Showing papers on "Body water published in 2021"

Adaptive physiological water conservation explains hypertension and muscle catabolism in experimental chronic renal failure

Abstract: Aim We have reported earlier that a high salt intake triggered an aestivation-like natriuretic-ureotelic body water conservation response that lowered muscle mass and increased blood pressure. Here, we tested the hypothesis that a similar adaptive water conservation response occurs in experimental chronic renal failure. Methods In four subsequent experiments in Sprague Dawley rats, we used surgical 5/6 renal mass reduction (5/6 Nx) to induce chronic renal failure. We studied solute and water excretion in 24-hour metabolic cage experiments, chronic blood pressure by radiotelemetry, chronic metabolic adjustment in liver and skeletal muscle by metabolomics and selected enzyme activity measurements, body Na+ , K+ and water by dry ashing, and acute transepidermal water loss in conjunction with skin blood flow and intra-arterial blood pressure. Results 5/6 Nx rats were polyuric, because their kidneys could not sufficiently concentrate the urine. Physiological adaptation to this renal water loss included mobilization of nitrogen and energy from muscle for organic osmolyte production, elevated norepinephrine and copeptin levels with reduced skin blood flow, which by means of compensation reduced their transepidermal water loss. This complex physiologic-metabolic adjustment across multiple organs allowed the rats to stabilize their body water content despite persisting renal water loss, albeit at the expense of hypertension and catabolic mobilization of muscle protein. Conclusion Physiological adaptation to body water loss, termed aestivation, is an evolutionary conserved survival strategy and an under-studied research area in medical physiology, which besides hypertension and muscle mass loss in chronic renal failure may explain many otherwise unexplainable phenomena in medicine.

Body Composition and Metabolic Assessment After Motor Complete Spinal Cord Injury: Development of a Clinically Relevant Equation to Estimate Body Fat

Abstract: Background: Obesity is at epidemic proportions in the population with spinal cord injury (SCI), and adipose tissue (AT) is the mediator of the metabolic syndrome. Obesity, however, has been poorly appreciated in SCI because of the lack of sensitivity that body mass index (BMI) conveys for obesity risk in SCI without measuring AT. Objectives: The specific objectives were to compare measures of body composition assessment for body fat with the criterion standard 4-compartment (4C) model in persons with SCI, to develop a regression equation that can be utilized in the clinical setting to estimate fat mass (FM), and to determine cardiometabolic risk using surrogates of obesity in a current model of metabolic syndrome. Methods: Seventy-two individuals with chronic (>1 year) motor complete (AIS A and B) C5-L2 SCI were recruited over 3 years. Subjects underwent assessment with 4C using hydrostatic (underwater) weighing (UWW), dual-energy x-ray absorptiometry (DXA), and total body water (TBW) assessment to determine percent body fat (%BF); fasting glucose and lipid profiles, and resting blood pressure were also obtained. BMI, DXA, bioelectrical impedance analyses (BIA), BodPod, circumferences, diameters, lengths, and nine-site skinfold (SF) were assessed and validated against 4C. A multiple linear regression model was used to fit %BF (dependent variable) using anthropometric and demographic data that had the greatest correlations with variables, followed by a combined forward/backward stepwise regression with Akaike information criterion (AIC) to identify the variables most predictive of the 4C %BF. To allow for a more practical model for use in the clinical setting, we further reduced the AIC model with minimal loss of predictability. Surrogate markers of obesity were employed with metabolic biomarkers of metabolic syndrome to determine prevalence in persons with SCI. Results: Subject characteristics included age 44.4 ± 11.3 years, time since injury (TSI) 14.4 ± 11.0 years, BMI 27.3 ± 5.9 kg/m2; 59 were men and 13 were women. Sitting waist circumference (WCSit ) was 95.5 ± 13.1 cm, supine waist circumference (WCSup) was 93.4 ± 12.7 cm, and abdominal skinfold (ABDSF) was 53.1 ± 19.6 mm. Findings showed 4C %BF 42.4 ± 8.6%, UWW %BF 37.3 ± 9.7%, DXA %BF 39.1 ± 9.4%, BodPod %BF 33.7 ± 11.4%, nine-site SF %BF 37.8 ± 9.3%, and BIA %BF 27.6 ± 8.6%. A regression equation using age, sex, weight, and ABDSF provided R2 correlation of 0.57 with 4C %BF (p < .0001). Metabolic syndrome was identified in 59.4% of the sample. Conclusion: Body composition techniques to determine body fat are labor intensive and expensive for persons with SCI, and the regression equation developed against the criterion standard 4C model may allow clinicians to quickly estimate %BF and more accurately demonstrate obesity-induced cardiometabolic syndrome in this population.

Body Composition Over the Menstrual and Oral Contraceptive Cycle in Trained Females.

Abstract: Purpose The influence of female sex hormones on body fluid regulation and metabolism homeostasis has been widely studied. However, it remains unclear whether hormone fluctuations throughout the menstrual cycle (MC) and with oral contraceptive (OC) use affect body composition (BC). Thus, the aim of this study was to investigate BC over the MC and OC cycle in well-trained females. Methods A total of 52 eumenorrheic and 33 monophasic OC-taking well-trained females participated in this study. Several BC variables were measured through bioelectrical impedance analysis 3 times in the eumenorrheic group (early follicular phase, late follicular phase, and midluteal phase) and on 2 occasions in the OC group (withdrawal phase and active pill phase). Results Mixed linear model tests reported no significant differences in the BC variables (body weight, body mass index, basal metabolism, fat mass, fat-free mass, and total body water) between the MC phases or between the OC phases (P > .05 for all comparisons). Trivial and small effect sizes were found for all BC variables when comparing the MC phases in eumenorrheic females, as well as for the OC cycle phases. Conclusions According to the results, sex hormone fluctuations throughout the menstrual and OC cycle do not influence BC variables measured by bioelectrical impedance in well-trained females. Therefore, it seems that bioimpedance analysis can be conducted at any moment of the cycle, both for eumenorrheic women and women using OC.

