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Persistent Airflow Limitation in Asthma: Clinical Characteristics, Risk Factors, and Long-term Outcomes from a
Jung-Kyu Lee1, Hyun-Woo Lee1, Chang Hoon Lee2
1Division of Pulmonary and Critical Care Medicine, Department of Internal Medicine, Seoul Metropolitan Government-Seoul National University Boramae Medical Center, Seoul National University College of Medicine, Seoul, Republic of Korea.
Journal of Asthma and Allergy
|July 14, 2026
Summary
Persistent airflow limitation (PAL) in asthma predicts severe exacerbations and lung function decline. PAL severity is linked to increased risk, highlighting it as a key marker for disease progression and intervention.
Area of Science:
- Pulmonology
- Asthma Research
- Clinical Epidemiology
Background:
- Persistent airflow limitation (PAL) is an emerging asthma phenotype with unclear real-world prevalence and prognostic significance.
- Understanding PAL's clinical characteristics and long-term outcomes is crucial for asthma management.
Purpose of the Study:
- To evaluate the prevalence, determinants, and prognostic significance of PAL in asthma patients.
- To assess the impact of PAL severity on exacerbations and lung function decline.
Main Methods:
- Multicenter analysis of South Korean retrospective and prospective asthma cohorts.
- PAL defined as post-bronchodilator FEV1/FVC <0.70; severity graded by STaging of Airflow obstruction by Ratio (STAR) classification.
- Outcomes included severe exacerbations and longitudinal lung function changes.
Main Results:
- 75.4% of 849 asthma patients had PAL, associated with older age, male sex, higher smoking intensity, and lower FEV1.
- PAL significantly increased the risk of severe exacerbations (IRR 1.77) and this risk escalated with PAL severity (STAR stage 4 vs 0: aHR 3.32).
- Annual FEV1 decline was slower in PAL patients overall (-28.1 mL/year) but faster in severe PAL (STAR stage 4).
Conclusions:
- PAL and its severity are independent predictors of severe exacerbations and progressive lung function decline in asthma.
- PAL serves as a critical marker for asthma progression.
- Early intervention targeting PAL may be beneficial for improving long-term asthma outcomes.
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