Contribution of glimepiride to basal–prandial insulin therapy in patients with type 2 diabetes

Abstract

Aim To investigate the efficacy of continuing glimepiride in combination with basal–prandial insulin therapy in type 2 diabetes. Methods An open crossover study was performed with arms of discontinuation and continuation of glimepiride in 25 subjects with mean diabetes duration of 17 years and 5 years of insulin treatment combined with glimepiride plus metformin. At entry and at the end of each 3-month arm, meal tolerance tests were performed for measurements of blood glucose and C-peptide. Results In terms of between-treatment differences (discontinuation vs. continuation arm of glimepiride) during meal tolerance tests performed at the ends of arms, significant increases in plasma glucose were seen on the discontinuation arm at 0-, 30-, and 60-min, while significant decreases in serum C-peptide were observed at 60- and 120-min. A1C values of the discontinuation arm significantly increased (from 6.6 ± 0.6 at baseline to 7.7 ± 0.8 at 3-months, p < 0.0001). Increases in A1C were closely correlated with decreases in area under the curve of meal-stimulated serum C-peptide ( r = −0.61, p < 0.0001). Conclusions Since endogenous insulin secretion is more physiological than subcutaneous insulin injection, continuing glimepiride may remain beneficial, partly through enhancing insulin secretion, in individuals with a long duration of diabetes and basal–prandial insulin therapy.