D3-creatine dilution for the noninvasive measurement of skeletal muscle mass in premature infants.

Abstract: BACKGROUND The rate of accrual of muscle mass in neonates has not been assessed. We describe the D3-creatine (D3Cr) dilution method, a noninvasive assessment of muscle mass in neonates. METHODS A total of 76 neonates >26-week-old corrected gestational age were enrolled and measured at 2-week intervals while admitted to a neonatal intensive care unit (NICU). Additional measures at 6 and 12-20 months after initial measurement were obtained if available. An enteral dose of 2 mg D3Cr in 0.5 mL 20% 2H2O was used to determine muscle mass and total body water (TBW). RESULTS Muscle mass by the D3Cr method was strongly associated with TBW and body weight (r = 0.9272, p < 0.0001 and r = 0.9435, p < 0.0001 for all time points and r = 0.6661, p < 0.0001 and r = 0.8634, p < 0.0001, respectively, while in the NICU). Change in muscle mass vs. change in body weight, TBW, and length were also strongly correlated. CONCLUSIONS The D3Cr dilution method provides a noninvasive assessment of muscle mass accrual in neonates, which has not been previously possible and may be an important new tool for the evaluation of nutritional status and normal growth patterns. IMPACT We describe a noninvasive method for the measurement of skeletal muscle mass neonates. At the present time, there is no direct measurement of muscle mass in infants available. The D3Cr dilution method is a direct and noninvasive measurement of muscle mass. Using a single enteral dose of D3Cr in 2H2O followed by urine and saliva samples, rapid and substantial accrual of muscle mass and TBW is assessed. Assessment of muscle mass accrual in premature infants may be a strong indicator of nutritional status. Change in muscle mass is strongly related to change in weight and TBW.

Regulation of plasma volume in male lowlanders during 4 days of exposure to hypobaric hypoxia equivalent to 3500 m altitude

Abstract: KEY POINTS Acclimatization to hypoxia leads to a reduction in plasma volume (PV) that restores arterial O2 content. Findings from studies investigating the mechanisms underlying this PV contraction have been controversial, possibly as experimental conditions were inadequately controlled. We examined the mechanisms underlying the PV contraction evoked by 4 days of exposure to hypobaric hypoxia (HH) in 11 healthy lowlanders, while strictly controlling water intake, diet, temperature and physical activity. Exposure to HH-induced an ∼10% PV contraction that was accompanied by a reduction in total circulating protein mass, whereas diuretic fluid loss and total body water remained unchanged. Our data support an oncotically driven fluid redistribution from the intra- to the extravascular space, rather than fluid loss, as the mechanism underlying HH-induced PV contraction. ABSTRACT Extended hypoxic exposure reduces plasma volume (PV). The mechanisms underlying this effect are controversial, possibly as previous studies have been confounded by inconsistent experimental conditions. Here, we investigated the effect of hypobaric hypoxia (HH) on PV in a cross-over study that strictly controlled for diet, water intake, physical activity and temperature. Eleven males completed two 4-day sojourns in a hypobaric chamber, one in normoxia (NX) and one in HH equivalent to 3500 m altitude. PV, urine output, volume-regulating hormones and plasma protein concentration were determined daily. Total body water (TBW) was determined at the end of both sojourns by deuterium dilution. Although PV was 8.1 ± 5.8% lower in HH than in NX after 24 h and remained ∼10% lower thereafter (all P 0.23). Plasma renin activity and circulating aldosterone were suppressed in HH during the first half of the sojourn (all P 0.05). Markers for atrial natriuretic peptide were higher in HH than NX after 30 min (P = 0.001) but lower during the last 2 days (P < 0.001). While plasma protein concentration was similar between sojourns, total circulating protein mass (TCP) was reduced in HH at the same time points as PV (all P < 0.03). Despite transient hormonal changes favouring increased diuresis, HH did not enhance urine output. Instead, the maintained TBW and reduced TCP support an oncotically driven fluid redistribution into the extravascular compartment as the mechanism underlying PV contraction.

Effects of Adolescents' Lifestyle Habits and Body Composition on Bone Mineral Density.

Abstract: The incidence of osteoporosis is increasing as the population ages, as is the need to manage and prevent it. Adolescence is the period when the fastest development of bone mass takes place. Increasing adolescents' maximum bone mass and avoiding the risk factors for its loss are effective for preventing osteoporosis. This study investigated the factors influencing adolescents' bone mineral density (BMD). The participants were 126 middle- and high-school students from Gangwon-do; 47.6% (n = 60) were male, with an average age of 15 (range 12-18) years of age. It was found that age, carbonated beverages, snacks, and calcium supplements were variables that showed significant differences in adolescents' BMD. Additionally, through correlation analysis, it was found that height, weight, body mass index (BMI), body water, protein, minerals, body fat mass, and skeletal muscle mass were correlated with BMD. Multiple regression analysis identified age, calcium supplements, BMI, body fat mass, and skeletal muscle mass as BMD-associated factors. These results show that adolescents' BMD is higher with lower body fat mass, higher BMI and skeletal muscle mass, and a higher intake of calcium supplements.

Does the Nutritional Composition of Dairy Milk Based Recovery Beverages Influence Post-exercise Gastrointestinal and Immune Status, and Subsequent Markers of Recovery Optimisation in Response to High Intensity Interval Exercise?

