Falling asleep during the day may not be just a sign of sleep deprivation, but it may also be an early indicator of the onset of Alzheimer's disease.
Alzheimer's disease, a degenerative brain disorder that results in memory loss, is a complicated disease that could not be attributed to a single cause. However, research over the recent years has slowly started to identify factors that increase the risk of Alzheimer's disease.
Sleep Deprivation Linked To Alzheimer's Disease
A new study, described by researchers as the first of its kind and published in the Jama Neurology journal revealed that sleepiness in the day among elderly people with normal cognition may result in the buildup of amyloid in the brain. The accumulation of amyloid in the brain is one of the first pre-clinical stages of Alzheimer's disease, happening long before the onset of symptoms of dementia.
According to Prashanthi Vemuri, an author of the study and a Mayo Clinic research faculty member, the relationship between sleep disruptions and amyloid has been "a chicken and egg problem." It was known that proper sleep removed amyloid from the brain, but also that the presence of amyloid resulted in disturbances in sleep.
"In our study, we wanted to know if excessive daytime sleepiness causes an increase of amyloid over time in people without dementia," said Vemuri. "And the answer was yes."
The researchers used a sample size of 283 people with an average age of 77 years old. The subjects completed a baseline brain scan, a sleep quality questionnaire, and cognitive tests that confirmed they were free of dementia.
The amount of amyloid buildup in their brains was measured over time and compared to sleepiness during the day that each of the subjects reported. At the end of the two-year study, the researchers discovered that the people who experienced the most drowsiness during the day were found to have more amyloids in their brains, particularly in the areas that were responsible for behavior, emotion, and memory retrieval.
Vemuri noted that the study was observational, and does not answer questions such as how much of poor sleeping habits is required to start the buildup of amyloids. However, the findings confirm that there is indeed a link between sleep and amyloids in the brain, and researchers are now studying if improving sleeping habits will reduce the accumulation of amyloids.
Recent News On Alzheimer's Disease
The new study follows up research that was also published in the Jama Neurology journal in January. The study also proposed poor sleep as an early indicator of Alzheimer's disease, but it focused not on sleepiness during the day but on fragmented sleeping patterns among adults over both night and day.
Meanwhile, a report from last month revealed the possibility that Alzheimer's disease is contagious as amyloid protein may be transmitted through infected surgical instruments.
However, garnering a lot of attention at the turn of the new year is a report that claimed a therapeutic drug, which was designed to treat Type 2 diabetes, was discovered to possibly reverse dementia that was triggered by Alzheimer's disease.