Metal exposure is associated with cognitive function and plasma sTrem2 levels in coal miners: a cross-sectional study.

BACKGROUND

Mild Cognitive Impairment (MCI) is an early stage of Alzheimer's disease, making its identification crucial. Occupational exposure to mixed environmental pollutants may contribute to cognitive decline, but the relationship between MCI and metal mixtures is not well understood, particularly in coal miners. Research is emerging on the connection between plasma levels of Triggering Receptor Expressed on Myeloid Cells 2 (sTrem2) and cognitive function, but the relationship between plasma sTrem2 and cognitive function warrants further exploration.

OBJECTIVES

This study evaluates the association between urinary metallic mixtures and MCI in coal miners and investigates the potential of plasma sTrem2 as a biomarker for cognitive function assessment.

METHODS

376 participants were assessed for urine concentrations of 16 metals and plasma levels of sTrem2, Neurofilament Light Chain (NfL), and phosphorylated Tau (p-tau181), alongside cognitive function using the MoCA. Binary logistic regression and restricted cubic spline (RCS) modeling were used for individual metal associations with cognitive function, while Bayesian Kernel Machine Regression (BKMR) and Quantile G-computation (QG-C) were used to evaluate the overall impact of metal mixtures.

RESULTS

Logistic regression revealed significant associations between various metals and cognitive function, with the RCS model indicating a dose-response relationship. The BKMR model showed that MCI incidence increases with higher total metal concentrations in urine. Additionally, interactions between metals were noted. The QG-C model indicated that zinc had the highest positive weight among metals, while cobalt, iron, and arsenic had the highest negative weights. Increased metal concentrations correlated with declines in plasma sTrem2, NfL, and p-tau181 levels, and reductions in sTrem2 were tied to lower cognitive function scores.

CONCLUSION

Cognitive decline in coal miners is associated with elevated metal exposure, and plasma sTrem2 levels decrease as urinary metal concentrations increase. More research is necessary to determine if plasma sTrem2 can be a precise biomarker for cognitive decline.