Abstract: This study aimed to determine the effects of flavored dairy milk based recovery beverages of different nutrition compositions on markers of gastrointestinal and immune status, and subsequent recovery optimisation markers. After completing 2 h high intensity interval running, participants (n = 9) consumed a whole food dairy milk recovery beverage (CM, 1.2 g/kg body mass (BM) carbohydrate and 0.4 g/kg BM protein) or a dairy milk based supplement beverage (MBSB, 2.2 g/kg BM carbohydrate and 0.8 g/kg BM protein) in a randomized crossover design. Venous blood samples, body mass, body water, and breath samples were collected, and gastrointestinal symptoms (GIS) were measured, pre- and post-exercise, and during recovery. Muscle biopsies were performed at 0 and 2 h of recovery. The following morning, participants returned to the laboratory to assess performance outcomes. In the recovery period, carbohydrate malabsorption (breath H2 peak: 49 vs. 24 ppm) occurred on MBSB compared to CM, with a trend toward greater gut discomfort. No difference in gastrointestinal integrity (i.e., I-FABP and sCD14) or immune response (i.e., circulating leukocyte trafficking, bacterially-stimulated neutrophil degranulation, and systemic inflammatory profile) markers were observed between CM and MBSB. Neither trial achieved a positive rate of muscle glycogen resynthesis [-25.8 (35.5) mmol/kg dw/h]. Both trials increased phosphorylation of intramuscular signaling proteins. Greater fluid retention (total body water: 86.9 vs. 81.9%) occurred on MBSB compared to CM. Performance outcomes did not differ between trials. The greater nutrient composition of MBSB induced greater gastrointestinal functional disturbance, did not prevent the post-exercise reduction in neutrophil function, and did not support greater overall acute recovery.

Body composition monitoring in children and adolescents: reproducibility and reference values.

Abstract: There is an increasing need for suitable tools to evaluate body composition in paediatrics. The Body Composition Monitor (BCM) shows promise as a method, but reference values in children are lacking. Twenty children were included and measured twice by 4 different raters to asses inter- and intra-rater reproducibility of the BCM. Reliability was assessed using the Bland-Altman method and by calculating intraclass correlation coefficients (ICCs). The intra-rater ICCs were high (≥ 0.97) for all parameters measured by BCM as were the inter-rater ICCs for all parameters (≥ 0.98) except for overhydration (0.76). Consequently, a study was set up in which BCM measurements were performed in 2058 healthy children aged 3–18.5 years. The age- and gender-specific percentile values and reference curves for body composition (BMI, waist circumference, fat mass and lean tissue mass) and fluid status (extracellular and intracellular water and total body water) relative to age were produced using the GAMLSS method for growth curves. Conclusion: A high reproducibility of BCM measurements was found for fat mass, lean tissue mass, extracellular water and total body water. Reference values for these BCM parameters were calculated in over 2000 children and adolescents aged 3 to 18 years.

Body Composition in Elite Soccer Players from Youth to Senior Squad.

Abstract: There is a strong relationship between body composition and performance in male soccer players. This study aimed to display an optimal body height and weight, and body composition profile of male soccer players for four competitive age groups. This cross-sectional study included four groups: U-15 (n = 152), U-17 (n = 154), U-19 (n = 61), and seniors (n = 27). Body height and weight were measured under standard conditions, and the bioelectrical impedance analyzer (BIA) analyzed body composition. On average, soccer players in the U-15 group had significantly lower body height, weight, body mass index, skeletal muscle mass, fat-free mass, total body water and basal metabolic rate than U-17, U-19 and seniors, but a higher percentage of body fat than U-17 and U-19, p < 0.05. In addition, the results show significant non-linear increases in body height, weight and body composition as the age of soccer players increases, with the exception of the percentage of body fat mass, which tends to significantly decrease with age. The main findings of this study are that body fat mass remains stable and similar across all age groups, including in the senior squad.

The influence of body position on bioelectrical impedance spectroscopy measurements in young children

Abstract: Bioelectrical impedance techniques are easy to use and portable tools for assessing body composition. While measurements vary according to standing vs supine position in adults, and fasting and bladder voiding have been proposed as additional important influences, these have not been assessed in young children. Therefore, the influence of position, fasting, and voiding on bioimpedance measurements was examined in children. Bioimpedance measurements (ImpediMed SFB7) were made in 50 children (3.38 years). Measurements were made when supine and twice when standing (immediately on standing and after four minutes). Impedance and body composition were compared between positions, and the effect of fasting and voiding was assessed. Impedance varied between positions, but body composition parameters other than fat mass (total body water, intra- and extra-cellular water, fat-free mass) differed by less than 5%. There were no differences according to time of last meal or void. Equations were developed to allow standing measurements of fat mass to be combined with supine measurements. In early childhood, it can be difficult to meet requirements for fasting, voiding, and lying supine prior to measurement. This study provides evidence to enable standing and supine bioimpedance measurements to be combined in cohorts of young children.

Interstitial washdown and vascular albumin refill during fluid infusion: novel kinetic analysis from three clinical trials.

