Showing papers on "Body water published in 1995"
TL;DR: It is suggested that resistance exercise training improved muscle strength and anabolism in older men, but these improvements were not enhanced when exercise was combined with daily GH administration.
Abstract: The purpose of this study was to determine whether growth hormone (GH) administration enhances the muscle protein anabolism associated with heavy-resistance exercise training in older men. Twenty-three healthy, sedentary men (67 +/- 1 yr) with low serum insulin-like growth factor I levels followed a 16-wk progressive resistance exercise program (75-90% max strength, 4 days/wk) after random assignment to either a GH (12.5-24 micrograms.kg-1.day-1; n = 8) or placebo (n = 15) group. Fat-free mass (FFM) and total body water increased more in the GH group. Whole body protein synthesis and breakdown rates increased in the GH group after treatment. However, increments in vastus lateralis muscle protein synthesis rate, urinary creatinine excretion, and training-specific isotonic and isokinetic muscle strength were similar in both groups, while 24-h urinary 3-methylhistidine excretion was unchanged after treatment. These observations suggest that resistance exercise training improved muscle strength and anabolism in older men, but these improvements were not enhanced when exercise was combined with daily GH administration. The greater increase in FFM with GH treatment may have been due to an increase in noncontractile protein and fluid retention.
241 citations
TL;DR: The anthropometric model developed can be used to reasonably predict neonatal body fat mass at birth and is compared with a previously published anthropometric formula with total body electric conductivity.
193 citations
TL;DR: Multifrequency bioelectrical impedance analysis was used to estimate the ratio of extracellular water (ECW) to total body water in subjects with end-stage renal disease and the body's resistance was measured at frequencies ranging from 1 kHz to 1 MHz.
Abstract: Multifrequency bioelectrical impedance analysis was used to estimate the ratio of extracellular water (ECW) to total body water in subjects with end-stage renal disease. The body's resistance was measured at frequencies ranging from 1 kHz to 1 MHz. The impedance index (height2/resistance) determined at low frequency (5 kHz) correlated most closely with ECW (r = 0.886) using sodium bromide dilution as the standard of comparison. In contrast, the ratio of height squared to resistance determined at high frequency (500 kHz) correlated most closely with total body water (r = 0.974) using deuterium oxide dilution as the standard of comparison. The ratio of resistance at 500 kHz to resistance at 5 kHz was directly correlated (r = 0.767) with the ratio of ECW to total body water. Multifrequency bioelectrical impedance analysis may assist in the evaluation of body water distribution in endstage renal disease and other clinical disorders of fluid volume and/or distribution.
188 citations
TL;DR: It is demonstrated that the administration of rhGH and rhIGF-I for 4 weeks results in anabolic changes in body composition in elderly women, accompanied by numerous negative side-effects in the GH and high dose IGF groups, including headaches, lethargy, joint swelling/pain, and bloatedness.
Abstract: The purpose of this study was to determine the effects of recombinant human GH (rhGH; 0.025 mg/kg.day) and one of two doses of recombinant human insulin-like growth factor-I (rhIGF-I; 0.015 and 0.060 mg/kg, twice daily) on body composition in elderly women. Sixteen healthy elderly women (mean age +/- SEM, 71.9 +/- 1.3 yr) were randomly assigned to receive either rhGH (GH; n = 5), low dose rhIGF-I (n = 6), or high dose rhIGF-I (n = 5). A 2-week predrug baseline period was followed by 4 weeks of hormone treatment, with a standardized diet fed throughout. All groups experienced a significant increase in serum IGF-I and IGFBP-3 levels over the treatment period, accompanied by significant decreases in IGF-II (P < 0.05). Fat mass decreased in all groups, with significant increases in lean body mass and nitrogen retention occurring in the high dose IGF and GH groups. Total body water did not change, whereas increases observed in intracellular fluid approached significance (P = 0.06). These anabolic changes were ...
161 citations
Journal Article•
TL;DR: It was concluded that low levels of physical activity in pre-school children are associated with raised levels of body fat.
