DOES SUBLINGUAL 17-BETA-ESTRADIOL HAVE ANY EFFECTS ON EXERCISE CAPACITY AND MYOCARDIAL-ISCHEMIA IN POSTMENOPAUSAL WOMEN WITH STABLE CORONARY-ARTERY DISEASE

Background A variety of vascular effects have been ascribed to 17 beta -oestradiol. These effects may partially explain the reduced incidence of cardiovascular disease found in post-menopausal women on oestrogen replacement therapy. Objectives To evaluate the effects of 2 mg subli ngual 17 beta-oestradiol on exercise capacity, exercise-induced myocar dial ischaemia and circulating levels of endothelin-1 in post-menopaus al women with stable coronary artery disease. Methods Twelve post-meno pausal women, mean age 61 (range 52-72) years, with angiographically v erified significant coronary artery disease, were randomly assigned to 2 mg of sublingual 17 beta-oestradiol, 2.5 mg of buccal nitroglycerin e and to placebo in a double-blind cross-over study design with at lea st 2 days between each of the study arms. Antianginal medications, wit h the exception of betablockers, were discontinued before investigatio n. All study patients underwent a maximal bicycle exercise test 30 min after drug intake. Blood was withdrawn immediately before and up to 8 h after medication for analyses of circulating levels of oestradiol a nd endothelin-1. Results The mean serum levels of oestradiol increased from a control level of 72 +/- 28 pmol . l(-1) to 3557 +/- 1631 pmol . l(-1)' after 30 min and to 5028 +/- 3971 pmol . l(-1) after 60 min w ith a gradual decline thereafter. Sublingual 17 beta-oestradiol did no t induce any improvement in exercise duration when compared with nitro glycerin and placebo (500 +/- 112 s, 505 +/- 107 s, 498 +/- 157 s), an d did not influence time to onset of ST-segment depression (358 +/- 89 s, 436 +/- 93 s: 384 +/- 116 s). The plasma levels of endothelin-l di d not change after administration of 17 beta-oestradiol, nitroglycerin or placebo. Conclusions No effects on exercise capacity, exercise-ind uced acute ischaemia, or plasma levels of endothelin-1 were found afte r a single dose of 2 mg 17 beta-oestradiol in post-menopausal women wi th documented coronary artery disease.