Bioelectrical impedance phase angle and nutritional status in children with intestinal failure on prolonged parenteral nutrition

Abstract Objective To compare the phase angle (PhA) through bioelectrical impedance (BIA) of children with intestinal failure (IF) using prolonged parenteral nutrition (PN) followed by an Intestinal Rehabilitation Program, with a control group. Methods Children under 10 years of age with IF using prolonged PN for >60 days (study group) were included. The control group consisted of healthy children without chronic pathologies, matched by sex and age. Anthropometric parameters evaluated were: weight, height, weight/age z-score (W/A), height/age z-score (H/A), BMI, BMI/A z-score, arm circumference, triceps skinfold, subscapular skinfold, mid-arm muscle circumference. BIA parameters were resistance (R), reactance (Xc), and phase angle (PhA). Results Twenty-eight children were included in the study group, median (IQR) age was 11 (8-27) months, 53.6 % were male. In the control group, 28 children were included, median (IQR) age was 12.5 (8-24.7) months, 50 % were male. Children from the study group had W/A z-scores and H/A z-scores significantly lower than controls. There was no significant difference between PhA in the study group and controls, [median (IQR) 4.3° (3.8;4.6) vs 4.0° (3.8;5.4) respectively, p = 0.980]. Prematurity was significantly higher in the study group than in the controls, but there was no significant correlation between gestational age at birth and PhA of the children from the study group. Conclusion Children with IF using prolonged PN showed lower W/A and H/A compared to the control group, but without significant difference between the PhA of children with IF compared to controls.

Association between longitudinal changes in phase angle and mortality rate in adults critically ill with COVID-19: A retrospective cohort study.

BACKGROUND: Phase angle (PhA) obtained by bioelectrical impedance analysis (BIA) works as a predictor of clinical outcomes. Specific cutoff values for longitudinal changes and their relationship with clinical outcomes are still undetermined for patients with critical illness. Thus, the aim of this study was to analyze the association between longitudinal changes in PhA during intensive care unit (ICU) stay and all-cause 90-day mortality in patients critically ill with COVID-19. METHODS: This was a retrospective cohort study of adults critically ill with COVID-19 undergoing invasive mechanical ventilation with a length of stay >14 days. BIA was performed at ICU admission and at days 7 and 14 of ICU stay; PhA and hydration parameters were collected. Differences between survivors and nonsurvivors were assessed. Longitudinal changes were evaluated using repeated-measures analysis of variance. A receiver operating characteristics curve for PhA declined (%) during the first 14 days, and all-cause 90-day mortality was performed. Survival probability was reported using hazard ratios (HR). RESULTS: One-hundred nine patients were included. The change in the value of PhA was close to 17.1%. Nonsurvivors had a higher prevalence of individuals with a decrease in PhA >22.2% (area under the curve = 0.65) in the first 14 days in comparison with survivors (70% vs 34.8%, P < 0.01). PhA decrease >22.2% at 14 days was a significant predictor of all-cause 90-day mortality (HR = 2.2, 95% CI 1.71-3.6, P = 0.04). CONCLUSION: Changes in PhA are associated with all-cause 90-day mortality. Future studies should be directed to interventions to prevent changes in this nutrition marker.

Agreement Between Bioelectrical Impedance Analysis and Dual-Energy X-ray Absorptiometry to Estimate Fat Mass in Hispanic Adults With Type 2 Diabetes Mellitus: A Cross-Sectional Study.

Background: Adipose tissue excess is associated with adverse health outcomes, including type 2 diabetes. Body mass index (BMI) is used to evaluate obesity but is inaccurate as it does not account for muscle mass, bone density, and fat distribution. Accurate measurement of adipose tissue through dual-energy X-ray absorptiometry (DXA) and computed axial tomography (CT) is crucial for managing and monitoring adiposity-related diseases. Still, these are not easily accessible in most hospitals in Mexico. Bioelectrical impedance analysis (BIA) is non-invasive and low-cost but may not be reliable in conditions affecting the body's hydration status, like diabetes. Objectives: To assess fat mass concordance between BIA and DXA in Hispanic-American adults with type 2 diabetes mellitus (T2DM). Methods: Cross-sectional study of a non-probabilistic sample of subjects over 18 years with type 2 diabetes. We used DXA as the reference method. Results: We evaluated the accuracy of FM estimation through BIA and DXA in 309 subjects with type 2 diabetes. Results showed a trend of overestimating the diagnosis of obesity using BIA, especially in individuals with a higher fat mass index (FMI). At the group level, we found BIA accurate; however, at the individual level, it is not. The bias between the 2 methods showed a statistically significant overestimation of body fat by BIA (P ⩽ .01) in both sexes. BIA demonstrated high precision in estimating fat mass. We were able to provide a correction factor of 0.55 kg in men. Conclusion: BIA is inaccurate compared to DXA for body composition assessment in patients with diabetes. Inaccurate measurements can result in misclassification. However, BIA is precise for body composition assessment in patients with diabetes, so it is reliable for tracking patient progress over time.

