Participants in their study received two hormone replacement therapies, each for several weeks. The women exercised on a treadmill until tests showed they were experiencing reduced blood flow to the heart. They could exercise significantly longer when natural progesterone was part of the hormone therapy. He plans to present these data in a few weeks at the American College of Cardiology's annual meeting. Reactivity-based coronary vasospasm independent of atherosclerosis in rhesus monkeys.
Medroxyprogesterone interferes with ovarian steroid protection against coronary vasospasm.
Williams, J.K., and M.R. Adams. Estrogens, progestins and coronary artery reactivity. Medroxyprogesterone acetate antagonizes inhibitory effects of conjugated equine estrogens on coronary artery atherosclerosis. Adler, T. 1994. New success with heart disease drugs.