ARTIGO DE REVISÃO | REVIEW ARTICLERESUMO O presente estudo de revisão narrativa teve como objetivos: a) rever os termos operacionais utilizados para a caracterização do comportamento sedentário; b) descrever as implicações para a saúde; e c) os principais métodos de avaliação do comportamento sedentário. Comportamento sedentário é o termo direcionado para as atividades que são realizadas na posição deitada ou sentada e que não aumentam o dispêndio energético acima dos níveis de repouso, ≤ 1.5 equivalentes metabólicos (METs). Ao analisar as implicações fisiológicas destes comportamentos para a saúde das pessoas é possível destacar a redução e/ou a cessação da contratilidade muscular como desencadeador do processo de diminuição da utilização da glicose pelos músculos, do aumento da insulina e do favorecimento da produção de lipídios que serão preferencialmente armazenados no tecido adiposo da região central do corpo, o qual por sua vez produz moléculas inflamatórias precursoras das doenças crónicas não transmissíveis. A inatividade física e a exposição prolongada a comportamentos sedentários devem ser avaliadas distintamente, respeitando as bases teóricas de cada constructo. O efeito prolongado da exposição aos comportamentos sedentários e da inatividade física ao longo do curso da vida favorece a potencialização dos efeitos nocivos de tais comportamentos na velhice e a mortalidade precoce.Palavras-chaves: atividade física, estilo de vida sedentário, revisão de literatura. ABSTRACTThis present study aimed to: a) review the operational terms of sedentary behaviour characterization, b) describe the health implications, and c) sedentary behaviour main evaluation methods. Sedentary behaviour is the word targeting activities that are performed in lying or sitting position and that do not increase energy expenditure above resting levels, ≤ 1.5 metabolic equivalent units (METs). Through the analysis of the physiological implications of such behaviour to people's health it is possible to highlight the reduction and / or cessation of muscle contractility as a beginner of the reducing process of the use of glucose by muscles, increasing insulin and facilitating the production of lipids that are preferentially stored in the central body adipose tissue, which in turn produces inflammatory molecules which are the precursors of non-transmissible chronic diseases. Physical inactivity and prolonged exposure to sedentary behaviours should be evaluated distinctly, considering the theoretical bases of each construct. The prolonged effect of sedentary behaviours and physical inactivity throughout lifespan enables the possibility of the harmful effects of such behaviours in old age and premature mortality.

In this study, older adults who sat the most presented the worst scores in the physical domain and social participation facet of quality of life.

These findings could be used to help in the development of health policies and in the establishment of adequate programs aimed at reducing the risk of malnutrition in this population.

BackgroundIdentifying correlates of sedentary behavior in older adults is of major importance to healthcare. To our knowledge, there are no population studies in Latin America examining which factors are associated to high sitting time in older adults. Thus, the purpose of this study is to identify socio-demographic, clinical, and health behavior correlates of sitting time in a representative sample of older adults living in Southeastern Brazil.MethodsA cross-sectional study was conducted in twenty-four municipalities of the Triangulo Mineiro region in the State of Minas Gerais, Southeastern Brazil. A structured questionnaire was applied to obtain information on socio-demographic, clinical, and health behavior factors. Overall sitting time was assessed using a self-report instrument. A Multiple Correspondence Analysis was used to verify the association of sitting time with socio-demographic, clinical, and health behavior factors.Results3,296 older adults (61.5% women and 38.5% men) were included in the analysis. The overall median was 240.0 minutes of sitting time/day. The Multiple Correspondence Analysis showed that the group with the highest sitting time presented the following characteristics: women, age greater than 70 years, unschooled status, arterial hypertension, diabetes mellitus, use of medication, poor self-rated health, dependence in basic activities of daily living, and absence of regular physical activity.ConclusionThis study reveals that socio-demographic, clinical, and health behavior factors are associated with high sitting time in older adults from Southeastern Brazil. The results may help to identify older adults that should be targeted in interventions aiming at reducing sitting time.

The present findings contribute to the understanding of nutritional risk, and support the association between quality of life and nutritional status. These factors should be considered in the diagnosis, monitoring and treatment of nutritional disorders, and may contribute to the prevention and reduction of nutritional risk in this especially vulnerable population.