Abstract
Introduction: Small-airway dysfunction (SAD) is an important functional hallmark of COPD and can be identified by respiratory oscillometry (OSc). The pathophysiology of COPD development may be easier to delineate in younger adults. We hypothesised SAD would be present in a cohort of young smokers, at risk of developing COPD in their later life, before lung function became abnormal.
Methods: We identified a multi-centre cohort of smokers, aged 30-45 yrs, with >10 pack-yrs tobacco history and normal (>80% predicted) FEV1. Osc assessed resistance from 5 to 20 Hz (R5-R20), reactance at 5 Hz (X5), and resonant frequency (FRes) as markers of SAD. The cohort was then dichotimized into patients with and without SAD, to R5-R20 ≥0.07 or <0.07 kPa/l/sec, respectively.
Results: Of 407 participants (57% males; median age 39 yr), 61 (15.0%) demonstrated SAD (abnormal R5-R20). SAD was associated with lower FEV1 (98.6 vs 105%, p=0.004) and higher mean CAT score (13.4 vs 10.8, p=0.002) (Figure), whilst lung volumes and gas transfer measurements were poorer. Additionally worse R5-R20, X5, and FRes were associated with CAT score ≥10.
Discussion: In a cohort with normal lung function and without comorbidities at risk of developing COPD, we identified ~1/6th with detectable SAD who exhibit higher CAT scores and are more symptomatic. Patients with symptoms but normal FEV1 should prompt us to think early about COPD development.
Footnotes
Cite this article as Eur Respir J 2022; 60: Suppl. 66, 3604.
This article was presented at the 2022 ERS International Congress, in session “-”.
This is an ERS International Congress abstract. No full-text version is available. Further material to accompany this abstract may be available at www.ers-education.org (ERS member access only).
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