ASSOCIATION BETWEEN INCREASED PLASMA-LEVELS OF ALDOSTERONE AND DECREASED SYSTEMIC ARTERIAL COMPLIANCE IN SUBJECTS WITH ESSENTIAL-HYPERTENSION

We previously observed that, in subjects with essential hypertension, acute ouabain constricts the brachial artery diameter in the presence of spironolactone treatment, a finding that is not observed in the abs ence of aldosterone antagonist and therefore suggests a specific effec t of aldosterone on the arterial wall. To evaluate whether aldosterone excess may contribute to modulate arterial function, we investigated 56 patients with sustained essential hypertension in comparison with 3 6 normotensive controls. Systemic arterial compliance was measured fro m intraarterial blood pressure and cardiac output measurements using a classical Windkessel model to determine the elasticity of the proxima l arterial tree. Radial artery compliance was determined using a previ ously described echo tracking technique. In hypertensive, but not in n ormotensive, subjects, systemic arterial compliance was strongly and n egatively correlated with plasma aldosterone. The correlation was obse rved even after adjustment for age and blood pressure. Plasma potassiu m and renin activity did not interfere in the correlation. Acute admin istration of diltiazem did not change systemic compliance but signific antly decreased plasma aldosterone, suggesting that, in the presence o f calcium blockade, the same compliance was achieved for a lower plasm a aldosterone level. Taken together, these findings strongly suggest t hat significant interactions exist between aldosterone and central con duit arteries and that aldosterone might modulate arterial function in subjects with essential hypertension. (C) 1997 American Journal of Hy pertension, Ltd.