Department of Family Medicine, Hallym University Sacred Heart Hospital, Anyang, Korea.
Department of Pediatrics, Seoul National University Bundang Hospital, Seongnam, Korea.
Scand J Med Sci Sports. 2018 Oct;28(10):2207-2215. doi: 10.1111/sms.13248. Epub 2018 Jul 10.
This study aimed to validate body composition analysis using bioelectrical impedance analysis (BIA) against dual-energy X-ray absorptiometry (DXA) in children with obesity and to compare agreement between BIA and DXA according to their degree of obesity. Three hundred and sixteen children aged 6-17 years participated in the Intervention for Childhood and Adolescents Obesity via Activity and Nutrition study. We divided participants by body mass index (BMI) percentile (group 1: mild to moderate obesity; group 2: severe obesity) and compared body composition variables, eg, percentage of body fat (%BF), fat mass (FM), and fat-free mass (FFM) using BIA and DXA. The %BF and FM of BIA were significantly lower (-1.8% and -0.8 kg, respectively), and the FFM of BIA was significantly higher (1.4 kg) than those of DXA. There were significant negative relationships between the absolute value of differences from BIA and DXA and BMI z-scores in %BF, FM, and FFM (regression coefficient [β]: -1.39, 95% confidence interval [CI]: -1.81 to -0.97; β: -0.34, 95%CI: -0.61 to -0.06; β: -0.73, 95%CI: -1.03 to -0.44, respectively). The gap of body compositions between BIA and DXA decreased as participants became more obese, and the differences of FM in boys with severe obesity and the differences of %BF and FFM in girls with severe obesity were much less than those in children with mild to moderate obesity. In conclusion, the agreement between DXA and BIA was better for children with severe obesity than for children with mild to moderate obesity.
本研究旨在验证生物电阻抗分析（BIA）在肥胖儿童中用于身体成分分析的有效性，并根据肥胖程度比较 BIA 和 DXA 的一致性。共有 316 名 6-17 岁的儿童参与了通过活动和营养干预儿童和青少年肥胖的研究。我们根据体重指数（BMI）百分位（第 1 组：轻度至中度肥胖；第 2 组：重度肥胖）将参与者分组，并比较 BIA 和 DXA 测量的身体成分变量，例如体脂百分比（%BF）、脂肪量（FM）和去脂体重（FFM）。BIA 的 %BF 和 FM 显著较低（分别为-1.8%和-0.8 公斤），而 BIA 的 FFM 显著较高（1.4 公斤）。BIA 和 DXA 之间的差异绝对值与 %BF、FM 和 FFM 的 BMI z 分数呈显著负相关（回归系数[β]：-1.39，95%置信区间[CI]：-1.81 至-0.97；β：-0.34，95%CI：-0.61 至-0.06；β：-0.73，95%CI：-1.03 至-0.44）。随着参与者肥胖程度的增加，BIA 和 DXA 之间的身体成分差距减小，重度肥胖男孩的 FM 差异以及重度肥胖女孩的 %BF 和 FFM 差异均小于轻度至中度肥胖儿童。总之，与轻度至中度肥胖儿童相比，BIA 和 DXA 的一致性在重度肥胖儿童中更好。
