Hypertension, Inflammation a Deadly Combo
Stroke risk much higher in women with high CRP levels
MONDAY, Nov. 24, 2003 (HealthDayNews) -- High blood pressure and high levels of a certain blood protein linked to vessel inflammation may work in tandem to inflate cardiovascular risk in women, a new study says.
When levels of both blood pressure and C-reactive protein (CRP) were elevated, the risk of future heart attack and stroke increased as much as eight times, researchers report in the Nov. 25 issue of Circulation.
"What our study shows is that, at all levels of blood pressure, knowledge of CRP levels greatly improves our ability to predict which patients are at very high risk," said Dr. Paul Ridker, the director of the Center for Cardiovascular Disease Prevention at Brigham and Women's Hospital in Boston and the senior author of the study.
Researchers have known that people with higher levels of CRP face increased risk of cardiovascular disease. The relationship between blood pressure and vascular inflammation, though, has been less clear.
"What's new is the additive predictability for the two was higher than some would have thought," said Dr. Daniel Jones, a spokesman for the American Heart Association.
While the study alone won't change the way physicians treat patients, the results are important for the research community, says Jones, who is dean of the School of Medicine at the University of Mississippi Medical Center. They provide "another piece of evidence that inflammation may be an important part of the pathway to heart disease and stroke," he adds.
Ridker and his colleagues examined data from 15,215 participants in the ongoing Women's Health Initiative. None of the women included in the sample were receiving hormone replacement therapy.
Nearly a quarter of the women in the sample (24.9 percent) had a history of hypertension when they entered the study, 12.8 percent were receiving treatment for high blood pressure, 12.2 percent were smokers, and 3.3 percent had diabetes. All of these conditions are risk factors for heart disease.
Over an average follow-up of 8.1 years, 321 of the women developed their first cardiovascular event. Thirty-three died from cardiovascular causes, 97 had nonfatal heart attacks, 85 had strokes, and 106 had coronary procedures to restore blood flow to the heart.
For the study, the Brigham and Women's team divided the women into 10 groups based on blood pressure readings and levels of CRP. After adjusting for age and cardiovascular risk factors such as smoking and diabetes, they found that the CRP levels, on average, increased as blood pressure levels increased, they found.
For women with the highest blood pressure and CRP levels, the risk of cardiovascular events like stroke and heart attack was more than eight times greater than those with the lowest readings.
The authors could not determine whether high blood pressure promotes vascular inflammation or whether inflammation is occurring before the onset of hypertension. In either case, it appears that lowering blood pressure might also lower CRP levels to help prevent heart attack and stroke, they say.
"Heart attacks and strokes can be prevented, but we need to tell our patients they are at high risk," Ridker said. "The simple, inexpensive CRP blood test can greatly help for this purpose."