Ezequiel Moreira Gonçalves

Body composition in taller individuals using DXA: A validation study for athletic and non-athletic populations

Abstract Dual energy X-ray absorptiometry (DXA) cannot be used to evaluate participants taller than the scan area. We aimed to analyse the accuracy of bone mineral content, fat mass, and lean mass assessed with DXA whole-body scan and from the sum of two scans (head and trunk plus limbs). Participants were 31 athletes (13 males and 18 females) and 65 non-athletes (34 males and 31 females), that fit within the DXA scan area. Three scans were performed using a Hologic Explorer-W fan-beam densitometer: a whole-body scan used as the reference; a head scan; and a trunk and limbs scan. The sum of the head scan and the trunk and limbs scan was used as the alternative procedure. Multiple regression and agreement analysis were performed. Non-significant differences between methods were observed for fat mass (0.06 kg) and lean mass (−0.07 kg) while bone mineral content from the alternative procedure differed from the reference scan (0.009 kg). The alternative procedure explained > 99% of the variance in the reference scan and low limits of agreement were observed. Precision analysis indicated low pure errors and the higher coefficients of variation were found for fat mass (whole-body: 3.70%; subtotal: 4.05%). The method proposed is a valid and simple solution to be used in individuals taller than the DXA scan area, including athletes engaged in sports recognised for including very tall competitors.

Is bioelectrical impedance spectroscopy accurate in estimating total body water and its compartments in elite athletes

Background: Bioelectrical impedance spectroscopy (BIS) provides an affordable assessment of the bodys various water compartments: total body water (TBW), extracellular water (ECW) and intracellular water (ICW). However, little is known of its validity in athletes. Aim: To validate TBW, ECW and ICW by BIS in elite male and female Portuguese athletes using dilution techniques (i.e. deuterium and bromide dilution) as criterion methods. Subjects and methods: Sixty-two athletes (18.5 ± 4.1 years) had TBW, ECW and ICW assessed by BIS during their respective pre-season. Results: BIS significantly under-estimated TBW by 1.0 ± 1.7 kg and ICW by 0.9 ± 1.9 kg in relation to the criterion methods, with no differences observed for ECW. The values for the concordance correlation coefficient were 0.98 for TBW and ECW and 0.95 for ICW. Bland-Altman analyses revealed no bias for the various water compartments, with the 95% confidence intervals ranging from − 4.8 to 2.6 kg for TBW, − 1.5 to 1.6 kg for ECW and − 4.5 to 2.7 kg for ICW. Conclusions: Overall, these findings demonstrate the validity of BIS as a valid tool in the assessment of TBW and its compartments in both male and female athletes.

Influence of programmed physical activity on body composition among adolescent students

OBJECTIVE To verify the influence of programmed physical activity on body composition among adolescent students during 1 school year. METHODS The sample included 383 students (age range: 10 to 15 years) separated into two groups: 186 cases (96 male and 90 female) and 197 controls (108 male and 89 female). This was an intervention study with pre- and post-test assessments in which interventions consisted of programmed physical activity; the control group had conventional school physical education. Body composition was assessed by anthropometric measurements, body mass index (BMI), body fat percentage and fat and lean body mass. RESULTS In the case group, subscapular skinfold thickness, BMI, body fat percentage and fat body mass remained stable; there were significant reductions in tricipital skinfold thickness and in abdominal perimeter among girls and significant increases in arm, waist and calf perimeters and in lean body mass. In the control group, there were significant increases in BMI, tricipital skinfold thickness, abdominal perimeter and fat body mass among girls. At post-test, overweight and obesity significantly decreased among case group subjects, but not among controls. CONCLUSION Programmed physical activity resulted in improvement or maintenance of body composition parameters and in reduction of overweight and obesity in the intervention group.

Efeito da atividade física programada sobre a composição corporal em escolares adolescentes

Objetivos: Verificar o efeito da atividade fisica programada na escola sobre a adiposidade corporal e a aptidao fisica de adolescentes, durante um ano letivo. Casuistica e Metodos: Amostra foi composta de 383 alunos, divididos em dois grupos: casos com 186 (96 meninos e 90 meninas) e controles com 197 (108 meninos e 89 meninas), com idade entre 10 a 15 anos. Trata-se de estudo de intervencao com pre e pos-teste com um ano de duracao, no qual o grupo casos foi submetido a atividade fisica programada e o grupo controles com aulas convencionais de educacao fisica escolar. A composicao corporal foi avaliada por medidas antropometricas e calculos de indice de massa corporal (IMC), percentual de gordura e massas gorda e magra. A aptidao fisica foi avaliada por testes de flexibilidade, forca e corrida. Resultados: O grupo casos apresentou estabilidade na prega cutânea subescapular, IMC, percentual de gordura e massa gorda; reducao significativa na prega cutânea triciptal, perimetro do abdome nas meninas e aumento significativo dos perimetros do braco, cintura e panturrilha e massa magra. No grupo controles houve aumento do IMC, da prega cutânea triciptal, do perimetro do abdome e da massa gorda nas meninas. O grupo casos e os meninos apresentaram melhora significativa nos testes de forca e corrida. O grupo casos apresentou diminuicao significativa na proporcao de sobrepesos e obesos no pos em relacao ao pre-teste, o mesmo nao ocorrendo no grupo controles. Conclusoes: A atividade fisica programada resultou em melhoria ou manutencao nas variaveis da composicao corporal e aptidao fisica, e reducao da frequencia de sobrepeso e obesidade no grupo submetido a intervencao Abstract

