WHOLE-BODY AND REGIONAL SOFT-TISSUE CHANGES IN GROWTH-HORMONE DEFICIENT ADULTS AFTER ONE-YEAR OF GROWTH-HORMONE TREATMENT - A DOUBLE-BLIND,RANDOMIZED, PLACEBO-CONTROLLED STUDY

OBJECTIVE Adults with GH deficiency (GHD) exhibit changes in body comp osition. Studies of the effects of GH substitution on body composition have been shortterm or not adequately controlled, The purpose of this study was to evaluate the long-term effects of GH on soft tissue usin g dual-energy X-ray absorptiometry (DEXA), This technique enables asse ssment of whole body as well as regional soft tissue composition. DESI GN A double-blind, randomized, placebo-controlled study in patients wi th acquired GHD. The therapeutic regime consisted of biosynthetic huma n GH (2.0 IU/m(2) per day) or placebo, given as a daily subcutaneous i njection at 2000 h for 12 months. PATIENTS Twenty-nine patients with a cquired GHD (GH < 10 mu g/l (< 20 mull) following standard provocative tests) in whom additional hormone replacement was maintained. MEASURE MENTS Soft tissue determinations by DEXA scan, height, weight, foot vo lume and finger circumference were recorded together with serum IGF-I at baseline and after 12 months. RESULTS Twelve months of GH therapy i nduced a total fat mass (FM) reduction of (mean +/- SEM) 4.88 +/- 0.58 kg (P < 0.002) (n = 13) corresponding to 21.5% of the total FM. The r eduction in fat was most marked in the trunk, i.e. 3.07 +/- 0.29 kg (P < 0.002) corresponding to 61% of the total FM reduction. Total lean s oft tissue mass (LSTM) increased by 3.31 +/- 0.81 kg (P < 0.001), Regi onal changes for arm and leg in the GH group amounted to 0.32 +/- 0.08 kg (P < 0.002) and 0.71 +/- 0.14 kg (P < 0.002), respectively, withou t accompanying significant changes in truncal LSTM between the groups. The foot volume was increased by 55.8 +/- 15.7 ml (P < 0.007) and the finger circumference by 2.67 +/- 0.5 mm (P < 0.005) on active treatme nt with no significant changes in the placebo group. CONCLUSIONS Twelv e months of GH therapy induced marked changes in soft tissue; fat mass was reduced, particularly in the trunk (61% of total fat mass reducti on) whereas lean soft tissue mass increased more in the extremities. T he data imply that GH-induced changes in body composition are maintain ed with long-term therapy.