The validity of bioelectrical impedance phase angle for nutritional assessment in children

Bioelectrical impedance phase angle and the mortality in critically ill children

Background

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.

Methods

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).

Results

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.

Conclusion

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.

Phase angle and anthropometric indicators of cardiometabolic risk in children and adolescents

RATIONALE/OBJECTIVE

The phase angle (PhA) is a measurement obtained from the resistance and reactance found in the bioelectrical impedance examination and is useful in assessing nutritional status and in assessing cardiometabolic diseases. Therefore, the objective was to correlate the phase angle to the anthropometric variables of cardiometabolic risk (CMR) in children and adolescents.

SUBJECTS/METHODS

Weight, height, body mass index (BMI), waist circumference (WC) and neck circumference (NC), waist-to-height ratio (WHtR), and PhA of 1231 children and adolescents aged between 5 and 18 years were assessed. PhA was assessed in tertiles and CMR was identified using the anthropometric variables BMI, WC, NC, and WHtR. Linear regression models were used to verify the association between PhA tertiles and CMR anthropometric variables, stratified by sex.

RESULTS

No relationship was found between PhA and CMR variables in children. In adolescents, lower values of NC (β = -0.019, p = 0.005) and BMI (β = -0.025, p = 0.023) were found in boys, WC (β = -0.017, p = 0.020), WHtR (β = -0.017, p = 0.020), NC (β = -0.011, p = 0.027) and BMI (β = -0.026, p = 0.009) in girls when they were in tertile 1 when compared to tertile 3 of the PhA, even after adjusting for age.

CONCLUSION

The PhA was directly associated with CMR in the assessed adolescents.

Phase angle and its determinants among adolescents: influence of body composition and physical fitness level

To examine the association between levels of physical fitness, parameters of body composition and phase angle (PhA) amongst adolescents. A total of 152 adolescents (84 girls) aged 11-16 years were included in this study. Weight and height were measured and the body mass index (BMI) was calculated. Bioelectrical impedance analysis (BIA) provided resistance and reactance parameters to calculate fat-free mass (FFM), PhA and fat mass (%FM). The following physical fitness variables were analysed: flexibility, abdominal muscular endurance, upper and lower limb explosive strength, agility, speed and cardiorespiratory fitness. Generalized Linear Models were applied to verify differences across sexes. Stepwise linear regression was used to establish an association between the variables studied. The study established an association between PhA and weight, FFM, BMI, FM, %FM and medicine ball throw (MBT) for girls. As for the boys, an association was verified between PhA and weight, FFM, BMI, standing long jump (SLJ), MBT and the three allometric VO2peak variables analyzed. An association was found between PhA and the boys' 4-m shuttle run test (4SRT) and 20-m sprint test (20SRT). Boys showed a greater phase angle than girls; In girls, BMI and %FM, were determinant of 32.4% (r = 0.57). PhA variability which is influenced by physical fitness, body composition and, therefore, the tissues electrical conductivity. Furthermore, boys' height, FFM, upper limb strength, and agility account for 58.4% (r = 0.76) PhA variability. There was a positive correlation between the physical fitness tests and the PhA.

Preoperative Body Composition Correlates with Postoperative Muscle Volume and Degeneration after Total Hip Arthroplasty

Impaired muscle recovery after total hip arthroplasty (THA) may affect gait and activities of daily living. Bioelectrical impedance analysis (BIA) can assess body composition and muscle volume, and computed tomography (CT) can assess muscle volume and the fatty degeneration of muscle. This study aimed to explore the effectiveness of BIA, and the correlation between preoperative body composition and postoperative muscle volume and degeneration after THA using BIA and CT. Thirty-eight patients who underwent THA and had BIA and CT performed pre- and postoperatively were retrospectively assessed. The BIA-derived measurements of preoperative body composition (fat mass index, fat-free mass index, and phase angle) were correlated with the CT-derived measurements (pre- and postoperative muscle volume and gluteus maximus and quadriceps Hounsfield Units of the affected hip). The preoperative fat mass index negatively correlated with the postoperative muscle volume of the gluteus maximus (p = 0.02) and quadriceps (p < 0.001) and the Hounsfield Units of the gluteus maximus (p = 0.03) and quadriceps (p = 0.03). The preoperative fat-free mass index positively correlated with the postoperative muscle volume of the quadriceps (p = 0.02). The preoperative phase angle positively correlated with the postoperative muscle volume of the quadriceps (p = 0.001) and the Hounsfield Units of the gluteus maximus (p = 0.03) and quadriceps (p = 0.001). In patients who underwent THA, preoperative body composition correlated with postoperative muscle volume and the fatty degeneration of the affected lower limb. Preoperative body composition may help predict postoperative muscle volume and fatty degeneration and thus, postoperative recovery.

Phase angle as a marker of outcome in hospitalized pediatric patients. A systematic review of the evidence (GRADE) with meta-analysis

Phase angle (PhA) is a valuable tool for evaluating the nutritional and inflammatory status, which can accompany acute and severe disorders. PhA is a cellular health biomarker, whose value is particularly substantial due to the negative consequences of these situations in the pediatric population. Relevant literature was collected with the aim of comprehensively analysing the evidence on the association between an altered PhA can serve as a predictive-marker for mortality and poor-outcomes in at-risk-pediatric patients. Understanding this relationship could have significant implications for identifying high-risk individuals and implementing timely interventions. A systematic review with meta-analysis was conducted in the primary electronic databases from inception until January 2023. Overall, four studies with a total of 740 patients were eligible for our analysis. Evidence demonstrates that PhA is associated with nutritional status, reflecting undernutrition and changes in body composition related to illness. This review suggests that PhA can indeed be used as an indicator of nutritional status and a tool for predicting prognosis, including mortality and poor-outcomes, in hospitalized pediatric patients. A low PhA was associated with a significant mortality risk [RR:1.51;95%CI (1.22-1.88),p = 0.0002;I2 = 0%,(p = 0.99)] and an increased complications risk [OR:8.17;95%CI (2.44-27.4),p = 0.0007;I2 = 44%,(p = 0.18)]. These findings highlight the importance of taking a comprehensive approach to clinical nutrition, integrating multiple evaluation aspects to establish an accurate diagnosis and personalized therapeutic plans. While PhA emerges as a valuable tool for assessing the risk of malnutrition and as a prognostic-indicator for poor-outcomes in pediatric patients. Further future studies are needed to focus on investigating this relationship in larger and diverse population to strengthen the evidence base.

Association between phase angle and the nutritional status in pediatric populations: a systematic review

Background and aims

Malnutrition is prevalent in pediatric populations with any disease, and it is also related to changes in body composition. In addition, recent studies have documented relationships between these changes and phase angle (PhA), an important parameter of functional nutritional assessment. PhA could be a new marker of nutritional status. Many studies have generated information about the association between PhA and malnutrition in various pathologies, although the vast majority of this information is from adult populations. In this systematic review, we answered the following question: What is the association between PhA and the nutritional status in pediatric populations?

Methods

We performed a systematic search of the Medline/PubMed and Latin American and Caribbean Health Sciences Literature databases (LILACS) databases for studies published up to October 2022. The inclusion criteria were pediatric subjects, which reported the relationship between PhA and the nutritional status with any objective nutritional indicator, and PhA was measured by electric impedance and reported at 50 kHz. We synthesized data from the studies that reported cutoff analysis of PhA with receiver operating characteristic (ROC) curves, mean PhA values presented by nutritional status strata, and correlations between PhA and nutritional status indicators. We assessed the risk of bias by using the Quality Assessment Tool for Observational Cohort and Cross-Sectional Studies and the Quality Assessment for Diagnostic Accuracy Studies.

Results

Of the 126 studies we identified, 15 met the inclusion criteria. The included studies reported the association between PhA and objective indicators of nutritional status, including weight-for-age z-score (WAZ) <-1 standard deviation (SD) for malnutrition, height-for-age z-score (HAZ) for malnutrition-stunting, body mass index (BMI) for the starvation state, body mass index z-score (BMIz) and BMI for malnutrition, mid-upper arm circumference (MUAC) <11 cm for severe acute malnutrition (SAM), and fat-free mass index z-score (FFMIz) <-2 z-score for moderate malnutrition, among others. The report of these associations between PhA and nutritional status was based on cutoff points generated with ROC curve analysis or comparison of mean PhA values, which were reported stratified by the presence or absence of malnutrition, and correlations between PhA and anthropometric indicators for the evaluation of the nutritional status in the pediatric population. It was difficult to compare the studies due to the heterogeneity of the bioelectrical impedance analysis models used, how PhA was reported (standardized, percentiles, or degrees), and the anthropometric indicators used to diagnose malnutrition.

