Validity of bioelectrical impedance analysis to estimate fat-free mass changes in the brazilian army cadets

Orientadores: Ezequiel Moreira Gonçalves, Gil Guerra JúniorDissertação (mestrado) - Universidade Estadual de Campinas, Faculdade de Ciências MédicasResumo: O objetivo principal deste estudo foi analisar a validade de uma equação preditiva específica baseada na análise de impedância bioelétrica (BIA), desenvolvida a partir de uma amostra de cadetes do exército Brasileiro, na avaliação das alterações da massa isenta de gordura (MIG), após um período de cerca de sete meses de rotina militar, utilizando os valores determinados pela absorciometria por dupla emissão de raio x (DXA) como o método de referência. Inicialmente, foi analisado a validade de equações preditivas de BIA já publicadas e da equação específica desenvolvida no presente estudo, na estimativa da MIG. Métodos: Foram avaliados 396 e 310 (estudo transversal e longitudinal, respectivamente) cadetes do exército Brasileiro do sexo masculino com idade entre 17 e 24 anos. Oito equações preditivas de BIA e uma específica, foram utilizadas para testar a validade nesta amostra. O teste t de Student, o coeficiente de determinação (R²), o erro padrão de estimativa (EPE), o teste de Lin e de Bland-Altman, foram utilizados para determinar a validade das equações preditivas de BIA na estimativa da MIG. Resultados: No estudo transversal, as oito equações preditivas de BIA apresentaram diferenças significativas na MIG (-3,0 a 2,4 kg) comparadas com a DXA (p<0,05); o valor de R² variou de 0,68 a 0,88 e o EPE variou de 2,3 a 3,6 kg. A MIG da equação específica não apresentou diferença significativa com a DXA tanto no momento pré, quanto no momento pós (p<0,001). O valor de R² no momento pré e pós foi de 0,87 e 0,91, respectivamente; o EPE foi de 2,3 e 2,0 kg, respectivamente, e o limite de concordância diminuiu de 9,1 para 7,7 kg. Conclusão: As oito equações preditivas de BIA testadas não demonstraram serem válidas para esta amostra. A equação específica de BIA desenvolvida neste estudo, demonstrou melhores resultados na avaliação transversal e apresentou boa acurácia nessa amostra de cadetes do exército na avaliação das alterações da MIG. Contudo, seus resultados devem ser analisados com cautela quando a equação for aplicada em indivíduos com diferentes valores de MIGAbstract: The aim of this study was to analyze a specific prediction equation based on bioelectrical impedance analysis (BIA) developed in a sample of Brazilian Army cadets, by evaluating fat-free mass (FFM) changes after seven months of military command, and using values determined by dual-energy X-ray absorptiometry (DXA) as a reference method. Initially, the validity of published predictive BIA equations was analyzed and a specific equation was developed in the present study to estimate FFM. Methods: A total of 396 and 310 males (cross-sectional and longitudinal study, respectively) Brazilian Army cadets, aged between 17 and 24 years were included. The study used eight predictive BIA equations and a specific equation to validate this sample. Student's t-test, adjusted coefficient of determination (R²), standard error of estimation (SEE), Lin's approach and Bland-Altman test were used to determine the BIA equations¿ validity of prediction for estimating FFM. Results: In the cross-sectional study, eight predictive BIA Equations showed significant differences in FFM (-3.0 to 2.4 kg) compared with DXA (p<0.05); R² values ranged from 0.68 to 0.88, and SEE ranged from 2.3 to 3.6 kg. During pre and post moments, FFM estimated by the specific BIA equation showed no significant difference with DXA (p<0.001). The pre and post R² values were 0.87 and 0.91, respectively; SEE was 2.3 and 2.0 kg, respectively, and the limits of agreement decreased from 9.1 to 7.7 kg. Conclusion: The eight predictive BIA Equations tested were not valid for this sample. The specific BIA equation developed in this study showed better results in the cross-sectional study and showed better accuracy on FFM changes in this sample of Brazilian Army cadets. However, its results should be analyzed with caution, especially if it is used on samples of individuals with different FFM valuesMestradoSaude da Criança e do AdolescenteMestra em Ciências2014/34920-12012/16778-8, 2016/03980-4CAPESFAPES

Accuracy of body mass index cutoffs for classifying obesity in chilean children and adolescents

