To examine the impact of amenorrhea on bone mineral density in women of reproductive age, bone mineral density in the lumbar spine (L2-L4) was measured by Dual-energy X-ray absorptiometry in 43 amenorrheal women. There was a significant lower bone mineral density in this test group (0.917 +/- 0.121 g/cm2) than in a normally menstruating control group (1.032 +/- 0.095 g/cm2). In premature ovarian failure, we found lower bone mineral density (0.863 +/- 0.112 g/cm2) than in any other subclass. Seven women with premature ovarian failure received cyclic hormone replacement therapy for 12 months (day 1-28, 0.625 mg conjugated estrogen, and on days 14-28, 5 mg medroxyprogesterone, followed by a seven-day pause). After 12 months, bone mineral density had increased significantly (p < 0.05) compared to the initial bone mineral density. We conclude that amenorrhea is a cause of bone loss in young women and that estrogen therapy is effective in preventing bone loss.
