Showing papers on "Body water published in 2015"

Changes in muscle and fat mass with haemodialysis detected by multi-frequency bioelectrical impedance analysis.

Abstract: Multi-frequency bioelectrical impedance analysis (MFBIA) is becoming more widely used to assess hydration status and body composition in haemodialysis patients. Most centres only measure MFBIA pre dialysis when patients are overhydrated. We wished to determine whether body composition assessments change post dialysis following fluid removal. Lean body and fat mass were measured by MFBIA pre and post haemodialysis in 676 stable outpatients. Weight fell post dialysis from 72.9±17.8 to 70.9±19.9 kg, P<0.001, soft lean mass from 48.2±12.1 to 45.4±11.0 kg and fat-free mass from 51.8±19.2 to 48.1±11.8 kg, P<0.001, whereas percentage body fat (PBF) increased from 28.8±11.9 to 30.8±12.1% post dialysis, P<0.001, with a mean increase post dialysis of 2.0% (95% confidence limits 1.55 to 2.45). There were correlations between the fall in total body water and extracellular water and skeletal muscle mass (r=0.826, P<0.001 and r=0.711, P<0.001, respectively), and negative correlation between the fall in total body water and ICW and the increase in PBF (r=−0.72, P<0.001, and −0.72, P<0.001, respectively). The relative changes were greater for the arms compared with the legs. Although more convenient for both patients and staff to undertake bioimpedance measurements pre dialysis, overhydration over estimates muscle mass and under estimates fat. For more reliable and reproducible assessments of nutritional status, we suggest that bioimpedance measurements of body composition should be made when patients are closer to their target weight than when overhydrated.

Effect of 12-week-long aerobic training programme on body composition, aerobic capacity, complete blood count and blood lipid profile among young women

Abstract: Background Numerous data suggest that aerobic-type exercise improves lipoprotein-lipid profiles, cardiorespiratory fitness and body composition in young women. The aim of this study was to evaluate the biological response to high-low impact aerobic fitness among young women. Materials and methods Thirty-four young women aged 22 (19-24) years were divided into three groups: underweight (N=10), normal weight (N=12) and overweight (N=12). Aerobic capacity, anthropometry and body composition together with complete blood count and lipid profile were determined before and after completion of a 12-week-long training period. Results The training programme caused a significant decrease in weight (by 4.3 kg, P=0.003), body mass index (by 1.3 kg/m2, P=0.003), free fat mass (by 2.1 kg, P=0.002), total body water (by 0.4 kg, P=0.036), percentage of fat (by 3 percent points, P=0.002), all analyzed skinfolds thicknesses, as well as the lipid profile in overweight group, and no changes in normal weight group. Significant changes in weight (by 4.2 kg, P=0.005), body mass index (by 0.9 kg/m2, P=0.005), crus skinfold thickness (by 3.3 mm, P=0.028), and in maximum oxygen uptake (by 2.49 mL/kg/min; P=0.047) were observed among underweight women. No change in total blood count was observed in all groups. Conclusion Twelve-week-long fitness training programme of two alternating styles (low and high impact) has a beneficial effect on overweight young women.

Fluid overload at start of continuous renal replacement therapy is associated with poorer clinical condition and outcome: a prospective observational study on the combined use of bioimpedance vector analysis and serum N-terminal pro-B-type natriuretic peptide measurement.

Abstract: It is unclear whether the fluid status, as determined by bioimpedance vector analysis (BIVA) combined with serum N-terminal pro-B-type natriuretic peptides (NT-pro-BNP) measurement, is associated with treatment outcome among patients receiving continuous renal replacement therapy (CRRT). Our objective was to answer this question. Patients who were in the intensive care units of a university teaching hospital and who required CRRT were screened for enrollment. For the enrolled patients, BIVA and serum NT-pro BNP measurement were performed just before the start of CRRT and 3 days afterward. According to the BIVA and NT-pro BNP measurement results, the patients were divided into four groups according to fluid status type: type 1, both normal; type 2, normal BIVA results and abnormal NT-pro BNP levels; type 3, abnormal BIVA results and normal NT-pro BNP levels; and type 4, both abnormal. The associations between fluid status and outcome were analyzed. Eighty-nine patients were enrolled, 58 were males, and the mean age was 49.0 ± 17.2 years. The mean score of Acute Physiology and Chronic Health Evaluation II (APACHE II) was 18.8 ± 8.6. The fluid status before CRRT start was as follows: type 1, 21.3% (19 out of 89); type 2, 16.9% (15 out of 89); type 3, 11.2% (10 out of 89); and type 4, 50.6% (45 out of 89). There were significant differences between fluid status types before starting CRRT on baseline values for APACHE II scores, serum creatinine, hemoglobin, platelet count, urine volume, and incidences of oliguria and acute kidney injury (P <0.05). There were significant differences between patients with different fluid status before CRRT start on hospital mortality—type 1, 26.3% (5 out of 19); type 2, 33.3% (5 out of 15); type 3, 40% (4 out of 10); and type 4, 64.4% (29 out of 45) (P = 0.019)—as well as renal function recovery rates: type 1, 57.1% (4 out of 7); type 2, 67.7% (6 out of 9); type 3, 50% (3 out of 6); and type 4, 23.7% (9 out of 38) (P = 0.051). Fluid status abnormalities were common among patients receiving CRRT. Different types of fluid status distinguished by BIVA combined with serum NT-pro BNP measurements corresponded to different clinical conditions and treatment outcomes, which implies a value of this method for evaluation of fluid status among patients receiving CRRT.

