Inflammation Adds to Blood Pressure Risks

High Blood Pressure and C-Reactive Protein May Trigger Heart Attack, Stroke

Medically Reviewed by Brunilda Nazario, MD on November 24, 2003
From the WebMD Archives

Nov. 24, 2003 -- Having high blood pressure may be especially dangerous for women with high levels of the inflammation marker known as C-reactive protein (CRP).

A new study shows that when both blood pressure and CRP levels are elevated, the risk of heart attack and stroke may be as much as eight times higher.

Researchers say that findings lend support to growing evidence that shows inflammation plays an important role in the development of heart disease. C-reactive protein serves as an indicator of inflammation in the body. Inflammation is though to be the underlying mechanism for cardiovascular disease.

"This study provides the first evidence that CRP and blood pressure interact to increase the risk of adverse cardiovascular outcomes," says researcher Paul M. Ridker, MD, MPH, professor of medicine at Harvard Medical School, in a news release. "At all levels of blood pressure, the patients with higher CRP readings were at substantially greater risk of future cardiovascular events than patients with lower CRP."

The findings appear in tomorrow's rapid access edition of Circulation: Journal of the American Heart Association.

CRP and Blood Pressure Work Together

In the study, researchers looked at blood pressure and CRP levels in a group of 15,215 women who were participants in the Women's Health Study and were an average of 54 years old at the start of the study.

After about eight years of follow-up, 321 of the women had a major heart event, such as a heart attack or stroke, or required heart surgery to restore blood flow to the heart.

Researchers found that as blood pressure levels rose, so did the risk of heart problems. But they also found that after adjusting for other risk factors, like smoking and diabetes, C-reactive protein levels rose with blood pressure levels. They also found that in women with similar blood pressure readings, those with higher CRP levels had higher risks of heart disease.

For example, the average CRP level was 1.33 mg/L among women with blood pressure readings less than 120/75 compared with 1.84 mg/L among those with blood pressure levels above 160/95.

Specifically, the study showed that the risk of heart attack, stroke, or other heart-related problems was eight times higher among women with the highest blood pressure and CRP levels compared with those with the lowest.

Researchers say they're not sure whether high blood pressure triggers inflammation, which in turn raises C-reactive protein levels, or if inflammation stimulates high blood pressure.

But they say the fact that they're so closely related may be especially important for stroke prevention efforts. This is because high blood pressure is the most important risk factor for stroke.

"This finding has particular interest for the prevention of stroke because we have known for a long time that high blood pressure predicts stroke risk," says Ridker. "These data raise the intriguing possibility that lowering blood pressure might also lower CRP levels. If so, we hope this will not only prevent heart attacks but [also] the devastating consequences of stroke."

Show Sources

SOURCES: Blake, G. Circulation: Journal of the American Heart Association, Nov. 25, 2003; vol 108. News release, American Heart Association.

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