The relation between cognitive functioning and self-reported sleep complaints in nondemented older adults: results from the Bronx aging study.

Self-reported sleep complaints and current cognitive functioning were assessed in 375 nondemented participants ages 75 to 85 years (134 men and 241 women) as part of enrollment in the Bronx aging study, an ongoing longitudinal community-based study of cognitive aging. This study only reports on the baseline data collected from 1980 to 1983. Sleep complaints were common, occurring in about 25% of the sample. Furthermore, after controlling for depression, use of hypnotic medication, physical morbidity, age, and education, participants who reported longer sleep onset latencies performed significantly worse on measures of verbal knowledge, long-term memory and fund of information, and visuospatial reasoning. Participants who reported longer sleep durations did significantly worse on a measure of verbal short-term memory. These results suggest that perceived sleep is related to select objective cognitive abilities even when accounting for commonly recognized mediating variables, such as depression, medical comorbidity, age, or use of hypnotic medication. Given the restricted range of this nondemented sample, these results may underestimate the relation between cognitive abilities and sleep.