Body Composition and Tissue Distributions in Growth Hormone Deficient Adults Before and After Growth Hormone Treatment

Abstract
This study examines short and long‐term effects of recombinant human growth hormone (rhGH) on body composition and regional tissue distributions by using a multicompartment technique based on computed tomography. Part I includes nine subjects aged 46 ± 9 years with adult onset GH deficiency who were examined before and in the end of 6 months treatment with rhGH (0.4 U. kg−1. week−1) in a double‐blind crossover trial. Part II is an ongoing open trial including seven of the males in part I. They were treated with rhGH (0.25 U. kg−1. week−1) over an additional period of 24 months. Adipose tissue (AT) was reduced by 4.7 kg (p<0.01) while the muscle plus skin compartment (M) and visceral organs (V) were increased by 2.4 (p<0.05) and 0.7 kg (p<0.01), respectively, over 6 months of treatment with a high rhGH dose. A preferential lipid mobilization occurred in the visceral and subcutaneous trunk depots resulting in a changed AT distribution. Muscles of legs and arms increased while the increase of trunk muscles did not reach significance. The body composition changes were maintained over 2 years additional treatment. The preferential loss in visceral AT was further pronounced while other changes in tissue distributions observed during the first 6 months tended to be reversed on the lower rhGH dosage. It is concluded that growth hormone has profound and discordant effects on AT, M and V and with associated changes in tissue distributions. The beneficial effects on body composition seen in short‐term treatment is preserved throughout an additional 24 months period of treatment.