Whole-body Bioelectrical Impedance Analysis Research Articles

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.

Usefulness of the skeletal muscle index in postoperative ileus of colorectal cancer patients: a retrospective cohort study

BackgroundPostoperative complications of colorectal cancer mainly include infections (surgical site infection, remote infection, etc.), post-operative ileus (POI), and anastomosis leakage. POI reportedly prolongs the hospital stay and increases medical costs. Therefore, predicting POI is very important. There have been some reports on the relationships between sarcopenia and postoperative complications in colorectal cancer patients, but none have been limited to POI. We therefore conducted a retrospective clinical study with a logistic regression analysis to confirm the risk factors for ileus after colorectal cancer surgery.MethodsWe retrospectively analyzed 213 patients who underwent elective oncological colorectal surgery for colorectal cancer from November 2017 to July 2021. The skeletal muscle mass (SMM, kg) was estimated using a whole-body bioelectrical impedance analysis (BIA), and the skeletal muscle index (SMI) was calculated as the SMM/height2. We divided all patients into 2 groups based on a low SMI (male < 8.958 kg/m2, female < 8.443 kg/m2) or normal SMI. Preoperative and intraoperative factors as well as, postoperative outcomes were then compared between the two groups.ResultsThe median (range) age of the 213 included patients was 72.0 (33–91) years old. Complications were noted in 96 patients (45.1%), including 21 (9.9%) with POI. There were 68 (31.9%) low SMI patients. POI occurred significantly more frequently in low SMI patients (19.1%) than in normal SMI patients (5.5%) (p = 0.005). In the multivariate analysis, bleeding (p = 0.039) and a low SMI (p = 0.031) were significantly associated with POI. In addition, a propensity score matching analysis was performed to further reduce the selection bias. As a result, a low SMI was the only independent POI predictor among the 78 matched cases.ConclusionA preoperative low SMI in colorectal cancer patients was considered a risk factor for POI.

Association of Birth Weight, Body Composition and Blood Pressure During Infancy in 1-Year-Old Jamaican Children

ObjectivesTo investigate the association of birth weight (BW), body composition (BC), and blood pressure (BP) in healthy, one-year-old infants in Jamaica.MethodsA cross-sectional study where fat-free mass (FFM) and fat mass (FM) was assessed by whole-body bioelectrical impedance analysis (BIA) and skinfold thickness measurements in a sample of 101 healthy one-year-old infants (58 girls and 43 boys). Oscillometric Blood Pressure was measured in triplicate in each infant. The main independent variable was birth weight. Pearson's correlation test and multiple linear regression were used to analyze the association between birth weight and body composition and blood pressure..ResultsSignificant associations were observed between birth weight and fat-free mass(r = 0.35.p = 0.0001) and fat mass(r = 0.25.p = 0.013) at the simple bivariate level, weight, and length significantly correlated with body composition using the multiple linear regression. 12% of girls and 265 of boys had excess body fat. The mean BP was 110/67 mm Hg for boys and 108/67 mm Hg for girls. At the bivariate level, birth weight was significantly correlated with systolic blood pressure (r = 0.21, p = 0.019). There was no association between birth weight and blood pressure in the regression models. Socioeconomic status did not impact the association of birth weight and body composition in this study. Significant associations were observed between birth weight and fat-free mass(r = 0.35.p = 0.0001) and fat mass(r = 0.25.p = 0.013) at the simple bivariate level, weight, and length significantly correlated with body composition using the multiple linear regression. 12% of girls and 265 of boys had excess body fat. The mean BP was 110/67 mm Hg for boys and 108/67 mm Hg for girls. At the bivariate level, birth weight was significantly correlated with systolic blood pressure (r = 0.21, p = 0.019). There was no association between birth weight and blood pressure in the regression models. Socioeconomic status did not impact the association of birth weight and body composition in this study.ConclusionsIn this sample of one-year-old infants, birth weight was associated with fat-free mass and fat mass, and weight and length were associated with fat-free mass, fat mass, and percentage body fat.Funding SourcesThis research was not funded.

