US Military-Baylor University Graduate Program in Nutrition, Walter Reed National Military Medical Center, Bethesda, MD.
Military Advanced Training Center, Walter Reed Army Medical Center, Washington, DC.
J Acad Nutr Diet. 2021 Jul;121(7):1327-1334. doi: 10.1016/j.jand.2021.02.009. Epub 2021 Mar 17.
The Department of Defense circumference method (CM) is used to estimate percent body fat (%BF) in evaluation of health, physical fitness, appearance, and military readiness; however, the CM has not been validated in individuals with lower limb loss.
To evaluate the agreement between CM and dual-energy X-ray absorptiometry (DXA) for measuring %BF in individuals with lower limb loss.
This study is part of a larger cross-sectional comparison study, and this analysis was included as a secondary objective. Two methods of measuring %BF included CM and DXA, with DXA as the reference standard for this study.
PARTICIPANTS/SETTING: This study was conducted at Walter Reed Army Medical Center. Data were collected from summer 2010 to summer 2011. One hundred individuals, 50 with and 50 without lower limb loss, were screened for this study; three individuals with limb loss and two without limb loss had incomplete data, and one individual (female, without limb loss) lacked a comparison participant. All participants were recruited from a military medical center, and data were collected in a clinic research laboratory.
Measurements of %BF were compared between methods for each group.
Measurements of %BF were compared using paired t-tests and intraclass correlation coefficient. Agreement and bias were assessed with Bland-Altman analysis. Receiver operating characteristic analysis was used to determine the diagnostic accuracy of the CM to identify participants with %BF levels in the obese category (≥25%).
A statistically significant difference was found between %BF methods in the group with limb loss (1.7%; P = 0.001) and the group without limb loss (1.4%; P = 0.005), with DXA consistently higher than CM. However, the intraclass correlation coefficient estimates for the agreement between %BF by CM and DXA were 0.848 (95% confidence interval [CI]: 0.683-0.922; P < 0.001) and 0.828 (CI: 0.679-0.906; P < 0.001), for the groups with and without limb loss, respectively, suggesting that CM has good to near excellent agreement with DXA for estimating %BF in these groups. Receiver operating characteristic analysis indicated that the area under the curve supported predictive ability to detect obesity-based %BF in males with and without limb loss.
Although a statistically significant difference was found between methods for individuals with limb loss, there was also good agreement between the methods, suggesting that CM may be a useful tool for estimating %BF in individuals with lower limb loss. The CM may be a useful and field expedient method for assessing %BF in a clinical setting when DXA is not available.
国防部周长法（CM）用于评估健康、体能、外貌和军事准备状态下的体脂百分比（%BF）；然而，CM 尚未在下肢截肢者中得到验证。
评估 CM 与双能 X 射线吸收法（DXA）在测量下肢截肢者 %BF 中的一致性。
本研究是一项较大的横截面比较研究的一部分，本分析作为次要目标纳入。两种测量 %BF 的方法包括 CM 和 DXA，DXA 为本研究的参考标准。
参与者/设置：本研究在沃尔特·里德陆军医疗中心进行。数据收集于 2010 年夏季至 2011 年夏季。本研究共筛选了 100 名参与者，其中 50 名有下肢截肢，50 名无下肢截肢；3 名下肢截肢者和 2 名无下肢截肢者的数据不完整，1 名（女性，无下肢截肢）缺乏比较参与者。所有参与者均从军事医疗中心招募，并在诊所研究实验室收集数据。
比较两种方法在每组中的 %BF 测量值。
使用配对 t 检验和组内相关系数比较 %BF 测量值。通过 Bland-Altman 分析评估一致性和偏差。使用受试者工作特征分析确定 CM 识别 %BF 处于肥胖类别（≥25%）的参与者的诊断准确性。
在有下肢截肢的组（1.7%；P=0.001）和无下肢截肢的组（1.4%；P=0.005）中，CM 与 DXA 之间的 %BF 方法存在统计学显著差异，DXA 始终高于 CM。然而，CM 和 DXA 测量的 %BF 之间的组内相关系数估计值分别为 0.848（95%置信区间[CI]：0.683-0.922；P<0.001）和 0.828（CI：0.679-0.906；P<0.001），表明 CM 对于估计这些组中的 %BF 与 DXA 具有良好到近乎优异的一致性。受试者工作特征分析表明，曲线下面积支持在有和无下肢截肢的男性中检测基于肥胖的 %BF 的预测能力。
尽管在有下肢截肢的个体中，方法之间存在统计学显著差异，但方法之间也存在良好的一致性，这表明 CM 可能是一种有用的工具，可用于估计下肢截肢者的 %BF。当无法获得 DXA 时，CM 可能是一种有用且便于在临床环境中评估 %BF 的方法。
