CONTINUOUS COMBINED ESTROGEN-PROGESTIN HORMONE REPLACEMENT THERAPY

Women entering menopause should be informed of the benefits and risks of hormone replacement therapy and of the variety of regimens available. One option, a continuous combined regimen of conjugated equine estrogen 0.625 mg and medroxyprogesterone acetate 2.5 mg, maintains the beneficial effects of estrogen on cardiovascular risk factors, although its effects on high-density lipoprotein cholesterol levels are less pronounced than with estrogen alone. The addition of progestin does not affect carbohydrate metabolism except for a slight decline in glucose tolerance. Blood coagulation factors and blood pressure showed no clinically significant changes different from those resulting from unopposed estrogen. Bone mineral density is increased more with the continuous combined regimen than with a cyclical regimen of the same hormones. The incidence of endometrial hyperplasia is substantially less than that observed with unopposed estrogen. The overall frequency of irregular bleeding is lower than with estrogen alone and diminishes with continuation of therapy, whereas the incidence of amenorrhea increases from 52.1% to 75.1% between cycles 2 and 11. Epidemiologic evidence linking any hormonal therapy with breast cancer remains inconsistent, possibly because the risk, if any, is small. The relative risk of breast cancer for the continuous regimen has not been extensively studied in large-scale studies.