Bioelectrical Impedance Analysis Measurements Research Articles

Comparative Effects of Sleeve Gastrectomy vs. Roux-en-Y Gastric Bypass on Phase Angle and Bioelectrical Impedance Analysis Measures: A Systematic Review and Meta-Analysis

Background/Objectives: The objective of this meta-analysis was to determine the impact of bariatric surgery on phase angle (PhA) and other bioimpedance measures among adults with obesity, comparing the effects of Roux-en-Y gastric bypass (RYGB) and sleeve gastrectomy (SG). Methods: A systematic review and meta-analysis were conducted following PRISMA guidelines, including studies up to May 2024 from MEDLINE, Scopus, Cochrane Library, and Web of Science. Eligible studies assessed PhA changes pre- and post-bariatric surgery in adults with BMI ≥ 30 kg/m2. Data on PhA, fat mass (FM), fat-free mass (FFM), body cell mass (BCM), weight, and BMI were extracted and analyzed. Results: Thirteen studies with a total of 1124 patients were included. Significant PhA reductions were observed at 6 months post-surgery (effect size: −1.00; 95% CI: −1.11 to −0.89; p < 0.001), with a more substantial reduction in RYGB patients compared to SG. FM and FFM decreased significantly at 12 months (FM: −27.58; 95% CI: −32.58 to −22.57; p < 0.001; FFM: −10.51; 95% CI: −12.81 to −8.94; p < 0.001). Weight and BMI showed marked reductions at 6 months (Weight: −31.42 kg; 95% CI: −37.28 to −25.26; p < 0.001; BMI: −11.39; 95% CI: −12.60 to −10.18; p < 0.001), with sustained decreases at 12 and 24 months. Conclusions: Bariatric surgery significantly reduces PhA, FM, FFM, weight, and BMI, with initial greater impacts observed in RYGB compared to SG. PhA shows potential as a marker for monitoring post-surgical recovery and nutritional status. Further long-term studies and standardized measurement protocols are recommended to optimize patient management.

Is body composition important in the context of renal function in pediatric neurogenic bladder?

Neurogenic bladder due to myelomeningocele (MMC) is a significant risk factor for chronic kidney disease in children. Cystatin C (CysC) is a more accurate GFR marker than creatinine as it is unaffected by muscle mass but may be influenced by fat mass and BMI. This study evaluates: (1) GFR measurement accuracy using CysC and creatinine in MMC-related neurogenic bladder, (2) the relationship between body composition via bioelectrical impedance analysis (BIA) and renal parameters, and (3) the use of BIA for non-invasive GFR and body composition assessment. Forty children (median age 9.96years) underwent serum creatinine, CysC testing, and BIA measurements. We assessed age, sex, spinal lesion level, anthropometric measurements, BMI, and activity using Hoffer's scale. GFR was calculated using five creatinine-based formulas, three CysC-based, and three combining CysC and creatinine, including BIA GFR as an alternative approach. Creatinine-based GFR estimates were significantly higher than CysC-based GFR. Although only 30% of MMC patients met the traditional BMI criteria for overweight/obesity, 62.5% were obese based on BIA-measured body fat percentage. Significant differences were found in CysC and CysC-based GFR equations within BMI and fat mass groups. Positive correlations were observed between CysC and body weight, BMI percentiles, body fat mass and fat-to-muscle ratio. Muscle mass positively correlated with creatinine. BIA-determined fat mass percentage is a more sensitive obesity indicator than BMI in MMC patients. CysC levels and CysC-based GFR equations are influenced by body fat mass, requiring consideration of adiposity to avoid misestimating renal impairment.

Bioelectrical Impedance Analysis Demonstrates Reliable Agreement with Dual-Energy X-ray Absorptiometry in Identifying Reduced Skeletal Muscle Mass in Patients with Metabolic Dysfunction-Associated Steatotic Liver Disease and Hypertension.

