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

Aims: Glimepiride, a third generation sulfonylurea (SU), is known to have extrapancreatic 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 by glimerpiride.