Differential associations of leptin with adiposity across early childhood

OBJECTIVE To examine associations of perinatal and 3-year leptin with weight gain and adiposity through 7 years. DESIGN AND METHODS In Project Viva, plasma leptin from mothers at 26-28 weeks' gestation (n = 893), umbilical cord vein at delivery (n = 540), and children at 3 years (n = 510) was assessed in relation to BMI z-score, waist circumference, skinfold thicknesses, and dual X-ray absorptiometry body fat. RESULTS 50.1% of children were male and 29.5% non-white. Mean (SD) maternal, cord, and age 3 leptin concentrations were 22.9 (14.2), 8.8 (6.4), and 1.8 (1.7) ng/ml, respectively, and 3- and 7-year BMI z-scores were 0.46 (1.00) and 0.35 (0.97), respectively. After adjusting for parental and child characteristics, higher maternal and cord leptin were associated with less 3-year adiposity. For example, mean 3-year BMI z-score was 0.5 lower (95% CI: -0.7, -0.2; P-trend = 0.003) among children whose mothers' leptin concentrations were in the top versus bottom quintile. In contrast, higher age 3 leptin was associated with greater weight gain and adiposity through age 7 [e.g., change in BMI z-score from 3 to 7 years was 0.2 units (95% CI: -0.0, 0.4; P-trend =0.05)]. CONCLUSION Higher perinatal leptin was associated with lower 3-year adiposity, whereas higher age 3 leptin was associated with greater weight gain and adiposity by 7 years.