Bone parameters and food intake of adolescent athletes practicing different modalities

Orientadores: Gil Guerra Júnior, Anderson Marques de MoraesDissertação (mestrado) - Universidade Estadual de Campinas, Faculdade de Ciências MédicasResumo: Estrutura da dissertação: No presente estudo optou-se pelo "Modelo Alternativo", sendo assim, a dissertação foi composta por introdução geral, objetivos, metodologia, resultados (capítulo 1 e 2), discussão geral e conclusão. A introdução abordou os principais aspectos relacionados a massa óssea (MO) e geometria óssea (GO), como a puberdade, composição corporal, consumo alimentar e principalmente a prática de esportes. Objetivo: No presente estudo foram delineados objetivos de acordo com as modalidades praticadas para cada sexo, portanto dividido em dois: (1) para as meninas, verificar o efeito da prática esportiva de ginástica artística (GR) e ginástica rítmica (GR) comparado ao efeito da carga mecânica promovida por meio do excesso de peso na massa óssea e na geometria de quadril e; (2) nos meninos, avaliar a associação do consumo alimentar e composição corporal com os parâmetros ósseos de adolescentes jogadores de futebol. Metodologia: Os dois estudos tiveram delineamento transversal, o primeiro com meninas da ginástica rítmica (GR, n=14), ginástica artística (GA, n=7) e grupo controle (CO, n=9), e o segundo com 148 meninos adolescentes jogadores de futebol. A composição corporal e a massa óssea foram medidas por absorciometria de dupla energia por raios X, compreendendo as medidas óssea de densidade mineral óssea (DMO, em g/cm2) e o conteúdo mineral ósseo (CMO, em g) do corpo total sem cabeça (CTSC), coluna lombar posterior (L1-L4) e colo do fêmur direito (CFD), além da composição corporal pela massa magra (MM, em kg) e massa gorda (MG, em kg). A geometria óssea foi mensurada por meio do software Advanced Hip Assessment. A maturação somática foi estimada pelas equações do pico de velocidade de crescimento (PVC, em anos) de acordo com sexo. Informações sobre o consumo alimentar foram obtidas por meio um recordatório alimentar de 24 horas. Resultados: No estudo do grupo feminino, observou-se que o CO apresentou maior nível de MG que a ginástica rítmica, porém não houve diferença quanto a MO e GO entre os grupos. No segundo estudo, com os atletas de futebol, foi verificado média de valor de escore z de todas as regiões analisadas acima da média da população. A MM foi a melhor preditora de praticamente todos as variáveis de MO e GO. A proteína foi preditora negativa, para alguns parâmetros ósseos e a MG foi preditora positiva, com baixo poder de explicação, para o IFF. Conclusão: No primeiro estudo com as meninas adolescentes (capítulo 1), não houve diferença significativa nos parâmetros ósseos entre a prática esportiva e a carga mecânica imposta pelo excesso de peso, provavelmente pela influência positiva da MG neste último grupo. No estudo com os atletas de futebol (capítulo 2), a MM foi preditora positiva, com um forte poder de explicação da variabilidade da maioria dos parâmetros ósseos (MO e GO), e a proteína, foi preditora negativa, de algumas variáveis de massa óssea e preditora positiva da geometria óssea. A prática contínua de esporte durante a puberdade, a manutenção/ aumento da MM, principalmente de meninas, assim como o consumo adequado de proteína, entre outros nutrientes, devem ser um objetivo crucial para um melhor desfecho da saúde óssea em adolescentesAbstract: Dissertation structure: In the present study, the "Alternative Model" was chosen, therefore, the dissertation was composed of general introduction, objectives, methodology, results (chapters 1 and 2), general discussion and conclusion. The introduction addressed the main aspects related to bone mass and bone geometry, such as puberty, body composition, food consumption and especially the practice of sports. Objective: In the present study, objectives were outlined according to the modalities practiced for each sex, therefore divided into two: (1) for girls, to verify the effect of artistic and rhythmic gymnastics sports practice compared to the effect of the mechanical load promoted through excess weight in bone mass and hip geometry and; (2) for boys, to evaluate the association of food consumption and body composition on bone parameters in adolescent soccer players. Methods: The two studies were cross-sectional, the first with girls in rhythmic gymnastics (n=14), artistic gymnastics (n=7) and the control group (n=9), and the second with 148 soccer players. Body composition and bone mass were measured by dual-energy X-ray absorptiometry, comprising bone measurements of bone mineral density and bone mineral content of the total body without head, posterior lumbar spine and right femoral neck. Bone geometry was measured using the Advanced Hip Assessment software. Maturation was estimated by the equations of peak growth velocity according to sex. Food consumption was collected through a 24-hour food record. Results: In the study of the female group, it was observed that the control group had a higher level of fat mass than rhythmic gymnastics, however there was no difference in bone mass and bone geometry between the groups. In the second study, with soccer athletes, the average z-score value of all the regions analyzed were above the population average. Lean mass was the best predictor of practically all bone mass and bone geometry variables. Protein was a negative predictor for some bone parameters, and fat mass was a positive predictor for the femur strength index. Conclusion: In the first study with adolescent girls (chapter 1), there was no significant difference in bone parameters between sports practice and the mechanical load imposed by excess weight, probably due to the positive influence of fat mass in this last group. In the study with soccer athletes (chapter 2), lean mass was a positive predictor, with a strong power to explain the variability of most bone parameters, and protein, was a negative predictor of some variables of bone mass and bone geometry. The continuous practice of sport during puberty, the maintenance/ increase of lean mass, mainly in girls, as well as the adequate consumption of protein, among other nutrients, must be a crucial objective for a better health outcome bone in adolescentsMestradoSaúde da Criança e do AdolescenteMestra em Ciências001CAPE

Prediction of fat-free mass from body surface area in young basketball players

Abstract Background Fat Free Mass (FFM) is an important and essential indicator in various sports populations, since greater muscle and bone mass generates greater strength, endurance and speed in athletes. Objective The purpose of the study was to validate Body Surface Area (BSA) as an anthropometric indicator to estimate FFM in young basketball players. Methods A descriptive cross-sectional study was carried out in 105 male basketball players of the Brazilian Basketball Confederation of Sao Paulo (Campinas), Brazil. The age range was 11 to 15 years. Weight and height were evaluated. BSA, body mass index (BMI) and maturity status (MS) were calculated. Total body scanning was performed by dual X-ray absorptiometry (DXA). The components were extracted: Fat mass (FM), Fat free mass (FFM), percentage of fat mass (%FM) and bone mass (BM). The data were analyzed using the correlation coefficient of concordance (CCC) in terms of precision and accuracy. Results Three regression equations were generated: equation 1 had age and body weight as predictors [FFM= -30.059+(2.926*age)+(0.625*Weight)] (R2 = 92%, precision = 0.96 and accuracy = 0.99), equation 2 used age and BSA [FFM=-45.719+(1.934*age)+(39.388*BSA)] (R2 = 94%, precision = 0.97 and accuracy = 0.99) and equation 3 was based on APHV and BSA [FFM=-15.284+(1.765*APHV)+(37.610*(BSA)] (R2 = 94%, precision = 0.96 and accuracy = 0.99). Conclusions The results suggest the use of anthropometric equation using decimal age and BSA to estimate FFM in young basketball players. This new method developed can be used to design, evaluate and control training programs and monitor the weight status of athletes