DPP-4 Inhibitor Treatment in Chinese Type 2 Diabetes Patients: A Meta-Analysis

Pathophysiology, phenotypes and management of type 2 diabetes mellitus in Indian and Chinese populations

Nearly half of all adults with type 2 diabetes mellitus (T2DM) live in India and China. These populations have an underlying predisposition to deficient insulin secretion, which has a key role in the pathogenesis of T2DM. Indian and Chinese people might be more susceptible to hepatic or skeletal muscle insulin resistance, respectively, than other populations, resulting in specific forms of insulin deficiency. Cluster-based phenotypic analyses demonstrate a higher frequency of severe insulin-deficient diabetes mellitus and younger ages at diagnosis, lower β-cell function, lower insulin resistance and lower BMI among Indian and Chinese people compared with European people. Individuals diagnosed earliest in life have the most aggressive course of disease and the highest risk of complications. These characteristics might contribute to distinctive responses to glucose-lowering medications. Incretin-based agents are particularly effective for lowering glucose levels in these populations; they enhance incretin-augmented insulin secretion and suppress glucagon secretion. Sodium-glucose cotransporter 2 inhibitors might also lower blood levels of glucose especially effectively among Asian people, while α-glucosidase inhibitors are better tolerated in east Asian populations versus other populations. Further research is needed to better characterize and address the pathophysiology and phenotypes of T2DM in Indian and Chinese populations, and to further develop individualized treatment strategies.

Efficacy and safety profile of sitagliptin, vildagliptin, and metformin in newly diagnosed type 2 diabetic subjects

Type 2 diabetes mellitus (T2DM) is a chronic and progressive disease that requires long-term management. Thus, dipeptidyl peptidase-4 inhibitors (DPP-4) need more investigations about their efficacy and safety profile as there is still no evidence of whether DPP-4 inhibitors can be used as a first line option for T2DM drug-naïve patients. In this randomized case-controlled study, 60 drug-naïve T2DM subjects were randomized into three groups, each group comprising 20 subjects. Group 1 was given sitagliptin 100 mg once daily, Group 2 was given vildagliptin 50 mg twice daily, and Group 3 served as the control group and was given metformin 1 g twice daily. Efficacy endpoints included changes in glycosylated haemoglobin (HbA1c), fasting plasma glucose (FPG), and 2-hr postprandial plasma glucose (PPG), and the secondary endpoints were related to safety profile were the assessment of liver and kidney function tests and complete blood count (CBC). All treatment regimens had comparable efficacy and safety profiles with the non-significant relative superiority of vildagliptin in lowering HbA1c more than sitagliptin but significant (p = 0.011) regarding FPG reduction, vildagliptin significantly decreased HbA1c by -1.02% (p < 0.001), sitagliptin significantly decreased HbA1c by -0.96% (p < 0.001), and control significantly decreased HbA1c by -0.90% (p < 0.001) compared with baseline. The studied drugs showed moderate efficacy in lowering HbA1c levels with the non-significant relative higher efficacy of DPP-4 inhibitors. DPP-4 inhibitors and metformin showed favourable effects on improving metabolic syndrome by decreasing blood pressure, serum triglycerides (TG), low-density lipoprotein (LDL), total cholesterol, and increasing high-density lipoprotein (HDL), plus their positive impacts on weight. As a final conclusion, the three medications are highly comparable.

Impact on decision making framework for medicine purchasing in Chinese public hospital decision-making: determining the value of five dipeptidyl peptidase 4 (DPP-4) inhibitors

BACKGROUND

Medicine purchasing in Chinese public hospitals is decided by the hospital Pharmacy Management Committee (PMC), that is complex, subjective and requires efficient approaches to ensure transparency and consistency for the factors being considered. This study aimed to use the Evidence and Value: Impact on Decision Making (EVIDEM) framework to assess medicine in these hospitals. In this study anti-diabetic drugs DPP-4 inhibitors, which work by inhibiting the activation of the Dipeptidyl Peptidase 4 (DPP-4) inhibitors, were appraised.

METHODS

Following EVIDEM methodology (EVIDEM-10th), we convened an appraisal group and asked each individual to express their perspectives by assigning weights to each criterion. A systematic literature search for information of each criterion of five DPP-4 inhibitors was completed. Then the appraisal group scored for each criterion of the five DPP-4 inhibitors. The estimated value of the five DPP-4 inhibitors was obtained by Multi-Criteria Decision Analysis (MCDA) which combined individual weighting of each criterion with individual scoring for each intervention in each criterion.

