ATS 2023: Subtypes of Early Chronic Obstructive Pulmonary Disease Could Predict COPD Exacerbation
Purpose: Chronic obstructive pulmonary disease (COPD) is a multifaceted respiratory condition characterized by its heterogeneity. Acute exacerbations, which signify a sudden deterioration in symptoms, are crucial prognostic indicators of the condition. This study aimed to investigate the role of early COPD subtypes in predicting the occurrence of acute exacerbations. To achieve this, cluster analysis—a statistical technique that allows for the identification of distinct subgroups within a larger population—was employed.
Patients and Methods: In order to conduct cluster analysis, six variables were carefully chosen for examination: age, body mass index (BMI), smoking status, smoking pack-years, COPD Assessment Test (CAT) score, and post-bronchodilator forced expiratory volume in 1 second (FEV1)% predicted. A total of 924 participants from the Korea COPD Subgroup Study (KOCOSS) were included in this investigative study. All of these individuals had post-bronchodilator forced expiratory volume in 1 second (FEV1) ≥ 50% predicted and provided complete data for all six variables under investigation. This carefully selected cohort allowed for a comprehensive analysis of the relationships between these variables and the subtypes of early COPD, providing valuable insights into the factors influencing acute exacerbation risk.
Results: With the help of clustering analysis, the patients in this study were categorized into four distinct groups based on relevant variables, which include cluster 1 (n = 224), cluster 2 (n = 235), cluster 3 (n = 248), and cluster 4 (n = 217). Among the four identified clusters, cluster 2 exhibited several distinct characteristics compared to all the other clusters. Firstly, cluster 2 had the highest mean age (74.2 ± 5.4), indicating a relatively older population compared to cluster 1 (68.6 ± 6.7), cluster 3 (63.3 ± 6.6), and cluster 4 (71.9 ± 6.6). Additionally, cluster 2 had the highest smoking pack years (55.3 ± 27.7), indicating a greater cumulative smoking history compared to cluster 1 (42.5 ± 21.8), cluster 3 (37.1 ± 16.0), and cluster 4 (29.8 ± 16.4). Also, cluster 2 had the highest median COPD Assessment Test (CAT) score (17.5 ± 8.1), suggesting a higher symptom burden compared to cluster 1 (12.1 ± 6.7), cluster 3 (12.2 ± 6.5), and cluster 4 (11.4 ± 7.4). Lastly, cluster 2 demonstrated the least favorable 6-minute walk distance (351.7 ± 119.3), implying a lower exercise capacity compared to cluster 1 (396.8 ± 115.9), cluster 3 (427.4 ± 99.4), and cluster 4 (388.2 ± 113.9). Furthermore, Cluster 2 exhibited a higher risk of acute exacerbation (odds ratio [OR] = 1.93, 95% confidence interval [CI] = 1.29–2.88) compared to the remaining clusters. This suggests that individuals belonging to Cluster 2 are more susceptible to experiencing episodes of worsened symptoms and complications associated with their condition, posing a greater need for proactive management and preventive measures to mitigate the risk of acute exacerbations.
Conclusion: The findings derived from this analysis shed light on the presence of a distinct subgroup within the early COPD population that demonstrates an elevated vulnerability to acute exacerbations. This subgroup, identified as being at higher risk, necessitates a more focused and intensified approach to their treatment. By recognizing this subgroup and tailoring treatment strategies accordingly, clinicians can optimize management plans and allocate appropriate resources to mitigate the frequency and severity of acute exacerbations in these individuals.
American Thoracic Society (ATS) 2023 International Conference, 19th May–24th May, 2023, Washington, DC
