title: Red blood cell distribution and survival in patients with chronic obstructive pulmonary disease.
abstract: BACKGROUND
  Cardiovascular disease (CVD) contributes significantly to mortality in chronic obstructive pulmonary disease (COPD). Red blood cell distribution width (RDW), an automated measure of red blood cell size heterogeneity that is largely overlooked, is a newly recognized mortality marker in patients with established CVD. It is unknown whether RDW is associated with mortality in COPD patients.
  
  
  OBJECTIVE
  To study the prognostic value of RDW in patients with COPD and to compare the value of this measurement with cardiac, respiratory, and hemotological status.
  
  
  METHODS
  We performed retrospective analyses of 270 patients stable with COPD who were admitted to our hospital between January 2007 and December 2009. Demographic, clinical, echocardiographic, and laboratory characteristics were registered and recorded COPD deaths were registered as outcomes.
  
  
  RESULTS
  In the overall patients, the RDW level had a mean value of 15.1 ± 2.4. RDW was positively correlated with C-reactive protein (CRP) (p = 0.008, r = 0.21), right ventricular dysfunction (RVD) (p < 0.001, r = 0.25), and pulmonary arterial hypertension (PAH) (p = 0.03, r = 0.14). Variables (p < 0.1) included in the univariate survival analysis were forced expiratory volume in 1 second (FEV1% predicted), RDW levels, age, PaCO2, albumine and CRP levels, presence of CVD, presence of anemia, presence of RVD, and presence of PAH. Subsequent multivariate analysis suggested that RDW levels (1.12; 95% CI, 1.01 to 1.24; p = 0.01), and presence of RVD (2.6; 95% CI, 1.19 to 5.8; p = 0.01) were independently related to mortality.
  
  
  CONCLUSIONS
  Elevated RDW levels were associated with increased mortality risk in stable COPD patients.
authors.affiliation: Yedikule Teaching Hospital for Chest Diseases and Thoracic Surgery, Istanbul, Turkey. drekremcs@yahoo.com
authors.forename: Ekrem Cengiz
authors.initials: EC
authors.lastname: Seyhan
authors.forename: Mehmet Akif
authors.initials: MA
authors.lastname: Özgül
authors.forename: Nuri
authors.initials: N
authors.lastname: Tutar
authors.forename: Imran
authors.initials: I
authors.lastname: Ömür
authors.forename: Atilla
authors.initials: A
authors.lastname: Uysal
authors.forename: Sedat
authors.initials: S
authors.lastname: Altin
mesh_terms: D000368:Aged; D002097:C-Reactive Protein / Q000378:metabolism; D015897:Comorbidity; D004452:Echocardiography; D004562:Electrocardiography; D004909:Erythrocyte Indices; D004912:Erythrocytes; D065627:Familial Primary Pulmonary Hypertension; D005260:Female; D005541:Forced Expiratory Volume; D006801:Humans; D006976:Hypertension, Pulmonary / Q000000981:diagnostic imaging / Q000453:epidemiology*; D053208:Kaplan-Meier Estimate; D008297:Male; D008875:Middle Aged; D029424:Pulmonary Disease, Chronic Obstructive / Q000097:blood* / Q000401:mortality* / Q000503:physiopathology; D012189:Retrospective Studies; D015996:Survival Rate; D018497:Ventricular Dysfunction, Right / Q000000981:diagnostic imaging / Q000453:epidemiology*
chemical_list: D002097:C-Reactive Protein