Tsai Wei-Lun, Davis Amy J S, Jackson Laura E
Oak Ridge Institute for Science and Education (ORISE) participant at the Office of Research and Development, U.S. Environmental Protection Agency, Research Triangle Park, NC, USA.
Department of Biology, Ghent University, Ghent, Belgium.
Urban For Urban Green. 2019 May;41:104-107. doi: 10.1016/j.ufug.2019.03.011.
Obesity is a major international health concern. Neighborhood greenery has been identified as a critical factor for promoting health in urban areas, due in part to its apparent role in facilitating healthy weight by promoting physical activity. However, studies have used diverse greenery measures and spatial analysis units to ascertain this relationship. This study examined associations between street greenery and weight status at the residential address level across 500 to 2000m buffers in two climatically distinct communities, Phoenix, AZ, and Portland, OR. Greenery was measured using one-meter landcover data. Street greenery measures were designed to quantify the pedestrian environment along a gradient of suitability for promoting physical exercise. Weight status was defined by body mass index (BMI) calculated from weight and height information on driver's license records. BMI values were dichotomized at 25 into overweight or obese vs. neither. Approximately 500,000 BMI values in Phoenix and 225,000 in Portland were modelled by community using logistic regression. Street tree cover was consistently protective for healthy weight status across all buffer sizes after adjusting for potential confounders. Herbaceous street cover showed protective associations in Phoenix but harmful associations in Portland. Every 10% increase in street tree cover within 2000m was associated with 18% lower odds of being overweight or obese (adjusted odds ratio [AOR]: 0.82, 95% CI: 0.81 - 0.84 in Phoenix; 0.82, 95% CI: 0.81 - 0.83 in Portland). When compared to residents with less than 10% street tree cover within 2000m, those with greater than 10% tree cover had at least 13% (AOR for Portland: 0.87, 95% CI: 0.81 - 0.92) lower odds of being overweight or obese. Findings support the importance of urban street trees in very different climates for facilitating healthy weight status. They can inform greenery management to prioritize vegetation type and allocation decisions in limited urban spaces.
肥胖是一个重大的国际健康问题。社区绿化已被视为促进城市地区健康的关键因素，部分原因在于它在通过促进体育活动来帮助维持健康体重方面所发挥的显著作用。然而，此前的研究采用了多种绿化指标和空间分析单位来确定这种关系。本研究在两个气候差异明显的社区——亚利桑那州的凤凰城和俄勒冈州的波特兰，考察了住宅地址层面街道绿化与体重状况之间在500至2000米缓冲区内的关联。绿化情况通过一米分辨率的土地覆盖数据进行测量。街道绿化指标旨在沿着促进体育锻炼的适宜程度梯度来量化行人环境。体重状况由根据驾照记录上的体重和身高信息计算得出的身体质量指数（BMI）来定义。BMI值在25处进行二分，分为超重或肥胖与非超重或肥胖两类。凤凰城约50万个BMI值以及波特兰约22.5万个BMI值通过社区采用逻辑回归进行建模。在对潜在混杂因素进行调整后，街道树木覆盖率在所有缓冲区内对健康体重状况始终具有保护作用。草本街道覆盖在凤凰城显示出保护关联，但在波特兰则显示出有害关联。在2000米范围内，街道树木覆盖率每增加10%，超重或肥胖的几率就降低18%（调整后的优势比[AOR]：凤凰城为0.82，95%置信区间：0.81 - 0.84；波特兰为0.82，95%置信区间：0.81 - 0.83）。与在2000米范围内街道树木覆盖率低于10%的居民相比，树木覆盖率高于10%的居民超重或肥胖的几率至少低13%（波特兰的AOR为0.87，95%置信区间：0.81 - 0.92）。研究结果支持了城市街道树木在截然不同的气候条件下对于促进健康体重状况的重要性。它们可以为绿化管理提供参考，以便在有限的城市空间中对植被类型和布局决策进行优先排序。