Agreement between bioelectrical impedance analysis and dual-energy X-ray absorptiometry to estimate fat mass in adults with type 2 Diabetes Mellitus This study compares 2 methods for measuring body composition in patients with diabetes in Mexico. The first method is Bioelectrical Impedance Analysis (BIA), which is non-invasive, low-cost, and easy to use but may not be reliable in conditions that affect the body's hydration status, like diabetes. The second method is Dual-energy X-ray Absorptiometry (DXA), which is more accurate but less easily accessible. The study was a cross-sectional evaluation of 309 participants over 18 years with type 2 diabetes mellitus (T2DM) by HbA1C levels. The present study found BIA to be precise for body composition assessment but not accurate compared to DXA as the reference method. The study showed a trend of overestimating the diagnosis of obesity using BIA, especially in individuals with a higher fat mass index. This study found BIA is accurate at the group level but not at the individual level. The bias between the 2 methods showed a statistically significant overestimation of body fat by BIA. We provided a correction factor of 0.55 kg in men but not women. BIA is not ideal for diagnosing obesity but is reliable for tracking patient progress over time.

Longitudinal Links between Changes in Body Composition and Liver Disease Severity in Children and Adolescents with Metabolic Dysfunction-Associated Steatotic Liver Disease.

OBJECTIVE: To investigate the relationship between longitudinal changes in body composition and liver disease severity in children with metabolic dysfunction-associated steatotic liver disease (MASLD). STUDY DESIGN: This longitudinal, single-center, retrospective analysis included patients aged <20 years followed for MASLD who had had ≥2 bioelectrical impedance analyses (BIAs) performed. MASLD regression was defined as alanine aminotransferase (ALT) normalization or a decrease of >50% from baseline. Fat and skeletal muscle mass were adjusted for size by calculating respective indices (dividing by height2). Logistic and linear regressions were used to determine the independent relationship between changes in body composition over time and serological markers of liver disease severity. RESULTS: We included 258 patients (75% male, 50% Hispanic) with a median age of 14 years (IQR, 11-16 years) at the time of first BIA. Median body mass index (BMI) z-score at baseline was 2.33 (IQR, 2.04-2.62). Median time from first to last BIA was 12 months (IQR, 6-24 months). A decrease in fat mass index was independently associated with reductions in ALT and gamma glutamyl transferase and increased odds of MASLD regression (OR; 0.55; P < .001). Fat mass index reduction was superior to BMI z-score in predicting MASLD regression. Change in skeletal muscle mass index was not associated with change in ALT or gamma glutamyl transferase. CONCLUSIONS: Changes in fat mass, not skeletal muscle mass, are associated with serological markers of liver injury in youth with MASLD. Fat mass changes outperform BMI z-score changes in predicting MASLD regression. BIA can serve as an adjunct biomarker of liver disease progression.

Phase angle is a predictor of overall 5-year survival after head and neck cancer surgery.

OBJECTIVE: To evaluate the ability of the variables Muscle Mass percentage (%MM), Body Fat percentage (%BF), Phase Angle (PhA), and Standardized Phase Angle (SPhA) to predict overall survival rates in individuals with surgically treated HNC. METHODS: A prospective cohort study of surgically treated HNC patients was carried out between 2017 and 2022 at a cancer referral center in Feira de Santana, Bahia. All subjects were seen by an experienced dietitian the week before surgery. During this visit, patients had their sociodemographic and clinical data collected, as well as anthropometric measurements (weight and height) and BIA variables. In this study, postoperative overall 5-year survival was defined as the time in months between the date of surgery and the date of death, regardless of the cause of death. Patients were followed up after surgery until death. RESULTS: Seventy-eight older adult patients were consecutively included. Patients had a median age of 65.5-years, were mostly men (83.3%), and most had low education levels (62.3%) and low household income, ranging from zero (19.2%) to the minimum wage (60.2%). They were mostly alcohol drinkers (91%) and tobacco smokers (87.2%). Glottic cancer was diagnosed in 48.7% of patients, with 44.8% of cases with stage-IV disease. Forty (51.2%) deaths were recorded in the follow-up period, with a median survival time of 39 months. Variables %MM, %BF, and SPhA were not significantly different between groups (alive vs. dead patients). PhA was considered an independent predictor of overall survival, with an accuracy of 69% (95% CI 0.57‒0.80). When comparing survival curves, patients with a preoperative PhA < 6.8° were more than twice as likely to die during follow-up (HR = 2.38; p =  0.02; 95% CI 1.14‒4.97). CONCLUSION: Out of the assessed BIA variables, preoperative PhA was considered a good predictor of overall survival after HNC surgery.

