Segmental Bioelectrical Impedance Analysis Research Articles

Which sub-compartments of fat mass and fat-free mass are related to blood viscosity factors?

The size of body compartments is a determinant of several factors of blood viscosity. Red cell aggregation is proportional to fat mass while hematocrit is proportional to both fat-free mass and abdominal adiposity, but which parts of these body components are involved in this relationship is not known. Segmental bioelectrical impedance analysis (sBIA) provides a possibility to delineate the relationships more precisely between various subdivisions of the body and blood viscosity factors, going farther than preceding studies using non segmental BIA. In this study we investigated in 38 subjects undergoing a standardized breakfast test with mathematical modelling of glucose homeostasis and a segmental bioelectrical impedance analysis (sBIA) the relationships between the various compartments of the body and viscosity factors. Blood and plasma viscosity were measured with the Anton Paar rheometer and analyzed with Quemada's model. The parameters better correlated to hematocrit are fat free mass (r = 0.562) and its two components muscle mass (r = 0.516) and non-muscular fat-free mass (r = 0.452), and also trunk fat mass (r = 0.383) and waist-to hip ratio (r = 0.394). Red cell aggregation measurements were correlated with both truncal and appendicular fat mass (r ranging between 0.603 and 0.728). Weaker correlations of M and M1 are found with waist circumference and hip circumference. This study shows that the correlation between lean mass and hematocrit involves both muscle and non-muscle moieties of lean mass, and that both central and appendicular fat are determinants of red cell aggregation.

Muscle quality improvement in subacute post-stroke patients after rehabilitation: Usefulness of segmental phase angle from bioelectrical impedance analysis

During stroke rehabilitation, the whole-body Phase Angle (PhA) from Bioelectrical Impedance Analysis (BIA) is measured to assess whole-body muscle quality, which reflects cellular integrity and function. The segmental BIA is a valuable method for assessing the body composition of specific body segments, such as the arms, legs, and hemisoma. After a stroke insult, patients frequently experience hemiparesis, and segmental PhA from segmental BIA appears to be an appropriate parameter for examining the muscle quality of affected and unaffected limbs separately. This study aims to investigate whether segmental PhA is more informative than whole-body PhA in (a) assessing the deterioration of muscle quality in post-stroke patients and (b) monitoring its recovery following rehabilitative treatment. This longitudinal study recruited subacute post-stroke patients who were admitted to our rehabilitation center. At admission, demographic, anamnestic, and clinical information, such as the presence of comorbidities, were recorded. BIA was used to evaluate the whole-body PhA and segmental PhA of the affected and unaffected hemisoma, arms, and legs at admission (T0) and after a six-week rehabilitation program (T1). The modified Barthel Index (mBI), Fugl-Meyer Assessment for the Upper Extremity (FMA-UE), and Motricity Index of the Upper (MI-UE) and Lower (MI-LE) Extremities were evaluated at T0 and T1 to determine the patient's Activity of Daily Living (ADL) performance, upper limb motor performance, and upper and lower limb muscle strength, respectively. We evaluated segmental and whole-body BIA in 70 subacute post-stroke patients (women n=34, ischemic n=56, mean age 70±11) at T0 and T1. Whole-body PhA values of the patients were below the normal range. Considering segmental data, the affected hemisoma, arm, and leg had considerably lower PhA values as compared to the unaffected body segments. Furthermore, at T1, the PhA values of all affected body segments improved, while those of the unaffected ones and whole-body PhA did not. At both T0 and T1, the segmental PhA values of the affected body segments showed to be related with all clinical outcome measures, while whole-body PhA correlated only with mBI. This study emphasizes the significance of measuring segmental PhA in hemiparetic subacute stroke patients undergoing rehabilitation treatment. Segmental PhA is a more accurate parameter to evaluate rehabilitation treatment in patients with hemiparesis because it can distinguish affected from unaffected body segments, hence facilitating accurate monitoring of muscle quality improvements resulting from a rehabilitation program.

