SYSTEMATIC REVIEW article
Front. Public Health
Sec. Environmental Health and Exposome
Volume 13 - 2025 | doi: 10.3389/fpubh.2025.1606959
Association between air pollution and risk of non-alcoholic fatty liver disease: an updated meta-analysis
Provisionally accepted
- 1Dongzhimen Hospital, Beijing University of Chinese Medicine, Beijing, China
- 2Beijing University of Chinese Medicine, Beijing, Beijing Municipality, China
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Objective: Air pollution is a major environmental risk to human health, with increasing evidence linking it to non-alcoholic fatty liver disease (NAFLD). However, findings remain inconsistent. This meta-analysis aimed to assess the relationship between air pollutants and the risk of NAFLD. Methods: PubMed, Embase, and Web of Science were systematically searched for studies published up to March 20, 2025. A random effects model was used to estimate combined odds ratios (ORs) and 95% confidence intervals (95% CIs). Subgroup analysis, sensitivity analysis, funnel plots, and Egger's test were conducted. Results: A total of 12 studies, including 49,549,903 participants (published between 2022 and 2024), were analyzed. For each 10 μg/m³ increase in pollutants, the ORs were 1.22 (1.16-1.29) for particulate matter with aerodynamic diameter ≤ 2.5 μm (PM2.5), 1.15 (0.95-1.40) for particulate matter between 2.5 μm and 10 μm in aerodynamic diameter (PM2.5-10), and 1.07 (1.01-1.13) for particulate matter with aerodynamic diameter ≤ 10 μm (PM10). For gaseous pollutants, the ORs were 1.45 (0.92-2.28) for sulfur dioxide (SO2) and 1.10 (1.06-1.14) for nitrogen dioxide (NO2). No notable connection emerged between ozone (O3) or carbon monoxide (CO) and NAFLD. Subgroup analysis revealed stronger associations for PM2.5, PM10, and NO2 with NAFLD in developed countries, Europe, and cohort studies, compared to developing countries, Asia, and cross-sectional studies. Conclusion: This analysis supports a positive relationship between air pollution and NAFLD risk. Geographic region and economic development appear to moderate this association.
Keywords: Air Pollution, Particulate Matter, Non-alcoholic fatty liver disease, Systematic review, Meta-analysis
Received: 06 Apr 2025; Accepted: 28 Jul 2025.
Copyright: © 2025 Zhang, Yang, Lanshuo, Tan, Li, Chai and Ru. This is an open-access article distributed under the terms of the Creative Commons Attribution License (CC BY). The use, distribution or reproduction in other forums is permitted, provided the original author(s) or licensor are credited and that the original publication in this journal is cited, in accordance with accepted academic practice. No use, distribution or reproduction is permitted which does not comply with these terms.
* Correspondence:
Xianzhao Yang, Dongzhimen Hospital, Beijing University of Chinese Medicine, Beijing, China
Shuying Ru, Dongzhimen Hospital, Beijing University of Chinese Medicine, Beijing, China
Disclaimer: All claims expressed in this article are solely those of the authors and do not necessarily represent those of their affiliated organizations, or those of the publisher, the editors and the reviewers. Any product that may be evaluated in this article or claim that may be made by its manufacturer is not guaranteed or endorsed by the publisher.