Anthropometric characteristics and risk of uterine leiomyoma.

BACKGROUND

The etiology of uterine leiomyoma (or fibroids) is poorly understood. Sex steroid hormones and growth factors have been hypothesized to play a role in their development, and anthropometric characteristics may influence uterine leiomyoma risk.

METHODS

We analyzed prospectively-collected data from the Nurses' Health Study II, a cohort of 116,609 female registered nurses age 25 to 42 years at baseline. Incidence of uterine leiomyoma and anthropometric characteristics were assessed every 2 years. We calculated hazard ratios and 95% confidence intervals adjusted for known and suspected risk factors for uterine leiomyoma.

RESULTS

Uterine leiomyomas were associated with current body mass index, change in weight since age 18, and waist-to-hip ratio. However, there was little evidence of their association with body mass index at age 18, childhood or adolescent body size, or adult height.

CONCLUSION

Body mass and weight gain in adulthood may increase the risk of uterine leiomyoma, but body mass in early life does not.