Relationships among disordered sleep and cognitive and functional status in nursing home residents.

This descriptive study examined relationships among disordered sleep and cognitive and functional status in nursing home residents (N = 90). Baseline data were used from a randomized controlled clinical trial that took place in three nursing homes. The sample included individuals age 55 and older with disordered sleep and cognitive impairment. We measured nighttime sleep with attended polysomnography and cognitive status with the Mini-Mental State Examination and assessed two indicators of functional status: level of assistance required and gait speed. Decreased total sleep time (TST), fewer respiratory awakenings, and higher oxygen saturation (SaO(2)) nadir were associated with better cognitive and functional status. After controlling for the effect of cognitive status, the association between decreased TST and better gait speed remained significant. Although correlation does not establish causation, these findings suggest that interventions to decrease nighttime respiratory awakenings and maintain SaO(2) have the potential to support cognitive and functional status in nursing home residents.