ABSTRACT BACKGROUND: This study aimed to investigate the relationship between total and segmental bone mineral density (BDM) and physical activity (PA) in different domains (school, leisure and sports) among adolescents and children. DESIGN AND SETTING: Cross-sectional study in the Universidade Estadual Paulista Júlio de Mesquita Filho (UNESP). METHODS: The study sample consisted of 173 children and adolescents (10.31 ± 1.87 years). The BMDs for the whole body (WB) and the regions of the trunk and legs were measured using dual energy X-ray absorptiometry (DXA). PA was measured using the Baecke questionnaire. A regression model was used to analyze the relationship between all the BMDs and the different domains of PA. RESULTS: 41.5% of the adolescents had high percentages of body fat. Regarding the comparison between physically active and insufficiently active adolescents, there were no statistically significant differences in any BMD variables (P > 0.05). The BMD of the legs showed positive relationships with the total PA (β = 0.009; P = 0.013) and sports PA (β = 0.010; P = 0.049) after insertion of the confounders. Similarly, the WB BMD showed the same relationships (total PA: β = 0.005; P = 0.045; and sports PA: β = 0.008; P = 0.049). No relationship was found between leisure and school PA and any of the BMDs (P > 0.05). CONCLUSION: The results indicated that practice of sport was related to higher BMD values, independent of sex, age and body fatness.

Resumo A adoção de comportamentos de risco à saúde (reduzido nível de atividade física habitual, consumo inadequado de alimentos e nutrientes, entre outros) tem aumentado a prevalência de sobrepeso/obesidade, particularmente, em adolescentes. Assim, o número de disfunções e doenças metabólicas tem crescido nesta população. Portanto, o objetivo deste estudo foi identificar a prevalência de Síndrome Metabólica (SM) e analisar a sua associação com a prática esportiva e excesso de peso em adolescentes de 11 a 17 anos. Seiscentos e oitenta e três meninos (n = 301) e meninas (n = 382) foram selecionados aleatoriamente para comporem a amostra. A prevalência de SM foi estabelecida com base nos valores de glicose em jejum, triglicerídeos, lipoproteínas de alta densidade (HDL-c), circunferência de cintura e pressão arterial, de acordo com os pontos de corte recomendados pela Sociedade Brasileira de Cardiologia (2005). O estado nutricional, prática de esporte, nível socioeconômico e consumo de álcool foram analisados como fatores de risco associados a SM. A presença de um ou mais fatores de risco foi identificada em 39,5% e 22,5% da amostra, respectivamente. Os componentes da SM mais prevalentes foram HDL-c reduzida (44,7%), pressão arterial sistólica elevada (32,4%) e triglicérides elevado (18,6%). A presença de SM foi associada ao excesso de peso e a ausência da prática de esportes (P < 0,05). Os resultados indicaram uma prevalência total de SM na ordem de 5,4% em adolescentes de ambos os sexos. Adicionalmente, o excesso de peso e ausência da prática de esportes foram os principais fatores associados com a SM.

Abstract The adoption of health risk behaviors (low level of habitual physical activity and inadequate food and nutrient intake) has increased the prevalence of overweight/ obesity, particularly among adolescents. Thus, the prevalence of disorders and metabolic diseases has increased in this population. The aim of this study was to identify the prevalence of metabolic syndrome (MS) and to analyze its association with sport participation and overweight in adolescents aged 11 to 17 years. A total of 683 adolescents (301 boys and 382 girls) were randomly selected to compose the sample. The prevalence of MS was established based on fasting glucose, triglycerides, high-density lipoprotein (HDL-c), waist circumference, and blood pressure according to the cut-offs recommended by the Brazilian Society of Cardiology (2005). Nutritional status, sport participation, socioeconomic status, and alcohol consumption were analyzed as risk factors associated with MS. The presence of one or more risk factors was identified in 39.5% and 22.5% of the sample, respectively. The most prevalent MS components were low HDL-c (44.7%), high systolic blood pressure (32.4%), and elevated triglycerides (18.6%). The presence of MS was associated with both overweight and the lack of participation in sport ( P < 0.05). The results indicated an overall prevalence of MS of 5.4% in adolescent boys and girls. Furthermore, overweight and lack of sport participation were the main factors associated with MS.

Este estudo analisou a composição corporal e densidade mineral óssea de atletas da elite do futebol brasileiro e comparar as diferenças entre as posições de jogo. Oitenta e dois jogadores de futebol da primeira divisão do Brasil foram divididos de acordo com a posição de jogo. Goleiros (GL, n= 10), Defensores (DF, n= 10), Laterais (LT, n= 15), Centrais (CT, n= 25), Atacantes (AT, n= 22) e um grupo controle (CG, n= 72). Para estimar a massa livre de gordura (MLG), massa gorda (MG), percentual de massa gorda (%MG), massa livre de gordura de pernas (MLG-Pernas) e densidade mineral óssea (DMO), foi usado o DEXA. A posição LT (10.5 ± 5.2), CT (9.7 ± 4.0) e AT (9.9 ± 4.4) apresentaram menores valores de MG e %MG que os GL (17.3 ± 6.0) e GC (15.0 ± 5.3). Comparado a outras posições, a MLG foi maior nos GL (68.2 ± 10.9) e DF (64.6 ± 6.8) (p< 0.05). Todos os jogadores apresentaram diferenças significativas em relação ao grupo controle (p< 0.05). Em suma, conclui-se que atletas da elite do futebol brasileiro apresentaram significativamente maior MLG, MLG-Pernas, DMO e menor MG e %MG que o grupo controle.

This study analyzed the body composition and bone mineral density of elite Brazilian soccer players and compared its differences according to the player position. Eighty-two soccer players competing at Brazilian first division were split according to their field positions: Goalkeepers (GK, n= 10), Back-fielders (BF, n= 10), Lateral-mid?elders (LM, n= 15), Central-mid?elders (CM, n= 25), Forwards (FW, n= 22), and a Control Group (CG, n= 72) of university students. To estimate fat free mass (FFM), fat mass (FM), percentage of body fat (%FM), fat free mass of legs (FFM-Legs) and bone mineral density (BMD), a DEXA was selected. The positions LM (10.5 ± 5.2), CM (9.7 ± 4.0) and FW (9.9 ± 4.4) had lower values of FM and %FM than the GK (17.3 ± 6.0) and the control group (15.0 ± 5.3). Compared to the other positions, FFM was higher in the GK (68.2 ± 10.9) and BF (64.6 ± 6.8) (p< 0.05). All the soccer players were different from the CG (p< 0.05). Soccer players have an FFM, FFM-Legs and BMD significantly higher and FM and %FM lower than the control group.