February 4, 2004 CHICAGO (AP) -- A simple and seemingly commonsense strategy for lowering the risk of recurring strokes failed to work in a study of nearly 3,700 patients.
The strategy involves giving B vitamins to stroke patients to reduce levels of a substance called homocysteine in their blood. Many studies have suggested that high levels of homocysteine raise the risk of heart attacks and strokes.
But the researchers found no difference in outcome between those who got high doses of vitamins and those who got low doses.
The high vitamin doses did a better job of lowering homocysteine levels, but about 8 percent of the patients in both groups had another stroke during the two years that they were studied.
The study appears in Wednesday's Journal of the American Medical Association. It was led by Wake Forest University neurologist Dr. James Toole.
Toole called the results surprising and speculated that the researchers "got in there too late." Lowering homocysteine still might help reduce stroke risk in younger, healthier patients, he said.
Homocysteine is produced when the body metabolizes protein-rich foods. High levels in the blood can be genetic or caused by diet and are believed to damage blood vessel walls.
The patients studied were age 66 on average, with homocysteine levels at the upper limit of normal or higher. The average level declined by about one-quarter in the group that got high doses of vitamins.
Dr. Daniel Hanley, a stroke and brain injury specialist at Johns Hopkins Medical Institutions, agreed that the link between homocysteine levels and strokes still might be plausible and said the study might have been too small to find a connection.
American Stroke Association spokesman Dr. Mark Alberts said the study might have been too short to see lasting effects from reducing homocysteine levels.
Alberts, director of Northwestern University's stroke program in Chicago, said he will continue to use vitamins to treat high homocysteine levels since the risks from vitamins are so small and there may still be some benefit.
Copyright 2004 The Associated Press. All rights reserved.
