glucagon-like-peptide-1 has been researched along with Obesity* in 1154 studies
305 review(s) available for glucagon-like-peptide-1 and Obesity
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Mucosal and hormonal adaptations after Roux-en-Y gastric bypass.
The aim of this study was to perform a comprehensive literature review regarding the relevant hormonal and histologic changes observed after Roux-en-Y gastric bypass (RYGB). We aimed to describe the relevant hormonal (glucagon-like peptides 1 and 2 [GLP-1 and GLP-2], peptide YY [PYY], oxyntomodulin [OXM], bile acids [BA], cholecystokinin [CCK], ghrelin, glucagon, gastric inhibitory polypeptide [GIP], and amylin) profiles, as well as the histologic (mucosal cellular) adaptations happening after patients undergo RYGB. Our review compiles the current evidence and furthers the understanding of the rationale behind the food intake regulatory adaptations occurring after RYGB surgery. We identify gaps in the literature where the potential for future investigations and therapeutics may lie. We performed a comprehensive database search without language restrictions looking for RYGB bariatric surgery outcomes in patients with pre- and postoperative blood work hormonal profiling and/or gut mucosal biopsies. We gathered the relevant study results and describe them in this review. Where human findings were lacking, we included animal model studies. The amalgamation of physiologic, metabolic, and cellular adaptations following RYGB is yet to be fully characterized. This constitutes a fundamental aspiration for enhancing and individualizing obesity therapy. Topics: Animals; Blood Glucose; Cholecystokinin; Gastric Bypass; Gastric Inhibitory Polypeptide; Glucagon-Like Peptide 1; Humans; Obesity; Peptide YY | 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 |
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 |
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 |
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 |
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 |
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 |
Efficacy of cardiometabolic drugs in reduction of epicardial adipose tissue: a systematic review and meta-analysis.
Epicardial adipose tissue (EAT) plays an important role in cardiometabolic risk. EAT is a modifiable risk factor and could be a potential therapeutic target for drugs that already show cardiovascular benefits. The aim of this study is to evaluate the effect of cardiometabolic drugs on EAT reduction.. A detailed search related to the effect on EAT reduction due to cardiometabolic drugs, such as glucagon-like peptide-1 receptor agonist (GLP-1 RA), sodium-glucose cotransporter-2 inhibitors (SGLT2-i), and statins was conducted according to PRISMA guidelines. Eighteen studies enrolling 1064 patients were included in the qualitative and quantitative analyses.. All three analyzed drug classes, in particular GLP-1 RA, show a significant effect on EAT reduction (GLP-1 RA standardize mean difference (SMD) = - 1.005; p < 0.001; SGLT2-i SMD = - 0.552; p < 0.001, and statin SMD = - 0.195; p < 0.001). The sensitivity analysis showed that cardiometabolic drugs strongly benefit EAT thickness reduction, measured by ultrasound (overall SMD of - 0.663; 95%CI - 0.79, - 0.52; p < 0.001). Meta-regression analysis revealed younger age and higher BMI as significant effect modifiers of the association between cardiometabolic drugs and EAT reduction for both composite effect and effect on EAT thickness, (age Z: 3.99; p < 0.001 and Z: 1.97; p = 0.001, respectively; BMI Z: - 4.40; p < 0.001 and Z: - 2.85; p = 0.004, respectively).. Cardiometabolic drugs show a significant beneficial effect on EAT reduction. GLP-1 RA was more effective than SGLT2-i, while statins had a rather mild effect. We believe that the most effective treatment with these drugs should target younger patients with high BMI. Topics: Cardiovascular Diseases; Glucagon-Like Peptide 1; Humans; Hydroxymethylglutaryl-CoA Reductase Inhibitors; Obesity; Sodium-Glucose Transporter 2 Inhibitors | 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 |
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 |
Weight loss breaks the bond between nonalcoholic fatty liver disease and cardiovascular diseases: A clinical and epidemiological perspective.
Nonalcoholic fatty liver disease (NAFLD) is a growing health concern that is closely related to obesity and metabolic syndrome. In particular, NAFLD has been increasingly reported in adolescents and young adults in recent years. Cardiovascular diseases (CVDs) such as cardiac remodeling, heart failure, myocardial infarction, valvular heart diseases, and arrhythmia are more common in patients with NAFLD. CVD are the major cause of mortality in NAFLD. Although NAFLD often affects patients with obesity/overweight, it can also affect subjects with normal body mass index (BMI), known as lean NAFLD, which has a strong correlation with CVD. Obesity imposes a considerably increased risk of NAFLD and CVD. Consistently, weight-lowering approaches that can pronouncedly decrease body weight and maintain it in the long term, such as bariatric surgery and treatment with semaglutide and tirzepatide, have been promising in alleviating both CVD and NAFLD. Interestingly, compared with patients with NAFLD and obesity, a minimal amount of weight loss resolves NAFLD in lean patients. Besides the widespread use of bariatric surgery, the development of new GLP-1 agonists and GLP-1 GIP agonists revolutionized the treatment of obesity in recent years. Here, we discuss the interwoven correlation between obesity, NAFLD, and CVD and the benefits of weight-lowering approaches. Topics: Adolescent; Cardiovascular Diseases; Glucagon-Like Peptide 1; Humans; Non-alcoholic Fatty Liver Disease; Obesity; Weight Loss; Young Adult | 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 |
Interactions between Intestinal Homeostasis and NAD
The intestine has garnered attention as a target organ for developing new therapies for impaired glucose tolerance. The intestine, which produces incretin hormones, is the central regulator of glucose metabolism. Glucagon-like peptide-1 (GLP-1) production, which determines postprandial glucose levels, is regulated by intestinal homeostasis. Nicotinamide phosphoribosyltransferase (NAMPT)-mediated nicotinamide adenine dinucleotide (NAD Topics: AMP-Activated Protein Kinases; Biology; Cytokines; Glucagon-Like Peptide 1; Glucose; Glucose Intolerance; Homeostasis; Humans; Incretins; NAD; Nicotinamide Phosphoribosyltransferase; 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 |
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 |
Liraglutide and polycystic ovary syndrome: is it only a matter of body weight?
Despite Polycystic Ovary Syndrome (PCOS) is a very prevalent disorder among women of reproductive age, there is widespread agreement that until now, no pharmacological options are available to tackle the entire spectrum of clinical manifestations encountered in the clinical practice. Obesity and insulin resistance, which commonly characterized this syndrome, prompted the design of studies investigating the effects of glucagon-like peptide 1 (GLP-1) receptor agonists (GLP-1RA) in PCOS. Indeed, a very impressive number of randomized controlled clinical trials (RCTs) and systematic reviews provided robust evidence on the effectiveness of GLP-1RA in PCOS as a new, appealing approach, producing both satisfactory and permanent weight loss, and improvement of insulin resistance at the same time. However, most of the subjects included in the RCTs are PCOS patients with obesity/overweight, whereas a portion of PCOS women, which can even reach 50%, might present a lean phenotype. Moreover, some benefits on clinical and metabolic features of PCOS may not have fully emerged due to the low or medium doses employed in the vast majority of the current studies. Thus, pitfalls in the methodology of these studies have led sometimes to misleading results. In addition, some aspects of GLP-1 beyond weight loss, such as preclinical evidence on GLP-1 effects in directly modulating the hypothalamus-pituitary-gonadal axis, or the effects of GLP-1RA on clinical and biochemical expression of hyperandrogenism, still deserve a greater insight, especially in light of a possible therapeutic use in PCOS women independently of obesity. Aim of this review is to further unravel the possible role of GLP-1 in PCOS pathogenesis, tempting to provide additional supports to the rationale of treatment with GLP-1RA in the management of PCOS also independent of weight loss. For this purpose, the outcomes of RCTs investigating in PCOS the anthropometric and metabolic changes have been treated separately to better underpin the effects of GLP-1 RA, in particular liraglutide, beyond weight loss. Topics: Body Weight; Female; Glucagon-Like Peptide 1; Humans; Insulin Resistance; Liraglutide; Obesity; Polycystic Ovary Syndrome; Weight Loss | 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 |
Design of novel therapeutics targeting the glucose-dependent insulinotropic polypeptide receptor (GIPR) to aid weight loss.
With obesity rates growing globally, there is a paramount need for new obesity pharmacotherapies to tackle this pandemic.. This review focuses on the design of therapeutics that target the glucose-dependent insulinotropic polypeptide receptor (GIPR) to aid weight loss. The authors highlight the paradoxical observation that both GIPR agonism and antagonism appear to provide metabolic benefits when combined with glucagon-like peptide-1 receptor (GLP-1 R) agonism. The therapeutic potential of compounds that target the GIPR alongside the GLP-1 R and the glucagon receptor are discussed, and the impressive clinical findings of such compounds are reviewed.. In this area, the translation of pre-clinical findings to clinical studies appears to be particularly difficult. Well-designed physiological studies in man are required to answer the paradox highlighted above, and to support the safe future development of a combination of GLP-1 R/GIPR targeting therapies. Topics: Gastric Inhibitory Polypeptide; Glucagon-Like Peptide 1; Glucagon-Like Peptide-1 Receptor; Humans; Obesity; Weight Loss | 2023 |
GLP-1 analogs and regional adiposity: A systematic review and meta-analysis.
Glucagon-like peptide 1 (GLP-1) analogs regulate body weight and liver steatosis. Different body adipose tissue (AT) depots exhibit biological variability. Accordingly, GLP-1 analog effects on AT distribution are unclear.. To investigate GLP1-analog effects on adiposity distribution.. PubMed, Cochrane, and Scopus databases were screened for eligible randomized human trials. Pre-defined endpoints included visceral AT (VAT), subcutaneous AT (SAT), total AT (TAT), epicardial AT (EAT), liver AT (LAT), and waist-to-hip ratio (W:H). Search was conducted until May 17, 2022.. Data extraction and bias assessment were performed by two independent investigators. Treatment effects were estimated using random effects models. Analyses were performed on Review Manager v5.3.. Out of the 367 screened studies, 45 were included in the systematic review and 35 were used in the meta-analysis. GLP-1 analogs reduced VAT, SAT, TAT, LAT, and EAT, with non-significant effects on W:H. Overall bias risk was low.. GLP-1 analog treatment reduces TAT, affecting most studied AT depots, including the pathogenic VAT, EAT, and LAT. GLP-1 analogs may have significant roles in combating metabolic, obesity-associated diseases via reductions of key AT depot volumes. Topics: Adiposity; Body Weight; Glucagon-Like Peptide 1; Humans; Liver; Obesity | 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 |
Brown Adipose Tissue: A New Potential Target for Glucagon-like Peptide 1 Receptor Agonists in the Treatment of Obesity.
Adipose tissue can be divided into white adipose tissue (WAT), brown adipose tissue (BAT), and beige adipose tissue, according to the differences in morphology. WAT acts as a buffer for increased energy intake and decreased energy expenditure during the development of obesity, resulting in visceral and ectopic WAT accumulation. These WAT depots are strongly associated with chronic systemic inflammation, insulin resistance, and cardiometabolic risk related to obesity. They represent a primary weight loss target in anti-obesity management. Second-generation anti-obesity medications glucagon-like peptide-1 receptor agonists (GLP-1RAs) cause weight loss and improve body composition by reducing visceral and ectopic fat depots of WAT, resulting in improved cardiometabolic health. Recently, the understanding of the physiological significance of BAT beyond its primary function in generating heat through non-shivering thermogenesis has been expanded. This has raised scientific and pharmaceutical interest in the manipulation of BAT to further enhance weight reduction and body weight maintenance. This narrative review focuses on the potential impact of GLP-1 receptor agonism on BAT, particularly in human clinical studies. It provides an overview of the role of BAT in weight management and highlights the need for further research to elucidate the mechanisms by which GLP-1RAs affect energy metabolism and weight loss. Despite encouraging preclinical data, limited clinical evidence supports the notion that GLP-1RAs contribute to BAT activation. Topics: Adipose Tissue, Brown; Adipose Tissue, White; Animals; Cardiovascular Diseases; Energy Metabolism; Glucagon-Like Peptide 1; Glucagon-Like Peptide-1 Receptor; Humans; Obesity; Thermogenesis; Weight Loss | 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 |
Chronic Kidney Disease and Obesity.
There is a pandemic of obesity worldwide and in Europe up to 30% of the adult population is already obese. Obesity is strongly related to the risk of CKD, progression of CKD, and end-stage renal disease (ESRD), also after adjustment for age, sex, race, smoking status, comorbidities, and laboratory tests. In the general population, obesity increases the risk of death. In nondialysis-dependent CKD patients, the association between body mass index and weight with mortality is controversial. In ESRD patients, obesity is paradoxically associated with better survival. There are only a few studies investigating changes in weight in these patients and in most weight loss was associated with higher mortality. However, it is not clear if weight change was intentional or unintentional and this is an important limitation of these studies. Management of obesity includes life-style interventions, bariatric surgery, and pharmacotherapy. In the last 2 years, a long-acting glucagon-like peptide-1 (GLP-1) receptor agonist and GLP-1 and glucose-dependent insulinotropic polypeptide receptor agonist were shown to be effective in managing weight loss in non-CKD patients, but we are awaiting results of more definitive studies in CKD patients. Topics: Adult; Glucagon-Like Peptide 1; Humans; Kidney Failure, Chronic; Obesity; Renal Insufficiency, Chronic; Weight Loss | 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 |
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 |
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 |
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 |
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 |
[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 |
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 |
The role of glia in the physiology and pharmacology of glucagon-like peptide-1: implications for obesity, diabetes, neurodegeneration and glaucoma.
The medical applications of glucagon-like peptide-1 receptor (GLP-1R) agonists is evergrowing in scope, highlighting the urgent need for a comprehensive understanding of the mechanisms through which GLP-1R activation impacts physiology and behaviour. A new area of research aims to elucidate the role GLP-1R signalling in glia, which play a role in regulating energy balance, glycemic control, neuroinflammation and oxidative stress. Once controversial, existing evidence now suggests that subsets of glia (e.g. microglia, tanycytes and astrocytes) and infiltrating macrophages express GLP-1Rs. In this review, we discuss the implications of these findings, with particular focus on the effectiveness of both clinically available and novel GLP-1R agonists for treating metabolic and neurodegenerative diseases, enhancing cognition and combating substance abuse. 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: Astrocytes; Diabetes Mellitus; Glaucoma; Glucagon-Like Peptide 1; Glucagon-Like Peptide-1 Receptor; Humans; Obesity | 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 |
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 |
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 |
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 |
Clinical review of subcutaneous semaglutide for obesity.
The purpose of this review paper is to review the efficacy and safety of subcutaneous semaglutide, marketed as Wegovy, a glucagon-like peptide-1 receptor agonist for obesity management.. A MEDLINE search (1970 to June 2021) was conducted to identify Phase 3 trials of subcutaneous semaglutide for obesity management. Published Phase 3 trials from The Semaglutide Treatment Effect in People with obesity (STEP) program were reviewed and summarized.. Based on four Phase 3 trials, subcutaneous semaglutide as 2.4 mg once weekly was compared in efficacy and safety among 5000 randomized participants who were overweight or had obesity. A change in body weight from baseline to end of study was the primary outcome in the STEP program. Participants who received semaglutide had a dose-dependent reduction in body weight from baseline, compared to placebo. Higher percentages of participants had 5%-10% weight reduction from baseline when receiving subcutaneous semaglutide. The patient population was mainly middle-aged female participants with Class II obesity. Additional studies are needed, especially active-comparator trials, to determine the efficacy and safety of semaglutide in a diverse patient population.. Subcutaneous semaglutide is another available option as adjunct therapy to lifestyle modifications for people who are overweight or have obesity based on body weight and body mass index. It resulted in more weight reduction than placebo with gastrointestinal adverse events being the most common safety concerns. Clinical utilization of subcutaneous semaglutide will be determined, as insurance coverage will be a limitation for this new medication. Topics: Adult; Body Mass Index; Body Weight; Clinical Trials, Phase III as Topic; Dose-Response Relationship, Drug; Female; Glucagon-Like Peptide 1; Glucagon-Like Peptides; Humans; Injections, Subcutaneous; Male; Middle Aged; Obesity; Overweight; Randomized Controlled Trials as Topic; Weight Loss | 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 |
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 |
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 |
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 |
Effect of glucagon-like peptide-1 receptor agonists on cardiovascular events in overweight or obese adults without diabetes: A meta-analysis of placebo-controlled randomized trials.
Our aim was to study the effect of glucagon-like peptide-1 receptor agonists (GLP-1 RA) on the risk of any cardiovascular event in adults with overweight or obesity and without diabetes. We conducted a random-effects meta-analysis of placebo-controlled randomized controlled trials. Nine trials were eligible and, in total, 11 430 patients were included, of which 7702 (67%) were submitted to treatment with GLP-1 RA. During follow-up, 673 participants receiving GLP-1 RA treatment (8.7%) and 416 participants receiving placebo (11.2%) had a cardiovascular event. Treatment with GLP-1 RA versus placebo resulted in a reduction in the risk of any cardiovascular event (RR = 0.81, CI 0.70-0.92; p = .001). In overweight or obese adults without diabetes, treatment with GLP-1 RA reduced the risk of cardiovascular events. Our findings support the use of GLP-1 RA for reducing the cardiovascular risk of these patients. Topics: Adult; Cardiovascular Diseases; Diabetes Mellitus; Glucagon-Like Peptide 1; Glucagon-Like Peptide-1 Receptor; Humans; Obesity; Overweight; Randomized Controlled Trials as Topic | 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 |
Roles of glucose-dependent insulinotropic polypeptide in diet-induced obesity.
Glucose-dependent insulinotropic polypeptide (GIP) and glucagon-like peptide-1 (GLP-1) are incretins that play an important role in glucose metabolism, by increasing glucose-induced insulin secretion from pancreatic β-cells and help regulate bodyweight. Although they show a similar action on glucose-induced insulin secretion, two incretins are distinct in various aspects. GIP is secreted from enteroendocrine K cell mainly expressed in the upper small intestine, and GLP-1 is secreted from enteroendocrine L cells mainly expressed in the lower small intestine and colon by the stimulation of various nutrients. The mechanism of GIP secretion induced by nutrients, especially carbohydrates, is different from that of GLP-1 secretion. GIP promotes fat deposition in adipose tissue, and contributes to fat-induced obesity. In contrast, GLP-1 participates in reducing bodyweight by suppressing food consumption and/or slowing gastric emptying. There is substantial evidence that GIP and GLP-1 might differently contribute to bodyweight control. Although meal contents influence both glycemic and weight control, we do not fully understand whether incretin actions differ depending on the contents of the meal and what kind of signaling is involved in its context. We focus on the molecular mechanism of GIP secretion induced by nutrients, as well as the roles of GIP in weight changes caused by various diets. Topics: Blood Glucose; Diet; Gastric Inhibitory Polypeptide; Glucagon-Like Peptide 1; Glucose; Humans; Incretins; Insulin; Obesity | 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 |
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 |
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 |
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 |
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 |
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 |
Therapy of obesity in women with PCOS using GLP-1 analogues - benefits and limitations [Terapia otyłości u kobiet z PCOS przy zastosowaniu analogów GLP-1 - korzyści i ograniczenia].
Polycystic ovary syndrome (PCOS) is a heterogeneous endocrine disorder among women of reproductive age. The incidence ranges from approx. 6% to 20%. PCOS is characterized by a spectrum of symptoms and clinical features that includes ovarian dysfunction, clinical and/or biochemical hyperandrogenism, and ultrasound evidence of morphologically polycystic ovaries. Obesity is present in 40-70% of patients with the syndrome. Adiposity is involved in exacerbating the negative effects of insulin resistance, hyperinsulinaemia, and hyperandrogenaemia in the course of PCOS. Therefore, it is essential to maintain normal weight or effectively treat overweight/obesity in patients suffering from this endocrinopathy. Apart from diet and lifestyle interventions, an appropriate pharmacological or surgical treatment should be selected for the individual patient. Evidence-based data have unequivocally proven the validity of the use of glucagon-like peptide 1 (GLP-1) analogues in the treatment of overweight/obese patients with PCOS. The result of the GLP-1 therapy is not only a reduction of body weight but also an improvement in insulin resistance and a decrease in hyperandrogenaemia. It also seems that this treatment method increases spontaneous and in-vitro pregnancy rates. Therefore, the GLP-1 treatment of obese PCOS women is a new therapeutic opportunity not only for weight loss but also for a wide range of benefits. This review summarizes and discusses findings regarding obesity and its relation to hyperandrogenism and insulin resistance in PCOS, with special attention paid to the pharmacological treatment of adiposity with GLP-1 analogues. Topics: Female; Glucagon-Like Peptide 1; Humans; Hyperandrogenism; Insulin Resistance; Obesity; Overweight; Polycystic Ovary Syndrome | 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 Insights in the Physiopathology and Management of Obesity-Related Kidney Disease.
Obesity is recognized as an independent risk factor for the development of kidney disease, which has led to the designation of obesity-related glomerulopathy (ORG). Common renal features observed in this condition include glomerular hypertrophy, glomerulosclerosis, haemodynamic changes and glomerular filtration barrier defects. Additionally, and although less studied, obesity-related kidney disease also involves alterations in renal tubules, including tubule hypertrophy, lipid deposition and tubulointerstitial fibrosis. Although not completely understood, the harmful effects of obesity on the kidney may be mediated by different mechanisms, with alterations in adipose tissue probably playing an important role. An increase in visceral adipose tissue has classically been associated with the development of kidney damage, however, recent studies point to adipose tissue surrounding the kidney, and specifically to the fat within the renal sinus, as potentially involved in the development of ORG. In addition, new strategies for the treatment of patients with obesity-related kidney disease are focusing on the management of obesity. In this regard, some non-invasive options, such as glucagon-like peptide-1 (GLP-1) receptor agonists or sodium-glucose cotransporter-2 (SGLT2) inhibitors, are being considered for application in the clinic, not only for patients with diabetic kidney disease but as a novel pharmacological strategy for patients with ORG. In addition, bariatric surgery stands as one of the most effective options, not only for weight loss but also for the improvement of kidney outcomes in obese patients with chronic kidney disease. Topics: Diabetic Nephropathies; Glucagon-Like Peptide 1; Humans; Hypertrophy; Lipids; Obesity; Sodium-Glucose Transporter 2 | 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 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 |
Anthocyanins and Curcumin: Possible Abilities of Prevention of Diabetes and Obesity via Stimulation of Glucagon-Like Peptide-1 Secretion and Induction of Beige Adipocyte Formation.
There is growing interest in the health benefits of natural plant pigments such as anthocyanins and curcumin. In this review, we introduce how these pigments can contribute to the prevention of diabetes and obesity by stimulating glucagon-like peptide-1 (GLP-1) secretion or inducing beige adipocyte formation. Of the anthocyanins, delphinidin 3-rutinoside (D3R) was shown to increase GLP-1 secretion. Pre-administered D3R-rich blackcurrant extract (BCE) significantly ameliorated glucose tolerance after intraperitoneal glucose injection in rats by stimulating the secretion of GLP-1 and subsequently inducing insulin secretion. D3R did not break down significantly in the gastrointestinal tract for at least 45-60 min after BCE administration. An increase in endogenous GLP-1 secretion induced by food-derived factors may help to reduce the dosages of diabetic medicines and prevent diabetes. Curcumin has various biological functions, including anti-obesity and anti-diabetic properties. However, high doses of curcumin have been administered in most animal and human trials to date, due mainly to the poor solubility of native curcumin in water and its low oral bioavailability. We demonstrated that a highly dispersible and bioavailable curcumin formulation (HC), but not native curcumin, induces the formation of beige adipocytes. Furthermore, co-administration of HC and artepillin C (a characteristic constituent of Brazilian propolis) at lower doses significantly induces beige adipocyte formation in mice, but administration of the same dose of HC or artepillin C alone does not. Our studies demonstrate that curcumin formulations or the co-administration of curcumin with other food-derived factors provide effects that native curcumin alone does not. Topics: Adipocytes, Beige; Animals; Anthocyanins; Curcumin; Diabetes Mellitus; Glucagon-Like Peptide 1; Glucose; Humans; Mice; Obesity; Rats; Ribes | 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 |
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 |
Reappraising the role of the vagus nerve in GLP-1-mediated regulation of eating.
Here, we provide a focused review of the evidence for the roles of the vagus nerve in mediating the regulatory effects of peripherally and centrally produced GLP-1 on eating behaviour and energy balance. We particularly focus on recent studies which have used selective genetic, viral, and transcriptomic approaches to provide important insights into the anatomical and functional organisation of GLP-1-mediated gut-brain signalling pathways. A number of these studies have challenged canonical ideas of how GLP-1 acts in the periphery and the brain to regulate eating behaviour, with important implications for the development of pharmacological treatments for obesity. 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: Glucagon-Like Peptide 1; Glucagon-Like Peptide-1 Receptor; Humans; Obesity; Signal Transduction; Vagus Nerve | 2022 |
Brain GLP-1 and the regulation of food intake: GLP-1 action in the brain and its implications for GLP-1 receptor agonists in obesity treatment.
This review considers the similarities and differences between the physiological systems regulated by gut-derived and neuronally produced glucagon-like peptide 1 (GLP-1). It addresses the questions of whether peripheral and central GLP-1 sources constitute separate, linked or redundant systems and whether the brain GLP-1 system consists of disparate sections or is a homogenous entity. This review also explores the implications of the answers to these questions for the use of GLP-1 receptor agonists as anti-obesity drugs. 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: Brain; Eating; Glucagon-Like Peptide 1; Glucagon-Like Peptide-1 Receptor; Humans; Obesity | 2022 |
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 |
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 |
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 |
Glucagon-like peptide-1, a matter of taste?
Understanding of gustatory coding helps to predict, and perhaps even modulate the ingestive decision circuitry, especially when eating behaviour becomes dysfunctional. Preclinical research demonstrated that glucagon like peptide 1 (GLP-1) is locally synthesized in taste bud cells in the tongue and that GLP-1 receptor exists on the gustatory nerves in close proximity to GLP-1 containing taste bud cells. In humans, the tongue has not yet been addressed as clinically relevant target for GLP-1 based therapies. The primary aim of the current review was to elaborate on the role of GLP- 1 in mammalian gustatory system, in particular in the perception of sweet. Secondly, we aimed to explore what modulates gustatory coding and whether the GLP-1 based therapies might be involved in regulation of taste perception. We performed a series of PubMed, Medline and Embase databases systemic searches. The Population-Intervention-Comparison-Outcome (PICO) framework was used to identify interventional studies. Based on the available data, GLP-1 is specifically involved in the perception of sweet. Aging, diabetes and obesity are characterized by diminished taste and sweet perception. Calorie restriction and bariatric surgery are associated with a diminished appreciation of sweet food. GLP-1 receptor agonists (RAs) modulate food preference, yet its modulatory potential in gustatory coding is currently unknown. Future studies should explore whether GLP-1 RAs modulate taste perception to the extent that changes of food preference and consumption ensue. Topics: Animals; Glucagon-Like Peptide 1; Glucagon-Like Peptide-1 Receptor; Humans; Mammals; Obesity; Taste; Taste Buds | 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 |
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 |
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 |
Revisiting the Complexity of GLP-1 Action from Sites of Synthesis to Receptor Activation.
Glucagon-like peptide-1 (GLP-1) is produced in gut endocrine cells and in the brain, and acts through hormonal and neural pathways to regulate islet function, satiety, and gut motility, supporting development of GLP-1 receptor (GLP-1R) agonists for the treatment of diabetes and obesity. Classic notions of GLP-1 acting as a meal-stimulated hormone from the distal gut are challenged by data supporting production of GLP-1 in the endocrine pancreas, and by the importance of brain-derived GLP-1 in the control of neural activity. Moreover, attribution of direct vs indirect actions of GLP-1 is difficult, as many tissue and cellular targets of GLP-1 action do not exhibit robust or detectable GLP-1R expression. Furthermore, reliable detection of the GLP-1R is technically challenging, highly method dependent, and subject to misinterpretation. Here we revisit the actions of GLP-1, scrutinizing key concepts supporting gut vs extra-intestinal GLP-1 synthesis and secretion. We discuss new insights refining cellular localization of GLP-1R expression and integrate recent data to refine our understanding of how and where GLP-1 acts to control inflammation, cardiovascular function, islet hormone secretion, gastric emptying, appetite, and body weight. These findings update our knowledge of cell types and mechanisms linking endogenous vs pharmacological GLP-1 action to activation of the canonical GLP-1R, and the control of metabolic activity in multiple organs. Topics: Glucagon-Like Peptide 1; Glucagon-Like Peptide-1 Receptor; Humans; Obesity | 2021 |
Glucagon-Like Peptide 1 and Taste Perception: From Molecular Mechanisms to Potential Clinical Implications.
Preclinical studies provided some important insights into the action of glucagon-like peptide 1 (GLP-1) in taste perception. This review examines the literature to uncover some molecular mechanisms and connections between GLP-1 and the gustatory coding. Local GLP-1 production in the taste bud cells, the expression of GLP-1 receptor on the adjacent nerves, a functional continuum in the perception of sweet chemicals from the gut to the tongue and an identification of GLP-1 induced signaling pathways in peripheral and central gustatory coding all strongly suggest that GLP-1 is involved in the taste perception, especially sweet. However, the impact of GLP-1 based therapies on gustatory coding in humans remains largely unaddressed. Based on the molecular background we encourage further exploration of the tongue as a new treatment target for GLP-1 receptor agonists in clinical studies. Given that pharmacological manipulation of gustatory coding may represent a new potential strategy against obesity and diabetes, the topic is of utmost clinical relevance. Topics: Animals; Glucagon-Like Peptide 1; Glucagon-Like Peptide-1 Receptor; Humans; Obesity; Signal Transduction; Taste; Taste Buds; Taste Perception | 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 |
Gut Hormones in Health and Obesity: The Upcoming Role of Short Chain Fatty Acids.
We are currently facing an obesity pandemic, with worldwide obesity rates having tripled since 1975. Obesity is one of the main risk factors for the development of non-communicable diseases, which are now the leading cause of death worldwide. This calls for urgent action towards understanding the underlying mechanisms behind the development of obesity as well as developing more effective treatments and interventions. Appetite is carefully regulated in humans via the interaction between the central nervous system and peripheral hormones. This involves a delicate balance in external stimuli, circulating satiating and appetite stimulating hormones, and correct functioning of neuronal signals. Any changes in this equilibrium can lead to an imbalance in energy intake versus expenditure, which often leads to overeating, and potentially weight gain resulting in overweight or obesity. Several lines of research have shown imbalances in gut hormones are found in those who are overweight or obese, which may be contributing to their condition. Therefore, this review examines the evidence for targeting gut hormones in the treatment of obesity by discussing how their dysregulation influences food intake, the potential possibility of altering the circulating levels of these hormones for treating obesity, as well as the role of short chain fatty acids and protein as novel treatments. Topics: Acetic Acid; Animals; Appetite; Appetite Regulation; Butyrates; Central Nervous System; Cholecystokinin; Dipeptides; Energy Intake; Energy Metabolism; Fatty Acids, Volatile; Gastrointestinal Hormones; Gastrointestinal Tract; Ghrelin; Glucagon-Like Peptide 1; Humans; Hyperphagia; Mice; Neuropeptide Y; Obesity; Overweight; Oxyntomodulin; Pancreatic Polypeptide; Propionates; Satiation | 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 therapeutic potential of GLP-1 analogues for stress-related eating and role of GLP-1 in stress, emotion and mood: a review.
Stress and low mood are powerful triggers for compulsive overeating, a maladaptive form of eating leading to negative physical and mental health consequences. Stress-vulnerable individuals, such as people with obesity, are particularly prone to overconsumption of high energy foods and may use it as a coping mechanism for general life stressors. Recent advances in the treatment of obesity and related co-morbidities have focused on the therapeutic potential of anorexigenic gut hormones, such as glucagon-like peptide 1 (GLP-1), which acts both peripherally and centrally to reduce energy intake. Besides its appetite suppressing effect, GLP-1 acts on areas of the brain involved in stress response and emotion regulation. However, the role of GLP-1 in emotion and stress regulation, and whether it is a viable treatment for stress-induced compulsive overeating, has yet to be established. A thorough review of the pre-clinical literature measuring markers of stress, anxiety and mood after GLP-1 exposure points to potential divergent effects based on temporality. Specifically, acute GLP-1 injection consistently stimulates the physiological stress response in rodents whereas long-term exposure indicates anxiolytic and anti-depressive benefits. However, the limited clinical evidence is not as clear cut. While prolonged GLP-1 analogue treatment in people with type 2 diabetes improved measures of mood and general psychological wellbeing, the mechanisms underlying this may be confounded by associated weight loss and improved blood glucose control. There is a paucity of longitudinal clinical literature on mechanistic pathways by which stress influences eating behavior and how centrally-acting gut hormones such as GLP-1, can modify these. (250). Topics: Affect; Animals; Anti-Obesity Agents; Brain-Gut Axis; Clinical Trials, Phase III as Topic; Emotions; Exenatide; Glucagon-Like Peptide 1; Humans; Hyperphagia; Obesity; Stress, Psychological | 2021 |
Future directions in obesity pharmacotherapy.
There is a growing unmet need for more effective treatment of obesity and its complications. While current anti-obesity medications are effective and offer real clinical benefits over diet and lifestyle interventions, they cannot meet the levels of efficacy and reduction of hard endpoint outcomes seen with bariatric surgery. As knowledge on the control of body weight unravels, the complexity of this physiology opens the opportunity to new druggable targets. Currently, gut peptide analogues such as semaglutide, a glucagon like peptide-1 (GLP-1) receptor agonist, and the dual agonist GLP-1 and gastric inhibitory polypeptide (GIP) tirzepatide are the furthest advanced in clinical development and seem likely to meet current regulatory requirements within the next year or so. However, current regulatory requirements are out of step with the efficacy of new compounds and concepts relating to obesity and its complications. Many other drugs in early development will target different pathways of energy balance, raising the possibility of drug combinations to maximise efficacy as for other chronic disease such as hypertension and diabetes. This will allow more complex and personalised guidelines to evolve. Topics: Energy Metabolism; Gastric Inhibitory Polypeptide; Glucagon-Like Peptide 1; Glucagon-Like Peptide-1 Receptor; Humans; Obesity | 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 |
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 |
What Is GLP-1 Really Doing in Obesity?
Glucagon-like peptide-1 (GLP-1) is a gastrointestinal hormone released in response to meal ingestion and enhances insulin secretion from pancreatic β cells. In several human studies, GLP-1 secretory responses to oral glucose load or a meal were decreased in subjects with obesity, glucose intolerance, or diabetes compared with those in healthy subjects. However, the results of meta-analysis and cohort studies do not necessarily support this concept. Results from animal studies are also inconsistent; in multiple studies, GLP-1 secretory responses to a meal were repeatedly higher in diet-induced obese rats than in control rats. Thus, the postprandial GLP-1 response is not necessarily decreased but rather enhanced during obesity development, which is likely to play a protective role against glucose intolerance. Topics: Animals; Glucagon-Like Peptide 1; Glucose Metabolism Disorders; Humans; Obesity; Postprandial Period | 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 |
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 |
A Role for GLP-1 in Treating Hyperphagia and Obesity.
Obesity is a chronic recurring disease whose prevalence has almost tripled over the past 40 years. In individuals with obesity, there is significant increased risk of morbidity and mortality, along with decreased quality of life. Increased obesity prevalence results, at least partly, from the increased global food supply that provides ubiquitous access to tasty, energy-dense foods. These hedonic foods and the nonfood cues that through association become reward predictive cues activate brain appetitive control circuits that drive hyperphagia and weight gain by enhancing food-seeking, motivation, and reward. Behavioral therapy (diet and lifestyle modifications) is the recommended initial treatment for obesity, yet it often fails to achieve meaningful weight loss. Furthermore, those who lose weight regain it over time through biological regulation. The need to effectively treat the pathophysiology of obesity thus centers on biologically based approaches such as bariatric surgery and more recently developed drug therapies. This review highlights neurobiological aspects relevant to obesity causation and treatment by emphasizing the common aspects of the feeding-inhibitory effects of multiple signals. We focus on glucagon like peptide-1 receptor (GLP-1R) signaling as a promising obesity treatment target by discussing the activation of intestinal- and brain-derived GLP-1 and GLP-1R expressing central nervous system circuits resulting from normal eating, bariatric surgery, and GLP-1R agonist drug therapy. Given the increased availability of energy-dense foods and frequent encounters with cues that drive hyperphagia, this review also describes how bariatric surgery and GLP-1R agonist therapies influence food reward and the motivational drive to overeat. Topics: Animals; Bariatric Surgery; Behavior Therapy; Eating; Glucagon-Like Peptide 1; Glucagon-Like Peptide-1 Receptor; Humans; Hyperphagia; Obesity; Receptors, Glucagon; Weight Loss | 2020 |
Intestinal glucagon-like peptide-1 effects on food intake: Physiological relevance and emerging mechanisms.
The gut-brain hormone glucagon-like peptide-1 (GLP-1) has received immense attention over the last couple of decades for its widespread metabolic effects. Notably, intestinal GLP-1 has been recognized as an endogenous satiation signal. Yet, the underlying mechanisms and the pathophysiological relevance of intestinal GLP-1 in obesity remain unclear. This review first recapitulates early findings indicating that intestinal GLP-1 is an endogenous satiation signal, whose eating effects are primarily mediated by vagal afferents. Second, on the basis of recent findings challenging a paracrine action of intestinal GLP-1, a new model for the mediation of GLP-1 effects on eating by two discrete vagal afferent subsets will be proposed. The central mechanisms processing the vagal anorexigenic signals need however to be further delineated. Finally, the idea that intestinal GLP-1 secretion and/or effects on eating are altered in obesity and play a pathophysiological role in the development of obesity will be discussed. In summary, despite the successful therapeutic use of GLP-1 receptor agonists as anti-obesity drugs, the eating effects of intestinal GLP-1 still remain to be elucidated. Specifically, the findings presented here call for a further evaluation of the vago-central neuronal substrates activated by intestinal GLP-1 and for further investigation of its pathophysiological role in obesity. Topics: Animals; Appetite; Brain; Disease Models, Animal; Eating; Gene Expression Regulation; Glucagon-Like Peptide 1; Glucagon-Like Peptide-1 Receptor; Humans; Incretins; Intestinal Mucosa; Liraglutide; Obesity; Satiation; Signal Transduction; Vagus Nerve | 2020 |
Reframing appetitive reinforcement learning and reward valuation as effects mediated by hippocampal-dependent behavioral inhibition.
Traditional theories of neuroeconomics focus on reinforcement learning and reward value. We propose here a novel reframing of reinforcement learning and motivation that includes a hippocampal-dependent regulatory mechanism which balances cue-induced behavioral excitation with behavioral inhibition. This mechanism enables interoceptive cues produced by respective food or drug satiety to antagonize the ability of excitatory food- and drug-related environmental cues to retrieve the memories of food and drug reinforcers, thereby suppressing the power of those cues to evoke appetitive behavior. When the operation of this mechanism is impaired, ability of satiety signals to inhibit appetitive behavior is weakened because the relative balance between inhibition and simple excitation is shifted toward increased retrieval of food and drug memories by environmental cues. In the present paper, we (1) describe the associative processes that constitute this mechanism of hippocampal-dependent behavior inhibition; (2) describe how a prevailing obesity-promoting diet and drugs of abuse produce hippocampal pathophysiologies that can selectively impair this inhibitory function; and (3) propose how glucagon-like peptide 1 (GLP-1), an incretin hormone that is recognized as an important satiety signal, may work to protect the hippocampal-dependent inhibition. Our perspective may add to neuroscientific and neuroeconomic analyses of both overeating and drug abuse by outlining the role of hippocampal-dependent memory processes in the control of both food and drug seeking behaviors. In addition, this view suggests that consideration should be given to diet- and drug induced hippocampal pathophysiologies, as potential novel targets for the treatment of dysregulated energy and drug intake. Topics: Animals; Appetite; Body Weight; Cognition; Cognitive Dysfunction; Cues; Diet, Western; Eating; Feeding Behavior; Female; Glucagon-Like Peptide 1; Hippocampus; Humans; Inhibition, Psychological; Interoception; Liraglutide; Male; Memory; Motivation; Obesity; Reinforcement, Psychology; Reward; Satiation; Substance-Related Disorders | 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 |
GLP-1R agonists for the treatment of obesity: a patent review (2015-present).
Glucagon-like peptide-1 (GLP-1) is an endogenous peptide which is secreted by enteroendocrine L cells, GLP-1 receptor agonists (GLP-1 RAs) can exhibit glucoregulation by stimulating insulin release, promote satiety, delay gastric emptying, and reduce energy intake. Liraglutide is the only GLP-1 RA approved for the treatment of obesity. The phase III clinical study of semaglutide has completed and the result showed significant weight loss effect. GLP-1 RAs have been proven to be safe and effective in clinical trials, they are considered to be promising anti-obesity drugs.. This review provides an overview of recently published patents describing modified GLP-1 RAs, multi-agonists in the treatment or prevention of obesity from January 2015 to April 2020. Moreover, small molecule GLP-1 RAs, recombinant fusion proteins, combination of GLP-1 RAs with other drugs and the preparation of GLP-1 RAs are also covered.. Currently, research on anti-obesity effect of modified GLP-1 RAs has grown significantly, liraglutide accounts for approximately 56% of the global obesity drug market. Long-acting analogues and multifunctional peptides showed good weight loss activity. As more and more clinical trials are carried out, we believe that GLP-1 RAs will occupy an important position in the market of obesity treatment. Topics: Animals; Anti-Obesity Agents; Glucagon-Like Peptide 1; Glucagon-Like Peptide-1 Receptor; Glucagon-Like Peptides; Humans; Liraglutide; Obesity; Patents as Topic; Peptides | 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 |
The early history of GIP 1969-2000: From enterogastrone to major metabolic hormone.
This paper describes the early history of Gastric Inhibitory Polypeptide, better referred to simply as GIP, from its isolation by purification from a crude preparation of CCK-PZ (cholecystokinin/pancreozymin) to its recognition as a key player in the pathogenesis of obesity and other metabolic disorders far removed from the enterogastrone properties by which it was originally identified. Augmentation of glucose mediated insulin release, the incretin effect, was discovered soon after GIP was first isolated and only much later was its important role in the pathogenesis of obesity, through mechanism other than insulin secretion, appreciated. Immunoassay - the only method by which the concentration of GIP was measured in plasma until quite recently - was found to be flawed and to depend upon which specific epitope of the hormone an assay detected. This was especially true if it was an amino-acid sequence specific to porcine rather than human GIP. A further confounder was the discovery that much of the GIP measured by immunoassay was its biological antagonist produced by cleavage of its two N-terminal amino-acids in the circulation by the same dipeptidyl-peptidase as de-activates GLP-1. Potential use of synthetic agonistic and antagonistic GIP analogues in therapeutics was barely alluded to before year 2000. Topics: Cholecystokinin; Epitopes; Gastric Inhibitory Polypeptide; Gastrointestinal Hormones; Glucagon-Like Peptide 1; Glucagon-Like Peptide Receptors; Glucose; Humans; Incretins; Insulin; Obesity; Peptides | 2019 |
Insulin Signaling in Bone Marrow Adipocytes.
The goal of this review is to discuss the role of insulin signaling in bone marrow adipocyte formation, metabolic function, and its contribution to cellular senescence in relation to metabolic bone diseases.. Insulin signaling is an evolutionally conserved signaling pathway that plays a critical role in the regulation of metabolism and longevity. Bone is an insulin-responsive organ that plays a role in whole body energy metabolism. Metabolic disturbances associated with obesity and type 2 diabetes increase a risk of fragility fractures along with increased bone marrow adiposity. In obesity, there is impaired insulin signaling in peripheral tissues leading to insulin resistance. However, insulin signaling is maintained in bone marrow microenvironment leading to hypermetabolic state of bone marrow stromal (skeletal) stem cells associated with accelerated senescence and accumulation of bone marrow adipocytes in obesity. This review summarizes current findings on insulin signaling in bone marrow adipocytes and bone marrow stromal (skeletal) stem cells and its importance for bone and fat metabolism. Moreover, it points out to the existence of differences between bone marrow and peripheral fat metabolism which may be relevant for developing therapeutic strategies for treatment of metabolic bone diseases. Topics: Adipocytes; Adipogenesis; Adipose Tissue; Animals; Bone and Bones; Bone Diseases, Metabolic; Bone Marrow; Bone Marrow Cells; Cell Differentiation; Cellular Senescence; Glucagon-Like Peptide 1; Glucose; Humans; Insulin; Insulin Receptor Substrate Proteins; Insulin Resistance; Insulin-Like Growth Factor Binding Protein 4; Insulin-Like Growth Factor I; Mesenchymal Stem Cells; Obesity; Parathyroid Hormone; Receptor for Advanced Glycation End Products; Receptor, Insulin | 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 |
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 |
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 |
The Role of Glucagon-Like Peptide-1 in Energy Homeostasis.
Energy homeostasis is coordinated by bidirectional communication pathways between the brain and peripheral organs, including adipose tissue, muscle, the pancreas, liver, and gut. Disruption of the integrated chemical, hormonal, and neuronal signals that constitute the gut-brain axis significantly contributes to disorders of metabolism and body weight. Initial studies of glucagon-like peptide-1 (GLP-1), a gut hormone released in response to the ingestion of nutrients, focused on its incretin actions to improve postprandial glucose homeostasis by enhancing meal-induced insulin secretion. However, GLP-1 is also a key player in the gut-brain regulatory axis with multiple effects on appetite and energy metabolism outside of its peripheral glucoregulatory actions. In this review, we explore the function of GLP-1 as a component of the gut-brain axis in the regulation of energy homeostasis, and consider the implications of this role for the development of therapeutic treatment options for obesity. Topics: Adiposity; Animals; Appetite; Brain; Energy Metabolism; Gastrointestinal Microbiome; Gastrointestinal Motility; Glucagon-Like Peptide 1; Glucagon-Like Peptide-1 Receptor; Homeostasis; Humans; Incretins; Intestines; Mice; Obesity; Rats; Vagus Nerve; Weight Loss | 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 |
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 |
GLP-1-based therapies to boost autophagy in cardiometabolic patients: From experimental evidence to clinical trials.
Obesity has many deleterious effects on the cardiovascular system, mediated by changes in insulin sensitivity, dyslipidaemia, oxidative stress and inflammation. Current therapies mainly focus on caloric intake suppression and bariatric surgery, however the efficacy of these approaches remains elusive as most patients regain their body weight within the next 5 years. A better understanding of the pathophysiology of obesity is of paramount importance for the development of new therapeutic strategies to prevent vascular complications. Autophagy has emerged as key self-degrading process responsible for the maintenance of cellular homeostasis. Defects in autophagy homeostasis are implicated in metabolic disorders, including obesity, insulin resistance, diabetes mellitus and atherosclerosis. Most importantly, autophagy regulates animal lifespan. Albeit ample preclinical evidence supports the therapeutic promise of autophagy modulators for the treatment of obesity and metabolic diseases, the clinical efficacy of pharmacological modulation of autophagy remains to be proven. Recent work has shown that GLP-1-based therapeutic approaches may positively affect autophagy in perivascular adipose tissue, thus improving obesity-related endothelial dysfunction. In the present review we discuss current evidence on the role of autophagy in obesity, with a specific focus on DPP-4 inhibitors (DPP-4i) and GLP-1 receptor agonists (GLP-1 RA) as modulators of this process. Experimental evidence on GLP-1-based approaches is critically discussed in light of recent clinical trials with DPP-4i and GLP-1 RA. Topics: Adipose Tissue; Animals; Anti-Obesity Agents; Autophagy; Cardiovascular Diseases; Clinical Trials as Topic; Dipeptidyl-Peptidase IV Inhibitors; Evidence-Based Medicine; Glucagon-Like Peptide 1; Glucagon-Like Peptide-1 Receptor; Humans; Obesity; Risk Factors; Signal Transduction; Treatment Outcome | 2019 |
Nonalcoholic Fatty Liver Disease and Obesity Treatment.
Nonalcoholic fatty liver disease (NAFLD), the most prevalent cause of chronic liver disease worldwide, is strongly associated with obesity and insulin resistance.. Significant weight loss can improve NAFLD and nonalcoholic steatohepatitis (NASH). Diet and exercise that result in a sustained body weight reduction of 7-10% can improve liver fat content, NASH, and fibrosis. Vitamin E can be considered in patients with biopsy-proven NASH without diabetes, though caution must be used in those with prostate cancer. Pioglitazone improves liver histology, including fibrosis, and can be considered in patients with or without diabetes. Glucagon-like peptide-1 (GLP-1) antagonists may be beneficial in NASH, but more studies are needed before they can be recommended. Bariatric surgery, with resultant weight loss, can result in improvement in liver fat and inflammation. NAFLD treatment includes diet and exercise with a target 7-10% weight reduction. Treatment goals include improvements in liver fat content, liver inflammation, and fibrosis. Topics: Bariatric Surgery; Body Weight; Diet; Exercise; Glucagon-Like Peptide 1; Humans; Inflammation; Insulin Resistance; Liver; Liver Cirrhosis; Male; Non-alcoholic Fatty Liver Disease; Obesity; Pioglitazone; Prostatic Neoplasms; Vitamin E; Weight Loss | 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 |
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 |
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 |
Glucagon, GLP-1 and Thermogenesis.
Brown adipose tissue (BAT) thermogenesis is a conserved mechanism to maintain body temperature in mammals. However, since BAT contribution to energy expenditure can represent a relevant modulator of metabolic homeostasis, many studies have focused on the nervous system and endocrine factors that control the activity of this tissue. There is long-established evidence that the counter-regulatory hormone glucagon negatively influences energy balance, enhances satiety, and increases energy expenditure. Despite compelling evidence showing that glucagon has direct action on BAT thermogenesis, recent findings are questioning this conventional attribute of glucagon action. Glucagon like peptide-1 (GLP-1) is an incretin secreted by the intestinal tract which strongly decreases feeding, and, furthermore, improves metabolic parameters associated with obesity and diabetes. Therefore, GLP-1 receptors (GLP-1-R) have emerged as a promising target in the treatment of metabolic disorders. In this short review, we will summarize the latest evidence in this regard, as well as the current therapeutic glucagon- and GLP-1-based approaches to treating obesity. Topics: Adipose Tissue, Brown; Animals; Energy Metabolism; Glucagon; Glucagon-Like Peptide 1; Humans; Molecular Targeted Therapy; Obesity; Thermogenesis | 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 |
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 |
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 |
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 |
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 |
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 |
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 |
Integrated insights into the role of alpha-melanocyte stimulatory hormone in the control of food intake and glycaemia.
Identifying peptide hormones with multipotent actions on both weight and glycaemia can have a significant impact on therapeutic options in the treatment of obesity and diabetes. This has been exemplified by recent advances involving pharmacological exploitation of glucagon-like peptide 1 biology. Herein, we summarise evidence supporting the potential candidacy in this light of alpha-melanocyte stimulatory hormone, an endogenous peptide hormone and a breakdown product of the neuropeptide pro-opiomelanocortin. We reference its well described central actions in the control of food intake and moreover highlight new data pointing to an important role for this peptide hormone in the periphery, in relation to glycaemic control. Topics: alpha-MSH; Body Weight; Diabetes Mellitus; Eating; Glucagon-Like Peptide 1; Humans; Obesity; Pro-Opiomelanocortin | 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 |
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 |
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 |
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 |
Current updates on pharmacological roles of glucagon-like peptide 1 in obesity.
Topics: Animals; Body Weight; Exenatide; Female; Glucagon-Like Peptide 1; Glucagon-Like Peptide-1 Receptor; Glucagon-Like Peptides; Humans; Hyperglycemia; Immunoglobulin Fc Fragments; Insulin; Liraglutide; Male; Obesity; Peptides; Recombinant Fusion Proteins | 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 |
Peptide-based multi-agonists: a new paradigm in metabolic pharmacology.
Obesity and its comorbidities, such as type 2 diabetes, are pressing worldwide health concerns. Available anti-obesity treatments include weight loss pharmacotherapies and bariatric surgery. Whilst surgical interventions typically result in significant and sustained weight loss, available pharmacotherapies are far less effective, typically decreasing body weight by no more than 5-10%. An emerging class of multi-agonist drugs may eventually bridge this gap. This new class of specially tailored drugs hybridizes the amino acid sequences of key metabolic hormones into one single entity with enhanced potency and sustained action. Successful examples of this strategy include multi-agonist drugs targeting the receptors for glucagon-like peptide-1 (GLP-1), glucagon and the glucose-dependent insulinotropic polypeptide (GIP). Due to the simultaneous activity at several metabolically relevant receptors, these multi-agonists offer improved body weight loss and glucose tolerance relative to their constituent monotherapies. Further advancing this concept, chimeras were generated that covalently link nuclear acting hormones such as oestrogen, thyroid hormone (T Topics: Animals; Gastrointestinal Hormones; Glucagon; Glucagon-Like Peptide 1; Humans; Obesity; Peptides | 2018 |
Obesity and addiction: can a complication of surgery help us understand the connection?
Obesity is a multifactorial, chronic disease that has proven difficult to treat. An increased understanding of aetiological mechanisms is critical to the development of more effective obesity prevention and treatment strategies. A growing body of empirical evidence has demonstrated parallels between obesity, overeating and substance abuse, including shared behavioural, psychological and neurophysiological factors implicated in the excessive intake of both food and substances of abuse. Several different lines of research have recently emerged that hold the potential to shed light on the connection between obesity, food reward and addiction, with studies examining changes in alcohol use/misuse after weight loss surgery providing a particularly interesting perspective on these interrelationships. However, these lines of investigation have proceeded in relative isolation, and relevant research findings have yet to be integrated in a synthesized, comprehensive manner. To provide an opportunity to achieve such a synthesis, a scientific symposium was convened at the Radcliffe Institute in Cambridge, Massachusetts. Invited participants were researchers working in diverse domains related to the intersection between obesity and addiction. Extensive discussion was generated suggesting novel research directions. In this article, we summarize and synthesize the symposium participants' ongoing research in this area, incorporating additional relevant research holding potential clues regarding the connections between obesity, weight loss surgery and addiction. Topics: Alcohol Drinking; Alcoholism; Animals; Bariatric Surgery; Behavior, Addictive; Ethanol; Gastric Bypass; Glucagon-Like Peptide 1; Humans; Hyperphagia; Obesity; Peptide YY; Reward; Weight Loss | 2017 |
Glucagon-like peptide 1: A potential anti-inflammatory pathway in obesity-related asthma.
Alterations in arginine metabolism and accelerated formation of advanced glycation end-products (AGEs), crucial mechanisms in obesity-related asthma, can be modulated by glucagon-like peptide 1 (GLP-1). l-arginine dysregulation in obesity promotes inflammation and bronchoconstriction. Prolonged hyperglycemia, dyslipidemia, and oxidative stress leads to production of AGEs, that bind to their receptor (RAGE) further potentiating inflammation. By binding to its widely distributed receptor, GLP-1 blunts the effects of RAGE activation and arginine dysregulation. The GLP-1 pathway, while comprehensively studied in the endocrine and cardiovascular literature, is under-recognized in pulmonary research. Insights into GLP-1 and the lung may lead to novel treatments for obesity-related asthma. Topics: Animals; Arginine; Asthma; Glucagon-Like Peptide 1; Glycation End Products, Advanced; Humans; Inflammation; Lung; Obesity; Receptor for Advanced Glycation End Products | 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 |
Central Modulation of Energy Homeostasis and Cognitive Performance After Bariatric Surgery.
In moderately or morbidly obese patients, bariatric surgery has been proven to be an effective therapeutic approach to control body weight and comorbidities. Surgery-mediated modulation of brain function via modified postoperative secretion of gut peptides and vagal nerve stimulation was identified as an underlying mechanism in weight loss and improvement of weight-related diseases. Increased basal and postprandial plasma levels of gastrointestinal hormones like glucagon-like peptide 1 and peptide YY that act on specific areas of the hypothalamus to reduce food intake, either directly or mediated by the vagus nerve, are observed after surgery while suppression of meal-induced ghrelin release is increased. Hormones released from the adipose tissue like leptin and adiponectin are also affected and leptin plasma levels are reduced in treated patients. Besides homeostatic control of body weight, surgery also changes hedonistic behavior in regard to food intake and cognitive performance involving the limbic system and prefrontal areas. Topics: Adiponectin; Bariatric Surgery; Brain; Cognition; Eating; Energy Metabolism; Feeding Behavior; Ghrelin; Glucagon-Like Peptide 1; Homeostasis; Humans; Hypothalamus; Leptin; Limbic System; Obesity; Peptide YY; Prefrontal Cortex; Vagus Nerve | 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 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 |
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 |
Plasticity of gastrointestinal vagal afferent satiety signals.
The vagal link between the gastrointestinal tract and the central nervous system (CNS) has numerous vital functions for maintaining homeostasis. The regulation of energy balance is one which is attracting more and more attention due to the potential for exploiting peripheral hormonal targets as treatments for conditions such as obesity. While physiologically, this system is well tuned and demonstrated to be effective in the regulation of both local function and promoting/terminating food intake the neural connection represents a susceptible pathway for disruption in various disease states. Numerous studies have revealed that obesity in particularly is associated with an array of modifications in vagal afferent function from changes in expression of signaling molecules to altered activation mechanics. In general, these changes in vagal afferent function in obesity further promote food intake instead of the more desirable reduction in food intake. It is essential to gain a comprehensive understanding of the mechanisms responsible for these detrimental effects before we can establish more effective pharmacotherapies or lifestyle strategies for the treatment of obesity and the maintenance of weight loss. Topics: Animals; Cholecystokinin; Dipeptides; Eating; Gastrointestinal Tract; Ghrelin; Glucagon-Like Peptide 1; Humans; Leptin; Microbiota; Neuronal Plasticity; Obesity; Satiation; Signal Transduction; Vagus Nerve | 2017 |
Mitochondrial Adaptation in Nonalcoholic Fatty Liver Disease: Novel Mechanisms and Treatment Strategies.
Nonalcoholic fatty liver disease (NAFLD) is prevalent in patients with obesity or type 2 diabetes. Nonalcoholic steatohepatitis (NASH), encompassing steatosis with inflammation, hepatocyte injury, and fibrosis, predisposes to cirrhosis, hepatocellular carcinoma, and even cardiovascular disease. In rodent models and humans with NAFLD/NASH, maladaptation of mitochondrial oxidative flux is a central feature of simple steatosis to NASH transition. Induction of hepatic tricarboxylic acid cycle closely mirrors the severity of oxidative stress and inflammation in NASH. Reactive oxygen species generation and inflammation are driven by upregulated, but inefficient oxidative flux and accumulating lipotoxic intermediates. Successful therapies for NASH (weight loss alone or with incretin therapy, or pioglitazone) likely attenuate mitochondrial oxidative flux and halt hepatocellular injury. Agents targeting mitochondrial dysfunction may provide a novel treatment strategy for NAFLD. Topics: Animals; Fatty Liver; Glucagon-Like Peptide 1; Humans; Mitochondria; Non-alcoholic Fatty Liver Disease; Obesity; Pioglitazone; Thiazolidinediones | 2017 |
Glucagon-Like Peptide-1 (GLP-1) Receptor Agonists in the Treatment of Obese Women with Polycystic Ovary Syndrome.
Polycystic ovary syndrome (PCOS) is the most common endocrine disorder in females and is often associated with a number of cardiometabolic disorders such as central obesity, dyslipidaemia, hypertension, insulin resistance, hyperinsulinaemia, glucose intolerance and type 2 diabetes mellitus (T2DM). Glucagon-like peptide-1 (GLP-1), a gut hormone secreted after a meal, enhances glucosestimulated insulin secretion and additionally suppresses appetite and gastric motility. Most studies found impaired GLP-1 kinetics in obese individuals, whereas small studies in PCOS reported reduced, normal or even elevated GLP-1 levels. Apart from their efficacy in patients with T2DM, some GLP-1 receptor agonists (GLP-1 RAs) have been successfully tested in terms of both efficiency and safety in obese individuals without diabetes and liraglutide 3 mg once daily has been approved as an antiobesity drug in the USA and the European Union. Recently, some small trials of short duration using GLP-1 RAs as monotherapy or combined with metformin in obese PCOS women showed positive results regarding weight reduction and a decrease in testosterone levels but without significant effects on insulin levels, insulin sensitivity and menstrual patterns. Longer term studies with more patients and higher doses of liraglutide (as this drug is already approved for obese individuals) are required to determine the precise indications of GLP-1 RAs in PCOS and to evaluate safety issues. Topics: Animals; Anti-Obesity Agents; Biomarkers; Female; Glucagon-Like Peptide 1; Glucagon-Like Peptide-1 Receptor; Humans; Incretins; Kinetics; Liraglutide; Obesity; Polycystic Ovary Syndrome; Signal Transduction; Treatment Outcome | 2017 |
Ghrelin, CCK, GLP-1, and PYY(3-36): Secretory Controls and Physiological Roles in Eating and Glycemia in Health, Obesity, and After RYGB.
The efficacy of Roux-en-Y gastric-bypass (RYGB) and other bariatric surgeries in the management of obesity and type 2 diabetes mellitus and novel developments in gastrointestinal (GI) endocrinology have renewed interest in the roles of GI hormones in the control of eating, meal-related glycemia, and obesity. Here we review the nutrient-sensing mechanisms that control the secretion of four of these hormones, ghrelin, cholecystokinin (CCK), glucagon-like peptide-1 (GLP-1), and peptide tyrosine tyrosine [PYY(3-36)], and their contributions to the controls of GI motor function, food intake, and meal-related increases in glycemia in healthy-weight and obese persons, as well as in RYGB patients. Their physiological roles as classical endocrine and as locally acting signals are discussed. Gastric emptying, the detection of specific digestive products by small intestinal enteroendocrine cells, and synergistic interactions among different GI loci all contribute to the secretion of ghrelin, CCK, GLP-1, and PYY(3-36). While CCK has been fully established as an endogenous endocrine control of eating in healthy-weight persons, the roles of all four hormones in eating in obese persons and following RYGB are uncertain. Similarly, only GLP-1 clearly contributes to the endocrine control of meal-related glycemia. It is likely that local signaling is involved in these hormones' actions, but methods to determine the physiological status of local signaling effects are lacking. Further research and fresh approaches are required to better understand ghrelin, CCK, GLP-1, and PYY(3-36) physiology; their roles in obesity and bariatric surgery; and their therapeutic potentials. Topics: Blood Glucose; Cholecystokinin; Eating; Gastric Bypass; Ghrelin; Glucagon-Like Peptide 1; Humans; Obesity; Peptide Fragments; Peptide YY | 2017 |
Scaling it down: new in vitro tools to get the balance right.
Treatments for diabetes and obesity based on enteroendocrine hormones are a focus of research interest, partly due to the successes of glucagon-like peptide-1 (GLP-1) mimetic peptides in the treatment of diabetes and the correlation of altered enteroendocrine profiles with the positive metabolic outcomes of gastric bypass surgery. It is thought that simultaneous stimulation of more than one receptor might mimic the superior efficacy of the latter and dual or triple-agonist peptides are under investigation. An important step in developing multiple agonists is to establish the relative pharmacological potency and efficacy of new molecules at its different target receptors, and to optimise the balance of activities to achieve the desired treatment outcome. In a recent issue of the Biochemical Journal, Naylor et al. described how they used CRISPR technology to modulate endogenous receptor density in insulinoma cells to get the balance right for a dual incretin peptide engaging both GLP-1- and glucose-dependent insulinotropic polypeptide-receptors. Topics: Animals; Cell Line, Tumor; Clustered Regularly Interspaced Short Palindromic Repeats; Diabetes Mellitus; Glucagon-Like Peptide 1; Humans; Obesity; Peptidomimetics | 2017 |
How the gut affects bone metabolism.
Topics: Animals; Blood Glucose; Bone and Bones; Energy Metabolism; Gastrins; Gastrointestinal Hormones; Gastrointestinal Microbiome; Ghrelin; Glucagon-Like Peptide 1; Humans; Insulin; Mice; Obesity; Sensitivity and Specificity | 2017 |
Impact of Bariatric Surgery on Metabolic and Gut Microbiota Profile: a Systematic Review and Meta-analysis.
We aim to review the available literature on obese patients treated with bariatric procedures, in order to assess their effect on the metabolic and gut microbiota profiles. A systematic literature search was performed in PubMed, Cochrane library, and Scopus databases, in accordance with the PRISMA guidelines. Twenty-two studies (562 patients) met the inclusion criteria. This study points to significant amelioration of postoperative levels of glucose, insulin, triglycerides, total cholesterol, LDL, HDL, HOMA-IR, food intake, and diabetes remission. Branched-chain amino acids (BCAAs) decreased, while trimethylamine-n-oxide (TMAO); glucagon-like peptide 1, 2 (GLP-1, GLP-2); and peptide YY (PYY) increased postoperatively. Postoperative gut microbiota was similar to that of lean and less obese objects. Well-designed randomized trials are necessary to further assess the host metabolic-microbial cross-talk after bariatric procedures. Topics: Adult; Amino Acids, Branched-Chain; Bariatric Surgery; Blood Glucose; Female; Gastrointestinal Microbiome; Glucagon-Like Peptide 1; Humans; Insulin; Male; Middle Aged; Obesity; Young Adult | 2017 |
Obesity-related, metabolic asthma: a new role for glucagon-like peptide 1 agonists.
Topics: Asthma; Glucagon-Like Peptide 1; Humans; Metabolic Syndrome; Obesity | 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 |
Gastrointestinal traits: individualizing therapy for obesity with drugs and devices.
The aims of this article were to review the discrepancy between numbers of people requiring weight loss treatment and results and to assess the potential effects of pharmacologic treatments (recently approved for obesity) and endoscopically deployed devices on quantitative GI traits in development for obesity treatment.. We conducted a review of relevant literature to achieve our objectives.. The 2013 guidelines increased the number of adults recommended for weight loss treatment by 20.9% (116.0 million to 140.2 million). There is an imbalance between efficacy and costs of commercial weight loss programs and drug therapy (average weight loss about 5 kg). The number of bariatric procedures performed in the United States has doubled in the past decade. The efficacy of bariatric surgery is attributed to reduction in the volume of the stomach, nutrient malabsorption with some types of surgery, increased postprandial incretin responses, and activation of farnesoid X receptor mechanisms. These GI and behavioral traits identify sub-phenotypes of obesity, based on recent research.. The mechanisms or traits targeted by drug and device treatments include centrally mediated alterations of appetite or satiation, diversion of nutrients, and alteration of stomach capacity, gastric emptying, or incretin hormones. Future treatment may be individualized based on quantitative GI and behavioral traits measured in obese patients. Topics: Anti-Obesity Agents; Bariatric Surgery; Combined Modality Therapy; Depression; Endoscopy, Gastrointestinal; Equipment and Supplies; Feeding Behavior; Gastric Balloon; Gastric Bypass; Gastric Emptying; Gastroplasty; Glucagon-Like Peptide 1; Humans; Hypothalamus; Obesity; Organ Size; Peptide YY; Precision Medicine; Principal Component Analysis; Satiation; Stomach; Treatment Outcome; Weight Loss | 2016 |
Intestinal GLP-1 and satiation: from man to rodents and back.
In response to luminal food stimuli during meals, enteroendocrine cells release gastrointestinal (GI) peptides that have long been known to control secretory and motor functions of the gut, pancreas and liver. Glucagon-like peptide-1 (GLP-1) has emerged as one of the most important GI peptides because of a combination of functions not previously ascribed to any other molecule. GLP-1 potentiates glucose-induced insulin secretion, suppresses glucagon release, slows gastric emptying and may serve as a satiation signal, although the physiological status of the latter function has not been fully established yet. Here we review the available evidence for intestinal GLP-1 to fulfill a number of established empirical criteria for assessing whether a hormone inhibits eating by eliciting physiological satiation in man and rodents. Topics: Animals; Appetite; Eating; Gastrointestinal Motility; Glucagon-Like Peptide 1; Glucagon-Like Peptide-1 Receptor; Humans; Mice; Obesity; Rats; Satiation | 2016 |
Potential therapeutic value of TRPV1 and TRPA1 in diabetes mellitus and obesity.
Diabetes mellitus and obesity, which is a major risk factor in the development of type 2 diabetes mellitus, have reached epidemic proportions worldwide including the USA. The current statistics and forecasts, both short- and long-term, are alarming and predict severe problems in the near future. Therefore, there is a race for developing new compounds, discovering new receptors, or finding alternative solutions to prevent and/or treat the symptoms and complications related to obesity and diabetes mellitus. It is well demonstrated that members of the transient receptor potential (TRP) superfamily play a crucial role in a variety of biological functions both in health and disease. In the recent years, transient receptor potential vanilloid type 1 (TRPV1) and transient receptor potential ankyrin 1 (TRPA1) were shown to have beneficial effects on whole body metabolism including glucose homeostasis. TRPV1 and TRPA1 have been associated with control of weight, pancreatic function, hormone secretion, thermogenesis, and neuronal function, which suggest a potential therapeutic value of these channels. This review summarizes recent findings regarding TRPV1 and TRPA1 in association with whole body metabolism with emphasis on obese and diabetic conditions. Topics: Adipose Tissue; Animals; Autonomic Nervous System; Calcium Channels; Diabetes Mellitus; Diet Therapy; Dietary Supplements; Ghrelin; Glucagon-Like Peptide 1; Humans; Ligands; Nerve Tissue Proteins; Obesity; Pancreas; Transient Receptor Potential Channels; TRPA1 Cation Channel; TRPV Cation Channels | 2016 |
Contribution of Macrophage Polarization to Metabolic Diseases.
Macrophage activation is one of the major immunological events in the pathogenesis of various diseases. Recent studies have disclosed that complicated mechanisms are involved in macrophage activation and polarization, and many published research articles have been based on the M1/M2 polarization concept. It is considered that M1- and M2-like macrophages are associated with T helper (Th)1-type and Th2-type immune responses, respectively, via several immune mediators. In this article, we summarize the correlations between macrophage polarization and metabolic disorders in both humans and mice and discuss the contribution of macrophage polarization to the pathogenic process of metabolic diseases. Topics: Animals; Atherosclerosis; Gene Expression Profiling; Gene Expression Regulation; Glucagon-Like Peptide 1; Humans; Liver Diseases; Macrophage Activation; Macrophages; Metabolic Diseases; Mice; Obesity; Oncostatin M; Phenotype; Th1 Cells; Th2 Cells | 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 |
Regulation of energy balance by a gut-brain axis and involvement of the gut microbiota.
Despite significant progress in understanding the homeostatic regulation of energy balance, successful therapeutic options for curbing obesity remain elusive. One potential target for the treatment of obesity is via manipulation of the gut-brain axis, a complex bidirectional communication system that is crucial in maintaining energy homeostasis. Indeed, ingested nutrients induce secretion of gut peptides that act either via paracrine signaling through vagal and non-vagal neuronal relays, or in an endocrine fashion via entry into circulation, to ultimately signal to the central nervous system where appropriate responses are generated. We review here the current hypotheses of nutrient sensing mechanisms of enteroendocrine cells, including the release of gut peptides, mainly cholecystokinin, glucagon-like peptide-1, and peptide YY, and subsequent gut-to-brain signaling pathways promoting a reduction of food intake and an increase in energy expenditure. Furthermore, this review highlights recent research suggesting this energy regulating gut-brain axis can be influenced by gut microbiota, potentially contributing to the development of obesity. Topics: Animals; Appetite Regulation; Brain; Cholecystokinin; Energy Metabolism; Gastrointestinal Microbiome; Gastrointestinal Tract; Glucagon-Like Peptide 1; Humans; Obesity; Peptide YY; Signal Transduction | 2016 |
Male fertility and obesity: are ghrelin, leptin and glucagon-like peptide-1 pharmacologically relevant?
Obesity is rising to unprecedented numbers, affecting a growing number of children, adolescents and young adult men. These individuals face innumerous health problems, including subfertility or even infertility. Overweight and obese men present severe alterations in their body composition and hormonal profile, particularly in ghrelin, leptin and glucagon-like peptide-1 (GLP-1) levels. It is well known that male reproductive health is under the control of the individual's nutritional status and also of a tight network of regulatory signals, particularly hormonal signaling. However, few studies have been focused on the effects of ghrelin, leptin and GLP-1 in male reproduction and how energy homeostasis and male reproductive function are linked. These hormones regulate body glucose homeostasis and several studies suggest that they can serve as targets for anti-obesity drugs. In recent years, our understanding of the mechanisms of action of these hormones has grown significantly. Curiously, their effect on male reproductive potential, that is highly dependent of the metabolic cooperation established between testicular cells, remains a matter of debate. Herein, we review general concepts of male fertility and obesity, with a special focus on the effects of ghrelin, leptin and GLP-1 on male reproductive health. We also discuss the possible pharmacological relevance of these hormones to counteract the fertility problems that overweight and obese men face. Topics: Adolescent; Child; Fertility; Ghrelin; Glucagon-Like Peptide 1; Humans; Infertility, Male; Leptin; Male; Obesity; Overweight; Young Adult | 2016 |
Obesity: An overview of possible role(s) of gut hormones, lipid sensing and gut microbiota.
Obesity is one of the major challenges for public health in 21st century, with 1.9 billion people being considered as overweight and 600 million as obese. There are certain diseases such as type 2 diabetes, hypertension, cardiovascular disease, and several forms of cancer which were found to be associated with obesity. Therefore, understanding the key molecular mechanisms involved in the pathogenesis of obesity could be beneficial for the development of a therapeutic approach. Hormones such as ghrelin, glucagon like peptide 1 (GLP-1) peptide YY (PYY), pancreatic polypeptide (PP), cholecystokinin (CCK) secreted by an endocrine organ gut, have an intense impact on energy balance and maintenance of homeostasis by inducing satiety and meal termination. Glucose and energy homeostasis are also affected by lipid sensing in which different organs respond in different ways. However, there is one common mechanism i.e. formation of esterified lipids (long chain fatty acyl CoAs) and the activation of protein kinase C δ (PKC δ) involved in all these organs. The possible role of gut microbiota and obesity has been addressed by several researchers in recent years, indicating the possible therapeutic approach toward the management of obesity by the introduction of an external living system such as a probiotic. The proposed mechanism behind this activity is attributed by metabolites produced by gut microbial organisms. Thus, this review summarizes the role of various physiological factors such as gut hormone and lipid sensing involved in various tissues and organ and most important by the role of gut microbiota in weight management. Topics: Adipose Tissue; Brain; Cholecystokinin; Cholesterol, VLDL; Gastrointestinal Hormones; Gastrointestinal Microbiome; Glucagon-Like Peptide 1; Humans; Insulin Resistance; Lipid Metabolism; Obesity; PPAR gamma | 2016 |
GLP-1 and Amylin in the Treatment of Obesity.
For decades, extensive research has aimed to clarify the role of pancreas and gut-derived peptide hormones in the regulation of glucose homeostasis and feeding behavior. Among these are the beta-cell hormone amylin and the intestinal L cell hormone glucagon-like peptide-1 (GLP-1). They exhibit distinct and yet several similar physiological actions including suppression of food intake, postprandial glucagon secretion, and gastric emptying-altogether lowering plasma glucose and body weight. These actions have been clinically exploited by the development of amylin and GLP-1 hormone analogs now used for treatment of diabetes and obesity. This review will outline the physiology and pharmacological potential of amylin and GLP-1, respectively, and focus on innovative peptide drug development leading to drugs acting on two or more distinct receptors, such as an amylin and GLP-1 peptide hybrid, potentially producing a more effective treatment strategy to combat the rapidly increasing global obesity. Topics: Animals; Diabetes Mellitus; Eating; Glucagon-Like Peptide 1; Humans; Insulin-Secreting Cells; Islet Amyloid Polypeptide; Obesity | 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 |
Post-Gastric Bypass Hypoglycemia.
Obesity is a major public health problem worldwide. Obesity-related illnesses, such as coronary heart disease, type 2 diabetes, hypertension, dyslipidemia, stroke, sleep apnea, and several forms of cancer (endometrial, breast, and colon), contribute to a significant number of deaths in the USA. Bariatric surgery, including the Roux-en-Y gastric bypass (RYGB) procedure, has demonstrated significant improvements in obesity and obesity-related co-morbidities and is becoming more popular as the number of obese individuals rises. Despite the reported benefits of bariatric surgery, there are potential complications that physicians need to be aware of as the number of patients undergoing these procedures continues to increase. One challenging and potentially life-threatening complication that to date is not well understood is post-RYGB surgery hypoglycemia (PGBH). In this review, we will present the definition, historical perspective, diagnostic approach, currently available treatment options, and anecdotal assessment and treatment algorithm for this disorder. Topics: Gastric Bypass; Glucagon-Like Peptide 1; Humans; Hypertension; Hypoglycemia; Incretins; Obesity | 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 |
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 |
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 |
Glucagon-like peptide-1 and cholecystokinin production and signaling in the pancreatic islet as an adaptive response to obesity.
Precise control of blood glucose is dependent on adequate β-cell mass and function. Thus, reductions in β-cell mass and function lead to insufficient insulin production to meet demand, and result in diabetes. Recent evidence suggests that paracrine signaling in the islet might be important in obesity, and disruption of this signaling could play a role in the pathogenesis of diabetes. For example, we recently discovered a novel islet incretin axis where glucagon-like peptide-1 regulates β-cell production of another classic gut hormone, cholecystokinin. This axis is stimulated by obesity, and plays a role in enhancing β-cell survival. In the present review, we place our observations in the wider context of the literature on incretin regulation in the islet, and discuss the potential for therapeutic targeting of these pathways. Topics: Animals; Cholecystokinin; Glucagon-Like Peptide 1; Humans; Incretins; Islets of Langerhans; Obesity; Paracrine Communication | 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 |
Stressing diabetes? The hidden links between insulinotropic peptides and the HPA axis.
Diabetes mellitus exerts metabolic stress on cells and it provokes a chronic increase in the long-term activity of the hypothalamus-pituitary-adrenocortical (HPA) axis, perhaps thereby contributing to insulin resistance. GLP-1 receptor (GLP-1R) agonists are pleiotropic hormones that not only affect glycaemic and metabolic control, but they also produce many other effects including activation of the HPA axis. In fact, several of the most relevant effects of GLP-1 might involve, at least in part, the modulation of the HPA axis. Thus, the anorectic activity of GLP-1 could be mediated by increasing CRF at the hypothalamic level, while its lipolytic effects could imply a local increase in glucocorticoids and glucocorticoid receptor (GC-R) expression in adipose tissue. Indeed, the potent activation of the HPA axis by GLP-1R agonists occurs within the range of therapeutic doses and with a short latency. Interestingly, the interactions of GLP-1 with the HPA axis may underlie most of the effects of GLP-1 on food intake control, glycaemic metabolism, adipose tissue biology and the responses to stress. Moreover, such activity has been observed in animal models (mice and rats), as well as in normal humans and in type I or type II diabetic patients. Accordingly, better understanding of how GLP-1R agonists modulate the activity of the HPA axis in diabetic subjects, especially obese individuals, will be crucial to design new and more efficient therapies for these patients. Topics: Adrenal Cortex; Animals; Corticotropin-Releasing Hormone; Diabetes Mellitus; Female; Fetal Development; Glucagon-Like Peptide 1; Glucagon-Like Peptide-1 Receptor; Glucocorticoids; Humans; Hypothalamo-Hypophyseal System; Incretins; Insulin Resistance; Obesity; Pregnancy; Prenatal Exposure Delayed Effects; Stress, Physiological | 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 |
Energy balance, body composition, sedentariness and appetite regulation: pathways to obesity.
Energy balance is not a simple algebraic sum of energy expenditure and energy intake as often depicted in communications. Energy balance is a dynamic process and there exist reciprocal effects between food intake and energy expenditure. An important distinction is that of metabolic and behavioural components of energy expenditure. These components not only contribute to the energy budget directly, but also by influencing the energy intake side of the equation. It has recently been demonstrated that resting metabolic rate (RMR) is a potential driver of energy intake, and evidence is accumulating on the influence of physical activity (behavioural energy expenditure) on mechanisms of satiety and appetite control. These effects are associated with changes in leptin and insulin sensitivity, and in the plasma levels of gastrointestinal (GI) peptides such as glucagon-like peptide-1 (GLP-1), ghrelin and cholecystokinin (CCK). The influence of fat-free mass on energy expenditure and as a driver of energy intake directs attention to molecules emanating from skeletal tissue as potential appetite signals. Sedentariness (physical inactivity) is positively associated with adiposity and is proposed to be a source of overconsumption and appetite dysregulation. The molecular signals underlying these effects are not known but represent a target for research. Topics: Animals; Appetite Regulation; Body Composition; Energy Metabolism; Ghrelin; Glucagon-Like Peptide 1; Humans; Leptin; Obesity | 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 |
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 |
Weight loss effect of glucagon-like peptide-1 mimetics on obese/overweight adults without diabetes: A systematic review and meta-analysis of randomized controlled trials.
Glucagon-like peptide-1 receptor agonists (GLP-1RAs) benefit weight maintenance for diabetic patients. We performed a systematic review to evaluate its weight loss effect on obese/overweight patients without diabetes in randomized controlled trials (RCTs).. Literature updated to May 5, 2014 from Cochrane Library, MEDLINE, EMBASE and reference lists from relevant articles were identified. RCTs with GLP-1 mimetics treating obese/overweight adults without diabetes for at least 12 weeks were assessed. Studies lacking primary measurements were excluded. Three authors extracted data independently. Either fixed-effect or random-effect models were used to calculate weighted mean differences (WMDs), combined relative risks (RR) and 95% confidence interval (CI) in meta-analyses. Intertrial heterogeneity across studies was examined by I(2) and Q statistics.. A total of 1345 individuals retrieved from eight studies were involved and all included trials were of mild-to-moderate bias risks. Participants in GLP-1RA groups achieved a larger weight loss than those in control groups (-2.85 kg, 95%CI -3.55 to -2.14), and liraglutide may work in a dose-dependent fashion. GLP-1RAs also reduced body mass index (BMI) and waist circumferences (WC) and benefited systolic blood pressure and triglyceride regulation. But GLP-1RAs were associated with increased nausea and vomiting events.. GLP-1 mimetics induce a weight loss in addition to BMI and WC reduction in obese/overweight adults without diabetes. Further long-term randomized trials and basic studies are required to investigate the mechanisms. Topics: Adult; Biomimetics; Glucagon-Like Peptide 1; Humans; Hypoglycemic Agents; Obesity; Overweight; Randomized Controlled Trials as Topic; Receptors, Glucagon; Weight Loss | 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 |
Obesity and polycystic ovary syndrome.
Obesity is now a major international health concern. It is increasingly common in young women with reproductive, metabolic and psychological health impacts. Reproductive health impacts are often poorly appreciated and include polycystic ovary syndrome (PCOS), infertility and pregnancy complications. PCOS is the most common endocrine condition in women and is underpinned by hormonal disturbances including insulin resistance and hyperandrogenism. Obesity exacerbates hormonal and clinical features of PCOS and women with PCOS appear at higher risk of obesity, with multiple underlying mechanisms linking the conditions. Lifestyle intervention is first line in management of PCOS to both prevent weight gain and induce weight loss; however improved engagement and sustainability remain challenges with the need for more research. Medications like metformin, orlistat, GLP1 agonists and bariatric surgery have been used with the need for large scale randomised clinical trials to define their roles. Topics: Adipokines; Bariatric Surgery; Combined Modality Therapy; Comorbidity; Diet, Reducing; Exercise Therapy; Female; Glucagon-Like Peptide 1; Gonadal Steroid Hormones; Humans; Hyperandrogenism; Inflammation; Insulin Resistance; Lactones; Life Style; Metformin; Models, Biological; Motivation; Obesity; Obesity, Abdominal; Orlistat; Polycystic Ovary Syndrome; Prevalence; Sympathetic Nervous System; Weight Loss | 2015 |
Obesity and type 1 diabetes mellitus management.
Patients with type 1 diabetes mellitus (T1DM) traditionally had a low body mass index and microangiopathic complications were common. The Diabetes Control and Complications Trial, published in 1993, demonstrated that therapy aimed at maintaining HbA1c levels as close to normal as feasible reduced the incidence of microangiopathy. Since then, the use of intensive insulin therapy to optimise metabolic control became generalised, with two main side effects: a higher rate of severe hypoglycaemia and increased weight gain. Approximately 50% of patients with T1DM are currently obese or overweight, which reduces or nullifies the benefits of good metabolic control, and which has other negative consequences; therefore, strategies to achieve weight control in patients with T1DM are necessary. At present, treatment with GLP-1 and SGLT-2 inhibitors has yielded promising short-term results that need to be confirmed in studies with larger numbers of patients and long-term follow-up. It is possible that, in coming years, the applicability of bariatric surgery in obese patients with T1DM will be similar to that of the general population or T2DM. Topics: Adolescent; Adult; Bariatric Surgery; Body Mass Index; Depression; Diabetes Complications; Diabetes Mellitus, Type 1; Female; Glucagon-Like Peptide 1; Glycated Hemoglobin; Hirsutism; Humans; Hypoglycemic Agents; Hypogonadism; Insulin; Life Style; Male; Metabolic Syndrome; Obesity; Osteoporosis; Overweight; Polycystic Ovary Syndrome; Sodium-Glucose Transporter 2; Sodium-Glucose Transporter 2 Inhibitors; Weight Gain | 2015 |
GLP-1: a mediator of the beneficial metabolic effects of bariatric surgery?
There has been increasing interest in the role that gut hormones may play in contributing to the physiological changes produced by certain bariatric procedures, such as Roux-en-Y gastric bypass and sleeve gastrectomy. Here, we review the evidence implicating one such gut hormone, glucagon-like peptide-1, as a mediator of the metabolic benefits of these two procedures. Topics: Animals; Bariatric Surgery; Gastrectomy; Gastric Bypass; Glucagon-Like Peptide 1; Humans; Obesity; Treatment Outcome | 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 |
Safety and tolerability of medications approved for chronic weight management.
In 2014 we have 4 new weight loss medications and one older medication with very different mechanisms of action – all approved for chronic weight management. Each medication has its own unique risk profile that makes patient selection important. Knowledge of the contraindications and safety issues can guide physicians to the most appropriate choice for a particular patient. Obesity medicine is entering a new era where our available options for prescribing have been very well studied. There should be no surprises, because bupropion, naltrexone, phentermine, topiramate and liraglutide have been prescribed for many years in millions of patients and lorcaserin has high specificity for a single receptor subtype. The FDA demanded very detailed risk-oriented studies to have these medications approved. In addition, the FDA has established REMS programs or risk management strategies to help ensure that the patients do not receive inappropriate medications. These medications were approved by the US FDA after very thorough testing. The decision to approve these medications was based on the benefits out-weighing the risks. Thus, if following the appropriate guidelines according to package labels, the practitioner can feel safe in prescribing these medications. Topics: Anti-Obesity Agents; Benzazepines; Bupropion; Delayed-Action Preparations; Drug-Related Side Effects and Adverse Reactions; Drugs, Investigational; Fructose; Glucagon-Like Peptide 1; Humans; Liraglutide; Naltrexone; Obesity; Phentermine; Topiramate; United States; United States Food and Drug Administration; Weight Loss | 2015 |
Incretin-based therapies for obesity treatment.
Currently, obesity and its associated complications are considered major public health problems worldwide. Because the causes are multifactorial and complex, different treatment methods are used, which include diet and exercise, as well as the use of drugs, although they can have adverse side effects. A new target for the treatment of obesity may be the incretin system, which consists of hormones that seem to contribute to weight loss. In this sense, some studies have shown a relationship between weight loss and drugs related to incretin system, including glucagon-like peptide-1 (GLP-1) agonists and dipeptidyl peptidase-4 (DPP-4) inhibitors. The objective of this review is to summarize the association between the incretin system and obesity treatment. Topics: Animals; Anti-Obesity Agents; Dipeptidyl-Peptidase IV Inhibitors; Glucagon-Like Peptide 1; Humans; Incretins; Obesity; Receptors, Gastrointestinal Hormone | 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 |
[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 |
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 |
Liraglutide: A New Option for the Treatment of Obesity.
Obesity continues to pose a major public health risk to the United States and across the world, with an estimated one-third of adult Americans being defined as obese. Obesity treatment guidelines recommend the use of pharmacologic therapy in adults who have a body mass index (BMI) of 30 kg/m(2) or higher or in patients with a BMI of 27 kg/m(2) or higher who have at least one weight-related comorbid condition (e.g., hypertension, dyslipidemia, insulin resistance, type 2 diabetes mellitus). Liraglutide is a glucagon-like peptide-1 receptor agonist that has been successfully used in the treatment of type 2 diabetes for several years. Weight loss has been well described as an additional benefit with liraglutide therapy, which prompted the manufacturer to evaluate and develop a higher dose formulation specifically for the treatment of obesity. Liraglutide 3 mg/day was approved by the U.S. Food and Drug Administration for this indication in December 2014. We performed a search of the Medline database to identify relevant literature focused on liraglutide's role specifically in treating obesity. Five clinical trials with this primary end point were identified. Data demonstrated that liraglutide can successfully achieve weight-loss benchmarks of 5% or more and 10% or more loss from baseline. The most common adverse effects were gastrointestinal and mild to moderate in intensity. The cost of therapy is high, averaging over $1000/month for out-of-pocket expenses if insurance coverage is not available. Liraglutide is also available for delivery only by subcutaneous injection, which may represent a barrier for patients. Liraglutide 3 mg/day represents another pharmacologic option for the treatment of obesity. Topics: Anti-Obesity Agents; Body Weight; Comorbidity; Drug Approval; Glucagon-Like Peptide 1; Humans; Liraglutide; Obesity; Randomized Controlled Trials as Topic; United States; United States Food and Drug Administration; Weight Loss | 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 |
Moving beyond energy homeostasis: new roles for glucagon-like peptide-1 in food and drug reward.
Glucagon-like peptide-1 (GLP-1), a hormone and neuropeptide, is known to regulate energy homeostasis in part through an established central role in controlling food intake. Historically this central role has largely been attributed to GLP-1 receptor signaling in the brainstem and hypothalamus. However, emerging data indicate that GLP-1 also contributes to non-homeostatic regulation of food reward and motivated behaviors in brain reward centers, including the ventral tegmental area and nucleus accumbens. The hypothesis that GLP-1 signaling modulates reward circuitry has provided the impetus for studies demonstrating that GLP-1 attenuates reward for psychostimulants and alcohol. Here, we examine current evidence for GLP-1-mediated regulation of food and drug reward and use these findings to hypothesize mechanisms of action within brain reward centers. Topics: Animals; Dopamine; Eating; Energy Metabolism; Glucagon-Like Peptide 1; Homeostasis; Humans; Obesity; Reward; Substance-Related Disorders | 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 |
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 |
[Cutting-edge of medicine; the prospects of novel anti-obesity drugs].
Topics: Anti-Obesity Agents; Appetite; Appetite Depressants; Benzazepines; Benzoxazines; Bupropion; Clinical Trials as Topic; Drug Approval; Drug Combinations; Drug Discovery; Energy Metabolism; Enzyme Inhibitors; Fructose; Glucagon-Like Peptide 1; Humans; Hypothalamus; Lactones; Lipase; Liraglutide; Metabolic Syndrome; Naltrexone; Obesity; Orlistat; Phentermine; Topiramate | 2014 |
Liraglutide in the treatment of obesity.
Obesity is a global epidemic with important healthcare and financial implications. Most current antiobesity pharmacological therapies are unsatisfactory due to undesirable side effects. Many drugs have been withdrawn due to safety concerns. Maintaining weight loss remains the Achilles' heel of antiobesity therapy.. This is an overview of the use of liraglutide for obesity treatment. Clinical efficacy on weight, cardiovascular parameters, as well as safety and tolerability issues are discussed.. Liraglutide is a glucagon-like peptide 1 (GLP-1) receptor agonist, which has a protracted pharmacokinetic profile compared to native GLP-1 while maintaining its biological activity. It induces weight loss by reducing appetite and energy intake. It stimulates insulin release and decreases glucagon secretion in response to hyperglycaemia. Treatment with liraglutide, in addition with diet and exercise, induces sustained mean weight loss of 7.6 kg at 2 years (weight loss induced by orlistat = 5.7 kg, phentermine/topiramate controlled release 15/92 = 10.9 kg). It reduces blood pressure and improves glycaemic control, which has clinically relevant significance on reducing obesity-related morbidity and mortality. Liraglutide is reasonably well tolerated with gastrointestinal side effects being most commonly encountered. Novo Nordisk filed for regulatory approval of liraglutide 3.0 mg for obesity treatment in December 2013. Topics: Animals; Anti-Obesity Agents; Blood Glucose; Glucagon-Like Peptide 1; Glucagon-Like Peptide-1 Receptor; Humans; Hyperglycemia; Hypoglycemic Agents; Lactones; Liraglutide; Obesity; Orlistat; Receptors, Glucagon; Treatment Outcome; Weight Loss | 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 |
Adipose tissue dysfunction and inflammation in cardiovascular disease.
Adipose tissue (AT) was long perceived as a passive lipid storage depot but it is now considered as an endocrine organ that produces a large number of mediators that affect metabolism, inflammation and coagulation. In obesity, the increased size of adipocytes and chronic low-grade inflammation within AT alter its normal physiological function. AT dysfunction results in altered production and secretion of adipokines, which in turn affect several tissues, e.g. the liver, skeletal muscles and vasculature, in a para- or endocrine manner. Numerous circulating proinflammatory mediators involved in the development of cardiovascular disease (CVD) are directly released from adipocytes, thereby linking obesity to an increased cardiovascular risk. In the current chapter, we focus, on the one hand, on a small selection of novel adipokines with a potentially strong link to CVD: soluble dipeptidyl peptidase-4, visfatin and lipocalin-2. On the other hand, we summarize the most recent findings on the novel cardioprotective adipokines omentin and apelin. Topics: Acute-Phase Proteins; Adipocytes; Adipokines; Adipose Tissue; Apelin; Cardiovascular Diseases; Cytokines; Dipeptidyl Peptidase 4; Dipeptidyl-Peptidase IV Inhibitors; Glucagon-Like Peptide 1; GPI-Linked Proteins; Humans; Inflammation; Intercellular Signaling Peptides and Proteins; Lectins; Lipocalin-2; Lipocalins; Nicotinamide Phosphoribosyltransferase; Obesity; Proto-Oncogene Proteins; Risk Factors | 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 |
Tolerability and safety of the new anti-obesity medications.
Worldwide obesity prevalence has nearly doubled since 1980. Due to numerous co-morbidities, obesity represents a serious health and socioeconomic problem worldwide. Pharmacotherapy should be an integral part of comprehensive obesity management. Drug therapy can assist in weight loss and its maintenance in those individuals who do not achieve appropriate weight loss through lifestyle interventions alone. After the withdrawal of sibutramine from the market in 2010, orlistat, a lipase inhibitor, was the only remaining prescription drug approved for the long-term treatment of obesity. In 2012, phentermine/topiramate extended-release (PHEN/TPM ER) combination and lorcaserin were approved by the US FDA as novel medications for long-term weight management. Three major phase III trials conducted with each drug confirmed their efficacy in terms of weight loss/maintenance and improvement of cardiometabolic risks. No head-to-head studies between the two new anti-obesity drugs have been carried out. However, in the existing studies PHEN/TPM ER had a superior weight loss profile to lorcaserin but the incidence of adverse effects was lower with lorcaserin. Both drugs were well-tolerated, and adverse events were modest in intensity, dose dependent, rather rare, and tended to decrease with the duration of treatment. Major safety concerns regarding PHEN/TPM ER include elevations in resting pulse rate, teratogenicity, mild metabolic acidosis, and psychiatric and cognitive adverse events. Valvulopathy, cognitive impairment, psychiatric disorders, and hypoglycemia represent major safety concerns for lorcaserin. Although existing trials have not demonstrated any significant issues with PHEN/TPM ER-induced heart rate elevation and lorcaserin-induced valvulopathy, all safety concerns should be seriously taken into account in patients treated with either of these novel anti-obesity medications. Topics: Anti-Obesity Agents; Benzazepines; Benzoxazines; Bupropion; Chemistry, Pharmaceutical; Drug-Related Side Effects and Adverse Reactions; Fructose; Glucagon-Like Peptide 1; Humans; Liraglutide; Naltrexone; Obesity; Phentermine; Topiramate | 2014 |
Overview of new antiobesity drugs.
A short overview of new drugs approved for the treatment of obesity (lorcaserin, phentermine/topiramate combination) as well as those with a perspective for approval as antiobesity drugs (cetilistat, naltrexone/bupropion combination, liraglutide) is presented. All these drugs produce significant weight loss accompanied by reductions in cardiometabolic health risks. Although the adverse events were rather rare and tended to decrease with the duration of treatment with most of these medications, the drug-specific safety concerns should be seriously considered. In order to ensure an appropriate, efficient and safe implementation of novel antiobesity drugs into the comprehensive treatment of obesity, it will be necessary to establish a network of physicians and other health-care providers well educated in obesity management. Topics: Anti-Obesity Agents; Benzazepines; Benzoxazines; Bupropion; Drug Combinations; Fructose; Glucagon-Like Peptide 1; Humans; Liraglutide; Naltrexone; Obesity; Phentermine; Topiramate; Weight Loss | 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 |
Evolving directions in obesity management.
Over the past decade, treatment for obesity has been limited because of an incomplete understanding of the pathophysiology of obesity, lack of recognition of it as a disease, and limited efficacy of treatment options. Safety concerns related to medical and surgical approaches for obesity have also been a major barrier. The challenging nature of obesity management is reflected in a survey of primary care physicians which indicated that treating patients with obesity can be as difficult as treating patients with nicotine or alcohol dependence. Topics: Anti-Obesity Agents; Bupropion; Dopamine Uptake Inhibitors; Forecasting; Glucagon-Like Peptide 1; Glucagon-Like Peptide-1 Receptor; Humans; Incretins; Liraglutide; Naltrexone; Narcotic Antagonists; Obesity; Receptors, Glucagon | 2014 |
The role of gut endocrine cells in control of metabolism and appetite.
After food is ingested, nutrients pass through the gastrointestinal tract, stimulating the release of a range of peptide hormones. Among their many local, central and peripheral actions, these hormones act to mediate glucose metabolism and satiety. Indeed, it is the modification of gut hormone secretion that is considered partly responsible for the normalization of glycaemic control and the reduction in appetite seen in many patients after certain forms of bariatric surgery. This review describes recent developments in our understanding of the secretion and action of anorexigenic gut hormones, primarily concentrating on glucagon-like peptide-1 (GLP-1). Topics: Animals; Appetite Regulation; Brain; Eating; Energy Metabolism; Enteroendocrine Cells; Feeding Behavior; Gastrointestinal Tract; Glucagon-Like Peptide 1; Humans; Neural Pathways; Obesity; Signal Transduction | 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 |
[Hypoglycaemia after gastric bypass is a challenge to diagnostic procedures and treatment].
Treatment of severe obesity by Roux-en-Y gastric bypass (RYGB) causes sustained weight losses and improves health complica-tions. RYGB is, however, also associated with adverse effects. Dumping is a well-known complication causing invalidating symptoms, and lately there have been mounting concerns about post-RYGB hypoglycaemia. This condition is characterized by neuroglycopenia and inappropriately elevated insulin concentration. The mechanism behind this hypoglycaemia is not completely elucidated. Diagnostic procedures and treatment possibilities are discussed in this article. Topics: Blood Glucose; Dumping Syndrome; Gastric Bypass; Glucagon-Like Peptide 1; Humans; Hypoglycemia; Insulin; Obesity | 2014 |
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 |
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 |
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 |
Autonomic control and bariatric procedures.
The sudden improvement of metabolic profile and the remission of type 2 diabetes after bariatric surgery, well before weight loss, raise important new questions regarding glycemic control. Currently, various types of bariatric procedures target type 2 diabetes in obese and non-obese patients. Nevertheless, the origin of the dramatic metabolic improvements, including glucose homeostasis, is poorly understood, and the role of the gastrointestinal (GI) tract remains relatively speculative, as well as why these procedures are variably effective. One neglected explanation is that such interventions disrupt neural networks mediating GI-brain communication and could alter the autonomic output to the visceral organs, including the liver. Incretins, e.g., glucagon-like peptide 1 (GLP-1), have major influence on the central nervous system. Moreover, the level of GLP-1 is observed to significantly increase after bariatric surgery and could be a key factor in the weight-independent, anti-diabetic effect. Therefore, this review will evaluate the effect of GLP-1 on the central nervous system, with emphasis on the cellular effects of GLP-1, and will provide an overview of the autonomic control of the liver. Topics: Animals; Autonomic Nervous System; Bariatric Surgery; Blood Glucose; Glucagon-Like Peptide 1; Humans; Liver; Obesity | 2013 |
Glucagon-like peptide-1 receptor in the brain: role in neuroendocrine control of energy metabolism and treatment target for obesity.
The central glucagon-like peptide (GLP)-1 receptor mediates a number of metabolic processes, including feeding, body weight and glucose homeostasis. More recently, roles in energy expenditure and reward pathway modulation have been described. GLP-1 receptor agonism promotes insulin release and is currently used to treat type 2 diabetes humans, with a common side effect being weight loss. It is likely that many of these metabolic effects are mediated by GLP-1Rs located in the central nervous system, throughout areas known to be important in control of energy homeostasis. The physiological role of the GLP-1 receptor signalling in each of these brain nuclei is becoming clearer and the GLP-1 system appears to act as an integrator of peripheral energy availability and effector of metabolic regulation. This makes it an attractive target for obesity therapies, with excellent pre-clinical efficacy seen in molecules combining GLP-1 receptor agonism with glucagon receptor agonism. This review discusses what is known about the functions of the GLP-1 receptor in the central nervous system, and highlights the ways that this system may be targeted for development of new obesity therapeutics. Topics: Brain; Energy Metabolism; Glucagon-Like Peptide 1; Glucagon-Like Peptide-1 Receptor; Humans; Obesity; Receptors, Glucagon; Signal Transduction | 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 |
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 |
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 |
Interleukin-6 and obesity: the crosstalk between intestine, pancreas and liver.
The concept of IL-6 as a deleterious interleukin was challenged by its anti-inflammatory actions.. The beneficial health effects of exercise and the crosstalk between insulin-sensitive tissues and insulin-producing cells are mediated by IL-6.. IL-6 displays pleiotropic functions in a tissue-specific and physiological context-dependent manner. There is evidence suggesting that IL-6 worsens insulin resistance in the liver and adipose tissue, while improving insulin sensitivity in the muscle. The effects of this cytokine are influenced by its acute or chronical presence, the latter being associated with insulin resistance. IL-6 has anti-inflammatory effects and a compensatory role in obesity by increasing islet GLP-1 production. The therapeutic approach of blocking IL-6 signal can be diabetogenic. Topics: Anti-Inflammatory Agents; Enteroendocrine Cells; Exercise; Genetic Pleiotropy; Glucagon-Like Peptide 1; Glucagon-Secreting Cells; Homeostasis; Humans; Insulin; Insulin Resistance; Insulin Secretion; Interleukin-6; Intestines; Liver; Obesity; Pancreas | 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 |
The modulatory role of high fat feeding on gastrointestinal signals in obesity.
The gastrointestinal (GI) tract is a specialized sensory system that detects and responds to constant changes in nutrient- and bacterial-derived intestinal signals, thus contributing to controls of food intake. Chronic exposure to dietary fat causes morphological, physiological and metabolic changes leading to disruptions in the regulatory feeding pathways promoting more efficient fat absorption and utilization, blunted satiation signals and excess adiposity. Accumulating evidence demonstrates that impaired gastrointestinal signals following long-term high fat consumption are, at least partially, responsible for increased caloric intake. This review focuses on the role of dietary fat in modulating oral and post-oral chemosensory signaling elements responsible for lipid detection and responses, including changes in sensitivity to satiation signals, such as GLP-1, PYY and CCK and their impact on food intake and weight gain. Furthermore, the influence of the gut microbiota on mechanisms controlling energy regulation in the face of excessive fat exposure will be explored. The profound influence of dietary fats on altering complex regulatory feeding pathways can result in dysregulation of body weight and development of obesity, while restoration or manipulation of satiation signaling may prove an effective tool in prevention and treatment of obesity. Topics: Adiposity; Animals; CD36 Antigens; Cholecystokinin; Dietary Fats; Energy Intake; Gastrointestinal Tract; Ghrelin; Glucagon-Like Peptide 1; Humans; Intestinal Absorption; Microbiota; Obesity; Peptide YY; Receptors, G-Protein-Coupled; Satiation; Signal Transduction; Taste; Weight Gain | 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 |
Glucagon-like peptide-1 receptor agonists for weight loss in adult patients without diabetes.
The efficacy and safety of glucagon-like peptide (GLP)-1 receptor agonists for weight loss in adult patients without diabetes is reviewed.. GLP-1 receptor agonists have been associated with significant weight loss in patients with diabetes, raising the question of whether these agents could be used for weight loss in patients without diabetes. The mechanism by which GLP-1 receptor agonists induce weight loss is believed to be related to multiple actions involving the brain and gastrointestinal tract, with the primary action related to an increase in satiety. Trials examining the effects of GLP-1 receptor agonists for weight loss have compared exenatide, liraglutide, and orlistat. Of the studies completed to date, the majority of patients have been enrolled in trials involving liraglutide. Based on the reviewed literature, both exenatide 10 μg twice daily and liraglutide in dosages of up to 3 mg daily resulted in significant weight loss in patients without diabetes. A decrease in the proportion of patients with prediabetes was also found in studies of liraglutide. Nausea and vomiting were the most frequently reported adverse events in patients from these studies. Symptomatic hypoglycemia was reported in only one study with liraglutide in patients without diabetes and was not objectively confirmed by laboratory data. A higher frequency of psychiatric disorders, specifically insomnia, was reported by patients taking high doses of liraglutide.. GLP-1 receptor agonists offer a reasonable alternative for nondiabetic patients not able to achieve weight-loss goals with lifestyle modifications alone. Topics: Adult; Dose-Response Relationship, Drug; Exenatide; Glucagon-Like Peptide 1; Glucagon-Like Peptide-1 Receptor; Humans; Lactones; Life Style; Liraglutide; Obesity; Orlistat; Peptides; Receptors, Glucagon; Treatment Outcome; Venoms; Weight Loss | 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 |
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 |
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 |
Effects of dietary polyphenols on neuroregulatory factors and pathways that mediate food intake and energy regulation in obesity.
Polyphenols are natural substances and are enriched in vegetables, fruits, grains, bark, tea, and wine. Some polyphenols have insulin-potentiating and anti-inflammatory effects, both of which are important in obesity. Dietary supplementation with polyphenolic compounds is associated with reduced diet-induced obesity and/or metabolic syndrome in animal and human studies. Insights into mechanisms that regulate food intake and satiety have led to an increased understanding of obesity but the pathogenesis underlying obesity is lacking. Food intake is subject to a complex regulation by the hypothalamus and other brain centers including the brain stem and the hippocampus. An intricate network of interacting feedback mechanisms that involve the aforementioned neural centers along with the stomach, gut, liver, thyroid, and adipose tissue in the periphery, influence the eventual outcome of food intake and satiety. Key peripheral signals, such as leptin, insulin, and ghrelin, have been linked to hypothalamic neuropeptide systems in energy regulation. This review will examine the neural centers important in food intake, the role of various neuropeptides, and the neurohormonal influence on food intake. The potential role of polyphenols in influencing the neuroregulatory factors, the neural signaling pathways and/or the peripheral feedback mechanisms that modulate food intake will also be examined. Topics: Agouti-Related Protein; Animals; Dietary Supplements; Energy Intake; Gastric Mucosa; Ghrelin; Glucagon-Like Peptide 1; Humans; Hypothalamic Hormones; Hypothalamus; Insulin; Islet Amyloid Polypeptide; Leptin; Liver; Melanins; Melanocortins; Neuropeptide Y; Neurotransmitter Agents; Obesity; Peptide YY; Pituitary Hormones; Polyphenols; Satiation; Signal Transduction; Stomach; Thyroid Gland | 2013 |
Incretin hormones and the satiation signal.
Recent research has indicated that appetite-regulating hormones from the gut may have therapeutic potential. The incretin hormone, glucagon-like peptide-1 (GLP-1), appears to be involved in both peripheral and central pathways mediating satiation. Several studies have also indicated that GLP-1 levels and responses to meals may be altered in obese subjects. Clinical trial results have shown further that two GLP-1 receptor agonists (GLP-1 RAs), exenatide and liraglutide, which are approved for the treatment of hyperglycemia in patients with type 2 diabetes, also produce weight loss in overweight subjects without diabetes. Thus, GLP-1 RAs may provide a new option for pharmacological treatment of obesity. Topics: Animals; Eating; Exenatide; Gastric Inhibitory Polypeptide; Glucagon-Like Peptide 1; Glucagon-Like Peptide-1 Receptor; Humans; Hyperglycemia; Hypoglycemic Agents; Incretins; Liraglutide; Obesity; Peptides; Receptors, Glucagon; Satiation; Signal Transduction; Venoms; 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 |
GLP-1R and amylin agonism in metabolic disease: complementary mechanisms and future opportunities.
The discoveries of the incretin hormone glucagon-like peptide-1 (GLP-1) and the β-cell hormone amylin have translated into hormone-based therapies for diabetes. Both classes of molecules also exhibit weight-lowering effects and have been investigated for their anti-obesity potential. In the present review, we explore the mechanisms underlying the physiological and pharmacological actions of GLP-1 and amylin agonism. Despite their similarities (e.g. both molecular classes slow gastric emptying, decrease glucagon and inhibit food intake), there are important distinctions between the central and/or peripheral pathways that mediate their effects on glycaemia and energy balance. We suggest that understanding the similarities and differences between these molecules holds important implications for the development of novel, combination-based therapies, which are increasingly the norm for diabetes/metabolic disease. Finally, the future of GLP-1- and amylin agonist-based therapeutics is discussed. Topics: Animals; Diabetes Mellitus; Eating; Gastric Emptying; Glucagon; Glucagon-Like Peptide 1; Glucagon-Like Peptide-1 Receptor; Humans; Islet Amyloid Polypeptide; Metabolic Diseases; Obesity; 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 |
Gastrointestinal regulatory peptides and central nervous system mechanisms of weight control.
This review focuses on recent advances in understanding the multiple roles of gastrointestinal peptides in the control of food intake and body weight with specific emphasis on ghrelin, amylin and glucagon-like peptide 1.. Recent studies support a role for ghrelin, amylin and glucagon-like peptide 1 in short-term and long-term effects on food intake and body weight. Apart from contributing to energy homeostasis, ghrelin's participation in reward and sensory processing has been the focus of much recent work. New findings on amylin's effects on food intake and energy balance provide further support for its role in meal-related food intake and suggest that it may also function as an adiposity signal. New investigations on the role of central and peripheral glucagon-like peptide 1 receptors in mediating the anorexic effects of glucagon-like peptide 1 have suggested that they differentially contribute to short-term and long term effects on food intake.. Gastrointestinal peptides can influence food intake through mechanisms that involve short-term meal-related effects or through activation of central pathways involved in energy balance. An appreciation of the multiple actions of gastrointestinal peptides on food intake will aid in developing new strategies for weight management. Topics: Animals; Appetite Depressants; Appetite Regulation; Body Weight; Eating; Energy Metabolism; Feeding Behavior; Ghrelin; Glucagon-Like Peptide 1; Humans; Islet Amyloid Polypeptide; Mice; Obesity; Rats | 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 |
Anorexigenic effects of GLP-1 and its analogues.
GLP-1 receptors are expressed in the brain, especially in the regions responsible for the regulation of food intake, and intracerebroventricular injection of GLP-1 results in inhibition of food intake. Peripheral administration of GLP-1 dose-dependently enhances satiety and reduces food intake in normal and obese subjects as well as in type 2 diabetic patients. So far, the mechanisms by which GLP-1 exerts its effects are not completely clear. Interactions with neurons in the gastrointestinal tract or possibly direct access to the brain through the blood-brain barrier as observed in rats are possible and discussed in this chapter as well as a novel hypothesis based on the finding that GLP-1 is also expressed in taste cells. Finally, the role of GLP-1 receptor agonists as a possible treatment option in obesity is discussed as well as the role of GLP-1 in the effects of bariatric surgery on adiposity and glucose homeostasis. Topics: Animals; Appetite Depressants; Appetite Regulation; Bariatric Surgery; Body Weight; Brain; Eating; Glucagon-Like Peptide 1; Glucagon-Like Peptide-1 Receptor; Humans; Incretins; Obesity; Receptors, Glucagon; Satiety Response; Signal Transduction | 2012 |
The role of gut hormones in controlling the food intake: what is their role in emerging diseases?
Central nervous system (CNS) receives peripheral relevant information that are able to regulate individual's energy balance through metabolic, neural, and endocrine signals. Ingested nutrients come into contact with multiple sites in the gastrointestinal tract that have the potential to alter peptide and neural signaling. There is a strong relationship between CNS and those peripheral signals (as gastrointestinal hormones) in the control of food intake. The purpose of this review is to give updated information about the role of gut hormones as mediators of feeding behavior and of different nutrients in modulating gut hormones production. The role of gut hormones in the pathogenesis of emerging diseases as obesity and non-alcoholic fatty liver disease (NAFLD) is also discussed together with the possible role of these peripheral signals as targets of future therapeutic options. Topics: Animals; Arcuate Nucleus of Hypothalamus; Brain Stem; Cholecystokinin; Eating; Energy Intake; Energy Metabolism; Fatty Liver; Feeding Behavior; Gastrointestinal Hormones; Ghrelin; Glucagon-Like Peptide 1; Humans; Hunger; Hyperphagia; Non-alcoholic Fatty Liver Disease; Obesity; Peptide YY; Satiation | 2012 |
[The pharmacological treatment of obesity: past, present and future].
Currently, obesity presents one of the biggest health problems. Management strategies for weight reduction in obese individuals include changes in life style such as exercise and diet, behavioral therapy, and pharmacological treatment, and in certain cases surgical intervention. Diet and exercise are best for both prevention and treatment, but both require much discipline and are difficult to maintain. Drug treatment of obesity offer a possible adjunct, but it may only have modest results, limited by side effects; furthermore, the weight lowering effects last only as long as the drug is being taken and, unfortunately, as soon as the administration is stopped, the weight is regained. These strategies should be used in a combination for higher efficacy. Drugs used to induce weight loss have various effects: they increase satiety, reduce the absorption of nutrients or make metabolism faster; but their effect is usually moderate. In the past, several drugs were used in the pharmacological therapy of weight reduction including thyroid hormone, dinitrophenol, amphetamines and their analogues, e.g. fenfluramine, At present, only orlistat is available in the long term treatment (≥ 24 weeks) of obesity as sibutramine and rimonabant were withdrawn form the market. Several new anti-obesity drugs are being tested at present, and liraglutide, a GLP-1 analogue (incretin mimetic), is the most promising one. Topics: Amides; Anti-Obesity Agents; Anticonvulsants; Antidepressive Agents; Basal Metabolism; Benzazepines; Benzoxazines; Body Mass Index; Bridged Bicyclo Compounds, Heterocyclic; Ciliary Neurotrophic Factor; Clinical Trials as Topic; Combined Modality Therapy; Cyclobutanes; Dexfenfluramine; Fatty Acids; Female; Fenfluramine; Glucagon-Like Peptide 1; Human Growth Hormone; Humans; Intestinal Absorption; Lactones; Leptin; Life Style; Liraglutide; Male; Norepinephrine; Obesity; Obesity, Morbid; Orlistat; Piperidines; Pyrazoles; Pyridines; Receptor, Melanocortin, Type 4; Rimonabant; Satiation; Serotonin; Sodium-Glucose Transport Proteins; Sucrose; Thyroid Hormones | 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 |
The impact of bariatric surgery on nonalcoholic steatohepatitis.
Nonalcoholic steatohepatitis (NASH) is a stage of nonalcoholic fatty liver disease (NAFLD), and in most patients, is associated with obesity and the metabolic syndrome. The current best treatment of NAFLD and NASH is weight reduction with the current options being life style modifications, with or without pharmaceuticals, and bariatric surgery. Bariatric surgery is an effective treatment option for individuals who are severely obese (body mass index ≥ 35 kg/m(2)), and provides for long-term weight loss and resolution of obesity-associated diseases in most patients. Regression and/or histologic improvement of NASH have been documented after bariatric surgery. We review the available literature reporting on the impact of the various bariatric surgery techniques on NASH. Topics: Bariatric Surgery; Fatty Liver; Ghrelin; Glucagon-Like Peptide 1; Humans; Non-alcoholic Fatty Liver Disease; Obesity; Peptide YY; Weight Loss | 2012 |
Effects of glucagon-like peptide-1 receptor agonists on body weight: a meta-analysis.
Glucagon-Like Peptide-1 receptor agonists (GLP-1RAs), approved as glucose-lowering drugs for the treatment of type 2 diabetes, have also been shown to reduce body weight. An extensive Medline, Cochrane database, and Embase search for "exenatide," "liraglutide," "albiglutide," "semaglutide," and "lixisenatide" was performed, collecting all randomized clinical trials on humans up to December 15, 2011, with a duration of at least 24 weeks, comparing GLP-1 receptor agonists with either placebo or active drugs. Twenty two (7,859 patients) and 7 (2,416 patients) trials with available results on body weight at 6 and 12 months, respectively, were included. When compared with placebo, GLP-1RAs determine a reduction of BMI at 6 months of -1.0 [-1.3; -0.6] kg/m(2). Considering the average BMI at baseline (32.4 kg/m(2)) these data means a weight reduction of about 3% at 6 months. This result could seem modest from a clinical standpoint; however, it could be affected by many factors contributing to an underestimation of the effect of GLP-1RA on body weight, such as non adequate doses, inclusion criteria, efficacy of GLP-1RA on reducing glycosuria, and association to non-pharmacological interventions not specifically aimed to weight reduction. Topics: Blood Glucose; Body Mass Index; Body Weight; Exenatide; Glucagon-Like Peptide 1; Glucagon-Like Peptide-1 Receptor; Humans; Liraglutide; Obesity; Peptides; Placebos; Quality Control; Randomized Controlled Trials as Topic; Receptors, Glucagon; Time Factors; Venoms | 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 |
The effects of food components on hormonal signalling in gastrointestinal enteroendocrine cells.
The incidence of obesity and obesity-associated diseases, such as type-2 diabetes, has reached epidemic proportions in recent years. It is predicted that by 2015 over 1.5 billion consumers will be overweight or obese. Several of the current drug-based treatments on the market for weight management and appetite control either lack efficacy or are associated with adverse side-effects. There is, therefore, an opportunity to develop functional foods which are both nutritionally beneficial but which also aid in weight management. Peptides produced in the gastrointestinal tract, which function to regulate feed intake and satiety, have been identified as key targets for bioactive ingredients in functional foods. These peptides are produced and released by specialised enteroendocrine cells. Understanding the interaction of foods with these cells is vital to the development of food matrices with positive health benefits. This review describes enteroendocrine cell populations in detail and focuses on the peptides that they produce in addition to their other functions, including taste transduction. Several food-based sources of bioactives and current food products on the market with beneficial effects on satiety and glycaemia will also be discussed. Topics: Appetite Regulation; Enteroendocrine Cells; Gastrointestinal Hormones; Gastrointestinal Tract; Glucagon-Like Peptide 1; Glycemic Index; Humans; Incretins; Obesity; Peptide Hormones; Satiation; Signal Transduction | 2012 |
Unraveling oxyntomodulin, GLP1's enigmatic brother.
Oxyntomodulin (OXM) is a peptide secreted from the L cells of the gut following nutrient ingestion. OXM is a dual agonist of the glucagon-like peptide-1 receptor (GLP1R) and the glucagon receptor (GCGR) combining the effects of GLP1 and glucagon to act as a potentially more effective treatment for obesity than GLP1R agonists. Injections of OXM in humans cause a significant reduction in weight and appetite, as well as an increase in energy expenditure. Activation of GCGR is classically associated with an elevation in glucose levels, which would be deleterious in patients with T2DM, but the antidiabetic properties of GLP1R agonism would be expected to counteract this effect. Indeed, OXM administration improved glucose tolerance in diet-induced obese mice. Thus, dual agonists of the GCGR and GLP1R represent a new therapeutic approach for diabetes and obesity with the potential for enhanced weight loss and improvement in glycemic control beyond those of GLP1R agonists. Topics: Animals; Diabetes Mellitus; Glucagon-Like Peptide 1; Glucagon-Like Peptide-1 Receptor; Humans; Obesity; Oxyntomodulin; Receptors, Glucagon | 2012 |
Recent advancements in drug treatment of obesity.
The prevalence of obesity is rising worldwide, with the U.K. having the highest prevalence in Europe. Obesity is associated with significant morbidity and has substantial healthcare implications, with current projections estimating that by 2030 obesity will cost the NHS approximately pounds 2 billion each year. Lifestyle modification remains the cornerstone of anti-obesity treatment, but drugs can be introduced as adjuncts to assist and maintain weight loss. Some 1.45 million obesity-related prescriptions were dispensed in 2009, highlighting the high demand for obesity pharmacotherapy. At present, the lipase inhibitor orlistat (Xenical) is the only UK-approved long-term medical therapy for obesity. Double-blind clinical trials have shown that orlistat significantly increases weight loss compared to placebo, but the array of adverse side effects associated with orlistat limits its tolerability. The need for more effective and better-tolerated anti-obesity medications is clear and six therapies have reached phase-III trials. Topics: Anti-Obesity Agents; Benzazepines; Benzoxazines; Bupropion; Clinical Trials as Topic; Drug Combinations; Fructose; Glucagon-Like Peptide 1; Humans; Lactones; Life Style; Liraglutide; Naltrexone; Obesity; Orlistat; Phentermine; Topiramate; Weight Loss | 2012 |
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 |
[Diabetes and thyroid disorders].
Both diabetes mellitus and thyroid disorders are common diseases. According to epidemiologic studies the prevalence of specific thyroid disorders in diabetic subjects is two times higher. Risk factors are age, female gender and autoimmune diabetes mellitus. However, thyroid disorders are diagnosed only half of the cases in diabetic population. The review briefly summarizes the association of autoimmune diabetes mellitus and thyreoiditis, the risk of thyroid disorders in type 1 diabetic pregnant women. Furthermore, the influence of obesity in the risk on thyroid cancer and the effect of glucagon-like peptide 1 analogue on thyroid medullary C-cells are discussed. Topics: Age Factors; Autoimmunity; Carbohydrate Metabolism; Comorbidity; Diabetes Complications; Diabetes Mellitus; Diabetes Mellitus, Type 1; Female; Glucagon-Like Peptide 1; Humans; Hyperthyroidism; Hypothyroidism; Iodide Peroxidase; Obesity; Pregnancy; Pregnancy Complications; Pregnancy in Diabetics; Risk Factors; Sex Factors; Thyroid Diseases; Thyroid Hormones; Thyroid Neoplasms; Thyroiditis, Autoimmune | 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 |
[Food intake-suppressing action of incretin and anti-obesity therapy].
Suppressing food intake is the most well-known central nervous action of glucagon-like peptide-1 (GLP-1). Neurons expressing preproglucagon (PPG) in the nucleus tractus solitarius (NTS) are the only source of "central" GLP-1, and they project to the hypothalamus. Recently, properties of these PPG-neurons have been revealed using transgenic mice expressing fluorescent protein under control of the PPG promoter; whereas they are directly responsible to leptin but not to GLP-1, they can be the second-order neurons of vagal afferents. "Peripheral" GLP-1 released from intestinal L-cells may possess central nervous action through the vagal afferent fibers. The question remains whether food intake suppression due to "peripheral" GLP-1 depends on "central" one. The action is being applied to anti-obesity therapy. Topics: Animals; Appetite; Glucagon-Like Peptide 1; Humans; Mice; Obesity; Oxyntomodulin | 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 |
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 |
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 |
[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 |
Therapeutic potential of gut peptides.
A great deal of research interest is directed toward understanding the control of appetite and regulation of metabolism. It seems as if an epidemic of obesity is sweeping the world, and type II diabetes (T2DM) is following in its wake. The regulation of energy homeostasis is an area that straddles neurobiology, classical endocrinology and metabolism. It is currently one of the most exciting and rapidly advancing topics in medical research, and is also one of the most frustrating areas. The availability of highly palatable, calorie-dense food, together with the low requirement for physical activity in our modern environment, are major factors contributing to the obesity epidemic. If energy intake exceeds energy use, the excess calories are stored as body fat. Knowledge of the homeostatic system that controls body weight has increased dramatically over the last years and has revealed new potential targets for the treatment of obesity. One therapeutic approach is the development of agents based on the gastrointestinal hormones that control food intake and appetite. This review discusses several gut hormones and ligands for their receptors as potential anti-obesity treatments. Topics: Amyloid; Gastrointestinal Hormones; Ghrelin; Glucagon-Like Peptide 1; Humans; Islet Amyloid Polypeptide; Obesity; Peptide YY | 2010 |
Managing highly insulin-resistant diabetes mellitus: weight loss approaches and medical management.
The prevalence of obesity and diabetes is epidemic. Severe insulin resistance (defined as the need for > or = 200 units of insulin per day to achieve glycemic control) is commonly seen with obesity and can complicate diabetes management. The management of patients with diabetes who have severe insulin resistance is difficult, and at times frustrating, and requires a multifaceted approach. Weight loss is the best treatment option, which can be a challenging task for patients to achieve and maintain. Medications that decrease insulin needs like metformin, thiazolidinediones, or pramlintide may help, but some patients also need high doses of insulin. This article reviews these different treatment options and provides practical advice on weight loss, use of insulin sensitizers, and use of U-500 insulin. Topics: Amyloid; Bariatric Surgery; Diabetes Mellitus; Diet, Reducing; Dipeptidyl-Peptidase IV Inhibitors; Exenatide; Exercise; Glucagon-Like Peptide 1; Humans; Hypoglycemic Agents; Insulin; Insulin Resistance; Islet Amyloid Polypeptide; Liraglutide; Metformin; Obesity; Peptides; Thiazolidinediones; Treatment Failure; Venoms; Weight Loss | 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 |
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 |
Pharmacological management of appetite expression in obesity.
For obese individuals, successful weight loss and maintenance are notoriously difficult. Traditional drug development fails to exploit knowledge of the psychological factors that crucially influence appetite, concentrating instead on restrictive criteria of intake and weight reduction, allied to a mechanistic view of energy regulation. Drugs are under development that may produce beneficial changes in appetite expression in the obese. These currently include glucagon-like peptide-1 analogs such as liraglutide, an amylin analog davalintide, the 5-HT(2C) receptor agonist lorcaserin, the monoamine re-uptake inhibitor tesofensine, and a number of combination therapies such as pramlintide and metreleptin, bupropion and naltrexone, phentermine and topiramate, and bupropion and zonisamide. However, the effects of these treatments on eating behavior remain poorly characterized. Obesity is typically a consequence of overconsumption driven by an individual's natural sensitivity to food stimuli and the pleasure derived from eating. Intuitively, these processes should be effective targets for pharmacotherapy, and behavioral analysis can identify drugs that selectively affect desire to eat, enjoyment of eating, satiation or postmeal satiety. Rational interventions designed specifically to modulate these processes could limit the normally aversive consequences of caloric restriction and maximize an individual's capacity to successfully gain control over their appetite. Topics: Anti-Obesity Agents; Appetite; Feeding Behavior; Glucagon-Like Peptide 1; Humans; Obesity; Satiation; Serotonin; Serotonin 5-HT2 Receptor Agonists | 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 |
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 |
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 |
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 |
Molecular neuroendocrine targets for obesity therapy.
Although energy balance is tightly regulated in order to maintain a specific level of adiposity, the incidence of obesity continues to increase. Consequently, it is essential that effective therapeutics for the treatment and prevention of obesity be developed. This review provides a brief update on some recent advances in the characterization of neuroendocrine targets for obesity therapy.. During the review period, considerable progress occurred in the understanding of previously described neuroendocrine regulators of energy balance, and several novel targets have been identified. Moreover, the understanding of the neural circuitry and molecular mechanisms of the neuroendocrine regulation of energy homeostasis has been expanded.. Energy balance is maintained by neuroendocrine signals arising from many tissues including the gastrointestinal tract and adipose tissue. These signals are integral to the cessation of meals and to the ability of the brain to monitor energy status and respond accordingly. Many current targets for obesity therapy are based on manipulating the activity of these signals and their receptors; however, to date, clinical-weight loss based on this strategy has been minimal and alternative approaches such as combinatorial therapies are emerging. Topics: Adipose Tissue; Animals; Appetite Regulation; Cholecystokinin; Energy Intake; Gastrointestinal Tract; Ghrelin; Glucagon-Like Peptide 1; Humans; Insulin; Leptin; Mice; Neurosecretory Systems; Obesity; Weight Loss | 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 |
Gut hormones and appetite control.
The gastrointestinal tract is the largest endocrine organ in the body. It secretes more than 20 different peptide hormones, which serve both a local regulatory function and provide a means by which the gut can regulate appetite and satiety. As the worldwide prevalence of obesity reaches epidemic proportions, the importance of delineating the mechanisms which regulate food intake becomes even more urgent. There is now a substantial body of work in both rodent and human models demonstrating the effects of these peptides on appetite and work is underway to therapeutically manipulate the gut-brain axis for the treatment of obesity. In addition, it may also be possible to use our understanding of the entero-endocrine system to treat calorie-deficient states. Topics: Animals; Appetite Regulation; Cholecystokinin; Eating; Gastrointestinal Hormones; Ghrelin; Glucagon-Like Peptide 1; Humans; Models, Animal; Obesity; Oxyntomodulin; Pancreatic Polypeptide; Peptide YY; Satiety Response | 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 |
Minireview: Gut peptides: targets for antiobesity drug development?
Gut peptides play multiple roles in the controls of gastrointestinal function and in the initiation and termination of meals. Plasma levels of these peptides are differentially affected by the presence of nutrients in the digestive tract, and the patterns of peptide release are consistent with both their feeding stimulatory and inhibitory actions. A number of these peptide systems have been investigated as potential targets for antiobesity drug development. Progress has been made in developing long-acting peptide analogs and, in some cases, nonpeptide agonists and antagonists. Whether any individual approach will have significant long-term efficacy remains to be demonstrated. Approaches that target multiple systems may hold the most promise. Topics: Anti-Obesity Agents; Cholecystokinin; Eating; Gastrointestinal Hormones; Glucagon-Like Peptide 1; Humans; Obesity; Peptide YY | 2009 |
Peripheral mechanisms in the control of appetite and related experimental therapies in obesity.
The function of the stomach and the gut hormonal responses to food ingestion constitute highly integrated homeostatic responses that maintain euglycemia and normal digestion. This intrinsic feedback involves vagal and hormonal mechanisms. Important signals such as GLP-1 and PYY that arise peripherally induce satiation and also delay gastric emptying or increase insulin secretion. Novel therapies are being developed to mimic or enhance these feedback mechanisms and to control appetite as a means to treat obesity. Topics: Animals; Anti-Obesity Agents; Appetite; Gastrointestinal Motility; Glucagon-Like Peptide 1; Humans; Incretins; Obesity; Peptide YY; Satiation | 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 |
Gut hormones: implications for the treatment of obesity.
Bariatric surgery is the only effective treatment for patients with morbid obesity. This is no solution to the present obesity pandemic however. Currently licensed non-surgical pharmaceuticals are of limited efficacy and alternatives are needed. Harnessing the body's own appetite-regulating signals is a desirable pharmacological strategy. The gastrointestinal tract has a prime role in sensing and signalling food intake to the brain. Gut hormones are key mediators of this information, including: peptide YY (PYY), pancreatic polypeptide (PP), glucagon-like peptide 1 (GLP-1), oxyntomodulin (OXM), ghrelin, amylin and cholecystokinin (CCK). This review summarises the latest knowledge regarding the physiological and pathophysiological role of gut hormones in regulating our food intake and how this knowledge could guide, or has guided, the development of weight-loss drugs. Up-to-date outcomes of clinical trials are evaluated and directions for the future suggested. Topics: Amyloid; Animals; Cholecystokinin; Gastrointestinal Hormones; Ghrelin; Glucagon-Like Peptide 1; Humans; Islet Amyloid Polypeptide; Obesity; Oxyntomodulin; Pancreatic Polypeptide; Peptide YY | 2009 |
Mining incretin hormone pathways for novel therapies.
The incretin hormones, glucose-dependent insulinotropic polypeptide (GIP) and glucagon-like peptide-1 (GLP-1), are produced predominantly by enteroendocrine cells and have multiple blood glucose-lowering effects. Recent years have seen a surge of interest in understanding the basic physiology and pathophysiology of incretins and in applying this knowledge to the treatment of diabetes and obesity. Considerable gains have been made in elucidating the mechanisms controlling incretin secretion, and there is growing evidence to suggest that incretins might be involved in the rapid reversal of diabetes observed in gastric bypass patients. Here, we review these recent advances and outline the multiple strategies being pursued to exploit the potential therapeutic benefits of GIP and GLP-1. Topics: Animals; Bariatric Surgery; Diabetes Mellitus; Dipeptidyl-Peptidase IV Inhibitors; Drug Discovery; Eating; Enteroendocrine Cells; Gastric Inhibitory Polypeptide; Glucagon-Like Peptide 1; Humans; Hypoglycemic Agents; Incretins; Islets of Langerhans; Molecular Mimicry; Obesity | 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 |
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 |
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 |
[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 |
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 |
Gut hormones: a weight off your mind.
The increasing prevalence of obesity and the associated morbidity and mortality has resulted in a major research effort to identify mechanisms that regulate appetite. It is well established that the hypothalamus and brain stem are major sites in the central nervous system (CNS) that regulate appetite. Until recently the missing element has been how information regarding food intake and energy stores is communicated to the CNS. Gut hormones have recently been found to be an important element in this regulation, communicating information regarding food intake to the CNS. Several gut hormones have been found to exert anorectic effects. These include members of the Pancreatic Polypeptide (PP)-fold family, namely PP itself and also peptide tyrosine-tyrosine (PYY), the first gut hormone shown to have appetite-inhibiting properties. The other main class of anorectic gut hormones are those derived by proteolytic processing from proglucagon, most importantly glucagon-like peptide-1 (GLP-1) and oxyntomodulin. All of these are currently being investigated as the basis of treatments to prevent the development of obesity. So far the only gastrointestinal hormone demonstrated to stimulate appetite is ghrelin. Potential sites and mechanisms of action and therapeutic use of these gastrointestinal hormones are discussed. Topics: Animals; Appetite; Appetite Regulation; Body Weight; Gastrointestinal Hormones; Ghrelin; Glucagon-Like Peptide 1; Humans; Obesity; Oxyntomodulin; Pancreatic Polypeptide; Peptide YY; Proglucagon; Signal Transduction | 2008 |
Role of gut hormones in obesity.
A critical role for the gut in energy homeostasis has emerged. Gut hormones not only have a role in digestion but several of them have been found to modulate appetite in animals and humans. Current nonendocrine drugs for obesity are limited by their modest efficacies, and bariatric surgery is confined to use in severe cases. The discovery of important appetite-signaling pathways from the gut to the brain has led to the emergence of several gut hormone-derived drugs that are being investigated for clinical use. This article summarizes the physiology of the major gut hormones implicated in appetite regulation, and reviews clinical evidence that gives us insight into their potential as clinical treatments for obesity. Topics: Animals; Dipeptides; Gastrointestinal Hormones; Ghrelin; Glucagon-Like Peptide 1; Humans; Obesity; Oxyntomodulin; Pancreatic Polypeptide | 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 |
Current and emerging therapies in nonalcoholic fatty liver disease.
The prevalence of obesity and the metabolic syndrome (MS) is on the rise, and subsequently the hepatic manifestation of MS, nonalcoholic fatty liver disease (NAFLD), has become a common entity in clinical practice. Most patients with NAFLD face medical complications related to their underlying MS in other organ systems; however, a small but significant group of patients with the more aggressive form of fatty liver, nonalcoholic steatohepatitis (NASH), are at risk of developing cirrhosis and hepatocellular carcinoma. As patients are generally asymptomatic, often their disease goes unrecognized. This is particularly true for NASH, where liver biopsy is currently required to make the diagnosis. Once diagnosed, no one treatment has been shown to be universally efficacious and those that are of benefit are not without side effects. Effective treatment regimens directed at both decreasing insulin resistance as well as the processes leading to necroinflammation and hepatic fibrosis have been investigated and include lifestyle modification, surgical therapies, and pharmacotherapy. This review focuses on current and potential future therapies for NASH. Topics: Animals; Antioxidants; Bariatric Surgery; Body Mass Index; Cannabinoids; Cholagogues and Choleretics; Comorbidity; Fatty Liver; Glucagon-Like Peptide 1; Humans; Hydroxymethylglutaryl-CoA Reductase Inhibitors; Hypoglycemic Agents; Insulin Resistance; Lactones; Life Style; Metformin; Obesity; Orlistat; Piperidines; Pyrazoles; Rimonabant; Thiazolidinediones; Treatment Outcome; Ursodeoxycholic Acid; Weight Loss | 2008 |
Neuroendocrine control of food intake.
Appetite is regulated by a complex system of central and peripheral signals which interact in order to modulate the individual response to nutrient ingestion. Peripheral regulation includes satiety signals and adiposity signals, while central control is accomplished by several effectors, including the neuropeptidergic, monoaminergic and endocannabinoid systems. Satiety signals, including cholecystokinin (CCK), glucagon-like peptide-1 (GLP-1) and peptide YY (PYY), originate from the gastrointestinal (GI) tract during a meal and, through the vagus nerve, reach the nucleus tractus solitarius (NTS) in the caudal brainstem. From NTS afferents fibers project to the arcuate nucleus (ARC), where satiety signals are integrated with adiposity signals, namely leptin and insulin, and with several hypothalamic and supra-hypothalamic inputs, thus creating a complex network of neural circuits which finally elaborate the individual response to a meal. As for the neuropeptidergic system, ARC neurons secrete orexigenic substances, such as neuropeptide Y (NPY) and agouti-related peptide (AGRP), and anorexigenic peptides such as pro-opiomelanocortin (POMC) and cocaine- and amphetamine-regulated transcript (CART). Other brain areas involved in the control of food intake are located downstream the ARC: among these, the paraventricular nucleus (PVN), which produces anorexigenic peptides such as thyrotropin releasing hormone (TRH), corticotrophin releasing hormone (CRH) and oxytocin, the lateral hypothalamus (LHA) and perifornical area (PFA), secreting the orexigenic substances orexin-A (OXA) and melanin concentrating hormone (MCH). A great interest in endocannabinoids, important players in the regulation of food intake, has recently developed. In conclusion, the present work reviews the most recent insights into the complex and redundant molecular mechanisms regulating food intake, focusing on the most encouraging perspectives for the treatment of obesity. Topics: Adiposity; Animals; Anti-Obesity Agents; Appetite Regulation; Arcuate Nucleus of Hypothalamus; Biogenic Monoamines; Cannabinoid Receptor Modulators; Cholecystokinin; Feeding Behavior; Ghrelin; Glucagon-Like Peptide 1; Humans; Insulin; Leptin; Neuropeptides; Neurosecretory Systems; Obesity; Peptide YY; Pituitary Hormone-Releasing Hormones; Satiety Response; Signal Transduction | 2008 |
Gila monster's guide to surgery for obesity and diabetes.
Topics: Animals; Blood Glucose; Diabetes Mellitus; Exenatide; Gastric Emptying; Glucagon-Like Peptide 1; Humans; Lizards; Obesity; Peptides; Venoms | 2008 |
Can gut hormones control appetite and prevent obesity?
The current obesity epidemic is fuelled by the availability of highly palatable, calorie-dense food, and the low requirement for physical activity in our modern environment. If energy intake exceeds energy use, the excess calories are stored as body fat. Although the body has mechanisms that act to maintain body weight over time, they primarily defend against starvation and are less robust in preventing the development of obesity. Knowledge of this homeostatic system that controls body weight has increased exponentially over the last decade and has revealed new possibilities for the treatment of obesity and its associated comorbidities. One therapeutic target is the development of agents based on the gastrointestinal hormones that control appetite. This review discusses the hormones oxyntomodulin, peptide YY, glucagon-like peptide 1, pancreatic polypeptide, and ghrelin and their emerging potential as anti-obesity treatments. Topics: Appetite Depressants; Brain; Diet; Energy Intake; Gastrointestinal Hormones; Gastrointestinal Tract; Ghrelin; Glucagon-Like Peptide 1; Humans; Neurons; Obesity | 2008 |
Gut and hormones and obesity.
Following the discovery of secretin in 1902, a host of further peptide hormones that are synthesised and released from the gastrointestinal tract have been identified. While their roles in the regulation of gastrointestinal function have been known for some time, it is now evident that many of these hormones also physiologically regulate energy balance. Our understanding of how gut hormones signal to the brain has advanced significantly in recent years. Several hormones, including peptide YY, pancreatic polypeptide, oxyntomodulin, glucagon-like peptide 1 and cholecystokinin function as satiety signals. In contrast, only ghrelin, produced by the stomach, has emerged as a putative hunger signal, appearing to act both as a meal initiator and a long-term body weight regulator. Recent research suggests that gut hormones can be manipulated to regulate energy balance in man and that obese subjects retain sensitivity to the actions of gut hormones. The worldwide obesity pandemic continues unabated, despite public health initiatives and current best therapy. Future gut hormone-based therapies may provide an effective and well-tolerated treatment for obesity. Topics: Animals; Area Postrema; Cholecystokinin; Diet Therapy; Energy Metabolism; Feedback, Physiological; Gastrointestinal Hormones; Ghrelin; Glucagon-Like Peptide 1; Homeostasis; Humans; Hunger; Hypothalamus; Neuropeptide Y; Obesity; Oxyntomodulin; Pancreatic Polypeptide; Peptide YY; Receptors, Ghrelin; Satiety Response; Solitary Nucleus | 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 |
Mechanisms of disease: the role of gastrointestinal hormones in appetite and obesity.
The obesity epidemic is fast becoming one of the leading causes of mortality and morbidity worldwide. Over the past 30 years, gastrointestinal hormones have been increasingly understood to have an important role as regulators of appetite and energy balance in obese individuals. The levels of these hormones are modulated by bariatric surgery, and understanding how they are affected by such procedures can contribute to our comprehension of the underlying mechanisms by which these hormones affect obesity and its treatment. In this Review, we consider several gastrointestinal hormones that can contribute to obesity by modulating the activity of the gut-brain axis, and examine their specific effects on appetite, hunger and energy balance. Better understanding of the mechanisms by which these peptides exert their effects may enable the development of improved weight-loss medications and new treatments for obesity. Topics: Appetite; Bariatric Surgery; Cholecystokinin; Gastric Inhibitory Polypeptide; Gastrointestinal Hormones; Ghrelin; Glucagon-Like Peptide 1; Humans; Obesity; Oxyntomodulin; Pancreatic Polypeptide; Peptide Hormones; Peptide YY | 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 |
The multiple faces of glucagon-like peptide-1--obesity, appetite, and stress: what is next? A review.
By itself, glucagon-like peptide-1(GLP-1) appears to be an excellent drug for appetite control and the treatment of obesity. Unfortunately, few enzymes, such as IV dipeptidyl peptidase and renal excretin, degrade and render GLP-1 inactive within minutes. A receptor agonist, exendin-4, with a longer biological half-life than GLP-1, has been tried. Subcutaneous injection of exendin-4 or continuous IV injection of GLP-1 warrants further research and investigation. Topics: Animals; Appetite; Gastric Bypass; Ghrelin; Glucagon-Like Peptide 1; Humans; Obesity; Oxidative Stress; Oxyntomodulin; Peptide Hormones; Peptide YY | 2007 |
New targets for obesity pharmacotherapy.
An understanding of the mechanisms that regulate energy homeostasis is essential for understanding novel obesity therapies. The status of energy reserves is communicated to the brain by adiposity and satiety signals. These signals modify either anabolic or catabolic pathways and, consequently, alter food intake in line with signaled energy requirements. New antiobesity therapies are in development that target anabolic or catabolic regulatory networks to reduce food intake and/or increase energy expenditure to promote weight loss. Topics: Adiposity; Animals; Anti-Obesity Agents; Body Weight; Cannabinoid Receptor Modulators; Cholecystokinin; Energy Metabolism; Glucagon-Like Peptide 1; Humans; Leptin; Melanocyte-Stimulating Hormones; Neuropeptide Y; Obesity; Pro-Opiomelanocortin; Receptor, Cannabinoid, CB1; Serotonin; Serotonin Receptor Agonists; Thyroid Hormones | 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 |
The physiology of glucagon-like peptide 1.
Glucagon-like peptide 1 (GLP-1) is a 30-amino acid peptide hormone produced in the intestinal epithelial endocrine L-cells by differential processing of proglucagon, the gene which is expressed in these cells. The current knowledge regarding regulation of proglucagon gene expression in the gut and in the brain and mechanisms responsible for the posttranslational processing are reviewed. GLP-1 is released in response to meal intake, and the stimuli and molecular mechanisms involved are discussed. GLP-1 is extremely rapidly metabolized and inactivated by the enzyme dipeptidyl peptidase IV even before the hormone has left the gut, raising the possibility that the actions of GLP-1 are transmitted via sensory neurons in the intestine and the liver expressing the GLP-1 receptor. Because of this, it is important to distinguish between measurements of the intact hormone (responsible for endocrine actions) or the sum of the intact hormone and its metabolites, reflecting the total L-cell secretion and therefore also the possible neural actions. The main actions of GLP-1 are to stimulate insulin secretion (i.e., to act as an incretin hormone) and to inhibit glucagon secretion, thereby contributing to limit postprandial glucose excursions. It also inhibits gastrointestinal motility and secretion and thus acts as an enterogastrone and part of the "ileal brake" mechanism. GLP-1 also appears to be a physiological regulator of appetite and food intake. Because of these actions, GLP-1 or GLP-1 receptor agonists are currently being evaluated for the therapy of type 2 diabetes. Decreased secretion of GLP-1 may contribute to the development of obesity, and exaggerated secretion may be responsible for postprandial reactive hypoglycemia. Topics: Animals; Diabetes Mellitus; Gastrointestinal Tract; Glucagon-Like Peptide 1; Glucagon-Like Peptide-1 Receptor; Humans; Hypoglycemia; Obesity; Proglucagon; Receptors, Glucagon | 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 |
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 |
Gut hormones ghrelin, PYY, and GLP-1 in the regulation of energy balance [corrected] and metabolism.
The first hormone discovered in the gastrointestinal tract was secretin, isolated from duodenal mucosa. Some years later, two additional gastrointestinal hormones, gastrin and cholecystokinin (CCK), were discovered, but it was not until the 1970s that gastrointestinal endocrinology studies became more prevalent, resulting in the discovery of many more hormones. Here, we examine the role of gut hormones in energy balance regulation and their possible use as pharmaceutical targets for obesity. Topics: Animals; Anti-Obesity Agents; Appetite Regulation; Body Weight; Energy Metabolism; Ghrelin; Glucagon-Like Peptide 1; Glucagon-Like Peptides; Homeostasis; Humans; Obesity; Oxyntomodulin; Peptide Hormones; Peptide YY | 2006 |
Obesity drugs in clinical development.
A number of anti-obesity drugs are currently undergoing clinical development. These include: (i) centrally-acting drugs, such as the noradrenergic and dopaminergic reuptake inhibitor radafaxine, the endocannabinoid antagonist rimonabant, the selective serotonin 5-HT2c agonist APD-356, and oleoyl-estrone; (ii) drugs that target peripheral episodic satiety signals, such as glucagon-like peptide-1 (exenatide, exenatide-LAR and liraglutide), peptide YY (intranasal PYY3-36 and AC-162325) and amylin (pramlintide); (iii) drugs that block fat absorption, such as the novel lipase inhibitors cetilistat and GT-389255; and (iv) a human growth hormone fragment (AOD-9604) that increases adipose tissue breakdown. Of these, only rimonabant has got as far as completing phase III clinical trials. This review will provide an overview of the most prominent drugs currently undergoing clinical development as potential anti-obesity therapies. Topics: Amyloid; Animals; Anti-Obesity Agents; Appetite Depressants; Energy Metabolism; Glucagon-Like Peptide 1; Humans; Islet Amyloid Polypeptide; Obesity; Peptide Fragments; Peptide YY; Receptor, Cannabinoid, CB1; Selective Serotonin Reuptake Inhibitors; Somatostatin | 2006 |
Gut peptides and the regulation of appetite.
There is a growing worldwide epidemic of obesity. Obese people have a higher incidence of type 2 diabetes and cardiovascular disease, and hence present increasing social, financial and health burdens. Weight loss is always difficult to achieve through lifestyle changes alone, and currently licensed anti-obesity drug treatments, such as orlistat and sibutramine, if tolerated, only achieve modest weight loss. Therefore, there is a need to identify more potent pharmacological targets. In the last 10 years, discoveries of new hormones such as leptin and ghrelin, together with greater understanding of previously described hormones such as cholecystokinin (CCK), pancreatic polypeptide (PP), peptide YY (PYY) and glucagon-like peptide 1 (GLP-1), have led to a rapid increase in our knowledge of the regulation of energy balance. Among the most important factors, controlling appetite and satiety are peptide hormones released from the gut. In this paper, we provide a full up-to-date overview of the current state of knowledge of this field, together with the potential of these peptides as drugs, or as other therapeutic targets, in the treatment of obesity. Finally, we propose an integrated model to describe the complex interplay of these hormones in the broader physiology of energy balance. Topics: Appetite Regulation; Cholecystokinin; Energy Metabolism; Gastrointestinal Hormones; Ghrelin; Glucagon-Like Peptide 1; Glucagon-Like Peptides; Humans; Leptin; Obesity; Oxyntomodulin; Peptide Hormones; Peptide YY; Satiation | 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 |
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 |
The role of oxyntomodulin and peptide tyrosine-tyrosine (PYY) in appetite control.
