FRIDAY, Feb. 6, 2004 (HealthDayNews) -- It seems women over 55 need to worry more about having a stroke than their male counterparts do.
They have a one-in-five chance of suffering a stroke during their lifetime, while the odds are one-in-six for men in the same age group, a new analysis shows.
It's the first time researchers have quantified the lifetime risk of stroke among men and women in the United States.
"It gives you an idea of the magnitude of the problem," says study author Dr. Sudha Seshadri, an assistant professor of neurology at the Boston University School of Medicine. "We did not know that before for stroke, surprising as that may seem."
That statistical snapshot is based on data from the Framingham Heart Study, a long-running, landmark look at the factors that contribute to heart disease.
The authors of the new analysis presented their findings Feb. 6 at the American Stroke Association's annual meeting in San Diego.
The results also highlight the critical role that high blood pressure plays in boosting stroke risk. At every age, people's risk of stroke increased with higher baseline blood pressure, suggesting that elevated blood pressure is a powerful predictor of stroke risk, the researchers found.
Stroke is the third-leading cause of death in the United States and a leading cause of long-term disability in adults, according to the National Institute of Neurological Disorders and Stroke.
A stroke occurs when the blood supply to the brain is interrupted. About 80 percent of all strokes are "ischemic," caused by blood clots that block a blood vessel or artery in the brain. The other major type, hemorrhagic stroke, occurs when a blood vessel in the brain bursts, bleeding into the spaces surrounding the brain cells.
Signs of stroke include sudden numbness or weakness, especially on one side of the body, or sudden confusion or trouble speaking or understanding speech. Stroke victims may suddenly have trouble seeing or walking. They may experience dizziness or loss of balance or coordination.
The Boston University researchers studied 4,883 participants from the original Framingham study who lived stroke-free to age 55. The participants were followed every two years for up to 40 years or until they had a stroke, developed Alzheimer's disease or died.
A total of 859 participants suffered a stroke. Of these, 86 percent had an ischemic stroke.
For people 75 years old or younger, short-term risk of stroke was higher in men. But for women the lifetime risk of stroke was always higher, the researchers found.
The authors used National Heart, Lung, and Blood Institute guidelines defining "normal" blood pressure as less than 120 over less than 80.
People who had "stage 1" hypertension, meaning a blood pressure of 140 or greater over 90 or greater, were twice as likely to have a stroke as people with normal blood pressure.
For people who don't take high blood pressure seriously, particularly younger adults, the news may boost blood pressure awareness, says Dr. Alison Schecter, an assistant professor of medicine specializing in women's cardiac prevention at Mount Sinai School of Medicine in New York City.
"It gives a huge impetus to control blood pressure when you're younger because it affects things when you're older," she says.
Seshadri believes the nation may need to attack the problem of stroke the same way it has smoking.
"I think physicians and public health officials should probably be looking at blood pressure as a big population risk factor for stroke," she says. That may require exploring ways to cut salt in people's diets, for example, or increasing exercise.
To learn more about stroke, visit the National Institute of Neurological Disorders and Stroke. For more on high blood pressure, check with the American Heart Association.