Growth impairment at renal transplantation--a determinant of growth and final height

Long-term outcome of growth and final adult height (FH) are a major concern of children after a renal transplantation (Tx). We therefore studied the yearly measurements of height (Ht), expressed as the Z-score and bone age (BA), in 58 children (28 girls) transplanted in our departments and followed-up for 5-18 (mean 9.6) yr after the operation. Twenty-four children reached final adult height. Renal function was evaluated as the glomerular filtration rate (GFR), which is estimated from the clearance of inulin. The mean Ht Z-score at Tx was -1.3 in girls and -2.7 in boys and increased to -0.6 and -1.5, respectively, at 5 yr after Tx. The greatest increase, seen in the shortest children and those transplanted before 7 yr of age, occurred during the first 3 yr. Children aged 7-12 yr at Tx showed an increase in height during the first years after the transplant, while those transplanted at >12 yr of age were not growth-retarded and therefore did not change their Ht Z-score. The most growth-retarded were also the most BA retarded. The mean FH Z-score was -1.1. A direct correlation was seen between GFR at 1 yr after Tx and the increase in height Z-score from Tx to 1 and 5 yr after Tx. In summary, the increment in height following Tx was the greatest in the most growth-retarded children and most marked during the first 3 yr after the transplant. FH was within normal range in 75% of the children. A high Ht Z-score at Tx had a positive effect on FH. Thus, growth after Tx was affected by the degree of stunting at Tx and renal function after Tx.