Abstract: Increased capillary filtration may paradoxically accelerate vascular refill of both fluid and albumin from the interstitial space, which is claimed to be edema-preventing. We characterized this proposed mechanism, called “interstitial washdown”, by kinetic analyses of the hemodilution induced by intravenous infusion of crystalloid fluid during 3 distinct physiological states. Greater plasma dilution of hemoglobin as compared to albumin during fluid therapy indicated recruitment of albumin, which was compared to the flow of interstitial fluid to the plasma as indicated by population volume kinetic analysis. Data for the comparison were derived from 24 infusions of crystalloid fluid in conscious volunteers, 30 in anesthetized patients, and 31 in patients with ketoacidosis from hyperglycemia. “Interstitial washdown” increased the plasma albumin concentration by between 0.3 and 1.0 g/L in the three series of infusions. The initial albumin concentration in the interstitial fluid returning to the plasma was estimated to between 22 g/L and 29 g/L, which decreased to an average of 50–75% lower during the subsequent 2–3 h. Kinetic simulations show that pronounced washdown was associated with increased capillary filtration (high k12) and, in conscious subjects, with greater plasma and interstitial volume expansion and restricted urine flow. During anesthesia, the main effect was an increase in the non-exchangeable fluid volume (“third-spacing”). Crystalloid fluid accelerates lymphatic flow that moderately increases plasma albumin, but more clearly helps to maintain the intravascular volume. This “interstitial washdown” mechanism becomes exhausted after a few hours.

Bone mineral density in elite masters athletes: the effect of body composition and long-term exercise

Abstract: The purpose of the study was to examine how bone mineral density (BMD) is related to body composition depending on the practiced sport (endurance, speed-power, throwing sports) in participants of the World Masters Athletics Championship. Dual-energy X-ray absorptiometry (DXA) was used to determine BMD and bone mass (BMC). Body composition was analyzed by means of the JAWON Medical X-scan analyzer using bioelectrical impedance methods. Percentage body fat (%BF), body fat mass (BFM), lean body mass (LBM), total body water (TBW), soft lean mass (SLM), intracellular water (ICW), and extracellular water (ECW) were evaluated. Among men, the most important variables affecting the BMD norm were LBM (OR = 32.578; p = 0.023), ECW (OR = 0.003; p = 0.016) and ICW (OR = 0.011; p = 0.031), in the distal part and SLM (OR = 5.008; p = 0.020) and ICW (0.354, p = 0.008) in the proximal part. In women, the most important predictors of normal BMD were ICW (OR = 10.174; p = 0.003) and LBM (OR = 0.470; p = 0.020) in the distal part and ICW (OR = 5.254; p = 0.038) in the proximal part. The representatives of strength based events had the most advantageous BMD levels. The condition of bone tissue evaluated by BMC and BMD of the forearm in masters athletes was strongly determined by the level of lean body components and the type of sports training associated with the track and field event. In the most important predictors of the BMD norm were also hydration components ECW and ICW. However, this relationship requires more research on the nature and mechanisms of these interactions.

Comparison of Bioelectrical Impedance Analysis Parameters for the Detection of Fluid Overload in the Prediction of Mortality in Patients Admitted at the Emergency Department

Abstract: Background Fluid overload (FO) in critically ill patients is associated with increased adverse events. This study aims to compare different bioelectrical impedance analysis (BIA) parameters that demonstrate FO and their association with 30-day mortality in critical patients admitted to the emergency department (ED). Methods Five components of the BIA were obtained by multifrequency device-total body water (TBW), extracellular water (ECW), intracellular water (ICW), resistance (R), and reactance (Xc)-to calculate parameters (impedance vectors, impedance ratio, and the ratios of ECW to TBW, ECW to ICW, ECW to body surface area, TBW to height2 , ICW to height2 , Xc to height, and R to height) that have been used for the detection of FO. A concordance analysis (κ) was performed comparing every parameter with each other. Furthermore, different regression models (Cox regression) were created associating the FO for each parameter with 30-day mortality, adjusted for age, body mass index, sex, Sequential Organ Failure Assessment score, and serum albumin level. Results A total of 142 patients were included in the study. Only FO by impedance vector analysis (relative risk [RR] = 6.4; 95% CI, 1.5-27.9; P = .01), impedance ratio (RR = 2.7; 95% CI, 1.1-7.1; P = .04), and R (RR = 2.6; 95% CI, 1.2-5.5; P = .02) increased the probability of 30-day mortality. Conclusions Different parameters that determine FO by BIA were associated with the mortality of patients admitted to the ED, but the impedance vector analysis was superior to any other parameter of the BIA.

Higher ratio of extracellular water to total body water was associated with reduced cognitive function in type 2 diabetes.

Abstract: BACKGROUND Fluid imbalance is associated with various clinical conditions, but the association between elevated extracellular-water to total-body-water (ECW/TBW) ratio, an indicator of fluid balance, and cognitive impairment is unknown. We aimed to investigate relationship between ECW/TBW ratio and cognitive function in type 2 diabetes mellitus. METHODS This study was a cross-sectional design, comparing 1233 patients aged 61.4 ± 8.0 years from the Singapore Study of Macro-angiopathy and Micro-vascular Reactivity in Type 2 Diabetes (SMART2D) cohort. ECW/TBW was measured using bioelectrical impedance method. Cognitive function was assessed with Repeatable Battery for the Assessment of Neuropsychological Status (RBANS). Multiple linear regression was used to examine association between ECW/TBW and RBANS scores, adjusting for demographics, education, clinical covariates, and apolipoprotein E allele. RESULTS In unadjusted analyses, there was an inverse dose-dependent association between ECW/TBW and RBANS total score. The associations persisted in fully adjusted model with β = -1.18 (95% confidence interval [CI] -2.19 to -0.17; P = 0.022) for slight edema and -2.33 (-3.99 to -0.67; P = 0.006) for edema. Slight edema and edema were significantly associated with reduced cognitive function in delayed memory and attention. There was significant association between edema but not slight edema, with reduced cognitive function in language. Pulse pressure accounted for 16.8% of association between ECW/TBW and RBANS total score. CONCLUSIONS Our novel finding of an independent association between higher ECW/TBW and poorer cognitive function highlights the potential importance of maintaining body fluid balance in the management of cognitive impairment.

