Segmental Bioimpedance Analysis Research Articles

Association between appendicular skeletal muscle mass and myocardial glucose uptake measured by 18F-FDG PET.

Low muscle mass is associated with high insulin resistance and an increased risk of cardiovascular disease. This study aims to determine whether low muscle mass affects the alterations in myocardial substrate metabolism that are associated with the development of cardiovascular disease. The study included 299 individuals (182 men and 117 women) who underwent examination at the Severance Health Check-up Center between January 2018 and February 2019. Myocardial glucose uptake was assessed using [18F]-fluorodeoxyglucose-positron emission tomography (18F-FDG PET/CT) scanning. Direct segmental bioimpedance analysis was used to measure appendicular skeletal muscle mass (ASM). We analysed men and women separately owing to sex-related body composition differences. ASM/Ht2 was significantly positively correlated with myocardial glucose uptake measured by 18F-FDG PET/CT [ln (SUVheart/liver)] only in men (r=0.154, P=0.038 in men; r=-0.042, P=0.652 in women, respectively). In men, myocardial glucose uptake was significantly associated with ASM/Ht2 even after adjusting for multiple confounders in a multivariable linear regression model (standardized β=0.397, P=0.004, in men; β=-0.051, P=0.698, in women). In women, age (β=-0.424 P=0.029) was independent determinants of myocardial glucose uptake. In men, ASM was strongly associated with myocardial glucose uptake as measured by 18F-FDG PET/CT. In women, age was significantly correlated with myocardial substrate utilization, but not with ASM.

Body morphology and handgrip strength parameters of the female canoe slalom paddlers.

Introduction: Canoe slalom is a physically very demanding discipline, in which body constitution, body composition, and relative strength are significant factors in high performance. Although anthropometric and strength parameters are relatively well-studied in male athletes, there is a lack of evidence for any conclusions in women. Therefore, the objective of this study was to determine the morphology and upper-limb strength parameters of female canoe slalom paddlers and identify whether morphological differences exist between performance groups. Methods: Altogether, 63 female competitors of the 2023 ICF Canoe Slalom World Cup (n = 29) and 2023 ICF Canoe Slalom World Ranking Competition (n = 34) in Prague (Czech Republic) were examined with a battery of anthropometric tests, segmental bioimpedance analysis, and handgrip strength test. The athletes were divided into groups according to age and performance: elite athletes belonging to the world top 10 according to the ICF World Ranking (WORLD, n = 7), international-level athletes competing during the World Cup (ELITE, n = 22), international-level junior athletes competing in the World Ranking Race (JUNIOR, n = 17), and other lower performance-level athletes competing in the World Ranking Race (REST, n = 17). Results: Female slalom paddlers are, in general, of average body height (∼165cm), lower body mass (∼60kg), BMI (∼22kg/m2), and body fat (∼20%) and without exceptional anthropometric dimensions and proportions. However, differences were detected when performance was factored in. Female paddlers belonging to the world TOP 10 have the largest circumferences of arms and forearms, and their somatotype is more mesomorphic, with a lower proportion of total body fat and a higher proportion of muscle mass. In addition, the WORLD group differs significantly in upper-limb strength. Discussion: The results shows the significance of muscular strength and power for canoe slalom athletes and the importance of well-developed musculature in operating the boat in the unstable environment. Being a successful female canoe slalom athlete requires a well-developed musculature, maximizing strength capabilities while maintaining a low body weight through limited hypertrophy of the lower limbs and a low level of body fat.

Determination of Extra- and Intraperitoneal Fluid during Peritoneal Dialysis using Bioimpedance.

