Bioelectric impedance spectroscopy underestimates fat-free mass compared to dual energy X-ray absorptiometry in incurable cancer patients
Bioelectric impedance spectroscopy underestimates fat-free mass compared to dual energy X-ray absorptiometry in incurable cancer patients
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DOI：
10.1038/ejcn.2008.35
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发表时间：
2009-06-01
影响因子：
4.7
通讯作者：
Bosaeus, I. G.
中科院分区：
文献类型：
--
作者：
Ellegard, L. H.;Ahlen, M.;Bosaeus, I. G.
背景/目标：体重减轻常见于晚期癌症。生物电阻抗光谱 (BIS) 是一种估算身体成分的便捷方法。我们在一项前瞻性比较研究中检验了与双能 X 射线吸收测定法 (DXA) 相比，BIS 是否能够准确估计癌症患者的无脂体重 (FFM)。 对象/方法：该研究基于大学医院门诊诊所连续 132 名患有实体瘤的无法治愈癌症患者。 DXA 和 BIS 的 FFM 与标准方程和修订方程的比较。 Bland-Altman 图、t 检验和线性回归分析用于评估方法之间的一致性和差异。结果：与 DXA 相比，BIS 显着低估了平均 FFM，为 7.6 +/- 4.7 kg（P < 0.001）。偏差与体重减轻百分比（r = 0.32）、C反应蛋白测量的全身炎症（r = 0.29）、低胰岛素样生长因子-1评估的营养不良（r = -0.23）显着相关，并且与 DXA 估计的体脂百分比（P = -0.61）和体重指数（BMI；r = -0.30）成反比。考虑到 BMI 的修订版 BIS 方程显着减少了偏差，但个体差异仍然很大。结论：与 DXA 相比，标准方程的 BIS 在癌症患者中严重低估了 FFM。这种偏差与体重减轻、营养不良和全身炎症有关。修改后的方程改进了 FFM 估计，但个体差异较大。因此，使用标准方程的 BIS 不适合评估恶病质、炎症和营养不良患者的 FFM。欧洲临床营养杂志 (2009) 63, 794-801； doi：10.1038/ejcn.2008.35； 2008 年 5 月 14 日在线发布
Background/Objectives: Weight loss is frequently seen in advanced cancer. Bioelectrical impedance spectroscopy (BIS) is a convenient method for estimating body composition. We examined in a prospective, comparative study if BIS could accurately estimate fat-free mass (FFM) in cancer patients compared to dual-energy X-ray absorptiometry (DXA).Subjects/Methods: The study was based on 132 consecutive incurable cancer patients with solid tumours in a University hospital outpatient clinic. Comparison of FFM from DXA and BIS with standard and revised equations. Bland-Altman plots, t-tests and linear regression analysis were used to evaluate agreement and differences between methods.Results: BIS significantly underestimated mean FFM with 7.6 +/- 4.7 kg compared to DXA (P < 0.001). Bias was significantly correlated to % weight loss (r = 0.32), systemic inflammation as measured by C-reactive protein (r = 0.29),malnutrition as assessed by low insulin-like growth factor-1 (r = -0.23) and inversely to the per cent body fat estimated by DXA (P = -0.61) and body mass index (BMI; r = -0.30). Revised BIS equations taking BMI into account reduced bias significantly but still with great individual variation.Conclusions: BIS by standard equations grossly underestimates FFM compared to DXA in cancer patients. This bias is related to weight loss, malnutrition and systemic inflammation. Revised equations improved FFM estimates, but with large individual variation. Thus, BIS with standard equations is not suitable to estimate FFM in patients with cachexia, inflammation and malnutrition. European Journal of Clinical Nutrition (2009) 63, 794-801; doi:10.1038/ejcn.2008.35; published online 14 May 2008