Conclusion

The early identification of malnutrition is relevant to establish the correct nutritional treatment; PhA appears to be a sensitive indicator of nutritional status and is easy to obtain. Although the results of this review are inadequate to establish PhA cutoff points associated with malnutrition in pediatric populations, in most of the studies, there was an association between PhA and objective indicators of nutritional status.

Systematic review registration

https://www.crd.york.ac.uk/prospero/display_record.php?ID=CRD42022362413, identifier: PROSPERO 2022 CRD42022362413.

Can change in phase angle predict the risk of morbidity and mortality during an 18-year follow-up period? A cohort study among adults

Introduction

Phase angle (PhA, degrees), measured via bioimpedance (BIA, 50 kHz), is an index that has been used as an indicator of nutritional status and mortality in several clinical situations. This study aimed to determine the relationship between 6-year changes in PhA and total mortality as well as the risk of incident morbidity and mortality from cardiovascular disease (CVD) and coronary heart disease (CHD) during 18 years of follow-up among otherwise healthy adults.

Methods

A random subset (n = 1,987) of 35-65 years old men and women was examined at the baseline in 1987/1988 and 6 years later in 1993/1994. Measures included weight, height, and whole-body BIA, from which PhA was calculated. Information on lifestyle was obtained through a questionnaire. The associations between 6-year PhA changes (ΔPhA) and incident CVD and CHD were assessed by Cox proportional hazard models. The median value of ΔPhA was used as the reference value. The hazard ratio (HR) model and confidence intervals (CIs) of incident CVD and CHD were used according to the 5th, 10th, 25th, 50th, 75th, 90th, and 95th percentiles of ΔPhA.

Results

During 18 years of follow-up, 205 women and 289 men died. A higher risk of both total mortality and incident CVD was present below the 50th percentile (Δ = -0.85°). The highest risk was observed below the 5th percentile (ΔPhA = -2.60°) in relation to total mortality (HR: 1.55; 95% CI: 1.10-2.19) and incident CVD (HR: 1.52; 95% CI: 1.16-2.00).

Discussion

The larger the decrease in PhA, the higher the risk of early mortality and incident CVD over the subsequent 18 years. PhA is a reliable and easy measure that may help identify those apparently healthy individuals who may be at increased risk of future CVD or dying prematurely. More studies are needed to confirm our results before it can be definitively concluded that PhA changes can improve clinical risk prediction.

Correlation of Body Composition via Bioelectrical Impedance Analysis and Motor Function and Recovery of Upper Extremity in Patients Undergoing Stroke Rehabilitation

Bioelectrical impedance analysis (BIA) has been used to investigate the body compositions and predict functional outcomes in patients with stroke, while the role of BIA to predict motor function or recovery in stroke has not been clarified. This study aimed to investigate relationship between body composition measured by BIA and upper limb motor function and recovery. Body compositions (soft tissue lean mass, phase angle, body fat mass and body water) of fifty patients who are admitted to the stroke rehabilitation unit were segmentally analyzed via BIA. The motor recovery of upper extremity (UE) was evaluated via Fugl-Meyer Assessment (UE-FMA) at the time of transfer and discharge. Correlations between body composition and UE-FMA at discharge were analyzed using Spearman correlation coefficient. Multiple regression analysis was used to determine the regression between body composition and motor function and recovery. The Δ Phase angle, the difference of both sides was significantly linearly inversely correlated with UE-FMA at discharge. However, in multiple regression analysis, body compositions including phase angle did not significantly predict motor function at discharge or motor recovery. The Δ Phase angle is related to the severity of upper limb motor function at discharge in subacute stroke patients, and further studies are needed to determine its value as a predictor for motor recovery.

Phase Angle and Handgrip Strength as a Predictor of Disease-Related Malnutrition in Admitted Patients: 12-Month Mortality

Background: Phase Angle (PhA) value measured by bioelectrical impedance analysis (BIA) could be considered a good marker of the patient’s cell mass and cellular damage. Various studies have shown that the value of PhA is associated with an increased nutritional risk in several pathologies. However, not many studies have focused on the use of PhA as a screening tool in admitted patients. The aim of this study is to evaluate the prognostic value of PhA to determine disease-related malnutrition (DRM) and the risk that this entails for mortality and length of stay (LOS). Methods: 570 patients admitted to the hospital for different causes were included in this retrospective observational study. Patients’ nutritional risk was assessed by screening tests such as the Malnutrition Universal Screening tool (MUST) and Subjective Global Assessment (SGA), in addition to non-invasive functional techniques, such as BIA and handgrip strength (HGS), 24−48 h after admission. After performing an SGA as the gold standard to assess malnutrition, PhA and SPhA values were used to determine DRM. Furthermore, both samples: malnutrition status (MS) and non-malnutrition status (NMS) were compared, with SphA-Malnutrition corresponding to a diagnosis of malnutrition. Statistical analysis of the sample was conducted with JAMOVI version 2.2.2. Results: Patients with MS had lower PhA and SPhA than patients with NMS (p < 0.001). The ROC curve analysis (AUC = 0.81) showed a cut-off point for MS for PhA = 5.4° (sensitivity 77.51% and specificity 74.07%) and AUC = 0.776 with a cut-off point for SPhA = −0.3 (sensitivity 81.74% and specificity 63.53%). Handgrip strength (HGS) was also observed to be a good predictor in hospitalized patients. Carrying out a comparative analysis between MS and NMS, length of stay (LOS) was 9.0 days in MS vs. 5.0 days in NMS patients (OR 1.07 (1.04−1.09, p < 0.001)). A low SPhA-malnutrition value (SPhA < −0.3) was significantly associated with a higher mortality hazards ratio (HR 7.87, 95% CI 2.56−24.24, p < 0.001). Conclusion: PhA, SPhA and HGS are shown to be good prognostic markers of DRM, LOS and mortality and could therefore be useful screening tools to complement the nutritional assessment of admitted patients.

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

INTRODUCTION

Phase 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.

METHODS

A 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.

RESULTS

Multiple 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).

CONCLUSION

PhA 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.

Nonthyroidal illness syndrome (NTIS) in severe COVID-19 patients: role of T3 on the Na/K pump gene expression and on hydroelectrolytic equilibrium

Background

Nonthyroidal Illness Syndrome (NTIS) can be detected in many critical illnesses. Recently, we demonstrated that this condition is frequently observed in COVID-19 patients too and it is correlated with the severity the disease. However, the exact mechanism through which thyroid hormones influence the course of COVID-19, as well as that of many other critical illnesses, is not clear yet and treatment with T4, T3 or a combination of both is still controversial. Aim of this study was to analyze body composition in COVID-19 patients in search of possible correlation with the thyroid function.

Methods and findings

We report here our experience performed in 74 critically ill COVID-19 patients hospitalized in the intensive care unit (ICU) of our University Hospital in Rome. In these patients, we evaluated the thyroid hormone function and body composition by Bioelectrical Impedance Analysis (BIA) during the acute phase of the disease at admission in the ICU. To examine the effects of thyroid function on BIA parameters we analyzed also 96 outpatients, affected by thyroid diseases in different functional conditions. We demonstrated that COVID-19 patients with low FT3 serum values exhibited increased values of the Total Body Water/Free Fat Mass (TBW/FFM) ratio. Patients with the lowest FT3 serum values had also the highest level of TBW/FFM ratio. This ratio is an indicator of the fraction of FFM as water and represents one of the best-known body-composition constants in mammals. We found an inverse correlation between FT3 serum values and this constant. Reduced FT3 serum values in COVID-19 patients were correlated with the increase in the total body water (TBW), the extracellular water (ECW) and the sodium/potassium exchangeable ratio (Na_e:K_e), and with the reduction of the intracellular water (ICW). No specific correlation was observed in thyroid patients at different functional conditions between any BIA parameters and FT3 serum values, except for the patient with myxedema, that showed a picture similar to that seen in COVID-19 patients with NTIS. Since the Na⁺/K⁺ pump is a well-known T3 target, we measured the mRNA expression levels of the two genes coding for the two major isoforms of this pump. We demonstrated that COVID-19 patients with NTIS had lower levels of mRNA of both genes in the peripheral blood mononuclear cells (PBMC)s obtained from our patients during the acute phase of the disease. In addition, we retrieved data from transcriptome analysis, performed on human-induced pluripotent stem cell-derived cardiomyocytes (hiPSC-CM)s treated with T3 and we demonstrated that in these cells T3 is able to stimulate the expression of these two genes in a dose-dependent manner.