Bioelectrical Impedance Vectors Analysis of Sarcopenic Older Adults Submitted to a Resistance Training Program.

The objective of the present study is to analyze the changes in bioimpedance vector analysis (BIVA) and phase angle (PhA) in sarcopenic older people submitted to a 12-week resistance training (RT) program according to classic and specific analyses. To this end, 20 sarcopenic older adults of both sexes, invited through media, underwent bioimpedance analysis before and after the RT carried out three times a week, for 12 weeks. The mean impedance vectors of the groups established for the confidence ellipses (95% of the confidence ellipse) are compared using Hotelling's T2 test. The distance D from Mahalanobis is also calculated. Classic and Specific BIVA are presented. The resistance values for the classical analyses (R/H) decreased across all groups (whole group, women and men, p < 0.05), with approximate decreases ranging from 9.4% to 10%, while the classic reactance (Xc/H) decreased (p < 0.05) only for the whole group (5.9%) and men (7.7%). For the specific BIVA, trends are verified for the whole sample, with a decrease in resistance (R.sp) and an increase in reactance (Xc.sp). In conclusion, the RT program in sarcopenic individuals promoted a reduction in resistance values in classical analyses, indicating a possible increase in hydration status and, consequently, musculoskeletal mass.

Phase Angle and Body Composition as Predictors of Fitness and Athletic Performance in Adolescent Boxers.

BACKGROUND: Phase angle (PhA) is an indicator of cellular health, function, and integrity. PhA has been considered an indicator of nutritional and health status, but it is uncertain whether it could be used as a fitness or athletic performance indicator. OBJECTIVE: To analyze the relationship between PhA and the fitness and athletic performance of adolescent boxers and to know whether this association is independent of body composition. METHODS: Thirty-seven trained youth boxers (15-18 y old) participated in the study. Participants underwent anthropometry and bioelectrical impedance assessments. The following tests were conducted: Fitness-Gram battery; speed, agility, and quickness; ball throws; punch impact force; bench press maximal strength; and vertical and horizontal jumps. Linear regression models were estimated and adjusted by covariates. RESULTS: The PhA was related to upper-limb strength. Nevertheless, in linear regression models, after adjusting models by body composition, only PhA remained as a predictor of relative maximal strength. The PhA was not a predictor of speed, agility, and quickness; cardiorespiratory fitness; or lower-limb power, in which adiposity was the main predictor of fitness. CONCLUSIONS: In adolescent boxers, PhA can predict upper-limb maximal strength independently of bioelectrical impedance analysis premises. However, compared with mucle mass, PhA is not a better predictor of upper-limb maximal strength.

Practical but Inaccurate? A-Mode Ultrasound and Bioelectrical Impedance Underestimate Body Fat Percentage Compared to Dual-Energy X-ray Absorptiometry in Male College Students.

Bioelectrical impedance (BIA) and ultrasound (US) have become popular for estimating body fat percentage (BF%) due to their low cost and clinical convenience. However, the agreement of these devices with the gold-standard method still requires investigation. The aim was to analyze the agreement between a gold-standard %BF assessment method with BIA and US devices. Twenty-three men (aged 30.1 ± 7.7 years, weighing 82.5 ± 14.9 kg, 1.77 ± 0.05 m tall) underwent dual-energy X-ray absorptiometry (DXA), BIA (tetrapolar) and US (three-site method) %BF assessments. Pearson and concordance correlations were analyzed. A T-test was used to compare the means of the methods, and Bland-Altman plots analyzed agreement and proportional bias. Alpha was set at <0.05. The Pearson coefficients of BIA and US with DXA were high (BIA = 0.94; US = 0.89; both p < 0.001). The concordance coefficient was high for BIA (0.80) and moderate for US (0.49). The BF% measured by BIA (24.5 ± 7.5) and US (19.4 ± 7.0) was on average 4.4% and 9.6% lower than DXA (29.0 + 8.5%), respectively (p < 0.001). Lower and upper agreement limits between DXA and BIA were -1.45 and 10.31, while between DXA and US, they were 2.01 and 17.14, respectively. There was a tendency of both BIA (p = 0.09) and US (p = 0.057) to present proportional bias and underestimate BF%. Despite the correlation, the mean differences between the methods were significant, and the agreement limits were very wide. This indicates that BIA and US, as measured in this study, have limited potential to accurately measure %BF compared to DXA, especially in individuals with higher body fat.

