Seventy eight children born small for gestational age without catch-up growth treated with growth hormone from the prepubertal stage until adult height age. An evaluation of puberty and changes in the metabolic profile

Abstract

A wide variation in height gain rate is observed in children small for gestational age (SGA) treated with growth hormone (GH). The aim of this study was to evaluate prepubertal and pubertal growth, height gain attained at adult age and to assess potential predictive factors in catch-up growth. Changes in metabolic profile were also analyzed. Patients and methodsSeventy-eight children born SGA were treated with a GH median dose of 33.0±2.8mcg/kg/day at a mean age of 7.3±2.0 (boys) and 6.0±1.8 (girls). ResultsMean height (SDS) at GH onset was −3.31±0.7 for boys and −3.48±0.7 for girls. According to age at pubertal growth spurt onset patients were classified in their pubertal maturity group. Adult height attained expressed in SDS was −1.75±0.7 for boys and −1.69±1.0 for girls, both below the range of their mid-parental height. The greatest height gain occurred during the prepubertal period. Patients with greater height gain were lighter (p<0.001), shorter (p=0.005), and younger (p=0.02) at the start of GH, and also showed a greater increase in growth velocity during the first year on GH (p<0.001). SGA children started puberty at the same age and with the same distribution into pubertal maturity group as the reference population. No relevant GH-related adverse events were reported, including in the insulin resistance parameters evaluated. Differences were found in fasting plasma glucose values, but were without clinical relevance. IGF-I plasma values remained within the safety range. ConclusionsGH therapy is safe and beneficial for SGA children. The response to GH therapy is widely heterogeneous, suggesting that GH should be started at a young age and the GH dose prescribed should be individualized. SGA children started puberty at the same age as the reference population. The only factor that predicts greater adult height is growth velocity during the first year of therapy.