Creatine Supplementation Increases Total Body Water Without Altering Fluid Distribution

OBJECTIVE: To examine the effects of oral creatine (Cr) monohydrate supplementation on muscle Cr concentration, body mass, and total body water (TBW), extracellular water (ECW), and intracellular water (ICW) volumes. DESIGN AND SETTING: After an overnight fast, urinary Cr and creatinine concentrations, muscle Cr concentration, body mass, TBW, ECW, and ICW were measured, and subjects were randomly assigned to either a Cr or a placebo (P) group. The Cr group ingested 25 g/d of Cr for 7 days (loading phase) and 5 g/d for the remaining 21 days (maintenance phase), whereas the P group ingested a sucrose P using the same protocol. All the measures were reassessed immediately after the loading and maintenance phases. SUBJECTS: Sixteen men (age = 22.8 +/- 3.01 years, height = 179.8 +/- 7.1 cm, body mass = 84.8 +/- 11.2 kg) and 16 women (age = 21.8 +/- 2.51 years, height = 163.4 +/- 5.9 cm, body mass = 63.6 +/- 14.0 kg) involved in resistance training volunteered to participate in this study. MEASUREMENTS: Muscle Cr concentration was determined from the vastus lateralis muscle using a percutaneous needle-biopsy technique. Total body water, ECW, and ICW volumes were assessed using deuterium oxide and sodium bromide dilution analyses. RESULTS: The Cr group experienced a significant increase in muscle Cr concentration, body mass, and TBW. The P group experienced a small but significant increase in TBW only. CONCLUSIONS: The Cr supplementation protocol was effective for increasing muscle Cr concentrations, body mass, and TBW; however, fluid distribution was not changed.     

Body fluid distribution in elderly subjects with congestive heart failure

The aims of this study were to investigate body fluid changes in elderly patients suffering from congestive heart failure (CHF) and to identify the fluid measurement that best characterizes fluid overload states in CHF patients by comparison with normal hydration in the elderly. In a case-controlled experimental design, 72 elderly subjects (65-98 yr), 38 healthy and 34 with CHF, were studied. Total body water (TBW) and extracellular water (ECW) were determined by dilution methods; fat-free mass (FFM) and fat mass (FM) were determined by dual-energy X-ray absorptiometry (DEXA). In healthy subjects, the FFM hydration expressed as TBW% FFM (males 72.0 +/- 4.3 vs females 72.4 +/- 5.0%) and ECW% TBW (males 47.3 +/- 3.4 vs females 47.8 +/- 5.1) were similar in both genders. ECW in liters for FFM and for TBW (ECW% TBW), corrected for body weight, was greater in the group with CHF than in the control group, in both sexes. Among the relative fluid measures, only ECW% TBW [odds ratio (OR) 1.5] independently predicted fluid retention. Having an ECW% TBW greater than 50% corresponded to an OR of about 10. In conclusion, elderly patients suffering from CHF have a characteristic increase in body fluid levels, mainly affecting the extracellular compartment, and ECW% TBW is a useful indicator of fluid retention.     

Growth of the pig: changes in body weight and body fluid compartments.

Body weight and the rate of change in TBW, ECW, and ICW were measured in 252 anesthetized pigs during the first 12 weeks after birth. After TBW was measured with 3H2O, 55 of the pigs were killed and TBW measured by desiccation. 3H2O overestimated TBW by 6.5% of body weight and 4.9% of fat-free wet weight, compared to desiccation (P less than 0.001); mean figures for 3H2O were 78.6 +/- 1.02% of body weight, and for desiccation, 72.1 +/- 0.45%; on a FFWW basis, 88.6 +/- 0.94% for 3H2O, and 83.7 +/- 0.13% for desiccation. TBW decreased significantly from 85.0% of body weight at birth (1.5 dg) to 75% at 5 kg (day 28) at a rate of ---3.2% body wt/kg body wt (P less than 0.001 from a zero rate). After that the rate of decrease was not different from zero: --0.117% body wt/kg body wt. ECW decreased significantly from 48% at birth to 35% at day 28 at a rate of --3.802% body wt/kg body wt (P less than 0.001 from a zero rate), and after day 28 the rate of decrease was not different from zero (--0.149% body wt/kg body wt) through week 12. ICW decreased, but not significantly, at a rate of --0.099% body wt/kg body wt. The changes in the rate of decrease in TBW and ECW coincided with weaning, and it was speculated that there was a direct relationship between the two events.     

