Air pollution associate with advanced hepatic fibrosis among patients with chronic liver disease.

We aimed to investigate the association between air pollution and advanced fibrosis among patients with metabolic associated fatty liver disease (MAFLD) and chronic hepatitis B virus (HBV) and hepatitis C virus (HCV) infections. A total of 1376 participants who were seropositive for HBV surface antigen (HBsAg) or antibodies to HCV (anti-HCV) or had abnormal liver function in a community screening program from 2019 to 2021 were enrolled for the assessment of liver fibrosis using transient elastography. Daily estimates of air pollutants (particulate matter ≤2.5 μm in diameter [PM 2.5 ], nitrogen dioxide [NO 2 ], ozone [O 3 ] and benzene) were aggregated into mean estimates for the previous year based on the date of enrolment. Of the 1376 participants, 767 (52.8%) and 187 (13.6) had MAFLD and advanced fibrosis, respectively. A logistic regression analysis revealed that the factors associated with advanced liver fibrosis were HCV viremia (odds ratio [OR], 3.13; 95% confidence interval [CI], 2.05-4.77; p < 0.001), smoking (OR, 1.79; 95% CI, 1.16-2.74; p = 0.01), age (OR, 1.04; 95% CI, 1.02-1.05; p < 0.001) and PM 2.5 (OR, 1.10; 95% CI, 1.05-1.16; p < 0.001). Linear regression analysis revealed that LSM was independently correlated with PM 2.5 (β: 0.134; 95% CI: 0.025, 0.243; p = 0.02). There was a dose-dependent relationship between different fibrotic stages and the PM 2.5 level (the PM 2.5 level in patients with fibrotic stages 0, 1-2 and 3-4: 27.9, 28.4, and 29.3 μg/m 3 , respectively; trend p < 0.001). Exposure to PM 2.5 , as well as HBV and HCV infections, is associated with advanced liver fibrosis in patients with MAFLD. There was a dose-dependent correlation between PM 2.5 levels and the severity of hepatic fibrosis.