sitagliptin-phosphate and Obesity

Sitagliptin is known as an antidiabetic agent inhibiting the dipeptidyl peptidase-4. Although sitagliptin may influence weight, controversial results have been reported, and there is no general agreement on this issue. Therefore, this study assessed the effect of sitagliptin as monotherapy and add-on therapy to metformin on weight reduction in overweight or obese cases with type 2 diabetes.. We reviewed the following databases to identify all relevant papers published until 1st April 2021: Web of Science, MEDLINE, Embase, Scopus, Cochrane Central Register of Controlled Trials Cochrane Library, and Google Scholar. The research included all clinical trials investigating the effect of sitagliptin in obese or overweight adult patients with type 2 diabetes without any language restriction.. In total, eighteen randomized controlled trials with 2009 participants were included in our meta-analysis. Results showed supplementation of sitagliptin has led to weight loss for sitagliptin treated (MD  -0.99; 95% CI; (-1.87, -0.12); p=0.026)) and sitagliptin+metformin treated groups (MD  -1.09; 95% CI; (-1.69, -0.49); p<0.001)). Also, the intervention has influenced body mass index in sitagliptin treated (MD  -0.23; 95% CI; (-0.45, 0.02); p=0.033)) and sitagliptin+metformin treated groups (MD -0.52; 95% CI; (-0.96, 0.08); p=0.020)) comparing to placebo.. Our results demonstrated that sitagliptin administration with or without metformin might reduce the body weight and body mass index if these drugs are taken for more than 6 months.

Topics: Adult; Diabetes Mellitus, Type 2; Drug Therapy, Combination; Glycated Hemoglobin; Humans; Hypoglycemic Agents; Metformin; Obesity; Overweight; Randomized Controlled Trials as Topic; Sitagliptin Phosphate; Weight Loss

The purpose of this study was to assess the efficacy and hypoglycemic risk of sitagliptin versus that of GLP-1 receptor agonists in the management of obese/overweight patients with T2DM.. EMBASE, PubMed, Cochrane Library, and ClinicalTrials.gov were searched; randomized controlled trials comparing the efficacy of sitagliptin versus that of GLP-1 receptor agonists in obese/overweight patients with T2DM were included. The mean BMI of participants for each study was ≥30 kg/m. We conducted a meta-analysis according to the methods specified in the Cochrane Handbook for Systematic Reviews of Interventions. RevMan 5.1 software was used to perform the meta-analysis. The Cochrane Q test and I statistics were used to estimate the heterogeneity among studies. The results are expressed as the mean difference (MD) or risk ratio (RR) with 95% confidence intervals.. A total of 8 eligible studies were included in our meta-analysis. Compared with GLP-1 receptor agonists, sitagliptin was less effective at reducing HbA1c (0.42 [0.27, 0.56]), FPG (0.78 [0.36, 1.19]), PPG (2.61 [1.35, 3.87]), and body weight (1.42 [0.71, 2.14]). Conversely, there were no significant differences in SBP reduction (0.38 [-1.14, 1.89]), DBP reduction (-0.30 [-1.00, 0.39]), and hypoglycemic risk (1.09 [0.50, 2.35]).. For obese/overweight patients, sitagliptin may exert a less potent effect on HbA1C, FPG, PPG, and weight reduction than GLP-1 receptor agonists, but these drugs had a similar efficacy in reducing blood pressure; furthermore, there was no significant difference in hypoglycemic risk.

Topics: Blood Glucose; Blood Pressure; Body Weight; Diabetes Mellitus, Type 2; Glucagon-Like Peptide-1 Receptor; Humans; Hypoglycemia; Hypoglycemic Agents; Obesity; Sitagliptin Phosphate

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

To test the hypothesis that glucagon-like peptide-1 receptor (GLP-1R) agonists have beneficial effects on vascular endothelial function, fibrinolysis and inflammation through weight loss-independent mechanisms.. Individuals with obesity and prediabetes were randomized to 14 weeks of the GLP-1R agonist liraglutide, hypocaloric diet or the dipeptidyl peptidase-4 inhibitor sitagliptin in a 2:1:1 ratio. Treatment with drug was double blind and placebo-controlled. Measurements were made at baseline, after 2 weeks prior to significant weight loss and after 14 weeks. The primary outcomes were measures of endothelial function: flow-mediated vasodilation (FMD), plasminogen activator inhibitor-1 (PAI-1) and urine albumin-to-creatinine ratio (UACR).. Eighty-eight individuals were studied (liraglutide N = 44, diet N = 22, sitagliptin N = 22). Liraglutide and diet reduced weight, insulin resistance and PAI-1, while sitagliptin did not. There was no significant effect of any treatment on endothelial vasodilator function measured by FMD. Post hoc subgroup analyses in individuals with baseline FMD below the median, indicative of greater endothelial dysfunction, showed an improvement in FMD by all three treatments. GLP-1R antagonism with exendin (9-39) increased fasting blood glucose but did not change FMD or PAI-1. There was no effect of treatment on UACR. Finally, liraglutide, but not sitagliptin or diet, reduced the chemokine monocyte chemoattractant protein-1 (MCP-1).. Liraglutide and diet reduce weight, insulin resistance and PAI-1. Liraglutide, sitagliptin and diet do not change FMD in obese individuals with prediabetes with normal endothelial function. Liraglutide alone lowers the pro-inflammatory and pro-atherosclerotic chemokine MCP-1, indicating that this beneficial effect is independent of weight loss.

Topics: Diet, Reducing; Fibrinolysis; Glucagon-Like Peptide-1 Receptor; Humans; Hypoglycemic Agents; Incretins; Inflammation; Insulin Resistance; Liraglutide; Obesity; Plasminogen Activator Inhibitor 1; Prediabetic State; Sitagliptin Phosphate; Weight Loss

To investigate the hypothesis that weight loss with the glucagon-like peptide-1 receptor agonist (GLP-1RA) liraglutide alone would lead to a greater reduction in the proportion of fat to lean tissue mass when compared to caloric restriction (CR) alone, as well as when compared to treatment with sitagliptin, a dipeptidyl peptidase-4 (DPP-4) inhibitor, that also enhances GLP-1 activity - to determine the independent effects of each treatment.. A total of 88 adults with obesity and prediabetes were randomized to 14 weeks of intervention with CR (-390 kcal/d), liraglutide (1.8 mg/d), or the dipeptidyl peptidase-4 inhibitor sitagliptin (100 mg/d) as a weight-neutral comparator. Changes between groups in appetite and hunger ratings measured via visual analogue scales, dietary intakes, body weight, body composition via dual energy x-ray absorptiometry, and resting energy expenditure via indirect calorimetry were assessed using the Kruskal-Wallis test or Pearson's chi-squared test.. Weight loss ≥5% of baseline body weight occurred in 44% of participants in the CR group, 22% of the liraglutide group and 5% of the sitagliptin group (p = 0.02). The ratio of fat to lean mass decreased by 6.5% in the CR group, 2.2% in the liraglutide group, and 0% in the sitagliptin group (p = 0.02). Visceral fat reduced by 9.5% in the CR group, 4.8% in the liraglutide group, and 0% in the sitagliptin group (p = 0.04). A spontaneous reduction in dietary simple carbohydrates in the CR group was associated with improved homeostatic model assessment of insulin resistance score (HOMA-IR).. Although both liraglutide and CR are valuable strategies for cardiometabolic risk reduction, CR was associated with greater weight loss and more favourable improvements in body composition than treatment with liraglutide alone. Differences in the response to each of these interventions enables patients to be stratified to the most optimal intervention for their personal risk factors.

Topics: Adult; Appetite; Body Fat Distribution; Body Weight; Caloric Restriction; Cardiovascular Diseases; Diabetes Mellitus, Type 2; Dipeptidyl-Peptidase IV Inhibitors; Dipeptidyl-Peptidases and Tripeptidyl-Peptidases; Eating; Glucagon-Like Peptide-1 Receptor; Humans; Hypoglycemic Agents; Liraglutide; Obesity; Prediabetic State; Sitagliptin Phosphate; Weight Loss

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

To compare the effects of a glucagon-like peptide-1 receptor agonist and a dipeptidyl peptidase-4 inhibitor on magnetic resonance imaging-derived measures of cardiovascular function.. In a prospective, randomized, open-label, blinded endpoint trial liraglutide (1.8 mg) and sitagliptin (100 mg) were compared in asymptomatic, non-insulin treated young (aged 18-50 years) adults with obesity and type 2 diabetes. The primary outcome was difference in circumferential peak early diastolic strain rate change (PEDSR), a biomarker of cardiac diastolic dysfunction 26 weeks after randomization. Secondary outcomes included other indices of cardiac structure and function, HbA1c and body weight.. Seventy-six participants were randomized (54% female, mean ± SD age 44 ± 6 years, diabetes duration 4.4 years, body mass index 35.3 ± 6.1 kg m. There were no differences in cardiovascular structure or function after short-term use of liraglutide and sitagliptin in younger adults with obesity and type 2 diabetes. Longer studies in patients with more severe cardiac dysfunction may be necessary before definitive conclusions can be made about putative pleiotropic properties of incretin-based therapies.

