TOTAL AND REGIONAL BONE-MINERAL CONTENT IN WOMEN TREATED WITH GNRH AGONISTS

Changes in bone mineral content induced by GnRH agonists were investig ated by measuring total body bone mineral content (TBBM) and regional bone mineral content (BMC) (arms, legs, trunk, pelvis) and densities w ith dual energy X-ray absorptiometry in 25 premenopausal women before and after a 6-month treatment with gonadotropin-releasing hormone (GnR H) agonists. Biological markers of bone remodeling, estrogens, luteini zing hormone, and follicle-stimulating hormone were also measured. Wei ght and body mass index increased significantly after treatment (P < 0 .05), and TBBM, corrected for weight (TBBM/W), decreased (P < 0.001). The changes in BMC that we observed ranged from + 2.5% to - 6.9%. The greatest decrease in regional BMC occurred in the trunk (4.4%, P < 0.0 01), with TBBM decreasing by 2.1% (P < 0.001). No significant changes were observed in the limbs. Tartrate-resistant acid phosphatase (TRAP) increased significantly after treatment (P < 0.001) and a significant negative correlation between TRAP and TBBM (P < 0.001) and between TR AP and estradiol (P < 0.001) were observed before treatment. The lack of changes observed in the BMC of the limbs indicate that GnRH agonist s cause a preferential loss of BMC in trunk osseous structures, a situ ation similar to that of the first years of menopause.