Calcium, FSH, and the changing bones of menopause: A longitudinal look at the silent transformation

Osteoporosis poses a health risk to post-menopausal females. The menopause transition is associated with hormone fluctuations (e.g., follicle-stimulating hormone (FSH), estrogen), and other biochemical and physiological changes that contribute a decline in bone mineral density (BMD). This will investigate the relationship between biochemical and physiological markers of BMD across the menopause transition. Fifty-six middle-aged females who completed their menopause transition were included in this longitudinal sub-analysis. Participants were recruited from the Ottawa/Gatineau region. Menopause status was classified using menstrual history and FSH plasma levels. BMD and body composition were assessed using dual-energy x-ray absorptiometry (DXA). Additional measures included BMI, cardiorespiratory fitness (VO 2max ), diet calcium and Vitamin D, and biochemical markers (i.e., FSH, cortisol, calcium). Statistical analysis included repeated measures analysis of variance, linear mixed modeling, and group-based trajectory modeling to identify distinct FSH trajectory groups and their associations with BMD changes over time. Serum calcium was negatively associated with BMD at the lumbar spine [β: −0.0799, 95% confidence interval (CI): −0.139; −0.020, p = 0.009]. Further, the high FSH trajectory group experienced a greater decrease in BMD across the 5-year period, at the femur neck [β: 0.067, CI: 0.050; 0.084 vs. β: 0.035, CI: 0.021; 0.048; p = 0.003] and total body [β: 0.045, CI: 0.035; 0.055 vs. β: 0.028, CI: 0.020; 0.036; p = 0.007] than the low FSH trajectory group. Associations between serum calcium and lumbar spine BMD, and a greater BMD decline in individuals with high FSH levels were revealed. This information suggests that serum calcium and FSH should be monitored throughout the menopause transition to protect BMD. • Serum calcium was inversely associated with lumber spine bone mineral density during menopause. • High FSH trajectory predicted greater bone loss at the femur neck and total body across the menopause transition. • Declining estrogen and FSH may alter calcium regulation during menopause. • Monitoring FSH and calcium could aid early detection of osteoporosis risk.