Too much sleepiness predicts dementia risk
Between excessive daytime sleepiness in the elderly patient and the risk of dementia and Alzheimer's disease, beta-amyloid aggregates make the connection, explains this research from the Bloomberg School of Public Health at Johns Hopkins University ( Baltimore). This analysis of long-term data from older adults, presented in the journal Sleep, shows that chronic daytime sleepiness is indeed associated with a 3-fold increased risk of brain deposits of beta-amyloid.
This discovery adds to the growing body of evidence that poor quality sleep can promote the development of this form of dementia, but also that good quality nighttime sleep of sufficient duration can prevent the disease. While diet, exercise and cognitive activity are already widely recognized factors in the prevention of Alzheimer's disease, sleep also needs to be better considered, says lead author Dr Adam P Spira, associate professor in the Department of Mental Health at Johns Hopkins School: "Maybe we could treat patients with sleep disorders to avoid these negative cognitive effects."
This analysis of data from the Baltimore Longitudinal Study of Aging (BLSA), a study that followed the health of thousands of participants during aging, including a subgroup assessed by neuroimaging beginning in 1994, found identified 123 volunteers who reported daytime sleepiness or napping and looked to see if they were more positive for beta-amyloid deposits in the brain::::::::
- Before adjustment with possible confounding factors (which may promote daytime sleepiness), the analysis shows that daytime sleepiness is associated with a risk multiplied by 3 of beta-amyloid deposits, v the absence of fatigue felt during the day;
- after adjusting for these factors, the risk is still 2.75 times higher in subjects suffering from daytime sleepiness;
- the unadjusted risk of beta-amyloid deposition is also found to be approximately 2-fold higher in participants who regularly nap, but without true statistical significance after adjustment.
What are the reasons and meaning of such an association?
It remains unclear why daytime sleepiness is found to be correlated with beta-amyloid protein deposition. One hypothesis would be that sleepiness during the day could promote the formation of this protein in the brain. Another more likely hypothesis would be that disturbed sleep due to obstructive sleep apnea, for example – or other factors – could cause the formation of beta-amyloid plaques by a currently unknown mechanism. In the other direction, the researchers cannot exclude the fact that amyloid plaques present at the time of the sleep assessment can cause drowsiness. Studies conducted in the animal model of Alzheimer's have shown that nocturnal sleep restriction can lead to an increase in beta-amyloid protein in the brain and in cerebrospinal fluid. A few human studies have also suggested a link between lack of sleep and higher deposits of beta-amyloid in neural tissue.
Sleep disturbances are common in patients with Alzheimer's disease
This new study adds to the growing evidence that lack of sleep could actually contribute to the development of Alzheimer's disease. This suggests considering sleep quality as a modifiable risk factor, even if it means targeting sleep disorders, such as obstructive sleep apnea and insomnia, as well as social and individual factors that can induce a loss of sleep.
" If there is no cure yet for Alzheimer's disease, then we must do our best to prevent it ."
Are you more likely to get dementia if you sleep less?
Research is ongoing, but so far, a history of sleep trouble does seem to increase the risk of dementia for some people. One study suggests sleep deprivation could increase your dementia risk by 20%. In middle age, even getting less than 6 hours of sleep per night may increase your dementia risk in the future.
Can too much sleep cause dementia?
On the other hand, other researchers still say that getting more than 9 hours of sleep could indicate a higher risk of dementia or any Alzheimer's association. According to a study of more than 5,000 Latino adults between 45 and 75 years old, too much sleep was linked to decreased memory and episodic learning.
Can daytime sleepiness predict Alzheimer's?
In a new study, researchers have shown that excessive sleepiness during the day time among elderly who had normal mental acuity and cognitive powers is associated with the buildup of amyloid plaques in the brain that is typical of Alzheimer's disease.
What is the strongest risk factor for dementia?
The greatest known risk factor for Alzheimer's and other dementias is increasing age, but these disorders are not a normal part of aging. While age increases risk, it is not a direct cause of Alzheimer's. Most individuals with the disease are 65 and older. After age 65, the risk of Alzheimer's doubles every five years.
Can you avoid dementia?
There's no certain way to prevent all types of dementia, as researchers are still investigating how the condition develops. However, there's good evidence that a healthy lifestyle can help reduce your risk of developing dementia when you're older.
At what age does dementia usually start?
The risk rises as you age, especially after age 65. However, dementia isn't a normal part of aging, and dementia can occur in younger people. Family history. Having a family history of dementia puts you at greater risk of developing the condition.
What is constant sleepiness a symptom of?
The most common causes of excessive daytime sleepiness are sleep deprivation, obstructive sleep apnea, and sedating medications. Other potential causes of excessive daytime sleepiness include certain medical and psychiatric conditions and sleep disorders, such as narcolepsy.
Why do Alzheimer patients want to sleep so much?
The lethargy that many Alzheimer's patients experience is caused not by a lack of sleep, but rather by the degeneration of a type of neuron that keeps us awake, according to a study that also confirms the tau protein is behind that neurodegeneration.
What does excessive sleepiness in elderly mean?
Excessive sleepiness in older adults is often multifactorial and may signal an underlying sleep disorder, chronic medical condition, undiagnosed mood disorder, or side effects of medications. It is associated with increased risk for cognitive decline and dementia in the elderly.
Does sleeping more than 8 hours cause dementia?
Overall, those who slept more than nine hours were twice as likely to develop dementia than those who slept nine hours or less. Of the 96 people who reported sleeping more than nine hours, 19 developed dementia, or about 20 percent, compared to 215 of the 2,361 people who slept nine hours or less, or about 9 percent.
Does too much sleep cause cognitive decline?
Sleeping nine hours or more (long sleep) was also linked to cognitive problems, especially in decision making. And both short and long sleep were associated with higher body mass index (a measurement of body fat), more depressive symptoms, and more napping, compared with people who got seven or eight hours of sleep.
What sleep position is linked to dementia?
A 2019 study published in Journal of Alzheimer's Disease, showed among 165 participants (45 with diagnosed neurodegenerative disease, 120 controls) a supine sleep position (on back, head at body level) for more than 2 hours per night increased the risk of dementia by almost four times (3.7 times greater).
Does melatonin prevent dementia?
Most people associate melatonin with sleep. But melatonin may also play a role in protecting against neurodegeneration from dementia.
How much sleep do you need to prevent dementia?
Researchers found that individuals who slept under five hours per night were twice as likely to develop dementia compared to those who slept six to eight hours per night.