Abstract: The aim of this work was to investigate the relationship between levels of physical activity and body fatness in a group of pre-school children. A cross-sectional study was carried out, physical activity being assessed as the ratio of total energy expenditure/basal metabolic rate (TEE/BMR) and TEE minus BMR. TEE was measured by the doubly labelled water technique, BMR was predicted from body weight. Body fat content was assessed from measurements of total body water via stable isotope dilution. The subjects were 93 children, aged between 1.5 and 4.5 years, in South East England. Measurements of TEE were successful in 77 children. The correlation coefficient between the physical activity level (PAL) values and percentage body fat (sexes combined) was -0.52 (t = 5.3; P < 0.001). This figure indicates that a high level of body fat is associated with a low PAL value and that lower levels of body fat are associated with high PAL values. The correlation coefficient between TEE - BMR and percentage body fat was -0.51 (t = 5.1; P < 0.001). It was concluded that low levels of physical activity in pre-school children are associated with raised levels of body fat.
142 citations
TL;DR: Antidiuretic hormone concentrations (ADH) were significantly reduced from prehyperhydration levels during both hyperhydration trials but tended to rise during GI compared with WI at the very time urine flow and free water clearance differences were also evident, suggesting that ADH may, in part, be responsible for glycerol's effectiveness.
Abstract: Glycerol ingestion has been shown to mediate hyperhydration; however, the mechanism(s) responsible for this improved fluid retention is not well understood. This study examined the hormonal, renal, and vascular fluid responses to glycerol hyperhydration in 11 resting male volunteers who ingested one of two experimental solutions and then a water bolus. The volume of fluid ingested was determined from the subjects' measured total body water (TBW; total volume = 37 ml/l TBW, 1,765 +/- 162 ml). Experimental solutions (5.0 ml/l TBW) were matched for color and taste and differed only in that one contained 1.5 g glycerol/l TBW (total osmolar load = 777 +/- 24 mosmol). Nine of the 11 subjects also completed a control trial during which no fluid was ingested. Glycerol ingestion (GI) resulted in greater fluid retention than the ingestion of water alone (WI; 60 vs. 32% 3-h posthyperhydration, P < 0.01). This improved fluid retention with GI resulted from lower urine flow rates (peak 6.2 vs. 10.5 ml/min, P < 0.01) associated with lower free water clearance rates (peak = 1.2 vs. 8.2 ml/min, P < 0.01). Hyperhydration had no effect on plasma atrial natriuretic peptide concentrations. Changes in plasma aldosterone were unrelated to differences in fluid retention. Antidiuretic hormone concentrations (ADH) were significantly reduced from prehyperhydration levels during both hyperhydration trials but tended (P = 0.07) to rise during GI compared with WI at the very time urine flow and free water clearance differences were also evident. This suggests that ADH may, in part, be responsible for glycerol's effectiveness, although differences in ADH concentrations were small and near the assay's sensitivity limits. Alternatively, glycerol's effectiveness may result from its directly increasing the kidneys' medullary concentration gradient and, hence, water reabsorption.
124 citations
TL;DR: It is concluded that a simple impedance analyser operating at only two frequencies compares favourably with the more complex spectroscopy technique for the determination of extracellular and total body water in surgical patients.
Abstract: 1. Measurements of extracellular and total body water provide useful information on the nutritional status of surgical patients and may be estimated from whole-body bio-impedance measurements at different frequencies. 2. Resistance and reactance were measured at 50 frequencies from 5kHz to 1MHz in 29 surgical patients (17 males, 12 females) with a wide range of extracellular to total body water ratios. 3. A fit to the spectrum of reactance versus resistance data gave predicted resistances at frequencies zero and infinity. Values of extracellular and total body water determined by this bio-impedance spectroscopy technique were regressed against values obtained from radioisotope dilution. The standard errors of the estimate were 1.8931 and 3.2591 respectively. 4. Resistance indices (height2/resistance) at selected frequencies gave the highest correlations with extracellular and total body water at 5kHz and 200kHz respectively, and prediction equations derived from multiple stepwise regressions also showed these to be the optimum frequencies. The standard errors of the estimate for this multi-frequency bio-impedance analysis method were 1.9371 and 2.6061 for extracellular and total body water respectively. 5. To assess the ability of the two methods to measure changes in extracellular and total body water, reproducibility was assessed from repeat measurements 10 min apart in a subgroup of 15 patients. Bio-impedance spectroscopy gave mean coefficients of variation for extracellular and total body water of 0.9% and 3.0% respectively. For multi-frequency bio-impedance analysis the corresponding coefficients of variation were 0.9% and 0.6%. 6. It is concluded that a simple impedance analyser operating at only two frequencies compares favourably with the more complex spectroscopy technique for the determination of extracellular and total body water in surgical patients.
