Chumlea W C, Guo S S
Department of Community Health, Wright State University School of Medicine, Dayton, OH 45335.
Nutr Rev. 1994 Apr;52(4):123-31. doi: 10.1111/j.1753-4887.1994.tb01404.x.
Single-frequency bioelectrical impedance analyzers used to assess body composition are being replaced by multiple-frequency analyzers. At low frequencies, the current flows primarily through extracellular fluids; at high frequencies, it completely penetrates all body tissues. Measures of bioelectrical impedance at multiple frequencies can differentiate total and extracellular fluid compartments in the body. This has considerable value for assessing clinical and nutritional status. Impedance measures at a single frequency contain only a small window of the available impedance spectrum information, which may explain the difficulty in discriminating among individuals. The impedance spectrum and its analysis may provide a much clearer picture of individual differences in body water and body composition. With increasing clinical uses of bioelectrical impedance in individuals and sample populations, the use of multiple-frequency impedance may help to elucidate differences that are not discernible with single-frequency impedance.
用于评估身体成分的单频生物电阻抗分析仪正被多频分析仪所取代。在低频时，电流主要流经细胞外液；在高频时，电流能完全穿透所有身体组织。多频生物电阻抗测量可区分体内的总体液和细胞外液区室。这对于评估临床和营养状况具有重要价值。单频阻抗测量仅包含可用阻抗谱信息的一小部分窗口，这可能解释了区分个体的困难。阻抗谱及其分析可能会更清晰地呈现个体在身体水分和身体成分方面的差异。随着生物电阻抗在个体和样本群体中的临床应用不断增加，使用多频阻抗可能有助于阐明单频阻抗无法辨别的差异。