Conclusions

In conclusion, we demonstrated that measurement of BIA parameters is a useful method to analyze water and salt retention in COVID-19 patients hospitalized in ICU and, in particular, in those that develop NTIS. Our results indicate that NTIS has peculiar similarities with myxedema seen in severe hypothyroid patients, albeit it occurs more rapidly. The Na⁺/K⁺ pump is a possible target of T3 action, involved in the pathogenesis of the anasarcatic condition observed in our COVID-19 patients with NTIS. Finally, measurement of BIA parameters may represent good endpoints to evaluate the benefit of future clinical interventional trials, based on the administration of T3 in patients with NTIS.

Body Composition and Selected Nutritional Indicators in Healthy Adults-A Cross-Sectional Study

Background

Body mass composition is subject to constant change and is multifactorially determined. Its analysis in different age groups allows a better understanding of the determinants of the human organism in health and disease.

Aim

The study was aimed to conduct cross-sectional assessment of body composition and selected nutritional indicators in healthy adults.

Methods

The cross-sectional study carried out from March 2016 to April 2018 was preceded by a monthly pilot study. All 1333 adults (women 795, 59.6%) aged 20–59 included in the study were from the urban and rural area of the Podkarpackie Province (Poland). These adults were classified into four 10-year age bands. To obtain reliable assessment, selected screening (anthropometry) and in-depth (bioelectrical impedance including phase angle and bioelectrical impedance vector analysis) methods were used.

Results

In women, the proportion of individuals affected by overweight and obesity increases significantly with age, with a less pronounced trend in men, as reflected in the observed differences in individual body composition components. A slight (0.45–0.60) correlation was also observed between body mass index (BMI) and percentage of fat mass (FM %) among men with an increasing strength of the association with age, decreasing in the 50–59 years group. In the female group, the correlations described are at a much higher level (0.80 or higher). The described changes in body composition were reflected in body type from athletic to obese, measured by means of the bioelectrical impedance vector analysis (BIVA) method.

Conclusions

Age and gender significantly differentiate body composition of the adult human body. The body composition analysis should be considered as complement screening assessment method, especially as a support for the assessment of nutritional status expressed by BMI.

Association between phase angle and height-to-age index classifications of children under five years of age

BACKGROUND & AIMS

The phase angle (PA) has been used as an indicator of prognosis and nutritional status because it reflects the integrity of the individuals' cellular function. In contrast to the investigations that assessed acute malnutrition (weight deficit) and PA in children, studies that evaluated the relationship of this indicator with stunting (height deficit) are still scarce and inconclusive. Thus, we aim to investigate whether there are differences in PA according to the classifications of the height-for-age (H/A) index of children under five years of age.

METHODS

This is a cross-sectional study carried out in a nutritional recovery center, in households, and in a daycare center in Maceió-Alagoas, Brazil. Anthropometric data were collected, and resistance and reactance were obtained through the use of tetrapolar electrical bioimpedance, from children aged 2-5 years. The PA and the percentage of body fat were calculated. Children were divided into 3 groups: adequate H/A, at-risk of stunting and stunted. Analysis of covariance for the main outcome was performed using age, sex, and the body mass index-to-age as covariates, and the H/A classification as the exposure.

RESULTS

The mean children's PA in the adequate H/A group was 3.9° [95% CI 3.6-4.2], while in the group at-risk of stunting and stunted it was 4.5° [95% CI 4.3-4.7] and 4.6° [95% CI 4.4-4.8], respectively, showing statistical difference (p < 0.01).

CONCLUSION

In the present sample, stunted children have higher PA values than children with adequate H/A.

Body composition assessment using bioelectrical impedance analysis (BIA) in a wide cohort of patients affected with mild to severe obesity

BACKGROUND & AIMS

Obesity is characterized by fat mass excess (FM), extra cellular water increase (ECW) and, with ageing, decrease in fat free mass (FFM). The validity of body impedance analysis (BIA) in patients with mild to severe obesity is still debated. The purpose of this study is to describe the Resistance (Rz) and Reactance (Xc) values obtained by Body Impedance Analysis (BIA) in a wide cohort of Italian patients with mild to severe obesity. The secondary endpoint is to describe the resulting body composition values (as percentage and indexes) in this population.

METHODS

The study enrolled adult in-patients with mild to severe obesity (classified with class I, II and III obesity) undergoing clinical care rehabilitation program for obesity complications and weight loss. BIA values were grouped by sex, BMI and age classes.

RESULTS

A total of 8303 patients with obesity, aged 18 to 90 y, were studied. The Resistance (Rz) and Reactance (Xc) were reported by sex, age and BMI classes. In women and men both, the phase angle (PhA) decreases with increasing BMI (kg/m²) and the resulting BIA vector was significantly shifted. The FM index (FMI) was higher (p < 0.0001) in women while FFM index (FFMI) was higher in men (p < 0.0001) and significantly associated with BMI. FFMI decreased with age in both sex (p < 0.0001). Skeletal mass (SM) presents a progressive reduction in relation to age and gender both.

CONCLUSIONS

The present BIA-based body composition analysis in a wide cohort of mild to severe obese patients revealed a significantly decreased Rz and Xc values with a consequent significant decrease of PhA in a BMI-dependent manner. The body compartments estimation with available equations was BMI, sex and age dependent. These observational results could be the basis for the development of new equations adapted for patients suffering from obesity.

Changes in Anthropometric Parameters After Anti-TNFα Therapy in Inflammatory Bowel Disease: A Systematic Review and Meta-analysis

Background

Tumour necrosis factor (TNF)-α inhibitors have been widely used for the treatment of moderate-to-severe inflammatory bowel disease (IBD). TNFα also plays an important role in the regulation of weight homeostasis and metabolism and has been linked to variations in anthropometric responses. This relationship in patients with IBD has yet to be determined.

Objectives

Our objective was to evaluate the effects of TNFα inhibitors on changes in anthropometric measures in both adults and children with IBD through a systematic review and meta-analysis.

Methods

Multiple database searches identified studies involving children and adults with IBD and treated with TNFα inhibitors and reporting at least one primary outcome measure. Where possible, data were combined for meta-analysis. The primary outcomes included weight, body mass index (BMI), waist circumference, height, height/velocity, and fat and lean mass. Secondary outcomes included surrogate markers of disease activity. A random-effects model was used to estimate the standardised mean difference (SMD).

Results

In total, 23 cohort studies (total 1167 participants) met the inclusion criteria. Meta-analysis was performed on 13 of these studies. In children, 6–29.3 months of anti-TNFα therapy had a small but statistically significant effect on weight (SMD 0.31; 95% confidence interval [CI] 0.12–0.49; P = 0.001) with a mean gain in z score of 0.30 (standard error [SE] 0.12). In adults, 2–22.4 months of treatment had a moderate effect on BMI (SMD 0.72; 95% CI 0.17–1.26; P = 0.010; mean gain 1.23 kg/m²; SE 0.21). A small but statistically significant increase in BMI z score was found in children (SMD 0.28; 95% CI 0.03–0.53; P = 0.026; mean change 0.31 ± standard deviation [SD] 0.14) after 12–29.3 months of therapy. A meta-analysis of four studies found a negligible but statistically significant increase in height (SMD 0.16; 95% CI 0.06–0.26; P = 0.002; mean change 0.17 z score [SE 0.05]). A negligible effect on fat mass (SMD 0.24; 95% CI −0.19–0.66; P = 0.272) was found in a meta-analysis of five studies. Of note, despite the high heterogeneity among the studies that addressed the issue, these results were also consistently supported by findings from studies not included in the meta-analysis and reviewed in the systematic review. Unfortunately, a lack of data meant we were unable to perform moderator analysis on observed heterogeneity.

Conclusion

Anti-TNFα treatment appears to be associated with an increase in body weight, BMI, and other anthropometric parameters. Given the differing courses of IBD between children and adults, this association should be considered before initiating biologics for undernourished, overweight, and obese patients.

