Abstract
Evidence suggests that ambient air pollution (AAP) exposure may contribute to the development of obesity and type 2 diabetes. The objective of this study was to determine whether exposure to elevated concentrations of nitrogen dioxide (NO(2)) and particulate matter with aerodynamic diameter <2.5 (PM(2.5)) had adverse effects on longitudinal measures of insulin sensitivity (S(I)), β-cell function, and obesity in children at high risk for developing diabetes. Overweight and obese Latino children (8-15 years; n = 314) were enrolled between 2001 and 2012 from Los Angeles, CA, and followed for an average of 3.4 years (SD 3.1 years). Linear mixed-effects models were fitted to assess relationships between AAP exposure and outcomes after adjusting for covariates including body fat percent. Higher NO(2) and PM(2.5) were associated with a faster decline in S(I) and a lower S(I) at age 18 years, independent of adiposity. NO(2) exposure negatively affected β-cell function, evidenced by a faster decline in disposition index (DI) and a lower DI at age 18 years. Higher NO(2) and PM(2.5) exposures over follow-up were also associated with a higher BMI at age 18 years. AAP exposure may contribute to development of type 2 diabetes through direct effects on S(I) and β-cell function.