Effects of hemodialysis period on levels of blood trace elements and oxidative stress

As a treatment method for chronic renal failure (CRF), hemodialysis (HD) alters inorganic components containing trace elements. It was shown that decreased renal function is accompanied by insufficient antioxidant systems and/or increased free oxygen radicals. In this study, we aimed to investigate the effects of HD on trace element levels and oxidative stress markers. We included 111 CRF patients on HD treatment three times a week and 24 healthy controls. Patients were divided into four groups according to HD duration. Plasma malondialdehyde (MDA), protein carbonyls and total sulfhydryl (-SH) levels, zinc (Zn), copper (Cu), and magnesium (Mg) levels, and erythrocyte superoxide dismutase (SOD) activity were measured from blood taken from patients before HD. SH levels and SOD activity in all groups were significantly lower than those in the control group (p < 0.001). All groups had significantly higher plasma MDA levels than did controls (p < 0.001). Whereas there was no significant difference in -SH levels and SOD activity between groups, increased periods of HD were associated with increases in MDA. MDA levels of the third and fourth groups were significantly higher than in the first and second groups (p < 0.05, p < 0.001, respectively). There was no significant difference of Zn, Cu, Mg, and protein carbonyl levels in and between all groups. However, plasma Cu levels and MDA concentrations were correlated (r = 0.26, p < 0.01). Prolonged exposure to HD can cause increased oxidative damage but has no effect on trace element concentration.