Lack of relationship between hip and spine bone mineral density and oral contraceptive use.

The aim of this study was to examine the relationships between oral contraceptive use and bone mineral density at the hip and spine. Community based women aged 41-76 years (n = 841) were recruited from four general practices in Cambridge. Each subject completed a health questionnaire. Spine (L2-L4, n = 841) and hip (n = 833) bone mineral density were measured by dual energy X-ray absorptiometry using the Hologic QDR-1000. After adjustment for age, there was no significant difference in regional bone mineral density between ever and never users of oral contraceptives. Similar results were obtained after stratifying for potential confounding factors including menopausal status, parity, smoking, hormone replacement therapy use, and body mass index. There was no relationship between duration of oral contraceptive use and bone mineral density. These results suggest that there is no relationship between oral contraceptive use and bone mineral density at the hip and spine in middle-aged women.