The role of IGF-1 and ghrelin in the compensation of intrauterine growth restriction.

The role of insulin-like growth factor 1 (IGF-1) and ghrelin in intrauterine growth restricted (IUGR) neonates in comparison to appropriate for gestational age (AGA) ones was investigated. Levels of IGF-1/insulin-like growth factor binding protein 3 (IGFBP3), ghrelin, insulin, and cortisol were determined in 20 singleton, full-term IUGR and 20 respective AGA neonates at birth (umbilical cord-UC), on days 1 (d1) and 4 (d4) postnatally. The ratio of IGF-1 to birth weight was higher in IUGR than in AGA in both UC (18.2 +/- 1.2 vs14.4 +/- 0.9, P = .05) and d1 (9.6 +/- 0.5 vs 6.8 +/- 0.3, P = .05). A significant positive correlation was found between IGF-1 and ghrelin levels and a negative one between IGFBP3 and ghrelin only in IUGR. In both groups, fetal IGF-1 levels negatively correlated with fetal cortisol levels. Intrauterine growth restricted neonates demonstrate a relative IGF-1 resistance in an attempt to drive energy toward survival on the expense of growth. The observed correlations between ghrelin and IGF-1/IGFBP3 postnatally indicate that ghrelin might play a role in the compensation of intrauterine undernutrition, promoting postnatal growth.