Institute of Preventive Medicine, Copenhagen University Hospital, Centre for Health and Society, Copenhagen, Denmark.
Diabetes Metab. 2011 Jun;37(3):222-9. doi: 10.1016/j.diabet.2010.10.007. Epub 2011 Jan 14.
We studied the accuracy of bioelectrical impedance analysis (BIA) to assess changes in body composition during moderate weight loss in obese subjects.
Estimates of changes in fat mass (FM) and fat-free mass (FFM) by BIA were compared with those by dual-energy X-ray absorptiometry (DXA) as the reference method during a 10-week standardized weight-loss intervention. In obese women (age: 20-50 years, mean BMI: 33.8 kg/m(2)) participating in a European multicentre trial (nutrient-gene interactions in human obesity [NUGENOB]), body composition was assessed by BIA (Bodystat QuadScan 4000) and DXA (Lunar DPX-IQ at two centres, Hologic QDR 2000 at another centre) at baseline (n=131) and at week 10 (n=105) after a mean weight loss of -5.7 kg.
At baseline, BIA significantly overestimated FFM and underestimated FM (by 1-3 kg on average) compared with DXA, and the limits of agreement were wide (mean ± 7-8.5 kg). For body-composition changes, although biases were generally non-significant, the limits of agreement were also wide (mean ± 3.7-4.6 kg). An FFM prediction equation for BIA data was developed in subjects scanned with Lunar instruments and cross-validated in an independent sample of 31 obese women undergoing similar weight loss. However, no major improvement in limits of agreement was found.
During moderate diet-induced weight loss, the use of BIA leads to estimates of changes in body composition at the individual level that can differ substantially from those assessed by DXA, indicating that BIA and DXA cannot be used interchangeably. However, BIA in this context may be used for assessing changes in body composition at group level.
我们研究了生物电阻抗分析（BIA）评估肥胖受试者适度减肥期间身体成分变化的准确性。
在为期 10 周的标准化减肥干预期间，通过 BIA 估计的脂肪量（FM）和去脂体重（FFM）变化与双能 X 射线吸收法（DXA）作为参考方法进行比较。在参与欧洲多中心试验（人类肥胖中的营养基因相互作用 [NUGENOB]）的肥胖女性（年龄：20-50 岁，平均 BMI：33.8kg/m2）中，通过 BIA（Bodystat QuadScan 4000）和 DXA（两个中心的 Lunar DPX-IQ，另一个中心的 Hologic QDR 2000）在基线（n=131）和平均体重减轻 5.7kg 后的第 10 周（n=105）评估身体成分。
在基线时，与 DXA 相比，BIA 显著高估了 FFM，低估了 FM（平均低 1-3kg），且一致性界限较宽（平均±7-8.5kg）。对于身体成分变化，尽管偏差通常无统计学意义，但一致性界限也较宽（平均±3.7-4.6kg）。在接受 Lunar 仪器扫描的受试者中开发了 BIA 数据的 FFM 预测方程，并在进行类似减肥的 31 名肥胖女性的独立样本中进行了交叉验证。然而，没有发现一致性界限有重大改善。
在适度的饮食诱导减肥期间，BIA 用于评估个体水平的身体成分变化的估计值与 DXA 评估的结果可能有很大差异，这表明 BIA 和 DXA 不能互换使用。但是，在这种情况下，BIA 可用于评估身体成分的变化。
