Increase In Total Body Water Research Articles

Особенности применения и возможности биоимпедансного анализа в нефрологии

The purpose — to determine the features of the body’s biocomposition using bioimpedance analysis in patients with kidney pathology. Material and methods. 39 patients from the Nephrology Department of Republican Clinical Hospital were examined. Among them were patients with acute tubulointerstitial nephritis, chronic glomerulonephritis, and nephropathy of mixed etiology. All patients underwent bioimpedance analysis of body composition using the MEDASS ABC-02 device. The study presents the results of bioimpedance analysis based on different electrical resistance of biological tissues. Bioimpedance analysis allows studying the body composition of patients with different profiles. The possibilities of bioimpedance analysis in nephrology are determined by the assessment of nutritional and volemic status. Results. Approximately half of the patients (47.8%) had an high body mass index. However, when analyzing indicators of fat mass and total body water, it was found that 36.3% of patients had normal to low levels of fat mass, with the increase in total body water being due to fluid overload. Meanwhile, 27.3% with normal body mass index had an increase in fat mass. The lean body mass, reflecting the body’s protein depot, was below normal in 15.2% of patients, which may be associated with nutritional status impairment and the development of protein-energy malnutrition. Conclusion. The study demonstrated the role of bioimpedance analysis in evaluating the volumetric and nutritional status in patients with a nephrological profile.

Body composition measured by multi-frequency bioelectrical impedance following creatine supplementation.

Acute fluid ingestion increases estimated body fat percentage (BF%) measurements by single frequency (SF-BIA) and multi-frequency bioelectrical impedance (MF-BIA). It is unknown if MF-BIA accurately measures total BF% and total body water (TBW) after creatine supplementation, which causes fluid retention, and resultant increases in fat-free mass and TBW. The purpose of this study was to analyze the effect of creatine supplementation on body composition and TBW measured through a popular MF-BIA device (InBody 770). Thirteen male and 14 female subjects (18-22 years) completed one week of creatine monohydrate (0.3 g/kg body weight) or maltodextrin. Pre- and post-supplementation body composition measurements included dual-energy X-ray absorptiometry (DEXA), SF-BIA measured by an Omron HBF-306C device, and MF-BIA measured by an InBody 770 device to measure BF%, fat free mass (FFM), and fat mass (FM). Additionally, intracellular water (ICW), extracellular water (ECW), and TBW were estimated by MF- BIA. FFM increased more in the creatine group than the placebo group measured by all body composition modes (1.2 kg, 1.9 kg, and 1.1 kg increase for SF-BIA, MF-BIA, and DEXA respectively, P<0.05). Creatine supplementation resulted in a 2% increase (P<0.05) in TBW measured by MF-BIA (40.4±9.5 to 41.2±9.6 kg). One week of creatine supplementation increased TBW as detected by the InBody 770 device. Changes in body composition that occurred due to the increase in TBW were detected as an increase in FFM measured by SF-BIA, MF-BIA, and DEXA.

