RESUMO
BACKGROUND/AIM: Healthy individuals present variable responses of the hypothalamic-pituitary-adrenal (HPA) axis induced by different patterns of physical training. The aim of this study was to evaluate whether prolonged low-grade physical training influences the HPA axis and also glucocorticoid receptor-alpha (GRalpha) mRNA levels in mononuclear cells of obese adolescents. METHODS: We studied 19 patients with BMI above the 95th percentile (male:female ratio 7:12) aged from 9.5 to 15.5 years. Patients underwent a 12-week physical exercise program. Before and after exercise, in vivo glucocorticoid sensitivity was determined by employing a very-low-dose intravenous dexamethasone suppression test, and in vitro GRalpha mRNA levels were evaluated by quantitative real-time PCR. RESULTS: After exercise there was a trend to reduce the in vivo glucocorticoid sensitivity (p = 0.071) and a significant increase in GRalpha mRNA levels (p = 0.025). CONCLUSION: For this subset of obese adolescents, prolonged low-grade physical training tended to reduce glucocorticoid sensitivity. The discrepancy of cortisol response to dexamethasone and the GRalpha mRNA measurement suggest a post-receptor phenomenon or should be related to target tissue-specific differences in glucocorticoid sensitivity. Future studies should address the adaptive GRalpha mRNA during different exercise protocols, and also the correlation of pituitary sensitivity with glucocorticoid target tissue sensitivity.
Assuntos
Terapia por Exercício , Obesidade/metabolismo , Obesidade/terapia , Aptidão Física/fisiologia , Receptores de Glucocorticoides/metabolismo , Adolescente , Glicemia , Composição Corporal , Dexametasona/farmacologia , Exercício Físico/fisiologia , Feminino , Humanos , Sistema Hipotálamo-Hipofisário/metabolismo , Insulina/sangue , Resistência à Insulina/fisiologia , Masculino , Obesidade/genética , Seleção de Pacientes , Sistema Hipófise-Suprarrenal/metabolismo , RNA Mensageiro/genética , RNA Mensageiro/metabolismo , Receptores de Glucocorticoides/genética , Reação em Cadeia da Polimerase Via Transcriptase ReversaRESUMO
A freqüência da obesidade na infância e adolescência aumentou nos últimos anos. Essa situação tem preocupado a área da saúde, não só pelas conseqüências promovidas pela obesidade na população em geral, mas pela imposição de prejuízos biopsicossociais, ainda na infância. O tratamento é bastante complexo, pois sua causa é multifatorial, exigindo atenção interdisciplinar. O presente trabalho teve como objetivo relatar o papel do professor de educação física na equipe de atendimento ambulatorial de crianças e adolescentes obesos. A atividade física, depois da taxa metabólica basal, é considerada o segundo maior componente do gasto energético diário. Diversos estudos demonstraram que a atividade física associada ao controle alimentar leva a melhores resultados do que essas ações isoladas. O aumento da atividade física é muito benéfico no tratamento de crianças e adolescentes obesos, pois permite maior ingestão alimentar e auxilia a preservar a massa magra. Entretanto, o exercício físico deve ser adaptado às condições de excesso de peso e de crescimento ósseo. Além desses cuidados, o profissional depara-se com a dificuldade de manter crianças e adolescentes em programa de exercício regular. Desse modo, a prescrição do aumento de movimento corporal após a anamnese da rotina diária de cada paciente foi a solução encontrada para, inicialmente, colocá-los em contato com o próprio corpo. Paralelamente, o professor de educação física auxilia a criança a encontrar um tipo de esporte que mais lhe agrade, dentro daqueles permitidos pelo seu excesso de peso e fase de crescimento. Geralmente, recomendamðse atividades que tenham baixo impacto, como nadar, caminhar e andar de bicicleta. O professor de educação física, como educador, deve fazer parte do atendimento multidisciplinar de crianças e adolescentes obesos.
The prevalence of childhood and adolescent obesity has increased in recent years. This fact has raised concern in the health care field because obesity in general causes many health problems in the population at large, and also because obesity has many bio-psycho-social implications during childhood. The treatment of obesity is very complex since this disease has multifactorial causes, requiring an interdisciplinary response from health care professionals. This study was conducted to evaluate the role of physical education teachers in a group of professionals treating obese children and adolescents. Physical activity, after basal metabolic rate, is considered the second largest component of daily energy expenditure. Various studies have shown that physical activity with control of food intake produces the best results in treating weight loss compared to either of these treatments used independently. The increase of physical activity is very beneficial in the treatment of obese children and adolescents since it allows for a greater intake of food and at the same time maintains lean body mass. However, the type of physical activity should be adapted to the conditions of each child given that the obese person has an excess amount of weight along with the presence of active bone growth. Besides these precautions, the professional often has to deal with the difficulty of keeping the child or adolescent in an active, regular program of physical activity. It was found that promoting an increase in overall physical activity through a detailed, personal evaluation of his/her daily routine allows each patient to become more in touch with his/her own body. At the same time physical education teachers assist the child to find a type of sport that is enjoyable to him/her, but within the constraints of his/her excess weight and period of growth. It is generally recommended that the activities of the obese child or adolescent be low impact, such as swimming, walking, or riding a bicycle. The physical education teacher is an educator and thus should used his/her abilities in the multidisciplinary treatment of obese children and adolescents.