Prognostic value of bioelectrical impedance analysis for assessment of fluid overload in ICU patients: apilot study.

The non-invasive analysis of body fluid composition with bio-electrical impedance analysis (BIA) provides additional information allowing for more persona-lised therapy to improve outcomes. The aim of this study is to assess the prognostic value of fluid overload (FO) in the first week of intensive care unit (ICU) stay. Aretrospective, observational analysis of 101 ICU patients. Whole-body BIA measurements were performed, and FO was defined as a5% increase in volume excess from baseline body weight. Baseline demographic data, including severity scores, were similar in both the fluid overload-positive (FO+, n = 49) patients and in patients without fluid overload (FO-, n = 52). Patients with FO+ had significantly higher cumulative fluid balance during their ICU stay compared to those without FO (8.8 ± 7.0 vs. 5.5 ± 5.4 litres; P = 0.009), VE (9.9 ± 6.5 vs. 1.5 ± 1.5 litres; P < 0.001), total body water (63.0 ± 9.5 vs. 52.8 ± 8.1%; P < 0.001), and extracellular water (27.0 ± 7.3 vs. 19.6 ± 3.7 litres; P < 0.001). The presence of 5%, 7.5%, and 10% fluid overload was directly associated with increased ICU mortality rates. The percentage fluid overload (P = 0.039) was an independent predictor for hospital mortality. Ahigher mortality rate in ICU-patients with FO was observed. FO is an independent prognostic factor because neither APACHE-II, SOFA, nor SAPS-II significantly differed on admission between survivors and non-survivors. Further research is needed to confirm these data prospectively and to evaluate whether BIA-guided deresuscitation in the subacute phase will improve mortality rates.

Association of handgrip strength and endurance with body composition in head and neck cancer patients.

Introduction:Assessment of skeletal muscle function (SMF) is of clinical relevance in the prediction of treatment outcome and to decide on optimal management of head & neck cancer (HNC) patients. Handgrip strength (HGS) & handgrip endurance (HGE) are considered as surrogate marker for whole-body skeletal muscle function. Further, SMF depends substantially on the body composition (BC). Hence in this study, we compared BC, HGS and HGE between HNC patients and healthy controls and also analysed the association of HGS, HGE with body composition in HNC patients.Methods:A cross-sectional study, conducted in 44 subjects in the age between 18 to 60 years. Twenty-two were histologically proven HNC patients prior to cancer-specific treatment and twenty-two age and gender-matched healthy volunteers. The parameters recorded were Height, weight, waist circumference, hip circumference, HGS, HGE and BC. Hand-held dynamometer was used to measure HGS and HGE measured using a stopwatch. BC was estimated by whole-body bioelectrical Impedance analysis method using Bodystat Quad scan 4000 device.Result:Comparison of data between HNC patient & healthy control was done by Student's t test. HGS, HGE, lean body mass (LBM), fat-free mass index (FFMI), Phase angle (PA), body cell mass (BCM) and body cell mass index (BCMI) were found to be reduced significantly in HNC patients when compared to healthy subjects. Further, Pearson correlation analysis revealed a significant positive correlation of HGS & HGE with LBM, FFMI, PA, BCM & BCMI, whereas body fat mass index showed a negative correlation with HGS & HGE in HNC patients.Conclusion:Our findings revealed, a significant reduction in HGS, HGE in patient with HNC which denotes decreased skeletal muscle function and it is linearly associated with low muscle mass, body cell mass and phase angle.

Use of bioelectrical impedance analysis to monitor changes in fat-free mass during recovery from colorectal cancer– a validation study

