Antioxidant Supplementation in Atherosclerosis Prevention (ASAP) study: a randomized trial of the effect of vitamins E and C on 3-year progression of carotid atherosclerosis.
OBJECTIVE
To study the efficacy of vitamin E and C supplementation on the progression of carotid atherosclerosis, hypothesizing an enhanced preventive effect in men and in smokers and synergism between vitamins.


METHODS
Double-masked two-by-two factorial trial, randomization in four strata (by gender and smoking status) to receive twice daily either 91 mg (136 IU) of d-alpha-tocopherol, 250 mg of slow-release vitamin C, a combination of these or placebo for three years. A randomized sample of 520 smoking and nonsmoking men and postmenopausal women aged 45-69 years with serum cholesterol >/= 5.0 mmol L-1 were studied.


METHODS
The population of the city of Kuopio in Eastern Finland.


METHODS
Twice daily either a special formulation of 91 mg of d-alpha-tocopherol, 250 mg of slow-release vitamin C, a combination of these (CellaVie(R)) or placebo for three years.


METHODS
Atherosclerotic progression, defined as the linear regression slope of ultrasonographically assessed common carotid artery mean intima-media thickness (IMT), was calculated over semi-annual assessments.


RESULTS
The average increase of the mean IMT was 0.020 mm year-1 amongst men randomized to placebo and 0.018 mm year-1 in vitamin E, 0.017 mm year-1 in vitamin C and 0.011 mm year-1 in the vitamin combination group (P = 0.008 for E + C vs. placebo). The respective means in women were 0.016, 0.015, 0.017 and 0.016 mm year-1. The proportion of men with progression was reduced by 74% (95% CI 36-89%, P = 0.003) by supplementation with the formulation containing both vitamins, as compared with placebo.


CONCLUSIONS
Our study shows that a combined supplementation with reasonable doses of both vitamin E and slow-release vitamin C can retard the progression of common carotid atherosclerosis in men. This may imply benefits with regard to other atherosclerosis-based events.
Salonen
J T
JT
Research Institute of Public Health, University of Kuopio, Kuopio, Finland and Department of Clinical Pharmacology, Rigshospitalet, University of Copenhagen, Copenhagen, Denmark. jukka.salonen@uku.fi
Nyyssönen
K
K
Salonen
R
R
Lakka
H M
HM
Kaikkonen
J
J
Porkkala-Sarataho
E
E
Voutilainen
S
S
Lakka
T A
TA
Rissanen
T
T
Leskinen
L
L
Tuomainen
T P
TP
Valkonen
V P
VP
Ristonmaa
U
U
Poulsen
H E
HE
D000368:Aged; D000975:Antioxidants / Q000008:administration & dosage* / Q000032:analysis; D001161:Arteriosclerosis / Q000097:blood / Q000517:prevention & control*; D001205:Ascorbic Acid / Q000008:administration & dosage* / Q000097:blood; D002340:Carotid Artery Diseases / Q000097:blood / Q000517:prevention & control*; D018450:Disease Progression; D004311:Double-Blind Method; D004357:Drug Synergism; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D008297:Male; D008875:Middle Aged; D010349:Patient Compliance; D012907:Smoking / Q000009:adverse effects / Q000097:blood; D014810:Vitamin E / Q000008:administration & dosage* / Q000097:blood
D000975:Antioxidants; D014810:Vitamin E; D001205:Ascorbic Acid