121 citations
TL;DR: Observations confirmed the influence of posture on inter-compartmental body-fluid distribution, as the intravascular fluid loss when standing was caused by the filtration of plasma into the interstitium, while, during supine rest, intrav vascular volume increased, reflecting fluid flux from the interStitium to the circulation.
Abstract: Inter-compartmental body-fluid distribution is contingent upon posture, exercise state and environmental temperature. This investigation aimed at quantifying the distribution of intra- and extravascular fluid volumes during postural manipulations. Fluid shifts were measured in eight males utilizing a simultaneous, radionuclide dilution technique, in which radioiodinated serum fibrinogen, radiochromated erythrocytes, radiobromine and tritiated water were used to measure plasma, red cell, extracellular and total body water volumes. Subjects were exposed to three postural changes [seated (control), supine and standing] for 30 min at an air temperature of 22.0 degrees C, with each posture separated by 30 min seated rest. Total body water content remained stable throughout postural changes (P = 0.842). Relative to seated volumes, BV increased by 89 mL when supine, and decreased by 406 mL while standing (P = 0.003), with such shifts being primarily a result of plasma movement (P = 0.011). Red cell volume changes were not significant. Vascular fluid lost during standing was filtered into the interstitial compartment (P = 0.014), with the extracellular and intracellular volumes remaining unaffected. (P = 0.271 and P = 0.800, respectively). These observations confirmed the influence of posture on inter-compartmental body-fluid distribution. The intravascular fluid loss when standing was caused by the filtration of plasma into the interstitium, while, during supine rest, intravascular volume increased, reflecting fluid flux from the interstitium to the circulation.
101 citations
TL;DR: Results suggest that BIS may be useful in estimating volumes of ECF and TBW during pregnancy, and examine the accuracy of bioelectrical impedance spectroscopy for estimating fluid volumes before, during, and after pregnancy.
Abstract: The increase in body water during pregnancy is responsible for the largest portion of weight gain and is of interest of clinical practitioners. However, assessing changes in body fluids is not easi...
94 citations
TL;DR: It is concluded that fluid restriction does not improve the outcome of acute meningitis and indeed a decrease in ECW volume at 48 hours increases the likelihood of adverse outcome.
Abstract: The objective of this prospective study was to examine the effect of fluid restriction on body water and the outcome of children with acute meningitis. Fifty consecutively hospitalized children with acute meningitis, divided into two groups (A, without hyponatremia ; and B, with hyponatremia), were randomly assigned to receive either normal maintenance (M) or restricted (R subgroup) (65 to 70% of M subgroup) fluids during the first 48 hours. Total body water, extracellular water (ECW), serum and urinary sodium and plasma and urinary osmolality were measured at admission and after 48 hours. In both groups children receiving restricted fluids showed a significant decrease in the mean total body water and ECW whereas body water remained unchanged in those on maintenance fluids. Children having an ECW reduction of 10 ml/kg or more in 48 hours had a significantly lower intact survival (10 of 28, 36%) than those with <10 ml/kg or no reduction of ECW (15 of 22, 64%) (P < 0.05). The mortality was also higher in the former (7 of 28, 25%) than in the latter (2 of 22, 9%). On multiple stepwise regression analysis, ECW volume at admission (partial r 2 0.20), ECW loss in 48 hours (partial r 2 0.13) and plasma osmolality at admission (partial r 2 0.22) were significantly related to outcome. We conclude that fluid restriction does not improve the outcome of acute meningitis. Indeed a decrease in ECW volume at 48 hours increases the likelihood of adverse outcome.
93 citations
TL;DR: Despite the factors that have a negative effect on BMD, such as low body mass and late menarche, BMD in female ballet dancers was relatively high, probably caused by high levels of weight-bearing physical activity.
