Biphasic effects of hormone treatment on risk of cardiovascular disease —

"Regularly ovulating women of reproductive age are significantly protected against CVD compared with men, but CVD increases within 10 years of menopause to levels matching or exceeding incidence rates among men,13 suggesting that ovarian estrogen may help protect women against atherosclerosis. This observation led to the corollary hypothesis that treatment of postmenopausal women with estrogens (menopausal hormone therapy [MHT]) might prevent the postmenopausal increase in CVD rates. Yet, despite more than 30 years of research attempting to define whether and how postmenopausal estrogen replacement might protect women against CVD, the issue remains uncertain and, indeed, controversial...."