Sleep Duration and Dementia Risk in Older Adults

A recent study authored by Ying Xiong, PhD Student, and colleagues examined the link between sleep patterns and dementia in older adults (aged ≥65 years) using data from the English Longitudinal Study of Ageing. Among 7,223 participants, 5.7% developed dementia, with 1.7% developing Alzheimer’s disease (AD) over an average of 8 years. The study team found an association between long sleep duration (>8 h) with a 64% increased risk of dementia and a 2-fold higher risk of AD when compared with patients who had ideal sleep duration (7–8 h). This association was more pronounced in older adults (≥70 years) and those who consumed alcohol. Conversely, short sleep duration (<7 h) was associated with a lower risk of dementia in older adults but a higher risk in younger adults. Sleep disturbances and perceived sleep quality were not linked to dementia or AD. Mendelian randomization analysis did not reveal a causal relationship between sleep duration and dementia. These findings suggest that self-reported short sleep patterns in younger adults and long sleep patterns in older adults, particularly those who consume alcohol, are associated with dementia.