Showing papers on "Body water published in 2018"

Maternal Nutrition and Body Composition During Breastfeeding: Association with Human Milk Composition.

Abstract: The composition of human milk is dynamic and can vary according to many maternal factors, such as diet and nutritional status. This study investigated the association of maternal nutrition and body composition with human milk composition. All measurements and analyses were done at three time points: during the first (n = 40), third (n = 22), and sixth (n = 15) month of lactation. Human milk was analyzed using the Miris human milk analyzer (HMA), body composition was measured with bioelectrical bioimpedance (BIA) using a Maltron BioScan 920-II, and the assessment of women's nutrition was based on a three-day dietary record. The correlation coefficient (Pearson's r) did not show a significant statistical relationship between human milk composition and nutrients in women's diet at three time points. For women in the third month postpartum, we observed moderate to strong significant correlations (r ranged from 0.47 to 0.64) between total protein content in milk and the majority of body composition measures as follows: positive correlations: % fat mass (r = 0.60; p = 0.003), fat-free mass expressed in kg (r = 0.63; p = 0.001), and muscle mass (r = 0.47; p = 0.027); and negative correlation: % total body water (r = -0.60; p = 0.003). The variance in milk fat content was related to the body mass index (BMI), with a significant positive correlation in the first month postpartum (r = 0.33; p = 0.048). These findings suggest that it is not diet, but rather the maternal body composition that may be associated with the nutritional value of human milk.

Fluid balance concepts in medicine: Principles and practice

Abstract: The regulation of body fluid balance is a key concern in health and disease and comprises three concepts. The first concept pertains to the relationship between total body water (TBW) and total effective solute and is expressed in terms of the tonicity of the body fluids. Disturbances in tonicity are the main factor responsible for changes in cell volume, which can critically affect brain cell function and survival. Solutes distributed almost exclusively in the extracellular compartment (mainly sodium salts) and in the intracellular compartment (mainly potassium salts) contribute to tonicity, while solutes distributed in TBW have no effect on tonicity. The second body fluid balance concept relates to the regulation and measurement of abnormalities of sodium salt balance and extracellular volume. Estimation of extracellular volume is more complex and error prone than measurement of TBW. A key function of extracellular volume, which is defined as the effective arterial blood volume (EABV), is to ensure adequate perfusion of cells and organs. Other factors, including cardiac output, total and regional capacity of both arteries and veins, Starling forces in the capillaries, and gravity also affect the EABV. Collectively, these factors interact closely with extracellular volume and some of them undergo substantial changes in certain acute and chronic severe illnesses. Their changes result not only in extracellular volume expansion, but in the need for a larger extracellular volume compared with that of healthy individuals. Assessing extracellular volume in severe illness is challenging because the estimates of this volume by commonly used methods are prone to large errors in many illnesses. In addition, the optimal extracellular volume may vary from illness to illness, is only partially based on volume measurements by traditional methods, and has not been determined for each illness. Further research is needed to determine optimal extracellular volume levels in several illnesses. For these reasons, extracellular volume in severe illness merits a separate third concept of body fluid balance.

Psychophysiological, Body Composition, Biomechanical and Autonomic Modulation Analysis Procedures in an Ultraendurance Mountain Race

Abstract: The current research aimed to analyze psychophysiological, body composition, biomechanical and autonomic modifications in an ultraendurance mountain race. We analyzed 11 finisher voluntary athletes that participated in a 51.2?km ultraendurance mountain race. We measured before and after the mountain ultraendurance event the following parameters: Rate of perceived exertion, body composition, cortical arousal, blood pressure, body temperature, forced vital capacity, blood oxygen saturation, isometric hand strength and heart rate variability parameters. The results of temperature, rate of perceived exertion, heart rate and the percentage of body water at the end of the race increased significantly. However, the variables of body weight, body fat, muscle, body mass index, abdominal fat, blood oxygen saturation, systolic and diastolic blood pressure, cortical arousal and hands and legs strength significantly decreased after the race. The square root of the average of the sum of the differences squared between normal adjacent R-R intervals, percentage of differences between normal adjacent R-R intervals, high-frequency, sensitivity of the short-term variability, and long-term variability decreased significantly after the race. By contrary low-frequency increased significantly at the end of the race. An ultraendurance mountain event produced a large anticipatory anxiety response, an increase in sympathetic modulation, body fat consumption, percentage of body water, and RPE, not affecting the cortical arousal.

Clinical usefulness of bioimpedance analysis for assessing volume status in patients receiving maintenance dialysis.

Abstract: Chronic volume overload is associated with left ventricular hypertrophy and high cardiovascular mortality in patients undergoing dialysis. Therefore, estimating body fluid status is important in these patients. However, most dry-weight assessments are still performed clinically, while attempts have been made to measure the volume status and dry weight of patients undergoing dialysis using bioimpedance analysis (BIA). BIA uses the electrical properties of the human body to alternate current flow and measures resistance values to estimate body water content and composition. BIA is divided into single-frequency BIA, multi-frequency BIA, and bioimpedance spectroscopy (BIS) according to the number of frequencies used, and into whole-body and segmental BIA according to whether or not the whole body is divided into segments. Extracellular water (ECW), intracellular water, and total body water (TBW) contents can be measured with BIA. Dry weight can be estimated by measuring the volume overload of the patient through the ECW/TBW and ECW-to-body weight ratios. Other estimation methods include the normovolemia/hypervolemia slope method, a resistance-reactance (RXc) graph, overhydration measurements using a body composition monitor, and calf BIS. In this review, we will examine the principles of BIA, introduce various volume status measurement methods, and identify the optimal method for patients undergoing dialysis.

