Efeito do treinamento físico sobre os níveis circulantes de irisina em crianças saudáveis: determinação da correlação com marcadores antropométricos, composição corporal, aptidão física e perfil glicêmico

• Ano de defesa: 2016
• Autor(a) principal: Meneck, Franciele de [UNIFESP]
• Tipo de documento: Dissertação
• Tipo de acesso: Acesso aberto
• Idioma: por
• Instituição de defesa: Universidade Federal de São Paulo (UNIFESP)
• Palavras-chave em Português: Irisina; Crianças; Treinamento Físico; Composição Corporal; Aptidão Física; Perfil Glicêmico
• Link de acesso: https://sucupira.capes.gov.br/sucupira/public/consultas/coleta/trabalhoConclusao/viewTrabalhoConclusao.jsf?popup=true&id_trabalho=3914807; https://repositorio.unifesp.br/handle/11600/47106

Introduction: Irisin, a hormone recently discovered as myokine and adipokines, is involved in compensatory mechanisms for metabolic regulation, and appears to interact with physical training; in addition to being influenced by several phenotypic characteristics, such as body composition and glucose metabolism. Numerous investigations show the benefits of exercise training in healthy children and adolescents, however, to date, the functions of metabolism and irisin regulatory mechanisms are not completely understood. Objective: To evaluate the effect of physical training on the irisin levels in healthy children by investigating their interrelationship with anthropometric, metabolic, physical aptitude parameters and level of fitness. Methods: Eighty children (32 girls and 48 boys) were submitted to anthropometric measurements, body composition, motor tests and collection of biological materials for blood glucose levels, insulin and plasma irisin in two distinct periods in the pre-training, that is, basal conditions and after 10 weeks of physical training (4 times a week - 60 minutes duration with intensity between 65 and 85% of maximum heart rate). Continuous variables were tested using the Wilcoxon test for paired data and expressed as mean ± standard deviation (SD). Correlation analyses were performed between the variables of interest in the Spearman test for nonparametric data. Results: After the physical training period there was a significant decrease in circulating irisin, improved body composition and glycemic profile. Age, weight, BMI and body fat percentage were positively correlated with irisin levels in pre- and post-physical training. In addition, lean body mass and the VO2max showed a negative correlation with irisin levels in pre- and post-workout. When we consider the tests of physical fitness, we found that the circulating levels of irisin positively correlated with the strength test of the right lower and upper limb, only in the post-training period. In relation to the metabolic parameters, fasting plasma glucose, insulin and insulin resistance decreased after physical training, and we found positive correlation between circulating levels of irisin with insulin and HOMA-IR in both periods. Conclusion: The physical training program provided a significant reduction in circulating irisin levels, and improvements in metabolic, anthropometric and physical fitness parameters. The fact that irisin levels have a positive association with parameters that reflect a dysregulated metabolism may suggest a compensatory role of irisin.