Hemodialysis (HD) versus peritoneal dialysis (PD): latent overhydration in PD patients?

Data on the difference in fluid status between hemodialysis (HD) and peritoneal dialysis (PD) patients are scarce. Bio-electrical impedance analysis (BIA) is able to detect total body water (TBW) and its distribution in intracellular (ICW) and extracellular water (ECW). Echographic determination of the diameter of the inferior caval vein (VCD) provides information about the intravascular space (IVS). Nineteen PD-patients and 20 HD-patients in stable clinical condition were studied. In HD-patients a significant decrease in VCD, mean arterial pressure (MAP), TBW and ECW was noted due to ultrafiltration. Both ratios of VCD to ICW/ECW and of VCD to ECW/TBW decreased. No significant differences were found in these variables between PD-patients and HD-patients before HD. In both patient groups the measured variables pointed towards overhydration and the increased ratios both of VCD to ICW/ECW and VCD to ECW/TBW towards the storage of surplus of fluid in the intravascular space. It can be concluded that both PD-patients and HD-patients before HD have a surplus of fluid in the extracellular compartment, predominantly stored in the intravascular space.     

Is bioelectrical impedance spectroscopy accurate in estimating total body water and its compartments in elite athletes?

Background: Bioelectrical impedance spectroscopy (BIS) provides an affordable assessment of the body's various water compartments: total body water (TBW), extracellular water (ECW) and intracellular water (ICW). However, little is known of its validity in athletes.

Aim: To validate TBW, ECW and ICW by BIS in elite male and female Portuguese athletes using dilution techniques (i.e. deuterium and bromide dilution) as criterion methods.

Subjects and methods: Sixty-two athletes (18.5 ± 4.1 years) had TBW, ECW and ICW assessed by BIS during their respective pre-season.

Results: BIS significantly under-estimated TBW by 1.0 ± 1.7 kg and ICW by 0.9 ± 1.9 kg in relation to the criterion methods, with no differences observed for ECW. The values for the concordance correlation coefficient were 0.98 for TBW and ECW and 0.95 for ICW. Bland-Altman analyses revealed no bias for the various water compartments, with the 95% confidence intervals ranging from ? 4.8 to 2.6 kg for TBW, ? 1.5 to 1.6 kg for ECW and ? 4.5 to 2.7 kg for ICW.

Conclusions: Overall, these findings demonstrate the validity of BIS as a valid tool in the assessment of TBW and its compartments in both male and female athletes.     

Loss of fat,water, and protein during very low calorie diets and complete starvation

Summary The magnitude and composition of weight loss obtained in obese women on two forms of very low calorie protein-supplemented diets (Cambridge diet, Dresden drink) as well as by complete starvation has been investigated.With the VLCD, nitrogen equilibrium was reached on the 10th day of fasting, the cumulative nitrogen balance also being compensated. Nearly half of the body weight loss is due to loss of fat. In order to assess the benefit of fasting regimes, we propose to measure at least two parameters which are independent of each other, e.g., nitrogen balance and total body water. Both types of VLCD were equally effective, safe, and acceptable in achieving rapid body weight reduction.Abbreviations BMR basal metabolic rate - ECW extracellular water - ICW intracellular water - LBM lean body mass - TBW total body water - VLCD very low calorie diets     

Continuous monitoring of plasma,interstitial, and intracellular fluid volumes in dialyzed patients by bioimpedance and hematocrit measurements

