Insulin-like growth factor (IGF)-I, IGF binding protein (IGFBP)-3, phosphoisoforms of IGFBP-1 and postnatal growth in very-low-birth-weight infants.
Small preterm infants experience a unique postnatal period characterized by slow growth, inadequate nutrition and growth inhibiting treatments. Many have already been growth-restricted in utero. Studying this period is important when developing growth optimizing strategies for these infants and, in a broader context, as a model of extreme conditions that restrict growth. By following short-term growth of 48 very-low-birth-weight (VLBW; birth weight <1,500 g) infants for 9 postnatal weeks, we found that circulating insulin-like growth factor (IGF)-I and IGF binding protein (IGFBP)-3 levels are low and reflect rigorously measured (knemometry and weight) concurrent growth velocity. Moreover, weight growth velocity is correlated with the ratio of lesser to highly phosphorylated IGFBP-1 but not with absolute IGFBP-1 concentrations. Thus, IGF-I, IGFBP-3 and the phosphorylation status of IGFBP-1 in circulation are likely to be involved in growth regulation during the postnatal period in VLBW infants.
Kajantie
Eero
E
Helsinki University Central Hospital, Hospital for Children and Adolescents, Helsinki, Finland. eero.kajantie@helsinki.fi
D005317:Fetal Growth Retardation / Q000378:metabolism; D005865:Gestational Age; D006801:Humans; D007227:Infant Nutritional Physiological Phenomena; D007231:Infant, Newborn; D019102:Infant, Very Low Birth Weight / Q000254:growth & development*; D018970:Insulin-Like Growth Factor Binding Protein 1 / Q000235:genetics; D018972:Insulin-Like Growth Factor Binding Protein 3 / Q000502:physiology*; D007334:Insulin-Like Growth Factor I / Q000502:physiology*; D007866:Leg / Q000254:growth & development; D010766:Phosphorylation; D020033:Protein Isoforms / Q000502:physiology; D012044:Regression Analysis
D018970:Insulin-Like Growth Factor Binding Protein 1; D018972:Insulin-Like Growth Factor Binding Protein 3; D020033:Protein Isoforms; D007334:Insulin-Like Growth Factor I