Dapagliflozin Versus Vildagliptin as an Adjuvant to Metformin in Patients With Type 2 Diabetes Mellitus: A Randomized, Open-label Study

Introduction: The rising burden of diabetes mellitus led to the development of novel drugs like dapagliflozin and vildagliptin. Their efficacies in chronic diabetic patients have been thoroughly studied. However, there is a paucity of comparative studies on these drugs in newly diagnosed diabetic patients. The endpoints of our study were changes in glycated hemoglobin (HbA(1c)), fasting blood glucose (FBG), and postprandial blood glucose (PPBG) at 24 weeks from baseline. Methods: This randomized, open-label, 24-week study was conducted at Kalinga Institute of Medical Sciences, Bhubaneswar, India, from January 2021 to November 2022. The participants were randomized in a 1:1 ratio to receive tablets of either dapagliflozin 10mg once daily or vildagliptin 50mg once daily as an add-on to metformin 500-2000 mg. The analyses were performed in the per-protocol population. We used R software v. 4.1.1 (R Foundation, Indianapolis, IN) for data analysis. Results: 114 (83.8%) of 136 enrolled participants completed this study. The mean age of the study population was 41.08±5.17 years. Additionally, 52 (45.6%) of them were females. The mean changes in HbA(1c) from baseline were -1.19 (95% CI: -1.36 to -1.03) and -1.28 (95% CI: -1.37 to -1.18) in dapagliflozin and vildagliptin groups, respectively (p=0.21). The median changes in FBG and PPBG in both groups were -38.76, -46.13 (p=0.07), and -51.84, -53.56 (p=0.14), respectively. Conclusions: Reductions in HbA(1c), FBG, and PPBG with add-on treatment of vildagliptin were more pronounced than dapagliflozin after a 24-week intervention. However, the differences were not statistically significant.