To determine the accuracy of two international Body Mass Index (BMI) cut-offs for classifying obesity compared to the percentage of fat mass (%FM) assessed by Dual-Energy X-ray Absorptiometry (DXA) in a Chilean sample of children and adolescents. The subjects studied included 280 children and adolescents (125 girls and 155 boys) aged 8 to 17 years. Weight and height were measured. The BMI was calculated. Two international references (IOFT and WHO) were used as cut-off points. The %FM was assessed by DXA. The receiver operating characteristic (ROC) curve was used to assess the performance of BMI in detecting obesity on the basis of %FM. A high correlation was observed between the %FM measured by the DXA and the Z-scores of IOTF and WHO scores in the Chilean adolescents separated by sex (r = 0.78–0.80). Differences occurred in both references (IOFT and WHO) in relation to the criteria (p < 0.001). Both references demonstrated a good ability to predict sensitivity (between 84% and 93%) and specificity (between 83% and 88%) in both sexes of children and adolescents. A high correlation was observed between the Z-score of the BMI with the percentage of fat determined by the DXA. Despite this, the classifications using the different BMI cut-off points showed discrepancies. This suggests that the cut-off points selected to predict obesity in this sample should be viewed with caution135Children, adolescents and nutrition12th International symposium on recent advances in environmental health researchWe would like to express our thanks to all the participating students, teachers, and schools for their tremendous support. Supported by the Regular Fondecyt Project 1141295. Conicyt, Chile. We thank the Asociación Iberoamericana de Postgrado (AUIP) for the aid granted through the Academic Mobility Progra

Fat mass predicts food-specific inhibitory control in children

Impaired inhibitory control has been associated with obesity, high blood pressure and lack of physical fitness. These impairments are thought to be related to decreased cognitive control over excessive food consumption and may start in childhood. However, previous studies in children have examined inhibitory control deficits using general (non-food-specific) tasks and relied on body mass index, which does not distinguish the amount of fat mass. As fat mass, hypertension and physical fitness have been shown to play a role in cognition, the aim of this study was to investigate the relationship between these variables and food specific inhibitory control in children. Subjects/methods: Children's (n = 48; Age 10.7 +/- 0.6 years) general characteristics, fat mass, cardiorespiratory fitness, blood pressure and performance on a food-specific inhibitory control task (Go/No-go) were measured across two sessions. Results: Fat mass and sex were associated with inhibitory control performance, while no associations were found for cardiorespiratory fitness, blood pressure and other potential confounding variables (i.e. age, pubertal timing, body mass index, waist-to-hip ratio, scholar test performance and heart rate). Linear regression analyses showed that only fat mass predicted poorer food-specific inhibitory control (beta = 0.36; Delta R-2 = 0.04; p < .05) and sex predicted inhibitory control for toys (control condition) (beta = 0.42; Delta R-2 = 0.11; p < .01). Neither blood pressure nor cardiorespiratory fitness predicted food specific inhibitory control. Conclusion: These findings suggest that fat mass is an independent predictor of inhibitory control for food in children204155161COORDENAÇÃO DE APERFEIÇOAMENTO DE PESSOAL DE NÍVEL SUPERIOR - CAPESsem informaçã

Mortality from gastrointestinal congenital anomalies at 264 hospitals in 74 low-income, middle-income, and high-income countries: a multicentre, international, prospective cohort study

Summary Background Congenital anomalies are the fifth leading cause of mortality in children younger than 5 years globally. Many gastrointestinal congenital anomalies are fatal without timely access to neonatal surgical care, but few studies have been done on these conditions in low-income and middle-income countries (LMICs). We compared outcomes of the seven most common gastrointestinal congenital anomalies in low-income, middle-income, and high-income countries globally, and identified factors associated with mortality. Methods We did a multicentre, international prospective cohort study of patients younger than 16 years, presenting to hospital for the first time with oesophageal atresia, congenital diaphragmatic hernia, intestinal atresia, gastroschisis, exomphalos, anorectal malformation, and Hirschsprung’s disease. Recruitment was of consecutive patients for a minimum of 1 month between October, 2018, and April, 2019. We collected data on patient demographics, clinical status, interventions, and outcomes using the REDCap platform. Patients were followed up for 30 days after primary intervention, or 30 days after admission if they did not receive an intervention. The primary outcome was all-cause, in-hospital mortality for all conditions combined and each condition individually, stratified by country income status. We did a complete case analysis. Findings We included 3849 patients with 3975 study conditions (560 with oesophageal atresia, 448 with congenital diaphragmatic hernia, 681 with intestinal atresia, 453 with gastroschisis, 325 with exomphalos, 991 with anorectal malformation, and 517 with Hirschsprung’s disease) from 264 hospitals (89 in high-income countries, 166 in middleincome countries, and nine in low-income countries) in 74 countries. Of the 3849 patients, 2231 (58·0%) were male. Median gestational age at birth was 38 weeks (IQR 36–39) and median bodyweight at presentation was 2·8 kg (2·3–3·3). Mortality among all patients was 37 (39·8%) of 93 in low-income countries, 583 (20·4%) of 2860 in middle-income countries, and 50 (5·6%) of 896 in high-income countries (p<0·0001 between all country income groups). Gastroschisis had the greatest difference in mortality between country income strata (nine [90·0%] of ten in lowincome countries, 97 [31·9%] of 304 in middle-income countries, and two [1·4%] of 139 in high-income countries; p≤0·0001 between all country income groups). Factors significantly associated with higher mortality for all patients combined included country income status (low-income vs high-income countries, risk ratio 2·78 [95% CI 1·88–4·11], p<0·0001; middle-income vs high-income countries, 2·11 [1·59–2·79], p<0·0001), sepsis at presentation (1·20 [1·04–1·40], p=0·016), higher American Society of Anesthesiologists (ASA) score at primary intervention (ASA 4–5 vs ASA 1–2, 1·82 [1·40–2·35], p<0·0001; ASA 3 vs ASA 1–2, 1·58, [1·30–1·92], p<0·0001]), surgical safety checklist not used (1·39 [1·02–1·90], p=0·035), and ventilation or parenteral nutrition unavailable when needed (ventilation 1·96, [1·41–2·71], p=0·0001; parenteral nutrition 1·35, [1·05–1·74], p=0·018). Administration of parenteral nutrition (0·61, [0·47–0·79], p=0·0002) and use of a peripherally inserted central catheter (0·65 [0·50–0·86], p=0·0024) or percutaneous central line (0·69 [0·48–1·00], p=0·049) were associated with lower mortality. Interpretation Unacceptable differences in mortality exist for gastrointestinal congenital anomalies between lowincome, middle-income, and high-income countries. Improving access to quality neonatal surgical care in LMICs will be vital to achieve Sustainable Development Goal 3.2 of ending preventable deaths in neonates and children younger than 5 years by 2030