Abstract: The main purpose of the present study was to examine factors that affect bone mineral density (BMD) in female ballet dancers. Training history, Ca intake, body composition, total body BMD (TBMD) and site-specific BMD, and bone mineral content were described in twenty-four female ballet dancers (mean age 22.6 (SD 4.5) years). Training history was determined by questionnaires, Ca intake by 7 d dietary record, BMD and bone mineral content by dual-energy X-ray absorptiometry (DXA), total body water by 2H dilution, extracellular water by bromide dilution, body fat by underwater weighing (UWW; two-component model), DXA, and the four-component (4C) model. Dancers had a significantly lower body mass index (BMI 18.9 (SD 1.0) kg/m2) than controls (21.3 (SD 1.9) kg/m2), with significantly lower percentage body fat (17.4 (SD 3.9) v. 24.4 (SD 5.1)) but comparable fat-free mass. Mean TBMD (1.147 (SD 0.069) g/cm2) was significantly higher (6%) compared with that of a reference population. These high values could be attributed to the high BMD of legs and pelvis, the weight-bearing sites of the dancer's body. No relationship was found between age, start of ballet classes, period (years) of dancing, Ca intake, and BMD (total and site-specific). However, TBMD was positively related to BMI, and negatively related to the age of menarche. BMD of the legs was significantly related to BMI, and negatively related to the age of menarche. BMD of the legs was significantly related to daily period (h) of training. Depending on the method used the percentage body fat ranged from 16.4 (by DXA) to 18.3 by the 4C model. These differences were significantly related to the TBMD. Percentage body fat by the different methods was not significantly different, except for DXA and 4C model. The present study showed that, despite the factors that have a negative effect on BMD, such as low body mass and late menarche, BMD in female ballet dancers was relatively high. These high values were probably caused by high levels of weight-bearing physical activity.
TL;DR: In conclusion, BIA, DEXA, TBW, and STK are equally valuable for estimating fat in those with tetraplegia.
Abstract: Spinal cord injury (SCI) is a unique condition that markedly alters body composition, raising the possibility of having undefined effects on the traditional assumptions for body composition. In order to determine appropriate methods for the analysis of body composition in this population, 12 subjects with tetraplegia were studied for absolute weight as fat and percent fat by the following methods; bioelectrical impedance (BIA), dual energy X-ray absorptiometry (DEXA), total body potassium (TBK), total body water (TBW), and four anthropometric methods: Durnin and Womersley (DUR), Jackson and Pollack (J and P), Sloan (SLN) and Steinkamp et al (STK). The eight methods were compared with the mean of all means (24.4 +/- 2.2% fat), which was assumed to be the best estimate of percent fat. Four methods: BIA, DEXA, TBW and STK were not significantly different, while TBK, DUR, J&P and SLN were significantly (P < 0.009) different from the mean of the means. Using only the non-significantly different methods, repeat computation revealed TBW to have the smallest difference from the mean (0.1 +/- 2.8%), and DEXA to have the strongest correlation with the line of identity (r = 0.96, P < 0.0001). In conclusion, BIA, DEXA, TBW, and STK are equally valuable for estimating fat in those with tetraplegia.
TL;DR: The use of low-dose OC (EE2 plus gestodene) was not associated with overall impact on weight, body composition, or fat distribution, however, when weight gain did occur during OC use, it was due to increase in body fat and not in volume of body water, and it was notassociated with changes in fat distribution.
01 Jan 1995
TL;DR: Prentice et al. as discussed by the authors used dual-energy X-ray absorptiometry and related techniques to the assessment of bone and body composition, including Magnetic Resonance Imaging (MRI) and In vivo Neutron Activation Analysis (ION).
Abstract: List of contributors 1. Application of dual-energy X-ray absorptiometry and related techniques to the assessment of bone and body composition A. Prentice 2. In vivo neutron activation analysis: past, present and future S. J. S. Ryde 3. Magnetic resonance imaging for the assessment of body composition P. Brambilla, P. Manzoni, P. Simone and G. Chiumello 4. Multi-frequency impedance as a measure of body water compartments P. Deurenberg 5. Body composition assessed by electrical conductivity methods J. F. Sutcliffe and M. A. Smith 6. Body composition in malnutrition P. S. Shetty 7. Influence of body composition on protein and energy requirements: some new insights C. J. K. Henry 8. Prediction of adult body composition from infant and child measurements M. F. Rolland-Cachera 9. Assessment of body composition in the obese E. M. E. Poskitt 10. The role of body physique assessment in sports science M. H. Slaughter and C. B. Christ 11. The assessment of the body composition of populations N. G. Norgan 12. Changes in approach to the measurement of body composition J. Parizkova 13. Multi-compartment models for the assessment of body composition in health and disease S. A. Jebb and M. Elia 14. The future of body composition research S. B. Heymsfield and Zi-Mian Wang Index.
TL;DR: The CrKin technique for estimating LBM at normal body fluid volumes (dry weight) may be a better index of nutritional status in patients on CAPD because this may truly reflect the dry LBM and changes in muscle mass.
