January 8, 2013
(USA TODAY) -- If you have high blood pressure and haven't treated it yet, consider this: getting it under control may also reduce your risk of dementia, suggests a study out Monday.
Men treated with anti-hypertensive drugs were found in autopsies to have fewer microinfarcts (a sign of small strokes), fewer amyloid plaques and tangles (signs of Alzheimer's disease) and less brain atrophy.
Those on beta blockers, one of the least recommended medicines because of their side effects, had the healthiest brains, compared with other treatments. They had "about half as severe damage," said physician Lon White, the lead author. But anyone who was treated "fared better than those who had no treatment."
"What we're seeing is another advantage of treating hypertension," said White, of the Pacific Health Research and Education Institute in Honolulu. "It reduces heart disease and stroke, but it looks like it can also reduce all kinds of dementia."
About a third of U.S. adults, an estimated 68 million, have high blood pressure; about half of them don't have it under control, the Centers for Disease Control and Prevention said. Called the silent killer, hypertension has no symptoms, and many people don't know they have it.
Findings, to be presented in March at the American Academy of Neurology's annual meeting, were published Monday on the group's website.
The study looked at 774 Japanese-American men in the Honolulu-Asia Aging Study, one of the largest brain autopsy studies ever done, White said. The only way to confirm most dementias is by autopsy.
The brain relies on healthy arteries to deliver a steady supply of blood. Hypertension damages arteries by turning an open and flexible channel into a thick and stiff one, known as arteriosclerosis. Two kinds of dementia, vascular dementia and mild cognitive impairment, occur from a narrowing and blockage of arteries brought on by high blood pressure. Also, brain damaging strokes can occur after blood clots form in arteries and interrupt blood flow.
Beta blockers are not the first line of treatment for high blood pressure, according to guidelines issued by the Joint National Committee on Prevention, Detection, Evaluation and Treatment of High Blood Pressure.
They can increase risk of stroke in the elderly, and they can cause confusion and erectile dysfunction, said Sripal Bangalore, a cardiologist at NYU Langone Medical Center in New York, who was not involved with the new study. "This raises more questions than it answers, but nevertheless it calls for randomized trials to test these associations between beta blockers and their protection against dementia."
"Maybe we need to think more about using beta blockers to help control dementia," said JoAnne Foody, director of cardiovascular wellness at Brigham and Women's Hospital in Boston.
Beta blockers slow the heartbeat, reduce the force of the heart muscle's contractions and decrease blood vessel contraction in the heart, brain and the rest of the body. Other drugs -- such as diuretics, ACE inhibitors and calcium channel blockers -- treat hypertension in other ways.
Most patients require a "cocktail of multiple drugs" to treat hypertension, Foody said.
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