Researchers from The University of Texas at Dallas and their colleagues have discovered that breathing rates while sleeping can be used to distinguish cognitively normal people from those who have mild cognitive impairment or Alzheimer’s disease.
The researchers, three of whom have affiliations with UT Dallas’ Center for BrainHealth, also found that a dental device to reduce snoring improves cognitive function in individuals who suffer from mild cognitive impairment.
“A good night’s sleep plays an essential role in regulating brain health by removing the waste material and toxins that accumulate,” said Sandra Bond Chapman PhD’06, senior author of the study, the center’s founder and chief director, and the Dee Wyly Distinguished University Chair in BrainHealth. “Although many things can disturb sleep, one of the most common causes is snoring or other breathing issues that cause obstructive sleep apnea.”
The study, published Nov. 1 in a special issue of Geriatrics, examined the relationship between breathing rate during sleep and cognitive function, as well as how a snoring intervention affects brain health.
The team’s pilot study included 18 individuals ages 55 to 85 with a history of snoring. About one-third of the participants were cognitively normal. Another third had mild cognitive impairment, and another third had Alzheimer’s disease. To examine how breathing rate while sleeping changed with the dental device, participants slept at home while portable recorders collected data on their breathing rates, heart rates and snoring.
Clinicians from the Center for BrainHealth assessed the participants’ memory, executive function and attention at baseline and post-intervention. The team found that the maximum breathing rate during uninterrupted periods of sleep can differentiate cognitively normal individuals from those with either Alzheimer’s disease or mild cognitive impairment.
The researchers identified three distinct patterns among the three groups and that allowed them to identify a breathing pattern that might predispose individuals to having dementia. Determining breathing rate during sleep is less expensive and faster than most medical assessments currently used for detecting onset of dementia. As such, easy access sleep assessments at home could provide an informative testing opportunity, said Chapman, who also is professor of psychology in the School of Behavioral and Brain Sciences.
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The researchers utilized the myTAP oral appliance, which snaps into the mouth at night to prevent snoring. For four weeks, participants wore the device at night and snoring decreased. After the intervention period, cognitive function — especially in the domain of memory — improved in the mild cognitive impairment group and no longer differed from cognitively normal individuals.
“These pilot data support growing evidence that points to an important interplay among sleep, cognition and risk of dementia, where poor sleep is associated with disease onset and cognitive impairment,” Chapman said. “Even more intriguing is the possibility that treating sleep disturbances, with a no-risk dental device in the preclinical stages of Alzheimer’s disease or mild cognitive impairment, may offer a promising new treatment avenue to slow or halt this multifaceted disease process.”
Although the team did not notice an overall improvement in the cognitive function of participants with Alzheimer’s disease with this relatively brief intervention period, researchers hope that further research can address whether a longer intervention period or more sensitive cognitive measures would show benefits to individuals who already have the disease.
Alternatives to medicine for treating snoring could help individuals sleep better while also improving their cognitive function. Sleep medications can give individuals the impression that they have slept well when, in reality, the brain never enters the deep phase of sleep that is essential for the housekeeping process that rids the brain of toxins, according to Chapman.
“As many drug trials have indicated, it appears the effectiveness of intervention may be more beneficial when applied very early in the disease progression. These emerging data motivate further work in a larger trial to add to the array of possible treatment protocols for Alzheimer’s where few currently exist or cause significant side effects that outweigh the proven benefits,” she said.
In addition to Chapman, co-authors of the study included Dr. Jeffrey Spence, director of biostatistics at the Center for BrainHealth; researchers from Texas A&M College of Dentistry, including corresponding author Dr. Preetam Schramm; researchers from the University of New England College of Dental Medicine; and former Center for BrainHealth neuroscientist Namrata Das PhD’20, now a National Institute of Drug Abuse fellow at McLean Hospital/Harvard Medical School in Massachusetts.
The study was supported in part by the Wallace Barbara and Kelly King Charitable Foundation Trust, Friends of BrainHealth Distinguished New Scientist Awards (2017 and 2018), the AWARE fund of The Dallas Foundation, the Golden Rule Family Foundation and the Fox Family Foundation.