Comparing the efficacy and safety of sitagliptin versus glimepiride in combination with metformin in geriatric type 2 diabetes mellitus patients

Objectives: Type 2 diabetes mellitus (T2DM) is a growing public health concern, particularly among the geriatric population, where disease management becomes complex due to age-related physiological changes and comorbidities. Although metformin remains the first-line therapy, additional agents such as sulfonylureas (e.g. glimepiride) and Dipeptidyl peptidase-4 (DPP-4) inhibitors (e.g. sitagliptin) are often required for adequate glycaemic control. This study aims to evaluate and compare the safety and efficacy of sitagliptin and glimepiride as add-on therapies to metformin in elderly patients with T2DM from the North Indian population. Materials and Methods: This randomised, prospective, interventional, active-controlled study was conducted over 1 year at King George’s Medical University, Lucknow, following ethical approval. A total of 60 geriatric patients (≥60 years) with newly diagnosed or uncontrolled T2DM on metformin were randomised into two groups: Group A received metformin (500 mg BD) + glimepiride (1 mg OD), and Group B received metformin (500 mg BD) + sitagliptin (100 mg OD). Baseline and follow-up evaluations were conducted at 4, 8 and 12 weeks, assessing clinical and biochemical parameters including glycated hemoglobin (HbA1c), fasting blood glucose (FBG), lipid profile, weight, body mass index (BMI) and blood pressure (BP). Statistical analyses included Chi-square test, unpaired t -tests and Mann–Whitney U-test. Results: Both treatment groups showed significant improvements in glycaemic parameters over 12 weeks. However, the reduction in HbA1c was not significantly different between the groups ( P = 0.7). While reductions in FBG were observed in both groups, the intergroup difference was not statistically significant. Lipid profile parameters remained largely unchanged in both groups, though a non-significant trend toward improved low-density lipoprotein-cholesterol levels was seen in the sitagliptin group ( P = 0.15). Notably, the sitagliptin group maintained significantly lower weight and BMI throughout the study ( P < 0.001 at all time points). No significant differences were observed in systolic or diastolic BP. Safety evaluation was limited due to the lack of time. Conclusion: Sitagliptin, when combined with metformin, demonstrated better weight management compared to glimepiride in elderly patients with T2DM, with no significant impact on other parameters. These findings support the preferential use of sitagliptin over glimepiride as an add-on therapy to metformin in geriatric T2DM patients, particularly for those at risk of comorbidities. Further long-term studies are warranted to validate these results and assess safety profiles comprehensively.