title: Anemia of chronic disease in chronic obstructive pulmonary disease: a case-control study of cardiopulmonary exercise responses.
abstract: BACKGROUND
  Anemia may be present in patients with chronic obstructive pulmonary disease (COPD) and further impair their functional capacity.
  
  
  OBJECTIVE
  This study investigated the prevalence of anemia of chronic disease (ACD) in COPD patients and its impact on dyspnea and exercise capacity, utilizing cardiopulmonary exercise testing (CPET).
  
  
  METHODS
  ACD prevalence was assessed in 283 consecutive patients with stable COPD (263 males, 60 females; age 60.31 ± 5.34 years; percent forced expiratory volume in 1 s 46.94 ± 6.12). ACD diagnosis was based on a combination of clinical and laboratory parameters [hemoglobin (Hb) <13 g/dl for males, <12 g/dl for females; ferritin >30 ng/ml; total iron-binding capacity <250 μg/dl, and transferrin saturation rate between 15 and 50%]. Twenty-seven patients who were identified with ACD (cases) and 27 matched nonanemic patients (controls) completed maximal CPET, and data were compared between the groups.
  
  
  RESULTS
  ACD was diagnosed in 29 patients, which represents a prevalence of 10.24%; the severity of anemia was generally mild (mean Hb: 12.19 ± 0.66 g/dl). Patients with ACD had a higher Medical Research Council dyspnea score compared to controls (2.78 ± 0.44 vs. 2.07 ± 0.55; p <0.001) and lower peak O(2) uptake (VO(2)) (59.54 ± 17.17 vs. 71.26 ± 11.85% predicted; p <0.05), peak work rate (54.94 ± 21.42 vs. 68.72 ± 20.81% predicted; p <0.05) and peak VO(2)/heart rate (69.07 ± 17.26 vs. 82.04 ± 18.22% predicted; p <0.05). There was also a trend for a lower anaerobic threshold (48.48 ± 15.16 vs. 55.42 ± 9.99% predicted; p = 0.062). No exercise parameter indicative of respiratory limitation differed between the groups.
  
  
  CONCLUSIONS
  ACD occurs in approximately 10% of stable COPD patients and has a negative impact on dyspnea and circulatory efficiency during exercise.
authors.affiliation: Respiratory Failure Unit, Aristotle University of Thessaloniki, G. Papanikolaou Hospital, Thessaloniki, Greece. afboutou@yahoo.com
authors.forename: Afroditi K
authors.initials: AK
authors.lastname: Boutou
authors.forename: Ioannis
authors.initials: I
authors.lastname: Stanopoulos
authors.forename: Georgia G
authors.initials: GG
authors.lastname: Pitsiou
authors.forename: Theodoros
authors.initials: T
authors.lastname: Kontakiotis
authors.forename: George
authors.initials: G
authors.lastname: Kyriazis
authors.forename: Lazaros
authors.initials: L
authors.lastname: Sichletidis
authors.forename: Paraskevi
authors.initials: P
authors.lastname: Argyropoulou
mesh_terms: D000740:Anemia / Q000097:blood / Q000209:etiology* / Q000503:physiopathology; D016022:Case-Control Studies; D003430:Cross-Sectional Studies; D004921:Erythropoietin / Q000378:metabolism*; D005080:Exercise Test; D005260:Female; D005293:Ferritins / Q000378:metabolism*; D005541:Forced Expiratory Volume; D006454:Hemoglobins / Q000378:metabolism*; D006801:Humans; D008297:Male; D008875:Middle Aged; D029424:Pulmonary Disease, Chronic Obstructive / Q000097:blood / Q000150:complications* / Q000503:physiopathology
chemical_list: D006454:Hemoglobins; D004921:Erythropoietin; D005293:Ferritins