Correction of arterial structure and endothelial dysfunction in human essential hypertension by the angiotensin receptor antagonist losartan

Structural and functional alterations of the vasculature may contribute to complications of hypertension. Because angiotensin II may be pivotal in some of these vascular abnormalities, we tested the hypothesis that the angiotensin type 1 (AT(1)) receptor antagonist losartan, in contrast to the beta-blocker atenolol, would correct resistance artery abnormalities in patients with essential hypertension. Nineteen untreated patients with mild essential hypertension (47+/-2 years, range 30 to 65 years; 57% male) were randomly assigned in double-blind fashion to losartan or atenolol treatment for 1 year. Nine age/sex-matched normotensive subjects were also studied. Both treatments reduced blood pressure to a comparable degree (losartan, from 149+/-4.1/101+/-1.6 to 128+/-3.6/86+/-2.2 mm Hg, P