B Vitamins for the Prevention of Vascular Disease
Insufficient Evidence to Justify Treatment
- Colin Baigent, BM BCh, FRCP;
- Robert Clarke, MD, FRCP
- Author Affiliations: Clinical Trial Service Unit and Epidemiological Studies Unit, University of Oxford, Oxford, England.
- Corresponding Author: Colin Baigent, BM BCh, FRCP, Richard Doll Building, Old Campus Road, Roosevelt Drive, Oxford OX3 7LF, England (colin.baigent{at}ctsu.ox.ac.uk).
Since this article does not have an abstract, we have provided the first 150 words of the full text.
Individuals with homocystinuria, a rare genetic disorder associated with markedly elevated plasma homocysteine levels (ie, 100-300 μmol/L [to convert to mg/dL, divide by 7.397]—at least 10 times higher than the general population), experience rapidly progressive atherosclerosis and associated thromboembolic events in early adulthood. This observation prompted the “homocysteine hypothesis” that moderately elevated homocysteine levels might be of causal relevance to cardiovascular disease in the general population.1
Many observational epidemiological studies have reported that cases with coronary heart disease (CHD) or stroke have higher homocysteine levels compared with age and sex-matched controls. In 1995, a meta-analysis of observational studies, involving a total of 2297 CHD cases, indicated that a 5 μmol/L higher homocysteine level was associated with about a 70% increase in the risk of CHD.2 These studies were mainly retrospective in design, however, and were unable to exclude the possibility that the atherosclerotic disease process might itself have …