High-Salt Diet Causes Expansion of the Lymphatic Network and Increased Lymph Flow in Skin and Muscle of Rats.

Abstract: Objective- A commonly accepted pivotal mechanism in fluid volume and blood pressure regulation is the parallel relationship between body Na+ and extracellular fluid content. Several recent studies have, however, shown that a considerable amount of Na+ can be retained in skin without commensurate water retention. Here, we asked whether a salt accumulation shown to result in VEGF (vascular endothelial growth factor)-C secretion and lymphangiogenesis had any influence on lymphatic function. Approach and Results- By optical imaging of macromolecular tracer washout in skin, we found that salt accumulation resulted in an increase in lymph flow of 26% that was noticeable only after including an overnight recording period. Surprisingly, lymph flow in skeletal muscle recorded with a new positron emission tomography/computed tomography method was also increased after salt exposure. The transcapillary filtration was unaffected by the high-salt diet and deoxycorticosterone-salt treatment, suggesting that the capillary barrier was not influenced by the salt accumulation. A significant reduction in lymph flow after depletion of macrophages/monocytes by clodronate suggests these cells are involved in the observed lymph flow response, together with collecting vessels shown here to enhance their contraction frequency as a response to extracellular Na+. Conclusions- The observed changes in lymph flow suggest that the lymphatics may influence long-term regulation of tissue fluid balance during salt accumulation by contributing to fluid homeostasis in skin and muscle. Our studies identify lymph clearance as a potential disease-modifying factor that might be targeted in conditions characterized by salt accumulation like chronic kidney disease and salt-sensitive hypertension.

Improvement of cellular health indicators and muscle quality in older women with different resistance training volumes.

Abstract: The main purpose of this study was to compare the effects of resistance training (RT) performed with different training volumes on phase angle (PhA), body water components, and muscle quality (MQ) in untrained older adult women. A second purpose was to assess the relationship between PhA and MQ. Sixty-two older adult women (68.6 ± 5.0 years, 65.2 ± 13.3 kg, 156.1 ± 6.2 cm) were randomly assigned into one of the three groups: two training groups performed either 1 set (G1S) or 3 sets (G3S), or a control group (CG). Body water components and PhA were estimated by bioelectrical impedance (BIA). MQ was determined by dividing skeletal muscle mass estimated by dual-energy absorptiometry (DXA) by total muscle strength from three exercises. After the intervention period, both training groups demonstrated improvements (P < 0.05) when compared with CON for intracellular water, total body water, PhA, and MQ. These results suggest that RT can improve PhA, body water components, and MQ after 12 weeks of RT in ...

Asymptomatic fluid overload predicts survival and cardiovascular event in incident Chinese peritoneal dialysis patients.

Abstract: Background Fluid overload is common among asymptomatic peritoneal dialysis (PD) patients. We aim to determine the prevalence and prognostic significance of fluid overload, as measured by bioimpedance spectroscopy, in asymptomatic incident PD patients. Methods We performed a single-center study on 311 incident PD patients. Volume status was represented by the volume of overhydration (OH), OH/extracellular water (ECW) ratio, ECW/total body water (TBW) ratio, and ECW to intracellular water (ICW) ratio (E:I ratio). Patient survival, technique survival and cardiovascular event-free survival were determined. Results The median period of follow up was 27.3 months. Fluid overload was present in 272 patients (87.5%) when defined as OH volume over 1.1L. All hydration parameters significantly correlated with Charlson Comorbidity Index, and inversely with total Kt/V, and serum albumin. Multivariate cause-specific Cox analysis showed that volume status independently predicted patient survival; every 0.1 unit increase in E:I ratio was associated with 24.5% increase in all-cause mortality (adjusted cause-specific hazard ratio [ACSHR] 1.245, p = 0.002). Hydration status was also an independent predictor of cardiovascular event-free survival after excluding hospital admission for congestive heart failure; each 0.1 unit increase in E:I ratio was associated with 18.7% decrease in cardiovascular event-free survival (ACSHR 1.187, p = 0.011). In contrast, hydration parameters were not associated with technique survival. Conclusions Fluid overload is common in asymptomatic incident PD patients and is a strong predictor of patient survival and cardiovascular event. The impact of bioimpedance spectroscopy-guided fluid management on the outcome of PD patients deserves further study.

Dry weight targeting: The art and science of conventional hemodialysis.

