Physical activity, sedentary behavior and functionality in older adults: A cross-sectional path analysis

Disability is negatively associated with the health of older adults, and it can be mediated by healthy lifestyles and behaviors throughout one's life. In this context, understanding the interrelationships between sedentary behavior, physical activity and functionality may assist in the implementation of effective public health actions. Thus, the aim of the present study was to investigate the relationships between both physical activity and sedentary behavior and functionality in older adults and the possible mediators. The variables analyzed were selected according to the content analysis of International Classification of Functioning, Disability and Health model, and included activity, participation, health conditions, body functions and structures, environmental factors and personal factors. 419 individuals participated in the study. Physical activity was directly associated with disability in instrumental activities of daily living (IADL), and the association was mediated by self-esteem, aerobic endurance, and agility/balance. Sedentary behavior was indirectly associated with IADL disability, and the association was mediated by aerobic resistance, nutritional status, and agility/balance. Regarding the basic activities of daily living (BADL), physical activity showed an indirect association mediated by aerobic resistance and IADL. The association of sedentary behavior with BADL was mediated by aerobic resistance and lower limb flexibility. These results reinforce the idea that functionality is multidimensional, and the mediating factors must be considered when strategies for promoting physical activity and reducing sedentary behavior are designed.

Prevalência de sintomatologia depressiva em idosos brasileiros: uma revisão sistemática com metanálise

RESUMO Objetivo Estimar a prevalência de sintomatologia depressiva em idosos brasileiros residentes na comunidade. Métodos Foi realizada uma revisão sistemática nas bases de dados Medline, SciELO, Web of Science, Scopus e CINAHL, sendo selecionados estudos com idosos brasileiros que identificaram a prevalência de sintomatologia depressiva. De forma independente, dois pesquisadores selecionaram os estudos, extraíram os dados e avaliaram a qualidade metodológica. A metanálise foi realizada para estimar a prevalência de sintomatologia depressiva usando um modelo de efeito aleatório. Resultados Foram identificados 176 artigos e 33 foram incluídos na revisão, que investigaram 34 prevalências, com um total de 39.431 idosos. A distribuição geográfica dos estudos indicou pesquisas em todas as regiões do Brasil. A versão curta da Escala de Depressão Geriátrica foi a mais utilizada. A prevalência estimada de sintomatologia depressiva foi de 21,0% (IC de 95%: 18,0-25,0; I2 = 98,3%). As análises de subgrupos revelaram elevada heterogeneidade em todas as categorias analisadas. A metarregressão não identificou as causas da heterogeneidade. Conclusão Apesar da heterogeneidade entre os estudos analisados, os resultados indicam a necessidade de estratégias de intervenção para reduzir a prevalência de sintomatologia depressiva.

Isotemporal substitution analysis of time between sleep, sedentary behavior, and physical activity on depressive symptoms in older adults: a cross-sectional study

BACKGROUND

Compared to young individuals, older adults participate more in sedentary behavior (SB) and less in physical activity (PA). These behaviors are associated with numerous adverse health factors.

OBJECTIVE

The purpose of the study was to examine the hypothetical effects of substituting time spent sleeping, performing SB, and performing moderate-to-vigorous physical activity (MVPA) on depressive symptomatology in older adults.

DESIGN AND SETTING

An analytical cross-sectional study employing exploratory survey methods was conducted in the city of Alcobaça in the state of Bahia, Brazil.

METHODS

The study included 473 older adults who answered a structured questionnaire during an interview. Exposure time to SB and PA level were assessed using the International Physical Activity Questionnaire, and depressive symptoms were analyzed using the short version of the Geriatric Depression Scale. An isotemporal replacement model was used to evaluate the effects of different SB sessions on depressive symptomatology.

RESULTS

An increase in the risk of depressive symptoms was observed when MVPA and sleep time were substituted for the same SB time at all times tested, with maximum values of 40% and 20%, respectively. Opposite substitution of MVPA and sleep time increments reduced the risk of depressive symptomatology by 28% and 17%, respectively.

CONCLUSIONS

The results of the present study indicate that replacing SB with the same amount of sleep or MVPA may reduce depressive symptoms. The longer the reallocation time, the greater are the benefits.