Blood Protein May Predict Heart Attack But Not Stroke
More study needed into how CRP levels influence risk
WEDNESDAY, Oct. 21, 2009 (HealthDay News) -- High blood levels of C-reactive protein (CRP) may increase a person's risk for heart attack and death, but not for stroke, a new study has found.
The study included 2,240 people in New York City who were 40 or older and stroke-free. At the start of the study, the participants' blood was checked for levels of CRP (a marker for inflammation) and their heart attack and stroke risk factors were evaluated by researchers.
During an average follow-up of eight years, there were 198 strokes, 156 heart-related events and 586 deaths. People with CRP levels greater than 3 milligrams per liter of blood were 70 percent more likely to have a heart attack and 55 percent more likely to die than those with CRP levels of 1 milligram per liter or less, the researchers reported in the Oct. 20 print issue of Neurology.
After they took other risk factors into account, the study authors concluded that CRP levels didn't influence stroke risk.
"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," study author Dr. Mitchell Elkind, of Columbia University Medical Center in New York City, said in a news release from the American Academy of Neurology. "However, 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."
CRP levels are influenced by factors such as physical activity, smoking, alcohol consumption and diabetes.
"It 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," Elkind said.
"It may be that the failure of CRP to predict stroke in our study, unlike in some other populations, reflects the fact that our population is older and has more of these risk factors. While CRP may be predictive in generally young healthy people, it may be less useful among older, sicker people. More research needs to be done on why the protein wasn't able to predict stroke in the same manner as heart disease," he said.
The American Association for Clinical Chemistry has more about C-reactive protein.