Effect of sitagliptin monotherapy on serum total ghrelin levels in people with type 2 diabetes

Effects of sitagliptin on serum lipid levels in patients with type 2 diabetes: a systematic review and meta-analysis

AIM

Lipid abnormalities often occur in patients with diabetes mellitus and the coexistence of diabetes mellitus and dyslipidaemia will increase the risk of cardiovascular diseases. However, the specific effects of sitagliptin on lipid control remain elusive in diabetic patients. The aim of this meta-analysis is to investigate the effects of sitagliptin alone or with other antidiabetic agents on serum lipid control.

METHODS

PubMed, Cochrane Library, Embase and the ClinicalTrials.gov website were systematically searched from 2006 (the first year that sitagliptin entered market) to 16 January 2021. Eligible studies were randomized clinical trials (RCTs) of sitagliptin including outcomes of serum total cholesterol (TC), triglycerides, high-density lipoprotein cholesterol (HDL-C) or low-density lipoprotein cholesterol (LDL-C).

RESULTS

A total of 14 RCTs with 2654 patients were identified. Treatment with sitagliptin alone or in combination with other antidiabetic agents significantly reduced serum TC [mean difference (MD) = -5.52 95% confidence interval (95% CI), -7.88 to -3.15; P < 0.00001] and LDL-C (MD = -0.07; 95% CI, -0.14 to 0.00; P < 0.00001) in patients with type 2 diabetes. No statistical significances were found in serum triglycerides (MD = 1.53; 95% CI, -8.22 to 11.28; P = 0.76) or HDL-C (MD = 0.65; 95% CI, -1.59 to 0.29; P = 0.18). Subgroup analyses suggest that sitagliptin can significantly decrease serum LDL-C, TC and triglyceride levels compared with placebo alone, and no statistical significance was found in comparison with the serum HDLC levels.

CONCLUSION

Sitagliptin alone or in combination with other antidiabetic agents significantly reduces serum TC and LDL-C in patients with type 2 diabetes mellitus, while no significant difference was observed in serum triglycerides or HDL-C.

Effects of Sitagliptin as Monotherapy and Add-On to Metformin on Weight Loss among Overweight and Obese Patients with Type 2 Diabetes: A Systematic Review and Meta-Analysis

BACKGROUND

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.

METHODS

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.

RESULTS

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.

CONCLUSION

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.

Random-effects meta-analysis of combined outcomes based on reconstructions of individual patient data

Meta-analyses of clinical trials typically focus on one outcome at a time. However, treatment decision-making depends on an overall assessment of outcomes balancing benefit in various domains and potential risks. This calls for meta-analysis methods for combined outcomes that encompass information from different domains. When individual patient data (IPD) are available from all studies, combined outcomes can be calculated for each individual and standard meta-analysis methods would apply. However, IPD are usually difficult to obtain. We propose a method to estimate the overall treatment effect for combined outcomes based on first reconstructing pseudo IPD from available summary statistics and then pooling estimates from multiple reconstructed datasets. We focus on combined outcomes constructed from two continuous original outcomes. The reconstruction step requires the specification of the joint distribution of these two original outcomes, including the correlation which is often unknown. For outcomes that are combined in a linear fashion, misspecifications of this correlation affect efficiency, but not consistency, of the resulting treatment effect estimator. For other combined outcomes, an accurate estimate of the correlation is necessary to ensure the consistency of treatment effect estimates. To this end, we propose several ways to estimate this correlation under different data availability scenarios. We evaluate the performance of the proposed methods through simulation studies and apply these to two examples: (a) a meta-analysis of dipeptidyl peptidase-4 inhibitors vs control on treating type 2 diabetes; and (b) a meta-analysis of positive airway pressure therapy vs control on lowering blood pressure among patients with obstructive sleep apnea.

Factors involved in decreasing the therapeutic effect of sitagliptin: a subanalysis of the JAMP study

Objective

As a subanalysis of the Januvia Multicenter Prospective Trial in Type 2 Diabetes (JAMP study), we examined factors that decreased blood glucose control effect of sitagliptin after 3 months and patients requiring an addition or increase of diabetes treatment.

Methods

We selected patients in whom glycated hemoglobin (HbA1c) levels decreased by month 3 after initiation of sitagliptin treatment and conducted two analyses: (1) in patients who did not change drugs until month 12, we compared changes in HbA1c levels between concomitant drugs and examined factors that decreased blood glucose control effect of sitagliptin; (2) compared changes in HbA1c levels and backgrounds between patients who did and did not require an addition to or increased dose of the antidiabetic agent.

