Comparison of effects of amlodipine and angiotensin receptor blockers on the intima–media thickness of carotid arterial wall (AAA study: Amlodipine vs. ARB in atherosclerosis study)

Although there have been increasing reports, which suggest that angiotensin receptor blockers (ARBs) may have anti-atherogenic actions, most of them are performed in vitro and there are a few reports about anti-atherogenic action in vivo. Especially, in humans, there have been no reports about effect of ARBs on atheroslocerosis. On the other hand, there have been several reports, including ours, which indicate that amlodipine, a calcium channel blocker, has a unique property to cause a reduction in the intima–media thickness (IMT) of common carotid artery, which is established to be an indicator of early atherosclerotic lesion, in humans. The present study investigated which of amlodipine and/or ARBs might have more profound effect on IMT progression.The study included 104 hypertensive patients with type 2 diabetes. They were divided into the two groups: the amlodipine group (n = 58), who received amlodipine (2.5–5 mg/day) and the ARB group (n = 46), who received losartan (25–50 mg/day), candesartan (4–8 mg/day), valsaratan (40–80 mg/day) or telmisartan (20–40 mg/day). IMT changes were examined during an average of 56.9 weeks. The amlodipine group showed a significant decrease in IMT compared to the ARB group (−0.046 [S.E. 0.161] mm vs. 0.080 [S.E. 0.255] mm, P < 0.05).These results suggest that amlodipine has an inhibitory effect on early atherosclerotic process, and that ARBs do not have any effect on it in hypertensive patients with type 2 diabetes.