Although previous research show high correlation between fat-free mass (FFM) measured by bioelectrical impedance analysis (BIA) and dual-energy X-ray absorptiometry (DXA), the validity of BIA to track longitudinal changes in FFM is uncertain. Thus, the aim of this study was to validate the ability of BIA to assess changes in FFM during 6 months of recovery from non-metastatic colorectal cancer (CRC). A total of 136 women and men (50-80 years) with stage I-III CRC and a wide range of baseline FFM (35.7-73.5kg) were included in the study. Body composition was measured at study baseline within 2-9 months of surgery and again 6 months later. Whole-body BIA FFM estimates (FFMBIA) were calculated using three different equations (manufacturer's, Schols' and Gray's) before comparison to FFM estimates obtained by DXA (FFMDXA). Correlation between changes in FFMBIA and FFMDXA was intermediate regardless of equation (r≈0.6). The difference in change of FFMBIA was significant compared to FFMDXA, using all three equations and BIA overestimated both loss and gain. However, BIA showed 100% sensitivity and about 90% specificity to identify individuals with ≥5% loss in FFM, using all three equations. Sensitivity of FFMBIA to detect a smaller loss of FFM (60-76%) or a gain in FFM of ≥5% (33-62%) was poor. In a well-nourished population of non-metastatic CRC patients, a single-frequency whole-body BIA device yielded imprecise data on changes in FFM, regardless of equation. BIA is thus not a valid option for quantifying changes in FFM in individuals. However, BIA could be used to identify patients with loss in FFM ≥5% in this population. The validity of BIA to monitor changes in FFM warrants further investigation before implementation in clinical praxis.

The accuracy of commercially available upper and lower body bioelectrical impedance analyzers in men and women

Objective: The purpose of this study was to determine if upper body (UB) and lower body (LB) bioelectrical impedance analysis (BIA) devices yield similar estimates of BF% as whole body (WB) BIA. Approach: Ninety-four men and women had their body composition evaluated using a Baseline 12-1190 Body Fat Scale (Fabrication Enterprises Inc.) as the LB BIA device, an Omron HBF-306C Handheld Body Fat Loss Monitor (Omron Healthcare, Inc.) as the UB BIA device, and a Seca Medical Body Composition Analyzer 514 (Seca North America) as the WB BIA device as well as via air displacement plethysmography (ADP; BodPod; Life Measurement Inc.). Main results: in women, the BF% was greater for WB BIA compared to UB BIA and LB BIA (28.9 ± 5.0 versus 23.8 ± 4.4 versus 20.4 ± 5.9%; p < 0.001) with no differences between the WB BIA and ADP BF% (28.9 ± 5.0 versus 28.3 ± 7.5%; p = 0.982). In men, BF% was greater for WB BIA compared to UB BIA and LB BIA (19.1 ± 6.7 versus 15.5 ± 5.3 versus 14.9 ± 4.0; p < 0.001) with no differences between the WB BIA and ADP BF% (19.1 ± 6.7 versus 17.6 ± 7.8; p = 0.394). Significance: Our findings suggest that the UB and LB BIA devices used in this study underestimate BF% compared to a WB BIA device and ADP in men and women.

Development of a Segmental Bioelectrical Impedance Spectroscopy Device for Body Composition Measurement.

Whole-body bioelectrical impedance analysis for measuring body composition has been well-explored but may not be sensitive enough to changes in the trunk compared to changes in the limbs. Measuring individual body segments can address this issue. A segmental bioelectrical impedance spectroscopy device (SBISD) was designed for body composition measurement and a prototype was implemented. Compensation was performed to adjust the measured values to correct for a phase difference at high frequencies and to counteract the hook effect when measuring the human body. The SBISD was used to measure five subjects and was compared against three existing analyzers. For most segmental measurements, the SBISD was within 10% of the R0 and R∞ values determined with a Bodystat Multiscan 5000 and an Impedimed SFB7. The impedance values from the third reference device, a Seca 514, differed significantly due to its eight-electrode measuring technique, meaning impedance measurements could not be compared directly.

