Phase angle and impedance ratio as meta-inflammation biomarkers after a colon cleansing protocol in a group of overweight young women.

Objective. Blood C-reactive protein (CRP) and the electrical bioimpedance spectroscopy (EBIS) variables phase angle (PhA) and impedance ratio (IR) have been proposed as biomarkers of metainflammation in overweight/obesity. CRP involves taking blood samples, while PhA and IR imply a less-than-2-minute-non-invasive procedure. In this study, values for these variables and percent body fat mass (PBFM) were obtained and compared before and immediately after a colon cleansing protocol (CCP), aimed at modulating intestinal microbiota and reducing metainflammation, as dysbiosis and the latter are intrinsically related, as well as along a period of 8 weeks after it.Approach. 20 female volunteers (20.9-24.9 years old) participated: 12 in an overweight group (OG), and 8 in a lean group (LG). TheOGwas divided in two subgroups (n= 6, each): control (CSG) and experimental (ESG). TheESGunderwent a 6-day CCP at week 2, while 5 volunteers in theCSGunderwent it at week 9.Main results.Pre/post-CCP mean values for the variables in theOGwere: PBFM (34.3/31.3%), CRP (3.7/0.6 mg dl-1), PhA (6.9/7.5°) and IR*10 (0.78/0.77). CalculatedR2correlation factors among these variables are all above 0.89. The favourable changes first seen in theESGwere still present 8 weeks after the CCP.Significance.(a) the CCP drastically lowers meta-inflammation, (b) EBIS can be used to measure metainflammation, before and after treatment, (c) for microbiota modulation, CCP could be a good alternative to more drastic procedures like faecal microbiota transplantation; (d) reestablishing eubiosis by CCP could be an effective coadjutant in the treatment of overweight young adult women.

Standardized phase angle: relationship with functionality, muscle mass and postoperative outcomes in surgical cancer patients.

To evaluate the association of standardized phase angle (SPA) with nutritional status, functional parameters, and postoperative outcomes in surgical cancer patients. This prospective study includes 59 cancer patients from Pelotas (Brazil) admitted for elective cancer surgery. We obtained the phase angle through Bioelectrical Impedance Analysis (BIA) and standardized it according to the population's reference values. We estimated the muscle mass using BIA for later calculation of the Skeletal Muscle Index (SMI) and performed handgrip strength (HGS) and gait speed (GS) tests. We used the Patient-Generated Subjective Global Assessment (PG-SGA) to assess the nutritional status. Postoperative complications and duration of hospital stay were evaluated as the outcomes. The prevalence of malnutrition in the sample was 28.8%, according to ASG-PPP. SPA was statistically lower in patients with malnutrition, with lower HGS and reduced GS. For postoperative outcomes, patients with severe complications and those with prolonged hospitalization also had lower SPA values. The greater the number of functional alterations in patients, the lower the SPA value, mainly when associated with reduced muscle mass assessed by BIA, suggesting that muscle mass reduction plays an important role in the association between functional alterations and phase angle in patients with cancer. According to the parameters used in this study, low SPA value was associated with impaired nutritional and functional status and negative outcomes in the analyzed sample.

Electrical bioimpedance analysis and comparison in biological tissues through crystalloid solutions implementation.

Electrical bioimpedance is a non-invasive and radiation-free technique that was proposed to be used in different clinical areas, however, its practical use is limited due to its low capacity to discriminate between tissues. In order to overcome this limitation, our research group proposes to incorporate the contrast media into the electrical bioimpedance procedure. The main objective of the present study was to assess the crystalloid solutions as a possible contrast media to discriminate between different tissue types in the bioimpedance technique. Two medical-grade crystalloid solutions (Hartmann and NaCl 0.9%) were injected into three biological ex vivo models: kidney, liver, and brain. BIOPAC system was used to acquire bioimpedance data before and after the injections. The data was adjusted to the Debye electrical model. The analysis of measured values showed substantial bioimpedance disparities in tissues subjected to isotonic solutions. The NaCl solution exhibited more pronounced changes in electrical parameters compared to the Hartmann solution. Similarly, NaCl solution displayed superior discriminatory capabilities among tissues, with variations of 465%, 157%, and 206%. Distinct spectral modifications were identified, with tissues demonstrating unique responses at each frequency of analysis relative to untreated tissue. Variations in bandwidth alterations were discernible among tissues, providing clear distinctions. In conclusion, the research showed that the crystalloid solution exhibited greater sensitivity and superior tissue contrast at specific frequencies. This study's findings underscore the feasibility of implementing crystalloid solutions to enhance tissue discrimination, similar to the effects of contrast agents.