In peritoneal dialysis (PD), ultrafiltration (UF) failure is commonly attributed to dysfunction of the peritoneal membrane, resulting in decreased ultrafiltration volume (UFV). Our objective was to evaluate whether fluid absorption and UF can be assessed by monitoring intraperitoneal fluid using segmental bioimpedance analysis (sBIA). Twenty PD patients were studied during either a peritoneal equilibration test (PET; n = 7) or automated PD (APD; n = 13). Eight electrodes were positioned on the lower abdomen and connected to a bioimpedance device (Hydra 4200). A physical model of abdominal extracellular volume (VABD) was introduced, consisting of the fluid in extraperitoneal (VEPF) and the intraperitoneal cavity (VIPF). The change in the fluid surrounding the peritoneal cavity (ΔVEPF) was determined by assessing the difference in VEPF before and after PD. ΔVDwell was calculated as the difference between VABD at the end and the start of the dialysate dwell. The rate of ΔVDwell change due to UF or absorption can be estimated from VABD profiles. Total fluid (VIPF, D) in the peritoneal cavity was calculated which was used to compare actual drain volume (VDrain). VDrain and VIPF, D exhibited a strong correlation (PET: R2 = 0.98, p<0.0001; APD: R2 = 0.94, p<0.0001). Stable ΔVEPF (ΔVEPF = 0) was linked to rapid glucose transport, as measured by standard PET. This study presents a new model utilizing a bioimpedance method to monitor fluid volume across the peritoneal membrane. While the limitation of peritoneal residual volume remains unknown, this approach holds promise for providing a direct measurement of fluid transport during PD.

Segmental bioelectrical impedance analysis for Korean older population with cold pattern.

This study examined the association of whole-body composition and segmental bioimpedance variables with cold pattern (CP) in different sexes. We assigned 667 older individuals to a CP group (n = 488) and a non-CP group (n = 179) by using an eight-item self-administered questionnaire. Seven body composition variables and three pairs of segmental bioimpedance variables for the upper and lower extremities, which were obtained from a segmental multifrequency bioimpedance analyzer, were employed to investigate their association with CP. Participants' characteristics were first described. Then we compared the selected body composition and bioimpedance variables between the CP and non-CP groups. Finally, their association with CP was investigated using univariate and multivariate regression analyses. All analyses were performed separately for women and men. Both women and men exhibited a comparable mean age in the CP and non-CP groups; however, women with CP had significantly lower blood pressures, whereas men with CP showed a higher proportion of osteoarthritis than those without CP. Compared with the non-CP group, individuals with CP exhibited significantly smaller body sizes indicated by shorter height and smaller weight, lower body mass index, and smaller volume-to-body surface area ratio in both sexes. After controlling for age, height, weight, and other covariates, we found significant reductions in body lean mass such as fat-free mass and body cell mass, basal metabolic rate per unit mass, total body water, and intra-to-extracellular water ratio in the CP group. With regard to segmental bioimpedance analysis, the resistance ratios and phase angles in the upper and lower extremities yield significant associations with CP incidence, as demonstrated by the odds ratio (95% confidence interval) of 1.72 (1.16-2.57), 1.69 (1.18-2.48), 0.60 (0.40-0.89), and 0.57 (0.39-0.82), respectively. However, these results did not emerge in men. Abnormal cellular water distribution and deterioration in body cell mass and/or cell strength are associated with CP prevalence, regardless of age, height, weight. These findings are similar in the upper and lower extremities and are more pronounced in women. The abovementioned patterns may be considered effective indicators for identifying CP in the older adult population.

Segmental Bioimpedance Analysis as a Predictor of Injury and Performance Status in Professional Basketball Players: A New Application Potential?

