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)是美国新出现的流行病；布莱克 成年人尤其容易受到伤害。没有有效的预防战略来针对和优化复原力 ADRD，到2060年，1400万美国成年人将与ADRD一起生活，相关的经济负担为511美元 到2040年将达到10亿。虽然体力活动一直被认为是一种可修改的保护性因素， 预防认知衰退和延缓痴呆症发病的年龄，大多数证据都是基于报道的 对休闲时间中等到剧烈的体力活动(MVPA)的估计，这提供了一种 对这种复杂的行为表型的描述不完整。成年人醒着的时间大约有95% 长时间久坐或在光强度下进行体力活动；然而，探索 这些不同强度类别之间的相互关系。此外，只有不到10%的成年人积累了足够的 MVPA以满足建议，这一流行率估计在黑人成年人中甚至更低。研究表明， 还证明了睡眠障碍，包括睡眠时间短，昼夜节律紊乱，以及 睡眠呼吸障碍可能会增加认知障碍的风险。然而，这一证据仍在不断涌现。 此外，与白人相比，黑人成年人睡眠障碍的发生率更高。尽管有潜在的 醒着行为和睡眠行为对优化认知韧性的重要性，人们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，我们建议杰克逊心脏研究(JHS)24小时 活动周期研究(Jackson 24H-ACT)，资助的JHS考试4(2020-22)的四年辅助研究。这个 杰克逊24H-ACT研究的总体目标是量化24小时活动周期行为并估计 清醒(久坐至高强度体力活动)和睡眠(持续时间和睡眠)的独立和联合作用 质量特征)行为，以优化认知韧性。参加考试4的所有参与者以及世卫组织 愿意连续七天同时佩戴加速度计和睡眠活动记录仪手表的人 被邀请参加。排除标准包括：不能走动或医生指示不能 体力活动。杰克逊24H-ACT辅助研究措施包括：(1)加速测速和(2)睡眠 作为现有JHS数据的补充，以及将作为考试4的一部分收集的数据。 为了实现这些目标，我们建议研究24小时活动的独立和联合联系 循环行为：(目标1)认知功能；(目标2)脑血管疾病的亚临床标志物 (例如，脑白质高信号体积)、脑白质微结构完整性和神经变性(例如 海马区和总脑体积)通过脑磁共振(MRI)成像进行量化；以及(目标3) 轻度认知障碍(MCI)和痴呆症的患病率。按性别、年龄时代划分的潜在缓和(&lt；65 与≥65岁相比)，教育程度/识字率和ɛ4基因也将被评估。杰克逊24H-ACT将 提供有关24小时活动周期在促进黑人成年人认知韧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.