Abstract

Background:

Air pollution may be associated with elevated dementia risk. Prior research has limitations that may affect reliability, and no studies have evaluated this question in a population-based cohort of men and women in the United States.

Objectives:

We evaluated the association between time-varying, 10-y average fine particulate matter (${\mathrm{PM}}_{2.5}$) exposure and hazard of all-cause dementia. An additional goal was to understand how to adequately control for age and calendar-time-related confounding through choice of the time axis and covariate adjustment.

Methods:

Using the Adult Changes in Thought (ACT) population-based prospective cohort study in Seattle, we linked spatiotemporal model-based ${\mathrm{PM}}_{2.5}$ exposures to participant addresses from 1978 to 2018. Dementia diagnoses were made using high-quality, standardized, consensus-based protocols at biennial follow-ups. We conducted multivariable Cox proportional hazards regression to evaluate the association between time-varying, 10-y average ${\mathrm{PM}}_{2.5}$ exposure and time to event in a model with age as the time axis, stratified by apolipoprotein E (APOE) genotype, and adjusted for sex, education, race, neighborhood median household income, and calendar time. Alternative models used calendar time as the time axis.

Results:

We report 1,136 cases of incident dementia among 4,166 individuals with nonmissing APOE status. Mean [mean ± standard deviation (SD)] 10-y average ${\mathrm{PM}}_{2.5}$ was $10.1\left(\pm 2.9\right){\mathrm{\mu }\mathrm{g}/\mathrm{m}}^3$. Each $1{\text{-}\mathrm{\mu }\mathrm{g}/\mathrm{m}}^3$ increase in the moving average of 10-y ${\mathrm{PM}}_{2.5}$ was associated with a 16% greater hazard of all-cause dementia [1.16 (95% confidence interval: 1.03, 1.31)]. Results using calendar time as the time axis were similar.

Discussion:

In this prospective cohort study with extensive exposure data and consensus-based outcome ascertainment, elevated long-term exposure to ${\mathrm{PM}}_{2.5}$ was associated with increased hazard of all-cause dementia. We found that optimal control of age and time confounding could be achieved through use of either age or calendar time as the time axis in our study. Our results strengthen evidence on the neurodegenerative effects of ${\mathrm{PM}}_{2.5}$. https://doi.org/10.1289/EHP9018

中文翻译：

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细颗粒物和痴呆症发病率在成人思想研究中的变化

摘要

背景：

空气污染可能与痴呆风险增加有关。先前的研究存在可能影响可靠性的局限性，并且没有研究在美国基于人口的男性和女性队列中评估过这个问题。

目标：

我们评估了随时间变化的 10 年平均细颗粒物之间的关联（${\mathrm{下午}}_{2.5}$) 暴露和全因痴呆症的危害。另一个目标是了解如何通过选择时间轴和协变量调整来充分控制与年龄和日历时间相关的混杂。

方法：

使用西雅图成人思想改变 (ACT) 人群为基础的前瞻性队列研究，我们将基于时空模型的${\mathrm{下午}}_{2.5}$从 1978 年到 2018 年接触参与者地址。痴呆症诊断是在两年一次的随访中使用高质量、标准化、基于共识的协议进行的。我们进行了多变量 Cox 比例风险回归，以评估随时间变化的 10 年平均值之间的关联${\mathrm{下午}}_{2.5}$在以年龄为时间轴的模型中暴露和发生事件的时间，按载脂蛋白 E (APOE) 基因型分层，并根据性别、教育、种族、邻里家庭收入中位数和日历时间进行调整。替代模型使用日历时间作为时间轴。

结果：

我们报告了 4,166 名 APOE 状态未缺失的个体中的 1,136 例痴呆症患者。平均值 [平均值±标准偏差 (SD)] 10 年平均值${\mathrm{下午}}_{2.5}$曾是$10.1\left(\pm 2.9\right){\mathrm{\mu }\mathrm{G}/\mathrm{米}}^{\mathrm{3个}}$. 每个$\mathrm{1个}{\text{-}\mathrm{\mu }\mathrm{G}/\mathrm{米}}^{\mathrm{3个}}$10 年移动平均线增加${\mathrm{下午}}_{2.5}$与全因痴呆症的风险增加 16% [1.16（95% 置信区间：1.03，1.31）] 相关。使用日历时间作为时间轴的结果是相似的。

讨论：

在这项具有大量接触数据和基于共识的结果确定的前瞻性队列研究中，长期接触${\mathrm{下午}}_{2.5}$与全因痴呆症的风险增加有关。我们发现，在我们的研究中，可以通过使用年龄或日历时间作为时间轴来实现对年龄和时间混杂的最佳控制。我们的结果加强了神经退行性影响的证据${\mathrm{下午}}_{2.5}$. https://doi.org/10.1289/EHP9018