Bone density among long-term users of medroxyprogesterone acetate as a contraceptive

The bone density (BD) of 72 women using depot-medroxyprogesterone acetate ( DMPA) for at least 1 year was compared with that of 64 women who were not u sers of hormonal contraceptives. The ED of lumbar spine, femoral neck, Ward 's triangle, and trochanter was measured by dual energy X-ray absorptiometr y (DEXA-LUNAR DPX). Estradiol (E-2) concentrations were measured by radioim munoassay (RIA). The mean age of DMPA users and nonusers was 31.8 and 31.1 years, respectively. Mean E-2 was 55.7 pg/mL for users and 149.9 pg/mL for controls (p < 0.001). The ED was significantly lower for DMPA users than fo r controls in all sites (p < 0.01). In addition, young adult T-scores in th e lumbar spine were significantly lower among DMPA users than in controls ( p < 0.01). Differences were maintained in a subsample of 47 women per group , paired by age and body mass index (BMI). Multiple regression analysis sho wed that older age, lower BMI, and longer amenorrhea were associated with l ower ED in the femoral neck, whereas lower BMI and use of DMPA were associa ted with lower BD in the lumbar spine. (C) 1998 Elsevier Science Inc. All r ights reserved.