Revista médica de Chile
versión impresa ISSN 0034-9887
ROMAN R, Rossana et al. IGF-I sensitivity in small for gestational age children. Rev. méd. Chile [online]. 2006, vol.134, n.1, pp.21-30. ISSN 0034-9887. http://dx.doi.org/10.4067/S0034-98872006000100003.
Background: The lack of catch up growth (CUG) in small for gestational age (SGA) children may be related to a reduced sensitivity to insulin growth factor 1 (IGF-I). Aim: To assess the sensitivity to IGF-I in small for gestational age children, measuring basal and post IGF-I nocturnal profile of growth hormone (GH). Patients and methods: We studied 34 prepubertal SGA children aged 4 to 11 years. Twenty three had CUG and 11 did not have CUG. As an IGF-I sensitivity test, nocturnal GH levels were measured every 20 minutes from 23:00 h to 07:00 h, both under baseline conditions and after the administration of a subcutaneous bolus of 1 mg/kg/body weight of the IGF-I + IGFBP-3 complex (Somatokine®). Results: At the time of the study, the Z scores for height among children with and without CUG were -1.55 ± 0.22 and -3.24 ± 0.28, respectively (p <0.0001). There were no statistical differences between CUG + vs CUG- patients in mean basal GH (6.6 ± 0.5 and 5.6 ± 0.6 ng/ml, respectively). After Somatokine® administration, mean GH, and the mean GH area under the curve (AUC) decreased significantly in both groups. However, mean overnight GH AUC decreased in all SGA children with CUG, after Somatokine® administration, whereas 3 out of 11 SGA children without CUG had an increase in their mean GH AUC in response to Somatokine®. Conclusions: These findings suggest that pituitary sensitivity to IGF-I may be decreased in some SGA children without CUG
Palabras clave : Infant; small for gestational age; Insulin-like growth factor I; Human growth hormone.