Evaluation of oxidative stress in coronary heart disease at baseline and during exercise test

Oxidative stress has probably a role in coronary heart disease (CHD), but studies focused on the behaviour of oxidative status in patients with stable CHD have obtained controversial results. On the other hand, an increased release of leukocyte elastase is considered a marker of CHD. Exercise can induce oxidative stress and leukocyte activation, so the aim of this study was to evaluate oxidative status and plasma elastase level in a group of subjects with stable coronary heart disease (CHD), at baseline and during an exercise test. We enrolled 15 patients with previous acute myocardial infarction, all treated with statins and platelet antiaggregating agents. As parameters of oxidative status we determined the thiobarbituric acid reactive substances and total antioxidant status (TAS). The exercise test was performed according to the Bruce protocol. At baseline, elastase level was higher in CHD subjects than in normal controls and during the exercise test it increased in both groups in comparison with basal values. Regarding oxidative status, only TAS was slightly lower in CHD subjects than in normal controls. In both groups, during exercise test, no parameter of oxidative status was significantly different compared to basal values. In conclusion, CHD patients showed, at rest, an abnormal neutrophil activation and a lower antioxidant status. The exercise test further activated neutrophils but did not influence oxidative status. The absence of a marked oxidative stress in our patients may be partly due to the pharmacological treatment, which apparently did not influence the abnormal leukocyte activation.