CRP: A new heart-risk number to watch?
When we calculate our risks for heart disease, a certain set of numbers comes immediately to mind: our blood pressure, “good” and “bad” cholesterol levels, weight, waist measurement and BMI, or body-mass index. But there is another number doctors may use to identify potential heart disease—our CRP, or C-reactive protein level.
CRP is a protein produced by the liver. Its presence indicates there is inflammation (swelling) throughout the body. Inflammation is the body’s normal response to fever, injury and infection. Since inflammation is also present when arteries of the heart begin to get clogged with cholesterol plaques that restrict blood flow, high levels of CRP may indicate heart disease. CRP has also been linked to heart attack, stroke and risk for the reclosing of an artery that has been treated with angioplasty.
You may have heard reports in the popular media that say CRP is an even more important indicator of heart disease than other risk factors, including cholesterol and blood pressure levels. Some suggest that everyone over 30 should request a CRP blood test as part of their routine physical. Many of the leading medical authorities, however, do not agree about the value of CRP testing.
According to the Mayo Clinic, a CRP blood test isn’t right for everyone. That’s because while a high CRP level may be a risk factor for heart disease, test results are not specific. The test can’t identify where the inflammation is located in your body, so it could be somewhere other than your heart. High levels of CRP can also indicate autoimmune conditions, such as rheumatoid arthritis.
CRP testing alone will not determine your risk for heart disease, but it may be a valuable tool, when combined with other blood tests and heart risk factors in creating a total picture of your heart health. Other important indicators include lifestyle choice (including smoking), family history and current health status.
The American Heart Association does not yet recommend CRP screening for the general public. Rather, it finds that CRP testing is most useful for people known to have an intermediate risk for heart disease—those who have a 10 to 20 percent chance of dying from a heart attack within 10 years. The American Heart Association says CRP testing is not necessary for those at low risk, and that people at high risk should seek treatment regardless of their CRP levels.
Whether a high CRP level actually increases heart risk or just reflects the inflammation caused by other risk factors is still unknown. If your CRP levels are elevated, your doctor will recommend the same lifestyle changes you should make if you have high cholesterol or other heart-risk factors. These include increasing your level of activity, not smoking, losing weight, watching your diet and controlling your blood pressure. Medications used to treat CRP are the same as those used to lower cholesterol levels.
If you are concerned about your CRP level, talk with your primary care physician or cardiologist.