Clear Heart, Clear Mind

Study finds cardiovascular disease looks like risk factor for dementia

THURSDAY, May 9, 2002 (HealthDayNews) -- Another risk factor for age-related dementia may have been uncovered.

New research reveals that people with cardiovascular disease have an increased risk of developing dementia.

"It's exciting to me because I've been saying this for years, and they've done a nice clinical study," says Dr. Michael Freedman, director of the division of geriatrics at New York University Medical Center. "This is sort of how everybody has been treating patients, and it's confirming all that we knew."

The incidence of dementia in the United States is increasing as the population lives longer, yet little is known about its causes. Alzheimer's is the most common form of dementia in older people, followed by vascular dementia, which occurs when blood vessels to the brain become blocked, limiting blood supply and killing tissue.

"This study is exciting because it's getting closer to the idea of who to treat and what to treat," Freedman says.

Scientists already knew treatment of hypertension seems to delay the onset of Alzheimer's. Homocysteine, an amino acid found in the blood, is also a risk factor, and there's been some evidence that lowering cholesterol can delay the start of dementia.

The current study, being presented today at the annual meeting of the American Geriatric Society in Washington, D.C., was part of the larger Cardiovascular Health Study, which examined almost 6,000 people.

The researchers, led by Dr. Anne Newman, a geriatrician and associate professor of medicine and epidemiology at the University of Pittsburgh's School of Medicine, looked at a subset of that group: 3,602 people who had undergone additional cognitive testing.

As it turned out, those with cardiovascular disease had about a 30 percent increased risk of dementia, a result only partially explained by stroke. Those with peripheral artery disease, which affects areas outside the heart and lungs, had the highest risk of dementia.

The study did not look at interventions, but the implications are clear: treating cardiovascular disease may help prevent or delay the onset of different dementias.

"Although the relative risk was moderate, the high prevalence of cardiovascular disease, coupled with the high risk of dementia, in older adults would suggest that prevention of cardiovascular disease may be the most effective preventive measure we have for the prevention of dementia," Newman says in a statement.

"I see this in my office every day. A perfectly healthy 75-year-old with high blood pressure and cholesterol walks into my office. Do you treat it?" Freedman asks. "Just thinking logically, they're 75 and perfectly healthy, we'll just leave you alone. But, on the other hand, all the data is beginning to show that if you take a perfectly healthy 75-year-old and don't do anything, they have an increased risk of Alzheimer's by the time they're 85. If you treat them, you may push off the onset until they're in their 90s, and by then most of us aren't around. This is another bit of evidence that it makes a difference."

What to Do: The National Institute on Neurological Disorders and Stroke has information on Alzheimer's disease and vascular dementia.

SOURCES: Michael Freedman, M.D., professor, geriatric medicine, New York University School of Medicine, and director, division of geriatrics, New York University Medical Center, New York City; May 9, 2002, presentation, American Geriatric Society annual meeting, Washington, D.C.
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