Associations of upper- and lower-limb muscle strength, mass, and quality with health-related quality of life in community-dwelling older adults.

AIM: This study aimed to investigate the associations between upper- and lower-limb muscle strength, mass, and quality and health-related quality of life (HRQoL) among community-dwelling older adults. METHODS: A cross-sectional study was conducted with 428 Brazilian community-dwelling older adults aged 60 to 80 years. Upper- and lower-limb muscle strength were evaluated through the handgrip strength (HGS) test and the 30-s chair stand test, respectively. Muscle mass was assessed by dual-energy X-ray absorptiometry (DXA) and bioelectrical impedance analysis (BIA). Muscle quality was evaluated using the muscle quality index (MQI). HRQoL was assessed using the World Health Organization Quality of Life Brief Version questionnaire. RESULTS: Lower-limb, but not upper-limb, muscle strength and quality were independently associated with HRQoL, particularly within the domains of physical capacity, environment, and overall HRQoL for both males and females (P < 0.05). DXA- and BIA-derived analyses provided similar results in relation to muscle mass and muscle quality. CONCLUSIONS: Lower-limb, but not upper-limb, muscle strength and quality were independently associated with HRQoL among community-dwelling older adults. Moreover, the results obtained from both BIA and DXA were similar, highlighting that BIA can serve as a viable surrogate method for estimating body composition in resource-limited clinical settings. Geriatr Gerontol Int 2024; 24: 683-692.

Fat-free mass predictive equation using multifrequency bioelectrical impedance data in adolescent soccer athletes: development and cross-validation.

OBJECTIVES: This study aimed to develop and cross-validate a fat-free mass (FFM) predictive equation using multifrequency bioelectrical impedance analysis (BIA) data in adolescent soccer athletes. METHODS: Male adolescent soccer athletes (n = 149; 13-19 y old) were randomly sorted using Excel and independently selected for development group (n = 100) or cross-validation group (n = 49). The FFM reference values were determined using dual-energy X-ray absorptiometry. Single-frequency BIA was used to plot tolerance ellipses. Multifrequency-BIA raw data were used as independent variables in regression models. Student's independent t-test was used to compare development and cross-validation groups. Stepwise multiple regression was used to develop the FFM predictive equation. Bland-Altman plots, Lin's concordance correlation coefficient, according to McBride criteria, precision, accuracy, and standard error of estimate (SEE) were calculated to evaluate the concordance and reliability of estimates. Bioelectrical impedance vector analysis was plotted to assess hydration status. RESULTS: No differences (P > 0.05) were observed between development and validation groups in chronological age, anthropometric data, bioelectrical impedance data, and FFM values obtained using dual-energy X-ray absorptiometry. Bioelectrical impedance vector analysis tolerance showed that all participants presented adequate hydration status compared to the reference population. The new FFM predictive equation developed and validated: FFM (kg) = -7.064 + 0.592 × chronological age (y) + 0.554 × weight (kg) + 0.365 × height²/resistance (cm²/Ω), presented R² = 0.95; SEE = 1.76 kg; concordance correlation coefficient = 0.95, accuracy = 0.98, and strength of concordance = 0.99. CONCLUSIONS: The present study developed and cross-validated an FFM predictive equation based on multifrequency bioelectrical data providing substantial FFM accuracy for male adolescent soccer athletes.

Skeletal muscle mass obtained by anthropometric equation and presence of sarcopenia in postmenopausal women.