RESULTS

By assigning weights, the most important criterion was the quality of evidence (4.01±0.52), and that the comparative cost consequences-non-medical cost was the least important criterion (2.87±1.03). Criteria included disease severity, size of the affected population, comparative effectiveness, type of therapeutic/preventive benefit and cost of intervention, all of which were assigned the same weight of 3.58. After MCDA, the overall value orders for each DPP-4 inhibitor included Sitagliptin (0.45), Linagliptin (0.44), Vildagliptin (0.43), Alogliptin (0.42) and Saxagliptin (0.40).

CONCLUSIONS

Based on EVIDEM framework and MCDA, we found that overall value of five DPP-4 inhibitors was similar. It is feasible to use the EVIDEM framework and MCDA in purchasing medicine for Chinese public hospitals.

Reporting and methodological quality of systematic reviews and meta-analysis with protocols in Diabetes Mellitus Type II: A systematic review

BACKGROUND

Systematic reviews with or without meta-analyses (SR/MAs) are strongly encouraged to work from a protocol to facilitate high quality, transparent methodology. The completeness of reporting of a protocol (PRISMA-P) and manuscript (PRISMA) is essential to the quality appraisal (AMSTAR-2) and appropriate use of SR/MAs in making treatment decisions.

OBJECTIVES

The objectives of this study were to describe the completeness of reporting and quality of SR/MAs, assess the correlations between PRISMA-P, PRISMA, and AMSTAR-2, and to identify reporting characteristics between similar items of PRISMA-P and PRISMA.

METHODS

We performed a systematic review of Type 2 Diabetes Mellitus SR/MAs of hypoglycemic agents with publicly available protocols. Cochrane reviews, guidelines, and specific types of MA were excluded. Two reviewers independently, (i) searched PubMed and Embase between 1/1/2015 to 20/3/2019; (ii) identified protocols of included studies by searching the manuscript bibliography, supplementary material, PROSPERO, and Google; (iii) completed PRISMA-P, PRISMA, and AMSTAR-2 tools. Data analysis included descriptive statistics, Pearson correlation, and multivariable linear regression.

RESULTS

Of 357 relevant SR/MAs, 51 had available protocols and were included. The average score for PRISMA-P was 15.8±3.3 (66%; maximum 24) and 25.2±1.1 (93%; maximum 27) for PRISMA. The quality of SR/MAs assessed using the AMSTAR-2 tool identified an overall poor quality (63% critically low, 18% low, 8% moderate, 12% high). The correlation between the PRISMA-P and PRISMA was not significant (r = 0.264; p = 0.06). Correlation was significant between PRISMA-P and AMSTAR-2 (r = 0.333; p = 0.02) and PRISMA and AMSTAR-2 (r = 0.555; p<0.01). Discrepancies in reporting were common between similar PRISMA-P and PRISMA items.

CONCLUSION

Adherence to protocol reporting guidance was poor while manuscript reporting was comprehensive. Protocol completeness is not associated with a completely reported manuscript. Independently, PRISMA-P and PRISMA scores were weakly associated with higher quality assessments but insufficient as a surrogate for quality. Critical areas for quality improvement include protocol description, investigating causes of heterogeneity, and the impact of risk of bias on the evidence synthesis.

Efficacy and safety of DPP-IV inhibitors combined with basal insulin in the treatment of type 2 diabetes

BACKGROUND

To evaluate the efficacy and safety of dipeptidyl peptidase IV (DPP-IV) inhibitors when added to insulin therapy in patients with type 2 diabetes mellitus (T2DM).

METHODS

PubMed, EMBASE, the Web of Science, and the Cochrane Library were systematically searched for randomized controlled trials (RCTs) exploring the efficacy or safety of DPP-IV inhibitors in T2DM patients. The quality of the included RCTs was assessed with the Cochrane risk-of-bias tool. For outcomes, odds ratios or weighted mean differences (WMDs) with 95% CIs were calculated using both random- and fixed-effects models.

RESULTS

A total of 16 studies were included in the meta-analysis with 5418 participants. Glycosylated hemoglobin (HbA1c) was significantly decreased in the DPP-IV inhibitors with insulin (DPP-IVi/INS) group compared with the insulin-alone (with or without placebo) group (WMD = -0.62%; 95% CI: -0.74, -0.49; P < .05). Consistent with this finding, the fasting blood glucose (FBG)-lowering effect (WMD = -0.61 mmol/L; 95% CI: -0.77, -0.45; P < .05) and 2-hour postprandial glucose (2hPPG)-lowering efficacy (WMD = -2.39 mmol/L; 95% CI: -2.81, -1.97; P < .05) in the DPP-IVi/INS group were also significantly better than in the insulin-alone group. Regarding safety indicators, compared with the insulin-alone group, DPP-IVi/INS treatments had no association with the risk of adverse effects, including hypoglycemia, adverse events (AEs), and serious adverse events (SAEs).

