Effect of Nisoldipine and Olmesartan on Endothelium‐Dependent Vasodilation in Essential Hypertensive Patients

Abstract

To investigate whether nisoldipine and olmesartan improve endothelial function, decrease asymmetric dimethylarginine (ADMA) and alleviate the inflammatory and oxidative process. Fifty-five essential hypertensive patients were randomized to receive nisoldipine or olmesartan for 8 weeks according to a parallel-group, active-controlled, single blind study, and 28 matched normotensive subjects served as healthy controls. Flow-mediated dilation (FMD), and plasma levels of nitric oxide (NO), endothelin-1 (ET-1), high-sensitive C-reactive protein (hs-CRP), 8-isoprostane (also named 8-isoPGF2α), and ADMA were determined. At baseline, the plasma levels of ADMA, ET-1, hs-CRP, and 8-isoPGF2α were markedly higher in patients with essential hypertension than in normotensive subjects (P < 0.05). A significant positive correlation was observed between plasma levels of ET-1 and ADMA in patients with essential hypertension, but not in normotensive subjects. The NO plasma concentrations were significantly lower in patients with essential hypertension than in normotensive subjects. Furthermore, hypertensive subjects demonstrated significantly lower FMD than healthy control (P < 0.05). Nisoldipine and olmesartan significantly and similarly reduced blood pressure in patients with essential hypertension (P < 0.001). At the end of the 8-week treatment, plasma ADMA and ET-1 levels were decreased significantly (P < 0.01). FMD increased significantly in nisoldipine or olmesartan-treated patients (P < 0.05). A significant decrease in plasma hs-CRP contents was observed in patients receiving nisoldipine (P < 0.05). The findings demonstrate that nisoldipine and olmesartan both improve FMD in patients with essential hypertension. This may be associated with decreased circulating levels of CRP, ET-1, and ADMA.