Objective: To analyze the amount of muscle and the presence of sarcopenia in postmenopausal women using different methods, verifying the agreement between them as to skeletal muscle mass (SMM). Methods: This cross-sectional observational study was conducted with postmenopausal women aged ≥ 50 years. SMM was obtained from a predictive equation, Bioelectrical Impedance (BIA), and Dual Energy X-Ray Absorptiometry (DXA). The skeletal muscle mass index (SMI) and the appendicular skeletal muscle mass index (ASMI) were calculated. The cut-off point of SMI was determined for the population itself. The agreement between the SMI obtained using the different methods was verified. Sarcopenia was diagnosed according to the criteria proposed by the European Working Group on Sarcopenia in Older People 2 (EWGSOP2). The significance level adopted for all tests was 5.0%. Results: A total of 112 women were evaluated, with an average age of 66.1 ± 5.65 years. Among them, 51.8% were sufficiently active and 43.8% were overweight and obese. The SMI cut-offs were 6.46 kg/m2 for the predictive equation and 7.66 kg/m2 for BIA, with high sensitivity and specificity. There was an excellent agreement in the identification of SMM by the predictive equation (0.89 [0.824-0.917], p < 0.001) and BIA (0.92 [0.883-0.945], p < 0.001), in reference to DXA. The prevalence of sarcopenia was 0.9%, 1.8%, and 2.7% according to BIA, DXA, and the predictive equation, respectively. Conclusion: The predictive equation showed the expected agreement in estimating skeletal muscle mass in postmenopausal women, offering a viable and accurate alternative.

Bioelectrical impedance phase angle and nutritional status in children with intestinal failure on prolonged parenteral nutrition.

OBJECTIVE: To compare the phase angle (PhA) through bioelectrical impedance (BIA) of children with intestinal failure (IF) using prolonged parenteral nutrition (PN) followed by an Intestinal Rehabilitation Program, with a control group. METHODS: Children under 10 years of age with IF using prolonged PN for >60 days (study group) were included. The control group consisted of healthy children without chronic pathologies, matched by sex and age. Anthropometric parameters evaluated were: weight, height, weight/age z-score (W/A), height/age z-score (H/A), BMI, BMI/A z-score, arm circumference, triceps skinfold, subscapular skinfold, mid-arm muscle circumference. BIA parameters were resistance (R), reactance (Xc), and phase angle (PhA). RESULTS: Twenty-eight children were included in the study group, median (IQR) age was 11 (8-27) months, 53.6 % were male. In the control group, 28 children were included, median (IQR) age was 12.5 (8-24.7) months, 50 % were male. Children from the study group had W/A z-scores and H/A z-scores significantly lower than controls. There was no significant difference between PhA in the study group and controls, [median (IQR) 4.3° (3.8;4.6) vs 4.0° (3.8;5.4) respectively, p = 0.980]. Prematurity was significantly higher in the study group than in the controls, but there was no significant correlation between gestational age at birth and PhA of the children from the study group. CONCLUSION: Children with IF using prolonged PN showed lower W/A and H/A compared to the control group, but without significant difference between the PhA of children with IF compared to controls.

Body fat predicts urinary tract infection in kidney transplant recipients: a prospective cohort study.

BACKGROUND: The association between obesity and infectious diseases is increasingly reported in the literature. There are scarce studies on the association between obesity and urinary tract infection after kidney transplantation (KTx). These studies defined obesity based on body mass index, and their results were conflicting. The present study aimed to evaluate this association using bioelectrical impedance analysis for body composition evaluation, and obesity definition. METHODS: A single-center cohort study was conducted. Demographic, clinical, anthropometric, and laboratory data were collected at KTx admission, and bioelectrical impedance analysis was performed to measure the visceral fat area, waist circumference, and total fat mass. The occurrence of urinary tract infection (symptomatic bacteriuria and/or histological evidence of pyelonephritis) was evaluated within three months after KTx. RESULTS: Seventy-seven patients were included in the cohort, and 67 were included in the final analysis. Urinary tract infection was diagnosed in 23.9% of the transplanted patients. Waist circumference (HR: 1.053; 95% CI 1.005-1.104; p = 0.032), visceral fat area (HR: 1.015; 95% CI 1.003-1.027; p = 0.014), and total fat mass (HR: 1.075; 95% CI 1.008-1.146; p = 0.028) were associated with urinary tract infection occurrence after KTx, using Cox regression models. Patients with high waist circumference (above 102 cm for men and above 88 cm for women) had a 4.7 times higher risk of a urinary tract infection than those with normal waist circumference (HR: 4.726; 95% CI 1.267-17.630; p = 0.021). Kaplan-Meier curves showed that patients with high waist circumference, high visceral fat area, and high total fat mass had more urinary tract infections (Log-rank test p = 0.014, p = 0.020, and p = 0.018, respectively). Body mass index was not able to predict urinary tract infection in the study sample. CONCLUSIONS: Waist circumference, visceral fat area, and total fat mass, assessed by bioelectrical impedance analysis, were predictors of urinary tract infection risk within the first three months after KTx.