Abstract: Fluid volume overload is common and is associated with adverse outcomes in hemodialysis patients. Practicing physicians individually manage fluid volume balance in their dialysis patients according to blood pressure, interdialytic weight gain, cardiac function, nutritional status, and other comorbidities. However, accurate assessment of fluid volume status remains a concern. Indicators of dry weight target have been explored further with newer concepts and technologies. In general, total body water comprises approximately 50%-60% of adult body weight (range, 45%-75%), and water comprises 73.3% of lean body mass. The standard hydration status between intracellular water and extracellular water is maintained at a ratio of 62:38 in healthy adults, which, however, is influenced universally by body cell volume driven by age and muscle mass. Fluid volume imbalance in dialysis patients also is characterized primarily by decreased body cell mass associated with aging and muscle attenuation, as well as excess extracellular water content associated with sodium retention, which may be associated with the reserve capacity for volume overload. Indeed, dialysis patients with a leaner body mass have a higher prevalence of hypertension, poorer hypertension control, and greater left ventricular hypertrophy. Understanding of these body composition changes by aging and sarcopenia can aid clinical decision making in the dry weight assessments in dialysis patients. Advising patients with consistently high interdialytic weight gain to practice salt restriction and providing appropriate nutritional support for malnourished patients with downward trajectory in their dry weight would be of great help to achieve optimal fluid volume status.

Validating the use of bioimpedance spectroscopy for assessment of fluid status in children.

Abstract: Bioimpedance spectroscopy (BIS) with a whole-body model to distinguish excess fluid from major body tissue hydration can provide objective assessment of fluid status. BIS is integrated into the Body Composition Monitor (BCM) and is validated in adults, but not children. This study aimed to (1) assess agreement between BCM-measured total body water (TBW) and a gold standard technique in healthy children, (2) compare TBW_BCM with TBW from Urea Kinetic Modelling (UKM) in haemodialysis children and (3) investigate systematic deviation from zero in measured excess fluid in healthy children across paediatric age range. TBW_BCM and excess fluid was determined from standard wrist-to-ankle BCM measurement. TBW_D2O was determined from deuterium concentration decline in serial urine samples over 5 days in healthy children. UKM was used to measure body water in children receiving haemodialysis. Agreement between methods was analysed using paired t test and Bland-Altman method comparison. In 61 healthy children (6–14 years, 32 male), mean TBW_BCM and TBW_D2O were 21.1 ± 5.6 and 20.5 ± 5.8 L respectively. There was good agreement between TBW_BCM and TBW_D2O (R2 = 0.97). In six haemodialysis children (4–13 years, 4 male), 45 concomitant measurements over 8 months showed good TBW_BCM and TBW_UKM agreement (mean difference − 0.4 L, 2SD = ± 3.0 L). In 634 healthy children (2–17 years, 300 male), BCM-measured overhydration was − 0.1 ± 0.7 L (10–90th percentile − 0.8 to + 0.6 L). There was no correlation between age and OH (p = 0.28). These results suggest BCM can be used in children as young as 2 years to measure normally hydrated weight and assess fluid status.

Ad libitum drinking adequately supports hydration during 2 h of running in different ambient temperatures

Abstract: To examine if ad libitum drinking will adequately support hydration during exertional heat stress. Ten endurance-trained runners ran for 2 h at 60% of maximum oxygen uptake under different conditions. Participants drank water ad libitum during separate trials at mean ambient temperatures of 22 °C, 30 °C and 35 °C. Participants also completed three trials at a mean ambient temperature of 35 °C while drinking water ad libitum in all trials, and with consumption of programmed glucose or whey protein hydrolysate solutions to maintain euhydration in two of these trials. Heart rate, oxygen uptake, rectal temperature, perceived effort, and thermal sensation were monitored, and nude body mass, hemoglobin, hematocrit, and plasma osmolality were measured before and after exercise. Water and mass balance equations were used to calculate hydration-related variables. Participants adjusted their ad libitum water intake so that the same decrease in body mass (1.1–1.2 kg) and same decrease in body water (0.8–0.9 kg) were observed across the range of ambient temperatures which yielded significant differences (p < .001) in sweat loss. Overall, water intake and total water gain replaced 57% and 66% of the water loss, respectively. The loss in body mass and body water associated with ad libitum drinking resulted in no alteration in physiological and psychophysiological variables compared with the condition when hydration was nearly fully maintained (0.3 L body water deficit) relative to pre-exercise status from programmed drinking. Ad libitum drinking is an appropriate strategy for supporting hydration during running for 2 h duration under hot conditions.

Body composition and fatty tissue distribution in women with various menstrual status

Abstract: Background Menopause, also referred to as climacterium, is a period of multiple changes in the structure and functions of a woman organism. Objective Determination of differences in body composition and fatty tissue distribution in women from groups discriminated based on their menstrual status. Material and methods The survey covered 312 women aged 38-75 years. Menstrual status of the surveyed women was established according to WHO guidelines based on answers to a questionnaire, and three groups were discriminated: women in the premenopausal period (group 1), in the perimenopausal period (group 2), and in the postmenopausal period (group 3). The following anthropomological measurements were taken: body height, body mass, waist and hip circumference, and thickness of 6 skinfolds. Their results enabled evaluating the somatic built of women in the separated groups. Fatty tissue distribution was determined based on TER distribution index calculated as a ratio of the sum of trunk skinfolds (TSS) to the sum of extremity skinfolds (ESS). Body composition of the women, including percentage of body fat, lean body mass, soft tissue mass, and total body water, was assessed using an IOI 353 analyzer by JAWON MEDICAL. In addition, percentages of women with underweight, normal content of fatty tissue, and these with overweight and obesity were calculated. The WHR index was computed in the case of obese women. Results The highest values of body mass, hip circumference and most of the skinfolds were determined in the perimenopausal group, whereas the postmenopausal women were characterized by the highest percentage of body fat (PBF) and by the lowest contents of lean tissue, soft tissue, and total water content in the body. The highest percentage of obese women was found in the postmenopausal group, including 40% of them having visceral type obesity. The occurrence of the menopause contributed to changes in fatty tissue distribution, causing its shift from extremities toward the trunk. Conclusions The study showed differences in the somatic built and body composition in groups of women distinguished based on their menstrual status.

