Environmental Nickel Exposure and Cardiovascular Disease in a Nationally Representative Sample of U.S. Adults

BACKGROUND: Laboratory studies have linked nickel with the pathogenesis of cardiovascular disease (CVD); however, few observational studies in humans have confirmed this association. OBJECTIVE: This study aimed to use urinary nickel concentrations, as a biomarker of environmental nickel exposure, to evaluate the cross-sectional association between nickel exposure and CVD in a nationally representative sample of U.S. adults. METHODS: Data from a nationally representative sample (n = 2702) in the National Health and Nutrition Examination Survey 2017–20 were used. CVD (n = 326) was defined as self-reported physicians’ diagnoses of coronary heart disease, angina, heart attack, or stroke. Urinary nickel concentrations were determined by inductively coupled plasma mass spectrometry. Logistic regression with sample weights was used to estimate the odds ratios (ORs) and 95% confidence intervals (CIs) of CVD. RESULTS: Urinary nickel concentrations were higher in individuals with CVD (weighted median 1.34 μg/L) compared to those without CVD (1.08 μg/L). After adjustment for demographic, socioeconomic, lifestyle, and other risk factors for CVD, the ORs (95% CIs) for CVD compared with the lowest quartile of urinary nickel were 3.57 (1.73–7.36) for the second quartile, 3.61 (1.83–7.13) for the third quartile, and 2.40 (1.03–5.59) for the fourth quartile. Cubic spline regression revealed a non-monotonic, inverse U-shaped, association between urinary nickel and CVD (P(nonlinearity) < 0.001). CONCLUSIONS: Nickel exposure is associated with CVD in a non-monotonic manner among U.S. adults independent of well-known CVD risk factors. SUPPLEMENTARY INFORMATION: The online version contains supplementary material available at 10.1007/s12403-023-00579-4.