Abstract
Introduction: Type 2 diabetes mellitus (T2DM) is a metabolic disorder requiring combination treatment for achieving and maintaining adequate glycemic control. Both combination treatments, including dipeptidyl peptidase-4 (DPP-4) inhibitors such as sitagliptin and sodium–glucose co-transporter 2 (SGLT2) inhibitors such as dapagliflozin, are frequently prescribed as add-on agents to metformin; however, relative effectiveness when used in fixed combinations remains an area of active investigation.
Objectives: This study was conducted to compare the efficacy of sitagliptin/metformin and dapagliflozin/metformin on glycemic control in patients with T2DM.
Materials and Methods: This randomized, open‑label, clinical trial was conducted on T2DM patients recruited from two central teaching hospitals in Iraq from June to December 2025. Eligible and consenting patients were randomly allocated in a 1:1 ratio to receive either sitagliptin/metformin (50/500 twice daily) or dapagliflozin/metformin (10/1000 daily) and were followed prospectively for 12 weeks. Baseline and follow‑up assessments included demographic and clinical data and measurement of glycemic indices (HbA1c, fasting blood sugar [FBS], and 2‑hour postprandial blood sugar [2hPP-BS]), and efficacy analyses compared changes in these parameters between and within treatment groups using standard statistical tests at a two‑sided significance level of 0.05.
Results: The results showed that both treatment groups showed significant improvements in glycemic parameters compared with baseline. However, the dapagliflozin plus metformin group demonstrated consistently greater reductions across all glycemic parameters, including HbA1c (↓1.48% versus ↓0.80%), FBS (↓50.64 versus 34.19 mg/dL), and postprandial BS (↓77.93 versus ↓35.86 mg/dL), compared to the sitagliptin/metformin combination after 12-week follow-up, indicating superior efficacy relative to the sitagliptin-based regimen.
Conclusion: Dapagliflozin demonstrated a more significant improvement in glycemic control parameters compared to sitagliptin, although both treatment regimens were effective. These findings support the preferential consideration of a dapagliflozin-based treatment regimen for improved glycemic management.
Trial Registration: The trial protocol was registered at the Iraqi Clinical Research Registry (Registration No: ICRR-2025-121) and approved by the Medicine College of Baghdad University and the Pharmacy College of Al-Mustansiriyah University in Iraq.