Registration: PROSPERO registration number CRD42020163079.

Electronic supplementary material

The online version of this article (10.1007/s40259-020-00444-9) contains supplementary material, which is available to authorized users.

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

PURPOSE

This study aimed to examine the association between whole-body or segmental phase angle (PhA) based on bioelectrical impedance analysis (BIA) and aerobic capacity (endurance), complex gait ability, and total fitness age score (FAS).

METHODS

A total of 426 community-dwelling older adults (332 women and 94 men) aged 60 to 93 years participated in this study. PhA and appendicular skeletal mass index (ASMI) were obtained by an eight-electrode standing BIA. Aerobic capacity was assessed using the shuttle stamina walk test (SSTw); complex gait ability, using the timed-up-and-go test (TUG). FAS was obtained using the previously validated multi-dimensional equations based on 7-year longitudinal data. SSTw, TUG, and FAS were compared between the low PhA (<4.4° for women and <5.2° for men) and normal PhA groups. Pearson's correlation between PhA and SSTw, TUG, and FAS was determined. Multiple linear regression analysis was conducted using SSTw, TUG, and FAS as dependent variables. Age, sex, height, body mass index (BMI), ASMI, and PhA were entered into the linear model.

RESULTS

SSTw and TUG results and FAS were significantly lower in the low PhA group (P < 0.05). PhA was significantly correlated with SSTw, TUG, and FAS (P < 0.001), and leg PhA showed a stronger correlation than whole-body or arm PhA. PhA at 50 kHz had higher correlation coefficients with SSTw, TUG, or FAS compared with PhA at 5 or 250 kHz. Multiple regression analyses indicated that leg PhA at 50 kHz was a significant predictor of SSTw, TUG, and FAS, independent of age, sex, height, BMI, and ASMI.

CONCLUSION

Our results indicate that leg PhA is associated with multi-dimensional physical fitness in community-dwelling older adults. PhA is a highly informative biomarker of skeletal muscle and exercise physiology in clinical settings.

The Predictive Role of Raw Bioelectrical Impedance Variables in Disordered Eating Attitudes in Female Ballet Dance Students

The present study used receiver operating characteristic (ROC) curve analysis to investigate the accuracy of body composition and raw bioelectrical impedance analysis (BIA) in correctly classifying disordered eating attitudes (DEA) in dance students. Participants were 81 female dancers assigned in two groups: beginner training (BT; age (mean ± SD) = 10.09 ± 1.2 years, n = 32) and advanced training (AT; age = 15.37 ± 2.1 years, n = 49). Fat mass (FM) was estimated by Slaughter's equation and skeletal muscle with Poortman's equation. Impedance (Z), resistance (R), reactance (Xc) and phase angle (PhA) were obtained through multifrequency BIA at a frequency of 50 kHz. Fat-free mass (FFM) was assessed using Sun's equation. For evaluation of DEA, the Eating Attitudes Test-26 (EAT-26) questionnaire was performed. We defined an EAT-26 score ≥ 20 as positive for DEA. Comparisons between groups were performed by a one-way ANOVA test or Kruskall-Wallis test. Spearman's rank correlation coefficients were performed to assess associations between variables. ROC curve analysis was utilized to test the accuracy of body composition and BIA variables in predicting DEA. In the BT group, Xc and PhA demonstrated high accuracy in predicting DEA with an area under the curve (AUC) of 0.976 (95% confidence interval (CI): 0.85-1.00) and 0.957 (95% CI: 0.82-0.99), respectively, (both p < 0.0001). FFM Sun had an AUC of 0.836 (95% CI: 0.66-0.94) (p < 0.0001) in the BT group and FFM Slaughter was 0.797 (95% CI: 0.66-0.90) (p < 0.001) in the AT group. Reactance and Phase angle were excellent and useful predictors of DEA in the BT group.

Evaluating of altered hydration status on effectiveness of body composition analysis using bioelectric impedance analysis

Body composition analysis may provide valuable information about the assessment of balance between fluid, fat, and fat-free mass. The present study assessed whether the regular increase in water consumption has any significant effects on measurements of body composition using BIA. A total of 140 subjects participated in this study. Body composition analyses of the subjects were performed for five times using foot to foot BIA; first at baseline and four times, after 15 minutes of each 500 mL water intakes. There was overestimation in body fat mass compared to the baseline and increased significantly after water intakes in males (2.08% in 500 mL, 3.80% in 1000 mL, 5.88% in 1500 mL, and 7.92% in 2000 mL, p < 0.05) and in females (3.4% in 500 mL, 5.7% in 1000 mL, 7.8% in 1500 mL, and 9.4% in 2000 mL, p < 0.05). In contrast, there was markedly underestimation of total body water and fat-free mass in males (35% and 50%) and females (17% and 22%), respectively, at the end of the study. Thus, overestimation of body fat mass and lower estimation of total body water and fat-free mass with closely to the amount of water retention using BIA application should be considered in health-related clinical practice.

Effects of High-Dose Vitamin D Supplementation on Phase Angle and Physical Function in Patients with Prostate Cancer on ADT

PURPOSE

Androgen deprivation therapy (ADT) is commonly used to treat patients with advanced prostate cancer but is associated with functional decline. Bioelectrical impedance analysis (BIA)-derived phase angle may reflect frailty and functional decline in cancer patients. High-dose vitamin D supplementation may improve phase angle values and physical function.

METHODS

We conducted an exploratory analysis from a phase II randomized controlled trial investigating the efficacy of high-dose vitamin D supplementation in prostate cancer patients (age ≥ 60 yrs). Fifty-nine patients were randomized to high-dose vitamin D (600 IU/day plus 50,000 IU/week) or low-dose: RDA for vitamin D (600 IU/day plus placebo weekly) for 24 weeks. Phase angle was measured by BIA. Physical function measures included handgrip strength, 6-minute walk test, Short Performance Physical Battery and leg extension. All testing was completed at baseline, week 12 and week 24.

RESULTS

Phase angle values were wider over the entire study in the high-dose vitamin D arm indicating healthier muscle cells. The low-dose vitamin D arm had phase angle values consistent with frailty cutoffs in older men (<5.7°).

CONCLUSION

Patients in the high-dose vitamin D arm experienced wider phase angle values over the course of the study which may indicate less frailty. ClinicalTrials.gov ID: NCT02064946.

Can Phase Angle in Newborns at Neonatal Intensive Care Units Be an Indicator of Mortality and Prognosis?

BACKGROUND

The bioelectrical impedance (BI) phase angle (PA), analyzed directly through BI analysis (BIA), is determined by tissue cellularity, representing a direct measure of cellular stability and, for this reason, has been studied and considered as an indicator of prognosis and nutrition status in adults and children.

OBJECTIVE

We aimed to determine if PA can be an indicator of mortality and prognosis in newborns admitted to the neonatal intensive care unit (NICU).

METHODS

Transversal study conducted at a public NICU in Curitiba, Paraná, Brazil. All newborns, preterm and term, were considered eligible for the study if admission to the NICU occurred by the first hour of life. The Score for Neonatal Acute Physiology II, as well as the Perinatal Extension version, were developed to assess the risk of mortality for all newborns, measured within 12 hours of admission. BIA measurements were conducted using the tetrapolar BioScan Maltron 916, with single-frequency (50 kHz) tetrapolar BI. PA was calculated as the arc tangent: (Xc/R) x 180°/π.

RESULTS

BIA was measured during the first 24 hours of admission for all newborns (n = 93), repeated between 24 and 48 hours (n = 79) and again after 7 days (n = 55), always when possible. PA measurements decreased in the first 48 hours in premature newborns, particularly among those who died. The premature newborns also showed a significant decrease from the first to the last PA measurement (P = .001). In addition, whereas full-term newborns showed an increase of PA at 1 week of life, preterm infants continued to have a decrease in values. For preterm newborns, PA measurements decreased and more sharply so for those who died. This result should be viewed with caution given the small number of deaths, but it should be investigated to understand the role of PA in the prognosis of NICU newborns.

CONCLUSIONS

The absolute value of PA during the first 24 hours of life was not a good marker for severity or mortality. However, the decrease of PA between different moments of evaluation was a good marker of severity. The decrease of PA in the first 48 hours in premature newborns, and that when the decrease is more pronounced, may be indicative of mortality. The difference in PA values between these newborns is probably a significant variable for mortality and prognosis and not a cutoff value.