#5006 RELATIONSHIP BETWEEN EXTRACELLULAR WATER PERCENTAGE AND MORTALITY IN PATIENTS UNDERGOING CHRONIC HEMODIALYSIS

Abstract Background and Aims Chronic hemodialysis (HD) patients have a high cardiovascular and mortality risk. This is secondary to numerous risk factors specific to the HD population. Relevant on cardiovascular disease and mortality in HD, is the sodium intake and the extent of the sodium pool of patients. An increase in the total sodium pool may have a negative action on cardio vascular system directly and mediated by the increase in total body water associated with an increase in the sodium pool. However, the assessment of the sodium pool in patients is clinically complex. Some evidence has suggested that the assessment of the extracellular water percentage (ECW%) in the HD patient may be a marker of the sodium pool. In fact, the increase in extracellular sodium is followed by a shift of water from the intracellular compartment to the extracellular compartment. The assessment of ECW% could therefore identify patients with greater ECW increase secondary to the greater sodium pool and therefore with high clinical risk. Primary aim: to evaluate the relationship between extracellular water percentage and mortality in patients on chronic hemodialysis. Method This is an observational prospective cohort study. The inclusion criteria were chronic HD for at least three months, minimum follow-up of six months, age greater than 18 years. In all of the included patients we performed the bioimpedance examination with a dedicated instrument after hemodialysis session, after the long interdialytic interval, for the evaluation of ECW (L), ECW (%), TBW (L / m), ICW (L). The protocol involved dividing the population into two groups based on normal or pathological ECW%, according to values calculated by gender and age and then evaluating the incidence of death in a 36-month follow-up. Results We enrolled 101 patients with an average age of 71± 14 years in HD for 51 ±15 months. During the average follow-up of 19 months we observed 31 deaths (30% of the population) with an annual mortality of 15%. ECW % correlated positively with age (R: 0.498 P:0.01) and differential post-dialysis pressure (R: 0.260; P:0.01). 41 patients (aged 64 ± 13 years) had a normal ECW % (ECW-N) and 60 patients (75±13 years) had pathological ECW% (ECW-P). ECW-P patients had an increased mortality respect to ECW-N patients (60% vs 20% p: 0.01). The survival curve confirmed higher mortality in the ECW-P group (log-rank test P 0.02). These results were confirmed in a sub-analysis of two age-matched ECW-N (n. 20 age 64±10 years) vs ECW-P (n. 20 age 65±12 years) subgroups (log-rank test P:0.05). Conclusion Our data showed that ECW% identifies HD patients at increased mortality risk in 36- month follow-up. These data are also confirmed in age-related subgroups, suggesting the ECW % assessment can be a simple and useful parameter to evaluate for targeted treatment choices in patients with chronic HD.

INFLUENCE OF THERAPEUTIC GYMNASTICS ON BODY WEIGHT COMPOSITION, ANTHROPOMETRIC PARAMETERS AND QUALITY OF LIFE OF WOMEN WITH OBESITY IN THE CONDITIONS OF QUARANTINE RESTRICTIONS IN THE CONTEXT OF THE COVID-19 PANDEMIC.

The aim: To determine the effectiveness of application of special therapeutic physical exercises to improve the indicators of body weight, anthropometric parameters and quality of life of obese women in the conditions of quarantine restrictions. Materials and methods: We examined 10 women aged 37 ± 5 years with obesity of various degrees, which was determined by the body mass index (BMI, kg/m2). All women for two months were involved in specially designed therapeutic exercises in the remote mode. Evaluation of the effectiveness of therapeu¬tic exercises use was performed using the survey method to determine the quality of life of obese women according to a short version of the questionnaire "The world health organization quality of life (WHOQOL-BREF)"; anthropometric measurements of body parts sizes; bioimpedance analysis of body weight composition; statistical methods of data processing. Results: The effect of therapeutic gymnastics according to the proposed programme on the component composition of body weight of obese women was proved, which indicates a decrease in total body weight, reduction of body fat, increase in total body water and muscle component of body weight. It is shown that under the influence of corrective physical exercises the proportions of the body of women changed, as evidenced by the dynamics of the circumferences of all measured parts of the body of obese women. The improvement of women's quality of life in all indicators was identified. Conclusions: The use of special complexes of physical exercises, aimed at correction of the body weight of obese women,showed its significant effectiveness and led to the expected result.

Effect of multiday endurance exercise on total body water and calculated body composition in racing sled dogs

Prolonged multiday exercise in dogs is often associated with a caloric deficit that can lead to changes in body composition but may also result in an increase in lean body mass due to a conditioning effect. To test the hypothesis that multiday exercise decreases fat mass but increases lean body mass, body composition was measured using deuterium oxide dilution in a team of racing Alaskan sled dogs competing in a multiday race. Twelve dogs completed 961 km in 6 days, resulting in a 3% decrease in body mass (P=0.003) and 16% decrease in body fat (P=0.005), and an increase in total body water as a fraction of body mass (P=0.01). Within the study population, there was considerable dog-to-dog variation, with 2 dogs gaining fat mass and 2 dogs losing over 40% of their pre-race fat mass during the measurement period. These results confirm that dogs participating in multiday exercise events are at risk for loss of body fat reserve, likely due to a net calorie deficit. However, individual dog responses to an exercise challenge can be highly variable, emphasizing the need for careful assessment of individual dogs.