Oxyntomodulin and peptide tyrosine-tyrosine (PYY) are released from intestinal enteroendocrine cells in response to a meal. These circulating hormones are considered to be satiety signals, as they have been found to decrease food intake, body weight and adiposity in rodents. Their effect on energy homeostasis is mediated by the hypothalamus and brainstem, and several studies have demonstrated alterations in neuropeptide signaling within the arcuate nucleus. The weight loss that has been observed in animal models after repeated administration of oxyntomodulin and PYY has led to interest in developing these peptides as antiobesity therapies in humans. Indeed, preliminary studies have found that oxyntomodulin or PYY administration reduces food intake and body weight effectively in overweight human volunteers. This research suggests that modulation of these gut hormones could prove to be effective long-term therapies in the quest to combat the obesity epidemic. Topics: Animals; Appetite Regulation; Brain; Gastrointestinal Tract; Glucagon-Like Peptide 1; Glucagon-Like Peptide-1 Receptor; Humans; Models, Biological; Obesity; Oxyntomodulin; Peptide YY; Receptors, Glucagon; Satiety Response | 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].
Topics: Animals; Gastric Inhibitory Polypeptide; Glucagon-Like Peptide 1; Humans; Insulin; Insulin Secretion; Obesity | 2006 |
Physiology and pathophysiology of glucagon-like peptide-1 (GLP-1): the role of GLP-1 in the pathogenesis of diabetes mellitus, obesity, and stress.
Glucagon-like peptide-1 (GLP-1) is produced both in the human and rat intestine and brain. The release of GLP-1 into the blood is mediated by factors of neural and hormonal origin and is stimulated by the presence of nutrients in the digestive tract, while the enzyme dipeptidyl peptidase IV and the kidneys are responsible for, respectively, the rapid degradation and excretion of the hormone. Peripherally secreted GLP-1 enhances insulin synthesis and release and maintains the normal anatomical status of pancreatic islets. Diminished GLP-1 response to ingested food, associated with attenuated insulin release and glucose intolerance, was found in non-insulin-dependent diabetes mellitus. GLP-1 replacement in diabetic subjects normalized these parameters, thus indicating a role for this peptide in the pathogenesis of type 2 diabetes. GLP-1 might also be involved in the pathophysiology of obesity and stress to some extent. Both peripheral and central GLP-1 are probably involved in the control of feeding centers as an anorexic agent. GLP-1 affects the activity of the hypothalamo-pituitary-adrenal axis both under basal and stress conditions, including taste aversion learning. Hence, GLP-1-dependent pathophysiological mechanisms may participate in the pathogenesis of the most common metabolic and behavioral disorders. Topics: Animals; Diabetes Mellitus; Glucagon; Glucagon-Like Peptide 1; Humans; Obesity; Pancreas; Peptide Fragments; Protein Precursors; Stress, Physiological | 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 |
Gut hormones and the control of appetite.
Obesity is the main cause of premature death in the UK. Worldwide its prevalence is accelerating. It has been hypothesized that a gut nutriment sensor signals to appetite centres in the brain to reduce food intake after meals. Gut hormones have been identified as an important mechanism for this. Ghrelin stimulates, and glucagon like peptide-1, oxyntomodulin, peptide YY (PYY), cholecystokinin and pancreatic polypeptide inhibit, appetite. At physiological postprandial concentrations they can alter food intake markedly in humans and rodents. In addition, in obese humans fasting levels of PYY are suppressed and postprandial release is reduced. Administration of gut hormones might provide a novel and physiological approach in anti-obesity therapy. Here, we summarize some of the recent advances in this field. Topics: Animals; Appetite Regulation; Cholecystokinin; Gastrointestinal Hormones; Ghrelin; Glucagon; Glucagon-Like Peptide 1; Glucagon-Like Peptides; Humans; Leptin; Obesity; Oxyntomodulin; Pancreatic Polypeptide; Peptide Fragments; Peptide Hormones; Peptide YY; 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 |
Gut hormones as peripheral anti obesity targets.
Many peptides are synthesised and released from the gastrointestinal tract. Whilst their roles in regulation of gastrointestinal function have been known for some time, it is now evident that they also influence eating behaviour and thus potential anti obesity targets. Peptide YY (PYY) is released post prandially from the gastrointestinal L-cells with glucagon-like peptide 1 (GLP-1) and oxyntomodulin. Following peripheral administration of PYY 3-36, the circulating form of PYY, to mouse, rat or human there is marked inhibition of food intake. PYY 3-36 is thought to mediate its actions through the NPY Y2 GPCR. Obese subjects have lower basal fasting PYY levels and have a smaller post prandial rise. However, obesity does not appear to be associated with resistance to PYY (as it is with leptin) and exogenous infusion of PYY 3-36 results in a reduction in food intake by 30% in an obese group and 31% in a lean group. GLP-1 or oxyntomodulin, products of the prepreglucagon gene, decrease food intake when administered either peripherally or directly into the CNS. In addition, both have been shown to decrease food intake in humans. These effects are thought to be mediated by the GLP-1 receptor. Ghrelin, a huger hormone produced by the stomach, increases in the circulation following a period of fasting. Administration of ghrelin either peripherally or directly into the CNS increases food intake and chronic administration leads to obesity. Further infusion into normal healthy volunteers increases both food intake and appetite. Ghrelin is thought to act through the growth hormone secretagogue receptor (GHS-R). Obesity is the current major cause of premature death in the UK, killing almost 1000 people a week. Worldwide its prevalence is accelerating. The administration of the naturally occurring gut hormone may offer a long-term therapeutic approach to weight control. Here we consider the therapeutic potential of some gut hormones, and the GPCR's through which they act, in the treatment of obesity. Topics: Animals; Anti-Obesity Agents; Appetite Regulation; Drug Design; Gastrointestinal Hormones; Ghrelin; Glucagon; Glucagon-Like Peptide 1; Glucagon-Like Peptides; Humans; Mice; Obesity; Oxyntomodulin; Pancreatic Polypeptide; Peptide Fragments; Peptide Hormones; Peptide YY; Protein Precursors; Rats; Receptors, G-Protein-Coupled | 2004 |
Modern, new pharmacotherapy for obesity. A gastrointestinal approach.
Topics: Amylases; Androgens; Anti-Obesity Agents; Citrates; Cyclobutanes; Dietary Fats; Fat Substitutes; Fatty Acids; Glucagon; Glucagon-Like Peptide 1; Glucosidases; Human Growth Hormone; Humans; Intestinal Absorption; Lactones; Lipase; Obesity; Orlistat; Peptide Fragments; Protein Precursors; Sucrose | 2004 |
Central pre-proglucagon derived peptides: opportunities for treatment of obesity.
Modern societies have moved from famine to feast and obesity and its co-morbidities now sweep the world as a global epidemic. Numerous scientific laboratories and pharmaceutical companies have taken the challenge and are now exploiting novel molecular targets for treatment of obesity. The pre-proglucagon system constitutes interesting candidates as potential targets for new anti-obesity drugs. In the periphery, pre-proglucagon derived peptides, Glucagon-Like Peptide-1 (GLP-1), Glucagon-Like Peptide-2 (GLP-2) and oxyntomodulin (OXM) are involved in a wide variety of physiological functions, including glucose homeostasis, gastric emptying, intestinal growth, insulin secretion as well as the regulation of food intake. Peripheral administration of GLP-1 derivatives and analogues to both rodents and man have shown promising effects on food intake and body weight suggesting that such therapies constitute potential anti-obesity treatment. In the central nervous system, pre-proglucagon and hence GLP-1, GLP-2 and OXM are exclusively found in a small population of nerve cells in the nucleus of the solitary tract. These constitute a neural pathway linking the "viscero-sensory" brainstem to hypothalamic nuclei involved in energy homeostasis. Intracerebroventricular administration of all of the three derived peptides robustly decrease food intake. It is evident that central GLP-1 agonism probably in combination with GLP-2 and/or OXM agonism constitute a potential pharmacological tool to reduce food intake and maybe also enhance energy expenditure. This and other aspects of the current state of the role of central pre-proglucagon in energy homeostasis are reviewed. Topics: Animals; Behavior, Animal; Central Nervous System; Eating; Glucagon; Glucagon-Like Peptide 1; Glucagon-Like Peptide 2; Glucagon-Like Peptide-1 Receptor; Glucagon-Like Peptides; Humans; Obesity; Oxyntomodulin; Peptide Fragments; Peptides; Proglucagon; Protein Precursors; Receptors, Glucagon | 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 |
Glucagon-like peptide 1 as a regulator of food intake and body weight: therapeutic perspectives.
After ingestion of carbohydrate- and fat-rich meals, the incretin hormone glucagon-like peptide 1 (GLP-1) is secreted from the L-cells in the distal put into the circulation. Its major physiological effect lies in a strongly glucose-dependent stimulation of insulin secretion from pancreatic B-cells. Furthermore, GLP-1 suppresses glucagon secretion, stimulates B-cell neogenesis as well as proinsulin biosynthesis and inhibits gastric emptying and acid secretion. Recently, GLP-1 could be shown to reduce caloric intake and to enhance satiety, most likely via specific receptors within the central nervous system, resulting in reduced weight gain in experimental animals. In nondiabetic and Type 2 diabetic human subjects, exogenous GLP-1 reduces hunger, caloric intake and body weight. Therefore, in addition to its well-characterized antidiabetogenic effect, the anorectic effect may offer GLP-1 a potential in the pharmacotherapy of obesity. It is still unknown whether the GLP-1 effect on caloric intake is sustained after long-term treatment. Furthermore, the exact mechanisms by which the peptide exerts its biological effects have not yet been clarified. Due to the rapid degradation of native GLP-1, its therapeutic application is limited by the short half-life. Therefore, suitable modes of administration are needed in order to reach stable plasma concentrations. The present review aims to describe the role of GLP-1 in the central regulation of feeding and to discuss its possible application in the pharmacotherapy of obesity. Topics: Animals; Body Weight; Eating; Glucagon; Glucagon-Like Peptide 1; Humans; Obesity; Peptide Fragments; Protein Precursors | 2002 |
A meta-analysis of the effect of glucagon-like peptide-1 (7-36) amide on ad libitum energy intake in humans.
Seven studies have now been published pertaining to the acute effect of iv administration of glucagon-like peptide-1 (7-36) amide on ad libitum energy intake. In four of these studies energy intake was significantly reduced following the glucagon-like peptide-1 infusion compared with saline. In the remaining studies, no significant effect of glucagon-like peptide-1 could be shown. Lack of statistical power or low glucagon-like peptide-1 infusion rate may explain these conflicting results. Our aim was to examine the effect of glucagon-like peptide-1 on subsequent energy intake using a data set composed of subject data from previous studies and from two as yet unpublished studies. Secondly, we investigated whether the effect on energy intake is dose dependent and differs between lean and overweight subjects. Raw subject data on body mass index and ad libitum energy intake were collected into a common data set (n = 115), together with study characteristics such as infusion rate, duration of infusion, etc. From four studies with comparable protocol the following subject data were included if available: plasma concentrations of glucagon-like peptide-1, subjective appetite measures, well-being, and gastric emptying rate of a meal served at the start of the glucagon-like peptide-1 infusion. Energy intake was reduced by 727 kJ (95% confidence interval, 548-908 kJ) or 11.7% during glucagon-like peptide-1 infusion. Although the absolute reduction in energy intake was higher in lean (863 kJ) (634-1091 kJ) compared with overweight subjects (487 kJ) (209-764 kJ) (P = 0.05), the relative reduction did not differ between the two groups (13.2% and 9.3%, respectively). Stepwise regression analysis showed that the glucagon-like peptide-1 infusion rate was the only independent predictor of the reduction in energy intake during glucagon-like peptide-1 (7-36) amide infusion (r = 0.4, P < 0.001). Differences in mean plasma glucagon-like peptide-1 concentration on the glucagon-like peptide-1 and placebo day (n = 43) were related to differences in feelings of prospective consumption (r = 0.40, P < 0.01), fullness (r = 0.38, P < 0.05), and hunger (r = 0.26, P = 0.09), but not to differences in ad libitum energy intake. Gastric emptying rate was significantly lower during glucagon-like peptide-1 infusion compared with saline. Finally, well-being was not influenced by the glucagon-like peptide-1 infusion. Glucagon-like peptide-1 infusion reduces energy intake dose dependently in bo Topics: Adult; Appetite; Cross-Over Studies; Dose-Response Relationship, Drug; Eating; Energy Metabolism; Gastric Emptying; Glucagon; Glucagon-Like Peptide 1; Glucagon-Like Peptides; Humans; Hunger; Infusions, Intravenous; Injections, Intravenous; Male; Obesity; Peptide Fragments; Randomized Controlled Trials as Topic; Satiety Response | 2001 |
Is there appetite after GLP-1 and PACAP?
Anitobesity drugs must increase the sensitivity of the hypothalamic satiety center towards leptin and antagonize the synthesis and action of NPY. The array of pharmacologic tools available is vast and presently ineffective. Among peptide analogs considered for evaluation [NPY-5 antagonists and CCK-A, bombesin, amylin and melanocyte-stimulating hormone-4 (or melanin-concentrating hormone?) agonists], is there a place for GLP-1 and PACAP? GLP-1 receptors present in ARC, PVN, VMN, and SON are the target for both central and blood-borne GLP-1 in those hypothalamic neurons endowed with GLUT-2 and glucokinase. GLP-1, hypersecreted by L-cells after a meal, is a potent insulinotropic agent and, together with glucose, reduces food intake and induces c-fos in the ARC. PACAP is present in the ARC, PVN, and SCH, and its hypothalamic type I receptor elevates cAMP and inositol triphosphate in the PVN, where it may perhaps antagonize NPY-induced food intake and hyperinsulinemia. However, irrelevant neuroendocrine, autonomic, and circadian functions are also activated by this peptide, making it a less than ideal base on which to build an obesity treatment. Topics: Animals; Appetite; Appetite Depressants; Digestive System Physiological Phenomena; Glucagon; Glucagon-Like Peptide 1; Glucagon-Like Peptide-1 Receptor; Homeostasis; Humans; Hypothalamus; Islets of Langerhans; Models, Biological; Neuropeptides; Obesity; Peptide Fragments; Pituitary Adenylate Cyclase-Activating Polypeptide; Protein Precursors; Receptors, Glucagon | 1998 |
Control of appetite--the role of glucagon-like peptide-1 (7-36) amide.
Topics: Adipocytes; Animals; Appetite Regulation; Glucagon; Glucagon-Like Peptide 1; Glucagon-Like Peptides; Humans; Insulin; Neurotransmitter Agents; Obesity; Peptide Fragments | 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 |
181 trial(s) available for glucagon-like-peptide-1 and Obesity
Article | Year |
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Factors associated with successful weight loss after liraglutide treatment for obesity.
To identify patient factors, including gastrointestinal functions, that are predictive or associated with weight loss in response to once-daily 3 mg liraglutide administered subcutaneously (SQ) or placebo in obesity.. One hundred and thirty-six obese adults (87% female) were randomized in a placebo-controlled, 16-week trial of liraglutide, escalated to 3 mg administered SQ daily. Gastrointestinal functions were measured at baseline and 16 weeks: gastric emptying of solids (GET. Slower GET Topics: Adult; Double-Blind Method; Female; Gastric Emptying; Glucagon-Like Peptide 1; Humans; Liraglutide; Male; Obesity; Weight Loss | 2023 |
Glucagon-like peptide-1/glucagon receptor agonism associates with reduced metabolic adaptation and higher fat oxidation: A randomized trial.
This study tested the hypothesis that treatment with the glucagon-like peptide-1/glucagon receptor agonist SAR425899 would lead to a smaller decrease in sleeping metabolic rate (SMR; kilocalories/day) than expected from the loss of lean and fat mass (metabolic adaptation).. This Phase 1b, double-blind, randomized, placebo-controlled study was conducted at two centers in inpatient metabolic wards. Thirty-five healthy males and females with overweight and obesity (age = 36.5 ± 7.1 years) were randomized to a calorie-reduced diet (-1000 kcal/d) and escalating doses (0.06-0.2 mg/d) of SAR425899 (n = 17) or placebo (n = 18) for 19 days. SMR was measured by whole-room calorimetry.. Both groups lost weight (-3.68 ± 1.37 kg placebo; -4.83 ± 1.44 kg SAR425899). Those treated with SAR425899 lost more weight, fat mass, and fat free mass (p < 0.05) owing to a greater achieved energy deficit than planned. The SAR425899 group had a smaller reduction in body composition-adjusted SMR (p = 0.002) as compared with placebo, but not 24-hour energy expenditure. Fat oxidation and ketogenesis increased in both groups, with significantly greater increases with SAR425899 (p < 0.05).. SAR425899 led to reduced selective metabolic adaptation and increased lipid oxidation, which are believed to be beneficial for weight loss and weight-loss maintenance. Topics: Adult; Energy Metabolism; Female; Glucagon-Like Peptide 1; Humans; Male; Obesity; Overweight; Oxidation-Reduction; Receptors, Glucagon; Weight Loss | 2023 |
Tripeptide gut hormone infusion does not alter food preferences or sweet taste function in volunteers with obesity and prediabetes/diabetes but promotes restraint eating: A secondary analysis of a randomized single-blind placebo-controlled study.
To investigate whether the elevation in postprandial concentrations of the gut hormones glucagon-like peptide-1 (GLP-1), oxyntomodulin (OXM) and peptide YY (PYY) accounts for the beneficial changes in food preferences, sweet taste function and eating behaviour after Roux-en-Y gastric bypass (RYGB).. This was a secondary analysis of a randomized single-blind study in which we infused GLP-1, OXM, PYY (GOP) or 0.9% saline subcutaneously for 4 weeks in 24 subjects with obesity and prediabetes/diabetes, to replicate their peak postprandial concentrations, as measured at 1 month in a matched RYGB cohort (ClinicalTrials.gov NCT01945840). A 4-day food diary and validated eating behaviour questionnaires were completed. Sweet taste detection was measured using the method of constant stimuli. Correct sucrose identification (corrected hit rates) was recorded, and sweet taste detection thresholds (EC50s: half maximum effective concencration values) were derived from concentration curves. The intensity and consummatory reward value of sweet taste were assessed using the generalized Labelled Magnitude Scale.. Mean daily energy intake was reduced by 27% with GOP but no significant changes in food preferences were observed, whereas a reduction in fat and increase in protein intake were seen post-RYGB. There was no change in corrected hit rates or detection thresholds for sucrose detection following GOP infusion. Additionally, GOP did not alter the intensity or consummatory reward value of sweet taste. A significant reduction in restraint eating, comparable to the RYGB group was observed with GOP.. The elevation in plasma GOP concentrations after RYGB is unlikely to mediate changes in food preferences and sweet taste function after surgery but may promote restraint eating. Topics: Food Preferences; Gastric Bypass; Gastrointestinal Hormones; Glucagon-Like Peptide 1; Humans; Obesity; Peptide YY; Prediabetic State; Single-Blind Method; Sucrose; Taste; Volunteers | 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 |
Triple-Hormone-Receptor Agonist Retatrutide for Obesity - A Phase 2 Trial.
Retatrutide (LY3437943) is an agonist of the glucose-dependent insulinotropic polypeptide, glucagon-like peptide 1, and glucagon receptors. Its dose-response relationships with respect to side effects, safety, and efficacy for the treatment of obesity are not known.. We conducted a phase 2, double-blind, randomized, placebo-controlled trial involving adults who had a body-mass index (BMI, the weight in kilograms divided by the square of the height in meters) of 30 or higher or who had a BMI of 27 to less than 30 plus at least one weight-related condition. Participants were randomly assigned in a 2:1:1:1:1:2:2 ratio to receive subcutaneous retatrutide (1 mg, 4 mg [initial dose, 2 mg], 4 mg [initial dose, 4 mg], 8 mg [initial dose, 2 mg], 8 mg [initial dose, 4 mg], or 12 mg [initial dose, 2 mg]) or placebo once weekly for 48 weeks. The primary end point was the percentage change in body weight from baseline to 24 weeks. Secondary end points included the percentage change in body weight from baseline to 48 weeks and a weight reduction of 5% or more, 10% or more, or 15% or more. Safety was also assessed.. We enrolled 338 adults, 51.8% of whom were men. The least-squares mean percentage change in body weight at 24 weeks in the retatrutide groups was -7.2% in the 1-mg group, -12.9% in the combined 4-mg group, -17.3% in the combined 8-mg group, and -17.5% in the 12-mg group, as compared with -1.6% in the placebo group. At 48 weeks, the least-squares mean percentage change in the retatrutide groups was -8.7% in the 1-mg group, -17.1% in the combined 4-mg group, -22.8% in the combined 8-mg group, and -24.2% in the 12-mg group, as compared with -2.1% in the placebo group. At 48 weeks, a weight reduction of 5% or more, 10% or more, and 15% or more had occurred in 92%, 75%, and 60%, respectively, of the participants who received 4 mg of retatrutide; 100%, 91%, and 75% of those who received 8 mg; 100%, 93%, and 83% of those who received 12 mg; and 27%, 9%, and 2% of those who received placebo. The most common adverse events in the retatrutide groups were gastrointestinal; these events were dose-related, were mostly mild to moderate in severity, and were partially mitigated with a lower starting dose (2 mg vs. 4 mg). Dose-dependent increases in heart rate peaked at 24 weeks and declined thereafter.. In adults with obesity, retatrutide treatment for 48 weeks resulted in substantial reductions in body weight. (Funded by Eli Lilly; ClinicalTrials.gov number, NCT04881760.). Topics: Adult; Anti-Obesity Agents; Body Mass Index; Double-Blind Method; Female; Gastric Inhibitory Polypeptide; Glucagon-Like Peptide 1; Humans; Injections, Subcutaneous; Male; Obesity; Receptors, Glucagon; Treatment Outcome; Weight Loss | 2023 |
The effects of sodium butyrate supplementation on the expression levels of PGC-1α, PPARα, and UCP-1 genes, serum level of GLP-1, metabolic parameters, and anthropometric indices in obese individuals on weight loss diet: a study protocol for a triple-blind
Obesity is a multifaceted disease characterized by an abnormal accumulation of adipose tissue. Growing evidence has proposed microbiota-derived metabolites as a potential factor in the pathophysiology of obesity and related metabolic conditions over the last decade. As one of the essential metabolites, butyrate affects several host cellular mechanisms related to appetite sensations and weight control. However, the effects of butyrate on obesity in humans have yet to be studied. Thus, the present study was aimed to evaluate the effects of sodium butyrate (SB) supplementation on the expression levels of peroxisome proliferator activated-receptor (PPAR) gamma coactivator-1α (PGC-1α), PPARα and uncoupling protein 1 (UCP1) genes, serum level of glucagon-like peptide (GLP1), and metabolic parameters, as well as anthropometric indices in obese individuals on a weight loss diet.. This triple-blind randomized controlled trial (RCT) will include 50 eligible obese subjects aged between 18 and 60 years. Participants will be randomly assigned into two groups: 8 weeks of SB (600 mg/day) + hypo-caloric diet or placebo (600 mg/day) + hypo-caloric diet. At weeks 0 and 8, distinct objectives will be pursued: (1) PGC-1α, PPARα, and UCP1 genes expression will be evaluated by real-time polymerase chain reaction; (2) biochemical parameters will be assayed using enzymatic methods; and (3) insulin and GLP1 serum level will be assessed by enzyme-linked immunosorbent assay kit.. New evidence from this trial may help fill the knowledge gap in this realm and facilitate multi-center clinical trials with a substantially larger sample size.. Iranian Registry of Clinical Trials: IRCT20190303042905N2 . Registered on 31 January 2021. Topics: Adolescent; Adult; Butyric Acid; Diet, Reducing; Dietary Supplements; Glucagon-Like Peptide 1; Humans; Middle Aged; Obesity; PPAR alpha; Randomized Controlled Trials as Topic; Transcription Factors; Uncoupling Protein 1; Young Adult | 2023 |
No effect of multi-strain probiotic supplementation on metabolic and inflammatory markers and newborn body composition in pregnant women with obesity: Results from a randomized, double-blind placebo-controlled study.
Modulation of the gut microbiome composition with probiotics may have beneficial metabolic effects in pregnant women with obesity. The aim was to investigate the effect of probiotic supplementation during pregnancy on metabolic and inflammatory markers and the body composition of the offspring.. In this study of pregnant women with obesity and their newborns, there was no effect of probiotic supplementation in mothers or babies on metabolic or inflammatory biomarkers or on body composition of offspring. This study was registered at clinicaltrials.gov as NCT02508844. Topics: Biomarkers; Body Composition; Double-Blind Method; Female; Glucagon; Glucagon-Like Peptide 1; Humans; Infant, Newborn; Obesity; Pregnancy; Pregnant Women; Probiotics | 2023 |
Liraglutide restores impaired associative learning in individuals with obesity.
Survival under selective pressure is driven by the ability of our brain to use sensory information to our advantage to control physiological needs. To that end, neural circuits receive and integrate external environmental cues and internal metabolic signals to form learned sensory associations, consequently motivating and adapting our behaviour. The dopaminergic midbrain plays a crucial role in learning adaptive behaviour and is particularly sensitive to peripheral metabolic signals, including intestinal peptides, such as glucagon-like peptide 1 (GLP-1). In a single-blinded, randomized, controlled, crossover basic human functional magnetic resonance imaging study relying on a computational model of the adaptive learning process underlying behavioural responses, we show that adaptive learning is reduced when metabolic sensing is impaired in obesity, as indexed by reduced insulin sensitivity (participants: N = 30 with normal insulin sensitivity; N = 24 with impaired insulin sensitivity). Treatment with the GLP-1 receptor agonist liraglutide normalizes impaired learning of sensory associations in men and women with obesity. Collectively, our findings reveal that GLP-1 receptor activation modulates associative learning in people with obesity via its central effects within the mesoaccumbens pathway. These findings provide evidence for how metabolic signals can act as neuromodulators to adapt our behaviour to our body's internal state and how GLP-1 receptor agonists work in clinics. Topics: Female; Glucagon-Like Peptide 1; Glucagon-Like Peptide-1 Receptor; Humans; Insulin Resistance; Liraglutide; Male; Obesity | 2023 |
Impact of isoenergetic intake of irregular meal patterns on thermogenesis, glucose metabolism, and appetite: a randomized controlled trial.
Evidence is emerging that interdaily meal pattern variability potentially affects response such as thermic effect of food (TEF), macronutrient metabolism, and appetite.. To investigate the effect of irregular meal pattern on TEF, glucose, insulin, lipid profile, and appetite regulation in women who are overweight or with obesity and confirmed insulin resistance.. In a randomized crossover trial, 9 women [mean ± SD BMI (in kg/m2): 33.3 ± 3.1] with confirmed insulin resistance consumed a regular (14 d; 6 meals/d) and an irregular (14 d; 3-9 meals/d) meal pattern separated by a 14-d washout interval. Identical foods were provided during the interventions, and at the start and end of each meal pattern, participants attended the laboratory after an overnight fast. Energy expenditure, glucose, insulin, lipids, adiponectin, leptin, glucagon-like peptide 1 (GLP-1), peptide YY (PYY), and ghrelin were measured at baseline and for 3 h after consumption of a test drink, after which an ad libitum test meal was offered. Subjective appetite ratings were recorded before and after the test drink, after the ad libitum meal, and during the intervention. Continuous interstitial glucose monitoring was undertaken for 7 consecutive days during each intervention.. TEF (over 3 h) was significantly lower postirregular intervention compared with postregular (97.7 ± 19.2 kJ*3 h in postregular visit and 76.7 ± 35.2 kJ*3 h in postirregular visit, paired t test, P = 0.048). Differences in HOMA-IR between the 2 interventions (3.3 ± 1.7 and 3.6 ± 1.6 in postregular and postirregular meal pattern, respectively) were not significant. Net incremental AUC for GLP-1 concentrations (over 3 h) for the postregular meal pattern were higher (864.9 ± 456.1 pmol/L*3 h) than the postirregular meal pattern (487.6 ± 271.7 pmol/L*3 h, paired t test, P = 0.005).. Following a 14-d period of an irregular meal pattern, TEF was significantly less than following a regular meal pattern, potentially compromising weight management if sustained long term. This study was registered at www.clinicaltrials.gov as NCT02582606. Topics: Adiponectin; Adolescent; Adult; Appetite; Blood Glucose; Blood Glucose Self-Monitoring; Energy Metabolism; Feeding Behavior; Female; Ghrelin; Glucagon-Like Peptide 1; Humans; Insulin; Insulin Resistance; Leptin; Lipids; Meals; Middle Aged; Obesity; Overweight; Peptide YY; Thermogenesis; Young Adult | 2022 |
Interrupting Prolonged Sitting with Intermittent Walking Increases Postprandial Gut Hormone Responses.
Continuous exercise can increase postprandial gut hormone such as glucagon-like peptide 1 (GLP-1) and peptide YY (PYY) responses, but it is unknown whether interrupting prolonged sitting with intermittent walking elicits this effect.. Ten participants with central overweight/obesity (7 men and 3 postmenopausal women, 51 ± 5 yr; mean ± SD) completed a randomized crossover study in which they consumed breakfast and lunch in the laboratory while either sitting continuously for the entire 5.5-h period (SIT) or the prolonged sitting interrupted every 20 min by walking briskly (6.4 km·h-1) for 2 min (BREAKS). Blood samples were collected at regular intervals to examine postprandial plasma GLP-1, PYY, and glucose-dependent insulinotropic polypeptide concentrations. Adipose tissue samples were collected at baseline and at the end of the trials to examine changes in net dipeptidyl peptidase 4 secretion from primary explants.. Mean (95% confidence interval) postprandial GLP-1 and PYY incremental area under curve values were elevated by 26% and 31% in the BREAKS trial versus SIT (8.4 [0.7, 16.1] vs 6.7 [-0.8, 14.2], P = 0.001, and 26.9 [8.1, 45.6] vs 20.4 [5.1, 35.8] nmol·330 min·L-1, P = 0.024, respectively) but without any such effect on glucose-dependent insulinotropic polypeptide (P = 0.076) or net adipose tissue dipeptidyl peptidase 4 secretion (P > 0.05).. Interrupting prolonged sitting with regular short bouts of brisk walking increases postprandial GLP-1 and PYY concentrations in healthy middle-age men and women with central adiposity. Topics: Blood Glucose; Cross-Over Studies; Dipeptidyl Peptidase 4; Female; Glucagon-Like Peptide 1; Humans; Insulin; Male; Middle Aged; Obesity; Obesity, Abdominal; Peptide YY; Postprandial Period; Walking | 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 |
Sperm count is increased by diet-induced weight loss and maintained by exercise or GLP-1 analogue treatment: a randomized controlled trial.
Does diet-induced weight loss improve semen parameters, and are these possible improvements maintained with sustained weight loss?. An 8-week low-calorie diet-induced weight loss was associated with improved sperm concentration and sperm count, which were maintained after 1 year in men who maintained weight loss.. Obesity is associated with impaired semen quality. Weight loss improves metabolic health in obesity, but there is a lack of knowledge on the acute and long-term effects of weight loss on semen parameters.. This is a substudy of men with obesity enrolled in a randomized, controlled, double-blinded trial (the S-LITE trial). The trial was conducted between August 2016 and November 2019. A total of 56 men were included in the study and assigned to an initial 8-week low-calorie diet (800 kcal/day) followed by randomization to 52 weeks of either: placebo and habitual activity (placebo), exercise training and placebo (exercise), the Glucagon Like Peptide 1 (GLP-1) analogue liraglutide and habitual activity (liraglutide) or liraglutide in combination with exercise training (combination).. Inclusion criteria were men who delivered semen samples, 18 to 65 years of age, and a body mass index between 32 and 43 kg/m2, but otherwise healthy. The study was carried out at Hvidovre Hospital and at the University of Copenhagen, and the participants were from the Greater Copenhagen Area. We assessed semen parameters and anthropometrics and collected blood samples before (T0), after the 8-week low-calorie dietary intervention (T1), and after 52 weeks (T2).. The men lost on average 16.5 kg (95% CI: 15.2-17.8) body weight during the low-calorie diet, which increased sperm concentration 1.49-fold (95% CI: 1.18-1.88, P < 0.01) and sperm count 1.41-fold (95% CI: 1.07-1.87, P < 0.01). These improvements were maintained for 52 weeks in men who maintained the weight loss, but not in men who regained weight. Semen volume, sperm motility and motile sperm count did not change.. The S-LITE trial was a randomized controlled trial of weight loss maintenance. Analysis of semen was preregistered to explore the effects of weight loss and weight loss maintenance on semen parameters, but definite inferences cannot be made.. This study shows that sperm concentration and sperm count were improved after a diet-induced weight loss in men with obesity. Our findings indicate that either or both liraglutide and exercise as weight maintenance strategies may be used to maintain the improvements in sperm concentration and count.. This work is supported by an excellence grant from the Novo Nordisk Foundation (NNF16OC0019968), a Challenge Programme Grant from the Novo Nordisk Foundation (NNF18OC0033754) and a grant from Helsefonden. The Novo Nordisk Foundation Center for Basic Metabolic Research is an independent research centre at the University of Copenhagen, partially funded by an unrestricted donation from the Novo Nordisk Foundation (NNF18CC0034900). Saxenda (liraglutide) and placebo pens were provided by Novo Nordisk. Cambridge Weight Plan diet products for the 8-week low-calorie diet were provided by Cambridge Weight Plan. E.A.: shareholder, employee of ExSeed Health Ltd. Grant Recipient from ExSeed Health Ltd and listed on Patents planned, issued or pending with ExSeed Health Ltd; J.J.H.: consultant for Eli Lilly A/S and Novo Nordisk A/S. Lecture fees for Novo Nordisk A/S. Listed on Patents planned, issued or pending with the University of Copenhagen, Advocacy group for Antag Therapeutics and Bainan Biotech; S.M.: lecture fees for Novo Nordisk A/S. Recipient of Support for attending meetings from Novo Nordisk A/S. Advisory boards of Novo Nordisk A/S; Sanofi Aventis and Merck Sharp & Dohme. S.S.T.: research grant recipient Novo Nordisk. The remaining authors have no conflicts of interest to declare.. The trial was approved by the Ethical Committee of the Capital Region of Denmark (H-16027082) and the Danish Medicines Agency (EudraCT Number: 2015-005585-32). ClinicalTrials.gov identifier (NCT number): NCT04122716.. 11 May 2016.. August 2016. Topics: Diet, Reducing; Exercise; Female; Glucagon-Like Peptide 1; Humans; Liraglutide; Male; Obesity; Semen; Semen Analysis; Sperm Count; Sperm Motility; Spermatozoa; Weight Loss | 2022 |
Effects of liraglutide on gastrointestinal functions and weight in obesity: A randomized clinical and pharmacogenomic trial.
This study aimed to determine the effects of a long-acting glucagon-like peptide-1 (GLP-1) receptor agonist, liraglutide, and placebo subcutaneously over 16 weeks on weight and gastric functions and to evaluate associations of single-nucleotide polymorphisms in GLP1R (rs6923761) and TCF7L2 (rs7903146) with effects of liraglutide.. The study conducted a randomized, parallel-group, placebo-controlled, 16-week trial of liraglutide, escalated to 3 mg subcutaneously daily in 136 otherwise healthy adults with obesity. Weight, gastric emptying of solids (GES), gastric volumes, satiation, and body composition measured at baseline and after treatment were compared in two treatment groups using analysis of covariance.. Liraglutide, 3 mg, induces weight loss with delay in GES T Topics: Adult; Double-Blind Method; Glucagon-Like Peptide 1; Glucagon-Like Peptide-1 Receptor; Humans; Hypoglycemic Agents; Liraglutide; Obesity; Pharmacogenetics; Weight Loss | 2022 |
Circulating levels of five proglucagon-derived peptides in response to intravenous or oral glucose or lipids and to a mixed-meal in subjects with normal weight, overweight, and obesity.
Proglucagon-derived peptides (PGDPs) secreted by the gut and pancreas play a major role in metabolism. We measured concentrations of five PGDPs in response to per os (PO) or intravenous (IV) glucose or lipid intake and a mixed meal test (MMT) consumed by subjects with normal weight, overweight or obesity.. GLP-1, oxyntomodulin and glicentin (gut-secreted PGDPs) and glucagon and MPGF (pancreas-secreted PGDPs) were assessed in: (a) 32 subjects receiving PO or IV glucose, lipids or water over 6 h, (b) 33 subjects with normal weight, overweight or obesity who consumed a MMT.. (a) GLP-1, oxyntomodulin, glicentin and glucagon levels increase more profoundly and persistently after lipids PO (2.5 g/kg) than glucose PO (2.5 g/kg) or IV lipids (Intralipid/Liposyn II 20% at 0.35 ml/kg/h and Intralipid/Liposyn II 20% at 0.83 ml/kg/h for 6 h) or IV glucose (10% glucose at 3.6 ml/kg/h for 6 h). Oxyntomodulin and glicentin increased more than GLP-1 in response to lipids PO. MPGF levels decrease in response to glucose PO or IV indicating a shift towards preferential production of gut-secreted peptides. (b) Fasting and postprandial areas under the curve (AUCs) after MMT of GLP-1, MPGF and glucagon levels correlated positively with BMI. The fasting levels of glucagon and MPGF were elevated in obesity and remained elevated after the MMT.. Circulating levels of PGDPs are differentially regulated by body weight, the type of macronutrients administered and the respective route of administration. Mechanistic studies are needed to define the exact mechanisms underlying this regulation.. Study 1 has the NCT01520454 and the NCT04888325 number in ClinicalTrials.gov. Study 2 has the number NCT01495754 in ClinicalTrials.gov. Topics: Glicentin; Glucagon; Glucagon-Like Peptide 1; Glucose; Humans; Lipids; Obesity; Overweight; Oxyntomodulin; Peptides; Proglucagon | 2022 |
The Effect of Short-term Mediterranean-DASH Intervention for Neurodegenerative Delay (MIND) Diet on Hunger Hormones, Anthropometric Parameters, and Brain Structures in Middle-aged Overweight and Obese Women: A Randomized Controlled Trial.
The rising prevalence of obesity, as well as its detrimental effects on the brain, has drawn attention to specific dietary patterns. This study aimed to examine the effect of the Mediterranean-DASH Intervention for Neurodegenerative Delay (MIND) pattern on anthropometric parameters, hunger hormones, and brain structures in overweight and obese women.. This randomized trial was conducted in Shiraz between October 2018 and March 2019. We analyzed 37 healthy women with a mean age of 48±5.38 years and a Body Mass Index (BMI) of 32±0.69 Kg/m. A more significant weight reduction (P<0.0001), BMI (P<0.0001), percentage of body fat (P=0.03), waist circumference (P=0.01), and Leptin concentration (P=0.03) were found in the MIND diet group. The results also showed a significant increase in Ghrelin (P=0.002) and GLP-1 (P=0.01) levels in the MIND diet group. The findings revealed no differences in the whole and regional brain structures between the two groups. Topics: Adult; Brain; Female; Ghrelin; Glucagon-Like Peptide 1; Humans; Hunger; Leptin; Middle Aged; Obesity; Overweight | 2022 |
Decoy bypass for appetite suppression in obese adults: role of synergistic nutrient sensing receptors GPR84 and FFAR4 on colonic endocrine cells.
Colonic enteroendocrine cells (EECs) store and release potent anorectic hormones that are key regulators of satiety. EECs express multiple nutrient sensing receptors, particularly for medium-chain fatty acids (MCFAs): GPR84 and FFAR4. Here we show a non-surgical approach with targeted colonic delivery of MCFA, which induces EEC and neuronal activation leading to anorectic effects.. A randomised, double-blind, placebo-controlled, cross-over study was performed in obese adults given combined GPR84 and FFAR4 agonists in colonic release capsules before meals. We measured serum hormones, energy intake and appetite perception. Cell type, activation by agonists and hormone/serotonin release were determined in human colonic explants. Mouse colonic afferent nerve responses to nutrients/mediators were recorded electrophysiologically.. Subjects receiving GPR84 and FFAR4 agonists had reduced overall calorific intake and increased postprandial levels of PYY versus placebo. Receptors including GPR84 and FFAR4 were coexpressed on human colonic EEC. Activation of GPR84 exclusively induced intracellular pERK, whereas FFAR4 selectively activated pCaMKII. Coactivation of GPR84 and FFAR4 induced both phosphoproteins, and superadditive release of GLP-1 and PYY. Nutrients and hormones convergently activated murine colonic afterent nerves via GLP-1, Y2 and 5-HT3 receptors.. Colonic GPR84 and FFAR4 agonists reduce energy intake and increase postprandial PYY in obese adults. Human colonic EECs coexpress these receptors, which activate cells via parallel intracellular pathways and synergistically evoke hormone release. Further synergism occurs in sensory nerve responses to MCFA and EEC mediators. Thus, synergistic activation of colonic endocrine cells via nutrient receptors is an important target for metabolic regulation.. NCT04292236. Topics: Animals; Appetite; Appetite Depressants; Cross-Over Studies; Enteroendocrine Cells; Glucagon-Like Peptide 1; Humans; Mice; Nutrients; Obesity; Receptors, G-Protein-Coupled | 2022 |
Effects of Delayed-Release Olive Oil and Hydrolyzed Pine Nut Oil on Glucose Tolerance, Incretin Secretion and Appetite in Humans.
To investigate the potential synergistic effects of olive oil releasing 2-oleoylglycerol and hydrolyzed pine nut oil containing 20% pinolenic acid on GLP-1 secretion, glucose tolerance, insulin secretion and appetite in healthy individuals, when delivered to the small intestine as potential agonists of GPR119, FFA1 and FFA4.. Nine overweight/obese individuals completed three 6-h oral glucose tolerance tests (OGTTs) in a crossover design. At -30 min, participants consumed either: no oil, 6 g of hydrolyzed pine nut oil (PNO-FFA), or a combination of 3 g hydrolyzed pine nut oil and 3 g olive oil (PNO-OO) in delayed-release capsules. Repeated measures of glucose, insulin, C-peptide, GLP-1, GIP, ghrelin, subjective appetite and gastrointestinal tolerability were done.. PNO-FFA augmented GLP-1 secretion from 0-360 min compared to no oil and PNO-OO (. In support of previous findings, 6 g of delayed-release hydrolyzed pine nut oil enhanced postprandial GLP-1 secretion and reduced appetite. However, no synergistic effect of combining hydrolyzed pine nut oil and olive oil on GLP-1 secretion was observed. These results need further evaluation in long-term studies including effects on bodyweight and insulin sensitivity. Topics: Appetite; Blood Glucose; Cross-Over Studies; Delayed-Action Preparations; Dietary Fats, Unsaturated; Dietary Supplements; Female; Glucagon-Like Peptide 1; Glucose Tolerance Test; Humans; Incretins; Insulin; Male; Middle Aged; Nuts; Obesity; Olive Oil; Overweight; Pinus; Plant Oils; Postprandial Period | 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 |
Appetite-Regulating Hormones Are Reduced After Oral Sucrose vs Glucose: Influence of Obesity, Insulin Resistance, and Sex.
Fructose compared to glucose has adverse effects on metabolic function, but endocrine responses to oral sucrose vs glucose is not well understood.. We investigated how oral sucrose vs glucose affected appetite-regulating hormones, and how biological factors (body mass index [BMI], insulin sensitivity, sex) influence endocrine responses to these 2 types of sugar.. Sixty-nine adults (29 men; 23.22 ± 3.74 years; BMI 27.03 ± 4.96 kg/m2) completed the study. On 2 occasions, participants consumed 300-mL drinks containing 75 g of glucose or sucrose. Blood was sampled at baseline, 10, 35, and 120 minutes post drink for plasma glucose, insulin, glucagon-like peptide (GLP-1)(7-36), peptide YY (PYY)total, and acyl-ghrelin measures. Hormone levels were compared between conditions using a linear mixed model. Interaction models were performed, and results were stratified to assess how biological factors influence endocrine responses.. Sucrose vs glucose ingestion provoked a less robust rise in glucose (P < .001), insulin (P < .001), GLP-1 (P < .001), and PYY (P = .02), whereas acyl-ghrelin suppression was similar between the sugars. We found BMI status by sugar interactions for glucose (P = .01) and PYY (P = .03); obese individuals had smaller increases in glucose and PYY levels after consuming sucrose vs glucose. There were interactions between insulin sensitivity and sugar for glucose (P = .003) and insulin (P = .04), and a sex by sugar interaction for GLP-1 (P = .01); men demonstrated smaller increases in GLP-1 in response to oral sucrose vs glucose.. Sucrose is less efficient at signaling postprandial satiation than glucose, and biological factors influence differential hormone responses to sucrose vs glucose consumption. Topics: Administration, Oral; Adolescent; Adult; Appetite; Appetite Regulation; Blood Glucose; Body Mass Index; Down-Regulation; Eating; Female; Ghrelin; Glucagon-Like Peptide 1; Glucose; Glucose Tolerance Test; Humans; Insulin Resistance; Male; Obesity; Peptide YY; Satiation; Sex Characteristics; South Carolina; Sucrose; Young Adult | 2021 |
Reduced postprandial bone resorption and greater rise in GLP-1 in overweight and obese individuals after an α-glucosidase inhibitor: a double-blinded randomized crossover trial.
When taken with a meal, α-glucosidase inhibitors (α-GI) reduce the rise in postprandial glucose and increase glucagon-like peptide-1 (GLP-1), and this may lower bone turnover. In this study, a salacinol-type α-GI increased GLP-1 and markedly reduced postprandial bone resorption compared to placebo, suggesting it could have implications for bone health.. Animal and clinical trials indicate that α-glucosidase inhibitors attenuate postprandial glycemic indices and increase secretion of GLP-1. In addition, GLP-1 acts on bone by inhibiting resorption. The goal in this study was to determine if a salacinol α-GI alters postprandial bone turnover and can be explained by changes in serum GLP-1.. In this double-blind, placebo-controlled crossover study, healthy overweight/obese adults (body mass index 29.0 ± 3.8 kg/m. Compared to placebo, SC attenuated the bone resorption marker, CTX, at 60, 90, and 120 min (p < 0.05) after the meal, and decreased osteocalcin, at 180 min (p < 0.05). As expected, SC attenuated the postprandial rise in glucose compared with placebo, whereas GLP-1 was increased at 60 min (p < 0.05) with SC. Serum GLP-1 explained 41% of the variance for change in postprandial CTX (p < 0.05).. This study indicates that attenuating postprandial glycemic indices, with an α-GI, markedly decreases postprandial bone resorption and can be explained by the rise in GLP-1. Future studies should determine whether longer term α-GI use benefits bone health. Topics: Adult; Animals; Blood Glucose; Bone Resorption; Cross-Over Studies; Double-Blind Method; Glucagon-Like Peptide 1; Glycoside Hydrolase Inhibitors; Humans; Insulin; Obesity; Overweight | 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 |
Six-month changes in ghrelin and glucagon-like peptide-1 with weight loss are unrelated to long-term weight regain in obese older adults.
Weight loss (WL) and subsequent regain are complex physiologic processes, and our understanding of the hormonal changes associated with these processes continues to evolve. We aimed to examine the effects of behavioral WL on 6-month changes in ghrelin and GLP-1 and evaluate the effects of these changes in gut hormones on weight regain among older adults.. One hundred seventy-seven obese (BMI: 33.5 (3.5) kg/m. There was no differential treatment effect on change in either gut hormone, however, there was a significant time effect across all groups (p < 0.001), with increases in ghrelin (∆ = +106.77 pg/ml; 95% CI = + 84.82, +128.71) and decreases in GLP-1 (∆ = -4.90 pM; 95% CI = -6.27, -3.51) at 6-month. Ratings on the PFS decreased from baseline to 6-month and there was significant loss of weight from baseline to either 6- or 18-month, ∆ = -7.96 kg; 95% CI = -7.95, -8.78 and ∆ = -7.80 kg; 95% CI = -8.93, -6.65, respectively (p < 0.001). Changes in ghrelin and GLP-1 at 6-month did not predict weight regain from 6- to 18-month.. Among older adults with obesity and cardiometabolic disease, the intensive phase of dietary WL results in increasing levels of ghrelin and decreasing levels of GLP-1 that are unrelated to weight regain a year later. Registered with ClinicalTrials.gov (NCT01547182). Topics: Aged; Exercise Therapy; Female; Ghrelin; Glucagon-Like Peptide 1; Humans; Male; Middle Aged; North Carolina; Obesity; Weight Gain; Weight Loss | 2021 |
High protein diet leads to prediabetes remission and positive changes in incretins and cardiovascular risk factors.
High Protein diets may be associated with endocrine responses that favor improved metabolic outcomes. We studied the response to High Protein (HP) versus High Carbohydrate (HC) Diets in terms of incretin hormones GLP-1 and GIP, the hunger hormone ghrelin and BNP, which is associated with cardiac function. We hypothesized that HP diets induce more pronounced release of glucose lowering hormones, suppress hunger and improve cardiac function.. 24 obese women and men with prediabetes were recruited and randomized to either a High Protein (HP) (n = 12) or High Carbohydrate (HC) (n = 12) diet for 6 months with all food provided. OGTT and MTT were performed and GLP-1, GIP, Ghrelin, BNP, insulin and glucose were measured at baseline and 6 months on the respective diets. Our studies showed that subjects on the HP diet had 100% remission of prediabetes compared to only 33% on the HC diet with similar weight loss. HP diet subjects had a greater increase in (1) OGTT GLP-1 AUC(p = 0.001) and MTT GLP-1 AUC(p = 0.001), (2) OGTT GIP AUC(p = 0.005) and MTT GIP AUC(p = 0.005), and a greater decrease in OGTT ghrelin AUC(p = 0.005) and MTT ghrelin AUC(p = 0.001) and BNP(p = 0.001) compared to the HC diet at 6 months.. This study demonstrates that the HP diet increases GLP-1 and GIP which may be responsible in part for improved insulin sensitivity and β cell function compared to the HC diet. HP ghrelin results demonstrate the HP diet can reduce hunger more effectively than the HC diet. BNP and other CVRF, metabolic parameters and oxidative stress are significantly improved compared to the HC diet. CLINICALTRIALS.. NCT01642849. Topics: Adult; Appetite Regulation; Biomarkers; Diet, High-Protein; Dietary Carbohydrates; Female; Gastric Inhibitory Polypeptide; Ghrelin; Glucagon-Like Peptide 1; Heart Disease Risk Factors; Humans; Hunger; Incretins; Male; Middle Aged; Natriuretic Peptide, Brain; Obesity; Prediabetic State; Prospective Studies; Remission Induction; Tennessee; Time Factors; Treatment Outcome; Weight Loss; Young Adult | 2021 |
Once-Weekly Semaglutide in Adults with Overweight or Obesity.
Obesity is a global health challenge with few pharmacologic options. Whether adults with obesity can achieve weight loss with once-weekly semaglutide at a dose of 2.4 mg as an adjunct to lifestyle intervention has not been confirmed.. In this double-blind trial, we enrolled 1961 adults with a body-mass index (the weight in kilograms divided by the square of the height in meters) of 30 or greater (≥27 in persons with ≥1 weight-related coexisting condition), who did not have diabetes, and randomly assigned them, in a 2:1 ratio, to 68 weeks of treatment with once-weekly subcutaneous semaglutide (at a dose of 2.4 mg) or placebo, plus lifestyle intervention. The coprimary end points were the percentage change in body weight and weight reduction of at least 5%. The primary estimand (a precise description of the treatment effect reflecting the objective of the clinical trial) assessed effects regardless of treatment discontinuation or rescue interventions.. The mean change in body weight from baseline to week 68 was -14.9% in the semaglutide group as compared with -2.4% with placebo, for an estimated treatment difference of -12.4 percentage points (95% confidence interval [CI], -13.4 to -11.5; P<0.001). More participants in the semaglutide group than in the placebo group achieved weight reductions of 5% or more (1047 participants [86.4%] vs. 182 [31.5%]), 10% or more (838 [69.1%] vs. 69 [12.0%]), and 15% or more (612 [50.5%] vs. 28 [4.9%]) at week 68 (P<0.001 for all three comparisons of odds). The change in body weight from baseline to week 68 was -15.3 kg in the semaglutide group as compared with -2.6 kg in the placebo group (estimated treatment difference, -12.7 kg; 95% CI, -13.7 to -11.7). Participants who received semaglutide had a greater improvement with respect to cardiometabolic risk factors and a greater increase in participant-reported physical functioning from baseline than those who received placebo. Nausea and diarrhea were the most common adverse events with semaglutide; they were typically transient and mild-to-moderate in severity and subsided with time. More participants in the semaglutide group than in the placebo group discontinued treatment owing to gastrointestinal events (59 [4.5%] vs. 5 [0.8%]).. In participants with overweight or obesity, 2.4 mg of semaglutide once weekly plus lifestyle intervention was associated with sustained, clinically relevant reduction in body weight. (Funded by Novo Nordisk; STEP 1 ClinicalTrials.gov number, NCT03548935). Topics: Adult; Anti-Obesity Agents; Body Composition; Body Mass Index; Cholelithiasis; Diarrhea; Double-Blind Method; Female; Glucagon-Like Peptide 1; Glucagon-Like Peptides; Healthy Lifestyle; Humans; Injections, Subcutaneous; Lipids; Male; Middle Aged; Nausea; Obesity; Prediabetic State; Weight Loss | 2021 |
Effect of Subcutaneous Semaglutide vs Placebo as an Adjunct to Intensive Behavioral Therapy on Body Weight in Adults With Overweight or Obesity: The STEP 3 Randomized Clinical Trial.
Weight loss improves cardiometabolic risk factors in people with overweight or obesity. Intensive lifestyle intervention and pharmacotherapy are the most effective noninvasive weight loss approaches.. To compare the effects of once-weekly subcutaneous semaglutide, 2.4 mg vs placebo for weight management as an adjunct to intensive behavioral therapy with initial low-calorie diet in adults with overweight or obesity.. Randomized, double-blind, parallel-group, 68-week, phase 3a study (STEP 3) conducted at 41 sites in the US from August 2018 to April 2020 in adults without diabetes (N = 611) and with either overweight (body mass index ≥27) plus at least 1 comorbidity or obesity (body mass index ≥30).. Participants were randomized (2:1) to semaglutide, 2.4 mg (n = 407) or placebo (n = 204), both combined with a low-calorie diet for the first 8 weeks and intensive behavioral therapy (ie, 30 counseling visits) during 68 weeks.. The co-primary end points were percentage change in body weight and the loss of 5% or more of baseline weight by week 68. Confirmatory secondary end points included losses of at least 10% or 15% of baseline weight.. Of 611 randomized participants (495 women [81.0%], mean age 46 years [SD, 13], body weight 105.8 kg [SD, 22.9], and body mass index 38.0 [SD, 6.7]), 567 (92.8%) completed the trial, and 505 (82.7%) were receiving treatment at trial end. At week 68, the estimated mean body weight change from baseline was -16.0% for semaglutide vs -5.7% for placebo (difference, -10.3 percentage points [95% CI, -12.0 to -8.6]; P < .001). More participants treated with semaglutide vs placebo lost at least 5% of baseline body weight (86.6% vs 47.6%, respectively; P < .001). A higher proportion of participants in the semaglutide vs placebo group achieved weight losses of at least 10% or 15% (75.3% vs 27.0% and 55.8% vs 13.2%, respectively; P < .001). Gastrointestinal adverse events were more frequent with semaglutide (82.8%) vs placebo (63.2%). Treatment was discontinued owing to these events in 3.4% of semaglutide participants vs 0% of placebo participants.. Among adults with overweight or obesity, once-weekly subcutaneous semaglutide compared with placebo, used as an adjunct to intensive behavioral therapy and initial low-calorie diet, resulted in significantly greater weight loss during 68 weeks. Further research is needed to assess the durability of these findings.. ClinicalTrials.gov Identifier: NCT03611582. Topics: Adult; Anti-Obesity Agents; Cognitive Behavioral Therapy; Combined Modality Therapy; Diet, Reducing; Double-Blind Method; Female; Glucagon-Like Peptide 1; Glucagon-Like Peptides; Humans; Injections, Subcutaneous; Male; Middle Aged; Obesity; Overweight; Weight Loss | 2021 |
Effect of Continued Weekly Subcutaneous Semaglutide vs Placebo on Weight Loss Maintenance in Adults With Overweight or Obesity: The STEP 4 Randomized Clinical Trial.
The effect of continuing vs withdrawing treatment with semaglutide, a glucagon-like peptide 1 receptor agonist, on weight loss maintenance in people with overweight or obesity is unknown.. To compare continued once-weekly treatment with subcutaneous semaglutide, 2.4 mg, with switch to placebo for weight maintenance (both with lifestyle intervention) in adults with overweight or obesity after a 20-week run-in with subcutaneous semaglutide titrated to 2.4 mg weekly.. Randomized, double-blind, 68-week phase 3a withdrawal study conducted at 73 sites in 10 countries from June 2018 to March 2020 in adults with body mass index of at least 30 (or ≥27 with ≥1 weight-related comorbidity) and without diabetes.. A total of 902 participants received once-weekly subcutaneous semaglutide during run-in. After 20 weeks (16 weeks of dose escalation; 4 weeks of maintenance dose), 803 participants (89.0%) who reached the 2.4-mg/wk semaglutide maintenance dose were randomized (2:1) to 48 weeks of continued subcutaneous semaglutide (n = 535) or switched to placebo (n = 268), plus lifestyle intervention in both groups.. The primary end point was percent change in body weight from week 20 to week 68; confirmatory secondary end points were changes in waist circumference, systolic blood pressure, and physical functioning (assessed using the Short Form 36 Version 2 Health Survey, Acute Version [SF-36]).. Among 803 study participants who completed the 20-week run-in period (with a mean weight loss of 10.6%) and were randomized (mean age, 46 [SD, 12] years; 634 [79%] women; mean body weight, 107.2 kg [SD, 22.7 kg]), 787 participants (98.0%) completed the trial and 741 (92.3%) completed treatment. With continued semaglutide, mean body weight change from week 20 to week 68 was -7.9% vs +6.9% with the switch to placebo (difference, -14.8 [95% CI, -16.0 to -13.5] percentage points; P < .001). Waist circumference (-9.7 cm [95% CI, -10.9 to -8.5 cm]), systolic blood pressure (-3.9 mm Hg [95% CI, -5.8 to -2.0 mm Hg]), and SF-36 physical functioning score (2.5 [95% CI, 1.6-3.3]) also improved with continued subcutaneous semaglutide vs placebo (all P < .001). Gastrointestinal events were reported in 49.1% of participants who continued subcutaneous semaglutide vs 26.1% with placebo; similar proportions discontinued treatment because of adverse events with continued semaglutide (2.4%) and placebo (2.2%).. Among adults with overweight or obesity who completed a 20-week run-in period with subcutaneous semaglutide, 2.4 mg once weekly, maintaining treatment with semaglutide compared with switching to placebo resulted in continued weight loss over the following 48 weeks.. ClinicalTrials.gov Identifier: NCT03548987. Topics: Adult; Anti-Obesity Agents; Blood Pressure; Double-Blind Method; Female; Glucagon-Like Peptide 1; Glucagon-Like Peptides; Humans; Injections, Subcutaneous; Male; Middle Aged; Obesity; Overweight; Waist Circumference; Weight Loss | 2021 |
Severe sleep restriction suppresses appetite independent of effects on appetite regulating hormones in healthy young men without obesity.
Several nights of moderate (4-5 hr/night) sleep restriction increases appetite and energy intake, and may alter circulating concentrations of appetite regulating hormones. Whether more severe sleep restriction has similar effects is unclear. This study aimed to determine the effects of severe, short-term sleep restriction on appetite, ad libitum energy intake during a single meal, appetite regulating hormones, and food preferences.. Area under the curve (AUC) of postprandial hunger (-23%), desire to eat (-23%), and prospective consumption (-18%) ratings were all lower, and postprandial fullness AUC (25%) was higher after SR relative to after AS (p ≤ 0.02). Ad libitum energy intake at the lunch meal was 332 kcal [95% CI: -479, -185] (p<0.001) lower after SR relative to after AS, but relative macronutrient intakes and LFPQ scores did not differ. Postprandial glucose, insulin, PYY, GLP-1, and ghrelin AUCs did not differ between phases. However, mean concentrations of PYY (-11%) and GLP-1 (-4%) over the 4-hr testing period were lower, and glucose concentrations were 6% higher, after SR relative to after AS (p ≤ 0.01).. In contrast with reported effects of moderate sleep restriction, severe sleep restriction reduced appetite and energy intake, had no impact food preferences, and had little impact on appetite regulating hormones. Findings suggest that severe sleep restriction may suppress appetite and food intake, at least at a single meal, by a mechanism independent of changes in food preference or appetite regulating hormones. Topics: Appetite; Cross-Over Studies; Energy Intake; Ghrelin; Glucagon-Like Peptide 1; Humans; Insulin; Male; Obesity; Peptide YY; Postprandial Period; Prospective Studies; Sleep | 2021 |
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 |
GLP-1 Analog Modulates Appetite, Taste Preference, Gut Hormones, and Regional Body Fat Stores in Adults with Obesity.
Obesity is associated with alterations in appetite, gastrointestinal hormone levels and excessive fat mass. We previously published a double-blind, placebo-controlled, randomized, 16-week trial on effects of once-daily glucagon-like peptide-1 (GLP-1) analog, liraglutide on weight, satiation, and gastric functions in obese volunteers. The aim of this substudy is to compare to placebo the effects of liraglutide on appetite, taste preference, regional body fat stores, and anthropometric measurements.. Forty obese adults received standard instruction for weight management, monthly behavioral intervention utilizing motivational interviews, and 16-week treatment of once-daily liraglutide (escalated to 3 mg SQ daily). At baseline and 16 weeks, the following were measured: appetite and taste preferences rated every 30 min for 5 h after ingesting 300 mL Ensure®; maximal tolerated volume (MTV) with a nutrient drink test; fasting and postprandial bioactive GLP-1 (7-36) and peptide YY (PYY) levels; total and regional body fat with dual-energy X-ray absorptiometry, and waist and hip circumference.. Thirty-five participants (17 liraglutide; 18 placebo) completed the trial. Compared to placebo group, liraglutide group had significant reductions in MTV; prospective food consumption score; desire to eat something sweet, salty, savory or fatty; and an increase in perceived fullness. Postprandial plasma levels of GLP-1 decreased and PYY levels increased with liraglutide relative to baseline. Significant reductions in total body, trunk, and upper and lower body fat without reduction in lean body mass were observed.. Liraglutide 3 mg SQ modulates appetite, taste preference, gut hormones, and regional body fat stores in adults with obesity without reduction in lean body mass. Topics: Adipose Tissue; Adolescent; Adult; Aged; Appetite; Body Composition; Double-Blind Method; Female; Food Preferences; Gastrointestinal Hormones; Glucagon-Like Peptide 1; Humans; Hypoglycemic Agents; Liraglutide; Male; Middle Aged; Obesity; Placebos; Satiation; Taste; Young Adult | 2020 |
Intestinal sensing and handling of dietary lipids in gastric bypass-operated patients and matched controls.
Altered meal-related gut hormone secretion seems important for weight loss and diabetes remission after Roux-en-Y gastric bypass (RYGB). Elucidating the responsible meal components and receptors could aid discovery of new treatments of obesity and diabetes. Enteroendocrine cells respond to digestion products of dietary triacylglycerol, especially long-chain fatty acids (LCFAs) and 2-oleoyl-glycerol (2-OG), but not medium-chain fatty acids (MCFAs).. We examined the impact of olive oil (20 mL) and its derivates, LCFAs and 2-OG, on enteroendocrine secretions [glucagon-like peptide-1 (GLP-1), glucose-dependent insulinotropic polypeptide (GIP), cholecystokinin (CCK), peptide YY (PYY), and neurotensin (NT)] and on glucose, lipid, and bile acid metabolism in RYGB-operated and unoperated individuals.. In an exploratory randomized crossover design, 10 RYGB-operated patients and 10 matched controls ingested 3 equimolar triacylglycerol formulations on separate days: olive oil (digested to 2-OG + LCFAs), C8-dietary oil (2-OG + MCFAs), and tricaprylin (MCFAs; negative control). Hormone responses were calculated as area under the curve (AUC).. Independent of group status, olive oil had greater effects than C8-dietary oil on AUCs of plasma GLP-1 (+32%; 95% CI: 23%, 43%; P < 0.01), CCK (+53%, P < 0.01), and NT (+71%, P < 0.01), whereas the effect on GIP differed between groups (+90% in controls, P < 0.01; +24% in RYGB, P = 0.10). Independent of group status, C8-dietary oil had greater effects than tricaprylin on AUCs of plasma CCK (+40%, P < 0.01) and NT (+32%, P < 0.01), but not GLP-1 (+5%; 95% CI: -2.9%, 13%; P = 0.22), whereas the effect on GIP again differed between groups (+78% in controls, P < 0.01; +39% in RYGB, P = 0.01). Distal (GLP-1/PYY/NT), but not proximal (CCK/GIP), enteroendocrine responses were generally greater in RYGB patients than in controls.. The combination of LCFAs plus 2-OG was substantially more effective than 2-OG plus MCFAs in stimulating enteroendocrine secretion in RYGB-operated and matched control individuals. Distal lipid-induced gut hormone release was greater after RYGB.This trial was registered at clinicaltrials.gov as NCT03223389. Topics: Adult; Cholecystokinin; Dietary Fats; Female; Gastric Bypass; Gastric Inhibitory Polypeptide; Gastrointestinal Hormones; Glucagon-Like Peptide 1; Glycerides; Humans; Intestinal Mucosa; Male; Obesity; Peptide YY; Triglycerides | 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 |
Vasodilatory Actions of Glucagon-Like Peptide 1 Are Preserved in Skeletal and Cardiac Muscle Microvasculature but Not in Conduit Artery in Obese Humans With Vascular Insulin Resistance.
Obesity is associated with microvascular insulin resistance, which is characterized by impaired insulin-mediated microvascular recruitment. Glucagon-like peptide 1 (GLP-1) recruits skeletal and cardiac muscle microvasculature, and this action is preserved in insulin-resistant rodents. We aimed to examine whether GLP-1 recruits microvasculature and improves the action of insulin in obese humans.. Fifteen obese adults received intravenous infusion of either saline or GLP-1 (1.2 pmol/kg/min) for 150 min with or without a euglycemic insulin clamp (1 mU/kg/min) superimposed over the last 120 min. Skeletal and cardiac muscle microvascular blood volume (MBV), flow velocity and blood flow, brachial artery diameter and blood flow, and pulse wave velocity (PWV) were determined.. Insulin failed to change MBV or flow in either skeletal or cardiac muscle, confirming the presence of microvascular insulin resistance. GLP-1 infusion alone increased MBV by ∼30% and ∼40% in skeletal and cardiac muscle, respectively, with no change in flow velocity, leading to a significant increase in microvascular blood flow in both skeletal and cardiac muscle. Superimposition of insulin to GLP-1 infusion did not further increase MBV or flow in either skeletal or cardiac muscle but raised the steady-state glucose infusion rate by ∼20%. Insulin, GLP-1, and GLP-1 + insulin infusion did not alter brachial artery diameter and blood flow or PWV. The vasodilatory actions of GLP-1 are preserved in both skeletal and cardiac muscle microvasculature, which may contribute to improving metabolic insulin responses and cardiovascular outcomes.. In obese humans with microvascular insulin resistance, GLP-1's vasodilatory actions are preserved in both skeletal and cardiac muscle microvasculature, which may contribute to improving metabolic insulin responses and cardiovascular outcomes. Topics: Administration, Intravenous; Adult; Blood Glucose; Brachial Artery; Coronary Vessels; Female; Glucagon-Like Peptide 1; Glucose Clamp Technique; Heart; Humans; Insulin Resistance; Male; Microvessels; Muscle, Skeletal; Myocardium; Obesity; Pulse Wave Analysis; Vascular Resistance; Vasodilation; Vasodilator Agents | 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 |
Semaglutide Effects on Cardiovascular Outcomes in People With Overweight or Obesity (SELECT) rationale and design.
Cardiovascular disease (CVD) is a major cause of morbidity and mortality. Although it has been widely appreciated that obesity is a major risk factor for CVD, treatments that produce effective, durable weight loss and the impact of weight reduction in reducing cardiovascular risk have been elusive. Instead, progress in CVD risk reduction has been achieved through medications indicated for controlling lipids, hyperglycemia, blood pressure, heart failure, inflammation, and/or thrombosis. Obesity has been implicated as promoting all these issues, suggesting that sustained, effective weight loss may have independent cardiovascular benefit. GLP-1 receptor agonists (RAs) reduce weight, improve glycemia, decrease cardiovascular events in those with diabetes, and may have additional cardioprotective effects. The GLP-1 RA semaglutide is in phase 3 studies as a medication for obesity treatment at a dose of 2.4 mg subcutaneously (s.c.) once weekly. Semaglutide Effects on Heart Disease and Stroke in Patients with Overweight or Obesity (SELECT) is a randomized, double-blind, parallel-group trial testing if semaglutide 2.4 mg subcutaneously once weekly is superior to placebo when added to standard of care for preventing major adverse cardiovascular events in patients with established CVD and overweight or obesity but without diabetes. SELECT is the first cardiovascular outcomes trial to evaluate superiority in major adverse cardiovascular events reduction for an antiobesity medication in such a population. As such, SELECT has the potential for advancing new approaches to CVD risk reduction while targeting obesity. Topics: Cardiotonic Agents; Cardiovascular Diseases; Clinical Trials, Phase III as Topic; Double-Blind Method; Female; Glucagon-Like Peptide 1; Glucagon-Like Peptides; Heart Disease Risk Factors; Humans; Hypoglycemic Agents; Male; Middle Aged; Obesity; Outcome Assessment, Health Care; Overweight; Randomized Controlled Trials as Topic; Weight Loss | 2020 |
Effects of Nicotinamide Riboside on Endocrine Pancreatic Function and Incretin Hormones in Nondiabetic Men With Obesity.
Augmenting nicotinamide adenine dinucleotide (NAD+) metabolism through dietary provision of NAD+ precursor vitamins translates to improved glucose handling in rodent models of obesity and diabetes. Preclinical evidence suggests that the NAD+/SIRT1 axis may be implicated in modulating important gut-related aspects of glucose regulation. We sought to test whether NAD+ precursor supplementation with nicotinamide riboside (NR) affects β-cell function, α-cell function, and incretin hormone secretion as well as circulating bile acid levels in humans.. A 12-week randomized, double-blind, placebo-controlled, parallel-group trial in 40 males with obesity and insulin resistance allocated to NR at 1000 mg twice daily (n = 20) or placebo (n = 20). Two-hour 75-g oral glucose tolerance tests were performed before and after the intervention, and plasma concentrations of glucose, insulin, C-peptide, glucagon, glucagon-like peptide 1 (GLP-1), and glucose-dependent insulinotropic polypeptide (GIP) were determined. β-Cell function indices were calculated based on glucose, insulin, and C-peptide measurements. Fasting plasma concentrations of bile acids were determined.. NR supplementation during 12 weeks did not affect fasting or postglucose challenge concentrations of glucose, insulin, C-peptide, glucagon, GLP-1, or GIP, and β-cell function did not respond to the intervention. Additionally, no changes in circulating adipsin or bile acids were observed following NR supplementation.. The current study does not provide evidence to support that dietary supplementation with the NAD+ precursor NR serves to impact glucose tolerance, β-cell secretory capacity, α-cell function, and incretin hormone secretion in nondiabetic males with obesity. Moreover, bile acid levels in plasma did not change in response to NR supplementation. Topics: Blood Glucose; C-Peptide; Double-Blind Method; Gastric Inhibitory Polypeptide; Glucagon; Glucagon-Like Peptide 1; Glucose Tolerance Test; Humans; Insulin; Islets of Langerhans; Male; Middle Aged; Niacinamide; Obesity; Pyridinium Compounds | 2019 |
Effect of Meal Acceptability on Postprandial Appetite Scores and Hormones of Male Participants with Varied Adiposity.
This study portrays the effect of hedonic manipulation (high acceptability [HA] vs. low acceptability [LA]) on postprandial hormones and appetite scores in healthy males.. Thirty participants (15 with normal weight and 15 with obesity) were recruited for a randomized, crossover design. They were randomly assigned to the HA or LA (with acesulfame-K) custard. Blood samples were drawn before the meals and for 4 hours after the meals and were analyzed for glucose, insulin, ghrelin, and glucagonlike peptide 1 (GLP-1). Appetite scores and subsequent energy intake were recorded.. Postprandial glucose, insulin, and ghrelin were different according to adiposity, whereas meal acceptability did not correspond to any significant difference in postprandial glucose, insulin, ghrelin, and GLP-1 concentrations. Appetite scores showed lower hunger, higher satiety, and fullness after the HA meal without a significant difference between the meals. Subsequent energy intake, expressed as a percentage of the resting energy expenditure, was higher in participants with obesity but did not reflect postprandial hormones and appetite scores; there was no significant difference between meals.. Hedonic properties and palatability do not affect gut hormones, mainly ghrelin and GLP-1. Moreover, their postprandial concentrations were not paralleled by similar changes in appetite scores, and both were not found to affect subsequent intake. Topics: Adiposity; Adolescent; Adult; Appetite; Cross-Over Studies; Double-Blind Method; Energy Intake; Gastrointestinal Hormones; Ghrelin; Glucagon-Like Peptide 1; Humans; Hunger; Insulin; Male; Meals; Middle Aged; Obesity; Personal Satisfaction; Postprandial Period; Research Design; Satiation; Young Adult | 2019 |
A ketone monoester drink reduces the glycemic response to an oral glucose challenge in individuals with obesity: a randomized trial.
Exogenous ketones make it possible to reach a state of ketosis that may improve metabolic control in humans.. The main objective of this study was to determine whether the ingestion of a ketone monoester (KE) drink before a 2-h oral-glucose-tolerance test (OGTT) would lower blood glucose concentrations. Secondary objectives were to determine the impact of KE on nonesterified fatty acid (NEFA) concentration and glucoregulatory hormones.. We conducted a randomized controlled crossover experiment in 15 individuals with obesity (mean ± SD age: 47 ± 10 y; BMI: 34 ± 5 kg/m2). After an overnight fast, participants consumed a KE drink [(R)-3-hydroxybutyl (R)-3-hydroxybutyrate; 0.45 mL/kg body weight] or taste-matched control drink 30 min before completing a 75-g OGTT. Participants and study personnel performing laboratory analyses were blinded to each condition.. The KE increased d-β-hydroxybutyrate to a maximum of ∼3.4 mM (P < 0.001) during the OGTT. Compared with the control drink, KE reduced glucose (-11%, P = 0.002), NEFA (-21%, P = 0.009), and glucagon-like peptide 1 (-31%, P = 0.001) areas under the curve (AUCs), whereas glucagon AUC increased (+11%, P = 0.030). No differences in triglyceride, C-peptide, and insulin AUCs were observed after the KE drink. Mean arterial blood pressure decreased and heart rate increased after the KE drink (both P < 0.01).. A KE drink consumed before an OGTT lowered glucose and NEFA AUCs with no increase in circulating insulin. Our results suggest that a single drink of KE may acutely improve metabolic control in individuals with obesity. Future research is warranted to examine whether KE could be used safely to have longer-term effects on metabolic control. This trial was registered at clinicaltrials.gov as NCT03461068. Topics: 3-Hydroxybutyric Acid; Adult; Blood Glucose; Dietary Supplements; Female; Glucagon; Glucagon-Like Peptide 1; Glucose Tolerance Test; Glycemic Index; Humans; Ketones; Male; Middle Aged; Obesity | 2019 |
Sleep and meal timing influence food intake and its hormonal regulation in healthy adults with overweight/obesity.
Studies associate sleeping and eating late in the day with poor dietary quality and higher obesity risk but differences in sleep duration confound this association. We aimed to determine whether sleep and meal timing, independent of sleep duration, influenced food intake in healthy adults.. This was a controlled, 2 × 2 inpatient crossover study with normal (0000-0800 h) or late (0330-1130 h) sleep and normal (1, 5, 11, and 12.5 h after awakening) or late (4.5, 8.5, 14.5, and 16 h after awakening) meals. Food intake was controlled while blood samples were obtained for determination of appetite-regulating hormones on days 3-4. Self-selected food intake was assessed on day 5. Data were analyzed using linear mixed model analysis with sleep, meal, and sleep x meal interaction as dependent variables.. Five participants completed all phases (mean age 25.1 ± [SD] 3.9 y, body mass index 29.2 ± 2.7 kg/m. Our results suggest that alignment of sleep and meals may influence food choice and energy balance. Additional research is necessary to expand and confirm our findings. Topics: Adult; Cross-Over Studies; Energy Intake; Female; Ghrelin; Glucagon-Like Peptide 1; Humans; Leptin; Male; Meals; Obesity; Overweight; Sleep | 2019 |
Effects of active commuting and leisure-time exercise on appetite in individuals with overweight and obesity.
Acute exercise is associated with a transient suppression of appetite. The effects of regular exercise on appetite are not well understood. We aimed to determine the effects of active commuting and leisure-time exercise on appetite. One hundred thirty physically inactive women and men (20-45 yr) with overweight and obesity were randomized to 6 mo of habitual lifestyle (CON, n = 18), active commuting (BIKE, n = 35), or leisure-time exercise of moderate [MOD, 50% peak oxygen uptake (V̇o Topics: Adult; Appetite; Appetite Regulation; Energy Intake; Energy Metabolism; Exercise; Female; Ghrelin; Glucagon-Like Peptide 1; Humans; Hunger; Leisure Activities; Male; Meals; Middle Aged; Obesity; Overweight; Oxygen Consumption; Peptide YY; Postprandial Period; Sedentary Behavior; Transportation; Young Adult | 2019 |
Whey Proteins Reduce Appetite, Stimulate Anorexigenic Gastrointestinal Peptides and Improve Glucometabolic Homeostasis in Young Obese Women.
Proteins, particularly whey proteins, represent the most satiating macronutrient in animals and humans. A dietetic regimen based on proteins enriched preload before eating might be a strategy to counteract obesity.. Each drink significantly augmented satiety and reduced hunger, and the effects were more evident with whey proteins than maltodextrins. Similarly, there were significant increases in GLP-1 and PYY levels (but not PP) after the ingestion of each drink; these anorexigenic responses were higher with whey proteins than maltodextrins. While insulinemia identically increased after each drink, whey proteins induced a lower glycemic response than maltodextrins. No differences in satiety and hunger were found after the meal, which is presumably due to the late administration of the meal test, when the hypophagic effect of whey proteins was disappearing.. While whey proteins actually reduce appetite, stimulate anorexigenic gastrointestinal peptides, and improve glucometabolic homeostasis in young obese women, further additional studies are mandatory to demonstrate their hypophagic effects in obese subjects, when administered as preload before eating. Topics: Adolescent; Adult; Appetite; Blood Glucose; Female; Glucagon-Like Peptide 1; Homeostasis; Humans; Insulin; Obesity; Pancreatic Polypeptide; Peptide YY; Polysaccharides; Satiation; Whey Proteins; Young Adult | 2019 |
Effects of combined GIP and GLP-1 infusion on energy intake, appetite and energy expenditure in overweight/obese individuals: a randomised, crossover study.
Glucagon-like peptide 1 (GLP-1) reduces appetite and energy intake in humans, whereas the other incretin hormone, glucose-dependent insulinotropic polypeptide (GIP), seems to have no effect on eating behaviour. Interestingly, studies in rodents have shown that concomitant activation of GIP and GLP-1 receptors may potentiate the satiety-promoting effect of GLP-1, and a novel dual GLP-1/GIP receptor agonist was recently shown to trigger greater weight losses compared with a GLP-1 receptor agonist in individuals with type 2 diabetes. The aim of this study was to delineate the effects of combined GIP and GLP-1 receptor activation on energy intake, appetite and resting energy expenditure in humans.. We examined 17 overweight/obese men in a crossover design with 5 study days. On day 1, a 50 g OGTT was performed; on the following 4 study days, the men received an isoglycaemic i.v. glucose infusion (IIGI) plus saline (154 mmol/l NaCl; placebo), GIP (4 pmol kg. Energy intake was significantly reduced during IIGI+GLP-1 compared with IIGI+saline infusion (2715 ± 409 vs 4483 ± 568 kJ [mean ± SEM, n = 17], p = 0.014), whereas there were no significant differences in energy intake during IIGI+GIP (4062 ± 520 kJ) or IIGI+GIP+GLP-1 (3875 ± 451 kJ) infusion compared with IIGI+saline (p = 0.590 and p = 0.364, respectively). Energy intake was higher during IIGI+GIP+GLP-1 compared with IIGI+GLP-1 infusion (p = 0.039).. While GLP-1 infusion lowered energy intake in overweight/obese men, simultaneous GIP infusion did not potentiate this GLP-1-mediated effect.. ClinicalTrials.gov NCT02598791 FUNDING: This study was supported by grants from the Innovation Fund Denmark and the Vissing Foundation. Topics: Adult; Aged; Appetite; Blood Glucose; Calorimetry; Cross-Over Studies; Double-Blind Method; Energy Intake; Energy Metabolism; Gastric Inhibitory Polypeptide; Glucagon; Glucagon-Like Peptide 1; Humans; Insulin; Male; Middle Aged; Obesity; Overweight; Weight Loss | 2019 |
Important Role of the GLP-1 Axis for Glucose Homeostasis after Bariatric Surgery.
Bariatric surgery is widely used to treat obesity and improves type 2 diabetes beyond expectations from the degree of weight loss. Elevated post-prandial concentrations of glucagon-like peptide 1 (GLP-1), peptide YY (PYY), and insulin are widely reported, but the importance of GLP-1 in post-bariatric physiology remains debated. Here, we show that GLP-1 is a major driver of insulin secretion after bariatric surgery, as demonstrated by blocking GLP-1 receptors (GLP1Rs) post-gastrectomy in lean humans using Exendin-9 or in mice using an anti-GLP1R antibody. Transcriptomics and peptidomics analyses revealed that human and mouse enteroendocrine cells were unaltered post-surgery; instead, we found that elevated plasma GLP-1 and PYY correlated with increased nutrient delivery to the distal gut in mice. We conclude that increased GLP-1 secretion after bariatric surgery arises from rapid nutrient delivery to the distal gut and is a key driver of enhanced insulin secretion. Topics: Adult; Animals; Bariatric Surgery; Enteroendocrine Cells; Female; Glucagon-Like Peptide 1; Glucose; Homeostasis; Humans; Hypoglycemic Agents; Insulin Secretion; Intestinal Mucosa; Male; Mice; Mice, Inbred C57BL; Middle Aged; Obesity; Peptide Fragments; Peptide YY; Postoperative Period; Transcriptome | 2019 |
Effect of dairy and nondairy snacks on postprandial blood glucose regulation in 9-14-year-old children.
Topics: Adolescent; Appetite; Blood Glucose; C-Peptide; Child; Cross-Over Studies; Dairy Products; Female; Glucagon-Like Peptide 1; Humans; Insulin; Liver; Male; Obesity; Overweight; Postprandial Period; Snacks | 2019 |
Meal-Related Acyl and Des-Acyl Ghrelin and Other Appetite-Related Hormones in People with Obesity and Binge Eating.
Potential mechanisms of abnormal food intake, such as dysregulation of meal-related appetite hormones, including acyl ghrelin (AG) and des-acyl ghrelin (DAG), were investigated among men and women with obesity, with and without binge eating (BE).. Participants (n = 42: 19 female, 23 male) were assigned to a liquid meal and water condition in counterbalanced order, and blood samples for measuring hormones were obtained before and after these conditions.. Participants with BE had significantly lower fasting and postingestive AG concentrations than participants without BE in both conditions. During the meal condition, postprandial decreases in AG concentrations were significantly smaller for the BE group than for the non-BE group. There were no significant differences in DAG by BE group. Leptin increased significantly less after meals for those with BE compared with those without BE. There were no differences in other hormones by BE group. Fasting and postmeal hunger ratings were significantly higher for those with BE than for those without BE.. In individuals with BE, lower fasting AG may be due to downregulation by habitual overeating, and a smaller postmeal decline in AG may contribute to overeating. Lower postmeal leptin concentrations may also contribute to overeating. Topics: Adult; Appetite; Binge-Eating Disorder; Bulimia; Cholecystokinin; Eating; Female; Ghrelin; Glucagon-Like Peptide 1; Humans; Hyperphagia; Insulin; Leptin; Male; Meals; Middle Aged; Obesity; Peptide YY; Postprandial Period; Young Adult | 2019 |
Postprandial levels of GLP-1, GIP and glucagon after 2 years of weight loss with a Paleolithic diet: a randomised controlled trial in healthy obese women.
Objective To investigate how weight loss by different diets impacts postprandial levels of glucagon-like peptide 1 (GLP-1), glucose-dependent insulinotropic polypeptide (GIP) and glucagon. Methods In this single-centre, parallel group 2-year trial, 70 healthy postmenopausal obese women were randomised to the Paleolithic diet or a healthy control diet based on Nordic Nutrition Recommendations. Both diets were without calorie restriction. The primary outcome was the change in fat mass. Here, secondary analyses on GLP-1, GIP and glucagon measured during an OGTT are described. Results In the Paleolithic diet group, mean weight loss compared to baseline was 11% at 6 months and 10% at 24 months. In the control diet group, mean weight loss was 6% after 6 and 24 months (P = 0.0001 and P = 0.049 for the comparison between groups at 6 and 24 months respectively). Compared to baseline, the mean incremental area under the curve (iAUC) for GLP-1 increased by 34 and 45% after 6 and 24 months in the Paleolithic diet group and increased by 59% after 24 months in the control diet group. The mean iAUC for GIP increased only in the Paleolithic diet group. The area under the curve (AUC) for glucagon increased during the first 6 months in both groups. The fasting glucagon increase correlated with the β-hydroxybutyrate increase. Conclusions Weight loss caused an increase in postprandial GLP-1 levels and a further rise occurred during weight maintenance. Postprandial GIP levels increased only after the Paleolithic diet. Reduced postprandial glucagon suppression may be caused by a catabolic state. Topics: Aged; Biomarkers; Diet, Paleolithic; Energy Intake; Female; Gastric Inhibitory Polypeptide; Glucagon; Glucagon-Like Peptide 1; Humans; Middle Aged; Obesity; Postprandial Period; Weight Loss | 2019 |
Investigating the effect of sex and ketosis on weight-loss-induced changes in appetite.
Diet-induced weight loss (WL) is usually accompanied by increased appetite, a response that seems to be absent when ketogenic diets are used. It remains unknown if sex modulates the appetite suppressant effect of ketosis.. The aim of this study was to examine if sex modulates the impact of WL-induced changes in appetite and if ketosis alters these responses.. Ninety-five individuals (55 females) with obesity (BMI [kg/m 2]: 37 ± 4) underwent 8 wk of a very-low-energy diet, followed by 4 wk of refeeding and weight stabilization. Body composition, plasma concentration of β-hydroxybutyrate (β-HB) and appetite-related hormones (active ghrelin, active glucagon-like peptide 1 [GLP-1], total peptide YY [PYY], cholecystokinin and insulin), and subjective feelings of appetite were measured at baseline, week 9 in ketosis, and week 13 out of ketosis.. The mean WL at week 9 was 17% for males and 15% for females, which was maintained at week 13. Weight, fat, and fat-free mass loss were greater in males (P < 0.001 for all) and the increase in β-HB at week 9 higher in females (1.174 ± 0.096 compared with 0.783 ± 0.112 mmol/L, P = 0.029). Basal and postprandial GLP-1 and postprandial PYY (all P < 0.05) were significantly different for males and females. There were no significant sex × time interactions for any other appetite-related hormones or subjective feelings of appetite. At week 9, basal GLP-1 was decreased only in males (P < 0.001), whereas postprandial GLP-1 was increased only in females (P < 0.001). No significant changes in postprandial PYY were observed over time for either sex.. Ketosis appears to have a greater beneficial impact on GLP-1 in females. However, sex does not seem to modulate the changes in the secretion of other appetite-related hormones, or subjective feelings of appetite, seen with WL, regardless of the ketotic state. This trial was registered at clinicaltrials.gov as NCT01834859. Topics: Adolescent; Adult; Aged; Appetite; Cholecystokinin; Female; Ghrelin; Glucagon-Like Peptide 1; Humans; Insulin; Ketosis; Male; Middle Aged; Obesity; Peptide YY; Sex Factors; Weight Loss; Young Adult | 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 |
Impact of phenylketonuria type meal on appetite, thermic effect of feeding and postprandial fat oxidation.
Dietary management of phenylketonuria (PKU) requires the replacement of natural protein-containing foods with special low protein foods. The effect of a PKU type diet on factors contributing to energy balance requires investigation.. To investigate the impact of a PKU type meal on appetite ratings, gut appetite hormones, thermic effect of feeding (TEF) and fat oxidation.. Twenty-three healthy adults (mean ± SD age: 24.3 ± 5.1 years; BMI: 22.4 ± 2.5 kg/m. Responses of appetite ratings, plasma concentrations of GLP-1 and PYY (P > 0.05, trial effect, two-way ANOVA) and energy intake during ad libitum buffet dinner (P > 0.05, paired t-test) were not significantly different between the two trials. The TEF (PKU, 10.2 ± 1.5%; Control, 13.2 ± 1.0%) and the total amount of fat oxidized (PKU, 18.90 ± 1.10 g; Control, 22.10 ± 1.10 g) were significantly (P < 0.05, paired t-tests) lower in the PKU than in the Control trial. The differences in TEF and fat oxidation were significant (P < 0.05, paired t-tests) for the post-meal period.. Consumption of a meal composed of special low protein foods has no detrimental impact on appetite and appetite hormones but produces a lower TEF and postprandial fat oxidation than an ordinary meal. These metabolic alterations may contribute to the increased prevalence of obesity reported in patients with PKU on contemporary dietary management.. The trial has been registered in ClinicalTrials as NCT02440932. Topics: Adult; Appetite; Blood Glucose; Body Mass Index; Cross-Over Studies; Diet, Protein-Restricted; Dietary Fats; Eating; Energy Intake; Energy Metabolism; Female; Glucagon-Like Peptide 1; Humans; Insulin; Male; Obesity; Oxidation-Reduction; Peptide YY; Phenylketonurias; Postprandial Period; Thermogenesis; Young Adult | 2018 |
Compensatory mechanisms activated with intermittent energy restriction: A randomized control trial.
Strong compensatory responses, with reduced resting metabolic rate (RMR), increased exercise efficiency (ExEff) and appetite, are activated when weight loss (WL) is achieved with continuous energy restriction (CER), which try to restore energy balance. Intermittent energy restriction (IER), where short spells of energy restriction are interspaced by periods of habitual energy intake, may offer some protection in minimizing those responses. We aimed to compare the effect of IER versus CER on body composition and the compensatory responses induced by WL.. Changes in body weight (≈12.5% WL) and composition were similar in both groups. Fasting RQ and ExEff at 10 W increased in both groups. Losing weight, either by IER or CER dieting, did not induce significant changes in subjective appetite ratings. RMR decreased and ExEff at 25 and 50 W increased (P < 0.001 for all) in IER group only. Basal and postprandial AG increased (P < 0.05) in IER group, whereas basal active GLP-1 decreased (P = 0.033) in CER group only. Postprandial CCK decreased in both groups (P = 0.0012 and P = 0.009 for IER and CER groups, respectively). No between group differences were apparent for any of the outcomes.. The technique used to achieve energy restriction, whether it is continuous or intermittent, does not appear to modulate the compensatory mechanisms activated by weight loss.. NCT02169778 (the study was registered in clinicaltrial.gov). Topics: Adult; Basal Metabolism; Body Composition; Body Weight; Caloric Restriction; Cholecystokinin; Diet, Reducing; Eating; Energy Intake; Exercise; Ghrelin; Glucagon-Like Peptide 1; Humans; Hunger; Middle Aged; Norway; Obesity; Oxygen Consumption; Peptide YY; Weight Loss | 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 |
Low subjective socioeconomic status stimulates orexigenic hormone ghrelin - A randomised trial.
Recent evidence suggests that lower perceived socioeconomic status is linked to increased appetite and intake of greater calories. Yet, whether insecurity of socioeconomic resources directly influences regulatory systems of appetite and energy intake is not known. Considering psychological states, mindsets and beliefs have shown to meaningfully affect physiological responses to food, the present study tested the hypothesis that low subjective socioeconomic status (SSS) will have a direct influence on physiological responses, such as appetite-related hormones (ghrelin, pancreatic polypeptide and insulin). Forty-eight healthy males were randomly (crossover, counterbalanced) assigned, to two experimental conditions where participants were either experimentally induced to feel low SSS or not (control; CON). Feelings of low SSS resulted in an increase in active ghrelin (an orexigenic hormone) following the SSS manipulation compared with baseline, while no change in active ghrelin was observed in CON. Furthermore, participants reported lower fullness and satiety following low SSS compared with CON. Our findings demonstrate that SSS may influence hunger regulation and appetite, and suggest that physiological systems regulating energy balance (i.e. caloric resources) may also be sensitive to perceived deprivation or imbalances in critical non-food resources (socioeconomic resources). Topics: Appetite; Blood Glucose; Cross-Over Studies; Energy Intake; Energy Metabolism; Ghrelin; Glucagon-Like Peptide 1; Humans; Hunger; Insulin; Male; Obesity; Pancreatic Polypeptide; Protein Precursors; Social Class | 2018 |
A high carbohydrate, but not fat or protein meal attenuates postprandial ghrelin, PYY and GLP-1 responses in Chinese men.
It is known that the macronutrient content of a meal has different impacts on the postprandial satiety and appetite hormonal responses. Whether obesity interacts with such nutrient-dependent responses is not well characterized. We examined the postprandial appetite and satiety hormonal responses after a high-protein (HP), high-carbohydrate (HC), or high-fat (HF) mixed meal. This was a randomized cross-over study of 9 lean insulin-sensitive (mean±SEM HOMA-IR 0.83±0.10) and 9 obese insulin-resistant (HOMA-IR 4.34±0.41) young (age 21-40 years), normoglycaemic Chinese men. We measured fasting and postprandial plasma concentration of glucose, insulin, active glucagon-like peptide-1 (GLP-1), total peptide-YY (PYY), and acyl-ghrelin in response to HP, HF, or HC meals. Overall postprandial plasma insulin response was more robust in the lean compared to obese subjects. The postprandial GLP-1 response after HF or HP meal was higher than HC meal in both lean and obese subjects. In obese subjects, HF meal induced higher response in postprandial PYY compared to HC meal. HP and HF meals also suppressed ghrelin greater compared to HC meal in the obese than lean subjects. In conclusion, a high-protein or high-fat meal induces a more favorable postprandial satiety and appetite hormonal response than a high-carbohydrate meal in obese insulin-resistant subjects. Topics: Adult; Asian People; Blood Glucose; Cross-Over Studies; Diet, High-Fat; Diet, High-Protein; Dietary Carbohydrates; Dietary Fats; Dietary Proteins; Ghrelin; Glucagon-Like Peptide 1; Humans; Insulin; Insulin Resistance; Male; Obesity; Peptide YY; Postprandial Period; Satiety Response; Singapore; Young Adult | 2018 |
Acute administration of capsaicin increases resting energy expenditure in young obese subjects without affecting energy intake, appetite, and circulating levels of orexigenic/anorexigenic peptides.
Topics: Adolescent; Adult; Appetite; Basal Metabolism; Calorimetry, Indirect; Capsaicin; Capsicum; Energy Intake; Female; Ghrelin; Glucagon-Like Peptide 1; Humans; Hunger; Male; Meals; Obesity; Peptide YY; Plant Extracts; Postprandial Period; Satiety Response; Single-Blind Method; Young Adult | 2018 |
Energy compensation in response to aerobic exercise training in overweight adults.
Weight loss from exercise is often less than expected. Putative compensatory mechanisms may limit exercise-induced reductions in body fat and might be proportional to exercise energy expenditure (ExEE). This study was conducted to determine compensation for (the difference between accumulated exercise energy expenditure and changes in body tissue energy stores) and compensatory responses to 1,500 or 3,000 kcal/wk of ExEE. Overweight-to-obese ( n = 36) sedentary men and women were randomized to groups expending 300 or 600 kcal/exercise session, 5 days/wk, for 12 wk. Fourteen participants in the 300-kcal group and 15 in the 600-kcal group completed the study. The primary outcome was energy compensation assessed through changes in body tissue energy stores. Secondary outcomes were putative compensatory responses of resting metabolic rate, food reinforcement, dietary intake, and serum acylated ghrelin and glucagon-like peptide-1. All measures were determined pre- and posttraining. The 3,000 kcal/wk group decreased ( P < 0.01) percentage and kilograms of body fat, while the 1,500 kcal/wk group did not. The 1,500 and 3,000 kcal/wk groups compensated for 943 (-164 to 2,050) and 1,007 (32 to 1,982) kcal/wk (mean, 95% CI, P ≥ 0.93), or 62.9% and 33.6% of ExEE, respectively. Resting metabolic rate and energy intake did not change. Food reinforcement and glucagon-like peptide-1 decreased ( P < 0.02), whereas acylated ghrelin increased ( P ≤ 0.02). Compensation is not proportional to ExEE. Similar energy compensation occurred in response to1,500 and 3,000 kcal/wk of ExEE. ExEE of 3,000 kcal/wk is sufficient to exceed compensatory responses and reduce fat mass. Topics: Acylation; Adaptation, Physiological; Adiposity; Adult; Biomarkers; Body Mass Index; Energy Metabolism; Exercise Therapy; Feeding Behavior; Female; Ghrelin; Glucagon-Like Peptide 1; Humans; Male; North Dakota; Obesity; Reinforcement, Psychology; Sedentary Behavior; Time Factors; Treatment Outcome; Weight Loss; Young Adult | 2018 |
Acute Effects of High-Intensity Interval and Moderate-Intensity Continuous Exercise on GLP-1, Appetite and Energy Intake in Obese Men: A Crossover Trial.
This study investigated the effect of high-intensity interval (HIIE) and moderate-intensity continuous exercise (MICE) on glucagon-like peptide 1 (GLP-1), appetite and energy intake (EI) in obese men. In a randomized crossover trial, 12 participants (28.4 ± 2.6 years, 35.5 ± 4.5 kg/m², 39.8 ± 2.2% body fat) performed: (I) Control (CON, no exercise); (II) MICE (20 min, 70% of maximal heart rate) and (III) HIIE (10 × 1 min at 90% of maximal heart rate with 1 min recovery). GLP-1 and appetite were assessed at: (I) PRE: pre-exercise; (II) POST: immediately post-exercise; (III) POST-1 h: 1 h post-exercise. EI was assessed after an Topics: Adult; Appetite Regulation; Biomarkers; Brazil; Cross-Over Studies; Eating; Energy Intake; Exercise Therapy; Glucagon-Like Peptide 1; High-Intensity Interval Training; Humans; Hunger; Male; Obesity; Time Factors; Treatment Outcome; Young Adult | 2018 |
Efficacy and safety of semaglutide compared with liraglutide and placebo for weight loss in patients with obesity: a randomised, double-blind, placebo and active controlled, dose-ranging, phase 2 trial.
Obesity is a major public health issue, and new pharmaceuticals for weight management are needed. Therefore, we evaluated the efficacy and safety of the glucagon-like peptide-1 (GLP-1) analogue semaglutide in comparison with liraglutide and a placebo in promoting weight loss.. We did a randomised, double-blind, placebo and active controlled, multicentre, dose-ranging, phase 2 trial. The study was done in eight countries involving 71 clinical sites. Eligible participants were adults (≥18 years) without diabetes and with a body-mass index (BMI) of 30 kg/m. Between Oct 1, 2015, and Feb 11, 2016, 957 individuals were randomly assigned (102-103 participants per active treatment group and 136 in the pooled placebo group). Mean baseline characteristics included age 47 years, bodyweight 111·5 kg, and BMI 39·3 kg/m. In combination with dietary and physical activity counselling, semaglutide was well tolerated over 52 weeks and showed clinically relevant weight loss compared with placebo at all doses.. Novo Nordisk A/S. Topics: Adult; Blood Glucose; Body Mass Index; Double-Blind Method; Female; Glucagon-Like Peptide 1; Glucagon-Like Peptides; Glycated Hemoglobin; Humans; Hypoglycemic Agents; Injections, Subcutaneous; Liraglutide; Male; Middle Aged; Obesity; Placebos; Treatment Outcome; Weight Loss | 2018 |
Impact of short-term exercise training intensity on β-cell function in older obese adults with prediabetes.
Topics: Female; Gastric Inhibitory Polypeptide; Glucagon-Like Peptide 1; Glucose Tolerance Test; High-Intensity Interval Training; Humans; Insulin Secretion; Insulin-Secreting Cells; Male; Middle Aged; Obesity; Prediabetic State | 2018 |
High-Intensity Interval Training, Appetite, and Reward Value of Food in the Obese.
Studies on the effect of chronic interval training on appetite in the obese population are scarce. The aim of this study was to determine the effect of 12 wk of isocaloric programs of moderate-intensity continuous training (MICT), high-intensity interval training (HIIT), or short-duration HIIT on subjective feelings of appetite, appetite-related hormones, and reward value of food in sedentary obese individuals.. Forty-six sedentary obese individuals (30 women and 16 men), with a body mass index of 33.3 ± 2.9 kg·m and age of 34.4 ± 8.8 yr, were randomly assigned to one of the three training groups: MICT (n = 14), HIIT (n = 16), or short-duration HIIT (n = 16). Exercise was performed three times per week for 12 wk. Subjective feelings of appetite and plasma levels of acylated ghrelin, polypeptide YY3-36, and glucagon-like peptide 1 were measured before and after a standard breakfast (every 30 min up to 3 h), before and after the exercise intervention. Fat and sweet taste preferences and food reward were measured using the Leeds Food Preference Questionnaire.. A significant increase in fasting and postprandial feelings of hunger was observed with the exercise intervention (P = 0.01 and P = 0.048, respectively), but no effect of group and no interaction. No significant effect of exercise intervention, group, or interaction was found on fasting or postprandial subjective feelings of fullness, desire to eat, and prospective food consumption or plasma concentration of acylated ghrelin, polypeptide YY3-36, and glucagon-like peptide 1. No changes in food preference or reward over time, differences between groups, or interactions were found.. This study suggests that chronic HIIT has no independent effect on appetite or food reward when compared with an isocaloric program of MICT in obese individuals. Topics: Adult; Appetite; Energy Intake; Fasting; Female; Food Preferences; Ghrelin; Glucagon-Like Peptide 1; High-Intensity Interval Training; Humans; Male; Obesity; Peptide Fragments; Peptide YY; Postprandial Period; Prospective Studies; Reward | 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 |
A walnut-containing meal had similar effects on early satiety, CCK, and PYY, but attenuated the postprandial GLP-1 and insulin response compared to a nut-free control meal.
Regular nut consumption is associated with lower adiposity and reduced weight gain in adulthood. Walnut feeding studies have observed minimal effect on body weight despite potential additional energy intake. Several mechanisms may explain why consuming nuts promotes weight control, including increased early phase satiety, possibly reflected in postprandial response of gastrointestinal and pancreatic peptides hypothesized to affect appetite. The purpose of this study was to compare postprandial insulin, glucagon and gastrointestinal peptide response and satiety following a meal with ∼54% of energy from walnuts or cream cheese, using a within-subject crossover study design in overweight/obese adults (N = 28). Sixty minutes after the walnut-containing meal, glucagon-like peptide-1 was lower than after the reference meal (p=0.0433), and peptide YY, cholecystokinin and ghrelin did not differ after the two meals. Sixty and 120 min after the walnut-containing meal, pancreatic polypeptide (p = 0.0014 and p = 0.0002) and glucose-dependent insulinotropic peptide (p < 0.0001 and p = 0.0079) were lower than after the reference meal, and 120 min after the walnut-containing meal, glucagon was higher (p=0.0069). Insulin and C-peptide increased at 60 min in response to both meals but were lower at 120 min after the walnut-containing meal (p=0.0349 and 0.0237, respectively). Satiety measures were similar after both meals. These findings fail to support the hypothesis that acute postprandial gastrointestinal peptide response to a walnut-containing meal contributes to increased satiety. However, inclusion of walnuts attenuated the postprandial insulin response, which may contribute to the more favorable lipid profile observed in association with regular walnut consumption. Topics: Adult; Aged; Cholecystokinin; Cross-Over Studies; Diet; Energy Intake; Feeding Behavior; Female; Gastrointestinal Hormones; Glucagon; Glucagon-Like Peptide 1; Humans; Insulin; Juglans; Male; Meals; Middle Aged; Nuts; Obesity; Peptide YY; Peptides; Postprandial Period; Satiation | 2017 |
Incretin secretion in humans is under the influence of cannabinoid receptors.
The mechanisms regulating incretin secretion are not fully known. Human obesity is associated with altered incretin secretion and elevated endocannabinoid levels. Since cannabinoid receptors (CBRs) are expressed on incretin-secreting cells in rodents, we hypothesized that endocannabinoids are involved in the regulation of incretin secretion. We compared plasma glucose-dependent insulinotropic polypeptide (GIP) and glucagon-like peptide-1 (GLP-1) responses during oral glucose tolerance test (OGTT) in 20 lean and 20 obese participants from the Baltimore Longitudinal Study of Aging (BLSA). Next, we recruited 20 healthy men to evaluate GIP and GLP-1 responses during OGTT after administering placebo or nabilone (CBR agonist) in a randomized, double-blind, crossover fashion. Compared with the BLSA lean group, the BLSA obese group had significantly higher fasting and post-OGTT GIP levels, but similar fasting GLP-1 and significantly lower post-OGTT GLP-1 levels. In the nabilone vs. placebo study, when compared with placebo, nabilone resulted in significantly elevated post-dose fasting GIP levels and post-OGTT GIP levels, but no change in post-dose fasting GLP-1 levels together with significantly lower post-OGTT GLP-1 levels. Glucose levels were not different with both interventions. We conclude that elevated GIP levels in obesity are likely a consequence of increased endocannabinoid levels. CBRs exert tonic control over GIP secretion, which may have a homeostatic effect in suppressing GLP-1 secretion. This raises the possibility that gut hormones are influenced by endocannabinoids. Topics: Adult; Blood Glucose; Cannabinoid Receptor Agonists; Case-Control Studies; Cross-Over Studies; Double-Blind Method; Dronabinol; Female; Gastric Inhibitory Polypeptide; Glucagon-Like Peptide 1; Glucose Tolerance Test; Humans; Incretins; Longitudinal Studies; Male; Middle Aged; Obesity; Prospective Studies; Receptors, Cannabinoid; Young Adult | 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 |
Effect of meal composition on postprandial glucagon-like peptide-1, insulin, glucagon, C-peptide, and glucose responses in overweight/obese subjects.
Glucagon-like peptide-1 (GLP-1), an incretin hormone, is released in response to food intake. It is unclear how meals high in protein (HP) and monounsaturated fat (HMF) affect GLP-1 response.. To examine the effect of a HP versus a HMF meal on GLP-1 response.. Twenty-four overweight/obese participants consumed two meals (HP: 31.9 % energy from protein; HMF: 35.2 % fat and 20.7 % monounsaturated fat) in a random order. Both meals contained the same energy and carbohydrate content. GLP-1, insulin, glucagon, C-peptide, and glucose were assessed from blood drawn in the fasting and postprandial states. The effect of meal condition on hormone and glucose responses and appetite ratings were assessed by repeated measures analysis.. Statistically significant (p < 0.01) time by meal condition effect was observed on active GLP-1, total GLP-1, insulin, C-peptide, and glucagon, but not glucose (p = 0.83). Area under the curve was significantly higher during the HP versus the HMF meal conditions for active GLP-1 (23.7 %; p = 0.0007), total GLP-1 (12.2 %; p < 0.0001), insulin (54.4 %; p < 0.0001), C-peptide (14.8 %; p < 0.0001), and glucagon (40.7 %; p < 0.0001). Blood glucose was not different between the HP versus HMF conditions (-4.8 %; p = 0.11). Insulin sensitivity was higher during the HMF versus HP conditions (Matsuda index mean difference: 16.3 %; p = 0.007). Appetite ratings were not different by meal condition.. GLP-1 and insulin responses were higher during the HP condition. However, no difference was found in blood glucose between conditions, and insulin sensitivity was higher during the HMF condition, indicating that a HMF meal may be optimal at regulating blood glucose in overweight/obese individuals without type 2 diabetes. Topics: Adolescent; Adult; Aged; Appetite; Blood Glucose; Body Mass Index; C-Peptide; Cross-Over Studies; Exercise; Female; Glucagon; Glucagon-Like Peptide 1; Humans; Insulin; Insulin Resistance; Male; Meals; Mental Recall; Middle Aged; Obesity; Overweight; Postprandial Period; Young Adult | 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 |
Effects of small intestinal glucose on glycaemia, insulinaemia and incretin hormone release are load-dependent in obese subjects.
Studies concerning the glycaemic response to oral glucose, or meals in obesity have usually failed to account for gastric emptying. It has been suggested that the incretin effect may be diminished in obesity as a result of a reduction in glucagon-like peptide-1 (GLP-1) secretion. We sought to determine the effect of two different rates of intraduodenal glucose infusions on glycaemic, insulinaemic and incretin hormone responses in lean and obese subjects and compare the effects of oral and intraduodenal glucose in obese subjects.. Eleven obese subjects (age 37.5±4.1 years, body mass index (BMI) 35.7±1.4 kg m. In both the groups (P<0.001), the incremental areas under the curve (iAUC). The rate of duodenal glucose delivery is a major determinant of glycaemia, insulinaemia and incretin hormone release in obese subjects. Obesity is not apparently associated with impaired GLP-1 secretion. Topics: Adult; Appetite Regulation; Blood Glucose; Body Mass Index; Duodenum; Enteral Nutrition; Female; Gastric Emptying; Gastric Inhibitory Polypeptide; Gastrointestinal Motility; Glucagon-Like Peptide 1; Glucose; Glucose Tolerance Test; Humans; Incretins; Male; Obesity; Postprandial Period | 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 |
Does GLP-1 suppress its own basal secretion?
Negative feedback controls in endocrine regulatory systems are well recognized. The incretins and their role in glucose regulation have been of major interest recently. Whether the same negative control system applies to the regulation of incretin secretion is not clear. We sought to examine the hypothesis that exogenous administration of glucagon like peptide-1, GLP-1(7-36) amide or its metabolite GLP-1(9-36) amide, reduces the endogenous basal release of this incretin.. We evaluated the endogenous basal release of GLP-1 using two separate study designs. In protocol A we examined the GLP-1(7-36) amide levels during the infusion of GLP-1(9-36) amide. In protocol B, we used PYY and GLP-2 as biomarkers for the endogenous basal release of GLP-1(7-36) amide and assessed the endogenous basal release of these two hormones during the GLP-1(7-36) infusion. Twelve lean and 12 obese subjects were enrolled in protocol A and 10 obese volunteers in protocol B.. The plasma levels of GLP-1(7-36) amide in protocol A and PYY and GLP-2 in protocol B remained unchanged during the exogenous infusion of GLP-1(9-36) and GLP-1(7-36) amide, respectively.. The negative feedback control system as described by inhibition of the release of endogenous hormone while infusing it exogenously was not observed for the basal secretion of GLP-1(7-36) amide. Topics: Adult; Basal Metabolism; Blood Glucose; Feedback, Physiological; Female; Glucagon; Glucagon-Like Peptide 1; Humans; Insulin; Male; Obesity; Peptide Fragments; Peptides; Thinness | 2016 |
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 |
A multifunctional diet improves cardiometabolic-related biomarkers independently of weight changes: an 8-week randomized controlled intervention in healthy overweight and obese subjects.
A multifunctional diet (MFD) was previously shown to reduce blood lipids, CRP and blood pressure in a 4-week intervention under weight-maintenance conditions. Here, MFD effects were evaluated in an 8-week intervention with no restriction for weight changes.. Healthy subjects consumed MFD (23 subjects) or a control diet (CD) devoid of the functional components (24 subjects) in a "free-living" randomized controlled experiment. MFD included several functional concepts: low-glycemic-impact meals, antioxidant-rich foods, oily fish, viscous dietary fibers, soybean and whole barley kernel products, almonds and plant stanols. Measured outcomes were fasting blood values of lipids, glucose, insulin, GGT, CRP, HbA1c, PAI-1, GLP-1, GLP-2, body weight, blood pressure and breath hydrogen.. At baseline, participants were 51-72 years old, with BMI between 25 and 34 and fasting glycemia ≤ 6.1 mmol/L. Consumption of both diets resulted in similar weight loss after 8 weeks (-4 %; P < 0.001). Compared to baseline, consumption of MFD reduced total serum cholesterol (-26 %; P < 0.0001), LDL cholesterol (-35 %; P < 0.0001), triglycerides (-16 %; P < 0.05), LDL/HDL (-27 %; P < 0.0001) and ApoB/ApoA1 (-15 %; P < 0.0001). There were important net differences between diets, which remained significant after adjustment for body weight. Reduced systolic blood pressure, circulating GGT, HbA1c and insulin concentrations were observed with both MFD and CD with no difference between diets. The Reynolds cardiovascular risk score was decreased by 36 % (P < 0.0001) with MFD. MFD increased breath hydrogen levels (120 %; P < 0.05).. Consumption of MFD decreased blood lipids and improved several other aspects of the cardiometabolic risk profile. This effect was not dependent on weight loss. Topics: Aged; Biomarkers; Blood Glucose; Blood Pressure; Body Mass Index; Body Weight; C-Reactive Protein; Cardiovascular Diseases; Cross-Over Studies; Diet; Female; gamma-Glutamyltransferase; Glucagon-Like Peptide 1; Glucagon-Like Peptide 2; Glycated Hemoglobin; Humans; Insulin; Lipids; Male; Metabolic Syndrome; Middle Aged; Obesity; Overweight; Plasminogen Activator Inhibitor 1; Risk Factors; Waist Circumference | 2016 |
Plasma acyl-ghrelin increases after meal initiation: a new insight.
Plasma ghrelin secretion over time in humans is characterized by pre-prandial increases and by post-prandial decreases all day long. However, some authors who measured ghrelin concentrations around meals showed a rise in plasma ghrelin concentration after meal initiation followed by the typical post-prandial decrease. In order to confirm this observation that has never been discussed, we described ghrelin profiles around four eating episodes in the morning in adult men.. Twenty normal-weight and 17 obese men were instructed to eat four fixed meals (706 kJ) 10 min long at 0800 h, 0900 h, 1000 h and 1100 h. Using frequent blood sampling, we determined plasma acyl-ghrelin concentrations around those eating episodes. Glucose, insulin and GLP-1 concentrations were also measured.. The meals consumption induced a significant increase in plasma acyl-ghrelin concentrations 10 min after meal initiation (P<0.0001): +20.9±5.8 and +10.7±3.3 pg/ml in normal-weight and obese subjects for the first meal; +10.4±3.0 and +5.5±3.9 pg/ml in normal-weight and obese subjects for the second meal; +12.4±3.6 and +4.2±2.1 pg/ml in normal-weight and obese subjects for the third meal; and +4.4±4.1 and +3.3±2.61 pg/ml in normal-weight and obese subjects for the fourth meal.. This study is the first to describe and discuss the post-meal initiation ghrelin increase. This finding is consistent in normal-weight and obese individuals. Topics: Adult; Blood Glucose; Body Mass Index; Eating; Fasting; Ghrelin; Glucagon-Like Peptide 1; Humans; Insulin; Male; Meals; Obesity; Postprandial Period; Reference Values | 2016 |
Minor Contribution of Endogenous GLP-1 and GLP-2 to Postprandial Lipemia in Obese Men.
Glucose and lipids stimulate the gut-hormones glucagon-like peptide (GLP)-1, GLP-2 and glucose-dependent insulinotropic polypeptide (GIP) but the effect of these on human postprandial lipid metabolism is not fully clarified.. To explore the responses of GLP-1, GLP-2 and GIP after a fat-rich meal compared to the same responses after an oral glucose tolerance test (OGTT) and to investigate possible relationships between incretin response and triglyceride-rich lipoprotein (TRL) response to a fat-rich meal.. Glucose, insulin, GLP-1, GLP-2 and GIP were measured after an OGTT and after a fat-rich meal in 65 healthy obese (BMI 26.5-40.2 kg/m(2)) male subjects. Triglycerides (TG), apoB48 and apoB100 in TG-rich lipoproteins (chylomicrons, VLDL1 and VLDL2) were measured after the fat-rich meal.. Postprandial responses (area under the curve, AUC) for glucose, insulin, GLP-1, GLP-2, GIP in plasma, and TG, apoB48 and apoB100 in plasma and TG-rich lipoproteins.. The GLP-1, GLP-2 and GIP responses after the fat-rich meal and after the OGTT correlated strongly (r = 0.73, p<0.0001; r = 0.46, p<0.001 and r = 0.69, p<0.001, respectively). Glucose and insulin AUCs were lower, but the AUCs for GLP-1, GLP-2 and GIP were significantly higher after the fat-rich meal than after the OGTT. The peak value for all hormones appeared at 120 minutes after the fat-rich meal, compared to 30 minutes after the OGTT. After the fat-rich meal, the AUCs for GLP-1, GLP-2 and GIP correlated significantly with plasma TG- and apoB48 AUCs but the contribution was very modest.. In obese males, GLP-1, GLP-2 and GIP responses to a fat-rich meal are greater than following an OGTT. However, the most important explanatory variable for postprandial TG excursion was fasting triglycerides. The contribution of endogenous GLP-1, GLP-2 and GIP to explaining the variance in postprandial TG excursion was minor. Topics: Adult; Aged; Apolipoprotein B-100; Apolipoprotein B-48; Area Under Curve; Blood Glucose; Chylomicrons; Dietary Fats; Gastric Inhibitory Polypeptide; Glucagon-Like Peptide 1; Glucagon-Like Peptide 2; Glucose Tolerance Test; Humans; Hyperlipidemias; Incretins; Lipid Metabolism; Male; Meals; Middle Aged; Obesity; Postprandial Period; Triglycerides | 2016 |
Effects of endogenous GLP-1 and GIP on glucose tolerance after Roux-en-Y gastric bypass surgery.
Exaggerated secretion of glucagon-like peptide 1 (GLP-1) is important for postprandial glucose tolerance after Roux-en-Y gastric bypass (RYGB), whereas the role of glucose-dependent insulinotropic polypeptide (GIP) remains to be resolved. We aimed to explore the relative importance of endogenously secreted GLP-1 and GIP on glucose tolerance and β-cell function after RYGB. We used DPP-4 inhibition to enhance concentrations of intact GIP and GLP-1 and the GLP-1 receptor antagonist exendin-(9-39) (Ex-9) for specific blockage of GLP-1 actions. Twelve glucose-tolerant patients were studied after RYGB in a randomized, placebo-controlled, 4-day crossover study with standard mixed-meal tests and concurrent administration of placebo, oral sitagliptin, Ex-9 infusion, or combined Ex-9-sitagliptin. GLP-1 receptor antagonism increased glucose excursions, clearly attenuated β-cell function, and aggravated postprandial hyperglucagonemia compared with placebo, whereas sitagliptin had no effect despite two- to threefold increased concentrations of intact GLP-1 and GIP. Similarly, sitagliptin did not affect glucose tolerance or β-cell function during GLP-1R blockage. This study confirms the importance of GLP-1 for glucose tolerance after RYGB via increased insulin and attenuated glucagon secretion in the postprandial state, whereas amplification of the GIP signal (or other DPP-4-sensitive glucose-lowering mechanisms) did not appear to contribute to the improved glucose tolerance seen after RYGB. Topics: Adult; Blood Glucose; C-Peptide; Cross-Over Studies; Enzyme-Linked Immunosorbent Assay; Female; Gastric Bypass; Gastric Inhibitory Polypeptide; Glucagon; Glucagon-Like Peptide 1; Glucagon-Like Peptide-1 Receptor; Glucose Tolerance Test; Humans; Hypoglycemic Agents; Linear Models; Male; Obesity; Peptide Fragments; Postprandial Period; Single-Blind Method; Sitagliptin Phosphate | 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 |
Mechanisms Regulating Insulin Response to Intragastric Glucose in Lean and Non-Diabetic Obese Subjects: A Randomized, Double-Blind, Parallel-Group Trial.
The changes in blood glucose concentrations that result from an oral glucose challenge are dependent on the rate of gastric emptying, the rate of glucose absorption and the rate of insulin-driven metabolism that include the incretins, glucose-dependent insulinotropic peptide (GIP) and glucagon-like peptide-1 (GLP-1). The rate of insulin-driven metabolism is clearly altered in obese subjects, but it is controversial which of these factors is predominant. We aimed to quantify gastric emptying, plasma insulin, C-peptide, glucagon and glucose responses, as well as incretin hormone secretions in obese subjects and healthy controls during increasing glucose loads.. The study was conducted as a randomized, double-blind, parallel-group trial in a hospital research unit. A total of 12 normal weight (6 men and 6 women) and 12 non-diabetic obese (BMI > 30, 6 men and 6 women) participants took part in the study. Subjects received intragastric loads of 10 g, 25 g and 75 g glucose dissolved in 300 ml tap water.. Main outcome measures were plasma GLP-1 and GIP, plasma glucagon, glucose, insulin, C-peptide and gastric emptying. The primary findings are: i) insulin resistance (P < 0.001) and hyperinsulinemia (P < 0.001); ii) decreased insulin disposal (P < 0.001); iii) trend for reduced GLP-1 responses at 75 g glucose; and iv) increased fasting glucagon levels (P < 0.001) in obese subjects.. It seems that, rather than changes in incretin secretion, fasting hyperglucagonemia and consequent hyperglycemia play a role in reduced disposal of insulin, contributing to hyperinsulinemia and insulin resistance.. ClinicalTrials.gov NCT01875575. Topics: Adult; Blood Glucose; Body Mass Index; Body Weight; C-Peptide; Case-Control Studies; Diabetes Mellitus; Double-Blind Method; Female; Gastric Emptying; Gastric Inhibitory Polypeptide; Glucagon; Glucagon-Like Peptide 1; Glucose; Humans; Incretins; Insulin; Insulin Resistance; Male; Middle Aged; Obesity; Young Adult | 2016 |
[GLP-1 agonist supports weight loss].
Topics: Glucagon-Like Peptide 1; Humans; Liraglutide; Obesity; Prediabetic State; Weight Loss | 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 |
Combination of soya protein and polydextrose reduces energy intake and glycaemic response via modulation of gastric emptying rate, ghrelin and glucagon-like peptide-1 in Chinese.
The short-term effect of soya protein, polydextrose and their combination on energy intake (EI) was investigated in Chinese. In total, twenty-seven healthy, normotensive and lean Chinese men aged 21-40 years were given four different soyabean curd preloads with or without polydextrose. The study was a repeated-measure, randomised, cross-over design. The consumption of high-protein soyabean curd alone or in addition with polydextrose as a preload led to greater reduction in EI at a subsequent meal. A similar observation was also found after intake of low-protein soyabean curd with polydextrose. The gut hormone responses mirrored the reduction in food intake. It appears that incorporation of polydextrose either with low- or high-protein soyabean curd could be a potential strategy to reduce EI and assist with weight management. The popular consumption of soyabean curd in Chinese makes it an ideal vehicle for incorporation of polydextrose. This evidence-based dietary approach can serve as a guideline for developing functional foods for weight reduction and weight maintenance. Topics: Adult; Appetite; Blood Glucose; China; Cross-Over Studies; Dietary Carbohydrates; Dietary Proteins; Eating; Energy Intake; Functional Food; Gastric Emptying; Gastrointestinal Hormones; Ghrelin; Glucagon-Like Peptide 1; Glucans; Glycemic Index; Humans; Male; Meals; Obesity; Soybean Proteins; Weight Loss; Young Adult | 2016 |
Liraglutide 3.0 mg for Weight Management: A Population Pharmacokinetic Analysis.
This analysis used a population pharmacokinetic approach to identify covariates that influence plasma exposure of liraglutide 3.0 mg, a glucagon-like peptide-1 (GLP-1) receptor agonist approved for weight management in overweight and obese individuals.. Samples for pharmacokinetic analysis were drawn at weeks 2, 12 and 28 of the phase IIIa SCALE Obesity and Prediabetes (N = 2339) and SCALE Diabetes (N = 584) trials. Dose proportionality of liraglutide in obese subjects was investigated using data from a phase II dose-finding study (N = 331).. Dose-proportional exposure of liraglutide up to and including 3.0 mg was confirmed. Body weight and sex influenced exposure of liraglutide 3.0 mg, while age ≥70 years, race, ethnicity and baseline glycaemic status did not. Compared with a reference subject weighing 100 kg, exposure of liraglutide 3.0 mg was 44 % lower for a subject weighing 234 kg (90 % CI 41-47), 41 % higher for a subject weighing 60 kg (90 % CI 37-46), and 32 % higher (90 % CI 28-35) in females than males with the same body weight. Neither injection site nor renal function significantly influenced exposure of liraglutide 3.0 mg (post hoc analysis).. Population pharmacokinetics of liraglutide up to and including 3.0 mg daily in overweight and obese adults demonstrated dose-proportional exposure, and limited effect of covariates other than sex and body weight. These findings were similar to those previously observed with liraglutide up to 1.8 mg in subjects with type 2 diabetes mellitus. Further analysis of exposure-response relationship and its effect on dose requirements is addressed in a separate publication. Topics: Adolescent; Adult; Age Factors; Aged; Body Weight; Dose-Response Relationship, Drug; Female; Glucagon-Like Peptide 1; Humans; Hypoglycemic Agents; Liraglutide; Male; Middle Aged; Models, Biological; Obesity; Overweight; Prediabetic State; Sex Factors; Young Adult | 2016 |
Mycoprotein reduces energy intake and postprandial insulin release without altering glucagon-like peptide-1 and peptide tyrosine-tyrosine concentrations in healthy overweight and obese adults: a randomised-controlled trial.
Dietary mycoprotein decreases energy intake in lean individuals. The effects in overweight individuals are unclear, and the mechanisms remain to be elucidated. This study aimed to investigate the effect of mycoprotein on energy intake, appetite regulation, and the metabolic phenotype in overweight and obese volunteers. In two randomised-controlled trials, fifty-five volunteers (age: 31 (95 % CI 27, 35) years), BMI: 28·0 (95 % CI 27·3, 28·7) kg/m2) consumed a test meal containing low (44 g), medium (88 g) or high (132 g) mycoprotein or isoenergetic chicken meals. Visual analogue scales and blood samples were collected to measure appetite, glucose, insulin, peptide tyrosine-tyrosine (PYY) and glucagon-like peptide-1 (GLP-1). Ad libitum energy intake was assessed after 3 h in part A (n 36). Gastric emptying by the paracetamol method, resting energy expenditure and substrate oxidation were recorded in part B (n 14). Metabonomics was used to compare plasma and urine samples in response to the test meals. Mycoprotein reduced energy intake by 10 % (280 kJ (67 kcal)) compared with chicken at the high content (P=0·009). All mycoprotein meals reduced insulin concentrations compared with chicken (incremental AUClow (IAUClow): -8 %, IAUCmedium: -12 %, IAUChigh: -21 %, P=0·004). There was no significant difference in glucose, PYY, GLP-1, gastric emptying rate and energy expenditure. Following chicken intake, paracetamol-glucuronide was positively associated with fullness. After mycoprotein, creatinine and the deamination product of isoleucine, α-keto-β-methyl-N-valerate, were inversely related to fullness, whereas the ketone body, β-hydroxybutyrate, was positively associated. In conclusion, mycoprotein reduces energy intake and insulin release in overweight volunteers. The mechanism does not involve changes in PYY and GLP-1. The metabonomics analysis may bring new understanding to the appetite regulatory properties of food. Topics: Adult; Animals; Appetite; Appetite Regulation; Dietary Proteins; Dipeptides; Eating; Energy Intake; Female; Fungal Proteins; Fusarium; Gastric Emptying; Gastrointestinal Hormones; Glucagon-Like Peptide 1; Humans; Insulin; Male; Middle Aged; Obesity; Peptide YY; Postprandial Period; Poultry; Satiation; Young Adult | 2016 |
No effect of 24 h severe energy restriction on appetite regulation and ad libitum energy intake in overweight and obese males.
Long-term success of weight loss diets might depend on how the appetite regulatory system responds to energy restriction (ER). This study determined the effect of 24 h severe ER on subjective and hormonal appetite regulation, subsequent ad libitum energy intake and metabolism.. In randomised order, eight overweight or obese males consumed a 24 h diet containing either 100% (12105 (1174 kJ; energy balance; EB) or 25% (3039 (295) kJ; ER) of estimated daily energy requirements (EER). An individualised standard breakfast containing 25% of EER (3216 (341) kJ) was consumed the following morning and resting energy expenditure, substrate utilisation and plasma concentrations of acylated ghrelin, glucagon-like peptide-1 (GLP-1. These results suggest that 24 h severe ER does not affect appetite regulation or energy intake in the subsequent 48 h. This style of dieting may be conducive to maintenance of a negative EB by limiting compensatory eating behaviour, and therefore may assist with weight loss. Topics: Acylation; Adult; Appetite; Appetite Regulation; Blood Glucose; Body Mass Index; Caloric Restriction; Energy Intake; Energy Metabolism; Feeding Behavior; Ghrelin; Glucagon-Like Peptide 1; Humans; Male; Obesity; Postprandial Period; Prospective Studies; United Kingdom | 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 |
Failure of sucrose replacement with the non-nutritive sweetener erythritol to alter GLP-1 or PYY release or test meal size in lean or obese people.
There is considerable interest in the effect of foods containing high intensity sweeteners on satiation. However, less is known about low-calorie bulk sweeteners such as erythritol. In this randomized three-way crossover study, we studied 10 lean and 10 obese volunteers who consumed three test meals on separate occasions: (a) control sucrose meal; (b) isovolumic meal with partial replacement of sucrose by erythritol; (c) isocaloric meal which contained more erythritol but equivalent calories to the control meal. We measured gut hormone levels, hunger and satiety scores, ad libitum food intake, sucrose preference and intake after the manipulations. There was a greater post-prandial excursion in glucose and insulin levels after sucrose than after the erythritol meals. There was no difference in GLP-1/PYY levels or subsequent energy intake and sucrose preference between sucrose control and isovolumic erythritol meals. In lean (but not obese) participants, hunger decreased to a greater extent after the isocaloric erythritol meal compared to the control meal (p = 0.003) reflecting the larger volume of this meal. Replacing sucrose with erythritol leads to comparable hunger and satiety scores, GLP-1 and PYY levels, and subsequent sucrose preference and intake. Topics: Adult; Cross-Over Studies; Erythritol; Female; Glucagon-Like Peptide 1; Humans; Hunger; Male; Meals; Middle Aged; Non-Nutritive Sweeteners; Obesity; Peptide YY; Postprandial Period; Satiation; Sucrose; Sweetening Agents | 2016 |
Effect of L-Tryptophan and L-Leucine on Gut Hormone Secretion, Appetite Feelings and Gastric Emptying Rates in Lean and Non-Diabetic Obese Participants: A Randomized, Double-Blind, Parallel-Group Trial.
Gut hormones such as cholecystokinin (CCK) and glucagon-like peptide-1 (GLP-1) play a role as satiation factors. Strategies to enhance satiation peptide secretion could provide a therapeutic approach for obesity. Carbohydrates and lipids have been extensively investigated in relation to peptide release. In contrast, the role of proteins or amino acids is less clear. Our aim was to compare the effects of the amino acids L-tryptophan (L-trp) and L-leucine (L-leu) separately on gastric emptying and gut peptide secretion.. The study was conducted as a randomized (balanced), double-blind, parallel-group trial. A total of 10 lean and 10 non-diabetic obese participants were included. Participants received intragastric loads of L-trp (0.52 g and 1.56 g) and L-leu (1.56 g), dissolved in 300 mL tap water; 75 g glucose and 300 mL tap water served as control treatments.. Results of the study are: i) L-trp at the higher dose stimulates CCK release (p = 0.0018), and induces a significant retardation in gastric emptying (p = 0.0033); ii) L-trp at the higher dose induced a small increase in GLP-1 secretion (p = 0.0257); iii) neither of the amino acids modulated subjective appetite feelings; and iv) the two amino acids did not alter insulin or glucose concentrations.. L-trp is a luminal regulator of CCK release with effects on gastric emptying, an effect that could be mediated by CCK. L-trp's effect on GLP-1 secretion is only minor. At the doses given, the two amino acids did not affect subjective appetite feelings.. ClinicalTrials.gov NCT02563847. Topics: Adult; Appetite; Cholecystokinin; Double-Blind Method; Female; Gastric Emptying; Glucagon-Like Peptide 1; Humans; Leucine; Male; Middle Aged; Obesity; Tryptophan | 2016 |
Effect of moderate- and high-intensity acute exercise on appetite in obese individuals.
The effect of acute exercise, and exercise intensity, on appetite control in obese individuals requires further study. The aim of this study was to compare the effects of acute isocaloric bouts (250 kcal) of high-intensity intermittent cycling (HIIC) and moderate-intensity continuous cycling (MICC) or short-duration HIIC (S-HIIC) (125 kcal) and a resting control condition on the appetite hormone responses, subjective feelings of appetite, energy intake (EI), and food reward in overweight/obese individuals.. This study is a randomized crossover study on 12 overweight/obese volunteers. Participants were assigned to the control, MICC, HIIC, and S-HIIC conditions, 1 wk apart, in a counterbalanced order. Exercise was performed 1 h after a standard breakfast. An ad libitum test lunch was served 3 h after breakfast. Fasting/postprandial plasma samples of insulin, acylated ghrelin, polypeptide YY3-36, and glucagon-like peptide 1 and subjective feelings of appetite were measured every 30 min for 3 h. Nutrient and taste preferences were measured at the beginning and end of each condition using the Leeds Food Preference Questionnaire.. Insulin levels were significantly reduced, and glucagon-like peptide 1 levels significantly increased during all exercise bouts compared with those during rest. Acylated ghrelin plasma levels were lower in the MICC and HIIC, but not in S-HIIC, compared with those in control. There were no significant differences for polypeptide YY3-36 plasma levels, hunger or fullness ratings, EI, or food reward.. Our findings suggest that, in overweight/obese individuals, isocaloric bouts of moderate- or high-intensity exercise lead to a similar appetite response. This strengthens previous findings in normal-weight individuals that acute exercise, even at high intensity, does not induce any known physiological adaptation that would lead to increased EI. Topics: Acylation; Adult; Appetite; Cross-Over Studies; Energy Intake; Exercise; Female; Food Preferences; Ghrelin; Glucagon-Like Peptide 1; Humans; Insulin; Male; Obesity; Peptide Fragments; Peptide YY; Physical Exertion; Reward; Taste; Young Adult | 2015 |
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 |
Acute decrease in serum testosterone after a mixed glucose and protein beverage in obese peripubertal boys.
Delayed puberty and lower levels of testosterone (T) have been observed in adult obese males and some adolescent males. In adult men, enteral glucose ingestion results in acute lowering of serum testosterone levels; however, this has not been studied in adolescents. We aimed to examine the acute effect of a glucose/protein beverage on serum T concentration changes in obese peripubertal males. A second objective was to determine whether change in T concentration was related to appetite hormone levels.. Twenty-three overweight and obese males aged 8-17 in pre-early (Tanner stage 1-2) and mid-late (Tanner stage 3-5) puberty were included in this cross-sectional study at the Clinical investigative unit at the Hospital for Sick Children. Participants consumed a beverage containing glucose and protein, and blood samples measuring pubertal hormones, ghrelin and glucagon-like peptide-1 (GLP-1) were taken over 60 min.. Across pubertal stages, there was a significant decrease in T levels in adolescent boys (-18·6 ± 3·1%, P < 0·01) with no proportional differences between pre-early and mid-late puberty (P = 0·09). Decrease in T was associated with a decrease in LH (r = 0·52, P = 0·02), and fasting T was inversely correlated with fasting ghrelin (r = -0·51, P = 0·03) with no correlation with GLP-1.. Intake of a mixed glucose/protein beverage acutely decreases T levels in overweight and obese peripubertal boys. A potential mechanism for this decrease may be secondary to an acute decrease in LH, but this requires further evaluation. Topics: Adolescent; Analysis of Variance; Beverages; Child; Cross-Sectional Studies; Fasting; Ghrelin; Glucagon-Like Peptide 1; Glucose; Humans; Luteinizing Hormone; Male; Obesity; Puberty; Testosterone; Whey Proteins | 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 |
Quantitative gastrointestinal and psychological traits associated with obesity and response to weight-loss therapy.
Weight loss after pharmacotherapy varies greatly. We aimed to examine associations of quantitative gastrointestinal and psychological traits with obesity, and to validate the ability of these traits to predict responses of obese individuals to pharmacotherapy.. In a prospective study, we measured gastric emptying of solids and liquids, fasting and postprandial gastric volume, satiation by nutrient drink test (volume to fullness and maximal tolerated volume), satiety after an ad libitum buffet meal, gastrointestinal hormones, and psychological traits in 328 normal-weight, overweight, or obese adults. We also analyzed data from 181 previously studied adults to assess associations betwecen a subset of traits with body mass index and waist circumference. Latent dimensions associated with overweight or obesity were appraised by principal component analyses. We performed a proof of concept, placebo-controlled trial of extended-release phentermine and topiramate in 24 patients to validate associations between quantitative traits and response to weight-loss therapy.. In the prospective study, obesity was associated with fasting gastric volume (P = .03), accelerated gastric emptying (P < .001 for solids and P = .011 for liquids), lower postprandial levels of peptide tyrosine tyrosine (P = .003), and higher postprandial levels of glucagon-like peptide 1 (P < .001). In a combined analysis of data from all studies, obesity was associated with higher volume to fullness (n = 509; P = .038) and satiety with abnormal waist circumference (n = 271; P = .016). Principal component analysis identified latent dimensions that accounted for approximately 81% of the variation among overweight and obese subjects, including satiety or satiation (21%), gastric motility (14%), psychological factors (13%), and gastric sensorimotor factors (11%). The combination of phentermine and topiramate caused significant weight loss, slowed gastric emptying, and decreased calorie intake; weight loss in response to phentermine and topiramate was significantly associated with calorie intake at the prior satiety test.. Quantitative traits are associated with high body mass index; they can distinguish obesity phenotypes and, in a proof of concept clinical trial, predicted response to pharmacotherapy for obesity. ClinicalTrials.gov Number: NCT01834404. Topics: Adult; Aged; Anti-Obesity Agents; Anxiety; Body Image; Body Mass Index; Cholecystokinin; Cohort Studies; Delayed-Action Preparations; Depression; Dipeptides; Drug Combinations; Fasting; Female; Fructose; Gastric Emptying; Ghrelin; Glucagon-Like Peptide 1; Humans; Male; Middle Aged; Obesity; Organ Size; Overweight; Peptide YY; Phentermine; Postprandial Period; Principal Component Analysis; Prospective Studies; Satiation; Self Efficacy; Stomach; Topiramate; Treatment Outcome | 2015 |
Postprandial effects of polydextrose on satiety hormone responses and subjective feelings of appetite in obese participants.
Dietary fibers are associated with enhanced satiety. However, the mechanism of different dietary fibers contributing to satiety-related gastrointestinal (GI) peptide release, especially in an obese population, is still poorly understood. Polydextrose (PDX), a water-soluble glucose polymer, has demonstrated its ability to reduce energy intake at a subsequent meal, but its mechanism of action requires further research. Also, there is limited evidence on its capacity to regulate subjective feelings of appetite. This study examines the effects of PDX on postprandial secretion of satiety-related GI peptides, short chain fatty acids (SCFAs), lactic acid, and subjective appetite ratings in obese participants.. 18 non-diabetic, obese participants (42.0 y, 33.6 kg/m2) consumed a high-fat meal (4293 kJ, 36% from fat) with or without PDX (15 g) in an acute, multicenter, randomized, double-blind, placebo-controlled and crossover trial. Postprandial plasma concentrations of satiety-related peptides, namely ghrelin, cholecystokinin (CCK), glucagon-like peptide 1 (GLP-1), and peptide YY (PYY), as well as SCFAs and lactic acid were assessed. GI peptide, SCFA and lactate concentrations were then modeled using a linear mixed-effects model.The subjective feelings of hunger, satisfaction, and desire to eat were evaluated using visual analogue scales (VAS), which were analyzed as incremental areas under the curve (iAUC) during the satiation and satiety periods.. We found that PDX supplementation increased plasma GLP-1 levels more than the placebo treatment (P = 0.02). In the whole group, GLP-1 concentrations found in participants older than 40 years old were significantly lower (P = 0.01) as compared to those aged 40 years or less. There were no statistically significant differences in postprandial ghrelin, CCK, or PYY responses. The lactic acid concentrations were significantly (P = 0.01) decreased in the PDX group, while no significant changes in SCFAs were found. PDX reduced iAUC for hunger by 40% (P = 0.03) and marginally increased satisfaction by 22.5% (P = 0.08) during the post-meal satiety period.. Polydextrose increased the postprandial secretion of the satiety hormone GLP-1 and reduced hunger after a high-fat meal. PDX also reduced the elevated postprandial lactic acid levels in plasma. Therefore, PDX may offer an additional means to regulate inter-meal satiety and improve postprandial metabolism in obese participants. Topics: Adult; Age Factors; Body Mass Index; Cholecystokinin; Cross-Over Studies; Dietary Fats; Dietary Fiber; Double-Blind Method; Fatty Acids, Volatile; Female; Ghrelin; Glucagon-Like Peptide 1; Glucans; Humans; Lactic Acid; Male; Middle Aged; Obesity; Peptide YY; Placebos; Postprandial Period; Satiation | 2015 |
β-Cell Sensitivity to GLP-1 in Healthy Humans Is Variable and Proportional to Insulin Sensitivity.
Glucagon-like peptide-1 (GLP-1) is an insulinotropic factor made in the gastrointestinal tract that is essential for normal glucose tolerance. Infusion of GLP-1 increases insulin secretion in both diabetic and nondiabetic humans. However, the degree to which people vary in their β-cell sensitivity to GLP-1 and the factors contributing to this variability have not been reported.. The objective was to measure the sensitivity of insulin secretion to GLP-1 in cohorts of lean and obese subjects across a broad range of insulin sensitivity.. Insulin secretion was measured during clamped hyperglycemia (7.2 mmol/L) and graded GLP-1 infusion in young, healthy subjects, and GLP-1 sensitivity was computed from the insulin secretion rate (ISR) during progressive increases in plasma GLP-1.. All subjects had fasting glucose values <5.2 mm. The obese subjects were insulin resistant compared to the lean group (homeostasis model of assessment 2 for insulin resistance: obese, 2.6 ± 0.5; lean, 0.8 ± 0.1; P < .001). ISR increased linearly in both cohorts with escalating doses of GLP-1, but the slope of ISR in response to GLP-1 was greater in the obese than in the lean subjects (obese, 0.17 ± 0.03 nmol/min/pm; lean, 0.05 ± 0.01 nmol/min/pm; P < .001). There was a significant association of β-cell GLP-1 sensitivity and insulin resistance (r = 0.83; P < .001), and after correction for homeostasis model of assessment 2 for insulin resistance, the slopes of ISR vs GLP-1 concentration did not differ in the two cohorts (obese, 0.08 ± 0.01; lean, 0.08 ± 0.01; P = .98). However, within the entire study group, β-cell GLP-1 sensitivity corrected for insulin resistance varied nearly 10-fold.. Insulin secretion in response to GLP-1 is proportional to insulin resistance in healthy subjects. However, there is considerable variability in the sensitivity of the β-cell to GLP-1 that is independent of insulin sensitivity. Topics: Adult; Blood Glucose; Drug Resistance; Female; Glucagon-Like Peptide 1; Glucose Clamp Technique; Health; Humans; Insulin; Insulin Resistance; Insulin Secretion; Insulin-Secreting Cells; Male; Obesity; Thinness; Young Adult | 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 |
Polyphenol-rich diets improve glucose metabolism in people at high cardiometabolic risk: a controlled randomised intervention trial.
Dietary polyphenols and long chain n-3 polyunsaturated fatty acids (LCn3) are associated with lower cardiovascular risk. This may relate to their influence on glucose metabolism and diabetes risk. We evaluated the effects of diets naturally rich in polyphenols and/or LCn3 of marine origin on glucose metabolism in people at high cardiometabolic risk.. According to a 2 × 2 factorial design, individuals with high waist circumference and at least one more component of the metabolic syndrome were recruited at the obesity outpatient clinic. Eighty-six participants were randomly assigned by MINIM software to an isoenergetic diet: (1) control, low in LCn3 and polyphenol (analysed n = 20); (2) rich in LCn3 (n = 19); (3) rich in polyphenols (n = 19); or (4) rich in LCn3 and polyphenols (n = 19). The assigned diets were known for the participants and blinded for people doing measurements. Before and after the 8 week intervention, participants underwent a 3 h OGTT and a test meal with a similar composition as the assigned diet for the evaluation of plasma glucose, insulin and glucagon-like peptide 1 (GLP-1) concentrations, and indices of insulin sensitivity and beta cell function.. During OGTT, polyphenols significantly reduced plasma glucose total AUC (p = 0.038) and increased early insulin secretion (p = 0.048), while LCn3 significantly reduced beta cell function (p = 0.031) (two-factor ANOVA). Moreover, polyphenols improved post-challenge oral glucose insulin sensitivity (OGIS; p = 0.05 vs control diet by post hoc ANOVA). At test meal, LCn3 significantly reduced GLP-1 total postprandial AUC (p < 0.001; two-factor ANOVA).. Diets naturally rich in polyphenols reduce blood glucose response, likely by increasing early insulin secretion and insulin sensitivity. These effects may favourably influence diabetes and cardiovascular risk. The implications of the decrease in insulin secretion and postprandial GLP-1 observed with diets rich in marine LCn3 need further clarification.. ClinicalTrials.gov NCT01154478.. The trial was funded by European Community's Seventh Framework Programme FP7/2009-2012 under grant agreement FP7-KBBE-222639, Etherpaths Project and 'Ministero Istruzione Università e Ricerca' PRIN 2010-2011 - 2010JCWWKM. Topics: Adult; Aged; Blood Glucose; Cardiovascular Diseases; Diet; Fatty Acids, Omega-3; Female; Glucagon-Like Peptide 1; Glucose; Glucose Tolerance Test; Humans; Insulin; Insulin Resistance; Insulin-Secreting Cells; Male; Metabolic Diseases; Middle Aged; Obesity; Patient Compliance; Polyphenols; Waist Circumference | 2015 |
GLP-1 Receptor Agonist Treatment Increases Bone Formation and Prevents Bone Loss in Weight-Reduced Obese Women.
Recent studies indicate that glucagon-like peptide (GLP)-1 regulates bone turnover, but the effects of GLP-1 receptor agonists (GLP-1 RAs) on bone in obese weight-reduced individuals are unknown.. To investigate the role of GLP-1 RAs on bone formation and weight loss-induced bone mass reduction.. Randomized control study.. Outpatient research hospital clinic.. Thirty-seven healthy obese women with body mass index of 34 ± 0.5 kg/m(2) and age 46 ± 2 years.. After a low-calorie-diet-induced 12% weight loss, participants were randomized to treatment with or without administration of the GLP-1 RA liraglutide (1.2 mg/d) for 52 weeks. In case of weight gain, up to two meals per day could be replaced with a low-calorie-diet product to maintain the weight loss.. Total, pelvic, and arm-leg bone mineral content (BMC) and bone markers [C-terminal telopeptide of type 1 collagen (CTX-1) and N-terminal propeptide of type 1 procollagen (P1NP)] were investigated before and after weight loss and after 52-week weight maintenance. Primary endpoints were changes in BMC and bone markers after 52-week weight maintenance with or without GLP-1 RA treatment.. Total, pelvic, and arm-leg BMC decreased during weight maintenance in the control group (P < .0001), but not significantly in the liraglutide group. Thus, total and arm-leg BMC loss was four times greater in the control group compared to the liraglutide group (estimated difference, 27 g; 95% confidence interval, 5-48; P = .01), although the 12% weight loss was maintained in both groups. In the liraglutide group, the bone formation marker P1NP increased by 16% (7 ± 3 μg/L) vs a 2% (-1 ± 4 μg/L) decrease in the control group (P < .05). The bone resorption marker CTX-1 collagen did not change during the weight loss maintenance phase.. Treatment with a long-acting GLP-1 RA increased bone formation by 16% and prevented bone loss after weight loss obtained through a low-calorie diet, supporting its role as a safe weight-lowering agent. Topics: Adolescent; Adult; Aged; Bone Resorption; Caloric Restriction; Female; Glucagon-Like Peptide 1; Glucagon-Like Peptide-1 Receptor; Humans; Liraglutide; Middle Aged; Obesity; Osteogenesis; Receptors, Glucagon; Weight Loss; Young Adult | 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 |
A Randomized, Controlled Trial of 3.0 mg of Liraglutide in Weight Management.
