Association between urinary concentrations of heavy metals and trace elements and renal function in Swiss adults: a cross-sectional study

Background/introduction Chronic kidney disease (CKD) is an important public health problem. Heavy metals and trace elements can affect kidney function; however, there are few studies on the association between heavy metals and trace elements and kidney function in the general population. Purpose To assess the associations between urinary concentrations of 23 elements (Li, Be, Al, V, Cr, Mn, Co, Ni, Cu, Zn, As, Se, Mo, Ag, Cd, Sn, Sb, Hg, Tl, Pb, Bi, Fe, and Iodine) and kidney function, evaluated by estimated glomerular filtration rate (eGFR). Methods Cross-sectional survey of 6204 adults (51.7% women, 52.4±10.7 years). Associations were assessed via Spearman correlation and pairwise comparisons. Concentration of the 23 elements was standardized to the urinary creatinine levels. Results Bivariate analysis showed that urinary Mn, Co, Ni, Zn, Cd, and Sn levels were negatively associated, and urinary V, As, Sb, Hg, Pb, and Iodine were positively associated with eGFR (see figure). There were 3224 (52%), 2809 (45.3%) and 171 (2.7%) participants with normal renal function, impaired renal function (IRF, defined as a eGFR between 60 and 90 ml/min/1.73 m²), and CKD (eGFR <60 ml/min/1.73 m²), respectively. After multivariable analysis, compared with participants with normal kidney function, participants with IRF and CKD had lower urinary V, Mn, Cu, Se, Mo, Ag, Cd, Hg, Tl, Pb and Bi levels (all P for trend <0.001). Conclusion Urinary heavy metals/trace elements are associated with kidney dysfunction. Further blood heavy metal/trace element analysis and prospective studies are needed to evaluate the potential risks of heavy metal/trace element exposure on kidney function. Matrix of bivariate correlations.