Acute administration of 17beta-estradiol improves endothelium-dependent vasodilation in postmenopausal women

Estrogen's effect on endothelial function in postmenopausal women with mild hypertension but no other cardiovascular risk factors remains unclear. This study investigated the effect of an acutely administered therapeutic/low dose of 17beta-estradiol on vasodilation in this patient population.

Forearm blood flow (FBF) was measured in seven white, hypertensive (blood pressure 144 +/- 8/93 +/- 5 mmHg), postmenopausal (mean age: 54.4 +/- 5 years) women at baseline and during the intra-brachial infusion of increasing doses of acetylcholine (ACh; 0.75, 5, and 15 microg/100 mL tissue/min) and sodium nitroprusside (NP; 1, 2, and 4 microg/100 mL tissue/min). These measurements were obtained both before and after the sublingual administration of 17beta-estradiol. Eight normotensive women (blood pressure 115 +/- 8/76 +/- 5 mmHg) with otherwise similar characteristics served as controls (mean age: 55.8 +/- 5 years). Exclusion criteria included medications or any condition that could alter endothelial function.

Before estradiol administration, FBF values at baseline and after all doses of ACh and NP were similar between groups. Acutely administered 17beta-estradiol significantly improved the FBF response to ACh in both the normotensive (maximal response: 17.6 +/- 5 versus 22.5 +/- 7 mL/min/100 mL) and hypertensive (11 +/- 4 versus 16 +/- 6; 12 +/- 4 versus 17 +/- 5 and 14 +/- 3 versus 20 +/- 7 mL/min/100 mL) groups. It also altered the NP dose-response curve in the both groups.

17beta-estradiol improved vasodilatory responses in mildly hypertensive postmenopausal women without other risk factors for cardiovascular disease.