Exercício físico multifuncional, concentrações plasmáticas de BDNF e desempenho cognitivo de idosos com doença de Alzheimer

Abstract

Despite recent evidence, little is known about the Brain Derived Neurotrophic Factor (BDNF), Alzheimer's disease (AD) and cognition. BDNF is a protein that acts on neuroplasticity and neurogenesis and, therefore, can contribute to cognitive functionality in humans. In this sense, studies show that elderly people with AD have lower concentrations of this biomarker. On the other hand, in healthy elderly people, physical exercise (PE) has been considered effective in raising BDNF concentrations, however, there is still a gap in the literature regarding the association between plasma BDNF concentrations in elderly people with AD with different levels of physical activity (PAL). In addition, PE, especially the multifunctional one, has been considered an important strategy to reduce the negative impacts on the daily lives of elderly people with AD. Thus, this dissertation was developed in the format of two articles. Study 1 aimed to verify the main effects of multifunctional physical exercise (MPE) protocols in AD and to describe the methodological characteristics used in research in the last 10 years on MPE and AD. A search was performed in the Scientific Electronic Library Online (SciELO), National Library of Medicine (PUB MED) databases via MEDLINE and Web of Science. This study adopted the items and recommendations of the Preferred Reporting Items for Systematic reviews and Meta-Analyzes (PRISMA) and the selected articles were analyzed according to the methodological characteristics. Of the 2005 articles found initially, 6 studies were included in this review. Evidence suggests that the practice of MPE can have positive effects on cognitive, motor and behavioral functionality when the motor task is performed concurrently with the cognitive task. In addition, new studies are suggested to better control their methods. Study 2 aimed to compare the plasma concentrations of BDNF and PAL in the cognitive performance of elderly people with physically active AD, with elderly people with insufficiently active AD. 34 elderly people diagnosed with AD in the mild and moderate stages participated in the study. The elderly were divided into two groups: 16 elderly people with physically active AD (G1) and 18 elderly people with insufficiently active AD (G2). The elderly were submitted to the following assessment instruments: Anaminese, Clinical Dementia Assessment Score, Mini Mental State Examination, Clock Drawing Test, Frontal Assessment Battery, Semantic Verbal Fluency Test, Geriatric Depression Scale, Activity Questionnaire Pfeffer functionalities, Modified Baecke Questionnaire for the Elderly and blood collection to obtain plasma BDNF concentrations. For the statistical analysis, the Shapiro Wilk test was used to verify the data distribution and ANOVA One-way to compare the variables between the groups. Older adults with physically active AD when compared to older adults with insufficiently active AD havebetter cognitive performance and less depressive symptoms. The worst cognitive performance in elderly people with insufficiently active AD can be influenced by education and depressive symptoms. Elderly people with physically active AD presented plasma BDNF concentrations similar to elderly people with insufficiently active AD