The relative effect of endogenous estradiol and androgens on menopausal bone loss: a longitudinal study.

The aim of this study was to assess the relative strength of the association of endogenous estradiol and androgens with bone loss at the lumbar spine and femoral neck during the menopausal transition. Of the 159 participants, the mean time between the first and final measures for the whole group was 39 months and at the time of the final measures 49% of the participants had become postmenopausal. The mean percentage change/year in lumbar spine BMD was –0.9% (95% CI, –1.1 to –0.6) and at the femoral neck, –0.5% (95% CI, –0.7 to –0.2). A highly significant association with estradiol at the final time point was found, whereas the contribution of estradiol at baseline was negligible. The variance explained by estradiol levels was 19% and 11% for change in BMD at the LS and FN, respectively. Endogenous estradiol was the only hormone among those investigated to have a significant effect on bone mineral density during the menopausal transition