Response to IGF-1 Generation Test in Short Prepubertal Children Born Very Preterm or at Term

Abstract

Aims: To investigate whether short children born very preterm (<32 weeks of gestation) exhibit features of growth hormone (GH) resistance compared to term peers. Methods: We studied 26 prepubertal children (aged 7.0 ± 2.0 years) with short stature (height adjusted for parents' heights <10th percentile), who were born appropriate for gestational age and either very preterm (n = 11) or at term (n = 15). Children underwent insulin-like growth factor-1 (IGF-1) generation test via a daily recombinant human GH (rhGH) dose (0.05 mg/kg/day) over 4 consecutive days. Hormone and binding proteins were measured at baseline and day 5. Results: At baseline, preterm children had lower IGF-binding protein 1 (IGFBP-1; -22%; p = 0.049) and IGFBP-3 (-24%; p = 0.013) concentrations than term children. Preterm children also had insulin concentrations that tended to be 39% higher (p = 0.059) than term peers. After stimulation, IGF-1 and IGFBP-3 concentrations increased similarly in term and preterm groups, while GH-binding protein (GHBP) concentrations decreased in both groups. Preterm children had higher GHBP (+50%; p = 0.049), insulin (+86%; p = 0.005), and leptin (+107%; p = 0.020) but lower IGFBP-1 (-47%; p = 0.006) concentrations than term children following rhGH stimulation. Conclusions: Preterm children who are short for genetic height potential show no evidence of GH resistance that would explain their short stature. However, there was indirect evidence of insulin resistance in the preterm children, as previously described in this group.

Gestational age and childhood leukemia: A meta-analysis of epidemiologic studies

“…Moreover, the expression levels of IGF-1, IGF-2 and insulin-like growth factor binding protein (IGFBP)-3 were found to increase with gestational age, while that of IGFBP-2 was observed to decrease in fetal blood [30][31][32]. Some premature infants experienced postnatal catch-up growth that stimulated the expression of IGF [33,34]. Postterm pregnancies were associated with an approximately two-fold increased risk of macrosomia [35], and high birth weight was shown to be related to an increased risk of AML [4].…”

Idiopathic short stature and growth hormone sensitivity in prepubertal children

“…As we and others have shown, the very wide variation in IGF‐I response to rhGH stimulation in children limits its value as a tool to inform the management of children with growth disorders. We also did not include children born SGA or large‐for‐gestational age in this study, which would have further explored the association between birthweight and GH sensitivity.…”