Quantitative assessment of sodium mass removal using ionic dialysance and sodium gradient as a proxy tool: Comparison of high-flux hemodialysis versus online hemodiafiltration.

Abstract: Restoration and maintenance of sodium are still a matter of concern and remains of critical importance to improve the outcomes in homeostasis of stage 5 chronic kidney disease patients on dialysis. Sodium mass balance and fluid volume control rely on the "dry weight" probing approach consisting mainly of adjusting the ultrafiltration volume and diet restrictions to patient needs. An additional component of sodium and fluid management relies on adjusting the dialysate-plasma sodium concentration gradient. Hypotonicity of ultrafiltrate in online hemodiafiltration (ol-HDF) might represent an additional risk factor in regard to sodium mass balance. A continuous blood-side approach for quantifying sodium mass balance in hemodialysis and ol-HDF using an online ionic dialysance sensor device ("Flux" method) embedded on hemodialysis machine was explored and compared to conventional cross-sectional "Inventory" methods using anthropometric measurement (Watson), multifrequency bioimpedance analysis (MF-BIA), or online clearance monitoring (OCM) to assess the total body water. An additional dialysate-side approach, consisting of the estimation of inlet/outlet sodium mass balance in the dialysate circuit was also performed. Ten stable hemodialysis patients were included in an "ABAB"-designed study comparing high-flux hemodialysis (hf-HD) and ol-HDF. Results are expressed using a patient-centered sign convention as follows: accumulation into the patient leads to a positive balance while recovery in the external environment (dialysate, machine) leads to a negative balance. In the blood-side approach, a slight difference in sodium mass transfer was observed between models with hf-HD (-222.6 [-585.1-61.3], -256.4 [-607.8-43.7], -258.9 [-609.8-41.3], and -258.5 [-607.8-43.5] mmol/session with Flux and Inventory models using VWatson , VMF-BIA , and VOCM values for the volumes of total body water, respectively; global P value < .0001) and ol-HDF modalities (-235.3 [-707.4-128.3], -264.9 [-595.5-50.8], -267.4 [-598.1-44.1], and -266.0 [-595.6-55.6] mmol/session with Flux and Inventory models using VWatson , VMF-BIA , and VOCM values for the volumes of total body water, respectively; global P value < .0001). Cumulative net ionic mass balance on a weekly basis remained virtually similar in hf-HD and ol-HDF using Flux method (P = n.s.). Finally, the comparative quantification of sodium mass balance using blood-side (Ionic Flux) and dialysate-side approaches reported clinically acceptable (a) agreement (with limits of agreement with 95% confidence intervals (CI): -166.2 to 207.2) and (b) correlation (Spearman's rho = 0.806; P < .0001). We validated a new method to quantify sodium mass balance based on ionic mass balance in dialysis patients using embedded ionic dialysance sensor combined with dialysate/plasma sodium concentrations. This method is accurate enough to support caregivers in managing sodium mass balance in dialysis patients. It offers a bridging solution to automated sodium proprietary balancing module of hemodialysis machine in the future.

Hospitalization for COVID-19 is associated with significant changes in body composition.

Abstract: Summary Background & aims COVID-19 is a severe viral infection of the respiratory tract and has become a worldwide pandemic. Months after the initial infection several people report persistent limitations in daily life. Previous studies have identified body composition as a predictor of clinical progression in cases of COVID-19. However, body impedance measurements were limited to baseline and not repeated in serial measurements. In this study we analyzed the impact of a moderate oxygen-dependent COVID-19 infection on body composition during hospitalization. Methods We enrolled 12 consecutive patients hospitalized due to an oxygen-dependent SARS-CoV-2 infection. Body impedance analysis was performed within 24 h of admission and repeated on day 3 ± 1 as well as on the day of discharge. Endpoints were any significant changes in body composition. Results Median age of enrolled patients was 70.6 years with a BMI of 30.8 kg/m2. Patients were hospitalized for 14 days. Median oxygen demand was 3 l/min, 2 patients required mechanical ventilation. Body water and fat remained unchanged during the study period. We observed a significant decrease of phase angle (−0.6, p Conclusion We found a significant reduction in body cell mass and phase angle during the active infection with slow regression towards hospital discharge. Future studies are needed to clarify if nutrition and training programs during and after COVID-19 might limit these changes and have a positive impact on clinical course and rehabilitation.

Metabolic syndrome and unfavorable outcomes on body composition and in visceral adiposities indexes among early breast cancer women post-chemotherapy.

Abstract: Summary Purpose The study objected to investigate potential changes in metabolic, dietary, and nutritional status in women with stages I-III breast cancer exposed to chemotherapy. Methods Women who were starting chemotherapy with no previous treatment were recruited. Anthropometrics, bioelectrical impedance analysis, handgrip strength, blood pressure and blood sample were collected. Visceral adiposity index and lipid accumulation product were calculated. Dietary intake was evaluated, and the multiple source methods program was applied. Metabolic syndrome (MetS) was assessed following the NCEP-ATP III criteria (defined as 3 of 5 components of MetS). All data were collected at 2-time points: diagnosis (T0) and after 1 month of completion of therapy (T1). Mean, standard deviation, percentage, and ANOVA in SAS Studio® were used to explore the results. Results 61 women were included. We did not find any changes in anthropometrics and body composition. However, phase angle, extracellular water (EX) and ratio EX to total body water had expressive changes (p Conclusion We have found supporting evidence for chemotherapy treatment resulting in worsening of nutritional markers, lipid profile and adiposity markers. After chemotherapy part of the sample developed MetS, even without changes in body weight, fat mass, and food intake. Breast cancer patients may benefit from targeted interventions before starting chemotherapy to prevent MetS post-treatment, and therefore reduce the risk of cardiovascular disease. Further investigation into this theme is needed.

