Associations between personal fine particulate matter elemental constituent mixtures and blood lipid profiles: A panel study in Chinese people aged 60-69 years

BACKGROUND AND AIM Dyslipidemia may be a potential mechanism linking Fine Particulate Matter (PM2.5) to adverse cardiovascular outcomes. However, the associations between PM2.5 and blood lipid have been inconsistent and the joint effect of PM2.5 elemental constituent on lipid profiles and the role of each constituent are still unclear. We aims to investigate the overall associations of PM2.5 elemental constituent with lipid parameters, and assess the relative importance of each constituent for lipid parameters. METHODS Sixty-nine older individuals were visited between September 2018 and January 2019 with five repeated measurements (237 blood samples in total). Each participant wore a PM2.5 monitor for 72 hours before each health examination, including a questionnaire survey, physical examination, and biological sample collection. Bayesian kernel machine regression (BKMR) model was implemented to estimate the joint effect of the seventeen elemental constituent on various lipid parameters. RESULTS We found that significant increases in total cholesterol (TC), lowdensity lipoprotein cholesterol (LDL-C), and non-high-density lipoprotein cholesterol (non-HDL-C) levels in older adults when exposed to the mixture of PM2.5 elemental constituents. Copper and titanium had higher posterior inclusion probabilities than the other constituents ranging from 0.76 to 0.90 and 0.74 to 0.94. Copper and titanium in the PM2.5 elemental constituent mixture played a significant role in the changes observed in the blood lipid profiles. CONCLUSIONS This study highlights the importance of identifying critical hazardous PM2.5 constituents that may cause adverse cardiovascular outcomes in the future. KEYWORDS PM2.5 constituents; Lipid parameters; Personal exposure monitoring; Complex mixtures；BKMR models