Background/Objectives: Body composition (BC) affects the risk of developing metabolic dysfunction-associated steatotic liver disease (MASLD) and hypertension (HTN). Currently, dual-energy X-ray absorptiometry (DEXA) is considered the gold standard for assessing BC, even though it has some limitations, including immobility, ionizing radiation, and patient weight restrictions. The aim of the study was to evaluate the correlations of BC parameters measured by bioelectrical impedance analysis (BIA) with those measured by DEXA in patients with MASLD and HTN. Methods: Overall, 78 patients with MASLD and HTN underwent the following study procedures: compilation of an anamnesis, physical examination of a patient, laboratory tests, abdominal ultrasound, BIA, DEXA, and anthropometric measurements. Results: The agreement between BIA and DEXA in diagnosing reduced skeletal muscle mass (SMM) in patients with MASLD and HTN was moderate (kappa values were 0.440 and 0.404 in males and females, respectively). Significant strong direct correlations were found between fat mass (FM) and body fat percentage measured by BIA with corresponding measurements by DEXA (p < 0.001 for both). The area under the receiver operating characteristic curves (AUC) of SMM to body weight ratios calculated using BIA data were 0.834 and 0.929 for reduced appendicular SMM determined by DEXA in males and females with MASLD and HTN, respectively. Conclusions: In conclusion, BIA is an easy-to-use and widely available tool for assessing SMM and FM in patients with MASLD and HTN, demonstrating reliable agreement with DEXA measurement results and completely free of its limitations.

DNA polymorphisms in inflammatory and endocrine signals linked to frailty are also associated with obesity: data from the FRASNET cohort.

Obesity and frailty are prevalent geriatric conditions that share some pathophysiological mechanisms and are associated with adverse clinical outcomes. The relationship between frailty, obesity, and polymorphism remains inadequately explored. Single nucleotide polymorphisms (SNPs) offer insights into genetic predispositions that may influence the development of both frailty and obesity. We aimed at investigating whether SNPs associated with frailty also play a role in obesity. Data were collected from the FRASNET cross-sectional study, which included community-dwelling older individuals residing in Milan and nearby areas. Participants were recruited through random sampling. They underwent multidimensional geriatric assessments, which included the collection of blood samples for SNP analysis. Frailty was assessed using the frailty index, and body composition was evaluated using bioelectrical impedance analysis and anthropometric measures. SNPs related to frailty and linked to the renin-angiotensin system (CYP11B2 rs1799998, AGT rs5051, and AGTR1 rs2131127), apoptosis pathways (CASP8 rs6747918), growth hormone signaling (GHR rs6180), inflammation (TLR4 rs5030717, CD33 rs3865444, and FN1 rs7567647), adducin (ADD3 rs3731566), and the 9p21-23 region (rs518054) were found to be associated with various measures of obesity in community-dwelling older adults. Frailty-related SNPs contribute to obesity in community-dwelling older adults. We identified a novel association between adducin SNPs and visceral fat, which has not been previously reported. Detecting genetic predispositions to obesity and frailty early could aid in identifying individuals at risk, facilitating the adoption of preventive interventions. This represents an initial step toward promoting early intervention strategies.

Correlation Between Intrinsic Capacity and Muscle Strength and Quality in Older Patients with Cardiovascular Disease: A Cross-Sectional Study.

Cardiovascular disease (CVD) has become the leading cause of death worldwide. High muscle mass can reduce the incidence and mortality of CVD. In recent years, increasing attention has been given to the relationship between intrinsic capacity (IC) and CVD. This study aims to explore the relationship between the decline of IC, muscle strength, and muscle quality in older patients with CVD, providing a new method and basis for early recognition of IC decline in the older adults. This cross-sectional study included 475 older individuals from communities in Zhejiang. General data were collected, and a comprehensive geriatric assessment (CGA) was conducted. Participants with CVD were divided into three groups: IC retention, IC impairment, and IC significantly impaired. Bioelectrical impedance analysis (BIA) measurements were completed. Student's t-test or non-parametric tests (Mann-Whitney) were used to analyze the correlation between IC and muscle-related indicators. The best cutoff values were obtained using ROC curve analysis. Compared to non-CVD patients, CVD patients were older, more educated, and had higher rates of polypharmacy and comorbidity. IC decreased more significantly in CVD patients. Age (P=0.001), Fried (P=0.024), and GDS-5 (P=0.002) increased with the severity of IC decline. ADL (P=0.002), MMSE (P=0.000), MNA-SF (P=0.000), SARC-Calf (P=0.026), waist circumference (P=0.037), and muscle quality (P=0.010) decreased with the decline in IC. When IC decreased, the cutoff values for hand grip strength, waist circumference, and muscle quality were 25.45 kg, 72.55 cm, and 3.05, respectively. When IC decreased significantly, the cutoff values were 17.15 kg, 71.55 cm, and 2.28, respectively. The results of this study showed that in patients with CVD, the hand grip strength and muscle quality of patients with IC injury were lower than those of patients with IC retention.

