Showing papers on "Body water published in 1974"

Body fat assessed from total body density and its estimation from skinfold thickness: measurements on 481 men and women aged from 16 to 72 years

Abstract: The fat content of the human body has physiological and medical importance. It may influence morbidity and mortality, it may aIter the effectiveness of drugs and anaesthetics, and it may affect the ability to withstand exposure to cold and starvation. Thus the measurement of the total body fat provides useful information. In many people, but by no means everyone, a moderately satisfactory estimate of the body fat content can be obtained from the height and weight. However, for more precise evaluation several methods are available which give a reasonably accurate measure of body fat both in normal subjects and in individuals with unusual body builds. Most of these methods are based on the assumption that the body can be considered to consist of two compartments of relatively constant composition but which are distinctly different; these compartments are: (I) the body fat, which includes the entire content of chemical fat or lipids in the body, and (2) the fat-free mass (FFM), which includes all the rest of the body apart from fat. The body fat compartment is anhydrous, contains no potassium and has a fairly constant density of about 0.90 x 103 kg/m3. The fat-free compartment on the other hand probably has a fairly constant density of about 1.10 x 103 kg/m3, a potassium content of about 68 mequiv./kg in males (about 10% less in females) and a water content of about 720 g/kg. Thus measurement of body density or of total body K or of total body water allows a calculation of the relative proportion of these two compartments in the body and therefore also of the total fat content. The accuracy of these measures, however, is limited by the variability of the composition and density of the fat-free compartment in different individuals. In particular, individuals with a relatively high or

A noninvasive approach to body composition in the neonate: dynamic skinfold measurements.

Abstract: Extract: Midtricipital (MT) and subscapular (SS) skinfolds were measured within 24 hr of birth in 23 normally grown mature (NG-M); 23 normally grown premature (NG-P); 6 intrauterine growth-retarded mature (IGR-M); and 7 intrauterine growth-retarded premature (IGR-P) infants. A rapid initial decrease in measured skinfold thickness (SFT) occurred after application of a Harpenden caliper, but readings stabilized by 60 s (SFT60). Measurements were recorded at 15 and 60 s. The difference between 15− and 60-s readings was expressed in percentage of the 15-s reading (percentage ΔSFT). The amount of subcutaneous fat, estimated from the SFT60 measurements, was affected by duration of gestation in the NG-M and NG-P and the IGR-M and IGR-P groups. In both NG groups, good linear correlations with birth weight (r = 0.852 at MT and 0.874 at SS, P < 0.001) and with gestational age (r = 0.842 at MT and r = 0.804 at SS, p < 0.001) were evident. Values for intrauterine growth-retarded infants deviated markedly from the mean SFT60 expected for their gestational age. Percentage ΔSFT was affected by duration of maturation but not by impaired intrauterine growth. It correlated with gestational age (r = −0.777 at MT and −0.773 at SS, P < 0.001) and with maximal postnatal weight loss (r = 0.579 at MT and 0.553 at SS, P < 0.001) in all groups and with birth weight in the premature groups only (r = −0.479 at MT and −0.520 at SS, P < 0.01). The similarity of these trends with those of direct extracellular water measurements suggested that percentage ΔSFT may be an estimate of subcutaneous interstitial water. Speculation: Changes in body composition during fetal life include fat deposition in the subcutaneous and internal body stores and a decrease in the proportion of body weight occupied by water. Intrauterine growth retardation results in lower fat stores and expansion of all body water compartments. The present data suggest that skinfold thickness recorded 60 s after caliper application and the difference between the 15-and 60-s readings provide estimates of fat stores and subcutaneous interstitial water, respectively. Caliper skinfold measurements can therefore be used for noninvasive studies of perinatal body composition and nutrition.

Prediction of Body Composition in Live Sheep

Abstract: New and published data on the chemical composition of 149 Merino and Merino crossbred sheep covering a wide range of age were used to derive regressions of body water, protein, ash and fat on parameters measured in the live animal. Allometric models were tested with fasted liveweight (W), tritiated water space (T) and maturity (M) as predictors, maturity being the age of the sheep as a proportion of the age at which mature size is reached. For all body components the inclusion of maturity in the following equations substantially reduced the residual standard deviation (RSD), compared with allometric or multiple linear regression models that included only W and T as predictors. In addition it largely eliminated bias from the predicted values for the six separate groups of sheep from which the data were obtained. Total body water (kg) = 1.179T0.926M0.031 (RSD = p0.354) Protein in empty body (kg) = 0.408 W0.708M0.092 (RSD = p 0.264) Ash in empty body (kg) = 0.305 W0.460M0.290 (RSD = p 0.100) Fat in empty body (kg) = 0.117(W – T)1.592M-0.225 (RSD = p 0.444) It is suggested that in future work a measure of skeletal size in the live animal may increase the precision of these equations.

The effect of route of dosing and method of estimation of tritiated water space on the determination of total body water and the prediction of body fat in sheep

Abstract: SUMMARY Eight mature female sheep were offered a ration which maintained body weight constant during a 20-week period. During the final 10 weeks a comparison was made in each animal of the pattern of equilibration and urinary losses of tritiated water during 8 h after dosing by four different routes. These were intravenous, intraperitoneal, intraruminal and a combination of the intraperitoneal and intraruminal routes. Tritiated water spaces were calculated from (a) the 8-h plasma specific activity and (b) by extrapolation to zero time of the plasma specific activities during the 7 days after injection. At the end of the experiment the fat and water contents of the bodies of the sheep were determined directly. Complete equilibration of tritiated water between plasma and rumen water was not achieved in all animals 8 h after intravenous or intraperitoneal injection but was when the rumen was primed by the combination of intraperitoneal and intraruminal dosing. After intraruminal dosing equilibration was not achieved in any animal within 8 h of dosing. Urinary losses of marker were lower after intraruminal dosing but otherwise averaged 4–5 % of the dose/1 urine. This was equivalent to 0·3–6·7% of the dose for individual sheep. Errors resulting from incomplete equilibration and urinary loss of marker did not influence the efficiency of prediction of total body water from tritiated water space. The multiple correlation coefficient relating body fat with empty body weight and its water content was very high (r = 0·99). Errors introduced into this relationship by the inclusion of gut water in the prediction equations were apparently of a similar magnitude to those resulting from the errors in the estimation of tritiated water space. The extrapolation method for the determination of tritiated water space was shown to have the same accuracy as equilibration techniques under these controlled dietary conditions.