Obesity is a chronic disease with serious health consequences, but weight loss is difficult to maintain through lifestyle intervention alone. Liraglutide, a glucagon-like peptide-1 analogue, has been shown to have potential benefit for weight management at a once-daily dose of 3.0 mg, injected subcutaneously.. We conducted a 56-week, double-blind trial involving 3731 patients who did not have type 2 diabetes and who had a body-mass index (BMI; the weight in kilograms divided by the square of the height in meters) of at least 30 or a BMI of at least 27 if they had treated or untreated dyslipidemia or hypertension. We randomly assigned patients in a 2:1 ratio to receive once-daily subcutaneous injections of liraglutide at a dose of 3.0 mg (2487 patients) or placebo (1244 patients); both groups received counseling on lifestyle modification. The coprimary end points were the change in body weight and the proportions of patients losing at least 5% and more than 10% of their initial body weight.. At baseline, the mean (±SD) age of the patients was 45.1±12.0 years, the mean weight was 106.2±21.4 kg, and the mean BMI was 38.3±6.4; a total of 78.5% of the patients were women and 61.2% had prediabetes. At week 56, patients in the liraglutide group had lost a mean of 8.4±7.3 kg of body weight, and those in the placebo group had lost a mean of 2.8±6.5 kg (a difference of -5.6 kg; 95% confidence interval, -6.0 to -5.1; P<0.001, with last-observation-carried-forward imputation). A total of 63.2% of the patients in the liraglutide group as compared with 27.1% in the placebo group lost at least 5% of their body weight (P<0.001), and 33.1% and 10.6%, respectively, lost more than 10% of their body weight (P<0.001). The most frequently reported adverse events with liraglutide were mild or moderate nausea and diarrhea. Serious events occurred in 6.2% of the patients in the liraglutide group and in 5.0% of the patients in the placebo group.. In this study, 3.0 mg of liraglutide, as an adjunct to diet and exercise, was associated with reduced body weight and improved metabolic control. (Funded by Novo Nordisk; SCALE Obesity and Prediabetes NN8022-1839 ClinicalTrials.gov number, NCT01272219.). Topics: Adult; Blood Glucose; Body Mass Index; Combined Modality Therapy; Counseling; Diarrhea; Diet, Reducing; Double-Blind Method; Exercise; Female; Glucagon-Like Peptide 1; Humans; Hypoglycemic Agents; Injections, Subcutaneous; Liraglutide; Male; Middle Aged; Nausea; Obesity; Weight Loss | 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 |
Hunger and satiety responses to high-fat meals of varying fatty acid composition in women with obesity.
Determine subjective and physiological appetite responses and ad libitum intake to high-fat (HF) meals rich in either monounsaturated (MUFAs), polyunsaturated (PUFAs), or saturated fatty acids (SFAs) in women with obesity.. In this single-blind crossover study, three HF meals (70% of energy) rich in MUFAs, PUFAs, or SFAs in 16 women with obesity were tested. At each visit, anthropometrics and a fasting blood sample were collected. Participants then consumed one of the HF meals, and postprandial blood draws and visual analog scale (VAS) measures were collected over 5 h. An ad libitum buffet lunch was provided 5 h after the HF meal.. Decrease in ghrelin was significantly greater for PUFA (P < 0.05) and MUFA (P < 0.01) vs. SFA while the increase in peptide YY was significantly greater for PUFA vs. both SFA and MUFA (P < 0.05). Change in glucagon-like peptide-1, VAS measurements, or total energy consumed at the buffet showed no differences between HF meals (ns).. Fatty acid composition differentially affected physiological markers of hunger and satiety. However, it was unable to show changes in subjective appetite ratings or changes in energy intake when alterations were made to fatty acid composition from an acute HF meal. Topics: Adult; Cross-Over Studies; Dietary Fats; Energy Intake; Fatty Acids; Fatty Acids, Monounsaturated; Fatty Acids, Unsaturated; Female; Ghrelin; Glucagon-Like Peptide 1; Humans; Obesity; Peptide YY; Postprandial Period; Satiation; Satiety Response; Single-Blind Method | 2015 |
Tolerability of nausea and vomiting and associations with weight loss in a randomized trial of liraglutide in obese, non-diabetic adults.
Liraglutide 3.0 mg, with diet and exercise, produced substantial weight loss over 1 year that was sustained over 2 years in obese non-diabetic adults. Nausea was the most frequent side effect.. To evaluate routinely collected data on nausea and vomiting among individuals on liraglutide and their influence on tolerability and body weight.. A randomized, placebo-controlled, double-blind 20-week study with an 84-week extension (sponsor unblinded at 20 weeks, open-label after 1 year) in eight European countries (Clinicaltrials.gov: NCT00422058).. After commencing a 500-kcal/day deficit diet plus exercise, 564 participants (18-65 years, body mass index (BMI) 30-40 kg m(-2)) were randomly assigned (after a 2-week run-in period) to once-daily subcutaneous liraglutide (1.2, 1.8, 2.4 or 3.0 mg), placebo or open-label orlistat (120 mg × 3 per day). After 1 year, participants on liraglutide/placebo switched to liraglutide 2.4 mg, and subsequently, to liraglutide 3.0 mg (based on 20-week and 1-year results, respectively).. The intention-to-treat population comprised 561 participants (n=90-98 per arm, age 45.9±10.3 years, BMI 34.8±2.7 kg m(-2) (mean±s.d.)). In year 1, more participants reported ⩾1 episode of nausea/vomiting on treatment with liraglutide 1.2-3.0 mg (17-38%) than with placebo or orlistat (both 4%, P⩽0.001). Most episodes occurred during dose escalation (weeks 1-6), with 'mild' or 'moderate' symptoms. Among participants on liraglutide 3.0 mg, 48% reported some nausea and 13% some vomiting, with considerable variation between countries, but only 4 out of 93 (4%) reported withdrawals. The mean 1-year weight loss on treatment with liraglutide 3.0 mg from randomization was 9.2 kg for participants reporting nausea/vomiting episodes, versus 6.3 kg for those with none (a treatment difference of 2.9 kg (95% confidence interval 0.5-5.3); P=0.02). Both weight losses were significantly greater than the respective weight losses for participants on placebo (P<0.001) or orlistat (P<0.05). Quality-of-life scores at 20 weeks improved similarly with or without nausea/vomiting on treatment with liraglutide 3.0 mg.. Transient nausea and vomiting on treatment with liraglutide 3.0 mg was associated with greater weight loss, although symptoms appeared tolerable and did not attenuate quality-of-life improvements. Improved data collection methods on nausea are warranted. Topics: Adolescent; Adult; Aged; Anti-Obesity Agents; Body Mass Index; Dose-Response Relationship, Drug; Double-Blind Method; Drug Administration Schedule; Europe; Female; Glucagon-Like Peptide 1; Humans; Liraglutide; Male; Middle Aged; Nausea; Obesity; Quality of Life; Severity of Illness Index; Treatment Outcome; Vomiting; Weight Loss | 2014 |
Effects of the once-daily GLP-1 analog liraglutide on gastric emptying, glycemic parameters, appetite and energy metabolism in obese, non-diabetic adults.
Mechanisms for liraglutide-induced weight loss are poorly understood.. We investigated the effects of liraglutide on gastric emptying, glycemic parameters, appetite and energy metabolism in obese non-diabetic individuals.. Participants (N=49, 18-75 years, body mass index: 30-40 kg m(-2)) were randomized to two of three treatments: liraglutide 1.8 mg, 3.0 mg, or placebo in a double-blind, incomplete crossover trial. After 5 weeks, 24-h energy expenditure (EE) and substrate oxidation were measured in a respiratory chamber. Gastric emptying (acetaminophen absorption method), glycemic parameters and appetite were assessed during a 5-h meal test. Ad libitum energy intake during a subsequent lunch was also assessed.. Five-hour gastric emptying (AUC(0-300 min)) was found to be equivalent for liraglutide 1.8 versus 3.0 mg (primary end point), and for both liraglutide doses versus placebo, as 90% confidence intervals for the estimated treatment ratios were contained within the prespecified interval (0.80-1.25). However, 1-h gastric emptying was 23% lower than placebo with liraglutide 3.0 mg (P=0.007), and a nonsignificant 13% lower than placebo with liraglutide 1.8 mg (P=0.14). Both liraglutide doses similarly reduced fasting glucose (0.5-0.6 mmol l(-1) versus placebo, P<0.0001), glucose Cmax and 1-h AUC versus placebo; only liraglutide 3.0 mg reduced iAUC(0-300 min) (by ∼26% versus placebo, P=0.02). Glucagon iAUC(0-300 min) decreased by ∼30%, and iAUC(0-60 min) for insulin and C-peptide was ∼20% lower with both liraglutide doses versus placebo. Liraglutide doses similarly increased mean postprandial satiety and fullness ratings, reduced hunger and prospective food consumption and decreased ad libitum energy intake by ∼16%. Liraglutide-associated reductions in EE were partly explained by a decrease in body weight. A relative shift toward increased fat and reduced carbohydrate oxidation was observed with liraglutide. Clinicaltrials.gov ID:NCT00978393.. Novo Nordisk.. Gastric emptying AUC(0-300 min) was equivalent for liraglutide 1.8 and 3.0 mg, and for liraglutide versus placebo, whereas reductions in 1-h gastric emptying of 23% with liraglutide 3.0 mg and 13% with 1.8 mg versus placebo were observed. Liraglutide 3.0 mg improved postprandial glycemia to a greater extent than liraglutide 1.8 mg. Liraglutide-induced weight loss appears to be mediated by reduced appetite and energy intake rather than increased EE. Topics: Adolescent; Adult; Aged; Appetite; Blood Glucose; Body Mass Index; Body Weight; Cross-Over Studies; Double-Blind Method; Energy Intake; Energy Metabolism; Female; Gastric Emptying; Glucagon-Like Peptide 1; Glycated Hemoglobin; Humans; Hypoglycemic Agents; Liraglutide; Male; Middle Aged; Obesity; Satiation; Treatment Outcome; Weight Loss | 2014 |
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 |
Pancreatic beta cell function following liraglutide-augmented weight loss in individuals with prediabetes: analysis of a randomised, placebo-controlled study.
Liraglutide can modulate insulin secretion by directly stimulating beta cells or indirectly through weight loss and enhanced insulin sensitivity. Recently, we showed that liraglutide treatment in overweight individuals with prediabetes (impaired fasting glucose and/or impaired glucose tolerance) led to greater weight loss (-7.7% vs -3.9%) and improvement in insulin resistance compared with placebo. The current study evaluates the effects on beta cell function of weight loss augmented by liraglutide compared with weight loss alone.. This was a parallel, randomised study conducted in a single academic centre. Both participants and study administrators were blinded to treatment assignment. Individuals who were 40-70 years old, overweight (BMI 27-40 kg/m(2)) and with prediabetes were randomised (via a computerised system) to receive liraglutide (n = 35) or matching placebo (n = 33), and 49 participants were analysed. All were instructed to follow an energy-restricted diet. Primary outcome was insulin secretory function, which was evaluated in response to graded infusions of glucose and day-long mixed meals.. Liraglutide treatment (n = 24) significantly (p ≤ 0.03) increased the insulin secretion rate (% mean change [95% CI]; 21% [12, 31] vs -4% [-11, 3]) and pancreatic beta cell sensitivity to intravenous glucose (229% [161, 276] vs -0.5% (-15, 14]), and decreased insulin clearance rate (-3.5% [-11, 4] vs 8.2 [0.2, 16]) as compared with placebo (n = 25). The liraglutide-treated group also had significantly (p ≤ 0.03) lower day-long glucose (-8.2% [-11, -6] vs -0.1 [-3, 2]) and NEFA concentrations (-14 [-20, -8] vs -2.1 [-10, 6]) following mixed meals, whereas day-long insulin concentrations did not significantly differ as compared with placebo. In a multivariate regression analysis, weight loss was associated with a decrease in insulin secretion rate and day-long glucose and insulin concentrations in the placebo group (p ≤ 0.05), but there was no association with weight loss in the liraglutide group. The most common side effect of liraglutide was nausea.. A direct stimulatory effect on beta cell function was the predominant change in liraglutide-augmented weight loss. These changes appear to be independent of weight loss.. ClinicalTrials.gov NCT01784965 FUNDING: The study was funded by the ADA. Topics: Adult; Aged; Blood Glucose; Diet, Reducing; Double-Blind Method; Female; Glucagon-Like Peptide 1; Humans; Hypoglycemic Agents; Insulin; Insulin Resistance; Insulin Secretion; Insulin-Secreting Cells; Liraglutide; Male; Middle Aged; Obesity; Prediabetic State; Weight Loss | 2014 |
Short-term combined treatment with liraglutide and metformin leads to significant weight loss in obese women with polycystic ovary syndrome and previous poor response to metformin.
The effect of metformin on weight reduction in polycystic ovary syndrome (PCOS) is often unsatisfactory. In this study, we investigated the potential add-on effect of treatment with the glucagon-like peptide-1 receptor agonist liraglutide on weight loss in obese nondiabetic women with PCOS who had lost <5% body weight during pretreatment with metformin.. A total of 40 obese women with PCOS, who had been pretreated with metformin for at least 6 months, participated in a 12-week open-label, prospective study. They were randomized to one of three treatment arms: metformin (MET) arm 1000 mg BID, liraglutide (LIRA) arm 1.2 mg QD s.c., or combined MET 1000 mg BID and LIRA (COMBI) 1.2 mg QD s.c. Lifestyle intervention was not actively promoted. The primary outcome was change in body weight.. Thirty six patients (aged 31.3 ± 7.1 years, BMI 37.1 ± 4.6 kg/m²) completed the study: 14 on MET, 11 on LIRA, and 11 on combined treatment. COMBI therapy was superior to LIRA and MET monotherapy in reducing weight, BMI, and waist circumference. Subjects treated with COMBI lost on average 6.5 ± 2.8 kg compared with a 3.8 ± 3.7 kg loss in the LIRA group and a 1.2 ± 1.4 kg loss in the MET group (P<0.001). The extent of weight loss was stratified: a total of 38% of subjects were high responders who lost ≥5% body weight, 22% of them in the COMBI arm compared with 16 and 0% in the LIRA and MET arm respectively. BMI decreased by 2.4 ± 1.0 in the COMBI arm compared with 1.3 ± 1.3 in LIRA and 0.5 ± 0.5 in the MET arm (P<0.001). Waist circumference also decreased by 5.5 ± 3.8 cm in the COMBI arm compared with 3.2 ± 2.9 cm in LIRA and 1.6 ± 2.9 cm in the MET arm (P=0.029). Subjects treated with liraglutide experienced more nausea than those treated with metformin, but severity of nausea decreased over time and did not correlate with weight loss.. Short-term combined treatment with liraglutide and metformin was associated with significant weight loss and decrease in waist circumference in obese women with PCOS who had previously been poor responders regarding weight reduction on metformin monotherapy. Topics: Adult; Body Weight; Female; Glucagon-Like Peptide 1; Glucagon-Like Peptide-1 Receptor; Humans; Liraglutide; Metformin; Obesity; Receptors, Glucagon; Waist Circumference; Weight Loss | 2014 |
Effects of a breakfast spread out over time on the food intake at lunch and the hormonal responses in obese men.
The effects of frequent eating on health and particularly on appetite and metabolism are unclear. We have previously shown that frequent eating decreased appetite and energy intake at the subsequent meal in lean men. In the present study, we tested the same pattern in obese subjects. Seventeen obese men participated in: (i) two sessions consisting of a breakfast consumed in one eating episode at T0 (F1), or in four isocaloric eating episodes at T0, T60, T120, and T180min (F4), followed by an ad libitum buffet (T240) in an experimental restaurant. Subjects rated their appetite throughout the sessions. (ii) two sessions consisting of the same breakfasts F1 and F4 in a Clinical Centre, followed by a standardized meal. Blood sampling was performed to study ghrelin, glucagon-like peptide-1 (GLP-1), and metabolic kinetics. Indirect calorimetry measurements were performed. After F4, at T240min, ghrelin concentration (P=0.03) and hunger ratings (P<0.001) were lower while GLP-1 concentration (P=0.006) and satiety ratings (P=0.02) were higher. In F4, subjects consumed at the buffet, less food in grams (P=0.04) and less energy from low energy dense foods (P=0.01), but total energy intakes were not different between conditions. In F4, the area under the curve was lower for insulin (P=0.02) and non-esterified fatty acids (NEFA) (P=0.03). Diet induced thermogenesis was reduced in F4 (P=0.03) between T0 and T240. Even if subjective and physiological data suggest a beneficial effect of frequent eating on appetite in obese men, no effect was demonstrated on energy intake. Moreover, the decrease in diet induced thermogenesis and lipolysis, reflected by NEFA profiles, could be deleterious on energy balance in the long run. Topics: Adult; Appetite; Breakfast; Calorimetry, Indirect; Cross-Over Studies; Eating; Energy Intake; Fatty Acids, Nonesterified; Food; Ghrelin; Glucagon-Like Peptide 1; Humans; Hunger; Insulin; Lunch; Male; Meals; Obesity; Thermogenesis; Time Factors | 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 |
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 |
The impact of oligofructose on stimulation of gut hormones, appetite regulation and adiposity.
To investigate the effect of nutrient stimulation of gut hormones by oligofructose supplementation on appetite, energy intake (EI), body weight (BW) and adiposity in overweight and obese volunteers.. In a parallel, single-blind and placebo-controlled study, 22 healthy overweight and obese volunteers were randomly allocated to receive 30 g day(-1) oligofructose or cellulose for 6 weeks following a 2-week run-in. Subjective appetite and side effect scores, breath hydrogen, serum short chain fatty acids (SCFAs), plasma gut hormones, glucose and insulin concentrations, EI, BW and adiposity were quantified at baseline and post-supplementation.. Oligofructose increased breath hydrogen (P < 0.0001), late acetate concentrations (P = 0.024), tended to increase total area under the curve (tAUC)420 mins peptide YY (PYY) (P = 0.056) and reduced tAUC450 mins hunger (P = 0.034) and motivation to eat (P = 0.013) when compared with cellulose. However, there was no significant difference between the groups in other parameters although within group analyses showed an increase in glucagon-like peptide 1 (GLP-1) (P = 0.006) in the cellulose group and a decrease in EI during ad libitum meal in both groups.. Oligofructose increased plasma PYY concentrations and suppressed appetite, while cellulose increased GLP-1 concentrations. EI decreased in both groups. However, these positive effects did not translate into changes in BW or adiposity. Topics: Adiposity; Adult; Appetite; Appetite Regulation; Area Under Curve; Blood Glucose; Body Weight; Cellulose; Dietary Fiber; Dietary Supplements; Energy Intake; Fatty Acids; Female; Glucagon-Like Peptide 1; Healthy Volunteers; Humans; Insulin; Male; Middle Aged; Obesity; Oligosaccharides; Overweight; Patient Compliance; Peptide YY; Single-Blind Method; Young Adult | 2014 |
Randomised clinical trial: The beneficial effects of VSL#3 in obese children with non-alcoholic steatohepatitis.
Gut microbiota modifiers may have beneficial effects of non-alcoholic fatty liver disease (NAFLD) but randomised controlled trials (RCT) are lacking in children.. To perform a double-blind RCT of VSL#3 vs. placebo in obese children with biopsy-proven NAFLD.. Of 48 randomised children, 44 (22 VSL#3 and 22 placebo) completed the study. The main outcome was the change in fatty liver severity at 4 months as detected by ultrasonography. Secondary outcomes were the changes in triglycerides, insulin resistance as detected by the homoeostasis model assessment (HOMA), alanine transaminase (ALT), body mass index (BMI), glucagon-like peptide 1 (GLP-1) and activated GLP-1 (aGLP-1). Ordinal and linear models with cluster confidence intervals were used to evaluate the efficacy of VSL#3 vs. placebo at 4 months.. At baseline, moderate and severe NAFLD were present in 64% and 36% of PLA children and in 55% and 45% of VSL#3 children. The probability that children supplemented with VSL#3 had none, light, moderate or severe FL at the end of the study was 21%, 70%, 9% and 0% respectively with corresponding values of 0%, 7%, 76% and 17% for the placebo group (P < 0.001). No between-group differences were detected in triglycerides, HOMA and ALT while BMI decreased and GLP-1 and aGLP1 increased in the VSL#3 group (P < 0.001 for all comparisons).. A 4-month supplement of VSL#3 significantly improves NAFLD in children. The VSL#3-dependent GLP-1 increase could be responsible for these beneficial effects. Trial identifier: NCT01650025 (www.clinicaltrial.gov). Topics: Alanine Transaminase; Biopsy; Body Mass Index; Child; Dietary Supplements; Double-Blind Method; Fatty Liver; Female; Glucagon-Like Peptide 1; Humans; Insulin Resistance; Male; Non-alcoholic Fatty Liver Disease; Obesity; Probiotics; Severity of Illness Index; Treatment Outcome; Ultrasonography | 2014 |
A dose-response strategy reveals differences between normal-weight and obese men in their metabolic and inflammatory responses to a high-fat meal.
A dose-response strategy may not only allow investigation of the impact of foods and nutrients on human health but may also reveal differences in the response of individuals to food ingestion based on their metabolic health status. In a randomized crossover study, we challenged 19 normal-weight (BMI: 20-25 kg/m(2)) and 18 obese (BMI: >30 kg/m(2)) men with 500, 1000, and 1500 kcal of a high-fat (HF) meal (60.5% energy from fat). Blood was taken at baseline and up to 6 h postprandially and analyzed for a range of metabolic, inflammatory, and hormonal variables, including plasma glucose, lipids, and C-reactive protein and serum insulin, glucagon-like peptide-1, interleukin-6 (IL-6), and endotoxin. Insulin was the only variable that could differentiate the postprandial response of normal-weight and obese participants at each of the 3 caloric doses. A significant response of the inflammatory marker IL-6 was only observed in the obese group after ingestion of the HF meal containing 1500 kcal [net incremental AUC (iAUC) = 22.9 ± 6.8 pg/mL × 6 h, P = 0.002]. Furthermore, the net iAUC for triglycerides significantly increased from the 1000 to the 1500 kcal meal in the obese group (5.0 ± 0.5 mmol/L × 6 h vs. 6.0 ± 0.5 mmol/L × 6 h; P = 0.015) but not in the normal-weight group (4.3 ± 0.5 mmol/L × 6 h vs. 4.8 ± 0.5 mmol/L × 6 h; P = 0.31). We propose that caloric dose-response studies may contribute to a better understanding of the metabolic impact of food on the human organism. This study was registered at clinicaltrials.gov as NCT01446068. Topics: Adult; Biomarkers; Blood Glucose; Body Mass Index; Body Weight; C-Reactive Protein; Cholesterol; Cross-Over Studies; Diet, High-Fat; Dietary Fats; Endotoxins; Energy Intake; Fasting; Glucagon-Like Peptide 1; Humans; Insulin; Interleukin-6; Male; Meals; Middle Aged; Obesity; Postprandial Period; Switzerland; Triglycerides; Waist Circumference | 2014 |
Obese patients have higher circulating protein levels of dipeptidyl peptidase IV.
Dipeptidyl peptidase IV (DPPIV) is a protease with broad distribution involved in various homeostatic processes such as immune defense, psychoneuroendocrine functions and nutrition. While DPPIV protein levels were investigated in patients with hyporectic disorders, less is known under conditions of obesity. Therefore, we investigated DPPIV across a broad range of body mass index (BMI). Blood samples from hospitalized patients with normal weight (BMI 18.5-25 kg/m(2)), anorexia nervosa (BMI <17.5 kg/m(2)) and obesity (BMI 30-40, 40-50 and >50 kg/m(2), n = 15/group) were tested cross-sectionally and DPPIV concentration and total enzyme activity and the DPPIV targets, pancreatic polypeptide (PP) and glucagon-like peptide (GLP-1) were measured. DPPIV protein expression was detected in human plasma indicated by a strong band at the expected size of 110 kDa and another major band at 50 kDa, likely representing a fragment comprised of two heavy chains. Obese patients had higher DPPIV protein levels compared to normal weight and anorexics (+50%, p<0.05) resulting in a positive correlation with BMI (r = 0.34, p = 0.004). DPPIV serum activity was similar in all groups (p>0.05), while the concentration/activity ratio was higher in obese patients (p<0.05). Plasma PP levels were highest in anorexic patients (∼ 2-fold increase compared to other groups, p<0.05), whereas GLP-1 did not differ among groups (p<0.05). Taken together, circulating DPPIV protein levels depend on body weight with increased levels in obese resulting in an increased concentration/activity ratio. Since DPPIV deactivates food intake-inhibitory hormones like PP, an increased DPPIV concentration/activity ratio might contribute to reduced food intake-inhibitory signaling under conditions of obesity. Topics: Anorexia Nervosa; Body Mass Index; Dipeptidyl Peptidase 4; Female; Gene Expression Regulation, Enzymologic; Glucagon-Like Peptide 1; Humans; Male; Obesity; Pancreatic Polypeptide; Signal Transduction | 2014 |
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 |
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 |
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 |
Thirty days of resveratrol supplementation does not affect postprandial incretin hormone responses, but suppresses postprandial glucagon in obese subjects.
Resveratrol, a natural polyphenolic compound produced by various plants (e.g. red grapes) and found in red wine, has glucose-lowering effects in humans and rodent models of obesity and/or diabetes. The mechanisms behind these effects have been suggested to include resveratrol-induced secretion of the gut incretin hormone glucagon-like peptide-1. We investigated postprandial incretin hormone and glucagon responses in obese human subjects before and after 30 days of resveratrol supplementation.. Postprandial plasma responses of the incretin hormones glucagon-like peptide-1 and glucose-dependent insulinotropic polypeptide and glucagon were evaluated in 10 obese men [subjects characteristics (mean ± standard error of the mean): age 52 ± 2 years; BMI 32 ± 1 kg/m(2), fasting plasma glucose 5.5 ± 0.1 mmol/l] who had been given a dietary supplement of resveratrol (Resvida(®) 150 mg/day) or placebo for 30 days in a randomized, double-blind, crossover design with a 4-week washout period. At the end of each intervention period a standardized meal test (without co-administration of resveratrol) was performed.. Resveratrol supplementation had no impact on fasting plasma concentrations or postprandial plasma responses (area under curve values) of glucose-dependent insulinotropic polypeptide (11.2 ± 2.1 vs. 11.8 ± 2.2 pmol/l, P = 0.87; 17.0 ± 2.2 vs. 14.8 ± 1.6 min × nmol/l, P = 0.20) or glucagon-like peptide-1 (15.4 ± 1.0 vs. 15.2 ± 0.9 pmol/l, P = 0.84; 5.6 ± 0.4 vs. 5.7 ± 0.3 min × nmol/l, P = 0.73). Resveratrol supplementation significantly suppressed postprandial glucagon responses (4.4 ± 0.4 vs. 3.9 ± 0.4 min × nmol/l, P = 0.01) without affecting fasting glucagon levels (15.2 ± 2.2 vs. 14.5 ± 1.5 pmol/l, P = 0.56).. Our data suggest that 30 days of resveratrol supplementation does not affect fasting or postprandial incretin hormone plasma levels in obese humans, but suppresses postprandial glucagon responses. Topics: Antioxidants; Blood Glucose; Cross-Over Studies; Dietary Supplements; Double-Blind Method; Fasting; Gastric Inhibitory Polypeptide; Glucagon; Glucagon-Like Peptide 1; Humans; Incretins; Male; Middle Aged; Obesity; Postprandial Period; Resveratrol; Stilbenes; Time Factors; Treatment Outcome | 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 |
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 |
A new endoscopically implantable device (SatiSphere) for treatment of obesity--efficacy, safety, and metabolic effects on glucose, insulin, and GLP-1 levels.
The endoluminal mechanical device SatiSphere is a new endoscopically implantable device designed to delay transit time of nutrients through the duodenum. It consists of a 1-mm nitinol wire with pigtail ends and several mesh spheres mounted along its course, released in the duodenum and gastric antrum to conform to the duodenal C loop configuration and thereby self-anchor.. The objective is to test the safety, efficacy, and effect on body weight in a 2:1 randomized study, as well as incretin secretion in a subgroup.. Of 31 included cases (11 men, mean age 42.9 years, mean BMI 41.3 kg/m2), 21 patients treated with endoscopic device insertion with scheduled device removal after 3 months were compared with 10 controls. In 10 of 21 patients, device migration occurred, in two cases necessitating emergency surgery, which led to termination of the trial. Weight loss after 3 months was 6.7, 4.6, and 2.2 kg in the groups completing therapy, all treatment cases using intention to treat (ITT) analysis and controls. Excess weight loss was significantly increased by endoluminal mechanical device insertion (18.4, 12.2, and 4.4% in completers, ITT analysis group and controls; p = 0.02 for completers vs. controls). Measuring glucose, insulin, and glucagon-like peptide 1 (GLP-1) following a mixed-meal test with the device in place and after removal (n = 7), the device delayed glucose absorption and insulin secretion and altered kinetics in GLP-1 levels.. The device might be short-term effective in reducing body weight, which might be mediated through alterations in incretin metabolism. However, frequent device migration necessitates device modifications. Topics: Adult; Blood Glucose; Device Removal; Duodenum; Eating; Endoscopy, Gastrointestinal; Equipment Design; Feasibility Studies; Female; Foreign-Body Migration; Glucagon-Like Peptide 1; Humans; Incretins; Insulin; Intestinal Absorption; Male; Middle Aged; Obesity; Postoperative Complications; Treatment Outcome; Weight Loss | 2013 |
Weight maintenance and additional weight loss with liraglutide after low-calorie-diet-induced weight loss: the SCALE Maintenance randomized study.
Liraglutide, a once-daily human glucagon-like peptide-1 analog, induced clinically meaningful weight loss in a phase 2 study in obese individuals without diabetes. The present randomized phase 3 trial assessed the efficacy of liraglutide in maintaining weight loss achieved with a low-calorie diet (LCD).. Obese/overweight participants (≥18 years, body mass index ≥30 kg m(-2) or ≥27 kg m(-2) with comorbidities) who lost ≥5% of initial weight during a LCD run-in were randomly assigned to liraglutide 3.0 mg per day or placebo (subcutaneous administration) for 56 weeks. Diet and exercise counseling were provided throughout the trial. Co-primary end points were percentage weight change from randomization, the proportion of participants that maintained the initial ≥5% weight loss, and the proportion that lost ≥5% of randomization weight (intention-to-treat analysis). ClinicalTrials.gov identifier: NCT00781937.. Participants (n=422) lost a mean 6.0% (s.d. 0.9) of screening weight during run-in. From randomization to week 56, weight decreased an additional mean 6.2% (s.d. 7.3) with liraglutide and 0.2% (s.d. 7.0) with placebo (estimated difference -6.1% (95% class intervals -7.5 to -4.6), P<0.0001). More participants receiving liraglutide (81.4%) maintained the ≥5% run-in weight loss, compared with those receiving placebo (48.9%) (estimated odds ratio 4.8 (3.0; 7.7), P<0.0001), and 50.5% versus 21.8% of participants lost ≥5% of randomization weight (estimated odds ratio 3.9 (2.4; 6.1), P<0.0001). Liraglutide produced small but statistically significant improvements in several cardiometabolic risk factors compared with placebo. Gastrointestinal (GI) disorders were reported more frequently with liraglutide than placebo, but most events were transient, and mild or moderate in severity.. Liraglutide, with diet and exercise, maintained weight loss achieved by caloric restriction and induced further weight loss over 56 weeks. Improvements in some cardiovascular disease-risk factors were also observed. Liraglutide, prescribed as 3.0 mg per day, holds promise for improving the maintenance of lost weight. Topics: Adolescent; Adult; Aged; Aged, 80 and over; Anti-Obesity Agents; Caloric Restriction; Canada; Double-Blind Method; Drug Administration Schedule; Exercise Therapy; Female; Glucagon-Like Peptide 1; Humans; Liraglutide; Male; Middle Aged; Obesity; Treatment Outcome; United States; Weight Loss | 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 |
Long-term inhibition of intestinal lipase by orlistat improves release of gut hormones increasing satiety in obese women.
Reduced postprandial secretion of peptide YY (PYY), glucagon-like peptide-1 (GLP-1), cholecystokinin, and increased hunger was reported after a single dose of orlistat, an inhibitor of intestinal lipase. As yet, the influence of long-term therapy with orlistat on PYYand GLP-1 release has not been studied. Our study was aimed at assessing the influence of 8-week therapy with orlistat as a component of a weight loss program on pre-prandial circulating PYY and GLP-1 levels.. Forty obese women, without concomitant diseases, were randomly allocated to groups receiving orlistat or placebo during an 8-week weight management program. Body mass, body composition and plasma levels of PYY, GLP-1 and insulin (for QUICKI calculation) were determined prior to and at the end of therapy.. Women treated with orlistat obtained significantly greater body and fat mass loss than those receiving placebo (9.0 ± 3.1 vs. 5.9 ± 3.2% and 21.9 ± 10.9 vs. 7.4 ± 15.6%, respectively). Only in those treated with orlistat a slight, but significant increase of the QUICKI was found (8.0 ± 16.5 vs. -0.1 ± 12.7 %, respectively). Weight loss was followed by a significant increase of plasma levels of PYY and GLP-1 in group treated with orlistat, and was about 2-times greater than receiving placebo. The increase was independent of body mass changes.. The long-term inhibition of intestinal lipase by orlistat increases the pre-prandial levels of GLP-1 and PYY, independent of body mass changes. Therefore, it seems that long-term treatment with orlistat may exert hunger suppressing and insulin sensitizing incretin effect beyond weight reduction. Topics: Body Mass Index; Body Weight; Double-Blind Method; Female; Glucagon-Like Peptide 1; Humans; Insulin; Intestinal Mucosa; Intestines; Lactones; Lipase; Obesity; Orlistat; Peptide YY; Weight Loss | 2013 |
Acute effect on satiety, resting energy expenditure, respiratory quotient, glucagon-like peptide-1, free fatty acids, and glycerol following consumption of a combination of bioactive food ingredients in overweight subjects.
A combination of bioactive food ingredients (capsaicinoids, epigallocatechin gallate, piperin, and l-carnitine, CBFI) may promote satiety and thermogenesis. The study was conducted in order to assess whether there is any effect on satiety, resting energy expenditure (REE), respiratory quotient, glucagon-like peptide-1 (GLP-1), free fatty acids (FFA) and glycerol release, following a standardized mixed meal with or without single consumption of a CBFI.. An 8-week randomized double-blind placebo-controlled trial.. Dietetic and Metabolic Unit, Azienda di Servizi alla Persona, University of Pavia and "Villa delle Querce" Clinical Rehabilitation Institute, Rome, Italy.. Thirty-seven overweight adults (body mass index [BMI]: 25-35).. Nineteen overweight subjects were included in the supplemented group (14 women, 5 men; age 46.4 ± 6.4; BMI: 30.5 ± 3.3) and 18 in the placebo group (13 women, 5 men; age 40.8 ± 11.5; BMI: 30.1 ± 2.6). Satiety was assessed using 100-mm visual analogue scales (VAS) and the area under the curve was calculated.. All measured parameters increased significantly in comparison with baseline in response to meal, both with CBFI and with placebo. However, throughout the study day, the supplemented group experienced a significantly greater increase than the placebo group in their sensation of satiety following acute administration of the supplement.. CBFI may therefore be of great value in the treatment of overweight patients by increasing satiety and stimulating thermogenesis. Topics: Adult; Alkaloids; Area Under Curve; Basal Metabolism; Benzodioxoles; Capsaicin; Carnitine; Catechin; Dietary Supplements; Double-Blind Method; Fatty Acids, Nonesterified; Female; Glucagon-Like Peptide 1; Glycerol; Humans; Male; Middle Aged; Obesity; Phytotherapy; Piperidines; Plant Extracts; Polyunsaturated Alkamides; Satiation; Satiety Response | 2013 |
Effect of low- and high-glycemic load on circulating incretins in a randomized clinical trial.
Low-glycemic load diets lower post-prandial glucose and insulin responses; however, the effect of glycemic load on circulating incretin concentrations is unclear. We aimed to assess effects of dietary glycemic load on fasting and post-prandial glucose, insulin and incretin (i.e., glucose-dependent insulinotropic polypeptide (GIP) and glucagon-like peptide-1 (GLP-1)) concentrations and to examine for effect modification by adiposity.. We conducted a single-center, randomized controlled crossover feeding trial in which a subset of participants had post-prandial testing. Participants were recruited from the local Seattle area. We enrolled 89 overweight-obese (BMI 28.0-39.9 kg/m(2)) and lean (BMI 18.5-25.0 kg/m(2)) healthy adults. Participants consumed two 28-day, weight-maintaining high- and low-glycemic load controlled diets in random order. Primary outcome measures were post-prandial circulating concentrations of glucose, insulin, GIP and GLP-1, following a test breakfast.. Of the 80 participants completing both diet interventions, 16 had incretin testing and comprise the group for analyses. Following each 28-day high- and low-glycemic load diet, mean fasting concentrations of insulin, glucose, GIP and GLP-1 were not significantly different. Mean integrated post-prandial concentrations of glucose, insulin and GIP were higher (1504±476 mg/dL/min, p<0.01; 2012±644 μU/mL/min, p<0.01 and 15517±4062 pg/mL/min, p<0.01, respectively) and GLP-1 was lower (-81.6±38.5 pmol/L/min, p<0.03) following the high-glycemic load breakfast as compared to the low-glycemic load breakfast. Body fat did not significantly modify the effect of glycemic load on metabolic outcomes.. High-glycemic load diets in weight-maintained healthy individuals lead to higher post-prandial GIP and lower post-prandial GLP-1 concentrations. Future studies evaluating dietary glycemic load manipulation of incretin effects would be helpful for establishing diabetes nutrition guidelines. Topics: Adiposity; Adult; Blood Glucose; Breakfast; Cross-Over Studies; Diet; Female; Gastric Inhibitory Polypeptide; Glucagon-Like Peptide 1; Humans; Insulin; Male; Obesity; Postprandial Period; 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 |
Safety, tolerability and sustained weight loss over 2 years with the once-daily human GLP-1 analog, liraglutide.
Having demonstrated short-term weight loss with liraglutide in this group of obese adults, we now evaluate safety/tolerability (primary outcome) and long-term efficacy for sustaining weight loss (secondary outcome) over 2 years.. A randomized, double-blind, placebo-controlled 20-week study with 2-year extension (sponsor unblinded at 20 weeks, participants/investigators at 1 year) in 19 European clinical research centers.. A total of 564 adults (n=90-98 per group; body mass index 30-40 kg m(-2)) enrolled, 398 entered the extension and 268 completed the 2-year trial. Participants received diet (500 kcal deficit per day) and exercise counseling during 2-week run-in, before being randomly assigned (with a telephone or web-based system) to once-daily subcutaneous liraglutide (1.2, 1.8, 2.4 or 3.0 mg, n=90-95), placebo (n=98) or open-label orlistat (120 mg × 3, n=95). After 1 year, liraglutide/placebo recipients switched to liraglutide 2.4 mg, then 3.0 mg (based on 20-week and 1-year results, respectively). The trial ran from January 2007-April 2009 and is registered with Clinicaltrials.gov, number NCT00480909.. From randomization to year 1, liraglutide 3.0 mg recipients lost 5.8 kg (95% confidence interval 3.7-8.0) more weight than those on placebo and 3.8 kg (1.6-6.0) more than those on orlistat (P0.0001; intention-to-treat, last-observation-carried-forward). At year 2, participants on liraglutide 2.4/3.0 mg for the full 2 years (pooled group, n=184) lost 3.0 kg (1.3-4.7) more weight than those on orlistat (n=95; P<0.001). Completers on liraglutide 2.4/3.0 mg (n=92) maintained a 2-year weight loss of 7.8 kg from screening. With liraglutide 3.0 mg, 20-week body fat decreased by 15.4% and lean tissue by 2.0%. The most frequent drug-related side effects were mild to moderate, transient nausea and vomiting. With liraglutide 2.4/3.0 mg, the 2-year prevalence of prediabetes and metabolic syndrome decreased by 52 and 59%, with improvements in blood pressure and lipids.. Liraglutide is well tolerated, sustains weight loss over 2 years and improves cardiovascular risk factors. Topics: Adolescent; Adult; Aged; Analysis of Variance; Anti-Obesity Agents; Double-Blind Method; Drug Administration Schedule; Europe; Exercise Therapy; Female; Glucagon-Like Peptide 1; Humans; Liraglutide; Male; Middle Aged; Obesity; Prediabetic State; Risk Reduction Behavior; Treatment Outcome; Weight Loss; Young Adult | 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 |
Satiety scores and satiety hormone response after sucrose-sweetened soft drink compared with isocaloric semi-skimmed milk and with non-caloric soft drink: a controlled trial.
Observational studies indicate that sugar-sweetened soft drinks (SSSD) may promote obesity, among other factors, owing to low-satiating effects. The effect of energy in drinks on appetite is still unclear. We examined the effect of two isocaloric, but macronutrient, different beverages (SSSD versus semi-skimmed milk) and two non-energy-containing beverages (aspartame-sweetened soft drink (ASSD) and water) on appetite, appetite-regulating hormones and energy intake (EI).. In all, 24 obese individuals were included in a crossover trial. Each subject was served either 500 ml of SSSD (regular cola: 900 kJ), semi-skimmed milk (950 kJ), ASSD (diet cola: 7.5 kJ), or water. Subjective appetite scores, ghrelin, GLP-1, and GIP concentrations were measured at baseline and continuously 4-h post intake. Ad libitum EI was measured 4 h after intake of the test drinks.. Milk induced greater subjective fullness and less hunger than regular cola (P<0.05). Also, milk led to 31% higher GLP-1 (95% CI: 20, 44; P<0.01) and 45% higher GIP (95% CI: 23, 72; P<0.01) concentrations compared with SSSD. Ghrelin was equally 20% lower after milk and SSSD compared with water. The total EI (ad libitum EI+EI from the drink) was higher after the energy-containing drinks compared with diet cola and water (P<0.01).. Milk increased appetite scores and GLP-1 and GIP responses compared with SSSD. The energy containing beverages were not compensated by decreased EI at the following meal, emphasizing the risk of generating a positive energy balance by consuming energy containing beverages. Furthermore, there were no indications of ASSD increased appetite or EI compared with water. Topics: Adult; Animals; Appetite; Aspartame; Carbonated Beverages; Cross-Over Studies; Energy Intake; Female; Ghrelin; Glucagon-Like Peptide 1; Hormones; Humans; Hunger; Male; Milk; Obesity; Satiation; Satiety Response; Sucrose; Sweetening Agents; Young Adult | 2012 |
Anorexigenic effects of miglitol in concert with the alterations of gut hormone secretion and gastric emptying in healthy subjects.
Although the α-glucosidase inhibitor miglitol (MG) has been reported to have anorexigenic effects, the mechanism remains to be elucidated. The objective of this study was to explore the effects of MG on appetite in relation to concomitant changes in postprandial gut hormone levels. This randomized open-label crossover study included 20 healthy volunteers. The effects of 50 mg MG on glucagon-like peptide-1 (GLP-1), peptide YY (PYY), and ghrelin levels were assessed in conjunction with a simultaneous determination of appetite scores using visual analogue scales (VAS) over 3 h after the ingestion of a 592 kcal test cookie. Additionally, the gastric emptying rate (GER) was measured using breath ¹³CO₂ appearance in 10 subjects. 12 subjects were administered 50 mg MG thrice a day for 1 week, and alterations of the gut hormone levels and the VAS scores for appetite were evaluated. MG pre-administration resulted in a significant enhancement of GLP-1 and PYY responses induced by the cookie ingestion. Following MG administration, ghrelin level declined at 1 h, with a persistent suppression during the postprandial phase in contrast to the restoration to the basal level without MG. Furthermore, MG pre-administration suppressed appetite and maintained satiety evaluated using a VAS rating with concomitant inhibition of GER after cookie ingestion. One-week administration of MG did not influence either gut hormone levels before a meal or VAS rating during a whole day. These observations suggest that MG exerts an anorexigenic effects with concomitant alterations of gut hormone secretions and gastric emptying after meal ingestion. Topics: 1-Deoxynojirimycin; Adult; Appetite; Appetite Depressants; Female; Gastric Emptying; Ghrelin; Glucagon-Like Peptide 1; Humans; Male; Obesity; Peptide YY; Young Adult | 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 |
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 |
The effect of a very low calorie diet on insulin sensitivity, beta cell function, insulin clearance, incretin hormone secretion, androgen levels and body composition in obese young women.
Evaluation of the effect of an 8-week very low calorie diet (VLCD, 500-600 kcal daily) on weight, body fat distribution, glucose, insulin and lipid metabolism, androgen levels and incretin secretion in obese women.. Seventeen overweight women (BMI > 28) were recruited to the study. Glucose, insulin and lipid metabolism were evaluated by euglycemic clamp technique, indirect calorimetry and an oral glucose tolerance test (OGTT). Insulin sensitivity was calculated as glucose disposal rate (GDR) and insulin sensitivity index (ISI), and also by HOMA-IR. Insulin secretion rate (ISR) was calculated from plasma C-peptide measurements. Secretion of glucagon-like peptide-1 (GLP-1) and glucose-dependent insulinotropic peptide (GIP) was measured during an oral glucose tolerance test. Abdominal fat distribution was assessed by dual x-ray absorptiometry scan and computed tomography.. Ten women completed the intervention. The subjects lost an average 11% of their baseline weight. There was a significant loss of subcutaneous abdominal fatty tissue (p < 0.01) and intra-abdominal fatty tissue (p =0.05). Whole body (HOMA-IR) (p < 0.05) insulin sensitivity increased significantly, but peripheral (ISI) insulin sensitivity was unaltered after weight loss. GIP increased (p < 0.05) and GLP-1 was unaltered after the dietary intervention. Insulin responses did not differ before and after dietary intervention, however, a significant increase in insulin clearance (p < 0.05) was observed. The weight loss resulted in a significant decrease in free testosterone.. A VLCD is an effective weight loss treatment, which results in an immediate improvement in several metabolic parameters. Topics: Adult; Androgens; Body Composition; Body Weight; Caloric Restriction; Dihydrotestosterone; Female; Glucagon-Like Peptide 1; Glucose Tolerance Test; Humans; Incretins; Insulin; Insulin Resistance; Insulin Secretion; Insulin-Secreting Cells; Intra-Abdominal Fat; Lipid Mobilization; Obesity; Testosterone; Treatment Outcome; Young Adult | 2012 |
Alterations in energy balance following exenatide administration.
Exenatide is a medication similar in structure and effect to native glucagon-like peptide-1, an incretin hormone with glucose-lowering properties. The aim of the study was to measure the change in total energy expenditure (TEE) and body composition during exenatide administration and by deduction the relative contributions of energy expenditure and energy intake to exenatide-induced weight loss. Forty-five obese (body mass index, 30-40 kg·m⁻²) subjects were identified. After exclusion criteria application, 28 subjects entered into the study and 18 subjects (12 female, 6 male) completed the study, which consisted of 6 visits over 14 weeks and injection of exenatide for an average of 84 ± 5 days. Respiratory gas analysis and doubly labeled water measurements were performed before initiation of exenatide and after approximately 3 months of exenatide administration. The average weight loss from the beginning of injection period to the end of the study in completed subjects was 2.0 ± 2.8 kg (p = 0.01). Fat mass declined by 1.3 ± 1.8 kg (p = 0.01) while the fat-free mass trended downward but was not significant (0.8 ± 2.2 kg, p = 0.14). There was no change in weight-adjusted TEE (p = 0.20), resting metabolic rate (p = 0.51), or physical activity energy expenditure (p = 0.38) and no change in the unadjusted thermic effect of a meal (p = 0.37). The significant weight loss because of exenatide administration was thus the result of decreasing energy intake. In obese nondiabetic subjects, exenatide administration did not increase TEE and by deduction the significant weight loss and loss of fat mass was due to decreased energy intake. Topics: Adipose Tissue; Adult; Algorithms; Anti-Obesity Agents; Body Composition; Body Mass Index; Energy Intake; Energy Metabolism; Exenatide; Female; Glucagon-Like Peptide 1; Humans; Hypoglycemic Agents; Male; Middle Aged; Obesity; Patient Dropouts; Peptides; Venoms; Weight Loss | 2012 |
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 |
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 |
Effects of sleeve gastrectomy and medical treatment for obesity on glucagon-like peptide 1 levels and glucose homeostasis in non-diabetic subjects.
The effects of medical and surgical treatments for obesity on glucose metabolism and glucagon-like peptide 1 (GLP-1) levels independent of weight loss remain unclear. This study aims to assess plasma glucose levels, insulin sensitivity and secretion, and GLP-1 levels before and after sleeve gastrectomy (SG) or medical treatment (MED) for obesity.. This study is a prospective, controlled, non-randomised study. Two groups of non-diabetic obese patients with similar BMIs, including a SG group (BMI, 35.5 ± 0.9 kg/m(2); n = 6) and a MED group (BMI, 37.7 ± 1.9 kg/m(2); n = 6) and a group of lean subjects (BMI, 21.7 ± 0.7 kg/m(2); n = 8).. Plasma glucose, insulin, and total GLP-1 levels at fasting and after the intake of a standard liquid meal at baseline and at 2 months post-intervention. At baseline, total GLP-1 levels were similar, but obese patients had lower insulin sensitivity and higher insulin secretion than lean subjects. At 2 months post-intervention, SG and MED patients achieved similar weight loss (14.4 ± 0.8%, 15.3 ± 0.9%, respectively). Insulin sensitivity increased in SG and MED patients; however, postprandial insulin secretion decreased after MED, but not after SG. The incremental area under the curve of GLP-1 increased after SG (P = 0.04), but not after MED.. Weight loss by medical or surgical treatment improved insulin sensitivity. However, only MED corrected the hyperinsulinemic postprandial state associated to obesity. Postprandial GLP-1 levels increased significantly after SG without duodenal exclusion, which may explain why insulin secretion did not decrease following this surgery. Topics: Adult; Blood Glucose; Diet, Reducing; Exercise Therapy; Female; Gastrectomy; Glucagon-Like Peptide 1; Humans; Insulin; Insulin Resistance; Male; Obesity; Prospective Studies; Treatment Outcome; Weight Loss | 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 |
Gastric bypass reduces fat intake and preference.
Roux-en-Y gastric bypass is the most effective therapy for morbid obesity. This study investigated how gastric bypass affects intake of and preference for high-fat food in an experimental (rat) study and within a trial setting (human). Proportion of dietary fat in gastric bypass patients was significantly lower 6 yr after surgery compared with patients after vertical-banded gastroplasty (P = 0.046). Gastric bypass reduced total fat and caloric intake (P < 0.001) and increased standard low-fat chow consumption compared with sham controls (P < 0.001) in rats. Compared with sham-operated rats, gastric bypass rats displayed much lower preferences for Intralipid concentrations > 0.5% in an ascending concentration series (0.005%, 0.01%, 0.05%, 0.1%, 0.5%, 1%, 5%) of two-bottle preference tests (P = 0.005). This effect was demonstrated 10 and 200 days after surgery. However, there was no difference in appetitive or consummatory behavior in the brief access test between the two groups (P = 0.71) using similar Intralipid concentrations (0.005% through 5%). Levels of glucagon-like peptide-1 (GLP-1) were increased after gastric bypass as expected. An oral gavage of 1 ml corn oil after saccharin ingestion in gastric bypass rats induced a conditioned taste aversion. These findings suggest that changes in fat preference may contribute to long-term maintained weight loss after gastric bypass. Postingestive effects of high-fat nutrients resulting in conditioned taste aversion may partially explain this observation; the role of GLP-1 in mediating postprandial responses after gastric bypass requires further investigation. Topics: Animals; Dietary Fats; Eating; Energy Intake; Female; Food Preferences; Gastric Bypass; Gastroplasty; Glucagon-Like Peptide 1; Humans; Male; Models, Animal; Obesity; Rats; Rats, Wistar; Saccharin; Taste; Time Factors | 2011 |
Improvement in chewing activity reduces energy intake in one meal and modulates plasma gut hormone concentrations in obese and lean young Chinese men.
Mastication is the first step in ingesting food, but the effects of mastication on energy intake and gut hormones in both obese and lean subjects have not been extensively evaluated.. The current study aimed to compare the differences in chewing activities between obese and lean subjects and to examine the effects of chewing on energy intake and gut hormone concentrations in both obese and lean subjects.. Sixteen lean and 14 obese young men participated in the current research. In study 1, we investigated whether the chewing factors of obese subjects were different from those of lean subjects. In study 2, we explored the effects of chewing on energy intake. A test meal consisting of 2200 kJ (68% of energy as carbohydrate, 21% of energy as fat, and 11% of energy as protein) was then consumed on 2 different sessions (15 chews and 40 chews per bite of 10 g of food) by each subject to assess the effects of chewing on plasma gut hormone concentrations.. Compared with lean participants, obese participants had a higher ingestion rate and a lower number of chews per 1 g of food. However, obese participants had a bite size similar to that of lean subjects. Regardless of status, the subjects ingested 11.9% less after 40 chews than after 15 chews. Compared with 15 chews, 40 chews resulted in lower energy intake and postprandial ghrelin concentration and higher postprandial glucagon-like peptide 1 and cholecystokinin concentrations in both lean and obese subjects.. Interventions aimed at improving chewing activity could become a useful tool for combating obesity. This trial was registered at chictr.org as ChiCTR-OCC-10001181. Topics: Adult; Asian People; Cholecystokinin; Energy Intake; Ghrelin; Glucagon-Like Peptide 1; Humans; Male; Mastication; Obesity; Postprandial Period; Thinness; Young Adult | 2011 |
Alterations of sucrose preference after Roux-en-Y gastric bypass.
Roux-en-Y gastric bypass (gastric bypass) patients reportedly have changes in perception and consumption of sweet-tasting foods. This study aimed to further investigate alterations in sweet food intake in rats and sucrose detection in humans after gastric bypass. Wistar rats were randomized to gastric bypass or sham-operations and preference for sucrose (sweet), sodium chloride (salty), citric acid (sour) and quinine hydrochloride (bitter) was assessed with standard two-bottle intake tests (vs. water). Intestinal T1R2 and T1R3 expression and plasma levels of glucagon-like-peptide 1 (GLP-1) and peptide YY (PYY) were measured. Furthermore, obese patients and normal weight controls were tested for sucrose taste detection thresholds pre- and postoperatively. Visual analogue scales measuring hedonic perception were used to determine the sucrose concentration considered by patients and controls as "just about right" pre- and postoperatively. Gastric bypass reduced the sucrose intake relative to water in rats (p<0.001). Preoperative sucrose exposure reduced this effect. Preference or aversion for compounds representative of other taste qualities in naïve rats remained unaffected. Intestinal T1R2 and T1R3 expression was significantly decreased in the alimentary limb while plasma levels of GLP-1 and PYY were elevated after bypass in rats (p=0.01). Bypass patients showed increased taste sensitivity to low sucrose concentrations compared with controls (p<0.05), but both groups considered the same sucrose concentration as "just about right" postoperatively. In conclusion, gastric bypass reduces sucrose intake relative to water in sucrose-naïve rats, but preoperative sucrose experience attenuates this effect. Changes in sucrose taste detection do not predict hedonic taste ratings of sucrose in bypass patients which remain unchanged. Thus, factors other than the unconditional affective value of the taste may also play a role in determining food preferences after gastric bypass. Topics: Analysis of Variance; Animals; Body Weight; Choice Behavior; Dose-Response Relationship, Drug; Drinking; Eating; Energy Intake; Female; Food Preferences; Gastric Bypass; Gene Expression Regulation; Glucagon-Like Peptide 1; Humans; Intestine, Small; Male; Obesity; Pain Measurement; Peptide YY; Rats; Rats, Wistar; Receptors, G-Protein-Coupled; RNA, Messenger; Sucrose; Sweetening Agents; Taste; Taste Threshold; Time Factors | 2011 |
Intraduodenal administration of intact pea protein effectively reduces food intake in both lean and obese male subjects.
Human duodenal mucosa secretes increased levels of satiety signals upon exposure to intact protein. However, after oral protein ingestion, gastric digestion leaves little intact proteins to enter the duodenum. This study investigated whether bypassing the stomach, through intraduodenal administration, affects hormone release and food-intake to a larger extent than orally administered protein in both lean and obese subjects.. Ten lean (BMI:23.0±0.7 kg/m²) and ten obese (BMI:33.4±1.4 kg/m²) healthy male subjects were included. All subjects randomly received either pea protein solutions (250 mg/kg bodyweight in 0.4 ml/kg bodyweight of water) or placebo (0.4 ml/kg bodyweight of water), either orally or intraduodenally via a naso-duodenal tube. Appetite-profile, plasma GLP-1, CCK, and PYY concentrations were determined over a 2 h period. After 2 h, subjects received an ad-libitum meal and food-intake was recorded.. CCK levels were increased at 10(p<0.02) and 20(p<0.01) minutes after intraduodenal protein administration (IPA), in obese subjects, compared to lean subjects, but also compared to oral protein administration (OPA)(p<0.04). GLP-1 levels increased after IPA in obese subjects after 90(p<0.02) to 120(p<0.01) minutes, compared to OPA. Food-intake was reduced after IPA both in lean and obese subjects (-168.9±40 kcal (p<0.01) and -298.2±44 kcal (p<0.01), respectively), compared to placebo. Also, in obese subjects, food-intake was decreased after IPA (-132.6±42 kcal; p<0.01), compared to OPA.. Prevention of gastric proteolysis through bypassing the stomach effectively reduces food intake, and seems to affect obese subjects to a greater extent than lean subjects. Enteric coating of intact protein supplements may provide an effective dietary strategy in the prevention/treatment of obesity. Topics: Cholecystokinin; Eating; Ghrelin; Glucagon-Like Peptide 1; Humans; Male; Obesity; Peptide YY; Pisum sativum; Plant Proteins; Thinness | 2011 |
The gut hormones PYY 3-36 and GLP-1 7-36 amide reduce food intake and modulate brain activity in appetite centers in humans.
Obesity is a major public health issue worldwide. Understanding how the brain controls appetite offers promising inroads toward new therapies for obesity. Peptide YY (PYY) and glucagon-like peptide 1 (GLP-1) are coreleased postprandially and reduce appetite and inhibit food intake when administered to humans. However, the effects of GLP-1 and the ways in which PYY and GLP-1 act together to modulate brain activity in humans are unknown. Here, we have used functional MRI to determine these effects in healthy, normal-weight human subjects and compared them to those seen physiologically following a meal. We provide a demonstration that the combined administration of PYY(3-36) and GLP-1(7-36 amide) to fasted human subjects leads to similar reductions in subsequent energy intake and brain activity, as observed physiologically following feeding. Topics: Adult; Appetite; Body Weight; Brain; Eating; Energy Intake; Fasting; Female; Glucagon-Like Peptide 1; Humans; Immunoassay; Infusions, Intravenous; Magnetic Resonance Imaging; Male; Obesity; Peptide Fragments; Peptide YY; Postprandial Period; Single-Blind Method | 2011 |
Long-term persistence of hormonal adaptations to weight loss.
After weight loss, changes in the circulating levels of several peripheral hormones involved in the homeostatic regulation of body weight occur. Whether these changes are transient or persist over time may be important for an understanding of the reasons behind the high rate of weight regain after diet-induced weight loss.. We enrolled 50 overweight or obese patients without diabetes in a 10-week weight-loss program for which a very-low-energy diet was prescribed. At baseline (before weight loss), at 10 weeks (after program completion), and at 62 weeks, we examined circulating levels of leptin, ghrelin, peptide YY, gastric inhibitory polypeptide, glucagon-like peptide 1, amylin, pancreatic polypeptide, cholecystokinin, and insulin and subjective ratings of appetite.. Weight loss (mean [±SE], 13.5±0.5 kg) led to significant reductions in levels of leptin, peptide YY, cholecystokinin, insulin (P<0.001 for all comparisons), and amylin (P=0.002) and to increases in levels of ghrelin (P<0.001), gastric inhibitory polypeptide (P=0.004), and pancreatic polypeptide (P=0.008). There was also a significant increase in subjective appetite (P<0.001). One year after the initial weight loss, there were still significant differences from baseline in the mean levels of leptin (P<0.001), peptide YY (P<0.001), cholecystokinin (P=0.04), insulin (P=0.01), ghrelin (P<0.001), gastric inhibitory polypeptide (P<0.001), and pancreatic polypeptide (P=0.002), as well as hunger (P<0.001).. One year after initial weight reduction, levels of the circulating mediators of appetite that encourage weight regain after diet-induced weight loss do not revert to the levels recorded before weight loss. Long-term strategies to counteract this change may be needed to prevent obesity relapse. (Funded by the National Health and Medical Research Council and others; ClinicalTrials.gov number, NCT00870259.). Topics: Body Mass Index; Body Weight; Cholecystokinin; Diet, Reducing; Female; Gastrointestinal Hormones; Ghrelin; Glucagon-Like Peptide 1; Humans; Intention to Treat Analysis; Leptin; Male; Middle Aged; Obesity; Peptide YY; Peptides; Postmenopause; Weight Loss | 2011 |
Effect of rimonabant and metformin on glucose-dependent insulinotropic polypeptide and glucagon-like peptide-1 in obese women with polycystic ovary syndrome.
Topics: Drug Therapy, Combination; Female; Gastric Inhibitory Polypeptide; Glucagon-Like Peptide 1; Humans; Hypoglycemic Agents; Metformin; Obesity; Piperidines; Polycystic Ovary Syndrome; Pyrazoles; Rimonabant | 2010 |
A high-fat vs. a moderate-fat meal in obese boys: nutrient balance, appetite, and gastrointestinal hormone changes.
Meal composition is a contributing factor to fat gain. In this study, we investigated the relationship between postprandial nutrient balance, satiety, and hormone changes induced by a high-fat meal vs. a moderate-fat meal. Ten prepubertal obese boys (BMI z-score range: 1.3-3.0) were recruited. Two meals (energy: 590 kcal) were compared: (i) high-fat (HF) meal: 12% protein, 52% fat, 36% carbohydrates; (ii) moderate-fat (MF) meal: 12% protein, 27% fat, 61% carbohydrates. Pre- and postprandial (5 h) substrate oxidation (indirect calorimetry), appetite (visual analogue scale), biochemical parameters and gastrointestinal hormone concentrations were measured. Carbohydrate balance was significantly (P < 0.001) lower (31.3 (5.7) g/5 h vs. 66.9 (5.9) g/5 h) and fat balance was significantly (P < 0.001) higher (11.5 (3.3) g/5 h vs. -0.7 (2.9) g/5 h) after HF than MF meal. Appetite (area under the curve (AUC)) was significantly reduced after an MF than an HF meal (494 (55) cm.300 min vs. 595 (57) cm.300 min, P < 0.05). Postprandial triglyceride concentration (AUC) was significantly (P < 0.05) higher after an HF than an MF meal: 141.1 (30.3) mmol.300 min/l vs. 79.3 (23.8) mmol.300 min/l, respectively. Peptide YY (PYY), cholecystokinin (CCK), and ghrelin concentrations (AUC) were not significantly different after an HF and MF meal. Glucagon-like peptide-1 (GLP-1) was significantly (P < 0.05) higher after an HF than after an MF meal (72.3 (9.8) ng/ml vs. 22.7 (7.6) ng/ml, respectively), but it did not affect subjective appetite. In conclusion, an MF meal induced a better postprandial metabolic nutrient balance, triglyceride levels, and appetite suppression than an HF meal. Gastrointestinal hormones were not related to clinically assessed hunger suppression after both meals. Topics: Appetite; Area Under Curve; Child; Cross-Sectional Studies; Dietary Carbohydrates; Dietary Fats; Energy Metabolism; Glucagon-Like Peptide 1; Humans; Male; Nutritive Value; Obesity; Postprandial Period; Triglycerides | 2010 |
Glucagon-like Peptide-1 receptor agonists activate rodent thyroid C-cells causing calcitonin release and C-cell proliferation.
Liraglutide is a glucagon-like peptide-1 (GLP-1) analog developed for type 2 diabetes. Long-term liraglutide exposure in rodents was associated with thyroid C-cell hyperplasia and tumors. Here, we report data supporting a GLP-1 receptor-mediated mechanism for these changes in rodents. The GLP-1 receptor was localized to rodent C-cells. GLP-1 receptor agonists stimulated calcitonin release, up-regulation of calcitonin gene expression, and subsequently C-cell hyperplasia in rats and, to a lesser extent, in mice. In contrast, humans and/or cynomolgus monkeys had low GLP-1 receptor expression in thyroid C-cells, and GLP-1 receptor agonists did not activate adenylate cyclase or generate calcitonin release in primates. Moreover, 20 months of liraglutide treatment (at >60 times human exposure levels) did not lead to C-cell hyperplasia in monkeys. Mean calcitonin levels in patients exposed to liraglutide for 2 yr remained at the lower end of the normal range, and there was no difference in the proportion of patients with calcitonin levels increasing above the clinically relevant cutoff level of 20 pg/ml. Our findings delineate important species-specific differences in GLP-1 receptor expression and action in the thyroid. Nevertheless, the long-term consequences of sustained GLP-1 receptor activation in the human thyroid remain unknown and merit further investigation. Topics: Animals; Blotting, Western; Calcitonin; Cell Line; Cell Proliferation; Cells, Cultured; Cyclic AMP; Diabetes Mellitus, Type 1; Dose-Response Relationship, Drug; Enzyme-Linked Immunosorbent Assay; Gene Expression; Glucagon-Like Peptide 1; Glucagon-Like Peptide-1 Receptor; Humans; Immunohistochemistry; In Situ Hybridization; Liraglutide; Macaca fascicularis; Mice; Mice, Knockout; Obesity; Radioimmunoassay; Rats; Rats, Sprague-Dawley; Receptors, Glucagon; Reverse Transcriptase Polymerase Chain Reaction; RNA, Messenger; Species Specificity; Thyroid Gland | 2010 |
Acute effect of walking on energy intake in overweight/obese women.
This study examined the acute effect of a bout of walking on hunger, energy intake, and appetite-regulating hormones [acylated ghrelin and glucagon-like peptide-1 (GLP-1)] in 19 overweight/obese women (BMI: 32.5 ± 4.3 kg/m²). Subjects underwent two experimental testing sessions in a counterbalanced order: exercise and rest. Subjects walked at a moderate-intensity for approximately 40 min or rested for a similar duration. Subjective feelings of hunger were assessed and blood was drawn at 5-time points (pre-, post-, 30-, 60-, 120-min post-testing). Ad libitum energy intake consumed 1-2h post-exercise/rest was assessed and similar between conditions (mean ± standard deviation; exercise: 551.5 ± 245.1 kcal [2.31 ± 1.0 MJ] vs. rest: 548.7 ± 286.9 kcal [2.29 ± 1.2 MJ]). However, when considering the energy cost of exercise, relative energy intake was significantly lower following exercise (197.8 ± 256.5 kcal [0.83 ± 1.1 MJ]) compared to rest (504.3 ± 290.1 kcal [2.11 ± 1.2 MJ]). GLP-1 was lower in the exercise vs. resting condition while acylated ghrelin and hunger were unaltered by exercise. None of these variables were associated with energy intake. In conclusion, hunger and energy intake were unaltered by a bout of walking suggesting that overweight/obese individuals do not acutely compensate for the energy cost of the exercise bout through increased caloric consumption. This allows for an energy deficit to persist post-exercise, having potentially favorable implications for weight control. Topics: Adult; Appetite Regulation; Energy Intake; Energy Metabolism; Female; Ghrelin; Glucagon-Like Peptide 1; Humans; Hunger; Obesity; Overweight; Rest; Walking; Young Adult | 2010 |
Dipeptidyl peptidase-4 inhibitors administered in combination with metformin result in an additive increase in the plasma concentration of active GLP-1.
The aim of the study was to investigate the effects of a dipeptidyl peptidase-4 (DPP-4) inhibitor, of metformin, and of the combination of the two agents, on incretin hormone concentrations. Active and inactive (or total) incretin plasma concentrations, plasma DPP-4 activity, and preproglucagon (GCG) gene expression were determined after administration of each agent alone or in combination to mice with diet-induced obesity (DIO) and to healthy human subjects. In mice, metformin increased Gcg expression in the large intestine and elevated the plasma concentrations of inactive glucagon-like peptide 1 (GLP-1) (9-36) and glucagon. In healthy subjects, a DPP-4 inhibitor elevated both active GLP-1 and glucose dependent insulinotropic polypeptide (GIP), metformin increased total GLP-1 (but not GIP), and the combination resulted in additive increases in active GLP-1 plasma concentrations. Metformin did not inhibit plasma DPP-4 activity either in vitro or in vivo. The study results show that metformin is not a DPP-4 inhibitor but rather enhances precursor GCG expression in the large intestine, resulting in increased total GLP-1 concentrations. DPP-4 inhibitors and metformin have complementary mechanisms of action and additive effects with respect to increasing the concentrations of active GLP-1 in plasma. Topics: Adolescent; Adult; Animals; Cross-Over Studies; Dipeptidyl-Peptidase IV Inhibitors; Double-Blind Method; Drug Therapy, Combination; Female; Glucagon-Like Peptide 1; Humans; Male; Metformin; Mice; Mice, Inbred C57BL; Middle Aged; Obesity; Young Adult | 2010 |
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 |
Reducing dietary fat from a meal increases the bioavailability of exogenous carbohydrate without altering plasma glucose concentration.
The primary goal of this study was to determine the acute glycemic and endocrine responses to the reduction of fat content from a meal. On three separate occasions, nine overweight subjects (body mass index = 30 +/- 1 kg/m(2); 5 men, 4 women) consumed 1) a control meal ( approximately 800 kcal; 100 g of carbohydrate, 31 g of fat, and 30 g of protein), 2) a low-fat meal ( approximately 530 kcal; 100 g of carbohydrate, 1 g of fat, and 30 g of protein), or 3) a low-fat meal plus lipid infusion [same meal as low-fat meal, but the total energy provided was the same as control (800 kcal), with the "missing" fat ( approximately 30 g) provided via an intravenous lipid infusion]. All three meals contained [(13)C]glucose (3 mg/kg body wt) to assess the bioavailability of ingested glucose. During the 5-h period after each meal, we measured the recovery of [(13)C]glucose in plasma, plasma glucose, and insulin concentrations. We also measured plasma concentration of the gastrointestinal peptides: glucose-dependent insulinotropic polypeptide (GIP), glucagon-like peptide-1 (GLP-1), and peptide YY(3-36) (PYY(3-36)). The recovery of the ingested [(13)C]glucose in the hour after ingestion was greater (P < 0.05) after the low-fat than after the control meal [area under the curve (AUC): 1,206 +/- 252 and 687 +/- 161 microM.h, respectively]. However, removing dietary fat from the meal did not affect the plasma concentration of glucose or insulin. Importantly, [(13)C]glucose recovery was not different during the low-fat and lipid infusion trials (AUC: 1,206 +/- 252 and 1,134 +/- 247 microM.h, respectively), indicating that the accelerated delivery of exogenous glucose found after removing fat from the meal is due exclusively to the reduction of fat in the gastrointestinal tract. In parallel with these findings, the reduction in fat calories from the meal reduced plasma concentration of GIP, GLP-1, and PYY(3-36). In summary, these data suggest that removing fat from the diet expedited exogenous glucose delivery into the systemic circulation and reduced the concentration of key gastrointestinal peptides, yet maintained plasma glucose concentration at control levels. Topics: Adult; Biological Availability; Blood Glucose; Carbon Isotopes; Diet, Fat-Restricted; Dietary Carbohydrates; Emulsions; Fat Emulsions, Intravenous; Female; Gastric Inhibitory Polypeptide; Glucagon-Like Peptide 1; Humans; Hunger; Insulin; Male; Obesity; Overweight; Peptide Fragments; Peptide YY; Phospholipids; Postprandial Period; Safflower Oil; Satiety Response; Soybean Oil; Treatment Outcome; Young Adult | 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 |
The effect of a high-MUFA, low-glycaemic index diet and a low-fat diet on appetite and glucose metabolism during a 6-month weight maintenance period.
We aimed to test the effects of three different weight maintenance diets on appetite, glucose and fat metabolism following an initial low-energy diet (LED) induced body weight loss. Following an 8-week LED and a 2-3-week refeeding period, 131 subjects were randomized to three diets for 6 months: MUFA, moderate-fat (35-45 energy percentage (E%) fat), high in MUFA with low glycaemic index; LF, low fat (20-30 E% fat) or CTR, control (35 E% fat). A meal test study was performed in a subgroup, before and after the 6-month dietary intervention, with forty-two subjects completing both meal tests. No difference in body weight, energy intake or appetite ratings were observed between diets. Both the LF and MUFA diets compared to CTR diet reduced postprandial glycaemia and insulinaemia and lowered fasting insulin from month 0 to month 6. Following the 8-week LED period lower levels of the appetite regulating peptides, pancreatic polypeptide, peptide YY, glucagon-like peptide-1 and glucagon-like peptide-2, along with increased appetite scores were seen in comparison to measurements performed after the 6-month dietary intervention. In conclusion, the two competing diets, MUFA and LF, were equally good with respect to glucose metabolism, whereas the CTR diet resembling the typical Western diet, high in SFA, sugar and high glycaemic carbohydrates, indicated associations to lowering of insulin sensitivity. Lower levels of appetite regulatory peptides along with increased appetite scores following an 8-week LED and 2-3-week refeeding period, suggest that strategies for physiological appetite control following a LED period are needed, in order to prevent weight regain. Topics: Adult; Analysis of Variance; Appetite Regulation; Area Under Curve; Blood Glucose; Body Mass Index; Body Weight; Diet, Fat-Restricted; Energy Intake; Fatty Acids, Monounsaturated; Female; Glucagon; Glucagon-Like Peptide 1; Glucagon-Like Peptide 2; Glycemic Index; Humans; Insulin; Male; Obesity; Pancreatic Polypeptide; Peptide YY; Time Factors; Triglycerides | 2009 |
Orlistat accelerates gastric emptying and attenuates GIP release in healthy subjects.
Orlistat, an inhibitor of digestive lipases, is widely used for the treatment of obesity. Previous reports on the effect of orally ingested orlistat together with a meal on gastric emptying and secretion of gut peptides that modulate postprandial responses are controversial. We investigated the effect of ingested orlistat on gastric emptying and plasma responses of gut peptides in response to a solid mixed meal with a moderate energy load. In healthy subjects, gastric emptying was determined using scintigraphy and studies were performed without and with 120 mg of orlistat in pellet form in random order. Orlistat shortened t lag and t half and decreased the area under the gastric emptying curve. Orlistat significantly attenuated the secretion of glucose-dependent insulinotropic polypeptide (GIP) but did not alter the plasma responses of cholecystokinin (CCK), glucagon-like peptide-1 (GLP-1), pancreatic polypeptide (PP), and insulin. There was no peptide YY (PYY) response. Area under the curve of gastric emptying was positively correlated with integrated secretion of GIP (r=0.786) in orlistat and was negatively correlated with integrated plasma response of GLP-1 (r=-0.75) in control experiments, implying that inhibition of fat absorption modifies determinants of gastric emptying of a meal. Orlistat administered similar to its use in obesity treatment accelerates gastric emptying of a solid mixed meal with a moderate energy load and profoundly attenuates release of GIP without appreciably altering plasma responses of CCK, GLP-1, and PP. Since GIP is being implemented in the development of obesity, its role in weight control attained by orlistat awaits further investigation. Topics: Adult; Anti-Obesity Agents; Blood Glucose; Eating; Enteric Nervous System; Gastric Emptying; Gastric Inhibitory Polypeptide; Glucagon-Like Peptide 1; Humans; Insulin; Lactones; Male; Obesity; Orlistat; Peptide YY; Radionuclide Imaging; Stomach; Young Adult | 2009 |
The effects of dietary fibre type on satiety-related hormones and voluntary food intake in dogs.
Depending on type and inclusion level, dietary fibre may increase and maintain satiety and postpone the onset of hunger. This 7-week study evaluated the effect of fibre fermentability on physiological satiety-related metabolites and voluntary food intake (VFI) in dogs. Sixteen healthy adult dogs were fed a low-fermentable fibre (LFF) diet containing 8.5 % cellulose or a high-fermentable fibre (HFF) diet containing 8.5 % sugarbeet pulp and 2 % inulin. Large intestinal fibre degradation was evaluated by apparent faecal digestibility of nutrients and faecal SCFA and NH3 concentrations. Postprandial blood samples were obtained to determine postprandial plasma glucose, insulin, total peptide tyrosine-tyrosine (PYY), total glucagon-like peptide-1 (GLP-1) and total ghrelin concentrations. At the end of the study, the dogs were given a single meal of a dry dog food to determine VFI. Dogs fed the HFF diet had a significantly higher large intestinal fibre degradation and production of SCFA compared with the dogs fed the LFF diet. The HFF-fed dogs tended (P = 0.058) to show a lower VFI at the end of the study. No treatment effects were found for postprandial plasma glucose, PYY, GLP-1 and ghrelin responses. The concentrations of these metabolites could not be related to the observed difference in VFI. The inclusion of fermentable fibre in canine diets may contribute to the prevention or mitigation of obesity through its effects on satiety. The underlying mechanisms require further investigation. Topics: Ammonia; Animals; Blood Glucose; Cellulose; Dietary Fiber; Dog Diseases; Dogs; Eating; Fatty Acids, Volatile; Feces; Female; Fermentation; Ghrelin; Glucagon-Like Peptide 1; Insulin; Inulin; Male; Obesity; Peptide YY; Satiation; Vegetables | 2009 |
The glucose-dependent insulinotropic polypeptide and glucose-stimulated insulin response to exercise training and diet in obesity.
Aging and obesity are characterized by decreased beta-cell sensitivity and defects in the potentiation of nutrient-stimulated insulin secretion by GIP. Exercise and diet are known to improve glucose metabolism and the pancreatic insulin response to glucose, and this effect may be mediated through the incretin effect of GIP. The purpose of this study was to assess the effects of a 12-wk exercise training intervention (5 days/wk, 60 min/day, 75% Vo(2 max)) combined with a eucaloric (EX, n = 10) or hypocaloric (EX-HYPO, pre: 1,945 +/- 190, post: 1,269 +/- 70, kcal/day; n = 9) diet on the GIP response to glucose in older (66.8 +/- 1.5 yr), obese (34.4 +/- 1.7 kg/m(2)) adults with impaired glucose tolerance. In addition to GIP, plasma PYY(3-36), insulin, and glucose responses were measured during a 3-h, 75-g oral glucose tolerance test. Both interventions led to a significant improvement in Vo(2 max) (P < 0.05). Weight loss (kg) was significant in both groups but was greater after EX-HYPO (-8.3 +/- 1.1 vs. -2.8 +/- 0.5, P = 0.002). The glucose-stimulated insulin response was reduced after EX-HYPO (P = 0.02), as was the glucose-stimulated GIP response (P < 0.05). Furthermore, after the intervention, changes in insulin (DeltaI(0-30)/DeltaG(0-30)) and GIP (Delta(0-30)) secretion were correlated (r = 0.69, P = 0.05). The PYY(3-36) (Delta(0-30)) response to glucose was increased after both interventions (P < 0.05). We conclude that 1) a combination of caloric restriction and exercise reduces the GIP response to ingested glucose, 2) GIP may mediate the attenuated glucose-stimulated insulin response after exercise/diet interventions, and 3) the increased PYY(3-36) response represents an improved capacity to regulate satiety and potentially body weight in older, obese, insulin-resistant adults. Topics: Aged; Blood Glucose; Body Mass Index; Diet, Reducing; Eating; Exercise; Female; Gastric Inhibitory Polypeptide; Glucagon-Like Peptide 1; Humans; Insulin; Insulin Resistance; Male; Obesity; Peptide Fragments; Peptide YY; Physical Fitness; Satiety Response | 2009 |
Weight loss during oligofructose supplementation is associated with decreased ghrelin and increased peptide YY in overweight and obese adults.
Rodent studies show that oligofructose promotes weight loss, stimulates satiety hormone secretion, reduces energy intake, and improves lipid profiles.. Our objective was to examine the effects of oligofructose supplementation on body weight and satiety hormone concentrations in overweight and obese adults.. This study was a randomized, double-blind, placebo-controlled trial. Forty-eight otherwise healthy adults with a body mass index (in kg/m2) > 25 were randomly assigned to receive 21 g oligofructose/d or a placebo (maltodextrin) for 12 wk. Body composition (by dual-energy X-ray absorptiometry); meal tolerance tests, including satiety hormone response; food intake; and subjective appetite ratings were determined.. There was a reduction in body weight of 1.03 +/- 0.43 kg with oligofructose supplementation, whereas the control group experienced an increase in body weight of 0.45 +/- 0.31 kg over 12 wk (P = 0.01). A lower area under the curve (AUC) for ghrelin (P = 0.004) and a higher AUC for peptide YY (PYY) with oligofructose (P = 0.03) coincided with a reduction in self-reported caloric intake (P < or = 0.05). Glucose decreased in the oligofructose group and increased in the control group between initial and final tests (P < or = 0.05). Insulin concentrations mirrored this pattern (P < or = 0.05). Oligofructose supplementation did not affect plasma active glucagon-like peptide 1 secretion. According to a visual analog scale designed to assess side effects, oligofructose was well tolerated.. Independent of other lifestyle changes, oligofructose supplementation has the potential to promote weight loss and improve glucose regulation in overweight adults. Suppressed ghrelin and enhanced PYY may contribute in part to the reduction in energy intake. The trial was registered at clinicaltrials.gov as NCT00522353. Topics: Adult; Area Under Curve; Blood Glucose; Dietary Supplements; Energy Intake; Female; Ghrelin; Glucagon-Like Peptide 1; Humans; Insulin; Male; Middle Aged; Obesity; Oligosaccharides; Overweight; Peptide YY; Weight Loss | 2009 |
Effects of liraglutide in the treatment of obesity: a randomised, double-blind, placebo-controlled study.
The frequency of obesity has risen dramatically in recent years but only few safe and effective drugs are currently available. We assessed the effect of liraglutide on bodyweight and tolerability in obese individuals without type 2 diabetes.. We did a double-blind, placebo-controlled 20-week trial, with open-label orlistat comparator in 19 sites in Europe. 564 individuals (18-65 years of age, body-mass index 30-40 kg/m2) were randomly assigned, with a telephone or web-based system, to one of four liraglutide doses (1.2 mg, 1.8 mg, 2.4 mg, or 3.0 mg, n=90-95) or to placebo (n=98) administered once a day subcutaneously, or orlistat (120 mg, n=95) three times a day orally. All individuals had a 500 kcal per day energy-deficit diet and increased their physical activity throughout the trial, including the 2-week run-in. Weight change analysed by intention to treat was the primary endpoint. An 84-week open-label extension followed. This study is registered with ClinicalTrials.gov, number NCT00422058.. Participants on liraglutide lost significantly more weight than did those on placebo (p=0.003 for liraglutide 1.2 mg and p<0.0001 for liraglutide 1.8-3.0 mg) and orlistat (p=0.003 for liraglutide 2.4 mg and p<0.0001 for liraglutide 3.0 mg). Mean weight loss with liraglutide 1.2-3.0 mg was 4.8 kg, 5.5 kg, 6.3 kg, and 7.2 kg compared with 2.8 kg with placebo and 4.1 kg with orlistat, and was 2.1 kg (95% CI 0.6-3.6) to 4.4 kg (2.9-6.0) greater than that with placebo. More individuals (76%, n=70) lost more than 5% weight with liraglutide 3.0 mg that with placebo (30%, n=29) or orlistat (44%, n=42). Liraglutide reduced blood pressure at all doses, and reduced the prevalence of prediabetes (84-96% reduction) with 1.8-3.0 mg per day. Nausea and vomiting occurred more often in individuals on liraglutide than in those on placebo, but adverse events were mainly transient and rarely led to discontinuation of treatment.. Liraglutide treatment over 20 weeks is well tolerated, induces weight loss, improves certain obesity-related risk factors, and reduces prediabetes.. Novo Nordisk A/S, Bagsvaerd, Denmark. Topics: Analysis of Variance; Anti-Obesity Agents; Body Mass Index; Dose-Response Relationship, Drug; Double-Blind Method; Europe; Female; Glucagon-Like Peptide 1; Humans; Injections, Subcutaneous; Lactones; Liraglutide; Logistic Models; Male; Obesity; Orlistat; Prediabetic State; Safety; Treatment Outcome; Waist Circumference; Weight Loss | 2009 |
Appetite-related gut peptides, ghrelin, PYY, and GLP-1 in obese women with and without binge eating disorder (BED).
BED is characterized by overeating with a loss of control. The primary aim of the study was to measure plasma concentrations of three key gut peptides influencing hunger (ghrelin) and satiety (PYY, GLP-1) to ascertain potential abnormalities in BED. The participants were 10 obese BED and 9 obese nonBED premenopausal women. They did not differ in age, 30.1+/-8.1 SD, BMI, 36.2+/-5.9, or % body fat, 43.3+/-5.7. Following a13-h overnight fast, blood was drawn (-15, 0, 5, 15, 30, 60, 90, 120 min) for measurement of total plasma concentrations of ghrelin, PYY and GLP-1, pre and post ingestion of a nutritionally complete liquid meal (1256 kJ) at 9 am (0-5 min). Ratings of hunger and fullness preceded each blood draw. Ghrelin was significantly lower premeal at -15 min (P=.05) and postmeal at 90 min (P=.027) and 120 min (P=.025) in the BED group as compared to the nonBED group. Ghrelin also declined less postprandially in the BED group (P=.019) with a longer time to the nadir value (P=.004). However, fasting and meal-related changes in levels of PYY and GLP-1 did not differ between the groups nor did ratings of hunger and fullness. Following a randomized cognitive behavior and dietary intervention, the ghrelin values in BED normalized. Prior to treatment, the lower fasting ghrelin in BED may be a consequence of down regulation by overeating. The lack of differences in the satiety promoting hormones, PYY and GLP-1, makes them unlikely contributors to the binge eating in BED. Topics: Adult; Analysis of Variance; Appetite Regulation; Bulimia Nervosa; Cognitive Behavioral Therapy; Counseling; Female; Ghrelin; Glucagon-Like Peptide 1; Humans; Linear Models; Obesity; Peptide YY; Postprandial Period; Satiation | 2008 |
Miglitol suppresses the postprandial increase in interleukin 6 and enhances active glucagon-like peptide 1 secretion in viscerally obese subjects.
Visceral obesity and insulin resistance are regarded as risk factors for atherosclerosis. Epidemiologic studies have demonstrated long-term anti-atherosclerotic effects with administration of alpha-glucosidase inhibitors. Alpha-glucosidase inhibitors also have been reported to enhance glucagon-like peptide 1 (GLP-1) secretion. We compared the postprandial effects of a single administration of miglitol and acarbose on glucose and lipid metabolism, on insulin requirement, on GLP-1 secretion, and on inflammatory and endothelial markers in viscerally obese subjects. Twenty-four viscerally obese subjects with relative insulin resistance participated in this study. Subjects were given a single dose of miglitol (50 mg), acarbose (100 mg), or placebo blindly and randomly before a meal in a crossover design. The meal loads after drug administration were tested 3 times within 2 weeks. We measured glucose, insulin, lipids, lipoprotein lipase, interleukin 6, intracellular adhesion molecule 1, vascular cell adhesion molecule 1, and active GLP-1 at before and various minutes after the meal. Single administration of both alpha-glucosidase inhibitors had several beneficial effects in improving postprandial hyperglycemia and reducing postprandial insulin requirement approximately 25% of placebo without adversely affecting lipid profiles. Although lipoprotein lipase levels within 2 hours after the meal did not show differences among miglitol, acarbose, and placebo administrations, miglitol significantly suppressed the increases in triglycerides, remnant-like particle triglycerides, and remnant-like particle cholesterol compared to acarbose and placebo in the early phase. Miglitol also significantly enhanced active GLP-1 secretion to a greater extent than acarbose (P < .01) and placebo (P < .001), and significantly suppressed the postprandial increase in interleukin 6 compared to placebo (P < .01). The results point to the potential suitability of miglitol as an anti-atherosclerotic effect in viscerally obese subjects, in preference to acarbose. Further studies are needed to elucidate the long-term effects on enhanced GLP-1 secretion and anti-atherosclerosis. Topics: 1-Deoxynojirimycin; Acarbose; Adult; Blood Glucose; Cross-Over Studies; Enzyme Inhibitors; Female; Glucagon-Like Peptide 1; Humans; Insulin; Intercellular Adhesion Molecule-1; Interleukin-6; Lipids; Lipoprotein Lipase; Male; Middle Aged; Obesity; Postprandial Period; Single-Blind Method; Vascular Cell Adhesion Molecule-1; Viscera | 2008 |
Long-term effects of consumption of a novel fat emulsion in relation to body-weight management.
To assess weight maintenance after weight loss by consumption of yoghurt with a novel fat emulsion (Olibra) including effects on body composition, resting energy expenditure (REE), fat oxidation, hunger feelings and satiety hormones.. A randomized, placebo-controlled, double-blind, parallel design. A 6-week weight loss period (2.1 MJ/day) was followed by 18 weeks weight maintenance with test (Olibra) or placebo yoghurt.. Fifty overweight women (age: 18-58 years, body mass index (BMI) 25-32 kg/m2).. In weeks 1, 7 and 25, a satiety test with questionnaires and blood samples for analysis of satiety hormones. In weeks 2, 8 and 26, REE, body weight and body composition.. During weight maintenance after significant body weight reduction, there was no significant increase in body weight in the test group (1.1+/-3.4 kg); the placebo group did gain weight (3.0+/-3.1 kg, P<0.001). Compared to the placebo group, the test group was less hungry 4 h after yoghurt consumption in week 25 (P<0.05) and showed increased glucagon like peptide-1 values 180 min after yoghurt consumption (week 25 vs week 1, P<0.05). Measured REE as a function of fat-free mass (FFM) was significantly higher than predicted REE (P<0.05) in week 26 for the test group, but not for the placebo group. Fat mass (FM) was significantly more decreased in the test group (6.5+/-4.1 kg) compared to the placebo group (4.1+/-3.6 kg) (week 26 vs week 2, P<0.05).. Consumption of Olibra yoghurt improved weight maintenance compared to placebo, which can be explained by the relatively higher REE as a function of FFM, relatively higher decrease in FM and the relatively lower increase in hunger. Topics: Adolescent; Adult; Appetite Depressants; Body Mass Index; Body Weight; Caloric Restriction; Cholecystokinin; Dietary Supplements; Double-Blind Method; Emulsions; Energy Metabolism; Fats; Female; Ghrelin; Glucagon-Like Peptide 1; Humans; Hunger; Middle Aged; Obesity; Overweight; Peptide Hormones; Satiety Response; Weight Gain; Weight Loss; Yogurt | 2007 |
The effect of single-dose orlistat on postprandial serum glucose, insulin and glucagon-like peptide-1 levels in nondiabetic obese patients.
Glucagon-like peptide-1 is an insulin secretion-stimulating gut hormone that is produced in response to food intake. Orlistat (Xenical, F. Hoffman-La Roche, Basel, Switzerland), which decreases fat absorption and increases intestinal fat content, may therefore affect the secretion of glucagon-like peptide-1. In this study we examined the immediate effects of orlistat on postprandial serum glucose, insulin and glucagon-like peptide-1 levels prior to a change in body weight.. Randomized, clinical study.. Sixteen nondiabetic obese patients (body mass index 35.7 +/- 3.8 kg/m(2), range 32.5-43.1) were enrolled in this study. The patients were randomly assigned to either the group treated with orlistat (120 mg, single dose) or the control group. There were eight patients in each of the two groups. Orlistat was given before a standard 600-kcal mixed meal containing 60% carbohydrates, 25% lipids and 15% protein. Blood samples were collected at baseline and at 30-min intervals for 180 min after the test meal. Graphical tendencies, peak value, time to reach the peak value, and area under the curve in the two groups were compared.. Blood samples were obtained for the measurement of GLP-1, glucose, insulin, high density lipoprotein, total cholesterol and triglycerides.. We found no difference in sex distribution, mean age, anthropometric measurements, or baseline glucose, insulin and glucagon-like peptide-1 levels between the orlistat and placebo groups. The peak insulin and glucagon-like peptide-1 levels were determined at 60 min in the control group. Hourly changes in serum glucose and insulin levels were similar between the groups, although the peak insulin and glucagon-like peptide-1 levels were reached at 120 min in the orlistat group. There were no statistically significant differences between the groups.. A single dose of 120-mg orlistat caused no change in postprandial serum glucose, insulin or glucagon-like peptide-1 levels in nondiabetic obese patients. Although glucagon-like peptide-1 increases were delayed in the orlistat group, these changes were nonsignificant. Topics: Adult; Anti-Obesity Agents; Blood Glucose; Diabetes Mellitus; Female; Glucagon-Like Peptide 1; Humans; Hyperglycemia; Insulin; Lactones; Male; Middle Aged; Obesity; Orlistat | 2007 |
Appetite hormones and energy intake in obese men after consumption of fructose, glucose and whey protein beverages.
To investigate appetite responses over 4 h to fructose beverages in obese men, relative to glucose and whey protein. Second, to investigate the effect of combining whey and fructose on postprandial appetite hormones.. Randomized, double-blind crossover study of four beverages (1.1 MJ) containing 50 g of whey, fructose, glucose or 25 g whey+25 g fructose. Blood samples and appetite ratings were collected for 4 h then a buffet meal was offered.. Twenty-eight obese men (age: 57.0+/-1.6 years, body mass index: 32.5+/-0.6 kg/m(2)).. Plasma ghrelin (total), glucagon-like peptide-1 (GLP-1 7-36), cholecystokinin-8, glucose, insulin and appetite ratings were assessed at baseline and 30, 45, 60, 90, 120, 180, 240 min after beverages, followed by measurement of ad libitum energy intake.. Fructose produced lower glycaemia and insulinaemia compared to the glucose treatment (P<0.0001); whereas postprandial ghrelin, GLP-1 and cholecystokinin responses were similar after both treatments. Whey protein produced a prolonged (2-4 h) suppression of ghrelin (P=0.001) and elevation of GLP-1 (P=0.002) and cholecystokinin (P=0.003) that were reduced when combined with fructose, while glucose and insulin responses were similar. Energy intake after 4 h was independent of beverage type (glucose 4.7+/-0.2 MJ; fructose 4.9+/-0.3 MJ; whey 4.6+/-0.3 MJ; whey/fructose 4.8+/-0.3 MJ; P>0.05).. In obese men, fructose- and glucose-based beverages had similar effects on appetite and associated regulatory hormones, independent of the differing glycaemic and insulinaemic responses. The contrasting profile of plasma ghrelin, GLP-1 and cholecystokinin after whey protein consumption did not impact on ad libitum intake 4 h later and was attenuated when 50% of whey was replaced with fructose. Topics: Appetite; Beverages; Blood Glucose; Cholecystokinin; Cross-Over Studies; Dietary Carbohydrates; Double-Blind Method; Energy Intake; Fructose; Ghrelin; Glucagon-Like Peptide 1; Glucose; Humans; Insulin; Male; Middle Aged; Milk Proteins; Obesity; Peptide Fragments; Peptide Hormones; Whey Proteins | 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 |
Appetite regulatory hormone responses to various dietary proteins differ by body mass index status despite similar reductions in ad libitum energy intake.
Although dietary protein produces higher acute satiety relative to carbohydrate, the influence of protein source and body mass index (BMI) has not been clearly described.. The objective of the study was to assess postprandial responses to different protein sources, compared with glucose, in males with normal and high BMI.. This was a randomized, crossover study of four preloads followed by blood sampling (+15, 30, 45, 60, 90, 120, 180 min) and buffet meal.. The study was conducted at an outpatient clinic.. The study population included 72 men, with a BMI range 20.6-39.9 kg/m(2).. Interventions consisted of liquid preloads (1.1 MJ, 450 ml) containing 50 g whey, soy, gluten, or glucose.. Fasting and postprandial plasma glucose, insulin, ghrelin, glucagon-like peptide-1 (GLP-1) and cholecystokinin (n = 38), ad libitum energy intake, and appetite ratings were measured.. Energy intake was 10% lower after all protein preloads, compared with the glucose treatment (P < 0.05), independent of BMI status and protein type. All protein loads prolonged the postprandial suppression of ghrelin (P < 0.01) and elevation of GLP-1 (P < 0.01) and cholecystokinin (P < 0.05). Fasting GLP-1 concentrations [overweight, 17.5 +/- 1.3; lean, 14.7 +/- 0.1 pg/ml (5.2 +/- 0.4 and 4.4 +/- 0.1 pmol/liter, respectively); P < 0.001] and postprandial responses (P = 0.038) were higher in overweight subjects.. Whey, soy, and gluten similarly tend to reduce ad libitum food intake 3 h later in lean and overweight males relative to glucose. Postprandial ghrelin, GLP-1, insulin, and cholecystokinin may contribute to this higher satiety after protein consumption. GLP-1 concentrations are increased in overweight subjects, which may affect satiety responses in this group. Topics: Adult; Aged; Appetite Regulation; Blood Glucose; Body Mass Index; Body Weight; Cholecystokinin; Cross-Over Studies; Dietary Proteins; Eating; Energy Intake; Ghrelin; Glucagon-Like Peptide 1; Glutens; Hormones; Humans; Insulin; Kinetics; Male; Middle Aged; Milk Proteins; Obesity; Peptide Hormones; Regression Analysis; Satiation; Soybean Proteins; Whey Proteins | 2006 |
Pharmacokinetics and pharmacodynamic effects of the oral DPP-4 inhibitor sitagliptin in middle-aged obese subjects.
Sitagliptin (MK-0431) is an oral, potent, and selective dipeptidyl peptidase-IV (DPP-4) inhibitor developed for the treatment of type 2 diabetes. This multicenter, randomized, double-blind, placebo-controlled study examined the pharmacokinetic and pharmacodynamic effects of sitagliptin in obese subjects. Middle-aged (45-63 years), nondiabetic, obese (body mass index: 30-40 kg/m2) men and women were randomized to sitagliptin 200 mg bid (n = 24) or placebo (n = 8) for 28 days. Steady-state plasma concentrations of sitagliptin were achieved within 2 days of starting treatment, and >90% of the dose was excreted unchanged in urine. Sitagliptin treatment led to approximately 90% inhibition of plasma DPP-4 activity, increased active glucagon-like peptide-1 (GLP-1) levels by 2.7-fold (P < .001), and decreased post-oral glucose tolerance test glucose excursion by 35% (P < .050) compared to placebo. In nondiabetic obese subjects, treatment with sitagliptin 200 mg bid was generally well tolerated without associated hypoglycemia and led to maximal inhibition of plasma DPP-4 activity, increased active GLP-1, and reduced glycemic excursion. Topics: Adenosine Deaminase; Adenosine Deaminase Inhibitors; Administration, Oral; Blood Glucose; Body Weight; Dipeptidyl Peptidase 4; Dipeptidyl-Peptidase IV Inhibitors; Double-Blind Method; Female; Glucagon-Like Peptide 1; Glucose Tolerance Test; Glycoproteins; Humans; Hypoglycemic Agents; Male; Middle Aged; Obesity; Pyrazines; Sitagliptin Phosphate; Triazoles | 2006 |
Glucagon-like peptide-1 release and satiety after a nutrient challenge in normal-weight and obese subjects.
The present study was conducted to assess whether glucagon-like peptide-1 (GLP-1) release and appetite after a breakfast with or without an additional galactose/guar gum stimulation is different in normal-weight compared with overweight/obese subjects. Twenty-eight overweight/obese (BMI 30.3 (sd 2.7) kg/m2; age 44.3 (sd 9.7) years) and thirty normal-weight subjects (BMI 22.8 (sd 1.4), age 31.5 (sd12.8) years) participated in a crossover study. Fasting and postprandial plasma GLP-1, insulin, glucose and free fatty acid concentrations were measured in response to either a galactose (50 g)/guar gum (2.5 g) load (836 kJ) and a standard breakfast (1.9 MJ; GG), or water (250 ml) and the standard breakfast (W) every 30 min relative to the ingestion for 120 min. Appetite was assessed using 100 mm visual analogue scales. GLP-1 concentrations were significantly increased after GG at 30 and 60 min compared with W in both groups. Plasma GLP-1 concentrations in the W condition were higher in normal-weight than overweight/obese subjects (P=0.03). No difference was observed in the GG condition between groups. Satiety was increased in normal-weight compared with overweight/obese subjects in the GG condition at 30 (P=0.02) and 60 (P=0.04) min. We conclude that after a standard breakfast with water, GLP-1 release was lower in the overweight/obese than the normal-weight subjects. However, postprandial GLP-1 release in overweight/obese subjects was no different from that of normal-weight subjects when galactose/guar gum was added to the breakfast. The latter was not mirrored by subjective feelings of satiety. Disturbed perception of the physiological feedback of a satiety hormone rather than disturbed feedback itself might contribute to obesity. Topics: Adult; Appetite Regulation; Blood Glucose; Cross-Over Studies; Dietary Fiber; Eating; Fatty Acids, Nonesterified; Female; Galactans; Galactose; Glucagon; Glucagon-Like Peptide 1; Humans; Insulin; Male; Mannans; Middle Aged; Obesity; Peptide Fragments; Plant Gums; Protein Precursors; Satiety Response | 2005 |
Peptide YY3-36 and glucagon-like peptide-17-36 inhibit food intake additively.
Peptide YY (PYY) and glucagon like peptide (GLP)-1 are cosecreted from intestinal L cells, and plasma levels of both hormones rise after a meal. Peripheral administration of PYY(3-36) and GLP-1(7-36) inhibit food intake when administered alone. However, their combined effects on appetite are unknown. We studied the effects of peripheral coadministration of PYY(3-36) with GLP-1(7-36) in rodents and man. Whereas high-dose PYY(3-36) (100 nmol/kg) and high-dose GLP-1(7-36) (100 nmol/kg) inhibited feeding individually, their combination led to significantly greater feeding inhibition. Additive inhibition of feeding was also observed in the genetic obese models, ob/ob and db/db mice. At low doses of PYY(3-36) (1 nmol/kg) and GLP-1(7-36) (10 nmol/kg), which alone had no effect on food intake, coadministration led to significant reduction in food intake. To investigate potential mechanisms, c-fos immunoreactivity was quantified in the hypothalamus and brain stem. In the hypothalamic arcuate nucleus, no changes were observed after low-dose PYY(3-36) or GLP-1(7-36) individually, but there were significantly more fos-positive neurons after coadministration. In contrast, there was no evidence of additive fos-stimulation in the brain stem. Finally, we coadministered PYY(3-36) and GLP-1(7-36) in man. Ten lean fasted volunteers received 120-min infusions of saline, GLP-1(7-36) (0.4 pmol/kg.min), PYY(3-36) (0.4 pmol/kg.min), and PYY(3-36) (0.4 pmol/kg.min) + GLP-1(7-36) (0.4 pmol/kg.min) on four separate days. Energy intake from a buffet meal after combined PYY(3-36) + GLP-1(7-36) treatment was reduced by 27% and was significantly lower than that after either treatment alone. Thus, PYY(3-36) and GLP-1(7-36), cosecreted after a meal, may inhibit food intake additively. Topics: Animals; Behavior, Animal; Diabetes Mellitus; Dose-Response Relationship, Drug; Double-Blind Method; Drug Combinations; Drug Synergism; Eating; Energy Intake; Feeding Behavior; Female; Glucagon; Glucagon-Like Peptide 1; Glucagon-Like Peptides; Humans; Immunohistochemistry; Injections, Intraperitoneal; Male; Mice; Mice, Inbred C57BL; Motor Activity; Obesity; Peptide Fragments; Peptide YY; Rats | 2005 |
Race affects insulin and GLP-1 secretion and response to a long-acting somatostatin analogue in obese adults.
This study investigated (1) the effect of octreotide-LAR (Sandostatin-LAR Depot; Novartis) on the enteroinsular axis in a biracial cohort of severely obese adults, (2) whether octreotide suppression of insulin secretion occurs by both a direct beta-cell effect and through mediating a glucagon-like peptide 1 (GLP-1) response, and (3) whether differences in GLP-1 concentrations could explain racial differences in insulin concentrations.. Prospective, open-label trial using a pre-post test design.. Single university, clinical research center.. In all, 42 healthy, severely obese Caucasian and African-American (AA) adults (93% female, 64% Caucasian, age=37.8+/-1.2 y, weight=123+/-4.2 kg, BMI=44.5+/-1 kg/m(2)), recruited through physician referral and newspaper ads, participated in the study.. Indices of beta-cell activity, insulin and GLP-1 response before and during a 75-gm oral glucose tolerance test were determined before and after 24 weeks of octreotide-LAR.. AA exhibited higher beta-cell activity, and insulin and GLP-1 concentrations than Caucasians. Octreotide-LAR suppressed the insulin and GLP-1 levels in both groups. Topics: Adult; Anthropometry; Black or African American; Female; Gastrointestinal Agents; Glucagon; Glucagon-Like Peptide 1; Glucose Tolerance Test; Humans; Insulin; Insulin Secretion; Male; Obesity; Octreotide; Peptide Fragments; Prospective Studies; Protein Precursors; White People | 2004 |
Prandial subcutaneous injections of glucagon-like peptide-1 cause weight loss in obese human subjects.
Recombinant glucagon-like peptide-1 (7-36)amide (rGLP-1) was recently shown to cause significant weight loss in type 2 diabetics when administered for 6 weeks as a continuous subcutaneous infusion. The mechanisms responsible for the weight loss are not clarified. In the present study, rGLP-1 was given for 5 d by prandial subcutaneous injections (PSI) (76 nmol 30 min before meals, four times daily; a total of 302.4 nmol/24 h) or by continuous subcutaneous infusion (CSI) (12.7 nmol/h; a total of 304.8 nmol/24 h). This was performed in nineteen healthy obese subjects (mean age 44.2 (sem 2.5) years; BMI 39.0 (sem 1.2) kg/m(2)) in a prospective randomised, double-blind, placebo-controlled, cross-over study. Compared with the placebo, rGLP-1 administered as PSI and by CSI generated a 15 % reduction in mean food intake per meal (P=0.02) after 5 d treatment. A weight loss of 0.55 (sem 0.2) kg (P<0.05) was registered after 5 d with PSI of rGLP-1. Gastric emptying rate was reduced during both PSI (P<0.001) and CSI (P<0.05) treatment, but more rapidly and to a greater extent with PSI of rGLP-1. To conclude, a 5 d treatment of rGLP-1 at high doses by PSI, but not CSI, promptly slowed gastric emptying as a probable mechanism of action of increased satiety, decreased hunger and, hence, reduced food intake with an ensuing weight loss. Topics: Adult; Cross-Over Studies; Double-Blind Method; Eating; Feeding Behavior; Female; Gastric Emptying; Glucagon; Glucagon-Like Peptide 1; Humans; Hunger; Infusions, Parenteral; Injections, Subcutaneous; Male; Middle Aged; Nausea; Obesity; Peptide Fragments; Protein Precursors; Recombinant Proteins; Satiation; Thirst; Weight Loss | 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 |
Glucagon-like peptide 1 induces natriuresis in healthy subjects and in insulin-resistant obese men.
Glucagon-like peptide-1-(7-36)-amide (GLP-1) is involved in satiety control and glucose homeostasis. Animal studies suggest a physiological role for GLP-1 in water and salt homeostasis. This study's aim was to define the effects of GLP-1 on water and sodium excretion in both healthy and obese men. Fifteen healthy subjects and 16 obese men (mean body mass index, 36 kg/m2) were examined in a double-blind, placebo-controlled, crossover study to demonstrate the effects of a 3-h infusion of GLP-1 on urinary sodium excretion, urinary output, and the glomerular filtration rate after an i.v. 9.9-g salt load. Infusion of GLP-1 evoked a dose-dependent increase in urinary sodium excretion in healthy subjects (from 74 +/- 8 to 143 +/- 18 mmol/180 min, P = 0.0013). In obese men, there was a significant increase in urinary sodium excretion (from 59 to 96 mmol/180 min, P = 0.015), a decrease in urinary H+ secretion (from 1.1 to 0.3 pmol/180 min, P = 0.013), and a 6% decrease in the glomerular filtration rate (from 151 +/- 8 to 142 +/- 8 ml/min, P = 0.022). Intravenous infusions of GLP-1 enhance sodium excretion, reduce H+ secretion, and reduce glomerular hyperfiltration in obese men. These findings suggest an action at the proximal renal tubule and a potential renoprotective effect. Topics: Adult; Blood Glucose; Cross-Over Studies; Double-Blind Method; Drinking; Glomerular Filtration Rate; Glucagon; Glucagon-Like Peptide 1; Humans; Insulin; Insulin Resistance; Kidney Tubules, Proximal; Male; Natriuresis; Obesity; Peptide Fragments; Protein Precursors; Protons; Renin; Renin-Angiotensin System; Sodium; Thirst; Urine | 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 |
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 |
Plasma glucagon-like peptide-1 (GLP-1) responses to duodenal fat and glucose infusions in lean and obese men.
It has been suggested that obesity is associated with a reduced glucagon-like peptide-1 (GLP-1) response to oral carbohydrate, but not fat. The latter may, however, be attributable to changes in gastric emptying. We have assessed plasma GLP-1 levels in response to these infusions in lean and obese subjects. Seven healthy lean (body mass index (BMI), 19.1-24.6 kg/m(2)) and seven obese (BMI, 31.3-40.8 kg/m(2)) young men received an intraduodenal infusion of glucose and fat for 120 min (2.86 kcal/min) on two separate days. Blood samples for plasma GLP-1 were obtained at baseline and every 20 min during the infusion. Plasma GLP-1 increased during infusion of glucose and fat (P = 0.001), but there were no differences between lean and obese subjects, nor the two nutrients. We conclude that GLP-1 secretion in response to duodenal infusion of glucose and fat is not altered in obese subjects. Topics: Adolescent; Adult; Dietary Fats; Glucagon; Glucagon-Like Peptide 1; Glucose; Humans; Male; Obesity; Peptide Fragments; Protein Precursors; Thinness | 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 |
Effect of metformin on glucagon-like peptide 1 (GLP-1) and leptin levels in obese nondiabetic subjects.
To evaluate the effects of metformin on glucagon-like peptide 1 (GLP-1) and leptin levels.. A total of 10 obese nondiabetic male patients were studied before and after a 14-day treatment with 2,550 mg/day metformin and were compared with 10 untreated obese control subjects. On days 0 and 15, leptin and GLP-1(7-36)amide/(7-37) levels were assessed before and after an oral glucose load during a euglycemic hyperinsulinemic clamp to avoid the interference of variations of insulinemia and glycemia on GLP-1 and leptin secretion. The effects of metformin on GLP-1(7-36)amide degradation in human plasma and in a buffer solution containing dipeptidyl peptidase IV (DPP-IV) were also studied.. Leptin levels were not affected by the oral glucose load, and they were not modified after metformin treatment. Metformin induced a significant (P < 0.05) increase of GLP-1(7-36)amide/(7-37) at 30 and 60 min after the oral glucose load (63.8 +/- 29.0 vs. 50.3 +/- 15.6 pmol/l and 75.8 +/- 35.4 vs. 46.9 +/- 20.0 pmol/l, respectively), without affecting baseline GLP-1 levels. No variations of GLP-1 levels were observed in the control group. In pooled human plasma, metformin (0.1-0.5 microg/ml) significantly inhibited degradation of GLP-1(7-36)amide after a 30-min incubation at 37 degrees C; similar results were obtained in a buffer solution containing DPP-IV.. Metformin significantly increases GLP-1 levels after an oral glucose load in obese nondiabetic subjects; this effect could be due to an inhibition of GLP-1 degradation. Topics: Adolescent; Adult; Blood Glucose; Glucagon; Glucagon-Like Peptide 1; Glucagon-Like Peptides; Glucose Clamp Technique; Humans; Hypoglycemic Agents; Leptin; Male; Metformin; Middle Aged; Obesity; Peptide Fragments; Peptides | 2001 |
The effect of physiological levels of glucagon-like peptide-1 on appetite, gastric emptying, energy and substrate metabolism in obesity.
Peripheral infusions of glucagon-like peptide-1 (GLP-1) in humans have been shown to inhibit gastrointestinal motility and decrease hunger and energy intake. However, these investigations used supraphysiological doses. The objective of this study was to investigate the effects of a GLP-1 infusion in a physiological dose on appetite sensations, energy intake, gastric emptying, energy and substrate metabolism.. Eighteen obese men participated in the placebo-controlled, randomized, single-blinded, cross-over study with infusion of GLP-1 or saline. Resting metabolic rate (RMR) and substrate oxidations were measured by ventilated hood before and after an energy-fixed breakfast. Gastric emptying was measured using paracetamol as a marker. Visual analogue scales were used to assess appetite sensations, thirst and comfort throughout the experiment and palatability of the test meals. Blood was sampled for analysis of hormones (GLP-1, GLP-2, glucose-dependent insulinotropic polypeptide (GIP), insulin, glucagon), and substrates (glucose, lactate, non-esterified fatty acids (NEFA), triacylglycerol (TAG)). Ad libitum energy intake at lunch was registered.. Following the breakfast, GLP-1 infusion suppressed ratings of hunger and prospective food consumption (P<0.05), whereas all other subjective ratings and ad libitum energy intake were unaffected. RMR, carbohydrate oxidation and gastric emptying rate were lower during the GLP-1 infusion compared with the saline infusion (P<0.001, P<0.05, P<0.0001, respectively). All plasma hormone and substrate profiles, except NEFA, were significantly reduced by GLP-1 (P<0.0001).. It is concluded that GLP-1 in physiological concentrations powerfully reduces the rate of entry of nutrients into the circulation by a reduction of gastric emptying rate in obese subjects. The effect of GLP-1 on appetite and food intake may be beneficial in weight reduction. Topics: Adult; Appetite; Basal Metabolism; Body Mass Index; Energy Metabolism; Gastric Emptying; Glucagon; Glucagon-Like Peptide 1; Humans; Kinetics; Male; Obesity; Oxidation-Reduction; Peptide Fragments; Protein Precursors | 2001 |
Energy intake and appetite are suppressed by glucagon-like peptide-1 (GLP-1) in obese men.
Peripheral administration of glucagon-like peptide-1 (GLP-1) for four hours, to normal weight and obese humans, decreases food intake and suppresses appetite.. The aim of this study was to assess the effect of an eight hour infusion of GLP-1 on appetite and energy intake at lunch and dinner in obese subjects.. Randomised, blinded cross-over design with intravenous infusion of GLP-1 (0.75 pmol x kg(-1) min(-1)) or saline.. Eight obese (body mass index, BMI, 45.5 +/- 2.3 kg/m2) male subjects.. Ad libitum energy intake at lunch (12.00 h) and dinner (16.00 h) after an energy fixed breakfast (2.4 MJ) at 08.00 h. Appetite sensations using visual analogue scales, (VAS) immediately before and after meals and hourly in-between. Blood samples for the analysis of glucose, insulin, C-peptide, GLP-1 and peptide YY. Gastric emptying after breakfast and lunch using a paracetamol absorption technique.. Hunger ratings were significantly lower with GLP-1 infusion. The summed ad libitum energy intake at lunch and dinner was reduced by 1.7 +/- 0.5 MJ (21 +/- 6%) by GLP-1 infusion (P = 0.01). Gastric emptying was delayed by GLP-1 infusion, and plasma glucose concentrations decreased (baseline: 6.6 +/- 0.35 mmol/L; nadir: 5.3 +/- 0.15 mmol/L). No nausea was recorded during GLP-1 infusion.. Our results demonstrate that GLP-1 decreases feelings of hunger and reduces energy intake in obese humans. One possible mechanism for this finding might be an increased satiety primarily mediated by gastric vagal afferent signals. Topics: Adult; Appetite; Blood Glucose; Body Mass Index; C-Peptide; Cross-Over Studies; Double-Blind Method; Eating; Energy Intake; Gastric Emptying; Glucagon; Glucagon-Like Peptide 1; Humans; Hunger; Infusions, Intravenous; Insulin; Male; Obesity; Peptide Fragments; Peptide YY; Protein Precursors | 1999 |
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 |
Glucagon-like peptide 1 increases the period of postprandial satiety and slows gastric emptying in obese men.
The gut peptide glucagon-like peptide 1(7-36) amide (GLP-1) is released into the circulation after food intake. GLP-1 has been shown to have an incretin effect and inhibits gastrointestinal motility in humans. In rats, intracerebral administration of GLP-1 results in reduced food intake. Obese humans have been found to have an attenuated plasma GLP-1 response to a mixed meal. To approximate the physiologic state, GLP-1 or saline was administered intravenously and randomly at the beginning of a test meal served on a universal eating monitor to 6 obese subjects to test our hypothesis that GLP-1 influences termination of food intake (and thus food intake during a meal) and feelings of satiety in humans. As a marker for gastric emptying, 1.5 g acetaminophen was given at the start of the meal. Blood samples for analysis of acetaminophen, insulin, glucose, glucagon, and C-peptide were obtained. Hunger, fullness, and food choice were assessed with visual analogue scales and food-choice questionnaires. GLP-1 infusion resulted in a prolonged period of reduced feelings of hunger, desire to eat, and prospective consumption after the meal. The rate of gastric emptying was slower during infusion of GLP-1. Postprandial blood glucose concentrations were reduced during the GLP-1 infusion, but the amount of energy consumed, eating rate, and plasma concentrations of insulin, glucagon, and C-peptide were unchanged. GLP-1 given exogenously at the start of a meal did not seem to affect meal termination or the amount of food eaten. However, postprandial feelings of hunger decreased, suggesting that exogenous GLP-1 may influence feelings of hunger and satiety in humans. Topics: Adult; Blood Glucose; C-Peptide; Double-Blind Method; Gastric Emptying; Glucagon; Glucagon-Like Peptide 1; Humans; Hunger; Infusions, Intravenous; Insulin; Male; Obesity; Pain Measurement; Peptide Fragments; Postprandial Period; Protein Precursors; Radioimmunoassay; Satiation | 1998 |
668 other study(ies) available for glucagon-like-peptide-1 and Obesity
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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 |
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 |
Association Between Gut Hormones and Weight Change After Bariatric Arterial Embolization: Results from the BEAT Obesity Trial.
To evaluate associations of ghrelin, glucagon-like peptide 1 (GLP-1), and peptide YY 3-36 (PYY3-36) with weight change after bariatric arterial embolization (BAE).. Subgroup analysis of data collected during the BEAT Obesity Trial involving 7 participants with BMI > 40 who were embolized with 300- to 500-μm Embosphere Microspheres. Three participants were characterized as "responders" (top tertile of weight loss at each visit) and 4 as "non-responders" (bottom tertile of weight loss at each visit). Mean ± standard deviation participant age was 44 ± 11 years, and 6 of 7 participants were women. Participants were evaluated at baseline, 2 weeks, and 1, 3, 6, and 12 months after BAE. After fasting, participants consumed a mixed meal test at each visit; blood samples were collected at 0, 15, 30, 60, 120, 180, and 240 min. Study outcome measures were changes in weight from baseline and plasma serum hormone levels.. Percentage change in ghrelin decreased significantly in non-responders at 60 and 120 min at 1 and 12 months (estimated difference between 60 vs. 0 min at 1 month: 69% [95% CI - 126%, - 13%]; estimated difference between 120 vs. 0 min at 12 months: - 131% (95% CI - 239%, - 23%]). Responders had significantly lower ghrelin and greater weight loss than non-responders at 6 and 12 months. GLP-1 and PYY3-36 levels did not differ between groups.. Participants with consistent weight loss throughout follow-up had lower ghrelin than non-responders, supporting decreased ghrelin as a mechanism underlying BAE-induced weight loss.. High-quality randomized trial or prospective study; testing of previously developed diagnostic criteria on consecutive patients; sensible costs and alternatives; values obtained from many studies with multiway sensitivity analyses; systematic review of Level I RCTs and Level I studies. Topics: Adult; Bariatrics; Female; Ghrelin; Glucagon-Like Peptide 1; Humans; Male; Middle Aged; Obesity; Prospective Studies; Weight Loss | 2023 |
Hypothalamic integrity is necessary for sustained weight loss after bariatric surgery: A prospective, cross-sectional study.
The hypothalamus is the main integrator of peripheral and central signals in the control of energy homeostasis. Its functional relevance for the effectivity of bariatric surgery is not entirely elucidated. Studying the effects of bariatric surgery in patients with hypothalamic damage might provide insight.. Prospective study to analyze the effects of bariatric surgery in patients with hypothalamic obesity (HO) vs. matched patients with common obesity (CO) with and without bariatric surgery.. 65 participants were included (HO-surgery: n = 8, HO-control: n = 10, CO-surgery: n = 12, CO-control: n = 12, Lean-control: n = 23). Body weight, levels of anorexic hormones, gut microbiota, as well as subjective well-being/health status, eating behavior, and brain activity (via functional MRI) were evaluated.. Patients with HO lost significantly less weight after bariatric surgery than CO-participants (total body weight loss %: 5.5 % vs. 26.2 %, p = 0.0004). After a mixed meal, satiety and abdominal fullness tended to be lowest in HO-surgery and did not correlate with levels of GLP-1 or PYY. Levels of PYY (11,151 ± 1667 pmol/l/h vs. 8099 ± 1235 pmol/l/h, p = 0.028) and GLP-1 (20,975 ± 2893 pmol/l/h vs. 13,060 ± 2357 pmol/l/h, p = 0.009) were significantly higher in the HO-surgery vs. CO-surgery group. Abundance of Enterobacteriaceae and Streptococcus was increased in feces of HO and CO after bariatric surgery. Comparing HO patients with lean-controls revealed an increased activation in insula and cerebellum to viewing high-caloric foods in left insula and cerebellum in fMRI.. Hypothalamic integrity is necessary for the effectiveness of bariatric surgery in humans. Peripheral changes after bariatric surgery are not sufficient to induce satiety and long-term weight loss in patients with hypothalamic damage. Topics: Bariatric Surgery; Cross-Sectional Studies; Gastric Bypass; Glucagon-Like Peptide 1; Humans; Hypothalamic Diseases; Hypothalamus; Obesity; Prospective Studies; Weight Loss | 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 |
Effect of fasting on short-term visual plasticity in adult humans.
Brain plasticity and function is impaired in conditions of metabolic dysregulation, such as obesity. Less is known on whether brain function is also affected by transient and physiological metabolic changes, such as the alternation between fasting and fed state. Here we asked whether these changes affect the transient shift of ocular dominance that follows short-term monocular deprivation, a form of homeostatic plasticity. We further asked whether variations in three of the main metabolic and hormonal pathways affected in obesity (glucose metabolism, leptin signalling and fatty acid metabolism) correlate with plasticity changes. We measured the effects of 2 h monocular deprivation in three conditions: post-absorptive state (fasting), after ingestion of a standardised meal and during infusion of glucagon-like peptide-1 (GLP-1), an incretin physiologically released upon meal ingestion that plays a key role in glucose metabolism. We found that short-term plasticity was less manifest in fasting than in fed state, whereas GLP-1 infusion did not elicit reliable changes compared to fasting. Although we confirmed a positive association between plasticity and supraphysiological GLP-1 levels, achieved by GLP-1 infusion, we found that none of the parameters linked to glucose metabolism could predict the plasticity reduction in the fasting versus fed state. Instead, this was selectively associated with the increase in plasma beta-hydroxybutyrate (B-OH) levels during fasting, which suggests a link between neural function and energy substrates alternative to glucose. These results reveal a previously unexplored link between homeostatic brain plasticity and the physiological changes associated with the daily fast-fed cycle. Topics: Adult; Fasting; Glucagon-Like Peptide 1; Glucose; Humans; Insulin; Obesity | 2023 |
Hypothalamic anorexigenic signaling pathways (leptin, amylin, and proopiomelanocortin) are semaglutide (GLP-1 analog) targets in obesity control in mice.
Topics: Animals; Glucagon-Like Peptide 1; Hypothalamus; Islet Amyloid Polypeptide; Leptin; Mice; Obesity; Pro-Opiomelanocortin; Signal Transduction | 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 |
Obesity medication lorcaserin activates brainstem GLP-1 neurons to reduce food intake and augments GLP-1 receptor agonist induced appetite suppression.
Overweight and obesity are endemic in developed countries, with a substantial negative impact on human health. Medications developed to treat obesity include agonists for the G-protein coupled receptors glucagon-like peptide-1 (GLP-1R; e.g. liraglutide), serotonin 2C (5-HT. We profiled PPG neurons in the nucleus of the solitary tract (PPG. We found that 5-HT. These findings identify a necessary mechanism through which obesity medication lorcaserin produces its therapeutic benefit, namely brainstem PPG Topics: Appetite; Eating; Glucagon-Like Peptide 1; Glucagon-Like Peptide-1 Receptor; Humans; Liraglutide; Neurons; Obesity; Serotonin; Solitary Nucleus | 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 |
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 |
Activity-balanced GLP-1/GDF15 dual agonist reduces body weight and metabolic disorder in mice and non-human primates.
Obesity is a considerable health concern with limited pharmacotherapy options of low efficacy. Here, we develop a GLP-1/GDF15 fusion protein and explore its weight-lowering potential in animals. The molecule, QL1005, is engineered via fusing GLP-1 and GDF15 analogs by a peptide linker and conjugating it to a fatty acid for time-action extension. In vitro, the potency of QL1005 is superior to the GLP-1 analog semaglutide. In obese mice, QL1005 induces reductions in body weight, food intake, insulin, fasting glucose, and triglycerides. Notably, these metabolic effects come as a result of activities emanating from both GLP-1 and GDF15, in an individual pathway-balanced fashion. In a cynomolgus monkey model of obesity, QL1005 reduces body weight, food intake, insulin, and glucose in a dose-dependent manner with limited incidence of GI side effects. Altogether, this long-acting, dual GLP-1/GDF15 molecule demonstrates the promise of poly-pharmaceutical approaches in metabolic drug discovery and development. Topics: Animals; Body Weight; Glucagon-Like Peptide 1; Glucose; Growth Differentiation Factor 15; Insulin; Macaca fascicularis; Metabolic Diseases; Mice; Obesity; Weight Loss | 2023 |
Analysis of the Efficacy and the Long-term Metabolic and Nutritional Status of Sleeve Gastrectomy with Transit Bipartition Compared to Roux-en-Y Gastric Bypass in Obese Rats.
Sleeve gastrectomy with transit bipartition (SG-TB) could be an attractive alternative to Roux-en-Y gastric bypass (RYGB) on weight loss and improvement of comorbidities in patients with obesity. However, there is little long-term data. Translational research on a rat model could allow long-term projection to assess efficacy and safety of SG-TB. The aim of this research was to evaluate the long-term efficacy and safety of SG-TB compared to RYGB and SHAM in rat model.. Ninety-four male obese Wistar rats were distributed into 3 groups: SG-TB (n = 34), RYGB (n = 32), and SHAM (control group, n = 28). The percentage of total weight loss (%TWL), coprocalorimetry, glucose and insulin tolerance test, insulin, GLP-1, PYY, and GIP before and after surgery were assessed. The animals were followed over 6 months (equivalent to 16 years in humans).. At 6 months, %TWL was significantly greater(p = 0.025) in the SG-TB group compared to the RYGB group. There was no difference between the groups (p = 0.86) in malabsorption 15 and 120 days postoperatively. Glucose tolerance was significantly improved (p = 0.03) in the SG-TB and RYGB groups compared to the preoperative state. Insulin secretion, at 3 months, was significantly more important in the SG-TB group (p = 0.0003), compared to the RYGB and SHAM groups. GLP-1 secretion was significantly increased in the SG-TB and RYGB groups compared to the preoperative state (p = 0.001) but similar between SG-TB and RYGB animals (p = 0.72).. In a rat model, at long term compared to RYGB, SG-TB provides greater and better-maintained weight loss and an increased insulin secretion without impairing nutritional status. Topics: Animals; Gastrectomy; Gastric Bypass; Glucagon-Like Peptide 1; Glucose; Humans; Insulin; Male; Nutritional Status; Obesity; Obesity, Morbid; Rats; Rats, Wistar; Retrospective Studies; Treatment Outcome; Weight Loss | 2023 |
Weight loss by calorie restriction does not alter appetite-regulating gut hormone responses from perfused rat small intestine.
Postprandial secretion of the appetite-inhibiting hormones, glucagon-like peptide-1 (GLP-1), and peptide YY are reduced with obesity. It is unclear if the reduced secretion persists following weight loss (WL), if other appetite-inhibiting hormones are also reduced, and if so whether reduced secretion results from intrinsic changes in the gut.. To address whether WL may restore secretion of GLP-1 and other appetite-inhibiting hormones, we performed a gut perfusion study of the small intestine in diet-induced obese (DIO) rats after WL. A 20% weight loss (means ± SEM (g): 916 ± 53 vs. 703 ± 35, p < 0.01, n = 7) was induced by calorie restriction, and maintained stable for ≥7 days prior to gut perfusion to allow for complete renewal of enteroendocrine cells. Age-matched DIO rats were used as comparator. Several gut hormones were analyzed from the venous effluent, and gene expression was performed on gut tissue along the entire length of the intestine.. Secretion of cholecystokinin, gastrin, glucose-dependent insulinotropic peptide, GLP-1, neurotensin, and somatostatin was not affected by WL during basal conditions (p ≥ 0.25) or in response to macronutrients and bile acids (p ≥ 0.14). Glucose absorption was indistinguishable following WL. The expression of genes encoding the studied peptides, macronutrient transporters (glucose, fructose, and di-/tripeptides) and bile acid receptors did also not differ between DIO and WL groups.. These data suggest that the attenuated postprandial responses of GLP-1, as well as reduced responses of other appetite-inhibiting gut hormones, in people living with obesity may persist after weight loss and may contribute to their susceptibility for weight regain. Topics: Animals; Appetite; Caloric Restriction; Glucagon-Like Peptide 1; Glucose; Intestine, Small; Obesity; Rats; Weight Loss | 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 |
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 |
Effects of Lactobacillus acidophilus administration to anorexigenic neuropeptides and some biochemical parameters on rats fed with a high-fat diet.
One of the rapidly rising global public health concern is obesity. Over the past three decades, the prevalence of obesity has doubled/tripled in several nations around the world, most likely as a result of urbanization, sedentary lifestyles, and increased intake of high-calorie processed foods. In this study, it was aimed to investigate the effects of Lactobacillus acidophilus administration on rats exposed to high-fat diet experimentally on anorexigenic peptides in the brain and some biochemical parameters in the serum.. In the study, 4 different experimental groups were formed. Group 1 was designated as the control group and fed with a standard rat chow (SD). Group 2 was designated as the high-fat diet (HFD) fed group. Group 3 fed with SD and L. acidophilus probiotic administered. Group 4 fed with HFD and L. acidophilus probiotic administered. At the end of the experiment, leptin, serotonin, glucagon-like peptide-1 (GLP-1) levels were measured in the brain tissue and serum. Glucose, total cholesterol (TC), triglyceride (TG), total protein (TP), albumin, uric acid, aspartate transaminase (AST), alanine aminotransferase (ALT) levels were determined in the serum.. At the end of the study, it was found that there was an increase in body weight and body mass index in Group 2 compared to Group 1. It was determined that the levels of AST, ALT, TG, TC, glucose, leptin in the serum were significantly high (P < 0.05). The levels of GLP-1 and serotonin in the serum and in the brain were significantly low (P < 0.05). There was a significant decrease in TG and TC in Groups 3 and 4 compared to Group 2 (P < 0.05). The leptin hormone levels in serum and brain were significantly higher in Group 2 than in other groups (P < 0.05). GLP-1 and serotonin levels were found to be significantly low (P < 0.05). The leptin levels in the serum of Groups 3 and 4 decreased significantly compared to Group 2 (P < 0.05).. It was found that probiotic supplementation in high-fat diet had positive effects on anorexigenic peptides. It was concluded that L. acidophilus probiotic can be recommended as a food supplement in the treatment of obesity. Topics: Animals; Diet, High-Fat; Glucagon-Like Peptide 1; Glucose; Lactobacillus acidophilus; Leptin; Neuropeptides; Obesity; Probiotics; Rats; Serotonin; Triglycerides | 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 Insulin: Glucagon Ratio and Obesity.
This communication discusses the physiology and pathology of the insulin glucagon ratio, with respect to obesity. Though high insulin levels are associated with obesity in this manuscript the authors specifically highlight its role in the causation and clinical management of obesity. It suggests that the term insulin glucagon ratio be used in preference to glucagon insulin ratio, and shares insights which may be helpful in informing future research. Topics: Glucagon; Glucagon-Like Peptide 1; Humans; Insulin; Obesity | 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 |
Maternal glucagon-like peptide-1 is positively associated with fetal growth in pregnancies complicated with obesity.
Pregnant women with obesity are more likely to deliver infants who are large for gestational age (LGA). LGA is associated with increased perinatal morbidity and risk of developing metabolic disease later in life. However, the mechanisms underpinning fetal overgrowth remain to be fully established. Here, we identified maternal, placental, and fetal factors that are associated with fetal overgrowth in pregnant women with obesity. Maternal and umbilical cord plasma and placentas were collected from women with obesity delivering infants who were LGA (n=30) or appropriate for gestational age (AGA, n=21) at term. Maternal and umbilical cord plasma analytes were measured using multiplex sandwich assay and ELISA. Insulin/mechanistic target of rapamycin (mTOR) signaling activity was determined in placental homogenates. Amino acid transporter activity was measured in isolated syncytiotrophoblast microvillous membrane (MVM) and basal membrane (BM). Glucagon-like peptide-1 receptor (GLP-1R) protein expression and signaling were measured in cultured primary human trophoblast (PHT) cells. Maternal plasma glucagon-like peptide-1 (GLP-1) was higher in LGA pregnancies and positively correlated to birthweight. Umbilical cord plasma insulin, C-peptide, and GLP-1 were increased in obese-large for gestational age (OB-LGA) infants. LGA placentas were larger but showed no change in insulin/mTOR signaling or amino acid transport activity. GLP-1R protein was expressed in the MVM isolated from human placenta. GLP-1R activation stimulated protein kinase alpha (PKA), extracellular signal-regulated kinase-1 and-2 (ERK1/2), and mTOR pathways in PHT cells. Our results suggest elevated maternal GLP-1 may drive fetal overgrowth in obese pregnant women. We speculate that maternal GLP-1 acts as a novel regulator of fetal growth by promoting placental growth and function. Topics: Diabetes, Gestational; Female; Fetal Development; Fetal Macrosomia; Glucagon-Like Peptide 1; Humans; Insulin; Obesity; Placenta; Pregnancy; TOR Serine-Threonine Kinases | 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 |
Gut microbiota-bile acids-glucagon like peptide-1 axis contributes the resistance to high fat diet-induced obesity in mice.
In human and rodents, some individuals may remain lean even when they are challenged with high calorie intake. Here, we used C57BL/6J mice to establish animal models of high-fat diet (HFD) induced obesity sensitive (DIO) mice and obesity resistant (DIR) mice. In DIR mice, improved metabolic profile through brown adipose tissue (BAT) activation was observed, while plasma unconjugated bile acids (BAs) were decreased together with increased intestine tauro-conjugated BAs (e.g., T-β-MCA). The composition of the gut flora also differs greatly between DIR and DOR. Using fecal microbiota transplants from DIR mice, HFD fed recipient mice exhibited a trend toward reduced adiposity and improved glucose tolerance, showing increased serum tauro-conjugated BAs levels. STC-1 cell experiments confirmed T-β-MCA could activate FXR/TGR5 pathway and induce the production of GLP-1, inhibiting genes that regulate the ceramide synthesis. Our results indicated that the DIR mice exhibited higher energy expenditure by activating BAT thermogenesis, which may be related to altered gut microbiota-bile acids-glucagon like peptide-1 axis. Topics: Animals; Bile Acids and Salts; Diet, High-Fat; Gastrointestinal Microbiome; Glucagon-Like Peptide 1; Humans; Mice; Mice, Inbred C57BL; Obesity | 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 |
[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 |
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 |
GLP-1 and nicotine combination therapy engages hypothalamic and mesolimbic pathways to reverse obesity.
Glucagon-like peptide-1 receptor (GLP-1R) agonists promote nicotine avoidance. Here, we show that the crosstalk between GLP-1 and nicotine extends beyond effects on nicotine self-administration and can be exploited pharmacologically to amplify the anti-obesity effects of both signals. Accordingly, combined treatment with nicotine and the GLP-1R agonist, liraglutide, inhibits food intake and increases energy expenditure to lower body weight in obese mice. Co-treatment with nicotine and liraglutide gives rise to neuronal activity in multiple brain regions, and we demonstrate that GLP-1R agonism increases excitability of hypothalamic proopiomelanocortin (POMC) neurons and dopaminergic neurons in the ventral tegmental area (VTA). Further, using a genetically encoded dopamine sensor, we reveal that liraglutide suppresses nicotine-induced dopamine release in the nucleus accumbens in freely behaving mice. These data support the pursuit of GLP-1R-based therapies for nicotine dependence and encourage further evaluation of combined treatment with GLP-1R agonists and nicotinic receptor agonists for weight loss. Topics: Animals; Dopamine; Glucagon-Like Peptide 1; Liraglutide; Mice; Nicotine; Obesity | 2023 |
Whey protein hydrolysates improve high-fat-diet-induced obesity by modulating the brain-peripheral axis of GLP-1 through inhibition of DPP-4 function in mice.
Obesity is a growing global health concern. Recent literature indicates a prominent role of glucagon-like peptide-1 (GLP-1) in glucose metabolism and food intake. The synergistic action of GLP-1 in the gut and brain is responsible for its satiety-inducing effect, suggesting that upregulation of active GLP-1 levels could be an alternative strategy to combat obesity. Dipeptidyl peptidase-4 (DPP-4) is an exopeptidase known to inactivate GLP-1, suggesting that its inhibition could be a crucial strategy for effectively extending the half-life of endogenous GLP-1. Peptides derived from partial hydrolysis of dietary proteins are gaining traction due to their inhibitory activity on DPP-4.. Whey protein hydrolysate from bovine milk (bmWPH) was produced using simulated in situ digestion, purified using RP-HPLC, and characterized for DPP-4 inhibition. The antiadipogenic and antiobesity activity of bmWPH was then studied in 3T3-L1 preadipocytes and high-fat diet-induced obesity (HFD) mice model, respectively.. The dose-dependent inhibitory effect of bmWPH on the catalytic activity of DPP-4 was observed. Additionally, bmWPH suppressed adipogenic transcription factors and DPP-4 protein levels, leading to a negative effect on preadipocyte differentiation. In an HFD mice model, co-administration of WPH for 20 weeks downregulated adipogenic transcription factors, resulting in a concomitant reduction in whole body weight and adipose tissues. Mice fed with bmWPH also showed a marked reduction in DPP-4 levels in WAT, liver, and serum. Furthermore, HFD mice fed with bmWPH exhibited increased serum and brain GLP levels, which led to a significant decrease in food intake.. In conclusion, bmWPH reduces body weight in HFD mice by suppressing appetite through GLP-1, a satiety-inducing hormone, in both the brain and peripheral circulation. This effect is achieved through modulation of both the catalytic and non-catalytic activity of DPP-4. Topics: Animals; Brain; Diet, High-Fat; Dipeptidyl-Peptidase IV Inhibitors; Glucagon-Like Peptide 1; Mice; Obesity; Protein Hydrolysates; Transcription Factors; Whey | 2023 |
Glucagon-like peptide-1 therapy in people with obesity restores natural killer cell metabolism and effector function.
People with obesity (PWO) have functionally defective natural killer (NK) cells, with a decreased capacity to produce cytokines and kill target cells, underpinned by defective cellular metabolism. It is plausible that the changes in peripheral NK cell activity are contributing to the multimorbidity in PWO, which includes an increased risk of cancer. This study investigated whether therapy with long-acting glucagon-like peptide-1 (GLP-1) analogues, which are an effective treatment for obesity, could restore NK cell functionality in PWO.. In a cohort of 20 PWO, this study investigated whether 6 months of once weekly GLP-1 therapy (semaglutide) could restore human NK cell function and metabolism using multicolor flow cytometry, enzyme-linked immunosorbent assays, and cytotoxicity assays.. These data demonstrate that PWO who received GLP-1 therapy have improved NK cell function, as measured by cytotoxicity and interferon-γ/granzyme B production. In addition, the study demonstrates increases in a CD98-mTOR-glycolysis metabolic axis, which is critical for NK cell cytokine production. Finally, it shows that the reported improvements in NK cell function appear to be independent of weight loss.. The restoration, by GLP-1 therapy, of NK cell functionality in PWO may be contributing to the overall benefits being seen with this class of medication. Topics: Cytokines; Glucagon-Like Peptide 1; Humans; Interferon-gamma; Killer Cells, Natural; Obesity | 2023 |
Glucagon-like peptide 1 receptor agonist, exendin-4, reduces alcohol-associated fatty liver disease.
Fatty liver is the earliest response to excessive ethanol consumption, which increases the susceptibility of the liver to develop advanced stage of liver disease. Our previous studies have revealed that chronic alcohol administration alters metabolic hormone levels and their functions. Of current interest to our laboratory is glucagon-like peptide 1 (GLP-1), a widely studied hormone known to reduce insulin resistance and hepatic fat accumulation in patients with metabolic-associated fatty liver disease. In this study, we examined the beneficial effects of exendin-4 (a GLP-1 receptor agonist) in an experimental rat model of ALD. Male Wistar rats were pair-fed the Lieber-DeCarli control or ethanol diet. After 4 weeks of this feeding regimen, a subset of rats in each group were intraperitoneally injected every other day with either saline or exendin-4 at a dose of 3 nmol/kg/day (total 13 doses) while still being fed their respective diet. At the end of the treatment, rats were fasted for 6 h and glucose tolerance test was conducted. The following day, the rats were euthanized, and the blood and tissue samples collected for subsequent analysis. We found that exendin-4 treatment had no significant effect on body weight gain among the experimental groups. Exendin-4-treated ethanol rats exhibited improved alcohol-induced alterations in liver/body weight and adipose/body weight ratio, serum ALT, NEFA, insulin, adiponectin and hepatic triglyceride levels. Reduction in indices of hepatic steatosis in exendin-4 treated ethanol-fed rats was attributed to improved insulin signaling and fat metabolism. These results strongly suggest that exendin-4 mitigates alcohol-associated hepatic steatosis by regulating fat metabolism. Topics: Animals; Ethanol; Exenatide; Fatty Liver, Alcoholic; Glucagon-Like Peptide 1; Insulin; Male; Non-alcoholic Fatty Liver Disease; Obesity; Rats; Rats, Wistar | 2023 |
Circulating levels of proglucagon-derived peptides are differentially regulated by the glucagon-like peptide-1 agonist liraglutide and the centrally acting naltrexone/bupropion and can predict future weight loss and metabolic improvements: A 6-month long
To investigate the changes of circulating levels of all proglucagon-derived peptides (PGDPs) in individuals with overweight or obesity receiving liraglutide (3 mg) or naltrexone/bupropion (32/360 mg), and to explore the association between induced changes in postprandial PGDP levels and body composition, as well as metabolic variables, after 3 and 6 months on treatment.. Seventeen patients with obesity or with overweight and co-morbidities, but without diabetes, were assigned to receive once-daily oral naltrexone/bupropion 32/360 mg (n = 8) or once-daily subcutaneous liraglutide 3 mg (n = 9). Participants were assessed before treatment initiation and after 3 and 6 months on treatment. At the baseline and 3-month visits, participants underwent a 3-hour mixed meal tolerance test to measure fasting and postprandial levels of PGDPs, C-peptide, hunger and satiety. Clinical and biochemical indices of metabolic function, magnetic resonance-assessed liver steatosis and ultrasound-assessed liver stiffness were measured at each visit.. Both medications improved body weight and composition, carbohydrate and lipid metabolism, and liver fat and function. Naltrexone/bupropion produced a weight-independent increase in the levels of proglucagon (P < .001) and decreases in glucagon-like peptide-2 (GLP-2), glucagon and the major proglucagon fragment (P ≤ .01), whereas liraglutide markedly upregulated total glucagon-like peptide-1 (GLP-1) levels in a weight-independent manner (P = .04), and similarly downregulated the major proglucagon fragment, GLP-2 and glucagon (P < .01). PGDP levels at the 3-month visit were positively and independently correlated with improvements in fat mass, glycaemia, lipaemia and liver function, and negatively with reductions in fat-free mass, at both the 3- and 6-month visits.. PGDP levels in response to liraglutide and naltrexone/bupropion are associated with improvements in metabolism. Our study provides support for the administration of the downregulated members of the PGDP family as replacement therapy (e.g. glucagon), in addition to the medications currently in use that induced their downregulation (e.g. GLP-1), and future studies should explore whether the addition of other PGDPs (e.g. GLP-2) could offer additional benefits. Topics: Bupropion; Glucagon; Glucagon-Like Peptide 1; Glucagon-Like Peptide 2; Glucagon-Like Peptides; Humans; Liraglutide; Naltrexone; Obesity; Overweight; Peptides; Proglucagon; Weight Loss | 2023 |
Ghrelin and glucagon-like peptide-1 according to body adiposity and glucose homeostasis.
We investigated the biological behavior of ghrelin and glucagon-like peptide-1 (GLP-1) after a standard liquid meal according to body adiposity and glucose homeostasis.. This cross-sectional study included 41 individuals (92.7% women; aged 38.3 ± 7.8 years; BMI 32.2 ± 5.5 kg/m. As expected, DOB exhibited the worst metabolic status (glucose, insulin, HOMA-IR, HbA1c) and an inflammatory status (TNF-α) at fasting, besides a more significant increase in glucose than postprandial NOB (. Time course of ghrelin and GLP-1 levels during the postprandial period was not influenced by body adiposity or glucose homeostasis. Similar behaviors occurred in controls and patients with obesity, independently of glucose homeostasis. Topics: Adiposity; Adult; Blood Glucose; Cross-Sectional Studies; Female; Ghrelin; Glucagon-Like Peptide 1; Glucose; Homeostasis; Humans; Insulin; Male; Middle Aged; Obesity | 2023 |
Impact of short and long exposure to cafeteria diet on food intake and white adipose tissue lipolysis mediated by glucagon-like peptide 1 receptor.
The modern food environment facilitates excessive calorie intake, a major driver of obesity. Glucagon-like peptide 1 (GLP1) is a neuroendocrine peptide that has been the basis for developing new pharmacotherapies against obesity. The GLP1 receptor (GLP1R) is expressed in central and peripheral tissues, and activation of GLP1R reduces food intake, increases the expression of thermogenic proteins in brown adipose tissue (BAT), and enhances lipolysis in white adipose tissue (WAT). Obesity decreases the efficiency of GLP1R agonists in reducing food intake and body weight. Still, whether palatable food intake before or during the early development of obesity reduces the effects of GLP1R agonists on food intake and adipose tissue metabolism remains undetermined. Further, whether GLP1R expressed in WAT contributes to these effects is unclear.. Food intake, expression of thermogenic BAT proteins, and WAT lipolysis were measured after central or peripheral administration of Exendin-4 (EX4), a GLP1R agonist, to mice under intermittent-short exposure to CAF diet (3 h/d for 8 days) or a longer-continuous exposure to CAF diet (24 h/d for 15 days).. During intermittent-short exposure to CAF diet (3 h/d for 8 days), third ventricle injection (ICV) and intra-peritoneal administration of EX4 reduced palatable food intake. Yet, during a longer-continuous exposure to CAF diet (24 h/d for 15 days), only ICV EX4 administration reduced food intake and body weight. However, this exposure to CAF diet blocked the increase in uncoupling protein 1 (UCP1) caused by ICV EX4 administration in mice fed control diet. Finally, GLP1R expression in WAT was minimal, and EX4 failed to increase lipolysis. Exposure to a CAF diet during the early stages of obesity reduces the effects of peripheral and central GLP1R agonists, and WAT does not express a functional GLP1 receptor. These data support that exposure to the obesogenic food environment, without the development or manifestation of obesity, can alter the response to GLP1R agonists. . Topics: Adipose Tissue, White; Animals; Body Weight; Diet; Eating; Exenatide; Glucagon-Like Peptide 1; Glucagon-Like Peptide-1 Receptor; Lipolysis; Mice; Obesity | 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 |
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 |
The potential impact of GLP-1 agonists on obstructive sleep apnoea.
Topics: Glucagon-Like Peptide 1; Humans; Obesity; Sleep Apnea, Obstructive | 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 |
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 |
Are GLP-1 agonists the answer to our obesity epidemic?
Topics: Diabetes Mellitus, Type 2; Glucagon-Like Peptide 1; Humans; Hypoglycemic Agents; Obesity | 2023 |
Computational Peptide Design Cotargeting Glucagon and Glucagon-like Peptide-1 Receptors.
Peptides are sustainable alternatives to conventional therapeutics for G protein-coupled receptor (GPCR) linked disorders, promising biocompatible and tailorable next-generation therapeutics for metabolic disorders including type-2 diabetes, as agonists of the glucagon receptor (GCGR) and the glucagon-like peptide-1 receptor (GLP-1R). However, single agonist peptides activating GLP-1R to stimulate insulin secretion also suppress obesity-linked glucagon release. Hence, bioactive peptides cotargeting GCGR and GLP-1R may remediate the blood glucose and fatty acid metabolism imbalance, tackling both diabetes and obesity to supersede current monoagonist therapy. Here, we design and model optimized peptide sequences starting from peptide sequences derived from earlier phage-displayed library screening, identifying those with predicted molecular binding profiles for dual agonism of GCGR and GLP-1R. We derive design rules from extensive molecular dynamics simulations based on peptide-receptor binding. Our newly designed coagonist peptide exhibits improved predicted coupled binding affinity for GCGR and GLP-1R relative to endogenous ligands and could in the future be tested experimentally, which may provide superior glycemic and weight loss control. Topics: Diabetes Mellitus; Glucagon; Glucagon-Like Peptide 1; Glucagon-Like Peptide-1 Receptor; Humans; Obesity; Peptides; Receptors, Glucagon | 2023 |
Red ginseng extracts ameliorate high-fat diet-induced obesity and insulin resistance by activating the intestinal TGR5-mediated bile acids signaling pathway.