Abstract: Lean body mass (LBM), which is fat free body mass, can be used as an index of nutritional status. We evaluated three techniques for LBM estimation, including dual energy x-ray absorptiometry (DEXA), creatinine kinetics (CrKin), and bioimpedance (BI) in 10 patients on continuous ambulatory peritoneal dialysis (CAPD). Two different formulae were applied for BI LBM estimation, Segal (S) and Deurenberg (D). Mean values (+/- SEM) of LBM estimated were 48.2 +/- 3.6, 46.12 +/- 2.87, 43.32 +/- 3.87, and 41.27 +/- 4.26 by DEXA, BI-S, BI-D, and CrKin, respectively. LBM by CrKin was significantly lower than that by DEXA and BI-S values. There was no statistically significant difference between DEXA and BI-S values. Statistically significant correlations were found between LBM values by all methods. Particularly strong correlations were found between DEXA versus BI-S (r = 0.976) and BI-S versus BI-D (r = 0.98). Because clinical assessment of hydration status is inaccurate, and both BI and DEXA measure excess extracellular water in LBM, falling muscle mass may be missed by these techniques. The CrKin technique for estimating LBM at normal body fluid volumes (dry weight) may be a better index of nutritional status in patients on CAPD because this may truly reflect the dry LBM and changes in muscle mass. Both DEXA and BI include excess body water in LBM and may mask malnutrition in the presence of subclinical or clinical overhydration, which is common in patients on peritoneal dialysis.
Journal Article•
TL;DR: Investigation of the utility of multifrequency bioelectrical impedance for the estimation of total body water and extracellular water in an elderly population found it useful to assess TBW and ECW in groups of elderly subjects, but the prediction errors are larger compared to young and middle-aged subjects, and are related to body water distribution.
Abstract: Objective The objective of this study was to investigate the utility of multifrequency bioelectrical impedance for the estimation of total body water (TBW) and extracellular water (ECW) in an elderly population. Design Body impedance at 8 frequencies (1-1350 kHz) was measured in duplicate within 1 week. TBW and ECW were determined using deuterium oxide and potassium bromide dilution respectively. Setting At the Department of Human Nutrition. Subjects 81 women and 36 men, aged 63-87 years, volunteered as subjects. Results Application of prediction equations from the literature, which are mostly based on impedance measurements in young and middle-aged subjects, resulted in large prediction errors of TBW and ECW which were related to the water distribution of the body. New sex-specific prediction equations for the estimation of TBW and ECW were developed for the elderly population and internally validated in random sub-groups. TBW and ECW were best predicted using impedance at frequencies of 5 and 50 kHz respectively, and by using body weight. Prediction errors for TBW were 3.1 kg (7.3%) and 2.7 kg (8.5%) and for ECW 2.2 kg (12.3%) and 1.0 kg (7.4%) for men and women respectively. Conclusions Multi-frequency impedance measurements are useful to assess TBW and ECW in groups of elderly subjects. However, the prediction errors are larger compared to young and middle-aged subjects, and are related to body water distribution. Individual errors are sometimes unacceptably large.
TL;DR: DXA is a useful tool for estimating the magnitude of body compartments in patients with end-stage renal failure and a positive correlation between fluid loss during dialysis and reduction in fat-free mass was observed.
Abstract: Dual-energy X-ray absorptiometry (DXA) measures three of the principal components of the body: fat mass, lean soft-tissue mass (comprising muscle, inner organs, and the body water), and the bone mineral content. The purpose of this study was to test the estimation capacity of DXA when it is applied to patients with end-stage renal failure. Twenty dialysis patients were examined by DXA before and after one hemodialysis session. A highly significant positive correlation between weight measurements performed by conventional scales and DXA was found. A positive correlation between fluid loss during dialysis and reduction in fat-free mass (lean soft-tissue mass plus bone mineral content) was observed by DXA. The estimation of the fat-free mass was independent of the amount of fluid loss. No significant differences in variance between the data obtained before and after the dialysis were observed. We conclude that DXA is a useful tool for estimating the magnitude of body compartments in patients with end-stage renal failure.
TL;DR: The results highlight the importance of either measuring both DB and TBW or using an appropriate hydration constant for FFM in estimating body composition during pregnancy or conditions associated with increased body water.