Impact of Elexacaftor–Tezacaftor–Ivacaftor Therapy on Body Composition, Dietary Intake, Biomarkers, and Quality of Life in People with Cystic Fibrosis: A Prospective Observational Study

Background: The combination of elexacaftor–tezacaftor–ivacaftor modulators (ETI) has improved clinical outcomes for people with cystic fibrosis (pwCF). Objectives: This study aimed to evaluate changes in nutritional and morphofunctional assessments, as well as anxiety, depression symptoms, and quality of life, in pwCF after starting ETI therapy. Methods: This was a prospective observational study. We measured body composition (fat mass [FM] and fat-free mass [FFM]) using bioelectrical impedance analysis (BIA) and skinfold thickness measurements (SMs). We also assessed hand grip strength, dietary intake via surveys, blood and stool biomarkers, symptoms of anxiety and depression using the Hospital Anxiety and Depression Scale [HADS], and quality of life through the Cystic Fibrosis Questionnaire—Revised (CFQR). Results: A total of 31 pwCF were evaluated. Significant improvements were observed in respiratory function and quality of life, alongside an average weight increase of approximately 5 kg (60% FM and 40% FFM). The prevalence of malnutrition, based on BMI and the FFM index, decreased significantly, while the rate of overweight/obesity increased. Biomarker analysis indicated better nutrient absorption and reduced intestinal inflammation, as evidenced by significant changes in faecal calprotectin, nitrogen, and fat levels, as well as blood lipid and vitamin profiles. Conclusions: Despite a reduction in caloric intake, an increase in weight was observed one year after initiating ETI. This increase was attributed to gains in both FM and FFM, suggesting improved metabolic efficiency and nutrient absorption. Both SM and BIA were found to be useful assessment tools. These findings indicate the need to modify the nutritional approach, focusing on the quality rather than the quantity of intake, and aiming for an appropriate body composition (FFM) rather than solely focusing on BMI.

Body composition of adults with chronic intestinal failure receiving home parenteral nutrition: A descriptive cohort study.

Chronic intestinal failure (CIF) refers to the long-lasting reduction of gut function below the minimum necessary to absorb macronutrients, water, and/or electrolytes. Patients with CIF likely develop various forms of malnutrition and dehydration, yet studies that focus primarily on body composition are lacking. Therefore, this study aimed to evaluate the body composition of adult patients with CIF. This retrospective descriptive cohort study was performed at the Radboud University Medical Center, a tertiary referral center for CIF treatment in the form of home parenteral nutrition. We collected available bioelectrical impedance analysis (BIA) data from routine care between 2019 and 2023. The primary outcome was body composition, which was evaluated by assessing body mass index (BMI), fat-free mass index (FFMI), and fat percentage (fat%). Overall, 147 adult patients with CIF were included with a median (interquartile range) age of 58 (25-68) years; 69% were female. The mean (SD) BMI was 22.1 (4.3) kg/m2, FFMI was 14.2 (1.9) kg/m2 in females and 17.0 (2.0) kg/m2 in males, and fat% was 33.7% (6.8%) in females and 24.6% (6.4%) in males. 63% had an FFMI below references, and 48% had a high fat%. This study found that most adult patients with CIF have an unfavorable body composition characterized by a high fat% and low FFMI despite having a normal mean BMI. These results highlight the necessity for in-depth nutrition assessment, including BIA measurement. Moreover, future studies should focus on exercise interventions to increase FFMI and improve body composition and function.

Assessing the nutritional status and impact of a series of nutritional interventions on elderly inpatients using bioelectrical impedance analysis: A service evaluation.

