Economic and Social Research Institute, Whitaker Square, Sir John Rogerson's Quay, Dublin 2, Ireland.
Department of Economics, Trinity College Dublin, Dublin, Ireland.
BMC Public Health. 2020 May 24;20(1):760. doi: 10.1186/s12889-020-08853-9.
While exposure to urban green spaces has been associated with various physical health benefits, the evidence linking these spaces to lower BMI, particularly among older people, is mixed. We ask whether footpath availability, generally unobserved in the existing literature, may mediate exposure to urban green space and help explain this volatility in results. The aim of this study is to add to the literature on the association between urban green space and BMI by considering alternative measures of urban green space that incorporate measures of footpath availability.
We conduct a cross-sectional study combining data from The Irish Longitudinal Study on Ageing and detailed land use information. We proxy respondents' exposure to urban green spaces at their residential addresses using street-side and area buffers that take account of the presence of footpaths. Generalised linear models are used to test the association between exposure to several measures of urban green space and BMI.
Relative to the third quintile, exposure to the lowest quintile of urban green space, as measured within a 1600 m footpath-accessible network buffer, is associated with slightly higher BMI (marginal effect: 0.80; 95% CI: 0.16-1.44). The results, however, are not robust to small changes in how green space is measured and no statistically significant association between urban green spaces and BMI is found under other variants of our regression model.
The relationship between urban green spaces and BMI among older adults is highly sensitive to the characterisation of local green space. Our results suggest that there are some unobserved factors other than footpath availability that mediate the relationship between urban green spaces and weight status.
虽然暴露于城市绿地与各种身体健康益处有关，但这些空间与 BMI 降低之间的关联证据，尤其是在老年人中，是混杂的。我们想知道，在现有文献中通常无法观察到的步道可用性，是否可以调节城市绿地的暴露，并帮助解释这些结果的波动性。本研究旨在通过考虑纳入步道可用性衡量标准的城市绿地替代衡量标准，为城市绿地与 BMI 之间的关联研究增添新的内容。
我们进行了一项横断面研究，结合了爱尔兰老龄化纵向研究的数据和详细的土地利用信息。我们使用考虑步道存在情况的街边和区域缓冲区，以受访者的居住地址为代理，来衡量他们对城市绿地的暴露程度。我们使用广义线性模型来检验几种城市绿地衡量标准与 BMI 之间的关联。
与第三五分位数相比，在 1600 米可步行网络缓冲区中，处于城市绿地最低五分位数的暴露程度与稍高的 BMI 相关（边际效应：0.80；95%置信区间：0.16-1.44）。然而，这些结果对绿地衡量标准的微小变化并不稳健，并且在我们回归模型的其他变体下，城市绿地与 BMI 之间没有发现统计学上显著的关联。
老年人中城市绿地与 BMI 之间的关系对当地绿地的特征高度敏感。我们的结果表明，除了步道可用性之外，还有一些未被观察到的因素在调节城市绿地与体重状况之间的关系。