Growth curves in Down syndrome: implications for clinical practice.

Growth curves have been developed for individuals with Down syndrome (DS) in several countries. However, in order to facilitate the preparation of clinical guidelines it is necessary to verify the eligibility of these curves. The search was conducted according to the PRISMA method (Preferred Reporting Items for Systematic reviews and Meta‐Analyses). It was conducted between July 2012 and June 2013 in MEDLINE/PubMed and BIREME. The inclusion and exclusion criteria were applied to identify the studies and a total of 16 relevant articles were selected. The aspects analyzed in the articles consisted of sample size, number of observations, age group, anthropometric variables, standard deviation scores (SDS), type of study, collection and analysis of data, participants, inclusion/exclusion criteria and outcomes. The mean, standard deviations (SDs) and percentiles for sex and age were used to develop the curve of weight, height, and head circumference. The individuals with DS presented growth between −0.4 and −4.0 SDS in comparison to healthy controls. The variation in these observations can be explained by genetic differences, secular trends in growth and disease status. Regarding the limitations identified, it was observed that most of the studies did not provide data concerning the number of individuals and observations, mean values and respective SDs by sex and age. In addition, most studies did not use LMS methods to evaluate asymmetry, the median and data variability. In conclusion, the results of this review demonstrated that in order to avoid false diagnoses in children and adolescents with DS new growth curves must be developed.

Abnormalities in body composition and nutritional status in HIV-infected children and adolescents on antiretroviral therapy.

This cross-sectional study aimed to compare growth, nutritional status and body composition outcomes between a group of 94 HIV-infected children and adolescents on antiretroviral therapy (ART) and 364 healthy controls, and to evaluate their association with clinical and lifestyle variables within the HIV-infected group. When compared with the control group, HIV patients had higher risk of stunting (odds ratio [OR] 5.33, 95% confidence interval [CI]: 2.83–10.04) and thinness (OR 4.7, 95% CI: 2.44–9.06), higher waist-to-hip ratios (medians 0.89 versus 0.82 for boys and 0.90 versus 0.77 for girls, P < 0.001), and lower prevalence of overweight or obesity (OR 0.33, 95% CI: 0.14–0.78). Protease inhibitor usage was associated with thinness (OR 3.51, 95% CI 1.07–11.44) and lipoatrophy (OR 3.5, 95% CI 1.37–8.95). HIV-infected children on ART showed significant nutritional status and body composition abnormalities, consistent with the severity of vertical HIV infection and the consequences of prolonged ART.

Influência da composição corporal sobre a massa óssea em crianças e adolescentes

OBJECTIVE: To evaluate the influence of body composition on bone mass in children and adolescents. METHODS: A cross-sectional study with 267 healthy students of both sexes (141 males and 126 females) aged 8 to 18 years. Weight, height, body mass index, lean mass, fat mass, fat mass index, body fat percentage, waist and hip circumferences, and waist-to-hip ratio were evaluated. Bone mass was assessed using ultrasound of hand phalanges (DBM Sonic BP IGEA, Carpi, Italy). RESULTS: Females showed greater bone mass in relation to males with ad vances in age and pubertal stage. In both sexes, the bone mass showed significant and positive correlations with age, weight, height, body mass index, lean mass, waist and hip circumfer ences; and negative correlations with waist-to-hip ratio. In females, there was also a positive correlation with fat mass, fat mass index, and body fat percentage. Age and lean mass were predictors for bone mass in males, and age, pubertal stage and fat mass index were predictors in females. CONCLUSION: The correlation between bone mass and body composition occurred in both sexes, with lean mass and fat mass index being the predictor of bone mass in males and females, respectively.

