Association between the Ratio of FEV1 to FVC and the Exposure Level to Air Pollution in Neversmoking Adult Refractory Asthmatics Using Data Clustered by Patient in the Soonchunhyang Asthma Cohort Database

Abstract

Using real-world cases, asthma-related clinical data were clustered by patient; 5% of all asthmatics were found to have refractory asthma (RA) with a relatively low lung function (forced expiratory volume in 1 s/forced vital capacity (FEV1/FVC) less than 80%). Using a multilevel study design for clustered spirometry data observed between 2005 and 2014, we evaluated the association between changes in the ratio of FEV1 to FVC and variations in acute exposure to air pollution. We analyzed 2310 episodes of RA from 214 neversmoking patients. In spring, a 1 µg/m³ increase in concentration of particles ≤10 μm (PM10) on Lag 1 significantly reduced the ratio by 0.4% (95% confidence interval (CI): 0.1–0.7%) after adjusting for sex, age, body mass index (BMI), and total Immunoglobulin E (IgE) level. Unit (ppb) increase in SO2 concentration on Lag 3 and 4 in fall and on Lag 6 in winter significantly reduced the ratio by 2 to 3% (p < 0.05). We found that acute exposure to PM10 in spring or SO2 in fall or winter were positively associated with lung function drop indicating necessity of control strategies of target air pollutant source by season to protect susceptible population.

Impact of Air Pollution on Asthma Outcomes

“…PM exposure might be an important risk factor for lung function deterioration in both children and adults with asthma. An association between the fall of the FEV 1 /FVC ratio and air pollution was found in a cohort study by Yu et al Acute exposure to PM 10 in non-smoking adults with refractory asthma correlated with a 0.4% drop in the FEV 1 /FVC ratio in the spring [ 89 ]. A longitudinal analysis showed that an increase in PM 10 concentration was associated with increased peak expiratory flow (PEF) variability of >20% and a decrease in the mean PEF among 64 adults with asthma [ 90 ].…”

The prenatal and postnatal effects of air pollution on asthma in children with atopic dermatitis

“…20 PM 2.5 was also associated with poor asthma control and impaired lung function. 21,22 Asthma exacerbation with allergic comorbidity also may be easier influenced by ambient PM 2.5 . 23 Fine PM s can reach the more distal respiratory tract, alveoli, or terminal T A B L E 3 The monthly average concentration of all pollution exposure in 3, 6, and 9 months before birth in children with atopic dermatitis…”

Seasonal Indicators of Blood Pressure, Data of Asthma Control Questionnaires and Quality of Life in Hypertensive Patients with Bronchial Asthma

“…Как говорилось выше, наихудшие показатели ОФВ 1 у больных с АГ+БА были выявлены весной, что, вероятно, отразилось в результатах анкетирования ACQ (неконтролируемая БА). Многие исследования выявили, что наихудшие показатели ФВД у больных с БА были выявлены весной и в тех климатических зонах, где четко прослеживается смена сезонов (зима, весна, лето, осень) [9]. Это, как правило, объясняется тем, что в данных регионах весной отмечается цветение (пыление) растений, к которым имеется сенсибилизация у многих больных БА, а большая часть из нихименно с аллергической формой БА.…”