CONCLUSIONS

Compared with insulin treatment alone, treatment with DPP-IVi/INS improved HbA1c, FBG, and 2hPPG without increasing the risk of hypoglycemia, AEs, or SAEs.

Phase III, randomized, double-blind, placebo-controlled study to evaluate the efficacy and safety of teneligliptin monotherapy in Chinese patients with type 2 diabetes mellitus inadequately controlled with diet and exercise

Aims/Introduction

Although the efficacy of teneligliptin, a highly selective dipeptidyl peptidase‐4 inhibitor, has been amply studied for the treatment of type 2 diabetes, no clinical trials of teneligliptin have been carried out in China. We evaluated the efficacy and safety of teneligliptin monotherapy compared with a placebo in Chinese patients with type 2 diabetes mellitus inadequately controlled with diet and exercise.

Materials and Methods

This multicenter, randomized, double‐blind, placebo‐controlled, parallel‐group study, carried out at 42 sites, enrolled type 2 diabetes patients with glycosylated hemoglobin 7.0 to <10.0% and fasting blood glucose <270 mg/dL. Patients were randomly assigned, in a 1:1 ratio, to treatment with 20 mg teneligliptin or a placebo (n = 127, each) administered orally once daily before breakfast for 24 weeks. Change in glycosylated hemoglobin from baseline to week 24 was the primary efficacy end‐point. Safety was assessed by the incidence of adverse events and adverse drug reactions.

Results

The least square mean (LSM) change in glycosylated hemoglobin from baseline to week 24 was −0.95% with teneligliptin versus −0.14% with a placebo, yielding an LSM difference (teneligliptin vs placebo) of −0.80% (P < 0.0001). For the secondary end‐point, from baseline to week 24, the LSM change in fasting blood glucose was −21.9 mg/dL with teneligliptin versus −1.4 mg/dL with a placebo, yielding an LSM difference (teneligliptin vs placebo) of −20.5 mg/dL (P < 0.0001). The adverse event and adverse drug reaction incidence rates, including hypoglycemia, were similar in both groups.

Conclusions

At 24 weeks, teneligliptin was generally well tolerated and effective in Chinese patients with type 2 diabetes mellitus inadequately controlled with diet and exercise.

Acarbose With Comparable Glucose-Lowering but Superior Weight-Loss Efficacy to Dipeptidyl Peptidase-4 Inhibitors: A Systematic Review and Network Meta-Analysis of Randomized Controlled Trials

Background: Acarbose and dipeptidyl peptidase-4 inhibitors (DPP-4is) have several similarities regarding their efficacy. Assessing the hypoglycemic and weight-loss effects, as well as the tolerability between them at their optimal dosages, could provide a better management of adult type 2 diabetics. Methods: We performed a systematic review and network meta-analysis (NMA) on randomized controlled trials that were identified from the databases of EMBASE, MEDLINE, Cochrane Central Register of Controlled Trials, Web of Science, Conference Proceedings Citation Index, ClinicalTrials.gov, China National Knowledge Infrastructure, Wan Fang, and SinoMed. The trials with 300 mg/day of acarbose or the recommended doses of DPP-4is were the most optimal for our NMA. The mean differences (MD) and relative risk (RR) derived from eligible studies were used. Results: Among the 15,411 obtained potential studies, 13 pair-wise trials and 48 monotherapy studies were included in the meta-analysis and NMA, respectively. DPP-4is had a greater glucose-lowering effect, but a weaker weight-loss effect than acarbose in pair-wise meta-analysis (p < 0.05). However, NMA with 11,877 participants showed that, at their optimal doses, acarbose and DPP-4is had similar glucose-lowering effects on the 2-h postprandial glucose (MD 0.96 mmol/L, 95% credible interval -0.56 to 2.54), HbA1c (0.05%, -0.25 to 0.33), fasting plasma glucose reductions (-0.27 mmol/L, -0.76 to 0.24), and HbA1c < 7.0% target goal achievement (RR 1.33, 0.51 to 3.64). Acarbose was superior to DPP-4is regarding weight loss (MD -1.23 kg, -2.08 to -0.33). Acarbose had more withdrawal, gastrointestinal, and overall adverse events than DPP-4is (p < 0.05), but the differences disappeared after longer treatment (p > 0.05). Conclusions: Acarbose and DPP-4is have similar glucose-lowering effects, but the weight-loss effects of acarbose are superior. Therefore, in the use of the most optimal dosages, overweight/obese type 2 diabetics might benefit more from a treatment with acarbose than DPP-4is.