Higher extracellular water to total body water ratio was associated with chronic kidney disease progression in type 2 diabetes

Abstract: Aim We studied the association between extracellular volume status and chronic kidney disease (CKD) progression; and the role of extracellular volume excess as a potential mediator in the relationship between matrix metalloproteinases (MMP)-2 and CKD progression in Type 2 diabetes mellitus (T2DM). Methods We conducted a prospective cohort study of 1079 T2DM patients. Bioelectrical impedance analysis (BIA) was performed to assess body fluid status. Results After up to 8.6 years of follow-up, 471 (43.7%) patients experienced CKD progression. In the fully adjusted model, extracellular water (ECW)/ total body water (TBW)ratios 0.39–0.40 and > 0.40 were associated with 45% and 78% higher risk of CKD progression respectively. Patients with an increase in ECW/TBW ratio had 40% higher risk of CKD progression compared to those with no change or reduction of ECW/TBW ratio. Higher ECW/TBW ratio accounted for 17.4% of the relationship between MMP-2 and CKD progression in T2DM (p = 0.026). Conclusions Extracellular volume excess was independently associated with CKD progression in T2DM. Higher ECW/TBW ratio mediated the positive association between MMP-2 and CKD progression. Further studies are needed to elucidate the role of extracellular volume excess in deterioration of renal function.

Bioelectrical Impedance Analysis for Evaluation of Body Composition: A Review

Abstract: Bioelectrical impedance (BIA) is a painless, non-invasive, and easily portable technique that may clarify how the human body is operational. Body composition (BC) assessment is commonly established as a clinical technique for evaluating and estimating disease status. BIA has been applied to assess the mass distribution and water compartments in the BC. BIA has several parameters: fat mass, fat-free mass, total body water, phase angle, and body mass index; these parameters show the body distributions. Thus, BIA could beneficially predict the patient’s status. However, more studies need to improve validity and reliability, according to these aspects. The purpose of this review was to briefly theoretical procedures of numerous compartments models of body composition.

The effect of additional protein on lean body mass preservation in post-bariatric surgery patients: a systematic review.

Abstract: As result of bariatric surgery, patients are susceptible to protein deficiency which can result in undesirable lean body mass (LBM) loss. Consumption of high-protein diets or supplements could counteract this, but evidence about the effect is scarce. This paper systematically reviewed the literature to determine the effect of additional protein intake (≥60 g/day) on LBM preservation in post-bariatric patients. An electronic search of PubMed, EMBASE and the Cochrane Library was conducted. Studies were included if patients received a high-protein diet or protein supplements for at least one month, and LBM was assessed. The primary outcome was difference in mean LBM loss between the experimental (protein) and control group. Secondary outcomes were differences in body fat mass, total body water, body mass index and resting metabolic rate. Two of the five included studies (n = 223) showed that consumption of proteins resulted in significant LBM preservation. Only one study reported a significant difference in the reduction of body fat mass and resting metabolic rate in favour of a high-protein diet, but none of the studies showed a significant difference in total body water loss or body mass index change between the two groups. This paper showed inconclusive evidence for LBM preservation due to protein supplementation or a high-protein diet in post-bariatric patients. This outcome might be subjected to certain limitations, including a lack of blinding and a low compliance rate reported in the included studies. More specific and personalized recommendations regarding protein intake may need to be established by high quality research. Studies investigating the quantity (g/day) and quality (whey, casein or soy) of proteins are also needed.

Extracellular water/total body water ratio as predictor of mortality in hemodialysis patients

Abstract: Overhydration is a predictor of mortality in hemodialysis (HD) patients. Bioimpedance spectroscopy (BIS) is used to determine the body composition. Extracellular Water/Total Body Water (ECW/TBW) ra...

Evaluation of the Relationships between Simple Anthropometric Measures and Bioelectrical Impedance Assessment Variables with Multivariate Linear Regression Models to Estimate Body Composition and Fat Distribution in Adults: Preliminary Results.

Abstract: Background: Overweight and obesity are conditions associated with sedentary lifestyle and accumulation of abdominal fat, determining increased mortality, favoring chronic diseases, and increasing cardiovascular risk. Although the evaluation of body composition and fat distribution are highly relevant, the high cost of the gold standard techniques limits their wide utilization. Therefore, the aim of this work was to explore the relationships between simple anthropometric measures and BIA variables using multivariate linear regression models to estimate body composition and fat distribution in adults. Methods: In this cross-sectional study, sixty-eight adult individuals (20 males and 48 females) were subjected to bioelectrical impedance analysis (BIA), anthropometric measurements (waist circumference (WC), neck circumference (NC), mid-arm circumference (MAC)), allowing the calculation of conicity index (C-index), fat mass/fat-free mass (FM/FFM) ratios, body mass index (BMI) and body shape index (ABSI). Statistical analyzes were performed with the R program. Nonparametric Statistical tests were applied to compare the characteristics of participants of the groups (normal weight, overweight and obese). For qualitative variables, the Fisher’s exact test was applied, and for quantitative variables, the paired Wilcoxon signed-rank test. To evaluate the linear association between each pair of variables, the Pearson correlation coefficient was calculated, and Multivariate linear regression models were adjusted using the stepwise variable selection method, with Akaike Information Criterion (p ≤ 0.05). Results: BIA variables with the highest correlations with anthropometric measures were total body water (TBW), body fat percentage (BFP), FM, FFM and FM/FFM. The multiple linear regression analysis showed, in general, that the same variables can be estimated through simple anthropometric measures. Conclusions: The assessment of fat distribution in the body is desirable for the diagnosis and definition of obesity severity. However, the high cost of the instruments (dual energy X-ray absorptiometry, hydrostatic weighing, air displacement plethysmography, computed tomography, magnetic resonance) to assess it, favors the use of BMI in the clinical practice. Nevertheless, BMI does not represent a real fat distribution and body fat percentage. This highlights the relevance of the findings of the current study, since simple anthropometric variables can be used to estimate important BIA variables that are related to fat distribution and body composition.