The aim of the study was to use bioelectrical impedance analysis (BIA) to assess nutritional status of elderly patients admitted to hospital and quantitatively measure the impact of the Cardiff and Vale University Health Board (CAVUHB) model ward. Secondary objectives were to assess the feasibility of using BIA in this patient population and compare nutrition risk screening tools against fat-free mass index (FFMI). A prospective, comparative, single-centre, service evaluation of a 'model ward for nutrition and hydration' undertaken in medical and rehabilitation beds in a large UK teaching hospital. A total of 450 BIA measurements were taken using a Bodystat Multiscan 5000 on 162 patients; several patients had repeated measurements during their hospital stay. Patients tolerated the procedure well, but lack of accurate weight, implanted medical devices and tissue viability precluded some participants. BIA is quick, non-invasive, simple to complete and can elicit huge data about an individual's body composition. In a larger cohort of medical admissions, BIA could assist in identifying the sensitivity and specificity of the nutrition screening tools. The collective benefit of a series of nutritional interventions preserved nutritional status better in this elderly inpatient population than usual models of care. Although results were not statistically significant, there is an opportunity with the new model of care to better support frail patients and prevent deconditioning.

Ten-electrode bioelectrical impedance analysis (BIA) system: Sensitivity investigation by simulation and phantom experiment

Sensitivity of Bioelectrical Impedance Analysis (BIA) measurement was investigated in this study. Limb segments and the trunk of the body are usually assessed for the whole body impedance in the common-used eight-electrode system. However, even though the trunk is the largest part, the measurement sensitivity of the trunk part is extremely low resulting in low trunk impedance. In this study, a ten-electrode BIA system is proposed to improve the sensitivity of the trunk region by adding two more electrodes at the abdomen and proposing a new measurement scheme. Simulation results showed that the proposed system improved the sensitivity in the trunk region by 3.4–4.2 times. With the eight-electrode system, the content of a body segment could also affect the measured impedance of the other segments, but this effect was substantially reduced in the proposed system. The simulation results were confirmed by a phantom experiment on a piece of pork.

Comparison of two bioelectrical impedance analyzers for estimating body composition in a cohort of pediatric oncology patients

Background and AimsUnfavourable changes in body composition are frequently reported in children with cancer. An easy and affordable method to measure body composition is bioelectrical impedance analysis (BIA). In this study, we compared the Tanita MC780-MA Body Composition Analyzer (Tanita) versus the Bodystat Quadscan 4000 analyzer (Bodystat) to determine whether the Tanita is a suitable analyzer for pediatric oncology patients. MethodsIn this study, 84 childhood cancer patients/survivors were included. Per patient 1, 2 or 3 visits were planned during or after treatment. During each visit, BIA measurements were performed first with the Tanita analyzer followed by the Bodystat analyzer. In total, 131 measurements were included. Spearman correlation and concordance correlation coefficients of Lin (CCC) were calculated for fat percentage (Fat%), fat mass (FM) and fat free mass (FFM). Bland-Altman plots were constructed to assess the agreement between both analyzers. ResultsFat%, FM and FFM values differed statistically significantly when comparing the BIA devices (Wilcoxon signed rank test, p<0.001), but absolute differences between medians were small. Spearman correlations and CCC’s were high for FM (0.94 and 0.92, respectively) and FFM (0.99 and 0.99, respectively), but moderate for Fat% (0.70 and 0.65, respectively). Bland-Altman plots did not show low differences of means (biases; for Fat%, FM and FFM 2,6%, 0,6 kg and -0,6 kg respectively), but relatively large limits of agreement (-9.77% – 15.89% , -5.6 kg – 7.2 kg and -5.9 kg – 4.6 kg respectively). ConclusionsBased on the good agreement between the Tanita and Bodystat on group level, and the fact that the Tanita is a more patient-friendly device, the Tanita can be used to measure body composition instead of the Bodystat in pediatric oncology patients, making it easier and faster to gain information about body composition.

Recent Update on the Prevalence of Sarcopenia in Koreans: Findings from the Korea National Health and Nutrition Examination Survey.

