Association between air pollution and cardiovascular disease risk in middle-aged and elderly individuals with diabetes: inflammatory lipid ratio accelerate this progression.

Background: Long-term exposure to air pollution significantly increases the risk of cardiovascular disease (CVD); however, the association and underlying mechanisms in individuals with diabetes remain unconfirmed.

Methods: We used data from the China Health and Retirement Longitudinal Study (CHARLS) to follow 5,430 adults over a four-year period. Baseline CVD and diabetes status were determined, and high-resolution data were used to assess air pollution exposure to PM₁, PM_2.5, PM₁₀, and O₃. The inflammatory lipid ratio (ILR) was calculated to reflect inflammatory and lipid metabolic states. A generalized linear model (GLM) was employed to analyze the effects of air pollution and ILR on diabetes-related CVD risk.

Results: The prevalence of CVD was 8.5% in the healthy population and 13.8% in the diabetic population. Air pollution exposure was significantly associated with an increased risk of CVD among diabetic individuals. For each interquartile range (IQR) increase in concentrations of pollutants O₃, PM₁, PM₁₀, and PM_2.5, CVD risk in the diabetic group rose by 21%, 19%, 28%, and 19%, respectively. Higher ILR values were positively associated with CVD incidence (OR = 1.019, 95% CI: 1.001-1.037, P < 0.05), with a nonlinear relationship observed between ILR levels and CVD risk (P_Nonlinear = 0.0381), indicating that higher ILR values exacerbate the impact of air pollution on diabetic individuals.

Conclusion: Among middle-aged and older adults with diabetes, exposure to air pollution is associated with an increased risk of CVD, and ILR intensifies this process. Therefore, implementing effective public health interventions to reduce air pollution exposure in diabetic populations is essential.