CRP and chronic obstructive pulmonary disease: In addition to COPD itself, smoking, which is the generally perceived risk factor for the disease, also contributes to an increase in serum CRP levels. In our study, the increased level of CRP was observed in BODE index stage IV when compared to stages III, II and I respectively (11.34±4.87 mg/L vs. 8.45±2.54, 5.22±1.87 and 3.54±1.21 mg/L; p=0.001).