Prognostic value of bioelectrical impedance analysis for assessment of fluid overload in ICU patients: a pilot study.

Abstract: INTRODUCTION The non-invasive analysis of body fluid composition with bio-electrical impedance analysis (BIA) provides additional information allowing for more persona-lised therapy to improve outcomes. The aim of this study is to assess the prognostic value of fluid overload (FO) in the first week of intensive care unit (ICU) stay. MATERIAL AND METHODS A retrospective, observational analysis of 101 ICU patients. Whole-body BIA measurements were performed, and FO was defined as a 5% increase in volume excess from baseline body weight. RESULTS Baseline demographic data, including severity scores, were similar in both the fluid overload-positive (FO+, n = 49) patients and in patients without fluid overload (FO-, n = 52). Patients with FO+ had significantly higher cumulative fluid balance during their ICU stay compared to those without FO (8.8 ± 7.0 vs. 5.5 ± 5.4 litres; P = 0.009), VE (9.9 ± 6.5 vs. 1.5 ± 1.5 litres; P < 0.001), total body water (63.0 ± 9.5 vs. 52.8 ± 8.1%; P < 0.001), and extracellular water (27.0 ± 7.3 vs. 19.6 ± 3.7 litres; P < 0.001). The presence of 5%, 7.5%, and 10% fluid overload was directly associated with increased ICU mortality rates. The percentage fluid overload (P = 0.039) was an independent predictor for hospital mortality. CONCLUSIONS A higher mortality rate in ICU-patients with FO was observed. FO is an independent prognostic factor because neither APACHE-II, SOFA, nor SAPS-II significantly differed on admission between survivors and non-survivors. Further research is needed to confirm these data prospectively and to evaluate whether BIA-guided deresuscitation in the subacute phase will improve mortality rates.

Lean Body Mass and Muscle Cross-Sectional Area Adaptations Among College Age Males with Different Strength Levels across 11 Weeks of Block Periodized Programmed Resistance Training.

Abstract: The block periodization training paradigm has been shown to produce enhanced gains in strength and power. The purpose of this study is to assess resistance training induced alterations in lean body mass and cross-sectional area using a block periodization training model among individuals (n = 15) of three differing strength levels (high, moderate and low) based on one repetition maximum back squat relative to body weight. A 3 × 5 mixed-design ANOVA was used to examine within-and between-subject changes in cross-sectional area (CSA), lean body mass (LBM), lean body mass adjusted (LBMadjusted) and total body water (TBW) over an 11-week resistance training program. LBMadjusted is total body water subtracted from lean body mass. The ANOVA revealed no statistically significant between-group differences in any independent variable (p > 0.05). Within-group effects showed statistically significant increases in cross-sectional area (p < 0.001), lean body mass (p < 0.001), lean body mass adjusted (p ˂ 0.001) and total body water (p < 0.001) from baseline to post intervention: CSA: 32.7 cm2 ± 8.6; 36.3 cm2 ± 7.2, LBM: 68.0 kg ± 9.5; 70.6 kg ± 9.4, LBMadjusted: 20.4 kg ± 3.1; 21.0 kg ± 3.3 and TBW: 49.8 kg ± 6.9; 51.7 kg ± 6.9. In conclusion, the results of this study suggest subjects experienced an increase in both lean body mass and total body water, regardless of strength level, over the course of the 11-week block periodized program. Gains in lean body mass and cross-sectional area may be due to edema at the early onset of training.

In-Season Body Composition Effects in Professional Women Soccer Players

Abstract: This study aimed to analyze anthropometric and body composition effects in professional soccer women players across the early and mid-competitive 2019/20 season. Seventeen players (age, height, body mass, and body mass index of 22.7 ± 6.3 years, 167.5 ± 5.6 cm, 60.7 ± 6.6 kg and 21.6 ± 0.2 kg/m2) from a Portuguese BPI League team participated in this study. The participants completed ≥80% of 57 training sessions and 13 matches. They were assessed at three points (before the start of the season (A1), after two months (A2), and after four months (A3)) using the following variables: body fat mass (BFM), soft lean mass (SLM), fat-free mass (FFM), intracellular water (ICW), extracellular water (ECW), total body water (TBW), and phase angle (PhA, 50 Khz), through InBody S10. Nutritional intake was determined through a questionnaire. Repeated measures ANCOVA and effect sizes (ES) were used with p < 0.05. The main results occurred between A1 and A2 for BFM (-21.7%, ES = 1.58), SLM (3.7%, ES = 1.24), FFM (4%, ES = 1.34), ICW (4.2%, ES = 1.41), TBW (3.7%, ES = 1.04). Furthermore, there were significant results between A1 and A3 for FFM (4.8%, ES = 1.51), ICW (5%, ES = 1.68), and PhA (10.4%, ES = 6.64). The results showed that the water parameters improved over time, which led to healthy hydration statuses. The training load structure provided sufficient stimulus for appropriate physical fitness development, without causing negative disturbances in the water compartments.

Multicomponent density models for body composition: Review of the dual energy X-ray absorptiometry volume approach.

