Analytic assessment of the various bioimpedance methods used to estimate body water

1998 ◽  
Vol 84 (5) ◽  
pp. 1801-1816 ◽  
Author(s):  
J. Matthie ◽  
B. Zarowitz ◽  
A. De Lorenzo ◽  
A. Andreoli ◽  
K. Katzarski ◽  
...  

Knowledge of patient fluid distribution would be useful clinically. Both single-frequency (SF) and impedance modeling approaches are proposed. The high intercorrelation between body water compartments makes determining the best approach difficult. This study was conducted to evaluate the merits of an SF approach. Mathematical simulation was performed to determine the effect of tissue change on resistance and reactance. Dilution results were reanalyzed, and resistance and parallel reactance were used to predict the intracellular water for two groups. Results indicated that the amount of intracellular and extracellular water conduction at any SF can vary with tissue change, and reactance at any SF is affected by all tissue parameters. Modeling provided a good prediction of dilution intracellular and extracellular water, but an SF method did not. Intracellular, extracellular, and total body water were equally predicted at all frequencies by SF resistance and parallel reactance. Extracellular and intracellular water are best measured through modeling, because only at the zero and infinite frequencies are the results sensitive only to extracellular and intracellular water. At all other frequencies there are other effects.

2020 ◽  
Vol 35 (Supplement_3) ◽  
Author(s):  
Anna Matyjek ◽  
Aleksandra Rymarz ◽  
Stanisław Niemczyk

Abstract Background and Aims One of the major symptoms of severe nephrotic syndrome is fluid retention. Fluid overload can induce cardiovascular damage. NT-proBNP (N-terminal pro-brain natriuretic peptide) and hsTnT (high sensitivity troponin T) are well known markers of this disorder. The aim of the study was to evaluate the association between volumes of body water compartments and markers of cardiovascular damage in patients with severe nephrotic syndrome (SNS) defined as nephrotic range proteinuria and hypalbuminaemia ≤ 2.5 g/dl. Method 40 patients with SNS and eGFR >30 ml/min/1.73m2 formed the study group (SNSG) and 40 healthy volunteers without SNS matched according to age, sex, height, body mass and kidney function formed the control group (CG). In all participants serum creatinine, serum albumin concentration, daily proteinuria, hsTnT and NT-proBNP were measured. Body water compartments such as extracellular water (ECW), intracellular water (ICW), total body water (TBW), overhydration (OH) were assessed using Body Composition Monitor, Fresenius Medical Care. For statistical analysis Spearman’s correlation coefficients, chi2 or Mann-Whitney U tests were used (Statistica v 13.1). Results SNSG included 28 males (70%) and 12 females. Median age was 55 years (IQR 30-65), the mean daily proteinuria was 10.5 ±5.0 g. The characteristics of the study parameters in two groups are described in the table. Significantly higher hsTnT (18 vs 6 ng/l, p=0.0001) and NT-proBNP (294.8 vs 47.1 pg/ml, p=0.0003) levels were observed in the severe nephrotic syndrome group in comparison (SNSG) to CG. In SNSG extracellular water was significantly higher (20.9 ±5,2 vs 17.4 ±3.3 L, p=0.001) and intracellular water (ICW) was significantly lower (18.9 ±5.2 vs 21.4 ±4.8 L, p=0.034) in comparison to CG. Interestingly total body water (TBW) did not differ between the groups (39.8 ±8.6 vs 38.8 ±7.7 L, p=0.603). Also overhydration which is a derivative of ECW, was higher in SNSG (OH: 4.2 vs 0.3 L, p<0.0001) than in CG. Significant, positive correlation was observed between OH and NT-proBNP (R=0.56, p<0.0001) as well as hsTnT (R=0.60, p<0.0001). We did not observed significant correlation between ECW and NT-proBNP or hsTnT. Conclusion In the severe nephrotic syndrome group fluid retention was associated with the increase in ECW and the decrease in ICW whereas TBW was the same in both groups. Such constellation can indicate for intracellular underhydration which was not describe so far. Overhydration, which is a derivative of ECW, positively correlated with markers of cardiovascular damage and can be important for patients with resistant SNS and can influence their prognosis.


