Air pollutants up risk of MASLD

Metabolic signatures of PM_2.5, PM₁₀, NO₂ and NO_x appear to contribute to a higher risk of metabolic dysfunction-associated steatotic liver disease (MASLD), suggests a study.

The analysis included 244,842 participants from the UK Biobank and identified 87, 65, 76, and 71 metabolites as metabolic signatures of PM_2.5, PM₁₀, NO₂, and NO_x, respectively.

These metabolic signatures significantly correlated with MASLD risk: PM_2.5 (hazard ratio [HR], 1.10, 95 percent confidence interval [CI], 1.06–1.14), PM₁₀ (HR, 1.06, 95 percent CI, 1.02–1.10), NO₂ (HR, 1.24, 95 percent CI, 1.20–1.29), and NO_x (HR, 1.14, 95 percent CI, 1.10–1.19).

Furthermore, all pollutants appeared to contribute to a higher risk of MASLD: PM_2.5 (HR, 1.03, 95 percent CI, 1.01–1.05), PM₁₀ (HR, 1.02, 95 percent CI, 1.01–1.04), NO₂ (HR, 1.01, 95 percent CI, 1.01–1.02), and NO_x (HR, 1.01, 95 percent CI, 1.00–1.01).

In Mendelian randomization (MR) analysis, MASLD remained associated with PM_2.5, NO₂ and NO_x-related metabolic signatures. 

“These signatures mediated the increased risk of MASLD associated with PM_2.5, PM₁₀, NO₂ and NO_x,” the researchers said.

Data from the UK Biobank were used in this study. Using bilinear interpolation, the researchers examined the annual mean concentrations of PM_2.5, PM₁₀, NO₂ and NO_x for each participant. They also identified metabolites associated with four air pollutants and constructed metabolic signatures using the elastic net regression model.

Cox models were used to explore the relationships between air pollutants, metabolic signatures, and MASLD risk, while MR analysis was used to analyse the potential causality. Finally, the researchers conducted a mediation analysis to assess the role of these metabolic signatures in the association between air pollutants and MASLD.