Insulin Sensitivity Modulates the Growth Response during the First Year of High-Dose Growth Hormone Treatment in Short Prepubertal Children Born Small for Gestational Age

AIM: To study the relationship between insulin sensitivity and growth response in short children born small for gestational age (SGA) treated with growth hormone (GH). METHODS: Randomized, open-label, 24-month intervention study in 40 short prepubertal SGA children [age (mean ± SD) 5.3 ± 1.5 years], who either remained untreated (n = 20) or were treated with GH (66 µg/kg/day; n = 20). Changes in fasting glucose, insulin, quantitative insulin sensitivity check index (QUICKI), IGF-1 and leptin after 1 and 2 years were studied. RESULTS: Mean height SDS increased from -3.3 ± 0.7 to -2.3 ± 0.7 after 1 year, and to -1.9 ± 0.7 after 2 years of treatment. QUICKI decreased significantly (p = 0.008) in the first year of GH treatment and stabilized in the second year. Baseline QUICKI was positively associated (r = 0.40; p < 0.05) with the change in height SDS in the first year. CONCLUSION: Higher insulin sensitivity at the start of GH therapy is associated with greater first-year growth response to GH, and could be a promising parameter in selecting prepubertal short SGA children for GH treatment. However, this finding needs to be confirmed in larger studies.