Bioelectrical impedance vector analysis (BIVA) is a technique used for the assessment of body composition based on the electrical properties of biological tissues and for evaluating variations related to hydration and nutrition status changes. The present study aimed to investigate the possibility of predicting performance status and injuries using segmental BIVA analysis. Data were collected from 14 professional male athletes aged between 20 and 39 years of Caucasian and Afro-American ethnicity belonging to the US Victoria Libertas Pallacanestro Pesaro team in the Italian Serie A basketball championship. From an analysis of training injuries, the data highlight a possible positive link between the number of training injuries and upper hemisoma reactance (XCEmsSup) (t = 2.881, p = 0.007), an inverse relationship between training injury duration and higher right lower limb reactance (XCLegDx) (t = −4.213, p < 0.001), and an inverse relationship between injury duration and higher body mass index (t = −4.213, p < 0.001), highlighting how higher cellularity seems less prone to severe training injuries. Analyzing match-day injuries, right upper-limb higher reactance (XCArmdx) negatively correlates with match-day number of injuries (t = −4.469, p < 0.001), right upper limb resistance (RZArmDx) negatively correlates with lower match-day injury duration (t = −4.202, p < 0.001), and trunk resistance (RZTrunk) positive correlates with lower match-day injury duration (t = 2.803, p = 0.008), in contrast with the training data analysis. Analyzing the relationship between the BIVA parameters and performance indicators, right upper limb resistance (RzArmDx) has a positive link with plus–minus (t = 2.889, p = 0.007); however, RzArmDx negatively correlates with assist number (t = −3.362, p = 0.002), and BMI is directly proportional to assist number (t = 2.254, p = 0.032). These first data suggest a good correlation between the cellularity of different body districts and the risk of injuries in training but still leave several doubts surrounding the concrete predictive potential regarding performance and injuries during competitions while considering the numerous factors involved. Further studies on BIVA and similar applications could provide tools for managing athlete health and physical integrity preservation and potentially help us better understand the factors involved in improving performance.

Measurement of peritoneal fluid absorption and ultrafiltration during peritoneal dialysis using segmental bioimpedance.

The aim of this study was to measure intraperitoneal volume (IPV) and ultrafiltration volume (UFV) by monitoring the abdominal resistance using segmental bioimpedance analysis (SBIA, Hydra 4200). Twenty peritoneal dialysis (PD) patients were studied during a fill with 2 L of 2.5% glucose peritoneal dialysate solution. UFVDrain (g) was measured as weight difference between fill and drain dialysate volumes. Ultrafiltration volume (UFVSBIA; ml) and absorption volume were calculated from the IPV curve derived by SBIA. UFVSBIA correlated with UFVDrain ( ). This study may provide actionable clinical insights and help clinicians to better understand the function of the peritoneal membrane in individuals. Clinical Relevance-This technique may support personalized medicine by aiding the prescription of PD therapy on a patient-level.

Application of DSM–BIA in dry weight assessment in continuous ambulatory peritoneal dialysis

ObjectivesDry weight assessment (DWA) is an important part of dialysis and fluid management in patients receiving renal replacement therapy. With the development of bioimpedance analysis (BIA), the development of the direct segmental multi-frequency BIA (DSM–BIA) has provided a more convenient measure for DWA of dialysis patients, but its accuracy remains unclear. This study was designed to evaluate the application of DSM–BIA in DWA of continuous ambulatory peritoneal dialysis (CAPD) patients.DesignThis is a cross-sectional study. Using the conventional BIA as a reference, we examined the accuracy of the DSM–BIA technique for assessing dry weight in CAPD patients and analyzed the potential factors influencing their fluid volume status.Setting and participantsA total of 31 patients with end-stage renal disease receiving CAPD and 310 healthy volunteers were recruited for this study.MethodsThe intraclass correlation coefficients (ICC) and Bland–Altman plots were used to assess the consistency between DSM–BIA and the conventional BIA for DWA. Univariate and multivariate linear regression analyses were used to explore the influencing factors associated with the edema index.ResultsDSM–BIA and the conventional BIA technology were consistent in DWA in CAPD patients (ICC female 0.972, ICC male 0.882, ICC total 0.960). Similarly, Bland–Altman plots showed good agreements between the two methods in DWA for both genders. Univariate and multivariate linear regression analysis showed both eGFR level (P = 0.04) and serum NT-pro BNP concentration (P = 0.007) were positively correlated with the ratio of extracellular water to total body water (ECW/TCW).ConclusionsDSM–BIA in DWA has good accuracy in clinical applications and has potential application value for fluid volume management in CAPD patients.