Mediterranean Diet versus Very Low-Calorie Ketogenic Diet: Effects of Reaching 5% Body Weight Loss on Body Composition in Subjects with Overweight and with Obesity-A Cohort Study.

The best nutritional strategy to fight the rise in obesity remains a debated issue. The Mediterranean diet (MD) and the Very Low-Calorie Ketogenic diet (VLCKD) are effective at helping people lose body weight (BW) and fat mass (FM) while preserving fat-free mass (FFM). This study aimed to evaluate the time these two diets took to reach a loss of 5% of the initial BW and how body composition was affected. We randomized 268 subjects with obesity or overweight in two arms, MD and VLCKD, for a maximum of 3 months or until they reached 5% BW loss. This result was achieved after one month of VLCKD and 3 months of MD. Both diets were effective in terms of BW (p < 0.0001) and FM loss (p < 0.0001), but the MD reached a higher reduction in both waist circumference (p = 0.0010) and FM (p = 0.0006) and a greater increase in total body water (p = 0.0017) and FFM (p = 0.0373) than VLCKD. The population was also stratified according to gender, age, and BMI. These two nutritional protocols are both effective in improving anthropometrical parameters and body composition, but they take different time spans to reach the goal. Therefore, professionals should evaluate which is the most suitable according to each patient’s health status.

The Use of Compression Stockings to Reduce Water Retention in the Legs During Gaming and Esports: Randomized Controlled Field Study.

BackgroundWith the increasing digitalization of daily life, internet-based entertainment such as gaming and streaming has advanced to one of the megatrends of the 21st century. Besides offering a multitude of controversially discussed opportunities for entertainment and social interaction, there is reasonable concern about health issues caused by the absence of physical activity among activities linked to gaming and streaming.ObjectiveThe aim of this study is to compare the water balance of recreational gamers with and those without compression stockings during a gaming event.MethodsWe measured body composition and water balance with 8-electrode bioelectrical impedance analysis among 46 recreational gamers with an average age of 27.1 (SD 6.5) years (5/46, 11% women and 41/46, 89% men) before and after 24 hours at a gaming event. Of the 46 gamers, 23 (50%) gamers wore compression stockings for the duration of the study.ResultsOur study shows that prolonged gaming and associated behaviors during a 24-hour time frame lead to an increase in total body water (+0.76 L; P<.001) and a decrease of phase angle in the lower extremities (−0.47°; P<.001) but not in the upper extremities (+0.09°; P=.80), when no compression is used. Gamers using compression socks did not show any significant negative effects on their body composition.ConclusionsProlonged gaming and streaming are serious risk factors for diseases associated with water retention in the legs, and these risks can be measured by bioelectrical impedance and reduced by wearing compression stockings. We conclude that these findings should be discussed and replicated in larger studies and that there is a considerably large market for compression stockings among gamers and live streamers.

Body Composition in Adolescent PKU Patients: Beyond Fat Mass.

There is a lack of evidence on the impact on body composition of high protein intake and types of protein substitutes in PKU patients—particularly in adolescents, who are more inclined to dietary transgressions. In this observational, cross-sectional study, PKU patients were observed during prepubertal age (p) or after the pubertal spurt (P), assessing body composition and bone quality and correlating these parameters with dietary compliance and types of protein substitutes. Anthropometric and dietary data were evaluated together with bioelectrical impedance analysis (BIA), quantitative ultrasound (QUS) and branched-chain amino acids (BCAAs). A total of 36 patients (16 males, 17 prepubertal and 19 post-pubertal; mean ± SD age 11.4 ± 3.9 years) were included. A higher BMI was observed in adolescents (p-value: 0.018). The BIA revealed a significant increase in total body water (TBW) and muscle mass (MM) in P subjects either compliant (p-value: 0.001) or non-compliant with the diet (p-value: 0.001). MM content correlated with increased Phe intake (r = 0.63; p < 0.001). In the subgroup of five patients taking L-AAs and glycomacropeptides (GMPs), BCAA values tended to be lower than those taking only L-AA mixtures, with a significant trend for valine. Maintenance of body composition parameters within the normal range—for both fat and muscle mass—and levels of BCAAs can be helpful in reducing the risk of becoming overweight in adulthood. Further studies are needed to confirm these findings.