Role of the phase angle in the prognosis of the cirrhotic patient: 15 years of follow-up.

BACKGROUND: In 2019, cirrhosis accounted for 2.4% of global deaths. The projection for 2030 is an increase in this index. In recent years, hospitalization costs have escalated by 36% for compensated cirrhosis and 24% for decompensated cirrhosis. Therefore, it is necessary to identify a tool capable of predicting the mortality of these patients according to their clinical condition and consequently extending their survival time. Different studies have shown that the phase angle (PA) can be a feasible method in clinical practice, with the potential to guide assertive patient management in the therapeutic of chronic liver disease. AIM: To evaluate the prognostic role of PA in cirrhotic patients over a 15-year follow-up period. METHODS: Retrospective cohort study with 129 cirrhotic patients of both sexes over 18 years old. Diagnosis of cirrhosis by liver biopsy. The first year of data collection was 2007, and data regarding outcomes was collected in 2023. Data were gathered from medical records, such as esophageal varices (EV), EV bleeding, ascites, spontaneous bacterial peritonitis (SBP), encephalopathy, laboratory findings and PA. The cut-off value for the PA was 5.4°, a value described in 2012 by Fernandes et al for 129 patients evaluated in this study and the cut-off points for the Brazilian population presented in percentiles (P), as described by Mattiello et al. The mortality was assessed using the PA percentile through Kaplan-Meier curves and multivariate binary logistic regression models. RESULTS: Patients were divided into two groups according to the PA 5.4th (PA > 5.4°, n = 40; PA ≤ 5.4°, n = 89) PA percentile (< P50, n = 56; ≥ P50 n = 73). The percentile classification was more accurate in identifying long-term deaths than the 5.4º PA. Patients with < P50 had a higher number of relevant complications such as ascites, SBP, liver encephalopathy and HCC. PA is strongly correlated with serum albumin (P < 0.001), International Normalized Ratio (P = 0.01), total bilirubin (P = 0.02) and direct bilirubin (P = 0.003). PA is correlated with survival time (P < 0.001) and length of stay (P = 0.02). Logistic regression analysis shows that an increase of 1° in PA enlarges the cirrhotic patient's chance of survival by 17.7%. CONCLUSION: PA is a good predictor of morbidity and mortality for cirrhotic patients. The PA by percentile showed greater sensitivity in predicting mortality compared to the cut-off point of 5.4º.

Preclinical evaluation of the effects of soy lecithin on body composition / Evaluación preclínica de los efectos de la lecitina de soya sobre la composición corporal

Introduction: Soy lecithin has become one of the most widely used dietary supplements with potential to treat obesity. Objective: To determine the effect of soy lecithin on body composition. Material and Methods: An experimental preclinical pharmacology study was carried out in the Laboratory of Antibodies and Experimental Biomodels (Labex-cim) and the Basic Sciences Laboratory of the University of Medical Sciences of Santiago de Cuba in 2019. Soy lecithin was administered for 30 days, in doses considered as maximum and minimum to two experimental groups of Wistar rats, to be compared with the control group that received regular feeding. Bioelectric variables and indicators of fat mass were estimated by establishing differences between the experimental groups using the Kruskal-Wallis test of independent samples and considering the level of significance less than 5 %. Results: Total body water, fat-free mass, extracellular water, and total body fat changed significantly compared to the control and between groups; also, there were variations in fat weight in the main compartments, increasing in the group supplemented at the minimum dose and reducing in the group that received the maximum dose of the product. The phase angle showed reduction in both experimental groups. Conclusions: Soy lecithin, depending on the dose, modifies the body composition in rats, the phase angle being an appreciable parameter for nutritional evaluation.