As recognized by the World Health Organization in 2016 with its inclusion in the International Classification of Diseases, Tenth Revision as M62.84, and by South Korea in 2021 as M62.5, the diagnostic guidelines for sarcopenia vary globally. Despite its prevalence in older populations, data on sarcopenia in Koreans aged 60 and above is scarce, highlighting the need for research on its prevalence in this demographic. Utilizing the 2022 Korea National Health and Nutrition Examination Survey dataset, sarcopenia was assessed among 1,946 individuals aged 60 or older according to the Asian Working Group for Sarcopenia 2019 criteria, incorporating grip strength and bioelectrical impedance analysis measurements. Statistical analyses were performed to differentiate categorical and continuous variables using logistic regression and Student's t-tests, respectively. The prevalence of sarcopenia was found to increase with age, with the highest prevalence observed in the oldest age group (80 years and older). The overall prevalence of sarcopenia in our study population was 6.8%. Among men, the prevalence of sarcopenia was 5.5% in the 60 or older age group, 9.6% in the 70 or older age group, and 21.5% in the 80 or older age group. Among women, the prevalence of sarcopenia was 7.9%, 10.5%, and 25.9%, respectively. This study highlights the significant burden of sarcopenia in elderly Koreans, particularly among the oldest individuals. These findings call for targeted interventions to manage and prevent sarcopenia, along with further research on its risk factors, consequences, and effective mitigation strategies.

Nutritional and Body Composition Changes in Paediatric β-Thalassemia Patients Undergoing Hematopoietic Stem Cell Transplantation: A Retrospective Study Using Bioelectrical Impedance Analysis.

This retrospective study evaluated nutritional status and body composition changes in paediatric β-thalassemia (β-TM) patients before and after hematopoietic stem cell transplantation (HSCT), using bioelectrical impedance analysis (BIA), and explored their relationship with HSCT outcomes. A cohort of 40 paediatric β-TM patients undergoing allogeneic HSCT was assessed for their nutritional status, anthropometric parameters, including body mass index (BMI), weight, and height, and body composition parameters pre-and post-HSCT, focusing on BIA measurements, including intracellular water (ICW), extracellular water (ECW), fat mass (FAT), fat-free mass (FFM), Skeletal Muscle Mass (SMM), soft Lean Mass (SLM), percent body fat (PBF), Body Cell Mass (BCM), Phase angle (PA) and muscle balance pre- and post-HSCT. Post-HSCT clinical outcomes, including acute graft-vs-host disease (aGVHD), engraftment time, oral mucositis (OM), sinusoidal obstruction syndrome (SOS), and diarrhoea in relation to nutrition status after HSCT were analysed. After HSCT, 28.21% experienced diminished nutritional status, with 71.43% of those who were wasting before HSCT showing diminished nutritional status, significantly higher than the normal group (18.75%, P = 0.012). Anthropometric changes included significant weight reduction (87.5%, 22.15 ± 7.46 vs 20.74 ± 6.57, P < 0.001) and BMI decrease (90%, 15.19 ± 1.70 vs 14.05 ± 1.48, P < 0.001). Body composition parameters, which are FFM, SMM, SLM, ICW, ECW, BCM, and PA (18.26 ± 5.71 vs 17.27 ± 5.19, 8.68 ± 3.30 vs 7.93 ± 3.02, 17.11 ± 5.28 vs 16.06 ± 4.84, 8.19 ± 2.54 vs 7.62 ± 2.31, 5.15 ± 1.58 vs 4.94 ± 1.47, 11.74 ± 3.63 vs 10.92 ± 3.32, 4.42 ± 0.50 vs 3.90 ± 0.57, respectively, P < 0.001) analysis revealed significant decreases. No significant differences in clinical outcomes were observed based on nutritional status. Paediatric β-TM patients undergoing HSCT exhibit significant changes in nutrition status and body composition, emphasizing the need for focused attention on malnourished children who are more prone to diminished nutritional status. Comprehensive BIA aids in understanding the impact, urging consideration for extended follow-up and larger cohorts in future research.

Reliability and Agreement Assessment of Sarcopenia Diagnosis through Comparison of Bioelectrical Impedance Analysis and Dual-Energy X-ray Absorptiometry.

