Growth hormone significantly increases the adult height of children with idiopathic short stature: comparison of subgroups and benefit

BACKGROUND Children with Idiopathic Short Stature do not attain a normal adult height. The improvement of adult height with treatment with recombinant human growth hormone (rhGH), at doses of 0.16 to 0.28 mg/kg/week is modest, usually less that 4 cm, and they remain short as adults. The benefit obtained seems dose dependent and benefits of 7.0 to 8.0 cm have been reported with higher doses of 0.32 to 0.4 mg/kg/week, but the number of studies is limited. The topic has remained controversial. OBJECTIVE The objective was to conduct a retrospective analysis of our experience with 123 children with ISS treated with 0.32 ± 0.03 mg/kg/week of rhGH, with the aim of comparing the different subgroups of non-familial short stature, familial short stature, normal puberty, and delayed puberty and to assess the benefit by comparison with 305 untreated historical controls, from nine different randomized and nonrandomized controlled studies. RESULTS Eighty eight of our children (68 males and 20 females) attained an adult height or near adult height of -0.71 SDS (0.74 SD) (95% CI, -0.87 to -0.55) with a benefit over untreated controls of 9.5 cm (7.4 to 11.6 cm) for males and 8.6 cm (6.7 to 10.5 cm) for females. In the analysis of the subgroups, the adult height and adult height gain of children with non-familial short stature were significantly higher than of familial short stature. No difference was found in the cohorts with normal or delayed puberty in any of the subgroups, except between the non-familial short stature and familial short stature puberty cohorts. This has implications for the interpretation of the benefit of treatment in studies where the number of children with familial short stature in the controls or treated subjects is not known. The treatment was safe. There were no significant adverse events. The IGF-1 values were essentially within the levels expected for the stages of puberty. CONCLUSION Our experience was quite positive with normalization of the heights and growth of the children during childhood and the attainment of normal adult heights, the main two aims of treatment.