Disrupted Sleep, Neuroendocrine Status and the Behavioral Symptoms of AD

Alzheimer's Disease

Over 5 million Americans have Alzheimer's disease or a related dementia, a progressive and irreversible neurodegenerative condition, affecting also close to 15 million family caregivers (CG). Sleep efficiency in AD patients is severely impaired and complicated by frequent night awakenings and nocturnal restlessness. Untreated sleep disruption in AD patients is associated with increased rates of neuropsychiatric symptoms, daytime napping, 'sundowning' behaviors, cognitive and functional decline, and morbidity and mortality. The added strain of sleep disruption is the primary reason family caregivers make the decision to institutionalize AD patients. The circadian abnormalities in the sleep-wake cycle commonly observed in AD patients occur more often in individuals with hypothalamic/ pituitary/adrenal (HPA) axis hyperactivity. HPA axis hyperactivity may influence diurnal sleep-wake activity by diminishing an AD patient's ability to respond to external zeitgebers which, in turn, can further propagate HPA axis dysfunction. Thus, interventions to normalize diurnal HPA axis patterns may be beneficial in treating sleep-wake disturbances. Nonpharmacologic treatments are the first line therapy in AD patients with sleep wake problems, given the ineffective and potentially harmful effects of pharmacologic agents. Current clinical sleep hygiene practices in institutional (e.g., nursing home) settings holds promise for reducing disruptive sleep by reestablishing circadian patterns in HPA functioning. These interventions include use of timed and planned activities during daylight hours and creating a relaxing environment in the evening. However little systematic work has been done to determine the efficacy of these interventions in the home setting (where most individuals with AD reside). We propose a pilot study to (a) characterize objective sleep parameters and behavioral symptoms of sleep-wake disturbance, and biological indicators of diurnal HPA axis activity in a sample of community residing older adults with AD: (b) examine the effects of timed and planned activities on subjective and objective characteristics of sleep, behavioral symptoms, and HPA status; and (c) evaluate measurement approaches in home-dwelling AD patients. Subjective (CG questionnaires) and objective (wrist actigraphy) characteristics of sleep and behavioral symptoms will be measured in fifty-four AD patients being cared for at home by a family. Patients and CG with then be randomized to receive an intervention of timed, planned activities (TPA) or attention control (AC) condition. We will also obtain diurnal measures of HPA activity including salivary cortisol and alpha amylase.

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