High sodium intake and fluid overhydration predict cardiac structural and functional impairments in chronic kidney disease.

Background: High sodium intake and fluid overhydration are common factors of and strongly associated with adverse outcomes in chronic kidney disease (CKD) patients. Yet, their effects on cardiac dysfunction remain unclear. Aims: The study aimed to explore the impact of salt and volume overload on cardiac alterations in non-dialysis CKD. Methods: In all, 409 patients with CKD stages 1-4 (G1-G4) were enrolled. Daily salt intake (DSI) was estimated by 24-h urinary sodium excretion. Volume status was evaluated by the ratio of extracellular water (ECW) to total body water (TBW) measured by body composition monitor. Recruited patients were categorized into four groups according to DSI (6 g/day) and median ECW/TBW (0.439). Echocardiographic and body composition parameters and clinical indicators were compared. Associations between echocardiographic findings and basic characteristics were performed by Spearman's correlations. Univariate and multivariate binary logistic regression analysis were used to determine the associations between DSI and ECW/TBW in the study groups and the incidence of left ventricular hypertrophy (LVH) and elevated left ventricular filling pressure (ELVFP). In addition, the subgroup effects of DSI and ECW/TBW on cardiac abnormalities were estimated using Cox regression. Results: Of the enrolled patients with CKD, the median urinary protein was 0.94 (0.28-3.14) g/d and estimated glomerular filtration rate (eGFR) was 92.05 (IQR: 64.52-110.99) mL/min/1.73 m2. The distributions of CKD stages G1-G4 in the four groups was significantly different (p = 0.020). Furthermore, compared to group 1 (low DSI and low ECW/TBW), group 4 (high DSI and high ECW/TBW) showed a 2.396-fold (95%CI: 1.171-4.902; p = 0.017) excess risk of LVH and/or ELVFP incidence after adjusting for important CKD and cardiovascular disease risk factors. Moreover, combined with eGFR, DSI and ECW/TBW could identify patients with higher cardiac dysfunction risk estimates with an AUC of 0.704 (sensitivity: 75.2%, specificity: 61.0%). The specificity increased to 85.7% in those with nephrotic proteinuria (AUC = 0.713). The magnitude of these associations was consistent across subgroups analyses. Conclusion: The combination of high DSI (>6 g/d) and high ECW/TBW (>0.439) independently predicted a greater risk of LVH or ELVFP incidence in non-dialysis CKD patients. Moreover, the inclusion of eGFR and proteinuria improved the risk stratification ability of DSI and ECW/TBW in cardiac impairments in CKD.

Varicose vein treatment reduces edema not only in the treated legs but also in the entire body.

OBJECTIVES: We explored the connection between varicose vein and edema, by investigating extracellular water ratio (E/T) using bioelectrical impedance analysis. METHODS: In a prospective cohort study 120 patients underwent varicose vein surgery with extracellular fluid to total body water ratio (E/T) and E/T postop divided by E/Tpreop (E/T ratio) measured using a body composition analyzer. Edema was defined as E/T ≥0.390. Seventy-nine patients received unilateral treatment, while 41 underwent bilateral. p < .05 is statistically significant. RESULTS: Preoperatively, patients exhibited edema (E/T) in the treated leg (0.394 ± 0.009), untreated leg (0.392 ± 0.009), trunk (0.390 ± 0.007), and whole body (0.391 ± 0.007). Postoperatively, E/T decreased across body (p < .05). The lowest E/T ratio was observed in the treated leg (0.991 ± 0.012), followed by the untreated leg (0.994 ± 0.012), the trunk (0.995 ± 0.009), and the whole body (0.994 ± 0.009). E/T ratio of bilateral group were lower than unilateral group (p < .05). CONCLUSION: Varicose vein contributes to generalized edema, and treatment alleviates edema in the treated leg and the entire body.

Effect of Fluid Intake on Acute Changes in Plasma Volume: A Randomized Controlled Crossover Pilot Trial.

