School of Public Health, University of Alberta, Edmonton, Alberta, Canada.
J Card Fail. 2010 Nov;16(11):867-72. doi: 10.1016/j.cardfail.2010.06.416. Epub 2010 Aug 4.
We examined the validity of leg-to-leg bioelectrical impedance analysis (BIA) and near-infrared interactance (NIR) to assess body composition in chronic heart failure (CHF) patients.
A total of 140 patients with CHF were enrolled in this cross-sectional study between June 2008 and July 2009. Dual energy x-ray absorptiometry (DEXA) served as the reference standard. A priori, desired precision levels were set at ± 3.5% body fat and ± 3.5 kg lean body mass. Mean age was 63, 74% were male, and 90% were Caucasian. BIA- and NIR-ascertained percent body fat and lean body mass were highly correlated to DEXA. Mean differences and limits of agreement for NIR were -0.3% ± 5.1% for percent body fat and 2.9 kg ± 4.3 kg for lean body mass. Mean difference and limits of agreement for BIA percent body fat was 0.8% ± 5.8%. BIA lean body mass showed poor agreement with DEXA because of variable limits of agreement across the range of measurement (Pitman's test P < .0001).
In patients with CHF, both NIR and BIA accurately measure body fat. However, both methods were imprecise. NIR overestimated lean body mass and BIA was not useful to assess this parameter. Further study is required, including examination of the utility of these field methods in serially assessing body composition.
我们研究了肢体生物电阻抗分析（BIA）和近红外相互作用（NIR）评估慢性心力衰竭（CHF）患者身体成分的有效性。
2008 年 6 月至 2009 年 7 月期间，共纳入 140 例 CHF 患者进行横断面研究。双能 X 射线吸收法（DEXA）作为参考标准。根据需要，设定了精度水平为±3.5%体脂和±3.5kg 瘦体重。平均年龄为 63 岁，74%为男性，90%为白种人。BIA 和 NIR 确定的体脂百分比和瘦体重与 DEXA 高度相关。NIR 的平均差异和一致性界限为体脂百分比-0.3%±5.1%，瘦体重 2.9kg±4.3kg。BIA 体脂百分比的平均差异和一致性界限为 0.8%±5.8%。BIA 瘦体重与 DEXA 一致性较差，因为测量范围内的一致性界限不同（Pitman 检验 P<0.0001）。
在 CHF 患者中，NIR 和 BIA 均能准确测量体脂。然而，这两种方法都不精确。NIR 高估了瘦体重，BIA 不能用于评估这一体重参数。需要进一步研究，包括检查这些现场方法在连续评估身体成分中的效用。
