Changes in Sleep and Cognition in Older Women

描述(申请人提供)：睡眠障碍常见于认知能力差的患者。根据现有的横断面研究，尚不清楚认知功能受损是否会导致睡眠障碍，或者反之亦然。此外，大多数研究依赖于对睡眠的主观评估，这在老年受试者中尤其不准确。我们和其他人还发现，睡眠质量差与死亡风险增加有关。然而，现有的研究无法测试这种联系是否由于睡眠效率低下而与间歇性低氧无关。其潜在机制仍不清楚。在对骨质疏松性骨折(SOF)的多中心研究的第八次检查中，我们使用腕部活动描记术客观地测量了3000名老年妇女(平均年龄84岁)的睡眠。SOF是一项由NIAMS/NIA支持的多中心观察性研究，旨在确定10,000名老年女性骨质疏松性骨折的风险因素。自基线(1986-1988年)以来，大约每两年重复一次诊所就诊。每三年联系一次所有参与者，以评估事故跌倒、骨折和死亡情况。我们建议在检查9期间，对两个诊所的700名老年女性重复活动描记，并进行通宵血氧量测定和一系列延长的认知功能测试。在这个独特的、特征良好的老年女性队列中，这些额外的测量将使我们能够解决以下具体目标：1)探索睡眠和认知功能之间的纵向联系；2)确定活动睡眠质量和间歇性低氧与认知功能特定领域的独立关系；3)测试活动睡眠质量和间歇性低氧对随后死亡风险的独立关联；4)确定炎症生化标志物(血清IL-6和CRP)、血糖控制措施(果糖胺)或氧化负荷(髓过氧化物酶)是否在睡眠、认知和死亡之间起中介作用。

DESCRIPTION (provided by applicant): Disturbed sleep is commonly observed in patients with poor cognition. Based on existing cross sectional studies, it is unclear whether impaired cognitive function leads to sleep disturbance, or vice versa. Furthermore, most studies have relied on subjective assessment of sleep, which is particularly inaccurate in elderly subjects. We and others have also found that poor sleep quality is associated with increased risk of mortality. However, existing studies are unable to test whether this association is due to poor sleep efficiency independent of intermittent hypoxia. The underlying mechanisms remain unclear. During an eighth examination in the multi-center Study of Osteoporotic Fractures (SOF), we used wrist actigraphy to objectively measure sleep in > 3000 older women (mean age 84). SOF, a multi-center observational study supported by NIAMS/NIA, was designed to determine risk factors for osteoporotic fractures in > 10,000 older women. Since baseline (1986-88), clinic visits were repeated about every 2 years. All participants are contacted tri-annually to assess incident falls, fractures and deaths. We propose to repeat actigraphy, and perform overnight oximetry and an extended battery of cognitive function tests in 700 older women at two clinic sites during Exam 9. These additional measures in this unique, well-characterized cohort of older women will enable us to address the following specific aims: 1) to explore the longitudinal associations between sleep and cognitive function; 2) to determine the independent relationships of actigraphic sleep quality and intermittent hypoxia (using oximetry) with specific domains of cognitive function; 3) to test the independent associations of actigraphic sleep quality and intermittent hypoxia on risk of subsequent mortality; 4) To determine whether biochemical markers of inflammation (serum IL-6 and CRP), measures of glycemic control (fructosamine), or oxidative burden (myeloperoxidase) mediate the relationships between sleep, cognition and death.