Association of High Sensitive CRP Level and COPD Assessment Test Scores with Clinically Important Predictive Outcomes in Stable COPD Patients

BACKGROUND High sensitive CRP (hs-CRP) is used as a marker of systemic inflammation in chronic obstructive pulmonary disease (COPD). However, we hypothesize that the raised hs-CRP is not closely related to the multiple consequences of COPD. This study was undertaken to investigate the association of COPD assessment test (CAT) score with SpO2, FEV1, body mass index (BMI), obstruction, dyspnea and exercise capacity (BODE) index and COPD exacerbation rate and compare it with the association to serum hs-CRP level. MATERIALS AND METHODS Sixty patients with stable COPD referred to the pulmonology clinic of Ardabil Imam Khomeini Hospital were included in this study. SpO2, 6-minute walk distance (6MWD), body mass index, BODE index, and pulmonary function test as well as exacerbation rate were determined in COPD patients. Then, the CAT questionnaire was completed by patients. Serum level of hs-CRP was measured in all patients and 15 controls. We statistically compared the relationships and correlations among the variables. RESULTS Hs-CRP level was significantly raised in patients (P=0.005). In these patients, the correlation of hs-CRP level with BODE index was significant (P=0.008). However, the correlation of hs-CRP with SpO2 and FEV1 was not significant (P=0.47 and P=0.17, respectively). Also, the correlation of CAT score with SpO2, FEV1, BODE index, and exacerbation rate in the previous year was significant (P<0.001, P<0.001, P<0.001 and P=0.017, respectively). CONCLUSION SpO2, FEV1, BODE index and exacerbation rate are more correlated with CAT scores than with the serum level of hs-CRP in stable COPD patients. The findings of this study should be considered in management of stable COPD patients.