Exposure to perchlorate, nitrate and thiocyanate was associated with the prevalence of cardiovascular diseases

Aims: To determine the association between urinary levels of perchlorate, nitrate and thiocyanate, and the prevalence of cardiovascular diseases (CVD) among general population. Methods: A total of 16, 570 participants were enrolled from the National Health and Nutrition Examination Surveys (NHANES). Urinary levels of perchlorate, nitrate and thiocyanate were measured using ion chromatography coupled with electrospray tandem mass spectrometry. Multivariable linear regressions and logistic regressions were performed to explore the associations of exposure to perchlorate, nitrate and thiocyanate, and the prevalence of total and specific CVD, including chronic heart failure (CHF), coronary heart disease (CHD), angina, heart failure and stroke. Restricted cubic splines were used to explore the nonlinearity. Results: Participants with CVD had a lower urinary level of nitrate and thiocyanate (all P < 0.001). A null association between urinary perchlorate and total CVD or specific CVD was observed. Comparing with the lowest quartile, the highest quartile of urinary nitrate was independently associated with a decreased presence of total CVD (odds ratio [OR] 0.66, 95% confidence interval [CI] [0.53, 0.82]), CHF (OR 0.48, 95% CI [0.33, 0.71]), and stroke (OR 0.63, 95%CI [0.45, 0.88]). In addition, per one-fold increasement of urinary nitrate decreased a 0.15-fold prevalence of total CVD, 0.29-fold prevalence of CHF, and 0.16-fold prevalence of stroke. However, for urinary thiocyanate, we found that the 2nd and 3rd quartile were associated with total CVD, the 2nd quartile associated with heart attack, and the 2nd, 3rd and 4th quartile associated with stroke. What's more, restricted cubic splines confirmed that the relation between urinary nitrate and CVD was linear (P for nonlinearity = 0.242) and the inverse relation between urinary thiocyanate and CVD was nonlinear (P for nonlinearity < 0.001). Conclusion: In the general population, low levels of nitrate were linearly while thiocyanate were nonlinearly associated with an increased presence of cardiovascular diseases.