Atrial fibrillation, the most common source of irregular heartbeat, is linked to an increased risk of dementia, researchers from Group Health Research Institute found. In looking only at study participants with atrial fibrillation over a seven-year period, they said individuals had a 40% to 50% higher risk of developing some form of dementia, including Alzheimer’s, compared to those without atrial fibrillation.
Prior to conducting their study, investigators acknowledged that atrial fibrillation could cause strokes and subsequently dementia, and that the risk for both increases with age. But their study showed that atrial fibrillation can increase dementia risk in other ways. Group health followed 3,045 people with a mean age of 74, from 1994 to 2008.
At the beginning of the study, 4.3% of participants had atrial fibrillation, while 12.2% developed it during the research period. Researchers said that 18.8% developed some type of dementia.
“This paper is a wakeup call, telling us that we need to learn more about how to protect brain function, while continuing to give patients with atrial fibrillation the best possible care,” wrote assistant investigator Sascha Dublin, M.D., Ph.D.
In findings published in the Journal of the American Geriatrics Society, researchers wrote that atrial fibrillation might increase dementia risk by weakening the heart’s pumping ability, thus decreasing blood flow to the brain; by increasing the risk of blood clots that cause small, undetectable strokes; or by causing inflammation in the brain.