A unified diagnostic criterion has yet to be established for sarcopenia. Therefore, we analyzed the reliability and validity of sarcopenia diagnosis using bioelectrical impedance analysis (BIA) compared with the gold standard, dual-energy X-ray absorptiometry (DEXA), and evaluated the predictive accuracy of BIA for diagnosis. The clinical trial, involving a total of 239 participants, was conducted between December 2018 and September 2019 on healthy volunteers without significant medical histories. The participants underwent health assessments, followed by sequential DEXA and BIA measurements. In both the low and normal appendicular skeletal muscle (ASM) groups, there were significant differences in the right arm, left arm, right leg, left leg, ASM, and ASM index (ASMI) between DEXA and BIA across all age groups (p < 0.05). BIA tended to overestimate compared to DEXA, but ASMI values for males and females were consistent with the criteria for sarcopenia. Bland-Altman analysis showed that each segment in both the low and normal ASM groups fell within the limits of agreement (LOA). The diagnosis of sarcopenia using BIA was significantly different from that using DEXA. However, it exhibited a significantly high correlation, fell within the LOA, and demonstrated high predictive accuracy. BIA can be considered an effective tool for diagnosing sarcopenia.

Fat and fat-free mass measurement agreement by dual-energy X-ray absorptiometry versus bioelectrical impedance analysis: Effects of posture and waist circumference.

Bioelectrical impedance analysis (BIA) operates under the assumption that the conductor has a uniform cylindrical shape. However, this assumption may be violated if measures are taken in the seated position, especially in people with a high waist circumference (WC). The aims of this research were to determine whether posture (supine, standing, and seated) and WC affect agreement between BIA and dual-energy X-ray absorptiometry (DXA) measures of fat mass (FM) and fat-free mass (FFM). Baseline data were collected from 28 adults (mean=61.4±6.9years, 64.3% female) with obesity (BMI 38.6±5.0kg/m2). Body composition was measured using BIA in the supine, standing, and seated positions and by DXA while supine. Intraclass correlation coefficient (ICC) analyses with two-way mixed effects and absolute agreement were performed to determine agreement. Point estimates were excellent for FM and FFM while supine, excellent for FM and good for FFM while standing, and moderate for FM and good for FFM while seated. BIA measures in the supine position resulted in the narrowest 95% confidence intervals compared with other positions. Better agreement was observed across all positions in participants with a WC below the median (118.3cm). Despite the potential pragmatic value of measuring with BIA in a seated position, the results of this analysis demonstrate the poorest agreement between DXA and BIA methods, especially in individuals with high WC. Findings from this study demonstrate that BIA, particularly when measured in a supine position, can serve as a viable alternative to DXA for measuring body composition in people with obesity.

Bioelectrical Impedance in Premature Newborns and Its Relationship with Diet Therapy in a Neonatal Intensive Care Unit.

(1) Background: To estimate resistance, reactance, and phase angle values among moderate preterm infants and their variation according to neonatal and maternal characteristics and nutritional intake. (2) Methods: This was a cohort that evaluated 43 moderate preterm infants using bioelectrical impedance analysis. The study variables included resistance, reactance, and phase angle measurements, in addition to classification of nutritional intake. (3) Results: Mean resistance was 602.0 ± 118.2 Ω, reactance was 57.2 Ω (IQR = 42.6-65.2), and phase angle was 522° (IQR = 4.1-6.6). Lower resistance values were found in the presence of risky pregnancy (532.2 ± 111.9 Ω vs. 650.9 ± 97.9 Ω, p < 0.001) and lower reactance values, in the presence of harmful maternal lifestyle habits at both the first (p = 0.01) and second assessments (p = 0.01). Eight preterm infants were considered to have insufficient nutritional intake (23.5%); 17, sufficient (50.0%) and 9, partially sufficient (26.5%). There was less reactance among preterm infants with insufficient nutritional intake (p < 0.001). (4) Conclusions: The bioelectrical impedance analysis measurements were within the range of values reported in other studies. There was an association between full diet and adequate nutritional intake with higher resistance values, while a lower reactance value was associated with the presence of risky pregnancy and harmful maternal lifestyle.

The applicability of a commercial 3DO body scanner in measuring body composition in Chinese adults with overweight and obesity: a secondary analysis based on a weight-loss clinical trial.

