Effects of estradiol with and without testosterone on body composition andrelationships with lipids in postmenopausal women

Objective: The cardioprotective effects of postmenopausal estrogen replacem ent therapy are mediated by several mechanisms, including favorable effects on lipids and lipoproteins. The extent to which the latter reflects modifi cation of body fat distribution by sex steroids is not known, Hence, we inv estigated the relationships between changes in lipids and measures of body composition in postmenopausal women who were administered estrogen therapy with and without testosterone. Design: We randomized 33 postmenopausal women to treatment with either estr adiol 50 mg (E) alone or estradiol 50 mg plus testosterone 50 mg implants ( E&T) administered every 3 months for 2 years in conjunction with cyclic ora l progestins for women with an intact uterus. Results: Both therapies were associated with sustained reductions in total cholesterol and low-density lipoprotein (LDL) cholesterol, In women who rec eived E but not E&T, hip (p < 0.001) and abdominal circumferences p < 0.05) and fat mass,fat-free mass (FM:FFM) ratio over the abdomen (p < 0.05) decl ined. E&T but not E resulted in increased FFM (p < 0.001) and a reduced FM: FFM ratio (p < 0.05), For E but not E&T, the decrease in LDL cholesterol wa s significantly related to changes in total and compartmental body fat and to change in the FM:FFM ratio (p < 0.05). Conclusion: Estrogen replacement has effects on body fat distribution in po stmenopausal women that are associated with improved lipid parameters. Addi tion of parenteral testosterone does not negate the favorable effects of es trogen on LDL cholesterol levels but may attenuate the reduction in central ized body fat achieved with E implants.