Longitudinal associations between ambient air pollution with insulin sensitivity, β-cell function, and adiposity in Los Angeles Latino children
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 (NO2) and particulate matter with aerodynamic diameter less than 2.5 (PM2.5) had adverse effects on longitudinal measures of insulin sensitivity, 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 2001-2012 from Los Angeles, California and followed for an average of 3.4 years (standard deviation: 3.1 years). Linear mixed effects models were fitted to assess relationships between AAP exposure with outcomes after adjusting for covariates including body fat percent. Higher NO2 and PM2.5 were associated with a faster decline in SI and a lower insulin sensitivity (SI) at age 18 independent of adiposity. NO2 exposure negatively affected β-cell function evidenced by a faster decline in disposition index (DI) and a lower DI at age 18. Higher NO2 and PM2.5 exposures over follow-up were also associated with a higher BMI at age 18. AAP exposure may contribute to development of type 2 diabetes through direct effects on insulin sensitivity and β-cell function.