Standing-Long-Jump Test Application in Identifying Female Adolescents at Risk of Sarcopenic Obesity / Aplicación de la Prueba de Salto de Longitud de Pie para Identificar a Adolescentes con Riesgo de Obesidad Sarcopénica

SUMMARY: The identification of children and adolescents who are at risk of sarcopenic obesity development often requires specialized equipment and expensive test procedures. Therefore, the establishment of cheaper and faster methods would be greatly useful, especially if they could be applied in the field. The study's objective was to establish if identification of female adolescents who suffer the risk of developing sarcopenic obesity can be obtained through the standing-long-jump test application. To achieve the research objectives, various anthropometric and body composition measurements were performed and lower limb explosive strength was assessed using the standing long jump fitness test. The research was conducted on a sample of 535 female respondents randomly selected from 9 elementary schools in the Skopje region of the Republic of North Macedonia. The respondents were divided into quintiles according to BMI z-scores, and the arithmetic means and SD about muscle-to-fat ratio were calculated for each quintile. The cutoff was determined based on the mean and standard deviation of the muscle-to-fat ratio for the 3rd quintile of BMI and the percentage of respondents with sarcopenic obesity was examined. The optimal cut-off value of the long jump fitness test results for predicting sarcopenic obesity in an adolescent girl showed that the area under the ROC curve was 0.781 (95 % CI 0.743-0.815). The standing-long-jump test values, on grounds of odds ratio (OR 95 % CI) about the girls at risk of sarcopenic obesity development, which was identified on muscle-to-fat ratio base, were 8.76 (4.39 - 17.54, p 0.001). It can be used to predict sarcopenic obesity presence in female adolescents, which can be vital in case of health intervention.

La identificación de niños y adolescentes que corren riesgo de desarrollar obesidad sarcopénica a menudo requiere equipos especializados y procedimientos de pruebas costosos. Por lo tanto, el establecimiento de métodos más baratos y rápidos sería de gran utilidad, especialmente si pudieran aplicarse en el campo. El objetivo del estudio fue establecer si la identificación de mujeres adolescentes que sufren riesgo de desarrollar obesidad sarcopénica se puede obtener mediante la aplicación de la prueba de salto de longitud de pie. Para lograr los objetivos de la investigación, se realizaron diversas mediciones antropométricas y de composición corporal y se evaluó la fuerza explosiva de los miembros inferiores mediante la prueba de aptitud de salto de longitud de pie. La investigación se realizó con una muestra de 535 mujeres encuestadas seleccionadas al azar de 9 escuelas primarias de la región de Skopje, en la República de Macedonia del Norte. Los encuestados se dividieron en quintiles según las puntuaciones z del IMC, y se calcularon las medias aritméticas y la DE sobre la relación músculo-grasa para cada quintil. El límite se determinó en función de la media y la desviación estándar de la relación músculo-grasa para el tercer quintil del IMC y se examinó el porcentaje de encuestados con obesidad sarcopénica. El valor de corte óptimo de los resultados de la prueba de condición física de salto de longitud para predecir la obesidad sarcopénica en una adolescente mostró que el área bajo la curva ROC fue 0,781 (IC del 95 %: 0,743-0,815). Los valores de la prueba de salto de longitud de pie, sobre la base del odds ratio (OR IC del 95 %) sobre las niñas en riesgo de desarrollar obesidad sarcopénica, que se identificó sobre la base del ratio músculo-grasa, fueron 8,76 (4,39 - 17,54, p. 0,001). Puede utilizarse para predecir la presencia de obesidad sarcopénica en adolescentes, lo que puede ser vital en caso de intervención sanitaria.

One-Year Changes in Bioelectrical Impedance Data in Adolescent Athletes.

