Studies on oxidative stress, serum iron and iron binding capacity in subjects prone to the risk of coronary artery disease

Abstract

Lipid peroxidation in vitro and in vivo has been postulated to be involved in the development of atherosclerosis. It is also known that free iron catalyses the lipid peroxidation. Therefore, we assessed the status of oxidative stress in smokers, hypertensives and non-insulin dependent subjects, who were prone to coronary artery disease. In addition, superoxide dismutase levels and iron binding capacity were also measured to know their antioxidant defences. One hundred seventy-five consecutive subjects below 60 years of age were examined; they were then divided into three groups: one with coronary artery disease, another without coronary artery disease and a healthy control group. The patients having either of the one risk factors for coronary artery disease i.e. smoking, hypertension and/or diabetes were studied. Serum lipid peroxides, superoxide dismutase, serum iron and iron binding capacity were estimated. Oxidative stress was highest in smokers with coronary artery disease (3.11+/-0.79 mmol/ml) as compared to hypertensives (2.69+/-0.20 mmol/nl) and non-insulin dependent diabetics (2.78+/-0.19 mmol/ml). Superoxide dismutase activity was also significantly decreased (p<0.001) in smokers with coronary artery disease as compared to hypertensives and non-insulin dependent diabetes mellitus. Final step of stepwise logistic regression based on malondialdehyde and superoxide dismutase correctly predicted coronary artery disease status in 90 percent smokers. Serum iron and total iron binding capacity were not significantly different in risk prone subjects. However, among all risk prone subjects, smokers with coronary artery disease showed highest serum iron levels and decreased iron binding capacity.