Blood Eosinophils and Exacerbations in Chronic Obstructive Pulmonary Disease: The Copenhagen General Population Study

TY - JOUR

T1 - Blood Eosinophils and Exacerbations in Chronic Obstructive Pulmonary Disease

T2 - The Copenhagen General Population Study

AU - Vedel-Krogh, Signe

AU - Nielsen, Sune F

AU - Lange, Peter

AU - Vestbo, Jørgen

AU - Nordestgaard, Børge G

PY - 2016/5/1

Y1 - 2016/5/1

N2 - Rationale: Whether high blood eosinophils are associated with chronic obstructive pulmonary disease (COPD) exacerbations among individuals with COPD in the general population is largely unknown. Objectives: To test the hypothesis that high blood eosinophils predict COPD exacerbations. Methods: 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 (shortcourse 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. Measurements and Main Results: 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 0.34×109 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. Conclusions: Among individuals with COPD in the general population, increased blood eosinophil levels above 0.34×109 cells per liter were associated with a 1.76-fold increased risk of severe exacerbations.

AB - Rationale: Whether high blood eosinophils are associated with chronic obstructive pulmonary disease (COPD) exacerbations among individuals with COPD in the general population is largely unknown. Objectives: To test the hypothesis that high blood eosinophils predict COPD exacerbations. Methods: 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 (shortcourse 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. Measurements and Main Results: 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 0.34×109 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. Conclusions: Among individuals with COPD in the general population, increased blood eosinophil levels above 0.34×109 cells per liter were associated with a 1.76-fold increased risk of severe exacerbations.

U2 - 10.1164/rccm.201509-1869OC

DO - 10.1164/rccm.201509-1869OC

M3 - Journal article

C2 - 26641631

SN - 1073-449X

VL - 193

SP - 965

EP - 974

JO - American Journal of Respiratory and Critical Care Medicine

JF - American Journal of Respiratory and Critical Care Medicine

IS - 9

ER -