Impact of comorbidities in COPD clinical control criteria. The CLAVE study

Abstract

Background: Chronic obstructive pulmonary disease (COPD) frequently coexists with other chronic diseases, namely comorbidities. They negatively impact prognosis, exacerbations and quality of life in COPD patients. However, no studies have been performed to explore the impact of these comorbidities on COPD clinical control criteria.

Research question: Determine the relationship between individualized comorbidities and COPD clinical control criteria.

Study design and methods: Observational, multicenter, cross-sectional study performed in Spain involving 4801 patients with severe COPD (< 50 predicted forced expiratory volume in the first second [FEV₁%]). Clinical control criteria were defined by the combination of COPD assessment test (CAT) scores (≤16 vs ≥17) and exacerbations in the previous three months (none vs ≥1). Binary logistic regression adjusted by age and FEV₁% was performed to identify comorbidities potentially associated with the lack of control of COPD. Secondary endpoints were the relationship between individualized comorbidities with COPD assessment test and exacerbations within the last three months.

Results: Most frequent comorbidities were arterial hypertension (51.2%), dyslipidemia (36.0%), diabetes (24.9%), obstructive sleep apnea-hypopnea syndrome (14.9%), anxiety (14.1%), heart failure (11.6%), depression (11.8%), atrial fibrillation (11.5%), peripheral arterial vascular disease (10.4%) and ischemic heart disease (10.1%). After age and FEV₁% adjustment, comorbidities related to lack of clinical control were cardiovascular diseases (heart failure, peripheral vascular disease and atrial fibrillation; p < 0.0001), psychologic disorders (anxiety and depression; all p < 0.0001), metabolic diseases (diabetes, arterial hypertension and abdominal obesity; all p < 0.001), sleep disorders (p < 0.0001), anemia (p = 0.015) and gastroesophageal reflux (p < 0.0001). These comorbidities were also related to previous exacerbations and COPD assessment test scores.

Interpretation: Comorbidities are frequent in patients with severe COPD, negatively impacting COPD clinical control criteria. They are related to health-related quality of life measured by the COPD assessment test. Our results suggest that comorbidities should be investigated and treated in these patients to improve their clinical control.

Take-home points: Study question: What is the impact of comorbidities on COPD clinical control criteria?

Results: Among 4801 patients with severe COPD (27.5% controlled and 72.5% uncontrolled), after adjustment by age and FEV₁%, comorbidities related to lack of clinical control were cardiovascular diseases (heart failure, peripheral vascular disease and atrial fibrillation; p < 0.0001), psychologic disorders (anxiety and depression; p < 0.0001), metabolic diseases (diabetes, arterial hypertension and abdominal obesity; p < 0.001), obstructive sleep apnea-hypopnea syndrome (p < 0.0001), anaemia (p = 0.015) and gastroesophageal reflux (p < 0.0001), which were related to previous exacerbations and COPD assessment test scores.

Interpretation: Comorbidities are related to health-related quality of life measured by the COPD assessment test scores and history of exacerbations in the previous three months.

Keywords: CAT: COPD assessment test; COPD: Chronic obstructive pulmonary disease; Charlson index; Clinical control criteria; Comorbidities; Exacerbations.

Fig. 1

Prevalence of individualized comorbidities according to COPD clinical control criteria. Values are represented as percentage and number of patients

Fig. 2

COPD comorbidome. Binary logistic regression adjusted by age and FEV₁% to identify comorbidities potentially associated with the lack of control of COPD. The size of the circles represents the prevalence of individualized diseases, while the distance to the centre represents the odds ratio for diseases and COPD control (the closer the disease is to the center of the figure, the more negative it is for COPD control). The central black circle (center) represents the lack of control of COPD. Green circles: cardiovascular diseases. Yellow circles: metabolic diseases. Blue circles: psychologic disorders. Orange circles: other diseases. Grey circle: dementia. A.O.: abdominal obesity. CVD: cerebrovascular diseases. H.F.: heart failure. aPVD: arterial periferic vascular disease. A.F.: atrial fibrillation. DEP: depression. ANX: anxiety. OST: osteoporosis. GER: gastroesophageal reflux. AN: anaemia. OAHAS: obstructive apnoea-hypopnoea syndrome. D.M.: diabetes mellitus: D.M.*: diabetes mellitus with organ damage. D: dementia

Fig. 3

Median CAT scores (A) and number of exacerbations in the previous year (B) in individualized comorbidities