Factors Associated with Cord Blood Leptin Concentration of Full - Term and Preterm Newboms

ABSTRACT

PURPOSE: Leptin is the product of the of gene secreted by adipocyte. The serum leptin concentration reflects the amount of adipose tissue in the body. We investigated whether leptin concentration was detectable in cord blood of newboms and assessed the effect of gestational age, birth weight, birth length, placental weight, body mass index and ponderal index on cord blood leptin concentration in full-term and preterm newboms. METHODS: Eighty-two newboms were enrolled in this study. Standard growth curves were used to categorize infants as appropriate (AGA), large (LGA), or small for gestational age (SGA). Gestational age, birth weight, length and placental weight were measured. Maternal age, weight and height were measured. Cord blood and maternal venous samples were collected and serum was separated and stored at -70C. Leptin was measured by radioimmunoassay. RESULTS: The mean leptin concentration in full term babies was 8.9+/-9.6 ng/ml compared with 3.5+/-0.6 ng/ml in preterm babies. Leptin concentrations in cord blood of full term babies were significantly increased in cornparison with those in cord blood of preterm babies. Mean serum leptin concentration of SGA infants was significantly lower than in AGA infants and that of LGA was higher than in AGA infants. In full-term and preterm neonates, there was significant positive correlation of leptin concentrations with birth weight, gestational age, birth length, BMI, ponderal index and placental weight. No gender differences were found in cord blood leptin. Maternal age, maternal body mass index, matemal weight at baseline (before pregnancy) and at birth were not significantly correlated with leptin concentration of full-term and preterm neonates. There was no significant correlation between leptin concentration of cord blood and matemal leptin concentration. CONCLUSION: The serum leptin concentration is highly correlated to the size of adipose tissue mass of newborn infant. Leptin may be responsible for regulation of body mass of human neonates and can be used as marker of the nutritional status and growth of fetal and neonatal period.