Alzheimer's disease may progress more rapidly in
people with high blood pressure or a form of
irregular heartbeat, atrial fibrillation, according to
results of a Johns Hopkins study published in the
Nov. 6 issue of Neurology. The findings suggest that
treating these conditions may also slow memory
loss in people with Alzheimer's.
While current medications for Alzheimer's are
effective for some patients in slowing the rate
of the disease's progression, many patients do not benefit
from the treatments or cannot tolerate
them, says lead researcher Michelle M. Mielke, of the Department of Psychiatry and Behavioral
Sciences at the Johns Hopkins School of Medicine.
"The possibility that specific vascular conditions may
affect how fast a person with AD declines
provides new opportunities for slowing the rate of AD
progression," Mielke said. "Treatments for
atrial fibrillation and high blood pressure are relatively
inexpensive and safe and may reduce memory
decline in AD patients with these conditions."
The study examined 135 men and women over 65 who were
newly diagnosed with Alzheimer's
disease. All had undergone annual memory tests for an
average of three years.
Results showed that 10 people with high blood pressure
(systolic pressure over 160) at the time
of diagnosis showed a rate of memory loss roughly 100
percent faster than those with normal blood
pressure. In addition, 10 with atrial fibrillation at the
time of the diagnosis showed a rate of memory
decline that was 75 percent faster than those with normal
heartbeats.
The study participants were part of the Cache County
Study on Memory Health and Aging,
which has been following a group of 5,092 people 65 or
older living in Cache County, Utah, since 1995.
"What makes this group and study unique is that we
have been following these participants in
the community for over a decade, even before they were
first diagnosed with AD, so we know a good
deal about their medical history," Mielke said. "Studies
that enroll AD patients only from clinics may
miss key factors, such as date of onset and history of
cardiovascular disease and treatment."
Mielke says she is currently working on similar
studies using larger sample sizes to better
understand the potential role that vascular factors play
before diagnosis of Alzheimer's and their role
over the course of the disease's progression.
Mielke also recently contributed to a study by Johns
Hopkins psychiatrist Paul Rosenberg that
examined drugs that modify high blood pressure and high
cholesterol, such as beta-blockers,
diuretics, calcium-channel blockers and statins, and their
effects on cognitive and functional decline.
Constantine Lyketsos, Rosenberg and Peter Rabins, all
of the Department of Psychiatry and
Behavioral Sciences at the Johns Hopkins School of Medicine
also contributed to this study.
Additional researchers are JoAnn Tschanz, Maria Norton, Ron
Munger, Larry Cook and Chris Corcoran,
all of Utah State University; Kathleen Hayden and Kathleen
Welsh-Bohmer, Duke University; Robert
Green, Boston University; and John Brietner, University of
Washington.
This study was supported by grants from the National
Institute on Aging.
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