Effect of oxidative stress on antioxidant enzyme activities, homocysteine and lipoproteins in chronic kidney disease.

BACKGROUND: Our aim was to determine the association of paraoxonase (PON1), superoxide dismutase (SOD) and catalase (CAT) activities and malondialdehyde (MDA) concentration, with lipoprotein and homocysteine (Hcy) concentrations in chronic kidney disease (CKD).

METHODS: We examined 60 patients with CKD (35 men and 25 women), aged 52.7 -/+ 3.1 years, and 60 age-, sex- and body mass index (BMI)-matched control subjects. Serum PON1 activity, levels of lipoproteins, Hcy and MDA were evaluated; SOD and CAT activities in erythrocytes were also investigated.

RESULTS: Levels of MDA, lipoprotein (a) (Lp(a)) and Hcy were significantly higher, while PON1 activity was lower in CKD than in controls (p<0.001). There were no significant differences between the patients and controls in the SOD and CAT activities (p>0.05). Levels of high-density lipoprotein cholesterol (HDL-C) and apolipoprotein A-I (ApoA-I) were lower in CKD than in controls (p<0.001), whereas total cholesterol (T-Chol) and triglyceride (TG) levels showed no significant difference between the groups. Levels of apolipoprotein B (ApoB) and low-density lipoprotein cholesterol (LDL-C) were higher in CKD than in controls (p<0.001). In CKD, PON1 activities were correlated with levels of Hcy, MDA, HDL-C, Lp(a) and ApoA-I. A significant positive correlation was found between levels of Hcy and Lp(a).

CONCLUSIONS: The results of this work suggest that patients with CKD exhibit an oxidant-antioxidant imbalance which is closely related to high levels of atherosclerotic risk factors.