Associations of metal mixtures with thyroid function and potential interactions with iodine status: results from a cross-sectional study in MEWHC

Environ Sci Pollut Res Int. 2023 Sep 16. doi: 10.1007/s11356-023-29682-4. Online ahead of print.ABSTRACTFew studies are available on associations between metal mixture exposures and disrupted thyroid hormone homeostasis; particularly, the role of iodine status was ignored. Here, we aimed to explore the cross-sectional relationship of blood cell metals with thyroid homeostasis and explore the potential modifying effect of iodine status. Among 328 workers from the manganese-exposed workers healthy cohort (MEWHC), we detected thyroid function parameters: thyroid stimulating hormone (TSH), total triiodothyronine (TT3), free triiodothyronine (FT3), total tetraiodothyronine (TT4), free tetraiodothyronine (FT4) as well as calculated sum activity of peripheral deiodinases (GD) and thyroid's secretory capacity (GT). Inductively coupled plasma mass spectrometry (ICP-MS) was used to measure 22 metal concentrations in blood cells. Based on the consistent results of least absolute shrinkage and selection operator (LASSO) and Bayesian kernel machine regression (BKMR) analyses, there were significant positive associations between copper and TSH (β = 2.016), iron and FT4 (β = 0.403), titanium and GD (β = 0.142), nickel and GD (β = 0.057), and negative associations between copper and FT4 (β = - 0.226), selenium and GD (β = - 0.332), among the participants. Interestingly, we observed an inverted-U shape relationship between magnesium and FT4. Furthermore, we found a synergistic effect be...
Source: Environmental Science and Pollution Research International - Category: Environmental Health Authors: Source Type: research