The role of segmental bioelectrical impedance technique in the assessment of intraperitoneal ultrafiltration volume with peritoneal dialysis patients.

OBJECTIVE: To investigate the role of segmental bioelectrical impedance technique (SBIA) in the assessment of intraperitoneal ultrafiltration volume with peritoneal dialysis patients. METHOD: We selected the patients at the Department of Nephrology of the First Affiliated Hospital of Zhengzhou University and measured the segmental bioelectrical impedance by a German Fresenius body composition analyzer (the Fresenius whole body composition measurement (BCM) machine was used as a segmental machine in this study). An alternating current (5 kHz, 0.05-0.7 mA) was continuously released during the measurement. The released current penetrated the peritoneal cavity on both sides of the body, from which the segmental resistance at a frequency of 5 kHz was obtained from the multifrequency data (R5/Ω). Baseline BIA measurements were initiated after the patient entered the supine position for 5-10 min, then dialysate was instilled into the peritoneal cavity. BIA measurements were performed at 10-min intervals during the retention of dialysate in the abdomen and finally ended when dialysate drainage was complete. Real-time intraperitoneal volume estimated by SBIA (IPVSBIA)and ultrafiltration volume estimated by SBIA(UFVSBIA) was calculated. At the same time, the actual ultrafiltration volume at the end of peritoneal dialysis was weighed and measured (UFVMEA). RESULTS: A total of 30 patients were included in the study, 9 patients withdrew from the study due to subjective factors during the measurement process, and 21 patients completed the study. The correlation coefficient R2 of UFVSBIA and UFVMEA was 0.21 (p < 0.05). Bland-Altman analysis showed that the bias of UFVSBIA to the actual UFVMEA was 0.12 L, and the 95% agreement limit was between -0.5 L and 0.74 L, which confirmed that UFVSBIA measured by electrical impedance method and UFVMEA measured by weighing method were in good agreement. The time required to reach the maximum ultrafiltration volume (UFVSBIA) was 108 ± 68 min, and the mean value of the maximum ultrafiltration volume (Max UFVSBIA) was 1.16 ± 0.60 L. CONCLUSION: The segmental bioelectrical impedance technique can be used to assess the intraperitoneal ultrafiltration volume of peritoneal dialysis patients in real-time and effectively. This method may guide the dialysis fluid retention time and the maximum ultrafiltration volume in PD patients.

Water Distribution Changes in Complex Decongestive Treatment for Leg Lymphedema: Quantitative Evaluation by Direct Segmental Multi-Frequency Bioimpedance Analysis.

Background: There is a need for a simple method for the quantitative evaluation of lymphedema swelling. In this study, we performed a direct segmental multi-frequency impedance analysis in patients with leg lymphedema. Methods: The subjects were 36 patients (6 men and 30 women) with 46 lymphedema legs. The average age was 61 years. All patients had International Society of Lymphology stage II lymphedema. Swelling ratio and ultrasound subcutaneous tissue echo-free space (FS) were examined. InBody 770 was used to measure the extracellular water (ECW), intracellular water (ICW), and total body water (TBW) volumes. Changes before and after complex decongestive treatment (CDT) were examined. Results: In 26 unilateral cases, the ECW, ICW, and TBW volumes of the affected legs were higher than those of the contralateral unaffected legs, and the ECW/TBW ratio was significantly higher in the affected legs (0.41) than in the contralateral unaffected legs (0.391). There was a significant correlation between the leg swelling ratio and the ECW/TBW ratio between the affected and contralateral unaffected legs (correlation coefficient=0.882). Ultrasound findings of the 46 affected legs were classified into no FS (group 0), minimal or only horizontal FS (group 1), and cobblestone-like FS (group 2). The ECW/TBW ratio of the affected legs in each group was 0.393 (14 legs), 0.407 (10 legs), and 0.426 (22 legs) respectively, demonstrating significant differences among the 3 groups. After CDT, the amount of water decreased in the affected legs and increased in the trunks and both upper limbs. The ECW/TBW ratio decreased significantly, from 0.432 to 0.414 in the affected legs, from 0.401 to 0.392 in the unaffected legs, and from 0.413 to 0.402 in the trunks. The ECW/TBW ratio had not changed and remained below 0.4 in the upper limbs. Conclusion: The segmental water contents measured by direct segmental multi-frequency impedance analysis correlates well with the degree of lymphedema swelling, and subcutaneous echo findings and can demonstrate water distribution change before and after CDT, which is considered to be a useful quantitative evaluation method for lymphedema. (This is secondary publication from Jpn J Phlebol 2020; 31(1): 1-7.).