Body Fluid Estimation Via Segmental Multi-Frequency Bioelectrical Impedance Analysis Following Acute Resistance Exercise

Segmental multi-frequency bioelectrical impedance analysis (S-MFBIA) estimates body composition and fluids by passing electrical currents through the body and can separate the body into distinct segments. The minimum required abstention from exercise before S-MFBIA is unclear. PURPOSE: The purpose of this study was to monitor changes in total body water (TBW), intracellular water (ICW), and extracellular water (ECW) estimated via S-MFBIA following acute, localized bouts of resistance exercise (RE). METHODS: Thirty-two female (n = 18; age: 22.7 ± 1.4 y; height: 167.5 ± 7.5 cm; body mass: 66.6 ± 14.5 kg; body fat: 30.3 ± 6.2%) and male (n = 14; age: 24.2 ± 2.9; height: 178.7 ± 5.3; body mass: 85.7 ± 7.8 kg; body fat: 19.6 ± 6.9%) resistance-trained volunteers completed three randomly assigned conditions in a crossover design. Each RE protocol (REUPPER or RELOWER) consisted of three exercises and began with two warm-up sets of 12-15 repetitions per exercise. This was followed by a RE circuit of 5 sets of 10 repetitions per exercise with a one-minute rest interval between circuits. In the resting (REST) condition, participants did not complete any physical activity. S-MFBIA was performed at five timepoints: pre-exercise, immediate post-exercise, 15-, 30-, and 60-minutes post-exercise. Data were analyzed using linear mixed-effects models with a random intercept for participant. In all models, REST was the reference condition, and pre-exercise was the reference time point. RESULTS: Although body mass did not differ between conditions, condition by time interactions were observed for TBW, ICW, and ECW (p < 0.001 each), with the higher values observed at post-exercise time points in REUPPER as compared to the REST condition. Mean differences between REUPPER and REST for TBW, ICW, and ECW ranged from 0.6-1.0 kg, 0.4-0.6 kg, and 0.2-0.4 kg, respectively. Conversely, RELOWER did not alter fluid estimates. CONCLUSIONS: An acute increase in TBW, ICW, and ECW is detected by S-MFBIA after a single bout of upper body, but not lower body, RE. This could be due to the smaller initial diameter and greater relative change in diameter of the arms as compared to legs. Due to the potential of artificial body fluid changes, users should avoid exercise - particularly upper body exercise - prior to S-MFBIA assessments.

Modified technique for estimating total body water in live animals using Antipyrine substance for measuring thermal tolerances

Estimating the total body water (TBW) in the live animals using the Antipyrine (ANP) substance as a modified technique was the first objective of this research. TBW was estimated in vivo in ten native bovine calves using the conventional method (extrapolation technique) and also by the suggested modified method (equilibration technique). The averages of TBW in native bovine calves were 136.5±16 and 133.1±16 liters by convention and modified technique, respectively, without significant differences between the two techniques. The accuracy of the modified technique was 97.5 % as compared with the convention method and at the same time, the new method is an easy, simple, accurate and quick technique and more reliable. Estimation of heat adaptability of animals to heat stress conditions was the second objective of this research. Animals when exposed to high ambient temperature the TBW increases and consequently TBS (Live body weight-TBW) decreases with different percentages according to the animal response to stressful conditions. TBW or TBS values were estimated before and after heat stress exposure and the percentage change in TBW or TBS in the animal due to heat stress may be used for evaluating the animal's adaptability to heat stress. The percentage increase in TBW or the percentage decrease in TBS due to heat stress conditions may be used as an index for heat-tolerance coefficient (HTC). The most heat- tolerance animals are those with the highest HTC values.