Results

Four hundred and ninety-eight patients were chosen. In 369 patients without drug change until month 12, changes in HbA1c levels during months 3-12 were not significantly different among concomitant drugs; factors causing rebound HbA1c were smoking and weight gain. Patient characteristics were compared between those who did and did not require an additional drug or a dose increase (n = 114) (n = 384). Drug changes were associated with longer disease duration, younger age, higher rate of smoking, and higher degree of insulin resistance but not with concomitantly administered drugs.

Conclusion

Smoking and weight gain were factors that decreased the effect of sitagliptin on reducing blood glucose levels. Differences in concomitant drugs did not affect sitagliptin's effects on glycemic control. A dose increase or the addition of the antidiabetic drug was not associated with concomitant drugs.

Teneligliptin, a Chemotype Prolyl-Thiazolidine-Based Novel Dipeptidyl Peptidase-4 Inhibitor with Insulin Sensitizing Properties

BACKGROUND AND OBJECTIVES

Teneligliptin, a chemotype prolyl-thiazolidine-based novel dipeptidyl peptidase (DPP)-4 inhibitor, was preliminarily shown to reduce insulin resistance in patients with type 2 diabetes mellitus (T2DM). The objective of this study is to further investigate the insulin sensitising properties of teneligliptin in comparison to those of sitagliptin.

METHODS

Treatment-naïve subjects with T2DM were administered 20 mg/day teneligliptin monotherapy (n = 45). As a comparator, 25-50 mg/day sitagliptin monotherapy was performed in a non-randomized manner (n = 71). No other drugs were administered. At 3 months, levels of diabetic parameters were compared with those at baseline.

RESULTS

At 3 months, while similar reductions of glycated hemoglobin (HbA1c) levels were observed with these two drugs, indexes for insulin sensitivity [homeostasis model assessment (HOMA)-R and 20/(C-peptide × fasting blood glucose (FBG)) levels] ameliorated only with teneligliptin. Then, the subjects were divided into two groups representing distinct degrees of insulin resistance; high HOMA-R (≥4) and low HOMA-R (<2) groups. With teneligliptin, similar decreases of HbA1c levels were observed in high (9.85-7.66 %, p < 0.0005) and low (10.12-8.51 %, p < 0.01) HOMA-R groups. HOMA-R (-32.6 %, p < 0.05) and non-high density lipoprotein cholesterol (non-HDL-C, -6 %, p < 0.05) levels significantly decreased and 20/(C-peptide × FBG) levels significantly increased (53 %, p < 0.001) in high HOMA-R group. HOMA-B levels increased in both groups with significant inter-group differences (+101.7 % in low HOMA-R group vs. +55.4 % in high HOMA-R group). Group 2. With sitagliptin, similar decreases of HbA1c levels were observed from those of teneligliptin in either high or low HOMA-R group, but no changes of HOMA-R, non-HDL-C or 20/(C-peptide × FBG) levels were noted. Increases of HOMA-B levels with sitagliptin were comparable to those with teneligliptin in either high or low HOMA-R group.

CONCLUSIONS

These results indicate that: (i) teneligliptin ameliorates insulin sensitivity and non-HDL-C levels in subjects with high degrees of insulin resistance. This is not the case with sitagliptin, though similar glycemic efficacies were observed. (ii) glycemic efficacy of teneligliptin may be determined by the balance of its capacity in modulating insulin resistance and beta-cell function depending on the degrees of baseline insulin resistance.

Exenatide Treatment Causes Suppression of Serum Ghrelin Levels following Mixed Meal Test in Obese Diabetic Women

AIM

To investigate the effect of exenatide treatment on serum ghrelin levels in obese female patients with type 2 diabetes mellitus.

METHODS

Fourteen female patients with type 2 diabetes mellitus being treated with metformin and exenatide were enrolled. A mixed meal test was applied to the patients while continuing with their daily medications. Blood samples were taken before and at 60, 120, and 180 minutes following mixed meal test to measure serum total ghrelin, glucose, and insulin levels. The following week, exenatide treatment of the patients was paused for 24 hours and the same experimental procedures were repeated.

RESULTS

Serum ghrelin levels were suppressed significantly at 180 minutes with exenatide treatment compared with baseline (294.4 ± 57.5 versus 234.5 ± 59.4 pg/mL) (p < 0.001). Serum ghrelin levels at 180 minutes were statistically different when percentage change in serum ghrelin levels after mixed meal tests with and without exenatide usage were compared (p = 0.001). Estimated total area under the curve values for serum ghrelin concentrations was also significantly lower with exenatide compared with omitted treatment (p = 0.035).

