Selenium and Lead Exposure are Associated with Elevated Blood Pressure in Individuals with Undiagnosed Hypertension: Findings from NHANES 2013-2020.

PURPOSE: Prior studies on the relationship between metal exposure and blood pressure have reported inconsistent findings, potentially due to the inclusion of individuals receiving hypertension treatment. This study assessed the association between blood concentrations of selenium (Se), lead (Pb), total mercury (Hg), cadmium (Cd), and manganese (Mn) and elevated blood pressure in US adults aged 20-60 years without a prior hypertension diagnosis. We also explored the moderating effects of age, gender and body mass index (BMI), and the mediating role of non-high-density lipoprotein cholesterol (non-HDL-C).

METHODS

Data from the 2013-2020 National Health and Nutrition Examination Survey were analyzed. Weighted logistic regression model were used to estimate odds ratios (ORs) and 95% confidence intervals (CIs), with subgroup analyses assessing effect modification. Structural equation modelling was employed to evaluated the potential mediating effects of non-HDL-C.

RESULTS

Among 6026 participants, 1,569 had elevated blood pressure. Adjusted analyses showed significant associations between Se and Pb and increased hypertension odds. Each 1 μg/L increase in Se corresponded to a 1% rise in odds (OR: 1.01, 95% CI: 1.00, 1.01), with those in the highest Se quintiles (Q4 and Q5) having 49% (95% CI: 1.01-2.21) and 52% (95% CI: 1.01-2.27) greater odds, respectively. A unit increase in log-transformed Pb was associated with a 36% increase in odds (95% CI: 1.09-1.71), with the highest Pb quintile showing nearly double the risk (OR: 1.94; 95% CI: 1.22-3.07). BMI significantly moderated the association with Se and Pb, albeit in different ways. Non-HDL-C mediated 36.82% of Se's and 30.80% of Pb's total effect on elevated blood pressure (p<0.05).

CONCLUSION

In US adults without diagnosed hypertension, higher blood Se and Pb concentrations were associated with elevated blood pressure, with BMI modifying and non-HDL-C potentially and partially mediating these associations. These findings highlight the need for targeted public health strategies to limit environmental metal exposure and suggest that monitoring non-HDL-C levels in conjunction with individual metabolic profiles may support early cardiovascular risk assessment and timely intervention.