PHASE SHIFT TOLERANCE IN OLDER PEOPLE

老年人的相移耐受性

基本信息

批准号：
6627924
负责人：
Timothy H. Monk
金额：
$ 24.33万
依托单位：
UNIVERSITY OF PITTSBURGH AT PITTSBURGH
依托单位国家：
美国
项目类别：
财政年份：
1996
资助国家：
美国
起止时间：
1996-02-10 至 2006-01-31
项目状态：
已结题

项目摘要

The sleep problems of older men and women often have timing difficulties as a significant part of their etiology. A misalignment of the circadian system ("biological clock") of older people by only a few hours can lead to significant sleep impairment. Thus, an examination of the effects of shifts in the timing of sleep may lead to therapeutic strategies which could alleviate the sleep disorders of older people without resorting to hypnotic medications. In our previous work we have studied the tolerance of elderly people to phase shifts of 6h. We now propose to investigate rather smaller (2h) phase shifts. We shall compare three groups: older men, older women, and young controls, in their response to both phase delays and phase advances, with all subjects doing control, advance and delay conditions. We also plan to investigate the relationship between circadian rhythms and sleep by indexing the bedtime (control or shifted) to its phase difference from the phase of the endogenous circadian pacemaker. We shall use two well accepted circadian phase markers: 1) the time of minimum [Tmin] of the rectal temperature rhythm as fitted by 24h and 12h sinusoids, and 2) the timing of Dim Light Melatonin Onset (DLMO) as measured by half-hourly evening salivary samples. Each subject will experience three conditions in three separate 120h runs. In each run, after two baseline days and nights (48h) at the subject's habitual routine, subjects will live for 3 days and nights under ad-lib sleep length (time in bed) conditions, but with the timing of bedtime specified. First, in the control condition, the bedtime will always be at habitual bedtime, so that baseline levels of sleep and daytime performance can be obtained and the phase difference between Tmin and bedtime, and between DLMO and bedtime later calculated from the entire 5-day run. In the advance condition the bedtime on nights 3-5 will be two hours earlier than habitual bedtime. In the delay condition bedtime on nights 3-5 will be two hours later than habitual bedtime. In all cases, sleeps will be polysomnographically recorded, rectal temperatures monitored continuously, and daytime alertness, mood and performance assessed using our usual battery of tests. We propose to study 10 older (70y+) women, 10 older (70y+) men and 10 young (20y - 35y) controls (5m, 5f), with order of presentation of the advance and delay conditions counterbalanced. Hypotheses will be tested relating both to the effect of phase shift on nocturnal sleep and daytime alertness and performance variables, and also to the effect on these variables of individual daily variations in observed circadian phase angle between Tmin and bedtime, and between DLMO and bedtime.

老年男人和女人的睡眠问题通常会遇到时机困难，这是其病因的重要组成部分。老年人的昼夜节律系统（“生物钟”）仅几个小时就会导致严重的睡眠障碍。因此，检查转变对睡眠时间的影响可能会导致治疗策略，这可以减轻老年人的睡眠障碍而无需诉诸催眠药物。在我们以前的工作中，我们研究了老年人对6小时相位转移的容忍度。现在，我们建议研究相当较小的（2H）相迁移。我们将比较三组：老年男性，老年女性和年轻对照，以对相位延迟和阶段进步的反应以及所有受试者进行控制，进步和延迟条件。我们还计划通过将就寝时间（控制或移动）与内源性昼夜节律起搏器相位索引（控制或移动）来研究昼夜节律和睡眠之间的关系。我们将使用两个公认的昼夜节律标记：1）由24小时和12H正弦曲线拟合的直肠温度节奏的最小[Tmin]时间，以及2）昏暗的光褪黑激发（DLMO）的时机，如半小时的晚间唾液样品测量。每个受试者将在三个单独的120h运行中经历三个条件。在每次跑步中，在受试者习惯的两个基准日和晚上（48h）之后，受试者将在Ad-Lib睡眠长度（床上的时间）状态下生活3天和晚上，但指定了就寝时间的时间。首先，在控制条件下，就寝时间将始终处于惯常的就寝时间，因此可以获得基线的睡眠和白天表现，以及TMIN和就寝时间之间的相位差异，DLMO和Batige之间的相差后来从整个5天运行中计算出来。在预先条件下，晚上3-5的睡前时间比习惯性就寝时间早两个小时。在延迟状态下，晚上3-5的睡前时间要比习惯睡前晚两个小时。在所有情况下，睡眠都会记录在多个图中，直肠温度连续监测，以及使用我们通常的测试电池进行评估的白天警报，情绪和表现。我们建议研究10名年龄较大（70岁+）的女性，10名年龄较大（70y+）男性和10名Young（20y -35y）对照（5M，5F），并呈现前进和延迟条件的顺序。假设将进行测试，既将相对于夜间睡眠的影响以及白天的警觉性和性能变量的影响，以及对观察到的昼夜节律变化的影响TMIN和BEDTIME之间的昼夜节相角以及DLMO和BEDTIME之间的影响。