腰围身高比对13～14岁少年肥胖的预测价值

Accuracy of Waist-height Ratio as Screening Obesity Method in Adolescents Aged 13～14 Years

目的：比较体重指数（BMI）、腰围身高比（WHtR）与体脂百分比（BF%）对少年肥胖判断的一致性。方法：13～14岁少年479人,测量身高、体重、腰围,生物电阻抗体成分仪测BF%。比较BMI和WHtR两方法与BF%法判断肥胖的相关性、两种方法对肥胖判断的可靠性与真实性。结果：对肥胖判断,（1）男女生BMI法和BF%法、WHtR法和BF%法均中度相关。（2）kappa检验,BMI法和BF%法一致性低（男k=0.50、女r=0.58）,WHtR法和BF%法一致性较高（男k=0.73、女r=0.62）。（3）ROC曲线下面积,男生,AUC（BMI）=0.71,AUC（WHtR）=0.86;女生AUC（BMI）=0.74,AUC（WHtR）=0.84,男女生均p〈0.01。（4）约登指数,BMI法低于WHtR法,BMI法（男0.42、女0.48）WHtR法（男0.73、女0.68）（5）BMI法的灵敏度低,WHtR法灵敏度高。研究结论：对13～14岁少年肥胖的判断,WHtR法判断的效果优于BMI;对非肥胖的判断,BMI和WHtR两种方法结果相似。使用现有的BMI界值可能会遗漏部分肥胖少年,而腰围身高比对肥胖的判断效果可能更优。建议今后对青少年肥胖的筛检,可加入腰围身高比作为一项重要的参考指标。

The objective of this study was to compare the consistency of screening obesity on the methods of body mass index（BMI）,waist-height ratio（WHtR）and body fat percentage（BF%）in order to provide more evidence with the adolescents obesity prevention.479 adolescents aged 13~14years were measured on the height,weight,and waist circumference.The bioelectrical impedance analysis were used to measure the body fat.The correlation and agreement of BMI,W HtR with BF% was adopted to screen the obese adolescents.Results：1）There were a moderate correlation between BMI and BF%（boys,r=0.55,girls,r=0.61）,and between WHtRand BF%（boys,r=0.73,girls,r=0.62）.2）The kappa values between WHtR and BF% was higher（boys,k=0.73,girls,k=0.62）than those of BMI and BF%（boys,k=0.50,girls,k=0.58）.3）Areas under the ROC were significantly bigger of WHtR than those of BMI.For boys,AUC（BMI）equaled 0.71 and AUC（WHtR）equaled 0.86.For girls,AUC（BMI）equaled 0.74,AUC（WHtR）equaled 0.84.p0.01.4）Youden＇s indexes of WHtR were higher than those of BMI.The formers were 0.73 for boys and 0.68 for girls.The latter＇s were 0.42 for boys and o.48 for girls.5）The sensitivity of BMI was lower than WHtR,but the specificity and positive likelihood were higher than WHtR.It could be seen that for the adolescents of 13~14years old,the method of WHtR was better than BMI screening the obesity.The two methods were similar in screening the nonobesity.With the current cut-point of BMI to determine the obesity,some fat adolescents might be ignored.The indicator of waist to height ratio could be better than BMI.It was suggested that WHtR would be added to screen obesity ofadolescents in the future.