A novel method of utilizing skinfolds and bioimpedance for determining body fat percentage via a field-based three-compartment model.

Abstract: The purpose was to determine if skinfolds (SF) and bioelectrical impedance analysis (BIA) could provide accurate estimates of body volume (BV) and total body water (TBW), respectively, for use in a 3-compartment (3-C) model to estimate percent body fat (BF%) when compared to laboratory derived measures. A sample of sixty-four men (age = 22.9 ± 5.4 years) and 59 women (age = 21.6 ± 4.3 years) participated in the study. Laboratory 3-C (3CLAB) model BF% was determined with underwater weighing for body volume (BV) and bioimpedance spectroscopy for total body water (TBW). The 3-C field (3CFIELD) estimates of BF% included BV from the 7-site SF technique and TBW from hand-to-foot BIA. A significant difference in BF% (p < 0.01) was found between the 3CLAB and 3CFIELD in the entire sample and within the men, but the effect sizes (ES) were small (0.09 and 0.17, respectively). The difference between means was not significant in the women (ES = 0.05, p = 0.332). Compared to the 3CLAB, the total error (TE) ranged 2.2–2.4% for 3CFIELD, 5.7–5.8% for SF, and 4.0–4.6% for BIA. The findings suggest that BV and TBW derived from SF and BIA, respectively, can be used in a 3CFIELD model to increase the accuracy of BF% estimates over SF and BIA alone.

Pre- and Postoperative Body Composition and Metabolic Characteristics in Patients with Acromegaly: A Prospective Study.

Abstract: Objective. To investigate the preoperative body composition, metabolic characteristics, and postoperative changes in patients with active acromegaly and analyze the effects of gender and age. Methods. We included 36 patients with untreated acromegaly and 37 patients with nonfunctional pituitary adenomas. Adipose tissue (AT), the visceral fat index (VFI), sclerotin, protein, skeletal muscle, total body water (TBW), intracellular water (ICW), and extracellular water (ECW) were measured using bioelectrical impedance analysis (BIA). Total energy expenditure (TEE) and basal metabolism (BM) were measured with a cardiopulmonary and metabolic analyzer (CMA). Tricep skinfold thickness (TST), bicep circumference, waistline, hipline, and calf circumference were measured with a skinfold caliper and tape. These indices were measured before surgery and 3 months and 1 year after surgery. Results. Overall, AT, VFI, and TST were lower, whereas sclerotin, protein, skeletal muscle, TBW, ICW, ECW, TEE, and BM were higher in acromegaly patients. Postoperatively, TST rose initially and then decreased, the waistline increased, and sclerotin, skeletal muscle, TEE, and BM decreased. Changes in these indices differed with gender and age in unique patterns. Conclusions. Body composition and metabolism in acromegaly patients changed after surgery, and gender and age influenced these changes.

Effects of procedure, upright equilibrium time, sex and BMI on the precision of body fluid measurements using bioelectrical impedance analysis

Abstract: Extensive work has addressed the validity of bioimpedance (BIA) measurements and the effect of posture on fluid homeostasis. However, limited research has investigated effects of subject preparation. This study aimed to determine the precision of total body water (TBW) and extracellular water (ECW) measurements using a stand-on multifrequency BIA (MFBIA seca mBCA 514/515), in three pre-test procedures: supine, sitting, and following walking, with specific reference to the influence of sex and body mass index (BMI). Fifty three healthy, ambulatory men (n=26, age:32.5±9.4 years) and women (n=27, age:35.2±10.3 years) received repeat MFBIA measurements (six measurements from 0 to 15 min). Agreement and precision were evaluated for each condition and paired time points. Significant TBW sex differences from supine posture were observed for walking (females) and sitting (males) postures. For BMI (⩽24.9 kg m−2) significant TBW differences from supine were observed for both sitting and walking and significant ECW differences from sitting were also observed with both supine and walking. There was no significant effect of sex or BMI (⩾25.0 kg m−2) on ECW measures. Irrespective of sex or BMI, there was close agreement in TBW and ECW precision over the three protocols. Practitioners can have confidence in the precision of TBW and ECW measurements within a 15 min time period and pre-testing conditions (supine, sitting or walking) in healthy subjects, though must be cautious in assessments when pre-test postures change. Further research to examine the impact of pre-testing procedures on stand-on MFBIA BIA measurements, including subjects with fluid disturbance, is warranted.

The availability of water associated with glycogen during dehydration; a reservoir or raindrop?