Benefits of Exercise Training for Children and Adolescents Undergoing Cancer Treatment: Results From the Randomized Controlled MUCKI Trial

Objective: In cancer patients, the impairment in muscle function is a frequently observed phenomenon. However, comprehensive evaluation of the effect of exercise training on muscle function in childhood cancer patients (CCPs) is sparse and therefore investigated in the MUCKI trial. Study Design: In the randomized controlled MUCKI trial, CCPs during intensive cancer treatment and aged 4-18 years were recruited. Eligible patients were enrolled soon after diagnosis as long as they were physically and mentally able to participate in exercise testing and training. Patients of the exercise group (n = 16) participated in average 2.7 ± 1.2 times per week in a combined resistance and endurance training with moderate exercise intensity, for a time period of 8.0 ± 2.1 weeks, while patients of the control group (n = 17) received usual care. Leg strength was evaluated as the primary endpoint. Secondary endpoints were 6-min walk performance, arm strength, body composition, fatigue, and health-related quality of life. Results: Comparisons of pre- and post-intervention results were evaluated by baseline and stratification criteria adjusted analysis and showed positive effects for the exercise group regarding leg strength [F _{(1, 20)} = 5.733; p = 0.027^*; η p 2 = 0.223], walking performance [F _{(1, 25)} = 4.270; p = 0.049^*; η p 2 = 0.146], fatigue [F _{(1, 13)} = 8.353; p = 0.013^*; η p 2 = 0.391], self-esteem [F _{(1, 6)} = 6.823; p = 0.040^*; η p 2 = 0.532], and self-reported strength and endurance capacity [F _{(1, 6)} = 6.273; p = 0.046^*; η p 2 = 0.511]. No significant differences were found for the other parameters. Conclusion: Within one of the first randomized controlled trials, the present study provides evidence for a positive effect of combined training in CCPs during intensive cancer treatment. Further research is needed to confirm these results and to evaluate their clinical impact. Clinical Trial Registration Number: NCT02612025.

Anthropometrical and Bioelectrical Impedance Analysis Parameters in Anorexia Nervosa Patients' Nutritional Status Assessment

Background and Objectives: Body mass index (BMI) is still the only recommended measurable nutritional status assessment parameter in anorexia nervosa (AN). The aim of this study was to measure other anthropometrical and bioelectrical impedance analysis (BIA) parameters in AN patients and to evaluate their nutritional status assessment value. Materials and Methods: The 46 AN female patients were examined at the beginning of hospitalization and followed-up in three measurements (in 6 ± 2 weeks’ intervals). Anthropometrical assessment was based on BMI, circumferences of arm, calf, thigh, hips, waist, their ratio (waist-to-hip ratio (WHR)), and a skinfold test over biceps and triceps muscle, under the scapula, over the hip, and 2 cm from the umbilicus. The BIA parameters included phase angle (PA), membrane capacitance (Cm), and impedance at 200 kHz, and a 5 kHz ratio (Z_200/5). Results: In the 1st measurement, BMI correlated with all anthropometric and BIA parameters (p < 0.05). For BIA parameters, the correlation included arm circumference and WHR (p < 0.05). In the follow-up, significant changes were observed in BMI and all BIA parameters. The correlation between BMI and all BIA parameters was present in the 2nd and 3rd measurements (p < 0.05). In the 4th measurement, BMI correlated only with Cm (p = 0.0114). Comparison of BIA parameters according to the state of starvation (BMI < 16.0 kg/m²) revealed that all studied BIA parameters were characterized by statistically significant sensitivity and specificity in the detection of this condition (p < 0.05), except PA in the 4th measurement (p = 0.2099). Conclusions: Selected BIA and anthropometrical parameters could be used for AN patients’ assessment. The study confirmed dynamic changes of BIA parameters during the follow-up. They could be useful in the detection of the state of starvation.

An evaluation of phase angle, bioelectrical impedance vector analysis and impedance ratio for the assessment of disease status in children with nephrotic syndrome

Background

Oedema, characterized by accumulation of extracellular water (ECW), is one of the major clinical manifestations in children suffering from nephrotic syndrome (NS).

The lack of a simple, inexpensive and harmless method for assessing ECW may be solved by the use of the bioelectrical impedance analysis (BIA) technique.

The aims of this study were to examine whether phase angle (PA), bioelectrical impedance vector analysis (BIVA) and the impedance ratio (IR) reflect change in disease status in children with NS.

Methods

Eight children (age range: 2–10 years) with active NS (ANS group) were enrolled. In five of these (ANS* subgroup), impedance was also measured at remission (NSR group). Thirty-eight healthy children (age range: 2–10 years) were included as healthy controls (HC group). Whole-body impedance was measured with a bioimpedance spectroscopy device (Xitron 4200) with surface electrodes placed on the wrist and ankle.

Results

Values of PA, BIVA and IR were found to be significantly lower (p-value range < 0.001 to < 0.01) in the ANS patients compared to the HC and NSR groups. No significant differences were observed between the NSR and HC groups.

Conclusion

The studied parameters can be used to assess change in disease status in NS patients. Data were consistent with NS being associated with expansion of ECW.

Electronic supplementary material

The online version of this article (10.1186/s12882-019-1511-y) contains supplementary material, which is available to authorized users.

Bioelectrical Impedance Analysis for Prediction of Early Complications after Gastrectomy in Elderly Patients with Gastric Cancer: the Phase Angle Measured Using Bioelectrical Impedance Analysis

Purpose

Phase angle obtained using bioelectrical impedance analysis (BIA) provides a relatively precise assessment of the nutritional status of elderly patients. This study aimed to evaluate the significance of phase angle as a risk factor for complications after gastrectomy in elderly patients.

Materials and Methods

We evaluated 210 elderly patients (aged ≥65 years) who had undergone gastrectomy for gastric cancer between August 2016 and August 2017. The phase angle cutoff value was calculated using receiver operating characteristic curve analysis according to sex. A retrospective analysis regarding the correlation between early postoperative complications and well-known risk factors, including the phase angle, was performed.

Results

Multivariate analysis revealed that the presence of two or more comorbidities (odds ratio [OR], 3.675) and hypoalbuminemia (OR, 4.059) were independent risk factors for overall complications, and female sex (OR, 2.993) was independent risk factor for severe complications. A low phase angle (OR, 2.901 and 4.348, respectively) and total gastrectomy (OR, 4.718 and 3.473, respectively) were independent risk factors for both overall and severe complications.

Conclusions

Our findings show that preoperative low phase angle predicts the risk of overall and severe complications. Our findings suggest that BIA should be performed to assess the risk of postoperative complications in elderly patients with gastric cancer.

Phase angle is associated with the physical fitness of HIV-infected children and adolescents

The objective of this study was to identify the association of phase angle with physical fitness in children and adolescents infected with HIV. Sixty-four children and adolescents infected with HIV (8-15 years old) were tested for vertical transmission. The electrical bioimpedance was used to obtain the phase angle. Body fat (BF) and lean soft tissue mass (LSTM) were measured by x-ray absorptiometry, and the manual grip strength was evaluated by dynamometry. The peak oxygen consumption (VO₂ peak) was measured by respiratory change in a submaximal incremental test. Moderate-vigorous physical activity (MVP) and sedentary behavior were measured using accelerometers and were used as covariates. Multiple linear regression was used. The linear correlation analyses demonstrated that the phase angle was inversely proportional to relative BF (r = -0.26), but was not associated with absolute body fat (r = -0.02). The phase angle was directly associated with LSTM (r = 0.57), handgrip strength, and (r = 0.43) peak VO₂ (r = 0.55). The phase angle was not associated with absolute BF (β = -0.017, P = 0.413) and relative (β = -0.014, P = 0.175). The phase angle presented a direct association with LSTM (β = 0.041, P = 0.019) and peak VO₂ (β = 0.005; P = 0.019), regardless of age, sex, sexual maturation, MVPA, sedentary behavior, antiretroviral drugs, and viral load. No association was found between phase angle and handgrip strength (β = 0.153; P = 0.199). It was concluded that phase angle was associated with LSTM and the aerobic fitness in HIV-infected children and adolescents.

