Association of air pollution with diabetic microvascular complications: A prospective cohort study

To investigate the association between long-term exposure to air pollution and the risk of microvascular complications in individuals with diabetes, and provide the evidence to inform environmental strategies for prevention.

The data were collected from UK Biobank cohort (n = 9,671). Kaplan-Meier curves and log-rank tests were used to compare cumulative incidence across exposure groups. Cox proportional hazards models were employed to evaluate the associations between air pollutant exposure and the development of microvascular complications, with adjusting for demographic, clinical, and biochemical covariates. Stratified and sensitivity analyses were conducted to assess the robustness of the findings. Additionally, restricted cubic splines were used to explore potential nonlinear relationships between pollutant concentrations and complication risk.

With a median follow-up time of 12.4 years, 2,104 participants (21.8%) developed microvascular complications. The Kaplan-Meier analysis demonstrated early divergence in cumulative incidence curves, suggesting an early impact of air pollution exposure on vascular outcomes. After multivariable adjustment, higher levels of air pollution exposure were significantly associated with increased risk of microvascular complications in patients with diabetes. Compared to the lowest quartile, participants in the highest quartile of exposure had elevated risks (NO2: HR = 1.27, 95% CI: 1.12-1.45; PM10: HR = 1.44, 95% CI: 1.27-1.64). These associations remained consistent across stratified and sensitivity analyses.

Long-term exposure to air pollutants, particularly NO2 and PM10, is associated with an increased risk of microvascular complications among individuals with diabetes. The observed risk appears to be persistent and may begin at relatively low exposure levels, underscoring the need for preventive strategies targeting environmental risk factors.