Effects of Irbesartan on endothelial function and autonomic nervous system activity of patients with essential hypertension / 第三军医大学学报

ABSTRACT

Objective To investigate the effects of Irbesartan on endothelial function and autonomic nervous system activity of patients with essential hypertension. Methods The endothelium dependent flow mediated dilatation (F-MD) and the endothelium independent nitroglycerin mediated dilatation (NTG-MD) were evaluated by the brachial ultrasound examination. Time-domain indices of heart rate variability (HRV) were measured by 24 h ambulatory electrocardiogram. The changes of blood lipoproteins, blood glucose, insulin levels, endothelial function and heart rate variability in 60 patients with mild-moderate essential hypertension and 20 healthy controls were compared, and the effects of different antihypertensive agents (AT1 receptor blocker and diuretic) for 8-week treatment were observed. Results Endothelial dysfunction and abnormal autonomic nervous activity were observed in patients with mild-moderate essential hypertension as follow: mildly decreased total HRV and mildly increased 24-hour average heart rate, significantly decreased parasympathetic tone-rMSSD and PNN50, obviously lowered endothelium dependent F-MD. The postprandial insulin level and insulin/glucose ratio of patients with hypertension was significantly higher than that of healthy controls. The decreased blood pressure level caused by AT1 receptor blocker (Irbesartan) and diuretic (Indapamide) was similar. Irbesartan for 8-week therapy resulted in a significant improvement of the endothelium dependent F-MD and insulin resistence, the increase of vagal nervous activity and the decrease of 24-hour average heart rate, but Indapamide presented no such effects. Conclusion This study suggested that patients with mild-moderate essential hypertension have significantly abnormal endothelial function and autonomic nervous activity, and the beneficial effect of Irbesartan is associated with an improvement of insulin resistence and heart rate variability, not with the decrease of blood pressure level.