Effectiveness and Adverse Effects of Dapagliflozin Compared with Sitagliptin Combined with Metformin in Type 2 Diabetes Mellitus – an Open Labelled Randomized Controlled Trial

Abstract

Background: In the management of mild to moderate Type 2 Diabetes Mellitus (T2DM), sodium-glucose co-transporter-2 (SGLT-2) inhibitors and dipeptidyl peptidase-4 (DPP-4) inhibitors are commonly preferred as add-on therapies to Metformin, owing to their more favorable safety profiles relative to sulphonylureas and insulin. Nevertheless, there is a paucity of data comparing their efficacy and safety within the South Indian population.

Objective: To compare the effectiveness and adverse effect profile of Dapagliflozin and Sitagliptin, each combined with Metformin, in patients with T2DM.

Methods: In this open-label randomized controlled trial, a total of 60 patients with Type 2 Diabetes Mellitus (T2DM) were randomized to receive either Dapagliflozin (Group A) or Sitagliptin (Group B), each in combination with Metformin, over a duration of three months. Fasting blood sugar (FBS), postprandial blood sugar (PPBS), and glycated hemoglobin (HbA1c) levels were evaluated on a monthly basis, and patients were closely monitored for any adverse events.

Results: The study demonstrated that both treatment groups—Dapagliflozin and Sitagliptin in combination with Metformin—were comparable at baseline in terms of age, gender, and glycemic parameters. The mean age was 56 ± 2.9 years in the Dapagliflozin group and 55 ± 5.2 years in the Sitagliptin group (p = 0.826), with no significant gender difference (p = 0.604). Baseline FBS, PPBS, and HbA1c were also similar between the groups: 161 ± 8.1 mg/dL, 214 ± 12.1 mg/dL, and 7.4 ± 0.16% in the Dapagliflozin group; and 160 ± 5.7 mg/dL, 207 ± 5.9 mg/dL, and 7.3 ± 0.14% in the Sitagliptin group (all p > 0.7). Over three months, both groups showed significant intragroup reductions in glycemic indices (p < 0.001). However, Sitagliptin achieved greater reductions, with FBS declining to 112 ± 2.9 mg/dL, PPBS to 138 ± 4.8 mg/dL, and HbA1c to 6.4 ± 0.11%, all significantly lower than those in the Dapagliflozin group (128 ± 6.1 mg/dL, 166 ± 4.8 mg/dL, and 6.7 ± 0.16%; p < 0.001). Liver and renal function tests remained stable in both groups throughout the study, indicating good safety and tolerability.

Conclusion: In this South Indian cohort, the combination of Sitagliptin with Metformin demonstrated superior glycemic control compared to Dapagliflozin and was associated with a more favorable safety profile, notably reflected by a lower incidence of urinary tract infections.