Small changes in your sleep pattern may offer an early clue about future dementia risk, according to new research.
During a normal night’s rest, the brain briefly slips into tiny moments of wakefulness known as micro awakenings — fleeting episodes that often last only seconds.
These brief interruptions are considered a routine part of healthy sleep, with most people experiencing many of them each night without any memory of waking up.
But scientists in Europe now say a higher number of micro awakenings during the night may be linked to a greater likelihood of cognitive decline later in life.
The findings come from a study that followed 500 adults for as long as seven years and found that middle-aged participants with more frequent micro awakenings were also more likely to carry genetic markers associated with an increased risk of Alzheimer’s disease.
Among those markers was the APOE4 gene, which has been associated with a 60 percent higher chance of receiving an Alzheimer’s diagnosis by the age of 85.
“These micro awakenings are therefore not insignificant,” said study co-author Dr Puneet Talwar, a sleep researcher at the University of Liege in Belgium.
He added that some sleep profiles may encourage the build-up of proteins involved in Alzheimer’s disease and could point to heightened vulnerability.
Scientists have revealed a subtle shift in how you sleep that could reveal you are at higher risk of suffering from dementia
About seven million Americans are living with Alzheimer’s, estimates suggest, but that number is expected to nearly double over the next 24 years.
Scientists have warned repeatedly that sleep disruption, poor quality sleep and daytime sleepiness may all raise the risk of Alzheimer’s disease, possibly because it can cause harmful proteins to build-up in the brain. It was not clear how the genetic markers may disrupt sleep.
The team behind the paper said their research may have revealed a potential method for detecting Alzheimer’s risk years before symptoms appear. Typically, the condition is not diagnosed until someone turns 65 years or older.
In the study, published in the journal Sleep, scientists tracked 453 adults with an average age of 22 years and 87 middle-aged adults with an average age of 59 years.
Overall, younger adults slept for about seven hours and 30 minutes per night while middle-aged adults slept for about six hours and 30 minutes per night.
The younger participants experienced about 250 micro awakenings every night while older participants experienced about 180 micro awakenings.
Chris Hemsworth has the APOE gene, dubbed the ‘Alzheimer’s gene.’ He is shown attending the European premiere of Transformers One at Cineworld Leiscester Square on September 19, 2024
After analyzing the data, the researchers said that those experiencing more micro awakenings every night were more likely to have genes that raised their risk of suffering from Alzheimer’s.
They also used brain scans to analyze the coeruleus locus, a region in the brainstem that controls the sleep-wake cycle.
The team found that sleep quality, the ability to fall asleep and sleep depth, was dependant on the proper functioning of the coeruleus locus.
It was also important for rapid-eye movement sleep, the phase of sleep in which dreaming and memory consolidation occurs.
Previous research has also shown that it is one of the first places where abnormal protein deposits appear.
‘Sleep could become an accessible marker for the early identification of vulnerable individuals,’ said Gilles Vandewalle, a sleep researcher and co-author of the study.
And Lucie Leroux, head of French-speaking activities at the Stop Alzheimer’s Foundation, which funded the research, added: ‘This research shows that sleep is not only an indicator of health, but also a potential lever for intervention.