Anthropometric Profile Assessed by Bioimpedance and Anthropometry Measures of Male and Female Rugby Players Competing in the Spanish National League

Different rugby positions make different demands on players. It therefore follows that optimum body composition may vary according to the position played. Using anthropometry and bioimpedance analysis (BIA) to assess body composition, the present study aimed to compare the effect of sex and position on body composition variables using anthropometry and BIA methods. A total of 100 competitive rugby players (35 women and 65 men) competing in the First Spanish National League were recruited voluntarily and for convenience for this study. In the laboratory, body composition was assessed by anthropometry, following the recommendations established by the International Society for the Advancement of Kinanthropometry (ISAK), and by direct segmental multi-frequency BIA, following the guidelines established by the Spanish Group of Kinanthropometry (GREC) of the Spanish Federation of Sports Medicine (FEMEDE). We found sex-related differences in height, weight, body mass index and body fat (%) by anthropometry and in body lean mass (%) by DSM-BIA, in 4 of the 6 skinfolds assessed (p &lt; 0.05). We also observed position-related differences in all the variables assessed (p &lt; 0.05) except for lean body mass, as measured by both methods of determining body composition, and front thigh skinfold. Body composition and ∑6skinfolds differs according to sex and playing position, backs (16.6 ± 3.8% and 92.3 ± 33.9 mm,) vs. forwards (20.0 ± 6.7 and 115.3 ± 37.6 mm), and the muscle-adipose (meso-endomorphic somatotype) development predominated in both sexes. Thus, forwards of both sexes are taller, heavier and fatter, possibly due to the specific demands of this position. In addition, body composition measurements vary according to the method used (DSM-BIA vs. anthropometry), indicating that anthropometry is probably the best body composition assessment method.

Estimating thigh skeletal muscle volume using multi-frequency segmental-bioelectrical impedance analysis

BackgroundThe primary aim of this study was to investigate whether using the extracellular water/intracellular water (ECW/ICW) index and phase angle combined with segmental-bioimpedance analysis (BIA) improved the model fitting of skeletal muscle volume (SMV) estimation. The secondary aim was to compare the accuracy of segmental-BIA with that of ultrasound for estimating the quadriceps SMV measured with MRI.MethodsSeventeen young men (mean age, 23.8 ± 3.3 years) participated in the study. The T-1 weighted images of thigh muscles were obtained using a 1.5 T magnetic resonance imaging (MRI) scanner. Thigh and quadriceps SMVs were calculated as the sum of the products of anatomical cross-sectional area and slice thickness of 6 mm across all slices. Segmental-BIA was applied to the thigh region, and data on the 50-kHz bioelectrical impedance (BI) index, ICW index, ECW/ICW index, and phase angle were obtained. The muscle thickness index was calculated as the product of the mid-thigh muscle thickness, determined using ultrasound, and thigh length. The standard error of estimate (SEE) of the regression equation was calculated to determine the model fitting of SMV estimation and converted to %SEE by dividing the SEE values by the mean SMV.ResultsMultiple regression analysis indicated that the combination of 50-kHz BI and the ECW/ICW index or phase angle was a significant predictor when estimating thigh SMV (SEE = 7.9 and 8.1%, respectively), but were lower than the simple linear regression (SEE = 9.4%). The ICW index alone improved the model fitting for the estimation equation (SEE = 7.6%). The model fitting of the quadriceps SMV with the 50-kHz BI or ICW index was similar to that with the skeletal muscle thickness index measured using ultrasound (SEE = 10.8, 9.6 and 9.7%, respectively).ConclusionsCombining the traditionally used 50-kHz BI index with the ECW/ICW index and phase angle can improve the model fitting of estimated SMV measured with MRI. We also showed that the model suitability of SMV estimation using segmental-BIA was equivalent to that on using ultrasound. These data indicate that segmental-BIA may be a useful and cost-effective alternative to the gold standard MRI for estimating SMV.