Bioimpedance spectroscopy (BIS) permits evaluation of extra- and intracellular fluid volumes in patients. We wished to examine whether this technique, used in combination with hematocrit measurement, can reliably monitor fluid transfers during dialysis. Ankle to wrist BIS measurements were collected during 21 dialysis runs while hematocrit was continuously monitored in the blood line by an optical device. Extracellular (ECW) and intracellular (ICW) water volumes were calculated using Hanai's electrical model of suspensions. Plasma volume variations were calculated from hematocrit, and changes in interstitial volume were calculated as the difference between ECW and plasma volume changes. Because accuracy of ICW was too low, changes in ICW were calculated as the difference between ultrafiltered volume and ECW changes. Total body water (TBW) volumes calculated pre- and postdialysis were, respectively, 3.25+/-3.2 and 1.95+/-2.5 liters lower on average than TBW given by Watson et al.'s correlation. Average decreases in fluid compartments expressed as percentage of ultrafiltered volume were as follows: plasma, 18%; interstitial, 28%, and ICW, 54%. When the ultrafiltered volume was increased in a patient in successive runs, the relative contributions of ICW and interstitial fluid were augmented so as to reduce the relative drop in plasma volume.     

Use of bioelectrical impedance in hydration status assessment: reliability of a new tool in psychophysiology research.

Adequate hydration is crucial in maintaining optimal physical and mental functioning and the need for a fast and reliable hydration status assessment in behavioral medicine research has become increasingly important. The goal of this study was to determine the reliability of bioelectrical impedance assessment (BIA) in assessing total body water (TBW), extracellular water (ECW) and intracellular water (ICW) and to assess whether individuals can be reliably classified as being hypohydrated or hyperhydrated using lower and upper quartiles, respectively. TBW, ECW and ICW were assessed via BIA (Bodystat, Isle of Man, UK) in 52 male and 48 female college students on 2 separate days within 1 week. Results revealed strong test-retest reliability for TBW (r=0.983), ECW (r=0.972) and ICW (r=0.988) (all P's<0.001). Following the initial and follow-up assessments, participants were then classified as being either hypohydrated or hyperhydrated based on the percentage of body weight accounted for by TBW. Test-retest reliability of hydration status within classifications was then assessed by gender. Test-retest reliability was found for TBW, ECW and ICW among hypohydrated (r=0.985, r=0.972 and r=0.99, respectively) and hyperhydrated (r=0.994, r=0.989 and r=0.994, respectively) males (all P's<0.001). Significant test-retest correlations were also found for females classified as being hypohydrated (r=0.97, r=0.956 and r=0.976, respectively) and hyperhydrated (r=0.973, r=0.976 and r=0.976, respectively) (all P's<0.001). These findings suggest that hydration status, as indexed by bioelectrical impedance technique, is reliable across time and is also reliable within individuals who are chronically hyperhydrated or hypohydrated.     

Assessment of body composition in adolescent subjects with anorexia nervosa by bioimpedance

Our main goal was to test various impedance methods for measuring body composition in adolescents with anorexia nervosa (AN) during refeeding therapy. A specific objective was to compare the information provided by a foot-to-foot impedancemeter (FFI) with that supplied by a medical multifrequency impedancemeter and by dual X-ray absorptiometry (DXA). We have monitored 13 young AN subjects and 17 healthy controls of a similar age group using a Xitron 4200 multifrequency impedancemeter measuring extracellular (ECW) and total body water (TBW) volumes and a Tefal Bodymaster FFI measuring weight (W), fat-free-mass (FFM) and body fat mass (FM). This Tefal device has been modified to measure in addition ECW and TBW resistances permitting to calculate ECW and TBW volumes using appropriate algorithms. In addition FFM and FM were measured by DXA on AN subjects. FFM measured by the FFI and the Xitron in AN subjects were found to be respectively 7.8% and 4.5% lower than FFM measured by DXA. TBW measured by FFI was not significantly different from that measured by Xitron in AN subjects and in controls. ECW measured by the FFI was not significantly different from that measured by Xitron in controls, but was in AN subjects. The body cell mass to (height)2 ratio was found to be significantly different between AN subjects and controls. The modified FFI was found to be simpler and quicker to use than the Xitron, while giving similar information.     

