Association of mixed polycyclic aromatic hydrocarbons exposure with cardiovascular disease and the mediating role of inflammatory indices in US adults.

Background: Cardiovascular disease (CVD) is the leading cause of death worldwide. Few studies have investigated the effects of mixed polycyclic aromatic hydrocarbon (PAH) exposure on CVD prevalence. We aimed to evaluate the association between mixed PAHs exposure and CVD and determine the extent to which these links are mediated by inflammatory indices.

Methods: We used National Health and Nutrition Examination Survey (NHANES) data from 2003 to 2016. Adults with a diagnosis of CVD and seven monohydroxylated PAH metabolites (OH-PAHs) in their urine samples were included. Multivariate logistic regression and Bayesian kernel machine regression (BKMR) models were used to estimate the association between single and mixed PAHs exposure and CVD. Mediation analysis was used to evaluate the mediating effect of inflammatory indices on the association between PAHs mixtures and CVD.

Results: Here, 9136 individuals were included and 10.5% had CVD. Multivariate logistic regression analysis with all the OH-PAHs included that 2-hydroxyfluorene was found positively associated with increased odds of CVD. The BKMR analysis revealed that the overall effect of the seven PAH mixtures was positively associated with CVD. The univariate exposure-response function showed that 2-hydroxyfluorene was positively associated with CVD. Moreover, mediation analysis demonstrated that neutrophil-to-lymphocyte ratio and systemic immune inflammation index mediated the association between PAHs and CVD.

Conclusions: Our findings highlight the complexity of the association between mixed PAHs exposure and CVD. At the same time, our study provides insight into the potential mechanisms of inflammation as a mediator between exposure to PAH mixtures and CVD.