence time, and AUC values as compared with exendin-4. The protracted antidiabetic effects of LUA-M1 were also confirmed by prolonged normoglycemia observed in type 2 diabetic mice (20nmol/mouse single injection of exendin-4 or LUA-M1 induced normoglycemia for 6 or 24h, respectively). These findings suggest that FA conjugated exendin-4s should be considered potential candidates for the treatment of diabetes. Topics: Animals; Antigens; Diabetes Mellitus; Diabetes Mellitus, Type 2; Exenatide; Fatty Acids; Glucagon-Like Peptide 1; Glucagon-Like Peptide-1 Receptor; Half-Life; Hypoglycemic Agents; Lysine; Male; Mice; Mice, Inbred C57BL; Mice, Mutant Strains; Palmitic Acid; Peptides; Rats; Rats, Sprague-Dawley; Receptors, Glucagon; Venoms | 2010 |
Incretin-based therapies for the treatment of type 2 diabetes: evaluation of the risks and benefits.
Topics: Diabetes Mellitus, Type 2; Drug Administration Schedule; Exenatide; Glucagon-Like Peptide 1; Humans; Hypoglycemic Agents; Incidence; Incretins; Peptides; Prevalence; Risk Assessment; Treatment Outcome; Venoms | 2010 |
GLP-1-based therapy for diabetes: what you do not know can hurt you.
Topics: Clinical Trials as Topic; Diabetes Mellitus, Type 2; Glucagon-Like Peptide 1; Humans; Hypoglycemic Agents; Obesity; Pancreatic Neoplasms; PPAR gamma; Risk Assessment; Safety | 2010 |
Population pharmacokinetics of liraglutide, a once-daily human glucagon-like peptide-1 analog, in healthy volunteers and subjects with type 2 diabetes, and comparison to twice-daily exenatide.
The once-daily human glucagon-like peptide-1 (GLP-1) analog, liraglutide, was recently shown to provide improved glycemic control in subjects with type 2 diabetes (T2D) compared with exenatide. The aim of this work is to estimate the population pharmacokinetics of liraglutide and make a comparison to the pharmacokinetic profile of exenatide. Pharmacokinetic data from 5 published studies of subcutaneous and intravenous administration of liraglutide to healthy volunteers (HV) and subjects with T2D were used to develop a population pharmacokinetic model in NONMEM. Exenatide data came from a published study in T2D. Liraglutide pharmacokinetics were adequately described using a 1-compartment model with sequential zero- and first-order absorption. The pharmacokinetic profile of once-daily liraglutide showed considerably smaller peak-to-trough fluctuations compared with twice-daily exenatide. A small difference in the estimates of absorption parameters was found between HV and subjects with T2D but was not clinically relevant. It was concluded that pharmacokinetic profiles estimated by modeling showed that liraglutide has pharmacokinetic properties consistent with once-daily dosing in humans and provides better pharmacokinetic coverage in comparison with twice-daily exenatide. Furthermore, no clinically relevant differences were found in liraglutide pharmacokinetics between HV and subjects with T2D. Topics: Clinical Trials as Topic; Diabetes Mellitus, Type 2; Drug Administration Schedule; Exenatide; Glucagon-Like Peptide 1; Humans; Hypoglycemic Agents; Liraglutide; Metabolic Clearance Rate; Models, Biological; Peptides; Venoms | 2010 |
Similar incretin secretion in obese and non-obese Japanese subjects with type 2 diabetes.
Incretin secretion and effect on insulin secretion are not fully understood in patients with type 2 diabetes. We investigated incretin and insulin secretion after meal intake in obese and non-obese Japanese patients with type 2 diabetes compared to non-diabetic subjects. Nine patients with type 2 diabetes and 5 non-diabetic subjects were recruited for this study. Five diabetic patients were obese (BMI > or = 25) and 4 patients were non-obese (BMI < 25). In response to a mixed meal test, the levels of immunoreactive insulin during 15-90 min and C-peptide during 0-180 min in non-obese patients were significantly lower than those in obese patients. Total GLP-1 and active GIP levels showed no significant difference between obese and non-obese patients throughout the meal tolerance test. In addition, there were no significant differences between diabetic patients and non-diabetic subjects. In conclusion, incretin secretion does not differ between Japanese obese and non-obese patients with type 2 diabetes and non-diabetic subjects. Topics: Body Mass Index; C-Peptide; Diabetes Mellitus, Type 2; Glucagon-Like Peptide 1; Humans; Incretins; Insulin; Insulin Secretion; Middle Aged; Obesity | 2010 |
The glucagonostatic and insulinotropic effects of glucagon-like peptide 1 contribute equally to its glucose-lowering action.
Glucagon-like peptide 1 (GLP-1) exerts beneficial antidiabetic actions via effects on pancreatic beta- and alpha-cells. Previous studies have focused on the improvements in beta-cell function, while the inhibition of alpha-cell secretion has received less attention. The aim of this research was to quantify the glucagonostatic contribution to the glucose-lowering effect of GLP-1 infusions in patients with type 2 diabetes.. Ten male patients with well-regulated type 2 diabetes (A1C 6.9 +/- 0.8%, age 56 +/- 10 years, BMI 31 +/- 3 kg/m(2) [means +/- SD]) were subjected to five 120-min glucose clamps at fasting plasma glucose (FPG) levels. On day 1, GLP-1 was infused to stimulate endogenous insulin release and suppress endogenous glucagon. On days 2-5, pancreatic endocrine clamps were performed using somatostatin infusions of somatostatin and/or selective replacement of insulin and glucagon; day 2, GLP-1 plus basal insulin and glucagon (no glucagon suppression or insulin stimulation); day 3, basal insulin only (glucagon deficiency); day 4, basal glucagon and stimulated insulin; and day 5, stimulated insulin. The basal plasma glucagon levels were chosen to simulate portal glucagon levels.. Peptide infusions produced the desired hormone levels. The amount of glucose required to clamp FPG was 24.5 +/- 4.1 (day 1), 0.3 +/- 0.2 (day 2), 10.6 +/- 1.1 (day 3), 11.5 +/- 2.7 (day 4), and 24.5 +/- 2.6 g (day 5) (day 2 was lower than days 3 and 4, which were both similar and lower than days 1 and 5).. We concluded that insulin stimulation (day 4) and glucagon inhibition (day 3) contribute equally to the effect of GLP-1 on glucose turnover in patients with type 2 diabetes, and these changes explain the glucose-lowering effect of GLP-1 (day 5 vs. day 1). Topics: Adult; Analysis of Variance; Area Under Curve; Blood Glucose; Diabetes Mellitus, Type 2; Glucagon; Glucagon-Like Peptide 1; Glucose Clamp Technique; Humans; Insulin; Insulin Secretion; Male; Middle Aged; Time Factors; Treatment Outcome | 2010 |
A novel antihypertensive effect of exenatide, a GLP-1 agonist.
Topics: Antihypertensive Agents; Blood Pressure; Diabetes Mellitus, Type 2; Exenatide; Glucagon-Like Peptide 1; Humans; Hypoglycemic Agents; Peptides; Vasodilation; Vasodilator Agents; Venoms | 2010 |
Weighing risks and benefits of liraglutide--the FDA's review of a new antidiabetic therapy.
Topics: Animals; Biomarkers; Calcitonin; Cardiovascular Diseases; Diabetes Mellitus, Type 2; Drug Approval; Drug Therapy, Combination; Glucagon-Like Peptide 1; Humans; Hypoglycemic Agents; Liraglutide; Pancreatitis; Risk Factors; Rodentia; Thyroid Neoplasms; United States; United States Food and Drug Administration | 2010 |
Induction of insulin receptor substrate-2 expression by Fc fusion to exendin-4 overexpressed in E. coli: a potential long-acting glucagon-like peptide-1 mimetic.
Exendin-4 (Ex-4), a peptide secreted from the salivary glands of the Gila monster lizard, can increase pancreatic beta-cell growth and insulin secretion by activating glucagon-like peptide-1 receptor. In this study, we expressed a fusion protein consisting of exendin-4 and the human immunoglobulin heavy chain (Ex-4/IgG-Fc) in E. coli and explored its potential therapeutic use for the treatment of insulin-resistant type 2 diabetes. Here, we show that the Ex-4/IgG-Fc fusion protein induces expression of insulin receptor substrate-2 in rat insulinoma INS-1 cells. Our findings therefore suggest that Ex-4/IgG-Fc overexpressed in E. coli could be used as a potential, long-acting glucagon-like peptide-1 mimetic. Topics: Animals; Cell Line, Tumor; Diabetes Mellitus, Type 2; Escherichia coli; Exenatide; Glucagon-Like Peptide 1; Glucagon-Like Peptide-1 Receptor; Humans; Hypoglycemic Agents; Immunoglobulin Fc Fragments; Immunoglobulin Heavy Chains; Insulin Receptor Substrate Proteins; Insulin Resistance; Peptides; Rats; Receptors, Glucagon; Recombinant Fusion Proteins; Venoms | 2010 |
Dipeptidyl-peptidase 4 and attractin expression is increased in circulating blood monocytes of obese human subjects.
Dipeptidyl-peptidase (DPP)-4, which catalizes the degradation of the insulinotropic incretin glucagon-like-peptide (GLP)-1, and the DPP-4 like enzyme attractin are involved in activation of T-lymphocytes and monocytes. Recently, it has been demonstrated, that the risk for certain infections is increased in type 2 diabetic patients under DPP-4 inhibitor treatment. The aim of the present study was to examine the expression of DPP-4 and attractin in circulating blood monocytes of obese and type 2 diabetic subjects. Monocytes were isolated by CD14-antibody based magnetic cell sorting from blood samples of 17 lean controls, 20 obese, non-diabetic subjects and 19 obese patients with type 2 diabetes. FACS analysis was performed to test purity of the cell preparations. Expression was measured by multiplex RT-PCR on RNA-level. DPP-4 and attractin were detectable in human circulating monocytes with attractin being expressed at higher levels compared to DPP-4. Both enzymes were significantly higher expressed in circulating blood monocytes of obese subjects compared to lean controls. In contrast, type 2 diabetes did not significantly affect expression levels. Finally, neither DPP-4 nor attractin expression was altered by sitagliptin or insulin treatment. In conclusion, our data demonstrate, that expressions of DPP-4 and attractin in circulating blood monocytes of human subjects are influenced by metabolic abnormalities with obesity being an important factor. Topics: Body Mass Index; Diabetes Mellitus, Type 2; Dipeptidyl Peptidase 4; Dipeptidyl-Peptidase IV Inhibitors; Female; Glucagon-Like Peptide 1; Humans; Hypoglycemic Agents; Insulin; Lipopolysaccharide Receptors; Male; Membrane Proteins; Middle Aged; Monocytes; Obesity; Pyrazines; Sitagliptin Phosphate; Triazoles | 2010 |
Effect of endogenous GLP-1 on insulin secretion in type 2 diabetes.
The incretins glucagon-like peptide-1 (GLP-1) and glucose-dependent insulinotropic polypeptide (GIP) account for up to 60% of postprandial insulin release in healthy people. Previous studies showed a reduced incretin effect in patients with type 2 diabetes but a robust response to exogenous GLP-1. The primary goal of this study was to determine whether endogenous GLP-1 regulates insulin secretion in type 2 diabetes.. Twelve patients with well-controlled type 2 diabetes and eight matched nondiabetic subjects consumed a breakfast meal containing D-xylose during fixed hyperglycemia at 5 mmol/l above fasting levels. Studies were repeated, once with infusion of the GLP-1 receptor antagonist, exendin-(9-39) (Ex-9), and once with saline.. The relative increase in insulin secretion after meal ingestion was comparable in diabetic and nondiabetic groups (44 +/- 4% vs. 47 +/- 7%). Blocking the action of GLP-1 suppressed postprandial insulin secretion similarly in the diabetic and nondiabetic subjects (25 +/- 4% vs. 27 +/- 8%). However, Ex-9 also reduced the insulin response to intravenous glucose (25 +/- 5% vs. 26 +/- 7%; diabetic vs. nondiabetic subjects), when plasma GLP-1 levels were undetectable. The appearance of postprandial ingested d-xylose in the blood was not affected by Ex-9.. These findings indicate that in patients with well-controlled diabetes, the relative effects of enteral stimuli and endogenous GLP-1 to enhance insulin release are retained and comparable with those in nondiabetic subjects. Surprisingly, GLP-1 receptor signaling promotes glucose-stimulated insulin secretion independent of the mode of glucose entry. Based on rates of D-xylose absorption, GLP-1 receptor blockade did not affect gastric emptying of a solid meal. Topics: Adult; Blood Glucose; Body Mass Index; Diabetes Mellitus, Type 2; Dietary Carbohydrates; Female; Glucagon-Like Peptide 1; Glucose; Humans; Insulin; Insulin Secretion; Insulin-Secreting Cells; Male; Middle Aged; Postprandial Period; Reference Values; Xylose | 2010 |
Ileal interposition surgery improves glucose and lipid metabolism and delays diabetes onset in the UCD-T2DM rat.
Bariatric surgery has been shown to reverse type 2 diabetes; however, mechanisms by which this occurs remain undefined. Ileal interposition (IT) is a surgical model that isolates the effects of increasing delivery of unabsorbed nutrients to the lower gastrointestinal tract. In this study we investigated effects of IT surgery on glucose tolerance and diabetes onset in UCD-T2DM (University of California at Davis type 2 diabetes mellitus) rats, a polygenic obese animal model of type 2 diabetes.. IT or sham surgery was performed on 4-month-old male UCD-T2DM rats. All animals underwent oral glucose tolerance testing (OGTT). A subset was killed 2 months after surgery for tissue analyses. The remainder was followed until diabetes onset and underwent oral fat tolerance testing (OFTT).. IT surgery delayed diabetes onset by 120 +/- 49 days compared with sham surgery (P < .05) without a difference in body weight. During OGTT, IT-operated animals exhibited lower plasma glucose excursions (P < .05), improved early insulin secretion (P < .01), and 3-fold larger plasma glucagon-like peptide-1(7-36) (GLP-1(7-36)) excursions (P < .001), and no difference in glucose-dependent insulinotropic polypeptide responses compared with sham-operated animals. Total plasma peptide YY (PYY) excursions during OFTT were 3-fold larger in IT-operated animals (P < .01). IT-operated animals exhibited lower adiposity (P < .05), smaller adipocyte size (P < .05), 25% less ectopic lipid deposition, lower circulating lipids, and greater pancreatic insulin content compared with sham-operated animals (P < .05).. IT surgery delays the onset of diabetes in UCD-T2DM rats which may be related to increased nutrient-stimulated secretion of GLP-1(7-36) and PYY and improvements of insulin sensitivity, beta-cell function, and lipid metabolism. Topics: Adipocytes; Adiponectin; Animals; Diabetes Mellitus, Type 2; Gastric Bypass; Glucagon-Like Peptide 1; Glucose; Ileum; Insulin; Lipid Metabolism; Male; Peptide YY; Rats; Weight Loss | 2010 |
Liraglutide.
In January 2010, liraglutide (Victoza; Novo Nordisk)--an injectable glucagon-like peptide 1 receptor agonist--was approved by the US FDA to improve glycaemic control in adults with type 2 diabetes mellitus. Topics: Adult; Diabetes Mellitus, Type 2; Drug Approval; Glucagon-Like Peptide 1; Humans; Hypoglycemic Agents; Liraglutide; Randomized Controlled Trials as Topic; United States; United States Food and Drug Administration | 2010 |
Liraglutide (Victoza) for type 2 diabetes.
Liraglutide (Victoza-Novo Nordisk), a glucagon-like peptide-1 (GLP-1) receptor agonist given by subcutaneous injection, has been approved by the FDA for treatment of patients with type 2 diabetes. It can be used alone or in addition to oral antidiabetic drugs such as metformin (Glucophage, and others) or glimepiride (Amaryl, and others). Liraglutide is not recommended for first-line therapy and is not approved for use with insulin. Topics: Animals; Clinical Trials as Topic; Diabetes Mellitus, Type 2; Drug Interactions; Glucagon-Like Peptide 1; Glucagon-Like Peptide-1 Receptor; Humans; Hypoglycemic Agents; Liraglutide; Receptors, Glucagon | 2010 |
New therapeutic options: management strategies to optimize glycemic control.
Management of type 2 diabetes mellitus (T2DM) can be challenging. Patients frequently present with poor glycemic control despite therapy. Other patients may be nonadherent or resistant to continuing their treatment when confronted with undesirable adverse effects, such as weight gain, that are associated with many conventional therapies. Incretin-based therapies developed to treat patients with T2DM, including oral dipeptidyl peptidase-4 inhibitor agents or glucagon-like peptide-1 agonists, offer the potential of sustained glycemic control for many patients without the adverse events associated with other classes of antihyperglycemic medications. Available safety data from clinical trials indicate that incretin-based therapies have weight-neutral or weight-reducing effects, with no apparent adverse impact on other important safety parameters, such as cardiovascular disease. The integration of these therapies into treatment algorithms, as highlighted in three case presentations, will increase treatment options for patients with T2DM. Topics: Aged; Blood Glucose; Cardiovascular Diseases; Diabetes Mellitus, Type 2; Dipeptidyl-Peptidase IV Inhibitors; Exenatide; Female; Glucagon-Like Peptide 1; Glycated Hemoglobin; Humans; Hypoglycemic Agents; Incretins; Life Style; Male; Metformin; Middle Aged; Peptides; Pyrazines; Risk Factors; Sitagliptin Phosphate; Triazoles; Venoms | 2010 |
Effect of physical training on insulin secretion and action in skeletal muscle and adipose tissue of first-degree relatives of type 2 diabetic patients.
Physical training affects insulin secretion and action, but there is a paucity of data on the direct effects in skeletal muscle and adipose tissue and on the effect of training in first-degree relatives (FDR) of patients with type 2 diabetes. We studied insulin action at the whole body level and peripherally in skeletal muscle and adipose tissue as well as insulin-secretory capacity in seven FDR and eight control (CON) subjects before and after 12 wk of endurance training. Training improved physical fitness. Insulin-mediated glucose uptake (GU) increased (whole body and leg; P < 0.05) after training in CON but not in FDR, whereas glucose-mediated GU increased (P < 0.05) in both groups. Adipose tissue GU was not affected by training, but it was higher (abdominal, P < 0.05; femoral, P = 0.09) in FDR compared with CON. Training increased skeletal muscle lipolysis (P < 0.05), and it was markedly higher (P < 0.05) in subcutaneous abdominal than in femoral adipose tissue and quadriceps muscle with no difference between FDR and CON. Glucose-stimulated insulin secretion was lower in FDR compared with CON, but no effect of training was seen. Glucagon-like peptide-1 stimulated insulin secretion five- to sevenfold. We conclude that insulin-secretory capacity is lower in FDR than in CON and that there is dissociation between training-induced changes in insulin secretion and insulin-mediated GU. Maximal GU rates are similar between groups and increases with physical training. Topics: Adipose Tissue; Adult; Blood Glucose; Body Composition; C-Peptide; Diabetes Mellitus, Type 2; Exercise; Fatty Acids, Nonesterified; Genetic Predisposition to Disease; Glucagon-Like Peptide 1; Glucose Clamp Technique; Humans; Insulin; Insulin Secretion; Lactic Acid; Male; Muscle, Skeletal; Oxygen Consumption | 2010 |
Polycyclic aromatic hydrocarbons potentiate high-fat diet effects on intestinal inflammation.
We demonstrate that intestinal inflammation caused by high-fat diet is increased by the environmental contaminant benzo[a]pyrene. Our in vivo results indicate that a high-fat diet (HFD) induces a pre-diabetic state in mice compared with animals fed normal chow. HFD increased IL-1betamRNA concentration in the jejunum, colon, and liver, and TNFalpha was increased in the colon and strongly increased in the liver. HFD also increased the expression of other genes related to type 2 diabetes, such as the uncoupling protein UCP2, throughout the bowel and liver, but not in the colon. The treatment of HFD with BaP enhanced the expression of IL-1beta in the liver and TNFalpha throughout the bowel and in the liver. Adding BaP to the diet also caused a significant decrease in the expression of the incretin glucagon-like peptide 1, which plays an important role in insulin secretion. Our results suggest that intestinal inflammation may be involved in the onset of type 2 diabetes and that chronic exposure to environmental polycyclic aromatic hydrocarbons can increase the risk of type 2 diabetes by inducing pro-inflammatory cytokine production. Topics: Animals; Benzo(a)pyrene; Diabetes Mellitus, Type 2; Dietary Fats; Enteritis; Glucagon-Like Peptide 1; Insulin; Interleukin-10; Interleukin-1beta; Ion Channels; Male; Mice; Mice, Inbred C57BL; Mitochondrial Proteins; Tumor Necrosis Factor-alpha; Uncoupling Protein 2; Weight Gain | 2010 |
Chronic administration of DSP-7238, a novel, potent, specific and substrate-selective DPP IV inhibitor, improves glycaemic control and beta-cell damage in diabetic mice.
The purpose of this study is to assess the in vitro enzyme inhibition profile of DSP-7238, a novel non-cyanopyrrolidine dipeptidyl peptidase (DPP) IV inhibitor and to evaluate the acute and chronic effects of this compound on glucose metabolism in two different mouse models of type 2 diabetes.. The in vitro enzyme inhibition profile of DSP-7238 was assessed using plasma and recombinant enzymes including DPP IV, DPP II, DPP8, DPP9 and fibroblast activation protein alpha (FAPalpha) with fluorogenic substrates. The inhibition type was evaluated based on the Lineweaver-Burk plot. Substrate selectivity of DSP-7238 and comparator DPP IV inhibitors (vildagliptin, sitagliptin, saxagliptin and linagliptin) was evaluated by mass spectrometry based on the changes in molecular weight of peptide substrates caused by release of N-terminal dipeptides. In the in vivo experiments, high-fat diet-induced obese (DIO) mice were subjected to oral glucose tolerance test (OGTT) following a single oral administration of DSP-7238. To assess the chronic effects of DSP-7238 on glycaemic control and pancreatic beta-cell damage, DSP-7238 was administered for 11 weeks to mice made diabetic by a combination of high-fat diet (HFD) and a low-dose of streptozotocin (STZ). After the dosing period, HbA1c was measured and pancreatic damage was evaluated by biological and histological analyses.. DSP-7238 and sitagliptin both competitively inhibited recombinant human DPP IV (rhDPP IV) with K(i) values of 0.60 and 2.1 nM respectively. Neither vildagliptin nor saxagliptin exhibited competitive inhibition of rhDPP IV. DSP-7238 did not inhibit DPP IV-related enzymes including DPP8, DPP9, DPP II and FAPalpha, whereas vildagliptin and saxagliptin showed inhibition of DPP8 and DPP9. Inhibition of glucagon-like peptide-1 (GLP-1) degradation by DSP-7238 was apparently more potent than its inhibition of chemokine (C-X-C motif) ligand 10 (IP-10) or chemokine (C-X-C motif) ligand 12 (SDF-1alpha) degradation. In contrast, vildagliptin and saxagliptin showed similar degree of inhibition of degradation for all the substrates tested. Compared to treatment with the vehicle, single oral administration of DSP-7238 dose-dependently decreased plasma DPP IV activity and improved glucose tolerance in DIO mice. In addition, DSP-7238 significantly decreased HbA1c and ameliorated pancreatic damage following 11 weeks of chronic treatment in HFD/STZ mice.. We have shown in this study that DSP-7238 is a potent DPP IV inhibitor that has high specificity for DPP IV and substrate selectivity against GLP-1. We have also found that chronic treatment with DSP-7238 improves glycaemic control and ameliorates beta-cell damage in a mouse model with impaired insulin sensitivity and secretion. These findings indicate that DSP-7238 may be a new therapeutic agent for the treatment of type 2 diabetes. Topics: Animals; Blood Glucose; Diabetes Mellitus, Experimental; Diabetes Mellitus, Type 2; Dipeptidyl-Peptidase IV Inhibitors; Dose-Response Relationship, Drug; Glucagon-Like Peptide 1; Glucose Tolerance Test; Immunohistochemistry; Insulin-Secreting Cells; Male; Mice | 2010 |
Addition of incretin therapy to metformin in type 2 diabetes.
Topics: Diabetes Mellitus, Type 2; Drug Therapy, Combination; Glucagon-Like Peptide 1; Humans; Hypoglycemic Agents; Incretins; Metformin | 2010 |
Alas! Ileal interposition surgery for diabetes prevention?
Topics: Animals; Diabetes Mellitus, Type 2; Glucagon-Like Peptide 1; Glucose; Humans; Ileum; Lipid Metabolism; Metabolic Syndrome; Rats | 2010 |
[New hypoglycemic agents in type 2 diabetes].
New treatments of type 2 diabetes have been developed, especially with the use of the properties of incretins, gastrointestinal hormones involved in glucose homeostasis. GLP-1 is responsible for most incretin effect with a rate that increases within minutes after meal intake, suggesting that its secretion is initially triggered by the combination of endocrine and nervous signals. The effects of GLP-1 on insulin secretion and glucagon are observed only at high glucose levels (glucose-dependent effects). In the type 2 diabetes, the incretin effect is altered due to reduced plasma concentrations of GLP-1, but its activity is intact. There are two innovative therapeutic approaches aimed to restore the incretin effect in patients with type 2 diabetes: the agonists of GLP-1 receptors administered subcutaneously that replace the deficiency of GLP-1; and the DPP-4 inhibitors that can prolong the life of endogenous GLP-1 by reducing activity of the enzyme DPP-4 that degrades GLP-1, molecules offering the advantage of oral administration. Their effectiveness on the glucose metabolism is around 0.5 to 1.1% and 0.8 to 1.5% in reduction in HbAlc for DPP-4 inhibitors and agonists of GLP-1 receptors, respectively. Moreover these latter have extra pancreatic effects, particularly by reducing gastric emptying and control of satiety, resulting in a weight loss of 1.6 to 3.8 kg. Their tolerance is generally good especially for the DPP-4 inhibitors, whereas agonists in GLP-1 receptor often cause nausea or vomiting at the initiation of the therapy. However their effectiveness and long-term safety need to be evaluated. Topics: Adamantane; Diabetes Mellitus, Type 2; Dipeptides; Exenatide; Glucagon-Like Peptide 1; Humans; Hypoglycemic Agents; Liraglutide; Nitriles; Peptides; Pyrazines; Pyrrolidines; Sitagliptin Phosphate; Triazoles; Venoms; Vildagliptin | 2010 |
[Elevated serum dipeptidyl peptidase-4 activity in type 1 diabetes mellitus: a direct comparison].
Dipeptidyl peptidase-4 (DPP-4) has an important role in the carbohydrate metabolism with the degradation of incretin hormones.. We assessed the serum DPP-4 activity both in fasting and postprandial condition in patients with type 1-, type 2 diabetes and healthy controls.. Serum DPP-4 activities were determined at fasting sate and at 60 and 180 minutes after test meal. DPP-4 activity was measured by microplate-based kinetic assay in 41 type 1-, and in 87 type 2 diabetic patients and in 25 healthy volunteers.. Serum DPP-4 activities were found significantly higher both in fasting and postprandial state in patients with type 1 diabetes than in type 2 and control subjects. No change in the enzyme activities was found after test meal. Correlation was neither detected between the fasting plasma glucose nor between the HbA(1C) and the DPP-4 values in any of the groups studied.. RESULTS suggest that it is not the hyperglycemia, rather the type of diabetes which determinates the serum DPP-4 enzymatic activity. The exact background of this phenomenon is not yet clear, however, increased serum DPP-4 enzyme activity in type 1 diabetes mellitus may refer to pancreatic autoimmune process, concomitant autoimmune diseases, hormonal feed back mechanism, or even target organ damage. Topics: Adult; Aged; Biomarkers; Blood Glucose; Diabetes Mellitus, Type 1; Diabetes Mellitus, Type 2; Dipeptidyl Peptidase 4; Female; Glucagon-Like Peptide 1; Glycated Hemoglobin; Humans; Male; Middle Aged | 2010 |
Impact of exogenous hyperglucagonemia on postprandial concentrations of gastric inhibitory polypeptide and glucagon-like peptide-1 in humans.
Postprandial secretion of glucagon-like peptide 1 (GLP-1) has been found diminished in some patients with type 2 diabetes mellitus (T2DM) and high glucagon concentrations. We examined the effects of exogenous glucagon on the release of incretin hormones.. Ten patients with T2DM and 10 healthy controls were examined with a meal test during the iv administration of glucagon 0.65 ng/kg.min and placebo.. GLP-1 plasma concentration increased after meal ingestion in both groups (P<0.0001), but postprandial GLP-1 plasma levels were not affected by glucagon administration. However, immediately after cessation of the glucagon infusion, GLP-1 levels increased by about 2-fold to levels of 51.8+/-14.6 pmol/liter in the T2DM patients and 58.9+/-20.0 pmol/liter in controls (P<0.05). The time courses of glucose-dependent insulinotropic peptide glucose-dependent insulinotropic peptide and GLP-1 concentrations were not different between T2DM patients and controls during the placebo experiments (P=0.33 and P=0.13, respectively). Glucose concentrations were increased by glucagon administration in controls (P<0.05, respectively), but insulin and C-peptide levels were not affected. Gastric emptying was slightly delayed by glucagon administration in controls (P<0.05) but not in T2DM patients (P=0.77).. Exogenous glucagon does not directly inhibit incretin secretion. However, a decline in circulating glucagon levels may exert a permissive effect on GLP-1 release. This might contribute to the reduction in GLP-1 concentrations found in some patients with T2DM. Topics: Aged; Analysis of Variance; Blood Glucose; C-Peptide; Diabetes Mellitus, Type 2; Female; Gastric Inhibitory Polypeptide; Glucagon; Glucagon-Like Peptide 1; Humans; Incretins; Insulin; Male; Middle Aged; Postprandial Period | 2010 |
Comment on: Villareal et al. (2009) TCF7L2 variant rs7903146 affects the risk of type 2 diabetes by modulating incretin action. Diabetes;59:479-485.
Topics: Body Mass Index; Diabetes Mellitus, Type 2; Genetic Variation; Glucagon-Like Peptide 1; Glucagon-Like Peptides; Humans; Incretins; Risk Factors; TCF Transcription Factors; Transcription Factor 7-Like 2 Protein | 2010 |
Preventive treatment with acarbose in diabetic reactive hypoglycemia.
Topics: Acarbose; Aged, 80 and over; Diabetes Mellitus, Type 2; Glucagon-Like Peptide 1; Humans; Hypoglycemia; Hypoglycemic Agents | 2010 |
Choosing among the incretin agents and why it matters.
Topics: Adamantane; Blood Pressure; Diabetes Mellitus, Type 2; Dipeptides; Dipeptidyl-Peptidase IV Inhibitors; Exenatide; Glucagon-Like Peptide 1; Humans; Hypoglycemic Agents; Incretins; Insulin-Secreting Cells; Lipids; Liraglutide; Male; Middle Aged; Peptides; Pyrazines; Sitagliptin Phosphate; Triazoles; Venoms; Weight Loss | 2010 |
Relationship between GLP-1 levels and dipeptidyl peptidase-4 activity in different glucose tolerance conditions.
The reduced levels of glucagon-like peptide 1 (GLP-1) after an oral glucose load in Type 2 diabetic patients could be dependent either on a reduced synthesis or an increased degradation; but GLP-1 and dipeptidyl peptidase IV (DPP-IV) levels during an oral glucose tolerance test (OGTT) have not been studied together. The aim of the present study was to investigate GLP-1 and DPP-IV levels during an OGTT in patients with different degrees of glucose tolerance.. Fifty six subjects (34 female, 22 male) matched for sex, age, body mass index (BMI) and waist circumference underwent a 75 g oral glucose tolerance test. Twenty-eight had normal glucose tolerance, 15 had impaired glucose tolerance and 13 had Type 2 diabetes mellitus. GLP-1 assay was performed with an ELISA kit, and DPP-IV assay using a colorimetric method.. At 30 min GLP-1 levels were significantly lower in subjects with impaired glucose tolerance and type 2 diabetes mellitus compared to those with normal glucose tolerance. The area under the GLP-1 curve was significantly different among the three groups; there was a significant decrease between subjects with normal and impaired glucose tolerance(P = 0.004) and between those with normal glucose tolerance and type 2 diabetes mellitus. (P < 0.001), while the area under the curve for DPP-IV showed no significant difference between the groups.. These results suggest that an increase of GLP-1 degradation does not play a role in the early stages of diabetes mellitus. Topics: Aged; Area Under Curve; Body Mass Index; Diabetes Mellitus, Type 2; Dipeptidyl Peptidase 4; Fasting; Female; Glucagon-Like Peptide 1; Glucose Tolerance Test; Humans; Male; Middle Aged; Waist Circumference | 2010 |
[Diabetes therapy--novel drugs to come (DPP-4 inhibitors, GLP-1 agonists, SGLT-2 inhibitors)].
Topics: Clinical Trials as Topic; Diabetes Mellitus, Type 2; Dipeptidyl Peptidase 4; Dipeptidyl-Peptidase IV Inhibitors; Drug Therapy, Combination; Drugs, Investigational; Germany; Glucagon-Like Peptide 1; Humans; Hypoglycemic Agents; Sodium-Glucose Transporter 2; Sodium-Glucose Transporter 2 Inhibitors | 2010 |
Identification of glycosylated exendin-4 analogue with prolonged blood glucose-lowering activity through glycosylation scanning substitution.
Exendin-4, a glucagon-like peptide 1 receptor agonist, is a potent therapeutic xenopeptide hormone for the treatment of type 2 diabetes. In order to further improve in vivo activity, we examined the introduction of sialyl N-acetyllactosamine (sialyl LacNAc) to exendin-4. The glycosylated analogue having sialyl LacNAc at position 28 was found to have improved in vivo activity with prolonged glucose-lowering activity. Topics: Amino Acid Sequence; Animals; Blood Glucose; Diabetes Mellitus, Type 2; Disease Models, Animal; Exenatide; Glucagon-Like Peptide 1; Glycosylation; Hypoglycemic Agents; Mice; Molecular Sequence Data; Peptides; Venoms | 2010 |
Taking aim at islet hormones with GLP-1: is insulin or glucagon the better target?
Topics: Diabetes Mellitus, Type 2; Glucagon; Glucagon-Like Peptide 1; Humans; Insulin | 2010 |
Taspoglutide, a novel human once-weekly analogue of glucagon-like peptide-1, improves glucose homeostasis and body weight in the Zucker diabetic fatty rat.
Glucagon-like peptide-1 (GLP-1) receptor agonists are a novel class of pharmacotherapy for type 2 diabetes. We investigated the effects of a novel, long-acting human GLP-1 analogue, taspoglutide, in the Zucker diabetic fatty (ZDF) rat, an animal model of type 2 diabetes.. Blood glucose and plasma levels of insulin, peptide YY (PYY), glucose-dependent insulinotropic polypeptide (GIP) and triglycerides were measured during oral glucose tolerance tests (oGTT) conducted in ZDF rats treated acutely or chronically with a single long-acting dose of taspoglutide. Pioglitazone was used as a positive control in the chronic study. Postprandial glucose, body weight, glycaemic control and insulin sensitivity were assessed over 21 days in chronically treated animals.. Acute treatment with taspoglutide reduced glucose excursion and increased insulin response during oGTT. In chronically treated rats, glucose excursion and levels of GIP, PYY and triglycerides during oGTT on day 21 were significantly reduced. Postprandial glucose levels were significantly lower than vehicle controls by day 15. A significant reduction in body weight gain was noticed by day 8, and continued until the end of the study when body weight was approximately 7% lower in rats treated with taspoglutide compared to vehicle. Glycaemic control (increased levels of 1,5-anhydroglucitol) and insulin sensitivity (Matsuda index) were improved by taspoglutide treatment.. Taspoglutide showed typical effects of native GLP-1, with improvement in glucose tolerance, postprandial glucose, body weight, glycaemic control and insulin sensitivity. Topics: Animals; Blood Glucose; Body Weight; Diabetes Mellitus, Type 2; Glucagon-Like Peptide 1; Glucose Tolerance Test; Homeostasis; Hypoglycemic Agents; Peptides; Postprandial Period; Rats; Rats, Zucker | 2010 |
Synthesis and characterization of ester-based prodrugs of glucagon-like peptide 1.
Peptides represent a rich natural source of potential medicines with one notable pharmaceutical limitation being their relatively short duration of action. A particularly good example of this phenomenon is glucagon-like peptide 1 (GLP), a hormone of appreciable interest for the treatment of type II diabetes. In the native form, GLP demonstrates an extremely short half-life in plasma and a relatively narrow therapeutic index with gastrointestinal adverse pharmacology. We envisioned a prodrug of GLP as a means to extend the duration of action and broaden the therapeutic index of this peptide hormone. We designed, synthesized, and characterized ester-based prodrugs of GLP that differentially convert to the parent drug under physiological conditions driven by their inherent chemical instability. In a set of dipeptide extended GLP-analogs we explored the rate of diketopiperazine (DKP) and diketomorpholine (DMP) formation, and the release of the active peptide. The rate of cleavage was observed to be a function of the conformation of the dipeptide promoiety and the strength of the cyclization nucleophile. Through the careful selection of chemical functionality, a set of GLP ester prodrugs of variable half-lives has been identified. Topics: Diabetes Mellitus, Type 2; Diketopiperazines; Dipeptides; Glucagon-Like Peptide 1; Humans; Prodrugs | 2010 |
Longacting exenatide in diabetes: DURATION-3.
Topics: Blood Glucose; Diabetes Mellitus, Type 2; Drug Administration Schedule; Exenatide; Glucagon-Like Peptide 1; Humans; Hypoglycemic Agents; Insulin; Insulin Glargine; Insulin, Long-Acting; Peptides; Venoms | 2010 |
Hepatic electrical stimulation reduces blood glucose in diabetic rats.
The aim of this study was to investigate the feasibility and mechanisms of controlling blood glucose using hepatic electrical stimulation (HES).. The study was performed in regular Sprague-Dawley (SD) rats, streptozotocin-induced type 1 diabetic rats and Zucker diabetic fatty (ZDF) rats chronically implanted with one pair of stimulation electrodes on two lobes of the liver tissues.. (i) Hepatic electrical stimulation was effective in reducing blood glucose by 27%-31% at time points 60, 75 and 90 min after oral glucose in normal rats; (ii) HES reduced blood glucose in both fasting and fed states in both type 1 and type 2 diabetic rats; (iii) Chronic HES decreased the blood glucose level, and, delayed gastric empty and increased plasma glucagon-like peptide-1 (GLP-1) level; and (iv) No adverse events were noted in any rats during HES. Histopathological analyses and liver function tests revealed no electrode dislodgement, tissue damages or liver enzyme changes with HES.. Hepatic electrical stimulation is capable of reducing both fasting and fed blood glucose in normal, and type 1 and type 2 diabetic rats and the effect may be partially mediated via an increase in GLP-1 release. Topics: Animals; Blood Glucose; Diabetes Mellitus; Diabetes Mellitus, Experimental; Diabetes Mellitus, Type 1; Diabetes Mellitus, Type 2; Electric Stimulation; Electrodes, Implanted; Fasting; Gastric Emptying; Gastric Inhibitory Polypeptide; Gastrointestinal Transit; Glucagon-Like Peptide 1; Glucose Tolerance Test; Liver; Rats; Rats, Sprague-Dawley; Rats, Zucker | 2010 |
Incretin secretion and serum DPP-IV activity in Korean patients with type 2 diabetes.
We evaluated incretin secretion and dipeptidyl peptidase (DPP)-IV activity in Korean type 2 diabetic patients compared with non-diabetic subjects. Type 2 diabetic patients showed intact GLP-1 and total GIP levels similar to those in non-diabetic subjects. Serum DPP-IV activity was significantly higher in type 2 diabetic patients (p=0.022). Topics: Asian People; Diabetes Mellitus, Type 2; Dipeptidyl Peptidase 4; Female; Glucagon-Like Peptide 1; Humans; Incretins; Male; Middle Aged | 2010 |
Chronic administration of the glucagon-like peptide-1 analog, liraglutide, delays the onset of diabetes and lowers triglycerides in UCD-T2DM rats.
The efficacy of liraglutide, a human glucagon-like peptide-1 (GLP-1) analog, to prevent or delay diabetes in UCD-T2DM rats, a model of polygenic obese type 2 diabetes, was investigated.. At 2 months of age, male rats were divided into three groups: control, food-restricted, and liraglutide. Animals received liraglutide (0.2 mg/kg s.c.) or vehicle injections twice daily. Restricted rats were food restricted to equalize body weights to liraglutide-treated rats. Half of the animals were followed until diabetes onset, whereas the other half of the animals were killed at 6.5 months of age for tissue collection.. Before diabetes onset energy intake, body weight, adiposity, and liver triglyceride content were higher in control animals compared with restricted and liraglutide-treated rats. Energy-restricted animals had lower food intake than liraglutide-treated animals to maintain the same body weights, suggesting that liraglutide increases energy expenditure. Liraglutide treatment delayed diabetes onset by 4.1 ± 0.8 months compared with control (P < 0.0001) and by 1.3 ± 0.8 months compared with restricted animals (P < 0.05). Up to 6 months of age, energy restriction and liraglutide treatment lowered fasting plasma glucose and A1C concentrations compared with control animals. In contrast, liraglutide-treated animals exhibited lower fasting plasma insulin, glucagon, and triglycerides compared with both control and restricted animals. Furthermore, energy-restricted and liraglutide-treated animals exhibited more normal islet morphology.. Liraglutide treatment delays the development of diabetes in UCD-T2DM rats by reducing energy intake and body weight, and by improving insulin sensitivity, improving lipid profiles, and maintaining islet morphology. Topics: Age of Onset; Animals; Blood Glucose; Body Weight; Diabetes Mellitus, Experimental; Diabetes Mellitus, Type 2; Diuresis; Energy Metabolism; Glucagon-Like Peptide 1; Glycated Hemoglobin; Humans; Hyperglycemia; Liraglutide; Male; Pancreas; Rats; Time Factors; Triglycerides | 2010 |
Sitagliptin-associated drug allergy: review of spontaneous adverse event reports.
Topics: Adult; Adverse Drug Reaction Reporting Systems; Aged; Aged, 80 and over; Diabetes Mellitus, Type 2; Dipeptidyl-Peptidase IV Inhibitors; Drug Hypersensitivity; Female; Glucagon-Like Peptide 1; Humans; Incidence; Male; Middle Aged; Pyrazines; Retrospective Studies; Sitagliptin Phosphate; Triazoles; United States | 2010 |
[Therapy of obesity with liraglutide. NN8022-1807 study].
Topics: Administration, Oral; Adult; Anti-Obesity Agents; Combined Modality Therapy; Diabetes Mellitus, Type 1; Diabetes Mellitus, Type 2; Diet, Reducing; Dose-Response Relationship, Drug; Double-Blind Method; Female; Glucagon-Like Peptide 1; Humans; Injections, Subcutaneous; Lactones; Liraglutide; Male; Middle Aged; Multicenter Studies as Topic; Obesity; Orlistat; Quality of Life; Randomized Controlled Trials as Topic; Surveys and Questionnaires; Weight Loss | 2010 |
The increasing epidemiology of diabetes and review of current treatment algorithms.
The prevalence of diabetes is expected to grow both nationally and globally. Therefore, increased effort to reduce the incidence of this disease is warranted. Physicians must be able to identify individuals who are at risk for diabetes and implement strategies to prevent diabetes onset. Because early diagnosis is critical for reducing the complications of type 2 diabetes mellitus (T2DM), physicians must actively screen for and diagnose diabetes in their practice. Physicians must also be knowledgeable of the recommendations for glycemic goals and apply the treatment algorithms put forth by the American Diabetes Association/European Association for the Study of Diabetes and the American Association of Clinical Endocrinologists/American College of Endocrinology in the management of patients afflicted with T2DM. Topics: Algorithms; Biological Assay; Diabetes Mellitus, Type 2; Disease Management; Glucagon-Like Peptide 1; Glycated Hemoglobin; Glycemic Index; Humans; Hypoglycemic Agents; Metformin; Practice Guidelines as Topic; Prevalence; Risk Factors; United States | 2010 |
Exendin-4 protects pancreatic beta cells from human islet amyloid polypeptide-induced cell damage: potential involvement of AKT and mitochondria biogenesis.
Glucagon-like peptide-1 (GLP-1) stimulates beta-cell proliferation and enhances beta-cell survival, whereas oligomerization of human islet amyloid polypeptide (hIAPP) may induce beta-cell apoptosis and reduce beta-cell mass. Type 2 diabetes is associated with increased expression of IAPP. As GLP-1-based therapy is currently developed as a novel antidiabetic therapy, we examined the potential protective action of the GLP-1 receptor agonist exendin-4 on hIAPP-induced beta-cell apoptosis.. The study was performed in clonal insulinoma (INS-1E) cells. Both method of transcriptional and translational and sulphorhodamine B (SRB) assays were used to evaluate cell viability and cell mass. Western blot analysis was applied to detect protein expression. Transfection of constitutively active protein kinase B (PKB/AKT) was performed to examine the role of AKT. Mitochondrial biogenesis was quantified by mitogreen staining and RT-PCR.. First, we confirmed that hIAPP induced cell apoptosis and growth inhibition in INS-1E cells. These effects were partially protected by exendin-4 in association with partial recovery of the hIAPP-mediated AKT inhibition. Furthermore, AKT constitutive activation attenuated hIAPP-induced apoptosis, whereas PI3K/AKT inhibition abrogated exendin-4-mediated effects. These findings suggest that the antiapoptotic and proliferative effects of exendin-4 in hIAPP-treated INS-1E cells were partially mediated through AKT pathway. Moreover, hIAPP induced FOXO1 but inhibited pdx-1 nucleus translocation. These effects were restored by exendin-4. Finally, mitogreen staining and RT-PCR revealed enhanced mitochondrial biogenesis by exendin-4 treatment.. Collectively, these results suggest that GLP-1 receptor agonist protects beta cells from hIAPP-induced cell death partially through the activation of AKT pathway and improved mitochondrial function. Topics: Apoptosis; Cytoprotection; Diabetes Mellitus, Type 2; Exenatide; Glucagon-Like Peptide 1; Glucagon-Like Peptide-1 Receptor; Humans; Hypoglycemic Agents; Insulin-Secreting Cells; Islet Amyloid Polypeptide; Mitochondria; Peptides; Receptors, Glucagon; Signal Transduction; Venoms | 2010 |
[Mechanism of laparoscopic adjustable gastric banding in the treatment of obesity with type 2 diabetes mellitus].
To explore the mechanism of laparoscopic adjustable gastric banding (LAGB) in the treatment of obese patients with type 2 diabetes mellitus (T2DM).. A total of 20 patients with obesity and T2DM were treated with LAGB. During the postoperative 1, 3, 6, 9, 12 months, the body weight changes were monitored and body mass indices (BMI) were calculated. The serum levels of leptin, GLP-1, and ghrelin were examined preoperatively and 1, 3, 6, 9, 12 months after LAGB using enzyme-linked-immunosorbent assay (ELISA). At the same time, the fasting serum insulin (FINS), C-peptide, glycated hemoglobin (HbA1c) levels were examined by electrochemiluminescence and the level of fasting blood glucose (FBG) was tested with oxidase test.. At postoperatively 12 months, all the 20 patients lost weight. The mean body weight decreased from (108 + or - 18) kg to (71 + or - 16) kg (P<0.05) and BMI decreased from 38 + or - 5 to 29 + or - 6 (P<0.05). The HOMA-IR decreased from (12.8 + or - 7.4) to (3.4 + or - 2.0) (P<0.01). The serum ghrelin level increased from (7.8 + or - 1.9) microg/L to (11.6 + or - 2.6) microg/L (P<0.01). The serum leptin level declined from (24.9 + or - 13.7) microg/L to(12.9 + or - 5.1) microg/L (P<0.01). The serum GLP-1 level increased from (0.58 + or - 0.12) microg/L to(0.80 + or - 0.06) microg/L (P<0.01). After LAGB, there were positive correlations between serum leptin level and FBG, FINS, HbA1c,and C-peptide level. Serum ghrelin and GLP-1 were negatively correlated with FBG, FINS, HbA1c,C-peptide.. LAGB is effective in treatment of obesity patients with T2DM. The mechanism may be associated with the increase of serum GLP-1 and ghrelin and the decrease of serum leptin and insulin resistance. Topics: Adult; Blood Glucose; Body Mass Index; Diabetes Mellitus, Type 2; Female; Gastroplasty; Ghrelin; Glucagon-Like Peptide 1; Glycated Hemoglobin; Humans; Laparoscopy; Leptin; Male; Middle Aged; Obesity; Young Adult | 2010 |
Non-peptidic glucose-like peptide-1 receptor agonists: aftermath of a serendipitous discovery.
Glucagon-like peptide-1 (GLP-1) receptor is an ideal target in the development of incretin-based therapies for diabetes and obesity. Two approaches have been adopted: GLP-1 receptor agonists that mimic the effects of native GLP-1 and dipeptidyl peptidase-4 inhibitors that increase endogenous GLP-1 levels. During the past two decades, search for orally active, non-peptidic GLP-1 receptor agonists has been the focal point of research and development activities in many multinational pharmaceutical companies. Such efforts have not resulted in any success thus far. Serendipitous discovery of substituted cyclobutanes represented by Boc5 as a new class of GLP-1 receptor agonists led us to believe that a small molecule approach to class B G-protein coupled receptor agonism is no longer a fantasy but a reality. However, major obstacles still pose great challenges, and the reasons of which are discussed in this perspectives. Topics: Animals; Diabetes Mellitus, Type 2; Glucagon-Like Peptide 1; Glucagon-Like Peptide-1 Receptor; Humans; Receptors, Glucagon; Small Molecule Libraries | 2010 |
Weight loss and incretin responsiveness improve glucose control independently after gastric bypass surgery.
The aim of the present study was to determine the mechanisms underlying Type 2 diabetes remission after gastric bypass (GBP) surgery by characterizing the short- and long-term changes in hormonal determinants of blood glucose.. Eleven morbidly obese women with diabetes were studied before and 1, 6, and 12 months after GBP; eight non-diabetic morbidly obese women were used as controls. The incretin effect was measured as the difference in insulin levels in response to oral glucose and to an isoglycemic intravenous challenge. Outcome measures were glucose, insulin, C-peptide, proinsulin, amylin, glucagon, glucose-dependent insulinotropic polypeptide (GIP), glucagon-like peptide-1 (GLP-1) levels and the incretin effect on insulin secretion.. The decrease in fasting glucose (r = 0.724) and insulin (r = 0.576) was associated with weight loss up to 12 months after GBP. In contrast, the blunted incretin effect (calculated at 22%) that improved at 1 month remained unchanged with further weight loss at 6 (52%) and 12 (52%) months. The blunted incretin (GLP-1 and GIP) levels, early phase insulin secretion, and other parameters of β-cell function (amylin, proinsulin/insulin) followed the same pattern, with rapid improvement at 1 month that remained unchanged at 1 year.. The data suggest that weight loss and incretins may contribute independently to improved glucose levels in the first year after GBP surgery. Topics: Adiponectin; Adult; Blood Glucose; Diabetes Mellitus, Type 2; Fasting; Female; Gastric Bypass; Glucagon; Glucagon-Like Peptide 1; Glucose Tolerance Test; Humans; Incretins; Insulin; Insulin Secretion; Leptin; Middle Aged; Obesity, Morbid; Postoperative Period; Stomach; Weight Loss | 2010 |
Q: Do incretin drugs for type 2 diabetes increase the risk of acute pancreatitis?
Topics: Acute Disease; Adult; Diabetes Mellitus, Type 2; Dipeptidyl-Peptidase IV Inhibitors; Female; Glucagon-Like Peptide 1; Humans; Hypoglycemic Agents; Incretins; Male; Pancreatitis; Risk; Young Adult | 2010 |
A high-fat diet inhibits the progression of diabetes mellitus in type 2 diabetic rats.
It is well known that rats and mice, when fed a high-fat diet, develop obesity associated with abnormal glycolipid metabolism. In this study, we investigated the effects of a high-fat diet on a diabetic rat model, Spontaneously Diabetic Torii (SDT), which develops diabetes due to decreased insulin production and secretion with age. We hypothesized that a high-fat diet would accelerate the induction of diabetes in this model. The SDT rats were divided into 2 groups, which were fed a high-fat diet or standard diet for 16 weeks. The group fed a high-fat diet developed obesity, hyperinsulinemia, and hyperlipidemia until 16 weeks of age. Before 16 weeks of age, hyperglycemia accompanied by hypoinsulinemia developed in the group on a standard diet, but serum glucose levels were comparable in both groups. After 16 weeks of age, the group on a standard diet showed an increase in serum glucose levels and a decrease in serum insulin levels. Unexpectedly, in the group on the high-fat diet, we observed a suppressed of the progression of hyperglycemia/hypoinsulinemia. Histopathological observation revealed more pancreatic beta cells in the group on the high-fat diet. This study suggests that feeding SDT rats a high-fat diet induces obesity, hyperinsulinemia, and hyperlipidemia, but not hyperglycemia, until 16 weeks of age. Thereafter, age-dependent progress of hyperglycemia and hypoinsulinemia was delayed by a high-fat diet. The hyperfunction of pancreatic beta cells induced by a high-fat diet before the onset of hyperglycemia appears to suppress development of hyperglycemia/hypoinsulinemia. Topics: Adipose Tissue; Animals; Blood Glucose; Body Weight; Diabetes Mellitus, Type 2; Diet; Dietary Fats; Energy Intake; Glucagon-Like Peptide 1; Glucose Tolerance Test; Insulin; Male; Pancreas; Proteinuria; Rats | 2010 |
Synthesis and SAR of 2-aryl-3-aminomethylquinolines as agonists of the bile acid receptor TGR5.
Optimization of a screening hit from uHTS led to the discovery of TGR5 agonist 32, which was shown to have activity in a rodent model for diabetes. Topics: Animals; Diabetes Mellitus, Type 2; Glucagon-Like Peptide 1; Hydroxyquinolines; Mice; Quinolines; Receptors, G-Protein-Coupled; Structure-Activity Relationship; Thiophenes | 2010 |
A novel GLP-1 analog, BPI3006, with potent DPP IV resistance and good glucoregulatory effect.
Glucagon-like peptide-1 (GLP-1) is an incretin hormone that decreases postprandial glycemic excursions by enhancing insulin secretion but with short half-life due to rapid inactivation by enzymatic N-terminal truncation. Therefore, efforts are being made to improve the stability of GLP-1 via modifying its structure or inhibiting dipeptidyl-peptidase IV (DPP IV), which is responsible for its degradation. Here we report a novel GLP-1 analog BPI3006 with -NHCO- of Ala(8) replaced by -CH(CF(3))NH- and features of its metabolic stability, GLP-1 receptor trans-activation and in vivo biological activity. BPI3006 is highly resistant to DPP IV-mediated degradation with 91.1% of parental peptide left after 24h exposure to the enzyme. BPI3006 also effectively activates its target gene promoter through GLP-1 receptor activation by measuring the transiently transfected reporter gene green fluorescence protein (GFP) expression in NIT-1 cells. Furthermore, BPI3006 could well restrain the glycemia variation in fasted normal ICR mice after a single administration followed by an oral glucose loading. In spontaneous type 2 diabetic KKA(y) mice, BPI3006 injected twice daily could significantly improve the oral glucose tolerance and hyperinsulinemia, as well as ameliorate the food and water consumption. In conclusion, BPI3006 has enhanced resistance to DPP IV leading to improved stability, and shows excellent in vivo biological activity. Thus it may be a new candidate for T2DM treatment and its novel modification may provide valuable guidance for the future development of long-acting GLP-1 analogs. Topics: Amino Acid Sequence; Animals; Diabetes Mellitus, Experimental; Diabetes Mellitus, Type 2; Dipeptidyl Peptidase 4; Glucagon-Like Peptide 1; Glucagon-Like Peptide-1 Receptor; Hypoglycemic Agents; Male; Mice; Mice, Inbred ICR; Molecular Sequence Data; Peptides; Receptors, Glucagon | 2010 |
Role of GLP-1 induced glucagon suppression in type 2 diabetes mellitus.
This project consisted of two parts: a biochemical part and clinical studies. The overall aim was to elucidate the defective regulation of glucagon secretion in type 2 diabetes (T2DM). The aim in the biochemical part was to develop a glucagon ELISA by using C- and N-terminal antibodies generated in the laboratory. Much effort was put into this attempt; however, we were unsuccessful and had to use an alternative method in our attempt to characterize the paradoxical diabetic glucagon response further. By using Sep-Pac and HPLC separation methods, plasma from patients with T2DM known to have a defective suppression of glucagon was analyzed using three antibodies and RIA. In this way the hyperglucagonaemia was found to consist mainly of authentic glucagon, rather than abnormally processed forms. The first clinical study included ten healthy controls matched to ten patients with T2DM. The aim was to investigate if GLP-1 induced glucagon inhibition was dose dependent and if suppression was equally potent in healthy controls and T2DM patients. Further, we investigated if the potency of the inhibition depended on the prevailing plasma glucose (PG) level. All participants were investigated with increasing doses of GLP-1 administered as iv-infusions and saline (control) during a glycaemic clamp at fasting plasma glucose (FPG) levels. Patients were investigated on a third occasion with GLP-1 infusions after an over-night normalisation of PG using adjustable insulin infusions. From these experiments we were able to conclude that GLP-1-induced glucagon inhibition is dose-dependent, but surprisingly GLP-1 suppressed the alpha cell equally potently in patients and controls - and the suppression was independent of PG level. Therefore we concluded that the paradoxical glucagon response to orally ingested glucose is not caused by decreased potency of GLP-1 with respect to glucagon suppression. It may be due to the decreased secretion of this hormone reported in earlier studies. My second protocol aimed towards quantifying the glucose-lowering effect of GLP-1-induced glucagon inhibition seen in patients with T2DM. The glucose-lowering effect of GLP-1 is due to both insulin stimulation leading to peripheral glucose disposal and glucagon inhibition resulting in decreased stimulation of hepatic glucose production. With a five-day protocol including both glycaemic and pancreatic clamps in ten patients with T2DM we were able to isolate the contribution of glucagon suppression to Topics: Blood Glucose; Diabetes Mellitus, Type 1; Diabetes Mellitus, Type 2; Dose-Response Relationship, Drug; Female; Glucagon; Glucagon-Like Peptide 1; Glucose Tolerance Test; Humans; Insulin; Male | 2010 |
Distinguishing among incretin-based therapies. Glucose-lowering effects of incretin-based therapies.
Extensive experience from randomized clinical trials demonstrates the efficacy of GLP-1 agonists and DPP-4 inhibitors as monotherapy and in combination with metformin and other agents, although reductions in FPG and PPG, and consequently A1C, are greater with GLP-1 agonists than with DPP-4 inhibitors. This difference may result from the pharmacologic levels of GLP-1 activity that are achieved with the GLP-1 agonists and their direct action on the GLP-1 receptor. The GLP-1 agonists have attributes that would make either of them an appropriate choice in the management of all 3 patients in our case studies, while either DPP-4 inhibitor would be an appropriate choice for Case 1. Differences in dosing, administration, safety, and tolerability should be considered. Topics: Adamantane; Aged; Blood Glucose; Diabetes Mellitus, Type 2; Dipeptides; Dipeptidyl-Peptidase IV Inhibitors; Exenatide; Female; Glucagon; Glucagon-Like Peptide 1; Glucagon-Like Peptide-1 Receptor; Glycated Hemoglobin; Humans; Hypoglycemic Agents; Incretins; Insulin; Insulin Resistance; Liraglutide; Male; Metformin; Middle Aged; Peptides; Pyrazines; Receptors, Glucagon; Sitagliptin Phosphate; Triazoles; Venoms | 2010 |
Distinguishing among incretin-based therapies. Patient education and self-management.
Working closely with patients and providing ongoing education, ideally in conjunction with a diabetes care team, can help ensure that the best treatment options are selected for an individual patient and that the patient is capable of effective self-management. Topics: Adamantane; Aged; Blood Glucose; Diabetes Mellitus, Type 2; Dipeptides; Dipeptidyl-Peptidase IV Inhibitors; Exenatide; Female; Glucagon; Glucagon-Like Peptide 1; Glucagon-Like Peptide-1 Receptor; Glycated Hemoglobin; Humans; Hypoglycemic Agents; Incretins; Insulin; Insulin Resistance; Liraglutide; Male; Metformin; Middle Aged; Patient Education as Topic; Peptides; Pyrazines; Receptors, Glucagon; Self Care; Sitagliptin Phosphate; Triazoles; Venoms | 2010 |
Distinguishing among incretin-based therapies. Safety, tolerability, and nonglycemic effects of incretin-based therapies.
