Relationship of long-term exposure to air pollutant mixture with metabolic-associated fatty liver disease and subtypes: A retrospective cohort study of the employed population of Southwest China

Chuanteng Feng; Bo Yang; Zihang Wang; Jiayi Zhang; Yao Fu; Bin Yu; Shu Dong; Hua Ma; Hongyun Liu; Honglian Zeng; Jan D Reinhardt; Shujuan Yang

doi:10.1016/j.envint.2024.108734

Relationship of long-term exposure to air pollutant mixture with metabolic-associated fatty liver disease and subtypes: A retrospective cohort study of the employed population of Southwest China

Environ Int. 2024 May 10:188:108734. doi: 10.1016/j.envint.2024.108734. Online ahead of print.

Authors

Chuanteng Feng¹, Bo Yang², Zihang Wang³, Jiayi Zhang⁴, Yao Fu³, Bin Yu¹, Shu Dong³, Hua Ma³, Hongyun Liu³, Honglian Zeng², Jan D Reinhardt⁵, Shujuan Yang⁶

Affiliations

¹ Institute for Disaster Management and Reconstruction, Sichuan University, Chengdu 610200, China; West China School of Public Health and West China Fourth Hospital, Sichuan University, Chengdu 610041, China.
² Department of Health Management Center, Clinical Medical College & Affiliated Hospital, Chengdu University, Chengdu 610106, China.
³ West China School of Public Health and West China Fourth Hospital, Sichuan University, Chengdu 610041, China.
⁴ Department of Rehabilitation Medicine, West China Hospital, Sichuan University, Chengdu 610041, China.
⁵ Institute for Disaster Management and Reconstruction, Sichuan University, Chengdu 610200, China; Department of Rehabilitation Medicine, Jiangsu Province Hospital/Nanjing Medical University First Affiliated Hospital, Nanjing 210009, China; Department of Health Sciences and Medicine, University of Lucerne, Lucerne 6002, Switzerland. Electronic address: reinhardt@scu.edu.cn.
⁶ West China School of Public Health and West China Fourth Hospital, Sichuan University, Chengdu 610041, China; Department of Health Management Center, Clinical Medical College & Affiliated Hospital, Chengdu University, Chengdu 610106, China; International Institute of Spatial Lifecourse Health (ISLE), Wuhan University, Wuhan 430079, China. Electronic address: yangsj@scu.edu.cn.

PMID: 38744043
DOI: 10.1016/j.envint.2024.108734

Abstract

Background: While evidence suggests that PM_2.5 is associated with overall prevalence of Metabolic (dysfunction)-Associated Fatty Liver Disease (MAFLD), effects of comprehensive air pollutant mixture on MAFLD and its subtypes remain unclear.

Objective: To investigate individual and joint effects of long-term exposure to comprehensive air pollutant mixture on MAFLD and its subtypes.

Methods: Data of 27,699 participants of the Chinese Cohort of Working Adults were analyzed. MAFLD and subtypes, including overweight/obesity, lean, and diabetes MAFLD, were diagnosed according to clinical guidelines. Concentrations of NO₃^-, SO₄^2-, NH₄⁺, organic matter (OM), black carbon (BC), PM_2.5, SO₂, NO₂, O₃ and CO were estimated as a weighted average over participants' residential and work addresses for the three years preceding outcome assessment. Logistic regression and weighted quantile sum regression were used to estimate individual and joint effects of air pollutant mixture on presence of MAFLD.

Results: Overall prevalence of MAFLD was 26.6 % with overweight/obesity, lean, and diabetes MAFLD accounting for 92.0 %, 6.4 %, and 1.6 %, respectively. Exposure to SO₄^2-, NO₃^-, NH₄⁺, BC, PM_2.5, NO₂, O₃and CO was significantly associated with overall MAFLD, overweight/obesity MAFLD, or lean MAFLD in single pollutant models. Joint effects of air pollutant mixture were observed for overall MAFLD (OR = 1.10 [95 % CI: 1.03, 1.17]), overweight/obesity (1.09 [1.02, 1.15]), and lean MAFLD (1.63 [1.28, 2.07]). Contributions of individual air pollutants to joint effects were dominated by CO in overall and overweight/obesity MAFLD (Weights were 42.31 % and 45.87 %, respectively), while SO₄^2- (36.34 %), SO₂ (21.00 %) and BC (12.38 %) were more important in lean MAFLD. Being male, aged above 45 years and smoking increased joint effects of air pollutant mixture on overall MAFLD.

Conclusions: Air pollutant mixture was associated with MAFLD, particularly the lean MAFLD subtype. CO played a pivotal role in both overall and overweight/obesity MAFLD, whereas SO₄^2- were associated with lean MAFLD.

Keywords: Air pollutant mixture; MAFLD; Metabolic dysfunction; Obesity; Ozone; PM(2.5) constituents.