Sleep Restriction Alters Metabolic Regulation: The Link For Cognitive Impairment
Chronic sleep restriction induces metabolic alterations that lead to metabolic disorders, which in turn are known risk factors for developing AD . Acute and chronic sleep loss induces glucose intolerance and insulin resistance decrease insulin-like growth factor -1 and adiponectin levels and induce dyslipidemia and systemic low-grade inflammation in non-obese subjects .
How could the metabolic impairment caused by sleep restriction be the origin of cognitive disturbances? In the next section, we will discuss the metabolic signals associated with sleep restriction that have a direct effect on brain function and cognitive performance.
Is Sleep A Biomarker For Dementia
Doctors have been searching for early markers of dementia for years, in hopes of intervening to stop the deterioration of the brain. Beta-amyloid and tau proteins are predictive markers, but only recently have they become detectable with expensive PET scans that are not widely accessible.
Yet, while both proteins escalate in the brain in old age and perhaps to a greater extent in those with dementia, it is still unknown why some people with large burdens of amyloid and tau do not develop symptoms of dementia.
The leading hypothesis, the amyloid cascade hypothesis, is that amyloid is what happens first on the path to Alzheimers disease. Then, in the presence of amyloid, tau begins to spread throughout the cortex, and if you have too much of that spread of tau, that can lead to impairment and dementia, Winer said.
Walker added that, A lack of sleep across the lifespan may be one of the first fingers that flicks the domino cascade and contributes to the acceleration of amyloid and tau protein in the brain.
While Jagust has run PET scans on the brains of many healthy people, as well as those with dementia, many more subjects are needed to confirm the relationship between protein tangles and dementias like Alzheimers disease. Because PET scanners are currently expensive and rare, and because they require injection of radioactive tracers, other biomarkers are needed, Walker said.
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Lack Of Sleep May Increase Dementia Risk
A 30-year study explores the links between sleep deficits and dementia.
Short sleep duration during midlife could increase the risk of developing dementia later in life, an NIA study suggests. The results appeared online in Nature Communications.
In prior studies, both insufficient and excessive sleep have been linked to greater risk of developing dementia. Yet its been hard to determine whether these sleep changes contribute to the disease or simply reflect early symptoms. Many of the studies on sleep and dementia risk have followed participants for less than a decade and focused on people older than 65.
In the new study, researchers analyzed data from nearly 8,000 people in Britain starting at age 50. Participants reported how many hours they slept at night between 1985 and 2016, and some of the participants wore accelerometers to measure sleep time. Over the course of the 30-year study, 521 participants received a dementia diagnosis at an average age of 77.
Analysis of the data showed that people in their 50s and 60s who got 6 hours of sleep or less were at increased risk of developing dementia later. Compared to those getting 7 hours of sleep, people getting less rest each night were 30 percent more likely to be diagnosed with dementia.
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How To Help Somebody Who Is Experiencing Sundowning
Several methods can be used that may help to regulate the body clock of somebody experiencing sundowning.
- Bright light during the day coupled with darkness at night can improve the sleep-wake rhythm and reduce agitation.
- Physical activity during the day is a good way of strengthening the day/night cycle.
- Ensuring that the bedroom is cool during the night can lessen the likelihood of sleep fragmentation.
- Regular mealtimes can be an important time cue, signifying daytime.
- Limiting naps to one hour in the early afternoon can help impose a stronger day/night rhythm.
In long-term residential facilities, additional environmental factors that could negatively affect sleep include:
- frequent noise and light interruptions
- room lighting thatâs bright enough to suppress melatonin, in turn leading to disrupted sleep and further disruption of the circadian rhythm
- high room temperatures when sleeping that can lead to further fragmentation of sleep.
Itâs also important to establish whether thereâs an underlying reason behind the sleep problem . There can be numerous other causes of sleep problems, unrelated to those associated with dementia, including:
- obstructive sleep apnoea.
Addressing the points above may help to resolve some of the behaviours associated with sundowning but itâs also important to consider any medication that the person is taking.
What Is Sleep Pressure
Sleep pressure is the increasing need to sleep after being awake for a long time. The longer a person has been awake for, the more likely that they will feel sleepy, and the more deeply they are likely to sleep. As a person sleeps, the pressure to sleep gradually wears off and they become more likely to wake up.
Some stimulants, such as caffeine, work by blocking the chemicals that make a person feel sleepy.
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Caring For The Caregivers
When we talk about the effects of Alzheimerâs on sleep, itâs important not to overlook the fact that thereâs a whole army of caregivers who are also at high risk of experiencing sleep problems.
Caring for someone with Alzheimerâs is a full-time task and it can be both mentally and physically exhausting. As a caregiver, if your sleep is being compromised or youâre struggling to sleep, then you shouldnât feel as if youâre fighting a lone battle.
Surveys show that around 70% of caregivers for people with dementia report problems sleeping. The majority sleep for fewer than seven hours per night and up to a fifth use alcohol or medication to get to sleep. 21222324
These figures are worrisome and show that thereâs a definite need for greater support for caregivers of people with Alzheimerâs.
