Graduate Institute of Biostatistics, College of Public Health, China Medical University, Taichung, Taiwan.
PLoS One. 2013;8(4):e58272. doi: 10.1371/journal.pone.0058272. Epub 2013 Apr 1.
The current study aimed to compare the estimates of body fat percentage (%BF) by performing bioelectrical impedance analysis (BIA) and dual energy X-ray absorptiometry (DXA) in a sample of obese or overweight Chinese adults who participated in a weight-loss randomized control trial stratified by gender to determine whether or not BIA is a valid measurement tool. Among 189 adults [73 males, 116 females; age = 41 to 74 years; mean body mass index (BMI) = 27.3 kg/m(2)], assessments of %BF at the baseline and six months from the baseline were conducted by performing BIA and DXA. Bland-Altman analyses and multiple regression analyses were used to assess the relationships between %BFBIA and %BFDXA. Compared with DXA, BIA underestimated %BF [in males: 4.6, -2.4 to 11.7 (mean biases, 95% limit of agreement) at the baseline, 1.4, -7.4 to 10.2 at the endpoint, and 3.2, -4.8 to 11.3 in changes; in females: 5.1, -2.4 to 12.7; 2.2, -6.1 to 10.4; and 3.0, -4.8 to 10.7, respectively]. For males and females, %BFDXA proved to be a significant predictor of the difference between DXA and BIA at the baseline, the endpoint, and in changes when BMI and age were considered (in males: p<0.01 and R (2) = 23.1%, 24.1%, 20.7%, respectively; for females: p<0.001 and R (2) = 40.4%, 48.8%, 25.4%, respectively). The current study suggests that BIA provides a relatively accurate prediction of %BF in individuals with normal weight, overweight, or obesity after the end of weight-loss program, but less accurate prediction of %BF in obese individuals at baseline or weight change during the weight-loss intervention program.
本研究旨在通过对参加减肥随机对照试验的肥胖或超重中国成年人样本进行生物电阻抗分析（BIA）和双能 X 射线吸收法（DXA）测量体脂肪百分比（%BF），比较两种方法的估计值，以确定 BIA 是否为有效的测量工具。该研究共纳入 189 名成年人[73 名男性，116 名女性；年龄 41-74 岁；平均体重指数（BMI）27.3kg/m(2)]，基线和基线后 6 个月时通过 BIA 和 DXA 测量 %BF。采用 Bland-Altman 分析和多元回归分析评估 %BFBIA 与 %BFDXA 之间的关系。与 DXA 相比，BIA 低估了 %BF[男性：基线时为 4.6，-2.4 至 11.7（平均偏差，95%限差），终点时为 1.4，-7.4 至 10.2，变化时为 3.2，-4.8 至 11.3；女性：分别为 5.1，-2.4 至 12.7；2.2，-6.1 至 10.4；3.0，-4.8 至 10.7]。对于男性和女性，当考虑 BMI 和年龄时，%BFDXA 被证明是基线、终点和变化时 DXA 与 BIA 之间差异的显著预测因子（男性：p<0.01，R (2) = 23.1%、24.1%、20.7%；女性：p<0.001，R (2) = 40.4%、48.8%、25.4%）。本研究表明，在减肥计划结束后，BIA 可以相对准确地预测体重正常、超重或肥胖个体的 %BF，但在减肥干预计划的基线或体重变化时，对肥胖个体的 %BF 预测准确性较低。