A commercial three-dimensional optical (3DO) scanning system was reported to be used in body composition assessment. However, the applicability in Chinese adults has yet to be well-studied. This secondary analysis was based on a 16-week weight-loss clinical trial with an optional extension to 24 weeks. Waist and hip circumference and body composition were measured by 3DO scanning at each follow-up visit during the study. Bioelectrical impedance analysis (BIA) was also performed to confirm the reliability of 3DO scanning at each visit. We used Lin's concordance correlation coefficients (CCC) to evaluate the correlation between the two methods above-mentioned. Bland-Altman analysis was also performed to evaluate the agreement and potential bias between different methods. A total number of 70 Chinese adults overweight and obese (23 men and 47 women, aged 31.8 ± 5.8 years) were included in the analysis, which resulted in 350 3DO scans and corresponding 350 BIA measurements. The percent body fat, fat mass, and fat-free mass were 33.9 ± 5.4%, 26.7 ± 4.6 kg, and 50.3 ± 8.7 kg before the trial by 3DO scanning. And they were 30.5 ± 5.8%, 22.5 ± 4.7 kg, and 49.4 ± 8.3 kg after 16 weeks of the trial. Compared with BIA, 3DO scanning performed best in the assessment of fat-free mass (CCC = 0.89, 95%CI: 0.86, 0.90), then followed by fat mass (CCC = 0.76, 95%CI: 0.71, 0.80) and percent body fat (CCC = 0.70, 95%CI: 0.64, 0.75). Subgroup analysis showed that 3DO scanning and BIA correlated better in women than that in men, and correlated better in measuring fat-free mass in participants with larger body weight (BMI ≥28.0 kg/m2) than those with smaller body weight (<28.0 kg/m2). 3DO scanning is an effective technology to monitor changes in body composition in Chinese adults overweight and obese. However its accuracy and reliability in different ethnicities needs further exploration.

Fluid Status Assessment in Critically Ill Patients with COVID-19: A Retrospective Cohort Study.

Fluid status (FS) is a diagnostic challenge in critically ill patients with COVID-19. Here, we compared parameters related to FS derived from cumulative fluid balance (CFB), bioelectrical impedance analysis (BIA) and venous congestion assessed by ultrasound (VExUS) to predict mortality. We retrospectively reviewed the medical records of individuals with severe pneumonia due to COVID-19 between July and November 2021 in a single center. Comorbidities, demographic, clinical and laboratory data as well as results from CFB, BIA and VExUS measurements were collected on admission and weekly afterwards for two consecutive evaluations. Seventy-nine patients were included, of which eighteen (14.2%) died. Abnormalities of FS were only identified by BIA. Extracellular water/total body water ratio (ECW/TBW) > 0.394 (overhydrated) by BIA was a good predictor of mortality (AUC = 0.78, 95% CI: 0.067-0.89). Mortality risk was higher in overhydrated patients (OR: 6.2, 95% CI: 1.2-32.6, p = 0.02) and in persistently overhydrated patients (OR: 9.57, 95% CI: 1.18-77.5, p = 0.03) even after adjustment to age, serum albumin and acute kidney injury (AKI) in stages 2-3. Time to death was shorter in overhydrated patients (HR: 2.82, 95% CI: 1.05-7.5, log-rank test p = 0.03). Abnormalities in FS associated with mortality were only identified by BIA in critically ill patients with COVID-19.

Bioelectrical impedance phase angle and the mortality in critically ill children.

