Insulin-like growth factors (IGFs) and IGF binding proteins-1, -2, and -3 in newborn serum: relationships to fetoplacental growth at term (original) (raw)

1996, Early Human Development

Cord sera were obtained from term, Chilean newborns exhibiting various patterns of intrauterine growth and assayed for IGF-I, IGF-2, IGFBP-I, IGPBP-2, and IGFESP-3 by specific radioimmunoassays @IA). Serum levels of each peptide were correlated with birth weight (BW), ponderal index (PI), and placental weight (PW). Total IGF-I levels correlated with BW (r = 0.665, P = O.OOOl), PI (r = 0.527, P = 0.004), and PW (r = 0.596, P = 0.0017). Iu contrast, IGF-2 failed to correlate with any growth parameter. Of the three binding proteins, IGFEP-3 exhibited the strongest relationship to each growth parameter. IGPIW-3 correlated significantly with BW (r = 0.71, P i O.OOOl), PI (r = 0.782, P < O.OOOl), and PW (r = 0.57, P = 0.0029). In addition IGFFSP-3 levels positively correlated to IGF-1 levels (r = 0.614, P = 0.0005). By contrast, circulating IGFBP-1 and IGFBP-2 were inversely related to IGF-I levels. A11 five peptides were subjected to multiple regression analysis and *Corresponding author. Tel.: + 1 314 4542114; fax: + 1 314 7217480 0378-3782/96/$15.00 0 1996 Elsevier Science Ireland Ltd. All rights reserved PIf SO378-3782(96)01737-9 16 M. Osorio et al. I Early Hutnan Development 46 (1996) 15-26