Abstract: This study evaluated whether glycogen-associated water is a protected entity not subject to normal osmotic homeostasis. An investigation into practical and theoretical aspects of the functionality of this water as a determinant of osmolality, dehydration, and glycogen concentration was undertaken. In vitro experiments were conducted to determine the intrinsic osmolality of glycogen–potassium phosphate mixtures as would be found intra-cellularly at glycogen concentrations of 2% for muscle and 5 and 10% for liver. Protected water would not be available to ionic and osmotic considerations, whereas free water would obey normal osmotic constraints. In addition, the impact of 2 L of sweat loss in situations of muscle glycogen repletion and depletion was computed to establish whether water associated with glycogen is of practical benefit (e.g., to increase “available total body water”). The osmolality of glycogen–potassium phosphate mixtures is predictable at 2% glycogen concentration (predicted 267, measured 265.0 ± 4.7 mOsmol kg−1) indicating that glycogen-associated water is completely available to all ions and is likely part of the greater osmotic system of the body. At higher glycogen concentrations (5 and 10%), there was a small amount of glycogen water (~ 10–20%) that could be considered protected. However, the majority of the glycogen-associated water behaved to normal osmotic considerations. The theoretical exercise of selective dehydration (2 L) indicated a marginal advantage to components of total body water such as plasma volume (1.57% or 55 mL) when starting exercise glycogen replete. Glycogen-associated water does not appear to be a separate reservoir and is not able to uniquely replete water loss during dehydration.

Dietary cation and anion difference: Effects on milk production and body fluid distribution in lactating dairy goats under tropical conditions.

Abstract: This study aimed to determine the effect of dietary cation and anion difference (DCAD) on milk production and body fluid distribution in lactating dairy goats. Ten dairy goats were selected and divided into two groups, five animals each. Animals received either control DCAD (control, 22.81 mEq/100 g dry matter (DM)) or high DCAD (DCAD, 39.08 mEq/100 g DM). The results indicated that rectal temperature (Tr), respiration rate, milk yield and compositions did not differ between groups. But the percentage change of Tr from the DCAD group was lower than the control group between 09.00 and 13.00 hours. DM intake tended to increase in the DCAD group. Dairy goats in the DCAD group drank more water, but urinary excretion and plasma antidiuretic hormone concentration remained unchanged. Apparent water balance was higher from the DCAD group over 24 h. There was no effect of DCAD on plasma and blood volumes, but tended to increase in extracellular fluid and thereby increased total body water. The present results indicate that animals supplemented with high DCAD increase their total body water and apparent water balance. These results have contributed to the process of adaptation for evaporative cooling and would be useful in slowing down the elevation in Tr.

The Influence of Body Mass Composition on the Postural Characterization of School-Age Children and Adolescents.

Abstract: Introduction. In recent years a significant increase in the percentage of children with postural problems has been observed. It is necessary to focus on preventing the phenomenon and on analysis of existing postural defects. Aim. The aim of this work was to assess the potential relationship between body mass composition and body posture in school-age children. Material and Methods. 464 school-age children ranging from 6 to 16 years (234 boys and 230 girls) were qualified for the study. Body mass composition was assessed using the analyzer Tanita MC 780 MA. Assessment of body posture was performed using Zebris system. All the results were analyzed with statistical methods. The accepted level of significance was p<0.05. Results. Analyses of the disparities between the girls and the boys showed statistically significant differences in all of the body mass components and in obliquity of the pelvis/shoulder. The boys were characterized by higher contents of muscle tissue (p<0.001), bone tissue (p<0.001), fatless tissue (p<0.001), and body water (p<0.001) as well as a greater obliquity angle (p=0.018). The girls, on the other hand, were found with higher content of fatty tissue (p<0.001). The children with lower content of muscle tissue (p=0.030), fatless tissue (p=0.030), water (p=0.030), and higher content of fatty tissue measured in kg (p=0.027) were characterized by greater pelvic obliquity. Conclusion. The current study shows evidence that sex, as a strongly differentiating factor, determines body mass composition and the occurrence of suboptimal postures only in the pelvic area. Body mass composition differentiates body posture of the study group. The content of fatty tissue influences the occurrence of suboptimal postures in the scapula and pelvic area in the frontal plane. The content of muscle tissue is associated with faulty postures in the scapula and pelvic area in the frontal plane.

VolumE maNagement Under body composition monitoring in critically ill patientS on CRRT: study protocol for a randomized controlled trial (VENUS trial).

Abstract: Despite recent technical advances in the management of acute kidney injury (AKI), such as continuous renal replacement therapy (CRRT), intensive care unit mortality is still high, at approximately 40 to 50%. Although several factors have been reported to predict mortality in AKI patients, fluid overload (FO) during CRRT is a well-known predictor of patient survival. However, FO has been mostly quantified as an arithmetical calculation and determined on the basis of the physicians’ perception. Even though such quantification and assessment provides an easy evaluation of a patient’s fluid status and is a simple method, it is not applicable unless a detailed record of fluid monitoring is available. Furthermore, the method cannot differentiate excess water in individual water compartments but can only reflect excess total body water. Bioimpedance analysis (BIA) has been used to measure the nutritional component of body composition and is a promising tool for the measurement of volume status. However, there has been no prospective interventional study for fluid balance among CRRT-treated AKI patients using BIA. Therefore, we will investigate the usefulness of fluid management using the InBody S10 (InBody®, Seoul, Korea), a BIA tool, compared with that of generally used quantification methods. This will be a multicenter, prospective, randomized controlled trial. A total of 244 patients undergoing CRRT treatment will be enrolled and randomly assigned to receive either to InBody S10-guided management or to fluid management based only on clinical information for 7 days. The primary outcome is to compare the rate of euvolemic status 7 days after the initiation of CRRT, with a secondary outcome being to compare the 28-, 60-, and 90-day mortality rates between the two groups. This will be the first clinical trial to investigate the effect of using BIA-guided fluid management to achieve euvolemia in CRRT-treated AKI patients. ClinicalTrials.gov, ID: NCT03330626 . Registered on 6 November 2017.

