Gildner Theresa E, Liebert Melissa A, Kowal Paul, Chatterji Somnath, Snodgrass J Josh
Department of Anthropology, University of Oregon, Eugene, OR.
World Health Organization, Geneva, Switzerland ; University of Newcastle Research Centre on Gender, Health, and Ageing, Newcastle, NSW, Australia.
J Clin Sleep Med. 2014 Jun 15;10(6):613-21. doi: 10.5664/jcsm.3782.
Alterations in sleep architecture are common among older adults. Previous studies have documented associations between sleep duration, sleep quality, and cognitive performance in older individuals, yet few studies have examined these trends using population-based samples from non-Western societies. The present cross-sectional study uses nationally representative datasets from six countries to test several hypotheses related to sleep patterns and cognitive function.
Data were drawn from the first wave of the World Health Organization's study on global ageing and adult health (SAGE), a longitudinal study using samples of older adults (≥ 50 years old) in 6 middle-income countries (China, Ghana, India, Russian Federation, South Africa, and Mexico). Self-report data provided information on sleep quality and sleep duration over the previous 2 nights, and 5 cognitive tests (immediate and delayed verbal recall, forward and backward digit span, and verbal fluency) were used to create a composite z-score of cognitive performance.
Individuals with intermediate sleep durations (> 6-9 h/night) exhibited significantly higher cognitive scores than individuals with short sleep (0-6 h/night; p < 0.001) or long sleep duration (> 9 h/night; p < 0.001). Self-reported sleep quality was positively correlated with cognitive z-score (p < 0.05). Significant sex differences were observed; men generally had higher sleep quality and cognitive scores, while women reported longer sleep durations.
This study documented positive correlations between cognitive scores and sleep quality, and between cognitive z-scores and intermediate sleep duration. These findings are clinically important given the growing rates of dementia and aging populations globally.
睡眠结构改变在老年人中很常见。以往研究记录了老年人睡眠时间、睡眠质量与认知能力之间的关联，但很少有研究使用非西方社会基于人群的样本检验这些趋势。本横断面研究使用来自六个国家具有全国代表性的数据集，以检验与睡眠模式和认知功能相关的几个假设。
数据取自世界卫生组织全球老龄化与成人健康研究（SAGE）的第一波，这是一项纵向研究，使用了6个中等收入国家（中国、加纳、印度、俄罗斯联邦、南非和墨西哥）的老年人（≥50岁）样本。自我报告数据提供了前两晚的睡眠质量和睡眠时间信息，并使用5项认知测试（即时和延迟言语回忆、顺背和倒背数字广度以及言语流畅性）来创建认知能力的综合z分数。
睡眠时间中等（>6-9小时/晚）的个体的认知分数显著高于睡眠时间短（0-6小时/晚；p<0.001）或睡眠时间长（>9小时/晚；p<0.001）的个体。自我报告的睡眠质量与认知z分数呈正相关（p<0.05）。观察到显著的性别差异；男性通常睡眠质量和认知分数更高，而女性报告的睡眠时间更长。
本研究记录了认知分数与睡眠质量之间以及认知z分数与中等睡眠时间之间的正相关。鉴于全球痴呆症发病率和老龄化人口不断增加，这些发现具有重要临床意义。
