Association between air pollution exposure and diabetic retinopathy among diabetics

Background: Exposure to air pollution has been linked to adverse effects on vascular diseases. However, the effects of air pollution exposure on diabetic retinopathy (DR), a vascular disease, have not been studied. Objective: To determine the association of ambient air pollution exposure with DR risk. Methods: Patients newly diagnosed as having diabetes mellitus (DM) during 2003–2012 from Longitudinal Health Insurance Database 2005), a subset of National Health Insurance Research Database, were included as the study cohort. Newly diagnosed DR patients one year or later after DM diagnosis were identified as cases. Kriging was used to interpolate yearly concentrations of air pollutants at township levels and linked with every individual's residence in each year; average concentrations during the follow-up period were then calculated as personal exposure. Conditional logistic regressions with adjustments for age at DM diagnosis and comorbidities were applied. Results: Of newly diagnosed DM cases during 2003–2012, 579 were newly diagnosed as having DR over a mean follow-up period of 5.6 years. The Odds ratio (95% confidence interval) of DR occurrence for every 10-μg/m³ increase in particulate matter with ≤2.5 and 2.5–10-μm diameter was 1.29 (1.11–1.50) and 1.37 (1.17–1.61), respectively. Conclusion: In patients with DM, the higher particulate matter exposure, the higher is the DR risk.