Skeletal muscle quality, measured via phase angle, and cardiorespiratory fitness in patients with obesity and heart failure with preserved ejection fraction

ObjectivesCardiorespiratory fitness (CRF) is influenced by body composition quantity and quality in heart failure with preserved ejection fraction (HFpEF) and obesity. Bioelectrical impedance analysis (BIA) provides a noninvasive quantitative and qualitative body composition assessment. The aim of this study was to determine the role of phase angle (PhA), a BIA-measure of skeletal muscle quality and body cell mass, on CRF in patients with obesity and HFpEF. MethodsFifty-nine consecutive outpatients with HFpEF underwent cardiopulmonary exercise testing to measure CRF. Single-frequency segmental BIA was used to measure PhA and body composition quantity. Resting Doppler echocardiography and biomarkers were measured to assess cardiac function and systemic inflammation. ResultsCompared with patients with lower PhA, patients with higher PhA (above mean 5.8°) presented a greater absolute peak oxygen consumption (VO2; 1.83 [1.3–2.1] versus 1.39 [1.1–1.6] L/min, P = 0.003), VO2 peak adjusted for body weight (17.5 [12.3–18.1] versus 13.3 [12.7–15.2] mL/kg/min, P = 0.040), and a lower edema index (48.7 [2.9] versus 51.4% [2.7], P < 0.001) and N-terminal pro-B-type natriuretic peptide (NT-proBNP; 64 [50–121] versus 183 [68–343.5] pg/dL, P < 0.001). In the overall sample, PhA was correlated with absolute VO2 peak (r = 0.468, P < 0.001), VO2 peak adjusted for body weight (r = 0.368, P = 0.004), VO2 peak adjusted for fat-free mass (r = 0.315, P = 0.015), edema index (r = –0.508, P < 0.001), and NT-proBNP (r = –0.579, P < 0.001). PhA remained a significant predictor for CRF even after adjustment for potential confounders and HFpEF severity. ConclusionIn patients with obesity and HFpEF, a greater PhA is an independent predictor for favorable CRF.

Phase angle as a key marker of muscular and bone quality in community-dwelling independent older adults: A cross-sectional exploratory pilot study

The aim of the present cross-sectional exploratory pilot study was to analyze the ability of the Phase Angle (PhA) to predict physical function, muscle strength and bone indicators, upon adjusting for potential confounders [age, sex, lean mass, and body mass index (BMI)]. This study included 56 physically independent older adults (age, 68.29 ± 3.01 years; BMI, 28.09 ± 4.37 kg/m2). A multi-frequency segmental bioelectrical impedance analysis was used to measure PhA at 50 KHz. Additionally, physical function was assessed through four functional capacity tests [30-sec chair‐stand; seated medicine ball throw (SMBT); timed up & go; and 6-min walking test (6 MWT)], muscle strength through the handgrip test (dominant side) and maximal isokinetic strength of the dominant knee flexor and extensor. Moreover, bone indicators and body composition were assessed through the dual energy X-ray absorptiometry.PhA was significantly associated with SMBT (r = 0.375, effect size (ES) = moderate); 6 MWT (r = 0.396, ES = moderate); 30-sec chair‐stand (rho = 0.314, ES = moderate); knee extension (rho = 0.566, ES = large) and flexion (r = 0.459, ES = moderate); handgrip (rho = 0.432, ES = moderate); whole-body bone mineral content (BMC) (r = 0.316, ES = moderate); femoral neck BMC (r = 0.469, ES = moderate); and femoral neck bone mineral density (BMD) (rho = 0.433, ES = moderate). Additionally, the results of multiple regression analysis demonstrated that PhA is significantly associated with SMBT (p < 0.001; R2 = 0.629), 6 MWT (p = 0.004; R2 = 0.214), knee extension (p < 0.001; R2 = 0.697), knee flexion (p < 0.001; R2 = 0.355), handgrip test (p < 0.001; R2 = 0.774), whole-body BMC (p < 0.001; R2 = 0.524), femoral neck BMC (p = 0.001; R2 = 0.249), and femoral neck BMD (p = 0.020; R2 = 0.153). The results of the preliminary analysis suggested that PhA is linked to muscle strength and some factors related to physical function and bone quality in community-dwelling older adults.

Abdominal Aortic Aneurysm Detection in Bioelectrical Impedance Cardiovascular Screenings-A Pilot Study.