Topics: Adult; Diabetes Mellitus, Type 2; Female; Glycated Hemoglobin; Humans; Hypoglycemic Agents; Liraglutide; Male; Middle Aged; Obesity; Prospective Studies; Sitagliptin Phosphate; Stroke Volume; Treatment Outcome; Ventricular Function, Left

Metformin has an established role in the management of polycystic ovary syndrome (PCOS). Some patients cannot tolerate it due to associated gastrointestinal adverse events. The present study evaluated the dipeptidyl peptidase 4 inhibitor sitagliptin as a potential treatment option in metformin-intolerant PCOS.. We conducted a 12-week, prospective, randomized, open-label study with 30 obese metformin-intolerant women with PCOS (age 35.0 ± 7.2 years; body mass index, 36.9 ± 5.5 kg/m. SITA improved beta-cell function as assessed by the homeostasis model assessment for beta-cell function index (HOMA-B) of 45.9 ± 35.8 ( P = .001), modified beta-cell function index (MBCI) of 7.9 ± 7 ( P = .002), and quantitative insulin-sensitivity check index (QUICKI) of -0.03 ± 0.03 ( P = .002). By contrast, beta-cell function decreased in CON. The between-group differences were significant for HOMA-B ( P = 0.001), MBCI ( P = .010), and QUICKI ( P = .025). The conversion rate to impaired glucose homeostasis was prevented in SITA: 3 of 15 subjects had impaired glucose tolerance (IGT) before and after the study. In CON, none had type 2 diabetes (T2D), and 4 had IGT at the beginning. After 12 weeks, IGT was observed in 2 and T2D in 3 subjects.. SITA improved beta-cell function and prevented a conversion to IGT and T2D in metformin-intolerant obese PCOS patients.. BMI = body mass index; DPP-4 = dipeptidyl peptidase-4; DXA = dual energy X-ray absorptiometry; GIP = glucose-dependent insulinotropic peptide; GLP-1 = glucagon-like peptide-1; HOMA-B = homeostasis model assessment for beta-cell function; HOMA-IR = homeostasis model assessment of insulin resistance; IAI = insulin action index; IGT = impaired glucose tolerance; IR = insulin resistance; MBCI = modified beta-cell function index; OGTT = oral glucose tolerance test; QUICKI = quantitative insulin sensitivity check index; PCOS = polycystic ovary syndrome; SHBG = sex hormone-binding globulin; T2D = type 2 diabetes.

Topics: Absorptiometry, Photon; Adult; Body Composition; Diabetes Mellitus, Type 2; Dipeptidyl-Peptidase IV Inhibitors; Disease Progression; Female; Glucose Intolerance; Glucose Tolerance Test; Humans; Insulin Resistance; Insulin-Secreting Cells; Life Style; Obesity; Pilot Projects; Polycystic Ovary Syndrome; Sitagliptin Phosphate

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

To compare the therapeutic effects of different regimens in Chinese obese type 2 diabetic mellitus (T2DM) patients. From October 2013 to July 2014, a total of 166 T2DM outpatients who attended the Shanghai Changhai Hospital and the Yijishan Hospital of Wannan Medical College were randomly assigned into an experimental sitagliptin/metformin combined with low caloric diet group (n = 115) and an insulin glargine combined with metformin control group (n = 51). Inclusion criteria were body mass index (BMI) ≥ 25 kg/m and diagnosed with T2DM with glycosylated hemoglobin (glycated hemoglobin A1C [HbA1c]) >9%. Main outcome parameters were fasting plasma glucose, postprandial plasma glucose, BMI, HbA1c, fasting C-peptide, 2-h postprandial C-peptide, triglyceride (TG), total cholesterol (TC), high-density cholesterol (HDL-C), and low-density cholesterol (LDL-C), which were determined by the 75 g steamed-bun meal tolerance test before and 4, 8, 12, and 24 weeks after the treatment started. Treatment costs and life quality were also assessed. BMI, HbA1C, TG, TC, and LDL were significantly more reduced (P < 0.000) and HbA1c significantly better improved in the experimental group than in the control group (<6.5% in 24 [20.87%] vs 2 [3.92%], P < 0.001; <7% in 65 [56.52%] vs 12 [23.53%], P < 0.001). Quality of life scores in the experimental group increased more than in the control group (P < 0.001). The costs for the experimental group medication were less than for other regimens. For obese T2DM patients diagnosed with a glycosylated hemoglobin level >9%, oral sitagliptin/metformin combined with a low caloric diet effectively and economically maintained glycemic control and significantly improved life quality.

Topics: Adult; Aged; Body Mass Index; Diabetes Mellitus, Type 2; Drug Monitoring; Drug Therapy, Combination; Female; Glycated Hemoglobin; Humans; Hypoglycemic Agents; Insulin Glargine; Male; Metformin; Middle Aged; Obesity; Sitagliptin Phosphate; Treatment Outcome

After intensive insulin treatment, many obese African American patients with new-onset diabetic ketoacidosis (DKA) and severe hyperglycemia are able to achieve near-normoglycemia remission. The optimal treatment to prevent hyperglycemic relapses after remission is not known.. Relapse-free survival was higher in sitagliptin and metformin (P = 0.015) compared with placebo, and mean time to relapse was significantly prolonged in the metformin and sitagliptin groups compared with the placebo group (480 vs. 305 days, P = 0.004). The probability of relapse was significantly lower for metformin (hazard ratio 0.28 [95% CI 0.10-0.81]) and sitagliptin (0.31 [0.10-0.98]) than for placebo. Subjects who remained in remission had a higher DI (P = 0.02) and incremental AUCi (P < 0.001) than those with hyperglycemia relapse without significant changes in Si.. This study shows that near-normoglycemia remission was similarly prolonged by treatment with sitagliptin and metformin. The prolongation of remission was due to improvement in β-cell function.

Topics: Adolescent; Adult; Black or African American; Body Mass Index; Diabetes Mellitus, Type 2; Diabetic Ketoacidosis; Female; Follow-Up Studies; Glucose Tolerance Test; Humans; Hyperglycemia; Hypoglycemic Agents; Insulin Resistance; Longitudinal Studies; Male; Metformin; Middle Aged; Obesity; Prospective Studies; Single-Blind Method; Sitagliptin Phosphate; Young Adult

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

This study evaluated if triple oral therapy can be useful in improving glycemic control compared with metformin monotherapy and with a metformin and pioglitazone combination. Furthermore, we also compared a triple metformin+pioglitazone+glibenclamide combination with a metformin+pioglitazone+sitagliptin one.. After a 2-year run-in therapy-augmenting phase with metformin and pioglitazone, 453 overweight, type 2 diabetes patients were randomized to 1 year of sitagliptin versus 1 year of glibenclamide to evaluate, as the primary outcome, the variation of β-cell function both in a fasting state and after an euglycemic hyperinsulinemic and hyperglycemic clamp. As secondary outcomes we evaluated glycemic control and insulin resistance.. Both the triple therapy combinations were more effective in reducing glycated hemoglobin compared with metformin monotherapy and with dual therapy metformin+pioglitazone. Fasting plasma insulin level and the homeostasis model assessment insulin resistance index were significantly increased by triple therapy with glibenclamide and decreased by the one with sitagliptin. Although sitagliptin did not change the homeostasis model assessment β-function index, this value was significantly increased by glibenclamide. The fasting plasma proinsulin level was decreased by sitagliptin. Triple therapy with sitagliptin greatly improved β-cell function measures compared with the glibenclamide one and also compared with metformin monotherapy and with the metformin+pioglitazone combination.. Dual combination therapy is more effective than monotherapy in improving glycemic control. When double therapy is not enough to reach an adequate glycemic control, sitagliptin should be preferred to glibenclamide as the third agent because of its positive effect on β-cells.

Topics: Blood Glucose; Diabetes Mellitus, Type 2; Double-Blind Method; Drug Therapy, Combination; Fasting; Female; Glyburide; Glycated Hemoglobin; Humans; Hypoglycemic Agents; Insulin Resistance; Male; Metformin; Obesity; Pioglitazone; Pyrazines; Sitagliptin Phosphate; Thiazolidinediones; Treatment Outcome; Triazoles

Dipeptidyl peptidase-4 (DPP-4) inhibitors are a new class of antihyperglycemic drugs that block degradation ofincretin hormones.. To assess the effects oftreatment with DPP-4 inhibitors on glucoregulation and body weight in obese patients with type 2 diabetes mellitus.. The study included 9 females and 9 males with type 2 diabetes (n=18), BMI=31.24 +/- 2,26 kg/m2, mean age 58 +/- 6,8 years. The patients have been thoroughly evaluated before treatment, and 6 months after treatment with DPP-4 inhibitor (sitagliptin) in combination with metformin.. After 6 months of treatment with DPP-4 inhibitors in combination with metformin HbAlc (-1,49%)., FBG (-3.75 mmol/L) and PBG (-5.79 mmol/L) significantly reduced (p=0.000). Mean body weight also significantly reduced (-12.5%; p=0.000). Reduction of mean fasting insulin was 5.46 mIU/L or 27% (p=0.000). Mean HOMA-IR change was -1.64 (p=0.000). Also there was significant decreasing of systolic blood pressure (p=0.001), cholesterol (p=0.004), triglycerides (p=0.001), LDL (p=0.002) and increasing of HDL (p=0.002). Hypoglycaemia was not registered in any of the patients.. These results show that in obese patients with type 2 diabetes, DPP-4 inhibitors treatment in combination with metformin was associated with improvements in glycaemic control, and a reduction in body weight.

