New research from Edith Cowan University (ECU) indicates that sleep patterns and genetic differences may interact to influence early brain changes linked to Alzheimer’s disease—years before noticeable symptoms appear.
Researchers at ECU’s Centre for Precision Health (CPH) studied variations in the aquaporin-4 (AQP4) gene, which helps regulate fluid movement in the brain. This process supports the brain’s natural waste-clearance system and may play a role in removing proteins associated with Alzheimer’s disease.
How Sleep Supports the Brain’s Waste-Clearance System
The brain’s waste-removal process becomes more active during sleep. Scientists believe this overnight system helps clear potentially harmful substances, including proteins linked to Alzheimer’s disease and other forms of cognitive decline.
The ECU study found that the relationship between sleep and brain health may differ according to the specific AQP4 gene variant a person carries.
“Our study shows that individuals carrying certain AQP4 variants showed faster grey matter loss when they reported shorter sleep,” researcher Dr. Ayeisha Milligan Armstrong said.
“It’s not just which genes you carry—it’s how those genes interact with the world around you. The same variant can look protective or detrimental depending on how someone is sleeping. That’s important, because sleep is one of the few modifiable factors people can actually act on.”
Grey matter contains many of the brain cells responsible for memory, decision-making, movement, and other essential functions. A reduction in grey matter volume may indicate structural brain changes associated with aging and neurological disease.
Sleep and Brain Changes Varied by AQP4 Gene Variant
The researchers analyzed 13 common AQP4 gene variants alongside participants’ self-reported sleep habits, brain scans, and cognitive test results.
For some participants, sleeping fewer hours was associated with a faster reduction in grey matter. For others, taking longer to fall asleep was linked to structural brain changes and lower brain volume.
Cognitive performance also changed differently over time among participants who experienced sleep disturbances. Whether sleep appeared to have a beneficial or harmful association depended on the specific AQP4 variant each person carried.
“We’ve known for a while that poor sleep and Alzheimer’s risk are linked,” researcher Dr. Tenielle Porter said.
“What this shows is that rather than assuming everyone at risk follows the same pathway, a more targeted and personalized approach to Alzheimer’s prevention may be needed. But we’re not at the point of recommending genetic testing; our findings need replication in larger and more diverse cohorts.”
Could Genetics Support Personalized Alzheimer’s Prevention?
The findings suggest that people with similar overall Alzheimer’s disease risk may not experience the same effects from poor sleep. Genetic differences could help explain why brain changes progress more quickly in some individuals than in others.
The researchers say future clinical trials should include genetic information. These studies could determine whether improving sleep quality and duration can reduce inherited vulnerability and influence long-term brain health outcomes linked to Alzheimer’s disease.
“This moves us closer to understanding why some people decline faster than others, even when they have similar risk on paper,” CPH Director Professor Simon Laws said.
“Identifying who is most vulnerable, and who is most likely to benefit from a particular lifestyle intervention, is where precision health needs to go rather than treating everyone at risk of Alzheimer’s the same way.”
The study, “Evidence for Direct and Sleep-Moderated Relationships between Aquaporin-4 Genetic Variants and Alzheimer’s Disease Phenotypes,” is published online in Alzheimer’s & Dementia, the Journal of the Alzheimer’s Association.
Source: www.sciencedaily.com