Association of Glutathione peroxidase 1 (GPX-1) activity with severity of coronary artery diseases

Abstract

Glutathione Peroxidase 1 (GPX-1) is a seleniumdependent enzyme with antioxidant properties. Studies have shown that the GPX-1 isoenzyme of Glutathione Peroxidase (GPX) appear to be a more sensitive indicator of oxidative stress in the pathogenesis of atherosclerosis and reperfusion injury. Limited evidence is available regarding the relevance of GPX-1 activity on human coronary artery disease and its severity. A case control study was carried out with age and sex matched patients with CAD (cases) and healthy subjects (controls). Patients awaiting coronary angiography were selected as cases. Blood samples were collected from the patients (n=60, mean age 54 ± 9 years, 45 Male, 15 Female) before coronary angiography. Sixty clinically healthy age and sex matched volunteers attending health screening programme were selected as controls. Angiogram findings were used to calculate vessel score which indicates the number of coronary arteries with ? 70% stenosis based on a method described by Sullivanet al in 1990. Angiogram positive cases had significantly low (p < 0.05) GPX-1 activity (mean 103.2 ± 33.0 U/L) than controls (mean 165.2 ± 43.0 U/L). The mean GPX-1 activity of cases were low in single vessel disease (101.2 ± 32.7 U/L) compared to those with double vessel disease (102.1 ± 33.3 U/L) and triple vessel disease (111.2 ± 37.1 U/L) respectively. There was a significant correlation between GPX-1 activity and vessel score groups (r = 0.536, p = 0.000). This study reveals that erythrocyte GPX-1 activity would be helpful in assessing the severity of CAD.