Efficacy of dipeptidyl-peptidase-4 inhibitors and impact on β-cell function in Asian and Caucasian type 2 diabetes mellitus patients: A meta-analysis

BackgroundThis work aimed to compare the efficacy of dipeptidyl peptidase-IV (DPP-4) inhibitors and their impact on -cell function in Asian and Caucasian patients with type 2 diabetes mellitus. MethodsDatabases were systematically searched and qualifying studies that compared DPP-4 inhibitors with other antidiabetic medications in type 2 diabetes were included. ResultsA total of 68 studies were included in the meta-analysis. Comparison of DPP-4 inhibitors with placebo in Asian patients showed a decrease in glycosylated hemoglobin (HbA(1c)) favoring DPP-4 inhibitors (weighted mean difference [WMD], -0.81%; 95% confidence interval [CI], -0.95% to -0.68%; P<0.001). Comparison of HbA(1c) changes between Asian and Caucasian patients showed a significant between-group difference of -0.18% (95% CI, -0.32% to -0.04%; P=0.011) when compared with placebo. In Asian patients, the homeostatic model assessment for -cell function (HOMA-) was increased with DPP-4 inhibitors compared with placebo (WMD, 7.90; 95% CI, 4.29 to 11.51; P<0.001), although to a lesser extent in Caucasian patients. Comparisons between Asian and Caucasian patients showed a significant between-group difference of -4.97 (95% CI, -9.86 to -0.09; P=0.046) compared with placebo. Body weight increase with DPP-4 inhibitors compared with placebo was comparable in Asian and Caucasian studies (WMD, 0.37kg and 0.45kg and 95% CI, 0.04-0.69 and 0.27-0.62, respectively). ConclusionsThe glucose-lowering efficacy of DPP-4 inhibitors was greater in Asian patients than in Caucasian patients, although the effect on -cell function was inferior in Asian patients. The effect of DPP-4 inhibitors on insulin resistance and body weight in Asian patients was comparable with that observed in Caucasian patients.