scholarly journals Using Dilution Techniques and Multifrequency Bioelectrical Impedance to Assess Both Total Body Water and Extracellular Water at Baseline and During Recombinant Human Growth Hormone (GH) Treatment in GH-Deficient Adults*

1997 ◽  
Vol 82 (10) ◽  
pp. 3349-3355 ◽  
Author(s):  
Y. J. H. Janssen ◽  
P. Deurenberg ◽  
F. Roelfsema

Abstract Due to the use of various, and mostly indirect, methods to estimate total body water (TBW) and extracellular water (ECW), there is no agreement about whether body water distribution, i.e. the ECW to TBW ratio, is normal in GH-deficient (GHD) subjects at baseline and during recombinant human GH (rhGH) treatment. We studied body water distribution in 14 patients with adult-onset GHD and in 28 healthy controls. We also investigated the effect of GH replacement therapy for 4 and 52 weeks on body water distribution. All patients started with a dose of 0.6 IU rhGH/day for the first 4 weeks. After 52 weeks, the dose varied between 0.6–1.8 IU/day. TBW and ECW were measured by dilution of deuterium and bromide, respectively. Both parameters were also estimated using multifrequency bioelectrical impedance (BIA). Patients with GHD had significantly lower ECW and TBW than healthy controls. In addition, the ECW to TBW ratio was significantly lower in GHD patients than in healthy controls. Four weeks of GH treatment significantly increased body weight, TBW, ECW, and ECW/TBW. A further increase in TBW, but not ECW, was found after 52 weeks of treatment. The mean increases in TBW and ECW from the baselines were 2.5 ± 0.3 and 2.0 ± 0.3 L, respectively. The correlation coefficient and the estimated reliability between measured and estimated TBW and ECW at any time point were all high (>0.91 and >0.95, respectively). In general, both ECW and TBW were overestimated by multifrequency BIA in GHD adults. During treatment, the overestimation of both ECW and TBW diminished. The estimation error was correlated with the level of the body water compartment and the ratio of ECW to TBW. The estimated change in ECW with rhGH treatment was underestimated by multifrequency BIA. We conclude that GHD adults have lower ECW and TBW and a lower ECW to TBW ratio, as measured by dilution techniques. The ECW to TBW ratio can be normalized within 4 weeks of rhGH treatment at a dose of 0.6 IU/day. Finally, we conclude that multifrequency impedance measurements do not give valid estimates of body water compartments in the follow-up of patients with GHD.

1995 ◽  
Vol 73 (3) ◽  
pp. 349-358 ◽  
Author(s):  
Paul Deurenberg ◽  
Anna Tagliabue ◽  
Frans J. M. Schouten

The relationship between total body water (TBW) and extracellular water (ECW), measured by deuterium oxide dilution and bromide dilution respectively, and impedance and impedance index (height2/impedance) at 1, 5, 50 and 100 kHz was studied. After correction for TBW, ECW was correlated only with the impedance index at 1 and 5 kHz. After correction for ECW, TBW was best correlated with the impedance index at 100 kHz. The correlation of body-water compartments with impedance values obtained with modelling programs was lower than with measured impedance values. Prediction formulas for ECW (at 1 and 5 kHz) and TBW (at 50 and 100 kHz) were developed. The prediction errors for ECW and TBW were 1·0 and 1·7 kg respectively (coefficient of variation 5%). The residuals of both ECW and TBW were related to the ECW/TBW value. Application of the prediction formulas in a population, independently measured, revealed a slight overestimation of TBW and ECW, which could be largely explained by differences in the validation group in body-water distribution and in body builds. The ratio of impedance at 1 kHz to impedance at 100 kHz was correlated with body-water distribution (ECW/TBW). The relation is however not strong enough to be useful as a predictor. It is concluded that an independent prediction of ECW and TBW, using impedance at low and high frequency respectively, is possible, but that the bias depends on the body-water distribution and body build of the measured subject.


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.


1995 ◽  
Vol 18 (11) ◽  
pp. 693-699 ◽  
Author(s):  
P.M.J.M. De Vries ◽  
A. Vonk Noordegraaf ◽  
B.J.M. Van Der Meer ◽  
H.H. Woltjer ◽  
J.P.P.M. De Vries

Bioelectrical impedance analysis forms a non-invasive tool for detection of body fluids. Total body measurement gives total body water (TBW) and, in case of multi-frequency analysis, of intra- and extracellular fluid volume. The thoracic approach measures thoracic fluid (TF). The set-up of both techniques is discussed. An overview is given of the clinical usefulness of the total body technique to monitor fluid changes and the process of refill during hemodialysis and to detect dry weight. The simultaneous measurement of TBW and TF was applied to obtain a more detailed picture of the body fluids. In a group of healty subjects the age dependency of both variables was shown. During hemodialyss TBW and TF showed a major and comparable decrease. Fluid retention during cardiac surgery led to a slightly more pronounced increase of TF than of TBW. The combination of both impedance techniques offers clinicians a means to monitor alterations in fluid status in patients in more detail.


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