Clear
Heart, Clear Mind
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 is been some evidence that lowering cholesterol can delay
the start of dementia.
The
current study, presented at the recent 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.
Prevention of Heart Disease
Is Key
"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."
Always
consult your physician for more information.
|
June
2002
Persons
With Heart Disease Have Increased Risk of Dementia
Prevention of Heart Disease
Is Key
More On
Homocysteine's Effect on the Heart and Mind
Online Resources
More
On Homocysteine's Effect on the Heart and Mind
Large
elevations in a blood molecule, homocysteine, linked to heart
disease also appear to significantly increase the risk of developing
Alzheimer's disease and dementia.
A
study published earlier this year shows homocysteine is crucial
for many of the body's biochemical processes, and its levels increase
with age. However, the findings, as published in the New
England Journal of Medicine, also show that abnormally
high levels of the molecule, and large increases over time, strongly
predict who will develop dementia.
Taking
folic acid and B vitamins can lower homocysteine, experts say, though
there is no evidence yet to suggest these dietary measures can also
reduce the risk of cognitive problems. However, researchers are
now studying whether taking supplements can slow cognitive loss
in those with mild and moderate Alzheimer's.
"We
don't have that many risk or protective factors for Alzheimer's
disease," says Neil Buckholtz, a dementia expert at the National
Institute on Aging, which funded this study. "Age is still
the major risk factor that we know about, which is clearly not modifiable."
Not
all dementia is related to Alzheimer's; some results from vessel
damage and other illnesses. However, the researchers found that
elevated homocysteine appeared to boost the risk of cognitive problems
associated with both the degenerative brain disorder and other forms
of cognitive loss.
Always
consult your physician for more information.
Online
Resources
American
Heart Association
Journal
of the American Medical Association (JAMA)
National
Council on the Aging
National
Heart, Lung, and Blood Institute (NHLBI)
National
Institutes of Health (NIH)
National
Institute on Aging
New
England Journal of Medicine
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