Skeletal differences between black and white men and their relevance to body composition estimates

Skeletal differences exist between closely matched Black and White women, although it is unknown if similar differences also exist between Black and White men after controlling for age, body weight, and stature. The aim of this study was twofold: to test the hypothesis that Black men have greater bone mass, higher bone mineral density, and longer limbs compared to White men of similar age, weight, and height; and second, to establish if ethnic variation in skeletal characteristics has an impact on the models upon which three widely used methods for estimating total body fat are based. Twenty-four healthy Black men were matched by age (±5 years), height (±3 cm), and weight (±2 kg) to 24 healthy White men. Skeletal characteristics and body composition were studied using anatomical and compartment estimates derived by anthropometry, ³H₂O dilution, hydrodensitometry, whole-body ⁴⁰K counting, and dual photon systems. Black men had greater bone mineral mass (P = 0.007), higher bone density (P = 0.054), longer femurs (P = 0.002), longer anthropometric arm and thigh lengths (P = 0.001 and P = 0.002, respectively), lower spine to femur ratio (P = 0.004), and similar spine length (P = 0.271) compared to White men. Total body fat and fat-free body mass (FFM) were estimated in the men using a four-compartment model. Black and White men had similar total body fat, K (TBK), water (TBW), and FFM. Density of FFM and TBK/FFM were also similar between Black and White men, suggesting that current two-compartment hydrodensitometry and TBK models for estimating fat may not require adjustments for ethnicity. The TBW/FFM ratio, which is the main assumed steady-state relation for the two-compartment TBW method of estimating fat, was modestly increased (P = 0.05) in Black men (x? ± SD, 0.744 ± 0.018) compared to White men (0.732 ± 0.021). These results confirm that Black and White men differ significantly in some skeletal characteristics and these differences have implications in the study of both osteoporosis and human body composition. © 1994 Wiley-Liss, Inc.     

Distal versus proximal electrode placement in the prediction of total body water and extracellular water from multifrequency bioelectrical impedance

In 48 normal weight subjects, 25 females and 23 males, body impedance was measured at multiple frequencies. Two different electrode placements were used, one the commonly used distal electrode placement, in which the source electrodes are on the dorsal sides of the hand and foot and the sensor electrodes are on ankle and wrist, and a second placement, in which the sensor electrodes are placed more proximally, at the knee and elbow. Theoretically a proximal electrode placement could result in more precise estimates of body water compartments. Total body water (TBW) and extracellular water (ECW) were determined using deuterium oxide dilution and bromide dilution, respectively. The aim of the study was to investigate whether proximal electrode placement results in a more precise estimation of TBW and ECW using multifrequency impedance analysis. Correlation coefficients of impedance and the impedance index stature²/impedance) with TBW and ECW were not or were only slightly higher using proximal impedance values, resulting in slight improvement of the estimation error for TBW (0.13 kg) and ECW (0.04 kg). The differences between measured and predicted values (residuals) of TBW and ECW were not correlated with TBW and ECW, but they were correlated with body fat and body water distribution (ECW/TBW). These correlations did not differ between distal and proximal impedance measurements. It is concluded that proximal impedance measurements do not substantially improve the prediction of body water compartments. © 1995 Wiley-Liss, Inc.     

Body composition and body hydration in old age estimated by means of skinfold thickness and deuterium dilution.

In this study a group of 30 women and 30 men aged 60-90 years was examined. Body density was predicted from the sum of four skinfold thickness (SFT) as described by Durnin and Womersley (1974). Body composition, expressed as a percentage of total body weight as fat mass (FM) and fat free mass (FFM) was calculated by means of Siri's formula (Siri 1961). Total body water (TBW) was measured from the dilution of an oral deuterium dose and FFM calculated assuming a hydration of 73.2%. The FM% predicted from SFT showed a slight but not significant decreasing age trend from 28.3% to 25.4% in men, and from 40.3% to 37.8% in women. Body hydration (about 50% of body weight in men and 44% in women) remained constant throughout the age range. FFM obtained from TBW assuming a constant hydration of FFM, was found to be unchanged with age. FM% predicted from SFT was correlated with values obtained from TBW on an individual basis (R2 = 0.38; p less than 0.0001 in men and R2 = 0.31; p less than 0.002 in women), but the scatter was large. The Bland and Altman statistical analysis (Bland and Altman 1986) suggests that the discrepancy between the two estimates tends to be significantly more positive with increasing fatness of the subject. The assumption of a constant hydration of FFM between individuals and with advancing age was tested. The hydration of FFM was calculated as the ratio between TBW (from deuterium dilution) and FFM (estimated from SFT). The wide range of values (50% to 90%) suggests large inter-individual differences. The mean values were lower than commonly reported, and differed with age and sex. In men, FFM hydration steadily decreases with age from the 7th decade (70.2 +/- 7.7%) to the 10th decade (65.9 +/- 8.2%). Women showed higher average figures than those of men and a lower age-associated decline (72.5% and 68.5% respectively). Our results suggest that FFM hydration decreases with age, and this indicates the need to develop age-related correction factors in order to derive FFM from TBW in an elderly population.     

