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 an accelerated lung function decline.Method: Blood eosinophils were measured in four cohorts:  <45 years old 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/μL) or elevated (≥300 cells/μL). Lung function was measured at baseline and follow-up with spirometry: forced exhaled volume during the first second (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 associated to lower FEV1 (regression coefficient -149mL (95% Confidence Interval: -191; -107), VC (-124mL (-169; -78)) and FEV1/VC (-1.3% (-1.9; -0.7)) at baseline in the two <45 years cohorts, and to lower FEV1 (-79mL (-116; -41)) and FEV1/VC (-1.8% (-2.6; -1.0)) in the two ≥45 years cohorts. Longitudinally, elevated compared to normal blood eosinophils were associated with an excess decline in FEV1 (-5.7mL/year (-11.1; -0.4), V&V <45 years) and VC (-12mL/year (-23.6; -0.9), ECRHS-Uppsala) only in asthmatics.Conclusion: Elevated blood eosinophils are associated with lower lung function in the general population and with an accelerated lung function decline among asthmatics.

Ämnesord

MEDICIN OCH HÄLSOVETENSKAP  -- Klinisk medicin -- Lungmedicin och allergi (hsv//swe)

MEDICAL AND HEALTH SCIENCES  -- Clinical Medicine -- Respiratory Medicine and Allergy (hsv//eng)

Nyckelord

eosinophil

lung function

asthma

Publikations- och innehållstyp

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