Chronic capsiate supplementation increases fat-free mass and upper body strength but not the inflammatory response to resistance exercise in young untrained men: a randomized, placebo-controlled and double-blind study

BackgroundAcute capsaicinoid and capsinoid supplementation has endurance and resistance exercise benefits; however, if these short-term performance benefits translate into chronic benefits when combined with resistance training is currently unknown. This study investigated changes of chronic Capsiate supplementation on muscular adaptations, inflammatory response and performance in untrained men.MethodsTwenty untrained men were randomized to ingest 12 mg Capsiate (CAP) or placebo in a parallel, double-blind design. Body composition and performance were measured at pre-training and after 6 weeks of resistance training. An acute resistance exercise session test was performed pre and post-intervention. Blood samples were collected at rest and post-resistance exercise to analyze Tumor necrosis factor- (TNF-), Soluble TNF- receptor (sTNF-r), Interleukin-6 (IL-6) and Interleukin-10 (IL-10).ResultsExercise and CAP supplementation increased fat-free mass in comparison to baseline by 1.5 kg (P < 0.001), however, the majority of the increase (1.0 kg) resulted from an increase in total body water. The CAP change scores for fat-free mass were significantly greater in comparison to the placebo (CAP ∆%= 2.1 ± 1.8 %, PLA ∆%= 0.7 ± 1.3 %, P = 0.043) and there was a significant difference between groups in the bench press exercise (P = 0.034) with greater upper body strength change score for CAP (∆%= 13.4 ± 9.1 %) compared to placebo (∆%= 5.8 ± 5.2 %), P = 0.041. CAP had no effect on lower body strength and no supplementation interactions were observed for all cytokines in response to acute resistance exercise (P > 0.05).ConclusionChronic Capsiate supplementation combined with resistance training during short period (6 weeks) increased fat-free mass and upper body strength but not inflammatory response and performance in young untrained men.

Fluid Status After Cardiac Surgery Assessed by Bioelectrical Impedance Vector Analysis and the Effects of Extracorporeal Circulation

Hydration status after cardiac surgery can be difficult to assess, often requiring invasive measurements. Bioelectrical impedance vector analysis (BIVA) is based on patterns of resistance (R) and reactance (Xc), corrected by height, and has been used in various clinical scenarios to determine body composition and monitor its changes over time. The purpose of the present study was to apply this method in cardiac surgery patients to assess the variation in hydration status and to compare its changes according to the use of extracorporeal circulation. Single-center, observational, prospective study including patients older than 18 years undergoing elective or urgent cardiac surgery. Intensive cardiac care unit of a tertiary center in a metropolitan area. The study comprised 76 patients with a median age of 60 years and mostly undergoing coronary artery bypass grafting (CABG) (n = 47 [61.8%]) with extracorporeal circulation (n = 54 [73%]). Bioimpedance was measured with a standard tetrapolar single-frequency bioimpedance meter using a standardized procedure and plotted in an R-Xc graph. The study demonstrated an increase in total body water immediately after surgery that was sustained until producing hyperhydration 24 hours later. Off-pump CABG was associated with a normal hydration status after surgery, whereas on-pump CABG produced a significant increase in total body water. Fluid status assessment with BIVA in cardiac surgery showed an increase in total body water up to 24 hours after surgery. Off-pump surgery prevented overhydration, which partially could explain the reduction in some of the postoperative complications. BIVA could serve as a useful method for monitoring fluid status in the setting of goal-directed therapy to assist in maintaining euvolemia in cardiac surgical patients.

Cardiovascular Protection of Nephropathic Male Patients by Oral Food Supplements.

