Bedogni G, Malavolti M, Severi S, Poli M, Mussi C, Fantuzzi A L, Battistini N
Human Nutrition Chair, Faculty of Medicine and Surgery, University of Modena and Reggio Emilia, Modena, Italy.
Eur J Clin Nutr. 2002 Nov;56(11):1143-8. doi: 10.1038/sj.ejcn.1601466.
To establish the accuracy of an eight-polar tactile-electrode impedance method in the assessment of total body water (TBW).
Transversal study.
University department.
Fifty healthy subjects (25 men and 25 women) with a mean (s.d.) age of 40 (12) y.
TBW measured by deuterium oxide dilution; resistance (R) of arms, trunk and legs measured at frequencies of 5, 50, 250 and 500 kHz with an eight-polar tactile-electrode impedance-meter (InBody 3.0, Biospace, Seoul, Korea).
An algorithm for the prediction of TBW from the whole-body resistance index at 500 kHz (height (2)/R(500) where R is the sum of the segmental resistances of arms, trunk and legs) was developed in a randomly chosen subsample of 35 subjects. This algorithm had an adjusted coefficient of determination (r2(adj)) of 0.81 (P<0.0001) and a root mean square error (RMSE) of 3.6 l (9%). Cross-validation of the predictive algorithm in the remaining 15 subjects gave an r2(adj) of 0.87 (P<0.0001) and an RMSE of 3.0 l (8%). The precision of eight-polar BIA, determined by measuring R three times a day for five consecutive days in a fasting subject, was < or =2.8% for all segments and frequencies.
Eight-polar BIA is a precise method that offers accurate estimates of TBW in healthy subjects. This promising method should undergo further studies of precision and its accuracy in assessing extracellular water and appendicular body composition should be determined.
Modena and Reggio Emilia University.
确定一种八极触觉电极阻抗法评估全身水（TBW）的准确性。
横向研究。
大学科室。
50名健康受试者（25名男性和25名女性），平均（标准差）年龄为40（12）岁。
通过氧化氘稀释法测量TBW；使用八极触觉电极阻抗仪（InBody 3.0，韩国首尔Biospace公司）在5、50、250和500 kHz频率下测量手臂、躯干和腿部的电阻（R）。
在随机选择的35名受试者子样本中，开发了一种根据500 kHz时的全身电阻指数预测TBW的算法（身高（2）/R（500），其中R是手臂、躯干和腿部节段电阻之和）。该算法的调整决定系数（r2（adj））为0.81（P<0.0001），均方根误差（RMSE）为3.6升（9%）。在其余15名受试者中对预测算法进行交叉验证，得到r2（adj）为0.87（P<0.0001），RMSE为3.0升（8%）。通过在一名禁食受试者中连续五天每天测量R三次来确定八极生物电阻抗分析（BIA）的精密度，所有节段和频率的精密度均≤2.8%。
八极BIA是一种精确的方法，可准确估计健康受试者的TBW。这种有前景的方法应进一步研究其精密度，并确定其评估细胞外液和附属身体成分的准确性。
摩德纳和雷焦艾米利亚大学。