Efetividade de programas de intervenção escolar para reduzir fatores de risco à saúde em adolescentes: uma revisão sistemática

DOI: http://dx.doi.org/10.5007/1980-0037.2015v17n4p485   O objetivo do estudo foi realizar uma revisão sistemática sobre os programas de intervenção, com ações de atividades físicas e/ou educação nutricional, na redução de fatores de risco à saúde (sobrepeso/obesidade e alterações no perfil metabólico), em adolescentes escolares brasileiros. Foi realizada busca nas bases de dados eletrônicas Medline (PubMed), Lilacs, Embase, Scielo e Banco de Teses da Capes. Identificaram-se 1.568 estudos e 21 textos completos foram analisados, dos quais, cinco foram incluídos na revisão. A maioria dos estudos envolveu a prática de atividades físicas combinada à educação nutricional em diferentes regiões do país e todas as intervenções mostraram efeitos positivos na redução de fatores de risco à saúde. Conclui-se que todos os estudos nesta revisão demonstraram alterações positivas após as intervenções, mesmo que não significativas estatisticamente, reforçando a importância de programas de intervenção para a promoção de uma vida mais saudável e para reduzir os fatores de risco à saúde, em adolescentes

Determinant factors of cellular health among adolescent girls and boys

Several studies have demonstrated that cardiorespiratory fitness (CRF) and body adiposity are strong indicators of health during childhood and adolescence. However, it is not known if these parameters are associated with cellular health. For example, phase angle (PhA) is used to evaluate nutritional status and is an indicator of cellular health. In this study, we test if body composition and CRF have an influence on cellular health among adolescents of both genders. 203 girls (12.7 ± 1.3 years) and 221 boys (12.8 ± 1.3 years) were evaluated. The peak of height velocity (PHV) was used as an indicator of somatic maturation. The percentage of fat mass (%FM) was calculated based on skinfold thickness (triceps and calf). CRF was assessed with the Leger test. Bioelectrical impedance analysis provided parameters to calculate the values of PhA and fat-free mass (FFM). Bivariate correlation was used to verify the association between PHV with PhA, %FM, FFM and CRF. We used partial correlation to evaluate if PHV was a mediator of the relationship between PhA, %FM and CRF. A linear regression analysis adjusted by PHV was used to verify if variables (%FM, FFM and CRF) influenced cellular health among adolescents of both genders. The PHV showed a significant positive correlation with FFM in girls (r = 0.83, p<0.001) and boys (r = 0.83, p<0.001); with PhA in girls (r = 0.24, p<0.01) and boys (r = 0.38, p<0.001); and with %FM but only in girls (r = 0.15, p<0.05). PHV was negatively correlated with CRF in girls (r = -0.54, p<0.001) and boys (r = -0.20, p<0.01). Linear regression of the PhA adjusted by the PHV had an effect on %FM in girls (β = 0.233, p<0.05) but not in boys (β = 0.013, p=0.834), on CRF in boys (β = 0.166, p<0.05) but not in girls (β = 0.007, p=0.931), and on FFM in girls (β = 0.697, p<0.001) and in boys (β = 0.614, p<0.001). We discovered that PhA when controlled by somatic maturation seems to be more influenced by %FM in girls, CRF in boys, and FFM in both genders of adolescents. Interestingly, cellular health and CRF (for girls) and %FM (for boys) were not associated with PhA. This has implications for physical activity behavioral for improved health in adolescents of both genders51818818Annual Meeting of the American-College-of-Sports-Medicine (ACSM

