COURSE OF BONE-MINERAL DENSITY AFTER CURE OF CUSHINGS-SYNDROME

Both endogenous and exogenous glucocorticoid excess are well establish as causes of osteoporosis, however the reversibility of bone mass fol lowing the restauration of normal steroid levels is nor well documente d. In this longitudinal study, we mesured bone mineral density (expres sed as Z-score) by dual-photon and X-ray absorptiometry of the lumbar spine (L2-L4) in 9 patients cured of Cushing's syndrome who were follo wed for the next 48 months (16-76). Initial Z-scores ranged from -2 to -1 standard-deviation (SD) in 6 patients consistent with osteopenia, and were below -3 SD in 2 patients consistent with osteoporosis. One p atient developed lumbar spine fractures. There is no relationship betw een the severity of the Cushing's syndrome (assessed by the urinary fr ee cortisol) and initial bone reduction (inital Z-score), nor between length of Cushing's symptoms and initial bone reduction. Our data show a marked variation (+74 +/- 9 %) in bone mass in patients successfull y treated for Cushing's syndrome. Seven patients completely recovered from steroid-induced osteoporosis, one patient partially recovered but remained osteopenic. One post-menopausal women presented several lumb ar spine fractures despite successfull treatment of Gushing's syndrome . This longitudinal study confirms that if steroid-induced bone loss m ay improve substantially by cure of steroid excess even without other treatment, osteoporosis may worsen particularly in post-menopausal wom en. These results are important to take into account to properly manag e patients with steroid-induced osteoporosis.