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Current study sleep disorders increase the risk of dementia
Can our sleep affect the risk of people being more likely to develop dementia? Researchers have now found that the time spent in the so-called REM sleep at night influences how high the risk of developing dementia is.
The researchers from Swinburne University of Technology and Boston University found in their current study that a shortened REM sleep period leads to an increased risk of developing dementia. The physicians published the results of their study in the journal "Neurology".
A disturbed sleep affects health, performance and concentration. Physicians have now found that sleep disorders can even affect the likelihood of developing dementia. (Image: Sven Vietense / fotolia.com) Effects of too short REM sleep phase
The experts have found that in the elderly, dementia can be predicted by measuring REM sleep. When people have a shorter REM sleep, the risk of dementia increases significantly. The new study found that a one-percent reduction in REM sleep results in a nine-fold increase in the chance of developing dementia. In other words, REM sleep is a predictor of dementia, explain the researchers.
What is the REM sleep phase?
During the REM phase of sleep, the eyes move faster and there is an increased brain activity. In addition, the pulse beats faster and the breathing speeds up. The so-called REM phase usually occurs one to one and a half hours after falling asleep. During the night, the cycles of sleep are repeated, so does the REM phase.
Physicians examined older subjects
For their study, the researchers examined a total of 321 people with an average age of 67 years. These subjects participated in the Framingham Heart Study in the US. During the examination, the physicians measured the sleep cycles of the participants. Later, the subjects were then medically monitored for an average period of twelve years.
32 subjects develop dementia during the study
During the period of follow-up, 32 people were diagnosed with some form of dementia. Alzheimer's disease was found in 24 of these participants. The dementia-developing subjects spent an average of 17 percent of their sleep time in REM sleep, compared to 20 percent of people who did not develop dementia, the researchers explain.
Other sleep phases are not associated with the development of dementia
After adjusting the results to age and gender, the researchers found that a lower percentage of REM sleep and a longer time to reach the stage of REM sleep are associated with an increased risk of dementia. Even after taking into account other factors that affect the risk of dementia or sleep, such as factors for heart disease, symptoms of depression, or the use of medication, the results were still similar, explain the physicians. It was also found that the other stages of sleep were not associated with an increased risk of dementia.
Which sleep phases are there?
REM sleep is the fifth stage of sleep and this phase occurs before dreaming. Sleep is divided into the following phases:
- Phase One: Light sleep
- Phase Two: The body begins to prepare for deep sleep
- Phase Three: Deep Sleep
- Phase Four: Deep Sleep
- Phase Five: REM sleep
Many people with dementia suffer from sleep disorders
Sleep disorders are widespread in people with dementia. So far, however, little was known about the different stages of sleep and their role in the development of dementia, the experts add. The scientists have therefore decided to find out which stages of sleep could be associated with the development of dementia. They found no link between dementia and a deep sleep, but an association between REM sleep and the risk of dementia was found.
Further research is needed
The next step is to determine which mechanisms of REM sleep lead to a greater risk of developing dementia, explain the researchers. Understanding the role of sleep in the onset of dementia could identify new ways to significantly improve dementia treatment in the future and delay or even completely prevent dementia, scientists hope. (As)