Increasing walking and bright light exposure to improve sleep in community-dwelling persons with Alzheimer's disease: results of a randomized, controlled trial.

OBJECTIVES To test the effects of walking, light exposure, and a combination intervention (walking, light, and sleep education) on the sleep of persons with Alzheimer's disease (AD). DESIGN Randomized, controlled trial with blinded assessors. SETTING Independent community living. PARTICIPANTS One hundred thirty-two people with AD and their in-home caregivers. INTERVENTIONS Participants were randomly assigned to one of three active treatments (walking, light, combination treatment) or contact control and received three or six in-home visits. MEASUREMENTS Primary outcomes were participant total wake time based on wrist actigraphy and caregiver ratings of participant sleep quality on the Sleep Disorders Inventory (SDI). Secondary sleep outcomes included additional actigraphic measurements of sleep percentage, number of awakenings, and total sleep time. RESULTS Participants in walking (P=.05), light (P=.04), and combination treatment (P=.01) had significantly greater improvements in total wake time at posttest (effect size 0.51-0.63) than controls but no significant improvement on the SDI. Moderate effect size improvements in actigraphic sleep percentage were also observed in active treatment participants. There were no significant differences between the active treatment groups and no group differences for any sleep outcomes at 6 months. Participants with better adherence (4 d/wk) to walking and light exposure recommendations had significantly less total wake time (P=.006) and better sleep efficiency (P=.005) at posttest than those with poorer adherence. CONCLUSION Walking, light exposure, and their combination are potentially effective treatments for improving sleep in community-dwelling persons with AD, but consistent adherence to treatment recommendations is required.