Body composition in children after renal transplantation

This study examines changes in body composition after renal transplantation (Tx) in 16 children who underwent dual-energy X-ray absorptiometry examination within 6 months preceding Tx; the examination was then repeated every 6 to 12 months after Tx. Body composition was analyzed with regard to whole-body bone mineral content (BMC), lean body mass (LBM), and fat body mass (FBM). Median BMC decreased from the initial value of +0.98 standard deviation scores (SDS) to -0.55 SDS during the first 3 months after Tx, and a further decrease was noted at the end of month 6 (M6; -1.34 SDS) and M12 after Tx (-1.32 SDS). Improvement was observed during the second year after Tx (P for global changes < 0.0001). LBM and FBM also changed significantly during the 2 years after Tx (P = 0.006 and P = 0.0001, respectively). LBM decreased during the first 3 months after Tx (median change, 0.71 SDS) and remained less than 0 SDS in all but 4 patients. Median LBM did not decrease to less than -1 SDS during the entire study period. Conversely, median FBM increased by a median of 3.73 SDS during the first 3 months and remained elevated during the first 12 months after Tx, with a subsequent decrease at 2 years after Tx. No significant correlation was found between cumulative doses of prednisone and BMC, FBM, or LBM at any interval if absolute values were considered. However, relative changes in FBM correlated significantly with relative changes in prednisone cumulative doses.