Multiple Correlations Between Cord Blood Leptin Concentration and Indices of Neonatal Growth

Abstract

The discovery of a role for leptin in controlling fetal and neonatal growth suggests a fetal origin of some adult chronic diseases and has stimulated research into the mechanisms of action of leptin early in life. The aim of this study was to determine umbilical cord blood leptin levels and to evaluate their association with newborn growth indices. Two hundred healthy newborns (89 males, 110 females, and one of undetermined gender; gestational ages ranging from 34-43 weeks) and their healthy mothers were enrolled in this study conducted at Moovsavi Hospital in Zanjan, Iran. The body size index of each newborn was determined in terms of birth weight, birth length, head circumference, body mass index (BMI) and ponderal index. Umbilical cord blood leptin levels were measured by ELISA. Umbilical cord leptin concentration was found to positively correlate with birth weight (r=0.322; p<0.0001), neonatal BMI (r=0.247; p<0.0001), ponderal index (r=0.206; p=0.04), and gestational age (r=0.221; p=0.002). There was no significant correlation between cord leptin and birth length or umbilical glucose concentration. Umbilical cord leptin concentrations (15.20+/-12.3 vs. 12.08+/-11.7; p=0.01) were significantly greater in female as compared to male newborns, respectively. Linear regression analysis indicated that umbilical cord leptin levels correlated with birth weight, umbilical triglyceride concentration, neonatal gender, and method of delivery. Our findings confirm the association of leptin concentrations with weight gain in fetal and newborn infants.