The overall safety profiles of GLP-1 agonists and DPP-4 inhibitors are favorable, with a low incidence of hypoglycemia. This attribute, along with their weight and cardiovascular benefits, particularly with the GLP-1 agonists, make them appropriate choices in our 3 patient cases. Ongoing safety investigations with GLP-1 agonists and DPP-4 inhibitors will provide further clarity to the complete safety profiles of these agents. Topics: Adamantane; Aged; Blood Glucose; Diabetes Mellitus, Type 2; Dipeptides; Dipeptidyl-Peptidase IV Inhibitors; Exenatide; Female; Glucagon; Glucagon-Like Peptide 1; Glucagon-Like Peptide-1 Receptor; Glycated Hemoglobin; Humans; Hypoglycemia; Hypoglycemic Agents; Incretins; Insulin; Liraglutide; Male; Metformin; Middle Aged; Peptides; Pyrazines; Receptors, Glucagon; Risk; Sitagliptin Phosphate; Triazoles; Venoms; Weight Loss | 2010 |
Distinguishing among incretin-based therapies. Pathophysiology of type 2 diabetes mellitus: potential role of incretin-based therapies.
The multifactorial nature of the pathogenesis of T2DM provides an opportunity to combine treatments that act upon different mechanisms. In addition to improving insulin resistance and pancreatic β-cell dysfunction, the GLP-1 agonists and DPP-4 inhibitors improve the impaired incretin response, as well as increase insulin secretion and reduce glucagon secretion, both in a glucose-dependent manner. As a result of these multiple actions, the GLP-1 agonists and DPP-4 inhibitors lower both fasting and postprandial glucose levels. The effects of GLP-1 agonists tend to be greater, probably because they produce pharmacologic levels of GLP-1 compared to physiologic levels with the DPP-4 inhibitors. Another difference is that unlike the DPP-4 inhibitors, the GLP-1 agonists also slow gastric emptying and promote satiety. Topics: Adamantane; Aged; Blood Glucose; Diabetes Mellitus, Type 2; Dipeptides; Exenatide; Female; Glucagon; Glucagon-Like Peptide 1; Humans; Hypoglycemic Agents; Incretins; Insulin-Secreting Cells; Liraglutide; Male; Metformin; Middle Aged; Peptides; Pyrazines; Severity of Illness Index; Sitagliptin Phosphate; Time Factors; Triazoles; Venoms | 2010 |
Distinguishing among incretin-based therapies. Introduction.
The "treat to target" approach is to quickly achieve the target glycosylated hemoglobin (AIC) goal of <7% in most people, and then intensify or change therapy as needed to maintain glycemic control. Results of an online survey demonstrate uncertainty regarding the clinical differences between glucagon-like peptide (GLP-1) agonists and dipeptidyl peptidase (DPP)-4 inhibitors. The increasingly important roles of the GLP-1 agonists and DPP-4 inhibitors stem from their overall good efficacy and safety profiles compared with other treatment options. Topics: Adamantane; Blood Glucose; Diabetes Mellitus, Type 2; Dipeptides; Dipeptidyl-Peptidase IV Inhibitors; Drug Administration Schedule; Exenatide; Gastric Inhibitory Polypeptide; Glucagon-Like Peptide 1; Glucagon-Like Peptide-1 Receptor; Humans; Hypoglycemic Agents; Incretins; Insulin; Insulin Resistance; Insulin-Secreting Cells; Liraglutide; Metformin; Peptides; Pyrazines; Receptors, Glucagon; Sitagliptin Phosphate; Triazoles; Venoms | 2010 |
In vivo expression of HGF/NK1 and GLP-1 From dsAAV vectors enhances pancreatic ß-cell proliferation and improves pathology in the db/db mouse model of diabetes.
The purpose of the current study was to determine whether double-stranded adeno-associated virus (dsAAV)-mediated in vivo expression of β-cell growth factors, glucagon-like peptide-1 (GLP-1) and the NK1 fragment of hepatocyte growth factor (HGF/NK1) in β-cells, improves pathology in the db/db mouse model of type 2 diabetes. RESEARCH DESIGN AND METHODS; The glucoregulatory actions of GLP-1 and full-length HGF are well characterized. Here, we test the ability of HGF/NK1 to induce proliferation of exogenous islets and MIN6 β-cells. In addition, we target both GLP-1 and HGF/NK1 to endogenous β-cells using dsAAV vectors containing the mouse insulin-II promoter. We compare the abilities of these gene products to induce islet proliferation in vitro and in vivo and characterize their abilities to regulate diabetes after AAV-mediated delivery to endogenous islets of db/db mice.. Recombinant HGF/NK1 induces proliferation of isolated islets, and dsAAV-mediated expression of both GLP-1 and HGF/NK1 induces significant β-cell proliferation in vivo. Furthermore, both GLP-1 and HGF/NK1 expressed from dsAAV vectors enhance β-cell mass and insulin secretion in vivo and significantly delay the onset of hyperglycemia in db/db mice.. A single treatment with dsAAV vectors expressing GLP-1 or HGF/NK1 enhances islet growth and significantly improves pathology in a mouse model of type 2 diabetes. This represents the first example of a successful use of HGF/NK1 for diabetes therapy, providing support for direct AAV-mediated in vivo delivery of β-cell growth factors as a novel therapeutic strategy for the treatment of type 2 diabetes. Topics: Animals; Cell Division; Dependovirus; Diabetes Mellitus, Experimental; Diabetes Mellitus, Type 2; DNA Primers; Female; Genes, Reporter; Genetic Vectors; Glucagon-Like Peptide 1; Green Fluorescent Proteins; Hepatocyte Growth Factor; Insulin-Secreting Cells; Male; Mice; Mice, Inbred C57BL; Peptide Fragments; Plasmids; Polymerase Chain Reaction; Recombinant Proteins | 2010 |
NICE approves liraglutide for diabetic patients not achieving glucose control.
Topics: Diabetes Mellitus, Type 2; Drug Approval; Glucagon-Like Peptide 1; Humans; Hypoglycemic Agents; Liraglutide; United Kingdom | 2010 |
GIP: no longer the neglected incretin twin?
In the design of therapeutics to treat type 2 diabetes, researchers have exploited the observation that oral ingestion of nutrients leads to the secretion of glucose homeostasis-regulating incretin hormones (for example, glucagon-like-peptide-1) from the gut. Here, we discuss two recent papers that suggest that the "other" incretin hormone, gastric inhibitory polypeptide (GIP), also is important in the regulation of glucose homeostasis. These findings warrant further studies to unravel the mechanism of action of GIP in β-cells of the endocrine pancreas and to evaluate the possibility of designing novel therapeutics that target both incretin hormones. Topics: Animals; Blood Glucose; Diabetes Mellitus, Type 2; Gastric Inhibitory Polypeptide; Glucagon-Like Peptide 1; Humans; Incretins; Insulin-Secreting Cells; Models, Biological | 2010 |
Four weeks administration of Liraglutide improves memory and learning as well as glycaemic control in mice with high fat dietary-induced obesity and insulin resistance.
Liraglutide is a long-acting glucagon-like peptide-1 (GLP-1) mimetic which is a treatment option for type 2 diabetes. GLP-1 peptides, including Liraglutide, cross the blood-brain barrier and may additionally act to improve brain function. The present study tested the hypothesis that, in addition to its antihyperglycaemic actions, peripheral administration of Liraglutide exerts positive actions on cognitive function in mice with high fat dietary-induced obesity and insulin resistance.. Young Swiss TO mice maintained on high fat diet for 20 weeks received twice-daily injections of Liraglutide (200 µg/kg bw; sc) or saline vehicle over 28 days. An additional group of mice on standard diet received twice-daily saline injections. Energy intake, bodyweight, non-fasting plasma glucose and insulin concentrations were monitored at regular intervals. Glucose tolerance, open field assessment, object recognition testing and electrophysiological long-term potentiation (LTP) were performed at termination of the study.. Liraglutide treatment resulted in significant time-dependent reduction in bodyweight and energy intake, whilst improving non-fasting glucose and normalizing glucose tolerance. Although Liraglutide did not alter general behaviour, treated mice exhibited marked increase in recognition index (RI) during object recognition testing, indicative of enhanced learning and memory ability. Furthermore, Liraglutide rescued the deleterious effects of high fat diet on hippocampal LTP of neurotransmission following both chronic and direct intracerebroventricular (icv) administration.. Liraglutide administered peripherally not only improves metabolic parameters but exerts additional beneficial effects on cognitive function and hippocampal synaptic plasticity. Whether therapy with GLP-1 mimetics has similar effects in humans with type 2 diabetes needs to be established. Topics: Animals; Blood Glucose; Cognition; Diabetes Mellitus, Type 2; Glucagon-Like Peptide 1; Hypoglycemic Agents; Insulin Resistance; Liraglutide; Male; Memory; Mice; Obesity | 2010 |
3rd Annual Symposium on Self Monitoring of Blood Glucose (SMBG) Applications and Beyond, May 7-8, 2010, London, UK.
Topics: Biomarkers; Blood Glucose; Blood Glucose Self-Monitoring; Cardiovascular Diseases; Diabetes Complications; Diabetes Mellitus; Diabetes Mellitus, Type 2; Glucagon-Like Peptide 1; Guidelines as Topic; Humans; Hypoglycemic Agents; Insulin; Insulin Infusion Systems | 2010 |
[Pharmacological and clinical profiles of a human GLP-1 analogue, liraglutide (Victoza(®))].
Topics: Animals; Blood Glucose; Carcinogens; Cells, Cultured; Diabetes Mellitus, Type 2; Glucagon-Like Peptide 1; Humans; Hypoglycemic Agents; Insulin-Secreting Cells; Liraglutide; Mice; Rats | 2010 |
Liraglutide: can it make a difference in the treatment of type 2 diabetes?
Despite advances in the management of type 2 diabetes, glycaemic control remains suboptimal for many patients because of the complexities of disease progression and the need to balance improved glycaemic control against adverse treatment effects, particularly weight gain and hypoglycaemia. Thus, the development of new antidiabetes therapies continues in earnest. Incretin hormones have been the recent focus of research, as they account for up to 70% of the insulin response following a meal. There is also a high concordance between the physiological actions of one hormone, glucagon-like peptide-1 (GLP-1), and the therapeutic needs of patients. As native human GLP-1 has a half life of only approximately 2 min, researchers have developed molecules that act as GLP-1 receptor agonists or inhibit the enzyme responsible for GLP-1 degradation (dipeptidyl peptidase-4). Liraglutide, a human GLP-1 analogue sharing 97% of its amino acid sequence identity with native GLP-1, has been approved for use as monotherapy (not in Europe) and in combination with selected oral agents. In this supplement, we summarise key liraglutide data, offer practical insight into what we might expect of liraglutide in clinical use and examine selected case studies. For reasons of the safety and efficacy of GLP-1 receptor agonists, many thought leaders believe that these will become background therapy for majority of patients in the coming years. This supplement will serve as a resource from which readers can extract information concerning the potential benefits for patients who are overweight, losing pancreatic beta-cell function and drifting towards the ravaging effects of chronic hyperglycaemia. Topics: Diabetes Mellitus, Type 2; Dipeptidyl-Peptidase IV Inhibitors; Disease Progression; Drug Approval; Drug Therapy, Combination; Glucagon-Like Peptide 1; Glucagon-Like Peptide-1 Receptor; Half-Life; Humans; Hypoglycemia; Hypoglycemic Agents; Insulin; Insulin-Secreting Cells; Liraglutide; Obesity; Receptors, Glucagon | 2010 |
[GLP-1 (glucagon-like peptide 1)].
Topics: Diabetes Mellitus, Type 2; Glucagon-Like Peptide 1; Humans | 2010 |
A comparison of preferences for two GLP-1 products--liraglutide and exenatide--for the treatment of type 2 diabetes.
To use time trade-off (TTO) to compare patient preferences for profiles of two glucagon-like peptide (GLP-1) products for the treatment of type 2 diabetes (liraglutide and exenatide) that vary on four key attributes - efficacy (as measured by hemoglobin A(1C)), incidence of nausea, incidence of hypoglycemia, and dosing frequency (QD vs. BID) - and measure the contribution of those attributes to preferences.. A total of 382 people with T2DM were recruited to participate in an internet-based survey consisting of a series of health-related questions, a conjoint exercise and a set of time trade-off items. In the conjoint exercise, respondents were presented with eight pairs of hypothetical GLP-1 profiles, and completed a time-tradeoff exercise for each pair.. The product profile representing liraglutide was preferred by 96% of respondents and resulted in significantly higher health utilities (0.038) than the product profile representing exenatide (0.978 vs. 0.94, p < 0.05). Estimated preference scores from the conjoint analysis revealed that efficacy measured by hemoglobin A(1C) is the most important attribute, followed by nausea, hypoglycemia, and dosing schedule.. On-line participants may not represent 'typical' type 2 diabetes patients, and brief product profiles represented results from clinical trials, not clinical practice. Based on the four attributes presented, patients prefer liraglutide over exenatide. Preference is based on superior efficacy and less nausea more than less hypoglycemia and once-daily dosing. Topics: Adult; Diabetes Mellitus, Type 2; Drug Administration Schedule; Exenatide; Female; Glucagon-Like Peptide 1; Glycated Hemoglobin; Humans; Hypoglycemia; Hypoglycemic Agents; Liraglutide; Male; Middle Aged; Nausea; Patient Preference; Peptides; Quality of Life; Socioeconomic Factors; Venoms | 2010 |
[New data from the US-American Diabetes Congress. GLP-1 effect: more than reducing blood glucose].
Topics: Blood Glucose; Body Weight; Diabetes Mellitus, Type 2; Dose-Response Relationship, Drug; Drug Therapy, Combination; Glucagon-Like Peptide 1; Glycated Hemoglobin; Humans; Hypoglycemia; Hypoglycemic Agents; Liraglutide; Pyrazines; Randomized Controlled Trials as Topic; Sitagliptin Phosphate; Triazoles | 2010 |
Dulaglutide, a long-acting GLP-1 analog fused with an Fc antibody fragment for the potential treatment of type 2 diabetes.
Dulaglutide (LY-2189265) is a novel, long-acting glucagon-like peptide 1 (GLP-1) analog being developed by Eli Lilly for the treatment of type 2 diabetes mellitus (T2DM). Dulaglutide consists of GLP-1(7-37) covalently linked to an Fc fragment of human IgG4, thereby protecting the GLP-1 moiety from inactivation by dipeptidyl peptidase 4. In vitro and in vivo studies on T2DM models demonstrated glucose-dependent insulin secretion stimulation. Pharmacokinetic studies demonstrated a t1/2 in humans of up to 90 h, making dulaglutide an ideal candidate for once-weekly dosing. Clinical trials suggest that dulaglutide reduces plasma glucose, and has an insulinotropic effect increasing insulin and C-peptide levels. Two phase II clinical trials demonstrated a dose-dependent reduction in glycated hemoglobin (HbA1c) of up to 1.52% compared with placebo. Side effects associated with dulaglutide administration were mainly gastrointestinal. To date, there have been no reports on the formation of antibodies against dulaglutide, but, clearly, long-term data will be needed to asses this and other possible side effects. The results of several phase III clinical trials are awaited for clarification of the expected effects on HbA1c and body weight. If dulaglutide possesses similar efficacy to other GLP-1 analogs, the once-weekly treatment will most likely be welcomed by patients with T2DM. Topics: Blood Glucose; C-Peptide; Clinical Trials as Topic; Diabetes Mellitus, Type 2; Gastrointestinal Diseases; Glucagon-Like Peptide 1; Glucagon-Like Peptides; Glycated Hemoglobin; Humans; Hypoglycemic Agents; Immunoglobulin Fc Fragments; Insulin; Recombinant Fusion Proteins; Treatment Outcome | 2010 |
Results of a model analysis of the cost-effectiveness of liraglutide versus exenatide added to metformin, glimepiride, or both for the treatment of type 2 diabetes in the United States.
Nearly half of all US patients with type 2 diabetes mellitus (T2DM) are unable to maintain adequate glycosylated hemoglobin (HbA₁(c)) control (ie, <7.0%).. The aim of this work was to determine the long-term cost-effectiveness of incretin-based therapy with once-daily liraglutide (vs twice-daily exenatide) combined with metformin, glimepiride, or both for the treatment of T2DM.. Patient data were obtained from the Liraglutide Effect and Action in Diabetes 6 (LEAD 6) trial. Baseline data included mean HbA₁(c) (8.15%), age (56.7 years), disease duration (8 years), sex, body mass index, blood pressure, lipid levels, cardiovascular and renal risk factors, and other complications. The IMS Center for Outcomes Research Diabetes Model was used to project and compare lifetime (ie, 35-year) clinical and economic outcomes for once-daily liraglutide 1.8 mg compared with twice-daily exenatide 10 (ig, each used as add-on therapy with maximum-dose metformin and/or glimepiride. Treatment-effect assumptions were also derived from the LEAD 6 trial. Transition probabilities, utilities, and complication costs were obtained from published sources. All outcomes were discounted at 3% per annum, and the analysis was conducted from the perspective of a third-party payer in the United States.. The base-case analysis indicated that, compared with exenatide, liraglutide add-on therapy was associated with a mean (SD) increase in life expectancy of 0.187 (0.250) years and an increase in qualityadjusted life-years of 0.322 (0.164) years. Compared with exenatide, total lifetime treatment costs for liraglutide were $12,956 higher, yielding an incremental costeffectiveness ratio (ICER) of $40,282. However, the costs of diabetes-related complications were lower with liraglutide than with exenatide ($49,784 vs $52,429, respectively). Sensitivity analysis indicated that setting patient HbA(1c) levels at the 95% upper limit reduced the ICER for liraglutide compared with exenatide to $33,086.. In this model analysis using published clinical data and current medication acquisition price assumptions, liraglutide (in combination with metformin and/or glimepiride) appeared to be cost-effective in the US payer setting over a 35-year time horizon. Topics: Cost-Benefit Analysis; Diabetes Mellitus, Type 2; Drug Therapy, Combination; Exenatide; Female; Glucagon-Like Peptide 1; Glycated Hemoglobin; Humans; Hypoglycemic Agents; Liraglutide; Male; Metformin; Middle Aged; Models, Econometric; Peptides; Quality-Adjusted Life Years; Statistics, Nonparametric; Sulfonylurea Compounds; United States; Venoms | 2010 |
Recent advances in clinical application of gut hormones.
Topics: Appetite Regulation; Biomedical Research; Diabetes Mellitus, Type 2; Drug Design; Energy Metabolism; Forecasting; Gastrointestinal Motility; Ghrelin; Glucagon-Like Peptide 1; Humans; Obesity; Pancreatic Polypeptide; Peptide YY | 2010 |
[Effects of Gastric bypass surgery on the apoptosis of islet β-cells in type 2 nonobese diabetic (NOD) rats and its mechanism].
To investigate the effects of Gastric bypass surgery on the apoptosis of islet β-cells in type 2 nonobese diabetic (NOD) rats and its mechanisms.. Seventy-two 8-week-old GK rats were randomly divided into four groups:operation group (group O, n = 18), sham operation group (group S, n = 18), diet control group (group F, n = 18) and control group (group C, n = 18). The levels of fasting, postprandial blood glucose, insulin and glucagon-like peptide-1 (GLP-1) were measured and compared among the 4 groups before the operation and at 1, 2, 4 and 8 weeks following the operation. The blood samples were collected at 2, 4 and 8 weeks after the operation for the measurement of postprandial blood glucose, and then the rats in batches (6 rats in each group) were decapitated to retrieve the pancreas. The apoptosis of the islet β-cells was detected by using TUNEL assay, and the expression of apoptosis-related proteins Bcl-2, Bax was measured with immunohistochemistry.. As for group O, the fasting blood glucose level decreased from (16.2 ± 0.8) mmol/L before the operation to respectively (9.2 ± 0.6) mmol/L and (9.7 ± 0.7) mmol/L at 4 and 8 weeks after the operation; postprandial blood glucose decreased from (31.1 ± 1.1) mmol/L before the operation to respectively (13.1 ± 0.7) mmol/L and (12.3 ± 0.7) mmol/L at 4 and 8 weeks after the operation. Fasting insulin level increased from (28.0 ± 1.2) mU/L before the operation to respectively (62.8 ± 1.9) mU/L and (61.7 ± 1.4) mU/L at 4 and 8 weeks after the operation; and at 4 and 8 weeks after the operation postprandial insulin level was (77.4 ± 1.1) mU/L and (77.1 ± 1.0) mU/L. At 2 weeks from the operation, the fasting GLP-1 in group O increased from (10.7 ± 1.0) pmol/L to (13.5 ± 0.8) pmol/L, and respectively to (26.1 ± 0.9) pmol/L and (25.3 ± 1.2) pmol/L at 4 and 8 weeks after the operation. The differences in the above-mentioned items before and after the operation were all significant in group O (P < 0.05), and the differences in the items among group O and the other three groups (P < 0.05) were all significant as well. In group O, the apoptosis rate of pancreatic islet cell decreased to (5.9 ± 0.7)% at 4 weeks from the operation, and (6.3 ± 1.1)% at 8 weeks from the operation (P < 0.05). The expression of Bcl-2 protein in group O was 31.3 ± 1.5, 35.7 ± 1.0 and 35.8 ± 0.8 at 2, 4 and 8 weeks post operation, which was significantly higher in statistics than those of the same time point in the other three groups (P < 0.05). The expression of Bax protein in group O was 13.3 ± 0.9, 10.8 ± 0.9 and 10.9 ± 1.1 at 2, 4 and 8 weeks from the operation, which was significantly lower in statistics than those of the same time point in the other three groups (P < 0.05).. Gastric bypass surgery can significantly reduce the blood glucose level and promote the secretion of GLP-1, and therefore inhibit the apoptosis of the islet β cells in diabetic rats through the Bcl-2 pathway. Topics: Animals; Apoptosis; bcl-2-Associated X Protein; Blood Glucose; Diabetes Mellitus, Type 2; Disease Models, Animal; Gastric Bypass; Glucagon-Like Peptide 1; Insulin; Islets of Langerhans; Proto-Oncogene Proteins c-bcl-2; Rats | 2010 |
[Innovations in the treatment of type 2 diabetes mellitus: use of incretins].
There is a new class of drugs used to treat diabetes mellitus (DM). It has come into existence after long-term studies of the fundamentally new hemostastic mechanism in glucose regulation via the gastrointestinal hormones incretins. With the advent of this class of drugs that minimize routine adverse reactions (weight gain, glycemic risk, nephro-, hepato-, and cardiotoxic effects, etc.), there is hope for a delay in the progressive increase of secretory function and beta-cell mass, which is inevitable during standard treatment (which presages the eventual need to initiate insulin therapy 7-10 years after the onset of the disease). The mechanism of action of incretins is considered. The place of novel agents (glucagon-like peptide-1 receptor agonists and dipeptidyl peptidase-4 inhibitors) in the total pattern of treatment for type 2 DM, indications for and contraindications to their use, benefits versus traditional glucose-lowering therapy (the inestimable advantage of these drugs is no risk for hypoglycemia), and prospects for their future application are discussed. Topics: Diabetes Mellitus, Type 2; Dipeptidyl-Peptidase IV Inhibitors; Glucagon-Like Peptide 1; Glucagon-Like Peptide-1 Receptor; Humans; Hypoglycemic Agents; Incretins; Receptors, Glucagon; Therapies, Investigational | 2010 |
[Glucagon-like peptide-1 analogues in type 2 diabetes: beyond glycemic control].
Topics: Diabetes Mellitus, Type 2; Glucagon-Like Peptide 1; Humans; Hyperglycemia | 2010 |
Pharmacokinetic and pharmacodynamic evaluation of site-specific PEGylated glucagon-like peptide-1 analogs as flexible postprandial-glucose controllers.
The rapid elimination of glucagon-like peptide-1 (GLP-1) is the main impediment to its anti-diabetic utility. Here, we tried to improve its poor pharmacokinetic/pharmacodynamic profiles using PEGylation. The site-specific (Lys(34)) PEGylated GLP-1s were synthesized with PEGs of 2, 5, and 10 kDa, respectively. Oral glucose tolerance tests using db/db mice showed that these three PEGylated GLP-1s (5 nmol/kg) specifically stabilized plasma glucose levels when intraperitoneally (i.p.) administered at 30, 30-120, or 120-360 min preoral glucose treatment, respectively (total hypoglycemic degree: 60.5 +/- 5.0%, approximately 67.2 +/- 2.3%, and approximately 59.4 +/- 4.3%, respectively). Particularly, Lys(34)-PEG(10K)-GLP-1 showed an stable hypoglycemic efficacy when administered up to 360 min preglucose. The different anti-diabetic effects of PEGylated GLP-1s were attributed to their augmented pharmacokinetics and metabolic resistance. These analogs had higher metabolic stabilities in rat plasma, liver and kidney homogenates, and extended pharmacokinetic profiles with the greater circulating half-lives (26.6, 64.5, and 105.5 min for Lys(34)-PEG(2,5,10 K)-GLP-1s, respectively, vs. 8.5 min for GLP-1, at elimination phases after i.p. injections) in ICR mice. Our findings suggest that GLP-1 substituted with a PEG of an appropriate Mw at Lys(34) could be used as a promising type 2 anti-diabetic agent to timely control postprandial glucose levels. Topics: Animals; Blood Glucose; Cells, Cultured; Diabetes Mellitus, Experimental; Diabetes Mellitus, Type 2; Drug Carriers; Drug Stability; Female; Glucagon-Like Peptide 1; Hypoglycemic Agents; Insulin; Insulin Secretion; Islets of Langerhans; Male; Mice; Mice, Inbred C57BL; Mice, Inbred ICR; Peptide Fragments; Polyethylene Glycols; Postprandial Period; Protein Binding; Rats | 2009 |
Treatment of type 2 diabetes with incretin-based therapies.
Topics: Diabetes Mellitus, Type 2; Glucagon-Like Peptide 1; Glycated Hemoglobin; Humans; Hypoglycemic Agents; Liraglutide; Randomized Controlled Trials as Topic | 2009 |
Treatment of patients with diabetes with GLP-1 analogues or DPP-4- inhibitors: a hot topic for cardiologists?
Novel drugs for the treatment of patients with diabetes are of interest for cardiologists if they reduce the risk of cardiovascular events. However, as documented by the current discussion about the potential benefits of glitazones, high hopes can fail. Initial beneficial cardiovascular effects shown in proof-of-concept studies were muted by the apparent higher mortality in the metaanalysis of studies with rosiglitazone. Having this in mind, how should one judge about new, emerging antidiabetic therapies, in particular those influencing the incretin axis? The rapidly increasing use of GLP-1 analogues and DPP-4 inhibitors for the treatment of type 2 diabetes mellitus may be of major interest for the cardiologist. Potential beneficial actions on the cardiovascular system so far shown in animal experiments and small proof of concept studies may provide the rationale for using these drugs specifically in diabetic patients with secondary complications such as macrovascular disease or diabetic cardiomyopathy. Theoretically, these new therapies could also proof beneficial in patients with heart failure, independently of concomittend diabetes mellitus. However, many unanswered questions need to be addressed in the near future to extend the experimental findings to potential benefits of real life patients. In summary a new class of antidiabetic drugs, which could possibly directly influence cardiovascular effects of diabetes mellitus and thus possibly treat or even prevent life threatening complications has become available. Further studies both assessing surrogate parameters as well as hard endpoint studies are needed to support the hypothesis generated from the summarized experimental studies. Topics: Cardiovascular System; Diabetes Mellitus, Type 2; Dipeptidyl-Peptidase IV Inhibitors; Glucagon-Like Peptide 1; Humans; Hypoglycemic Agents; Incretins | 2009 |
First-phase insulin secretion restoration and differential response to glucose load depending on the route of administration in type 2 diabetic subjects after bariatric surgery.
The purpose of this study was to elucidate the mechanisms of diabetes reversibility after malabsorptive bariatric surgery.. Peripheral insulin sensitivity and beta-cell function after either intravenous (IVGTT) or oral glucose tolerance (OGTT) tests and minimal model analysis were assessed in nine obese, type 2 diabetic subjects before and 1 month after biliopancreatic diversion and compared with those in six normal-weight control subjects. Insulin-dependent whole-body glucose disposal was measured by the euglycemic clamp, and glucose-dependent insulinotropic polypeptide (GIP) and glucagon-like peptide-1 (GLP-1) were also measured.. The first phase of insulin secretion after the IVGTT was fully normalized after the operation. The disposition index from OGTT data was increased about 10-fold and became similar to the values found in control subjects, and the disposition index from IVGTT data increased about 3.5-fold, similarly to what happened after the euglycemic clamp. The area under the curve (AUC) for GIP decreased about four times (from 3,000 +/- 816 to 577 +/- 155 pmol x l(-1) x min, P < 0.05). On the contrary, the AUC for GLP1 almost tripled (from 150.4 +/- 24.4 to 424.4 +/- 64.3 pmol x l(-1) . min, P < 0.001). No significant correlation was found between GIP or GLP1 percent changes and modification of the sensitivity indexes independently of the route of glucose administration.. Restoration of the first-phase insulin secretion and normalization of insulin sensitivity in type 2 diabetic subjects after malabsorptive bariatric surgery seem to be related to the reduction of the effect of some intestinal factor(s) resulting from intestinal bypass. Topics: Adult; Bariatric Surgery; Diabetes Mellitus, Type 2; Drug Administration Routes; Female; Gastric Inhibitory Polypeptide; Glucagon-Like Peptide 1; Glucose; Glucose Tolerance Test; Humans; Insulin; Insulin Secretion; Male; Middle Aged; Models, Theoretical | 2009 |
Four weeks of near-normalisation of blood glucose improves the insulin response to glucagon-like peptide-1 and glucose-dependent insulinotropic polypeptide in patients with type 2 diabetes.
The incretin effect is attenuated in patients with type 2 diabetes mellitus, partly as a result of impaired beta cell responsiveness to glucose-dependent insulinotropic polypeptide (GIP) and glucagon-like peptide-1 (GLP-1). The aim of the present study was to investigate whether 4 weeks of near-normalisation of the blood glucose level could improve insulin responses to GIP and GLP-1 in patients with type 2 diabetes.. Eight obese patients with type 2 diabetes with poor glycaemic control (HbA(1c) 8.6 +/- 1.3%), were investigated before and after 4 weeks of near-normalisation of blood glucose (mean blood glucose 7.4 +/- 1.2 mmol/l) using insulin treatment. Before and after insulin treatment the participants underwent three hyperglycaemic clamps (15 mmol/l) with infusion of GLP-1, GIP or saline. Insulin responses were evaluated as the incremental area under the plasma C-peptide curve.. Before and after near-normalisation of blood glucose, the C-peptide responses did not differ during the early phase of insulin secretion (0-10 min). The late phase C-peptide response (10-120 min) increased during GIP infusion from 33.0 +/- 8.5 to 103.9 +/- 24.2 (nmol/l) x (110 min)(-1) (p < 0.05) and during GLP-1 infusion from 48.7 +/- 11.8 to 126.6 +/- 32.5 (nmol/l) x (110 min)(-1) (p < 0.05), whereas during saline infusion the late-phase response did not differ before vs after near-normalisation of blood glucose (40.2 +/- 11.2 vs 46.5 +/- 12.7 [nmol/l] x [110 min](-1)).. Near-normalisation of blood glucose for 4 weeks improves beta cell responsiveness to both GLP-1 and GIP by a factor of three to four. No effect was found on beta cell responsiveness to glucose alone. CLINICALTRIALS.GOV ID NO.: NCT 00612950.. This study was supported by The Novo Nordisk Foundation, The Medical Science Research Foundation for Copenhagen. Topics: Adult; Blood Glucose; C-Peptide; Diabetes Mellitus, Type 2; Fasting; Fructosamine; Gastric Inhibitory Polypeptide; Glucagon-Like Peptide 1; Glycated Hemoglobin; Humans; Infusions, Intravenous; Insulin; Male; Middle Aged; Reference Values | 2009 |
Nutrient-driven incretin secretion into intestinal lymph is different between diabetic Goto-Kakizaki rats and Wistar rats.
The incretin hormones gastric inhibitory polypeptide (GIP) and glucagon-like peptide-1 (GLP-1) augment postprandial glucose-mediated insulin release from pancreatic beta-cells. The Goto-Kakizaki (GK) rat is a widely used, lean rodent model of Type 2 diabetes; however, little is known regarding the incretin secretion profile to different nutrients in these rats. We have recently shown that lymph is a sensitive medium to measure incretin secretion in rodents and probably the preferred compartment for GLP-1 monitoring. To characterize the meal-induced incretin profile, we compared lymphatic incretin concentrations in the GK and Wistar rat after enteral macronutrient administration. After cannulation of the major mesenteric lymphatic duct and duodenum, each animal received an intraduodenal bolus of either a fat emulsion, dextrin, a mixed meal, or saline. Lymph was collected for 3 h and analyzed for triglyceride, glucose, GLP-1, and GIP content. There was no statistical difference in GIP or GLP-1 secretion after a lipid bolus between GK and Wistar rats. Dextrin and a mixed meal both increased incretin concentration area under the curve, however, significantly less in GK rats compared with Wistar rats (dextrin GIP: 707 +/- 106 vs. 1,373 +/- 114 pg ml(-1) h, respectively, P < 0.001; dextrin GLP-1: 82.7 +/- 24.3 vs. 208.3 +/- 26.3 pM/h, respectively, P = 0.001). After administration of a carbohydrate-containing meal, GK rats were unable to mount as robust a response of both GIP and GLP-1 compared with Wistar rats, a phenomenon not seen after a lipid meal. We propose a similar, glucose-mediated incretin secretion pathway defect of both K and L cells in GK rats. Topics: Animals; Dextrins; Diabetes Mellitus, Type 2; Diet; Dietary Carbohydrates; Dietary Fats; Disease Models, Animal; Duodenum; Enteroendocrine Cells; Gastric Inhibitory Polypeptide; Glucagon-Like Peptide 1; Glucose; Intestinal Secretions; Lymph; Male; Postprandial Period; Rats; Rats, Wistar; Sodium Chloride, Dietary; Time Factors; Triglycerides | 2009 |
GLP-1R agonist liraglutide activates cytoprotective pathways and improves outcomes after experimental myocardial infarction in mice.
Glucagon-like peptide-1 receptor (GLP-1R) agonists are used to treat type 2 diabetes, and transient GLP-1 administration improved cardiac function in humans after acute myocardial infarction (MI) and percutaneous revascularization. However, the consequences of GLP-1R activation before ischemic myocardial injury remain unclear.. We assessed the pathophysiology and outcome of coronary artery occlusion in normal and diabetic mice pretreated with the GLP-1R agonist liraglutide.. Male C57BL/6 mice were treated twice daily for 7 days with liraglutide or saline followed by induction of MI. Survival was significantly higher in liraglutide-treated mice. Liraglutide reduced cardiac rupture (12 of 60 versus 46 of 60; P = 0.0001) and infarct size (21 +/- 2% versus 29 +/- 3%, P = 0.02) and improved cardiac output (12.4 +/- 0.6 versus 9.7 +/- 0.6 ml/min; P = 0.002). Liraglutide also modulated the expression and activity of cardioprotective genes in the mouse heart, including Akt, GSK3beta, PPARbeta-delta, Nrf-2, and HO-1. The effects of liraglutide on survival were independent of weight loss. Moreover, liraglutide conferred cardioprotection and survival advantages over metformin, despite equivalent glycemic control, in diabetic mice with experimental MI. The cardioprotective effects of liraglutide remained detectable 4 days after cessation of therapy and may be partly direct, because liraglutide increased cyclic AMP formation and reduced the extent of caspase-3 activation in cardiomyocytes in a GLP-1R-dependent manner in vitro.. These findings demonstrate that GLP-1R activation engages prosurvival pathways in the normal and diabetic mouse heart, leading to improved outcomes and enhanced survival after MI in vivo. Topics: Animals; Blood Glucose; Body Weight; Cardiomegaly; Diabetes Mellitus, Type 2; Diabetic Angiopathies; Disease Models, Animal; Glucagon-Like Peptide 1; Glucagon-Like Peptide-1 Receptor; Heart; Humans; Liraglutide; Male; Mice; Mice, Inbred C57BL; Myocardial Infarction; Organ Size; Receptors, Glucagon | 2009 |
Evaluation of the antidiabetic effects of dipeptidyl peptidase-IV inhibitor ASP8497 in streptozotocin-nicotinamide-induced mildly diabetic mice.
Gastrointestinal hormone glucagon-like peptide-1 (GLP-1) has a potent glucose-dependent insulinotropic effect and is rapidly degraded by dipeptidyl peptidase (DPP)-IV. Therefore, the use of DPP-IV inhibitors is being actively explored as a novel approach to the treatment of type 2 diabetes. The present study investigated the antidiabetic effects of the DPP-IV inhibitor ASP8497 in streptozotocin-nicotinamide-induced mildly diabetic mice which possess aggravation of glucose tolerance due to loss of early-phase insulin secretion. ASP8497 exhibited good oral bioavailability with potent inhibition of plasma DPP-IV activity. This inhibitory activity lasted up to 24 h when administered at 5 mg/kg twice a day or 10 mg/kg once a day. A single oral administration of ASP8497 (0.3-3 mg/kg) significantly improved glucose tolerance by increasing plasma insulin and GLP-1 levels during the oral glucose or liquid meal tolerance tests. These effects were seen not only immediately, but also 8 h after administration. In contrast, ASP8497 (0.3-10 mg/kg) had no significant effect on blood glucose and plasma insulin levels under fasting conditions. Furthermore, repeated administration of ASP8497 (5 mg/kg twice a day or 10 mg/kg once a day) for 25 days significantly decreased nonfasting blood glucose and HbA(1c) levels. These results suggest that ASP8497 is a potent and long-acting DPP-IV inhibitor that improves glucose tolerance through glucose-dependent insulinotropic action via the elevation of the GLP-1 level in streptozotocin-nicotinamide-induced mildly diabetic mice. It is expected to be useful as a therapeutic agent for impaired glucose tolerance and type 2 diabetes. Topics: Administration, Oral; Animals; Diabetes Mellitus, Experimental; Diabetes Mellitus, Type 2; Dipeptidyl Peptidase 4; Dipeptidyl-Peptidase IV Inhibitors; Drug Evaluation, Preclinical; Fasting; Glucagon-Like Peptide 1; Glucose Tolerance Test; Glycated Hemoglobin; Insulin; Male; Mice; Mice, Inbred ICR; Pancreas; Piperidines; Pyrrolidines | 2009 |
Engineered glucagon-like peptide-1-producing hepatocytes lower plasma glucose levels in mice.
Glucagon-like peptide (GLP)-1 is an incretin hormone with well-characterized antidiabetic properties, including glucose-dependent stimulation of insulin secretion and enhancement of beta-cell mass. GLP-1 agonists have recently been developed and are now in clinical use for the treatment of type 2 diabetes. Rapid degradation of GLP-1 by enzymes including dipeptidyl-peptidase (DPP)-IV and neutral endopeptidase (NEP) 24.11, along with renal clearance, contribute to a short biological half-life, necessitating frequent injections to maintain therapeutic efficacy. Gene therapy may represent a promising alternative approach for achieving long-term increases in endogenous release of GLP-1. We have developed a novel strategy for glucose-regulated production of GLP-1 in hepatocytes by expressing a DPP-IV-resistant GLP-1 peptide in hepatocytes under control of the liver-type pyruvate kinase promoter. Adenoviral delivery of this construct to hepatocytes in vitro resulted in production and secretion of bioactive GLP-1 as measured by a luciferase-based bioassay developed to detect the NH2-terminally modified GLP-1 peptide engineered for this study. Transplantation of encapsulated hepatocytes into CD-1 mice resulted in an increase in plasma GLP-1 levels that was accompanied by a significant reduction in fasting plasma glucose levels. The results from this study demonstrate that a gene therapy approach designed to induce GLP-1 production in hepatocytes may represent a novel strategy for long-term secretion of bioactive GLP-1 for the treatment of type 2 diabetes. Topics: Adenoviridae; Animals; Biological Assay; Blood Glucose; Cell Line; Diabetes Mellitus, Type 2; Down-Regulation; Genetic Engineering; Glucagon-Like Peptide 1; Glucose; Hepatocytes; Humans; Male; Mice; Transduction, Genetic | 2009 |
Antidiabetic effects of dipeptidyl peptidase-IV inhibitors and sulfonylureas in streptozotocin-nicotinamide-induced mildly diabetic mice.
The present study investigated the antidiabetic effects of the dipeptidyl peptidase (DPP)-IV inhibitors ASP8497 and vildagliptin, and the sulfonylureas glibenclamide and gliclazide in streptozotocin-nicotinamide-induced mildly diabetic mice. A single administration of ASP8497 and vildagliptin significantly improved glucose tolerance by increasing plasma insulin and glucagon-like peptide-1 levels. In addition, a single administration of glibenclamide and gliclazide also caused significant improvement in glucose tolerance with an accompanying increase in the plasma insulin level. Subsequently, the effects of a 1-week chronic daily dosing of DPP-IV inhibitors and sulfonylureas were investigated. All drugs significantly improved glucose tolerance on day 1 of chronic daily dosing. After 1 week of chronic daily dosing, the DPP-IV inhibitors caused a significant improvement in glucose tolerance similar to those observed on day 1 by increasing the plasma insulin and glucagon-like peptide-1 levels. In contrast, the sulfonylureas had no significant improving or insulinotropic effect. Furthermore, ASP8497 also had an antihyperglycemic effect and improved pancreatic histopathologic lesions in a 4-week chronic daily dosing study. These results suggest that chronic daily dosing of sulfonylureas had virtually no antidiabetic effects because of marked attenuation of the insulinotropic action in streptozotocin-nicotinamide-induced mildly diabetic mice. In contrast, the antidiabetic efficacy of DPP-IV inhibitors, including ASP8497, did not change even after chronic daily dosing; therefore, DPP-IV inhibitors are useful as a therapeutic agent for impaired glucose tolerance and type 2 diabetes mellitus. Topics: Animals; Blood Glucose; Diabetes Mellitus, Experimental; Diabetes Mellitus, Type 2; Dipeptidyl-Peptidase IV Inhibitors; Gliclazide; Glucagon-Like Peptide 1; Glucose Intolerance; Glyburide; Hypoglycemic Agents; Insulin; Male; Mice; Mice, Inbred ICR; Niacinamide; Piperidines; Pyrrolidines; Sulfonylurea Compounds | 2009 |
Effect of GLP-1 treatment on bone turnover in normal, type 2 diabetic, and insulin-resistant states.
It has been suggested that hormones released after nutrient absorption, such as glucose-dependent insulinotropic peptide (GIP) and glucagon-like peptide 2 (GLP-2), could be responsible for changes in bone resorption. However, information about the role of GLP-1 in this regard is scanty. Diabetes-related bone loss occurs as a consequence of poor control of glucose homeostasis, but the relationship between osteoporosis and type 2 diabetes remains unclear. Since GLP-1 is decreased in the latter condition, we evaluated some bone characteristics in streptozotocin-induced type 2 diabetic (T2D) and fructose-induced insulin-resistant (IR) rat models compared to normal (N) and the effect of GLP-1 or saline (control) treatment (3 days by osmotic pump). Blood was taken before and after treatment for plasma measurements; tibiae and femora were collected for gene expression of bone markers (RT-PCR) and structure (microCT) analysis. Compared to N, plasma glucose and insulin were, respectively, higher and lower in T2D; osteocalcin (OC) and tartrate-resistant alkaline phosphatase 5b were lower; phosphate in IR showed a tendency to be higher; PTH was not different in T2D and IR; all parameters were unchanged after GLP-1 infusion. Bone OC, osteoprotegerin (OPG) and RANKL mRNA were lower in T2D and IR; GLP-1 increased OC and OPG in all groups and RANKL in T2D. Compared to N, trabecular bone parameters showed an increased degree of anisotropy in T2D and IR, which was reduced after GLP-1. These findings show an insulin-independent anabolic effect of GLP-1 and suggest that GLP-1 could be a useful therapeutic agent for improving the deficient bone formation and bone structure associated with glucose intolerance. Topics: Acid Phosphatase; Animals; Bone and Bones; Bone Resorption; Diabetes Mellitus, Type 2; Disease Models, Animal; Glucagon-Like Peptide 1; Glucose; Insulin; Insulin Resistance; Isoenzymes; Male; Osteocalcin; Osteoprotegerin; Parathyroid Hormone; Peptide Fragments; RANK Ligand; Rats; Rats, Wistar; Tartrate-Resistant Acid Phosphatase | 2009 |
Circadian rhythms of GIP and GLP1 in glucose-tolerant and in type 2 diabetic patients after biliopancreatic diversion.
We tested the hypothesis that the reversibility of insulin resistance and diabetes observed after biliopancreatic diversion (BPD) is related to changes in circadian rhythms of gastrointestinal hormones.. Ten morbidly obese participants, five with normal glucose tolerance (NGT) and five with type 2 diabetes, were studied before and within 2 weeks after BPD. Within-day variations in glucose-dependent insulinotropic polypeptide (GIP) and glucagon-like peptide 1 (GLP1) levels were assessed using a single cosinor model. Insulin sensitivity was assessed by euglycaemic-hyperinsulinaemic clamp.. Basal GLP1 relative amplitude (amplitude/mesor x 100) was 25.82-4.06% in NGT; it increased to 41.38-4.32% after BPD but was unchanged in diabetic patients. GLP1 and GIP mesor were shifted in time after surgery in diabetic patients but not in NGT participants. After BPD, the GLP1 AUC significantly increased from 775 +/- 94 to 846 +/- 161 pmol l(-1) min in NGT, whereas GIP AUC decreased significantly from 1,373 +/- 565 to 513 +/- 186 pmol l(-1) min in diabetic patients. Two-way ANOVA showed a strong influence of BPD on both GIP (p = 0.010) and GLP1 AUCs (p = 0.033), which was potentiated by the presence of diabetes, particularly for GIP (BPD x diabetes, p = 0.003). Insulin sensitivity was markedly improved (p < 0.01) in NGT (from 9.14 +/- 3.63 to 36.04 +/- 8.55 micromol [kg fat-free mass](-1) min(-1)) and diabetic patients (from 9.49 +/- 3.56 to 38.57 +/- 4.62 micromol [kg fat-free mass](-1) min(-1)).. An incretin circadian rhythm was shown for the first time in morbid obesity. The effect of BPD on the 24 h pattern of incretin differed between NGT and diabetic patients. GLP1 secretion impairment was reversed in NGT and could not be overcome by surgery in diabetes. On the other hand, GIP secretion was blunted after the operation only in diabetic patients, suggesting a role in insulin resistance and diabetes. Topics: Adipose Tissue; Adult; Biliopancreatic Diversion; Blood Glucose; Body Mass Index; Circadian Rhythm; Diabetes Mellitus, Type 2; Gastric Inhibitory Polypeptide; Glucagon-Like Peptide 1; Glucose Tolerance Test; Glycated Hemoglobin; Humans; Incretins; Insulin; Insulin Resistance; Middle Aged; Obesity, Morbid | 2009 |
Miglitol induces prolonged and enhanced glucagon-like peptide-1 and reduced gastric inhibitory polypeptide responses after ingestion of a mixed meal in Japanese Type 2 diabetic patients.
Topics: 1-Deoxynojirimycin; Asian People; Blood Glucose; Diabetes Mellitus, Type 2; Dietary Carbohydrates; Dietary Fats; Dietary Proteins; Gastric Inhibitory Polypeptide; Glucagon-Like Peptide 1; Humans; Hypoglycemic Agents; Insulin; Postprandial Period | 2009 |
The T allele of rs7903146 TCF7L2 is associated with impaired insulinotropic action of incretin hormones, reduced 24 h profiles of plasma insulin and glucagon, and increased hepatic glucose production in young healthy men.
We studied the physiological, metabolic and hormonal mechanisms underlying the elevated risk of type 2 diabetes in carriers of TCF7L2 gene.. We undertook genotyping of 81 healthy young Danish men for rs7903146 of TCF7L2 and carried out various beta cell tests including: 24 h glucose, insulin and glucagon profiles; OGTT; mixed meal test; IVGTT; hyperglycaemic clamp with co-infusion of glucagon-like peptide (GLP)-1 or glucose-dependent insulinotropic polypeptide (GIP); and a euglycaemic-hyperinsulinaemic clamp combined with glucose tracer infusion to study hepatic and peripheral insulin action.. Carriers of the T allele were characterised by reduced 24 h insulin concentrations (p < 0.05) and reduced insulin secretion relative to glucose during a mixed meal test (beta index: p < 0.003), but not during an IVGTT. This was further supported by reduced late-phase insulinotropic action of GLP-1 (p = 0.03) and GIP (p = 0.07) during a 7 mmol/l hyperglycaemic clamp. Secretion of GLP-1 and GIP during the mixed meal test was normal. Despite elevated hepatic glucose production, carriers of the T allele had significantly reduced 24 h glucagon concentrations (p < 0.02) suggesting altered alpha cell function.. Elevated hepatic glucose production and reduced insulinotropic effect of incretin hormones contribute to an increased risk of type 2 diabetes in carriers of the rs7903146 risk T allele of TCF7L2. Topics: Adolescent; Alleles; Blood Glucose; Diabetes Mellitus, Type 2; Genotype; Glucagon-Like Peptide 1; Glucose Clamp Technique; Glucose Tolerance Test; Glutaminase; Humans; Hyperinsulinism; Incretins; Insulin; Intracellular Signaling Peptides and Proteins; Liver; Male; Risk Factors; TCF Transcription Factors; Transcription Factor 7-Like 2 Protein; Tritium; Young Adult | 2009 |
GLP-1 receptor agonists: targeting both hyperglycaemia and disease processes in diabetes.
Topics: Blood Glucose; Diabetes Mellitus, Type 2; Dipeptidyl Peptidase 4; Exenatide; Glucagon-Like Peptide 1; Glucagon-Like Peptide-1 Receptor; Glycated Hemoglobin; Humans; Hypoglycemic Agents; Incretins; Liraglutide; Peptides; Receptors, Glucagon; Venoms | 2009 |
A common genetic variant in WFS1 determines impaired glucagon-like peptide-1-induced insulin secretion.
WFS1 type 2 diabetes risk variants appear to be associated with impaired beta cell function, although it is unclear whether insulin secretion is affected directly or secondarily via alteration of insulin sensitivity. We aimed to investigate the effect of a common WFS1 single-nucleotide polymorphism on several aspects of insulin secretion.. A total of 1,578 non-diabetic individuals (534 men and 1,044 women, aged 40 +/- 13 years, BMI 28.9 +/- 8.2 kg/m(2) [mean +/- SD]) at increased risk of type 2 diabetes were genotyped for rs10010131 within the WFS1 gene. All participants underwent an OGTT (and a subset additionally an IVGTT [n = 319]) and a hyperglycaemic clamp combined with glucagon-like peptide-1 (GLP-1) and arginine stimuli (n = 102).. rs10010131 was associated with reduced OGTT-derived insulin secretion (p = 0.03). In contrast, insulin secretion induced by an i.v. glucose challenge in the IVGTT and hyperglycaemic clamp was not different between the genotypes. GLP-1 infusion combined with a hyperglycaemic clamp showed a significant reduction of the insulin secretion rate during the first and second phases of GLP-1-induced insulin secretion in carriers of the risk allele (reduction of 36% and 26%, respectively; p = 0.007 and p = 0.04, respectively).. A common genetic variant in WFS1 specifically impairs GLP-1-induced insulin secretion independently of insulin sensitivity. This defect might explain the impaired insulin secretion in carriers of the risk allele and confer the increased risk of type 2 diabetes. Topics: Adult; Diabetes Mellitus, Type 2; Female; Genotype; Glucagon-Like Peptide 1; Glucose Clamp Technique; Glucose Tolerance Test; Humans; Insulin; Insulin Secretion; Islets of Langerhans; Male; Membrane Proteins; Middle Aged; Polymorphism, Single Nucleotide | 2009 |
Diabetes treatment and measures of glycemia.
Topics: Blood Glucose; Clinical Trials as Topic; Diabetes Mellitus, Type 2; Diabetes, Gestational; Exenatide; Female; Glucagon-Like Peptide 1; Glycated Hemoglobin; Humans; Hypoglycemic Agents; Insulin; Insulin Secretion; Liraglutide; Peptides; Pregnancy; Venoms | 2009 |
Combining a dipeptidyl peptidase-4 inhibitor, alogliptin, with pioglitazone improves glycaemic control, lipid profiles and beta-cell function in db/db mice.
Alogliptin, a highly selective dipeptidyl peptidase-4 (DPP-4) inhibitor, enhances incretin action and pioglitazone enhances hepatic and peripheral insulin actions. Here, we have evaluated the effects of combining these agents in diabetic mice.. Effects of short-term treatment with alogliptin alone (0.01%-0.1% in diet), and chronic combination treatment with alogliptin (0.03% in diet) and pioglitazone (0.0075% in diet) were evaluated in db/db mice exhibiting early stages of diabetes.. Alogliptin inhibited plasma DPP-4 activity up to 84% and increased plasma active glucagon-like peptide-1 by 4.4- to 4.9-fold. Unexpectedly, alogliptin alone lacked clear efficacy for improving glucose levels. However, alogliptin in combination with pioglitazone clearly enhanced the effects of pioglitazone alone. After 3-4 weeks of treatment, combination treatment increased plasma insulin by 3.8-fold, decreased plasma glucagon by 41%, both of which were greater than each drug alone, and increased plasma adiponectin by 2.4-fold. In addition, combination treatment decreased glycosylated haemoglobin by 2.2%, plasma glucose by 52%, plasma triglycerides by 77% and non-esterified fatty acids by 48%, all of which were greater than each drug alone. Combination treatment also increased expression of insulin and pancreatic and duodenal homeobox 1 (PDX1), maintained normal beta-cell/alpha-cell distribution in islets and restored pancreatic insulin content to levels comparable to non-diabetic mice.. These results indicate that combination treatment with alogliptin and pioglitazone at an early stage of diabetes improved metabolic profiles and indices that measure beta-cell function, and maintained islet structure in db/db mice, compared with either alogliptin or pioglitazone monotherapy. Topics: Adiponectin; Animals; Blood Glucose; Body Weight; Cell Degranulation; Diabetes Mellitus, Type 2; Dipeptidyl Peptidase 4; Dipeptidyl-Peptidase IV Inhibitors; Drug Therapy, Combination; Eating; Glucagon; Glucagon-Like Peptide 1; Hypoglycemic Agents; Insulin; Insulin-Secreting Cells; Lipids; Male; Mice; Pioglitazone; Piperidines; Thiazolidinediones; Uracil | 2009 |
Protease-resistant glucagon like peptide-1 analogs with long-term anti-diabetes type 2 activity.
Topics: Biological Availability; Diabetes Mellitus, Type 2; Glucagon-Like Peptide 1; Humans; Peptide Hydrolases | 2009 |
A novel dipeptidyl peptidase-4 inhibitor, alogliptin (SYR-322), is effective in diabetic rats with sulfonylurea-induced secondary failure.
Loss of efficacy over time or secondary failure occurs somewhat often and remains a major concern of sulfonylurea (SU) therapy. In this study, we investigated the benefits of alogliptin, an oral, potent and highly selective dipeptidyl peptidase-4 (DPP-4) inhibitor, in a rat model exhibiting SU secondary failure.. Neonatally streptozotocin-induced diabetic rats (N-STZ-1.5 rats), a non-obese model of type 2 diabetes, were used in these studies. The effects of alogliptin on DPP-4 activity and glucagon-like peptide 1 (GLP-1) concentration were determined by measuring their levels in plasma. In addition, the effects of alogliptin on an oral glucose tolerance test were investigated by using an SU secondary failure model.. Alogliptin dose dependently suppressed plasma DPP-4 activity leading to an increase in the plasma active form of GLP-1 and improved glucose excursion in N-STZ-1.5 rats. Repeated administration of glibenclamide resulted in unresponsiveness or loss of glucose tolerance typical of secondary failure. In these rats, alogliptin exhibited significant improvement of glucose excursion with significant increase in insulin secretion. By contrast, glibenclamide and nateglinide had no effect on the glucose tolerance of these rats.. The above findings suggest that alogliptin was effective at improving glucose tolerance and therefore overcoming SU induced secondary failure in N-STZ-1.5 rats. Topics: Animals; Blood Glucose; Diabetes Mellitus, Experimental; Diabetes Mellitus, Type 2; Dipeptidyl Peptidase 4; Dipeptidyl-Peptidase IV Inhibitors; Glucagon-Like Peptide 1; Hypoglycemic Agents; Male; Piperidines; Rats; Sulfonylurea Compounds; Treatment Failure; Uracil | 2009 |
[New and older pharmaceuticals influencing insulin secretion].
The author briefly recapitulates the physiology of insulin secretion and pathophysiology with type II diabetes mellitus. Besides sulfonylurea secretagogues and glinides practically used in the long term, the author points out new possibilities of influencing insulin secretion by way of incretin mimetics and gliptins. Topics: Diabetes Mellitus, Type 2; Glucagon-Like Peptide 1; Glucose; Humans; Incretins; Insulin; Insulin Secretion; Sulfonylurea Compounds | 2009 |
From bariatric to metabolic surgery in non-obese subjects: time for some caution.
Severe obesity is associated with type 2 diabetes mellitus, and both resolve with weight loss after bariatric operations. Intestinal hormones have been identified which are stimulated by rapid nutrient delivery to the lower small bowel after certain weight-loss operations. These incretins stimulate secretion and hypertrophy of the pancreatic beta cells. Surgical procedures are now being performed to treat diabetes in adults of lesser weight, and the importance of ruling out latent autoimmune diabetes in the adult (a variety of type 1) is suggested, before experimenting with these procedures. Topics: Adult; Bariatric Surgery; Body Mass Index; C-Peptide; Diabetes Mellitus, Type 1; Diabetes Mellitus, Type 2; Glucagon-Like Peptide 1; Humans; Insulin Resistance; Obesity; Weight Loss | 2009 |
Antihyperglycaemic medication modifies factors of postprandial satiety in type 2 diabetes.
Type 2 diabetes is characterized by hyperglycaemia, delayed gastric emptying and a blunted response of gut hormones during feeding that may modulate satiety. We hypothesized that it is associated with more hunger when treated by medication.. We studied nine type 2 diabetic men (A1C: 6.7+/-0.3%, waist circumference: 104+/-4 cm) after an overnight fast, during 5 h in response to a 2.88 MJ breakfast, twice, in a crossover design, with or without antihyperglycaemic agents. Satiety ratings, thermic effect of meal, gastric emptying, plasma concentrations of gut peptides, leptin, insulin and substrates and intake from a subsequent buffet were determined.. With medication, fasting and postprandial plasma glucose levels were lower but area under the curve (AUC) did not vary vs. without medication. Gastric emptying was shortened, branched chain amino acids (BCAA) AUC and thermic effect were lower, and postprandial glucagon-like peptide-1 (GLP-1) and peptide tyrosine tyrosine (PYY3-36) were maintained at higher levels beyond 4 h. Correlations were significant between duration of diabetes and fasting ghrelin (r=0.779, p=0.013) and peak insulin (r=-0.769, p=0.016), 5-h postmeal ghrelin and peak glucose (r=0.822, p=0.007), 5-h glucose and GLP-1 (r=-0.788, p=0.012), and 5-h hunger scores and energy intake at buffet (r=0.828, p=0.006). Without medication, fullness scores correlated with BCAA levels. Visual analogue scale scores, ghrelin and leptin levels did not differ between studies.. The decrease in factors associated with postprandial satiety with treatment is counterbalanced by higher GLP-1 and PYY3-36. Medication may normalize the link between perception of hunger and subsequent food intake. Topics: Aged; Amino Acids; Area Under Curve; Blood Glucose; Cross-Over Studies; Diabetes Mellitus, Type 2; Dipeptides; Fasting; Gastric Emptying; Glucagon-Like Peptide 1; Glyburide; Humans; Hunger; Hypoglycemic Agents; Insulin; Leptin; Male; Metformin; Middle Aged; Postprandial Period; Satiation; Thiazolidinediones | 2009 |
GLP-1 receptor agonists for type 2 diabetes.
Topics: Diabetes Mellitus, Type 2; Exenatide; Glucagon-Like Peptide 1; Humans; Hypoglycemic Agents; Liraglutide; Multicenter Studies as Topic; Peptides; Randomized Controlled Trials as Topic; Safety; Treatment Outcome; Venoms | 2009 |
Constitutive increase in active GLP-1 levels by the DPP4 inhibitor ASP4000 on a new meal tolerance test in Zucker fatty rats.