Validity of bioelectrical impedance analysis in estimation of fat-free mass in colorectal cancer patients

Bioelectrical impedance analysis (BIA) is an accessible and cheap method to measure fat-free mass (FFM). However, BIA estimates are subject to uncertainty in patient populations with altered body composition and hydration. The aim of the current study was to validate a whole-body and a segmental BIA device against dual-energy X-ray absorptiometry (DXA) in colorectal cancer (CRC) patients, and to investigate the ability of different empiric equations for BIA to predict DXA FFM (FFMDXA). Forty-three non-metastatic CRC patients (aged 50-80 years) were enrolled in this study. Whole-body and segmental BIA FFM estimates (FFMwhole-bodyBIA, FFMsegmentalBIA) were calculated using 14 empiric equations, including the equations from the manufacturers, before comparison to FFMDXA estimates. Strong linear relationships were observed between FFMBIA and FFMDXA estimates for all equations (R2=0.94-0.98 for both devices). However, there were large discrepancies in FFM estimates depending on the equations used with mean differences in the ranges-6.5-6.8kg and-11.0-3.4kg for whole-body and segmental BIA, respectively. For whole-body BIA, 77% of BIA derived FFM estimates were significantly different from FFMDXA, whereas for segmental BIA, 85% were significantly different. For whole-body BIA, the Schols* equation gave the highest agreement with FFMDXA with mean difference ±SD of-0.16±1.94kg (p=0.582). The manufacturer's equation gave a small overestimation of FFM with 1.46±2.16kg (p<0.001) with a tendency towards proportional bias (r=0.28, p=0.066). For segmental BIA, the Heitmann* equation gave the highest agreement with FFMDXA (0.17±1.83kg (p=0.546)). Using the manufacturer's equation, no difference in FFM estimates was observed (-0.34±2.06kg (p=0.292)), however, a clear proportional bias was detected (r=0.69, p<0.001). Both devices demonstrated acceptable ability to detect low FFM compared to DXA using the optimal equation. In a population of non-metastatic CRC patients, mostly consisting of Caucasian adults and with a wide range of body composition measures, both the whole-body BIA and segmental BIA device provide FFM estimates that are comparable to FFMDXA on a group level when the appropriate equations are applied. At the individual level (i.e. in clinical practice) BIA may be a valuable tool to identify patients with low FFM as part of a malnutrition diagnosis.

Comparison between two methods of bioelectrical impedance analyses for accuracy in measuring abdominal visceral fat area

ObjectivesTo compare the accuracy of abdominal visceral fat area (VFA) measurements between abdominal dual bioelectrical impedance analysis (BIA) and whole-body BIA referenced to computed tomography (CT) measures. MethodsAbdominal VFAs were measured in 102 individuals: 59 men and 43 women with a mean age of 44.2±16.3years (range 21 – 76), body mass index 23.9±7.8kg/m2 (range 18 – 35) using a DUALSCAN HDS-2000 machine (dual abdominal BIA) and an InBody720 machine (whole-body BIA). The VFA values from each machine were compared with those from CT under various conditions. ResultsMean abdominal VFAs were 116±69cm2 by CT, 89±47cm2 by dual abdominal BIA, and 84±33cm2 by whole-body BIA. The former measure showed a higher correlation with the CT measure than the latter (r=0.89 vs. r=0.64, P<0.001). Both BIA methods tended to underestimate abdominal VFAs compared with CT scans when CT VFA was not small. The dual abdominal BIA had less bias than the whole-body BIA in the assessment of VFAs. The whole-body BIA was affected by subcutaneous fat area. ConclusionsDual BIA was more accurate in assessing abdominal VFA than whole-body BIA.

Evaluation of serum myostatin and sclerostin levels in chronic spinal cord injured patients.

Case-control study. To assess serum myostatin levels, bone mineral density (BMD), appendicular skeletal muscle mass (ASMM) and serum sclerostin levels in chronic spinal cord injured (SCI) patients and healthy controls. SCI centre in Italy. Blood samples, whole-body bioelectrical impedance analysis and BMD measurement with the ultrasound technique at the calcaneus level were taken from patients suffering from chronic SCI (both motor complete and incomplete) and healthy control subjects. A total of 28 SCI patients and 15 healthy controls were enrolled. Serum myostatin levels were statistically higher (P<0.01) in SCI patients compared with healthy controls. Similar results were found comparing both the motor complete and the motor incomplete SCI subgroups to healthy controls. Serum sclerostin was significantly higher in patients with SCI compared with healthy controls (P<0.01). BMD, stiffness and mean T-score values in SCI patients were significantly lower than those in healthy controls. Serum myostatin concentrations in the motor complete SCI subgroups correlated only with serum sclerostin levels (r(2)=0.42; P=0.001) and ASMM (r(2)=0.70; P=0.002) but not in healthy controls. Serum myostatin and serum sclerostin are significantly higher in chronic SCI patients compared with healthy controls. They are potential biomarkers of muscle and bone modifications after SCI. This is the first study reporting an increase in serum myostatin in patients suffering from chronic SCI and a correlation with ASMM.