Introducción: La lecitina de soya se ha convertido en un suplemento dietético de los más utilizados con potencialidades para tratar la obesidad. Objetivo: Determinar el efecto de la lecitina de soya sobre la composición corporal. Material y Métodos: Se realizó un estudio de farmacología preclínica experimental en el Laboratorio de Anticuerpos y Biomodelos Experimentales (Labex-cim) y el Laboratorio de Ciencias Básicas de la Universidad de Ciencias Médicas de Santiago de Cuba, en 2019. Se administró lecitina de soja por 30 días, en dosis consideradas como máximas y mínimas a dos grupos experimentales de ratas Wistar, para ser comparados con grupo control que recibió alimentación habitual. Se estimaron variables bioeléctricas e indicadores de masa grasa estableciendo diferencias entre los grupos experimentales mediante la Prueba de Kruskal-Wallis de muestras independientes y considerando el nivel de significación menor del 5 %. Resultados: El agua corporal total, la masa libre de grasa, el agua extracelular y la grasa corporal total se modificaron de manera significativa en comparación con el control y entre grupos, así como existieron variaciones en el peso de la grasa en los compartimentos principales, incrementándose en el grupo suplementado a dosis mínima y reduciendo en el grupo que recibió dosis máxima del producto. El ángulo de fase mostró reducción en ambos grupos experimentales. Conclusiones: La lecitina de soya, dependiendo de la dosis, modifica la composición corporal en ratas siendo el ángulo de fase un parámetro apreciable para la evaluación nutricional.

Parasitic Effects on Electrical Bioimpedance Systems: Critical Review.

Parasitic capacitance represents the main error source in measurement systems based on electrical impedance spectroscopy. The capacitive nature of electrodes' impedance in tetrapolar configuration can give origin to phase errors when electrodes are coupled to parasitic capacitances. Nevertheless, reactive charges in tissue excitation systems are susceptible to instability. Based on such a scenario, mitigating capacitive effects associated with the electrode is a requirement in order to reduce errors in the measurement system. A literature review about the main compensation techniques for parasitic capacitance was carried out. The selected studies were categorized into three groups: (i) compensation in electronic instrumentation; (ii) compensation in measurement processing, and (iii) compensation by negative impedance converters. The three analyzed methods emerged as effective against fixed capacitance. No method seemed capable of mitigating the effects of electrodes' capacitance, that changes in the frequency spectrum. The analysis has revealed the need for a method to compensate varying capacitances, since electrodes' impedance is unknown.

Multifrequency bioimpedance by spectroscopy vs. routine methods in the management of hydration status in peritoneal dialysis patients: A randomized control trial.

Background: Overhydration (OH) is common in peritoneal dialysis (PD) and increases the cardiovascular risk. Multifrequency bioimpedance spectroscopy (BIS) has been proposed to estimate the hydration in dialysis. Our objective was to evaluate if BIS is superior than control based on clinical assessment plus single-frequency bioimpedance (SF-BIA) on the fluid control and intermediate cardiovascular outcomes. Methods: Randomized controlled study in adult PD patients, with a 9-month follow-up, allocated into two groups: control and BIS. Data were collected from medical records. SF-BIA and BIS, laboratory exams, ambulatory blood pressure monitoring, echocardiography (ECHO), and pulse wave velocity (PWV) were evaluated. The BIS data were available to the medical team only in BIS group. Results: 34 patients completed the study, 17 in each group. At the endpoint the BIS group had a significant (p < 0.05) greater proportion of patients with OH/extracellular water (OH/ECW%) ≤ 15% than the control (94.1% vs. 52.9%), and a lower OH mean (2.1 ± 1.6 vs. 0.9 ± 1.1 L). The control group has a significant increase in the tumor necrosis factor alpha median concentration from baseline to six [11.9 (6.0-24.1) vs. 44.7 (9.4-70.6) pg/ml] and 9 months [11.9 (6.0-24.1) vs. 39.4 (27.9-62.6) pg/ml], and in the N-terminal fragment of pro-B-type natriuretic peptide median [239 (171.5-360.5) vs. 356 (219-1,555) pg/ml]. For cardiovascular parameters, BIS group presented a significant reduction in radial PWV [7.7 (6.9-9.2) vs. 6.5 (5.5-8.4) m/s] at 9 month, while in the control presented a significant increase in mean central systolic blood pressure (BP) (106.8 ± 11.2 vs. 117.6 ± 16.5 mmHg) and in central diastolic BP (90.4 ± 9.8 vs. 103.3 ± 12.5 mmHg) at 9 months. The left ventricular mass (LVM)/body surface presented a significant reduction in the control (109.6 ± 30.8 vs. 101.2 ± 28.9 g/m2) and BIS group (107.7 ± 24.9 vs. 96.1 ± 27.0 g/m2) at 9 months. Conclusion: The results suggest BIS is superior than the clinical evaluation plus SF-BIA for the fluid control of PD patients. Clinical trial registration: [https://www.ClinicalTrials.gov], identifier [RBR-10k8j3bx].

