University of Southern California, Los Angeles, CA, USA.
Wake Forest School of Medicine, Winston-Salem, NC, USA.
Environ Pollut. 2021 Feb 15;271:116282. doi: 10.1016/j.envpol.2020.116282. Epub 2020 Dec 14.
The interrelationships among long-term ambient air pollution exposure, emotional distress and cognitive decline in older adulthood remain unclear. Long-term exposure may impact cognitive performance and subsequently impact emotional health. Conversely, exposure may initially be associated with emotional distress followed by declines in cognitive performance. Here we tested the inter-relationship between global cognitive ability, emotional distress, and exposure to PM (particulate matter with aerodynamic diameter <2.5 μm) and NO (nitrogen dioxide) in 6118 older women (aged 70.6 ± 3.8 years) from the Women's Health Initiative Memory Study. Annual exposure to PM (interquartile range [IQR] = 3.37 μg/m) and NO (IQR = 9.00 ppb) was estimated at the participant's residence using regionalized national universal kriging models and averaged over the 3-year period before the baseline assessment. Using structural equation mediation models, a latent factor capturing emotional distress was constructed using item-level data from the 6-item Center for Epidemiological Studies Depression Scale and the Short Form Health Survey Emotional Well-Being scale at baseline and one-year follow-up. Trajectories of global cognitive performance, assessed by the Modified-Mini Mental State Examination (3MS) annually up to 12 years, were estimated. All effects reported were adjusted for important confounders. Increases in PM (β = -0.144 per IQR; 95% CI = -0.261; -0.028) and NO (β = -0.157 per IQR; 95% CI = -0.291; -0.022) were associated with lower initial 3MS performance. Lower 3MS performance was associated with increased emotional distress (β = -0.008; 95% CI = -0.015; -0.002) over the subsequent year. Significant indirect effect of both exposures on increases in emotional distress mediated by exposure effects on worse global cognitive performance were present. No statistically significant indirect associations were found between exposures and 3MS trajectories putatively mediated by baseline emotional distress. Our study findings support cognitive aging processes as a mediator of the association between PM and NO exposure and emotional distress in later-life.
长期暴露于环境空气污染、情绪困扰与老年人认知能力下降之间的相互关系仍不明确。长期暴露可能会影响认知表现，进而影响情绪健康。相反，暴露可能最初与情绪困扰相关，随后认知表现下降。在这里，我们在 Women's Health Initiative Memory Study 中测试了 6118 名年龄在 70.6±3.8 岁的老年女性（参与者）的整体认知能力、情绪困扰与 PM（空气动力学直径<2.5μm 的颗粒物）和 NO（二氧化氮）暴露之间的关系。使用区域化国家通用克立格模型，在参与者居住的地方估算每年的 PM（四分位距 [IQR] = 3.37μg/m）和 NO（IQR = 9.00ppb）暴露量，并在基线评估前的 3 年期间取平均值。使用结构方程中介模型，使用基线和一年随访时的 6 项中心流行病学研究抑郁量表和简明健康调查问卷情感健康量表的项目级数据构建了一个捕捉情绪困扰的潜在因素。使用每年评估一次的改良 Mini-Mental State Examination（3MS）来估计整体认知表现的轨迹，直至 12 年。报告的所有影响都经过重要混杂因素的调整。PM（每 IQR 增加 0.144；95%CI=-0.261；-0.028）和 NO（每 IQR 增加 0.157；95%CI=-0.291；-0.022）的增加与初始 3MS 表现较低有关。较低的 3MS 表现与随后一年情绪困扰的增加有关（β=-0.008；95%CI=-0.015；-0.002）。两种暴露物对情绪困扰增加的影响通过暴露物对整体认知表现恶化的影响存在显著的间接效应。在假定由基线情绪困扰介导的暴露与 3MS 轨迹之间没有发现统计学上显著的间接关联。我们的研究结果支持认知老化过程作为 PM 和 NO 暴露与晚年情绪困扰之间关联的中介。