Glucagon-like peptide-1 (GLP-1), an incretin hormone, is essential for the regulation of insulin secretion and glucose homeostasis. GLP-1 is rapidly degraded by dipeptidyl peptidase 4 (DPP4); therefore, DPP4 inhibitors are considered to be a novel class of oral antihyperglycemic agents. These agents are currently under development as treatments for type 2 diabetes. Normally, oral glucose tolerance tests are used for evalating glucose-lowering efficacy, but the augmentation of active GLP-1 via DPP4 inhibition in this test was transient. It has been proposed that the secretion of GLP-1 is regulated by the rate of entry of nutrients into the small intestine; therefore, we have established the new meal tolerance test method using solid diet. This model allows for the continuous monitoring of active GLP-1 secretion after food intake. ASP4000 is an orally effective inhibitor of DPP4 that greatly augments meal-stimulated circulating levels of active GLP-1 constitutively and improves hyperglycemia. Acarbose improved glucose tolerance in the test to a degree similar to that of the DPP4 inhibitor. Our new meal tolerance test is useful for evaluating postprandial hyperglycemia and could be an excellent model for studying the secretion of active GLP-1 via the inhibition of DPP4. Topics: Animals; Azabicyclo Compounds; Blood Glucose; Diabetes Mellitus, Type 2; Dipeptidyl-Peptidase IV Inhibitors; Glucagon-Like Peptide 1; Hyperglycemia; Hypoglycemic Agents; Insulin; Male; Models, Animal; Rats; Rats, Zucker | 2009 |
Poly-GLP-1, a novel long-lasting glucagon-like peptide-1 polymer, ameliorates hyperglycaemia by improving insulin sensitivity and increasing pancreatic beta-cell proliferation.
The clinical value of glucagon-like peptide-1 (GLP-1) is restricted because of its short half-life. To overcome this limitation, a new polymer of GLP-1 was developed by prodrug strategy, termed Poly-GLP-1, and its pharmacological properties were investigated.. The in vitro release kinetics of GLP-1 from Poly-GLP-1 was analysed by Western blot. Plasma GLP-1 levels following a single administration of Poly-GLP-1 were determined by enzyme-linked immunosorbent assay. The in vitro effects of Poly-GLP-1 were evaluated using isolated pancreatic islets. The acute effects on glycaemic control and food intake were investigated in C57BL/6J mice s.c. administered with Poly-GLP-1. The chronic effects of Poly-GLP-1 on glycaemic control were further assessed in C57BL/6J and db/db mice treated twice daily for 6 weeks.. Pro-GLP-1 dose dependently increased insulin secretion and decreased glucose, but did not exhibit the insulinotropic action in isolated pancreatic islets without plasma. The glucose-lowering actions of Poly-GLP-1 (3 nmol/kg) remained no less than 12 h after a single injection. Poly-GLP-1 caused a durable restoration of glycaemic control, food intake and body weight gain in db/db mice following 6-week administration. The chronic treatment with Poly-GLP-1 improved glucose tolerance and insulin sensitivity and increased beta-cell mass and proliferation in db/db mice. There was little effect on normal mice treated in the same manner.. Our results indicated that Poly-GLP-1, a novel GLP-1 polymer, has long-lasting and potent effects on glycaemic control in vivo, and these beneficial effects may be because of improvement of insulin sensitivity and promotion of islet growth and function. Topics: Animals; Blood Glucose; Blotting, Western; Cell Proliferation; Diabetes Mellitus, Type 2; Dose-Response Relationship, Drug; Drug Evaluation, Preclinical; Enzyme-Linked Immunosorbent Assay; Glucagon-Like Peptide 1; Hyperglycemia; Hypoglycemic Agents; Insulin; Insulin Resistance; Insulin Secretion; Insulin-Secreting Cells; Mice; Mice, Inbred BALB C; Polymers; Prodrugs | 2009 |
[Role and indication of GLP-1 analogues in the treatment of type 2 diabetes].
Available therapies for type 2 diabetes are not always satisfactory because they do not address the problems of overweight/obesity and the progressive deterioration of cell function. GLP-1 analogues or agonists of the GLP-1 receptor are a new therapeutic option which offer promises; they indeed improve glycemic control, decrease weight by 2-3 kg/year and may stabilize or improve cell function by favoring cell proliferation and inhibiting apoptosis. Their use in patients who are not sufficiently controlled by metformin and sulfonylurea compares favourably to insulin treatment. Topics: Diabetes Mellitus, Type 2; Exenatide; Glucagon-Like Peptide 1; Humans; Hypoglycemic Agents; Peptides; Venoms | 2009 |
Glucagon-like peptide 1/glucagon receptor dual agonism reverses obesity in mice.
Oxyntomodulin (OXM) is a glucagon-like peptide 1 (GLP-1) receptor (GLP1R)/glucagon receptor (GCGR) dual agonist peptide that reduces body weight in obese subjects through increased energy expenditure and decreased energy intake. The metabolic effects of OXM have been attributed primarily to GLP1R agonism. We examined whether a long acting GLP1R/GCGR dual agonist peptide exerts metabolic effects in diet-induced obese mice that are distinct from those obtained with a GLP1R-selective agonist.. We developed a protease-resistant dual GLP1R/GCGR agonist, DualAG, and a corresponding GLP1R-selective agonist, GLPAG, matched for GLP1R agonist potency and pharmacokinetics. The metabolic effects of these two peptides with respect to weight loss, caloric reduction, glucose control, and lipid lowering, were compared upon chronic dosing in diet-induced obese (DIO) mice. Acute studies in DIO mice revealed metabolic pathways that were modulated independent of weight loss. Studies in Glp1r(-/-) and Gcgr(-/-) mice enabled delineation of the contribution of GLP1R versus GCGR activation to the pharmacology of DualAG.. Peptide DualAG exhibits superior weight loss, lipid-lowering activity, and antihyperglycemic efficacy comparable to GLPAG. Improvements in plasma metabolic parameters including insulin, leptin, and adiponectin were more pronounced upon chronic treatment with DualAG than with GLPAG. Dual receptor agonism also increased fatty acid oxidation and reduced hepatic steatosis in DIO mice. The antiobesity effects of DualAG require activation of both GLP1R and GCGR.. Sustained GLP1R/GCGR dual agonism reverses obesity in DIO mice and is a novel therapeutic approach to the treatment of obesity. Topics: Amino Acid Sequence; Animals; Body Weight; CHO Cells; Cricetinae; Cricetulus; Diabetes Mellitus, Type 2; Dietary Fats; Energy Intake; Glucagon-Like Peptide 1; Glucagon-Like Peptide-1 Receptor; Injections, Subcutaneous; Insulin; Mice; Mice, Inbred C57BL; Molecular Sequence Data; Obesity; Oxyntomodulin; Receptors, Glucagon; Reverse Transcriptase Polymerase Chain Reaction; Weight Loss | 2009 |
Pancreatic function of spontaneously diabetic torii rats in pre-diabetic stage.
The Spontaneously Diabetic Torii (SDT) rat is a new model for non-obese type 2 diabetes. In the present study, we investigated changes in insulin secretion from the pancreas of male SDT rats aged 8, 16, and 24 weeks in order to analyze pancreatic function. An analysis of glucose-stimulated insulin secretion (GSIS) in isolated islets showed a marked reduction in insulin secretion in pre-diabetic 16-week-old SDT rats. When the islets were treated with tolbutamide or glucagon-like peptide-1 (7-36) amide (tGLP-1) in the presence of 11.2 mM glucose, however, insulin levels were restored to levels of normal rats. In vivo study, SDT rats exhibited a marked reduction in GSIS from 16 weeks of age. However, tolbutamide or JTP-76209, which is a novel dipeptidyl peptidase IV (DPP IV) inhibitor, increased insulin release after glucose loading and improved glucose tolerance. A marked reduction in GSIS was observed in pre-diabetic SDT rats and the reduction was improved by tolbutamide, tGLP-1, and the DPP IV inhibitor. Therefore, we concluded that the SDT rat is useful, as a model of non-obese insulin secretory disorder, for the analysis of the onset of type 2 diabetes and the development of antidiabetic agents. Topics: Animals; Arginine; Benzoates; Body Weight; Diabetes Mellitus, Type 2; Dipeptidyl-Peptidase IV Inhibitors; Disease Models, Animal; Enzyme Inhibitors; Glucagon; Glucagon-Like Peptide 1; Glucose Tolerance Test; Hypoglycemic Agents; Insulin; Insulin Secretion; Islets of Langerhans; Male; Obesity; Organ Culture Techniques; Pancreas; Peptide Fragments; Rats; Rats, Sprague-Dawley; Tolbutamide | 2009 |
Preliminary report: genetic variation within the GPBAR1 gene is not associated with metabolic traits in white subjects at an increased risk for type 2 diabetes mellitus.
Bile acids are signaling molecules with important endocrine functions. Some of these, including the induction of energy expenditure in brown adipose tissue and skeletal muscle as well as the stimulation of glucagon-like peptide-1 (GLP-1) production in enteroendocrine L-cells, are mediated by the G-protein-coupled bile acid receptor 1 (GPBAR1). Therefore, we investigated in a cohort of white subjects at increased risk for type 2 diabetes mellitus whether a genetic variation within the GPBAR1 gene contributes to prediabetic phenotypes, such as disproportionate fat distribution, insulin resistance, or beta-cell dysfunction. We genotyped 1576 subjects (1043 women, 533 men) for the single nucleotide polymorphism rs3731859 in the GPBAR1 gene. All subjects underwent an oral glucose tolerance test; a subset additionally had a hyperinsulinemic-euglycemic clamp. Regional fat distribution, ectopic hepatic and intramyocellular lipids were determined by magnetic resonance techniques. Peak aerobic capacity, a surrogate parameter for oxidative capacity of skeletal muscle, was measured by an incremental exercise test on a motorized treadmill. Total GLP-1 and gastric inhibitory peptide levels were determined by radioimmunoassay. After appropriate adjustment and Bonferroni correction for multiple comparisons, rs3731859 was not significantly associated with regional or ectopic fat distribution, peak aerobic capacity, levels of incretins, insulin sensitivity, or indices of insulin secretion. Nominal associations were found between rs3731859 and body mass index, waist circumference, fasting GLP-1 levels, and intramyocellular lipids in the soleus muscle (P = .02, P = .02, P = .05, and P = .03, respectively). Our data suggest that a common genetic variation within the GPBAR1 gene may not play a major role in the development of prediabetic phenotypes in our white population. Topics: Adipose Tissue; Cohort Studies; Diabetes Mellitus, Type 2; Exercise Test; Female; Genetic Variation; Genotype; Glucagon-Like Peptide 1; Glucose Tolerance Test; Humans; Insulin Resistance; Lipid Metabolism; Magnetic Resonance Imaging; Male; Muscle, Skeletal; Polymorphism, Single Nucleotide; Receptors, G-Protein-Coupled; Risk Factors; White People | 2009 |
Glucagon-like peptide-1 agonists protect pancreatic beta-cells from lipotoxic endoplasmic reticulum stress through upregulation of BiP and JunB.
Chronic exposure of pancreatic beta-cells to saturated free fatty acids (FFAs) causes endoplasmic reticulum (ER) stress and apoptosis and may contribute to beta-cell loss in type 2 diabetes. Here, we evaluated the molecular mechanisms involved in the protection of beta-cells from lipotoxic ER stress by glucagon-like peptide (GLP)-1 agonists utilized in the treatment of type 2 diabetes.. INS-1E or fluorescence-activated cell sorter-purified primary rat beta-cells were exposed to oleate or palmitate with or without the GLP-1 agonist exendin-4 or forskolin. Cyclopiazonic acid was used as a synthetic ER stressor, while the activating transcription factor 4-C/EBP homologous protein branch was selectively activated with salubrinal. The ER stress signaling pathways modulated by GLP-1 agonists were studied by real-time PCR and Western blot. Knockdown by RNA interference was used to identify mediators of the antiapoptotic GLP-1 effects in the ER stress response and downstream mitochondrial cell death mechanisms.. Exendin-4 and forskolin protected beta-cells against FFAs via the induction of the ER chaperone BiP and the antiapoptotic protein JunB that mediate beta-cell survival under lipotoxic conditions. On the other hand, exendin-4 and forskolin protected against synthetic ER stressors by inactivating caspase 12 and upregulating Bcl-2 and X-chromosome-linked inhibitor of apoptosis protein that inhibit mitochondrial apoptosis.. These observations suggest that GLP-1 agonists increase in a context-dependent way the beta-cell defense mechanisms against different pathways involved in ER stress-induced apoptosis. The identification of the pathways modulated by GLP-1 agonists allows for targeted approaches to alleviate beta-cell ER stress in diabetes. Topics: Animals; Antigens, Differentiation; Apoptosis; Blotting, Western; Cell Survival; Colforsin; Diabetes Mellitus, Type 2; DNA-Binding Proteins; Endoplasmic Reticulum; Exenatide; Glucagon-Like Peptide 1; Glucagon-Like Peptide-1 Receptor; Heat-Shock Proteins; Hypoglycemic Agents; Insulin-Secreting Cells; Lipid Metabolism; Male; Peptides; Polymerase Chain Reaction; Proto-Oncogene Proteins; Proto-Oncogene Proteins c-jun; Rats; Rats, Wistar; Receptors, Glucagon; Regulatory Factor X Transcription Factors; RNA Interference; Transcription Factors; Up-Regulation; Venoms | 2009 |
Mechanism of action of inhibitors of dipeptidyl-peptidase-4 (DPP-4).
Dipeptidyl-peptidase IV (DPP-4) inhibitors inhibit the degradation of the incretins, glucagon-like peptide-1 (GLP-1) and glucose-dependent insulinotropic peptide (GIP). The first available DPP-4 inhibitors are sitagliptin and vildagliptin. These compounds are orally active and have been shown to be efficacious and well tolerated. Two additional DPP-4 inhibitors are under review, and there are several others in clinical development. This article gives an overview on the mechanism of action of DPP-4 inhibitors and focuses on their development and their important physiological actions with regard to the treatment of type 2 diabetes. Topics: Adamantane; Animals; Blood Glucose; Diabetes Mellitus, Type 2; Dipeptidyl Peptidase 4; Dipeptidyl-Peptidase IV Inhibitors; Glucagon; Glucagon-Like Peptide 1; Humans; Hypoglycemic Agents; Incretins; Insulin; Nitriles; Pyrazines; Pyrrolidines; Sitagliptin Phosphate; Triazoles; Vildagliptin | 2009 |
Inhibition of DPP-4 with sitagliptin improves glycemic control and restores islet cell mass and function in a rodent model of type 2 diabetes.
Inhibition of dipeptidyl peptidase-4 (DPP-4) activity has been shown to improve glycemic control in patients with type 2 diabetes by prolonging and potentiating the actions of incretin hormones. This study is designed to determine the effects of the DPP-4 inhibitor sitagliptin on improving islet function in a mouse model of insulin resistance and insulin secretion defects. ICR mice were pre-treated with high fat diet and a low dose of streptozotocin to induce insulin resistance and impaired insulin secretion, respectively. Diabetic mice were treated with sitagliptin or the sulfonylurea agent glipizide as admixture to high fat diet for ten weeks. Sustained reduction of blood glucose, HbA(1c), circulating glucagon and improvement in oral glucose tolerance were observed in mice treated with sitagliptin. In contrast, glipizide improved glycemic control only during the early weeks and to a lesser degree compared to sitagliptin, and had no effect on circulating glucagon levels or glucose tolerance. The improvement in glycemic control in sitagliptin-treated mice was associated with a significant increase in glucose-dependent insulin secretion in both perfused pancreas and isolated islets. Importantly, in contrast to the lack of effect by glipizide, sitagliptin significantly restored beta and alpha cell mass as well as alpha/beta cell ratio. These data indicate that DPP-4 inhibition by sitagliptin provided better overall improvement of glycemic control compared to glipizide in the high fat diet/streptozotocin induced diabetic mouse model. The ability of sitagliptin to enhance islet cell function may offer insight into the potential for disease modification. Topics: Animals; Blood Glucose; Diabetes Mellitus, Experimental; Diabetes Mellitus, Type 2; Dietary Fats; Dipeptidyl Peptidase 4; Dipeptidyl-Peptidase IV Inhibitors; Glipizide; Glucagon; Glucagon-Like Peptide 1; Glycated Hemoglobin; Hypoglycemic Agents; Insulin; Insulin Secretion; Islets of Langerhans; Ki-67 Antigen; Lipids; Liver; Male; Mice; Mice, Inbred ICR; Organ Size; Pyrazines; Sitagliptin Phosphate; Triazoles; Triglycerides | 2009 |
Saxagliptin.
Saxagliptin and its active metabolite M2 are dipeptidyl peptidase-4 inhibitors that improve glycaemic control by preventing the inactivation of the incretin hormones glucagon-like peptide-1 (GLP-1) and glucose-dependent insulinotropic polypeptide. This increases GLP-1 levels, stimulates insulin secretion and reduces postprandial glucagon and glucose levels. In well designed, 24-week trials in treatment-naive patients with type 2 diabetes mellitus, monotherapy with oral saxagliptin 2.5 or 5 mg once daily significantly improved glycaemic control, as measured by mean glycosylated haemoglobin (HbA(1c)) levels, relative to placebo. In large, well designed, 24-week trials, combination therapy with saxagliptin 5 mg once daily plus metformin significantly improved HbA(1c) levels relative to single-agent saxagliptin or metformin in treatment-naive patients; in treatment-experienced patients with inadequate glycaemic control, the addition of saxagliptin 2.5 or 5 mg once daily to metformin, glyburide or a thiazolidinedione, significantly improved HbA(1c) levels relative to continued use of existing monotherapy. Saxagliptin as monotherapy or in combination with other oral antihyperglycaemics was generally well tolerated, with most adverse events being of mild to moderate severity. In clinical trials, the incidence of hypoglycaemic events in patients receiving saxagliptin was generally similar to that in patients receiving placebo or other oral antihyperglycaemic agents. Saxagliptin therapy was not associated with an increased risk of cardiovascular events according to pooled data from eight clinical trials. Saxagliptin generally had a weight-neutral effect. Topics: Blood Glucose; Diabetes Mellitus, Type 2; Dipeptidyl-Peptidase IV Inhibitors; Drug Therapy, Combination; Glucagon-Like Peptide 1; Glyburide; Humans; Metformin; Randomized Controlled Trials as Topic; Treatment Outcome | 2009 |
Adverse events in diabetes drug trial.
Topics: Data Interpretation, Statistical; Diabetes Mellitus, Type 2; Exenatide; Glucagon-Like Peptide 1; Humans; Liraglutide; Peptides; Randomized Controlled Trials as Topic; Research Design; Safety; Treatment Outcome; Venoms | 2009 |
Activation of sodium-glucose cotransporter 1 ameliorates hyperglycemia by mediating incretin secretion in mice.
Glucose ingestion stimulates the secretion of the incretin hormones, glucose-dependent insulinotropic peptide (GIP) and glucagon-like peptide-1 (GLP-1). Despite the critical role of incretins in glucose homeostasis, the mechanism of glucose-induced incretin secretion has not been established. We investigated the underlying mechanism of glucose-induced incretin secretion in vivo in mice. Injection of glucose at 1 g/kg in the upper intestine significantly increased plasma GIP and GLP-1 levels, whereas injection of glucose in the colon did not increase GIP or GLP-1 levels. This finding indicates that the glucose sensor for glucose-induced incretin secretion is in the upper intestine. Coadministration of a sodium-glucose cotransporter-1 (SGLT1) inhibitor, phloridzin, with glucose in the upper intestine blocked glucose absorption and glucose-induced incretin secretion. alpha-methyl-d-glucopyranoside (MDG), an SGLT1 substrate that is a nonmetabolizable sugar, significantly increased plasma GIP and GLP-1 levels, whereas phloridzin blocked these increases, indicating that concomitant transport of sodium ions and glucose (substrate) via SGLT1 itself triggers incretin secretion without the need for subsequent glucose metabolism. Interestingly, oral administration of MDG significantly increased plasma GIP, GLP-1, and insulin levels and reduced blood glucose levels during an intraperitoneal glucose tolerance test. Furthermore, chronic MDG treatment in drinking water (3%) for 13 days reduced blood glucose levels after a 2-h fast and in an oral glucose tolerance test in diabetic db/db mice. Our findings indicate that SGLT1 serves as the intestinal glucose sensor for glucose-induced incretin secretion and that a noncalorigenic SGLT1 substrate ameliorates hyperglycemia by stimulating incretin secretion. Topics: Animals; Blood Glucose; Diabetes Mellitus, Type 2; Gastric Inhibitory Polypeptide; Glucagon-Like Peptide 1; Glucose; Glucose Tolerance Test; Hyperglycemia; Intestine, Large; Male; Methylglucosides; Mice; Mice, Inbred C57BL; Phlorhizin; Random Allocation; Reverse Transcriptase Polymerase Chain Reaction; RNA, Messenger; Sodium-Glucose Transporter 1 | 2009 |
Age dependence of glucose tolerance in adult KK-Ay mice, a model of non-insulin dependent diabetes mellitus.
Yellow KK mice carrying the 'yellow obese' gene Ay are a well established polygenic model for human non-insulin dependent diabetes mellitus. These animals develop marked adiposity and decreased glucose tolerance relative to their control littermates, KK mice. The authors monitored glucose tolerance in KK-Ay mice over time and observed a significant (P Topics: Age Factors; Amyloid; Animals; Diabetes Mellitus, Type 2; Disease Models, Animal; Glucagon; Glucagon-Like Peptide 1; Glucose; Insulin; Islet Amyloid Polypeptide; Leptin; Male; Mice; Mice, Inbred ICR | 2009 |
The clinical challenges of managing type 2 diabetes and the potential of GLP-1-based therapies.
Topics: Diabetes Mellitus, Type 2; Disease Progression; Glucagon-Like Peptide 1; Humans; Hypoglycemic Agents; Incretins | 2009 |
Discovery of 3-aryl-4-isoxazolecarboxamides as TGR5 receptor agonists.
A series of 3-aryl-4-isoxazolecarboxamides identified from a high-throughput screening campaign as novel, potent small molecule agonists of the human TGR5 G-protein coupled receptor is described. Subsequent optimization resulted in the rapid identification of potent exemplars 6 and 7 which demonstrated improved GLP-1 secretion in vivo via an intracolonic dose coadministered with glucose challenge in a canine model. These novel TGR5 receptor agonists are potentially useful therapeutics for metabolic disorders such as type II diabetes and its associated complications. Topics: Amides; Animals; Diabetes Mellitus, Type 2; Disease Models, Animal; Dogs; Glucagon-Like Peptide 1; Glucose; Humans; Isoxazoles; Rats; Receptors, G-Protein-Coupled | 2009 |
Liraglutide: a once-daily human glucagon-like peptide-1 analogue.
Topics: Animals; Apoptosis; Clinical Trials, Phase I as Topic; Clinical Trials, Phase II as Topic; Clinical Trials, Phase III as Topic; Diabetes Mellitus, Type 2; Glucagon-Like Peptide 1; Humans; Hypoglycemic Agents; Insulin-Secreting Cells; Liraglutide | 2009 |
The role of incretin-based therapies in the management of type 2 diabetes.
Type 2 diabetes (T2D) is associated with a greatly increased risk of cardiovascular disease. An increasing need for glucose-lowering treatments is emphasized by the almost inevitable failure of monotherapy and occurrence of weight gain. Recently, novel classes of drugs derived from the incretin system have been introduced into the management of T2D. Recent advances in the field of incretin-based therapies in the management of T2D were discussed at the 45th Annual Meeting of the European Association for the Study of Diabetes, held from September 29 until October 2, 2009, in Vienna, Austria. Topics: Animals; Blood Glucose; Cardiovascular Diseases; Diabetes Mellitus, Type 2; Dipeptidyl Peptidase 4; Dipeptidyl-Peptidase IV Inhibitors; Glucagon-Like Peptide 1; Humans; Hypoglycemic Agents; Incretins; Treatment Outcome | 2009 |
Does glucagon-like peptide-1 receptor agonist therapy add value in the treatment of type 2 diabetes? Focus on exenatide.
Type 2 diabetes (T2DM) is a heterogeneous syndrome, characterized by beta-cell failure in the setting of obesity-related insulin resistance. T2DM has a progressive course and is associated with a high cardiovascular disease (CVD) risk, regardless of the treatment used. The incretin hormones glucagon-like peptide (GLP)-1 and glucose-dependent insulinotropic polypeptide (GIP) are secreted in the gut upon meal ingestion and lower blood glucose by glucose-dependent stimulation of insulin secretion and production. Exogenously administered GLP-1 lowers postprandial glucose excursions by inhibiting glucagon secretion and delaying gastric emptying, improves beta-cell function, and promotes satiety and weight loss. Native GLP-1 is degraded rapidly by the ubiquitous enzyme dipeptidyl-peptidase (DPP)-4. Thus, injectable DPP-4-resistant GLP-1 receptor agonists (GLP-1RA) and oral DPP-4 inhibitors have been developed. Exenatide is the first GLP-1RA that became available for the treatment of T2DM patients. Exenatide has unique characteristics, as to date it is the only agent that addresses the multiple defects of the T2DM phenotype, including hyperglycaemia, islet-cell dysfunction, alimentary obesity, insulin resistance, hypertension and dyslipidaemia. In animals, exenatide also increased beta-cell mass. Long-term prospective studies in high-risk populations should address the potentially disease modifying effect of exenatide and its effect on CVD risk, in addition to its safety and tolerability. Topics: Diabetes Mellitus, Type 2; Exenatide; Glucagon; Glucagon-Like Peptide 1; Glucagon-Like Peptide-1 Receptor; Humans; Hypoglycemic Agents; Incretins; Insulin-Secreting Cells; Peptides; Phenotype; Receptors, Glucagon; Venoms | 2009 |
Diabetes care targets in older persons.
The increasing proportions of older persons accounting for global populations, and the implications for increasing rates of chronic diseases such as type 2 diabetes mellitus, continue to be a cause of concern for clinicians. Considering that older persons are a very heterogeneous group of individuals, the management of type 2 diabetes is particularly challenging. Once type 2 diabetes is diagnosed, the principles of its management are similar to those in younger patients, but with special considerations linked to the increased prevalence of comorbidities and relative inability to tolerate adverse effects of medication and hypoglycemia. In addition, there are clinical aspects complicating diabetes care in the elderly including cognitive disorders, physical disability and geriatric syndromes, such as frailty. Available anti-diabetic oral drugs include insulin secretagogues (meglitinides and sulfonylureas), biguanides (metformin) alpha-glucosidase inhibitors, thiazolidinediones (TZDs) and newly introduced glucagon-like peptide-1 (GLP-1) analogues and inhibitors of GLP-1 degrading enzyme dipeptidyl peptidase-4 (DPP-4). Unfortunately, as type 2 diabetes progresses in older persons, polypharmacy intensification is required to reach adequate metabolic control with the risk of adverse effects due to age-related changes in drug metabolism. The present review discusses the European Diabetes Working Party guidelines for type 2 diabetes in older persons with and without frailty and their importance on preventing or at least slowing down diverse aspects of disability. Topics: Adult; Aged; Aging; Blood Glucose; Comorbidity; Diabetes Mellitus, Type 2; Dipeptidyl Peptidase 4; Dipeptidyl-Peptidase IV Inhibitors; Enzyme Inhibitors; Glucagon-Like Peptide 1; Glycated Hemoglobin; Humans; Hypoglycemic Agents; Middle Aged; Prevalence | 2009 |
Brain glucagon-like peptide 1 signaling controls the onset of high-fat diet-induced insulin resistance and reduces energy expenditure.
Glucagon-like peptide-1 (GLP-1) is a peptide released by the intestine and the brain. We previously demonstrated that brain GLP-1 increases glucose-dependent hyperinsulinemia and insulin resistance. These two features are major characteristics of the onset of type 2 diabetes. Therefore, we investigated whether blocking brain GLP-1 signaling would prevent high-fat diet (HFD)-induced diabetes in the mouse. Our data show that a 1-month chronic blockage of brain GLP-1 signaling by exendin-9 (Ex9), totally prevented hyperinsulinemia and insulin resistance in HFD mice. Furthermore, food intake was dramatically increased, but body weight gain was unchanged, showing that brain GLP-1 controlled energy expenditure. Thermogenesis, glucose utilization, oxygen consumption, carbon dioxide production, muscle glycolytic respiratory index, UCP2 expression in muscle, and basal ambulatory activity were all increased by the exendin-9 treatment. Thus, we have demonstrated that in response to a HFD, brain GLP-1 signaling induces hyperinsulinemia and insulin resistance and decreases energy expenditure by reducing metabolic thermogenesis and ambulatory activity. Topics: Animals; Blood Glucose; Body Temperature Regulation; Brain Stem; Carbon Dioxide; Diabetes Mellitus, Type 2; Dietary Fats; Energy Metabolism; Glucagon-Like Peptide 1; Glucose Intolerance; Hyperinsulinism; Insulin Resistance; Ion Channels; Male; Mice; Mice, Inbred C57BL; Mitochondrial Proteins; Motor Activity; Muscle, Skeletal; Nitric Oxide Synthase Type II; Nitric Oxide Synthase Type III; Oxygen Consumption; Peptide Fragments; Physical Endurance; Proglucagon; RNA, Messenger; Signal Transduction; Uncoupling Protein 2 | 2008 |
Characteristics of GLP-1 and exendins action upon glucose transport and metabolism in type 2 diabetic rat skeletal muscle.
Exendin-4, a peptide 53% structurally homologous with glucagon-like peptide 1 (GLP-1), is insulinotropic and has an antidiabetic effect even more prolonged than that of GLP-1. Exendin-9 is an antagonist of GLP-1 receptor and action in several cell systems, but shows GLP-1- and exendin-4-agonistic characteristics in human muscle cells and tissue. The action of GLP-1 upon glucose transport and metabolism in muscle is mediated by specific receptors. In this study we investigated the effect of both exendin-4 and -9, relative to that of GLP-1, upon glucose transport and metabolism in the skeletal muscle from a streptozotocin-induced type 2 diabetic rat model, compared to normal. In normal rats, exendin-4, like GLP-1 and insulin, enhanced glucose uptake. This effect, which is mediated to a certain extent by some kinases (PI3K/ PKB, p70s6k and MAPKs), may be caused by the peptide acting, at least in part, through the muscle GLP-1 receptors. Exendin-9 also stimulated the same kinases, except for PKB, but failed to modify basal glucose uptake. Type 2 diabetic rats showed lower than normal basal muscle glucose transport and oxidation value, and higher glycogen synthase alpha activity and pyruvate release; however, no modification of glucose uptake by GLP-1 or exendin-4 was detected, at variance with insulin, and basal activity of PI3K/PKB was lower than normal, while that of p70s6k and MAPKs was higher. GLP-1 failed to affect the activity of any of the kinases, while exendin-4 increased the activity of PI3K, p70s6k and MAPKs, but not PKB, suggesting that this enzyme plays a major role in exendin-4 effect upon glucose transport in muscle. Topics: Animals; Biological Transport; Diabetes Mellitus, Type 2; Exenatide; Glucagon-Like Peptide 1; Glucose; Glycogen Synthase; Glycolysis; Humans; Insulin; Male; Muscle, Skeletal; Oxidation-Reduction; Peptides; Protein Kinase Inhibitors; Protein Kinases; Rats; Rats, Wistar; Swine; Venoms | 2008 |
DPP-4 inhibitors and GLP-1 analogues: for whom? Which place for incretins in the management of type 2 diabetic patients?
This review tries to delineate how to insert the GLP-1 based agents, DPP4-inhibitors (sitagliptin and vildagliptin) and GLP-1 analogues (exenatide and liraglutide), in the guidelines and the daily practice for the management of type 2 diabetes (T2DM). Orally administered DPP-4 inhibitors reduce HbA(1c) by 0.5-1.1%, without hypoglycaemic events and no weight gain. The subcutaneous injected GLP-1 analogues show larger reductions in HbA(1c) by 0.8-1.7% and a weight loss (1.75-3.8 kg) with most gastrointestinal common adverse events contributing to a significant treatment interruption. Regarding the efficacy, the cost and the safety of these drugs they will no challenge the use of metformin as the initial therapy of T2DM. In patients'not tolerating metformin or in older patients, DPP-4 inhibitors seem to be an excellent alternative monotherapy. Several studies argue in favour of the use of DPP-4 inhibitors in combination with metformin as a promising second line treatment. This combination offers advantages when compared to others currently used, particularly if one considers the more stringent guidelines with a higher risk of hypoglycaemic events in patient receiving sulfonylureas and mild hyperglycaemia or weight gain with thiazolidinedione (TZD). Oral triple therapy, metformin + TZD + incretin-based drug, has several theoretical advantages but is not supported by any published trial. Finally, obtaining the acceptance of injections once to twice daily vs. oral administration of OADs will probably remain difficult during the first years of treatment in many patients. Nevertheless a long-acting release exenatide formulation (i.e. once weekly), for subcutaneous injection in patients with type 2 diabetes under development shows promising preliminary results. If confirmed, the use of this new class of drugs should be largely developed from monotherapy to combinations (bitherapy or tritherapy), and even instead of insulin or in association with insulin. The long-term effect of GLP-1 based agents on glycaemic control has not yet been established, and their potential impact on beta-cell function in humans remains an area of active investigation. So, further studies are required and will allow progressively determining the use of incretin-based agents in T2DM treatment strategy. Their efficacy, safety and their cost vs. older strategies, will be really evaluated by physicians in the real daily practice and by large and long term systematic surveys, as recently shown Topics: Blood Glucose; Diabetes Mellitus, Type 2; Dipeptidyl Peptidase 4; Dipeptidyl-Peptidase IV Inhibitors; Drug Therapy, Combination; Glucagon-Like Peptide 1; Humans; Hypoglycemic Agents; Incretins; Metformin; Protease Inhibitors; Thiazolidinediones | 2008 |
Current, new, and emerging therapies for managing hyperglycaemia in type 2 diabetes.
Topics: Blood Glucose; Diabetes Mellitus, Type 2; Glucagon-Like Peptide 1; Humans; Hyperglycemia; Hypoglycemic Agents | 2008 |
[Incretin-mimetic drugs, an insulin alternative in type 2 diabetes].
Topics: Diabetes Mellitus, Type 2; Diet, Diabetic; Drug Therapy, Combination; Exenatide; Glucagon-Like Peptide 1; Homeostasis; Humans; Hypoglycemic Agents; Incretins; Injections, Subcutaneous; Insulin; Metformin; Patient Education as Topic; Patient Selection; Peptides; Venoms | 2008 |
Incretins: the novel therapy of type 2 diabetes.
Type 2 diabetes mellitus is a worldwide health problem. Adequate glycemic control can help to prevent many chronic diabetic complications. Despite the availability of several classes of oral hypoglycemic agents and insulin, many patients fail to achieve adequate glycemic control. Incretins are gut hormones produced in response to ingestion of nutrients. Glucagon-like peptide-1 (GLP-1), one of the incretin hormones, has pleiotropic actions on the control of blood glucose. Clinical trials with the incretin mimetic and Dipeptidyl peptidase-IV inhibitors demonstrate promising results in the improvement of glucose homeostasis. Topics: Diabetes Mellitus, Type 2; Dipeptidyl-Peptidase IV Inhibitors; Glucagon-Like Peptide 1; Humans; Incretins | 2008 |
Effects of intravenous glucagon-like peptide-1 on glucose control and hemodynamics after coronary artery bypass surgery in patients with type 2 diabetes.
Topics: Aged; Blood Glucose; Coronary Disease; Diabetes Mellitus, Type 2; Female; Glucagon-Like Peptide 1; Hemodynamics; Humans; Incretins; Injections, Intravenous; Male; Middle Aged; Postoperative Period; Treatment Outcome | 2008 |
Is secretion of glucagon-like peptide-1 reduced in type 2 diabetes mellitus?
Topics: Diabetes Mellitus, Type 2; Female; Glucagon-Like Peptide 1; Humans; Male | 2008 |
Combination pharmacotherapy with incretins: what works best and when?
The incretin hormone glucagon-like peptide-1 agonists and dipeptidyl peptidase-4 inhibitors fill an unaddressed therapeutic gap in the treatment of type 2 diabetes mellitus (T2DM) by potentiating insulin secretion in pancreatic beta cells, suppressing glucagon secretion, delaying gastric emptying, and reducing appetite. The incretin therapies, alone or in combination with metformin and/or thiazolidinediones, yield improved glycemic control without risk of hypoglycemia and the potential for weight neutrality or even weight loss. New incretin-based approaches offer promising new strategies for treating T2DM by recruiting new, physiologically based mechanisms of action for glucoregulation in the context of a favorable safety profile. Topics: Blood Glucose; Diabetes Mellitus, Type 2; Dipeptidyl-Peptidase IV Inhibitors; Drug Therapy, Combination; Exenatide; Glucagon-Like Peptide 1; Glucagon-Like Peptide-1 Receptor; Humans; Hypoglycemic Agents; Incretins; Insulin; Insulin Secretion; Islets of Langerhans; Liraglutide; Peptides; Receptors, Glucagon; Treatment Outcome; Venoms | 2008 |
[Antidiabetics and the incretin system].
Topics: Diabetes Mellitus, Type 2; Dipeptidyl-Peptidases and Tripeptidyl-Peptidases; Glucagon-Like Peptide 1; Humans; Hypoglycemic Agents; Incretins | 2008 |
Incretin based therapies for type 2 diabetes mellitus.
The incretin effect denominates the phenomenon that oral glucose elicits a higher insulin response than intravenous glucose. Glucagon like peptide-1 (GLP-1) and glucose-dependent insulinotropic peptide are the principal hormones responsible for incretin effect. In patients with type 2 diabetes the incretin effect of these hormones is impaired. Therapeutic approaches for enhancing the incretin action include degradation resistant GLP-1 receptor agonists (incretin mimetics) and inhibitors of dipeptidyl peptidase-IV (DLP-IV) activity (incretin enhancers- gliptins). These groups of medications have similar efficacy with regards to glycaemic improvement (reduction of HbA1c between 0.5 to 1.1%) and have side-effects like nausea. The incretin mimetics are injectable agents and are more likely to reduce weight or be weight neutral when compared to the oral gliptins. Long-term studies are essential to determine the real potential and role of these newer agents in the management of type 2 diabetes. Topics: Diabetes Mellitus, Type 2; Dipeptidyl-Peptidases and Tripeptidyl-Peptidases; Glucagon-Like Peptide 1; Humans; Incretins; Insulin | 2008 |
What is known, new and controversial about GLP-1? Minutes of the 1st European GLP-1 Club Meeting, Marseille, 28-29 May 2008.
The first antidiabetic agent was a hormone--insulin--and ever since, all therapeutic strategies have been based on the synthesis of chemical compounds to bind its receptors or transcription factors, or to trigger its intracellular mechanisms. Eighty years on, new therapeutic molecules are available for the treatment of diabetes and, again, are based on a hormone--glucagon-like peptide-1 (GLP-1). Whereas the theoretical benefit of insulin is based on normalization of functional physiology, therapeutic strategies based on GLP-1 aim to increase the circulating concentration of a natural component--the hormone GLP-1. There are two strategies for increasing GLP-1 plasma concentrations: replace the hormone with a long-acting analogue or molecule with a longer half-life; and prevent its degradation by inhibiting its natural protease, dipeptidyl peptidase IV (DPPIV). Although numerous clinical trials have been carried out and vast amounts of data are available, the mechanisms through which GLP-1-based therapy reduces blood glucose in diabetic patients remain unclear. Thus, it is essential to ask the right questions and to design appropriate clinical trials and experiments to increase our understanding of the mode of action of GLP-1-based therapy. For this reason, in the spring of 2008, expert scientists and clinicians in the field of GLP-1 got together for an intensive debate on the subject at the first meeting of the European Club for the study of GLP-1, held in Marseille. The subject of the round table discussions was: what is known, new and controversial about GLP-1? During these discussions, numerous facts and controversies were reevaluated, and revealed that several long-held, dogmatic beliefs have never been fully and scientifically established. These points are detailed here in these minutes of the landmark meeting. Topics: Animals; Cell Differentiation; Diabetes Mellitus, Type 1; Diabetes Mellitus, Type 2; France; Glucagon; Glucagon-Like Peptide 1; Humans; Insulin; Insulin Secretion; Insulin-Secreting Cells; L Cells; Mice | 2008 |
Four weeks of near-normalization of blood glucose has no effect on postprandial GLP-1 and GIP secretion, but augments pancreatic B-cell responsiveness to a meal in patients with Type 2 diabetes.
The aim of the present study was to investigate whether 4 weeks of near-normalization of blood glucose (BG) improves incretin hormone secretion and pancreatic B-cell function during a mixed meal.. Nine patients with Type 2 diabetes in poor glycaemic control [glycated haemoglobin (HbA(1c)) 8.0 +/- 0.4%] were investigated before and after 4 weeks of near-normalization of BG (mean BG 6.4 +/- 0.3 mmol/l) using insulin treatment. HbA(1c) after insulin treatment was 6.6 +/- 0.3%. For comparison, nine healthy control subjects were also studied. Postprandial glucagon-like peptide 1 (GLP-1) and glucose-dependent insulinotropic polypeptide (GIP) incremental responses were assessed during a mixed meal test. Fasting and postprandial pancreatic B-cell function was determined from calculations of insulin secretion rates in relation to plasma glucose.. There was no difference in IAUC(totalGLP-1) or in IAUC(totalGIP) between the two experimental days. B-cell sensitivity to glucose (insulinogenic index) did not differ before and after insulin treatment in the fasting state (0.21 +/- 0.17 vs. 0.25 +/- 0.10 pmol kg(-1) min(-1)/mmol l(-1)), but improved significantly during the first 30 min after start of the meal (0.28 +/- 0.07 vs. 0.46 +/- 0.06 pmol kg(-1) min(-1)/mmol l(-1)) and during the following 4 h (0.34 +/- 0.09 vs. 0.56 +/- 0.07 pmol kg(-1) min(-1)/ mmol l(-1)). The B-cell responsiveness to changes in plasma glucose, expressed as the slope of the linear relationship between the insulin secretion rate and the concomitant plasma glucose increased from 0.59 +/- 0.16 to 0.94 +/- 0.13 pmol kg(-1) min(-1)/ mmol l(-1) (P < 0.07).. Four weeks of near-normalization of BG had no effect on postprandial secretion of incretin hormones. Nevertheless, several parameters of meal-induced insulin secretion improved after insulin treatment. Topics: Area Under Curve; Blood Glucose; Diabetes Mellitus, Type 2; Eating; Fasting; Female; Gastric Inhibitory Polypeptide; Glucagon; Glucagon-Like Peptide 1; Humans; Hyperglycemia; Insulin; Insulin Secretion; Insulin-Secreting Cells; Male; Middle Aged; Postprandial Period | 2008 |
Decreased dipeptidyl peptidase-IV activity and glucagon-like peptide-1(7-36)amide degradation in type 2 diabetic subjects.
Dipeptidyl peptidase (DPP-IV) rapidly metabolizes hormones such as glucagon-like peptide-1(7-36)amide. This study evaluated circulating DPP-IV activity in type 2 diabetic patients in relation to GLP-1 degradation and metabolic control. Blood samples were collected from type 2 diabetic patients in three main categories: good glycaemic control (HbA(1c) <7%, upper limit of non-diabetic range), moderate glycaemic control (HbA(1c) 7-9%) and poor glycaemic control (HbA(1c) >9%). Age- and sex-matched non-diabetic subjects were used as controls. Circulating DPP-IV activity of healthy control subjects was 22.5+/-0.7 nmol/ml/min (n=70). In the combined groups of type 2 diabetic subjects, circulating DPP-IV activity was significantly decreased at 18.1+/-0.7 nmol/ml/min (p<0.001, n=54). DPP-IV activity was negatively correlated with both glucose (p<0.01) and HbA(1c) (p<0.01) in this population. Furthermore, DPP-IV activity was reduced 1.2-fold (p<0.01, n=25), 1.3-fold (p<0.001, n=19) and 1.3-fold (p<0.05, n=10) in good, moderate and poorly controlled diabetic groups, 18.7+/-1.0, 17.4+/-1.4 and 18.0+/-1.5 nmol/ml/min, respectively. Degradation of GLP-1 by in vitro incubation with pooled plasma samples from healthy and type 2 diabetic subjects revealed decreased degradation to the inactive metabolite, GLP-1(9-36), in the diabetic group. These data indicate decreased DPP-IV activity and GLP-1 degradation in type 2 diabetes. DPP-IV enzyme activity appears to be depressed in response to poor glycaemic control. Topics: Aged; Blood Glucose; Body Mass Index; Creatinine; Diabetes Mellitus, Type 2; Diet, Diabetic; Dipeptidyl Peptidase 4; Female; Glucagon-Like Peptide 1; Glycated Hemoglobin; Humans; Hypoglycemic Agents; Kinetics; Male; Middle Aged; Peptide Fragments | 2008 |
The diabetes-linked transcription factor Pax4 is expressed in human pancreatic islets and is activated by mitogens and GLP-1.
We previously demonstrated that the transcription factor Pax4 is important for beta-cell replication and survival in rat islets. Herein, we investigate Pax4 expression in islets of non-diabetic and diabetic donors, its regulation by mitogens, glucose and the incretin GLP-1 and evaluate its effect on human islet proliferation. Pax4 expression was increased in islets derived from Type 2 diabetic donors correlating with hyperglycaemia. In vitro studies on non diabetic islets demonstrated that glucose, betacellulin, activin A, GLP-1 and insulin increased Pax4 mRNA levels. Glucose-induced Pax4 expression was abolished by the inhibitors LY294002, PD98050 or H89. Surprisingly, increases in Pax4 expression did not prompt a surge in human islet cell replication. Furthermore, expression of the proliferation marker gene Id2 remained unaltered. Adenoviral-mediated expression of human Pax4 resulted in a small increase in Bcl-xL expression while Id2 transcript levels and cell replication were unchanged in human islets. In contrast, overexpression of mouse Pax4 induced human islet cell proliferation. Treatment of islets with 5-Aza-2'-deoxycytidine induced Pax4 without stimulating Bcl-xL and Id2 expression. Human Pax4 DNA binding activity was found to be lower than that of the mouse homologue. Thus, human pax4 gene expression is epigenetically regulated and induced by physiological stimuli through the concerted action of multiple signalling pathways. However, it is unable to initiate the transcriptional replication program likely due to post-translational modifications of the protein. The latter highlights fundamental differences between human and rodent islet physiology and emphasizes the importance of validating results obtained with animal models in human tissues. Topics: Activins; Animals; Betacellulin; Cell Proliferation; Diabetes Mellitus, Type 2; Epigenesis, Genetic; fas Receptor; Gene Expression; Glucagon-Like Peptide 1; Glucose; Homeodomain Proteins; Humans; In Vitro Techniques; Insulin; Insulin Secretion; Insulin-Secreting Cells; Intercellular Signaling Peptides and Proteins; Interleukin-1beta; Islets of Langerhans; Mitogens; Obesity; Paired Box Transcription Factors; Rats; RNA, Messenger; Signal Transduction; Transfection | 2008 |
Diminished phosphodiesterase-8B potentiates biphasic insulin response to glucose.
cAMP activates multiple signal pathways, crucial for the pancreatic beta-cells function and survival and is a major potentiator of insulin release. A family of phosphodiesterases (PDEs) terminate the cAMP signals. We examined the expression of PDEs in rat beta-cells and their role in the regulation of insulin response. Using RT-PCR and Western blot analyses, we identified PDE3A, PDE3B, PDE4B, PDE4D, and PDE8B in rat islets and in INS-1E cells and several possible splice variants of these PDEs. Specific depletion of PDE3A with small interfering (si) RNA (siPDE3A) led to a small (67%) increase in the insulin response to glucose in INS-1E cells but not rat islets. siPDE3A had no effect on the glucagon-like peptide-1 (10 nmol/liter) potentiated insulin response in rat islets. Depletion in PDE8B levels in rat islets using similar technology (siPDE8B) increased insulin response to glucose by 70%, the potentiation being of similar magnitude during the first and second phase insulin release. The siPDE8B-potentiated insulin response was further increased by 23% when glucagon-like peptide-1 was included during the glucose stimulus. In conclusion, PDE8B is expressed in a small number of tissues unrelated to glucose or fat metabolism. We propose that PDE8B, an 3-isobutyl-1-methylxanthine-insensitive cAMP-specific phosphodiesterase, could prove a novel target for enhanced insulin response, affecting a specific pool of cAMP involved in the control of insulin granule trafficking and exocytosis. Finally, we discuss evidence for functional compartmentation of cAMP in pancreatic beta-cells. Topics: 3',5'-Cyclic-AMP Phosphodiesterases; Animals; Cell Line, Tumor; Cyclic Nucleotide Phosphodiesterases, Type 3; Diabetes Mellitus, Type 2; Gene Expression Regulation, Enzymologic; Glucagon-Like Peptide 1; Glucose; Insulin; Insulin Secretion; Insulin-Secreting Cells; Insulinoma; Male; Pancreatic Neoplasms; Rats; Rats, Wistar | 2008 |
PEGylation improves the hypoglycaemic efficacy of intranasally administered glucagon-like peptide-1 in type 2 diabetic db/db mice.
PEGylation - covalent modification of therapeutic peptides with polyethylene glycol (PEG) - is viewed as an effective way of prolonging the short lifetime of glucagon-like peptide-1 (GLP-1). In this study, we investigated the hypoglycaemic efficacies of PEGylated GLP-1s administered intranasally in type 2 diabetic db/db mice.. Three types of site-specific (Lys(34)) PEGylated GLP-1 analogues (PEG molecular weight: 1, 2 or 5 kDa) were synthesized. Their metabolic stabilities were evaluated in nasal mucosa enzyme pools. Oral glucose tolerance test was conducted 30, 60 and 120 min after intranasally administering these analogues in type 2 diabetic db/db mice.. PEGylated GLP-1 analogues were found to have significantly longer half-lives than native GLP-1 in nasal mucosa enzymes (2.4-fold to 11.0-fold, p < 0.005). Non-PEGylated GLP-1 at 100 nmol/kg was not found to have marked efficacy irrespective of nasal administration time [total hypoglycaemic degree (HD(total)) values 2.8-17.3%]. On the contrary, PEGylated GLP-1s (100 nmol/kg) showed obvious efficacies with maximum HD(total) values of >51.8 +/- 5.8% (p < 0.005 vs. GLP-1).. This study highlights the pharmacological potential of intranasally administered PEGylated GLP-1s in terms of stabilizing postprandial hyperglycaemia in type 2 diabetic patients. Topics: Administration, Inhalation; Animals; Blood Glucose; Diabetes Mellitus, Experimental; Diabetes Mellitus, Type 2; Drug Carriers; Glucagon-Like Peptide 1; Glucose Tolerance Test; Half-Life; Hypoglycemic Agents; Insulin; Male; Mice; Mice, Inbred C57BL; Mice, Mutant Strains; Polyethylene Glycols | 2008 |
Predictors of incretin concentrations in subjects with normal, impaired, and diabetic glucose tolerance.
Defects in glucagon-like peptide 1 (GLP-1) secretion have been reported in some patients with type 2 diabetes after meal ingestion. We addressed the following questions: 1) Is the quantitative impairment in GLP-1 levels different after mixed meal or isolated glucose ingestion? 2) Which endogenous factors are associated with the concentrations of GLP-1? In particular, do elevated fasting glucose or glucagon levels diminish GLP-1 responses?. Seventeen patients with mild type 2 diabetes, 17 subjects with impaired glucose tolerance, and 14 matched control subjects participated in an oral glucose tolerance test (75 g) and a mixed meal challenge (820 kcal), both carried out over 240 min on separate occasions. Plasma levels of glucose, insulin, C-peptide, glucagon, triglycerides, free fatty acids (FFAs), gastric inhibitory polypeptide (GIP), and GLP-1 were determined.. GIP and GLP-1 levels increased significantly in both experiments (P < 0.0001). In patients with type 2 diabetes, the initial GIP response was exaggerated compared with control subjects after mixed meal (P < 0.001) but not after oral glucose ingestion (P = 0.98). GLP-1 levels were similar in all three groups in both experiments. GIP responses were 186 +/- 17% higher after mixed meal ingestion than after the oral glucose load (P < 0.0001), whereas GLP-1 levels were similar in both experiments. There was a strong negative association between fasting glucagon and integrated FFA levels and subsequent GLP-1 concentrations. In contrast, fasting FFA and integrated glucagon levels after glucose or meal ingestion and female sex were positively related to GLP-1 concentrations. Incretin levels were unrelated to measures of glucose control or insulin secretion.. Deteriorations in glucose homeostasis can develop in the absence of any impairment in GIP or GLP-1 levels. This suggests that the defects in GLP-1 concentrations previously described in patients with long-standing type 2 diabetes are likely secondary to other hormonal and metabolic alterations, such as hyperglucagonemia. GIP and GLP-1 concentrations appear to be regulated by different factors and are independent of each other. Topics: Aged; Blood Glucose; Diabetes Mellitus, Type 2; Fatty Acids, Nonesterified; Female; Gastric Inhibitory Polypeptide; Glucagon; Glucagon-Like Peptide 1; Glucose; Glucose Intolerance; Glucose Tolerance Test; Humans; Incretins; Male; Middle Aged; Triglycerides | 2008 |
Preparation, characterization, and application of biotinylated and biotin-PEGylated glucagon-like peptide-1 analogues for enhanced oral delivery.
Glucagon-like peptide-1 (GLP-1) (7-36) is a type of incretin hormone with unique antidiabetic potential. The introduction of orally active GLP-1 offers substantial benefits in the treatment of type 2 diabetes over conventional injection-based therapies. Because the intestinal absorption of GLP-1 is restricted by its natural characteristics, we developed a series of GLP-1 analogues via the site-specific conjugation of biotin-NHS and/or of biotin-poly(ethylene glycol)-NHS at Lys 26 and Lys 34 of GLP-1 (7-36), respectively, in order to improve oral delivery. The resultant GLP-1 analogues, Lys 26,34-DiBiotin-GLP-1 (DB-GLP-1) and Lys 26-Biotin-Lys 34-(Biotin-PEG)-GLP-1 (DBP-GLP-1), were prepared and studied in terms of their chemical, structural, and biological properties. DBP-GLP-1 demonstrated superior proteolytic stability against trypsin, intestinal fluid, and the major GLP-1 inactivation enzyme (dipeptidyl peptidase-IV (DPP-IV)) to native GLP-1 or DB-GLP-1 ( p < 0.001). The in vitro insulinotropic effects of DB-GLP-1 and DBP-GLP-1 showed potent biological activity in a dose-dependent manner, which resembled that of native GLP-1 in terms of stimulating insulin secretion in isolated rat islets of Langerhans. Intraperitoneal glucose tolerance tests (IPGTT) after the oral administration of GLP-1 analogues in diabetic db/db mice demonstrated that DB-GLP-1 and DBP-GLP-1 significantly reduced the AUC 0-180 min of glucose for 3 h by 14.9% and 24.5% compared to that of native GLP-1, respectively ( p < 0.01). In particular, DBP-GLP-1 concentration in plasma rapidly increased 30 min after oral administration in rats, presumably due to improved intestinal absorption. These findings revealed that site-specific biotinylated and biotin-PEGylated GLP-1 is absorbed by intestine and that it has biological activity in vivo. Therefore, we propose that this orally active bioconjugated GLP-1 might be considered as a potential oral antidiabetic agent for type 2 diabetes mellitus. Topics: Absorption; Administration, Oral; Animals; Binding Sites; Biotin; Biotinylation; Blood Glucose; Diabetes Mellitus, Type 2; Enzyme Stability; Glucagon-Like Peptide 1; Hypoglycemic Agents; Injections, Intraperitoneal; Intestinal Mucosa; Lysine; Mice; Peptide Hydrolases; Polyethylene Glycols; Rats; Sensitivity and Specificity | 2008 |
Insulin sensitivity, insulin release and glucagon-like peptide-1 levels in persons with impaired fasting glucose and/or impaired glucose tolerance in the EUGENE2 study.
We examined the phenotype of individuals with impaired fasting glucose (IFG) and/or impaired glucose tolerance (IGT) with regard to insulin release and insulin resistance.. Non-diabetic offspring (n=874; mean age 40+/-10.4 years; BMI 26.6+/-4.9 kg/m(2)) of type 2 diabetic patients from five different European Centres (Denmark, Finland, Germany, Italy and Sweden) were examined with regard to insulin sensitivity (euglycaemic clamps), insulin release (IVGTT) and glucose tolerance (OGTT). The levels of glucagon-like peptide-1 (GLP-1) and gastric inhibitory polypeptide (GIP) were measured during the OGTT in 278 individuals.. Normal glucose tolerance was found in 634 participants, while 110 had isolated IFG, 86 had isolated IGT and 44 had both IFG and IGT, i.e. about 28% had a form of reduced glucose tolerance. Participants with isolated IFG had lower glucose-corrected first-phase (0-10 min) and higher second-phase insulin release (10-60 min) during the IVGTT, while insulin sensitivity was reduced in all groups with abnormal glucose tolerance. Similarly, GLP-1 but not GIP levels were reduced in individuals with abnormal glucose tolerance.. The primary mechanism leading to hyperglycaemia in participants with isolated IFG is likely to be impaired basal and first-phase insulin secretion, whereas in isolated IGT the primary mechanism leading to postglucose load hyperglycaemia is insulin resistance. Reduced GLP-1 levels were seen in all groups with abnormal glucose tolerance and were unrelated to the insulin release pattern during an IVGTT. Topics: Adult; Blood Glucose; Diabetes Mellitus, Type 2; Family; Fasting; Female; Gastric Inhibitory Polypeptide; Glucagon-Like Peptide 1; Glucose Intolerance; Glucose Tolerance Test; Humans; Insulin; Insulin Secretion; Male; Middle Aged; Reference Values | 2008 |
Adenoviral vector-mediated glucagon-like peptide 1 gene therapy improves glucose homeostasis in Zucker diabetic fatty rats.
Glucagon-like peptide-1 (GLP-1) is a gut-derived incretin hormone that plays an important role in glucose homeostasis. Its functions include glucose-stimulated insulin secretion, suppression of glucagon secretion, deceleration of gastric emptying, and reduction in appetite and food intake. Despite the numerous antidiabetic properties of GLP-1, its therapeutic potential is limited by its short biological half-life due to rapid enzymatic degradation by dipeptidyl peptidase IV. The present study aimed to demonstrate the therapeutic effects of constitutively expressed GLP-1 in an overt type 2 diabetic animal model using an adenoviral vector system.. A novel plasmid (pAAV-ILGLP-1) and recombinant adenoviral vector (Ad-ILGLP-1) were constructed with the cytomegalovirus promoter and insulin leader sequence followed by GLP-1(7-37) cDNA.. The results of an enzyme-linked immunosorbent assay showed significantly elevated levels of GLP-1(7-37) secreted by human embryonic kidney cells transfected with the construct containing the leader sequence. A single intravenous administration of Ad-ILGLP-1 into 12-week-old Zucker diabetic fatty (ZDF) rats, which have overt type 2 diabetes mellitus (T2DM), achieved near normoglycemia for 3 weeks and improved utilization of blood glucose in glucose tolerance tests. Circulating plasma levels of GLP-1 increased in GLP-1-treated ZDF rats, but diminished 21 days after treatment. When compared with controls, Ad-ILGLP-1-treated ZDF rats had a lower homeostasis model assessment for insulin resistance score indicating amelioration in insulin resistance. Immunohistochemical staining showed that cells expressing GLP-1 were found in the livers of GLP-1-treated ZDF rats.. These data suggest that GLP-1 gene therapy can improve glucose homeostasis in fully developed diabetic animal models and may be a promising treatment modality for T2DM in humans. Topics: Adenoviridae; Animals; Blood Glucose; Diabetes Mellitus, Type 2; Genetic Therapy; Genetic Vectors; Glucagon-Like Peptide 1; Humans; Insulin; Rats; Rats, Zucker; RNA, Messenger | 2008 |
Comment on: Knop et al. (2007) Reduced incretin effect in type 2 diabetes: cause or consequence of the diabetic state? Diabetes 56:1951-1959.
Topics: Area Under Curve; Diabetes Mellitus, Type 2; Glucagon-Like Peptide 1; Humans; Incretins; Models, Biological | 2008 |
Racial disparity in glucagon-like peptide 1 and inflammation markers among severely obese adolescents.