Plasma volume (PV) undergoes constant and dynamic changes, leading to a large intra-day variability in healthy individuals. Hydration is known to induce PV changes; however, the response to the intake of osmotically different fluids is still not fully understood. In a randomized controlled crossover trial, 18 healthy individuals (10 females) orally received an individual amount of an isotonic sodium-chloride (ISO), Ringer (RIN), or glucose (GLU) solution. Hemoglobin mass (Hbmass) was determined with the optimized carbon monoxide re-breathing method. Fluid-induced changes in PV were subsequently calculated based on capillary hemoglobin concentration ([Hb]) and hematocrit (Hct) before and then every 10 minutes until 120 min (t0-120) after the fluid intake and compared to a control trial arm (CON), where no fluid was administered. Within GLU and CON trial arms, no statistically significant differences from baseline until t120 were found (p > 0.05). In the ISO trial arm, PV was significantly increased at t70 (+138 mL, p = 0.01), t80 (+191 mL, p < 0.01), and t110 (+182 mL, p = 0.01) when compared to t0. Moreover, PV in the ISO trial arm was significantly higher at t70 (p = 0.02), t110 (p = 0.04), and t120 (p = 0.01) when compared to the same time points in the CON trial arm. Within the RIN trial arm, PV was significantly higher between t70 and t90 (+183 mL, p = 0.01) and between t110 (+194 mL, p = 0.03) and t120 (+186 mL, p < 0.01) when compared to t0. These results demonstrated that fluids with a higher content of osmotically active particles lead to acute hemodilution, which is associated with a decrease in [Hb] and Hct. These findings underpin the importance of the hydration state on PV and especially on PV constituent levels in healthy individuals.

High-standard predictive equations for estimating body composition using bioelectrical impedance analysis: a systematic review.

The appropriate use of predictive equations in estimating body composition through bioelectrical impedance analysis (BIA) depends on the device used and the subject's age, geographical ancestry, healthy status, physical activity level and sex. However, the presence of many isolated predictive equations in the literature makes the correct choice challenging, since the user may not distinguish its appropriateness. Therefore, the present systematic review aimed to classify each predictive equation in accordance with the independent parameters used. Sixty-four studies published between 1988 and 2023 were identified through a systematic search of international electronic databases. We included studies providing predictive equations derived from criterion methods, such as multi-compartment models for fat, fat-free and lean soft mass, dilution techniques for total-body water and extracellular water, total-body potassium for body cell mass, and magnetic resonance imaging or computerized tomography for skeletal muscle mass. The studies were excluded if non-criterion methods were employed or if the developed predictive equations involved mixed populations without specific codes or variables in the regression model. A total of 106 predictive equations were retrieved; 86 predictive equations were based on foot-to-hand and 20 on segmental technology, with no equations used the hand-to-hand and leg-to-leg. Classifying the subject's characteristics, 19 were for underaged, 26 for adults, 19 for athletes, 26 for elderly and 16 for individuals with diseases, encompassing both sexes. Practitioners now have an updated list of predictive equations for assessing body composition using BIA. Researchers are encouraged to generate novel predictive equations for scenarios not covered by the current literature.Registration code in PROSPERO: CRD42023467894.

Influence of aging on extracellular water-to-total body water ratio in community-dwelling females.

BACKGROUND & AIMS: The European Working Group of Sarcopenia in Older People 2 has emphasized the significance of evaluating not only muscle mass but also muscle quality as a diagnostic criterion for sarcopenia. The extracellular water-to-total body water ratio (ECW/TBW), measured using bioelectrical impedance analysis (BIA), has recently received attention as an indicator of muscle quality. However, the influence of aging on the ECW/TBW remains unclear. If ECW/TBW increases with age, it is important to know whether the timing of the decrease in SMI and the increase in ECW/TBW are the same or different. This study aimed to investigate the influence of aging on ECW/TBW in community-dwelling females. METHODS: This cross-sectional study included 237 community-dwelling females aged 20-89 years who could perform activities of daily living independently. ECW/TBW and SMI were measured using BIA. Multiple linear regression analyses of ECW/TBW and SMI were conducted. Age, body mass index (BMI), number of medications, pain, and medical history were considered independent variables in the multiple linear regression. The participants were divided into three (20-39, 40-64, and 65-89 years) or four (20-39, 40-64, 65-74, and 75-89 years) groups based on age. Analysis of covariance adjusted for the BMI, number of medications, pain, and medical history was conducted to determine the differences in ECW/TBW and SMI among the three or four groups. RESULTS: In the multiple linear regression analysis, age was significantly and independently associated with ECW/TBW and SMI. When the participants were divided into three groups based on age, an increase in ECW/TBW and a decrease in SMI in the 65-89-year group were confirmed compared with the 20-39 and 40-64-year groups. When the participants were divided into four groups based on age, an increase in ECW/TBW in the 75-89-year group was confirmed compared with the 65-74-year group. However, there were no significant differences in SMI among the four groups. CONCLUSIONS: This study revealed that ECW/TBW increases with aging in community-dwelling females. Moreover, the negative influences of aging were confirmed earlier in ECW/TBW than in SMI. Assessing muscle mass alone may not be adequate to capture the influences of aging on muscle composition, and evaluating ECW/TBW may be crucial for diagnosing sarcopenia.

