Researchers at Johns Hopkins University Bloomberg School of Public Health have recently carried out a study and found out that excessive daytime sleepiness is associated with higher chances of suffering from Alzheimer’s in old age. This long term-study analyzed data collected from aging adults, and the results suggest those who reported being sleepy during the day have nearly 3 times more chances to have brain deposits of beta-amyloid. Beta-amyloid is a brain protein that is associated with memory-robbing disease, and it’s considered a hallmark for Alzheimer’s disease.
The results of the study were published in September 2018 in the journal SLEEP. This study contributes to other evidence that poor sleep encourages the development of dementia, and also indicates that proper and regular rest may help prevent Alzheimer’s disease.
Dr. Spira, Ph.D., associate professor in the Department of Mental Health at the Johns Hopkins Bloomberg School of Public Health, says that factors such as diet, exercise, and cognitive activity severely contribute to the development of Alzheimer’s. The results of their study indicate that poor sleep may contribute to Alzheimer’s disease just as above mentioned factors. Therefore, treating sleep issues may also help avoid these adverse long-term outcomes.
The study used data from a long-term study that started in 1958 and has gathered sleep data about thousands of volunteers. As part of the study, volunteers had to fill a questionnaire between 1991 and 2000 and answer yes or no to the following questions:
- Do you often feel drowsy or fall asleep during the daytime when you want to be awake?
- Do you nap?
- How much do your nap? (daily, 1-2 times a week,3-5 times a week, rarely or never)
In 1994, some participants also received neuroimaging assessments. In 2005 some subjects received PET scans by using PiB (Pittsburgh compound B). PiB can identify beta-amyloid plaques in neuronal tissue, also known as an early sign of Alzheimer’s disease.
The scientists were able to identify 123 participants of the study who answered the earlier questions and had a PET scan with PiB 16 years later. This data was analyzed again to see if there was any correlation with their napping habits or daytime sleepiness, and they found out all 123 participants were positive for beta-amyloid deposition in their brains.
After adjusting the demographic factors that could influence daytime sleepiness, the results showed that people are sleepy during the day are 2.75 times more likely to have a beta-amyloid deposition in the brain than those who don’t.
Scientists still don’t know how daytime sleepiness is associated with the deposition of beta-amyloid protein. Most likely, sleepiness somehow triggers this protein to form in the brain. It’s even possible that the amyloid plaques were present at the time of sleep assessment, and that they are the ones that cause the sleepiness.
Since there is still no cure for Alzheimer’s, we have to do our best to prevent it. If prioritizing is one of the ways to prevent or slow down this severe condition, then we should definitely focus on getting more quality rest.