Obesity has emerged as a worldwide metabolic disease, given its rapid growth in global prevalence. Red ginseng extracts (RGS), one of the traditional processed products of ginseng, show the potential to improve the metabolic phenotype of obesity. However, the RGS mechanism for regulating obesity and late insulin resistance remains to be clarified.. This study aimed to emphasize the potential use of RGS in treatment of obesity and insulin resistance (IR) and explore the underlying mechanism affecting glucose and lipid metabolism improvements.. The role of RGS was evaluated in a high-fat diet (HFD) rodent model. Glucose tolerance test (GTT) and insulin tolerance test (ITT) were performed to characterize the glucose metabolism level. The expression of lipolysis proteins and uncoupling protein-1 (UCP-1) were investigated by western blot. Glucagon-like peptide-1 (GLP-1) and apical sodium-dependent bile acid transporter (ASBT) protein expression in the intestine were determined via immunofluorescence. UPLC-Q-TOF-MS were used to detect the alterations in bile acids (BAs) levels in serum, ileum, and inguinal white adipose tissue (iWAT). In addition, intestine-specific Tgr5 knockout mice were employed to verify the efficacy of RGS in improving obesity.. RGS treatment alleviated dietary-induced dyslipidemia and IR in obese mice in a dose-dependent manner and improved glucose and insulin tolerance, and energy expenditure. RGS treatment significantly reduced lipid deposition and induced GLP-1 secretion in the intestine of wild-type mice but not in Tgr5. Our results demonstrated that RGS significantly alleviated HFD-induced obesity and insulin resistance in mice. RGS intervention improved glucose metabolism, promoted lipolysis, and energy metabolism by activating TGR5 in the intestine. In addition, we found that activating intestinal TGR5 facilitated the localization of ASBT to the plasma membrane, which ultimately promoted the transport of BAs to regulate metabolic phenotype. Topics: Animals; Bile Acids and Salts; Diet, High-Fat; Glucagon-Like Peptide 1; Glucose; Insulin Resistance; Insulins; Intestines; Mice; Mice, Inbred C57BL; Mice, Knockout; Mice, Obese; Obesity; Receptors, G-Protein-Coupled; Signal Transduction | 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 |
[Electroacupuncture improves obesity and promotes white adipose tissue browning by regulating central glucagon-like peptide-1].
To observe the effect of electroacupuncture (EA) on white adipose tissue (WAT) browning by regulating central glucagon-like peptide-1 (GLP-1), so as to explore the possible central mechanisms of EA in improving obesity.. Thirty male Wistar rats were randomly divided into normal group, model group, EA group, HM3D group, and EA+HM4D group, with 6 rats in each group. The obesity rat model was obtained by feeding with high-fat diet for 8 weeks. Adeno-associated virus combined with DREADDs was injected into bilateral nucleus of solitary tract (NTS), with rAAV-GLP-1+rAAV-4D applied to the EA+HM4D group, rAAV-GLP-1+rAAV-3D applied to the HM3D group, and rAAV-GLP-1+rAAV-GFP applied to other 3 groups. After modeling, rats in the EA and EA+HM4D groups received EA treatment at bilateral "Zusanli"(ST36), "Fenglong"(ST40), "Guanyuan"(CV4) and "Zhongwan"(CV12), with successive waves (2 Hz, 1 mA) for 10 minutes, 3 times a week, for a total of 8 weeks. Body mass of rats in each group were measured before and 2, 4, 6, and 8 weeks after intervention. Abdominal and perirenal WAT mass was weighed, serum triglyceride (TG) and total cholesterol (TC) contents were detected by using automatic analyzer, and nonestesterified fatty acid (NEFA) content was detected by using colorimetric assay kit. The morphology of abdominal WAT lipid droplets was observed by HE staining. The mRNA expressions of GLP-1 in NTS, AMPK in ventromedial nucleus of hypothalamus(VMH), UCP1 and PGC-1. Compared with the normal group, abdominal WAT lipid droplets were enlarged, body weight, serum TG, TC, NEFA contents, abdominal and perirenal WAT mass, mRNA and protein expression levels of AMPK were significantly increased(. EA can effectively promote the browning of WAT, which may be related to the activation of GLP-1 neurons in the NTS, as well as the promotion of the phosphorylation of AMPK in the VMH and up-regulation of UCP1. Topics: Adipose Tissue, White; AMP-Activated Protein Kinases; Animals; Body Weight; Electroacupuncture; Fatty Acids, Nonesterified; Glucagon-Like Peptide 1; Male; Obesity; Rats; Rats, Wistar | 2023 |
Evaluation of postprandial total triglycerides within the TIGG model for characterizing postprandial response of glucose, insulin, and GLP-1.
The TIGG model is the first model to integrate glucose and insulin regulation, incretin effect, and triglyceride (TG) response in the lipoprotein subclasses of chylomicrons and VLDL-V6. This model described the response following a high-fat meal in individuals who are lean, obese, and very obese and provided insights into the possible regulation of glucose homeostasis in the extended period following a meal. Often, total TGs are analyzed within clinical studies, instead of lipoprotein subclasses. We extended the existing TIGG model to capture the observed total TGs and determined if this model could be used to predict the postprandial TG response of chylomicron and VLDL-V6 when only total TGs are available. To assess if the lipoprotein distinction was important for the model, a second model (tTIGG) was developed using only the postprandial response in total TGs, instead of postprandial TG response in chylomicrons and VLDL-V6. The two models were compared on their predictability to characterize the postprandial response of glucose, insulin, and active GLP-1. Both models were able to characterize the postprandial TG response in individuals who are lean, obese, or very obese following a high-fat meal. The extended TIGG model resulted in a better model fit of the glucose data compared to the tTIGG model, indicating that chylomicron and VLDL-V6 provided additional information compared to total TGs. Furthermore, the expanded TIGG model was able to predict the postprandial TG response of chylomicrons and VLDL-V6 using the total TGs and could therefore be used in studies where only total TGs were collected. Topics: Blood Glucose; Chylomicrons; Glucagon-Like Peptide 1; Glucose; Humans; Insulin; Lipoproteins; Obesity; Postprandial Period; Triglycerides | 2023 |
Curcumin Compensates GLP-1 Deficiency via the Microbiota-Bile Acids Axis and Modulation in Functional Crosstalk between TGR5 and FXR in ob/ob Mice.
Glucagon-like peptide-1 (GLP-1) deficiency occurs in obesity-related pathologies due to defects in the intestinal lumen. And expanding the L-cell population has emerged as a promising avenue to elevate GLP-1 secretion to tackle metabolic disorders. Curcumin (Cur), the principal active component of spice turmeric, possesses well-established anti-obesity properties. To clarify, the study investigates whether Cur promotes GLP-1 secretion built upon the L-cell expansion.. The findings suggest that Cur may act as a natural TGR5 agonist and FXR antagonist to improve obesity by enhancing GLP-1 release from L-cell expansion via the gut microbiota-BAs-TGR5/FXR axis, and it may serve as a promising therapeutic agent to compensate obesity-related metabolic disorders. Topics: Animals; Bile Acids and Salts; Curcumin; Glucagon-Like Peptide 1; Male; Metabolic Diseases; Mice; Mice, Inbred C57BL; Microbiota; Obesity; Receptors, G-Protein-Coupled | 2023 |
The locus coeruleus contributes to the anorectic, nausea, and autonomic physiological effects of glucagon-like peptide-1.
Increasing the therapeutic potential and reducing the side effects of U.S. Food and Drug Administration-approved glucagon-like peptide-1 receptor (GLP-1R) agonists used to treat obesity require complete characterization of the central mechanisms that mediate both the food intake-suppressive and illness-like effects of GLP-1R signaling. Our studies, in the rat, demonstrate that GLP-1Rs in the locus coeruleus (LC) are pharmacologically and physiologically relevant for food intake control. Furthermore, agonism of LC GLP-1Rs induces illness-like behaviors, and antagonism of LC GLP-1Rs can attenuate GLP-1R-mediated nausea. Electrophysiological and behavioral pharmacology data support a role for LC GLP-1Rs expressed on presynaptic glutamatergic terminals in the control of feeding and malaise. Collectively, our work establishes the LC as a site of action for GLP-1 signaling and extends our understanding of the GLP-1 signaling mechanism necessary for the development of improved obesity pharmacotherapies. Topics: Animals; Appetite Depressants; Glucagon-Like Peptide 1; Glucagon-Like Peptide-1 Receptor; Locus Coeruleus; Nausea; Obesity; Rats; United States | 2023 |
Sidelined.
Svetlana Mojsov helped discover the hormone GLP-1, paving the way for blockbuster obesity drugs. Now, she's fighting for recognition. Topics: Anti-Obesity Agents; Female; Glucagon-Like Peptide 1; Humans; Obesity; Scientific Misconduct | 2023 |
Wheat Alkylresorcinols Modulate Glucose Homeostasis through Improving GLP-1 Secretion in High-Fat-Diet-Induced Obese Mice.
Wheat alkylresorcinols (ARs) consumption has been evidenced to improve obesity and its associated insulin resistance. However, the effect of ARs on glucagon-like peptide 1 (GLP-1) secretion and the underlying mechanism of action are still unclear. In this study, C57BL/6J mice were fed low-fat diet (LFD), high-fat diet (HFD), and HFD supplemented with 0.4% (w/w) ARs separately for 9 weeks. The results showed that ARs intervention significantly improved glucose homeostasis and restored the serum level of GLP-1 compared with the HFD control group. Moreover, ARs treatment alleviated HFD-induced ileal epithelium damage according to TUNEL staining, immunofluorescence, and transmission electron microscopy observation. The alleviative effect was further verified by apoptosis analysis and mitochondrial function evaluation. Furthermore, palmitic acid (PA) was administered to the intestinal secretin tumor cell line (STC-1) to clarify the protective effect of ARs on GLP-1 secretion in vitro. In consistence with the results of animal studies, ARs treatment could significantly improve GLP-1 secretion in STC-1 cells compared with PA treatment alone in a dose-dependent manner, accompanied by a reduction in apoptosis and mitochondrial dysfunction. In addition, ARs treatment notably enhanced the abundance of SCFA (short-chain fatty acid)-producing bacteria, such as Topics: Animals; Diet, High-Fat; Fatty Acids, Volatile; Gastrointestinal Hormones; Glucagon-Like Peptide 1; Glucose; Homeostasis; Mice; Mice, Inbred C57BL; Mice, Obese; Obesity; Palmitic Acid; Triticum | 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 |
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 |
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 |
An oral GLP-1 and GIP dual receptor agonist improves metabolic disorders in high fat-fed mice.
Dual activation of the glucagon-like peptide 1 (GLP-1) receptor and the glucose-dependent insulinotropic polypeptide (GIP) receptor has potential as a novel strategy for treatment of diabesity. Here, we created a hybrid peptide which we named 19W, and show that it is more stable in presence of murine plasma than exendin-4 is. In vitro studies were performed to reveal that 19W could stimulate insulin secretion from INS-1 cells in a dose-dependent manner, just like the native peptide GIP and exendin-4 do. 19W effectively evoked dose-dependent cAMP production in cells targeting both GLP-1R and GIPR. In healthy C57BL/6J mice, the single administration of 19W significantly improved glucose tolerance. When administered in combination with sodium deoxycholate (SDC), its oral hypoglycemic activity was enhanced. Pharmacokinetics studies in Wistar rats revealed that 19W was absorbed following oral uptake, while SDC increased its bioavailability. A long-term (28 days) exposure study of twice-daily oral administration to high fat-fed (HFF) mice showed that 19W significantly reduced animal food intake, body weight, fasting blood glucose, total serum cholesterol (T-CHO), non-esterified free fatty acids (NEFA), and low-density lipoprotein cholesterol (LDL-C) levels. It also significantly improved glucose tolerance and the pancreatic β/α cell ratio, and decreased the area of liver fibrosis. These results clearly demonstrate the beneficial action of this novel oral GLP-1/GIP dual receptor agonist to reduce adiposity and hyperglycemia in diabetic mice and to ameliorate liver fibrosis associated with obesity. This dual-acting peptide can be considered a good candidate for novel oral therapy to treat obesity and diabetes. Topics: Animals; Cyclic AMP; Diabetes Mellitus, Experimental; Eating; Exenatide; Gastric Inhibitory Polypeptide; Glucagon-Like Peptide 1; Hypoglycemic Agents; Incretins; Insulin; Insulin Secretion; Metabolic Diseases; Mice; Obesity; Rats; Receptors, Gastrointestinal Hormone | 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 |
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 |
Intestinal Gpr17 deficiency improves glucose metabolism by promoting GLP-1 secretion.
G protein-coupled receptors (GPCRs) in intestinal enteroendocrine cells (EECs) respond to nutritional, neural, and microbial cues and modulate the release of gut hormones. Here we show that Gpr17, an orphan GPCR, is co-expressed in glucagon-like peptide-1 (GLP-1)-expressing EECs in human and rodent intestinal epithelium. Acute genetic ablation of Gpr17 in intestinal epithelium improves glucose tolerance and glucose-stimulated insulin secretion (GSIS). Importantly, inducible knockout (iKO) mice and Gpr17 null intestinal organoids respond to glucose or lipid ingestion with increased secretion of GLP-1, but not the other incretin glucose-dependent insulinotropic polypeptide (GIP). In an in vitro EEC model, overexpression or agonism of Gpr17 reduces voltage-gated calcium currents and decreases cyclic AMP (cAMP) production, and these are two critical factors regulating GLP-1 secretion. Together, our work shows that intestinal Gpr17 signaling functions as an inhibitory pathway for GLP-1 secretion in EECs, suggesting intestinal GPR17 is a potential target for diabetes and obesity intervention. Topics: Animals; Blood Glucose; Calcium; Cell Line; Cyclic AMP; Diabetes Mellitus; Enteroendocrine Cells; Female; Gastric Inhibitory Polypeptide; Glucagon-Like Peptide 1; Glucose; Glucose Tolerance Test; HEK293 Cells; HeLa Cells; Humans; Incretins; Insulin; Insulin Secretion; Intestinal Mucosa; Male; Mice; Mice, Knockout; Nerve Tissue Proteins; Obesity; Receptors, G-Protein-Coupled; Receptors, Gastrointestinal Hormone | 2022 |
Differences in gastrointestinal hormones and appetite ratings among obesity classes.
The aim of this study was to compare gastrointestinal (GI) hormones and subjective ratings of appetite among obesity classes, and between classes of obesity and controls. Ninety-eight adult individuals with obesity, divided into class I (n = 35), II (n = 44) and III (n = 19), together with 45 controls without obesity were included in this cross-sectional analysis. Body weight/composition, and basal and postprandial (after a 600 kcal fixed breakfast) plasma concentrations of acylated ghrelin, active glucagon-like peptide 1 (GLP-1), total peptide YY (PYY), cholecystokinin (CCK) and insulin, as well as subjective ratings of hunger, fullness, desire to eat (DTE) and prospective food consumption (PFC) were measured. There were no differences in the plasma concentration of GI hormones (either basal or postprandial) among obesity classes, except for insulin. In general, obesity was associated with impaired secretion of GI hormones. Ghrelin secretion did not decline postprandially in class-III obesity. GLP-1 peak for obesity class I and II was early and lower, while class III showed no postprandial GLP-1 response. Postprandial PYY response for obesity class II and III was absent, and class III showed a delayed and shortened postprandial CCK response. Obesity class II and III had greater basal insulin concentration compared to controls and postprandial insulin was greater in obesity class III versus class II, class I and controls. No differences were found for appetite ratings among obesity classes. In conclusion, obesity is characterized by impaired secretion of GI hormones, with reduced postprandial satiety, particularly in individuals with obesity class III. This abnormal pattern may lead to overeating. Topics: Adult; Appetite; Cholecystokinin; Cross-Sectional Studies; Gastrointestinal Hormones; Ghrelin; Glucagon-Like Peptide 1; Humans; Insulin; Obesity; Peptide YY; Postprandial Period | 2022 |
Steps to redressing an imbalance: GLP-1 analogues for obesity in east Asia.
Topics: Asia, Eastern; Glucagon-Like Peptide 1; Humans; Hypoglycemic Agents; Obesity | 2022 |
Gut Microbiota Regulate Pancreatic Growth, Exocrine Function, and Gut Hormones.
Growing evidence indicates an important link between gut microbiota, obesity, and metabolic syndrome. Alterations in exocrine pancreatic function are also widely present in patients with diabetes and obesity. To examine this interaction, C57BL/6J mice were fed a chow diet, a high-fat diet (HFD), or an HFD plus oral vancomycin or metronidazole to modify the gut microbiome. HFD alone leads to a 40% increase in pancreas weight, decreased glucagon-like peptide 1 and peptide YY levels, and increased glucose-dependent insulinotropic peptide in the plasma. Quantitative proteomics identified 138 host proteins in fecal samples of these mice, of which 32 were significantly changed by the HFD. The most significant of these were the pancreatic enzymes. These changes in amylase and elastase were reversed by antibiotic treatment. These alterations could be reproduced by transferring gut microbiota from donor C57BL/6J mice to germ-free mice. By contrast, antibiotics had no effect on pancreatic size or exocrine function in C57BL/6J mice fed the chow diet. Further, 1 week vancomycin administration significantly increased amylase and elastase levels in obese men with prediabetes. Thus, the alterations in gut microbiota in obesity can alter pancreatic growth, exocrine function, and gut endocrine function and may contribute to the alterations observed in patients with obesity and diabetes. Topics: Amylases; Animals; Diet, High-Fat; Gastrointestinal Microbiome; Glucagon-Like Peptide 1; Humans; Mice; Mice, Inbred C57BL; Obesity; Pancreas; Pancreatic Elastase; Vancomycin | 2022 |
Preclinical evaluation of a protracted GLP-1/glucagon receptor co-agonist: Translational difficulties and pitfalls.
During recent years combining GLP-1 and glucagon receptor agonism with the purpose of achieving superior weight loss and metabolic control compared to GLP-1 alone has received much attention. The superior efficacy has been shown by several in preclinical models but has been difficult to reproduce in humans. In this paper, we present the pre-clinical evaluation of NN1177, a long-acting GLP-1/glucagon receptor co-agonist previously tested in clinical trials. To further investigate the contribution from the respective receptors, two other co-agonists (NN1151, NN1359) with different GLP-1-to-glucagon receptor ratios were evaluated in parallel. In the process of characterizing NN1177, species differences and pitfalls in traditional pre-clinical evaluation methods were identified, highlighting the translational challenges in predicting the optimal receptor balance in humans. In diet-induced obese (DIO) mice, NN1177 induced a dose-dependent body weight loss, primarily due to loss of fat mass, and improvement in glucose tolerance. In DIO rats, NN1177 induced a comparable total body weight reduction, which was in contrast mainly caused by loss of lean mass, and glucose tolerance was impaired. Furthermore, despite long half-lives of the three co-agonists, glucose control during steady state was seen to depend on compound exposure at time of evaluation. When evaluated at higher compound exposure, glucose tolerance was similarly improved for all three co-agonists, independent of receptor balance. However, at lower compound exposure, glucose tolerance was gradually impaired with higher glucagon receptor preference. In addition, glucose tolerance was found to depend on study duration where the effect of glucagon on glucose control became more evident with time. To conclude, the pharmacodynamic effects at a given GLP-1-to-glucagon ratio differs between species, depends on compound exposure and study length, complicating the identification of an optimally balanced clinical candidate. The present findings could partly explain the low number of clinical successes for this dual agonism. Topics: Animals; Blood Glucose; Glucagon; Glucagon-Like Peptide 1; Glucagon-Like Peptide-1 Receptor; Mice; Mice, Obese; Obesity; Rats; Receptors, Glucagon; Weight Loss | 2022 |
The Association between Peptide Hormones with Obesity and Insulin Resistance Markers in Lean and Obese Individuals in the United Arab Emirates.
Peptide hormones play a crucial role in body weight and glucose homeostasis. In this study, we aimed to explore this association and recruited 43 obese and 31 age- and sex-matched lean participants. We assessed their body mass index (BMI), waist circumference (WC), waist-to-height ratio (WtHR), percentage body fat (PBF), fasting blood levels of peptide hormones (GLP-1, GLP-2, insulin, leptin, ghrelin, CCK, and PYY), fasting blood sugar (FBS), and Homeostatic Model Assessment of Insulin Resistance (HOMA-IR). We tested the associations between peptide hormones and markers of obesity and insulin resistance (IR) by using the Independent-Samples Topics: Adult; Body Mass Index; Glucagon-Like Peptide 1; Humans; Insulin Resistance; Obesity; United Arab Emirates | 2022 |
Impact of Obesity on Postprandial Triglyceride Contribution to Glucose Homeostasis, Assessed with a Semimechanistic Model.
The integrated glucose-insulin model is a semimechanistic model describing glucose and insulin after a glucose challenge. Similarly, a semiphysiologic model of the postprandial triglyceride (TG) response in chylomicrons and VLDL-V6 was recently published. We have developed the triglyceride-insulin-glucose-GLP-1 (TIGG) model by integrating these models and active GLP-1. The aim was to characterize, using the TIGG model, the postprandial response over 13 hours following a high-fat meal in 3 study populations based on body mass index categories: lean, obese, and very obese. Differential glucose and lipid regulation were observed between the lean population and obese or very obese populations. A population comparison revealed further that fasting glucose and insulin were elevated in obese and very obese when compared with lean; and euglycemia was achieved at different times postmeal between the obese and very obese populations. Postprandial insulin was incrementally elevated in the obese and very obese populations compared with lean. Postprandial chylomicrons TGs were similar across populations, whereas the postprandial TGs in VLDL-V6 were increased in the obese and very obese populations compared with lean. Postprandial active GLP-1 was diminished in the very obese population compared with lean or obese. The TIGG model described the response following a high-fat meal in individuals who are lean, obese, and very obese and provided insight into the possible regulation of glucose homeostasis in the extended period after the meal by utilizing lipids. The TIGG-model is the first model to integrate glucose and insulin regulation, incretin effect, and postprandial TGs response in chylomicrons and VLDL-V6. Topics: Blood Glucose; Chylomicrons; Glucagon-Like Peptide 1; Glucose; Homeostasis; Humans; Insulin; Obesity; Postprandial Period; Triglycerides | 2022 |
Targeting the Enteroendocrine System for Treatment of Obesity.
Mimetics of the anorexigenic gut hormone glucagon-like peptide 1 (GLP-1) were originally developed as insulinotropic anti-diabetic drugs but also evoke significant weight loss, leading to their recent approval as obesity therapeutics. Co-activation of receptors for GLP-1 and other gut hormones which reduce food intake - peptide YY (PYY Topics: Gastric Inhibitory Polypeptide; Gastrointestinal Hormones; Glucagon-Like Peptide 1; Humans; Obesity; Peptide YY; Weight Loss | 2022 |
The Enteroendocrine System in Obesity.
The enteroendocrine system coordinates the physiological response to food intake by regulating rates of digestion, nutrient absorption, insulin secretion, satiation and satiety. Gut hormones with important anorexigenic and/or insulinotropic roles include glucagon-like peptide 1 (GLP-1), peptide YY (PYY Topics: Cholecystokinin; Gastric Inhibitory Polypeptide; Glucagon-Like Peptide 1; Humans; Obesity; Peptide YY | 2022 |
Effects of ALT-801, a GLP-1 and glucagon receptor dual agonist, in a translational mouse model of non-alcoholic steatohepatitis.
Body weight loss of ≥ 10% improves the metabolic derangements and liver disease in the majority of non-alcoholic steatohepatitis (NASH) patients, suggesting metabolic modulators may be effective in controlling disease. The pharmacodynamics of ALT-801, a GLP-1/glucagon receptor dual agonist optimized for NASH and weight loss, were compared to semaglutide (GLP-1 receptor agonist) and elafibranor (peroxisome proliferator-activated receptor, PPAR-α/δ, agonist) in a biopsy-confirmed, diet-induced obese (DIO) mouse model of NASH (DIO-NASH). Male C57BL/6J mice were fed Amylin Liver NASH (AMLN) diet for 32 weeks. Animals with biopsy-confirmed steatosis and fibrosis received ALT-801, semaglutide, elafibranor, or vehicle daily for 12 weeks while maintained on the AMLN diet. Study endpoints included body and liver weight, liver and plasma total cholesterol and triglycerides, plasma aminotransferases, histological analysis of liver steatosis, inflammation (galectin-3) and fibrosis (collagen type 1 alpha 1), and evaluation of individual animal changes in composite Non-alcoholic Fatty Liver Disease Activity Score (NAS), and fibrosis stage. ALT-801 demonstrated significant reductions in body weight (approx. 25%), plasma aminotransferases, plasma total cholesterol and liver triglycerides/total cholesterol in conjunction with improved liver steatosis, with greater reductions (p < 0.05) compared to semaglutide and elafibranor. ALT-801 significantly reduced the inflammation marker galectin-3 and the fibrosis marker collagen type 1 alpha 1 vs. vehicle (p < 0.05), with ALT-801 producing greater reductions in galectin-3 vs. elafibranor (p < 0.05). Importantly, all animals treated with ALT-801 significantly improved composite NAS compared to the active controls. This study provides evidence for a potential role for ALT-801 in the therapeutic treatment of NASH. Topics: Animals; Cholesterol; Collagen; Disease Models, Animal; Galectin 3; Glucagon; Glucagon-Like Peptide 1; Inflammation; Interleukin-2; Liver; Liver Cirrhosis; Male; Mice; Mice, Inbred C57BL; Mice, Obese; Non-alcoholic Fatty Liver Disease; Obesity; Receptors, Antigen, T-Cell; Receptors, Glucagon; Recombinant Fusion Proteins; Transaminases; Triglycerides | 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 |
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 |
D-Allulose cooperates with glucagon-like peptide-1 and activates proopiomelanocortin neurons in the arcuate nucleus and central injection inhibits feeding in mice.
A rare sugar D-Allulose has sweetness without calorie. Previous studies have shown that D-Allulose improves glucose and energy metabolism and ameliorates obesity. However, underlying mechanisms remain elusive. This study explored the effect of central injection of D-Allulose on feeding behavior in mice. We also examined direct effects of D-Allulose on the neurons in the hypothalamic arcuate nucleus (ARC) that regulate feeding, including the anorexigenic glucagon-like peptide-1 (GLP-1)-responsive neurons and proopiomelanocortin (POMC) neurons. Single neurons were isolated from ARC and cytosolic Ca Topics: Animals; Arcuate Nucleus of Hypothalamus; Fructose; Glucagon-Like Peptide 1; Mice; Neurons; Obesity; Pro-Opiomelanocortin | 2022 |
Gut Hormones Secretion across Clusters of Metabolic Syndrome in Prepubertal Children with Obesity.
Metabolic Syndrome (MetS) represents a common dysmetabolic state in children with obesity. Although data in youth show a role of gut hormones (GH) in the risk of developing MetS, no data are available during the prepubertal age, especially across clusters of MetS.. We characterized components of MetS and changes in GH concentrations in 90 prepubertal children with obesity compared to 30 healthy age- and gender-matched peers. Children with obesity were divided into three groups according to the number of the components of MetS (group 1: 30 obese without components of MetS; group 2: 30 obese with 1 component of MetS; group 3: 30 obese with 2 or more components of MetS). Anthropometric parameters, blood pressure (BP), fasting insulin and glycemia, lipid profile, transaminases, and GH concentration were determined. Differences across the groups were evaluated by the Kruskal-Wallis test and post hoc analysis by Mann-Whitney test.. Fasting glycemia and insulin, HOMA-IR, triglycerides, and BP progressively increased and high-density lipoprotein progressively decreased across the groups of children with obesity compared to controls, showing worse values in group 3. GLP-1 and ghrelin values progressively decreased and obestatin progressively increased. The more components of the MetS were present, the further GH concentrations deviated from standard values.. Components of MetS and GH concentrations are impaired in prepubertal children with obesity compared to controls. The close association between progressive alterations in GH levels and increasing number of components of the MetS might indicate a role of these hormones in the determination of metabolic risk. Topics: Adolescent; Blood Glucose; Body Mass Index; Child; Ghrelin; Glucagon-Like Peptide 1; Humans; Insulin; Insulin Resistance; Lipoproteins, HDL; Metabolic Syndrome; Obesity; Transaminases; Triglycerides | 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 |
Association between CLOCK 3111 T/C polymorphism with ghrelin, GLP-1, food timing, sleep and chronotype in overweight and obese Iranian adults.
Circadian Locomotor Output Cycles Kaput (CLOCK), an essential element of the positive regulatory arm in the human biological clock, is involved in metabolic regulation. The aim was to investigate the behavioral (sleep duration, food timing, dietary intake, appetite and chronobiologic characteristics) and hormonal (plasma ghrelin and Glucagon-like peptide-1 concentrations) factors that could explain the previously reported association between the CLOCK 3111 T/C SNP and obesity.. This cross-sectional study included 403 subjects, overweight and/or obesity, aged 20- 50 years from Iran. The CLOCK rs1801260 data were measured by the PCR-RFLP method. Dietary intake, food timing, sleep duration, appetite and Chrono-type were assessed using validated questionnaires. Ghrelin and GLP-1 were measured by ELIZA in plasma samples. Participants were also divided into three groups based on BMI. Logistic regression models and general linear regression models were used to assess the association between CLOCK genotype and study parameters. Univariate linear regression models were used to assess the interaction between CLOCK and VAS, Food timing, chronotype and sleep on food intakes.. After controlling for confounding factors, there was a significant difference between genotypes for physical activity (P = 0.001), waist circumference (P˂0.05), BMI (˂0.01), weight (P = 0.001), GLP-1 (P = 0.02), ghrelin (P = 0.04), appetite (P˂0.001), chronotype (P˂0.001), sleep (P˂0.001), food timing (P˂0.001), energy (P˂0.05), carbohydrate (P˂0.05) and fat intake (P˂0.001). Our findings also show that people with the minor allele C who ate lunch after 3 PM and breakfast after 9 AM are more prone to obesity (P˂0.05). furthermore, there was significant interactions between C allele carrier group and high appetite on fat intake (Pinteraction = 0.041), eat lunch after 3 PM on energy intake (Pinteraction = 0.039) and morning type on fat intake (Pinteraction = 0.021).. Sleep reduction, changes in ghrelin and GLP-1 levels, changes in eating behaviors and evening preference that characterized CLOCK 3111C can all contribute to obesity. Furthermore, the data demonstrate a clear relationship between the timing of food intake and obesity. Our results support the hypothesis that the influence of the CLOCK gene may extend to a wide range of variables related to human behaviors. Topics: Adult; Circadian Rhythm; Cross-Sectional Studies; Ghrelin; Glucagon-Like Peptide 1; Humans; Iran; Obesity; Overweight; Sleep | 2022 |
Food insecurity is associated with higher respiratory quotient and lower glucagon-like peptide 1.
Food insecurity is known to be associated with obesity, but its association with physiological measures is unclear. Therefore, it was hypothesized that, compared with food-secure individuals, those with food insecurity would have higher 24-hour energy expenditure (EE [kilocalories per day]) and 24-hour respiratory quotient (RQ [ratio]). Subsequently, hormones involved in appetite regulation, substrate oxidation, and EE were explored.. A total of 113 healthy participants without diabetes (75 men; mean [SD], age 40 [12] years; BMI 30 [8] kg/m. Compared with individuals with food security, participants with food insecurity had no difference in 24-hour EE. However, they had higher carbohydrate oxidation rates (p = 0.03) and lower lipid oxidation rates (p = 0.02), resulting in higher 24-hour RQ (p < 0.01). They also had lower fasting glucagon-like peptide 1 (p = 0.03) concentrations.. Food insecurity is associated with higher 24-hour RQ and lower fasting glucagon-like peptide 1 concentrations, metabolic and hormonal differences previously shown to drive greater calorie intake in the setting of unrestricted food availability. These findings therefore provide new insight into the paradoxical link between restricted food access and increased adiposity. Topics: Adult; Energy Intake; Energy Metabolism; Food Insecurity; Glucagon-Like Peptide 1; Humans; Male; Obesity | 2022 |
Obesity-related vascular dysfunction persists after weight loss and is associated with decreased vascular glucagon-like peptide receptor in female rats.
Topics: Animals; Body Weight; Female; Glucagon-Like Peptide 1; Glucagon-Like Peptide Receptors; Glucagon-Like Peptide-1 Receptor; Obesity; Proto-Oncogene Proteins c-akt; Rats; Rats, Wistar; Weight Loss | 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 |
Structurally-engineered fatty acid 1024 (SEFA-1024) improves diet-induced obesity, insulin resistance, and fatty liver disease.
Obesity is a global epidemic that drives morbidity and mortality through cardiovascular disease, diabetes, and non-alcoholic fatty liver disease (NAFLD). No definitive therapy has been approved to improve glycemic control and treat NAFLD in obese patients. Here, we investigated a semi-synthetic, long chain, structurally-engineered fatty acid-1024 (SEFA-1024), as a treatment for obesity-induced hyperglycemia, insulin-resistance, and fatty liver disease in rodent models. A single dose of SEFA-1024 was administered to evaluate glucose tolerance and active glucagon-like peptide 1 (GLP-1) in lean rats in the presence and absence of a DPP-4 inhibitor. The effects of SEFA-1024 on weight loss and glycemic control were assessed in genetic (ob/ob) and environmental (high-fat diet) murine models of obesity. Liver histology, serum liver enzymes, liver lipidomics, and hepatic gene expression were also assessed in the high-fat diet murine model. SEFA-1024 reversed obesity-associated insulin resistance and improved glycemic control. SEFA-1024 increased active GLP-1. In a long-term model of diet-induced obesity, SEFA-1024 reversed excessive weight gain, hepatic steatosis, elevated liver enzymes, hepatic lipotoxicity, and promoted fatty acid metabolism. SEFA-1024 is an enterohepatic-targeted, eicosapentaenoic acid derivative that reverses obesity-induced dysregulated glucose metabolism and hepatic lipotoxicity in genetic and dietary rodent models of obesity. The mechanism by which SEFA-1024 works may include increasing aGLP-1, promoting fatty acid oxidation, and inhibiting hepatic triglyceride formation. SEFA-1024 may serve as a potential treatment for obesity-related diabetes and NAFLD. Topics: Animals; Diabetes Mellitus; Diet, High-Fat; Fatty Acids; Glucagon-Like Peptide 1; Insulin Resistance; Lipid Metabolism; Liver; Mice; Mice, Inbred C57BL; Non-alcoholic Fatty Liver Disease; Obesity; Rats | 2022 |
Breaking down a gut-to-brain circuit that prevents malabsorption.
The ileal brake is an important reflex that ensures proper absorption of nutrients. This involves intestinal GLP-1 release, which recruits an enteric-sympathetic-spinal pathway to inhibit gastric motility and appetite. This visceral alarm system could be targeted to treat obesity and gastrointestinal dysfunction. Topics: Brain; Gastrointestinal Diseases; Glucagon-Like Peptide 1; Humans; Ileum; Obesity | 2022 |
[Benefits of telematic monitoring for weight loss in overweight and obese patients in times of confinement].
Introduction: the pandemic originated by SARS-Cov-2 in 2019 led to eating habits and physical exercise changes due to home confinement measures. The follow-up of patients in treatment for weight loss through telematic consultation could be a useful tool to prevent treatment failure. Objective: to describe the evolution of anthropometric parameters of patients under follow-up for weight loss through telematic consultation. Methods: a two-stage prospective study (before and after confinement) with a telematic intervention in adult patients under regular follow-up for overweight and obesity. Demographic variables and body composition parameters were analyzed by bioimpendance. In addition, the differences in the presence of drug treatment with GLP-1 hormone (liraglutide or semaglutide) adjuvants were also analyzed. The variables were studied using Wilcoxon's test, Mann-Whitney U-test, and Spearman's correlation. Significance was considered for p ≤ 0.05. Results: a total of 97 patients were included, before confinement 42.3 % were overweight (BMI < 30 kg/m2), 36.1 % were obese grade I (BMI = 30-34.9 kg/m2), 16.4 % were obese grade II (BMI = 35-39.9 kg/m2), and 5.2 % had BMI > 40 kg/m2. In all, 30.9 % had prediabetes and 9.3 % had type-2 diabetes. Between both consultations, 81.4 % of patients lost 4.2 ± 3.4 % of their weight, with a significant mean decrease in fat mass of 3.16 ± 4.4 kg. The group on pharmacological treatment with GLP-1 hormone analogs presented a significantly higher average fat loss without significant loss of skeletal muscle mass. Conclusions: telematic monitoring seems to be a useful tool to prevent weight gain in patients with restricted mobility. A telematic intervention that contains dietary advice and exercise, as a reinforcement to hypocaloric diet, helps to achieve weight loss with a predominant fat component. The presence of drug treatment with GLP-1 hormone analogues appears to significantly help maintain skeletal muscle mass during weight loss.. Introducción: la pandemia originada en 2019 por el SARS-CoV-2 supuso un cambio en los hábitos de alimentación y ejercicio físico por causa de las medidas de confinamiento domiciliario. El seguimiento de pacientes en tratamiento de pérdida de peso mediante una consulta telemática podría ser una herramienta útil para prevenir el fracaso terapéutico. Objetivo: describir la evolución de los parámetros antropométricos de pacientes en seguimiento para pérdida de peso mediante una consulta telemática. Métodos: estudio prospectivo en 2 tiempos (antes y después del confinamiento) de una intervención telemática sobre pacientes adultos en seguimiento habitual por sobrepeso y obesidad. Se analizaron las variables demográficas y los parámetros de composición corporal mediante bioimpendancia. Además se analizaron las diferencias en cuanto a presencia de tratamiento farmacológico adyuvante del tipo de los análogos de la hormona GLP1 (liraglutida o semaglutida). Las variables se estudiaron mediante la prueba de Wilcoxon, la U de Mann-Whitney y la correlación de Spearman. Se consideró la significación si p ≤ 0,05. Resultados: se incluyeron 97 pacientes. Antes del confinamiento, el 42,3 % presentaban sobrepeso (IMC < 30 kg/m2), el 36,1 % tenían obesidad de grado I (IMC = 30-34,9 kg/m2), el 16,4 % la tenían de grado II (IMC = 35-39,9 kg/m2) y el 5,2 % tenían un IMC > 40 kg/m2. El 30,9 % presentaban prediabetes y el 9,3 % tenían diabetes de tipo 2. Entre ambas visitas presenciales, el 81,4 % de los pacientes perdieron un 4,2 ± 3,4 % del peso, con una disminución media significativa de la masa grasa de 3,16 ± 4,4 kg. El grupo en tratamiento farmacológico con análogos de la hormona GLP-1 presentó una pérdida de masa grasa media significativamente superior sin pérdida de masa muscular esquelética significativa. Conclusiones: el seguimiento telemático parece una herramienta útil para prevenir la ganancia de peso en los pacientes con restricción de la movilidad. Una intervención telemática que contenga consejo dietético y ejercicio como refuerzo de la dieta hipocalórica ayuda a conseguir perder peso, predominando el componente graso. La presencia de un tratamiento farmacológico con análogos de la hormona GLP-1 parece ayudar significativamente al mantenimiento de la masa muscular esquelética durante la pérdida de peso. Topics: Adult; Body Mass Index; COVID-19; Diet, Reducing; Glucagon-Like Peptide 1; Humans; Hypoglycemic Agents; Obesity; Overweight; Prospective Studies; SARS-CoV-2; Weight Loss | 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 |
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 |
Roux-en-Y gastric bypass alters intestinal glucose transport in the obese Zucker rat.
The gastrointestinal tract plays a major role in regulating glucose homeostasis and gut endocrine function. The current study examines the effects of Roux-en-Y gastric bypass (RYGB) on intestinal GLP-1, glucose transporter expression and function in the obese Zucker rat (ZR).. Two groups of ZRs were studied: RYGB and sham surgery pair-fed (PF) fed rats. Body weight and food intake were measured daily. On post-operative day (POD) 21, an oral glucose test (OGT) was performed, basal and 30-minute plasma, portal venous glucose and glucagon-like peptide-1 (GLP-1) levels were measured. In separate ZRs, the biliopancreatic, Roux limb (Roux) and common channel (CC) intestinal segments were harvested on POD 21.. Body weight was decreased in the RYGB group. Basal and 30-minute OGT plasma and portal glucose levels were decreased after RYGB. Basal plasma GLP-1 levels were similar, while a 4.5-fold increase in GLP-1 level was observed in 30-minute after RYGB (vs. PF). The increase in basal and 30-minute portal venous GLP-1 levels after RYGB were accompanied by increased mRNA expressions of proglucagon and PC 1/3, GPR119 protein in the Roux and CC segments. mRNA and protein levels of FFAR2/3 were increased in Roux segment. RYGB decreased brush border glucose transport, transporter proteins (SGLT1 and GLUT2) and mRNA levels of Tas1R1/Tas1R3 and α-gustducin in the Roux and CC segments.. Reductions in intestinal glucose transport and enhanced post-prandial GLP-1 release were associated with increases in GRP119 and FFAR2/3 after RYGB in the ZR model. Post-RYGB reductions in the regulation of intestinal glucose transport and L cell receptors regulating GLP-1 secretion represent potential mechanisms for improved glycemic control. Topics: Animals; Body Weight; Gastric Bypass; Glucagon-Like Peptide 1; Glucose; Obesity; Rats; Rats, Zucker; RNA, Messenger | 2022 |
Association and interaction of the MC4R rs17782313 polymorphism with plasma ghrelin, GLP-1, cortisol, food intake and eating behaviors in overweight/obese Iranian adults.
Recent studies have shown that obesity is largely influenced by heredity and created by the interactions between several genes and environmental and behavioral factors. This study aimed to examine association between variant rs17782313 near melanocortin-4 receptor (MC4R) gene and behavioral and hormonal factors then evaluated interactions between variant MC4R rs17782313 with behavioral and hormonal factors on obesity.. This cross-sectional study included 403 subjects, overweight and/or obesity, aged 20-50 years from Iran. The MC4R rs17782313 data were measured by the PCR-RFLP method. Dietary intake, physical activity, stress, anxiety, depression, appetite and emotional eating were assessed by using validated questionnaires. Ghrelin, glucagon-like peptide-1 and cortisol were measured by radioimmunoassay in plasma samples. Participants were also divided into three groups based on rs17782313 genotype and BMI.. After adjustment for age, gender, energy intake and PA, significant associations were observed between food intake, appetite, emotional eating, stress and physical activity with MC4R rs17782313 (p ˂0.05). Also, significant interactions were observed between fat intake (p-interaction = 0.002), protein intake (p-interaction = 0.01), energy intake (p-interaction = 0.01), emotional eating (p-interaction = 0.02), appetite (p-interaction = 0.04), stress (p-interaction = 0.04), ghrelin (p-interaction = 0.03), cortisol (p-interaction = 0.04) and physical activity (p-interaction = 0.04) and MC4R rs17782313 in terms of BMI.. Interactions between the CC genotype and high intakes of fat and energy, emotional eating, high appetite, and too much stress with high levels of cortisol and ghrelin probably can have an effect on BMI in overweight/obese subjects. Topics: Adult; Cross-Sectional Studies; Eating; Feeding Behavior; Ghrelin; Glucagon-Like Peptide 1; Humans; Hydrocortisone; Iran; Obesity; Overweight; Receptor, Melanocortin, Type 4; Transcription Factors | 2022 |
Differential effects of RYGB surgery and best medical treatment for obesity-diabetes on intestinal and islet adaptations in obese-diabetic ZDSD rats.
Modification of gut-islet secretions after Roux-En-Y gastric bypass (RYBG) surgery contributes to its metabolic and anti-diabetic benefits. However, there is limited knowledge on tissue-specific hormone distribution post-RYGB surgery and how this compares with best medical treatment (BMT). In the present study, pancreatic and ileal tissues were excised from male Zucker-Diabetic Sprague Dawley (ZDSD) rats 8-weeks after RYGB, BMT (daily oral dosing with metformin 300mg/kg, fenofibrate 100mg/kg, ramipril 1mg/kg, rosuvastatin 10mg/kg and subcutaneous liraglutide 0.2mg/kg) or sham operation (laparotomy). Insulin, glucagon, somatostatin, PYY, GLP-1 and GIP expression patterns were assessed using immunocytochemistry and analyzed using ImageJ. After RYGB and BMT, body weight and plasma glucose were decreased. Intestinal morphometry was unaltered by RYGB, but crypt depth was decreased by BMT. Intestinal PYY cells were increased by both interventions. GLP-1- and GIP-cell counts were unchanged by RYGB but BMT increased ileal GLP-1-cells and decreased those expressing GIP. The intestinal contents of PYY and GLP-1 were significantly enhanced by RYGB, whereas BMT decreased ileal GLP-1. No changes of islet and beta-cell area or proliferation were observed, but the extent of beta-cell apoptosis and islet integrity calculated using circularity index were improved by both treatments. Significantly decreased islet alpha-cell areas were observed in both groups, while beta- and PYY-cell areas were unchanged. RYGB also induced a decrease in islet delta-cell area. PYY and GLP-1 colocalization with glucagon in islets was significantly decreased in both groups, while co-staining of PYY with glucagon was decreased and that with somatostatin increased. These data characterize significant cellular islet and intestinal adaptations following RYGB and BMT associated with amelioration of obesity-diabetes in ZDSD rats. The differential responses observed and particularly those within islets, may provide important clues to the unique ability of RYGB to cause diabetes remission. Topics: Animals; Blood Glucose; Diabetes Mellitus; Fenofibrate; Gastric Bypass; Glucagon; Glucagon-Like Peptide 1; Insulin; Liraglutide; Male; Metformin; Obesity; Ramipril; Rats; Rats, Sprague-Dawley; Rats, Zucker; Rosuvastatin Calcium; Somatostatin | 2022 |
Oral berberine ameliorates high-fat diet-induced obesity by activating TAS2Rs in tuft and endocrine cells in the gut.
Although oral berberine, a natural compound extracted from the Chinese herbal medicine curcumin, has low bioavailability, it is still effective in suppressing obesity; however, the underlying mechanism is unclear. Berberine can bind to bitter-taste receptors (TAS2Rs) in intestinal endocrine secretin tumor (STC-1) cells to promote glucagon-like peptide-1 (GLP-1) secretion. Notably, TAS2Rs also exist in the tuft cells of the gut. Therefore, this study aimed to explore whether the beneficial effect of oral berberine on obesity is dependent on bitter-taste signaling in the tuft cells of the gut.. Standard chow diet (SCD) or high-fat diet (HFD) was administered to C57BL/6 mice, with or without berberine (100 mg/kg, 200 mg/kg, p. o.). The PLCβ2 inhibitor U73122 was used to verify whether the anti-obesity effect of berberine was dependent on the bitter-taste signaling pathway. In this study, we observed that the oral administration of berberine alleviated HFD-induced obesity in mice that U73122 partially inhibited. Both in vivo and ex vivo, berberine upregulated the release of GLP-1, promoted the proliferation of tuft cells and secretion of IL-25 in obesity via the TAS2R signaling pathway.. Oral berberine ameliorated HFD-induced obesity through the TAS2R-IL-25 signaling pathway in tuft cells in the gut.. We identified and functionally characterized the TAS2Rs and Gα-gustducin/Gβ1γ13 signaling pathway utilized by tuft cells in response to oral berberine in obese mice and proposed a new mechanism underlying the anti-obesity effect of berberine. Topics: Animals; Berberine; Diet, High-Fat; Endocrine Cells; Glucagon-Like Peptide 1; Mice; Mice, Inbred C57BL; Mice, Obese; Obesity; Receptors, G-Protein-Coupled | 2022 |
BI 456906: Discovery and preclinical pharmacology of a novel GCGR/GLP-1R dual agonist with robust anti-obesity efficacy.
Obesity and its associated comorbidities represent a global health challenge with a need for well-tolerated, effective, and mechanistically diverse pharmaceutical interventions. Oxyntomodulin is a gut peptide that activates the glucagon receptor (GCGR) and glucagon-like peptide-1 receptor (GLP-1R) and reduces bodyweight by increasing energy expenditure and reducing energy intake in humans. Here we describe the pharmacological profile of the novel glucagon receptor (GCGR)/GLP-1 receptor (GLP-1R) dual agonist BI 456906.. BI 456906 was characterized using cell-based in vitro assays to determine functional agonism. In vivo pharmacological studies were performed using acute and subchronic dosing regimens to demonstrate target engagement for the GCGR and GLP-1R, and weight lowering efficacy.. BI 456906 is a potent, acylated peptide containing a C18 fatty acid as a half-life extending principle to support once-weekly dosing in humans. Pharmacological doses of BI 456906 provided greater bodyweight reductions in mice compared with maximally effective doses of the GLP-1R agonist semaglutide. BI 456906's superior efficacy is the consequence of increased energy expenditure and reduced food intake. Engagement of both receptors in vivo was demonstrated via glucose tolerance, food intake, and gastric emptying tests for the GLP-1R, and liver nicotinamide N-methyltransferase mRNA expression and circulating biomarkers (amino acids, fibroblast growth factor-21) for the GCGR. The dual activity of BI 456906 at the GLP-1R and GCGR was supported using GLP-1R knockout and transgenic reporter mice, and an ex vivo bioactivity assay.. BI 456906 is a potent GCGR/GLP-1R dual agonist with robust anti-obesity efficacy achieved by increasing energy expenditure and decreasing food intake. Topics: Animals; Glucagon-Like Peptide 1; Glucagon-Like Peptide-1 Receptor; Humans; Mice; Obesity; Oxyntomodulin; Peptides; Receptors, Glucagon | 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 |
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 |
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 |
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 |
Neurotensin secretion after Roux-en-Y gastric bypass, sleeve gastrectomy, and truncal vagotomy with pyloroplasty.
Neurotensin (NT) is released from enteroendocrine cells and lowers food intake in rodents. We evaluated postprandial NT secretion in humans after surgeries associated with accelerated small intestinal nutrient delivery, and after Roux-en-Y gastric bypass (RYGB) when glucagon-like peptide-1 (GLP-1) signalling and dipeptidyl peptidase 4 (DPP-4) were inhibited, and during pharmacological treatments influencing entero-pancreatic functions.. We measured NT concentrations in plasma from meal studies: (I) after truncal vagotomy with pyloroplasty (TVP), cardia resection +TVP (CTVP), and matched controls (n = 10); (II) after RYGB, sleeve gastrectomy (SG), and in matched controls (n = 12); (III) after RYGB (n = 11) with antagonism of GLP-1 signalling using exendin(9-39) and DPP-4 inhibition using sitagliptin; (IV) after RYGB (n = 11) during a run-in period and subsequent treatment with, sitagliptin, liraglutide (GLP-1 receptor agonist), verapamil (calcium antagonist), acarbose (alpha glucosidase inhibitor), and pasireotide (somatostatin analogue), respectively.. (I) NT secretion was similar after TVP/CTVP (p = 0.9), but increased vs. controls (p < 0.0001). (II) NT secretion was increased after RYGB vs. SG and controls (p < 0.0001). NT responses were similar in SG and controls (p = 0.3), but early postprandial NT concentrations were higher after SG (p < 0.05). (III) Exendin (9-39) and sitagliptin did not change NT responses vs placebo (p > 0.2), but responses were lower during sitagliptin vs. exendin(9-39) (p = 0.03). (IV) Pasireotide suppressed NT secretion (p = 0.004). Sitagliptin tended to lower NT secretion (p = 0.08). Liraglutide, verapamil, and acarbose had no effect (p > 0.9).. Neurotensin secretion is increased after surgeries associated with accelerated gastric emptying and lowered by pasireotide. Topics: Blood Glucose; Gastrectomy; Gastric Bypass; Glucagon-Like Peptide 1; Humans; Hypoglycemic Agents; Liraglutide; Neurotensin; Obesity; Postprandial Period; Vagotomy, Truncal | 2022 |
Metabolic endotoxemia is dictated by the type of lipopolysaccharide.
Lipopolysaccharides (LPSs) can promote metabolic endotoxemia, which is considered inflammatory and metabolically detrimental based on Toll-like receptor (TLR)4 agonists, such as Escherichia coli-derived LPS. LPSs from certain bacteria antagonize TLR4 yet contribute to endotoxemia measured by endotoxin units (EUs). We found that E. coli LPS impairs gut barrier function and worsens glycemic control in mice, but equal doses of LPSs from other bacteria do not. Matching the LPS dose from R. sphaeroides and E. coli by EUs reveals that only E. coli LPS promotes dysglycemia and adipose inflammation, delays intestinal glucose absorption, and augments insulin and glucagon-like peptide (GLP)-1 secretion. Metabolically beneficial endotoxemia promoted by R. sphaeroides LPS counteracts dysglycemia caused by an equal dose of E. coli LPS and improves glucose control in obese mice. The concept of metabolic endotoxemia should be expanded beyond LPS load to include LPS characteristics, such as lipid A acylation, which dictates the effect of metabolic endotoxemia. Topics: Adipose Tissue; Animals; Blood Glucose; Body Weight; Endotoxemia; Escherichia coli; Glucagon-Like Peptide 1; Glucose; Insulin; Intestines; Lipopolysaccharides; Male; Mice; Mice, Inbred C57BL; Mice, Obese; Obesity; Peptidoglycan; Rhodobacter sphaeroides; Toll-Like Receptor 4 | 2021 |
Novel β-mannanase/GLP-1 fusion peptide high effectively ameliorates obesity in a mouse model by modifying balance of gut microbiota.
We constructed a novel β-mannanase/GLP-1 fusion peptide, termed MGLP_1, and evaluated its ability to ameliorate obesity in a high-fat/high-sugar diet (HFSD)-induced mouse model. Eight-wk MGLP_1 treatment notably reduced obesity, as reflected by significant changes of body weight, serum triglyceride level, fatty liver and adipose tissue distribution. Amelioration of HFSD-induced gut dysbiosis by MGLP_1 was evidenced by reduced abundance ratio of bacterial phyla Firmicutes to Bacteroidetes, enhanced abundance of beneficial probiotic genera (Bifidobacterium, Lachnospiraceae, Ileibacterium), and reduced abundance of harmful genera (Clostridium, Romboutsia). Mechanisms of weight loss were investigated by comparing effects of treatment with MGLP_1 vs. prebiotics manno-oligosaccharides (MOS). MGLP_1 ameliorated gut microbiota imbalance by enhancing carbohydrate catabolism, whereas MOS promoted glycan synthesis and metabolism. Our findings, taken together, indicate that MGLP_1 fusion peptide has strong potential for amelioration of obesity by modifying relationships between gut microbiota and lipid and glucose metabolism. Topics: Animals; Anti-Obesity Agents; beta-Mannosidase; Gastrointestinal Microbiome; Glucagon-Like Peptide 1; Glucose; Male; Mice; Mice, Inbred C57BL; Obesity; Recombinant Proteins | 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 |
Changes in glucagon-like peptide 1 and 2 levels in people with obesity after a diet-induced weight-loss intervention are related to a specific microbiota signature: A prospective cohort study.
Topics: Adult; Cohort Studies; Female; Glucagon-Like Peptide 1; Glucagon-Like Peptide 2; Humans; Male; Microbiota; Middle Aged; Obesity; Prospective Studies; Weight Reduction Programs | 2021 |
Liraglutide Activates Type 2 Deiodinase and Enhances β3-Adrenergic-Induced Thermogenesis in Mouse Adipose Tissue.
Liraglutide is a long-acting glucagon-like peptide 1 (GLP-1) receptor agonist used as an anti-hyperglycemic agent in type 2 diabetes treatment and recently approved for obesity management. Weight loss is attributed to appetite suppression, but therapy may also increase energy expenditure. To further investigate the effect of GLP-1 signaling in thermogenic fat, we assessed adipose tissue oxygen consumption and type 2 deiodinase (D2) activity in mice treated with liraglutide, both basally and after β3-adrenergic treatment.. Male C57BL/6J mice were randomly assigned to receive liraglutide (400 μg/kg, n=12) or vehicle (n=12). After 16 days, mice in each group were co-treated with the selective β3-adrenergic agonist CL316,243 (1 mg/kg, n=6) or vehicle (n=6) for 5 days. Adipose tissue depots were assessed for gene and protein expression, oxygen consumption, and D2 activity.. Liraglutide increased interscapular brown adipose tissue (iBAT) oxygen consumption and enhanced β3-adrenergic-induced oxygen consumption in iBAT and inguinal white adipose tissue (ingWAT). These effects were accompanied by upregulation of UCP-1 protein levels in iBAT and ingWAT. Notably, liraglutide increased D2 activity without significantly upregulating its mRNA levels in iBAT and exhibited additive effects to β3-adrenergic stimulation in inducing D2 activity in ingWAT.. Liraglutide exhibits additive effects to those of β3-adrenergic stimulation in thermogenic fat and increases D2 activity in BAT, implying that it may activate this adipose tissue depot by increasing intracellular thyroid activation, adding to the currently known mechanisms of GLP-1A-induced weight loss. Topics: Adipose Tissue; Adipose Tissue, Brown; Adipose Tissue, White; Adrenergic beta-3 Receptor Agonists; Animals; Dioxoles; Enzyme Activation; Glucagon-Like Peptide 1; Iodide Peroxidase; Iodothyronine Deiodinase Type II; Liraglutide; Male; Mice; Mice, Inbred C57BL; Obesity; Oxygen Consumption; Receptors, Adrenergic, beta-3; RNA, Messenger; Thermogenesis; Uncoupling Protein 1 | 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 |
Bariatric surgery reveals a gut-restricted TGR5 agonist with anti-diabetic effects.
Bariatric surgery, the most effective treatment for obesity and type 2 diabetes, is associated with increased levels of the incretin hormone glucagon-like peptide-1 (GLP-1) and changes in levels of circulating bile acids. The levels of individual bile acids in the gastrointestinal (GI) tract after surgery have, however, remained largely unstudied. Using ultra-high performance liquid chromatography-mass spectrometry-based quantification, we observed an increase in an endogenous bile acid, cholic acid-7-sulfate (CA7S), in the GI tract of both mice and humans after sleeve gastrectomy. We show that CA7S is a Takeda G-protein receptor 5 (TGR5) agonist that increases Tgr5 expression and induces GLP-1 secretion. Furthermore, CA7S administration increases glucose tolerance in insulin-resistant mice in a TGR5-dependent manner. CA7S remains gut restricted, minimizing off-target effects previously observed for TGR5 agonists absorbed into the circulation. By studying changes in individual metabolites after surgery, the present study has revealed a naturally occurring TGR5 agonist that exerts systemic glucoregulatory effects while remaining confined to the gut. Topics: Animals; Anti-Obesity Agents; Bariatric Surgery; Bile; Caco-2 Cells; Cholic Acid; Colon; Gene Expression Regulation; Glucagon-Like Peptide 1; Glucose Tolerance Test; HEK293 Cells; Humans; Insulin Resistance; Male; Mice; Mice, Inbred C57BL; Mice, Obese; Obesity; Receptors, G-Protein-Coupled; RNA, Small Interfering; Signal Transduction; Sulfates | 2021 |
Plasma dosage of ghrelin, IGF-1, GLP- 1 and leptin related to gastric emptying and esophageal pH-impedance in children with obesity.
The main aim of the study was to assess the relationship between leptin, ghrelin, insulin-like growth factor 1 (IGF-1), and glucagon-like peptide 1 (GLP-1) blood levels and gastric motility in children with obesity compared to healthy children. Secondary aims were to assess the possible association between these hormones and obesity, reflux impedance parameters, reflux symptoms, other GI disorders, and quality-of-life scores within the same groups.. Children with obesity plus GERD symptoms and 2 control groups of children with obesity without GERD and healthy lean children aged 4-17 years underwent an auxological evaluation, an assessment of gastro-intestinal symptoms and quality of life, hormonal dosages, and an evaluation of gastric emptying time (GET) through 13C-octanoic acid breath test.. No significant association was found between hormones and gastric motility. Leptin and ghrelin levels were significantly associated with obesity parameters. No significant differences were found between GET and hormones of the patients with obesity, either with or without GERD.. Although we found an association between auxological parameters and both leptin and ghrelin levels, this association did not imply an effect on the upper GI motility. Therefore, our hypothesis that alterations of these hormones in children with obesity could affect gastric emptying, triggering GERD, was not supported by our data. Topics: Child; Correlation of Data; Esophageal pH Monitoring; Female; Gastric Emptying; Gastroesophageal Reflux; Gastrointestinal Diseases; Ghrelin; Glucagon-Like Peptide 1; Humans; Insulin-Like Growth Factor I; Leptin; Male; Obesity; Quality of Life | 2021 |
Cerebral effects of glucagon-like peptide-1 receptor blockade before and after Roux-en-Y gastric bypass surgery in obese women: A proof-of-concept resting-state functional MRI study.
To assess the effects of Roux-en-Y gastric bypass surgery (RYGB)-related changes in glucagon-like peptide-1 (GLP-1) on cerebral resting-state functioning in obese women.. In nine obese females aged 40-54 years in the fasted state, we studied the effects of RYGB and GLP-1 on five a priori selected networks implicated in food- and reward-related processes as well as environment monitoring (default mode, right frontoparietal, basal ganglia, insula/anterior cingulate and anterior cingulate/orbitofrontal networks).. Before surgery, GLP-1 receptor blockade (using exendin9-39) was associated with increased right caudate nucleus (basal ganglia network) and decreased right middle frontal (right frontoparietal network) connectivity compared with placebo. RYGB resulted in decreased right orbitofrontal (insula/anterior cingulate network) connectivity. In the default mode network, after surgery, GLP-1 receptor blockade had a larger effect on connectivity in this region than GLP-1 receptor blockade before RYGB (all P. These findings suggest GLP-1 involvement in resting-state networks related to food and reward processes and monitoring of the internal and external environment, pointing to a potential role for GLP-1-induced changes in resting-state connectivity in RYGB-mediated weight loss and appetite control. Topics: Adult; Female; Gastric Bypass; Glucagon-Like Peptide 1; Glucagon-Like Peptide-1 Receptor; Humans; Magnetic Resonance Imaging; Middle Aged; Obesity | 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 |
Expected values for gastrointestinal and pancreatic hormone concentrations in healthy volunteers in the fasting and postprandial state.
Gastrointestinal hormones regulate intestinal transit, control digestion, influence appetite and promote satiety. Altered production or action of gut hormones, including glucagon-like peptide-1 (GLP-1), glucose-dependent insulinotropic polypeptide (GIP) and peptide YY (PYY), may contribute to the biological basis of obesity and altered glucose homeostasis. However, challenges in analytical methodology and lack of clarity on expected values for healthy individuals have limited progress in this field. The aim of this study was to describe expected concentrations of gastrointestinal and pancreatic hormones in healthy volunteers following a standardized meal test (SMT) or 75 g oral glucose tolerance test (OGTT).. A total of 28 healthy volunteers (12 men, 16 women; mean age 31.3 years; mean body mass index 24.9 kg/m. Ranges of expected values were created for glucose, insulin, glucagon, GLP-1, GIP, PYY and free fatty acids in response to a standardized mixed liquid meal or OGTT. Intact proinsulin and C-peptide levels were also measured following the OGTT.. These ranges of expected values can now be used to compare gut hormone concentrations between healthy individuals and patient groups. Topics: Adolescent; Adult; Aged; Blood Glucose; Fasting; Female; Gastric Inhibitory Polypeptide; Gastrointestinal Hormones; Glucagon; Glucagon-Like Peptide 1; Glucose Tolerance Test; Healthy Volunteers; Humans; Insulin; Male; Middle Aged; Obesity; Pancreatic Hormones; Peptide YY; Postprandial Period; Reference Values; Young Adult | 2021 |
Behavioural and neurochemical mechanisms underpinning the feeding-suppressive effect of GLP-1/CCK combinatorial therapy.
Combinatorial therapies are under intense investigation to develop more efficient anti-obesity drugs; however, little is known about how they act in the brain to produce enhanced anorexia and weight loss. The goal of this study was to identify the brain sites and neuronal populations engaged during the co-administration of GLP-1R and CCK1R agonists, an efficient combination therapy in obese rodents.. We measured acute and long-term feeding and body weight responses and neuronal activation patterns throughout the neuraxis and in specific neuronal subsets in response to GLP-1R and CCK1R agonists administered alone or in combination in lean and high-fat diet fed mice. We used PhosphoTRAP to obtain unbiased molecular markers for neuronal populations selectively activated by the combination of the two agonists.. The initial anorectic response to GLP-1R and CCK1R co-agonism was mediated by a reduction in meal size, but over a few hours, a reduction in meal number accounted for the sustained feeding suppressive effects. The nucleus of the solitary tract (NTS) is one of the few brain sites where GLP-1R and CCK1R signalling interact to produce enhanced neuronal activation. None of the previously categorised NTS neuronal subpopulations relevant to feeding behaviour were implicated in this increased activation. However, we identified NTS/AP Calcrl. Collectively, these studies indicated that circuit-level integration of GLP-1R and CCK1R co-agonism in discrete brain nuclei including the NTS produces enhanced rapid and sustained appetite suppression and weight loss. Topics: Animals; Anti-Obesity Agents; Appetite Regulation; Brain; Diet, High-Fat; Eating; Feeding Behavior; Glucagon-Like Peptide 1; Glucagon-Like Peptide-1 Receptor; Male; Mice; Mice, Inbred C57BL; Neurons; Obesity; Receptors, Cholecystokinin; Solitary Nucleus; Weight Loss | 2021 |
EGLP-1 lowers body weight better than exendin-4 by reducing food intake and increasing basal energy expenditure in diet-induced obese mice.
It is well known that GLP-1 activates GLP-1R to reduce body weight by inhibiting eating. GLP-1 is cleaved by the neutral endopeptidase (NEP) 24.11 into a pentapeptide GLP-1 (32-36) amide, which increases basal energy expenditure and inhibits weight gain in obese mice. It is well known that GLP-1 analogs can reduce weight by suppressing eating. However, there are few reports of reducing weight through the dual effects of inhibiting eating and increasing basic energy. Here, we report the peptide EGLP-1, a GLP-1 analogue, which can reduce food intake and increase basal energy expenditure. In C2C12 myotubes, EGLP-1 can increase both phosphorylation of acetyl CoA carboxylase (ACC) and the ratio between phosphorylation of ACC and the total expression of ACC (pACC/ACC). In diet-induced obese mice, EGLP-1 is more effective than exendin-4 in reducing body weight, reducing fat mass and improving hepatic steatosis. At the same time, EGLP-1 can improve hyperglycemia, reduce food intake, and improve insulin resistance, just like exendin-4. In addition, EGLP-1, not exendin-4, can improve physiological parameters associated with lipid metabolism and increase oxygen consumption by increasing uncoupling proteins 3 (UCP3) expression and pACC/ACC ratio in skeletal muscle. Taken together, this data showed that EGLP-1 is able to reduce body weight by reducing food intake and increasing basal energy expenditure, suggesting it may be more effective in treating diabetic and non-diabetic overweight or obese people than pure GLP-1R agonist exendin-4. Topics: Animals; Anti-Obesity Agents; Body Weight; Cells, Cultured; Diet, High-Fat; Eating; Energy Metabolism; Exenatide; Glucagon-Like Peptide 1; Male; Mice; Mice, Inbred C57BL; Mice, Obese; Obesity; Peptide Fragments | 2021 |
Obesity-related genes are expressed in human Sertoli cells and modulated by energy homeostasis regulating hormones.
The strong hormonal dysregulation associated with obesity is responsible for the disruption of several reproductive events. Sertoli cells (SCs) function is dependent on energetic homeostasis and thus, directly associated with energy homeostasis regulating hormones. To further understand the influence of those hormones with SCs function and obesity, we hypothesize that human SCs express obesity-related genes (ORG; MC4R, GNPDA2, TMEM18, and FTO) and that they respond to energy homeostasis regulating hormones (leptin, ghrelin, and glucagon-like protein 1 [GLP-1]) stimuli. To test our hypothesis, SCs were cultured with increasing doses of leptin (0, 5, 25, or 50 ng/ml, for 24 h), ghrelin (0, 20, 100, and 500 pM, for 24 h), and GLP-1 (10, 1000, or 1 × 105 pM, for 6 h). The presence and abundance of ORG transcripts and proteins in SCs were accessed by polymerase chain reaction techniques, Western blot analysis, and immunofluorescence staining. Our results show that human SCs express MC4R, GNPDA2, TMEM18, and FTO in specific cellular locations. MC4R and FTO expression in human SCs was not responsive to the treatments. However, GNPDA2 and TMEM18 expression increased after exposure to the highest concentration of leptin and ghrelin, respectively. We highlight for the first time that human SCs express ORG and that these are responsive to energy homeostasis hormonal stimuli. GNPDA2 and TMEM18 expression respond in opposite directions according to overall energy status, mediated by energy homeostasis regulating hormones. Leptin and ghrelin control of ORG expression by human SCs can be associated with overweight-related infertility and subfertility in males. Topics: Alpha-Ketoglutarate-Dependent Dioxygenase FTO; Energy Metabolism; Ghrelin; Glucagon-Like Peptide 1; Homeostasis; Humans; Leptin; Male; Membrane Proteins; Obesity; Receptor, Melanocortin, Type 4; Sertoli Cells | 2021 |
Bariatric surgery induces a new gastric mucosa phenotype with increased functional glucagon-like peptide-1 expressing cells.
Glucagon-Like Peptide-1 (GLP-1) undergoes rapid inactivation by dipeptidyl peptidase-4 (DPP4) suggesting that target receptors may be activated by locally produced GLP-1. Here we describe GLP-1 positive cells in the rat and human stomach and found these cells co-expressing ghrelin or somatostatin and able to secrete active GLP-1 in the rats. In lean rats, a gastric load of glucose induces a rapid and parallel rise in GLP-1 levels in both the gastric and the portal veins. This rise in portal GLP-1 levels was abrogated in HFD obese rats but restored after vertical sleeve gastrectomy (VSG) surgery. Finally, obese rats and individuals operated on Roux-en-Y gastric bypass and SG display a new gastric mucosa phenotype with hyperplasia of the mucus neck cells concomitant with increased density of GLP-1 positive cells. This report brings to light the contribution of gastric GLP-1 expressing cells that undergo plasticity changes after bariatric surgeries, to circulating GLP-1 levels. Topics: 1-Methyl-3-isobutylxanthine; Adult; Amino Acid Sequence; Animals; Bariatric Surgery; Diet, High-Fat; Female; Gastric Mucosa; Glucagon-Like Peptide 1; Glucose; Humans; Male; Middle Aged; Obesity; Phenotype; Rats, Wistar | 2021 |
Paternal Methyl Donor Supplementation in Rats Improves Fertility, Physiological Outcomes, Gut Microbial Signatures and Epigenetic Markers Altered by High Fat/High Sucrose Diet.
Topics: Animals; Biomarkers; Body Composition; Diet, High-Fat; Dietary Supplements; Epigenesis, Genetic; Fathers; Female; Fertility; Gastrointestinal Microbiome; Glucagon-Like Peptide 1; Male; MicroRNAs; Obesity; Peptide YY; Pregnancy; Prenatal Exposure Delayed Effects; Rats; Rats, Sprague-Dawley; Sucrose | 2021 |
Rational design and evaluation of GLP-1 derivative for treating hyperglycemia combined with overexercise-induced myocardial injury.
To design and evaluate the anti-hyperglycemia and overexercise-induced myocardial injury efficacies of a novel long-acting glucagon-like peptide-1 (GLP-1)-based therapeutic peptide in rodent animals.. Here, we designed and prepared a new pro-drug, termed RYHSB-1, which was connected by a mutated GLP-1(A8G) and an albumin binding peptide via a protease-cleavable linker. Moreover, isothermal titration calorimetry (ITC) was applied to detect its binding affinity for HSA. GLP-1 release assay was conducted in mouse serum in vitro and quantified using LC-MS/MS method. Modified intraperitoneal glucose tolerance test (IPGTT), chronic efficacies study in rodent animals with overexercise-induced myocardial injury were subjected to evaluate the druggability of RYHSB-1.. RYHSB-1 with purity over 99% was prepared and ITC measurement demonstrated high binding affinity for HSA with KD of 0.06 μM. Protease cleavage assay demonstrated slowly controlled-release of transient GLP-1 from RYHSB-1 under the hydrolysis catalyzed by thrombin in vitro. Moreover, IPGTT showed clearly dose-dependent glucose-lowering efficacies of RYHSB-1 within 0.1-0.9 mg/kg. The prolonged anti-diabetic efficacy of RYHSB-1 was further assessed via multiple IPGTTs and hypoglycemic duration test. Furthermore, long-term administration of RYHSB-1 in diabetic mice achieved promising efficacies on hyperglycemia and overexercise-induced myocardial injury.. RYHSB-1 holds outstanding pharmaceutical potential as an anti- overexercise-induced myocardial injury drug. The strategy of albumin-conjugation also could be applied to other active peptides develop long effecting therapeutic drugs. Topics: Animals; Chromatography, Liquid; Diabetes Mellitus, Experimental; Glucagon-Like Peptide 1; Glucagon-Like Peptide-1 Receptor; Glucose; Hyperglycemia; Hypoglycemic Agents; Liraglutide; Male; Mice; Mice, Inbred DBA; Obesity; Rats; Rats, Sprague-Dawley; Receptors, Glucagon; Tandem Mass Spectrometry | 2021 |
Clinical effectiveness of liraglutide on weight loss in South Koreans: First real-world retrospective data on Saxenda in Asia.
Among Asian countries, South Korea was the first to approve liraglutide as a treatment for obesity. Thus, the clinical effectiveness of liraglutide has not been studied in Asian populations.In this study, we retrospectively analyzed obese patients [body mass index (BMI) >27 kg/m2] who were treated with liraglutide between March 2018 and March 2019 in a single clinic. Weight, BMI, HbA1c, and clinical data were collected before liraglutide treatment. Changes in body weight and composition and their relationships with clinical variables were examined at re-prescription dates within 30, 60, 90, and 180 days.A total of 169 subjects were studied. The average age was 41.5 years, and 42% of the subjects were male. The average weight was 85.2 kg, and the average BMI was 30.8 kg/m2. Weight reduction was significant (-5.5 ± 3.4 kg, 30 days: -3.2 ± 1.8 kg, 60 days: -4.5 ± 2.3 kg, 90 days: -6.3 ± 2.6 kg, 180 days: -7.8 ± 3.5 kg) during the follow-up period and increased with longer treatment time (P < .001). The percentages of subjects that showed ≥ 5% and ≥ 10% body weight reduction were 62.1% and 17.2%, respectively. In the body composition analysis, skeletal muscle weight loss was -3.56 ± 29.7%, which was significantly smaller than fat weight loss of -11.06 ± 10.4% (P = .03). Weight loss was not significantly related to age, sex, baseline BMI, baseline HbA1c, smoking status, alcohol consumption, coffee intake.In conclusion, Liraglutide treatment led to meaningful weight loss in South Korean patients, and fat mass reduction was prominent during treatment. Furthermore, liraglutide showed greater clinical effectiveness with longer treatment time. Topics: Adult; Blood Glucose; Body Mass Index; Body Weights and Measures; Dose-Response Relationship, Drug; Female; Glucagon-Like Peptide 1; Glycated Hemoglobin; Humans; Life Style; Liraglutide; Male; Middle Aged; Obesity; Republic of Korea; Retrospective Studies; Weight Loss | 2021 |
MicroRNA-194: a novel regulator of glucagon-like peptide-1 synthesis in intestinal L cells.
In the status of obesity, the glucagon-like peptide-1 (GLP-1) level usually declines and results in metabolic syndrome. This study aimed to investigate the intracellular mechanism of GLP-1 synthesis in L cells from the perspective of microRNA (miRNA). In the present study, we found that GLP-1 level was down-regulated in the plasma and ileum tissues of obese mice, while the ileac miR-194 expression was up-regulated. In vitro experiments indicated that miR-194 overexpression down-regulated GLP-1 level, mRNA levels of proglucagon gene (gcg) and prohormone convertase 1/3 gene (pcsk1), and the nuclear protein level of beta-catenin (β-catenin). Further investigation confirmed that β-catenin could promote gcg transcription through binding to transcription factor 7-like 2 (TCF7L2). miR-194 suppressed gcg mRNA level via negatively regulating TCF7L2 expression. What's more, forkhead box a1 (Foxa1) could bind to the promoter of pcsk1 and enhanced its transcription. miR-194 suppressed pcsk1 transcription through targeting Foxa1. Besides, the interference of miR-194 reduced palmitate (PA)-induced cell apoptosis and the anti-apoptosis effect of miR-194 inhibitor was abolished by TCF7L2 knockdown. Finally, in HFD-induced obese mice, the silence of miR-194 significantly elevated GLP-1 level and improved the metabolic symptoms caused by GLP-1 deficiency. To sum up, our study found that miR-194 suppressed GLP-1 synthesis in L cells via inhibiting TCF7L2-mediated gcg transcription and Foxa1-mediated pcsk1 transcription. Meanwhile, miR-194 took part in the PA-induced apoptosis of L cells. Topics: Animals; Enteroendocrine Cells; Glucagon-Like Peptide 1; L Cells; Male; Mice; MicroRNAs; Obesity; Transfection | 2021 |
Beinaglutide shows significantly beneficial effects in diabetes/obesity-induced nonalcoholic steatohepatitis in ob/ob mouse model.
Beinaglutide has been approved for glucose lowering in type 2 diabetes mellitus (T2DM) in China. In addition to glycemic control, significant weight loss is observed from real world data. This study is designed to investigate the pharmacological and pharmacokinetic profiles of beinaglutide in different models.. The pharmacological efficacy of beinaglutide was evaluated in C57BL/6 and ob/ob mice after single administration. Pharmacokinetic profiles in mice were investigated after single or multiple administration. Sub-chronic pharmacological efficacy was investigated in ob/ob mice for two weeks treatment and diet-induced ob/ob mice model of nonalcoholic steatohepatitis (NASH) for four weeks treatment.. Beinaglutide could dose-dependently reduce the glucose levels and improve insulin secretion in glucose tolerance tests, inhibit food intake and gastric emptying after single administration. At higher doses, beinaglutide could inhibit food intake over 4 h, which results in weight loss in ob/ob mice after about two weeks treatment. No tachyphylaxis is observed for beinaglutide in food intake with repeated administration. In NASH model, beinaglutide could reduce liver weight and hepatic steatosis and improve insulin sensitivity. Signiant changes of gene levels were observed in fatty acid β-oxidation (Ppara, Acadl, Acox1), mitochondrial function (Mfn1, Mfn2), antioxidation (Sod2), Sirt1, and et al. SIGNIFICANCE: Our results characterize the pharmacological and pharmacokinetic profiles of beinaglutide in mice and supported that chronic use of beinaglutde could lead to weight loss and reduce hepatic steatosis, which suggest beinaglutide may be effective therapy for the treatment of obesity and NASH. Topics: Animals; Antioxidants; Diabetes Complications; Diabetes Mellitus; Glucagon-Like Peptide 1; Hypoglycemic Agents; Insulin; Insulin Resistance; Leptin; Liraglutide; Liver Cirrhosis; Male; Mice; Mice, Inbred C57BL; Mice, Obese; Non-alcoholic Fatty Liver Disease; Obesity; Oxidation-Reduction; Peptide Fragments; PPAR alpha; Weight Loss | 2021 |
S3-2, a novel long-lasting oxyntomodulin derivative, exerts improvement on diabesity and renal injury through activating GLP-1 and glucagon receptors.
To prolong the short lifespan of oxyntomodulin (OXM) for treating obesity and diabetes, we designed a novel fused OXM analog, containing an albumin-binding sequence, a protease cleavable tetrapeptide, and a mutated OXM.. We screened two albumin-binding sequences (S3 and S6) to construct OXM derivatives, termed S3-2 (with two cysteines) and S6-0 (without cysteine). After peptides were synthesized, isothermal titration calorimetry (ITC) was applied to assess binding-affinity for HSA. Further in vivo acute efficacies evaluation and candidate selection were performed in diabetic db/db mice via oral glucose tolerance test (OGTT) and glucose-lowering duration test. Chronic efficacy test of selected candidate was also performed in diabetic mice.. S3-2re exhibits outstanding therapeutical potential as a candidate drug for treating the obesity and diabetes. Topics: Albumins; Animals; Blood Glucose; Diabetes Mellitus, Experimental; Disease Models, Animal; Glucagon; Glucagon-Like Peptide 1; Glucagon-Like Peptide-1 Receptor; Glucose; Hypoglycemic Agents; Insulin; Kidney; Male; Mice; Mice, Inbred C57BL; Obesity; Oxyntomodulin; Peptides; Receptors, Glucagon | 2021 |
High β-Glucan Barley Supplementation Improves Glucose Tolerance by Increasing GLP-1 Secretion in Diet-Induced Obesity Mice.
The aim of this study was to investigate the underlying mechanism for the improvement of glucose tolerance following intake of high β-glucan barley (HGB) in terms of intestinal metabolism. C57BL/6J male mice were fed a fatty diet supplemented with HGB corresponding to 5% of dietary fiber for 83 days. An oral glucose tolerance test was performed at the end of the experimental period. The concentration of short-chain fatty acids (SCFAs) in the cecum was analyzed by GC-MS (gas chromatography-mass spectrometry). The mRNA expression levels related to L cell function in the ileum were measured by real-time PCR. Glucagon-like peptide-1 (GLP-1) levels in the portal vein and cecal content were assessed by enzyme-linked immunosorbent assay. GLP-1-producing L cells of the ileum were quantified by immunohistochemistry. HGB intake improved glucose tolerance and increased the cecal levels of SCFAs, acetate, and propionate. The number of GLP-1-positive L cells in the HGB group was significantly higher than in the control group. GLP-1 levels in the portal vein and cecal GLP-1 pool size in the HGB group were significantly higher than the control group. In conclusion, we report improved glucose tolerance after HGB intake induced by an increase in L cell number and subsequent rise in GLP-1 secretion. Topics: Animals; beta-Glucans; Blood Glucose; Bodily Secretions; Cecum; Diet, High-Fat; Dietary Supplements; Fatty Acids, Volatile; Glucagon-Like Peptide 1; Glucose Tolerance Test; Hordeum; Male; Mice; Mice, Inbred C57BL; Mice, Obese; Obesity | 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 |
The glucose-dependent insulinotropic polypeptide (GIP) regulates body weight and food intake via CNS-GIPR signaling.
Uncertainty exists as to whether the glucose-dependent insulinotropic polypeptide receptor (GIPR) should be activated or inhibited for the treatment of obesity. Gipr was recently demonstrated in hypothalamic feeding centers, but the physiological relevance of CNS Gipr remains unknown. Here we show that HFD-fed CNS-Gipr KO mice and humanized (h)GIPR knockin mice with CNS-hGIPR deletion show decreased body weight and improved glucose metabolism. In DIO mice, acute central and peripheral administration of acyl-GIP increases cFos neuronal activity in hypothalamic feeding centers, and this coincides with decreased body weight and food intake and improved glucose handling. Chronic central and peripheral administration of acyl-GIP lowers body weight and food intake in wild-type mice, but shows blunted/absent efficacy in CNS-Gipr KO mice. Also, the superior metabolic effect of GLP-1/GIP co-agonism relative to GLP-1 is extinguished in CNS-Gipr KO mice. Our data hence establish a key role of CNS Gipr for control of energy metabolism. Topics: Animals; Body Weight; Central Nervous System; Diet, High-Fat; Eating; Gastric Inhibitory Polypeptide; Glucagon-Like Peptide 1; Humans; Hypothalamus; Male; Mice; Mice, Inbred C57BL; Mice, Transgenic; Obesity; Proto-Oncogene Proteins c-fos; Receptors, Gastrointestinal Hormone; Signal Transduction | 2021 |
Alleviation of diabetes mellitus through the restoration of β-cell function and lipid metabolism by Aloe vera (L.) Burm. f. extract in obesogenic WNIN/GR-Ob rats.
Aloe vera (L.) Burm. f. extract has been medicinally used for over 5000 years in different cultures for its curative and therapeutic properties ranging from dermatitis to diabetes. It has been demonstrated to alleviate diabetes through its protective effects on pancreatic islets and by improving insulin secretion.. To investigate the simultaneous effect of ethanolic A. vera gel extract on diabetes and obesogenic milieu in Streptozotocin-induced WNIN/GR-Ob mutant obese rats.. A total of 30 rats were grouped equally into WNIN/GR-Ob control (received water as a vehicle), WNIN/GR-Ob Diabetic rats (Streptozotocin-35 mg/kg bw), WNIN/GR-Ob Diabetic rats + Sitagliptin (10 mg/kg bw), WNIN/GR-Ob Diabetic rats + A. vera (300 mg/kg bw) and GR-Ob control + A. vera (300 mg/kg bw). After 4 weeks of treatment, fasting blood glucose, serum insulin, Homeostatic Model Assessment - Insulin Resistance and β-cell function, glucose-stimulated insulin secretion, Dipeptidyl peptidase-IV activity, and lipid profiles were studied. In addition, ultrastructural analysis of isolated islets and dual-energy X-ray absorptiometry analysis for body composition were also carried out.. The A. vera treated group showed a significant reduction (p < 0.05) in triglyceride, Very low-density lipoprotein levels, Triglyceride to High-density lipoprotein ratio as well as fasting blood glucose levels and DPP-IV activity with a concomitant increase in the serum insulin levels. The increase in IR was observed in both WNIN/GR-Ob control and diabetic rats with a significant decrease in β-cell function in the diabetic rats as per Homeostatic Model Assessment values. Oral administration of A. vera was effective in both reducing Homeostatic Model Assessment-Insulin Resistance and increasing Homeostatic Model Assessment-β values. Also, the treated group demonstrated preservation of islets and a significant increase (p < 0.05) in the diameter of β-cell as evident through Scanning electron microscope analysis. The increase in lean body mass was manifested in the treated group with a reduction in Fat percent in comparison with other groups.. The beneficial effects of A. vera in WNIN/GR-Ob strain may be attributed to its ability to lower lipid profile thus improve insulin sensitivity and/or modulating β-cell function. Thus, it has great therapeutic potential as an herbal remedy for the treatment of diabetes and associated adverse effects such as obesity. The exact mechanism underlying the observation needs to be investigated further to explore the anti-obesity and anti-diabetic properties of A. vera and advocate its potential application as alternative medicine. Topics: Aloe; Animals; Anti-Obesity Agents; Blood Glucose; Body Composition; Diabetes Mellitus, Experimental; Dipeptidyl Peptidase 4; Glucagon-Like Peptide 1; Hypoglycemic Agents; Insulin; Insulin Resistance; Insulin-Secreting Cells; Lipid Metabolism; Obesity; Plant Extracts; Rats, Mutant Strains; Sitagliptin Phosphate; Streptozocin | 2021 |
Glucagon-like peptide 1 receptor (GLP-1R) agonist relieved asthmatic airway inflammation via suppression of NLRP3 inflammasome activation in obese asthma mice model.
Obesity is a correctable factor for uncontrolled bronchial asthma. However, the effects of glucagon-like peptide-1 receptor (GLP-1R) agonist, a recently approved antiobestic drug, on airway hyperresponsiveness (AHR) and immune responses are not known.. Mice were fed with high-fat diet (HFD, 60% fat) for 8 weeks to induce obesity. Ovalbumin (OVA) sensitization and challenges were performed for 7 weeks. The mice were injected intraperitoneally with GLP-1R agonist 5 times a week for 4 weeks after OVA sensitization. After AHR measurement, expression of Th2, Th17 cytokines, and interleukin (IL)-33 were measured in BALF and lung tissues. Moreover, IL-1β and activity level of nucleotide oligomerization domain-like receptor protein 3 (NLRP3) were analyzed to investigate the mechanism of GLP-1R agonist on asthmatic airway inflammation.. HFD induced significant weight gain, OVA sensitization and challenge in obese mice made eosinophilic airway inflammation, and increased AHR. Treatment with GLP-1R agonist-induced weight loss suppressed eosinophilic airway inflammation and decreased AHR. Expression of IL-4, 5, and 33 was increased in BALF of obese asthma mice followed by a decrease in response to GLP-1R agonist treatment. Moreover, lung tissue H&E stain revealed that peribronchial inflammation induced by obesity and OVA was effectively suppressed by GLP-1R agonist. Expressions of NLRP3, activated caspase-1, and IL-1β were increased in lung tissues of obese asthma mice and demonstrated a decrease in response to GLP-1R agonist treatment.. GLP-1R agonist effectively induced weight loss, suppressed eosinophilic bronchial airway inflammation, and AHR in obese asthma mice. These effects were mediated by suppression of NLRP3 inflammasome activity and IL-1β. GLP-1R agonist is proposed as a novel anti-asthmatic agent targeting the obese asthmatics. Topics: Animals; Asthma; Disease Models, Animal; Glucagon-Like Peptide 1; Inflammasomes; Inflammation; Mice; Mice, Inbred BALB C; Mice, Obese; NLR Family, Pyrin Domain-Containing 3 Protein; Obesity; Ovalbumin; Pharmaceutical Preparations | 2021 |
Characteristics of bile acid composition in high fat diet-induced nonalcoholic fatty liver disease in obese diabetic rats.
Bile acid has attracted attention as a signal transmission molecule in energy metabolism. Although a high-fat diet (HFD) or obesity is known to increase hepatic fat content and alter bile acid composition, the changes in bile acid composition due to HFD or obesity remain to be elucidated. We sought to examine the bile acid composition in high fat diet-induced non-alcoholic fatty liver disease (NAFLD) in obese diabetic rats. Eight-week-old male spontaneously diabetic Torii fatty (SDTF) rats or control rats were fed an HFD. Twelve weeks post the commencement of HFD, serum and hepatic bile acid compositions and serum GLP-1 levels, which is stimulated by the secondary bile acid deoxycholic acid (DCA), were measured. The correlation between the bile acid composition and serum GLP-1 levels was also examined. While serum and hepatic levels of cholic acid (CA), a primary bile acid, tended to decrease in HFD-fed control rats, they were significantly decreased in HFD-fed SDTF rats. Hepatic CYP8B1, which plays a role in CA synthesis, the mRNA levels were significantly decreased in HFD-fed control and SDTF rats. In contrast, while serum and hepatic DCA levels were not changed in HFD-fed control rats, they were decreased in HFD-fed SDTF rats. Hepatic DCA/CA did not change in HFD-fed SDTF rats, but significantly increased in HFD-fed control rats. While serum GLP-1 levels were not changed in SDTF rats, they were significantly increased in HFD-fed control rats. Hepatic DCA/CA tended to correlate with serum GLP-1 levels, which tended to negatively correlate with the hepatic triglyceride content in SDTF rats. These results indicate that relatively increased DCA might contribute to an increase in serum GLP-1 levels, which inhibits hepatic steatosis in NAFLD. Topics: Animals; Bile Acids and Salts; Blood Glucose; Diabetes Mellitus, Experimental; Diet, High-Fat; Fatty Acids; Gene Expression Regulation; Glucagon-Like Peptide 1; Insulin Resistance; Liver; Male; Non-alcoholic Fatty Liver Disease; Obesity; Rats, Sprague-Dawley; Triglycerides | 2021 |
Selective release of gastrointestinal hormones induced by an orally active GPR39 agonist.
Obesity is a complex disease associated with a high risk of comorbidities. Gastric bypass surgery, an invasive procedure with low patient eligibility, is currently the most effective intervention that achieves sustained weight loss. This beneficial effect is attributed to alterations in gut hormone signaling. An attractive alternative is to pharmacologically mimic the effects of bariatric surgery by targeting several gut hormonal axes. The G protein-coupled receptor 39 (GPR39) expressed in the gastrointestinal tract has been shown to mediate ghrelin signaling and control appetite, food intake, and energy homeostasis, but the broader effect on gut hormones is largely unknown. A potent and efficacious GPR39 agonist (Cpd1324) was recently discovered, but the in vivo function was not addressed. Herein we studied the efficacy of the GPR39 agonist, Cpd1324, on metabolism and gut hormone secretion.. Body weight, food intake, and energy expenditure in GPR39 agonist-treated mice and GPR39 KO mice were studied in calorimetric cages. Plasma ghrelin, glucose-dependent insulinotropic polypeptide (GIP), glucagon-like peptide-1 (GLP-1), and peptide YY (PYY) levels were measured. Organoids generated from murine and human small intestine and mouse colon were used to study GLP-1 and PYY release. Upon GPR39 agonist administration, dynamic changes in intracellular GLP-1 content were studied via immunostaining and changes in ion transport across colonic mucosa were monitored in Ussing chambers. The G protein activation underlying GPR39-mediated selective release of gut hormones was studied using bioluminescence resonance energy transfer biosensors.. The GPR39 KO mice displayed a significantly increased food intake without corresponding increases in respiratory exchange ratios or energy expenditure. Oral administration of a GPR39 agonist induced an acute decrease in food intake and subsequent weight loss in high-fat diet (HFD)-fed mice without affecting their energy expenditure. The tool compound, Cpd1324, increased GLP-1 secretion in the mice as well as in mouse and human intestinal organoids, but not in GPR39 KO mouse organoids. In contrast, the GPR39 agonist had no effect on PYY or GIP secretion. Transepithelial ion transport was acutely affected by GPR39 agonism in a GLP-1- and calcitonin gene-related peptide (CGRP)-dependent manner. Analysis of Cpd1324 signaling properties showed activation of Gα. The GPR39 agonist described in this study can potentially be used by oral administration as a weight-lowering agent due to its stimulatory effect on GLP-1 secretion, which is most likely mediated through a unique activation of Gα subunits. Thus, GPR39 agonism may represent a novel approach to effectively treat obesity through selective modulation of gastrointestinal hormonal axes. Topics: Animals; Appetite Regulation; Bariatric Surgery; Body Weight; Eating; Enteroendocrine Cells; Gastric Inhibitory Polypeptide; Gastrointestinal Hormones; Ghrelin; Glucagon-Like Peptide 1; Humans; Male; Mice; Mice, Inbred C57BL; Mice, Knockout; Obesity; Peptide YY; Receptors, G-Protein-Coupled; Receptors, Gastrointestinal Hormone; Weight Loss | 2021 |
Engineered Bacteria of MG1363-pMG36e-GLP-1 Attenuated Obesity-Induced by High Fat Diet in Mice.
Although gut hormone glucagon-like peptide 1 (GLP-1) has been widely used for treating diabetes, the extremely short half-life greatly limits its application. The purpose of this study is to explore the effects of an engineered bacteria with expression of GLP-1 on obese mice induced by high fat diet (HFD).. The engineered strain of MG1363-pMG36e-GLP-1 (M-GLP-1) was constructed and its anti-obesity effects were evaluated. The engineered bacteria could produce GLP-1. It also significantly decreased the bodyweight and improved the glucose intolerance in the obese mice induced by HFD. Moreover, the strain also reduced the triglyceride (TG) in serum, protected liver, as well as decreased the intracellular TG in liver tissues of the obese mice. Furthermore, our results showed that the expressions of the genes including peroxisome proliferator-activated receptors α (PPARα) and its target genes were enhanced in liver tissues when mice treated with M-GLP-1. Finally, we found that the engineered strain markedly increased intestinal microbial diversity.. Our results suggested the genetically engineered bacteria that constitutively secreted GLP-1 could improve obesity and the mechanism may be related to promoting fatty acid oxidation and increasing intestinal microbial diversity of the obese mice. Topics: Animals; Bacteria; Diet, High-Fat; Glucagon-Like Peptide 1; Liver; Mice; Mice, Inbred C57BL; Mice, Obese; Obesity | 2021 |
Obesity and Dietary Added Sugar Interact to Affect Postprandial GLP-1 and Its Relationship to Striatal Responses to Food Cues and Feeding Behavior.
It has been hypothesized that the incretin hormone, glucagon-like peptide-1 (GLP-1), decreases overeating by influencing mesolimbic brain regions that process food-cues, including the dorsal striatum. We previously showed that habitual added sugar intake was associated with lower glucose-induced circulating GLP-1 and a greater striatal response to high calorie food cues in lean individuals. Less is known about how dietary added sugar and obesity may interact to affect postprandial GLP-1 and its relationship to striatal responses to food cues and feeding behavior. The current study aimed to expand upon previous research by assessing how circulating GLP-1 and striatal food cue reactivity are affected by acute glucose consumption in participants with varied BMIs and amounts of habitual consumption of added sugar. This analysis included 72 participants from the Brain Response to Sugar Study who completed two study visits where they consumed either plain water or 75g glucose dissolved in water (order randomized; both drinks were flavored with non-caloric cherry flavoring) and underwent repeated blood sampling, a functional magnetic resonance imaging (fMRI) based food-cue task, and an ad-libitum buffet meal. Correlations between circulating GLP-1 levels, striatal food-cue reactivity, and food intake were assessed, and interactions between obesity and added sugar on GLP-1 and striatal responses were examined. An interaction between BMI and dietary added sugar was associated with reduced post-glucose GLP-1 secretion. Participants who were obese and consumed high levels of added sugar had the smallest increase in plasma GLP-1 levels. Glucose-induced GLP-1 secretion was correlated with lower dorsal striatal reactivity to high-calorie versus low-calorie food-cues, driven by an increase in reactivity to low calorie food-cues. The increase in dorsal striatal reactivity to low calorie food-cues was negatively correlated with sugar consumed at the buffet. These findings suggest that an interaction between obesity and dietary added sugar intake is associated with additive reductions in postprandial GLP-1 secretion. Additionally, the results suggest that changes to dorsal striatal food cue reactivity through a combination of dietary added sugar and obesity may affect food consumption. Topics: Adult; Animals; Appetite; Behavior, Animal; Blood Glucose; Body Mass Index; Corpus Striatum; Cues; Energy Intake; Feeding Behavior; Female; Gastric Inhibitory Polypeptide; Glucagon-Like Peptide 1; Glucose; Humans; Insulin; Magnetic Resonance Imaging; Male; Meals; Obesity; Postprandial Period; Young Adult | 2021 |
Reversal of Functional Brain Activity Related to Gut Microbiome and Hormones After VSG Surgery in Patients With Obesity.
Vertical sleeve gastrectomy (VSG) is becoming a prioritized surgical intervention for obese individuals; however, the brain circuits that mediate its effective control of food intake and predict surgical outcome remain largely unclear.. We investigated VSG-correlated alterations of the gut-brain axis.. In this observational cohort study, 80 patients with obesity were screened. A total of 36 patients together with 26 normal-weight subjects were enrolled and evaluated using the 21-item Three-Factor Eating Questionnaire (TFEQ), MRI scanning, plasma intestinal hormone analysis, and fecal sample sequencing. Thirty-two patients underwent VSG treatment and 19 subjects completed an average of 4-month follow-up evaluation. Data-driven regional homogeneity (ReHo) coupled with seed-based connectivity analysis were used to quantify VSG-related brain activity. Longitudinal alterations of body weight, eating behavior, brain activity, gastrointestinal hormones, and gut microbiota were detected and subjected to repeated measures correlation analysis.. VSG induced significant functional changes in the right putamen (PUT.R) and left supplementary motor area, both of which correlated with weight loss and TFEQ scores. Moreover, postprandial levels of active glucagon-like peptide-1 (aGLP-1) and Ghrelin were associated with ReHo of PUT.R; meanwhile, relative abundance of Clostridia increased by VSG was associated with improvements in aGLP-1 secretion, PUT.R activity, and weight loss. Importantly, VSG normalized excessive functional connectivities with PUT.R, among which baseline connectivity between PUT.R and right orbitofrontal cortex was related to postoperative weight loss.. VSG causes correlated alterations of gut-brain axis, including Clostridia, postprandial aGLP-1, PUT.R activity, and eating habits. Preoperative connectivity of PUT.R may represent a potential predictive marker of surgical outcome in patients with obesity. Topics: Adult; Body Weight; Brain; Cerebral Cortex; Cohort Studies; Eating; Female; Gastrectomy; Gastrointestinal Hormones; Gastrointestinal Microbiome; Ghrelin; Glucagon-Like Peptide 1; Humans; Magnetic Resonance Imaging; Male; Motor Cortex; Obesity; Putamen; Surveys and Questionnaires; Treatment Outcome; Young Adult | 2021 |
GRK Inhibition Potentiates Glucagon-Like Peptide-1 Action.
The glucagon-like peptide-1 receptor (GLP-1R) is a G-protein-coupled receptor (GPCR) whose activation results in suppression of food intake and improvement of glucose metabolism. Several receptor interacting proteins regulate the signaling of GLP-1R such as G protein-coupled receptor kinases (GRK) and β-arrestins. Here we evaluated the physiological and pharmacological impact of GRK inhibition on GLP-1R activity leveraging small molecule inhibitors of GRK2 and GRK3. We demonstrated that inhibition of GRK: i) inhibited GLP-1-mediated β-arrestin recruitment, ii) enhanced GLP-1-induced insulin secretion in isolated islets and iii) has additive effect with dipeptidyl peptidase 4 in mediating suppression of glucose excursion in mice. These findings highlight the importance of GRK to modulate GLP-1R function Topics: Amides; Animals; beta-Arrestins; Calcium; CHO Cells; Cricetulus; Diabetes Mellitus; Dipeptidyl Peptidase 4; Eating; G-Protein-Coupled Receptor Kinase 1; Glucagon-Like Peptide 1; Glucagon-Like Peptide-1 Receptor; Glucose; Humans; Insulin; Islets of Langerhans; Mice; Obesity; Phosphorylation; Receptors, Glucagon; Renal Insufficiency, Chronic; Signal Transduction | 2021 |
Leptin Receptors Are Not Required for Roux-en-Y Gastric Bypass Surgery to Normalize Energy and Glucose Homeostasis in Rats.
Sensitization to the adipokine leptin is a promising therapeutic strategy against obesity and its comorbidities and has been proposed to contribute to the lasting metabolic benefits of Roux-en-Y gastric bypass (RYGB) surgery. We formally tested this idea using Zucker fatty Topics: Animals; Blood Glucose; Disease Models, Animal; Energy Metabolism; Fatty Liver; Gastric Bypass; Glucagon-Like Peptide 1; Glucose Tolerance Test; Homeostasis; Insulin; Obesity; Postoperative Period; Rats; Rats, Wistar; Rats, Zucker; Receptors, Leptin; Weight Loss | 2021 |
The relation between postprandial glucagon-like peptide-1 release and insulin sensitivity before and after bariatric surgery in humans with class II/III obesity.
Glucagon-like peptide-1 (GLP-1) receptor agonist treatment is beneficial for the human glucose metabolism, and GLP-1 secretion is greatly enhanced following Roux-en-Y gastric bypass (RYGB).. To elucidate the relationship between GLP-1 concentrations and insulin sensitivity in subjects with class II/III obesity without diabetes and to assess the relation between GLP-1 and the improvements in glucose metabolism following RYGB.. Clinical research facility in a university hospital.. We recruited 35 patients scheduled for RYGB and assessed their plasma GLP-1, insulin, and glucose responses to a high-fat mixed meal. Basal and insulin-mediated glucose fluxes were determined during a 2-step hyperinsulinemic-euglycemic clamp with stable isotope-labeled tracers. Out of 35 subjects, 10 were studied both before surgery and at 1 year of follow-up.. Plasma GLP-1 increased following the high-fat mixed meal. Postprandial GLP-1 excursions correlated positively with hepatic and peripheral insulin sensitivity, but not with body mass index. At 1 year after RYGB, participants had lost 24% ± 6% of their body weight. Plasma GLP-1, insulin, and glucose levels peaked earlier and higher after the mixed meal. The positive association between the postprandial GLP-1 response and peripheral insulin sensitivity persisted.. Postprandial GLP-1 concentrations correlate with insulin sensitivity in subjects with class II/III obesity without diabetes before and 1 year after RYGB. Increased GLP-1 signaling in postbariatric patients may, directly or indirectly, contribute to the observed improvements in insulin sensitivity and metabolic health. Topics: Bariatric Surgery; Blood Glucose; Gastric Bypass; Glucagon-Like Peptide 1; Humans; Insulin; Insulin Resistance; Obesity; Postprandial Period | 2021 |
GIPR antagonist antibodies conjugated to GLP-1 peptide are bispecific molecules that decrease weight in obese mice and monkeys.
Glucose-dependent insulinotropic polypeptide (GIP) and glucagon-like peptide-1 (GLP-1) regulate glucose and energy homeostasis. Targeting both pathways with GIP receptor (GIPR) antagonist antibody (GIPR-Ab) and GLP-1 receptor (GLP-1R) agonist, by generating GIPR-Ab/GLP-1 bispecific molecules, is an approach for treating obesity and its comorbidities. In mice and monkeys, these molecules reduce body weight (BW) and improve many metabolic parameters. BW loss is greater with GIPR-Ab/GLP-1 than with GIPR-Ab or a control antibody conjugate, suggesting synergistic effects. GIPR-Ab/GLP-1 also reduces the respiratory exchange ratio in DIO mice. Simultaneous receptor binding and rapid receptor internalization by GIPR-Ab/GLP-1 amplify endosomal cAMP production in recombinant cells expressing both receptors. This may explain the efficacy of the bispecific molecules. Overall, our GIPR-Ab/GLP-1 molecules promote BW loss, and they may be used for treating obesity. Topics: Animals; Body Weight; Gastric Inhibitory Polypeptide; Glucagon-Like Peptide 1; Glucagon-Like Peptide-1 Receptor; Glucose Tolerance Test; Haplorhini; Mice, Obese; Obesity; Receptors, Gastrointestinal Hormone | 2021 |
What combines best with GLP-1 for obesity treatment: GIP receptor agonists or antagonists?
Lu et al. Topics: Animals; Gastric Inhibitory Polypeptide; Glucagon-Like Peptide 1; Glucagon-Like Peptide-1 Receptor; Obesity; Receptors, Gastrointestinal Hormone | 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 |
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 |
Comment on: The relation between postprandial glucagon-like peptide-1 release and insulin sensitivity before and after bariatric surgery in humans with class II/III obesity.
Topics: Bariatric Surgery; Glucagon-Like Peptide 1; Humans; Insulin Resistance; Obesity; Postprandial Period | 2021 |
Intestinal MYC modulates obesity-related metabolic dysfunction.
MYC is a transcription factor with broad biological functions, notably in the control of cell proliferation. Here, we show that intestinal MYC regulates systemic metabolism. We find that MYC expression is increased in ileum biopsies from individuals with obesity and positively correlates with body mass index. Intestine-specific reduction of MYC in mice improves high-fat-diet-induced obesity, insulin resistance, hepatic steatosis and steatohepatitis. Mechanistically, reduced expression of MYC in the intestine promotes glucagon-like peptide-1 (GLP-1) production and secretion. Moreover, we identify Cers4, encoding ceramide synthase 4, catalysing de novo ceramide synthesis, as a MYC target gene. Finally, we show that administration of the MYC inhibitor 10058-F4 has beneficial effects on high-fat-diet-induced metabolic disorders, and is accompanied by increased GLP-1 and reduced ceramide levels in serum. This study positions intestinal MYC as a putative drug target against metabolic diseases, including non-alcoholic fatty liver disease and non-alcoholic steatohepatitis. Topics: Animals; Biomarkers; Diet, High-Fat; Disease Models, Animal; Disease Susceptibility; Glucagon-Like Peptide 1; Humans; Ilium; Insulin Resistance; Intestinal Mucosa; Mice; Non-alcoholic Fatty Liver Disease; Obesity; Proto-Oncogene Proteins c-myc | 2021 |
Central GLP-1 contributes to improved cognitive function and brain glucose uptake after duodenum-jejunum bypass on obese and diabetic rats.
The improvement of cognitive function following bariatric surgery has been highlighted, yet its underlying mechanisms remain elusive. Finding the improved brain glucose uptake of patients after Roux-en-Y gastric bypass (RYGB), duodenum-jejunum bypass (DJB), and sham surgery (Sham) were performed on obese and diabetic Wistar rats, and intracerebroventricular (ICV) injection of glucagon-like peptide-1 (GLP-1) analog liraglutide (Lira), antagonist exendin-(9-39) (Exe-9), and the viral-mediated GLP-1 receptor ( Topics: Animals; Brain; Cognition; Diabetes Mellitus, Experimental; Duodenum; Gastric Bypass; Glucagon-Like Peptide 1; Glucose; Jejunum; Obesity; Rats, Wistar | 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 |
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 |
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 |
Inhibition of MGAT2 modulates fat-induced gut peptide release and fat intake in normal mice and ameliorates obesity and diabetes in ob/ob mice fed on a high-fat diet.
Monoacylglycerol O-acyltransferase 2 (MGAT2) is one of the key enzymes responsible for triglyceride (TG) re-synthesis in the small intestine. We have previously demonstrated that pharmacological inhibition of MGAT2 has beneficial effects on obesity and metabolic disorders in mice. Here, we further investigate the effects of MGAT2 inhibition on (a) fat-induced gut peptide release and fat intake in normal mice and (b) metabolic disorders in high-fat diet (HFD)-fed ob/ob mice, a model of severe obesity and type 2 diabetes mellitus, using an orally bioavailable MGAT2 inhibitor Compound B (CpdB). CpdB inhibited elevation of plasma TG in mice challenged with an oil-supplemented liquid meal. Oil challenge stimulated the secretion of two gut anorectic hormones (peptide tyrosine-tyrosine and glucagon-like peptide-1) into the bloodstream, and these responses were augmented in mice pretreated with CpdB. In a two-choice test using an HFD and a low-fat diet, CpdB selectively inhibited intake of the HFD in normal mice. Administration of CpdB to HFD-fed ob/ob mice for 5 weeks suppressed food intake and body weight gain and inhibited elevation of glycated hemoglobin. These results indicate that pharmacological MGAT2 inhibition modulates fat-induced gut peptide release and fat intake in normal mice and improves obesity and diabetes in HFD-fed ob/ob mice and thus may have potential for development into a treatment of obesity and its related metabolic diseases. Topics: Acyltransferases; Animals; Diet, High-Fat; Dietary Fats; Dipeptides; Eating; Energy Metabolism; Glucagon-Like Peptide 1; Male; Mice; Mice, Inbred C57BL; Mice, Obese; Obesity; Triglycerides; Weight Gain | 2020 |
Effects and Mechanisms of Vagal Nerve Stimulation on Body Weight in Diet-Induced Obese Rats.
Vagal nerve stimulation (VNS) has recently been indicated as a novel method for treating obesity. However, the optimal stimulation parameters were unknown and mechanisms were poorly understood. The aim of this study was to investigate the effects of VNS on food intake and body weight in diet-induced obesity (DIO) rats and its possible mechanism involving autonomic functions and gut hormones.. Ten control rats and 16 DIO rats were chronically implanted with one pair of electrodes in the subdiaphragmatic vagal nerve. VNS with different stimulation parameters and sham-VNS were performed in control rats. In a chronic study, 8 DIO rats were applied with VNS and another 8 DIO rats were treated with sham-VNS for 4 weeks. Food intake, body weight, gastric emptying, heart rate variability (HRV), and gut hormones were evaluated.. In DIO rats, the food intake (p < 0.001) and body weight (p < 0.001) were significantly decreased in the VNS group, compared with the sham-VNS group. VNS decreased the sympathovagal ratio (p = 0.003) and increased vagal activity (p = 0.032) assessed from the spectral analysis of HRV. It also increased plasma levels of glucagon-like peptide-1 (p = 0.012), polypeptide YY (p = 0.008), and pancreatic polypeptide (p = 0.008) in DIO rats. Physiologically, VNS delayed solid gastric emptying (p < 0.001) and increased gastric volume (p = 0.004).. VNS with appropriate parameters reduced food intake and body weight by delaying gastric emptying mediated via the enhancement of vagal activity and release of anorexigenic hormones. Topics: Animals; Body Weight; Diet, High-Fat; Eating; Gastric Emptying; Gastrointestinal Hormones; Glucagon-Like Peptide 1; Male; Obesity; Rats; Rats, Sprague-Dawley; Vagus Nerve; Vagus Nerve Stimulation | 2020 |
Let-7e-5p Regulates GLP-1 Content and Basal Release From Enteroendocrine L Cells From DIO Male Mice.
Characterization of enteroendocrine L cells in diabetes is critical for better understanding of the role of glucagon-like peptide-1 (GLP-1) in physiology and diabetes. We studied L-cell transcriptome changes including microRNA (miRNA) dysregulation in obesity and diabetes. We evaluated the regulation of miRNAs through microarray analyses on sorted enteroendocrine L cells from control and obese glucose-intolerant (I-HFD) and hyperglycemic (H-HFD) mice after 16 weeks of respectively low-fat diet (LFD) or high-fat diet (HFD) feeding. The identified altered miRNAs were studied in vitro using the mouse GLUTag cell line to investigate their regulation and potential biological functions. We identified that let-7e-5p, miR-126a-3p, and miR-125a-5p were differentially regulated in L cells of obese HFD mice compared with control LFD mice. While downregulation of let-7e-5p expression was observed in both I-HFD and H-HFD mice, levels of miR-126a-3p increased and of miR-125a-5p decreased significantly only in I-HFD mice compared with controls. Using miRNA inhibitors and mimics we observed that modulation of let-7e-5p expression affected specifically GLP-1 cellular content and basal release, whereas Gcg gene expression and acute GLP-1 secretion and cell proliferation were not affected. In addition, palmitate treatment resulted in a decrease of let-7e-5p expression along with an increase in GLP-1 content and release, suggesting that palmitate acts on GLP-1 through let-7e-5p. By contrast, modulation of miR-125a-5p and miR-126a-3p in the same conditions did not affect content or secretion of GLP-1. We conclude that decrease of let-7e-5p expression in response to palmitate may constitute a compensatory mechanism contributing to maintaining constant glycemia in obese mice. Topics: Animals; Cell Line; Diet, High-Fat; Enteroendocrine Cells; Glucagon-Like Peptide 1; Male; Mice, Transgenic; MicroRNAs; Obesity; Palmitates | 2020 |
Genetically Engineered Escherichia coli Nissle 1917 Secreting GLP-1 Analog Exhibits Potential Antiobesity Effect in High-Fat Diet-Induced Obesity Mice.
This study aimed to investigate the potential antiobesity effect of genetically modified Escherichia coli Nissle 1917 (EcN-GM) in mice fed a high-fat diet (HFD).. The mice were randomly divided into six groups: a normal diet group (ND), a HFD group, a HFD + EcN group, and three HFD + EcN-GM groups. The effects of EcN-GM on body weight, food intake, fat pad and organ weight, and an oral glucose tolerance test were measured, in addition to hepatic biochemistry and histological analysis. The mRNA expression of neuropeptides related to food intake regulation in the hypothalamus was also detected.. The results showed that EcN-GM decreased body weight, body weight gain, food intake, fat pad weight, and hepatic weight of HFD mice. There were beneficial effects of EcN-GM on blood glucose, hepatic biochemistry, and hepatic histological alterations. A dramatic switch of food intake-regulating gene expression in the hypothalamus was also observed in mice.. This work has revealed that a modified live bacterial therapeutic, EcN-GM, has potential beneficial effects on obesity. This effect may be related to the regulating of the neuropeptide expression of energy intake and expenditure in the hypothalamus. This study demonstrates a successful example of engineered EcN-GM as a novel approach for weight management. Topics: Animals; Blood Glucose; Diet, High-Fat; Escherichia coli; Glucagon-Like Peptide 1; Male; Mice; Mice, Inbred C57BL; Obesity | 2020 |
Exercise Training Rapidly Increases Hepatic Insulin Extraction in NAFLD.
We aimed to determine the immediacy of exercise intervention on liver-specific metabolic processes in nonalcoholic fatty liver disease.. We undertook a short-term (7-d) exercise training study (60 min·d treadmill walking at 80%-85% of maximal heart rate) in obese adults (N = 13, 58 ± 3 yr, 34.3 ± 1.1 kg·m, >5% hepatic lipid by H-magnetic resonance spectroscopy). Insulin sensitivity index was estimated by oral glucose tolerance test using the Soonthorpun model. Hepatic insulin extraction (HIE) was calculated as the molar difference in area under the curve (AUC) for insulin and C-peptide (HIE = 1 - (AUCInsulin/AUCC-Pep)).. The increases in HIE, V˙O2max, and insulin sensitivity index after the intervention were 9.8%, 9.8%, and 34%, respectively (all, P < 0.05). Basal fat oxidation increased (pre: 47 ± 6 mg·min vs post: 65 ± 6 mg·min, P < 0.05) and carbohydrate oxidation decreased (pre: 160 ± 20 mg·min vs post: 112 ± 15 mg·min, P < 0.05) with exercise training. After the intervention, HIE correlated positively with adiponectin (r = 0.56, P < 0.05) and negatively with TNF-α (r = -0.78, P < 0.001).. By increasing HIE along with peripheral insulin sensitivity, aerobic exercise training rapidly reverses some of the underlying physiological mechanisms associated with nonalcoholic fatty liver disease, in a weight loss-independent manner. This reversal could potentially act through adipokine-related pathways. Topics: Blood Glucose; C-Peptide; Carbohydrate Metabolism; Exercise; Glucagon-Like Peptide 1; Heart Rate; Humans; Insulin; Insulin Resistance; Lipid Metabolism; Liver; Middle Aged; Non-alcoholic Fatty Liver Disease; Obesity; Oxygen Consumption | 2020 |
The Role of High Fat Diets and Liver Peptidase Activity in the Development of Obesity and Insulin Resistance in Wistar Rats.
High-fat diets (HFD) have been widely associated with an increased risk of metabolic disorders and overweight. However, a high intake of sources that are rich in monounsaturated fatty acids has been suggested as a dietary agent that is able to positively influence energy metabolism and vascular function. The main objective of this study was to analyze the role of dietary fats on hepatic peptidases activities and metabolic disorders. Three diets: standard (S), HFD supplemented with virgin olive oil (VOO), and HFD supplemented with butter plus cholesterol (Bch), were administered over six months to male Wistar rats. Plasma and liver samples were collected for clinical biochemistry and aminopeptidase activities (AP) analysis. The expression of inducible nitric oxide synthase (iNOS) was also determined by Western blot in liver samples. The diet supplement with VOO did not induce obesity, in contrast to the Bch group. Though the VOO diet increased the time that was needed to return to the basal levels of plasma glucose, the fasting insulin/glucose ratio and HOMA2-%B index (a homeostasis model index of insulin secretion and valuation of β-cell usefulness (% β-cell secretion)) were improved. An increase of hepatic membrane-bound dipeptidyl-peptidase 4 (DPP4) activity was found only in VOO rats, even if no differences in fasting plasma glucagon-like peptide 1 (GLP-1) were obtained. Both HFDs induced changes in hepatic pyroglutamyl-AP in the soluble fraction, but only the Bch diet increased the soluble tyrosyl-AP. Angiotensinase activities that are implicated in the metabolism of angiotensin II (AngII) to AngIV increased in the VOO diet, which was in agreement with the higher activity of insulin-regulated-AP (IRAP) in this group. Otherwise, the diet that was enriched with butter increased soluble gamma-glutamyl transferase (GGT) and Leucyl-AP, iNOS expression in the liver, and plasma NO. In summary, VOO increased the hepatic activity of AP that were related to glucose metabolism (DPP4, angiotensinases, and IRAP). However, the Bch diet increased activities that are implicated in the control of food intake (Tyrosine-AP), the index of hepatic damage (Leucine-AP and GGT), and the expression of hepatic iNOS and plasma NO. Taken together, these results support that the source of fat in the diet affects several peptidases activities in the liver, which could be related to alterations in feeding behavior and glucose metabolism. Topics: Animals; Diet, High-Fat; Dipeptidyl Peptidase 4; Energy Intake; Feeding Behavior; gamma-Glutamyltransferase; Glucagon-Like Peptide 1; Glucose Tolerance Test; Insulin Resistance; Liver; Male; Nitric Oxide; Nitric Oxide Synthase Type II; Obesity; Peptide Hydrolases; Pyroglutamyl-Peptidase I; Rats, Wistar | 2020 |
Newly identified peptide hormone inhibits intestinal fat absorption and improves NAFLD through its receptor GPRC6A.
Circulating peptides and G protein-coupled receptors (GPCRs) have gained much attention because of their biofunctions in metabolic disorders including obesity and non-alcoholic fatty liver disease (NAFLD). Herein, we aimed to characterize the role and therapeutic potential of a newly identified peptide hormone in NAFLD.. Using bioinformatics, we identified a murine circulating pentadecapeptide flanked by potential convertase cleavage sites of osteocalcin (OCN), which we named 'metabolitin (MTL)'. We used ligand-receptor binding, receptor internalization, bioluminescence resonance energy transfer and Nano isothermal titration calorimetry assays to study the binding relationship between MTL and GPRC6A. For in vivo biological studies, wild-type mice kept on a high-fat diet (HFD) were injected or gavaged with MTL to study its function in NAFLD.. We confirmed that MTL binds to GPRC6A and OCN interacts with GPRC6A using in vitro biological studies. Both intraperitoneal and oral administration of MTL greatly improved NAFLD and insulin resistance in a mouse model. Interacting with GPRC6A expressed in intestines, MTL can significantly inhibit intestinal neurotensin secretion, which in turn inhibits triglyceride but not cholesterol gut absorption, mediated by the 5'AMP-activated protein kinase pathway. In addition, glucagon like peptide-1 secretion was induced by MTL treatment.. Oral or intraperitoneal MTL significantly improves the symptoms of NAFLD by inhibiting lipid absorption and insulin resistance. MTL could be a potential therapeutic candidate for the treatment of NAFLD.. A novel murine peptide hormone, herein named 'metabolitin', inhibits fatty acid absorption and improves systemic insulin resistance in a murine model of obesity and non-alcoholic fatty liver disease. Thus, metabolitin has therapeutic potential for the treatment of patients with non-alcoholic fatty liver disease. Topics: Animals; Dietary Fats; Disease Models, Animal; Glucagon-Like Peptide 1; Hypolipidemic Agents; Insulin Resistance; Intestinal Absorption; Mice; Non-alcoholic Fatty Liver Disease; Obesity; Osteocalcin; Peptide Hormones; Receptors, G-Protein-Coupled; Signal Transduction; Treatment Outcome; Triglycerides | 2020 |
Changes in the Homeostatic Appetite System After Weight Loss Reflect a Normalization Toward a Lower Body Weight.
To compare appetite markers in reduced-obese individuals with a nonobese control group.. A total of 34 adults with obesity who lost 17% body weight at week 13 and maintained this weight loss (WL) at 1 year were compared with 33 nonobese controls matched for body composition. Basal and postprandial subjective appetite ratings and appetite-related hormone concentrations (ghrelin, total peptide YY, peptide YY3-36, total and active glucagon-like peptide 1, and cholecystokinin) were measured in all participants and repeated at week 13 and 1 year in the weight-reduced group.. WL led to a reduction in prospective food consumption and an increase in feelings of hunger, fullness, and ghrelin secretion (basal and postprandial), but these new ratings were no different from those seen in controls. Postprandial concentrations of active glucagon-like peptide 1, total peptide YY, and cholecystokinin were lower in individuals with obesity at all time points compared with controls.. The increased drive to eat (both subjective feelings of hunger and ghrelin concentrations) seen in reduced-obese individuals, both after acute and sustained WL, reflects a normalization toward a lower body weight. Overall, WL does not have a sustained negative impact on satiety peptide secretion, despite a blunted secretion in individuals with obesity compared with nonobese controls. Topics: Adult; Appetite; Body Mass Index; Body Weight; Cholecystokinin; Eating; Female; Ghrelin; Glucagon-Like Peptide 1; Homeostasis; Humans; Male; Middle Aged; Obesity; Peptide YY; Satiation; Weight Loss | 2020 |
Farnesoid X receptor contributes to body weight-independent improvements in glycemic control after Roux-en-Y gastric bypass surgery in diet-induced obese mice.
Roux-en-Y gastric bypass surgery (RYGB) can achieve long-term remission of type 2 diabetes. However, the specific molecular mechanism through which this occurs has remained largely elusive. Bile acid signaling through the nuclear hormone receptor farnesoid X receptor (FXR) exerts beneficial effects after sleeve gastrectomy (VSG), which has similar effects to RYGB. Therefore, we investigated whether FXR signaling is necessary to mediate glycemic control after RYGB.. RYGB or sham surgery was performed in high-fat diet-induced obese FXR-/- (knockout) and FXR+/+ (wild type) littermates. Sham-operated mice were fed ad libitum (S-AL) or by weight matching (S-WM) to RYGB mice via caloric restriction. Body weight, body composition, food intake, energy expenditure, glucose tolerance tests, insulin tolerance tests, and homeostatic model assessment of insulin resistance were performed.. RYGB surgery decreases body weight and fat mass in WT and FXR-KO mice. RYGB surgery has similar effects on food intake and energy expenditure independent of genotype. In addition, body weight-independent improvements in glucose control were attenuated in FXR -/- relative to FXR +/+ mice after RYGB. Furthermore, pharmacologic blockade of the glucagon-like peptide-1 receptor (GLP-1R) blunts the glucoregulatory effects of RYGB in FXR +/+ but not in FXR -/- mice at 4 weeks after surgery.. These results suggest that FXR signaling is not required for the weight loss up to 16 weeks after RYGB. Although most of the improvements in glucose homeostasis are secondary to RYGB-induced weight loss in wild type mice, FXR signaling contributes to glycemic control after RYGB in a body weight-independent manner, which might be mediated by an FXR-GLP-1 axis during the early postoperative period. Topics: Animals; Blood Glucose; Body Composition; Body Weight; Diet, High-Fat; Energy Metabolism; Gastrectomy; Gastric Bypass; Glucagon-Like Peptide 1; Glucagon-Like Peptide-1 Receptor; Glycemic Control; Homeostasis; Insulin; Insulin Resistance; Male; Mice; Mice, Inbred C57BL; Mice, Knockout; Mice, Obese; Obesity; Receptors, Cytoplasmic and Nuclear; Weight Loss | 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 |
Visual stimulation with food pictures in the regulation of hunger hormones and nutrient deposition, a potential contributor to the obesity crisis.
Food cues affect hunger and nutritional choices. Omnipresent stimulation with palatable food contributes to the epidemics of obesity. The objective of the study was to investigate the impact of food cues on appetite-related hormones and to assess the functionality of the secreted hormones on macronutrient uptake in healthy subjects. Additionally, we aimed at verifying differences in the response of total and active ghrelin to stimulation with food pictures and to a meal followed by the stimulation. We were also interested in the identification of factors contributing to response to food cues. We recruited healthy, non-obese participants for two independent cross-over studies. During the first study, the subjects were presented random non-food pictures on the first day and pictures of foods on the second day of the study. Throughout the second study, following the picture session, the participants were additionally asked to drink a milkshake. Concentrations of blood glucose, triglycerides and hunger-related hormones were measured. The results showed that concentrations of several hormones measured in the blood are interdependent. In the case of ghrelin and gastric inhibitory peptide (GIP) as well as ghrelin and glucagon-like peptide-1 (GLP-1), this co-occurrence relies on the visual cues. Regulation of total ghrelin concentration following food stimulation is highly individual and responders showed upregulated total ghrelin, while the concentration of active ghrelin decreases following a meal. Protein content and colour intensity of food pictures reversely correlated with participants' rating of the pictures. We conclude that observation of food pictures influences the concentration of several appetite-related hormones. The close link of visual clues to physiological responses is likely of clinical relevance. Additionally, the protein content of displayed foods and green colour intensity in pictures may serve as a predictor of subjective attractiveness of the presented meal. Topics: Adolescent; Adult; Appetite; Blood Glucose; Choice Behavior; Cues; Feeding Behavior; Female; Gastric Inhibitory Polypeptide; Ghrelin; Glucagon-Like Peptide 1; Humans; Hunger; Insulin; Male; Nutrients; Obesity; Peptide YY; Photic Stimulation | 2020 |
Inhibition of Hepatic Bile Acid Uptake by Myrcludex B Promotes Glucagon-Like Peptide-1 Release and Reduces Obesity.
Bile acids are important metabolic signaling molecules. Bile acid receptor activation promotes body weight loss and improves glycemic control. The incretin hormone GLP-1 and thyroid hormone activation of T4 to T3 have been suggested as important contributors. Here, we identify the hepatic bile acid uptake transporter Na. Organic anion transporting polypeptide (OATP)1a/1b KO mice with or without reconstitution with human OATP1B1 in the liver were treated with the NTCP inhibitor Myrcludex B for 3.5 weeks after the onset of obesity induced by high fat diet-feeding. Furthermore, radiolabeled T4 was injected to determine the role of NTCP and OATPs in thyroid hormone clearance from plasma.. Inhibition of NTCP by Myrcludex B in obese Oatp1a/1b KO mice inhibited hepatic clearance of bile acids from portal and systemic blood, stimulated GLP-1 secretion, reduced body weight, and decreased (hepatic) adiposity. NTCP inhibition did not affect hepatic T4 uptake nor lead to increased thyroid hormone activation. Myrcludex B treatment increased fecal energy output, explaining body weight reductions amongst unaltered food intake and energy expenditure.. Pharmacologically targeting hepatic bile acid uptake to increase bile acid signaling is a novel approach to treat obesity and induce GLP1- secretion. Topics: Animals; Bile Acids and Salts; Diet, High-Fat; Disease Models, Animal; Female; Glucagon-Like Peptide 1; Humans; Lipopeptides; Liver; Liver-Specific Organic Anion Transporter 1; Male; Mice; Mice, Transgenic; Obesity; Organic Anion Transporters, Sodium-Dependent; Organic Cation Transport Proteins; Symporters | 2020 |
Postprandial increase in glucagon-like peptide-1 is blunted in severe heart failure.
The relationship between disturbances in glucose homeostasis and heart failure (HF) progression is bidirectional. However, the mechanisms by which HF intrinsically impairs glucose homeostasis remain unknown. The present study tested the hypothesis that the bioavailability of intact glucagon-like peptide-1 (GLP-1) is affected in HF, possibly contributing to disturbed glucose homeostasis. Serum concentrations of total and intact GLP-1 and insulin were measured after an overnight fast and 15 min after the ingestion of a mixed breakfast meal in 49 non-diabetic patients with severe HF and 40 healthy control subjects. Similarly, fasting and postprandial serum concentrations of these hormones were determined in sham-operated rats, and rats with HF treated with an inhibitor of the GLP-1-degrading enzyme dipeptidyl peptidase-4 (DPP4), vildagliptin, or vehicle for 4 weeks. We found that HF patients displayed a much lower increase in postprandial intact and total GLP-1 levels than controls. The increase in postprandial intact GLP-1 in HF patients correlated negatively with serum brain natriuretic peptide levels and DPP4 activity and positively with the glomerular filtration rate. Likewise, the postprandial increases in both intact and total GLP-1 were blunted in HF rats and were restored by DPP4 inhibition. Additionally, vehicle-treated HF rats displayed glucose intolerance and hyperinsulinemia, whereas normal glucose homeostasis was observed in vildagliptin-treated HF rats. We conclude that the postprandial increase in GLP-1 is blunted in non-diabetic HF. Impaired GLP-1 bioavailability after meal intake correlates with poor prognostic factors and may contribute to the establishment of a vicious cycle between glucose disturbance and HF development and progression. Topics: Aged; Animals; Blood Glucose; C-Peptide; Female; Glucagon-Like Peptide 1; Glucose Intolerance; Heart Failure; Humans; Insulin; Male; Middle Aged; Obesity; Peptide Fragments; Postprandial Period; Rats, Wistar | 2020 |
Long-Term β-galacto-oligosaccharides Supplementation Decreases the Development of Obesity and Insulin Resistance in Mice Fed a Western-Type Diet.
The gut microbiota might critically modify metabolic disease development. Dietary fibers such as galacto-oligosaccharides (GOS) presumably stimulate bacteria beneficial for metabolic health. This study assesses the impact of GOS on obesity, glucose, and lipid metabolism.. Following Western-type diet feeding (C57BL/6 mice) with or without β-GOS (7% w/w, 15 weeks), body composition, glucose and insulin tolerance, lipid profiles, fat kinetics and microbiota composition are analyzed. GOS reduces body weight gain (p < 0.01), accumulation of epididymal (p < 0.05), perirenal (p < 0.01) fat, and insulin resistance (p < 0.01). GOS-fed mice have lower plasma cholesterol (p < 0.05), mainly within low-density lipoproteins, lower intestinal fat absorption (p < 0.01), more fecal neutral sterol excretion (p < 0.05) and higher intestinal GLP-1 expression (p < 0.01). Fecal bile acid excretion is lower (p < 0.01) in GOS-fed mice with significant compositional differences, namely decreased cholic, α-muricholic, and deoxycholic acid excretion, whereas hyodeoxycholic acid increased. Substantial changes in microbiota composition, conceivably beneficial for metabolic health, occurred upon GOS feeding.. GOS supplementation to a Western-type diet improves body weight gain, dyslipidemia, and insulin sensitivity, supporting a therapeutic potential of GOS for individuals at risk of developing metabolic syndrome. Topics: Animals; Bile Acids and Salts; Body Weight; Diet, High-Fat; Diet, Western; Dietary Supplements; Dyslipidemias; Energy Metabolism; Feces; Gastrointestinal Microbiome; Glucagon-Like Peptide 1; Insulin Resistance; Male; Mice, Inbred C57BL; Obesity; Oligosaccharides; Sterols | 2020 |
Physical activity is associated with accelerated gastric emptying and increased ghrelin in obesity.
Rapid gastric emptying, increased food intake, and alterations in gastrointestinal hormones are associated with obesity. The effect of regular physical activity (PA) on food intake, gastric emptying (GE), gastric accommodation, and gastrointestinal (GI) hormones in adults with obesity remains unclear. Our aim was to compare, at time of presentation, weight trends, eating behavior, GE, and GI hormone levels among individuals with obesity who engage in regular PA compared to those who do not.. In 270 participants with obesity, we performed validated measurements of GI phenotypes: GE of solids and liquids, gastric volume (GV) during fasting and after consumption of 200 mL Ensure®, satiety by kcal intake (T-kcal) during a buffet meal, satiation (volume to fullness [VTF] and maximal tolerated volume [MTV]) of a liquid nutrient, and plasma levels of fasting and postprandial GLP-1, PYY, CCK, and ghrelin. Physical Activity Stages of Change Questionnaire was used to assess whether participants were regularly PA or not.. Physical activity is associated with lower BMI, but faster GE and higher postprandial ghrelin levels, two factors that are also associated with obesity. Topics: Adult; Body Mass Index; Case-Control Studies; Cholecystokinin; Exercise; Female; Gastric Emptying; Ghrelin; Glucagon-Like Peptide 1; Humans; Male; Obesity; Peptide YY; Postprandial Period; Satiation | 2020 |
A dysregulated bile acid-gut microbiota axis contributes to obesity susceptibility.
The composition of the bile acid (BA) pool is closely associated with obesity and is modified by gut microbiota. Perturbations of gut microbiota shape the BA composition, which, in turn, may alter important BA signaling and affect host metabolism.. We investigated BA composition of high BMI subjects from a human cohort study and a high fat diet (HFD) obesity prone (HF-OP) / HFD obesity resistant (HF-OR) mice model. Gut microbiota was analysed by metagenomics sequencing. GLP-1 secretion and gene regulation studies involved ELISA, qPCR, Western blot, Immunohistochemistry, and Immunofluorescence staining.. We found that the proportion of non-12-OH BAs was significantly decreased in the unhealthy high BMI subjects. The HF-OR mice had an enhanced level of non-12-OH BAs. Non-12-OH BAs including ursodeoxycholate (UDCA), chenodeoxycholate (CDCA), and lithocholate (LCA) were decreased in the HF-OP mice and associated with altered gut microbiota. Clostridium scindens was decreased in HF-OP mice and had a positive correlation with UDCA and LCA. Gavage of Clostridium scindens in mice increased the levels of hepatic non-12-OH BAs, accompanied by elevated serum 7α-hydroxy-4-cholesten-3-one (C4) levels. In HF-OP mice, altered BA composition was associated with significantly downregulated expression of GLP-1 in ileum and PGC1α, UCP1 in brown adipose tissue. In addition, we identified that UDCA attenuated the high fat diet-induced obesity via enhancing levels of non-12-OH BAs.. Our study highlights that dysregulated BA signaling mediated by gut microbiota contributes to obesity susceptibility, suggesting modulation of BAs could be a promising strategy for obesity therapy. Topics: Adipose Tissue, Brown; Animals; Body Mass Index; Chenodeoxycholic Acid; Cholestenones; Clostridiales; Cohort Studies; Diet, High-Fat; Disease Models, Animal; Disease Susceptibility; Gastrointestinal Microbiome; Gene Expression Regulation; Glucagon-Like Peptide 1; Humans; Ileum; Lithocholic Acid; Male; Metagenomics; Mice; Mice, Inbred C57BL; Obesity; Peroxisome Proliferator-Activated Receptor Gamma Coactivator 1-alpha; Uncoupling Protein 1; Ursodeoxycholic Acid | 2020 |
Combination of Lorcaserin and GLP-1/glucagon Coagonist Improves Metabolic Dysfunction in Diet Induced-obese Mice.
Obesity and diabetes are major metabolic disorders that progress to severe morbidity and mortality. Neuroendocrine mechanisms controlling energy balance indicate that combination therapies are needed to sustain weight loss. Lorcaserin was one of the approved therapies for the treatment of obesity, which is recently withdrawn because a safety clinical trial, shows an increased occurrence of cancer. Coagonist of glucagon-like-peptide-1 (GLP-1) and glucagon receptors is a novel investigational therapy demonstrated to have both anti-obesity and anti-diabetic effect. Here, we investigated the effect of combination of lorcaserin and a GLP-1 and glucagon receptors coagonist in diet-induced obese (DIO) mice model.. The diet-induced obese C57BL/6J mice were used to assess acute and chronic effect of lorcaserin, coagonist of GLP-1and glucagon receptors and their combination on food intake, body weight, and biochemical parameters.. In acute study, combination of lorcaserin and coagonist causes synergistic reductions in food intake and body weight. Repeated treatment of combination of lorcaserin and coagonist showed enhanced body weight loss over time, which is due to reduction in fat mass (subcutaneous, retroperitoneal, mesenteric and epididymal fat pad) compared to individual therapy. Also, suppression of locomotor activity seen with lorcaserin was not evident in combination with coagonist. No additive effect was observed in glucose tolerance (intraperitoneal glucose tolerance test or insulin tolerance test), serum lipids, hepatic lipids, and energy expenditure in combination group.. These data suggest that combination of lorcaserin and coagonist could be a better combination to induce body weight loss. Topics: Animals; Benzazepines; Body Weight; Diet, High-Fat; Energy Metabolism; Glucagon; Glucagon-Like Peptide 1; Glucose Tolerance Test; Liver; Male; Metabolic Diseases; Mice; Mice, Inbred C57BL; Mice, Obese; Obesity; Receptors, Glucagon; Weight Loss | 2020 |
The Role of the Bacterial Muramyl Dipeptide in the Regulation of GLP-1 and Glycemia.
The host's intestinal microbiota contributes to endocrine and metabolic responses, but a dysbiosis in this environment can lead to obesity and insulin resistance. Recent work has demonstrated a role for microbial metabolites in the regulation of gut hormones, including the metabolic hormone, glucagon-like peptide-1 (GLP-1). Muramyl dipeptide (MDP) is a bacterial cell wall component which has been shown to improve insulin sensitivity and glucose tolerance in diet-induced obese mice by acting through the nucleotide oligomerization domain 2 (NOD2) receptor. The purpose of this study was to understand the effects of MDP on GLP-1 secretion and glucose regulation. We hypothesized that MDP enhances glucose tolerance by inducing intestinal GLP-1 secretion through NOD2 activation. First, we observed a significant increase in GLP-1 secretion when murine and human L-cells were treated with a fatty acid MDP derivative (L18-MDP). Importantly, we demonstrated the expression of the NOD2 receptor in mouse intestine and in L-cells. In mice, two intraperitoneal injections of MDP (5 mg/kg body weight) caused a significant increase in fasting total GLP-1 in chow-fed mice, however this did not lead to an improvement in oral glucose tolerance. When mice were exposed to a high-fat diet, they eventually lost this MDP-induced GLP-1 release. Finally, we demonstrated in L-cells that hyperglycemic conditions reduce the mRNA expression of NOD2 and GLP-1. Together these findings suggest MDP may play a role in enhancing GLP-1 during normal glycemic conditions but loses its ability to do so in hyperglycemia. Topics: Acetylmuramyl-Alanyl-Isoglutamine; Animals; Dietary Fats; Female; Glucagon-Like Peptide 1; Humans; Hyperglycemia; Male; Mice; Nod2 Signaling Adaptor Protein; Obesity | 2020 |
A New Treatment for Chronic Hepatitis B and D Offers Novel Insights Into Obesity and Hepatic Steatosis.
Topics: Bile Acids and Salts; Glucagon-Like Peptide 1; Hepatitis B, Chronic; Humans; Lipopeptides; Obesity | 2020 |
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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 |
Hope in Hopeless Times: Gearing Up to Fight the Obesity Pandemic.
Topics: Glucagon-Like Peptide 1; Humans; Hyperphagia; Obesity; Pandemics | 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 |
Circadian GLP-1 Secretion in Mice Is Dependent on the Intestinal Microbiome for Maintenance of Diurnal Metabolic Homeostasis.
The incretin glucagon-like peptide 1 (GLP-1) is secreted by the intestinal L cell upon nutrient ingestion. GLP-1 also exhibits a circadian rhythm, with highest release at the onset of the feeding period. Similarly, microbial composition and function exhibit circadian rhythmicity with fasting-feeding. The circadian pattern of GLP-1 release was found to be dependent on the oral route of glucose administration and was necessary for the rhythmic release of insulin and diurnal glycemic control in normal male and female mice. In mice fed a Western (high-fat/high-sucrose) diet for 16 weeks, GLP-1 secretion was markedly increased but arrhythmic over the 24-h day, whereas levels of the other incretin, glucose-dependent insulinotropic polypeptide, were not as profoundly affected. Furthermore, the changes in GLP-1 secretion were shown to be essential for the maintenance of normoglycemia in this obesogenic environment. Analysis of the primary L-cell transcriptome, as well as of the intestinal microbiome, also demonstrated time-of-day- and diet-dependent changes paralleling GLP-1 secretion. Finally, studies in antibiotic-induced microbial depleted and in germ-free mice with and without fecal microbial transfer, provided evidence for a role of the microbiome in diurnal GLP-1 release. In combination, these findings establish a key role for microbiome-dependent circadian GLP-1 secretion in the maintenance of 24-h metabolic homeostasis. Topics: Animals; Circadian Rhythm; Dietary Carbohydrates; Dietary Fats; Female; Gastrointestinal Microbiome; Gene Expression Regulation; Glucagon-Like Peptide 1; Glucose; Homeostasis; Male; Mice; Mice, Inbred C57BL; Obesity; Sucrose | 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 |
Chronic high fat diet impairs glucagon like peptide-1 sensitivity in vagal afferents.
Dysfunction of the gut-brain axis is one of the potential contributors to the pathophysiology of obesity and is therefore a potential target for treatment. Vagal afferents innervating the gut play an important role in controlling energy homeostasis. There is an increasing evidence for the role of vagal afferents in mediating the anorexigenic effects of glucagon-like peptide-1 (GLP-1), an important satiety and incretin hormone. This study aimed to examine the effect of chronic high fat diet on GLP-1 sensitivity in vagal afferents. C57/BL6 mice were fed either a high-fat or low-fat diet for 6-8 weeks. To evaluate gastrointestinal afferent sensitivity and nodose neurons' response to GLP-1, extracellular afferent recordings and patch clamp were performed, respectively. Exendin-4 (Ex-4) was used as an agonist of the GLP-1 receptor. C-Fos Expression was examined as an indication of afferent input to the nucleus tractus solitarius (NTS). Food intake was monitored in real-time before and after Ex-4 treatment to monitor the consequence of the high fat diet on the satiating effect of GLP-1. In high fat fed (HFF) mice, GLP-1 caused lower activation of intestinal afferent nerves, and failed to potentiate mechanosensitive nerve responses compared to low fat fed (LFF). GLP-1 increased excitability in LFF and this effect was reduced in HFF neurons. Consistent with these findings on vagal afferent nerves, GLP-1 receptor stimulation given systemically, had a reduced satiating effect in HFF compared to LFF mice, and neuronal activation in the NTS was also reduced. The present study demonstrated chronic high fat diet impaired vagal afferent responses to GLP-1, resulting in impaired satiety signaling. GLP-1 sensitivity may account for the impairment of satiety signaling in obesity and thus a therapeutic target for obesity treatment. Topics: Animals; Diet, High-Fat; Glucagon-Like Peptide 1; Intestines; Male; Mice, Inbred C57BL; Neurons, Afferent; Obesity; Vagus Nerve | 2020 |
Early life overnutrition impairs plasticity of non-neuronal brainstem cells and drives obesity in offspring across development in rats.
The prevalence of adolescent obesity has increased dramatically, becoming a serious public health concern. While previous evidence suggests that in utero- and early postnatal overnutrition increases adult-onset obesity risk, the neurobiological mechanisms underlying this outcome are not well understood. Non-neuronal cells play an underestimated role in the physiological responses to metabolic/nutrient signals. Hypothalamic glial-mediated inflammation is now considered a contributing factor in the development and perpetuation of obesity; however, attention on the role of gliosis and microglia activation in other nuclei is still needed.. Here, we demonstrate that early life consumption of high-fat/sucrose diet (HFSD) is sufficient to increase offspring body weight, hyperleptinemia and potentially maladaptive cytoarchitectural changes in the brainstem dorsal-vagal-complex (DVC), an essential energy balance processing hub, across postnatal development. Our data demonstrate that pre- and postnatal consumption of HFSD result in increased body weight, hyperleptinemia and dramatically affects the non-neuronal landscape, and therefore the plasticity of the DVC in the developing offspring.. Current findings are very provocative, considering the importance of the DVC in appetite regulation, suggesting that HFSD-consumption during early life may contribute to subsequent obesity risk via DVC cytoarchitectural changes. Topics: Animals; Body Weight; Brain Stem; Diet, High-Fat; Dietary Sucrose; Female; Glucagon-Like Peptide 1; Insulin; Leptin; Male; Maternal Nutritional Physiological Phenomena; Neuronal Plasticity; Obesity; Overnutrition; Rats; Rats, Sprague-Dawley; Weight Gain | 2020 |
Downregulation of CTRP-3 by Weight Loss In Vivo and by Bile Acids and Incretins in Adipocytes In Vitro.
The adipokine CTRP-3 (C1q/TNF-related protein-3) exerts anti-inflammatory and anti-diabetic effects. Its regulation in obesity and during weight loss is unknown. Serum and adipose tissue (AT) samples were obtained from patients ( Topics: Adipocytes; Adipokines; Adult; Animals; Bariatric Surgery; Bile Acids and Salts; Cells, Cultured; Disease Models, Animal; Down-Regulation; Female; Gastrointestinal Agents; Glucagon-Like Peptide 1; Humans; Incretins; Male; Mice; Mice, Inbred BALB C; Mice, Knockout; Obesity; Tumor Necrosis Factors; Weight Loss | 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 |
Metabolic features and changes in glucose-induced serum glucagon-like peptide-1 levels in children with hypothalamic obesity.
Background Hypothalamic damage may alter glucagon-like peptide-1 (GLP-1) secretion and be involved in the pathogenesis of obesity. We aim to evaluate the metabolic features and the dynamic changes of GLP-1 levels during an oral glucose tolerance test (OGTT) in children with hypothalamic obesity (HO) compared with simple obesity controls. Methods Subjects included eight patients (six females, aged 9-16 years) with hypothalamo-pituitary tumors who later developed obesity and eight controls with simple obesity matched for age, body mass index (BMI), gender and puberty. We assessed the metabolic syndrome features, fat mass, severity of hyperphagia using a standardized questionnaire, and measured glucose, insulin and GLP-1 levels during a standard 75 g OGTT. Results Age, gender distribution, pubertal status and BMI-Z scores were not significantly different. Subjects with HO had higher fasting triglycerides (TG) than controls (128 vs. 94 mg/dL; p=0.05). Four HO subjects and three controls met the criteria for the metabolic syndrome. Fasting and 120 min post-glucose load GLP-1 levels were significantly higher in HO patients than in controls (21.9 vs. 19.7 pg/mL; p=0.025, 22.1 vs. 17.7 pg/mL; p=0.012). Patients with HO had significantly higher hyperphagia scores than in simple obese controls (13 vs. 2.5; p=0.012). Conclusions Patients with HO appear to have more metabolic complications and hyperphagia than controls with simple obesity. Impaired satiety may play an important role in HO. Fasting and glucose-induced serum GLP-1 concentrations seem to be altered in HO patients and could be a part of the pathogenesis of HO. Topics: Adolescent; Blood Glucose; Body Mass Index; Child; Female; Glucagon-Like Peptide 1; Glucose; Glucose Tolerance Test; Glycated Hemoglobin; Humans; Hyperphagia; Hypothalamic Diseases; Hypothalamic Neoplasms; Insulin; Male; Metabolic Syndrome; Obesity | 2020 |
The Unconventional Role for Gastric Volume in the Response to Bariatric Surgery for Both Weight Loss and Glucose Lowering.
