GLUCOCORTICOID REPLACEMENT THERAPY - ARE PATIENTS OVER TREATED AND DOES IT MATTER

BACKGROUND AND OBJECTIVES Adequate assessment of patients on glucocort icoid replacement therapy is of great importance to avoid the conseque nces of under or over treatment, but no simple test is available for t his. The aims of this study were (1) to assess adequacy of glucocortic oid replacement in hypoadrenal patients, (2) to correlate serum cortis ol levels (cortisol day curve) with 24-hour urine free cortisol excret ion and (3) to assess the impact of glucocorticoid dose optimization o n markers of bone formation and bone resorption. DESIGN Cross-sectiona l study of current replacement therapy and a prospective study of the effect of dose alteration on bone turnover markers. PATIENTS Thirty-tw o consecutive patients on replacement glucocorticoid therapy (12 Addis on's disease, 20 hypopituitarism) from a University teaching hospital out-patient department. MEASUREMENTS Serum and urinary cortisol, osteo calcin, N-telopeptide of type I collagen (NTX) and bone mineral densit y, RESULTS 28/32 (88%) patients required a change of therapy; 24/32 (7 5%) a total reduction in dose, 18/32 (56%) a change in replacement the rapy regimen or drug and 14/32 (44%) both changes. The mean daily dose of hydrocortisone was reduced from 29.5+/-1.2 to 20.8+/-1.0 mg. A sig nificant correlation was found between peak cortisol and 24-hour urine free cortisol/creatinine (Spearman correlation r=0.60, P<0.0001; n=51 ). Following hydrocortisone dose reduction, median osteocalcin increas ed from 16.7 mu g/l (range 8.2-65.7) to 19.9 mu g/l (8.2-56.3); P<0.01 , with no change in the NTX/creatinine ratio. CONCLUSIONS A high propo rtion of patients on conventional corticosteroid replacement therapy a re over treated or on inappropriate replacement regimens. To reduce th e long term risk of osteoporosis, corticosteroid replacement therapy s hould be individually assessed and over replacement avoided.