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 composition. 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 using dual-energy X-ray absorptiometry (DEXA), This technique enables assessment of whole body as well as regional soft tissue composition. DESIGN A double-blind, randomized, placebo-controlled study in patients with acquired GHD. The therapeutic regime consisted of biosynthetic human GH (2.0 IU/m(2) per day) or placebo, given as a daily subcutaneous injection at 2000 h for 12 months. PATIENTS Twenty-nine patients with acquired GHD (GH < 10 mu g/l (< 20 mull) following standard provocative tests) in whom additional hormone replacement was maintained. MEASUREMENTS Soft tissue determinations by DEXA scan, height, weight, foot volume and finger circumference were recorded together with serum IGF-I at baseline and after 12 months. RESULTS Twelve months of GH therapy induced 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 reduction 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 soft tissue mass (LSTM) increased by 3.31 +/- 0.81 kg (P < 0.001), Regional 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, without 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 treatment with no significant changes in the placebo group. CONCLUSIONS Twelve months of GH therapy induced marked changes in soft tissue; fat mass was reduced, particularly in the trunk (61% of total fat mass reduction) whereas lean soft tissue mass increased more in the extremities. The data imply that GH-induced changes in body composition are maintained with long-term therapy.