Self reported sleep duration and cognitive performance in older adults: a systematic review and meta analysis.
Sleep is important for optimal cognitive functioning across the lifespan. Among older adults =55 years) self reported short and long sleep durations have been repeatedly, albeit inconsistently, reported to elevate the risk for poor cognitive function. This meta analytic review quantitatively summarizes the risk for poorer cognitive function among short and long sleepers in older adults. Eligible publications were searched online and manually. A total of 35 independent samples (N 97,264) from 11 cross sectional and seven prospective cohort studies were included. Pooled odds ratios (OR) with 95% confidence intervals (CI) were derived using random effects models. Self reported short and long sleep increased the odds for poor cognitive function by 1.40 (CI 1.27 1.56) and 1.58 times (CI 1.43 1.74) respectively. Effect sizes varied across studies and may have been moderated by both study type (cross sectional and prospective) and cognitive domain assessed. For cross sectional studies, extreme sleep durations were significantly associated with poorer multiple domain performance, executive functions, verbal memory, and working memory capacity. Prospective cohort studies revealed the significant long term impact of short and long sleep on multiple domain performance only. These findings establish self reported extreme sleep duration as a risk factor for cognitive aging.
Sleep medicine