24-hour Activity Cycles to Optimize Cognitive Resilience to Alzheimer's Disease in African Americans: The Jackson Heart Study

摘要 阿尔茨海默病和相关痴呆症（ADRD）是美国的一种新兴流行病;黑人 成年人尤其脆弱。如果没有有效的预防战略， ADRD，到2060年将有1400万美国成年人患有ADRD，相关的经济负担为511美元 到2040年达到10亿美元。虽然身体活动一直被认为是一个可改变的保护因素， 预防认知能力下降和延迟痴呆发作的年龄，大多数证据是基于报告的 估计休闲时间中度到剧烈强度的体力活动（MVPA），这提供了一个 这种复杂行为表型的不完整表征。成年人大约有95%的清醒时间 小时久坐或轻度体力活动;然而，有有限的研究探索 这些不同强度类别的相互关系。此外，只有不到10%的成年人积累了足够的 MVPA以满足建议，而这一患病率估计在黑人成年人中甚至更低。研究 还表明，睡眠障碍，包括睡眠时间短，昼夜节律紊乱， 睡眠呼吸障碍可能会增加认知障碍的风险。然而，这一证据仍在出现。 此外，与白人相比，黑人成年人睡眠障碍的患病率更高。尽管潜在的 清醒和睡眠行为对优化认知弹性的重要性，经常研究它们的影响。 与世隔绝为了解决这些关键的研究差距，我们提出了杰克逊心脏研究（JHS）24小时 活动周期研究（杰克逊24 H-ACT），为期四年的辅助研究资助JHS考试4（2020-22）。的 杰克逊24小时ACT研究的总体目标是量化24小时活动周期行为， 清醒（久坐到剧烈强度的身体活动）和睡眠（持续时间和 质量特征）行为，以优化认知弹性。参加考试4的所有参加者， 愿意连续七天同时佩戴加速度计和睡眠活动记录手表， 被邀请参加。排除标准包括：不能走动或医生指示不能走动。 身体活跃。杰克逊24 H-ACT辅助研究指标包括：（1）加速度计和（2）睡眠 活动记录仪，补充现有的JHS数据，以及将作为检查4的一部分收集的数据。到 为了实现这些目标，我们建议检查24小时活动的独立和联合关联， 循环行为：（目的1）认知功能;（目的2）脑血管疾病的亚临床标志物 (e.g.白色物质高信号体积）、白色物质微结构完整性和神经变性（例如， 海马和总脑体积）由脑磁共振（MRI）成像定量;和（目的3） 轻度认知障碍（MCI）和痴呆症的患病率。按性别、年龄阶段（<65岁）列出的潜在调节作用 与≥65岁相比）、教育/识字和APOE β 4基因型也将进行评估。杰克逊24小时ACT将 提供了关于24小时活动周期在促进黑人成年人认知弹性方面的作用的新信息。

ABSTRACT Alzheimer’s Disease and Related Dementias (ADRD) is an emerging epidemic in the United States; Black adults are particularly vulnerable. Without effective prevention strategies to target and optimize resilience to ADRD, 14 million U.S. adults will be living with ADRD by 2060, with an associated financial burden of $511 billion by 2040. While physical activity has been consistently identified as a modifiable, protective factor to prevent cognitive decline and delay age of dementia onset, the majority of this evidence is based on reported estimates of leisure-time moderate to vigorous intensity physical activity (MVPA), which provides an incomplete characterization of this complex behavioral phenotype. Adults spend approximately 95% of waking hours sedentary or in light intensity physical activity; however, there is limited research exploring the interrelations of these different intensity categories. Further, less than 10% of adults accumulate sufficient MVPA to meet recommendations, and this prevalence estimate is even lower in Black adults. Studies have also demonstrated that sleep disturbances, including short sleep duration, circadian rhythm disturbances, and sleep-disordered breathing may increase risk of cognitive impairment. However, this evidence is still emerging. Further, Black adults have a higher prevalence of disordered sleep compared to Whites. Despite the potential importance of both waking and sleep behaviors to optimize cognitive resilience, their impacts are often studied in isolation. To address these critical research gaps, we propose the Jackson Heart Study (JHS) 24-Hour Activity Cycle Study (Jackson 24H-ACT), a four-year ancillary study to the funded JHS Exam 4 (2020-22). The overall goal of the Jackson 24H-ACT Study is to quantify 24-hour activity cycle behaviors and estimate the independent and joint roles of waking (sedentary to vigorous intensity physical activity) and sleep (duration and quality characteristics) behaviors to optimize cognitive resilience. All participants attending Exam 4 and who are willing to concurrently wear an accelerometer and sleep actigraphy watch for seven consecutive days will be invited to participate. Exclusion criteria include: unable to ambulate or physician instruction not to be physically active. Jackson 24H-ACT ancillary study measures include: (1) accelerometry and (2) sleep actigraphy, which complement extant JHS data, and data that will be collected as part of Exam 4. To accomplish these goals, we propose to examine the independent and joint associations of 24-hour activity cycle behaviors with: (Aim 1) cognitive functioning; (Aim 2) subclinical markers of cerebrovascular disease (e.g. white matter hyperintensity volumes), white matter microstructural integrity, and neurodegeneration (e.g. hippocampal and total brain volumes) quantified from brain magnetic resonance (MRI) imaging; and (Aim 3) the prevalence of mild cognitive impairment (MCI) and dementia. Potential moderation by sex, age epoch (<65 versus ≥65 years), education/literacy, and APOE ɛ4 genotype will also be evaluated. Jackson 24H-ACT will provide novel information on the role of 24-hour activity cycles in promoting cognitive resilience in Black adults.