Ecuaciones para la estimación del agua corporal total por el método de análisis de impedancia bioeléctrica a 50 kHz

Introduction : The water maintains a normal range in apparently healthy people, which changes with the existence of diverse diseases. Objective: To know how the values of total body water estimated by Kushner, Deurenberg and Heitman equations of total body water, differ regarding those obtained clinically by the method of bioelectric impedance at 50 kHz. Methods : A descriptive and cross-sectional study was carried out, from April to December, 2018, in 62 individuals: 31 apparently healthy adults and 31 children and adolescents with different diseases, admitted to “Dr. Antonio Maria Beguez Cesar” Southern Teaching Children Hospital in Santiago de Cuba (24 in the Miscellaneous Service and 7 in Oncopediatrics Service). The total body water and the bioelectric parameters were considered with the analyzer of bioelectric impedance Bodystat ® 1500-MDD, at 50 kHz, for the right ipsilateral tetrapolar method. The approach of Bland-Altman was used, for 95% of confidence in order to know if Kushner, Deurenberg and Heitman equations could substitute the reference equation. Results : Kushner and Deurenberg equations of total body water didn't show significant differences regarding the reference equation, while Heitman equation presented significant differences related to the rest of the equations. The Bland-Altman method demonstrated that the equation of Kushner has higher concordance with the reference equation. Conclusions : Kushner equation has the highest accuracy for the estimate of total body water in healthy people and in those affected by diseases.