Jan. 12, 2010 -- Drugs commonly used to treat high blood pressure and heart
disease may reduce the risk of dementia and Alzheimer's disease, a new study
Boston University scientists, reporting in the journal BMJ, say
a class of high blood pressure drugs called angiotensin receptor blockers
is associated with a striking decrease in the risk of occurrence and
progression of dementia.
The researchers, using information from a U.S. Department of Health System
Veterans Affairs database of more than 5 million people, examined records of
more than 800,000 predominantly male patients 65 or older.
The researchers compared the patients in groups that included those using an
angiotensin receptor blocker (ARB); those using an ACE inhibitor called
lisinopril (Prinivil, Zestril); and those using other blood pressure/heart
disease medications (excluding statins).
Angiotensin receptor blockers include candesartan (Atacand), irbesartan
(Avapro), losartan (Cozaar), and valsartan (Diovan).
There were no differences in average blood pressure among the three groups.
The patients taking an angiotensin receptor blocker had a 19% lower risk of
developing dementia compared to those taking lisinopril and a 24% lower risk
compared to use of other blood pressure/heart medications. People taking
both an ACE inhibitor and an angiotensin receptor blocker, which both target
the angiotensin system, had a 46% lower risk of dementia compared with those
taking other medications.
The researchers also studied records of patients who already were suffering
from dementia or Alzheimer's. Those patients taking ARBs, the scientists
report, had a lower risk of being admitted to a nursing home or dying. Those
taking both an ARB and an ACE inhibitor had a 67% lower chance of being
admitted to a nursing home.
The results suggest that ARBs might protect against developing Alzheimer's
disease and dementia, the researchers write.
"For those who already have dementia, use of ARBs might delay deterioration
of brain function and help keep patients out of nursing homes," says Benjamin
Wolozin, MD, PhD, professor of pharmacology at Boston University and one of the
study researchers. "The study is particularly interesting because we compared
the effects of ARBs to other medications used for treating blood pressure or
The researchers write that they do not know exactly why ARBs might be so
beneficial, but they believe the drugs may help prevent and reduce nerve cell
injury from stroke or blood vessel damage.
The researchers say they've conducted the first large-scale study to
investigate whether angiotensin receptor blockers reduce the risk of developing
Alzheimer's or dementia.
The findings of the study are "immense," write Colleen J. Maxwell, PhD, and
David B. Hogan, MD, of the University of Calgary in an accompanying editorial.
"About 36 million people worldwide have a form of dementia such as Alzheimer's
disease," they write. "If survival, prevention or treatment do not improve
dramatically, this number could double over the next 20 years."
However, they add, though the findings of the study are dramatic, further
work is needed to verify the results.