Sleep movements and respiratory coupling as a biobehavioral metric for early Alzheimer’s disease in independently dwelling adults

Abstract

Introduction Sleep disorder is often the first symptom of age-related cognitive decline associated with Alzheimer’s disease (AD) observed in primary care. The relationship between sleep and early AD was examined using a patented sleep mattress designed to record respiration and high frequency movement arousals. A machine learning algorithm was developed to classify sleep features associated with early AD. Method Community-dwelling older adults (N = 95; 62–90 years) were recruited in a 3-h catchment area. Study participants were tested on the mattress device in the home bed for 2 days, wore a wrist actigraph for 7 days, and provided sleep diary and sleep disorder self-reports during the 1-week study period. Neurocognitive testing was completed in the home within 30-days of the sleep study. Participant performance on executive and memory tasks, health history and demographics were reviewed by a geriatric clinical team yielding Normal Cognition (n = 45) and amnestic MCI-Consensus (n = 33) groups. A diagnosed MCI group (n = 17) was recruited from a hospital memory clinic following diagnostic series of neuroimaging biomarker assessment and cognitive criteria for AD. Results In cohort analyses, sleep fragmentation and wake after sleep onset duration predicted poorer executive function, particularly memory performance. Group analyses showed increased sleep fragmentation and total sleep time in the diagnosed MCI group compared to the Normal Cognition group. Machine learning algorithm showed that the time latency between movement arousals and coupled respiratory upregulation could be used as a classifier of diagnosed MCI vs. Normal Cognition cases. ROC diagnostics identified MCI with 87% sensitivity; 89% specificity; and 88% positive predictive value. Discussion AD sleep phenotype was detected with a novel sleep biometric, time latency, associated with the tight gap between sleep movements and respiratory coupling, which is proposed as a corollary of sleep quality/loss that affects the autonomic regulation of respiration during sleep. Diagnosed MCI was associated with sleep fragmentation and arousal intrusion.

Shifting From Active to Passive Monitoring of Alzheimer Disease: The State of the Research

“…Latency between movement arousals and coupled respiratory upregulation derived from the sleep monitoring produced >85% sensitivity and specificity. 30 As with other measures, collecting sleep data at home provides opportunities for additional evaluation of variability and change over time at a minimal cost and engagement. At‐home passive sleep monitoring via infrared sensors has suggested that tracking sleep through movement and sleep time could be an effective method for detecting dementia.…”

Friends and Foes in Alzheimer’s Disease

“…Changes in mood, disturbed sleep patterns, and memory loss are among the earliest symptoms of AD. Although AD primarily affects the brain, during the course of the disease, extracranial body systems can be affected, including the respiratory system [ 61 ], digestive system [ 62 ], and urinary system [ 63 ] as well as changes in the epidermal layer of the skin [ 64 ]. Considering these and other organ-related symptoms, AD is increasingly being recognized as a multi-organ disorder [ 65 ].…”