Feb. 15, 2001 (Fort Lauderdale, Fla.) -- Homocysteine, one of the latest entries to the Top 10 list of heart disease risk factors, also may be a risk factor for stroke, but stroke experts think it is too soon to recommend getting your homocysteine level checked along with your cholesterol and blood pressure.
The problem with homocysteine is that no one is willing to say what is a normal level and what is considered high. Part of the reason for that reluctance, say stroke experts meeting here at the American Heart Association's 26th International Stroke Conference, is "that we are dealing with somewhat of a moving target," says Ralph Sacco, MD, associate chair of neurology at Columbia University, who chaired a press conference on homocysteine and stroke.
What are known, Sacco says, are that homocysteine levels increase with age and that the risk of stroke appears to increase as levels go up.
Will reducing homocysteine levels reduce the risk of a second stroke in patients who already have had a stroke? George Newman, MD, professor of medicine at the State University of New York at Stony Brook, is one of the investigators of a study that will attempt to answer this question.
Researchers with the stroke prevention study think that women who have homocysteine levels of 8.5 mmol/L or less, or men with 9.5 or less, "have virtually no risk for stroke," Newman tells WebMD. After that, he says, the "risk begins to climb incrementally.
"In my clinical practice, I would start treating at a level of 12," Newman says.
Souvik Sen, MD, assistant professor of neurology at NJ Neuroscience Institute in Edison, N.J., says that he considers an elevated homocysteine to be 14. "I begin treating at that level," he says.
Stroke experts are eager to treat elevated homocysteine because "it can be treated very easily with vitamins," Sacco says. An easy, inexpensive treatment is always attractive, he says. The vitamins used to treat homocysteine elevations are the B vitamins, specifically folate, niacin, and B-12.
"So you can get folate from cereals, which are now fortified with folate, niacin from fresh fruits, and B-12 from red meats," Newman says.
Asked why homocysteine levels may be elevated, Sen explains that "nutritional deficiencies may be a cause, and some medications, for example Dilantin, can elevate homocysteine." He says that kidney disease also can raise homocysteine, adding that alcohol use and low physical activity also are associated with homocysteine elevations.
Yet, not all stroke experts are eager about labeling homocysteine as a risk factor.
"Right now, we don't have good data for homocysteine and stroke," Larry B. Goldstein, MD, a member of the AHA's Stroke Council, tells WebMD. He says he isn't convinced that the levels mentioned by other researchers really reflect "normal" or "elevated" homocysteine. "Those levels are just arbitrarily plucked from prior data" but haven't really been tested, he says.
The bottom line, Goldstein says, is that it is too early to recommend checking homocysteine levels as a routine part of a physical.
Even homocysteine believers suggest that universal screening is probably not yet necessary. Sacco says that more studies are needed before homocysteine screening joins cholesterol and glucose as routine blood tests.