title: Nontuberculosis mycobacterium disease is a risk factor for chronic obstructive pulmonary disease: a nationwide cohort study.
abstract: BACKGROUND
  The aim of this study was to evaluate the association between chronic obstructive pulmonary disease (COPD) and nontuberculosis mycobacterium (NTM) disease.
  
  
  METHODS
  We used data from the National Health Insurance Research Database of Taiwan in this study. The NTM cohort contained 3,005 patients, and each case was randomly frequency matched by age, sex, income, occupation, and index year with four people from the general population without NTM infections. Multivariate Cox proportional hazards regression was used to calculate adjusted hazard ratios (aHR) of COPD in the NTM cohort compared with the non-NTM cohort.
  
  
  RESULTS
  The incidence of COPD was 3.08-fold higher (21.75 vs. 6.11 per 1,000 person-years) in the NTM cohort than in the non-NTM cohort. The aHR of COPD comparing the NTM cohort with the non-NTM cohort was 3.57 (95 % CI 2.56-4.97) for women and 2.89 (95 % CI 2.31-3.61) for men. The aHR of COPD was higher in the patients with NTM infection and a comorbidity such as bronchopneumonia, pneumonia, diabetes, asthma, and heart disease. The Mycobacterium avium-intracellulare complex group (MAC) and the non-MAC group were isolated in the NTM cohort. The MAC group had a higher aHR of COPD than the non-NTM cohort (aHR = 3.72, 95 % CI 2.94-4.72). The cumulative incidence of COPD in the NTM cohort was higher than in the non-NTM cohort (P < 0.0001, log rank test).
  
  
  CONCLUSIONS
  Physicians should be aware of indolent NTM disease that increases the risk of COPD.
authors.affiliation: Department of Chest Medicine and Family Medicine, Ditmanson Medical Foundation, Chia-Yi Christian Hospital, Chiayi, Taiwan.
authors.forename: Jun-Jun
authors.initials: JJ
authors.lastname: Yeh
authors.forename: Yu-Chiao
authors.initials: YC
authors.lastname: Wang
authors.forename: Fung-Chang
authors.initials: FC
authors.lastname: Sung
authors.forename: Christine Yi-Ting
authors.initials: CY
authors.lastname: Chou
authors.forename: Chia-Hung
authors.initials: CH
authors.lastname: Kao
mesh_terms: D000367:Age Factors; D000368:Aged; D016009:Chi-Square Distribution; D015897:Comorbidity; D016208:Databases, Factual; D005260:Female; D006801:Humans; D015994:Incidence; D053208:Kaplan-Meier Estimate; D008297:Male; D008875:Middle Aged; D015999:Multivariate Analysis; D009165:Mycobacterium Infections, Nontuberculous / Q000175:diagnosis / Q000453:epidemiology / Q000382:microbiology*; D009170:Nontuberculous Mycobacteria / Q000302:isolation & purification / Q000472:pathogenicity*; D016016:Proportional Hazards Models; D029424:Pulmonary Disease, Chronic Obstructive / Q000175:diagnosis / Q000453:epidemiology / Q000382:microbiology*; D012141:Respiratory Tract Infections / Q000175:diagnosis / Q000453:epidemiology / Q000382:microbiology*; D012189:Retrospective Studies; D012307:Risk Factors; D012737:Sex Factors; D013624:Taiwan / Q000453:epidemiology