Isolated small airways obstruction predicts future chronic airflow obstruction: a multinational longitudinal study

Area of Science:

• Pulmonology
• Respiratory Medicine
• Epidemiology

Background:

• Chronic airflow obstruction is a hallmark of chronic obstructive pulmonary disease (COPD).
• The link between early, isolated small airways obstruction and the later development of chronic airflow obstruction requires further investigation.

Purpose of the Study:

• To determine if isolated small airways obstruction at baseline is associated with the development of chronic airflow obstruction.
• To evaluate the predictive capability of different measures of small airways obstruction.

Main Methods:

• Longitudinal data from the Burden of Obstructive Lung Disease (BOLD) study (n=3957) and UK Biobank (n=26512) were analyzed.
• Isolated small airways obstruction was defined by pre-bronchodilator FEF25-75 < LLN with normal FEV1/FVC, and also by FEV3/FVC < LLN.
• Chronic airflow obstruction was defined as post-bronchodilator FEV1/FVC < LLN.

Main Results:

• Participants with baseline isolated small airways obstruction were more likely to develop chronic airflow obstruction (OR for FEF25-75: 2.95, OR for FEV3/FVC: 1.94).
• FEF25-75 demonstrated superior discrimination for future chronic airflow obstruction compared to FEV3/FVC (AUC 0.764 vs 0.692).
• Findings were consistent in the UK Biobank replication cohort.

Conclusions:

• Measurements of small airways obstruction, particularly FEF25-75, serve as valuable early indicators of future obstructive lung disease.
• Early detection of small airway dysfunction may facilitate timely interventions to prevent COPD progression.