Multicompartment model of body composition assessment in Chinese-American adults

Using hydrodensitometry, dual energy x-ray absorptiometry, and deuterium dilution techniques, multiple compartment body composition assessment was performed on 29 adult Chinese-American men (n = 11) and women (n = 18). The purpose of the investigation was to determine if significant differences exist in the estimation of percentage of body fat (%BF) and fat-free mass (FFM), based on 2-, 3-, and 4-compartment models of body composition. Height, weight, and the body mass index (BMI) for the men were 170 cm, 63 kg, and 22 kg/m²; for the women, values were 161 cm, 59 kg, and 23 kg/m², respectively. Estimated values for %BF from density alone and density adjusted for TBW were not significantly different for either the men or women (20.5% vs. 18.8%) and (28.2% vs. 27.4%). However, %BF estimated from the 4-compartment model of density, TBW and BMC resulted in significantly lower values for both groups, 17.5% for men and 26.8% for women. The lack of a significant difference in %BF between density only and density adjusted for TBW indicates that TBW was within the accepted constancy value associated with hydrodensitometry. When density was adjusted for variation in both TBW and BMC, a significant decline occurred in the estimate of %BF for men, but not for women. The average TBW to FFM ratio was 0.75., 0.74, and 0.73 when using FFM values from 2-, 3-, and 4-compartment models, respectively. The average BMC to FFM ratio from two-, three-, and four-compartment estimates of FFM were 0.054, 0.053, and 0.052 for the men and 0.060, 0.059, and 0.059 for the women. The results suggest that Chinese-American men and women have similar TBW/FFM ratios, but the BMC/FFM ratio is higher in women than men. Am. J. Hum. Biol. 9:21–27 © 1997 Wiley-Liss, Inc.

1 This article is a US Government work and, as such, is in the public domain in the United States of America.

     

Effect of a moderately energy- and salt-reduced diet on body compartments and blood pressure control in obese men with mild hypertension

Ten middle-aged moderately obese men with untreated mild hypertension were studied during a 6-week weight maintenance period and a 9-week period on a diet containing 5 MJ when body mass decreased by 8.4 kg (SE 1.4). According to urinary sodium excretion there was a mean reduction of 89 mmol/day (SE 16) in sodium intake. Mean arterial pressure fell by 2.5 to 14.1 mmHg (95% confidence interval) which was correlated to the reduction of body mass. The sympathetic nervous activity diminished with decreasing noradrenaline excretion and heart rate. There were no changes in the renin-aldosterone system. Estimation of the body composition with a four-compartment model utilizing determinations of body mass, total body potassium and total body water (TBW) showed reductions of body fat (8.4 kg (SE 1.4] and body cell mass (BCM) (2.4 kg (SE 0.6], but not of TBW. Extracellular water (ECW) increased significantly as judged from ECW/BCM calculations. Plasma volume was determined by Evan's blue and did not change significantly. We suggest that the observed changes in body composition represent one aspect of the adjustment to a weight reducing diet, while blood pressure is lowered by another mechanism in the adaptive response to dieting, i.e. reduction in sympathetic nervous activity.     

