Respiratory Peridocity and Cognitive Decline in Elders

老年人的呼吸频率和认知能力下降

• 批准号: 6838705
• 负责人: BARBARA WAAG CARLSON
• 金额: $ 33.25万
• 依托单位: UNIV OF NORTH CAROLINA CHAPEL HILL
• 依托单位国家: 美国
• 财政年份: 2002
• 资助国家: 美国
• 起止时间: 2002-04-01 至 2006-12-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/6838705
• 关键词: African American; apnea; attention; behavioral /social science research tag; biological clocks; caucasian American; cerebrum; clinical research; cognition; dementia; gender difference; human old age (65+); human subject; longitudinal human study; mental health epidemiology; oximetry; oxygen transport; plethysmography; polysomnography; psychological aspect of aging; racial /ethnic difference; respiratory oxygenation; respiratory reflex; short term memory; sleep

Laboratory and clinical findings suggest that states of low cerebral oxygenation are associated with cognitive decline and dementia in older adults. Sleep is a period of increased risk for hypoxic events; and low respiratory periodicity may be an important indicator for identifying individuals with low cerebral oxygenation during sleep. Our previous studies suggest that older adults with low respiratory periodicity have more fragmented sleep, more low amplitude delta sleep and greater declines in cerebral oxygenation during sleep. The aims of this longitudinal observational study are (1) to examine the relationship between measures of respiratory periodicity, sleep structure and cerebral oxygenation during sleep; (2) to examine whether respiratory periodicity or cerebral oxygenation during sleep, alone or in combination, predict cognitive decline over 24 months; and (3) to explore how changes in respiratory periodicity and cerebral oxygenation change over 24 months. One hundred and six community dwelling older adults, age 70+ years, will be evaluated at baseline and at 12-and 24-months. Respiratory periodicity will be measured from the respiratory inductance plethysmograph waveform and include the average 5- minute measures of the variability in the duration (sdIBI), frequency (sdIBF) and amplitude (sdAMP) of breathing cycles. Standard polysomnographic methods will be used to measure sleep structure, which include the proportion of sleep states, as well as the mean interval between sleep spindles, sleep-wake transitions, arousals, and K-complexes. Dual (right- left) cerebral oximetry will be used to measure maximum change in the average 5-minute right and left cerebral oxyhemoglobin saturation from resting awake baseline. Standardized tests of secondary memory, working memory, and attention will be measured at the same time as the sleep studies in order to describe changes in cognitive function and to examine whether respiratory periodicity or cerebral oxygenation alone or in combination predict cognitive decline over 24 months. In addition, we will explore how respiratory periodicity and cerebral oxygenation change and interact over time. Data on sleep quality, cerebrovascular risk factors, physical activity and depressive symptoms will be measured every 6 months because these measures can change rapidly and may affect the key outcome measures. In addition to serving as a comparison group, data from subjects who do not exhibit cognitive decline will be used in exploratory analyses to determine gender and race-associated differences in respiratory periodicity and cerebral oxygenation. Since little is known about respiratory periodicity or cerebral oxygenation using cerebral oximetry in older adults, this prospective study will provide important data for determining how these variables vary and may be used to predict cognitive decline in a carefully screened sample of older adults.

实验室和临床研究结果表明，低脑氧合状态与老年人认知能力下降和痴呆有关。睡眠是缺氧事件风险增加的时期；低呼吸周期可能是识别睡眠中脑氧合低个体的重要指标。我们之前的研究表明，呼吸周期较低的老年人有更多的碎片化睡眠，更多的低振幅三角洲睡眠，睡眠时大脑氧合下降更大。本纵向观察研究的目的是：(1)研究睡眠期间呼吸周期、睡眠结构和脑氧合之间的关系；(2)检查睡眠期间的呼吸周期或脑氧合是否单独或联合预测24个月以上的认知能力下降；(3)探讨24个月呼吸周期及脑氧合变化情况。106名70岁以上的社区老年人将在基线和12个月和24个月时进行评估。呼吸周期将从呼吸感应脉搏波波形测量，包括呼吸周期持续时间（sdIBI）、频率（sdIBF）和幅度（sdAMP）的平均5分钟变异性测量。标准的多导睡眠图方法将用于测量睡眠结构，包括睡眠状态的比例，以及睡眠纺锤波、睡眠-觉醒转换、觉醒和k复合体之间的平均间隔。双（左右）脑血氧仪将用于测量从静止清醒基线开始的平均5分钟左右脑氧血红蛋白饱和度的最大变化。二级记忆、工作记忆和注意力的标准化测试将在睡眠研究的同时进行，以描述认知功能的变化，并检查呼吸周期或脑氧合是否单独或联合预测24个月内的认知衰退。此外，我们将探讨呼吸周期和脑氧合如何随时间变化和相互作用。关于睡眠质量、脑血管危险因素、身体活动和抑郁症状的数据将每6个月测量一次，因为这些测量值变化很快，可能会影响关键的结果测量值。除了作为对照组外，未表现出认知能力下降的受试者的数据将用于探索性分析，以确定呼吸周期和脑氧合的性别和种族相关差异。由于对老年人使用脑氧饱和度测定呼吸周期或脑氧合的了解甚少，这项前瞻性研究将为确定这些变量如何变化提供重要数据，并可用于预测精心筛选的老年人样本的认知能力下降。