Complementary glucagonostatic and insulinotropic effects of DPP-4 inhibitors in the glucose-lowering action in Japanese patients with type 2 diabetes

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.