Nutr Metab Cardiovasc Dis. 2026 Jan 21:104573. doi: 10.1016/j.numecd.2026.104573. Online ahead of print.
ABSTRACT
BACKGROUND AND AIM: Evidence has linked long-term outdoor air pollution with cardiovascular disease (CVD), while potential causal relationships of air pollutant exposure with CVD and mediation roles of metabolic risk factors remain under-explored.
METHODS AND RESULTS: We evaluated time-weighted exposure to fine particulate matter (PM), ozone (O), and PM components among 21,102 participants from the CHCN-BTH cohort. Well-validated online databases, participants' outdoor activity durations, and pollutant infiltration factors were used to assess time-weighted exposure. We employed the targeted maximum likelihood estimation (TMLE) approach to estimate potential causal relationships between air pollutants and incident CVD. High-dimensional mediation analyses were used to further investigate the mediating roles of metabolic risk factors. Compared with exposures at first quartile concentration (Q1), participants in highest quartile of exposure (Q4) to air pollutants exhibited significantly increased risk of CVD incidence: PM (RR: 3.453, 95%CI: 2.674-4.460), warm-season O (1.332, 1.016-1.746), black carbon (BC) (4.885, 2.866-8.327), ammonium (NH+) (1.959, 1.378-2.785), nitrate (NO-) (1.679, 1.117-2.525), sulfate (SO2-) (2.860, 2.211-3.701), and organic matter (OM) (4.070, 2.283-7.253). High-dimensional mediation analysis indicates that high-density lipoprotein-cholesterol (HDL-C) played a mediating role in the total effects, accounting for 10.46%, 24.96%, 39.35%, and 24.74% of PM, BC, SO2-, and OM, respectively. Systolic blood pressure (SBP) mediated 13.41% of the total effect attributable to warm-season O.
CONCLUSIONS: This study provides potential causal linkage between air pollutants and CVD risk. Notably, our findings reveal roles of HDL-C and SBP in mediating the effects of CVD induced by air pollutant exposures.
PMID:41714214 | DOI:10.1016/j.numecd.2026.104573