Performance Department, Swim Ireland, Sport HQ, Dublin, Ireland.
Physical Activity for Health Research Cluster, University of Limerick, Limerick, Ireland.
Sports Med. 2020 Jan;50(1):205-217. doi: 10.1007/s40279-019-01153-2.
All physical activity (PA) behaviours undertaken over the day, including sleep, sedentary time, standing time, light-intensity PA (LIPA) and moderate-to-vigorous PA (MVPA) have the potential to influence cardiometabolic health. Since these behaviours are mutually exclusive, standard statistical approaches are unable to account for the impact on time spent in other behaviours.
By employing a compositional data analysis (CoDA) approach, this study examined the associations of objectively measured time spent in sleep, sedentary time, standing time, LIPA and MVPA over a 24-h day on markers of cardiometabolic health in older adults.
Participants (n =366; 64.6 years [5.3]; 46% female) from the Mitchelstown Cohort Rescreen Study provided measures of body composition, blood lipid and markers of glucose control. An activPAL3 Micro was used to obtain objective measures of sleep, sedentary time, standing time, LIPA and MVPA, using a 7-day continuous wear protocol. Regression analysis, using geometric means derived from CoDA (based on isometric log-ratio transformed data), was used to examine the relationship between the aforementioned behaviours and markers of cardiometabolic health.
Standing time and LIPA showed diverging associations with markers of body composition. Body mass index (BMI), body mass and fat mass were negatively associated with LIPA (all p <0.05) and positively associated with standing time (all p <0.05). Sedentary time was also associated with higher BMI (p <0.05). No associations between blood markers and any PA behaviours were observed, except for triglycerides, which were negatively associated with standing time (p < 0.05). Reallocating 30 min from sleep, sedentary time or standing time, to LIPA, was associated with significant decreases in BMI, body fat and fat mass.
This is the first study to employ CoDA in older adults that has accounted for sleep, sedentary time, standing time, LIPA and MVPA in a 24-h cycle. The findings support engagement in LIPA to improve body composition in older adults. Increased standing time was associated with higher levels of adiposity, with increased LIPA associated with reduced adiposity; therefore, these findings indicate that replacing standing time with LIPA is a strategy to lower adiposity.
一天中进行的所有身体活动（PA）行为，包括睡眠、久坐时间、站立时间、低强度 PA（LIPA）和中高强度 PA（MVPA），都有可能影响心血管代谢健康。由于这些行为是互斥的，标准的统计方法无法考虑它们对其他行为时间的影响。
本研究通过采用成分数据分析（CoDA）方法，考察了老年人 24 小时内睡眠、久坐时间、站立时间、LIPA 和 MVPA 时间与心血管代谢健康指标之间的关系。
Mitchelstown 队列再筛查研究的参与者（n=366；64.6 岁[5.3]；46%女性）提供了身体成分、血脂和血糖控制标志物的测量值。使用 activPAL3 Micro 通过 7 天连续佩戴协议获得睡眠、久坐时间、站立时间、LIPA 和 MVPA 的客观测量值。使用 CoDA（基于等比对数转换数据）得出的几何平均值进行回归分析，以检验上述行为与心血管代谢健康标志物之间的关系。
站立时间和 LIPA 与身体成分标志物呈相反的关联。BMI、体重和体脂肪量与 LIPA 呈负相关（均 P<0.05），与站立时间呈正相关（均 P<0.05）。久坐时间也与较高的 BMI 相关（P<0.05）。除了甘油三酯与站立时间呈负相关（P<0.05）外，没有观察到任何 PA 行为与血液标志物之间的关联。将 30 分钟从睡眠、久坐时间或站立时间重新分配给 LIPA，与 BMI、体脂肪和体脂肪量的显著降低相关。
这是第一项在老年人中采用 CoDA 方法的研究，该研究在 24 小时周期内考虑了睡眠、久坐时间、站立时间、LIPA 和 MVPA。研究结果支持老年人进行 LIPA 以改善身体成分。增加站立时间与更高的肥胖水平相关，而增加 LIPA 与降低肥胖水平相关；因此，这些发现表明，用 LIPA 代替站立时间是降低肥胖的一种策略。