Efficacy of Glucose or Amino Acid-Based Commercial Beverages in Meeting Oral Rehydration Therapy Goals After Acute Hypertonic and Isotonic Dehydration

Abstract: BACKGROUND The efficacy of different commercial beverage compositions for meeting oral rehydration therapy (ORT) goals in the treatment of acute dehydration in healthy humans has not been systematically tested The objective of the study was to compare fluid retention, plasma volume (PV), and interstitial fluid (ISF) volume restoration when using 1 popular glucose-based and 1 novel amino acid-based (AA) commercial ORT beverage following experimental hypertonic or isotonic dehydration METHODS Twenty-six healthy adults (21 males, 5 females) underwent either a controlled bout of hypertonic (n = 13) or isotonic (n = 13) dehydration (3%-4% body mass) via eccrine or renal body water and electrolyte losses induced using exercise-heat stress (EHS) or Lasix administration (LAS), respectively Rehydration was achieved over 90 minutes by matching fluid intake to water losses (1:1) using a sports drink (SP) or AA commercial ORT beverage Fluid retention (water and electrolytes), PV, and ISF volume changes were tracked for 180 minutes RESULTS AA produced significantly (P <005) greater fluid retention (75% vs 57%), ISF volume restoration, and tended (P = 006) to produce greater PV restoration in trial EHS In trial LAS, neither beverage exceeded 65% retention, but AA replaced electrolytes and preserved ISF volume better than SP (P <005) CONCLUSION The results of this study demonstrate superior rehydration when using AA compared with SP for both hypertonic and isotonic dehydration

Principles of quantitative water and electrolyte replacement of losses from osmotic diuresis

Abstract: Osmotic diuresis results from urine loss of large amounts of solutes distributed either in total body water or in the extracellular compartment. Replacement solutions should reflect the volume and monovalent cation (sodium and potassium) content of the fluid lost. Whereas the volume of the solutions used to replace losses that occurred prior to the diagnosis of osmotic diuresis is guided by the clinical picture, the composition of these solutions is predicated on serum sodium concentration and urinary sodium and potassium concentrations at presentation. Water loss is relatively greater than the loss of sodium plus potassium leading to hypernatremia which is seen routinely when the solute responsible for osmotic diuresis (e.g., urea) is distributed in body water. Solutes distributed in the extracellular compartment (e.g., glucose or mannitol) cause, in addition to osmotic diuresis, fluid transfer from the intracellular into the extracellular compartment with concomitant dilution of serum sodium. Serum sodium concentration corrected to euglycemia should be substituted for actual serum sodium concentration when calculating the composition of the replacement solutions in hyperglycemic patients. While the patient is monitored during treatment, the calculation of the volume and composition of the replacement solutions for losses of water, sodium and potassium from ongoing osmotic diuresis should be based directly on measurements of urine volume and urine sodium and potassium concentrations and not by means of any predictive formulas. Monitoring of clinical status, serum sodium, potassium, glucose, other relevant laboratory values, urine volume, and urine sodium and potassium concentrations during treatment of severe osmotic diuresis is of critical importance.

The role of bioelectrical impedance analysis, NT-ProBNP and inferior vena cava sonography in the assessment of body fluid volume in children with nephrotic syndrome

Abstract: Background Assessment of volume status and differentiating “underfill” and “overfill” edema is essential in the management of patients with nephrotic syndrome (NS). Objectives Our aim was to evaluate the volume status of NS patients by using different methods and to investigate the utility of bioelectrical impedance analysis (BIA) in children with NS. Methods The hydration status of 19 patients with NS (before treatment of NS and at remission) and 25 healthy controls was assessed by multifrequency BIA, serum N-terminal-pro-brain natriuretic peptide (NT-proBNP) levels, inferior vena cava (IVC) diameter, left atrium diameter (LAD) and vasoactive hormones. Results Renin, aldosterone levels, IVC diameter and LAD were not statistically different between the groups. NT-proBNP values were statistically higher in the attack period compared to remission and the control group (p = 0.005 for each). Total body water (TBW), overhydration (OH) and extracellular water (ECW) estimated by the BIA measurement in the attack group was significantly higher than that of the remission group and controls. There were no significant correlations among volume indicators in group I and group II. However, significant correlations were observed between NT-proBNP and TBW/BSA (p = 0.008), ECW/BSA (p = 0.003) and ECW/ICW (p = 0.023) in the healthy group. TBW was found to be higher in patients with NS in association with increased ECW but without any change in ICW. NT-proBNP values were higher in patients during acute attack than during remission. Conclusions Our findings support the lack of hypovolaemia in NS during acute attack. In addition, BIA is an easy-to-perform method for use in routine clinical practice to determine hydration status in patients with NS.