Effect of oral contraceptives on body water and electrolytes.

Abstract: The effects of sequential oral contraceptives on intracellular and extracellular body water exchangeable body potassium sodium and chloride and serum electrolyte values in 14 patients and 5 control subjects were studied. Measurements were made at midcycle and end-cycle by radioisotopic dilution and radioactivity-counting techniques. Body composition parameters for midcycle and end-cycle showed no change though there was a significant increase in body sodium between the patients and controls (p less than .01) which was not reflected in serum values. Serum electrolyte values did not change significantly in either group. Body water and intracellular water increased and exchangeable chloride decreased in control subjects at midcycle. The results indicate that the increased body sodium which is most likely induced by estrogen has a stabilizing effect on body water since body water fluctuations were less in the contraceptive group than in the controls. Since the increased sodium levels may be implicated in certain oral contraceptive side effects it is recommended that the prescription of oral contraceptives to patients with cardiac or renal disorders or with hypertension be cautiously undertaken.

Interstitial fluid pressure and vasomotor responses in bats.

Abstract: REAVES, TROY ALBERT, WILLIAM C. HARTNER, AND JAMES EDWARD HEATH. Interstitial jluid pressure and vasomotor responses in bats. Am. J. Physiol. 226(Z) : 353-356. 1974.-Using the cottonwick technique, control values of interstitial fluid pressure (IFP) averaged 6.1 cmHz0 in Eptesicus fuscus and 12.0 cmHe0 in Myotis Zucifu~us. Maintenance of a near-normal body temperature (Tb) stabilized the IFP. During body heating, vasodilation of the wing occurred at a mean Tl, of 35.5OC in E. fuscus. Following vasodilation, the wing IFP increased an average of 5.1 cmHp0. Interstitial fluid pressure in actively struggling E. fuscus was 1.1 cmHz0 more negative than in the same bats while calm. Rats were used as a control animal for the experimental procedure. The mean IFP in albino rats was -3.9 cmHz0. A mean IFP of 5.0 cmHz0 was recorded from ground squirrels.

Unified method for serial study of body fluid compartments

Abstract: Methods for the simultaneous determination of equilibrium space of I-125/RISA(radio-iodinated serum albumin) (plasma volume), Cr-51 red cell mass, Br-82 space (extracellular fluid volume), and tritiated water space (total body water) are described. Determinations were made on two occasions separated by a 1 week interval in 43 healthy young men who were on a strict metabolic diet. Hourly samples were taken for 6 hours after injection of the radionuclides. Correlation of these values to the inscribed exponential disappearance curve was high. In 15 subjects, earlier and more-frequent sampling led to no improvement in the accuracy of estimation of the I-125/RISA space. Use of this method gave results in 12 subjects for Br-82 space and in 11 subjects for tritiated water space which were not significantly different from those obtained by correction for urine loss.

Body Composition in Alcoholic as Compared to Control Individuals

Abstract: Height, weight, total body potassium, exchangeable sodium, bromide space, total body water, and concentrations of sodium, potassium, and chloride in plasma were measured in control subjects and ind...

Water metabolism in grazing cattle

Abstract: Body water cantent and water turnover were measured in lactating and dry cows grazing clover-dominant pastures. Among 12 pairs of identical twins there was a closer within-twin relationship of body weight and body water content than water turnover. Water turnover was significantly correlated with body water content and milk production. Herd average for the half-life of water was 2.0–2.4 days for lactating cows and 2.8–3.3 days for dry cows. No relationship was found between water turnover and the susceptibility of cows to bloat. During severe bloat, cows dosed with anti-bloat had higher water turnovers and lower bloat scores than their untreated twins.

Body composition in uremic rats

Abstract: Body composition has been studied in uremia to assess state of nutrition and hydration. However, compositional data, chiefly gathered by measurement of fluid compartments, has not been collated with actual organ weights. This was studied in young, growing male Sprague-Dawley rats made uremic (average BUN 100mg%) by partial nephrectomy. Extracellular fluid volume (ECV), determined by Br82 and total body water (TBW), determined by H3O, were measured and animals sacrificed for removal of adrenals, brains, hearts, kidneys, livers, and right paravertebral muscles. Uremic rats weighed less than control rats (279gm vs 311gm*). ECF and heart size were relatively greater in uremic animals (25.2% vs 22.6%**; 0.0816gm 0.0687gm**+), probably indicating an effect on the cardiovascular system of uremia even when moderate. Absolute intracellular fluid volume (TBW-ECV) (133cc vs 144cc), liver (2.98gm vs 3.60gm*), muscle mass as reflected by 24 hr urine creatinine (8.26mgm vs 9.70mgm *), and total body solids (82.5gm vs 104.1gm**) were reduced in uremic rats either more than, or in proportion to, reduction in body weight. Absolute brain size was equal. *P<.05 **P<.01 +dry organ weights reported