Effects of Olmesartan, an Angiotensin II Receptor Blocker, and Amlodipine, a Calcium Channel Blocker, on Cardio-Ankle Vascular Index (CAVI) in Type 2 Diabetic Patients with Hypertension

Aim: Recently, a novel device for measuring the cardio-ankle vascular index (CAVI) as an arterial stiffness parameter has been developed. In this study, we evaluated the effect of angiotensin II receptor blocker (ARB) and calcium channel (Ca) blocker on CAVI in type 2 diabetic patients with hypertension.Methods: Seventy type 2 diabetes mellitus patients with hypertension were enrolled and randomly divided into two groups. One group was administered olmesartan medoxomil 20 mg/day for 12 months (ARB group), and the other group was administered amlodipine besilate 5 mg/day for 12 months (Ca blocker group).Results: In the ARB group, a significant decrease in CAVI was observed after 12 months; however, no significant change in CAVI was observed in the Ca blocker group although changes in blood pressure were almost the same. By simple regression analyses, CAVI changes correlated positively with 8-OHdG changes.Conclusions: Olmesartan, an ARB, improved arterial stiffness more than amlodipine, and this effect might be due to not only the blood pressure-lowering effect but also to reducing the potential of oxidative stress recognized in olmesartan.