Growth after discontinuation of recombinant human growth hormone therapy in children with chronic renal insufficiency

Objectives: The impact of a pause in treatment with recombinant human growth hormone (rhGH) during the course of chronic renal insufficiency (CRI) once target height (50th percentile for mid-parental height) is reached and the impact of cessation of rhGH treatment after successful renal transplantation were evaluated. Prepubertal patients with CRI included in a multicenter, randomized, double-blind, placebo-controlled trial who either reached target height or received a renal transplant, or both, were included in this report. Patients in the placebo group may have initiated pubertal development at the time rhGH treatment was begun. Study design: Growth velocity (measured in centimeters per year) and standardized height score (SDS) in 22 patients who had a pause in rhGH therapy after attainment of target height were evaluated serially before and after the pause, and 30 patients, 4 of whom were also included in the pause group, who discontinued rhGH therapy at the time of transplantation were followed as long as 68 months after transplantation. Results: Six of twenty-two patients (two of whom subsequently underwent transplantation) continued with the pause in treatment for a mean (+/-SD) duration of 25.5 +/- 26.9 months (group 1), and 16 of 22 resumed rhGH therapy after pausing for a mean (+/-SD) of 9.0 +/- 4.6 months (group 2). The mean (+/-SD) growth velocity during the pause in group 1 was 5.1 +/- 1.8 cm/yr and in group 2 2.7 +/- 1.7 cm/yr, After reinstitution of rhGH in group 2, the mean (+/-SD) growth velocity increased to 7.2 +/- 1.7 cm/yr, The mean (+/-SD) height SDS in the 30 patients who discontinued rhGH therapy at the time of transplantation was -2.8 +/- 0.9 at baseline (initiation of rhGH therapy), -1.6 +/- 1.3 at the time of transplantation, and -1.7 +/- 1.2 at last follow-up. The mean (+/-SD) growth velocity was 5.1 +/- 4.7 cm/yr after transplantation, and the mean (+/-SD) delta (Delta) height SDS was -0.07 +/- 0.5 at last follow-up. Conclusions: A pause in rhGH treatment in children with CRI after attainment of target height leads to maintenance of height SDS in 27% and a marked reduction in growth velocity, requiring reinstitution of rhGH therapy, in 73%; discontinuing rhGH treatment at the time of transplantation does not result in substantive posttransplantation ''catch down'' growth.