Combined hormone replacement therapy improves endothelial function in healthy postmenopausal women

Objectives. Large scale epidemiological studies suggest that hormone replac ement therapy (HRT) reduces cardiovascular events in postmenopausal women. Improvement in endothelial function may contribute to this protective effec t. Design. In a prospective. double blind study, 61 healthy postmenopausal wom en were randomized to receive either oral continuous combined HRT [oestradi ol 2 mg and norethisterone acetate (NETA) 1 mg per day] or placebo. Endothe lial function, assessed by flow-mediated vasodilation (FMD) of the brachial artery and expression of soluble endothelial cell adhesion molecules (CAM) were determined before, after 3 and 6 months of therapy. Results. The FMD was significantly improved in women on combined HRT (from 5.97% to 10.94% after 3 months and to 10.58% after 6 months; both P < 0.01 versus baseline values) and did not change in the placebo group (6.92% at b aseline, 5.86% after 3 and 6.26% after 6 months). After 3 months of combine d HRT, significant decreases of 24.6% for E-selectin and 13.9% for intercel lular adhesion molecule-1 (ICAM-1) were observed (both P < 0.01 versus base line values) and were sustained after 6 months of therapy, whilst no differ ences emerged in the placebo group. Conclusions. Oestradiol and norethisterone acetate improve endothelial func tion by both enhancing FMD and reducing the levels of soluble E-selectin an d ICAM-1 in healthy postmenopausal women.