Plasma endothelin-1 (ET-1) and von Willebrand factor (vWF) levels are elevated in the presence of either macro- or microvascular lesions. Since an increased risk to develop hypertension-related vascular damage has been suggested in human sensitive hypertension, we evaluated both substances in plasma samples from 20 non-diabetic, non obese essential hypertensive men (mean age 49 +/- 4 years). Patients were divided in salt sensitive (n = 9) or salt resistant (n = 11) groups, according to the individual response to both high- and low-sodium diets. Plasma ET-1 levels were also assessed after an oral glucose tolerance test (75 g). Both ET-1 and vWF were higher in salt sensitive than salt resistant patients (ET-1 p < 0.01; vWF p < 0.03). Furthermore, after oral glucose administration, plasma ET-1 concentrations increased very mildly but significantly only in salt sensitive patients (p < 0.05 at 90 min). In conclusion, human salt sensitive hypertension is combined to increased levels of two markers of endothelial damage, and by an augmented ET-1 response to glucose leading, suggesting it is characterized by an increased risk to develop hypertension-related vascular complications.