Showing papers on "Body water published in 1991"

Blood volume: its adaptation to endurance training.

Abstract: Expansion of blood volume (hypervolemia) has been well documented in both cross-sectional and longitudinal studies as a consequence of endurance exercise training. Plasma volume expansion can account for nearly all of the exercise-induced hypervolemia up to 2-4 wk; after this time expansion may be distributed equally between plasma and red cell volumes. The exercise stimulus for hypervolemia has both thermal and nonthermal components that increase total circulating plasma levels of electrolytes and proteins. Although protein and fluid shifts from the extravascular to intravascular space may provide a mechanism for rapid hypervolemia immediately after exercise, evidence supports the notion that chronic hypervolemia associated with exercise training represents a net expansion of total body water and solutes. This net increase of body fluids with exercise training is associated with increased water intake and decreased urine volume output. The mechanism of reduced urine output appears to be increased renal tubular reabsorption of sodium through a more sensitive aldosterone action in man. Exercise training-induced hypervolemia appears to be universal among most animal species, although the mechanisms may be quite different. The hypervolemia may provide advantages of greater body fluid for heat dissipation and thermoregulatory stability as well as larger vascular volume and filling pressure for greater cardiac stroke volume and lower heart rates during exercise.

Glutamine-enriched intravenous feedings attenuate extracellular fluid expansion after a standard stress.

Abstract: A double-blind, randomized controlled trial was performed to determine the effect of glutamine (GLN)-enriched intravenous feedings on the volume and distribution of body fluids in catabolic patients. Subjects with hematologic malignancies in remission underwent a standard treatment of high-dose chemotherapy and total body irradiation before bone marrow transplantation. After completion of this regimen, they were randomized to receive either standard parenteral nutrition (STD, n = 10) or an isocaloric, isonitrogenous nutrient solution enriched with crystalline L-glutamine (0.57 g/kg/day, GLN, n = 10). Extracellular water (ECW) and total body water (TBW), determined by bromide and heavy water dilution techniques, were measured before the conditioning treatment and after termination of the intravenous feedings that were administered for 27 +/- 1 days. In addition electrical resistance (R, in ohms, omega) and reactance (Xc, omega) of the body to a weak alternating current were measured at these time points. Both study groups were comparable for age, weight, height, sex, and diagnosis. Initial TBW was highly related to electrical resistance (r = -0.93, p less than 0.001). After conditioning therapy, bone marrow infusion, and intravenous feedings, a 20% expansion in ECW was observed in the STD group (ECW: 18.0 +/- 1.1 L vs. 14.9 +/- 1.0, p = 0.012), and this fluid retention was associated with a marked decrease in electrical resistance (R: 514 +/- 28 omega vs. 558 +/- 26, p less than 0.05). In contrast the extracellular fluid compartment in patients receiving GLN-supplementation did not change (ECW: 15.8 +/- 0.9 L vs. 15.4 +/- 0.8, p = 0.49), and the body's resistance was maintained (R: 552 +/- 27 omega vs. 565 +/- 23, p = 0.42). Expansion of ECW could not be related to differences in fluid or sodium intake, or to the use of diuretics or steroids. Patients receiving the STD solution, however, exhibited a greater number of positive microbial cultures (p less than 0.01) and a higher rate of clinical infection compared with the GLN patients (5/10 vs. 0/10, p less than 0.05); the fluid expansion in infected STD patients was greater compared with uninfected individuals (delta ECW: + 5.0 +/- 1.4 vs. 0.7 +/- 0.5, p = 0.007). In this model of catabolic stress, fluid retention and expansion of the extracellular fluid compartment commonly observed after standard total parenteral nutrition can be attenuated by administering glutamine-supplemented intravenous feedings, possibly by protecting the host from microbial invasion and associated infection.

Body composition in biological anthropology

Abstract: Preface 1. Introduction 2. Epidemiological indices, anthropometric and cadaver estimates of body composition 3. Determination of body fat 4. Determination of body water 5. Determination of lean tissue 6. Estimation of bone mass 7. Regional differences of body composition 8. Developmental changes, growth and aging 9. Genetic influences upon body composition 10. Environmental influences 11. Pathological disturbances of body composition 12. Human adaptability and body composition Glossary References Index.