Using segmental bioimpedance analysis to estimate soft tissue and chemical composition of retail cuts and carcasses of lambs

This study evaluated the potential of segmental bioimpedance analysis (SBIA) to estimate the composition of retail cuts and their predictability to infer on the carcass composition in lambs. Leg, rib, shoulder, neck, and loin from thirty-one lamb carcasses were evaluated. A single-frequency bioelectrical impedance analyzer at 50 kHz was used to perform measurements. The models for estimating soft tissue showed the highest accuracy in the retail cuts. Lean and fat weight of the lamb cuts or of the carcasses were predicted with R2 of calibration ranging from 86.6 to 99.1% and from 67.5 to 95.4%, respectively. Segmental bioimpedance analysis is an accurate technology to assess physical and chemical components in retail cuts of lamb. Despite that, shoulder was the most representative cut; all cuts evaluated through SBIA were valuable to estimate the components of the edible portion of lamb carcasses.

P1183EFFECT OF DECREASE IN GLUCOSE GRADIENT ON CHANGE IN INTRAPERITONEAL VOLUME USING SEGMENTAL BIOIMPEDANCE DURING PET

Abstract Background and Aims The aim of this study was to investigate relationship of glucose gradient dynamics with change in intraperitoneal volume (IPV) measured by segmental bioimpedance analysis (SBIA). Method Ten PD patients (age 59±8.8 years, 7 females, 5 Blacks, weight 69.8±12.4 kg) were studied during standard peritoneal equilibrium test (PET). Dialysate glucose concentration (D) was measured hourly throughout the PET. IPV was monitoring continuously using SBIA (Hydra 4200; Zhu et al, Kidney Blood Press Res 2019). Hourly IPV was used to calculate (1) the difference between two conservative hours (ΔIPVt = IPVt+1 - IPVt; t=0, 1, 2 and 3) and (2) the IPVt / IPV0 ratio vs. the concurrent Dt/D0. Results IPVs were successfully measured in nine patients (1 high transporter, 6 high-average, 2 low-average). Ultrafiltration volume (UFV, 0.55±0.17 L) at the end of dwell was measured by SBIA. ΔIPV1(0.26±0.17 L) was positive during the first hour of dialysate dwell in 7 patients, their corresponding ΔD1 (calculated as D1 – D0) was -902±278 mg/dL. However, 2 patients (1 high and 1 high-average transporter) showed negative ΔIPV1(-0.13±0.1 L) and a ΔD1 of -861±367 mg/dL. The relationship between IPVt/ IPV0 and Dt/D0 is shown in Fig.1 (a) – (i). The figures indicate the dynamics of IPV and glucose concentration changes in all 9 patients. Conclusion Peak IPV appears at different time points and is associated with different glucose gradients. These findings may represent specific, individual characteristics of the peritoneal membrane. Since first hour ΔIPV represents almost half of total UFV at the end of dwell, it could emerge as an important indicator of peritoneal membrane characteristics. Monitoring IPV using SBIA provides a useful tool for further investigation.

Multi-Frequency Bioimpedance Reliability and Validity for Assessing Total and Segmental Body Composition in College-Aged Males

Bioimpedance analysis (BIA), which may be affected by hydration status, is frequently used to assess total and segmental body composition for research purposes. However, the reliability and validity of BIA in determining body composition in all populations including well hydrated college aged males has not been determined. PURPOSE: To determine the reliability of direct segmental multi-frequency BIA and its validity against dual energy x-ray absorptiometry (DXA) in a population of normally hydrated college-aged males. METHODS: Body composition was measured in the early morning 3 times in the following order: 1) BIA, 2) DXA, and 3) BIA, all in the same session lasting < 30 minutes. Immediately prior to body composition measurement, a urine sample was collected and analyzed for urine specific gravity (USG). To ensure normal hydration, a USG of 1.022-1.028 encompassing slightly dehydrated, euhydrated, and well hydrated statuses was required for study participation. RESULTS: A total of 102 males (mean age = 20.35 ± 1.38 years) were included in the analyses. Intra-class correlations between the two BIA determined fat free mass (FFM) of total body, right arm, left arm, trunk, right leg and left leg were .974, .961, .965, .963, .994, and .994, respectively. Two-tailed paired samples t-tests showed all comparisons of DXA FFM (bone mineral content [BMC] + lean mass) compared to the average of the two BIA FFM (comparable to DXA BMC + lean mass) to be significantly different (p <. 001) except for the trunk (p = .242). Segmental BIA FFM underestimated segmental DXA FFM by ≤ 1.05kg, while total body BIA FFM overestimated total body DXA FFM by 2.2kg. CONCLUSIONS: Multi-frequency BIA is reliable in determining total and segmental FFM. The significant differences between DXA and BIA in determining segmental FFM may be due to body composition derived from DXA is based on attenuation of x-ray to determine BMC, lean tissue, and fat mass while; body composition derived from BIA is based on impedance of body water content.