Nephropathic patients show elevated cardiovascular morbidity and mortality compared to the general population. In order to delve deeper into the understanding of this phenomenon, it is necessary to recognize risk factors that are distinctive to the uremic state, such as oxidative stress and chronic low-grade inflammation. Moreover, gender differences have been reported in nephrology, as it has been observed that chronic kidney disease has higher prevalence in males than in females. The use of an oral food supplement (OFS) containing natural active compounds from Capsicum annuum L., Garcinia cambogia, Centella asiatica L., artichoke, and Aesculus hippocastanum L. which are virtually devoid from side effects, but rich in antioxidant and antiradical properties, could represent a valid therapeutic adjunct in the clinical management of nephropathic patients. Moreover, quantitative analysis performed in vitro on such compounds showed that they expressed good total antioxidant (7.28 gallic acid equivalents) and antiradical activity (above 80%). In this study, 23 male nephropathic patients and 10 age and body composition parameter matched healthy males (control group) were enrolled and took 3 cps/day of OFS for 5 weeks. At the end of the study, the nephropathic patient group showed a statistically significant reduction in the following laboratory parameters: total cholesterol (TC) (p = 0.044), atherogenic index TC/high-density lipoprotein cholesterol (p = 0.010), inflammatory parameters (C-reactive protein, p = 0.048, and erythrocyte sedimentation rate, p = 0.019), systolic (p = 0.044), and diastolic arterial blood pressure (p = 0.003). Regarding body composition, there was an increase in total body water % (p = 0.035) with redistribution of extracellular water % (p = 0.030) and intracellular water % (p = 0.049). In the control group, there was a reduction in fat mass % (p = 0.017) and extracellular water % (p = 0.047). Therefore, this OFS may represent a valid adjunct therapy to counteract comorbidities related to uremia.

Identifying Athlete Body Fluid Changes During a Competitive Season With Bioelectrical Impedance Vector Analysis.

To analyze the association between body fluid changes evaluated by bioelectrical impedance vector analysis and dilution techniques over a competitive season in athletes. A total of 58 athletes of both sexes (men: age 18.7 [4.0]y and women: age 19.2 [6.0]y) engaging in different sports were evaluated at the beginning (pre) and 6 months after (post) the competitive season. Deuterium dilution and bromide dilution were used as the criterion methods to assess total body water (TBW) and extracellular water (ECW), respectively; intracellular water (ICW) was calculated as TBW-ECW. Bioelectrical resistance and reactance were obtained with a phase-sensitive 50-kHz bioelectrical impedance analysis device; bioelectrical impedance vector analysis was applied. Dual-energy X-ray absorptiometry was used to assess fat mass and fat-free mass. The athletes were empirically classified considering TBW change (pre-post, increase or decrease) according to sex. Significant mean vector displacements in the postgroups were observed in both sexes. Specifically, reductions in vector length (Z/H) were associated with increases in TBW and ICW (r = -.718, P < .01; r = -.630, P < .01, respectively) and decreases in ECW:ICW ratio (r = .344, P < .05), even after adjusting for age, height, and sex. Phase-angle variations were positively associated with TBW and ICW (r = .458, P < .01; r = .564, P < .01, respectively) and negatively associated with ECW:ICW (r = -.436, P < .01). Phase angle significantly increased in all the postgroups except in women in whom TBW decreased. The results suggest that bioelectrical impedance vector analysis is a suitable method to obtain a qualitative indication of body fluid changes during a competitive season in athletes.

Hyponatremia in dogs and cats.

To review the pathophysiology, diagnostic approach, and treatment recommendations for hyponatremia in dogs and cats. Hyponatremia almost always results from an increase in total body water (TBW), and not from loss of sodium. Abnormalities in antidiuretic hormone (ADH) are commonly part of the etiology of hyponatremia. Diagnosis of hyponatremia focuses on the cause of the increase of TBW. Assessment of the patient's volume status and measurement of urine sodium concentration are important factors. Measurement or calculated estimation of plasma osmolality can also guide the assessment of hyponatremia. Too rapid correction of serum sodium can precipitate osmotic demyelination syndrome. As a general rule, serum sodium concentration should be raised ≤10mmol/L over 24 hours, but rapid increases in serum sodium are indicated if neurologic abnormalities are evident. Serum sodium can be increased using hypertonic saline, with dosing based on the patient's calculated sodium deficit. Treatment of the underlying cause of water ingestion or retention is also required to fully resolve hyponatremia. Mortality rates are significantly higher in dogs and cats with hyponatremia compared to those with normal serum sodium concentrations, even in patients with mild hypontremia (<5mmol/L below the lower value of the reference interval). Hyponatremia is also associated with increased risk of death if present during specific disease states in dogs.

