Effect of acarbose versus sulfonylurea therapy on insulin sensitivity: An insulin clamp study

Objective The goal of this study was to assess the effect of acarbose on insulin sensitivity by using the euglycemic hyperinsulinemic clamp technique while maintaining glycemic control, body mass index (BMI), and exercise levels as constant as possible. Background: Few studies showed that acarbose improved insulin sensitivity. Methods: Eleven patients with type 2 diabetes mellitus were given acarbose (300 mg/d, n = 5) or sulfonylurea (glibenclamide 1.25 to 2.50 mg/d or gliclazide 20 mg/d, n = 6) therapy. The first insulin clamp study was performed when glycosylated hemoglobin A(1c) (Hb A(1c)) levels decreased to less than or equal to 8%, and the second study was performed similar to 6 months later. During this period, patients' daily exercise level and BMI were kept constant. In addition, Db A(1c) levels were kept as stable as possible by modifying drug doses. Multiple regression analysis was used to assess the influence of acarbose on the changes in insulin sensitivity with adjustment for the changes in Hb A(1c) and BMI between the 2 insulin clamp tests. Results: No significant changes in daily exercise load or BMI were noted between the first and second insulin clamp studies; Hb A(1c) levels improved significantly (P = 0.016). M-values improved significantly in the acarbose group (P = 0.015) compared with the sulfonylurea group. Even after adjusting for the changes in Hb A(1c) and BMI between the 2 insulin clamp studies, acarbose therapy achieved significantly greater improvement in M-values (P < 0.001) than did sulfonylurea therapy. Conclusions: Based on these findings, acarbose improves insulin sensitivity in patients with type 2 diabetes mellitus.