@article {1266, title = {Higher serum free testosterone concentration in older women is associated with greater bone mineral density, lean body mass, and total fat mass: the cardiovascular health study.}, journal = {J Clin Endocrinol Metab}, volume = {96}, year = {2011}, month = {2011 Apr}, pages = {989-96}, abstract = {

CONTEXT: The physiological importance of endogenous testosterone (T) in older women is poorly understood.

OBJECTIVE: The aim of the study was to determine the association of higher total and free T levels with bone mineral density (BMD), lean body mass, and fat mass in elderly women.

DESIGN: Total and free T were measured using sensitive assays in 232 community-dwelling women aged 67-94 yr who were enrolled in the Cardiovascular Health Study and had dual-energy x-ray absorptiometry scans. Cross-sectional analyses were performed to examine associations between total and free T and BMD and body composition.

RESULTS: In adjusted models, total T was directly associated with BMD at the lumbar spine (P = 0.04) and hip (P = 0.001), but not body composition outcomes, in all women, and after excluding estrogen users and adjusting for estradiol (P = 0.04 and 0.01, respectively). Free T was positively related to hip BMD, lean body mass, and body fat (all P < 0.05), with more than 10\% differences in each outcome between women at the highest and lowest ends of the free T range, with attenuation after excluding estrogen users and adjusting for estradiol.

CONCLUSIONS: In the setting of the low estradiol levels found in older women, circulating T levels were associated with bone density. Women with higher free T levels had greater lean body mass, consistent with the anabolic effect of T, and, in contrast to men, greater fat mass. Mechanistic studies are required to determine whether a causal relationship exists between T, bone, and body composition in this population and the degree to which any T effects are estrogen-independent.

}, keywords = {Adipose Tissue, Aged, Aged, 80 and over, Body Mass Index, Bone Density, Cardiovascular Physiological Phenomena, Cohort Studies, Female, Health, Humans, Organ Size, Osmolar Concentration, Osteoporosis, Postmenopausal, Testosterone, Thinness, Up-Regulation}, issn = {1945-7197}, doi = {10.1210/jc.2010-0926}, author = {Rariy, Chevon M and Ratcliffe, Sarah J and Weinstein, Rachel and Bhasin, Shalender and Blackman, Marc R and Cauley, Jane A and Robbins, John and Zmuda, Joseph M and Harris, Tamara B and Cappola, Anne R} }