Efficacy and Tolerability of Sitagliptin Compared with Glimepiride in Elderly Patients with Type 2 Diabetes Mellitus and Inadequate Glycemic Control: A Randomized, Double-Blind, Non-Inferiority Trial.

Objective: The aim of this study was to evaluate the efficacy and tolerability of sitagliptin compared with glimepiride in elderly patients with type 2 diabetes mellitus (T2DM) and inadequate glycemic control with diet and exercise alone.
Methods: This was a randomized, parallel-group, multinational, non-inferiority clinical trial with an active-controlled, double-blind treatment period in which patients ≥ 65 and ≤ 85 years of age with T2DM were screened at 85 sites. Patients were randomized to once-daily sitagliptin (100 or 50 mg, depending on renal function) or glimepiride (in titrated doses) for 30 weeks. The main outcome measures were change from baseline in glycated hemoglobin (HbA1c), fasting plasma glucose (FPG), and body weight; and the incidence of symptomatic hypoglycemia.
Results: The mean baseline HbA1c was 7.8% in both the sitagliptin group (n = 197) and the glimepiride group (n = 191). After 30 weeks, the least squares (LS) mean change in HbA1c baseline was -0.32% with sitagliptin and -0.51 % with glimepiride, for a between-group difference (95% CI) of 0.19% (0.03-0.34). This result met the pre-specified criterion for declaring non-inferiority, which required that the upper 95% confidence limit lie below 0.4%. The LS mean change in FPG from baseline was -14.5 mg/dL with sitagliptin and -21.2 mg/dL with glimepiride, for a between-group difference (95% CI) of 6.7 mg/dL (0.7-12.7). The percentages of patients with adverse events of symptomatic hypoglycemia were 0.8% in the sitagliptin group and 4.7% in the glimepiride group (between-treatment difference = -3.9%, p = 0.009). The LS mean change in body weight from baseline was 0.4 kg with sitagliptin and 1.1 kg with glimepiride, for a between-group difference of -0.7 kg (p = 0.011).
Conclusion: In elderly patients with T2DM and inadequate glycemic control with diet and exercise alone, sitagliptin provided non-inferior glycemic control after 30 weeks of treatment compared with glimepiride. Compared with glimepiride, sitagliptin had a lower risk of hypoglycemia. Sitagliptin was weight-neutral; while the between-group difference in change from baseline in body weight was statistically significant, the modest difference may not be clinically meaningful.
Study Identifier: ClinicalTrials.gov NCT01189890.