Differences in the subcomponents of fat-free body in relation to height between black and white children

The individual subcomponents of fat-free body (FFB) in relation to height were investigated in 131 white (N = 85) and black (N = 46) males (MW, MB) and 108 white (N = 63) and black (N = 45) females (FW, FB), aged 8 to 18 years. Bone mineral content (BM), bone width (BW), and bone mineral index (BMI) were measured using photon absorptiometry; total body water (TBW) was measured by deuterium dilution; body density was measured by hydrostatic weighing, correcting for residual lung volume; and estimates of lean body mass (LBM) were made from total body potassium (⁴⁰K spectroscopy). The subcomponents of the FFB—BM, BW, BMI, TBW, and K—were regressed on the log of height to determine the exponent of the independent variable (Ht) that would most accurately predict the dependent variables (BM, BW, BMI, TBW, K) within gender and race. Regression equations were derived for each of the variables used to represent a subcomponent of the FFB on Ht. Significant (P < .05) racial differences were found in BW, with the MB having wider bones than the MW. Significant racial differences were observed in BMI with FB demonstrating a greater difference across height than FW. Racial differences in BM and TBW approached significance within the female sample. At heights greater than the mean of a typical pubescent child, the males had higher values for each of the variables, except for BMI, than did the females. The lower BMI values observed in males indicated that the rate at which male bones grow in width was greater than their rate of mineralization. Within the male sample, blacks had higher bone mineral than whites with the magnitude of these differences dependent on the variable under consideration. Within the female sample the blacks had greater amounts of BM and BMI in relation to height, while the whites had a greater amount of K. Therefore, the magnitude of the differences between blacks and whites in the subcomponents of the FFB are dependent on gender, stature, and the particular subcomponent of the FFB under consideration.     

Normal values of total body water in healthy Korean adults: comparison with data from western populations

To find reference total body water (TBW) values in healthy Korean adults, we performed single frequency bioelectrical impedance analysis on 2942 healthy adults and compared these data with those of normal western adults. Males were found to have greater TBW than females. Conversely, females were found to have greater percent fat (pFat) than males. In both sexes, body weight (BW) and TBW were significantly lower in age groups of < 30, 50 - 59, > or = 60 years than in the 40 - 49 years age group. pFats were significantly higher in age groups of 50 - 59 and > or = 60 years than in the 40 - 49 years age group. pFats were similar among age groups of < 30, 30 - 39, and 40 - 49 in both sexes. In all age groups, pFats were significantly higher in females than in males. TBW was significantly correlated with BW, height (HT), fat mass, and body mass index (BMI) in both sexes. There was a significant correlation between TBW and age in males(r=-0.15, p=0.00), but not in females (r=-0.02, p=0.45). On linear regression analysis, TBW values were independently associated with BW, HT and age in males and were independently associated with BW and BMI in females. In all age groups, Korean males and females had lower mean TBW than in Western populations. However, this difference was greater in males than in females. In summary, we represented the contemporary normal TBW data in healthy Korean adults. At present, there are no national reference data relating TBW in Korea. We hope the results of this study will be useful as the baseline data for the evaluation of hydration and nutritional status in healthy and ill adults, including end-stage renal disease (ESRD).     

Vital capacity in trained and untrained healthy young adults in the Netherlands

Summary Slow inspiratory vital capacity was measured in 226 healthy young adults, aged from 17 to 35 years. The group included 119 men and 107 women, 87 trained subjects, 71 untrained subjects who intended to take part in a training program for competitive rowing, and 68 untrained subjects who never took part in any competitive sport.The vital capacity increased with height, weight, fat-free mass, height×fat-free mass, and height-independent fat-free mass, with men having significantly higher vital capacities than women of the same height or weight. In both males and females vital capacity showed the best relation with height×fat-free mass (correlation coefficients are 0.78 and 0.57 respectively). Multiple regression on vital capacity with height, weight, fat-free mass, height×fat-free mass, height-independent fat-free mass, percentage body fat, and age increased the correlation coefficient only slightly (0.80 and 0.59 respectively).The subjects had vital capacities that were much higher than those predicted for them by equations originating from the USA. There was no difference between the observed vital capacities and those predicted by equations originating from Europe. There is a difference in vital capacity between the European subjects studied and subjects of similar height studied in the USA. This implies that equations derived from subjects in the USA cannot be applied to European subjects.From our results we conclude that vital capacity is not increased by physical activity.We derived one simple equation that can be used to predict the vital capacity for both male and female, trained and untrained young adults, who have a similar genetic background to our subjects.     

