Effects of vitamins C and E on oxidative stress markers and endothelial function in patients with systemic lupus erythematosus: a double blind, placebo controlled pilot study.
OBJECTIVE
Patients with systemic lupus erythematosus (SLE) experience excess morbidity and mortality due to coronary artery disease (CAD) that cannot be fully explained by the classical CAD risk factors. Among emerging CAD risk factors, oxidative stress is currently being emphasized. We evaluated the effects of longterm antioxidant vitamins on markers of oxidative stress and antioxidant defense and endothelial function in 39 patients with SLE.


METHODS
Patients were randomized to receive either placebo or vitamins (500 mg vitamin C and 800 IU vitamin E daily) for 12 weeks. Markers of oxidative stress included malondialdehyde (MDA) and allantoin. Antioxidants measured included erythrocyte superoxide dismutase and glutathione peroxidase, plasma total antioxidant power (as FRAP value), and ascorbic acid and vitamin E concentrations. Endothelial function was assessed by flow-mediated dilatation (FMD) of the brachial artery and plasma concentration of von Willebrand factor (vWF) and plasminogen activator inhibitor type 1 (PAI-1). Primary outcome of the study included the change in lipid peroxidation as revealed by MDA levels. Secondary outcomes included changes in allantoin and antioxidant levels and change in endothelial function.


RESULTS
After treatment, plasma ascorbic acid and alpha-tocopherol concentrations were significantly (p < 0.05) increased only in the vitamin-treated group, associated with a significant decrease (p < 0.05) in plasma MDA. Other oxidative stress markers and antioxidant levels remained unchanged in both groups. FMD and vWF and PAI-1 levels remained unchanged in both groups.


CONCLUSIONS
Combined administration of vitamins C and E was associated with decreased lipid peroxidation, but did not affect endothelial function in patients with SLE after 3 months of therapy.
Tam
Lai S
LS
Department of Medicine and Therapeutics, Department of Radiology, and the Clinical Immunology Unit, Hong Kong Cancer Institute, Hong Kong. tamls_813@yahoo.com
Li
Edmund K
EK
Leung
Vivian Y F
VY
Griffith
James F
JF
Benzie
Iris F F
IF
Lim
Pak L
PL
Whitney
Bruce
B
Lee
Vivian W Y
VW
Lee
Kenneth K C
KK
Thomas
G Neil
GN
Tomlinson
Brian
B
D000481:Allantoin / Q000097:blood; D000975:Antioxidants / Q000008:administration & dosage*; D001205:Ascorbic Acid / Q000008:administration & dosage* / Q000097:blood; D015415:Biomarkers / Q000097:blood; D019587:Dietary Supplements; D004311:Double-Blind Method; D004359:Drug Therapy, Combination; D004730:Endothelium, Vascular / Q000187:drug effects* / Q000503:physiopathology; D005260:Female; D006304:Health Status; D006801:Humans; D015227:Lipid Peroxidation / Q000187:drug effects; D008180:Lupus Erythematosus, Systemic / Q000097:blood / Q000178:diet therapy* / Q000503:physiopathology; D008315:Malondialdehyde / Q000097:blood; D008875:Middle Aged; D018384:Oxidative Stress / Q000187:drug effects* / Q000502:physiology; D010865:Pilot Projects; D012720:Severity of Illness Index; D014664:Vasodilation / Q000187:drug effects; D014810:Vitamin E / Q000008:administration & dosage* / Q000097:blood
D000975:Antioxidants; D015415:Biomarkers; D014810:Vitamin E; D000481:Allantoin; D008315:Malondialdehyde; D001205:Ascorbic Acid