Associations of menopausal vasomotor symptoms with fracture incidence.

CONTEXT

Vasomotor symptoms (VMS) are common. Whether VMS are associated with fracture incidence or bone mineral density (BMD) levels is unknown.

OBJECTIVE

This study aimed to examine associations of baseline VMS with fracture incidence and BMD.

DESIGN

This was a prospective observational study with mean (SD) followup of 8.2 (1.7) years (1993-2005).

SETTING

Forty United States clinical centers.

PARTICIPANTS

We examined data from Women's Health Initiative Clinical Trial participants (n = 23 573) age 50-79 years not using menopausal hormone therapy, and 4,867 participants of the BMD sub-study.

INTERVENTIONS

None.

MAIN OUTCOME MEASURES

We measured baseline VMS, incident adjudicated fractures, and BMD (baseline, annual visits 1, 3, 6, and 9).

RESULTS

After adjustment for baseline age, body mass index, race/ethnicity, smoking, and education, the hazard ratio for hip fracture among women with baseline moderate/severe VMS (vs no VMS) was 1.78 (95% confidence interval [CI], 1.20-2.64; P = .01). There was no association between VMS and vertebral fracture. VMS severity was inversely associated with BMD during followup (P = .004 for femoral neck, P = .045 for lumbar spine). In repeated measures models, compared with women who reported no VMS, women with moderate/severe VMS had 0.015 g/cm(2) lower femoral neck BMD (95% CI, -0.025--0.005) and 0.016 g/cm(2) lower lumbar spine BMD (95% CI, -0.032--0.004).

CONCLUSIONS

Women with moderate/severe VMS have lower BMD and increased hip fracture rates. Elucidation of the biological mechanisms underlying these associations may inform the design of preventive strategies for at-risk women prior to occurrence of fracture.