Time course of supine and standing shifts in total body, intracellular and extracellular water for a sample of healthy adults

Abstract: Traditional tetrapolar bioimpedance spectroscopy (BIS) is performed with the participant supine for 10 min. New vertical analyzers are penetrating clinical, home and fitness markets, but have body water values that differ from supine reference measures. The minimum time standing prior to assessment does not appear in the literature. We investigated the time course of body water shifts in healthy adults undergoing 30-min assessments in supine and vertical positions. While seated, participants were prepped for standard tetrapolar electrode placement. Starting position was counterbalanced and body water measurements were taken every 5 min for 30 min in both positions. Participants sat for 2 min prior to switching positions. Of the 64 participants, three were unable to stand for 30 min; their data were excluded. Body size differences were minimized via computation of relative (%) change between time intervals for total body water (TBW), extracellular water (ECW) and intracellular water (ICW). ECW and ICW shifted in opposite directions while participants were supine; as ECW decreased at each time point, ICW increased (P<0.0125). Likewise, when participants stood, ECW increased incrementally (P<0.0125), but the decreases in ICW were not significant. At each time interval, the changes in supine ECW and ICW differed from the standing values (P<0.05). No postural or time differences were found for %change TBW. For TBW, 5 min appears sufficient for fluid stabilization in either position. Supine ECW and ICW stabilization require more than 30 min as does standing ECW.

Association between neck and shoulder pain, back pain, low back pain and body composition parameters among the Japanese general population.

Abstract: Neck and shoulder pain, back pain and low back pain are common symptoms in Japanese subjects, and it is important to elucidate the pathology and associated factors of these pains due to their frequency and impact on the quality of life (QOL) and activities of daily living (ADL). The purpose of the present study was to investigate whether body composition is associated with these pains. We collected the data of 273 Japanese subjects regarding the presence and the visual analogue scale (VAS) of neck and shoulder pain, back pain, low back pain and body composition parameters calculated using bioelectrical impedance analysis (BIA) technology. Furthermore, we investigated the association between these pains and the body composition using statistical methods. According to a multivariate analysis adjusted for age and gender, lower total body water ratio was significantly associated with the presence of neck and shoulder pain at present (P < 0.05); additionally, total body muscle mass (standardized β = −0.26, 95 % CI, −0.17 - -0.008, P < 0.05), total body water (standardized β = −0.27, 95 % CI, −0.23 - -0.04, P < 0.01), appendicular muscle mass (standardized β = −0.29, 95 % CI, −0.36 - -0.04, P < 0.05), and the appendicular muscle mass index (AMI) (standardized β = −0.24, 95 % CI, −1.18 - -0.20, P <0.01) were negatively correlated with the VAS of neck and shoulder pain, whereas no body composition parameters were significantly associated with back pain, low back pain at present and any type of chronic pain. The present study demonstrated that some body composition parameters regarding body water and body muscle were associated or correlated with the presence or intensity of neck and shoulder pain.

Comparison of hydration and nutritional status between young and elderly hemodialysis patients through bioimpedance analysis.

Abstract: The number of elderly people on dialysis is increasing rapidly. Fluid overload and malnutrition status are serious problems in elderly dialysis patients. We aimed to compare the hydration and nutritional status through bioimpedance analysis (BIA) between young and elderly hemodialysis (HD) patients and to analyze risk factors related to fluid overload and malnutrition status in these patients.We conducted a cross-sectional study, in which 82 HD (males 42, mean age 58.7±12.9 years) patients were enrolled. We collected different types of data: laboratory data, such as serum creatinine, albumin, total iron-binding capacity, hemoglobin, total cholesterol; anthropometric data, such as hand grip strength (HGS); BIA data, such as intracellular water, skeletal muscle mass, body cell mass, bone mineral content, phase angle (PhA), extra cellular water (ECW)/total body water (TBW) ratio; and malnutrition-inflammation score (MIS), which is a traditional nutritional parameter for dialysis patients. All patients were stratified into two groups according to their age: young (<65 years [n=54]) and elderly (≥65 years [n=28]).Total iron-binding capacity and HGS were significantly lower in elderly HD patients than in young HD patients (198.9±35.6 vs 221.4±52.1 mcg/dL; and 22.4±10.3 vs 36.4±23.2 kg, respectively) (P<0.05). Also, intracellular water and PhA measured by BIA were significantly lower (18.3±4.0 vs 20.3±4.2 L [P=0.043]; and 4.0±1.0 vs 4.9±1.2° [P=0.002], respectively), and ECW/TBW were higher in elderly HD patients (0.40±0.01 vs 0.39±0.01 [P=0.001]). ECW/TBW was positively associated with age (P<0.001) and the presence of diabetes (P<0.001) and was negatively associated with sex (P=0.001), albumin (P<0.001), urine volume (P=0.042), HGS (P<0.001), and PhA by BIA (P<0.001). MIS was negatively related to sex (P=0.001), albumin (P<0.001), HGS (P=0.001), and PhA (P<0.001) in HD patients. On multivariate analysis, older age (P=0.031), the presence of diabetes (P=0.035), and decreased PhA (P<0.001) were independent risk factors for increased ECW/TBW, representative of fluid overload status, whereas only decreased PhA (P=0.008) was a significant factor for MIS, representative of malnutrition status in these HD patients.We found that fluid overload and malnutrition status were more common in elderly HD patients compared with young HD patients. PhA was a significant independent factor in fluid overload status and malnutrition in these HD patients. Thus, our results indicated that PhA assessed by BIA might be a clinically useful method for assessing nutritional and hydration status in elderly HD patients.

