The presence of gastroesophageal reflux disease (GERD) and/or nasal symptoms is associated with an increase in bronchitis symptoms in patients with chronic obstructive pulmonary disease (COPD), according to the results of a study published in Respiratory Investigation. As a result, extrapulmonary comorbidities should be assessed in patients with COPD and bronchitis.
Cough and sputum production are symptoms of bronchitis and are established risk factors for worse outcomes in patients with COPD. As GERD is a common cause of a chronic cough and is also known to be a common comorbidity in COPD, the assessment of this and other extrapulmonary comorbidities in patients with COPD is essential.
Researchers conducted a cross-sectional study in 99 patients with stable COPD to quantify bronchitis symptoms and assess the effects of GERD and nasal symptoms on bronchitis severity.
Cough and Sputum Assessment Questionnaire
Patients completed the COPD assessment test and Cough and Sputum Assessment Questionnaire to quantify bronchitis symptoms. The Frequency Scale for Symptoms of GERD questionnaire and nasal symptom questionnaire were completed to determine extrapulmonary comorbidities.
The investigators found symptoms of GERD in 24.2% of the study population, and this was associated with more sputum symptoms. They found nasal discharge in 43.4% of participants, which was associated with more cough and sputum symptoms, whereas postnasal drip, found in 13.1%, was associated with more cough.
Multivariate analysis showed that nasal discharge was associated with more cough, and GERD and postnasal drip were associated with more sputum symptoms.
The authors noted that GERD symptoms affected the severity of both cough and sputum symptoms significantly, whereas nasal discharge and postnasal drip were related significantly to cough severity and sputum symptoms. These findings suggest that more severe symptoms in COPD may be related to comorbidities rather than to the pulmonary pathology itself.
Clinical management of COPD
The authors argued that in addition to the importance of extrapulmonary causes of cough in clinical management of COPD, these causes should also be considered in clinical studies. They suggested that the therapeutic benefit of drugs targeting airway pathology in COPD may be underestimated if patients with cough and sputum symptoms caused by extrapulmonary factors are included.
One of the limitations of this study is that the assessment of extrapulmonary comorbidities was based on questionnaires. Furthermore, details regarding underlying nasal pathology were not available and therefore their relevance to the cough and sputum symptoms could not be evaluated.
Nonetheless, the authors recommended that these extrapulmonary causes of a cough and sputum should be explored when assessing symptoms of bronchitis in patients with COPD.