Vanke School of Public Health, Tsinghua University, Beijing, China.
Institute for Healthy China, Tsinghua University, Beijing, China.
Front Endocrinol (Lausanne). 2021 Nov 8;12:739277. doi: 10.3389/fendo.2021.739277. eCollection 2021.
To ascertain the possible cut point of tri-ponderal mass index (TMI) in discriminating metabolic syndrome (MetS) and related cardio-metabolic risk factors in Chinese and American children and adolescents.
A total of 57,201 Chinese children aged 7-18 recruited in 2012 and and 10,441 American children aged 12-18 from National Health and Nutrition Examination Survey (NHANES 2001-2014) were included to fit TMI percentiles. Participants were randomly assigned to a derivation set (75%) and validation set (25%). The cut points of TMI with the lowest misclassification rate under the premise of the highest area under curves (AUC) were selected for each sex, which were additionally examined in the validation set. All of data analysis was conducted between September and December in 2019.
TMI showed good capacity on discriminating MetS, with AUC of 0.7658 (95% CI: 0.7544-0.7770) to 0.8445 (95% CI: 0.8349-0.8537) in Chinese and 0.8871 (95% CI: 0.8663-0.9056) to 0.9329 (95% CI: 0.9166-0.9469) in American children. The optimal cut points were 14.46 kg/m and 13.91 kg/m for Chinese boys and girls, and 17.08 kg/m and 18.89 kg/m for American boys and girls, respectively. The corresponding misclassification rates were 17.1% (95% CI: 16.4-17.8) and 11.2% (95% CI: 9.9-12.6), respectively. Performance of these cut points were also examined in the validation set (sensitivity 67.7%, specificity 82.4% in Chinese; sensitivity 84.4%, specificity 88.7% in American children).
A sex- and ethnicity- specific single cut point of TMI could be used to distinguish MetS and elevated risk of cardio-metabolic factors in children and adolescents.
为了确定三比重指数（TMI）在区分中国和美国儿童青少年代谢综合征（MetS）及相关心血管代谢危险因素方面的可能切点。
共纳入 2012 年中国 7-18 岁儿童 57201 名和 2001-2014 年美国全国健康和营养检查调查（NHANES）中 12-18 岁儿童 10441 名，拟合 TMI 百分位数。参与者被随机分配到推导集（75%）和验证集（25%）。在曲线下面积（AUC）最高的前提下，选择 TMI 的切点，其错误分类率最低，每个性别均进行验证集检查。所有数据分析均在 2019 年 9 月至 12 月之间进行。
TMI 在区分 MetS 方面具有良好的能力，AUC 在中国儿童中为 0.7658（95%CI：0.7544-0.7770）至 0.8445（95%CI：0.8349-0.8537），在美国儿童中为 0.8871（95%CI：0.8663-0.9056）至 0.9329（95%CI：0.9166-0.9469）。中国男童和女童的最佳切点分别为 14.46kg/m 和 13.91kg/m，美国男童和女童的最佳切点分别为 17.08kg/m 和 18.89kg/m。相应的错误分类率分别为 17.1%（95%CI：16.4-17.8）和 11.2%（95%CI：9.9-12.6）。这些切点在验证集中的表现也进行了检查（中国儿童的灵敏度为 67.7%，特异性为 82.4%；美国儿童的灵敏度为 84.4%，特异性为 88.7%）。
TMI 的性别和种族特异性单一切点可用于区分儿童和青少年的 MetS 和心血管代谢危险因素升高。
