Sleep and physical functioning in family caregivers of older adults with memory impairment

Sleep disturbance is common in caregivers of older adults with memory disorders. Little is known, however, about the implications of caregivers' poor sleep with regard to their physical functioning.

In this cross-sectional study, we investigated the association between objectively measured sleep and self-reported physical functioning in 45 caregivers (mean age = 68.6 years) who completed the Beck Depression Inventory-II, the Medical Outcomes Study SF-36, and the Mini-mental State Examination, and wore an actigraph for at least three days. Our primary predictors were actigraphic sleep parameters, and our outcome was the SF-36 Physical Functioning subscale.

In multivariate-adjusted linear regression analyses, each 30-minute increase in caregivers' total sleep time was associated with a 2.2-point improvement in their Physical Functioning subscale scores (unstandardized regression coefficient (B) = 2.2, 95% confidence interval (CI) 1.0-3.4, p = 0.001). In addition, each 10-minute increase in time awake after initial sleep onset was associated with a 0.5-point decrease on the Physical Functioning subscale, although this was not statistically significant (B = -0.5, 95% CI -1.1, 0.1, p = 0.09).

Our findings suggest that shorter sleep duration is associated with worse self-reported physical functioning in caregivers. Longitudinal studies are needed to determine whether poor sleep predicts functional decline in caregivers.