Efeitos do exercício físico no balanço entre estresse oxidativo e defesas antioxidantes e suas possíveis relações com a integridade cognitiva de idosos

• Autor(a) principal: Schames, Maurício Lemieszek
• Data de Publicação: 2014
• Tipo de documento: Tese
• Idioma: por
• Título da fonte: Biblioteca Digital de Teses e Dissertações da PUC_RS
• Texto Completo: http://tede2.pucrs.br/tede2/handle/tede/2737
• topic: GERONTOLOGIA; IDOSOS; EXERCÍCIOS FÍSICOS - ASPECTOS DA SAÚDE; COGNIÇÃO; ESTRESSE OXIDATIVO; CNPQ::CIENCIAS DA SAUDE::MEDICINA

Introduction: the Oxidative Stress Theory suggests that, throughout an individual s life, an accumulation of free radicals, produced by mitochondria, generating a progressive disequilibrium between prooxidant and antioxidant system can be observed. The oxidative stress may cause an increase in the protein damages and trigger possible changes and inflammations, as well as contribute to the development of many diseases, such as neurodegenerative. Doing physical exercises may increase the tolerance of the tissue, related to the damages, caused by oxidative stress, as well as the enzymatic defenses. Objective: evaluate the effect of the regular and oriented physical exercises, considering cognitive and plasmatic parameters of the oxidative stress and antioxidant defenses. Methodology: there were 28 elderly individuals that participated in the study, that were divided in two experimental groups: the elderly group that was not doing any oriented physical activity (n=11) and the other group that was doing an oriented physical activity (n=17). Instruments for screening dementia, such as Mini Mental State Examination, for depression, the Beck Scale for Depression, the International Physical Activities Questionnaire, to get data related to daily physical exercise, and the Wisconsin Card Sorting Test, to evaluate the working memory, were used in this study. Blood was collected, in order to analyze the oxidative stress as well as the antioxidant markers. Results: groups did not show any relevant differences, considering age, education and social and economic aspects, as well as in the scores of the instruments for screening depression and dementia. Any significant differences between the two groups, related to the body mass, caloric content, protein, lipid, carbohydrate, and diet vitamins A, were verified. Since any relevant differences were seen between the two groups in the oxidative stress and cognitive performance parameters, all the volunteers, who participated of the study, were gathered in only one group, in order to verify the possible relations between those variables. Thus, linear regressions were performed, considering, as predictor variables, the lipid peroxidation, the protein damage and the total antioxidant activity, and, as dependent variables, the scores that were gotten in each one of the neuropsychological tests. The only statistically relevant result [p=0.011] found was the relation between the total antioxidant activity and the number of perseverative errors in WCST [B= - 0.71]. Conclusions: there were not verified any significant differences between the groups, probably because the difference of the level of the physical activity was very small. In future studies, a higher number of volunteers and groups, with marked differences between the level of the physical exercises, should be added as well as some physiological parameters, to identify the level of the physical activity that was performed and observe their effect on the cognitive aspects and plasmatic parameters of oxidative stress and the antioxidant defenses, and verify their possible association to elderly people and their cognitive integrity