A low-cost, portable, two-dimensional bioimpedance distribution estimation system based on the AD5933 impedance converter.

This study proposes a low-cost, portable, eight-channel electrical impedance tomograph based on the AD5933 impedance converter. The patterns for current injection and voltage measurement are managed by an Arduino Mega 2560 board and four 74HC4067 Texas Instruments multiplexers. Regarding the experimental results, the errors in the impedance estimates of an electrical circuit that represents a Cole model were less than 1.14% for the magnitude and 4.15% for the phase. Furthermore, the signal-to-noise ratio measured in a resistive phantom was 55.23 dB. Additional experiments consisted of placing five spheres of different size and conductivity in a saline tank, measuring their impedance through eight electrodes, and then generating impedance maps using the Electrical Impedance Tomography and Diffuse Optical Tomography Reconstruction Software (EIDORS). These maps were different for each sphere, suggesting the proposed prototype as a promising alternative for medical applications.

Electrical Impedance to Easily Discover Undeclared Freeze-thaw Cycles in Slaughtered Bovine Meat.

A portable electrical impedance spectroscopy device was developed to monitor the bioimpedance resistive component of bovine meat by injecting a sinusoidal current of 1 mA at 65 kHz. Both right and left longissimus dorsi muscles were trimmed from 4 slaughtered cows. The left muscle portions were frozen to -18 °C for 7 days while the right ones were meantime maintained at 5 °C. Mean value of impedance per length (Ω/cm) of frozen and thawed left samples was 31% lower than that of right non-frozen one (P = 0.0001). It was concluded that the device is reliable for monitoring the maturation of beef meat in situ with the possibility of revealing undeclared freeze-thaw cycles.

Agreement of Single-Frequency Electrical Bioimpedance in the Evaluation of Fat Free Mass and Fat Mass in Peritoneal Dialysis Patients.

Background: Protein-energy wasting is related to impairment of quality of life and lower survival of end-stage kidney disease (ESKD) patients. The evaluation of body composition, especially fat free mass (FFM) and fat mass (FM), is important for the prediction of outcomes in these individuals. The aim of this study was to compare the FFM and FM measurements obtained by single-frequency bioimpedance (SF-BIA) and by a multiple frequency bioimpedance (MF-BIA) device, using dual energy X-ray absorptiometry (DXA) peritoneal dialysis (PD) patients. Methods: This was a cross-sectional study involving adult patients undergoing regular PD, in which we performed SF-BIA, MF-BIA, and DXA at the same visit. To compare the bioimpedance values with DXA, we used: Person correlation (r), intraclass correlation coefficient (ICC), and Bland-Altman concordance analysis. Results: The sample consisted of 50 patients in the PD, with mean age of 55.1 ± 16.3 years. Both bioimpedance methods showed a strong correlation (r > 0.7) and excellent reproducibility (ICC > 0.75) compared to DXA. According to the Bland-Altman diagram, SF-BIA showed agreement in body compartment measurements, with no proportionality bias (p > 0.05), without systematic bias for FFM (-0.5 ± 4.9, 95% CI -1.8 to 0.9, p = 0.506), and for FM (0.3 ± 4.6, p = 0.543). MF-BIA did not present a proportionality bias for the FFM, but it underestimated this body compartment by 2.5 ± 5.4 kg (p = 0.002). In addition, MF-BIA presented proportionality bias for FM. Conclusion: SF-BIA was a more accurate assessing method than MBIA for FFM and FM measurements in PD patients. Because it is a low-cost, non-evaluator-dependent measurement and has less systematic bias, it can also be recommended for fat mass and free-fat mass evaluation in PD patients.

