Association between oxidative stress and blood pressure in Korean subclinical hypertensive patients

ABSTRACT

This study was conducted in order to investigate the association between hypertension and oxidative stress-related parameters and to evaluate these parameters in subclinical hypertensive patients and normotensive subjects living in Korea. We attempted to determine whether oxidative stress-related parameters would differ between two groups of 227 newly-diagnosed, untreated (systolic blood pressure (BP) > or = 130 mmHg and diastolic BP > or = 85 mmHg) and 130 normotensive subjects (systolic BP < 120 mmHg and diastolic BP < 80 mmHg). General characteristics of the subjects were collected using a simple questionnaire. From subjects' blood, degree of DNA damage in lymphocytes, the activities of erythrocyte superoxide dismutase, catalase, and glutathione peroxidase, level of plasma total radical-trapping antioxidant potential (TRAP), glutathione, and anti-oxidative vitamins, as well as plasma lipid profiles and conjugated diene (CD) were analyzed. Evaluation of the associations of oxidative stress-related parameters with blood pressure of the subjects was performed using Pearson partial correlation and multivariate logistic regression analysis after adjusting for confounding factors. Several oxidative stress-related parameters were higher in subclinical hypertensive patients than in normotensive subjects. Plasma levels of alpha-tocopherol, beta-carotene, TRAP, and activity of GSH-px were significantly lower in subclinical hypertensive patients than in normotensive subjects. Increased levels of DNA damage, lipid peroxidation, triglyceride, total cholesterol, and LDL-cholesterol were observed in subclinical hypertensive patients. These results confirm an association between blood pressure and oxidative stress-related parameters and suggest that the pathogenic role of oxidative stress in hypertension might be significant.