Association between long-term exposure to air pollution and diabetic retinopathy: Evidence from the Fujian Eye Study

Diabetic retinopathy (DR), one of the most common microvascular complications of diabetes mellitus (DM), is a major contributor of vision impairment and blindness worldwide. Studies have shown that air pollution exposure is adversely associated with DM. However, evidence is scarce regarding how air pollution exposure affects DR. This study aimed to investigate the association between ambient air pollution exposure and DR risk. The study population was based on the Fujian Eye Study (FJES), an ophthalmologic, epidemiologic survey investigating the eye health condition of residents in Fujian Province from 2018 to 2019. Daily average concentrations of ambient air pollutants (PM2.5, PM10, SO2, NO2, and O3) were acquired from a high-resolution air quality dataset in China from 2013 to 2018. We used a logistic regression model to examine the associations between DR risk and long-term air pollution at various exposure windows. A total of 2405 out of the 8211 participants were diagnosed with diabetes, among whom 183 had DR. Ambient air pollution, especially particulate matter (i.e., PM2.5 and PM10) and NO2 were positively associated with DR prevalence among all the study subjects. Ambient SO2 and O3 concentrations were not associated with DR prevalence. PM2.5 and NO2 seemed to be borderline significantly associated with increased prevalence of DR in subjects with DM, especially under the model adjusted for sex, age, BMI, SBP, and DBP. These findings showed that long-term exposure to ambient particulate matter and NO2 was associated with a high DR risk in Fujian province, where ambient air pollution is relatively low.