Mean Expected Error in Prediction of Total Body Water: A True Accuracy Comparison Between Bioimpedance Spectroscopy and Single Frequency Regression Equations

Abstract: Mean Expected Error in Prediction of Total Body Water. : A True Accuracy Comparison between Bioimpedance Spectroscopy and Single Frequency Regression Equations.

Kinetics of plasma refilling during hemodialysis sessions with different initial fluid status.

Abstract: Removal of fluid excess from the plasma volume by ultrafiltration during hemodialysis (HD) is balanced by plasma refilling from the interstitium, driven mainly by the increase in plasma oncotic pressure. We calculated the plasma refilling coefficient (Kr, a parameter expressing the ratio of refilling rate to the increase in oncotic pressure) for nine patients, each undergoing two HD sessions differing by pretreatment fluid status and session time (shorter session, SH, 3.5 h, and longer session, LH, 4.5h). Relative blood volume change was measured online, and solute concentrations were measured regularly during the sessions. The volume of body compartments was measured by bioimpedance. The patients were more volume expanded before LH session (higher initial body mass and total body water). Oncotic pressure was similar for both sessions. The refilling rate, despite higher fluid overload in the LH sessions, was similar for both sessions. The final Kr values stabilized on similar levels (SH: 136.6 ± 55.6 ml/mm Hg/h and LH: 150.7 ± 73.6 ml/mm Hg/h) at similar times, notwithstanding the difference in initial fluid overload between the two groups, suggesting that Kr at dry weight is relatively insensitive to the initial fluid status of the patient.

Estimation of body fluids with bioimpedance spectroscopy: state of the art methods and proposal of novel methods.

Abstract: Determination of body fluids is a useful common practice in determination of disease mechanisms and treatments. Bioimpedance spectroscopy (BIS) methods are non-invasive, inexpensive and rapid alternatives to reference methods such as tracer dilution. However, they are indirect and their robustness and validity are unclear. In this article, state of the art methods are reviewed, their drawbacks identified and new methods are proposed. All methods were tested on a clinical database of patients receiving growth hormone replacement therapy. Results indicated that most BIS methods are similarly accurate (e.g. < 0.5 ± 3.0% mean percentage difference for total body water) for estimation of body fluids. A new model for calculation is proposed that performs equally well for all fluid compartments (total body water, extra- and intracellular water). It is suggested that the main source of error in extracellular water estimation is due to anisotropy, in total body water estimation to the uncertainty associated with intracellular resistivity and in determination of intracellular water a combination of both.

Hydrogen and oxygen stable isotope fractionation in body fluid compartments of dairy cattle according to season, farm, breed, and reproductive stage.

Abstract: Environmental temperature affects water turnover and isotope fractionation by causing water evaporation from the body in mammals. This may lead to rearrangement of the water stable isotope equilibrium in body fluids. We propose an approach to detect possible variations in the isotope ratio in different body fluids on the basis of different homoeothermic adaptations in varying reproductive stages. Three different reproductive stages (pregnant heifer, primiparous lactating cow, and pluriparous lactating cow) of two dairy cattle breeds (Italian Friesian and Modenese) were studied in winter and summer. Blood plasma, urine, faecal water, and milk were sampled and the isotope ratios of H (2H/1H) and O (18O/16O) were determined. Deuterium excess and isotope-fractionation factors were calculated for each passage from plasma to faeces, urine and milk. The effects of the season, reproductive stages and breed on δ2H and δ18O were significant in all the fluids, with few exceptions. Deuterium excess was affected by season in all the analysed fluids. The correlations between water isotope measurements in bovine body fluids ranged between 0.6936 (urine-milk) and 0.7848 (urine-plasma) for δ2H, and between 0.8705 (urine-milk) and 0.9602 (plasma-milk) for δ18O. The increase in both isotopic δ values in all body fluids during summer is representative of a condition in which fractionation took place as a consequence of a different ratio between ingested and excreted water, which leads to an increased presence of the heavy isotopes. The different body water turnover between adult lactating cattle and non-lactating heifers was confirmed by the higher isotopic δ for the latter, with a shift in the isotopic equilibrium towards values more distant from those of drinking water.

