Accumulating animal studies have demonstrated the harmful contribution of ambient air pollution (AP) to metabolic dysfunction-associated fatty liver disease (MAFLD), but corresponding epidemiological evidence is limited. We examined the associations between long-term AP exposure and MAFLD prevalence in a Chinese population. We conducted a cross-sectional study of 90,086 participants recruited in China from 2018 to 2019. MAFLD was assessed based on radiologically diagnosed hepatic steatosis and the presence of overweight/obese status, diabetes mellitus, or metabolic dysregulation. Residence-specific levels of air pollutants, including particulate matter with aerodynamic diameters of ≤1 μm (PM₁), ≤2.5 μm (PM_2.5), and ≤10 μm (PM₁₀), and nitrogen dioxide (NO₂), were estimated by validated spatiotemporal models. We used logistic regression models to examine the AP-MAFLD associations and further evaluated potential effect modifications by demographics, lifestyle, central obesity, and diabetes status. Increased exposure levels to all 4 air pollutants were significantly associated with increased odds of MAFLD, with odds ratios (ORs) of 1.13 (95% CI 1.10-1.17), 1.29 (1.25-1.34), 1.11 (1.09-1.14), and 1.15 (1.12-1.17) for each 10 μg/m³ increase in PM₁, PM_2.5, PM₁₀, and NO₂, respectively. Further stratified analyses revealed that individuals who are male, alcohol drinkers, and current and previous smokers, those who consume a high-fat diet, and those with central obesity experience more significant adverse effects from AP exposure than other individuals. This study provides evidence that long-term exposure to ambient PM₁, PM_2.5, PM₁₀, and NO₂ may increase the odds of MAFLD in the real world. These effects may be exacerbated by unhealthy lifestyle habits and central obesity. We conducted an epidemiological study on the potential effect of ambient air pollution on the risk of metabolic dysfunction-associated fatty liver disease (MAFLD) in approximately 90 thousand adults in China. We found that long-term exposure to ambient air pollution may increase the odds of MAFLD, especially in individuals who are male, smokers, and alcohol drinkers, those who consume a high-fat diet, and those with central obesity.

Non-communicable diseases (NCDs), such as cardiovascular disease, cancer, chronic respiratory disease and diabetes, have become leading causes of death worldwide. ^{1, 2} It is estimated that 63% of all global deaths are due to NCDs, ³ with an increasing contribution from low- and middle-income countries. The prevalence and incidence of NCDs are not evenly distributed between and within countries because of variations in environment, lifestyle, socio-economic position, genetic factors and access to health care services. ^{4, 5}

OBJECTIVE: Association between particulate matter with aerodynamic diameters ≤2.5 μm (PM2.5) components and diabetes remains unclear. We therefore aimed to investigate the associations of long-term exposure to PM2.5 components with diabetes. RESEARCH DESIGN AND METHODS: This study included 69,210 adults with no history of diabetes from a large-scale epidemiologic survey in Southwest China from 2018 to 2019. The annual average concentrations of PM2.5 and its components were estimated using satellite remote sensing and chemical transport modeling. Diabetes was identified as fasting plasma glucose ≥7.0 mmol/L (126 mg/dL) or hemoglobin A1c ≥48 mmol/mol (6.5%). The logistic regression model and weighted quantile sum method were used to estimate the associations of single and joint exposure to PM2.5 and its components with diabetes, respectively. RESULTS: Per-SD increases in the 3-year average concentrations of PM2.5 (odds ratio [OR] 1.08, 95% CI 1.01–1.15), black carbon (BC; 1.07, 1.01–1.15), ammonium (1.07, 1.00–1.14), nitrate (1.08, 1.01–1.16), organic matter (OM; 1.09, 1.02–1.16), and soil particles (SOIL; 1.09, 1.02–1.17) were positively associated with diabetes. The associations were stronger in those ≥65 years. Joint exposure to PM2.5 and its components was positively associated with diabetes (OR 1.04, 95% CI 1.01–1.07). The estimated weight of OM was the largest among PM2.5 and its components. CONCLUSIONS: Long-term exposure to BC, nitrate, ammonium, OM, and SOIL is positively associated with diabetes. Moreover, OM might be the most responsible for the relationship between PM2.5 and diabetes. This study adds to the evidence of a PM2.5-diabetes association and suggests controlling sources of OM to curb the burden of PM2.5-related diabetes.

Background In Western developed countries, food-based dietary patterns have been associated with the risk of cardiometabolic diseases, but little is known about such associations in less developed ethnic minority regions (LEMRs), where the cardiometabolic disease burden is growing rapidly and food patterns differ substantially.