Comparison of the Watson formula and bioimpedance spectroscopy for measuring body volume and calculating kt/V in patients with peritoneal dialysis.

CONCLUSION: There were significant differences between Vwat and Vbis and between Kt/Vwat and Kt/Vbis. Kt/Vwat may underestimate small-solute dialysis adequacy in most cases. Kt/Vbis instead of Kt/Vwat could be accounted for in creating individualized dialysis prescriptions if the patient has no obvious clinical symptoms.

Fluids and body composition during anesthesia in children and adolescents: A pilot study.

The purpose of this study is to evaluate the intracellular and extracellular volume before and after anesthesia in order to ascertain their variations and determine the potential utility of this information in optimizing intraoperative fluid administration practices. A bioimpedance spectroscopy device (body composition monitor, BCM) was used to measure total body fluid volume, extracellular volume, and intracellular volume. BCM measurements were performed before and after general anesthesia in unselected healthy children and adolescents visiting the Pediatric Institute of Southern Switzerland for low-risk surgical procedures hydrated with an isotonic solution. In 100 children and adolescents aged 7.0 (4.8-11) years (median and interquartile range), the average total body water increased perioperatively with a delta value of 182 (0-383) mL/m2 from pre- to postoperatively, as well as the extracellular water content, which had a similar increase with a delta value of 169 (19-307) mL/m2. The changes in total body water and extracellular water content significantly correlated with the amount of fluids administered. The intracellular water content did not significantly change.   Conclusion: Intraoperative administration of isotonic solutions results in a significant fluid accumulation in low-risk schoolchildren during general anesthesia. The results suggest that children without major health problems undergoing short procedures do not need any perioperative intravenous fluid therapy, because they are allowed to take clear fluids up to 1 h prior anesthesia. In future studies, the use of BCM measurements has the potential to be valuable in guiding intraoperative fluid therapy. What is Known: • Most children who undergo common surgical interventions or investigations requiring anesthesia are nowadays hydrated at a rate of 1700 mL/m2/day with an isotonic solution. • The use bioimpedance spectroscopy for the assessment of fluid status in healthy children has already been successfully validated. • The bioimpedance spectroscopy is already currently widely used in various nephrological settings to calculate fluid overload and determine patient's optimal fluid status. What is New: • Routine intraoperative fluid administration results in a significant fluid accumulation during general anesthesia in low-risk surgical procedures. • This observation might be relevant for children and adolescents with conditions predisposing to fluid retention. • In future studies, the use of BCM measurements has the potential to be valuable in guiding intraoperative fluid therapy.

Can non-invasive cardiac hemodynamics and fluid content system (NICaS) parameters predict Acute Heart Failure outcomes in Caucasian and Asian patients in the emergency department?

PURPOSE: Acute heart failure (AHF) is a serious condition that requires prompt diagnosis and management. To optimize patient care, clinicians need a reliable, non-invasive method to assess hemodynamic parameters and total body congestion. Currently, no standardized technology is widely used for this purpose. However, NICaS technology, which measures hemodynamic parameters based on regional bioimpedance, has shown promise in monitoring AHF patients in a non-invasive and reliable manner. In this study, researchers aimed to evaluate the usefulness of NICaS technology in predicting patients' outcome in Caucasian and Asian AHF patients presenting to the emergency department (ED). PATIENTS AND METHODS: The study included 40 Caucasian patients from Italy (group A) and 71 Asian patients from Indonesia and Singapore (group B) with a diagnosis of AHF in the ED. The study compared data from NICaS parameters, clinical findings, laboratory, and radiological results with short-term events. RESULTS: In group A, NICaS data at ED arrival significantly predicted 30-day cardiovascular mortality and rehospitalization. At discharge, a value of cardiac output obtained using NICaS was a significant predictor for 30-day rehospitalization. In group B, NICaS variables, total peripheral resistance index on admission and during 48-72 â€‹h had prominent AUC compared to clinical congestion score and NT-proBNP in predicting mortality and rehospitalization. CONCLUSIONS: The results indicate that NICaS technology offers a simple, non-invasive, and reliable method of assessing cardiac hemodynamics and congestion in AHF patients. These measurements may enhance diagnosis, tailor management plans, stratify risk, and predict outcomes in both Caucasian and Asian patients.

