Bioelectrical Impedance Analysis Variables Research Articles

Prognostic value of bioelectrical impedance analysis in head and neck cancer patients undergoing radiotherapy: a VALOR® study.

Bioelectrical impedance analysis (BIA) serves as a method to estimate body composition. Parameters such as phase angle (PA), standardized phase angle (SPA), body mass cell (BCM), BCM index (BCMI), and fat-free mass (FFM) might significantly impact the prognosis of head and neck cancer (HNC) patients. The present study aimed to investigate whether bioelectrical parameters can be used to predict survival in the HNC population and establish the optimal cutoff points for predictive accuracy. A multicenter observational study was performed across 12 tertiary hospitals in Andalusia (a region from the south of Spain). A total of 494 patients diagnosed with HNC between 2020 and 2022 at different stages were included in this study, with a minimum follow-up period of 12 months. The BIA assessment was carried out during the first 2 weeks of radical radiotherapy treatment with chemotherapy or other systemic treatments. A multivariate logistic regression analysis of overall survival, complications, hospital admission, and palliative care and its relationship with BIA nutritional assessment was performed. Significant prognostic factors identified in the multivariable analysis encompassed phase angle (PA), standardized phase angle (SPA), body cell mass (BCM), and BCM index (BCMI). Lower PA and BCM values were significantly associated with adverse clinical outcomes. A BCM threshold above 17 kg/m2 was the most significant predictor for predicting survival within the overall HNC population. The PA values of <5.1° in male and <4.8° in female patients showed the best predictive potential for mortality. Increased PA (as a continuous variable) demonstrated a significantly reduced risk for mortality (OR, 0.64; 95% CI, 0.43-0.94; p < 0.05) and a decreased likelihood of hospital admission (OR, 0.75; 95% CI, 0.52-1.07; p < 0.05). Higher BCM correlated with a lower risk of mortality (OR, 0.88; 95% CI, 0.80-0.96; p < 0.01) and a diminished probability of hospital admission (OR, 0.91; 95% CI, 0.83-0.99; p < 0.05). BIA is a crucial tool in the nutritional assessment of HNC patients. BCM and PA are the main bioelectrical parameters used to predict clinical outcomes in this population. Future studies are needed to validate BIA variables in a large cohort to ensure whether early intensification of nutritional treatment would improve survival.

Effect of liraglutide on cardiometabolic profile and on bioelectrical impedance analysis in patients with obesity and metabolic syndrome

Metabolic syndrome (MetS) and obesity represent a public health problem worldwide. Bioelectrical impedance analysis (BIA) is a practical and effective way of evaluating body composition, especially abdominal fat. Liraglutide, a GLP-1 analog, reduces body weight and improves cardiometabolic parameters. In this prospective non-randomized intervention study, we evaluated the effect of 6 months of treatment with liraglutide (n = 57) on the clinical, laboratory and BIA findings of adult sex-stratified patients diagnosed with obesity and MetS, compared to a control group receiving sibutramine (n = 46). The groups were statistically similar with regard to the age of females (p = 0.852) and males (p = 0.657). Almost all anthropometric and BIA variables were higher in the treatment group than in the comparative group (p < 0.05). Abdominal circumference (AC) decreased significantly more in the treatment group. In males, body weight and fat mass also decreased (p < 0.05). Liraglutide treatment was associated with a greater reduction in trunk fat mass (FMT) (p < 0.05). AC and FMT were strongly correlated (rho = 0.531, p < 0.001) in the treatment group. In the multiple regression analysis, liraglutide treatment remained independently associated with FMT. Treatment with liraglutide for 6 months promoted weight loss, improved cardiometabolic and inflammatory parameters and led to a significant reduction in FMT correlated with AC in obese MetS patients of both sexes.

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.

