Associations of polycyclic aromatic hydrocarbons, water-soluble ions and metals in PM2.5 with liver function: Evidence from schizophrenia cohort

Abstract

Background: Fine particulate matter (PM_2.5) was reported to impact liver function, but the roles of specific PM_2.5 chemical components remained to be explored. Besides, severe liver dysfunction in schizophrenia patients deserves attention.

Objective: To investigate the associations of short-term PM_2.5 components with liver function in schizophrenia patients.

Methods: A repeated-measures study based on schizophrenia cohort including 1023 visits (n = 446) was conducted during 2017-2020. Liver function was reflected by 10 indicators including liver enzymes, proteins and bilirubin et al. Monitoring data of PM_2.5 and its components, including 16 polycyclic aromatic hydrocarbons (PAHs), 4 water-soluble ions and 10 metals were collected. Linear mixed effect and Bayesian kernel machine regression (BKMR) models were used to evaluate the single and combined effects of PM_2.5 components (0-3 day) on liver function in schizophrenia patients.

Results: Several PAHs were significantly associated with liver enzymes, while water-soluble ions and metal components had almost no association. Specifically, with per interquartile range (IQR) increased in Fluoranthene, levels of alkaline phosphatase (ALP), alanine transaminase (ALT), aspartate transaminase (AST) and gamma-glutamyl transpeptidase (GGT) increased by 2.06 %, 5.07 %, 4.94 % and 5.56 %, respectively. An IQR increases in Benzo[a]pyrene was significantly associated with 6.62 %, 3.67 % and 7.83 % increase in ALT, AST and GGT. Almost all PAHs, sulfate, nitrate, ammonium, Sb, Al, As, Pb, Mn and Tl were positively associated with albumin (ALB). Phenanthrene was associated with increased levels of direct bilirubin (DBIL) and total bilirubin (TBIL). The combined effects of significant PM_2.5 components on ALP, GGT, ALB, globulin (GLOB), ratio of albumin to globulin (A/G), TBIL and total bile acid (TBA) were found by BKMR, respectively.

Conclusions: Findings highlight the short-term combined effects of PM_2.5 components, especially PAHs, on liver function in schizophrenia patients, which contribute to the management of PM_2.5 sources including combustion activities and traffic emissions as well as improving schizophrenia comorbidities.

Keywords: Bayesian kernel machine regression; Liver function; PM(2.5) components; Particulate matter; Schizophrenia.