A new study by researchers at Washington University in St. Louis said sleeping aids may help slow and stall the progress of Alzheimer's disease. File Photo by Claudio Scott/Pixabay
April 20 (UPI) -- A new study completed by researchers at Washington University in St. Louis found that people who took sleeping pills saw a drop in levels of key Alzheimer's proteins, suggesting a link between quality sleep and slowing the progression of the brain disease.
Details of the research in the small study were published Thursday in the scientific journal Annals of Neurology.
Researchers conducted a two-night study in which people took a sleeping pill before bed and were tested for Alzheimer's proteins. The sleeping aid they used, suvorexant, has been approved by the Food and Drug Administration for insomnia.
There have long been hints in the medical community that such sleep medications can be beneficial in the slowing or stalling Alzheimer's, but there has not been extensive research done on its possible impact.
Washington University researchers recruited 38 participants ages 45 to 65 and with no cognitive impairments to undergo a two-night sleep study. The participants, broken up into three groups, were given a lower dose and higher dose of suvorexant, while the third was given a placebo.
"Amyloid levels dropped 10% to 20% in the cerebrospinal fluid of people who had received the high dose of suvorexant compared to people who had received placebo, and the levels of a key form of tau known as hyperphosphorylated tau dropped 10% to 15%, compared to people who had received placebo," the researchers said.
"Both differences are statistically significant. There was not a significant difference between the people who received a low dose of suvorexant and those who received the placebo.
"By 24 hours after the first dose, hyperphosphorylated tau levels in the high-dose group had risen, while amyloid levels remained low compared to the placebo group."
The study's senior author Brendan Lucey, an associate professor of neurology and director of Washington University's Sleep Medicine Center, said while the testing was small, the "proof-of-concept study" could be enough to encourage further research on the impact of sleeping aid on the progression of Alzheimer's.
"It would be premature for people who are worried about developing Alzheimer's to interpret it as a reason to start taking suvorexant every night," Lucey said. "We don't yet know whether long-term use is effective in staving off cognitive decline, and if it is, at what dose and for whom.
"Still, these results are very encouraging. This drug is already available and proven safe, and now we have evidence that it affects the levels of proteins that are critical for driving Alzheimer's disease."
Researchers said that suvorexant belongs to a class of insomnia medications known as dual orexin receptor antagonists.
"Orexin is a natural biomolecule that promotes wakefulness. When orexin is blocked, people fall asleep. Three orex ininhibitors have been approved by the FDA, and more are in the pipeline," the researchers said.
Lucey said one of the more exciting parts of the study was the lowering amyloid levels, which has a connection with Alzheimer's.
"If we can lower amyloid every day, we think the accumulation of amyloid plaques in the brain will decrease over time," Lucey said.
"And hyperphosphorylated tau is very important in the development of Alzheimer's disease because it's associated with forming tau tangles that kill neurons. If you can reduce tau phosphorylation, potentially there would be less tangle formation and less neuronal death."
He said in the near future studies will need to have people taking such sleeping medications for months, at least, and measuring the effect on amyloid and tau over an extended period of time.
"We're also going to be studying participants who are older and may still be cognitively healthy, but who already have some amyloid plaques in their brains," Lucey said. "This study involved healthy middle-aged participants; the results may be different in an older population.
"I'm hopeful that we will eventually develop drugs that take advantage of the link between sleep and Alzheimer's to prevent cognitive decline. We're not quite there yet. At this point, the best advice I can give is to get a good night's sleep if you can, and if you can't, to see a sleep specialist and get your sleep problems treated."