Evaluation of raw segmental bioelectrical impedance variables throughout anterior cruciate ligament reconstruction rehabilitation

Background. Raw bioelectrical impedance analysis (BIA) variables are related to physical function in healthy and diseased populations. Therefore, BIA may be an insightful, noninvasive method of assessment to track following anterior cruciate ligament reconstruction (ACLR). Objectives. Evaluate phase angle, reactance and impedance at 50 kHz (PhA50, Xc50, and Z 50, respectively) in the operative (OP) and non-operative (NOP) limbs during ACLR rehabilitation. Approach. Seventeen patient (12 M, 5 F; 18.8 ± 4.8 years) clinic reports were evaluated prior to ACLR (PRE), two- (2 W), six- (6 W), and twelve-weeks (12 W) post-ACLR and at return to sport testing (RTS). Setting. All observations occurred during the participant’s physical therapy visits. Measurements. A multi-frequency BIA device measured segmental PhA, Xc, and Z. Linear mixed effects models were used to assess any leg and time interaction and changes over leg and time, independently. Any interactions or main effects were considered significant at p < 0.05. Main results. Significant leg x time interactions were observed for each variable. PhA50 and Xc50 of NOP were higher (p < 0.001) than OP at each time point by an average of by 0.9° and 4.9 Ω, respectively. In OP, PhA50 and Xc50 decreased from PRE to 2 W and increased from 6 to 12 W and 12 W to RTS (p < 0.01, for all). At RTS, PhA50 and Xc50 were similar to PRE in OP (p > 0.05). For Z 50, the OP leg did not change over time (p > 0.05). Z 50 was greater in NOP at 2 and 6 W (p < 0.01, for both). There were differences in PhA50 in NOP between PRE and 6 W and from 6 W to RTS (p < 0.05 for both). Xc50 did not change (p > 0.05), and Z 50 PRE was lower than at 2 W (p < 0.05). Significance. A multi-frequency BIA device can detect changes in segmental BIA variables following ACLR.

Influence of Upper-Extremity and Lower-Extremity Resistance Exercise on Segmental Body Composition and Body Fluid Estimates.

Rodriguez, C, Florez, CM, Prather, J, Zaragoza, J, Tinnin, M, Brennan, KL, Taylor, L, and Tinsley, GM. Influence of upper-extremity and lower-extremity resistance exercise on segmental body composition and body fluid estimates. J Strength Cond Res 37(5): 1042-1051, 2023-The purpose of this analysis was to determine if acute, localized resistance exercise (RE) artificially influences total and regional estimates of body composition from dual-energy X-ray absorptiometry (DXA) and bioelectrical impedance analysis (BIA). Recreationally active male ( n = 14) and female ( n = 18) subjects completed 3 testing visits: rest (R), upper-extremity RE (U), and lower-extremity RE (L). Dual-energy X-ray absorptiometry scans were completed before exercise and 60 minutes after exercise. Bioelectrical impedance analysis was completed immediately before and after exercise and at 15, 30, and 60 minutes after exercise. Subjects were not allowed to intake fluid during the exercise session or during the postexercise assessment period. The effects of the acute RE session on DXA and BIA estimates were analyzed using linear mixed-effects models with a random intercept for subject. Condition by time interactions were observed for most BIA outcomes. Relative to the reference model (i.e., R condition at baseline), total body water and fat-free mass estimates were, on average, approximately 1 and approximately 1.2 kg higher, in the U condition. In contrast, lower-extremity RE exerted little or no impact on most BIA variables. Some DXA estimates exhibited time main effects, but the magnitude of changes was negligible. An acute bout of localized RE, particularly upper-extremity RE, can artificially influence BIA body fluid and composition estimates, whereas DXA may be robust to the acute biological error introduced by RE. Although body composition assessments should ideally be conducted under standardized conditions, DXA may be suitable in less standardized situations. In addition, BIA is differentially influenced by upper-extremity and lower-extremity resistance exercise.

Bioelectrical impedance analysis to estimate one-repetition maximum measurement of muscle strength for leg press in healthy young adults

Resistance training (RT) progress is determined by an individual’s muscle strength, measured by one-repetition maximum (1RM). However, this evaluation is time-consuming and has some safety concerns. Bioelectrical impedance analysis (BIA) is a valid and easy-to-use method to assess skeletal muscle mass (SMM). Although BIA measurements are often correlated with muscle strength, few studies of 1RM for RT and BIA measurements are available. This observational study examined the relationship between 1RM and BIA measurements and developed BIA-based prediction models for 1RM. Thirty-five healthy young Japanese adults were included. SMM and the skeletal muscle mass index (SMI) were measured using the BIA device. In addition, dominant-leg 1RM was measured using a unilateral leg-press (LP) machine. The correlations between BIA measurements and 1RM were calculated, and simple regression analyses were performed to predict 1RM from the BIA variables. The results showed significant correlations between 1RM and dominant-leg SMM (R = 0.845, P = 0.0001) and SMI (R = 0.910, P = 0.0001). The prediction models for 1RM for LP derived from SMM of the dominant leg and SMI were Y = 8.21x + 8.77 (P = 0.0001), R2 = 0.73, and Y = 15.53x − 36.33 (P = 0.0001), R2 = 0.83, respectively. Our results indicated that BIA-based SMI might be used to predict 1RM for LP accurately.

