THE EFFECT OF LONG-TERM PREDNISONE TREATMENT ON GROWTH-HORMONE AND INSULIN-LIKE GROWTH-FACTOR-I

Due to a lack of longitudinal data the precise effect of long-term cor ticosteroid treatment on serum levels of the anabolic hormones Growth Hormone (GH) and Insulin-like Growth Factor-1 (IGF-I) is unknown. Ther efore, we prospectively followed GH and IGF-1 levels over a six month period in 18 euthyroid patients with Graves' ophthalmopathy. Ten patie nts were treated with a three month course of prednisone; eight patien ts receiving retrobulbar irradiation sewed as controls. Baseline serum GH and IGF-1 levels were similar in both groups. Whereas no changes w ere seen in controls, prednisone induced a rapid increase in serum IGF -1 levels, which was sustained during the entire treatment period: 18. 2+/-5.2 at baseline vs 24.1+/-6.7 nmol/l after 12 weeks of treatment ( p<0.001). After discontinuation of prednisone IGF-1 returned to baseli ne levels. Basal GH levels were frequently undetectable, but during tr eatment GH values were lower in the prednisone group (median of detect able values 4.0 mU/L [range 2.0-26.0]) than in controls (11.8 [2.8-44. 0]; p<0.01). In conclusion, long-term prednisone treatment is associat ed with suppressed GH levels and with an increase in total IGF-I level s. This suggests that prednisone can disrupt the GH/IGF1 axis. (C) 199 6, Editrice Kurtis