Abstract
Background: Hypertension is a hallmark risk factor for coronary heart disease, cerebrovascular stroke, congestive heart failure, cardiac arrhythmia, cardiomyopahy and abnormal renal function. Free radicals are involved in the pathogenesis of hypertension by altering endothelial function via oxidative stress.

Aims & Objective: To assess the level of antioxidant enzymes superoxide dismutase (SOD), Catalase, Glutathione peroxidase (GPX) and lipid peroxidation product malondialdehyde (MDA) in hypertensive patients.

Materials and Methods: 100 hypertensive patients and 25 healthy controls were included. Serum levels of enzymes and MDA were estimated by spectrophotometric methods.

Results: The level of antioxidant enzymes were significantly lower and MDA was significantly higher in hypertensive patients as compared to controls (p<0.05). For SOD, significant difference could not be obtained between controls and stage I hypertensives with drugs (p>0.05). We also compared the enzymes and MDA level within the hypertensive groups. Significant results were obtained (p<0.05, 0.01). On comparison between stage I and stage II hypertensive without and with drugs, we found that hypertensive patients on drug have significantly higher level of antioxidant enzymes and lower level of MDA than those without anti-hypertensive drugs (p<0.01).

Conclusion: Our study shows that hypertension is associated with oxidative stress. Adequate control of blood pressure and antihypertensive therapy decrease the oxidative stress, improves antioxidant status and endothelial function.

Key words: Oxidative stress, Malondialdehyde(MDA), glutathione peroxidase(GPX), Superoxide dismutase(SOD), Catalase