Your Sleep May Hide an Early Clue to Alzheimer's Risk, Study Finds

Researchers at the University of Liege (ULiege), supported by the Stop Alzheimer's Foundation, are investigating whether the sleeping brain may contain clues to Alzheimer's vulnerability years before memory problems become noticeable. Scientists from ULiege's GIGA Neurosciences lab examined sleep patterns in more than 500 healthy people and found that, among middle-aged participants, more frequent nighttime micro-awakenings were associated with a higher genetic risk of developing Alzheimer's disease; no such link appeared among younger adults. The findings are published in the journal Sleep.

The researchers calculated a polygenic risk score — a single figure summarizing the combined influence of a person's genes on their probability of developing Alzheimer's — for participants who were mostly young adults aged 18 to 31, alongside an older group aged 50 to 69. The measured risk remained low and cannot determine whether any particular person will develop the disease, but among the older group, those with more frequent micro-awakenings — brief bursts of brain activity that interrupt sleep without fully waking someone — tended to also have higher genetic risk, despite being healthy and symptom-free.

"These micro-awakenings are therefore not insignificant," said Puneet Talwar, a researcher at the GIGA ULiege lab. "Certain profiles could promote the accumulation of proteins involved in Alzheimer's disease and be associated with increased vulnerability." The researchers also examined the locus coeruleus, a brainstem region roughly the size of a grain of rice that helps regulate wakefulness, attention and sleep.

The locus coeruleus is among the earliest brain regions where abnormal protein deposits linked to Alzheimer's can appear, deposits that may begin accumulating as early as adolescence. "This region is difficult to observe, but it appears to play a role in the early mechanisms linked to the disease," said Gilles Vandewalle, co-director of ULiege's GIGA CRC In Vivo Imaging platform. A 2025 study using a 7-Tesla MRI scanner at the ULiege platform found that sleep quality measures were associated with the condition of the brainstem from a young age, and that healthy functioning of the locus coeruleus was related to the quality of REM sleep, a stage important for memory.

"Sleep could become an accessible marker for the early identification of vulnerable individuals," Vandewalle said. Lucie Leroux, head of French-speaking activities at the Stop Alzheimer's Foundation, said the research shows sleep is not only an indicator of health but also a potential lever for intervention. More than 220,000 people in Belgium are affected by Alzheimer's disease.