Lead Exposure in Infancy and Subsequent Childhood Growth

Abstract

Studies suggest that elevated postnatal blood lead levels (BLLs) are negatively associated with child growth. This study aimed to investigate associations of childhood BLLs at age one-year and growth outcomes at age six-years (n=661) in a cohort of children in Allada, Benin. The growth outcomes studied are weight-for-age Z-score (WAZ), height-for-age Z-score (HAZ) and BMI-for-age Z-score (BMIZ), head circumference (HC), underweight, stunting, and wasting. Multivariable regression models examined associations between blood lead levels, growth outcomes with adjustment for potential confounders. The geometric mean BLLs was 59.3 μg/L and 82% of children had BLLs >35 μg/L at one year. After adjusting for confounding factors, no association was found between BLLs quartiles and HAZ, WAZ, BMIZ, and height and weight growth velocities. However, boys in the highest quartile had 1.02 cm lower HC (95% CI: [-1.81, -0. 24]) as compared to those in the lowest quartile with a dose-response trend across quartiles (Ptrend =0.02). Furthermore, an increased risk of being stunted was observed in children in the highest quartile of exposure compared to the first (OR: 2.43; 95% CI: [1.11 – 5.33]) with a dose-response trend (Ptrend =0.03). Blood lead was found to be associated with an increased risk of childhood stunting and lower head circumference in a resource-limited setting.