Zhu-Quan Su1, Wei-Jie Guan1, Shi-Yue Li1, Jia-Xin Feng1, Zi-Qing Zhou1, Yu Chen1, Ming-Lu Zhong2, Nan-Shan Zhong3. 1. State Key Laboratory of Respiratory Disease, National Clinical Research Center for Respiratory Disease, Guangzhou Institute of Respiratory Health, The First Affiliated Hospital of Guangzhou Medical University, Guangzhou, China. 2. Guangzhou First People's Hospital, Guangzhou, China. 3. State Key Laboratory of Respiratory Disease, National Clinical Research Center for Respiratory Disease, Guangzhou Institute of Respiratory Health, The First Affiliated Hospital of Guangzhou Medical University, Guangzhou, China. Electronic address: nanshan@vip.163.com.
Abstract
BACKGROUND: The anatomic location of small airways, the distribution of airway cartilage, and their correlation with ageing have not been well elucidated. The objective of this article was to explore the morphologic characteristics of small airways in vivo, and how airway structural changes correlate with age using endobronchial optical coherence tomography (EB-OCT). METHODS: We recruited 112 subjects with peripheral pulmonary nodules. Participants underwent CT scan, spirometry, and EB-OCT measurements. We measured the airway internal diameter, the inner area (Ai), the airway wall area percentage (Aw%), and the thickness of airway cartilage. EB-OCT airway structural characteristics at different age intervals were analyzed, and the association between airway morphology and age was evaluated. RESULTS: Of the small airways, 47.3% originated from the seventh generation of bronchi. Cartilage was uniformly present in the third to sixth generation of bronchi, despite a decreasing proportion of cartilage from the seventh to ninth generation of bronchi (92.4%, 54.5%, and 26.8%, respectively). The thickness of airway cartilage progressively decreased with older age. In subjects 40 to 54 years of age, Ai from the third to sixth generation correlated positively with age (r = 0.577, P < .001). Both Ai from the third to sixth generation and Ai from the seventh to ninth generation correlated negatively with age in subjects 55 to 69 years of age (r = -0.374, P = .021 and r = -0.410, P = .011). Aw% from the third to sixth generation and Aw% from the seventh to ninth generation did not correlate significantly with age. CONCLUSIONS: Small airways are mainly located at the seventh generation, where cartilaginous structures are present despite reduced distribution in more distal airways, and the thickness decreased in older age. Reduction in luminal area of medium-to-small airways might be the morphologic changes associated with ageing (ie, > 55 years of age).
BACKGROUND: The anatomic location of small airways, the distribution of airway cartilage, and their correlation with ageing have not been well elucidated. The objective of this article was to explore the morphologic characteristics of small airways in vivo, and how airway structural changes correlate with age using endobronchial optical coherence tomography (EB-OCT). METHODS: We recruited 112 subjects with peripheral pulmonary nodules. Participants underwent CT scan, spirometry, and EB-OCT measurements. We measured the airway internal diameter, the inner area (Ai), the airway wall area percentage (Aw%), and the thickness of airway cartilage. EB-OCT airway structural characteristics at different age intervals were analyzed, and the association between airway morphology and age was evaluated. RESULTS: Of the small airways, 47.3% originated from the seventh generation of bronchi. Cartilage was uniformly present in the third to sixth generation of bronchi, despite a decreasing proportion of cartilage from the seventh to ninth generation of bronchi (92.4%, 54.5%, and 26.8%, respectively). The thickness of airway cartilage progressively decreased with older age. In subjects 40 to 54 years of age, Ai from the third to sixth generation correlated positively with age (r = 0.577, P < .001). Both Ai from the third to sixth generation and Ai from the seventh to ninth generation correlated negatively with age in subjects 55 to 69 years of age (r = -0.374, P = .021 and r = -0.410, P = .011). Aw% from the third to sixth generation and Aw% from the seventh to ninth generation did not correlate significantly with age. CONCLUSIONS: Small airways are mainly located at the seventh generation, where cartilaginous structures are present despite reduced distribution in more distal airways, and the thickness decreased in older age. Reduction in luminal area of medium-to-small airways might be the morphologic changes associated with ageing (ie, > 55 years of age).
Authors: Carli M Peters; Yannick Molgat-Seon; Paolo B Dominelli; Anthony M D Lee; Pierre Lane; Stephen Lam; Andrew W Sheel Journal: Physiol Rep Date: 2021-01