Long-term exposure to traffic-related air pollution and systemic lupus erythematosus in Taiwan: A cohort study

Systemic lupus erythematosus (SLE) is a multi-systemic chronic autoimmune disease, the etiology of SLE is still unclear. Only a few studies evaluated the associations between air pollution and SLE. We conducted a population-based cohort study in Taiwan to examine the associations of air pollution with SIE. A total of 682,208 individuals aged 18-70 years were retrieved from National Health Insurance Research Database. We applied 1-km resolution land use regression and satellite-based models to estimate air pollutant concentrations during 2001-2010. The mixed effect Cox models with lime-dependent variables were performed to estimate the associations between air pollution and SLE, as hazard ratios (HRs) with 95% confidence interval (CI). We identified 1292 newly diagnosed SLE patients with average age of 4326 +/- 13.64 years, most of them were female. There were positive associations of SLE with exposure to a 9.76 ppb increase in nitrogen dioxide (NO2), a 0.20 ppm increase in carbon monoxide (CO), and a 10.2 mu g/m(3) increase in fine particles (PM2.5) (HR = 1.21, 95% CI: 1.08-1.36, HR = 1.44, 95% CI: 131-1.59, and HR = 1.12, 95% CI: 1.02-123, respectively). Additionally, we observed negative associations with ozone (O-3) and sulfur dioxide (SO2). According to the exposure-response relationships, exposure to NO2 between 28 and 38 ppb, exposure to CO above 0.6 ppm, and exposure to PM2.5 between 18 and 46 mu g/m(3) were positively associated with SLE. The results suggested that long-term exposure to traffic-related gaseous air pollutants (NO2 and CO) less than current National Ambient Air Quality Standards and PM2.5 are significantly associated with the risk of SLE. (C) 2019 Elsevier B.V. All rights reserved.