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

Abstract

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.