Nutritional Status of Men with Ulcerative Colitis in Remission in a Pair–Matched Case–Control Study

Abstract: The aim of the presented research was to analyze the nutritional status of male subjects with ulcerative colitis in remission by using body composition that was assessed by bioelectrical impedance measurement against a gender-matched control group. Forty-four male patients in remission with ulcerative colitis were recruited for the case-control study and simultaneously, a matched control group of 44 male individuals without inflammatory bowel diseases was pair-matched (general community individuals). The body composition measurement was conducted by the bioelectrical impedance method using BodyComp MF Plus and Bodygram Pro 3.0 software. Parameters assessed include body cell mass (BCM), total body water (TBW), extracellular body water (EBW), intracellular body water (IBW), fat mass (FM), fat-free mass (FFM), muscle mass (MM), and the body cell mass (BCM) index. A significant between-group difference was observed only for EBW, where subjects with ulcerative colitis were characterized by a higher mass of extracellular water (p = 0.0405). Individuals with ulcerative colitis were characterized by a lower BCM share than the control group (p = 0.0192). A comparative analysis of the body composition of male patients with ulcerative colitis with those who did not have ulcerative colitis revealed only minor differences. The risk of malnutrition, assessed using both BMI and bioelectrical impedance, in men with ulcerative colitis in remission is the same as in healthy males in the matched general population.

Estimation of Body Composition and Water Data Depends on the Bioelectrical Impedance Device.

Abstract: Overweight, obese and chronic kidney disease patients have an altered and negative body composition being its assessment important. Bioelectrical impedance analysis is an easy-to-operate and low-cost method for this purpose. This study aimed to compare and correlate data from single- and multi-frequency bioelectrical impedance spectroscopy applied in subjects with different body sizes, adiposity, and hydration status. It was a cross-sectional study with 386 non-chronic kidney disease volunteers (body mass index from 17 to 40 kg/m2), 30 patients in peritoneal dialysis, and 95 in hemodialysis. Bioelectrical impedance, body composition, and body water data were assessed with single- and multi-frequency bioelectrical impedance spectroscopy. Differences (95% confidence interval) and agreements (Bland-Atman analyze) between devices were evaluated. The intraclass correlation coefficient was used to measure the strength of agreement and Pearson's correlation to measure the association. Regression analyze was performed to test the association between device difference with body mass index and overhydration. The limits of agreement between devices were very large. Fat mass showed the greatest difference and the lowest intraclass and Pearson's correlation coefficients. Pearson's correlation varied from moderate to strong and the intraclass correlation coefficient from weak to substantial. The difference between devices were greater as body mass index increased and was worse in the extremes of water imbalance. In conclusion, data obtained with single- and multi-frequency bioelectrical impedance spectroscopy were highly correlated with poor agreement; the devices cannot be used interchangeably and the agreement between the devices was worse as body mass index and fat mass increased and in the extremes of overhydration.

The development of a whole-body potassium counter for the measurement of body cell mass in adult humans.

Abstract: BACKGROUND AND OBJECTIVES: Total body potassium (TBK), has a natural radioactive isotope, which can be measured to derive body cell mass (BCM), making it useful in clinical conditions, early growth and pregnancy. The objective was to build a whole-body potassium counter (WBKC), to accurately measure TBK in the body. METHODS AND STUDY DESIGN: A WBKC was designed and constructed using a shadow shield. A cellular four compartment (4C) model of fat free mass (FFM), using estimates of TBK along with total body water (TBW), was compared with a molecular 4C model of the body in twenty healthy adults (10 men and 10 women). The molecular 4C model used measurements of TBW, bone mineral content (BMC), and body volume from deuterium dilution (DD), dual energy x-ray absorptiometry (DXA) and air displacement plethysmography (ADP) respectively. RESULTS: The accuracy and precision of the WBKC were 2.8% and 1.9% with TBK phantoms. The mean estimate of FFM by the molecular 4C model was 40.4±6.8 kg, while it was 41.2±7.3 kg using the cellular 4C model. CONCLUSIONS: A WBKC constructed from base principles, was relatively low cost, efficient, safe and noninvasive, but requires some design considerations. Its measurement of FFM compared well with the molecular 4C model. Once constructed, it offers a relatively costless, accurate and repeatable method to measure body composition in conditions with uncertain hydration status, at all life stages.

Low salt and low calorie diet does not reduce more body fat than same calorie diet: a randomized controlled study.