Screening and diagnosing abdominal aortic aneurysms (AAA) are currently dependent on imaging studies such as ultrasound or computed tomography angiography. All imaging studies offer distinct advantages but also suffer from inherent limitations such as examiner dependency or ionizing radiation. Bioelectrical impedance analysis has previously been investigated with respect to its use in the detection of several cardiovascular and renal pathologies. The present pilot study assessed the feasibility of AAA detection based on bioimpedance analysis. In this single-center exploratory pilot study, measurements were conducted among three different cohorts: patients with AAA, end-stage renal disease patients without AAA, and healthy controls. The device used in the study, CombynECG, is an open-market accessible device for segmental bioelectrical impedance analysis. The data was preprocessed and used to train four different machine learning models on a randomized training sample (80% of the full dataset). Each model was then evaluated on a test set (20% of the full dataset). The total sample included 22 patients with AAA, 16 chronic kidney disease patients, and 23 healthy controls. All four models showed strong predictive performance in the test partitions. Specificity ranged from 71.4 to 100%, while sensitivity ranged from 66.7 to 100%. The best-performing model had 100% accuracy for classification when applied to the test sample. Additionally, an exploratory analysis to approximate the maximum AAA diameter was conducted. An association analysis revealed several impedance parameters that might possess predictive ability with respect to aneurysm size. AAA detection via bioelectrical impedance analysis is technically feasible and appears to be a promising technology for large-scale clinical studies and routine clinical screening assessments.

Segmental bioelectrical impedance analysis can detect differences between the affected and non-affected limbs in individuals with hip osteoarthritis

ObjectiveTo analyze the bioelectrical impedance parameters of the lower limbs of individuals with hip osteoarthritis and healthy individuals.DesignCross-sectional study.SettingThe study was carried out at the Hip Surgery Outpatient Clinic.ParticipantsThe volunteers had to be between 45 and 70 years of age, of both sexes, with a clinical and radiological diagnosis of hip osteoarthritis for at least three years, unilateral involvement, or a significant complaint in one hip.MethodsThis was a cross-sectional study. Fifty-four individuals were recruited for the study, 31 individuals with hip osteoarthritis (OA group) and 29 healthy individuals for the control group (C group). Demographic and anthropometric data were collected and then the Numerical Pain Rating Scale, WOMAC, Harris Hip Score, and bioimpedance assessment were applied.Main outcome measure(s)Electrical bioimpedance parameters. Phase angle (PhA), impedance, reactance, and muscle mass.ResultsThere was a significant difference in phase angle (PhA), impedance, and muscle mass at 50 kHz frequency on the side affected by OA when compared to the contralateral side. In the OA group, there was a significant decrease in phase angle (PhA) -0.54 (-0.85 to -0.23) and muscle mass − 0.29 (-0.40 to -0,19), as well as an increase in impedance at the 50 kHz frequency on the side affected by OA when compared to contralateral side 21.71 (13.69 to 29.74). In the C group, there was no difference between the dominant and non-dominant sides (P > 0.05).ConclusionThe segmental electrical bioimpedance equipment can detect differences between limbs affected and unaffected by hip osteoarthritis.

Handgrip strength is correlated with activities of daily living, balance, and body composition in patients with thoracolumbar compression fracture.

This study assessed the relationship between handgrip strength (HGS) and activities of daily living, balance, walking speed, calf circumference, body muscle, and body composition in elderly patients with thoracolumbar vertebral compression fracture (VCF). A cross-sectional study in a single hospital was performed with elderly patients diagnosed with VCF. After admission, we evaluated HGS, 10-meter walk test (speed), Barthel Index, Berg Balance Scale (BBS), numerical rating scale of body pain, and calf circumference. We examined skeletal muscle mass, skeletal muscle mass index, total body water (TBW), intracellular water, extracellular water (ECW), and phase angle (PhA) in patients with VCF using multi-frequency direct segmental bioelectrical impedance analysis after admission. A total of 112 patients admitted for VCF were enrolled (26 males, 86 females; mean age 83.3 years). The prevalence of sarcopenia according to the 2019 Asian Working Group for Sarcopenia guideline was 61.6%. HGS was significantly correlated with walking speed (P < .001, R = 0.485), Barthel Index (P < .001, R = 0.430), BBS (P < .001, R = 0.511), calf circumference (P < .001, R = 0.491), skeletal muscle mass index (P < .001, R = 0.629), ECW/TBW (P < .001, r = -0.498), and PhA (P < .001, R = 0.550). HGS was more strongly correlated with walking speed, Barthel Index, BBS, ECW/TBW ratio, and PhA in men than women. In patients with thoracolumbar VCF, HGS is associated with walking speed, muscle mass, activities of daily living measured using the Barthel Index, and balance measured using BBS. The findings suggest that HGS is an important indicator of activities of daily living, balance, and whole-body muscle strength. Furthermore, HGS is related to PhA and ECW/TBW.

