Co-exposure to Heavy Metals and Hypertension Among Adults in South Korea

The effect of exposure to metal mixtures on blood pressure or hypertension is still unclear. The purpose of this study was to assess the relationship between blood concentrations of lead (Pb), mercury (Hg), and cadmium (Cd), and blood pressure and the risk of hypertension among adults in South Korea. A nationwide population-based study was conducted using data from 10,566 participants aged 19 years and older collected in the 2010–2017 Korea National Health and Nutrition Examination Survey. Logistic regression was used to estimate the odds ratio for hypertension after adjustment for potential confounders. Weighted quantile sum (WQS) regression models were used to evaluate the association between blood concentrations of metal mixture and the risk of hypertension. Higher blood concentrations of Pb, Hg, or Cd were associated positively with increasing levels of blood pressure and the prevalence of hypertension (p for trend < 0.001). The increase in blood Pb concentration significantly increased the risk of hypertension. However, the correlation between blood Hg or Cd and the risk of hypertension showed different results depending on the adjustment of the covariates, including the concentration of metals concomitantly exposed to or the inclusion of subjects with a family history of hypertension. In the WQS regression analysis, the WQS index, wherein Pb was the most predominant, was found to be significantly and positively associated with hypertension. The findings of this study suggest that co-exposure to these three metals may collectively increase the risk of hypertension in Korean adults.