Changes in body fluid compartments during a 28-day bed rest.

Abstract: Serial isotope measurements were used to obtain measurements of the body fluid responses of 10 22-29-year-old men during 28 d of simulated microgravity (bed rest). The subjects were maintained on a controlled metabolic diet for 7 d before the study, during 14 d of ambulatory control, 28 d of horizontal bed rest, and 14 d of ambulant recovery. Fluid compartments were measured on control days 1 and 9, bed rest days 2, 14, and 28, and recovery days 7 and 14. By day 2 of bed rest, plasma volume and extracellular volume (ECV) decreased significantly by an average 209 and 533 ml, respectively. Red cell volume and total body water (TBW) decreased more slowly, with average losses of 128 and 1316 ml, respectively, after 28 d of bed rest. Early in the bed rest, TBW loss was mostly from the ECV. Thereafter, the TBW deficit was derived from the intracellular compartment, which decreased an average of 838 ml after 28 d. These results suggest losses from all fluid compartments during bed rest, with no evidence of restoration of ECV after 1-2 weeks.

Importance of Volume Factors in Dialysis-Related Hypertension

Abstract: In order to evaluate the influence of volume factors on blood pressure (BP) in 20 chronic hemodialysis patients, we studied the effect of total body water, interdialytic weight gain, hematocrit, erythropoietin, and blood viscosity on BP with predialysis and 24 h ambulatory measurements. There was a significant correlation between weight gain and mean BP before dialysis (r = .48, p = .02), but not with mean BP during the day before dialysis (r=0.08, p = .7). On the contrary there was no correlation between percentage of total body water (TBW %) and BP before dialysis (r = .08, p = .7), but a significant correlation with mean BP during the day before dialysis (r = .57, p = .01). The other variables had no influence on BP. The data suggest that BP before dialysis is more related to acute extracellular volume changes, and that chronic hypertension is more related to total body water. TBW measurements can possibly be used as a guideline in the treatment of dialysis patients with hypertension.

Measuring body fat: calibrating the rulers. Intermethod comparisons in 389 normal Caucasian subjects.

Abstract: A systematic study of 389 normal Caucasians stratified for sex and age compared all of the traditional methods for measuring fat: body water, underwater weighing, body potassium, and anthropometrics and the newer methods of dual-photon absorptiometry, bioimpedance analysis, and total body electrical conductivity. Measurements by all methods are highly intercorrelated, but methods differences show the population means for fat percent to range from 26 to 35% of body weight across eight methods. All methods show increasing fat (as % body weight) with age in both sexes but vary in secular slope. The goal of this report is to provide direct translations between each of the eight methods. Intermethod comparison equations are given as simple linear regressions by using each method both as dependent and independent variable for each sex, permitting translation for results by any method to any other.

Body water measurement in growth disorders: a comparison of bioelectrical impedance and skinfold thickness techniques with isotope dilution.

Abstract: Total body water was estimated as part of the assessment of body composition in children with growth disorders, using the newly commercially available method of bioelectrical impedance. This was undertaken to compare the precision and accuracy of the results with those derived from skinfold thickness against measurement of stable isotopically labelled water (H2(18)O) dilution as a standard. The comparisons were carried out to see to what extent the impedance method could be applied with confidence to assessment of children with growth disorders. Total body water was derived from impedance (I) using an association with height (Ht2/I). Impedance and skinfold thickness estimates of total body water were equally precise when compared with values obtained from H2(18)O dilution (limits of agreement -1.9 to +1.3 and -1.7 to +2.0 kg respectively). The mean intraobserver coefficient of variation for repeat measurements of impedance was 0.9% compared with 4.6% for skinfold thickness with an interobserver coefficient of variation for impedance of 2.8%. Bioelectrical impedance estimation of body composition is likely to be of value in the growth clinic when expertise in measurement of skinfold thickness is limited or repeated measurements are to be undertaken by different observers.

