Áreas verdes, prática de atividade física e fatores de risco cardiometabólicos: Estudo Longitudinal de Saúde do Adulto (ELSA-Brasil)

Abstract

Evidence points out that neighborhood greenspaces contribute to the improvement of cardiometabolic health. Greenspaces can stimulate social cohesion and physical activity, reduce temperature and promote thermal comfort, in addition to reducing noise and air pollution and thus contribute to better physical and mental health. However, the evidence produced comes mostly from cross-sectional studies run in high-income countries in the northern hemisphere, where there is a greater presence of neighborhood greenspaces than in low- and middle-income countries. The objective of this thesis was to investigate the association between the amount of neighborhood greenspaces and cardiometabolic risk factors and leisure-time physical activity trajectories in up to eight years of follow-up in adults living in Brazilian capitals. In the first article, data from participants residing in the city of Belo Horizonte who attended visits 1 (2008-2010) and 2 (2012-2014) were used. Logistic regression models with generalized estimating equations (GEE) were used to investigate whether, over 3.7 years of follow-up, the prevalence and incidence of cardiometabolic risk factors ((i) obesity, (ii) abdominal obesity, and (iii) low HDL-c would be lower among individuals who lived in neighborhoods with higher greenspace, identified by the distribution of the average Normalized Difference Vegetation Index (NDVI) and by the percentages of tree and herbaceous cover in public areas, defined as 500 meters circular buffer around the residence. Cross-sectional analyzes indicated that the higher greenspace, measured by the NDVI, was associated with lower odds of obesity and abdominal obesity, regardless of individual sociodemographic characteristics and neighborhood socioeconomic status. A borderline association was also found between the higher greenspace and the lower odds of low HDL-c. The magnitude of the association was greater between higher percentages of tree cover and lower odds of obesity, abdominal obesity and low HDL-c. Higher percentages of herbaceous cover were associated only with lower odds of abdominal obesity. Longitudinal associations between greenspace indicators and the incidence of cardiometabolic risk factors were not statistically significant in the evaluated follow-up period. In the second article, data from participants residing in Belo Horizonte and São Paulo who attended visit 1, visit 2 (2012-2014) and visit 3 (2017-2019) were used. Multinomial logistic regression models were used to investigate whether exposure to neighborhood greenspace, measured by the average NDVI in a 500 meters circular buffer around the residence, would be associated with the trajectory of moderate/vigorous physical activity, defined by the number of visits in which the participant practiced moderate/vigorous activity: a) none; b) 1 or 2 visits; c) 3 visits. It was also investigated whether this association would be independent of the perceived safety in the neighborhood, the presence of sidewalks and public lighting and the neighborhood socioeconomic status. After adjusting for individual covariables, compared to participants residing in areas with lower greenspace, those residing in higher greenspace were more likely to practice physical activity in 3 visits, compared to those who did not practice physical activity in any visit. These associations were maintained in separate models with adjustment for perceived safety in the neighborhood, the presence of sidewalks and public lighting. However, the association between the trajectory of practice of moderate/vigorous physical activity was not independent of the neighborhood socioeconomic status. The results suggest that urban planning actions should improve the access and distribution of environmental factors, especially greenspaces, in order to encourage the practice of leisure-time physical activity and improve cardiometabolic health.