EFFECTS OF RALOXIFENE ON BONE-MINERAL DENSITY, SERUM-CHOLESTEROL CONCENTRATIONS, AND UTERINE ENDOMETRIUM IN POSTMENOPAUSAL WOMEN

Background Long-term estrogen therapy can reduce the risk of osteoporo tic fracture and cardiovascular disease in postmenopausal women. At pr esent, however, these beneficial effects are not separable from undesi rable stimulation of breast and endometrial tissues. Methods We studie d the effect of raloxifene, a non-steroidal benzothiophene, on bone mi neral density, serum lipid concentrations, and endometrial thickness i n 601 postmenopausal women. The women were randomly assigned to receiv e 30, 60, or 150 mg of raloxifene or placebo daily for 24 months. Resu lts The women receiving each dose of raloxifene had significant increa ses from base-line values in bone mineral density of the lumbar spine, hip, and total body, whereas those receiving placebo had decreases in bone mineral density. For example, at 24 months, the mean (+/-SE) dif ference in the change in bone mineral density between the women receiv ing 60 mg of raloxifene per day and those receiving placebo was 2.4+/- 0.4 percent for the lumbar spine, 2.4+/-0.4 percent for the total hip, and 2.0+/-0.4 percent for the total body (P<0.001 for all comparisons ). Serum concentrations of total cholesterol and low-density lipoprote in cholesterol decreased in all the raloxifene groups, whereas serum c oncentrations of high-density lipoprotein cholesterol and triglyceride s did not change. Endometrial thickness was similar in the raloxifene and placebo groups at all times during the study. The proportion of wo men receiving raloxifene who reported hot flashes or vaginal bleeding was not different from that of the women receiving placebo. Conclusion s Daily therapy with raloxifene increases bone mineral density, lowers serum concentrations of total and low-density lipoprotein cholesterol , and does not stimulate the endometrium. (C) 1997, Massachusetts Medi cal Society.