Bone mineral density before and after surgical cure of Cushing's syndrome due to adrenocortical adenoma: prospective study.

Osteoporosis is a major complication of Cushing's syndrome. The aim of the present study was to assess the chronologic effect of surgical cure on bone mineral density (BMD) in patients with Cushing's syndrome due to adrenal adenoma. BMD was examined in 28 patients before laparoscopic adrenalectomy; 17 patients with reduced BMD were then included in the longitudinal evaluation. BMD was determined using dual energy X-ray absorptiometry (DXA) before and at 3, 6, 12, 18, and 24 months after adrenalectomy. The prevalence of osteoporosis was 64% (95% confidence interval 44-81%). Preoperative BMD of the lumbar spine in the lateral projection was significantly lower than that of the femoral neck (mean+/-SD score: -3.53+/-0.75 vs. -1.54+/-0.22, p=0.003). A significant increase in BMD was observed at 3 months after surgery in the lumbar spine (p=0.0004). Improvement at both sites was maintained at 24 months after surgery. The postoperative percentage change in BMD of the lumbar spine was significantly higher than that of the femoral neck (mean+/-SD 36.7%+/-26.5% vs. 11.2%+/-12.1%, p=0.01). The change in the seven premenopausal patients was significantly higher than that in the three postmenopausal patients (p=0.0006). Surgical cure of hypercortisolism provides significant improvement in BMD in patients with Cushing's syndrome due to adrenal adenoma. The improvement is particularly apparent in the lumbar spine measured in the lateral projection. Premenopausal women are more likely to benefit from surgery in terms of secondary osteoporosis.