Calcium deposits don't predict stroke risk

Canadian doctors are questioning the notion that calcium deposits in the carotid arteries of the neck -- measured using an X-ray technique called computed tomography(CT)scanning -- indicate an increased risk of stroke.

A number of studies have suggested a link between calcium buildup in the heart's arteries and an increased risk of heart attacks, leading to the belief that a similar association might hold between calcification of the carotid arteries and the risk of stroke. Companies in the United States are even offering screening for calcification of the carotid arteries.

But a study by led by Dr. Allan Fox of the University of Toronto shows these services are jumping the gun. They looked at neck and brain CT scans of 221 people and assessed the degree of carotid calcification and changes in the brain's white matter, which have been associated with an increased stroke risk.

Older people had more calcium buildup and white matter change, but there was no association between the degree of carotid calcification and the amount of white matter change.

"Can we use calcification in the carotid arteries as something to do with stroke disease? The particular thing we looked at showed no evidence for an association," Fox says. "This is one of those things that gets going because it sounds logical in a lay sense and people sell services. I would hope people would look at results like this and continue to be skeptical."

Another recent study by researchers at Johns Hopkins Hospital in Baltimore also suggests calcification of the carotid arteries has no relationship to stroke. They looked at CT scans of 74 patients who had a stroke and 94 healthy people of the same ages. Carotid artery calcification did not differ between the two groups.

this article took from http://www.macleans.ca