Compared with Caucasians, obese African-American adolescents have a higher risk for type 2 diabetes. Subclinical inflammation and reduced glucagon-like peptide 1 (GLP-1) concentration are linked to the pathogenesis of the disease. We determined the relationship between insulin resistance, beta-cell activity, and subclinical inflammation with GLP-1 concentrations and whether racial disparities in GLP-1 response were present in 49 obese adolescents (14 +/- 3 years; 76% African American; 71% female).. Subjects underwent physical examination and an oral glucose tolerance test. We measured levels of high-sensitivity CRP (CRP(hs)), fibrinogen, glucose, GLP-1(total), GLP-1(active), and insulin. Insulin and glucose area under the curve (AUC), insulinogenic index (DeltaI30/DeltaG30), and composite insulin sensitivity index (CISI) were computed. Subjects were categorized by race and as inflammation positive (INF+) if CRP(hs) or fibrinogen were elevated.. No racial differences were seen in mean or relative BMI. Thirty-five percent of subjects had altered fasting or 2-h glucose levels (African American vs. Caucasian, NS), and 75% were INF+ (African American vs. Caucasian, P = 0.046). Glucose and insulin, CISI, and DeltaI30/DeltaG30 values were similar; African Americans had lower GLP-1(total) AUC (P = 0.01), GLP-1(active) at 15 min (P = 0.03), and GLP-1(active) AUC (P = 0.06) and higher fibrinogen (P = 0.01) and CRP(hs) (NS) compared with Caucasians.. African Americans exhibited lower GLP-1 concentrations and increased inflammatory response. Both mechanisms may act synergistically to enhance the predisposition of obese African Americans to type 2 diabetes. Our findings might be relevant to effective deployment of emerging GLP-1-based treatments across ethnicities. Topics: Adolescent; Biomarkers; Black People; Blood Pressure; C-Reactive Protein; Child; Diabetes Mellitus, Type 2; Female; Glucagon-Like Peptide 1; Humans; Hypertension; Inflammation; Insulin Resistance; Male; Obesity; White People | 2008 |
Clinical decisions. Management of type 2 diabetes.
Topics: Diabetes Mellitus, Type 2; Dipeptidyl-Peptidase IV Inhibitors; Drug Therapy, Combination; Female; Glipizide; Glucagon-Like Peptide 1; Humans; Hypertension; Hypoglycemic Agents; Insulin; Metformin; Middle Aged; Obesity; Pioglitazone; Thiazolidinediones | 2008 |
GLP-1 C-terminal structures affect its blood glucose lowering-function.
Glucagon-like peptide-1 (GLP-1), which is an endogenous insulinotropic peptide that can stimulate islet cells to secret insulin, is a promising new drug candidate for the treatment of type 2 diabetes. However, due to the very short half-life of this peptide, the clinical value of GLP-1 is restricted. A GLP-1 peptide analog that had been altered by deletion of five amino acids from the C-terminus (sGLP-1) was selected and investigated in vivo for the therapeutic effect on GK rats with type II DM (T2DM). The results revealed that sGLP-1 exhibited decreased blood glucose-lowering ability compared to GLP-1 in the first week, as measured after once-daily administration. However, after drug administration for 2 weeks, the blood glucose-lowering effect of sGLP-1 became superior to that of GLP-1. sGLP-1 reduced apoptosis of the old islets, enhanced insulin production, and promoted new islets replication. sGLP-1 is a shorter but more efficient GLP-1 analog for type 2 diabetes management. Because sGLP-1 prolonged the proliferation and recovery of islet cells, the ability to maintain blood glucose (BG) within a normal range was still present 2 weeks after drug withdrawal. These results confirmed the importance of the C-terminus of GLP-1 molecule, and further demonstrated that GLP-1 (7-37) can be truncated till the 32nd amino acid to have a better long-term BG lowing function. This result may imply for the presence of glucagon family clearance receptors in vivo and demonstrates that the C-terminus participates in GLP-1 clearance. Topics: Animal Feed; Animals; Apoptosis; Blood Glucose; Cell Proliferation; Diabetes Mellitus, Type 2; Fats; Female; Glucagon-Like Peptide 1; Glucose Tolerance Test; Islets of Langerhans; Male; Mice; Peptide Fragments; Rats; Streptozocin | 2008 |
Watch out for the little guy.
Topics: Biomedical Research; Capital Financing; Diabetes Mellitus, Type 2; Glucagon-Like Peptide 1; Humans; Incretins | 2008 |
The GLP-1 concept in the treatment of type 2 diabetes--still standing at the gate of dawn?
Topics: Biomimetic Materials; Clinical Trials as Topic; Diabetes Mellitus, Type 2; Dipeptidyl-Peptidase IV Inhibitors; Glucagon-Like Peptide 1; Glycated Hemoglobin; Humans | 2008 |
Near normalisation of blood glucose improves the potentiating effect of GLP-1 on glucose-induced insulin secretion in patients with type 2 diabetes.
The ability of glucagon-like peptide-1 (GLP-1) to enhance beta cell responsiveness to i.v. glucose is impaired in patients with type 2 diabetes mellitus compared with healthy individuals. We investigated whether 4 weeks of near normalisation of blood glucose (BG) improves the potentiation of glucose-stimulated insulin secretion by GLP-1.. Nine obese patients with type 2 diabetes and inadequate glycaemic control (HbA(1c) 8.0+/-0.4%) were investigated before and after 4 weeks of near normalisation of BG using insulin treatment (mean diurnal blood glucose 6.4+/-0.3 mmol/l, HbA(1c) 6.6+/-0.3%). Nine matched healthy participants were also studied. Beta cell function was investigated before and after insulin treatment using stepwise glucose infusions and infusion of saline or GLP-1 (1.0 pmol kg(-1) min(-1)), resulting in supraphysiological total GLP-1 concentrations of approximately 200 pmol/l. The responsiveness to glucose or glucose+GLP-1 was expressed as the slope of the linear regression line relating insulin secretion rate (ISR) and plasma glucose concentration (pmol kg(-1) min(-1) [mmol/l](-1)).. In the diabetic participants, the slopes during glucose+saline infusion did not differ before and after insulin treatment (0.33+/-0.07 and 0.39+/-0.04, respectively; p=NS). In contrast, near normalisation of blood glucose improved beta cell sensitivity to glucose during glucose+GLP-1 infusion (1.27+/-0.2 before vs 1.73+/-0.31 after; p<0.01). In the healthy participants, the slopes during the glucose+saline and glucose+GLP-1 infusions were 1.01+/-0.14 and 4.79+/-0.53, respectively.. A supraphysiological dose of GLP-1 enhances beta cell responses to glucose in patients with type 2 diabetes, and 4 weeks of near normalisation of blood glucose further improves this effect. Topics: Blood Glucose; Body Mass Index; Diabetes Mellitus, Type 2; Female; Glucagon-Like Peptide 1; Glucose; Humans; Insulin; Insulin Secretion; Kinetics; Male; Middle Aged; Peptide Fragments; Reference Values | 2008 |
Combination of the insulin sensitizer, pioglitazone, and the long-acting GLP-1 human analog, liraglutide, exerts potent synergistic glucose-lowering efficacy in severely diabetic ZDF rats.
Severe insulin resistance and impaired pancreatic beta-cell function are pathophysiological contributors to type 2 diabetes, and ideally, antihyperglycaemic strategies should address both.. Therapeutic benefits of combining the long-acting human glucagon-like peptide-1 (GLP-1) analog, liraglutide (0.4 mg/kg/day), with insulin sensitizer, pioglitazone (10 mg/kg/day), were assessed in severely diabetic Zucker diabetic fatty rats for 42 days. Impact on glycaemic control was assessed by glycated haemoglobin (HbA(1C)) at day 28 and by oral glucose tolerance test at day 42.. Liraglutide and pioglitazone synergistically improved glycaemic control as reflected by a marked decrease in HbA(1C) (liraglutide + pioglitazone: 4.8 +/- 0.3%; liraglutide: 8.8 +/- 0.6%; pioglitazone: 7.9 +/- 0.4%; vehicle: 9.7 +/- 0.3%) and improved oral glucose tolerance at day 42 (area under the curve; liraglutide + pioglitazone: 4244 +/- 445 mmol/l x min; liraglutide: 7164 +/- 187 mmol/l x min; pioglitazone: 7430 +/- 446 mmol/l x min; vehicle: 8093 +/- 139 mmol/l x min). A 24-h plasma glucose profile at day 38 was significantly decreased only in the liraglutide + pioglitazone group. In addition, 24-h insulin profile was significantly elevated only in the liraglutide + pioglitazone group. Liraglutide significantly decreased food intake alone and in combination with pioglitazone, while pioglitazone alone increased cumulated food intake. As a result, rats on liraglutide alone gained significantly less weight than vehicle-treated rats, whereas rats on pioglitazone alone gained significantly more body weight than vehicle-treated rats. However, combination therapy with liraglutide and pioglitazone caused the largest weight gain, probably reflecting marked improvement of energy balance because of reduction of glucosuria.. Combination therapy with insulinotropic GLP-1 agonist liraglutide and insulin sensitizer, pioglitazone, improves glycaemic control above and beyond what would be expected from additive effects of the two antidiabetic agents. Topics: Animals; Biomarkers; Blood Glucose; Diabetes Mellitus, Type 2; Drug Synergism; Drug Therapy, Combination; Energy Metabolism; Glucagon-Like Peptide 1; Glucose Tolerance Test; Glycated Hemoglobin; Humans; Hypoglycemic Agents; Islets of Langerhans; Liraglutide; Male; Models, Animal; Pioglitazone; Rats; Rats, Zucker; Thiazolidinediones; Weight Gain | 2008 |
Laparoscopic treatment of metabolic syndrome in patients with type 2 diabetes mellitus.
Metabolic syndrome refers to risk factors for cardiovascular disease. Hyperglycemia is a critical component contributing to the predictive power of the syndrome. This study aimed to evaluate the results from the laparoscopic interposition of an ileum segment into the proximal jejunum for the treatment of metabolic syndrome in patients with type 2 diabetes mellitus and a body mass index (BMI) lower than 35.. Laparoscopic procedures were performed for 60 patients (24 women and 36 men) with a mean age of 51.7 +/- 6.4 years (range, 27-66 years) and a mean BMI of 30.1 +/- 2.7 (range, 23.6-34.4). All the patients had a diagnosis of type 2 diabetes mellitus (T2DM) given at least 3 years previously and evidence of stable treatment using oral hypoglycemic agents, insulin, or both for at least 12 months. The mean duration of type 2 diabetes mellitus was 9.6 +/- 4.6 years (range, 3-22 years). Metabolic syndrome was diagnosed for all 60 patients. Arterial hypertension was diagnosed for 70% of the patients (mean number of drugs, 1.6) and hypertriglyceridemia for 70%. High-density lipoprotein was altered in 51.7% of the patients and the abdominal circumference in 68.3%. Two techniques were performed: ileal interposition (II) into the proximal jejunum and sleeve gastrectomy (II-SG) or ileal interposition associated with a diverted sleeve gastrectomy (II-DSG).. The II-SG procedure was performed for 32 patients and the II-DSG procedure for 28 patients. The mean postoperative follow-up period was 7.4 months (range, 3-19 months). The mean BMI was 23.8 +/- 4.1 kg/m(2), and 52 patients (86.7%) achieved adequate glycemic control. Hypertriglyceridemia was normalized for 81.7% of the patients. An high-density lipoprotein level higher than 40 for the men and higher than 50 for the women was achieved by 90.3% of the patients. The abdominal circumference reached was less than 102 cm for the men and 88 cm for the women. Arterial hypertension was controlled in 90.5% of the patients. For the control of metabolic syndrome, II-DSG was the more effective procedure.. Laparoscopic II-SG and II-DSG seem to be promising procedures for the control of the metabolic syndrome and type 2 diabetes mellitus. A longer follow-up period is needed. Topics: Adult; Aged; Blood Glucose; Blood Pressure; Body Mass Index; Cholesterol; Diabetes Mellitus, Type 2; Female; Gastrectomy; Gastric Bypass; Glucagon-Like Peptide 1; Humans; Ileum; Insulin; Jejunum; Laparoscopy; Male; Metabolic Syndrome; Middle Aged; Triglycerides | 2008 |
[Sitagliptine (Januvia): incretin enhancer potentiating insulin secretion for the treatment of type 2 diabetes].
Sitagliptin (Januvia) is the first selective antagonist of dipeptidylpeptidase-4, an enzyme that degrades glucagon-like peptide-1 (GLP-1). This hormone is mainly secreted by ileal L cells and this secretion is abnormally low in patients with type 2 diabetes. Sitagliptin increases post-meal insulin secretion ("incretin effect) by enhancing the postprandial GLP-1 response ("incretin enhancer"), in a glucose-dependent manner. It improves glycaemic control (HbA1c) in type 2 diabetic patients treated by diet alone, by metformin, by sulfonylurea, by glitazone or by a metformin-sufonylurea combined therapy. The glucose-lowering effect is similar to that of glipizide, but with the advantage of no weight gain and no hypoglycaemic episodes. The tolerance to sitagliptin is excellent. Treatment is simple, with 100 mg once daily, without need of titration or home blood glucose monitoring. In Belgium, sitagliptin is currently reimbursed in patients with type 2 diabetes not adequately controlled with diet and metformin monotherapy. Topics: Belgium; Diabetes Mellitus, Type 2; Glucagon-Like Peptide 1; Humans; Hypoglycemic Agents; Incretins; Insulin; Insulin Secretion; Insurance, Health, Reimbursement; Insurance, Pharmaceutical Services; Pyrazines; Sitagliptin Phosphate; Triazoles | 2008 |
Dipeptidyl peptidase IV inhibitors in diabetes: more than inhibition of glucagon-like peptide-1 metabolism?
Inhibitors of the protease dipeptidyl peptidase IV (DPP-IV) are promising new drugs for the treatment of type 2 diabetes. They are thought to act by inhibiting the breakdown of glucagon-like peptide-1 and, thereby, selectively enhancing insulin release under conditions when it is physiologically required. These drugs are selective for DPP-IV, but the enzyme itself has a broad range of substrates other than glucagon-like peptide-1. Other high affinity substrates of DPP-IV including peptide YY may also play a role in the regulation of energy homeostasis. Moreover, DPP-IV is also known as CD26 and considered to be a moonlighting protein because it has a wide range of other functions unrelated to energy homeostasis, e.g. in immunity. The potential role of DPP-IV inhibition on substrates other than glucagon-like peptide-1 in diabetes patients remains to be elucidated. Topics: Animals; Diabetes Mellitus, Type 2; Dipeptidyl Peptidase 4; Dipeptidyl-Peptidase IV Inhibitors; Drug Delivery Systems; Glucagon-Like Peptide 1; Humans; Hypoglycemic Agents; Protease Inhibitors | 2008 |
Pharmacological profile of ASP8497, a novel, selective, and competitive dipeptidyl peptidase-IV inhibitor, in vitro and in vivo.
Dipeptidyl peptidase (DPP)-IV is involved in the inactivation of glucagon-like peptide-1 (GLP-1), a potent insulinotropic peptide. Thus, DPP-IV inhibitors are expected to become a useful new class of antidiabetic agent. This report describes the pharmacological profile of the novel DPP-IV inhibitor, ASP8497 [(2S,4S)-4-fluoro-1-({[4-methyl-1-(methylsulfonyl)piperidin-4-yl]amino}acetyl)pyrrolidine-2-carbonitrile monofumarate], both in vitro and in vivo. ASP8497 inhibited DPP-IV in plasma from mice, dogs, and humans with median inhibition concentration (IC(50)) values of 2.6 nM, 7.3 nM, and 6.2 nM, respectively. In contrast, ASP8497 did not potently inhibit human DPP8 or DPP9 activity (IC(50)=1,700 nM and 100 nM, respectively) and exhibited selectivity against several proteases, including proline-specific proteases (IC(50)>10 microM). Kinetic analysis indicated that ASP8497 is a competitive DPP-IV inhibitor. In normal mice, ASP8497 inhibited plasma DPP-IV activity even 12 h after administration. ASP8497 significantly inhibited increases in the blood glucose level during the oral glucose tolerance test (OGTT) conducted 0.5 h after administration. This was accompanied by increases in the plasma active GLP-1 and insulin levels. In addition, ASP8497 significantly inhibited increases in the blood glucose level during the OGTT conducted 8 h after administration. Furthermore, in Zucker fatty rats, ASP8497 dose dependently improved glucose tolerance with significance at doses of 1 mg/kg or higher. In contrast, ASP8497 did not cause hypoglycemia in fasted normal mice. These results indicate that ASP8497 is a potent, competitive, and selective DPP-IV inhibitor with antihyperglycemic activity. Topics: Animals; Blood Glucose; Diabetes Mellitus, Type 2; Dipeptidases; Dipeptidyl Peptidase 4; Dipeptidyl-Peptidases and Tripeptidyl-Peptidases; Dogs; Dose-Response Relationship, Drug; Glucagon-Like Peptide 1; Glucose Tolerance Test; Humans; Hypoglycemic Agents; Inhibitory Concentration 50; Insulin; Male; Mice; Mice, Inbred ICR; Piperidines; Protease Inhibitors; Pyrrolidines; Rats; Rats, Sprague-Dawley; Rats, Zucker | 2008 |
Increased secretion and expression of amylin in spontaneously diabetic Goto-Kakizaki rats treated with rhGLP-1 (7-36).
To investigate the effect of recombined human glucagon-like peptide 1 (rhGLP-1 [7-36]) on the secretion and expression of amylin in Goto-Kakizaki (GK) rats.. The GK rats were treated with rhGLP-1 (7-36) 56 and 133 mug/kg subcutaneously for 12 weeks. The fasting and post-prandial blood glucose levels were measured. The plasma amylin concentration was measured by ELISA. The transcription levels of amylin and insulin mRNA were evaluated by fluorescent-quantitative- PCR. Immunohistochemistry was utilized to detect the amylin protein. Histological examination was assayed by light microscopy.. Treatment with rhGLP-1 (7-36) caused a significant reduction of post-prandial blood glucose levels in the GK rats (P<0.05). The plasma amylin levels of the GK rats were lower than those of Wistar rats after the glucose administration (P<0.01). Treatment with rhGLP-1 (7-36) exhibited a marked elevation of the glucose-stimulated plasma amylin level (P<0.05) and slight histological amelioration. The amylin expression was augmented in the rhGLP-1 (7-36)-treated GK rat pancreas. Amylin and insulin mRNA were also highly expressed in the treated GK rats (P<0.05). However, the ratio of amylin to insulin mRNA was significantly decreased by treatment with rhGLP-1 (7-36).. RhGLP-1 (7-36) stimulates the secretion and expression of amylin, and exerts a beneficial effect on the ratio of amylin to insulin mRNA. These findings suggest that GLP-1 and GLP-1 analogs are ideal candidates for the treatment of type 2 diabetes. Topics: Amyloid; Animals; Blood Glucose; Diabetes Mellitus, Type 2; Eating; Fasting; Gene Expression; Glucagon-Like Peptide 1; Glucose; Humans; Hypoglycemic Agents; Immunohistochemistry; Insulin; Islet Amyloid Polypeptide; Male; Rats; Rats, Wistar; Recombinant Proteins; RNA, Messenger; Time Factors | 2008 |
Effect of weight loss by gastric bypass surgery versus hypocaloric diet on glucose and incretin levels in patients with type 2 diabetes.
Gastric bypass surgery (GBP) results in rapid weight loss, improvement of type 2 diabetes (T2DM), and increase in incretins levels. Diet-induced weight loss also improves T2DM and may increase incretin levels.. Our objective was to determine whether the magnitude of the change of the incretin levels and effect is greater after GBP compared with a low caloric diet, after equivalent weight loss.. Obese women with T2DM studied before and 1 month after GBP (n = 9), or after a diet-induced equivalent weight loss (n = 10), were included in the study. Patients from both groups were matched for age, body weight, body mass index, diabetes duration and control, and amount of weight loss.. This outpatient study was conducted at the General Clinical Research Center.. Glucose, insulin, proinsulin, glucagon, gastric inhibitory peptide (GIP), and glucagon-like peptide (GLP)-1 levels were measured after 50-g oral glucose. The incretin effect was measured as the difference in insulin levels in response to oral and to an isoglycemic iv glucose load.. At baseline, none of the outcome variables (fasting and stimulated values) were different between the GBP and diet groups. Total GLP-1 levels after oral glucose markedly increased six times (peak:17 +/- 6 to 112 +/- 54 pmol/liter; P < 0.001), and the incretin effect increased five times (9.4 +/- 27.5 to 44.8 +/- 12.7%; P < 0.001) after GBP, but not after diet. Postprandial glucose levels (P = 0.001) decreased more after GBP.. These data suggest that early after GBP, the greater GLP-1 and GIP release and improvement of incretin effect are related not to weight loss but rather to the surgical procedure. This could be responsible for better diabetes outcome after GBP. Topics: Adult; Blood Glucose; Diabetes Mellitus, Type 2; Diet, Reducing; Female; Gastric Bypass; Gastric Inhibitory Polypeptide; Glucagon; Glucagon-Like Peptide 1; Humans; Incretins; Male; Middle Aged; Obesity; Weight Loss | 2008 |
Medicine. Bypassing medicine to treat diabetes.
Topics: Animals; Diabetes Mellitus, Type 2; Gastric Bypass; Gastrointestinal Hormones; Ghrelin; Glucagon-Like Peptide 1; Humans; Hypoglycemia; Insulin; Insulin Secretion; Insulin-Secreting Cells; Intestinal Mucosa; Obesity; Postoperative Complications | 2008 |
Exenatide and rare adverse events.
Topics: Adult; Aged; Animals; Diabetes Mellitus, Type 2; Exenatide; Female; Glucagon-Like Peptide 1; Humans; Hypoglycemic Agents; Lizards; Male; Middle Aged; Pancreatitis; Peptides; Venoms | 2008 |
[Effects of glucagon like peptide-1 treatment on the alveolar capillary basal lamina in Otsuka Long-Evans Tokushima Fatty rats].
To observe and quantitatively analyze the effect of glucagon like peptide-1 (GLP-1) on the alveolar capillary basal lamina in spontaneous type 2 diabetes mellitus animal model Otsuka Long-Evans Tokushima Fatty (OLETF) rats.. Experimental rats were divided into three groups: OLETF group, GLP-1-treated group (OLETF/G group), and Long-Evans Tokushima Otsuka group (LETO group) as control. The ultrastructure and thickness of the alveolar capillary basal lamina in the rats were examined by transmission electron microscopy and morphometry methods.. The fused basal lamina (F-BL) of the alveolar capillary endothelium and type I epithelial basal lamina, and the alveolar capillary endothelium basal lamina (Cap-BL) were thickened in OLETF rats than those of LETO rats [(110.60+/-14.14) nm vs (57.30+/-11.08) nm, and (118.40+/-19.12) nm vs (66.80+/-8.63) nm, P<0.01]. F-BL and Cap-BL were thinned in the OLETF/G group as compared with OLETF group [(79.70+/-5.44) nm vs (110.60+/-14.14) nm and (69.80 +/-3.32) nm vs (118.40+/-19.12) nm, P<0.01].. Our studies suggest the existence of ultrastructural changes of alveolar capillary basal lamina in OLETF rats. GLP-1 intervention decreases the damage of alveolar capillary basal lamina in OLETF rats. Topics: Animals; Basement Membrane; Capillaries; Diabetes Mellitus, Type 2; Glucagon-Like Peptide 1; Male; Pulmonary Alveoli; Rats; Rats, Inbred OLETF | 2008 |
GLP-1 agonists facilitate hippocampal LTP and reverse the impairment of LTP induced by beta-amyloid.
Type 2 diabetes mellitus has been identified as a risk factor for Alzheimer's disease, and insulin signalling is often impaired in Alzheimer's disease, contributing to the neurodegenerative process. One potential strategy to help prevent this is the normalisation of insulin signalling in the brain. Therefore, the present study was designed to test the effects of the insulin-releasing gut hormone, glucagon-like peptide 1 (GLP-1). A protease-resistant form of GLP-1, (Val8)GLP-1, was also tested. Effects of both native GLP-1 and (Val8)GLP-1 on synaptic plasticity (LTP) in the hippocampus (15 nmol i.c.v.) were examined and results demonstrated for the first time that both peptides have enhancing effects on LTP. In sharp contrast, the inactive truncated form of GLP-1, GLP-1(9-36), had no effect on LTP. Injection of beta-amyloid (25-35) (100 nmol or 10 nmol i.c.v.), a peptide that aggregates in brains of Alzheimer's disease patients, impaired LTP. The injection of (Val8)GLP-1 (15 nmol i.c.v.) 30 min prior to injection of amyloid (25-35) (100 nmol i.c.v.) fully reversed the impairment of LTP induced by beta-amyloid. When (Val8)GLP-1 was administered 15 min prior to or simultaneously with beta-amyloid, no such reversal was observed. These results demonstrate for the first time that GLP-1 not only directly modulates neurotransmitter release and LTP formation, but also protects synapses from the detrimental effects of beta-amyloid fragments on LTP formation. Therefore, longer-acting GLP-1 agonists show great potential as a novel treatment for preventing neurodegenerative processes in neurodegenerative disorders. Topics: Amyloid beta-Peptides; Animals; Diabetes Mellitus, Type 2; Electric Stimulation; Excitatory Postsynaptic Potentials; Glucagon-Like Peptide 1; Hippocampus; Injections, Intraventricular; Long-Term Potentiation; Male; Rats; Rats, Wistar; Synaptic Transmission | 2008 |
Excessive islet NO generation in type 2 diabetic GK rats coincides with abnormal hormone secretion and is counteracted by GLP-1.
A distinctive feature of type 2 diabetes is inability of insulin-secreting beta-cells to properly respond to elevated glucose eventually leading to beta-cell failure. We have hypothesized that an abnormally increased NO production in the pancreatic islets might be an important factor in the pathogenesis of beta-cell dysfunction.. We show now that islets of type 2 spontaneous diabetes in GK rats display excessive NO generation associated with abnormal iNOS expression in insulin and glucagon cells, increased ncNOS activity, impaired glucose-stimulated insulin release, glucagon hypersecretion, and impaired glucose-induced glucagon suppression. Pharmacological blockade of islet NO production by the NOS inhibitor N(G)-nitro-L-arginine methyl ester (L-NAME) greatly improved hormone secretion from GK islets suggesting islet NOS activity being an important target to inactivate for amelioration of islet cell function. The incretin hormone GLP-1, which is used in clinical practice suppressed iNOS and ncNOS expression and activity with almost full restoration of insulin release and partial restoration of glucagon release. GLP-1 suppression of iNOS expression was reversed by PKA inhibition but unaffected by the proteasome inhibitor MG132. Injection of glucose plus GLP-1 in the diabetic rats showed that GLP-1 amplified the insulin response but induced a transient increase and then a poor depression of glucagon.. The results suggest that abnormally increased NO production within islet cells is a significant player in the pathogenesis of type 2 diabetes being counteracted by GLP-1 through PKA-dependent, nonproteasomal mechanisms. Topics: Animals; Diabetes Mellitus, Experimental; Diabetes Mellitus, Type 2; Enzyme Inhibitors; Glucagon; Glucagon-Like Peptide 1; Glucose; Insulin; Insulin Secretion; Islets of Langerhans; Male; Microscopy, Confocal; NG-Nitroarginine Methyl Ester; Nitric Oxide; Nitric Oxide Synthase Type I; Nitric Oxide Synthase Type II; Rats; Rats, Sprague-Dawley; Rats, Wistar | 2008 |
Sitagliptin phosphate: a DPP-4 inhibitor for the treatment of type 2 diabetes mellitus.
Topics: Blood Glucose; Diabetes Mellitus, Type 2; Dipeptidyl-Peptidase IV Inhibitors; Glucagon-Like Peptide 1; Humans; Pyrazines; Sitagliptin Phosphate; Sympathetic Nervous System; Treatment Outcome; Triazoles | 2008 |
Chronic administration of alogliptin, a novel, potent, and highly selective dipeptidyl peptidase-4 inhibitor, improves glycemic control and beta-cell function in obese diabetic ob/ob mice.
Dipeptidyl peptidase-4 (DPP-4) inhibitors improve glycemic control in patients with type 2 diabetes by increasing plasma active glucagon-like peptide-1 (GLP-1) and glucose-dependent insulinotropic polypeptide levels. However, the effects of chronic DPP-4 inhibition on in vivo beta-cell function are poorly characterized. We thus evaluated the chronic effects of the DPP-4 inhibitor alogliptin benzoate (formerly SYR-322) on metabolic control and beta-cell function in obese diabetic ob/ob mice. Alogliptin (0.002%, 0.01%, or 0.03%) was administered in the diet to ob/ob mice for 2 days to determine effects on plasma DPP-4 activity and active GLP-1 levels and for 4 weeks to determine chronic effects on metabolic control and beta-cell function. After 2 days, alogliptin dose-dependently inhibited DPP-4 activity by 28-82% and increased active GLP-1 by 3.2-6.4-fold. After 4 weeks, alogliptin dose-dependently decreased glycosylated hemoglobin by 0.4-0.9%, plasma glucose by 7-28% and plasma triglycerides by 24-51%, increased plasma insulin by 1.5-2.0-fold, and decreased plasma glucagon by 23-26%, with neutral effects on body weight and food consumption. In addition, after drug washout, alogliptin (0.03% dose) increased early-phase insulin secretion by 2.4-fold and improved oral meal tolerance (25% decrease in glucose area under the concentration-time curve), despite the lack of measurable plasma DPP-4 inhibition. Importantly, alogliptin also increased pancreatic insulin content up to 2.5-fold, and induced intense insulin staining of islets, suggestive of improved beta-cell function. In conclusion, chronic treatment with alogliptin improved glycemic control, decreased triglycerides, and improved beta-cell function in ob/ob mice, and may exhibit similar effects in patients with type 2 diabetes. Topics: Animals; Diabetes Mellitus, Type 2; Dipeptidyl-Peptidase IV Inhibitors; Dose-Response Relationship, Drug; Glucagon; Glucagon-Like Peptide 1; Insulin; Male; Mice; Mice, Obese; Piperidines; Triglycerides; Uracil | 2008 |
Gut hormones, incretin mimetics and gliptins: new understanding and novel therapies in type 2 diabetes.
Topics: Diabetes Mellitus, Type 2; Dipeptidyl-Peptidase IV Inhibitors; Gastric Inhibitory Polypeptide; Glucagon-Like Peptide 1; Humans; Incretins; Insulin; Insulin Secretion | 2007 |
Ectopic expression of glucagon-like peptide 1 for gene therapy of type II diabetes.
Glucagon-like peptide 1 (GLP-1) is a promising candidate for the treatment of type II diabetes. However, the short in vivo half-life of GLP-1 has made peptide-based treatments challenging. Gene therapy aimed at achieving continuous GLP-1 expression presents one way to circumvent the rapid turnover of GLP-1. We have created a GLP-1 minigene that can direct the secretion of active GLP-1 (amino acids 7-37). Plasmid and adenoviral expression vectors encoding the 31-amino-acid peptide linked to leader sequences required for secretion of GLP-1 yielded sustained levels of active GLP-1 that were significantly greater than endogenous levels. Systemic administration of expression vectors to animals using two diabetic rodent models, db/db mice and Zucker Diabetic Fatty (ZDF) rats, yielded elevated GLP-1 levels that lowered both the fasting and random-fed hyperglycemia present in these animals. Because the insulinotropic actions of GLP-1 are glucose dependent, no evidence of hypoglycemia was observed. Improved glucose homeostasis was demonstrated by improvements in %HbA1c (glycated hemoglobin) and in glucose tolerance tests. GLP-1-treated animals had higher circulating insulin levels and increased insulin immunostaining of pancreatic sections. GLP-1-treated ZDF rats showed diminished food intake and, in the first few weeks following vector administration, a diminished weight gain. These results demonstrate the feasibility of gene therapy for type II diabetes using GLP-1 expression vectors. Topics: Adenoviridae; Animals; Diabetes Mellitus, Type 2; Female; Gene Expression; Genetic Engineering; Genetic Therapy; Genetic Vectors; Glucagon-Like Peptide 1; Glucose Tolerance Test; Glycated Hemoglobin; Insulin; Insulin-Secreting Cells; Male; Mice; Mice, Inbred BALB C; Mice, Obese; Plasmids; Rats; Rats, Zucker; Transduction, Genetic; Transfection | 2007 |
Gene therapy of diabetes using a novel GLP-1/IgG1-Fc fusion construct normalizes glucose levels in db/db mice.
Glucagon-like peptide (GLP-1), a major physiological incretin, plays numerous important roles in modulating blood glucose homeostasis and has been proposed for the treatment of type 2 diabetes. The major obstacles for using native GLP-1 as a therapeutic agent are that it must be delivered by a parenteral route and has a short half-life. In an attempt to develop a strategy to prolong the physiological t(1/2) and enhance the potency of GLP-1, a fusion protein consisting of active human GLP-1 and mouse IgG(1) heavy chain constant regions (GLP-1/Fc) was generated. A plasmid encoding an IgK leader peptide-driven secretable fusion protein of the active GLP-1 and IgG(1)-Fc was constructed for mammalian expression. This plasmid allows for expression of bivalent GLP-1 peptide ligands as a result of IgG-Fc homodimerization. In vitro studies employing purified GLP-1/Fc indicate that the fusion protein is functional and elevates cAMP levels in insulin-secreting INS-1 cells. In addition, it stimulates insulin secretion in a glucose concentration-dependent manner. Intramuscular gene transfer of the plasmid in db/db mice demonstrated that expression of the GLP-1/Fc peptide normalizes glucose tolerance by enhancing insulin secretion and suppressing glucagon release. This strategy of using a bivalent GLP-1/Fc fusion protein as a therapeutic agent is a novel approach for the treatment of diabetes. Topics: Animals; Bioreactors; Blood Glucose; Cell Line; Chlorocebus aethiops; COS Cells; Cyclic AMP; Diabetes Mellitus, Type 2; Genetic Therapy; Glucagon; Glucagon-Like Peptide 1; Half-Life; Immunoglobulin Fc Fragments; Immunoglobulin G; Insulin; Mice; Mice, Obese; Models, Animal; Recombinant Fusion Proteins; Transfection | 2007 |
Evaluation of therapeutic potentials of site-specific PEGylated glucagon-like peptide-1 isomers as a type 2 anti-diabetic treatment: Insulinotropic activity, glucose-stabilizing capability, and proteolytic stability.
PEGylation has been considered to be a good biotechnique for improving the therapeutic value of glucagon-like peptide-1 (GLP-1) analogs for the treatment of type 2 diabetes. Despite the attractive anti-diabetic potentials, GLP-1 does not exert its full biological action because of its extremely short life-time in vivo due to rapid proteolytic degradation. Here, the enzyme-resistant mono-PEGylated GLP-1 isomers substituted at Lys(26)- or Lys(34)-amine were prepared through a newly devised site-specific PEGylation process using a maleic anhydride-protection/deprotection method. The therapeutic potentials of these site-specific PEGylated GLP-1 isomers (Lys(26)- or Lys(34)-PEG-GLP-1) along with His(7)-(N-terminus) PEG-GLP-1 were evaluated by examining their insulinotropic activity, glucose-stabilizing capability, and proteolytic stability. Lys(34)-PEG-GLP-1 was found to have the well-preserved insulinotropic activity (93% efficacy versus GLP-1) in isolated rat pancreatic islets. Furthermore, Lys(34)-PEG-GLP-1 showed the most prominent glucose-stabilizing capability, evaluated via an oral glucose tolerance test in db/db mice by considering the following three crucial factors: (i) maximum blood glucose level (BGL), (ii) required time to lower the BGL below 100mg/dl, and (iii) total hypoglycemic degree. Additionally, Lys(34)-PEG-GLP-1 had longer half-lives than the other PEGylated GLP-1s in the dipeptidyl peptidase IV (DPP IV) inhibitor-treated liver or kidney homogenate, and its stability against DPP IV was also comparable to that of Lys(26)-PEG-GLP-1. Taken together, Lys(34)-PEG-GLP-1 displayed the promising characteristics in all evaluations versus His(7)- or Lys(26)-PEG-GLP-1. This site-specific PEGylated GLP-1 analog would have therapeutic usefulness for treating type 2 diabetes on account of the well-preserved insulinotropic activity, the increased proteolytic stability, and thereby the improved glucose-stabilizing capability. Topics: Animals; Blood Glucose; Diabetes Mellitus, Type 2; Drug Evaluation, Preclinical; Glucagon-Like Peptide 1; Hydrolysis; Hypoglycemic Agents; Male; Mice; Mice, Inbred C57BL; Polyethylene Glycols; Rats; Rats, Sprague-Dawley | 2007 |
Sitagliptin (Januvia) for type 2 diabetes.
Topics: Adenosine Deaminase; Adenosine Deaminase Inhibitors; Blood Glucose; Diabetes Mellitus, Type 2; Dipeptidyl Peptidase 4; Dipeptidyl-Peptidase IV Inhibitors; Drug Therapy, Combination; Gastric Inhibitory Polypeptide; Glucagon-Like Peptide 1; Glycated Hemoglobin; Glycoproteins; Humans; Hypoglycemic Agents; Insulin-Secreting Cells; Protease Inhibitors; Pyrazines; Randomized Controlled Trials as Topic; Sitagliptin Phosphate; Treatment Outcome; Triazoles | 2007 |
Inappropriate suppression of glucagon during OGTT but not during isoglycaemic i.v. glucose infusion contributes to the reduced incretin effect in type 2 diabetes mellitus.
We investigated glucagon responses during OGTT and isoglycaemic i.v. glucose infusion, respectively, to further elucidate the mechanisms behind the glucose intolerance in patients with type 2 diabetes.. Ten patients (eight men) with type 2 diabetes (age: 64 [51-80] years; BMI: 23 [21-26] kg/m(2); HbA(1c): 6.9 [6.2-8.7]%, values mean [range]) and ten control subjects matched for sex, age and BMI were studied. Blood was sampled on two separate days following a 4-h 50-g OGTT and an isoglycaemic i.v. glucose infusion, respectively.. Isoglycaemia during the 2 days was obtained in both groups. In the control subjects no difference in glucagon suppression during the first 45 min of OGTT and isoglycaemic i.v. glucose infusion (-36 +/- 12 vs -64 +/- 23 mmol/l x 45 min; p = NS) was observed, whereas in the group of patients with type 2 diabetes significant glucagon suppression only occurred following isoglycaemic i.v. glucose infusion (-63 +/- 21 vs 10 +/- 16 mmol/l x 45 min; p = 0.002). The incretin effect was significantly reduced in patients with type 2 diabetes compared with control subjects, but no significant differences in the secretion of glucagon-like peptide-1 or glucose-dependent insulinotropic polypeptide between the two groups during OGTT or isoglycaemic i.v. glucose infusion, respectively, could explain this.. Attenuated and delayed glucagon suppression in patients with type 2 diabetes occurs after oral ingestion of glucose, while isoglycaemic i.v. administration of glucose results in normal suppression of glucagon. We suggest that this phenomenon contributes both to the glucose intolerance and to the reduced incretin effect observed in patients with type 2 diabetes. Topics: Adult; Aged; Aged, 80 and over; Case-Control Studies; Diabetes Mellitus, Type 2; Female; Glucagon; Glucagon-Like Peptide 1; Glucose; Glucose Tolerance Test; Humans; Insulin; Male; Middle Aged; Time Factors | 2007 |
Finding new treatments for diabetes--how many, how fast... how good?
Topics: Adenosine Deaminase Inhibitors; Clinical Trials as Topic; Diabetes Mellitus, Type 2; Dipeptidyl Peptidase 4; Dipeptidyl-Peptidase IV Inhibitors; Drug Approval; Glucagon-Like Peptide 1; Glycoproteins; History, 20th Century; History, 21st Century; Humans; Hypoglycemic Agents; Peptide Fragments; Pyrazines; Sitagliptin Phosphate; Triazoles; United States; United States Food and Drug Administration | 2007 |
Biological activity of AC3174, a peptide analog of exendin-4.
Exenatide, the active ingredient of BYETTA (exenatide injection), is an incretin mimetic that has been developed for the treatment of patients with type 2 diabetes. Exenatide binds to and activates the known GLP-1 receptor with a potency comparable to that of the mammalian incretin GLP-1(7-36), thereby acting as a glucoregulatory agent. AC3174 is an analog of exenatide with leucine substituted for methionine at position 14, [Leu(14)]exendin-4. The purpose of these studies was to evaluate the glucoregulatory activity and pharmacokinetics of AC3174. In RINm5f cell membranes, the potency of AC3174 for the displacement of [(125)I]GLP-1 and activation of adenylate cyclase was similar to that of exenatide and GLP-1. In vivo, AC3174, administered as a single IP injection, significantly decreased plasma glucose concentration and glucose excursion following the administration of an oral glucose challenge in both non-diabetic (C57BL/6) and diabetic db/db mice (P<0.05 vs. vehicle-treated). The magnitude of glucose lowering of AC3174 was comparable to exenatide. The ED(50) values of AC3174 for glucose lowering (60 minute post-dose) were 1.2 microg/kg in db/db mice and 1.3 microg/kg in C57BL/6 mice. AC3174 has insulinotropic activity in vivo. Administration of AC3174 resulted in a 4-fold increase in insulin concentrations in normal mice following an IP glucose challenge. AC3174 was also shown to inhibit food intake and decrease gastric emptying in rodent models. AC3174 was stable in human plasma (>90% of parent peptide was present after 5 h of incubation). In rats, the in vivo half-life of AC3174 was 42-43 min following SC administration. In summary, AC3174 is an analog of exenatide that binds to the GLP-1 receptor in vitro and shares many of the biological and glucoregulatory activities of exenatide and GLP-1 in vivo. Topics: Adenylyl Cyclases; Animals; Blood Glucose; Cell Line, Tumor; Cell Membrane; Diabetes Mellitus, Type 2; Drug Stability; Eating; Enzyme Activation; Exenatide; Gastric Emptying; Glucagon-Like Peptide 1; Glucose; Glucose Tolerance Test; Half-Life; Humans; Hypoglycemic Agents; Injections, Intraperitoneal; Injections, Subcutaneous; Insulin; Male; Mice; Mice, Inbred C57BL; Mice, Mutant Strains; Peptides; Rats; Rats, Sprague-Dawley; Venoms | 2007 |
Preserved GLP-1 effects in a diabetic patient with Cushing's disease.
A patient with diabetes mellitus, who participated in a study with intravenous administration of GLP-1, was later found to have Cushing's disease (markedly elevated 24 h urinary cortisol excretion and inadequate suppression of fasting cortisol with 2 mg dexamethasone). His diabetic state disappeared (2 h plasma glucose after 75 g oral glucose 159 mg/dl=IGT) after successful pituitary surgery (normal 24 h urinary cortisol excretion and adequate cortisol suppression with 2 mg dexamethasone).. The present analysis was undertaken to compare GLP-1 actions on fasting glycemia in diabetes mellitus due to Cushing's disease with GLP-1 actions in typical type 2 diabetes.. GLP-1 (1.2 pmol/kg/min) and placebo had been infused into ten patients with diabetes mellitus over 4 h in the fasting state. The results from the patient with Cushing's disease (C) were compared to the data from the remaining nine patients with type 2 diabetes (D).. Within 4 h glucose decreased from basal (C: 12.9; D: 12.9+/-0.7 mmol/l) to normal fasting values (C: 5.0; D: 4.9+/-0.4 mmol/l). The stimulation of insulin secretion and suppression of glucagon secretion was similar in the patient with Cushing's disease compared to those with type 2 diabetes.. The insulinotropic, glucagonostatic and glucose-lowering actions of GLP-1 in a patient with diabetes mellitus due to cortisol excess were similar to actions in typical type 2 diabetes. Therefore incretin mimetics might be a novel therapeutic strategy for the treatment of glucocorticoid-induced diabetes mellitus. Topics: Blood Glucose; Diabetes Mellitus, Type 2; Female; Glucagon-Like Peptide 1; Humans; Hydrocortisone; Insulin; Male; Middle Aged; Pituitary ACTH Hypersecretion | 2007 |
Awareness of pathophysiological concepts of type 2 diabetes: a survey in 847 physicians.
The aim of the study was to determine physicians' knowledge of specific concepts generally implicated in the pathophysiology of type 2 diabetes (T2D).. A multiple choice online survey was completed by 847 physicians, of which 516 were engaged in primary care (PCP) and 331 in specialized care (SCP) in the US, the UK, Germany and France (3-30 years in practice, at least 40 patients with T2D). A continuous rating system was used to measure familiarity ("totally familiar" to "never heard of") or agreement with a statement (from "totally agree" to "totally disagree").. The term "insulin resistance" was recognized by 74% of PCPs and 90% of SCPs (p<0.05) and 76% felt that it was "a key but not the sole determinant of T2D". Only 47% agreed that "beta cell dysfunction is a key determinant of T2D onset" and 57% agreed with "beta cell dysfunction being a key determinant of T2D progression". Even among SCPs, 6% were not familiar with the term "beta cell dysfunction" (16% among PCPs, p<0.05). The overall familiarity with the following terms was: 55% with "beta cell dysfunction", 56% with "beta cells", 38% with "glucagon", 32% with "alpha cells", 55% with "hepatic glucose output", 15% with "incretins" and 18% with "GLP-1". SCPs were significantly more familiar with all terms than PCPs (all p-values <0.05).. The pathogenetic role of beta cell dysfunction in the onset and progression of T2D did not seem to be well established. "Insulin resistance" was a well known concept even among PCPs, while "hepatic glucose output", "pancreatic alpha cells" and "glucagon" were not. Incretin hormones and GLP-1 were widely unknown. This may effect prescribing behaviour and how well an individual's therapy is based on pathophysiology. Topics: Clinical Competence; Diabetes Mellitus, Type 2; Family Practice; Glucagon; Glucagon-Like Peptide 1; Glucagon-Secreting Cells; Glucose; Humans; Insulin Resistance; Insulin-Secreting Cells; Liver; Online Systems; Primary Health Care; Surveys and Questionnaires | 2007 |
Suppression of glucagon secretion is lower after oral glucose administration than during intravenous glucose administration in human subjects.
The incretin effect describes the augmentation of postprandial insulin secretion by gut hormones. It is not known whether glucagon secretion is also influenced by an incretin effect. A glucagon suppression deficiency has been reported in some patients with type 2 diabetes, but it is unclear whether this abnormality is present prior to diabetes onset. We therefore addressed the questions: (1) Is glucagon secretion different after oral and during intravenous glucose administration? (2) If so, is this related to the secretion of incretin hormones? (3) Is glucagon secretion abnormal in first-degree relatives of patients with type 2 diabetes?. We examined 16 first-degree relatives of patients with type 2 diabetes and ten matched control subjects with an oral glucose load (75 g) and with an 'isoglycaemic' intravenous glucose infusion.. Glucagon levels were significantly suppressed by both oral and intravenous glucose (p < 0.0001), but glucagon suppression was more pronounced during intravenous glucose administration (76 +/- 2%) than after oral glucose administration (48 +/- 4%; p < 0.001). The differences in the glucagon responses to oral and i.v. glucose were correlated with the increments in gastric inhibitory polypeptide (GIP) (r = 0.60, p = 0.001) and glucagon-like peptide (GLP)-1 (r = 0.46, p < 0.05). There were no differences in glucagon levels between first-degree relatives and control subjects.. Despite the glucagonostatic actions of GLP-1, the suppression of glucagon secretion by glucose is diminished after oral glucose ingestion, possibly due to the glucagonotropic actions of GIP and GLP-2. Furthermore, in this group of first-degree relatives, abnormalities in glucagon secretion did not precede the development of other defects, such as impaired insulin secretion. Topics: Administration, Oral; Adult; Cohort Studies; Diabetes Mellitus, Type 2; Female; Gastric Inhibitory Polypeptide; Glucagon; Glucagon-Like Peptide 1; Glucose; Humans; Infusions, Intravenous; Insulin; Male; Middle Aged; Time Factors | 2007 |
Incretin mimetics vie for slice of type 2 diabetes market.
Topics: Adenosine Deaminase Inhibitors; Diabetes Mellitus, Type 2; Dipeptidyl Peptidase 4; Dipeptidyl-Peptidase IV Inhibitors; Drug Design; Drug Industry; Glucagon-Like Peptide 1; Glycoproteins; Humans | 2007 |
Incretin levels and effect are markedly enhanced 1 month after Roux-en-Y gastric bypass surgery in obese patients with type 2 diabetes.
Limited data on patients undergoing Roux-en-Y gastric bypass surgery (RY-GBP) suggest that an improvement in insulin secretion after surgery occurs rapidly and thus may not be wholly accounted for by weight loss. We hypothesized that in obese patients with type 2 diabetes the impaired levels and effect of incretins changed as a consequence of RY-GBP.. Incretin (gastric inhibitory peptide [GIP] and glucagon-like peptide-1 [GLP-1]) levels and their effect on insulin secretion were measured before and 1 month after RY-GBP in eight obese women with type 2 diabetes and in seven obese nondiabetic control subjects. The incretin effect was measured as the difference in insulin secretion (area under the curve [AUC]) in response to an oral glucose tolerance test (OGTT) and to an isoglycemic intravenous glucose test.. Fasting and stimulated levels of GLP-1 and GIP were not different between control subjects and patients with type 2 diabetes before the surgery. One month after RY-GBP, body weight decreased by 9.2 +/- 7.0 kg, oral glucose-stimulated GLP-1 (AUC) and GIP peak levels increased significantly by 24.3 +/- 7.9 pmol x l(-1) x min(-1) (P < 0.0001) and 131 +/- 85 pg/ml (P = 0.007), respectively. The blunted incretin effect markedly increased from 7.6 +/- 28.7 to 42.5 +/- 11.3 (P = 0.005) after RY-GBP, at which it time was not different from that for the control subjects (53.6 +/- 23.5%, P = 0.284).. These data suggest that early after RY-GBP, greater GLP-1 and GIP release could be a potential mediator of improved insulin secretion. Topics: Adult; Diabetes Mellitus, Type 2; Female; Gastric Bypass; Gastric Inhibitory Polypeptide; Glucagon-Like Peptide 1; Humans; Insulin; Laparoscopy; Middle Aged; Obesity; Postoperative Period | 2007 |
Bariatric surgery provides unparalleled metabolic benefits.
Topics: Bariatric Surgery; Diabetes Mellitus, Type 2; Glucagon-Like Peptide 1; Humans; Metabolic Syndrome; Obesity | 2007 |
Bariatric surgery provides unparalleled metabolic benefits.
Topics: Bariatric Surgery; Diabetes Mellitus, Type 2; Glucagon-Like Peptide 1; Humans; Metabolic Syndrome; Obesity | 2007 |
Comparison of efficacies of a dipeptidyl peptidase IV inhibitor and alpha-glucosidase inhibitors in oral carbohydrate and meal tolerance tests and the effects of their combination in mice.
E3024 (3-but-2-ynyl-5-methyl-2-piperazin-1-yl-3,5-dihydro-4H-imidazo[4,5-d]pyridazin-4-one tosylate) is a dipeptidyl peptidase IV (DPP-IV) inhibitor. Since the target of both DPP-IV inhibitors and alpha-glucosidase inhibitors is the lowering of postprandial hyperglycemia, we compared antihyperglycemic effects for E3024 and alpha-glucosidase inhibitors in various oral carbohydrate and meal tolerance tests using normal mice. In addition, we investigated the combination effects of E3024 and voglibose on blood glucose levels in a meal tolerance test using mice fed a high-fat diet. ER-235516-15 (the trifluoroacetate salt form of E3024, 1 mg/kg) lowered glucose excursions consistently, regardless of the kind of carbohydrate loaded. However, the efficacy of acarbose (10 mg/kg) and of voglibose (0.1 mg/kg) varied with the type of carbohydrate administered. The combination of E3024 (3 mg/kg) and voglibose (0.3 mg/kg) improved glucose tolerance additively, with the highest plasma active glucagon-like peptide-1 levels. This study shows that compared to alpha-glucosidase inhibitors, DPP-IV inhibitors may have more consistent efficacy to reduce postprandial hyperglycemia, independent of the types of carbohydrate contained in a meal, and that the combination of a DPP-IV inhibitor and an alpha-glucosidase inhibitor is expected to be a promising option for lowering postprandial hyperglycemia. Topics: Acarbose; Administration, Oral; Animals; Area Under Curve; Blood Glucose; Carbohydrate Metabolism; Diabetes Mellitus, Type 2; Dietary Sucrose; Dipeptidyl-Peptidase IV Inhibitors; Drug Therapy, Combination; Enzyme Inhibitors; Food, Formulated; Glucagon-Like Peptide 1; Glucose Tolerance Test; Glycoside Hydrolase Inhibitors; Hyperglycemia; Hypoglycemic Agents; Imidazoles; Injections, Intravenous; Inositol; Insulin; Male; Mice; Mice, Inbred C57BL; Postprandial Period; Pyridazines; Tosyl Compounds | 2007 |
Reduced incretin effect in type 2 diabetes: cause or consequence of the diabetic state?
We aimed to investigate whether the reduced incretin effect observed in patients with type 2 diabetes is a primary event in the pathogenesis of type 2 diabetes or a consequence of the diabetic state. Eight patients with chronic pancreatitis and secondary diabetes (A1C mean [range] of 6.9% [6.2-8.0]), eight patients with chronic pancreatitis and normal glucose tolerance (NGT; 5.3 [4.9-5.7]), eight patients with type 2 diabetes (6.9 [6.2-8.0]); and eight healthy subjects (5.5 [5.1-5.8]) were studied. Blood was sampled over 4 h on 2 separate days after a 50-g oral glucose load and an isoglycemic intravenous glucose infusion, respectively. The incretin effect (100% x [beta-cell secretory response to oral glucose tolerance test - intravenous beta-cell secretory response]/beta-cell secretory response to oral glucose tolerance test) was significantly (P < 0.05) reduced (means +/- SE) in patients with chronic pancreatitis and secondary diabetes (31 +/- 4%) compared with patients with chronic pancreatitis and NGT (68 +/- 3) and healthy subjects (60 +/- 4), respectively. In the type 2 diabetes group, the incretin effect amounted to 36 +/- 6%, significantly (P < 0.05) lower than in chronic pancreatitis patients with NGT and in healthy subjects, respectively. These results suggest that the reduced incretin effect is not a primary event in the development of type 2 diabetes, but rather a consequence of the diabetic state. Topics: Adult; Aged; Blood Glucose; C-Peptide; Diabetes Mellitus, Type 2; Female; Gastric Inhibitory Polypeptide; Glucagon; Glucagon-Like Peptide 1; Glutaminase; Homeostasis; Humans; Insulin; Insulin Secretion; Intracellular Signaling Peptides and Proteins; Male; Middle Aged; Models, Biological | 2007 |
[Glucagon-like peptide 1 in the treatment of patients with type 2 diabetes].
Topics: Diabetes Mellitus, Type 2; Glucagon-Like Peptide 1; Humans | 2007 |
[Glucagon-like peptide-1 (GLP-1), new target for the treatment of type 2 diabetes].
Glucagon-like peptide-1 (GLP-1) is a gut hormone secreted in response to the ingestion of a meal. It exerts various favourable metabolic effects among which a glucose-dependent stimulation of insulin secretion, an inhibition of glucagon secretion, a slow down of gastric emptying, and a central anorectic effect. In rodents, a protective effect, or even a trophic effect, on B cell has also been reported. Interestingly, GLP-1 secretion is decreased in patients with type 2 diabetes. This observation stimulated the pharmaceutical research with the aim of restoring appropriate GLP-1 circulating levels able to exert the numerous positive effects of the hormone. One of the main objectives was to solve the problem due to the very short half-life of GLP-1. We here briefly describe the main two proposed approaches : ether to subcutaneously inject an incretinomimetic agent closed to GLP-1 (exenatide) or a long-acting GLP-1 analogue (liraglutide), both being partially resistant to the action of dipeptidylpeptidase-IV (DPP-IV), either to orally administer a selective DPP-IV inhibitor, an enzyme metabolising endogenous GLP-1 (sitagliptin, vildagliptin, .... These new drugs offer the advantage of improving blood glucose control of type 2 diabetic patients, without inducing severe hypoglycaemia and without promoting weight gain (instead a weight reduction is generally observed). These agents should occupy a key place in the overall pharmacological strategy of type 2 diabetes in a near future, especially if the additional favourable effects on B cells are confirmed in clinical practice. Topics: Adamantane; Animals; Appetite; Blood Glucose; Diabetes Mellitus, Type 2; Dipeptidyl-Peptidase IV Inhibitors; Exenatide; Gastric Emptying; Glucagon; Glucagon-Like Peptide 1; Humans; Hypoglycemic Agents; Insulin; Insulin Secretion; Liraglutide; Nitriles; Peptides; Pyrazines; Pyrrolidines; Sitagliptin Phosphate; Triazoles; Venoms; Vildagliptin | 2007 |
Increase in DPP-IV in the intestine, liver and kidney of the rat treated with high fat diet and streptozotocin.
High fat diet or insulin deficiency is commonly seen in Type II diabetes, while the mechanism remains unclear. To test our hypothesis that DPP-IV contributes to Type II diabetes, we examined the expression and activity of DPP-IV in rats (n=8 to each group) treated for 12 weeks with 3 separate diets: a) normal control; b) a high fat diet; and c) a high fat diet plus streptozotocin, a chemical for induction of insulin-deficient diabetes. Compared to rats on the normal diet, the rats with a high fat diet significantly increased DPP-IV's expression and activity about 142-152% in the intestine (P<0.05) and 153-240% in kidneys (P<0.05), but there was no change in the liver. Administration of streptozotocin to the rats treated with the high fat diet showed an insufficient insulin secretion and higher blood glucose in response to glucose/insulin tolerance test, and an increase in expression of DPP-IV and activity by 188-242% in the intestine (P<0.01); 191-225% in liver (P<0.01); and 211-321% in the kidneys (P<0.01). Immunohistochemistry studies confirmed the above results, showing increased DPP-IV immunostaining localized primarily in intestinal epithelium, hepatocytes and renal tubular cells. This study, for the first time reports an increase in DPP-IV associated with a high fat diet, as well as in the combination of a high fat diet with an insulin deficiency. Since both high fat diet and insulin deficiency are closely linked with etiology of Type II diabetes, the evidence in this study suggests a role of DPP-IV in development of Type II diabetes. Topics: Animals; Blood Glucose; Diabetes Mellitus, Experimental; Diabetes Mellitus, Type 2; Dietary Fats; Dipeptidyl Peptidase 4; Disease Models, Animal; Enzyme Inhibitors; Gene Expression Regulation, Enzymologic; Glucagon-Like Peptide 1; Glucose Intolerance; Humans; Immunohistochemistry; Insulin; Intestines; Kidney; Lipids; Liver; Rats; Rats, Sprague-Dawley; RNA, Messenger; Streptozocin | 2007 |
The effects of duodenal-jejunal exclusion on hormonal regulation of glucose metabolism in Goto-Kakizaki rats.
The antidiabetic effect of bariatric surgery has been interpreted as a conceivable result of surgically induced weight loss and decreased caloric intake. However, glycemic control often occurs within days, before significant weight loss has been reached. The aim of our work was to investigate the hormones that control glycemic status in diabetes mellitus after a duodenal-jejunal exclusion in an animal model of nonobese type 2 diabetes.. Twelve (12- to 14-week-old) rats (Goto-Kakizaki) randomly underwent one of the following procedures: gastrojejunal bypass (group 1, n = 6) or no intervention (controls) (group 2, n = 6). Both groups were fed with the same type and amount of diet. At basal time (preoperative) and after intervention (1 week and 1 month), weight and fasting glycemia were measured. An oral glucose tolerance test (OGTT) was realized at same times. Hormone levels (insulin, glucagons-like peptide 1 [GLP-1], glucose-dependent insulinotropic peptide [GIP], glucagon, and leptin) were measured after 20 minutes of oral glucose overload. Age-matched Goto-Kakizaki rats were used as controls for all variables.. Rats in group 1 and group 2 remained with the same weight during the protocol. The OGTT showed an improvement in glycemic levels in group 1; glucose levels were better at 1 week and 1 month after the surgery in all times of OGTT (basal, 10 minutes, and 120 minutes). Basal glucose levels at time 0 in basal time, at 1 week, and at 1 month were lower in group 1 than group 2. Postoral glucose overload levels of glucagon, insulin, GLP-1, and GIP remained unchanged during the treatment in both groups. In group 1, leptin levels had a significant decrease at 1 week and 1 month after surgery (basal time (6.1 +/- 1.6 ng/mL) versus 1 week (0.9 +/- 0.9 ng/mL) versus 1 month (0.7 +/- 0.6 ng/mL) (P < .05).. Gastrojejunal bypass in a nonobese diabetic model improves glycemic control with a significant decrease in leptin levels, without changes in enteroinsular axis (GLP-1, GIP, glucagons, and insulin levels). Topics: Animals; Blood Glucose; Diabetes Mellitus, Type 2; Disease Models, Animal; Gastric Bypass; Gastric Inhibitory Polypeptide; Glucagon; Glucagon-Like Peptide 1; Glucose Tolerance Test; Homeostasis; Insulin; Leptin; Male; Rats; Rats, Inbred Strains | 2007 |
How the hindgut can cure type 2 diabetes. Ileal transposition improves glucose metabolism and beta-cell function in Goto-kakizaki rats through an enhanced Proglucagon gene expression and L-cell number.
