Steroid hormone contraception and bone mineral density: a cross-sectional study in an international population (original) (raw)

2000, Obstetrics & Gynecology

Objective: To evaluate relationships between bone mineral density and use of steroid hormonal contraceptives. Methods: This was a multicenter cross-sectional study in seven centers in three regions of the developing world from April 1994 to June 1997. Women 30-34 years old attending family planning clinics, with at least 24 months of lifetime use of combined oral contraceptives (OC), depotmedroxyprogesterone acetate (DMPA), or levonorgestrel implants, or no or only short-term (less than 6 months) use of steroid hormonal contraceptives, had bone mineral density (BMD) measured at the distal radius and the midshaft of the ulna using single-photon x-ray absorptiometry. Results: In the study, 2474 women were examined. For OC use, adjusted mean BMD was significantly higher in shortterm, current users compared with women who never used hormonal contraceptives. For DMPA and levonorgestrel implants, adjusted mean BMD was statistically significantly lower in short-term current users compared with those who never used hormonal contraceptives. For all three hormonal methods, there were no significant differences in BMD between past users of hormonal contraceptives and never users, even among those who had used the methods for 4 or more years. The magnitude of changes in BMD was small and less than one standard deviation (SD) from the mean of those who never used steroid contraceptives. Conclusion: This study suggests that hormonal contraceptive use by young adult women is associated with small changes in BMD that occur early after initiation of use and are reversible. (Obstet Gynecol 2000;95:736-44 © 2000 by The American College of Obstetricians and Gynecologists.) Many factors influence bone mass and the risk of osteoporotic fracture. 1 In women, the hypoestrogenic state is a determinant of bone mass and fracture risk. 1 Bone mass begins to increase at the time of menarche, 2 continues to increase until the late 20s to early 30s, 3 and then begins to decrease. Peak bone mass determines the risk for osteoporotic fracture. 2 The factors that influence peak bone mass are not fully understood. 2 Hormonal contraceptive use might influence bone mass. Combined oral contraceptives (OCs) have no effect or possibly protect against age-related loss of bone mass, 4 whereas the progestogen-only contraceptive depotmedroxyprogesterone acetate (DMPA) has been associated with reduced bone mass. 5-7 This study, done in a multiethnic international population, assessed bone mass according to steroid hormonal contraceptive use in women 30-34 years old. Materials and Methods This cross-sectional study was done at seven centers in three regions of the developing world