Cortisol secretion, bone health, and bone loss: a cross-sectional and prospective study in normal non-osteoporotic women in the early postmenopausal period.

Objective: The aim of the study was to evaluate the relationship between cortisol secretion, bone health, and bone loss in a cohort of normal women in the early postmenopausal period.

Methods: We measured lumbar and hip bone mineral density (BMD) by dual-energy X-ray absorptiometry (DXA) and heel ultrasound parameters in 82 healthy, nonosteoporotic (lumbar T-score ≥-2.0) women (median age 52.5 years, range 42-61). These women were examined in two sessions, 1 year apart, in the early postmenopausal period (onset of menopause between 6 and 60 months). Parameters of the hypothalamic-pituitary-adrenal (HPA) axis function were morning serum cortisol, morning and midnight salivary cortisol, 24-h urinary free cortisol (UFC), serum cortisol after 0.5 and 1 mg overnight dexamethasone, and DHEA-S.

Results: In multiple regression analyses, the following significant inverse correlations were found: i) lumbar BMD and either 24-h UFC (P<0.005) or morning serum cortisol (P<0.05), ii) total femur and femoral neck BMD with morning serum cortisol (P=0.05 and P<0.05), and iii) heel ultrasound stiffness index and midnight salivary cortisol (P<0.005). The annual rate of change in lumbar and femoral BMD did not correlate with any of the above-mentioned hormonal variables. No difference was found in the parameters of HPA axis function in slow (loss of BMD <1%) vs fast (loss of BMD ≥3%) bone losers.

Conclusions: HPA axis may contribute to postmenopausal bone health, but differences in cortisol secretion do not influence the differential rate of bone loss between slow and fast bone losers in the early postmenopausal period, at least in healthy women.