Postmenopausal hot flushes and bone mineral density: a longitudinal study.

OBJECTIVE

To study the possible association between menopausal hot flushes and bone mineral density.

DESIGN

Observational study.

SETTING

University clinic.

POPULATION: Healthy women (n = 143) with or without hot flushes, 6-36 months postmenopausal after participating in a 6-month hormone therapy trial.

METHODS

The women prospectively recorded the number and severity of hot flushes for 2 weeks. Bone mineral density in lumbar and hip bones was measured with dual-energy X-ray absorptiometry at recruitment and reassessed in 114 women approximately 6.2 years later.

MAIN OUTCOME MEASURES: Hot flushes and bone mineral density.

RESULTS

At recruitment, hot flushes were absent in 22 women, mild in 32, moderate in 28, and severe in 61. Lumbar bone mineral densities in non-flushing women (1.130 ± 0.022 g/cm(2) ; mean ± SEM), and in those with mild (1.088 ± 0.024 g/cm(2) ), moderate (1.082 ± 0.030 g/cm(2) ) or severe (1.102 ± 0.019 g/cm(2) ) hot flushes did not differ, nor were there differences in hip bone mineral densities between the four study groups. During the follow-up, lumbar bone mineral density decreased by a mean of 0.4 ± 0.1% a year in women not using hormone therapy, and increased by 0.1 ± 0.2% a year in hormone therapy users (p = 0.019). The respective non-significant changes in left and right total hip bone mineral densities were - -0.6 ± 0.01 and -1.0 ± 0.1 for the non-users, and -0.4 ± 0.1 and -0.6 ± 0.2 for hormone therapy users. These changes in bone mineral density bore no relation to the hot flush status at baseline.

CONCLUSION

In recently menopausal women, hot flushes do not appear to determine bone mass density.