by Isabella Colonna
For August we selected Anagnostakis F, O’Toole CK, Erus G, et al. Association of sleep duration with Alzheimer’s disease and cognition. Alzheimers Dement. 2026 Jul;22(7):e71528. https://doi.org/10.1002/alz.71528. PMID: 42417271; PMCID: PMC13343368.
Sleep plays a fundamental role in healthy brain aging. A growing body of evidence indicates that sleep quality influences cognitive functions, including memory and executive function, and may contribute to the risk of neurodegenerative diseases. However, despite accumulating evidence, the relationship between sleep duration, Alzheimer’s disease (AD)-related brain atrophy, and cognitive performance remains incompletely understood.
In this study, the authors analysed data of 38,816 study participants of the UK Biobank, an ongoing prospective cohort study in the United Kingdom, to investigate the association between sleep duration, a validated machine-learning-derived magnetic resonance imaging signature of AD-related atrophy, and three cognitive test scores. Additionally, electronic health record data from TriNetX network were analysed to assess the 10-year risk of AD associated with insomnia and hypersomnia.
Sleep duration showed a U-shaped association with AD-related brain atrophy as well as with cognitive performance, with both short (5–6 hours) and long (9–10 hours) sleep durations associated with poorer cognitive outcomes compared with 7–8 hours, particularly in males. Furthermore, data from TriNetX network showed that both insomnia and hypersomnia were associated with an increased risk of incident AD.
In conclusion, these findings highlight sleep as a potentially modifiable risk factor for cognitive decline, suggesting that improving sleep duration and managing sleep disorders may contribute to maintaining cognitive health and reducing dementia risk.
