Blood Selenium Levels and Vascular Hemodynamics Interactions Vary by Age in US Adults

Selenium (Se), an essential micronutrient, is potentially implicated in cardiovascular health; we hypothesized that due to Se’s established antioxidant properties and effects on nitric oxide (NO) bioavailability, Se blood serum levels may influence vascular hemodynamics.1 There is conflicting evidence on the relationship between Se and blood pressure and very limited evidence regarding the relationship between Se levels and early markers of vascular change such as pulse wave velocity (PWV) and mean arterial pressure (MAP). To clarify this association, we evaluated the relationship of serum Se with vascular parameters in a nationally representative US sample.

METHODS:

We conducted a cross-sectional analysis using data from seven NHANES cycles (2003-04 and 2011–23). Participants (n=21,793) aged ≥18 years with blood Se and blood pressure data were included. Participants were classified by age groups (18–35, 36–65, >65 years) and Se quartiles. Vascular measures included systolic and diastolic blood pressure (SBP, DBP), pulse pressure (PP), mean arterial pressure (MAP), and estimated pulse wave velocity (ePWV). Blood Se was measured by mass spectrometry.

RESULTS:

In fully adjusted models, participants in the highest Se quartile had significantly higher SBP (coefficient=1.76 mmHg; 95%CI: 0.76-2.75; p=0.001), DBP (coefficient=2.12 mmHg; 95CI:1.38-2.86; p<0.001), MAP (coefficient=2.00 mmHg; 95%CI:1.29-2.70; p<0.001), and ePWV (coefficient=0.13 m/s; 95%CI:0.08-0.18; p<0.001) compared with the lowest quartile; there was no relationship with PP. Age modified the association between Se and vascular hemodynamics (Figure) such that adults>65years had lower SBP, PP, MAP, and ePWV than adults>18-35 years (interaction p-values = 0.003, 0.04, 0.01, 0.005 respectively).

CONCLUSIONS:

Our findings highlight that the relationship between Se and vascular hemodynamics is modified by age. The mechanisms responsible for these opposite effects of Se on vascular hemodynamics by age need further study.