Bone density and turnover in Addison's disease: effect of glucocorticoid treatment

Osteoporosis is a well-known side-effect of chronic treatment with glucocorticoids. We have studied vertebral bone mineral density (BMD) and biochemical markers of bone metabolism in 30 patients diagnosed of Addison's disease (AD) to determine the effect of long-term replacement treatment with hydrocortisone (30 mg/day) or prednisone (7.5 mg/day). Lumbar bone mineral density was measured with dual energy X-ray absorptiometry in L-1-4 in two occasions, separated by 12 months. BMD in premenopausal women and men with AD was similar to healthy controls and postmenopausal women had slightly lower results. Rate of change of bone density followed up over a period of 12 months was -0.82%. Bone loss was not influenced by duration or type of steroid treatment. Biochemical parameters, serum calcium, alkaline phosphatase, osteocalcin, procollagen type I, PTH and 25(OH)vitamin D were within normal limits. Our results show that in patients with AD, after replacement with low doses of glucocorticoids there is no significative trabecular bone loss neither modifications in bone formation markers.