Abstract: Accurate and precise body composition estimates, notably of total body adiposity, are a vital component of in vivo physiology and metabolic studies. The reference against which other body composition approaches are usually validated or calibrated is the family of methods referred to as multicomponent "body density" models. These models quantify three to six components by combining measurements of body mass, body volume, total body water, and osseous mineral mass. Body mass is measured with calibrated scales, volume with underwater weighing or air-displacement plethysmography, total body water with isotope dilution, and osseous mineral mass by dual-energy X-ray absorptiometry. Body density is then calculated for use in model as body mass/volume. Studies over the past decade introduced a new approach to quantifying body volume that relies on dual-energy X-ray absorptiometry measurements, an advance that simplifies multicomponent density model development by eliminating the need for underwater weighing or air-displacement plethysmography systems when these technologies are unavailable and makes these methods more accessible to research and clinical programs. This review critically examines these new dual-energy X-ray approaches for quantifying body volume and density, explores their shortcomings, suggests alternative derivation approaches, and introduces ideas for potential future research studies.

Differences in heart rate variability and body composition in breast cancer survivors and women without cancer

Abstract: The aim of this study was to explore cardiac autonomic changes assessed by linear and nonlinear indexes of heart rate variability (HRV) and body composition modifications in breast cancer survivors and cancer-free control women. Women who were breast cancer survivors (BCS, n = 27) and without cancer with similar characteristics (Control, n = 31) were recruited for this study. We calculated some relevant linear and nonlinear parameters of 5 min of RR interval time series such as mean RR interval (RRave), the corrected Poincare index (cSD1/SD2), the sample entropy (SampEn), the long-term fractal scaling exponent (α2) and 2UV from symbolic dynamics. Additionally, we indirectly assessed body composition measures such as body weight, fat mass, visceral fat rating (VFR), normalized VRF (nVFR), muscle mass, metabolic age, and total body water. We found that diverse HRV indexes and only one body composition measure showed statistical differences (p < 0.05) between the BCS and Control groups. RRave: 729 (648–802) vs. 795 (713–852) ms; cSD2/SD1: 3.4 (2.7–5.0) vs. 2.9 (2.3–3.5); SampEn: 1.5 (1.3–1.8) vs. 1.7 (1.5–1.8); α2: 0.6 (0.3–0.6) vs. 0.5 (0.4–0.5); 2UV: 7.1 (4.3–11.5) vs. 10.8 (6.4–15.7) and nVFR 0.12 (0.11–0.13) vs. 0.10 (0.08–0.12) points/kg, respectively. The nVFR was strongly significantly correlated with several indexes of HRV only in the BCS group.Our findings suggest that BCS exhibit lower parasympathetic cardiac activity and changes in HRV patterns compared to Controls. A concomitant increase of visceral fat, among other factors, may contribute to cardiac autonomic disturbances and changes in HRV patterns in BCS.

The influence of fasting and carbohydrate-enriched drink administration on body water amount and distribution: a volunteer randomized study.

Abstract: Fasting prior to anesthesia is considered aspiration prophylaxis. However, prolonged food and drink restrictions may increase the risk of other complications. The aim of this study was to assess whether a carbohydrate-enriched drink (Nutricia™ preOp®), recommended by the enhanced recovery after surgery (ERAS) protocol, can improve body hydration in fasting healthy individuals. Measurements were done with the bioelectric impedance analysis with a Fresenius body composition monitor. Body composition, total body water, water distribution, and hemodynamic parameters were measured at the beginning of the study and after 10 h and 12 h of fasting. Patients fasted for 10 h and then were divided into two groups: the control (n = 40) and the pre-op group (n = 41). The pre-op group received 400 mL of Nutricia™ preOp®, as suggested in the ERAS guidance. The two-tailed Student’s t test was used to compare two groups with normally distributed data and homogenous variances; if variances were heterogeneous, Welch’s test was used. The Mann-Whitney U test was used to compare two groups with non-normal data distribution. p < 0.05 was considered statistically significant. We found no significant differences between the control and pre-op groups regarding body water distribution and body composition. We did not observe significant losses in the total body water after fasting. Also, blood pressure was not affected by fasting. We have proven that pre-op did not impact either body composition or body water. ClinicalTrials.gov , NCT04665349 . Registered on 11 December 2020—retrospectively registered.

Adiposity, reproductive and metabolic health, and activity levels in zoo Asian elephant (Elephas maximus).

Abstract: Many captive Asian elephant populations are not self-sustaining, possibly due in part to obesity-related health and reproductive issues. This study investigated relationships between estimated body composition and metabolic function, inflammatory markers, ovarian activity (females only) and physical activity levels in 44 Asian elephants (n=35 females, n=9 males). Deuterium dilution was used to measure total body water from which fat mass (FM) and fat-free mass (FFM) could be derived to estimate body composition. Serum was analyzed for progestagens and estradiol (females only), deuterium, glucose, insulin and amyloid A. Physical activity was assessed by an accelerometer placed on the elephant's front leg for at least 2 days. Relative fat mass (RFM) - the amount of fat relative to body mass - was calculated to take differences in body size between elephants into consideration. Body fat percentage ranged from 2.01% to 24.59%. Male elephants were heavier (P=0.043), with more FFM (P=0.049), but not FM (P>0.999), than females. For all elephants, estimated RFM (r=0.45, P=0.004) was positively correlated with insulin. Distance walked was negatively correlated with age (r=-0.46, P=0.007). When adjusted for FFM and age (P<0.001), non-cycling females had less fat compared with cycling females, such that for every 100 kg increase in FM, the odds of cycling were 3 times higher (P<0.001). More work is needed to determine what an unhealthy amount of fat is for elephants; however, our results suggest higher adiposity may contribute to metabolic perturbations.