CONCLUSION

These results suggest that the effect of exenatide on weight loss may be related with the suppression of serum ghrelin levels, which is an orexigenic peptide.

Effects of Sitagliptin on Lipid Profiles in Patients With Type 2 Diabetes Mellitus: A Meta-analysis of Randomized Clinical Trials

Sitagliptin has been reported to improve lipid profiles, but findings from these studies are conflicting. We conducted this meta-analysis to evaluate the effects of sitagliptin on serum lipids in patients with type 2 diabetes mellitus.We made a comprehensive literature search in PubMed, EMBASE, Cochrane Library, China National Knowledge Infrastructure, Wanfang, and VIP database until June 2015. Eligible studies were randomized clinical trials (RCTs) that investigated the effect of sitagliptin on serum triglycerides (TGs), total cholesterol (TC), low-density lipoprotein cholesterol (LDL-C), or high-density lipoprotein cholesterol (HDL-C).Eleven RCTs with 2338 patients were identified. Compared with controls, sitagliptin alone or in combination significantly improved serum TG (weighted mean difference [WMD] -0.24 mmol/L; 95% confidence interval [CI] -0.40 to -0.09; P = 0.002) and HDL-C (WMD 0.05 mmol/L; 95% CI 0.02-0.07; P < 0.001).However, no statistical significances were observed in LDL-C (WMD -0.07 mmol/L; 95% CI -0.22 to 0.08; P = 0.337) and TC (WMD -0.14; 95% CI -0.33 to 0.06; P = 0.177). Subgroup analyses revealed that sitagliptin alone achieved greater improvement in serum TG, TC, and HDL-C levels.These findings suggested that sitagliptin alone or in combination significantly improved serum TG and HDL-C levels in patients with type 2 diabetes mellitus.

Effects of Miglitol, Acarbose, and Sitagliptin on Plasma Insulin and Gut Peptides in Type 2 Diabetes Mellitus: A Crossover Study

INTRODUCTION

Both dipeptidyl peptidase-4 inhibitors and α-glucosidase inhibitors (α-GI) have been reported to change the incretin and insulin secretion. To examine the effects of acarbose, miglitol, and sitagliptin on glucose metabolism and secretion of gut peptides, we conducted a crossover study in patients with type 2 diabetes mellitus (T2DM).

METHODS

Eleven Japanese patients with T2DM underwent four meal tolerance tests with single administration of acarbose, miglitol, sitagliptin, or nothing. Fasting and postprandial plasma levels of glucose, insulin, glucagon, active glucagon-like peptide-1 (GLP-1), glucose-dependent insulinotropic polypeptide (GIP), ghrelin, and des-acyl ghrelin were measured.

RESULTS

Early-phase insulin secretion was reduced following acarbose and miglitol, and the areas under the curve (AUC) of insulin at 180 min following acarbose and miglitol were significantly lower than sitagliptin. AUC of plasma glucose at 180 min after acarbose, miglitol, and sitagliptin tended to be lower than in controls, and plasma glucose levels at 30-60 min following miglitol were significantly lower than in controls. Plasma glucagon, ghrelin, and des-acyl ghrelin levels did not differ among the four conditions. Postprandial plasma active GLP-1 levels and AUC of GLP-1 increased significantly in both the sitagliptin and miglitol groups compared to control. Postprandial plasma total GIP levels increased following sitagliptin but decreased after acarbose and miglitol. Changes in incretin levels tended to be greater with miglitol than acarbose.

CONCLUSION

These results showed that sitagliptin and α-GIs, miglitol more so than acarbose, improved hyperglycemia in patients with T2DM after single administration, and had different effects on insulin and incretin secretion.

TRIAL REGISTRATION

UMIN-CTR number, UMIN000009981.

Effects of miglitol, vildagliptin, or their combination on serum insulin and peptide YY levels and plasma glucose, cholecystokinin, ghrelin, and obestatin levels

