Association of inflammation mediated blood heavy metals with plasma atherogenic index: NHANES analysis 2015–2020

Metal pollutants are widespread in various environments, and numerous studies have indicated an association between metal exposure and the risk of atherosclerosis. However, the underlying mechanisms of this association remain unclear. The Atherogenic Index of Plasma (AIP), a biomarker for predicting cardiovascular events, reflects atherosclerosis risk and the severity of vascular stenosis. This study aimed to explore the relationship of single and combined metal exposure with AIP. Data from the 2015–2016 and 2017–2020 National Health and Nutrition Examination Survey (NHANES) were included to assess the mediating role of inflammation in adults. In single-metal models, a positive dose-response relationship was observed between blood selenium (Se) and AIP, while cadmium (Cd) and mercury (Hg) were negatively correlated with AIP. We employed Weighted Quantile Sum (WQS) regression and Bayesian Kernel Machine Regression (BKMR). In the WQS model, AIP significantly increased with rising mixed metal concentrations, a finding consistent and statistically significant in the BKMR model. Furthermore, mediation analysis indicated that high-sensitivity C-reactive protein (Hs-CRP) mediated 11.83% of the positive association between blood selenium and AIP, suggesting that inflammation may play a partial mediating role in the relationship between metal exposure and AIP. • First study linking mixed metal exposure to the Atherogenic Index of Plasma (AIP). • Selenium showed a significant positive dose-response relationship with AIP. • Inflammation (Hs-CRP) mediated 11.83% of the selenium-AIP association. • Weighted Quantile Sum and Bayesian Kernel Machine Regression models were employed. • Analyses were based on a nationally representative sample (NHANES 2015–2020).