The effect of pre-exercise oral hyperhydration on endurance exercise performance, heart rate, and thermoregulation: a meta-analytical review.

This study aimed to determine the effect of pre-exercise hyperhydration on endurance performance (primary outcome), heart rate, thermoregulation, and perceptual responses (secondary outcomes). Six academic databases were searched to February 2023. Only studies reporting differences in hydration between intervention and placebo/control were included. Meta-analysis determined overall effect size (Hedges' g), and meta-regression the influence of independent moderators (ambient temperature, hyperhydration agent, exercise mode, extent of hyperhydration). Overall, 10 publications generating 19 effect estimates for primary outcomes, and 11 publications reporting 48 effect estimates for secondary outcomes, were included. A small-to-moderate improvement in time-to-exhaustion (TTE) (Hedges' g = 0.31, 95% CI: 0.13-0.50, p = 0.001) and time trial (TT) (g = 0.25, 95% CI: 0.002-0.51, p = 0.049) but not total work (TW) tasks (p = 0.120) was found following hyperhydration. No moderating effects were observed. No effect of hyperhydration was found for heart rate following steady state (SS) exercise (p = 0.069) or the performance task (p = 0.072), nor for body temperature post-SS (p = 0.132) or post-performance task (p = 0.349), but meta-regression of sodium versus glycerol showed lower body temperature post-performance task with sodium (g = 0.80, t (5) = 2.65, p = 0.046). No effects were found for perceived exertion or thermal comfort. Study heterogeneity was low, lacking representation of elite and female athletes, and weight-bearing (i.e., running) exercise modalities. These results suggest pre-exercise hyperhydration provides a small-to-moderate benefit to endurance performance in TTE and TT, but not TW performance tasks. While no moderating effects were observed, lack of heterogeneity makes it difficult to generalise these findings.

Association between ICW/TBW ratio and cancer prognosis: Subanalysis of a population-based retrospective multicenter study.

BACKGROUND & AIMS: Disease burden is known to alter cellular integrity and water balance. Therefore, the intracellular water/total body water (ICW/TBW) ratio is used as an adjunctive indicator to predict disease severity and prognosis. The ICW/TBW ratio of patients with cancer, who typically present with low muscle mass, poor nutritional status, and high inflammatory response, reportedly differs from that of the healthy population. Herein, we aimed to evaluate the effect of the ICW/TBW ratio on the prognosis of different subgroups of patients with cancer. METHODS: This multicenter cohort study included 2787 patients with malignancies between June 2014 and December 2018. The association between covariates and overall survival (OS) was assessed using restricted cubic spline models. The multivariate Cox regression model included variables demonstrating a statistical significance in the univariate Cox regression analysis (P < 0.05) without multicollinearity. The generated nomogram used the C-index and calibration curves to validate the predictive accuracy of the scoring system. RESULTS: The optimal cut-off value for the ICW/TBW ratio was 0.61. The ICW/TBW ratio was an independent prognostic factor (hazard ratio [HR]: 0.621; 95 % confidence interval [CI]: 0.537-0.719, P < 0.001). Moreover, the ICW/TBW ratio had a greater impact on the prognosis of patients receiving chemoradiotherapy than on those receiving chemotherapy alone (chemoradiotherapy: HR = 0.495, P = 0.005 vs. chemotherapy: HR = 0.646, P < 0.001). Multivariate Cox regression analysis showed that sex, age, tumor stage, body mass index, neutrophil-to-lymphocyte ratio (NLR), and ICW/TBW ratio were associated with OS. Subsequently, a nomogram was developed incorporating these variables and yielded a C-index of 0.743. CONCLUSIONS: The ICW/TBW ratio was associated with muscle mass, nutritional status, and inflammation. A low ICW/TBW ratio is an independent risk factor for poor prognosis in patients with cancer, especially when they are female, have advanced cancer stage, have sarcopenia, and are receiving radiotherapy.

