Simons J P, Schols A M, Westerterp K R, ten Velde G P, Wouters E F
Department of Pulmonology, University of Limburg, Maastricht, Netherlands.
Am J Clin Nutr. 1995 Apr;61(4):741-5. doi: 10.1093/ajcn/61.4.741.
The applicability of bioelectrical impedance analysis (BIA) to predict total body water (TBW) was assessed in 16 underweight [< 95% of ideal body weight (IBW)] and 25 normal-weight (> 95% of IBW) cancer patients. Although height2/resistance (ht2/R) proved to be a strong single predictor of TBW measured by deuterium dilution in both groups (normal-weight patients: r2 = 0.85, SEE 2.16 L; underweight patients: r2 = 0.86, SEE 2.24 L), TBW would be significantly overestimated in the underweight group if the prediction formula developed in the normal-weight group was used [bias 1.67 L (5%), 95% CI 0.20-3.15 L]. A systematic overestimation of TBW in the underweight patients was also found when TBW was predicted in our two patient groups by several previously published BIA formulas developed in normal-weight individuals. We conclude therefore, that although a similar relationship is found between ht2/R and TBW in normal-weight and underweight cancer patients, single-frequency BIA overestimates TBW in underweight patients when prediction formulas are used that have been developed in normal-weight subjects.
在16名体重过轻[<理想体重（IBW）的95%]和25名体重正常（>IBW的95%）的癌症患者中评估了生物电阻抗分析（BIA）预测总体水（TBW）的适用性。尽管身高平方/电阻（ht2/R）在两组中均被证明是通过氘稀释测量的TBW的有力单一预测指标（体重正常的患者：r2 = 0.85，标准误2.16 L；体重过轻的患者：r2 = 0.86，标准误2.24 L），但如果使用在体重正常组中开发的预测公式，体重过轻组的TBW将被显著高估[偏差1.67 L（5%），95%置信区间0.20 - 3.15 L]。当通过先前在体重正常个体中开发的几个BIA公式在我们的两组患者中预测TBW时，也发现体重过轻的患者中TBW存在系统性高估。因此，我们得出结论，尽管在体重正常和体重过轻的癌症患者中发现ht2/R与TBW之间存在相似的关系，但当使用在体重正常受试者中开发的预测公式时，单频BIA会高估体重过轻患者的TBW。