Effects of resistance training intensity on muscle quantity/quality in middle-aged and older people: a randomized controlled trial.

BACKGROUND: A sarcopenia diagnosis is confirmed by the presence of low muscle quantity or quality under the 2018 revised definition by the European Working Group on Sarcopenia in Older People 2. Imaging methods [i.e. magnetic resonance imaging (MRI)], dual-energy X-ray absorptiometry (DXA), and bioelectrical impedance analysis are tools to evaluate muscle quantity or quality. The present study aimed to investigate whether and how low-intensity and moderate-intensity resistance training improved both muscle quantity and quality measured by MRI, DXA, and segmental bioelectrical impedance spectroscopy (S-BIS) in middle-aged and older people. METHODS: A single-blind, randomized, controlled trial was conducted. Community-dwelling people aged 50-79 years were randomly allocated to no exercise (no-Ex), low-intensity exercise (low-Ex), and moderate-intensity exercise (moderate-Ex) groups. Participants in the exercise groups performed resistance training for 24 weeks, with loads of 40% and 60% of one repetition maximum in the low-Ex and moderate-Ex groups, respectively. Cross-sectional area (CSA), lean mass, and muscle electrical properties on S-BIS were used to determine the effects of training interventions on muscle quantity and quality of the lower limbs. RESULTS: Fifty participants (no-Ex 17, age 63.5 ± 8.5 years, women 47.1%; low-Ex 16, age 63.6 ± 8.1 years, women 50.0%; moderate-Ex 17, age 63.5 ± 8.3 years, women 52.9%) completed the 24 week exercise intervention. For the primary outcome, significant intervention effects were found in thigh muscle CSA on MRI between the moderate-Ex and no-Ex groups (+6.8 cm2 , P < 0.01). Low-Ex for 24 weeks only increased quadriceps CSA (+2.3 cm2 , P < 0.05). The per cent change of thigh muscle CSA (+7.0%, P < 0.01) after 24 week moderate-Ex was higher than that of leg lean mass on DXA (+2.3%, P = 0.088). Moderate-Ex for 24 weeks also improved S-BIS electrical properties related to muscle quantity and quality, including the intracellular resistance index (+0.1 cm2 /Ω, P < 0.05), membrane capacitance (+0.7 nF, P < 0.05), and phase angle (+0.3 deg, P < 0.05); their changes were positively correlated with that of thigh muscle CSA (P < 0.01). CONCLUSIONS: Resistance exercise with moderate intensity improved muscle quantity and quality measured by MRI and S-BIS, whereas that with low intensity only increased muscle quantity in middle-aged and older people. The comparisons among the responses to exercise between the assessment methods indicate the greater value of MRI and S-BIS to measure changes of muscle quantity and quality than of lean mass measured by DXA for assessing the local effects of resistance training.

Association of bioelectrical phase angle with aerobic capacity, complex gait ability and total fitness score in older adults.

PURPOSE: This study aimed to examine the association between whole-body or segmental phase angle (PhA) based on bioelectrical impedance analysis (BIA) and aerobic capacity (endurance), complex gait ability, and total fitness age score (FAS). METHODS: A total of 426 community-dwelling older adults (332 women and 94 men) aged 60 to 93 years participated in this study. PhA and appendicular skeletal mass index (ASMI) were obtained by an eight-electrode standing BIA. Aerobic capacity was assessed using the shuttle stamina walk test (SSTw); complex gait ability, using the timed-up-and-go test (TUG). FAS was obtained using the previously validated multi-dimensional equations based on 7-year longitudinal data. SSTw, TUG, and FAS were compared between the low PhA (<4.4° for women and <5.2° for men) and normal PhA groups. Pearson's correlation between PhA and SSTw, TUG, and FAS was determined. Multiple linear regression analysis was conducted using SSTw, TUG, and FAS as dependent variables. Age, sex, height, body mass index (BMI), ASMI, and PhA were entered into the linear model. RESULTS: SSTw and TUG results and FAS were significantly lower in the low PhA group (P < 0.05). PhA was significantly correlated with SSTw, TUG, and FAS (P < 0.001), and leg PhA showed a stronger correlation than whole-body or arm PhA. PhA at 50 kHz had higher correlation coefficients with SSTw, TUG, or FAS compared with PhA at 5 or 250 kHz. Multiple regression analyses indicated that leg PhA at 50 kHz was a significant predictor of SSTw, TUG, and FAS, independent of age, sex, height, BMI, and ASMI. CONCLUSION: Our results indicate that leg PhA is associated with multi-dimensional physical fitness in community-dwelling older adults. PhA is a highly informative biomarker of skeletal muscle and exercise physiology in clinical settings.

