Sergi G, Lupoli L, Enzi G, Volpato S, Perissinotto E, Bertani R, Inelmen E M, Bonometto P, Busetto L, Berton A, Coin A
Department of Medical and Surgical Sciences, Division of Geriatrics, Ospedale Giustiniani (2 piano), University of Padua, via Giustiniani 2, IT-35100 Padua, Italy.
Scand J Clin Lab Invest. 2006;66(1):19-30. doi: 10.1080/00365510500402158.
To investigate the reliability of bioelectrical impedance analysis (BIA) in estimating total body water (TBW) and extracellular water (ECW) in elderly patients suffering from congestive heart failure (CHF).
In 72 elderly subjects, 34 with CHF (aged 83.9+/-6.9 years) and 38 healthy controls (78.7+/-7.5 years), TBW and ECW values were assessed using dilution methods, and bioelectrical variables were measured using single frequency BIA (SF-BIA) at 1 and 50 kHz, and bioelectrical spectroscopy (BIS).
In CHF patients, Ht(2)/R(1) correlated weakly with TBW (r = 0.56) and ECW (0.47). In both healthy controls and CHF patients, TBW correlated strongly with Ht(2)/R(50), Ht(2)/R(0), Ht(2)/R(8) and Ht(2)/Zc. Using multiple regression analysis and the Bland-Altmann approach, SF-BIA at 50 kHz and BIS proved similar in predicting TBW for both the explained variance (R(2)~0.89) and the limits of agreement. In all subjects, ECW was estimated best by including height, weight and Ht(2)/R(0 )(R(2) 0.75) or Ht(2)/Zc (R(2) 0.77) in multivariate models, while SF-BIA at 50 kHz did not explain more than 71 % of ECW variability. The SEE % was nonetheless about twice the SEE % for estimating TBW.
SF-BIA at 1 kHz is unreliable in predicting body fluids in elderly people with CHF. SF-BIA at 50 kHz and BIS are useful for estimating TBW in healthy elderly people and in cases of water imbalance, but both methods are less reliable in estimating ECW, particularly in conditions of fluid overload.
探讨生物电阻抗分析（BIA）在评估老年充血性心力衰竭（CHF）患者全身水（TBW）和细胞外液（ECW）中的可靠性。
选取72例老年受试者，其中34例CHF患者（年龄83.9±6.9岁）和38例健康对照者（78.7±7.5岁），采用稀释法评估TBW和ECW值，并使用单频BIA（SF-BIA）在1kHz和50kHz频率下以及生物电阻抗光谱法（BIS）测量生物电变量。
在CHF患者中，Ht(2)/R(1)与TBW（r = ０.56）和ECW（0.47）的相关性较弱。在健康对照者和CHF患者中，TBW与Ht(2)/R(50)、Ht(2)/R(0)、Ht(2)/R(8)和Ht(2)/Zc均呈强相关。使用多元回归分析和Bland-Altmann方法，50kHz的SF-BIA和BIS在预测TBW的解释方差（R(2)~0.89）和一致性界限方面相似。在所有受试者中，通过在多变量模型中纳入身高、体重和Ht(2)/R(0)（R(2) 0.75）或Ht(2)/Zc（R(2) 0.77）能最佳地估计ECW，而50kHz的SF-BIA对ECW变异性的解释不超过71%。然而，估计ECW的SEE%约为估计TBW的SEE%的两倍。
1kHz的SF-BIA在预测老年CHF患者的体液方面不可靠。50kHz的SF-BIA和BIS可用于估计健康老年人和水失衡情况下的TBW，但两种方法在估计ECW方面可靠性较低，尤其是在液体超负荷的情况下。