It has been hypothesized that glucagon-like peptide-1 (GLP-1), secreted by ileal L cells, plays a key-role in the resolution of type 2 diabetes after bariatric operations whose common feature is an expedite nutrient delivery to the hindgut. Ileal transposition (IT), an operation that permits L-cell stimulation by undigested food, was employed to verify this theory.. IT was carried out in Goto-Kakizaki (GK) type 2 diabetic rats and in euglycemic Sprague-Dawley (SD) rats. Glucose tolerance, insulin resistance, food-intake, body weight, pancreas morphology, and function were evaluated to track the effects of IT on diabetes. Intact GLP-1 secretion and gene expression pattern of the transposed ileum were investigated to verify the molecular bases of the hindgut action.. In GK rats, IT significantly improved glucose tolerance, insulin sensitivity, and acute insulin response without affecting body weight and food intake. Immunohistochemistry revealed remodeled islets strictly resembling that of euglycemic rats and signs of beta-cell neogenesis starting with exocrine structures. GLP-1 secretion in GK transposed rats was characterized by a more sustained response to oral glucose compared with nontreated rats. Gene expression of Proglucagon, Proconvertase 1/3 (PC1/3), and Chromogranin A in the transposed ileum significantly enhanced. Effects on glucose metabolism and pancreas morphology were not observed in the euglycemic rats as a consequence of the glucose-dependent action of GLP-1.. This study gives strong evidences for the crucial role of the hindgut in the resolution of diabetes after Roux-en-Y gastric bypass (GBP) and biliopancreatic diversion (BPD). Moreover, these findings confirm at the preclinical level that IT is a surgical procedure of possible relevance in the therapy of type 2 diabetes in non-overweight and mildly obese patients. Topics: Administration, Oral; Animals; Blood Glucose; Chromogranin A; Diabetes Mellitus, Type 2; Eating; Enteroendocrine Cells; Gene Expression; Glucagon-Like Peptide 1; Glucose; Glucose Tolerance Test; Ileum; Insulin Resistance; Insulin-Secreting Cells; Proglucagon; Proprotein Convertase 1; Rats; Rats, Inbred Strains; Rats, Sprague-Dawley; RNA, Messenger; Weight Gain | 2007 |
Editorial: The role of glucagon in postprandial hyperglycemia--the jury's still out.
Topics: Blood Glucose; C-Peptide; Child; Diabetes Mellitus, Type 1; Diabetes Mellitus, Type 2; Glucagon; Glucagon-Like Peptide 1; Glucagon-Secreting Cells; Glycated Hemoglobin; Humans; Hyperglycemia; Insulin; Postprandial Period; Potassium Channel Blockers; Potassium Channels, Inwardly Rectifying; Sulfonylurea Compounds | 2007 |
Attenuation of insulin secretion by insulin-like growth factor binding protein-1 in pancreatic beta-cells.
IGFBP-1 is involved in glucohomeostasis, but the direct action of IGFBP-1 on the beta-cell remains unclear. Incubation of dispersed mouse beta-cells with IGFBP-1 for 30min inhibited insulin secretion stimulated by glucose, glucagon-like peptide 1 (GLP-1) or tolbutamide without changes in basal release of insulin and in cytosolic free Ca(2+) concentration ([Ca(2+)](i)) and NAD(P)H evoked by glucose. In contrast, IGFBP-1 augmented glucose-stimulated insulin secretion in intact islets, associated with a reduced somatostatin secretion. These results suggest a suppressive action of IGFBP-1 on insulin secretion in isolated beta-cells through a mechanism distal to energy generating steps and not involving regulation of [Ca(2+)](i). In contrast, IGFBP-1 amplifies glucose-stimulated insulin secretion in intact islets, possibly by suppressing somatostatin secretion. These direct modulatory influences of IGFBP-1 on insulin secretion may imply an important regulatory role of IGFBP-1 in vivo and in the pathogenesis of type 2 diabetes, in which loss of insulin release is an early pathogenetic event. Topics: Animals; Calcium; Cytosol; Diabetes Mellitus, Type 2; Exocytosis; Glucagon-Like Peptide 1; Glucose; Insulin; Insulin Secretion; Insulin-Like Growth Factor Binding Protein 1; Insulin-Secreting Cells; Mice; Mice, Obese; Models, Biological; NADP; Somatostatin | 2007 |
Structural studies of a bifunctional inhibitor of neprilysin and DPP-IV.
Neutral endopeptidase (NEP) is the major enzyme involved in the metabolic inactivation of a number of bioactive peptides including the enkephalins, substance P, endothelin, bradykinin and atrial natriuretic factor, as well as the incretin hormone glucagon-like peptide 1 (GLP-1), which is a potent stimulator of insulin secretion. The activity of GLP-1 is also rapidly abolished by the serine protease dipeptidyl peptidase IV (DPP-IV), which led to an elevated interest in inhibitors of this enzyme for the treatment of type II diabetes. A dual NEP/DPP-IV inhibitor concept is proposed, offering an alternative strategy for the treatment of type 2 diabetes. Here, the synthesis and crystal structures of the soluble extracellular domain of human NEP (residues 52-749) complexed with the NEP, competitive and potent dual NEP/DPP-IV inhibitor MCB3937 are described. Topics: Adenosine Deaminase; Adenosine Deaminase Inhibitors; Binding, Competitive; Crystallography, X-Ray; Diabetes Mellitus, Type 2; Dipeptidyl Peptidase 4; Dipeptidyl-Peptidase IV Inhibitors; Glucagon-Like Peptide 1; Glycoproteins; Humans; Models, Molecular; Molecular Structure; Neprilysin; Oligopeptides; Peptide Fragments; Protein Binding; Protein Structure, Tertiary; Zinc | 2007 |
[Glucagon-like peptide 1 (GLP-1)].
GLP-1 receptor agonists such as exenatide are a group of new therapeutic agents that mimic the gut-derived incretin hormone GLP-1. These drugs stimulate insulin secretion while suppressing glucagon secretion, inhibit gastric motility, reduce appetite and hence, food intake. This group of drugs also induce reduction in fasting and postprandial glucose concentrations, HbA1c and ultimately lead to weight loss. The drugs are administered subcutaneously (exenatide twice daily). The most common side effect is mild nausea. Although short-term studies are promising, long-term clinical studies are needed to determine the benefits of this approach for the treatment of type 2 diabetes. Topics: Blood Glucose; Clinical Trials as Topic; Delayed-Action Preparations; Diabetes Mellitus, Type 2; Drug Therapy, Combination; Exenatide; Glucagon-Like Peptide 1; Humans; Hypoglycemic Agents; Injections, Subcutaneous; Insulin; Liraglutide; Peptides; Venoms | 2007 |
Gastric emptying controls type 2 diabetes mellitus.
Topics: Diabetes Mellitus, Type 2; Gastric Emptying; Glucagon-Like Peptide 1; Humans; Obesity | 2007 |
Reproducible production of a PEGylated dual-acting peptide for diabetes.
A PEGylated glucagon-like peptide-1 (GLP-1) agonist and glucagon antagonist hybrid peptide was engineered as a potential treatment for type 2 diabetes. To support preclinical development of this PEGylated dual-acting peptide for diabetes (DAPD), we developed a reproducible method for PEGylation, purification, and analysis. Optimal conditions for site-specific PEGylation with 22 and 43 kDa maleimide-polyethylene glycol (maleimide-PEG) polymers were identified by evaluating pH, reaction time, and reactant molar ratio parameters. A 3-step purification process was developed and successfully implemented to purify PEGylated DAPD and remove excess uncoupled PEG and free peptide. Five lots of 43 kDa PEGylated DAPD with starting peptide amounts of 100 mg were produced with overall yields of 53% to 71%. Analytical characterization by N-terminal sequencing, amino acid analysis, matrix-assisted laser desorption/ionization mass spectrometry, and GLP-1 receptor activation assay confirmed site-specific attachment of PEG at the engineered cysteine residue, expected molecular weight, correct amino acid sequence and composition, and consistent functional activity. Purity and safety analysis by sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE), analytical ion-exchange chromatography, reversed-phase high-performance liquid chromatography, and limulus amebocyte lysate test showed that the final products contained <1% free peptide, <5% uncoupled PEG, and <0.2 endotoxin units per milligram of peptide. These results demonstrate that the PEGylation and purification process we developed was consistent and effective in producing PEGylated DAPD preclinical materials at the 100 mg (peptide weight basis) or 1.2 g (drug substance weight basis) scale. Topics: Animals; Cell Line, Tumor; Diabetes Mellitus, Type 2; Drug Design; Glucagon-Like Peptide 1; Hypoglycemic Agents; Peptides; Polyethylene Glycols; Rats | 2007 |
Adverse effects of incretin therapy for type 2 diabetes.
Topics: Diabetes Mellitus, Type 2; Dipeptidyl Peptidase 4; Dipeptidyl-Peptidase IV Inhibitors; Glucagon-Like Peptide 1; Humans; Hypoglycemic Agents; Inflammation; Nasopharyngitis; Substance P | 2007 |
[The incretin effect: a new therapeutic target in type 2 diabetes].
The two incretin hormones GLP-1 (Glucagon-Like Peptide-1) and GIP (Glucose-dependent Insulinotropic Peptide) are released by the gut in response to nutrient ingestion. Both of them potentiate glucose-induced insulin response, enhance insulin biosynthesis and, at least in rodents, preserve beta-cell mass through reduction of apoptosis and stimulation of beta-cell proliferation. In addition to its insulinotropic action, GLP-1 (but not GIP) suppresses glucagon secretion, delays gastric emptying and promotes satiety. Since in type 2 diabetes, the secretion of GLP-1 is dramatically reduced whereas its effects are retained, a number of pharmacological strategies aiming at restoring the incretin activity of this peptide have been explored. Because GLP-1 is rapidly degraded by the ubiquitous enzyme, dipeptidyl peptidase-IV (DPP-IV) and has a very short-lived action, DPP-IV resistant mimetics have been designed. Several randomized placebo-controlled studies with DPP-IV resistant GLP-1 analogues confirmed their efficacy to improve glycemic control in type 2 diabetic patients. The first one, exenatide, has been approved by the Food and Drug Administration (FDA) in 2005 for the treatment of type 2 diabetes. Longer-acting mimetics requiring only one injection per day or even per week are currently assessed in phase 3 trials. Another successful approach has been the development of orally active DPP-IV inhibitors which reversibly and selectively block the enzymatic activity. Many small-molecule DPP-IV inhibitors, called gliptins, have been shown to be effective as antihyperglycemic agents and, up to now, devoid of major adverse events. The first drug of this new therapeutic class having received FDA approval, sitagliptin, is now available for the treatment of type 2 diabetes in U.S. However, the efficacy/safety profile of these compounds and their positioning in the therapeutic algorithm of type 2 diabetes remains to be defined. Topics: Diabetes Mellitus, Type 2; Dipeptidyl Peptidase 4; Dipeptidyl-Peptidase IV Inhibitors; Enzyme Inhibitors; Gastric Inhibitory Polypeptide; Glucagon-Like Peptide 1; Humans | 2007 |
Colestimide lowers plasma glucose levels and increases plasma glucagon-like PEPTIDE-1 (7-36) levels in patients with type 2 diabetes mellitus complicated by hypercholesterolemia.
Colestimide has been reported to lower blood glucose levels in patients with type 2 diabetes complicated by hypercholesterolemia.. To examine the mechanism by which colestimide decreases plasma glucose levels in the above patients.. A total of 16 inpatients with type 2 diabetes complicated by hypercholesterolemia received colestimide for 1 week after their plasma glucose levels stabilized. We measured plasma glucose, serum immunoreactive insulin (IRI), serum lipid, plasma glucagon, and plasma glucagon-like peptide-1 (GLP-1) levels. These variables at baseline and 1 week of colestimide administration were compared.. Preprandial plasma glucose levels (baseline: 132 +/- 33 mg/dL vs. completion: 118 +/- 43 mg/dL, P=0.073) tended to decrease after colestimide administration, while 1-hr postprandial plasma glucose levels (baseline: 208 +/- 49 mg/dL vs. completion: 166 +/- 30 mg/dL, P<0.001) and 2-hr postprandial plasma glucose levels (baseline: 209 +/- 56 mg/dL vs. completion: 178 +/- 39 mg/dL, P=0.015) decreased significantly at 1 week of colestimide administration. The 2-hr postprandial plasma GLP-1 level was significantly (P=0.015) higher at 1 week of colestimide administration as compared with the baseline level, while there were no significant changes in preprandial and 1-hr postprandial plasma GLP-1 levels.. The GLP-1-increasing activity of colestimide may explain, at least in part, the mechanism of its blood glucose-lowering activity in patients with type 2 diabetes complicated by hypercholesterolemia. Topics: Anion Exchange Resins; Blood Glucose; Diabetes Mellitus, Type 2; Epichlorohydrin; Female; Glucagon-Like Peptide 1; Humans; Hypercholesterolemia; Imidazoles; Lipids; Male; Middle Aged; Resins, Synthetic | 2007 |
European Association for the Study of Diabetes--43rd Annual Meeting. Therapeutic approaches: Part 1. 18-21 September 2007, Amsterdam, the Netherlands.
Topics: Animals; Clinical Trials as Topic; Diabetes Mellitus, Type 2; Dipeptidyl Peptidase 4; Dipeptidyl-Peptidase IV Inhibitors; Drug Design; Drug Evaluation, Preclinical; Glucagon-Like Peptide 1; Humans; Hypoglycemic Agents | 2007 |
Commentary: will it take Harry Potter to solve diabetes? Divining the future of diabetes care.
Topics: Blood Glucose; Diabetes Complications; Diabetes Mellitus, Type 1; Diabetes Mellitus, Type 2; Forecasting; Glucagon-Like Peptide 1; Humans; Hypoglycemic Agents; Insulin-Secreting Cells | 2007 |
[Incretin strategy in the treatment of type 2 diabetes mellitus--DPPIV--editorial].
Topics: Diabetes Mellitus, Type 2; Glucagon-Like Peptide 1; Humans; Incretins; Insulin | 2007 |
[New data on hypoglycemia risk and beta cell function].
Topics: C-Peptide; Cross-Over Studies; Diabetes Mellitus, Type 2; Drug Therapy, Combination; Exenatide; Glucagon-Like Peptide 1; Glycated Hemoglobin; Humans; Hypoglycemia; Hypoglycemic Agents; Insulin; Insulin Glargine; Insulin-Secreting Cells; Insulin, Long-Acting; Metformin; Peptides; Randomized Controlled Trials as Topic; Risk Factors; Time Factors; Venoms; Weight Gain; Weight Loss | 2007 |
Exenatide: new drug. Type 2 diabetes for some overweight patients.
(1) When type 2 diabetes is inadequately controlled with oral antidiabetic therapy, one option is to add subcutaneous insulin injections (or to accept less stringent glycaemic control). However, since the effects of adding insulin have only been evaluated in the short-term, effects on long-term clinical outcomes remain unknown. (2) Exenatide, a drug belonging to a new pharmacological class (incretin analogues), is marketed as a subcutaneously administered adjunct to inadequately effective oral antidiabetic therapy in adults with type 2 diabetes. (3) Three placebo-controlled trials lasting 7 months showed that adding exenatide to metformin and/or a glucose-lowering sulphonylurea yielded an HbA1c level of 7% or less in about 40% of patients treated with exenatide 10 micrograms twice a day, versus about 10% of patients on placebo. The potential impact of exenatide on morbidity and mortality is not known. (4) In two trials versus insulin glargine and in one trial versus insulin aspart (+ isophane insulin), exenatide was as effective as the various insulins in controlling HbA1c levels. (5) During clinical trials, patients receiving exenatide lost an average of about 2 kg after 6 months, while insulin was associated with a weight gain of about 2 kg. (6) There was a similar incidence of hypoglycaemia with exenatide and insulin. In patients treated with exenatide, concomitant use of glucose-lowering sulphonylurea increases the risk of hypoglycaemia. (7) More than half of patients on exenatide experienced nausea, versus fewer than 10% of patients on insulin glargine. (8) The long-term consequences of the presence of antiexenatide antibodies on the effectiveness of treatment are not known. (9) Exenatide is administered in two subcutaneous injections a day, at fixed doses. Insulin is administered in one or several injections a day, at doses adjusted to self-monitored blood glucose levels. (10) Adding insulin rather than exenatide is a better option in general when oral antidiabetic therapy fails in patients with type 2 diabetes, as we have more experience with insulin and there is no evidence of important advantages with exenatide. The latter should be reserved for situations in which weight gain is a major problem. Topics: Clinical Trials as Topic; Diabetes Mellitus, Type 2; Drug Therapy, Combination; Glucagon-Like Peptide 1; Glycated Hemoglobin; Humans; Hypoglycemia; Hypoglycemic Agents; Incretins; Injections, Subcutaneous; Metformin; Overweight; Peptides; Sulfonylurea Compounds; Venoms; Weight Gain; Weight Loss | 2007 |
[Two breakthroughs in the treatment of type 2 diabetes. Both the receptor agonist and enzyme inhibitors now available in the clinic].
Topics: Adamantane; Animals; Diabetes Mellitus, Type 2; Dipeptidyl Peptidase 4; Dipeptidyl-Peptidase IV Inhibitors; Drug Therapy, Combination; Enzyme Inhibitors; Exenatide; Glucagon-Like Peptide 1; Glucagon-Like Peptide-1 Receptor; Humans; Hypoglycemic Agents; Nitriles; Peptides; Pyrrolidines; Receptors, Glucagon; Treatment Outcome; Venoms; Vildagliptin | 2007 |
Human duodenal enteroendocrine cells: source of both incretin peptides, GLP-1 and GIP.
Among the products of enteroendocrine cells are the incretins glucagon-like peptide-1 (GLP-1, secreted by L cells) and glucose-dependent insulinotropic peptide (GIP, secreted by K cells). These are key modulators of insulin secretion, glucose homeostasis, and gastric emptying. Because of the rapid early rise of GLP-1 in plasma after oral glucose, we wished to definitively establish the absence or presence of L cells, as well as the relative distribution of the incretin cell types in human duodenum. We confirmed the presence of proglucagon and pro-GIP genes, their products, and glucosensory molecules by tissue immunohistochemistry and RT-PCR of laser-captured, single duodenal cells. We also assayed plasma glucose, incretin, and insulin levels in subjects with normal glucose tolerance and type 2 diabetes for 120 min after they ingested 75 g of glucose. Subjects with normal glucose tolerance (n=14) had as many L cells (15+/-1), expressed per 1,000 gut epithelial cells, as K cells (13+/-1), with some containing both hormones (L/K cells, 5+/-1). In type 2 diabetes, the number of L and L/K cells was increased (26+/-2; P<0.001 and 9+/-1; P < 0.001, respectively). Both L and K cells contained glucokinase and glucose transporter-1, -2, and -3. Newly diagnosed type 2 diabetic subjects had increased plasma GLP-1 levels between 20 and 80 min, concurrently with rising plasma insulin levels. Significant coexpression of the main incretin peptides occurs in human duodenum. L and K cells are present in equal numbers. New onset type 2 diabetes is associated with a shift to the L phenotype. Topics: Adult; Aged; Aged, 80 and over; Area Under Curve; Biopsy; Diabetes Mellitus, Type 2; Duodenum; Enteroendocrine Cells; Enzyme-Linked Immunosorbent Assay; Female; Gastric Inhibitory Polypeptide; Glucagon; Glucagon-Like Peptide 1; Glucagon-Like Peptides; Glucose; Glucose Tolerance Test; Humans; Immunohistochemistry; Insulin; Insulin Resistance; Male; Middle Aged; Peptide Fragments; Reverse Transcriptase Polymerase Chain Reaction | 2006 |
Effects of an olive oil-enriched diet on glucagon-like peptide 1 release and intestinal content, plasma insulin concentration, glucose tolerance and pancreatic insulin content in an animal model of type 2 diabetes.
In the light of a recent study conducted in normal rats, the present investigations were aimed at exploring the immediate and long-term effects of an olive oil-enriched diet (OO diet) on GLP-1 release and intestinal content, plasma insulin concentration, glucose tolerance and pancreatic insulin content in adult rats that had been injected with streptozotocin during the neonatal period (STZ rats). The OO diet, when compared to a standard diet, increased the immediate GLP-1 response in meal-trained rats, but decreased GLP-1 content in the intestinal tract after 50 days. Over 50 days, the body weight gain was lower in the rats fed the OO diet compared to standard diet. In the former, however, no improvement of glucose tolerance or insulin response during an oral glucose tolerance test was observed. Thus, a paradoxical lowering of the insulinogenic index, i. e. the paired ratio between plasma insulin and glucose concentration, was recorded during the oral glucose tolerance test in rats fed either standard or OO diet. Moreover, the insulin content of the pancreas was equally low in the STZ rats fed either standard or OO diet. These findings will be discussed in the framework of possible differences in the pathophysiology of B-cell dysfunction in most patients with type-2 diabetes and the present animal model of non-insulin-dependent diabetes. Topics: Animals; Animals, Newborn; Blood Glucose; Diabetes Mellitus, Experimental; Diabetes Mellitus, Type 2; Diet; Disease Models, Animal; Female; Glucagon-Like Peptide 1; Glucose Tolerance Test; Insulin; Insulin-Secreting Cells; Intestinal Mucosa; Male; Olive Oil; Plant Oils; Rats; Rats, Wistar | 2006 |
Effects of fat on gastric emptying of and the glycemic, insulin, and incretin responses to a carbohydrate meal in type 2 diabetes.
Gastric emptying (GE) is a major determinant of postprandial glycemia. Because the presence of fat in the small intestine inhibits GE, ingestion of fat may attenuate the glycemic response to carbohydrate.. The objective of this study was to evaluate the effect of patterns of fat consumption on GE and glucose, insulin, glucagon-like peptide-1 (GLP-1), and glucose-dependent insulinotropic polypeptide (GIP) concentrations after a carbohydrate meal in type 2 diabetes.. This was a randomized, cross-over study in which GE of a radioisotopically labeled potato meal was measured on 3 d.. The study was performed at the Royal Adelaide Hospital.. Six males with type 2 diabetes were studied.. Subjects ingested 1) 30 ml water 30 min before the mashed potato (water), 2) 30 ml olive oil 30 min before the mashed potato (oil), or 3) 30 ml water 30 min before the mashed potato meal that contained 30 ml olive oil (water and oil).. GE, blood glucose, plasma insulin, GLP-1, and GIP concentrations were the main outcome measures.. GE was much slower with oil compared with both water (P < 0.0001) and water and oil (P < 0.05) and was slower after water and oil compared with water (P < 0.01). The postprandial rise in blood glucose was markedly delayed (P = 0.03), and peak glucose occurred later (P = 0.04) with oil compared with the two other meals. The rises in insulin and GIP were attenuated (P < 0.0001), whereas the GLP-1 response was greater (P = 0.0001), after oil.. Ingestion of fat before a carbohydrate meal markedly slows GE and attenuates the postprandial rises in glucose, insulin, and GIP, but stimulates GLP-1, in type 2 diabetes. Topics: Aged; Blood Glucose; Cross-Over Studies; Diabetes Mellitus, Type 2; Dietary Carbohydrates; Dietary Fats; Gastric Emptying; Gastric Inhibitory Polypeptide; Glucagon-Like Peptide 1; Humans; Insulin; Male; Middle Aged | 2006 |
Effect of glucagon-like peptide-1 on the beta cell response to glucose-dependent insulinotropic polypeptide in elderly patients with diabetes mellitus.
Topics: Aged; Blood Glucose; Diabetes Mellitus, Type 2; Follow-Up Studies; Gastric Inhibitory Polypeptide; Gastrointestinal Agents; Glucagon-Like Peptide 1; Humans; Infusions, Intravenous; Insulin; Insulin-Secreting Cells; Treatment Outcome | 2006 |
Byetta (exenatide): what's your gut feeling?
Topics: Clinical Trials, Phase III as Topic; Diabetes Mellitus, Type 2; Exenatide; Glucagon-Like Peptide 1; Humans; Peptides; Venoms | 2006 |
Pulsatile insulin secretion in elderly patients with diabetes.
Insulin pulsation is impaired in type 2 diabetes. GLP-1 increases pulsatile insulin secretion in these patients. We conducted these studies with the hypothesis that GLP-1 would enhance pulsatile insulin secretion and alter glucose metabolism in elderly patients with type 2 diabetes. Experiments were conducted in nine patients (age: 72+/-5 years; BMI: 27+/-3kg/m(2); diabetes duration: 7+/-3 years; HbA(1c): 6.6+/-0.9%). Subjects underwent three glucose clamp studies. The first was a euglycemic clamp to determine individual insulin clearance. In the second, GLP-1 was infused from 0-240min (0.75pM/kg/min) and glucose was maintained at fasting levels. The third was similar except that octreotide (30ng/kg/min) was infused with GLP-1 to suppress pulsatile insulin. Insulin and glucose were given to match levels during the second study. 3-(3)H-glucose was infused to allow calculation of hepatic glucose production and glucose disposal rates. There was no significant difference in measurements of pulsatile insulin secretion or hepatic glucose production and glucose disposal rates between the studies. Because there was no difference in pulsatile insulin between experiments, we could not test the effect of pulsatile insulin on glucose metabolism. Further studies are required to determine the impact of insulin pulses on glucose metabolism. Topics: Aged; Blood Glucose; Diabetes Mellitus, Type 2; Fasting; Glucagon-Like Peptide 1; Glucose Clamp Technique; Humans; Insulin; Insulin Secretion | 2006 |
Newer therapeutic options for children with diabetes mellitus: theoretical and practical considerations.
Recent studies in adult patients with type 1 diabetes mellitus (T1DM) and T2DM have examined the potential utility, benefits, and side effects of agents that augment insulin secretion after oral ingestion of nutrients in comparison with intravenous nutrient delivery, the so-called incretins. Two families of incretin-like substances are now approved for use in adults. Glucagon-like peptide-1 (GLP-1) or agents that bind to its receptor (exenatide, Byetta) or agents that inhibit its destruction [dipeptidyl peptidase-IV (DPP-IV) inhibitors, Vildagliptin] improve insulin secretion, delay gastric emptying, and suppress glucagon secretion while decreasing food intake without increasing hypoglycemia. Pramlintide, a synthetic amylin analog, also decreases glucagon secretion and delays gastric emptying, improves hemoglobin A1c (HbA1C), and facilitates weight reduction without causing hypoglycemia. We review the historical discovery of these agents, their physiology [corrected] and their current applications. Remarkably, only one or two studies have been reported in children. Pediatricians caring for children with T1DM and T2DM should become familiar with these agents and investigate their applicability, as they seem likely to enhance our therapeutic armamentarium to treat children with diabetes mellitus. Topics: Amyloid; Child; Diabetes Mellitus, Type 1; Diabetes Mellitus, Type 2; Diet, Diabetic; Energy Intake; Glucagon-Like Peptide 1; Humans; Islet Amyloid Polypeptide | 2006 |
Novel glucagon-like peptide-1 (GLP-1) analog (Val8)GLP-1 results in significant improvements of glucose tolerance and pancreatic beta-cell function after 3-week daily administration in obese diabetic (ob/ob) mice.
This study evaluates the antidiabetic potential of an enzyme-resistant analog, (Val8)GLP-1. The effects of daily administration of a novel dipeptidyl peptidase IV-resistant glucagon-like peptide-1 (GLP-1) analog, (Val8)GLP-1, on glucose tolerance and pancreatic beta-cell function were examined in obese-diabetic (ob/ob) mice. Acute intraperitoneal administration of (Val8)GLP-1 (6.25-25 nmol/kg) with glucose increased the insulin response and reduced the glycemic excursion in a dose-dependent manner. The effects of (Val8)GLP-1 were greater and longer lasting than native GLP-1. Once-daily subcutaneous administration of (Val8)GLP-1 (25 nmol/kg) for 21 days reduced plasma glucose concentrations, increased plasma insulin, and reduced body weight more than native GLP-1 without a significant change in daily food intake. Furthermore, (Val8)GLP-1 improved glucose tolerance, reduced the glycemic excursion after feeding, increased the plasma insulin response to glucose and feeding, and improved insulin sensitivity. These effects were consistently greater with (Val8)GLP-1 than with native GLP-1, and both peptides retained or increased their acute efficacy compared with initial administration. (Val8)GLP-1 treatment increased average islet area 1.2-fold without changing the number of islets, resulting in an increased number of larger islets. These data demonstrate that (Val8)GLP-1 is more effective and longer acting than native GLP-1 in obese-diabetic ob/ob mice. Topics: Animals; Blood Glucose; Body Weight; Diabetes Mellitus, Type 2; Dose-Response Relationship, Drug; Eating; Glucagon-Like Peptide 1; Glucose Intolerance; Hypoglycemic Agents; Immunohistochemistry; Injections, Intraperitoneal; Insulin; Insulin-Secreting Cells; Islets of Langerhans; Male; Mice; Mice, Obese | 2006 |
Early and rapid development of insulin resistance, islet dysfunction and glucose intolerance after high-fat feeding in mice overexpressing phosphodiesterase 3B.
Inadequate islet adaptation to insulin resistance leads to glucose intolerance and type 2 diabetes. Here we investigate whether beta-cell cAMP is crucial for islet adaptation and prevention of glucose intolerance in mice. Mice with a beta-cell-specific, 2-fold overexpression of the cAMP-degrading enzyme phosphodiesterase 3B (RIP-PDE3B/2 mice) were metabolically challenged with a high-fat diet. We found that RIP-PDE3B/2 mice early and rapidly develop glucose intolerance and insulin resistance, as compared with wild-type littermates, after 2 months of high-fat feeding. This was evident from advanced fasting hyperinsulinemia and early development of hyper-glycemia, in spite of hyperinsulinemia, as well as impaired capacity of insulin to suppress plasma glucose in an insulin tolerance test. In vitro analyses of insulin-stimulated lipogenesis in adipocytes and glucose uptake in skeletal muscle did not reveal reduced insulin sensitivity in these tissues. Significant steatosis was noted in livers from high-fat-fed wild-type and RIP-PDE3B/2 mice and liver triacyl-glycerol content was 3-fold higher than in wild-type mice fed a control diet. Histochemical analysis revealed severe islet perturbations, such as centrally located alpha-cells and reduced immunostaining for insulin and GLUT2 in islets from RIP-PDE3B/2 mice. Additionally, in vitro experiments revealed that the insulin secretory response to glucagon-like peptide-1 stimulation was markedly reduced in islets from high-fat-fed RIP-PDE3B/2 mice. We conclude that accurate regulation of beta-cell cAMP is necessary for adequate islet adaptation to a perturbed metabolic environment and protective for the development of glucose intolerance and insulin resistance. Topics: 3',5'-Cyclic-AMP Phosphodiesterases; Adaptation, Physiological; Animals; Blood Glucose; Cyclic AMP; Cyclic Nucleotide Phosphodiesterases, Type 3; Diabetes Mellitus, Type 2; Dietary Fats; Gene Expression; Glucagon-Like Peptide 1; Glucose Transporter Type 2; Immunohistochemistry; Insulin; Insulin Resistance; Insulin-Secreting Cells; Liver; Mice; Mice, Inbred C57BL; Mice, Inbred CBA; Mice, Transgenic; Triglycerides | 2006 |
Enhancing the action of incretin hormones: a new whey forward?
Topics: Animals; Diabetes Mellitus, Type 2; Gastric Inhibitory Polypeptide; Gastrointestinal Hormones; Glucagon-Like Peptide 1; Hormones; Humans; Insulin; Insulin Secretion; Mice; Milk Proteins; Peptides; Rats; Whey Proteins | 2006 |
Evaluation of the antidiabetic activity of DPP IV resistant N-terminally modified versus mid-chain acylated analogues of glucose-dependent insulinotropic polypeptide.
Glucose dependent insulinotropic polypeptide (GIP) is a gastrointestinal hormone with therapeutic potential for type 2 diabetes due to its insulin-releasing and antihyperglycaemic actions. However, development of GIP-based therapies is limited by N-terminal degradation by DPP IV resulting in a very short circulating half-life. Numerous GIP analogues have now been generated exhibiting DPP IV resistance and extended bioactivity profiles. In this study, we report a direct comparison of the long-term antidiabetic actions of three such GIP molecules, N-AcGIP, GIP(Lys(37)PAL) and N-AcGIP(Lys(37)PAL) in obese diabetic (ob/ob) mice. An extended duration of action of each GIP analogue was demonstrated prior to examining the effects of once daily injections (25nmolkg(-1) body weight) over a 14-day period. Administration of either N-AcGIP, GIP(Lys(37)PAL) or N-AcGIP(Lys(37)PAL) significantly decreased non-fasting plasma glucose and improved glucose tolerance compared to saline treated controls. All three analogues significantly enhanced glucose and nutrient-induced insulin release, and improved insulin sensitivity. The metabolic and insulin secretory responses to native GIP were also enhanced in 14-day analogue treated mice, revealing no evidence of GIP-receptor desensitization. These effects were accompanied by significantly enhanced pancreatic insulin following N-AcGIP(Lys(37)PAL) and increased islet number and islet size in all three groups. Body weight, food intake and circulating glucagon were unchanged. These data demonstrate the therapeutic potential of once daily injection of enzyme resistant GIP analogues and indicate that N-AcGIP is equally as effective as related palmitate derivatised analogues of GIP. Topics: Animals; Diabetes Mellitus, Type 2; Disease Models, Animal; Gastric Inhibitory Polypeptide; Glucagon-Like Peptide 1; Glucose; Homeostasis; Hypoglycemic Agents; Insulin; Mice; Mice, Obese; Pancreas | 2006 |
[Effects of GLP-1 treatment on protection of B cells in Otsuka Long-Evans Tokushima fatty rats].
To investigate the effect of GLP-1 on the blood glucose in type 2 diabetic rats, and its protective effects on the islet B cells.. Thirty rats were divided into three groups: spontaneous type 2 diabetes animal model OLETF rats, GLP-1 [from the twelfth week 56 micro/(kg.d), sc] therapy group and LETO rats as control. In the 14th and 20th weeks, standard OGTT including fast and 2 h-plasma glucose were measured respectively. In the 14th weeks, 3 rats from each group were killed randomly, and the rest of the rats were killed until the 20th week. Immunostaining with the marker of PCNA, TUNEL, and insulin assessed metabolic changes in the islet. Ultrastructure of the B cell was observed with the electronic microscope.. In the 14th and 20th week, AUC for insulin were higher in treated animals (10.86+/-1.56 vs. 9.07+/-1.28, P<0.01) and (13.00+/-1.50 vs. 10.35+/-0.86, P<0.01), which was paralleled by a decrease in AUC for glucose, (29.93+/-3.15 vs. 34.99+/-4.30, P<0.01) and (38.37+/-3.18 vs. 42.38+/-2.37, P<0.01). Ex vivo immunostaining with the marker of cell proliferation, PCNA, showed that the metabolic changes observed in rats treated with GLP-1 were associated with an increase in cell proliferation of the B cell (48.9+/-39.6 vs. 39.6+/-9.3, P<0.05). TUNEL staining, a marker of cellular apoptosis, indicated a reduction of apoptotic cells within the islet in GLP-1-treated rats (24.8+/-4.2 vs. 30.8+/-5.8, P<0.01). Immunostaining for the insulin showed a significant increase in insulin content in GLP-1-treated animals. GLP-1-treatment ameliorated the ultrastructure of the B cell.. Our findings have provided evidence that the beneficial effects of GLP-1 in OLETF rats are mediated by an increase in islet cell proliferation and a decrease of cellular apoptosis. Topics: Animals; Apoptosis; Cell Proliferation; Diabetes Mellitus, Type 2; Glucagon-Like Peptide 1; Immunohistochemistry; Insulin-Secreting Cells; Male; Proliferating Cell Nuclear Antigen; Protective Agents; Random Allocation; Rats; Rats, Inbred OLETF | 2006 |
Plasma dipeptidyl peptidase-IV activity in patients with type-2 diabetes mellitus correlates positively with HbAlc levels, but is not acutely affected by food intake.
Glucagon-like peptide-1 (GLP-1) and glucose-dependent insulinotropic polypeptide are incretin hormones, secreted in response to meal ingestion. The incretin hormones stimulate insulin secretion and are essential for the maintenance of normal plasma glucose concentrations. Both incretin hormones are metabolized quickly by the enzyme dipeptidyl peptidase-IV (DPP-IV). It is well known that type-2 diabetic patients have an impaired incretin effect. Therefore, the aim of the present study was to investigate plasma DPP-IV activity in the fasting and the postprandial state in type-2 diabetic patients and control subjects.. The study included two protocols. Protocol one involved 40 fasting type-2 diabetic patients (28 men); age 61 +/- 1.4 (mean +/- s.e.m.) years; body mass index (BMI) 31 +/- 0.6 kg/m(2); HbAlc 7.2 +/- 0.2%; and 20 matched control subjects (14 men) were studied. Protocol two involved eight type-2 diabetic patients (six men); age 63 +/- 1.2 years; BMI 33 +/- 0.5 kg/m(2); HbAlc 7.5 +/- 0.4%; eight matched control subjects were included.. In protocol one, fasting values of DPP-IV activity were evaluated and in protocol two, postprandial DPP-IV activity during a standard meal test (566 kcal) was estimated.. Mean fasting plasma DPP-IV activity (expressed as degradation of GLP-1) was significantly higher in this patient group compared with the control subjects (67.5 +/- 1.9 vs 56.8 +/- 2.2 fmol GLP-1/h (mean +/- s.e.m.); P=0.001). In the type-2 diabetic patients, DPP-IV activity was positively correlated to FPG and HbAlc and negatively to the duration of diabetes and age of the patients. No postprandial changes were seen in plasma DPP-IV activity in any of the groups.. Plasma DPP-IVactivity increases in the fasting state and is positively correlated to FPG and HbAlc levels, but plasma DPP-IV activity is not altered following meal ingestion and acute changes in plasma glucose. Topics: Blood Glucose; Body Mass Index; C-Peptide; Diabetes Mellitus, Type 2; Dipeptidyl Peptidase 4; Eating; Fasting; Female; Gastric Inhibitory Polypeptide; Glucagon-Like Peptide 1; Glycated Hemoglobin; Humans; Hypoglycemic Agents; Insulin; Male; Metformin; Middle Aged | 2006 |
[DPP-4 inhibition raises incretin levels].
Topics: Diabetes Mellitus, Type 2; Dipeptidyl Peptidase 4; Glucagon-Like Peptide 1; Humans; Peroxisome Proliferator-Activated Receptors; Protease Inhibitors; Pyrazines; Sitagliptin Phosphate; Triazoles | 2006 |
Inhibition of dipeptidyl peptidase-IV activity by metformin enhances the antidiabetic effects of glucagon-like peptide-1.
GLP-1 and GIP are insulin-releasing 'incretin' hormones inactivated following degradation by dipeptidyl peptidase IV. Incretin hormone analogues resistant to degradation by DPP IV, as well as, inhibitors of DPP IV are in development as novel treatments for type 2 diabetes. The biguanide metformin is an oral agent commonly prescribed to treat type 2 diabetes. Antidiabetic actions of metformin involve the reduction of hepatic glucose production and/or insulin resistance. Recent reports indicate that metformin may have the additional property of inhibiting DPP IV activity. Here we examine the effects of metformin on plasma DPP IV activity of normal and ob/ob diabetic mice. DPP IV activity present in mouse plasma was concentration-dependently inhibited by metformin generating IC(50) values of 38 microM for normal mice and 29 microM for ob/ob mice. In vivo metformin lowered plasma DPP IV activity in ob/ob mice, and improved glucose-lowering and insulin-releasing effects of exogenous GLP-1 administration. This was associated with increased circulating concentrations of active GLP-1(7-36)amide. In contrast metformin had minor effects on in vitro GLP-1-stimulated insulin release from clonal beta cells. Long-term (12 day) oral metformin administration to ob/ob mice resulted in lower DPP IV activity but had no effect on basal glucose and insulin levels. These findings indicate that metformin decreases the plasma DPP IV activity, limiting the inactivation of exogenously administered GLP-1 and improving glycaemic control. Topics: Analysis of Variance; Animals; Blood Glucose; Cell Line; Diabetes Mellitus, Type 2; Dipeptidyl Peptidase 4; Dipeptidyl-Peptidase IV Inhibitors; Fasting; Glucagon-Like Peptide 1; Glucose; Hypoglycemic Agents; Insulin; Insulin Secretion; Metformin; Mice; Mice, Obese; Time Factors | 2006 |
7-But-2-ynyl-9-(6-methoxy-pyridin-3-yl)-6-piperazin-1-yl-7,9-dihydro-purin-8-one is a novel competitive and selective inhibitor of dipeptidyl peptidase IV with an antihyperglycemic activity.
7-But-2-ynyl-9-(6-methoxy-pyridin-3-yl)-6-piperazin-1-yl-7,9-dihydro-purin-8-one (ER-319711) is a novel dipeptidyl peptidase (DPP)-IV inhibitor discovered in our laboratories. In this study, we have characterized this DPP-IV inhibitor in vitro and in vivo as an antidiabetic agent. The trifluoroacetate salt form of ER-319711, ER-319711-15, inhibited human DPP-IV with an IC(50) value of 0.089 microM, whereas its IC(50) values toward human DPP8 and DPP9 were >100 microM. Inhibition kinetic pattern analysis indicated that ER-319711-15 inhibited DPP-IV in a competitive manner. ER-319711-15 (1 mg/kg) reduced glucose excursion in an oral glucose tolerance test (OGTT) using Zucker fa/fa rats, with significant increases in plasma insulin and active glucagon-like peptide-1 levels. In an OGTT using mice fed a high-fat diet in which ER-319711-15 (0.1-10 mg/kg) was orally administered at 0 h, and glucose was loaded at 0 and 5 h, this compound improved glucose tolerance dose dependently at both 0- and 5-h glucose loading. Next, we compared efficacy of ER-319711-15, E3024, a competitive DPP-IV inhibitor having an imidazopyridazinone structure, or vildagliptin, a slow-binding and long-acting DPP-IV inhibitor, at the same dose, 10 mg/kg, in the same procedures. At the first glucose challenge, all compounds lowered area under the curve (AUC) values of delta blood glucose between 0 and 2 h significantly to the same degree. At the second glucose load, the AUC values between 5 and 7 h were significantly decreased by ER-319711-15 and vildagliptin, but not by E3024. Therefore, ER-319711 might be a potent, competitive, and selective DPP-IV inhibitor with an antihyperglycemic activity. Topics: Adamantane; Animals; Blood Glucose; Diabetes Mellitus, Type 2; Dietary Fats; Dipeptidyl Peptidase 4; Dipeptidyl-Peptidases and Tripeptidyl-Peptidases; Dose-Response Relationship, Drug; Glucagon-Like Peptide 1; Glucose Intolerance; Glucose Tolerance Test; Hypoglycemic Agents; Imidazoles; Insulin; Kinetics; Mice; Mice, Inbred C57BL; Nitriles; Piperazines; Protease Inhibitors; Purines; Pyridazines; Pyrrolidines; Rats; Rats, Zucker; Tosyl Compounds; Vildagliptin | 2006 |
[Therapy concept with future].
Topics: Animals; Diabetes Mellitus, Type 2; Exenatide; Glucagon-Like Peptide 1; Humans; Insulin; Insulin Secretion; Lizards; Peptides; Time Factors; Venoms | 2006 |
[Improved blood sugar control plus weight loss].
Topics: Blood Glucose; Clinical Trials as Topic; Diabetes Mellitus, Type 2; Drug Therapy, Combination; Exenatide; Glucagon-Like Peptide 1; Glycated Hemoglobin; Humans; Hypoglycemic Agents; Metformin; Peptides; Sulfonylurea Compounds; Time Factors; Venoms; Weight Loss | 2006 |
What are incretins, and how will they influence the management of type 2 diabetes?
To review the pathophysiology of type 2 diabetes (T2DM), the role of incretins, the potential of incretin-based therapies to address unmet therapeutic needs in T2DM, and the potential impact this will have on the contribution of managed care pharmacy to diabetes therapy.. Diabetes, the fifth leading cause of death by disease in the United States, costs approximately $132 billion per year in direct and indirect medical expenses. According to the Centers for Disease Control and Prevention.s National Health and Nutrition Examination Survey, a majority of diabetes patients do not achieve target A1C levels with their current treatment regimens. Advances in understanding the pathophysiologic abnormalities underlying the metabolic dysfunctions associated with T2DM are leading to the development of new treatment approaches and new therapeutic classes of drugs. Novel incretin-based therapies currently available, and in late-stage development, are among those showing the greatest promise for addressing the unmet needs of traditional therapies. Topics: Adenosine Deaminase; Adenosine Deaminase Inhibitors; Diabetes Mellitus, Type 2; Dipeptidyl Peptidase 4; Dipeptidyl-Peptidase IV Inhibitors; Disease Management; Drug Design; Drugs, Investigational; Glucagon-Like Peptide 1; Glycated Hemoglobin; Glycoproteins; Humans; Hypoglycemic Agents; Insulin Resistance; Managed Care Programs; Obesity; Prevalence | 2006 |
[Blood sugar and pounds down, hardly hypoglycemias. New generation of antidiabetics ante portas].
Topics: Animals; Clinical Trials as Topic; Diabetes Mellitus, Type 2; Exenatide; Glucagon-Like Peptide 1; Glycated Hemoglobin; Humans; Hypoglycemic Agents; Lizards; Peptides; Placebos; Time Factors; Venoms; Weight Loss | 2006 |
[Type 2 diabetes: hypoglycemia risk, weight gain... Will there soon be a new alternative to insulin?].
Topics: Diabetes Mellitus, Type 2; Glucagon-Like Peptide 1; Glycated Hemoglobin; Humans; Hypoglycemia; Hypoglycemic Agents; Insulin; Insulin-Secreting Cells; Stimulation, Chemical; Weight Gain | 2006 |
Roux-en-Y gastric bypass, Nesidioblastosis and diabetes mellitus.
Topics: Animals; Cell Proliferation; Comorbidity; Diabetes Mellitus, Type 2; Gastric Bypass; Glucagon-Like Peptide 1; Humans; Hyperinsulinism; Hyperplasia; Hypertrophy; Hypoglycemia; Incidence; Insulin; Insulin Secretion; Insulin-Secreting Cells; Nesidioblastosis; Obesity, Morbid; Postoperative Complications; Rats | 2006 |
GLP-1 and changes in glucose tolerance following gastric bypass surgery in morbidly obese subjects.
It has been proposed, that the dramatic amelioration of type 2 diabetes following Roux-en-Y gastric bypass (RYGBP) could by accounted for, at least in part, by changes in glucagon-like peptide-1 (GLP-1) secretion. However, human data supporting this hypothesis is scarce.. A 12-month prospective study on the changes in glucose homeostasis, and active GLP-1 in response to a standard test meal (STM) was conducted in 34 obese subjects (BMI 49.1+/-1.0 kg/m(2)) who had different degrees of glucose tolerance: normal glucose tolerance (NGT, n=12), impaired glucose tolerance (IGT, n=12), and type 2 diabetes (n=10).. At 6 weeks after RYGBP, despite the subjects still being markedly obese (BMI 43.5+/-0.9 kg/m(2)), fasting plasma glucose and HbA1c decreased in the 3 study groups (P<0.05). Insulin sensitivity improved, but was still abnormal in a comparable proportion of subjects among groups (P=0.717). When insulin secretion was accounted for the prevailing insulin sensitivity, an increase was found in subjects with diabetes (P<0.05) although it remained lower compared to NGT- and IGT-subjects (P<0.01). At 12 months follow-up, no differences among groups were found in the evaluated glucose homeostasis parameters. Compared to baseline, at 6 weeks the incremental AUC(0-120') of active GLP-1 in response to the STM increased in NGT and IGT (P<0.05) but not in subjects with diabetes (P=0.285). However, the GLP-1 response to a STM was comparable among groups at 12 months follow-up (P=0.887).. 1) RYGBP was associated with an improvement but not complete restoration of glucose homeostasis at 6 weeks after surgery. 2) GLP-1 is not a critical factor for the early changes in glucose tolerance. Topics: Adult; Area Under Curve; Blood Glucose; Diabetes Mellitus, Type 2; Female; Follow-Up Studies; Gastric Bypass; Glucagon-Like Peptide 1; Glucose Tolerance Test; Glycated Hemoglobin; Humans; Insulin; Insulin Resistance; Male; Middle Aged; Obesity, Morbid; Prospective Studies; Time Factors; Treatment Outcome; Weight Loss | 2006 |
Characterization of beta-cell function impairment in first-degree relatives of type 2 diabetic subjects: modeling analysis of 24-h triple-meal tests.
To investigate early secretory defects in prediabetes, we evaluated beta-Cell function and insulin sensitivity (M value, by euglycemic clamp) in 26 normotolerant first-degree relatives of type 2 diabetic patients (FDR) and 17 age- and weight-matched control subjects. beta-Cell function was assessed by modeling analysis of glucose and C-peptide concentrations measured during 24 h of standardized living conditions. Fasting and total insulin secretion (ISR) were increased in FDR, as was ISR at a reference 5 mM glucose level (ISR5, 107 +/- 6 vs. 87 +/- 6 pmol x min(-1) x m(-2), P < 0.05). ISR5 was inversely related to M in controls (ISR5 = k/M1.23, rho = -0.74, P < 0.005) but not in FDR; when M was accounted for (by calculating a compensation index ISR5 x M1.23), compensation for insulin resistance was impaired in FDR (10.8 +/- 1.0 vs. 13.4 +/- 0.6 units, P < 0.05). Potentiation of ISR, expressing relative transient increases in glucose-stimulated ISR during meals, was impaired in FDR (1.29 +/- 0.08 vs. 1.62 +/- 0.08 during 1st meal, P < 0.02). Moreover, the potentiation time course was related to glucose-dependent insulin-releasing polypeptide (GIP) concentrations in both groups, and the sensitivity of potentiation to GIP derived from this relationship tended to be impaired in FDR. Compensation index, potentiation, and sensitivity to GIP were interrelated parameters (P < 0.05 or less). beta-Cell function parameters were also related to mean 24-h glucose levels (r2 = 0.63, P < 0.0001, multivariate model). In conclusion, although in absolute terms ISR is increased in insulin-resistant FDR, beta-cell function shows a cluster of interrelated abnormalities involving compensation for insulin resistance, potentiation, and sensitivity to GIP, suggesting a beta-cell defect in the amplifying pathway of insulin secretion. Topics: Adult; Blood Glucose; C-Peptide; Diabetes Mellitus, Type 2; Diet; Energy Intake; Family; Female; Gastric Inhibitory Polypeptide; Glucagon; Glucagon-Like Peptide 1; Glucose Clamp Technique; Glucose Intolerance; Humans; Insulin; Insulin Resistance; Insulin Secretion; Islets of Langerhans; Linear Models; Male; Models, Biological; Multivariate Analysis; Peptide Fragments; Protein Precursors | 2005 |
(2R)-4-oxo-4-[3-(trifluoromethyl)-5,6-dihydro[1,2,4]triazolo[4,3-a]pyrazin-7(8H)-yl]-1-(2,4,5-trifluorophenyl)butan-2-amine: a potent, orally active dipeptidyl peptidase IV inhibitor for the treatment of type 2 diabetes.
A novel series of beta-amino amides incorporating fused heterocycles, i.e., triazolopiperazines, were synthesized and evaluated as inhibitors of dipeptidyl peptidase IV (DPP-IV) for the treatment of type 2 diabetes. (2R)-4-Oxo-4-[3-(trifluoromethyl)-5,6-dihydro[1,2,4]triazolo[4,3-a]pyrazin-7(8H)-yl]-1-(2,4,5-trifluorophenyl)butan-2-amine (1) is a potent, orally active DPP-IV inhibitor (IC(50) = 18 nM) with excellent selectivity over other proline-selective peptidases, oral bioavailability in preclinical species, and in vivo efficacy in animal models. MK-0431, the phosphate salt of compound 1, was selected for development as a potential new treatment for type 2 diabetes. Topics: Administration, Oral; Animals; Binding Sites; Biochemistry; Blood Glucose; Crystallography, X-Ray; Diabetes Mellitus, Type 2; Dipeptidyl Peptidase 4; Dogs; Dose-Response Relationship, Drug; Drug Evaluation, Preclinical; Enzyme Inhibitors; Glucagon; Glucagon-Like Peptide 1; Glucose Tolerance Test; Hypoglycemic Agents; Mice; Mice, Inbred C57BL; Models, Molecular; Peptide Fragments; Protein Conformation; Protein Precursors; Pyrazines; Rats; Sitagliptin Phosphate; Structure-Activity Relationship; Triazoles | 2005 |
Impaired circulating glucagon-like peptide-1 response to oral glucose in women with previous gestational diabetes.
Women with previous gestational diabetes (pGDM) are at risk of developing Type 2 diabetes. Glucagon-like peptide-1 (GLP-1) potentiates the insulin response to oral glucose, and its secretion is diminished in Type 2 diabetes. The aim of the study was to see if decreased GLP-1 secretion might be an early abnormality in the progression to Type 2 diabetes and would therefore be diminished in women with pGDM.. Eleven women with pGDM and previously documented normal glucose tolerance and 11 control women underwent a 75 g oral glucose tolerance test (OGTT). Circulating plasma glucose, insulin, nonesterified fatty acids (NEFA) and GLP-1 concentrations were sampled.. One of the women with pGDM had impaired glucose tolerance and was excluded from the study. All other women had normal glucose tolerance. The women with pGDM had higher fasting glucose concentrations than controls (5.1; 4.9-5.3 vs. 4.8; 4.4-5.1 mmol/l, median; interquartile range, P = 0.04) and greater circulating glucose area under the curve (AUC) following the oral glucose load (930; 818-1015 vs. 668; 584-737 min x mmol/l, P = 0.0007). Fasting insulin concentrations and total insulin AUC were similar. The initial (0-30 min) insulin response was decreased in the pGDM women (AUC 3981; 2783-4795 vs. 6167; 5009-8145 min x pmol/l, P = 0.05). The initial (0-30 min) GLP-1 response was reduced in the pGDM women (AUC 816; 663-984 vs. 1163; 872-2024 min x pmol/l, P = 0.02).. A reduced initial GLP-1 response to oral glucose may therefore be an early abnormality in the progression to Type 2 diabetes. Topics: Adult; Area Under Curve; Case-Control Studies; Diabetes Mellitus, Type 2; Diabetes, Gestational; Female; Glucagon; Glucagon-Like Peptide 1; Glucose; Glucose Tolerance Test; Humans; Insulin; Peptide Fragments; Pregnancy; Protein Precursors; Secretory Rate | 2005 |
A chlorogenic acid-induced increase in GLP-1 production may mediate the impact of heavy coffee consumption on diabetes risk.
Recent prospective epidemiology links heavy coffee consumption to a substantial reduction in risk for type 2 diabetes. Yet there is no evidence that coffee improves insulin sensitivity and, at least in acute studies, caffeine has a negative impact in this regard. Thus, it is reasonable to suspect that coffee influences the risk for beta cell "failure" that precipitates diabetes in subjects who are already insulin resistant. Indeed, there is recent evidence that coffee increases production of the incretin hormone glucagon-like peptide-1 (GLP-1), possibly owing to an inhibitory effect of chlorogenic acid (CGA -- the chief polyphenol in coffee) on glucose absorption. GLP-1 acts on beta cells, via cAMP-dependent mechanisms, to promote the synthesis and activity of the transcription factor IDX-1, crucial for maintaining the responsiveness of beta cells to an increase in plasma glucose. Conversely, the "glucolipotoxicity" thought to initiate and sustain beta cell dysfunction in diabetics can suppress expression of this transcription factor. The increased production of GLP-1 associated with frequent coffee consumption could thus be expected to counteract the adverse impact of chronic free fatty acid overexposure on beta cell function in overweight insulin resistant subjects. CGA's putative impact on glucose absorption may reflect the ability of this compound to inhibit glucose-6-phosphate translocase 1, now known to play a role in intestinal glucose transport. Delayed glucose absorption may itself protect beta cells by limiting postprandial hyperglycemia -- though, owing to countervailing effects of caffeine on plasma glucose, and a paucity of relevant research studies, it is still unclear whether coffee ingestion blunts the postprandial rise in plasma glucose. More generally, diets high in "lente carbohydrate", or administration of nutraceuticals/pharmaceuticals which slow the absorption of dietary carbohydrate, should help preserve efficient beta cell function by boosting GLP-1 production, as well as by blunting the glucotoxic impact of postprandial hyperglycemia on beta cell function. Topics: Chlorogenic Acid; Coffee; Diabetes Mellitus, Type 2; Glucagon; Glucagon-Like Peptide 1; Glucose; Humans; Peptide Fragments; Protein Precursors | 2005 |
Glucagon-like peptide-1 mediates the therapeutic actions of DPP-IV inhibitors.
Topics: Adenosine Deaminase; Adenosine Deaminase Inhibitors; Blood Glucose; Diabetes Mellitus, Type 2; Dipeptidyl Peptidase 4; Enzyme Inhibitors; Gastric Emptying; Glucagon; Glucagon-Like Peptide 1; Glycoproteins; Homeostasis; Humans; Models, Biological; Nausea; Peptide Fragments; Protein Precursors; Vomiting | 2005 |
The therapeutic actions of DPP-IV inhibition are not mediated by glucagon-like peptide-1.
Topics: Adenosine Deaminase; Adenosine Deaminase Inhibitors; Blood Glucose; Diabetes Mellitus, Type 2; Dipeptidyl Peptidase 4; Enzyme Inhibitors; Gastric Emptying; Glucagon; Glucagon-Like Peptide 1; Glycoproteins; Homeostasis; Humans; Nausea; Peptide Fragments; Protein Precursors; Vomiting | 2005 |
Dipeptidyl peptidase inhibitors as new drugs for the treatment of type 2 diabetes.
Inhibitors of the regulatory protease dipeptidyl peptidase-IV (DPP-IV) are currently under development in preclinical and clinical studies (several pharmaceutical companies, now in Phase III) as potential drugs for the treatment of type 2 diabetes. Their development is based on the observation that DPP-IV rapidly inactivates the incretin hormone glucagon-like peptide-1 (GLP-1), which is released postprandially from the gut and increases insulin secretion. DPP-IV inhibitors stabilise endogenous GLP-1 at physiological concentrations, and induce insulin secretion in a glucose-dependent manner; therefore, they do not demonstrate any hypoglycaemic effects. Furthermore, they are orally bioavailable. In addition to their ability to protect GLP-1 against degradation, DPP-IV inhibitors also stabilise other incretins, including gastric inhibitory peptide and pituitary adenylate cyclase-activating peptide. They also reduce the antagonistic and desensitising effects of the fragments formed by truncation of the incretins. In clinical studies, when used for the treatment of diabetes over a 1-year period, DPP-IV inhibitors show improved efficacy over time. This finding can be explained by a GLP-1-induced increase in the number of beta cells. Potential risks associated with DPP-IV inhibitors include the prolongation of the action of other peptide hormones, neuropeptides and chemokines cleaved by the protease, and their interaction with DPP-IV-related proteases. Based on their mode of action, DPP-IV inhibitors seem to be of particular value in early forms of type 2 diabetes, either alone or in combination with other types of oral agents. Topics: Adenosine Deaminase; Adenosine Deaminase Inhibitors; Diabetes Mellitus, Type 2; Dipeptidyl Peptidase 4; Enzyme Inhibitors; Gastric Inhibitory Polypeptide; Glucagon; Glucagon-Like Peptide 1; Glycoproteins; Humans; Insulin; Insulin Secretion; Models, Biological; Nerve Growth Factors; Neuropeptides; Neurotransmitter Agents; Peptide Fragments; Pituitary Adenylate Cyclase-Activating Polypeptide; Protein Precursors; Time Factors | 2005 |
What mediates the benefits associated with dipeptidyl peptidase-IV inhibition?
Topics: Adenosine Deaminase; Adenosine Deaminase Inhibitors; Animals; Diabetes Mellitus, Type 2; Dipeptidyl Peptidase 4; Enzyme Inhibitors; Gastric Inhibitory Polypeptide; Glucagon; Glucagon-Like Peptide 1; Glycated Hemoglobin; Glycoproteins; Glycosylation; Humans; Metformin; Mice; Nerve Growth Factors; Neuropeptides; Neurotransmitter Agents; Peptide Fragments; Pituitary Adenylate Cyclase-Activating Polypeptide; Protein Precursors | 2005 |
Proceedings from the GLP1 Meeting on the Occasion of the 80th Birthday of Prof. Dr. med. Dr. hc (em.) Werner Creutzfeldt.
Topics: Animals; Diabetes Mellitus, Type 2; Gastroenterology; Gastrointestinal Diseases; Glucagon; Glucagon-Like Peptide 1; Glucagon-Like Peptides; History, 20th Century; History, 21st Century; Humans; Liver Diseases; Pancreatic Diseases; Peptide Fragments; Peptides; Protein Precursors | 2005 |
Characterization of an N-acylated glucagon-like peptide-1 derivative by electron capture dissociation.
