Improvement of cardio-ankle vascular index by glimepiride in type 2 diabetic patients

Aims: Glimepiride, a third generation sulfonylurea (SU), is known to have extra-pancreatic effects, but its vascular effect is unclear. We investigated the efficacy of glimepiride in improving arterial stiffness assessed by cardio-ankle vascular index (CAVI) in type 2 diabetic patients, compared with glibenclamide, a conventional SU. Methods: Forty type 2 diabetic patients were randomly assigned to two groups. One group was administered glimepiride 1.5 mg/day, and the other group was administered glibenclamide 1.25 mg/day for 6 months. Results: No significant difference in hypoglycaemic effect was observed between two groups. CAVI significantly decreased only in glimepiride group (9.4 +/- 1.4 -> 8.9 +/- 0.8, p < 0.05). Decrease in CAVI was greater in glimepiride group than in glibenclamide group (-0.50 +/- 0.98 vs. -0.04 +/- 0.57, p = 0.048). Urinary 8-hydroxy-2'-deoxyguanosine (8-OHdG) decreased in glimepiride group and increased in glibenclamide group, and the changes were significantly different between groups (-1.5 +/- 3.5 vs. + 1.8 +/- 3.6, p = 0.009); whereas serum lipoprotein lipase mass increased in glibenclamide group and decreased in glibenclamide group, and the changes tended to be different between groups (+ 2.1 +/- 19.1 vs. -7.4 +/- 19.2, p = 0.096). Change in urinary 8-OHdG was a significant independent predictor for change in CAVI in all subjects. Conclusions: These results suggest that glimepiride improves CAVI compared with glibenclamide. Reduced oxidative stress and improved insulin resistance may contribute to the improvement of CAVI bypancreatic .