Goldfield G S, Cloutier P, Mallory R, Prud'homme D, Parker T, Doucet E
Mental Health Research, Children's Hospital of Eastern Ontario Research Institute, Ottawa, Ontario, Canada.
J Sports Med Phys Fitness. 2006 Sep;46(3):447-53.
The aim of this study was to evaluate the validity of foot-to-foot bioelectrical impedance analysis (FF-BIA) in the measurement of body composition in overweight and obese children and their parents by comparison to dual-energy X-ray absorptiometry (DXA).
Seventeen, 7-12 year old overweight and obese children (6 boys, 11 girls) and 17 parents (5 fathers, 12 mothers) were evaluated for body composition with FF-BIA and DXA. Measures of percent body fat (PBF), fat mass (FM) and fat free mass (FFM) derived from FF-BIA and DXA were compared. Measures of validity were determined by Pearson correlations between FF-BIA and DXA, paired t-tests to assess mean differences, as well as biases and limits of agreement using the Bland Altman tests.
FF-BIA produced estimates of body composition that were highly correlated with DXA in overweight and obese children and parents. For children, the correlations for PBF, FM, and FFM were 0.85, 0.97, and 0.94, respectively. For parents, the correlations for PBF, FM, and FFM were 0.92, 0.97, and 0.91, respectively. However, mean differences between FF-BIA and DXA were significant in children but not in parents. Bland-Altman tests of agreement showed moderate to large within-subject differences in body composition variables between FF-BIA and DXA.
FF-BIA is strongly related to DXA in the measurement of body composition in both overweight and obese preadolescent children and parents, but the two measures may not be used interchangeably. Although FF-BIA may lack the precision to assess small changes in body composition in overweight and obese individuals, it is appropriate for epidemiological use.
本研究旨在通过与双能X线吸收法（DXA）比较，评估足对足生物电阻抗分析（FF-BIA）在测量超重和肥胖儿童及其父母身体成分方面的有效性。
对17名7至12岁的超重和肥胖儿童（6名男孩，11名女孩）以及17名父母（5名父亲，12名母亲）进行FF-BIA和DXA身体成分评估。比较了由FF-BIA和DXA得出的体脂百分比（PBF）、脂肪量（FM）和去脂体重（FFM）测量值。通过FF-BIA与DXA之间的Pearson相关性、评估平均差异的配对t检验以及使用Bland Altman检验的偏差和一致性界限来确定有效性指标。
FF-BIA得出的身体成分估计值与超重和肥胖儿童及其父母的DXA高度相关。对于儿童，PBF、FM和FFM的相关性分别为0.85、0.97和0.94。对于父母，PBF、FM和FFM的相关性分别为0.92、0.97和0.91。然而，FF-BIA与DXA之间的平均差异在儿童中显著，但在父母中不显著。Bland-Altman一致性检验显示，FF-BIA和DXA之间身体成分变量的受试者内差异为中度至高度。
在测量超重和肥胖的青春期前儿童及其父母的身体成分时，FF-BIA与DXA密切相关，但这两种测量方法可能不能互换使用。虽然FF-BIA可能缺乏评估超重和肥胖个体身体成分微小变化的精度，但它适用于流行病学用途。