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.

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.

A Comparison of Bioimpedance Analysis vs. Dual X-ray Absorptiometry for Body Composition Assessment in Postpartum Women and Non-Postpartum Controls.

Postpartum fat mass (FM) and fat-free mass (FFM) may be informative predictors of future disease risk among women; hence, there is growing use of bioelectrical impedance analysis (BIA) to quantify FFM and FM among postpartum women due to the quick, non-invasive, and inexpensive nature of BIA. Despite this, very few studies have examined BIA’s performance, and it remains unclear as to whether specific BIA equations are needed for postpartum women. To explore these questions, we measured total body FFM and FM with a multi-frequency, segmental BIA, and dual-X-ray absorptiometry (DXA) in (1) women at one and four months postpartum (n = 21); and (2) height- and weight-matched non-postpartum women (controls, n = 21). BIA was compared to DXA using Deming regression models, paired t-tests, and Bland–Altman plots. Between-group comparisons were performed using an analysis of variance models. The mean difference between DXA and BIA was 1.2 ± 1.7 kg FFM (p < 0.01) and −1.0 ± 1.7 kg FM (p < 0.05) in postpartum women at both time points. The measurements of longitudinal changes in FFM and FM were not significantly different between BIA and DXA. Furthermore, there was no significant difference in BIA’s performance in postpartum vs. non-postpartum women (p = 0.29), which suggests that population-specific equations are not needed for postpartum women. The results of this study suggest that BIA is a suitable method to assess postpartum body composition among women at one and four months postpartum, using existing age-, race-, and sex-adjusted equations.

Accuracy of Y-scope, a newly developed portable abdominal impedance analyzer, for the assessment of abdominal visceral fat area.

AimThis study was conducted to evaluate the accuracy of a newly developed multifrequency segmental (MFS) bioelectrical impedance analysis (BIA) method using an additional portable abdominal (PA) impedance analyzer, in the assessment of abdominal visceral fat area (VFA).Materials and methodsOne hundred healthy Korean subjects aged 19 years or over (43 men and 57 women) were recruited, and VFA was estimated by a conventional MFS-BIA machine and a new MFS-BIA machine with a PA-BIA device, indicating MFS-VFA and MFS&PA-VFA, respectively. The accuracy of the VFA values was compared with those evaluated with CT at the level of the umbilicus (CT-VFA).ResultsThe mean age was 41 years and mean body mass index (BMI) was 24.4 kg/m2. The mean ± SD VFAs measured by CT, conventional MFS-BIA, and new MFS&PA-BIA together were 93.4 ± 60.9, 92.7 ± 53.4, and 93.6 ± 55.4 cm2, respectively. Correlation coefficients comparing CT-VFA with MFS-VFA and MFS&PA-VFA were 0.612 and 0.932, respectively (P < 0.001 for both). The mean difference between CT-VFA and MFS&PA-VFA was less affected by age, sex, and BMI compared with that between CT-VFA and MFS-VFA. Intraclass correlation coefficient (95% CI) between CT-VFA and MFS&PA-VFA was also greater than that between CT-VFA and MFS-VFA, 0.96 (0.95–0.98) vs. 0.76 (0.64–0.84), respectively.ConclusionIn this study, application of a newly developed MFS-BIA machine combined with a PA-BIA device significantly improved the correlation with CT-measured VFA without proportional error. This novel approach using advanced technology may be able to provide more reliable estimates of abdominal VFA.

Reference Data of Phase Angle Using Bioelectrical Impedance Analysis in Overweight and Obese Chinese.

