The relationship between C-reactive protein and prognostic factors in chronic obstructive pulmonary disease

Background: The purpose of the study was to determine the relationship between high sensitivity C-reactive protein (hs-CRP) levels and prognostic factors in chronic obstructive pulmonary disease. Methods: We studied 50 stable COPD patients with: spirometry, 6 minute walk distance, body mass index, GOLD stage (spirometric classification) and smoking status. In these patients hs-CRP values were measured and compared with those of 50 healthy controls. Then the serum hs-CRP was subjected to evaluation for any correlation with the predictors of outcomes in COPD subjects. Results: Hs-CRP levels were higher in COPD patients than in controls (4.82 vs. 0.88 mg/L p < 0.01). Correlation was found between hs-CRP and the following variables: FEV1 (r= -0.813; p < 0.01), 6MWD (r= -0.876; p < 0.01), body mass index (r= -0.710; p < 0.01), GOLD stage (r= 0.797, p < 0.01) and smoking status (r= 0.796; p < 0.01). Using multivariate analysis, FEV1 and 6MWD showed the strongest negative association with hs-CRP levels. Conclusions: The circulating levels of the inflammatory marker hs-CRP are significantly elevated in patients with COPD, supporting the view that COPD is in part an inflammatory disorder. Hs-CRP levels in stable COPD patients are best correlated with FEV1 and 6-minute walk distance (6MWD). This information should be considered when hs-CRP levels are measured in stable COPD patients.