Evaluation of simple body composition methods: Assessment of validity in prepubertal Chilean children

Abstract: The aim of this study was to assess the validity of body fatness estimations based on skinfolds and bioelectrical iImpedance analyses (BIA) measurements compared to a three-component model (3C model) in prepubertal Chilean children, considering potential differences by sex and nutritional status. Four hundred and twenty four Chilean children (198 females and 226 males) were assessed for body composition. Body fat percentage (BF%) was evaluated by Skinfold equations (Slaughter, Ramirez and Huang) and Bioelectrical impedance (BIA: Tanita BC-418MA) using both the equipment and the Ramirez equation. Measurements based on a 3C model constructed from total body water estimates by isotope dilution and from body volume estimates by air displacement plethysmography were used as gold standard. Coefficient of determination (R2) values were higher in overweight and in the whole group of both gender. All slopes were differed significantly from 1, and most intercepts were significantly different from 0. Skinfold Equations: an underestimation of BF% was found for all equations, being higher with the Slaughter equation. BIA: Tanita underestimated BF% in all groups, whereas Ramirez equation shows an overestimation. Skinfolds and bio-impedance equations serve well to rank children according to their BF%. However, these methods are not accurate for describing body composition in prepubertal Chilean children.

Association between body composition and retinal vascular caliber in children and adolescents.

Abstract: PURPOSE: To elucidate the relationship between body composition and retinal vascular caliber (RVC) in children and adolescents. METHODS: Participants aged 7 to 19 years were recruited from the Guangzhou Twin Eye Study cohort. Retinal vascular caliber was measured cross-sectionally from retinal images using a computer-aided program. The data were expressed as the central retinal arteriolar equivalent (CRAE) and central retinal venular equivalent (CRVE). Triceps skinfold thickness (TSFT) was measured using a skinfold caliper. Body composition was obtained through bioelectrical impedance analysis, providing fat mass (FM), fat mass index (FMI), fat-free mass (FFM), fat-free mass index (FFMI), body water mass (BWM), body water percentage (BWP), basal metabolic rate (BMR), and trunk fat percentage (TFP). RESULTS: A total of 731 participants were included. Among the younger children (7-11 years), there was no significant association between body composition and RVC (all P > 0.05). However, for the older children (12-19 years), increasing FM, FMI, TFP, TSFT, and BMI were associated with CRAE negatively (β = -0.20, -0.68, -0.18, -0.17, and -0.48, respectively, all P < 0.05) and with CRVE positively (β = 0.47, 1.26, 0.34, 0.37, and 0.78, respectively, all P < 0.05), after adjusting for age, sex, axial length, mean arterial blood pressure, and the fellow vascular diameter. In contrast, increase in BWP was associated with larger CRAE (β = 0.33, P = 0.001) and smaller CRVE (β = -0.64, P < 0.001). Similar associations also were observed in the analyses when the body composition parameters were divided into quartiles (all P < 0.05). CONCLUSIONS: In adolescents, greater body fat deposition is related to narrower retinal arterioles and wider retinal venules, and higher body water proportion is associated with retinal arterioles widening and retinal venules narrowing. Even during childhood, body composition might have an association with systemic microvasculature.

Body Fluid Composition

Abstract: 1. Amrish Jain, MD 1. Division of Nephrology and Hypertension, The Carman and Ann Adams Department of Pediatrics, Wayne State University School of Medicine, Children’s Hospital of Michigan, Detroit, MI. * Abbreviations: ADH: : antidiuretic hormone AVP: : arginine vasopressin BUN: : blood urea nitrogen DI: : diabetes insipidus ECF: : extracellular fluid FWD: : free water deficit GFR: : glomerular filtration rate ICF: : intracellular fluid SIADH: : syndrome of inappropriate antidiuretic hormone Sosm: : serum osmolality TBW: : total body water Body fluid composition is maintained in a normal physiologic range by regulatory mechanisms that control sodium and water metabolism. A detailed knowledge of the homeostatic mechanisms will help in understanding the pathogenesis and management of disorders of sodium and water balance. After completing this article, readers should be able to: 1. Understand the distribution of fluid and solute in different body compartments. 2. Demonstrate the homeostatic mechanisms involved in maintaining sodium and water metabolism. 3. Calculate osmolality and recognize the clinical importance of maintaining osmotic equilibrium. 4. Recognize common disorders of hypernatremia or hyperosmolality and evaluate and understand the role of calculating free water deficit in the treatment of these disorders. 5. Recognize common disorders of hyponatremia or hypo-osmolality, appreciate the role of urine sodium and urine osmolality in evaluation, and understand the importance of slow correction of these disorders. A 6-month-old infant presents to the emergency department with vomiting for 3 days. He is lethargic and has a weak cry. His vital signs reveal an elevated heart rate (140 beats per minute), and physical examination findings are remarkable for dry mucous membranes. His capillary refill is more than 2 seconds. His initial laboratory values are as follows: serum sodium, 122 mEq/L (122 mmol/L); blood urea nitrogen (BUN), 28 mg/dL (10 mmol/L); serum creatinine, 0.4 mg/dL (35 μmol/L); serum glucose, 90 mg/dL (5.0 mmol/L); and serum osmolality (Sosm), 260 mOsm/kg (260 mmol/kg). Urinalysis reveals a specific gravity of 1.030, pH 6.5, and negative results for blood, protein, leukocyte esterase, or nitrite. Additional urine studies reveal a urine osmolality of 900 mOsm/kg (900 mmol/kg) and a urine sodium level of 6 mEq/L (6 mmol/L). A detailed history also …

