Final Height in Children with Idiopathic Growth Hormone Deficiency Treated with a Fixed Dose of Recombinant Growth Hormone

Abstract

There is no consensus regarding the optimal dosing of recombinant human growth hormone (rhGH) for children with growth hormone deficiency (GHD). Our objective was to evaluate the final adult height (FAH) in children with idiopathic GHD treated with a fixed rhGH dose of 0.18 mg/kg/week. We reviewed all charts of patients with idiopathic GHD treated with rhGH since 1985 who reached FAH. Ninety-six patients were treated for an average of 5.4 years. The mean age was 11.9 years, the mean height –2.87 standard deviation score (SDS) and the mean FAH was –1.04 SDS. Females had a lower predicted adult height than males at the initiation of therapy (–2.0 vs. –1.01 SDS; p = 0.0087) but a higher FAH – predicted adult height (1.08 vs. 0.04 SDS; p = 0.0026). In multiple regression analysis, the FAH SDS was positively related to the midparental height SDS, the height SDS at GH initiation and growth velocity during the first year of therapy, and negatively correlated with peak GH and bone age at initiation (r² = 0.51; p < 0.005). Treatment of children with idiopathic GHD with a fixed dose of 0.18 mg/kg/week rhGH is sufficient to reach FAH within 2 SDS of the normal population range (84%) with an average FAH within –0.5 SDS of midparental height.

Auxological and hormonal prognostic factors of growth hormone (GH) therapy effectiveness in children with GH deficiency, available before treatment

“…Namely, in children with more severe deficit of height with respect to TH (nonFSS Group), the height gain during GH therapy was significantly better than in FSS Group, independently from similar GH and IGF-I levels in both Groups. Our observations are quite consistent with the results of other studies [18,19].…”

Growth hormone regimens in Australia: analysis of the first 3 years of treatment for idiopathic growth hormone deficiency and idiopathic short stature

“…It can be concluded, from the results presented here, and from other studies 1,4,[10][11][12]14,15,[22][23][24]26,28,29,31,32,[34][35][36]40 that optimal response, over both the short and long term, for GHD and ISS can be achieved by initiating GH as early as possible. By comparing the first-year response as a function of starting age to the curves published by Bakker, 13 and first-year response on adult height achievement, it would also appear false economy to start with low doses and react to poor response by incremental dosing.…”

“…It is likely that the reason for the similarity in response, despite a lower mean dose, is the younger median age of commencement of GH treatment in Australia. Commencement age in the present study is 5AE1 years for BGHD, 8AE2 years for SSSG-ISS and 6AE6 years for SSSG-FSS, which is considerably younger than mean/median ages reported in international studies; GHD: 6AE6-9AE3 years [10][11][12][22][23][24][25][26][28][29][30]32 and ISS: 7AE8-11AE9 years [3][4][5]14,24 ). This hypothesis is supported by the work by Bang et al 33 who recently published a first-year DSDS of 0AE64 for ISS patients who received a starting dose similar to that reported here in Australia (0AE22 mg/kg/week) but who began treatment at an even younger age (7AE0 years).…”

“…1,4,11,12,[22][23][24]26,28,29,32,34,35 This relationship has been shown specifically for both GHD and ISS by Bakker et al 13 and…”

“…First-year response is known to be highly correlated with adult height in both GHD and ISS. 4,[10][11][12] First-year response was compared with international benchmarks and DSDS compared with response with respect to the age of treatment commencement graphs published by Bakker et al 13 GV was also calculated for comparison with the recent comprehensive work on GV response to GH by Bakker et al 13 Finally, factors influencing response were identified.…”