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

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.
(Copyright © 2010 Elsevier Ireland Ltd. All rights reserved.)