Reduced plasma zinc levels, lipid peroxidation, and inflammation biomarkers levels in hemodialysis patients: implications to cardiovascular mortality.

Despite the fact that low plasma zinc (Zn) levels play important roles in the oxidative stress, the relationships between lipid peroxidation and inflammation biomarkers with low plasma Zn levels have not been investigated in chronic kidney disease (CKD) patients. The aim of this study was to evaluate the Zn plasma levels, electronegative LDL [LDL(-)] levels, and inflammation markers as predictors of cardiovascular (CV) mortality in hemodialysis (HD) patients. Forty-five HD patients (28 men, 54.2 ± 12.7 years, 62.2 ± 51.4 months on dialysis and BMI 24.3 ± 4.1 kg/m(2)) were studied and compared to 20 healthy individuals (9 men, 51.6 ± 15.6 years, BMI 25.2 ± 3.9 kg/m(2)) and followed for 24 months to investigate the risks for CV mortality. LDL(-) levels were measured by ELISA, plasma Zn levels by atomic absorption spectrophotometry, C-reactive protein (CRP) level by immunoturbidimetric method, and tumor necrosis factor-α (TNF-α), interleukin-6 (IL-6), monocyte chemotactic protein-1 (MCP-1), and plasminogen activator inhibitor-1 (PAI-1) levels by a multiplex assay kit. HD patients presented low plasma Zn levels (54.9 ± 16.1 μg/dL) and high-LDL(-) (0.18 ± 0.12 U/L) and TNF-α (5.5 ± 2.2 pg/mL) levels when compared to healthy subjects (78.8 ± 9.4μ g/dL, 0.10 ± 0.08U/L, 2.4 ± 1.1 pg/mL, respectively, p < 0.05). Zn plasma levels were negatively correlated to TNF-α (r = -0.49; p = 0.0001) and LDL(-) (r = -0.33; p = 0.008). During the 2 years, 24.4% of the patients died, all due to CV disease. Analysis by the Cox model showed that high CRP, TNF-α, IL-6 levels, and long duration of HD were significant predictors of mortality. In conclusion, reduced Zn levels were associated with lipid peroxidation and inflammation, and we confirm here in a Brazilian cohort of HD patients that inflammation markers are strong predictors of CV death.