Assessing appendicular skeletal muscle mass with bioelectrical impedance analysis in free-living Caucasian older adults

Aging is characterized by a loss of appendicular skeletal muscle mass (ASMM) leading to physical disability and death. Bioelectrical impedance analysis (BIA) is reliable in estimating ASMM but no prediction equations are available for elderly Caucasian subjects. The aim of the study was to develop and validate an equation derived from bioelectrical impedance analysis (BIA) to predict appendicular skeletal muscle mass (ASMM) in healthy Caucasian elderly subjects, taking dual X-ray absorptiometry (DXA) as the reference method, and comparing the reliability of the new equation with another BIA-based model developed by Kyle et al. (Kyle UG, Genton L, Hans D, Pichard C, 2003). With a cross-sectional design, 296 free-living, healthy Caucasian subjects (117 men, 179 women) over 60 years of age were enrolled. Lean mass of limbs was measured with DXA to ascertain ASMM (ASMMDxA). Whole-body tetrapolar BIA was performed to measure resistance (Rz), resistance normalized for stature (RI), and reactance (Xc). The BIA multiple regression equation for predicting ASMM was developed using a double cross-validation technique. The predicted ASMM values were compared with ASMMKyle, i.e. ASMM estimates derived from the model developed by Kyle et al. (Kyle et al., 2003). Cross-validation resulted in a unique equation using the whole sample: ASMM (kg) = -3.964 + (0.227*RI) + (0.095*weight) + (1.384*sex) + (0.064*Xc) [R(2) = 0.92 and SEE = 1.14 kg]. In our sample, ASMMKyle differed significantly from the ASMMDxA (p < 0.0001), with a mean error of -0.97 ± 1.34 kg (5.1 ± 6.9%). Unlike the present BIA prediction equation, the Kyle et al. model showed a correlation between the bias and the mean of ASMMDxA and ASMMKyle (r = -0.406, p < 0.001). The new BIA equation provides a valid estimate of ASMM in older Caucasian adults.

Body composition by whole-body bioelectrical impedance and prediction of clinically relevant outcomes: overvalued or underused?

Body composition calculated using whole-body bioelectrical impedance analysis (BIA), almost invariably with height (H) and often with weight (W), can help patient management and predict clinical outcomes. This study aimed to examine the merits of this approach compared with simple anthropometry (W+H). Use was made of original data and validation studies based on reference body composition methods: water dilution, densitometry, dual-energy X-ray absorptiometry, and more robust methods. Prediction of clinical outcomes, including mortality and length of hospital stay, was examined in six studies of chronic obstructive pulmonary disease and a study with multiple patient groups. Vector analysis, phase angle, multi-frequency BIA and segmental impedance were not considered. In a broad range of study populations, from neonates to older people, in health and disease, body composition calculated using BIA with simple anthropometry frequently offered no advantage over W+H alone, but in some situations it was superior and in others inferior. In predicting clinically relevant outcomes, the fat-free mass index (FFMI), established using BIA, had comparable and sometimes greater power than body mass index (BMI), but none of the reviewed papers used FFMI calculated from W+H or BMI to predict clinical outcomes. A variable and generally weak evidence base was found to suggest that BIA with anthropometry is better at predicting body composition than simple anthropometry alone. No evidence was found from the reviewed studies that FFMI calculated from BIA and anthropometry was better at predicting clinical outcomes than FFMI calculated by simple anthropometry alone.