Topics: Adult; Aged; Blood Glucose; Blood Pressure; Body Mass Index; Body Weight; Cholesterol, LDL; Diabetes Mellitus, Type 2; Dipeptidyl-Peptidase IV Inhibitors; Drug Therapy, Combination; Female; Glycated Hemoglobin; Humans; Hypoglycemic Agents; Insulin Resistance; Male; Metformin; Middle Aged; Obesity; Pyrazines; Sitagliptin Phosphate; Treatment Outcome; Triazoles; Triglycerides

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

GPR55 has been recognized as a novel anti-diabetic target exerting positive effects on beta cell function and mass. This study evaluated the metabolic actions and therapeutic efficacy of GPR55 agonist abnormal cannabidiol (Abn-CBD) administered alone and in combination with sitagliptin in diet-induced obese-diabetic mice. Chronic effects of 21-day oral administration of Abn-CBD (0.1 µmol/kg BW) monotherapy and in combination with sitagliptin (50 mg/kg BW) were assessed in obese-diabetic HFF mice (n = 8). Assessments of plasma glucose, circulating insulin, DPP-IV activity, CRP, amylase, lipids, body weight and food intake were undertaken. Glucose tolerance, insulin sensitivity, DEXA scanning and islet morphology analysis were performed at 21-days. Sitagliptin, Abn-CBD alone and in combination with sitagliptin attenuated plasma glucose by 37-53 % (p < 0.01 - p < 0.001) and enhanced circulating insulin concentrations by 23-31 % (p < 0.001). Abn-CBD alone and with sitagliptin reduced bodyweight by 9-10 % (p < 0.05). After 21-days, Abn-CBD in combination with sitagliptin (44 %; p < 0.01) improved glucose tolerance, whilst enhancing insulin sensitivity by 79 % (p < 0.01). Abn-CBD increased islet area (86 %; p < 0.05), beta cell mass (p < 0.05) and beta cell proliferation (164 %; p < 0.001), whilst in combination with sitagliptin islet area was decreased (50 %; p < 0.01). Abn-CBD alone, in combination with sitagliptin or sitagliptin alone decreased triglycerides by 34-65 % (p < 0.001) and total cholesterol concentrations by 15-25 % (p < 0.001). In addition, Abn-CBD in combination with sitagliptin reduced fat mass by 19 % (p < 0.05) and reduced CRP concentrations (39 %; p < 0.05). These findings advocate Abn-CBD monotherapy and in combination with sitagliptin as a novel and effective approach for bodyweight control and the treatment of glucose intolerance and dyslipidaemia in type-2-diabetes.

Topics: Animals; Blood Glucose; Diabetes Mellitus, Experimental; Hypoglycemic Agents; Insulin; Insulin Resistance; Mice; Obesity; Receptors, Cannabinoid; Sitagliptin Phosphate

Topics: Diabetes Mellitus, Type 2; Drug Interactions; Humans; Hypoglycemic Agents; Obesity; Sitagliptin Phosphate

Dipeptidyl peptidase-4 inhibitors have limited efficacy in improving glycemic control for obese Japanese patients with type 2 diabetes mellitus. Sodium-glucose co-transporter 2 inhibitors are recommended for use in patients with type 2 diabetes with obesity. Nevertheless, there has been no previously published study on the effect of switching from dipeptidyl peptidase-4 inhibitors to sodium-glucose co-transporter 2 inhibitors on the systemic and organic effects in obese Japanese patients with type 2 diabetes.. We evaluated the efficacy and safety of switching from sitagliptin to ipragliflozin for 24 weeks in obese Japanese patients with inadequately controlled type 2 diabetes.. Fifty-one obese patients with type 2 diabetes (body mass index > 25 kg/m. Switching from sitagliptin to ipragliflozin did not alter HbA1c in obese patients with type 2 diabetes, while improving parameters related to organ homeostasis. These data provide novel information useful for selecting oral anti-diabetic agents for patients with type 2 diabetes with obesity, a risk factor for developing various complications of diabetes.. Japan Registry of Clinical Trials identifier: jRCT#031190022.

Topics: Blood Glucose; Diabetes Mellitus, Type 2; Dipeptidyl-Peptidase IV Inhibitors; Dipeptidyl-Peptidases and Tripeptidyl-Peptidases; Drug Therapy, Combination; East Asian People; Glycated Hemoglobin; Humans; Hypoglycemic Agents; Metformin; Obesity; Sitagliptin Phosphate; Sodium; Sodium-Glucose Transporter 2 Inhibitors; Symporters; Treatment Outcome

Maternal obesity programs the offspring to metabolic diseases later in life; however, the mechanisms of programming are yet unclear, and no strategies exist for addressing its detrimental transgenerational effects. Obesity has been linked to dipeptidyl peptidase IV (DPPIV), an adipokine, and treatment of obese individuals with DPPIV inhibitors has been reported to prevent weight gain and improve metabolism. We hypothesized that DPPIV plays a role in maternal obesity-mediated programming. We measured plasma DPPIV activity in human maternal and cord blood samples from normal-weight and obese mothers at term. We found that maternal obesity increases maternal and cord blood plasma DPPIV activity but only in male offspring. Using two non-human primate models of maternal obesity, we confirmed the activation of DPPIV in the offspring of obese mothers. We then created a mouse model of maternal high-fat diet (HFD)-induced obesity, and found an early-life increase in plasma DPPIV activity in male offspring. Activation of DPPIV preceded the progression of obesity, glucose intolerance and insulin resistance in male offspring of HFD-fed mothers. We then administered sitagliptin, DPPIV inhibitor, to regular diet (RD)- and HFD-fed mothers, starting a week prior to breeding and continuing throughout pregnancy and lactation. We found that sitagliptin treatment of HFD-fed mothers delayed the progression of obesity and metabolic diseases in male offspring and had no effects on females. Our findings reveal that maternal obesity dysregulates plasma DPPIV activity in males and provide evidence that maternal inhibition of DPPIV has potential for addressing the transgenerational effects of maternal obesity.

Topics: Animals; Diet, High-Fat; Dipeptidyl Peptidase 4; Female; Humans; Male; Maternal Nutritional Physiological Phenomena; Metabolic Diseases; Mice; Obesity; Obesity, Maternal; Pregnancy; Sitagliptin Phosphate

Nonalcoholic fatty liver disease (NAFLD) is a common cause of clinical liver dysfunction and an important prepathological change of liver cirrhosis. Central obesity, type 2 diabetes mellitus, dyslipidemia, and metabolic syndrome are the major risk factors for NAFLD. Sitagliptin (Sig) is a novel hypoglycemic agent that improves blood glucose levels by increasing the level of active incretin. Sig has been shown to prevent the development of fatty livers in mice on a fructose-rich diet. The purpose of this study was to observe the efficacy of Sig on NAFLD in type 2 diabetic mice.. The diet-induced obesity mouse model was established, and the diabetic mice were screened by an intraperitoneal glucose tolerance trial. The mice were randomly divided into four groups for 8 weeks of intervention: high-fat diet (HFD) group, Sig group, metformin (Met) group, and Sig+Met group. After the intervention, the liver function indexes as well as the blood glucose and blood lipid levels of the mice were measured. In addition, the wet weight of the liver was measured; the pathological sections of the liver tissues were stained to observe the hepatocyte fatty degeneration, inflammation, necrosis, and fibrosis; and the hepatic histological injury was recorded as the NAFLD activity score (NAS).. Compared with the normal control group, the body weight, liver weight, blood glucose level, insulin resistance (IR), blood lipid level, and transaminase level of the mice in the HFD group were significantly increased, showing typical metabolic syndrome. After treatment with Sig and/or Met, the mice gained less weight, had lower levels of blood glucose, triglyceride (TG), low-density lipoprotein cholesterol (LDL-C), and transaminase, and had improved IR compared with the HFD group. The liver pathological NASs in the Sig group (P=0.01), Met group (P=0.028), and Sig+Met group (P<0.001) were lower than those in the HFD group (P<0.05), suggesting that the use of the two drugs alone or in combination can improve the state of liver inflammation. In terms of fibrosis, there was no fibrosis in the control group but there was significant fibrosis in the HFD group (P<0.001). There was no significant difference between the drug intervention groups and the HFD group, indicating that the drug therapy (Sig and/or Met) did not significantly improve the pre-existing fibrosis.. Our experiment proved that Sig can improve NAFLD, including improvement of the serum transaminase level, hepatic pathological inflammation level, and hepatocyte adiposis, suggesting that Sig may play a role by improving glucose and lipid metabolism, reducing the body weight and liver weight, improving insulin sensitivity, and inhibiting fatty liver inflammation. Sig may be a new direction for the treatment of patients with a nonalcoholic fatty liver and diabetes, delaying the progression of NAFLD.