The associations of malnutrition and aging with fluid volume imbalance between intra- and extracellular water in patients with chronic kidney disease

Abstract: Objectives Fluid imbalance due to sodium retention and malnutrition can be characterized by the ratio of extracellular water (ECW) to intracellular water (ICW). We investigated whether the ECW/ICW ratio is a risk factor for adverse outcomes.

Soccer vs. running training effects in young adult men: which programme is more effective in improvement of body composition? Randomized controlled trial

Abstract: The aims of this study were: 1) To determine the effects of a 12-week recreational soccer training programme and continuous endurance running on body composition of young adult men and 2) to determine which of these two programmes was more effective concerning body composition. Sixty-four participants completed the randomized controlled trial and were randomly assigned to one of three groups: a soccer training group (SOC; n=20), a running group (RUN; n=21) or a control group performing no physical training (CON; n=23). Training programmes for SOC and RUN lasted 12-week with 3 training sessions per week. Soccer sessions consisted of 60 min ordinary five-a-side, six-a-side or seven-a-side matches on a 30-45 m wide and 45-60 m long plastic grass pitch. Running sessions consisted of 60 min of continuous moderate intensity running at the same average heart rate as in SOC (~80% HRmax). All participants, regardless of group assignment, were tested for each of the following dependent variables: body weight, body height, body mass index, percent body fat, body fat mass, fat-free mass and total body water. In the SOC and RUN groups there was a significant decrease (p < 0.05) in body composition parameters from pre- to post-training values for all measures with the exception of fat-free mass and total body water. Body mass index, percent body fat and body fat mass did not differ between groups at baseline, but by week 12 were significantly lower (p < 0.05) in the SOC and RUN groups compared to CON. To conclude, recreational soccer training provides at least the same changes in body composition parameters as continuous running in young adult men when the training intensity is well matched.

Normal values for segmental bioimpedance spectroscopy in pediatric patients.

Abstract: Introduction Localized limb edema is a clinically relevant sign in diseases such as post-thrombotic syndrome and lymphedema. Quantitative evaluation of localized edema in children is mainly done by measuring the absolute difference in limb circumference, which includes fat and fat-free mass. Bioimpedance spectroscopy (BIS) provides information on the fluid volume of a body segment. Our objective was to determine normal ranges for segmental (arm and leg) BIS measurements in healthy children. Additionally, we determined the normal ranges for the difference in arm and ankle circumference and explored the influence of handedness and the correlation between techniques. Methods Healthy children aged 1-18 years were recruited. The ratio of extracellular fluid content between contralateral limbs (estimated as the inter-arm and inter-leg extracellular impedance ratio), and the ratio of extracellular to intracellular fluid content for each limb (estimated as the intracellular to extracellular impedance ratio) were determined with a bioimpedance spectrometer. Arm and ankle circumference was determined with a Gulick II tape. Results We recruited 223 healthy children (48 infants, 54 preschoolers, 66 school-aged children, and 55 teenagers). Normal values for arm and leg BIS measurements, and for the difference in arm and ankle circumference were estimated for each age category. No influence of handedness was found. We found a statistically significant correlation between extracellular impedance ratio and circumference difference for arms among teenagers. Conclusion We determined normal BIS ranges for arms and legs and for the difference in circumference between arms and between ankles in children. There was no statistically significant correlation between extracellular impedance ratio and difference in circumference, except in the case of arms in adolescents. This may indicate that limb circumference measures quantities other than fluid, challenging the adequacy of this technique to determine the presence of localized edema in most age groups.

Exercise-associated hyponatremic encephalopathy and exertional heatstroke in a soldier: High rates of fluid intake during exercise caused rather than prevented a fatal outcome.

