Association between C-reactive Protein Concentration and Chronic Obstructive Pulmonary Disease: a Systematic Review and Meta-analysis

OBJECTIVE: This meta-analysis was conducted to summarize the association between the serum concentration of C-reactive protein (CRP) and chronic obstructive pulmonary disease (COPD). METHODS: MEDLINE (R), Cochrane Central Register of Controlled Trials, and EMBASE databases were searched for relevant studies. Data were extracted; pooled weighted mean differences (WMDs) and 95% confidence intervals (CIs) were calculated. RESULTS: Twenty studies were selected for final inclusion in this analysis. Patients with COPD had higher serum CRP concentrations than healthy controls (WMD 4.72 mg/l, 95% CI 2.98, 6.47). In addition, patients with severe COPD had higher serum CRP concentrations than those with moderate COPD (WMD 1.26 mg/l, 95% CI 0.78, 1.73). There was no significant difference in serum CRP concentration between patients with mild and moderate COPD (WMD 0.67 mg/l, 95% CI -0.08, 1.42). CONCLUSIONS: This meta-analysis suggested that patients with stable COPD had higher serum CRP concentrations than healthy controls. CRP might be an indicator of disease severity in patients with COPD, thus highlighting the importance of measuring serum CRP concentrations in patients with stable COPD.