LOW-GRADE SYSTEMIC INFLAMMATION IN PATIENTS WITH STABLE CHRONIC OBSTRUCTIVE PULMONARY DISEASE

Abstract

Introduction: Chronic obstructive pulmonary disease (COPD) is a multicomponent disease with extrapulmonary effects. Systemic aspects of COPD include oxidative stress and altered circulating levels of inflammatory mediators and acute-phase proteins. Airflow limitation is associated with an abnormal inflammatory response mainly initiated by smoke inhalation. Even though chronic inflammation is a characteristic phenomenon of the disease, so far little is known about underlying pathogenetic mechanisms. Aim: To evaluate circulating C-reactive protein (CRP) level as a biomarker of systemic inflammation, leukocyte count, lipid profile and smoking exposure in patients with stable COPD and their correlation with the severity of the disease. Material and methods: Cross sectional study was conducted at 60 patients with COPD (age 40-75) and 30 subjects from general population without COPD, matched by age, gender and body mass index. All patients underwent laboratory testing and pulmonary function tests. The severity level in patients with COPD was determined according to GOLD (Global Initiative for Chronic Obstructive Lung Disease) criteria. Results: We found statistically significant difference between mean serum CRP level in stable COPD than control group (10.2 vs. 5.9, P = 0.04, P< 0.05). The Pearson correlation between leukocytes count and CRP value in stable COPD patients, compared to control group, showed statistically significant correlation (r=0.358, P=0.005, P < 0.01). According to lipid profile, comparison was made between mean values of total cholesterol, triglycerides, low-density lipoprotein (LDL) and high-density lipoprotein (HDL) in both groups, but statistically significant difference was not found. Number of patients with leukocyte count >109/L was significantly higher in stable COPD than control group (45% vs. 26.7%, P= 0.01, P < 0.05). The degree of airflow limitation in COPD patients was significantly related to smoking exposure expressed by number of pack-years (Brinkman Index), Pearson correlation, (r= -0.525, P=0.000, P < 0.01), as well as to the serum CRP level (r= -0.324, P=0.012, P < 0.05). Conclusion: The present study confirms that circulating CRP levels and total leukocyte count are higher in stable COPD patients. Serum CRP may be regarded as a valid biomarker of low-grade systemic inflammation which is the leading point to atherosclerosis.