Experimental and Clinical Research Center, a joint cooperation between Charité Universitätsmedizin and Max-Delbrück Center for Molecular Medicine, Charité Universitätsmedizin, Berlin, Germany.
Eur J Clin Nutr. 2012 Sep;66(9):994-7. doi: 10.1038/ejcn.2012.96. Epub 2012 Aug 1.
BACKGROUND/OBJECTIVES: In this study, we aimed to validate the accuracy of single-frequency bioelectrical impedance analysis (SF-BIA) at 50 kHz to assess total body water (TBW) against the reference technique deuterium dilution (D(2)O) and to explore if the simple clinical parameters extracellular fluid (ECF) composition and body shape explain individual differences between D(2)O and SF-BIA (Diff(BIA-D(2)O)).
SUBJECTS/METHODS: We assessed TBW with D(2)O and SF-BIA in 26 women and 26 men without known disease or anomalous body shapes. In addition, we measured body shape with anthropometry and ECF composition (osmolality, albumin, glucose, urea, creatinine, sodium and potassium).
On group average, SF-BIA to predict TBW agreed well with D(2)O (SF-BIA, 39.8 ± 10.1 l; D(2)O, 40.4 ± 10.2 l; and Diff(BIA-D(2)O) -0.7 l). In four individuals ('outliers'; 15% of the study population), Diff(BIA-D(2)O) was high (-6.8 to +3.8 l). Diff(BIA-D(2)O) was associated with individual variations in body shape rather than ECF composition. Using gender-specific analysis, we found that individual variability of waist circumference in men and arm length in women significantly contributed to Diff(BIA-D(2)O). When removing the four 'outliers', these associations were lost.
In the majority of our sample, BIA agreed well with D(2)O. Adjusting for individual variability in body shape by anthropometrical assessment could possibly improve the accuracy of SF-BIA for individuals who deviate from mean values with respect to body shape. However, further studies with higher subject numbers are needed to confirm our findings.
背景/目的：在这项研究中，我们旨在验证 50 kHz 单频生物阻抗分析（SF-BIA）评估总体水（TBW）的准确性，以参考技术氘稀释（D(2)O），并探索简单的临床参数细胞外液（ECF）组成和体型是否可以解释 D(2)O 和 SF-BIA 之间的个体差异（Diff(BIA-D(2)O)）。
受试者/方法：我们在 26 名女性和 26 名男性中评估了 D(2)O 和 SF-BIA 的 TBW，这些受试者没有已知的疾病或异常体型。此外，我们还通过人体测量法和 ECF 组成（渗透压、白蛋白、葡萄糖、尿素、肌酐、钠和钾）来测量体型。
在组平均水平上，SF-BIA 预测 TBW 与 D(2)O 吻合良好（SF-BIA，39.8 ± 10.1 l；D(2)O，40.4 ± 10.2 l；Diff(BIA-D(2)O) -0.7 l）。在 4 个人（“离群值”；研究人群的 15%）中，Diff(BIA-D(2)O) 较高（-6.8 至+3.8 l）。Diff(BIA-D(2)O) 与体型的个体差异有关，而与 ECF 组成无关。使用性别特异性分析，我们发现男性腰围和女性臂长的个体变异性显著影响了 Diff(BIA-D(2)O)。当去除这 4 个“离群值”时，这些关联就消失了。
在我们的样本中，大多数情况下 BIA 与 D(2)O 吻合良好。通过人体测量评估来调整体型的个体差异，可能会提高 SF-BIA 对偏离体型平均值的个体的准确性。然而，需要进一步进行更多的研究以确认我们的发现。
