Kumahara Hideaki, Schutz Yves, Ayabe Makoto, Yoshioka Mayumi, Yoshitake Yutaka, Shindo Munehiro, Ishii Kojiro, Tanaka Hiroaki
Laboratory of Physiology, Faculty of Medicine, University of Lausanne, Lausanne, Switzerland.
Br J Nutr. 2004 Feb;91(2):235-43. doi: 10.1079/BJN20031033.
Assessing the total energy expenditure (TEE) and the levels of physical activity in free-living conditions with non-invasive techniques remains a challenge. The purpose of the present study was to investigate the accuracy of a new uniaxial accelerometer for assessing TEE and physical-activity-related energy expenditure (PAEE) over a 24 h period in a respiratory chamber, and to establish activity levels based on the accelerometry ranges corresponding to the operationally defined metabolic equivalent (MET) categories. In study 1, measurement of the 24 h energy expenditure of seventy-nine Japanese subjects (40 (SD 12) years old) was performed in a large respiratory chamber. During the measurements, the subjects wore a uniaxial accelerometer (Lifecorder; Suzuken Co. Ltd, Nagoya, Japan) on their belt. Two moderate walking exercises of 30 min each were performed on a horizontal treadmill. In study 2, ten male subjects walked at six different speeds and ran at three different speeds on a treadmill for 4 min, with the same accelerometer. O2 consumption was measured during the last minute of each stage and was expressed in MET. The measured TEE was 8447 (SD 1337) kJ/d. The accelerometer significantly underestimated TEE and PAEE (91.9 (SD 5.4) and 92.7 (SD 17.8) % chamber value respectively); however, there was a significant correlation between the two values (r 0.928 and 0.564 respectively; P<0.001). There was a strong correlation between the activity levels and the measured MET while walking (r(2) 0.93; P<0.001). Although TEE and PAEE were systematically underestimated during the 24 h period, the accelerometer assessed energy expenditure well during both the exercise period and the non-structured activities. Individual calibration factors may help to improve the accuracy of TEE estimation, but the average calibration factor for the group is probably sufficient for epidemiological research. This method is also important for assessing the diurnal profile of physical activity.
运用非侵入性技术评估自由生活条件下的总能量消耗（TEE）和身体活动水平仍是一项挑战。本研究的目的是调查一种新型单轴加速度计在呼吸室内24小时期间评估TEE和身体活动相关能量消耗（PAEE）的准确性，并根据对应于操作定义的代谢当量（MET）类别的加速度计范围确定活动水平。在研究1中，对79名日本受试者（40（标准差12）岁）在一个大型呼吸室内进行了24小时能量消耗测量。测量期间，受试者在腰部佩戴一个单轴加速度计（Lifecorder；日本名古屋铃木健株式会社）。在水平跑步机上进行了两次每次30分钟的中等强度步行锻炼。在研究2中，10名男性受试者使用同一加速度计在跑步机上以六种不同速度行走、三种不同速度跑步，每次持续四分钟。在每个阶段的最后一分钟测量氧气消耗量，并以MET表示。测得的TEE为8447（标准差1337）kJ/天。加速度计显著低估了TEE和PAEE（分别为呼吸室测量值的91.9（标准差5.4）%和92.7（标准差17.8）%）；然而，两者之间存在显著相关性（r分别为0.928和0.564；P<0.001）。步行时活动水平与测得的MET之间存在强相关性（r² 0.93；P<0.001）。尽管在24小时期间TEE和PAEE被系统性低估，但加速度计在运动期间和非结构化活动期间对能量消耗的评估效果良好。个体校准因子可能有助于提高TEE估计的准确性，但该组的平均校准因子可能足以用于流行病学研究。这种方法对于评估身体活动的昼夜分布也很重要。