Poor Nutritional Status and Dynapenia Are Highly Prevalent in Post-Acute COVID-19.

Poor nutritional status is common (estimated prevalence 5–69%) in acute coronavirus disease-2019 (COVID-19), and has been associated with hospitalization, the need for intensive care, and mortality. Body composition (BC) and muscle function have also been related in such patients to poor disease outcomes.As the evidence in the literature is limited, a cross-sectional study was carried out to determine the frequency of malnutrition in a cohort of post-acute COVID-19 patients referred to a rehabilitation center after hospital discharge. BC and muscle strength were assessed and the differences between bedridden and not bedridden patients were specifically evaluated.The study sample was composed of 144 post-acute COVID-19 patients (mean age 64.8 years; males = 95), 37% of whom were bedridden (males = 60%). Nutritional status was evaluated with Mini-Nutritional Assessment (MNA) and Controlling Nutritional status (CONUT). Fat-free mass (FFM) and skeletal muscle mass (SM) were estimated using bioelectrical impedance analysis (BIA). Raw BIA variables (phase angle = PhA and impedance ratios = IRs) were also determined and handgrip strength (HGS) was measured. Dynapenia was identified according to the 2019 EWGSOP criteria.According to MNA, 18% (n. 26) of patients were malnourished and 62% (n. 89) were at risk of malnutrition. As for CONUT, 21% (n. 31) of cases had moderate–severe malnutrition and 58% (n. 83) had light malnutrition. Abnormalities of raw BIA variables (low PhA and high IRs) and low HGS were more common in bedridden patients, in those who were malnourished, or had low FFM or SM. Dynapenic patients were 65% men and 47% women.In conclusion, malnutrition, BC alterations, and low HGS occur in post-acute COVID-19 patients and are more common in bedridden patients. Further studies are needed to identify reliable algorithms for assessing nutritional status in post-acute COVID-19 patients undergoing rehabilitation.

Segmental Bioimpedance Variables in Association With Mild Cognitive Impairment.

ObjectiveTo examine the changes in body composition, water compartment, and bioimpedance in mild cognitive impairment (MCI) individuals.MethodsWe obtained seven whole-body composition variables and seven pairs of segmental body composition, water compartment, and impedance variables for the upper and lower extremities from the segmental multi-frequency bioelectrical impedance analysis (BIA) of 939 elderly participants, including 673 cognitively normal (CN) people and 266 individuals with MCI. Participants’ characteristics, anthropometric information, and the selected BIA variables were described and statistically compared between the CN participants and those with MCI. The correlations between the selected BIA variables and neuropsychological tests such as the Korean version of the Mini-Mental State Examination and Seoul Neuropsychological Screening Battery – Second Edition were also examined before and after controlling for age and sex. Univariate and multivariate logistic regression analyses with estimated odds ratios (ORs) were conducted to investigate the associations between these BIA variables and MCI prevalence for different sexes.ResultsParticipants with MCI were slightly older, more depressive, and had significantly poorer cognitive abilities when compared with the CN individuals. The partial correlations between the selected BIA variables and neuropsychological tests upon controlling for age and sex were not greatly significant. However, after accounting for age, sex, and the significant comorbidities, segmental lean mass, water volume, resistance, and reactance in the lower extremities were positively associated with MCI, with ORs [95% confidence interval (CI)] of 1.33 (1.02–1.71), 1.33 (1.03–1.72), 0.76 (0.62–0.92), and 0.79 (0.67–0.93), respectively; with presumably a shift of water from the intracellular area to extracellular space. After stratifying by sex, resistance and reactance in lower extremities remained significant only in the women group.ConclusionAn increase in segmental water along with segmental lean mass and a decrease in body cell strength due to an abnormal cellular water distribution demonstrated by reductions in resistance and reactance are associated with MCI prevalence, which are more pronounced in the lower extremities and in women. These characteristic changes in BIA variables may be considered as an early sign of cognitive impairment in the elderly population.

