title: Blood Eosinophils and Exacerbations in Chronic Obstructive Pulmonary Disease. The Copenhagen General Population Study.
abstract: Whether high blood eosinophils are associated with chronic obstructive pulmonary disease (COPD) exacerbations among individuals with COPD in the general population is largely unknown.
  
  
  
  To test the hypothesis that high blood eosinophils predict COPD exacerbations.
  
  
  
  Among 81,668 individuals in the Copenhagen General Population Study, we examined 7,225 with COPD based on spirometry. We recorded blood eosinophils at baseline and future COPD exacerbations longitudinally, defined as moderate (short-course treatment with systemic corticosteroids) or severe (hospitalization). We also assessed exacerbation risk in a subgroup of 203 individuals with clinical COPD, defined as participants with a smoking history of at least 10 pack-years, FEV1 less than 70% of predicted value, and at least one moderate or severe exacerbation in the year before baseline.
  
  
  
  During a median of 3.3 years of follow-up (range, 0.03-8.1), 1,439 severe and 2,864 moderate COPD exacerbations were recorded. Among all participants with COPD, blood eosinophils above versus below 0.34 × 10(9) cells per liter had multivariable-adjusted incidence rate ratios of 1.76 (95% confidence interval, 1.56-1.99) for severe exacerbations and 1.15 (1.05-1.27) for moderate exacerbations. Corresponding values in those with clinical COPD were 3.21 (2.49-4.14) and 1.69 (1.40-2.04). In contrast, using a cutpoint of 2% for blood eosinophils, the risk of exacerbations was increased for severe exacerbations only among individuals with clinical COPD and not in individuals in the broader population.
  
  
  
  Among individuals with COPD in the general population, increased blood eosinophil levels above 0.34 × 10(9) cells per liter were associated with a 1.76-fold increased risk of severe exacerbations.
authors.affiliation: 1 Department of Clinical Biochemistry, Herlev and Gentofte Hospital.|3 The Copenhagen General Population Study, Herlev and Gentofte Hospital, and.|2 Faculty of Health and Medical Sciences and.
authors.forename: Signe
authors.initials: S
authors.lastname: Vedel-Krogh
authors.affiliation: 1 Department of Clinical Biochemistry, Herlev and Gentofte Hospital.|3 The Copenhagen General Population Study, Herlev and Gentofte Hospital, and.|2 Faculty of Health and Medical Sciences and.
authors.forename: Sune F
authors.initials: SF
authors.lastname: Nielsen
authors.affiliation: 3 The Copenhagen General Population Study, Herlev and Gentofte Hospital, and.|5 Medical Unit, Respiratory Section, Hvidovre Hospital, Copenhagen University Hospital, Copenhagen, Denmark.|4 Section of Social Medicine, Department of Public Health, University of Copenhagen, Copenhagen, Denmark; and.
authors.forename: Peter
authors.initials: P
authors.lastname: Lange
authors.affiliation: 6 Centre for Respiratory Medicine and Allergy, The University of Manchester and University Hospital South Manchester NHS Foundation Trust, Manchester, United Kingdom.
authors.forename: Jørgen
authors.initials: J
authors.lastname: Vestbo
authors.affiliation: 1 Department of Clinical Biochemistry, Herlev and Gentofte Hospital.|3 The Copenhagen General Population Study, Herlev and Gentofte Hospital, and.|2 Faculty of Health and Medical Sciences and.
authors.forename: Børge G
authors.initials: BG
authors.lastname: Nordestgaard
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D003718:Denmark; D004804:Eosinophils; D005260:Female; D005541:Forced Expiratory Volume; D006801:Humans; D008137:Longitudinal Studies; D008297:Male; D008875:Middle Aged; D011446:Prospective Studies; D029424:Pulmonary Disease, Chronic Obstructive / Q000097:blood*; D018570:Risk Assessment; D012720:Severity of Illness Index; D013147:Spirometry; D055815:Young Adult
keywords: epidemiology; granulocytes; lung disease; prospective study