No Association Between Sleep and Risk of Dementia

A new study examined the relationship between sleep and risk of dementia in 4700 participants with a mean age of 74 years who were followed for 5-19 years for development of dementia after their sleep was assessed on measures of insomnia (wake time after sleep onset and sleep efficiency) as well as percent of time spent in various stages of sleep from a night of home-based polysomnography. The results showed no association between sleep stages or measures of insomnia and risk of dementia. This was the largest study to investigate the association between sleep-stage measures and risk of dementia. Because the results showed no association between sleep variables and dementia, the researchers concluded that the role of poor sleep as a dementia risk factor remains poorly understood.