Egorov Andrey I, Griffin Shannon M, Converse Reagan R, Styles Jennifer N, Sams Elizabeth A, Wilson Anthony, Jackson Laura E, Wade Timothy J
National Health and Environmental Effects Research Laboratory, United States Environmental Protection Agency, Research Triangle Park, NC, USA.
National Exposure Research Laboratory, United States Environmental Protection Agency, Cincinnati, OH, USA.
Environ Res. 2017 Oct;158:508-521. doi: 10.1016/j.envres.2017.07.009. Epub 2017 Jul 11.
Greater exposure to urban green spaces has been linked to reduced risks of depression, cardiovascular disease, diabetes and premature death. Alleviation of chronic stress is a hypothesized pathway to improved health. Previous studies linked chronic stress with a biomarker-based composite measure of physiological dysregulation known as allostatic load.
This study's objective was to assess the relationship between vegetated land cover near residences and allostatic load.
This cross-sectional population-based study involved 206 adult residents of the Durham-Chapel Hill, North Carolina metropolitan area. Exposure was quantified using high-resolution metrics of trees and herbaceous vegetation within 500m of each residence derived from the U.S. Environmental Protection Agency's EnviroAtlas land cover dataset. Eighteen biomarkers of immune, neuroendocrine, and metabolic functions were measured in serum or saliva samples. Allostatic load was defined as a sum of potentially unhealthy biomarker values dichotomized at 10th or 90th percentile of sample distribution. Regression analysis was conducted using generalized additive models with two-dimensional spline smoothing function of geographic coordinates, weighted measures of vegetated land cover allowing decay of effects with distance, and geographic and demographic covariates.
An inter-quartile range increase in distance-weighted vegetated land cover was associated with 37% (95% Confidence Limits 46%; 27%) reduced allostatic load; significantly reduced adjusted odds of having low level of norepinephrine, dopamine, and dehydroepiandrosterone, and high level of epinephrine, fibrinogen, vascular cell adhesion molecule-1, and interleukin-8 in serum, and α-amylase in saliva; and reduced odds of previously diagnosed depression.
The observed effects of vegetated land cover on allostatic load and individual biomarkers are consistent with prevention of depression, cardiovascular disease and premature mortality.
更多地接触城市绿地与降低患抑郁症、心血管疾病、糖尿病和过早死亡的风险有关。缓解慢性压力是一条改善健康状况的假设途径。先前的研究将慢性压力与一种基于生物标志物的生理失调综合指标（称为应激负荷）联系起来。
本研究的目的是评估住宅附近植被覆盖与应激负荷之间的关系。
这项基于人群的横断面研究涉及北卡罗来纳州达勒姆 - 教堂山都会区的206名成年居民。利用美国环境保护局环境地图集土地覆盖数据集得出的每个住宅500米范围内树木和草本植被的高分辨率指标对暴露情况进行量化。在血清或唾液样本中测量了18种免疫、神经内分泌和代谢功能的生物标志物。应激负荷定义为在样本分布的第10或第90百分位数处二分的潜在不健康生物标志物值的总和。使用广义相加模型进行回归分析，该模型具有地理坐标的二维样条平滑函数、允许效应随距离衰减的植被覆盖加权测量以及地理和人口统计学协变量。
距离加权植被覆盖的四分位间距增加与应激负荷降低37%（95%置信区间46%；27%）相关；血清中去甲肾上腺素、多巴胺和脱氢表雄酮水平低以及肾上腺素、纤维蛋白原、血管细胞粘附分子 -1和白细胞介素 -8水平高以及唾液中α -淀粉酶水平高的校正比值显著降低；以及先前诊断为抑郁症的几率降低。
观察到的植被覆盖对应激负荷和个体生物标志物的影响与预防抑郁症、心血管疾病和过早死亡一致。
