Association between asymmetric dimethylarginine and indices of vascular function in patients with essential hypertension.

Asymmetric dimethylarginine (ADMA) is an endogenous inhibitor of nitric oxide synthase and is associated with endothelial dysfunction. The aim of the present study was to investigate the relationship between ADMA, indices of arterial stiffness, endothelial function and carotid artery intima-media thickness (IMT) in hypertension patients. Eighty middle-aged (47 ± 10 years) untreated patients with mild to moderate essential hypertension underwent routine physical examination, pulse wave analysis (PWA), measurement of aortic pulse wave velocity (PWV) and IMT. In PWA, administration of salbutamol and nitroglycerine was used to assess endothelium-dependent (EDV) and endothelium-independent vasodilation, respectively. In univariate analysis, ADMA was correlated with EDV (r = -0.26; p = 0.02) and IMT (r = 0.32; p = 0.007). In multiple regression analysis, ADMA was independently associated with the female gender, EDV, IMT and total cholesterol (R(2) = 0.30; p < 0.001). No correlation was detected between ADMA and augmentation index, central/brachial blood pressure or aortic PWV. In hypertension patients, ADMA is independently correlated with IMT and EDV. Thus, ADMA is a marker of endothelial dysfunction and intima-media thickening in patients with hypertension.