The Effects of Fluid Hydration Status on Ultrasound Muscle Measurement in Hemodialysis Patients

This study aimed to explore the effects of fluid hydration status on ultrasound muscle measurement in hemodialysis (HD) patients. Ultrasound muscle examination of the right rectus femoris and bioelectrical impedance analysis measurement of the right lower limb were performed in HD patients at the periods of predialysis and postdialysis. The correlations between the changes in the corresponding ultrasound and bioelectrical impedance analysis variables were analyzed. A total of 50 patients on maintenance HD were included, with mean age of 52.6±13.5years. Patients were 40% female (n=20), and average dialysis duration was 2.62±2.42years. Compared to predialysis, the measurements of cross-sectional area, muscle thickness, echo intensity (EI), and their percentage changes all decreased significantly after the HD procedure (P<.05). The change in EI and its percentage change were significantly correlated with changes in total body water, intracellular water, and extracellular water (P<.05). The HD session may have significant effects on ultrasound muscle measurement. Both the indicators of muscle quantity (cross-sectional area and muscle thickness) and quality (EI) significantly decreased after HD, which may contribute to the change in fluid hydration status and the change in fluid composition.

Body Composition and Bioelectrical-Impedance-Analysis-Derived Raw Variables in Pole Dancers.

Few data are available on the body composition of pole dancers. Bioelectrical impedance analysis (BIA) is a method that is used to estimate fat-free mass (FFM) and fat mass (FM), while raw BIA variables, such as the impedance ratio (IR) and phase angle (PhA), are markers of body cell mass and the ratio between extracellular and total body water. The aim of this study was to evaluate the body composition of pole dancers compared to controls, in particular, those raw BIA variables that are considered as markers of muscle composition. Forty female pole dancers and 59 controls participated in the study. BIA was performed on the whole body and upper and lower limbs, separately, at 5, 50, 100 and 250 kHz. The FFM, FFM index, FM and body fat percentage (BF%) were predicted. The bioelectrical impedance indexes IR and PhA were also considered. Pole dancers exhibited higher FFMI and BI indexes and lower BF%. PhA was greater and IRs were smaller in pole dancers than in controls for the whole body and upper limbs. Considering the training level, FFM, whole-body IR and PhA were higher in the professionals than non-professionals. Raw BIA variables significantly differed between the pole dancers and controls, suggesting a higher BCM; furthermore, practicing pole dancing was associated with a greater FFM and lower FM.

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.

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. 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). 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. 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.

Raw bioelectrical impedance analysis variables (phase angle and impedance ratio) are significant predictors of hand grip strength in adolescents and young adults

Musculoskeletal fitness and body composition are major components of health-related physical fitness that are expected to be linked to each other. The aim of this study was to explore the association of musculoskeletal fitness (expressed as hand grip strength [HGS]) and raw bioelectrical impedance analysis (BIA) variables and other predictors in the second and third decades of life.Four groups of healthy normal-weight and overweight participants were studied: 130 male adolescents (age 16.0 ± 1.1 y), 143 female adolescents (16.0 ± 0.9 y), 141 young men (25.5 ± 2.0 y), and 141 young women (25.2 ± 1.9 y). Raw BIA variables (impedance [Z] and phase angle [PhA]) for the whole body were measured at four frequencies (5, 50, 100, and 250 kHz), and HGS was measured in both upper limbs.HGS was higher in males than females and higher in young men than male adolescents. A fairly strong correlation emerged in both genders between HGS and raw BIA variables-that is, bioimpedance index (height2/Z), PhA, and impedance ratios (Z at high frequency/Z at low frequency). In multiple regression analysis, bioimpedance index, PhA, and impedance ratio were more effective predictors of HGS than BIA-derived estimates of body composition or anthropometric variables such as height, weight, and body mass index. In both genders, HGS was significantly higher in young adults than in adolescents for the same PhA or impedance ratio.This study provides some insight into the use of raw BIA variables and HGS in the first decades of life, suggesting a new approach for a reliable assessment of muscle quality in terms of both muscle structure and strength.

Bioimpedance vector analysis in stable chronic heart failure patients: Level of agreement between single and multiple frequency devices.