Bioelectrical impedance analysis does not detect an increase in total body water following isotonic fluid consumption.

To determine if single-frequency foot-to-foot bioelectrical impedance analysis (BIA) can detect acute changes in total body water (TBW) following consumption of isotonic saline. All participants ate a sodium-free meal at 4 h prior to the data collection visit and had euhydration confirmed using urine specific gravity at the beginning of the experimental visit. Subjects drank 466 mL of isotonic saline (Na+ 140 mmol·L-1) following baseline measures. Blood sampling and BIA were performed at baseline and every 30 min for 3 h after saline consumption. Ten healthy participants completed this study. Plasma volume (5%Δ, p < 0.001) and serum sodium concentration (1%Δ, p < 0.001) increased by 60 min and 90 min, respectively. Body mass (p < 0.001) displayed a biphasic response increasing to a peak at 30 min (+0.38Δkg) and then decreasing to its minimum at 180 min (-0.35Δkg). BIA impedance (p = 0.678) was unaffected by the saline administration. BIA-derived TBW (p = 0.039) decreased from baseline starting at 150 min (0.21Δkg). Novelty Athletes and coaches wishing to achieve hyperhydration can do so through the consumption of isotonic fluid. 50 kHz foot-to-foot BIA-derived TBW is inadequate for measuring hyperhydration. Future studies should examine the physiological and performance effects of such a hyperhydration protocol.

Sodium Handling by the Blood Vessel Wall

Extensive research has focused on the association between high-sodium intake and hypertension. New ideas about sodium homeostasis decisively influence the existing ideas about this association. Classically, according to the 2-compartment model, sodium particularly accumulates in the extracellular space, where it equally divides between the intravascular and the interstitial compartment. This is followed by commensurate water retention to maintain normal osmolality. The consequent increase in extracellular volume was considered to be the main causative factor for hypertension. However, consecutive studies revealed that increases in sodium load were neither accompanied by the expected increases in total body water or body weight nor could be accounted for by the excreted amounts of sodium in the urine.1–3 In other words, sodium was missing. Accordingly, the existence of nonosmotic sodium buffers was suggested.3 In this review, we will speculate on the implications of this missing sodium with regard to blood pressure regulation by discussing the journey that sodium undertakes from the circulation and state that sodium handling by the blood vessel wall seems crucial in the development and prevention of hypertension. Two meticulously performed balance studies in 2000 and 2002 were the first to point out that something was amiss in the common view about sodium homeostasis. In 2000, Heer et al2 revealed that, in contrast to the common thought, an increase in body sodium induced by high-sodium diet was not paralleled by an increase in total body water. Subsequently, Titze et al3 executed a long-term study of 135 days in healthy volunteers who were confined to spaceflight stimulating conditions. Sodium and other electrolyte intake were carefully monitored. Toward the end of the study, sodium gain exceeded weight gain, which introduced the possibility of a nonosmotic sodium storage compartment. A few years later, this hypothesis was confirmed, as rats …

Impact of Acute Dietary Manipulations on DXA and BIA Body Composition Estimates.