Encouragingly, thereâs plenty of research looking into the best ways to improve the sleep and overall quality of life of people in caregiving roles.
Research has shown that non-medical interventions are successful in improving sleep in caregivers and may additionally help to reduce stress levels. 21
Sleepstationâs drug-free and clinically validated sleep improvement programme can help you to identify your sleep problems and will give you the tools you need to get your sleep back on track.
Effects Of Good And Bad Sleep
At any age, getting a good nights sleep serves a number of important functions for our bodies and brains. Although our bodies rest during sleep, our brains are active. The process is not totally understood, but researchers think that sleep might benefit the brainand the whole bodyby removing metabolic waste that accumulates in the brain during wakefulness. In addition, it has been shown that some memories are consolidated, moving from short-term to long-term storage during periods of deep sleep. Other sleep stages may also influence memory and memory consolidation, research shows.
Disturbed sleepwhether due to illness, pain, anxiety, depression, or a sleep disordercan lead to trouble concentrating, remembering, and learning. A return to normal sleep patterns usually eases these problems. But in older people, disturbed sleep may have more dire and long-lasting consequences.
Scientists long believed that the initial buildup of the beta-amyloid protein in the brain, an early biological sign of Alzheimers, causes disturbed sleep, Dr. Mackiewicz said. Recently, though, evidence suggests the opposite may also occurdisturbed sleep in cognitively normal older adults contributes to the risk of cognitive decline and Alzheimers disease.
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Why Might A Person With Dementia Not Sleep Well
For a person with dementia, getting enough sleep can be a challenge. Sleeping well can be difficult for a person aged over 55, as the parts of the brain that control sleep may not work as well. An older person is likely to go to sleep earlier and may have difficulty sleeping through the night as much as they used to.
For more information, see Keeping active and involved. For ideas for enjoyable and engaging activities, see The Activities handbook.
What Is Sleep Disordered Breathing
Sleep disordered breathing is when someone has difficulty breathing when they are asleep. This may be because of obstructions to the airway, making breathing harder work. Sleep disordered breathing is sometimes called sleep apnoea.
People of all ages can be affected by sleep disordered breathing, but it is most common in older people and people with obesity. Some research has suggested that people who are affected by sleep disordered breathing may be at higher risk of cognitive decline or impairment. This is because sleep disordered breathing may cause damage to the brain due to changes of levels of oxygen and carbon dioxide in the blood. It may also change flow of blood to the brain.
Dementia Connect support lineDementia Connect support line.
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How Do The Body Clock And Sleep Pressure Work Together
Its much easier for a person to get to sleep when they have built up lots of sleep pressure during the day, and their body clock senses that its evening. This turns on both sleep systems at the same time, and should make the person feel sleepy at the right time.
If the person doesnt feel sleepy at night, their body clock may not be working well. They may also not have been awake for long enough to make the body need to sleep .
Aging And Cognitive Function
As it is mentioned, dementia is a common disease among the elderly but just preclinical impairments may be expected decades before certain diagnosis and cognitive decline may not be seen until discussed mechanisms including the accumulation of amyloid and NFT, inflammatory processes, BBB disruption, loss of synapses, and neuron loss have reached a certain threshold .
Therefore, based on the related mechanisms that can lead insomnia to the development of AD, and with attention to the high prevalence of insomnia and sleep disorders among the elderly age group, it can be assumed that insomnia has possible effects on AD pathogenesis and cognitive deficit in older adults with Alzheimers disease risk.
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Sleep Six To Eight Hours Each Night
In the first study, researchers at Harvard Medical School studied more than 2,800 individuals ages 65 and older participating in the National Health and Aging Trends Study to examine the relationship between their self-report of sleep characteristics in 2013 or 2014, and their development of dementia and/or death five years later. Researchers found that individuals who slept fewer than five hours per night were twice as likely to develop dementia, and twice as likely to die, compared to those who slept six to eight hours per night. This study controlled for demographic characteristics including age, marital status, race, education, health conditions, and body weight.
In the second study, researchers in Europe examined data from almost 8,000 participants from a different study and found that consistently sleeping six hours or less at age 50, 60, and 70 was associated with a 30% increase in dementia risk compared to a normal sleep duration of seven hours. The mean age of dementia diagnosis was 77 years. This study controlled for sociodemographic, behavioral, cardiometabolic, and mental health factors, although most participants were white, better educated, and healthier than the general population. In addition, approximately half of the participants had their sleep duration measured objectively using a wearable accelerometer a device that tracked their sleep using body movements which confirmed the questionnaire data.
The Myth Of The Need For 8 Uninterrupted Hours Of Sleep
Before the advent of the lightbulb, we went to sleep when it got dark. Interestingly, heading to bed around 7:00 or 8:00 p.m. meant that we had about 12 whole hours of restful time, so it was natural for us to wake up in the middle of the night.
The eight uninterrupted hours of sleep is a modern notion that, unfortunately, causes many sleepers a great deal of concern. But we should learn to rethink the way we sleep.