Decreased Intracellular to Total Body Water Ratio and Depressive Symptoms in Patients with Maintenance Hemodialysis.

Objective: Depression is a common psychiatric disorder and related to poor outcomes in patients undergoing maintenance hemodialysis (MHD). Previous studies have reported some associations between sarcopenia and depressive symptoms. Recently, intracellular water (ICW) and total body water (TBW) have been found to reflect muscle function and muscle mass. ICW/TBW ratio is a marker of sarcopenia that is simple to assess. However, the relationship between ICW/TBW ratio and depression has not been explored in MHD patients. Methods: In our cross-sectional and multi-center study, 3300 adult MHD patients were included from June 1, 2021, to August 30, 2021. Depressive symptoms were evaluated using the Beck Depression Inventory-II (BDI-II). TBW and ICW were measured by Body Composition Monitor (BCM). Multivariable logistic regression, stratified analyses, and interactive analyses were conducted to assess the relationship between ICW/TBW ratio and depression. Results: About 16.5% of the 3300 MHD patients were found to have depressive symptoms. The prevalence of depression increased with decreasing quartiles of ICW/TBW ratios, and decreased ICW/TBW ratio was independently associated with depression after adjusting for potential confounders. Patients in Quartile 1 of ICW/TBW ratios were more likely to have depressive symptoms (odds ratio 1.55, 95% confidence interval 1.07-2.22; p=0.002) than those in Quartile 4. History of diabetes and education status had interactive roles in the relationship between depression and ICW/TBW ratios (p < 0.05). The association of ICW/TBW ratios and depression existed in patients of both genders and different education levels, but only in non-diabetic patients. Conclusion: In MHD patients, the decreased ratio of ICW/TBW was independently related to high depression rates.

Diabetes mellitus, malnutrition, and sarcopenia: The bond is not explained by bioelectrical impedance analysis in older adults.

As people age, their risk of diabetes mellitus (DM) and sarcopenia increases due to the decline in muscle mass and strength. Bioelectrical impedance analysis (BIA) is a method used to detect changes in body composition. The primary aim of the study was to determine the distribution of BIA variables among a group of non-DM people and two groups of patients with controlled and uncontrolled DM. The secondary aim was to establish the independent association between BIA-derived data, lipidic assets, and the prevalence of metabolic syndromes with DM. This study included a total of 235 participants who were categorized into three groups based on the presence of diabetes mellitus (DM) and their glycated hemoglobin (HbA1c) levels: non-DM, controlled DM (HbA1c≤7.0%), and uncontrolled DM (HbA1c>7.0%). Waist circumference (p=0.005), bone (p<0.001), muscular (p<0.001), and appendicular skeletal mass (p<0.001) were lower in the non-DM group, while sarcopenic risk (p<0.001), total cholesterol (p<0.001), and LDL (p<0.001), were higher. Grip strength (p<0.001), visceral fat (p=0.01), and phase angle (p=0.04) were significantly lower in non-DM than uncontrolled DM patients, as well as the number of drugs taken (p=0.014). A multivariate analysis highlighted that LDL (coefficient -0.006, p=0.01) was negatively associated, while bone mass (coefficient 0.498, p=0.0042) was positively associated with DM uncontrol. Our study shows that BIA may not be the ideal tool for distinguishing between elderly individuals with and without DM, as it can be affected by numerous covariates, including potential differences in glucometabolic and cardiovascular control.

Drinking recommended daily water significantly alters haemato-biochemical parameters in prospective blood donors; a one-center quasi-experimental study in a tropical setting.

