NCT07261774

The Impact of Extreme Heat Waves and Air Pollution on the Prognosis of Chronic Airway Diseases

• Status: Completed
• Phase: —
• Study type: Observational
• Enrollment: 96 (actual)
• Sponsor: Mersin University · Academic / Other
• Sex: All
• Age: 18 Years
• Healthy volunteers: Not accepted

Summary

Extreme heat waves (EHW) and air pollution exacerbate chronic airway diseases, but little is known about how these environmental stressors affect quality of life, airway inflammation, symptom control, and pulmonary function. This study was designed to determine the impact of EHW and air pollution on asthma and COPD. This was a prospective cohort study conducted among individuals with asthma and COPD in Mersin, Türkiye, between February 14 and December 1, 2024. Meteorological and air quality index (AQI) data were obtained from official sources. Participants underwent pulmonary function tests (PFTs) and fractional exhaled nitric oxide (FeNO) measurements during periods of normal weather conditions and repeated assessments during documented EHW periods. Patient-reported outcomes included the Asthma Control Test (ACT) and Asthma Quality of Life Questionnaire (AQLQ) for asthma, and the Modified Medical Research Council (mMRC) scale and COPD Assessment Test (CAT) for COPD. Exacerbation episodes requiring systemic corticosteroid use or hospitalization were also recorded. The study aimed to evaluate the effects of EHW and air pollution on disease control, quality of life, lung function, airway inflammation, and exacerbation burden in patients with asthma and COPD.

Detailed description

Climate change has led to a global increase in temperatures, and according to NASA, 2024 was the hottest year on record since 1850. Extreme heatwaves (EHW) represent one of the most significant manifestations of this crisis. While the adverse effects of air pollution on chronic respiratory diseases are well documented, the impact of extreme heatwaves on asthma and chronic obstructive pulmonary disease (COPD) has received less attention. This study was designed to prospectively evaluate the effects of extreme heatwaves and air pollution on patients with asthma and COPD. The study was conducted in Mersin, Türkiye, between February and December 2024. Individuals with physician-diagnosed asthma or COPD who attended the outpatient clinic were enrolled. Baseline assessments were performed on days with normal seasonal weather. Lung function was measured using spirometry, and airway inflammation was assessed using fractional exhaled nitric oxide (FeNO). Symptom control and quality of life were measured using validated questionnaires: the Asthma Control Test (ACT) and Asthma Quality of Life Questionnaire (AQLQ) for patients with asthma, and the Modified Medical Research Council (mMRC) scale and COPD Assessment Test (CAT) for patients with COPD. Meteorological variables, including temperature, humidity, and wind, as well as daily air pollution levels, were obtained from official sources. On documented extreme heatwave days, participants were recalled for follow-up visits. At these visits, spirometry, FeNO, and questionnaire assessments were repeated. Information regarding exacerbation episodes requiring systemic corticosteroid use or hospitalization during the study period was also collected. The study was designed to compare patient-level outcomes between normal weather days and extreme heatwave days. The overall objective was to investigate how environmental stressors such as heat and air pollution influence disease control, quality of life, symptoms, lung function, and airway inflammation in patients with asthma and COPD.

Conditions

• Asthma (Diagnosis)
• COPD (Chronic Obstructive Pulmonary Disease)

Timeline

• Start date: 2024-03-06
• Primary completion: 2024-11-07
• Completion: 2024-12-01
• First posted: 2025-12-03
• Last updated: 2025-12-03

Locations

1 site across 1 country: Turkey (Türkiye)