Menopause: evidence-based practice.
Menopause is a physiologic transition and is assuming an increasing importance as the demographic bulge moves through this phase. The transition takes place over several years. It is characterized by depletion of the ovarian follicles, decreasing inhibin leading to increases in follicle-stimulating hormone and loss of the menstrual cycle, accompanied by decreased estradiol production and typical symptoms. The role of hormone therapy in menopause has shifted from preventive use to a limited role in symptom management, for which it remains the most effective intervention. There is good evidence from observational and randomized trials of an increased risk of breast cancer in women on estrogen plus a progestin, compared with those on estrogen alone. There are insufficient data to be able to determine if there are clinically important differences between various progestins and progesterone with respect to breast cancer risk, nor between different regimens. Even relatively short-term exposure to unopposed estrogen will increase the risk of atypical endometrial hyperplasia or cancer; women who have their uterus should be using a progestational agent. Lifestyle changes at menopause are important and effective for preventive health. Recent evidence suggests that the discordance between epidemiologic studies with respect to cardiovascular outcomes and the Women's Health Initiative randomized controlled trial (WHI RCT) data might be attributable in large part to the older age of women enrolled in the WHI.