Abstract: Athletes are often advised to drink in order to "fully replace bodyweight losses" in order to prevent exertional heatstroke (EHS) during exercise in the heat. There is little evidence that "dehydration" in the range experienced by athletes adversely affects thermoregulation or is the exclusive cause of EHS. In contrast it is established that excess fluid intake can cause exercise-associated hyponatremia (EAH) sometimes associated with encephalopathy (EAHE). As part of a series of experiments to determine optimal fluid replacement during exercise in the heat, we studied a group of exceptionally well-conditioned and heat-adapted members of the South African National Defence Force. A 20 year old male started a time restricted 50 km route-march in a dry bulb temperature that reached 37.5°C (WBGT of 33.6°C, relative humidity of 85%). Pre-march plasma osmolality, serum [Na(+)] and total body water measures indicated euhydration. Fluid was available ad libitum and isotonic sports drinks at 5 km intervals. Fluid intake and core body temperature (Tc) were recorded throughout while he was tracked by a global positioning system measuring distance travelled, position and speed. Comparing the total fluid intake of the soldier (12930 mL) to the rest of the participants (mean intake of 9 038 mL) up to 40 km, it is evident that his intake was 3892 mL (approximately 300 mL h(-1)) more than the mean for group. At approximately 17h14 the soldier was found lying by himself at the side of the route, 2.24 km from the finish point. He passed away the next day in a medical care facility. This tragic event provides the valuable opportunity to present data on the pacing, temperature regulation and fluid consumption of an exceptional athlete during the development of a fatal case of combined EAHE and EHS. Pacing, fluid intake, Tc and environmental condition data are presented for 5 km intervals throughout the march. We propose a novel hypothesis on the possible contribution of EAHE to the development of EHS.

Practical aspects of volume control in chronic kidney disease using whole body bioimpedance.

Abstract: Background: Fluid status is an independent predictor of mortality in dialysis patients. Current methods of fluid assessment have several limitations. Summary: An ideal method should be cheap, portable, easy to perform without extensive training, reproducible and determines patients' excess or deficit of total body water. Bioimpedance analysis (BIA) fulfils many of these criteria and can give additional information on fat and lean tissue composition. The accuracy and precision of BIA has been shown to be equivalent to the ‘gold standard' direct estimation techniques. Key Messages: Although there remains some concern about its validity in dialysis patients, fluid overload determined by BIA has been shown to predict mortality. BIA-guided fluid management appears superior to conventional fluid management in achieving clinically important outcomes such as reduction in blood pressure, left ventricular mass index, and arterial stiffness. Accurate setting of dry weight might also help preserve residual renal function by limiting episodes of dehydration. Nevertheless, as with all new technologies, there are issues that still need to be resolved. This will be achieved only with larger prospective interventional studies to explore its specific roles in dialysis cohorts.

Leptin and energy restriction induced adaptation in energy expenditure

Abstract: Background Diet-induced weight loss is accompanied by adaptive thermogenesis, i.e. a disproportional reduction of resting energy expenditure (REE) a decrease in physical activity and increased movement economy. Objective To determine if energy restriction induced adaptive thermogenesis and adaptations in physical activity are related to changes in leptin concentrations. Methods Eighty-two healthy subjects (23 men, 59 women), mean±SD age 41±8years and BMI 31.9±3.0kg/m 2 , followed a very low energy diet for 8weeks with measurements before and after the diet. Leptin concentrations were determined from fasting blood plasma. Body composition was assessed with a three-compartment model based on body weight, total body water (deuterium dilution) and body volume (BodPod). REE was measured (REEm) with a ventilated hood and predicted (REEp) from measured body composition. Adaptive thermogenesis was calculated as REEm/REEp. Parameters for the amount of physical activity were total energy expenditure expressed as a multiple of REEm (PAL), activity-induced energy expenditure divided by body weight (AEE/kg) and activity counts measured by a tri-axial accelerometer. Movement economy was calculated as AEE/kg (MJ/kg/d) divided by activity counts (Mcounts/d). Results Subjects lost on average 10.7±4.1% body weight (P 2 =0.06; P 2 =0.07; P Conclusion During energy restriction, the decrease in leptin explains part of the variation in adaptive thermogenesis. Changes in leptin are not related to the amount of physical activity but could partly explain the increased movement economy.

Creatine Supplementation Increases Total Body Water in Soccer Players: a Deuterium Oxide Dilution Study

Abstract: This study aimed to evaluate changes in total body water (TBW) in soccer athletes using a deuterium oxide dilution method and bioelectrical impedance (BIA) formulas after 7 days of creatine supplementation. In a double-blind controlled manner, 13 healthy (under-20) soccer players were divided randomly in 2 supplementation groups: Placebo (Pla, n=6) and creatine supplementation (CR, n=7). Before and after the supplementation period (0.3 g/kg/d during 7 days), TBW was determined by deuterium oxide dilution and BIA methods. 7 days of creatine supplementation lead to a large increase in TBW (2.3±1.0 L) determined by deuterium oxide dilution, and a small but significant increase in total body weight (1.0±0.4 kg) in Cr group compared to Pla. The Pla group did not experience any significant changes in TBW or body weight. Although 5 of 6 BIA equations were sensitive to determine TBW changes induced by creatine supplementation, the Kushner et al. 16 method presented the best concordance levels when compared to deuterium dilution method. In conclusion, 7-days of creatine supplementation increased TBW determined by deuterium oxide dilution or BIA formulas. BIA can be useful to determine TBW changes promoted by creatine supplementation in soccer athletes, with special concern for formula choice.

