MONDAY, Feb. 19, 2007 (HealthDay News) -- Cutting their cholesterol numbers may also help women reduce their risk of stroke, new research shows.
Harvard researchers have found that even healthy women with no history of heart disease or stroke are at an increased risk of stroke if they have high cholesterol. The study, in the Feb. 20 issue of Neurology, shows that these women were more than twice as likely to have a stroke than women with normal cholesterol levels.
"The link between cholesterol and coronary heart disease has been shown and replicated many times, but with stroke, it's not been as clear," said Dr. Tobias Kurth, the study's lead author and an assistant professor of medicine at Brigham and Women's Hospital in Boston.
"Some links between stroke and cholesterol have been reported in men and in populations at high risk for or with high cardiovascular events. The findings here for women are clearer, though, and show that even in apparently healthy women, there's a risk," he said
The study looked at more than 27,000 women from the United States and Puerto Rico who were part of the Women's Health Study. The women were all health care professionals, at least 45 years old, and had no history of cardiovascular disease, cancer, or any other major illness. Researchers measured the women's cholesterol levels at the beginning of the study, and follow-up information was collected for an average of 11 years.
During this time, 282 strokes occurred among the women, or, put another way, nine out of every 10,000 women had a stroke each year.
With the exception of HDL (or "good") cholesterol, the study found that all cholesterols were strongly associated with a higher risk of ischemic stroke. Having high total cholesterol was related with a 2.3-fold increase in the risk of stroke and high LDL (or "bad") cholesterol was related with a 1.7-fold increase. The strongest association was found between non-HDL cholesterol and stroke (an almost 2.5 times greater risk of having an ischemic stroke).
"This is confirmation of what most of us in the field expect," said Dr. Matthew Fink, professor of neurology at Weill Cornell Medical College and chief of the division of stroke and critical care at NewYork-Presbyterian Hospital in New York City. "Those of us who care for patients treat them with statins to decrease cholesterol with the assumption that this correlation exists. Now, we have solid research to base our decisions on," he said.
Fink added that while the study is solid and dealt with a good database, its participants are not necessarily representative of the general U.S. population, since they were mostly white and health care professionals, likely meaning they were also more educated.
"Level of education also correlates with health," Fink said. "If a similar study was done looking at a cross section of the population, there may be even higher rates of stroke and other atherosclerotic complications. We don't know."
In addition to this limitation, the study's authors also pointed out that cholesterol levels were measured only once during the study.
Still, both Fink and Kurth said that the findings should be a wake-up call for women and men to start paying attention to their cholesterol levels, even if they're feeling otherwise healthy. Lifestyle changes such as a healthy diet, exercise, preventing obesity, not smoking, and drinking alcohol in moderation can help prevent high cholesterol, they explained, and patients can turn to medications if these interventions don't bring down their numbers.
"Don't wait until you become sick, have a heart attack, stroke, or TIA [transient ischemic attack or "mini stroke"] before you start paying attention to your weight, diet, and exercise. Start early, in your 30s and 40s" said Fink. "If the known risk factors for stroke are addressed in an effective way, you can reduce your risk by 50 to 80 percent. We know what to do to lower the risk -- the difficulty is getting people to pay attention and to change their ways."
For more on women and stroke, visit the American Heart Association.