Evaluation of Serum Insulin-Like Growth Factor(IGF)-I, Insulin-Like Growth Factor Binding Protein(IGFBP)-2 and IGFBP-3 Levels in Healthy Korean Children / 소아과

ABSTRACT

PURPOSE: We performed this study to evaluate the mean serum levels of insulin-like growth factor (IGF)-I, insulin-like growth factor binding protein(IGFBP)-2 and IGFBP-3 in healthy Korean children according to age and sex. METHODS: Ninety two healthy children, consisting of 42 boys and 50 girls, were classified into five groups according to age:neonate; infancy; early childhood; late childhood; and adolescence. We measured serum levels of IGF-I, IGFBP-2 and IGFBP-3 by enzyme-linked immunosorbent assay(ELISA) and analysed the serum levels according to sex and age group. RESULTS: For boys, the mean serum levels of IGF-I(ng/mL) in neonate, infancy, early childhood, late childhood and adolescence were 41.1+/-3.6, 70.9+/-33.7, 103.5+/-97.2, 89.8+/-46.5 and 51.4+/-27.8, respectively. Those of IGFBP-2(ng/mL) were 8.2+/-3.4, 5.8+/-0.4, 9.3+/-4.0, 9.5+/-1.1 and 7.0+/-0.5, respectively. Those of IGFBP-3(ng/mL) were 559.2+/-215.2, 1,333.3+/-692.5, 2,254.6+/-1,513.8, 2,447.1+/-1,464.2, 1,533.6+/-807.4, respectively. For girls, the mean serum levels of IGF-I(ng/mL) according to five age groups were 53.3+/-9.5, 99.3+/-45.8, 69.6+/-51.1, 106.2+/-67.0 and 145.1+/-127.8, respectively. Those of IGFBP-2 (ng/mL) were 9.1+/-7.4, 5.3+/-0.9, 6.9+/-2.0, 10.5+/-3.0 and 7.9+/-1.3, respectively. Those of IGFBP-3(ng/ mL) were 858.2+/-433.4, 1,834.8+/-851.3, 1,404.3+/-570.2, 2,203.5+/-899.4 and 2,029.3+/-1,316.7, respectively. There were significant positive correlations observed between IGF-I and IGFBP-3 levels(r=0.589, P= 0.000). CONCLUSION: IGF-I and IGFBP-3 levels increased as children get older. The peak level of IGFBP-3 was observed in late childhood for both boys and girls, suggesting a current trend of children reaching peak growth velocity before adolescence. The IGFBP-2 level was higher in neonates compare to infancy, suggesting that IGFBP-2 is an important substance for fetal growth.