Exploring the relationship between air pollution, non-alcoholic fatty liver disease, and liver function indicators: a...

Area of Science:

• Environmental Health
• Hepatology
• Genetic Epidemiology

Background:

• Non-alcoholic fatty liver disease (NAFLD) is a prevalent metabolic disorder with rising global incidence.
• Existing research suggests a link between PM2.5 air pollution and NAFLD, but a causal relationship remains debated.
• Air pollution's impact on liver health requires further investigation.

Purpose of the Study:

• To investigate the causal relationship between major air pollutants and NAFLD using Mendelian randomization.
• To assess the association between air pollutants and key liver function indicators.
• To provide robust evidence on the etiological role of air pollution in NAFLD.

Main Methods:

• Mendelian randomization analysis utilizing large-scale genome-wide association study data from European populations.
• Evaluation of four common air pollutants (PM2.5, PM10, NO2, NOx) as exposures.
• Application of five statistical methods (IVW, Weighted median, MR-Egger, Simple mode, Weighted mode) with pleiotropy and heterogeneity testing.

Main Results:

• No statistically significant causal association was found between PM2.5, PM10, nitrogen dioxide, or nitrogen oxides and NAFLD.
• A significant causal relationship was identified between PM10 exposure and reduced serum albumin (ALB) levels (P=0.019, 95% CI=1.02-1.27).
• Sensitivity analyses confirmed the robustness of the findings regarding air pollutants and NAFLD.

Conclusions:

• Mendelian randomization analysis does not support a causal link between common air pollutants and NAFLD in European populations.
• Exposure to PM10 may causally influence serum albumin levels, suggesting an impact on the liver's protein synthesis capacity.
• Further research is warranted to explore the specific mechanisms linking PM10 to liver function markers.