BACKGROUND Multiple comorbidities related to chronic obstructive pulmonary disease (COPD) make it a difficult disease to treat. The relationship between these comorbidities and COPD has not been fully investigated. We aimed to determine whether COPD was independently associated with various comorbidities.

METHODS This was a cross-sectional study, which used data from the Korean National Health and Nutrition Examination Survey (KNHANES) V conducted between 2010 and 2012. Survey design analysis was employed to determine the association between COPD and 15 comorbidities. A COPD patient was defined as a smoker with forced expiratory volume in 1 s (FEV1)/forced vital capacity (FVC) < 0.7 and comorbidities were defined based on objective laboratory findings and questionnaires.

RESULTS Of a total of 9488 patient who underwent spirometry, 744 (7.84%) COPD cases and 3313 non-COPD controls were included in the analyses. Although the prevalence rates of the majority of the comorbidities were high among the COPD patients, only hypertension (adjusted odds ratio [aOR], 1.63; 95% CI, 1.13-2.33 in Stage 1 COPD group; aOR, 1.92; 95% CI, 1.36-2.72 in Stage 2-4 COPD group) and a history of pulmonary tuberculosis (aOR, 3.38; 95% CI, 1.90-5.99 in Stage 2-4 COPD group) were independently associated with COPD after adjustment for age, smoking status, and confounders.

CONCLUSIONS Only hypertension and a history of pulmonary tuberculosis were independently associated with COPD after adjustment for confounders among 15 comorbidities. The results suggest that majority of COPD patients might have similar risk factors with its comorbidities, including age and smoking status.