Topics: Animals; Blood Glucose; Diabetes Mellitus, Experimental; Diabetes Mellitus, Type 2; Diet, High-Fat; Humans; Inflammation; Insulin Resistance; Liver Cirrhosis; Metabolic Syndrome; Metformin; Mice; Non-alcoholic Fatty Liver Disease; Obesity; Sitagliptin Phosphate; Transaminases

Obesity is accompanied by a chronic low-grade inflammation associated with endothelial dysfunction and vascular complications. Procalcitonin is a marker of inflammation, secreted by adipose tissue and elevated in obese subjects. We here investigated whether visceral or perivascular fat-derived procalcitonin is a target to improve obesity-induced endothelial dysfunction.. Procalcitonin expression was identified by Western blot. Murine endothelial cells were isolated using CD31-antibody-coated magnetic beads and reactive oxygen species and nitric oxide (NO) determined by H2DCF- or DAF-FM diacetate loading. Endothelium-dependent vasorelaxation was analyzed using pressure myography of murine arterioles. Calcitonin gene-related peptide (CGRP) was used to activate the calcitonin receptor-like receptor (CRLR)/RAMP1 complex and olcegepant or the dipeptidyl-peptidase 4 (DPP4) inhibitor sitagliptin to block procalcitonin signaling or activation.. In addition to visceral adipose tissue, procalcitonin was present in perivascular and epicardial tissue. In concentrations typical for obesity, procalcitonin doubled reactive oxygen species formation and decreased endothelial nitric oxide production in murine endothelial cells. Intravenous delivery of procalcitonin to mice in obesity-associated concentrations impaired endothelium-dependent vasorelaxation in a CRLR/RAMP1-dependent manner and antagonized CGRP-induced endothelial NO release in vitro. Use of CRLR/RAMP1-receptor antagonist olcegepant counteracted procalcitonin effects on vasodilation, nitric oxide production and reactive oxygen species formation. Similarly, blocking procalcitonin activation by the DPP4 inhibitor sitagliptin antagonized endothelial procalcitonin effects.. Procalcitonin, liberated either from visceral or perivascular adipose tissue, contributes to endothelial dysfunction by antagonizing CGRP signaling in obesity. Targeting hyperprocalcitonemia may be a means to preserve endothelial function and reduce comorbidity burden in obese subjects.

Topics: Animals; Calcitonin Gene-Related Peptide; Calcitonin Receptor-Like Protein; Dipeptidyl Peptidase 4; Dipeptidyl-Peptidase IV Inhibitors; Endothelial Cells; Endothelium, Vascular; Inflammation; Mice; Nitric Oxide; Obesity; Procalcitonin; Reactive Oxygen Species; Sitagliptin Phosphate; Vasodilation

Topics: Animals; Blood Glucose; Diet; Incretins; Mice; Mice, Obese; Niacin; Obesity; Palmitates; PPAR gamma; Sitagliptin Phosphate; Up-Regulation

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

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

Obesity is often associated with inflammation in adipose tissue (AT) with release of mediators of atherogenesis. We postulated that it would be feasible to collect sufficient abdominal AT to quantify changes in a broad array of adaptive and innate mononuclear white cells in obese non-diabetic adults in response to a dipeptidyl protease inhibitor (DPP4i), known to inhibit activation of immune white cells.. Adults 18-55 years-of-age were screened for abdominal obesity and insulin resistance or impaired glucose tolerance but without known inflammatory conditions. Twenty-one eligible participants consented for study and were randomized 3:1 to receive sitagliptin (DPP4i) at 100mg or matching placebo daily for 28 days. Abdominal AT collected by percutaneous biopsy and peripheral blood mononuclear cell fractions were evaluated before and after treatment; plasma was stored for batch testing.. Highly sensitive C-reactive protein, a global marker of inflammation, was not elevated in the study population. Innate lymphoid cells (ILC) type 3 (ILC-3) in abdominal AT decreased with active treatment compared with placebo (p = 0.04). Other immune white cells in AT and peripheral blood mononuclear cell (PBMC) fractions did not change with treatment compared to placebo (p>0.05); although ILC-2 declined in PBMCs (p = 0.007) in the sitagliptin treatment group. Two circulating biomarkers of atherogenesis, interferon-inducible protein-10 (IP-10) and sCD40L declined in plasma (p = 0.02 and p = 0.07, respectively) in the active treatment group, providing indirect validation of a net reduction in inflammation.. In this pilot study, two cell types of the innate lymphoid system, ILC-3 in AT and ILC-2 PBMCs declined during treatment and as did circulating biomarkers of atherogenesis. Changes in other immune cells were not demonstrable. The study showed that sufficient abdominal AT could be obtained to quantify white cells of both innate and adaptive immunity and to demonstrate changes during therapy with an immune inhibitor.. ClinicalTrials.gov identifier (NCT number): NCT02576.

Topics: Abdominal Fat; Adult; Biomarkers; Feasibility Studies; Female; Flow Cytometry; Humans; Immunity, Innate; Leukocytes, Mononuclear; Lymphocytes; Male; Middle Aged; Obesity; Sitagliptin Phosphate; Treatment Outcome

Chronopharmacology is the study of the varying responses of drugs to changes in biological timing and endogenous periodicities. The dipeptidyl peptidase-4 inhibitor sitagliptin is a globally prescribed anti-hyperglycemic drug. Although dipeptidyl peptidase-4 inhibitors are usually administered once, the specific intake time is generally not mentioned. Therefore, this study aimed at investigating the diurnal effects of sitagliptin-induced anti-hyperglycemia in high-fat diet (HFD)-induced obesity in mice. Five-week-old male C57BL/6J mice were fed normal (control) diet or HFD for 10 weeks. During the last 2 weeks, the mice were administered saline or sitagliptin (10 mg/kg, per os) in the light or dark phase, respectively. At the end of the experiment, the mice were euthanized after an 18 h fasting period, and plasma and tissue samples (liver, kidney, and epididymal white adipose tissues) were collected, or the oral glucose tolerance test was performed. Sitagliptin administration in the light phase significantly decreased plasma glucose levels, insulin levels, hepatic steatosis, and restored the glucose tolerance compared with the HFD group. In contrast, these parameters remained unchanged in the dark phase-treated mice. Our data therefore suggests that sitagliptin portrays definite chronopharmacology, which may provide valuable information on the importance of drug administration timing for maximum pharmacological effects.

Topics: Adipose Tissue; Animals; Blood Glucose; Diet, High-Fat; Disease Models, Animal; Drug Chronotherapy; Glucose; Hyperglycemia; Hypoglycemic Agents; Liver; Male; Mice, Inbred C57BL; Obesity; Organ Size; Sitagliptin Phosphate

Topics: Acetylcholine; Animals; Aorta, Thoracic; Autophagy; Diabetes Mellitus, Experimental; Endothelium, Vascular; Human Umbilical Vein Endothelial Cells; Humans; Hypoglycemic Agents; Male; Malondialdehyde; Mesenteric Arteries; Nitric Oxide Synthase Type III; Obesity; Peroxynitrous Acid; Rats; Rats, Zucker; Sitagliptin Phosphate; Superoxide Dismutase; Vasodilation

Obesity-induced metabolic disease involves functional integration among several organs via circulating factors, but little is known about crosstalk between liver and visceral adipose tissue (VAT). In obesity, VAT becomes populated with inflammatory adipose tissue macrophages (ATMs). In obese humans, there is a close correlation between adipose tissue inflammation and insulin resistance, and in obese mice, blocking systemic or ATM inflammation improves insulin sensitivity. However, processes that promote pathological adipose tissue inflammation in obesity are incompletely understood. Here we show that obesity in mice stimulates hepatocytes to synthesize and secrete dipeptidyl peptidase 4 (DPP4), which acts with plasma factor Xa to inflame ATMs. Silencing expression of DPP4 in hepatocytes suppresses inflammation of VAT and insulin resistance; however, a similar effect is not seen with the orally administered DPP4 inhibitor sitagliptin. Inflammation and insulin resistance are also suppressed by silencing expression of caveolin-1 or PAR2 in ATMs; these proteins mediate the actions of DPP4 and factor Xa, respectively. Thus, hepatocyte DPP4 promotes VAT inflammation and insulin resistance in obesity, and targeting this pathway may have metabolic benefits that are distinct from those observed with oral DPP4 inhibitors.