Assessment of total body water and its compartments in elite judo athletes: comparison of bioelectrical impedance spectroscopy with dilution techniques

Abstract Bioelectrical impedance spectroscopy (BIS) is an inexpensive and non-invasive technique to measure total body water (TBW), extracellular water (ECW), and intracellular water (ICW). The purpose of this study was to validate TBW, ECW and ICW assessed by BIS, using dilution techniques as the reference method (REF) in elite judo athletes. Thirty-two Portuguese elite male judo athletes were evaluated during a period of weight stability. TBW, ECW and ICW were assessed by BIS (Xitron 4000). Deuterium and bromide dilution techniques were used as the criterion method for measuring TBW and ECW, while ICW was calculated as the difference between the two. BIS explained 96%, 77% and 94% of the total variability from REFs for TBW, ECW and ICW, respectively. BIS also demonstrated high precision (ρ ≥ 0.88) and accuracy (Cb = 0.98), with a minimum concordance coefficient correlation of 0.87 for ECW. The mean bias demonstrated that BIS slightly overestimated the REF in 1.1 kg (2.3%), 0.3 kg (1.6%) and 0.8 kg (2.7%) for TBW, ECW and ICW, respectively. The 95% limits of agreement ranged from −1.2 to 3.3 kg in TBW, from −1.8 to 2.4 kg in ECW and from −1.0 to 2.6 kg in ICW. A non-significant trend was found between the difference and the mean of reference and alternative methods. These findings highlight the efficacy of BIS as a valid non-biased tool for the assessment of TBW and its compartments in elite male judo athletes, during a period of weight stability.

Total body water and its compartments are not affected by ingesting a moderate dose of caffeine in healthy young adult males

Acute and chronic caffeine intakes have no impact on hydration status (R.J. Maughan and J. Griffin, J. Hum. Nutr. Diet. 16(6): 411-420, 2003), although no research has been conducted to analyze the effects using dilution techniques on total-body water (TBW) and its compartments. Therefore, the aim of this study was to investigate the effects of a moderate dose of caffeine on TBW, extracellular water (ECW), and intracellular water (ICW) during a 4-day period in active males. Thirty men, nonsmokers and low caffeine users (<100 mg·day(-1)), aged 20-39 years, participated in this double-blind, randomized, crossover trial (ClinicalTrials.gov: No. NCT01477294). The study included 2 conditions (5 mg·kg(-1)·day(-1) of caffeine and placebo (malt-dextrin)) of 4 days each, with a 3-day washout period. TBW and ECW were assessed by deuterium oxide and sodium bromide dilution, respectively, whereas ICW was calculated as TBW minus ECW. Body composition was assessed by dual-energy X-ray absorptiometry. Physical activity (PA) was assessed by accelerometry and water intake was assessed by dietary records. Repeated-measures analysis of variance (ANOVA) was used to test main effects. No changes in TBW, ECW, or ICW and no interaction between the randomly assigned order of treatment and time were observed (p > 0.05). TBW, ECW, and ICW were unrelated to fat-free mass, water ingestion, and PA (p > 0.05). These findings indicate that a moderate caffeine dose, equivalent to approximately 5 espresso cups of coffee or 7 servings of tea, does not alter TBW and fluid distribution in healthy men, regardless of body composition, PA, or daily water ingestion.

Minimum Time to Achieve the Steady State and Optimum Abbreviated Period to Estimate the Resting Energy Expenditure by Indirect Calorimetry in Healthy Young Adults

BACKGROUND The optimum abbreviated period for measurement by indirect calorimetry (IC) to estimate the resting energy expenditure (REE), including the acclimation period, in healthy individuals has not been established. This study aimed to determine the acclimation time required to achieve the REE steady state during a 30-minute IC measurement and to define the optimum abbreviated measurement period in the steady state to estimate the REE in healthy young adults. METHODS Thirty-nine volunteers (27 men and 12 women; age, 18-31 years) were recruited. The REE was obtained by IC over 30 minutes. Friedmans test was used to compare the coefficient of variation (CV%) among all 5-minute intervals (REE5). To compare the REE values obtained during the first REE5 interval in the steady state with the REE average values of the subsequent measurements, Student paired t test, linear regression, and Bland-Altman test were used. RESULTS The CV% of the first REE5 (mean ± standard deviation: 19.9% ± 13.2%) was significantly higher (P < .0001) than that of all other REE5 (second REE5: 7.4% ± 3.8%; third: 7.8% ± 5.2%; fourth: 7.1% ± 3.9%; fifth: 8.0% ± 5.7%; sixth: 8.0% ± 4.5%). No significant difference was found between the second REE5 and the REE average values of the last 20 minutes. The second REE5 explained 90% of the REE average of the last 20 minutes, with the 95% limits of agreement by the Bland-Altman test ranging from -142.92 to 150.44 kcal/d. CONCLUSION Ten minutes can be used as an abbreviated alternative for IC measurements in healthy young adults, and values of the first 5-minute interval should be discarded.