Phase angle (PhA) is a variable obtained from bioelectrical impedance analysis (BIA). It is highly sensitive and specific and is commonly used in clinical nutrition assessment. Recently, PhA has shown promise in predicting clinical outcomes, especially as a new indicator of mortality, but its use in pediatric research is limited. This study aims to investigate the association between PhA measured at admission using BIA and PICU length of stay (LOS) and 60-day mortality in critically ill children and adolescents. A consecutive series of pediatric patients in the PICU underwent BIA measurements within 72 h of admission. All patients met the inclusion and exclusion criteria. Patient demographics, anthropometric measurements, pediatric index of mortality 2 score (PIM-2), and laboratory exams were recorded. Kaplan-Meier (K-M) survival curves were constructed based on the critical PhA value to assess differences in survival status within the 60-day window. Multivariate cox regression model was employed to illustrate the relationship between PhA and 60-day mortality rates. The Youden's index method was used to identify the critical cut-off value for PhA in relation to mortality rates. ROC curves provided the area under the curve (AUC) and a 95% confidence interval (CI). A total of 205 pediatric patients (118 boys) were included, with a mean age of 9.2 years (±6.0). Survival curves indicated a cutoff value of 3.1°, with higher survival in patients with PhA ≥3.1° compared to those with PhA <3.1° (F = 10.51, p < 0.0001). The area under the ROC curve was 0.70, with a sensitivity of 0.65 and specificity of 0.72. Total hospital LOS was longer in the PhA <3.1° group compared to the PhA ≥3.1° group (p = 0.000). The PhA <3.1° group had a longer PICU LOS (adjusted for age and sex, HR 1.871, p = 0.000, log-rank test, p = 0.000). PhA and PIM-2 were two independently significant correlated variables (p < 0.05) for the 60-day mortality rate in this study. Low PhA in patients is associated with longer PICU LOS and an increased risk of PICU patient mortality. PhA not only serves as an indicator for monitoring pediatric nutrition but also as a prognostic indicator for PICU patients.

Body Composition after Endoscopic Lung Volume Reduction with Endobronchial Valves: A Prospective Study.

Patients with chronic obstructive pulmonary disease (COPD) and emphysema experience malnutrition and pulmonary cachexia. Endoscopic lung volume reduction (ELVR) with endobronchial valves has not only improved lung function, exercise capacity, and quality of life but also influenced body weight. Only a few data are available on body composition changes after ELVR. This single-center prospective study of patients with advanced COPD investigates body composition before and after endoscopic valve treatment using multifrequency bioelectrical impedance analysis (BIA). The following parameters were evaluated in addition to clinical data and routine tests: body weight, body mass index (BMI), basal metabolic rate, total body water, body fat, cell percentage, phase angle, intracellular water (ICW), extracellular water (ECW), extracellular mass (ECM), body cell mass (BCM), lean body mass (ECM + BCM), and fat-free mass index. A total of 23 patients (mean emphysema index 37.2 ± 7.5%, BMI 23.4 ± 4.3 kg/m2) experienced improvements in lung function and exercise capacity with ELVR. Complete lobar atelectasis was achieved in 39.1% of participants. A non-statistically significant increase in body weight and BMI was observed after ELVR (p = 0.111 and p = 0.102). BIA measurement revealed a worsening of phase angle, cell percentage and ECM/BCM and thus of body composition, but without statistical significance. This is mainly due to a statistically significant increase in ECM, ECW, and ICW (all p &lt; 0.001). ELVR demonstrated no beneficial changes in body composition, although patients tend to gain weight. A larger cohort is warranted to confirm these findings.

An Investigation of the Role of Phase Angle in Malnutrition Risk Evaluation and Clinical Outcomes in Patients with Head and Neck or Brain Tumors Undergoing Radiotherapy

This cross-sectional study aimed to investigate the role of bioelectrical impedance analysis (BIA) and phase angle measurement in assessing malnutrition in head and neck (n = 37) and brain (n = 63) tumor patients received radiotherapy. Common nutritional screening and assessment tests were used to identify malnutrition in the patients. Each patient underwent these tests once, along with phase angle measurement. Additionally, inflammation parameters, including neutrophil lymphocyte ratio (NLR), platelet lymphocyte ratio (PLR), and systemic inflammatory index (SII), were calculated. All study results were correlated with the phase angle cutoff point of 5.72°. The phase angle demonstrated significant correlations with subjective global assessment (SGA), mini nutritional assessment (MNA) scores, BIA parameters, nutritional index, NLR, and SII (p < 0.05). Moreover, in head and neck tumor patients, those with higher standardized phase angle values exhibited significantly better two-year overall survival (32.1% vs. 87.5%, p = 0.006). The phase angle measurement is a convenient, noninvasive, and reproducible method that can complement existing tools for assessing malnutrition risk in radiotherapy patients. The significant correlations observed between the phase angle and various nutritional, inflammation markers and prognosis highlight its potential utility. Further studies incorporating a larger patient cohort will be beneficial in establishing a standard phase angle reference value for cancer patients.