Scientists have linked waking up at night with a genetic risk of Alzheimer's disease

Waking up during sleep, unnoticeable to the person himself, may be associated with a genetic predisposition to Alzheimer's disease. Scientists have studied the sleep patterns of more than 500 healthy people. In middle-aged participants, more frequent short-term awakenings at night were associated with an increased genetic risk of the disease, although they did not have any symptoms of Alzheimer's. Why sleep can change long before memory problems appear and what role a small part of the brain plays in this is in the Izvestia material.

Frequent awakenings are associated with a genetic risk

Researchers from the GIGA Neurosciences laboratory at the University of Liege examined data from more than 500 healthy participants. The majority of the subjects were young people between 18 and 31 years old, another group included participants aged 50 to 69 years. The researchers compared the characteristics of their sleep with the polygenic risk of Alzheimer's disease, an indicator that takes into account the cumulative effect of multiple genetic variants on the likelihood of developing the disease. The results are published in Science Daily.

The analysis showed a link between genetic risk and the number of micro-arousals during sleep in the participants of the older group. We are talking about short bursts of brain activity that can briefly disrupt the normal sleep cycle, but a person does not necessarily wake up completely and may not even remember them in the morning. The researchers did not find such a connection among the young participants.

At the same time, scientists emphasize that the discovered connection does not mean that frequent micro-arousals predict the development of the disease in a particular person. The study shows a statistical association between sleep patterns and genetic risk, rather than proving a cause-and-effect relationship. In addition, the genetic risk indicator itself does not allow us to determine whether a particular person will get sick in the future.

Malfunction in the right cells: scientists have found the early mechanism of Alzheimer's disease

A small area of the brain that attracted the attention of scientists

The researchers also examined the blue spot (locus coeruleus), a small area of the brain stem about the size of a grain of rice. It is involved in the regulation of wakefulness, attention, and sleep. Scientists consider this area to be particularly interesting in the context of Alzheimer's disease, as it is one of the areas of the brain where abnormal protein deposits can appear in the early stages of the disease.

A team from the University of Liege had previously studied the blue spot using an MRI scan with a 7 tesla magnetic field. Work carried out in 2025 showed a link between sleep characteristics and the state of this area of the brain at a young age. In addition, the normal functioning of the blue spot was associated with the quality of REM sleep, which plays an important role in memory processes.

According to researcher Gilles Vandeval, the blue spot is difficult to study, but it is likely involved in early disease-related mechanisms.

At the same time, scientists cannot yet say that it is sleep disorders that trigger pathological processes or, conversely, are their early consequence. More research is needed to understand the nature of this relationship.

Scientists have found a way to predict the development of early dementia

Sleep can be a tool for early detection of the disease.

The results suggest that sleep patterns in the future may be used together with other methods to find people who are potentially more vulnerable to Alzheimer's disease even before the first symptoms appear. Currently, the diagnosis of the disease is largely focused on cognitive changes that have already occurred, so the ability to detect disease-related processes earlier is of great interest to researchers.

Scientists also want to find out whether improved sleep can influence the further development of the disease in people with a genetic predisposition. If this connection is confirmed, sleep may potentially turn out to be not only an indicator of the state of the brain, but also one of the directions of prevention.

However, the practical application of the results is still far away. The authors emphasize that the current work has revealed a statistical relationship, but has not proven that a certain type of sleep causes Alzheimer's disease or reliably predicts it in a particular person. This will require further research and long-term follow-up of the participants. Nevertheless, the work provides scientists with another possible guideline for studying early changes occurring in the brain long before a person notices memory problems or other characteristic signs of the disease.