WebMD Medical News
Laura J. Martin, MD
Jan. 7, 2013 -- Can commonly prescribed blood pressure pills help reduce the risk of developing dementia?
Maybe, according to a new study of 774 elderly Japanese-American men.
While it’s well known that high blood pressure in midlife raises a person’s risk for developing thinking and memory problems as they age, and that certain types of blood pressure medications may help lower this risk, little was known about how a class of drugs called beta-blockers stacked up, until now.
According to the new findings, men who took beta-blockers were less likely to have changes in their brains that can be signs of Alzheimer’s disease and other types of dementia, compared to men who took other types of blood-pressure-lowering drugs.
The findings will be presented at the American Academy of Neurology’s 65th Annual Meeting in San Diego.
All of the men took part in the Honolulu-Asia Aging Study. Of the 774 men, 610 had high blood pressure or were being treated for high blood pressure. Among about 350 who had been treated, 15% received a beta-blocker, 18% received a beta-blocker plus one or more other medications, and the rest received other blood pressure drugs.
All types of blood pressure medications seemed to have a positive effect on the risk of dementia, the study shows.
Researchers led by Lon White, MD, of the Pacific Health Research and Education Institute in Honolulu, Hawaii, performed autopsies on the brains of these men. They looked for brain lesions indicating Alzheimer’s disease and microinfarcts, scars left behind most likely from unrecognized mini-strokes.
Men who had received beta-blockers alone showed fewer brain abnormalities than those who had not been treated for high blood pressure or who had received other blood pressure drugs. Study participants who had taken beta-blockers alone or in combination with another blood pressure medication showed less shrinkage in their brains.
Richard Isaacson, MD, says the new study findings add more grist to the mill when it comes to preventing Alzheimer’s disease. Isaacson is an associate professor of clinical neurology and the director of the Alzheimer's division at the University of Miami Miller School of Medicine.
“Treating blood pressure, in general, is quite likely to reduce the risk of cognitive decline and Alzheimer’s disease, and specific treatments may be preferential,” he says.
Exactly how high blood pressure increases the chances of dementia, and how treating it reduces this risk, is not fully understood, Isaacson says. It may reduce the risk of mini-strokes that can lead to dementia or help brains maintain their volume. “We know that treating high blood pressure reduces your risk for stroke and heart attack, and now the icing on the cake may be that it can also delay the onset of Alzheimer’s disease and other forms of cognitive decline.”
Marc L. Gordon, MD, says more research is needed on what role blood pressure medication including beta-blockers can have on dementia risk. He is chief of neurology at Zucker Hillside Hospital in Glen Oaks, N.Y., and an Alzheimer’s researcher at The Feinstein Institute for Medical Research in Manhasset, N.Y.
“The new study is not an argument for putting beta-blockers in the water supply,” he says.
For starters, the findings may be specific to men of this genetic background. “It underscores evidence in different populations that not only does midlife hypertension increase risk of late-in-life dementia, but a number of different classes of drugs may have an effect on reducing those risks.”
The study should serve as a reminder to know your blood pressure numbers, he says.
“We know that blood pressure is a risk factor for a number of things including heart attack and stroke, but also dementia,” he says. “It is a good idea to get on appropriate treatment if you have high blood pressure, and this may [ease] your risk for all causes of dementia, too.”
These findings will be presented at a medical conference. They should be considered preliminary as they have not yet undergone the "peer review" process, in which outside experts scrutinize the data prior to publication in a medical journal.
SOURCES:American Academy of Neurology’s 65th Annual Meeting, San Diego, Calif., March 16-23, 2013.Richard Isaacson, MD, associate professor, clinical neurology; director, Alzheimer's division, University of Miami Miller School of Medicine, Fla.Marc L. Gordon, M.D, chief of neurology, Zucker Hillside Hospital, Glen Oaks; Alzheimer’s researcher, the Feinstein Institute for Medical Research, Manhasset, N.Y.
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