Composición corporal y factores de riesgo metabólico en profesores de enseñanza básica de colegios de Chile / Body composition and metabolic risk factors in primary in primary school teachers in Chile

En el mundo la obesidad es considerada una pandemia que provoca grandes cambios metabólicos, responsables de las llamadas enfermedades crónicas no transmisibles (ECNT), las cuales presentan un 60 % de mortalidad, según la Organización Mundial de la Salud (2016). En Chile el 75 % de la población adulta y el 50,9 % de la población estudiantil, muestran índices de masa corporal de sobrepeso y obesidad, con un nivel de sedentarismo general de 66,2 %. Los objetivos de este trabajo fueron determinar los perfiles antropométricos, riesgo metabólico y niveles de actividad física en profesores de enseñanza básica en un colegio particular subvencionado de Arica-Chile. El total de los profesores, 12 varones y 29 mujeres, fueron evaluados según: peso, talla, perímetro de cintura, índice cintura-talla (ICT), índice de masa corporal (IMC), masa grasa (MG), masa grasa visceral (MGV) y masa muscular (MM). A todos ellos se les calculó el riesgo metabólico según protocolos de Ashwell & Gibson (2016) y el IMC según fórmula de Quetelet. Para determinar los porcentajes de MG, MM y MGV, se utilizó instrumento de bioimpedancia eléctrica, Omron HBF-514C. Posteriormente se les aplicó una encuesta sobre nivel de actividad física (IPAQ). Los datos fueron analizados en estadístico IBM SPSS para tendencia central, dispersión, conteos y porcentajes. Para correlación se usó test de Pearson (r>0,5). Los resultados muestran que un 68,3 % de los profesores presenta sobrepeso y obesidad. El IMC y porcentaje de MGV son significativamente más alto en varones que en mujeres (30,6 ±7,0 / 26,9±4,6 y 11,2±5,6 / 7,6±2,5 respectivamente). El riesgo metabólico general de la población en estudio fue de 58,5 % (75 % y 51,7 % varones y mujeres respectivamente). Se observa una alta correlación entre IMC-MGV (0,84), IMC-ICT (0,84) y MM-MG (0,85). Respecto al nivel de actividad física, solo el 19,5 % de los profesores muestra un nivel de actividad física alto. Se concluye que los profesores presentan valores antropométricos alterados que indican altos índices de riesgos metabólicos y con bajos niveles de actividad física. Independientemente, las mujeres presentan mejores índices morfométricos en todos los parámetros en estudio respecto a los profesores varones. Existe una alta correlación (r) entre el índice de masa corporal y los porcentajes de masa de grasa visceral y el índice de de cintura talla. Se sugiere enfocar las intervenciones educativas según sello de vida saludable, incentivando la actividad física y mejorar los hábitos alimenticios en los profesores.

