PLASMA ENDOTHELIN-1 IS ASSOCIATED WITHAORTIC STIFFNESS IN ESSENTIAL HYPERTENSION

Background: Experimental studies documented that endothelin-1 (ET-1) contributesto arterial stiffness and recently, in patients with chronic kidney diseases,it has been observed that selective endothelin-A receptor antagonism reducesarterial stiffness, in part independently of blood pressure lowering. Little isknown about the relationships between ET-1 plasma levels and aortic distensibilityin subjects with essential hypertension.Objective: The aim of our study was to analyse the relationships betweenplasma concentrations of ET-1 and carotid-femoral pulse wave velocity (c-fPWV), as an index of aortic stiffness, in a group of hypertensive patients withoutovert renal insufficiency [estimated glomerular filtration rate (eGFR) < 60ml/min/1.73 m2].Methods: We enrolled 216 pharmacologically untreated hypertensive patients(mean age 46 ± 10 years, males 62%). In all the subjects routine biochemicalparameters and ET-1 plasma values, measured by a solid-phase specific sandwichenzyme-linked immunosorbent assay (Amersham kits), were obtained.Moreover, ambulatory blood pressure monitoring and measurement of c-fPWV, by a computerized automatic method (Complior), were performed.Results: The patients (n = 41) with elevated values of c-f PWV (> 12 m/sec)showed significantly higher ET-1 plasma levels than those of subjects withPWV < 12 m/sec (3.43 ± 0.43 vs 3.18 ± 0.42 pg/ml; p = 0.001 and p = 0.01,before and after adjustment for age and mean arterial pressure). A statisticalsignificant correlation was found between ET-1 and c-f PWV in the wholestudy population (r = 0.29; p < 0.001). This association held even after adjustmentfor age, gender, mean arterial pressure, smoking, total cholesterol,glicaemia, waist circumference, HLD cholesterol, triglycerides and eGFR(beta = 0.17; p = 0.01). The correlation between ET-1 and aortic stiffnesswas equally significant in both sexes and stronger in diabetic patients (n = 17;r = 0.60) when compared to non diabetic subjects (r = 0.26).Conclusions: Our results seem to suggest that in hypertensive men andwomen, and especially in those with diabetes, an independent relationshipexists between ET-1 plasma levels and aortic stiffness.