Topics: Administration, Oral; Animals; Caveolin 1; Dipeptidyl Peptidase 4; Factor Xa; Hepatocytes; Humans; Inflammation; Insulin Resistance; Intra-Abdominal Fat; Macrophages; Male; Mice; Mice, Obese; Obesity; Receptor, PAR-2; Sitagliptin Phosphate

Chronic overnutrition leads to cardiac dysfunction and insulin (INS) resistance. Dipeptidyl peptidase-4 (DPP-4) improves glucose metabolism and insulin sensitivity in both human and animal models. In this study, we explored whether DPP-4 inhibitor sitagliptin (SIT) is involved in the protection of cardiac function and. Six-week-old C57BL6/J mice were fed a high fat and fructose Western diet with DPP-4 inhibitor SIT for 12 weeks. Cardiac function was examined by echocardiography. Body weight, plasma glucose, and insulin concentrations were measured. The contents of total S6 kinase 1 (S6K1), phosphorylation of S6K1 activation, and INS docking proteins INS receptor substrates 1 and 2 (IRS-1, IRS-2) were assayed, and histology of heart tissue was performed.. This study revealed pleiotropic protective effects of DPP-4 inhibitor SIT on cardiac function, glycemia, and

Topics: Animals; Blood Glucose; Body Weight; Dipeptidyl-Peptidase IV Inhibitors; Echocardiography; Enzyme Activation; Female; Heart; Homeostasis; Insulin; Insulin Receptor Substrate Proteins; Insulin-Secreting Cells; Mice; Mice, Inbred C57BL; Obesity; Ribosomal Protein S6 Kinases, 90-kDa; Signal Transduction; Sitagliptin Phosphate

The purpose of the study is to identify potential mechanisms involved in the cardiac protective effects of sitagliptin in Zucker diabetic fatty (ZDF) rats.. Male non-diabetic lean Zucker rats (Lean) and ZDF rats treated with saline (ZDF) or sitagliptin (ZDF + sita) were used in this study. The blood pressure and lipid profiles were increased significantly in ZDF rats compared with Lean rats. ZDF + sitagliptin rats had decreased systolic blood pressure compared with ZDF rats. Sitagliptin treatment decreased total cholesterol (TC), triglycerides (TGs), low-density lipoprotein (LDL), and high-density lipoprotein (HDL) levels. Ejection fraction (EF) and fractional shortening (FS) were decreased in ZDF rats, which improved with sitagliptin from 59.8% ± 3.0 and 34.5% ± 3.1 to 66.9% ± 3.4 and 40.9% ± 4.2, respectively. Moreover, the nitroxidative stress level was increased while autophagy levels were decreased in ZDF rats, which was reversed by the administration of sitagliptin. Treatment with sitagliptin or FeTMPyP improved the autophagy level in high-glucose cultured H9c2 cells by increasing autolysosome numbers from 15 ± 4 to 21 ± 3 and 22 ± 3, respectively. We detected a positive correlation between DPP-4 activity and 3-nitrotyrosine levels (r = 0.3903; P < 0.01), a negative correlation between Beclin-1 levels and DPP-4 activity (r = - 0.3335; P < 0.01), and a negative correlation between 3-nitrotyrosine and Beclin-1 levels (r = - 0.3794; P < 0.01) in coronary heart disease patients.. Sitagliptin alleviates diabetes-induced cardiac injury by reducing nitroxidative stress and promoting autophagy. This study indicates a novel target pathway for the treatment of cardiovascular complications in type 2 diabetes mellitus.

Topics: Animals; Autophagy; Beclin-1; Blood Glucose; Cell Line; Diabetes Mellitus, Type 2; Diabetic Cardiomyopathies; Dipeptidyl Peptidase 4; Dipeptidyl-Peptidase IV Inhibitors; Disease Models, Animal; Humans; Lipids; Male; Myocytes, Cardiac; Nitrosative Stress; Obesity; Rats, Zucker; Sitagliptin Phosphate; Stroke Volume; Tyrosine; Ventricular Function, Left

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

The objective of the present study was to observe the effect of sitagliptin on obese patients with insulin treatment-induced diabetes mellitus.. A total of 120 obese patients with insulin treatment-induced diabetes mellitus were consecutively selected and divided into the control group (n=35), observation group 1 (n=40), and observation group 2 (n=45). The control group received different types or doses of insulin, observation group 1 received insulin combined with metformin, and observation group 2 received insulin combined with sitagliptin. The therapeutic effects were compared at the 6-month follow-up visit.. Body mass index (BMI) was lower in observation group 1 and observation group 2, and higher in the control group compared with before treatment; the occurrence of hypoglycemia in observation group 2 was lower than in the other two groups, and the differences were statistically significant (p<0.05). After treatment, the fasting insulin (FINS) and homeostatic model assessment insulin-resistance (HOMA-IR) in observation group 2 were significantly lower than in the other two groups (p<0.05). Adiponectin levels were increased and leptin and visfatin levels were decreased in observation group 2 after treatment, and the differences were statistically significant (p<0.05). The levels of fasting blood glucose, hemoglobin A1c, total cholesterol, triglyceride, and low-density lipoprotein in the three groups were not significantly different (p>0.05).. Sitagliptin can reduce BMI and the occurrence of hypoglycemia in obese patients with insulin treatment-induced diabetes mellitus, and the effect may be related to decreased HOMA-IR, decreased leptin and visfatin levels, and increased adiponectin levels.

Topics: Adiponectin; Adult; Aged; Blood Glucose; Body Mass Index; Diabetes Mellitus, Type 2; Fasting; Female; Glycated Hemoglobin; Humans; Hypoglycemia; Insulin; Insulin Resistance; Leptin; Male; Metformin; Middle Aged; Nicotinamide Phosphoribosyltransferase; Obesity; Sitagliptin Phosphate; Triglycerides

The aim of the study was to assess the effect of sitagliptin addition on the epicardial adipose tissue (EAT) thickness in subjects with type 2 diabetes mellitus inadequately controlled on metformin monotherapy. This was a 24-week interventional pilot study in 26 consecutive type 2 diabetic patients, 14 females and 12 males average age of 43.8 ± 9.0 years, with Hemoglobin A1c (HbA1c) ≥ 7% on metformin monotherapy. Subjects who met the inclusion criteria were added on sitagliptin and started on sitagliptin/metformin combination at the dosage of 50 mg/1000 mg twice daily. EAT and visceral and total body fat were measured, respectively, with echocardiography and bioelectrical impedance analysis at baseline and after 24 weeks of sitagliptin/metformin treatment in each subject. HbA1c and plasma lipids were also measured. EAT decreased significantly from 9.98 ± 2.63 to 8.10 ± 2.11 mm, p = 0.001, accounting for a percentage of reduction (∆%) of -15% after 24 weeks of sitagliptin addition, whereas total body fat percentage, visceral fat, and body mass index (BMI), decreased by 8, 12, and 7%, respectively (p = 0.001 for all). After 6 month, EAT ∆% was significantly correlated with ∆% of visceral fat (r = 0.456; p = 0.01), whereas no correlation with either BMI ∆% (r = 0.292; p = 0.147) or HbA1c ∆% was found. The addition of Sitagliptin produced a significant and rapid reduction of EAT, marker of organ-specific visceral fat, in overweight/obese individuals with type 2 diabetes inadequately controlled on metformin monotherapy. EAT as measured with ultrasound can serve as no invasive and accurate marker of visceral fat changes during pharmaceutical interventions targeting the fat.

Topics: Adipose Tissue; Adiposity; Adolescent; Adult; Aged; Body Composition; Diabetes Mellitus, Type 2; Drug Therapy, Combination; Electric Impedance; Female; Glycated Hemoglobin; Humans; Hypoglycemic Agents; Lipids; Male; Metformin; Middle Aged; Obesity; Pericardium; Pilot Projects; Sitagliptin Phosphate; Young Adult

Obese-insulin resistance and type 2 diabetes mellitus (T2DM) have become global health problems, and they are both associated with a higher risk of ischemic heart disease. Although reperfusion therapy is the treatment to increase blood supply to the ischemic myocardium, this intervention potentially causes cardiac tissue damage and instigates arrhythmias, processes known as reperfusion injury. Dipeptidyl peptidase 4 (DPP-4) inhibitors are glycemic control drugs commonly used in T2DM patients. Growing evidence from basic and clinical studies demonstrates that a DPP-4 inhibitor could exert cardioprotection and improve left ventricular function by reducing oxidative stress, apoptosis, and increasing reperfusion injury salvage kinase (RISK) activity. However, recent reports also showed potentially adverse cardiac events due to the use of a DPP-4 inhibitor. To investigate this disparity, future large clinical trials are essential in verifying whether DPP-4 inhibitors are beneficial beyond their glycemic control particularly for the ischemic heart in obese-insulin resistant subjects and T2DM patients.

