Inflammatory Markers and the Risk of Chronic Obstructive Pulmonary Disease: A Systematic Review and Meta-Analysis
BACKGROUND Fibrinogen is a marker of systemic inflammation and may be important in the pathogenesis and progression of chronic obstructive pulmonary disease (COPD). METHODS We used baseline data from Atherosclerosis Risk in Communities and Cardiovascular Health Studies to determine the relation between fibrinogen levels and COPD and to examine how fibrinogen levels at baseline affected outcomes of death, development of COPD, lung function decline, and COPD-hospitalizations. RESULTS Our study sample included 20,192 subjects, of whom 2995 died during the follow-up period. The mean fibrinogen level was 307.6 mg/dL and 10% of the sample had levels >393.0 mg/dL. Subjects with Stage 3 or 4 COPD were more likely to have a fibrinogen level >393.0 mg/dL (odds ratio 2.28, 95% confidence interval [CI]: 1.79-2.95). In the longitudinal adjusted models, fibrinogen levels >393 mg/dL predicted mortality (hazards ratio 1.54, 95% CI: 1.39-1.70), COPD-related hospitalization (hazards ratio 1.45, 95% CI: 1.27-1.67), and incident Stage 2 COPD (odds ratio 1.36, 95% CI: 1.07-1.74). Similar findings were seen with continuous fibrinogen levels. CONCLUSION In the Atherosclerosis Risk in Communities/Cardiovascular Health Studies cohort data, higher fibrinogen levels are predictors of mortality, COPD-related hospitalizations, and incident Stage 2 COPD.