Oral contraceptive use and bone density in adolescent and young adult women☆
Received 23 May 2009; received in revised form 4 July 2009; accepted 7 July 2009. published online 25 August 2009.
Abstract
Background
Most of the millions of oral contraceptive (OC) users are under 30 years of age and in the critical period for bone mass accrual.
Study Design
This cross-sectional study of 606 women aged 14–30 years examined both OC duration and estrogen dose and their association with bone mineral density (BMD) at the hip, spine, and whole body (dual-energy X-ray absorptiometry).
Results
Of 389 OC users and 217 nonusers enrolled, 50% were adolescents (14–18 years). Of OC users, 38% used “low-dose” OCs [<30 mcg ethinyl estradiol (EE)]. In adolescents, mean BMD differed by neither OC duration nor EE dose. However, 19- to 30-year-old women's mean BMD was lower with longer OC use for spine and whole body (p=.004 and p=.02, respectively) and lowest for >12 months of low-dose OCs for the hip, spine and whole body (p=.02, .003 and .002, respectively).
Conclusions
Prolonged use of today's OCs, particularly <30 mcg EE, may adversely impact young adult women's bone density while using these agents.
☆ This study was funded by grant 1R01-HD31165-11 (Scholes) from the National Institute for Child Health and Human Development, National Institutes of Health. Dr. Beasley is a postdoctoral fellow supported by T-32 AG027677 from the National Institute on Aging.
ABSTRACT