Estimation of total body water by bioelectrical impedance analysis in blacks.

Abstract: Several differences exist between the body composition of blacks and whites. This study was designed to investigate the applicability of bioelectrical impedance analysis (BIA) in blacks, using prediction equations developed in whites. A multiple regression equation developed on 79 white adults, using deuterium oxide dilution space total body water (D2 O-TBW) as the reference method, was prospectively applied to 88 blacks aged 19-50 years. Although the regression line of D2 O-TBW on BIA-TBW was not significantly different from the line of identity (r = 0.98, SEE = 1.71 liters), mean TBW was significantly underestimated by 0.84 liter. Other BIA equations from the literature also underestimated D2 O-TBW in blacks, except for an equation developed on a mixed black and white population. Multiple regression analysis on the data of the black and white subjects combined showed that race, offered as a separate independent variable, improved the correlation with D2 O-TBW slightly but significantly (P < 0.01). It was concluded that BIA may be valuable in the assessment of body composition in blacks as well as in whites. In this study a small underestimation of TBW occurred in blacks, using (BIA) equations from whites. This may be due to racial differences in body composition or to factors unrelated to ethnicity.

Body impedance measurements during dialysis.

Abstract: Changes in body weight in relation to changes in body impedance were studied in six male and four female patients before and during dialysis. Before dialysis, fat-free mass from skinfolds was 46.5 +/- 6.8 kg, and total body water calculated from bio-electrical impedance was 36.9 +/- 5.2 kg. Body water expressed as a percentage of fat-free mass was calculated to be 80 +/- 4%. Mean weight loss, which was assumed to be only loss of water, was 2.7 +/- 0.7 kg. Total body impedance increased by 80 +/- 16 omega from 495 +/- 39 omega to 575 +/- 47 omega. Weight loss and increase in body impedance were highly correlated (r = -0.91, P less than 0.001). However, based on prediction formulas for total body water from bio-electrical impedance, the observed weight (water) loss should be associated with an increase in impedance of only 39 +/- 11 omega. It is concluded that the impedance value before dialysis is a relatively low value, due to the low specific resistivity of the excess of extra-cellular water in the body before dialysis. As a consequence, prediction formulas for body composition from bio-electrical impedance, developed in normal hydrated subjects, overestimate body composition (total body water, fat-free mass) in subjects with oedema.

The Use of Tritiated Water to Determine Protein and Lipid Utilization in Fasting Birds: A Validation Study in Incubating Great-Winged Petrels, Pterodroma macroptera

Abstract: To obtain reference data for the estimation of energy metabolism from body mass (BM) loss in long-term fasting Procellariiformes, we determined the loss of water, lipid, and protein by analysis of body composition in great-winged petrels, Pterodroma macroptera, during the incubation fast. We also examined the validity of the use of total body water (TBW) loss alone to calculate protein and lipid loss. Body composition analysis showed that, during the major part of the 17-d fast, water, lipid, and protein contribute a constant 35.7%, 50.8%, and 13.5%, respectively, of BM loss. The energy content of lipid (adipose triglycerides) was found to be 39. 4 kJ/g. The energy equivalent of BM loss was 22.3 kJ/g; 90% and 10% of energy originated from lipid and protein utilization, respectively. The 376% contribution of water loss to BM loss, estimated from measurement of TBW by using tritiated water, was similar to that obtained by direct analysis of body composition. The loss of protein and lipid was estimated from ...

