Prenatal and Early Childhood Lead Exposure and Metabolic Syndrome Risk Indicators in 6 to 8 year-old Children

Abstract

BACKGROUND AND AIM: Exposure to lead (Pb) during early life stages has been associated with the development of metabolic syndrome (MS). Longitudinal studies in children are limited. We aimed to examine the association between prenatal and early childhood exposure to Pb and risk indicators of MS between 6 and 8 years of age. METHODS: Our study included 601 mother-child dyads participating in the PROGRESS birth cohort, children included were full term. Blood lead levels (BLLs) were assessed prenatally, during the second and third trimesters, in cord blood at delivery, and postnatally in early childhood at ages 1, 2 and 4 years of age. To account for cumulative exposure, we created scores (prenatal, postnatal, and overall) dichotomizing BLLs at each stage visit and categorized as: always above if BLLs was above the median (AA), never above if all BLLs was below the median (NA), and sometimes above otherwise (SA). We analyzed fasting glucose, HbA1c, triglycerides, total cholesterol, HDL cholesterol, LDL cholesterol, body mass index, waist circumference, body fat percentage, systolic and diastolic blood pressure at 72 and 96 months of age. Mixed-effects models were used to analyze each outcome longitudinally for prenatal, postnatal, and overall BLLs scores, adjusting for socioeconomic status, sex, size for gestational age, parity, maternal and children’s age. RESULTS:We observed associations for total cholesterol with SA prenatally (β: -6.13, 95% CI: -11.0, -1.23), postnatally (β: -6.16, 95% CI: -11.8, -0.46) and overall (β: -6.66, 95% CI: -11.2, -2.10); LDL cholesterol and prenatal SA (β: -4.901, 95% CI: -9.13, -0.66); systolic blood pressure and overall AA (β: -1.851, 95% CI: -3.60, -0.09); HbA1c and postnatal SA (β: -0.10, 95% CI: -0.20, -0.001). CONCLUSIONS:Early life exposure to Pb may alter early indicators of MS. Follow-up of these children will allow for more definition on the longer-term impact of exposure. KEYWORDS: Lead Exposure, Prenatal Exposure, Metabolic Syndrome, Early Childhood