title: Clinical and Functional Lung Parameters Associated With Frequent Exacerbator Phenotype in Subjects With Severe COPD.
abstract: BACKGROUND
  COPD is currently recognized as a syndrome associated with a high prevalence of comorbidities and various phenotypes. Exacerbations are very important events in the clinical history of COPD because they drive the decline in lung function. In the present study, we aim to identify whether there are any clinical and functional specific features of frequent exacerbators in a population of patients with severe COPD.
  
  
  METHODS
  We conducted a cross-sectional, case control study. All subjects had Global Initiative for Chronic Obstructive Lung Disease (GOLD) stage 3 or 4 COPD (FEV1< 50% predicted). Frequent exacerbators (n= 183) reported ≥2 exacerbations or ≥1 determining hospitalization during the previous 12 months, and infrequent exacerbators (n= 162) reported <2 exacerbations over the last 12 months without hospitalization. Multivariate logistic regression was performed to determine the clinical and functional factors significantly associated with frequent exacerbator status.
  
  
  RESULTS
  Frequent exacerbators had a significantly lower inspiratory capacity percentage predicted. The Motley index (residual volume/total lung capacity percentage) was significantly increased in frequent exacerbators. Infrequent exacerbators had lower Modified Medical Research Council dyspnea scale and BODE index than frequent exacerbators. In the multivariate model, a reduced inspiratory capacity percentage predicted and an increase of residual volume/total lung capacity percentage, BODE index and Modified Medical Research Council dyspnea scale were associated with the frequent exacerbation phenotype.
  
  
  CONCLUSIONS
  Static hyperinflation and respiratory disability, measured by Motley index and Modified Medical Research Council dyspnea scale, respectively, in the same way as the multidimensional BODE index staging system, were independently associated with frequent exacerbation status in subjects with severe COPD.
authors.affiliation: Institute of Respiratory Disease, Department of Cardiac, Thoracic, and Vascular Science, University of Medicine, Bari, Italy. alberto.uniba@gmail.com.
authors.forename: Alberto
authors.initials: A
authors.lastname: Capozzolo
authors.affiliation: Institute of Respiratory Disease, Department of Cardiac, Thoracic, and Vascular Science, University of Medicine, Bari, Italy.
authors.forename: Pierluigi
authors.initials: P
authors.lastname: Carratù
authors.affiliation: Institute of Respiratory Disease, Department of Cardiac, Thoracic, and Vascular Science, University of Medicine, Bari, Italy.
authors.forename: Silvano
authors.initials: S
authors.lastname: Dragonieri
authors.affiliation: Institute of Respiratory Disease, Department of Cardiac, Thoracic, and Vascular Science, University of Medicine, Bari, Italy.
authors.forename: Vito Antonio
authors.initials: VA
authors.lastname: Falcone
authors.affiliation: Institute of Respiratory Disease, Department of Cardiac, Thoracic, and Vascular Science, University of Medicine, Bari, Italy.
authors.forename: Vitaliano Nicola
authors.initials: VN
authors.lastname: Quaranta
authors.affiliation: Institute of Respiratory Disease, Department of Cardiac, Thoracic, and Vascular Science, University of Medicine, Bari, Italy.
authors.forename: Vito
authors.initials: V
authors.lastname: Liotino
authors.affiliation: Institute of Respiratory Disease, Department of Cardiac, Thoracic, and Vascular Science, University of Medicine, Bari, Italy.
authors.forename: Giuseppina
authors.initials: G
authors.lastname: D'Alba
authors.affiliation: Institute of Respiratory Disease, Department of Cardiac, Thoracic, and Vascular Science, University of Medicine, Bari, Italy.
authors.forename: Giorgio
authors.initials: G
authors.lastname: Castellana
authors.affiliation: Institute of Respiratory Disease, Department of Cardiac, Thoracic, and Vascular Science, University of Medicine, Bari, Italy.
authors.forename: Onofrio
authors.initials: O
authors.lastname: Resta
mesh_terms: D000328:Adult; D000368:Aged; D016022:Case-Control Studies; D003430:Cross-Sectional Studies; D018450:Disease Progression; D005260:Female; D006801:Humans; D016015:Logistic Models; D008168:Lung / Q000503:physiopathology; D008297:Male; D008875:Middle Aged; D010641:Phenotype; D029424:Pulmonary Disease, Chronic Obstructive / Q000503:physiopathology*; D012115:Residual Volume / Q000502:physiology; D012307:Risk Factors; D012720:Severity of Illness Index; D014109:Total Lung Capacity / Q000502:physiology
keywords: COPD exacerbations; COPD phenotypes; body plethysmography; respiratory disease; spirometry