Anthropometry and obesity in myelomeningocele

Abstract: Anthropometric data on 110 myelomeningocele (MMC) subjects in relation to age, sex, level of lesion and ambulation were studied to investigate growth and the occurrence of obesity in MMC. In 52 subjects, indices of obesity were validated against body composition analysis of total body fat (%BF) using body potassium and body water techniques. Most subjects were short and light compared to reference data and became relatively shorter and heavier with age. Overall trunk growth was not affected by the level of lesion, but sitting height was affected by kyphoscoliosis. Arm spans were similar to reference data, but were significantly greater in wheelchair users. Leg length was greatest in those who walked. Body composition data showed excess adipose in many MMC subjects, this tendency increasing with age. When correlated with %BF determined from body composition analysis, common clinical indices of obesity had variable r values (wt/ht2 0.78; wt/sitting ht2 0.77; upper arm fat area 0.75; triceps skinfold 0.74; wt/arm span2 0.68, with the 4 skinfold method correlating best, 0.82). Anthropometric measures, taken with cognizance of level of disability and mobility, can accurately assess body growth and the occurrence of obesity in MMC. The influence of ambulatory activity in promoting normal growth is emphasized.

Metabolic changes observed in astronauts

Abstract: Study of metabolic alterations that occur during space flight can provide insight into mechanisms of physiologic regulation. Results of medical experiments with astronauts reveal rapid loss of volume (2 L) from the legs and a transient early increase in left ventricular volume index. These findings indicate that, during space flight, fluid is redistributed from the legs toward the head. In about 2 days, total body water decreases 2 to 3%. Increased levels of plasma renin activity and antidiuretic hormone while blood sodium and plasma volume are reduced suggest that space flight-associated factors are influencing the regulatory systems. In addition to fluid and electrolyte loss. Skylab astronauts lost an estimated 0.3 kg of protein. Endocrine factors, including increased cortisol and thyroxine and decreased insulin, are favorable for protein catabolism. The body appears to adapt to weightlessness at some physiologic cost. Readaptation to Earth's gravity at landing becomes another physiologic challenge.

The effect on body composition and exercise performance of home parenteral nutrition when given as adjunct to chemotherapy of testicular carcinoma

Abstract: This study has evaluated whether long-term and permanent total parenteral nutrition (TPN) can protect body composition and exercise capacity during iterated courses of chemotherapy (PVB) in men with testicular carcinoma Thirty-three men were randomly allocated by means of a computer based algorithm to receive either TPN (at hospital and home) during the entire chemotherapy period or to rely on spontaneous oral intake only Nutrition status was assessed by measurements of whole body nitrogen (neutron activation), total body potassium, body water, urine creatinine excretion, loco-regional body nutrition indexes (AMC, TSF) and biochemical plasma concentrations (albumin, thyroid hormones) Whole body respiratory gas exchanges were measured during resting, submaximal and maximal exercise TPN was prescribed on an individual basis in all study patients to cover 150% of their measured caloric need; nitrogen was given as 02 g N kg-1 day All individuals were allowed to eat freely throughout the study TPN patients were in overall positive energy balance (+850 Kcal day-1), while the control group was in negative balance (-532 Kcal day-1) This led to weight gain in the TPN group (+22 +/- 10 kg) while the control group lost significant weight (-42 +/- 11 kg) The average spontaneous oral caloric intake was 1014 +/- 153 Kcal day-1 in the TPN group and 1484 +/- 200 Kcal day-1 in the control group; total protein intake corresponded to 15 g protein kg day-1 in the TPN group and 07 kg day-1 in the control group(ABSTRACT TRUNCATED AT 250 WORDS)

Total body water and body composition in phalaropes and other birds

Abstract: Contrary to some reviews, total body water (TBW) may fall below the expected value of about 65% in birds if measured as a percentage of total body mass. However, water constitutes a relatively stable proportion (659%-70%) of body composition when measured as a percentage of lean body mass (LBM). We demonstrate this by using data from two migratory phalaropes (Phalaropus tricolor and Phalaropus lobatus), which exhibit inverse relationships between TBW and body mass and between TBW and fat content. As the phalaropes fatten before migration, lipids increase but not at the expense of water, which also increases with gains in lean tissue. The gain in lean dry mass with body size is also correlated with migration. Because absolute water increases with body mass, TBW is a poor measure of hydration; however, because of the inverse relationship between TBW and fat, TBW can predict body fat accurately if a calibration curve is first generated. We provide equations that predict fat content in both species of phalaro...

