Sleep disturbances, especially sleep duration, sleep fragmentation and sleep-disordered breathing may play a role in the development of cognitive impairment in older adults, according to study results published in The Lancet Neurology.
An increased prevalence of sleep disturbances in people with dementia has been well documented, but researchers are now focusing on the possibility that sleep disturbances can also increase the risk of cognitive decline and dementia.
Researchers conducted observational studies on the risk of cognitive decline and dementia associated with insomnia, sleep quality, sleep duration, excessive daytime sleepiness, sleep-disordered breathing, and circadian rhythm disturbances.
Results for insomnia and circadian rhythm dysfunction showed inconsistent evidence, with only some studies finding a link to cognitive impairment.
Studies on sleep quality, sleep duration, excessive daytime sleepiness and sleep-disordered breathing all suggest links between these sleep disturbances and worse cognitive outcomes.
Researchers hypothesize that several mechanisms could underlie the link between poor sleep quality and cognitive impairment. Further studies that use structural MRI and biomarkers are needed to discern which of these underlying mechanisms are affecting cognitive function.
These findings suggest that the sleep-wake cycle plays an important part in brain aging, which could suggest a potential path for cognitive improvement for people at risk for cognitive decline.
Sleep disturbances and cognitive impairment are common in older adults. Mounting evidence points to a potential connection between sleep and cognitive function. Findings from observational studies support a role for sleep disturbances (particularly for sleep duration, sleep fragmentation, and sleep-disordered breathing) in the development of cognitive impairment.