Thirty-eight people took part in a study to investigate the effects of a sleep medication on Alzheimer's-related proteins in their cerebrospinal fluid. The pills showed promise in combating the substances that lead to the harmful tangles and plaques in the brain that contribute to the disease, but larger more comprehensive studies are needed to confirm the results.
It's been known that there's a bit of a Catch-22 involved when it comes to sleep and Alzheimer's disease. Poor sleep patterns have been linked to the development of the condition and, once someone has Alzheimer's disease, their sleep can be disrupted even many years before the symptoms of cognitive decline appear. Both sides of this coin are related to the build up of tau and amyloid beta, proteins that form plaques and tangles in the brain that harm neurons and lead to the development of Alzheimer's.
Interested in finding out if sleep medication might be a possible way to mitigate the effect of sleeplessness on the development of Alzheimer's disease, researchers at Washington University School of Medicine divided 38 study participants into three groups and conducted a two-night sleep study. The first group, the control, took no medication. The second group took a low dose of suvorexant (10 mg), an insomnia medication that blocks orexin, a molecule in the body that naturally keeps us awake. The third group took a higher dose of suvorexant (20 mg).
Throughout the study, the participants had small amounts of their cerebrospinal fluid removed every two hours, which likely didn't lead to very restful evenings. The researchers found that in the group taking the higher dose of suvorexant, their levels of a type of tau known as hyperphosphorylated tau dropped by 10-15% and their levels of amyloid dropped 10-20%. The group on the lower dose of the medication did not show a statistically significant drop in either protein.
Despite the promise of using suvorexant hinted at here, the researchers are quite clear that this was a very small study that was used for investigatory purposes only rather than as any kind of validation that the medication can help ward off Alzheimer's disease.
“This is a small, proof-of-concept study," said senior author Brendan Lucey, an associate professor of neurology and director of Washington University’s Sleep Medicine Center. "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. 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.”
Also, when the sleeping pills began to wear off, the levels of tau and amyloid went back to their previous levels, so staying on sleeping pills to keep them knocked back is obviously not a valid long-term strategy. And it's worth pointing out that the participants in this study were all healthy middle-aged adults, so further research is planned on other populations, including those who are older. Still Lucey and his team are hopeful that the future studies both on different groups of people and on the long-term effects of the nightly use of orexin inhibitors will add to the ever-growing body of research regarding the fight against Alzheimer's disease.
“I’m hopeful that we will eventually develop drugs that take advantage of the link between sleep and Alzheimer’s to prevent cognitive decline,” Lucey said. “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.”
The study has been published in the journal Annals of Neurology.
