Association between long-term exposure to fine particulate matter and diabetic retinopathy among diabetic patients: A national cross-sectional study in China

•This is a national-wide study conducted across the rural Chinese population.•The OR of PM2.5 for diabetic retinopathy was 1.41 (1.27, 1.57).•The effect of PM2.5 was stronger in participants with alcohol consumption.•A satellite-based spatiotemporal model was used to estimate PM2.5 levels. While the relationship between ambient air pollution and diabetes mellitus has recently been reported, data on the association between fine particulate matter (PM2.5) and diabetic complications are limited, especially in microvascular diseases such as diabetic retinopathy. To investigate the associations between long-term exposure to PM2.5 and the prevalence of diabetic retinopathy in adult diabetic patients in rural China. The study population was based on the Rural Epidemiology for Glaucoma in China (REG-China), a national cross-sectional survey conducted in rural China. This analysis selected diabetic patients with or without diabetic retinopathy. A satellite-based spatiotemporal model was used to estimate personal PM2.5 exposure. Logistic regression models were used to investigate the effect of long-term PM2.5 exposure on diabetic retinopathy. The analysis included 3111 diabetic participants, 329 of whom were diagnosed with diabetic retinopathy. The median level of exposure to PM2.5 from 2000 to2016 was 59.9 μg/m3. For each 10 μg/m3 increase in PM2.5, the adjusted odds ratio (95% confidence interval) for diabetic retinopathy was 1.41 (1.27, 1.57). In subgroup analyses, the effect of PM2.5 on diabetic retinopathy was significantly stronger in participants who self-reported alcohol consumption. These findings suggest that long-term exposure to high PM2.5 was associated with the risk of diabetic retinopathy among diabetic patients in rural China.