<p>Effect of ambient air quality on exacerbation of COPD in patients and its potential mechanism</p>

Abstract

Background Chronic obstructive pulmonary disease (COPD) is a disease of continuous progress and environmental factors may affect the progress. COPD patients’ activity tolerance and quality of life are associated with air quality. COPD exacerbation from the perspective of geographical air quality has not been reported. Objectives To explore environmental effect of two different geographical places on COPD exacerbation and the effect of cigarette smoke extract and carbon particles on bronchial epithelial cell viability. Methods Total 139 COPD patients, who lived in Beijing during summer and temporarily migrated to Sanya city in winter, have been enrolled. Respiratory symptoms and lung function data were collected when they were living in Beijing or Sanya, respectively. Effect of cigarette smoke extract plus ultrafine carbon particles on airway epithelial cells were studied. Measurements and main results Air pollution as measured by air quality index (AQI) in Beijing summer (113.1±14.2) was significantly worse than that in Sanya winter (49.4±8.9, p <0.001). The COPD Assessment Test (CAT) score was significantly higher in Beijing (26.4±7.1) than that in Sanya (20.0±8.0, p =0.019). Modified Medical Research Council dyspnea scale was also significantly higher in Beijing (2.9±0.9) than that in Sanya (1.9±0.8, p <0.001). FEV 1 was significantly improved when the patients were in Sanya (48.88±24.78%) compared to that in Beijing (41.79±20.06%, p <0.01). Compared with Beijing and Sanya, the relative risk (RR) of hospitalization and acute exacerbation were 1.64 and 3.36, respectively. In vitro study demonstrated that apoptosis of BEAS2B cells in response to cigarette smoke extract plus ultrafine carbon particles (25.50±2.10%) was significantly higher than that of control culture (2.30±1.05%, p <0.01). Conclusion These findings suggested that ambient air pollution cause COPD exacerbation, and that air pollutants particle matters induce apoptosis of airway epithelial cells.

<p>Lifetime Occupational History, Respiratory Symptoms and Chronic Obstructive Pulmonary Disease: Results from a Population-Based Study</p>

“…Outdoor air pollution in studies elsewhere consistently showed greater likelihood of respiratory symptoms in both children and adults [24][25][26][27] and COPD. [8][9][10] We hypothesize, that the basic air pollution level in Almaty is so high, that a distance of 50 to 100 meters from a major road cannot play a role in worsening the symptoms. Despite known very high levels of air pollution in Almaty, including particulate matter, especially in winter, no scientific analysis of air pollution levels has been published to date.…”

“…Finally, ambient air pollution is often not regarded as an important confounder in the occupational studies, despite growing evidence that it is independently associated with greater risk of COPD. [8][9][10] Therefore, the aim of the current analysis was to ascertain the effect of lifelong occupational history, ambient air pollution, and biochemically verified smoking status with COPD in general population of one the largest cities in Central Asia, Almaty.…”

Air Pollution Exposure as a Relevant Risk Factor for Chronic Obstructive Pulmonary Disease Exacerbations in Male and Female Patients

“…It was found that the poorer air quality index and higher temperatures in Beijing were associated with a lower forced expiratory volume in 1 second, higher dyspnoea, and a relative risk of exacerbations that was twice as high as that observed in patients in Sanya. 31 The authors also reported that ambient air pollution was strongly associated with COPD exacerbations by triggering apoptosis in airway epithelial cells. 31 Although adequate evidence for a direct relationship between ambient air pollution components and the development of COPD is lacking, higher mortality rates from respiratory and cardiovascular diseases have been reported among patients who have been exposed to air pollution for a long time.…”

“…29 Some studies suggest that temperature may modify the effect of air pollution exposure, although these results are not conclusive. 30 For example, Yan et al 31 explored the environmental effect of two different geographical locations in China on COPD exacerbations (Beijing in the summer; Sanya in the winter). It was found that the poorer air quality index and higher temperatures in Beijing were associated with a lower forced expiratory volume in 1 second, higher dyspnoea, and a relative risk of exacerbations that was twice as high as that observed in patients in Sanya.…”

Air Pollution Exposure as a Relevant Risk Factor for COPD Exacerbations in Male and Female Patients

“…Some studies suggest that temperature may modify the effect of air pollution exposure, although their results are not conclusive [37]. For example, Yan et al explored the environmental effect of two different geographical places on COPD exacerbations (Beijing in summer, Sanya in winter) and found that poorer air quality index (AQI) and higher temperatures in Beijing were associated with lower FEV1, higher dyspnea, and a twice higher relative risk of exacerbations than in patients in Sanya [38]. The authors also reported that ambient air pollution was strongly associated with COPD exacerbations by triggering apoptosis in airway epithelial cells [38].…”