Relationship between Long Sleep Duration and Functional Capacities in Postmenopausal Women

The purpose of the present study was to examine the relationship between long sleep duration and functional capacities. We conducted a cross-sectional study at the Department of Kinanthropology at the University of Quebec at Montreal. Forty eight non-frail postmenopausal women aged between 49 to 75 years were recruited using advertisements in local papers. Body weight, body mass index, fat mass, skeletal muscle mass, number of steps per day, SF-36 total (healthy questionnaire), resting metabolic rate, total energy intake, sleep duration, knee extensor strength (dynamometer), chair stand test and balance opened eyes test were measured. WE FOUND A SIGNIFICANT NEGATIVE CORRELATION BETWEEN HOURS OF SLEEP AND FUNCTIONAL CAPACITY: chair stand test (r = -0.33, p = 0.02), balance opened eyes test (r = -0.45, p = 0.001), muscle strength (r = -0.43, p = 0.002) and skeletal muscle mass (r = -0.39, p = 0.007). In addition, long sleepers (> 9 h) had significantly lower values for skeletal muscle mass (p = 0.03), muscle strength (p = 0.01), chair stand test (p = 0.03), and balance opened eyes test (p = 0.001). Finally, linear regression analysis showed that sleep duration was an independent predictor of the chair stand test (p = 0.024), balance opened eyes test (p = 0.001), and muscle strength (p = 0.035) in our cohort. Long sleepers were associated with lower functional capacities in our cohort of sedentary postmenopausal women.

Randomized trial of bioelectrical impedance analysis versus clinical criteria for guiding ultrafiltration in hemodialysis patients: effects on blood pressure, hydration status, and arterial stiffness

Chronic fluid overload is common in maintenance hemodialysis (HD) patients and is associated with severe cardiovascular complications, such as arterial hypertension, left ventricular hypertrophy, congestive heart failure, and arrhythmia. Therefore, a crucial target of HD is to achieve the so-called dry weight; however, the best way to assess fluid status and dry weight is still unclear. Dry weight is currently determined in most dialysis units on a clinical basis, and it is commonly defined as the lowest body weight a patient can tolerate without developing intra-dialytic or inter-dialytic hypotension or other symptoms of dehydration. One of the most promising methods that have emerged in recent years is bioelectrical impedance analysis (BIA), which estimates body composition, including hydration status, by measuring the body's resistance and reactance to electrical current. Our objective was to study the effect BIA-guided versus clinical-guided ultrafiltration on various cardiovascular disease risk factors and markers in HD patients. We included 135 HD patients from a single center in a prospective study, aiming to compare the long-term (12 months) effect of BIA-based versus clinical-based assessment of dry weight on blood pressure (BP), pulse wave velocity (PWV), and serum N-terminal fragment of B-type natriuretic peptide (NT-proBNP). The body composition was measured using the portable whole-body multifrequency BIA device, Body Composition Monitor-BCM(®) (Fresenius Medical Care, Bad Homburg, Germany). In the "clinical" group there were no changes in BP, body mass index (BMI), and body fluids. The PWV increased from 7.9 ± 2.5 to 9.2 ± 3.6 m/s (P = 0.002), whereas serum NT-proBNP decreased from 5,238 to 3,883 pg/ml (P = 0.05). In the "BIA" group, BMI and body volumes also did not change; however, there was a significant decrease in both systolic BP, from 144.6 ± 14.7 to 135.3 ± 17.8 mmHg (P < 0.001), and diastolic BP, from 79.5 ± 9.7 to 73.2 ± 11.1 mmHg (P < 0.001). In this group, PWV also decreased from 8.2 ± 2.3 to 6.9 ± 2.3 m/s (P = 0.001) and NT-proBNP decreased from 7,552 to 4,561 pg/ml (P = 0.001). BIA is not inferior and possibly even better than clinical criteria for assessing dry weight and guiding ultrafiltration in HD patients.

