[Effect of GnRH analogues on bone density in the vertebral column and the femur]

The objective of this study was to evaluate the effect on vertebral and femural bone density of the gonadotropin-releasing hormone (GnRH) analog administration. The changes in mineral bone density after 6 months discontinuation of the GnRH analog treatment were also measured. Forty-three premenopausal women with regular cycles and suffering from uterine myomatosis have been selected for the study. Twenty-eight women (group A) were treated with Goserelin 3.2 mg given as a depot every 28 days for 6 months. Fifteen women were treated with 10 mg of medroxyprogesterone acetate (MPA) from day 16 to day 25 of each month for 6 months. Vertebral and femural bone density was measured (by Hologic QDR-X 1000) just before the start of the study, at 6 months of treatment and at 12 months (after 6 months of discontinuation treatment). Significant loss of vertebral bone density was demonstrated in women treated with GnRH analog. After six months of treatment discontinuation bone mineral density did not recover the pretreatment values. Bone femural density showed a not significant decrease in the GnRH analog group. In our experience, the treatment with GnRH analog in premenopausal women induces a reduction in lumbar bone density that is not reversible after the treatment withdrawal; for this reason it would be safe to add at the GnRH analog a therapy which can prevent the bone loss.