Total Airway Count on Computed Tomography and the Risk of Chronic Obstructive Pulmonary Disease Progression. Findings from a Population-based Study.
Am J Respir Crit Care Med
; 197(1): 56-65, 2018 01 01.
Article
in En
| MEDLINE
| ID: mdl-28886252
ABSTRACT
RATIONALE Studies of excised lungs show that significant airway attrition in the "quiet" zone occurs early in chronic obstructive pulmonary disease (COPD). OBJECTIVES:
To determine if the total number of airways quantified in vivo using computed tomography (CT) reflects early airway-related disease changes and is associated with lung function decline independent of emphysema in COPD.METHODS:
Participants in the multicenter, population-based, longitudinal CanCOLD (Canadian Chronic Obstructive Lung Disease) study underwent inspiratory/expiratory CT at visit 1; spirometry was performed at four visits over 6 years. Emphysema was quantified as the CT inspiratory low-attenuation areas below -950 Hounsfield units. CT total airway count (TAC) was measured as well as airway inner diameter and wall area using anatomically equivalent airways. MEASUREMENTS AND MAINRESULTS:
Participants included never-smokers (n = 286), smokers with normal spirometry at risk for COPD (n = 298), Global Initiative for Chronic Obstructive Lung Disease (GOLD) I COPD (n = 361), and GOLD II COPD (n = 239). TAC was significantly reduced by 19% in both GOLD I and GOLD II compared with never-smokers (P < 0.0001) and by 17% in both GOLD I and GOLD II compared with at-risk participants (P < 0.0001) after adjusting for low-attenuation areas below -950 Hounsfield units. Further analysis revealed parent airways with missing daughter branches had reduced inner diameters (P < 0.0001) and thinner walls (P < 0.0001) compared with those without missing daughter branches. Among all CT measures, TAC had the greatest influence on FEV1 (P < 0.0001), FEV1/FVC (P < 0.0001), and bronchodilator responsiveness (P < 0.0001). TAC was independently associated with lung function decline (FEV1, P = 0.02; FEV1/FVC, P = 0.01).CONCLUSIONS:
TAC may reflect the airway-related disease changes that accumulate in the "quiet" zone in early/mild COPD, indicating that TAC acquired with commercially available software across various CT platforms may be a biomarker to predict accelerated COPD progression.Key words
Full text:
1
Collection:
01-internacional
Database:
MEDLINE
Main subject:
Image Interpretation, Computer-Assisted
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Tomography, X-Ray Computed
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Disease Progression
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Imaging, Three-Dimensional
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Pulmonary Disease, Chronic Obstructive
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Airway Obstruction
Type of study:
Clinical_trials
/
Diagnostic_studies
/
Etiology_studies
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Incidence_studies
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Observational_studies
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Prognostic_studies
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Risk_factors_studies
Limits:
Aged
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Female
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Humans
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Male
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Middle aged
Country/Region as subject:
America do norte
Language:
En
Journal:
Am J Respir Crit Care Med
Journal subject:
TERAPIA INTENSIVA
Year:
2018
Type:
Article
Affiliation country:
Canada