Abstract: Twenty women underwent body density (DB) measurements using underwater weighing with correction of residual lung volume by nitrogen dilution and total body water (TBW) using isotope dilution of 18O to estimate body composition at 30 wk of gestation. DB and TBW were used as independent variables in the same equation. The hydration constant (HC) of fat-free mass (FFM) was estimated as 0.762; based on this HC, new body composition equations for both DB and TBW were derived. These equations were prospectively tested in an additional 20 women at 30 wk of gestation. No significant differences were detected between estimates of percent body fat (%F) using either the newly derived DB or TBW equations and estimates of %F using both DB and TBW. Ten of these forty women were evaluated postpartum. There was no significant difference in %F estimated by either TBW or DB compared with standard equations (hydration of FFM = 0.72) and %F using both DB and TBW. These results highlight the importance of either measuring both DB and TBW or using an appropriate hydration constant for FFM in estimating body composition during pregnancy or conditions associated with increased body water.
TL;DR: Measurements of total body water and total body lipid, obtained by hydrogen isotope dilution, were compared to the results of bioelectrical impedance analysis (BIA) and morphometric indices of body condition in 52 adult females and body mass alone was highly correlated to TBW.
Abstract: An attempt was made to develop simple, inexpensive, rapid means of determining body composition in Antarctic fur seals (Arctocephalus gazella). Measurements of total body water (TBW) and total body lipid (TBL), obtained by hydrogen isotope dilution, were compared to the results of bioelectrical impedance analysis (BIA) and morphometric indices of body condition in 52 adult females. TBW was weakly correlated with BIA measurements of resistance (v= -0.30, P < 0.03). Conductor volume (length2/resistance) was more highly correlated with TBW(r= 0.75, P < 0.0001) and the inclusion of mass into the predictive equation improved the correlation further (r= 0.95, P < 0.0001). A body condition index (mass/length) previously used in pinniped studies was positively correlated to TBL (r= 0.77, P < 0.0001) validating its use as a relative index of condition. However, body mass alone was highly correlated to TBW (r= 0.94, P < 0.0001) and appears to provide a simple, rapid means of estimating body composition in adult females. This technique may also be applicable to juvenile male Antarctic fur seals.
TL;DR: The results show that multifrequency impedance is able to predict ICW, however, the prediction is influenced by body water distribution.
Abstract: Body composition was measured in 57 healthy males by 40K measurements and by multifrequency bioelectrical impedance. Intracellular resistance (Ricf) was calculated from the impedance values using the Cole-Cole model. From total body potassium, intracellular water (ICW) was calculated. In addition, in 14 subjects, total body water (TBW) and extracellular water (ECW) was measured using deuterium oxide dilution and bromide dilution, respectively. Prediction formulas from the literature from impedance at different frequencies were used to predict TBW and ECW, and ICW was calculated as the difference of predicted TBW and ECW. Predicted and measured values of TBW, ECW and ICW did not always show the same values as measured. Generally the ICW from potassium was well correlated with calculated ICW from impedance values, correlation coefficients varying from 0.68 to 0.79, depending on the used prediction formula. From the impedance index H2/Ricf, body weight and age, ICW from potassium was predicted with stepwise multiple regression. The prediction formula was ICW = 0.37065.H2/Ricf - 0.132.age + 0.105.weight + 12.2. The prediction error was 1.9 kg and the explained variance 0.69. The residuals of this prediction formula were dependent on the level of ICW as measured by potassium. The same phenomenon was observed when ICW was calculated as the difference of predicted TBW and ECW. The results show that multifrequency impedance is able to predict ICW, however, the prediction is influenced by body water distribution.
TL;DR: The data suggest that bioelectrical impedance measurements give valid and reliable estimates of FFM in children and adolescents, and could be incorporated in the auxologic follow up of children on hormone therapy.
Abstract: The determination of body composition as part of the clinical and auxologic follow up of childhood growth disorders necessitates the use of a quick, portable, reliable and simple non-invasive method. The present study was undertaken to validate bioelectrical conductance, height2/resistance (Ht2/R), against isotopically determined total body water (TBW) using heavy water tracer H2[18O]. The subjects (n = 56) consisted of normal children, children with various endocrine disorders, and young adults between the ages of 8-26 years. Isotopically determined TBW and fat free mass (FFM) were highly correlated with Ht2/R (r = 0.94, p = < 0.001, and r = 0.94, p = < 0.001, respectively). In a multiple regression analysis, 96% of the variability in FFM in normal subjects could be predicted by the following equation: FFM = 0.524 Ht2/R + 0.415 Wt-0.32, while in the group of patients by FFM = 0.659 Ht2/R + 0.254 Wt + 2.851. These data suggest that bioelectrical impedance measurements give valid and reliable estimates of FFM in children and adolescents. This easy technique could be incorporated in the auxologic follow up of children on hormone therapy.
