June 27, 2005 -- A readily available test that screens for signs of inflammation in the blood may provide valuable new information about heart disease risks among the elderly.
A new study shows that older men and women with elevated levels of the inflammatory marker known as C-reactive protein (CRP) had a higher risk of heart attack or death due to heart disease over the next 10 years. This association was shown regardless of other traditional risk factors, such as high cholesterol or blood pressure levels. Inflammation plays a key role in atherosclerosis -- plaque in blood vessel walls that reduces blood flow.
CRP is an indicator of heart disease risk in middle-aged and healthy people. Higher levels of CRP are associated with higher risks of heart disease. But researchers say this is the first long-term study of the usefulness of measuring CRP levels in the elderly.
"The CRP test can provide useful information beyond standard risk assessment in the elderly," says researcher Mary Cushman, MD, an associate professor of medicine at the University of Vermont in Burlington, in a news release. "Elderly men and women who had elevated blood CRP had a 45 percent increase in their risk of developing coronary heart disease."
The results appear in the June 28 issue of Circulation.
CRP Reveals Elderly Heart Risk
In the study, researchers measured C-reactive protein levels in nearly 4,000 men and women over 65 years old without apparent heart disease. After 10 years of follow-up, 547 of the participants had a heart attack or died of heart disease.
The researchers show that the risk of heart disease is 45% higher in people with elevated CRP levels, even after taking into account risk factors.
The researchers first predicted the risk of heart disease risk over a 10-year period based on risk factors of blood pressure and cholesterol levels, age, smoking status, and sex.
The CRP measure provided additional risk information in older men at risk of future heart disease.
For example, men who were predicted to have a 10%-20% chance of having a heart attack or other heart-related problem in the future actually had a 32% risk of future heart disease if they also had high CRP levels.
For men predicted to have more than a 20% risk of future heart disease, the actual observed risk was 41% among those with high C-reactive protein levels.
Women at high risk (more than 20%) proved to have a 31% risk of heart attack or dying of heart disease if they had high CRP levels. If their CRP levels were normal, the risk dropped to 10%.