Comparison of the efficacy of sitagliptin and glimepiride dose-up in Japanese patients with type 2 diabetes poorly controlled by sitagliptin and glimepiride in combination

Rahim AA, Eliana F, Shrestha HK, Chaudhary S, Ngugi N, Mbanya JC, Aye TT, Latt TS, Akanov ZA, Syed AR, Tandon N, Unnikrishnan AG, Madhu SV, Jawa A, Chowdhury S, Bajaj S, Das AK. Consensus Recommendations on Sulfonylurea and Sulfonylurea Combinations in the Management of Type 2 Diabetes Mellitus - International Task Force

For decades, sulfonylureas (SUs) have been important drugs in the antidiabetic therapeutic armamentarium. They have been used as monotherapy as well as combination therapy. Focus on newer drugs and concerns about the risk of severe hypoglycemia and weight gain with some SUs have led to discussion on their safety and utility. It has to be borne in mind that the adverse events associated with SUs should not be ascribed to the whole class, as many modern SUs, such as glimepiride and gliclazide modified release, are associated with better safety profiles. Furthermore, individualization of treatment, using SUs in combination with other drugs, backed with careful monitoring and patient education, ensures maximum benefits with minimal side effects. The current guidelines, developed by experts from Africa, Asia, and the Middle East, promote the safe and smart use of SUs in combination with other glucose-lowering drugs.

The efficacy and safety of adding either vildagliptin or glimepiride to ongoing metformin therapy in patients with type 2 diabetes mellitus

OBJECTIVE

To compare the effects of either vildagliptin or glimepiride on glycemic variability, oxidative stress, and endothelial parameters in patients with type 2 diabetes mellitus (T2DM) inadequately controlled with metformin alone.

METHODS

In this randomized, open-label, parallel study, 34 patients with T2DM being treated with metformin having an HbA1c of 7.0-10.0% were allocated into either the vildagliptin or glimepiride group. A mixed-meal tolerance test and 72-hour continuous glucose monitoring were conducted, and urinary 8-iso-prostaglandinF_2α (PGF_2α) and endothelial-dependent flow-mediated dilatation (FMD) were evaluated at baseline and after 12 weeks of treatment.

RESULTS

Similar significant improvements in HbA1c level were shown in both vildagliptin (-0.8%) and glimepiride (-0.9%) groups after treatment (Ps<0.001). The mean amplitude of glycemic excursions (MAGE) and the mean of daily differences (MODD) were significantly decreased by vildagliptin (P = 0.044 and P = 0.031, respectively) but not by glimepiride. Glimepiride was significantly associated with a higher incidence of hypoglycemia than vildagliptin (P = 0.005). There were no significant differences in urinary 8-iso-PGF_2α or FMD between the two groups.

CONCLUSIONS

Vildagliptin effectively improved glucose level with a significantly greater reduction in glycemic variability and hypoglycemia than glimepiride in patients with T2DM ongoing metformin therapy. The two drugs showed no significant differences in urinary 8-iso-PGF_2α and FMD.

TRIAL REGISTRATION

NCT01404676.

A systematic literature review on the efficacy-effectiveness gap: comparison of randomized controlled trials and observational studies of glucose-lowering drugs

Aim

To identify a potential efficacy–effectiveness gap and possible explanations (drivers of effectiveness) for differences between results of randomized controlled trials (RCTs) and observational studies investigating glucose-lowering drugs.

Methods

A systematic literature review was conducted in English language articles published between 1 January, 2000 and 31 January, 2015 describing either RCTs or observational studies comparing glucagon-like peptide-1 analogs (GLP-1) with insulin or comparing dipeptidyl peptidase-4 inhibitors (DPP-4i) with sulfonylurea, all with change in glycated hemoglobin (HbA1c) as outcome. Medline, Embase, Current Content, and Biosis were searched. Information on effect estimates, baseline characteristics of the study population, publication year, study duration, and number of patients, and for observational studies, characteristics related to confounding adjustment and selection- and information bias were extracted.

Results

From 312 hits, 11 RCTs and 7 observational studies comparing GLP-1 with insulin, and from 474 hits, 16 RCTs and 4 observational studies comparing DPP-4i with sulfonylurea were finally included. No differences were observed in baseline characteristics of the study populations (age, sex, body mass index, time since diagnosis of type 2 diabetes mellitus, and HbA1c) or effect sizes across study designs. Mean effect sizes ranged from −0.43 to 0.91 and from −0.80 to 1.13 in RCTs and observational studies, respectively, comparing GLP-1 with insulin, and from −0.13 to 2.70 and −0.20 to 0.30 in RCTs and observational studies, respectively, comparing DPP-4i and sulfonylurea. Generally, the identified observational studies held potential flaws with regard to confounding adjustment and selection- and information bias.

Conclusions

Neither potential drivers of effectiveness nor an efficacy–effectiveness gap were identified. However, the limited number of studies and potential problems with confounding adjustment, selection- and information bias in the observational studies, may have hidden a true efficacy-effectiveness gap.

