Comparison of the efficacy of sitagliptin and glimepiride dose-up in Japanese patients with type 2 diabetes poorly controlled by sitagliptin and glimepiride in combination

Abstract

Aims/Introduction: The goal of the study was to examine the effects of sitagliptin dose-up or glimepiride dose-up in Japanese patients with type 2 diabetes who were controlled inadequately by sitagliptin and glimepiride in combination. Materials and Methods: A multicenter, prospective, randomized, open-label study was carried out in 50 patients with type 2 diabetes treated with sitagliptin and low-dose glimepiride. The patients were randomly assigned to receive the addition of 50 mg/day sitagliptin or 0.5 mg/day glimepiride. The primary end-point was the percentage change in glycated hemoglobin (HbA1c). Results: During a follow-up period, the difference in the percentage changes in HbA1c between the two groups was not significant (P = 0.13). However, HbA1c was significantly decreased by glimepiride dose-up (P < 0.01 vs baseline), but not by sitagliptin dose-up (P = 0.74). Univariate linear regression analyses showed that the percentage change in HbA1c was significantly associated with the serum level of arachidonic acid (AA) in both groups. Conclusions: There was no significant difference in the HbA1c-lowering effects between the two groups. However, a significant HbA1c-lowering effect from baseline of glimepiride dose-up was found, and the AA level showed a negative correlation with the decrease in HbA1c in the sitagliptin dose-up group, but a positive correlation in the glimepiride dose-up group. These findings suggest that the AA level is associated with HbA1c reduction in response to dose-up with these drugs in patients with type 2 diabetes in a combination therapy with sitagliptin and glimepiride. This trial was registered with UMIN (no. 000009544). © 2013 The Authors. Journal of Diabetes Investigation published by Asian Association of the Study of Diabetes (AASD) and Wiley Publishing Asia Pty Ltd.