儿童青少年24 h活动行为与肥胖相关指标的关系

目的 采用成分数据分析法探讨儿童青少年24 h活动行为与肥胖指标间的关联并探究活动行为间等时替代后指标产生的定量变化，为儿童青少年预防肥胖提供具体的活动行为建议。方法 2021年6月在山西省太原市1所小学和1所中学按照随机整群抽样方法，从8个班级中选取231名学生。采用ActiGraph GT3X+加速度计测试学生24 h活动行为，采用Inbody J20身体成分分析仪，通过生物电阻抗法(BIA)测试身体成分。使用成分多元线性回归分析探讨各成分与肥胖指标间的关系，采用某一行为的30 min替代另一行为，预测替代后对结局变量产生的变化。结果 调整身高、体重、年龄、性别等协变量后，相对于久坐行为(SB)、睡眠(SLP)、低强度身体活动(LPA)所花费时间，学生中高强度身体活动(MVPA)所花费时间与去脂体重指数(FFMI)呈正相关(β=0.40)、与腰围(WC)(β=-2.50)和腰臀比(WHR)(β=-0.04)呈负相关；相对于SB、SLP、MVPA所花费时间，LPA所花费时间与WHR(β=0.06)呈正相关(P值均<0.05)。30 min/d的MVPA分别替代SLP、SB、LP...

Relationship between 24-hour movement behavior and obesity indicators in children and adolescents

  Objective  The method of compositional data analysis was used to explore the relationship between 24-hour movement behavior and obesity indicators, and to examine the difference of quantitative effect on obesity indicators when one behavior replaced another behavior, so as to provide specific movement behavior advice for weight control in children and adolescents.  Methods  In June 2021, 231 students from eight classes in a primary school and a middle school in Taiyuan City, Shanxi Province were voluntarily recruited by using random cluster sampling. ActiGraph GT3X+ accelerometer was used to measure 24-hour movement behavior and Inbody J20 body composition analyzer was used to measure body composition. The relationship between each component and obesity indicators was analyzed by compositional multivariate linear regression model. In addition, 30 minutes of one behavior was used to replace another behavior to predict the effect difference of the outcomes.  Results  After adjusting for covariates such as height, weight, age, and sex, compared with time spent in sedentary behavior(SB), sleep (SLP) and light physical activity (LPA), time spent on moderate to vigorous physical activity (MVPA) was positively correlated with fat-free mass index (FFMI) (β=0.40, P < 0.05), negatively correlated with waist circumference (WC) (β=-2.50, P < 0.05) and waist-hip ratio (WHR) (β=-0.04, P < 0.05). Compared with SB, SLP and MVPA, time spent on LPA was positively correlated with WHR (β=0.06, P < 0.05). If MVPA of 30 min/d replaces SLP, SB, and LPA respectively, WC and WHR decrease 1.10, 1.10, 1.34 cm and 0.02, 0.02, 0.02 respectively, and FFMI increases 0.19, 0.19, 0.15 kg/m2 respectively.  Conclusion  In 24 h movement behavior, with consistent level of sedentary behavior, sleep or low-intensity movement behavior, maintaining a high level of MVPA and replacing sedentary with active activities are crucial for optimal abdominal fat and fat free mass in children and adolescents.