SPONTANEOUS REVERSIBILITY OF BONE LOSS INDUCED BY GONADOTROPIN-RELEASING-HORMONE ANALOG

Objective: To verify if a 6-month period of hypoestrogenism due to chr onic treatment with GnRH analogue (GnRH-a) causes irreversible bone lo ss in young women. Design: Controlled clinical study in volunteer wome n. Setting: Department of Obstetrics and Gynecology, University of Cag liari, Cagliari, Italy. Patients: Twenty-eight women (mean age +/- SE 81.1 +/- 0.99 years) with endometriosis diagnosed by laparoscopy and 2 5 healthy, normally cycling women of the same age (28.3 +/- 1.14 years ). Interventions: In women with endometriosis, six SC implants of the GnRH-a compound, 3.6 mg goserelin acetate depot, were administered eve ry 28 days starting within 15 days of laparoscopy. Compounds interferi ng with bone metabolism or hormonal formulations were not taken by con trol women during the entire period of the study. Main Outcome Measure : Evaluation of lumbar bone mineral density at the start of the study and 6, 12, and 30 months later. Results: At the onset of the study, lu mbar bone mineral density did not differ in women with endometriosis a nd control women. Lumbar bone mineral density values significantly dec reased after 6 months of GnRH-a treatment. This reduction was still ev ident 6 months after GnRH-a interruption. However, 24 months after tre atment withdrawal, bone mineral density reduction disappeared and bone mineral density values were completely superimposable (+/-0.4%) to th ose observed before treatment. In contrast, control. women lumbar bone mineral density values did not change during the entire period of obs ervation. Conclusions: These data suggest that GnRH-a treatment for 6 months is not associated with long-term effects on lumbar bone density .