ABSTRACT NUMBER: ESOC2026LT54 ASSOCIATION OF LONG-TERM EXPOSURE TO PM2.5 AND ITS COMPONENTS WITH CAROTID ATHEROSCLEROSIS IN CENTRAL CHINA:EVIDENCE FROM A PROSPECTIVE COHORT STUDY

Abstract Background and aims Epidemiological evidence linking fine particulate matter (PM2.5) chemical constituents to carotid atherosclerosis (CAS) remains limited, particularly in rapidly urbanizing regions of China. Methods A total of 33,091 participants from the Henan Carotid Atherosclerosis and Cardiovascular Disease Prospective Cohort were included. Three-year averaged concentrations of PM2.5 mass and its components (black carbon (BC), ammonium (NH4+), nitrate (NO3-), organic matter (OM) and inorganic sulfate (SO42-) were estimated by a hybrid satellite model. Generalized linear model was applied to explore the associations of PM2.5 and its constituents with prevalence of increased carotid intima–media thickness (cIMT), carotid plaque (CP), carotid stenosis (CS), and overall CAS. Quantile-based g-computation were employed to specify the most responsible constituents. Results Per 1 standard deviation (SD) increase in PM2.5 mass, the adjusted odds ratio (OR) and 95% confidence interval (CI) were 1.111 (95% CI: 1.085-1.138) for increased cIMT, 1.124 (95% CI: 1.094-1.154) for CP, and 1.689 (95%CI: 1.590-1.814) for CS. Significant positive associations were also observed for multiple PM2.5 components. For overall CAS, the adjusted OR per 1 SD increase were 1.107 for PM2.5 mass, 1.099 for BC, and 1.051 for SO₄2-. Mixture analyses identified BC and SO₄2- as the dominant contributors to the combined PM2.5 effect. Conclusions Long-term exposure to PM2.5 and its chemical components, particularly BC and SO42-, were associated with an increased prevalence of CAS in central China. These findings underscore the importance of PM2.5 composition in atherosclerotic cardiovascular risk and have implications for targeted air pollution control strategies. Conflict of interest