title: Serum C-reactive protein level in COPD patients stratified according to GOLD 2011 grading classification.
abstract: OBJECTIVE
  The Global Initiative for Chronic Obstructive Lung Disease (GOLD) 2011 grading classification has been used to evaluate the severity of patients with chronic obstructive pulmonary disease (COPD). However, little is known about the relationship between the systemic inflammation and this classification. We aimed to study the relationship between serum CRP and the components of the GOLD 2011 grading classification.
  
  
  METHODS
  C-reactive protein (CRP) levels were measured in 391 clinically stable COPD patients and in 50 controls from June 2, 2015 to October 31, 2015 in the First Affiliated Hospital of Xiamen University. The association between CRP levels and the components of the GOLD 2011 grading classification were assessed.
  
  
  RESULTS
  Correlation was found with the following variables: GOLD 2011 group (0.240), age (0.227), pack year (0.136), forced expiratory volume in one second % predicted (FEV1%; -0.267), forced vital capacity % predicted (-0.210), number of acute exacerbations in the past year (0.265), number of hospitalized exacerbations in the past year (0.165), British medical Research Council dyspnoea scale (0.121), COPD assessment test score (CAT, 0.233). Using multivariate analysis, FEV1% and CAT score manifested the strongest negative association with CRP levels.
  
  
  CONCLUSIONS
  CRP levels differ in COPD patients among groups A-D based on GOLD 2011 grading classification. CRP levels are associated with several important clinical variables, of which FEV1% and CAT score manifested the strongest negative correlation.
authors.affiliation: Yi-Hua Lin, MD, Department of Respiratory Medicine, the First Affiliated Hospital of Xiamen University, Xiamen, Fujian, China.
authors.forename: Yi-Hua
authors.initials: YH
authors.lastname: Lin
authors.affiliation: Wan-Yu Wang, MM, Department of Respiratory Medicine, the First Affiliated Hospital of Xiamen University, Xiamen, Fujian, China.
authors.forename: Wan-Yu
authors.initials: WY
authors.lastname: Wang
authors.affiliation: Su-Xian Hu, MM, Department of Respiratory Medicine, the First Affiliated Hospital of Xiamen University, Xiamen, Fujian, China.
authors.forename: Su-Xian
authors.initials: SX
authors.lastname: Hu
authors.affiliation: Prof. Yong-Hong Shi, Department of Respiratory Medicine, the First Affiliated Hospital of Xiamen University, Xiamen, Fujian, China.
authors.forename: Yong-Hong
authors.initials: YH
authors.lastname: Shi
keywords: C-reactive protein; Chronic obstructive pulmonary disease; GOLD 2011 Grading Classification; Systemic inflammation