The accuracy of estimating body composition compartments is critical in the clinical setting. Currently, there are different bioelectrical impedance analysis (BIA) devices available for obtaining raw BIA parameters. The aim of this study was to determine the level of agreement between multiple frequency (MF)-BIA and single frequency (SF)-BIA devices in obtaining raw BIA measurements (resistance (R), reactance (Xc), and phase angle (PhA)), as well as the agreement on the classification of hydration status and body cell mass by the bioelectrical impedance vector analysis (BIVA) method. This cross-sectional study included 406 outpatients with stable chronic heart failure (HF). The raw BIA measurements at 50kHz obtained by tetrapolar MF-BIA (Bodystat QuadScan 4000) were compared with those obtained by tetrapolar SF-BIA (RJL Quantum X). In addition, the patients were classified by their hydration status and body cell mass according to the BIVA method. Strong and significant correlations were observed between the two methods in all raw BIA variables (r≥0.90). Lin's concordance correlation coefficient (CCC) values were almost perfect for R (CCC=0.99; 95% CI 0.997 to 0.998), moderate for Xc (CCC=0.93; 95% CI 0.92 to 0.94), and poor for PhA (CCC=0.88; 95% CI 0.85 to 0.90). The agreement obtained in the two classifications (quadrants and hydration status) was >0.81. MF-BIA and SF-BIA demonstrated good agreement for measurement of the R parameter; however, the Xc and PhA parameters must be used carefully due to the previously reported variability. Likewise, the agreement in all classifications by the BIVA method was almost perfect.

The Predictive Role of Raw Bioelectrical Impedance Variables in Disordered Eating Attitudes in Female Ballet Dance Students.

The present study used receiver operating characteristic (ROC) curve analysis to investigate the accuracy of body composition and raw bioelectrical impedance analysis (BIA) in correctly classifying disordered eating attitudes (DEA) in dance students. Participants were 81 female dancers assigned in two groups: beginner training (BT; age (mean ± SD) = 10.09 ± 1.2 years, n = 32) and advanced training (AT; age = 15.37 ± 2.1 years, n = 49). Fat mass (FM) was estimated by Slaughter’s equation and skeletal muscle with Poortman’s equation. Impedance (Z), resistance (R), reactance (Xc) and phase angle (PhA) were obtained through multifrequency BIA at a frequency of 50 kHz. Fat-free mass (FFM) was assessed using Sun’s equation. For evaluation of DEA, the Eating Attitudes Test-26 (EAT-26) questionnaire was performed. We defined an EAT-26 score ≥ 20 as positive for DEA. Comparisons between groups were performed by a one-way ANOVA test or Kruskall-Wallis test. Spearman’s rank correlation coefficients were performed to assess associations between variables. ROC curve analysis was utilized to test the accuracy of body composition and BIA variables in predicting DEA. In the BT group, Xc and PhA demonstrated high accuracy in predicting DEA with an area under the curve (AUC) of 0.976 (95% confidence interval (CI): 0.85–1.00) and 0.957 (95% CI: 0.82–0.99), respectively, (both p < 0.0001). FFM Sun had an AUC of 0.836 (95% CI: 0.66–0.94) (p < 0.0001) in the BT group and FFM Slaughter was 0.797 (95% CI: 0.66–0.90) (p < 0.001) in the AT group. Reactance and Phase angle were excellent and useful predictors of DEA in the BT group.

Skeletal Muscle Mass and Extracellular Water/Total Body Water Independently Predict Phase Angle Percentile in Young Men