1997 ◽  
Vol 82 (3) ◽  
pp. 907-911 ◽  
Author(s):  
Wouter D. van Marken Lichtenbelt ◽  
Yvonne E. M. Snel ◽  
Robert-Jan M. Brummer ◽  
Hans P. F. Koppeschaar

Abstract GH has a strong influence on body composition. However, the effects of GH deficiency in adults on water compartments are not well understood. Therefore, extracellular water (ECW) and total body water were independently determined by deuterium and bromide dilution and by bioimpedance spectrometry in GH-deficient (GHD) adults and compared to those in controls, matched for age, sex, body weight, and height. The results show that the percent body fat was significantly (P < 0.05) higher, and total body water and intracellular water (ICW) were significantly lower in GHD adults for males, females, and both sexes combined. ECW was not significantly different between the two groups. ECW/ICW in GHD adults (0.42 ± 0.03) was significantly (P < 0.01) higher than that in controls (0.39 ± 0.02). There was a significant positive relation between the ECW/ICW ratio and the percent body fat. These results were confirmed by the bioimpedance spectrometry measurements.


PEDIATRICS ◽  
1962 ◽  
Vol 29 (6) ◽  
pp. 883-889
Author(s):  
Wesley M. Clapp ◽  
L. Joseph Butterfield ◽  
Donough O'Brien

Normal values for both total body water and extracellular water have been determined in 86 premature infants aged 1 to 90 days and weighing 940 to 2,435 gm, with use of the techniques of deuterium oxide and bromide dilution. Nine full-term infants aged 1 to 6 days and weighing 2,590 to 4,985 gm were similarly studied. Nine infants with the respiratory distress syndrome and eight infants of toxemic mothers studied in the first 24 hours of life showed no significant difference in their body water compartments in comparison to a control group of normal infants matched for age and weight. Seven infants of diabetic mothers studied in the first 24 hours of life showed a significant decrease in total body water, expressed as percentage of body weight, with a normal intracellular to extracellular water ratio. These data indirectly support other evidence that there is an increase in body fat in these infants at birth. See Table in the PDF file


PEDIATRICS ◽  
1961 ◽  
Vol 28 (2) ◽  
pp. 169-181
Author(s):  
B. Friis-Hansen

During growth of infants and children, certain characteristic changes are found. A rapid decrease of the relative volumes of total body water and of extracellular water occurs during the first year of life, followed by a smaller decrease of volume of extracellular water later in childhood. At the same time an increased heterogeneity of the extracellular water takes place. On the other hand, the volume of intracellular water increases a little during the first months of life and remains more or less constant from then on. Formulas and nomograms from which these body water compartments can be predicted are presented. Finally, data on the corresponding changes in the total body water and in body specific gravity are discussed.


1978 ◽  
Vol 45 (6) ◽  
pp. 999-1001 ◽  
Author(s):  
E. W. Colt ◽  
J. Wang ◽  
R. N. Pierson

Despite a 2.3% weight loss in 10 men who ran 10 miles, extracellular water (ECW) increased by 3.5%. Total body water (TBW) measured as tritium space increased by 2.4%, and intracellular water (ICW), inferred as the difference between TBW and ECW, increased by 1.8%. The increase in tritium space probably represents increased nonaqueous hydrogen exchange in the postexercise period ond casts doubt on the validity of TBW and ICW when measured immediately after exercise.


2007 ◽  
Vol 39 (Supplement) ◽  
pp. S370
Author(s):  
Jason C. Holmes ◽  
Ann L. Gibson ◽  
Richard L. Desautels ◽  
Lyndsay B. Edmonds ◽  
Laura Nuudi

1960 ◽  
Vol XXXIV (II) ◽  
pp. 261-276 ◽  
Author(s):  
Mogens Osler

ABSTRACT The total body water as well as the distribution of water in the extracellular and intracellular compartments was determined in 23 infants born to diabetic mothers (diab. infants) and 15 infants born to normal mothers (normal infants). The total body water was determined by the dilution method using heavy water, and the extracellular water by the dilution method using thiosulphate. Intracellular water was calculated as total water less extracellular water. The analytical methods are described. Diab. infants proved to have a mean total body water of 2.48 litres or 70.2 per cent of the body weight, a mean extracellular water content of 1.41 litre or 38.5 per cent of the body weight, and a mean intracellular water content of 1.16 litre or 31.8 per cent of the body weight. Normal infants had a mean total body water of 2.58 litres or 78.2 per cent of the body weight, a mean extracellular water content of 1.53 litre or 44.9 per cent of the body weight, and a mean intracellular water content of 1.12 litre or 33.5 per cent of the body weight. The reduction in total and extracellular water in the diab. infants is statistically significant, whereas that of intracellular water is more doubtful. The reduction in total body water means that diab. infants are obese. A marked decrease in total as well as extracellular water without a substantial decrease in intracellular water cannot be due to obesity alone, since fat is assumed to contain more extracellular than intracellular water. Increased deposition of glycogen, which binds water in the cells and constitutes an intermediate product in the transformation of glucose to fat, can explain, when also considering the obesity, the reduction in total and extracellular water without a simultaneous decrease of intracellular water. Considering the influence of insulin, corticosteroids and growth hormone on the body composition, the author concludes that the changes found in the body composition of newborn infants of diabetic mothers (obesity + presumably increased glycogen) may be assumed to be due to maternal hyperglycaemia with consequent foetal hyperglycaemia + hyperinsulinism, but not to an action of maternal growth hormone. In other words, the result supports the so-called hyperglycaemia hypothesis as the cause of the increased weight and changed body composition of the newborn infants of diabetic women.


