Ambient ozone and incident diabetes: A prospective analysis in a large cohort of African American women

Ozone is a ubiquitous air pollutant with increasing concentrations in many populous regions. Toxicological studies show that ozone can cause oxidative stress and increase insulin resistance. These pathways may contribute to metabolic changes and diabetes formation. In this paper, we investigate the association between ozone and incident type 2 diabetes in a large cohort of African American women. We used Cox proportional hazards models to calculate hazard ratios (HRs) for incident type 2 diabetes associated with exposure to ozone in a cohort of 45,231 African American women living in 56 metropolitan areas across the United States. Ozone levels were estimated using the U.S. EPA Models-3/Community Multiscale Air Quality (CMAQ) predictions fused with ground measurements at a resolution of 12km for the years 2007–2008. The HR per interquartile range increment of 6.7ppb of ozone was 1.18 (95% CI 1.04–1.34) for incident diabetes in adjusted models. This association was unaltered in models that controlled for fine particulate matter with diameter