Does vitamin C or its combination with vitamin E improve radial artery endothelium-dependent vasodilatation in patients awaiting coronary artery bypass surgery?
BACKGROUND
We evaluated the vasodilatory effects of two antioxidants, vitamins C (ascorbic acid) and E (α-tocopherol), on radial artery and endothelium-dependent responses in patients awaiting coronary artery bypass surgery.


METHODS
The study was performed in three groups. The first group took 2 g of vitamin C orally (n = 31, vitamin C group), the second group took 2 g of vitamin C with 600 mg of vitamin E orally (n = 31, vitamins C + E group), and the third group took no medication (n = 31, control group). After baseline measurements were taken of the radial artery lumen diameter, flow volume and lumen area in the non-dominant radial artery, occlusion was maintained for five minutes with a pressure cuff placed around the arm. The measurements were taken again at the time of deflating the cuff, and 60 seconds later. The measurements were repeated after medication in two of the groups and after placebo in the third group.


RESULTS
We compared values of the vitamin C group with those of the vitamins C + E group, and found that the latter were higher than those of the vitamin C group but not statistically significant. In the control group, there was no statistical difference.


CONCLUSIONS
Vitamin C or its combination with vitamin E significantly enhanced endothelium-dependent vasodilatation in the radial circulation of patients with coronary artery disease. Its combination with vitamin E was superior to vitamin C administration alone for endothelial enhancement but this difference was not statistically significant. We hypothesised that vitamin C or its combination with vitamin E may be used as antioxidants for arterial graft patency in patients undergoing coronary artery surgery.
Department of Cardiovascular Surgery, Ankara Education and Research Hospital, Ankara, Turkey.
Alper
A
Uzun
Umit
U
Yener
Omer Faruk
OF
Cicek
Ozlem
O
Yener
Adnan
A
Yalcinkaya
Adem
A
Diken
Turgut
T
Ozkan
Aysel
A
Turkvatan
Mahmut
M
Ulas
D000284:Administration, Oral; D000328:Adult; D000368:Aged; D000975:Antioxidants / Q000008:administration & dosage / Q000627:therapeutic use*; D001205:Ascorbic Acid / Q000008:administration & dosage / Q000627:therapeutic use*; D001026:Coronary Artery Bypass / Q000379:methods; D003324:Coronary Artery Disease / Q000175:diagnosis / Q000601:surgery*; D004359:Drug Therapy, Combination; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D017534:Radial Artery / Q000000981:diagnostic imaging / Q000187:drug effects* / Q000503:physiopathology / Q000637:transplantation; D013997:Time Factors; D020858:Tissue and Organ Harvesting; D016896:Treatment Outcome; D014421:Turkey; D014463:Ultrasonography; D014654:Vascular Patency / Q000187:drug effects; D014664:Vasodilation / Q000187:drug effects*; D014810:Vitamin E / Q000008:administration & dosage / Q000627:therapeutic use*; D014850:Waiting Lists
D000975:Antioxidants; D014810:Vitamin E; D001205:Ascorbic Acid