Human and Evolutionary Biology Section, Department of Biological Sciences, University of Southern California, CA.
Department of Community, Environment, and Policy, Mel and Enid Zuckerman College of Public Health, University of Arizona, Tucson, AZ.
Med Sci Sports Exerc. 2022 Jul 1;54(7):1131-1138. doi: 10.1249/MSS.0000000000002888. Epub 2022 Feb 8.
Physical activity (PA) is recognized as one of the key lifestyle behaviors that reduces risk of developing dementia late in life. However, PA also leads to increased respiration, and in areas with high levels of air pollution, PA may increase exposure to pollutants linked with higher risk of developing dementia. Here, we investigate whether air pollution attenuates the association between PA and dementia risk.
This prospective cohort study included 35,562 adults 60 yrs and older from the UK Biobank. Average acceleration magnitude (ACCave) from wrist-worn accelerometers was used to assess PA levels. Air pollution levels (NO, NO2, PM10, PM2.5, PM2.5-10, and PM2.5 absorbance) were estimated with land use regression methods. Incident all-cause dementia was derived from inpatient hospital records and death registry data.
In adjusted models, ACCave was associated with reduced risk of developing dementia (HR = 0.71, 95% confidence interval [CI] = 0.60-0.83), whereas air pollution variables were not associated with dementia risk. There were significant interactions between ACCave and PM2.5 (HRinteraction = 1.33, 95% CI = 1.13-1.57) and PM2.5 absorbance (HRinteraction = 1.24, 95% CI = 1.07-1.45) on incident dementia. At the lowest tertiles of pollution, ACCave was associated with reduced risk of incident dementia (HRPM 2.5 = 0.66, 95% CI = 0.49-0.91; HRPM 2.5 absorbance = 0.60, 95% CI = 0.44-0.81). At the highest tertiles of these pollutants, there was no significant association of ACCave with incident dementia (HRPM 2.5 = 0.88, 95% CI = 0.68-1.14; HRPM 2.5 absorbance = 0.79, 95% CI = 0.60-1.04).
PA is associated with reduced risk of developing all-cause dementia. However, exposure to even moderate levels of air pollution attenuates the benefits of PA on risk of dementia.
身体活动（PA）被认为是降低晚年患痴呆风险的关键生活方式行为之一。然而，PA 也会导致呼吸增加，而在空气污染水平较高的地区，PA 可能会增加接触与更高痴呆风险相关的污染物。在这里，我们研究了空气污染是否会减弱 PA 与痴呆风险之间的关联。
这项前瞻性队列研究包括来自英国生物银行的 35562 名 60 岁及以上的成年人。使用腕戴加速度计的平均加速度幅度（ACCave）来评估 PA 水平。使用土地利用回归方法估计空气污染水平（NO、NO2、PM10、PM2.5、PM2.5-10 和 PM2.5 吸光度）。从住院患者记录和死亡登记数据中获得全因痴呆的发病情况。
在调整后的模型中，ACCave 与降低痴呆发病风险相关（HR=0.71，95%置信区间[CI]：0.60-0.83），而空气污染变量与痴呆风险无关。ACCave 与 PM2.5（HRinteraction=1.33，95%CI：1.13-1.57）和 PM2.5 吸光度（HRinteraction=1.24，95%CI：1.07-1.45）之间存在显著的交互作用。在污染程度最低的 tertiles 中，ACCave 与降低痴呆发病风险相关（HRPM2.5=0.66，95%CI：0.49-0.91；HRPM2.5 吸光度=0.60，95%CI：0.44-0.81）。在这些污染物的最高 tertiles 中，ACCave 与痴呆发病风险无显著关联（HRPM2.5=0.88，95%CI：0.68-1.14；HRPM2.5 吸光度=0.79，95%CI：0.60-1.04）。
PA 与降低全因痴呆的发病风险相关。然而，即使是接触中等水平的空气污染也会减弱 PA 对痴呆风险的益处。