Malnutrition and medical nutrition therapy in hospitalized children: a case study of using national malnutrition screening tools in northeastern Iran

Background

Nationwide studies have focused only on prevalence of malnutrition in hospitalized children, while medical nutrition therapies and assessing nutritional interventions is neglected.

Methods

This research was conducted in tertiary level children hospitals in the NorthEastern region of Iran for 1 year from 2016 to 2017. Five questions were included in the initial assessment form and, if there was even one positive response, nutritional interventions were prescribed for the patients.

Results

A total of 65 children aged ≥ 5 years and hospitalized for ≥ two days were included. 24.6% of patients had 2 >BMI Z-score>-2 at time of admission. At the beginning of the study, weight loss more than 10%, and appetite loss or decreased food intake was observed in 10.8% and 20% of the study population, respectively. Median BMI percentile of patients with nutritional intervention was 8.9 (0.1–98.7) at the beginning of the study and 12.7 (0.1–98.4) at discharge time which shows a significant difference (P=0.01).

Conclusion

Medical nutrition therapy employed in this study prevented deterioration of nutritional status of children during hospitalization and was effective in stabilizing indices of nutritional status.

Nutritional Status of Children from Women with Previously Bariatric Surgery

BACKGROUND

Number of pregnancies has been increasing in women of childbearing age after the gastric bypass.

OBJECTIVE

The objective of this study was to evaluate the nutritional status of children of women submitted to gastric bypass.

METHODS

We evaluated anthropometric, breastfeeding and biochemical profile, body composition, and dietary intake indicators of children of both sexes who were born alive after the surgery. For statistical analysis, were performed Shapiro-Wilk and ANOVA test (p < 0.05).

RESULTS

The sample consisted of 13 children (61.6% female, mean age of 46 ± 22.3 months, BMI of 18.9 ± 3.3 kg/m²). The classification of BMI index by age showed that 46.1% of the children were normal weight and 30.8% obese. We observed a large percentage of children with deficiency of iron and vitamin A. 7.6 and 30.7% of children presented carbohydrate and lipid, respectively, lower than the recommendation. Fiber intake was inadequate in all children, calcium in 61.5%, vitamin A in 30.7%, and folate in 76.9% of them. Also, 84.6% presented sodium intake higher than the recommendations. The blood glucose levels were lower in children with maternal breastfeeding (65.5 ± 2.1 mg/dL, p < 0.05); furthermore, children breastfed with artificial and breast milk presented lower fat mass (3.8 ± 1.9 kg; p < 0.05).

CONCLUSION

Children from women with previously gastric bypass presented low birth weight; however, they are currently underweight or overweight and present important deficiency of iron and vitamin A and inadequate alimentary intake mainly of sodium and fibers. Breastfeeding may play a protective role in the development of obesity in these children.

Diet and Anthropometrics of Children With Inflammatory Bowel Disease: A Comparison With the General Population

BACKGROUND

There is a lack of knowledge regarding the diet of children with inflammatory bowel disease (IBD). Therefore, we investigated dietary intake in pediatric IBD compared to the general population and assessed anthropometrics and food avoidance.

METHODS

In this cross-sectional cohort study, patients younger than 18 years with IBD were included (2014-2017). Dietary intake (total energy, macro nutrients, food types) was assessed using a Food Frequency Questionnaire (FFQ) and compared with a matched reference population (n = 306).

RESULTS

There were 102 patients included (55% male, median age 15.0 years). Median height Z-score was -0.39 (interquartile range [IQR]: -1.17 to 0.26). Growth failure (height Z-scores<-1.64) was present in 11% of patients. Median BMI Z-score was 0.36 (IQR: -0.70 to 0.96). Acute malnutrition (weight-for-height Z-score<-2) was present in 3% of patients. Energy intake was lower in pediatric IBD compared to the reference population (mean kilojoule/day: 8286 vs 9794, P < 0.001). Protein intake did not differ, while fat intake was higher in pediatric IBD (mean gram/day: 101 vs 91, P < 0.001), with higher intake of vegetable oils/fats. Carbohydrate intake was lower in pediatric IBD (mean gram/day: 267 vs 305, P < 0.001), with lower intake of food types high in sugar. Food avoidance was reported in 53% of patients, with frequent avoidance of spicy (46%), high-fat food (30%), and dairy (30%).

CONCLUSIONS

The diet of children with IBD differs from the general pediatric population, with lower energy intake and high rates of food avoidance. Evaluation of the dietary intake alongside anthropometrics may be important to prevent nutrition deficiencies and promote health.

Bioelectrical Impedance Vector Analysis in Healthy Term Infants in the First Three Months of Life in Brazil

OBJECTIVE

Bioelectrical impedance vectorial analysis (BIVA) can be considered a favorable method for evaluation and monitoring of nutritional and hydration status without assumptions regarding body composition or requirement of prediction formulas. The present study aimed to determine bivariate tolerance intervals of the whole-body impedance vector for healthy term infants aged 1 to 3 months.

METHODS

This is a descriptive cross-sectional study. Anthropometric and bioelectrical impedance data (800 mA-50 kHz) were obtained. Bivariate vector analysis was conducted with the resistance-reactance (RXc) graph method. BIVA software was used to construct the graphs.

RESULTS

A total of 150 appropriate for gestational age infants (48.7% boys) who were exclusively breastfed and were 56.4 (SD = 23.1) days of age were studied. RXc tolerance ellipses (50, 75, and 95%) were constructed for boys and girls, but a general reference graph was defined for all infants considering the overlapping of ellipses between the genders. All graphs differed from those in national and foreign studies.

CONCLUSION

New reference tolerance ellipses (95, 75, and 50%) for 1- to 3-month-old infants were constructed, pointing out the need for specific reference values of total body impedance vectors in different regions of Brazil. The RXc tolerance ellipses can be used for clinical practice and provide an easy method to evaluate and monitor body composition and hydration status.

Impact of biological therapy on body composition of patients with Chron's disease

Introduction:

Protein-energy malnutrition in Crohn's disease (CD) has been reported in 20 to 92% of patients, and is associated with increased morbidity and mortality and higher costs for the health system. Anti-TNF drugs are a landmark in the clinical management, promoting prolonged remission in patients with CD. It is believed that the remission of this disease leads to nutritional recovery. The effect of biological therapy on body composition and nutritional status is unclear.

Method:

Prospective study of body assessment by bioelectrical impedance method in patients with moderate to severe CD undergoing treatment with infliximab. The main outcome was the body composition before and after 6 months of anti-TNF therapy.

Results:

There was a predominance of females (52%) with a mean age of 42±12 years. Most patients were eutrophic at baseline and remained so. There was an increase in all parameters of body composition after anti-TNF treatment: BMI (22.9±3.2 versus 25±3.8; p=0.005), waist circumference (88.1±6.7 versus 93.9±7.7; p=0.002), lean mass index (17.5±2.2 versus 18.2±2.3; p=0.000) and fat mass index (5.5±2.3 versus 6.8±2.3; p=0.000). Phase angle remained unchanged (6.2 versus 6.8; p=0.94).

Conclusion:

After therapy with IFX, all components of body composition increased, except for phase angle. The substantial increase in fat mass index and waist circumference led to concern regarding cardiovascular risk and, thus, to the need for further studies.

Phase angle assessment by bioelectrical impedance analysis and its predictive value for malnutrition risk in hospitalized geriatric patients

BACKGROUND

Phase angle (PhA) value determined by bioelectrical impedance analysis (BIA) is an indicator of cell membrane damage and body cell mass. Recent studies have shown that low PhA value is associated with increased nutritional risk in various group of patients. However, there have been only a few studies performed globally assessing the relationship between nutritional risk and PhA in hospitalized geriatric patients. The aim of the study is to evaluate the predictive value of the PhA for malnutrition risk in hospitalized geriatric patients.

METHODS

One hundred and twenty-two hospitalized geriatric patients were included in this cross-sectional study. Comprehensive geriatric assessment tests and BIA measurements were performed within the first 48 h after admission. Nutritional risk state of the patients was determined with NRS-2002. Phase angle values of the patients with malnutrition risk were compared with the patients that did not have the same risk. The independent variables for predicting malnutrition risk were determined. SPSS version 15 was utilized for the statistical analyzes.

