Association between circulating selenium levels and arterial stiffness: a nationwide cross-sectional study

Background: Atherosclerotic cardiovascular disease (ASCVD) is the leading cause of death worldwide. Arterial stiffness is an important pathological characteristic of ASCVD. Selenium (Se) may have a notable effect of arterial stiffness. However, the relationship between circulating Se (CSe) levels and arterial stiffness remains unclear. Methods: A total of 11 937 participants from the National Health and Nutrition Examination Survey (NHANES) from 2011 to 2018 were enrolled. The relationship between CSe levels, estimated pulse wave velocity (ePWV), and the atherogenic index of plasma (AIP) was evaluated using univariate and multivariate linear regression, dose-response, and mediation analyses. Results: A linear relationship between the CSe index and high AIP ( P for nonlinearity = 0.1) and a U-shaped relationship between the CSe index and high ePWV were found ( P for nonlinearity < 0.001). In fully adjusted models, the relationship between CSe and high AIP was positive (OR = 1.48, 95% CI: 1.20, 1.82; P = 0.001). An inflection point was found in the relationship between the CSe index and high ePWV. CSe levels of < 2.99 μmol/L were negatively related to high ePWV (OR = 0.71; 95% CI: 0.59, 0.86; P < 0.001). In contrast, CSe levels of ≥ 2.99 μmol/L were positively related to high ePWV (OR = 2.66; 95% CI: 1.66, 4.25; P < 0.001). Furthermore, the indirect effect mediated by the sex of CSe on high AIP was prominent (indirect effect = 0.006; 95% CI: 0.003, 0.008; percent mediation = 26.49%) in the fully adjusted models. Conclusions: Our findings suggests a significant relationship between CSe levels and arterial stiffness, the mechanism behind which should be further explored.