Obesity is considered a global pandemic that causes major metabolic changes. It is responsible for the so-called noncommunicable chronic diseases (NCDs), which report a 60 % mortality rate (WHO, 2017). In Chile, 63 % of the population shows body mass indexes (BMI) of overweight and obesity, with a sedentary level of 86.7 %. The objectives of this work were to determine the anthropometric profiles, metabolic risk, and physical activity levels in primary school teachers, in a subsidized school in Arica, Chile. The teachers (n=41), 12 men, and 29 women were evaluated according to weight, height, waist circumference (WC), waist-to-height index (WHI), BMI, Fat Mass (FM), Visceral Fat Mass (VFM) and Muscle Mass (MM). All of them were calculated for metabolic risk, according to Ashwell & Gibson protocols and BMI according to Quetelet's formula. To determine the percentages of FM, MM, and VFM, an electric bioimpedance instrument, Omron HBF-514C, was used. Subsequently, a survey of physical activity level (IPAQ) was applied. The data were analyzed in the IBM SPSS statistic for central tendency, dispersion, counts, and percentages. For correlation, Pearson's test (r> 0.5) was used. The results show that 68.3 % of teachers are overweight and obese. BMI and percentage of VFM are significantly higher in men than in women (30.6 ± 7.0 / 26.9 ± 4.6 and 11.2 ± 5.6 / 7.6 ± 2.5 respectively). The overall metabolic risk of the study population was 58.5 % (75 % and 51.7 % men and women, respectively). There is a high correlation between BMIVFM (0.84), BMI-WHI (0.84), MM-FM (0.85). Regarding the level of physical activity, only 19.5 % of teachers show a high level of physical activity. It is concluded that teachers have altered anthropometric values that indicate high rates of metabolic risks and low levels of physical activity. Regardless, women have better morphometric indexes in all parameters under study, compared to male teachers. There is a high correlation (r) between body mass index and percentages of visceral fat mass and waist height index. It is suggested to focus on educational interventions according to the healthy life seal, promoting physical activity, and improving eating habits in teachers.

Bioelectrical impedance vector analysis evaluates cellularity and hydration in cirrhotic patients.

BACKGROUND: Malnutrition in cirrhotic patients is correlated with mortality and a better response to liver transplantation. However, recovery of the nutritional status in these patients is a challenge due to the difficulty in establishing a reliable nutritional diagnosis. The bioelectrical impedance vector analysis (BIVA) method appears as a feasible tool in clinical practice to define the physiological state of cirrhotic patients by assessing hydration and body cellularity. AIM: To evaluate body composition in cirrhotic patients using BIVA. METHODS: This retrospective cross-sectional study was carried out by following cirrhotic outpatients at a hospital in Porto Alegre, Brazil. A tetrapolar bioelectrical impedance analysis device was used to evaluate cellularity and hydration and to perform the BIVA. The BIVA graphic was elaborated by software and for statistical analysis a significance level of 5% (P ≤ 0.05) was considered. RESULTS: One hundred and ninety patients, 61.1% males, with a mean age of 56.6 ± 11.0 years, were evaluated. Of these, 56.3% had Child-Turcotte-Pugh (CTP) A score, and the prevalent etiology was hepatitis C virus (47.4%). The patients were classified according to cellularity and hydration by the quadrants and ellipses of the BIVA method, quadrant 1 (47.9%); quadrant 2 (18.9%); quadrant 3 (14.2%); and quadrant 4 (18.9%). Those classified in quadrant 1 and 2 had a higher phase angle compared to those in quadrants 3 and 4 (P < 0.001). Quadrant 2 patients had a lower average age than the other groups. The association with CTP score showed that patients in quadrant 2 had a higher proportion of CTP A, and those in quadrant 4 had a higher proportion of CTP C (P < 0.052). CONCLUSION: The BIVA method allows identification of the cellularity and hydration status of cirrhotic patients, and its association with clinical factors determines the disease severity, age and prognostic index.