To study the relationship between the amount of surgery-induced gastric volume reduction and long-term weight loss and glucose tolerance.. Vertical sleeve gastrectomy (VSG) has recently surpassed gastric bypass to become the most popular surgical intervention to induce sustained weight loss. Besides inducing significant weight loss, VSG also improves glucose tolerance. Although no clear correlation has been observed between the size of the residual stomach and sustained weight loss, this begs the question whether less aggressive gastric volume reduction may provide sufficient efficacy when weight loss is not the major goal of the surgical intervention.. A series of strategies to reduce gastric volume were developed and tested in Long Evans male rats, namely: VSG, Fundal (F)-Resection, Gastric Sleeve Plication (GSP), Fundal-Plication, and Fundal-Constrained.. All surgical interventions resulted in a reduction of gastric volume relative to sham, but none of the interventions were as effective as the VSG. Gastric volume was linearly correlated to increased gastric emptying rate as well as increased GLP-1 response. Overall, cumulative food intake was the strongest correlate to weight loss and was logarithmically related to gastric volume. Regression modeling revealed a nonlinear inverse relation between body weight reduction and gastric volume, confirming that VSG is the only effective long-term weight loss strategy among the experimental operations tested.. The data suggest a minimum threshold volume of the residual stomach that is necessary to induce sustained weight loss. Although all gastric volume interventions increased the GLP-1 response, none of the interventions, except VSG, significantly improved glucose tolerance. In conclusion, if weight loss is the primary goal of surgical intervention, significant volume reduction is required, and this most likely requires excising gastric tissue. Topics: Animals; Bariatric Surgery; Blood Glucose; Disease Models, Animal; Gastric Emptying; Glucagon-Like Peptide 1; Glucose Tolerance Test; Incretins; Male; Obesity; Organ Size; Rats; Rats, Long-Evans; Stomach; Weight Loss | 2020 |
An impaired glucagon-like peptide-1 response is associated with prediabetes in polycystic ovary syndrome with obesity.
Topics: Adult; Female; Glucagon-Like Peptide 1; Glucose Tolerance Test; Humans; Incretins; Obesity; Polycystic Ovary Syndrome; Prediabetic State | 2019 |
Glucose-Dependent Insulinotropic Polypeptide Receptor-Expressing Cells in the Hypothalamus Regulate Food Intake.
Ambiguity regarding the role of glucose-dependent insulinotropic polypeptide (GIP) in obesity arises from conflicting reports asserting that both GIP receptor (GIPR) agonism and antagonism are effective strategies for inhibiting weight gain. To enable identification and manipulation of Gipr-expressing (Gipr) cells, we created Gipr-Cre knockin mice. As GIPR-agonists have recently been reported to suppress food intake, we aimed to identify central mediators of this effect. Gipr cells were identified in the arcuate, dorsomedial, and paraventricular nuclei of the hypothalamus, as confirmed by RNAscope in mouse and human. Single-cell RNA-seq identified clusters of hypothalamic Gipr cells exhibiting transcriptomic signatures for vascular, glial, and neuronal cells, the latter expressing somatostatin but little pro-opiomelanocortin or agouti-related peptide. Activation of G Topics: Aged, 80 and over; Animals; Eating; Female; Gastric Inhibitory Polypeptide; Gene Knock-In Techniques; Glucagon-Like Peptide 1; Glucagon-Like Peptide-1 Receptor; Humans; Hypothalamus; Mice; Mice, Inbred C57BL; Mice, Transgenic; Neurons; Obesity; Receptors, Gastrointestinal Hormone | 2019 |
GPR40 full agonism exerts feeding suppression and weight loss through afferent vagal nerve.
GPR40/FFAR1 is a Gq protein-coupled receptor expressed in pancreatic β cells and enteroendocrine cells, and mediates insulin and incretin secretion to regulate feeding behavior. Several GPR40 full agonists have been reported to reduce food intake in rodents by regulating gut hormone secretion in addition to their potent glucose-lowering effects; however, detailed mechanisms of feeding suppression are still unknown. In the present study, we characterized T-3601386, a novel compound with potent full agonistic activity for GPR40, by using in vitro Ca2+ mobilization assay in Chinese hamster ovary (CHO) cells expressing FFAR1 and in vivo hormone secretion assay. We also evaluated feeding suppression and weight loss after the administration of T-3601386 and investigated the involvement of the vagal nerve in these effects. T-3601386, but not a partial agonist fasiglifam, increased intracellular Ca2+ levels in CHO cells with low FFAR1 expression, and single dosing of T-3601386 in diet-induced obese (DIO) rats elevated plasma incretin levels, suggesting full agonistic properties of T-3601386 against GPR40. Multiple doses of T-3601386, but not fasiglifam, in DIO rats showed dose-dependent weight loss accompanied by feeding suppression and durable glucagon-like peptide-1 elevation, all of which were completely abolished in Ffar1-/- mice. Immunohistochemical analysis in the nuclei of the solitary tract demonstrated that T-3601386 increased the number of c-Fos positive cells, which also disappeared in Ffar1-/- mice. Surgical vagotomy and drug-induced deafferentation counteracted the feeding suppression and weight loss induced by the administration of T-3601386. These results suggest that T-3601386 exerts incretin release and weight loss in a GPR40-dependent manner, and that afferent vagal nerves are important for the feeding suppression induced by GPR40 full agonism. Our novel findings raise the possibility that GPR40 full agonist can induce periphery-derived weight reduction, which may provide benefits such as less adverse effects in central nervous system compared to centrally-acting anti-obesity drugs. Topics: Animals; Blood Glucose; Calcium; Cell Line; CHO Cells; Cricetulus; Enteroendocrine Cells; Female; Glucagon-Like Peptide 1; Insulin; Insulin-Secreting Cells; Islets of Langerhans; Male; Mice; Obesity; Rats; Rats, Inbred F344; Rats, Sprague-Dawley; Rats, Wistar; Receptors, G-Protein-Coupled; Signal Transduction; Vagus Nerve; Weight Loss | 2019 |
The Iminosugar AMP-DNM Improves Satiety and Activates Brown Adipose Tissue Through GLP1.
Obesity is taking on worldwide epidemic proportions, yet effective pharmacological agents with long-term efficacy remain unavailable. Previously, we designed the iminosugar N-adamantine-methyloxypentyl-deoxynojirimycin (AMP-DNM), which potently improves glucose homeostasis by lowering excessive glycosphingolipids. Here we show that AMP-DNM promotes satiety and activates brown adipose tissue (BAT) in obese rodents. Moreover, we demonstrate that the mechanism mediating these favorable actions depends on oral, but not central, administration of AMP-DNM, which ultimately stimulates systemic glucagon-like peptide 1 (GLP1) secretion. We evidence an essential role of brain GLP1 receptors (GLP1r), as AMP-DNM fails to promote satiety and activate BAT in mice lacking the brain GLP1r as well as in mice treated intracerebroventricularly with GLP1r antagonist exendin-9. In conclusion, AMP-DNM markedly ameliorates metabolic abnormalities in obese rodents by restoring satiety and activating BAT through central GLP1r, while improving glucose homeostasis by mechanisms independent of central GLP1r. Topics: 1-Deoxynojirimycin; Adamantane; Adipose Tissue, Brown; Animals; Brain; Glucagon-Like Peptide 1; Glucose; Male; Mice; Mice, Inbred C57BL; Obesity; Rats; Rats, Wistar; Satiation; Signal Transduction | 2019 |
Glycemic effect of pancreatic preproglucagon in mouse sleeve gastrectomy.
Intestinally derived glucagon-like peptide-1 (GLP-1), encoded by the preproglucagon (Gcg) gene, is believed to function as an incretin. However, our previous work questioned this dogma and demonstrated that pancreatic peptides rather than intestinal Gcg peptides, including GLP-1, are a primary regulator of glucose homeostasis in normal mice. The objective of these experiments was to determine whether changes in nutrition or alteration of gut hormone secretion by bariatric surgery would result in a larger role for intestinal GLP-1 in the regulation of insulin secretion and glucose homeostasis. Multiple transgenic models, including mouse models with intestine- or pancreas tissue-specific Gcg expression and a whole-body Gcg-null mouse model, were generated to study the role of organ-specific GLP-1 production on glucose homeostasis under dietary-induced obesity and after weight loss from bariatric surgery (vertical sleeve gastrectomy; VSG). Our findings indicated that the intestine is a major source of circulating GLP-1 after various nutrient and surgical stimuli. However, even with the 4-fold increase in intestinally derived GLP-1 with VSG, it is pancreatic peptides, not intestinal Gcg peptides, that are necessary for surgery-induced improvements in glucose homeostasis. Topics: Animals; Bariatric Surgery; Blood Glucose; Diet, High-Fat; Disease Models, Animal; Gastrectomy; Gene Expression Profiling; Glucagon-Like Peptide 1; Humans; Insulin; Intestinal Mucosa; Male; Mice; Mice, Transgenic; Obesity; Pancreas; Weight Loss | 2019 |
Interaction of circulating GLP-1 and the response of the dorsolateral prefrontal cortex to food-cues predicts body weight development.
This study evaluated the impact of the interaction between the anorexigenic incretin hormone glucagon-like peptide-1 (GLP-1) and reward-related brain activity in the dorsolateral prefrontal cortex (DLPFC), a key area of behavioral control, on future weight loss in obese individuals.. We performed a weight loss-weight maintenance intervention study over 27 months. We applied an fMRI food-cue reactivity paradigm during which the participants were passively exposed to food pictures to evaluate neuronal activity in the DLPFC. Additionally, we measured concentrations of circulating GLP-1 levels during a standard oral glucose tolerance test. Phenotyping was performed consecutively before and after a 3-month low-calorie diet as well as after a randomized 12-month trial, investigating the effect of a combined behavioral intervention on body weight maintenance. Participants were then followed-up for another 12 months without further intervention.. Using voxel-wise linear mixed-effects regression analyses, we evaluated 56 measurements and identified a strong interaction between circulating, endogenous GLP-1 levels and DLPFC activity predicting body weight change over the total observation period (t = -6.17, p = 1.6 · 10. Our data demonstrate an interaction between a peripheral hormonal signal and central nervous activity as robust predictor of body weight change throughout the different periods of a long-term life-style intervention. The preeminent role of their interdependency compared to the partly ambivalent effects of the single components argues for integrative approaches to improve sensitivity and reliability of weight prediction conventionally based on individual biomarkers. Topics: Adult; Biomarkers; Body Mass Index; Body Weight; Brain; Caloric Restriction; Cues; Female; Glucagon-Like Peptide 1; Humans; Linear Models; Magnetic Resonance Imaging; Male; Middle Aged; Obesity; Photic Stimulation; Prefrontal Cortex; Weight Loss | 2019 |
Global transcriptome analysis of rat hypothalamic arcuate nucleus demonstrates reversal of hypothalamic gliosis following surgically and diet induced weight loss.
The central mechanisms underlying the marked beneficial metabolic effects of bariatric surgery are unclear. Here, we characterized global gene expression in the hypothalamic arcuate nucleus (Arc) in diet-induced obese (DIO) rats following Roux-en-Y gastric bypass (RYGB). 60 days post-RYGB, the Arc was isolated by laser-capture microdissection and global gene expression was assessed by RNA sequencing. RYGB lowered body weight and adiposity as compared to sham-operated DIO rats. Discrete transcriptome changes were observed in the Arc following RYGB, including differential expression of genes associated with inflammation and neuropeptide signaling. RYGB reduced gene expression of glial cell markers, including Gfap, Aif1 and Timp1, confirmed by a lower number of GFAP immunopositive astrocyte profiles in the Arc. Sham-operated weight-matched rats demonstrated a similar glial gene expression signature, suggesting that RYGB and dietary restriction have common effects on hypothalamic gliosis. Considering that RYGB surgery also led to increased orexigenic and decreased anorexigenic gene expression, this may signify increased hunger-associated signaling at the level of the Arc. Hence, induction of counterregulatory molecular mechanisms downstream from the Arc may play an important role in RYGB-induced weight loss. Topics: Adiposity; Animals; Arcuate Nucleus of Hypothalamus; Astrocytes; Biomarkers; Diet, High-Fat; Diet, Reducing; Eating; Gastric Bypass; Gene Expression Profiling; Gene Expression Regulation; Glial Fibrillary Acidic Protein; Gliosis; Glucagon-Like Peptide 1; Inflammation; Laser Capture Microdissection; Male; Neuropeptides; Obesity; Peptide YY; Rats; Rats, Sprague-Dawley; Sequence Analysis, RNA; Weight Loss | 2019 |
The homeostatic dynamics of feeding behaviour identify novel mechanisms of anorectic agents.
Better understanding of feeding behaviour will be vital in reducing obesity and metabolic syndrome, but we lack a standard model that captures the complexity of feeding behaviour. We construct an accurate stochastic model of rodent feeding at the bout level in order to perform quantitative behavioural analysis. Analysing the different effects on feeding behaviour of peptide YY3-36 (PYY3-36), lithium chloride, glucagon-like peptide 1 (GLP-1), and leptin shows the precise behavioural changes caused by each anorectic agent. Our analysis demonstrates that the changes in feeding behaviour evoked by the anorectic agents investigated do not mimic the behaviour of well-fed animals and that the intermeal interval is influenced by fullness. We show how robust homeostatic control of feeding thwarts attempts to reduce food intake and how this might be overcome. In silico experiments suggest that introducing a minimum intermeal interval or modulating upper gut emptying can be as effective as anorectic drug administration. Topics: Animals; Appetite Depressants; Eating; Feeding Behavior; Glucagon-Like Peptide 1; Homeostasis; Leptin; Male; Mice; Obesity; Peptide Fragments; Peptide YY; Rats | 2019 |
GLP-1 agonists for metabolic disorders in schizophrenia.
Topics: Adult; Antipsychotic Agents; Diabetes Mellitus; Glucagon-Like Peptide 1; Humans; Hypoglycemic Agents; Middle Aged; Obesity; Schizophrenia | 2019 |
Preproglucagon Neurons in the Nucleus of the Solitary Tract Are the Main Source of Brain GLP-1, Mediate Stress-Induced Hypophagia, and Limit Unusually Large Intakes of Food.
Topics: Animals; Brain; Eating; Electrophysiology; Female; Glucagon-Like Peptide 1; Glucose Tolerance Test; Immunohistochemistry; Male; Mice; Obesity; Proglucagon; Solitary Nucleus | 2019 |
Adrenomedullin and glucagon-like peptide-1 have additive effects on food intake in mice.
Adrenomedullin (ADM) is a vasoactive peptide expressed in several peripheral organs and known primarily for its beneficial vasoactive effects. However, ADM is also known to inhibit insulin secretion, and central administration of ADM has been shown to elicit anorexigenic effects. Here, we investigated if peripheral co-administration of ADM and glucagon-like peptide 1 (GLP-1) could subdue the hypoglycaemic effects of ADM while enhancing its anorectic properties. The effects of mono- and combination therapy of ADM and GLP-1 on appetite regulation and glucose homeostasis were assessed acutely in male NMRI mice for 12 h, while effects on glucose homeostasis were assessed by oral glucose tolerance tests (OGTT). While the monotherapy with GLP-1 and ADM resulted in modest anorexigenic effects, co-administration of the two peptides led to a marked additive reduction in food intake. Moreover, while OGTT-evoked blood glucose-excursions were significantly increased by ADM monotherapy, co-administration of ADM with a lower dose of GLP-1 normalized glucose excursions. In conclusion, we demonstrate additive anorectic effects of ADM and GLP-1, and that GLP-1 co-administration prevents ADM-induced impairment of glucose tolerance, suggesting that ADM could be potential anti-obesity target when combined with GLP-1 agonist therapy. Topics: Adrenomedullin; Animals; Appetite; Appetite Depressants; Blood Glucose; Drug Synergism; Eating; Glucagon-Like Peptide 1; Glucose Tolerance Test; Humans; Male; Mice; Obesity | 2019 |
Central Nervous System and Peripheral Hormone Responses to a Meal in Children.
Behavioral studies suggest that responses to food consumption are altered in children with obesity (OB).. To test central nervous system and peripheral hormone response by functional MRI and satiety-regulating hormone levels before and after a meal.. Cross-sectional study comparing children with OB and children of healthy weight (HW) recruited from across the Puget Sound region of Washington.. Children (9 to 11 years old; OB, n = 54; HW, n = 22), matched for age and sex.. Neural activation to images of high- and low-calorie food and objects was evaluated across a set of a priori appetite-processing regions that included the ventral and dorsal striatum, amygdala, substantia nigra/ventral tegmental area, insula, and medial orbitofrontal cortex. Premeal and postmeal hormones (insulin, peptide YY, glucagon-like peptide-1, active ghrelin) were measured.. In response to a meal, average brain activation by high-calorie food cues vs objects in a priori regions was reduced after meals in children of HW (Z = -3.5, P < 0.0001), but not in children with OB (z = 0.28, P = 0.78) despite appropriate meal responses by gut hormones. Although premeal average brain activation by high-calorie food cues was lower in children with OB vs children of HW, postmeal activation was higher in children with OB (Z = -2.1, P = 0.04 and Z = 2.3, P = 0.02, respectively). An attenuated central response to a meal was associated with greater degree of insulin resistance.. Our data suggest that children with OB exhibit an attenuated central, as opposed to gut hormone, response to a meal, which may predispose them to overconsumption of food or difficulty with weight loss. Topics: Appetite; Biomarkers; Brain; Case-Control Studies; Child; Cross-Sectional Studies; Female; Follow-Up Studies; Ghrelin; Glucagon-Like Peptide 1; Humans; Insulin; Magnetic Resonance Imaging; Male; Meals; Obesity; Peptide YY; Postprandial Period; Prognosis; Satiation | 2019 |
Alogliptin improves endothelial function by promoting autophagy in perivascular adipose tissue of obese mice through a GLP-1-dependent mechanism.
Perivascular adipose tissue (PVAT) regulates vascular function in a paracrine manner and the vasodilatory effect of PVAT on vessels is completely abolished in obesity. In addition, autophagy is required for maintaining biological function of PVAT and has been shown to be inhibited in obesity. The aim of this study was to explore whether alogliptin improves endothelial function by promoting autophagy in PVAT in obese mice.. C57BL/6 mice were maintained on high fat diet with or without alogliptin intervention for 3 months. Vasorelaxation function of thoracic aorta with or without PVAT was determined. Autophagy related protein level of p62 and LC3B, along with phosphorylated mTOR (p-mTOR) were evaluated. In addition, the effects of alogliptin on autophagy were also investigated in cultured adipocytes.. The presence of PVAT significantly impaired endothelium-dependent vasodilation in obese mice and alogliptin intervention corrected this defect. Autophagy in PVAT was decreased in obese mice and alogliptin intervention activated autophagy. Activating autophagy in PVAT improved endothelium-dependent vasodilation while blocking it in PVAT impaired vasodilation function. Further, addition of glucagon-like peptide-1 (GLP-1) but not alogliptin alone activated autophagy. Moreover, GLP-1 and alogliptin co-treatment did not show additive effect on activating autophagy.. These results revealed that promoting autophagy in PVAT improved endothelial function in response to alogliptin intervention. Additionally, the beneficial effect of alogliptin intervention on PVAT was GLP-1 dependent. Topics: Adipokines; Adipose Tissue; Animals; Aorta, Thoracic; Autophagy; Dipeptidyl-Peptidase IV Inhibitors; Disease Models, Animal; Endothelium, Vascular; Glucagon-Like Peptide 1; Male; Mice, Inbred C57BL; Nitric Oxide; Nitric Oxide Synthase Type III; Obesity; Paracrine Communication; Piperidines; Proto-Oncogene Proteins c-akt; Signal Transduction; Uracil; Vasodilation | 2019 |
Glucagon-like peptide 1 (GLP-1) drives postprandial hyperinsulinemic hypoglycemia in pregnant women with a history of Roux-en-Y gastric bypass operation.
The influential role of incretin hormones on glucose metabolism in patients with a history of Roux-en-Y gastric bypass (RYGB) has been investigated thoroughly, but there has been little examination of the effect of incretins and ectopic lipids on altered glucose profiles, especially severe hypoglycemia in pregnant women with RYGB.. In this prospective clinical study, an oral glucose tolerance test (OGTT), an intravenous glucose tolerance test (IVGTT), and continuous glucose monitoring (CGM) were conducted in 25 women with RYGB during pregnancy, 19 of normal weight (NW) and 19 with obesity (OB) between the 24th and the 28th weeks of pregnancy, and 3 to 6 months post-partum. Post-partum, the ectopic lipid content in the liver, heart, and skeletal muscle was analyzed using. RYGB patients presented with major fluctuations in glucose profiles, including a high occurrence of postprandial hyperglycemic spikes and hypoglycemic events during the day, as well as a high risk of hypoglycemic periods during the night (2.9 ± 1.1% vs. 0.1 ± 0.2% in the OB and vs. 0.8 ± 0.6% in the NW groups, p < 0.001). During the extended OGTT, RYGB patients presented with exaggerated expression of GLP-1, which was the main driver of the exaggerated risk of postprandial hypoglycemia in a time-lagged correlation analysis. Basal and dynamic GLP-1 levels were not related to insulin sensitivity, insulin secretion, or beta cell function and did not differ between pregnant women with and without GDM. A lower amount of liver fat (2.34 ± 5.22% vs.5.68 ± 4.42%, p = 0.015), which was positively related to insulin resistance (homeostasis model assessment of insulin resistance, HOMA-IR: rho = 0.61, p = 0.002) and beta-cell function (insulinogenic index: rho = 0.65, p = 0.001), was observed in the RYGB group after delivery in comparison to the OB group.. GLP-1 is mainly involved in the regulation of postprandial glucose metabolism and therefore especially in the development of postprandial hypoglycemia in pregnant RYGB patients, who are characterized by major alterations in glucose profiles, and thus in long-term regulation, multiple organ-related mechanisms, such as the lipid content in the liver, must be involved. Topics: Adult; Anastomosis, Roux-en-Y; Blood Glucose; Diabetes, Gestational; Female; Glucagon-Like Peptide 1; Glucose Tolerance Test; Humans; Hyperglycemia; Hyperinsulinism; Incretins; Insulin Resistance; Insulin-Secreting Cells; Lipid Metabolism; Lipids; Obesity; Pregnancy | 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 |
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 |
Two weeks of exercise training intensity on appetite regulation in obese adults with prediabetes.
No short-term exercise data exist testing whether training intensity modifies hormonal and perceived appetite in obese adults with prediabetes. Therefore, we compared the effects of short-term moderate-continuous (CONT) vs. high-intensity interval (INT) training on appetite regulation. Twenty-eight obese adults [age: 61.3 ± 1.5 yr; body mass index (BMI): 33.2 ± 1.1 kg/m Topics: Appetite; Appetite Regulation; Body Mass Index; Body Weight; Energy Intake; Energy Metabolism; Exercise; Fasting; Female; Ghrelin; Glucagon-Like Peptide 1; Glucose Tolerance Test; High-Intensity Interval Training; Humans; Male; Middle Aged; Obesity; Oxygen Consumption; Postprandial Period; Prediabetic State; Weight Loss | 2019 |
Impaired adaptation of energy intake induces severe obesity in aged mice on a high-fat diet.
High-fat diet (HFD) feeding induces inflammation in various tissues, including the nodose ganglion and hypothalamus, resulting in obesity and metabolic disorders. In this study, we investigated the effect of short-term HFD on aged and young mice. Aged mice easily gained weight during short-term HFD feeding, and required many days to adapt their energy intake. One-day HFD in aged mice induced inflammation in the distal colon, but not in the nodose ganglion or hypothalamus. The anorexic effect of glucagon-like peptide-1 (GLP-1) was attenuated in aged mice. Intraperitoneal administration of GLP-1 did not induce expression of genes that regulate feeding in the hypothalamus of aged mice. mRNA expression of the gene encoding the GLP-1 receptor (Glp1r) in the nodose ganglion was significantly lower in aged mice than in young mice. Our findings suggest that adaptation of energy intake regulation was attenuated in aged mice, causing them to become obese in response to short-term HFD feeding. Topics: Adaptation, Physiological; Age Factors; Aging; Animals; Colitis; Diet, High-Fat; Disease Models, Animal; Eating; Energy Intake; Energy Metabolism; Feeding Behavior; Gene Expression Regulation; Glucagon-Like Peptide 1; Hypothalamus; Inflammation Mediators; Male; Mice, Inbred C57BL; Nodose Ganglion; Obesity; Time Factors; Weight Gain | 2019 |
Activation of GLP-1 and Glucagon Receptors Regulates Bile Homeostasis Independent of Thyroid Hormone.
Balanced coagonists of glucagon-like peptide-1 (GLP-1) and glucagon receptors are emerging therapies for the treatment of obesity and diabetes. Such coagonists also regulate lipid metabolism, independent of their body weight lowering effects. Many actions of the coagonists are partly mediated by fibroblast growth factor 21 (FGF21) signaling, with the major exception of bile homeostasis. Since thyroid hormone is an important regulator of bile homeostasis, we studied the involvement of thyroid hormone in coagonist-induced changes in lipid and bile metabolism.. We evaluated the effect of a single dose of coagonist Aib2 C24 chimera2 at 150 to 10000 µg/kg on tetraiodothyronine (T4) and triiodothyronine (T3) in high-fat diet-induced obese (DIO) mice and chow-fed mice. Repeated dose treatment of coagonist (150 µg/kg, subcutaneously) was assessed in four mice models namely, on lipid and bile homeostasis in DIO mice, propylthiouracil (PTU)-treated DIO mice, methimazole (MTM)-treated DIO mice and choline-deficient, L-amino acid-defined, highfat diet (CDAHFD)-induced nonalcoholic steatohepatitis (NASH).. Single dose treatment of coagonist did not alter serum T3 and T4 in chow-fed mice and DIO mice. Coagonist treatment improved lipid metabolism and biliary cholesterol excretion. Chronic treatment of GLP-1 and glucagon coagonist did not alter serum T3 in hypothyroid DIO mice and CDAHFDinduced NASH. Coagonist increased serum T4 in DIO mice after 4 and 40 weeks of treatment, though no change in T4 levels was observed in hypothyroid mice or mice with NASH.. Our data demonstrate that coagonist of GLP-1 and glucagon receptors does not modulate bile homeostasis via thyroid signaling. Topics: Animals; Bile; Diet, High-Fat; Glucagon-Like Peptide 1; Liver; Male; Methimazole; Mice; Mice, Inbred C57BL; Non-alcoholic Fatty Liver Disease; Obesity; Propylthiouracil; Receptors, Glucagon; Thyroxine; Triglycerides; Triiodothyronine | 2019 |
Separate and Combined Effects of GIP and GLP-1 Infusions on Bone Metabolism in Overweight Men Without Diabetes.
The gut-derived incretin hormones glucose-dependent insulinotropic polypeptide (GIP) and glucagon-like peptide 1 (GLP-1) have been suggested to play a role in bone metabolism. Exogenous administration of GIP inhibits bone resorption, but the effect of GLP-1 is less clear. Furthermore, the combined effect of exogenous GIP and GLP-1 on bone metabolism is unknown.. To investigate the effect of separate and combined infusions of the incretin hormones GIP and GLP-1 on bone resorption and formation.. Randomized, double-blinded, placebo-controlled, crossover study including five study days.. Seventeen overweight/obese men.. On the first study day, a 50-g oral glucose tolerance test (OGTT) was performed. On the next four study days, isoglycemic IV glucose infusions (IIGI), mimicking the glucose excursions from the OGTT, were performed with concomitant infusions of GIP (4 pmol/kg/min), GLP-1 (1 pmol/kg/min), GIP+GLP-1 (4 and 1 pmol/kg/min, respectively), or placebo, respectively.. Changes in bone resorption assessed by measurements of carboxy-terminal type I collagen crosslinks (CTX) and in bone formation as assessed by procollagen type 1 N-terminal propeptide (P1NP) concentrations.. During the OGTT, CTX was significantly lowered by 54 ± 13% from baseline (mean ± SD) compared with 28 ± 12% during IIGI + saline (P < 0.0001). During IIGI+GLP-1 and IIGI+GIP, CTX was lowered by 65 ± 16% and 74 ± 9%, respectively, from baseline, whereas IGII+GIP+GLP-1 lowered CTX by 84 ± 4% from baseline. P1NP levels were unaffected by the interventions.. Our data suggest that GLP-1, like GIP, may be involved in regulation of bone resorption and that GIP and GLP-1 together have partially additive inhibitory effects. Topics: Adult; Bone and Bones; Bone Resorption; Collagen Type I; Cross-Over Studies; Double-Blind Method; Gastric Inhibitory Polypeptide; Glucagon-Like Peptide 1; Glucose Tolerance Test; Humans; Incretins; Male; Middle Aged; Obesity; Osteogenesis; Overweight; Peptide Fragments; Peptides; Procollagen; Random Allocation | 2019 |
The chronic administration of two novel long-acting
We here reported 2 novel Topics: Animals; Area Under Curve; Blood Glucose; Cell Survival; Cisplatin; Cross-Linking Reagents; Diabetes Mellitus; Dipeptides; Drug Administration Schedule; Energy Metabolism; Gastric Emptying; Glucagon-Like Peptide 1; Half-Life; Insulin; Kaolin; Male; Mice; Mice, Inbred ICR; Mice, Inbred NOD; Molecular Structure; Obesity; Rats; Rats, Sprague-Dawley; Xenopus | 2019 |
Novel nonapeptide GLP (28-36) amide derivatives with improved hypoglycemic and body weight lowering effects.
Glucagon-like peptide-1 (GLP-1) has emerged as a major therapeutic target for the treatment of type 2 diabetes. The nonapeptide GLP-1 (28-36) amide is one of the biological C-terminal products of GLP-1 modified by the neutral endopeptidase (NEP) 24.11 with limited hypoglycemic activity. In this study, we focused on the modification of GLP-1 (28-36) amide for the first time and synthesized a series of GLP-1 (28-36) amide analogues. Results of biological activity evaluation in INS-1 cell, STZ-induced diabetic and diet induced obesity (DIO) mice indicated that S3 as a promising candidate to treat type 2 diabetes and obesity. Topics: Adipocytes, Brown; Animals; Apoptosis; Body Weight; Cell Line, Tumor; Cell Survival; Diabetes Mellitus, Experimental; Diet, High-Fat; Glucagon-Like Peptide 1; Glucose Tolerance Test; Hypoglycemic Agents; Male; Mice; Mice, Inbred C57BL; Mice, Inbred ICR; Obesity; Oligopeptides; Oxidative Stress | 2019 |
Continuous feeding of a combined high-fat and high-sucrose diet, rather than an individual high-fat or high-sucrose diet, rapidly enhances the glucagon-like peptide-1 secretory response to meal ingestion in diet-induced obese rats.
Glucagon-like peptide-1 (GLP-1) is secreted by enteroendocrine L-cells in response to nutrient ingestion. To date, GLP-1 secretion in diet-induced obesity is not well characterized. We aimed to examine GLP-1 secretion in response to meal ingestion during the progression of diet-induced obesity and determinewhether a combined high-fat and high-sucrose (HFS) diet, an individual high-fat (HiFat), or a high-sucrose (HiSuc) diet affect adaptive changes in the postprandial GLP-1 response.. Rats were fed a control, HiFat diet (30% weight), HiSuc diet (40% weight), or HFS (30% fat and 40% sucrose) diet for 5 wk. Meal tolerance tests were conducted to determine postprandial glucose, insulin, and GLP-1 responses to standard (control) diet ingestion every 2 wk.. After 5 wk, body weight gain of the HiFat (232.3 ± 7.8 g; P = 0.021) and HFS groups (228.0 ± 7.8; P = 0.039), but not the HiSuc group (220.3 ± 7.9; P = 0.244), were significantly higher than that of the control group (200.7 ± 5.4 g). In meal tolerance tests after 2 wk, GLP-1 concentration was significantly elevated in the HFS group only (17.2 ± 2.6 pM; P < 0.001) in response to meal ingestions, but the HiFat group (16.6 ± 3.7 pM; P = 0.156) had a similar response as the HFS group. After 4 wk, GLP-1 concentrations were similarly elevated at 15min in the HFS (14.1 ± 4.4; P = 0.010), HiFat (13.2 ± 2.0; P < 0.001), and HiSuc (13.0 ± 3.3; P = 0.016) groups, but the HFS (9.8 ± 1.0; P = 0.019) and HiFat (8.3 ± 1.5; P = 0.010) groups also had significant elevation at 30min.. These results demonstrate that the continuous ingestion of excessive fat and sucrose rapidly enhances the GLP-1 secretory response to luminal nutrients, and the HiFat diet may have a potent effect compared with the HiSuc diet on GLP-1 secretory responses. The increment of postprandial GLP-1 and insulinsecretion may have a role in normalizing postprandial glycaemia and slowing the establishment of glucose intolerance. Topics: Animals; Blood Glucose; Diet; Diet, High-Fat; Dietary Fats; Dietary Sucrose; Disease Models, Animal; Energy Intake; Glucagon-Like Peptide 1; Insulin; Male; Meals; Obesity; Postprandial Period; Rats; Rats, Sprague-Dawley | 2019 |
Comparison of surgical versus diet-induced weight loss on appetite regulation and metabolic health outcomes.
Bariatric surgery is associated with significant and sustained weight loss and improved metabolic outcomes. It is unclear if weight loss alone is the main mechanism of improved metabolic health. The purpose of this trial was to compare indices of appetite regulation, insulin sensitivity and energy intake (EI) between participants achieving 10 kg of weight loss via Roux-en-Y Gastric Bypass (RYGB) or dietary restriction (DIET); intake of a very low calorie liquid diet (800 kcal/d; 40% protein, 40% fat, 20% carbohydrate that matched the post-RYGB dietary protocol). Adults qualifying for bariatric surgery were studied before and after 10 kg of weight loss (RYGB [n = 6]) or DIET [n = 17]). Appetite (hunger, satiety, and prospective food consumption [PFC]), appetite-related hormones, and metabolites (ghrelin, PYY, GLP-1, insulin, glucose, free fatty acids [FFA], and triglycerides [TG]) were measured in the fasting state and every 30 min for 180 min following breakfast. Participants were provided lunch to evaluate acute ad libitum EI, which was similarly reduced in both groups from pre to post weight loss. Fasting ghrelin was reduced to a greater extent following RYGB compared to DIET (P = 0.04). Area under the curve (AUC) for ghrelin (P = 0.01), hunger (P < 0.01) and PFC (P < 0.01) increased after DIET compared to RYGB, following 10 kg weight loss. Satiety AUC increased after RYGB and decreased after DIET (P < 0.01). Glucose and insulin (fasting and AUC) decreased in both groups. FFA increased in both groups, with a greater increase in AUC seen after RYGB versus DIET (P = 0.02). In summary, appetite-related indices were altered in a manner that, if maintained, may promote a sustained reduction in energy intake with RYGB compared to DIET. Future work with a larger sample size and longer follow-up will be important to confirm and extend these findings. Topics: Adult; Appetite; Appetite Regulation; Blood Glucose; Body Mass Index; Diet, Reducing; Energy Intake; Female; Gastric Bypass; Ghrelin; Glucagon-Like Peptide 1; Humans; Insulin; Insulin Resistance; Male; Middle Aged; Obesity; Peptide YY; Postprandial Period; Satiation; Weight Loss | 2019 |
Secretion of Gut Hormones and Expression of Sweet Taste Receptors and Glucose Transporters in a Rat Model of Obesity.
This study was undertaken to compare gut hormone secretion between high-fat-fed and control rats, and to examine the corresponding changes in the expression of sweet taste receptors and glucose transporters in the small intestine and hypothalamus.. Four-week-old male Sprague Dawley rats were fed a standard or high-fat diet for 8 weeks (10 in each group), followed by an oral glucose tolerance test (50% glucose solution, 2 g/kg). Blood was sampled for glucose, insulin, glucagon-like peptide-1 (GLP-1) and polypeptide YY (PYY) assays. One week later, small intestinal and hypothalamic tissue were analyzed for sweet taste receptor and glucose transporter expression by real-time PCR.. After oral glucose, plasma GLP-1 concentrations were higher in high-fat-fed than standard-fat-fed rats (group × time interaction, p < 0.01) with significant differences at t = 15 min (p < 0.01) and 30 min (p < 0.05). Plasma PYY concentrations were lower in high-fat-fed than control rats at t = 0, 15 min (p < 0.05, respectively) and 120 min (p < 0.01). There were no differences in the expression of sweet taste receptors or glucose transporters between high-fat-fed and control rats in the duodenum, ileum, or hypothalamus.. Changes in GLP-1 and PYY secretion after a high-fat diet appear unrelated to any changes in the expression of sweet taste receptors or glucose transporters. Impaired PYY secretion with high-fat feeding suggests that PYY analogues may provide a potential therapy in the treatment of obesity. Topics: Animals; Diet, High-Fat; Gastrointestinal Hormones; Gene Expression; Glucagon-Like Peptide 1; Glucose; Glucose Tolerance Test; Glucose Transport Proteins, Facilitative; Ileum; Insulin; Male; Obesity; Peptide YY; Rats; Rats, Sprague-Dawley; Receptors, G-Protein-Coupled; Taste; Taste Perception | 2019 |
Microbiota-Produced
The composition of the gastrointestinal microbiota and associated metabolites changes dramatically with diet and the development of obesity. Although many correlations have been described, specific mechanistic links between these changes and glucose homeostasis remain to be defined. Here we show that blood and intestinal levels of the microbiota-produced Topics: Animals; Cells, Cultured; Chemotaxis; Chromatography, Liquid; Diet, High-Fat; Enzyme-Linked Immunosorbent Assay; Flow Cytometry; Glucagon-Like Peptide 1; Glucose; Glucose Intolerance; In Situ Hybridization, Fluorescence; Insulin; Male; Mass Spectrometry; Mice; Mice, Knockout; Mice, Obese; Microbiota; Obesity; Oligopeptides | 2019 |
SCO-267, a GPR40 Full Agonist, Improves Glycemic and Body Weight Control in Rat Models of Diabetes and Obesity.
The GPR40/FFA1 receptor is a G-protein-coupled receptor expressed in the pancreatic islets and enteroendocrine cells. Here, we report the pharmacological profiles of (3 Topics: Animals; Blood Glucose; Body Weight; CHO Cells; Cricetulus; Cyclopropanes; Diabetes Mellitus, Experimental; Disease Models, Animal; Dogs; Eating; Glucagon-Like Peptide 1; Humans; Insulin Secretion; Islets of Langerhans; Male; Mice; Obesity; Piperidines; Propionates; Pyridines; Rats; Receptors, G-Protein-Coupled | 2019 |
Combined Amylin/GLP-1 pharmacotherapy to promote and sustain long-lasting weight loss.
A growing appreciation of the overlapping neuroendocrine mechanisms controlling energy balance has highlighted combination therapies as a promising strategy to enhance sustained weight loss. Here, we investigated whether amylin- and glucagon-like-peptide-1 (GLP-1)-based combination therapies produce greater food intake- and body weight-suppressive effects compared to monotherapies in both lean and diet-induced obese (DIO) rats. In chow-maintained rats, systemic amylin and GLP-1 combine to reduce meal size. Furthermore, the amylin and GLP-1 analogs salmon calcitonin (sCT) and liraglutide produce synergistic-like reductions in 24 hours energy intake and body weight. The administration of sCT with liraglutide also led to a significant enhancement in cFos-activation in the dorsal-vagal-complex (DVC) compared to mono-therapy, suggesting an activation of distinct, yet overlapping neural substrates in this critical energy balance hub. In DIO animals, long-term daily administration of this combination therapy, specifically in a stepwise manner, results in reduced energy intake and greater body weight loss over time when compared to chronic mono- and combined-treated groups, without affecting GLP-1 receptor, preproglucagon or amylin-receptor gene expression in the DVC. Topics: Animals; Anti-Obesity Agents; Blood Glucose; Body Weight; Calcitonin; Diet, High-Fat; Eating; Energy Intake; Energy Metabolism; Glucagon-Like Peptide 1; Islet Amyloid Polypeptide; Male; Obesity; Rats; Receptors, Glucagon; Weight Loss | 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 |
Comment on: GLP-1 and PYY
Topics: Animals; Diet; Food Preferences; Gastric Bypass; Glucagon-Like Peptide 1; Obesity; Rats | 2019 |
Hepatocyte-specific HIF-1α ablation improves obesity-induced glucose intolerance by reducing first-pass GLP-1 degradation.
The decrease in incretin effects is an important etiologic component of type 2 diabetes with unknown mechanisms. In an attempt to understand obesity-induced changes in liver oxygen homeostasis, we found that liver HIF-1α expression was increased mainly by soluble factors released from obese adipocytes, leading to decreased incretin effects. Deletion of hepatocyte HIF-1α protected obesity-induced glucose intolerance without changes in body weight, liver steatosis, or insulin resistance. In-depth mouse metabolic phenotyping revealed that obesity increased first-pass degradation of an incretin hormone GLP-1 with increased liver DPP4 expression and decreased sinusoidal blood flow rate, reducing active GLP-1 levels in peripheral circulation. Hepatocyte HIF-1α KO blocked these changes induced by obesity. Deletion of hepatocyte HIF-2α did not change liver DPP4 expression but improved hepatic steatosis. Our results identify a previously unknown pathway for obesity-induced impaired beta cell glucose response (incretin effects) and the development of glucose intolerance through inter-organ communications. Topics: Adipose Tissue; Animals; Basic Helix-Loop-Helix Transcription Factors; Diet, High-Fat; Dipeptidyl Peptidase 4; Fatty Liver; Glucagon-Like Peptide 1; Glucose; Hepatitis; Hepatocytes; Insulin Resistance; Liver; Male; Mice, Knockout; Obesity | 2019 |
Premeal Consumption of a Protein-Enriched, Dietary Fiber-Fortified Bar Decreases Total Energy Intake in Healthy Individuals.
A premeal load of protein can increase satiety and reduce energy intake. Dietary fiber also conveys metabolic benefits by modulating energy intake. We made a protein-enriched, dietary fiber-fortified bar (PFB) and aimed to investigate its effects on food intake and gut hormone secretion in healthy individuals.. Twenty subjects with normal glucose tolerance were enrolled. On three separate visits, the subjects received, in a randomized order, one of the following: a PFB containing 73 kcal with 10.7 g of protein and 12.7 g of dietary fiber; a usual bar (UB) containing the same calories as the PFB but only 0.9 g of protein and no dietary fiber; or water (control). After 15 minutes, the subjects had. Total energy intake, including the bar and the test meal, was significantly reduced with the PFB preload compared to the water (904.4±534.9 kcal vs. 1,075.0±508.0 kcal,. In healthy individuals, a premeal supplementation of PFB reduced total energy intake and decreased postprandial glucose excursion. This finding necessitates long-term studies regarding clinical use in obesity. Topics: Adult; Appetite; Blood Glucose; Dietary Fiber; Eating; Energy Intake; Female; Glucagon-Like Peptide 1; Healthy Volunteers; Humans; Insulin; Male; Meals; Obesity; Peptide YY; Postprandial Period; Proteins; Satiation; Young Adult | 2019 |
Enhanced postprandial glucagon-like peptide-1 secretion during obesity development has a protective role against glucose intolerance induction in rats.
Glucagon-like peptide-1 (GLP-1) is an incretin hormone that regulates postprandial glycaemic response by enhancing insulin secretion. We previously demonstrated that the postprandial GLP-1 response was enhanced during the development of diet-induced obesity in rats. However, the physiological relevance of the enhanced GLP-1 response remained unclear. We aimed to determine the role of endogenous GLP-1 during obesity development. Male Sprague-Dawley rats were given either a control diet or a high-fat/high-sucrose (HFS, 30 % fat and 40 % sucrose, weight basis) diet with or without continuous administration of the GLP-1 receptor antagonist, exendin (9-39) (Ex9, 100 µg/d), for 5 weeks. Meal tolerance tests (MTT) were performed to assess postprandial glucose, insulin and GLP-1 responses to a liquid diet administration (15 kcal (63 kJ)/10 ml per kg body weight) every 2 weeks. The AUC of postprandial glucose in the HFS group was similar to the control group in both MTT (P = 0·9665 and P = 0·3475, respectively), whereas AUC of postprandial GLP-1 (after 4 weeks,P = 0·0457) and of insulin (after 2 and 4 weeks, P = 0·0486 and P = 0·0110) was higher in the HFS group compared with the control group. In the Ex9 group, AUC of postprandial glucose (P = 0·0297 and P = 0·0486) was higher along with a lower insulin response compared with the HFS group (P = 0·0564 and P = 0·0281). These results suggest that enhancement of the postprandial GLP-1 response during obesity development has a role in maintaining a normal postprandial glycaemic response. Hence, enhancing endogenous GLP-1 secretion by certain materials could be a potential target for prevention of glucose intolerance. Topics: Animals; Blood Glucose; Body Weight; Energy Intake; Gastric Emptying; Glucagon-Like Peptide 1; Glucose Tolerance Test; Insulin; Male; Obesity; Postprandial Period; Rats; Rats, Sprague-Dawley | 2019 |
Long-Term Modulation of Appetitive Hormones and Sweet Cravings After Adjustable Gastric Banding and Roux-en-Y Gastric Bypass.
Roux-en-Y gastric bypass (RYGB) produces greater weight loss compared with a purely restrictive procedure such as laparoscopic adjustable gastric banding (LAGB).. The objective of this study was to quantify changes in hormones that regulate energy homeostasis and appetitive sensations before and after LAGB (n = 18) and RYGB (n = 38) in order to better understand the mechanisms underlying the greater weight loss after RYGB.. A standardized test meal was administered prior to surgery, at 6 months, and annually thereafter to year 2 after LAGB and year 4 after RYGB. Blood samples were obtained in the fasted state and 30, 60, 90, and 120 min post-meal.. Progressive increases in fasting PYY were observed after RYGB together with increases in postprandial area under the curve (AUC) levels that were unchanged after LAGB. GLP-1 AUC increased only after RYGB. There was a weight loss-related increase in fasting ghrelin levels after LAGB that was unchanged 1 year after RYGB despite greater percentage weight loss; ghrelin subsequently increased at years 2-4 post-RYGB. HOMA-IR decreased after both procedures but correlated with weight loss only after LAGB, whereas leptin correlated with weight loss in both groups. Sweet cravings decreased after RYGB.. A number of weight loss-independent changes in the gut hormonal milieu likely act in concert to promote a decrease in insulin resistance and greater weight loss efficacy after RYGB. A progressive change in hormone levels over time may reflect gut enteroplasticity after RYGB. A decrease in sweet cravings specific to RYGB may further promote superior weight loss outcomes. Topics: Appetite; Bariatric Surgery; Craving; Ghrelin; Glucagon-Like Peptide 1; Humans; Insulin; Obesity; Weight Loss | 2019 |
Gastric mucosal devitalization reduces adiposity and improves lipid and glucose metabolism in obese rats.
The gastric mucosa is an endocrine organ that regulates satiation pathways by expression of orexigenic and anorexigenic hormones. Vertical sleeve gastrectomy (VSG) excludes gastric mucosa and reduces gastric volume. Our study aimed to investigate the independent effects of altering gastric mucosa on obesity and its related comorbidities.. Gastric mucosa devitalization (GMD) of 70% of the stomach was achieved by argon plasma coagulation in a high-fat diet rat model and was compared with VSG and sham surgery. In an 8-week follow-up study, we quantified body weight, visceral adiposity, insulin resistance index, cholesterol profiles, and free fatty acid profiles by enzyme-linked immunosorbent assay (ELISA). Following a 2-hour oral glucose tolerance test, the kinetics of ghrelin, glucagon-like peptide-1, peptide YY, and serum and liver bile acid levels were measured. Liver lipid content was quantified by ELISA.. GMD resulted in significant reductions in body weight, visceral and subcutaneous adipose tissue, and hepatic steatosis as well as an improvement in lipid metabolism. GMD resulted in significant reductions in food intake and intestinal malabsorption of free fatty acids, both contributing to improved body composition and metabolic profile. Mechanistically, GMD resulted in a significant reduction in serum palmitate levels as well as an increase in serum and liver bile acid levels, known to alter glucose and lipid metabolism. Similar changes were noted when VSG rats were compared with sham surgery rats.. Devitalization of gastric mucosa, independent of altering gastric volume, was able to reduce obesity-related comorbidities. The gastric mucosa may be a potential target for treating obesity and its associated comorbidities. Topics: Adiposity; Animals; Argon Plasma Coagulation; Bile Acids and Salts; Blood Glucose; C-Reactive Protein; Cholesterol; Cholesterol, HDL; Cholesterol, LDL; Diet, High-Fat; Enzyme-Linked Immunosorbent Assay; Fatty Acids, Nonesterified; Gastrectomy; Gastric Mucosa; Ghrelin; Glucagon-Like Peptide 1; Glucose; Glucose Tolerance Test; Insulin Resistance; Interleukin-6; Intra-Abdominal Fat; Lipid Metabolism; Liver; Male; Obesity; Peptide YY; Rats; Rats, Sprague-Dawley; Stomach; Triglycerides | 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 |
Does endogenous GLP-1 affect resting energy expenditure and fuel selection in overweight and obese adults?
To investigate the association between fasting glucagon-like peptide 1 (GLP-1) levels and resting energy expenditure (REE), and respiratory quotient (RQ) in overweight and obese adults.. Study participants were enrolled at the Dietetic and Metabolic Unit, University of Pavia, Italy. Inclusion criteria were age ≥ 25 and ≤ 45 years, and body mass index (BMI) ≥ 25 and ≤ 35 kg/m. Thirty-seven participants were included (age 43.4 ± 1.6 years; BMI 30.6 ± 0.5 kg/m. In adults subjects with increased adiposity fasting, GLP-1 levels do not seem to play a role in the regulation of energy metabolism and in fuel selection. Topics: Adult; Basal Metabolism; Body Composition; Body Mass Index; Energy Metabolism; Fasting; Female; Glucagon-Like Peptide 1; Humans; Italy; Male; Middle Aged; Obesity; Overweight; Rest | 2018 |
Glucagon-like peptide-1 analog prevents obesity-related glomerulopathy by inhibiting excessive autophagy in podocytes.
To investigate the role of glucagon-like peptide-1 analog (GLP-1) in high-fat diet-induced obesity-related glomerulopathy (ORG). Male C57BL/6 mice fed a high-fat diet for 12 wk were treated with GLP-1 (200 μg/kg) or 0.9% saline for 4 wk. Fasting blood glucose and insulin and the expression of podocin, nephrin, phosphoinositide 3-kinase (PI3K), glucose transporter type (Glut4), and microtubule-associated protein 1A/1B-light chain 3 (LC3) were assayed. Glomerular morphology and podocyte foot structure were evaluated by periodic acid-Schiff staining and electron microscopy. Podocytes were treated with 150 nM GLP-1 and incubated with 400 μM palmitic acid (PA) for 12 h. The effect on autophagy was assessed by podocyte-specific Glut4 siRNA. Insulin resistance and autophagy were assayed by immunofluorescence and Western blotting. The high-fat diet resulted in weight gain, ectopic glomerular lipid accumulation, increased insulin resistance, and fusion of podophyte foot processes. The decreased translocation of Glut4 to the plasma membrane and excess autophagy seen in mice fed a high-fat diet and in PA-treated cultured podocytes were attenuated by GLP-1. Podocyte-specific Glut4 siRNA promoted autophagy, and rapamycin-enhanced autophagy worsened the podocyte injury caused by PA. Excess autophagy in podocytes was induced by inhibition of Glut4 translocation to the plasma membrane and was involved in the pathology of ORG. GLP-1 restored insulin sensitivity and ameliorated renal injury by decreasing the level of autophagy. Topics: Animals; Autophagy; Blood Glucose; Cell Line; Cytoprotection; Diet, High-Fat; Disease Models, Animal; Glucagon-Like Peptide 1; Glucose Transporter Type 4; Insulin; Insulin Resistance; Kidney Diseases; Male; Mice, Inbred C57BL; Obesity; Palmitic Acid; Podocytes; Protein Transport; Signal Transduction; Sirolimus | 2018 |
Combined gastrin releasing peptide-29 and glucagon like peptide-1 reduce body weight more than each individual peptide in diet-induced obese male rats.
To test the hypothesis that gastrin releasing peptide-29 (GRP-29) combined with glucagon like peptide-1 (7-36) (GLP-1 (7-36)) reduce body weight (BW) more than each of the peptides given individually, we infused the two peptides (0.5nmol/kg each) in the aorta of free feeding, diet-induced obese (DIO) male Sprague Dawley rats once daily for 25days and measured BW. We found that GRP-29 and GLP-1 reduce BW, GRP-29 reduced it more than GLP-1 and GRP-29+GLP-1 reduce BW more than each peptide given alone. This reduction was accompanied by decrease 24-hour food intake (normal rat chow), meal size (MS), duration of first meal and number of meals, and increase latency to the first meal, intermeal interval (IMI) and satiety ratio (IMI/MS, amount of food consumed per a unit of time). Furthermore, the peptides and their combination decreased 24-hour glucose levels. In conclusion, GRP-29+GLP-1 reduce BW more than each of the peptides given individually. Topics: Animals; Body Weight; Diet; Eating; Feeding Behavior; Gastrin-Releasing Peptide; Glucagon-Like Peptide 1; Male; Obesity; Peptide Fragments; Rats; Rats, Sprague-Dawley | 2018 |
Central administration of coagonist of GLP-1 and glucagon receptors improves dyslipidemia.
Coagonists of Glucagon-like peptide-1 (GLP-1) and glucagon receptors are under clinical investigation for treatment of obesity associated with diabetes. In addition to their role in glucose homeostasis, GLP-1 and glucagon modulate lipid metabolism. In this study, we have investigated the role of central GLP-1 receptor (GLP-1R) and glucagon receptor (GCGR) activation in regulation of lipid metabolism in cholesterol-fed hamsters. Hamsters were treated with coagonist alone (0.3 μg) or in combination with either GLP-1R antagonist (0.15 μg) or GCGR antagonist (0.3 μg) for 4 weeks by intracerebroventricular route (icv). A pair-fed control to coagonist was included in the experiment. In a separate experiment, vagotomized hamsters were treated with coagonist (0.3 μg) for four weeks. At the end of the treatment, plasma and hepatic lipids, bile homeostasis, and hepatic gene expression were determined. Coagonist treatment caused a reduction in plasma and liver lipids, and reduced triglyceride absorption from intestine. Also, hepatic triglyceride secretion, bile flow, and biliary cholesterol excretion were increased by the coagonist treatment. Coagonist treatment exhibited increased energy expenditure and reduced the expression of SREBP-1C, HMG-CoA reductase, SCD-1, FAS and ACC in liver. Increase in the expression of LDLR, ACOX1, CPT-1, PPAR-α, CYP7A1, ABCA1 and ABCB11 was also observed in liver. The effect of coagonist on lipids was partially blocked by either GLP-1R or GCGR antagonist. Coadministration of GLP-1R antagonist blocked the effect of coagonist on bile flow, while effect of coagonist on biliary cholesterol was blocked by co-administration of GCGR antagonist. Coagonist did not affect lipid metabolism in vagotomized hamsters. It appears that central administration of coagonist reduces dyslipidemia by activation of GLP-1R and GCGR, independent of its anorectic effect. Topics: Animals; Cholesterol; Dyslipidemias; Energy Metabolism; Glucagon; Glucagon-Like Peptide 1; Glucagon-Like Peptide-1 Receptor; Homeostasis; Lipid Metabolism; Liver; Male; Mesocricetus; Obesity; Receptors, Glucagon; Signal Transduction; Triglycerides | 2018 |
Gamma-aminobutyric Acid Enriched Rice Bran Diet Attenuates Insulin Resistance and Balances Energy Expenditure via Modification of Gut Microbiota and Short-Chain Fatty Acids.
In this study, gamma-aminobutyric acid (GABA) enriched rice bran (ERB) was supplemented to obese rats to investigate the attenuation of metabolic syndromes induced by high-fat diet. ERB-containing diet stimulated butyrate and propionate production by promoting Anaerostipes, Anaerostipes sp., and associated synthesizing enzymes. This altered short-chain fatty acid (SCFA) distribution further enhanced circulatory levels of leptin and glucagon-like peptide-1, controlling food intake by downregulating orexigenic factors. Together with the enhanced fatty acid β-oxidation highlighted by Prkaa2, Ppara, and Scd1 expression via AMPK signaling pathway and nonalcoholic fatty liver disease pathway, energy expenditure was positively modulated. Serum lipid compositions showed ERB supplement exhibited a more efficient effect on lowering serum sphingolipids, which was closely associated with the status of insulin resistance. Consistently, genes of Ppp2r3b and Prkcg, involved in the function of ceramides in blocking insulin action, were also downregulated following ERB intervention. Enriched GABA and phenolic acids were supposed to be responsible for the health-beneficial effects. Topics: Adipose Tissue; Animals; Ceramides; Diet; Diet, High-Fat; DNA; Energy Metabolism; Fatty Acids, Volatile; Food, Fortified; gamma-Aminobutyric Acid; Gastrointestinal Microbiome; Glucagon-Like Peptide 1; Insulin Resistance; Leptin; Liver; Male; Metabolic Syndrome; Obesity; Oryza; Rats; Rats, Sprague-Dawley; Seeds; Sphingolipids | 2018 |
Impact of weight loss achieved through a multidisciplinary intervention on appetite in patients with severe obesity.
The impact of lifestyle-induced weight loss (WL) on appetite in patients with obesity remains controversial. This study aimed to assess the short- and long-term impact of WL achieved by diet and exercise on appetite in patients with obesity. Thirty-five (22 females) adults with severe obesity (body mass index: 42.5 ± 5.0 kg/m Topics: Adult; Anaerobic Threshold; Appetite Regulation; Body Mass Index; Diet, Reducing; Exercise; Female; Glucagon-Like Peptide 1; Humans; Hunger; Life Style; Male; Middle Aged; Obesity; Obesity, Morbid; Patient Care Team; Peptide YY; Weight Loss | 2018 |
Diet switch and omega-3 hydroxy-fatty acids display differential hepatoprotective effects in an obesity/nonalcoholic fatty liver disease model in mice.
To study the effect of 18-hydroxy-eicosapentaenoic acid (18-HEPE) and 17-hydroxy-docosahexaenoic acid (17-HDHA) in a murine model of obesity/nonalcoholic fatty liver disease.. C57BL/6 mice were fed with standard chow diet (CD) or high-fat, fructose-enriched diet (HFD) for 16 wk. Then, three groups were treated for 14 d with either, diet switch (HFD for CD), 18-HEPE, or 17-HDHA. Weight and fasting glucose were recorded on a weekly basis. Insulin tolerance test was performed at the end of treatment. Histological analysis (HE and Masson's trichrome stain) and determination of serum insulin, glucagon, glucagon-like peptide 1 (GLP-1), glucose-dependent insulinotropic polypeptide, adiponectin and resistin were carried out as well as liver proteins by western blot.. Mice treated with hydroxy-fatty acids 18-HEPE and 17-HDHA displayed no weight loss or improved insulin sensitivity. However, these mice groups showed a significant amelioration on serum GLP-1, adiponectin and resistin levels. Also, a significant reduction on inflammatory infiltrate was observed at both portal and lobular zones. Furthermore, up-regulation of PPARα/γ protein levels was observed in liver tissue and it was associated with decreased levels of NF-κB also determined by western blot analysis. On the other hand, diet switch regimen resulted in a marked improvement in most parameters including: weight loss, increased insulin sensitivity, decreased steatosis, restored levels of insulin, glucagon, leptin, adiponectin and resistin. However, no significant changes were observed regarding inflammatory infiltrate in this last group.. 18-HEPE and 17-HDHA differentially exert hepatoprotective effects through up-regulation of nuclear receptors PPARα/γ and amelioration of serum adipokines profile. Topics: Animals; Blood Glucose; Diet, High-Fat; Dietary Carbohydrates; Disease Models, Animal; Docosahexaenoic Acids; Eicosapentaenoic Acid; Fructose; Glucagon-Like Peptide 1; Humans; Liver; Male; Mice; Mice, Inbred C57BL; Non-alcoholic Fatty Liver Disease; Obesity; Protective Agents; Weight Loss | 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 |
Plasma endocannabinoid levels in lean, overweight, and obese humans: relationships to intestinal permeability markers, inflammation, and incretin secretion.
Intestinal production of endocannabinoid and oleoylethanolamide (OEA) is impaired in high-fat diet/obese rodents, leading to reduced satiety. Such diets also alter the intestinal microbiome in association with enhanced intestinal permeability and inflammation; however, little is known of these effects in humans. This study aimed to 1) evaluate effects of lipid on plasma anandamide (AEA), 2-arachidonyl- sn-glycerol (2-AG), and OEA in humans; and 2) examine relationships to intestinal permeability, inflammation markers, and incretin hormone secretion. Twenty lean, 18 overweight, and 19 obese participants underwent intraduodenal Intralipid infusion (2 kcal/min) with collection of endoscopic duodenal biopsies and blood. Plasma AEA, 2-AG, and OEA (HPLC/tandem mass spectrometry), tumor necrosis factor-α (TNFα), glucagon-like peptide-1 (GLP-1), and glucose-dependent insulinotropic peptide (GIP) (multiplex), and duodenal expression of occludin, zona-occludin-1 (ZO-1), intestinal-alkaline-phosphatase (IAP), and Toll-like receptor 4 (TLR4) (by RT-PCR) were assessed. Fasting plasma AEA was increased in obese compared with lean and overweight patients ( P < 0.05), with no effect of BMI group or ID lipid infusion on plasma 2-AG or OEA. Duodenal expression of IAP and ZO-1 was reduced in obese compared with lean ( P < 0.05), and these levels related negatively to plasma AEA ( P < 0.05). The iAUC for AEA was positively related to iAUC GIP ( r = 0.384, P = 0.005). Obese individuals have increased plasma AEA and decreased duodenal expression of ZO-1 and IAP compared with lean and overweight subjects. The relationships between plasma AEA with duodenal ZO-1, IAP, and GIP suggest that altered endocannabinoid signaling may contribute to changes in intestinal permeability, inflammation, and incretin release in human obesity. Topics: Adult; Alkaline Phosphatase; Arachidonic Acids; Dietary Fats; Duodenum; Endocannabinoids; Female; Gastric Inhibitory Polypeptide; Gene Expression; Glucagon-Like Peptide 1; Glycerides; GPI-Linked Proteins; Humans; Incretins; Inflammation; Male; Obesity; Occludin; Oleic Acids; Overweight; Permeability; Polyunsaturated Alkamides; Thinness; Toll-Like Receptor 4; Tumor Necrosis Factor-alpha; Zonula Occludens-1 Protein | 2018 |
FTO genotype impacts food intake and corticolimbic activation.
Variants in the first intron of the fat mass and obesity-associated (FTO) gene increase obesity risk. People with "high-risk" FTO genotypes exhibit preference for high-fat foods, reduced satiety responsiveness, and greater food intake consistent with impaired satiety.. We sought central nervous system mechanisms that might underlie impaired satiety perception in people with a higher risk of obesity based on their FTO genotype.. We performed a cross-sectional study in a sample that was enriched for obesity and included 20 higher-risk participants with the AA (risk) genotype at the rs9939609 locus of FTO and 94 lower-risk participants with either the AT or TT genotype. We compared subjective appetite, appetite-regulating hormones, caloric intake at a buffet meal, and brain response to visual food cues in an extended satiety network using functional MRI scans acquired before and after a standardized meal.. Higher-risk participants reported less subjective fullness (χ2 = 7.48, P < 0.01), rated calorie-dense food as more appealing (χ2 = 3.92, P < 0.05), and consumed ∼350 more kilocalories than lower-risk participants (β = 348 kcal, P = 0.03), even after adjusting for fat or lean mass. Premeal, the higher-risk group had greater activation by "fattening" food images (compared with objects) in the medial orbital frontal cortex (β = 11.6; 95% CI: 1.5, 21.7; P < 0.05). Postmeal, the higher-risk subjects had greater activation by fattening (compared with nonfattening) food cues in the ventral tegmental area/substantia nigra (β = 12.8; 95% CI: 2.7, 23.0; P < 0.05), amygdala (β = 10.6; 95% CI: 0.7, 20.5; P < 0.05), and ventral striatum (β = 6.9; 95% CI: 0.2, 13.7; P < 0.05). Moreover, postmeal activation by fattening food cues within the preselected extended satiety network was positively associated with energy intake at the buffet meal (R2 = 0.29, P = 0.04) and this relation was particularly strong in the dorsal striatum (R2 = 0.28, P = 0.01), amygdala (R2 = 0.28, P = 0.03), and ventral tegmental area/substantia nigra (R2 = 0.27, P = 0.01).. The findings are consistent with a model in which allelic variants in FTO raise obesity risk through impaired central nervous system satiety processing, thereby increasing food intake. This study is registered at clinicaltrials.gov as NCT02483663. Topics: Adult; Alleles; Alpha-Ketoglutarate-Dependent Dioxygenase FTO; Appetite; Blood Glucose; Body Composition; Body Mass Index; Brain; Cross-Sectional Studies; Diet; Energy Intake; Female; Genotype; Genotyping Techniques; Ghrelin; Glucagon-Like Peptide 1; Humans; Magnetic Resonance Imaging; Male; Obesity; Polymorphism, Single Nucleotide; Satiation; Surveys and Questionnaires; Young Adult | 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 |
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 |
Appetite, Glycemia, and Entero-Insular Hormone Responses Differ Between Oral, Gastric-Remnant, and Duodenal Administration of a Mixed-Meal Test After Roux-en-Y Gastric Bypass.
To examine the effect of different feeding routes on appetite and metabolic responses after Roux-en-Y gastric bypass (RYGB).. A standard liquid meal was administered either orally, into the gastric remnant, or intraduodenally 6 months after RYGB. Changes in plasma glucose, insulin, glucagon-like peptide 1 (GLP-1), glucose-dependent insulinotropic peptide (GIP), peptide YY (PYY), and appetite were measured pre- and postprandially.. Postprandial GLP-1 and PYY responses were similar, whereas glucose, insulin, and GIP levels differed markedly after oral versus intraduodenal feeding. Intraduodenal feeding prompted an intermediate appetite response (i.e., between oral and intragastric). For postprandial glucose, insulin, and GIP levels, the intraduodenal route was more similar to the intragastric than the oral route. Intragastric administration did not evoke changes in appetite, glucose, or insulin; however, it slightly increased GLP-1 and PYY and moderately increased GIP.. Appetite and metabolic responses after RYGB depend on the route by which nutrients enter the gastrointestinal tract. Topics: Adult; Appetite; Blood Glucose; Duodenum; Enteral Nutrition; Female; Food; Gastric Bypass; Gastric Inhibitory Polypeptide; Gastric Mucosa; Gastrointestinal Hormones; Glucagon-Like Peptide 1; Humans; Insulin; Insulin Resistance; Male; Meals; Obesity; Peptide YY; Postprandial Period; Stomach | 2018 |
Barley β-glucan improves metabolic condition via short-chain fatty acids produced by gut microbial fermentation in high fat diet fed mice.
Dietary intake of barley β-glucan (BG) is known to affect energy metabolism. However, its underlying mechanism remains poorly understood because studies have presented inconsistent results, with both positive and negative effects reported in terms of satiety, energy intake, weight loss, and glycemic control. The objective of this study was to clarify the physiological role underlying the metabolic benefits of barley BG using a mouse model of high fat diet (HFD)-induced obesity. Male 4-wk-old C57BL/6J mice were fed an HFD with 20% barley flour containing either high BG (HBG; 2% BG) or low BG (LBG; 0.6% BG) levels under conventional and germ-free (GF) conditions for 12 wks. In addition, mice were fed either an HFD with 5% cellulose (HFC; high fiber cellulose) or 5% barley BG (HFB; high fiber β-glucan) for 12 wks. Then, metabolic parameters, gut microbial compositions, and the production of fecal short-chain fatty acids (SCFAs) were analyzed. The weight gain and fat mass of HBG-fed mice were lower than those of control mice at 16-wk-old. Moreover, the secretion of the gut hormones PYY and GLP-1 increased in HBG-fed mice, thereby reducing food intake and improving insulin sensitivity by changing the gut microbiota and increasing SCFAs (especially, butyrate) under conventional condition. These effects in HBG-fed mice were abolished under GF conditions. Moreover, the HFB diets also increased PYY and GLP-1 secretion, and decreased food intake compared with that in HFC-fed mice. These results suggest that the beneficial metabolic effects of barley BG are primary due to the suppression of appetite and improvement of insulin sensitivity, which are induced by gut hormone secretion promoted via gut microbiota-produced SCFAs. Topics: Actinobacteria; Animals; Appetite; beta-Glucans; Bifidobacterium; Diet, High-Fat; Fatty Acids, Volatile; Gastrointestinal Microbiome; Glucagon-Like Peptide 1; Hordeum; Intestinal Mucosa; Intestines; Male; Mice; Mice, Inbred C57BL; Obesity; Peptide YY | 2018 |
Enhanced Glucose Control Following Vertical Sleeve Gastrectomy Does Not Require a β-Cell Glucagon-Like Peptide 1 Receptor.
Bariatric surgeries, including vertical sleeve gastrectomy (VSG), resolve diabetes in 40-50% of patients. Studies examining the molecular mechanisms underlying this effect have centered on the role of the insulinotropic glucagon-like peptide 1 (GLP-1), in great part because of the ∼10-fold rise in its circulating levels after surgery. However, there is currently debate over the role of direct β-cell signaling by GLP-1 to mediate improved glucose tolerance following surgery. In order to assess the importance of β-cell GLP-1 receptor (GLP-1R) for improving glucose control after VSG, a mouse model of this procedure was developed and combined with a genetically modified mouse line allowing an inducible, β-cell-specific Topics: Animals; Diet, High-Fat; Disease Models, Animal; Gastroplasty; Glucagon-Like Peptide 1; Glucagon-Like Peptide-1 Receptor; Glucose Intolerance; Hypoglycemic Agents; Insulin; Insulin Resistance; Insulin Secretion; Insulin-Secreting Cells; Male; Mice, Inbred C57BL; Mice, Knockout; Mice, Transgenic; Obesity; Organ Specificity; Signal Transduction; Tissue Culture Techniques; Weight Loss | 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 |
A GLP-1:CCK fusion peptide harnesses the synergistic effects on metabolism of CCK-1 and GLP-1 receptor agonism in mice.
Combination approaches for the treatment of metabolic diseases such as obesity and diabetes are becoming increasingly relevant. Co-administration of a glucagon-like peptide-1 receptor (GLP-1R) agonist with a cholecystokinin receptor-1 (CCKR1) agonist exert synergistic effects on weight loss in obese rodents. Here, we report on the effects of a novel fusion peptide (C2816) comprised of a stabilized GLP-1R agonist, AC3174, and a CCKR1-selective agonist, AC170222. C2816 was constructed such that AC3174 was linked to the N-terminus of AC170222, thus preserving the C-terminal amide of the CCK moiety. In functional in vitro assays C2816 retained full agonism at GLP-1R and CCKR1 at lower potency compared to parent molecules, whereas a previously reported fusion peptide in the opposite orientation, (pGlu-Gln)-CCK-8/exendin-4, exhibited no activity at either receptor. Acutely, in vivo, C2816 increased cFos in key central nuclei relevant to feeding behavior, and reduced food intake in wildtype (WT), but less so in GLP-1R-deficient (GLP-1RKO), mice. In sub-chronic studies in diet-induced obese (DIO) mice, C2816 exerted superior reduction in body weight compared to co-administration of AC3174 and AC170222 albeit at a higher molar dose. These data suggest that the synergistic pharmacological effects of GLP-1 and CCK pathways can be harnessed in a single therapeutic peptide. Topics: Animals; Anti-Obesity Agents; Brain; Cholecystokinin; Drug Synergism; Eating; Glucagon-Like Peptide 1; Glucagon-Like Peptide-1 Receptor; Male; Mice; Mice, Inbred C57BL; Mice, Knockout; Obesity; Peptides; Rats, Sprague-Dawley; Receptor, Cholecystokinin A; Weight Loss | 2018 |
Duodenum Exclusion Alone Is Sufficient to Improve Glucose Metabolism in STZ-Induced Diabetes Rats.
Several studies have found that metabolic surgery can significantly improve glucose homeostasis; however, the intrinsic mechanisms remain unclear. Accumulating evidence suggests that duodenal bypass plays a crucial role in the treatment of type 2 diabetes mellitus (T2DM). Here, we aimed to evaluate the effect of duodenal reflux on glucose metabolism in T2DM.. A high-fat diet and low-dose streptozotocin (STZ) administration were used to induce T2DM in male rats, which were assigned to three experimental groups: sham operation (SO; n = 10), new duodenal-jejunal bypass (NDJB; n = 10), and new duodenal-jejunal bypass with a tube (NDJBT; n = 10). Weight, food intake, oral glucose tolerance test (OGTT) results, glucagon-like peptide 1 (GLP-1) levels, and histopathology were assessed before or after surgery. Plain abdominal radiography was performed 1 week after the operation.. Plain abdominal radiography indicated the occurrence of contrast agent reflux into the duodenum. The body weight and food intake in all three groups did not significantly differ before and after surgery. The NDJB and particularly the NDJBT groups exhibited better glucose tolerance, lower fasting blood glucose (FBG) levels, lower area under the curves for OGTT (AUC. Thus, exclusion of the duodenum alone and tube placement can effectively prevent duodenal reflux and improve glucose homeostasis, which further suggests that the duodenum plays an important role in T2DM. Topics: Animals; Blood Glucose; Diabetes Mellitus, Experimental; Diet, High-Fat; Duodenum; Gastric Bypass; Glucagon-Like Peptide 1; Male; Obesity; Rats | 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 |
Can prebiotics assist in the management of cognition and weight gain in schizophrenia?
Schizophrenia is among the top half of the 25 leading causes of disabilities worldwide with a 10-20 year decrease in life expectancy. Ineffective pharmacotherapy in the management of cognitive deficits and weight gain are known to be significant contributors; therefore interventions that may mitigate one, or both, of these parameters would be highly beneficial. Manipulation of the gut microbiome using dietary supplements such as prebiotics may be one such intervention. Preclinical studies have shown that a 2-4 week dietary supplementation with a prebiotic has beneficial effects on learning and memory, and prevents pro-inflammatory signals that are detrimental to cognitive processes. Furthermore, prebiotics influence metabolism, and in obesity they increase the expression of anorexigenic gut hormones such as peptide tyrosine tyrosine, glucagon-like peptide 1 and leptin, as well as decrease levels of orexigenic hormones such as ghrelin. Despite compelling evidence for the pro-cognitive and neuroprotective effects of prebiotics in rodents, their ability to alleviate cognitive deficits or enhance cognition needs to be evaluated in humans. Here we suggest that important symptoms associated with schizophrenia, such as cognitive impairment and weight gain, may benefit from concurrent prebiotic therapy. Topics: Cognition; Dietary Supplements; Gastrointestinal Microbiome; Ghrelin; Glucagon-Like Peptide 1; Humans; Leptin; Obesity; Peptide YY; Prebiotics; Schizophrenia; Weight Gain | 2018 |
Acute and Repeated Treatment with 5-PAHSA or 9-PAHSA Isomers Does Not Improve Glucose Control in Mice.
Fatty acid esters of hydroxylated fatty acids (FAHFAs) were discovered as a novel class of endogenous mammalian lipids whose profound effects on metabolism have been shown. In the current study, in vitro and in vivo the metabolic effects of two of these FAHFAs, namely palmitic acid-5- (or -9) -hydroxy-stearic acid (5- or 9-PAHSA, respectively) were profiled. In DIO mice fed with differentially composed low- or high-fat diets, acute and subchronic treatment with 5-PAHSA and 9-PAHSA alone, or in combination, did not significantly improve the deranged metabolic status. Neither racemic 5- or 9-PAHSA, nor the enantiomers were able to: (1) increase basal or insulin-stimulated glucose uptake in vitro, (2) stimulate GLP-1 release from GLUTag cells, or (3) induce GSIS in rat, mouse, or human islets or in a human pancreatic β cell line. Therefore, our data do not support the further development of PAHSAs or their derivatives for the control of insulin resistance and hyperglycemia. Topics: Animals; Diet, Fat-Restricted; Diet, High-Fat; Glucagon-Like Peptide 1; Glucose; HEK293 Cells; Humans; Hyperglycemia; Insulin Resistance; Islets of Langerhans; Mice; Mice, Inbred C57BL; Models, Animal; Obesity; Palmitic Acid; Rats; Rats, Sprague-Dawley; Stearic Acids | 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 |
Effects of prebiotic inulin-type fructans on blood metabolite and hormone concentrations and faecal microbiota and metabolites in overweight dogs.
Because obesity is associated with many co-morbidities, including diabetes mellitus, this study evaluated the second-meal effect of a commercial prebiotic, inulin-type fructans, and the effects of the prebiotic on faecal microbiota, metabolites and bile acids (BA). Nine overweight beagles were used in a replicated 3×3 Latin square design to test a non-prebiotic control (cellulose) against a low (equivalent to 0·5 % diet) and high dose (equivalent to 1·0 % diet) of prebiotic over 14-d treatments. All dogs were fed the same diet twice daily, with treatments provided orally via gelatin capsules before meals. On days 13 or 14 of each period, fresh faecal samples were collected, dogs were fed at 08.00 hours and then challenged with 1 g/kg body weight of maltodextrin in place of the 16.00 hours meal. Repeated blood samples were analysed for glucose and hormone concentrations to determine postprandial incremental AUC (IAUC) data. Baseline glucose, insulin and active glucagon-like peptide-1 levels were similar between all groups (P>0·10). Glucose and insulin IAUC after glucose challenge appeared lower following the high dose, but did not reach statistical relevance. Prebiotic intervention resulted in an increase in relative abundance of some Firmicutes and a decrease in the relative abundance of some Proteobacteria. Individual and total faecal SCFA were significantly increased (P<0·05) following prebiotic supplementation. Total concentration of excreted faecal BA tended to increase in dogs fed the prebiotic (P=0·06). Our results indicate that higher doses of inulin-type prebiotics may serve as modulators of gut microbiota, metabolites and BA pool in overweight dogs. Topics: Animals; Area Under Curve; Bile Acids and Salts; Blood Glucose; Colon; Dogs; Fatty Acids, Volatile; Feces; Female; Firmicutes; Fructans; Gastrointestinal Microbiome; Glucagon-Like Peptide 1; Insulin; Inulin; Obesity; Postprandial Period; Prebiotics; Proteobacteria | 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 |
Dietary soybean protein ameliorates high-fat diet-induced obesity by modifying the gut microbiota-dependent biotransformation of bile acids.
The consumption of soybean protein has well-known favorable metabolic effects (e.g., reduced body weight, body fat, hyperglycemia, insulin resistance, hepatic steatosis, and lipogenesis). These effects of soy protein have been linked to modulation by the gut microbiota; however, the dynamic interplay among these factors remains unclear. Accordingly, we examined the metabolic phenotype, intestinal BA pool, and the gut microbiome of male C57BL/6 mice that were randomized to receive either a regular high-fat diet (HFD) or HFD that contained soybean protein isolate (SPI) in place of dairy protein. The intake of SPI significantly reduced the HFD-induced weight gain and adipose tissue mass accumulation and attenuated hepatic steatosis. Along with an enhancement in the secretion of intestinal Glucagon-like peptide-1 (GLP-1), an enlarged cecal BA pool with an elevated secondary/primary BA ratio was observed in the mice that consumed SPI, while fecal BA excretion remained unaltered. SPI also elicited dramatic changes in the gut microbiome, characterized by an expansion of taxa that may be involved in the biotransformation of BAs. The observed effects were abolished in germ-free (GF) mice, indicating that they were dependent on the microbiota. These findings collectively indicate that the metabolic benefits of SPI under the HFD regime may arise from a microbiota-driven increase in BA transformation and increase in GLP-1 secretion. Topics: Animals; Bile Acids and Salts; Biodiversity; Diet, High-Fat; Dietary Supplements; Gastrointestinal Microbiome; Glucagon-Like Peptide 1; Intestinal Mucosa; Male; Metabolic Networks and Pathways; Metagenome; Metagenomics; Mice; Obesity; Soybean Proteins | 2018 |
An interesting cross-talk between the glucagon-like peptide-1 receptor axis and angiotensin receptor pathway for modulation of renal sodium handling in obesity.
Topics: Animals; Arterial Pressure; Glucagon-Like Peptide 1; Glucagon-Like Peptide-1 Receptor; Natriuresis; Obesity; Rats; Rats, Inbred OLETF; Receptors, Angiotensin; Sodium | 2018 |
Orosensory Detection of Dietary Fatty Acids Is Altered in CB₁R
Obesity is one of the major public health issues, and its prevalence is steadily increasing all the world over. The endocannabinoid system (ECS) has been shown to be involved in the intake of palatable food via activation of cannabinoid 1 receptor (CB₁R). However, the involvement of lingual CB₁R in the orosensory perception of dietary fatty acids has never been investigated. In the present study, behavioral tests on CB₁R Topics: Animals; Calcium Signaling; Cannabinoid Receptor Antagonists; CD36 Antigens; Dietary Fats; Fatty Acids; Food Preferences; Glucagon-Like Peptide 1; Glucagon-Like Peptide-1 Receptor; Linoleic Acid; Male; Mice, Knockout; Obesity; Proglucagon; Rapeseed Oil; Receptor, Cannabinoid, CB1; Receptors, G-Protein-Coupled; Rimonabant; RNA, Messenger; Taste; Taste Buds; Taste Perception | 2018 |
Restoration of GLP-1 secretion by Berberine is associated with protection of colon enterocytes from mitochondrial overheating in diet-induced obese mice.
L-cell dysfunction is reported for GLP-1 reduction in type 2 diabetes. However, the mechanism of dysfunction remains unknown. In this study, we examined mitochondrial function in the mechanistic study in diet-induced obese (DIO) mice.. C57BL/6 mice were fed a high-fat diet (HFD) for 16 weeks to establish the DIO model for GLP-1 reduction. The mice were then treated with berberine (BBR) (100 mg/kg/day) for 8 weeks to test the impact on GLP-1 expression. Mitochondrial activities of the colon enterocytes were compared among three groups of mice (lean, DIO, and DIO + BBR) at the end of treatment. Gut microbiota and short-chain fatty acids (SCFAs) were examined to understand the mitochondrial responses. A cellular model treated with palmitic acid (PA) was used in the mechanism study.. A reduction in GLP-1 expression was observed in DIO mice with mitochondrial stress responses in the colon enterocytes. The mitochondria exhibited cristae loss, membrane rupture, and mitochondrial swelling, which was observed with an increase in ATP abundance, complex I activity, and deficiency in the activities of complexes II and IV. Those changes were associated with dysbiosis and a reduction in SCFAs in the colon of DIO mice. In the cellular model, an increase in ATP abundance, loss of mitochondrial potential, and elevation of apoptosis were induced by PA. All of the alterations in DIO mice and the cellular model were attenuated by BBR.. The mitochondrial stress responses were observed in the colon enterocytes of DIO mice for GLP-1 reduction. The stress was prevented by BBR in the restoration of GLP-1 expression, in which BBR may act through direct and indirect mechanisms. Topics: Animals; Berberine; Colon; Diet, High-Fat; Enterocytes; Fatty Acids; Glucagon-Like Peptide 1; Insulin; Mice; Mitochondria; Obesity | 2018 |
24-h severe energy restriction impairs postprandial glycaemic control in young, lean males.
Intermittent energy restriction (IER) involves short periods of severe energy restriction interspersed with periods of adequate energy intake, and can induce weight loss. Insulin sensitivity is impaired by short-term, complete energy restriction, but the effects of IER are not well known. In randomised order, fourteen lean men (age: 25 (sd 4) years; BMI: 24 (sd 2) kg/m2; body fat: 17 (4) %) consumed 24-h diets providing 100 % (10 441 (sd 812) kJ; energy balance (EB)) or 25 % (2622 (sd 204) kJ; energy restriction (ER)) of estimated energy requirements, followed by an oral glucose tolerance test (OGTT; 75 g of glucose drink) after fasting overnight. Plasma/serum glucose, insulin, NEFA, glucagon-like peptide-1 (GLP-1), glucose-dependent insulinotropic peptide (GIP) and fibroblast growth factor 21 (FGF21) were assessed before and after (0 h) each 24-h dietary intervention, and throughout the 2-h OGTT. Homoeostatic model assessment of insulin resistance (HOMA2-IR) assessed the fasted response and incremental AUC (iAUC) or total AUC (tAUC) were calculated during the OGTT. At 0 h, HOMA2-IR was 23 % lower after ER compared with EB (P<0·05). During the OGTT, serum glucose iAUC (P<0·001), serum insulin iAUC (P<0·05) and plasma NEFA tAUC (P<0·01) were greater during ER, but GLP-1 (P=0·161), GIP (P=0·473) and FGF21 (P=0·497) tAUC were similar between trials. These results demonstrate that severe energy restriction acutely impairs postprandial glycaemic control in lean men, despite reducing HOMA2-IR. Chronic intervention studies are required to elucidate the long-term effects of IER on indices of insulin sensitivity, particularly in the absence of weight loss. Topics: Adult; Area Under Curve; Blood Glucose; Caloric Restriction; Energy Intake; Energy Metabolism; Fasting; Fibroblast Growth Factors; Gastric Inhibitory Polypeptide; Glucagon-Like Peptide 1; Glucose; Glucose Tolerance Test; Healthy Volunteers; Humans; Insulin; Insulin Resistance; Male; Obesity; Postprandial Period; Weight Loss; Young Adult | 2018 |
Resistant maltodextrin or fructooligosaccharides promotes GLP-1 production in male rats fed a high-fat and high-sucrose diet, and partially reduces energy intake and adiposity.
Increasing secretion and production of glucagon-like peptide-1 (GLP-1) by continuous ingestion of certain food components has been expected to prevent glucose intolerance and obesity. In this study, we examined whether a physiological dose (5% weight in diet) of digestion-resistant maltodextrin (RMD) has a GLP-1-promoting effect in rats fed a high-fat and high-sucrose (HFS) diet.. Rats were fed a control diet or the HFS (30% fat, 40% sucrose wt/wt) diet supplemented with 5% RMD or fructooligosaccharides (FOS) for 8 weeks or for 8 days in separated experiments. Glucose tolerance, energy intake, plasma and tissue GLP-1 concentrations, and cecal short-chain fatty acids concentrations were assessed.. After 4 weeks of feeding, HFS-fed rats had significantly higher glycemic response to oral glucose than control rats, but rats fed HFS + RMD/FOS did not (approx. 50% reduction vs HFS rats). HFS + RMD/FOS-fed rats had higher GLP-1 responses (~twofold) to oral glucose, than control rats. After 8 weeks, visceral adipose tissue weight was significantly higher in HFS-fed rats than control rats, while HFS + RMD/FOS rats had a trend of reduced gain (~50%) of the tissue weight. GLP-1 contents and luminal propionate concentrations in the large intestine increased (>twofold) by adding RMD/FOS to HFS. Eight days feeding of RMD/FOS-supplemented diets reduced energy intake (~10%) and enhanced cecal GLP-1 production (~twofold), compared to HFS diet.. The physiological dose of a prebiotic fiber promptly (within 8 days) promotes GLP-1 production in rats fed an obesogenic diet, which would help to prevent excess energy intake and fat accumulation. Topics: Adiposity; Animals; Appetite Depressants; Cecum; Diet, Western; Digestion; Dysbiosis; Energy Intake; Fatty Acids, Volatile; Fermentation; Gastrointestinal Contents; Gene Expression Regulation; Glucagon-Like Peptide 1; Intestinal Mucosa; Intra-Abdominal Fat; Male; Obesity; Oligosaccharides; Organ Size; Polysaccharides; Prebiotics; Rats, Sprague-Dawley | 2018 |
Design of Novel Exendin-Based Dual Glucagon-like Peptide 1 (GLP-1)/Glucagon Receptor Agonists.
Dual activation of the glucagon-like peptide 1 (GLP-1) and glucagon receptor has the potential to lead to a novel therapy principle for the treatment of diabesity. Here, we report a series of novel peptides with dual activity on these receptors that were discovered by rational design. On the basis of sequence analysis and structure-based design, structural elements of glucagon were engineered into the selective GLP-1 receptor agonist exendin-4, resulting in hybrid peptides with potent dual GLP-1/glucagon receptor activity. Detailed structure-activity relationship data are shown. Further modifications with unnatural and modified amino acids resulted in novel metabolically stable peptides that demonstrated a significant dose-dependent decrease in blood glucose in chronic studies in diabetic db/db mice and reduced body weight in diet-induced obese (DIO) mice. Structural analysis by NMR spectroscopy confirmed that the peptides maintain an exendin-4-like structure with its characteristic tryptophan-cage fold motif that is responsible for favorable chemical and physical stability. Topics: Amino Acid Sequence; Animals; Blood Glucose; Body Weight; Drug Design; Exenatide; Female; Glucagon; Glucagon-Like Peptide 1; Glucagon-Like Peptide-1 Receptor; Hypoglycemic Agents; Mice, Inbred C57BL; Mice, Obese; Molecular Docking Simulation; Obesity; Peptides; Structure-Activity Relationship; Swine; Venoms | 2017 |
Pancreatic α Cell-Derived Glucagon-Related Peptides Are Required for β Cell Adaptation and Glucose Homeostasis.
Pancreatic α cells may process proglucagon not only to glucagon but also to glucagon-like peptide-1 (GLP-1). However, the biological relevance of paracrine GLP-1 for β cell function remains unclear. We studied effects of locally derived insulin secretagogues on β cell function and glucose homeostasis using mice with α cell ablation and with α cell-specific GLP-1 deficiency. Normally, intestinal GLP-1 compensates for the lack of α cell-derived GLP-1. However, upon aging and metabolic stress, glucose tolerance is impaired. This was partly rescued with the DPP-4 inhibitor sitagliptin, but not with glucagon administration. In isolated islets from these mice, glucose-stimulated insulin secretion was heavily impaired and exogenous GLP-1 or glucagon rescued insulin secretion. These data highlight the importance of α cell-derived GLP-1 for glucose homeostasis during metabolic stress and may impact on the clinical use of systemic GLP-1 agonists versus stabilizing local α cell-derived GLP-1 by DPP-4 inhibitors in type 2 diabetes. Topics: Adaptation, Physiological; Aging; Animals; Diet, High-Fat; Diphtheria Toxin; Glucagon; Glucagon-Like Peptide 1; Glucagon-Secreting Cells; Glucose; Glucose Intolerance; Glucose Tolerance Test; Homeostasis; Humans; Insulin; Insulin Secretion; Insulin-Secreting Cells; Mice, Inbred C57BL; Mice, Knockout; Obesity; Proprotein Convertases; Rats; Stress, Physiological | 2017 |
Pancreas and liver uptake of new radiolabeled incretins (GLP-1 and Exendin-4) in models of diet-induced and diet-restricted obesity.
Radiolabeled GLP-1 and its analog Exendin-4, have been employed in diabetes and insulinoma. No protocol in conventional Diet-Induced Obesity (DIO), and Diet-Restricted Obesity (DRO), has been identified. Aiming to assess pancreatic beta cell uptake in DIO and DRO, a protocol was designed.. GLP-1-βAla-HYNIC and HYNIC-βAla-Exendin-4 were labeled with technetium-99m. Four Swiss mouse models were adopted: Controls (C), Alloxan Diabetes Controls (ADC), DIO and DRO. Biodistribution and ex-vivo planar imaging were documented.. Radiolabeling yield was in the range of 97% and both agents were hydrophilic. Fasting Blood Glucose (FBG) was 79.2±8.2mg/dl in C, 590.4±23.3mg/dl in ADC, 234.3±66.7mg/dl in DIO, and 96.6±9.3 in DRO (p=0.010). Biodistribution confirmed predominantly urinary excretion. DIO mice exhibited depressed uptake in liver and pancreas, for both radiomarkers, in the range of ADC. DRO only partially restored such values.. 1) Diet-induced obesity remarkably depressed beta cell uptake; 2) Restriction of obesity failed to normalize uptake, despite robust improvement of FBG; 3) HYNIC-βAla-Exendin-4 was the most useful marker; 4) Further studies are recommended in obesity and dieting, including bariatric surgery. Topics: Amino Acid Sequence; Animals; Biological Transport; Diet; Disease Models, Animal; Exenatide; Female; Glucagon-Like Peptide 1; Isotope Labeling; Liver; Mice; Obesity; Pancreas; Peptides; Tissue Distribution; Venoms | 2017 |
Daily supplementation of dietary protein improves the metabolic effects of GLP-1-based pharmacotherapy in lean and obese rats.
Glucagon-like peptide-1 (GLP-1) is an incretin hormone released from intestinal L-cells in response to food entering into the gastrointestinal tract. GLP-1-based pharmaceuticals improve blood glucose regulation and reduce feeding. Specific macronutrients, when ingested, may trigger GLP-1 secretion and enhance the effects of systemic sitagliptin, a pharmacological inhibitor of DPP-IV (an enzyme that rapidly degrades GLP-1). In particular, macronutrient constituents found in dairy foods may act as potent secretagogues for GLP-1, and acute preclinical trials show that ingestion of dairy protein may represent a promising adjunct behavioral therapy in combination with sitagliptin. To test this hypothesis further, chow-maintained or high-fat diet (HFD)-induced obese rats received daily IP injections of sitagliptin (6mg/kg) or saline in combination with a twice-daily 8ml oral gavage of milk protein concentrate (MPC; 80/20% casein/whey; 0.5kcal/ml), soy protein (non-dairy control; 0.5kcal/ml) or 0.9% NaCl for two months. Food intake and body weight were recorded every 24-48h; blood glucose regulation was examined at baseline and at 3 and 6.5weeks via a 2h oral glucose tolerance test (OGTT; 25% glucose; 2g/kg). MPC and soy protein significantly suppressed cumulative caloric intake in HFD but not chow-maintained rats. AUC analyses for OGTT show suppression in glycemia by sitagliptin with MPC or soy in chow- and HFD-maintained rats, suggesting that chronic ingestion of dairy or soy proteins may augment endogenous GLP-1 signaling and the glycemic- and food intake-suppressive effects of DPP-IV inhibition. Topics: Animal Feed; Animals; Anti-Obesity Agents; Diet, High-Fat; Dietary Proteins; Dietary Supplements; Dipeptidyl-Peptidase IV Inhibitors; Disease Models, Animal; Energy Intake; Glucagon-Like Peptide 1; Glucose Tolerance Test; Male; Obesity; Rats, Sprague-Dawley; Sitagliptin Phosphate | 2017 |
Timeline of changes in appetite during weight loss with a ketogenic diet.
Diet-induced weight loss (WL) leads to increased hunger and reduced fullness feelings, increased ghrelin and reduced satiety peptides concentration (glucagon-like peptide-1 (GLP-1), cholecystokinin (CCK) and peptide YY (PYY)). Ketogenic diets seem to minimise or supress some of these responses. The aim of this study was to determine the timeline over which changes in appetite occur during progressive WL with a ketogenic very-low-energy diet (VLED).. Thirty-one sedentary adults (18 men), with obesity (body mass index: 37±4.5 kg m. A significant increase in fasting hunger was observed by day 3 (2±1% WL), (P<0.01), 5% WL (12±8 days) (P<0.05) and wk 13 (17±2% WL) (P<0.05). Increased desire to eat was observed by day 3 (P<0.01) and 5% WL (P<0.05). Postprandial prospective food consumption was significantly reduced at wk 9 (16±2% WL) (P<0.01). Basal total PYY was significantly reduced at 10% WL (32±8 days) (P<0.05). Postprandial active GLP-1 was increased at 5% WL (P<0.01) and CCK reduced at 5 and 10% WL (P<0.01, for both) and wk 9 (P<0.001). Basal and postprandial AG were significantly increased at wk 13 (P<0.001, both).. WL with a ketogenic VLED transiently increases the drive to eat up to 3 weeks (5% WL). After that, and while participants are ketotic, a 10-17% WL is not associated with increased appetite. However, hunger feelings and AG concentrations increase significantly from baseline, once refeeding occurs. Topics: Adult; Appetite Regulation; Area Under Curve; Body Mass Index; Cholecystokinin; Diet, Ketogenic; Fasting; Female; Ghrelin; Glucagon-Like Peptide 1; Humans; Hunger; Longitudinal Studies; Male; Middle Aged; Norway; Obesity; Peptide YY; Postprandial Period; Satiety Response; Time Factors; Weight Loss | 2017 |
Berberine protects against diet-induced obesity through regulating metabolic endotoxemia and gut hormone levels.
Systemic inflammation, which can be induced by metabolic endotoxemia, and corresponding high‑fat diet‑mediated metabolic disorders are associated with gut microbiota. In the present study reverse transcription-polymerase chain reaction, immunofluorescence, pyrosequencing, ELISA and Oil Red O staining were performed to assess whether berberine can protect against diet-induced obesity, through modulating the gut microbiota and consequently improving metabolic endotoxemia and gastrointestinal hormone levels. Alterations in the gut microbiota induced by berberine resulted in a significant reduction in bacterial lipopolysaccharide levels in portal plasma. Levels of inflammatory and oxidative stress markers, as well as the mRNA expression levels of macrophage infiltration markers in visceral adipose tissue, were also reduced by berberine. Inhibition of the inflammatory response was associated with a reduction in intestinal permeability and an increase in the expression of tight junction proteins. In addition, berberine was reported to restore aberrant levels of gut hormones in the portal plasma, such as glucagon‑like peptide‑1 and ‑2, peptide YY, glucose‑dependent insulinotropic polypeptide and pancreatic polypeptide. The present findings indicated that berberine, through modulating gut microbiota, restored the gut barrier, reduced metabolic endotoxemia and systemic inflammation, and improved gut peptide levels in high‑fat diet‑fed rats. The present study suggests that berberine may be an effective therapeutic strategy for the treatment of obesity and insulin resistance. Topics: Animals; Berberine; Dietary Fats; Endotoxemia; Glucagon-Like Peptide 1; Glucagon-Like Peptide 2; Male; Obesity; Peptide YY; Rats; Rats, Sprague-Dawley | 2017 |
Monomeric GLP-1/GIP/glucagon triagonism corrects obesity, hepatosteatosis, and dyslipidemia in female mice.
Obesity is a major health threat that affects men and women equally. Despite this fact, weight-loss potential of pharmacotherapies is typically first evaluated in male mouse models of diet-induced obesity (DIO). To address this disparity we herein determined whether a monomeric peptide with agonism at the receptors for glucagon-like peptide 1 (GLP-1), glucose-dependent insulinotropic polypeptide (GIP), and glucagon is equally efficient in correcting DIO, dyslipidemia, and glucose metabolism in DIO female mice as it has been previously established for DIO male mice.. Female C57BL/6J mice and a cohort of fatmass-matched C57BL/6J male mice were treated for 27 days via subcutaneous injections with either the GLP-1/GIP/glucagon triagonist or PBS. A second cohort of C57BL/6J male mice was included to match the females in the duration of the high-fat, high-sugar diet (HFD) exposure.. Our results show that GLP-1/GIP/glucagon triple agonism inhibits food intake and decreases body weight and body fat mass with comparable potency in male and female mice that have been matched for body fat mass. Treatment improved dyslipidemia in both sexes and reversed diet-induced steatohepatitis to a larger extent in female mice compared to male mice.. We herein show that a recently developed unimolecular peptide triagonist is equally efficient in both sexes, suggesting that this polypharmaceutical strategy might be a relevant alternative to bariatric surgery for the treatment of obesity and related metabolic disorders. Topics: Adiposity; Animals; Diet, High-Fat; Dyslipidemias; Eating; Fatty Liver; Female; Gastric Inhibitory Polypeptide; Glucagon; Glucagon-Like Peptide 1; Male; Mice; Mice, Inbred C57BL; Obesity; Sex Factors | 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 |
An Optimized IES Method and Its Inhibitory Effects and Mechanisms on Food Intake and Body Weight in Diet-Induced Obese Rats: IES for Obesity.
This paper aims to optimize stimulation parameters and durations for intestinal electrical stimulation (IES) and to explore the effects and mechanisms of chronic IES with optimized methodology in obesity rats.. Sixteen diet-induced obese (DIO) rats were tested for food intake with four different sets of IES parameters each lasting 1 week. Then, another 12 DIO rats were used to test the effect of IES on food intake with different stimulation durations. Finally, 16 DIO rats were treated with IES or sham-IES for 4 weeks. Meal patterns, food intake, and body weight were observed. Mechanisms involving gastrointestinal motility, ghrelin, and glucagon-like peptide-1 (GLP-1) were studied.. (1) Acute IES with different parameters showed different inhibitory effects on food intake, and the most effective parameters were 0.6 s on, 0.9 s off, 80 Hz, 2 ms, and 4 mA with which 26.3% decrease in food intake was noted (p < 0.001). (2) IES with daily treatment of 12 h was most effective in suppressing food intake compared with 1 or 6 h. (3) Four-week IES reduced net weight by 10.9% (p < 0.05 vs. sham-IES) and epididymal fat pad weight by 13.9% (p < 0.001). (4) IES delayed gastric emptying (p < 0.001) and accelerated intestinal transit (p < 0.05). (5) IES increased both fasting and postprandial plasma levels of GLP-1 but not ghrelin.. Twelve-hour daily IES using optimized stimulation parameters reduces food intake and body weight in DIO rats by altering gastrointestinal motility and GLP-1. The IES methodology derived in this study may have a therapeutic potential for obesity. Topics: Animals; Body Weight; Diet, High-Fat; Eating; Electric Stimulation; Electric Stimulation Therapy; Fasting; Gastrointestinal Motility; Ghrelin; Glucagon-Like Peptide 1; Intestines; Male; Obesity; Postprandial Period; Rats; Rats, Sprague-Dawley | 2017 |
Roux-en-Y Gastric Bypass Improves Hepatic Glucose Metabolism Involving Down-Regulation of Protein Tyrosine Phosphatase 1B in Obese Rats.
This study was initiated to investigate the effects of Roux-en-Y gastric bypass (RYGB) surgery on hepatic glucose metabolism and hepatic expression of protein tyrosine phosphatase 1B (PTP1B) in obese rats.. Body weight, glucose, intraperitoneal glucose, insulin, and pyruvate tolerance tests were performed pre- and postoperatively, and plasma lipid, insulin and glucagon-like peptide 1 (GLP-1) were measured. The mRNA levels of G6Pase, Pepck, Gsk-3β and Gys-2, and the expression levels of PTP1B mRNA, protein, and other components of the insulin signaling pathway were measured by using RT-PCR and western blotting. The intracellular localization of PTP1B and hepatic glycogen deposition was also observed.. RYGB surgery-treated rats showed persistent weight loss, significantly improved glucose tolerance, pyruvate tolerance, and dyslipidemia, as well as increased insulin sensitivity, hepatic glycogen deposition and increased plasma GLP-1 in obese rats. RT-PCR analyses showed Pepck, G6Pase, and Gsk-3β mRNA to be significantly decreased, and Gys-2 mRNA to be significantly increased in liver tissue in the RYGB group (p < 0.05 vs. high-fat diet (HFD) or HFD + sham group); in addition, the expression of PTP1B were significantly decreased and insulin signaling were improved in the RYGB group (p < 0.05 vs. HFD or HFD + sham group).. RYGB can improve hepatic glucose metabolism and down-regulate PTP1B in obese rats. An increased circulating GLP-1 concentration may be correlated with the effects following RYGB in obese rats. Topics: Animals; Blood Glucose; Body Weight; Down-Regulation; Gastric Bypass; Glucagon-Like Peptide 1; Glucose; Insulin; Insulin Resistance; Liver; Male; Obesity; Protein Tyrosine Phosphatase, Non-Receptor Type 1; Rats; Rats, Sprague-Dawley; RNA, Messenger | 2017 |
Role of aquaporin-7 in ghrelin- and GLP-1-induced improvement of pancreatic β-cell function after sleeve gastrectomy in obese rats.
Glycerol is a key metabolite for lipid accumulation in insulin-sensitive tissues as well as for pancreatic insulin secretion. We examined the role of aquaporin-7 (AQP7), the main glycerol channel in β-cells, and AQP12, an aquaporin related to pancreatic damage, in the improvement of pancreatic function and steatosis after sleeve gastrectomy in diet-induced obese rats.. Male Wistar obese rats (n=125) were subjected to surgical (sham operation and sleeve gastrectomy) or dietary (pair-fed to the amount of food eaten by sleeve-gastrectomized animals) interventions. The tissue distribution and expression of AQPs in the rat pancreas were analyzed by real-time PCR, western blotting and immunohistochemistry. The effect of ghrelin isoforms and glucagon-like peptide 1 (GLP-1) on insulin secretion, triacylglycerol (TG) accumulation and AQP expression was determined in vitro in RIN-m5F β-cells.. Sleeve gastrectomy reduced pancreatic β-cell apoptosis, steatosis and insulin secretion. Lower ghrelin and higher GLP-1 concentrations were also found after bariatric surgery. Acylated and desacyl ghrelin increased TG content, whereas GLP-1 increased insulin release in RIN-m5F β-cells. Sleeve gastrectomy was associated with an upregulation of AQP7 together with a normalization of the increased AQP12 levels in the rat pancreas. Interestingly, ghrelin and GLP-1 repressed AQP7 and AQP12 expression in RIN-m5F β-cells. AQP7 protein was negatively correlated with intracellular lipid accumulation in acylated ghrelin-treated cells and with insulin release in GLP-1-stimulated β-cells.. AQP7 upregulation in β-cells after sleeve gastrectomy contributes, in part, to the improvement of pancreatic steatosis and insulin secretion by increasing intracellular glycerol used for insulin release triggered by GLP-1 rather than for ghrelin-induced TG biosynthesis. Topics: Animals; Aquaporins; Blotting, Western; Disease Models, Animal; Gastric Bypass; Ghrelin; Glucagon-Like Peptide 1; Immunohistochemistry; Insulin Resistance; Insulin-Secreting Cells; Male; Obesity; Rats; Rats, Wistar; Real-Time Polymerase Chain Reaction; Up-Regulation; Weight Loss | 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 |
Oleanolic acid derivative DKS26 exerts antidiabetic and hepatoprotective effects in diabetic mice and promotes glucagon-like peptide-1 secretion and expression in intestinal cells.
Glucagon-like peptide-1 (GLP-1) is an important target for diabetes therapy based on its key role in maintaining glucose and lipid homeostasis. This study was designed to investigate antidiabetic and hepatoprotective effects of a novel oleanolic acid derivative DKS26 in diabetic mice and elucidate its underlying GLP-1 related antidiabetic mechanisms in vitro and in vivo.. The therapeutic effects of DKS26 were investigated in streptozotocin (STZ)-induced and db/db diabetic mouse models. Levels of plasma glucose, glycosylated serum protein (GSP), lipid profiles, insulin, alanine aminotransferase (ALT) and aspartate aminotransferase (AST), oral glucose tolerance (OGT), pancreatic islets and hepatic histopathological morphology, liver lipid levels and expression of pro-inflammatory cytokines were assessed. Intestinal NCI-H716 cells and diabetic models were used to further validate its potential GLP-1-related antidiabetic mechanisms.. DKS26 treatment (100 mg·kg. DKS26 exerted hypoglycaemic, hypolipidaemic and islets protective effects, which were associated with an enhanced release and expression of GLP-1 mediated by the activation of the cAMP/PKA signalling pathway, and alleviated hepatic damage by reducing liver lipid levels and inflammation. These findings firmly identified DKS26 as a new viable therapeutic option for diabetes control. Topics: Alanine Transaminase; Animals; Aspartate Aminotransferases; Blood Glucose; Body Weight; Cell Line; Cyclic AMP; Cyclic AMP-Dependent Protein Kinases; Diabetes Mellitus, Experimental; Enteroendocrine Cells; Glucagon-Like Peptide 1; Humans; Hypoglycemic Agents; Lipid Metabolism; Liver; Male; Mice; Obesity; Oleanolic Acid; Pancreas; Protective Agents | 2017 |
Exogenous glucagon-like peptide-1 reduces body weight and cholecystokinin-8 enhances this reduction in diet-induced obese male rats.
The sites of action regulating meal size (MS) and intermeal interval (IMI) length by glucagon like peptide-1 (7-36) (GLP-1 (7-36)) and cholecystokinin-8 (CCK-8) reside in the areas supplied by the two major branches of the abdominal aorta, celiac and cranial mesenteric arteries. We hypothesized that infusing GLP-1 near those sites reduces body weight (BW) and adding CCK-8 to this infusion enhances the reduction. Here, we measured BW in diet-induced obese (DIO) male rats maintained and tested on normal rat chow and infused with saline, GLP-1 (0.5nmol/kg) and GLP-1+CCK-8 (0.5nmol/kg each) in the aorta once daily for 21days. We found that GLP-1 and GLP-1+CCK-8 decrease BW relative to saline vehicle and GLP-1+CCK-8 reduced it more than GLP-1 alone. Reduction of BW by GLP-1 alone was accompanied by decreased 24-h food intake, first MS, duration of first meal and number of meals, and an increase in latency to first meal. Reduction of BW by the combination of the peptides was accompanied by decrease 24-h food intake, first MS, duration of first meal and number of meals, and increase in the IMI length, satiety ratio and latency to first meal. In conclusion, GLP-1 reduces BW and CCK-8 enhances this reduction if the peptides are given near their sites of action. Topics: Animals; Anti-Obesity Agents; Aorta; Cholecystokinin; Diet, High-Fat; Disease Models, Animal; Drug Therapy, Combination; Eating; Feeding Behavior; Glucagon-Like Peptide 1; Male; Obesity; Peptide Fragments; Rats, Sprague-Dawley; Satiation; Time Factors; Weight Loss | 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 |
Glucagon-like peptide-1 reduces pancreatic β-cell mass through hypothalamic neural pathways in high-fat diet-induced obese rats.
We examined whether glucagon-like peptide-1 (GLP-1) affects β-cell mass and proliferation through neural pathways, from hepatic afferent nerves to pancreatic efferent nerves via the central nervous system, in high-fat diet (HFD)-induced obese rats. The effects of chronic administration of GLP-1 (7-36) and liraglutide, a GLP-1 receptor agonist, on pancreatic morphological alterations, c-fos expression and brain-derived neurotrophic factor (BDNF) content in the hypothalamus, and glucose metabolism were investigated in HFD-induced obese rats that underwent hepatic afferent vagotomy (VgX) and/or pancreatic efferent sympathectomy (SpX). Chronic GLP-1 (7-36) administration to HFD-induced obese rats elevated c-fos expression and BDNF content in the hypothalamus, followed by a reduction in pancreatic β-cell hyperplasia and insulin content, thus resulting in improved glucose tolerance. These responses were abolished by VgX and SpX. Moreover, administration of liraglutide similarly activated the hypothalamic neural pathways, thus resulting in a more profound amelioration of glucose tolerance than native GLP-1 (7-36). These data suggest that GLP-1 normalizes the obesity-induced compensatory increase in β-cell mass and glucose intolerance through a neuronal relay system consisting of hepatic afferent nerves, the hypothalamus, and pancreatic efferent nerves. Topics: Animals; Brain-Derived Neurotrophic Factor; Cell Proliferation; Cell Size; Diet, High-Fat; Glucagon-Like Peptide 1; Glucose; Glucose Intolerance; Hypothalamus; Injections, Intraperitoneal; Insulin-Secreting Cells; Liraglutide; Neural Pathways; Obesity; Proto-Oncogene Proteins c-fos; Rats; Rats, Sprague-Dawley; Sympathectomy; Vagotomy | 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 |
Canagliflozin potentiates GLP-1 secretion and lowers the peak of GIP secretion in rats fed a high-fat high-sucrose diet.
The glucose-induced secretion of incretins, including glucagon-like peptide-1 (GLP-1) and glucose-dependent insulinotropic polypeptide (GIP), is dependent on luminal glucose levels and transport of glucose via the sodium-glucose transporter 1 (SGLT1) in the small intestine. Because GLP-1 and GIP function in decreasing and increasing the body weight, respectively, we aimed to analyze the effect of transient inhibition of SGLT1 by canagliflozin on incretin secretion in an obese rat model. Male Sprague-Dawley rats were maintained on a high-fat high-sucrose diet for 6-7 weeks, and plasma GLP-1 and GIP levels were measured during an oral glucose tolerance test (OGTT). In addition, GLP-1 secretion was examined in a murine GLP-1 producing enteroendocrine cell line, GLUTag. Concomitant administration of 10 mg/kg canagliflozin with glucose loading suppressed glucose excursion, increased total GLP-1 levels, and reduced total GIP levels in systemic circulation, as revealed in the OGTT. Total and active GLP-1 levels were increased in portal blood, whereas total and active GIP levels tended to be decreased 15 min after the administration of canagliflozin with glucose. Canagliflozin (at 0.1-30 μM) did not directly affect release of GLP-1 in vitro. These results suggest that the oral administration of canagliflozin suppresses GIP secretion via the inhibition of SGLT1 in the upper part of the intestine and enhances GLP-1 secretion by increasing the glucose delivery to the lower part of the small intestine in an obese rodent model. Topics: Animals; Blood Glucose; Canagliflozin; Cell Line; Diet, High-Fat; Dietary Carbohydrates; Gastric Inhibitory Polypeptide; Glucagon-Like Peptide 1; Glucose; Hypoglycemic Agents; Incretins; Insulin; Male; Obesity; Rats; Rats, Sprague-Dawley; Sodium-Glucose Transporter 1; Sucrose | 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 |
Molecular Integration of Incretin and Glucocorticoid Action Reverses Immunometabolic Dysfunction and Obesity.
Chronic inflammation has been proposed to contribute to the pathogenesis of diet-induced obesity. However, scarce therapeutic options are available to treat obesity and the associated immunometabolic complications. Glucocorticoids are routinely employed for the management of inflammatory diseases, but their pleiotropic nature leads to detrimental metabolic side effects. We developed a glucagon-like peptide-1 (GLP-1)-dexamethasone co-agonist in which GLP-1 selectively delivers dexamethasone to GLP-1 receptor-expressing cells. GLP-1-dexamethasone lowers body weight up to 25% in obese mice by targeting the hypothalamic control of feeding and by increasing energy expenditure. This strategy reverses hypothalamic and systemic inflammation while improving glucose tolerance and insulin sensitivity. The selective preference for GLP-1 receptor bypasses deleterious effects of dexamethasone on glucose handling, bone integrity, and hypothalamus-pituitary-adrenal axis activity. Thus, GLP-1-directed glucocorticoid pharmacology represents a safe and efficacious therapy option for diet-induced immunometabolic derangements and the resulting obesity. Topics: Animals; Body Weight; Dexamethasone; Energy Metabolism; Glucagon-Like Peptide 1; Glucocorticoids; Glucose; HEK293 Cells; Humans; Hypothalamus; Incretins; Inflammation; Male; Mice; Mice, Inbred C57BL; Mice, Obese; Obesity | 2017 |
Single-cell RNA-sequencing reveals a distinct population of proglucagon-expressing cells specific to the mouse upper small intestine.
To identify sub-populations of intestinal preproglucagon-expressing (PPG) cells producing Glucagon-like Peptide-1, and their associated expression profiles of sensory receptors, thereby enabling the discovery of therapeutic strategies that target these cell populations for the treatment of diabetes and obesity.. We performed single cell RNA sequencing of PPG-cells purified by flow cytometry from the upper small intestine of 3 GLU-Venus mice. Cells from 2 mice were sequenced at low depth, and from the third mouse at high depth. High quality sequencing data from 234 PPG-cells were used to identify clusters by tSNE analysis. qPCR was performed to compare the longitudinal and crypt/villus locations of cluster-specific genes. Immunofluorescence and mass spectrometry were used to confirm protein expression.. PPG-cells formed 3 major clusters: a group with typical characteristics of classical L-cells, including high expression of Gcg and Pyy (comprising 51% of all PPG-cells); a cell type overlapping with Gip-expressing K-cells (14%); and a unique cluster expressing Tph1 and Pzp that was predominantly located in proximal small intestine villi and co-produced 5-HT (35%). Expression of G-protein coupled receptors differed between clusters, suggesting the cell types are differentially regulated and would be differentially targetable.. Our findings support the emerging concept that many enteroendocrine cell populations are highly overlapping, with individual cells producing a range of peptides previously assigned to distinct cell types. Different receptor expression profiles across the clusters highlight potential drug targets to increase gut hormone secretion for the treatment of diabetes and obesity. Topics: Animals; Enteroendocrine Cells; Flow Cytometry; Gene Expression; Glucagon-Like Peptide 1; Intestinal Mucosa; Intestine, Small; Intestines; Mice; Obesity; Proglucagon; RNA; Sequence Analysis, RNA | 2017 |
Recombinant Incretin-Secreting Microbe Improves Metabolic Dysfunction in High-Fat Diet Fed Rodents.
The gut hormone glucagon-like peptide (GLP)-1 and its analogues represent a new generation of anti-diabetic drugs, which have also demonstrated propensity to modulate host lipid metabolism. Despite this, drugs of this nature are currently limited to intramuscular administration routes due to intestinal degradation. The aim of this study was to design a recombinant microbial delivery vector for a GLP-1 analogue and assess the efficacy of the therapeutic in improving host glucose, lipid and cholesterol metabolism in diet induced obese rodents. Diet-induced obese animals received either Lactobacillus paracasei NFBC 338 transformed to express a long-acting analogue of GLP-1 or the isogenic control microbe which solely harbored the pNZ44 plasmid. Short-term GLP-1 microbe intervention in rats reduced serum low-density lipoprotein cholesterol, triglycerides and triglyceride-rich lipoprotein cholesterol substantially. Conversely, extended GLP-1 microbe intervention improved glucose-dependent insulin secretion, glucose metabolism and cholesterol metabolism, compared to the high-fat control group. Interestingly, the microbe significantly attenuated the adiposity associated with the model and altered the serum lipidome, independently of GLP-1 secretion. These data indicate that recombinant incretin-secreting microbes may offer a novel and safe means of managing cholesterol metabolism and diet induced dyslipidaemia, as well as insulin sensitivity in metabolic dysfunction. Topics: Animals; Cholesterol, LDL; Diet, High-Fat; Disease Models, Animal; Glucagon-Like Peptide 1; Glucose; Glucose Tolerance Test; Insulin; Insulin-Secreting Cells; Lactobacillus; Metabolome; Mice; Mice, Inbred C57BL; Obesity; Plasmids; Rats; Rats, Long-Evans; Triglycerides | 2017 |
GLP-1 Elicits an Intrinsic Gut-Liver Metabolic Signal to Ameliorate Diet-Induced VLDL Overproduction and Insulin Resistance.
Perturbations in hepatic lipid and very-low-density lipoprotein (VLDL) metabolism are involved in the pathogenesis of obesity and hepatic insulin resistance. The objective of this study is to delineate the mechanism of subdiaphragmatic vagotomy in preventing obesity, hyperlipidemia, and insulin resistance.. By subjecting the complete subdiaphragmatic vagotomized mice to various nutritional conditions and investigating hepatic de novo lipogenesis pathway, we found that complete disruption of subdiaphragmatic vagal signaling resulted in a significant decrease of circulating VLDL-triglyceride compared with the mice obtained sham procedure. Vagotomy further prevented overproduction of VLDL-triglyceride induced by an acute fat load and a high-fat diet-induced obesity, hyperlipidemia, hepatic steatosis, and glucose intolerance. Mechanistic studies revealed that plasma glucagon-like peptide-1 was significantly raised in the vagotomized mice, which was associated with significant reductions in mRNA and protein expression of SREBP-1c (sterol regulatory element-binding protein 1c), SCD-1 (stearoyl-CoA desaturase-1), and FASN (fatty acid synthase), as well as enhanced hepatic insulin sensitivity. In vitro, treating mouse primary hepatocytes with a glucagon-like peptide-1 receptor agonist, exendin-4, for 48 hours inhibited free fatty acid, palmitic acid treatment induced de novo lipid synthesis, and VLDL secretion from hepatocytes.. Elevation of glucagon-like peptide-1 in vagotomized mice may prevent VLDL overproduction and insulin resistance induced by high-fat diet. These novel findings, for the first time, delineate an intrinsic gut-liver regulatory circuit that is mediated by glucagon-like peptide-1 in regulating hepatic energy metabolism. Topics: Animals; Biomarkers; Blood Glucose; Cells, Cultured; Diet, High-Fat; Disease Models, Animal; Exenatide; Fatty Acid Synthase, Type I; Fatty Liver; Gene Expression Regulation; Glucagon-Like Peptide 1; Hepatocytes; Hyperlipidemias; Incretins; Insulin; Insulin Resistance; Intestinal Mucosa; Intestines; Lipoproteins, VLDL; Liver; Male; Mice, Inbred C57BL; Obesity; Peptides; RNA, Messenger; Signal Transduction; Stearoyl-CoA Desaturase; Sterol Regulatory Element Binding Protein 1; Time Factors; Triglycerides; Up-Regulation; Vagotomy; Vagus Nerve; Venoms | 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 |
Alterations in circadian and meal-induced gut peptide levels in lean and obese rats.
Alterations in gut hormone signaling are a likely contributing factor to the metabolic disturbances associated with overweight/obesity as they coordinate the timing of feeding behavior, absorption, and utilization of nutrients. These hormones are released in response to food intake, or follow a circadian or anticipatory pattern of secretion that is independent of nutrient stimulation. The aim of this study was to identify the degree to which high-fat diet-induced obesity would alter the daily rhythm of gut peptide plasma levels (glucagon-like peptide-1 [GLP-1], peptide YY [PYY], insulin or amylin [AMY]) or meal-induced levels in the middle of the light or dark cycle. Male Sprague-Dawley rats were fed a high-fat diet (OBESE) or chow (LEAN), implanted with jugular catheters, and blood samples were taken every 2 h throughout the light/dark cycle while freely feeding or after an Ensure liquid meal. We found that even when OBESE and LEAN animals ate the same kcals and have a similar pattern of food intake, there is a difference in both the levels and rhythm of plasma gut peptides. GLP-1 and PYY are higher during the light cycle in LEAN animals and AMY is higher in the OBESE group throughout the light/dark cycle. There was also a differential response of plasma gut signals after the Ensure meal, even though the composition and amount of intake of the meal were the same in both groups. These changes occur prior to the high-fat diet induced loss of glycemic control and may be a target for early intervention. Impact statement The aim of this study was to test if obesity would alter the daily rhythm of gut peptides or meal-induced levels in the middle of the light or dark cycle. We found that even when animals are eating the same amount (in kcal) of food that the obese animals have altered daily rhythms and meal-induced gut peptide levels. In particular, we are the first to show that obesity induces increases in peptide YY levels during the light cycle and amylin remains high throughout the light and dark cycle in obese animals. These changes occurred prior to a loss of glycemic control. Thus, the rhythm of gut peptides could be used as an early indicator of later and more serious metabolic disturbances and may be a target for early intervention. Topics: Animals; Blood Glucose; Body Weight; Circadian Rhythm; Diet, High-Fat; Eating; Feeding Behavior; Gastrointestinal Hormones; Glucagon-Like Peptide 1; Male; Models, Animal; Obesity; Rats, Sprague-Dawley | 2017 |
Obese ZDF rats fermented resistant starch with effects on gut microbiota but no reduction in abdominal fat.
To determine if whole-grain (WG) flour with resistant starch (RS) will produce greater fermentation than isolated RS in obese Zucker Diabetic Fatty (ZDF) rats, and whether greater fermentation results in different microbiota, reduced abdominal fat, and increased insulin sensitivity.. This study utilized four groups fed diets made with either isolated digestible control starch, WG control flour (6.9% RS), isolated RS-rich corn starch (25% RS), or WG corn flour (25% RS). ZDF rats fermented RS and RS-rich WG flour to greatest extent among groups. High-RS groups had increased serum glucagon-like peptide 1 (GLP-1) active. Feeding isolated RS showed greater Bacteroidetes to Firmicutes phyla among groups, and rats consuming low RS diets possessed more bacteria in Lactobacillus genus. However, no differences in abdominal fat were observed, but rats with isolated RS had greatest insulin sensitivity among groups.. Data demonstrated ZDF rats (i) possess a microbiota that fermented RS, and (ii) WG high-RS fermented better than purified RS. However, fermentation and microbiota changes did not translate into reduced abdominal fat. The defective leptin receptor may limit ZDF rats from responding to increased GLP-1 and different microbiota for reducing abdominal fat, but did not prevent improved insulin sensitivity. Topics: Abdominal Fat; Animals; Body Weight; Cecum; Digestion; Fermentation; Gastrointestinal Microbiome; Glucagon-Like Peptide 1; Insulin; Male; Obesity; Rats, Zucker; Receptors, Leptin; Starch; Whole Grains | 2017 |
Pulse Width-Dependent Effects of Intestinal Electrical Stimulation for Obesity: Role of Gastrointestinal Motility and Hormones.
The goals of this experiment were to study therapeutic potential of intestinal electrical stimulation (IES) for obesity, its mechanisms involving gastrointestinal motility and hormones, and role of pulse width in diet-induced obese rats.. In a 4-week study, rats equipped with one pair of electrodes at the duodenum were assigned to receive either a sham or IES of varied pulse widths in a sequential way. Food intake was measured daily and body weight measured weekly. Blood samples were collected for the measurement of glucagon-like peptide-1 (GLP-1). Solid gastric emptying (GE) and small bowel transit (SIT) tests were performed at the end of the experiment.. The results of the study were as follows: (1) Daily food intake, not affected by IES of 0.3 ms, was pulse width-dependently reduced by 1.9 g with 1 ms and by 5.7 g with 3 ms. Accordingly, body weight was pulse width-dependently reduced by 2.4 g with 1 ms and by 12.8 g with 3 ms compared to a gain of 5.6 g in sham. (2) GLP-1 level was elevated by both 0.3 and 3 ms at 15 min, but was elevated only with 3 ms at 60 min. (3) GE was delayed to 52.3 % by IES of 3 ms but not 0.3 ms, compared to that at 64.4 % with sham IES. (4) Compared to the geometric center of 7.0 with sham IES, SIT was accelerated by 3 ms to 7.8 but not by 0.3 ms.. IES pulse width-dependently reduces food intake and body weight, attributed to the delay of gastric emptying and the acceleration of small bowel transit, as well as the enhancement of GLP-1 secretion. Topics: Animals; Body Weight; Disease Models, Animal; Duodenum; Eating; Electric Stimulation; Electric Stimulation Therapy; Gastric Emptying; Gastrointestinal Hormones; Gastrointestinal Motility; Gastrointestinal Transit; Glucagon-Like Peptide 1; Male; Obesity; Rats; Rats, Sprague-Dawley | 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 |
The endocrine disrupting potential of monosodium glutamate (MSG) on secretion of the glucagon-like peptide-1 (GLP-1) gut hormone and GLP-1 receptor interaction.
Monosodium glutamate (MSG) is a suspected obesogen with epidemiological evidence positively correlating consumption to increased body mass index and higher prevalence of metabolic syndrome. ELISA and high content analysis (HCA) were employed to examine the disruptive effects of MSG on the secretion of enteroendocrine hormone glucagon-like peptide-1 (GLP-1) and GLP-1 receptor (GLP-1R), respectively. Following 3h MSG exposure of the enteroendocrine pGIP/neo: STC-1 cell line model (500μg/ml) significantly increased GLP-1 secretion (1.8 fold; P≤0.001), however, 72h exposure (500μg/ml) caused a 1.8 fold decline (P≤0.05). Also, 3h MSG exposure (0.5-500μg/ml) did not induce any cytotoxicity (including multiple pre-lethal markers) but 72h exposure at 250-500μg/ml, decreased cell number (11.8-26.7%; P≤0.05), increased nuclear area (23.9-29.8%; P≤0.001) and decreased mitochondrial membrane potential (13-21.6%; P≤0.05). At 500μg/ml, MSG increased mitochondrial mass by 16.3% (P≤0.01). MSG did not agonise or antagonise internalisation of the GLP-1R expressed recombinantly in U2OS cells, following GLP-1 stimulation. In conclusion, 72h exposure of an enteroendocrine cell line at dietary levels of MSG, results in pre-lethal cytotoxicity and decline in GLP-1 secretion. These adverse events may play a role in the pathogenesis of obesity as outlined in the obesogen hypothesis by impairing GLP-1 secretion, related satiety responses and glucose-stimulated insulin release. Topics: Animals; Cell Culture Techniques; Cell Line; Cell Survival; Endocrine Disruptors; Enteroendocrine Cells; Glucagon-Like Peptide 1; Glucagon-Like Peptide-1 Receptor; Humans; Intestinal Mucosa; Mice; Obesity; Sodium Glutamate; Time Factors | 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 |
Association of betatrophin with metabolic characteristics in overweight/obese and lean women with PCOS.
As a new hormone, betatrophin has gained attention as a potential new target to combat insulin resistance (IR) and diabetes. Polycystic ovary syndrome (PCOS) is a common endocrine and metabolic disorder among women of the reproductive age with long term sequelae which include IR and metabolic syndrome. The aim of this study is to evaluate the circulating plasma betatrophin levels in overweight/obese or lean women with or without PCOS and also to elucidate possible correlations with anthropometric and metabolic parameters. Thirty-two patients with PCOS as well as fifty-three control subjects were enrolled after obtaining informed written consent. Clinical and biochemical parameters of all subjects were determined. Plasma adiponectin, GLP-1 and betatrophin levels were measured by ELISA. Plasma betatrophin levels were significantly increased in lean patients with PCOS compared with lean and obese controls. Moreover, in PCOS group, betatrophin levels were significantly negatively correlated with waist hip ratio (WHR), fasting insulin level (FINS) and HOMA-IR, whereas, significantly positively correlated with adiponectin level. Multiple regression analysis showed that HOMA-IR was an independent factor influencing serum betatrophin levels. Further follow-up studies are needed to highlight whether and how increased betatrophin secretion play an important role in IR and carbohydrates metabolism in patients with PCOS. Topics: Adiponectin; Adolescent; Adult; Angiopoietin-Like Protein 8; Angiopoietin-like Proteins; Biomarkers; Body Mass Index; China; Cross-Sectional Studies; Female; Glucagon-Like Peptide 1; Humans; Insulin Resistance; Middle Aged; Obesity; Overweight; Peptide Hormones; Polycystic Ovary Syndrome; Premenopause; Thinness; Waist-Hip Ratio; Young Adult | 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 |
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 |
Postprandial GLP-2 Levels Are Increased After Biliopancreatic Diversion in Diabetic Individuals with Class I Obesity: a Prospective Study.
Biliopancreatic diversion (BPD) is a predominantly malabsorptive procedure. Glucagon-like peptide 2 (GLP-2) plays predominantly trophic effects on the gut. A significant increase in GLP-2 after BPD in rats was previously observed, but there are no studies investigating the effect of BPD in GLP-2 levels in humans.. The aim of this study is to evaluate the influence of BPD on the release of GLP-2.. This is a prospective cohort study that evaluated diabetic individuals with class I obesity which underwent BPD (Scopinaro operation) and were followed up for 12 months. Of 12 individuals, four did not comply with the proposed follow-up and were excluded from the analysis. GLP-2 levels were determined by means of an enzyme-linked immunosorbent assay (ELISA), and we collected serial lab samples through a standard meal tolerance test (MTT) in the immediate preoperative period and 12 months after surgery.. During standard MTT, we observed significant increases of GLP-2 levels from 15 to 60 min (respectively, at 15 min, 5.7 ± 3.4 versus 12.4 ± 4.3, p = 0.029; 30 min, 6 ± 3.5 versus 14.6 ± 3.9; p = 0.004; 45 min, 5.6 ± 4.1 versus 12.6 ± 5.2, p = 0.013; 60 min, 5.8 ± 2.9 versus 10.6 ± 5.6, p = 0.022); then it began to gradually decrease to levels close to the basal.. Our findings have confirmed that there is a significant increase in GLP-2 levels after BPD in humans. GLP-2 plays a number of roles which may be adaptive, compensatory, and beneficial in the context of BPD. The clinical implications of this finding remain to be completely understood. Topics: Adult; Animals; Biliopancreatic Diversion; Diabetes Complications; Diabetes Mellitus; Female; Glucagon-Like Peptide 1; Glucagon-Like Peptide 2; Humans; Male; Middle Aged; Obesity; Postprandial Period; Prospective Studies; Rats | 2017 |
When gut fermentation controls satiety: A PYY story.
Topics: Fermentation; Glucagon-Like Peptide 1; Obesity; Peptide YY; Satiation; Satiety Response | 2017 |
Fermentable carbohydrate stimulates FFAR2-dependent colonic PYY cell expansion to increase satiety.
Dietary supplementation with fermentable carbohydrate protects against body weight gain. Fermentation by the resident gut microbiota produces short-chain fatty acids, which act at free fatty acid receptor 2 (FFAR2). Our aim was to test the hypothesis that FFAR2 is important in regulating the beneficial effects of fermentable carbohydrate on body weight and to understand the role of gut hormones PYY and GLP-1.. Wild-type or. We provide new mechanistic insight into how fermentable carbohydrate regulates metabolism. Using mice that lack FFAR2, we demonstrate that the fermentable carbohydrate inulin acts via this receptor to drive an 87% increase in the density of cells that produce the appetite-suppressing hormone peptide YY (PYY), reduce food intake, and prevent diet-induced obesity.. Our results demonstrate that FFAR2 is predominantly involved in regulating the effects of fermentable carbohydrate on metabolism and does so, in part, by enhancing PYY cell density and release. This highlights the potential for targeting enteroendocrine cell differentiation to treat obesity. Topics: Animals; Body Weight; Colon; Dietary Carbohydrates; Dietary Supplements; Eating; Fatty Acids, Volatile; Fermentation; Fermented Foods; Gastrointestinal Hormones; Gastrointestinal Microbiome; Glucagon-Like Peptide 1; Inulin; Male; Mice; Mice, Knockout; Obesity; Peptide YY; Receptors, Cell Surface; Weight Gain | 2017 |
Obesity: 5-HT
Topics: Glucagon-Like Peptide 1; Humans; Obesity; Weight Loss | 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 |
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 |
The Importance of the Gastrointestinal Tract in Controlling Food Intake and Regulating Energy Balance.
The gastrointestinal tract, the key interface between ingested nutrients and the body, plays a critical role in regulating energy homeostasis. Gut-derived signals convey information regarding incoming nutrients to the brain, initiating changes in eating behavior and energy expenditure, to maintain energy balance. Here we review hormonal, neural, and nutrient signals emanating from the gastrointestinal tract and evidence for their role in controlling feeding behavior. Mechanistic studies that have utilized pharmacologic and/or transgenic approaches targeting an individual hormone/mediator have yielded somewhat disappointing body weight changes, often leading to the hormone/mediator in question being dismissed as a potential obesity therapy. However, the recent finding of sustained weight reduction in response to systemic administration of a long-acting analog of the gut-hormone glucagon-like peptide-1 highlights the therapeutic potential of gut-derived signals acting via nonphysiologic mechanisms. Thus, we also review therapeutics strategies being utilized or developed to leverage gastrointestinal signals in order to treat obesity. Topics: Animals; Apolipoproteins A; Calcium-Binding Proteins; Cholecystokinin; DNA-Binding Proteins; Eating; Energy Metabolism; Enteroendocrine Cells; Gastrointestinal Hormones; Gastrointestinal Tract; Ghrelin; Glucagon-Like Peptide 1; Homeostasis; Humans; Leptin; Natriuretic Peptides; Nerve Tissue Proteins; Neurons, Afferent; Neurotensin; Nucleobindins; Obesity; Oxyntomodulin; Peptide YY; Receptors, G-Protein-Coupled | 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 |
Structural imaging of the brain reveals decreased total brain and total gray matter volumes in obese but not in lean women with polycystic ovary syndrome compared to body mass index-matched counterparts.
To detect differences in global brain volumes and identify relations between brain volume and appetite-related hormones in women with polycystic ovary syndrome (PCOS) compared to body mass index-matched controls.. Forty subjects participated in this study. Cranial magnetic resonance imaging and measurements of fasting ghrelin, leptin and glucagon-like peptide 1 (GLP-1), as well as GLP-1 levels during mixed-meal tolerance test (MTT), were performed.. Total brain volume and total gray matter volume (GMV) were decreased in obese PCOS compared to obese controls (p < 0.05 for both) whereas lean PCOS and controls did not show a significant difference. Secondary analyses of regional brain volumes showed decreases in GMV of the caudate nucleus, ventral diencephalon and hippocampus in obese PCOS compared to obese controls (p < 0.05 for all), whereas lean patients with PCOS had lower GMV in the amygdala than lean controls (p < 0.05). No significant relations were detected between structural differences and measured hormone levels at baseline or during MTT.. This study, investigating structural brain alterations in PCOS, suggests volumetric reductions in global brain areas in obese women with PCOS. Functional studies with larger sample size are needed to determine physiopathological roles of these changes and potential effects of long-term medical management on brain structure of PCOS. Topics: Adolescent; Adult; Blood Glucose; Body Mass Index; Brain; Female; Ghrelin; Glucagon-Like Peptide 1; Gray Matter; Humans; Leptin; Magnetic Resonance Imaging; Obesity; Organ Size; Polycystic Ovary Syndrome; Young Adult | 2017 |
Altered circulating concentrations of active glucagon-like peptide (GLP-1) and dipeptidyl peptidase 4 (DPP4) in obese subjects and their association with insulin resistance.
Soluble DPP4 (sDPP4) is a novel adipokine that degrades glucagon-like peptide (GLP-1). We evaluated the fasting serum levels of active GLP-1 and sDPP4 in obese, overweight and normal weight subjects to assess the association between sDPP4 levels, active GLP-1 levels and insulin resistance in obese subjects.. The study involved 235 Malaysian subjects who were randomly selected (66 normal weight subjects, 97 overweight, 59 obese subjects, and 13 subjects who were underweight). Serum sDPP4 and active GLP-1 levels were examined by enzyme-linked immunosorbent assay (ELISA). Also, body mass index kg/m. Serum sDPP4 levels were significantly higher in obese subjects compared to normal weight subjects (p=0.034), whereas serum levels of active GLP-1 were lower (p=0.021). In obese subjects, sDPP4 levels correlated negatively with active GLP-1 levels (r. Elevated serum sDPP4 levels and reduced GLP-1 levels were observed in obese subjects. In addition, sDPP4 levels correlated negatively with active GLP-1 levels but was positively associated with insulin resistance. This finding provides evidence that sDPP4 and GLP-1 may play an important role in the pathogenesis of obesity, suggesting that sDPP4 may be valuable as an early marker for the augmented risk of obesity and insulin resistance. Topics: Adult; Aged; Biomarkers; Body Mass Index; Dipeptidyl Peptidase 4; Down-Regulation; Female; Glucagon-Like Peptide 1; Humans; Insulin Resistance; Linear Models; Malaysia; Male; Middle Aged; Obesity; Overweight; Risk; Solubility; Thinness; Up-Regulation | 2017 |
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 |
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 |
Differences in Alimentary Glucose Absorption and Intestinal Disposal of Blood Glucose After Roux-en-Y Gastric Bypass vs Sleeve Gastrectomy.
Bariatric procedures, such as Roux-en-Y gastric bypass (RYGB) or vertical sleeve gastrectomy (VSG), are the most effective approaches to resolve type 2 diabetes in obese individuals. Alimentary glucose absorption and intestinal disposal of blood glucose have not been directly compared between individuals or animals that underwent RYGB vs VSG. We evaluated in rats and humans how the gut epithelium adapts after surgery and the consequences on alimentary glucose absorption and intestinal disposal of blood glucose.. Obese male rats underwent RYGB, VSG, or sham (control) operations. We collected intestine segments from all rats; we performed histologic analyses and measured levels of messenger RNAs encoding the sugar transporters SGLT1, GLUT1, GLUT2, GLUT3, GLUT4, and GLUT5. Glucose transport and consumption were assayed using ex vivo jejunal loops. Histologic analyses were also performed on Roux limb sections from patients who underwent RYGB 1-5 years after surgery. Roux limb glucose consumption was assayed after surgery by positron emission and computed tomography imaging.. In rats and humans that underwent RYGB, the Roux limb became hyperplasic, with an increased number of incretin-producing cells compared with the corresponding jejunal segment of controls. Furthermore, expression of sugar transporters and hypoxia-related genes increased and the nonintestinal glucose transporter GLUT1 appeared at the basolateral membrane of enterocytes. Ingested and circulating glucose was trapped within the intestinal epithelial cells of rats and humans that underwent RYGB. By contrast, there was no hyperplasia of the intestine after VSG, but the intestinal absorption of alimentary glucose was reduced and density of endocrine cells secreting glucagon-like peptide-1 increased.. The intestine adapts differently to RYGB vs VSG. RYGB increases intestinal glucose disposal and VSG delays glucose absorption; both contribute to observed improvements in glycemia. Topics: Adaptation, Physiological; Adult; Animals; Blood Glucose; Disease Models, Animal; Gastrectomy; Gastric Bypass; Glucagon-Like Peptide 1; Glucose Transport Proteins, Facilitative; Humans; Hyperplasia; Intestinal Absorption; Intestinal Mucosa; Jejunum; Male; Middle Aged; Obesity; Positron-Emission Tomography; Rats; Retrospective Studies; RNA, Messenger; Time Factors; Tomography, X-Ray Computed | 2016 |
Intermittent access to a sucrose solution impairs metabolism in obesity-prone but not obesity-resistant mice.
Consumption of sugar-sweetened beverages is associated with overweight and obesity. In this study, we hypothesized that obesity-prone (OP) mice fed a high-fat high-sucrose diet (HFHS) are more sensitive to consumption of sucrose-sweetened water (SSW) than obesity-resistant (OR) mice. After 3weeks of ad libitum access to the HFHS diet (7.5h/day), 180 male mice were classified as either OP (upper quartile of body weight gain, 5.2±0.1g, n=45) or OR (lower quartile, 3.2±0.1g, n=45). OP and OR mice were subsequently divided into 3 subgroups that had access to HFHS (7.5h/day) for 16weeks, supplemented with: i) water (OP/water and OR/water); ii) water and SSW (12.6% w/v), available for 2h/day randomly when access to HFHS was available and for 5 randomly-chosen days/week (OP/SSW and OR/SSW); or iii) water and SSW for 8weeks, then only water for 8weeks (OP/SSW-water and OR/SSW-water). OR/SSW mice decreased their food intake compared to OR/water mice, while OP/SSW mice exhibited an increase in food and total energy intake compared to OP/water mice. OP/SSW mice also gained more body weight and fat mass than OP/water mice, showed an increase in liver triglycerides and developed insulin resistance. These effects were fully reversed in OP/SSW-water mice. In the gut, OR/SSW mice, but not OP/SSW mice, had an increase GLP-1 and CCK response to a liquid meal compared to mice drinking only water. OP/SSW mice had a decreased expression of melanocortin receptor 4 in the hypothalamus and increased expression of delta opioid receptor in the nucleus accumbens compared to OP/water mice when fasted that could explain the hyperphagia in these mice. When access to the sucrose solution was removed for 8weeks, OP mice had increased dopaminergic and opioidergic response to a sucrose solution. Thus, intermittent access to a sucrose solution in mice fed a HFHS diet induces changes in the gut and brain signaling, leading to increased energy intake and adverse metabolic consequences only in mice prone to HFHS-induced obesity. Topics: Animals; Body Composition; Body Weight; Cholecystokinin; Diet, High-Fat; Disease Models, Animal; Drinking; Eating; Energy Metabolism; Gene Expression Regulation; Glucagon-Like Peptide 1; Glucose Tolerance Test; Hyperphagia; Lipid Peroxidation; Male; Mice; Mice, Inbred C57BL; Mice, Obese; Obesity; Sucrose; Sweetening Agents | 2016 |
Circulating concentrations of glucagon-like peptide 1, glucose-dependent insulinotropic peptide, peptide YY, and insulin in client-owned lean, overweight, and diabetic cats.
Our objectives were to measure plasma concentrations of glucagon-like peptide 1 (GLP-1), glucose-dependent insulinotropic peptide (GIP), and peptide YY (PYY) in client-owned newly diagnosed diabetic cats and nondiabetic lean or overweight cats and to determine whether circulating concentrations of these hormones differed between study groups and if they increased postprandially as seen in other species. A total of 31 cats were recruited and placed into 1 of 3 study groups: lean (body condition score 4-5 on a scale of 1-9; n = 10), overweight (body condition score 6-8; n = 11), or diabetic (n = 10). Diabetics were newly diagnosed and had not had prior insulin therapy. Preprandial (fasting) and postprandial (60 min after meal) plasma hormone and glucose concentrations were measured at baseline and 2 and 4 wk. All cats were exclusively fed a commercially available high-protein and low-carbohydrate diet commonly prescribed to feline diabetic patients for 2 wk before the 2-wk assessment and continued through the 4-wk assessment. Results showed that plasma concentrations of GLP-1, GIP, PYY, and insulin increased in general after a meal in all study groups. Plasma PYY concentrations did not differ (P > 0.10) between study groups. Diabetics had greater plasma concentrations of GLP-1 and GIP compared with the other study groups at baseline (P < 0.05), and greater preprandial and postprandial GLP-1 concentrations than lean cats at 2 and 4 wk (P < 0.05). Preprandial plasma GIP concentrations were greater in diabetics than obese and lean (P < 0.05) cats at week 4. Postprandial plasma GIP concentrations in diabetics were greater than lean (P < 0.05) at week 2 and obese and lean cats (P < 0.05) at week 4. Together, our findings suggest that diabetic status is an important determinant of circulating concentrations of GLP-1 and GIP, but not PYY, in cats. The role of GLP-1, GIP, and PYY in the pathophysiology of feline obesity and diabetes remains to be determined. Topics: Animals; Cat Diseases; Cats; Diabetes Mellitus; Fasting; Gastric Inhibitory Polypeptide; Glucagon-Like Peptide 1; Insulin; Obesity; Overweight; Peptide YY; Postprandial Period | 2016 |
Gastrin Secretion After Bariatric Surgery-Response to a Protein-Rich Mixed Meal Following Roux-En-Y Gastric Bypass and Sleeve Gastrectomy: a Pilot Study in Normoglycemic Women.
Recent investigations have linked elevated gastrin levels to the improvement of type 2 diabetes mellitus (T2DM). Roux-en-Y gastric bypass (RYGB) and sleeve gastrectomy (SG) are effective treatments for T2DM, but it is not known if this is related to postoperative alterations of gastrin secretion.. Twenty women previously operated with RYGB or SG and 13 female controls were enrolled and evaluated for body mass index, lipids, C-peptide, HbA1c, and anti-H. pylori IgG. Glucose, gastrin, insulin, and glucagon-like peptide 1 (GLP-1) concentrations were measured before and 30, 60, 90, and 120 min after ingestion of a protein-rich mixed meal.. Six participants primarily selected were excluded due to usage of proton pump inhibitors, positive H.pylori IgG, or history of T2DM, yielding the following groups: RYGB (n = 9), SG (n = 8), and controls (n = 10). There were no differences in age, body mass index, HbA1c, or C-peptide levels between groups. RYGB had significantly lower area under the curve (AUC) for glucose during the test compared to controls (p = 0.013). RYGB showed lower serum gastrin levels compared to SG and controls (p < 0.05 for all). There was a non-significant increased gastrin release in SG compared to controls (p = 0.091). For SG and controls, there was a negative correlation between glucose and gastrin response (p = 0.0043).. Gastrin secretion is diminished after RYGB. Hypergastrinemia was not present after SG, but a tendency of enhanced gastrin secretion was observed. These findings require further investigation in prospective studies. Topics: Adult; Aged; Blood Glucose; Dietary Proteins; Female; Gastrectomy; Gastric Bypass; Gastrins; Glucagon-Like Peptide 1; Humans; Insulin; Middle Aged; Obesity; Pilot Projects; Prospective Studies | 2016 |
Liraglutide and Cardiometabolic Effects: More than Just Another Antiobesity Drug?
Topics: Female; Glucagon-Like Peptide 1; Humans; Hypoglycemic Agents; Male; Obesity | 2016 |
GLP-1 is both anxiogenic and antidepressant; divergent effects of acute and chronic GLP-1 on emotionality.
Glucagon-like peptide 1 (GLP-1), produced in the intestine and hindbrain, is known for its glucoregulatory and appetite suppressing effects. GLP-1 agonists are in clinical use for treatment of type 2 diabetes and obesity. GLP-1, however, may also affect brain areas associated with emotionality regulation. Here we aimed to characterize acute and chronic impact of GLP-1 on anxiety and depression-like behavior. Rats were subjected to anxiety and depression behavior tests following acute or chronic intracerebroventricular or intra-dorsal raphe (DR) application of GLP-1 receptor agonists. Serotonin or serotonin-related genes were also measured in the amygdala, DR and the hippocampus. We demonstrate that both GLP-1 and its long lasting analog, Exendin-4, induce anxiety-like behavior in three rodent tests of this behavior: black and white box, elevated plus maze and open field test when acutely administered intraperitoneally, into the lateral ventricle, or directly into the DR. Acute central GLP-1 receptor stimulation also altered serotonin signaling in the amygdala. In contrast, chronic central administration of Exendin-4 did not alter anxiety-like behavior but significantly reduced depression-like behavior in the forced swim test. Importantly, this positive effect of Exendin-4 was not due to significant body weight loss and reduced food intake, since rats pair-fed to Exendin-4 rats did not show altered mood. Collectively we show a striking impact of central GLP-1 on emotionality and the amygdala serotonin signaling that is divergent under acute versus chronic GLP-1 activation conditions. We also find a novel role for the DR GLP-1 receptors in regulation of behavior. These results may have direct relevance to the clinic, and indicate that Exendin-4 may be especially useful for obese patients manifesting with comorbid depression. Topics: Animals; Anti-Anxiety Agents; Antidepressive Agents; Anxiety; Body Weight; Brain; Emotions; Exenatide; Feeding Behavior; Glucagon-Like Peptide 1; Glucagon-Like Peptide-1 Receptor; Male; Obesity; Peptides; Rats; Rats, Sprague-Dawley; Serotonin; Venoms | 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 |
Dipeptidyl peptidase-4 inhibitor MK-626 restores insulin secretion through enhancing autophagy in high fat diet-induced mice.
