Change 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。基于现有的横断面研究，尚不清楚认知功能受损是否会导致睡眠障碍，反之亦然。此外，大多数研究都依赖于对睡眠的主观评估，这在老年人身上尤其不准确。我们和其他人也发现，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关联是否由于睡眠效率低下而独立于间歇性缺氧。其潜在机制尚不清楚。在多中心骨质疏松性骨折研究（SOF）的第八次检查中，我们使用腕动仪客观地测量了bb103000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100万名老年妇女骨质疏松性骨折的危险因素。自基线（1986- 1988）起，每2年重复一次诊所就诊。所有参与者每三年联系一次，以评估意外跌倒、骨折和死亡。我们建议在检查9期间在两个诊所对700名老年妇女进行重复活动描记，并进行夜间血氧测定和扩展的一系列认知功能测试。在这个独特的、特征鲜明的老年妇女队列中，这些额外的措施将使我们能够实现以下具体目标：1)探索睡眠和认知功能之间的纵向关联；2)确定活动图睡眠质量和间歇性缺氧（使用血氧仪）与特定认知功能领域的独立关系；3)检验活动睡眠质量和间歇性缺氧对随后死亡风险的独立相关性；4)确定炎症生化指标（血清IL-6和CRP）、血糖控制指标（果糖胺）或氧化负荷（髓过氧化物酶）是否介导睡眠、认知和死亡之间的关系。

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.