Researchers estimate that as many as 70
Not getting enough sleep every night can take its toll on the body by negatively affecting a person’s ability to concentrate and their mental health.
Past studies also show that sleep disorders can increase a person’s risk for several health issues, such as heart disease,
“Poor sleep quality and sleep disorders often appear years before other symptoms of dementia due to Alzheimer’s disease and related disorders become apparent,” David M. Holtzman, MD, the Barbara Burton and Reuben M. Morriss III Distinguished Professor of Neurology and scientific director of the Hope Center for Neurological Disorders at the Washington University School of Medicine told Medical News Today.
“Research from our lab and others has shown that disrupted sleep elevates levels of both
He is the senior author of a new study published in the journal
For this study, researchers focused on a sleep disorder medication called lemborexant, sold under the brand name Dayvigo.
“Lemborexant belongs to a class of sleep medications called dual orexin receptor antagonists,” Samira Parhizkar, PhD, instructor at Washington University School of Medicine, and first author of this study, explained to MNT. “These drugs work by blocking orexin — a protein in the brain that keeps us awake and alert.”
“By blocking the orexin signaling, the medication allows sleep to occur quickly and more easily,” Parhizkar continued. “In other words, if your brain is like a light switch that keeps flicking on when you are trying to sleep, lemborexant helps turn that switch off, so your brain and body gets the rest it needs.”
Scientists used lemborexant to treat a model of mice that were genetically prone to having tau buildup in the brain.
“In the healthy brain, tau protein acts as a ‘track’ that helps support the shape of cells and helps move nutrients and signals where they need to go,” Holtzman detailed.
“In Alzheimer’s and a group of neurodegenerative disorders primarily affected by abnormal tau called tauopathies, abnormal tau loses its shape, integrity and therefore cellular functionality leading to tau tangles. The progressive build of these tau tangles leads to nerve cell death that contributes to memory loss, confusion among other cognitive symptoms of Alzheimer’s disease,” he explained.
At the study’s conclusion, researchers found treating the mice with lemborexant helped to prevent the buildup of tau in the brain, reducing the inflammatory brain damage that tau buildup is known to cause in Alzheimer’s disease.
“The detrimental increase of abnormal tau is closely associated with heightened inflammatory damage in the brain,” Parhizkar said. “Research from our lab and others has demonstrated that inflammation in the brain is a significant factor contributing to the brain damage seen in neurodegenerative diseases like Alzheimer’s.”
“Consequently, by decreasing both the abnormal buildup of tau and inflammatory damage, lemborexant may be highly effective in safeguarding the brain from these sources of injury,” she added.
Additionally, scientists discovered that mice treated with the sleep aid had a 30–40% larger hippocampus volume compared to those not treated with the medication.
“The larger hippocampal volume indicates reduced brain damage and cellular loss in mice treated with lemborexant compared to those given vehicle control,” Holtzman said. “In the latter group, abnormal tau protein continued to accumulate in the brain, resulting in cell damage, death, and therefore shrinkage of the hippocampus typically observed with neurodegeneration.”
MNT also had the opportunity to speak with Gary Small, MD, chair of psychiatry at Hackensack University Medical Center in New Jersey, about this study.
Small, who was not involved in the current research, commented that the findings from this new study are consistent with previous research linking restful sleep with better cognitive health.
“For example, my research team found that sleep quality is related to both objective measures of sustained attention and self-awareness of memory decline, suggesting that interventions for improving sleep quality may contribute not only to improving the ability to focus on a particular task but also in reducing memory complaints,” he told us.
“Other work has shown that restful sleep reduces brain amyloid and inflammation, which may explain why sleep benefits cognition. The Washington University team now sheds additional light on an underlying link between insomnia and cognitive impairment: accumulation of tau protein, particularly in brain regions controlling memory,” Small added.
According to him:
“Nearly 40% of people in the U.S. complain of insomnia, which can lead to daytime fatigue, memory issues, difficulty concentrating, anxiety, depression, irritability, and disrupted work and social activities. Available medicines may lead to dependency and pose such side effects as daytime drowsiness, dizziness, headache, unusual dreams, and memory problems. Finding innovative treatments that reduce tau accumulation in the brain and promote restful sleep would have the dual effect of combating Alzheimer’s disease and chronic insomnia”
Still, Small cautioned that, while “[t]his study is encouraging […] findings in an animal model must move forward to clinical trials of human volunteers to determine the safety and effectiveness of this potential treatment.”
