Assessment of sleep satisfaction in patients with dementia due to Alzheimer's disease.

Sleep length and architecture are potential markers of progressive cognitive impairment, while neuropsychiatric symptoms and APOE4- haplotypes have been associated with more sleep complaints in patients with dementia due to Alzheimer's disease (AD). In this cross-sectional study, we sought to investigate which factors might be related to sleep satisfaction in patients with AD. A total of 217 consecutive patients with AD were assessed for demographic features, neuropsychiatric symptoms, cognitive decline, functional impairment for activities of daily living, caregiver burden, APOE haplotypes, self-reported sleep satisfaction and length of sleep. Statistical comparisons were conducted with significance at p<0.05. Concerning sleep complaints, 179 patients (82.5%) reported satisfactory sleep, while 38 (17.5%) were unsatisfied, with no relation to age, sex, APOE haplotypes, obesity, education, marital status, alcohol consumption or smoking found. Length of sleep (p=0.011) and behavioural symptoms (p=0.009) had significant associations with sleep satisfaction. Length of sleep was positively correlated with apathy (p=0.014) and scores on the Clock Drawing Test (p=0.015), and inversely correlated with anxiety (p=0.015) and independence for instrumental activities of daily living (p=0.003). Patients who were treated with memantine (p=0.02) or anti-psychotics (p<0.01) had longer duration of sleep. In conclusion, behavioural symptoms had strong associations with sleep satisfaction, which is highly correlated with length of sleep in patients with AD. Functional independence, apathy, anxiety, use of memantine or anti-psychotics, and scores on the Clock Drawing Test were significantly associated with length of sleep in this sample.