IntroductionPhase angle (PhA) is a ratio of reactance and resistance {arctangent (reactance (Xc)/resistance (R)) × (180°/π)}, which can be obtained by bioelectrical impedance analysis (BIA). PhA indicates cellular health and integrity, and it is also considered as a prognostic tool in medical disorders and an indicator of nutritional status (especially of muscle quality) in patients with obesity. However, PhA has limited usefulness in clinical practice because of a lackness of reference values for Chinese overweight and obese populations. The main aim of this study was to show PhA reference data in different age and BMI groups by sex. In addition, we also study the association of age, sex, and BMI on PhA.MethodsA total of 1729 overweight and obese participants were included in this study. PhA and body composition were measured using segmental multifrequency BIA. Differences in mean values for variables were tested by one-way analysis of variance. Multiple regression analysis was used to assess the associations of PhA with age, sex and BMI.ResultsMultiple regression analysis showed that age, sex and BMI were significant (P < 0.05) independent influence factors of PhA in Chinese overweight and obese adults when age and BMI were continues variables. The mean PhA value for all participants was 5.5°. Mean BMI, age, weight, height and 50kHz-PhA were significantly higher (P < 0.001) in male participants than female ones. In age groups and BMI groups, mean 50kHz-PhA was significantly higher (P < 0.005) in male participants than female ones. When age groups and BMI groups were categorical variables, multiple regression analysis showed that different age groups (46–55 years and ≥ 56 years) had a significantly lower (P < 0.005) PhA as compared with the baseline group (18-25 years) and different BMI groups (≥ 28 kg/m2) had a significantly higher (P < 0.05) PhA as compared with the baseline group (24–27.9 kg/m2).ConclusionPhA differed according to age, sex and BMI. Reference data in this study can be taken into consideration when deriving the reference values for overweight and obese Chinese populations.

Extracellular water-to-total body water ratio is an essential confounding factor in bioelectrical impedance analysis for sarcopenia diagnosis in women.

The extracellular water-to-total body water ratio (ECW/TBW) is used in bioelectrical impedance analysis (BIA) for measuring muscle mass; however, ECW/TBW may be affected by several factors common in older individuals. Here, we assessed the relationships of ECW/TBW with handgrip strength, gait speed, and skeletal muscle mass index (SMI) in older women. In this cross-sectional study, 73 community-dwelling women aged ≥ 65years who could independently perform activities of daily living were included. ECW/TBW was measured using direct segmental multifrequency BIA. The participants were divided into ECW/TBW < 0.40 (n = 54) and ECW/TBW ≥ 0.40 (n = 19) groups, with the latter indicating overhydration. SMI was calculated as appendicular skeletal muscle mass/(height)2 (kg/m2). The relationships of SMI with handgrip strength and gait speed were assessed using partial correlation coefficients. Age, number of medications, pain, and medical history were treated as control variables. The average age of participants was 77.6 ± 6.0years. The SMI was significantly related to handgrip strength (partial correlation coefficient = 0.293, P = 0.016) but not to gait speed (partial correlation coefficient = - 0.183, P = 0.138). Similarly, the SMI of the ECW/TBW < 0.40 group was significantly related to handgrip strength (partial correlation coefficient = 0.372, P = 0.009) but not gait speed (partial correlation coefficient = - 0.267, P = 0.066); however, the SMI of the ECW/TBW ≥ 0.40 group was not related to either variable. ECW/TBW represents a confounding factor, which should be considered when using BIA for sarcopenia diagnosis.

Accuracy of Estimated Bioimpedance Parameters with Octapolar Segmental Bioimpedance Analysis.

The validity of the impedance parameters of the five body segments estimated using octapolar segmental bioelectrical impedance analysis (OS-BIA) has not been confirmed. This study aimed to verify the accuracy of the resistance (R), reactance (Xc), and phase angle of each five-body segment. The accuracy of the OS-BIA at 50 kHz was measured based on the direct tetrapolar segmental BIA. The differences in the estimated impedance parameters of the five body segments were compared to those measured from the OS-BIA in elderly men (N = 73) and women (N = 63). The estimated 50 kHz-R (Ω) was significantly higher than the measured 50 kHz-R in the right and left arms, and lower than the measured 50 kHz-R of the trunk, right leg, and left leg (all, p < 0.05). The estimated 50 kHz-phase angles in all the five body segments were significantly lower than the measured ones (all, p < 0.05). The findings suggest that the estimated impedance parameters, R, Xc, and phase angle of the trunk, were remarkedly underestimated, limiting the assessment of the physiological state of the organs in the body. Therefore, further intensive research is needed in the field of estimated segmental BIA in the future.

