Elevated plasma homocysteine as risk factor for peripheral arterial disease--what is the evidence?

There is abundant evidence that elevated plasma homocysteine (HC) is independently associated with presence of atherosclerotic disease. There is credible evidence from a number of prospective studies that elevated HC is independently associated with progression of atherosclerotic disease. All studies to date agree that vitamin therapy, primarily folate, results in reliable decreases in HC, without recognized toxicity or side effects. Two small, randomized clinical trials have demonstrated clinically relevant benefit from folate treatment, which reduced HC in patients, compared to placebo. The results of multiple large scale clinical trials will be available within 2 to 5 years, and these have sufficient power to determine whether vitamin therapy intended to lower plasma HC will be established as the first effective therapy for atherosclerosis that does not involve expensive medication with toxic side effects and/or difficult changes in habits or lifestyle.