1980 ◽  
Vol 238 (1) ◽  
pp. R82-R90 ◽  
Author(s):  
G. T. Lesser ◽  
S. Deutsch ◽  
J. Markofsky

Total body water (TBW) and intracellular water (ICW = TBW minus extracellular water), when related to fat-free body mass (FFB), were recently observed to remain stable in healthy aged men and women. To expand these findings, a group of male Sprague-Dawley rats was followed from weaning to death. The design minimized several perturbations common to aging studies. At about 100-day intervals from 297 to 888 days, representative animals were killed for chemical studies. TBW/FFB was stable from 362 to 715 days, then significantly higher at 800 and 888 days. Extracellular water content of the fat-free body (ECW/FFB) increased significantly during middle life (362--579 days), then remained stable through 888 days. Changes of ICW/FFB were not significant. Aside from a uniquely higher value at 638 days, protein content did not differ significantly at any age. The stability of these major constituents suggested approximate maintenance of cell mass in healthy rats at late ages, a conclusion supported by additional observations of this colony and of an aged human population. We are unable to confirm the hypothesis that loss of FFB is part of the normal aging process.


2015 ◽  
Vol 2015 ◽  
pp. 1-11 ◽  
Author(s):  
Fernando Seoane ◽  
Shirin Abtahi ◽  
Farhad Abtahi ◽  
Lars Ellegård ◽  
Gudmundur Johannsson ◽  
...  

For several decades electrical bioimpedance (EBI) has been used to assess body fluid distribution and body composition. Despite the development of several different approaches for assessing total body water (TBW), it remains uncertain whether bioimpedance spectroscopic (BIS) approaches are more accurate than single frequency regression equations. The main objective of this study was to answer this question by calculating the expected accuracy of a single measurement for different EBI methods. The results of this study showed that all methods produced similarly high correlation and concordance coefficients, indicating good accuracy as a method. Even the limits of agreement produced from the Bland-Altman analysis indicated that the performance of single frequency, Sun’s prediction equations, at population level was close to the performance of both BIS methods; however, when comparing the Mean Absolute Percentage Error value between the single frequency prediction equations and the BIS methods, a significant difference was obtained, indicating slightly better accuracy for the BIS methods. Despite the higher accuracy of BIS methods over 50 kHz prediction equations at both population and individual level, the magnitude of the improvement was small. Such slight improvement in accuracy of BIS methods is suggested insufficient to warrant their clinical use where the most accurate predictions of TBW are required, for example, when assessing over-fluidic status on dialysis. To reach expected errors below 4-5%, novel and individualized approaches must be developed to improve the accuracy of bioimpedance-based methods for the advent of innovative personalized health monitoring applications.


1996 ◽  
Vol 76 (3) ◽  
pp. 325-332 ◽  
Author(s):  
A. Borghil ◽  
G. Bedogni ◽  
E. Rocchi ◽  
S. Severi ◽  
F. Farina ◽  
...  

AbstractWe assessed total body water (TBW) and extracellular water (ECW) in thirty-four non-ascitic cirrhotics and twenty healthy controls by 2H2O and Br dilution. In the same subjects, bioelectric impedance (BI) was recorded at multiple frequencies. Body hydration was similar for controls (mean 55·6 (SD 6·7)), less-severe cirrhotics (Child-Pugh classification A; CPA; n 21, mean 56·2 (SD 6·2)) and moderately-severe cirrhotics (Child-Pugh classification B; CPB; n 13, mean 57·2 (SD 5·4)). However, intracellular water standardized per litre TBW was significantly higher in CPB subjects (mean 27·0 (SD 7·5); P<0·01) compared with CPA (mean 21·3 (SD 10·6)) and control subjects (mean 18·0 (SD 9·8)). Published formulas for predicting TBW and ECW from BI at multiple frequencies were applied to the cirrhotics. These formulas gave accurate predictions of TBW and ECW, although standard errors of estimates were higher for CPB subjects (TBW ≤ 2·5 and ECW ≤ 2·11) than those for CPA (TBW ≤ 2·0 and ECW ≤ 1·81) and control (TBW 1·4 and ECW 0·9 1) subjects


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