Clinical Phenotypes and Prognostic Heterogeneity of Mild-to-Moderate Chronic Obstructive Pulmonary Disease: A Prospective Community-Based Cohort Study.

Background

The clinical phenotypes, prognosis, and heterogeneity of mild-to-moderate chronic obstructive pulmonary disease (COPD) have not been systematically evaluated. RESEARCH QUESTION Do different clinical phenotypes of mild-to-moderate COPD have different prognoses? STUDY

Design

AND

Methods

We analysed the baseline and 3-year follow-up data of participants with mild-to-moderate COPD from a prospective community-based cohort study. Mild-to-moderate COPD was defined as a forced expiratory volume in 1 second (FEV1) / forced vital capacity ratio of < 0.70 and FEV1 ≥ 50% of the predicted value. The clinical phenotypes included respiratory symptoms, exacerbation history, emphysema, air trapping, and airway remodelling. Respiratory health outcomes included exacerbations and lung function decline over the 3-year follow-up.

Results

Overall, 806 participants with mild-to-moderate COPD were included, of whom 712 (88%) completed the 3-year follow-up. Participants with mild-to-moderate COPD had more severe emphysema, air trapping, and airway remodelling; increased exacerbation risk; and faster annual FEV1 decline than those with preserved spirometry. The severity of airflow obstruction, respiratory symptoms, emphysema, and air trapping, as well as the eosinophilic phenotype, had low overlap in mild-to-moderate COPD. There was significant individual variation in the annual FEV1 decline rate and exacerbation incidence among participants with mild-to-moderate COPD. Emphysema and air trapping were associated with faster FEV1 decline and higher exacerbation risk. Respiratory symptoms and exacerbations in the previous year were associated with a higher acute exacerbation risk but not with faster lung function decline.

Interpretation

Mild-to-moderate COPD exhibited distinct clinical phenotypes with significant prognostic heterogeneity. Accurate phenotype identification is essential for targeted intervention, clinical precision management, and prognostic improvement.