Efficacy of different antidiabetic drugs based on metformin in the treatment of type 2 diabetes mellitus: A network meta-analysis involving eight eligible randomized-controlled trials

Diabetes mellitus is one of the most prevalent metabolic diseases globally and it is increasing in prevalence. It is one of the most expensive diseases with respect to total health care costs per patient as a result of its chronic nature and its severe complications. To provide a more effective treatment of type 2 diabetes mellitus (T2DM), this study aims to compare different efficacies of six kinds of hypoglycemic drugs based on metformin, including glimepiride, pioglitazone, exenatide, glibenclamide, rosiglitazone, and vildagliptin, in T2DM by a network meta-analysis that were verified by randomized-controlled trials (RCTs). Eight eligible RCT in consistency with the aforementioned six hypoglycemic drugs for T2DM were included. The results of network meta-analysis demonstrated that the exenatide + metformin and vildagliptin + metformin regimens presented with better efficacy. Patients with T2DM with unsatisfactory blood glucose control based on diet control, proper exercise, and metformin treatment were included. The original regimen and dose of medication were unchanged, followed by the addition of glimepiride, pioglitazone, exenatide, glibenclamide, rosiglitazone, and vildagliptin. The results of RCTs showed that all these six kinds of drugs reduced the HbA1c level. Compared with other regimens, exenatide + metformin reduced fasting plasma glucose (FPG), fasting plasma insulin (FPI), total cholesterol (TC), and homeostasis model assessment insulin resistance index (HOMA-IR) levels, but increased the high-density lipoprotein (HDL) level; vildagliptin + metformin decreased FPI and low-density lipoprotein (LDL) levels; glibenclamide + metformin decreased the FPG level, but promoted HDL; and glimepiride + metformin decreased the TC level and rosiglitazone + metformin reduced the LDL level. Our findings indicated that exenatide + metformin and vildagliptin + metformin have better efficacy in T2DM since they can improve insulin sensitivity.