 Background: HMG-CoA reductase inhibitors statins are effective lipid-lowering agents and are known to reduce cardiovascular events. Beneficial effects of statins seem to occur very early in the course of their therapy and subgroup analysis of large trials indicates that subjects in statin-treated arms have less cardiovascular events than subjects in placebo-controlled arm with comparable serum cholesterol levels. Therefore, it has been suggested that statins may have antiatherogenic effects beyond their cholesterol lowering effect. Many studies have demonstrated a rapid improvement in vascular function with atorvastatine which cannot solely be accounted for by achieved lipid reduction. A rapid oxidative stress lowering effect of atorvastatin has been proposed as the probable mechanism of this action. Whether atorvastatine has stronger antioxidant effect and whether atorvastatin lowers oxidative stress earlier in the course of therapy than other statins has not been studied yet. 