Raw bioelectrical impedance (BI) data and vector analysis (BIVA) have been used to evaluate fat-free mass (FFM) cross-sectionally in adolescent athletes; however, there have been no longitudinal studies about it. This study aimed to assess the magnitude of changes in raw BI data (resistance [R], reactance [Xc], and phase angle [PhA]), BIVA, and FFM in adolescent athletes (n = 137, 40% female). BI data were collected using a single-frequency device at baseline and after one year of sports practice. Baseline chronological age categorized the participants (11, 12, or 13 years [y]). In females, Xc/H increased (13 to 14 y, p = 0.04) while R/H decreased in all age groups (p = 0.001). PhA (11 to 12 y, p = 0.048) and FFM (11 to 12 y and 12 to 13 y groups p = 0.001) increased and showed the lowest magnitude of changes in the 13 to 14 y group (p = 0.05). In males, Xc/H decreased (11 to 12 and 12 to 13 y groups, p = 0.001) with a higher magnitude of changes in the 13 to 14 y group (p = 0.004); R/H decreased (p = 0.001); FFM increased in all groups (p = 0.001); however, no magnitude of changes was observed. PhA increased in the 13 to 14 y group (p = 0.004). BIVA showed no differences among ellipse distances in females. In males, a high distance was observed in the 11 to 12 y group. "Time interval" influenced PhA and Xc/H in the female group and R/H and Xc/H in the male group. "Initial age" and "time interval" influenced the increase in PhA in the male group. Raw BI data and BIVA patterns can detect the magnitude of the changes in a sex-dependent manner.

Prognostic value of overhydration and bioelectrical impedance vector on short- and long-term outcomes in hospitalized patients with cancer.

BACKGROUND & AIMS: Water, an essential component of body composition, appears to be a significant predictor of adverse outcomes in clinical populations, despite being frequently underexplored. Bioelectrical impedance analysis (BIA) and vector analysis (BIVA) are easy and cost-effective bedside tools for estimating body composition, particularly water content. Therefore, our study aimed to assess the impact of hydration and fluid status using both BIA and BIVA on outcomes in hospitalized patients with cancer. METHODS: A prospective cohort study involving hospitalized individuals with cancer was conducted. Total body water (TBW) was estimated using BIA. Extracellular-water/TBW (ECW/TBW) and ECW/intracellular-water (ECW/ICW) ratios were calculated. BIVA ellipses vectors were constructed to enhance our analysis of hydration status. Participants were followed during their hospital stay and up to six months after discharge to assess outcomes, including in-hospital mortality, 6-month non-elective rehospitalization, and 6-month mortality. RESULTS: TBW, ECW/TBW, ECW/ICW ratios, and BIVA plots were not associated with non-elective rehospitalization during the follow-up period. However, TBW and an elevated ECW/ICW ratio were independent predictors of in-hospital mortality [hazard ratio (HR): 1.07 (1.01; 1.13) p = 0.020; HR: 4.23 (1.69; 10.58) p = 0.002]. Elevated ratios ECW/TBW and ECW/ICW were independent predictors of 6-month mortality [HR: 1.87 (1.10; 3.21) p = 0.022; HR: 2.49 (1.37; 4.51) p = 0.003]. BIVA vectors for in-hospital and 6-month mortality shifted significantly to the right, leading to cachexia and overhydration quadrants (p < 0.05). CONCLUSION: Abnormalities related to overhydration were important predictors of short- and long-term mortality in hospitalized patients with cancer.

Exploring the Impact of Protein Supplement Source on Body Composition in Women Practicing Anaerobic Resistance Exercise: A Pilot Study.

Supplements based on protein hydrolysates have been used as an effective source to access amino acids with greater bioavailability, promoting absorption to improve body composition. Five groups of young women were randomly selected. They followed a personalized eating plan that included different protein supplements (meat, vegan, branched-chain amino acids [BCAAs], whey, and control group), combined with an exercise plan, for eight weeks, aiming to assess their consumption effects combined with resistance exercise on body composition. Bioelectrical impedance before and after the treatment was conducted. The results showed that the supplementation with BCAAs presented a significant decrease (p < 0.05) on the BMI in this group (initial BMI = 19.7 kg/m2; final BMI = 19.4 kg/m2). When comparing the final measures among the groups, the BCAAs and vegan supplements caused a significant decrease in body weight (50.24 kg and 51.34 kg, respectively). The BMI of the group supplemented with meat proteins was statistically higher (22.06 kg/m2) than that the group supplemented with BCAAs (19.4 kg/m2) (p < 0.05). No significant changes were observed in the type of protein consumed to produce muscle mass in the participants after eight weeks of study under a controlled diet and anaerobic resistance exercise. Participants exhibited energy deficiencies, but their macronutrient distribution appeared normal. Following an 8-week intervention, meat and BCAAs reduced weight and BMI, although no statistical differences were observed. It is recommended to extend the treatment for a more comprehensive understanding.

Muscle mass evaluation in hospitalized patients: Comparison between doubly indirect methods.

