Dynamics of Sleep Fragmentation in the Elderly

老年人睡眠碎片化的动态

• 批准号: 7530065
• 负责人: EUGENE N BRUCE
• 金额: $ 5.91万
• 依托单位: UNIVERSITY OF KENTUCKY
• 依托单位国家: 美国
• 财政年份: 2008
• 资助国家: 美国
• 起止时间: 2008-08-01 至 2010-06-30
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/7530065
• 关键词: Accounting; Address; Adult; African American; Age; Aging; Applications Grants; Arousal; Categories; Caucasians; Caucasoid Race; Circadian Rhythms; Clinical; Complex; Data; Data Analyses; Depth; Development; Disruption; Distant; Elderly; Electroencephalogram; Entropy; Evaluation; Event; Figs - dietary; Foundations; Frequencies; Future; Gender; Goals; Health; Heart; Homeostasis; Incidence; Individual; Kale - dietary; Life; Measures; Methods; Modeling; Nature; Neurocognitive; Numbers; Pattern; Play; Predisposition; Prevalence; Public Health; Race; Rate; Relative (related person); Reporting; Research Project Grants; Resolution; Role; Sampling; Signal Transduction; Sleep; Sleep Fragmentations; Sleep disturbances; Slow-Wave Sleep; Staging; Standards of Weights and Measures; Stimulus; Structure; Testing; Time; Variant; Woman; age effect; age related; base; clinically significant; concept; experience; indexing; insight; men; middle age; neuromechanism; novel; relating to nervous system; sleep regulation; time use

DESCRIPTION (provided by applicant): Aging is associated with major changes in the structure and quality of sleep. Older subjects experience decreased sleep efficiency, increased numbers of arousals and awakenings, and sleep fragmentation, which may well play a pivotal role in both the daytime sleepiness and the age-associated decline in neurocognitive function in the elderly. This application develops and tests an integrative hypothesis that relates arousals to the occurrence of transient EEG events indicative of subthreshold arousals and sleep consolidations. By applying this integrative framework to both middle-aged (40-49 yrs) and elderly (70-79 yrs) Caucasian and African-American men and women, we expect to generate novel insights into the causes of sleep fragmentation in the elderly. Preliminary results show that Sample Entropy of the C3A2 EEG signal varies systematically with sleep state, being highest in Wake and lowest in stage 3-4, and that this variation is age-dependent. Thus, a conceptual model of temporal fluctuations of depth of sleep within a sleep state and a novel measure of depth of sleep, EEG entropy (a measure of irregularity), are proposed. A core principle of the model is that depth of sleep is continuously graded. Three hypotheses derived from this model will be tested: (1) EEG entropy fluctuates in a given sleep state and arousals are more likely when entropy transiently increases; (2) in a given sleep state, fluctuations of EEG entropy with time (which reflect short-lived events in the EEG such as microarousals and bursts of delta waves) are not entirely random; rather, they also reflect the slow decay of the effects of prior events that perturbed the depth of sleep; and, (3) the time course of decay of the effects of past sleep-disturbing events is slower in elderly than in middle- aged subjects; this factor contributes to the increased number of arousals in the elderly by prolonging the period of increased susceptibility to a subsequent sleep disturbance. This Small Research Grant will utilize existing data from the NHLBI-supported Sleep Heart Health Study (polysomnograms from >6400 subjects are available). PUBLIC HEALTH RELEVANCE: We expect that the proposed studies will develop and validate a novel framework for understanding the time-varying relationship of transient EEG events to arousals and their increase with aging. Additionally, Sample Entropy of EEG signals may find utility as a measure of depth of sleep for evaluating the effects of therapies. The goal of this study is to understand why the elderly awaken more frequently at night than younger individuals. To accomplish this objective, we will analyze electroencephalogram (EEG) recordings obtained from middle-aged and elderly subjects while they are asleep to enhance our understanding of the changes that occur in these EEGs immediately before subjects wake up.

描述（由申请人提供）：衰老与睡眠结构和质量的重大变化有关。老年受试者的睡眠效率下降、觉醒和觉醒次数增加以及睡眠碎片化，这很可能在老年人日间嗜睡和与年龄相关的神经认知功能下降中发挥着关键作用。该应用程序开发并测试了一个综合假设，该假设将唤醒与指示阈下唤醒和睡眠巩固的瞬时脑电图事件的发生联系起来。通过将这一综合框架应用于中年（40-49 岁）和老年人（70-79 岁）白人和非裔美国男性和女性，我们期望对老年人睡眠碎片化的原因产生新的见解。初步结果表明，C3A2 EEG 信号的样本熵随睡眠状态而系统地变化，在清醒时最高，在 3-4 阶段最低，并且这种变化与年龄相关。因此，提出了一种睡眠状态内睡眠深度时间波动的概念模型和一种新的睡眠深度测量方法——脑电图熵（不规则性的测量方法）。该模型的核心原则是睡眠深度是连续分级的。将测试从该模型得出的三个假设：（1）脑电图熵在给定的睡眠状态下波动，并且当熵短暂增加时更有可能被唤醒； （2）在给定的睡眠状态下，脑电图熵随时间的波动（反映脑电图中的短暂事件，例如微唤醒和δ波爆发）并不完全随机；相反，它们还反映了先前扰乱睡眠深度的事件的影响的缓慢衰减； (3)老年人过去睡眠干扰事件影响的衰减时间进程比中年受试者慢；该因素延长了对随后的睡眠障碍的易感性增加的时间，从而导致老年人觉醒次数的增加。这笔小额研究补助金将利用 NHLBI 支持的睡眠心脏健康研究的现有数据（来自超过 6400 名受试者的多导睡眠图）。 公共健康相关性：我们期望拟议的研究将开发和验证一个新的框架，用于理解短暂脑电图事件与觉醒及其随年龄增长而增加的时变关系。此外，脑电图信号的样本熵可以作为睡眠深度的衡量标准，以评估治疗效果。这项研究的目的是了解为什么老年人比年轻人更容易在夜间醒来。为了实现这一目标，我们将分析中老年受试者在睡眠时获得的脑电图（EEG）记录，以增强我们对受试者醒来前脑电图发生的变化的理解。