Body composition in children receiving recombinant human growth hormone after renal transplantation

Background. Recombinant human growth hormone (rhGH) is an anabolic hormone promoting protein synthesis in various tissues. Therefore, changes in body composition may be expected during rhGH treatment. Methods. We studied changes in body composition during two years of rhGH treatment in 21 children after at least one year with a functioning renal transplant. The mean +/- SD age was 12.9 +/- 2.5 years at the start of rhGH therapy. A whole body, dual energy X-ray absorptiometry (DEXA) exam was performed before the initiation of rhGH therapy (T0), and was repeated at one and two year intervals after initiation of the therapy (T1 and T2, respectively). Results. Lean body mass increased by a median of 0.48 SDS during the first year of treatment (P = 0.022), and the median increase during two years of therapy was 0.36 SDS (P = 0.061). On the contrary, the median fat body mass decreased by 2.17 SDS during the T0 to T1 period (P = 0.04) and by 1.99 SDS during the T0 to T2 period (P = 0.055). The index for fat body mass/lean body mass (FBM/LBM) decreased by a median of 5.3% during T0 to T1 (P < 0.001), however, a slower but still significant decrease by a median of 4.2% was noted at T2 (P < 0.05). Bone mass content did not change significantly during rhGH treatment. The medians in caloric and protein intakes were stable during rhGH treatment. Conclusion. A significant increase of lean body mass and a decrease of fat body mass was noted during rhGH therapy in children after renal transplantation.