Relationship between body composition and level of physical activity among university students / Relación entre la composición corporal y nivel de actividad física en estudiantes universitarios

Introduction: the body composition and lifestyle of university students are influenced by behavioral, psychological, socioeconomic and cultural factors. Objective: to analyze body composition and its correlation with lifestyle in a sample of university students in the health area living at the Ribeirao Preto Campus of the University of São Paulo (USP). Methodology: a cross-sectional study was conducted on 501 students enrolled in USP courses of the Ribeirao Preto Campus. Weight and height were measured and body composition was determined by bioelectrical impedance. The short version of the International Physical Activity Questionnaire (IPAQ) was then applied. Results: The sample predominantly consisted of females (73.05%), with 26.95% males. The averages of age, weight, stature body mass index (BMI), total fat mass and fat-free mass were 20.4 ± 2.8 years, 63.0 ± 13.5 kg, 166.9 ± 9.0 cm, 22.4 ± 3.4 kg/m², 24.0 ± 7.5%, 45.3 ± 10.3 kg, respectively. Although almost 70% of the students were in the normal BMI range, 70.8% of them had high levels of fat mass. According to IPAQ, the individuals were classified as sedentary (10.2%), irregularly active (39.3%), active (42.1%), and very active (8.4%). Conclusions: Most of the university students studied were classified as being of normal weight according to the BMI, but the high levels of body fat mass detected should not be overlooked. In addition, even though most of the sample was considered to be active, according to the IPAQ, it can be seen that practically half the students (49.5%) were irregularly active or sedentary.

Introducción: la composición corporal y el estilo de vida de los estudiantes universitarios se ven influidos por factores conductuales, psicológicos, socioeconómicos y culturales. Objetivo: analizar la composición corporal y su correlación con el estilo de vida en una muestra de estudiantes universitarios del área de la salud que viven en el campus de Ribeirao Preto de la Universidad de São Paulo (USP). Metodología: estudio transversal que se llevó a cabo en 501 estudiantes matriculados en los cursos del Campus USP Ribeirão Preto. El peso y la talla se midieron y la composición corporal se determinó mediante impedancia bioeléctrica. A continuación, se aplicó la versión corta de la International Physical Activity Questionnaire (IPAQ). Resultados: La muestra consistió predominantemente de mujeres (73,05 %), con 26,95 % de hombres. Los promedios de edad, peso, índice de masa corporal (IMC), la masa grasa total y la masa libre de grasa fueron 20,4 ± 2,8 años, 63,0 ± 13,5 kg, 166,9 ± 9,0 cm, 22,4 ± 3,4 kg/m², 24,0 ± 7,5%, 45,3 ± 10,3 kg, respectivamente. Aunque cerca del 70% de los estudiantes estaban en el rango normal de IMC, 70,8% tenían altos niveles de masa grasa. Según IPAQ, los individuos fueron clasificados como sedentarios (10,2%), irregularmente activos (39,3%), activos (42,1%), y muy activos (8,4%). Conclusiones: La mayoría de los estudiantes universitarios estudiados fueron clasificados como de peso normal de acuerdo con el índice de masa corporal, pero los altos niveles de masa grasa corporal detectada no deben pasarse por alto. Además, a pesar de que la mayor parte de la muestra se considera activo, de acuerdo con la IPAQ, se puede ver que prácticamente la mitad de los estudiantes (49,5%) eran de forma irregular activos o sedentarios.

Parámetros bioeléctricos in vitro e in vivo, estimados con los analizadores Bodystat®1500-MDD y BioScan®98 / Bioelectrical parameters in vitro and in vivo estimated with analyzers Bodystat®1500-MDD and BioScan®98

Se efectuó un estudio comparativo de 2 analizadores comerciales de bioimpedancia eléctrica corporal (Bodystat® 1500-MDD y BioScan®98) en el Servicio de Oncopediatría del Hospital Infantil Sur de Santiago de Cuba, desde septiembre hasta octubre del 2009, para lo cual se realizó una simulación in vitro con los calibradores de cada equipo y un estudio in vivo de 32 adultos aparentemente sanos y 32 niños con diferentes afecciones. La resistencia eléctrica y la reactancia capacitiva se estimaron con ambos analizadores; además, se calcularon el módulo de impedancia y el ángulo de fase. La prueba t-student de 2 medias para muestras apareadas y el método de Bland-Altman fueron los criterios estadísticos usados. No existieron diferencias significativas entre ambos analizadores al introducir los factores de corrección para la resistencia eléctrica y la reactancia capacitiva; por tanto, es posible usarlos indistintamente para caracterizar bioeléctricamente a los individuos aparentemente sanos y pacientes con diferentes enfermedades.