Agreement Between 2 Segmental Bioimpedance Devices, BOD POD, and DXA in Obese Adults

This study examined the agreement between 2 segmental bioimpedance analysis (BIA) devices, air displacement plethysmography (BOD POD), and dual energy X-ray absorptiometry (DXA) for estimating body composition in obese adults. Fifty obese adults (25 men and 25 women; age = 34.20 ± 11.19 years; BMI = 36.14 ± 5.33 kg/m2) had their body fat percentage (BF%) and fat-free mass (FFM) evaluated with 2 segmental BIA devices (InBody 230 and InBody 720), BOD POD, and DXA (Lunar iDXA). Body composition via the BOD POD was determined using the Siri equation whereas manufacturer-based equations generated metrics (ie, BF% and FFM) for the InBody devices. The effect size of the mean differences for all BF% and FFM comparisons were trivial (Cohen's d < 0.20). The standard error of estimate (SEE), total error (TE), and 95% limits of agreement (LOAs) were low for both segmental BIA devices when compared to DXA (SEE < 2.26% and 2.35 kg; TE < 2.58% and 2.66 kg; 95% LOAs < ± 4.94% and 4.86kg). The error for BOD POD was also low when compared to DXA (SEE = 2.39% and 2.57 kg; TE = 2.34% and 2.56 kg; 95% LOAs = 4.63% and 5.06 kg). Validity statistics were slightly higher, but considered acceptable, when comparing the segmental BIA devices against BOD POD (SEE < 3.37% and 3.63 kg; TE < 3.44% and 3.79 kg; 95% LOAs < ± 6.62% and 7.19 kg). Lastly, the 2 segmental BIA devices produced nearly identical validity statistics when compared to each other. However, both BIA devices revealed proportional bias for BF% and FFM when compared to the BOD POD and DXA (all p < 0.05). The current study's findings indicate the InBody 230 is interchangeable with the InBody 720 in obese adults. Also, the trivial effect size, when compared against the BOD POD and DXA, suggest the InBody devices could be used for estimating group BF% and FFM. In contrast, the significant proportional bias demonstrates the BIA devices are not acceptable for individual estimates of body composition in an obese clinical population.

Monitoring of Intraperitoneal Fluid Volume during Peritoneal Equilibration Testing using Segmental Bioimpedance

Background: Ultrafiltration failure and fluid overload are common in peritoneal dialysis (PD) patients. Knowledge of intraperitoneal volume (IPV) and time to peak IPV during a dwell would permit improved PD prescription. This study aimed to utilize trunk segmental bioimpedance analysis (SBIA) to quasi-continuously monitor IPV (IPV_SBIA) during the peritoneal dwell. Methods: IPV_SBIA was measured every minute using lower-trunk SBIA (Hydra 4200; Xitron Technologies Inc., CA, USA) in 10 PD patients during a standard 240-min peritoneal equilibration test (PET). The known dialysate volume (2 L) rendered IPV_SBIA calibration and calculation of instantaneous ultrafiltration volume (UFV_SBIA) possible. UFV_SBIA was defined as IPV_SBIA – 2 L. Results: Based on dialysate-to-plasma creatinine ratio, 2 patients were high, 7 high-average, and 1 low-average transporters. Technically sound IPV_SBIA measurements were obtained in 9 patients (age 59.0 ± 8.8 years, 7 females, 5 African Americans). Drained ultrafiltration volume (UFV_drain) was 0.47 ± 0.21 L and correlated (r = 0.74; p < 0.05) with end-dwell UFV_SBIA (0.55 ± 0.17 L). Peak UFV_SBIA was 1.04 ± 0.32 L, it was reached 177 ± 61 min into the dwell and exceeded end-dwell UFV_SBIA by 0.49 ± 0.28 L (95% CI: 0.27–0.7) and UFV_drain by 0.52 ± 0.31 L (95% CI: 0.29–0.76), respectively. Conclusion: This pilot study demonstrates the feasibility of trunk segmental bioimpedance to quasi-continuously monitor IPV_SBIA and identify the time to peak UFV_SBIA during a standard PET. Such new insights into the dynamics of intraperitoneal fluid volume during the dwell may advance our understanding of the underlying transport physiology and eventually assist in improving PD treatment prescriptions.

