In the United States, more men and women die of heart disease each year than any other illness, according to the Centers for Disease Control and Prevention. The prevalence of cardiovascular disease makes it important to detect signs of the illness in its early stages. Many people know that lowering their cholesterol levels lowers their risk of cardiovascular disease, but levels of another biomarker called C-reactive protein, CRP, are also important. Discuss your cardiovascular health with your physician to determine if you need tests of cholesterol or C-reactive protein.
Cholesterol
Although people often think of cholesterol as a bad thing, it is essential to your health. Cholesterol is a waxy compound that makes up cell membranes and is used to manufacture hormones, vitamin D and other important molecules. There are two types of cholesterol: high-density lipoprotein, or HDL, and low-density lipoprotein, or LDL. HDL cholesterol is considered "good" cholesterol because it carries cholesterol molecules from the bloodstream to be destroyed by the liver. LDL cholesterol, or "bad" cholesterol, forms deposits on the walls of your arteries. These arterial plaques increase your risk of heart disease.
CRP
C-reactive protein, or CRP, is a type of blood protein that attaches to dying cells. When there is swelling in your body, CRP levels rise dramatically. For this reason, physicians consider CRP a biomarker of inflammation. Atherosclerosis, a condition in which your blood vessels thicken due to fatty deposits, causes inflammation and raises your cardiovascular risk. Testing CRP levels may help doctors determine whether you are at high risk for heart disease.
Blood Tests
Both cholesterol and CRP levels can be assessed using a basic blood test at your doctor's office. A typical lipid panel determines your levels of total cholesterol, HDL cholesterol, LDL cholesterol and triglycerides. An LDL cholesterol level above 100 mg per deciliter or HDL cholesterol level below 60 mg per deciliter puts you at increased risk for heart disease.
A CRP level below 1.0 mg per deciliter puts you at low risk for heart disease, while a measurement between 1.0 and 3.0 mg per deciliter is considered normal. People with CRP levels above 3.0 mg per deciliter have increased risk of heart disease.
Considerations
Not all physicians agree that CRP is an effective indicator of cardiovascular risk. Physician and medical researcher Paul Ridker of Brigham and Women's Hospital in Boston found that using both CRP and cholesterol levels better predicts heart attack risk than cholesterol levels alone. The Mayo Clinic says that CRP is most helpful for people with an intermediate risk of heart disease, as assessed by family history, lifestyle factors such as smoking, and current health. Ask your doctor if a CRP test or lipid panel is appropriate for you.
References
- "Scientific American"; What is CRP?; Peter Libby; Nov. 2008
- MayoClinic.com; C-reactive Protein Test; Dec. 2009
- MayoClinic.com; Cholesterol Test: Results; June 2011
- Centers for Disease Control and Prevention; Heart Disease Facts; Dec. 2010
- "New England Journal of Medicine"; Comparison of C-Reactive Protein and Low-Density Lipoprotein Cholesterol Levels in the Prediction of First Cardiovascular Events; Paul Ridker et al.; Nov. 2002
