title: D-dimer as a potential biomarker for the progression of COPD.
abstract: BACKGROUND
  D-dimer is a manifestation of endogenous fibrinolytic activity and associated with inflammation process. Despite chronic obstructive pulmonary disease (COPD) is a chronic inflammatory disease characterized by a hypercoagulable state, D-dimer levels in COPD patients are still conflicting.
  
  
  METHODS
  Forty-three participants were investigated at admission for an acute exacerbation of COPD, and reassessed when stable. Forty-three controls were matched for age, gender, body mass index, smoking index, comorbidities and medication use. Participants underwent pulmonary function and laboratory testing, including the measurements of D-dimer and high-sensitivity C-reactive protein (hsCRP).
  
  
  RESULTS
  The median of D-dimer was 2839 μg/l (IQR: 2078-4389 μg/l) and 1799 μg/l (IQR: 1205-2196 μg/l) in exacerbated and stable COPD patients respectively. The median of D-dimer in the control subjects was 433 μg/l (IQR: 369-456 μg/l). D-dimer level was significantly increased in stable COPD patients compared with healthy controls, and further increased in those patients with an acute exacerbation (both P<0.001). D-dimer was positively correlated with the well-known inflammatory marker hsCRP both in the exacerbated and stable phases of COPD (r=0.392 P=0.009 and r=0.411 P=0.006, respectively), and negatively correlated with FEV1% predicted and FEV1/FVC in stable COPD (r=-0.409 P=0.006 and r=-0.343 P=0.024, respectively).
  
  
  CONCLUSIONS
  D-dimer is increased in COPD patients, and could be considered as an inflammatory marker for the assessment of inflammation in the progression of COPD.
authors.affiliation: Department of Respiratory Medicine, The Second Affiliated Hospital of Xi'an Jiaotong University, Xi'an, Shaanxi, China.
authors.forename: Ming
authors.initials: M
authors.lastname: Zhang
authors.affiliation: Department of Respiratory Medicine, The Second Affiliated Hospital of Xi'an Jiaotong University, Xi'an, Shaanxi, China.
authors.forename: Jie
authors.initials: J
authors.lastname: Zhang
authors.affiliation: Department of Respiratory Medicine, The Second Affiliated Hospital of Xi'an Jiaotong University, Xi'an, Shaanxi, China.
authors.forename: Qiuhong
authors.initials: Q
authors.lastname: Zhang
authors.affiliation: Department of Respiratory Medicine, The Second Affiliated Hospital of Xi'an Jiaotong University, Xi'an, Shaanxi, China.
authors.forename: Xia
authors.initials: X
authors.lastname: Yang
authors.affiliation: Department of Respiratory Medicine, The Second Affiliated Hospital of Xi'an Jiaotong University, Xi'an, Shaanxi, China.
authors.forename: Hu
authors.initials: H
authors.lastname: Shan
authors.affiliation: Department of Respiratory Medicine, The Second Affiliated Hospital of Xi'an Jiaotong University, Xi'an, Shaanxi, China.
authors.forename: Zongjuan
authors.initials: Z
authors.lastname: Ming
authors.affiliation: Department of Respiratory Medicine, The Second Affiliated Hospital of Xi'an Jiaotong University, Xi'an, Shaanxi, China.
authors.forename: Haijuan
authors.initials: H
authors.lastname: Chen
authors.affiliation: Department of Respiratory Medicine, The Second Affiliated Hospital of Xi'an Jiaotong University, Xi'an, Shaanxi, China.
authors.forename: Yanqin
authors.initials: Y
authors.lastname: Liu
authors.affiliation: Department of Laboratory Examination, The Second Affiliated Hospital of Xi'an Jiaotong University, Xi'an, Shaanxi, China.
authors.forename: Jiafeng
authors.initials: J
authors.lastname: Yin
authors.affiliation: Department of Respiratory Medicine, The Second Affiliated Hospital of Xi'an Jiaotong University, Xi'an, Shaanxi, China. Electronic address: 81276894@qq.com.
authors.forename: Yali
authors.initials: Y
authors.lastname: Li
mesh_terms: D000368:Aged; D015415:Biomarkers / Q000097:blood*; D016022:Case-Control Studies; D018450:Disease Progression; D005260:Female; D005338:Fibrin Fibrinogen Degradation Products / Q000378:metabolism*; D006801:Humans; D008297:Male; D008875:Middle Aged; D029424:Pulmonary Disease, Chronic Obstructive / Q000097:blood / Q000503:physiopathology*
chemical_list: D015415:Biomarkers; D005338:Fibrin Fibrinogen Degradation Products; C036309:fibrin fragment D
keywords: C-reactive protein; Chronic obstructive pulmonary disease; D-dimer; Hypercoagulable state; Inflammation; Pulmonary function