Dyadic Sleep, Biobehavioral Rhythms and Cognitive Function in Older Adults: Implications for Alzheimer’s Disease

摘要 轻度认知障碍（MCI）患者表现出认知功能下降， 而且患阿尔茨海默病的风险增加了7倍，阿尔茨海默病是 生活质量（QOL）较差，过早死亡和医疗保健支出。睡眠和生物行为节律 干扰（生理和行为的24小时振荡中断，包括休息-活动模式， 在MCI患者中，与认知功能正常的老年人相比，进食时间）是其两倍多。 新出现的证据表明，睡眠和生物行为节律紊乱的机制作用， 认知能力下降和阿尔茨海默病的发展和进展。重要的是，后果 MCI患者的睡眠和生物行为节律中断的影响超出了患者的范围，也影响了 配偶/伴侣，因为睡眠是大多数成年人的“共享”健康行为。然而，睡眠和生物行为 节奏通常被认为是在个人的水平。基于我们团队在睡眠方面的开创性工作， 作为夫妻之间的共同经历，我们建议调查睡眠和生物行为节律， 有助于MCI患者健康和认知功能的基本二元过程，或 轻度AD及其伴侣。我们将评估睡眠中两个二元过程的日常和纵向影响： 相互依赖性（伴侣的睡眠模式相互影响）和一致性（即，这对夫妇的 休息/活动和社交节奏（如进餐时间）的相似性）。我们将进行为期14天的自然主义研究 为了检查睡眠和生物行为节律之间的机械关联， 近端指标的白天功能，在170对夫妇的样本中，其中一方的证据 认知障碍（MCI至轻度阿尔茨海默病）。在自然主义研究方案中，我们将捕捉 通过睡眠和昼夜休息-活动的客观（活动记录）测量睡眠和生物行为节律 节奏和日常社会节奏。此外，我们还将包括每日情绪评估， 关系质量，我们将使用创新的智能手机认知评估，已被验证， 测量日常生活中的认知功能。此外，我们将进行全面的神经心理学检查， 在基线和两年随访时再次进行评估，以检查睡眠和生物行为节律 基线干扰预测两个伴侣在2年内认知能力下降。研究结果将推动 理解个人和夫妻水平过程之间的日常和纵向关系， 影响人群认知能力下降进展的睡眠和生物行为节律增加 患阿尔茨海默病的风险。

Abstract Individuals with mild cognitive impairment (MCI) demonstrate cognitive decline without major functional impairment but also experience a 7-fold increased risk for developing Alzheimer’s disease, a leading cause of poorer quality of life (QOL), premature mortality, and health care expenditures. Sleep and biobehavioral rhythm disturbances (disruptions in 24h oscillations in physiology and behavior, including rest-activity patterns and mealtimes) are more than twice as common among patients with MCI than cognitively intact older adults. Emerging evidence demonstrates a mechanistic role of sleep and biobehavioral rhythm disturbances in cognitive decline and the development and progression of Alzheimer’s disease. Importantly, the consequences of sleep and biobehavioral rhythm disruption in MCI extend beyond the patient, also affecting the spouse/partner, as sleep is a “shared” health behavior for most adults. However, sleep and biobehavioral rhythms are typically considered at the level of the individual. Building on our team’s pioneering work on sleep as a shared experience among couples, we propose to investigate sleep and biobehavioral rhythms as fundamental dyadic processes that contribute to the health and cognitive functioning of individuals with MCI or mild AD and their partners. We will evaluate the daily and longitudinal effects of two dyadic processes in sleep: interdependence (partners’ sleep patterns influence on each other) and concordance (i.e., the couples’ similarity in rest/activity and social rhythms such as meal timing). We will conduct a 14-day naturalistic study protocol in order to examine the mechanistic associations between sleep and biobehavioral rhythms and proximal indicators of daytime functioning, within a sample of 170 couples in which one partner evidences cognitive impairment (MCI to mild Alzheimer’s disease). During the naturalistic study protocol, we will capture sleep and biobehavioral rhythms via objective (actigraphy) measures of sleep and circadian rest-activity rhythms and daily social rhythms, respectively. Also, we will include daily assessments of mood and relationship quality, and we will use an innovative smartphone cognitive assessment that has been validated to measure cognitive function in daily life. In addition, we will conduct comprehensive neuropsychological assessments at baseline and again at two-year follow-up to examine how sleep and biobehavioral rhythm disruptions at baseline predict cognitive decline over 2 years in both partners. Results of study will advance the understanding of the daily and longitudinal relationships between the individual and couple-level processes in sleep and biobehavioral rhythms that influence the progression of cognitive decline in a population at increased risk for developing Alzheimer’s disease.