COPD P-005 : Clinical Characteristics of Chronic Obstructive Pulmonary Disease in Non- Smoking Patients: Findings from a KOCOSS Cohort

Purpose Although smoking is the most important risk factor for chronic pulmonary disease (COPD), prevalence of COPD in non-smokers has been increasing in the last few years. In this study, we aimed to reveal clinical characteristics of non-smoking COPD from the KOCOSS database. Methods KOCOSS database is a multicenter cohort of COPD patients, recruited from 54 medical centers in South Korea. We extracted patients’ data including general characteristics, smoking habits, past history, Results of pulmonary function tests, history of COPD exacerbations, various symptom scores (mMRC, CAT, SGRQ), and radiologic findings. We analyzed differences of clinical characteristics depending on smoking habits, and annual differences in FEV1 change over 5 years with linear mixed model. Results Of the 2477 patients enrolled in this study, 8.1% were non-smokers. Non-smoking COPD patients were more likely to be female, had higher BMI, less educated, and had more comorbidities such as hypertension, osteoporosis and gastroesophageal reflux disease. Also, non-smoking COPD patients experienced more respiratory and allergic diseases, including bronchiectasis, tuberculosis (TB), childhood respiratory infection and asthma. There were no differences in exacerbation history nor various symptom scores between non-smoking and smoking patients. Radiologic findings showed that smokers showed more emphysematous change, whereas non-smokers were more bronchiectatic and their lung were more frequently destroyed by previous TB. Pulmonary lung function test Results presented lower FEV1 and FVC but higher FEV1/FVC in non-smokers compared to smokers, and annual change showed steeper FEV1 decline rate in smokers compared to non-smokers. Conclusion Our study revealed differences of clinical characteristics between smoking and non-smoking COPD patients, including general characteristics, disease characteristics, and clinical outcomes.