Common sleeping pill may reduce Alzheimer’s protein buildup, study finds: ScienceAlert

There’s still a lot we don’t know about Alzheimer’s disease, but researchers are enthusiastically exploring the link between poor sleep and worsening of the disease.

In a study published in 2023, scientists found that using sleeping pills to get some sleep could reduce the buildup of toxic clumps of protein in the fluid that cleanses the brain each night.

Researchers at Washington University in St. Louis found that people who took suvorexant, a common treatment for insomnia, for two nights at a sleep clinic had a slight drop in two proteins, beta-amyloid and tau, which accumulate in Alzheimer’s disease.

Although short and involving a small group of healthy adults, the study provides an interesting demonstration of the link between sleep and molecular markers of Alzheimer’s disease.

Sleep problems may be a warning sign of Alzheimer’s disease that precedes other symptoms, such as memory loss and cognitive decline. And by the time symptoms first appear, abnormal levels of beta-amyloid peak near their peak, forming clumps called plaques that clog brain cells.

Researchers believe that promoting sleep could be a way to prevent Alzheimer’s disease, by allowing the sleeping brain to get rid of leftover proteins and other waste from the day.

Although sleeping pills can help in this regard, “it would be premature for people who fear developing Alzheimer’s disease to interpret this as a reason to start taking suvorexant every night,” said neurologist Brendan Lucey , of the Sleep Medicine Center at the University of Washington, who led the research.

The study lasted just two nights and involved 38 middle-aged participants who showed no signs of cognitive impairment and had no sleep problems.

Using sleeping pills for extended periods of time is also not an ideal solution for those who are sleep deprived, as it is quite easy to become dependent on them.

Sleeping pills can also put people into shallower periods of sleep rather than deep sleep stages. This could be problematic, as previous research by Lucey and colleagues has found a link between poorer quality slow-wave sleep and high levels of tau and amyloid-beta protein tangles.

In their latest study, Lucey and colleagues wanted to see if improving sleep using sleeping pills could reduce levels of tau and beta-amyloid in the cerebrospinal fluid that bathes the brain and spinal cord. Previous research shows that even a single night of disrupted sleep can increase beta-amyloid levels.

A group of volunteers aged 45 to 65 received one of two doses of suvorexant or a placebo pill, an hour after researchers drew their spinal fluid to collect a small sample.

The researchers continued to collect samples every two hours for 36 hours while the participants slept and during the following day and night, to measure changes in protein levels.

There was no difference in sleep between the groups, yet beta-amyloid concentrations were reduced by 10 to 20 percent with a dose of suvorexant usually prescribed for insomnia, compared with a placebo.

The higher dose of suvorexant also momentarily reduced levels of hyperphosphorylated tau, a modified form of the tau protein linked to tau tangle formation and cell death.

However, this effect was only seen with certain forms of tau, and tau concentrations returned within 24 hours of taking the sleeping pill.

“If you can reduce the phosphorylation of Tau protein, there would potentially be less tangle formation and less neuronal death,” Lucey said, still hoping that future studies of older people testing sleeping pills for months could possibly measure a lasting effect on protein levels (while noting any downsides of sleeping pills).

Of course, all of this relies on our understanding of the causes of Alzheimer’s disease.

The leading theory, that abnormal protein clumps are the cause of Alzheimer’s pathology, has come under increased scrutiny in recent times after decades of research aimed at reducing amyloid levels failed to materialize. are translated into no useful medication or treatment that actually prevents or slows the disease. This has prompted researchers to rethink how Alzheimer’s disease develops.

In other words, sleeping pills may help some people get some sleep, but using them as a preventative treatment to ward off Alzheimer’s disease remains a fuzzy prospect that relies on a now-shaky hypothesis of Alzheimer’s pathology.

That said, there is growing evidence linking sleep disorders to Alzheimer’s disease, a condition for which there is no treatment. Lucey says that improving sleep hygiene and seeking treatment for sleep problems such as sleep apnea are two wise approaches to improving overall brain health at any age.

“I hope that we will eventually be able to develop drugs that take advantage of the link between sleep and Alzheimer’s disease to prevent cognitive decline,” Lucey said. But he admitted: “We’re not there yet.” »

The study was published in Annals of Neurology.

An earlier version of this article was published in April 2023.