(October 29, 2008 - Insidermedicine) High levels of C-reactive protein (CRP) in the blood do not appear to directly cause blood vessel disease, even though it has been linked with an increased risk for this condition, according to an analysis in the New England Journal of Medicine.

Here is some information about CRP:

•    It is a protein that is increased in the body when inflammation occurs.

•    Because inflammation plays an important role in the development of blood vessel disease, measuring levels of CRP in the blood may help predict one’s risk for cardiovascular disease or stroke.

•    What remains unclear is whether CRP itself contributes to inflammation or whether it is simply an indicator.

Danish researchers studied the relationship between CRP levels and the risk of disease in the blood vessels that feed the heart and brain among over 40,000 individuals. They also looked at whether carrying genes associated with high CRP levels was linked with increased risk.

Those with high amounts of CRP in the blood had a 60% increased risk of having disease in the blood vessels that feed the heart and a 30% increased risk of having disease in the blood vessels that feed the brain, compared to those with low CRP levels. Those carrying genes associated with high CRP levels did have CRP levels that were up to 64% higher than those who were not carriers of these genes, but they did not have an increased risk of blood vessel disease.

We had a chance to speak with Dr. Børge Nordestgaard from the University of Copenhagen, who offered some further insight.

Today’s research suggests that while high CRP levels are linked with an increased risk of blood vessel disease, the relationship is probably not causative because carrying genes that increase the risk for higher CRP levels does not increase the risk of blood vessel disease.

For Insidermedicine in Depth, I'm Dr. Susan Sharma.