title: Evaluation of BODE index and its relationship with systemic inflammation mediated by proinflammatory biomarkers in patients with COPD.
abstract: BACKGROUND
  BODE index, a multidimensional grading system which is based on Body mass index, airway Obstruction, Dyspnea scale, and Exercise capacity, has been increasingly used for the evaluation of chronic obstructive pulmonary disease (COPD). Many of the systemic manifestations of COPD are shown to be mediated by elevated levels of proinflammatory biomarkers.
  
  
  OBJECTIVE
  We aimed to investigate the relationship between the BODE index, its components, disease severity, and proinflammatory biomarkers like C-reactive protein (CRP), tumor necrosis factor (TNF)-α, and interleukin (IL)-6.
  
  
  METHODS
  A cross-sectional study which included 290 clinically stable COPD patients and 80 smoker controls was conducted. Medical history, body mass index, pulmonary function tests, 6-minute walking test, and modified scale of Medical Research Council dyspnea scale were evaluated. BODE scores were determined. Systemic inflammation was evaluated with the measurement of CRP, TNF-α, and IL-6 in the serum samples of all studied subjects. The correlation between inflammatory biomarkers and BODE index was assessed in COPD patients.
  
  
  RESULTS
  We found a significant relationship between COPD stages and BODE index. Our analysis showed significant association between systemic biomarkers and components of the BODE index. Both TNF-α and CRP levels exhibited weak but significant correlation with BODE index. Serum IL-6 concentrations exhibited significant correlation with 6-minute walking test, modified scale of Medical Research Council, and BODE index (r=0.201,P=0.004;r=0.068,P=0.001; andr=0.530,P=0.001, respectively). Also, an inverse and significant correlation was observed between BODE index and FEV1 (r=0.567,P=0.001). IL-6 exhibited a highly significant and inverse correlation with FEV1 (r=-0.580,P=0.001).
  
  
  CONCLUSIONS
  BODE index should be considered for evaluating patients with COPD. Also, IL-6 seems to be a potential biomarker that may enable determination of the severity and prediction of the course of the disease.
authors.affiliation: Department of Medicine, Maulana Azad Medical College; Department of Biosciences, Jamia Millia Islamia.
authors.forename: Naushad Ahmad
authors.initials: NA
authors.lastname: Khan
authors.affiliation: Department of Medicine, Maulana Azad Medical College.
authors.forename: Mradul Kumar
authors.initials: MK
authors.lastname: Daga
authors.affiliation: Department of Biosciences, Jamia Millia Islamia.
authors.forename: Istaq
authors.initials: I
authors.lastname: Ahmad
authors.affiliation: Department of Medicine, Maulana Azad Medical College.
authors.forename: Govind
authors.initials: G
authors.lastname: Mawari
authors.affiliation: Department of Microbiology, Maulana Azad Medical College, New Delhi, India.
authors.forename: Suman
authors.initials: S
authors.lastname: Kumar
authors.affiliation: Department of Medicine, Maulana Azad Medical College.
authors.forename: Naresh
authors.initials: N
authors.lastname: Kumar
authors.affiliation: Department of Biosciences, Jamia Millia Islamia.
authors.forename: Syed Akhter
authors.initials: SA
authors.lastname: Husain
keywords: BODE index; biomarkers; chronic obstructive pulmonary disease; systemic inflammation