To examine the effects of acute preassessment diets on body composition estimates obtained by dual-energy x-ray absorptiometry (DXA) and bioelectrical impedance analysis (BIA). In a counterbalanced design, 48 males and females were provided with two 1-d diets: high-carbohydrate diet (9 g CHO·kg) and very low-carbohydrate diet (1 to 1.5 g CHO·kg). For each condition, body composition was assessed in the morning after an overnight fast, in the afternoon after feeding, and the following morning after a second overnight fast. Acute food ingestion, regardless of macronutrient content, altered DXA and BIA body composition estimates, and both sexes responded similarly. DXA total and regional lean soft tissue estimates increased up to 1.7% and 3% on average in response to feeding, with individual increases of over 4.5% and 9%. DXA total and trunk fat mass estimates decreased by up to 3% on average. All DXA-derived measures of body composition returned to baseline values after the second overnight fast. Impedance measured by BIA decreased by 4.4% in response to feeding, leading to a 2% increase in total body water and fat-free mass, with individual increases up to 4.5%. BIA fat mass estimates decreased 1.4% to 2.4%, with individual decreases of up to 10%. Unlike DXA, most BIA-derived estimates did not return to baseline values after a second overnight fast. Acute food and fluid intake can artificially influence body composition estimates, regardless of macronutrient content. An overnight fast is likely sufficient preassessment dietary control for DXA and possibly sufficient for BIA.

The effectiveness of nutritional-sensitive approach to restore physical activity in cachexic female palliative patients: A randomized controlled trial.

258 Background: Loss of lean body mass, body fat along with inflammation characterizes cachexia in patients with cancer. Nutrition intervention with counseling may ameliorate undernutrition and metabolic alterations. The aim of this study was to improve nutritional status and quality of life by providing nutrients dense natural food (IAtta) along with counseling. Methods: Female patients with cancerwith symptoms of cachexia were randomly distributed into placebo (n = 75) and intervention group (n = 75). Patients were recruited from the palliative clinic, Oncology department in AIIMS, New Delhi, India. In addition to nutritional counseling, patients were instructed to consume 100g nutritional supplement on daily basis with their normal dietary intake and for six months period. The intervention group received 100g of IAtta while placebo group received 100g of whole wheat flour. Body weight – BW; mid upper arm circumference - MUAC, physical activity level - PAL, quality of life – QoL domains and total body water (TBW) were assessed at baseline, three months and after six months. Study variables were analyzed using repeated-measures ANOVA and the Friedman test (P-value &lt; 0.05; 95% confidence interval). Results: After 6 months,patients in group IAtta had significant improvement in PAL and QoL domain (global health status, p &lt; 0.001 and fatigue, p = 0.001). Despite the decrease in BW from 43.3 ± 7.0 to 41.6 ± 5.7 Kg (p = 0.014), TBW and MUAC (p = 0.068) were maintained. Conversely, the QoL in placebo group did not improve (global health status, p = 0.74) neither their PAL. Moreover, significant increase in TBW (due to water retention) and BW (from 42.6±7.1 to 43.5±7.4 Kg, p = 0.001). Conclusions: Nutrition-sensitive approach (IAtta meal), along with nutrition counseling, improve quality of life and physical activity in female cachexia palliative patients with cancer. Clinical trial information: NCT02561143. [Table: see text]

Cardiovascular adaptations supporting human exercise-heat acclimation.

This review examines the cardiovascular adaptations along with total body water and plasma volume adjustments that occur in parallel with improved heat loss responses during exercise-heat acclimation. The cardiovascular system is well recognized as an important contributor to exercise-heat acclimation that acts to minimize physiological strain, reduce the risk of serious heat illness and better sustain exercise capacity. The upright posture adopted by humans during most physical activities and the large skin surface area contribute to the circulatory and blood pressure regulation challenge of simultaneously supporting skeletal muscle blood flow and dissipating heat via increased skin blood flow and sweat secretion during exercise-heat stress. Although it was traditionally held that cardiac output increased during exercise-heat stress to primarily support elevated skin blood flow requirements, recent evidence suggests that temperature-sensitive mechanisms may also mediate an elevation in skeletal muscle blood flow. The cardiovascular adaptations supporting this challenge include an increase in total body water, plasma volume expansion, better sustainment and/or elevation of stroke volume, reduction in heart rate, improvement in ventricular filling and myocardial efficiency, and enhanced skin blood flow and sweating responses. The magnitude of these adaptations is variable and dependent on several factors such as exercise intensity, duration of exposure, frequency and total number of exposures, as well as the environmental conditions (i.e. dry or humid heat) in which acclimation occurs.