Yeon-Mok Oh 1 , Keu Sung Lee 2 , Yoonki Hong 3 , Sung Chul Hwang 2 , Jae Yeol Kim 4 , Deog Keom Kim 5 , Kwang Ha Yoo 6 , Ji-Hyun Lee 7 , Tae-Hyung Kim 8 , Seong Yong Lim 9 , Chin Kook Rhee 10 , Hyoung Kyu Yoon 11 , Sang Yeub Lee 12 , Yong Bum Park 13 , Jin Hee Jung 14 , Woo Jin Kim 3 , Sang-Do Lee 1 , Joo Hun Park 2
31 October 2018
High blood eosinophil count is a predictive biomarker for response to inhaled corticosteroids in prevention of acute exacerbation of COPD, and low blood eosinophil count is associated with pneumonia risk in COPD patients taking inhaled corticosteroids. However, the prognostic role of blood eosinophil count remains underexplored. Therefore, we investigated the associated factors and mortality based on blood eosinophil count in COPD.
Patients with COPD were recruited from 16 hospitals of the Korean Obstructive Lung Disease cohort (n=395) and COPD in Dusty Area cohort (n=234) of Kangwon University Hospital. The two merged cohorts were divided based on blood eosinophil count into three groups: high (≥5%), middle (2%–5%), and low (<2%).
The high group had longer six-minute walk distance (high =445.8±81.4, middle =428.5±88.0, and low =414.7±86.3 m), higher body mass index (23.3±3.1, 23.1±3.1, and 22.5±3.2 kg/m 2), lower emphysema index (18.5±14.1, 22.2±15.3, and 23.7±16.3), and higher inspiratory capacity/total lung capacity ratio (32.6±7.4, 32.4±9.2, and 29.9% ± 8.9%) ( P<0.05). The survival period increased with increasing blood eosinophil count (high =9.52±0.23, middle =8.47±1.94, and low =7.42±0.27 years, P<0.05). Multivariate linear regression analysis revealed that the emphysema index was independently and negatively correlated with blood eosinophil count ( P<0.05).