Topics: Adamantane; Animals; Blood Glucose; Diabetes Mellitus, Type 2; Dipeptidyl-Peptidase IV Inhibitors; Humans; Hypoglycemic Agents; Insulin Resistance; Myocardial Ischemia; Nitriles; Obesity; Oxidative Stress; Pyrrolidines; Rats; Sitagliptin Phosphate; Ventricular Function, Left; Vildagliptin

Dipeptidyl peptidase 4 (DPP-4) cleaves a large number of chemokine and peptide hormones involved in the regulation of the immune system. Additionally, DPP-4 may also be involved in macrophage-mediated inflammation and insulin resistance. Thus, the current study investigated the effect of linagliptin, an inhibitor of DPP-4, on macrophage migration and polarization in white adipose tissue (WAT) and liver of high-fat diet-induced obese (DIO) mice. DPP-4(+) macrophages in lean and obese mice were quantified by fluorescence-activated cell sorting (FACS) analysis. DPP-4 was predominantly expressed in F4/80(+) macrophages in crown-like structures compared with adipocytes in WAT of DIO mice. FACS analysis also revealed that, compared with chow-fed mice, DIO mice exhibited a significant increase in DPP-4(+) expression in cells within adipose tissue macrophages (ATMs), particularly M1 ATMs. Linagliptin showed a greater DPP-4 inhibition and antioxidative capacity than sitagliptin and reduced M1-polarized macrophage migration while inducing an M2-dominant shift of macrophages within WAT and liver, thereby attenuating obesity-induced inflammation and insulin resistance. Loss of macrophage inflammatory protein-1α, a chemokine and DPP-4 substrate, in DIO mice abrogated M2 macrophage-polarizing and insulin-sensitizing effects of linagliptin. Therefore, the inhibition of DPP-4 by linagliptin reduced obesity-related insulin resistance and inflammation by regulating M1/M2 macrophage status.

Topics: Adipose Tissue; Animals; Cell Movement; Cells, Cultured; Dipeptidyl Peptidase 4; Dipeptidyl-Peptidase IV Inhibitors; Flow Cytometry; Inflammation; Insulin Resistance; Linagliptin; Macrophages; Male; Mice; Mice, Inbred C57BL; Obesity; Sitagliptin Phosphate

This study was designed to evaluate the efficacy of sitagliptin in Taiwanese diabetic subjects with different baseline BMI status.. This was a single-center, hospital-based, retrospective chart review in subjects (n=1874) with type 2 diabetes who received sitagliptin. Subjects were classified into subgroups depending upon their baseline BMI by Taiwan national weight classification: normal (BMI<24kg/m(2)) (n=504), overweight (BMI: 24-27kg/m(2)) (n=615), and obese (BMI⩾27kg/m(2)) (n=755). Changes in HbA1c and weight were evaluated over a 12month treatment period.. For all three groups, the HbA1c levels declined over the first three months by about 8%, and subsequently plateaued for the next nine months. Obese subjects were slower in reducing HbA1c compared with normal and overweight subjects (P<0.05), but at nine months the reduction was similar across groups. Mean body weight increased over the first nine months of sitagliptin therapy in subjects with normal BMI (57.12-58.30kg), but there was no change in mean body weight in the overweight group. After three months the obese groups had significantly greater loss in body weight compared with the normal group.. Baseline BMI status may influence the reduction of HbA1c levels within the first six months of sitagliptin therapy and affect weight change after three months. Being obese was associated with an initial lag in HbA1c reduction and greater weight loss compared with normal and overweight subjects.

Topics: Aged; Blood Glucose; Body Mass Index; Body Weight; Diabetes Mellitus, Type 2; Female; Glycated Hemoglobin; Humans; Hypoglycemic Agents; Male; Middle Aged; Obesity; Overweight; Retrospective Studies; Sitagliptin Phosphate; Taiwan

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

Proton pump inhibitors as adjunctive therapy would improve diabetes control and could enhance the hypoglycaemic activity of DPP-4 inhibitors. The aim of the study was to investigate the short-term effects of lansoprazole (LPZ), sitagliptin (SITA) and their combination therapy on glucose regulation and gut peptide secretion.. Glucose and gut peptide were determined and compared after short-term administration of LPZ or SITA, or in combination to mice with diet-induced obesity (DIO) and to healthy human subjects (n = 16) in a 75 g oral glucose tolerance test (OGTT) by a crossover design.. In DIO mice, LPZ significantly improve glucose metabolism, increase plasma C-peptide and insulin compared with vehicle treatment. Furthermore, the combination of LPZ and SITA improved glucose tolerance additively, with higher plasma insulin and C-peptide levels compared with SITA-treated mice. Similarly, in human in the OGTT, the combination showed significant improvement in glucose-lowering and insulin increase vs SITA-treated group. However, no significant differences in area under curve (AUC) of insulin, glucose and C-peptide between the LPZ-treated group and baseline, except that mean AUCgastrin was significantly increased by LPZ.. LPZ and SITA combination therapy appears to have complementary mechanisms of action and additive antidiabetic effect.

Topics: Adult; Animals; Area Under Curve; Blood Glucose; C-Peptide; Diet; Drug Synergism; Drug Therapy, Combination; Glucose; Glucose Tolerance Test; Humans; Hypoglycemic Agents; Insulin; Lansoprazole; Male; Mice; Mice, Inbred C57BL; Mice, Obese; Obesity; Pyrazines; Sitagliptin Phosphate; Triazoles

Long-term high-fat diet (HFD) consumption has been shown to cause insulin resistance, which is characterized by hyperinsulinaemia with metabolic inflexibility. Insulin resistance is associated with cardiac sympathovagal imbalance, cardiac dysfunction and cardiac mitochondrial dysfunction. Dipeptidyl peptidase-4 (DPP-4) inhibitors, vildagliptin and sitagliptin, are oral anti-diabetic drugs often prescribed in patients with cardiovascular disease. Therefore, in this study, we sought to determine the effects of vildagliptin and sitagliptin in a murine model of insulin resistance.. Male Wistar rats weighing 180-200 g, were fed either a normal diet (20% energy from fat) or a HFD (59% energy from fat) for 12 weeks. These rats were then divided into three subgroups to receive vildagliptin (3 mg·kg(-1)·day(-1)), sitagliptin (30 mg·kg(-1)·day(-1)) or vehicle for another 21 days. Metabolic parameters, oxidative stress, heart rate variability (HRV), cardiac function and cardiac mitochondrial function were determined.. Rats that received HFD developed insulin resistance characterized by increased body weight, plasma insulin, total cholesterol and oxidative stress levels along with a decreased high-density lipoprotein (HDL) level. Moreover, cardiac dysfunction, depressed HRV, cardiac mitochondrial dysfunction and cardiac mitochondrial morphology changes were observed in HFD rats. Both vildagliptin and sitagliptin decreased plasma insulin, total cholesterol and oxidative stress as well as increased HDL level. Furthermore, vildagliptin and sitagliptin attenuated cardiac dysfunction, prevented cardiac mitochondrial dysfunction and completely restored HRV.. Both vildagliptin and sitagliptin share similar efficacy in cardioprotection in obese insulin-resistant rats.

Topics: Adamantane; Animals; Blood Glucose; Blood Pressure; Body Weight; Cardiotonic Agents; Cholesterol; Diet, High-Fat; Dipeptidyl-Peptidase IV Inhibitors; Heart; Heart Rate; Insulin; Insulin Resistance; Male; Malondialdehyde; Membrane Potential, Mitochondrial; Mitochondria, Heart; Nitriles; Obesity; Oxidative Stress; Pyrazines; Pyrrolidines; Rats, Wistar; Reactive Oxygen Species; Sitagliptin Phosphate; Triazoles; Vildagliptin

Studies investigating the effects of dipeptidyl peptidase-4 inhibitors on hepatic steatosis are lacking. We aimed to determine the effects of sitagliptin on nonalcoholic fatty liver disease (NAFLD) in rats with diet-induced obesity.. A total of 24 adult female Sprague-Dawley rats, which were 24 weeks old and weighed 199-240 grams, were used. The rats were randomly separated into two groups. The control group (n=6) was fed with standard rat diet; the remaining rats (n=18) were fed with a high-fat diet (HFD) to induce NAFLD. After 12 weeks, rats that were fed with a HFD were randomly separated into two groups: (1) HFD-only group (n=8) was fed with a HFD for an additional 4 weeks, (2) HFD-sitagliptin group (n=10) received sitagliptin (3 mg/kg) for 4 weeks in addition to HFD. At the end of the study (16(th) week), blood samples were drawn from all rats to determine serum glucose, triglyceride, cholesterol, alanine aminotransferase (ALT), and plasma insulin levels. Insulin resistance was determined using the homeostasis model assessment of insulin resistance (HOMA-IR) index. Histopathologic evaluation of liver samples was undertaken.. The HFD-sitagliptin group had significantly lower serum glucose (140.8±18.8 vs. 224.7±20.6 mg/dL, P<0.001), plasma insulin (15.8±4.4 vs. 28.0±5.9 μIU/L, P<0.001), HOMA-IR index (4.9±1.8 vs. 15.9±2.3, P<0.001), serum triglycerides (199.0±108.7 vs. 468.0±370.7 mg/dL, P<0.001), and cholesterol (82.0±26.7 vs. 90.5±7.0, P<0.001) values compared to the HFD-only group. Hepatic steatosis was significantly less (mean score, 1 vs. 2; P<0.001) in the HFD-sitagliptin group compared to the HFD-only group, whereas there was no difference in hepatic inflammation (P=0.057), liver weight (P=0.068), and ALT levels (P=0.232).. Sitagliptin may improve hepatic steatosis by increasing insulin sensitivity and improving lipid profiles in rats.

