ABSTRACT
ABSTRACT Objective: To associate the Maximal Oxygen Uptake (VO2max) with body fat percentage (%BF), and to establish the best VO2max cutoff point for predicting risk %BF in teenagers. Methods: This study was carried out with 979 subjects aged 10 to 18.8 years, 556 (56.8%) girls. The 20 m shuttle run protocol determined the VO2max, which was analyzed in quintiles and in a numeric scale. Cutaneous fold equations determined the %BF, later classified as risk to health/obesity when >25 in girls and >20 in boys. Regression method was used - Odds Ratio (OR) and Receiver Operating Characteristics Curve (ROC curve) with α <5%. Results: From the total number of valid cases, 341 (65.6%) girls and 202 (53.2%) boys presented %BF of risk, and a larger proportion of %BF of risk was observed in the 1st quintile of the VO2max for both genders. There was inverse association between VO2max and %BF of risk from the 4th quintile (OR 1.84, 95%CI 1.05-3.24) until the 1st quintile (OR 4.74, 95%CI 2.44-9.19) for girls, and from the 2nd quintile (OR 2.99, 95%CI 1.48-6.00) until the 1st quintile (OR 5.60, 95%CI 2.64-11.87) for boys. As analytic highlights, VO2max Cutoff points for prediction of %BF of risk were ≤40.9 mL/kg-1/min-1 (AUC: 0.65; p<0.001) for girls and ≤44.8 mL/kg-1/min-1 (AUC: 0.66; p<0.001)for boys.. Conclusions: VO2max was inversely associated to the %BF, and VO2max cutoff points for prediction of %BF of risk are important results to generate action to fight early obesity.
RESUMO Objetivo: Associar o Consumo Máximo de Oxigênio (VO2máx) com o % de Gordura Corporal (%GC) e estabelecer o melhor ponto de corte do VO2máx para a previsão do %GC de risco em adolescentes. Métodos: Estudo realizado com uma amostra de 979 sujeitos entre 10 e 18,8 anos, sendo 556 (56,8%) meninas. O protocolo shuttle run de 20 m determinou o VO2máx, que foi analisado em quintil e escala numérica. Equações de dobras cutâneas determinaram o %GC, posteriormente classificado como risco à saúde/obesidade quando >25, para meninas, e >20, para meninos. Utilizou-se regressão - Odds Ratio (OR) e Curva Característica de Operação do Receptor (curva ROC) com α <5%. Resultados: Do total de casos válidos, 341 (65,6%) meninas e 202 (53,2%) meninos apresentaram %GC de risco, e constatou-se maior proporção do %GC de risco no 1º quintil do VO2máx para ambos os sexos. Houve associação inversa entre VO2máx e %GC de risco do 4º quintil (OR 1,84, IC95% 1,05-3,24) até o 1º quintil (OR 4,74, IC95% 2,44-9,19) para meninas, e do 2º quintil (OR 2,99, IC95% 1,48-6,00) até o 1º quintil (OR 5,60, IC95% 2,64-11,87) para meninos. Pontos de corte do VO2máx para previsão do %GC de risco ≤40,9 mL/kg-1/min-1 (Area Under the Curve (Área Sob a Curva) - AUC: 0,65; p<0,001) para meninas e ≤44,8 mL/kg-1/min-1 (AUC: 0,66; p<0,001) para meninos foram destaques analíticos. Conclusões: VO2máx esteve associado inversamente ao %GC, e os pontos de corte do VO2máx para a previsão do %GC de risco são resultados importantes para ações de combate à obesidade precoce.
Subject(s)
Humans , Male , Female , Child , Adolescent , Oxygen Consumption , Body Composition , Adipose Tissue , Cardiorespiratory Fitness/psychology , Brazil/epidemiology , Body Mass Index , Anthropometry/methods , Cross-Sectional Studies , Predictive Value of Tests , Risk Assessment/methods , Obesity/diagnosis , Obesity/physiopathology , Obesity/prevention & control , Obesity/epidemiologyABSTRACT
ABSTRACT BACKGROUND: Our aim was to analyze multilevel correlates of cardiorespiratory fitness (CRF) according to sex, nutritional status and maturity status among adolescents. DESIGN AND SETTING: Cross-sectional study conducted in public schools. METHODS: This was a cross-sectional study on 1,209 adolescents aged between 10 and 17 years. CRF was estimated from the 20-meter shuttle run test. Anthropometric data on body mass index and waist circumference were obtained. Somatic maturation was assessed from the peak height velocity. Questionnaires were used to evaluate socioeconomic variables (family income, parents' education level and number of siblings) and behavioral variables (physical activity, screen time and alcohol and tobacco consumption) among the parents and adolescents. RESULTS: Boys, adolescents with normal weight and on-time maturers presented greater CRF (P < 0.05). Concerning socioeconomic correlates, girls (tobacco smoking, alcohol consumption, physical activity and screen time), adolescents with normal weight (alcohol consumption, physical activity and screen time), and on-time maturers (alcohol consumption, physical activity during childhood and habitual physical activity) demonstrated higher numbers of behavioral correlates with CRF. Normal-weight adolescents presented a higher number of biological correlates (chronological age, age at peak height velocity and waist circumference). CONCLUSIONS: Different correlates were observed according to sex, nutritional status and somatic maturation status. However, habitual physical activity, waist circumference and chronological age seemed to be the strongest factors associated with cardiorespiratory fitness among adolescents.