Sleep disturbances linked to genetic Alzheimer's risk

A new study suggests that sleep disturbances, specifically a greater number of micro-awakenings during sleep, may be an early sign of Alzheimer's disease. Researchers from the University of Liege in Belgium found that these micro-awakenings occur in late-middle-aged adults (average age of 59) and are linked to a greater genetic risk for developing Alzheimer's, even before memory problems appear.

The study, published in the journal Sleep, tracked the sleep of over 500 healthy individuals using brain recordings to monitor micro-awakenings, which are brief periods of brain activity that do not fully awaken the person but disrupt sleep. These awakenings were compared to each person's genetically determined risk score for Alzheimer's disease.

The results showed that more frequent micro-awakenings among late-middle-aged adults were associated with greater odds of developing Alzheimer's disease, a link not observed among younger adults.

Researchers suspect that these awakenings could be linked to the locus coeruleus, a small region in the brainstem involved in wakefulness, attention, and sleep regulation. This region is one of the first areas where abnormal protein deposits linked to Alzheimer's start to appear, sometimes as early as a person's teens. The locus coeruleus is also closely associated with sleep quality.

While the study found an association between sleep problems and Alzheimer's risk, it does not establish a direct cause-and-effect link. Further research is needed to fully understand the connection between sleep disturbances and Alzheimer's disease. The study's senior researcher, Gilles Vandewalle, emphasized that sleep could become an accessible marker for early identification of vulnerable individuals. However, the team stressed that more study is needed to confirm the findings.