Is C-Reactive Protein Specific for Vascular Disease in Women?

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The summary below is from the full report titled "Is C-Reactive Protein Specific for Vascular Disease in Women?" It is in the 2 April 2002 issue of Annals of Internal Medicine (volume 136, pages 529-533). The authors are N Rifai, JE Buring, I-M Lee, JE Manson, and PM Ridker. The summaries may be reproduced for not-for-profit educational purposes only. Any other uses must be approved by the American College of Physicians-American Society of Internal Medicine.

What is the problem and what is known about it so far?

Inflammation is the process that helps the body to fight infection or injury. A growing amount of information suggests that inflammation plays a role in the development of blockages in blood vessels and, thus, helps to cause cardiovascular events, such as heart attack or stroke. For example, the blood levels of certain substances caused by inflammation are higher in people who develop cardiovascular disease than in people who do not. C-reactive protein (CRP) is one such inflammatory substance. However, CRP levels in the blood are increased in several types of illness and therefore may just be a marker of various illnesses rather than a reliable sign of cardiovascular disease.

Why did the researchers do this particular study?

To see whether CRP levels are elevated in people who eventually develop cancer, as is the case in people who develop cardiovascular disease.

Who was studied?

643 women who developed cancer or cardiovascular events and 643 women who remained free of these diseases during the 58 months of a large study of women's health.

How was the study done?

The researchers measured CRP levels in blood samples that the women had given at the start of the large study. The researchers then compared the levels of CRP in women who developed cancer, women who developed cardiovascular disease, and women who were free of both illnesses during the 58 months of the study.

What did the researchers find?

Higher CRP levels were associated with development of cardiovascular disease but not with development of cancer.

What were the limitations of the study?

This study examined only women, lasted less than 5 years, and measured CRP levels only once during the study.

What are the implications of the study?

This study suggests that rather than being a marker of disease in general, CRP is a marker of cardiovascular disease. Further research is needed before physicians can determine whether measuring CRP levels is a useful screening test for detecting early forms of heart disease.