Efficacy of Dipeptidyl Peptidase-4 Inhibitors on Leptin in type 2 Diabetes Mellitus: A Meta-Analysis

Background: Dipeptidyl peptidase-4 inhibitors (DPP-4i) provide a unique anti-hyperglycemic effect through regulating incretin peptides in type 2 diabetes mellitus (T2DM) patients that are inadequately controlled with insulin therapy. The aim of this study was to investigate the impact of DPP-4i on leptin concentrations in subjects with T2DM. Methods: Randomized controlled trials (RCTs) with comparators were identified through systematically searching PubMed, Embase, and Cochrane library. Quantitative analysis was performed with a fixed or random-effects model according to heterogeneity. Publication bias was evaluated by using the standard methods for sensitivity analysis. Results: Ten trials with 698 patients with T2DM were included. Pooled analysis demonstrated that DPP-4i did not significantly change leptin concentrations (1.31 ng/mL, 95% CI, -0.48 to 3.10). DPP-4i exerted no stronger effect on modulating leptin levels compared to active comparators (0.21 ng/mL, 95% CI, -1.37 to 1.78). Meta-analysis was powerful and stable after sensitivity analysis.Conclusions: DDP-4i did not modulate leptin concentrations and exerted no stronger effect than traditional antidiabetic agents.