Impact of Disturbed Rest-activity Rhythms on Activities of Daily Living in Moderate and Severe Dementia Patients

Purpose: People with dementia exhibit disturbed rest-activity rhythms and extended sleep duration issues throughout their disease. Little is known about the effects of these issues on clinical problems for those with moderate and severe dementia. This cross-sectional study aimed to examine the associations of disturbed rest-activity rhythms and extended sleep duration with activities of daily living (ADL). Methods: Sleep parameters were measured using an actigraphy device. Cognitive function was assessed using the Mini-Mental State Examination and Cognitive Test for Severe Dementia, the Hyogo Activities of Daily Living Scale was used to assess ADL, and behavioral and psychological symptoms of dementia were assessed using the Neuropsychiatric Inventory-Nursing Home scale. Associations among rest-activity rhythms, sleep duration, and other clinical variables were analyzed with multiple linear regression. Clinical variables were compared between 2 groups categorized by onset timing of rest peak. Patients: Sixty-four participants with moderate and severe dementia were assessed. Results: In the correlation analysis, unstable daily rest-activity rhythm was associated with lower ADL. In the multiple linear regression analysis, low intradaily variability, and long daytime sleep duration were associated with low ADL. Aberrant rest peak timing showed lower ADL compared with nonaberrant timing. Conclusions: Abnormal rest-activity rhythm and sleep duration in persons with moderate and severe dementia may affect ADL.