RESULTS

The patients with malnutrition risk had significantly lower phase angle values than the patients without malnutrition risk (p = 0.003). ROC curve analysis suggested that the optimum PhA cut-off point for malnutrition risk was 4.7° with 79.6 % sensitivity, 64.6 % specificity, 73.9 % positive predictive value, and 73.9 % negative predictive value. BMI, prealbumin, PhA, and Mini Mental State Examination Test scores were the independent variables for predicting malnutrition risk.

CONCLUSIONS

PhA can be a useful, independent indicator for predicting malnutrition risk in hospitalized geriatric patients.

Nutrition assessment and its effect on various clinical variables among patients undergoing liver transplant

BACKGROUND

Malnutrition is highly prevalent in patients undergoing liver transplantation and has been associated to various clinical variables and outcome of the surgery.

METHODS

We recruited 54 adult patients undergoing living donor liver transplant (LT) as study sample. Nutrition assessment was performed by body mass index (BMI), BMI for ascites, albumin, subjective global assessment (SGA) and anthropometry [mid upper arm circumference (MUAC), mid arm muscle circumference (MAMC), and triceps skin-fold (TSF)], Hand Grip strength, and phase angle of the body. Prevalence and comparison of malnutrition was performed with various clinical variables: aetiology, Child Turcotte Pugh scores and model for end stage liver disease (ESLD) grades, degree of ascites, blood product usage, blood loss during the surgery, mortality, days [intensive care unit (ICU), Ventilator and Hospital], and Bio-impedance analysis [weight, fat mass, fat free mass (FFM), muscle mass and body fat%].

RESULTS

Assessment of nutrition status represents a major challenge because of complications like fluid retention, hypoalbuminemia and hypoproteinemia. Different nutrition assessment tools show great disparity in the level of malnutrition among ESLD patients. In the present study recipient nutrition status evaluation by different nutrition assessment tools used showed malnutrition ranging from 3.7% to 100%. BMI and anthropometric measurements showed lower prevalence of malnutrition than phase angle and SGA whereas hand grip strength showed 100% malnutrition. Agreement among nutrition assessment methods showed moderate agreement (κ=0.444) of SGA with phase angle of the body. Malnutrition by different assessment tools was significantly associated to various clinical variables except MELD and days (ICU, Ventilator and Hospital). SGA was significantly (P<0.05) associated to majority of the clinical variables like aetiology, child Turcotte Pugh grades, degree of ascites, blood product usage, blood loss during the surgery, BIA (fat mass, FFM, muscle mass and body fat%).

CONCLUSIONS

The different nutrition assessment tools showed great variability of results. SGA showed moderate agreement with phase angle of the body and was associated with various clinical and prognostic variables of liver transplantation.

Anthropometric Predictors of Bio-Impedance Analysis (BIA) Phase Angle in Healthy Adults

INTRODUCTION

Phase Angle (PhA) is a ratio of whole body reactance and resistance obtained from Bioelectrical Impedance Analysis (BIA). It indicates cellular health and integrity and is considered as prognostic tool in medical disorders. In spite of prognostic potentials of PhA, it has limited usefulness in clinical practice and in population studies because of non-availability of normal population reference limits for comparison. Moreover, it is influenced by various factors like age, sex, race and body composition (i.e. body fat, muscle mass, visceral fat, body cell mass, total body water, etc).

AIM

The aim of this study was to evaluate predictors of phase angle which will be useful in formulation of reference values for Indian population.

MATERIALS AND METHODS

BIA was performed by Tanita Body Composition Analyser on healthy adults aged 17-24 years. The inbuilt software measured the phase angle by the formula: Phase angle (PhA) = Reactance (xc)/Resistance (R)* (180/π). Phase angle values were compared across categories of age, sex, weight, height, Body Mass Index (BMI), total fat, visceral fat and muscle mass.

RESULTS

Mean value of phase angle was found to be 5.65. Phase angle was significantly (p< 0.001) higher in male than in female. Phase angle was significantly predicted from height (p< 0.001), weight (p< 0.002), muscle mass (p< 0.002) and visceral fat (p< 0.02) in multiple regression models.

CONCLUSION

Phase angle differs across anthropometric and body composition categories. Thus height, weight and muscle mass should also be taken into consideration while deriving population specific reference limits of phase angle.

Phase angle and World Health Organization criteria for the assessment of nutritional status in children with osteogenesis imperfecta

OBJECTIVE

To compare the phase angle of patients with osteogenesis imperfecta treated at a tertiary university hospital with patients in a control group of healthy children, and to assess the nutritional status of these patients through the body mass index proposed by the World Health Organization.

METHODS

Cross-sectional study carried out in a university hospital that included seven patients with osteogenesis imperfecta and a control group of 17 healthy children of the same gender and age. Weight and height were measured and bioelectrical impedance was performed. Subsequently, the phase angle was calculated based on resistance and reactance values.

RESULTS

The phase angle of the group of children with osteogenesis imperfecta was significantly lower than that of the control group (p<0.05). The body mass index criterion for age of the World Health Organization showed no difference between groups.

CONCLUSIONS

Children with osteogenesis imperfecta have a nutritional risk detected by the phase angle, which is a useful tool for nutritional screening. The calculation result could help in the diet therapy of patients with osteogenesis imperfecta.

Prevalence of child malnutrition at a university hospital using the World Health Organization criteria and bioelectrical impedance data

Malnutrition constitutes a major public health concern worldwide and serves as an indicator of hospitalized patients’ prognosis. Although various methods with which to conduct nutritional assessments exist, large hospitals seldom employ them to diagnose malnutrition. The aim of this study was to understand the prevalence of child malnutrition at the University Hospital of the Ribeirão Preto Medical School, University of São, Brazil. A cross-sectional descriptive study was conducted to compare the nutritional status of 292 hospitalized children with that of a healthy control group (n=234). Information regarding patients’ weight, height, and bioelectrical impedance (i.e., bioelectrical impedance vector analysis) was obtained, and the phase angle was calculated. Using the World Health Organization (WHO) criteria, 35.27% of the patients presented with malnutrition; specifically, 16.10% had undernutrition and 19.17% were overweight. Classification according to the bioelectrical impedance results of nutritional status was more sensitive than the WHO criteria: of the 55.45% of patients with malnutrition, 51.25% exhibited undernutrition and 4.20% were overweight. After applying the WHO criteria in the unpaired control group (n=234), we observed that 100.00% of the subjects were eutrophic; however, 23.34% of the controls were malnourished according to impedance analysis. The phase angle was significantly lower in the hospitalized group than in the control group (P<0.05). Therefore, this study suggests that a protocol to obtain patients’ weight and height must be followed, and bioimpedance data must be examined upon hospital admission of all children.

Bioelectrical Impedance of Vectorial Analysis and Phase Angle in Adolescents

OBJECTIVES

Bioelectrical impedance can be interpreted by vector analysis using direct measures of the impedance vector; thus, collecting information about resistance (R), reactance (Xc), and phase angle (PA) makes it possible to classify an individual's nutritional status. The aim of this study was to investigate these values and construct bioelectrical references for healthy Brazilian adolescents.

METHODS

This is a cross-sectional study that included 567 healthy adolescents, aged 10 to 18 years. The bioelectrical impedance was performed to collect data for R and Xc. In addition, weight and height were also collected. The PA was calculated, and thereby the tolerance and confidence ellipses were constructed using specific software.

RESULTS

For boys the mean vectors of 11 and 12 years, 12 and 13 years, 13 and 14 years, and 15 and 16 years were different from each other (p < 0.05). For girls the only mean vectors with significant differences were 11 and 12 years (p = 0.0071). The results differ from those in the literature, possibly due to ethnic differences in body composition.

CONCLUSION

The present study provides an important tool for monitoring the nutritional status of adolescents of different ages, without previous knowledge of some anthropometric measures such as body weight.

