Abstract
Background: Flow-mediated dilation (FMD) and nitroglycerin-induced dilation (NMD) in the brachial artery are well-known indices for evaluating endothelial function (ECF). The fixed-dose combination of olmesartan, an angiotensin receptor blocker (ARB, 10 mg), and azelnidipine (Ca-channel blocker; CCB, 8 mg: ARB-CCB) might effectively lower blood pressure in patients with uncontrolled hypertension and possibly ameliorate ECF. Methods: To investigate the subacute effect of low dose ARB-CCB on ECF in hypertensive patients uncontrolled by amlodipine (2.5 mg daily), 42 patients were randomly assigned to an amlodipine dose maintenance group with additional behavioral modification such as diet and/or exercise therapy (CTRL group, n=21, age 71±5 years) or to an amlodipine dose maintenance group with the same behavioral modification and an ARB-CCB (ARB-CCB-group, n=21; age 70±7 years). Before and after 4 weeks of therapy, FMD and NMD were measured in both groups. Results: Although the baseline FMD was not different between the two groups, FMD increased in the ARB-CCB group (2.89% ± 0.77% to 4.01% ± 1.08%, P<0.01), whereas no significant change was seen in the CTRL group (3.01% ± 0.53% to 3.08% ± 1.22%, NS). Changes in NMD did not differ between the two groups. Blood pressure was decreased significantly more in the ARB-CCB group than in the CTRL group. Conclusions: The addition of even a low dose of a fixed-dose combination of olmesartan and azelnidipine had a significant ameliorating effect on ECF subacutely, suggesting that this combination might have both antihypertensive and anti-atherosclerotic effects in hypertensive patients.
