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Imaging-based clusters in current smokers of the COPD cohort associate with clinical characteristics: the SubPopulations and Intermediate Outcome Measures in COPD Study (SPIROMICS)
Journal article   Open access   Peer reviewed

Imaging-based clusters in current smokers of the COPD cohort associate with clinical characteristics: the SubPopulations and Intermediate Outcome Measures in COPD Study (SPIROMICS)

Babak Haghighi, Sanghun Choi, Jiwoong Choi, Eric A Hoffman, Alejandro P Comellas, John D Jr Newell, R. Graham Barr, Eugene Bleecker, Christopher B Cooper, David Couper, …
Respiratory research, Vol.19(1), pp.178-178
09/18/2018
DOI: 10.1186/s12931-018-0888-7
PMCID: PMC6145340
PMID: 30227877
url
https://doi.org/10.1186/s12931-018-0888-7View
Published (Version of record) Open Access

Abstract

Classification of COPD is usually based on the severity of airflow, which may not sensitively differentiate subpopulations. Using a multiscale imaging-based cluster analysis (MICA), we aim to identify subpopulations for current smokers with COPD. Among the SPIROMICS subjects, we analyzed computed tomography images at total lung capacity (TLC) and residual volume (RV) of 284 current smokers. Functional variables were derived from registration of TLC and RV images, e.g. functional small airways disease (fSAD%). Structural variables were assessed at TLC images, e.g. emphysema and airway wall thickness and diameter. We employed an unsupervised method for clustering. Four clusters were identified. Cluster 1 had relatively normal airway structures; Cluster 2 had an increase of fSAD% and wall thickness; Cluster 3 exhibited a further increase of fSAD% but a decrease of wall thickness and airway diameter; Cluster 4 had a significant increase of fSAD% and emphysema. Clinically, Cluster 1 showed normal FEV1/FVC and low exacerbations. Cluster 4 showed relatively low FEV1/FVC and high exacerbations. While Cluster 2 and Cluster 3 showed similar exacerbations, Cluster 2 had the highest BMI among all clusters. Association of imaging-based clusters with existing clinical metrics suggests the sensitivity of MICA in differentiating subpopulations.
Adult Aged Cluster Analysis Cohort Studies Cross-Sectional Studies Female Forced Expiratory Volume - physiology Humans Male Middle Aged Outcome Assessment, Health Care - methods Pulmonary Disease, Chronic Obstructive - diagnostic imaging Pulmonary Disease, Chronic Obstructive - physiopathology Smokers Tomography, X-Ray Computed - methods

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