Leg electrical resistance predicts venous blood viscosity and hematocrit.

 We previously reported that whole body bioelectrical impedance analysis (BIA) measurements are correlated to some hemorheologic factors, suggesting a relationship between viscosity factors and electric properties of flowing blood not only in vitro but also in vivo. Recently we reported that with segmental BIA (analyzing the body considered as composed of 5 cylinders) predictive equations for various determinants of blood viscosity were closer than for the wole body. Another widely used BIA technique uses leg-to-leg impedance measurements so that two cylinders (the two legs) are analyzed. We investigated whether impedance measured with this technique (Tanita TBF-300) is also a predictor of blood viscosity factors. From viscometric measurements performed on venous blood drawn in recreative athletes over the range of shear rates 1 to 6000 s-1 (RHEOMETRE Anton Paar CP 50-1), we found a correlation between leg-leg resistance at 50 kHz (Rx[50 kHz]) and blood viscosity at 1000 s-1 (η1000= 0.0051 Rx[50 kHz] + 1.3265; r = 0.521 p = 0.028 yielding a prediction of η1000 (Bland Altman plot: bias 0.05 [RANGE - 0.24; 0.34]. Neither plasma viscosity nor the red cell rheology index «k¼ of Quemada's model are correlated with Rx[50 kHz], but hematocrit (Hct) does (Hct (%) = 0.0217 Rx[50 kHz] + 33.783; r = 0.480 p = 0.044) yielding a prediction of Hct (Bland Altman plot: bias - 0.11, [range - 1.67; 1.45]. The discrepancy between actual and predicted Hct is also correlated with resistance at 50 kHz (r = 0.575 p = 0.031) as does the discrepancy between actual and predicted Hct/viscosity ratio (r = -0.651 p = 0.006). Therefore, as other previously studied methods, leg to leg BIA predicts viscosity, suggesting that blood rheology may influence the passage of an electric current in the legs.

Segmental bioelectrical impedance analysis (SBIA) and blood rheology: Reducing the gap between in vivo and in vitro?

Bioelectrical impedancemetry (BIA) has been used to evaluate hematocrit and red cell aggregability in vitro but whole body impedance measurements are also correlated to some hemorheologic factors, suggesting a relationship between viscosity factors and electric properties of blood. We repeatedly reported correlations with whole body BIA and hematocrit, whole blood viscosity and plasma viscosity, red cell rigidity and RBC aggregation. The SBIA Inbody 770 modelizes body as 5 cylinders and measures impedance at 1, 5, 50, 250, 500, and 1000 kHz. With the SBIA we found that hematocrit is best correlated to leg reactance at 50 kHz but also to leg impedance at 1 and 5 kHz and trunk reactance. RBC aggregation "M" is best correlated to arm reactance at 5 kHz but also to most measurements of segmental impedance (28 correlations found). RBC aggregation "M1" is best correlated to arm reactance at 5 kHz and to 19 other impedance measurements. A predictive equation for "M" from the mean between the two arm reactances at 5 kHz (maXc5) is found: M = 2.1845maXc5-23.958 (r = 0.665, p < 0.001) that provides a satisfactory Bland-Altman plot (mean difference: 0.000524 range [-1.6;+1.6]. This study suggests that previously reported correlations between BIA and viscosity factors were not spurious, and that in a narrow cylinder such as the arm the structure of circulating blood (hematocrit, red cell aggregation) may influence the passage of an electric current by increasing reactance.

Whole-body versus segmental bioelectrical impedance analysis in patients with edema of the upper limb after breast cancer treatment.

