Links among poor sleep, high blood pressure, gut microbiome discovered
September 2, 2020
Science Daily/University of Illinois at Chicago
In the first study of its kind, University of Illinois Chicago researchers have found associations among disrupted sleep, elevated blood pressure and changes in the gut microbiome.
The research aimed to determine whether a 28-day period of disrupted sleep changed the microbiota in rats. The gut microbiota refers to the collection of microorganisms living in the intestines. The researchers also sought to identify biological features associated with undesirable arterial blood pressure changes.
The results were published in Physiological Genomics.
Using rats, the researcher disrupted their sleep periods. Rats are nocturnal, so the experiments were designed to interfere with their daytime sleep periods.
Telemetry transmitters measured the rats' brain activity, blood pressure and heart rate. Fecal matter also was analyzed to examine changes in the microbial content.
The research idea was generated by several of the paper's authors who are or have been health care providers with night-shift schedules.
"When rats had an abnormal sleep schedule, an increase in blood pressure developed -- the blood pressure remained elevated even when they could return to normal sleep. This suggests that dysfunctional sleep impairs the body for a sustained period," Maki said.
Undesirable changes also were found in the gut microbiome -- the genetic material of all bacteria living in the colon.
Contrary to her initial hypothesis, Maki found that the gut microbiome changes did not happen immediately, but instead took a week to show unfavorable responses such as an imbalance among different types of bacteria including an increase in microbes associated with inflammation.
"When the sleep disruption stopped, everything did not come back to normal immediately," Maki said. "This research shows a very complex system with the presence of multiple pathological factors."
This was initial research, and studies will continue to examine pathways involving the gut microbiome and metabolites produced by gut bacteria. The researchers will see exactly how sleep characteristics are changed and how long blood pressure and gut microbiome alterations persist. Researchers will then determine how this information translates to humans.
"We hope to find an intervention that can help people who are at risk for cardiovascular disease because of their work and sleep schedules. People will always have responsibilities that interrupt their sleep. We want to be able to reduce their risk by targeting the microbiome with new therapies or dietary changes," Fink said.
https://www.sciencedaily.com/releases/2020/09/200902182439.htm
Sleep history predicts late-life Alzheimer's pathology
Findings suggest novel, sleep-based diagnosis and treatment methods
June 18, 2019
Science Daily/Society for Neuroscience
Sleep patterns can predict the accumulation of Alzheimer's pathology proteins later in life, according to a new study of older men and women published in JNeurosci. These findings could lead to new sleep-based early diagnosis and prevention measures in the treatment of Alzheimer's disease.
Alzheimer's disease is associated with disrupted sleep and the accumulation of tau and proteins in the brain, which can emerge long before characteristic memory impairments appear. Two types of hippocampal sleep waves, slow oscillations and sleep spindles, are synced in young individuals, but have been shown to become uncoordinated in old age.
Matthew Walker, Joseph Winer, and colleagues at the University of California, Berkeley found a decrease in slow oscillations/sleep spindle synchronization was associated with higher tau, while reduced slow-wave-activity amplitude was associated with higher ?-amyloid levels.
The researchers also found that a decrease in sleep quantity throughout aging, from the 50s through 70s, was associated with higher levels of ?-amyloid and tau later in life. This means that changes in brain activity during sleep and sleep quantity during these time frames could serve as a warning sign for Alzheimer's disease, allowing for early preventive care.
https://www.sciencedaily.com/releases/2019/06/190618102725.htm
Trouble Sleeping? It May Affect Your Memory Later On
February 14, 2012
Science Daily/American Academy of Neurology
The amount and quality of sleep you get at night may affect your memory later in life, according to research that was recently released and will be presented at the American Academy of Neurology's 64th Annual Meeting in New Orleans April 21 to April 28, 2012.
"Disrupted sleep appears to be associated with the build-up of amyloid plaques, a hallmark marker of Alzheimer's disease, in the brains of people without memory problems," said study author Yo-El Ju, MD, with Washington University School of Medicine in St. Louis and a member of the American Academy of Neurology. "Further research is needed to determine why this is happening and whether sleep changes may predict cognitive decline."
Researchers tested the sleep patterns of 100 people between the ages of 45 and 80 who were free of dementia. Half of the group had a family history of Alzheimer's disease. A device was placed on the participants for two weeks to measure sleep. Sleep diaries and questionnaires were also analyzed by researchers.
After the study, it was discovered that 25 percent of the participants had evidence of amyloid plaques, which can appear years before the symptoms of Alzheimer's disease begin. The average time a person spent in bed during the study was about eight hours, but the average sleep time was 6.5 hours due to short awakenings in the night.
The study found that people who woke up more than five times per hour were more likely to have amyloid plaque build-up compared to people who didn't wake up as much. The study also found those people who slept "less efficiently" were more likely to have the markers of early stage Alzheimer's disease than those who slept more efficiently. In other words, those who spent less than 85 percent of their time in bed actually sleeping were more likely to have the markers than those who spent more than 85 percent of their time in bed actually sleeping.
"The association between disrupted sleep and amyloid plaques is intriguing, but the information from this study can't determine a cause-effect relationship or the direction of this relationship. We need longer-term studies, following individuals' sleep over years, to determine whether disrupted sleep leads to amyloid plaques, or whether brain changes in early Alzheimer's disease lead to changes in sleep," Ju said.
"Our study lays the groundwork for investigating whether manipulating sleep is a possible strategy in the prevention or slowing of Alzheimer disease."
http://www.sciencedaily.com/releases/2012/02/120214171036.htm