Body composition and chemotherapy toxicity in women with early breast cancer (CANDO-3): protocol for an observational cohort study

IntroductionSystemic anticancer therapy is given to selected patients with early breast cancer (EBC) before or after surgery with the aim of eradicating micrometastatic spread and reducing the risk of cancer...

P274 Bioelectrical impedance analysis identifies low skeletal muscle index in patients with Inflammatory Bowel Disease

Abstract Background Low skeletal muscle index (SMI) has been associated with increased need for surgery and post-surgical complications in patients with Inflammatory Bowel Disease (IBD). On dual energy X-ray absorptiometry (DXA), SMI is routinely calculated by dividing limb skeletal muscle mass (kg) by the square of the height (m2). Bioelectrical impedance analysis (BIA) provides a quick, inexpensive and radiation-free method to measure body composition. The aim of this study was to compare BIA with DXA to identify patients with low skeletal muscle mass and to show change over 14 weeks. Methods This single-centre prospective study recruited adult patients with IBD and adult controls, matched for gender. Active disease was defined as a faecal calprotectin of ≥150 μg/g. Active IBD patients undergoing biologic induction had repeat body composition measurements at least 14 weeks apart. All patients underwent single-frequency segmental BIA (Tanita BC-418) and DXA (GE Lunar Prodigy). A BIA-predicted SMI was calculated by dividing limb fat-free mass (kg) by the square of the height (m2). Results Of 48 patients with IBD, 54% had Crohn’s disease, 56% were male and median age was 29 (IQR 23–40) years. 28 had active disease, 16 inactive disease and 4 had no faecal calprotectin available. Patients with IBD and controls (n=30) had similar total body water, measured by BIA, and differed in albumin levels (39 vs 40.1 g/L, p=0.011). In IBD patients and controls, BIA total fat-free mass correlated strongly with DXA-derived fat-free mass (0.96 and 0.93, both p&amp;lt;0.0001). The BIA-predicted SMI also correlated well with DXA-derived SMI (0.89 and 0.91, both p&amp;lt;0.0001). The correlation was stronger for Ulcerative Colitis (0.96) compared to Crohn’s disease (0.84). In patients with IBD, the mean difference between BIA-predicted SMI and DXA-derived SMI was 1.1 ± 0.6 kg/m2 with 95% limits of agreement, -0.1 to 2.3 kg/m2. Controls followed a similar trend with a mean difference of 0.5 ± 0.6 kg/m2 and 95% limits of agreement, -0.5 to 1.6 kg/m2. The BIA-predicted SMI demonstrated a strong ability to identify low DXA-derived SMI for women with IBD (AUC: 0.98) and less so for men (AUC: 0.79). In 14 patients undergoing biologic treatment, change in DXA-derived SMI correlated with BIA-derived SMI (0.76, p=0.003). Conclusion An accurate estimate of SMI can be obtained with BIA as point-of-care in clinical practice. Further prospective studies with larger sample sizes are needed to determine the accuracy of BIA in monitoring changes of SMI during IBD treatment.

Comparison between whole-body and segmental bioelectrical impedance for body composition

Rationale: Chronic kidney disease patients have an altered and negative body composition associated with higher mortality risk. Bioelectrical impedance analysis (BIA) is an available method to evaluated body composition. This study aimed to compare data from whole-body wrist-to-ankle BIA (WBBIA) and segmental BIA (SEGBIA) applied in subjects with chronic kidney disease.

Effects of Urination, Aerobic Exercise, Food and Water Ingestion on Body Composition Measured by Segmental Bioelectrical Impedance Analysis

PURPOSE: Body composition is strongly associated with cardiometabolic risk factors, and accurate measurement of body composition is vital for the management of chronic diseases. In this study, we assessed whether major factors such as urination, aerobic exercise, food, and water consumption had significant effects on body composition by segmental bioelectrical impedance analysis (BIA).METHODS: To achieve the goal of this study, research was conducted on 32 healthy young males (n=18) and females (n=14). All participants underwent body composition analysis in four different conditions (both pre- and post-urination, moderate-intensity aerobic exercise for 30 minutes, immediately after food and water consumption, 30, 60, and 120 minutes after each treatment), and segmental BIA was performed using Inbody720.RESULTS: We found that after urination, body weight, skeletal muscle mass, and basal metabolic rate (BMR) significantly decreased. However, water intake significantly increased body weight, body fat mass, and body fat percentage. Furthermore, an acute 30-minutes aerobic exercise significantly decreased body weight, fat mass, and fat percentage, and increased skeletal muscle mass and BMR. In addition, impedance decreased immediately and increased 120 minutes after the acute aerobic exercise. Finally, food ingestion significantly increased the body weight, skeletal muscle mass, and BMR.CONCLUSIONS: Our study suggests that variables such as urination, exercise, food consumption, and water intake should be considered to accurately assess body composition.