Topics: Alanine Transaminase; Animals; Blood Glucose; Cholesterol; Diet, High-Fat; Dipeptidyl-Peptidase IV Inhibitors; Fatty Liver; Female; Insulin; Insulin Resistance; Liver; Non-alcoholic Fatty Liver Disease; Obesity; Pyrazines; Rats; Rats, Sprague-Dawley; Sitagliptin Phosphate; Triazoles; Triglycerides

Recent evidence has demonstrated that insulin resistance is related to the development of type 2 diabetes mellitus. Our previous study found that high-fat diet (HFD) consumption caused not only peripheral and brain insulin resistance but also brain mitochondrial dysfunction and cognitive impairment. Vildagliptin and sitagliptin, dipeptidyl-peptidase-4 inhibitors, are recently developed anti-diabetic drugs. However, the effects of both drugs on cognitive behaviors and brain mitochondrial function in HFD-induced insulin-resistant rats have not yet been investigated. Sixty male Wistar rats were divided into two groups to receive either normal diet or HFD for 12 weeks. Rats in each group were then further divided into three treatment groups to receive either vehicle, vildagliptin (3 mg/kg per day), or sitagliptin (30 mg/kg per day) for 21 days. The cognitive behaviors of the rats were tested using the Morris Water Maze test. Blood samples were collected to determine metabolic parameters and plasma oxidative stress levels. Upon completion of the study, the animals were killed and the brains were removed to investigate brain and hippocampal mitochondrial function as well as to determine oxidative stress levels. We demonstrated that both drugs significantly improved the metabolic parameters and decreased circulating and brain oxidative stress levels in HFD-induced insulin-resistant rats. In addition, both drugs completely prevented brain and hippocampal mitochondrial dysfunction and equally improved the learning behaviors impaired by the HFD. Our findings suggest that the inhibition of dipeptidyl-peptidase-4 enzymes with vildagliptin or sitagliptin in insulin-resistant rats not only increases peripheral insulin sensitivity but also decreases brain dysfunction.

Topics: Adamantane; Animals; Behavior, Animal; Brain; Cognition Disorders; Diabetes Mellitus, Type 2; Diet, High-Fat; Dipeptidyl-Peptidase IV Inhibitors; Hippocampus; Insulin Resistance; Male; Maze Learning; Memory; Memory Disorders; Mitochondria; Nitriles; Obesity; Oxidative Stress; Pyrazines; Pyrrolidines; Rats; Rats, Wistar; Sitagliptin Phosphate; Triazoles; Vildagliptin

Dipeptidyl peptidase (DPP)-4 is responsible for the degradation of several peptides that contain an alanine or proline at the penultimate position or position P1. DPP-4 inhibitors (DPP-4is) have protective effects against type-2 diabetes and several metabolic disorders.. In the present study, we examined the effects of des-fluoro-sitagliptin (DFS), a DDP-4i, on body adiposity and levels of peroxisome proliferator-activated receptor (PPAR)-α, PPAR-γ coactivator-1 (PGC-1), and uncoupling proteins (UCPs) in mice with diet-induced obesity.. Treatment with DFS dose-dependently decreased the weight of white adipose tissue and serum levels of glucose, compared with controls, without influencing food intake (P<0.05). Additionally, DFS treatment increased the levels of PPAR-α, PGC-1, and UCPs in brown adipose tissue (BAT), and of PPAR-α and UCP3 in skeletal muscle (P<0.05). Furthermore, the effects on BAT PGC-1 and muscle PPAR-α levels were attenuated by treatment with the glucagon-like peptide 1 (GLP-1) antagonist exendin (9-39). Interestingly, hypothalamic levels of proopiomelanocortin (POMC) were increased by DFS treatment and the effects of DFS on PPAR-α, PGC-1, and UCP levels were attenuated in melanocortin (MC)-4 receptor-deficient mice.. In conclusion, high-dose DFS appeared to regulate body adiposity and UCPs in mice with diet-induced obesity, at least partly through a GLP-1 and/or MC-4 pathway.

Topics: Adipose Tissue, Brown; Adipose Tissue, White; Animals; Dietary Fats; Dipeptidyl-Peptidase IV Inhibitors; Ion Channels; Male; Mice; Mice, Inbred C57BL; Mitochondrial Proteins; Obesity; PPAR gamma; Pyrazines; Sitagliptin Phosphate; Triazoles; Uncoupling Protein 1

Intentional weight loss, primarily by improving insulin resistance, is known to decrease the need for anti-diabetic medications. In this study, we assess the magnitude of weight loss that resulted in dose reductions or discontinuation of anti-diabetic medications in overweight or obese patients with type 2 diabetes (DM) undergoing weight loss treatment.. Case records of 50 overweight or obese patients with DM who successfully decreased dosage or discontinued diabetes medications after losing weight via attendance at two University-based, outpatient weight management centers were analyzed. Follow-up visits, weight reduction interventions, and decisions for dose reductions or discontinuation of medications were individualized to patient needs by the treating physician.. Mean starting BMI was 35 kg/m(2), mean age 53.4 years, and 58% were male. All 50 used at least one anti-diabetic medication (30 metformin, 39 sulfonylureas, 31 insulin, 21 sitagliptin) to manage blood sugar. Mean duration of follow-up was 30.2 months. Mean weight loss was 10.8 ± 4.1 kgs (11.1% of initial body weight ± 4.7%). 22/50 patients (44%) discontinued anti-diabetes medications (14 sulfonylureas [36%], 7 insulin [23%], 4 sitagliptin [19%]). The mean percentage weight loss achieved at the point of successful discontinuation of medication was 11.2% ± 3.5% (14% for sulphonylureas, 11% for insulin, and 7.1% for sitagliptin). Mean percentage weight loss of 5.6% ± 2.8% (5.1% for sulphonylureas, 4.3% for insulin, and 7.1% for sitagliptin) was required for initial dose reduction. For every 5% weight loss, predicted dose reductions were sulphonylureas, 39%; insulin, 42%; and any anti-diabetic medications, 49%.. Among overweight or obese patients with type 2 diabetes, intentional weight loss of 7-14% was typically required for full discontinuation of at least one anti-diabetic medication. Discontinuation of insulin was achieved at a mean weight reduction of 11% of initial body weight.

Topics: Adult; Aged; Body Mass Index; Cohort Studies; Diabetes Complications; Diabetes Mellitus, Type 2; Female; Humans; Hypoglycemic Agents; Insulin; Male; Middle Aged; Obesity; Overweight; Pyrazines; Regression Analysis; Retrospective Studies; Sitagliptin Phosphate; Sulfonylurea Compounds; Triazoles; Weight Loss

Dipeptidyl peptidase-IV (DPP-4) inhibitors are now used to improve postprandial glycemic control in type 2 diabetes. However, their effects on hepatic glucose production (HGP) in obesity are not clear. This study was designed to test the hypothesis that gluconeogenesis and HGP can be modulated by DPP-4 inhibitors in obesity.. Sprague Dawley male rats were divided into four groups, each on a different diet: general rat chow, n = 10 (G); G + sitagliptin, n = 10; high fat chow (obesity), n = 10 (55% fat calories, HFO); HFO + sitagliptin, n = 10. After 10 weeks, the rats were fasted overnight and glucose metabolism was determined using 3-(3)H-glucose and (14)C-glycerol as tracers.. Glycerol rate of appearance (P < 0.00001), plasma glycerol (P < 0.05) and free fatty acid (FFA) (P < 0.05) concentrations, and HGP (P < 0.05) were decreased in HFO + sitagliptin group compared with HFO group, but there was no significant difference between G and G + sitagliptin groups (P > 0.05). Gluconeogenesis in HFO group was five times of that in G rats (P < 0.01), but was significantly declined in HFO + sitagliptin group (P < 0.0001).. Gluconeogenesis and HGP were inhibited by sitagliptin in high fat-induced obese rats due to decreased glycerol availability, which was a result of reduced glycerol release from adipose tissues. The finding suggests that sitagliptin is potentially useful for controlling fasting glucose in obesity, thereby delaying or preventing the development of diabetes.

Topics: Animals; Dipeptidyl-Peptidase IV Inhibitors; Glucose; Liver; Male; Obesity; Pyrazines; Rats; Rats, Sprague-Dawley; Sitagliptin Phosphate; Triazoles

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

Patients with type 2 diabetes mellitus have an increased risk of fracture that can be further exacerbated by thiazolidinediones. A new class of antidiabetic agents control glucose through reduction of dipeptidyl peptidase-4 (DPP-4) activity; however the importance of DPP-4 for the control of bone quality has not been extensively characterized. We compared the effects of the thiazolidinedione pioglitazone and the DPP-4 inhibitor sitagliptin on bone quality in high-fat diet (HFD)-fed wild-type mice. In complementary studies, we examined bone quality in Dpp4(+/+) vs. Dpp4(-/-) mice. Pioglitazone produced yellow bones with greater bone marrow adiposity and significantly reduced vertebral bone mechanics in male, female, and ovariectomized (OVX) HFD fed female mice. Pioglitazone negatively affected vertebral volumetric bone mineral density, trabecular architecture, and mineral apposition rate in male mice. Sitagliptin treatment of HFD-fed wild-type mice significantly improved vertebral volumetric bone mineral density and trabecular architecture in female mice, but these improvements were lost in females after OVX. Genetic inactivation of Dpp4 did not produce a major bone phenotype in male and female Dpp4(-/-) mice; however, OVX Dpp4(-/-) mice exhibited significantly reduced femoral size and mechanics. These findings delineate the skeletal consequences of pharmacological and genetic reduction of DPP-4 activity and reveal significant differences in the effects of pioglitazone vs. sitagliptin vs. genetic Dpp4 inactivation on bone mechanics in mice.