An N-acylated glucagon-like peptide 1 derivative was characterized by Fourier transform ion cyclotron resonance mass spectrometry. Both electron capture dissociation (ECD) and sustained off-resonance irradiation collisionally activated dissociation (SORI-CAD) were employed. While ECD revealed full sequence coverage, site of modification, branching point, structure of the palmitoylated modification, SORI-CAD produced less complete and more ambiguous information attributable to facile losses of the fatty acid group from both parent and fragments. Thus, ECD showed a superior characterization performance over SORI-CAD in analysis of N-acylated polypeptides. Topics: Acylation; Diabetes Mellitus, Type 2; Glucagon; Glucagon-Like Peptide 1; Hypoglycemic Agents; Peptide Fragments; Protein Precursors; Spectroscopy, Fourier Transform Infrared | 2005 |
[The role of incretins. Type 2 diabetes with new beginnings].
Topics: Diabetes Mellitus, Type 2; Disease Progression; Exenatide; Gastric Inhibitory Polypeptide; Glucagon; Glucagon-Like Peptide 1; Humans; Hypoglycemic Agents; Insulin; Insulin Resistance; Insulin Secretion; Peptide Fragments; Peptides; Protein Precursors; Venoms | 2005 |
Inhibition of dipeptidyl peptidase IV activity by oral metformin in Type 2 diabetes.
Glucagon-like peptide-1 (GLP-1) and gastric inhibitory polypeptide (GIP) are important insulinotropic hormones that enhance the insulin secretory response to feeding. Their potential for treating Type 2 diabetes is limited by short biological half-life owing to degradation by dipeptidyl peptidase IV (DPP IV). We investigated the acute effects of metformin on DPP IV activity in Type 2 diabetes to elucidate inhibition of DPP IV as a possible mechanism of action.. Eight fasting subjects with Type 2 diabetes (5M/3F, age 53.1+/-4.2 years, BMI 36.8+/-1.8 kg/m2, glucose 8.9+/-1.2 mmol/l, HbA1c 7.8+/-0.6%) received placebo or metformin 1 g orally 1 week apart in a random, crossover design.. Following metformin, DPP IV activity was suppressed compared with placebo (AUC0-6 h 3230+/-373 vs. 5764+/-504 nmol ml/l, respectively, P=0.001). Circulating glucose, insulin and total GLP-1 were unchanged. Metformin also concentration-dependently inhibited endogenous DPP IV activity in vitro in plasma from Type 2 diabetic subjects.. Oral metformin effectively inhibits DPP IV activity in Type 2 diabetic patients, suggesting that the drug may have potential for future combination therapy with incretin hormones. Topics: Administration, Oral; Blood Glucose; Cross-Over Studies; Diabetes Mellitus, Type 2; Dipeptidyl Peptidase 4; Female; Gastric Inhibitory Polypeptide; Glucagon; Glucagon-Like Peptide 1; Humans; Hypoglycemic Agents; Male; Metformin; Middle Aged; Peptide Fragments; Protein Precursors | 2005 |
Chronic treatment with exendin(9-39)amide indicates a minor role for endogenous glucagon-like peptide-1 in metabolic abnormalities of obesity-related diabetes in ob/ob mice.
Glucagon-like peptide-1 (GLP-1) is a potent insulinotropic hormone proposed to play a role in both the pathophysiology and treatment of type 2 diabetes. This study has employed the GLP-1 receptor antagonist, exendin-4(9-39)amide (Ex(9-39)) to evaluate the role of endogenous GLP-1 in genetic obesity-related diabetes and related metabolic abnormalities using ob/ob and normal mice. Acute in vivo antagonistic potency of Ex(9-39) was confirmed in ob/ob mice by blockade of the insulin-releasing and anti-hyperglycaemic actions of intraperitoneal GLP-1. In longer term studies, ob/ob mice were given once daily injections of Ex(9-39) or vehicle for 11 days. Feeding activity, body weight, and both basal and glucose-stimulated insulin secretion were not significantly affected by chronic Ex(9-39) treatment. However, significantly elevated basal glucose concentrations and impaired glucose tolerance were evident at 11 days. These disturbances in glucose homeostasis were independent of changes of insulin sensitivity and reversed by discontinuation of the Ex(9-39) for 9 days. Similar treatment of normal mice did not affect any of the parameters measured. These findings illustrate the physiological extrapancreatic glucose-lowering actions of GLP-1 in ob/ob mice and suggest that the endogenous hormone plays a minor role in the metabolic abnormalities associated with obesity-related diabetes. Topics: Animals; Blood Glucose; Diabetes Mellitus, Type 2; Female; Glucagon; Glucagon-Like Peptide 1; Glucagon-Like Peptide-1 Receptor; Glucose Tolerance Test; Insulin; Male; Mice; Mice, Obese; Obesity; Peptide Fragments; Protein Precursors; Receptors, Glucagon; Time Factors | 2005 |
Participation of protein kinases in the stimulant action of GLP-1 on 2-deoxy-D-glucose uptake by normal rat skeletal muscle.
Several protein kinases were recently proposed for involvement in GLP-1-stimulated D-glucose transport in skeletal muscle from both normal subjects and type 2 diabetic patients. This study was mainly aimed at investigating the effect of potential inhibitors of distinct protein kinases and protein phosphatase-1 upon insulin- and GLP-1-stimulated 2-deoxy-D-glucose net uptake by normal rat skeletal muscle. The basal uptake of the D-glucose analog was decreased by wortmannin--a phosphatidylinositol-3-kinase inhibitor--, PD98059--a mitogen-activated protein kinases inhibitor--, and TNFalpha--a protein phosphatase-1 inhibitor--, but not by either rapamycin--a p70s6 kinase inhibitor--, or H-7--, a protein kinase C inhibitor--. The enhancing action of both insulin and GLP-1 upon 2-deoxy-D-glucose transport was abolished by PD98059 and H-7, but largely unaffected by TNFalpha. Wortmannin and rapamycin preferentially affected the response to GLP-1 and insulin, respectively. These findings thus document both analogies and dissimilarities in the participation of the concerned enzymes in the stimulant action of insulin versus GLP-1 upon D-glucose transport in normal rat skeletal muscle. Topics: Animals; Biological Transport; Deoxyglucose; Diabetes Mellitus, Type 2; Enzyme Inhibitors; Glucagon; Glucagon-Like Peptide 1; Muscle, Skeletal; Organ Culture Techniques; Peptide Fragments; Protein Kinases; Protein Precursors; Rats; Rats, Wistar | 2005 |
Glucagon-like peptide-1 plasmid construction and delivery for the treatment of type 2 diabetes.
Glucagon-like peptide-1 (GLP-1) is a 30-amino-acid hormone produced by intestinal L cells. It has been proposed that GLP-1 can be used as a new treatment for type 2 diabetes mellitus because it acts to augment insulin secretion and its effectiveness is maintained in type 2 diabetic patients. Despite its many remarkable advantages as a therapeutic agent for diabetes, GLP-1 is not immediately clinically applicable because of its extremely short half-life. One way to overcome this drawback is GLP1 gene delivery, which enables GLP-1 production in the body. In this study, the effect of GLP1 gene delivery was evaluated both in vitro and in vivo using a new plasmid constructed with a GLP1 (7-37) cDNA. The expression of the GLP1 gene was driven by a SV40 promoter/enhancer. To increase the expression level of GLP-1, nuclear factor kappaB binding sites were introduced. The in vitro results showed expression of GLP-1 and in vitro activity of GLP-1, which is a glucose-dependent insulinotropic action. A single systemic administration of polyethyleneimine/pSIGLP1NFkappaB complex into DIO mice resulted in increasing insulin secretion and decreasing blood glucose levels for a duration longer than 2 weeks. Topics: Animals; Blood Glucose; Diabetes Mellitus, Experimental; Diabetes Mellitus, Type 2; Genetic Vectors; Glucagon; Glucagon-Like Peptide 1; Injections, Intravenous; Insulin; Insulin Secretion; Islets of Langerhans; Male; Mice; Mice, Inbred C57BL; Peptide Fragments; Plasmids; Protein Precursors | 2005 |
Deconvolution analysis of rapid insulin pulses before and after six weeks of continuous subcutaneous administration of glucagon-like peptide-1 in elderly patients with type 2 diabetes.
Insulin is secreted in a pulsatile fashion with measurable orderliness (low entropy). Normal aging and diabetes in middle-aged patients is characterized by alterations in pulsatile insulin release.. We undertook the current studies to determine whether disruptions in pulsatile insulin release also accompany diabetes in the elderly.. Two studies were performed. In the first study, insulin values were sampled every minute for 1 h under fasting conditions. In the second study, subjects underwent a 2-h hyperglycemic glucose clamp (glucose 5.4 mm above basal). From 60-120 min, insulin was sampled every 1 min. Secretory pulse analysis was conducted using a multiparameter deconvolution technique.. The study was conducted in a general clinical research center and during outpatient visits.. Volunteers were healthy young [n = 10; body mass index (BMI), 23 +/- 1 kg/m2; age, 23 +/- 1 yr] and elderly (n = 10; BMI, 24 +/- 1 kg/m2; age, 78 +/- 2 yr) volunteers and elderly patients with diabetes (n = 8; BMI, 28 +/- 1 kg/m2; age, 73 +/- 2 yr).. Five of the older patients with type 2 diabetes (BMI, 29 +/- 1 kg/m2; age, 72 +/- 2 yr) were treated with continuous sc glucagon-like peptide-1 (GLP-1) (7-36) amide infusion for 6 wk, and a second 2-h hyperglycemic clamp was performed.. Insulin burst mass, pulsatile insulin secretion, and entropy were measured.. Under fasting conditions, elderly patients with diabetes had a reduction in insulin burst mass (P < 0.05) that was similar to normal elderly. During hyperglycemia, elderly patients with diabetes had an even greater impairment in insulin burst mass (P < 0.05) and basal (P < 0.05) and pulsatile insulin secretion (P < 0.05) than normal elderly. Approximate entropy, a measure of irregularity of insulin release, was increased to a greater extent in older diabetes patients than normal elderly, signifying loss of orderliness of insulin secretion (P < 0.05). In response to treatment with GLP-1, insulin burst mass (P < 0.05) and pulsatile insulin secretion (P < 0.05) improved significantly in elderly patients with diabetes.. We conclude that alterations in pulsatile insulin release can be improved in elderly patients with diabetes by the administration of sc GLP-1. Topics: Adult; Aged; Blood Glucose; Diabetes Mellitus, Type 2; Entropy; Glucagon-Like Peptide 1; Humans; Insulin; Insulin Secretion | 2005 |
KR-62436, 6-{2-[2-(5-cyano-4,5-dihydropyrazol-1-yl)-2-oxoethylamino]ethylamino}nicotinonitrile, is a novel dipeptidyl peptidase-IV (DPP-IV) inhibitor with anti-hyperglycemic activity.
Dipeptidyl peptidase-IV (DPP-IV) is involved in the inactivation of glucagon-like peptide-1 (GLP-1), a potent insulinotropic peptide. Thus, DPP-IV inhibition can be an effective approach to treat type 2 diabetes mellitus by potentiating insulin secretion. This study describes the biological effects of a new DPP-IV inhibitor, KR-62436 (6-{2-[2-(5-cyano-4,5-dihydropyrazol-1-yl)-2-oxoethylamino]ethylamino}nicotinonitrile) in vitro and in vivo. KR-62436 inhibited rat plasma DPP-IV, porcine kidney DPP-IV as well as human DPP-IV (Caco-2) with IC50 values of 0.78, 0.49, 0.14 microM, respectively. In addition, the compound (10 microM) almost completely inhibited DPP-IV-mediated degradation of GLP-1 in vitro. KR-62436 inhibited the enzyme in a competitive manner, and exhibited selectivity against several proteases including proline-specific proteases. In vivo efficacy of the compound was examined by using normal C57BL/6J mice and ob/ob mice, a type 2 diabetes animal model. Administration of KR-62436 to C57BL/6J mice either orally or subcutaneously resulted in the suppression of plasma DPP-IV activity, increase in intact GLP-1 and insulin levels in plasma. Furthermore, the plasma glucose concentrations during oral glucose tolerance test (OGTT) were reduced upon oral administration of KR-62436. This study demonstrates that KR-62436 could be a good lead compound for further development as a new anti-diabetic agent. Topics: Animals; Blood Glucose; Caco-2 Cells; Diabetes Mellitus, Type 2; Dipeptidyl Peptidase 4; Dose-Response Relationship, Drug; Enzyme Inhibitors; Glucagon; Glucagon-Like Peptide 1; Glucose Tolerance Test; Humans; Hypoglycemic Agents; Insulin; Kinetics; Male; Mice; Mice, Inbred C57BL; Mice, Obese; Nicotinic Acids; Nitriles; Peptide Fragments; Peptide Hydrolases; Protein Precursors; Rats; Spectrometry, Mass, Matrix-Assisted Laser Desorption-Ionization; Swine | 2005 |
[Novel therapy in type 2 diabetes: to regulate glucose metabolism naturally].
Topics: Animals; Clinical Trials as Topic; Diabetes Mellitus, Type 2; Exenatide; Glucagon; Glucagon-Like Peptide 1; Glucose; Humans; Hypoglycemic Agents; Infant, Newborn; Insulin Resistance; Lizards; Peptide Fragments; Peptides; Protein Precursors; Time Factors; Venoms | 2005 |
Biotechnology - 12th European Congress.
Topics: Animals; Antibodies, Monoclonal; Biotechnology; Clinical Trials, Phase III as Topic; Desensitization, Immunologic; Diabetes Mellitus, Type 2; Factor VII; Factor VIIa; Glucagon-Like Peptide 1; Humans; Immunotherapy; Isoantibodies; Liraglutide; Mice; Pharmaceutical Preparations; Protein Conformation; Proteomics; Rats; Receptors, G-Protein-Coupled; Recombinant Proteins; RNA, Small Interfering; Stem Cells; Tissue Engineering | 2005 |
Early improvement of glucose tolerance after ileal transposition in a non-obese type 2 diabetes rat model.
Surgical operations which shorten the intestinal tract between the stomach and the terminal ileum result in an early improvement in type 2 diabetes, and one possible explanation is the arrival of undigested food in the terminal ileum. This study was designed to evaluate the role of the distal ileum in the improvement of glucose control in type 2 diabetic patients who underwent bariatric surgery.. An ileal transposition (IT) to the jejunum was performed in lean diabetic Goto-Kakizaki (GK) rats. The IT was compared to sham-operated diabetic rats and a control group of diabetic rats. Non-diabetic controls were age-matched Sprague-Dawley (SD) rats, which underwent IT and no operation. Food intake and body weight were measured. An oral glucose tolerance test (OGTT) was performed 10 days before the operation and 10 days, 30 days and 45 days after the surgery. GLP-1 and insulin were measured during the OGTT 45 days after surgery. An insulin tolerance test (ITT) was performed 50 days after surgery.. Glucose tolerance improved in the IT diabetic group compared with both the sham-operated animals and control diabetic group 30 days and 45 days after surgery (P=0.029 and P=0.023, respectively). Insulin sensitivity, as measured by an ITT, was not significantly different between diabetic groups and the normal groups respectively after surgery. No differences in basal glucose and glucose tolerance were noted between non-diabetic operated animals and control non-diabetic rats. No differences were recorded between the diabetic rat groups and the non-diabetic rats in terms of weight and food intake. GLP-1 levels were significantly higher in the IT diabetic group compared with the sham-operated rats (P=0.05).. Ileal transposition is effective in inducing an improvement in glucose tolerance in lean diabetic rats without affecting weight and food intake. The possible mechanism underlying the early improvement of diabetes after bariatric surgery may be due to the action of the terminal ileum through an insulin-independent action. Topics: Animals; Blood Glucose; Body Weight; Diabetes Mellitus, Experimental; Diabetes Mellitus, Type 2; Glucagon-Like Peptide 1; Glucose Intolerance; Glucose Tolerance Test; Ileum; Insulin; Insulin Resistance; Jejunum; Male; Rats; Rats, Sprague-Dawley; Weight Gain | 2005 |
Hyperinsulinemic hypoglycemia with nesidioblastosis after gastric-bypass surgery.
Topics: Animals; Diabetes Mellitus, Type 2; Exenatide; Gastric Bypass; Glucagon-Like Peptide 1; Humans; Hyperinsulinism; Hypoglycemia; Insulin-Secreting Cells; Nesidioblastosis; Peptides; Postoperative Complications; Venoms | 2005 |
[New approach in the therapy of type 2 diabetes mellitus. Exenatide lowers HbA1c and body weight].
Topics: Body Weight; Diabetes Mellitus, Type 2; Exenatide; Glucagon-Like Peptide 1; Glycated Hemoglobin; Humans; Insulin; Insulin Glargine; Insulin, Long-Acting; Peptides; Prospective Studies; Randomized Controlled Trials as Topic; Venoms | 2005 |
[GLP-1 derivatives, for the prevention and treatment of type 2 diabetes mellitus].
Topics: Animals; Diabetes Mellitus, Type 2; Dogs; Exenatide; Glucagon-Like Peptide 1; Humans; Insulin; Insulin Secretion; Metabolic Syndrome; Obesity; Peptides; Venoms | 2005 |
New ways in which GLP-1 can regulate glucose homeostasis.
Glucagon-like peptide-1 (GLP-1) has a diverse set of peripheral actions which all serve to promote enhanced glucose tolerance, and for this reason it has become the basis for new treatments for type 2 diabetes. In this issue of the JCI, Knauf et al. provide clear evidence that GLP-1 signaling in the CNS is also linked to the control of peripheral glucose homeostasis by inhibiting non-insulin-mediated glucose uptake by muscle and increasing insulin secretion from the pancreas. The authors' work points to an important need to integrate diverse GLP-1 signaling actions and peripheral GLP-1 function in order to better understand both normal and abnormal glucose homeostasis. Topics: Animals; Brain; Central Nervous System; Diabetes Mellitus, Type 2; Glucagon; Glucagon-Like Peptide 1; Glucose; Homeostasis; Humans; Insulin; Models, Biological; Peptide Fragments; Proglucagon | 2005 |
Exenatide for the treatment of type 2 diabetes mellitus.
Exenatide is a glucagon-like peptide-1 agonist. It is being investigated as an add-on therapy for patients with type 2 diabetes mellitus who are taking oral antidiabetic drugs. Evidence indicates that exenatide reduces glycosylated hemoglobin and plasma glucose levels when compared with placebo. Limitations of the therapy include the need for twice daily injections and potentially dose-limiting nausea and vomiting. Long-term studies are required to determine the effects of exenatide on disease-related morbidity and mortality. Topics: Blood Glucose; Canada; Diabetes Mellitus, Type 2; Glucagon-Like Peptide 1; Humans; Hypoglycemic Agents; Insulin; Randomized Controlled Trials as Topic | 2005 |
Pathophysiology of prediabetes.
Type 2 diabetic patients pass through a phase of impaired glucose tolerence and/or impaired fasting glucose known as 'prediabetic state'. Prediabetic state form a part of syndrome X, other components being obesity, hypertension, dyslipidaemia, hyperinsulinaemia and insulin resistance. The pathophysiology of prediabetes is similar to type 2 diabetes mellitus, two basic defects are insulin resistance and early beta cell failure. In prediabetes, the rapid oscillations of insulin secretion are lost and amplitude of large pulses are decreased. When insulin is delivered in a pulsatile fashion that mimics the normal rapid oscillation, its hypoglycaemic effects are greater. In prediabetes, the glycaemic excursions after each meal are high and early insulin responses to meals tend to be lower than normal but the second phase of insulin secretion is delayed and prolonged. Topics: Blood Glucose; Diabetes Mellitus, Type 2; Disease Progression; Glucagon-Like Peptide 1; Glucose Intolerance; Glucose Tolerance Test; Humans; Hyperglycemia; Insulin; Insulin Resistance; Metabolic Syndrome; Prediabetic State | 2005 |
Hormonal changes after Roux-en Y gastric bypass for morbid obesity and the control of type-II diabetes mellitus.
Morbid obesity (MO) is associated with diabetes mellitus-type II (DM-II). Roux-en Y gastric bypass (RNY) has been shown to normalize glucose intolerance in these patients through an incompletely understood mechanism. Gastrointestinal hormonal changes have been suggested as an explanation for resolution of DM II. Preoperatively, 20 MO patients with DM-II were evaluated for demographics and fasting levels of the following: glucose, insulin, C-peptide, glucagon, cortisol, gastric inhibitory polypeptide (GIP), and glucagon-like peptide-1 (GLP-1). Each patient underwent RNY with a 15-cc gastric pouch and 150-cm Roux limb. Postoperatively, each of the variables was measured at 2 weeks, 6 weeks, and 12 weeks and compared with the preoperative result using Student t test with significance, P = 0.05. Results are expressed as mean +/- SD. Twenty patients (5 male and 15 female), age 40.3 +/- 7.9 years, weight 146.3 +/- 34.0 kg, height 158.7 +/- 18.7 cm, and BMI 52.7 +/- 8.8, were enrolled in this IRB-approved protocol. Weight and BMI decreased progressively (117.5 +/- 26.9 kg and 47.0 +/- 7.4, P = 0.01, respectively) during the study but reached significance only at 12 weeks. Fasting plasma glucose decreased significantly within 2 weeks after RNY. Insulin and cortisol both approached, but never achieved, significant changes over 12 weeks. GLP-1 increased initially, but not significantly. GIP and C-peptide both decreased significantly. Glucagon remained essentially unchanged over 12 weeks. RNY rapidly normalizes fasting plasma glucose in morbidly obese patients with DM-II. GIP, a gactor in the enteroinsulin axis, decreases and may play a role in the correction of DM-II after gastric bypass. Topics: Adult; Anastomosis, Roux-en-Y; Blood Glucose; C-Peptide; Diabetes Mellitus, Type 2; Female; Gastric Bypass; Gastric Inhibitory Polypeptide; Gastrointestinal Hormones; Glucagon; Glucagon-Like Peptide 1; Humans; Hydrocortisone; Insulin; Male; Middle Aged; Obesity, Morbid; Peptide Fragments; Protein Precursors | 2004 |
A gut response. The next generation of type 2 drugs.
Topics: Diabetes Mellitus, Type 2; Exenatide; Ghrelin; Glucagon; Glucagon-Like Peptide 1; Glucagon-Like Peptides; Humans; Hypoglycemic Agents; Peptide Fragments; Peptide Hormones; Peptide YY; Peptides; Protein Precursors; United States; Venoms | 2004 |
Typical Danish Caucasian type 2 diabetic patients do not commonly carry genetic variants in GIP and GLP-1 encoding regions of the proGIP and proglucagon genes.
The enteroinsular-axis is abnormal in type 2 diabetics, which contributes to the diabetic phenotype. The effect of the incretin hormone gastric inhibitory polypeptide (GIP) and the secretion of the incretin hormone glucagon-like peptide-1 (GLP-1) are thus greatly diminished. The explanation for these changes could be changes in the structure of either of the hormones or their receptors. Thus, the aim of this study was to study the occurrence of genetic variants in the GIP and GLP-1 encoding regions of the proGIP and proglucagon genes in type 2 diabetic patients and matched control subjects.. Genomic DNA was extracted from buffy coats from 12 Caucasian type 2 diabetics and 12 healthy subjects, matched with respect to sex, age and BMI. The GIP and GLP-1 sequences were amplified using specific primers using the polymerase chain reaction (PCR). The amplified products were then sequenced. No germ-line mutations were identified in the GIP and the GLP-1 encoding regions of the proGIP and proglucagon genes in either the type 2 diabetic or the control subjects.. The perturbed incretin effect in type 2 diabetics is not commonly caused by genetic variants in either the GIP or the GLP-1 encoding genes in type 2 diabetics. Topics: Aged; Base Sequence; Denmark; Diabetes Mellitus, Type 2; DNA; Female; Gastric Inhibitory Polypeptide; Genetic Predisposition to Disease; Glucagon; Glucagon-Like Peptide 1; Glucagon-Like Peptide-1 Receptor; Humans; Male; Middle Aged; Molecular Sequence Data; Peptide Fragments; Phenotype; Polymerase Chain Reaction; Predictive Value of Tests; Protein Precursors; Receptors, Gastrointestinal Hormone; Receptors, Glucagon; Sequence Analysis, DNA; White People | 2004 |
GLP-1: target for a new class of antidiabetic agents?
Topics: Diabetes Mellitus, Type 2; Exenatide; Glucagon; Glucagon-Like Peptide 1; Humans; Hypoglycemic Agents; Liraglutide; Peptide Fragments; Peptides; Protein Precursors; Venoms | 2004 |
Control of blood glucose by novel GLP-1 delivery using biodegradable triblock copolymer of PLGA-PEG-PLGA in type 2 diabetic rats.
The incretin hormone glucagon-like peptide-1 (GLP-1) is a promising candidate for treatment of type 2 diabetes mellitus. However, plasma half-life of GLP-1 is extremely short, thus multiple injections or continuous infusion is required for therapeutic use of GLP-1. Therefore, we investigated a new delivery system as a feasible approach to achieve sustained GLP-1 release for a 2-week period.. A water-soluble, biodegradable triblock copolymer of poly [(DL-lactide-co-glycolide)-b-ethylene glycol-b-(DL-lactide-coglycolide)] (ReGel) was used in this study as an injectable formulation for controlled release of GLP-1. GLP-1 was formulated into ReGel as insoluble zinc complex to stabilize GLP-1 against aggregation and slow down release. The GLP-1 release profile was monitored in vitro and in vivo. Zucker Diabetic Fatty rats were administered subcutaneously with the GLP-1 formulation. The concentration of GLP-1, insulin, and glucose was monitored every day after the GLP-1 administration.. The GLP-1 release from ReGel formulation in vitro and in vivo showed no initial burst and constant release for 2 weeks. Animal study demonstrated that the plasma insulin level was increased, and the blood glucose level was controlled for 2 weeks by one injection of ReGel/ ZnGLP-1 formulation.. It is concluded that one injection of zinc-complexed GLP-1 loaded ReGel can be used for delivery of bioactive GLP-1 during a 2-week period. Because this new delivery system is biocompatible and requires twice-a-month injection, it can improve patient compliance and cost-effectiveness. Topics: Animals; Blood Glucose; Delayed-Action Preparations; Diabetes Mellitus, Type 2; Excipients; Glucagon; Glucagon-Like Peptide 1; Hydrogels; Hypoglycemic Agents; Insulin; Lactic Acid; Male; Peptide Fragments; Polyethylene Glycols; Polyglycolic Acid; Polylactic Acid-Polyglycolic Acid Copolymer; Polymers; Protein Precursors; Rats; Rats, Zucker; Solubility | 2004 |
Expression, purification, and C-terminal amidation of recombinant human glucagon-like peptide-1.
Human glucagon-like peptide-1 (hGLP-1) (7-36) amide, a gastrointestinal hormone with a pharmaceutical potential in treating type 2 diabetes mellitus, is composed of 30 amino acid residues as a mature protein. We report here the development of a method for high-level expression and purification of recombinant hGLP-1 (7-36) amide (rhGLP-1) through glutathione S-transferase (GST) fusion expression system. The cDNA of hGLP-1-Leu, the 31st-residue leucine-extended precursor peptide, was prepared by annealing and ligating of artificially synthetic oligonucleotide fragments, inserted into pBluescript SK (+/-) plasmid, and then cloned into pGEX-4T-3 GST fusion vector. The fusion protein GST-hGLP-1-Leu, expressed in Escherichia coli strain BL21 (DE3), was purified by affinity chromatography after high-level culture and sonication of bacteria. Following cleavage of GST-hGLP-1-Leu by cyanogen bromide, the recombinant hGLP-1-Leu was released from fusion protein, and purified using QAE Sepharose ion exchange and RP C(18) chromatography. After purification, the precursor hGLP-1-Leu was transacylated by carboxypeptidase Y, Arg-NH(2) as a nucleophile, to produce rhGLP-1. Electrospray ionization mass spectrometry showed the molecular weight was as expected. The biological activity of rhGLP-1 in a rat model demonstrated that plasma glucose concentrations were significantly lower and insulin concentrations higher after intraperitoneal injection of rhGLP-1 together with glucose compared with glucose alone (P < 0.001). Topics: Animals; Arginine; Cathepsin A; Chromatography, Affinity; Chromatography, Ion Exchange; Cyanogen Bromide; Diabetes Mellitus, Type 2; Escherichia coli; Female; Gene Expression; Glucagon; Glucagon-Like Peptide 1; Glucose; Glutathione Transferase; Humans; Insulin; Leucine; Peptide Fragments; Protein Precursors; Rats; Rats, Sprague-Dawley; Recombinant Fusion Proteins | 2004 |
Effect of duodenal-jejunal exclusion in a non-obese animal model of type 2 diabetes: a new perspective for an old disease.
Topics: Anastomosis, Surgical; Animals; Blood Glucose; Body Weight; Diabetes Mellitus, Type 2; Disease Models, Animal; Duodenum; Female; Follow-Up Studies; Gastric Bypass; Glucagon; Glucagon-Like Peptide 1; Jejunum; Male; Peptide Fragments; Protein Precursors; Rats; Rats, Inbred Strains | 2004 |
Novel "second-generation" approaches for the control of type 2 diabetes.
Topics: Diabetes Mellitus, Type 2; Dipeptidyl Peptidase 4; Glucagon; Glucagon-Like Peptide 1; Humans; Hypoglycemic Agents; Peptide Fragments; Protease Inhibitors; Protein Precursors; Protein Tyrosine Phosphatase, Non-Receptor Type 1; Protein Tyrosine Phosphatases; Receptors, Cytoplasmic and Nuclear; Transcription Factors | 2004 |
[New diabetes therapy in clinical trial: will need adapted insulin supply be available soon? (interview by Dr. Judith Neumaier)].
Topics: Animals; Clinical Trials, Phase I as Topic; Diabetes Mellitus, Type 2; Dipeptidyl Peptidase 4; Glucagon; Glucagon-Like Peptide 1; Humans; Hypoglycemic Agents; Insulin; Mice; Peptide Fragments; Protease Inhibitors; Protein Precursors | 2004 |
A gut feeling.
Topics: Diabetes Mellitus, Type 2; Exenatide; Glucagon; Glucagon-Like Peptide 1; Humans; Hypoglycemic Agents; Insulin; Insulin Secretion; Peptide Fragments; Peptides; Protein Precursors; Venoms | 2004 |
Secretion of incretin hormones (GIP and GLP-1) and incretin effect after oral glucose in first-degree relatives of patients with type 2 diabetes.
Since insulin secretion in response to exogenous gastric inhibitory polypeptide (GIP) is diminished not only in patients with type 2 diabetes, but also in their normal glucose-tolerant first-degree relatives, it was the aim to investigate the integrity of the entero-insular axis in such subjects.. Sixteen first-degree relatives of patients with type 2 diabetes (4 male, 12 female, age 50+/-12 years, BMI 26.1+/-3.8 kg/m(2)) and 10 matched healthy controls (negative family history, 6 male, 4 female, 45+/-13 years, 26.1+/-4.2 kg/m(2)) were examined with an oral glucose load (75 g) and an "isoglycaemic" intravenous glucose infusion. Blood was drawn over 240 min for plasma glucose (glucose oxidase), insulin, C-peptide, GIP and glucagon-like peptide 1 (GLP-1; specific immunoassays).. The pattern of glucose concentrations could precisely be copied by the intravenous glucose infusion (p=0.99). Insulin secretion was stimulated significantly more by oral as compared to intravenous glucose in both groups (p<0.0001). The percent contribution of the incretin effect was similar in both groups (C-peptide: 61.9+/-5.4 vs. 64.4+/-5.8%; p=0.77; insulin: 74.2+/-3.3 vs. 75.8+/-4.9; p=0.97; in first-degree relatives and controls, respectively). The individual responses of GIP and GLP-1 secretion were significantly correlated with each other (p=0.0003). The individual secretion of both GIP and GLP-1 was identified as a strong predictor of the integrated incremental insulin secretory responses as well as of the incretin effect.. Despite a lower insulin secretory response to exogenous GIP, incretin effects are similar in first-degree relatives of patients with type 2 diabetes and control subjects. This may be the result of a B cell secretory defect that affects stimulation by oral and intravenous glucose to a similar degree. Nevertheless, endogenous secretion of GIP and GLP-1 is a major determinant of insulin secretion after oral glucose. Topics: Adult; Blood Glucose; Diabetes Mellitus, Type 2; Family; Female; Gastric Inhibitory Polypeptide; Glucagon; Glucagon-Like Peptide 1; Glucose; Humans; Insulin; Male; Middle Aged; Peptide Fragments; Protein Precursors | 2004 |
Orlistat augments postprandial increases in glucagon-like peptide-1 in obese type 2 diabetic patients: response to Damci et al.
Topics: Anti-Obesity Agents; Diabetes Mellitus, Type 2; Glucagon; Glucagon-Like Peptide 1; Humans; Lactones; Obesity; Orlistat; Peptide Fragments; Postprandial Period; Protein Precursors | 2004 |
Glucagon-like peptide: the time is near.
Topics: Diabetes Mellitus, Type 2; Dipeptidyl Peptidase 4; Genetic Therapy; Glucagon; Glucagon-Like Peptide 1; Half-Life; Humans; Insulin; Insulin Secretion; Peptide Fragments; Protein Precursors | 2004 |
Effects of lipase inhibition on gastric emptying of, and on the glycaemic, insulin and cardiovascular responses to, a high-fat/carbohydrate meal in type 2 diabetes.
We examined the effects of lipase inhibition with orlistat on (i) gastric emptying of, and (ii) the glycaemic, glucagon-like peptide-1 (GLP-1) and cardiovascular responses to, a high-fat/carbohydrate meal in type 2 diabetic patients.. Eight type 2 diabetic patients, who were aged 62 years (median range: 49-68 years) and managed by diet alone, consumed a meal containing 65 g powdered potato, 20 g glucose reconstituted with 200 ml water (labelled with 20 MBq (99m)Tc-sulphur-colloid) and 45 g margarine. They did this on two separate occasions, with and without 120 mg orlistat, and while in the seated position with their back against a gamma camera. Venous blood samples for measurement of blood glucose, plasma insulin and GLP-1 were obtained immediately before the meal and at regular intervals afterwards. Blood pressure (systolic and diastolic) and heart rate were measured using an automated device.. Gastric emptying of the meal was faster after orlistat than without orlistat (50% emptying time [mean +/- SEM], 61+/-8 min vs 98+/-5 min; p=0.0001). In the first 60 min after the meal blood glucose (p=0.001) and plasma insulin (p=0.01) concentrations were higher in patients who had taken orlistat; between 60 and 180 min plasma GLP-1 (p=0.02) concentrations were lower after orlistat than without orlistat. Between 0 and 30 min systolic blood pressure (p=0.003) was lower, and heart rate (p=0.03) greater in subjects who had taken orlistat than in those who had not.. Inhibition of fat digestion by orlistat may-as a result of more rapid gastric emptying-exacerbate postprandial glycaemia and the postprandial fall in blood pressure in patients with type 2 diabetes after ingestion of meals containing fat and carbohydrate. Topics: Aged; Blood Glucose; Blood Pressure; Diabetes Mellitus, Type 2; Dietary Carbohydrates; Dietary Fats; Enzyme Inhibitors; Female; Gastric Emptying; Glucagon; Glucagon-Like Peptide 1; Heart Rate; Humans; Insulin; Insulin Secretion; Lactones; Lipase; Male; Middle Aged; Orlistat; Peptide Fragments; Protein Precursors | 2004 |
Effects of metformin on glucagon-like peptide-1 levels in obese patients with and without Type 2 diabetes.
Metformin has been shown to increase glucagon-like peptide-1 (GLP-1) levels after an oral glucose load in obese non-diabetic subjects. In order to verify if this effect of the drug was also present in obese Type 2 diabetic patients who have never been treated with hypoglycemic drugs, 22 Type 2 diabetic and 12 matched non-diabetic obese patients were studied. GLP-1 was measured before and after a 100 g glucose load at baseline, after a single oral dose of 850 mg of metformin, and after 4 weeks of treatment with metformin 850 mg three times daily. Post-load GLP-1 levels were significantly lower in diabetic patients. A single dose of metformin did not modify GLP-1 levels. After 4 weeks of treatment, fasting GLP-1 increased in diabetic patients (3.8 vs 4.9 pmol/l; p<0.05), while the incremental area under the curve of GLP-1 significantly increased in both diabetic [93.6 (45.6-163.2) vs 151.2 (36.0-300.5) pmol x min/l; p<0.05] and non-diabetic [187.2 (149.4-571.8) vs 324.0 (238.2-744.0) pmol x min/l; p<0.05] subjects. In conclusion, GLP-1 levels after an oral glucose load in obese type 2 diabetic patients were increased by 4 weeks of metformin treatment in a similar fashion as in obese subjects with normal glucose tolerance. Topics: Adult; Aged; Blood Glucose; Body Mass Index; Diabetes Mellitus, Type 2; Fasting; Female; Glucagon; Glucagon-Like Peptide 1; Glucose Tolerance Test; Glycated Hemoglobin; Humans; Hypoglycemic Agents; Insulin; Male; Metformin; Middle Aged; Obesity; Peptide Fragments; Protein Precursors | 2004 |
On the role of the incretin hormones GIP and GLP-1 in the pathogenesis of Type 2 diabetes mellitus.
Topics: Diabetes Mellitus, Type 2; Gastric Inhibitory Polypeptide; Glucagon-Like Peptide 1; Glucagon-Like Peptide 2; Glucagon-Like Peptides; Humans; Insulin; Insulin Secretion | 2004 |
Decreased glucagon-like peptide 1 fasting levels in type 2 diabetes.
Topics: Aged; Diabetes Mellitus, Type 2; Fasting; Female; Glucagon; Glucagon-Like Peptide 1; Humans; Male; Middle Aged; Peptide Fragments; Protein Precursors | 2003 |
Similar elimination rates of glucagon-like peptide-1 in obese type 2 diabetic patients and healthy subjects.
We have previously shown that type 2 diabetic patients have decreased plasma concentrations of glucagon-like peptide 1 (GLP-1) compared with healthy subjects after ingestion of a standard mixed meal. This decrease could be caused by differences in the metabolism of GLP-1. The objective of this study was to examine the pharmacokinetics of GLP-1 in healthy subjects and type 2 diabetic patients after iv bolus doses ranging from 2.5-25 nmol/subject. Bolus injections iv of 2.5, 5, 15, and 25 nmol of GLP-1 and a meal test were performed in six type 2 diabetic patients [age, mean (range): 56 (48-67) yr; body mass index: 31.2 (27.0-37.7) kg/m(2); fasting plasma glucose: 11.9 (8.3-14.3) mmol/liter; hemoglobin A(1C): 9.6 (7.0-12.5)%]. For comparison, six matched healthy subjects were examined. Peak plasma GLP-1 concentrations increased linearly with increasing doses of GLP-1 and were similar for type 2 diabetic patients and healthy subjects. The peak concentrations of total GLP-1 (C-terminal) after 2.5, 5, 15, and 25 nmol of GLP-1 were 357 +/- 56, 647 +/- 141, 1978 +/- 276, 3435 +/- 331 pmol/liter in the type 2 diabetic patients and 315 +/- 37, 676 +/- 64, 1848 +/- 146, 3168 +/- 358 pmol/liter, respectively, in the healthy subjects (not statistically significant). Peak concentrations of the intact GLP-1 peptide (N-terminal) were: 69 +/- 17, 156 +/- 44, 703 +/- 77, and 1070 +/- 117 pmol/liter in the type 2 diabetic patients and 75 +/- 14, 160 +/- 40, 664 +/- 79, 974 +/- 87 in the healthy subjects (not statistically significant). GLP-1 was eliminated rapidly with clearances of intact GLP-1 after 2.5, 5, 15, and 25 nmol of GLP-1 amounting to: 9.0 +/- 5.0, 8.1 +/- 6.0, 4.0 +/- 1.0, 4.0 +/- 1.0 liter/min in type 2 diabetic patients and 8.4 +/- 4.2, 7.6 +/- 4.5, 5.0 +/- 2.0, 5.0 +/- 1.0 liter/min in healthy subjects. The volume of distribution ranged from 9-26 liters per subject. No significant differences were found between healthy subjects and type 2 diabetic subjects. We conclude that elimination of GLP-1 is the same in obese type 2 diabetic patients and matched healthy subjects. The impaired incretin response seen after ingestion of a standard breakfast meal must therefore be caused by a decreased secretion of GLP-1 in type 2 diabetic patients. Topics: Aged; Diabetes Mellitus; Diabetes Mellitus, Type 2; Dose-Response Relationship, Drug; Female; Glucagon; Glucagon-Like Peptide 1; Humans; Injections, Intravenous; Male; Middle Aged; Obesity; Osmolar Concentration; Peptide Fragments; Protein Precursors; Reference Values | 2003 |
Enteroinsular axis of db/db mice and efficacy of dipeptidyl peptidase IV inhibition.
In type 2 diabetic patients, the administration of glucagon-like peptide-1 (GLP-1), known as an incretin, exerts antidiabetic effects. However, GLP-1 is rapidly degraded by dipeptidyl peptidase IV (DPPIV) after its release. DPPIV inhibition is thought to be a rational strategy to treat type 2 diabetes. In this study, using C57BLKS/J-db/db (db/db) mice as a model of type 2 diabetes, we examined the effect of acute DPPIV inhibition on glucose tolerance at the early and later stages of diabetes, determining plasma active GLP-1 and insulin levels. In addition, we investigated changes of plasma DPPIV activity. Compared with normal C57BL6/J (B6) and db/+ mice, significantly increased plasma DPPIV activities were observed in db/db mice. Expression of the proglucagon gene encoding GLP-1 was significantly upregulated in the colon of db/db mice. The administration of valine-pyrrolidide, a DPPIV inhibitor, resulted in potentiated insulin secretion mediated by increased endogenous GLP-1 action, leading to improved glucose tolerance in db/db mice at 6 weeks of age. However, although acute DPPIV inhibition with valine-pyrrolidide resulted in higher plasma active GLP-1 and insulin levels in db/db mice at 23 weeks of age, it did not improve glucose tolerance. The function of the enteroinsular axis is preserved in both stage of diabetes and the DPPIV inhibitor potentiated it, but the progression of insulin resistance appeared to block the improvement of glucose tolerance through DPPIV inhibition. Our results suggest that DPPIV inhibition is a suitable approach for treatment of impaired glucose tolerance (IGT), and type 2 diabetes in the early stage. Topics: Actins; Aging; Animals; Blood Glucose; Diabetes Mellitus, Type 2; Dipeptidyl Peptidase 4; Glucagon; Glucagon-Like Peptide 1; Glucose Tolerance Test; Insulin; Male; Mice; Mice, Inbred C57BL; Peptide Fragments; Proglucagon; Protease Inhibitors; Protein Precursors; Pyrroles; Valine | 2003 |
The influence of GLP-1 on glucose-stimulated insulin secretion: effects on beta-cell sensitivity in type 2 and nondiabetic subjects.
The intestinally derived hormone glucagon-like peptide 1 (GLP-1) (7-36 amide) has potent effects on glucose-mediated insulin secretion, insulin gene expression, and beta-cell growth and differentiation. It is, therefore, considered a potential therapeutic agent for the treatment of type 2 diabetes. However, the dose-response relationship between GLP-1 and basal and glucose-stimulated prehepatic insulin secretion rate (ISR) is currently not known. Seven patients with type 2 diabetes and seven matched nondiabetic control subjects were studied. ISR was determined during a graded glucose infusion of 2, 4, 6, 8, and 12 mg x kg(-1) x min(-1) over 150 min on four occasions with infusion of saline or GLP-1 at 0.5, 1.0, and 2.0 pmol x kg(-1) x min(-1). GLP-1 enhanced ISR in a dose-dependent manner during the graded glucose infusion from 332 +/- 51 to 975 +/- 198 pmol/kg in the patients with type 2 diabetes and from 711 +/- 123 to 2,415 +/- 243 pmol/kg in the control subjects. The beta-cell responsiveness to glucose, expressed as the slope of the linear relation between ISR and the glucose concentration, increased in proportion to the GLP-1 dose to 6 times relative to saline at the highest GLP-1 dose in the patients and 11 times in the control subjects, but it was 3 to 5 times lower in the patients with type 2 diabetes compared with healthy subjects at the same GLP-1 dose. During infusion of GLP-1 at 0.5 pmol x kg(-1) x min(-1) in the patients, the slope of ISR versus glucose became indistinguishable from that of the control subjects without GLP-1. Our results show that GLP-1 increases insulin secretion in patients with type 2 diabetes and control subjects in a dose-dependent manner and that the beta-cell responsiveness to glucose may be increased to normal levels with a low dose of GLP-1 infusion. Nevertheless, the results also indicate that the dose-response relation between beta-cell responsiveness to glucose and GLP-1 is severely impaired in patients with type 2 diabetes. Topics: Area Under Curve; Blood Glucose; C-Peptide; Diabetes Mellitus, Type 2; Female; Glucagon; Glucagon-Like Peptide 1; Glucose Clamp Technique; Humans; Infusions, Intravenous; Insulin; Insulin Secretion; Islets of Langerhans; Kinetics; Male; Peptide Fragments; Protein Precursors; Reference Values | 2003 |
Pharmacologic treatment of type 2 diabetes.
Topics: Diabetes Mellitus, Type 2; Exenatide; Gastric Inhibitory Polypeptide; Ghrelin; Glucagon; Glucagon-Like Peptide 1; Glucose; Humans; Insulin; Insulin Secretion; Monosaccharide Transport Proteins; Obesity; Peptide Fragments; Peptide Hormones; Peptides; Peroxisome Proliferators; Protein Precursors; Receptors, Cell Surface; Thiazoles; Venoms | 2003 |
GLP-1 gene delivery for the treatment of type 2 diabetes.
Glucagon-like peptide-1 (GLP-1) is a potent insulinotrophic hormone, which makes GLP-1 an attractive candidate for the treatment of type 2 diabetes. However, the short plasma half-life of the active forms of GLP-1 poses an obstacle to the sustained delivery of this peptide. In this study, we evaluated the effect of GLP-1 gene delivery both in vitro and in vivo using a new plasmid constructed with a modified GLP-1 (7-37) cDNA. This cDNA contains a furin cleavage site between the start codon and the GLP-1 coding region. The expression of the GLP-1 gene was driven by a chicken beta-actin promoter (pbetaGLP1). The level of the GLP-1 mRNA was evaluated by RT-PCR 24 h after transfection. The in vitro results showed a dose-dependent expression of GLP-1. Coculture assay of the GLP-1 plasmid-transfected cells with isolated rat islet cells demonstrated that GLP-1 increased insulin secretion by twofold, compared to controls during a hyperglycemic challenge. A single injection of polyethyleneimine/pbetaGLP1 complex into ZDF rats resulted in increasing insulin secretion and decreasing blood glucose level that was maintained for 2 weeks. This GLP-1 gene delivery system may provide an effective and safe treatment modality for type 2 diabetes. Topics: Animals; Blood Glucose; Cell Culture Techniques; Cell Line; Diabetes Mellitus, Type 2; Genetic Vectors; Glucagon; Glucagon-Like Peptide 1; Injections, Intravenous; Islets of Langerhans; Peptide Fragments; Plasmids; Protein Precursors; Rats | 2003 |
Incretin secretion in relation to meal size and body weight in healthy subjects and people with type 1 and type 2 diabetes mellitus.
Glucagon-like peptide-1 (GLP-1) and glucose-dependent insulinotropic polypeptide (GIP) are incretin hormones secreted in response to meal ingestion, thereby enhancing postprandial insulin secretion. Therefore, an attenuated incretin response could contribute to the impaired insulin responses in patients with diabetes mellitus. The aim of the present investigation was to investigate incretin secretion, in obesity and type 1 and type 2 diabetes mellitus, and its dependence on the magnitude of the meal stimulus. Plasma concentrations of incretin hormones (total, reflecting secretion and intact, reflecting potential action) were measured during two meal tests (260 kcal and 520 kcal) in eight type 1 diabetic patients, eight lean healthy subjects, eight obese type 2 diabetic patients, and eight obese healthy subjects. Both in diabetic patients and in healthy subjects, significant increases in GLP-1 and GIP concentrations were seen after ingestion of both meals. The incretin responses were significantly higher in all groups after the large meal, compared with the small meal, with correspondingly higher C-peptide responses. Both type 1 and type 2 diabetic patients had normal GIP responses, compared with healthy subjects, whereas decreased GLP-1 responses were seen in type 2 diabetic patients, compared with matched obese healthy subjects. Incremental GLP-1 responses were normal in type 1 diabetic patients. Increased fasting concentrations of GIP and an early enhanced postprandial GIP response were seen in obese, compared with lean healthy subjects, whereas GLP-1 responses were the same in the two groups. beta-cell sensitivity to glucose, evaluated as the slope of insulin secretion rates vs. plasma glucose concentration, tended to increase in both type 2 diabetic patients (29%, P = 0.19) and obese healthy subjects (22% P = 0.04) during the large meal, compared with the small meal, perhaps reflecting the increased incretin response. We conclude: 1) that a decreased GLP-1 secretion may contribute to impaired insulin secretion in type 2 diabetes mellitus, whereas GIP and GLP-1 secretion is normal in type 1 diabetic patients; and 2) that it is possible to modulate the beta-cell sensitivity to glucose in obese healthy subjects, and possibly also in type 2 diabetic patients, by giving them a large meal, compared with a small meal. Topics: Adult; Aged; Blood Glucose; Body Weight; C-Peptide; Case-Control Studies; Diabetes Mellitus; Diabetes Mellitus, Type 1; Diabetes Mellitus, Type 2; Feeding Behavior; Female; Gastric Inhibitory Polypeptide; Glucagon; Glucagon-Like Peptide 1; Glucagon-Like Peptides; Humans; Insulin; Insulin Secretion; Islets of Langerhans; Male; Middle Aged; Obesity; Peptide Fragments; Protein Precursors; Random Allocation | 2003 |
GLP-1 derivative liraglutide in rats with beta-cell deficiencies: influence of metabolic state on beta-cell mass dynamics.
(1) Liraglutide is a long-acting GLP-1 derivative, designed for once daily administration in type II diabetic patients. To investigate the effects of liraglutide on glycemic control and beta-cell mass in rat models of beta-cell deficiencies, studies were performed in male Zucker diabetic fatty (ZDF) rats and in 60% pancreatectomized rats. (2) When liraglutide was dosed s.c. at 150 microg kg-1 b.i.d. for 6 weeks in ZDF rats 6-8 weeks of age at study start, diabetes development was markedly attenuated. Blood glucose was approximately 12 mm lower compared to vehicle (P<0.0002), and plasma insulin was 2-3-fold higher during a normal 24-h feeding period (P<0.001). Judged by pair feeding, approximately 53% of the antihyperglycemic effect observed on 24-h glucose profiles was mediated by a reduction in food intake, which persisted throughout the study and averaged 16% (P<0.02). (3) Histological analyses revealed that beta-cell mass and proliferation were significantly lower in prediabetic animals still normoglycemic after 2 weeks treatment compared to vehicle-treated animals that had begun to develop diabetes. When the treatment period was 6 weeks, the liraglutide-treated animals were no longer completely normoglycemic and the beta-cell mass was significantly increased compared to overtly diabetic vehicle-treated animals, while beta-cell proliferation was unaffected. (4) In the experiments with 60% pancreatectomized rats, 8 days treatment with liraglutide resulted in a significantly lower glucose excursion in response to oral glucose compared to vehicle treatment. Again, part of the antihyperglycemic effect was due to reduced food intake. No effect of liraglutide on beta-cell mass was observed in these virtually normoglycemic animals. (5) In conclusion, treatment with liraglutide has marked antihyperglycemic effects in rodent models of beta-cell deficiencies, and the in vivo effect of liraglutide on beta-cell mass may in part depend on the metabolic state of the animals. Topics: Animals; Blood Glucose; Body Weight; Diabetes Mellitus, Type 2; Glucagon; Glucagon-Like Peptide 1; Insulin; Islets of Langerhans; Male; Peptide Fragments; Protein Precursors; Rats; Rats, Sprague-Dawley; Rats, Zucker | 2003 |
Novel dipeptidyl peptidase IV resistant analogues of glucagon-like peptide-1(7-36)amide have preserved biological activities in vitro conferring improved glucose-lowering action in vivo.
Although the incretin hormone glucagon-like peptide-1 (GLP-1) is a potent stimulator of insulin release, its rapid degradation in vivo by the enzyme dipeptidyl peptidase IV (DPP IV) greatly limits its potential for treatment of type 2 diabetes. Here, we report two novel Ala(8)-substituted analogues of GLP-1, (Abu(8))GLP-1 and (Val(8))GLP-1 which were completely resistant to inactivation by DPP IV or human plasma. (Abu(8))GLP-1 and (Val(8))GLP-1 exhibited moderate affinities (IC(50): 4.76 and 81.1 nM, respectively) for the human GLP-1 receptor compared with native GLP-1 (IC(50): 0.37 nM). (Abu(8))GLP-1 and (Val(8))GLP-1 dose-dependently stimulated cAMP in insulin-secreting BRIN BD11 cells with reduced potency compared with native GLP-1 (1.5- and 3.5-fold, respectively). Consistent with other mechanisms of action, the analogues showed similar, or in the case of (Val(8))GLP-1 slightly impaired insulin releasing activity in BRIN BD11 cells. Using adult obese (ob/ob) mice, (Abu(8))GLP-1 had similar glucose-lowering potency to native GLP-1 whereas the action of (Val(8))GLP-1 was enhanced by 37%. The in vivo insulin-releasing activities were similar. These data indicate that substitution of Ala(8) in GLP-1 with Abu or Val confers resistance to DPP IV inactivation and that (Val(8))GLP-1 is a particularly potent N-terminally modified GLP-1 analogue of possible use in type 2 diabetes. Topics: Amino Acid Substitution; Animals; Cells, Cultured; Cricetinae; Cyclic AMP; Diabetes Mellitus, Type 2; Dipeptidyl Peptidase 4; Enzymes; Glucagon; Glucagon-Like Peptide 1; Glucagon-Like Peptide-1 Receptor; Glucagon-Like Peptides; Insulin; Insulin Secretion; Mice; Mice, Obese; Peptide Fragments; Receptors, Glucagon; Spectrometry, Mass, Electrospray Ionization | 2003 |
Drug discovery and development for metabolic diseases.
Topics: Adult; Animals; Appetite; Child; Congresses as Topic; Diabetes Mellitus, Type 2; Glucagon; Glucagon-Like Peptide 1; Humans; Obesity; Peptide Fragments; Peptide YY; Pharmacology, Clinical; Protein Precursors; Receptors, Glucocorticoid | 2003 |
Metabolic stability, receptor binding, cAMP generation, insulin secretion and antihyperglycaemic activity of novel N-terminal Glu9-substituted analogues of glucagon-like peptide-1.
Glucagon-like peptide-1(7-36)amide (GLP-1) is an incretin hormone with therapeutic potential for type 2 diabetes. Rapid removal of the N-terminal dipeptide, His7-Ala8, by the ubiquitous enzyme dipeptidyl peptidase IV (DPP IV) curtails the biological activity of GLP-1. Chemical modifications or substitutions of GLP-1 at His7 or Ala8 improve resistance to DPP-IV action, but this often reduces potency. Little attention has focused on the metabolic stability and functional activity of GLP-1 analogues with amino acid substitution at Glu9, adjacent to the DPP IV cleavage site. We generated three novel Glu9-substituted GLP-1 analogues, (Pro9)GLP-1, (Phe9)GLP-1 and (Tyr9)GLP-1 and show for the first time that Glu9 of GLP-1 is important in DPP IV degradation, since replacing this amino acid, particularly with proline, substantially reduced susceptibility to degradation. All three novel GLP-1 analogues showed similar or slightly enhanced insulinotropic activity compared with native GLP-1 despite a moderate 4-10-fold reduction in receptor binding and cAMP generation. In addition, (Pro9)GLP-1 showed significant ability to moderate the plasma glucose excursion and increase circulating insulin concentrations in severely insulin resistant obese diabetic (ob/ob) mice. These observations indicate the importance of Glu9 for the biological activity of GLP-1 and susceptibility to DPP IV-mediated degradation. Topics: Adenosine Deaminase; Amino Acid Substitution; Animals; Binding, Competitive; Blood Glucose; Cell Line, Tumor; Cricetinae; Cyclic AMP; Diabetes Mellitus, Type 2; Dipeptidyl Peptidase 4; Fibroblasts; Glucagon; Glucagon-Like Peptide 1; Glucagon-Like Peptide-1 Receptor; Glucose; Glutamine; Glycoproteins; Humans; Hypoglycemic Agents; Insulin; Insulin Secretion; Islets of Langerhans; Mice; Mice, Obese; Peptide Fragments; Phenylalanine; Proline; Protein Precursors; Rats; Receptors, Glucagon; Spectrometry, Mass, Electrospray Ionization; Transformation, Genetic; Tyrosine | 2003 |
On combination therapy of diabetes with metformin and dipeptidyl peptidase IV inhibitors.
Topics: Diabetes Mellitus, Type 2; Dipeptidyl Peptidase 4; Drug Therapy, Combination; Glucagon; Glucagon-Like Peptide 1; Humans; Hypoglycemic Agents; Metformin; Peptide Fragments; Protein Precursors | 2002 |
Glycemic, hormone, and appetite responses to monosaccharide ingestion in patients with type 2 diabetes.
To investigate the relative effects of fructose and glucose on blood glucose, plasma insulin and incretin (glucagon-like peptide-1 [GLP-1] and gastric inhibitory peptide [GIP]) concentrations, and acute food intake, 10 (6 men, 4 women) patients with diet-controlled type 2 diabetes (diabetic) (44 to 71 years) and 10 age and body mass index (BMI)-matched (6 men, 4 women) nondiabetic, control subjects with varying degrees of glucose tolerance (nondiabetic), were studied on 3 days. In random order, they drank equienergetic preloads of glucose (75 g) (GLUC), fructose (75 g) (FRUCT) or vehicle (300 mL water with noncaloric flavoring [VEH]) 3 hours before an ad libitum buffet lunch. Mean glucose concentrations were lower after FRUCT than GLUC in both type 2 diabetics (FRUCT v GLUC: 7.5 +/- 0.3 v 10.8 +/- 0.4 mmol/L, P <.001) and nondiabetics (FRUCT v GLUC: 5.9 +/- 0.2 v 7.2 +/- 0.3 mmol/L, P <.05). Mean insulin concentrations were approximately 50% higher after FRUCT in type 2 diabetics than in nondiabetics (diabetics v nondiabetics: 23.1 +/- 0.7 v 15.1 +/- 1.3 microU/mL; P <.0001). Plasma GLP-1 concentrations after fructose were not different between type 2 diabetics and nondiabetics (P >.05). Glucose, but not FRUC, increased GIP concentrations, which were not different between type 2 diabetics and nondiabetics (P >.05). Food intake was suppressed 14% by GLUC (P <.05 v CONT) and 14% by FRUC (P <.05 v CONT), with no difference between the amount of food consumed after GLUC and FRUC treatment in either type 2 diabetics or nondiabetics (P >.05). We have confirmed that oral fructose ingestion produces a lower postprandial blood glucose response than equienergetic glucose and demonstrated that (1) fructose produces greater increases in plasma insulin concentration in type 2 diabetics than nondiabetics, not apparently due to greater plasma incretin concentrations and (2) fructose and glucose have equivalent short-term satiating efficiency in both type 2 diabetics and nondiabetics. We conclude that on the basis of improved glycemic control, but not satiating efficiency, fructose may be useful as a replacement for glucose in the diet of obese patients with type 2 diabetes. Topics: Adult; Aged; Appetite; Blood Glucose; Diabetes Mellitus, Type 2; Female; Fructose; Gastric Inhibitory Polypeptide; Glucagon; Glucagon-Like Peptide 1; Glucagon-Like Peptides; Glucose; Humans; Insulin; Male; Middle Aged; Peptide Fragments | 2002 |
Rebuttal to Deacon and Holst: "Metformin effects on dipeptidyl peptidase IV degradation of glucagon-like peptide-1" versus "Dipeptidyl peptidase inhibition as an approach to the treatment and prevention of type 2 diabetes: a historical perspective".
Topics: Animals; Diabetes Mellitus, Type 2; Dipeptidyl Peptidase 4; Gastric Inhibitory Polypeptide; Glucagon; Glucagon-Like Peptide 1; Humans; Hypoglycemic Agents; Metformin; Peptide Fragments; Protease Inhibitors; Protein Precursors | 2002 |
Defective amplification of the late phase insulin response to glucose by GIP in obese Type II diabetic patients.