Abstract Objectives Phase angle, derived from bioelectrical impedance analysis (BIA), is used to describe both cellular and overall health. Many of the variables measured using BIA vary based on the hydration status of the individual. The ratio between extracellular water/total body water is commonly measured in BIA, and can be used as a measure of individual hydration. This pilot study explores the relationship between individual hydration status and phase angle and other BIA measurements. Methods Male college students (n = 57) from Oklahoma State University-Stillwater were recruited through an email messaging campaign. The participants answered an online Qualtrics demographic survey; height (±0.1 cm), blood pressure, and weight were taken. The Seca Medical Body Composition Analyzer mBCA 514 was used to conduct the BIA. Variable mean, standard deviations, and frequencies were calculated using SPSS version 25. Pearson correlation analysis and regression analysis were conducted. Significance was set at &amp;lt;.05. Results Participants characteristics included: age (m = 21.7 ± 1.3 years), 54% BMI &amp;lt;25, 39% blood pressure &amp;lt;120/80, and 63% white/7% Native American. Mean % body fat was 20.28 ± 8.76, and skeletal muscle was 32.223 kg ± 4.432 and visceral fat was 2.01 liters ± 2.11.Phase angle percentile ranged from 1% to 99% (m = 62.0% ± 31.4) and extracellular water/total body water ratio (ECW/TBW) ranged from 35.7 to 41.6 (m = 39.32 ± 1.35). Phase angle percentile was positively correlated with skeletal muscle mass (r = 0.503, P = 0.000) and negatively correlated with ECW/TBW (r = −0.659, P = 0.000), but not with other BIA variables. These two variables significantly predicted phase angle percentile (r2 = 0.817, P = 0.000). The standardized β was −0.762 (P = 0.000) for ECW/TBW and 0.627 (P = 0.000) for skeletal muscle mass. Conclusions The association of ECW/TBW on phase angle percentile suggest further investigation of the impact of water on this indicator of health is warranted. An investigation with a method of modulating ECW/TBW would be a logical next step in understanding this relationship. Funding Sources Funding was provided by the Lew Wentz Foundation, and the Nutritional Sciences Department at Oklahoma State University.

Bioelectrical impedance analysis (BIA) and physical fitness in nephropathic patients on peritoneal dialysis

Introduction: Body composition and physical fitness are both components of nutritional status and are closely related to each other. In clinical practice, they can be assessed using bioelectrical impedance analysis (BIA) and performing physical fitness tests (PF), respectively. The main objective of the study was to evaluate in patients in peritoneal dialysis (PD) the relationships of PF tests with those BIA variables that are considered as markers of skeletal muscle quality (qualitative BIA).

Raw Bioelectrical Impedance Analysis Variables Are Independent Predictors of Early All-Cause Mortality in Patients With COPD

Bioelectrical impedance analysis (BIA) is a valuable method for estimating fat-free mass and fat mass in patients with COPD by using specific predictive equations. In addition, raw BIA variables such as high- to low-frequency impedance ratios (IRs) and phase angle, most likely as a result of providing information on muscle quality, have been related to disease severity and mortality in patients with several diseases but never in COPD. The aim of this study was to investigate the predictive role of raw BIA variables on 2-year survival in COPD. Impedance (Z) at 5-10-50-100-250 kHz and phase angle at 50 kHz were determined in 210 patients with COPD. Three IRs were calculated: Z at 50 kHz/Z at 5 kHz (50/5 IR), Z at 100 kHz/Z at 5 kHz (100/5 IR), and Z at 250 kHz/Z at 5 kHz (250/5 IR). Demographic, respiratory, and body composition data at baseline were recorded. All-cause mortality was assessed during 2 years of follow-up. After the follow-up period, all-cause mortality was 13.8%. Statistically significant differences between nonsurvivors and survivors emerged in terms of age, weight, BMI, FEV1, inspiratory capacity, and modified Medical Research Council dyspnea score. With respect to nutritional variables, nonsurvivors had lower fat-free mass (P= .031), lower fat mass (P= .015), higher IRs (P< .001 for all the ratios), and lower phase angle (P< .001) compared with survivors. After adjustment for confounding factors, each unit increase of IRs and each unit decrease of phase angle were associated with a higher risk of death. IRs and phase angle, as raw BIA variables, are independent and powerful predictors of all-cause mortality in COPD and should be considered, together with inspiratory capacity and 6-min walk distance, as significant prognostic factors in the short- to middle-term.