Topics: Animals; Biomechanical Phenomena; Bone and Bones; Bone Density; Dipeptidyl Peptidase 4; Female; Hypoglycemic Agents; In Vitro Techniques; Male; Mice; Mice, Knockout; Obesity; Ovariectomy; Pioglitazone; PPAR gamma; Pyrazines; Sitagliptin Phosphate; Thiazolidinediones; Triazoles

We sought to evaluate the effects of telmisartan, sitagliptin, or their combination on pancreatic ultrastructural alterations in high-fat-fed C57BL/6 mice.. Three-month-old C57BL/6 mice were fed with standard chow (SC, 10% lipids) or high-fat diet (HF, 60% lipids) during 10 weeks to induce obesity and its comorbidities. After this period, treatment began (lasted 6 weeks), and the HF group was divided into 4 subgroups: untreated HF, HF plus telmisartan (5 mg/kg per day), HF plus sitagliptin (1.1 g/kg per day), and HF plus telmisartan plus sitagliptin. Drugs were mixed with diet. Biochemical analyses, radioimmunoassay, immunofluorescence, stereology, and transmission electron microscopy were performed to assess pancreatic remodeling.. Overweight, hyperinsulinemia, hyperglycemia, and dyslipidemia were found in the HF group, but these outcomes were controlled by the different treatments. Untreated HF animals also showed alterations concerning distribution of α/β cell followed by large and numerous lipid droplets within pancreas. Telmisartan and sitagliptin as monotherapy alleviated these findings, and a complete reversal of pancreatic steatosis was observed after treating with the combination of the 2 drugs.. AT1 receptor blockade, partial peroxisome proliferator-activated receptor gamma activation, and extended incretin action emerge as feasible strategies to control pancreatic steatosis and avoid progression of pancreatic diseases due to lipotoxicity.

Topics: Angiotensin II Type 1 Receptor Blockers; Animals; Benzimidazoles; Benzoates; Blood Glucose; Dietary Fats; Dipeptidyl-Peptidase IV Inhibitors; Drug Therapy, Combination; Insulin; Islets of Langerhans; Lipid Metabolism; Male; Mice; Mice, Inbred C57BL; Microscopy, Electron, Transmission; Obesity; Pancreas; Pancreas, Exocrine; Pyrazines; Sitagliptin Phosphate; Telmisartan; Triazoles

In this study, the effects of sitagliptin analogue (SITA) or pioglitazone (PIO) treatment on glucose homeostasis and Β-cell dynamics in animal models of type 2 diabetes--Akita and db/db mice were evaluated. After 4-6 weeks of treatment, both SITA and PIO were shown to lower non-fasting glucose levels and reduced glycemic excursion in the intraperitoneal glucose tolerance test. In addition, both drugs preserved normal islet structure and the proportion of Β-cells in the islets. Compared to the controls, SITA treatment induced a higher Β-cell proliferation rate in Akita mice and a lower rate of apoptosis in db/db mice, whereas PIO treatment induced a lower rate of apoptosis in db/db mice and reduced proliferation rates in Akita mice. In conclusion, both SITA and PIO appear to exert some beneficial effects on the islet structure in addition to glycemic control via different mechanisms that involve Β-cell dynamics in Akita and db/db mice. [BMB reports 2011; 44(11): 713-718].

Topics: Animals; Apoptosis; Blood Glucose; Body Weight; Cell Proliferation; Diabetes Mellitus, Experimental; Fasting; Glucose Tolerance Test; Homeostasis; Insulin-Secreting Cells; Ki-67 Antigen; Male; Mice; Mice, Inbred C57BL; Mice, Obese; Obesity; Organ Size; Pioglitazone; Pyrazines; Sitagliptin Phosphate; Thiazolidinediones; Triazoles

This study was performed to assess the effect of chronic low-dose sitagliptin, a dipeptidyl peptidase 4 inhibitor, on metabolic profile and on renal lesions aggravation in a rat model of type-2 diabetic nephropathy, the Zucker diabetic fatty (ZDF) rat. Diabetic and obese ZDF (fa/fa) rats and their controls ZDF (+/+) were treated for 6 weeks with vehicle (control) or sitagliptin (10 mg/kg/bw). Blood/serum glucose, HbA1c, insulin, Total-c, TGs, urea, and creatinine were assessed, as well as kidney glomerular and tubulointerstitial lesions (interstitial fibrosis/tubular atrophy), using a semiquantitative rating from 0 (absent/normal) to 3 (severe and extensive damage). Vascular lesions were scored from 0-2. Sitagliptin in the diabetic rats promoted an amelioration of glycemia, HbA1c, Total-c, and TGs, accompanied by a partial prevention of insulinopenia. Furthermore, together with urea increment prevention, renal lesions were ameliorated in the diabetic rats, including glomerular, tubulointerstitial, and vascular lesions, accompanied by reduced lipid peroxidation. In conclusion, chronic low-dose sitagliptin treatment was able to ameliorate diabetic nephropathy, which might represent a key step forward in the management of T2DM and this serious complication.

Topics: Animals; Blood Glucose; Body Weight; Diabetes Mellitus, Type 2; Diabetic Nephropathies; Dipeptidyl-Peptidase IV Inhibitors; Disease Models, Animal; Dose-Response Relationship, Drug; Insulin; Kidney Glomerulus; Lipid Peroxidation; Lipids; Male; Obesity; Pyrazines; Rats; Rats, Zucker; Sitagliptin Phosphate; Treatment Outcome; Triazoles

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

The aim of the present study was to evaluate the effects of monotherapies and combinations of drugs on insulin sensitivity, adipose tissue morphology, and pancreatic and hepatic remodelling in C57BL/6 mice fed on a very HF (high-fat) diet. Male C57BL/6 mice were fed on an HF (60% lipids) diet or SC (standard chow; 10% lipids) diet for 10 weeks, after which time the following drug treatments began: HF-T (HF diet treated with telmisartan; 5.2 mg x kg-1 of body weight x day-1), HF-S (HF diet treated with sitagliptin; 1.08 g x kg-1 of body weight.day-1), HF-M (HF diet treated with metformin; 310.0 mg x kg-1 of body weight x day-1), HF-TM (HF diet treated with telmisartan+metformin), HF-TS (HF diet treated with telmisartan+sitagliptin) and HF-SM (HF diet treated with sitagliptin+metformin). Treated groups also had free access to the HF diet, and treatments lasted for 6 weeks. Morphometry, stereological tools, immunostaining, ELISA, Western blot analysis and electron microscopy were used. The HF diet yielded an overweight phenotype, an increase in oral glucose intolerance, hyperinsulinaemia, hypertrophied islets and adipocytes, stage 2 steatosis (>33%), and reduced liver PPAR-alpha (peroxisome-proliferator-activated receptor-alpha) and GLUT-2 (glucose transporter-2) levels, concomitant with enhanced SREBP-1 (sterol-regulatory-element-binding protein-1) expression (P<0.0001). Conversely, all drug treatments resulted in significant weight loss, a reversal of insulin resistance, islet and adipocyte hypertrophy, and alleviated hepatic steatosis. Only the HF-T and HF-TS groups had body weights similar to the SC group at the end of the experiment, and the latter treatment reversed hepatic steatosis. Increased PPAR-alpha immunostaining in parallel with higher GLUT-2 and reduced SREBP-1 expression may explain the favourable hepatic outcomes. Restoration of adipocyte size was consistent with higher adiponectin levels and lower TNF-alpha (tumour necrosis factor-alpha) levels (P<0.0001) in the drug-treated groups. In conclusion, all of the drug treatments were effective in controlling the metabolic syndrome. The best results were achieved using telmisartan and sitagliptin as monotherapies or as a dual treatment, combining partial PPAR-gamma agonism and PPAR-alpha activation in the liver with extended incretin action.

Topics: Adipocytes; Angiotensin II Type 1 Receptor Blockers; Animals; Benzimidazoles; Benzoates; Dietary Fats; Dipeptidyl-Peptidase IV Inhibitors; Drug Evaluation, Preclinical; Drug Therapy, Combination; Energy Intake; Glucose Tolerance Test; Hypoglycemic Agents; Insulin Resistance; Liver; Male; Metabolic Syndrome; Metformin; Mice; Mice, Inbred C57BL; Obesity; Pancreas; Pyrazines; Sitagliptin Phosphate; Telmisartan; Triazoles

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