Research Centre in Physical Activity, Health and Leisure (CIAFEL), Faculty of Sport. University of Porto, Porto, Portugal.
Department of Physical Education, Sport and Human Movement, Autonomous University of Madrid, Madrid, Spain.
Int J Obes (Lond). 2019 Dec;43(12):2545-2554. doi: 10.1038/s41366-019-0439-4. Epub 2019 Aug 27.
The aims of the present study were: (i) to analyze the associations of the time spent in daily activities (i.e., lie, recline, passive sit, active sit, stand, walk at slow pace, walk at average pace, walk at brisk pace, and other activities) with body mass index (BMI) and waist circumference (WC); and (ii) to examine how theoretically reallocating time between these daily activities is associated with BMI and WC.
The sample included 437 older adults (288 women), aged 65 to 92 years, participating in the IMPACT65+ study. The time in daily activities was assessed by the Intelligent Device for Energy Expenditure and Activity (IDEEA). BMI and WC were measured following standardized procedures. Associations of daily activities with BMI and WC were examined using linear regression models adjusting for potential confounders. Isotemporal substitution models were performed to estimate the theoretical effect of replacing one activity with another activity while holding total time constant.
The time spent lying and reclining was associated with increased BMI and WC, while the time spent standing, walking at average pace, and walking at brisk pace was associated with decreased BMI and WC. Isotemporal substitution analyses revealed significant hypothetical reductions in BMI and WC when reallocating 15 min from lying or reclining to standing or walking at average pace. Moreover, replacing 15 min from any sedentary activity or light physical activity (except for walking at average pace) with an equal amount of time in walking at brisk pace was associated with lower BMI and WC.
This is the first study examining the activity specific and isotemporal associations of daily behaviors (considering body postures and movements) with overall and abdominal obesity in older people. The results could be used in the development of specific recommendations encouraging an active lifestyle in older people.
本研究旨在：（i）分析日常活动时间（即躺卧、斜倚、被动坐、主动坐、站立、慢步走、中速走、快步走和其他活动）与身体质量指数（BMI）和腰围（WC）的关系；（ii）探讨理论上在这些日常活动之间重新分配时间与 BMI 和 WC 的关系。
本研究的样本包括参加 IMPACT65+研究的 437 名年龄在 65 至 92 岁的老年人（288 名女性）。日常活动时间通过智能能量消耗和活动设备（IDEEA）进行评估。BMI 和 WC 按照标准化程序进行测量。使用线性回归模型调整潜在混杂因素后，对日常活动与 BMI 和 WC 的关系进行了分析。等时替代模型用于估计在保持总时间不变的情况下，用一种活动替代另一种活动的理论效果。
躺卧和斜倚时间与 BMI 和 WC 的增加有关，而站立、中速走和快步走时间与 BMI 和 WC 的减少有关。等时替代分析显示，当从躺卧或斜倚中重新分配 15 分钟到站立或中速走时，BMI 和 WC 会显著降低。此外，用 15 分钟的快步走替代任何久坐或轻体力活动（除了中速走），与 BMI 和 WC 的降低有关。
这是第一项研究，考察了老年人日常生活行为（考虑身体姿势和运动）与整体和腹部肥胖的特定活动和等时关联。研究结果可用于制定鼓励老年人积极生活方式的具体建议。