Whats ultimately most important about sleep is the quality of it, not the quantity.
Our modern lives simply dont let us get the rest we need. Laptops and smartphones naggingly chirp and glow at us all day long, ad nauseum. If we could truly unplug, we might find the peace of mind we need to get that rest.
But most of us dont have that luxury. So what can we do to get the sleep we so desperately need? It may simply mean accepting that waking up during the night is part of normal human physiology, says sleep psychologist Gregg Jacobs.
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Other Effects Of Alzheimers On Sleep
Some of the challenges that Alzheimers poses can result in an individual having reduced sleep quality, which may, in turn, worsen other symptoms of Alzheimers. For example, a lack of sleep can increase delusions, restlessness, and wandering, making sleeping more challenging.
People with Alzheimers may have difficulty communicating to their caregivers that something is wrong. For example, they may be unable to tell someone that they are experiencing pain. In this case, the pain may impair their sleep.
Having sufficient deep sleep and rapid eye movement sleep less deep sleep and REM sleep.
Other potential effects of Alzheimers on sleep include decreased physical activity and spending less time in natural sunlight.
Plaque Accumulation Can Cause Alzheimer’s
Researchers at the Bloomberg School of Public Health at Johns Hopkins asked 70 adults aged 53 to 91 to report how much they slept each night and how often they woke up or had sleep interruptions.
Then, participants underwent brain imaging where abnormal amounts of protein were found in those who reported problems sleeping.
Reaching the conclusion that the connection is real, noting that untreated sleep apnea has also been linked to Alzheimer’s risk demonstrated a relationship between poor sleep and cognitive decline in older adults.Lack of sleep and health risks
Five hours or less of sleep is not enough, while the idea that as you get older you need less sleep is not true.
People make the mistake of thinking that they only need enough sleep to “survive” Those who sleep little, regardless of their age, can have health problems not only mental , but also cardiovascular.
Lack of sleep has been linked to weight gain and increased risk of diabetes, heart disease, depression, etc.
Any sleep problem, such as not getting enough sleep, snoring, stop breathing while you are sleeping, waking up several times, you should schedule an appointment with a specialist.
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The Lack Of Sleep Can Bring Many Consequences Including Alzheimer’s Knows More About This Situation In The Following Blog
One study says, that not getting enough sleep or having a poor and interrupted sleep, could be related to the accumulation in the brain of an abnormal protein called beta-amyloid plaque, which is associated with Alzheimer’s disease.
Sleep can help “eliminate” waste products in the brain, including beta-amyloid plaque.
Sleep Disorders Commonly Associated With Alzheimers
Estimates suggest that up to half of all people with Alzheimerâs experience sleep problems. Sleep in Alzheimerâs tends to be fragmented and often distributed across a 24-hour period rather than following the regular rhythms of sleeping during the night and waking with the light.
Many people with Alzheimerâs sleep excessively during the day and struggle to sleep during the night-time hours. Itâs thought that this dysregulated sleep may result from damage to areas of the brain that control the body clock.
Our body clock refers to an internal system within our body that controls numerous physical processes related to wake and sleep. Itâs well established that the body clock is dysregulated in Alzheimerâs disease.
Studies have shown that for people with Alzheimerâs, neuronal loss and tangles of tau protein can be observed within the part of the brain responsible for controlling the body clock. 16
This part of the brain also regulates release of melatonin, the hormone that signals to our brains that itâs time to sleep.
In people with Alzheimerâs, melatonin levels are known to be reduced and, in more advanced Alzheimerâs, the timing of melatonin levels rising and falling has been shown to be disturbed.17
People with Alzheimerâs also commonly experience sleep disorders including:
- REM sleep behaviour disorder
- sleep problems arising from mood disorders.
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Poor Quality Sleep Could Increase Alzheimer’s Risk: Researchers
The study, published in the journal Brain, doesn’t show that poor sleep causes Alzheimer’s, but it adds one more piece to the puzzle of what causes dementia.
“When people had their slow-wave sleep disrupted, their amyloid levels increased by about 10 percent,” said Dr. Yo-El Ju of Washington University in St. Louis, who led the study.
Many other studies have linked poor sleep with earlier onset of dementia and especially Alzheimer’s. And a study published last week in the journal Neurology found that levels of amyloid, the protein that clogs the brains of Alzheimer’s patients, rose with poor sleep.
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This study sought to identify the most important phase of sleep. Ju and colleagues recruited 17 healthy adults for the study.
“What we did was allow people to sleep a normal amount of time, but we prevented them from getting deep sleep or what is called slow-wave sleep,” Ju told NBC News.
“When we interrupted just the slow-wave sleep part, they still had an increase in amyloid. So this tells us it’s getting the deep slow-wave sleep that’s important for reducing the levels of amyloid.”
More than 5 million Americans have Alzheimer’s, and the number is expected to grow as the population ages. There’s no cure, and treatments do not work well. Drugs such as Aricept, known also as donezepil, and Namenda can reduce symptoms for a time, but they do not slow the worsening of the disease.
“It was pretty harsh.”