Elevated plasma fibrinogen associated with reduced pulmonary function and increased risk of chronic obstructive pulmonary disease

We tested whether increased concentrations of the acute-phase reactant fibr inogen correlate with pulmonary function and rate of chronic obstructive pu lmonary disease (COPD) hospitalization. We measured plasma fibrinogen and f orced expiratory volume in 1 s (FEV1), and assessed prospectively COPD hosp italizations in 8,955 adults from the Danish general population. Smokers wi th plasma fibrinogen in the upper and middle tertile (>3.3 and 2.7-3.3 g/L) had 7% (95% confidence interval [CI]: 5-8%) and 2% (0-3%) lower percentage predicted FEV1 than smokers with fibrinogen in the lower tertile (<2.7 g/L ). The equivalent decreases in nonsmokers were 6% (4-7%) and 0% (-1-2%), re spectively. Individuals with plasma fibrinogen in the upper and middle tert ile had COPD hospitalization rates of 93 and 60 compared with 52 per 10,000 person-years in individuals with fibrinogen in the lower tertile (log-rank : p < 0.001 and p = 0.31). After adjusting for age, body mass index, sex, p ack-years, and recent respiratory infections, relative risks for COPD hospi talization were 1.7 (95% Cl: 1.1-2.6) and 1.4 (0.9-2.1) in individuals with fibrinogen in the upper and middle versus lower tertile. In conclusion, el evated plasma fibrinogen was associated with reduced FEV1 and increased ris k of COPD. This could not be explained by smoking alone.