AIM: The purpose of this study was to compare whole-body (50 kHz alternating current) and segmental (5 kHz alternating current) bioelectrical impedance analysis (BIA) in the assessment of manifested edema of the upper limbs. PATIENTS AND METHODS: Whole-body and segmental BIA were performed in 30 patients with edema of the upper limb following breast cancer treatment. RESULTS: Pearson correlation coefficient comparing both measurements was 0.8891 (p-value <0.0001) with corresponding least squares (r(2)) of 0.7904. CONCLUSION: Whole-body BIA seems to be a suitable method in the assessment of manifested edema of the upper limbs.

Inter-sport variability of muscle volume distribution identified by segmental bioelectrical impedance analysis in four ball sports.

The aim of this study was to evaluate and quantify differences in muscle distribution in athletes of various ball sports using segmental bioelectrical impedance analysis (SBIA). Participants were 115 male collegiate athletes from four ball sports (baseball, soccer, tennis, and lacrosse). Percent body fat (%BF) and lean body mass were measured, and SBIA was used to measure segmental muscle volume (MV) in bilateral upper arms, forearms, thighs, and lower legs. We calculated the MV ratios of dominant to nondominant, proximal to distal, and upper to lower limbs. The measurements consisted of a total of 31 variables. Cluster and factor analyses were applied to identify redundant variables. The muscle distribution was significantly different among groups, but the %BF was not. The classification procedures of the discriminant analysis could correctly distinguish 84.3% of the athletes. These results suggest that collegiate ball game athletes have adapted their physique to their sport movements very well, and the SBIA, which is an affordable, noninvasive, easy-to-operate, and fast alternative method in the field, can distinguish ball game athletes according to their specific muscle distribution within a 5-minute measurement. The SBIA could be a useful, affordable, and fast tool for identifying talents for specific sports.

Anthropometry and bioelectrical impedance analyis compared to dual-photon absorptiometry for the assessment of body composition of hiv-seropositive patients / Antropometría y análisis de impedancia bioeléctrica comparado con absorciometría fotónica dual para la evaluación de la composición corporal en pacientes infectados por vih

Introduction: HIV-seropositive patients have shown changes in body composition such as lipoatrophy in certain regions of the body and lipohypertrophy in others, representing characteristics of lipodystrophy syndrome. It is important to monitor the quantity of fat per body segment using practical and low-cost methods in order to optimize the treatment of this group. Objectives: To correlate the body composition per body segment obtained by anthropometric measurements and by segmental bioelectrical impedance with DXA in HIV-seropositive patients on antiretroviral treatment Methods: We measured circumferences (arm, waist, hip, thigh and calf) and skinfolds (biceps, triceps, subscapular, suprailiac) and performed segmental bioelectrical impedance (BIA) analysis and DXA. The Pearson test was used to determine correlations and the St. Laurent test was used to assess concordance between variables. Results: We evaluated 26 patients, 35% of whom were overweight. The triceps skinfold (TSF), waist circumference (WC) and thigh circumference (TC) were significantly correlated with the measurement obtained by the gold standard (p<0.01). There was no concordance between the values obtained by segmental BIA and by DXA. Conclusions: Anthropometric measurements such as TSF, WC and TC are importantfor the monitoring of changes in body composition among HIV-seropositive patients on antiretroviral treatment. Segmental BIA did not prove to be appropriate for the assessment of body composition in HIV-seropositive patients.

Introducción: Se ha descrito cambios en la composición corporal de pacientes infectados por VIH, tales como la lipoatrofia en ciertas regiones del cuerpo y lipohipertrofia en otros, en representación de las características del síndrome de lipodistrofia. Es importante controlar la cantidad de grasa corporal por segmento utilizando métodos prácticos y de bajo costo con el fin de optimizar el tratamiento de este grupo. Objetivos: correlacionar la composición corporal por segmento corporal obtenidos por las mediciones antropométricas y por impedancia bioeléctrica com DXA segmentaria en pacientes seropositivos al VIH en tratamiento antir-retroviral. Métodos: Se midieron las circunferencias de brazo, cintura, cadera, muslo y pantorrilla y los pliegues cutáneos: bíceps, tríceps, subescapular, suprailíaco) y se realizaron impedancia bioeléctrica segmentaria (BIA) el análisis y DXA. La prueba de Pearson se utilizó para determinar las correlaciones y la prueba de San Lorenzo se utilizó para evaluar la concordancia entre las variables. Resultados: Se evaluaron 26 pacientes, 35% de los cuales tenían sobrepeso. El pliegue del tríceps (PT), circunferencia de la cintura (CC) y la circunferencia del muslo (CM) se correlacionaron significativamente con la medida obtenida por el patrón de oro (p <0.01). No hubo concordancia entre los valores obtenidos por BIA y DXA segmentaria. Conclusiones: Las mediciones antropométricas como PT, CC y CM son importantes para el seguimiento de los cambios en la composición corporal de los pacientes infectados por VIH que reciben tratamiento antirretroviral. La BIA segmental no demostró ser adecuado para la evaluación de la composición corporal en pacientes infectados por VIH.