TL;DR: Estimations of empty body fat and empty body energy from D2O dilution were capable of detecting significant differences in bodyfat and body energy across physiological stages and might be useful for prediction of body composition changes during the lactation cycle.
TL;DR: The results indicate that the validity of predicted body water from impedance depends on the body build of the subjects, which should be taken into account to avoid systematic errors when applying prediction formulas from a reference population to another population under study.
Abstract: Total body water (TBW) and extracellular water (ECW) were measured by deuterium oxide dilution and bromide dilution, respectively, in a group of 24 male and 20 female healthy Ethiopians, living in the capital Addis Ababa. Body weight, body height, skinfolds and total body impedance at 1 and at 100 kHz were also measured. TBW and ECW were predicted from impedance values at 1 and 100 kHz, respectively, using prediction equations developed in a Dutch adult population. ECW was overestimated by 1.3 ± 1.0 kg (p
TL;DR: Values in impedance reflect changes in total body water in children undergoing haemodialysis and are relatively insensitive to factors such as the possible differences in electrolyte levels between these patients, similar to those obtained from isotope dilution studies.
Abstract: The sensitivity of whole-body electrical impedance measurements to changes in the volume of total body water in 12 children undergoing haemodialysis has been assessed. The impedance (I) of each child was measured at 20-min intervals during dialysis using the standard four-electrode technique to apply a constant current (800 microA, 50 kHz) between the wrist and ankle on the non-fistula side of the patient. The ultrafiltration volume (U) was also recorded. A simple electrical model suggests that U = aHt2 ((1/I0)-(1/I)), where I0 is the whole body impedance at the start of dialysis, a is a constant and Ht is patient height. No significant changes in I were measured on 4 patients undergoing dialysis without ultrafiltration, whereas in 8 patients undergoing ultrafiltration and dialysis I increased. Linear regression analysis and the above equation gave a mean value for a = 0.566 1 Ohm/cm2 (coefficient of variation = 3%), (mean r = 0.97), values comparable to those values obtained from isotope dilution studies. Predicted fluid loss in 8 patients following a single dialysis session gave a mean overestimate of 4.3% (limits of agreement 27.3% and -19.7%), although in 6 of the patients agreement was to within 6%. Changes in impedance reflect changes in total body water in children undergoing haemodialysis and are relatively insensitive to factors such as the possible differences in electrolyte levels between these patients.
TL;DR: Findings show that impedance measurements have a low sensitivity in detecting the volume of ascites in cirrhotic patients, whereas Xc has a clinical use in monitoring changes in extracellular water (EW).
TL;DR: The data suggest that the measurement of electric resistance across the body can accurately detect acute changes in total body water and in fluid redistribution through the body after cardiopulmonary bypass.
TL;DR: Bio‐impedance analysis was effective in predicting body composition when subjects are specified by age, sex, stature, weight, and race for subjects from 18 to 94 years of age.
Abstract: Bio-impedance analysis (BIA) measurements have been used to predict components of body composition. Their validation is required for populations varying in race, sex, and age. In 371 Whites, 182 Blacks and 225 Asians, single-frequency BIA at 50 kHz (RJL-100) resistance and reactance measurements were correlated with same-day measurements of total body water (TBW) by THO dilution, total body potassium (TBK) by whole body 40 K counting, and fat-free mass (FFM) by dual-photon absorptiometry. BIA correlation coefficients with TBW, TBK, FFM, and fat varied by sex and race for all measured body composition components. The highest correlation was for FFM, and the lowest was for fat mass. Prediction equations were further improved by including age, stature, and weight for each of the study cohorts. The SEE for predictions were in the ranges of 5-6, 6-8, and 7-10% of measured FFM, TBW, and TBK, respectively. BIA was effective in predicting body composition when subjects are specified by age, sex, stature, weight, and race for subjects from 18 to 94 years of age. © 1995 Wiley-Liss, Inc.
TL;DR: BIA may be a particularly useful, practical technique for estimating body composition in older adults because BIA is not limited to ambulatory subjects.
