Sex steroids, bone turnover and bone mineral density in pre-, peri-, and postmenopausal women

To examine 1) the relationships between endogenous androgens and bone mineral density (BMD), 2) the relationships between sex-hormone binding globulin (SHBG) and BMD, and 3) the associations of endogenous androgens and SHBG with biochemical markers of bone turnover, a cross-sectional study was carried out in 88 healthy pre-, peri-, and postmenopausal women aged 35 to 74. Measurements of BMD(s) at the ultradistal radius and ulna, and the distal radius (using DEXA), estrogens, androgens, deoxypyridinoline (D-Pyr) and intact bone gla protein (I-BGP) were performed. In the multivariate regression models testosterone (T) was positively correlated with BMD at the ultradistal radius and ulna in perimenopausal women, and was positively correlated with BMD at the ultradistal radius and ulna, and the distal radius in postmenopausal women. T was positively associated with I-BGP in premenopausal women (r = 0.65, p < 0.01), and negatively associated with D-Pyr in pre- (r = -0.53, p < 0.05) and postmenopausal women (r = -0.49, p < 0.001). On the other hand, SHBG was negatively correlated with BMD at die ultradistal radius and ulna, and die distal radius in pre- and postmenopausal women in the models. SHBG was positively related to D-Pyr in pre(r = 0.57, p < 0.05) and postmenopausal women (r = 0.41, p < 0.01), and negatively related to I-BGP in postmenopausal women (r = -0.38, p < 0.01). These findings suggest that endogenous androgens may exert positive influences on BMD, and that SHBG may have negative effects on BMD.