Impedance electrodes positioned on proximal portions of limbs quantify fluid compartments in dogs.

Abstract: Body resistance and reactance to the conduction of an alternating electrical current were measured using electrodes attached to distal and proximal portions of limbs in anesthetized dogs. Body impedance was calculated from these measurements obtained at 30-min time intervals during a control period and after intravenous administration of 0.9% saline. Extracellular (ECW) and total body water (TBW) were determined by bromide and heavy water dilution techniques, respectively. Baseline impedance obtained from proximal electrodes was related to ECW (r = 0.95, P less than 0.001) and TBW (r = 0.80, P less than 0.02). After saline infusion, proximal electrodes detected a significant fall in impedance (P less than 0.001), whereas distal electrodes did not (P = 0.06). Furthermore, ECW and TBW could be estimated from the drop of proximal impedance after this bolus infusion (r = 0.82, P less than 0.02, and r = 0.86, P less than 0.01, respectively), but not from distal impedance measurements. Proximally placed impedance electrodes are superior to traditionally used distal electrodes for assessment of body fluid changes in the dog.

Body composition in Chinese subjects: comparison with data from North America.

Abstract: A multiple tracer dilution method measuring total body water, extracellular water, plasma volume, and red cell volume was used to study body composition. Healthy Chinese subjects were compared to a group of Chinese patients with various newly diagnosed gastrointestinal disorders scheduled for elective operation. Compositional data obtained from these groups showed no significant differences in compartmentalization, suggesting absence of major changes during the early stages of certain gastrointestinal diseases. In addition, healthy Chinese subjects were compared to a group of healthy Americans previously evaluated by similar dilutional methods. In males, body weight (kg) differed considerably (Chinese=62.1±2.0 versus American = 72.5±4.1,p<0.02) and could be explained by alterations in body fat (Chinese=12.4±1.3 versus American=19.2±2.2,p<0.02) and extracellular water (Chinese=14.4±0.5 versus American=16.8±0.8,p<0.02). Functional tissue (“body cell mass”) was similar in the 2 groups which suggested that Chinese have comparable body composition without an additional fat burden. The multiple tracer technique using deuterium oxide, sodium bromide, Evans dye, and Cr 51 for body compositional assessment is accurate but expensive and laborious. Therefore, equally precise but more economical bedside methods are needed for routine compositional analysis.

Reduction in plasma protein does not affect body water content in fetal sheep.

Abstract: We performed this study to determine if isolated hypoproteinemia and low colloid osmotic pressure cause formation of fetal edema. We successfully operated on six sets of twin fetal sheep at 114 d gestation to insert catheters into arteries and veins of both fetuses, allowing us to chronically perform partial exchange transfusions. One twin underwent protein reduction by repeated partial exchange transfusion over 3 d, and the other twin underwent simultaneous sham procedures. We removed an average of 18 g of protein, causing a 41% decrease in plasma protein concentration and a 44% decrease in colloid osmotic pressure. Vascular pressures, heart rate, hematocrit, plasma osmolarity, arterial pH, and arterial PO2 were not affected by protein reduction or by sham procedure, whereas PCO2 increased by a small amount in both groups. At autopsy, none of the fetuses in either group were edematous. Measurements of total body water by the wet to dry method, chloride space, and amniotic and allantoic fluid volumes were similar in both groups. We conclude that hypoproteinemia of a short duration does not affect the body water content of fetal sheep.

Measuring the lipid content of live animals using cyclopropane gas

Abstract: The cyclopropane technique was validated, and it accurately estimated the lipid mass of six pond turtles (Trachemys scripta). This technique provided more accurate estimates of lipid mass and lipid-free mass (by difference) than other nonfatal techniques. This technique was accurate despite the turtles' low lipid contents (0.71-3.5% of body mass), variable water contents (65-74% of body mass), and variable body temperatures (approximately 23-31 degrees C). A computer model of the cyclopropane technique revealed that an analytical error of 1% in variables measured (e.g., body water content and body temperature) may cause errors of less than 1-6% in lipid estimates.