Protein in Blood Could Predict Heart Attack and Death, Not Stroke

According to a new study from the Columbia University Medical Center in New York City, a protein in the blood known as C−reactive protein (CRP) may help predict one’s risk of heart attack and death. The same protein did not reliably predict stroke, however, which was an unexpected finding in light of earlier research.

The researchers found that participants whose CRP levels were over 3 milligrams/liter of blood were 70% more likely to suffer a heart attack and 55% more likely to die than participants whose levels were 1 mg/liter or lower.

C−reactive protein is known to increase in response to infection and low−grade inflammation in the body, which makes it a potential candidate for predicting cardiovascular disease. “The role of this protein in predicting risk of stroke has been controversial, although prior studies have found it to be a marker for predicting risk of heart disease," said lead author Mitchell Elkind in a news release from the American Academy of Neurology. Elkind and his colleagues followed 2,240 participants over the age of 40 for an average of eight years. Their CRP levels were measured at the study’s onset and at its end. The instances of heart attack, stroke, and death among the participants were analyzed to determine a potential link to CRP levels.

The researchers found that participants whose CRP levels were over 3 milligrams/liter of blood were 70% more likely to suffer a heart attack and 55% more likely to die than participants whose levels were 1 mg/liter or lower. No relationship between CRP level and stroke risk was observed.

Elkind says that “in our large, multiethnic population, CRP levels did not play a role in predicting stroke, though they may still help determine whether someone is at risk of heart attack or early death."

The good news is that, in addition to inflammation and infection, CRP levels appear to rise and fall in response to various lifestyle factors, many of which are within our control, like smoking, blood pressure, and hyperglycemia. Elkind adds that "[i]t appears that by living a healthy lifestyle, one may be able to lower these protein levels, thus lowering the risk of cardiac events and possibly early death.”

The study was published in the October 20, 2009 issue of Neurology.