Abstract: // Hye Jin Kang 1 , Dae Won Jun 1 * , Seung Min Lee 2 * , Eun Chul Jang 3 and Yong Kyun Cho 4 1 Department of Internal Medicine, Hanyang University College of Medicine, Seoul, South Korea 2 Department of Food and Nutrition, Sungshin Women's University, Seoul, South Korea 3 Department of Occupational and Environmental Medicine, Soonchunhyang University College of Medicine, Cheonan, South Korea 4 Department of Internal Medicine, Kangbuk Samsung Hospital, Sungkyunkwan University School of Medicine, Seoul, South Korea * These authors contributed equally to this work Correspondence to: Dae Won Jun, email: noshin@hanyang.ac.kr Seung Min Lee, email: smlee@sungshin.ac.kr Keywords: low salt; obesity; diet Received: July 28, 2017 Accepted: November 16, 2017 Published: January 04, 2018 ABSTRACT Background: Recent several observational studies have reported that high salt intake is associated with obesity. But it is unclear whether salt intake itself induce obesity or low salt diet can reduce body fat mass. We investigated whether a low salt diet can reduce body weight and fat amount. Matrials and Methods: The randomized, open-label pilot trial was conducted at a single institution. A total of 85 obese people were enrolled. All participants were served meals three times a day, and provided either a low salt diet or control diet with same calorie. Visceral fat was measured with abdominal computer tomography, while body fat mass and total body water was measured with bio-impedance. Results: Reductions in body weight (–6.3% vs. –5.0%, p = 0.05) and BMI (–6.6% vs. –5.1%, p = 0.03) were greater in the low salt group than in the control group. Extracellular water and total body water were significantly reduced in the low salt group compared to the control group. However, changes in body fat mass, visceral fat area, and skeletal muscle mass did not differ between the two groups. Changes in lipid profile, fasting glucose, and HOMA-IR did not differ between the two groups. Conclusions: A two-month low salt diet was accompanied by reduction of body mass index. However, the observed decrease of body weight was caused by reduction of total body water, not by reduction of body fat mass or visceral fat mass.

Update: Efficacy of Military Fluid Intake Guidance.

Abstract: Background Fluid intake during military training is prescribed based on the interactions among work rates, environmental conditions, and uniform configurations. The efficacy of this guidance has not been empirically assessed in over a decade. To determine the acceptability of the fluid intake guidance, sweat losses were measured in a variety of conditions with modern uniform/body armor configurations and were then compared to prescribed fluid intakes for each condition (workload, environment, clothing). Methods Whole body sweat losses of 324 Soldiers and 14 model simulations were measured under a variety of work intensities ((Watts) easy, moderate, hard), work durations (2-25 h), environmental conditions (White-Black flag), and uniform configurations (including Army Combat Uniform and body armor). Whole body sweat losses were then calculated relative to 4 h drinking guidance and in accordance with TB MED 507 recommended work/rest ratios. The differences between the prescribed fluid intake and sweat loss were calculated and expressed as a percent loss or gain of body weight. Values within a threshold of ±2% body water flux (BWF) were deemed an acceptable conservative starting point for performance and health concerns. Findings Values within ±2% BWF numbered 309/338; 25 of 338 observations exceeded the +2% BWF while 4 of 338 observations exceeded the -2% BWF. When total fluid restriction was simulated, all experienced body weight loss with 151 of 338 observations exceeding the -2% BWF. Discussion When calculated using actual measured sweating rates from the laboratory and model simulations, current fluid intake guidance appears to predict with 91.4% accuracy the volume of fluid required to maintain a proper euhydrated state (±2%) during 4 h of exercise. Simulations of total fluid restriction support the necessity for fluid intake guidance so that the Warfighter's performance does not degrade. It is recommended that the current military fluid intake guidance focuses on methods for accurately tracking fluid intakes.

Non-imaging Method: Bioelectrical Impedance Analysis

Abstract: Bioelectrical impedance analysis allows measurement of total body water, which is used to estimate fat-free body mass and, by difference with body mass, body fat. An athlete appointment of 15 min is needed for body mass and standing stature measurement, electrode placement, and then 1 min of data collection. The method is popular due to the procedure being simple and non-invasive, good portability of the equipment and its relatively low cost compared to other methods of body composition analysis. However, precision and validity can be low without a standardised protocol of assessment that includes guidance for subject presentation. Sensitivity to monitor change of physique is low given variation in athlete presentation for testing can affect the results (e.g. levels of hydration). Training is available from equipment suppliers; however, there are no accreditation systems. The techniques to collect the data are easy; however, interpretation of the data is impeded given the black box approach to the data. Studies that compare results from bioelectrical impedance analysis to other body composition techniques are outlined, and example reports to athletes are provided.

Increased Urine Production Due to Leg Fluid Displacement Reduces Hours of Undisturbed Sleep

Abstract: Objective To investigate whether or not the leg fluid displacement observed when moving from the standing to recumbent position at bedtime reduces the hours of undisturbed sleep (HUS). Methods Men aged 50 years or older who were hospitalized for urological diseases were investigated. Body water evaluation was performed three times with a bioelectric impedance method: (i) 17:00, (ii) 30 min after (short-term), and (iii) waking up (long-term). A frequency volume chart was used to evaluate the status of nocturnal urine production, and the factors affecting HUS were investigated. Results A total of 50 patients (mean age: 68 years) were enrolled. Short-term changes in extracellular fluid (ECF in the legs showed a significant positive correlation with urine production per unit of time at the first nocturnal voiding (UFN/HUS) (r = 0.45, P = 0.01). In the comparison between patients who had <3 HUS vs. those who had ≥3 HUS, the <3 HUS group showed significantly greater short-term changes in leg fluid volume, night-time water intake (17:00–06:00), and UFN/HUS. Multivariate analysis to assess the risk factors for <3 HUS indicated UFN/HUS as a risk factor in the overall model, and short-term changes in leg ECF and night-time water intake as risk factors in the model that only considered factors before sleep. Conclusions Nocturnal leg fluid displacement may increase urine production leading up to first voiding after going to bed, and consequently, induce early awakening after falling asleep.