Could subtle changes during sleep reveal a person’s vulnerability to Alzheimer’s disease years before memory problems appear? Researchers at the University of Liège (ULiège), supported by the Stop Alzheimer’s Foundation, are investigating whether sleep patterns may provide early clues about Alzheimer’s disease risk.
Scientists at the University of Liège’s GIGA Neurosciences research center analyzed sleep patterns in more than 500 healthy adults. Among middle-aged participants, a higher frequency of nighttime microawakenings was associated with a greater genetic risk of developing Alzheimer’s disease. This association was not observed in the younger participants.
The findings, published in the journal Sleep, suggest that sleep monitoring could eventually help researchers identify people who may be more vulnerable to Alzheimer’s disease before noticeable symptoms develop.
Searching for early clues to Alzheimer’s disease
Researchers have long studied the relationship between sleep disturbances and neurodegenerative diseases. The University of Liège study adds to this work by suggesting that connections between sleep and Alzheimer’s disease risk may emerge years before memory loss and other clinical symptoms.
Because genetics contributes to—but does not completely determine—Alzheimer’s disease risk, the researchers calculated each participant’s polygenic risk score. This score combines the effects of multiple genetic variants associated with the likelihood of developing a particular disease.
The study included more than 500 healthy participants. Most were young adults between 18 and 31 years old, while a second group included adults between 50 and 69. The polygenic risk scores used in the research were relatively low and cannot predict whether any individual will eventually develop Alzheimer’s disease.
The researchers then compared the participants’ genetic risk estimates with several characteristics of their sleep.
Nighttime microawakenings and Alzheimer’s risk
The analysis identified an association between genetic risk for Alzheimer’s disease and the frequency of nocturnal microawakenings. These brief bursts of brain activity can interrupt normal sleep cycles without fully waking a person.
No relationship between microawakenings and Alzheimer’s disease risk was found among the younger participants. However, a different pattern appeared in the middle-aged group. Healthy participants who experienced more frequent microawakenings also tended to have a higher genetic risk for Alzheimer’s disease, despite having no symptoms.
Puneet Talwar, a researcher at the GIGA ULiège Institute, explained that these subtle nighttime arousals may be more than harmless disruptions. According to the researchers, this sleep profile could potentially be linked to processes involved in the accumulation of proteins associated with Alzheimer’s disease and increased neurological vulnerability.
A small brain region draws researchers’ attention
The research team also examined the locus coeruleus, a tiny region deep within the brainstem that is approximately the size of a grain of rice. This area helps regulate wakefulness, attention, and sleep.
“This region is difficult to observe, but it appears to be involved in early mechanisms associated with the disease,” said Gilles Vandewalle, co-director of the GIGA CRC In Vivo Imaging technology platform and a research director at the FNRS Fund for Scientific Research at ULiège.
In 2025, a preliminary study using the ULiège platform’s 7-tesla MRI scanner enabled researchers to examine the locus coeruleus in greater detail. The team found that sleep characteristics, including how quickly and how deeply a person falls asleep, were associated with brainstem changes that may begin early in life.
The researchers also reported that healthy locus coeruleus function was linked to the quality of REM sleep, a sleep stage that plays an important role in memory processing.
The locus coeruleus is of particular interest in Alzheimer’s disease research because it is one of the earliest brain regions where abnormal protein deposits may develop. These deposits can begin accumulating as early as adolescence, although scientists do not yet fully understand the significance of these early changes.
Could sleep become an early marker of Alzheimer’s disease?
Taken together, the findings highlight the potential of sleep research for the early screening and prevention of Alzheimer’s disease. In the future, sleep analysis could complement genetic testing, brain imaging, and other assessments to help identify people who may be vulnerable before symptoms become apparent.
“Sleep could be an accessible marker for the early identification of vulnerable individuals,” said Jill Vandewalle.
Researchers are also investigating whether improving sleep could help prevent or slow the progression of Alzheimer’s disease in people with a genetic predisposition.
“This study shows that sleep is not only an indicator of health, but also a potential target for intervention,” said Lucie Leroux, head of Francophone activities at the Stop Alzheimer’s Foundation.
More than 220,000 people in Belgium live with Alzheimer’s disease. However, the new findings show statistical associations rather than proof that specific sleep patterns cause or reliably predict the disease. Further research is needed to confirm the results, and the findings cannot currently determine whether a particular person will develop Alzheimer’s disease.
Nevertheless, the study offers another insight into brain changes that may occur long before Alzheimer’s disease becomes clinically apparent. It also underscores the importance of basic research aimed at understanding—and eventually predicting—the earliest stages of Alzheimer’s disease.
Source: www.sciencedaily.com