Does morphology of carotid plaque depend on patient's oxidative stress?

ABSTRACT

OBJECTIVES: This study explored the relationship between oxidative stress biomarkers and stability of carotid plaque. We decided to analyze the broad range of parameters describing oxidative stress in patients with carotid stenosis. DESIGN AND METHODS: 124 consecutive patients undergoing carotid endarterectomy were enrolled in the study group. The control group consisted of 49 patients without symptoms of atherosclerosis. The stability of carotid plaques was assessed using GSM (gray-scale median) scoring system and the study group was divided into three subgroups according to echogenicity of the plaque. The following parameters of oxidative stress/DNA damage were analyzed i) urinary excretion of the products of oxidative DNA damage repair; ii) the background level of 8-oxo-7,8-dihydro-2'-deoxyguanosine in leukocytes' DNA and in atherosclerotic plaques; and iii) the concentrations of antioxidant vitamins, uric acid and C-reactive protein in plasma. RESULTS: Oxidative stress (described by redox status) was higher in the patient group than in the control group. There is a correlation between oxidative stress of the patients and stability of the plaque, echolucent plaques (GSM<25) being associated with the highest antioxidant level and lowest excretion of DNA repair markers. CONCLUSIONS: The plaque formation/morphology may depend on local environment and is independent of oxidative stress/inflammation observed on the level of the whole body.