Early lead exposure and childhood adiposity in Mexico city.

BACKGROUND: Prenatal and early childhood lead exposures have been associated with reduced weight in infants and young children, while studies that have examined such associations in children during peripubescence are rare. OBJECTIVES: We investigated the associations of prenatal and early-life exposure to lead with indices of adiposity in peripubertal children living in Mexico City. METHODS: Maternal bone lead (as a proxy for cumulative fetal exposure) was assessed at 1 month postpartum. Blood samples were obtained from children annually from 1 to 4 years. Multivariable linear regression models were used to examine the association between each lead biomarker and BMI z-score, waist circumference, sum of skinfolds and body fat percentage in 248 children aged 8-16 years. RESULTS: After adjusting for covariates, maternal patella lead was associated with lower child BMI z-score (ß = -0.02, 95% CI: 0.03, -0.01, p = 0.004), waist circumference (ß = -0.12 cm, 95% CI: 0.22, -0.03, p = 0.01), sum of skinfolds (ß = -0.29 mm, 95% CI: 0.50, -0.08, p = 0.007) and body fat percentage (ß = -0.09%, 95% CI: 0.17, -0.01, p = 0.03). No significant associations were detected from the postnatal exposure period. CONCLUSIONS: We observed a significant and inverse association of prenatal lead exposure with body composition in Mexican children, suggesting the potential role of early lead exposure in the fetal programming of child growth. Further research on the biological mechanisms underlying these associations is needed.