Higher Body Fat but Similar Phase Angle Values in Patients with the Classical Form of Congenital Adrenal Hyperplasia in Comparison to a Control Group

This study aimed to compare phase angle (PhA) and bioelectrical impedance vector analysis (BIVA) values between adult patients with congenital adrenal hyperplasia caused by 21-hydroxylase deficiency (CAH21OHD) and a control group. A total of 22 patients (15 women, 22.9 ± 3.7 years) were compared with 17 controls (11 women, 27.0 ± 2.5 years). Body composition was determined by dual-energy X-ray absorptiometry. Bioelectrical impedance was used to calculate PhA, and BIVA was performed using specific software. Student’s t-test and analysis of covariance were used to compare groups. Hedges’ G and partial n2 were calculated for the effect estimates. Hotelling’s t2 test was used to compare the mean impedance vectors between the groups. The Mahalanobis test was used to determine the distance between confidence ellipses. Patients with CAH21OHD had a higher fat mass percentage than that of the control group (both sexes). There was no significant difference in PhA values between groups (CAH21OHD vs. control) in females (6.9° vs. 6.3°, p = 0.092) and males (8.2° vs. 8.1°, p = 0.849), after adjusting for covariates (age and height). BIVA analysis showed a significant difference in the mean impedance vectors between the female groups (T2 = 15.9, D = 1.58, p = 0.003) owing to the higher reactance/height (Δ = 8.5; p < 0.001) of the patients. The PhA did not significantly differ between the groups. Female patients had significantly higher reactance values. However, further studies are needed to determine the usefulness of bioimpedance parameters in evaluating the hydration status and cellular integrity of patients with CAH21OHD

Effect of Physical Training on Body Composition in Brazilian Military

The military are selected on the basis of physical standards and are regularly involved in strong physical activities, also related to particular sports training. The aims of the study were to analyze the effect of a 7-month military training program on body composition variables and the suitability of specific &lsquo;bioelectrical impedance vector analysis&rsquo; (spBIVA), compared to DXA, to detect the changes in body composition. A sample of 270 male Brazilian cadets (19.1 &plusmn; 1.1 years), composed of a group practicing military physical training routine only (MT = 155) and a group involved in a specific sport training (SMT = 115), were measured by body composition assessments (evaluated by means of DXA and spBIVA) at the beginning and the end of the military routine year. The effect of training on body composition was similar in SMT and MT groups, with an increase in LST. DXA and spBIVA were correlated, with specific resistance (Rsp) and reactance (Xcsp) positively related to fat mass (FM), FM%, LST, and lean soft tissue index (LSTI), and phase angle positively related to LST and LSTI. Body composition variations due to physical training were recognized by spBIVA: the increase in muscle mass was indicated by the phase angle and Xcsp increase, and the stability of FM% was consistent with the unchanged values of Rsp. Military training produced an increase in muscle mass, but no change in FM%, independently of the sample characteristics at baseline and the practice of additional sports. SpBIVA is a suitable technique for the assessment of body composition in military people

Accuracy of Body Mass Index Cutoffs for Classifying Obesity in Chilean Children and Adolescents

Objective: To determine the accuracy of two international Body Mass Index (BMI) cut-offs for classifying obesity compared to the percentage of fat mass (%FM) assessed by Dual-Energy X-ray Absorptiometry (DXA) in a Chilean sample of children and adolescents; Material and Methods: The subjects studied included 280 children and adolescents (125 girls and 155 boys) aged 8 to 17 years. Weight and height were measured. The BMI was calculated. Two international references (IOFT and WHO) were used as cut-off points. The %FM was assessed by DXA. The receiver operating characteristic (ROC) curve was used to assess the performance of BMI in detecting obesity on the basis of %FM; Results: A high correlation was observed between the %FM measured by the DXA and the Z-scores of IOTF and WHO scores in the Chilean adolescents separated by sex (r = 0.78–0.80). Differences occurred in both references (IOFT and WHO) in relation to the criteria (p &lt; 0.001). Both references demonstrated a good ability to predict sensitivity (between 84% and 93%) and specificity (between 83% and 88%) in both sexes of children and adolescents; Conclusions: A high correlation was observed between the Z-score of the BMI with the percentage of fat determined by the DXA. Despite this, the classifications using the different BMI cut-off points showed discrepancies. This suggests that the cut-off points selected to predict obesity in this sample should be viewed with caution