TY - JOUR
T1 - Higher serum free testosterone concentration in older women is associated with greater bone mineral density, lean body mass, and total fat mass
T2 - The cardiovascular health study
AU - Rariy, Chevon M.
AU - Ratcliffe, Sarah J.
AU - Weinstein, Rachel
AU - Bhasin, Shalender
AU - Blackman, Marc R.
AU - Cauley, Jane A.
AU - Robbins, John
AU - Zmuda, Joseph M.
AU - Harris, Tamara B.
AU - Cappola, Anne R.
PY - 2011/4
Y1 - 2011/4
N2 - 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 withBMDat 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.
AB - 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 withBMDat 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.
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U2 - 10.1210/jc.2010-0926
DO - 10.1210/jc.2010-0926
M3 - Article
C2 - 21289255
AN - SCOPUS:79953852887
VL - 96
SP - 989
EP - 996
JO - Journal of Clinical Endocrinology and Metabolism
JF - Journal of Clinical Endocrinology and Metabolism
SN - 0021-972X
IS - 4
ER -