The revised GOLD 2017 COPD categorization in relation to comorbidities

The chronic obstructive pulmonary disease (COPD) classification proposed by the Global Initiative for Obstructive Lung Disease (GOLD) was recently revised, with the A to D grouping now based on symptoms and exacerbations only (with no consideration of lung function). Patients with COPD show more comorbidities than non-COPD populations but the potential for associations between the new GOLD grouping and comorbidities has 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 ( CO PD and Sy stemic Co nsequences-Comorbidities Net work). Comorbidities were identified from patient self-reports and disease-specific medication, as follows: gastrointestinal disorders, asthma, sleep apnea, hyperuricemia, hyperlipidemia, diabetes, osteoporosis, mental disorders, heart failure, hypertension, coronary artery disease, cardiovascular complex. GOLD groups A-D were dichotomized as AC vs. BD (symptoms) and AB vs. CD (exacerbations). The A-D groups were based on either the COPD Assessment Test (CAT) or the modified Medical Research Council (mMRC) scale, as described by GOLD. Exacerbations were also categorized as per GOLD recommendations. Data from 2228 patients were analyzed. All investigated comorbidities correlated with GOLD groups in terms of the binary categories symptoms and/or exacerbations (p < 0.05 each). This was true for both mMRC- and CAT-based categorizations. Moreover, the 2017 GOLD grouping had a greater number of correlations with comorbidities than the former (2011) grouping. These findings suggest that the recently modified GOLD A-D 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 exacerbation rates.