Autophagy is cellular machinery for maintenance of β-cell function and mass. The current study aimed to investigate the regulatory effects of MK-626, a dipeptidyl peptidase-4 inhibitor, on insulin secretion through the activation of autophagy in high fat diet-induced obese mice. C57BL/6 mice were fed with a rodent diet containing 45 kcal% fat for 16 weeks to induce obesity and then were received either vehicle or MK-626 (3 mg/kg/day) orally during the final 4 weeks. Mouse islets were isolated. Phosphorylation of serine/threonine-protein kinase mTOR and levels of light chain 3B I (LC3B I), LC3B II, sequestosome-1 (SQSTM1/p62) and autophagy-related protein-7 (Atg7) were examined by Western blotting. Glucagon like-peptide-1 (GLP-1) level and insulin secretion were measured by ELISA. GLP-1 level in plasma was decreased in obese mice, which was elevated by dipeptidyl peptidase-4 inhibitor MK-626. In the islets of obese mice, phosphorylation of mTOR, ratio of LC3B I and LC3B II, and level of p62 were elevated and the expression of Atg7 and insulin secretion were reduced compared to those of C57BL/6 mice. However, such effects were reversed by MK-626. Autophagy activator rapamycin stimulated insulin secretion in obese mice but autophagy inhibitor chloroquine treatment inhibited insulin secretion in obese mice administrated by MK-626. Furthermore, the beneficial effects of MK-626 were inhibited by GLP-1 receptor antagonist exendin 9-39. The present study reveals the activation of autophagy to mediate the anti-diabetic effect of GLP-1. Topics: Animals; Autophagy; Dietary Fats; Dipeptidyl-Peptidase IV Inhibitors; Dose-Response Relationship, Drug; Glucagon-Like Peptide 1; Insulin; Insulin Secretion; Islets of Langerhans; Male; Mice; Mice, Inbred C57BL; Obesity | 2016 |
Intestinal Phospholipid Remodeling Is Required for Dietary-Lipid Uptake and Survival on a High-Fat Diet.
Phospholipids are important determinants of membrane biophysical properties, but the impact of membrane acyl chain composition on dietary-lipid absorption is unknown. Here we demonstrate that the LXR-responsive phospholipid-remodeling enzyme Lpcat3 modulates intestinal fatty acid and cholesterol absorption and is required for survival on a high-fat diet. Mice lacking Lpcat3 in the intestine thrive on carbohydrate-based chow but lose body weight rapidly and become moribund on a triglyceride-rich diet. Lpcat3-dependent incorporation of polyunsaturated fatty acids into phospholipids is required for the efficient transport of dietary lipids into enterocytes. Furthermore, loss of Lpcat3 amplifies the production of gut hormones, including GLP-1 and oleoylethanolamide, in response to high-fat feeding, contributing to the paradoxical cessation of food intake in the setting of starvation. These results reveal that membrane phospholipid composition is a gating factor in passive lipid absorption and implicate LXR-Lpcat3 signaling in a gut-brain feedback loop that couples absorption to food intake. Topics: 1-Acylglycerophosphocholine O-Acyltransferase; Animals; Apolipoproteins; Cholesterol; Diet, High-Fat; Dietary Fats; Female; Glucagon-Like Peptide 1; Intestinal Absorption; Intestinal Mucosa; Intestines; Lipid Metabolism; Male; Membrane Fluidity; Mice, Inbred C57BL; Mice, Knockout; Obesity; Phospholipids; Transcriptional Activation; Triglycerides | 2016 |
L-arginine promotes gut hormone release and reduces food intake in rodents.
To investigate the anorectic effect of L-arginine (L-Arg) in rodents.. We investigated the effects of L-Arg on food intake, and the role of the anorectic gut hormones glucagon-like peptide-1 (GLP-1) and peptide YY (PYY), the G-protein-coupled receptor family C group 6 member A (GPRC6A) and the vagus nerve in mediating these effects in rodents.. Oral gavage of L-Arg reduced food intake in rodents, and chronically reduced cumulative food intake in diet-induced obese mice. Lack of the GPRC6A in mice and subdiaphragmatic vagal deafferentation in rats did not influence these anorectic effects. L-Arg stimulated GLP-1 and PYY release in vitro and in vivo. Pharmacological blockade of GLP-1 and PYY receptors did not influence the anorectic effect of L-Arg. L-Arg-mediated PYY release modulated net ion transport across the gut mucosa. Intracerebroventricular (i.c.v.) and intraperitoneal (i.p.) administration of L-Arg suppressed food intake in rats.. L-Arg reduced food intake and stimulated gut hormone release in rodents. The anorectic effect of L-Arg is unlikely to be mediated by GLP-1 and PYY, does not require GPRC6A signalling and is not mediated via the vagus. I.c.v. and i.p. administration of L-Arg suppressed food intake in rats, suggesting that L-Arg may act on the brain to influence food intake. Further work is required to determine the mechanisms by which L-Arg suppresses food intake and its utility in the treatment of obesity. Topics: Animals; Appetite Depressants; Arginine; Cells, Cultured; Dietary Supplements; Energy Intake; Energy Metabolism; Gastrointestinal Agents; Glucagon-Like Peptide 1; In Vitro Techniques; Injections, Intraperitoneal; Injections, Intraventricular; Intestinal Mucosa; Male; Mice, Inbred C57BL; Mice, Knockout; Obesity; Peptide YY; Random Allocation; Rats, Wistar; Receptors, G-Protein-Coupled; Weight Loss | 2016 |
Expression of the Bitter Taste Receptor, T2R38, in Enteroendocrine Cells of the Colonic Mucosa of Overweight/Obese vs. Lean Subjects.
Bitter taste receptors (T2Rs) are expressed in the mammalian gastrointestinal mucosa. In the mouse colon, T2R138 is localized to enteroendocrine cells and is upregulated by long-term high fat diet that induces obesity. The aims of this study were to test whether T2R38 expression is altered in overweight/obese (OW/OB) compared to normal weight (NW) subjects and characterize the cell types expressing T2R38, the human counterpart of mouse T2R138, in human colon. Colonic mucosal biopsies were obtained during colonoscopy from 35 healthy subjects (20 OW/OB and 15 NW) and processed for quantitative RT-PCR and immunohistochemistry using antibodies to T2R38, chromogranin A (CgA), glucagon like peptide-1 (GLP-1), cholecystokinin (CCK), or peptide YY (PYY). T2R38 mRNA levels in the colonic mucosa of OW/OB were increased (> 2 fold) compared to NW subjects but did not reach statistical significance (P = 0.06). However, the number of T2R38 immunoreactive (IR) cells was significantly increased in OW/OB vs. NW subjects (P = 0.01) and was significantly correlated with BMI values (r = 0.7557; P = 0.001). In both OW/OB and NW individuals, all T2R38-IR cells contained CgA-IR supporting they are enteroendocrine. In both groups, T2R38-IR colocalized with CCK-, GLP1- or PYY-IR. The overall CgA-IR cell population was comparable in OW/OB and NW individuals. This study shows that T2R38 is expressed in distinct populations of enteroendocrine cells in the human colonic mucosa and supports T2R38 upregulation in OW/OB subjects. T2R38 might mediate host functional responses to increased energy balance and intraluminal changes occurring in obesity, which could involve peptide release from enteroendocrine cells. Topics: Adult; Cholecystokinin; Chromogranin A; Colon; Enteroendocrine Cells; Female; Glucagon-Like Peptide 1; Humans; Intestinal Mucosa; Male; Middle Aged; Obesity; Overweight; Peptide YY; Receptors, G-Protein-Coupled; RNA, Messenger; Young Adult | 2016 |
Postprandial GLP-1 Secretion After Bariatric Surgery in Three Cases of Severe Obesity Related to Craniopharyngiomas.
Craniopharyngiomas are rare cerebral tumors associated with severe obesity after hypothalamic surgery. A meta-analysis showed significant weight loss at 1 year after bariatric surgery in these patients even though more modest than in common causes of obesity. We hypothesized that this discrepancy could be partly explained by differences in GLP-1 secretion after surgery since patients with craniopharyngioma present a significantly higher degree of insulin resistance and hyperinsulinism than common obese control. We report three cases of bariatric surgery in patients presenting with hypothalamique obesity related to craniopharyngiomas. At 18 months, the mean weight loss was 20 kg with expected insulin resistance decrease. Before surgery, standardized test meal shows abolition of postprandial GLP-1 secretion in all patients with a progressive restoration in the patients with gastric bypass (GBP) surgery. Topics: Bariatric Surgery; Craniopharyngioma; Female; Glucagon-Like Peptide 1; Humans; Male; Middle Aged; Obesity; Pituitary Neoplasms; Postprandial Period; Young Adult | 2016 |
liraglutide (SAXENDA⁰) and obesit. Still no satisfactory weight loss drugs.
No existing weight loss drug has an acceptable harm-benefit balance. Liraglutide, a GLP-1 agonist administered by subcutaneous injection and already authorised in type 2 diabetes, is also approved for use in the European Union by obese patients or overweight individuals with other cardiovascular risk factors. The recommended dose in this setting is 3 mg per day, instead of the dose of 1.2 to 1.8 mg per day used in diabetes. In four randomised, double-blind, placebo-controlled trials, each lasting one year, mean weight loss with liraglutide, beyond the placebo effect, was about 5% among patients initially weighing between 100 and 118 kg. These trials were not designed to show an effect of liraglutide on complications of excess weight. Gallstones, one of the complications of obesity, were more frequent in the liraglutide groups. Partial weight regain was reported during the 3 months following liraglutide withdrawal. effects, including pancreatic disorders. Patients should not be exposed to these unjustified risks. The known adverse effect profile of liraglutide, which includes severe pancreatitis and gallstones, was confirmed in the trials in obese patients. Gastrointestinal disorders (nausea, vomiting and diarrhoea) were very frequent. Hypoglycaemic episodes, sometimes severe, have mainly been reported in diabetic patients. Reactions at the injection site can also be serious. In trials in obese patients, liraglutide was associated with an increased risk of miscarriage. In practice, sometimes excessive weight loss is a known adverse effect of GLP-1 agonists used in diabetes. Many patients lose several kilograms with high-dose liraglutide but regain the weight after treatment discontinuation. Liraglutide has no proven impact on complications of obesity and carries a risk of serious adverse. Topics: Anti-Obesity Agents; Glucagon-Like Peptide 1; Humans; Injections, Subcutaneous; Liraglutide; Obesity; Randomized Controlled Trials as Topic; Weight Loss | 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 |
Peripheral, but not central, GLP-1 receptor signaling is required for improvement in glucose tolerance after Roux-en-Y gastric bypass in mice.
Roux-en-Y gastric bypass (RYGB) causes profound weight loss and remission of diabetes by influencing metabolic physiology, yet the mechanisms behind these clinical improvements remain undefined. After RYGB, levels of glucagon-like peptide-1 (GLP-1), a hormone that enhances insulin secretion and promotes satiation, are substantially elevated. Because GLP-1 signals in both the periphery and the brain to influence energy balance and glucose regulation, we aimed to determine the relative requirements of these systems to weight loss and improved glucose tolerance following RYGB surgery in mice. By pharmacologically blocking peripheral or central GLP-1R signaling, we examined whether GLP-1 action is necessary for the metabolic improvements observed after RYGB. Diet-induced obese mice underwent RYGB or sham operation and were implanted with osmotic pumps delivering the GLP-1R antagonist exendin-(9-39) (2 pmol·kg(-1)·min(-1) peripherally; 0.5 pmol·kg(-1)·min(-1) centrally) for up to 10 wk. Blockade of peripheral GLP-1R signaling partially reversed the improvement in glucose tolerance after RYGB. In contrast, fasting glucose and insulin sensitivity, as well as body weight, were unaffected by GLP-1R antagonism. Central GLP-1R signaling did not appear to be required for any of the metabolic improvements seen after this operation. Collectively, these results suggest a detectable but only modest role for GLP-1 in mediating the effects of RYGB and that this role is limited to its well-described action on glucose regulation. Topics: Animals; Blood Glucose; Body Weight; Diet, High-Fat; Energy Metabolism; Gastric Bypass; Glucagon-Like Peptide 1; Glucagon-Like Peptide-1 Receptor; Glucose Tolerance Test; Insulin; Insulin Resistance; Male; Mice; Obesity; Peptide Fragments; Signal Transduction | 2016 |
Short-term aerobic exercise training improves gut peptide regulation in nonalcoholic fatty liver disease.
Obesity-related nonalcoholic fatty liver disease (NAFLD) is now the most common chronic liver disease. Exercise and diet are uniformly prescribed treatments for NAFLD; however, there are limited empirical data on the effects of exercise training on metabolic function in these patients. The purpose of this study was to investigate the fasting and glucose-stimulated adaptation of gut peptides to short-term aerobic exercise training in patients with NAFLD. Twenty-two obese subjects, 16 with NAFLD [body mass index (BMI), 33.2 ± 1.1 (SE) kg/m(2)] and 6 obese controls (BMI, 31.3 ± 1.2 kg/m(2)), were enrolled in a supervised aerobic exercise program (60 min/day, 85% of their heart rate maximum, for 7 days). Fasting and glucose-stimulated glucagon-like peptide-1 (GLP-17-36) and peptide tyrosine tyrosine (PYYTotal) concentrations in plasma were assessed before and after the exercise program. Initially, the NAFLD group had higher fasting PYY (NAFLD = 117 ± 18.6, control = 47.2 ± 6.4 pg/ml, P < 0.05) and GLP-1 (NAFLD = 12.4 ± 2.2, control = 6.2 ± 0.2 pg/ml, P < 0.05) and did not significantly increase GLP-1 or PYY in response to glucose ingestion. After the exercise program, fasting GLP-1 was reduced in the NAFLD group (10.7 ± 2.0 pg/ml, P < 0.05). Furthermore, exercise training led to significant increase in the acute (0-30 min) PYY and GLP-1 responses to glucose in the NAFLD group, while the total area under the glucose-stimulated GLP-1 response curve was reduced in both NAFLD and controls (P < 0.05). In summary, 7 days of vigorous aerobic exercise normalized the dynamic PYY and GLP-1 responses to nutrient stimulation and reduced the GLP-1 response in NAFLD, suggesting that exercise positively modulates gut hormone regulation in obese adults with NAFLD. Topics: Blood Glucose; Exercise; Fasting; Female; Gastrointestinal Tract; Glucagon-Like Peptide 1; Glucose; Heart Rate; Humans; Male; Middle Aged; Non-alcoholic Fatty Liver Disease; Obesity; Peptide YY | 2016 |
A Placebo-Controlled Study on the Effects of the Glucagon-Like Peptide-1 Mimetic, Exenatide, on Insulin Secretion, Body Composition and Adipokines in Obese, Client-Owned Cats.
Glucagon-like Peptide-1 mimetics increase insulin secretion and reduces body weight in humans. In lean, healthy cats, short-term treatment has produced similar results, whereas the effect in obese cats or with extended duration of treatment is unknown. Here, prolonged (12 weeks) treatment with the Glucagon-like Peptide-1 mimetic, exenatide, was evaluated in 12 obese, but otherwise healthy, client-owned cats. Cats were randomized to exenatide (1.0 μg/kg) or placebo treatment twice daily for 12 weeks. The primary endpoint was changes in insulin concentration; the secondary endpoints were glucose homeostasis, body weight, body composition as measured by dual-energy x-ray absorptiometry and overall safety. An intravenous glucose tolerance test (1 g/kg body weight) was conducted at week 0 and week 12. Exenatide did not change the insulin concentration, plasma glucose concentration or glucose tolerance (P>0.05 for all). Exenatide tended to reduce body weight on continued normal feeding. Median relative weight loss after 12 weeks was 5.1% (range 1.7 to 8.4%) in the exenatide group versus 3.2% (range -5.3 to 5.7%) in the placebo group (P = 0.10). Body composition and adipokine levels were unaffected by exenatide (P>0.05). Twelve weeks of exenatide was well-tolerated, with only two cases of mild, self-limiting gastrointestinal signs and a single case of mild hypoglycemia. The long-term insulinotropic effect of exenatide appeared less pronounced in obese cats compared to previous short-term studies in lean cats. Further investigations are required to fully elucidate the effect on insulin secretion, glucose tolerance and body weight in obese cats. Topics: Absorptiometry, Photon; Adipokines; Adiponectin; Animals; Body Composition; Cats; Exenatide; Female; Glucagon; Glucagon-Like Peptide 1; Glucose Tolerance Test; Insulin; Insulin Secretion; Leptin; Male; Obesity; Peptides; Venoms | 2016 |
GLP-1 analogue improves hepatic lipid accumulation by inducing autophagy via AMPK/mTOR pathway.
The incidence of nonalcoholic fatty liver disease (NAFLD) keeps rising year by year, and NAFLD is rapidly becoming the most common liver disease worldwide. Clinical studies have found that glucagon-like peptide-1 (GLP-1) analogue, liraglutide (LRG), cannot only reduce glucose levels, but also improve hepatic lipase, especially in patients also with type 2 diabetes mellitus (T2DM). In addition, enhancing autophagy decreases lipid accumulation in hepatocytes. The aim of the present study is to explore the effect of LRG on hepatocyte steatosis and the possible role of autophagy. We set up an obesity mouse model with a high-fat diet (HFD) and induced hepatocyte steatosis with free fatty acids (FFA) in human L-O2 cells. LRG and two inhibitors of autophagy, Chloroquine (CQ) and bafilomycin A1 (Baf), were added into each group, respectively. The lipid profiles and morphological modifications of each group were tested. Immunohistochemistry, immunofluorescence staining and transmission electron microscopy (TEM) were used to measure autophagy in this study. The autophagy protein expression of SQSTM1 (P62), and LC3B, along with the signaling pathway proteins of mTOR, phosphorylated mTOR (p-mTOR), AMPK, phosphorylated AMPK (p-AMPK) and Beclin1, were evaluated by western blot. Our results showed that LRG improved hepatocyte steatosis by inducing autophagy, and the AMPK/mTOR pathway is involved. These findings suggest an important mechanism for the positive effects of LRG on hepatic steatosis, and provide new evidence for clinical use of LRG in NAFLD. Topics: AMP-Activated Protein Kinases; Animals; Autophagy; Cell Line; Glucagon-Like Peptide 1; Glucose; Hepatocytes; Humans; Hypoglycemic Agents; Lipid Metabolism; Lipids; Liraglutide; Liver; Male; Mice; Mice, Inbred C57BL; Non-alcoholic Fatty Liver Disease; Obesity; Signal Transduction; TOR Serine-Threonine Kinases | 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 |
Obesity alters molecular and functional cardiac responses to ischemia/reperfusion and glucagon-like peptide-1 receptor agonism.
This study tested the hypothesis that obesity alters the cardiac response to ischemia/reperfusion and/or glucagon like peptide-1 (GLP-1) receptor activation, and that these differences are associated with alterations in the obese cardiac proteome and microRNA (miRNA) transcriptome. Ossabaw swine were fed normal chow or obesogenic diet for 6 months. Cardiac function was assessed at baseline, during a 30-minutes coronary occlusion, and during 2 hours of reperfusion in anesthetized swine treated with saline or exendin-4 for 24 hours. Cardiac biopsies were obtained from normal and ischemia/reperfusion territories. Fat-fed animals were heavier, and exhibited hyperinsulinemia, hyperglycemia, and hypertriglyceridemia. Plasma troponin-I concentration (index of myocardial injury) was increased following ischemia/reperfusion and decreased by exendin-4 treatment in both groups. Ischemia/reperfusion produced reductions in systolic pressure and stroke volume in lean swine. These indices were higher in obese hearts at baseline and relatively maintained throughout ischemia/reperfusion. Exendin-4 administration increased systolic pressure in lean swine but did not affect the blood pressure in obese swine. End-diastolic volume was reduced by exendin-4 following ischemia/reperfusion in obese swine. These divergent physiologic responses were associated with obesity-related differences in proteins related to myocardial structure/function (e.g. titin) and calcium handling (e.g. SERCA2a, histidine-rich Ca(2+) binding protein). Alterations in expression of cardiac miRs in obese hearts included miR-15, miR-27, miR-130, miR-181, and let-7. Taken together, these observations validate this discovery approach and reveal novel associations that suggest previously undiscovered mechanisms contributing to the effects of obesity on the heart and contributing to the actions of GLP-1 following ischemia/reperfusion. Topics: Animals; Disease Models, Animal; Gene Expression Profiling; Glucagon-Like Peptide 1; Glucagon-Like Peptide-1 Receptor; Myocardial Reperfusion Injury; Obesity; Oligonucleotide Array Sequence Analysis; Proteomics; Swine; Transcriptome | 2016 |
Jejunal administration of glucose enhances acyl ghrelin suppression in obese humans.
Ghrelin is a gastric hormone that stimulates hunger and worsens glucose metabolism. Circulating ghrelin is decreased after Roux-en-Y gastric bypass (RYGB) surgery; however, the mechanism(s) underlying this change is unknown. We tested the hypothesis that jejunal nutrient exposure plays a significant role in ghrelin suppression after RYGB. Feeding tubes were placed in the stomach or jejunum in 13 obese subjects to simulate pre-RYGB or post-RYGB glucose exposure to the gastrointestinal (GI) tract, respectively, without the confounding effects of caloric restriction, weight loss, and surgical stress. On separate study days, the plasma glucose curves obtained with either gastric or jejunal administration of glucose were replicated with intravenous (iv) infusions of glucose. These "isoglycemic clamps" enabled us to determine the contribution of the GI tract and postabsorptive plasma glucose to acyl ghrelin suppression. Plasma acyl ghrelin levels were suppressed to a greater degree with jejunal glucose administration compared with gastric glucose administration (P < 0.05). Jejunal administration of glucose also resulted in a greater suppression of acyl ghrelin than the corresponding isoglycemic glucose infusion (P ≤ 0.01). However, gastric and isoglycemic iv glucose infusions resulted in similar degrees of acyl ghrelin suppression (P > 0.05). Direct exposure of the proximal jejunum to glucose increases acyl ghrelin suppression independent of circulating glucose levels. The enhanced suppression of acyl ghrelin after RYGB may be due to a nutrient-initiated signal in the jejunum that regulates ghrelin secretion. Topics: Adult; Blood Glucose; Female; Gastric Bypass; Gastric Inhibitory Polypeptide; Ghrelin; Glucagon-Like Peptide 1; Glucose; Glucose Clamp Technique; Humans; Infusions, Intravenous; Insulin; Jejunum; Male; Obesity | 2016 |
Do Lactation-Induced Changes in Ghrelin, Glucagon-Like Peptide-1, and Peptide YY Influence Appetite and Body Weight Regulation during the First Postpartum Year?
To determine whether fasting and meal-induced appetite-regulating hormones are altered during lactation and associated with body weight retention after childbearing, we studied 24 exclusively breastfeeding women (BMI = 25.2 ± 3.6 kg/m(2)) at 4-5 weeks postpartum and 20 never-pregnant controls (BMI = 24.0 ± 3.1 kg/m(2)). Ghrelin, PYY, GLP-1, and appetite ratings were measured before/and 150 minutes after a standardized breakfast and 60 minutes after an ad libitum lunch. Body weight/composition were measured at 6 and 12 months. Fasting and area under-the-curve responses for appetite-regulating hormones did not differ between lactating and control groups; ghrelinacyl, however, tended to track higher after the standardized breakfast in lactating women and was higher (p < 0.05) after the ad libitum lunch despite a 24% higher energy intake (p < 0.05). By 12 months, lactating women lost 5.3 ± 2.2 kg (n = 18), whereas control women (n = 15) remained weight stable (p = 0.019); fifteen of the lactating women returned to within ±2.0 kg of prepregnancy weight but three retained >6.0 kg. The retainers had greater (p < 0.05) postmeal ghrelin rebound responses following breakfast. Overall these studies do not support the hypothesis that appetite-regulating hormones are altered during lactation and associated with postpartum weight retention. Altered ghrelin responses, however, deserve further exploration. Topics: Adult; Appetite; Body Weight Maintenance; Case-Control Studies; Female; Ghrelin; Glucagon-Like Peptide 1; Humans; Lactation; Obesity; Peptide YY; Pregnancy; Puerperal Disorders | 2016 |
Increased GLP-1 response to oral glucose in pre-pubertal obese children.
Gastrointestinal hormones, such as glucagon-like peptide (GLP-1), have been hypothesized to play a role in the pathogenesis of obesity-related complications. However, few data are available in youth. The objective of this study was to investigate the GLP-1 response to oral glucose load in obese pre-pubertal children and its relationship with insulin secretion.. Ten pre-pubertal obese children [five boys; 10.5±1.6 years; body mass index-standard deviation score (BMI-SDS): 2.2±0.5] and 10 controls (eight boys; 9.9±1.2 years; BMI-SDS: -0.7±0.5) underwent a modified oral glucose tolerance test (OGTT) to evaluate post-load glucose, insulin and GLP-1 responses. Insulin sensitivity [homeostasis model assessment of insulin resistance (HOMA-IR), whole body insulin sensitivity index (WBISI)] and secretion [HOMA-beta, insulinogenic index (IGI)] indexes, area under the curve (AUC) for glucose, insulin and GLP-1 were calculated.. In obese children GLP-1 AUC values were higher and correlated with BMI-SDS (r=0.45; p=0.04), HOMA-IR (r=0.53; p=0.01) and fasting glucose (r=0.68; p=0.001).. Obese children showed an increased GLP-1 response to oral glucose. These changes might likely represent a compensatory mechanism to avoid post-prandial hyperglycemia and allow a normal glucose tolerance. Topics: Biomarkers; Case-Control Studies; Child; Female; Follow-Up Studies; Glucagon-Like Peptide 1; Glucose; Glucose Tolerance Test; Humans; Incretins; Male; Obesity; Prognosis; Puberty | 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 |
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 |
ETHNIC AND RACIAL DISPARITIES IN THE BEHAVIORAL, PHARMACOLOGIC, AND SURGICAL TREATMENT OF OBESITY.
Abbreviation: GLP-1 = glucagon-like peptide-1. Topics: Ethnicity; Glucagon-Like Peptide 1; Humans; Obesity; Racial Groups; White People | 2016 |
Differences in Regional Brain Responses to Food Ingestion After Roux-en-Y Gastric Bypass and the Role of Gut Peptides: A Neuroimaging Study.
Improved appetite control, possibly mediated by exaggerated gut peptide responses to eating, may contribute to weight loss after Roux-en-Y gastric bypass (RYGB). This study compared brain responses to food ingestion between post-RYGB (RYGB), normal weight (NW), and obese (Ob) unoperated subjects and explored the role of gut peptide responses in RYGB.. Neuroimaging with [(18)F]-fluorodeoxyglucose (FDG) positron emission tomography was performed in 12 NW, 21 Ob, and 9 RYGB (18 ± 13 months postsurgery) subjects after an overnight fast, once FED (400 kcal mixed meal), and once FASTED, in random order. RYGB subjects repeated the studies with somatostatin infusion and basal insulin replacement. Fullness, sickness, and postscan ad libitum meal consumption were measured. Regional brain FDG uptake was compared using statistical parametric mapping.. RYGB subjects had higher overall fullness and food-induced sickness and lower ad libitum consumption. Brain responses to eating differed in the hypothalamus and pituitary (exaggerated activation in RYGB), left medial orbital cortex (OC) (activation in RYGB, deactivation in NW), right dorsolateral frontal cortex (deactivation in RYGB and NW, absent in Ob), and regions mapping to the default mode network (exaggerated deactivation in RYGB). Somatostatin in RYGB reduced postprandial gut peptide responses, sickness, and medial OC activation.. RYGB induces weight loss by augmenting normal brain responses to eating in energy balance regions, restoring lost inhibitory control, and altering hedonic responses. Altered postprandial gut peptide responses primarily mediate changes in food-induced sickness and OC responses, likely to associate with food avoidance. Topics: Adult; Body Mass Index; Brain; Eating; Female; Fluorodeoxyglucose F18; Gastric Bypass; Glucagon-Like Peptide 1; Humans; Hypothalamus; Insulin; Magnetic Resonance Imaging; Male; Middle Aged; Neuroimaging; Obesity; Peptide YY; Postprandial Period; Somatostatin; Young Adult | 2016 |
Synthetic (+)-antroquinonol exhibits dual actions against insulin resistance by triggering AMP kinase and inhibiting dipeptidyl peptidase IV activities.
The fungal product (+)-antroquinonol activates AMP kinase (AMPK) activity in cancer cell lines. The present study was conducted to examine whether chemically synthesized (+)-antroquinonol exhibited beneficial metabolic effects in insulin-resistant states by activating AMPK and inhibiting dipeptidyl peptidase IV (DPP IV) activity.. Effects of (+)-antroquinonol on DPP IV activity were measured with a DPPIV Assay Kit and effects on GLP-1-induced PKA were measured in AR42J cells. Translocation of the glucose transporter 4, GLUT4, induced either by insulin-dependent PI3K/AKT signalling or by insulin-independent AMPK activation, was assayed in differentiated myotubes. Glucose uptake and GLUT4 translocation were assayed in L6 myocytes. Mice with diet-induced obesity were used to assess effects of acute and chronic treatment with (+)-antroquinonol on glycaemic control in vivo.. The results showed that of (+)-antroquinonol (100 μM ) inhibited the DPP IV activity as effectively as the clinically used inhibitor, sitagliptin. The phosphorylation of AMPK Thr(172) in differentiated myotubes was significantly increased by (+)-antroquinonol. In cells simultaneously treated with S961 (insulin receptor antagonist), insulin and (+)-antroquinonol, the combination of (+)-antroquinonol plus insulin still increased both GLUT4 translocation and glucose uptake. Further, (+)-antroquinonol and sitagliptin reduced blood glucose, when given acutely or chronically to DIO mice.. Chemically synthesized (+)-antroquinonol exhibits dual effects to ameliorate insulin resistance, by increasing AMPK activity and GLUT4 translocation, along with inhibiting DPP IV activity. Topics: AMP-Activated Protein Kinases; Animals; Caco-2 Cells; Cell Line; Cell Line, Tumor; Cyclic AMP-Dependent Protein Kinases; Dipeptidyl Peptidase 4; Dipeptidyl-Peptidase IV Inhibitors; Glucagon-Like Peptide 1; Glucose; Glucose Tolerance Test; Glucose Transporter Type 4; Humans; Insulin Resistance; Mice; Obesity; Rats; Ubiquinone | 2015 |
Roux-en-Y gastric bypass reduces lipid overaccumulation in liver by upregulating hepatic autophagy in obese diabetic rats.
The decrease in lipotoxicity is one of the crucial mechanisms by which Roux-en-Y gastric bypass (RYGB) improves insulin sensitivity. Little work, however, has been performed to elucidate the exact mechanism of RYGB reducing hepatic lipid overaccumulation in response to heavy lipid and glucose challenge. Here, we explored the effects of RYGB on hepatic autophagy in obese diabetic rats.. Sprague-Dawley rats were divided into five groups: diabetic RYGB, diabetic RYGB sham, diabetic food restriction (FR), diabetic rats, and non-diabetic controls (n = 12/group). At 4-week post-operation, genetic and protein expressions of autophagy markers including Atg7 and Beclin 1 and the conversion of LC3 were examined with quantitative RT-PCR and Western blotting. Plasma glucagon-like peptide-1 (GLP-1) and triglyceride and total cholesterol levels in liver tissue were tested.. In both genetic and protein levels, we observed a significant upregulated autophagy in liver at 4 weeks after RYGB. Restored autophagy in liver played a key role in reducing the hepatic lipid burden in obese diabetic rats. The marked increase of autophagy in liver after RYGB correlated well with the plasma GLP-1 level.. Our data demonstrate that RYGB significantly upregulated hepatic autophagy. We suggest that the effects of RYGB on autophagy in liver may be due to the increased GLP-1 level after surgery. Moreover, the activated autophagy in liver might play a key role in reducing the hepatic lipid overaccumulation after RYGB. Topics: Animals; Autophagy; Blood Glucose; Diabetes Mellitus, Experimental; Gastric Bypass; Glucagon-Like Peptide 1; Insulin Resistance; Lipid Metabolism; Liver; Male; Obesity; Rats; Rats, Sprague-Dawley; Triglycerides; Up-Regulation | 2015 |
GLP-1 plays a limited role in improved glycemia shortly after Roux-en-Y gastric bypass: a comparison with intensive lifestyle modification.
Rapid glycemic improvements following Roux-en-Y gastric bypass (RYGB) are frequently attributed to the enhanced GLP-1 response, but causality remains unclear. To determine the role of GLP-1 in improved glucose tolerance after surgery, we compared glucose and hormonal responses to a liquid meal test in 20 obese participants with type 2 diabetes mellitus who underwent RYGB or nonsurgical intensive lifestyle modification (ILM) (n = 10 per group) before and after equivalent short-term weight reduction. The GLP-1 receptor antagonist exendin(9-39)-amide (Ex-9) was administered, in random order and in double-blinded fashion, with saline during two separate visits after equivalent weight loss. Despite the markedly exaggerated GLP-1 response after RYGB, changes in postprandial glucose and insulin responses did not significantly differ between groups, and glucagon secretion was paradoxically augmented after RYGB. Hepatic insulin sensitivity also increased significantly after RYGB. With Ex-9, glucose tolerance deteriorated similarly from the saline condition in both groups, but postprandial insulin release was markedly attenuated after RYGB compared with ILM. GLP-1 exerts important insulinotropic effects after RYGB and ILM, but the enhanced incretin response plays a limited role in improved glycemia shortly after surgery. Instead, enhanced hepatic metabolism, independent of GLP-1 receptor activation, may be more important for early postsurgical glycemic improvements. Topics: Adult; Blood Glucose; Female; Gastric Bypass; Glucagon-Like Peptide 1; Humans; Incretins; Insulin; Insulin Resistance; Life Style; Male; Middle Aged; Obesity | 2015 |
Off-label antiobesity treatment in patients without diabetes with GLP-1 agonists in clinical practice.
The aim of the work was to investigate whether continuation of treatment, side effects, and effect on weight loss of GLP-1 agonists in obese patients without diabetes are equally promising in daily clinical-practice-settings compared to controlled clinical trials. Obese patients without diabetes of our interdisciplinary obesity centre were treated off-label with GLP-1-agonists for different time periods. Application was started with low-dose and increased if side effects were tolerable. Monthly costs were € 125 for daily applications of 1.2 mg liraglutide or 10 μg exenatide twice daily. Data were obtained by telephone interviews about baseline characteristics, weight loss, sensation of satiation, duration of therapy, side effects, and reasons for discontinuation. Of 43 included cases (5 males, mean age 43±11 years, mean weight 107±24 kg, mean excess weight 35±21 kg) 7 were treated with exenatide and 36 with liraglutide. Excess weight loss in linear regression models was 6.7% per month (p <0.05) under control of age, sex, initial weight, and type of GLP-1 analogue treatment and did not significantly differ between liraglutide and exenatide. Overall, 58% of patients reported side effects mostly concerning the gastrointestinal tract. Surprisingly no patient reported vomiting. One patient developed a severe pancreatitis. At time of telephone interview only 30.2% were continuing treatment. Mean treatment duration was 2.98±2.71 months. Common reasons for discontinuation of treatment were no/little effect on weight loss (27.9%), intolerable side effects (20.9%), or financial reasons (14%). GLP-1 agonist treatment in obese patients without diabetes also correlates with significant weight loss in clinical practice. However, side effects and discontinuation of treatment are common. Therefore, long-term effect on weight loss might not be as promising as suggested by data from clinical trials. Topics: Adult; Aged; Exenatide; Female; Glucagon-Like Peptide 1; Humans; Hypoglycemic Agents; Liraglutide; Male; Medication Adherence; Middle Aged; Obesity; Off-Label Use; Peptides; Treatment Outcome; Venoms; Weight Loss; Young Adult | 2015 |
Long-term effects of Roux-en-Y gastric bypass on postprandial plasma lipid and bile acids kinetics in female non diabetic subjects: A cross-sectional pilot study.
Formerly obese patients having undergone Roux-en-Y gastric bypass (RYGB) display both an accelerated digestion and absorption of carbohydrate and an increased plasma glucose clearance rate after meal ingestion. How RYGB effects postprandial kinetics of dietary lipids has yet not been investigated.. Plasma triglyceride (TG), apoB48, total apoB, bile acids (BA), fibroblast growth factor 19 (FGF19), and cholecystokinin (CCK) were measured in post-absorptive conditions and over 4-h following the ingestion of a mixed test meal in a cross-sectional, pilot study involving 11 formerly obese female patients 33.8 ± 16.4 months after RYGB surgery and in 11 weight- and age-matched female control participants.. Compared to controls, RYGB patients had faster (254 ± 14 vs. 327 ± 7 min, p < 0.05) and lower (0.14 ± 0.04 vs. 0.35 ± 0.07 mM, p < 0.05) peak TG responses, but their peak apoB48 responses tended to be higher (2692 ± 336 vs. 1841 ± 228 ng/ml, p = 0.09). Their postprandial total BA concentrations were significantly increased and peaked earlier after meal ingestion than in controls. Their FGF19 and CCK concentrations also peaked earlier and to a higher value.. The early postprandial apoB48 and BA responses indicate that RYGB accelerated the rate of dietary lipid absorption. The lower postprandial peak TG strongly suggests that the RYGB simultaneously increased the clearance of TG-rich lipoproteins.. NCT01891591. Topics: Adult; Apolipoprotein B-48; Apolipoproteins B; Bile Acids and Salts; Blood Glucose; Body Mass Index; Cholecystokinin; Cross-Sectional Studies; Female; Fibroblast Growth Factors; Gastric Bypass; Glucagon-Like Peptide 1; Humans; Insulin; Meals; Obesity; Pilot Projects; Postprandial Period; Time Factors; Triglycerides | 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 |
Liraglutide, leptin and their combined effects on feeding: additive intake reduction through common intracellular signalling mechanisms.
To investigate the behavioural and intracellular mechanisms by which the glucagon like peptide-1 (GLP-1) receptor agonist, liraglutide, and leptin in combination enhance the food intake inhibitory and weight loss effects of either treatment alone.. We examined the effects of liraglutide (a long-acting GLP-1 analogue) and leptin co-treatment, delivered in low or moderate doses subcutaneously (s.c.) or to the third ventricle, respectively, on cumulative intake, meal patterns and hypothalamic expression of intracellular signalling proteins [phosphorylated signal transducer and activator of transcription-3 (pSTAT3) and protein tyrosine phosphatase-1B (PTP1B)] in lean rats.. A low-dose combination of liraglutide (25 µg/kg) and leptin (0.75 µg) additively reduced cumulative food intake and body weight, a result mediated predominantly through a significant reduction in meal frequency that was not present with either drug alone. Liraglutide treatment alone also reduced meal size; an effect not enhanced with leptin co-administration. Moderate doses of liraglutide (75 µg/kg) and leptin (4 µg), examined separately, each reduced meal frequency, cumulative food intake and body weight; only liraglutide reduced meal size. In combination these doses did not further enhance the anorexigenic effects of either treatment alone. Ex vivo immunoblot analysis showed elevated pSTAT3 in the hypothalamic tissue after liraglutide-leptin co-treatment, an effect which was greater than that of leptin treatment alone. In addition, s.c. liraglutide reduced the expression of PTP1B (a negative regulator of leptin receptor signalling), revealing a potential mechanism for the enhanced pSTAT3 response after liraglutide-leptin co-administration.. Collectively, these results show novel behavioural and molecular mechanisms underlying the additive reduction in food intake and body weight after liraglutide-leptin combination treatment. Topics: Animals; Appetite Depressants; Body Weight; Drug Therapy, Combination; Eating; Glucagon-Like Peptide 1; Hypothalamus; Incretins; Leptin; Liraglutide; Male; Obesity; Protein Tyrosine Phosphatase, Non-Receptor Type 1; Rats; Rats, Sprague-Dawley; STAT3 Transcription Factor; Weight Loss | 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 |
Chronic Electrical Stimulation at Acupoints Reduces Body Weight and Improves Blood Glucose in Obese Rats via Autonomic Pathway.
The aim of this study was to investigate effects and mechanisms of chronic electrical stimulation at acupoints (CEA) using surgically implanted electrodes on food intake, body weight, and metabolisms in diet-induced obese (DIO) rats.. Thirty-six DIO rats were chronically implanted with electrodes at acupoints ST-36 (Zusanli). Three sets of parameters were tested: electrical acupuncture (EA) 1 (2-s on, 3-s off, 0.5 ms, 15 Hz, 6 mA), EA2 (same as EA1 but continuous pulses), and EA3 (same as EA2 but 10 mA). A chronic study was then performed to investigate the effects of CEA on body weight and mechanisms involving gastrointestinal hormones and autonomic functions.. EA2 significantly reduced food intake without uncomfortable behaviors. CEA at EA2 reduced body weight and epididymal fat pad weight (P < 0.05). CEA reduced both postprandial blood glucose and HbA1c (P < 0.05). CEA delayed gastric emptying (P < 0.03) and increased small intestinal transit (P < 0.02). CEA increased fasting plasma level of glucagon-like peptide-1 (GLP-1) and peptide YY (P < 0.05); the increase of GLP-1 was inversely correlated with postprandial blood glucose (R (2) = 0.89, P < 0.05); and the plasma ghrelin level remained unchanged. EA increased sympathetic activity (P < 0.01) and reduced vagal activity (P < 0.01).. CEA at ST-36 reduces body weight and improves blood glucose possibly attributed to multiple mechanisms involving gastrointestinal motility and hormones via the autonomic pathway. Topics: Acupuncture Points; Animals; Autonomic Nervous System; Blood Glucose; Body Weight; Eating; Electric Stimulation Therapy; Fasting; Gastrointestinal Motility; Ghrelin; Glucagon-Like Peptide 1; Male; Obesity; Obesity, Morbid; Peptide YY; Postprandial Period; Rats; Rats, Sprague-Dawley; Vagus Nerve | 2015 |
Gut microbiota and energy balance: role in obesity.
The microbial community populating the human digestive tract has been linked to the development of obesity, diabetes and liver diseases. Proposed mechanisms on how the gut microbiota could contribute to obesity and metabolic diseases include: (1) improved energy extraction from diet by the conversion of dietary fibre to SCFA; (2) increased intestinal permeability for bacterial lipopolysaccharides (LPS) in response to the consumption of high-fat diets resulting in an elevated systemic LPS level and low-grade inflammation. Animal studies indicate differences in the physiologic effects of fermentable and non-fermentable dietary fibres as well as differences in long- and short-term effects of fermentable dietary fibre. The human intestinal microbiome is enriched in genes involved in the degradation of indigestible polysaccharides. The extent to which dietary fibres are fermented and in which molar ratio SCFA are formed depends on their physicochemical properties and on the individual microbiome. Acetate and propionate play an important role in lipid and glucose metabolism. Acetate serves as a substrate for de novo lipogenesis in liver, whereas propionate can be utilised for gluconeogenesis. The conversion of fermentable dietary fibre to SCFA provides additional energy to the host which could promote obesity. However, epidemiologic studies indicate that diets rich in fibre rather prevent than promote obesity development. This may be due to the fact that SCFA are also ligands of free fatty acid receptors (FFAR). Activation of FFAR leads to an increased expression and secretion of enteroendocrine hormones such as glucagon-like-peptide 1 or peptide YY which cause satiety. In conclusion, the role of SCFA in host energy balance needs to be re-evaluated. Topics: Animals; Dietary Fiber; Energy Metabolism; Fatty Acids, Volatile; Gastrointestinal Microbiome; Glucagon-Like Peptide 1; Glucose; Humans; Incretins; Inflammation; Intestinal Mucosa; Intestines; Lipid Metabolism; Lipopolysaccharides; Obesity; Peptide YY; Permeability; Satiation | 2015 |
Side-to-Side Jejunoileal Bypass Induces Better Glucose-Lowering Effect than End-to-Side Jejunoileal Bypass on Nonobese Diabetic Rats.
Jejunoileal bypass (JIB) can markedly ameliorate diabetes in obese patients and rodents. The aim of this study is to systematically evaluate the role of the operational manner and the retained distal small bowel length in mediating changes in glucose homeostasis after intestinal bypass surgeries in nonobese diabetic rats.. Streptozotocin-induced diabetic rats underwent side-to-side jejunoileal bypass plus proximal loop ligation (SSJIBL), end-to-side jejunoileal bypass (ESJIB), proximal small bowel resection (PBR), and sham operation. Each operational manner included two subgroups, in which 30 cm (L-30) or 40 cm (L-40) distal small bowel was retained. Main outcome measures were fasting blood glucose levels (FBG), insulin sensitivity, serum insulin, glucagon-like peptide-1 (GLP-1), bilirubin (BIL), and total bile acids (TBA) levels.. Global food intake in the sham group was higher than in the operation groups, and global body weight and food intake in the SSJIBL group were higher than in the ESJIB and PBR groups. Global body weight and food intake in L-40 group were higher than in L-30 group. The SSJIBL procedure induced better improvement in glucose homeostasis and insulin sensitivity than the ESJIB and PBR procedures, and L-30 group showed better antidiabetic effects than L-40 group. Serum GLP-1, BIL, and TBA levels in SSJIBL group were higher than in ESJIB and PBR groups.. This study shows that side-to-side jejunoileal bypass induced better glucose-lowering effects than end-to-side jejunoileal bypass and proximal small bowel resection, and intestinal bypass surgery that retained shorter distal small bowel yielded better antidiabetic effects. Topics: Anastomosis, Surgical; Animals; Blood Glucose; Diabetes Mellitus, Experimental; Down-Regulation; Eating; Glucagon-Like Peptide 1; Intestine, Small; Jejunoileal Bypass; Male; Obesity; Rats; Rats, Sprague-Dawley; Streptozocin | 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 |
Diurnal rhythms of plasma GLP-1 levels in normal and overweight/obese subjects: lack of effect of weight loss.
Food intake is regulated by not only neurohormonal, but also social, educational, and even cultural factors. Within the former, there is a complex interaction between orexigenic (ghrelin) and anorexigenic (glucagon-like peptide-1 (GLP-1)) factors in order to adjust the food intake to caloric expenditure; however, the number of subjects that are unable to properly balance appetite and body weight is increasing continuously. A loss of circadian or diurnal coordination of any of these factors may be implied in this situation. Special attention has retrieved GLP-1 due to its usefulness as a therapeutic agent against obesity and related alterations. Thus, the objective of the present study was to compare GLP-1 diurnal synthesis between normal weight and overweight/obese subjects, and to evaluate whether weight loss can restore the synthesis rhythms of GLP-1. Three groups of 25 subjects were divided attending to their body mass index (BMI) in normal weight, overweight, or obese subjects. Diurnal (5 points) GLP-1 levels were analyzed. Secondly, an intervention (behavioral-dietary treatment) study was conducted to analyze the effect of weight loss on plasma GLP-1 concentrations. Our results showed that baseline GLP-1 level was significantly lower in normal weight subjects (p = 0.003); furthermore, our cosinor analysis revealed a higher amplitude (p = 0.040) and daily GLP-1 variation (47%) in these subjects. In fact, our ANOVA data showed a lack of rhythmicity in overweight/obese patients. Weight loss was not able to restore a diurnal rhythm of plasma GLP-1 levels. In summary, the present work shows a disruption of diurnal GLP-1 levels in overweight/obese subjects, which worsen as body fat progresses. The attenuation of the GLP-1 synthesis rhythms may be important to understand the impairment of food intake regulation in overweight/obese subjects. Topics: Adult; Caloric Restriction; Case-Control Studies; Circadian Rhythm; Female; Glucagon-Like Peptide 1; Humans; Male; Obesity; Overweight; Weight Loss; Young Adult | 2015 |
Anti-obesogenic effects of calcium prevent changes in the GLP-1 profile in adult rats primed by early weaning.
Gut peptides regulate appetite and adipogenesis. Early weaning (EW) leads to later development of obesity that can be prevented by calcium supplementation. We evaluated gut peptides that may have a role in the establishment of this dysfunction.. At birth, lactating Wistar rats were separated in: EW, lactating rats involved with a bandage interrupting the lactation during the last 4 days of standard lactation, and C (control) dams whose pups had free access to milk during throughout lactation. At 120 days old, half of EW group received calcium supplementation (EWCa); EW and C received standard diet. At 21 days old, EW presented higher glucagon-like peptide 1 (GLP-1) in plasma and glucagon-like peptide 1 receptor (GLP1-R) in adipose tissue and hypothalamus, but lower GLP-1 and GLP1-R in the gut. At 180 days old, GLP-1 response to food intake was blunted in EW and restored by calcium. GLP-1 in the gut was lower in EW and its receptor was lower in adipose tissue, and GLP1-R was higher in the gut of calcium EW group.. Thus, EW had short- and long-term effects upon GLP-1 profile, which may have contributed to obesity development, hyperphagia, and insulin resistance due to its adipogenic and appetite control roles. Calcium supplementation was able to prevent most of the changes in GLP-1 caused by EW. Topics: Adipose Tissue; Animals; Anti-Obesity Agents; Body Composition; Body Mass Index; Calcium Carbonate; Calcium, Dietary; Female; Gastrointestinal Tract; Ghrelin; Glucagon-Like Peptide 1; Glucagon-Like Peptide-1 Receptor; Hyperphagia; Hypothalamus; Insulin Resistance; Lactation; Male; Nutritional Status; Obesity; Rats; Rats, Wistar; Weaning | 2015 |
Hunger games: is your stomach making you fat?
Topics: Dipeptides; Fasting; Female; Gastric Emptying; Glucagon-Like Peptide 1; Humans; Male; Obesity; Postprandial Period; Satiation; Stomach | 2015 |
Anorexigenic lipopeptides ameliorate central insulin signaling and attenuate tau phosphorylation in hippocampi of mice with monosodium glutamate-induced obesity.
Numerous epidemiological and experimental studies have demonstrated that patients who suffer from metabolic disorders, such as type 2 diabetes mellitus (T2DM) or obesity, have higher risks of cognitive dysfunction and of Alzheimer's disease (AD). Impaired insulin signaling in the brain could contribute to the formation of neurofibrillary tangles, which contain an abnormally hyperphosphorylated tau protein. This study aimed to determine whether potential tau hyperphosphorylation could be detected in an obesity-induced pre-diabetes state and whether anorexigenic agents could affect this state. We demonstrated that 6-month-old mice with monosodium glutamate (MSG) obesity, which represent a model of obesity-induced pre-diabetes, had increased tau phosphorylation at Ser396 and Thr231 in the hippocampus compared with the controls, as determined by western blots. Two weeks of subcutaneous treatment with a lipidized analog of prolactin-releasing peptide (palm-PrRP31) or with the T2DM drug liraglutide, which both had a central anorexigenic effect, resulted in increased phosphorylation of the insulin cascade kinases PDK1 (Ser241), Akt (Thr308), and GSK-3β (Ser9). Furthermore, these drugs attenuated phosphorylation at Ser396, Thr231, and Thr212 of tau and of the primary tau kinases in the hippocampi of 6-month-old MSG-obese mice. We identified tau hyperphosphorylation in the obesity-induced pre-diabetes state in MSG-obese mice and demonstrated the beneficial effects of palm-PrRP31 and liraglutide, both of known central anorexigenic effects, on hippocampal insulin signaling and on tau phosphorylation. Topics: Analysis of Variance; Animals; Body Weight; Disease Models, Animal; Flavoring Agents; Glucagon-Like Peptide 1; Glucose Tolerance Test; Hippocampus; Insulins; Lipopeptides; Male; Mice; Obesity; Phosphorylation; Prolactin-Releasing Hormone; Receptors, G-Protein-Coupled; Signal Transduction; Sodium Glutamate; tau Proteins; Time Factors | 2015 |
Dual melanocortin-4 receptor and GLP-1 receptor agonism amplifies metabolic benefits in diet-induced obese mice.
We assessed the efficacy of simultaneous agonism at the glucagon-like peptide-1 receptor (GLP-1R) and the melanocortin-4 receptor (MC4R) for the treatment of obesity and diabetes in rodents. Diet-induced obese (DIO) mice were chronically treated with either the long-acting GLP-1R agonist liraglutide, the MC4R agonist RM-493 or a combination of RM-493 and liraglutide. Co-treatment of DIO mice with RM-493 and liraglutide improves body weight loss and enhances glycemic control and cholesterol metabolism beyond what can be achieved with either mono-therapy. The superior metabolic efficacy of this combination therapy is attributed to the anorectic and glycemic actions of both drugs, along with the ability of RM-493 to increase energy expenditure. Interestingly, compared to mice treated with liraglutide alone, hypothalamic Glp-1r expression was higher in mice treated with the combination therapy after both acute and chronic treatment. Further, RM-493 enhanced hypothalamic Mc4r expression. Hence, co-dosing with MC4R and GLP-1R agonists increases expression of each receptor, indicative of minimized receptor desensitization. Together, these findings suggest potential opportunities for employing combination treatments that comprise parallel MC4R and GLP-1R agonism for the treatment of obesity and diabetes. Topics: alpha-MSH; Animals; Diabetes Mellitus; Drug Synergism; Drug Therapy, Combination; Glucagon-Like Peptide 1; Glucagon-Like Peptide-1 Receptor; Hypoglycemic Agents; Liraglutide; Mice, Obese; Obesity; Receptor, Melanocortin, Type 4; Receptors, Glucagon; Treatment Outcome | 2015 |
Bariatric surgery: "Roux"-minating on endothelial cell and high-density lipoprotein function.
Topics: Animals; Body Weight; Endothelium, Vascular; Female; Gastric Bypass; Glucagon-Like Peptide 1; Humans; Lipoproteins, HDL; Male; Obesity; Weight Loss | 2015 |
Rapid and body weight-independent improvement of endothelial and high-density lipoprotein function after Roux-en-Y gastric bypass: role of glucagon-like peptide-1.
Roux-en-Y gastric bypass (RYGB) reduces body weight and cardiovascular mortality in morbidly obese patients. Glucagon-like peptide-1 (GLP-1) seems to mediate the metabolic benefits of RYGB partly in a weight loss-independent manner. The present study investigated in rats and patients whether obesity-induced endothelial and high-density lipoprotein (HDL) dysfunction is rapidly improved after RYGB via a GLP-1-dependent mechanism.. Eight days after RYGB in diet-induced obese rats, higher plasma levels of bile acids and GLP-1 were associated with improved endothelium-dependent relaxation compared with sham-operated controls fed ad libitum and sham-operated rats that were weight matched to those undergoing RYGB. Compared with the sham-operated rats, RYGB improved nitric oxide (NO) bioavailability resulting from higher endothelial Akt/NO synthase activation, reduced c-Jun amino terminal kinase phosphorylation, and decreased oxidative stress. The protective effects of RYGB were prevented by the GLP-1 receptor antagonist exendin9-39 (10 μg·kg(-1)·h(-1)). Furthermore, in patients and rats, RYGB rapidly reversed HDL dysfunction and restored the endothelium-protective properties of the lipoprotein, including endothelial NO synthase activation, NO production, and anti-inflammatory, antiapoptotic, and antioxidant effects. Finally, RYGB restored HDL-mediated cholesterol efflux capacity. To demonstrate the role of increased GLP-1 signaling, sham-operated control rats were treated for 8 days with the GLP-1 analog liraglutide (0.2 mg/kg twice daily), which restored NO bioavailability and improved endothelium-dependent relaxations and HDL endothelium-protective properties, mimicking the effects of RYGB.. RYGB rapidly reverses obesity-induced endothelial dysfunction and restores the endothelium-protective properties of HDL via a GLP-1-mediated mechanism. The present translational findings in rats and patients unmask novel, weight-independent mechanisms of cardiovascular protection in morbid obesity. Topics: Adult; Animals; Antioxidants; Body Weight; Case-Control Studies; Cells, Cultured; Diet, High-Fat; Disease Models, Animal; Endothelium, Vascular; Female; Gastric Bypass; Glucagon-Like Peptide 1; Humans; Lipoproteins, HDL; Male; Nitric Oxide; Obesity; Oxidative Stress; Proto-Oncogene Proteins c-akt; Rats; Rats, Wistar; Signal Transduction; Treatment Outcome; Weight Loss | 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 |
Mechanism of action of hypoglycemic effects of an intestine-specific inhibitor of microsomal triglyceride transfer protein (MTP) in obese rats.
Diminished insulin sensitivity in the peripheral tissues and failure of pancreatic beta cells to secrete insulin are known major determinants of type 2 diabetes mellitus. JTT-130, an intestine-specific microsomal transfer protein inhibitor, has been shown to suppress high fat-induced obesity and ameliorate impaired glucose tolerance while enhancing glucagon-like peptide-1 (GLP-1) secretion. We investigated the effects of JTT-130 on glucose metabolism and elucidated the mechanism of action, direct effects on insulin sensitivity and glucose-stimulated insulin secretion in a high fat diet-induced obesity rat model. Male Sprague Dawley rats fed a high-fat diet were treated with a single administration of JTT-130. Glucose tolerance, hyperglycemic clamp and hyperinsulinemic-euglycemic testing were performed to assess effects on insulin sensitivity and glucose-stimulated insulin secretion, respectively. Plasma GLP-1 and tissue triglyceride content were also determined under the same conditions. A single administration of JTT-130 suppressed plasma glucose elevations after oral glucose loading and increased the disposition index while elevating GLP-1. JTT-130 also enhanced glucose-stimulated insulin secretion in hyperglycemic clamp tests, whereas increased insulin sensitivity was observed in hyperinsulinemic-euglycemic clamp tests. Single-dose administration of JTT-130 decreased lipid content in the liver and skeletal muscle. JTT-130 demonstrated acute and direct hypoglycemic effects by enhancing insulin secretion and/or insulin sensitivity. Topics: Animals; Benzamides; Blood Glucose; Carrier Proteins; Diet, High-Fat; Glucagon-Like Peptide 1; Glucose Clamp Technique; Glucose Tolerance Test; Hypoglycemic Agents; Insulin; Insulin Resistance; Lipid Metabolism; Liver; Male; Malonates; Muscle, Skeletal; Obesity; Rats; Triglycerides | 2015 |
Alteration of gut microbiota by vancomycin and bacitracin improves insulin resistance via glucagon-like peptide 1 in diet-induced obesity.
Firmicutes and Bacteroidetes, 2 major phyla of gut microbiota, are involved in lipid and bile acid metabolism to maintain systemic energy homeostasis in host. Recently, accumulating evidence has suggested that dietary changes promptly induce the alteration of abundance of both Firmicutes and Bacteroidetes in obesity and its related metabolic diseases. Nevertheless, the metabolic roles of Firmicutes and Bacteroidetes on such disease states remain unclear. The aim of this study was to determine the effects of antibiotic-induced depletion of Firmicutes and Bacteroidetes on dysregulation of energy homeostasis in obesity. Treatment of C57BL/6J mice with the antibiotics (vancomycin [V] and bacitracin [B]), in the drinking water, before diet-induced obesity (DIO) greatly decreased both Firmicutes and Bacteroidetes in the gut as revealed by pyrosequencing of the microbial 16S rRNA gene. Concomitantly, systemic glucose intolerance, hyperinsulinemia, and insulin resistance in DIO were ameliorated via augmentation of GLP-1 secretion (active form; 2.03-fold, total form; 5.09-fold) independently of obesity as compared with untreated DIO controls. Furthermore, there were increases in metabolically beneficial metabolites derived from the gut. Together, our data suggest that Firmicutes and Bacteroidetes potentially mediate insulin resistance through modulation of GLP-1 secretion in obesity. Topics: Animals; Anti-Bacterial Agents; Bacitracin; Bacteroidetes; Blood Glucose; Blotting, Western; Cell Line, Tumor; Diet, High-Fat; Gastrointestinal Tract; Glucagon-Like Peptide 1; Gram-Positive Bacteria; Humans; Insulin; Insulin Resistance; Metabolomics; Mice, Inbred C57BL; Microbiota; Obesity; RNA, Ribosomal, 16S; Sequence Analysis, DNA; Vancomycin | 2015 |
Synergistic Effects of a GPR119 Agonist with Metformin on Weight Loss in Diet-Induced Obese Mice.
G protein-coupled receptor 119 (GPR119) is a G protein-coupled receptor expressed predominantly in pancreatic β-cells and gastrointestinal enteroendocrine cells. Metformin is a first-line treatment of type 2 diabetes, with minimal weight loss in humans. In this study, we investigated the effects of GSK2041706 [2-([(1S)-1-(1-[3-(1-methylethyl)-1,2,4-oxadiazol-5-yl]-4-piperidinyl)ethyl]oxy)-5-[4-(methylsulfonyl)phenyl]pyrazine], a GPR119 agonist, and metformin as monotherapy or in combination on body weight in a diet-induced obese (DIO) mouse model. Relative to vehicle controls, 14-day treatment with GSK2041706 (30 mg/kg b.i.d.) or metformin at 30 and 100 mg/kg b.i.d. alone caused a 7.4%, 3.5%, and 4.4% (all P < 0.05) weight loss, respectively. The combination of GSK2041706 with metformin at 30 or 100 mg/kg resulted in a 9.5% and 16.7% weight loss, respectively. The combination of GSK2041706 and metformin at 100 mg/kg caused a significantly greater weight loss than the projected additive weight loss of 11.8%. This body weight effect was predominantly due to a loss of fat. Cumulative food intake was reduced by 17.1% with GSK2041706 alone and 6.6% and 8.7% with metformin at 30 and 100 mg/kg, respectively. The combination of GSK2041706 with metformin caused greater reductions in cumulative food intake (22.2% at 30 mg/kg and 37.5% at 100 mg/kg) and higher fed plasma glucagon-like peptide 1 and peptide tyrosine tyrosine levels and decreased plasma insulin and glucose-dependent insulinotropic polypeptide levels compared with their monotherapy groups. In addition, we characterized the effect of GSK2041706 and metformin as monotherapy or in combination on neuronal activation in the appetite regulating centers in fasted DIO mice. In conclusion, our data demonstrate the beneficial effects of combining a GPR119 agonist with metformin in the regulation of body weight in DIO mice. Topics: Animals; Body Weight; Diet, High-Fat; Dose-Response Relationship, Drug; Drug Synergism; Eating; Gastric Inhibitory Polypeptide; Glucagon-Like Peptide 1; Hypoglycemic Agents; Insulin; Male; Metformin; Mice; Mice, Inbred C57BL; Mice, Obese; Obesity; Oxadiazoles; Proto-Oncogene Proteins c-fos; Pyrazines; Receptors, G-Protein-Coupled; Weight Loss | 2015 |
Gut microbiota: Firmicutes and Bacteroidetes involved in insulin resistance by mediating levels of glucagon-like peptide 1.
Topics: Animals; Anti-Bacterial Agents; Gastrointestinal Tract; Glucagon-Like Peptide 1; Humans; Insulin Resistance; Microbiota; Obesity | 2015 |
Cardiovascular Changes After Gastric Bypass Surgery: Involvement of Increased Secretions of Glucagon-Like Peptide-1 and Brain Natriuretic Peptide.
Obesity induces cardiovascular alterations, including cardiac hypertrophy, impaired relaxation, and heart rate variability (HRV), which are associated with increased mortality. Gastric bypass surgery (GBP) reduces cardiovascular mortality, but the mechanisms involved are not clearly established. To date, the implication of postsurgical hormonal changes has not been tested. Our aim was to study the relationships between the evolution of cardiovascular functions after GBP and changes in metabolic and hormonal parameters, including glucagon-like peptide-1 (GLP-1) and brain natriuretic peptide (N-terminal pro-brain natriuretic peptide (NT-proBNP)).. Echocardiographic parameters, 24-h rhythmic Holter recording, plasma concentrations of GLP-1 before and after a test meal, and fasting NT-proBNP were assessed in 34 patients (M/F 2/32, age 36 ± 11 years, BMI 46 ± 6 kg/m(2)), before and 1 year after GBP.. After GBP, excess weight loss was 79 ± 20%. Blood pressure (BP), heart rate, and left ventricular mass decreased, while HRV and diastolic function (E/A ratio) improved. Plasma concentrations of NT-proBNP and postprandial (PP) GLP-1 increased. Changes in cardiovascular parameters were related to BMI and insulin sensitivity. Furthermore, the decrease in BP was independently associated with the increase of PP GLP-1 level and HRV was positively associated with NT-proBNP concentration after surgery.. The increase in endogenous GLP-1 observed after GBP was associated with decreased BP but not with improvement of other cardiovascular parameters, whereas the increase in NT-proBNP, within the physiological range, was associated with improved HRV. Topics: Adult; Blood Pressure; Female; Gastric Bypass; Glucagon-Like Peptide 1; Heart Rate; Humans; Male; Middle Aged; Natriuretic Peptide, Brain; Obesity; Peptide Fragments; Weight Loss | 2015 |
Interactive effects of oligofructose and obesity predisposition on gut hormones and microbiota in diet-induced obese rats.
Oligofructose (OFS) is a prebiotic that reduces energy intake and fat mass via changes in gut satiety hormones and microbiota. The effects of OFS may vary depending on predisposition to obesity. The aim of this study was to examine the effect of OFS in diet-induced obese (DIO) and diet-resistant (DR) rats.. Adult, male DIO, and DR rats were randomized to: high-fat/high-sucrose (HFS) diet or HFS diet + 10% OFS for 6 weeks. Body composition, food intake, gut microbiota, plasma gut hormones, and cannabinoid CB(1) receptor expression in the nodose ganglia were measured.. OFS reduced body weight, energy intake, and fat mass in both phenotypes (P < 0.05). Select gut microbiota differed in DIO versus DR rats (P < 0.05), the differences being eliminated by OFS. OFS did not modify plasma ghrelin or CB(1) expression in nodose ganglia, but plasma levels of GIP were reduced and PYY were elevated (P < 0.05) by OFS.. OFS was able to reduce body weight and adiposity in both prone and resistant obese phenotypes. OFS-induced changes in gut microbiota profiles in DIO and DR rats, along with changes in gut hormone levels, likely contribute to the sustained lower body weights. Topics: Adiposity; Animals; Body Composition; Body Weight; Diet; Dietary Fats; Eating; Gastrointestinal Hormones; Ghrelin; Glucagon-Like Peptide 1; Male; Microbiota; Obesity; Oligosaccharides; Prebiotics; Rats; Rats, Sprague-Dawley; Satiation | 2015 |
Postprandial glucagon-like peptide-1 secretion is increased during the progression of glucose intolerance and obesity in high-fat/high-sucrose diet-fed rats.
Glucagon-like peptide-1 (GLP-1) is secreted by distal enteroendocrine cells in response to luminal nutrients, and exerts insulinotropic and anorexigenic effects. Although GLP-1 secretory responses under established obese or diabetic conditions have been studied, it has not been investigated whether or how postprandial GLP-1 responses were affected during the progression of diet-induced obesity. In the present study, a meal tolerance test was performed every week in rats fed a high-fat and high-sucrose (HF/HS) diet to evaluate postprandial glycaemic, insulin and GLP-1 responses. In addition, gastric emptying was assessed by the acetaminophen method. After 8 weeks of HF/HS treatment, portal vein and intestinal mucosa were collected to examine GLP-1 production. Postprandial glucose in response to normal meal ingestion was increased in the HF/HS group within 2 weeks, and its elevation gradually returned close to that of the control group until day 50. Slower postprandial gastric emptying was observed in the HF/HS group on days 6, 13 and 34. Postprandial GLP-1 and insulin responses were increased in the HF/HS group at 7 weeks. Higher portal GLP-1 and insulin levels were observed in the HF/HS group, but mucosal gut hormone mRNA levels were unchanged. These results revealed that the postprandial GLP-1 response to meal ingestion is enhanced during the progression of diet-induced glucose intolerance and obesity in rats. The boosted postprandial GLP-1 secretion by chronic HF/HS diet treatment suggests increased sensitivity to luminal nutrients in the gut, and this may slow the establishment of glucose intolerance and obesity. Topics: Animals; Blood Glucose; Body Composition; Body Fat Distribution; Cholecystokinin; Diet; Diet, High-Fat; Gastric Emptying; Gastrointestinal Tract; Glucagon-Like Peptide 1; Glucose Intolerance; Insulin; Insulin Resistance; Male; Obesity; Postprandial Period; Rats; Rats, Sprague-Dawley; RNA, Messenger; Sucrose | 2015 |
Central 5-HT neurotransmission modulates weight loss following gastric bypass surgery in obese individuals.
The cerebral serotonin (5-HT) system shows distinct differences in obesity compared with the lean state. Here, it was investigated whether serotonergic neurotransmission in obesity is a stable trait or changes in association with weight loss induced by Roux-in-Y gastric bypass (RYGB) surgery. In vivo cerebral 5-HT2A receptor and 5-HT transporter binding was determined by positron emission tomography in 21 obese [four men; body mass index (BMI), 40.1 ± 4.1 kg/m(2)] and 10 lean (three men; BMI, 24.6 ± 1.5 kg/m(2)) individuals. Fourteen obese individuals were re-examined after RYGB surgery. First, it was confirmed that obese individuals have higher cerebral 5-HT2A receptor binding than lean individuals. Importantly, we found that higher presurgical 5-HT2A receptor binding predicted greater weight loss after RYGB and that the change in 5-HT2A receptor and 5-HT transporter binding correlated with weight loss after RYGB. The changes in the 5-HT neurotransmission before and after RYGB are in accordance with a model wherein the cerebral extracellular 5-HT level modulates the regulation of body weight. Our findings support that the cerebral 5-HT system contributes both to establish the obese condition and to regulate the body weight in response to RYGB. Topics: Adult; Body Mass Index; Brain; Brain Mapping; Case-Control Studies; Denmark; Female; Gastric Bypass; Glucagon-Like Peptide 1; Humans; Ketanserin; Male; Middle Aged; Obesity; Protein Binding; Radionuclide Imaging; Receptor, Serotonin, 5-HT2A; Serotonin Antagonists; Time Factors; Treatment Outcome; Weight Loss | 2015 |
GLP-1(32-36)amide Pentapeptide Increases Basal Energy Expenditure and Inhibits Weight Gain in Obese Mice.
The prevalence of obesity-related diabetes is increasing worldwide. Here we report the identification of a pentapeptide, GLP-1(32-36)amide (LVKGRamide), derived from the glucoincretin hormone GLP-1, that increases basal energy expenditure and curtails the development of obesity, insulin resistance, diabetes, and hepatic steatosis in diet-induced obese mice. The pentapeptide inhibited weight gain, reduced fat mass without change in energy intake, and increased basal energy expenditure independent of physical activity. Analyses of tissues from peptide-treated mice reveal increased expression of UCP-1 and UCP-3 in brown adipose tissue and increased UCP-3 and inhibition of acetyl-CoA carboxylase in skeletal muscle, findings consistent with increased fatty acid oxidation and thermogenesis. In palmitate-treated C2C12 skeletal myotubes, GLP-1(32-36)amide activated AMPK and inhibited acetyl-CoA carboxylase, suggesting activation of fat metabolism in response to energy depletion. By mass spectroscopy, the pentapeptide is rapidly formed from GLP-1(9-36)amide, the major form of GLP-1 in the circulation of mice. These findings suggest that the reported insulin-like actions of GLP-1 receptor agonists that occur independently of the GLP-1 receptor might be mediated by the pentapeptide, and the previously reported nonapeptide (FIAWLVKGRamide). We propose that by increasing basal energy expenditure, GLP-1(32-36)amide might be a useful treatment for human obesity and associated metabolic disorders. Topics: Animals; Basal Metabolism; Cells, Cultured; Diet, High-Fat; Energy Metabolism; Fatty Acids; Glucagon-Like Peptide 1; Humans; Hyperglycemia; Hyperinsulinism; Male; Mice; Mice, Inbred C57BL; Mice, Obese; Muscle, Skeletal; Obesity; Weight Gain | 2015 |
Plasma levels of glucagon-like peptide 1 and markers of obesity among young and healthy adults.
Glucagon-like peptide 1 (GLP-1)-related pathways may partially explain the strong relationship between obesity and type 2 diabetes. We therefore aimed to evaluate the relationships between fasting GLP-1 levels, body fat mass and other obesity markers in a large sample of young and healthy adults.. Our population-based study included 2096 individuals aged 24-44. Exclusion criteria were prevalent cardiovascular disease, diabetes or a body mass index (BMI) >35 kg/m(2) . Body fat mass was obtained by bioelectrical impedance analysis. Multivariable linear regression models were constructed to assess the relationships of GLP-1 with various measures of body composition.. Median age of our population was 37 years, median BMI 24·1 kg/m(2) and median body fat 25·1%. A strong positive correlation was observed in age-adjusted models between GLP-1 and fat mass in men (β (95% confidence interval) 1·38 (0·69; 2·07), P < 0·001) and women (1·27 (0·65; 1·89), P < 0·001) as well as fully adjusted models including BMI in men [0·87 (0·27; 1·46), P < 0·01] but not women [0·29 (-0·07; 0·64), P = 0·11]. The relationships of GLP-1 with BMI for men and women [0·00 (-0·34; 0·34), P = 0·99] [-0·02 (-0·28; 0·25), P = 0·91] and waist circumference [0·43 (-0·45; 1·30), P = 0·34] [0·37 (-0·44; 1·18), P = 0·37], respectively, were not significant after multivariable adjustment including fat mass.. Among young and healthy adults, GLP-1 levels are strongly and independently related to body fat mass especially in men but not BMI or waist circumference. These results raise the hypothesis that GLP-1 may be implicated in body fat mass regulation. Topics: Adult; Body Mass Index; Female; Glucagon-Like Peptide 1; Humans; Male; Obesity; Waist Circumference | 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 |
Glucagon-Like Peptide-1 Regulates Cholecystokinin Production in β-Cells to Protect From Apoptosis.
Cholecystokinin (CCK) is a classic gut hormone that is also expressed in the pancreatic islet, where it is highly up-regulated with obesity. Loss of CCK results in increased β-cell apoptosis in obese mice. Similarly, islet α-cells produce increased amounts of another gut peptide, glucagon-like peptide 1 (GLP-1), in response to cytokine and nutrient stimulation. GLP-1 also protects β-cells from apoptosis via cAMP-mediated mechanisms. Therefore, we hypothesized that the activation of islet-derived CCK and GLP-1 may be linked. We show here that both human and mouse islets secrete active GLP-1 as a function of body mass index/obesity. Furthermore, GLP-1 can rapidly stimulate β-cell CCK production and secretion through direct targeting by the cAMP-modulated transcription factor, cAMP response element binding protein (CREB). We find that cAMP-mediated signaling is required for Cck expression, but CCK regulation by cAMP does not require stimulatory levels of glucose or insulin secretion. We also show that CREB directly targets the Cck promoter in islets from obese (Leptin(ob/ob)) mice. Finally, we demonstrate that the ability of GLP-1 to protect β-cells from cytokine-induced apoptosis is partially dependent on CCK receptor signaling. Taken together, our work suggests that in obesity, active GLP-1 produced in the islet stimulates CCK production and secretion in a paracrine manner via cAMP and CREB. This intraislet incretin loop may be one mechanism whereby GLP-1 protects β-cells from apoptosis. Topics: Animals; Apoptosis; Base Sequence; Body Mass Index; Cell Line, Tumor; Cholecystokinin; Cyclic AMP; Cyclic AMP Response Element-Binding Protein; Cytoprotection; Glucagon-Like Peptide 1; Humans; Insulin; Insulin Secretion; Insulin-Secreting Cells; Mice; Molecular Sequence Data; Obesity; Phosphorylation; Promoter Regions, Genetic; Protein Binding; Rats; Receptors, Cholecystokinin | 2015 |
Dual actions of a novel bifunctional compound to lower glucose in mice with diet-induced insulin resistance.
Docosahexaenoic acid (DHA 22:6n-3) and salicylate are both known to exert anti-inflammatory effects. This study investigated the effects of a novel bifunctional drug compound consisting of DHA and salicylate linked together by a small molecule that is stable in plasma but hydrolyzed in the cytoplasm. The components of the bifunctional compound acted synergistically to reduce inflammation mediated via nuclear factor κB in cultured macrophages. Notably, oral administration of the bifunctional compound acted in two distinct ways to mitigate hyperglycemia in high-fat diet-induced insulin resistance. In mice with diet-induced obesity, the compound lowered blood glucose by reducing hepatic insulin resistance. It also had an immediate glucose-lowering effect that was secondary to enhanced glucagon-like peptide-1 (GLP-1) secretion and abrogated by the administration of exendin(9-39), a GLP-1 receptor antagonist. These results suggest that the bifunctional compound could be an effective treatment for individuals with type 2 diabetes and insulin resistance. This strategy could also be employed in other disease conditions characterized by chronic inflammation. Topics: Administration, Oral; Animals; Anti-Inflammatory Agents, Non-Steroidal; Blood Glucose; Cell Line, Transformed; Cell Line, Tumor; Cells, Cultured; Diet, High-Fat; Docosahexaenoic Acids; Glucagon-Like Peptide 1; Humans; Hypoglycemic Agents; Insulin Resistance; Liver; Macrophages; Mice, Inbred C57BL; Obesity; Prediabetic State; Prodrugs; Salicylates; Signal Transduction | 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 |
Estrogen receptor-α in medial amygdala neurons regulates body weight.
Estrogen receptor-α (ERα) activity in the brain prevents obesity in both males and females. However, the ERα-expressing neural populations that regulate body weight remain to be fully elucidated. Here we showed that single-minded-1 (SIM1) neurons in the medial amygdala (MeA) express abundant levels of ERα. Specific deletion of the gene encoding ERα (Esr1) from SIM1 neurons, which are mostly within the MeA, caused hypoactivity and obesity in both male and female mice fed with regular chow, increased susceptibility to diet-induced obesity (DIO) in males but not in females, and blunted the body weight-lowering effects of a glucagon-like peptide-1-estrogen (GLP-1-estrogen) conjugate. Furthermore, selective adeno-associated virus-mediated deletion of Esr1 in the MeA of adult male mice produced a rapid body weight gain that was associated with remarkable reductions in physical activity but did not alter food intake. Conversely, overexpression of ERα in the MeA markedly reduced the severity of DIO in male mice. Finally, an ERα agonist depolarized MeA SIM1 neurons and increased their firing rate, and designer receptors exclusively activated by designer drug-mediated (DREADD-mediated) activation of these neurons increased physical activity in mice. Collectively, our results support a model where ERα signals activate MeA neurons to stimulate physical activity, which in turn prevents body weight gain. Topics: Animals; Basic Helix-Loop-Helix Transcription Factors; Body Weight; Corticomedial Nuclear Complex; Energy Metabolism; Estrogen Receptor alpha; Estrogens; Female; Glucagon-Like Peptide 1; Male; Mice; Mice, Inbred C57BL; Mice, Knockout; Mice, Transgenic; Motor Activity; Neurons; Obesity; Repressor Proteins; Sex Characteristics; Signal Transduction; Weight Gain | 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 |
Another Agent for Obesity--Will This Time Be Different?
Topics: Female; Glucagon-Like Peptide 1; Humans; Hypoglycemic Agents; Male; Obesity | 2015 |
Farnesoid X receptor inhibits glucagon-like peptide-1 production by enteroendocrine L cells.
Bile acids are signalling molecules, which activate the transmembrane receptor TGR5 and the nuclear receptor FXR. BA sequestrants (BAS) complex bile acids in the intestinal lumen and decrease intestinal FXR activity. The BAS-BA complex also induces glucagon-like peptide-1 (GLP-1) production by L cells which potentiates β-cell glucose-induced insulin secretion. Whether FXR is expressed in L cells and controls GLP-1 production is unknown. Here, we show that FXR activation in L cells decreases proglucagon expression by interfering with the glucose-responsive factor Carbohydrate-Responsive Element Binding Protein (ChREBP) and GLP-1 secretion by inhibiting glycolysis. In vivo, FXR deficiency increases GLP-1 gene expression and secretion in response to glucose hence improving glucose metabolism. Moreover, treatment of ob/ob mice with the BAS colesevelam increases intestinal proglucagon gene expression and improves glycaemia in a FXR-dependent manner. These findings identify the FXR/GLP-1 pathway as a new mechanism of BA control of glucose metabolism and a pharmacological target for type 2 diabetes. Topics: Animals; Anticholesteremic Agents; Basic Helix-Loop-Helix Leucine Zipper Transcription Factors; Bile Acids and Salts; Blood Glucose; Colesevelam Hydrochloride; Colon; Diet, High-Fat; Enteroendocrine Cells; Glucagon-Like Peptide 1; Glycolysis; Humans; Ileum; Insulin; Insulin Secretion; Insulin-Secreting Cells; Intestinal Mucosa; Intestines; Jejunum; Mice; Mice, Knockout; Mice, Obese; Nuclear Proteins; Obesity; Proglucagon; Receptors, Cytoplasmic and Nuclear; Receptors, G-Protein-Coupled; RNA, Messenger; Sequestering Agents; Signal Transduction; Transcription Factors | 2015 |
Liraglutide improves weight loss in people who are overweight or obese, study shows.
Topics: Female; Glucagon-Like Peptide 1; Humans; Hypoglycemic Agents; Male; Obesity | 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 |
Selective FFA2 Agonism Appears to Act via Intestinal PYY to Reduce Transit and Food Intake but Does Not Improve Glucose Tolerance in Mouse Models.
Free fatty acid receptor 2 (FFA2) is expressed on enteroendocrine L cells that release glucagon-like peptide 1 (GLP-1) and peptide YY (PYY) when activated by short-chain fatty acids (SCFAs). Functionally GLP-1 and PYY inhibit gut transit, increase glucose tolerance, and suppress appetite; thus, FFA2 has therapeutic potential for type 2 diabetes and obesity. However, FFA2-selective agonists have not been characterized in vivo. Compound 1 (Cpd 1), a potent FFA2 agonist, was tested for its activity on the following: GLP-1 release, modulation of intestinal mucosal ion transport and transit in wild-type (WT) and FFA2(-/-) tissue, and food intake and glucose tolerance in lean and diet-induced obese (DIO) mice. Cpd 1 stimulated GLP-1 secretion in vivo, but this effect was only detected with dipeptidyl peptidase IV inhibition, while mucosal responses were PYY, not GLP-1, mediated. Gut transit was faster in FFA2(-/-) mice, while Cpd 1 slowed WT transit and reduced food intake and body weight in DIO mice. Cpd 1 decreased glucose tolerance and suppressed plasma insulin in lean and DIO mice, despite FFA2(-/-) mice displaying impaired glucose tolerance. These results suggest that FFA2 inhibits intestinal functions and suppresses food intake via PYY pathways, with limited GLP-1 contribution. Thus, FFA2 may be an effective therapeutic target for obesity but not for type 2 diabetes. Topics: Animals; Appetite; Cells, Cultured; Eating; Gastrointestinal Transit; Glucagon-Like Peptide 1; Glucose Intolerance; Intestinal Mucosa; Intestines; Mice; Mice, Obese; Obesity; Peptide YY; Receptors, Cell Surface | 2015 |
Obesity: Liraglutide--another weapon in the war against obesity?
Topics: Female; Glucagon-Like Peptide 1; Humans; Hypoglycemic Agents; Male; Obesity | 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 |
Dietary Whey and Casein Differentially Affect Energy Balance, Gut Hormones, Glucose Metabolism, and Taste Preference in Diet-Induced Obese Rats.
Dietary whey and casein proteins decrease food intake and body weight and improve glycemic control; however, little is known about the underlying mechanisms.. We determined the effects of dietary whey, casein, and a combination of the 2 on energy balance, hormones, glucose metabolism, and taste preference in rats.. In Expt. 1, Obesity Prone CD (OP-CD) rats were fed a high-fat control diet (33% fat energy) for 8 wk, and then randomly assigned to 4 isocaloric dietary treatments (n = 12/group): the control treatment (CO; 14% protein energy from egg white), the whey treatment (WH; 26% whey + 14% egg white), the casein treatment (CA; 26% casein + 14% egg white), or the whey plus casein treatment (WHCA; 13% whey + 13% casein + 14% egg white) for 28 d. Measurements included food intake, energy expenditure, body composition, metabolic hormones, glucose tolerance and key tissue markers of glucose and energy metabolism. In Expt. 2, naïve OP-CD rats were randomly assigned to 3 groups (n = 8/group). During an 8 d conditioning period, each group received on alternate days either the CO or WH, CO or CA, or CO or WHCA. Subsequently, preferences for the test diets were assessed on 2 consecutive days with food intake measurements at regular intervals.. In Expt. 1, food intake was decreased by 17-37% for the first 14 d in the WH and CA rats, and by 18-34% only for the first 4 d in the WHCA compared with the CO rats. Fat mass decreased by 21-28% for the WH rats and 17-33% for the CA rats from day 14 onward, but by 30% only on day 28 in WHCA rats, relative to CO rats. Thus, food intake, body weight, and fat mass decreased more rapidly in WH and CA rats than in WHCA rats. Energy expenditure in WH rats decreased for the first 4 d compared with CA and WHCA rats, and for the first 7 d compared with the CO rats. Circulating leptin, glucose-dependent insulinotropic polypeptide, interleukin 6, and glucose concentrations were lower in WH, CA, and WHCA rats than in CO rats. Plasma glucagon-like peptide 1 concentrations were greater in WH than in CA or WHCA rats. The improvements in glucose tolerance were greater in WH than in WHCA rats. The plasma membrane glucose transporter 4 (GLUT4)-to-total GLUT4 ratio in skeletal muscle was greater in CA and WHCA rats than in CO rats; other markers of glucose and energy metabolism in the adipose and cardiac tissues did not differ. In Expt. 2, during 4 conditioning trials, daily food intake was decreased in WH, CA, and WHCA rats by 26-37%, 30-43%, and 23-33%, respectively, compared with CO rats. Preferences for WH and CA rats were 45% and 31% lower, respectively, than those for CO rats, but that for WHCA rats did not differ.. Together, these data demonstrate that in obese rats, whey, casein, and their combination improve energy balance through differential effects on food intake, taste preference, energy expenditure, glucose tolerance, and gut hormone secretion. Topics: Adiposity; Animals; Blood Glucose; Caseins; Diet, Reducing; Energy Intake; Energy Metabolism; Food Preferences; Gastric Inhibitory Polypeptide; Glucagon-Like Peptide 1; Glucose Transporter Type 4; Interleukin-6; Leptin; Male; Muscle, Skeletal; Obesity; Protein Transport; Random Allocation; Rats, Inbred Strains; Whey | 2015 |
Chronic high-fat feeding increases GIP and GLP-1 secretion without altering body weight.
The incretin hormones, glucose-dependent insulinotropic polypeptide (GIP) and glucagon-like peptide-1 (GLP-1), enhance postprandial insulin secretion, promote adipogenesis, and regulate gastrointestinal motility and food intake. To date, a consensus on how the incretin response is altered in obesity is lacking. We investigated the effects of chronic high-fat (HF) feeding on incretin secretion in the lymph fistula rat model. Male Sprague-Dawley rats (8 wk) were provided a semipurified AIN93M HF or low-fat (LF) diet ad libitum for 3 or 13 wk; a HF pair-fed (HF-PF) group was included as a control during the 3-wk feeding trial. Energy intake, body weight, and body composition were regularly monitored. At the culmination of the feeding period, an intestinal lymphatic duct cannula and duodenal infusion tube were installed. All animals were challenged with a 3-ml Ensure bolus (3.125 kcal/animal) to measure lymphatic incretin secretion. Despite a significantly higher energy intake, both the 3-wk and 13-wk HF-fed animals did not have an increase in body weight and only a slight increase in body fat compared with LF-fed rats. Following the duodenal Ensure challenge, the 3-wk and 13-wk HF-fed rats had significantly greater lymphatic GIP and GLP-1 secretion than the LF-fed animals. Additionally, the HF-PF group displayed a secretion profile similar to the HF-fed animals for GIP but a similar pattern to the LF-fed animals for GLP-1. The HF-PF data suggest that the increased GIP secretion is driven by the greater percentage of fat intake, whereas the increased GLP-1 secretion is driven by the excess caloric intake. Topics: Adipogenesis; Animals; Body Composition; Body Weight; Diet, High-Fat; Dietary Fats; Disease Models, Animal; Gastric Inhibitory Polypeptide; Gastrointestinal Motility; Glucagon-Like Peptide 1; Incretins; Insulin; Insulin Secretion; Male; Obesity; Postprandial Period; Rats; Rats, Sprague-Dawley | 2015 |
Letter to the Editor: Liraglutide-Induced Increase in Bone Formation Can Be Dependent on Osteocalcin.
Topics: Bone Resorption; Female; Glucagon-Like Peptide 1; Humans; Obesity; Osteogenesis; Receptors, Glucagon; Weight Loss | 2015 |
Response to the Letter by Kizilgul M., et al.
Topics: Bone Resorption; Female; Glucagon-Like Peptide 1; Humans; Obesity; Osteogenesis; Receptors, Glucagon; Weight Loss | 2015 |
[Liraglutid can support weight loss].
Topics: Female; Glucagon-Like Peptide 1; Humans; Hypoglycemic Agents; Male; Obesity | 2015 |
Mice Deficient in Proglucagon-Derived Peptides Exhibit Glucose Intolerance on a High-Fat Diet but Are Resistant to Obesity.
Homozygous glucagon-GFP knock-in mice (Gcggfp/gfp) lack proglucagon derived-peptides including glucagon and GLP-1, and are normoglycemic. We have previously shown that Gcggfp/gfp show improved glucose tolerance with enhanced insulin secretion. Here, we studied glucose and energy metabolism in Gcggfp/gfp mice fed a high-fat diet (HFD). Male Gcggfp/gfp and Gcggfp/+ mice were fed either a normal chow diet (NCD) or an HFD for 15-20 weeks. Regardless of the genotype, mice on an HFD showed glucose intolerance, and Gcggfp/gfp mice on HFD exhibited impaired insulin secretion whereas Gcggfp/+ mice on HFD exhibited increased insulin secretion. A compensatory increase in β-cell mass was observed in Gcggfp/+mice on HFD, but not in Gcggfp/gfp mice on the same diet. Weight gain was significantly lower in Gcggfp/gfp mice than in Gcggfp/+mice. Oxygen consumption was enhanced in Gcggfp/gfp mice compared to Gcggfp/+ mice on an HFD. HFD feeding significantly increased uncoupling protein 1 mRNA expression in brown adipose and inguinal white adipose tissues of Gcggfp/gfp mice, but not of Gcggfp/+mice. Treatment with the glucagon-like peptide-1 receptor agonist liraglutide (200 mg/kg) improved glucose tolerance in Gcggfp/gfp mice and insulin content in Gcggfp/gfp and Gcggfp/+ mice was similar after liraglutide treatment. Our findings demonstrate that Gcggfp/gfp mice develop diabetes upon HFD-feeding in the absence of proglucagon-derived peptides, although they are resistant to diet-induced obesity. Topics: Animals; Diet, High-Fat; Glucagon-Like Peptide 1; Glucose; Glucose Intolerance; Glucose Tolerance Test; Insulin; Insulin Resistance; Insulin-Secreting Cells; Male; Mice; Mice, Inbred C57BL; Obesity; Peptides; Proglucagon; Weight Gain | 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 |
Subcutaneous liraglutide reduces weight and improves metabolic control in obese participants.
Topics: Female; Glucagon-Like Peptide 1; Humans; Hypoglycemic Agents; Male; Obesity | 2015 |
Sardine protein diet increases plasma glucagon-like peptide-1 levels and prevents tissue oxidative stress in rats fed a high-fructose diet.
The current study investigated whether sardine protein mitigates the adverse effects of fructose on plasma glucagon‑like peptide-1 (GLP-1) and oxidative stress in rats. Rats were fed casein (C) or sardine protein (S) with or without high‑fructose (HF) for 2 months. Plasma glucose, insulin, GLP‑1, lipid and protein oxidation and antioxidant enzymes were assayed. HF rats developed obesity, hyperglycemia, hyperinsulinemia, insulin resistance and oxidative stress despite reduced energy and food intakes. High plasma creatinine and uric acid levels, in addition to albuminuria were observed in the HF groups. The S‑HF diet reduced plasma glucose, insulin, creatinine, uric acid and homeostasis model assessment‑insulin resistance index levels, however increased GLP‑1 levels compared with the C‑HF diet. Hydroperoxides were reduced in the liver, kidney, heart and muscle of S‑HF fed rats compared with C‑HF fed rats. A reduction in liver, kidney and heart carbonyls was observed in S‑HF fed rats compared with C‑HF fed rats. Reduced levels of nitric oxide (NO) were detected in the liver, kidney and heart of the S‑HF fed rats compared with C‑HF fed rats. The S diet compared with the C diet reduced levels of liver hydroperoxides, heart carbonyls and kidney NO. The S‑HF diet compared with the C‑HF diet increased the levels of liver and kidney superoxide dismutase, liver and muscle catalase, liver, heart and muscle glutathione peroxidase and liver ascorbic acid. The S diet prevented and reversed insulin resistance and oxidative stress, and may have benefits in patients with metabolic syndrome. Topics: alpha-Tocopherol; Animals; Ascorbic Acid; Blood Glucose; Caseins; Catalase; Diet; Energy Intake; Fish Proteins; Fructose; Glucagon-Like Peptide 1; Hydrogen Peroxide; Kidney; Liver; Male; Nitric Oxide; Obesity; Oxidative Stress; Rats; Rats, Wistar; Superoxide Dismutase | 2015 |
[Liraglutide for weight loss in overweight and obese adults].
Topics: Female; Glucagon-Like Peptide 1; Humans; Hypoglycemic Agents; Male; Obesity | 2015 |
Letter to the Editor: "GLP-1 Receptor Agonist Treatment Increases Bone Formation and Prevents Bone Loss in Weight-Reduced Obese Women" by Iepsen E.W., et al.
Topics: Bone Resorption; Female; Glucagon-Like Peptide 1; Humans; Obesity; Osteogenesis; Receptors, Glucagon; Weight Loss | 2015 |
Response to the Letter by Napoli N., et al.
Topics: Bone Resorption; Female; Glucagon-Like Peptide 1; Humans; Obesity; Osteogenesis; Receptors, Glucagon; Weight Loss | 2015 |
Liraglutide in Weight Management.
Topics: Female; Glucagon-Like Peptide 1; Humans; Hypoglycemic Agents; Male; Obesity | 2015 |
Liraglutide in Weight Management.
Topics: Female; Glucagon-Like Peptide 1; Humans; Hypoglycemic Agents; Male; Obesity | 2015 |
Liraglutide in Weight Management.
Topics: Female; Glucagon-Like Peptide 1; Humans; Hypoglycemic Agents; Male; Obesity | 2015 |
Liraglutide in Weight Management.
Topics: Female; Glucagon-Like Peptide 1; Humans; Hypoglycemic Agents; Male; Obesity | 2015 |
Liraglutide in Weight Management.
Topics: Female; Glucagon-Like Peptide 1; Humans; Hypoglycemic Agents; Male; Obesity | 2015 |
Liraglutide in Weight Management.
Topics: Female; Glucagon-Like Peptide 1; Humans; Hypoglycemic Agents; Male; Obesity | 2015 |
Liraglutide in Weight Management.
Topics: Female; Glucagon-Like Peptide 1; Humans; Hypoglycemic Agents; Male; Obesity | 2015 |
Impaired GLP-1 signaling contributes to reduced sensitivity to duodenal nutrients in obesity-prone rats during high-fat feeding.
Increased consumption of a high-fat (HF) diet is a salient contributor to obesity; however, how diminished satiation signaling contributes to overconsumption and obesity development remains poorly understood.. Using obese-prone (OP) and obese-resistant (OR) rats, we tested feeding responses to intragastric liquid meal replacement, prior and after HF feeding. Next, chow- and HF-fed OP and OR rats were tested for sensitivity to intraduodenal glucose, intralipid, and meal replacement loads. To examine the role of glucagon-like peptide-1 (GLP-1) and vagal signaling, animals were treated with exendin-9, GLP-1 receptor antagonist, prior to meal replacement infusion, and Fos-like immunoreactivity (Fos-Li) in the dorsal hindbrain was examined after infusion.. OP and OR rats reduced chow intake equally following gastric liquid meal; however, after 2 weeks of HF feeding, intragastric meal replacement reduced food intake less in OP than OR. Similarly, HF feeding, but not chow, diminished the suppressive effects of intraduodenal meal replacement, glucose, and intralipid in OP compared to OR. This effect was associated with lower Fos-Li expression in the dorsal hindbrain of OP rats. Finally, exendin-9 failed to attenuate reduction of food intake by meal replacement in OP rats during HF feeding.. Susceptibility to obesity coupled with HF feeding results in rapid impairments in nutrient-induced satiation through blunted responses in endogenous GLP-1 and hindbrain vagal afferent signaling. Topics: Animals; Diet, High-Fat; Dietary Fats; Disease Susceptibility; Duodenum; Eating; Glucagon-Like Peptide 1; Male; Obesity; Rats; Satiation; Signal Transduction | 2015 |
Time course of cardiometabolic alterations in a high fat high sucrose diet mice model and improvement after GLP-1 analog treatment using multimodal cardiovascular magnetic resonance.
Cardiovascular complications of obesity and diabetes are major health problems. Assessing their development, their link with ectopic fat deposition and their flexibility with therapeutic intervention is essential. The aim of this study was to longitudinally investigate cardiac alterations and ectopic fat accumulation associated with diet-induced obesity using multimodal cardiovascular magnetic resonance (CMR) in mice. The second objective was to monitor cardiac response to exendin-4 (GLP-1 receptor agonist).. Male C57BL6R mice subjected to a high fat (35 %) high sucrose (34 %) (HFHSD) or a standard diet (SD) during 4 months were explored every month with multimodal CMR to determine hepatic and myocardial triglyceride content (HTGC, MTGC) using proton MR spectroscopy, cardiac function with cine cardiac MR (CMR) and myocardial perfusion with arterial spin labeling CMR. Furthermore, mice treated with exendin-4 (30 μg/kg SC BID) after 4 months of diet were explored before and 14 days post-treatment with multimodal CMR.. HFHSD mice became significantly heavier (+33 %) and displayed glucose homeostasis impairment (1-month) as compared to SD mice, and developed early increase in HTGC (1 month, +59 %) and MTGC (2-month, +63 %). After 3 months, HFHSD mice developed cardiac dysfunction with significantly higher diastolic septum wall thickness (sWtnD) (1.28 ± 0.03 mm vs. 1.12 ± 0.03 mm) and lower cardiac index (0.45 ± 0.06 mL/min/g vs. 0.68 ± 0.07 mL/min/g, p = 0.02) compared to SD mice. A significantly lower cardiac perfusion was also observed (4 months:7.5 ± 0.8 mL/g/min vs. 10.0 ± 0.7 mL/g/min, p = 0.03). Cardiac function at 4 months was negatively correlated to both HTGC and MTGC (p < 0.05). 14-day treatment with Exendin-4 (Ex-4) dramatically reversed all these alterations in comparison with placebo-treated HFHSD. Ex-4 diminished myocardial triglyceride content (-57.8 ± 4.1 %), improved cardiac index (+38.9 ± 10.9 %) and restored myocardial perfusion (+52.8 ± 16.4 %) under isoflurane anesthesia. Interestingly, increased wall thickness and hepatic steatosis reductions were independent of weight loss and glycemia decrease in multivariate analysis (p < 0.05).. CMR longitudinal follow-up of cardiac consequences of obesity and diabetes showed early accumulation of ectopic fat in mice before the occurrence of microvascular and contractile dysfunction. This study also supports a cardioprotective effect of glucagon-like peptide-1 receptor agonist. Topics: Adiposity; Animals; Blood Glucose; Coronary Circulation; Diabetes Mellitus; Diet, High-Fat; Dietary Sucrose; Disease Models, Animal; Exenatide; Fatty Liver; Glucagon-Like Peptide 1; Heart Diseases; Liver; Magnetic Resonance Imaging, Cine; Male; Mice, Inbred C57BL; Multimodal Imaging; Multivariate Analysis; Myocardial Contraction; Myocardial Perfusion Imaging; Myocardium; Obesity; Peptides; Predictive Value of Tests; Proton Magnetic Resonance Spectroscopy; Recovery of Function; Time Factors; Triglycerides; Venoms; Ventricular Function; Weight Gain | 2015 |
CCK Response Deficiency in Synphilin-1 Transgenic Mice.
Previously, we have identified a novel role for the cytoplasmic protein, synphilin-1(SP1), in the controls of food intake and body weight in both mice and Drosophila. Ubiquitous overexpression of human SP1 in brain neurons in transgenic mice results in hyperphagia expressed as an increase in meal size. However, the mechanisms underlying this action of SP1 remain to be determined. Here we investigate a potential role for altered gut feedback signaling in the effects of SP1 on food intake. We examined responses to peripheral administration of cholecytokinin (CCK), amylin, and the glucagon like peptide-1 (GLP-1) receptor agonist, exendin-4. Intraperitoneal administration of CCK at doses ranging from 1-10 nmol/kg significantly reduced glucose intake in wild type (WT) mice, but failed to affect intake in SP1 transgenic mice. Moreover, there was a significant attenuation of CCK-induced c-Fos expression in the dorsal vagal complex in SP1 transgenic mice. In contrast, WT and SP1 transgenic mice were similarly responsive to both amylin and exendin-4 treatment. These studies demonstrate that SP1 results in a CCK response deficiency that may contribute to the increased meal size and overall hyperphagia in synphillin-1 transgenic mice. Topics: Animals; Body Weight; Brain; Carrier Proteins; Cholecystokinin; Cytoplasm; Eating; Exenatide; Feeding Behavior; Female; Gene Expression Regulation; Genotype; Glucagon-Like Peptide 1; Glucagon-Like Peptide-1 Receptor; Humans; Hyperphagia; Infusions, Parenteral; Intestinal Mucosa; Intracellular Signaling Peptides and Proteins; Islet Amyloid Polypeptide; Male; Mice; Mice, Inbred C57BL; Mice, Transgenic; Nerve Tissue Proteins; Neurons; Obesity; Peptides; Proto-Oncogene Proteins c-fos; Signal Transduction; Venoms | 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 |
The Gustatory Signaling Pathway and Bitter Taste Receptors Affect the Development of Obesity and Adipocyte Metabolism in Mice.
Intestinal chemosensory signaling pathways involving the gustatory G-protein, gustducin, and bitter taste receptors (TAS2R) have been implicated in gut hormone release. Alterations in gut hormone profiles may contribute to the success of bariatric surgery. This study investigated the involvement of the gustatory signaling pathway in the development of diet-induced obesity and the therapeutic potential of targeting TAS2Rs to induce body weight loss. α-gustducin-deficient (α-gust-/-) mice became less obese than wild type (WT) mice when fed a high-fat diet (HFD). White adipose tissue (WAT) mass was lower in α-gust-/- mice due to increased heat production as a result of increases in brown adipose tissue (BAT) thermogenic activity, involving increased protein expression of uncoupling protein 1. Intra-gastric treatment of obese WT and α-gust-/- mice with the bitter agonists denatonium benzoate (DB) or quinine (Q) during 4 weeks resulted in an α-gustducin-dependent decrease in body weight gain associated with a decrease in food intake (DB), but not involving major changes in gut peptide release. Both WAT and 3T3-F442A pre-adipocytes express TAS2Rs. Treatment of pre-adipocytes with DB or Q decreased differentiation into mature adipocytes. In conclusion, interfering with the gustatory signaling pathway protects against the development of HFD-induced obesity presumably through promoting BAT activity. Intra-gastric bitter treatment inhibits weight gain, possibly by directly affecting adipocyte metabolism. Topics: Adipocytes; Adipose Tissue, Brown; Adipose Tissue, White; Animals; Body Weight; Cell Differentiation; Diet, High-Fat; Glucagon-Like Peptide 1; Heterotrimeric GTP-Binding Proteins; Ion Channels; Mice, Inbred C57BL; Mice, Mutant Strains; Mitochondrial Proteins; Obesity; Quaternary Ammonium Compounds; Quinine; Receptors, G-Protein-Coupled; Signal Transduction; Taste; Thermogenesis; Uncoupling Protein 1 | 2015 |
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 |
Resistant starch from high amylose maize (HAM-RS2) and dietary butyrate reduce abdominal fat by a different apparent mechanism.
Obesity is a health concern. Resistant starch (RS) type 2 from high-amylose maize (HAM-RS2) and dietary sodium butyrate (SB) reduce abdominal fat in rodents. RS treatment is associated with increased gut hormones peptide YY (PYY) and glucagon-like peptide 1 (GLP-1), but it is not known if SB increases these hormones.. This was investigated in a 2 × 2 rat study with HAM-RS2 (0 or 28% weight) and dietary sodium butyrate (0 and 3.2%) resulting in isocaloric treatments: energy control (EC), sodium butyrate (SB), HAM-RS2 (RS), and the combination (SBRS).. RS and SB reduced abdominal fat and the combination reduced abdominal fat compared to SB and RS. RS was associated with increased fermentation in the cecum. Serum PYY and GLP-1 total were increased with RS treatment. RS treatment was associated with increased cecal butyrate produced from fermentation of RS, but there was no cecal increase for dietary SB.. SB after its absorption into the blood appears to not affect production of PYY and GLP-1, while butyrate from fermentation in the cecum promotes increased PYY and GLP-1. Future studies with lower doses of RS and SB are warranted and the combination may be beneficial for human health. Topics: Abdominal Fat; Adiposity; Amylose; Animals; Anti-Obesity Agents; Bifidobacterium; Butyric Acid; Cecum; Fermentation; Glucagon-Like Peptide 1; Intestinal Mucosa; Lactobacillales; Male; Obesity; Peptide YY; Plant Proteins; Plants, Genetically Modified; Prebiotics; Rats; Rats, Sprague-Dawley; Seeds; Starch; Zea mays | 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 |
Incretin response to a standard test meal in a rat model of sleeve gastrectomy with diet-induced obesity.
Currently, the most effective treatment for obesity is bariatric surgery. Gastroduodenal bypass surgery produces sustained weight loss and improves glycemic control and insulin sensitivity. Previous studies have shown that sleeve gastrectomy (SG) produces similar results and implicate changes in incretin hormone release in these effects.. Male Sprague-Dawley rats were divided into four groups; lean control (lean), diet-induced obesity (DIO), DIO animals that had undergone SG (SG), and DIO animals that had undergone a sham operation (sham).. After a 2-week recovery period, the incretin response to a standard test meal was measured. Blood sampling was performed in free-moving rats at various time points using chronic vascular access to the right jugular vein. There was a significant increase in the bodyweight of DIO animals fed a high-fat/high-sugar diet compared with the lean animals, which was reversed by SG. DIO caused an impairment of the GLP-1 response to a standard test meal, but not the GIP response. SG resulted in a dramatic increase in the GLP-1 response to a standard test meal but had no effect on the GIP response.. A rapid rise in blood sugar was observed in the SG group following a standard test meal that was followed by reactive hypoglycemia. SG dramatically increases the GLP-1 response to a standard test meal but has no effect on GIP in a rat model of DIO. Topics: Animals; Blood Glucose; Diet; Disease Models, Animal; Gastrectomy; Glucagon-Like Peptide 1; Incretins; Male; Obesity; Rats; Rats, Sprague-Dawley | 2014 |
Obese patients after gastric bypass surgery have lower brain-hedonic responses to food than after gastric banding.
Roux-en-Y gastric bypass (RYGB) has greater efficacy for weight loss in obese patients than gastric banding (BAND) surgery. We hypothesise that this may result from different effects on food hedonics via physiological changes secondary to distinct gut anatomy manipulations.. We used functional MRI, eating behaviour and hormonal phenotyping to compare body mass index (BMI)-matched unoperated controls and patients after RYGB and BAND surgery for obesity.. Obese patients after RYGB had lower brain-hedonic responses to food than patients after BAND surgery. RYGB patients had lower activation than BAND patients in brain reward systems, particularly to high-calorie foods, including the orbitofrontal cortex, amygdala, caudate nucleus, nucleus accumbens and hippocampus. This was associated with lower palatability and appeal of high-calorie foods and healthier eating behaviour, including less fat intake, in RYGB compared with BAND patients and/or BMI-matched unoperated controls. These differences were not explicable by differences in hunger or psychological traits between the surgical groups, but anorexigenic plasma gut hormones (GLP-1 and PYY), plasma bile acids and symptoms of dumping syndrome were increased in RYGB patients.. The identification of these differences in food hedonic responses as a result of altered gut anatomy/physiology provides a novel explanation for the more favourable long-term weight loss seen after RYGB than after BAND surgery, highlighting the importance of the gut-brain axis in the control of reward-based eating behaviour. Topics: Adult; Appetite Regulation; Bile Acids and Salts; Body Mass Index; Brain; Diet Records; Dumping Syndrome; Feeding Behavior; Female; Food; Gastric Bypass; Gastroplasty; Glucagon-Like Peptide 1; Humans; Magnetic Resonance Imaging; Male; Middle Aged; Obesity; Peptide YY; Pleasure; Young Adult | 2014 |
GLP-1 responses are heritable and blunted in acquired obesity with high liver fat and insulin resistance.
OBJECTIVE Impaired incretin response represents an early and uniform defect in type 2 diabetes, but the contributions of genes and the environment are poorly characterized. RESEARCH DESIGN AND METHODS We studied 35 monozygotic (MZ) and 75 dizygotic (DZ) twin pairs (discordant and concordant for obesity) to determine the heritability of glucagon-like peptide 1 (GLP-1) responses to an oral glucose tolerance test (OGTT) and the influence of acquired obesity to GLP-1, glucose-dependent insulinotropic peptide (GIP), and peptide YY (PYY) during OGTT or meal test. RESULTS The heritability of GLP-1 area under the curve was 67% (95% CI 45-80). Cotwins from weight-concordant MZ and DZ pairs and weight-discordant MZ pairs but concordant for liver fat content demonstrated similar glucose, insulin, and incretin profiles after the OGTT and meal tests. In contrast, higher insulin responses and blunted 60-min GLP-1 responses during the OGTT were observed in the heavier as compared with leaner MZ cotwins discordant for BMI, liver fat, and insulin sensitivity. Blunted GLP-1 response to OGTT was observed in heavier as compared with leaner DZ cotwins discordant for obesity and insulin sensitivity. CONCLUSIONS Whereas the GLP-1 response to the OGTT is heritable, an acquired unhealthy pattern of obesity characterized by liver fat accumulation and insulin resistance is closely related to impaired GLP-1 response in young adults. Topics: Adult; Blood Glucose; Body Weight; Female; Gastric Inhibitory Polypeptide; Glucagon-Like Peptide 1; Glucose Tolerance Test; Humans; Incretins; Insulin; Insulin Resistance; Lipid Metabolism; Liver; Male; Obesity; Peptide Fragments | 2014 |
Systematic ileal transposition in Zucker rats shows advantage for long segment distal transposition.
The possibility of achieving diabetes remission through bariatric surgery has dramatically changed treatment options for this disease. Ileal transposition (IT), specifically designed to provoke diabetes remission, has so far shown great success in rodent studies. However, it remains uncertain which combination of ileal length and origin produces best results.. Forty male Zucker rats underwent transposition of 25% distal, 50% distal, and 50% proximal ileum or sham surgery. Glucose control, insulin, and glucagon-like peptide (GLP)-1 serum levels were analyzed after 1, 3, and 6 months. Body weight was recorded weekly.. In relation to sham-operated animals, the 50% distal IT presented with improved glucose tolerance after 1, 3, and 6 months (2-way analysis of variance [ANOVA]: P < .05, < .0001, and < .0001, respectively). The 25% distal and 50% proximal IT only showed improved glucose control after 3 months, suggesting a fading effect in long-term observation (2-way ANOVA: P < .0001 for both). Glucose-stimulated GLP-1 levels were steadily elevated only in the 2 distal IT groups (Mann-Whitney sham versus 50% distal, P < .01, < .01, and < .05; sham versus 25% distal, P < .01, = .001, < .05 for 1, 3, and 6 months, respectively). IT had no impact on serum insulin levels.. The current study restates the findings of improved glucose tolerance and GLP-1 stimulation after IT, but is the first to demonstrate a fading glycemic effect in long-term observation. Systematic comparison of length and ileal origin revealed that long and distal transposition delivers best results. Topics: Animals; Bariatric Surgery; Body Weight; Diabetes Mellitus, Experimental; Digestive System Surgical Procedures; Glucagon-Like Peptide 1; Glucose Tolerance Test; Ileum; Male; Obesity; Rats; Rats, Zucker | 2014 |
Duodenal nutrient exclusion improves metabolic syndrome and stimulates villus hyperplasia.
Surgical interventions that prevent nutrient exposure to the duodenum are among the most successful treatments for obesity and diabetes. However, these interventions are highly invasive, irreversible and often carry significant risk. The duodenal-endoluminal sleeve (DES) is a flexible tube that acts as a barrier to nutrient-tissue interaction along the duodenum. We implanted this device in Zucker Diabetic Fatty (ZDF) rats to gain greater understanding of duodenal nutrient exclusion on glucose homeostasis.. ZDF rats were randomised to four groups: Naive, sham ad libitum, sham pair-fed, and DES implanted. Food intake, body weight (BW) and body composition were measured for 28 days postoperatively. Glucose, lipid and bile acid metabolism were evaluated, as well as histological assessment of the upper intestine.. DES implantation induced a sustained decrease in BW throughout the study that was matched by pair-fed sham animals. Decreased BW resulted from loss of fat, but not lean mass. DES rats were also found to be more glucose tolerant than either ad libitum-fed or pair-fed sham controls, suggesting fat mass independent metabolic benefits. DES also reduced circulating triglyceride and glycerol levels while increasing circulating bile acids. Interestingly, DES stimulated a considerable increase in villus length throughout the upper intestine, which may contribute to metabolic improvements.. Our preclinical results validate DES as a promising therapeutic approach to diabetes and obesity, which offers reversibility, low risk, low invasiveness and triple benefits including fat mass loss, glucose and lipid metabolism improvement which mechanistically may involve increased villus growth in the upper gut. Topics: Animals; Bile Acids and Salts; Blood Glucose; Body Composition; Body Weight; Diabetes Mellitus, Experimental; Duodenum; Glucagon-Like Peptide 1; Glucose Tolerance Test; Glycerol; Homeostasis; Ileum; Intestinal Absorption; Jejunum; Male; Metabolic Syndrome; Obesity; Prostheses and Implants; Random Allocation; Rats; Rats, Zucker; Triglycerides | 2014 |
Combined effects of oligofructose and Bifidobacterium animalis on gut microbiota and glycemia in obese rats.
Prebiotics and probiotics may be able to modify an obesity-associated gut microbiota. The aim of this study was to examine the individual and combined effects of the prebiotic oligofructose (OFS) and the probiotic Bifidobacterium animalis subsp. lactis BB-12 (BB-12) on gut microbiota and host metabolism in obese rats.. Adult male, diet-induced obese Sprague Dawley rats were randomized to: (1) Control (C); (2) 10% OFS; (3) BB-12; (4) OFS + BB-12 for 8 weeks (n = 9-10 rats/group). Body composition, glycemia, gut permeability, satiety hormones, cytokines, and gut microbiota were examined.. Prebiotic, but not probiotic reduced energy intake, weight gain, and fat mass (P < 0.01). OFS, BB-12, and the combined OFS + BB-12 improved glycemia (P < 0.05). Individually, OFS and BB-12 reduced insulin levels (P < 0.05). Portal GLP-1 was increased with OFS, whereas probiotic increased GLP-2 (P < 0.05). There was a marked increase in bifidobacteria and lactobacilli (P < 0.01) with OFS that was not observed with probiotic alone.. The impact of prebiotic intake on body composition and gut microbiota was of greater magnitude than the probiotic BB-12. Despite this, an improvement in glucose AUC with both prebiotic or probiotic demonstrates the beneficial role of each of these "biotic" agents in glycemic control. Topics: Animals; Bifidobacterium; Blood Glucose; Body Composition; Diet; Energy Intake; Gastrointestinal Tract; Glucagon-Like Peptide 1; Glucagon-Like Peptide 2; Insulin; Lactobacillaceae; Male; Microbiota; Obesity; Oligosaccharides; Prebiotics; Rats; Rats, Sprague-Dawley | 2014 |
Glucagon-like peptide-1 analogue, liraglutide, improves liver fibrosis markers in obese women with polycystic ovary syndrome and nonalcoholic fatty liver disease.
Nonalcoholic fatty liver disease (NAFLD) has been linked to polycystic ovary syndrome (PCOS) and carries an increased risk of liver cirrhosis. Procollagen type 3 amino-terminal peptide (PIIINP) is an independent predictor of liver cirrhosis.. To assess whether 6-month treatment with GLP-1 analogue, liraglutide, improves markers of liver fibrosis.. A case-control study comparing women with PCOS to age- and weight-matched controls. PCOS was diagnosed according to the Rotterdam criteria. All participants underwent liver function tests and liver ultrasound scan to assess for fatty infiltration. Serum marker for liver fibrosis, PIIINP, was measured at baseline and after 6-month treatment with liraglutide 1·8 mg od.. Nineteen women with PCOS and 17 controls were recruited, age 32·8 ± 7·2 vs 33·5 ± 6·7 years and weight 100·9 ± 16·7 vs 99·3 ± 14·7 kg, respectively. At baseline, the PCOS group had higher testosterone 1·2 ± 0·3 vs 0·9 ± 0·3 nm (P = 0·01), HOMA-IR 5·1 ± 2·6 vs 3·5 ± 1·3 (P = 0·03), AST 22·4 ± 5·2 vs 18·8 ± 3·4 u/l (P = 0·04), PIIINP 4·4 ± 0·8 vs 3·5 ± 0·8 ug/ml (P = 0·01) and NAFLD seven (35%) vs none (P = 0·005), respectively. Twenty-five (69%) participants completed the study (13 PCOS, 12 controls). Following treatment, weight was reduced by 3·0 ± 4·2 kg (P = 0·01) and 3·8 ± 3·4 kg (P = 0·001), respectively. Similarly, HOMA-IR, hsCRP, triglycerides and urinary isoprostane significantly reduced in both groups. PIIINP significantly reduced the in PCOS group 4·4 ± 0·8 vs 3·7 ± 0·9 ug/ml (P < 0·01), but not in controls 3·5 ± 0·8 vs 3·2 ± 0·7 ug/ml (P = 0·08).. Treatment with liraglutide, and/or associated weight loss, significantly reduced PIIINP levels in obese women with PCOS. This may be an additional beneficial factor when considering the use of liraglutide in women with PCOS, obesity and NAFLD. Topics: Adult; Case-Control Studies; Female; Glucagon-Like Peptide 1; Humans; Liraglutide; Liver Cirrhosis; Non-alcoholic Fatty Liver Disease; Obesity; Polycystic Ovary Syndrome; Triglycerides | 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 |
Intraduodenal milk protein concentrate augments the glycemic and food intake suppressive effects of DPP-IV inhibition.
Glucagon-like peptide-1 (GLP-1) is an incretin hormone released from intestinal L-cells in response to food entering into the gastrointestinal tract. GLP-1-based pharmaceuticals improve blood glucose regulation and may hold promise for obesity treatment, as GLP-1 drugs reduce food intake and body weight in humans and animals. In an effort to improve GLP-1 pharmacotherapies, we focused our attention on macronutrients that, when present in the gastrointestinal tract, may enhance GLP-1 secretion and improve glycemic regulation and food intake suppression when combined with systemic administration of sitagliptin, a pharmacological inhibitor of DPP-IV (enzyme responsible for GLP-1 degradation). In particular, previous data suggest that specific macronutrient constituents found in dairy foods may act as potent secretagogues for GLP-1 and therefore may potentially serve as an adjunct dietary therapy in combination with sitagliptin. To directly test this hypothesis, rats received intraperitoneal injections of sitagliptin (6 mg/kg) or saline vehicle followed by intraduodenal infusions of either milk protein concentrate (MPC; 80/20% casein/whey; 4 kcal), soy protein (nondairy control infusate; 4 kcal), or 0.9% NaCl. Food intake was assessed 30 min postinfusion. In separate studies, regulation of blood glucose was examined via a 2-h oral glucose tolerance test (2 g/kg) following identical sitagliptin treatment and intraduodenal nutrient infusions. Collectively, results show that intraduodenal MPC, but not soy protein, significantly enhances both the food intake suppression and improved control of blood glucose produced by sitagliptin. These data support the hypothesis that dietary intake of dairy protein may be beneficial as an adjunct behavioral therapy to enhance the glycemic and food intake suppressive effects of GLP-1-based pharmacotherapies. Topics: Animals; Blood Glucose; Dipeptidyl Peptidase 4; Eating; Glucagon-Like Peptide 1; Hypoglycemic Agents; Male; Milk Proteins; Obesity; Pyrazines; Rats; Rats, Sprague-Dawley; Sitagliptin Phosphate; Triazoles | 2014 |
APOE*3Leiden.CETP transgenic mice as model for pharmaceutical treatment of the metabolic syndrome.
This study aimed to investigate systematically (i) the appropriate dietary conditions to induce the features of the MetS in APOE*3Leiden.humanCholesteryl Ester Transfer Protein (E3L.CETP) mice and (ii) whether the response of this model to different antidiabetic and hypolipidemic drugs is similar as in humans.. Male obese, IR and dyslipidemic E3L.CETP mice were treated with antidiabetic drugs rosiglitazone, liraglutide or an experimental 11β-hydroxysteroid-dehydrogenase-1 (HSD-1) inhibitor, or with hypolipidemic drugs atorvastatin, fenofibrate or niacin for 4-6 weeks. The effects on bw, IR and plasma and liver lipids were assessed.. Rosiglitazone, liraglutide and HSD-1 inhibitor significantly decreased glucose and insulin levels or IR. Liraglutide and HSD-1 inhibitor also decreased bw. Atorvastatin, fenofibrate and niacin improved the dyslipidemia and fenofibrate and niacin increased high-density lipoprotein (HDL) cholesterol. In addition, hepatic triglycerides were significantly decreased by treatment with rosiglitazone and liraglutide, while hepatic cholesterol esters were significantly decreased by rosiglitazone and atorvastatin.. We conclude that the E3L.CETP mouse is a promising novel translational model to investigate the effects of new drugs, alone or in combination, that affect IR, diabetic dyslipidemia and non-alcoholic fatty liver disease (NAFLD). Topics: 11-beta-Hydroxysteroid Dehydrogenase Type 1; Animals; Apolipoprotein E3; Atorvastatin; Cholesterol Ester Transfer Proteins; Disease Models, Animal; Fenofibrate; Glucagon-Like Peptide 1; Heptanoic Acids; Humans; Hypoglycemic Agents; Hypolipidemic Agents; Liraglutide; Male; Metabolic Syndrome; Mice, Transgenic; Niacin; Non-alcoholic Fatty Liver Disease; Obesity; Pyrroles; Rosiglitazone; Thiazolidinediones | 2014 |
GLP-1/glucagon coagonism restores leptin responsiveness in obese mice chronically maintained on an obesogenic diet.
We recently reported restoration of leptin responsiveness in diet-induced obese (DIO) mice using a pharmacologically optimized, polyethylene-glycolated (PEG)-leptin analog in combination with exendin-4 or FGF21. However, the return of leptin action required discontinuation of high-fat diet (HFD) exposure. Here we assess whether a single peptide possessing balanced coagonism at the glucagon-like peptide 1 (GLP-1) and glucagon receptors can restore leptin responsiveness in DIO mice maintained on a HFD. DIO mice were treated with PEG-GLP-1/glucagon (30 nmol/kg every fourth day) to induce an ∼15% body weight loss, upon which they were randomized to continue PEG-GLP-1/glucagon therapy or reassigned to receive supplemental daily PEG-leptin (185 nmol/kg/day). The addition of PEG-leptin to PEG-GLP-1/glucagon resulted in an ∼18% greater weight loss as compared with PEG-GLP-1/glucagon alone and was accompanied by further decreases in food intake and improved glucose and lipid metabolism. The beneficial effect of PEG-leptin supplementation occurred after an initial body weight loss similar to what we previously reported following reduced dietary fat along with PEG-leptin and exendin-4 or FGF21 cotreatment. In summary, we report that GLP-1/glucagon coagonism restores leptin responsiveness in mice maintained on a HFD, thus emphasizing the translational value of this polypharmacotherapy for the treatment of obesity and diabetes. Topics: Animals; Diet, High-Fat; Eating; Feeding Behavior; Glucagon; Glucagon-Like Peptide 1; Leptin; Male; Mice; Mice, Inbred C57BL; Mice, Obese; Obesity; Polyethylene Glycols; Receptors, Glucagon; Weight Loss | 2014 |
CD36- and GPR120-mediated Ca²⁺ signaling in human taste bud cells mediates differential responses to fatty acids and is altered in obese mice.
It is important to increase our understanding of gustatory detection of dietary fat and its contribution to fat preference. We studied the roles of the fat taste receptors CD36 and GPR120 and their interactions via Ca(2+) signaling in fungiform taste bud cells (TBC).. We measured Ca(2+) signaling in human TBC, transfected with small interfering RNAs against messenger RNAs encoding CD36 and GPR120 (or control small interfering RNAs). We also studied Ca(2+) signaling in TBC from CD36(-/-) mice and from wild-type lean and obese mice. Additional studies were conducted with mouse enteroendocrine cell line STC-1 that express GPR120 and stably transfected with human CD36. We measured release of serotonin and glucagon-like peptide-1 from human and mice TBC in response to CD36 and GPR120 activation.. High concentrations of linoleic acid induced Ca(2+) signaling via CD36 and GPR120 in human and mice TBC, as well as in STC-1 cells, and low concentrations induced Ca(2+) signaling via only CD36. Incubation of human and mice fungiform TBC with lineoleic acid down-regulated CD36 and up-regulated GPR120 in membrane lipid rafts. Obese mice had decreased spontaneous preference for fat. Fungiform TBC from obese mice had reduced Ca(2+) and serotonin responses, but increased release of glucagon-like peptide-1, along with reduced levels of CD36 and increased levels of GPR120 in lipid rafts.. CD36 and GPR120 have nonoverlapping roles in TBC signaling during orogustatory perception of dietary lipids; these are differentially regulated by obesity. Topics: Animals; Behavior, Animal; Calcium Signaling; CD36 Antigens; Cell Line; Diet, High-Fat; Disease Models, Animal; Food Preferences; Glucagon-Like Peptide 1; Humans; Inositol 1,4,5-Trisphosphate; Linoleic Acid; Membrane Microdomains; Mice; Mice, Inbred C57BL; Mice, Knockout; Obesity; Receptors, G-Protein-Coupled; RNA Interference; Serotonin; Taste; Taste Buds; Taste Perception; Transfection | 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 |
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 |
Nutrient-specific feeding and endocrine effects of jejunal infusions in obese animals.
Intestinal nutrient infusions result in variable decreases in food intake and body weight based on the nutrient type and the specific intestinal infusion site. We previously found that intrajejunal infusions of a fatty acid and glucose, but not casein hydrolysate, decreases food intake and body weight in lean chow-fed laboratory rats. To test whether obese, high fat-fed animals would show similar decreases in food intake and body weight in response to intrajejunal infusions of the same nutrients, equal kilocalorie loads of these nutrients (11.4 kcal) or vehicle were infused into the jejunum of obese, high fat-fed male Sprague-Dawley rats over 7 h/day for 5 consecutive days. Food intake was continuously monitored, and body weight was measured daily. After the infusion on the final day, rats were killed and plasma was collected. Similar to lean chow-fed rats, intrajejunal infusions of linoleic acid (LA) and glucose (Glu), but not casein hydrolysate (Cas), suppressed food intake with no compensatory increase in food intake after the infusion period. In contrast to lean chow-fed rats, only the LA, and not the Glu or Cas, produced decreases in body weight in the obese high fat-fed rat. There also were no differences in plasma glucagon-like peptide-1 levels in any of the nutrient infusion groups compared with saline infusion. These results suggest that there is a differential response to the same nutrients in lean vs. obese animals. Topics: Animals; Body Weight; Caseins; Eating; Endocrine System; Enteral Nutrition; Glucagon-Like Peptide 1; Glucose; Jejunum; Linoleic Acid; Male; Obesity; Peptide YY; Rats; Rats, Sprague-Dawley; Satiation | 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 |
Expression of the fatty acid receptor GPR120 in the gut of diet-induced-obese rats and its role in GLP-1 secretion.
Stimulation of the G protein coupled receptor GPR120 has been shown to have anti-inflammatory and insulin-sensitizing effects, to promote glucagon like peptide-1 (GLP-1) secretion, and to play a key role in sensing dietary fat and control energy balance. In a search for differentially expressed genes potentially involved in food intake and body-weight regulation we identified GPR120 to be differentially regulated in the intestine of selectively bred diet induced obese (DIO) and diet resistant (DR) rats. Subsequently we investigated the effect of GPR120 receptor stimulation with the long chain fatty acid alpha linolenic acid (ALA) on GLP-1 secretion in rats. Independent of diet (high or low fat), GPR120 expression showed a two-fold increase in the intestine of DIO compared to DR rats. In situ hybridization revealed a broad expression of GPR120 in the gut mucosa in both intestinal epithelial and endocrine cells. Using double in situ hybridization GPR120 mRNA did not appear to be enriched in preproglucagon expressing L-cells. In line with the anatomical data, ALA administration did not increase circulating GLP-1 levels. Our data shows a widespread expression of GPR120 in the gut epithelium and can not confirm a major role for GPR120 in the regulation of GLP-1 secretion. The broad expression of GPR120 in the gut epithelium supports reports indicating a putative role of GPR120 as a sensor of dietary fat. Topics: Administration, Oral; Animals; Caprylates; Diet; Gastrointestinal Tract; Glucagon-Like Peptide 1; Glucose; Insulin; Linoleic Acid; Male; Multiplex Polymerase Chain Reaction; Obesity; Proglucagon; Protein Transport; Rats; Rats, Sprague-Dawley; Rats, Wistar; Receptors, G-Protein-Coupled | 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 |
Gastric and intestinal satiation in obese and normal weight healthy people.
The gastrointestinal tract plays a key role in feelings of satiation. It is known that there is a reciprocal interaction between the stomach and intestine, but it is not known which factors are of gastric origin and which are intestinal. This three-step study therefore sought to provide illumination on satiation parameters with respect to body mass.. In the first part, the time needed to reach maximal satiation and total caloric intake was calculated after participants (20 normal weight, 20 obese) imbibed a standardized nutrient drink. In the second part gastric emptying of solids and liquids was evaluated using the (13)C-breath test (participants: 16 normal weight, 9 obese for gastric emptying of solids; 15 normal weight, 14 obese for gastric emptying of liquids). And in the third part, fasting and post-prandial plasma glucagon-like peptide-1 (GLP-1), peptide tyrosine tyrosine (PYY) and ghrelin levels were measured after a standardized nutrient drink (participants: 20 normal weight, 20 obese).. Our results show that, when compared to those of normal weight, obese participants reached maximal satiation sooner (P=0.006), their total intake of calories was higher (P=0.013), and their gastric emptying rates were delayed (P<0.001). Furthermore, their post-prandial increase in plasma GLP-1 and PYY was reduced, (P<0.001 for both), as was their ghrelin suppression (P=0.001).. We conclude that, in obese subjects gastric emptying can be impaired with delayed interaction of nutrients with the intestine resulting in decreased GLP-1 and PYY secretion. This could imply that obese participants would require more calories before their maximal satiation is reached and they stop eating. Topics: Adult; Dipeptides; Drinking; Eating; Energy Intake; Fasting; Female; Gastric Emptying; Ghrelin; Glucagon-Like Peptide 1; Humans; Male; Middle Aged; Obesity; Satiation; Stomach; Time Factors; Young Adult | 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 |
Glucagon-like peptide-1 production in the GLUTag cell line is impaired by free fatty acids via endoplasmic reticulum stress.
Glucagon-like peptide-1 (GLP-1) is secreted from intestinal L cells, enhances glucose-stimulated insulin secretion, and protects pancreas beta cells. However, few studies have examined hypernutrition stress in L cells and its effects on their function. Here, we demonstrated that a high-fat diet reduced glucose-stimulated secretion of GLP-1 and induced expression of an endoplasmic reticulum (ER) stress markers in the intestine of a diet-induced obesity mouse model.. To clarify whether ER stress in L cells caused the attenuation of GLP-1 secretion, we treated the mouse intestinal L cell line, GLUTag cells with palmitate or oleate.. Palmitate, but not oleate caused ER stress and decreased the protein levels of prohormone convertase 1/3 (PC1/3), an essential enzyme in GLP-1 production. The same phenomena were observed in GLUTag cells treated with in ER stress inducer, thapsigargin. Moreover, oleate improved palmitate-induced ER stress, reduced protein and activity levels of PC1/3, and attenuated GLP-1 secretion from GLUTag cells.. These results suggest that the intake of abundant saturated fatty acids induces ER stress in the intestine and decreases GLP-1 production. Topics: Animals; Blotting, Western; Diet, High-Fat; Endoplasmic Reticulum Stress; Enzyme Inhibitors; Glucagon-Like Peptide 1; L Cells; Male; Mice; Mice, Inbred C57BL; Obesity; Oleic Acid; Palmitates; Proprotein Convertase 1; Real-Time Polymerase Chain Reaction; Thapsigargin | 2014 |
Anti-obesity effects of KR-66195, a synthetic DPP-IV inhibitor, in diet-induced obese mice and obese-diabetic ob/ob mice.
We investigated whether KR-66195, a new synthetic dipeptidyl dipeptidase IV inhibitor, could prevent weight gain, as well as improving glycemic control in diet-induced obese (DIO) and ob/ob mice.. Male C57BL/6 mice were randomly assigned to the following groups: chow diet, high-fat diet, and high-fat diet with KR-66195. After KR-66195 treatment for eight weeks, intraperitoneal glucose tolerance tests were performed. A pair-feeding study was performed to investigate the mechanisms of the anti-obesity effects of KR-66195 in DIO mice. Female ob/ob mice were treated with KR-66195 for three weeks and compared to the vehicle-treated group.. In DIO mice, KR-66195 treatment increased the plasma glucagon-like peptide (GLP)-1 levels and improved glucose tolerance. This treatment also reduced body weight gain (5.38±0.94 g vs. 12.08±0.55 g, P<0.01) and food intake (2.41±0.09 g vs. 2.79±0.11 g, P<0.05). In ob/ob mice, KR-66195 treatment for three weeks resulted in comparable effects in DIO mice. In the pair-feeding study, KR-66195-treated mice exhibited a 16% increase in energy expenditure (kcal/h/kg lean body mass) without significant differences in body weight or activities compared with pair-fed mice. These results suggest that KR-66195 prevented weight gain in DIO mice by decreasing food intake, as well as increasing energy expenditure.. KR-66195 markedly increased plasma levels of GLP-1, resulting in the probable improvement in glucose tolerance and reduced body weight and food intake. Thus, KR-66195 might be further developed as a therapeutic drug to treat obesity, as well as diabetes. Topics: Animals; Anti-Obesity Agents; Blood Glucose; Body Composition; Diabetes Mellitus; Diet, High-Fat; Dipeptidyl Peptidase 4; Eating; Energy Metabolism; Enzyme Inhibitors; Female; Glucagon-Like Peptide 1; Glucose Tolerance Test; Male; Mice; Mice, Inbred C57BL; Mice, Obese; Obesity; Random Allocation; Thiazolidines; Treatment Outcome; Valine; Weight Gain | 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 |
Liraglutide suppresses obesity and hyperglycemia associated with increases in hepatic fibroblast growth factor 21 production in KKAy mice.
Social isolation contributes to the development of obesity and insulin-independent diabetes in KKA(y) mice. Here we show that systemic administration of liraglutide, a long-acting human glucagon-like peptide-1 (GLP-1) analog, significantly decreased food intake, body weight, and blood glucose levels at 24 h after its administration while having no significant effects on plasma insulin and glucagon levels in individually housed KKA(y) mice. In addition, the systemic administration of liraglutide significantly increased plasma fibroblast growth factor (Fgf) 21 levels (1.8-fold increase) associated with increases in the expression of hepatic Fgf21 (1.9-fold increase) and Pparγ (1.8-fold increase), while having no effects on the expression of hepatic Pparα and Fgf21 in white adipose tissue. Moreover, systemic administration of liraglutide over 3 days significantly suppressed food intake, body weight gain, and hyperglycemia in KKA(y) mice. On the other hand, despite remarkably increased plasma active GLP-1 levels (4.2-fold increase), the ingestion of alogliptin, a selective dipeptidyl peptidase-4 inhibitor, over 3 days had no effects on food intake, body weight, blood glucose levels, and plasma Fgf21 levels in KKA(y) mice. These findings suggest that systemic administration of liraglutide induces hepatic Fgf21 production and suppresses the social isolation-induced obesity and diabetes independently of insulin, glucagon, and active GLP-1 in KKA(y) mice. Topics: Adipose Tissue, White; Animals; Blood Glucose; Body Weight; Eating; Fibroblast Growth Factors; Glucagon-Like Peptide 1; Humans; Hyperglycemia; Liraglutide; Mice; Obesity | 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 |
JTT-130, a novel intestine-specific inhibitor of microsomal triglyceride transfer protein, improves hyperglycemia and dyslipidemia independent of suppression of food intake in diabetic rats.
We investigated the effects of JTT-130 on glucose and lipid metabolism independent of the suppression of feeding by comparing with pair-fed animals. Male Zucker diabetic fatty (ZDF) rats were divided into control, JTT-130 treatment, and pair-fed groups. The rats were fed with a regular powdered diet with or without JTT-130 as a food admixture for 6 weeks. We compared the effects on glucose and lipid metabolism in JTT-130 treatment group with those in pair-fed group. RESULTS. Hyperglycemia in ZDF rats was prevented in both JTT-130 treatment and pair-fed groups, but the prevention in pair-fed group became poor with time. Moreover, reduction in plasma cholesterol levels was observed only in JTT-130 treatment group. JTT-130 treatment group showed improved glucose tolerance at 5 weeks after treatment and significant elevation of portal glucagon-like peptide-1 (GLP-1) levels. The hepatic lipid content in JTT-130 treatment group was decreased as compared with pair-fed group. Furthermore, pancreatic protection effects, such as an increase in pancreatic weight and an elevation of insulin-positive area in islets, were observed after JTT-130 treatment. CONCLUSIONS. JTT-130 improves hyperglycemia and dyslipidemia via a mechanism independent of suppression of food intake, which is ascribed to an enhancement of GLP-1 secretion and a reduction of lipotoxicity. Topics: Animals; Benzamides; Carrier Proteins; Diabetes Complications; Diabetes Mellitus; Dyslipidemias; Enteroendocrine Cells; Gastrointestinal Agents; Glucagon-Like Peptide 1; Hyperglycemia; Hypoglycemic Agents; Hypolipidemic Agents; Lipid Metabolism; Liver; Male; Malonates; Obesity; Organ Size; Pancreas; Rats; Rats, Zucker | 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 |
DPP4 inhibition attenuates filtration barrier injury and oxidant stress in the zucker obese rat.
Obesity-related glomerulopathy is characterized initially by glomerular hyperfiltration with hypertrophy and then development of proteinuria. Putative mechanisms include endothelial dysfunction and filtration barrier injury due to oxidant stress and immune activation. There has been recent interest in targeting dipeptidyl peptidase 4 (DPP4) enzyme due to increasing role in non-enzymatic cellular processes.. The Zucker obese (ZO) rat (aged 8 weeks) fed a normal chow or diet containing the DPP4 inhibitor linagliptin for 8 weeks (83 mg/kg rat chow) was utilized.. Compared to lean controls, there were increases in plasma DPP4 activity along with proteinuria in ZO rats. ZO rats further displayed increases in glomerular size and podocyte foot process effacement. These findings occurred in parallel with decreased endothelial stromal-derived factor-1α (SDF-1α), increased oxidant markers, and tyrosine phosphorylation of nephrin and serine phosphorylation of the mammalian target of rapamycin (mTOR). DPP4 inhibition improved proteinuria along with filtration barrier remodeling, circulating and kidney tissue DPP4 activity, increased active glucagon like peptide-1 (GLP-1) as well as SDF-1α, and improved oxidant markers and the podocyte-specific protein nephrin.. These data support a role for DPP4 in glomerular filtration function and targeting DPP4 with inhibition improves oxidant stress-related glomerulopathy and associated proteinuria. Topics: Animals; Dipeptidyl-Peptidase IV Inhibitors; Glomerular Filtration Barrier; Glucagon-Like Peptide 1; Hypoglycemic Agents; Kidney Diseases; Kidney Glomerulus; Male; Obesity; Oxidative Stress; Podocytes; Rats; Rats, Zucker | 2014 |
Involvement of glucagon-like peptide 1 in the glucose homeostasis regulation in obese and pituitary-dependent hyperadrenocorticism affected dogs.
The incretin glucagon-like peptide 1 (GLP-1) enhances insulin secretion. The aim of this study was to assess GLP-1, glucose and insulin concentrations, Homeostatic Model Assessment (HOMA insulin sensitivity and HOMA β-cell function) in dogs with pituitary-dependent hyperadrenocorticism (PDH), and compare these values with those in normal and obese dogs. The Oral Glucose Tolerance Test was performed and the glucose, GLP-1 and insulin concentrations were evaluated at baseline, and after 15, 30, 60 and 120 minutes. Both basal concentration and those corresponding to the subsequent times, for glucose, GLP-1 and insulin, were statistically elevated in PDH dogs compared to the other groups. Insulin followed a similar behaviour together with variations of GLP-1. HOMA insulin sensitivity was statistically decreased and HOMA β-cell function increased in dogs with PDH. The higher concentrations of GLP-1 in PDH could play an important role in the impairment of pancreatic β-cells thus predisposing to diabetes mellitus. Topics: Adrenocortical Hyperfunction; Animals; Blood Glucose; Diabetes Mellitus; Dog Diseases; Dogs; Female; Glucagon-Like Peptide 1; Glucose; Glucose Tolerance Test; Homeostasis; Insulin; Male; Obesity; Pituitary ACTH Hypersecretion; Risk Factors; Time Factors | 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 |
Combination of peptide YY3-36 with GLP-1(7-36) amide causes an increase in first-phase insulin secretion after IV glucose.
The combination of peptide YY (PYY) and glucagon-like peptide-1 (GLP-1) has been proposed as a potential treatment for diabetes and obesity. However, the combined effects of these hormones, PYY(3-36) and GLP-1(7-36 amide), on glucose homeostasis are unknown.. This study sought to investigate the acute effects of PYY(3-36) and GLP-1(7-36) amide, individually and in combination, on insulin secretion and sensitivity.. Using a frequently sampled iv glucose tolerance test (FSIVGTT) and minimal modeling, this study measured the effects of PYY(3-36) alone, GLP-1(7-36) amide alone, and a combination of PYY(3-36) and GLP-1(7-36) amide on acute insulin response to glucose (AIRg) and insulin sensitivity index (SI) in 14 overweight human volunteers, studied in a clinical research facility.. PYY(3-36) alone caused a small but nonsignificant increase in AIRg. GLP-1(7-36) amide alone and the combination of PYY(3-36) and GLP-1(7-36) amide did increase AIRg significantly. No significant differences in SI were observed with any intervention.. PYY(3-36) lacks any significant acute effects on first-phase insulin secretion or SI when tested using an FSIVGTT. Both GLP-1(7-36) amide alone and the combination of PYY3-36 and GLP-1(7-36) amide increase first-phase insulin secretion. There does not seem to be any additive or synergistic effect between PYY(3-36) and GLP-1(7-36) amide on first-phase insulin secretion. Neither hormone alone nor the combination had any significant effects on SI. Topics: Adult; Blood Glucose; Female; Glucagon-Like Peptide 1; Glucose; Glucose Tolerance Test; Homeostasis; Humans; Insulin; Insulin Resistance; Male; Middle Aged; Obesity; Overweight; Peptide Fragments; Peptide YY; Young Adult | 2014 |
The DPP-IV inhibitor linagliptin and GLP-1 induce synergistic effects on body weight loss and appetite suppression in the diet-induced obese rat.
Linagliptin is a dipeptidyl peptidase (DPP)-IV inhibitor approved for the treatment of type 2 diabetes. DPP-IV inhibitors are considered weight neutral, suggesting that elevation of endogenous incretin levels is not sufficient to promote weight loss per se. Here we evaluated the effect of linagliptin in combination with subcutaneous treatment of GLP-1(7-36) on body weight regulation in diet-induced obese (DIO) rats. Linagliptin administered perorally (1.5mg/kg, b.i.d.), but not subcutaneously (0.5mg/kg, b.i.d.), evoked a very modest body weight loss (2.2%) after 28 days of treatment. GLP-1 (0.5mg/kg, s.c.) treatment alone induced a body weight loss of 4.1%. In contrast, combined linagliptin (1.5mg/kg, p.o., or 0.5mg/kg, s.c.) and GLP-1 (0.5mg/kg) treatment evoked a marked anorectic response with both routes of linagliptin administration being equally effective on final body weight loss (7.5-8.0%). In comparison, liraglutide monotherapy (0.2mg/kg, s.c., b.i.d.) reduced body weight by 10.1%. Interestingly, the weight lowering effect of combined linagliptin and GLP-1 treatment was associated with a marked increase in chow preference, being more pronounced as compared to liraglutide treatment. In addition, linagliptin and GLP-1 co-treatment, but not liraglutide, specifically increased prepro-dynorphin mRNA levels in the caudate-putamen, an effect not obtained with administration of the compounds individually. In conclusion, co-treatment with linagliptin and GLP-1 synergistically reduces body weight in obese rats. The anti-obesity effect was caused by appetite suppression with a concomitant change in diet preference, which may potentially be associated with increased dynorphin activity in forebrain regions involved in reward anticipation and habit learning. Topics: Animals; Appetite Depressants; Body Weight; Diet, High-Fat; Dietary Sucrose; Dipeptidyl-Peptidase IV Inhibitors; Drug Synergism; Drug Therapy, Combination; Glucagon-Like Peptide 1; Linagliptin; Male; Obesity; Purines; Quinazolines; Rats; Rats, Sprague-Dawley; Weight Loss | 2014 |
Can Bayliss and Starling gut hormones cure a worldwide pandemic?
Bayliss and Starling first coined the term 'hormone' with reference to secretin, a substance they found that was produced by the gut, but released into the blood stream to act at a distance. The intestine is now known as the largest endocrine organ in the body, and it produces numerous hormones with a wide range of functions. These include controlling appetite and energy homeostasis. Obesity is one of the greatest health threats facing the world today. At present, the only successful treatment is surgery. Bariatric procedures such as the Roux-en-Y bypass work by elevating gut hormones that induce satiety. Significant research has gone into producing versions of these hormones that can be delivered therapeutically to treat obesity. This review looks at the role of gut hormones in obesity, and the development of gut hormone-derived obesity treatments. Topics: Animals; Appetite; Appetite Regulation; Awards and Prizes; Bariatric Surgery; Energy Metabolism; Female; Gastrointestinal Hormones; Glucagon-Like Peptide 1; Humans; Male; Obesity; Pandemics; Peptide YY; Societies, Scientific | 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 |
Effect of liraglutide administration and a calorie-restricted diet on lipoprotein profile in overweight/obese persons with prediabetes.
To evaluate the effects of 14 weeks of liraglutide plus modest caloric restriction on lipid/lipoprotein metabolism in overweight/obese persons with prediabetes.. Volunteers with prediabetes followed a calorie-restricted diet (-500 Kcal/day) plus liraglutide (n = 23) or placebo (n = 27) for 14 weeks. The groups were similar in age (58 ± 7 vs. 58 ± 8 years) and body mass index (31.9 ± 2.8 vs. 31.9 ± 3.5 kg/m(2)). A comprehensive lipid/lipoprotein profile was obtained before and after intervention using vertical auto profile (VAP). Weight loss was greater in the liraglutide group than in the placebo group (6.9 vs. 3.3 kg, p < 0.001), as was the fall in fasting plasma glucose concentration (9.9 mg/dL vs. 0.3 mg/dL, p < 0.001). VAP analysis revealed multiple improvements in lipid/lipoprotein metabolism in liraglutide-treated compared with placebo-treated volunteers, including decreases in concentrations of total cholesterol, low-density lipoprotein cholesterol and several of its subclasses, triglyceride, and non-high-density cholesterol. The liraglutide-treated group also had a significant shift away from small, dense low-density lipoprotein-particles, as well as decreases in apolipoprotein B concentration and ratio of apolipoprotein B/apolipoprotein A-1. There were no significant changes in the lipoprotein profile in the placebo-treated group.. Treatment with liraglutide plus modest calorie restriction led to enhanced weight loss, a decrease in fasting plasma glucose concentration, and improvement in multiple aspects of lipid/lipoprotein metabolism associated with increased cardiovascular disease (CVD) risk. The significant clinical benefit associated with liraglutide-assisted weight loss in a group at high risk for CVD - obese/overweight individuals with prediabetes - as seen in our pilot study, suggests that this approach deserves further study. Topics: Aged; Apolipoprotein A-I; Apolipoproteins B; Blood Glucose; Body Mass Index; Caloric Restriction; Cholesterol, VLDL; Combined Modality Therapy; Glucagon-Like Peptide 1; Humans; Hypoglycemic Agents; Lipoprotein(a); Lipoproteins, HDL; Liraglutide; Male; Middle Aged; Obesity; Overweight; Prediabetic State | 2014 |
Cannabinoid receptor 1 antagonist treatment induces glucagon release and shows an additive therapeutic effect with GLP-1 agonist in diet-induced obese mice.