Changes in Estimating Echocardiography Pulmonary Capillary Wedge Pressure After Hypersaline Plus Furosemide Versus Furosemide Alone in Decompensated Heart Failure

Background The aim of the study was to verify the effects of hypertonic saline solution (HSS) plus a high furosemide dose and light restriction of sodium intake compared with a high-dose infusion of furosemide alone on pulmonary capillary wedge pressure (PCWP), as determined by Doppler echocardiography and tissue Doppler imaging in patients suffering from decompensated heart failure. Methods and Results Consecutive patients in New York Heart Association functional class IV, unresponsive to oral high doses of furosemide up to 250–500 mg/d and/or combinations of diuretics, with ejection fraction <40%, serum creatinine <2 mg/dL, blood urea nitrogen ≤60 mg/dL, reduced urinary volume (<500 mL/24 h), and low natriuresis (<60 mEq/24 h) were randomized into 2 groups (double blind). The first group received a furosemide infusion (250 mg) plus HSS (150 mL 3.0% Na) bid and light Na restriction (120 mmol), and the second group received furosemide infusion (250 mg) twice daily, and low Na diet (80 mmol). The fluid intake of both groups was restricted (1 L/d). Body weight, whole-body bioelectrical impedance analysis (BIA), 24-hour urinary volume, and serum and urinary laboratory parameters were measured daily. Estimations of echocardiographic PCWP (Echo-PCWP) were detected on entry, 1 hour after concluding the initial treatment, and 6 days thereafter. A total of 133 patients (47 women and 86 men), aged 65–82 years, met the entry criteria.The HSS group revealed a significant increase in daily diuresis, natriuresis, and serum sodium compared with the furosemide group. Six days after treatment, renal function was significantly improved in the HSS group. Both groups showed a significant reduction in Echo-PCWP, but the HHS group revealed a faster reduction and significant lower values at 6 days compared with the group taking furosemide alone. We observed a positive correlation between values of Echo-PCWP and BNP and an inverse correlation between BIA parameters and Echo-PCWP. Conclusions Our data show that the combination of high diuretic dose and HSS infusion plus light restriction in dietary sodium intake determine a more rapid and significant hemodynamic stabilization through the improvement of echo-PCWP, BNP levels, and BIA parameters than the group treated without HSS.

A Two-Year Weight Reduction Program in Obese Sleep Apnea Patients

To evaluate the effects of a 2-year weight reduction program on respiratory disturbances, arousal index, daytime sleepiness, metabolic status, and quality of life in obese patients with obstructive sleep apnea syndrome (OSAS). Prospective intervention study of 33 consecutive obese OSAS patients (24 men, 9 women); 19 subjects used continuous positive airway pressure and 4 used mandibular retaining device, except during nights with sleep recording. The program consisted of 8 weeks of low calorie diet followed by group meetings with behavioral change support. Seventy percent of the patients completed the program; 67% completed the sleep recordings. The success rate for the apnea-hypopnea index (AHI) (< 20 and reduction > or = 50%) was 15% in the intention to treat (ITT) analysis. The AHI showed a nonsignificant decrease in mean values, from 43 to 28. The oxygen desaturation index (ODI) decreased from 42 to 23 (p = 0.010), arousal index from 24 to 11 (p = 0.019), body mass index from 40 to 35 (p = 0.003) and the Epworth Sleepiness Scale (ESS) from 9 to 5 (p = 0.026), all ITT. Metabolic status, physical functioning, and vitality evaluations improved only in the per protocol analysis. Reduction in weight correlated significantly to reductions in ESS (p = 0.038) and insulin levels (p = 0.002), respectively. There were no differences based on gender or use/non-use of OSAS treatment device. Our weight reduction program showed a limited success in reducing AHI. However, there were significant improvements in weight, ODI, arousal index, and subjective symptoms. We recommend the program as an adjunct treatment for well-motivated obese OSAS patients.

Validation of BIA in Obese Children and Adolescents and Re‐evaluation in a Longitudinal Study

