Cord blood leptin levels in relation to child growth trajectories.

Objective: Leptin represents a potential modulator of developmental programming of childhood obesity. We investigated the association of cord blood leptin with growth trajectories from birth to early childhood.

Materials/methods: We used data from the prospective mother-child cohort "Rhea", Crete, Greece. Cord blood samples from 642 neonates were collected. 578 (90%) children had complete follow up data from birth to 4years. We measured child weight, height, waist circumference, skinfold thicknesses, blood pressure, and serum lipids, leptin, adiponectin and C-reactive protein in early childhood (median 4.2years). We estimated growth trajectories from 3months up to 4years using random-effects linear-spline models. Multivariable logistic and linear regression models were used adjusting for confounders.

Results: Mean cord blood leptin levels were 7.3ng/mL (standard deviation: 6.3). Children with high cord blood leptin (>90th percentile) exhibited lower weight, height and body mass index from 6months to early childhood. Each SD increase in cord blood leptin was associated with lower weight at the age of 4 by 242g (95% CI: -416, -69). In a stratified analysis, the reverse association was observed in children born small for gestational age (p for interaction=0.001), and in those exhibiting rapid infant growth during the first 3months of life (p for interaction=0.002). Cord blood leptin levels were not associated with cardiometabolic risk factors at 4years.

Conclusions: Long term programming effects of in utero exposure to leptin extends beyond infancy into early childhood. Further studies are needed to explore potential effect modification by intrauterine and early infancy growth patterns.