Effect of Nordic Walking and Water Aerobics Training on Body Composition and the Blood Flow in Lower Extremities in Elderly Women

Abstract: Nordic walking and water aerobics are very popular forms of physical activity in the elderly population The aim of the study was to evaluate the influence of regular health training on the venous blood flow in lower extremities and body composition in women over 50 years old Twenty-four women of mean age 579 (± 343) years, randomly divided into three groups (Nordic walking, water aerobics, and non-training), participated in the study The training lasted 8 weeks, with one-hour sessions twice a week Dietary habits were not changed Before and after training vein refilling time and the function of the venous pump of the lower extremities were measured by photoplethysmography Body composition was determined by bioelectrical impedance Eight weeks of Nordic walking training improved the venous blood flow in lower extremities and normalized body composition in the direction of reducing chronic venous disorder risk factors The average values of the refilling time variable (p = 004, p = 002, respectively) decreased in both the right and the left leg After training a statistically significant increase in the venous pump function index was found only in the right leg (p = 004) A significant increase in fat-free mass, body cell mass and total body water was observed (p = 001), whereas body mass, the body mass index, and body fat decreased (p < 003) With regard to water aerobic training, no similar changes in the functions of the venous system or body composition were observed

Ultraendurance cycling in a hot environment: thirst, fluid consumption, and water balance.

Abstract: The purpose of this field investigation was to identify and clarify factors that may be used by strength and conditioning professionals to help athletes drink adequately but not excessively during endurance exercise. A universal method to accomplish this goal does not exist because the components of water balance (i.e., sweat rate, fluid consumed) are different for each athlete and endurance events differ greatly. Twenty-six male cyclists (mean ± SD; age, 41 ± 8 years; height, 177 ± 7 cm; body mass, 81.85 ± 8.95 kg) completed a summer 164-km road cycling event in 7.0 ± 2.1 hours (range, 4.5-10.4 hours). Thirst ratings, fluid consumed, indices of hydration status, and body water balance (ingested fluid volume - [urine excreted + sweat loss]) were the primary outcome variables. Measurements were taken before the event, at designated aid stations on the course (52, 97, and 136 km), and at the finish line. Body water balance during exercise was not significantly correlated with exercise time on the course, height, body mass, or body mass index. Thirst ratings were not significantly correlated with any variable. We also observed a wide range of total sweat losses (4.9-12.7 L) and total fluid intakes (2.1-10.5 L) during this ultraendurance event. Therefore, we recommend that strength and conditioning professionals develop an individualized drinking plan for each athlete, by calculating sweat rate (milliliter per hour) on the basis of body mass change (in kilograms), during field simulations of competition.

Skeletal muscle water and electrolytes following prolonged dehydrating exercise.

Abstract: We studied if dehydrating exercise would reduce muscle water (H2Omuscle ) and affect muscle electrolyte concentrations. Vastus lateralis muscle biopsies were collected prior, immediately after, and 1 and 4 h after prolonged dehydrating exercise (150 min at 33 ± 1 °C, 25% ± 2% humidity) on nine endurance-trained cyclists (VO2max = 54.4 ± 1.05 mL/kg/min). Plasma volume (PV) changes and fluid shifts between compartments (Cl(-) method) were measured. Exercise dehydrated subjects 4.7% ± 0.3% of body mass by losing 2.75 ± 0.15 L of water and reducing PV 18.4% ± 1% below pre-exercise values (P < 0.05). Right after exercise H2Omuscle remained at pre-exercise values (i.e., 398 ± 6 mL/100 g dw muscle(-1)) but declined 13% ± 2% (342 ± 12 mL/100 g dw muscle(-1); P < 0.05) after 1 h of supine rest. At that time, PV recovered toward pre-exercise levels. The Cl(-) method corroborated the shift of fluid between extracellular and intracellular compartments. After 4 h of recovery, PV returned to pre-exercise values; however, H2Omuscle remained reduced at the same level. Muscle Na(+) and K(+) increased (P < 0.05) in response to the H2Omuscle reductions. Our findings suggest that active skeletal muscle does not show a net loss of H2O during prolonged dehydrating exercise. However, during the first hour of recovery H2Omuscle decreases seemly to restore PV and thus cardiovascular stability.

