Serum cadmium levels are independently associated with endothelial function in hemodialysis patients

Hemodialysis (HD) patients are at risk of deficiency of essential trace elements and excess of toxic trace elements. The aim of the study was to evaluate the relation between the serum levels of some trace elements and heavy metals (iron, zinc, manganese, copper, magnesium, cobalt, cadmium, and lead) and endothelial function in HD patients. Forty-eight chronic HD patients without known atherosclerotic disease and 42 age- and sex-matched healthy individuals were included in the study. The serum levels of trace elements (iron, zinc, manganese, copper, and magnesium) and heavy metals (cobalt, cadmium, and lead) were measured by Atomic Adsorption Spectrophotometer (UNICAM-929). The serum levels of iron, zinc, and manganese were lower, and levels of copper, magnesium, cobalt, cadmium, and lead were higher in HD patients compared to controls. Flow-mediated dilatation (FMD %) in HD patients was lower than that in the control group (7.27 +/- A 0.76 vs. 11.29 +/- A 0.82, P < 0.001). There was a significant negative correlation between FMD % and serum levels of cobalt (r = -0.313, P = 0.03) and cadmium (r = -0.524, P < 0.01). A linear regression analysis showed that serum cadmium levels were still significantly and negatively correlated with FMD % (regression coefficient = -0.526, P < 0.001). We first demonstrated that serum cadmium levels independently predict endothelial function in HD patients without known atherosclerotic disease.