BACKGROUND: Loss of muscle mass (MM) in hospitalized patients has been associated with negative outcomes, thus, evaluating this biomarker is important to stratify risk. Although studies have been showing that calf circumference (CC) and bioelectrical impedance analysis (BIA) are valid for estimating MM in hospitalized patients, we do not know if they are associated. The aim of this study was to evaluate the associations between CC and BIA in hospitalized patients. METHODS: A cross-sectional study, in hospitalized patients' post-acute cardiac event. We collected sociodemographic, clinical, and anthropometric data. CC measurement was adjusted according to the BMI. Spearman's correlations and associations between the methods were performed for the total sample, according to sex and stage of life (older adults or not). RESULTS: We included 177 patients, mean age of 60.5 ± 12.4 years old, the majority males (75 %). Median BMI was 26.2 kg/m2 (23.8-29.2 kg/m2), most of them overweight (41.8 %). The median of CC was lower in females and older adults, and majority of the patients had low CC (87.6 %). Higher values of fat-free mass (FFM) by BIA were observed in males and younger adults, and 5.6 % presented low FFMI. We found a positive and moderate correlation between fat-free mass index (FFMI) and CC (rho = 0.532). Males had higher correlations (rho = 0.481). An increase of 1 kg in the FFM represented an increase of 1.16 cm (crude analysis) to 1.59 cm (adjusted analysis) in CC (p < 0.001). FFM explained 37 % in the variability of CC, and together with BMI, sex and age, explained 60 % in the variability. CONCLUSIONS: Raw values of FFM obtained by BIA and CC presented a weak to moderate correlation in cardiac patients. Changes in one measure impact on the other one.

Bioelectrical impedance vector analysis is different according to the comorbidity burden in post-acute myocardial infarction.

BACKGROUND: The prevalence of a high comorbidity burden in patients who suffered an acute myocardial infarction (AMI) is increasing with the aging population, and the nutrition status also may be a predictor of clinical outcomes for these patients. This study aimed to investigate the relationship between the comorbidity burden and the characteristics of the bioelectrical impedance vector analysis (BIVA) in patients post-AMI. METHODS: This prospective observational cohort study was conducted with adult patients who were hospitalized with AMI. Pre-existing comorbidities were assessed by the Charlson comorbidity index (CCI) adjusted by age, and anthropometric and BIVA characteristics were evaluated after the hemodynamic stabilization. All patients were followed-up until hospital discharge, and their length of stay was observed. RESULTS: A total of 184 patients (75% were males; mean age, 60.2 ± 12.3 years) were included. The most common comorbidities were dyslipidemia (73.9%), hypertension (62%), and type 2 diabetes (34.2%). A higher CCI (≥3) was associated with sex (P = 0.008) and age (P < 0.001). Regarding BIVA, statistically significant differences were detected between sex (P < 0.001), age (P < 0.001), and CCI (P = 0.003), with longer vectors in female, older adults, and those with CCI ≥ 3. CONCLUSION: Finding a relationship between BIVA and CCI suggests the first identified coherent differences, potentially correlated with diseases, representing a first contribution to support this type of assessment. Therefore, with BIVA, healthcare professionals may monitor abnormalities and adopt preventive nutrition care measures on patients post-AMI to improve their clinical status.

Phase angle as a prognostic indicator in critically ill children: A systematic review.

Phase angle (PhA) may reflect the integrity of cellular membranes, hydration status, and total body cell mass. Studies have shown that PhA can be used as a good predictor for evaluation of disease severity in critically ill adults. However, there is a lack of studies assessing the association between PhA and clinical outcomes in critically ill children. This systematic review described the association between PhA at pediatric intensive care unit (PICU) admission with clinical outcomes in critically ill children. The search was conducted using PubMed/Medline, Scopus, Web of Science, EMBASE and LILACS until July 22, 2022. Studies that evaluate the association between PhA at PICU admission in critically ill children and clinical outcomes were eligible. Data regarding population, study design, setting, bioelectrical impedance analysis (BIA) protocol used, PhA classification, and outcome analysis were extracted. Risk of bias was assessed by Newcastle-Ottawa Scale. Among the 4669 articles screened, five prospective studies were included. The studies have shown association between lower values of PhA at PICU admission with longer PICU and hospital length of stay, duration of mechanical ventilation, septic shock, and higher mortality risk. Small sample size, different clinical conditions, and methodological differences of the studies regarding BIA equipment and cutoffs of PhA were observed. Although the studies have limitations, the PhA has a potential role in predicting clinical outcomes in critically ill children. Larger studies with standardized PhA protocols and other relevant clinical outcomes are necessary.