Hydration Status over 24-H Is Not Affected by Ingested Beverage Composition

Abstract: Objective: To investigate the 24-h hydration status of healthy, free-living, adult males when given various combinations of different beverage types.Methods: Thirty-four healthy adult males participated in a randomized, repeated-measures design in which they consumed: water only (treatment A), water+cola (treatment B), water+diet cola (treatment C), or water+cola+diet cola+orange juice (treatment D) over a sedentary 24-h period across four weeks of testing. Volumes of fluid were split evenly between beverages within each treatment, and when accounting for food moisture content and metabolic water production, total fluid intake from all sources was equal to 35 ± 1 ml/kg body mass. Urine was collected over the 24-h intervention period and analyzed for osmolality (Uosm), volume (Uvol) and specific gravity (USG). Serum osmolality (Sosm) and total body water (TBW) via bioelectrical impedance were measured after the 24-h intervention.Results: 24-h hydration status was not different between treatments A, B, C, a...

Effective body water and body mass changes during summer ultra-endurance road cycling

Abstract: Because body mass change (ΔMb) does not represent all water losses and gains, the present field investigation determined if (a) ΔMb equalled the net effective body water change during ultra-endurance exercise and (b) ground speed and exercise duration influenced these variables. Thirty-two male cyclists (age range, 35–52 years) completed a 164-km event in a hot environment, were retrospectively triplet matched and placed into one of three groups based on exercise duration (4.8, 6.3, 9.6 h). Net effective body water loss was computed from measurements (body mass, total fluid intake and urine excreted) and calculations (water evolved and mass loss due to substrate oxidation, solid food mass and sweat loss), including (ΔEBWgly) and excluding (ΔEBW) water bound to glycogen. With all cyclists combined, the mean ΔMb (i.e. loss) was greater than that of ΔEBWgly by 1200 ± 200 g (P = 1.4 × 10–18), was similar to ΔEBW (difference, 0 ± 200 g; P = .21) and was strongly correlated with both (R2 = .98). Analysi...

Comparison of Appetite-regulating Hormones and Body Composition in Pediatric Patients in Predialysis Stage of Chronic Kidney Disease and Healthy Control Group.

Abstract: Background: Protein-energy malnutrition (PEM) is a common complication in pediatric patients with chronic kidney disease (CKD). Components incorporated in the regulation of appetite and body composition appear to be of the focus in renal insufficiency and may influence the CKD-associated PEM. The purpose of this study was to investigate plasma levels of appetite-regulating hormones and their correlation with the body composition variables in a pediatric in predialysis stage of CKD. Methods: Thirty children with CKD in predialysis stage were selected and compared with 30 healthy sex- and age-matched controls. Blood samples were collected in fasting. Serum total ghrelin, leptin, and obestatin levels were measured using enzyme immunometric assay methods. Anthropometric parameters measurement and body composition analysis were done using the bioelectric impedance analysis (BIA) method. Results: Patients showed insignificant elevated total ghrelin (105.40±30.83 ng/l), leptin (5.32±1.17 ng/ml) and obestatin (5.07±1.09 ng/ml) levels in comparison with healthy participants. By using BIA, patients had significantly different Dry Lean Weight (P=0.048), Extra Cellular Water (P=0.045), Body Cell Mass (BCM) (P=0.021), Basal Metabolic Rate (P=0.033) and Body Mass Index (P=0.029) compared with controls. Furthermore, the total body water was slightly and the ECW was significantly higher in CKD participants. There were significant negative correlation between obestatin and BCM (r=-0.40, P=0.03) and fat free mass index (FFMI) (r=-0.40, P=0.029) in patients. Conclusion: It seems that our results are insufficient to clarify the role of appetite-regulating hormones in PEM in CKD patients. It is apparent that there are still many unknown parameters related to both appetite regulating and CKD-associated PEM.

Higher body fat and lower fat-free mass in girls with premature adrenarche

Abstract: OBJECTIVE Idiopathic premature adrenarche (PA) refers to presence of androgenic signs before the age of eight years in girls in the absence of thelarche. In children with PA, increased adrenal androgens lead to changes in body composition and transient growth acceleration. Although the association between PA and some components of the metabolic syndrome is well known, body composition has not been extensively studied in these patients. METHODS We examined 47 girls with PA with a median age of 7.39 years and 57 healthy controls with a median age of 7.11 years. For PA group, the inclusion criteria were appearance of pubic/axillary hair before 8 years of age, absence of findings of central puberty and absence of use of any medication. Patients with steroidogenic enzyme defects and virilizing tumors were excluded. Height, body weight, waist and hip circumference were measured. The bioelectrical impedance method was used for body composition analysis. RESULTS In the PA group, both body weight standard deviation score (SDS) and height SDS were significantly higher than in the controls (p<0.001 for both). While total body fat percentage values were significantly higher in the PA group than in the controls (median 22.8% vs. 19.95%, p=0.049), fat-free mass (FFM) and total muscle mass percentages were significantly lower than in the controls (median 76.8% vs. 79.9%, p=0.024 and 72.6% vs. 75.7%, p=0.018, respectively). CONCLUSION Our findings revealed that girls with PA have higher body weight and height for age values. They also show significant changes in body composition such as an increase in total body fat percentage with a concomitant decrease in the percentages of FFM, muscle mass and total body water.