Blood Lead Levels and Neurodevelopmental Function in Perinatally HIV-Exposed,Uninfected Children in a U.S.-Based Longitudinal Cohort Study

Abstract

While children's exposure to environmental lead in the United States has decreased, areas of elevated levels remain. Because lead exposure is a risk factor for developmental delays, it should be considered when studying neurodevelopmental effects of in utero antiretroviral medication (ARV) exposure in the growing population of perinatally HIV-exposed, uninfected (PHEU) children. We compared blood lead levels (BPb) in PHEU children enrolled in the Surveillance Monitoring of ART Toxicities (SMARTT) Study to U.S. children, assessed associations with neurodevelopment, and explored whether associations between in utero ARV and neurodevelopment are modified by BPb. Prevalence of elevated BPb (≥5 μg/dl) at ages 1–2 years was calculated by year and race/ethnicity and compared to that for children in the National Health and Nutrition Examination Survey (NHANES 2002–2010). Associations between elevated BPb and neurodevelopment at 1 and 3 years were assessed. Associations between ARVs (tenofovir disoproxil fumarate [TDF]; atazanavir) and neurodevelopment were evaluated within BPb level (≥5 μg/dl vs. <5 μg/dl). Mean BPb in SMARTT decreased from 5.9 to 2.7 μg/dl between 1998 and 2014; prevalence of elevated BPb decreased from 50% to 4%. Both were consistently higher than in NHANES. Elevated BPb was associated with cognitive delay at age 3 (adjusted odds ratio: 1.64; 95% confidence interval: 0.95–2.90). At age 1, TDF was associated with delay only among those with elevated BPb. PHEU children more often had elevated BPb than the general U.S. pediatric population. Exposure to environmental lead is one of several factors that may place these children at higher risk for neurodevelopmental delay.