TY - JOUR T1 - Central airway and peripheral lung structures in airway disease-dominant COPD JF - ERJ Open Research JO - erjor DO - 10.1183/23120541.00672-2020 VL - 7 IS - 1 SP - 00672-2020 AU - Naoya Tanabe AU - Kaoruko Shimizu AU - Kunihiko Terada AU - Susumu Sato AU - Masaru Suzuki AU - Hiroshi Shima AU - Akira Oguma AU - Tsuyoshi Oguma AU - Satoshi Konno AU - Masaharu Nishimura AU - Toyohiro Hirai Y1 - 2021/01/01 UR - http://openres.ersjournals.com/content/7/1/00672-2020.abstract N2 - The concept that the small airway is a primary pathological site for all COPD phenotypes has been challenged by recent findings that the disease starts from the central airways in COPD subgroups and that a smaller central airway tree increases COPD risk. This study aimed to examine whether the computed tomography (CT)-based airway disease-dominant (AD) subtype, defined using the central airway dimension, was less associated with small airway dysfunction (SAD) on CT, compared to the emphysema-dominant (ED) subtype.COPD patients were categorised into mild, AD, ED and mixed groups based on wall area per cent (WA%) of the segmental airways and low attenuation volume per cent in the Kyoto–Himeji (n=189) and Hokkaido COPD cohorts (n=93). The volume per cent of SAD regions (SAD%) was obtained by nonrigidly registering inspiratory and expiratory CT.The AD group had a lower SAD% than the ED group and similar SAD% to the mild group. The AD group had a smaller lumen size of airways proximal to the segmental airways and more frequent asthma history before age 40 years than the ED group. In multivariable analyses, while the AD and ED groups were similarly associated with greater airflow limitation, the ED, but not the AD, group was associated with greater SAD%, whereas the AD, but not the ED, group was associated with a smaller central airway size.The CT-based AD COPD subtype might be associated with a smaller central airway tree and asthma history, but not with peripheral lung pathologies including small airway disease, unlike the ED subtype.This study shows that airway disease-dominant COPD, defined using central airway dimension on CT, is associated with a smaller central airway tree, less small airway dysfunction and slower lung function decline than the emphysema-dominant COPD https://bit.ly/3nNwxIC ER -