We previously reported that combination therapy with an α-glucosidase inhibitor (αGI) and a dipeptidyl peptidase-4 (DPP-4) inhibitor increased active glucagon-like peptide-1 (GLP-1) levels and decreased total glucose-dependent insulinotropic polypeptide (GIP) levels, compared with monotherapy, in non-diabetic men. However, the peptide YY (PYY), cholecystokinin (CCK), ghrelin, and obestatin levels in patients receiving a combination of αGIs and DPP-4 inhibitors have not been previously reported. We evaluated the effect of miglitol, vildagliptin, or their combination on these parameters. Miglitol and/or vildagliptin were administered according to four different intake schedules in eleven non-diabetic men (C: no drug, M: miglitol; V: vildagliptin, M+V: miglitol+vildagliptin). Blood samples were collected at 0, 30, 60, and 120 min after the start of breakfast. The plasma glucose, serum insulin, serum total PYY (PYY1-36 and PYY3-36), plasma CCK, plasma active ghrelin, and plasma obestatin levels were measured. The area under the curve (AUC) of the serum total PYY level in the M group was significantly greater than that in the C group, and the AUC of the serum total PYY level in the M+V group was significantly lower than that in the M group. The combination therapy did not change the AUC of the plasma CCK, plasma active ghrelin, plasma obestatin, and ghrelin/obestatin levels, compared with the control. The results of our study suggested that combination therapy with miglitol and vildagliptin had no effect on appetite regulation hormones, such as total PYY, CCK, active ghrelin, and obestatin, compared with the levels in the control group.

Effects of 6-month sitagliptin treatment on glucose and lipid metabolism, blood pressure, body weight and renal function in type 2 diabetic patients: a chart-based analysis

Background

Sitagliptin is one of the dipeptidyl peptidase-4 (DPP-4) inhibitors which prevent the inactivation of incretins, increasing the endogenous active incretin levels. Incretins stimulate insulin secretion from pancreatic β-cells and inhibit glucagon secretion from pancreatic α-cells, which is favorable for the treatment of diabetes. Sitagliptin is released on December, 2009, in Japan. We retrospectively studied effects of 6-month-treatment with sitagliptin on glucose and lipid metabolism, blood pressure, body weight and renal function in patients with type 2 diabetes by a chart-based analysis.

Methods

We retrospectively studied 220 type 2 diabetic patients who have taken sitagliptin for 6 months by a chart-based analysis. Subjects studied include patients treated with sitagliptin monotherapy, sitagliptin add-on therapy, and switching from glinide to sitagliptin. We selected patients who have both data before and after 6-month sitagliptin treatment and compared the data before the sitagliptin treatment with the data at 6 month after the sitagliptin treatment started. Body weight, blood pressure, plasma glucose, hemoglobin A1c (HbA1c), serum lipids, and estimated glomerular filtration rate in type 2 diabetic patients were measured almost at the same time points before and after 6-month-treatment with sitagliptin.

Results

Body weight was significantly reduced after 6-month sitagliptin treatment by 0.8 kg. HbA1c levels were also significantly decreased after the sitagliptin treatment by 0.6%. We found a significant and negative correlation between change in body weight and body mass index at baseline. We also observed a significant and negative correlation between change in HbA1c and HbA1c levels at baseline. The number of patients who showed the absence of urinary glucose was significantly increased after the sitagliptin treatment.

Effects of 6-month sitagliptin treatment on glucose and lipid metabolism, blood pressure, body weight and renal function in type 2 diabetic patients: a chart-based analysis

BACKGROUND

Sitagliptin is one of the dipeptidyl peptidase-4 (DPP-4) inhibitors which prevent the inactivation of incretins, increasing the endogenous active incretin levels. Incretins stimulate insulin secretion from pancreatic β-cells and inhibit glucagon secretion from pancreatic α-cells, which is favorable for the treatment of diabetes. Sitagliptin is released on December, 2009, in Japan. We retrospectively studied effects of 6-month-treatment with sitagliptin on glucose and lipid metabolism, blood pressure, body weight and renal function in patients with type 2 diabetes by a chart-based analysis.

METHODS

We retrospectively studied 220 type 2 diabetic patients who have taken sitagliptin for 6 months by a chart-based analysis. Subjects studied include patients treated with sitagliptin monotherapy, sitagliptin add-on therapy, and switching from glinide to sitagliptin. We selected patients who have both data before and after 6-month sitagliptin treatment and compared the data before the sitagliptin treatment with the data at 6 month after the sitagliptin treatment started. Body weight, blood pressure, plasma glucose, hemoglobin A1c (HbA1c), serum lipids, and estimated glomerular filtration rate in type 2 diabetic patients were measured almost at the same time points before and after 6-month-treatment with sitagliptin.

RESULTS

Body weight was significantly reduced after 6-month sitagliptin treatment by 0.8 kg. HbA1c levels were also significantly decreased after the sitagliptin treatment by 0.6%. We found a significant and negative correlation between change in body weight and body mass index at baseline. We also observed a significant and negative correlation between change in HbA1c and HbA1c levels at baseline. The number of patients who showed the absence of urinary glucose was significantly increased after the sitagliptin treatment.