Summary

Smoking is associated with endothelial dysfunction and abnormalitiesin thrombosis/fibrinolysis system, possibly throughincreased oxidative stress. In this study we investigated theeffect of combined antioxidant treatment with vitamins C andE on endothelial function and plasma levels of plasminogen activatorinhibitor (PAI-1), von Willebrand factor (vWF), tissueplasminogen activator (tPA) and factor VII (fVII), in smokers.Forty-one healthy smokers were randomly divided into 4groups receiving vitamin C 2g/day (group A), vitamin C 2g/dayplus vitamin E 400IU/day (group B), vitamin C 2g/day plus vitaminE 800IU/day (group C) or no antioxidants (controls, groupD), for 4 weeks. Forearm blood flow was measured usingvenous occlusion strain-gauge plethysmography. Forearm vasodilatory response to reactive hyperemia (RH%) or to sublingualnitroglycerin administration (NTG%) were considered asindexes of endothelium dependent or independent dilationrespectively. After treatment, RH% was increased only ingroups B (p <0.05) and C (p <0.001) but not in groups A andD. Plasma levels of PAI-1 and vWF were decreased only ingroup C (p <0.05 for both), while PAI-1/tPA ratio was significantlydecreased in both groups B and C (p <0.05 for both).NTG% and plasma levels of tPA and fVII remained invariable inall groups. In conclusion, combined administration of vitamin Cand vitamin E at high dosages, improved endothelial functionand decreased plasma levels of PAI-1, vWF and PAI-1/tPA ratioin chronic smokers.