Multiple categories of polycyclic aromatic hydrocarbons in atmospheric PM2.5 associated with changes in lipid profiles: A longitudinal study in Beijing

Lipid disorder has been demonstrated to be a key biomarker for many chronic diseases, and PM2.5 is emerging as a risk factor for altered lipid profiles. However, few studies have focused on changes in comprehensive lipid indices caused by PM2.5-bound polycyclic aromatic hydrocarbon (PAH) exposure in the older adult population. The aim of this study was to investigate the relationship between multiple categories of PAHs and lipid profiles. This longitudinal study including 98 adults was conducted in Beijing, China, from November 2016 to January 2018. PAHs were analyzed using gas chromatography-mass spectrometry in the ion monitoring mode. Multiple categories of PAHs were classified as low-molecular-weight PAHs (LMW-PAHs), high-molecular-weight PAHs (HMW-PAHs), carcinogenic PAHs (c-PAHs) and noncarcinogenic PAHs (nc-PAHs) based on their molecular weights and carcinogenicity potentials. Linear mixed-effects models were used to explore the association between multiple categories of PAHs and lipid profiles, including single-pollutant, two-pollutant, and constituent residual models. High-density lipoprotein cholesterol (HDL-C) levels were significantly decreased by 1.00% (95% CI,-1.98% to-0.30%) to 9.52% (95% CI,-13.93% to-4.88%) in association with a 10-ng/m(3) increase in moving averages of the multiple categories of PAHs. In addition, significant increases in the total cholesterol (TG), castelli risk indices I and II (CRI-I and II), atherogenic coefficient (AC) and atherogenic index of plasma (AIP) of 2.02% (95% CI, 0.10%-5.13%) to 40.49% (95% CI, 13.88%-73.33%) were found, associated with a 10ng/m(3) increase in multiple categories of PAHs. Our findings suggest that exposure to multiple categories of PAHs may disturb proatherogenic lipid profiles. Further studies are needed to investigate the potential mechanism by which PAHs disturb lipid metabolism.