A controlled trial with 2 body electrical impedance commercial analyzers was carried out (Bodystat® 1500-MDD and BioScan®98) at the Pediatric Oncology Department of the Southern Children Hospital in Santiago de Cuba, from September to October 2009, for which an in vitro simulation with gauges of each device and an in vivo study in 32 apparently healthy adults and 32 children with different conditions were conducted. Electrical resistance and capacitive reactance were estimated with both analyzers, and impedance module and phase angle were also calculated. The two-means Student's t test for paired samples and the Bland-Altman method were used as statistical criteria. There were not significant differences between the two analyzers by introducing correction factors for electrical resistance and capacitive reactance; therefore, it is possible to use either to characterize bioelectrically apparently healthy individuals and patients with different conditions.

Associação entre ângulo de fase, PRISM I e gravidade da sepse / Association between phase angle, PRISM I and sepsis severity

JUSTIFICATIVA E OBJETIVOS: Ângulo de fase (AF) é a diferença entre a voltagem e a corrente e pode ser usado como indicador de massa celular corporal. Estudos clínicos mostram que baixos AF estão associados com morbidade e mortalidade em pacientes críticos. O objetivo deste estudo foi conhecer a relação entre AF e o escore pediátrico de risco de mortalidade (PRISM I) em pacientes pediátricos sépticos críticos, associando esse indicador c om a gravidade da sepse. MÉTODO: Estudo transversal realizado na Unidade de Terapia Intensiva (UTI) Pediátrica do Instituto Fernandes Figueira. Os pacientes foram caracterizados de acordo com faixa etária, sexo, gravidade da sepse, etiologia da insuficiência respiratória, escore de PRISM I, grau de disfunção de múltiplos órgãos e sistemas (DMOS). A análise de bioimpedância elétrica (BIA) foi realizada em todos os pacientes e, através da razão dos valores de reactância (Xc) e resistência (R), foi calculado o AF (AF = arco-tangente da reactância/resistência x 180º /Pi). RESULTADOS: Foram avaliados 75 pacientes, sendo 68 (90,7 por cento) com sepse. A incidência de choque séptico foi 39,7 por cento, sepse grave 42,6 por cento e sepse 17,6 por cento. Não houve diferença estatística significativa entre as médias de ângulo de fase e as categorias de PRISM I, porém observou-se uma relação inversa entre os valores de AF e as categorias de PRISM I, DMOS e tempo de internação. Os valores mais baixos de AF (1,5º-2,2º) foram observados no maior escore de PRISM I (> 30 por cento). CONCLUSÕES: Os pacientes pediátricos críticos apresentaram baixos valores de angulo de fase, portanto deve ter a sua importância prognóstica estudada.

BACKGROUND AND OBJECTIVES: Phase angle (PA) is the difference between voltage and current and can be used as an indicator of body cell mass. Clinical studies show that low phase angle is associated with morbidity and mortality of critical patients. The purpose of this study was to know the relation between phase angle and the Pediatric Risk of Mortality I (PRISM I) score, associating this score with the severity of sepsis. METHODS: A transversal study was performed at the Pediatric Intensive Care Unit (PICU) in Instituto Fernandes Figueira. The patients were classified according to age, gender, sepsis severity, cause of respiratory failure, PRISM I score, multiple organ dysfunction syndromes (MODS). Electrical bioimpedance analysis (BIA) was performed in all patients. Phase angle was calculated directly from reactance (Xc) and resistance (R). AF = arc-tangent reactance/resistance x 180º/Pi. RESULTS: 75 patients (68 septic) were evaluated. The incidence of septic shock was 39.7 percent, severe sepsis 42.6 percent and sepsis 17.6 percent. There was no significative statistical difference between the mean values of BIA and the categories of PRISM I, MODS, or the length of stay the PICU. The PA's lowest values (1.5º-2.2º) were associated to the greatest PRISM's scores (> 30 percent). CONCLUSIONS: Pediatric critical patients show low phase angle values, which might have prognostic implication.