Long-term assessment of forearm bone mineral density in postmenopausal former users of depot medroxyprogesterone acetate.

BACKGROUND

There are many controversies on the association between depot medroxyprogesterone acetate (DMPA) and bone mineral density (BMD). This study reevaluated BMD in postmenopausal women who had used DMPA as a contraceptive until they reached menopause and compared them with non-users. BMD had previously been measured in these women either at 1 year or 2-3 years after menopause and was reassessed in these women 2 years later. Therefore, comparisons were made between the first and third years and between the second to third and fourth to fifth years after menopause.

STUDY DESIGN

BMD was reevaluated using dual-energy X-ray absorptiometry at two parts of the non-dominant forearm up to 5 years after menopause in 79 women between 46 and 61 years old: 24 former DMPA users and 55 former copper intrauterine device (IUD) users.

RESULTS

With respect to the former DMPA users, only the BMD measurement at the distal radius in the first year (mean±SEM, 0.425±0.017) was significantly higher than the third-year measurement (0.406±0.017) (p<.015). No significant differences were found at the ultradistal radius. There were no significant differences between the groups of former DMPA and IUD users with respect to BMD measurements either at the distal radius or at the ultradistal radius. There was a direct relationship between higher body mass index (kg/m(2)) and higher BMD at the distal radius between the first and third years. At the ultradistal radius, there was an indirect relationship between older age and lower BMD between the first and third years in both groups.

CONCLUSIONS

No statistically significant differences were found in forearm BMD measurements between postmenopausal women who had been long-term users of DMPA and those who had been long-term users of an IUD until menopause. Evaluation of BMD after the menopause showed slightly higher values in former DMPA users compared with non-users.