Body Composition is Strongly Associated With Cardiorespiratory Fitness in a Large Brazilian Military Firefighter Cohort: The Brazilian Firefighters Study.

Firefighting is associated with high-level physical demands and requires appropriate physical fitness. Considering that obesity has been correlated with decreased cardiorespiratory fitness (CRF) and that the prevalence of obesity may also be elevated within firefighters (FF), we analyzed the association between CRF and body composition (BC) in Brazilian military FF. We assessed 4,237 male FF (18-49 years) who performed a physical fitness test that included BC and CRF. Body composition was assessed by body mass index (BMI), body adiposity index (BAI), body fat percentage (BF%), and waist circumference (WC). CRF was assessed by the 12-minute Cooper test. Comparisons of VO2max between the BC categories were analyzed using the Mann-Whitney test, and the analysis was adjusted for age using the General Linear Model. The Spearman test was used for correlation analysis and the odds ratio (OR) was calculated to assess the odds of the unfit group (≤ 12 metabolic equivalents [METs]) for poor BC. Statistically significant differences were considered when p ≤ 0.05. Considering the BMI categories, 8 volunteers (0.2%) were underweight, 1,306 (30.8%) were normal weight, 2,301 (54.3%) were overweight, and 622 (14.7%) were obese. The VO2max was negatively correlated with age (rs = -0.21), BMI (rs = -0.45), WC (rs = -0.50), and BAI (rs = -0.35) (p < 0.001). Cardiorespiratory fitness was lower in the obese compared with the nonobese for all age categories (-3.8 ml · kg(-1) · min(-1); p < 0.001) and for all BC indices (-4.5 ml · kg(-1) · min(-1); p < 0.001). The OR of the unfit group having poor BC in all indices varied from 2.9 to 8.1 (p < 0.001). Despite the metabolically healthy obesity phenomenon, we found a strong association between CRF and BC irrespective of age and the BC method (BMI, BAI, WC, or BF%). These findings may aid in improving FF training programs with a focus on health and performance.

Genomic ancestry, self-reported "color" and quantitative measures of skin pigmentation in Brazilian admixed siblings.

A current concern in genetic epidemiology studies in admixed populations is that population stratification can lead to spurious results. The Brazilian census classifies individuals according to self-reported "color", but several studies have demonstrated that stratifying according to "color" is not a useful strategy to control for population structure, due to the dissociation between self-reported "color" and genomic ancestry. We report the results of a study in a group of Brazilian siblings in which we measured skin pigmentation using a reflectometer, and estimated genomic ancestry using 21 Ancestry Informative Markers (AIMs). Self-reported "color", according to the Brazilian census, was also available for each participant. This made it possible to evaluate the relationship between self-reported "color" and skin pigmentation, self-reported "color" and genomic ancestry, and skin pigmentation and genomic ancestry. We observed that, although there were significant differences between the three "color" groups in genomic ancestry and skin pigmentation, there was considerable dispersion within each group and substantial overlap between groups. We also saw that there was no good agreement between the "color" categories reported by each member of the sibling pair: 30 out of 86 sibling pairs reported different "color", and in some cases, the sibling reporting the darker "color" category had lighter skin pigmentation. Socioeconomic status was significantly associated with self-reported "color" and genomic ancestry in this sample. This and other studies show that subjective classifications based on self-reported "color", such as the one that is used in the Brazilian census, are inadequate to describe the population structure present in recently admixed populations. Finally, we observed that one of the AIMs included in the panel (rs1426654), which is located in the known pigmentation gene SLC24A5, was strongly associated with skin pigmentation in this sample.

Comparação entre o critério do CDC e outros indicativos de gordura corporal para avaliação do estado nutricional / Comparison between CDC criteria and other body fat indexes to assess nutritional status

Introdução: A obesidade está aumentando de forma alarmante sendo considerada uma verdadeira epidemia mundial; atinge todas as faixas etárias, especialmente as crianças. Nesse sentido, a utilização de métodos que sejam confiáveis e de fácil aplicação para o diagnostico da obesidade em crianças, torna-se essencial para a adoção de medidas necessárias. Objetivo: Comparar os indicadores de gordura corporal nas diferentes classificações nutricionais através do protocolo utilizado pelo CDC e verificar a associação entre estes indicadores. Metodologia: Foram avaliadas 1550 crianças (776 meninos e 774 meninas) com idades entre 7 e11 anos estudantes do ensino fundamental da cidade satélite de Taguatinga – DF. Para a classificação nutricional foi utilizado o Índice de Massa Corporal (IMC) baseado nos critérios de corte do Center For Disease Control and Prevention (CDC). Os outros indicadores de gordura corporal utilizados foram: as circunferências da cintura (CC) e do quadril (CQ) e a sua relação (RCQ); somatório de dobras cutâneas(SDCtrpa) e o percentual de gordura corporal (%GC). Para as analises estatísticas foram utilizados o teste t para amostras independentes, One way ANOVA, teste de Chi-quadrado (c²) e correlação de Pearson (p d” 0,05). Resultados: Foi encontrada maior prevalência de obesidade nos meninos (c² = 8,383; (1): p = 0,003). As medidas do IMC, CC, CQ, SDCtrpa e %GC apresentaram diferenças significativas para as quatro classificações nutricionais, enquanto que o RCQ só foi estatisticamente diferente entre o sobrepeso e obeso. Além disso, todos os indicadores apresentaram correlações significativas entre si. Conclusão: Tanto o IMC quanto os outros indicadores de gordura corporal apresentaram comportamento semelhantes nas diferentes classificações nutricionais. A escolha do protocolo proposto pelo CDC é adequada para a estratificação das classificações nutricionais na população do presente estudo...

Introduction: Obesity has achieved high levels in recent years. This fact is alarming since anyone can become fatty person, including children. In this way, reliable and available methods which can be used to identify this worldwide epidemic are very important to prevent it. Objective: The aim of this study was to compare different methods to identify nutritional status using CDC protocol as standard method and to verify their association. Methodolgy: a total of 1550 children (776-boys and 774-girls) aged 7-11-years were evaluated. All of them were primary school students in Taguatinga - DF city. Body mass index (BMI) cut-off points from Center for Disease Control and Prevention (CDC) was used to classify their nutritional status. Other methods to measure body fat were: waist circumference (WC); hip circumference (HC); Waist-to-hipratio (WHR); skin-fold thickness some (SSFT) and body fat percentage (%BF). The tests used for statistics analysis were: independent sample t test, One Way ANOVA, Chi-square (c²) and Pearson’s correlation (p d”0.05). Results: Body fat prevalence was higher in boys than in girls (c² = 8,383; (1): p = 0,003). BMI, WC, HC,SSFT and %BF were statistical significant among all nutritional classification, while WHR was only different between overweight and obesity. Furthermore, all methods were statistically correlated between them.