Glucagon-like-peptide-1 (GLP-1) is strongly insulinotropic in patients with Type II (non-insulin-dependent) diabetes mellitus, whereas glucose-dependent insulinotropic polypeptide (GIP) is less effective. Our investigation evaluated "early" (protocol 1) - and "late phase" (protocol 2) insulin and C-peptide responses to GLP-1 and GIP stimulation in patients with Type II diabetes.. Protocol 1: eight Type II diabetic patients and eight matched healthy subjects received i.v. bolus injections of GLP-1(2.5 nmol) or GIP(7.5 nmol) concomitant with an increase of plasma glucose to 15 mmol/l. Protocol 2: eight Type II diabetic patients underwent a hyperglycaemic clamp (15 mmol/l) with infusion (per kg body weight/min) of either: 1 pmol GLP-1 (7-36) amide (n=8), 4 pmol GIP (n=8), 16 pmol GIP (n=4) or no incretin hormone (n=5). For comparison, six matched healthy subjects were examined.. Protocol 1: Type II diabetic patients were characterised by a decreased "early phase" response to both stimuli, but their relative response to GIP versus GLP-1 stimulation was exactly the same as in healthy subjects [insulin (C-peptide): patients 59+/-9% (74+/-6%) and healthy subjects 62+/-5% (71+/-9%)]. Protocol 2, "Early phase" (0-20 min) insulin response to glucose was delayed and reduced in the patients, but enhanced slightly and similarly by GIP and GLP-1. GLP-1 augmented the "late phase" (20-120 min) insulin secretion to levels similar to those observed in healthy subjects. In contrast, the "late phase" responses to both doses of GIP were not different from those obtained with glucose alone. Accordingly, glucose infusion rates required to maintain the hyperglycaemic clamp in the "late phase" period (20-120 min) were similar with glucose alone and glucose plus GIP, whereas a doubling of the infusion rate was required during GLP-1 stimulation.. Lack of GIP amplification of the late phase insulin response to glucose, which contrasts markedly to the normalising effect of GLP-1, could be a key defect in insulin secretion in Type II diabetic patients. Topics: Aged; Blood Glucose; C-Peptide; Diabetes Mellitus; Diabetes Mellitus, Type 2; Drug Synergism; Female; Glucagon; Glucagon-Like Peptide 1; Glucose; Humans; Hypoglycemic Agents; Injections, Intravenous; Insulin; Male; Middle Aged; Obesity; Peptide Fragments; Protein Precursors; Reference Values; Time Factors | 2002 |
The long-acting GLP-1 derivative NN2211 ameliorates glycemia and increases beta-cell mass in diabetic mice.
NN2211 is a long-acting, metabolically stable glucagon-like peptide-1 (GLP-1) derivative designed for once daily administration in humans. NN2211 dose dependently reduced the glycemic levels in ob/ob mice, with antihyperglycemic activity still evident 24 h postdose. Apart from an initial reduction in food intake, there were no significant differences between NN2211 and vehicle treatment, and body weight was not affected. Histological examination revealed that beta-cell proliferation and mass were not increased significantly in ob/ob mice with NN2211, although there was a strong tendency for increased proliferation. In db/db mice, exendin-4 and NN2211 decreased blood glucose compared with vehicle, but NN2211 had a longer duration of action. Food intake was lowered only on day 1 with both compounds, and body weight was unaffected. beta-Cell proliferation rate and mass were significantly increased with NN2211, but with exendin-4, only the beta-cell proliferation rate was significantly increased. In conclusion, NN2211 reduced blood glucose after acute and chronic treatment in ob/ob and db/db mice and was associated with increased beta-cell mass and proliferation in db/db mice. NN2211 is currently in phase 2 clinical development. Topics: Animals; Blood Glucose; Body Weight; Cell Division; Diabetes Mellitus, Type 2; Eating; Exenatide; Female; Glucagon; Glucagon-Like Peptide 1; Hyperglycemia; Insulin; Islets of Langerhans; Liraglutide; Mice; Mice, Inbred C57BL; Mice, Obese; Peptide Fragments; Peptides; Protein Precursors; Venoms | 2002 |
NN2211: a long-acting glucagon-like peptide-1 derivative with anti-diabetic effects in glucose-intolerant pigs.
Glucagon-like peptide-1 (GLP-1) is an effective anti-diabetic agent, but its metabolic instability makes it therapeutically unsuitable. This study investigated the pharmacodynamics of a long-acting GLP-1 derivative (NN2211: (Arg(34)Lys(26)-(N- epsilon -(gamma-Glu(N-alpha-hexadecanoyl)))-GLP-1(7-37)), after acute and chronic treatment in hyperglycaemic minipigs. During hyperglycaemic glucose clamps, NN2211 (2 micrograms kg(-1) i.v.) treated pigs required more (P < 0.005) glucose than control animals (5.8 +/- 2.1 vs. 2.9 +/- 1.8 mg kg(-1) min(-1)). Insulin excursions were higher (P < 0.01) after NN2211 (15,367 +/- 5,438 vs. 9,014 +/- 2,952 pmol l(-1) min), and glucagon levels were suppressed (P < 0.05). Once-daily injections of NN2211 (3.3 micrograms kg(-1) s.c.) reduced the glucose excursion during an oral glucose tolerance test, to 59 +/- 15% of pre-treatment values by 4 weeks (P < 0.05), without measurable changes in insulin responses. Fructosamine concentrations were unaltered by vehicle, but decreased (from 366 +/- 187 to 302 +/- 114 micromol l(-1), P = 0.14) after 4 weeks of NN2211. Gastric emptying was reduced (P < 0.05) by NN2211. NN2211 acutely increases glucose utilization during a hyperglycaemic glucose clamp and chronic treatment results in better daily metabolic control. Therefore, NN2211, a GLP-1 derivative that can be administered once daily, holds promise as a new anti-diabetic drug with a minimal risk of hypoglycaemia. Topics: Animals; Blood Glucose; Diabetes Mellitus, Type 2; Glucagon; Glucagon-Like Peptide 1; Glucose Intolerance; Hypoglycemic Agents; Insulin; Liraglutide; Male; Peptide Fragments; Protein Precursors; Swine, Miniature | 2002 |
Theratechnologies expands peptide portfolio in endocrinology.
Topics: Administration, Cutaneous; Clinical Trials, Phase II as Topic; Diabetes Mellitus, Type 2; Glucagon; Glucagon-Like Peptide 1; Humans; Hypoglycemic Agents; Peptide Fragments; Protein Precursors | 2002 |
Glucagon-like peptide 1 content of intestinal tract in adult rats injected with streptozotocin either during neonatal period or 7 d before sacrifice.
Glucagon-like peptide 1 (GLP-1) content of the intestinal tract was recently found to be lower in diabetesprone BioBreeding (BBdp) rats than in the corresponding control animals (BBc rats), a finding compatible with the idea that an inflammatory intestinal state precedes insulitis in these diabetes-prone animals. This study aimed at measuring GLP-1 content of the intestinal tract both in another animal model of type 1 diabetes and in an animal model of type 2 diabetes. GLP-1 content of the jejunum, ileum, colon, and cecum was measured in male and female adult control rats and animals injected with streptozotocin (STZ) either during the neonatal period or 7 d before sacrifice. GLP-1 content of the intestinal tract was higher in type 1 diabetic rats than in control animals. Such was not the case in the type 2 diabetic rats. The findings recorded in the rats injected with STZ either during the neonatal period or later in life indicate that hyperglycemia and/or insulin deficiency do not cause a decrease in GLP-1 content of the intestinal tract. On the contrary, such a content may increase when the glucose intolerance and hypoinsulinemia are sufficiently pronounced, as was the case in the type 1 diabetic rats. These findings are thus compatible with the view that the decreased GLP-1 content of the intestinal tract in BBdp rats may result from intestinal inflammation. Topics: Animals; Animals, Newborn; Blood Glucose; Body Weight; Cecum; Colon; Diabetes Mellitus, Experimental; Diabetes Mellitus, Type 1; Diabetes Mellitus, Type 2; Female; Glucagon; Glucagon-Like Peptide 1; Ileum; Insulin; Intestines; Jejunum; Male; Pancreas; Peptide Fragments; Protein Precursors; Proteins; Rats; Rats, Inbred BB; Rats, Wistar; Streptozocin | 2002 |
Glucagon-like peptide-1 response to acarbose in elderly type 2 diabetic subjects.
The anti-hyperglycemic effect of alpha-glucosidase inhibitors (AGI) is partly attributed to their ability to stimulate the secretion of glucagon-like peptide-1 (GLP-1), a gut hormone with insulin stimulating capability. To determine if this mechanism of action contributes significantly to the therapeutic efficacy of AGI in the elderly, 10 type 2 diabetic subjects over the age of 65 years were given a standardized test meal with or without 25, 50, or 100 mg acarbose. The serum glucose, insulin, triglycerides and GLP-1 levels were measured at baseline and at 1 and 2 h postprandially. The anti-hyperglycemic effect of acarbose was maximal at 25-mg dose under these experimental conditions. Serum postprandial insulin and triglycerides levels were not significantly altered with acarbose treatment. The postprandial serum GLP-1 levels rose significantly only in two subjects and only during treatment with 100-mg acarbose. There were no significant correlations between serum GLP-1 and serum glucose or insulin levels. It is concluded that in most elderly type 2 diabetic subjects, maximal anti-hyperglycemic effects can be achieved with relatively small doses of acarbose and that GLP-1 is unlikely to contribute to the clinical efficacy of this agent in this subgroup of subjects. Topics: Acarbose; Aged; Blood Glucose; Diabetes Mellitus, Type 2; Eating; Glucagon; Glucagon-Like Peptide 1; Humans; Hypoglycemic Agents; Insulin; Peptide Fragments; Postprandial Period; Protein Precursors; Triglycerides | 2002 |
Evidence for early impairment of glucagon-like peptide 1-induced insulin secretion in human type 2 (non insulin-dependent) diabetes.
To investigate a possible role of an enteroinsular axis involvement in the pathogenesis of type 2 diabetes, plasma glucagon-like peptide 1 (GLP-1) 7-36 amide response to nutrient ingestion was evaluated in type 2 diabetics affected by different degrees of beta-cell dysfunction.. 14 patients on oral hypoglycaemic treatment (group A: HbA1C = 8.1 +/- 1.8 %) and 11 age-matched diabetic patients on diet only (group B: HbA1C = 6.4 +/- 0.9) participated in the study. 10 healthy volunteers were studied as controls. In the postabsorptive state, a mixed meal (700 kCal) was administered to all subjects, and blood samples were regularly collected up to 180' for plasma glucose, insulin, glucagon, and GLP-1 determination.. In the control group, the test meal induced a significant increase in plasma GLP-1 at 30' and 60' (p < 0.01); the peptide concentrations then returning toward basal levels. beta-cell function estimation by HOMA score confirmed a more advanced involvement in group A than in group B (p < 0.01). In contrast, the insulin resistance degree showed a similar result in the two groups (HOMA-R). In group A, first-phase postprandial insulin secretion (0 - 60') resulted, as expected, in being significantly reduced compared to healthy subjects (p < 0.001). In the same patients the mean fasting GLP-1 value was similar to controls, but the meal failed to increase plasma peptide levels, which even tended to decrease during the test (p < 0.01). In group B, food-mediated early insulin secretion was higher than in group A (p < 0.001), although significantly reduced when compared to controls (p < 0.01). Like group A, no GLP-1 response to food ingestion occurred in group B patients in spite of maintained basal peptide secretion. Whereas the test-meal did not significantly modify plasma glucagon levels in the control group, glucagon concentrations increased at 30' and 60' in both diabetic groups (p < 0.01).. 1) The functional integrity of GLP-1 cells results as being seriously impaired even in the condition of mild diabetes; 2) the early peptide failure could contribute to the development of beta-cell deterioration which characterizes overt type 2 diabetes. Topics: Aged; Blood Glucose; Body Mass Index; Diabetes Mellitus, Type 2; Disease Progression; Eating; Female; Glucagon; Glucagon-Like Peptide 1; Glycated Hemoglobin; Humans; Hypoglycemic Agents; Insulin; Male; Middle Aged; Peptide Fragments; Protein Precursors | 2002 |
Persistent improvement of type 2 diabetes in the Goto-Kakizaki rat model by expansion of the beta-cell mass during the prediabetic period with glucagon-like peptide-1 or exendin-4.
In the Goto-Kakizaki (GK) rat, a genetic model of type 2 diabetes, the neonatal beta-cell mass deficit is considered to be the primary defect leading to basal hyperglycemia, which is detectable for the first time 3 weeks after birth. We investigated in GK females the short- and the long-term effects of a treatment with glucagon-like peptide-1 (GLP-1) or its long-acting analog exendin-4 (Ex-4) during the first postnatal week (during the prediabetic period). GK rats were treated with daily injections of glucagon-like peptide-1 (400 microg x kg(-1) x day(-1)) or Ex-4 (3 microg x kg(-1) x day(-1)) from day 2 to day 6 after birth and were evaluated against Wistar and untreated GK rats. Under these conditions, on day 7 both treatments enhanced pancreatic insulin content and total beta-cell mass by stimulating beta-cell neogenesis and regeneration. Follow-up of biological characteristics from day 7 to adult age (2 months) showed that such a GLP-1 or Ex-4 treatment exerted long-term favorable influences on beta-cell mass and glycemic control at adult age. As compared to untreated GK rats, 2-month-old treated rats exhibited significantly decreased basal plasma glucose. Their glucose-stimulated insulin secretion, in vivo after intravenous glucose load or in vitro using isolated perfused pancreas, was slightly improved. This contributed at least partly to improve the in vivo plasma glucose disappearance rate, which was found to be increased in both treated GK groups compared to the untreated GK group. These findings in the GK model indicated, for the first time, that GLP-1 or Ex-4 treatment limited to the prediabetic period delays the installation and limits the severity of type 2 diabetes. Under these conditions, GLP-1 represents a unique tool because of its beta-cell replenishing effect in spontaneously diabetic rodents. It may prove to be an invaluable agent for the prevention of human type 2 diabetes. Topics: Age Factors; Animals; Animals, Newborn; Blood Glucose; Body Weight; Cell Division; Diabetes Mellitus, Type 2; Disease Models, Animal; Exenatide; Female; Glucagon; Glucagon-Like Peptide 1; Insulin; Insulin Secretion; Islets of Langerhans; Longitudinal Studies; Peptide Fragments; Peptides; Protein Precursors; Rats; Rats, Mutant Strains; Rats, Wistar; Venoms | 2002 |
Chronic inhibition of circulating dipeptidyl peptidase IV by FE 999011 delays the occurrence of diabetes in male zucker diabetic fatty rats.
Acute suppression of dipeptidyl peptidase IV (DPP-IV) activity improves glucose tolerance in the Zucker fatty rat, a rodent model of impaired glucose tolerance, through stabilization of glucagon-like peptide (GLP)-1. This study describes the effects of a new and potent DPP-IV inhibitor, FE 999011, which is able to suppress plasma DPP-IV activity for 12 h after a single oral administration. In the Zucker fatty rat, FE 999011 dose-dependently attenuated glucose excursion during an oral glucose tolerance test and increased GLP-1 (7-36) release in response to intraduodenal glucose. Chronic treatment with FE 999011 (10 mg/kg, twice a day for 7 days) improved glucose tolerance, as suggested by a decrease in the insulin-to-glucose ratio. In the Zucker diabetic fatty (ZDF) rat, a rodent model of type 2 diabetes, chronic treatment with FE 999011 (10 mg/kg per os, once or twice a day) postponed the development of diabetes, with the twice-a-day treatment delaying the onset of hyperglycemia by 21 days. In addition, treatment with FE 999011 stabilized food and water intake to prediabetic levels and reduced hypertriglyceridemia while preventing the rise in circulating free fatty acids. At the end of treatment, basal plasma GLP-1 levels were increased, and pancreatic gene expression for GLP-1 receptor was significantly upregulated. This study demonstrates that DPP-IV inhibitors such as FE 999011 could be of clinical value to delay the progression from impaired glucose tolerance to type 2 diabetes. Topics: Animals; Blood Glucose; Diabetes Mellitus; Diabetes Mellitus, Type 2; Dipeptidyl Peptidase 4; Drinking; Eating; Fatty Acids, Nonesterified; Gene Expression; Glucagon; Glucagon-Like Peptide 1; Glucagon-Like Peptide-1 Receptor; Glucose Tolerance Test; Humans; Insulin; Male; Nitriles; Obesity; Pancreas; Peptide Fragments; Protease Inhibitors; Protein Precursors; Pyrrolidines; Rats; Rats, Zucker; Receptors, Glucagon; Triglycerides; Weight Gain | 2002 |
Degradation and glycemic effects of His(7)-glucitol glucagon-like peptide-1(7-36)amide in obese diabetic ob/ob mice.
Glucagon-like peptide-1(7-36)amide (tGLP-1) has attracted considerable potential as a possible therapeutic agent for type 2 diabetes. However, tGLP-1 is rapidly inactivated in vivo by the exopeptidase dipeptidyl peptidase IV (DPP IV), thereby terminating its insulin releasing activity. The present study has examined the ability of a novel analogue, His(7)-glucitol tGLP-1 to resist plasma degradation and enhance the insulin-releasing and antihyperglycemic activity of the peptide in 20-25-week-old obese diabetic ob/ob mice. Degradation of native tGLP-1 by incubation at 37 degrees C with obese mouse plasma was clearly evident after 3 h (35% intact). After 6 h, more than 87% of tGLP-1 was converted to GLP-1(9-36)amide and two further N-terminal fragments, GLP-1(7-28) and GLP-1(9-28). In contrast, His(7)-glucitol tGLP-1 was completely resistant to N-terminal degradation. The formation of GLP-1(9-36)amide from native tGLP-1 was almost totally abolished by addition of diprotin A, a specific inhibitor of DPP IV. Effects of tGLP-1 and His(7)-glucitol tGLP-1 were examined in overnight fasted obese mice following i.p. injection of either peptide (30 nmol/kg) together with glucose (18 mmol/kg) or in association with feeding. Plasma glucose was significantly lower and insulin response greater following administration of His(7)-glucitol tGLP-1 as compared to glucose alone. Native tGLP-1 lacked antidiabetic effects under the conditions employed, and neither peptide influenced the glucose-lowering action of exogenous insulin (50 units/kg). Twice daily s.c. injection of ob/ob mice with His(7)-glucitol tGLP-1 (10 nmol/kg) for 7 days reduced fasting hyperglycemia and greatly augmented the plasma insulin response to the peptides given in association with feeding. These data demonstrate that His(7)-glucitol tGLP-1 displays resistance to plasma DPP IV degradation and exhibits antihyperglycemic activity and substantially enhanced insulin-releasing action in a commonly used animal model of type 2 diabetes. Topics: Animals; Blood Glucose; Chromatography, High Pressure Liquid; Diabetes Mellitus, Type 2; Dipeptidyl Peptidase 4; Eating; Glucagon; Glucagon-Like Peptide 1; Glucagon-Like Peptides; Humans; Hyperglycemia; Hypoglycemic Agents; Insulin; Mice; Mice, Obese; Oligopeptides; Peptide Fragments; Protease Inhibitors; Protein Precursors; Spectrometry, Mass, Electrospray Ionization; Time Factors | 2001 |
Reduced postprandial concentrations of intact biologically active glucagon-like peptide 1 in type 2 diabetic patients.
Incretin hormones importantly enhance postprandial insulin secretion but are rapidly degraded to inactive metabolites by ubiquitous dipeptidyl peptidase IV. The concentrations of the intact biologically active hormones remain largely unknown. Using newly developed assays for intact glucagon-like peptide (GLP)-1 and glucose-dependent insulinotropic polypeptide (GIP), we measured plasma concentrations after a mixed breakfast meal (566 kcal) in 12 type 2 diabetic patients (age 57 years [range 49-67], BMI 31 kg/m2 [27-38], and HbA1c 9.2% [7.0-12.5]) and 12 matched healthy subjects. The patients had fasting hyperglycemia (10.7 mmol/l [8.0-14.8]) increasing to 14.6 mmol/l (11.5-21.5) 75 min after meal ingestion. Fasting levels of insulin and C-peptide were similar to those of the healthy subjects, but the postprandial responses were reduced and delayed. Fasting levels and meal responses were similar between patients and healthy subjects for total GIP (intact + metabolite) as well as intact GIP, except for a small decrease in the patients at 120 min; integrated areas for intact hormone (area under the curve [AUC]INT) averaged 52 +/- 4% (for patients) versus 56 +/- 3% (for control subjects) of total hormone AUC (AUC(TOT)). AUC(INT) for GLP-1 averaged 48 +/- 2% (for patients) versus 51 +/- 5% (for control subjects) of AUC(TOT). AUC(TOT) for GLP-1 as well as AUC(INT) tended to be reduced in the patients (P = 0.2 and 0.07, respectively); but the profile of the intact GLP-1 response was characterized by a small early rise (30-45 min) and a significantly reduced late phase (75-150 min) (P < 0.02). The measurement of intact incretin hormones revealed that total as well as intact GIP responses were minimally decreased in patients with type 2 diabetes, whereas the late intact GLP-1 response was strongly reduced, supporting the hypothesis that an impaired function of GLP-1 as a transmitter in the enteroinsular axis contributes to the inappropriate insulin secretion in type 2 diabetes. Topics: Aged; C-Peptide; Diabetes Mellitus, Type 2; Fasting; Female; Gastric Inhibitory Polypeptide; Glucagon; Glucagon-Like Peptide 1; Humans; Insulin; Male; Middle Aged; Osmolar Concentration; Peptide Fragments; Postprandial Period; Protein Precursors; Reference Values | 2001 |
No reactive hypoglycaemia in Type 2 diabetic patients after subcutaneous administration of GLP-1 and intravenous glucose.
It has previously been shown that intravenous and subcutaneous administration of glucagon-like peptide (GLP)-1 concomitant with intravenous glucose results in reactive hypoglycaemia in healthy subjects. Since GLP-1 is also effective in Type 2 diabetic patients and is presently being evaluated as a therapeutic agent in this disease, it is important to investigate whether GLP-1 can cause hypoglycaemia in such patients.. Eight Type 2 diabetic patients (age 54 (49-67) years; body mass index 31 (27-38) kg/m2; HbA1c 9.4 (7.0-12.5)%) and seven matched non-diabetic subjects (HbA1c 5.5 (5.2-5.8)%, fasting plasma glucose 5.4 (5.0-5.7) mmol/l) were given a subcutaneous injection of 1.5 nmol GLP-1/kg body weight (maximally tolerated dose), and 15 min later, plasma glucose (PG) was raised to 15 mmol/l with an intravenous glucose bolus.. Hypoglycaemia with a PG at or below 2.5 mmol/l was seen in five of the seven healthy subjects after 60-70 min, but PG spontaneously increased again, reaching 3.7 (3.3-4.0) mmol/l at 90 min. In the patients, PG fell slowly and stabilized at 8.6 (4.2-12.1) mmol/l after 80 min. In both groups, glucagon levels initially decreased, but later increased, exceeding basal levels in healthy subjects, in spite of persistent, high concentrations of GLP-1 (P < 0.02).. Subcutaneous GLP-1 plus intravenous glucose induced reactive hypoglycaemia in healthy subjects, but not in Type 2 diabetic patients. Therefore, a GLP-1-based therapy would not be expected to be associated with an increased risk of hypoglycaemia in Type 2 diabetes mellitus. Topics: Aged; Blood Glucose; C-Peptide; Diabetes Mellitus, Type 2; Female; Glucagon; Glucagon-Like Peptide 1; Glucose; Humans; Hypoglycemia; Hypoglycemic Agents; Infusions, Intravenous; Injections, Subcutaneous; Insulin; Kinetics; Male; Middle Aged; Peptide Fragments; Protein Precursors; Reference Values | 2001 |
Biological activities of glucagon-like peptide-1 analogues in vitro and in vivo.
Studies support a role for glucagon-like peptide 1 (GLP-1) as a potential treatment for diabetes. However, since GLP-1 is rapidly degraded in the circulation by cleavage at Ala(2), its clinical application is limited. Hence, understanding the structure-activity of GLP-1 may lead to the development of more stable and potent analogues. In this study, we investigated GLP-1 analogues including those with N-, C-, and midchain modifications and a series of secretin-class chimeric peptides. Peptides were analyzed in CHO cells expressing the hGLP-1 receptor (R7 cells), and in vivo oral glucose tolerance tests (OGTTs) were performed after injection of the peptides in normal and diabetic (db/db) mice. [D-Ala(2)]GLP-1 and [Gly(2)]GLP-1 showed normal or relatively lower receptor binding and cAMP activation but exerted markedly enhanced abilities to reduce the glycemic response to an OGTT in vivo. Improved biological effectiveness of [D-Ala(2)]GLP-1 was also observed in diabetic db/db mice. Similarly, improved biological activity of acetyl- and hexenoic-His(1)-GLP-1, glucagon((1-5)-, glucagon((1-10))-, PACAP(1-5)-, VIP(1-5)-, and secretin((1-10))-GLP-1 was observed, despite normal or lower receptor binding and activation in vitro. [Ala(8/11/12/16)] substitutions also increased biological activity in vivo over wtGLP-1, while C-terminal truncation of 4-12 amino acids abolished receptor binding and biological activity. All other modified peptides examined showed normal or decreased activity in vitro and in vivo. These results indicate that specific N- and midchain modifications to GLP-1 can increase its potency in vivo. Specifically, linkage of acyl-chains to the alpha-amino group of His(1) and replacement of Ala(2) result in significantly increased biological effects of GLP-1 in vivo, likely due to decreased degradation rather than enhanced receptor interactions. Replacement of certain residues in the midchain of GLP-1 also augment biological activity. Topics: Amino Acid Sequence; Amino Acid Substitution; Animals; Binding, Competitive; CHO Cells; Cricetinae; Diabetes Mellitus, Type 2; Female; Glucagon; Glucagon-Like Peptide 1; Glucagon-Like Peptide-1 Receptor; Glucose Tolerance Test; Humans; Injections, Intraperitoneal; Injections, Subcutaneous; Mice; Mice, Inbred C57BL; Mice, Obese; Molecular Sequence Data; Peptide Fragments; Protein Precursors; Radioligand Assay; Receptors, Glucagon; Sequence Deletion; Structure-Activity Relationship | 2001 |
Defective stimulus-secretion coupling in islets of Psammomys obesus, an animal model for type 2 diabetes.
Psammomys obesus is a model of type 2 diabetes that displays resistance to insulin and deranged beta-cell response to glucose. We examined the major signaling pathways for insulin release in P. obesus islets. Islets from hyperglycemic animals utilized twice as much glucose as islets from normoglycemic diabetes-prone or diabetes-resistant controls but exhibited similar rates of glucose oxidation. Fractional oxidation of glucose was constant in control islets over a range of concentrations, whereas islets from hyperglycemic P. obesus showed a decline at high glucose. The mitochondrial substrates alpha-ketoisocaproate and monomethyl succinate had no effect on insulin secretion in P. obesus islets. Basal insulin release in islets from diabetes-resistant P. obesus was unaffected by glucagon-like peptide 1 (GLP-1) or forskolin, whereas that of islets of the diabetic line was augmented by the drugs. GLP-1 and forskolin potentiated the insulin response to maximal (11.1 mmol/l) glucose in islets from all groups. The phorbol ester phorbol myristic acid (PMA) potentiated basal insulin release in islets from prediabetic animals, but not those from hyperglycemic or diabetes-resistant P. obesus. At the maximal stimulatory glucose concentration, PMA potentiated insulin response in islets from normoglycemic prediabetic and diabetes-resistant P. obesus but had no effect on islets from hyperglycemic P. obesus. Maintenance of islets from hyperglycemic P. obesus for 18 h in low (3.3 mmol/l) glucose in the presence of diazoxide (375 pmol/l) dramatically improved the insulin response to glucose and restored the responsiveness to PMA. Immunohistochemical analysis indicated that hyperglycemia was associated with reduced expression of alpha-protein kinase C (PKC) and diminished translocation of lambda-PKC. In summary, we found that 1) P. obesus islets have low oxidative capacity, probably resulting in limited ability to generate ATP to initiate and drive the insulin secretion; 2) insulin response potentiated by cyclic AMP-dependent protein kinase is intact in P. obesus islets, and increased sensitivity to GLP-1 or forskolin in the diabetic line may be secondary to increased sensitivity to glucose; and 3) islets of hyperglycemic P. obesus display reduced expression of alpha-PKC and diminished translocation of lambda-PKC associated with impaired response to PMA. We conclude that low beta-cell oxidative capacity coupled with impaired PKC-dependent signaling may contribute to the ani Topics: Animals; Colforsin; Diabetes Mellitus, Type 2; Diazoxide; Disease Models, Animal; Disease Susceptibility; Gerbillinae; Glucagon; Glucagon-Like Peptide 1; Glucose; Hyperglycemia; In Vitro Techniques; Insulin; Insulin Secretion; Islets of Langerhans; Isoenzymes; Oxidation-Reduction; Peptide Fragments; Protein Kinase C; Protein Precursors; Rats; Rats, Sprague-Dawley; Reference Values; Signal Transduction; Tetradecanoylphorbol Acetate | 2001 |
Glucagon-like peptide-1 (7-37) augments insulin release in elderly patients with diabetes.
Topics: Aged; Blood Glucose; C-Peptide; Diabetes Mellitus, Type 2; Glucagon; Glucagon-Like Peptide 1; Glucagon-Like Peptides; Glucose Clamp Technique; Humans; Infusions, Intravenous; Insulin; Insulin Secretion; Peptide Fragments; Peptides | 2001 |
Potentiation by methyl pyruvate of GLP-1 insulinotropic action in normal rats.
Methyl pyruvate (MP) stimulates insulin release both in vivo and in vitro. The present study aims at investigating whether MP is also able to enhance the B-cell secretory response to glucagon-like peptide 1 (GLP-1). In anaesthetized rats receiving a primed constant infusion of MP, the ester augmented plasma insulin concentration before GLP-1 injection and potentiated the insulinotropic action of the intestinal hormone. MP infusion also augmented plasma D-glucose concentration, whether in the absence or presence of GLP-1. A further rise in plasma D-glucose concentration was observed when the infusion of MP was halted, this coinciding with a fall in plasma insulin concentration. Whilst documenting that MP indeed enhances the B-cell secretory response to GLP-1, these findings do not suggest that MP is an appropriate tool for optimizing the hypoglycaemic action of the enteric hormone in the treatment of type-2 diabetes mellitus. Topics: Animals; B-Lymphocytes; Blood Glucose; Diabetes Mellitus, Type 2; Glucagon; Glucagon-Like Peptide 1; Glucose; Hypoglycemia; Insulin; Male; Peptide Fragments; Protein Precursors; Pyruvates; Rats; Rats, Wistar; Time Factors | 2001 |
Insulin resistance and type 2 diabetes: time for a new hypothesis.
Topics: Amyloid; Animals; Diabetes Mellitus, Type 2; Fatty Acids, Nonesterified; Gastric Inhibitory Polypeptide; Glucagon; Glucagon-Like Peptide 1; Humans; Insulin Resistance; Islet Amyloid Polypeptide; Leptin; Mice; Peptide Fragments; Protein Precursors; Tumor Necrosis Factor-alpha | 2001 |
Determinants of the impaired secretion of glucagon-like peptide-1 in type 2 diabetic patients.
To elucidate the causes of the diminished incretin effect in type 2 diabetes mellitus we investigated the secretion of the incretin hormones, glucagon-like peptide-1 and glucose- dependent insulinotropic polypeptide and measured nonesterified fatty acids, and plasma concentrations of insulin, C peptide, pancreatic polypeptide, and glucose during a 4-h mixed meal test in 54 heterogeneous type 2 diabetic patients, 33 matched control subjects with normal glucose tolerance, and 15 unmatched subjects with impaired glucose tolerance. The glucagon-like peptide-1 response in terms of area under the curve from 0-240 min after the start of the meal was significantly decreased in the patients (2482 +/- 145 compared with 3101 +/- 198 pmol/liter.240 min; P = 0.024). In addition, the area under the curve for glucose-dependent insulinotropic polypeptide was slightly decreased. In a multiple regression analysis, a model with diabetes, body mass index, male sex, insulin area under the curve (negative influence), glucose-dependent insulinotropic polypeptide area under the curve (negative influence), and glucagon area under the curve (positive influence) explained 42% of the variability of the glucagon-like peptide-1 response. The impaired glucose tolerance subjects were hyperinsulinemic and generally showed the same abnormalities as the diabetic patients, but to a lesser degree. We conclude that the meal-related glucagon-like peptide-1 response in type 2 diabetes is decreased, which may contribute to the decreased incretin effect in type 2 diabetes. Topics: Analysis of Variance; Autoantibodies; Blood Glucose; C-Peptide; Diabetes Mellitus, Type 2; Fasting; Fatty Acids, Nonesterified; Female; Gastric Inhibitory Polypeptide; Glucagon; Glucagon-Like Peptide 1; Glucose Intolerance; Glutamate Decarboxylase; Glycated Hemoglobin; Humans; Insulin; Male; Middle Aged; Pancreatic Polypeptide; Peptide Fragments; Peptides; Protein Precursors; Reference Values | 2001 |
Determinants of the effectiveness of glucagon-like peptide-1 in type 2 diabetes.
GLP-1 lowers blood glucose in fasting type 2 diabetic patients. To clarify the relation of the effect of GLP-1 to obesity, blood glucose, beta-cell function, and insulin sensitivity, GLP-1 (1.2 pmol/kg.min) was infused iv for 4-6 h into 50 fasting type 2 diabetic patients with a wide range of age, body mass index, HbA1c, and fasting plasma glucose. The effectiveness of GLP-1 was evaluated by calculation of a glucose disappearance constant for each individual (Kg, linear slope of log-transformed plasma glucose), and by the lowest stable glucose level (Nadir plasma glucose) obtained during the infusion. Grouped according to fasting plasma glucose (<10, 10-15, >15 mmol/liter), Kg values were 0.45 +/- 0.03, 0.38 +/- 0.04, and 0.28 +/- 0.04%/min (P = 0.005), and Nadir plasma glucose values were 4.7 +/- 0.1 (3.9-5.9), 5.8 +/- 0.4 (4.3-8.4), and 8.7 +/- 1.4 (6.2-18.7) mmol/liter (P = 0.0003). Nonresponders were not identified. Multiple regression analysis with Kg or Nadir plasma glucose as the dependent parameter and body mass index, age, gender, diabetes duration, and significantly correlated parameters (in multiple regression for Kg: fasting plasma glucose, fasting nonesterified fatty acid, dipeptidyl peptidase activity, peak insulin, and the logarithm of beta-cell function; and for Nadir plasma glucose: fasting plasma glucose, fasting nonesterified fatty acid, dipeptidyl peptidase activity, delta glucagon decrement, F-GLP-1 total, logarithm of beta-cell function, and Kg) as independent parameters resulted in fasting plasma glucose as the only significant predictor of Kg, and fasting plasma glucose and Kg as predictors of Nadir plasma glucose. Kg and Nadir plasma glucose were neither influenced by treatment nor by neuropathy per se. In conclusion, GLP-1 lowers plasma glucose in type 2 diabetes regardless of severity, but glucose elimination is faster and obtained glycemic level lower in patients with the lower fasting plasma glucose. Not all patients can be expected to reach normoglycemia. Topics: Area Under Curve; Autoantibodies; Blood Glucose; Body Mass Index; C-Peptide; Diabetes Mellitus, Type 2; Diabetic Neuropathies; Dipeptidyl Peptidase 4; Fasting; Fatty Acids, Nonesterified; Female; Glucagon; Glucagon-Like Peptide 1; Glutamate Decarboxylase; Glycated Hemoglobin; Humans; Infusions, Intravenous; Insulin; Islets of Langerhans; Isoenzymes; Male; Middle Aged; Peptide Fragments; Protein Precursors; Regression Analysis | 2001 |
Reduction of incretin-like salivatin in saliva from patients with type 2 diabetes and in parotid glands of streptozotocin-diabetic BALB/c mice.
Diabetic xerostomia is a typical syndrome in diabetic complication. We have reported that salivatin (salivary peptide P-C) derived from human saliva potentiates glucose-stimulated insulin release and inhibits arginine-stimulated glucagon release. The present study is aimed to gain further evidence on the physiological role by investigating the diabetic state-induced change in the amount of salivatin.. The amount of salivatin was measured in saliva taken from patients with type 2 diabetes with ELISA and with rabbit antiserum against human salivatin immunocytochemically in sections of parotid glands from streptozotocin-diabetic BALB/c mice.. The amount of salivatin after a meal was reduced by diabetes in both human saliva and in the serous secretory granule of mouse parotid gland acinar cells.. The above results suggest that salivatin lowers hyperglycaemia after meal and sustains the normal blood glucose levels by incretin-like mechanisms. The function may be damaged by diabetes, and this in turn might make the diabetes worse. Topics: Animals; Blood Glucose; Diabetes Mellitus, Experimental; Diabetes Mellitus, Type 2; Eating; Enzyme-Linked Immunosorbent Assay; Glucagon; Glucagon-Like Peptide 1; Glucagon-Like Peptides; Humans; Hypoglycemic Agents; Male; Mice; Mice, Inbred BALB C; Microscopy, Immunoelectron; Parotid Gland; Peptide Fragments; Peptides; Postprandial Period; Proline-Rich Protein Domains; Saliva; Salivary Proline-Rich Proteins | 2001 |
Urinary excretion of glucagon-like peptide 1 (GLP-1) 7-36 amide in human type 2 (non-insulin-dependent) diabetes mellitus.
The urinary excretion of insulinotropic glucagon-like peptide 1 (GLP-1) was investigated as an indicator of renal tubular integrity in 10 healthy subjects and in 3 groups of type 2 diabetic patients with different degrees of urinary albumin excretion rate. No significant difference emerged between the groups with respect to age of the patients, known duration of diabetes, metabolic control, BMI, or residual beta-cell pancreatic function. Endogenous creatinine clearance was significantly reduced under conditions of overt diabetic nephropathy, compared with normo and microalbuminuric patients (p < 0.01). Urinary excretion of GLP-1 was significantly higher in normoalbuminuric patients compared to controls (490.4 +/- 211.5 vs. 275.5 +/- 132.1 pg/min; p < 0.05), with further increase under incipient diabetic nephropathy conditions (648.6 +/- 305 pg/min; p < 0.01). No significant difference resulted, in contrast, between macroproteinuric patients and non-diabetic subjects. Taking all patients examined into account, a significant positive relationship emerged between urinary GLP-1 and creatinine clearance (p = 0.004). In conclusion, an early tubular impairment in type 2 diabetes would occur before the onset of glomerular permeability alterations. The tubular dysfunction seems to evolve with the development of persistent microalbuminuria. Finally, the advanced tubular involvement, in terms of urinary GLP1 excretion, under overt diabetic nephropathy conditions would be masked by severe concomitant glomerular damage with the coexistence of both alterations resulting in a peptide excretion similar to control subjects. Topics: Aged; Albuminuria; Body Mass Index; C-Peptide; Creatinine; Diabetes Mellitus, Type 2; Diabetic Nephropathies; Female; Glucagon; Glucagon-Like Peptide 1; Glucagon-Like Peptides; Glycated Hemoglobin; Humans; Male; Metabolic Clearance Rate; Middle Aged; Peptide Fragments | 2001 |
Insertion of an N-terminal 6-aminohexanoic acid after the 7 amino acid position of glucagon-like peptide-1 produces a long-acting hypoglycemic agent.
The use of glucagon-like peptide-1 (GLP-1) as a routine treatment for type 2 diabetes mellitus is undermined by its short biological half-life. A cause of degradation is its cleavage at the N-terminal HAE sequence by the enzyme dipeptidyl peptidase IV (DPP IV). To protect from DPP IV, we have studied the biological activity of a GLP-1 analog in which 6-aminohexanoic acid (Aha) is inserted between histidine and alanine at positions 7 and 8. We have compared the biological activity of this new compound, GLP-1 Aha(8), with the previously described GLP-1 8-glycine (GLP-1 Gly(8)) analog. GLP-1 Aha(8) (10 nM) was equipotent with GLP-1 (10 nM) in stimulating insulin secretion in RIN 1046-38 cells. As with GLP-1 Gly(8), the binding affinity of GLP-1 Aha(8) for the GLP-1 receptor in intact Chinese hamster ovary (CHO) cells expressing the human GLP-1 receptor (CHO/GLP-1R cells) was reduced (IC(50): GLP-1, 3.7 +/- 0.2 nM; GLP-1 Gly(8), 41 +/- 9 nM; GLP-1 Aha(8), 22 +/- 7 nM). GLP-1 Aha(8) was also shown to stimulate intracellular cAMP production 4-fold above basal at concentrations as low as 0.5 nM. However, it exhibited a higher ED(50) when compared to GLP-1 and GLP-1 Gly(8) (ED(50): GLP-1, 0.036 +/- 0.002 nM, GLP-1 Gly(8), 0.13 +/- 0.02 nM, GLP-1 Aha(8), 0.58 +/- 0.03 nM). A series of D-amino acid-substituted GLP-1 compounds were also examined to assess the importance of putative peptidase-sensitive cleavage sites present in the GLP-1 molecule. They had poor binding affinity for the GLP-1 receptor, and none of these compounds stimulated the production of intracellular cAMP in CHO/GLP-1R cells or insulin secretion in RIN 1046-38 cells. GLP-1 Aha(8) (24 nmol/kg) administered sc to fasted Zucker (fa/fa) rats (mean blood glucose, 195 +/- 32 mg/dl) lowered blood glucose levels to a nadir of 109 +/- 3 mg/dl, and it remained significantly lower for 8 h. Matrix-assisted linear desorption ionization-time of flight mass spectrometry of GLP-1 Aha(8) incubated with DPP IV (37 C, 2 h) did not exhibit an N-terminal degradation product. Taken together, these results show that insertion of Aha after the 7 position in GLP-1 produces an effective, long-acting GLP-1 analog, which may be useful in the treatment of type 2 diabetes mellitus. Topics: Amino Acid Sequence; Aminocaproic Acid; Animals; Cell Line; Diabetes Mellitus, Type 2; Glucagon; Glucagon-Like Peptide 1; Humans; Hypoglycemic Agents; Molecular Sequence Data; Mutagenesis, Insertional; Peptide Fragments; Protein Precursors; Rats; Structure-Activity Relationship | 2001 |
Effect of GLP-1 treatment on GLUT2 and GLUT4 expression in type 1 and type 2 rat diabetic models.
Glucagon-like peptide-1 (G LP-1) is an incretin with glucose-dependent insulinotropic and insulin-independent antidiabetic properties that exerts insulin-like effects on glucose metabolism in rat liver, skeletal muscle, and fat. This study aimed to search for the effect of a prolonged treatment, 3 ds, with GLP-1 on glucotransporter GLUT2 expression in liver, and on that of GLUT4 in skeletal muscle and fat, in rats. Normal rats and streptozotocin-induced type 1 and type 2 diabetic models were used; diabetic rats were also treated with insulin for comparison. In normal rats, GLP-1 treatment reduced in the three tissues the corresponding glucotransporter protein level, without modifying their mRNA. In the type 2 diabetic model, GLP-1, like insulin, stimulated in liver and fat only the glucotransporter translational process, while in the muscle an effect at the GLUT4 transcriptional level was also observed. In the type 1 diabetic model, GLP-1 apparently exerted in the liver only a posttranslational effect on GLUT2 expression; in muscle and fat, while insulin was shown to have an action on GLUT4 at both transcriptional and translational levels, the effect of GLP-1 was restricted to glucotransporter translation. In normal and diabetic rats, exogenous GLP-1 controlled the glucotransporter expression in extrapancreatic tissues participating in the overall glucose homeostasis-liver, muscle, and fat-where the effect of the peptide seems to be exerted only at the translational and/or posttranslational level; in muscle and fat, the presence of insulin seems to be required for GLP-1 to activate the transcriptional process. The stimulating action of GLP-1 on GLUT2 and GLUT4 expression, mRNA or protein, could be a mechanism by which, at least in part, the peptide exerts its lowering effect on blood glucose. Topics: Adipose Tissue; Animals; Blotting, Northern; Diabetes Mellitus, Experimental; Diabetes Mellitus, Type 1; Diabetes Mellitus, Type 2; Gene Expression; Glucagon; Glucagon-Like Peptide 1; Glucose; Glucose Transporter Type 2; Glucose Transporter Type 4; Liver; Male; Monosaccharide Transport Proteins; Muscle Proteins; Muscle, Skeletal; Peptide Fragments; Protein Precursors; Rats; Rats, Wistar; RNA, Messenger | 2001 |
GLP-1 effect upon the GPI/IPG system in adipocytes and hepatocytes from diabetic rats.
GLP-1 (glucagon-like peptide 1), proposed as a possible tool for Type 2 diabetes therapy, has insulin-like effects upon glucose metabolism in extrapancreatic tissues, whose plasma membranes contain specific receptors for the peptide, being those, at least in liver and muscle, not associated to the adenylate cyclase/cAMP system. GLP-1, as insulin, modulates the content of glycosylphosphatidylinositols (GPIs)--precursors of inositolphosphoglycans (IPGs), considered mediators of insulin action--in several extrapancreatic cell lines and in normal rat hepatocytes and adipocytes. In the present paper, we document that in a streptozotocin-induced Type 2 diabetic rat model, GLP-1, as insulin, provokes a rapid decrease of the [myo-3H-inositol]GPI content in isolated adipocytes--indicative of its hydrolysis and immediate short-lived generation of IPG--as that previously observed in normal animals; in hepatocytes, GLP-1, but not insulin, induced a reduction in the cellular GPI, although delayed in relation to normal rats. In adipocytes from streptozotocin-induced Type 1 diabetic rats, GLP-1, as insulin, seems to induce a reduction in the cellular GPI content, which was smaller and occurred later than that provoked in the Type 2 diabetic model; in the hepatocytes, GLP-1 and insulin failed to affect the control GPI content at any time tested. In Type 2 diabetic rat, the hepatocyte retains its response capability to GLP-1, but not to insulin, suggesting that the peptide could be bypassing possible defective steps in the insulin signaling pathway in the liver of this diabetic model. Topics: Adipocytes; Animals; Blood Glucose; Cells, Cultured; Diabetes Mellitus, Experimental; Diabetes Mellitus, Type 1; Diabetes Mellitus, Type 2; Disease Models, Animal; Glucagon; Glucagon-Like Peptide 1; Glycosylphosphatidylinositols; Hepatocytes; Hypoglycemic Agents; Inositol Phosphates; Insulin; Liver; Male; Oligosaccharides; Pancreas; Peptide Fragments; Polysaccharides; Protein Precursors; Rats; Rats, Wistar | 2001 |
Potentiation and prolongation of the insulinotropic action of glucagon-like peptide 1 by methyl pyruvate or dimethyl ester of L-glutamic acid in a type 2 diabetes animal model.
Methyl pyruvate and the dimethyl ester of L-glutamic acid were administered intravenously, as a primed constant infusion (1.0-2.0 micromol followed by 0.5-1.0 micromol/min, both expressed per gram of body wt), in adult rats that had been injected with streptozotocin during the neonatal period. Each ester augmented plasma insulin concentration and potentiated and/or prolonged the insulinotropic action of glucagon-like peptide 1 (GLP-1) injected intravenously (5 pmol/g of body wt) at min 5 of the test. It is proposed, therefore, that suitable nonglucidic nutrients, susceptible to bypassing the site-specific defects of D-glucose transport and metabolism responsible for the preferential impairment of the B-cell secretory response to D-glucose in non-insulin-dependent diabetes, could be used to optimize the insulinotropic action of GLP-1. Topics: Animals; Blood Glucose; Diabetes Mellitus, Experimental; Diabetes Mellitus, Type 2; Drug Synergism; Glucagon; Glucagon-Like Peptide 1; Glutamates; Injections, Intravenous; Insulin; Peptide Fragments; Protein Precursors; Pyruvates; Rats; Time Factors | 2001 |
Potent derivatives of glucagon-like peptide-1 with pharmacokinetic properties suitable for once daily administration.
A series of very potent derivatives of the 30-amino acid peptide hormone glucagon-like peptide-1 (GLP-1) is described. The compounds were all derivatized with fatty acids in order to protract their action by facilitating binding to serum albumin. GLP-1 had a potency (EC(50)) of 55 pM for the cloned human GLP-1 receptor. Many of the compounds had similar or even higher potencies, despite quite large substituents. All compounds derivatized with fatty acids equal to or longer than 12 carbon atoms were very protracted compared to GLP-1 and thus seem suitable for once daily administration to type 2 diabetic patients. A structure-activity relationship was obtained. GLP-1 could be derivatized with linear fatty acids up to the length of 16 carbon atoms, sometimes longer, almost anywhere in the C-terminal part without considerable loss of potency. Derivatization with two fatty acid substituents led to a considerable loss of potency. A structure-activity relationship on derivatization of specific amino acids generally was obtained. It was found that the longer the fatty acid, the more potency was lost. Simultaneous modification of the N-terminus (in order to obtain better metabolic stability) interfered with fatty acid derivatization and led to loss of potency. Topics: Acylation; Amino Acid Sequence; Animals; Cell Line; Chromatography, High Pressure Liquid; Cricetinae; Diabetes Mellitus, Type 2; Fatty Acids; Glucagon; Glucagon-Like Peptide 1; Kidney; Lysine; Molecular Sequence Data; Peptide Fragments; Peptides; Protein Precursors; Spectrophotometry, Ultraviolet; Structure-Activity Relationship; Swine | 2000 |
Lack of germline mutations in the preproglucagon gene region coding for glucagon-like peptide 1 in Type 2 diabetic (NIDDM) patients.
Glucagon-like peptide 1 (GLP-1) has antidiabetic effects and many facets of Type 2 diabetes could theoretically be the consequence of a reduction in or lack of GLP-1 function. Exogenous GLP-1 is exquisitely effective in Type 2 diabetic patients, making receptor defects unlikely. GLP-1 responses after meals as detected by radioimmunoassay are not overtly reduced in Type 2 diabetic patients. Therefore, a sequence analysis of exon 2 of the preproglucagon gene coding for the GLP-1 protein was initiated in order to exclude potential germline mutations. 24 Type 2 diabetic patients and in 14 control subjects with normal oral glucose tolerance (WHO criteria) were studied. In all specimens of peripheral blood leukocyte DNA examined, no germline mutations of the GLP-1 sequence were identified, thus excluding mutations in the GLP-1 sequence as a major contributor to the pathophysiological appearance of the Type 2 diabetic phenotype. Rare mutations, however, cannot be excluded due to the small number of Type 2 diabetic patients examined. Topics: Aged; Amino Acid Sequence; Base Sequence; Diabetes Mellitus, Type 2; Female; Glucagon; Glucagon-Like Peptide 1; Humans; Insulin; Insulin Secretion; Male; Middle Aged; Molecular Sequence Data; Mutation; Peptide Fragments; Proglucagon; Protein Precursors; Sequence Analysis, DNA | 2000 |
Evaluation of beta-cell secretory capacity using glucagon-like peptide 1.
Beta-cell secretory capacity is often evaluated with a glucagon test or a meal test. However, glucagon-like peptide 1 (GLP-1) is the most insulinotropic hormone known, and the effect is preserved in type 2 diabetic patients.. We first compared the effects of intravenous bolus injections of 2.5, 5, 15, and 25 nmol GLP-1 with glucagon (1 mg intravenous) and a standard meal (566 kcal) in 6 type 2 diabetic patients and 6 matched control subjects. Next, we studied another 6 patients and 6 control subjects and, in addition to the above procedure, performed a combined glucose plus GLP-1 stimulation, where plasma glucose was increased to 15 mmol/l before injection of 2.5 nmol GLP-1. Finally, we compared the insulin response to glucose plus GLP-1 stimulation with that observed during a hyperglycemic arginine clamp (30 mmol/l) in 8 patients and 8 control subjects.. Peak insulin and C-peptide concentrations were similar after the meal, after 2.5 nmol GLP-1, and after glucagon. Side effects were less with GLP-1 than with glucagon. Peak insulin and C-peptide concentrations were as follows (C-peptide concentrations are given in parentheses): for patients (n = 12): meal, 277 +/- 42 pmol/l (2,181 +/- 261 pmol/l); GLP-1 (2.5 nmol), 390 +/- 74 pmol/l (2,144 +/- 254 pmol/l); glucagon, 329 +/- 50 pmol/l (1,780 +/- 160 pmol/l); glucose plus GLP-1, 465 +/- 87 pmol/l (2,384 +/- 299 pmol/l); for control subjects (n = 12): meal, 543 +/- 89 pmol/l (2,873 +/- 210 pmol/l); GLP-1, 356 +/- 51 pmol/l (2,001 +/- 130 pmol/l); glucagon, 420 +/- 61 pmol/l (1,995 +/- 99 pmol/l); glucose plus GLP-1, 1,412 +/- 187 pmol/l (4,391 +/- 416 pmol/l). Peak insulin and C-peptide concentrations during the hyperglycemic arginine clamp and during glucose plus GLP-1 injection were as follows: for patients: 475 +/- 141 pmol/l (2,295 +/- 379 pmol/l) and 816 +/- 268 pmol/l (3,043 +/- 508 pmol/l), respectively; for control subjects: 1,403 +/- 308 pmol/l (4,053 +/- 533 pmol/l) and 2,384 +/- 452 pmol/l (6,047 +/- 652 pmol/l), respectively.. GLP-1 (2.5 nmol = 9 microg) elicits similar secretory responses to 1 mg glucagon (but has fewer side effects) and a standard meal. Additional elevation of plasma glucose to 15 mmol/l did not enhance the response further. The incremental response was similar to that elicited by arginine, but hyperglycemia had an additional effect on the response to arginine. Topics: Aged; Blood Glucose; C-Peptide; Diabetes Mellitus, Type 2; Female; Glucagon; Glucagon-Like Peptide 1; Humans; Injections, Intravenous; Insulin; Insulin Secretion; Islets of Langerhans; Male; Middle Aged; Peptide Fragments; Postprandial Period; Protein Precursors; Reference Values; Time Factors | 2000 |
Prolongation of the insulinotropic action of glucagon-like peptide 1 by the dimethyl ester of succinic acid in an animal model of type-2 diabetes.
Adult rats, that had been injected with streptozotocin during the neonatal period, received a primed constant infusion of succinic acid dimethyl ester (SAD; 0.5 micromol followed by 0.25 micromol x min(-1), both per g body wt.) in saline for 15 min and, at the 5th min of such an infusion, an intravenous injection of GLP-1 (5 pmol per g body wt.). Within 2 min, the ester increased the plasma insulin concentration by 0.33+/-0.05 nM. Likewise, within 2 min, GLP-1 provoked a marked increase in plasma insulin concentration; such an increase was comparable in rats infused with either saline or SAD, with an overall mean value of 0.93+/-0.07 nM. In the rats infused with SAD, however, the secretory response to GLP-1 appeared more sustained than in the saline-infused animals. For instance, the paired ratio for the insulinogenic index at 10/2 min after GLP-1 injection averaged 30.5+/-4.0% in SAD-infused rats, as compared (P<0.025) to only 17.0+/-2.5% in saline-infused animals. These findings suggest that succinic acid esters could be used to prolong the insulinotropic action of GLP-1 in the treatment of type-2 diabetes. Topics: Animals; Diabetes Mellitus, Experimental; Diabetes Mellitus, Type 2; Glucagon; Glucagon-Like Peptide 1; Insulin; Male; Pancreas; Peptide Fragments; Protein Precursors; Rats; Succinates | 2000 |
Oral delivery of glucagon-like peptide-1 in a modified polymer preparation normalizes basal glycaemia in diabetic db/db mice.
The insulinotropic hormone, glucagon-like peptide-1 has been proposed for the treatment of patients with Type II (non-insulin-dependent) diabetes mellitus. As glucagon-like peptide-1 is rapidly cleaved at L-ala2 by dipeptidylpeptidase IV, D-ala2-glucagon-like peptide-1 was synthesized and shown to have dipeptidylpeptidase IV resistance in vitro and enhanced bioactivity in mice during an oral glucose challenge. The actions of D-ala2-glucagon-like peptide-1 were, however, lost within 4 h of injection, thus necessitating frequent and invasive treatment if it is to be used therapeutically. To circumvent this problem, a microsphere of D-ala2-glucagon-like peptide-1 that could be given orally was developed.. We encapsulated D-ala2-glucagon-like peptide-1 in poly(lactide-co-glycolide)-COOH with olive oil as a filler, using phase inversion. The microspheres were tested in vivo by oral gavage in mice at t = 0 h followed by repeated oral glucose tolerance tests at t = 0, 4 and 8 h.. The D-ala2-glucagon-like peptide-1-microspheres lowered the glycaemic response to the 4 h oral glucose challenge in both normal CD1 and diabetic db/db mice, by 41 +/- 12% (p <0.001) and 27 +/- 5% (p < 0.001), respectively and by 19 +/- 11% (p < 0.05) and 28 +/- 4% (p < 0.001), respectively during the 8-h test. At 4 h after the oral gavage, basal glycaemia in the diabetic mice was reduced from 13 +/- 1 mmol/l to 10 +/- 1 mmol/l and was reduced further 8h after treatment from 12 +/- 1 mmol/l to 8 +/- 1 mmol/l (p < 0.05). Giving D-ala2-glucagon-like peptide-1 alone orally had no effect on glycaemia.. The data presented here suggest that a similar microsphere preparation could be useful in the delivery of glucagon-like peptide-1 to patients with Type II diabetes. Topics: 3-O-Methylglucose; Administration, Oral; Animals; Blood Glucose; Diabetes Mellitus; Diabetes Mellitus, Type 2; Drug Carriers; Female; Glucagon; Glucagon-Like Peptide 1; Glucose Tolerance Test; Humans; Kinetics; Mice; Microspheres; Olive Oil; Peptide Fragments; Plant Oils; Polymers; Protein Precursors | 2000 |
Glucagon-like peptide (GLP)-1 and leptin concentrations in obese patients with Type 2 diabetes mellitus.
To assess differences in circulating leptin and glucagon-like peptide (GLP)-1 concentrations before and after an oral glucose load, in euglycaemic and isoinsulinaemic conditions, between obese patients with and without Type 2 diabetes mellitus.. Ten male obese (body mass index (BMI) > 30 kg/m2) patients with Type 2 diabetes and 20 matched non-diabetic subjects were studied. Leptin, GLP-1(7-36)amide and GLP-1(7-37) concentrations were measured 0, 30, 60, and 90 min after a 50-g oral glucose load administered 90 min after the beginning of a euglycaemic hyperinsulinaemic clamp.. GLP-1(7-36)amide concentrations before the glucose load were significantly lower in diabetic patients than in controls (median (quartiles): 50.5 (44.7-53.2) vs. 128.7(100-172.5) pg/ml; P < 0.01), while no difference was observed in baseline GLP-1(7-37). In non-diabetic subjects, GLP-1(7-36)amide and GLP-1(7-37) concentrations increased significantly after the oral glucose load, while no glucose-induced increase in GLP-1 concentration was observed in diabetic patients. GLP-1(7-36)amide at 30, 60, and 90 min, and GLP-1(7-37) at 30 min, of the glucose challenge, were significantly lower in diabetic patients. Leptin concentrations were not significantly different in diabetic patients when compared to non-diabetic subjects, and they did not change after the oral glucose load.. Leptin concentrations are not significantly modified in obese Type 2 diabetic patients. GLP-1(7-36)amide baseline concentrations are reduced in Type 2 diabetes; moreover, diabetic subjects show an impaired response of GLP-1 to oral glucose in euglycaemic, isoinsulinaemic conditions. This impairment, which is not the result of differences in glycaemia or insulinaemia during assessment, could contribute to the pathogenesis of hyperglycaemia in Type 2 diabetes mellitus. Topics: Blood Glucose; Diabetes Mellitus; Diabetes Mellitus, Type 2; Glucagon; Glucagon-Like Peptide 1; Glucose Clamp Technique; Glucose Tolerance Test; Glycated Hemoglobin; Humans; Hyperinsulinism; Insulin; Leptin; Male; Middle Aged; Obesity; Peptide Fragments; Protein Precursors | 2000 |
Impaired neural regulation of insulin secretion related to the leptin receptor gene mutation in Wistar fatty rats.
