应用ROC曲线确定活动计数在青春期少年运动强度诊断中的最佳临界值

Determination of Best Cut off Value of Activity Count in Diagnosis Exercise Intensity of Adolescents by Receiver Operating Characteristic(ROC) Curve Analysis

研究目的:运用ROC曲线确定青春期少年不同运动强度的活动计数最佳临界值,为准确评估日常体力活动水平提供支撑。研究方法:通过便携式气体代谢分析仪(CosmedK4b2)和三轴运动传感器(ActiGraph GT3X)同步对80名11～14岁健康中学生(男性40名,女性40名)进行静息和8种常见体力活动的测试,通过ROC曲线下面积确定活动计数对于区分小、中、大活动强度的诊断能力;通过最大约登指数确定小、中、大运动强度的活动计数最佳临界点。结果:垂直轴在各种活动项目中占主要优势,ACxis1、VM2和VM3的变化趋势基本一致;ROC曲线可建立不同活动强度的ACxis1、VM2和VM3的活动计数最佳临界点(AUC∈[0.708,0.890],P<0.001);3 METs、6 METs和9 METs所对应的活动计数最佳临界点ACxis1为2 151counts/min、3 761counts/min、3 783counts/min;VM2为4 935counts/min、6 009counts/min、6 169counts/min;VM3为9 600counts/min、9 900counts/min、10 296counts/min。结论:ACxis1、VM2和VM3可有效反映人体运动状态,ACxis1、VM2和VM3的最佳临界值可有效诊断青春期少年的运动强度,小强度活动的活动计数最佳临界值为ACxis1<2 151counts/min、VM2<3 761counts/min、VM3<3 783counts/min;中等强度最佳临界值为2 151counts/min≤ACxis1<4 935counts/min,3 761counts/min≤VM2<6 009counts/min、3 783counts/min≤VM3<6 169counts/min;大强度活动的最佳临界值为4 935counts/min≤ACxis1<9 600counts/min、6 009counts/min≤VM2<9 900counts/min、6 169counts/min≤VM3<10 296counts/min;剧烈运动的最佳临界值为ACxis1≥9 600counts/min、VM2≥9 900counts/min、VM3≥10 296counts/min。

Objective：To determinate the best cut off value of different exercise intensity in adolescents by ROC Curve and aim to elevate validly the daily physical octivity level in future.Methods：The rest and the 8 activities was synchronous monitor by portable gas analyzer （Cosmed K4b2） and triaxial accelerometer （ActiGraph GT3X） in 80 health Chinese children aged 11-14 years （40 boys and 40 girls）.AUC （Area Under Curve） was to judge the diagnostic function of AC（Activity Count） for distinguishing the low,moderate or high exercise intensity.The maximum Youden value was used to determine the best cutoff point of different exercise intensity.Results：The vertical is predominant in various activities and the change trend of ACxis1,VM2 and VM3 is similar.The ROC curve can determine the best cut off point of ACxis1,VM2 and VM3 in diagnosis of exercise intensity（AUC∈[0.708,0.890],P〈0.001）.The best cutoff point of 3 METs,6 METs and 9 METs was respectively ACxis1（2 151 counts/min,3 761 counts/min,3 783 counts/min）,VM2 （4 935 counts/min,6 009 counts/min,6 169 counts/min） and VM3 （9 600 counts/min,9 900 counts/min and 10 296 counts/min）.Conclusions：ACxis1,VM2 and VM3 can reflect effective human moving state and the best cut off value of them can diagnosis valid the exercise intensity in adolescents.The best cut off value of light physical activity was ACxis1〈2 152 counts/min,VM2〈3 761 counts/min,VM3〈3 783 counts/min;moderate physical activity was 2 151 counts/min≤ACxis1〈4 935 counts/min,3 761 counts/min≤VM2〈6 009 counts/min,3 783 counts/min≤VM3〈6 169 counts/min,large physical activity was 4 935 counts/min≤ACxis1〈9 600 counts/min,6 009 counts/min≤VM2〈9 900 counts/min,6 169 counts/min≤VM3〈10 296 counts/min,and vigorous activity was ACxis1≥9 600 counts/min,VM2≥9 900 counts/min,VM3≥10 296 counts/min.