Efeitos do exercício físico sobre a função cognitiva e os níveis plasmáticos de BDNF em mulheres idosas

Abstract

Introduction: Physical activity has been proposed as a promising intervention to improve cognition and decrease the risk of dementia in older adults. Brain-derived neurotrophic factor (BDNF) seems to mediate, at least partially, these effects of exercise. However, intervention studies of the effects of multimodal exercises on cognition and BDNF levels are scarce and composed by small samples. Thus, the generalization of the conclusions of these studies depends on the reproducibility of the results. Objective: to contribute to the knowledge on the field, the present study evaluated the effects of a physical activity intervention composed by muscle strengthening and aerobic conditioning on BDNF levels and cognition in older women. Methods: Twenty-two independent and non-demented subjects (≥ 75 years) were assigned to a three-month physical activity intervention (60 min exercise sessions three times a week, 30 min of muscle strengthening and 30 min of aerobic activity) or to a control condition (n= 10, no exercise). The clinical parameters (anxiety and depression symptoms), neuropsychological (Digit Span, Stroop, Trail Making and Contextual Memory tests), physical (upper and lower limb strength, aerobic conditioning) and physiological (serum BDNF) parameters were evaluated immediately before, one and three-months after starting intervention. Results: the control group had stable levels for all measured variables, whereas the intervention group improved on physical fitness, depressive symptoms, cognitive performance and BDNF levels. Moreover, a linear regression identified an association between aerobic conditioning and BDNF levels. Conclusion: The combination of muscle strengthening and aerobic conditioning was able to improve cognitive performance and increase BDNF levels. Aerobic conditioning seems to be an important mediator of these results.