Abstract
An imbalance between oxidative damage and antioxidative protection in association with the pathophysiology of atherosclerosis has been suggested. The aim of our study was to investigate the relationship between plasma lipids, the antioxidant system and oxidative damage in Thai patients with stable coronary artery disease (CAD). Sixty‐one patients (40 males, 21 females), who were angiographically defined as having CAD and were clinically stable, participated in this study. Thirty‐two healthy subjects (20 males, 12 females) served as normal controls. The investigation included the measurements of plasma lipid profiles and plasma total antioxidative status (TAS) such as plasma vitamin E erythrocyte glutathione (GSH) and glutathione peroxidase (GPx), as well as malondialdehyde (MDA) and total plasma total protein thiols (P‐SH). In patients with CAD, erythrocyte GSH and GPx were significantly lower than those found in controls. However plasma TAS and vitamin E were not significantly different between groups. Patients with CAD also had higher MDA and lower P‐SH levels than the controls, which represents the oxidative damage products of lipid and proteins. Multiple regression analysis revealed negative correlations between GSH and cholesterol, GSH and low density lipoprotein (LDL), vitamin E and MDA, as well as P‐SH and MDA. This study demonstrated the status of oxidative stress in patients with stable CAD. Since oxidative stress is the imbalance between the total oxidants and antioxidants in the body, any single oxidant/antioxidant parameter may not reflect the overall oxidative stress system. Thus, in patients with CAD, diets with various types of antioxidants may be more beneficial in increasing antioxidant activity than any particular antioxidant supplementation.