title: The relationship between chronic obstructive pulmonary disease and comorbidities: a cross-sectional study using data from KNHANES 2010-2012.
abstract: 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.
authors.affiliation: Department of Internal Medicine, Seoul National University College of Medicine, Division of Pulmonary and Critical Care Medicine, Seoul National University Hospital, Republic of Korea.
authors.forename: Yong Suk
authors.initials: YS
authors.lastname: Jo
authors.affiliation: Department of Internal Medicine, Seoul National University College of Medicine, Division of Pulmonary and Critical Care Medicine, Seoul National University Hospital, Republic of Korea.
authors.forename: Sun Mi
authors.initials: SM
authors.lastname: Choi
authors.affiliation: Department of Internal Medicine, Seoul National University College of Medicine, Division of Pulmonary and Critical Care Medicine, Seoul National University Hospital, Republic of Korea.
authors.forename: Jinwoo
authors.initials: J
authors.lastname: Lee
authors.affiliation: Department of Internal Medicine, Seoul National University College of Medicine, Division of Pulmonary and Critical Care Medicine, Seoul National University Hospital, Republic of Korea.
authors.forename: Young Sik
authors.initials: YS
authors.lastname: Park
authors.affiliation: Department of Internal Medicine, Seoul National University College of Medicine, Division of Pulmonary and Critical Care Medicine, Seoul National University Hospital, Republic of Korea.
authors.forename: Sang-Min
authors.initials: SM
authors.lastname: Lee
authors.affiliation: Department of Internal Medicine, Seoul National University College of Medicine, Division of Pulmonary and Critical Care Medicine, Seoul National University Hospital, Republic of Korea.
authors.forename: Jae-Joon
authors.initials: JJ
authors.lastname: Yim
authors.affiliation: Department of Internal Medicine, Seoul National University College of Medicine, Division of Pulmonary and Critical Care Medicine, Seoul National University Hospital, Republic of Korea.
authors.forename: Chul-Gyu
authors.initials: CG
authors.lastname: Yoo
authors.affiliation: Department of Internal Medicine, Seoul National University College of Medicine, Division of Pulmonary and Critical Care Medicine, Seoul National University Hospital, Republic of Korea.
authors.forename: Young Whan
authors.initials: YW
authors.lastname: Kim
authors.affiliation: Department of Internal Medicine, Seoul National University College of Medicine, Division of Pulmonary and Critical Care Medicine, Seoul National University Hospital, Republic of Korea.
authors.forename: Sung Koo
authors.initials: SK
authors.lastname: Han
authors.affiliation: Department of Internal Medicine, Seoul National University College of Medicine, Division of Pulmonary and Critical Care Medicine, Seoul National University Hospital, Republic of Korea. Electronic address: kauri670@empal.com.
authors.forename: Chang-Hoon
authors.initials: CH
authors.lastname: Lee
mesh_terms: D000368:Aged; D015897:Comorbidity; D003430:Cross-Sectional Studies; D005260:Female; D005541:Forced Expiratory Volume / Q000502:physiology; D006801:Humans; D006973:Hypertension / Q000453:epidemiology; D008297:Male; D008875:Middle Aged; D009749:Nutrition Surveys; D015995:Prevalence; D029424:Pulmonary Disease, Chronic Obstructive / Q000453:epidemiology* / Q000503:physiopathology; D056910:Republic of Korea / Q000453:epidemiology; D012907:Smoking / Q000453:epidemiology; D014397:Tuberculosis, Pulmonary / Q000453:epidemiology; D014797:Vital Capacity / Q000502:physiology
keywords: COPD; Comorbidities; GOLD; KNHANES; Survey analysis