Longitudinal Associations Between Ambient Air Pollution With Insulin Sensitivity, β-Cell Function, and Adiposity in Los Angeles Latino Children

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.