The Wistar fatty (WF) rat is a model of obese Type 2 diabetes mellitus (DM). These rats were bred by crossing Zucker fatty (ZF) and Wistar-Kyoto (WKY) rats. A homo-allelic leptin receptor gene mutation has been reported in ZF rats. We report here how these genetic factors contribute to plasma insulin regulation. The fasting plasma insulin levels were higher in WKY and Wistar lean (WL) rats than in Zucker lean (ZL) rats (p<0.05). The levels in WF and ZF rats were higher than in their respective lean littermates, WL and ZL rats (p<0.05). After intragastric glucose load, the plasma insulin increase was reduced upon pretreatment by intracerebroventricular (i. c.v.) methylatropine (an antagonist of the cholinergic receptor) injection in WL rats (p<0.05) but not in WF rats. Plasma glucagon-like peptide-1 (GLP-1) response to intragastric glucose load was not affected by methylatropine. After selective hepatic-vagotomy, plasma insulin levels increased in wild-type ZL rats (p<0.05). This increase was not observed in heterozygote ZL rats. Surprisingly, this response of plasma insulin was not shown in wild-type WL and WKY rats. ZF and WF rats did show a prominent decrease in insulin response (p<0.05). These results indicate that the genetic factor in ZF rats is associated with impaired vagal nerve-mediated control of insulin secretion. The genetic factor in WKY rats may diminish sensitivity to the vagal information of insulin release and contribute to insulin resistance. Therefore, we conclude that the presence of both genetic factors in a homo-allelic state is important to the development of DM in WF rats. Topics: Animals; Atropine Derivatives; Blood Glucose; Carrier Proteins; Crosses, Genetic; Diabetes Mellitus; Diabetes Mellitus, Experimental; Diabetes Mellitus, Type 2; Disease Models, Animal; Glucagon; Glucagon-Like Peptide 1; Glucose Tolerance Test; Injections, Intraventricular; Insulin; Insulin Resistance; Insulin Secretion; Mutation; Obesity; Peptide Fragments; Protein Precursors; Rats; Rats, Inbred WKY; Rats, Zucker; Receptors, Cell Surface; Receptors, Leptin; Vagotomy; Vagus Nerve | 2000 |
Glucagon-like peptide-1 stimulates insulin secretion by a Ca2+-independent mechanism in Zucker diabetic fatty rat islets of Langerhans.
This study investigates the mechanisms responsible for glucagon-like peptide-1 (GLP-1)-induced insulin secretion in Zucker diabetic fatty (ZDF) rats and their lean control (ZLC) littermates. Glucose, and 100 nmol/L GLP-1 (7-37 hydroxide) in the presence of stimulatory glucose concentrations, induced insulin secretion in islets from ZLC animals. In contrast, ZDF islets hypersecreted insulin at low glucose (5 mmol/L) and were poorly responsive to 15 mmol/L glucose stimulation, but increased insulin secretion following exposure to GLP-1. The insulin secretory response to 100 nmol/L GLP-1 was reduced by 88% in ZLC islets exposed to exendin 9-39. The intracellular Ca2+ concentration ([Ca2+]i) increased in fura-2-loaded ZLC islets following stimulation with 12 mmol/L glucose alone or GLP-1 in the presence of 12 mmol/L glucose. The increases in [Ca2+]i and insulin secretion in ZLC islets induced by GLP-1 were attenuated by 1 micromol/L nitrendipine. In contrast, neither glucose nor GLP-1 substantially increased [Ca2+]i in ZDF islets. Furthermore, insulin secretory responses to GLP-1 were not significantly inhibited in ZDF islets by nitrendipine. However, the insulin secretory response to GLP-1 in both ZLC and ZDF islets was ablated by cholera toxin. Our findings indicate that in ZLC islets, GLP-1 induces insulin secretion by a mechanism that depends on Ca2+ influx through voltage-dependent Ca2+ channels, whereas in ZDF islets, the action of GLP-1 is mediated by Ca2+-independent signaling pathways. Topics: Animals; Calcium; Diabetes Mellitus; Diabetes Mellitus, Type 2; Glucagon; Glucagon-Like Peptide 1; Insulin; Insulin Secretion; Islets of Langerhans; Obesity; Peptide Fragments; Protein Precursors; Rats; Rats, Zucker | 2000 |
Cytosolic calcium handling in islets of normal Wistar and diabetic Goto Kakizaki rats in the presence of glucose and truncated glucagon-like peptide 1 (7-36) amide.
Topics: Animals; Calcium; Cytosol; Diabetes Mellitus, Type 2; Glucagon; Glucagon-Like Peptide 1; Glucagon-Like Peptides; Glucose; In Vitro Techniques; Insulin; Insulin Secretion; Islets of Langerhans; Peptide Fragments; Rats; Rats, Wistar | 2000 |
Insulinotropin PACAP potentiates insulin action. Stimulation of glucose uptake in 3T3-LI adipocytes.
PAC1 receptor was expressed in the rat fat tissue and 3T3-L1 adipocytes. PACAP-38 (10 nM) significantly enhanced insulin induced 2-deoxyglucose uptake by 3T3-L1 adipocytes. GLP-1 has a similar effect. PACAP-38 further increased insulin stimulated phosphatidylinositol (PI) 3-kinase activity, but has not effect on tyrosine phosphorylation of insulin receptor beta-subunit or IRS-1. These results reveal that PACAP-38 enhances insulin induced glucose uptake, an effect probably mediated by PI 3-kinase. In conclusion, PACAP potentiates not only insulin secretion but also insulin action in adipocytes, thereby exhibiting antidiabetic actions at two important steps of glucose metabolism (Fig. 2). Topics: 3T3 Cells; Adipocytes; Animals; Biological Transport, Active; Deoxyglucose; Diabetes Mellitus, Type 2; Drug Synergism; Glucagon; Glucagon-Like Peptide 1; Glucose; Insulin; Mice; Models, Biological; Neuropeptides; Peptide Fragments; Pituitary Adenylate Cyclase-Activating Polypeptide; Protein Precursors; Receptors, Pituitary Adenylate Cyclase-Activating Polypeptide; Receptors, Pituitary Adenylate Cyclase-Activating Polypeptide, Type I; Receptors, Pituitary Hormone | 2000 |
Once daily injection of exendin-4 to diabetic mice achieves long-term beneficial effects on blood glucose concentrations.
Glucagon-like peptide-1 is the main hormonal mediator of the enteroinsular axis. Recently, it has additionally received considerable attention as a possible new treatment for Type II (non-insulin-dependent) diabetes mellitus. Its major disadvantage is that its duration of action is too short to achieve good 24-h metabolic control. Exendin-4, which is produced in the salivary glands of Gila monster lizards, is structurally similar to glucagon-like peptide-1 and shares several useful biological properties with glucagon-like peptide-1. It binds the glucagon-like peptide-1 receptor, stimulates insulin release and increases the cAMP production in beta cells. We report that exendin-4 is a more potent insulinotropic agent when given intravenously to rats than is glucagon-like peptide-1 (ED50 0.19 nmol/kg for glucagon-like peptide-1 vs 0.0143 nmol/kg for exendin-4) and causes a greater elevation in cAMP concentrations in isolated islets. Of even greater interest we found that when given intraperitoneally only once daily to diabetic mice it had a prolonged effect of lowering blood glucose. After 1 week of treatment blood glucoses were 5.0+/-2.6 mmol/l compared to diabetic concentrations of 13.2+/-2.8 mmol/l. After 13 weeks of daily treatment HbA1c was 8.8+/-0.4% in non-treated diabetic animals compared with 4.7+/-0.25% in treated diabetic animals. Blood glucoses also were lower (p < 0.005) and insulin concentrations higher (p < 0.02) in the treated animals. Exendin-4 could therefore be preferable to glucagon-like peptide-1 as a long-term treatment of Type II diabetes. Topics: Animals; Blood Glucose; Body Weight; Carrier Proteins; Crosses, Genetic; Cyclic AMP; Diabetes Mellitus, Type 2; Drug Administration Schedule; Energy Intake; Exenatide; Glucagon; Glucagon-Like Peptide 1; Glycated Hemoglobin; Insulin; Islets of Langerhans; Lizards; Mice; Mice, Inbred C57BL; Peptide Fragments; Peptides; Protein Precursors; Rats; Rats, Wistar; Receptors, Cell Surface; Receptors, Leptin; Venoms | 1999 |
Euglycaemic hyperinsulinaemia does not affect gastric emptying in type I and type II diabetes mellitus.
Hyperglycaemia slows gastric emptying in both normal subjects and patients with diabetes mellitus. The mechanisms mediating this effect, particularly the potential role of insulin, are uncertain. Hyperinsulinaemia has been reported to slow gastric emptying in normal subjects during euglycaemia. The purpose of this study was to evaluate the effect of euglycaemic hyperinsulinaemia on gastric emptying in Type I (insulin-dependent) and Type II (noninsulin-dependent) diabetes mellitus. In six patients with uncomplicated Type I and eight patients with uncomplicated Type II diabetes mellitus, measurements of gastric emptying were done on 2 separate days. No patients had gastrointestinal symptoms or cardiovascular autonomic neuropathy. The insulin infusion rate was 40 mU x m(-2) x min(-1) on one day and 80 mU x m(-2) x min(-1) on the other. Gastric emptying and intragastric meal distribution were measured using a scintigraphic technique for 3 h after ingestion of a mixed solid/liquid meal and results compared with a range established in normal volunteers. In both Type I and Type II patients the serum insulin concentration had no effect on gastric emptying or intragastric meal distribution of solids or liquids. When gastric emptying during insulin infusion rates of 40 mU x m(-2) x min(-1) and 80 mU x m(-2) x min(-1) were compared the solid T50 was 137.8+/-24.6 min vs. 128.7+/-24.3 min and liquid T50 was 36.7+/-19.4 min vs. 40.4+/-15.7 min in the Type I patients; the solid T50 was 94.9+/-19.1 vs. 86.1+/-10.7 min and liquid T50 was 21.8+/-6.9 min vs. 21.8+/-5.9 min in the Type II patients. We conclude that hyperinsulinaemia during euglycaemia has no notable effect on gastric emptying in patients with uncomplicated Type I and Type II diabetes; any effect of insulin on gastric emptying in patients with diabetes is likely to be minimal. Topics: Adult; Amyloid; Blood Glucose; C-Peptide; Cholecystokinin; Diabetes Mellitus, Type 1; Diabetes Mellitus, Type 2; Female; Gastric Emptying; Glucagon; Glucagon-Like Peptide 1; Glucose Clamp Technique; Glycated Hemoglobin; Humans; Hyperinsulinism; Hypoglycemic Agents; Infusions, Intravenous; Insulin; Islet Amyloid Polypeptide; Male; Peptide Fragments; Protein Precursors | 1999 |
Glucagon-like peptide 1 increases insulin sensitivity in depancreatized dogs.
To determine whether glucagon-like peptide (GLP)-1 increases insulin sensitivity in addition to stimulating insulin secretion, we studied totally depancreatized dogs to eliminate GLP-1's incretin effect. Somatostatin was infused (0.8 microg x kg(-1) x min(-1)) to inhibit extrapancreatic glucagon in dogs, and basal glucagon was restored by intraportal infusion (0.65 ng x kg(-1) x min(-1)). To simulate the residual intraportal insulin secretion in type 2 diabetes, basal intraportal insulin infusion was given to obtain plasma glucose concentrations of approximately 10 mmol/l. Glucose was clamped at this level for the remainder of the experiment, which included peripheral insulin infusion (high dose, 5.4 pmol x kg(-1) x min(-1), or low dose, 0.75 pmol x kg(-1) x min(-1)) with or without GLP-1(7-36) amide (1.5 pmol x kg(-1) x min(-1)). Glucose production and utilization were measured with 3-[3H]glucose, using radiolabeled glucose infusates. In 12 paired experiments with six dogs at the high insulin dose, GLP-1 infusion resulted in higher glucose requirements than saline (60.9+/-11.0 vs. 43.6+/-8.3 micromol x kg(-1) x min(-1), P< 0.001), because of greater glucose utilization (72.6+/-11.0 vs. 56.8+/-9.7 micromol x kg(-1) x min(-1), P<0.001), whereas the suppression of glucose production was not affected by GLP-1. Free fatty acids (FFAs) were significantly lower with GLP-1 than saline (375.3+/-103.0 vs. 524.4+/-101.1 micromol/l, P<0.01), as was glycerol (77.9+/-17.5 vs. 125.6+/-51.8 micromol/l, P<0.05). GLP-1 receptor gene expression was found using reverse transcriptase-polymerase chain reaction of poly(A)-selected RNA in muscle and adipose tissue, but not in liver. Low levels of GLP-1 receptor gene expression were also found in adipose tissue using Northern blotting. In 10 paired experiments with five dogs at the low insulin dose, GLP-1 infusion did not affect glucose utilization or FFA and glycerol suppression when compared with saline, suggesting that GLP-1's effect on insulin action was dependent on the insulin dose. In conclusion, in depancreatized dogs, GLP-1 potentiates insulin-stimulated glucose utilization, an effect that might be contributed in part by GLP-1 potentiation of insulin's antilipolytic action. Topics: Adipose Tissue; Animals; Blood Glucose; Diabetes Mellitus, Experimental; Diabetes Mellitus, Type 2; Dogs; Fatty Acids, Nonesterified; Female; Gene Expression; Glucagon; Glucagon-Like Peptide 1; Glucagon-Like Peptide-1 Receptor; Glucose Clamp Technique; Glycerol; Insulin; Insulin Secretion; Kinetics; Male; Pancreatectomy; Peptide Fragments; Protein Precursors; Receptors, Glucagon; Reverse Transcriptase Polymerase Chain Reaction; Somatostatin | 1999 |
Properties of native and in vitro glycosylated forms of the glucagon-like peptide-1 receptor antagonist exendin(9-39).
The intestinal hormone glucagon-like peptide-1-(7-36)-amide (GLP-1) has recently been implicated as a possible therapeutic agent for the management of type 2 non-insulin-dependent diabetes mellitus (NIDDM). However, a major difficulty with the delivery of peptide-based agents is their short plasma half-life, mainly due to rapid serum clearance and proteolytic degradation. Using a peptide analog of GLP-1, the GLP-1 receptor antagonist exendin(9-39), we investigated whether the conjugation of a carbohydrate structure to exendin(9-39) would generate a peptide with intact biological activity and improved survival in circulation. The C-terminal portion of exendin(9-39) was reengineered to generate an efficient site for enzymatic O-glycosylation. The modified exendin(9-39) peptide (exe-M) was glycosylated by recombinant UDP-GalNAc:polypeptide N-acetylgalactosaminyltransferase 1 (GalNAc-T1) alone or in conjunction with a recombinant GalNAc alpha2,6-sialyltransferase (Sialyl-T), resulting in exe-M peptides containing either the monosaccharide GalNAc or the disaccharide NeuAc alpha2,6GalNAc. The nonglycosylated and glycosylated forms of exe-M competed with nearly equal potency (> 90% of control) with the binding of [125I]GLP-1 to human GLP-1 receptors expressed on stably transfected COS-7 cells. In addition, each peptide was equally effective for inhibiting GLP-1-induced cyclic adenosine monophosphate (cAMP) production in vitro. Studies with rats demonstrated that the modified and glycosylated forms of exendin(9-39) could antagonize exogenously administered GLP-1 in vivo. Interestingly, glycosylated exendin(9-39) homologs were more than twice as effective as the nonglycosylated peptide for inhibiting GLP-1-stimulated insulin production in vivo, suggesting a longer functional half-life in the circulation for glycosylated peptides. Results from in vivo studies with 3H-labeled peptides suggest that the glycosylated peptides may be less susceptible to modification in the circulation. Topics: Animals; Chlorocebus aethiops; Cyclic AMP; Diabetes Mellitus, Type 2; Glucagon; Glucagon-Like Peptide 1; Glycosylation; Humans; In Vitro Techniques; Male; Peptide Fragments; Protein Precursors; Rats; Rats, Sprague-Dawley | 1999 |
The European Association for the Study of Diabetes Annual Meeting, 1998. Treatment of type 2 diabetes and the pathogenesis of complications.
Topics: Diabetes Mellitus; Diabetes Mellitus, Type 2; Glucagon; Glucagon-Like Peptide 1; Humans; Hypoglycemic Agents; Insulin Resistance; Obesity; Peptide Fragments; Protein Precursors | 1999 |
[Inhibition of incretin degradation--a new therapy principle for treatment of type 2 diabetes?].
Topics: Administration, Oral; Animals; Blood Glucose; Diabetes Mellitus, Experimental; Diabetes Mellitus, Type 2; Dipeptidyl Peptidase 4; Enzyme Inhibitors; Glucagon; Glucagon-Like Peptide 1; Glucagon-Like Peptides; Humans; Hypoglycemic Agents; Isoleucine; Peptide Fragments; Rats; Rats, Zucker; Thiazoles | 1999 |
Twenty-four-hour insulin secretion rates, circulating concentrations of fuel substrates and gut incretin hormones in healthy offspring of Type II (non-insulin-dependent) diabetic parents: evidence of several aberrations.
Insulin resistance is a common feature in relatives of patients with Type II (non-insulin-dependent) diabetes mellitus and abnormalities in beta-cell function can also exist. Insight into non-fasting carbohydrate metabolism in these potentially prediabetic subjects relies almost exclusively on studies in which glucose is infused or ingested or both. We aimed to characterize insulin secretion and aspects of hormonal and metabolic patterns in relatives using a physiological approach.. We examined profiles of insulin, C peptide, proinsulin, gut incretin hormones and fuel substrates in 26 glucose tolerant but insulin resistant (clamp) relatives and 17 control subjects during a 24-hour period including three meals.. During the day plasma glucose was slightly raised in relatives (p < 0.05). Overall insulin secretion calculated on the basis of C peptide kinetics were increased in relatives (p < 0.0005) whereas incremental insulin secretion after all three meals were similar. Peak incremental insulin secretion tended, however, to be reduced in relatives (p < 0.10). Despite considerably increased insulin concentrations in relatives (70 %, p < 0.001), serum NEFA did not differ. Postprandial proinsulin concentrations (p < 0.05), but not proinsulin:insulin ratios, were increased in relatives. After meals concentrations of glucose-dependent-insulinotropic polypeptide (p < 0.05) were increased in relatives. Glucagon-like peptide-1 concentrations were similar.. Several hormonal and metabolic aberrations are present in healthy relatives of Type II diabetic patients during conditions that simulate daily living. Increased concentrations of glucose-dependent-insulinotropic polypeptide could indicate a beta-cell receptor defect for glucose-dependent-insulinotropic polypeptide in the prediabetic stage of Type II diabetes. Incremental insulin secretion after mixed meals appear normal in relatives, although a trend towards diminished peak values possibly signifies early beta-cell dysfunction. [Diabetologia (1999) 42: 1314-1323] Topics: Adult; Blood; Blood Glucose; C-Peptide; Circadian Rhythm; Diabetes Mellitus, Type 2; Eating; Energy Metabolism; Fatty Acids, Nonesterified; Female; Glucagon; Glucagon-Like Peptide 1; Glucagon-Like Peptides; Glucose Tolerance Test; Humans; Insulin; Insulin Secretion; Intestinal Mucosa; Male; Middle Aged; Peptide Fragments; Proinsulin; Reference Values | 1999 |
Exendin-4 stimulates both beta-cell replication and neogenesis, resulting in increased beta-cell mass and improved glucose tolerance in diabetic rats.
Diabetes is a disease of increasing prevalence in the general population and of unknown cause. Diabetes is manifested as hyperglycemia due to a relative deficiency of the production of insulin by the pancreatic beta-cells. One determinant in the development of diabetes is an inadequate mass of beta-cells, either absolute (type 1, juvenile diabetes) or relative (type 2, maturity-onset diabetes). Earlier, we reported that the intestinal hormone glucagon-like peptide I (GLP-I) effectively augments glucose-stimulated insulin secretion. Here we report that exendin-4, a long-acting GLP-I agonist, stimulates both the differentiation of beta-cells from ductal progenitor cells (neogenesis) and proliferation of beta-cells when administered to rats. In a partial pancreatectomy rat model of type 2 diabetes, the daily administration of exendin-4 for 10 days post-pancreatectomy attenuates the development of diabetes. We show that exendin-4 stimulates the regeneration of the pancreas and expansion of beta-cell mass by processes of both neogenesis and proliferation of beta-cells. Thus, GLP-I and analogs thereof hold promise as a novel therapy to stimulate beta-cell growth and differentiation when administered to diabetic individuals with reduced beta-cell mass. Topics: Animals; Blood Glucose; Cell Division; Diabetes Mellitus, Experimental; Diabetes Mellitus, Type 2; Exenatide; Gene Expression Regulation; Glucagon; Glucagon-Like Peptide 1; Glucagon-Like Peptide-1 Receptor; Insulin; Islets of Langerhans; Male; Pancreatectomy; Peptide Fragments; Peptides; Protein Precursors; Rats; Rats, Sprague-Dawley; Receptors, Glucagon; Venoms | 1999 |
Glucose intolerance caused by a defect in the entero-insular axis: a study in gastric inhibitory polypeptide receptor knockout mice.
Mice with a targeted mutation of the gastric inhibitory polypeptide (GIP) receptor gene (GIPR) were generated to determine the role of GIP as a mediator of signals from the gut to pancreatic beta cells. GIPR-/- mice have higher blood glucose levels with impaired initial insulin response after oral glucose load. Although blood glucose levels after meal ingestion are not increased by high-fat diet in GIPR+/+ mice because of compensatory higher insulin secretion, they are significantly increased in GIPR-/- mice because of the lack of such enhancement. Accordingly, early insulin secretion mediated by GIP determines glucose tolerance after oral glucose load in vivo, and because GIP plays an important role in the compensatory enhancement of insulin secretion produced by a high insulin demand, a defect in this entero-insular axis may contribute to the pathogenesis of diabetes. Topics: Administration, Oral; Animals; Diabetes Mellitus, Type 2; Dietary Fats; Gastric Inhibitory Polypeptide; Glucagon; Glucagon-Like Peptide 1; Glucagon-Like Peptides; Glucose; Glucose Intolerance; Glucose Tolerance Test; Homeostasis; Injections, Intraperitoneal; Insulin; Insulin Resistance; Insulin Secretion; Intestines; Islets of Langerhans; Mice; Mice, Knockout; Models, Biological; Peptide Fragments; Protein Precursors; Receptors, Gastrointestinal Hormone | 1999 |
Glucagon-like peptide 1 improves the ability of the beta-cell to sense and respond to glucose in subjects with impaired glucose tolerance.
Impaired glucose tolerance (IGT) and NIDDM are both associated with an impaired ability of the beta-cell to sense and respond to small changes in plasma glucose concentrations. The aim of this study was to establish if glucagon-like peptide 1 (GLP-1), a natural enteric peptide and potent insulin secretagogue, improves this defect. Two weight-matched groups, one with eight subjects having IGT (2-h glucose, 10.1 +/- 0.3 mmol/l) and another with seven subjects with diet-treated NIDDM (2-h glucose, 14.5 +/- 0.9 mmol/l), were studied on two occasions during a 12-h oscillatory glucose infusion, a sensitive test of the ability of the beta-cell to sense and respond to glucose. Glucose was infused with a mean rate of 4 mg x kg(-1) x min(-1), amplitude 33% above and below the mean rate, and periodicity of 144 min, with infusion of saline or GLP-1 at 0.4 pmol x kg(-1) x min(-1) for 12 h. Mean glucose levels were significantly lower in both groups during the GLP-1 infusion compared with during saline infusion: 9.2 +/- 0.4 vs. 6.4 +/- 0.1 mmol/l in the IGT subjects (P < 0.0004) and 14.6 +/- 1.0 vs. 9.3 +/- 0.7 mmol/l in NIDDM subjects (P < 0.0002). Despite this significant reduction in plasma glucose concentration, insulin secretion rates (ISRs) increased significantly in IGT subjects (513.3 +/- 77.6 vs. 583.1 +/- 100.7 pmol/min; P < 0.03), with a trend toward increasing in NIDDM subjects (561.7 +/- 122.16 vs. 642.8 +/- 128 pmol/min; P = 0.1). These results were compatible with enhanced insulin secretion in the presence of GLP-1. Spectral power was used as a measure of the ability of the beta-cell to secrete insulin in response to small changes in the plasma glucose concentration during the oscillatory infusion. Spectral power for ISR increased from 2.1 +/- 0.9 during saline infusion to 7.4 +/- 1.3 during GLP-1 infusion in IGT subjects (P < 0.004), but was unchanged in NIDDM subjects (1.0 +/- 0.4 to 1.5 +/- 0.6; P = 0.3). We concluded that low dosage GLP-1 improves the ability of the beta-cell to secrete insulin in both IGT and NIDDM subjects, but that the ability to sense and respond to subtle changes in plasma glucose is improved in IGT subjects, with only a variable response in NIDDM subjects. Beta-cell dysfunction was improved by GLP-1 infusion, suggesting that early GLP-1 therapy may preserve beta-cell function in subjects with IGT or mild NIDDM. Topics: Administration, Oral; Adult; Blood Glucose; Diabetes Mellitus, Type 2; Female; Glucagon; Glucagon-Like Peptide 1; Glucose; Glucose Intolerance; Humans; Insulin; Insulin Secretion; Islets of Langerhans; Male; Middle Aged; Peptide Fragments; Protein Precursors | 1998 |
The effect of glucose and glucagon-like peptide-1 stimulation on insulin release in the perfused pancreas in a non-insulin-dependent diabetes mellitus animal model.
This study was designed to investigate the effect of glucogon-like peptide-1 (GLP-1) on pancreatic beta-cell function in normal, Zucker diabetic fatty (ZDF) rats, a model for non-insulin-dependent diabetes mellitus (NIDDM or type II diabetes) and their heterozygous siblings. Pancreas perfusion and enzyme-linked immunosorbent assay (ELISA) were used to detect the changes in insulin release under fasting and hyperglycemic conditions and following stimulation with GLP-1. Animals from the ZDF/Gmi-fa rats (ZDF) were grouped according to age, sex, and phenotype (obese or lean), and compared with LA lean rats. Glucose stimulation (10 mmol/L) in obese rats showed repressed response in insulin release. Glucose plus GLP-1 stimulation caused increased insulin release in all groups. The degree of this response differed between groups: lean > obese; young > adult; female > male. The LA lean control group was most sensitive, while the ZDF overtly diabetic group had the lowest response. In addition, the pulsatile pattern of insulin secretion was suppressed in ZDF rats, especially in obese groups. These results support the hypothesis that GLP-1 can effectively stimulate insulin secretion. Insulin release was defective in ZDF obese rats and could be partially restored with GLP-1. ZDF lean rats also showed suppression of beta-cell function and there was a difference in beta-cell function related to sex in ZDF strain. This study documents the efficacy of GLP-1 to stimulate insulin release and contributes to our understanding of the pathophysiological mechanisms underlying NIDDM. Topics: Animals; Diabetes Mellitus, Type 2; Female; Glucagon; Glucagon-Like Peptide 1; Glucose; Insulin; Insulin Secretion; Male; Obesity; Pancreas; Peptide Fragments; Perfusion; Protein Precursors; Rats; Sex Factors | 1998 |
The ageing entero-insular axis.
Ageing is one of the major risk factors for glucose intolerance including impaired glucose tolerance and Type II (non-insulin-dependent) diabetes mellitus. Reduced insulin secretion has been described as part of normal ageing although there is no information on age-related changes in the secretion of the major insulinotropic hormones, glucose-dependent insulinotropic polypeptide (GIP) and glucagon-like peptide (7-36 amide) (GLP-1). We assessed the entero-insular axis in 6 young premenopausal and 6 older postmenopausal women following treatment with oral carbohydrate. Insulin and glucose integrated responses were similar in the younger and older groups. Total integrated responses for GIP and GLP-1 were considerably greater in the older subjects. A positive correlation between age and total integrated responses for glucose (r = 0.65; p < 0.02) as well as GLP-1 (r = 0.85; p < 0.001) was seen. We hypothesise that an age-related impairment of insulin secretion to insulinotropic hormones, GIP and GLP-1, contributes to a reduction in glucose tolerance in this age group. The pronounced compensatory increase in postprandial secretion of GIP and GLP-1 provides further evidence not only for the negative feedback relation between incretin and insulin secretion but also for the importance of the entero-insular axis in the regulation of insulin secretion. Topics: Acetaminophen; Adult; Aged; Aging; Blood Glucose; Body Mass Index; Body Weight; Diabetes Mellitus, Type 2; Dietary Carbohydrates; Female; Gastric Inhibitory Polypeptide; Glucagon; Glucagon-Like Peptide 1; Glucagon-Like Peptides; Glucose Intolerance; Humans; Insulin; Insulin Secretion; Peptide Fragments; Postmenopause; Premenopause; Risk Factors | 1998 |
Effects of glucagon-like peptide-1 on islet function and insulin sensitivity in noninsulin-dependent diabetes mellitus.
Administration of the truncated glucagon-like peptide 1 (GLP-1) has been considered for treatment of noninsulin-dependent diabetes mellitus (NIDDM). We studied its antidiabetogenic mechanism by examining its influences on islet function and peripheral insulin sensitivity in six subjects (aged 56-74 yr) with well-controlled NIDDM. Islet function was evaluated with arginine stimulation at three plasma glucose levels (fasting, 14 mmol/L, and > 28 mmol/L). GLP-1 (1.5 pmol/kg per min iv) increased serum insulin levels at fasting glucose (P = 0.028), at 14 mmol/L glucose (P = 0.028), and at 28 mmol/L glucose (P = 0.028). The acute insulin response (AIR) to 5 g iv arginine was increased by GLP-1 at 14 mmol/L glucose (P = 0.028), and the slopeAIR, i.e., the glucose potentiation of insulin secretion, was markedly increased by GLP-1 (P = 0.028). Plasma glucagon levels were reduced by GLP-1 (P = 0.028), and arginine-stimulated glucagon secretion (AGR) was inhibited by GLP-1 at 14 (P = 0.046) and 28 mmol/L glucose (P = 0.028). Glucose-induced inhibition of arginine-stimulated glucagon secretion (slopeAGR) was not significantly affected by GLP-1. In contrast, GLP-1 did not affect the low insulin sensitivity during a hyperinsulinemic, euglycemic clamp. Thus, GLP-1 improves islet dysfunction in diabetes, mainly by increasing the glucose-induced potentiation of insulin secretion. In contrast, the peptide does not seem to improve insulin resistance in NIDDM. Topics: Aged; Diabetes Mellitus, Type 2; Female; Glucagon; Glucagon-Like Peptide 1; Humans; Insulin; Insulin Resistance; Insulin Secretion; Islets of Langerhans; Male; Middle Aged; Peptides | 1997 |
Incretin hormone expression in the gut of diabetic mice and rats.
To elucidate the question of whether production of the insulinotropic gut hormones glucose-dependent insulinotropic polypeptide (GIP) and glucagon-like peptide-1 (GLP-1) is altered by a diabetic metabolic state, their intestinal expression pattern was evaluated. Two rodent models for diabetes mellitus were used, non-obese diabetic (NOD) mice as a model for insulin-dependent diabetes and Zucker diabetic fatty (ZDF) rats for non-insulin-dependent diabetes mellitus (NIDDM). Expression of both incretin hormones followed typical patterns, which were similar in both animals and unaltered by the diabetic state. The GIP gene was greatly expressed in the duodenum, jejunum, and ileum, with a continuous decrease from the upper to lower intestines. This pattern was observed in both NOD mice and ZDF rats regardless of the diabetic state. This expression data was corroborated by radioimmunoassay (RIA) analysis of the gene product GIP. Expression of the proglucagon gene encoding GLP-1 had an opposite appearance. The highest expression was seen in the large bowel and the ileum. RIA analysis of the gene product GLP-1 mirrored these data. Although the distribution pattern was similar in both animal models, in contrast to diabetic NOD mice, a regulated expression was found in diabetic ZDF rats. Compared with lean nondiabetic controls, fatty hyperglycemic animals showed an increased expression of the proglucagon gene in the colon and a concomitant reduction in the small intestine. This was mirrored by the GLP-1 content of the colon and ileum. Overall, basal GLP-1 plasma levels were increased in ZDF rats (17.0 +/- 2.8 pmol) compared with lean Zucker rats (12.4 +/- 1.8 pmol). In conclusion, incretin hormone expression (GIP and GLP-1) follows specific patterns throughout the gut and is unaltered by the diabetic state. In ZDF rats, regulation of proglucagon expression occurs mainly in the large intestine. Topics: Animals; Blotting, Northern; Colon; Diabetes Mellitus, Type 1; Diabetes Mellitus, Type 2; Disease Models, Animal; Gastric Inhibitory Polypeptide; Gene Expression; Glucagon; Glucagon-Like Peptide 1; Glucagon-Like Peptides; Intestinal Mucosa; Intestine, Small; Intestines; Mice; Mice, Inbred NOD; Peptide Fragments; Proglucagon; Protein Precursors; Rats; Rats, Zucker; Rectum; RNA, Messenger; Tissue Distribution | 1997 |
Extrapancreatic action of truncated glucagon-like peptide-I in Otsuka Long-Evans Tokushima Fatty rats, an animal model for non-insulin-dependent diabetes mellitus.
To clarify the mechanism(s) of the antidiabetic effects of truncated glucagon-like peptide-1 (GLP-1) in diabetics, we examined its insulinotropic and extrapancreatic effects in a newly established strain of spontaneously non-insulin-dependent diabetic (NIDDM) rats, Otsuka Long-Evans Tokushima Fatty (OLETF) rats, that received a continuous infusion of truncated GLP-1 620 pmol/d/kg (G group, n = 12) or of vehicle (V group, n = 12) for 4 weeks by Alzet pump. Nonfasting plasma glucose levels were significantly lower (P < .05) in the G group than in the V group (7.0 +/- 0.67 v 9.1 +/- 1.7 mmol/L), and fasting plasma immunoreactive insulin (IRI) levels were lower in the former than in the latter (0.63 +/- 0.31 v 0.78 +/- 0.25 nmol/L). At day 15 of infusion, the G group showed an attenuated plasma glucose response to an oral glucose load, but had plasma IRI levels comparable to those in the V group. A long-term infusion of truncated GLP-1 increased the glucose infusion rate (GIR) significantly (P < .05) during a euglycemic-hyperinsulinemic clamp test (59.0 +/- 14.8 mumol/kg/min for group G v 38.9 +/- 12.2 for group V), but hepatic glucose output (HGO) did not differ significantly for either group. Uptake of 2-deoxy-D-glucose (2DG) by peripheral muscles in the G group was as much as 2.4-fold higher than in the V group (5.52 +/- 2.04 v 2.29 +/- 0.97 mumol/100 g muscle weight/min). We conclude from these data that truncated GLP-1, in addition to its well-known incretin effect, is capable of augmenting insulin action in peripheral tissues of diabetics, which can contribute, in part, to improve glucose intolerance in OLETF rats. Topics: Administration, Oral; Animals; Blood Glucose; Diabetes Mellitus, Type 2; Fasting; Female; Glucagon; Glucagon-Like Peptide 1; Glucose; Infusion Pumps; Insulin; Male; Pancreas; Peptide Fragments; Protein Precursors; Radioimmunoassay; Rats; Rats, Inbred Strains; Rats, Mutant Strains | 1997 |
Anchoring of protein kinase A facilitates hormone-mediated insulin secretion.
Impaired insulin secretion is a characteristic of non-insulin-dependent diabetes mellitus (NIDDM). One possible therapeutic agent for NIDDM is the insulinotropic hormone glucagon-like peptide 1 (GLP-1). GLP-1 stimulates insulin secretion through several mechanisms including activation of protein kinase A (PKA). We now demonstrate that the subcellular targeting of PKA through association with A-kinase-anchoring proteins (AKAPs) facilitates GLP-1-mediated insulin secretion. Disruption of PKA anchoring by the introduction of anchoring inhibitor peptides or expression of soluble AKAP fragments blocks GLP-1 action in primary islets and cAMP-responsive insulin secretion in clonal beta cells (RINm5F). Displacement of PKA also prevented cAMP-mediated elevation of intracellular calcium suggesting that localized PKA phosphorylation events augment calcium flux. Topics: Animals; Calcium; Cells, Cultured; Cyclic AMP-Dependent Protein Kinases; Diabetes Mellitus, Type 2; Glucagon; Glucagon-Like Peptide 1; Insulin; Insulin Secretion; Pancreas; Peptide Fragments; Protein Precursors; Rats | 1997 |
The human glucagon-like peptide-1 (GLP-1) receptor. Cloning and functional expression.
Topics: Amino Acid Sequence; Animals; Binding, Competitive; Calcium; Cloning, Molecular; COS Cells; Cyclic AMP; Diabetes Mellitus, Type 2; Glucagon; Glucagon-Like Peptide 1; Glucagon-Like Peptide-1 Receptor; Glucagon-Like Peptides; Humans; Kinetics; Molecular Sequence Data; Peptide Fragments; Peptides; Polymerase Chain Reaction; Protein Precursors; Rats; Receptors, Glucagon; Recombinant Proteins; Sequence Alignment; Sequence Homology, Amino Acid; Transfection | 1997 |
Glucagon-like-peptide-1 (7-36) amide improves glucose sensitivity in beta-cells of NOD mice.
The effect of the insulinotropic gut hormone glucagon-like-peptide-1 (GLP-1) was studied on the residual insulin capacity of prediabetic nonobese diabetic (NOD) mice, a model of insulin-dependent diabetes mellitus (type 1). This was done using isolated pancreas perfusion and dynamic islet perifusion. Prediabetes was defined by insulitis and fasting normoglycemia. Insulitis occurred in 100% of NOD mice beyond the age of 12 weeks. K values in the intravenous glucose tolerance test were reduced in 20-week-old NOD mice compared with age matched non-diabetes-prone NOR (nonobese resistant) mice (2.4 +/- 1.1 vs 3.8 +/- 1.5% min-1, P < 0.05). Prediabetic NOD pancreases were characterized by a complete loss of the glucose-induced first-phase insulin release. In perifused NOD islets GLP-1, at concentrations already effective in normal islets, left the insulin release unaltered. However, a significant rise of glucose-dependent insulin secretion occurred for GLP-1 concentrations > 0.1 nM. This was obtained with both techniques, dynamic islet perifusion and isolated pancreas perfusion, indicating a direct effect of GLP-1 on the beta-cell. Analysis of glucose-insulin dose-response curves revealed a marked improvement of glucose sensitivity of the NOD endocrine pancreas in the presence of GLP-1 (half-maximal insulin output without GLP-1 15.2 mM and with GLP-1 9.4 mM, P < 0.002). We conclude that GLP-1 can successfully reverse the glucose sensing defect of islets affected by insulitis. Topics: Animals; Cells, Cultured; Diabetes Mellitus, Type 2; Glucagon; Glucagon-Like Peptide 1; Glucagon-Like Peptides; Glucose; In Vitro Techniques; Insulin; Insulin Secretion; Islets of Langerhans; Kinetics; Mice; Mice, Inbred NOD; Mice, Mutant Strains; Pancreas; Peptide Fragments; Time Factors | 1996 |
Normalization of insulin responses to glucose by overnight infusion of glucagon-like peptide 1 (7-36) amide in patients with NIDDM.
Glucagon-like peptide 1 (GLP-1) is a natural enteric incretin hormone, which is a potent insulin secretogogue in vitro and in vivo in humans. Its effects on overnight glucose concentrations and the specific phases of insulin response to glucose and nonglucose secretogogues in subjects with NIDDM are not known. We compared the effects of overnight intravenous infusion of GLP-1 (7-36) amide with saline infusion, on overnight plasma concentrations of glucose, insulin, and glucagon in eight subjects with NIDDM. The effects on basal (fasting) beta-cell function and insulin sensitivity were assessed using homeostasis model assessment (HOMA) and compared with seven age- and weight-matched nondiabetic control subjects. The GLP-1 infusion was continued, and the first- and second-phase insulin responses to a 2-h 13 mmol/l hyperglycemic clamp and the insulin response to a subsequent bolus of the nonglucose secretogogue, arginine, were measured. These were compared with similar measurements recorded after the overnight saline infusion and in the control subjects who were not receiving GLP-1. The effects on stimulated beta-cell function of lowering plasma glucose per se were assessed by a separate overnight infusion of soluble insulin, the rate of which was adjusted to mimic the blood glucose profile achieved with GLP-1. Infusion of GLP-1 resulted in significant lowering of overnight plasma glucose concentrations compared with saline, with mean postabsorptive glucose concentrations (2400-0800) of 5.6 +/- 0.8 and 7.8 +/- 1.4 mmol/l, respectively (P < 0.0002). Basal beta-cell function assessed by HOMA was improved from geometric mean (1 SD range), 45% beta (24-85) to 91% beta (55-151) by GLP-1 (P < 0.0004). First-phase incremental insulin response to glucose was improved by GLP-1 from 8 pmol/l (-8-33) to 116 pmol/l (12-438) (P < 0.005), second-phase insulin response to glucose from 136 pmol/l (53-352) to 1,156 pmol/l (357-3,748) (P < 0.0002), and incremental insulin response to arginine from 443 pmol/l (172-1,144) to 811 pmol/l (272-2,417) (P < 0.002). All responses on GLP-1 were not significantly different from nondiabetic control subjects. Reduction of overnight glucose by exogenous insulin did not improve any of the phases of stimulated beta-cell function. Prolonged intravenous infusion of GLP-1 thus significantly lowered overnight glucose concentrations in subjects with NIDDM and improved both basal and stimulated beta-cell function to nondiabetic levels. It may pro Topics: Blood Glucose; Diabetes Mellitus, Type 2; Female; Glucagon; Glucagon-Like Peptide 1; Glucagon-Like Peptides; Homeostasis; Humans; Infusions, Intravenous; Insulin; Insulin Secretion; Islets of Langerhans; Male; Middle Aged; Models, Biological; Neurotransmitter Agents; Peptide Fragments; Reference Values; Time Factors | 1996 |
Gut incretin hormones in identical twins discordant for non-insulin-dependent diabetes mellitus (NIDDM)--evidence for decreased glucagon-like peptide 1 secretion during oral glucose ingestion in NIDDM twins.
The incremental glucagon-like peptide 1 (GLP-1) and gastric inhibitory polypeptide (GIP) responses (areas under curves; AUCs) were determined during a standard 180-min 75-g oral glucose tolerance test in a group of 12 identical twin pairs discordant for non-insulin-dependent diabetes mellitus (NIDDM) and 13 matched controls without family history of diabetes using highly sensitive and specific radioimmunoassay hormone assays. Data were analysed using multifactor analysis of variance (ANOVA) to identify and correct for possible covariates and to correct for multiple comparisons. Fasting plasma GLP-1 and GIP concentrations were similar in all groups. The twins with frank NIDDM had a decreased incremental GLP-1 response during oral glucose ingestion compared with controls without family history of diabetes (AUC +/- SEM: 0.55 +/- 0.14 vs 1.17 +/- 0.25 (mmol/l) x min, p < 0.05). The incremental GLP-1 secretion in the non-diabetic twins was not significantly different from neither their NIDDM co-twins nor the controls without family history of diabetes. The incremental GIP responses were similar in all study groups. Gender was identified as the major independent covariate for incremental glucose, insulin, GIP and GLP-1 responses, with higher values of all parameters in females. Waist-to-hip ratio and body mass index (BMI) were identified as independent but oppositely directed covariates for the incremental GLP-1 responses (waist-to-hip ratio: r = 0.43, p < 0.02; BMI: r = -0.34, p = 0.06). Incremental GLP-1 responses correlated with incremental insulin responses in the combined study population (N = 37; R = 0.42, p = 0.01). In conclusion, a decreased intestinal GLP-1 secretion may contribute to the abnormal insulin secretion during oral glucose ingestion in NIDDM twins. However, decreased secretion of gut incretin hormones (GLP-1 or GIP) does not explain all of the defects of pancreatic insulin secretion in NIDDM patients/twins or in non-diabetic individuals (identical twins) with a genetic predisposition to NIDDM. Topics: Administration, Oral; Area Under Curve; Body Mass Index; Diabetes Mellitus, Type 2; Fasting; Female; Glucagon; Glucagon-Like Peptide 1; Glucagon-Like Peptides; Glucose; Glucose Tolerance Test; Humans; Insulin; Insulin Secretion; Intestinal Mucosa; Male; Middle Aged; Neurotransmitter Agents; Peptide Fragments; Protein Precursors; Sex Characteristics | 1996 |
The effects of acute hyperglycemia and hyperinsulinemia on plasma leptin levels: its relationships with body fat, visceral adiposity, and age in women.
The acute effects of hyperglycemia and hyperinsulinemia on plasma leptin levels were determined in 42 highly trained women athletes (18-69 yr) and 14 sedentary control women (18-50 yr, body mass index < 25 kg/m2), using the glucose clamp technique. The relationships of body composition, physical fitness, age, and plasma leptin levels were examined in all participants. In addition, the effect of weight loss and aerobic exercise and plasma leptin levels were examined in 4 Newly diagnosed untreated noninsulin-dependent diabetes mellitus patients. The time course of plasma leptin levels changed little from basal during hyperglycemic (approximately 10 mmol/L) or hyperinsulinemic-euglycemic (400-3000 pmol/L) clamp studies in either athletes, controls, or noninsulin-dependent diabetes mellitus patients. A strong correlation between plasma leptin levels and fasting insulin was present (r = 0.60, P < 0.001). Plasma leptin and percent fat were higher in controls than athletes (12.6 vs. 4.0 ng/mL and 33.2 vs. 20.8%; both P < 0.001). The relationships between percent fat (dual-energy x-ray absorptiometry) or intraabdominal adipose tissue (computed tomography) and leptin for the entire group were highly significant (r = 0.70, r = 0.52; P < 0.001). When percent fat was controlled, the relationship between fasting insulin and leptin remained (P < 0.002). There was not a significant association between age and plasma leptin levels in a univariate analysis in this population. However, after adjustment for percent fat, a significant inverse relationship between age and leptin appeared (P < 0.05). The weight loss and aerobic exercise program resulted in an average 6 +/- 0.8 kg wt loss. Leptin levels decreased > 28% in each patient (P < 0.01). In conclusion, neither acute hyperglycemia or hyperinsulinemia affects plasma leptin levels. Percent fat is the strongest predictor of leptin levels, even in lean, highly trained women athletes. Topics: Adipose Tissue; Adolescent; Adult; Age Factors; Aged; Diabetes Mellitus, Type 2; Exercise; Female; Glucagon; Glucagon-Like Peptide 1; Humans; Hyperglycemia; Hyperinsulinism; Leptin; Middle Aged; Peptide Fragments; Protein Precursors; Proteins; Weight Loss | 1996 |
Both subcutaneously and intravenously administered glucagon-like peptide I are rapidly degraded from the NH2-terminus in type II diabetic patients and in healthy subjects.
To fate of exogenous glucagon-like peptide I (GLP-I)(7-36) amide was studied in nondiabetic and type II diabetic subjects using a combination of high-pressure liquid chromatography (HPLC), specific radioimmunoassays (RIAs), and a sensitive enzyme-linked immunosorbent assay (ELISA), whereby intact biologically active GLP-I and its metabolites could be determined. After GLP-I administration, the intact peptide could be measured using an NH2-terminally directed RIA or ELISA, while the difference in concentration between these assays and a COOH-terminal-specific RIA allowed determination of NH2-terminally truncated metabolites. Subcutaneous GLP-I was rapidly degraded in a time-dependent manner, forming a metabolite, which co-eluted on HPLC with GLP-I(9-36) amide and had the same immunoreactive profile. Thirty minutes after subcutaneous GLP-I administration to diabetic patients (n = 8), the metabolite accounted for 88.5 +/- 1.9% of the increase in plasma immunoreactivity determined by the COOH-terminal RIA, which was higher than the levels measured in healthy subjects (78.4 +/- 3.2%; n = 8; P < 0.05). Intravenously infused GLP-I was also extensively degraded, but no significant differences were seen between the two groups. Intact GLP-I accounted for only 19.9 +/- 3.4% of the increase in immunoreactivity measured with the COOH-terminal RIA in normal subjects (n = 8), and 25.0 +/- 4.8% of the increase in diabetic subjects (n = 8), the remainder being the NH2-terminally truncated metabolite. Topics: Adult; Chromatography, High Pressure Liquid; Diabetes Mellitus, Type 2; Enzyme-Linked Immunosorbent Assay; Female; Glucagon; Glucagon-Like Peptide 1; Glucagon-Like Peptides; Humans; Infusions, Intravenous; Injections, Subcutaneous; Male; Middle Aged; Peptide Fragments; Radioimmunoassay; Reference Values; Sensitivity and Specificity; Time Factors | 1995 |
Glucagon-like peptide-1 (GLP-1): a piece of the incretin puzzle.
Topics: Animals; Diabetes Mellitus, Type 2; Glucagon; Glucagon-Like Peptide 1; Glucagon-Like Peptides; Humans; Insulin; Peptide Fragments; Peptides; Protein Precursors; Rodentia | 1995 |
Response of truncated glucagon-like peptide-1 and gastric inhibitory polypeptide to glucose ingestion in non-insulin dependent diabetes mellitus. Effect of sulfonylurea therapy.
Gastric inhibitory polypeptide (tGIP) and truncated glucagon like peptide-1 (GLP-1) are potent gastrointestinal insulinotropic factors (incretin), are most released after a meal or ingestion of glucose in man and animals. To investigate whether sulfonylurea (SU) affects the secretion of incretin, the modulation of plasma GIP and tGLP-1 levels following glucose ingestion in non-insulin-dependent diabetic type 2 patients with or without SU therapy was studied. A 75-G oral glucose tolerance test (OGTT) was carried out on 9 healthy subjects (controls) and 18 patients with non-obese type 2, 9 of whom were treated by diet alone (NIDDM-diet) and the other 9 with SU (glibenclamide 2.5 mg or gliclazide 40 mg) once a day (NIDDM-SU). Plasma GIP was measured by radioimmunoassay (RIA) with R65 antibody, and GLP-1 was measured by RIA with N-terminal-directed antiserum R1043 (GLP-1NT) and C-terminal-directed antiserum R2337 (GLP-1CT). Following OGTT, plasma glucose, GIP, GLP-1NT, and GLP-1CT in type 2 patients increased more markedly than in controls, despite the lower response of insulin. However, there were no significant differences in plasma levels of these peptides between the NIDDM-diet and NIDDM-SU groups. Therefore, it is unlikely that SU is involved in the high response of GIP and GLP-1s to OGTT in type 2 patients. Topics: Administration, Oral; Adult; Blood Glucose; Diabetes Mellitus, Type 2; Female; Gastric Inhibitory Polypeptide; Glucagon; Glucagon-Like Peptide 1; Glucose; Humans; Insulin; Male; Peptide Fragments; Protein Precursors; Sulfonylurea Compounds | 1995 |
Glucagon-like peptide: a therapeutic glimmer.
Topics: Diabetes Mellitus, Type 2; Glucagon; Glucagon-Like Peptide 1; Humans; Peptide Fragments; Protein Precursors | 1994 |
Glucose-dependent alterations of intracellular free calcium by glucagon-like peptide-1(7-36amide) in individual ob/ob mouse beta-cells.
Depolarizing concentrations of glucose produce characteristic alterations of intracellular free Ca2+ ([Ca2+]i) in pancreatic beta-cells. The effects of the proposed incretin, glucagon-like peptide-1(7-36amide) (GLP-1a) on [Ca2+]i were determined from Fura-2 fluorescence ratio imaging of cultured ob/ob mouse pancreatic beta-cells. In control cells, [Ca2+]i is low in 3 mM glucose; increasing [glucose] to 8-12 mM results in an initial dip in [Ca2+]i followed by slow oscillating increases in [Ca2+]i. GLP-1a (0.03-10,000 pM) does not alter [Ca2+]i in 3 mM glucose, but does change the response to elevated glucose (8-12 mM). The time integral of the initial dip is reduced ([GLP-1a] 10-100 pM), and the integral of the [Ca2+]i signal is increased ([GLP-1a] > or = 1 pM). GLP-1a increases the frequency of sustained, stable plateau responses to elevated glucose, and the frequency of large, rapid spikes of increased [Ca2+]i associated with either plateaus, or oscillations. Application of a cAMP analog mimics most of the actions of GLP-1a. Activation of the GLP-1a receptor, or application of cAMP alters pancreatic beta-cell [Ca2+]i only when [glucose] is high. Topics: Animals; Calcium; Cyclic AMP; Diabetes Mellitus, Type 2; Felodipine; Glucagon; Glucagon-Like Peptide 1; Glucagon-Like Peptides; Glucose; In Vitro Techniques; Islets of Langerhans; Mice; Mice, Inbred C57BL; Peptide Fragments | 1994 |
The insulinotropic actions of glucose-dependent insulinotropic polypeptide (GIP) and glucagon-like peptide-1 (7-37) in normal and diabetic subjects.
Despite similar glycemic profiles, higher insulin levels are achieved following oral versus intravenous administration of glucose. This discrepancy is due to the incretin effect and is believed to be mediated via stimulation of beta-cells by hormone(s) released from the gut. The leading gut hormone candidates are glucose-dependent insulinotropic polypeptide (GIP) and glucagon-like peptide (GLP-1). To determine the relative insulinotropic activity of these peptides, we infused GLP-1(7-37) and GIP into normal subjects and patients with non-insulin dependent diabetes mellitus (NIDDM). In normal subjects during euglycemia, GLP-1(7-37) stimulated insulin release, whereas GIP did not. Using the Andres clamp technique, we established stable hyperglycemia for 2 h (5.4 mmol/l above the basal level). During the second hour, either GIP, GLP-1(7-37), or both were infused in normal healthy volunteers and in patients with NIDDM. In normal subjects, at a glucose level of 10.4 mmol/l, the 90-120 min insulin response was 279 pmol/l. GIP at a dose of 1, 2 or 4 pmol/kg/min augmented the 90-120 min insulin response by 69, 841 and 920 pmol/l, while GLP-1(7-37), at a dose of 1.5 pmol/kg/min augmented the insulin response by 2106 pmol/l. When both hormones were administered simultaneously, the augmentation was additive--2813 pmol/l. In the diabetic subjects, GIP had no effect, while GLP-1(7-37) augmented the insulin response by 929 pmol/l. We conclude that in normal healthy subjects, GLP-1(7-37), on a molar basis, is several times more potent than GIP at equivalent glycemic conditions. The additive insulinotropic effect suggests that more than one incretin may be responsible for the greater insulin levels observed following oral administration of glucose compared to the intravenous route. In NIDDM, GIP had no insulinotropic effect, while GLP-1(7-37) had a marked effect. This suggests that GLP-1(7-37) may have therapeutic potential as a hypoglycemic agent in NIDDM patients. Topics: Administration, Oral; Adult; Blood Glucose; Diabetes Mellitus, Type 2; Drug Synergism; Gastric Inhibitory Polypeptide; Glucagon; Glucagon-Like Peptide 1; Glucagon-Like Peptides; Humans; Injections, Intravenous; Insulin; Male; Peptide Fragments; Peptides | 1994 |
Insulinotropic hormone glucagon-like peptide-I(7-37) stimulation of proinsulin gene expression and proinsulin biosynthesis in insulinoma beta TC-1 cells.
Glucagon-like peptide-I(7-37) [GLP-I(7-37)] is an intestinal peptide hormone that is released in response to oral nutrients and that potently augments glucose-mediated insulin secretion. GLP-I(7-37) has potent insulin-releasing activities in vivo in response to oral nutrients, in situ in the isolated perfused pancreas, and in vitro in cultured pancreatic B-cells. As such GLP-I(7-37) is a potent hormonal mediator in the enteroinsular axis involved in the regulation of glucose homeostasis. We now show that in addition to stimulating the release of insulin, GLP-I(7-37) stimulates proinsulin gene expression at the levels of gene transcription and cellular levels of proinsulin messenger RNA as well as the translational biosynthesis of proinsulin. These findings of the positive anabolic actions of GLP-I(7-37) on the synthesis of insulin in B-cells support the notion that GLP-I(7-37) may be of therapeutic use in stimulating the production of insulin in patients with noninsulin-dependent diabetes mellitus and that overproduction of insulin with subsequent hypoglycemia will not occur in response to the administration of GLP-I(7-37). Furthermore, these positive actions of GLP-I(7-37) on insulin production obviate the possibility of B-cell exhaustion in response to such a potent secretagogue. Topics: Animals; Chloramphenicol O-Acetyltransferase; Cyclic AMP; Diabetes Mellitus, Type 2; Gene Expression; Glucagon; Glucagon-Like Peptide 1; Glucagon-Like Peptides; Insulin; Insulin Secretion; Insulinoma; Mice; Pancreatic Neoplasms; Peptide Fragments; Peptides; Proinsulin; Promoter Regions, Genetic; RNA, Messenger; Tumor Cells, Cultured | 1992 |
Antidiabetogenic effect of glucagon-like peptide-1 (7-36)amide in normal subjects and patients with diabetes mellitus.
Glucagon-like peptide-1 (7-36) amide (glucagon-like insulinotropic peptide, or GLIP) is a gastrointestinal peptide that potentiates the release of insulin in physiologic concentrations. Its effects in patients with diabetes mellitus are not known.. We compared the effect of an infusion of GLIP that raised plasma concentrations of GLIP twofold with the effect of an infusion of saline, on the meal-related release of insulin, glucagon, and somatostatin in eight normal subjects, nine obese patients with non-insulin-dependent diabetes mellitus (NIDDM), and eight patients with insulin-dependent diabetes mellitus (IDDM). The blood glucose concentrations in the patients with diabetes were controlled by a closed-loop insulin-infusion system (artificial pancreas) during the infusion of each agent, allowing measurement of the meal-related requirement for exogenous insulin. In the patients with IDDM, normoglycemic-clamp studies were performed during the infusions of GLIP and saline to determine the effect of GLIP on insulin sensitivity.. In the normal subjects, the infusion of GLIP significantly lowered the meal-related increases in the blood glucose concentration (P less than 0.01) and the plasma concentrations of insulin and glucagon (P less than 0.05 for both comparisons). The insulinogenic index (the ratio of insulin to glucose) increased almost 10-fold, indicating that GLIP had an insulinotropic effect. In the patients with NIDDM, the infusion of GLIP reduced the mean (+/- SE) calculated isoglycemic meal-related requirement for insulin from 17.4 +/- 2.8 to 2.0 +/- 0.5 U (P less than 0.001), so that the integrated area under the curve for plasma free insulin was decreased (P less than 0.05) in spite of the stimulation of insulin release. In the patients with IDDM, the GLIP infusion decreased the calculated isoglycemic meal-related insulin requirement from 9.4 +/- 1.5 to 4.7 +/- 1.4 U. The peptide decreased glucagon and somatostatin release in both groups of patients. In the normoglycemic-clamp studies in the patients with IDDM, the GLIP infusion significantly increased glucose utilization (saline vs. GLIP, 7.2 +/- 0.5 vs. 8.6 +/- 0.4 mg per kilogram of body weight per minute; P less than 0.01).. GLIP has an antidiabetogenic effect, and it may therefore be useful in the treatment of patients with NIDDM: Topics: Adult; Aged; Blood Glucose; C-Peptide; Diabetes Mellitus; Diabetes Mellitus, Type 1; Diabetes Mellitus, Type 2; Eating; Female; Glucagon; Glucagon-Like Peptide 1; Glucagon-Like Peptides; Humans; Insulin; Insulin Infusion Systems; Insulin Secretion; Male; Middle Aged; Obesity; Peptide Fragments; Peptides; Somatostatin | 1992 |
Discussing the role of glucagonlike peptide-I.
Topics: Diabetes Mellitus, Type 2; Glucagon; Glucagon-Like Peptide 1; Glucagon-Like Peptides; Humans; Insulin; Peptide Fragments; Protein Precursors | 1992 |
The enteroinsular axis revisited. A novel role for an incretin.
Topics: Blood Glucose; Diabetes Mellitus, Type 1; Diabetes Mellitus, Type 2; Gastric Inhibitory Polypeptide; Glucagon; Glucagon-Like Peptide 1; Glucagon-Like Peptides; Humans; Insulin; Insulin Secretion; Peptide Fragments; Peptides | 1992 |
Proglucagon products in plasma of noninsulin-dependent diabetics and nondiabetic controls in the fasting state and after oral glucose and intravenous arginine.
We investigated the major products of proglucagon (PG) processing in plasma in the fasting state, after intravenous arginine and after an oral glucose load in noninsulin-dependent diabetics (NIDDM) and in weight matched controls using specific radioimmunoassays and analytical gel filtration. In the fasting state the glucagonlike peptide-1 (GLP-1) immunoreactivity was significantly elevated in the NIDDM group compared with the control group. Both after intravenous arginine and after an oral glucose load a rise in the plasma concentrations of all immunoreactive moieties measured was seen. All integrated incremental responses after intravenous arginine were identical in the two groups. After oral glucose the insulin concentrations in plasma were lower and the concentrations of all proglucagon products were higher in the NIDDM group compared to the control group. The gel filtration analysis showed that arginine stimulated the secretion of pancreatic glucagon (PG 33-61), major proglucagon fragment (PG 72-158) and probably GLP-1 (PG 72-107 amide) in both groups, whereas oral glucose stimulated the secretion of glicentin (PG 1-69) and intestinal GLP-1 (PG 78-107 amide), an insulinotropic hormone. The elevated levels of immunoreactive GLP-1 in diabetics in the fasting state were mainly due to an increased concentration of major proglucagon fragment. Topics: Administration, Oral; Adult; Aged; Arginine; Chromatography, Gel; Diabetes Mellitus, Type 2; Fasting; Female; Glucagon; Glucagon-Like Peptide 1; Glucose; Humans; Infusions, Intravenous; Male; Middle Aged; Peptide Fragments; Proglucagon; Protein Precursors; Radioimmunoassay | 1991 |