BACKGROUND: In sub-Saharan Africa, the prevailing high ambient temperatures should warrant increased daily water intake (DWI) to prevent haemo-concentration and its potential to confound patients' laboratory data. AIM: To assess the impact that the recommended DWI has on the haemato-biochemical variables in a tropical setting. MATERIALS AND METHODS: This quasi-experimental study recruited 101 apparently healthy individuals (18-60 years) in the Bawku municipality. DWI, anthropometrics, and haemato-biochemical variables were assessed at baseline. Participants were encouraged to increase their DWI to ≥4 L over a 30-day period; haemato-biochemical variables were re-evaluated. Total body water (TBW) was anthropometrically estimated. RESULTS: The median post-treatment DWI significantly increased; consequently, anaemia cases increased by >20-fold (2.0 % vs 47.5 % post-treatment). RBC count, platelet count, WBC count, and median haemoglobin significantly decreased compared to baseline (p < 0.0001). Biochemically, median plasma osmolality (p < 0.0001), serum sodium (p < 0.0001), serum potassium (p = 0.0012) and random blood sugar (p = 0.0403) significantly decreased. Compared to baseline, significantly higher proportion of participants classified as thrombocytopenic (8.9 % vs 3.0 %), hyponatraemia (10.9 % vs 2.0 %), or normal osmolarity (77.2 % vs 20.8 %). There were differential bivariate correlations between pre- and post-treatment haemato-biochemical variables. CONCLUSION: Sub-optimal DWI is a likely confounder in haemato-biochemical data interpretation in the tropics.

Macadamia nut effects on cardiometabolic risk factors: a randomised trial.

We sought to examine the effects of daily consumption of macadamia nuts on body weight and composition, plasma lipids and glycaemic parameters in a free-living environment in overweight and obese adults at elevated cardiometabolic risk. Utilising a randomised cross-over design, thirty-five adults with abdominal obesity consumed their usual diet plus macadamia nuts (~15 % of daily calories) for 8 weeks (intervention) and their usual diet without nuts for 8 weeks (control), with a 2-week washout. Body composition was determined by bioelectrical impedance; dietary intake was assessed with 24-h dietary recalls. Consumption of macadamia nuts led to increased total fat and MUFA intake while SFA intake was unaltered. With mixed model regression analysis, no significant changes in mean weight, BMI, waist circumference, percent body fat or glycaemic parameters, and non-significant reductions in plasma total cholesterol of 2⋅1 % (-4⋅3 mg/dl; 95 % CI -14⋅8, 6⋅1) and low-density lipoprotein (LDL-C) of 4 % (-4⋅7 mg/dl; 95 % CI -14⋅3, 4⋅8) were observed. Cholesterol-lowering effects were modified by adiposity: greater lipid lowering occurred in those with overweight v. obesity, and in those with less than the median percent body fat. Daily consumption of macadamia nuts does not lead to gains in weight or body fat under free-living conditions in overweight or obese adults; non-significant cholesterol lowering occurred without altering saturated fat intake of similar magnitude to cholesterol lowering seen with other nuts. Clinical Trial Registry Number and Website: NCT03801837 https://clinicaltrials.gov/ct2/show/NCT03801837?term = macadamia + nut&draw = 2&rank = 1.

The Usefulness of Bioelectrical Impedance as a Marker of Fluid Status in Patients With Congestive Heart Failure: A Systematic Review and Meta-Analysis.

Bioelectrical impedance analysis (BIA) is a method that measures electrical currents conducted through water, which assesses fluid status by measuring extracellular water (ECW), total body water (TBW), and resistance (R). Limited studies are done to evaluate the utility of BIA in patients with congestive heart failure (CHF), and therefore, we performed a systematic review and meta-analysis to evaluate this. A comprehensive literature search was performed at Medline and Embase until March 2022. Our primary outcome was a comparison of TBW and ECW between patients with CHF and controls. Our secondary outcome was to compare R between the groups. All analysis was conducted using RevMan 5.4 software. Six studies with 1,046 patients met our inclusion criteria. Out of 1,046 patients, 526 had CHF and 538 had no CHF. Among patients with CHF, all 526 had decompensated CHF. There was no significant difference in TBW between patients with heart failure and the control group (mean deviation (MD) = 1.42 (-0.44-3.27), percent of variation (I2) = 0%, p = 0.13). ECW was significantly higher with an assessment of BIA in heart failure patients compared to patients in the control group (MD = 1.62 (0.82-2.42), I2 = 0%, p < 0.0001). Resistance of extracellular fluid was significantly lower in the heart failure group (MD = -45.64 (-72.88--18.41), I2 = 83%, p = 0.001). Publication bias was deferred as the number of included studies was less than 10. BIA can be helpful in ambulatory and inpatient setting to identify patients' fluid status, which can improve outcomes. However, larger prospective studies are needed to further evaluate the usefulness of BIA in the CHF population.