Determinación de composición corporal mediante análisis de impedancia segmentada: consideraciones y aplicaciones prácticas / Determination of body composition by segmental bioeletrical impedance analysis: considerations and practical applications

Introduction: Bioelectrical impedance is a fast, inexpensive, easy, portable, and noninvasive method. A major innovation in the analysis of body composition is segmental bioelectrical impedance. Objectives: To assess the applicability of segmental bioelectrical impedance. Subjects and methods: The study was conducted on female subjects divided into two groups: Group I (n =8) consisted of healthy women and group II (n=25) of obese women with Polycystic Ovary Syndrome (PCOS). All subjects were submitted to examination by total and segmental bioelectrical impedance. Results and discussion: Anthropometric parameters (weight, BMI, total lean mass and total fat mass) showed significant differences between groups. There was a significant difference between groups I and II for all body segments evaluated, except for lean mass of the leg. Conclusion: Procedures of segmental bioelectrical impedance will be increasingly useful in the nutritional assessment of tissue masses, enabling assessment that is more sensitive and monitoring of nutritional care.

Introdução : A impedância bioelétrica é um método rápido, barato, fácil, portátil e nao invasivo. Urna grande inovação na análise da composição corporal é a Impedância Bioelétrica Segmentar. Objetivos: Avahar a aplicabilidade da impedância bioelétrica segmentar. Sujetos e Métodos: o estudo foi realizado com individuos do sexo feminino, divididos em: Group I (n=8) composto por mulheres eutróficas e o Group II (n=25) mulheres obesas com Síndrome do Ovario Policístico (SOP). Todos os individuos foram submetidos ao exame de impedância bioelétrica total e segmentar. Resultados e discussão : Os parâmetros antropométricos de peso, IMC, massa magra total e massa gorda total apresentaram diferencas significativas entre os groups. Houve diferenca significativa para todos os segmentos corporais avahados, com exceção da massa magra da perna entre o group I e II. Conclusão : Procedimentos de impedância bioelétrica segmentar serão cada vez mais úteis na avaliação nutricional de massas teciduais, possibilitando avaliações e monitoramentos mais sensíveis do cuidado nutricional.

LIMB MUSCLE MASS DECREASE WITH AGING IN JAPANESE MEN AND WOMEN AGED 15-97 yr / 体力科学

Although skeletal muscle mass decreases with aging, its decrease rate may differ among parts of the body. There have been few studies examining the differences in the muscle mass decrease rate between proximal and distal parts of the limbs or between the left and right legs in a large population. Bioelectrical impedance (BI) index, calculated as the ratio of the square of segment length to impedance, is linearly correlated with the muscle mass calculated by MRI (r=0.902-0.976, p<0.05, Miyatani et al., 2001) in the limb segments. The purpose of this study was to examine differences in the decrease rate of muscle mass between the proximal and distal parts of the limbs and between the upper and lower limbs in healthy Japanese. The BI index was measured in the bilateral thighs, lower legs, upper arms, and forearms of 1006 healthy Japanese men and women (aged 15-97 years). While the BI index decreased with aging in all examined parts of the body, the decrease rate was larger in the lower limb than in the upper limb, and in the thigh than in the lower leg. The percentage of people who showed a difference of more than 10 % in the BI index between the left and right lower limbs was significantly higher in the elderly than in young subjects. These differences in the decrease rate of muscle mass between limbs may be associated with decreases in physical functions in the elderly.