Decrease in fat mass (FM) is a one of the aims of pediatric obesity treatment; however, measurement techniques suitable for routine clinical assessment are lacking. The objective of this study was to validate whole-body bioelectrical impedance analysis (BIA; TANITA BC-418MA) against the three-component (3C) model of body composition in obese children and adolescents, and to test the accuracy of our new equations in an independent sample studied longitudinally. A total of 77 white obese subjects (30 males) aged 5-22 years, BMI-standard deviation score (SDS) 1.6-3.9, had measurements of weight, height (HT), body volume, total body water (TBW), and impedance (Z). FM and fat-free mass (FFM) were calculated using the 3C model or predicted from TANITA. FFM was predicted from HT(2)/Z. This equation was then evaluated in 17 other obese children (5 males) aged 9-13 years. Compared to the 3C model, TANITA manufacturer's equations overestimated FFM by 2.7 kg (P < 0.001). We derived a new equation: FFM = -2.211 + 1.115 (HT(2)/Z), with r(2) of 0.96, standard error of the estimate 2.3 kg. Use of this equation in the independent sample showed no significant bias in FM or FFM (mean bias 0.5 +/- 2.4 kg; P = 0.4), and no significant bias in change in FM or FFM (mean bias 0.2 +/- 1.8 kg; P = 0.7), accounting for 58% (P < 0.001) and 55% (P = 0.001) of the change in FM and FFM, respectively. Our derived BIA equation, shown to be reliable for longitudinal assessment in white obese children, will aid routine clinical monitoring of body composition in this population.

The Usefulness of Bioelectrical Impedance Analysis in Differentiating Dyspnea Due to Decompensated Heart Failure

Background Acute dyspnea poses a diagnostic challenge for physicians, and the current methods in differentiating cardiac from non-cardiac causes have been limited to date. Recently, the brain natriuretic peptide (BNP) rapid test has been validated in the emergency room. Nevertheless, the early accumulation of fluid in the interstitial space in the body and in the lungs, which characterizes patients with ADHF, is well estimated by BIA. We investigate whether bioelectrical impedance analysis (BIA) can serve as a noninvasive diagnostic tool in the differential diagnosis of acute decompensated heart failure (ADHF) in the emergency department (ED). Methods and Results A total of 292 patients presenting with acute dyspnea to the ED were evaluated by using a conventional diagnostic strategy and rapid BNP measures. Segmental (Seg) and whole-body (WB) BIA resistance (Rz) and reactance (Xc) on entry were immediately detected. After hospital discharge, an expert team classified enrolled patients into ADHF and non-ADHF. A total of 58.9% of patients had ADHF, whereas 41.1% were non-ADHF. ADHF patients showed significantly ( P < .001) higher BNP values (591.8 ± 501 versus 69.5 ± 42 pg/mL), a significant ( P < .001) reduction of Seg (35.5 + 8.2 versus 66.4 + 10.5) and WB (402.3 + 55.5 versus 513.2 + 41.8) Rz (Ohm), and a significant correlation ( P < .0001) between BNP and Seg ( r = –0,62) and WB ( r = –0.63) bioelectrical Rz was also identified. Multiple regression analysis revealed that whole body and segmental BIA were strong predictors of ADHF alone or in combination with BNP. Conclusions Our data suggest that Seg and WB BIA are a useful, simple, rapid, and noninvasive diagnostic adjunct in the early diagnosis of dyspnea from ADHF.

Prediction from multi-frequency bioelectrical impedance analysis

Bioelectrical impedance analysis (BIA) has been shown to be highly related to skeletal muscle mass and blood volume, both of which are important determinants of maximal oxygen uptake (). The aim of the present study was therefore to investigate the ability of whole-body and segmental multi-frequency BIA to improve current nonexercise prediction models. Data for (mL min−1), anthropometry, self-reported physical activity (PA-R) and BIA were collected in 115 men and women. Multiple linear regression analysis (MLR) was used to develop the most parsimonious prediction model. Segmental BIA was not superior to whole-body measurements. Correlation coefficients between and resistance indices were significantly higher at 500 kHz compared to 50 kHz (p < 0.05). Intracellular resistance index, however, showed the highest correlation with (r = 0.89). After adjusting for age, gender and PA-R, MLR revealed that the inclusion of intracellular resistance index was slightly, but significantly (p < 0.001), superior to models based on anthropometry. Subgroup analyses indicated that the true benefit of BIA might be most prevalent in subjects with particularly low (<2500 mL min−1). In short, whole-body BIA marginally improves the accuracy of nonexercise prediction models and its advantage is most pronounced in individuals with particularly low .