Impact of dipeptidyl peptidase-4 inhibitors on serum adiponectin: a meta-analysis

BACKGROUND

Adiponectin, an adipose-specific protein, is negatively correlated with pro-atherogenic low-density lipoprotein cholesterol (LDL-C) and other cardiovascular risk factors such as insulin resistance. Therefore, low levels of adiponectin are associated with a higher risk for diabetes and cardiovascular disease. Dipeptidyl peptidase-4 inhibitors (DPP4i) have been used for the treatment of type 2 diabetes mellitus (T2DM) as reversible inhibitors through interacting with DPP4 substrate and increase serum incretins such as glucagon-like peptide-1 (GLP-1). The present study aimed to evaluate the effect of DPP4i on serum adiponectin in T2DM patients.

METHODS

The PubMed, Embase, and Cochrane library databases were searched from inception to February 2016. Randomized controlled trials, evaluating the DPP4i (sitagliptin and vildagliptin) versus comparator (placebo or active-comparison), in T2DM patients with duration of ≥ 12 weeks, were identified. Weighted differences in means of adiponectin levels were calculated by using a fixed or random-effects model.

RESULTS

Ten randomized controlled trials, including 1,495 subjects, were identified. Compared with placebo, DPP4i (sitagliptin and vildagliptin) treatment significantly elevated adiponectin levels by 0.74 μg/mL (95% confidence interval [CI], 0.45 to 1.03) relative to that using an active-comparison by 0.00 μg/mL (95% CI, -0.57 to 0.56). Compared with active-comparison, vildagliptin treatment increased adiponectin levels by 0.32 μg/mL (95% CI, -0.01 to 0.65), whereas sitagliptin treatment decreased adiponectin levels by -0.24 μg/mL (95% CI, -1.07 to 0.58). Trials examining effects of other DPP4i were not found.

CONCLUSIONS

Sitagliptin and vildagliptin increased serum adiponectin levels and had no stronger effect than traditional oral antidiabetic drugs. Further trials with larger sample size are needed to confirm the results and investigate the association between serum adiponectin levels and treatment of other DPP-4 inhibitors.

TRIAL REGISTRATION

Registration No in PROSPERO: CRD42016037399 .

Efficacy, Safety and Treatment Satisfaction of Glimepiride vs Sitagliptin in Combination with Metformin in Type 2 Diabetes Mellitus

INTRODUCTION

Metformin is a preferred drug for starting treatment in type 2 diabetes mellitus. But, eventually most of the patients need additional drug to control blood sugar level. The choice of drug depends upon several factors including patient specific criteria, economical factors and treatment satisfaction.

AIM

The aim of the present study is to investigate the effects of adding sitagliptin or glimepiride on efficacy, safety and treatment satisfaction in patients with type 2 diabetes mellitus.

MATERIALS AND METHODS

It was a retrospective observational study on 50 patients each in sitagliptin and glimepiride group, who are receiving treatment for at least 12 weeks and are stable on respective treatment regimen. Glycated haemoglobin (HBA1c) was the primary measure of efficacy. Safety was assessed by checking weight gain/loss, hypoglycaemia episodes and other laboratory investigations. Patient satisfaction was assessed by Diabetes Treatment Satisfaction Questionnaire.

RESULTS

The HbA1c level after 12-24 weeks of treatment was not found to be significant compared to each other or from baseline. Compared to baseline fasting plasma glucose & postprandial plasma glucose were lower in glimepiride group. Sitagliptin was associated with less episodes of hypoglycaemia. Weight gain was associated with glimepiride but it was non-significant (p=0.08). Overall treatment satisfaction score were better for sitagliptin but were not statistically significant.

CONCLUSION

The efficacy of sitagliptin was comparable. Sitagliptin had superior adverse effect profile with less chances of hypoglycaemia and weight gain. Questionnaire scores were higher for sitagliptin indicating better treatment satisfaction compared to glimepiride.

Comparison of the efficacy of sitagliptin and glimepiride dose-up in Japanese patients with type 2 diabetes poorly controlled by sitagliptin and glimepiride in combination

Aims/Introduction

The goal of the study was to examine the effects of sitagliptin dose‐up or glimepiride dose‐up in Japanese patients with type 2 diabetes who were controlled inadequately by sitagliptin and glimepiride in combination.

Materials and Methods

A multicenter, prospective, randomized, open‐label study was carried out in 50 patients with type 2 diabetes treated with sitagliptin and low‐dose glimepiride. The patients were randomly assigned to receive the addition of 50 mg/day sitagliptin or 0.5 mg/day glimepiride. The primary end‐point was the percentage change in glycated hemoglobin (HbA1c).

Results

During a follow‐up period, the difference in the percentage changes in HbA1c between the two groups was not significant (P = 0.13). However, HbA1c was significantly decreased by glimepiride dose‐up (P < 0.01 vs baseline), but not by sitagliptin dose‐up (P = 0.74). Univariate linear regression analyses showed that the percentage change in HbA1c was significantly associated with the serum level of arachidonic acid (AA) in both groups.

Conclusions

There was no significant difference in the HbA1c‐lowering effects between the two groups. However, a significant HbA1c‐lowering effect from baseline of glimepiride dose‐up was found, and the AA level showed a negative correlation with the decrease in HbA1c in the sitagliptin dose‐up group, but a positive correlation in the glimepiride dose‐up group. These findings suggest that the AA level is associated with HbA1c reduction in response to dose‐up with these drugs in patients with type 2 diabetes in a combination therapy with sitagliptin and glimepiride. This trial was registered with UMIN (no. 000009544).