The association between oral contraceptive use, bone mineral density and fractures in women aged 50–80 years

BackgroundThe associations between oral contraceptive (OC) use, bone mineral density (BMD) and the risk of fractures remain controversial.Study DesignA cross-sectional study of 491 women aged 50–80 years was performed. We assessed OC use and fractures by questionnaire, and BMD and vertebral deformity by dual-energy x-ray absorptiometry.ResultsEver use of OC was associated with significantly higher BMD at the total body (6%, p<.001) and spine (4%; p=.05) (but not hip) after adjustment for confounders. There was also a significant association between duration of OC use and total body and spine BMD. Use of OCs for 5–10 years was associated with reduced vertebral deformity (adjusted odds ratio 0.46, 95% confidence interval 0.22–0.94).ConclusionsOral contraceptive use and duration were associated with higher total body and spine BMD and a consistent reduction in vertebral deformities, although most associations did not reach significance.