Long-term exposure to ambient air pollution and renal function in African Americans: the Jackson Heart Study

Renal dysfunction is prevalent in the US among African Americans. Air pollution is associated with renal dysfunction in mostly white American populations, but has not been studied among African Americans. We evaluated cross-sectional associations between 1-year and 3-year fine particulate matter (PM_2.5) and ozone (O₃) concentrations, and renal function among 5090 African American participants in the Jackson Heart Study. We used mixed-effect linear regression to estimate associations between 1-year and 3-year PM_2.5 and O₃ and estimated glomerular filtration rate (eGFR), urine albumin/creatinine ratio (UACR), serum creatinine, and serum cystatin C, adjusting for: sociodemographic factors, health behaviors, and medical history and accounting for clustering by census tract. At baseline, JHS participants had mean age 55.4 years, and 63.8% were female; mean 1-year and 3-year PM_2.5 concentrations were 12.2 and 12.4 µg/m³, and mean 1-year and 3-year O₃ concentrations were 40.2 and 40.7 ppb, respectively. Approximately 6.5% of participants had reduced eGFR (< 60 mL/min/1.73m²) and 12.7% had elevated UACR (> 30 mg/g), both indicating impaired renal function. Annual and 3-year O₃ concentrations were inversely associated with eGFR and positively associated with serum creatinine; annual and 3-year PM_2.5 concentrations were inversely associated with UACR. We observed impaired renal function associated with increased O₃ but not PM_2.5 exposure among African Americans.