Phase Angle and Bioelectrical Impedance Vectors in Adolescent and Adult Male Athletes

The aim of the current study was to assess phase angle (PA) and bioelectrical impedance vectors (BIVA) in adolescent (n = 105, 12–19 y) and adult (n = 90, 20–50 y) male athletes practicing varied sports modalities. Bioelectrical impedance analysis (BIA) was performed with a single-frequency tetrapolar impedance analyzer after the athletes had fasted overnight for 8 h. PA and BIVA were determined from BIA data. PA presented correlations (P < .01) with body-mass index (r = .58) in all athletes and also with age in adolescent (r = .63) and adult (r = –.27) athletes. Compared with adults, adolescent athletes presented lower PA and higher frequency of PA below the 5th percentile of a reference population (P < .001). The adolescents with low PA were mostly football and basketball players. The BIVA confidence ellipses of adult and adolescent athletes were different (P < .001) between them and from their respective reference populations and were closer than those of adult and adolescent nonathletes. About 80% of the athletes were in the 95th percentile of BIVA tolerance ellipses and in quadrants consistent with adequate body cell mass and total body water. The adolescent athletes outside the 95th percentile ellipse were all football and basketball players who showed indications of decreased water retention and body cell mass and of increased water retention, respectively. PA and BIVA ellipses showed that the intense training routine of the athletes changed functional and hydration parameters and that the magnitude of these changes in adolescents may depend on the sport modality practiced.

Nutrition status and intestinal permeability in patients eligible for liver transplantation

BACKGROUND

Increased intestinal permeability has been reported in multiple studies of cirrhotic patients, although specific factors associated with this finding have not been fully elucidated. Thus, the aim of this study was to investigate whether there was an association between nutrition status measured by different methods and intestinal permeability in cirrhotic patients who were candidates for liver transplantation.

MATERIALS AND METHODS

The study group comprised 18 cirrhotic patients and 15 healthy controls. Patients' nutrition status was evaluated by Subjective Global Assessment (SGA), anthropometry, dynamometry, and phase angle, which was determined by bioelectrical impedance analysis. Intestinal permeability was assessed by the lactulose/mannitol test.

RESULTS

The prevalence of malnutrition showed wide variance between different assessment methods (5.5%-77.8%). Intestinal permeability was significantly higher in cirrhotic patients than in healthy controls. In relation to nutrition status, intestinal permeability and phase angle did not differ significantly between patients who were considered well nourished (median intestinal permeability, 0.010 [range, 0.001-0.198]; median phase angle, 6.0 [range, 4.2-6.9]) and malnourished patients (intestinal permeability, 0.032 [range, 0.002-0.079]; phase angle, 4.8 [range, 2.2-6.1]) by SGA. In addition, no correlation was found between nutrition diagnosis as assessed by different methods, patient age, liver disease severity scores, and laboratory measurements with intestinal permeability.

CONCLUSION

Although intestinal permeability was increased in cirrhotic patients, this finding was not associated with nutrition status.

Bioimpedância elétrica e gordura visceral: uma comparação com a tomografia computadorizada em adultos e idosos

OBJETIVO: Avaliar a associação entre bioimpedância elétrica (BIA) e gordura visceral (GV) em adultos e idosos. SUJEITOS E MÉTODOS: Estudo transversal, 191 indivíduos (52% mulheres, 49% idosos), estratificados por sexo, grupo etário e massa corporal. Obtiveram-se dados sobre tomografia computadorizada (área de GV) e BIA (percentual de gordura corporal total (%GCT-BIA), ângulo de fase, reactância e resistência). Análise estatística: Coeficiente de Correlação de Pearson, Anova, Qui-quadrado de Pearson, Curva ROC. RESULTADOS: Áreas de GV > 130 cm² foram mais observadas em idosos e em homens. Entre as mulheres adultas, mostrou-se correlação mais forte entre GV e %GCT-BIA. Os demais grupos apresentaram resultados semelhantes e correlações estatisticamente significantes. As correlações entre GV e ângulo de fase foram fracas e sem significância estatística. As análises da Curva ROC indicaram os seguintes %GCT-BIA que identificaram excesso de GV: homens: 21,5% (adultos), 24,25% (idosos); mulheres: 35,05% (adultas), 38,45% (idosas), com sensibilidade de 78,6%, 82,1%, 83,3%, 66,7% e especificidade de 70,6%, 62,5%, 79,1%, 69%, respectivamente. CONCLUSÃO: BIA apresentou satisfatória sensibilidade e especificidade para predizer GV, entretanto, outros aparelhos e técnicas devem ser investigados para melhorar essa predição.

Low phase angle determined by bioelectrical impedance analysis is associated with malnutrition and nutritional risk at hospital admission

BACKGROUND & AIMS

This study determined the association between phase angle (PhA), by bioelectrical impedance analysis (BIA) and nutritional risk by Nutritional Risk Screening (NRS-2002), Subjective Global Assessment (SGA), hospital length of stay (LOS) and 30 day non-survival in patients at hospital admission compared to healthy controls.

METHODS

PhA was determined by BIA in patients (n = 983, 52.7 ± 21.5 yrs, M 520) and compared to healthy age-, sex- and height-matched controls. Low PhA was set at <5.0° (men) and <4.6° (women) as previously determined (Kyle, in press).

RESULTS

PhA was lower in patients (men 6.0 ± 1.4°, women 5.0 ± 1.3°) than controls (men 7.1 ± 1.2°, women 6.0 ± 1.2°, un-paired t-test p < 0.001). Patients were more likely to have low PhA than controls: NRS-2002: no risk (relative risk (RR) 1.7, 95th confidence interval (CI) 1.2-2.3), moderate risk (RR 4.5, CI 3.4-5.8) and severe risk (RR 7.5, CI 5.9-9.4); similar results were obtained by SGA; LOS ≥21 days (RR 6.9, CI 5.1-9.1) and LOS 5-20 days (RR 5.2, CI 3.9-6.9) and non-survivors (RR 3.1, CI 2.1-3.4) compared to survivors.

CONCLUSIONS

There is a significant association between low PhA and nutritional risk, LOS and non-survival. PhA is helpful to identify patients who are at nutritional risk at hospital admission in order to limit the number of in-depth nutritional assessments.

Lean body mass, physical activity and quality of life in paediatric patients with inflammatory bowel disease and in healthy controls

BACKGROUND AND AIMS

Physical activity is important for muscle and bone strength in the growing child and may be impaired in paediatric patients with inflammatory bowel disease (IBD) even during quiescent disease. The SenseWearPro(2) armband allows to measure physical activity under everyday life conditions.

METHODS

Thirty-nine IBD patients (27 Crohn's disease, 12 ulcerative colitis, 24 boys) in remission (n=26) or with only mild disease activity (n=13) were compared to 39 healthy age and sex-matched controls. Body weight, height, body mass index (BMI), lean body mass as phase angle α (determined by bioelectrical impedance analysis), and dynamometric grip force were expressed as age- and sex-related Z-scores. SenseWearPro(2) armbands were applied for three consecutive days to record number of steps, duration of physical activity and sleeping time. Quality of life was assessed with the German KINDL and IMPACT III questionnaires, energy intake with prospective food protocols. Differences between patients and pair-matched controls were analysed by paired t-test.

RESULTS

Patients showed lower Z-scores for phase angle α (difference -0.72; 95% CI [-1.10; -0.34]) and lower grip strength (-1.02 [-1.58; -0.47]) than controls. They tended towards lesser number of steps per day (-1339 [-2760; 83]) and shorter duration of physical activity (-0.44 h [-0.94; 0.06]), particularly in females and patients with mild disease. Quality of life and energy intake did not differ between patients and controls.

CONCLUSION

In spite of quiescent disease lean body mass and physical activity were reduced. Interventions to encourage physical activity may be beneficial in this lifelong disease.

Bioelectrical phase angle and impedance vector analysis--clinical relevance and applicability of impedance parameters

BACKGROUND & AIMS

The use of phase angle (PhA) and raw parameters of bioelectrical impedance analysis (BIA) has gained attention as alternative to conventional error-prone calculation of body composition in disease. This review investigates the clinical relevance and applicability of PhA and Bioelectrical Impedance Vector Analysis (BIVA) which uses the plot of resistance and reactance normalized per height.

METHODS

A comprehensive literature search was conducted using Medline identifying studies relevant to this review until March 2011. We included studies on the use of PhA or BIVA derived from tetrapolar BIA in out- and in-patient settings or institutionalized elderly.

RESULTS

Numerous studies have proven the prognostic impact of PhA regarding mortality or postoperative complications in different clinical settings. BIVA has been shown to provide information about hydration and body cell mass and therefore allows assessment of patients in whom calculation of body composition fails due to altered hydration. Reference values exist for PhA and BIVA facilitating interpretation of data.

CONCLUSION

PhA, a superior prognostic marker, should be considered as a screening tool for the identification of risk patients with impaired nutritional and functional status, BIVA is recommended for further nutritional assessment and monitoring, in particular when calculation of body composition is not feasible.