Effect of atenolol and enalapril treatment on oxidative stress parameters in patients with essential hypertension

Background: Oxidative stress has emerged as an important factor in the pathophysiology of hypertension. It also contributes to various complications associated with hypertension like vascular injury, atherosclerosis, renal dysfunction, and hypertensive end-organ damage. Present study was done to evaluate the effect of atenolol and enalapril, two commonly prescribed antihypertensive drugs, on oxidative stress in patients with hypertension. Method: Sixty newly diagnosed hypertensive patients were randomly assigned to either atenolol (n = 30) or enalapril therapy (n = 30) and followed up for the period of three months. Twenty normotensive healthy volunteers served as control. Plasma malondialdehyde, superoxide dismutase and catalase levels were measured at the time of enrollment and at the end of three months of antihypertensive treatment. Results: Plasma malondialdehyde was significantly increased whereas superoxide dismutase and catalase were significantly reduced in newly diagnosed hypertensive patients compared to controls. After three months of enalapril therapy, plasma malondialdehyde was significantly reduced and superoxide dismutase and catalase were significantly elevated. Atenolol therapy had no effect on these oxidative stress parameters. Conclusions: Enalapril therapy significantly reduced oxidative stress in contrast to atenolol. Thus enalapril therapy may prove beneficial compared to atenolol by preventing oxidative stress and related complications in hypertension in view of life long therapy required for the treatment of hypertension.