Clinical usefulness of bioimpedance analysis for assessing volume status in patients receiving maintenance dialysis.

Chronic volume overload is associated with left ventricular hypertrophy and high cardiovascular mortality in patients undergoing dialysis. Therefore, estimating body fluid status is important in these patients. However, most dry-weight assessments are still performed clinically, while attempts have been made to measure the volume status and dry weight of patients undergoing dialysis using bioimpedance analysis (BIA). BIA uses the electrical properties of the human body to alternate current flow and measures resistance values to estimate body water content and composition. BIA is divided into single-frequency BIA, multi-frequency BIA, and bioimpedance spectroscopy (BIS) according to the number of frequencies used, and into whole-body and segmental BIA according to whether or not the whole body is divided into segments. Extracellular water (ECW), intracellular water, and total body water (TBW) contents can be measured with BIA. Dry weight can be estimated by measuring the volume overload of the patient through the ECW/TBW and ECW-to-body weight ratios. Other estimation methods include the normovolemia/hypervolemia slope method, a resistance-reactance (RXc) graph, overhydration measurements using a body composition monitor, and calf BIS. In this review, we will examine the principles of BIA, introduce various volume status measurement methods, and identify the optimal method for patients undergoing dialysis.

Prediction of hemodialysis vascular access failure using segmental bioimpedance analysis parameters.

Segmental bioimpedance analysis (BIA) can identify fluid volume changes in the arms of patients on hemodialysis (HD) after vascular access surgery. We investigated whether the difference in fluid volumes between the arms of the patients using segmental BIA is associated with vascular access outcome. Body composition measurements were taken for 127 patients on HD with segmental, multi-frequency BIA equipment (InBody 1.0, Biospace Co. Ltd, Seoul, Korea). The difference in fluid volume between the arms of the patients was calculated from the fluid volume of the arm with the vascular access minus that of the other. The primary outcome was the loss of vascular access patency within 3months of BIA measurement. The median absolute and relative inter-arm fluid volume differences were 150ml [interquartile range (IQR) 90-250ml] and 9.6% (IQR 4.9-14.4%), respectively. Within 3months of BIA measurement, 38 patients (30.0%) experienced vascular access failure. When the patients were divided into three groups based on the tertiles of relative inter-arm fluid volume differences (lowest tertile:<6.8%; middle tertile: 6.8-12.7%; highest tertile:>12.7%), greater difference in relative inter-arm fluid volume differences was associated with higher vascular access failure rates (14 vs. 28 vs. 48%, p value for trend across tertiles=0.003). We conclude that segmental BIA may be used as a tool that can predict vascular access failure in patients on HD by calculating the relative difference in fluid volume between the arms of the patients with and without vascular access.

