Serum sex steroid levels and longitudinal changes in bone density in relation to the final menstrual period.

Abstract

The associations of serum sex steroid and FSH levels with change of bone mineral density (BMD) across the complete menopausal transition are incompletely understood. The objective of the study was to examine the associations of annual serum levels of FSH, estradiol (E2), T, and SHBG with the rates of bone loss in 3 phases: pretransmenopausal [baseline to 1 year before the final menstrual period (FMP)], transmenopausal (1 year before to 2 years after the FMP), later postmenopausal (≥ 2 years after the FMP). The design of the study was a repeated-measures, mixed-effects regression. This was a community-based observational study, with a 10-year follow-up. A total of 720 participants of the Study of Women's Health Across the Nation Bone Study participated in the study. Annualized lumbar spine (LS) and femoral neck (FN) BMD decline was measured. The mean annual change in BMD was slowest in pretransmenopause (0.27%/year in FN) and fastest in transmenopause (2.16%/year in LS). In the pretransmenopausal phase, for every doubling of FSH level, LS BMD change was faster by -0.32%/year (P < .0001). In the transmenopausal phase, for every doubling of FSH level, LS BMD change was -0.35%/year faster (P < .0001); for every doubling of SHBG level, LS BMD change was -0.36%/year faster (P < .0001). In the later postmenopausal phase, for each doubling of the E2 level, the LS BMD change was slower by +0.26%/year (P = .049); for each SHBG doubling, the LS BMD change was 0.21%/year slower (P = .048). The FN associations were weaker and inconsistent. Higher E2 levels and lower FSH levels were associated with lower rates of LS bone loss in some but not all menopausal transition phases.