Cord blood levels of interleukin-10 decrease in neonates with increased birth weight: novel implications of the cytokine network in early obesity.

Abstract

Interleukin-10 (IL-10) and interferon-gamma (IFN-gamma) are associated with body weight alterations in children, adolescents, and adults. However, little is known regarding the role of IL-10 and IFN-gamma in birth weight of neonates. One hundred eighty-two infants were enrolled and divided in groups of normal birth weight (< 95th percentile) or increased birth weight (> 95th percentile) for gestational age. IL-10 and IFN-gamma levels were measured in umbilical cord tissue and blood of newborns by quantitative polymerase chain reaction (qPCR) and enzyme-linked immunosorbent assay (ELISA). The average value of birth weight in infants below and above the 95th percentile was 3.03±0.39 and 3.58±0.37 kg, respectively, and was independent of the mother's pre-gestational body mass index. The Student t test revealed that neonates with birth weights > 95th percentile show a significant 30% decrease in cord blood values of IL-10 as compared to infants with birth weights < 95th percentile (P<0.0001), with no significant changes in IFN-gamma levels (P=0.1661). Cord blood IL-10 was not of maternal origin but produced by umbilical cord tissue that showed less IL-10 expression in neonates with birth weights > 95th percentile than in infants with birth weights < 95th percentile (P=0.0252). Cord blood levels of IL-10 exhibited significant inverse correlations with birth weight (r = - 0.658, P=0.002) and INF-gamma (r = - 0.502, P=0.005).Conclusion: In conclusion, this work demonstrates for the first time that cord blood IL-10 decreases as birth weight increases in infants born at term and might help to improve early recognition of newborns at higher risk of developing obesity in childhood or adulthood. What is Known: • Reduction in interleukin-10 levels has been associated with obesity in adolescents and adults but not newborns. • The number of neonates with excess birth weight has alarmingly increased in the last 30 years. What is New: • We demonstrate that umbilical cord blood levels of interleukin-10 clearly decrease as birth weight increases. • Interleukin-10 and interferon-gamma integrate a cytokine network that might play a role in obesity in infants.