General responses to selected questions from Joel Braunstein, MD, of Johns Hopkins University and Joseph Toscano, MD.
Question:
What does having a result of 21.1 on a C-reactive protein test mean?
Answer:
Thank you for asking such an important question, which, I am sure, occupies the minds of many other individuals also reading this column. C-reactive protein is a molecule found inside the bloodstream. It is manufactured by the liver in response to tissue injury or inflammation, which may occur as a result of infection or other condition that stimulates the immune system. Based upon what I've told you thus far, you may be wondering what C-reactive protein has to do with the cardiovascular system.
Over the last decade, our understanding of the process of atherosclerosis (hardening of the arteries) has fundamentally evolved – formerly, we presumed atherosclerosis was primarily due to abnormal cholesterol deposition in the walls lining blood vessels. Over time, this progressive deposition would lead to progressive narrowing of the arteries and ultimately lead to the well-recognized clinical manifestations of cardiovascular disease such as heart attack and stroke. New insight into atherosclerosis now tells us that we grossly underestimated the complexity of this process. Part of this new knowledge recognizes that inflammation is among the most essential mediators of atherosclerosis. Inflammation plays a vital role in nearly every stage of development of atherosclerosis, from the earliest beginnings of silent heart disease to the most acute moments of a heart attack.
Because C-reactive circulates in the bloodstream and its levels are an indicator of the amount of inflammation that occurs in the body at any given time, medical researchers have increasingly studied it as a potential marker of the severity and acuity of atherosclerotic heart disease. The results of these studies have been dramatic. C-reactive protein is a very strong predictor for the development of future cardiovascular events like heart attack, stroke, and peripheral vascular disease. C-reactive protein also closely correlates with other cardiovascular risk factors like smoking, obesity, and type 2 diabetes mellitus. What remains unknown is whether C-reactive protein is, in and of itself, involved with the inflammation of atherosclerosis or merely just a marker of the process. In addition, there is some controversy about how much additional cardiovascular risk information elevated C-reactive protein levels offer over more conventional risk factors like high blood pressure or cholesterol, diabetes, obesity, smoking, smoking, and family history of heart disease.
