A Comparison of Different Definitions of Growth Response in Short Prepubertal Children Treated with Growth Hormone

<i>Background:</i> How to define poor growth response in the management of short growth hormone (GH)-treated children is controversial. <i>Aim:</i> Assess various criteria of poor response. <i>Subjects and Methods:</i> Short GH-treated prepubertal children [n = 456; height (Ht) SD score (SDS) ≤–2] with idiopathic GH deficiency (IGHD, n = 173), idiopathic short stature (ISS, n = 37), small for gestational age (SGA, n = 54), organic GHD (OGHD, n = 40), Turner syndrome (TS, n = 43), skeletal dysplasia (n = 15), other diseases (n = 46) or syndromes (n = 48) were evaluated in this retrospective multicenter study. Median age at GH start was 6.3 years and Ht SDS –3.2. <i>Results:</i> Median [25–75 percentile] first-year gain in Ht SDS was 0.65 (0.40–0.90) and height velocity (HtV) 8.67 (7.51–9.90) cm/year. Almost 50% of IGHD children fulfilled at least one criterion for poor responders. In 28% of IGHD children, Ht SDS gain was <0.5 and they had lower increases in median IGF-I SDS than those with Ht SDS >0.5. Only IGHD patients with peak stimulated growth hormone level <3 µg/l responded better than those with ISS. A higher proportion of children with TS, skeletal dysplasia or born SGA had Ht SDS gain <0.5. <i>Conclusion:</i> Many children respond poorly to GH therapy. Recommendations defining a criterion may help in managing short stature patients.