Insulin-like Growth Factor(IGF)-I and IGF-Binding Protein-3 in Relation to Hemoglobin Concentration in Healthy Infants

ABSTRACT

PURPOSE: Insulin-like growth factor(IGF-I) and IGF binding protein(IGFBP)-3 is thought to play an important role in fetal erythropoiesis. The objective of this study was to establish a relation between IGF-I, free IGF-I, IGFBP-1, and -3 with hemoglobin level in healthy term, 3-month, and 12-month old infants. METHODS: Healthy term infants(n=20)were enrolled at birth, as well as 3 monthsserum IGF-I concentrations were measured by a specific radioimmuno-assay(RIA), and the serum levels of free IGF-I, IGFBP-1 and -3 were measured by specific immunoradiometric assay(IRMA) kit.

RESULTS:

The mean level of hemoglobin was 15.6+/-1.4g/dL, IGF-I was 14.5+/-7.0ng/mL and IGFBP-3 was 1205.2+/-292.1ng/mL at birth. Serum IGF-I, IGFBP-3 and hemoglobin concentrations were correlated positively at birth(P<0.01), and a positive correlation was observed between hemoglobin and free IGF-I(P<0.05). The mean level of hemoglobin was 10.7+/-0.8g/dL, IGF-I was 27.3+/-11.1 ng/mL and IGFBP-3 was 1674.1+/-399.1ng/mL at three months of age. No correlation was observed between hemoglobin and IGF-I, IGFBP-3 and free IGF-I. The mean level of hemoglobin was 10.6+/-0.8g/dL, IGF-I was 45.5+/-13.9ng/mL and IGFBP-3 was 2124.5+/-401.8ng/mL at 12 months of age.

CONCLUSION:

Our results show that blood hemoglobin is positively correlated to serum IGF-I and IGFBP-3 concentrations, indirectly indicating the involvement of mediators of growth hormone on the regulation of physiologic hemoglobin concentration at birth.