Chen Kelly, Aglan Mostafa, Purcell Alexandra, Nurhussien Lina, Koutrakis Petros, Coull Brent A, Synn Andrew, Rice Mary B
Division of Pulmonary, Critical Care and Sleep Medicine, Department of Medicine, Beth Israel Deaconess Medical Center, Boston, Massachusetts, United States.
Harvard College, Harvard University, Cambridge, Massachusetts, United States.
Chronic Obstr Pulm Dis. 2023 Apr 27;10(2):170-177. doi: 10.15326/jcopdf.2022.0385.
Although physical activity is strongly encouraged for patients with chronic obstructive pulmonary disease (COPD), it is unknown if physical activity affects daily exposure to air pollution, or whether it attenuates or exacerbates the effects of pollution on the airways among adults with COPD.
Thirty former smokers with moderate-to-severe COPD in Boston were followed for 4 non-consecutive months in different seasons. We assessed daily lung function (forced expiratory volume in 1 second [FEV] and forced vital capacity [FVC]), prior-day personal pollutant exposure measured by portable air quality monitors (fine particulate matter [PM] nitrogen oxide [NO], and ozone [O]), and daily step count. We constructed multi-level linear mixed-effects models with random intercepts for person and person-observation month, adjusting for demographic/seasonal covariates to test if step count was associated with daily pollution exposure, and if associations between prior-day pollution and lung function differed based on prior-day step count. Where effect modification was found, we performed stratified analyses by tertile of step count.
Higher daily step count was associated with higher same-day personal exposure to PM, and O but not NO. Each interquartile range (IQR) increment in step count was associated with 0.97 µg/m (95%CI: 0.30, 1.64) higher exposure to PM and 0.15 parts per billion (95% CI: -0.05, 0.35) higher exposure to O in adjusted models. We observed an interaction between prior-day NO and step count on FEV and FVC (P<0.05) in which the negative associations between NO and lung function were reduced or absent at higher levels of daily activity. For example, FEV was 28.5mL (95%CI: -41.0, -15.9) lower per IQR of NO in the lowest tertile of step count, but there was no association in the highest tertile of step count (-1.6mL, 95% CI: -18.4, 15.2).
Higher physical activity was associated with modestly higher daily exposure to PM and O and may attenuate the association between NO exposure and lung function.
尽管强烈鼓励慢性阻塞性肺疾病（COPD）患者进行体育活动，但尚不清楚体育活动是否会影响日常空气污染暴露，或者它是否会减轻或加剧空气污染对COPD成年患者气道的影响。
对波士顿30名患有中度至重度COPD的 former smokers 进行了为期4个月的随访，这4个月分布在不同季节且不连续。我们评估了每日肺功能（一秒用力呼气量[FEV]和用力肺活量[FVC]）、前一天通过便携式空气质量监测仪测量的个人污染物暴露（细颗粒物[PM]、氮氧化物[NO]和臭氧[O]）以及每日步数。我们构建了具有个体和个体观察月份随机截距的多级线性混合效应模型，对人口统计学/季节协变量进行调整，以测试步数是否与每日污染暴露相关，以及前一天污染与肺功能之间的关联是否因前一天的步数而有所不同。当发现效应修正时，我们按步数三分位数进行分层分析。
每日步数增加与当日个人对PM和O的暴露增加相关，但与NO无关。在调整模型中，步数每增加一个四分位数间距（IQR），与PM暴露增加0.97µg/m³（95%CI：0.30，1.64）和O暴露增加十亿分之0.15（95%CI：-0.05，0.35）相关。我们观察到前一天的NO与步数对FEV和FVC存在交互作用（P<0.05），其中在较高的日常活动水平下，NO与肺功能之间的负相关减弱或不存在。例如，在步数最低三分位数中，NO每增加一个IQR，FEV降低28.5mL（95%CI：-41.0，-15.9），但在步数最高三分位数中无关联（-1.6mL，95%CI：-18.4，15.2）。
较高的体育活动与每日对PM和O的暴露适度增加相关，并且可能减弱NO暴露与肺功能之间的关联。
