Department of Anthropology, Dartmouth College, 6047 Hinman Box, 3 Tuck Mall, Hanover, NH, 03755 United States(1).
Center for Evaluation Research and Surveys, National Institute of Public Health, Cuernavaca, Morelos, Mexico.
Arch Gerontol Geriatr. 2019 Jul-Aug;83:161-168. doi: 10.1016/j.archger.2019.04.014. Epub 2019 Apr 29.
Alterations in sleep patterns are common among older adults; further, short and long sleep durations have been linked with impaired cognitive performance in older individuals. Yet most research examining these relationships has been cross-sectional, limited to high-income nations, and has failed to consider how changes in sleep duration may impact cognitive decline. The present longitudinal study uses nationally-representative data to test whether changes in sleep length among "healthy" baseline sleepers are associated with reduced cognitive function in older Mexican adults (>50 years old) at follow-up. Data were drawn from the first and second waves of the World Health Organization's Study on global AGEing and adult health. Self-report data captured sleep duration over two nights, and five cognitive tests (immediate and delayed verbal recall, forward and backward digit span, and verbal fluency) were used to measure various cognitive domains and create a composite z-score of cognitive performance. Linear regressions were performed to assess associations between sleep length changes and cognitive decline, controlling for relevant lifestyle and health factors. Increased sleep durations at follow-up among individuals who reported intermediate sleep durations (6-9 h/night) at baseline were significantly associated with greater rates of decline in overall cognitive function. Longer sleepers also trended toward greater rates of decline for attention/working memory and executive function. This study suggests that long sleep durations are a risk factor for certain types of impaired cognition among older adults living in a middle-income country. These findings are clinically important given the growing rates of dementia and aging populations globally.
睡眠模式的改变在老年人中很常见；此外，睡眠时间过短和过长都与老年人认知表现受损有关。然而，大多数研究这些关系的研究都是横断面的，仅限于高收入国家，并且没有考虑到睡眠时间的变化如何影响认知能力下降。本纵向研究使用全国代表性数据，测试在随访期间，“健康”基础睡眠者的睡眠时间变化是否与老年墨西哥成年人（>50 岁）认知功能下降有关。数据来自世界卫生组织全球老龄化和成人健康研究的第一波和第二波。自我报告的数据记录了两晚的睡眠时间，使用了五个认知测试（即时和延迟语言回忆、向前和向后数字跨度以及语言流畅性）来衡量各种认知领域，并创建了认知表现的综合 z 分数。进行线性回归以评估睡眠长度变化与认知能力下降之间的关联，同时控制相关的生活方式和健康因素。与基线时报告中间睡眠时间（6-9 小时/夜）的个体相比，随访时睡眠时间增加与整体认知功能下降的速度显著相关。较长的睡眠时间也与注意力/工作记忆和执行功能的下降速度呈正相关。这项研究表明，在中低收入国家，较长的睡眠时间是老年人某些类型认知障碍的一个风险因素。鉴于全球痴呆症和老龄化人口的增长速度，这些发现具有重要的临床意义。
