title: Prevalence and characteristics of three clinical phenotypes of chronic obstructive pulmonary disease (COPD).
abstract: OBJECTIVE
  To determine the prevalence and analyze the most relevant clinical characteristics of three clinical phenotypes of COPD: emphysema (type 1), chronic bronchitis (type 2) or COPD-asthma (type 3).
  
  
  METHODS
  Observational, multicenter study performed with 331 COPD patients recruited in pulmonology outpatient services. The stratification in three phenotypes was performed with imaging tests, pulmonary function, and a standardized clinical questionnaire.
  
  
  RESULTS
  The 43.2% presented an emphysematous phenotype, 44.7% were chronic bronchitic and the other 12.1% presented a phenotype showing mixed characteristics with asthma. There were no significant differences in the smoking level, in the gasometric values or time of disease evolution. Type 1 patients showed lower FEV1 values in comparison with types 2 and 3, 46.6% (21.1), 55.2% (21.2) and 54.4% (21.8), respectively (p < 0.05), and greater levels of dyspnea (p < 0.05). No significant differences were observed in the percentage of patients who had at least one exacerbation in the last year (68.8%, 63.9%, 64.9%; p = 0.25), in the number of exacerbations (p = 0.56), in the number of visits to the ER (total and due to COPD), or in the number of hospital admittances. Type 2 patients showed a greater prevalence of cardiovascular comorbidities and of sleep apnea syndrome (4.9%, 23.6% and 12.5%, respectively, p < 0.001).
  
  
  CONCLUSIONS
  In COPD, emphysematous patients present worse pulmonary function and greater dyspnea, although there were no differences in the use of hospital health care resources. The greater comorbidity in Group 2 patients may require specific strategies in this subgroup of patients.
authors: Pulmonology Service, University Hospital of Guadalajara, Spain. jlizquierdo@sescam.org
authors: José Luis
authors: JL
authors: Izquierdo-Alonso
authors: Jose Miguel
authors: JM
authors: Rodriguez-Gonzálezmoro
authors: Pilar
authors: P
authors: de Lucas-Ramos
authors: Irune
authors: I
authors: Unzueta
authors: Xabier
authors: X
authors: Ribera
authors: Esther
authors: E
authors: Antón
authors: Antonio
authors: A
authors: Martín
mesh_terms: D000203:Activities of Daily Living; D000368:Aged; D001249:Asthma / Q000453:epidemiology / Q000209:etiology / Q000503:physiopathology; D001991:Bronchitis / Q000453:epidemiology / Q000209:etiology / Q000503:physiopathology; D002317:Cardiovascular Agents / Q000627:therapeutic use; D002908:Chronic Disease; D015897:Comorbidity; D003430:Cross-Sectional Studies; D004417:Dyspnea / Q000453:epidemiology / Q000209:etiology / Q000503:physiopathology; D005260:Female; D005541:Forced Expiratory Volume / Q000502:physiology; D006296:Health Services / Q000706:statistics & numerical data; D006801:Humans; D008297:Male; D008875:Middle Aged; D010641:Phenotype; D015995:Prevalence; D029424:Pulmonary Disease, Chronic Obstructive / Q000150:complications / Q000453:epidemiology* / Q000503:physiopathology; D011656:Pulmonary Emphysema / Q000453:epidemiology / Q000209:etiology / Q000503:physiopathology; D011788:Quality of Life; D013030:Spain / Q000453:epidemiology
chemical_list: D002317:Cardiovascular Agents