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HEALTH
Statin use may stall onset of
Alzheimer's onset
A popular cholesterol-lowering drug
may also stall the onset of Alzheimer's disease, a new study has
found.
The research, published today in
the medical journal Neurology, shows that people who took statins - a
class of drugs that includes Lipitor and Zocor - had fewer signs of
the degenerative brain disorder compared with those not given the
drugs.
Autopsies conducted on 110 brains
donated by subjects aged 65 to 79 showed that statin users had
significantly fewer of the brain changes typically linked with
Alzheimer's disease, including tangles of dead neurons and a buildup
of plaque.
"I won't say that I expected
to get this finding, but it really has caused us to rethink the role
of these drugs in brain aging in general," said Eric B. Larson,
study co-author and executive director of the Group Health Center for
Health Studies in Seattle.
The study is part of a growing body
of research looking at potential benefits of statins in illnesses
other than heart disease, such as osteoporosis and cancer.
Statins are "so commonly used
that people are studying [them] for other uses," said Louise
Pilote, director of internal medicine at McGill University, who has
been studying the effects of statin use for five years, including how
the drugs affect men and women differently.
Statins are believed to work by
lowering low-density lipoprotein - the so-called bad cholesterol -
which in turn prevents progression of dangerous plaque buildup in
arteries, which can lead to a heart attack.
The use of statins has
"skyrocketed" since the mid-1990s, as lowering bad
cholesterol has become one of the top strategies for preventing heart
disease, Dr. Pilote said. In Quebec, British Columbia and Ontario, up
to 80 per cent of patients who have had a heart attack are prescribed
statins, she said.
Scientists have begun to look at
how the drugs affect people in unintended ways, particularly when it
comes to diseases associated with aging. "Blood vessels are
everywhere. So if you have a molecule that interferes with the
stability or the structure of blood vessels, you might expect they
will have several unexpected effects," Dr. Pilote said.
In the case of Alzheimer's, there
is growing evidence of a link between disease and cardiovascular risk
factors such as high blood pressure and high cholesterol, Dr. Larson
said.
He and his research team pulled
study samples from a group of participants involved in a major cohort
study, which began in 1994 as a joint project between the University
of Washington and Group Health.
By July, 2006, 110 of those
participants had died before age 80 and their brains were autopsied.
Of those, 36 per cent had taken statins for an average of five years
before they died. Compared to the non-statin users, their brains
showed significantly fewer of the changes associated with degenerative
cognitive illness.
Dr. Larson said it's not clear why
there is a difference between the groups; however, previous studies on
animals have shown that high levels of cholesterol in the brain may
alter brain function.
The new study contradicts two
previous large, randomized, placebo-controlled trials, which did not
find evidence that statin use protects patients from the onset of
dementia.
Dr. Larson emphasized that the
results are preliminary. A potential shortcoming of the study is that
only people who agreed to have their brains autopsied were included in
the trial.
A second study looking at the
effects of statin use, also published today in the journal Neurology,
showed that people who are hospitalized with strokes are more likely
to die if they stop taking statins within three months of their
stroke.
That study, conducted by
Spanish researchers, showed that people who stopped taking statins
after a stroke were 4.7 times more likely to die or need full-time
care than people who kept taking the drugs. -
by Hayley Mick GLOBE
& MAIL August
28, 2007
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