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.

实验室和临床发现表明，低脑充氧的状态与老年人的认知下降和痴呆有关。 睡眠是低氧事件风险增加的时期；低呼吸周期性可能是识别睡眠期间脑充氧低的个体的重要指标。 我们以前的研究表明，呼吸衰竭的老年人的睡眠更加零散，振幅更低的三角洲睡眠和睡眠期间脑充氧的下降量更大。 这项纵向观察性研究的目的是（1）检查睡眠期间呼吸周期性，睡眠结构和脑充氧之间的关系； （2）检查在睡眠期间，单独还是组合在睡眠期间呼吸周期性或脑充氧，可以预测24个月内的认知能力下降； （3）探索呼吸周期性和脑充氧的变化如何在24个月内变化。一百六个社区居住的老年人，年龄70岁以上，将在基线和12个月和24个月的时间进行评估。呼吸周期性将根据呼吸电感量表的波形进行测量，并包括持续时间（SDIBI），频率（SDIBF）和呼吸周期振幅（SDIBF）变异性的平均度量。 标准的多聚会方法将用于测量睡眠结构，其中包括睡眠状态的比例，以及睡眠纺锤体，睡眠效益过渡，唤醒和K-复合物之间的平均间隔。 双重（左）脑血氧仪将用于测量平均5分钟左右5分钟的左脑氧气血红蛋白饱和度的最大变化。 为了描述认知功能的变化，并检查呼吸周期性或脑充氧是否单独或组合预测24个月内的认知能力下降，将同时衡量次要记忆，工作记忆和注意力的标准化测试。 此外，我们将探讨呼吸周期性和脑充氧如何随着时间的流逝而变化和相互作用。 睡眠质量，脑血管危险因素，体育锻炼和抑郁症状的数据将每6个月测量，因为这些措施可能会迅速变化，并可能影响关键的结果措施。 除了作为比较组外，未表现出认知能力下降的受试者的数据还将用于探索性分析中，以确定呼吸周期性和大脑氧合的性别和种族相关的差异。 由于对老年人使用脑血氧蛋白法的呼吸周期性或脑充氧知之甚少，因此这项前瞻性研究将提供重要的数据，以确定这些变量如何变化，并可以用于预测经过筛查的老年人样本中的认知下降。