Changes in total and segmental extracellular and intracellular volumes with hypotension during hemodialysis measured with bioimpedance spectroscopy.

Bioelectrical impedance analysis (BIA) devices have been advocated to guide volume management in hemodialysis (HD) patients. We hypothesized that understanding the dynamics of fluid shifts in different body segments may provide additional insight on preventive measures to reduce the risk of intradialytic hypotension. A prospective observational study was conducted among 42 HD patients at risk of hypotension who were admitted as emergencies inpatient. A total of 191 BIA measurements were made during the 42 HD sessions, and hypotension occurred during 52 measurements (27%). The extracellular water (ECW) to intracellular water ratio (EIR) was measured in different body segments and declined significantly only in the non-access arm with increasing HD session duration (β=-0.04; 95% confidence interval (CI): -0.05 to -0.03, p<0.01). There was no significant association between EIR and hypotension with respect to the different body segments. Only pre-HD N-terminal-pro b-type natriuretic peptide was significantly associated with hypotension (β=0.20, 95% CI: 0.04 to 0.89, p=0.04). There was no association between relative blood volume monitoring change and EIR. In summary, we found that segmental BIA during HD was unable to detect or predict hypotension during dialysis. Although BIA is able to provide information about ECW and guide clinical assessment of volume in HD patients prior to dialysis, our findings did not suggest the use of serial measurements of changes in EIR in different body segments during HD provided sufficient information to predict intradialytic hypotension. Similarly, changes in EIR did not provide information on changes in plasma volume that could potentially trigger interventions to prevent or reduce intra-dialytic hypotension.

Body Fat Distribution and Risk of Breast, Endometrial, and Ovarian Cancer: A Two-Sample Mendelian Randomization Study.

Simple SummaryThe causal impact of body fat distribution on female-specific cancers is largely unknown. For the first time we used a two-sample multivariable Mendelian randomization (MR) approach to elucidate the role and causal relations of body composition assessed by segmental bioelectrical impedance analysis on the risks of breast, endometrial and ovarian cancers and their subtypes. We found that abdominal fat content increases the risk for ovarian cancer and its endometrioid and clear cell subtypes independent of overall fat content. General adiposity has a protective effect on risk of breast cancer and its ER- and ER+ subtypes but increases the risk for endometrial cancer, ovarian cancer, and the endometrioid ovarian cancer subtype. This study extends the literature by addressing specifically the causal role of visceral fat on female-specific cancers.Background: Mounting evidence shows that adiposity increases female-specific cancer risk, but the role of body fat distribution is less clear. We used a two-sample Mendelian randomization (MR) approach to elucidate causal relations of body fat distribution to the risks of breast, endometrial and ovarian cancers and their subtypes. Methods: Body composition was assessed using segmental bioelectrical impedance analysis, yielding trunk, arm, and leg fat ratios (TFR, AFR, LFR) and BMI including 195,043 and 434,794 European women, respectively. The sample sizes for the outcomes ranged between 58,396 and 228,951. Causal effects were estimated per one standard deviation increment in the respective exposure within the radial regression framework. Robust sensitivity analyses were performed to verify MR assumptions. In a multivariable MR setting, the proportion of risk attributable to overall and abdominal fat content was assessed. Results: TFR, which represents abdominal fat content, was associated with ovarian cancer and its clear cell and endometrioid histotypes independent of overall fat content. BMI was inversely associated with breast cancer and its ER− and ER+ subtypes, but positively with endometrial cancer and ovarian cancer, including its endometrioid histotype. These estimates were confirmed using AFR as proxy for overall body fat. Conclusions: Visceral adiposity seems to be a driver of elevated ovarian cancer risk, particularly of the endometrioid and clear cell ovarian cancer histotypes. General adiposity decreases the risk of breast cancer but increases the risk of endometrial and ovarian cancer.