Phase angle and extracellular water-to-total body water ratio estimated by bioelectrical impedance analysis are associated with levels of hemoglobin and hematocrit in patients with diabetes.

Background: Anemia is one of the common complications of diabetes and is associated with mortality. Phase angle (PhA), ratio of extracellular water to total body water (ECW/TBW) and skeletal muscle mass index (SMI) estimated by bioelectrical impedance analysis (BIA) have been used as prognostic indicators for various chronic diseases and frailty. We aimed to clarify the clinical significance of PhA, ECW/TBW and SMI for anemia in patients with diabetes. Materials and methods: The values of PhA, ECW/TBW and SMI were estimated by a portable BIA device and blood samples were collected in 371 Japanese patients with diabetes. The relationships of PhA, ECW/TBW and SMI with hemoglobin (Hgb) and hematocrit (Hct) were statistically evaluated. Results: In simple linear regression analysis, PhA and SMI were positively correlated with Hgb and Hct levels in total subjects, male subjects and female subjects. In contrast, ECW/TBW was negatively correlated with Hgb and Hct levels regardless of sex. Multivariate regression analysis showed that both PhA and ECW/TBW but not SMI independently contributed to Hgb and Hct levels after adjustment of clinical confounding factors in both males and females. Conclusions: PhA and ECW/TBW but not SMI were associated with levels of Hgb and Hct in patients with diabetes. Therefore, aberrant values of PhA and ECW/TBW suggest a risk of anemia in diabetic patients.

Body Composition Assessment in Adult Females with Anorexia Nervosa and Bulimia Nervosa-A Cross-Sectional Study Comparing Dual-Energy X-Ray Absorptiometry Scan and Isotopic Dilution of Deuterium.

BACKGROUND: Eating disorders (EDs) compromise individuals' nutritional status, affecting, among other organs and systems, bone health. OBJECTIVES: This study aimed to assess and compare bone mineral density (BMD) from DXA scan and deuterium (D2O) dilution of adult females with anorexia nervosa (AN) and bulimia nervosa (BN). METHODS: This was a cross-sectional study with 53 female participants (18-49 y) with a diagnosis of AN (n = 25) or BN (n = 28). DXA scan was performed to assess BMD, FM, and FFM, and D2O dilution was used to assess total body water (TBW), FM, and FFM. Interviews/questionnaires were used to assess symptoms, illness trajectory, and physical activity. t-test, chi-square test, Pearson's linear correlation, linear regressions, and Bland-Altman analyses were performed, with a significance level of 5%. RESULTS: TBW below the recommended level for adult females (≥ 45%) was more frequent in BN (60%) compared with AN (21%; P = 0.013). FM index (FMI) (soft tissue only) (t-test P = 0.06), and FFM index (FFMI) (t-test P = 0.08) agreed between DXA scan and D2O dilution. Only FFMI did not show systematic bias of proportion (ß: -0.2, P = 0.177). The diagnosis of BN, binge-eating episodes, and physical activity in AN were associated with the differences in the methods' results. FMI was positively associated with BMD in AN, and both FMI and FFMI were positively associated with BMD in BN. CONCLUSIONS: In adult females with EDs, DXA scan and D2O dilution achieved agreement for FMI and FFMI. Changes in FM and FFM are important in understanding the mechanisms behind bone loss in EDs. Protocols for body composition assessment in EDs can help to minimize the effect of the ED diagnosis, ED behaviors (that is, excessive exercise and purging behaviors), and weight on the accuracy of measurements.

Athletes with different habitual fluid intakes differ in hydration status but not in body water compartments.

