The revised GOLD 2017 COPD categorization in relation to comorbidities

The COPD classification proposed by the Global Initiative for Obstructive Lung Disease was recently revised, and the A to D grouping is now based on symptoms and exacerbations only. Potential associations with comorbidities have not been assessed so far. Thus the aim of the present study was to determine the relationship between the revised (2017) GOLD groups A-D and major comorbidities.

We used baseline data from the COPD cohort COSYCONET. Comorbidities were identified from patient self-reports and disease-specific medication: gastrointestinal disorders, asthma, sleep apnea, hyperuricemia, hyperlipidemia, diabetes, osteoporosis, mental disorders, heart failure, hypertension, coronary artery disease. The A-D groups were based on either the COPD Assessment Test or the modified Medical Research Council scale. Exacerbations were also categorized as per GOLD recommendations.

Data from 2228 patients were analyzed. Using GOLD group A as a reference, group D was associated with nearly all comorbidities, followed by group B and C. When groups A-D were dichotomized as AC vs. BD (symptoms) and AB vs. CD (exacerbations), all comorbidities correlated with symptoms and/or exacerbations. This was true for both mMRC- and CAT-based categorizations.

These findings suggest that the recently modified GOLD categorization is clinically relevant beyond being purely an assessment of symptoms and exacerbations. As the A-D groups correlated with the risk of important comorbidities, with some differences in terms of the correlation with symptoms and exacerbations, the findings underline the importance of identifying comorbidities in COPD, particularly in non-responders to therapy who have high symptoms and/or exacerbation rates.