Laboratory of the Metabolic Adaptations to Exercise under Physiological and Pathological Conditions (AME2P), UE3533, Clermont Auvergne University, 63170 Aubiere Cedex, France; Auvergne Research Center for Human Nutrition (CRNH), 63000 Clermont-Ferrand, France.
UGECAM Nutrition Obesity Ambulatory Hostipal, Clermont-Ferrand, France.
Nutr Res. 2018 Jun;54:60-68. doi: 10.1016/j.nutres.2018.04.001. Epub 2018 Apr 6.
The aim of the present study was to assess the sensitivity of bio-impedance (BIA) in tracking body composition changes in adolescents with various degrees of obesity. We hypothesized that while BIA provides a reliable measure of body composition, its accuracy decreases with increasing obesity and its ability to track changes might be reduced with higher degree of body weight and body composition. Whole-body and segmental body composition were assessed by bio-impedance analysis (BIA-Tanita MC-780) and dual x-ray absorptiometry (DXA, Hologic) among 196 obese adolescents (Tanner stage 3-5) aged 14 ± 0.9 years old, before and after a 3-month weight loss program. Except for the measurement of FFM (kg) (r = 0.03; P = .721; ρ = 0.107; P = .246), the percentage of variation between M0 and M3 for FM% (r = 0.41, P < .001; ρ = 0.534; P < .001) and FMkg (r = 0.64 P < .001; ρ = 0.572; P < .001) are significantly correlated and show significant concordance between DXA and BIA. FMkg and FM% changes between M0 and M3 are similarly tracked by DXA and BIA whatever the initial degree of obesity (based on initial weight, BMI, FM% and FFMkg tertiles). The higher the degree of changes and the higher are the differences between the two devices in measuring FM% and FMkg changes. We found inconsistent and low correlations and concordances between the two devices when tracking FM% changes whatever the degree of weight and FM (kg and %) variations. The accuracy of body composition assessment using BIA decreases with increasing obesity, and its reliability to track changes is reduced with high initial or variations of body weight, FM, FFM and BMI.
本研究旨在评估生物阻抗（BIA）在跟踪不同程度肥胖青少年身体成分变化方面的敏感性。我们假设，虽然 BIA 提供了一种可靠的身体成分测量方法，但随着肥胖程度的增加，其准确性会降低，并且随着体重和身体成分的增加，其跟踪变化的能力可能会降低。在一项为期 3 个月的减肥计划前后，我们使用生物阻抗分析（BIA-Tanita MC-780）和双能 X 射线吸收法（DXA，Hologic）评估了 196 名肥胖青少年（Tanner 阶段 3-5）的全身和节段性身体成分，这些青少年的年龄为 14±0.9 岁。除了去脂体重（kg）的测量值（r=0.03；P=0.721；ρ=0.107；P=0.246）外，M0 到 M3 期间 FM%（r=0.41，P<0.001；ρ=0.534；P<0.001）和 FMkg（r=0.64，P<0.001；ρ=0.572；P<0.001）的变化百分比显著相关，并且 DXA 和 BIA 之间具有显著的一致性。无论初始肥胖程度如何（基于初始体重、BMI、FM%和 FFMkg 三分位数），DXA 和 BIA 都能很好地跟踪 M0 到 M3 期间 FMkg 和 FM%的变化。变化幅度越大，两个设备之间在测量 FM%和 FMkg 变化方面的差异越大。无论体重和 FM（kg 和%）变化的程度如何，我们发现两个设备之间的 FM%变化的相关性和一致性都不一致且较低。随着肥胖程度的增加，使用 BIA 评估身体成分的准确性会降低，其跟踪变化的可靠性也会随着初始体重、FM、FFM 和 BMI 的变化而降低。