Bioelectrical Impedance Analysis of Body Composition in Karate Athletes Regarding The Preparatory Period // Analiza telesnog sastava karatista bioelektričnom impedansom pre i posle pripremnog perioda

The aim of the paper was to asses changes in body composition using bioelectrical impedance analysis (BIA) methodology in members of national karate team after teen week preparatory training period. The investigation was carried out on 11 male karate contestants, aged 18 to 28 years mean age (21.82± 3.58). The body composition was analyzed with In Body 720. The BIA outcomes were divided in 3 group of variables: body fluid and body composition variables, obesity diagnose variables and segmental analysis variables. All BIA variables were insignificantly higher at second measuring (p&gt;005). Only Body mass index (BMI=24.1 vs 24.55); mineral (4.69 kg vs 4.77 kg) and osseous (3.85 kg vs 3.92 kg), were significantly higher (p≤0.05) after preparatory period. Body fat mass (BFM=10.34 kg vs 10.75 kg, p=0.329) and body fat percent (BF%= 12.73 vs13.22%) insignificantly increased after preparatory period. The skeletal mass has changed from 40.03kg to 40.55kg (p=0.276). Body composition analysis, changes in weight, BMI and body fluids are essential for weight categories dependent sports such as karate. Positive changes in body components and in body fluids suggest that the training process during the preparatory period did not show negative effects on body components and the hydration of the karate athletes.

Effect of Chia Seed (Salvia hispanica, L) Supplementation on Body Composition, Weight, Post‐prandial Glucose and Satiety

Research regarding the beneficial intake of chia seeds (high in α‐linolenic acid and dietary fiber) on body composition, weight, post‐prandial glucose levels (PPG) and satiety, in healthy female subjects is limited. Therefore, we sought to investigate the effects of adding 20% of daily calories from chia seeds on disease risk factors such as fat mass(FM), fat free mass(FFM), and body weight(BW), satiety, and PPG in healthy, free‐living females.College females (n=23) participated in a randomized, crossover design consisting of two five‐week diet treatment periods 1) chia seeds added (CHIA); 2) without chia seeds (CON), separated by a 5‐week washout. Body composition was measured with bioelectrical impedance analysis (BIA) and dual‐energy x‐ray absorptiometry (DXA). Fasting glucose and PPG were measured at baseline and 60min after chia consumption. Satiety was measured by visual analog scale (VAS) appetite questionnaires. IBM SPSS v22 analyzed PPG (MANOVA), satiety, FM, FFM, and BW, (one‐way ANOVA), and the VAS appetite questionnaires (independent t‐test).There was a significant main effect for time for BW (pre = 55.2 kg, post = 54.7kg), BF (pre = 29.9%, post = 29.2%), FM (pre = 16.5kg, post = 15.9kg), and FFM (pre = 36.6kg, post = 36.4kg), and no significance for treatment by time or for all BIA variables, before, during and after meal satiety; or VAS and PPG between the CHIA and CON treatments. Consuming chia as 20% of calories does not contribute to weight gain or body composition changes.Support or Funding InformationSalba Smart Natural Products, LLC

Bioelectrical impedance phase angle relates to function, disease severity and prognosis in stable chronic obstructive pulmonary disease

Bioelectrical impedance analysis (BIA) provides a simple method to assess changes in body composition. Raw BIA variables such as phase angle provide direct information on cellular mass and integrity, without the assumptions inherent in estimating body compartments, e.g. fat-free mass (FFM). Phase angle is a strong functional and prognostic marker in many disease states, but data in COPD are lacking. Our aims were to describe the measurement of phase angle in patients with stable COPD and determine the construct and discriminate validity of phase angle by assessing its relationship with established markers of function, disease severity and prognosis. 502 outpatients with stable COPD were studied. Phase angle and FFM by BIA, quadriceps strength (QMVC), 4-m gait speed (4MGS), 5 sit-to-stand time (5STS), incremental shuttle walk (ISW), and composite prognostic indices (ADO, iBODE) were measured. Patients were stratified into normal and low phase angle and FFM index. Phase angle correlated positively with FFM and functional outcomes (r = 0.35-0.66, p < 0.001) and negatively with prognostic indices (r = -0.35 to -0.48, p < 0.001). In regression models, phase angle was independently associated with ISW, ADO and iBODE whereas FFM was removed. One hundred and seventy patients (33.9% [95% CI, 29.9-38.1]) had a low phase angle. Phenotypic characteristics included lower QMVC, ISW, and 4MGS, higher 5STS, ADO and iBODE scores, and more exacerbations and hospital days in past year. The proportion of patients to have died was significantly higher in patients with low phase angle compared to those with normal phase angle (8.2% versus 3.6%, p = 0.02). Phase angle relates to markers of function, disease severity and prognosis in patients with COPD. As a directly measured variable, phase angle offers more useful information than fat-free mass indices.