Hypoalbuminemia is a marker of overhydration in chronic maintenance patients on dialysis

Hypoalbuminemia is an important risk factor for increased morbidity and mortality in patients on dialysis. Hypoalbuminemia is usually attributed to malnutrition or a state of chronic inflammation. However, hypoalbuminemia could result from hemodilution caused by chronic volume expansion. We prospectively evaluated 142 patients on chronic dialysis for 12 consecutive months (mean age: 62 +/- 14 years; 41% women, 37% African American, 43% diabetic, 27% peritoneal dialysis). Intracellular (ICW) and extracellular (ECW) water content was estimated using single frequency bioelectrical impedance. Values in each albumin grouping (group 1, < 3.5 g/dl; group 2, 3.5-4.0 g/dl; group 3, > 4.1 g/dl) are expressed as annual mean +/- SEM. Group 1 patients had lower body weight, body mass index, blood urea nitrogen, serum creatinine, dietary protein intake, and ICW content than those in groups 2 and 3. ECW was significantly increased in group 1 when compared with groups 2 and 3 (p < 0.001). A significant correlation was found between ECW and serum albumin concentration (R = 0.2230; p < 0.0001). Resistance and reactance were decreased in group 1 when compared with groups 2 and 3 (p < 0.05 and 0.001, respectively), causing the resultant bioimpedance vector to move away from the normal population range into the overhydration boundaries. We conclude that, in addition to malnutrition and chronic inflammation, overhydration is a contributor to hypoalbuminemia in patients on chronic dialysis.     

Characteristics of body fat, body fat percentage and other body composition for Koreans from KNHANES IV

Accurate measurement of fat mass has become increasingly important with the increasing incidence of obesity. We assessed fat and muscle mass of Koreans with the Korea National Health and Nutrition Examination Survey IV (KNHANES IV). We studied 10,456 subjects (aged 20 to 85 yr; 4,476 men, 5,980 women). Fat and muscle mass were measured by dual-energy x-ray absorptiometry. Reference values of body compositions were obtained using the LMS method. The fat mass index (FMI, body fat mass/height(2); kg/m(2)) of Korean men did not correlate with age (P = 0.452), but those of Korean women (P < 0.001) did. The ratio of percentage of fat in the trunk and legs was positively related with age in both the genders. The appendicular lean mass/height(2) (kg/m(2)) of Korean men was negatively related to age (P < 0.001). In women, this ratio increased with age (P < 0.001). When we defined obesity according to the FMI classification, the rates of obesity were 6.1% (FMI > 9 kg/m(2)) in men and 2.7% (FMI > 13 kg/m(2)) in women. It is concluded that the muscle mass decreases and obesity increases with aging in Korean men, whereas both fat mass and obesity increase with aging in Korean women.     

Total body water,extracellular water,plasma volume,and total body potassium in cirrhosis of the liver

Summary Extracellular water (EWC; 82-bromide), total body water (TBW; 3-THO), intracellular water (ICW=TBW-ECW), plasma volume (PV; 51-Cr), and total body potassium (TBK; 40-K) were studied in patients with cirrhosis of the liver (n=12) and in controls (n=12). ECW (39%), TBW (28%), ICW (19%), and PV (24%) increased, TBK (28%) however, decreased in cirrhosis. The results indicate that it is less the lean body mass, but rather the intracellular potassium concentration that is lowered (cirrhosis: 84±21 mmol/l ICW; controls: 115±23 mmol/l ICW). Decreased potassium per cell (mmol) and increased intracellular water are discussed as possible reasons for this. The correlation between TBK (%) and serum potassium (mmol/l) was found to ber=0.56 (p<0.002). Correlations between the biochemical parameters gamma-globulins, cholin esterase, serum sodium and serum albumin (g/l PV) and characteristic fluid disturbances in cirrhosis are highly significant whereas albumin (g/kg bodyweight) was the same in both groups. We can support the overflow theory of ascites formation [19].This paper is part of a medical doctorate of O. Schober