Abstract: The purpose of this study was to compare the relationships of anthropometric, bioelectrical impedance analysis (BIA), and near infrared interactance (NIR) measurements with a multiple-component (MC) criterion estimate of body composition derived from body density (D), body water (W), and bone mineral (B) in 48 white adults aged 49-80 yr. Relative errors of predicting the MC criterion from the practical measurements were determined by simple regressions within gender and calculated as the SEE divided by the criterion mean and expressed as a percentage. Relative errors were lowest for the BIA variable, height2/resistance (4.8-5.0%), higher for body mass index and the sum of 10 skinfold thicknesses (7.0-14.5%), and highest for NIR-derived optical density readings at the biceps and the sum of 10 sites (10.8-15.8%). Due to the low relative prediction error for height2/resistance, sex-specific BIA formulas for estimating fat-free mass from D, W, and B (FFM-DWB) were developed. The SEEs for predicting FFM-DWB from BIA, weight, and age were both 1.5 kg in women and men. Because BIA is not limited to ambulatory subjects, it is concluded that BIA may be a particularly useful, practical technique for estimating body composition in older adults.
TL;DR: GH administration induces an elevation in total body water which may involve a stimulation of plasma renin and an increased ECV without any changes in PV or diurnal blood pressure.
Abstract: Side effects that can be related to fluid retention are common during the initial phases of growth hormone (GH) administration. The aim of this study was to examine the changes in body fluid compartments, diurnal blood pressure and plasma renin concentration during GH administration with two different dosages in healthy adults. Eight healthy male subjects aged 24–32 years were examined during three 2-week study periods in a double-blind placebo controlled study. They received, in random order, GH (3 or 6 IU m−2 daily) or placebo during 2 weeks. Bio-impedance was measured every 2nd day, and extracellular volume (ECV) and plasma volume (PV) were isotopically determined at day 6. Blood samples were obtained regularly. Diurnal blood pressure was recorded and 24-h urinary samples were collected at days 0, 6 and 14. ECV (1) was increased by GH (placebo, 19.58 ± 0.82; 3 IU m−2, 20.77 ± 1.22; 6 IU m−2, 20.65 ± 0.94; p<0.01), whereas PV (1) was unaffected (placebo, 3.91 ± 0.20; 3 IU m−2, 4.04 ± 0.22; 6 IU m−2, 3.9...
Journal Article•
TL;DR: It is concluded that bronchiolitis of infancy is characterized by water retention which is caused by impaired renal water excretion and careful attention to fluid therapy is mandatory; liberal fluid therapy may lead to water intoxication.
Abstract: Children with acute bronchiolitis frequently require hospitalization and parenteral fluid therapy. Water retention due to impaired renal water excretion has been described in several pulmonary conditions in children. We studied 20 infants (3.6 +/- 2.9 months), hospitalized consecutively for acute bronchiolitis for water and electrolyte changes during the acute stage and compared them to those on recovery. Serum sodium and plasma osmolality, urinary sodium and osmolality were measured in all infants. Ten infants each were assigned alternatively to study body water compartment or renal water handling (water load excretion and free water excretion capacity) on the day of hospitalization and after recovery. Mean ( +/- SD) value of serum sodium of the infants at admission was 132.7 +/- 7.2 mEq/L which increased to 137.1 +/- 5.4 mEq/L on recovery (p < 0.05). Plasma osmolality changed from 284 +/- 14 mOsm/kg at admission to 294 +/- 10 mOsm/kg at recovery (p < 0.05). There was a significant decrease in urinary sodium from 54 +/- 39 mEq/L to 20 +/- 18 mEq/L and urinary osmolality from 415 +/- 213 mOsm/kg to 252 +/- 204 mOsm/kg at admission and at recovery, respectively. All 10 infants showed significant increase in total body water (mean +/- SD; 22.8 +/- 7.5 ml/kg) at admission as compared to that at recovery. The total body water (TBW) excess was mainly in extracellular water compartment (16.3 +/- 3.6 ml/kg). Seven of 10 infants had significant impairment in renal water excretion. Increase in maximum free water clearance of these 7 infants on recovery was 0.69 +/- 0.27 ml/min, i.e., 15 times more than that at admission. It is concluded that bronchiolitis of infancy is characterized by water retention which is caused by impaired renal water excretion. In the management of severe bronchiolitis careful attention to fluid therapy is mandatory; liberal fluid therapy may lead to water intoxication.