Cannabinoid 1 (CB1) receptor antagonists reduce body weight and improve insulin sensitivity. Preclinical data indicates that an acute dose of CB1 antagonist rimonabant causes an increase in blood glucose. A stable analog of glucagon-like peptide 1 (GLP-1), exendin-4 improves glucose-stimulated insulin secretion in pancreas, and reduces appetite through activation of GLP-1 receptors in the central nervous system and liver. We hypothesized that the insulin secretagogue effect of GLP-1 agonist exendin-4 may synergize with the insulin-sensitizing action of rimonabant. Intraperitoneal as well as intracerebroventricular administration of rimonabant increased serum glucose upon glucose challenge in overnight fasted, diet-induced obese C57 mice, with concomitant rise in serum glucagon levels. Exendin-4 reversed the acute hyperglycemia induced by rimonabant. The combination of exendin-4 and rimonabant showed an additive effect in the food intake, and sustained body weight reduction upon repeated dosing. The acute efficacy of both the compounds was additive for inducing nausea-like symptoms in conditioned aversion test in mice, whereas exendin-4 treatment antagonized the effect of rimonabant on forced swim test upon chronic dosing. Thus, the addition of exendin-4 to rimonabant produces greater reduction in food intake owing to increased aversion, but reduces the other central nervous system side effects of rimonabant. The hyperglucagonemia induced by rimonabant is partially responsible for enhancing the antiobesity effect of exendin-4. Topics: Animals; Anti-Obesity Agents; Blood Glucose; Body Weight; Diet, High-Fat; Drug Synergism; Eating; Exenatide; Glucagon; Glucagon-Like Peptide 1; Insulin Resistance; Male; Mice, Inbred C57BL; Mice, Obese; Obesity; Peptides; Piperidines; Pyrazoles; Receptor, Cannabinoid, CB1; Rimonabant; Venoms | 2014 |
Agavins from Agave angustifolia and Agave potatorum affect food intake, body weight gain and satiety-related hormones (GLP-1 and ghrelin) in mice.
Agavins act as a fermentable dietary fiber and have attracted attention due to their potential for reducing the risk of disease. Therefore, we evaluated the effect of supplementation using 10% agavins with a short-degree of polymerization (SDP) from Agave angustifolia Haw. (AASDP) or Agave potatorum Zucc. (APSDP) along with chicory fructans (RSE) as a reference for 5 weeks, on the energy intake, body weight gain, satiety-related hormones from the gut and blood (GLP-1 and ghrelin), blood glucose and lipids, and short-chain fatty acids (SCFAs) from the gut of ad libitum-fed mice. We evaluated the energy intake daily and weight gain every week. At the end of the experiment, portal vein blood samples as well as intestinal segments and the stomach were collected to measure glucagon-like peptide-1 (GLP-1) and ghrelin using RIA and ELISA kits, respectively. Colon SCFAs were measured using gas chromatography. The energy intake, body weight gain, and triglycerides were lower in the fructan-fed mice than in the STD-fed mice. The AASDP, APSDP, and RSE diets increased the serum levels of GLP-1 (40, 93, and 16%, respectively vs. STD) (P ≤ 0.05), whereas ghrelin was decreased (16, 38, and 42%, respectively) (P ≤ 0.05). Butyric acid increased significantly in the APSDP-fed mice (26.59 mmol g(-1), P ≤ 0.001) compared with that in the AASDP- and RSE-fed mice. We concluded that AASDP and APSDP are able to promote the secretion of the peptides involved in appetite regulation, which might help to control obesity and its associated metabolic disorder. Topics: Agave; Animals; Blood Glucose; Dietary Fiber; Eating; Energy Intake; Ghrelin; Glucagon-Like Peptide 1; Humans; Male; Mice; Mice, Inbred C57BL; Obesity; Triglycerides; Weight Gain | 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 |
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 |
Beta and alpha cell function in metabolically healthy but obese subjects: relationship with entero-insular axis.
Obesity is widely acknowledged as a critical risk factor for metabolic complications. Among obese subjects, there is a phenotype of metabolically healthy but obese (MHO) individuals that shows a favorable cardiometabolic risk profile. We aimed to evaluate the potential mechanisms underlying the metabolic profile of this subset, including alpha and beta cell function and entero-insular axis.. One hundred twenty-nine obese and 24 nonobese subjects were studied. Obese participants were defined as MHO or at-risk obese, according to the homeostasis model of assessment-insulin resistance (HOMA-IR) index (MHO: lower tertile of HOMA-IR, n = 43; at-risk: upper tertile of HOMA-IR index, n = 41). Insulin, glucagon, and incretin responses after a 120' oral glucose tolerance test (75-g OGTT) were investigated.. During OGTT, MHO individuals showed in comparison with at-risk subjects: lower fasting and afterloads plasma levels of glucose, insulin, and C-peptide; higher disposition index; lower fasting (P = 0.004) and at 30' (P = 0.01) plasma glucose-dependent insulinotropic polypeptide (GIP) levels; lower area under the curve (AUC) (0-30) for GIP (P = 0.008); higher glucagon-like peptide-1 (GLP-1) plasma levels at 90' (P = 0.02) and 120' (P = 0.02); lower glucagon plasma levels at baseline (P = 0.04) and at 30' (P = 0.03); and appropriate glucagon suppression after the oral glucose load.. MHO subjects show, as well as normal-weight individuals, a lower diabetogenic profile by virtue of higher disposition index and unaffected entero-insular axis. At-risk obese individuals present increased GIP levels that might play a role in determining increased glucagon secretion and inappropriate glucagon responses after glucose load, thus contributing to impaired glucose homeostasis. Topics: Adult; Area Under Curve; Blood Glucose; C-Peptide; Fasting; Female; Gastric Inhibitory Polypeptide; Glucagon; Glucagon-Like Peptide 1; Glucagon-Secreting Cells; Glucose Tolerance Test; Humans; Insulin; Insulin Resistance; Insulin-Secreting Cells; Male; Obesity | 2013 |
A water-alcohol extract of Citrus grandis whole fruits has beneficial metabolic effects in the obese Zucker rats fed with high fat/high cholesterol diet.
Epidemiological studies suggest that citrus fruits and compounds such as flavonoids, limonoids and pectins have health promoting effects. Our aim was to study the effects of Citrus grandis (L.) Osbeck var. tomentosa hort. fruit extract on the energy metabolism. A whole fruit powder from dry water and alcohol extracts of C. grandis containing 19% naringin flavonoid was prepared. The effects of the citrus extract were followed in the obese Zucker rats fed with the HFD. The circulatory levels of GLP-1 decreased significantly by the extract in comparison to the HFD group, whereas the decreased ghrelin levels were reversed. The levels of PYY were decreased in all HFD groups. The leptin amounts decreased but not significantly whereas insulin and amylin were unchanged. The cholesterol and glucose levels were somewhat but not systematically improved in the HFD fed rats. Further studies are needed to identify the active compounds and their mechanisms. Topics: Animals; Blood Glucose; Cholesterol; Citrus; Diet, High-Fat; Fruit; Glucagon-Like Peptide 1; Humans; Leptin; Male; Obesity; Plant Extracts; Rats; Rats, Zucker | 2013 |
Vertical sleeve gastrectomy is effective in two genetic mouse models of glucagon-like Peptide 1 receptor deficiency.
Glucagon-like peptide 1 (GLP-1) is a peptide hormone that is released from the gut in response to nutrient ingestion and that has a range of metabolic effects, including enhancing insulin secretion and decreasing food intake. Postprandial GLP-1 secretion is greatly enhanced in rats and humans after some bariatric procedures, including vertical sleeve gastrectomy (VSG), and has been widely hypothesized to contribute to reduced intake, weight loss, and the improvements in glucose homeostasis after VSG. We tested this hypothesis using two separate models of GLP-1 receptor deficiency. We found that VSG-operated GLP-1 receptor-deficient mice responded similarly to wild-type controls in terms of body weight and body fat loss, improved glucose tolerance, food intake reduction, and altered food selection. These data demonstrate that GLP-1 receptor activity is not necessary for the metabolic improvements induced by VSG surgery. Topics: Animals; Body Composition; Body Weight; Eating; Exenatide; Gastrectomy; Glucagon-Like Peptide 1; Glucagon-Like Peptide-1 Receptor; Insulin Resistance; Mice; Mice, Knockout; Obesity; Peptides; Postprandial Period; Receptors, Glucagon; Venoms | 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 |
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 |
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 |
Prior exercise and postprandial incretin responses in lean and obese individuals.
The incretin hormones glucagon-like peptide-1 (GLP-1) and glucose-dependent insulinotropic polypeptide (GIP) help regulate postprandial triacylglycerol (TAG) and insulin concentrations, but the effects of acute aerobic exercise on GLP-1 or GIP responses are unclear. The purpose of this study was to determine whether reductions in postprandial TAG and insulin with exercise are associated with GLP-1 and GIP responses.. Thirteen normal-weight (NW) and 13 obese (Ob) individuals participated in two, 4-d trials in random order including an exercise (EX) and a no exercise (NoEX) trial. Diet was controlled during both trials. The EX trial consisted of 1 h of treadmill walking (55%-60% of V˙O2peak) during the evening of day 3 of the trial, 12 h before a 4-h mixed meal test on day 4, during which frequent blood samples were collected to assess postprandial lipemia, glycemia, insulin, C-peptide, GIP, and GLP-1 responses. Insulin secretion was estimated using the insulinogenic index, and insulin clearance was estimated using the ratio of insulin to C-peptide.. Postprandial TAG were 29% lower after EX in Ob individuals (P < 0.05) but were not significantly altered in NW individuals (P > 0.05). The drop in postprandial HDL cholesterol was attenuated with EX in Ob individuals (P < 0.05). Insulin responses were 14% lower after EX in Ob individuals (P < 0.05), and this was associated with reduced insulin secretion (P < 0.05), with no change in insulin clearance (P > 0.05). Glucose, C-peptide, GIP, and GLP-1 were not different between trials.. A 1-h bout of moderate-intensity aerobic exercise the night before a mixed meal attenuates TAG and insulin responses in Ob but not NW individuals, an effect not associated with altered GLP-1 or GIP responses. Topics: Adult; C-Peptide; Cholesterol, HDL; Exercise Test; Fasting; Female; Gastric Inhibitory Polypeptide; Glucagon-Like Peptide 1; Humans; Insulin; Male; Obesity; Oxygen Consumption; Physical Exertion; Postprandial Period; Triglycerides; Walking; Young Adult | 2013 |
A surgical model in male obese rats uncovers protective effects of bile acids post-bariatric surgery.
Bariatric surgery elevates serum bile acids. Conjugated bile acid administration, such as tauroursodeoxycholic acid (TUDCA), improves insulin sensitivity, whereas short-circuiting bile acid circulation through ileal interposition surgery in rats raises TUDCA levels. We hypothesized that bariatric surgery outcomes could be recapitulated by short circuiting the normal enterohepatic bile circulation. We established a model wherein male obese rats underwent either bile diversion (BD) or Sham (SH) surgery. The BD group had a catheter inserted into the common bile duct and its distal end anchored into the middistal jejunum for 4-5 weeks. Glucose tolerance, insulin and glucagon-like peptide-1 (GLP-1) response, hepatic steatosis, and endoplasmic reticulum (ER) stress were measured. Rats post-BD lost significantly more weight than the SH rats. BD rats gained less fat mass after surgery. BD rats had improved glucose tolerance, increased higher postprandial glucagon-like peptide-1 response and serum bile acids but less liver steatosis. Serum bile acid levels including TUDCA concentrations were higher in BD compared to SH pair-fed rats. Fecal bile acid levels were not different. Liver ER stress (C/EBP homologous protein mRNA and pJNK protein) was decreased in BD rats. Bile acid gavage (TUDCA/ursodeoxycholic acid [UDCA]) in diet-induced obese rats, elevated serum TUDCA and concomitantly reduced hepatic steatosis and ER stress (C/EBP homologous protein mRNA). These data demonstrate the ability of alterations in bile acids to recapitulate important metabolic improvements seen after bariatric surgery. Further, our work establishes a model for focused study of bile acids in the context of bariatric surgery that may lead to the identification of therapeutics for metabolic disease. Topics: Animals; Bariatric Surgery; Bile Acids and Salts; Endoplasmic Reticulum Stress; Glucagon-Like Peptide 1; Male; Obesity; Rats; Taurochenodeoxycholic Acid | 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 |
Swim training restores glucagon-like peptide-1 insulinotropic action in pancreatic islets from monosodium glutamate-obese rats.
Glucagon-like peptide-1 (GLP-1) is an important modulator of insulin secretion by endocrine pancreas. In the present study, we investigated the effect of swim training on GLP-1 insulinotropic action in pancreatic islets from monosodium glutamate (MSG)-obese rats.. Obesity was induced by neonatal MSG administration. MSG-obese and control (CON) exercised rats swam for 30 min (3 times week(-1) ) for 10 weeks. Pancreatic islets were isolated by colagenase technique and incubated with low (5.6 mM) or high (16.7 mM) glucose concentrations in the presence or absence of GLP-1 (10 nM). In addition, GLP-1 gene expression in ileum was quantified in fasting and glucose conditions.. Exercise reduced obesity and hyperinsulinemia in MSG-obese rats. Swim training also inhibited glucose-induced insulin secretion in islets from both groups. Islets from MSG-obese rats maintained GLP-1 insulinotropic response in low glucose concentration. In contrast, in the presence of high glucose concentration, GLP-1 insulinotropic action was absent in islets from MSG-obese rats. Islets from MSG-exercised rats showed reduced GLP-1 insulinotropic action in the presence of low glucose. However, in high glucose concentration swim training restored GLP-1 insulinotropic response in islets from MSG-obese rats. In all groups, glucose intake increased GLP-1 immunoreactivity and gene expression in ileum cells in relation to fasting conditions. Swim training reduced these parameters only in ileum cells from CON-exercised rats. Neither MSG treatment nor exercise affected GLP-1 expression in the ileum.. Exercise avoids insulin hypersecretion restoring GLP-1's insulinotropic action in pancreatic islets from MSG-obese rats. Topics: Animals; Animals, Newborn; Glucagon-Like Peptide 1; Glucose; Insulin; Islets of Langerhans; Obesity; Physical Conditioning, Animal; Rats, Wistar; Sodium Glutamate; Swimming | 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 |
GLP-1R agonism enhances adjustable gastric banding in diet-induced obese rats.
Bariatric procedures vary in efficacy, but overall are more effective than behavioral and pharmaceutical treatment. Roux-en-Y gastric bypass causes increased secretion of glucagon-like peptide 1 (GLP-1) and reduces body weight (BW) more than adjustable gastric banding (AGB), which does not trigger increased GLP-1 secretion. Since GLP-1-based drugs consistently reduce BW, we hypothesized that GLP-1 receptor (GLP-1R) agonists would augment the effects of AGB. Male Long-Evans rats with diet-induced obesity received AGB implantation or sham surgery. GLP-1R agonism, cannabinoid receptor-1 (CB1-R) antagonism, or vehicle was combined with inflation to evaluate interaction between AGB and pharmacological treatments. GLP1-R agonism reduced BW in both sham and AGB rats (left uninflated) compared with vehicle-treated animals. Subsequent band inflation was ineffective in vehicle-treated rats but enhanced weight loss stimulated by GLP1-R agonism. In contrast, there was no additional BW loss when CB1-R antagonism was given with AGB. We found band inflation to trigger neural activation in areas of the nucleus of the solitary tract known to be targeted by GLP-1R agonism, offering a potential mechanism for the interaction. These data show that GLP-1R agonism, but not CB1-R antagonism, improves weight loss achieved by AGB and suggest an opportunity to optimize bariatric surgery with adjunctive pharmacotherapy. Topics: Animals; Body Composition; Eating; Exenatide; Gastric Bypass; Gastroplasty; Glucagon-Like Peptide 1; Glucagon-Like Peptide-1 Receptor; Immunohistochemistry; Male; Obesity; Peptides; Rats; Rats, Long-Evans; Receptors, Cannabinoid; Receptors, Glucagon; Venoms | 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 |
Beneficial metabolic effects of a probiotic via butyrate-induced GLP-1 hormone secretion.
Obesity and diabetes are associated with excess caloric intake and reduced energy expenditure resulting in a negative energy balance. The incidence of diabetes has reached epidemic proportions, and childhood diabetes and obesity are increasing alarmingly. Therefore, it is important to develop safe, easily deliverable, and economically viable treatment alternatives for these diseases. Here, we provide data supporting the candidacy of probiotics as such a therapeutic modality against obesity and diabetes. Probiotics are live bacteria that colonize the gastrointestinal tract and impart beneficial effects for health. However, their widespread prescription as medical therapies is limited primarily because of the paucity of our understanding of their mechanism of action. Here, we demonstrate that the administration of a probiotic, VSL#3, prevented and treated obesity and diabetes in several mouse models. VSL#3 suppressed body weight gain and insulin resistance via modulation of the gut flora composition. VSL#3 promoted the release of the hormone GLP-1, resulting in reduced food intake and improved glucose tolerance. The VSL#3-induced changes were associated with an increase in the levels of a short chain fatty acid (SCFA), butyrate. Using a cell culture system, we demonstrate that butyrate stimulated the release of GLP-1 from intestinal L-cells, thereby providing a plausible mechanism for VSL#3 action. These findings suggest that probiotics such as VSL#3 can modulate the gut microbiota-SCFA-hormone axis. Moreover, our results indicate that probiotics are of potential therapeutic utility to counter obesity and diabetes. Topics: Animals; Appetite Regulation; Butyrates; Diabetes Mellitus, Experimental; Glucagon-Like Peptide 1; Insulin Resistance; Intestinal Mucosa; Intestines; Male; Mice; Obesity; Probiotics | 2013 |
Alteration of sweet taste in high-fat diet induced obese rats after 4 weeks treatment with exenatide.
Exenatide, a glucagon-like peptide-1 (GLP-1) receptor agonist, is effective in inducing weight loss. The exact mechanisms are not fully understood. Reduced appetite and food intake may play important roles. Sweet taste contributes to food palatability, which promotes appetite. Interestingly, GLP-1 and its receptor are expressed in the taste buds of rodents and their interaction has an effect on mediating sweet taste sensitivity. Our aim was to investigate whether sweet taste will be changed after long term treatment with exenatide. The results showed that high-fat diet induced obese rats (HF-C) presented metabolic disorders in food intake, body weight, blood glucose and lipid metabolism compared with long term exenatide treated obese rats (EX) and normal chow fed control rats (NC). Meanwhile, greater preference for sweet taste was observed in HF-C rats but not in EX rats. Compared with NC rats, brain activities induced by sweet taste stimulation were stronger in HF-C rats, however these stronger activities were not found in EX rats. We further found reduced sweet taste receptor T1R3 in circumvallte taste buds of HF-C rats, while GLP-1 was increased. Besides, serum leptin was evaluated in HF-C rats with decreased leptin receptor expressed in taste buds. These changes were not observed in EX rats, which suggest them to be the underlying hormone and molecular mechanisms responsible for alterations in sweet taste of HF-C rats and EX rats. In summary, our results suggest that long term treatment with exenatide could benefit dietary obese rats partially by reversing sweet taste changes. Topics: Animals; Blood Glucose; Body Weight; Choice Behavior; Diet, High-Fat; Drug Administration Schedule; Eating; Exenatide; Gene Expression; Glucagon-Like Peptide 1; Hypoglycemic Agents; Leptin; Lipid Metabolism; Male; Obesity; Peptides; Rats; Rats, Wistar; Receptors, G-Protein-Coupled; Taste; Taste Buds; Venoms | 2013 |
Acute effects of oral preloads with increasing energy density on gastric emptying, gut hormone release, thermogenesis and energy intake, in overweight and obese men.
This study investigated the effect of high- and low-energy density preloads on gastrointestinal and metabolic factors, which act to regulate acute energy intake. Sixteen overweight and obese men (BMI range: 27.2-36.5 kg/m2) each received 3 oral preloads in randomised order: i) high-energy-density, high-fat (1.5 kcal/g), ii) low-energy density, high-fat (1.1 kcal/g), and iii) low-energy-density, high-protein (1.1 kcal/g). Over 180 min, gastric emptying, plasma glucagon-like peptide-1 concentrations, and diet-induced thermogenesis were assessed, and subsequent energy intake was determined. Total energy intake did not differ between preloads (high-energy-density, high-fat, 2059±72 kilocalories (kcal); low-energy-density, high-fat, 1876±91 kcal; and low-energy-density, high protein, 1867±63 kcal). Gastric emptying was slower following the high-energy-density, high-fat preload (158±8 min) compared with the low-energy-density, high-protein preload (130±9 min) (p=0.05), but did not differ between the high-energy-density, high-fat and low-energy-density, high-fat (147±8 min) preloads. Plasma glucagon- like peptide-1 did not differ substantially between preloads. Diet-induced thermogenesis was lower following high-energy-density, high-fat (10.4±0.7 %) than low-energy-density, high-fat (14.9±1.2 %) and low-energy density, high-protein (18.1±1.1 %) preloads (p<0.01 for both). We conclude that an increased energy density slows gastric emptying and reduces thermogenesis, but that a high fat content overrides the effect of energy density on gastric emptying. The counter-regulatory modulation of these gastric and metabolic factors may explain, at least in part, the lack of differences in subsequent energy intake in response to oral preloads with increasing energy density.. 此研究為偵測高能量密度及低能量密度配方,對於調節急性能量攝取的腸胃道 及代謝因子的影響。計16 位過重及肥胖的男性(身體質量指數: 27.2-36.5 kg/m2),每位受試者隨機接受三種口服配方:i)高能量密度高脂配方(1.5 kcal/g),ii)低能量密度高脂配方(1.1 kcal/g),以及iii)低能量密度高蛋白配方 (1.1 kcal/g)。服用配方3 小內,評估胃排空狀況、血漿類升糖激素胜肽-1(GLP- 1)濃度、飲食誘導的產熱效應,並偵測後續的能量攝取。合計後續進食與高能 量密度高脂配方、低能量密度高脂配方或低能量高蛋白配方的平均總能量攝取 分別為2059±72 kcal、1876±91 kcal 及1867±63 kcal,三者無顯著差異。攝入高 能量密度高脂配方,所需胃排空時間較低能量密度高蛋白配方長,但與低能量 密度高脂配方無顯著差異。不同配方對於受試者血漿GLP-1 濃度無顯著差 異。高能量密度高脂配方,所誘導的攝食產熱效應為10.4±0.7%,顯著低於低 能量密度高脂的14.9±1.2%及低能量密度高蛋白的18.1±1.1%。從上述結果, 推論增加能量密度會減緩胃排空及減少攝食產熱效應,但若同時含有高量脂 肪,則會覆蓋能量密度對於胃排空的影響。胃與代謝因子兩者相反的調控模 式,或許可以用於解釋,為何增加能量密度配方的攝入後對於後續總能量的攝 取並無影響。 Topics: Adolescent; Adult; Blood Glucose; Diet, High-Fat; Dietary Proteins; Energy Intake; Energy Metabolism; Gastric Emptying; Glucagon-Like Peptide 1; Humans; Insulin; Male; Middle Aged; Obesity; Overweight; Thermogenesis | 2013 |
Oral L-arginine stimulates GLP-1 secretion to improve glucose tolerance in male mice.
Pharmacological and surgical interventions that increase glucagon-like peptide 1 (GLP-1) action are effective to improve glucose homeostasis in type 2 diabetes mellitus. In light of this, nutritional strategies to enhance postprandial GLP-1 secretion, particularly in the context of diet-induced obesity, may provide an alternative therapeutic approach. Importantly, recent evidence suggests the amino acid L-arginine, a well-known insulin secretagogue, can also stimulate release of GLP-1 from isolated rat intestine. Here we tested the hypothesis that oral L-arginine acts as a GLP-1 secretagogue in vivo, to augment postprandial insulin secretion and improve glucose tolerance. To test this, we administered L-arginine or vehicle by oral gavage, immediately prior to an oral glucose tolerance test in lean and diet-induced obese mice. In both lean and obese mice oral L-arginine increased plasma GLP-1 and insulin and substantially improved glucose clearance. To directly assess the contribution of GLP-1 receptor (GLP-1R)-signaling to these improvements, L-arginine was given to Glp1r knockout mice and their wild-type littermates. In this experiment oral l-arginine significantly augmented insulin secretion and improved glucose clearance in WT mice, but not in Glp1r knockout littermates. Taken together these findings identify L-arginine as a GLP-1 secretagogue in vivo and demonstrate that improvement of glucose tolerance by oral L-arginine depends on GLP-1R-signaling. These findings raise the intriguing possibility that L-arginine-based nutritional and/or pharmaceutical therapies may benefit glucose tolerance by improving the postprandial GLP-1 response in obese individuals. Topics: Animals; Arginine; Dietary Fats; Gene Expression Regulation; Glucagon-Like Peptide 1; Glucagon-Like Peptide-1 Receptor; Glucose Intolerance; Glucose Tolerance Test; Insulin; Male; Mice; Mice, Inbred C57BL; Mice, Knockout; Obesity; Receptors, Glucagon | 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 |
Inter-relationships among diet, obesity and hippocampal-dependent cognitive function.
Intake of a Western diet (WD), which is high in saturated fat and sugar, is associated with deficits in hippocampal-dependent learning and memory processes as well as with markers of hippocampal pathology. In the present study, rats were trained to asymptote on hippocampal-dependent serial feature negative (FN) and hippocampal-independent simple discrimination problems. Performance was then assessed following 7 days on ad libitum chow and after 10, 24, 40, 60, and 90 days of maintenance on WD, on ketogenic (KETO) diet, which is high in saturated fat and low in sugar and other carbohydrates, or continued maintenance on chow (CHOW). Confirming and extending previous findings, diet-induced obese (DIO) rats fed WD showed impaired FN performance, increased blood-brain barrier (BBB) permeability, and increased fasting blood glucose levels compared to CHOW controls and to diet-resistant (DR) rats that did not become obese when maintained on WD. For rats fed the KETO diet, FN performance and BBB integrity were more closely associated with level of circulating ketone bodies than with obesity phenotype (DR or DIO), with higher levels of ketones appearing to provide a protective effect. The evidence also indicated that FN deficits preceded and predicted increased body weight and adiposity. This research (a) further substantiates previous findings of WD-induced deficits in hippocampal-dependent FN discriminations, (b) suggests that ketones may be protective against diet-induced cognitive impairment, and (c) provides evidence that diet-induced cognitive impairment precedes weight gain and obesity. Topics: 3-Hydroxybutyric Acid; Adiposity; Animals; Blood Glucose; Body Weight; Cognition; Conditioning, Classical; Diet, Ketogenic; Discrimination Learning; Enzyme-Linked Immunosorbent Assay; Fasting; Glucagon-Like Peptide 1; Hippocampus; Insulin; Male; Obesity; Rats; Rats, Sprague-Dawley; Time Factors; Triglycerides | 2013 |
Enhanced fasting and post-prandial plasma bile acid responses after Roux-en-Y gastric bypass surgery.
Exogenous bile acid (BA) administration is associated with beneficial metabolic effects very similar to those seen after Roux-en-Y gastric bypass (RYGB) surgery. Re-routing of bile into a biliopancreatic limb with simultaneous exclusion of food occurs after RYGB, with subsequent increased fasting plasma BAs. The study assessed fasting and post-prandial plasma BA response before and 15 months after RYGB.. The prospective study recruited 63 obese individuals (43 females), aged 43 (36-56) [median (IQR)] years. Blood samples were collected before and every 30 min for 120 min after a standard 400 kcal meal. Fasting and post-prandial plasma BAs, glucagons like peptide-1 (GLP-1), -tyrosine (PYY), fasting C-reactive protein (CRP), glucose and insulin were measured and homeostasis model assessment-insulin resistance (HOMA-IR) was calculated.. Following RYGB, body mass index, CRP, fasting glucose and HOMA-IR decreased; 43.7 (39.3-49.2) kg/m(2) to 29.2 (25.1-35.0) kg/m(2), 7.9 (4.1-11.9) mg/L to 0.4 (0.2-1.0) mg/L, 5.5 (5.0-6.0) mmol/L to 4.6 (4.3-4.9) mmol/L and 5.9 (3.5-9.2) to 1.7 (1.1-2.2), respectively, all P < 0.001. Fasting total BAs, GLP-1 and PYY increased after RYGB; 1.69 (0.70-2.56) µmol/L to 2.43 (1.23-3.82) µmol/L (P = 0.02), 6.8 (1.5-15.3) pmol/L to 17.1 (12.6-23.9) pmol/L (P < 0.001) and 4.0 (1.0-7.1) pmol/L to 15.2 (10.0-28.3) pmol/L (P < 0.001), respectively. The area under the curve for post-prandial total BAs, total glycine-conjugated BAs, GLP-1 and PYY were greater after RYGB; 486 (312-732) µmol/L/min versus 1012 (684-1921) µmol/L/min, 315 (221-466) µmol/L/min versus 686 (424-877) µmol/L/min, 3679 (3162-4537) pmol/L/min versus 5347 (4727-5781) pmol/L/min and 1887 (1423-2092) pmol/L/min versus 3296 (2534-3834) pmol/L/min, respectively, all P < 0.0001.. Weight loss following RYGB is associated with an increase in post-prandial plasma BA response due to larger amounts of glycine-conjugated BAs. This suggests up regulation of BA production and conjugation after RYGB. Topics: Adult; Bile; Blood Glucose; Body Mass Index; C-Reactive Protein; Cohort Studies; Fasting; Female; Gastric Bypass; Glucagon-Like Peptide 1; Humans; Insulin; Insulin Resistance; Male; Middle Aged; Obesity; Postprandial Period; Time Factors; Weight Loss | 2013 |
A novel glucagon-like peptide-1 (GLP-1)/glucagon hybrid peptide with triple-acting agonist activity at glucose-dependent insulinotropic polypeptide, GLP-1, and glucagon receptors and therapeutic potential in high fat-fed mice.
Glucagon-like peptide-1 (GLP-1), glucose-dependent insulinotropic polypeptide (GIP), and glucagon bind to related members of the same receptor superfamily and exert important effects on glucose homeostasis, insulin secretion, and energy regulation. The present study assessed the biological actions and therapeutic utility of novel GIP/glucagon/GLP-1 hybrid peptides. Nine novel peptides were synthesized and exhibited complete DPP-IV resistance and enhanced in vitro insulin secretion. The most promising peptide, [dA(2)]GLP-1/GcG, stimulated cAMP production in GIP, GLP-1, and glucagon receptor-transfected cells. Acute administration of [dA(2)]GLP-1/GcG in combination with glucose significantly lowered plasma glucose and increased plasma insulin in normal and obese diabetic (ob/ob) mice. Furthermore, [dA(2)]GLP-1/GcG elicited a protracted glucose-lowering and insulinotropic effect in high fat-fed mice. Twice daily administration of [dA(2)]GLP-1/GcG for 21 days decreased body weight and nonfasting plasma glucose and increased circulating plasma insulin concentrations in high fat-fed mice. Furthermore, [dA(2)]GLP-1/GcG significantly improved glucose tolerance and insulin sensitivity by day 21. Interestingly, locomotor activity was increased in [dA(2)]GLP-1/GcG mice, without appreciable changes in aspects of metabolic rate. Studies in knock-out mice confirmed the biological action of [dA(2)]GLP-1/GcG via multiple targets including GIP, GLP-1, and glucagon receptors. The data suggest significant promise for novel triple-acting hybrid peptides as therapeutic options for obesity and diabetes. Topics: Amino Acid Sequence; Animals; Blood Glucose; Cyclic AMP; Diet, High-Fat; Dipeptidyl Peptidase 4; Glucagon; Glucagon-Like Peptide 1; Glucagon-Like Peptide-1 Receptor; Insulin; Insulin Resistance; Insulin Secretion; Male; Mice; Mice, Inbred C57BL; Mice, Knockout; Mice, Obese; Molecular Sequence Data; Obesity; Receptors, Gastrointestinal Hormone; Receptors, Glucagon; Recombinant Fusion Proteins | 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 |
Liraglutide improves hippocampal synaptic plasticity associated with increased expression of Mash1 in ob/ob mice.
Consumption of high-fat diet exerts adverse effects on learning and memory formation, which is linked to impaired hippocampal function. Activation of glucagon-like peptide-1 (GLP-1) signalling ameliorates detrimental effects of obesity-diabetes on cognitive function; however, mechanisms underlying these beneficial actions remain unclear. This study examined effects of daily subcutaneous treatment with GLP-1 mimetic, Liraglutide, on synaptic plasticity, hippocampal gene expression and metabolic control in adult obese diabetic (ob/ob) mice.. Long-term potentiation (LTP) induced by area CA1 was completely abolished in ob/ob mice compared with lean controls. Deleterious effects on LTP were rescued (P<0.001) with Liraglutide. Indeed, Liraglutide-treated mice exhibited superior LTP profile compared with lean controls (P<0.01). Expression of hippocampal brain-derived neurotropic factor and neurotrophic tyrosine kinase receptor-type 2 were not significantly different, but synaptophysin and Mash1 were decreased in ob/ob mice. Treatment with Liraglutide over 21 days increased expression of Mash1 in ob/ob mice (2.0-fold; P<0.01). These changes were associated with significantly reduced plasma glucose (21% reduction; P<0.05) and markedly improved plasma insulin concentrations (2.1- to 3.3-fold; P<0.05 to P<0.01). Liraglutide also significantly reduced the glycaemic excursion following an intraperitonal glucose load (area under curve (AUC) values: 22%; P<0.05) and markedly enhanced the insulin response to glucose (AUC values: 1.6-fold; P<0.05). O2 consumption, CO2 production, respiratory exchange ratio and energy expenditure were not altered by Liraglutide therapy. On day 21, accumulated food intake (32% reduction; P<0.05) and number of feeding bouts (32% reduction; P<0.05) were significantly reduced but simple energy restriction was not responsible for the beneficial actions of Liraglutide.. Liraglutide elicits beneficial effects on metabolic control and synaptic plasticity in mice with severe obesity and insulin resistance mediated in part through increased expression of Mash1 believed to improve hippocampal neurogenesis and cell survival. Topics: Animals; Basic Helix-Loop-Helix Transcription Factors; Blood Glucose; Brain-Derived Neurotrophic Factor; Diet, High-Fat; Glucagon-Like Peptide 1; Glucose; Hippocampus; Hypoglycemic Agents; Infusions, Subcutaneous; Insulin; Insulin Resistance; Liraglutide; Male; Membrane Glycoproteins; Mice; Neuronal Plasticity; Obesity; Protein-Tyrosine Kinases; Signal Transduction | 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 |
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 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 |
A glucagon-like peptide-1 analog reverses the molecular pathology and cardiac dysfunction of a mouse model of obesity.
Cardiac consequences of obesity include inflammation, hypertrophy, and compromised energy metabolism. Glucagon-like peptide-1 is an incretin hormone capable of cytoprotective actions that reduces inflammation and endoplasmic reticulum stress in other tissues. Here we examine the cardiac effects of the glucagon-like peptide-1 analog liraglutide in a model of obesity, independent of changes in body weight.. C57Bl6 mice were placed on a 45% high-fat diet (HFD) or a regular chow diet. Mice on HFD developed 46±2% and 60±2% greater body weight relative to regular chow diet-fed mice at 16 and 32 weeks, respectively (both P<0.0001), manifesting impaired glucose tolerance, insulin resistance, and cardiac ceramide accumulation by 16 weeks. One-week treatment with liraglutide (30 µg/kg twice daily) did not reduce body weight, but reversed insulin resistance, cardiac tumor necrosis factor-α expression, nuclear factor kappa B translocation, obesity-induced perturbations in cardiac endothelial nitric oxide synthase, connexin-43, and markers of hypertrophy and fibrosis, in comparison with placebo-treated HFD controls. Liraglutide improved the cardiac endoplasmic reticulum stress response and also improved cardiac function in animals on HFD by an AMP-activated protein kinase-dependent mechanism. Supporting a direct mechanism of action, liraglutide (100 nmol/L) prevented palmitate-induced lipotoxicity in isolated mouse cardiomyocytes and primary human coronary smooth muscle cells and prevented adhesion of human monocytes to tumor necrosis factor-α-activated human endothelial cells in vitro.. Weight-neutral treatment with a glucagon-like peptide-1 analog activates several cardioprotective pathways, prevents HFD-induced insulin resistance and inflammation, reduces monocyte vascular adhesion, and improves cardiac function in vivo by activating AMP-activated protein kinase. These data support a role for glucagon-like peptide-1 analogs in limiting the cardiovascular risks of obesity. Topics: Animals; Blood Glucose; Cardiotonic Agents; Cell Line; Connexin 43; Coronary Vessels; Disease Models, Animal; Endoplasmic Reticulum Stress; Endothelial Cells; Gene Expression; Glucagon-Like Peptide 1; Heart Diseases; Humans; Hypercholesterolemia; Insulin Resistance; Liraglutide; Mice; Mice, Inbred C57BL; Monocytes; Muscle, Smooth, Vascular; Myocytes, Cardiac; Nitric Oxide Synthase Type III; Obesity; Risk Factors; Signal Transduction; Tumor Necrosis Factor-alpha | 2013 |
Anorexigenic postprandial responses of PYY and GLP1 to slow ice cream consumption: preservation in obese adolescents, but not in obese adults.
Eating slowly increases the postprandial responses of some anorexigenic gut hormones in healthy lean subjects. As the rate of food intake is positively associated with obesity, the aim of the study was to determine whether eating the same meal at different rates evokes different postprandial anorexigenic responses in obese adolescent and adult subjects.. Eighteen obese adolescents and adults were enrolled. A test meal was consumed on two different sessions by each subject, meal duration taking either 5 min (fast feeding) or 30 min (slow feeding). Circulating levels of glucagon-like peptide 1 (GLP1), peptide YY (PYY), glucose, insulin, and triglycerides were measured over 210 min. Visual analog scales were used to evaluate the subjective feelings of hunger and satiety.. fast feeding did not stimulate GLP1 release in obese adolescent and adults, whereas slow feeding increased circulating levels of GLP1 only in obese adolescents. Plasma PYY concentrations increased both in obese adolescents and in adults, irrespective of the eating rate, but slow feeding was more effective in stimulating PYY release in obese adolescents than in adults. simultaneously, slow feeding evoked a higher satiety only in obese adolescents compared with fast feeding but not in obese adults. in obese adolescents, slow feeding decreased hunger (only at 210 min). irrespective of the eating rate, postprandial responses of insulin and triglycerides were higher in obese adults than in obese adolescents.. Slow feeding leads to higher concentrations of anorexigenic gut peptides and favors satiety in obese adolescents, but this physiological control of food intake is lost in obese adults. Topics: Adolescent; Adolescent Behavior; Adolescent Development; Adult; Aging; Body Mass Index; Feeding Behavior; Female; Glucagon-Like Peptide 1; Humans; Ice Cream; Intestinal Mucosa; Italy; Male; Obesity; Peptide YY; Postprandial Period; Reproducibility of Results; Satiety Response; Time Factors | 2013 |
Beneficial effects of (pGlu-Gln)-CCK-8 on energy intake and metabolism in high fat fed mice are associated with alterations of hypothalamic gene expression.
Cholecystokinin (CCK) is a gastrointestinal hormone with potential therapeutic promise for obesity-diabetes. The present study examined the effects of twice daily administration of the N-terminally modified stable CCK-8 analogue, (pGlu-Gln)-CCK-8, on metabolic control and hypothalamic gene expression in high fat fed mice. Sub-chronic twice daily injection of (pGlu-Gln)-CCK-8 for 16 days significantly decreased body weight (p<0.05), energy intake (p<0.01), circulating blood glucose (p<0.001), and plasma insulin (p<0.001) compared to high fat controls. Furthermore, (pGlu-Gln)-CCK-8 markedly improved glucose tolerance (p<0.05) and insulin sensitivity (p<0.05). Assessment of hypothalamic gene expression on day 16 revealed significantly elevated NPY (p<0.05) and reduced POMC (p<0.05) and MC4R (p<0.05) mRNA expression in (pGlu-Gln)-CCK-8 treated mice. High fat feeding or (pGlu-Gln)-CCK-8 treatment had no significant effects on hypothalamic gene expression of receptors for leptin, CCK₁ and GLP-1. These studies underscore the potential of (pGlu-Gln)-CCK-8 for the treatment of obesity-diabetes and suggest modulation of NPY and melanocortin related pathways may be involved in the observed beneficial effects. Topics: Animals; Blood Glucose; Cholecystokinin; Diet, High-Fat; Energy Intake; Gene Expression Regulation; Glucagon-Like Peptide 1; Humans; Hypothalamus; Insulin; Leptin; Male; Mice; Obesity; Peptide Fragments; Peptides; Pro-Opiomelanocortin; Receptor, Melanocortin, Type 4 | 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 |
Pharmacotherapy: disparate bedfellows in a lasting drug union?
Topics: Animals; Diet; Drug Combinations; Drug Therapy, Combination; Estradiol; Glucagon-Like Peptide 1; Humans; Metabolic Syndrome; Mice; Obesity; Weight Loss | 2013 |
Validation of Ussing chamber technology to study satiety hormone release from human duodenal specimens.
By developing novel screening technologies to test effects of food ingredients on hormone release, which are comparable to the in vivo situation, fewer tests may have to be performed using volunteers, whereas it still provides information that can be extrapolated to the human situation. In an in vivo intervention study, 10 lean (BMI: 20-25 kg/m(2)) and 10 obese (BMI >30 kg/m(2)) were recruited. All subjects randomly received pea protein (PP) solutions or placebo, orally and intraduodenally. Cholecystokinin (CCK) and glucagon like peptide 1 (GLP-1) release was measured over 2 h. During the oral interventions, gastrointestinal (GI) fluids were retrieved. For the present ex vivo study, duodenal biopsies were taken and placed in Ussing chambers. The luminal side was exposed to PP, placebo, intraduodenal fluid after oral PP-intake and oral placebo-intake in vivo, and a commercial pea-hydrolysate for 2 h. CCK and GLP-1 levels were measured at the serosal side. After intraduodenal PP administration in vivo, the area under the curve (AUC) for both CCK and GLP-1 was significantly increased in both lean and obese subjects. In the ex vivo study, exposure to PP resulted in significantly elevated levels of CCK and GLP-1 compared to all other test solutions. These results indicate that the ex vivo Ussing chamber technology is a valid alternative for in vivo studies, and may therefore serve as a suitable screening tool for studying the effects of nutritional compounds on the release of satiety hormones. Topics: Administration, Oral; Adult; Biopsy; Cholecystokinin; Diffusion Chambers, Culture; Duodenum; Female; Glucagon-Like Peptide 1; Humans; Intestinal Mucosa; Male; Obesity; Pisum sativum; Plant Proteins; Satiety Response | 2012 |
Exogenous peptide YY3-36 and Exendin-4 further decrease food intake, whereas octreotide increases food intake in rats after Roux-en-Y gastric bypass.
Patients show an elevated postprandial satiety gut hormone release after Roux-en-Y Gastric bypass (gastric bypass). The altered gut hormone response appears to have a prominent role in the reduction of appetite and body weight (BW) after gastric bypass. Patients with insufficient BW loss after gastric bypass have an attenuated postprandial gut hormone response in comparison with patients who lost an adequate amount of BW. The effects of additional gut hormone administration after gastric bypass are unknown.. The effects of peripheral administration of peptide YY3-36 (PYY3-36; 300 nmol kg(-1)), glucagon-like peptide-1 (GLP-1) analogue Exendin-4 (20 nmol kg(-1)) and somatostatin analogue octreotide (10 μg kg(-1)) on feeding and BW were evaluated in rats after gastric bypass.. Gastric bypass rats weighed (P<0.01) and ate less on postoperative day 5 (P<0.001) and thereafter, whereas postprandial plasma PYY and GLP-1 levels were higher compared with sham-operated controls (P<0.001). Administration of both PYY3-36 and Exendin-4 led to a further decrease in food intake in bypass rats compared with saline treatment (P=0.02 and P<0.0001, respectively). Similar reduction in food intake was observed in sham rats (P=0.02 and P<0.001, respectively). Exendin-4 treatment resulted in a significant BW loss in bypass (P=0.03) and sham rats (P=0.04). Subsequent treatment with octreotide led to an increase in food intake in bypass (P=0.007), but not in sham rats (P=0.87).. Peripheral administration of PYY3-36 and Exendin-4 reduces short-term food intake, whereas octreotide increases short-term food intake in rats after gastric bypass. The endogenous gut hormone response after gastric bypass can thus potentially be further enhanced by additional exogenous therapy with pharmacological doses of gut hormones in patients with insufficient weight loss or weight regain after surgery. Topics: Animals; Appetite Depressants; Appetite Regulation; Appetite Stimulants; Eating; Exenatide; Gastric Bypass; Glucagon-Like Peptide 1; Hypoglycemic Agents; Obesity; Octreotide; Peptide Fragments; Peptide YY; Peptides; Postoperative Period; Rats; Satiation; Venoms | 2012 |
Acute satiety response of mammalian, avian and fish proteins in dogs.
Fish proteins have been reported to be more satiating than meat proteins. The objective was to determine the effect of different animal protein pre-meals on satiety. A total of ten intact female hounds were fed pork loin, beef loin, chicken breast, salmon fillet or pollock fillet. Each pre-meal was fed to contain 100 g protein. Blood was collected at 0, 5, 15, 30, 60, 90 and 120 min postprandially and analysed for glucose, insulin, total ghrelin, active glucagon-like peptide-1 (GLP-1) and plasma amino acids (AA). Dogs were fed 2 × metabolisable energy, 3 h following the pre-meal, and intake was determined 30, 60, 180 and 1440 min after food presentation. Glucose decreased over time (P < 0·001), but was lowest (P = 0·01) when dogs consumed pollock or chicken. Insulin increased (P < 0·0001) over time, and was greater (P = 0·09) when dogs consumed salmon. GLP-1 increased (P < 0·001) over time, and was greatest (P = 0·04) when dogs consumed beef. Ghrelin decreased (P < 0·0001) over time for all pre-meals. The tryptophan:large neutral AA ratio tended to be greater (P = 0·08) when dogs consumed pork, salmon and pollock. Different protein sources may influence blood markers in dogs, but it does not appear that fish substrates have different satiating abilities than mammalian or avian sources. Topics: Amino Acids; Animals; Avian Proteins; Biomarkers; Blood Glucose; Dietary Proteins; Dogs; Female; Fish Proteins; Fishes; Ghrelin; Glucagon-Like Peptide 1; Insulin; Meat; Muscle, Skeletal; Obesity; Random Allocation; Satiety Response; Seafood; Time Factors | 2012 |
Prebiotic fibres dose-dependently increase satiety hormones and alter Bacteroidetes and Firmicutes in lean and obese JCR:LA-cp rats.
There is a growing interest in modulating gut microbiota with diet in the context of obesity. The purpose of the present study was to evaluate the dose-dependent effects of prebiotics (inulin and oligofructose) on gut satiety hormones, energy expenditure, gastric emptying and gut microbiota. Male lean and obese JCR:LA-cp rats were randomised to either of the following: lean 0 % fibre (LC), lean 10 % fibre (LF), lean 20 % fibre (LHF), obese 0 % fibre (OC), obese 10 % fibre (OF) or obese 20 % fibre (OHF). Body composition, gastric emptying, energy expenditure, plasma satiety hormone concentrations and gut microbiota (using quantitative PCR) were measured. Caecal proglucagon and peptide YY mRNA levels were up-regulated 2-fold in the LF, OF and OHF groups and 3-fold in the LHF group. Ghrelin O-acyltransferase mRNA levels were higher in obese v. lean rats and decreased in the OHF group. Plasma ghrelin response was attenuated in the LHF group. Microbial species measured in the Bacteroidetes division decreased, whereas those in the Firmicutes increased in obese v. lean rats and improved with prebiotic intake. Bifidobacterium and Lactobacillus increased in the OHF v. OC group. Bacteroides and total bacteria negatively correlated with percentage of body fat and body weight. Enterobacteriaceae increased in conjunction with glucose area under the curve (AUC) and glucagon-like peptide-1 AUC. Bacteroides and total bacteria correlated positively with ghrelin AUC yet negatively with insulin AUC and energy intake (P < 0·05). Several of the mechanisms through which prebiotics act (food intake, satiety hormones and alterations in gut microbiota) are regulated in a dose-dependent manner. The combined effects of prebiotics may have therapeutic potential for obesity. Topics: Acyltransferases; Animals; Bacteroidetes; Disease Models, Animal; Gastrointestinal Tract; Gene Expression Regulation; Ghrelin; Glucagon-Like Peptide 1; Gram-Negative Bacteria; Gram-Positive Bacteria; Inulin; Male; Obesity; Oligosaccharides; Peptide YY; Prebiotics; Proglucagon; Random Allocation; Rats; Rats, Inbred Strains; RNA, Messenger; Satiety Response | 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 |
Glucagon-like peptide-1 regulation of carbohydrate intake is differentially affected by obesogenic diets.
The incretin hormone glucagon-like peptide-1 (GLP-1) has been implicated in the regulation of appetite by acting as an anorexigenic gut-brain signal. The postprandial release of GLP-1 can be blunted in obese humans and animals. However, it remains unknown whether obesogenic diets with varying fat and carbohydrate content may differentially influence the effectiveness of GLP-1 feedback. To investigate this, male Sprague-Dawley rats were fed a standard (low fat) chow diet, or one of two high-energy diets varying in fat content (45 or 60 kcal%) for 28 weeks. Intake of sucrose and fructose solutions, two commonly added sugars in the Western diet, was then tested in nondeprived rats following administration of the GLP-1 receptor agonist, Exendin-4 (0, 0.5, 1, 2, 3 µg/kg; s.c.). Exendin-4 dose-dependently reduced short (2 h) sucrose and fructose intake. This effect was significantly attenuated in rats fed more dietary fat, despite both diets resulting in obesity. These findings demonstrate that intake of carbohydrates when offered as treats can be regulated by GLP-1 and suggests that dietary fat consumption, rather than extra calories or obesity, may lead to impaired GLP-1 feedback to curb carbohydrate intake. Future studies are warranted to investigate the relevance of these observations to humans and to elucidate the underlying mechanisms. Topics: Analysis of Variance; Animals; Appetite Regulation; Body Weight; Dietary Fats; Dietary Sucrose; Dose-Response Relationship, Drug; Exenatide; Fructose; Glucagon-Like Peptide 1; Hypoglycemic Agents; Male; Obesity; Peptides; Rats; Rats, Sprague-Dawley; Venoms | 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 |
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 |
Prebiotic fiber increases hepatic acetyl CoA carboxylase phosphorylation and suppresses glucose-dependent insulinotropic polypeptide secretion more effectively when used with metformin in obese rats.
Independently, metformin (MET) and the prebiotic, oligofructose (OFS), have been shown to increase glucagon-like peptide (GLP-1) secretion. Our objective was to determine whether using OFS as an adjunct with MET augments GLP-1 secretion in obese rats. Male, diet-induced obese Sprague Dawley rats were randomized to: 1) high-fat/-sucrose diet [HFHS; control (C); 20% fat, 50% sucrose wt:wt]; 2) HFHS+10% OFS (OFS); 3) HFHS + MET [300 mg/kg/d (MET)]; 4) HFHS+10% OFS+MET (OFS+MET). Body composition, glycemia, satiety hormones, and mechanisms related to dipeptidyl peptidase 4 (DPP4) activity in plasma, hepatic AMP-activated protein kinase (AMPK; Western blots), and gut microbiota (qPCR) were examined. Direct effects of MET and SCFA were examined in human enteroendocrine cells. The interaction between OFS and MET affected fat mass, hepatic TG, secretion of glucose-dependent insulinotropic polypeptide (GIP) and leptin, and AMPKα2 mRNA and phosphorylated acetyl CoA carboxylase (pACC) levels (P < 0.05). Combined, OFS and MET reduced GIP secretion to a greater extent than either treatment alone (P < 0.05). The hepatic pACC level was increased by OFS+MET by at least 50% above all other treatments, which did not differ from each other (P < 0.05). OFS decreased plasma DPP4 activity (P < 0.001). Cecal Bifidobacteria (P < 0.001) were markedly increased and C. leptum decreased (P < 0.001) with OFS consumption. In human enteroendocrine cells, the interaction between MET and SCFA affected GLP-1 secretion (P < 0.04) but was not associated with higher GLP-1 than the highest individual doses. In conclusion, the combined actions of OFS and MET were associated with important interaction effects that have the potential to improve metabolic outcomes associated with obesity. Topics: Acetyl-CoA Carboxylase; Adenylate Kinase; Animals; Blood Glucose; Body Composition; Dietary Fiber; Dipeptidyl Peptidase 4; Eating; Gastric Inhibitory Polypeptide; Gastrointestinal Tract; Glucagon-Like Peptide 1; Humans; Hypoglycemic Agents; Insulin; Liver; Male; Metformin; Obesity; Oligosaccharides; Phosphorylation; Prebiotics; Random Allocation; Rats; Rats, Sprague-Dawley | 2012 |
Liraglutide: short-lived effect on gastric emptying -- long lasting effects on body weight.
Previous studies with the novel once daily glucagon-like peptide-1 (GLP-1) analogue liraglutide and the GLP-1 receptor agonist exenatide have revealed profound insulinotrophic and antidiabetic effects, but also potent effects on gastric emptying (GE) and long-term and lasting reductions in body weight. In this study, we examined the acute and chronic effects of two different GLP-1 analogues with different pharmacokinetic profiles on GE, food intake and body weight.. On the basis of a series of dose-finding studies, the doses of exenatide and liraglutide with similar acute anorectic effects were identified. GE was assessed using a standard acetaminophen release assay. After the acute test, rats were dosed bi-daily for 14 days in which period food intake and body weight was monitored. On day 14, the GE rate was reassessed.. While both compounds exerted robust acute reductions in GE, the effect was markedly diminished following 14 days of dosing with liraglutide. In contrast, exenatide-treated rats still displayed a profound reduction in GE at the 14-day time-point. Both compounds exerted similar effects on body weight.. The data suggest that the 'gastric inhibitory' GLP-1 receptors in rats are subject to desensitization/tachyphylaxis but that this effect is dependent on full 24-h exposure as obtained by liraglutide. The body weight-lowering effects of GLP-1 receptor stimulation are not subject to desensitization. These data indicate that regulation of appetite signals in the brain, and not GE, is the main mechanism for liraglutide-induced weight loss. Topics: Animals; Appetite Regulation; Eating; Exenatide; Gastric Emptying; Glucagon-Like Peptide 1; Hippocampus; Injections, Intravenous; Liraglutide; Male; Obesity; Peptides; Rats; Rats, Sprague-Dawley; Venoms; Weight Loss | 2012 |
Breakfast skipping in prepubertal obese children: hormonal, metabolic and cognitive consequences.
Skipping breakfast influences cognitive performance. The aim of our study was to investigate the relationship between the variation of hormonal and metabolic postprandial parameters induced by breakfast consumption or fasting and cognitive performance in obese children.. Cross-sectional study for repeated measures. Memory and attention assessment tests, hormones and nutrient oxidation were measured before and after consuming breakfast vs fasting in 10 prepubertal obese children.. Fasting induced a significant (P<0.05) increase of the Overall Index of the Continuous Performance Test II (a global index of inattention) and the Test of Memory and Learning Word Selective Reminding (a test of verbal memory), whereas no changes were found after breakfast. Fasting was associated with a reduction of insulin and an increase in glucagon, with no changes in glucose. The increase in inattention was associated with a reduction of carbohydrate oxidation (ρ=-0.66, P<0.05). We found no difference in the area under the curve of peptide YY and glucagon-like peptide-1 after breakfast or fasting, whereas Ghrelin was significantly lower. No association between postprandial hormone variation and cognitive performance was found.. Attention and visual memory performance in the morning were reduced when the children skipped breakfast. No association was found with hormones or metabolic changes, but we did find an association with a reduction of carbohydrate oxidation. Nevertheless, these preliminary findings need confirmation in larger sample size. Topics: Area Under Curve; Attention; Blood Glucose; Carbohydrate Metabolism; Child; Cognition; Cross-Sectional Studies; Diet; Fasting; Feeding Behavior; Ghrelin; Glucagon; Glucagon-Like Peptide 1; Humans; Insulin; Memory; Obesity; Oxidation-Reduction; Peptide YY; Postprandial Period; Verbal Learning | 2012 |
Effects of liraglutide and sibutramine on food intake, palatability, body weight and glucose tolerance in the gubra DIO-rats.
To validate the gubra DIO-rats as a useful animal model of human obesity.. The gubra diet-induced obesity (DIO) rat model was based on male Sprague-Dawley rats with ad libitum access to regular chow and a palatable diet rich in fat and sugar. To evaluate the versatility of the gubra DIO-rats as a valid model of human obesity syndrome, the efficacy of 2 weight loss compounds liraglutide and sibutramine with different mechanisms of action were examined in 7-month-old gubra DIO-rats. Liraglutide (200 μg/kg, sc) was administered bi-daily, and sibutramine (5 mg/kg, po) was administered once daily for 23 d.. Both the compounds effectively reduced the food intake, body weight and total fat mass as measured by nuclear magnetic resonance. Whereas the 5-HT reuptake inhibitor/5-HT receptor agonist sibutramine reduced the intake of both chow and the gubra-diet, the GLP-1 analogue liraglutide predominantly reduced the intake of the highly palatable diet, indicating a shift in food preference. Sibutramine lowered the insulin sensitivity index, primarily via reductions in glucose-stimulated insulin secretion.. This animal model responds well to 2 weight loss compounds with different mechanisms of action. Moreover, the gubra DIO-rat can be particularly useful for the testing of compounds with potential effects on diet preference. Topics: Animals; Anti-Obesity Agents; Body Weight; Cyclobutanes; Eating; Glucagon-Like Peptide 1; Glucose Tolerance Test; Insulin Resistance; Liraglutide; Male; Obesity; Rats; Rats, Sprague-Dawley | 2012 |
A synergy between incretin effect and intestinal gluconeogenesis accounting for the rapid metabolic benefits of gastric bypass surgery.
The early improvement of glucose control taking place shortly after gastric bypass surgery in obese diabetic patients has long been mysterious. A recent study in mice has highlighted some specific mechanisms underlying this phenomenon. The specificity of gastric bypass in obese diabetic mice relates to major changes in the sensations of hunger and to rapid improvement of glucose parameters. The induction of intestinal gluconeogenesis plays a major role in diminishing hunger, and in restoring insulin sensitivity of endogenous glucose production. In parallel, the restoration of the secretion of glucagon-like peptide 1 and insulin plays a key additional role, in this context of recovered insulin sensitivity, to improve postprandial glucose tolerance. Therefore, a synergy between an incretin effect and intestinal gluconeogenesis is a key feature accounting for the rapid improvement of glucose control in obese diabetic patients after bypass surgery. Topics: Animals; Blood Glucose; Gastric Bypass; Gastric Inhibitory Polypeptide; Gastroplasty; Glucagon-Like Peptide 1; Gluconeogenesis; Incretins; Insulin Resistance; Mice; Mice, Obese; Obesity | 2012 |
Effects of ileal interposition on glucose metabolism in obese rats with diabetes.
Ileal interposition (IT), in which the distal ileum is transposed isoperistaltically into the proximal jejunum, is considered as a procedure for metabolic or antidiabetes surgery. Our aim was to study the effects of IT on glycemic control, fat metabolism, and hormonal changes in obese rats with spontaneous diabetes.. Animals were divided into either an IT or a sham (SH) group. They underwent an oral glucose tolerance test (OGTT) before and 4 and 8 weeks after the operation. All animals were killed 10 weeks after operation for analyses of tissue weight (liver, pancreas, epididymal fat, brown fat), immunoblotting of uncoupling protein-1 (UCP1) protein in brown adipose tissue (BAT), and fasting plasma levels of glucose, insulin, glucagon-like peptide (GLP)-1, peptide YY (PYY), glucose-dependent insulinotropic polypeptide (GIP), and leptin.. Body weight increased postoperatively in both groups compared with preoperative weight, but it did not differ between the 2 groups. Eight weeks postoperatively, integrated blood glucose levels during the OGTT were decreased in IT compared with SH (P < .05). Fasting plasma levels of insulin, GLP-1, and GIP did not differ between the 2 groups, but PYY levels were higher in the IT animals (P < .01). The weight of epididymal and BATs, homeostasis model assessment insulin resistance, and fasting plasma leptin levels were decreased in the IT group (P < .05). Expression of UCP1 was higher in IT than SH animals (P < .05).. These results suggest that IT improves glucose and lipid metabolism by decreasing insulin resistance and epididymal fat, and increased expression of UCP1 in BAT might be among the mechanisms responsible. Topics: Adipose Tissue, Brown; Animals; Body Weight; Comorbidity; Diabetes Mellitus; Disease Models, Animal; Gastric Inhibitory Polypeptide; Glucagon-Like Peptide 1; Glucose; Ileum; Insulin Resistance; Ion Channels; Jejunum; Leptin; Lipid Metabolism; Male; Mitochondrial Proteins; Obesity; Peptide YY; Rats, Inbred OLETF; Uncoupling Protein 1 | 2012 |
Dysfunction of lipid sensor GPR120 leads to obesity in both mouse and human.
Free fatty acids provide an important energy source as nutrients, and act as signalling molecules in various cellular processes. Several G-protein-coupled receptors have been identified as free-fatty-acid receptors important in physiology as well as in several diseases. GPR120 (also known as O3FAR1) functions as a receptor for unsaturated long-chain free fatty acids and has a critical role in various physiological homeostasis mechanisms such as adipogenesis, regulation of appetite and food preference. Here we show that GPR120-deficient mice fed a high-fat diet develop obesity, glucose intolerance and fatty liver with decreased adipocyte differentiation and lipogenesis and enhanced hepatic lipogenesis. Insulin resistance in such mice is associated with reduced insulin signalling and enhanced inflammation in adipose tissue. In human, we show that GPR120 expression in adipose tissue is significantly higher in obese individuals than in lean controls. GPR120 exon sequencing in obese subjects reveals a deleterious non-synonymous mutation (p.R270H) that inhibits GPR120 signalling activity. Furthermore, the p.R270H variant increases the risk of obesity in European populations. Overall, this study demonstrates that the lipid sensor GPR120 has a key role in sensing dietary fat and, therefore, in the control of energy balance in both humans and rodents. Topics: Adipocytes; Adipogenesis; Adipose Tissue; Animals; Calcium Signaling; Cell Differentiation; Diet, High-Fat; DNA Mutational Analysis; Energy Metabolism; Europe; Exons; Fatty Liver; Gene Expression Regulation; Glucagon-Like Peptide 1; Glucose; Glucose Intolerance; Humans; Insulin; Insulin Resistance; Lipogenesis; Liver; Macrophages; Mice; Mutation; Obesity; Receptors, G-Protein-Coupled; Signal Transduction; White People | 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 |
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 |
Gastric bypass surgery attenuates ethanol consumption in ethanol-preferring rats.
Roux-en-Y gastric bypass (RYGB) surgery is an effective weight loss strategy employed to treat obesity and associated complications. Importantly, the RYGB procedure has been reported to attenuate reward-related consummatory behaviors. The present work examined the hypothesis that RYGB surgery attenuates ethanol intake and reward in the context of frequent ethanol consumption.. To do this, self-report of ethanol intake was examined in human bariatric patients (n = 6165) before and following the RYGB procedure. In addition, we utilized a rodent model of RYGB and examined ethanol consumption and ethanol reward in male ethanol-preferring (P) rats, which are selectively bred to consume large volumes of ethanol.. Patients that reported frequent consumption of ethanol before RYGB reported decreased consumption following RYGB surgery. Moreover, the RYGB procedure decreased ethanol intake and the reinforcing properties of ethanol in P rats. Notably, the attenuating effect of RYGB surgery on ethanol consumption was associated with ethanol-induced increases in the gut hormone glucagon-like peptide-1 (GLP-1). Pharmacologic administration of GLP-1 agonists attenuated ethanol consumption in sham P rats. In addition, pharmacologic replacement of the gut hormone ghrelin restored drinking behavior in P rats following RYGB.. Collectively, these findings unveil the potential of RYGB surgery to attenuate ethanol consumption in some humans and rats. Furthermore, our data indicate that this regulation is achieved, in part, through reduction of reward and is modified by the gut hormones GLP-1 and ghrelin. Topics: Alcohol Drinking; Analysis of Variance; Animals; Ethanol; Gastric Bypass; Ghrelin; Glucagon-Like Peptide 1; Humans; Male; Models, Animal; Obesity; Prospective Studies; Rats; Rats, Inbred Strains; Weight Loss | 2012 |
Food intake in lean and obese mice after peripheral administration of glucagon-like peptide 2.
We investigated the potential anorectic action of peripherally administered glucagon-like peptide 2 (GLP2) in lean and diet-induced obese (DIO) mice. Mice, fasted for 16 h, were injected i.p. with native GLP2 or [Gly2]GLP2, stable analog of GLP2, before or after GLP2 (3-33), a GLP2 receptor (GLP2R) antagonist, or exendin (9-39), a GLP1R antagonist. Food intake was measured at intervals 1, 2, 4, 8, and 24 h postinjection. In addition, we tested in lean mice the influence of [Gly2]GLP2 on gastric emptying and the effects of GLP1 alone or in combination with [Gly2]GLP2 on food intake. [Gly2]GLP2 dose dependently and significantly inhibited food intake in lean and DIO mice. The reduction of food intake occurred in the first hour postinjection and it was sustained until 4 h postinjection in lean mice while it was sustained until 2 h postinjection in DIO mice. GLP2 significantly inhibited food intake in both lean and DIO mice but only in the first hour postinjection. The efficiency of [Gly2]GLP2 or GLP2 in suppressing food intake was significantly weaker in DIO mice compared with lean animals. The [Gly2]GLP2 anorectic actions were blocked by the GLP2R antagonist GLP2 (3-33) or by the GLP1R antagonist exendin (9-39). The coadministration of [Gly2]GLP2 and GLP1 did not cause additive effects. [Gly2]GLP2 decreased the gastric emptying rate. Results suggest that GLP2 can reduce food intake in mice in the short term, likely acting at a peripheral level. DIO mice are less sensitive to the anorectic effect of the peptide. Topics: Animals; Appetite Depressants; Diet, High-Fat; Dose-Response Relationship, Drug; Eating; Gastric Emptying; Glucagon-Like Peptide 1; Glucagon-Like Peptide 2; Glucagon-Like Peptide-1 Receptor; Glucagon-Like Peptide-2 Receptor; Male; Mice; Mice, Inbred C57BL; Obesity; Peptide Fragments; Receptor Cross-Talk; Receptors, Glucagon; Time Factors | 2012 |
Response of gut hormones after implantation of a reversible gastric restrictive device in different animal models.
Variable responses of gut hormones have been observed after bariatric procedures. The aim of the present study was to evaluate the ghrelin, glucagon-like peptide 1 (GLP-1), and leptin levels in nonobese canine and obese rat models after weight loss owing to a reversible gastric restriction (RGR) device.. Mongrel dogs and obese Zucker rats were submitted to either surgical implantation or a sham operation and were followed up for 6 wk. The serum fasting ghrelin, GLP-1, and leptin levels in dogs were measured using enzyme-linked immunosorbent assay before and after surgical implantation and after implant removal. The protein expression of mucosa ghrelin, GLP-1, and leptin in the dog and rat stomach were measured using Western blotting.. The RGR implant in dogs and rats resulted in a significant decrease in food intake and body weight. In the nonobese dog, the serum ghrelin level and mucosa ghrelin expression were significantly increased after surgical implantation (P < 0.05) and tended to recover after implant removal. In the obese rat, mucosa ghrelin expression decreased by about 27% (P = 0.06) 6 wk after implantation. A lower serum leptin level in dogs and lower mucosa leptin expression in dogs and rats was observed after surgical implantation compared with the sham procedure (P < 0.05). The RGR implant had no influence on the serum GLP-1 level in dogs or mucosa GLP-1 expression in either animal model.. Our results showed that ghrelin levels are downregulated with short-term RGR implantation in obese rats but upregulated in nonobese dogs, implying that the energy balance could be an important determinant of ghrelin level. The marked suppression of leptin in both animal models might contribute to the weight-reducing effect of the RGR implant. Topics: Animals; Body Weight; Disease Models, Animal; Dogs; Energy Metabolism; Gastric Mucosa; Gastroplasty; Ghrelin; Glucagon-Like Peptide 1; Leptin; Obesity; Rats; Rats, Zucker; Weight Loss | 2012 |
Actions of incretin metabolites on locomotor activity, cognitive function and in vivo hippocampal synaptic plasticity in high fat fed mice.
The incretin hormones glucagon-like peptide-1 (GLP-1) and glucose-dependent insulinotropic polypeptide (GIP) improve markers of cognitive function in obesity-diabetes, however, both are rapidly degraded to their major metabolites, GLP-1(9-36)amide and GIP(3-42), respectively. Therefore, the present study investigated effects of GLP-1(9-36)amide and GIP(3-42) on locomotor activity, cognitive function and hippocampal synaptic plasticity in mice with diet-induced obesity and insulin resistance. High-fat fed Swiss TO mice treated with GLP-1(9-36)amide, GIP(3-42) or exendin(9-39)amide (twice-daily for 60 days) did not exhibit any changes in bodyweight, non-fasting plasma glucose and plasma insulin concentrations or glucose tolerance compared with high-fat saline controls. Similarly, locomotor and feeding activity, O(2) consumption, CO(2) production, respiratory exchange ratio and energy expenditure were not altered by chronic treatment with incretin metabolites. Administration of the truncated metabolites did not alter general behavior in an open field test or learning and memory ability as recorded during an object recognition test. High-fat mice exhibited a significant impairment in hippocampal long-term potentiation (LTP) which was not affected by treatment with incretin metabolites. These data indicate that incretin metabolites do not influence locomotor activity, cognitive function and hippocampal synaptic plasticity when administered at pharmacological doses to mice fed a high-fat diet. Topics: Animals; Behavior, Animal; Cognition; Diet, High-Fat; Feeding Behavior; Gastric Inhibitory Polypeptide; Glucagon-Like Peptide 1; Hippocampus; Incretins; Long-Term Potentiation; Male; Mice; Motor Activity; Neuronal Plasticity; Obesity; Oxygen Consumption; Peptide Fragments; Peptides; Synapses | 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 |
Long-term high animal protein diet reduces body weight gain and insulin secretion in diet-induced obese rats.
The effects of a high protein diet on insulin secretion and glucose metabolism have been quite controversial. The aim of this study was to evaluate the effects of long-term isocaloric high animal protein intake on insulin secretion in diet-induced obese rats.. After the experimental period (24 weeks), the high-fat diet-induced obese rats that were fed isocaloric high-protein diets (HP) had lower body weight gain (P < 0.01) and lower visceral fat (P < 0.05) than normal protein (NP) rats. Fasting plasma glucagon-like peptide-1 (GLP-1) was also reduced significantly (P < 0.05), as well as serum insulin levels at 5 min and 10 min by intravenous insulin releasing test. In addition, insulin mRNA and pancreatic duodenal homeodomain-1 (PDX-1), GLP-1 protein expression were both markedly lower in HP rats (P < 0.05), while PDX-1 mRNA in HP rats had no difference from NP rats.. These results suggest that long-term isocaloric high animal protein intake reduces the acute insulin response in obese rats and the decrease of insulin is associated with both reduced weight gain and inhibition of PDX-1 expression. GLP-1 might be a negative feedback for the balance of energy metabolism secondary to changes of body weight and visceral fat. Topics: Animals; Diet, High-Fat; Dietary Proteins; Energy Metabolism; Glucagon-Like Peptide 1; Homeodomain Proteins; Insulin; Insulin Secretion; Intra-Abdominal Fat; Male; Obesity; Rats; Rats, Wistar; RNA, Messenger; Time Factors; Trans-Activators; Weight Gain | 2012 |
Butyrate and propionate protect against diet-induced obesity and regulate gut hormones via free fatty acid receptor 3-independent mechanisms.
Short-chain fatty acids (SCFAs), primarily acetate, propionate, and butyrate, are metabolites formed by gut microbiota from complex dietary carbohydrates. Butyrate and acetate were reported to protect against diet-induced obesity without causing hypophagia, while propionate was shown to reduce food intake. However, the underlying mechanisms for these effects are unclear. It was suggested that SCFAs may regulate gut hormones via their endogenous receptors Free fatty acid receptors 2 (FFAR2) and 3 (FFAR3), but direct evidence is lacking. We examined the effects of SCFA administration in mice, and show that butyrate, propionate, and acetate all protected against diet-induced obesity and insulin resistance. Butyrate and propionate, but not acetate, induce gut hormones and reduce food intake. As FFAR3 is the common receptor activated by butyrate and propionate, we examined these effects in FFAR3-deficient mice. The effects of butyrate and propionate on body weight and food intake are independent of FFAR3. In addition, FFAR3 plays a minor role in butyrate stimulation of Glucagon-like peptide-1, and is not required for butyrate- and propionate-dependent induction of Glucose-dependent insulinotropic peptide. Finally, FFAR3-deficient mice show normal body weight and glucose homeostasis. Stimulation of gut hormones and food intake inhibition by butyrate and propionate may represent a novel mechanism by which gut microbiota regulates host metabolism. These effects are largely intact in FFAR3-deficient mice, indicating additional mediators are required for these beneficial effects. Topics: Animals; Body Weight; Butyrates; Diet; Fatty Acids, Nonesterified; Gastric Inhibitory Polypeptide; Gastrointestinal Hormones; Glucagon-Like Peptide 1; Homeostasis; Insulin Resistance; Male; Mice; Mice, Inbred C57BL; Mice, Knockout; Obesity; Propionates; Receptors, G-Protein-Coupled | 2012 |
Basal glucagonlike peptide 1 levels and metabolic syndrome in obese patients.
Glucagonlike peptide 1 (GLP-1) is the most potent stimulator of glucose-induced insulin secretion. The purpose of the present study was to investigate the relationships of basal circulating GLP-1 and metabolic syndrome in obese patients without cardiovascular disease.. A sample of 202 obese patients was enrolled. Dietary intake, weight, bioimpedance, blood pressure, fasting glucose, insulin, C-reactive protein, total cholesterol, low-density lipoprotein cholesterol, high-density lipoprotein cholesterol, blood triglycerides, and GLP-1 levels were measured in all patients. To estimate the prevalence of metabolic syndrome, the definitions of the Adult Treatment Panel III was considered.. Patients were divided at the median of GLP-1 value (8.02 ng/dL): group 1 (n = 101) and group 2 (n = 101). Metabolic syndrome (MS) prevalence was higher in patients with the lowest median group of GLP-1 (52.5% vs 38.6%; P < 0.05). Correlation analysis showed a significant correlation among serum GLP-1 levels and the independent variables; waist-to-hip ratio (r = -0.15; P < 0.05), glucose (r = -0.15; P < 0.05), total cholesterol (r = -0.22; P < 0.05), and low-density lipoprotein cholesterol (r = -0.27; P < 0.05). In the logistic analysis with MS presence/absence as an independent variable, only weight and GLP-1 levels remained in the model. Weight shows an odds ratio of 1.10 (95% confidence interval, 1.06-1.13) by each increase of 1 kg of weight, and GLP-1 levels shows an odds ratio of 0.89 (95% confidence interval, 0.80-0.99) by each increase of 1 ng/dL of GLP-1 levels.. Obese patients with MS had lower mean GLP-1 levels than those without MS. Glucagonlike peptide 1 levels remained as a preventive factor to develop MS. Topics: Anthropometry; Diet; Female; Glucagon-Like Peptide 1; Humans; Male; Metabolic Syndrome; Middle Aged; Obesity | 2012 |
Shedding pounds after going under the knife: guts over glory-why diets fail.
Losing weight can pose a challenge, but how to avoid putting those pounds back on can be a real struggle. A major health problem for obese people is that diseases linked to obesity, such as type 2 diabetes and cardiovascular disease, put their lives at risk, even in young individuals. Although bariatric surgery-a surgical method to reduce or modify the gastrointestinal tract-was originally envisioned for the most severe cases of obesity, evidence suggests that the benefit of this procedure may not be limited to the staggering weight loss it causes. Endogenous factors released from the gut, and modified after surgery, may explain why bariatric surgery can be beneficial for obesity-related diseases and why operated individuals successfully maintain the weight loss. In 'Bedside to Bench,' Rachel Larder and Stephen O'Rahilly peruse a human study with dieters who regained weight despite a successful diet. Appetite-regulating hormones in the gut may be responsible for this relapse in the long term. In 'Bench to Bedside,' Keval Chandarana and Rachel Batterham examine how two different methods of bariatric surgery highlight the relevance of gut-derived hormones not only in inducing sustained weight loss but also in improving glucose homeostasis. These insights may open new avenues to bypass the surgery and obtain the same results with targeted drugs. Topics: Bariatric Surgery; Cholecystokinin; Glucagon-Like Peptide 1; Glucose; Humans; Obesity; Peptide YY; Weight Loss | 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 |
Estradiol increases body weight loss and gut-peptide satiation after Roux-en-Y gastric bypass in ovariectomized rats.
Despite the fact that ∼85% of bariatric operations are performed in women, the effects of the reproductive axis function on outcome of bariatric surgery remain to be determined. Here we developed the first published model of Roux-en-Y gastric bypass (RYGB) in female rats. We show in ovariectomized rats receiving estradiol or control treatment that (1) RYGB-induced body weight loss and (2) the satiating efficacy of endogenous glucagon-like peptide-1 and cholecystokinin satiation were significantly increased in estradiol-treated rats. These data are relevant to the care of obese women, in particular perimenopausal women, undergoing bariatric surgery. Topics: Animals; Biomarkers; Cholecystokinin; Estradiol; Estrogens; Feeding Behavior; Female; Gastric Bypass; Glucagon-Like Peptide 1; Menopause; Models, Animal; Obesity; Ovariectomy; Rats; Satiation; Treatment Outcome; Weight Loss | 2012 |
TGR5 potentiates GLP-1 secretion in response to anionic exchange resins.
Anionic exchange resins are bona fide cholesterol-lowering agents with glycemia lowering actions in diabetic patients. Potentiation of intestinal GLP-1 secretion has been proposed to contribute to the glycemia lowering effect of these non-systemic drugs. Here, we show that resin exposure enhances GLP-1 secretion and improves glycemic control in diet-induced animal models of "diabesity", effects which are critically dependent on TGR5, a G protein-coupled receptor that is activated by bile acids. We identified the colon as a major source of GLP-1 secretion after resin treatment. Furthermore, we demonstrate that the boost in GLP-1 release by resins is due to both enhanced TGR5-dependent production of the precursor transcript of GLP-1 as well as to the local enrichment of TGR5 agonists in the colon. Thus, TGR5 represents an essential component in the pathway mediating the enhanced GLP-1 release in response to anionic exchange resins. Topics: Animals; Anion Exchange Resins; Bile Acids and Salts; Blood Glucose; CHO Cells; Cholic Acids; Colon; Cricetinae; Cricetulus; Diet, High-Fat; Enteroendocrine Cells; Glucagon-Like Peptide 1; Insulin; Insulin Resistance; Male; Mice; Mice, Knockout; Obesity; Proglucagon; Receptors, G-Protein-Coupled; Reverse Transcriptase Polymerase Chain Reaction | 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 |
Glucagon-like peptide-1 inhibits adipose tissue macrophage infiltration and inflammation in an obese mouse model of diabetes.
Obesity and insulin resistance are associated with low-grade chronic inflammation. Glucagon-like peptide-1 (GLP-1) is known to reduce insulin resistance. We investigated whether GLP-1 has anti-inflammatory effects on adipose tissue, including adipocytes and adipose tissue macrophages (ATM).. We administered a recombinant adenovirus (rAd) producing GLP-1 (rAd-GLP-1) to an ob/ob mouse model of diabetes. We examined insulin sensitivity, body fat mass, the infiltration of ATM and metabolic profiles. We analysed the mRNA expression of inflammatory cytokines, lipogenic genes, and M1 and M2 macrophage-specific genes in adipose tissue by real-time quantitative PCR. We also examined the activation of nuclear factor κB (NF-κB), extracellular signal-regulated kinase 1/2 and Jun N-terminal kinase (JNK) in vivo and in vitro.. Fat mass, adipocyte size and mRNA expression of lipogenic genes were significantly reduced in adipose tissue of rAd-GLP-1-treated ob/ob mice. Macrophage populations (F4/80(+) and F4/80(+)CD11b(+)CD11c(+) cells), as well as the expression and production of IL-6, TNF-α and monocyte chemoattractant protein-1, were significantly reduced in adipose tissue of rAd-GLP-1-treated ob/ob mice. Expression of M1-specific mRNAs was significantly reduced, but that of M2-specific mRNAs was unchanged in rAd-GLP-1-treated ob/ob mice. NF-κB and JNK activation was significantly reduced in adipose tissue of rAd-GLP-1-treated ob/ob mice. Lipopolysaccharide-induced inflammation was reduced by the GLP-1 receptor agonist, exendin-4, in 3T3-L1 adipocytes and ATM.. We suggest that GLP-1 reduces macrophage infiltration and directly inhibits inflammatory pathways in adipocytes and ATM, possibly contributing to the improvement of insulin sensitivity. Topics: Adipose Tissue; Animals; Anti-Inflammatory Agents; Body Fat Distribution; Gene Expression Regulation; Glucagon-Like Peptide 1; Glucagon-Like Peptide-1 Receptor; Inflammation; Insulin Resistance; Macrophages; Mice; Mice, Obese; NF-kappa B; Obesity; Real-Time Polymerase Chain Reaction; Receptors, Glucagon | 2012 |
Implications of gastrointestinal hormones in the pathogenesis of obesity in prepubertal children.
There is a worsening high prevalence of global obesity. Special attention has been paid to the gut-endocrine system, represented by the regulators of appetite. In particular, it has been suggested that ghrelin ("hunger" peptide), and obestatin and glucagon-like peptide-1 (GLP-1) ("satiety" peptides) could play important roles in the pathogenesis of obesity.. The aims of this study were to compare fasting plasma ghrelin, obestatin, and GLP-1 levels between obese and nonobese prepubertal children, and to assess their relations with fatness indexes and insulin resistance (IR).. Fifty-two prepubertal obese children and 22 controls were enrolled. Fasting levels of gastrointestinal hormones (ghrelin, obestatin, and GLP-1), glucose, and insulin were evaluated. IR was assessed using the homeostasis model assessment of IR (HOMA-IR) index. Analysis was performed by Mann-Whitney U-test, Kruskal-Wallis test, and Spearman's correlation.. Obese prepubertal children and normal-weight controls had similar age distribution. Obese children were more insulin resistant when compared to controls (HOMA-IR: p < 0.01 ). GLP-1 levels were significantly lower in obese children than in controls (p < 0.01). Obestatin was significantly higher in obese than normal-weight children (p < 0.01), while ghrelin was not different. There was a negative correlation between GLP-1 and standard deviation score-body mass index (r = -0.36, p = 0.009) and between GLP-1 and waist circumference (r = -0.45, p = 0.001), while no association was observed with HOMA-IR.. GLP-1 levels have been shown to be correlated with adiposity indexes, but not with HOMA-IR, suggesting that this hormone could play an important role in the early development of obesity. Topics: Adiposity; Blood Glucose; Body Mass Index; Case-Control Studies; Child; Female; Gastrointestinal Hormones; Ghrelin; Glucagon-Like Peptide 1; Humans; Incretins; Insulin; Insulin Resistance; Leptin; Male; Obesity; Waist Circumference | 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 |
Glucagon-like peptide-1 agonist exendin-4 leads to reduction of weight and caloric intake in a rat model of hypothalamic obesity.
Hypothalamic obesity caused by damage of medial hypothalamic nuclei presents a therapeutic challenge. Glucagon-like peptide-1 agonist exenatide (synthetic version of exendin-4 (Ex4)), used for treatment of diabetes, causes weight loss via hindbrain signaling.. We tested Ex4 in an established rat model of medial hypothalamic lesions. Lesion and control animals were administered either daily intraperitoneal injections of 1 µg·kg(-1) Ex4 or saline for 9 days.. In our rat model, a significant difference in percent baseline food intake (lesion -20.8%, control -13.6%; p < 0.001) and percent change in body weight (lesion -4.9%/9 days, control -3.2%/9 days; p < 0.05) was observed during Ex4 treatment compared with saline.. Ex4 resulted in reduction of food intake and body weight. Follow-up studies are required to further elucidate its effects on energy homeostasis and to establish Ex4 as a potential drug for treatment of hypothalamic obesity. Topics: Animals; Body Weight; Disease Models, Animal; Down-Regulation; Drug Evaluation, Preclinical; Energy Intake; Exenatide; Glucagon-Like Peptide 1; Hypoglycemic Agents; Hypothalamic Diseases; Male; Obesity; Peptides; Rats; Rats, Sprague-Dawley; Venoms; Weight Loss | 2012 |
Treatment with glucagon-like Peptide-1 agonist exendin-4 in a patient with hypothalamic obesity secondary to intracranial tumor.
Patients with hypothalamic tumors frequently experience severe obesity, and its treatment with diet, exercise, and/or pharmacologic treatment has had limited effect. Glucagon-like peptide-1 agonist exenatide (exendin-4), used for treatment of type 2 diabetes, causes persistent weight loss via signaling in the brainstem.. We report the case of a 17-year-old patient with obesity resulting from a hypothalamic germ cell tumor. He was treated by chemoradiotherapy and exenatide at a dose of 5 µg subcutaneously twice daily.. Exenatide resulted in a 29-kg weight loss (BMI reduction from 37.1 to 29.1) after 2.5 years of treatment; significant weight gain occurred shortly after exenatide was discontinued.. Exenatide resulted in considerable reduction of body weight in a patient with severe hypothalamic obesity. This novel observation requires follow-up clinical studies for establishing the effects of exenatide in patients with disrupted hypothalamic energy regulatory pathways. Topics: Adolescent; Brain Neoplasms; Exenatide; Glucagon-Like Peptide 1; Humans; Hypoglycemic Agents; Hypothalamic Neoplasms; Male; Neoplasms, Germ Cell and Embryonal; Obesity; Peptides; Venoms | 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 |
Glucagon-like peptide-1 analogs against antipsychotic-induced weight gain: potential physiological benefits.
Antipsychotic-induced weight gain constitutes a major unresolved clinical problem which may ultimately be associated with reducing life expectancy by 25 years. Overweight is associated with brain deterioration, cognitive decline and poor quality of life, factors which are already compromised in normal weight patients with schizophrenia.Here we outline the current strategies against antipsychotic-induced weight gain, and we describe peripheral and cerebral effects of the gut hormone glucagon-like peptide-1 (GLP-1). Moreover, we account for similarities in brain changes between schizophrenia and overweight patients.. Current interventions against antipsychotic-induced weight gain do not facilitate a substantial and lasting weight loss. GLP-1 analogs used in the treatment of type 2 diabetes are associated with significant and sustained weight loss in overweight patients. Potential effects of treating schizophrenia patients with antipsychotic-induced weight gain with GLP-1 analogs are discussed.. We propose that adjunctive treatment with GLP-1 analogs may constitute a new avenue to treat and prevent metabolic and cerebral deficiencies in schizophrenia patients with antipsychotic-induced weight gain. Clinical research to support this idea is highly warranted. Topics: Antipsychotic Agents; Glucagon-Like Peptide 1; Humans; Obesity; Schizophrenia; Weight Gain | 2012 |
My brain made me do it, and my gut didn't help.
Decisions about what, when and how much to eat are made by the brain, though these choices can be strongly influenced by the hedonic and rewarding properties of sweet or fatty foods. The rumbling before and the fullness after eating tells us that the gut also has an important role in the initiation and termination of feeding. Gut-derived peptides continually convey homeostatic information to the brain to guide feeding. These circulating signals can also modify the pleasure and reward associated with food. Topics: Animals; Bariatric Surgery; Brain; Eating; Feeding Behavior; Glucagon-Like Peptide 1; Homeostasis; Humans; Molecular Targeted Therapy; Obesity; Peptide Fragments; Peptide YY; Reward | 2012 |
Lipid-mediated release of GLP-1 by mouse taste buds from circumvallate papillae: putative involvement of GPR120 and impact on taste sensitivity.
Glucagon-like peptide-1 (GLP-1) signaling modulates sweet-taste sensitivity in the mouse. Because circumvallate papillae (CVPs) express both GLP-1 and its receptor, a local regulation has been suggested. However, whether dietary lipids are involved in this regulation, as shown in the gut, is unknown. By using a combination of biochemical, immunohistochemical, and behavioral approaches, the present data i) confirm the role of GLP-1 signaling in the attraction for sucrose, ii) demonstrate that minute quantities of long-chain FAs (LCFAs) reinforce the attraction for sucrose in a GLP-1 receptor-dependent manner, iii) suggest an involvement of the LCFA receptor GPR120 expressed in taste buds in this system, and iv) support the existence of a regulation by GLP-1 of the lipid sensing mediated by lingual CD36. Therefore, oro-sensory detection of LCFAs may affect sweet and fatty taste responsiveness by controlling the secretion of lingual GLP-1. This regulatory loop, probably triggered by the LCFA-GPR120 interaction, might contribute to the high palatability of foods rich both in fat and sugar. Topics: Animals; Blotting, Western; CD36 Antigens; Cell Line, Tumor; Glucagon-Like Peptide 1; Glucagon-Like Peptide-1 Receptor; Humans; Immunohistochemistry; Mice; Mice, Inbred C57BL; Obesity; Real-Time Polymerase Chain Reaction; Receptors, G-Protein-Coupled; Receptors, Glucagon; Taste Buds | 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 |
Regular consumption of pulses for 8 weeks reduces metabolic syndrome risk factors in overweight and obese adults.
Pulses are low in energy density, supporting their inclusion in the diet for the management of risk factors of the metabolic syndrome (MetSyn). The aim of the present study was to describe the effects of frequent consumption (five cups/week over 8 weeks) of pulses (yellow peas, chickpeas, navy beans and lentils), compared with counselling to reduce energy intake by 2093 kJ/d (500 kcal/d), on risk factors of the MetSyn in two groups (nineteen and twenty-one subjects, respectively) of overweight or obese (mean BMI 32·8 kg/m2) adults. Body weight, waist circumference, blood pressure, fasting blood parameters and 24 h food intakes were measured at weeks 1, 4 and 8. Blood glucose, insulin, C-peptide, glucagon-like peptide-1 (GLP-1) and ghrelin were measured after a 75 g oral glucose load at weeks 1 and 8. At week 8, both groups reported reductions in energy intake, waist circumference, systolic blood pressure, glycosylated Hb (HbA1c) and glucose AUC and homeostasis model of insulin resistance (HOMA-IR) following the glucose load (P < 0·05). However, HDL, fasting C-peptide and insulin AUC responses were dependent on diet (P < 0·05). HDL and C-peptide increased by 4·5 and 12·3 %, respectively, in the pulse group, but decreased by 0·8 and 7·6 %, respectively, in the energy-restricted group. Insulin AUC decreased in both females and males on the energy-restricted diet by 24·2 and 4·8 %, respectively, but on the pulse diet it decreased by 13·9 % in females and increased by 27·3 % in males (P < 0·05). In conclusion, frequent consumption of pulses in an ad libitum diet reduced risk factors of the MetSyn and these effects were equivalent, and in some instances stronger, than counselling for dietary energy reduction. Topics: Adult; Blood Glucose; C-Peptide; Caloric Restriction; Counseling; Diet; Fabaceae; Female; Glucagon-Like Peptide 1; Humans; Insulin; Male; Metabolic Syndrome; Middle Aged; Obesity; Overweight; Risk Factors; Seeds; Waist Circumference | 2012 |
The role of the gut hormone GLP-1 in the metabolic improvements caused by ileal transposition.
Bariatric surgery alters the gastrointestinal hormonal milieu leading to improved glucose homeostasis, though the mechanism leading to these changes is poorly understood. Ileal transposition (IT) is a procedure that is neither restrictive nor malabsorptive but nevertheless produces profound improvements in glucose regulation. Ileal transposition involves a short segment of distal ileum being transposed to the proximal jejunum in an isoperistaltic direction, thereby avoiding any gastric resection or intestinal bypass.. Diet-induced obese rats underwent either ileal transposition (IT) or Sham procedures. The Sham operated rats were pair-fed to the IT surgical group to control for the effects of reduced food intake. Body composition data were recorded at specific time points, and glucose tolerance tests were performed at 5 and 6 wk, both in the presence and absence of Exendin 9-39, a known glucose-like peptide 1 (GLP-1) receptor antagonist. A subset of naïve rats were also maintained for comparison.. IT and Sham operated rats had no differences in food intake and body weight, however, IT rats had a significant decrease in their body fat composition (P < 0.05). No difference existed in glucose tolerance when exposed to an intraperitoneal glucose load, however, IT rats showed markedly improved glucose tolerance when submitted to an oral glucose tolerance test (P < 0.001). Blocking GLP-1 receptors reversed these important improvements in rats with IT surgery.. The present work recapitulates what is seen in rodents and humans that IT improves glucose tolerance and body composition. The present data provide compelling evidence that these improvements are a product of increased GLP-1 secretion that results from placing the key GLP-1 secreting cells closer to chyme coming from the stomach. Such data support the notion that rather than restriction or malabsorption, the underling molecular mechanisms that mediate the potent improvements produced by bariatric procedures involve increased activation of GLP-1 signaling. Topics: Animals; Bariatric Surgery; Body Composition; Body Weight; Eating; Glucagon-Like Peptide 1; Glucose; Glucose Intolerance; Glucose Tolerance Test; Homeostasis; Ileum; Jejunum; Male; Obesity; Random Allocation; Rats; Rats, Long-Evans; Signal Transduction | 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 |
MicroRNAs contribute to compensatory β cell expansion during pregnancy and obesity.
Pregnancy and obesity are frequently associated with diminished insulin sensitivity, which is normally compensated for by an expansion of the functional β cell mass that prevents chronic hyperglycemia and development of diabetes mellitus. The molecular basis underlying compensatory β cell mass expansion is largely unknown. We found in rodents that β cell mass expansion during pregnancy and obesity is associated with changes in the expression of several islet microRNAs, including miR-338-3p. In isolated pancreatic islets, we recapitulated the decreased miR-338-3p level observed in gestation and obesity by activating the G protein-coupled estrogen receptor GPR30 and the glucagon-like peptide 1 (GLP1) receptor. Blockade of miR-338-3p in β cells using specific anti-miR molecules mimicked gene expression changes occurring during β cell mass expansion and resulted in increased proliferation and improved survival both in vitro and in vivo. These findings point to a major role for miR-338-3p in compensatory β cell mass expansion occurring under different insulin resistance states. Topics: Adaptation, Physiological; Animals; Cells, Cultured; Cytokines; Estradiol; Estrogen Antagonists; Female; Fulvestrant; Gene Expression Regulation; Glucagon-Like Peptide 1; Glucagon-Like Peptide-1 Receptor; Insulin Resistance; Islets of Langerhans; Male; Mice; Mice, Mutant Strains; MicroRNAs; Obesity; Organ Size; Postpartum Period; Pregnancy; Rats; Rats, Wistar; Receptors, G-Protein-Coupled; Receptors, Glucagon; Signal Transduction | 2012 |
A major lineage of enteroendocrine cells coexpress CCK, secretin, GIP, GLP-1, PYY, and neurotensin but not somatostatin.
Enteroendocrine cells such as duodenal cholecystokinin (CCK cells) are generally thought to be confined to certain segments of the gastrointestinal (GI) tract and to store and release peptides derived from only a single peptide precursor. In the current study, however, transgenic mice expressing enhanced green fluorescent protein (eGFP) under the control of the CCK promoter demonstrated a distribution pattern of CCK-eGFP positive cells that extended throughout the intestine. Quantitative PCR and liquid chromatography-mass spectrometry proteomic analyses of isolated, FACS-purified CCK-eGFP-positive cells demonstrated expression of not only CCK but also glucagon-like peptide 1 (GLP-1), gastric inhibitory peptide (GIP), peptide YY (PYY), neurotensin, and secretin, but not somatostatin. Immunohistochemistry confirmed this expression pattern. The broad coexpression phenomenon was observed both in crypts and villi as demonstrated by immunohistochemistry and FACS analysis of separated cell populations. Single-cell quantitative PCR indicated that approximately half of the duodenal CCK-eGFP cells express one peptide precursor in addition to CCK, whereas an additional smaller fraction expresses two peptide precursors in addition to CCK. The coexpression pattern was further confirmed through a cell ablation study based on expression of the human diphtheria toxin receptor under the control of the proglucagon promoter, in which activation of the receptor resulted in a marked reduction not only in GLP-1 cells, but also PYY, neurotensin, GIP, CCK, and secretin cells, whereas somatostatin cells were spared. Key elements of the coexpression pattern were confirmed by immunohistochemical double staining in human small intestine. It is concluded that a lineage of mature enteroendocrine cells have the ability to coexpress members of a group of functionally related peptides: CCK, secretin, GIP, GLP-1, PYY, and neurotensin, suggesting a potential therapeutic target for the treatment and prevention of diabetes and obesity. Topics: Animals; Cell Lineage; Cell Separation; Cholecystokinin; Diabetes Mellitus; Enteroendocrine Cells; Flow Cytometry; Gastric Inhibitory Polypeptide; Gene Expression Regulation; Ghrelin; Glucagon-Like Peptide 1; Green Fluorescent Proteins; Humans; Immunohistochemistry; Intestinal Mucosa; Mice; Mice, Transgenic; Neurotensin; Obesity; Peptide YY; Promoter Regions, Genetic | 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 |
GLP-1 secretion by microglial cells and decreased CNS expression in obesity.
Type 2 diabetes (T2D) is a strong risk factor for developing neurodegenerative pathologies. T2D patients have a deficiency in the intestinal incretin hormone GLP-1, which has been shown to exert neuroprotective and anti-inflammatory properties in the brain.. Here we investigate potential sources of GLP-1 in the CNS and the effect of diabetic conditions on the proglucagon mRNA expression in the CNS. The obese mouse model ob/ob, characterized by its high levels of free fatty acids, and the microglia cell line BV-2 were used as models. mRNA expression and protein secretion were analyzed by qPCR, immunofluorescence and ELISA.. We show evidence for microglia as a central source of GLP-1 secretion. Furthermore, we observed that expression and secretion are stimulated by cAMP and dependent on microglial activation state. We also show that insulin-resistant conditions reduce the central mRNA expression of proglucagon.. The findings that microglial mRNA expression of proglucagon and GLP-1 protein expression are affected by high levels of free fatty acids and that both mRNA expression levels of proglucagon and secretion levels of GLP-1 are affected by inflammatory stimuli could be of pathogenic importance for the premature neurodegeneration and cognitive decline commonly seen in T2D patients, and they may also be harnessed to advantage in therapeutic efforts to prevent or treat such disorders. Topics: Animals; Arginase; CD11b Antigen; Cell Line, Transformed; Central Nervous System; Chitinases; Cyclic AMP; Disease Models, Animal; Gene Expression Regulation; Glucagon-Like Peptide 1; Insulin Resistance; Male; Mice; Mice, Inbred C57BL; Mice, Obese; Microglia; Obesity; Palmitates; Plant Proteins; Polysaccharides; Proglucagon; RNA, Messenger; Statistics, Nonparametric; Transfection; Tumor Necrosis Factor-alpha | 2012 |
A novel human-based receptor antagonist of sustained action reveals body weight control by endogenous GLP-1.
Ex-4 (9-39)a is a well characterized GLP-1 receptor antagonist that suffers from two notable limitations, its nonhuman amino acid sequence and its relatively short in vivo duration of action. Comparable N-terminal shortening of human GLP-1 lessens agonism but does not provide a high potency antagonist. Through a series of GLP-1/Ex-4 hybrid peptides, the minimal structural changes required to generate a pure GLP-1-based antagonist were identified as Glu16, Val19, and Arg20, yielding an antagonist of approximately 3-fold greater in vitro potency compared with Ex-4 (9-39)a. The structural basis of antagonism appears to result from stabilization of the α helix combined with enhanced electrostatic and hydrophobic interactions with the extracellular domain of the receptor. Site-specific acylation of the human-based antagonist yielded a peptide of increased potency as a GLP-1 receptor antagonist and 10-fold greater selectivity relative to the GIP receptor. The acylated antagonist demonstrated sufficient duration of action to maintain inhibitory activity when administered as a daily subcutaneous injection. The sustained pharmacokinetics and enhanced human sequence combine to form an antagonist optimized for clinical study. Daily administration of this antagonist by subcutaneous injection to diet-induced obese mice for 1 week caused a significant increase in food intake, body weight, and glucose intolerance, demonstrating endogenous GLP-1 as a relevant hormone in mammalian energy balance in the obese state. Topics: Acylation; Amino Acid Sequence; Animals; Binding Sites; Body Weight; Dietary Fats; Eating; Energy Metabolism; Glucagon-Like Peptide 1; Humans; Mice; Mice, Obese; Molecular Sequence Data; Obesity; Peptides; Receptors, Glucagon | 2011 |
Pre-treatment with a DPP-4 inhibitor is infarct sparing in hearts from obese, pre-diabetic rats.
Cardiovascular risk is closely associated with insulin resistance and type 2 diabetes. Therapy based on the actions of GLP-1 is currently seen as a novel approach to treat this disease. The aims of this study was therefore to use an animal model to determine whether (i) pre-treatment of obese, insulin resistant but pre-diabetic rats with a DPP4 inhibitor, PFK275-055, could protect the heart from ischaemia/reperfusion injury and (ii) the possible mechanisms involved in such protection. Obese, pre-diabetic rats (DIO) were treated for 4 weeks with 10 mg/kg/day of the DPP4 inhibitor PFK275-055. Ex vivo perfusion was used to subject hearts to ischaemia/reperfusion to determine infarct size, functional recovery and post-ischaemic activation of proteins associated with cardiac protection. Adult ventricular cardiomyocytes were isolated to determine insulin sensitivity. Other assessments included body weight, intra-peritoneal fat weight, insulin and GLP-1 levels as well as histological evaluation of the pancreata. Results showed that DIO animals had higher body mass and intra-peritoneal fat mass than chow-fed animals. They presented with elevated plasma insulin levels and lower GLP-1 levels. Treatment with the DPP4 inhibitor resulted in smaller infarct size development in hearts from DIO rats after ischaemia/reperfusion accompanied by activation of cardioprotective kinases. GLP-1 levels were elevated and plasma insulin levels lower after treatment. In addition, the beta-cell to alpha-cell ratio of the pancreas was improved. We conclude that treatment with PFK275-055 for 4 weeks protected the heart against ischaemia/reperfusion injury, elevated GLP-1 levels and improved metabolic control in obese, pre-diabetic rats. Topics: Animals; Blood Glucose; Body Weight; Cardiotonic Agents; Dipeptidyl-Peptidase IV Inhibitors; Glucagon; Glucagon-Like Peptide 1; Insulin; Insulin Resistance; Male; Myocardial Reperfusion Injury; Myocytes, Cardiac; Obesity; Pancreas; Phosphotransferases; Prediabetic State; Rats; Rats, Wistar | 2011 |
Loss of intestinal GATA4 prevents diet-induced obesity and promotes insulin sensitivity in mice.
Transcriptional regulation of small intestinal gene expression controls plasma total cholesterol (TC) and triglyceride (TG) levels, which are major determinants of metabolic diseases. GATA4, a zinc finger domain transcription factor, is critical for jejunal identity, and intestinal GATA4 deficiency leads to a jejunoileal transition. Although intestinal GATA4 ablation is known to misregulate jejunal gene expression, its pathophysiological impact on various components of metabolic syndrome remains unknown. Here, we used intestine-specific GATA4 knockout (GATA4iKO) mice to dissect the contribution of GATA4 on obesity development. We challenged adult GATA4iKO mice and control littermates with a Western-type diet (WTD) for 20 wk. Our findings show that WTD-fed GATA4iKO mice are resistant to diet-induced obesity. Accordingly, plasma TG and TC levels are markedly decreased. Intestinal lipid absorption in GATA4iKO mice was strongly reduced, whereas luminal lipolysis was unaffected. GATA4iKO mice displayed a greater glucagon-like peptide-1 (GLP-1) release on normal chow and even after long-term challenge with WTD remained glucose sensitive. In summary, our findings show that the absence of intestinal GATA4 has a beneficial effect on decreasing intestinal lipid absorption causing resistance to hyperlipidemia and obesity. In addition, we show that increased GLP-1 release in GATA4iKO mice decreases the risk for development of insulin resistance. Topics: Adipose Tissue; Animals; Diet; Dietary Fats; Enzyme-Linked Immunosorbent Assay; Feces; Gastric Emptying; GATA4 Transcription Factor; Glucagon-Like Peptide 1; Glucose Tolerance Test; Hyperlipidemias; Insulin Resistance; Intestinal Absorption; Intestinal Mucosa; Lipolysis; Magnetic Resonance Imaging; Mice; Mice, Knockout; Obesity; Reverse Transcriptase Polymerase Chain Reaction; RNA; Tissue Distribution | 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 |
Eating rate during a fixed-portion meal does not affect postprandial appetite and gut peptides or energy intake during a subsequent meal.
Eating rate has recently been shown to influence energy intake and appetite during an ad libitum meal, and alter postprandial secretion of glucagon-like peptide-1 (GLP-1) and peptide-YY (PYY) following a fixed-portion meal. Whether these effects influence satiety, as measured by energy intake at the subsequent meal, is unclear. We manipulated eating rate during a fixed-portion meal in order to examine how eating behavior and associated periprandial and postprandial responses of putative endocrine mediators of appetite would affect energy intake at the following meal in fifteen non-obese (BMI<25 kg/m²) and ten obese (BMI ≥ 30 kg/m²) healthy adult men and women. In random order, each participant consumed a standardized, fixed-portion meal in 7 (FM), 14 (MM) or 28 (SM) minutes. Fullness, measured by the Satiety Labeled Intensity Magnitude (SLIM) scale, serum insulin, glucose, leptin, pancreatic polypeptide (PP), PYY, GLP-1, neuropeptide-Y, and plasma cholecystokinin (CCK) were measured for 3h following the fixed-portion meal. Ad libitum energy intake at the next meal was then measured. Eating slowly delayed time to peak fullness (P ≤ 0.05), but did not alter peak fullness. Peak PP concentrations were attenuated during FM compared to MM and SM (P ≤ 0.05) and were reached earlier during MM compared to SM (P ≤ 0.05). A meal-by-time interaction (P ≤ 0.05), but no differences in AUC, peak, or time to peak were observed for CCK. No additional between meal differences in AUC, peak or time to peak for any endocrine mediator of appetite was observed. Ad libitum energy intake was not different between trials. In conclusion, the rate at which a fixed-portion meal is consumed does not appear to alter satiety despite a small effect on PP and CCK responses. Topics: Adolescent; Adult; Appetite; Blood Glucose; Cholecystokinin; Eating; Energy Intake; Feeding Behavior; Female; Glucagon-Like Peptide 1; Humans; Insulin; Leptin; Male; Middle Aged; Neuropeptide Y; Obesity; Pancreatic Polypeptide; Peptide YY; Postprandial Period; Satiation; Time Factors | 2011 |
JTT-130, a novel intestine-specific inhibitor of microsomal triglyceride transfer protein, suppresses high fat diet-induced obesity and glucose intolerance in Sprague-Dawley rats.
Microsomal triglyceride transfer protein (MTP) takes part in the mobilization and secretion of triglyceride-rich lipoproteins from enterocytes and hepatocytes. We investigated the effects of JTT-130, a novel intestine-specific MTP inhibitor, on high fat diet-induced obesity and glucose intolerance.. Male Sprague-Dawley rats were fed a 3.1% fat diet or a 35% fat diet with or without JTT-130 as a food admixture (0.029%). Food intake, body weight, abdominal fat, hepatic triglyceride, faecal free fatty acids and plasma levels of glucagon-like peptide-1 (GLP-1) and peptide YY (PYY) were assessed. Plasma levels of glucose and insulin were measured during intraperitoneal glucose tolerance tests. In addition, indirect calorimetry was performed on rats fed with a 35% fat diet.. JTT-130 treatment decreased body weights, abdominal fat and hepatic triglyceride with suppression of food intake and elevation of faecal free fatty acids and plasma GLP-1 and PYY levels in rats fed with the 35% fat diet, whereas no significant effects on these parameters except for increased faecal free fatty acids were observed in rats fed with the 3.1% fat diet. JTT-130 treatment decreased plasma levels of glucose and insulin during intraperitoneal glucose tolerance tests on rats fed with the 35% fat diet, but not on rats fed with the 3.1% fat diet. JTT-130-treated rats showed increased O(2) consumption and CO(2) production on a 35% fat diet.. JTT-130 suppresses high fat diet-induced obesity and glucose intolerance with suppression of food intake and fat absorption and could be useful for prevention and treatment of obesity and obesity-related insulin resistance. Topics: Animals; Benzamides; Biomarkers; Blood Glucose; Carrier Proteins; Diet, High-Fat; Dietary Fats; Eating; Fatty Acids; Feces; Glucagon-Like Peptide 1; Glucose Intolerance; Glucose Tolerance Test; Hypoglycemic Agents; Insulin; Insulin Resistance; Liver; Male; Malonates; Obesity; Peptide YY; Rats; Rats, Sprague-Dawley; Triglycerides | 2011 |
Diet and gastrointestinal bypass-induced weight loss: the roles of ghrelin and peptide YY.
Bariatric surgery causes durable weight loss. Gut hormones are implicated in obesity pathogenesis, dietary failure, and mediating gastrointestinal bypass (GIBP) surgery weight loss. In mice, we determined the effects of diet-induced obesity (DIO), subsequent dieting, and GIBP surgery on ghrelin, peptide YY (PYY), and glucagon-like peptide-1 (GLP-1). To evaluate PYY's role in mediating weight loss post-GIBP, we undertook GIBP surgery in PyyKO mice.. Male C57BL/6 mice randomized to a high-fat diet or control diet were killed at 4-week intervals. DIO mice underwent switch to ad libitum low-fat diet (DIO-switch) or caloric restriction (CR) for 4 weeks before being killed. PyyKO mice and their DIO wild-type (WT) littermates underwent GIBP or sham surgery and were culled 10 days postoperatively. Fasting acyl-ghrelin, total PYY, active GLP-1 concentrations, stomach ghrelin expression, and colonic Pyy and glucagon expression were determined. Fasting and postprandial PYY and GLP-1 concentrations were assessed 30 days postsurgery in GIBP and sham pair-fed (sham.PF) groups.. DIO progressively reduced circulating fasting acyl-ghrelin, PYY, and GLP-1 levels. CR and DIO-switch caused weight loss but failed to restore circulating PYY to weight-appropriate levels. After GIBP, WT mice lost weight and exhibited increased circulating fasting PYY and colonic Pyy and glucagon expression. In contrast, the acute effects of GIBP on body weight were lost in PyyKO mice. Fasting PYY and postprandial PYY and GLP-1 levels were increased in GIBP mice compared with sham.PF mice.. PYY plays a key role in mediating the early weight loss observed post-GIBP, whereas relative PYY deficiency during dieting may compromise weight-loss attempts. Topics: Analysis of Variance; Animals; Colon; Diet, Fat-Restricted; Diet, Reducing; Enzyme-Linked Immunosorbent Assay; Gastric Bypass; Gastric Mucosa; Ghrelin; Glucagon; Glucagon-Like Peptide 1; Leptin; Male; Mice; Obesity; Peptide YY; Radioimmunoassay; Random Allocation; Reverse Transcriptase Polymerase Chain Reaction; Weight Loss | 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 |
Upregulation of alpha cell glucagon-like peptide 1 (GLP-1) in Psammomys obesus--an adaptive response to hyperglycaemia?
The hormone glucagon-like peptide 1 (GLP-1) is released in response to a meal from the intestinal L-cells, where it is processed from proglucagon by the proconvertase (PC)1/3. In contrast, in the adult islets proglucagon is processed to glucagon by the PC2 enzyme. The aim of the study was to evaluate if, during the development of diabetes, alpha cells produce GLP-1 that, in turn, might trigger beta cell growth.. Beta cell mass, GLP-1 and insulin levels were measured in the gerbil Psammomys obesus (P. obesus), a rodent model of nutritionally induced diabetes. Furthermore, the presence of biologically active forms of GLP-1 and PC1/3 in alpha cells was demonstrated by immunofluorescence, and the release of GLP-1 from isolated P. obesus, mouse and human islets was investigated.. During the development of diabetes in P. obesus, a significant increase in GLP-1 was detected in the portal vein (9.8 ± 1.5 vs 4.3 ± 0.7 pmol/l, p < 0.05), and in pancreas extracts (11.4 ± 2.2 vs 5.1 ± 1.3 pmol/g tissue, p < 0.05). Freshly isolated islets from hyperglycaemic animals released more GLP-1 following 24 h culture than islets from control animals (28.2 ± 4.4 pmol/l vs 5.8 ± 2.4, p < 0.01). GLP-1 release was increased from healthy P. obesus islets following culture in high glucose for 6 days (91 ± 9.1 pmol/l vs 28.8 ± 6.6, p < 0.01). High levels of GLP-1 were also found to be released from human islets. PC1/3 colocalised weakly with alpha cells.. GLP-1 release from alpha cells is upregulated in P. obesus during the development of diabetes. A similar response is seen in islets exposed to high glucose, which supports the hypothesis that GLP-1 released from alpha cells promotes an increase in beta cell mass and function during metabolic challenge such as diabetes. Topics: Adaptation, Physiological; Adult; Animals; Cell Proliferation; Cells, Cultured; Diabetes Mellitus; Diet; Disease Models, Animal; Dose-Response Relationship, Drug; Female; Gerbillinae; Glucagon-Like Peptide 1; Glucagon-Secreting Cells; Glucose; Humans; Hyperglycemia; Insulin; Insulin-Secreting Cells; Islets of Langerhans; Male; Mice; Middle Aged; Obesity; Up-Regulation | 2011 |
Hyperphagia and increased fat accumulation in two models of chronic CNS glucagon-like peptide-1 loss of function.
Central administration of glucagon-like peptide-1 (GLP-1) causes a dose-dependent reduction in food intake, but the role of endogenous CNS GLP-1 in the regulation of energy balance remains unclear. Here, we tested the hypothesis that CNS GLP-1 activity is required for normal energy balance by using two independent methods to achieve chronic CNS GLP-1 loss of function in rats. Specifically, lentiviral-mediated expression of RNA interference was used to knock down nucleus of the solitary tract (NTS) preproglucagon (PPG), and chronic intracerebroventricular (ICV) infusion of the GLP-1 receptor (GLP-1r) antagonist exendin (9-39) (Ex9) was used to block CNS GLP-1r. NTS PPG knockdown caused hyperphagia and exacerbated high-fat diet (HFD)-induced fat accumulation and glucose intolerance. Moreover, in control virus-treated rats fed the HFD, NTS PPG expression levels correlated positively with fat mass. Chronic ICV Ex9 also caused hyperphagia; however, increased fat accumulation and glucose intolerance occurred regardless of diet. Collectively, these data provide the strongest evidence to date that CNS GLP-1 plays a physiologic role in the long-term regulation of energy balance. Moreover, they suggest that this role is distinct from that of circulating GLP-1 as a short-term satiation signal. Therefore, it may be possible to tailor GLP-1-based therapies for the prevention and/or treatment of obesity. Topics: Adiposity; Analysis of Variance; Animals; Dietary Fats; Energy Metabolism; Feeding Behavior; Fluorescent Antibody Technique; Glucagon-Like Peptide 1; Glucose Intolerance; Hyperphagia; In Situ Hybridization; Injections, Intraventricular; Islets of Langerhans; Male; Motor Activity; Obesity; Peptide Fragments; Proglucagon; Rats; Rats, Long-Evans; Reverse Transcriptase Polymerase Chain Reaction; RNA Interference; RNA, Messenger; Tissue Culture Techniques | 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 |
Hyperinsulinemic hypoglycemia after Roux-en-Y gastric bypass: unraveling the role of gut hormonal and pancreatic endocrine dysfunction.
Profound hypoglycemia occurs rarely as a late complication after Roux-en-Y gastric bypass (RYGB). We investigated the role of glucagon-like-peptide-1 (GLP-1) in four subjects who developed recurrent neuro-glycopenia 2 to 3 y after RYGB.. A standardized test meal (STM) was administered to all four subjects. A 2 h hyperglycemic clamp with GLP-1 infusion during the second hour was performed in one subject, before, during a 4 wk trial of octreotide (Oc), and after 85% distal pancreatectomy. After cessation of both glucose and GLP-1 infusion at the end of the 2 h clamp, blood glucose levels were monitored for 30 min. Responses were compared with a control group (five subjects 12 mo status post-RYGB without hypoglycemic symptoms).. During STM, both GLP-1 and insulin levels were elevated 3- to 4-fold in all subjects, and plasma glucose-dependent insulinotropic peptide (GIP) levels were elevated 2-fold. Insulin responses to hyperglycemia ± GLP-1 infusion in one subject were comparable to controls, but after cessation of glucose infusion, glucose levels fell to 40 mg/dL. During Oc, the GLP-1 and insulin responses to STM were reduced (>50%). During the clamp, insulin response to hyperglycemia alone was reduced, but remained unchanged during GLP-1. Glucagon levels during hyperglycemia alone were suppressed and further suppressed after the addition of GLP-1. With the substantial drop in glucose during the 30 min follow-up, glucagon levels failed to rise. Due to persistent symptoms, one subject underwent 85% distal pancreatectomy; postoperatively, the subject remained asymptomatic (blood glucose: 119-220 mg/dL), but a repeat STM showed persistence of elevated levels of GLP-1. Histologically enlarged islets, and β-cell clusters scattered throughout the acinar parenchyma were seen, as well as β-cells present within pancreatic duct epithelium. An increase in pancreatic and duodenal homeobox-1 protein (PDX-1) expression was observed in the subject compared with control pancreatic tissue.. A persistent exaggerated hypersecretion of GLP-1, which has been shown to be insulinotropic, insulinomimetic, and glucagonostatic, is the likely cause of post-RYGB hypoglycemia. The hypertrophy and ectopic location of β-cells is likely due to overexpression of the islet cell transcription factor, PDX-1, caused by prolonged hypersecretion of GLP-1. Topics: Blood Glucose; Endocrine System; Female; Gastric Bypass; Gastric Inhibitory Polypeptide; Gastrointestinal Tract; Glucagon-Like Peptide 1; Glycogen; Homeodomain Proteins; Humans; Hyperinsulinism; Hypoglycemia; Insulin; Middle Aged; Obesity; Pancreas; Trans-Activators | 2011 |
Comparative effects of the long-acting GLP-1 receptor ligands, liraglutide and exendin-4, on food intake and body weight suppression in rats.
The glucagon-like-peptide-1 receptor (GLP-1R) agonists, liraglutide (Victoza) and the synthetic product of exendin-4 (Byetta), are approved for type II diabetes mellitus (T2DM) treatment and may be efficacious in obesity treatment as well, in part, due to the drugs' resistance to enzymatic degradation and prolonged half-life relative to endogenous GLP-1. To address the need to directly compare the food intake- and body weight-suppressive effects of these two GLP-1R ligands, acute and chronic dosing experiments were performed. Once-daily (q.d.) exendin-4 (0, 0.33, 1.5, and 3.0 µg/kg) and liraglutide (0, 50, 100, and 300 µg/kg, q.d.) both reduced the chow intake in nonobese rats in a dose-dependent fashion following either intraperitoneal (IP) or subcutaneous (SC) administration, whereas only liraglutide reduced 24 and 48 h body weight in nonobese, chow-maintained rats. Chow intake and body weight suppression by liraglutide were of greater magnitude and shorter latency following IP compared to SC delivery, whereas for exendin-4, the magnitude of intake-suppression was similar for IP and SC administration. The effects of chronic delivery (7 consecutive days; IP) of liraglutide (25 and 50 µg/kg; q.d.) and exendin-4 (3 µg/kg; q.d. and twice-daily (b.i.d.)) on food intake and body weight were also examined in diet-induced obese (DIO) rats. Liraglutide (50 µg/kg q.d.) and exendin-4 (3 µg/kg b.i.d.) were comparable in suppressing overall high fat/sucrose diet (HFS; 60% kcal from fat) intake. Both drugs regimens yielded marked weight loss over the 7-day period. The weight loss effect of liraglutide was achieved in the first 2 days and remained stable for the duration of the experiment; weight loss with exendin-4 appeared more linear over the 7-day period. In conclusion, administration of the GLP-1R ligands, exendin-4 (b.i.d.) and liraglutide (q.d.), lead to comparable and pronounced suppression of food intake and body weight in DIO rats, suggesting a potential role for these drugs as a clinical tool for obesity treatment. Topics: Animals; Anti-Obesity Agents; Appetite Regulation; Dietary Fats; Dietary Sucrose; Dose-Response Relationship, Drug; Exenatide; Glucagon-Like Peptide 1; Glucagon-Like Peptide-1 Receptor; Hypoglycemic Agents; Injections, Intraperitoneal; Injections, Subcutaneous; Ligands; Liraglutide; Male; Obesity; Peptides; Rats; Rats, Sprague-Dawley; Receptors, Glucagon; Time Factors; Venoms; Weight Loss | 2011 |
[The effects of high-protein, low-carbohydrate diet on body weight and the expression of gastrointestinal hormones in diet-induced obesity rat].
To investigate the effects of long-term high-protein, low-carbohydrate diet on body weight and the expression of gastrointestinal hormones in diet-induced obesity rats.. Twenty-four diet-induced obesity rat models were established by feeding fat-enriched diet, then were randomly divided into two groups by stratified sampling method by weight: the high-protein diet group (HP, 36.7% of energy from protein), and the normal chow group (NC, 22.4% of energy from protein), 12 rats in each group. The total calorie intake of each rat per day was similar and was maintained for 24 weeks, then body weight, visceral fat mass, fasting plasma ghrelin and glucagon-like peptide-1 (GLP-1) were determined, as well as protein expression of ghrelin in stomach, GLP-1 in ileum were detected by immunohistochemistry.. After 24 weeks, body weight of HP, NC groups were (490.92 ± 39.47) g and (545.55 ± 31.08) g, respectively (t = -3.664, P < 0.01); visceral fat mass were (22.42 ± 7.04) g and (32.33 ± 9.27) g, respectively (t = -2.503, P < 0.05); plasma ghrelin level were (2.36 ± 0.82) and (1.95 ± 0.64) ng/ml, respectively (t = 1.337, P > 0.05), and plasma ghrelin level was negatively correlated to body weight (r = -0.370, t = -1.899, P < 0.05), visceral fat mass (r = -0.454, t = -2.52, P < 0.01); plasma GLP-1 concentration were (0.52 ± 0.13) and (0.71 ± 0.19) ng/ml, respectively(t = -2.758, P < 0.05); ghrelin protein expression in stomach were 25 473 ± 8701 and 10 526 ± 6194, respectively (t = 2.501, P < 0.05); GLP-1 protein expression in ileum were 27 431 ± 5813 and 36 601 ± 5083, respectively (t = -1.833, P = 0.081).. Long-term isocaloric high-protein, low-carbohydrate diet can reduce body weight and visceral fat, increase the expression of ghrelin, and decline GLP-1 expression in diet-induced obesity rats. Topics: Animals; Body Weight; Diet, Carbohydrate-Restricted; Dietary Proteins; Gastrointestinal Hormones; Ghrelin; Glucagon-Like Peptide 1; Intra-Abdominal Fat; Male; Obesity; Rats; Rats, Wistar | 2011 |
Pharmacological targeting of glucagon and glucagon-like peptide 1 receptors has different effects on energy state and glucose homeostasis in diet-induced obese mice.
Pharmacologic contributions of directly agonizing glucagon-like peptide 1 (GLP-1) receptor or antagonizing glucagon receptor (GCGR) on energy state and glucose homeostasis were assessed in diet-induced obese (DIO) mice. Metabolic rate and respiratory quotient (RQ), hyperglycemic clamp, stable isotope-based dynamic metabolic profiling (SiDMAP) studies of (13)C-labeled glucose during glucose tolerance test (GTT) and gene expression were assessed in cohorts of DIO mice after a single administration of GLP-1 analog [GLP-1-(23)] or anti-GCGR antibody (Ab). GLP-1-(23) and GCGR Ab similarly improved GTT. GLP-1-(23) decreased food intake and body weight trended lower. GCGR Ab modestly decreased food intake without significant effect on body weight. GLP-1-(23) and GCGR Ab decreased RQ with GLP-1, causing a greater effect. In a hyperglycemic clamp, GLP-1-(23) reduced hepatic glucose production (HGP), increased glucose infusion rate (GIR), increased glucose uptake in brown adipose tissue, and increased whole-body glucose turnover, glycolysis, and rate of glycogen synthesis. GCGR Ab slightly decreased HGP, increased GIR, and increased glucose uptake in the heart. SiDMAP showed that GLP-1-(23) and GCGR Ab increased (13)C lactate labeling from glucose, indicating that liver, muscle, and other organs were involved in the rapid disposal of glucose from plasma. GCGR Ab and GLP-1-(23) caused different changes in mRNA expression levels of glucose- and lipid metabolism-associated genes. The effect of GLP-1-(23) on energy state and glucose homeostasis was greater than GCGR Ab. Although GCGR antagonism is associated with increased circulating levels of GLP-1, most GLP-1-(23)-associated pharmacologic effects are more pronounced than GCGR Ab. Topics: Animals; Antibodies, Monoclonal; Blood Glucose; Body Weight; Dietary Fats; Drug Delivery Systems; Energy Metabolism; Glucagon-Like Peptide 1; Glucagon-Like Peptide-1 Receptor; Homeostasis; Humans; Male; Mice; Mice, Inbred C57BL; Obesity; Receptors, Glucagon | 2011 |
Compensation for obesity-induced insulin resistance in dogs: assessment of the effects of leptin, adiponectin, and glucagon-like peptide-1 using path analysis.
The hormonal mediators of obesity-induced insulin resistance and compensatory hyperinsulinemia in dogs have not been identified. Plasma samples were obtained after a 24-h fast from 104 client-owned lean, overweight, and obese dogs. Plasma glucose and insulin concentrations were used to calculate insulin sensitivity and β-cell function with the use of the homeostasis model assessment (HOMA(insulin sensitivity) and HOMA(β-cell function), respectively). Path analysis with multivariable linear regression was used to identify whether fasting plasma leptin, adiponectin, or glucagon-like peptide-1 concentrations were associated with adiposity, insulin sensitivity, and basal insulin secretion. None of the dogs were hyperglycemic. In the final path model, adiposity was positively associated with leptin (P < 0.01) and glucagon-like peptide-1 (P = 0.04) concentrations. No significant total effect of adiposity on adiponectin in dogs (P = 0.24) was observed. If there is a direct effect of leptin on adiponectin, then our results indicate that this is a positive relationship, which at least partly counters a negative direct relationship between adiposity and adiponectin. Fasting plasma leptin concentration was directly negatively associated with fasting insulin sensitivity (P = 0.01) and positively associated with β-cell function (P < 0.01), but no direct association was observed between adiponectin concentration and either insulin sensitivity or β-cell function (P = 0.42 and 0.11, respectively). We conclude that dogs compensate effectively for obesity-induced insulin resistance. Fasting plasma leptin concentrations appear to be associated with obesity-associated changes in insulin sensitivity and compensatory hyperinsulinemia in naturally occurring obese dogs. Adiponectin does not appear to be involved in the pathophysiology of obesity-associated changes in insulin sensitivity. Topics: Adiponectin; Adiposity; Animals; Blood Glucose; Dog Diseases; Dogs; Fasting; Glucagon-Like Peptide 1; Insulin; Insulin Resistance; Insulin-Secreting Cells; Leptin; Obesity | 2011 |
Changes in glucose homeostasis after Roux-en-Y gastric bypass surgery for obesity at day three, two months, and one year after surgery: role of gut peptides.
Endocrine effects of gastric bypass (GBP) surgery for obesity on glucose homeostasis are not fully understood.. The main objective of the study was to assess the changes in plasma glucose, insulin, glucagon-like peptide-1 (GLP-1), leptin, somatostatin, glucose-dependent insulinotropic peptide, enteroglucagon, and glucagon early after GBP.. Twelve obese subjects (body mass index 45.3 ± 1.9 kg/m(2)) were subjected to a liquid meal without lipids before and 3 d, 2 months, and 1 yr after GBP. Plasma concentrations of glucose, insulin, leptin, and gut peptide hormones were assessed before and for 180 min after the meal. Satiety was measured with visual analog scales. The absorption rate of acetaminophen added to the liquid meal was measured. Insulin resistance was measured by the homeostasis model assessment of insulin resistance.. All subjects lost weight (body mass index 30.3 ± 1.8 kg/m(2) at 1 yr). Fasting glucose was significantly lower on d 3 (P < 0.05). There was a progressive decrease in the homeostasis model assessment of insulin resistance after 2 months postoperatively. Postprandially, there was a progressive rise of GLP-1 and enteroglucagon and a transient increase in pancreatic glucagon release over the study period. There was a leftward shift of the time course of plasma glucose and insulin. Somatostatin release was lower on d 3 (P < 0.05) but then unchanged. The absorption rate of acetaminophen was twice as fast after GBP compared with before surgery and did not change over time. Satiety scores increased markedly postoperatively.. Both enhanced insulin sensitivity and incretin hormones, such as GLP-1, contribute to the early control of glucose homeostasis. Progressively increasing postprandial levels of enteroglucagon (oxyntomodulin) and GLP-1 facilitate weight loss and enhance insulin effectiveness. Topics: Adult; Blood Glucose; Female; Follow-Up Studies; Gastric Bypass; Glucagon-Like Peptide 1; Homeostasis; Humans; Insulin; Leptin; Male; Obesity; Somatostatin; Treatment Outcome | 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 |
Dissociated incretin hormone response to protein versus fat ingestion in obese subjects.
Protein elicits a stronger early (30 min) glucose-dependent insulinotropic polypeptide (GIP) response than fat ingestion in lean individuals, with no difference in glucagon-like peptide-1 (GLP-1). We assessed the incretin hormone response to protein versus fat ingestion in obesity. Equicaloric (8 kcal/kg) fat (olive oil) or protein (whey protein) was ingested by non-diabetic obese male volunteers [body mass index (BMI) >30 kg/m(2) ; n = 12] and plasma GIP and GLP-1 were determined. We found no difference in the early GIP or GLP-1 responses to fat versus protein. However, the total 300-min GIP response was greater after fat than after protein ingestion (20.3 ± 3.9 vs. 10.0 ± 2.8 nmol/l × min; p = 0.026), whereas the 300-min GLP-1 responses were the same. Thus, in obesity, protein and fat ingestion elicit similar early (30 min) incretin hormone responses, whereas 300-min GIP secretion is more pronounced after fat than protein ingestion. Topics: Adult; Dietary Fats; Dietary Proteins; Gastric Inhibitory Polypeptide; Glucagon-Like Peptide 1; Humans; Incretins; Male; Obesity | 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 |
The incretin effect and secretion in obese and lean women with polycystic ovary syndrome: a pilot study.
Insulin resistance is considered to play an important role in the pathogenesis of polycystic ovary syndrome (PCOS) and in the progression to type 2 diabetes. Recent reports concentrate on a possible relationship between incretin secretion and beta-cell function in PCOS. The aim of the present study is to investigate the incretin effect in obese and lean women with PCOS.. Twenty women with PCOS and ten age-matched healthy women were recruited in the study. The oral glucose tolerance test (OGTT) and isoglycemic test were carried out on each participant after an overnight fast at 2-weeks interval. Plasma levels of insulin, glucose, C-peptide, glucose-dependent insulinotropic peptide (GIP) and glucagon-like peptide-1 (GLP-1) were assayed.. Obese women with PCOS demonstrated lower GIP concentrations (area under the curve [AUC]) in response to OGTT compared to the control group. The incretin effect was found significantly augmented in the obese women with PCOS compared to controls. This finding remained robust in the subgroup analysis including only body mass index (BMI)-matched healthy women.. Increased insulinotropic effect could counteract the blunted GIP response to OGTT in obese women with PCOS. It is suggested that the pathology of PCOS may also include impaired activity of the enteroinsular axis. Topics: Adult; Analysis of Variance; Area Under Curve; Body Mass Index; Case-Control Studies; Female; Gastric Inhibitory Polypeptide; Glucagon-Like Peptide 1; Glucose Tolerance Test; Greece; Humans; Incretins; Insulin; Obesity; Pilot Projects; Polycystic Ovary Syndrome; Thinness; Young Adult | 2011 |
Olanzapine effects on body composition, food preference, glucose metabolism and insulin sensitivity in the rat.
The atypical antipsychotic drug olanzapine induces weight gain and defects in glucose metabolism in patients. Using a rat model we investigated the effects of acute and long term olanzapine treatment on weight gain, food preference and glucose metabolism. Olanzapine treated rats fed a chow diet grew more slowly than vehicle controls but olanzapine treated animals fed a high fat/sugar diet grew faster than control animals on the same diet. These changes in weight were paralleled by changes in fat mass. Olanzapine also induced a strong preference for a high fat/high sugar diet. Acute exposure to olanzapine rapidly induced severe impairments of glucose tolerance and increased insulin secretion but did not impair insulin tolerance. These results indicate the defect in glucose metabolism induced by acute olanzapine treatment was most likely due to increased hepatic glucose output associated with a reduction in active GLP-1 levels and correspondingly high glucagon levels. Topics: Animals; Antipsychotic Agents; Benzodiazepines; Body Composition; Body Weight; Diet, High-Fat; Food Preferences; Glucagon; Glucagon-Like Peptide 1; Glucose; Glucose Tolerance Test; Humans; Insulin; Insulin Resistance; Liver; Male; Obesity; Olanzapine; Rats; Schizophrenia; Weight Gain | 2011 |
Chronic treatment with a glucagon receptor antagonist lowers glucose and moderately raises circulating glucagon and glucagon-like peptide 1 without severe alpha cell hypertrophy in diet-induced obese mice.
Antagonism of the glucagon receptor (GCGR) represents a potential approach for treating diabetes. Cpd-A, a potent and selective GCGR antagonist (GRA) was studied in preclinical models to assess its effects on alpha cells.. Studies were conducted with Cpd-A to examine the effects on glucose-lowering efficacy, its effects in combination with a dipeptidyl peptidase-4 (DPP-4) inhibitor, and the extent and reversibility of alpha cell hypertrophy associated with GCGR antagonism in mouse models.. Chronic treatment with Cpd-A resulted in effective and sustained glucose lowering in mouse models in which endogenous murine Gcgr was replaced with human GCGR (hGCGR). Treatment with Cpd-A also led to stable, moderate elevations in both glucagon and glucagon-like peptide 1 (GLP-1) levels, which were completely reversible and not associated with a hyperglycaemic overshoot following termination of treatment. When combined with a DPP-4 inhibitor, Cpd-A led to additional improvement of glycaemic control correlated with elevated active GLP-1 levels after glucose challenge. In contrast to Gcgr-knockout mice in which alpha cell hypertrophy was detected, chronic treatment with Cpd-A in obese hGCGR mice did not result in gross morphological changes in pancreatic tissue.. A GRA lowered glucose effectively in diabetic models without significant alpha cell hypertrophy during or following chronic treatment. Treatment with a GRA may represent an effective approach for glycaemic control in patients with type 2 diabetes, which could be further enhanced when combined with DPP-4 inhibitors. Topics: Animals; Blood Glucose; Diabetes Mellitus, Experimental; Dietary Fats; Dipeptidyl-Peptidase IV Inhibitors; Disease Models, Animal; Dose-Response Relationship, Drug; Glucagon; Glucagon-Like Peptide 1; Glucagon-Secreting Cells; Hypertrophy; In Vitro Techniques; Male; Mice; Mice, Knockout; Obesity; Receptors, Glucagon; Streptozocin | 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 |
Weight-independent changes in blood glucose homeostasis after gastric bypass or vertical sleeve gastrectomy in rats.
Roux-en-Y gastric bypass (RYGB) and vertical sleeve gastrectomy (VSG) reduce weight and improve glucose metabolism in obese patients, although it is not clear if metabolic changes are independent of weight loss. We investigated alterations in glucose metabolism in rats following RYGB or VSG.. Rats underwent RYGB or VSG and were compared to sham-operated rats fed ad lib or pair-fed to animals that received RYGB. Intraperitoneal glucose tolerance and insulin sensitivity tests were performed to assess glycemic function independent of incretin response. A hyperinsulinemic euglycemic clamp was used to compare tissue-specific changes in insulin sensitivity following each procedure. A mixed-meal tolerance test was used to assess the effect of each surgery on postprandial release of glucagon-like peptide 1 (GLP-1)(7-36) and glucose tolerance, and was also performed in rats given GLP-1 receptor antagonist exendin(9-39).. Following RYGB or VSG, glucose tolerance and insulin sensitivity improved in proportion to weight loss. Hepatic insulin sensitivity was significantly better in rats that received RYGB or VSG compared with rats fed ad lib or pair-fed, whereas glucose clearance was similar in all groups. During the mixed-meal tolerance test, plasma levels of GLP-1(7-36) and insulin were greatly and comparably increased in rats that received RYGB and VSG compared with those that were pair-fed or fed ad lib. Administration of a GLP-1 receptor antagonist prevented improvements in glucose and insulin responses after a meal among rats that received RYGB or VSG.. In obese rats, VSG is as effective as RYGB for increasing secretion of GLP-1 and insulin and improving hepatic sensitivity to insulin; these effects are independent of weight loss. Topics: Animals; Blood Glucose; Body Weight; Dietary Fats; Disease Models, Animal; Eating; Gastrectomy; Gastric Bypass; Glucagon-Like Peptide 1; Homeostasis; Insulin; Insulin Resistance; Male; Obesity; Postprandial Period; Rats; Rats, Long-Evans; Stomach | 2011 |
Association of TCF7L2 allelic variations with gastric function, satiation, and GLP-1 levels.
Genetic variation in transcription factor 7-like 2 (TCF7L2), a regulator of proglucagon processing, is reproducibly associated with type 2 diabetes. GLP-1 alters gastric function and increases satiation.. Genetic variation in TCF7L2 is associated with satiation, gastric motor function, and GLP-1 concentrations.. In 62 adults, a single nucleotide polymorphism (SNP) of TCF7L2 (rs7903146) was genotyped and associations with gastric emptying (GE) of solids and liquids, gastric volume (GV), and satiation (maximum tolerated volume and symptoms after nutrient drink test) were explored using a dominant genetic model, with gender and BMI as covariates. In 50 of the participants, we also measured plasma GLP-1 during fasting and after ingestion of a nutrient drink.. Presence of the T allele compared to CC genotype in rs7903146 SNP of the TCF7L2 gene was associated with reduced fasting GV (246.3 ± 11.4 mL for CC group, compared to 215.7 ± 11.4 mL for CT/TT group, p= 0.05) and accelerated GE t(1/2) of liquids (26.3 ± 2.0 minutes for CC compared to 17.7 ± 1.4 for CT/TT, p < 0.005). There was no significant association of rs7903146 SNP with GE of solids, gastric accommodation, satiation, fasting, or postprandial GLP-1.. Our data suggest TCF7L2 is associated with altered gastric functions that may predispose to obesity. Topics: Adolescent; Adult; Aged; Alleles; Body Mass Index; Female; Gastric Mucosa; Genetic Predisposition to Disease; Genetic Variation; Genotype; Glucagon-Like Peptide 1; Humans; Male; Middle Aged; Obesity; Polymorphism, Single Nucleotide; Proglucagon; Radionuclide Imaging; Satiation; Stomach; Transcription Factor 7-Like 2 Protein | 2011 |
[Anti-obesity drugs: status quo and recent advances].
Obesity has become a major health problem worldwide. The prevalence and morbidity of obesity-related diseases including diabetes, hypertension, cerebro-cardiovascular diseases, and tumors also have remarkably increased. Treatment of obesity poses a challenge for clinicians. Anti-obesity treatment is helpful to improve and even reverse obesity-related complications. Diet control and physical exercises remain the predominant interventions for obese patients. Anti-obesity drugs can be considered in those who respond poorly to behavioral intervention or those who have developed obesity-related complications. The commonly used anti-obesity drugs include gastrointestinal lipase inhibitors and appetite suppressants. Glucagon-like peptide 1 has also been found to be effective in reducing body weight. Some more drugs are under development, which include selective 5-HT 2c agonist, β3 receptor agonist, and melanocortin receptor 4 agonist, may also be promising. Topics: Anti-Obesity Agents; Appetite Depressants; Glucagon-Like Peptide 1; Humans; Obesity | 2011 |
In adults with Prader-Willi syndrome, elevated ghrelin levels are more consistent with hyperphagia than high PYY and GLP-1 levels.
Prader-Willi syndrome (PWS) is a leading genetic cause of obesity, characterized by hyperphagia, endocrine and developmental disorders. It is suggested that the intense hyperphagia could stem, in part, from impaired gut hormone signaling. Previous studies produced conflicting results, being confounded by differences in body composition between PWS and control subjects.. Fasting and postprandial gut hormone responses were investigated in a cross-sectional cohort study including 10 adult PWS, 12 obese subjects matched for percentage body fat and central abdominal fat, and 10 healthy normal weight subjects.. PYY[total], PYY[3-36], GLP-1[active] and ghrelin[total] were measured by ELISA or radioimmunoassay. Body composition was assessed by dual energy X-ray absorptiometry. Visual analog scales were used to assess hunger and satiety.. In contrast to lean subjects (p<0.05), PWS and obese subjects were similarly insulin resistant and had similar insulin levels. Ghrelin[total] levels were significantly higher in PWS compared to obese subjects before and during the meal (p<0.05). PYY[3-36] meal responses were higher in PWS than in lean subjects (p=0.01), but not significantly different to obese (p=0.08), with an additional non-significant trend in PYY[total] levels. There were no significant differences in self-reported satiety between groups, however PWS subjects reported more hunger throughout (p=0.003), and exhibited a markedly reduced meal-induced suppression of hunger (p=0.01) compared to lean or obese subjects.. Compared to adiposity-matched control subjects, hyperphagia in PWS is not related to a lower postprandial GLP-1 or PYY response. Elevated ghrelin levels in PWS are consistent with increased hunger and are unrelated to insulin levels. Topics: Adult; Blood Glucose; Body Composition; Cohort Studies; Cross-Sectional Studies; Fasting; Female; Ghrelin; Glucagon-Like Peptide 1; Humans; Hunger; Hyperphagia; Insulin; Male; Obesity; Peptide YY; Postprandial Period; Prader-Willi Syndrome; Signal Transduction; Young Adult | 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 |
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 |
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 |
GLP-1 analogs reduce hepatocyte steatosis and improve survival by enhancing the unfolded protein response and promoting macroautophagy.
Nonalcoholic fatty liver disease (NAFLD) is a known outcome of hepatosteatosis. Free fatty acids (FFA) induce the unfolded protein response (UPR) or endoplasmic reticulum (ER) stress that may induce apoptosis. Recent data indicate ER stress to be a major player in the progression of fatty liver to more aggressive lesions. Autophagy on the other hand has been demonstrated to be protective against ER stress-induced cell death. We hypothesized that exendin-4 (GLP-1 analog) treatment of fat loaded hepatocytes can reduce steatosis by autophagy which leads to reduced ER stress-related hepatocyte apoptosis.. Primary human hepatocytes were loaded with saturated, cis- and trans-unsaturated fatty acids (palmitic, oleic and elaidic acid respectively). Steatosis, induced with all three fatty acids, was significantly resolved after exendin-4 treatment. Exendin-4 sustained levels of GRP78 expression in fat-loaded cells when compared to untreated fat-loaded cells alone. In contrast, CHOP (C/EBP homologous protein); the penultimate protein that leads to ER stress-related cell death was significantly decreased by exendin-4 in hepatocytes loaded with fatty acids. Finally, exendin-4 in fat loaded hepatocytes clearly promoted gene products associated with macroautophagy as measured by enhanced production of both Beclin-1 and LC3B-II, markers for autophagy; and visualized by transmission electron microscopy (TEM). Similar observations were made in mouse liver lysates after mice were fed with high fat high fructose diet and treated with a long acting GLP-1 receptor agonist, liraglutide.. GLP-1 proteins appear to protect hepatocytes from fatty acid-related death by prohibition of a dysfunctional ER stress response; and reduce fatty acid accumulation, by activation of both macro-and chaperone-mediated autophagy. These findings provide a novel role for GLP-1 proteins in halting the progression of more aggressive lesions from underlying steatosis in humans afflicted with NAFLD. Topics: Adipocytes; Animals; Apoptosis; Autophagy; Diet, High-Fat; Dietary Carbohydrates; Endoplasmic Reticulum Chaperone BiP; Endoplasmic Reticulum Stress; Exenatide; Fatty Liver; Fructose; Glucagon-Like Peptide 1; Hepatocytes; Humans; Life Style; Male; Mice; Mice, Inbred C57BL; Obesity; Peptides; Survival Analysis; Unfolded Protein Response; Venoms | 2011 |
Gastric bypass surgery: improving psoriasis through a GLP-1-dependent mechanism?
Psoriasis is a common inflammatory skin disease and obesity constitutes a risk factor for the disease. Obese patients with psoriasis are often more difficult to treat and are at increased risk for dyslipidemia, diabetes, hypertension and cardiovascular disease. Case reports suggest that gastric bypass surgery in patients with psoriasis may result in complete remission of the disease. A substantial weight loss is achieved in the months following surgery, which is likely to reduce psoriasis symptoms and risk of comorbidities. Interestingly, however, it has been described that improvement of psoriasis is initiated immediately following surgery before any weight loss could have happened. We hypothesize that the glucose-lowering gut incretin hormone glucagon-like peptide-1 (GLP-1) is responsible for this effect. The levels of GLP-1 have been shown to increase up to 20 times after gastric bypass surgery. This most likely contributes importantly to the acute remission of type 2 diabetes, which is often induced by gastric bypass operations. The hormone is not hypersecreted after the purely restrictive bariatric procedure gastric banding and no case reports exist on improvement in psoriasis following gastric banding. Intriguingly, recent studies describe that GLP-1 may convey anti-inflammatory effects in addition to its effects on glucose homeostasis. Also, GLP-1 reduces appetite and gastrointestinal motility including gastric emptying, which reduces food intake and leads to weight loss. Thus, both a direct anti-inflammatory effect of GLP-1 as well as an indirect effect through weight loss could contribute to improvement in psoriasis. A potential involvement of GLP-1 in the remission of psoriasis observed after bariatric surgery offers exciting possibilities for research and eventually perhaps new ways of anti-psoriatic treatment. Topics: Gastric Bypass; Glucagon-Like Peptide 1; Humans; Models, Biological; Obesity; Psoriasis; Remission Induction; Skin; Weight Loss | 2011 |
Adverse metabolic effects of a hypercaloric, high-fat diet in rodents precede observable changes in body weight.
Although a high-fat diet (HFD) is recognized as an important contributor to obesity, human research is limited by confounders such as income, whereas animal research has typically examined diet during specific developmental periods rather than throughout the lifespan. We hypothesized that the use of an HFD in short-term studies as has been commonly done in animals does not adequately reflect the lifelong dietary patterns seen frequently in humans with consequent metabolic disturbances. We examined the impact of HFD from weaning until 39 weeks (middle age) on the metabolism of male rats. At 7, 26, and 39 weeks, glucose tolerance tests were performed, a subset of animals was euthanized, and serum and tissues were collected. After 4 weeks, preceding increased body weight, HFD animals had increased intra-abdominal fat, triglycerides, and hyperglycemia. Hyperinsulinemia was insufficient to maintain normoglycemia, and beta cell mass and glucagon-like peptide 1 decreased over time in HFD and control animals. Despite lacking significant lipid abnormalities, nonalcoholic fatty liver disease was evident by 39 weeks. Our HFD model demonstrated that significant metabolic abnormalities may go undetected by current standard screening such as weighing and biochemistry. Topics: Adiposity; Animals; Blood Glucose; Body Weight; Diet, High-Fat; Dietary Fats; Disease Models, Animal; Fatty Liver; Glucagon-Like Peptide 1; Glucose Tolerance Test; Glycemic Index; Hyperglycemia; Hyperinsulinism; Insulin; Intra-Abdominal Fat; Male; Non-alcoholic Fatty Liver Disease; Obesity; Rats; Rats, Wistar; Triglycerides | 2011 |
Surgical treatments for obesity.
