The Association Between PM _2.5 and Ozone and the Prevalence of Diabetes Mellitus in the United States, 2002 to 2008

Objective: To examine the association between air pollution and diabetes prevalence in the United States, 2002 to 2008. Methods: Annual average particulate matter (PM 2.5) and ozone concentrations were calculated using daily county-level data from the CDC's Tracking Network. Individual-level outcome and covariate data were obtained from the Centers for Disease Control and Prevention (CDC) Behavioral Risk Factor Surveillance System for 862,519 individuals. We used Poisson regression analyses to examine associations between each air pollutant (per 10-unit increase) with diabetes, including regional sub-analyses. Analyses were adjusted for year, age, sex, race, ethnicity, education, income, smoking status, body mass index, exercise, and asthma. Results: Positive associations between each pollutant and diabetes were found (PM 2.5: prevalence ratio [PR] = 1.10; 95% confidence interval [CI] = 1.03, 1.17; ozone: PR = 1.06; 95% CI = 1.03, 1.09). There was limited evidence of effect modification by region. Conclusions: Interventions to reduce ambient air pollution may help alleviate the diabetes burden in the US.