Increased membrane lipid peroxidation and decreased Na+/K+-ATPase activity in erythrocytes of patients with stable coronary artery disease.

Objectives: We aimed to determine erythrocyte membrane lipid peroxidation levels and Na/K-ATPase activity in patients with and without coronary artery disease (CAD) documented by coronary angiography.
Design and Methods: A total of 144 patients who had undergone coronary angiography were divided into a CAD group (n=82) and a non-CAD group (control group, n=62) according to the results of coronary angiography. Lipid peroxide levels in plasma and the erythrocyte membrane were measured using a fluorimetric method. Total antioxidant status and Na/K-ATPase activity in plasma were determined using spectrophotometric methods.
Results: Lipid peroxidation levels were significantly higher in the erythrocyte membrane of CAD patients compared with controls, whereas Na/K-ATPase activity was significantly lower in the erythrocyte membrane of CAD patients compared with controls. The coronary artery scores were correlated positively with membrane lipid peroxidation (r=0.324, P<0.001) and negatively with Na/K-ATPase activity (r=-0.302, P<0.001).
Conclusion: This study shows that the levels of membrane lipid peroxidation and Na/K-ATPase activity are correlated with the severity of CAD.