Blood eosinophil level and lung function trajectories : cross-sectional and longitudinal studies in European cohorts

Background: Elevated blood eosinophils have been associated with lower lung function and are believed to be associated with accelerated lung function decline. Method: Blood eosinophils were measured in four cohorts: <45 years cohort within the Vlagtwedde-Vlaardingen (V&V) study, the Uppsala cohort of the European Community Respiratory Health Survey (ECRHS-Uppsala; <45 years), >= 45 years cohort within the V&V study, and the Rotterdam study (.45 years). Blood eosinophils at baseline were classified as normal (<300 cells.mu L-1) or elevated (>= 300 cells.mu L-1). Lung function was measured at baseline and follow-up with spirometry: forced expiratory volume in 1 s (FEV1), vital capacity (VC) and their ratio FEV1/VC. The association between blood eosinophils and lung function was tested cross-sectionally using linear regression and longitudinally using a mixed model, both adjusted for age, sex, height, pack-years smoking and smoking status. Stratified analyses were done for asthma. Results: Elevated blood eosinophils were associated with lower FEV1 (regression coefficient -147 mL (95% CI -188 to -105 mL)), VC (-120 mL (-165 to -75 mL)) and FEV1/VC (-1.3% (-1.9% to -0.6%)) at baseline in the two <45 years cohorts, and with lower FEV1 (-70 mL (-112 to -27 mL)) and FEV1/VC (-1.8% (-2.6% to -1.0%)) in the two.45 years cohorts. Elevated blood eosinophils were associated with an accelerated decline in FEV1 (-5.5 mL.year(-1) (95% CI -10.5 to -0.5 mL.year(-1))) and VC (-6.4 mL.year(-1) (-11.26 to -1.5 mL.year(-1))) compared to normal blood eosinophils in the younger asthmatic subjects in the longitudinal studies. Conclusion: Elevated blood eosinophils are associated with lower lung function in the general population and with an accelerated lung function decline among asthmatic individuals.

Jaar van publicatie:2020

Toegankelijkheid:Open