seca gmbh & co. kg, Hammer Steindamm 3 - 25, 22089 Hamburg, Germany.
Institut für Humanernährung und Lebensmittelkunde, Christian-Albrechts-Universität Kiel, Düsternbrooker Weg 17, 24105 Kiel, Germany.
Med Eng Phys. 2020 Oct;84:10-15. doi: 10.1016/j.medengphy.2020.07.021. Epub 2020 Jul 30.
Phase angle (PhA) obtained by bioelectrical impedance analysis is a well-established predictor of malnutrition that reflects the amount and quality of soft tissue. However, PhA results may depend on configurations of the measurement that differ between devices. The aim was to analyze differences between devices for supine and standing measurements.
In a cross-sectional study, differences in PhA were analyzed comparing supine vs. standing positions, metal vs. adhesive electrodes and the right vs. left side of the body in 302 multi-ethnic adults (18-65y) and 1298 Mexican children and adolescents (4-20y).
PhA was higher in supine than in standing position (from 0.71°±0.22° in children to 0.97°±0.25° in adults; all p < 0.001) with approximately fifty percent of observed differences explained by electrode placement. PhA differences increased with increasing PhA (r = 0.419) and decreased with age (r = -0.346) in adults, but increased with PhA (r = 0.677), age (r = 0.752) and height (r = 0.737) in children (all p <0.001). In adults, PhA was higher on the right side of the body (standing 0.18°±0.17°; supine 0.36°±0.33°; p <0.001).
Phase angle results are influenced by posture and electrode placement. Measurement configuration must be considered when phase angle values are compared between different devices or with literature values.
生物电阻抗分析得出的相位角（PhA）是营养不良的可靠预测指标，反映了软组织的数量和质量。然而，PhA 的结果可能取决于不同设备之间测量的配置不同。本研究旨在分析仰卧和站立测量时设备之间的差异。
在一项横断面研究中，我们比较了 302 名多民族成年人（18-65 岁）和 1298 名墨西哥儿童和青少年（4-20 岁）仰卧位与站立位、金属电极与粘贴电极以及身体右侧与左侧之间的 PhA 差异。
仰卧位时 PhA 高于站立位（儿童为 0.71°±0.22°，成人为 0.97°±0.25°；所有 p<0.001），观察到的差异约有一半是由电极放置位置引起的。在成年人中，PhA 差异随着 PhA（r=0.419）的增加而增加，随着年龄（r=-0.346）的增加而减小，但随着 PhA（r=0.677）、年龄（r=0.752）和身高（r=0.737）的增加而增加在儿童中（均 p<0.001）。在成年人中，身体右侧的 PhA 较高（站立时为 0.18°±0.17°；仰卧时为 0.36°±0.33°；p<0.001）。
相位角结果受姿势和电极放置位置的影响。当在不同设备或与文献值之间比较相位角值时，必须考虑测量配置。
