title: Increased arterial carboxyhemoglobin concentrations in chronic obstructive pulmonary disease.
abstract: BACKGROUND
  Exhaled carbon monoxide (CO) and arterial blood carboxyhemoglobin concentrations (Hb-CO) increase in inflammatory pulmonary diseases.
  
  
  OBJECTIVE
  To study whether arterial Hb-CO is useful to monitor disease activity in patients with chronic obstructive pulmonary disease (COPD) who had stopped smoking.
  
  
  METHODS
  We measured arterial Hb-CO, arteriovenous Hb-CO differences, and FEV1 in 58 patients with COPD and 61 ex-smoking control subjects.
  
  
  RESULTS
  Arterial Hb-CO concentrations in patients at stable conditions were higher than those in control subjects (p < 0.0001). Furthermore, the Hb-CO concentrations in patients at the exacerbations (p < 0.0001) were higher than those at the stable conditions. Arterial Hb-CO concentrations in patients at stage III were higher than those in patients at stage II, and the Hb-CO concentrations in patients at stage IV were higher than those in patients at stage III at the stable conditions and exacerbations. Arterial Hb-CO correlated with exhaled CO in patients with COPD at stage II and stage III at the exacerbations. Arterial Hb-CO inversely correlated with the arterial blood partial oxygen pressure and FEV1. Arteriovenous Hb-CO differences in patients at the exacerbations did not differ from those in patients at stable conditions and from those in control subjects. Moreover, arterial Hb-CO correlated with serum C-reactive protein values and serum lipid peroxide concentrations.
  
  
  CONCLUSIONS
  These findings suggest that increased arterial Hb-CO may relate to severity in patients with COPD because of lung and systemic inflammation and production of reactive oxygen species.
authors.affiliation: Department of Geriatric and Respiratory Medicine, Tohoku University School of Medicine, 1-1 Seiryo-machi, Aoba-ku, Sendai, 980-8574, Japan. yasuda@geriat.med.tohoku.ac.jp
authors.forename: Hiroyasu
authors.initials: H
authors.lastname: Yasuda
authors.forename: Mutsuo
authors.initials: M
authors.lastname: Yamaya
authors.forename: Katsutoshi
authors.initials: K
authors.lastname: Nakayama
authors.forename: Satoru
authors.initials: S
authors.lastname: Ebihara
authors.forename: Takahiko
authors.initials: T
authors.lastname: Sasaki
authors.forename: Shoji
authors.initials: S
authors.lastname: Okinaga
authors.forename: Daisuke
authors.initials: D
authors.lastname: Inoue
authors.forename: Masanori
authors.initials: M
authors.lastname: Asada
authors.forename: Miyako
authors.initials: M
authors.lastname: Nemoto
authors.forename: Hidetada
authors.initials: H
authors.lastname: Sasaki
mesh_terms: D000368:Aged; D001158:Arteries; D001944:Breath Tests; D002245:Carbon Dioxide / Q000032:analysis; D002263:Carboxyhemoglobin / Q000378:metabolism*; D005260:Female; D006801:Humans; D008297:Male; D029424:Pulmonary Disease, Chronic Obstructive / Q000097:blood* / Q000145:classification / Q000175:diagnosis; D012129:Respiratory Function Tests; D014680:Veins
chemical_list: D002245:Carbon Dioxide; D002263:Carboxyhemoglobin