Aging Research Center, Department of Neurobiology, Care Sciences and Society, Karolinska Institutet and Stockholm University, Stockholm, Sweden.
Institute of Environmental Medicine (IMM), Karolinska Institutet, Stockholm, Sweden.
J Alzheimers Dis. 2021;80(2):591-599. doi: 10.3233/JAD-200852.
A growing but contrasting evidence relates air pollution to cognitive decline. The role of cerebrovascular diseases in amplifying this risk is unclear.
We examined 2,253 participants of the Swedish National study on Aging and Care in Kungsholmen (SNAC-K). One major air pollutant (particulate matter ≤2.5μm, PM2.5) was assessed yearly from 1990, using dispersion models for outdoor levels at residential addresses. The speed of cognitive decline (Mini-Mental State Examination, MMSE) was estimated as the rate of MMSE decline (linear mixed models) and further dichotomized into the upper (25%fastest cognitive decline), versus the three lower quartiles. The cognitive scores were used to calculate the odds of fast cognitive decline per levels of PM2.5 using regression models and considering linear and restricted cubic splines of 10 years exposure before the baseline. The potential modifier effect of cerebrovascular diseases was tested by adding an interaction term in the model.
We observed an inverted U-shape relationship between PM2.5 and cognitive decline. The multi-adjusted piecewise regression model showed an increased OR of fast cognitive decline of 81%(95%CI = 1.2-3.2) per interquartile range difference up to mean PM2.5 level (8.6μg/m3) for individuals older than 80. Above such level we observed no further risk increase (OR = 0.89;95%CI = 0.74-1.06). The presence of cerebrovascular diseases further increased such risk by 6%.
Low to mean PM2.5 levels were associated with higher risk of accelerated cognitive decline. Cerebrovascular diseases further amplified such risk.
越来越多的证据表明，空气污染与认知能力下降有关。但脑血管疾病在放大这一风险中的作用尚不清楚。
1）研究长期暴露于空气污染与认知能力下降之间的关系；2）检验脑血管疾病是否会放大这种关联。
我们研究了来自瑞典 Kungsholmen 老龄化和护理全国研究（SNAC-K）的 2253 名参与者。每年使用分散模型评估一次主要空气污染物（颗粒物≤2.5μm，PM2.5），评估地点为居住地址的室外水平。认知能力下降的速度（简易精神状态检查，MMSE）通过 MMSE 下降的速度（线性混合模型）进行估计，并进一步分为上四分位数（最快认知下降的 25%）和三个较低的四分位数。使用回归模型，根据 10 年的暴露水平，考虑 PM2.5 水平与认知评分的线性和限制三次样条关系，计算每个 PM2.5 水平的快速认知下降的几率。通过在模型中添加交互项来测试脑血管疾病的潜在修饰效应。
我们观察到 PM2.5 与认知能力下降之间呈倒 U 型关系。多因素调整的分段回归模型显示，对于年龄大于 80 岁的个体，每增加一个四分位距差异，快速认知下降的比值比（OR）增加 81%（95%CI：1.2-3.2），达到平均 PM2.5 水平（8.6μg/m3）。在这一水平以上，我们没有观察到进一步的风险增加（OR=0.89；95%CI：0.74-1.06）。脑血管疾病的存在进一步增加了这种风险 6%。
低至中等水平的 PM2.5 与加速认知能力下降的风险增加有关。脑血管疾病进一步放大了这种风险。
