Hot flushes, bone mineral density, and fractures in older postmenopausal women.

OBJECTIVE: To assess whether greater severity of hot flushes is associated with bone loss or fracture risk in older postmenopausal women.
METHODS: This study is a secondary analysis of 3,167 postmenopausal women in the Multiple Outcomes of Raloxifene Evaluation trial. Baseline hot flush severity was assessed by self-report. Femoral neck and lumbar spine bone density was assessed by dual-energy X-ray absorptiometry. Vertebral and nonvertebral fractures were determined radiographically and by interview. Baseline bone density, 3-year bone loss, baseline prevalent fractures, and 3-year fracture incidence were examined in women with varying hot flush severity.
RESULTS: After adjusting for other characteristics, greater severity of hot flushes was associated with higher, rather than lower, baseline bone density (adjusted mean femoral neck bone density=0.633, 95% confidence interval [CI] 0.614-0.652 g/cm2, versus 0.611, 95% CI 0.608-0.613 g/cm2 for women with "severe" versus "minimal" hot flushes). Women with more severe hot flushes were less likely to have a baseline fracture (odds ratio 0.64, 95% CI 0.48-0.84, for vertebral fracture in women with moderate or severe versus minimal hot flushes). The 3-year annualized change in bone density did not differ among women with varying hot flush severity (P>.40 for all). Hot flush severity was not related to incident vertebral or nonvertebral fracture (P>.05 for all).
CONCLUSION: Among osteoporotic women who are 5 or more years postmenopausal, greater severity of persistent hot flushes is not associated with progressive bone loss or risk of fracture, despite previous research linking hot flushes to bone loss during early menopause. LEVEL OF EVIDENCE: II.