Bariatric surgery is currently the most effective and durable treatment option for extreme obesity. Restrictive procedures, such as AGB and SG, limit gastric capacity and, thus, food intake while leaving the gastrointestinal tract intact. Malabsorptive procedures, such as BPD, shorten the length of the intestine to decrease nutrient absorption. Combined procedures, such as RYGB, include restriction and gastrointestinal rearrangement. Procedures that bypass segments of the gut are associated with greater weight loss and greater improvements in comorbid conditions than is gastric banding. This may be due, in part, to the differential effects of gastrointestinal rearrangement on the secretion of orexigenic and anorexigenic gut peptides that regulate appetite, glucose homeostasis, and body weight. Bariatric surgery is generally associated with low rates of perioperative and postoperative morbidity and mortality, although rigorous comparative safety data are lacking. High-quality, long-term, randomized, controlled trials are needed to compare the efficacy, safety, and cost effectiveness of the various bariatric surgery procedures with each other, as well as with intensive nonsurgical weight loss interventions. Topics: Anastomosis, Roux-en-Y; Bariatric Surgery; Biliopancreatic Diversion; Endoscopy, Digestive System; Ghrelin; Glucagon-Like Peptide 1; Humans; Obesity; Peptide YY; Treatment Outcome; Weight Loss | 2011 |
Mate tea (Ilex paraguariensis) promotes satiety and body weight lowering in mice: involvement of glucagon-like peptide-1.
We previously investigated the effects of an aqueous extract of maté (mate) tea, made from the leaves of Ilex paraguariensis, on the diabesity and metabolic syndrome features in a mouse model. Mate induced significant decreases in body weight (BW), body mass index, and food intake (FI). In this study, to verify the mode of action of mate on FI and consequently on BW, we examined the anorexic effects of mate on the appetite and satiety markers glucagon-like peptide 1 (GLP-1) and leptin in high-fat diet-fed ddY mice. GLP-1 is a peptide signal generated by the gastrointestinal tract, which regulates appetite and influences BW, whereas leptin is an afferent signal from the periphery to the brain in a homeostatic feedback loop that regulates adipose tissue mass, thus leading to decreased appetite and FI and increased energy expenditure. Chronic administration of mate (50, 100 mg/kg) for 3 weeks significantly reduced FI, BW, and ameliorated blood fats, liver fats, and adipose tissue. Mate induced significant increases in GLP-1 levels and leptin levels compared with the control. Acute administration of major constituents of mate showed significant increases in GLP-1 levels by dicaffeoyl quinic acids and matesaponins, and significant induction of satiety by caffeoyl quinic acids and caffeine in ddY mice. These findings suggest that mate may induce anorexic effects by direct induction of satiety and by stimulation of GLP-1 secretion and modulation of serum leptin levels. Topics: Animals; Anti-Obesity Agents; Beverages; Diet, High-Fat; Dipeptidyl Peptidase 4; Disease Models, Animal; Eating; Fatty Acids; Glucagon-Like Peptide 1; Ilex paraguariensis; Leptin; Liver; Male; Mice; Obesity; Phytotherapy; Plant Extracts; Plant Leaves; Satiation; Triglycerides; Weight Gain | 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 |
Effects of sleeve gastrectomy surgery with modified jejunoileal bypass on body weight, food intake and metabolic hormone levels of rats.
This study examined the effects of a combined surgery of sleeve gastrectomy (SG) and modified jejunoileal bypass (JIB) on the body weight, food intake, and the plasma levels of active glucagon-like peptide-1 (GLP-1) and total ghrelin of rats. Rats were divided into 3 groups in terms of different surgical protocol: SG-JIB (n=12), SG (n=12), JIB (n=12) and sham surgery groups (n=10). In SG-JIB group, rats was subjected to sleeve gastrectomy and end to side anastomosis of part of the jejunum (25 cm from the ligament of Treitz) to the ileum 25 cm proximal to the cecum. The body weight and food intake were evaluated during 10 consecutive weeks postoperatively. The levels of active GLP-1 and total ghrelin in the plasma of the rats were measured by ELISA assay. The results showed that the SG-JIB treated rats relative to SG- or JIB-treated ones produced a sustained reduction in food intake and weight gain. The level of active GLP-1 was elevated and total ghrelin level decreased in SG-JIB-treated rats as compared with SG- or JIB-treated ones. It was concluded that SG-JIB could efficiently reduce the body weight and food intake, alter obesity-related hormone levels of the rats, indicating that SG-JIB may be potentially used for the treatment of obesity. Topics: Animals; Bariatric Surgery; Dietary Fats; Eating; Gastrectomy; Ghrelin; Glucagon-Like Peptide 1; Intestine, Small; Jejunoileal Bypass; Male; Obesity; Rats; Rats, Wistar; Weight Loss | 2011 |
The gut: key to treating obesity in adolescents?
Topics: Adolescent; Endoscopy; Energy Intake; Feeding Behavior; Gastrointestinal Tract; Glucagon-Like Peptide 1; Humans; Islet Amyloid Polypeptide; Lipase; Obesity; Prevalence; Serotonin Agents | 2011 |
Oral glucose leads to a differential response in glucose, insulin, and GLP-1 in lean versus obese cats.
The response to oral glucose was examined in 10 obese and 9 lean age-matched, neutered cats. In all cats, oral administration of 2g/kg glucose was followed by a prompt increase in glucose, insulin, and glucagon-like peptide (GLP)-1. There were significant differences between lean and obese cats in the areas under the curve for glucose, insulin, and GLP-1. However, the responses were variable, and a clear distinction between individual lean and obese cats was not possible. Therefore, this test cannot be recommended as a routine test to examine insulin resistance in individual cats as it is used in people. A further disadvantage for routine use is also the fact that this test requires gastric tubing for the correct administration of the glucose and associated tranquilization to minimize stress and that it was associated with development of diarrhea in 25% of the cats. GLP-1 concentrations were much lower in obese than lean cats. The low GLP-1 concentrations in obese cats might indicate a contribution of GLP-1 to the lower insulin sensitivity of obese cats, but this hypothesis needs to be further investigated. Topics: Animals; Blood Glucose; Cat Diseases; Cats; Female; Glucagon-Like Peptide 1; Glucose; Glucose Tolerance Test; Insulin; Kinetics; Male; Obesity; Species Specificity | 2010 |
Secretion and dipeptidyl peptidase-4-mediated metabolism of incretin hormones after a mixed meal or glucose ingestion in obese compared to lean, nondiabetic men.
Glucose-dependent insulinotropic polypeptide (GIP) and glucagon-like peptide-1 (GLP-1) are cleaved by dipeptidyl peptidase-4 (DPP-4); plasma activity of DPP-4 may be increased in obesity. The impact of this increase on incretin hormone secretion and metabolism is not known.. The aim of the study was to assess incretin hormone secretion and degradation in lean and obese nondiabetic subjects.. We studied the ingestion of a mixed meal (560 kcal) or oral glucose (2 g/kg) in healthy lean (n = 12; body mass index, 20-25 kg/m(2)) or obese (n = 13; body mass index, 30-35 kg/m(2)) males at a University Clinical Research Unit.. We measured the area under the curve of plasma intact (i) and total (t) GIP and GLP-1 after meal ingestion and oral glucose.. Plasma DPP-4 activity was higher in the obese subjects (38.5 +/- 3.0 vs. 26.7 +/- 1.6 mmol/min . microl; P = 0.002). Although GIP secretion (AUC(tGIP)) was not reduced in obese subjects after meal ingestion or oral glucose, AUC(iGIP) was lower in obese subjects (8.5 +/- 0.6 vs. 12.7 +/- 0.9 nmol/liter x 300 min; P < 0.001) after meal ingestion. GLP-1 secretion (AUC(tGLP-1)) was reduced in obese subjects after both meal ingestion (7.3 +/- 0.9 vs. 10.0 +/- 0.6 nmol/liter x 300 min; P = 0.022) and oral glucose (6.6 +/- 0.8 vs. 9.6 +/- 1.1 nmol/liter x 180 min; P = 0.035). iGLP-1 was reduced in parallel to tGLP-1.. 1) Release and degradation of the two incretin hormones show dissociated changes in obesity: GLP-1 but not GIP secretion is lower after meal ingestion and oral glucose, whereas GIP but not GLP-1 metabolism is increased after meal ingestion. 2) Increased plasma DPP-4 activity in obesity is not associated with a generalized augmented incretin hormone metabolism. Topics: Acetaminophen; Adult; Area Under Curve; Dipeptidyl Peptidase 4; Food; Gastric Inhibitory Polypeptide; Glucagon-Like Peptide 1; Glucose; Humans; Insulin Resistance; Male; Obesity; Thinness; Young Adult | 2010 |
Colesevelam improves insulin resistance in a diet-induced obesity (F-DIO) rat model by increasing the release of GLP-1.
Bile acid sequestrants have been shown to lower glucose levels in patients with type 2 diabetes. To investigate how colesevelam (CL) HCl improves hyperglycemia, studies were conducted in diet-induced obesity (F-DIO) rats, which develop insulin resistance when fed a high-energy (high fat/high sucrose) diet (HE). The rats were fed HE; HE + 2% CL; HE + 0.02% SC-435 (SC), an apical sodium-dependent bile acid transporter inhibitor; and regular chow (controls). After 4 wk of treatment, both in the HE group and the SC + HE group, plasma glucose and insulin levels remained elevated compared with baseline values throughout an oral glucose tolerance test (OGTT). In contrast, in the CL + HE group, plasma glucose levels returned to baseline by the end of the test, and insulin peaked in 15-30 min and then returned to baseline. CL induced release of glucagon-like peptide-1 (GLP-1) because the area under the curve of plasma total GLP-1 in the CL + HE group was significantly greater than in the HE group during the OGTT. Bile acid concentrations in the portal blood did not decrease in the HE group but declined significantly both in the CL + HE and SC + HE groups with reduced farnesoid X receptor activation compared with controls. We concluded that CL reduces plasma glucose levels by improving insulin resistance in this rat model. It is unlikely that the improvement is attributable to decreased bile acid flux to the liver but is likely secondary to induced GLP-1 secretion, which improves insulin release. Topics: Allylamine; Animals; Anticholesteremic Agents; Bile Acids and Salts; Blood Glucose; Body Weight; Carrier Proteins; Cholesterol; Cholesterol 7-alpha-Hydroxylase; Colesevelam Hydrochloride; Cyclic N-Oxides; Dietary Carbohydrates; Dietary Fats; Gene Expression; Glucagon-Like Peptide 1; Glucose Tolerance Test; Ileum; Insulin; Insulin Resistance; Liver; Male; Membrane Glycoproteins; Obesity; Organic Anion Transporters, Sodium-Dependent; Portal Vein; Rats; Rats, Inbred F344; Receptors, Cytoplasmic and Nuclear; Symporters; Triglycerides; Tropanes | 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 |
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 |
Liraglutide for weight loss in obese people.
Topics: Anti-Obesity Agents; Female; Glucagon-Like Peptide 1; Humans; Incretins; Liraglutide; Male; Nausea; Obesity; Treatment Outcome; Vomiting; Weight Loss | 2010 |
Liraglutide for weight loss in obese people.
Topics: Anti-Obesity Agents; Comorbidity; Female; Glucagon-Like Peptide 1; Humans; Incretins; Liraglutide; Male; Metabolic Syndrome; Obesity; Treatment Outcome; Weight Loss | 2010 |
Meal-induced hormone responses in a rat model of Roux-en-Y gastric bypass surgery.
Roux-en-Y gastric bypass (RYGB) surgery is the most effective treatment for morbid obesity and remission of associated type 2 diabetes, but the mechanisms involved are poorly understood. The aim of the present study was to develop and validate a rat model for RYGB surgery that allows repeated measurement of meal-induced changes in gut and pancreatic hormones via chronic venous catheters. Male Sprague Dawley rats made obese on a palatable high-fat diet were subjected to RYGB or sham surgery and compared with chow-fed, lean controls. Hormonal responses to a mixed-liquid test meal were examined by frequent blood sampling through chronically implanted jugular catheters in freely behaving rats, 3-4 months after surgery, when RYGB rats had significantly reduced body weight and fat mass compared with sham-operated rats. Hyperleptinemia, basal hyperinsulinemia, and hyperglycemia as well as postprandial glucose intolerance seen in sham-operated, obese rats were completely reversed by RYGB and no longer different from lean controls. Postprandial increases in glucagon-like peptide-1, peptide YY, and amylin as well as suppression of ghrelin levels were all significantly augmented in RYGB rats compared with both sham-operated obese and lean control rats. Thus, our rat model replicates most of the salient hormonal and glycemic changes reported in obese patients after RYGB, with the addition of amylin to the list of potential candidate hormones involved in hypophagia, weight loss, and remission of diabetes. The model will be useful for elucidating the specific peripheral and central mechanisms involved in the suppression of appetite, loss of body weight, and remission of type 2 diabetes. Topics: Amyloid; Analysis of Variance; Animals; Body Weight; Eating; Gastric Bypass; Ghrelin; Glucagon-Like Peptide 1; Insulin; Islet Amyloid Polypeptide; Leptin; Male; Obesity; Peptide YY; Postprandial Period; Rats; Rats, Sprague-Dawley; Time Factors | 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 |
Sensitivity to the satiating effects of exendin 4 is decreased in obesity-prone Osborne-Mendel rats compared to obesity-resistant S5B/Pl rats.
Osborne-Mendel (OM) rats are prone to obesity when fed a high-fat diet, whereas S5B/Pl (S5B) rats are resistant to diet-induced obesity when fed the same diet. OM rats have a decreased satiation response to fatty acids infused in the gastrointestinal tract, compared to S5B rats. One possible explanation is that OM rats are less sensitive to the satiating hormone, glucagon-like peptide 1 (GLP-1). GLP-1 is produced in the small intestine and is released in response to a meal. The current experiments examined the role of GLP-1 in OM and S5B rats.. Experiment 1 examined preproglucagon mRNA expression in the ileum of OM and S5B rats fed a high-fat (55% kcal) or low-fat (10% kcal) diet. Experiment 2 investigated the effects of a 2 h high-fat meal after a 24 h fast in OM and S5B rats on circulating GLP-1 (active) levels. Experiment 3 examined the effects of exendin-4 (GLP-1 receptor agonist) administration on the intake of a high-fat or a low-fat diet in OM and S5B rats.. Preproglucagon mRNA levels were increased in the ileum of OM rats compared to S5B rats and were increased by high-fat diet in OM and S5B rats. OM and S5B rats exhibited a similar meal-initiated increase in circulating GLP-1 (active) levels. Exendin-4 dose dependently decreased food intake to a greater extent in S5B rats compared to OM rats. The intake of low-fat diet, compared to the intake of high-fat diet, was more sensitive to the effects of exendin-4 in these strains.. These results suggest that though OM and S5B rats have similar preproglucagon mRNA expression in the ileum and circulating GLP-1 levels, OM rats are less sensitive to the satiating effects of GLP-1. Therefore, dysregulation of the GLP-1 system may be a mechanism through which OM rats overeat and gain weight. Topics: Animals; Dietary Fats; Energy Intake; Exenatide; Gene Expression Regulation; Glucagon-Like Peptide 1; Male; Obesity; Peptides; Proglucagon; Rats; RNA, Messenger; Satiation; Venoms; Weight Gain | 2010 |
Cholestyramine reverses hyperglycemia and enhances glucose-stimulated glucagon-like peptide 1 release in Zucker diabetic fatty rats.
Bile acid sequestrants (BAS) have shown antidiabetic effects in both humans and animals but the underlying mechanism is not clear. In the present study, we evaluated cholestyramine in Zucker diabetic fatty (ZDF) rats. Although control ZDF rats had continuous increases in blood glucose and hemoglobin A1c (HbA1c) and serum glucose and a decrease in serum insulin throughout a 5-week study, the cholestyramine-treated ZDF rats showed a dose-dependent decrease and normalization in serum glucose and HbA1c. An oral glucose tolerance test showed a significant increase in glucose-stimulated glucagon-like peptide 1 (GLP-1), peptide YY (PYY), and insulin release in rats treated with cholestyramine. Quantitative analysis of gene expression indicated that cholestyramine treatment decreased farnesoid X receptor (FXR) activity in the liver and the intestine without liver X receptor (LXR) activation in the liver. Moreover, a combination of an FXR agonist with cholestyramine did not reduce the antihyperglycemic effect over cholestyramine alone, suggesting that the FXR-small heterodimer partner-LXR pathway was not required for the glycemic effects of cholestyramine. In summary, our results demonstrated that cholestyramine could completely reverse hyperglycemia in ZDF rats through improvements in insulin sensitivity and pancreatic beta-cell function. Enhancement in GLP-1 and PYY secretion is an important mechanism for BAS-mediated antidiabetic efficacy. Topics: Animals; Blood Glucose; Cholestyramine Resin; Diabetes Mellitus, Experimental; Gene Expression; Glucagon-Like Peptide 1; Glucose Tolerance Test; Glycated Hemoglobin; Hypoglycemic Agents; Insulin; Insulin Resistance; Intestinal Mucosa; Liver; Liver X Receptors; Male; Obesity; Orphan Nuclear Receptors; Peptide YY; Rats; Rats, Zucker; Receptors, Cytoplasmic and Nuclear | 2010 |
Long-term characterization of the diet-induced obese and diet-resistant rat model: a polygenetic rat model mimicking the human obesity syndrome.
The availability of useful animal models reflecting the human obesity syndrome is crucial in the search for novel compounds for the pharmacological treatment of obesity. In the current study, we have performed an extensive characterization of the obesity syndrome in a polygenetic animal model, namely the selectively bred diet-induced obese (DIO) and diet-resistant (DR) rat strains. We show that they constitute useful models of the human obesity syndrome. DIO and DR rats were fed either a high-energy (HE) or a standard chow (Chow) diet from weaning to 9 months of age. Metabolic characterization including blood biochemistry and glucose homeostasis was examined at 2, 3, 6, and 9 months of age. Furthermore, in 6-month-old HE-fed DIO rats, the anti-obesity effects of liraglutide and sibutramine were examined in a 28-day study. Only HE-fed DIO rats developed visceral obesity, hyperleptinemia, hyperinsulinemia, and dyslipidemia, and showed a worsening of glucose tolerance over time. In line with the hyperlipidemic profile, a severe hepatic fat infiltration was observed in DIO rats at 6 months of age. The effects of liraglutide and sibutramine were tested in 6-month-old DIO rats. Both compounds effectively reduced food intake and body weight in DIO rats. Liraglutide furthermore improved glucose tolerance when compared with sibutramine. Our data highlights the usefulness of a polygenetic animal model for screening of compounds affecting food intake, body weight, and glucose homeostasis. Furthermore, the results underscore the effectiveness of GLP-1 mimetics both as anti-diabetes and anti-obesity agents. Topics: Analysis of Variance; Animals; Appetite Depressants; Blood Glucose; Cyclobutanes; Diet; Disease Models, Animal; Eating; Enzyme-Linked Immunosorbent Assay; Feeding Behavior; Glucagon-Like Peptide 1; Insulin; Insulin Resistance; Leptin; Liraglutide; Metabolic Syndrome; Obesity; Rats; Rats, Sprague-Dawley | 2010 |
Metformin reduces body weight gain and improves glucose intolerance in high-fat diet-fed C57BL/6J mice.
In an acute treatment experiment, metformin (150, 300 mg/kg, per os (p.o.)) markedly reduced the consumption of a high-fat diet (HFD) (45 kcal% fat-containing diet) for 2 h after the HFD was given to the fasted male C57BL/6J (B6) mice. In addition, metformin at a higher dose increased plasma active glucagon-like peptide-1 (GLP-1) levels at 1 h after the HFD was given. On the other hand, pioglitazone (12 mg/kg, p.o.) slightly increased the food intake but did not affect active GLP-1 levels when given at 6 and 12 mg/kg, p.o. In a long-team experiment for 9 weeks, metformin treatment (0.25, 0.5% in the HFD) resulted in reduction of body weight gain and HFD intake. When wet weights of various body fat pads of each mouse were measured at 9 weeks after treatment, metformin markedly decreased these weights. However, pioglitazone treatment (0.01, 0.02% in the HFD) did not have obvious effects on these parameters. Oral glucose tolerance test was carried out after 20-h fasting at 4 weeks post-treatment. Whereas metformin treatment (0.25, 0.5%) markedly improved glucose intolerance, pioglitazone treatment (0.02%) slightly improved this parameter. At 9 weeks, both metformin and pioglitazone markedly improved hyperglycemia and hyperinsulinemia. Metformin treatment also improved hyperleptinemia, whereas pioglitazone was ineffective. These results indicate that metformin reduces body weight gain and improves glucose intolerance in HFD-induced obese diabetic B6 mice. Topics: Animals; Blood Glucose; Body Weight; Dietary Fats; Energy Intake; Glucagon-Like Peptide 1; Glucose Intolerance; Glucose Tolerance Test; Hyperglycemia; Hyperinsulinism; Hypoglycemic Agents; Insulin; Leptin; Male; Metformin; Mice; Mice, Inbred C57BL; Obesity; Pioglitazone; Thiazolidinediones; Weight Gain | 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 |
[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 |
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 |
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 |
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 |
Changes in satiety hormones and expression of genes involved in glucose and lipid metabolism in rats weaned onto diets high in fibre or protein reflect susceptibility to increased fat mass in adulthood.
Risk of developing obesity and diabetes may be influenced by the nutritional environment early in life. We examined the effects of high fibre or protein diets on satiety hormones and genes involved in glucose and lipid metabolism during postnatal development and on adult fat mass. At 21 days of age, Wistar rat pups were weaned onto control (C), high fibre (HF) or high protein (HP) diet. Tissue and blood were collected at 7, 14, 21, 28 and 35 days after birth. A second group of rats consumed the weaning diets until 4 months when they were switched to a high fat-high sugar diet for 6 weeks, after which body and fat mass and plasma glucose were determined. In young rats, HF diet increased plasma glucagon-like peptide (GLP-1) compared to C and HP and decreased leptin compared to C at postnatal days 28 and 35. Hepatic fatty acid synthase mRNA was down-regulated by HF and HP compared to C at days 28 and 35. In brown adipose tissue, HF increased uncoupling protein-3 mRNA whereas HP increased mRNA of the inflammatory cytokine interleukin-6. Body weight, fat mass and glycaemia in adult males and fat mass in females were greater after the high fat challenge in rats that consumed the HP diet from weaning. Increasing fibre or protein in postnatal diets causes rapid change in satiety hormone secretion and genes involved in glucose and lipid metabolism which appear to influence fat mass and glycaemia in adulthood, high protein being associated with increased susceptibility to obesity. Topics: Adipose Tissue, Brown; Age Factors; Animals; Body Weights and Measures; Diet; Dietary Fiber; Dietary Proteins; Fatty Acid Synthases; Female; Glucagon-Like Peptide 1; Glucose; Humans; Interleukin-6; Ion Channels; Leptin; Lipid Metabolism; Male; Mitochondrial Proteins; Obesity; Rats; Satiation; Uncoupling Protein 3 | 2009 |
Neuroendocrine, metabolic and pharmacological control of feeding behaviour--closing in on antiobesity treatment.
Topics: Animals; Appetite Depressants; Appetite Regulation; Central Nervous System; Feeding Behavior; Glucagon-Like Peptide 1; Humans; Hypothalamus; Neurosecretory Systems; Obesity; Peptide YY | 2009 |
Multivitamin supplementation of Wistar rats during pregnancy accelerates the development of obesity in offspring fed an obesogenic diet.
The effect of gestational multivitamin supplementation on the development of obesity in rat offspring fed an obesogenic diet was investigated.. Pregnant Wistar rats (n=10 per group) were fed the AIN-93G diet with the recommended vitamin (RV) content or a 10-fold increase (high vitamin, HV). At weaning, 10 males and 10 females, from separate dams, and from each gestational diet group were weaned to the liquid obesogenic diet for 48 weeks post-weaning.. Body weight (BW) was measured weekly, and food intake over 24 h was measured once every 3 weeks for 24 weeks. Every 4 weeks, after an overnight fast, food intake over 1 h was measured 30 min after a gavage of water or glucose. An oral glucose tolerance test (OGTT) was carried out every 3-5 weeks. Post-weaning fasting glucose, insulin, ghrelin, glucagon-like peptide 1 (GLP-1), and systolic blood pressure (SBP) were measured.. No difference in BW at birth or litter size was observed. Males and females from HV dams gained 17% (P<0.05) and 37% (P<0.001) more BW at 48 weeks post-weaning, and consumed 18% (P=0.07) and 20% (P<0.05) more food. One-hour food intake after water and glucose preloads was 27% (P<0.01) and 34% (P<0.05) higher in males from HV dams. Fasting ghrelin and GLP-1 were 27 and 32% higher in males from HV dams at weaning (P<0.05). Blood glucose response to the OGTT was greater in both males and females from HV dams at 13 weeks post-weaning (P<0.05), and the insulin resistance index was 76 and 43% higher in females from HV dams at 14 and 28 weeks post-weaning (P<0.05). SBP was 23 and 16% higher at 44 weeks post-weaning in male and females (P<0.01).. High multivitamin intake during pregnancy increases the phenotypic expression of obesity and components of the metabolic syndrome in both female and male rats fed an obesogenic diet. Topics: Animals; Animals, Newborn; Blood Glucose; Body Weight; Diet; Female; Glucagon-Like Peptide 1; Glucose Tolerance Test; Male; Maternal Nutritional Physiological Phenomena; Obesity; Phenotype; Pregnancy; Prenatal Exposure Delayed Effects; Rats; Rats, Wistar; Vitamins; Weaning | 2009 |
Chronic administration of voglibose, an alpha-glucosidase inhibitor, increases active glucagon-like peptide-1 levels by increasing its secretion and decreasing dipeptidyl peptidase-4 activity in ob/ob mice.
Administration of an alpha-glucosidase inhibitor, voglibose, increases the secretion of glucagon-like peptide (GLP)-1, a key modulator of pancreatic islet hormone secretion and glucose homeostasis. In the present study, novel mechanisms by which voglibose increases active GLP-1 circulation were evaluated. Voglibose (0.001 and 0.005%) was administered in the diet to ob/ob mice for 1 day or 3 to 4 weeks to determine effects on incretin profiles and plasma activity of dipeptidyl peptidase-4 (DPP-4), an enzyme responsible for GLP-1 degradation. Voglibose showed no direct inhibitory effect against DPP-4 in vitro (DPP-4 inhibitor alogliptin, IC(50) < 10 nM). Likewise, 1-day treatment with voglibose did not change plasma DPP-4 activity; however, it increased plasma active GLP-1 by 1.6- to 3.4-fold. After chronic treatment, voglibose stimulated GLP-1 secretion, as evidenced by the 1.3- to 1.5-fold increase in plasma active plus inactive amidated GLP-1 levels. Plasma DPP-4 activity was decreased unexpectedly by 40 to 51%, resulting from reduced plasma DPP-4 concentrations in voglibose-treated mice. Voglibose increased GLP-1 content by 1.5- to 1.6-fold and 1.4- to 1.6-fold in the lower intestine and colon, respectively. The increased GLP-1 content in the colon was associated with elevated expression of gut glucagon gene. Chronic treatment with voglibose resulted in 1.9- to 4.1-fold increase in active GLP-1 circulation, which was higher than 1-day treatment. A similar treatment with pioglitazone (0.03%), an insulin sensitizer, did not affect plasma DPP-4 activity or GLP-1 levels. These results suggest that increased GLP-1 secretion, decreased DPP-4 activity, and increased gut GLP-1 content may have contributed to increased active GLP-1 circulation after chronic treatment with voglibose in a glucose control-independent manner in ob/ob mice. Topics: Animals; Blood Glucose; Diabetes Mellitus, Experimental; Dipeptidyl Peptidase 4; Dipeptidyl-Peptidase IV Inhibitors; Dose-Response Relationship, Drug; Gene Expression; Glucagon; Glucagon-Like Peptide 1; Glycoside Hydrolase Inhibitors; Hypoglycemic Agents; Inositol; Intestinal Mucosa; Male; Mice; Mice, Inbred C57BL; Mice, Obese; Obesity; Time Factors | 2009 |
Serum bile acids are higher in humans with prior gastric bypass: potential contribution to improved glucose and lipid metabolism.
The multifactorial mechanisms promoting weight loss and improved metabolism following Roux-en-Y gastric bypass (GB) surgery remain incompletely understood. Recent rodent studies suggest that bile acids can mediate energy homeostasis by activating the G-protein coupled receptor TGR5 and the type 2 thyroid hormone deiodinase. Altered gastrointestinal anatomy following GB could affect enterohepatic recirculation of bile acids. We assessed whether circulating bile acid concentrations differ in patients who previously underwent GB, which might then contribute to improved metabolic homeostasis. We performed cross-sectional analysis of fasting serum bile acid composition and both fasting and post-meal metabolic variables, in three subject groups: (i) post-GB surgery (n = 9), (ii) without GB matched to preoperative BMI of the index cohort (n = 5), and (iii) without GB matched to current BMI of the index cohort (n = 10). Total serum bile acid concentrations were higher in GB (8.90 +/- 4.84 micromol/l) than in both overweight (3.59 +/- 1.95, P = 0.005, Ov) and severely obese (3.86 +/- 1.51, P = 0.045, MOb). Bile acid subfractions taurochenodeoxycholic, taurodeoxycholic, glycocholic, glycochenodeoxycholic, and glycodeoxycholic acids were all significantly higher in GB compared to Ov (P < 0.05). Total bile acids were inversely correlated with 2-h post-meal glucose (r = -0.59, P < 0.003) and fasting triglycerides (r = -0.40, P = 0.05), and positively correlated with adiponectin (r = -0.48, P < 0.02) and peak glucagon-like peptide-1 (GLP-1) (r = 0.58, P < 0.003). Total bile acids strongly correlated inversely with thyrotropic hormone (TSH) (r = -0.57, P = 0.004). Together, our data suggest that altered bile acid levels and composition may contribute to improved glucose and lipid metabolism in patients who have had GB. Topics: Adiponectin; Adult; Bile Acids and Salts; Biomarkers; Blood Glucose; Body Mass Index; Case-Control Studies; Cross-Sectional Studies; Fasting; Female; Gastric Bypass; Glucagon-Like Peptide 1; Humans; Male; Middle Aged; Obesity; Postprandial Period; Severity of Illness Index; Thyrotropin; Treatment Outcome; Triglycerides; Up-Regulation | 2009 |
Incretin hormone secretion in women with polycystic ovary syndrome: roles of obesity, insulin sensitivity, and treatment with metformin.
In normal subjects, the incretin hormones glucagon-like peptide-1 (GLP-1) and glucose-dependent insulinotropic polypeptide (GIP) are responsible for 70% of the insulin response during a meal; but in diabetic subjects and other insulin-resistant conditions, the incretin effect is impaired. Polycystic ovary syndrome (PCOS) is associated with insulin resistance, and the pathophysiologic mechanisms behind PCOS resemble those of type 2 diabetes mellitus; therefore, women with PCOS may have alterations in the incretin hormone response. Metformin is widely used in the treatment of both type 2 diabetes mellitus and PCOS. Metformin may exert some of its effect on glucose metabolism by increasing GLP-1 biosynthesis and secretion and thereby increasing the incretin effect. The objective of the study was to measure incretin hormone secretion in women with PCOS and to evaluate the effect of metformin treatment. Cross-sectional comparison of 40 women with PCOS (19 lean and 21 obese) and 26 healthy control women (9 lean and 17 obese) and longitudinal evaluation of the effects of 8 months of metformin 1000 mg twice daily in women with PCOS were performed. Plasma concentrations of GIP and GLP-1 were determined frequently during a 75-g glucose tolerance test, and insulin sensitivity was evaluated by the euglycemic hyperinsulinemic clamp. The incretin hormone response did not differ between subjects with and without PCOS. Subgroup analysis showed lower GIP (area under the curve [AUC]) levels in obese women with PCOS compared with obese control women (P < .05) and compared with lean women with PCOS (P < .05). Metformin increased GIP (AUC) and GLP-1 (AUC) in lean women with PCOS (P < .05), and a similar trend was seen in the obese women (P = .07). The GIP secretion is attenuated in obese women with PCOS, whereas treatment with metformin increases the levels of both GIP and GLP-1 in women with PCOS. Topics: Adult; Blood Glucose; Cross-Sectional Studies; Female; Gastric Inhibitory Polypeptide; Glucagon-Like Peptide 1; Glucose; Glucose Clamp Technique; Glucose Tolerance Test; Humans; Hypoglycemic Agents; Insulin; Insulin Resistance; Longitudinal Studies; Metformin; Obesity; Polycystic Ovary Syndrome | 2009 |
Direct control of peripheral lipid deposition by CNS GLP-1 receptor signaling is mediated by the sympathetic nervous system and blunted in diet-induced obesity.
We investigated a possible role of the central glucagon-like peptide (GLP-1) receptor system as an essential brain circuit regulating adiposity through effects on nutrient partitioning and lipid metabolism independent from feeding behavior. Both lean and diet-induced obesity mice were used for our experiments. GLP-1 (7-36) amide was infused in the brain for 2 or 7 d. The expression of key enzymes involved in lipid metabolism was measured by real-time PCR or Western blot. To test the hypothesis that the sympathetic nervous system may be responsible for informing adipocytes about changes in CNS GLP-1 tone, we have performed direct recording of sympathetic nerve activity combined with experiments in genetically manipulated mice lacking beta-adrenergic receptors. Intracerebroventricular infusion of GLP-1 in mice directly and potently decreases lipid storage in white adipose tissue. These effects are independent from nutrient intake. Such CNS control of adipocyte metabolism was found to depend partially on a functional sympathetic nervous system. Furthermore, the effects of CNS GLP-1 on adipocyte metabolism were blunted in diet-induced obese mice. The CNS GLP-1 system decreases fat storage via direct modulation of adipocyte metabolism. This CNS GLP-1 control of adipocyte lipid metabolism appears to be mediated at least in part by the sympathetic nervous system and is independent of parallel changes in food intake and body weight. Importantly, the CNS GLP-1 system loses the capacity to modulate adipocyte metabolism in obese states, suggesting an obesity-induced adipocyte resistance to CNS GLP-1. Topics: Adipose Tissue; Analysis of Variance; Animals; Body Composition; Central Nervous System; Eating; Energy Metabolism; Glucagon-Like Peptide 1; Glucagon-Like Peptide-1 Receptor; Lipid Metabolism; Male; Mice; Mice, Inbred C57BL; Mice, Knockout; Motor Activity; Obesity; Peptide Fragments; Receptors, Adrenergic, beta; Receptors, Glucagon; Signal Transduction; Sympathetic Nervous System; Time Factors | 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 |
A new glucagon and GLP-1 co-agonist eliminates obesity in rodents.
We report the efficacy of a new peptide with agonism at the glucagon and GLP-1 receptors that has potent, sustained satiation-inducing and lipolytic effects. Selective chemical modification to glucagon resulted in a loss of specificity, with minimal change to inherent activity. The structural basis for the co-agonism appears to be a combination of local positional interactions and a change in secondary structure. Two co-agonist peptides differing from each other only in their level of glucagon receptor agonism were studied in rodent obesity models. Administration of PEGylated peptides once per week normalized adiposity and glucose tolerance in diet-induced obese mice. Reduction of body weight was achieved by a loss of body fat resulting from decreased food intake and increased energy expenditure. These preclinical studies indicate that when full GLP-1 agonism is augmented with an appropriate degree of glucagon receptor activation, body fat reduction can be substantially enhanced without any overt adverse effects. Topics: Adipose Tissue; Amino Acid Sequence; Animals; Body Weight; Cyclic AMP; Eating; Energy Metabolism; Glucagon-Like Peptide 1; Glucose Tolerance Test; Mice; Mice, Obese; Models, Molecular; Molecular Sequence Data; Obesity; Peptides, Cyclic; Polyethylene Glycols; Protein Conformation; Receptors, Glucagon | 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 |
Clozapine and quetiapine acutely reduce glucagon-like peptide-1 production and increase glucagon release in obese rats: implications for glucose metabolism and food choice behaviour.
Second generation antipsychotic drug (SGA) treatment is associated with detrimental effects on glucose metabolism which is often attributed to the development of obesity and insulin resistance. However, we have recently demonstrated that clozapine and quetiapine also have direct effects of glucose metabolism in animals. This study compares clozapine and quetiapine and investigates the effects of these on the development of obesity and the direct effects of these drugs on glucose metabolism compared with those caused by the obesity per se.. Three groups of male Sprague-Dawley rats were fed a high fat/high sugar diet to induce obesity while another three groups were fed a chow diet. One group on each diet was injected daily with vehicle, clozapine or quetiapine and effects on glucose metabolism were monitored.. Clozapine and quetiapine treatment did not directly cause obesity or potentiate diet induced obesity but did induce a preference for the high fat/high sugar diet. Neither drug caused a impairment in insulin tolerance over that caused by obesity but both drugs acutely induced impairments in glucose tolerance that were additive with the effects induced by the diet induced obesity. Both drugs caused increases in glucagon levels and a suppression of GLP-1. We investigated two strategies for restoring GLP-1 signalling. The DPP-IV inhibitor sitagliptin only partially restored GLP-1 levels and did not overcome the deleterious effects on glucose tolerance whereas the GLP-1 receptor agonist exendin-4 normalised both glucagon levels and glucose metabolism.. Our findings indicate that the clozapine and quetiapine induced impairments in glucose tolerance in rats are independent of insulin resistance caused by obesity and that these defects are linked with a suppression of GLP-1 levels. These studies suggest the need to perform follow up studies in humans to determine whether clozapine and quetiapine induce acute derangements in glucose metabolism and whether GLP-1 replacement therapy might be the most appropriate therapeutic strategy for treating derangements in glucose metabolism in subjects taking these drugs. Topics: Analysis of Variance; Animals; Antipsychotic Agents; Body Composition; Body Weight; Clozapine; Dibenzothiazepines; Dietary Fats; Disease Models, Animal; Eating; Exenatide; Food Preferences; Gene Expression Regulation; Glucagon; Glucagon-Like Peptide 1; Glucose; Glucose Tolerance Test; Hypoglycemic Agents; Insulin Resistance; Male; Obesity; Peptides; Pyrazines; Quetiapine Fumarate; Rats; Rats, Sprague-Dawley; Sitagliptin Phosphate; Triazoles; Venoms | 2009 |
Entero-insular axis in children with simple obesity.
The entero-insular axis plays an important role in generation of satiety signal. Thus, disturbances in this axis can influence the path to a simple obesity. THE AIM OF THE STUDY was to assess the function of the hormonal part of the entero-insular axis in children with simple obesity.. Group of 13 girls with the simple obesity was analyzed and the results were compared with results taken in the control group of 10 healthy girls. Each girl was examined for the oral glucose tolerance and standard meal tests. Blood was collected before stimulation and after 15, 30, 60 and 120 min. Concentrations of insulin, glucagon, pancreatic polypeptide, cholecystokinin, gastric inhibitory peptide (GIP) and glucagon-like peptide 1 (GLP-1) were determined with radioimmunoassay. Fasted and postprandial levels of the peptides as well as their integrated outputs were measured.. The results indicated that the disturbances in th entero-insular axis were limited to hyperinsulinaemia and changes in secretion of cholecystokinin (CCK) and GLP-1 in obese subjects. The integrated output of CCK in obese girls was significantly higher (p<0.001) than in control group but exclusively after the meal test. Mean values of the integrated output of GLP-1 in both tests were significantly higher in the control group than in the obese girls (oral glucose tolerance test- OGTT: p<0.001; meal: p<0.05). After OGTT and test meal, neither plasma concentrations of glucagon, pancreatic polypeptide nor GIP differed in the obese girl and control groups.. Low postprandial level of GLP-1 in obese children seems to be responsible for excessive ingestion of food and a weaker inhibition of gastric emptying, both resulting in obesity. Topics: Adolescent; Cholecystokinin; Female; Glucagon-Like Peptide 1; Glucose Tolerance Test; Humans; Obesity; Satiety Response | 2009 |
Neurogenin 3-specific dipeptidyl peptidase-2 deficiency causes impaired glucose tolerance, insulin resistance, and visceral obesity.
The control of glucose metabolism is a complex process, and dysregulation at any level can cause impaired glucose tolerance and insulin resistance. These two defects are well-known characteristics associated with obesity and onset of type 2 diabetes. Here we introduce the N-terminal dipeptidase, DPP2, as a novel regulator of the glucose metabolism. We generated mice with a neurogenin 3 (NGN3)-specific DPP2 knockdown (kd) to explore a possible role of DPP2 in maintaining metabolic homeostasis. These mice spontaneously developed hyperinsulinemia, glucose intolerance, and insulin resistance by 4 months of age. In addition, we observed an increase in food intake in DPP2 kd mice, which was associated with a significant increase in adipose tissue mass and enhanced liver steatosis but no difference in body weight. In accordance with these findings, the mutant mice had a higher rate of respiratory exchange than the control littermates. This phenotype was exacerbated with age and when challenged with a high-fat diet. We report, for the first time, that DPP2 enzyme activity is essential for preventing hyperinsulinemia and maintaining glucose homeostasis. Interestingly, the phenotype of NGN3-DPP2 kd mice is opposite that of DPP4 knockout mice with regard to glucose metabolism, namely the former have normal glucagon-like peptide 1 levels but present with glucose intolerance, whereas the latter have increased glucagon-like peptide 1, which is accompanied by augmented glucose tolerance. Topics: Adipose Tissue; Animals; Basic Helix-Loop-Helix Transcription Factors; Blood Glucose; Dipeptidyl-Peptidases and Tripeptidyl-Peptidases; Eating; Fasting; Fatty Liver; Female; Fluorescent Antibody Technique; Glucagon-Like Peptide 1; Glucose Intolerance; Insulin; Insulin Resistance; Male; Mice; Mice, Knockout; Mice, Transgenic; Nerve Tissue Proteins; Obesity | 2009 |
Gastrointestinal hormones and weight management.
Topics: Anti-Obesity Agents; Dose-Response Relationship, Drug; Feeding Behavior; Glucagon-Like Peptide 1; Half-Life; Humans; Lactones; Liraglutide; Obesity; Orlistat; Weight Loss | 2009 |
Immunomodulatory properties of two wheat bran fractions - aleurone-enriched and crude fractions - in obese mice fed a high fat diet.
Several data suggest that fermentable dietary fibers could play a role in the control of obesity and associated metabolic disorders. In mice, dietary fructans, which are extensively fermented in caeco-colon by bifidobacteria, decrease fat mass development and modulate gastrointestinal peptides involved in the control of food intake (namely glucagon-like peptide (GLP)-1). The aim of this study was to compare the effect of two cereal bran fractions isolated from wheat - aleurone-enriched and crude fractions - in a nutritional model of obesity. In a first experiment, we confirmed that 2 weeks of treatment with a high fat (HF) diet is sufficient to exhibit glucose intolerance and to increase adiposity in mice. In the second experiment, mice were fed a HF or a HF diet enriched with 10% wheat bran fractions during 3 weeks. None of the wheat bran fractions modified body weight, adipose tissue mass, glucose or lipid homeostasis. Wheat bran fractions increased bifidobacteria and lactobacilli in the caecal content without any effect on caecal enlargement and on GLP-1 precursor expression in the colon. Furthermore, wheat bran fractions decreased circulating interleukin 6 (IL-6) and CD68 mRNA in the visceral adipose tissue, suggesting a decrease in recruited-tissue macrophages. We propose that specific and early immunomodulatory properties of cereal products with prebiotic properties, may occur in obese mice independently of extensive gut fermentation. Topics: Animals; Complex Mixtures; Diet; Dietary Fiber; Fats; Glucagon-Like Peptide 1; Mice; Mice, Obese; Obesity | 2008 |
A gut feeling for obesity: 7TM sensors on enteroendocrine cells.
Enteroendocrine cells, which secrete peptide hormones in response to sensation of food and gut microbiota products, can now be genetically tagged, isolated, cultured, and characterized for expression of the elusive chemosensors, as shown in publications in PNAS (Samuel et al., 2008) and in this issue (Reimann et al., 2008). Topics: Bile Acids and Salts; Enteroendocrine Cells; Gastrointestinal Hormones; Glucagon-Like Peptide 1; Humans; Obesity; Receptors, Cell Surface; Receptors, G-Protein-Coupled; Receptors, Lysophosphatidic Acid | 2008 |
Physiological effects of dietary fructans extracted from Agave tequilana Gto. and Dasylirion spp.
Recent data reported that inulin-type fructans extracted from chicory roots regulate appetite and lipid/glucose metabolism, namely, by promoting glucagon-like peptide-1 (GLP-1) production in the colon. The Agave genus growing in different regions of Mexico also contains important amounts of original fructans, with interesting nutritional and technological properties, but only few data report their physiological effect when added in the diet. Therefore, we decided to evaluate in parallel the effect of supplementation with 10 % agave or chicory fructans on glucose and lipid metabolism in mice. Male C57Bl/6J mice were fed a standard (STD) diet or diet supplemented with Raftilose P95 (RAF), fructans from Agave tequilana Gto. (TEQ) or fructans from Dasylirion spp. (DAS) for 5 weeks. The body weight gain and food intake in mice fed fructans-containing diets were significantly lower than the ones of mice fed the STD diet, TEQ leading to the lowest value. Serum glucose and cholesterol were similarly lower in all fructans-fed groups than in the STD group and correlated to body weight gain. Only RAF led to a significant decrease in serum TAG. As previously shown for RAF, the supplementation with agave fructans (TEQ and DAS) induced a higher concentration of GLP-1 and its precursor, proglucagon mRNA, in the different colonic segments, thus suggesting that fermentable fructans from different botanical origin and chemical structure are able to promote the production of satietogenic/incretin peptides in the lower part of the gut, with promising effects on glucose metabolism, body weight and fat mass development. Topics: Agave; Animals; Blood Glucose; Cecum; Cholesterol; Colon; Defecation; Dietary Supplements; Eating; Epididymis; Fructans; Glucagon-Like Peptide 1; Liliaceae; Lipid Metabolism; Liver; Male; Mice; Mice, Inbred C57BL; Obesity; Organ Size; Proglucagon; RNA, Messenger; Triglycerides; Weight Gain | 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 |
Upregulation of the brainstem preproglucagon system in the obese Zucker rat.
A group of neurons in the caudal nucleus of the solitary tract (NTS) processes preproglucagon to glucagon-like peptide 1 (GLP-1), GLP-2 and oxyntomodulin. Whereas the anorectic capacity of all three neuropeptides has been demonstrated, only relatively little is known of preproglucagon mRNA regulation in the brain stem. Using in situ hybridization and fluorescence immunohistochemistry, we examined hindbrain preproglucagon expression in lean and obese Zucker rats under different metabolic perturbations. First, the effect of an acute 48-h fast was examined in male Sprague-Dawley as well as in lean and obese Zucker rats. Whereas fasting had no effect on preproglucagon expression in either genotype, mRNA levels were strongly up regulated in obese Zucker rats. Using a direct immunostaining procedure and a monoclonal GLP-2 antibody, we found a doubling of the immunofluorescence signal emanating from the preproglucagon neurons in caudal brainstem suggesting that indeed the high mRNA levels observed using in situ hybridization histochemistry also reflect a higher translational activity. To investigate the effects of long-term body weight perturbations, lean and obese Zucker rats were either free-fed, voluntarily overfed (chocolate spread enriched chow) or food restricted for 35 days. Preproglucagon levels remained high in the obese Zucker rats irrespective of diet. Finally, in order to functionally validate the apparent hyperactivity in the preproglucagon system in the Zucker rat, we examined the effect of central GLP-1 receptor blockade. ICV administration of 20 microg of the GLP-1 receptor antagonist Des-His-Exendin-9-39 in the morning increased 4-h food intake in obese but not in lean Zucker rats, pointing to an increased activity in central preproglucagon containing pathways in leptin receptor deficient rats. Our data suggest that the preproglucagon neurons in the brainstem are influenced by leptin signaling and point to a role of preproglucagon neurons in the integration of metabolic signals that occurs in the nucleus of the solitary tract. Topics: Animals; Appetite Regulation; Brain Stem; Caloric Restriction; Circadian Rhythm; Fluorescent Antibody Technique; Food Deprivation; Food, Formulated; Glucagon; Glucagon-Like Peptide 1; Glucagon-Like Peptide-1 Receptor; In Situ Hybridization; Leptin; Male; Obesity; Proglucagon; Protein Biosynthesis; Rats; Rats, Sprague-Dawley; Rats, Zucker; Receptors, Glucagon; Receptors, Leptin; RNA, Messenger; Solitary Nucleus; Up-Regulation | 2008 |
Influence of sleeve gastrectomy on several experimental models of obesity: metabolic and hormonal implications.
Ghrelin is an important factor in the regulation of intake. Most ghrelin is synthesized in the gastric fundus, but this is not the only location. The aim of this experimental study was to analyze the effect of sleeve gastrectomy (removing fundus) on the volume of intake in four experimental models and determine how this relates to changes in weight, plasmatic levels of glycemia, ghrelin, GLP-1, and insulin.. Sleeve gastrectomy was performed on four experimental models: (1) non-obesity; (2) exogenous obesity caused by excessive calorie intake; (3) genetically determined obesity (Zucker rats); and (4) genetically determined obesity and type 2 diabetes mellitus (Zucker diabetic fatty; ZDF rats). Model 2 had a control group on which sleeve gastrectomy was not performed.. In the non-obese group, there were few changes after intervention, but in model 2, sleeve gastrectomy led to normalization of weight and endocrine-metabolic parameters that were the same as those for non-obese rats. The exception was for GLP-1, which has an anorexigenic effect: GLP-1 remained higher. In Zucker rats, sleeve gastrectomy had a slight effect on all parameters. In ZDF rats, sleeve gastrectomy led to a reduction in intake and a stabilization of weight.. Sleeve gastrectomy is a very good option for exogenous obesity. Normalization of hormonal levels led us to find an extragastric ghrelin production. Topics: Animals; Biomarkers; Blood Glucose; Disease Models, Animal; Gastrectomy; Ghrelin; Glucagon-Like Peptide 1; Insulin; Obesity; Rats; Rats, Sprague-Dawley; Rats, Zucker; Weight Loss | 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 |
Glucose tolerance, lipids, and GLP-1 secretion in JCR:LA-cp rats fed a high protein fiber diet.
We have shown that individually, dietary fiber and protein increase secretion of the anorexigenic and insulinotropic hormone, glucagon-like peptide-1 (GLP-1).. Our objective was to combine, in one diet, high levels of fiber and protein to maximize GLP-1 secretion, improve glucose tolerance, and reduce weight gain.. Lean (+/?) and obese (cp/cp) male James C Russell corpulent (JCR:LA-cp) rats lacking a functional leptin receptor were fed one of four experimental diets (control, high protein (HP), high fiber (HF, prebiotic fiber inulin), or combination (CB)) for 3 weeks. An oral glucose tolerance test (OGTT) was performed to evaluate plasma GLP-1, insulin and glucose. Plasma lipids and intestinal proglucagon mRNA expression were determined.. Energy intake was lower with the HF diet in lean and obese rats. Weight gain did not differ between diets. Higher colonic proglucagon mRNA in lean rats fed a CB diet was associated with higher GLP-1 secretion during OGTT. The HP diet significantly reduced plasma glucose area under the curve (AUC) during OGTT in obese rats, which reflected both an increased GLP-1 AUC and higher fasting insulin. Diets containing inulin resulted in the lowest plasma triglyceride and total cholesterol levels.. Overall, combining HP with HF in the diet increased GLP-1 secretion in response to oral glucose, but did not improve glucose tolerance or lipid profiles more than the HF diet alone did. We also suggest that glycemic and insulinemic response to prebiotics differ among rat models and future research work should examine their role in improving glucose tolerance in diet-induced vs. genetic obesity with overt hyperleptinemia. Topics: Animals; Blood Glucose; Body Weight; Dietary Fiber; Dietary Proteins; Disease Models, Animal; Duodenum; Glucagon-Like Peptide 1; Glucose Tolerance Test; Insulin Resistance; Inulin; Jejunum; Lipids; Male; Obesity; Proglucagon; Rats; Rats, Inbred Strains; RNA, Messenger; Weight Gain | 2008 |
GLP-1 and appetite responses to a meal in lean and overweight adolescents following exercise.
Increased physical activity is an integral part of weight loss programs in adolescents. We prospectively investigated the effects of exercise on glucagon-like peptide-1 (GLP-1) concentrations and on appetite markers.. Normal weight (NW) and at risk of overweight/overweight (OW) male adolescents (n = 17/gr) underwent five consecutive days of aerobic exercise (1 h/day). A test meal was administered prior to the first exercise session and 36 hours following the last exercise session. GLP-1 and markers of appetite were assessed.. GLP-1 concentrations over the course of the test meal were lower in OW compared to NW boys (P < 0.05), while fasting GLP-1 concentrations tended to be lower in OW boys (0.05 < P < 0.1). Exercise caused an increase in the acute GLP-1 response to the liquid meal (from 52 to 78%, P = 0.02) that was similar in NW and OW adolescents. OW adolescents expressed greater restraint compared to NW adolescents (three-factor eating questionnaire, TFEQ) and there was a significant correlation between TFEQ for restraint score and BMI s.d. both before and after exercise intervention (P < 0.015). There was no significant correlation between markers of appetite and GLP-1 concentrations.. Lower concentrations of GLP-1, a satiety hormone, in OW compared to NW male adolescents support the theory that GLP-1 plays a role in the etiology of overweight. Whether the greater meal-induced, 0-30 min GLP-1 response following exercise is associated with increased satiety, a potentially beneficial effect of exercise, needs to be evaluated in larger studies. Obesity (2008) 16, 202-204. doi:10.1038/oby.2007.39. Topics: Adolescent; Appetite; Body Mass Index; Exercise; Glucagon-Like Peptide 1; Health Surveys; Humans; Male; Obesity; Overweight; Pain Measurement; Prospective Studies; Satiety Response; Thinness | 2008 |
Differential secretion of satiety hormones with progression of obesity in JCR:LA-corpulent rats.
To characterize the gastrointestinal tract at the onset and in well-established obesity.. Lean (+/?) and obese (cp/cp) male JCR:LA-cp rats lacking a functional leptin receptor were killed at 3.5 weeks and 9 months of age and plasma concentrations of satiety hormones determined. The small intestine, colon, and stomach were measured, weighed, and mRNA levels of satiety genes quantified.. At the onset of obesity, obese rats had greater intestine, colon, and liver mass when adjusted for body weight compared to lean rats. Conversely, adult rats with established obesity had lower intestine and colon mass and length after adjustment for body weight. Early changes in gene expression included decreased ghrelin mRNA levels in stomach and increased peptide YY (PYY) mRNA levels in duodenum of young obese rats. After massive accumulation of adipose tissue had occurred, adult obese rats had increased proglucagon and ghrelin mRNA expression in the proximal intestine. In the distal small intestine, obese rats had lower proglucagon, ghrelin, and PYY mRNA levels. Finally, at the onset and in well-established obesity, obese rats had higher plasma insulin, amylin, glucagon like peptide-1 (GLP-1), and PYY, a finding, with the exception of insulin, unique to this model. Plasma total ghrelin levels were significantly lower at the onset of obesity and established obesity compared to the lean rats.. Several defects are manifested in the obese gut early on in the disease before the accumulation of large excesses of body fat and represent potential targets for early intervention in obesity. Topics: Amyloid; Animals; Body Weight; Colon; Disease Models, Animal; Energy Metabolism; Female; Gastric Mucosa; Gastrointestinal Hormones; Ghrelin; Glucagon-Like Peptide 1; Insulin; Insulin Secretion; Intestine, Small; Islet Amyloid Polypeptide; Liver; Male; Obesity; Peptide YY; Proglucagon; Rats; Rats, Inbred Strains; RNA, Messenger; Satiety Response; Stomach | 2008 |
Oral ingestion of a hydrolyzed gelatin meal in subjects with normal weight and in obese patients: Postprandial effect on circulating gut peptides, glucose and insulin.
Gut hormones [ghrelin, peptide YY (PYY) and glucagon-like peptide-1 (GLP-1)] are an important group of hormones that target appetite control. They are released from endocrine L cells of the small bowel in proportion to the volume, components and calories in a meal. In the current study, 20 g of gelatin (flavored and sweetened) were given to obese patients (n=12) and lean subjects (n=10). Subsequently, plasma samples were collected at-30- minute intervals up to 180 minutes and glucose, insulin, PYY, GLP-1 and ghrelin were assayed using specific and sensitive immunofluorometric and radioimmunoassays. As expected, obese patients had normal serum glucose levels, higher serum insulin, and lower plasma concentration of ghrelin at all times compared to lean subjects. GLP-1 plasma levels were significantly elevated at 60 minutes, peaking at 120 minutes in obese patients and lean subjects. As a consequence, there was a significant rise in serum insulin levels with a significantly higher peak level at 60 min (obese) and 30 min (lean). There were no significant changes in PYY plasma concentrations and no correlation was found between body mass index and concentrations of ghrelin, PYY and GLP-1 in the group of obese patients. In conclusion, a single gelatin meal induces a rise in plasma GLP-1 followed by an increase in serum levels of insulin. These findings may be applied to maximize satiety in obese patients as a means of improving adherence to calorie-controlled diets as well as provide better control of diabetic patients. Topics: Adult; Blood Glucose; Body Mass Index; Case-Control Studies; Female; Gelatin; Ghrelin; Glucagon-Like Peptide 1; Humans; Insulin; Male; Middle Aged; Obesity; Peptide YY; Postprandial Period; Thinness | 2008 |
GLP-1 (9-36) amide, cleavage product of GLP-1 (7-36) amide, is a glucoregulatory peptide.
Glucagon-like peptide-1 (GLP-1) (7-36) amide is a glucoregulatory hormone with insulinotropic and insulinomimetic actions. We determined whether the insulinomimetic effects of GLP-1 are mediated through its principal metabolite, GLP-1 (9-36) amide (GLP-1m).. Glucose turnover during two, 2-h, euglycemic clamps was measured in 12 lean and 12 obese (BMI <25 or >30 kg/m(2)) male and female subject volunteers with normal oral glucose tolerance test. Saline or GLP-1m were infused from 0 to 60 min in each study. Additionally, seven lean and six obese subjects underwent a third clamp in which the GLP-1 receptor (GLP-1R) antagonist, exendin (9-39) amide was infused from -60 to 60 min with GLP-1m from 0 to 60 min.. No glucose infusion was required in lean subjects to sustain euglycemia (glucose clamp) during saline or GLP-1m infusions. However, in obese subjects glucose infusion was necessary during GLP-1m infusion alone in order to compensate for a marked (>50%) inhibition of hepatic glucose production (HGP). Plasma insulin levels remained constant in lean subjects but rose significantly in obese subjects after termination of the peptide infusions. During GLP-1R blockade, infusion of glucose was immediately required upon starting GLP-1m infusions in all subjects due to a more dramatic reduction in HGP, as well as a delayed and modest insulinotropic response.. We conclude that GLP-1m potently inhibits HGP and is a weak insulinotropic agent. These properties are particularly apparent and pronounced in obese but only become apparent in lean subjects during GLP-1 (7-36) receptor blockade. These previously unrecognized antidiabetogenic actions of GLP-1m may have therapeutic usefulness. Topics: Adult; Blood Glucose; Female; Glucagon-Like Peptide 1; Glucagon-Like Peptide-1 Receptor; Glucose Clamp Technique; Glucose Tolerance Test; Humans; Hypoglycemic Agents; Infusions, Parenteral; Insulin; Liver; Male; Middle Aged; Obesity; Peptide Fragments; Peptides; Receptors, Glucagon; 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 |
Liraglutide, a long-acting glucagon-like peptide-1 analog, reduces body weight and food intake in obese candy-fed rats, whereas a dipeptidyl peptidase-IV inhibitor, vildagliptin, does not.
Metabolic effects of the glucagon-like peptide-1 analog liraglutide and the dipeptidyl peptidase-IV inhibitor vildagliptin were compared in rats made obese by supplementary candy feeding. Female Sprague-Dawley rats were randomized to 12-week diets of chow or chow plus candy. The latter were randomized for 12 further weeks to continue their diet while receiving 0.2 mg/kg liraglutide twice daily subcutaneously, 10 mg/kg vildagliptin twice daily orally, or vehicle or to revert to chow-only diet. Energy expenditure was measured, and oral glucose tolerance tests (OGTTs) were performed. Body composition was determined by dual-energy X-ray absorptiometry scanning, and pancreatic beta-cell mass was determined by histology. Candy feeding increased weight, fat mass, and feeding-associated energy expenditure. Liraglutide or reversal to chow diet fully reversed weight and fat gains. Liraglutide was associated with decreased calorie intake and shifted food preference (increased chow/decreased candy consumption). Despite weight loss, liraglutide-treated rats did not decrease energy expenditure compared with candy-fed controls. Vildagliptin affected neither weight, food intake, nor energy expenditure. OGTTs, histology, and blood analyses indirectly suggested that both drugs increased insulin sensitivity. Liraglutide and vildagliptin inhibited obesity-associated increases in beta-cell mass. This was associated with weight and fat mass normalization with liraglutide, but not vildagliptin, where the ratio of beta-cell to body mass was low. Topics: Adamantane; Animals; Body Composition; Body Weight; Candy; Energy Intake; Energy Metabolism; Glucagon-Like Peptide 1; Hypoglycemic Agents; Liraglutide; Nitriles; Obesity; Pancreas; Pyrrolidines; Rats; Rats, Sprague-Dawley; Vildagliptin | 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 |
Fasting glucagon-like peptide-1 and its relation to insulin in obese children before and after weight loss.
To study the relationships between glucagon-like peptide-1 (GLP-1), weight status, insulin, and insulin resistance in the fasting state.. Fasting GLP-1, glucose and insulin concentrations, insulin resistance index as homeostasis model assessment (HOMA), body mass index (BMI), and percentage body fat based on skinfold thickness measurements were determined in 42 obese (median age 11 years) and in 16 lean children of the same age. The HOMA model was used to calculate degree of insulin resistance. Furthermore, the changes in GLP-1, glucose, insulin, and HOMA in the course of 1 year were analyzed in the 42 obese children participating in an obesity intervention.. GLP-1 concentrations did not differ significantly between obese and lean children. In multiple linear regression analyses, GLP-1 was significantly related to insulin (P = 0.028) and HOMA (P = 0.019) but not to glucose, age, sex, pubertal stage, BMI, or percentage body fat. The 15 obese children with substantial weight reduction demonstrated significantly (P < 0.05) decreased GLP-1, insulin, and HOMA levels, whereas these parameters did not change in 27 obese children without substantial weight loss. Changes in GLP-1 correlated significantly with changes in insulin (r = 0.46, P = 0.001) and HOMA (r = 0.28, P = 0.036) but not with changes in glucose, BMI, or percentage of body fat.. In children, fasting GLP-1 concentrations are independent of age, sex, and pubertal stage. Although GLP-1 did not differ between lean and obese children, weight loss was associated with decreasing GLP-1. Inasmuch as GLP-1 levels were related to insulin concentrations in both cross-sectional and longitudinal analyses, we hypothesize a relationship between GLP-1 and insulin in the fasting state. Topics: Child; Cross-Sectional Studies; Fasting; Female; Glucagon-Like Peptide 1; Homeostasis; Humans; Insulin; Insulin Resistance; Longitudinal Studies; Male; Models, Biological; Obesity; Weight Loss | 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 the subchronic antidiabetic effects of DPP IV-resistant GIP and GLP-1 analogues in obese diabetic (ob/ob) mice.
Glucagon-like peptide-1 (GLP-1) and glucose-dependent insulinotropic polypeptide (GIP) are the two key incretin hormones released from the gastrointestinal tract that regulate blood glucose homeostasis through potent insulin secretion. The rapid degradation of GIP and GLP-1 by the ubiquitous enzyme dipeptidyl peptidase IV (DPP IV) renders both peptides noninsulinotropic. However, DPP IV stable agonists, such as N-AcGIP and (Val8)GLP-1, have now been developed. The present study has examined and compared the metabolic effects of subchronic administration of daily i.p. injections of N-AcGIP, (Val8) GLP-1 and a combination of both peptides (all at 25 nmol/kg bw) in obese diabetic (ob/ob) mice. Initial in vitro experiments confirmed the potent insulinotropic properties of N-AcGIP and (Val8)GLP-1 in the clonal pancreatic BRIN BD11 cell line. Subchronic administration of N-AcGIP, (Val8)GLP-1 or combined peptide administration had no significant effects on the body weight, food intake and plasma insulin concentrations. However, all treatment groups had significantly (p < 0.05) decreased plasma glucose levels and improved glucose tolerance by day 14. The effectiveness of the peptide groups was similar, and glucose concentrations were substantially reduced following injection of insulin to assess insulin sensitivity compared to control. These results provide evidence for an improvement of glucose homeostasis following treatment with enzyme-resistant GIP and GLP-1 analogues. Topics: Animals; Blood Glucose; Body Weight; Diabetes Mellitus, Experimental; Dipeptidyl Peptidase 4; Gastric Inhibitory Polypeptide; Glucagon-Like Peptide 1; Glucose Tolerance Test; Homeostasis; Hypoglycemic Agents; Insulin; Insulin Resistance; Mice; Obesity | 2007 |
Decreased basal levels of glucagon-like peptide-1 after weight loss in obese subjects.
Basal glucagon-like peptide-1 (GLP-1) concentrations seem to be attenuated in obese subjects, although statistical significance is unclear. Only a few studies have investigated the effect of weight reduction on GLP-1 concentrations and have found unclear results. The aim of the present study was to determine whether subjects who lose weight on a hypocaloric diet experience the same change in circulating GLP-1 levels as subjects who do not lose weight.. A population of 99 obese nondiabetic outpatients was analyzed in a prospective way. Weight and blood pressure were determined. Basal glucose, C-reactive protein, insulin, total cholesterol, LDL cholesterol, HDL cholesterol, triglycerides, and basal GLP-1 blood levels were measured before and after 3 months of hypocaloric diet. Bipolar impedance examination was performed in all patients to assess body composition. The lifestyle modification program consisted of a hypocaloric diet (1,520 kcal, 52% carbohydrates, 25% lipids and 23% proteins). The exercise program consisted of aerobic exercise for at least 3 times per week (60 min each).. Ninety-nine patients (20 male/79 female) gave informed consent and were enrolled in the study. Fourteen patients (2 male/12 female) did not lose weight (group I: weight increase of 2 +/- 1.1 kg, NS) and 75 patients (18 male/67 female) lost weight (group II, weight loss of 4 +/- 1.6 kg, p < 0.05). Weight, body mass index, fat mass, waist circumference, insulin, HOMA, LDL cholesterol, triglycerides and systolic blood pressure improved in group II, without significant statistical changes in group I. In group I, basal GLP-1 levels remained unchanged (7.4 +/- 3.1 vs. 7.15 +/- 3.6 ng/ml, NS). In group II, GLP-1 levels decreased significantly (8.4%, 6.88 +/- 2.5 vs. 6.3 +/- 2.4 ng/ml, p < 0.05). In the multivariate analysis with a dependent variable (levels of GLP-1 after hypocaloric diet adjusted by age and sex), only insulin levels remained as an independent predictor in the model (F = 5.9; p < 0.05), with an increase of 0.6 ng/ml (CI 95%: 0.1-1.1) in GLP-1 concentrations with each 1-mIU/ml increase of insulin.. Hypocaloric diet decreased GLP-1 levels in patients with weight loss with a significant improvement in anthropometric parameters and cardiovascular risk factors. Nevertheless, patients without weight loss after dietary treatment exhibited unchanged GLP-1 levels. Basal insulin correlates with basal GLP-1. Topics: Adipose Tissue; Anthropometry; Blood Glucose; Body Mass Index; Diet, Reducing; Exercise; Female; Glucagon-Like Peptide 1; Humans; Insulin; Lipid Metabolism; Male; Middle Aged; Obesity; Prospective Studies; Weight Loss | 2007 |
Effects of combined oleoyl-estrone and rimonabant on overweight rats.
Oleoyl-estrone (OE) decreases appetite, maintains energy expediture, induces lipolysis (sparing protein), and decreases cholesterolemia and insulin resistance. Rimonabant (SR141716) is a cannabinoid-receptor inhibitor that decreases appetite and mobilizes fat. We studied whether their combination improves their slimming effects. Male overweight rats received daily gavages of 5.3 mg/kg OE, 10 mg/kg rimonabant, or both drugs during 10 days. Body weight and composition, energy balance, adipose tissue weight, and serum hormones and metabolites were measured. OE halved food intake and maintained energy expenditure at the expense of body fat. Rimonabant effects on appetite and energy balance were less marked, resulting in lower lipid mobilization. OE and rimonabant followed the OE pattern, with no additive or synergic effects. Glycemia was maintained, but OE decreased insulin, GLP-1, and cholesterol, whilst rimonabant increased cholecystokinin and cholesterol, and decreased NEFA. Both drugs decreased leptin and triacylglycerols; ghrelin was unchanged. The results hint at different mechanisms of action of both drugs: we can assume that OE effects do not involve the cannabinoid pathway. OE does not seem to act, either, after 10 days, through the secretion of ghrelin or the intestinal appetite-controlling peptides tested. Topics: Animals; Anti-Obesity Agents; Appetite; Blood Glucose; Cholecystokinin; Cholesterol; Drug Synergism; Drug Therapy, Combination; Eating; Energy Metabolism; Estrone; Fatty Acids, Nonesterified; Ghrelin; Glucagon-Like Peptide 1; Insulin; Leptin; Male; Obesity; Oleic Acids; Overweight; Peptide Hormones; Piperidines; Pyrazoles; Rats; Rats, Wistar; Rimonabant; Triglycerides | 2007 |
Liraglutide, a once-daily human glucagon-like peptide-1 analog, minimizes food intake in severely obese minipigs.
To evaluate the efficacy of liraglutide, a new, stable, once-daily human analog of glucagon-like peptide-1, in a new animal model of obesity.. Liraglutide was administered subcutaneously once daily (7 microg/kg for 7 weeks) to six female obese Göttingen minipigs. Food intake and feeding patterns were monitored using a novel automated feeding system that allowed continuous recording of food intake.. Food intake was strongly suppressed. A steady-state level of reduced food intake was achieved within 3 weeks and was maintained for the remaining 4 weeks of the treatment period. During the 4-week steady-state period with liraglutide treatment, daily food intake was 7.3+/-0.3 megajoule (MJ) compared with 18.4+/-0.6 MJ in the pre-treatment period and 19.2+/-0.5 MJ in the post-treatment period (p<0.001). The food intake in the treatment period was equivalent to the amount of food that would have been offered to normal-weight pigs for maintenance. Body weight decreased 4.3+/-1.2 kg (4% to 5%) during the 7 weeks of treatment and increased 7.0+/-1.0 kg during the 7 weeks of post-treatment (p<0.01). Appetite suppression was quickly reversed within 4 days after termination of liraglutide administration.. Overall, liraglutide was well tolerated and had a profound and persistent anorectic effect that resulted in weight loss. These results, in conjunction with the previously established glucose-lowering efficacy of liraglutide, suggest that the anorectic actions of liraglutide will be very important in clinical trials of both obese patients with type 2 diabetes and obese non-diabetic patients. Topics: Animals; Appetite Depressants; Body Composition; Body Weight; Disease Models, Animal; Energy Intake; Female; Glucagon-Like Peptide 1; Liraglutide; Obesity; Swine; Swine, Miniature | 2007 |
GIP receptor antagonism reverses obesity, insulin resistance, and associated metabolic disturbances induced in mice by prolonged consumption of high-fat diet.
The gut hormone gastric inhibitory polypeptide (GIP) plays a key role in glucose homeostasis and lipid metabolism. This study investigated the effects of administration of a stable and specific GIP receptor antagonist, (Pro(3))GIP, in mice previously fed a high-fat diet for 160 days to induce obesity and related diabetes. Daily intraperitoneal injection of (Pro(3))GIP over 50 days significantly decreased body weight compared with saline-treated controls, with a modest increase in locomotor activity but no change of high-fat diet intake. Plasma glucose, glycated hemoglobin, and pancreatic insulin were restored to levels of chow-fed mice, and circulating triglyceride and cholesterol were significantly decreased. (Pro(3))GIP treatment also significantly decreased circulating glucagon and corticosterone, but concentrations of GLP-1, GIP, resistin, and adiponectin were unchanged. Adipose tissue mass, adipocyte hypertrophy, and deposition of triglyceride in liver and muscle were significantly decreased. These changes were accompanied by significant improvement of insulin sensitivity, meal tolerance, and normalization of glucose tolerance in (Pro(3))GIP-treated high-fat-fed mice. (Pro(3))GIP concentrations peaked rapidly and remained elevated 24 h after injection. These data indicate that GIP receptor antagonism using (Pro(3))GIP provides an effective means of countering obesity and related diabetes induced by consumption of a high-fat, energy-rich diet. Topics: Adipokines; Adipose Tissue; Animals; Anti-Obesity Agents; Blood Glucose; Body Weight; Corticosterone; Dietary Fats; Eating; Gastric Inhibitory Polypeptide; Glucagon; Glucagon-Like Peptide 1; Glucose Intolerance; Incretins; Insulin; Insulin Resistance; Lipids; Liver; Male; Mice; Motor Activity; Muscle, Skeletal; Obesity; Pancreas; Receptors, Gastrointestinal Hormone | 2007 |
Gastric emptying controls type 2 diabetes mellitus.
Topics: Diabetes Mellitus, Type 2; Gastric Emptying; Glucagon-Like Peptide 1; Humans; Obesity | 2007 |
Patients with neuroglycopenia after gastric bypass surgery have exaggerated incretin and insulin secretory responses to a mixed meal.
Hyperinsulinemic hypoglycemia is newly recognized as a rare but important complication after Roux-en-Y gastric bypass (GB). The etiology of the syndrome and metabolic characteristics remain incompletely understood. Recent studies suggest that levels of incretin hormones are increased after GB and may promote excessive beta-cell function and/or growth.. We performed a cross-sectional analysis of metabolic variables, in both the fasting state and after a liquid mixed-meal challenge, in four subject groups: 1) with clinically significant hypoglycemia [neuroglycopenia (NG)] after GB surgery, 2) with no symptoms of hypoglycemia at similar duration after GB surgery, 3) without GB similar to preoperative body mass index of the surgical cohorts, and 4) without GB similar to current body mass index of the surgical cohorts.. Insulin and C-peptide after the liquid mixed meal were both higher relative to the glucose level achieved in persons after GB with NG compared with asymptomatic individuals. Glucagon, glucagon-like peptide 1, and glucose-dependent insulinotropic peptide levels were higher in both post-GB surgical groups compared with both overweight and morbidly obese persons, and glucagon-like peptide 1 was markedly higher in the group with NG. Insulin resistance, assessed by homeostasis model assessment of insulin resistance, the composite insulin sensitivity index, or adiponectin, was similar in both post-GB groups. Dumping score was also higher in both GB groups but did not discriminate between asymptomatic and symptomatic patients. Notably, the frequency of asymptomatic hypoglycemia after a liquid mixed meal was high in post-GB patients.. A robust insulin secretory response was associated with postprandial hypoglycemia in patients after GB presenting with NG. Increased incretin levels may contribute to the increased insulin secretory response. Topics: Adult; Aged; Blood Glucose; Body Mass Index; C-Peptide; Eating; Female; Food; Gastric Bypass; Gastric Inhibitory Polypeptide; Glucagon; Glucagon-Like Peptide 1; Humans; Hypoglycemia; Incretins; Insulin; Insulin Resistance; Male; Middle Aged; Obesity; Obesity, Morbid; Postoperative Complications | 2007 |
No differences in satiety or energy intake after high-fructose corn syrup, sucrose, or milk preloads.
It is unclear whether energy-containing drinks, especially those sweetened with high-fructose corn syrup (HFCS), promote positive energy balance and thereby play a role in the development of obesity.. The objective was to examine the satiating effects of HFCS and sucrose in comparison with milk and a diet drink.. The effects of four 800-mL drinks [corrected] containing no energy or 1.5 MJ from sucrose, HFCS, or milk on satiety were assessed, first in 15 men and 15 women with a mean (+/-SD) body mass index (BMI; in kg/m(2)) of 22.1 +/- 1.9 according to visual analogue scales (VAS) and blood variables and second in 20 men and 20 women (BMI: 22.4 +/- 2.1) according to ingestion of a standardized ad libitum meal (granola cereal + yogurt, 10.1 kJ/g).. Fifty minutes after consumption of the 1.5-MJ preload drinks containing sucrose, HFCS, or milk, 170%-mm VAS changes in satiety were observed. Glucagon-like peptide 1 (GLP-1) (P < 0.001) and ghrelin (P < 0.05) concentrations changed accordingly. Compensatory energy intake did not differ significantly between the 3 preloads and ranged from 30% to 45%. Energy intake compensations were related to satiety (r = 0.35, P < 0.05). No differences were observed between the effects of the sucrose- and HFCS-containing drinks on changes in VAS and on insulin, glucose, GLP-1, and ghrelin concentrations. Changes in appetite VAS ratings were a function of changes in GLP-1, ghrelin, insulin, and glucose concentrations.. Energy balance consequences of HFCS-sweetened soft drinks are not different from those of other isoenergetic drinks, eg, a sucrose-drink or milk. Topics: Adult; Animals; Blood Glucose; Body Mass Index; Cattle; Energy Intake; Female; Fructose; Ghrelin; Glucagon-Like Peptide 1; Humans; Insulin; Male; Milk; Obesity; Satiety Response; Sucrose; Taste | 2007 |
Influence of BMI and gender on postprandial hormone responses.
Influences of gender and body weight on the hormonal response to eating are not well understood. This study was conducted to determine a convenient time-point to evaluate peak postprandial hormone responses and to test the hypothesis that gender and BMI interact to produce differences in postprandial secretion of selected humoral markers implicated in hunger and satiety.. Fasting blood glucose, insulin, leptin, ghrelin, glucagon-like peptide-1, and glucagon were measured in normal-weight (20 Topics: Adult; Analysis of Variance; Blood Glucose; Body Composition; Body Mass Index; Female; Ghrelin; Glucagon; Glucagon-Like Peptide 1; Humans; Insulin; Leptin; Male; Middle Aged; Obesity; Postprandial Period; Sex Characteristics | 2007 |
From insulin to incretins: a report from the 67th scientific sessions of the American Diabetes Association.
Topics: Biguanides; Diabetes Complications; Diabetes Mellitus; Diet; Dietary Supplements; Dipeptidyl-Peptidase IV Inhibitors; Dyslipidemias; Glucagon-Like Peptide 1; Glycoside Hydrolase Inhibitors; Humans; Hypoglycemic Agents; Insulin; Obesity; Thiazolidinediones | 2007 |
Gut hormone profiles following bariatric surgery favor an anorectic state, facilitate weight loss, and improve metabolic parameters.
To study the effect of bariatric surgery on the entero-hypothalamic endocrine axis of humans and rodents.. Bariatric surgery is the most effective obesity treatment as it achieves substantial and sustained weight loss. Glycemic control and enhanced satiation improve before substantial weight loss occurs. Gut peptides, acting both peripherally and centrally, contribute to glycemic control and regulate food intake.. We examined meal-stimulated responses of insulin, ghrelin, peptide YY (PYY), glucagon-like-peptide-1 (GLP-1), and pancreatic polypeptide (PP) in humans and rodents following different bariatric surgical techniques.. Compared with lean and obese controls, patients following Roux-en-Y gastric bypass (RYGB) had increased postprandial plasma PYY and GLP-1 favoring enhanced satiety. Furthermore, RYGB patients had early and exaggerated insulin responses, potentially mediating improved glycemic control. None of these effects were observed in patients losing equivalent weight through gastric banding. Leptin, ghrelin, and PP were similar in both the surgical groups. Using a rodent model of jejuno-intestinal bypass (JIB), we showed elevated PYY and GLP-1 in JIB rats compared with sham-operated rats. Moreover, exogenous PYY reduced food intake and blockade of endogenous PYY increased food intake. Thus, higher plasma PYY following JIB may contribute to reduced food intake and contribute to weight loss.. Following RYGB and JIB, a pleiotropic endocrine response may contribute to the improved glycemic control, appetite reduction, and long-term changes in body weight. Topics: Adult; Animals; Appetite; Bariatric Surgery; Cross-Sectional Studies; Female; Gastrointestinal Hormones; Ghrelin; Glucagon-Like Peptide 1; Humans; Insulin; Male; Models, Animal; Obesity; Pancreatic Polypeptide; Peptide Hormones; Peptide YY; Rats; Rats, Wistar; Weight Loss | 2006 |
Nutrient-stimulated glucagon-like peptide 1 release after body-weight loss and weight maintenance in human subjects.
Glucagon-like peptide 1 (GLP-1) is a peptide hormone that is released in response to nutrient ingestion. Postprandial GLP-1 release has been reported to be attenuated in obese subjects, but reports on the effect of weight loss on GLP-1 are conflicting. The aim of the present study was to clarify the effect of a weight-loss period and a consecutive weight-maintenance period on nutrient-stimulated GLP-1 release in obese subjects. Nutrient-stimulated (standard breakfast; 1.9 MJ) GLP-1 release was investigated in thirty-two obese subjects on three occasions: before weight loss (T1) (BMI 30.0 (sd 2.5) kg/m(2)); after a 6-week very-low-energy diet (VLED) (T2) (BMI 27.6 (sd 2.3) kg/m(2)); after a 3-month weight-maintenance period (T3) (BMI 27.9 (sd 2.3) kg/m(2)). At each occasion, following a fasting blood sample the test meal was fed and blood was drawn every 30 min for 2 h relative to ingestion in order to determine plasma GLP-1, insulin, glucose and NEFA concentrations. Subjects lost 7 (sd 3.4) kg during the VLED (P<0.0001) and regained 1 (sd 3.2) kg during the weight-maintenance period (NS). The area under the curve for nutrient-stimulated plasma GLP-1 (pmol/l x h) was significantly decreased (P=0.01) at T2 (6.8 (sd 1)) compared with T1 (12.8 (sd 2.9)) and T3 (11.1 (sd 1.5)). Since we found a rebound of concentrations after a weight-maintenance period, decrease after weight loss seems to be transient and possibly due to a negative energy balance. Topics: Adipose Tissue; Adult; Appetite; Blood Glucose; Body Composition; Body Mass Index; Body Weight; Diet; Energy Intake; Energy Metabolism; Fatty Acids, Nonesterified; Female; Glucagon-Like Peptide 1; Humans; Insulin; Insulin Resistance; Male; Middle Aged; Obesity; Weight Loss | 2006 |
Gut and adipocyte peptides.
Topics: Animals; Blood Glucose; Diabetes Mellitus; Glucagon-Like Peptide 1; Humans; Obesity; Peptide Hormones | 2006 |
Effect of GLP-1 on D-glucose transport, lipolysis and lipogenesis in adipocytes of obese subjects.
GLP-1 has anorectic properties and regulates fuel homeostasis through both its insulinotropic and insulinotrophic actions and effects in extrapancreatic tissue. This study is aimed at characterizing the response to GLP-1 of adipocytes from obese patients, in terms of D-glucose transport and lipid metabolism, in comparison with data from normal subjects. Adipocytes were obtained by enzymatic digestion from the abdominal fat tissue of 25 morbidly obese patients and 8 normal subjects undergoing bariatric or inguinal hernia surgery, respectively. Basal GLUT4 expression, D-glucose transport, glycerol release and lipogenesis were measured in cells treated, when required, with 10(-12)-10(-9) M GLP-1, insulin, glucagon and the GLP-1 structurally related peptides, exendin-4 and exendin-9. In obese patients, versus normal subjects, a trend towards lower values was found in GLUT4 protein or mRNA, although the differences were not statistically significant; insulin-stimulated glucose uptake was higher and cells did not respond to GLP-1, while both exendins (10(-10) and 10(-9) M) exerted an inhibitory action; basal lipolysis was higher and so was the effect of GLP-1 and glucagon, whereas insulin abolished the lipolytic action of all peptides; both basal lipogenesis and the response to insulin were higher while GLP-1 and exendin-4 were ineffective. These results document the analogies and dissimilarities between the response to GLP-1, exendin-4 and exendin-9, as well as to insulin and glucagon, relative to glucose transport and lipid metabolism of fat tissue from obese patients versus normal subjects, the reduced lipogenic effect and enhanced lipolytic action of GLP-1 being, perhaps, adequate for its therapeutic use in obesity. Topics: Adipocytes; Down-Regulation; Glucagon-Like Peptide 1; Glucose; Glucose Transporter Type 4; Humans; Lipogenesis; Lipolysis; Obesity; RNA, Messenger | 2006 |
Higher fasting plasma concentrations of glucagon-like peptide 1 are associated with higher resting energy expenditure and fat oxidation rates in humans.
Glucagon-like peptide 1 (GLP-1) is a gut hormone that decreases appetite and promotes satiety. Its role in energy metabolism regulation is still poorly understood.. The aim of the study was to investigate the relation of fasting plasma GLP-1 concentrations to rates of energy expenditure (EE) and substrate oxidation-ie, respiratory quotient (RQ).. Forty-six glucose-tolerant white subjects (22 men, 24 women) aged 18-49 y whose adiposity spanned a wide range [body mass index (in kg/m2): 18.5-50] were studied in an inpatient clinic. Main outcome measures included resting EE and RQ (ventilated hood technique), body composition (dual-energy X-ray absorptiometry), and fasting plasma concentrations of GLP-1, pancreatic polypeptide, glucose, and insulin.. Fasting plasma GLP-1 concentrations were positively associated with resting EE (after adjustment for age, sex, and body composition) and negatively correlated with RQ (after adjustment for age, sex, and percentage body fat) and fasting plasma pancreatic polypeptide concentrations (both before and after adjustment for age, sex, percentage body fat, and fasting plasma glucose and insulin concentrations). Adjustment for fasting plasma pancreatic polypeptide concentrations, a marker of parasympathetic outflow to the gut, attenuated the strength of the association of fasting plasma GLP-1 concentrations with resting EE and RQ.. Higher fasting plasma GLP-1 concentrations are associated with higher rates of EE and fat oxidation independent of age, sex, and body composition. The autonomic nervous system may have a role in this relation. This effect, along with the established role of GLP-1 in promoting satiety, may further foster its therapeutic potential in the treatment of obesity. Topics: Absorptiometry, Photon; Adolescent; Adult; Basal Metabolism; Blood Glucose; Body Composition; Dietary Fats; Energy Metabolism; Fasting; Female; Glucagon-Like Peptide 1; Glucose Tolerance Test; Humans; Insulin; Male; Middle Aged; Obesity; Oxidation-Reduction; Oxygen Consumption; Pancreatic Polypeptide | 2006 |
Effect of a high-fat meal on the postprandial ghrelin response.
Topics: Cholecystokinin; Dietary Fats; Ghrelin; Glucagon-Like Peptide 1; Humans; Obesity; Peptide Hormones; Postprandial Period | 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 |
Oxyntomodulin : a novel potential treatment for obesity.
The prevalence of obesity is increasing rapidly and the associated morbidity and mortality has led to an urgent need for potential therapeutic targets to reduce appetite and food intake. Gut hormones released after eating that coordinate digestive activity and promote satiety are novel potential treatments for obesity. Oxyntomodulin is a gut hormone that is produced by the L cells in the small intestine and reduces food intake. It is timely to review some of the original literature on oxyntomodulin, to evaluate what is already known about the peptide, and also to set the recent findings on its effects on food intake and bodyweight into context.Recent studies have shown that long-term peripheral administration of oxyntomodulin to rats leads to reduced food intake and reduced weight gain. Studies in humans have demonstrated that acute administration reduces food intake by 19%. When given preprandially by subcutaneous injection three times daily, oxyntomodulin resulted in a reduction in food intake and mean weight loss of 2.8kg over 4 weeks. Oxyntomodulin thus represents a potential therapy for obesity.The mechanism of action of oxyntomodulin is not known. Current evidence suggests that it acts via the glucagon-like peptide 1 (GLP-1) receptor. There may be an additional receptor in the gastric mucosa mediating its effects on gastric acid secretion. Although oxyntomodulin probably acts via the GLP-1 receptor, the two peptides differentially regulate food intake and energy expenditure in the mouse.Oxyntomodulin represents a potential therapy for obesity. Further work will help to clarify its mechanisms of action. Topics: Animals; Eating; Gastrointestinal Hormones; Glucagon-Like Peptide 1; Glucagon-Like Peptide 2; Humans; Obesity; Oxyntomodulin | 2006 |
Effects of resistant starch, a non-digestible fermentable fiber, on reducing body fat.
To assess the effects of energy dilution with non-fermentable and fermentable fibers on abdominal fat and gut peptide YY (PYY) and glucagon-like peptide (GLP)-1 expressions, three rat studies were conducted to: determine the effects of energy dilution with a non-fermentable fiber, compare similar fiber levels of fermentable and non-fermentable fibers, and compare similar metabolizable energy dilutions with fermentable and non-fermentable fibers.. In Study 1, rats were fed one of three diets with different metabolizable energy densities. In Study 2, rats were fed diets with similar fiber levels using high amylose-resistant cornstarch (RS) or methylcellulose. In Study 3, rats were fed diets with a similar dilution of metabolizable energy using cellulose or RS. Measurements included food intake, body weight, abdominal fat, plasma PYY and GLP-1, gastrointestinal tract weights, and gene transcription of PYY and proglucagon.. Energy dilution resulted in decreased abdominal fat in all studies. In Study 2, rats fed fermentable RS had increased cecal weights and plasma PYY and GLP-1, and increased gene transcription of PYY and proglucagon. In Study 3, RS-fed rats had increased short-chain fatty acids in cecal contents, plasma PYY (GLP-1 not measured), and gene transcription for PYY and proglucagon.. Inclusion of RS in the diet may affect energy balance through its effect as a fiber or a stimulator of PYY and GLP-1 expression. Increasing gut hormone signaling with a bioactive functional food such as RS may be an effective natural approach to the treatment of obesity. Topics: Adipose Tissue; Animals; Cecum; Dietary Fiber; Energy Intake; Energy Metabolism; Fatty Acids, Volatile; Female; Fermentation; Glucagon-Like Peptide 1; Humans; Obesity; Organ Size; Peptide YY; Proglucagon; Random Allocation; Rats; Rats, Sprague-Dawley; Starch | 2006 |
Effects of sub-chronic exposure to naturally occurring N-terminally truncated metabolites of glucose-dependent insulinotrophic polypeptide (GIP) and glucagon-like peptide-1 (GLP-1), GIP(3-42) and GLP-1(9-36)amide, on insulin secretion and glucose homeosta
Glucose-dependent insulinotrophic polypeptide (GIP) and glucagon-like peptide-1 (GLP-1) are important enteroendocrine hormones that are rapidly degraded by an ubiquitous enzyme dipeptidyl peptidase IV to yield truncated metabolites GIP(3-42) and GLP-1(9-36)amide. In this study, we investigated the effects of sub-chronic exposure to these major circulating forms of GIP and GLP-1 on blood glucose control and endocrine pancreatic function in obese diabetic (ob/ob) mice. A once daily injection of either peptide for 14 days had no effect on body weight, food intake or pancreatic insulin content or islet morphology. GLP-1(9-36)amide also had no effect on plasma glucose homeostasis or insulin secretion. Mice receiving GIP(3-42) exhibited small but significant improvements in non-fasting plasma glucose, glucose tolerance and glycaemic response to feeding. Accordingly, plasma insulin responses were unchanged suggesting that the observed enhancement of insulin sensitivity was responsible for the improvement in glycaemic control. These data indicate that sub-chronic exposure to GIP and GLP-1 metabolites does not result in physiological impairment of insulin secretion or blood glucose control. GIP(3-42) might exert an overall beneficial effect by improving insulin sensitivity through extrapancreatic action. Topics: Animals; Blood Glucose; Diabetes Mellitus; Eating; Gastric Inhibitory Polypeptide; Glucagon-Like Peptide 1; Glucose Tolerance Test; Homeostasis; Immunohistochemistry; Insulin; Insulin Resistance; Insulin Secretion; Insulin-Secreting Cells; Islets of Langerhans; Mice; Mice, Obese; Obesity; Organ Size; Peptide Fragments; Peptides; Receptors, Gastrointestinal Hormone | 2006 |
Gastric sensorimotor functions and hormone profile in normal weight, overweight, and obese people.
Peptide YY (PYY) levels are reported to be decreased in obesity. The relation between gastric functions, satiation, and gut hormones in obesity is incompletely understood. The aim of this study was to compare gastric volumes, emptying, maximum tolerated volumes, postchallenge symptoms, and selected gut hormones in normal, overweight, or obese healthy volunteers.. In 73 nonbulimic normal, overweight, or obese participants weighing less than 137 kg, we measured gastric emptying of solids and liquids by scintigraphy (gastric emptying half-time [GE t(1/2)]); gastric volumes by single-photon emission computed tomography; maximum tolerated volumes and symptoms by satiation test; and plasma leptin, ghrelin, insulin, glucagon-like peptide 1, and PYY levels. Groups were compared using 1-way analysis of covariance adjusted for sex. Univariate associations among measured responses were assessed using Spearman correlations. Multiple linear regression models, adjusting for weight and sex, assessed the independent ability of gastric functions and hormones to predict satiation volume.. Obese and overweight subjects had significantly lower postprandial gastric volumes, higher fasting and postprandial insulin and leptin levels, and lower fasting ghrelin and lower postprandial reduction in ghrelin levels. PYY levels were not different in obese or overweight subjects compared with controls. The GE t(1/2) was correlated inversely with postprandial PYY; increased body weight was associated with faster GE t(1/2) of solids (r(s) = 0.33, P = .005) and liquids (r(s) = 0.24, P = .04). Postprandial changes in gastric volume and PYY were independent predictors of satiation (both P = .01).. Overweight or obesity are associated with lower postprandial gastric volumes and normal PYY levels. Gastric emptying influences postprandial PYY levels. Postprandial PYY and gastric volume independently predict satiation volume in nonbulimic people across a wide body mass index range. Topics: Adolescent; Adult; Aged; Female; Gastric Emptying; Gastrointestinal Hormones; Ghrelin; Glucagon-Like Peptide 1; Humans; Insulin; Leptin; Male; Middle Aged; Motor Neurons; Neurons, Afferent; Obesity; Overweight; Peptide Hormones; Peptide YY; Regression Analysis; Satiation; Stomach | 2006 |
Exenatide (exendin-4) improves insulin sensitivity and {beta}-cell mass in insulin-resistant obese fa/fa Zucker rats independent of glycemia and body weight.
The effects of the incretin mimetic exenatide (exendin-4) on metabolic parameters, insulin sensitivity, and beta-cell mass were examined in nondiabetic, insulin-resistant obese fa/fa Zucker rats. After 6 wk of treatment, ad libitum-fed exenatide-treated (EX) and pair-fed vehicle control (PF) rats had comparable food intake, body weight, hemoglobin A(1c) (HbA(1c)), and fasting plasma concentrations of glucose, insulin, and lipids. Concurrent decreases in food intake and weight gain were observed in EX and PF rats, compared with ad libitum-fed vehicle control (CON) rats (P < 0.001). The increases in HbA(1c) and fasting plasma insulin concentrations that occur during the normal progression of this disease model were significantly reduced in EX and PF rats, compared with CON rats (P < 0.001). The insulin sensitivity index (ISI; glucose infusion rate to plasma insulin concentration) measured during a hyperinsulinemic euglycemic clamp was 224% higher in EX rats than CON rats (P < 0.001) and 61% higher in EX rats than PF rats (P < 0.004). The latter difference was despite comparable HbA(1c), fasting glucose, fasting insulin, total cholesterol, high-density lipoprotein, and daily food consumption between EX and PF animals. In the absence of exenatide, beta-cell mass was hyperbolically related to ISI (beta-cell mass * ISI was constant). Analogous to the disposition index, the beta-cell mass * ISI product was 63% greater in EX than PF rats (P < 0.05). Thus, exenatide increased beta-cell mass to a greater extent than would be expected in animals of comparable insulin resistance, suggesting a direct trophic effect on islet neogenesis in obese fa/fa rats independent of body weight and glycemia. Topics: Animals; Blood Glucose; Body Weight; Exenatide; Glucagon; Glucagon-Like Peptide 1; Glycated Hemoglobin; Insulin; Islets of Langerhans; Male; Obesity; Peptide Fragments; Peptides; Protein Precursors; Rats; Rats, Zucker; Venoms | 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 |
Oligofructose promotes satiety in rats fed a high-fat diet: involvement of glucagon-like Peptide-1.
To analyze the putative interest of oligofructose (OFS) in the modulation of food intake after high-fat diet in rats and to question the relevance of the expression and secretion of intestinal peptides in that context.. Male Wistar rats were pretreated with standard diet or OFS-enriched (10%) standard diet for 35 days followed by 15 days of high-fat diet enriched or not with OFS (10%) treatment. Body weight, food intake, triglycerides, and plasma ghrelin levels were monitored during the treatment. On day 50, rats were food-deprived 8 hours and anesthetized for blood and intestinal tissue sampling for further proglucagon mRNA, glucagon-like peptide (GLP)-1, and GLP-2 quantification.. The addition of OFS in the diet protects against the promotion of energy intake, body weight gain, fat mass development, and serum triglyceride accumulation induced by a high-fat diet. OFS fermentation leads to an increase in proglucagon mRNA in the cecum and the colon and in GLP-1 and GLP-2 contents in the proximal colon, with consequences on the portal concentration of GLP-1 (increase). A lower ghrelin level is observed only when OFS is added to the standard diet of rats.. In rats exposed to high-fat diet, OFS is, thus, able to modulate endogenous production of gut peptides involved in appetite and body weight regulation. Because several approaches are currently used to treat type 2 diabetes and obesity with limited effectiveness, dietary fibers such as OFS, which promote the endogenous production of gut peptides like GLP-1, could be proposed as interesting nutrients to consider in the management of fat intake and associated metabolic disorders. Topics: Animals; Body Weight; Dietary Fats; Dipeptidyl Peptidase 4; Eating; Ghrelin; Glucagon; Glucagon-Like Peptide 1; Glucagon-Like Peptide 2; Intestinal Mucosa; Liver; Male; Obesity; Oligosaccharides; Peptide Fragments; Peptide Hormones; Peptides; Proglucagon; Protein Precursors; Rats; Rats, Wistar; Reverse Transcriptase Polymerase Chain Reaction; RNA, Messenger; Triglycerides | 2005 |
Gastric bypass and nesidioblastosis--too much of a good thing for islets?
Topics: Adenosine Deaminase Inhibitors; Dipeptidyl Peptidase 4; Gastric Bypass; Glucagon; Glucagon-Like Peptide 1; Glycoproteins; Humans; Hyperinsulinism; Hyperplasia; Hypoglycemia; Islets of Langerhans; Nesidioblastosis; Obesity; Peptide Fragments; Postoperative Complications; Protein Precursors; Signal Transduction | 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 |
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 |
S 23521 decreases food intake and body weight gain in diet-induced obese rats.
To investigate the effect of S 23521, a new glucagon-like peptide-1-(7-36) amide analogue, on food intake and body weight gain in obese rats, as well as on gene expression of several proteins involved in energy homeostasis.. Lean and diet-induced obese rats were treated with either S 23521 or vehicle. S 23521 was given either intraperitoneally (10 or 100 microg/kg) or subcutaneously (100 microg/kg) for 14 and 20 days, respectively. Because the low-dose treatment did not affect food intake and body weight, the subcutaneous treatment at high dose was selected to test the effect on selected end-points.. Treated obese rats significantly decreased their cumulative energy intake in relation to vehicle-treated counterparts (3401 +/- 65 vs. 3898 +/- 72 kcal/kg per 20 days; p < 0.05). Moreover, their body weight gain was reduced by 110%, adiposity was reduced by 20%, and plasma triglyceride levels were reduced by 38%. The treatment also improved glucose tolerance and insulin sensitivity of obese rats. Regarding gene expression, no changes in uncoupling protein-1, uncoupling protein-3, leptin, resistin, and peroxisome proliferator-activated receptor (PPAR)-gamma were observed.. S 23521 is an effective glucagon-like peptide-1-(7-36) amide analogue, which induced a decrease in energy intake, body weight, and adiposity in a rat model of diet-induced obesity. In addition, the treatment also improved glucose tolerance and insulin sensitivity of obese rats. These results strongly support S 23521 as a putative molecule for the treatment of obesity. Topics: Adipose Tissue; Animals; Anti-Obesity Agents; Dose-Response Relationship, Drug; Eating; Energy Metabolism; Glucagon; Glucagon-Like Peptide 1; Glucagon-Like Peptides; Injections, Intraperitoneal; Injections, Subcutaneous; Male; Obesity; Peptide Fragments; Random Allocation; Rats; Rats, Wistar; Time Factors; Weight Gain | 2004 |
Activity-induced GLP-1 release in lean and obese subjects.
The aim of the study was to determine whether physical activity stimulates GLP-1 release on the short-term in normal weight and in obese subjects compared to rest and, furthermore, whether modest weight loss affects GLP-1 release or sensitivity in the obese. Normal weight (n=28; 12 males, 16 females; BMI 22.9+/-1.4; age 35+/-12.7), as well as obese subjects (n=27; 21 males, 6 females; BMI 30.9+/-2.7; age 47.1+/-11.86) were tested in a resting and a physical activity condition. Obese subjects were matched over two groups for a weight loss period of 3 months. After weight loss, the tests were repeated. The area under the curve (AUC pmol/lxmin) for GLP-1 concentrations was significantly increased in the physical activity condition compared to rest in lean subjects (P=0.05) as well as in the obese subjects after weight loss (P<0.05), but not in the obese subjects before weight loss. Physical activity-stimulated GLP-1 release in lean and obese subjects after a weight loss period supports the idea of a neuroendocrine loop in addition to distal-intestinal stimulation of GLP-1 release. Modest weight loss might be effective for increasing GLP-1 sensitivity to acute stimulation. Topics: Adult; Analysis of Variance; Area Under Curve; Basal Metabolism; Blood Glucose; Enzyme-Linked Immunosorbent Assay; Female; Glucagon; Glucagon-Like Peptide 1; Humans; Male; Middle Aged; Motor Activity; Obesity; Peptide Fragments; Protein Precursors; Thinness; Weight Loss | 2004 |
Cholecystokinin, glucose dependent insulinotropic peptide and glucagon-like peptide 1 secretion in children with anorexia nervosa and simple obesity.
Cholecystokinin (CCK), glucose dependent insulinotropic peptide (GIP), and glucagon-like peptide 1 (GLP-1) regulate satiety as enterogastrons and incretins. They also directly affect the satiety centers. Therefore, these peptides may participate in the pathogenesis of eating disorders. CCK, GIP, and GLP-1 secretion were studied in 13 adolescent girls suffering from simple obesity, 13 girls with anorexia nervosa, and 10 healthy girls. Each girl was subjected to an oral glucose tolerance test (OGTT) and standard meal test. Blood was collected before stimulation and at 15, 30, 60, and 120 min. The concentrations of all peptides were determined by RIA commercial kits. Fasting and postprandial levels of these peptides as well as integrated outputs were measured. High postprandial levels of CCK observed in the girls with anorexia may aggravate the course of this disease by intensifying nausea and vomiting. Low postprandial level of GLP-1 in girls with simple obesity may be responsible for excessive ingestion of food and weaker inhibition of gastric emptying, which also leads to obesity. Topics: Adolescent; Anorexia Nervosa; Child; Cholecystokinin; Female; Gastric Inhibitory Polypeptide; Glucagon; Glucagon-Like Peptide 1; Humans; Male; Obesity; Peptide Fragments; Protein Precursors; Radioimmunoassay | 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 |
Comparisons of leptin, incretins and body composition in obese and lean patients with hypopituitarism and healthy individuals.
To identify possible abnormalities specific for obesity in hypopituitary patients.. Cross-sectional case-control study. MEASUREMENTS AND STUDY SUBJECTS: Body composition (DEXA) and measurements of fasting plasma levels of glucose-dependent insulinotropic polypeptide (GIP), glucagon-like peptides (GLPs), insulin, C-peptide, glucose, leptin and lipids were performed in 25 hypopituitary patients (15 obese, 10 normal weight) and 26 BMI and age-matched healthy controls (16 obese, 10 normal weight). All hypopituitary patients had GH deficiency and received adequate substitution therapy on this and other deficient axes (3 +/- 1).. Fasting GIP-levels were significantly higher in obese hypopituitary patients compared to lean hypopituitary patients (P < 0.01), while the fasting concentrations of GLP-1 and GLP-2 were comparable between obese and lean hypopituitary patients. The same trend was seen in obese healthy controls vs. lean controls. No differences were observed in glucose, insulin or C-peptide between the hypopituitary patients and the controls. Leptin levels were increased in obese hypopituitary patients compared to lean hypopituitary patients when adjusted for gender. At least a 2-fold higher level of leptin was observed in women compared to men in both patient groups and healthy controls. Lean female hypopituitary patients had higher leptin levels than matched controls.. Fasting levels of GIP were elevated in obese substituted hypopituitary patients, while fasting concentrations of GLPs were similar. Obese hypopituitary patients had the same degree of hyperinsulinaemia, affected glucose tolerance, dyslipoproteinaemia and central obesity as obese healthy controls. Further studies are required to identify the possible biochemical reasons for obesity in patients with apparently well-substituted hypopituitarism. Topics: Adult; Anthropometry; Body Composition; Case-Control Studies; Cross-Sectional Studies; Fasting; Female; Gastric Inhibitory Polypeptide; Glucagon; Glucagon-Like Peptide 1; Glucagon-Like Peptide 2; Glucagon-Like Peptides; Human Growth Hormone; Humans; Hypopituitarism; Leptin; Lipids; Male; Middle Aged; Obesity; Peptide Fragments; Peptides; Thinness | 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 |
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 |
Effects of the novel (Pro3)GIP antagonist and exendin(9-39)amide on GIP- and GLP-1-induced cyclic AMP generation, insulin secretion and postprandial insulin release in obese diabetic (ob/ob) mice: evidence that GIP is the major physiological incretin.
This study examined the biological effects of the GIP receptor antagonist, (Pro3)GIP and the GLP-1 receptor antagonist, exendin(9-39)amide.. Cyclic AMP production was assessed in Chinese hamster lung fibroblasts transfected with human GIP or GLP-1 receptors, respectively. In vitro insulin release studies were assessed in BRIN-BD11 cells while in vivo insulinotropic and glycaemic responses were measured in obese diabetic ( ob/ ob) mice.. In GIP receptor-transfected fibroblasts, (Pro(3))GIP or exendin(9-39)amide inhibited GIP-stimulated cyclic AMP production with maximal inhibition of 70.0+/-3.5% and 73.5+/-3.2% at 10(-6) mol/l, respectively. In GLP-1 receptor-transfected fibroblasts, exendin(9-39)amide inhibited GLP-1-stimulated cyclic AMP production with maximal inhibition of 60+/-0.7% at 10(-6) mol/l, whereas (Pro(3))GIP had no effect. (Pro(3))GIP specifically inhibited GIP-stimulated insulin release (86%; p<0.001) from clonal BRIN-BD11 cells, but had no effect on GLP-1-stimulated insulin release. In contrast, exendin(9-39)amide inhibited both GIP and GLP-1-stimulated insulin release (57% and 44%, respectively; p<0.001). Administration of (Pro(3))GIP, exendin(9-39)amide or a combination of both peptides (25 nmol/kg body weight, i.p.) to fasted (ob/ob) mice decreased the plasma insulin responses by 42%, 54% and 49%, respectively (p<0.01 to p<0.001). The hyperinsulinaemia of non-fasted (ob/ob) mice was decreased by 19%, 27% and 18% (p<0.05 to p<0.01) by injection of (Pro3)GIP, exendin(9-39)amide or combined peptides but accompanying changes of plasma glucose were small.. These data show that (Pro(3))GIP is a specific GIP receptor antagonist. Furthermore, feeding studies in one commonly used animal model of obesity and diabetes, (ob/ob) mice, suggest that GIP is the major physiological component of the enteroinsular axis, contributing approximately 80% to incretin-induced insulin release. Topics: Animals; Cells, Cultured; Cricetinae; Cricetulus; Cyclic AMP; Diabetes Mellitus; Gastric Inhibitory Polypeptide; Glucagon; Glucagon-Like Peptide 1; Glucagon-Like Peptides; Humans; Hyperinsulinism; Insulin; Insulin Secretion; Mice; Obesity; Peptide Fragments; Postprandial Period; Protein Precursors; Spectrometry, Mass, Electrospray Ionization | 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 |
Racial differences in glucagon-like peptide-1 (GLP-1) concentrations and insulin dynamics during oral glucose tolerance test in obese subjects.
Obese African-American (AA) subjects have higher resting and stimulated insulin concentrations than obese Caucasians (C), which could not be explained by the severity of obesity or the degree of insulin sensitivity. We investigated whether differences in glucagon-like peptide-1 (GLP-1), the most potent incretin that regulates insulin secretion, might explain racial differences in insulin response. Accordingly, we measured fasting and stimulated glucose, insulin, and GLP-1 levels during a 3-h oral glucose tolerance test (OGTT) in 26 obese C (age 38+/-2 y, body mass index 44+/-1 kg/m(2)) and 16 obese AA (age 36+/-2 y, BMI 46+/-2 kg/m(2)) subjects. Corrected insulin response (CIR(30)), a measure of beta-cell activity, whole body insulin sensitivity index (WBISI), and area under the curve (AUC) for insulin, GLP-1, and C-peptide/insulin ratio were computed from the OGTT. Glucose levels, fasting and during the OGTT, were similar between racial groups; 32% of the C and 31% of the AA subjects had impaired glucose tolerance. With a similar WBISI, AAs had significantly higher CIR(30) (2.3+/-0.4 vs 1.01+/-0.1), insulin response (IAUC: 23 974+/-4828 vs 14 478+/-1463), and lower insulin clearance (0.07+/-0.01 vs 0.11+/-0.01) than C (all, P<0.01). Obese AAs also had higher fasting GLP-1 (6.7+/-2.5 vs 4.5+/-1.1) and GLP-1AUC (1174.7+/-412 vs 822.4+/-191) than C (both, P<0.02). Our results indicate that obese AAs had higher concentrations of GLP-1 both at fasting and during the OGTT than obese C. The increased GLP-1 concentration could explain the greater insulin concentration and the increased prevalence of hyperinsulinemia-associated disorders including obesity and type 2 diabetes in AAs. Topics: Adult; Anthropometry; Black or African American; Body Composition; Body Mass Index; Energy Intake; Fasting; Female; Glucagon; Glucagon-Like Peptide 1; Glucose Tolerance Test; Humans; Insulin; Male; Obesity; Peptide Fragments; Protein Precursors | 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 |
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 |
Elevated glucagon-like peptide-1-(7-36)-amide, but not glucose, associated with hyperinsulinemic compensation for fat feeding.
We previously developed a canine model of central obesity and insulin resistance by supplementing the normal chow diet with 2 g cooked bacon grease/kg body weight. Dogs fed this fatty diet maintained glucose tolerance with compensatory hyperinsulinemia. The signal(s) responsible for this up-regulation of plasma insulin is unknown. We hypothesized that meal-derived factors such as glucose, fatty acids, or incretin hormones may signal beta-cell compensation in the fat-fed dog. We fed the same fat-supplemented diet for 12 wk to six dogs and compared metabolic responses with seven control dogs fed a normal diet. Fasting and stimulated fatty acid and glucose-dependent insulinotropic peptide concentrations were not increased by fat feeding, whereas glucose was paradoxically decreased, ruling out those three factors as signals for compensatory hyperinsulinemia. Fasting plasma glucagon-like peptide-1 (GLP-1) concentration was 2.5-fold higher in the fat-fed animals, compared with controls, and 3.4-fold higher after a mixed meal. Additionally, expression of the GLP-1 receptor in whole pancreas was increased 2.3-fold in the fat-fed dogs. The increase in both circulating GLP-1 and its target receptor may have increased beta-cell responsiveness to lower glucose. Glucose is not the primary cause of hyperinsulinemia in the fat-fed dog. Corequisite meal-related signals may be permissive for development of hyperinsulinemia. Topics: Animals; Blood Glucose; Blotting, Northern; Dietary Fats; Dogs; Fasting; Fatty Acids, Nonesterified; Gene Expression; Glucagon; Glucagon-Like Peptide 1; Glucagon-Like Peptide-1 Receptor; Glucagon-Like Peptides; Glucose; Glucose Tolerance Test; Hyperinsulinism; Insulin; Insulin Resistance; Islets of Langerhans; Kinetics; Magnetic Resonance Imaging; Male; Obesity; Peptide Fragments; Receptors, Glucagon; Reverse Transcriptase Polymerase Chain Reaction | 2002 |
GLP-1 as a satiety factor in children with eating disorders.
GLP-1, with its insulinotropic properties and direct action on satiety center in the brain, may be the main hormone regulating the amount of ingested food. In this study, GLP-1 secretion was investigated in age-matched adolescent girls (14 +/- 2 years): 13 with anorexia nervosa (BMI 14.8 +/- 1.4 kg/m(2)), 13 with simple obesity (BMI 33.0 +/- 3.3 kg/m(2)) and 10 healthy girls as a control group (BMI 21.6 +/- 0.7 kg/m(2)). Each girl was subjected to OGTT and standard meal tests after a 12 h overnight fast. Blood samples were collected before and 15, 30, 60, and 120 min after the stimulation. The mean fasted GLP-1 levels in simple obesity group (1.6 +/- 0.3 pmol/l) and in anorexia nervosa group (1.7 +/- 0.3 pmol/l) were significantly lower than those in the control group (2.6 +/- 0.4 pmol/l) (p < 0.05 in both cases). The highest peak concentration of GLP-1 was observed in the control group after both stimuli. In each group, the mean integrated GLP-1 outputs were almost twice as high after OGTT than after the test meal (p < 0.001 in each case). In our opinion, low secretion of GLP-1 in girls with simple obesity may seriously and negatively influence the course of this disease. On the other hand, low GLP-1 levels in girls with anorexia nervosa are beneficial and promote appetite. Topics: Adolescent; Anorexia Nervosa; Blood Glucose; Fasting; Feeding and Eating Disorders; Female; Glucagon; Glucagon-Like Peptide 1; Glucose Tolerance Test; Humans; Insulin; Obesity; Peptide Fragments; Protein Precursors; Satiation | 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 |
Nutrient regulation of post-heparin lipoprotein lipase activity in obese subjects.
This study examines the immediate effect of ingestion of oral carbohydrate and fat on lipoprotein lipase (LPL) activity post-heparin in six lean and six obese age-matched women. Subjects were given, on two separate occasions, 340 kcal carbohydrate or an equicaloric amount of fat, both in 300 ml of water. Post-heparin LPL activity (10,000 U) was measured on each occasion 120 minutes after ingestion of the meal. Following oral carbohydrate postprandial plasma insulin levels were significantly higher in obese subjects than in lean (p < 0.01). Impaired glucose tolerance was seen in the obese group. GIP secretion was similar in lean and obese subjects both during oral fat and carbohydrate ingestion. GLP-1 secretion post-carbohydrate was lower in obese subjects. Total LPL activity unadjusted for body weight was similar in the two groups after carbohydrate administration but was significantly lower when adjusted per kg body weight. Total LPL activity was lower in the lean group at 130 minutes after fat administration (p < 0.02). Fasting serum triglycerides were higher in the obese group and were inversely related to the post-carbohydrate LPL activity (r = - 0.65, p < 0.02). Intraluminal lipoprotein lipase activity is not increased in established obesity. Fat and carbohydrate nutrients may affect LPL activity differently in lean and obese subjects. Topics: Adult; Anticoagulants; Blood Glucose; Dietary Carbohydrates; Dietary Fats; Female; Gastric Inhibitory Polypeptide; Glucagon; Glucagon-Like Peptide 1; Heparin; Humans; Insulin; Lipoprotein Lipase; Obesity; Peptide Fragments; Protein Precursors; Triglycerides | 2001 |
Attenuated processing of proglucagon and glucagon-like peptide-1 in carboxypeptidase E-deficient mice.
The maturation of many peptide hormones is attenuated in carboxypeptidase E (CPE)-deficient fat/fat mice, leading to a slowly developing, adult-onset obesity with mild diabetes. To determine the contribution of the hormones generated from the proglucagon precursor to this phenotype, we studied the tissue-specific processing of glucagon and glucagon-like peptide-1 (GLP-1) in these mice. In all tissues examined there was a great reduction in mature amidated GLP-1. Furthermore, a lack of CPE attenuates prohormone convertase processing of proglucagon in both the pancreas and the intestine. These findings suggest that defects in proglucagon processing together with other endocrine malfunctions could contribute to the diabetic and obesity phenotype in fat/fat mice. Topics: Animals; Carboxypeptidase H; Carboxypeptidases; Chromatography, Gel; Diabetes Mellitus, Experimental; Furin; Glucagon; Glucagon-Like Peptide 1; Intestinal Mucosa; Mice; Mice, Mutant Strains; Obesity; Pancreas; Peptide Fragments; Proglucagon; Protein Precursors; Subtilisins; Tissue Extracts | 2001 |
The role of postprandial releases of insulin and incretin hormones in meal-induced satiety--effect of obesity and weight reduction.
Previous studies have indicated that the secretion of the intestinal satiety hormone glucagon-like peptide-1 (GLP-1) is attenuated in obese subjects.. To compare meal-induced response of GLP-1 and glucose-dependent insulinotropic polypeptide (GIP) in obese and lean male subjects, to investigate the effect of a major weight reduction in the obese subjects, and to look for an association between these hormones and ad libitum food intake.. Plasma concentrations of intestinal hormones and appetite sensations were measured prior to, and every 30 min for 180 min after, ingestion of a 2.5 MJ solid test meal. Gastric emptying was estimated scintigraphically. An ad libitum lunch was served 3 h after the test meal.. Nineteen non-diabetic obese (body mass index (BMI) 34.1--43.8 kg/m(2)) and 12 lean (BMI 20.4--24.7 kg/m(2)) males. All obese subjects were re-examined after a mean stabilised weight loss of 18.8 kg (95% CI 14.4--23.2).. Total area under the GLP-1 response curve (AUC(total, GLP-1)) was lower in obese before and after the weight loss compared to lean subjects (P<0.05), although weight loss improved the response from 80 to 88% of that of the lean subjects (P=0.003). The GIP response was similar in obese and lean subjects. However, after the weight loss both AUC(total, GIP) and AUC(incremental, GIP) were lowered (P<0.05). An inverse correlation was observed between AUC(incremental, GIP) and energy intake at the subsequent ad libitum meal in all groups. In lean subjects ad libitum energy intake was largely predicted by the insulin response to the preceding meal (r(2)=0.67, P=0.001).. Our study confirmed previous findings of a reduced postprandial GLP-1 response in severely obese subjects. Following weight reduction, GLP-1 response in the obese subjects apparently rose to a level between that of obese and lean subjects. The data suggests that postprandial insulin and GIP responses are key players in short-term appetite regulation. Topics: Absorptiometry, Photon; Adult; Appetite; Area Under Curve; Energy Intake; Gastric Emptying; Gastric Inhibitory Polypeptide; Glucagon; Glucagon-Like Peptide 1; Glucagon-Like Peptides; Humans; Insulin; Insulin Resistance; Insulin Secretion; Male; Middle Aged; Obesity; Peptide Fragments; Postprandial Period; Satiation; Weight Loss | 2001 |
Systemic administration of the long-acting GLP-1 derivative NN2211 induces lasting and reversible weight loss in both normal and obese rats.
Postprandial release of the incretin glucagon-like peptide-1 (GLP-1) has been suggested to act as an endogenous satiety factor in humans. In rats, however, the evidence for this is equivocal probably because of very high endogenous activity of the GLP-1 degrading enzyme dipeptidyl peptidase-IV. In the present study, we show that intravenously administered GLP-1 (100 and 500 microg/kg) decreases food intake for 60 min in hungry rats. This effect is pharmacologically specific as it is inhibited by previous administration of 100 microg/kg exendin(9-39), and biologically inactive GLP-1(1-37) had no effect on food intake when administered alone (500 microg/kg). Acute intravenous administration of GLP-1 also caused dose-dependent inhibition of water intake, and this effect was equally well abolished by previous administration of exendin(9-39). A profound increase in diuresis was observed after intravenous administration of both 100 and 500 microg/kg GLP-1. Using a novel long-acting injectable GLP-1 derivative, NN2211, the acute and subchronic anorectic potentials of GLP-1 and derivatives were studied in both normal rats and rats made obese by neonatal monosodium glutamate treatment (MSG). We showed previously that MSG-treated animals are insensitive to the anorectic effects of centrally administered GLP-1(7-37). Both normal and MSG-lesioned rats were randomly assigned to groups to receive NN2211 or vehicle. A single bolus injection of NN2211 caused profound dose-dependent inhibition of overnight food and water intake and increased diuresis in both normal and MSG-treated rats. Subchronic multiple dosing of NN2211 (200 microg/kg) twice daily for 10 days to normal and MSG-treated rats caused profound inhibition of food intake. The marked decrease in food intake was accompanied by reduced body weight in both groups, which at its lowest stabilized at approximately 85% of initial body weight. Initial excursions in water intake and diuresis were transient as they were normalized within a few days of treatment. Lowered plasma levels of triglycerides and leptin were observed during NN2211 treatment in both normal and MSG-treated obese rats. In a subsequent study, a 7-day NN2211 treatment period of normal rats ended with measurement of energy expenditure (EE) and body composition determined by indirect calorimetry and dual energy X-ray absorptiometry, respectively. Compared with vehicle-treated rats, NN2211 and pair-fed rats decreased their total EE corresponding to the Topics: Animals; Blood Glucose; Body Weight; Defecation; Diuresis; Dose-Response Relationship, Drug; Drinking; Drug Administration Schedule; Eating; Energy Metabolism; Feeding Behavior; Glucagon; Glucagon-Like Peptide 1; Lipids; Liraglutide; Male; Obesity; Peptide Fragments; Protein Precursors; Rats; Rats, Wistar; Reference Values; Time Factors | 2001 |
Peripheral versus central effects of glucagon-like peptide-1 receptor agonists on satiety and body weight loss in Zucker obese rats.
The present study explores the potential utility of peripheral versus central administration of glucagon-like peptide-1 (GLP-1) receptor agonists in the regulation of feeding behavior in Wistar and Zucker obese rats. Acute central (intracerebroventricular [i.c.v.]) and peripheral (subcutaneous [s.c.]) administration of both GLP-1 (7-36) amide and exendin-4 resulted in a reduction in food intake for at least 4 hours, exendin-4 being much more potent than GLP-1 (7-36) amide, especially after peripheral administration. Both Zucker obese rats (fa/fa) and their lean littermates (Fa/-) responded to acute central and peripheral administration of exendin-4. Moreover, in situ hybridization revealed specific labeling for the mRNA for GLP-1 receptors in several brain areas of both the obese and lean rats. The presence of this receptor was also detected by affinity cross-linking assays. Long-term s.c. administration of exendin-4 (1 single injection per day, 1 hour prior to the onset of the dark phase of the cycle) decreased daily food intake and practically blocked weight gain in obese rats. In contrast to previous studies, these findings show that peripheral (s.c.) administration of both GLP-1 receptor agonists also induces satiety and weight loss in rats, and suggest the potential usefulness of exendin-4 as a therapeutic tool for the treatment of diabetes and/or obesity. Topics: Amines; Animals; Appetite; Body Weight; Brain; Diabetes Mellitus; Drinking; Eating; Exenatide; Glucagon; Glucagon-Like Peptide 1; Glucagon-Like Peptide-1 Receptor; Glucagon-Like Peptides; In Situ Hybridization; Injections, Intraventricular; Injections, Subcutaneous; Male; Obesity; Peptide Fragments; Peptides; Rats; Rats, Wistar; Rats, Zucker; Receptors, Glucagon; RNA, Messenger; Venoms | 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 |
Oral triacylglycerols regulate plasma glucagon-like peptide-1(7-36) and insulin levels in normal and especially in obese rats.
In a previous study of glucose tolerance, plasma insulin levels were greatly elevated in genetically obese Wistar fatty rats but not lean rats fed a diet containing polyunsaturated fatty acids. In the present study, triacylglycerol-regulation of levels of circulating insulin and glucagon-like peptide-1 (7-36) (GLP-1) has been investigated in these rats. In the glucose tolerance test, the two plasma insulin peaks appeared in obese and lean rats intubated with glucose + corn oil, at 15- 30 min and 4 h, whereas only the first peak appeared in rats intubated with glucose alone, although the glucose response did not differ. After intubation of corn oil only, the insulin peak at 15 min was not detected but the peak at 4h was large. The two plasma GLP-1 peaks appeared 15 min and 4 h after intubation of glucose + corn oil similarly to the insulin responses, although the first peak was small and the second peak was very large. A small peak at 15 min was not significant in rats intubated glucose alone and no peak was seen at 4 h. The GLP-1 concentrations were significantly higher in the following order: portal vein > inferior vena cava > tail vein. The plasma GLP-1 increment in response to oral triacylglycerols was significantly higher in obese rats than in lean rats as was the insulin increment. Thus, oral triacylglycerols (possibly polyunsaturated) appeared to act at the gut lumen to stimulate GLP-1 secretion, which may be responsible for the second (4 h) insulin peak. Topics: Administration, Oral; Animals; Blood Glucose; Corn Oil; Fatty Acids; Female; Glucagon; Glucagon-Like Peptide 1; Glucagon-Like Peptides; Glucose Tolerance Test; Glycerol; Insulin; Intubation, Gastrointestinal; Obesity; Peptide Fragments; Rats; Rats, Wistar; Reference Values; Triglycerides; Veins | 1999 |
Leptin suppression of insulin secretion and gene expression in human pancreatic islets: implications for the development of adipogenic diabetes mellitus.
Previously we demonstrated the expression of the long form of the leptin receptor in rodent pancreatic beta-cells and an inhibition of insulin secretion by leptin via activation of ATP-sensitive potassium channels. Here we examine pancreatic islets isolated from pancreata of human donors for their responses to leptin. The presence of leptin receptors on islet beta-cells was demonstrated by double fluorescence confocal microscopy after binding of a fluorescent derivative of human leptin (Cy3-leptin). Leptin (6.25 nM) suppressed insulin secretion of normal islets by 20% at 5.6 mM glucose. Intracellular calcium responses to 16.7 mM glucose were rapidly reduced by leptin. Proinsulin messenger ribonucleic acid expression in islets was inhibited by leptin at 11.1 mM, but not at 5.6 mM glucose. Leptin also reduced proinsulin messenger ribonucleic acid levels that were increased in islets by treatment with 10 nM glucagon-like peptide-1 in the presence of either 5.6 or 11.1 mM glucose. These findings demonstrate direct suppressive effects of leptin on insulin-producing beta-cells in human islets at the levels of both stimulus-secretion coupling and gene expression. The findings also further indicate the existence of an adipoinsular axis in humans in which insulin stimulates leptin production in adipocytes and leptin inhibits the production of insulin in beta-cells. We suggest that dysregulation of the adipoinsular axis in obese individuals due to defective leptin reception by beta-cells may result in chronic hyperinsulinemia and may contribute to the pathogenesis of adipogenic diabetes. Topics: Calcium; Carrier Proteins; Cells, Cultured; Diabetes Mellitus; Gene Expression; Glucagon; Glucagon-Like Peptide 1; Glucose; Humans; Insulin; Insulin Secretion; Islets of Langerhans; Leptin; Obesity; Peptide Fragments; Potassium Channels; Proinsulin; Protein Precursors; Proteins; Receptors, Cell Surface; Receptors, Leptin; RNA, Messenger | 1999 |
Inhibition of carbohydrate-mediated glucagon-like peptide-1 (7-36)amide secretion by circulating non-esterified fatty acids.
Two studies were performed to assess the entero-insular axis in simple obesity and the possible effect of variations in the level of circulating non-esterified fatty acids (NEFA) on one of the components of the entero-insular axis, glucagon-like peptide-1 [(7-36) amide]. In the first study, we compared the entero-pancreatic hormone response to oral carbohydrate in obese and lean women. Obese subjects demonstrated hyperinsulinaemia and impaired glucose tolerance but this was not associated with an increased secretion of either glucose-dependent insulinotropic polypeptide or glucagon-like peptide-1 (GLP-1). These findings therefore provide no support for the hypothesis that overactivity of the entero-insular axis contributes to the hyperinsulinaemia seen in obesity. Indeed, the plasma GLP-1 response to carbohydrate was markedly attenuated in obese subjects, confirming previous observations. In the second study, in which carbohydrate-stimulated GLP-1 responses were again evaluated in obese and lean women, circulating NEFA levels were modulated using either heparin (to increase serum NEFA) or acipimox (to reduce serum NEFA). Treatment with acipimox resulted in complete suppression of NEFA levels and in a markedly higher GLP-1 response than the response to carbohydrate alone or to carbohydrate plus heparin. We suggest that higher fasting and postprandial NEFA levels in obesity may tonically inhibit nutrient-mediated GLP-1 secretion, and that this results in attenuation of the GLP-1 response to carbohydrate. However, although serum NEFA levels post-acipimox were similarly suppressed in both lean and obese subjects, the GLP-1 response was again significantly lower in obese subjects, suggesting the possibility of an intrinsic defect of GLP-1 secretion in obesity. The reduction of GLP-1 levels in obesity may be important both in relation to its insulinotropic effect and to its postulated role as a satiety factor. Topics: Adult; Analysis of Variance; Area Under Curve; Case-Control Studies; Dietary Carbohydrates; Fatty Acids, Nonesterified; Female; Gastric Inhibitory Polypeptide; Glucagon; Glucagon-Like Peptide 1; Glucagon-Like Peptides; Glucose Tolerance Test; Heparin; Humans; Insulin; Models, Biological; Neurotransmitter Agents; Obesity; Peptide Fragments; Postprandial Period; Pyrazines; Triglycerides | 1999 |
The effect of circulating non-esterified fatty acids on the entero-insular axis.
Circulating non-esterified fatty acids (NEFAs) have been causally associated with impairment of glucose metabolism, although their effect on the entero-insular axis, either in obesity or health, is unknown.. Glucose, insulin, glucagon-like peptide-1 (7-36 amide) (GLP-1) and glucose-dependent insulinotropic polypeptide (GIP) responses to 100 g of carbohydrate in 400 mL water were evaluated during simultaneous modulation of circulating non-esterified fatty acids (NEFAs). A total of 10,000 units of heparin (to increase serum NEFAs) and 500 mg of acipimox (2 h before oral carbohydrate ingestion to reduce serum NEFAs) were administered to seven obese [mean +/- SEM: age 40 +/- 3.7 years; body mass index (BMI) 38.9 +/- 2.1 kg m-2] and seven lean (age 39.6 +/- 3.6 years; BMI 22.4 +/- 0.4 kg m-2) women.. Higher fasting levels and post-heparin total integrated NEFAs (P < 0.05) and glycerol (P < 0.05) responses were seen in the obese than in the lean group. Incremental integrated GLP-1 responses to oral carbohydrate post-heparin in lean (P < 0.01) and obese (P < 0.05) subjects were significantly lower than after acipimox. Total integrated GIP (P < 0.05) and glucose (P < 0.01) responses were higher post heparin than after acipimox in obese subjects only.. The inverse relationship in GIP and GLP-1 responses in the obese group after modulation of NEFAs indicates that reciprocal changes between these two hormones may exist to ensure constancy of B-cell stimulation. Our results suggest that in obese subjects compensatory secretion of GIP was incomplete and could not prevent impairment in glucose tolerance after heparin-induced rise in NEFAs. These results may be important in understanding the role of the insulinotropic hormones in carbohydrate metabolism characterized by high NEFA levels such as obesity and diabetes mellitus. Topics: Adult; Blood Glucose; Dietary Carbohydrates; Fatty Acids, Nonesterified; Female; Gastric Inhibitory Polypeptide; Glucagon; Glucagon-Like Peptide 1; Glucose Tolerance Test; Heparin; Humans; Insulin; Intestines; Islets of Langerhans; Obesity; Peptide Fragments; Protein Precursors; Pyrazines | 1999 |
Linkage analysis of candidate obesity genes among the Mexican-American population of Starr County, Texas.
Recent advances in the molecular basis of body fat regulation have identified several genes in which genetic variation may influence obesity and related measures in human populations. Genes that have been shown to have a regulatory function in the control of body fat utilization, eating behavior, and/or metabolic rate in rodent models of obesity include leptin (LEP), leptin receptor (LEPR), neuropeptide Y (NPY), NPY Y1 receptor (NPYY1), glucagon-like peptide-1 (GLP-1), GLP-1 receptor (GLP1R), and uncoupling protein 1 (UCP1). We have typed microsatellite markers located within or near these seven candidate obesity genes in 302 non-diabetic individuals from 59 Mexican-American families from Starr County, Texas. Sib pair linkage analysis was used to examine linkage between these genes and obesity status (obese siblings only; n = 170 pairs) and several obesity-related quantitative variables (all siblings; n = 545 total sibling pairs). Significant linkage (P = 0.042) was found between obesity and NPY within the obese sibling pairs. No other candidate gene was linked to obesity status in this subsample. Consistent with the obese sib pair linkage results, NPY showed evidence of linkage to body weight (P = 0.020), abdominal circumference (P = 0.031), hip circumference (P = 0.012), diastolic blood pressure (P = 0.005), and a composite measure of body mass and size (P = 0.048) in the entire sibling sample. Other significant linkages observed were between LEP and waist/hip ratio (P = 0.010), total cholesterol (P = 0.030), and HDL cholesterol (P = 0.026) and between LEPR and fasting blood glucose (P = 0.018) and diastolic blood pressure (P = 0.003). These results support further investigation of NPY, LEP, and LEPR to identify genetic variation that may influence obesity status, glucose and lipid metabolism, and blood pressure in Mexican Americans. Topics: Adult; Anthropometry; Carrier Proteins; Case-Control Studies; Chromosome Mapping; Female; Gene Frequency; Genetic Variation; Glucagon; Glucagon-Like Peptide 1; Glucagon-Like Peptide-1 Receptor; Humans; Ion Channels; Leptin; Male; Membrane Proteins; Mexican Americans; Microsatellite Repeats; Middle Aged; Mitochondrial Proteins; Neuropeptide Y; Obesity; Pedigree; Peptide Fragments; Protein Precursors; Proteins; Receptors, Cell Surface; Receptors, Glucagon; Receptors, Leptin; Receptors, Neuropeptide Y; Texas; Uncoupling Protein 1 | 1999 |
Peptides as drugs.
Topics: Anti-Bacterial Agents; Glucagon; Glucagon-Like Peptide 1; Growth Substances; Humans; Insulin; Interferons; Leptin; Obesity; Peptide Fragments; Peptides; Protein Precursors; Proteins | 1999 |
Glucose-lowering and insulin-sensitizing actions of exendin-4: studies in obese diabetic (ob/ob, db/db) mice, diabetic fatty Zucker rats, and diabetic rhesus monkeys (Macaca mulatta).
Exendin-4 is a 39 amino acid peptide isolated from the salivary secretions of the Gila monster (Heloderma suspectum). It shows 53% sequence similarity to glucagon-like peptide (GLP)-1. Unlike GLP-1, exendin-4 has a prolonged glucose-lowering action in vivo. We compared the potency and duration of glucose-lowering effects of exendin-4 and GLP-1 in hyperglycemic db/db and ob/ob mice. Whereas reductions in plasma glucose of up to 35% vanished within 1 h with most doses of GLP-1, the same doses of exendin-4 resulted in a similar glucose-lowering effect that persisted for >4 h. Exendin-4 was 5,530-fold more potent than GLP-1 in db/db mice (effective doses, 50% [ED50s] of 0.059 microg/kg +/-0.15 log and 329 microg/kg+/-0.22 log, respectively) and was 5,480-fold more potent in ob/ob mice (ED50s of 0.136 microg/kg+/-0.10 log and 744 microg/kg+/-0.21 log, respectively) when the percentage fall in plasma glucose at 1 h was used as the indicator response. Exendin-4 dose-dependently accelerated glucose lowering in diabetic rhesus monkeys by up to 37% with an ED50 of 0.25 microg/kg +/-0.09 log. In two experiments in which diabetic fatty Zucker rats were injected subcutaneously twice daily for 5-6 weeks with doses of exendin-4 up to 100 microg x rat(-1) x day(-1) (approximately 250 microg/kg), HbA1c was reduced relative to saline-injected control rats. Exendin-4 treatment was also associated in each of these experiments with weight loss and improved insulin sensitivity, as demonstrated by increases of up to 32 and 49%, respectively, in the glucose infusion rate (GIR) in the hyperinsulinemic euglycemic clamp. ED50s for weight loss and the increase in clamp GIR were 1.0 microg/kg+/-0.15 log and 2.4 microg/kg+/-0.41 log, respectively. In conclusion, acute and chronic administration of exendin-4 has demonstrated an antidiabetic effect in several animal models of type 2 diabetes. Topics: Animals; Blood Glucose; Diabetes Mellitus; Dose-Response Relationship, Drug; Exenatide; Female; Glucagon; Glucagon-Like Peptide 1; Glycated Hemoglobin; Hypoglycemic Agents; Insulin; Kinetics; Macaca mulatta; Male; Mice; Mice, Inbred C57BL; Mice, Obese; Obesity; Peptide Fragments; Peptides; Protein Precursors; Rats; Rats, Zucker; Sequence Homology; Venoms | 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 dipeptidyl peptidase IV with NVP-DPP728 increases plasma GLP-1 (7-36 amide) concentrations and improves oral glucose tolerance in obese Zucker rats.
The potent incretin hormone glucagon-like peptide 1 (GLP-1) plays a pivotal role in prandial insulin secretion. In the circulation GLP-1 (7-36) amide is, however, rapidly (t(1/2):1-2 min) inactivated by the protease dipeptidyl peptidase IV (DPP-IV). We therefore investigated whether DPP-IV inhibition is a feasible approach to improve glucose homeostasis in insulin resistant, glucose intolerant fatty Zucker rats, a model of mild Type II (non-insulin-dependent) diabetes mellitus.. An oral glucose tolerance test was done in lean and obese male Zucker rats while plasma DPP-IV was inhibited by the specific and selective inhibitor NVP-DPP728 given orally.. Inhibition of DPP-IV resulted in a significantly amplified early phase of the insulin response to an oral glucose load in obese fa/fa rats and restoration of glucose excursions to normal. In contrast, DPP-IV inhibition produced only minor effects in lean FA/? rats. Inactivation of GLP-1 (7-36) amide was completely prevented by DPP-IV inhibition suggesting that the effects of this compound on oral glucose tolerance are mediated by increased circulating concentrations of GLP-1 (7-36) amide. Reduced gastric emptying, as monitored by paracetamol appearance in the circulation after an oral bolus, did not appear to have contributed to the reduced glucose excursion.. It is concluded that NVP-DPP728 inhibits DPP-IV and improves insulin secretion and glucose tolerance, probably through augmentation of the effects of endogenous GLP-1. The improvement observed in prandial glucose homeostasis during DPP-IV inhibition suggests that inhibition of this enzyme is a promising treatment for Type II diabetes. [Diabetologia (1999) 42: 1324-1331] Topics: Animals; Dipeptidyl Peptidase 4; Glucagon; Glucagon-Like Peptide 1; Glucagon-Like Peptides; Glucose; Glucose Tolerance Test; Male; Nitriles; Obesity; Osmolar Concentration; Peptide Fragments; Pyrrolidines; Rats; Rats, Zucker; Reference Values | 1999 |
Intraventricular GLP-1 reduces short- but not long-term food intake or body weight in lean and obese rats.
Glucagon-like-peptide-1 (7-36) amide (GLP-1), when infused into the third ventricle (I.V.T.), reduces short-term food intake. In the present experiments, we assessed whether I.V.T. administration of GLP-1 could influence long-term food intake and body weight of lean Long Evans rats and of fatty Zucker (fa/fa) rats. In Experiment 1, we replicated the observation that 10 microg GLP-1, given I.V.T., reduces one and 2 h food intake, and extended the observation to fatty Zucker rats. However, in both rat strains, 24 h food intake and body weight were unchanged by this acute treatment. In Experiment 2, GLP-1 (30 microg/day) was infused I.V.T. continuously for 4 days via an osmotic mini-pump. This treatment also had no effect on food intake or body weight in either Long-Evans or fatty Zucker rats. A control experiment verified that the GLP-1 remained biologically active over the duration of the infusion period. In a final experiment, Long-Evans rats were restricted to two 2 h periods of access to food each day for 6 days. Prior to each of these access periods, rats received either 15 microg of GLP-1 I.V.T. or a vehicle control injection. While GLP-1 significantly reduced food intake on the first day of treatment, this effect of GLP-1 rapidly disappeared such that it was reduced on the second day and absent on the third day; and there was no effect on body weight at any time. Collectively, the present experiments do not support the hypothesis that GLP-1, acting in the CNS, is an important regulator of long-term food intake and body weight. Topics: Analysis of Variance; Animals; Body Weight; Cerebral Ventricles; Feeding Behavior; Glucagon; Glucagon-Like Peptide 1; Infusion Pumps, Implantable; Male; Obesity; Peptide Fragments; Protein Precursors; Rats; Rats, Zucker; Time Factors | 1998 |
Effect of chronic central administration of glucagon-like peptide-1 (7-36) amide on food consumption and body weight in normal and obese rats.
Glucagon-like peptide (7-36) amide (GLP-1) acutely inhibits food and water consumption in rats after intracerebroventricular (icv) administration. To assess the potential for desensitization of these effects, we investigated the effects of chronic icv administration of GLP-1 on food consumption and body weight in Sprague-Dawley (SD) rats and Zucker (fa/fa) obese rats. In vitro functional densensitization of the GLP-1 receptor was not observed after overnight exposure of Rin m5F insulinoma cells to GLP-1 at concentrations up to 10 nM. Administration of GLP-1 to SD rats (30 microg icv twice a day for 6 days) resulted in significant reductions in 24-hour food consumption each day (25 +/- 1%). Continuous icv infusion of GLP-1 for 7 and 14 days significantly inhibited cumulative food consumption and reduced body weight in SD rats. In the genetically obese Zucker rat, chronic dosing with GLP-1 (30 microg icv) once a day for 6 days caused significant reductions in food consumption each day and a reduction in body weight. These results indicate that the GLP-1 pathways in the central nervous system controlling food consumption do not desensitize after chronic exposure to GLP-1 and suggest that agonists of the central GLP-1 receptor may be effective agents for the treatment of obesity. Topics: Animals; Body Weight; Eating; Glucagon; Glucagon-Like Peptide 1; Glucagon-Like Peptide-1 Receptor; Glucagon-Like Peptides; Injections, Intraventricular; Insulinoma; Male; Neurotransmitter Agents; Obesity; Pancreatic Neoplasms; Peptide Fragments; Rats; Rats, Sprague-Dawley; Rats, Zucker; Receptors, Glucagon; Tumor Cells, Cultured | 1998 |
Differential effects of intracerebroventricular glucagon-like peptide-1 on feeding and energy expenditure regulation.
Intracerebroventricular (i.c.v.) administration of glucagon-like peptide-1-(7-37) amide (GLP-1) has been shown to modulate food and water intake. The present studies further characterize the effects of i.c.v. GLP-1 in the regulation of energy balance in lean and obese animals. In both obese and lean Zucker rats, a single i.c.v. infusion of GLP-1 (1-30 microg) resulted in a dose-dependent reduction of food intake and decrease in respiratory quotient relative to the saline control during the first 2 h of the nocturnal cycle. In obese Zucker rats, the food intake was reduced by 73 +/- 11% of the control at the 30 microg dose, whereas a modest 45 +/- 18% reduction was observed in lean rats. Despite the large reduction in food intake seen with GLP-1, there was no compensatory decrease in nocturnal oxygen consumption in the obese Zucker rats. Interestingly, low doses of GLP-1 (1 microg) in lean Zucker rats, which had minimal effects on food intake, caused a 19 +/- 7% increase in O2 consumption during the first 2 h of the nocturnal cycle. These data suggest that central GLP-1 may be an important factor controlling negative energy balance in both the lean and obese Zucker rats. Topics: Analysis of Variance; Animals; Drinking Behavior; Energy Metabolism; Feeding Behavior; Glucagon; Glucagon-Like Peptide 1; Injections, Intraventricular; Male; Obesity; Peptide Fragments; Protein Precursors; Rats; Rats, Zucker | 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 |
Attenuated GLP-1 secretion in obesity: cause or consequence?
Hypersecretion of insulinotropic factors such as glucose dependent insulinotropic polypeptide (GIP) and glucagon-like peptide-1(7-36)amide (GLP-1) have been postulated to account for the hyperinsulinaemia of obesity.. To examine the role of GLP-1 and GIP in obese women and matched controls.. Six lean and six obese women subjects matched for age.. The gut hormone, plasma glucose, and serum triglyceride responses were studied over 180 minutes after oral carbohydrate and fat meals. Heparin (10,000 units) was given intravenously at 120 minutes.. There was pronounced attenuation of plasma GLP-1 secretion to oral carbohydrate in the obese compared with lean subjects but no such difference in response to oral fat load. There were no differences in the plasma GIP responses to carbohydrate or fat feeding. There was an apparent fall in plasma GLP-1 values in all subjects after administration of heparin.. Postprandial GLP-1 secretion in response to oral carbohydrate is considerably attenuated in obese subjects. The cause of this attenuation of GLP-1 secretion is not known although we suggest that both this fall and the overall reduction in GLP-1 values in obese subjects may be related to an increase in plasma non-esterified fatty acids. Topics: Adult; Case-Control Studies; Dietary Carbohydrates; Dietary Fats; Female; Gastric Inhibitory Polypeptide; Glucagon; Glucagon-Like Peptide 1; Glucagon-Like Peptides; Heparin; Humans; Obesity; Peptide Fragments; Radioimmunoassay | 1996 |
Altered glucose dependence of glucagon-like peptide I(7-36)-induced insulin secretion from the Zucker (fa/fa) rat pancreas.
In previous studies on the enteroinsular axis in Zucker rats, it was found that glucose-dependent insulinotropic polypeptide (GIP) levels were normal in obese animals, but the glucose threshold for the insulinotropic action of GIP in the perfused rat pancreas was reduced. Glucagon-like peptide I (GLP-I)(7-36) is also an important incretin, and in the current study, glucose, insulin, and immunoreactive (IR)-COOH-terminal GLP-I responses to oral glucose were compared in lean (Fa/?) and obese (fa/fa) rats. In addition, the concentration thresholds for stimulation and glucose dependence of perfused pancreases to GLP-I(7-36) were examined. Glucose responses to oral glucose were similar in fa/fa and Fa/? rats. Obese animals were hyperinsulinemic when fasting and after oral glucose. Significant increases in IR-GLP-I levels in response to glucose were only observed in fa/fa rats. Perfused pancreases from fa/fa rats hypersecreted insulin at all glucose concentrations. In the presence of 4.4 mmol/l glucose, GLP-I(7-36) increased insulin secretion in fa/fa pancreases approximately 25-fold, whereas there was only a 5-fold increase in Fa/? pancreases. Pancreases from fa/fa rats, perfused with a glucose gradient (2.8-11 mmol/l) in the presence of GLP-I(7-36), responded with an immediate increase in insulin secretion, i.e., at a glucose concentration of 2.8 mmol/l, whereas Fa/? pancreases required a minimum of 4.22 mmol/l glucose for stimulation. With high glucose (16.7 mmol/l), both fa/fa and Fa/? rat pancreases exhibited similar responsiveness to GLP-I(7-36), having thresholds of < 50 pmol/l.(ABSTRACT TRUNCATED AT 250 WORDS) Topics: Animals; Diabetes Mellitus, Experimental; Female; Glucagon; Glucagon-Like Peptide 1; Glucagon-Like Peptides; Glucose; Glucose Tolerance Test; In Vitro Techniques; Insulin; Insulin Secretion; Islets of Langerhans; Male; Obesity; Peptide Fragments; Perfusion; Rats; Rats, Zucker | 1995 |
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 |
Gastrointestinal peptides and insulin secretion.
Topics: Animals; Gastric Inhibitory Polypeptide; Gastrointestinal Hormones; Glucagon; Glucagon-Like Peptide 1; Glucagon-Like Peptides; Humans; Insulin; Insulin Secretion; Liver; Neuropeptides; Obesity; Peptide Fragments | 1987 |
Partial purification of an insulin-releasing activity in human serum.
An activity that enhances insulin release from perifused rat pancreatic islets has recently been isolated from human serum fractions (molecular weight 1,000-5,000 daltons). To characterize this activity we have studied the insulin-releasing effect of serum subfractions from obese and non-obese children obtained by reversed-phase high-performance liquid chromatography (HPLC). The serum insulin-releasing activity eluted in the HPLC system at 12-13 minutes, which corresponded to the retention time of the tridecapeptide insulin-glucagon liberin isolated from bovine hypothalamus. Insulin-releasing activity was found in serum subfractions from both obese and normal-weight children. The relative insulin-releasing potency of the active subfractions was higher than that of the original total serum fractions, indicating the presence of some substance(s) which inhibit insulin secretion in the total serum fractions. Oral glucose loading increased the relative insulin-releasing activity in the HPLC subfractions from obese children. This study suggests that the insulin secretagogue in human serum might be identical to hypothalamic insulin-glucagon liberin as these substances behave similarly on reversed-phase HPLC and have parallel insulin-releasing properties. Topics: Animals; Biological Assay; Child; Chromatography, High Pressure Liquid; Fasting; Glucagon; Glucagon-Like Peptide 1; Glucagon-Like Peptides; Glucose Tolerance Test; Humans; In Vitro Techniques; Intercellular Signaling Peptides and Proteins; Islets of Langerhans; Obesity; Peptide Fragments; Peptides; Rats; Rats, Inbred Strains | 1983 |