Systemic Inflammation in Patients with Chronic Obstructive Pulmonary Disease: Results from the Cosmic Study

Objective: The study aims to elucidate the association of host-related factors on systemic inflammation in COPD patients. Methods: In 295 clinically stable and optimally treated COPD patients from 39 outpatient centers, age, gender, and body composition (body mass index, BMI; fat-free mass index, FFMI; fat mass index, FMI) were related to inflammatory biomarkers: CRP, fibrinogen, TNFα, and its soluble receptors (s)TNFαR1 and sTNFαR2. Furthermore, forced expiratory volume in the first second (FEV1), BMI, FFMI, and FMI were stratified by quartiles to elucidate the influence on inflammatory biomarkers. Monovariate and multivariate regression analyses were performed for associations between inflammatory biomarkers. Results: Positive correlations were found for FFMI with sTNFαR1, FMI with CRP and age with TNFα, sTNFαR1 and sTNFαR2 (p < 0.01). FEV1 was not correlated with body composition and inflammatory markers. Mono- and multivariate analysis showed weak correlations between the acute phase markers and the TNFα system after correcting for multiple co-variants. Conclusions: This study highlights the modest role of age and body composition on levels of systemic inflammatory biomarkers in COPD. Results show the degree of airflow limitation does not affect systemic inflammation. Last, a weak relationship between acute phase markers and markers of the TNFα system is present in COPD.