Marchuk Institute of Numerical Mathematics, Russian Academy of Sciences, Gubkin Str. 8, 119333, Moscow, Russia; Department of Health Statistics Analysis, Federal Research Institute for Health Organization and Informatics, Dobrolyubov Str. 11, 127254, Moscow, Russia.
Department of Environmental Health, Harvard T.H. Chan School of Public Health, 665 Huntington Avenue, Boston, MA, 02115, USA.
Clin Nutr ESPEN. 2020 Feb;35:153-161. doi: 10.1016/j.clnesp.2019.10.007. Epub 2019 Nov 16.
BACKGROUND & AIMS: Body mass index is a simple anthropometric measure (kg/m) used as an indirect estimate of body fat in individuals, and in assessments of population health and comparisons between populations. Bioelectrical impedance analysis (BIA) is often used to provide additional information on body fat and fat-free mass, and has been used to generate body composition reference data in national health surveys. However, BIA measurements are known to be device-specific and there are few published studies comparing results from different BIA instruments. Therefore, we compared the performance of two BIA instruments in the Russian Children's Study (RCS) of male growth, pubertal development and maturation.
Paired BIA measurements were obtained using the Tanita BC-418MA (Tanita Corp., Tokyo, Japan) and ABC-01 'Medas' (Medas Ltd, Moscow, Russia) BIA instruments. Cross-sectional data on 236 RCS subjects aged 18-22 years were used for the BIA comparison and the development of a conversion formula between measured resistances; follow-up data (n = 96) were used for validation of the conversion formula.
Whole-body resistances were highly correlated (Spearman rho = 0.95), but fat mass (FM) estimates were significantly higher with the Medas than the Tanita device (median difference 3.3 kg, 95% CI: 2.9, 3.6 kg) with large limits of agreement (LoA) for the FM difference (-2.0, 8.6 kg). A conversion formula between the resistances (Res) was obtained: Medas Res = 0.882 × Tanita Res+26.2 (r = 0.91, SEE = 17.6 Ohm). After applying the conversion formula to Tanita data and application of the Medas assessment algorithm, the 'converted' Tanita FM estimates closely matched the Medas original estimates (median difference -0.1 kg, 95% CI: -0.3, 0.2 kg), with relatively small LoA for the FM difference (-2.3 to 2.1 kg), suggesting potential interchangeability of the ABC-01 'Medas' and Tanita BC-418MA data at the group level.
Our results support the importance of cross-calibration of BIA instruments for population comparisons and proper data interpretation in clinical and epidemiological studies.
体重指数（BMI）是一种简单的人体测量指标（kg/m），用于间接估计个体体脂肪，以及评估人群健康状况和人群间比较。生物电阻抗分析（BIA）常用于提供关于体脂肪和去脂体重的额外信息，并且已用于在国家健康调查中生成人体成分参考数据。然而，BIA 测量结果因设备而异，并且很少有发表的研究比较不同 BIA 仪器的结果。因此，我们比较了两种 BIA 仪器在俄罗斯儿童生长、青春期发育和成熟研究（RCS）中男性的表现。
使用 Tanita BC-418MA（Tanita 公司，东京，日本）和 ABC-01 'Medas'（Medas 公司，莫斯科，俄罗斯）BIA 仪器进行配对 BIA 测量。使用 236 名 RCS 受试者的横断面数据（年龄 18-22 岁）进行 BIA 比较，并制定了两种测量电阻之间的转换公式；使用随访数据（n=96）验证了转换公式。
全身电阻高度相关（Spearman rho=0.95），但 Medas 仪器估计的脂肪量（FM）明显高于 Tanita 仪器（中位数差值 3.3 公斤，95%置信区间：2.9，3.6 公斤），FM 差值的一致性限（LoA）较大（-2.0，8.6 公斤）。获得了两种电阻（Res）之间的转换公式：Medas Res=0.882×Tanita Res+26.2（r=0.91，SEE=17.6 欧姆）。将转换公式应用于 Tanita 数据，并应用 Medas 评估算法后，“转换”后的 Tanita FM 估计值与 Medas 原始估计值非常匹配（中位数差值-0.1 公斤，95%置信区间：-0.3，0.2 公斤），FM 差值的一致性限较小（-2.3 至 2.1 公斤），表明在组水平上 ABC-01 'Medas'和 Tanita BC-418MA 数据具有潜在的可互换性。
我们的结果支持 BIA 仪器的交叉校准对于人群比较以及临床和流行病学研究中正确的数据解释的重要性。