Physiological differences have been reported between individuals who have habitual low (LOW) and high (HIGH) water intake (WI). The aims of this study were to explore body water compartments, hydration status, and fat-free mass (FFM) hydration of elite athletes exposed to different habitual WI. A total of 68 athletes (20.6 ± 5.3 years, 23 females) participated in this observational cross-sectional study. Total WI was assessed by seven-day food diaries and through WI, athletes were categorized as HIGH (n = 28, WI≥40.0 mL/kg/d) and LOW (n = 40, WI≤35.0 mL/kg/d). Total body water (TBW) and extracellular water (ECW) were determined by dilution techniques and intracellular water (ICW) as TBW-ECW. Hydration status was assessed by urine-specific gravity (USG) using a refractometer. Fat (FM) and FFM were assessed by dual-energy X-ray absorptiometry (DXA). The FFM hydration was calculated by TBW/FFM. The USG was statistically different between groups for females (LOW: 1.024 ± 0.003; HIGH: 1.015 ± 0.006; p = 0.005) and males (LOW: 1.024 ± 0.002; HIGH: 1.018 ± 0.005; p < 0.001). No differences between groups were detected in body water compartments and FFM hydration in both sexes (p > 0.05). Multiple regression showed that WI remains a predictor of USG regardless of FFM, age, and sex (ß = -0.0004, p < 0.01). We concluded that LOW athletes were classified as dehydrated through USG although their water compartments were not different from HIGH athletes. These results suggest that LOW athletes may expectedly maintain the body water compartments' homeostasis through endocrine mechanisms. Interventions should be taken to encourage athletes to have sufficient WI to maintain optimal hydration.

Transepidermal water loss and stratum corneum hydration in forearm versus hand palm.

BACKGROUND: Skin measurements of transepidermal water loss (TEWL) and stratum corneum hydration (SCH) reflect different aspects of skin physiology. Since epidermal water loss depends on epidermal-to-air water vapor gradients, a possible quantitative relationship between TEWL and SCH may exist. This investigation's purpose was to test the possible TEWL-SCH relationship. MATERIALS AND METHODS: SCH and TEWL were measured noninvasively on forearm and palmer thenar eminence (hand) in 40 young adults (20 males) along with total body fat percentage (FAT) via bioimpedance. RESULTS: A significant positive nonlinear correlation (p < 0.001) was detected between SCH and TEWL in hands of the male cohort that occurred when SCH exceeded a threshold level. This threshold level was not exceeded in male or female forearms and forearms did not display a SCH-TEWL correlation. There was a weak inverse dependence of TEWL on FAT on both forearm and hand (p < 0.05), but no SCH-FAT relationship was observed. TEWL values on the forearm and hand were moderately correlated with each other (p = 0.002) but SCH values were not. CONCLUSION: The findings clarify the relationship between forearm and palmer hydration and TEWL values, and their relationship to total body fat percentages in young healthy adults. The significant correlation between palmer stratum corneum hydration and palmer TEWL that was discovered in the male but not the female cohort suggests a threshold hydration level for which TEWL depends both on skin barrier function and stratum corneum hydration. This implies that conditions with increased SCH may in part account for elevated TEWL values.

Calibration of Bioelectrical Impedance Analysis Against Deuterium Dilution for Body Composition Assessment in Stunted Ugandan Children.

BACKGROUND: BIA represents an important tool in body composition (BC) assessment, especially in low-income settings in which simple and affordable options are preferred. There is a particular need to measure BC in stunted children, in which cases population-specific BIA estimating equations are lacking. OBJECTIVES: We calibrated an equation to estimate body composition from BIA using deuterium dilution (2H) as the criterion method in stunted children. METHODS: We measured BC with 2H and performed BIA in stunted Ugandan children (n = 50). Multiple linear regression models were constructed to predict 2H-derived FFM from BIA-derived whole-body impedance and other relevant predictors. Model performance was expressed as adjusted R2 and RMSE. Prediction errors were also calculated. RESULTS: Participants were aged 16-59 mo, of whom 46% were girls, and their median (IQR) height-for-age z-score (HAZ) was -2.58 (-2.92 to -2.37) according to the WHO growth standards. Impedance index (height2/impedance measured at 50 kHz) alone explained 89.2% variation in FFM and had an RMSE of 583 g (precision error 6.5%). The final model contained age, sex, impedance index, and height-for-age z-score as predictors and explained 94.5% variation in FFM with an RMSE of 402 g (precision error 4.5%). CONCLUSIONS: We present a BIA calibration equation for a group of stunted children with a relatively low prediction error. This may help evaluate the efficacy of nutritional supplementation in large-scale trials in the same population. J Nutr 20XX;xxx:xx.