Evaluation of a Novel Bioimpedance Analysis Equation Development Approach

Traditional bioimpedance analysis (BIA) prediction equations developed at 50 kHz for %fat often include population‐specific predictor variables such as age, sex, and race. Recent studies suggest that good generalizable %fat prediction equations can be developed without population‐specific variables if segmental impedance (Z) measurements at variable frequencies are used in model development. The current study tested this hypothesis using the 8‐electrode Selves Healthcare X Scan PLUS 970 (Seoul, South Korea) multifrequency segmental BIA system in a two‐phase study in 161 ethnically mixed adults (9 African American, 109 white, 43 other). Subjects ranged widely in age (15–72 years) and BMI (16.5–40.4 kg/m2). Using dual‐energy X‐ray absorptiometry (DXA, GE Lunar Prodigy) as the reference for fat‐free mass (FFM), 86 subjects had segmental impedances measured at 5, 50, and 250 kHz in phase I. Stepwise multiple linear regression analysis was then used to develop the FFM prediction model. The developed %fat (= 100 × [weight‐FFM/weight]) model was then validated in 75 phase II subjects. The developed model has 6 segmental Z predictor variables (hand‐hand, foot‐foot, left hand‐left foot, left hand‐right foot, right hand‐right foot, right hand‐left foot) indexed to either height or weight; age, sex, and race did not enter the final model. Predicted BIA %fat and DXA %fat in phase II subjects were highly correlated (R2=0.91, p&lt;0.0001) and the Bland‐Altman plot slope was non‐significant. Comparable prediction models were developed for other similar multifrequency BIA systems (e.g., Selves Healthcare 357s). Highly predictive BIA %fat models can thus be developed from multiple frequency segmental impedance measurements that capture variance related to age, sex, and race. These models do not require the addition of potentially population‐specific covariates to %fat prediction formulas.

Segmental bioimpedance analysis in professional cyclists during a three week stage race

Bioelectrical impedance analysis has been widely used in the clinical and sport areas because it is a safe, non-invasive, rapid and inexpensive technique that evaluates some electrical properties of the body, such as resistance (R), reactance (Xc) and phase angle (PhA).The aim of this study is to evaluate body composition changes in professional cyclists, participating at the Giro D’Italia 2012, a three week stage race, and in particular PhA modifications as an expression of fat free mass nutritional status.Data were collected at the beginning, in the middle and at the end of the competition. Body weight, circumferences, skinfold thickness and BIA variables (total and segmental body) were measured.Body composition, measured by skinfold thickness, changed during the competition: fat free mass increased, but not significantly, in the middle and at the end of the competition, whereas fat mass significantly decreased versus the baseline in the middle and at the end of the competition. The total PhA did not significantly change in the middle of the competition but was significantly reduced at the end. The arm PhA did not change significantly at both times of the competition, whereas a significant reduction was reported for leg PhA in the middle and at the end of the competition.These results suggest the use of bioimpedance analysis, in particular PhA measurement, to monitor athletes’ fat free mass characteristics during medium- and long-term competitions.

Broadcasting Not Properly: Using B-type Natriuretic Peptide Interval Likelihood Ratios and the Results of Other Emergency Department Tests to Diagnose Acute Heart Failure in Dyspneic Patients.

Broadcasting Not Properly: Using B-type Natriuretic Peptide Interval Likelihood Ratios and the Results of Other Emergency Department Tests to Diagnose Acute Heart Failure in Dyspneic Patients.

Assessment of body composition of Sri Lankan Australian children using ethnic specific equations

Since ethnic differences exist in body composition, assessment methods need to be validated prior to use in different populations. This study attempts to validate the use of Sri Lankan based body composition assessment tools on a group of 5 - 15 year old Australian children of Sri Lankan origin. The study was conducted at the Body Composition Laboratory of the Children’s Nutrition Research Centre at the Royal Children’s Hospital, Brisbane, Australia. Height (Ht), weight (Wt), segmental length (Lsegment name) and skinfold thickness (SFT) were measured. The whole body and segmental bio impedance analysis (BIA) were also measured. The body composition determined by the deuterium dilution technique (criterion method) was compared with the assessments done using prediction equations developed on Sri Lankan children. 27 boys and 15 girls were studied. All predictions of body composition parameters, except percentage fat mass (FM) assessed by the SFT-FM equation in girls gave statistically significant correlations with the criterion method. They had a low mean bias and most were not influenced by the measured parameter. Although living in a different socioeconomic state, the equations developed on children of the same ethnic background gives a better predictive value of body composition. This highlights the ethnic influence on body composition. J.Natn.Sci.Foundation Sri Lanka 2015 43 (2): 111-118