دانلود رایگان مقاله انگلیسی مفاهیم فضای سبز موثر در روابط فضای سبز با اضافه وزنی و فعالیت فیزیکی - الزویر 2018

ABSTRACT

Introduction: In epidemiological studies, exposure to green space is inconsistently associated with being overweight and physical activity, possibly because studies differ widely in their definition of green space exposure, inclusion of important confounders, study population and data analysis. Objectives: We evaluated whether the association of green space with being overweight and physical activity depended upon definition of greenspace. Methods: We conducted a cross-sectional study using data from a Dutch national health survey of 387,195 adults. Distance to the nearest park entrance and surrounding green space, based on the Normalized Difference Vegetation Index (NDVI) or a detailed Dutch land-use database (TOP10NL), was calculated for each residential address. We used logistic regression analyses to study the association of green space exposure with being overweight and being moderately or vigorously physically active outdoors at least 150 min/week (self-reported). To study the shape of the association, we specified natural splines and quintiles. Results: The distance to the nearest park entrance was not associated with being overweight or outdoor physical activity. Associations of surrounding green space with being overweight or outdoor physical activity were highly non-linear. For NDVI surrounding greenness, we observed significantly decreased odds of being overweight [300 m buffer, odds ratio (OR) = 0.88; 95% CI: 0.86, 0.91] and increased odds for outdoor physical activity [300 m buffer, OR = 1.14; 95% CI: 1.10, 1.17] in the highest quintile compared to the lowest quintile. For TOP10NL surrounding green space, associations were mostly non-significant. Associations were generally stronger for subjects living in less urban areas and for the smaller buffers. Conclusion: Associations of green space with being overweight and outdoor physical activity differed considerably between different green space definitions. Associations were strongest for NDVI surrounding greenness.

5. Conclusion

This study demonstrated that associations of green space with being overweight and outdoor physical activity differ considerably between different green space definitions. Associations were strongest for NDVI surrounding greenness and for the smallest buffers. We found no indications that distance to park is associated with being overweight or outdoor physical activity. Exposure-response relationships showed that the magnitude of the potential benefits of surrounding green depend on the level of surrounding green. Therefore, we recommend more research to evaluate optimum levels of green space. Moreover, our study suggests that the inconsistency of associations of green space with being overweight and physical activity in previous studies may partly be due to non-linearity of the associations, subgroups and adjustment for confounders.