Supplementation of atherogenic diet with B vitamins does not prevent atherosclerosis or vascular dysfunction in monkeys.

Abstract

BACKGROUND:

Hyperhomocysteinemia is associated with increased risk of atherosclerotic and thrombotic vascular disease. In many patients, hyperhomocysteinemia can be treated or prevented by dietary supplementation with B vitamins, but the clinical benefit of B vitamins for the prevention of vascular disease has not been proven.

METHODS AND RESULTS:

Using an atherogenic diet that produces both hyperhomocysteinemia and hypercholesterolemia, we tested the hypothesis that dietary supplementation with B vitamins (folic acid, vitamin B(12), and vitamin B(6)) would prevent hyperhomocysteinemia, vascular dysfunction, and atherosclerotic lesions in monkeys. After 17 months, plasma total homocysteine increased from 3.6+/-0.3 to 11.8+/-1.7 micromol/L in monkeys fed an unsupplemented atherogenic diet (P<0.01) but did not increase in monkeys fed an atherogenic diet supplemented with B vitamins (3.8+/-0.3 micromol/L). Serum cholesterol increased from 122+/-7 to 550+/-59 mg/dL in the unsupplemented group (P<0.001) and from 118+/-5 to 492+/-55 mg/dL in the supplemented group (P<0.001). Responses to endothelium-dependent vasodilators, both in resistance vessels in vivo and in the carotid artery ex vivo, were impaired to a similar extent in groups that did and did not receive vitamin supplements. Anticoagulant responses to the infusion of thrombin were also impaired to a similar extent in both groups. Vitamin supplementation failed to prevent intimal thickening in the carotid or iliac arteries.

CONCLUSIONS:

These findings demonstrate that supplementation with B vitamins prevents hyperhomocysteinemia but is not sufficient to prevent the development of vascular dysfunction or atherosclerotic lesions in monkeys with marked hypercholesterolemia, even in the absence of preexisting atherosclerosis.

• Authors: S R Lentz, D J Piegors, M R Malinow, D D Heistad
• Journal: Circulation (Circulation) Vol. 103 Issue 7 Pg. 1006-11 (Feb 20 2001) ISSN: 1524-4539 [Electronic] United States
• PMID: 11181477 (Publication Type: Journal Article)

Chemical References

• Vasodilator Agents
• Folic Acid
• Cholesterol
• Thrombin
• Pyridoxine
• Vitamin B 12

Topics

• Animals
• Arteriosclerosis (blood, physiopathology, prevention & control)
• Blood Coagulation (drug effects)
• Carotid Arteries (drug effects, pathology, physiopathology)
• Cholesterol (blood)
• Diet, Atherogenic
• Dietary Supplements
• Disease Models, Animal
• Folic Acid (administration & dosage)
• Hypercholesterolemia (blood, complications, physiopathology)
• Hyperhomocysteinemia (blood, complications, physiopathology, prevention & control)
• In Vitro Techniques
• Macaca fascicularis
• Partial Thromboplastin Time
• Pyridoxine (administration & dosage)
• Thrombin (pharmacology)
• Treatment Outcome
• Vascular Diseases (blood, etiology, physiopathology, prevention & control)
• Vasodilation (drug effects)
• Vasodilator Agents (pharmacology)
• Vitamin B 12 (administration & dosage)