Background: Growing evidences have linked the exposure to heavy metals to the risk of type 2 diabetes (T2D), cardiovascular diseases (CVD), and chronic kidney disease (CKD). In the present analysis, we examined secular trends in levels of four toxic metals (arsenic (As), cadmium (Cd), lead (Pb), and mercury (Hg)) in urine among adults aged 20 years or above from nine cycles of National Health and Nutrition Examination Survey (NHANES 1999-2016).
Methods: We calculated the age- and sex-standardized geometric means of urinary metal levels, and further stratified them by comorbidities including T2D, CVD and CKD. Joint-point regression model was used to estimate trends over time.
Results: A total of 17,083 participants were included. Urinary Cd (4.35*10-2-3.70*10-2 μg/g creatinine; AAPC=-1.1, 95% CI= -1.5, -0.7), Pb (6.53-4.62 μg/g creatinine; AAPC=-2.2, 95% CI= -2.6, -1.9), Hg (6.58-3.80 μg/g creatinine; AAPC=-2.7, 95% CI= -3.6, -1.8) declined during 1999 and 2016, and urinary As (2.58-2.34 μg/g creatinine; AAPC=-0.9, 95% CI= -2.1, 0.2) declined during 2003 and 2016. When stratified by comorbidities, in 2009-2010, urinary As was higher among participants with T2D, CVD or CKD. Urinary Cd was higher among participants with T2D in the 2003-2004 survey, among participants with CVD in the 1999-2000 survey, and among participants with CKD in the 2007-2008 survey. In the 1999-2000 survey, urinary Pb was higher among participants with T2D, CVD or CKD. Urinary Hg was higher among participants with T2D in the 2005-2006 survey, among participants with CVD in the 2001-2002 survey, and among participants with CKD in the 1999-2000 survey.
Conclusion: The levels of toxic heavy metal in urine have inclined among U.S. adults in the past 18 year but the extent varied by comorbidities.
J. Yang: None. K. Lo: None. A. Yang: None.
