Tudor-Locke C, Mire E F, Barreira T V, Schuna J M, Chaput J-P, Fogelholm M, Hu G, Kurpad A, Kuriyan R, Lambert E V, Maher C, Maia J, Matsudo V, Olds T, Onywera V, Sarmiento O L, Standage M, Tremblay M S, Zhao P, Church T S, Katzmarzyk P T
Department of Kinesiology, School of Public Health and Health Sciences, University of Massachusetts Amherst, Amherst, MA, USA; Pennington Biomedical Research Center, Baton Rouge, LA, USA.
Pennington Biomedical Research Center , Baton Rouge, LA, USA.
Int J Obes Suppl. 2015 Dec;5(Suppl 2):S47-52. doi: 10.1038/ijosup.2015.19. Epub 2015 Dec 8.
We describe the process of identifying and defining nocturnal sleep-related variables (for example, movement/non-movement indicators of sleep efficiency, waking episodes, midpoint and so on) using the unique 24-h waist-worn free-living accelerometer data collected in the International Study of Childhood Obesity, Lifestyle and the Environment (ISCOLE).
Seven consecutive days of 24-h waist-worn accelerometer (GT3X+, ActiGraph LLC) data were collected from over 500 children at each site. An expert subgroup of the research team with accelerometry expertize, frontline data collectors and data managers met on several occasions to categorize and operationally define nocturnal accelerometer signal data patterns. The iterative process was informed by the raw data drawn from a sub set of the US data, and culminated in a refined and replicable delineated definition for each identified nocturnal sleep-related variable. Ultimately based on 6318 participants from all 12 ISCOLE sites with valid total sleep episode time (TSET), we report average clock times for nocturnal sleep onset, offset and midpoint in addition to sleep period time, TSET and restful sleep efficiency (among other derived variables).
Nocturnal sleep onset occurred at 2218 hours and nocturnal sleep offset at 0707 hours. The mean midpoint was 0243 hours. The sleep period time of 529.6 min (8.8 h) was typically accumulated in a single episode, making the average TSET very similar in duration (529.0 min). The mean restful sleep efficiency ranged from 86.8% (based on absolute non-movement of 0 counts per minute) to 96.0% (based on relative non-movement of <100 counts per minute).
These variables extend the potential of field-based 24-h waist-worn accelerometry to distinguish and categorize the underlying robust patterns of movement/non-movement signals conveying magnitude, duration, frequency and periodicity during the nocturnal sleep period.
我们描述了利用在国际儿童肥胖、生活方式与环境研究（ISCOLE）中收集的独特的24小时腰部佩戴式自由生活加速度计数据，识别和定义夜间睡眠相关变量（例如，睡眠效率的运动/非运动指标、清醒发作、中点等）的过程。
在每个研究地点，从500多名儿童中收集连续7天的24小时腰部佩戴式加速度计（GT3X +，ActiGraph LLC）数据。研究团队中具有加速度测量专业知识的专家小组、一线数据收集者和数据管理者多次会面，对夜间加速度计信号数据模式进行分类和操作定义。该迭代过程以从美国数据子集中提取的原始数据为依据，并最终为每个识别出的夜间睡眠相关变量形成了一个精确且可重复的界定定义。最终，基于来自ISCOLE所有12个研究地点的6318名具有有效总睡眠时间（TSET）的参与者，我们报告了夜间睡眠开始、结束和中点的平均时钟时间，以及睡眠时间、TSET和安静睡眠效率（以及其他派生变量）。
夜间睡眠开始时间为22:18，夜间睡眠结束时间为07:07。平均中点时间为02:43。睡眠时间为529.6分钟（8.8小时），通常集中在一个时间段内，使得平均TSET在时长上非常相似（529.0分钟）。安静睡眠效率的平均值范围从86.8%（基于每分钟0计数的绝对无运动）到96.0%（基于每分钟<100计数的相对无运动）。
这些变量扩展了基于现场的24小时腰部佩戴式加速度测量法的潜力，以区分和分类在夜间睡眠期间传达幅度、持续时间、频率和周期性的运动/非运动信号的潜在稳健模式。
