Background: The relationship between plasma markers of inflammation and incidence of chronic obstructive pulmonary disease (COPD) is still unclear. This population-based study explored whether elevated levels of five inflammation-sensitive plasma proteins (ISPs) predicted COPD hospitalizations during 25 years of follow-up.
Methods: Spirometry and measurements of five ISPs (fibrinogen, ceruloplasmin, α1-antitrypsin, haptoglobin, orosomucoid) was performed in 5247 apparently healthy men from the city of Malmö (mean age 46 years). Incidence of hospitalizations due to COPD was studied in relation to the number of ISPs in the 4th quartile.
Results: During the follow-up, 258 men were hospitalized due to COPD, 211 of them were smokers at baseline. Incidence of COPD hospitalizations was significantly associated with the number of elevated ISPs. Adjusted for risk factors, the hazards ratio (95% CI) was 1.00 (reference), 1.28 (0.9-1.9), 1.29 (0.8-2.0) and 2.30 (1.6-3.2), respectively, for men with none, one, two and three or more ISPs in the top quartile (p for trend<0.001). This relationship was consistent both in men with high and low lung function at baseline. The relationship with incidence of COPD hospitalizations was largely the same for all individual ISPs.
Conclusion: Elevated ISP levels in plasma are associated with increased incidence of COPD requiring hospitalization.