Quantitative CT Evidence of Airway Inflammation in WTC Workers and Volunteers with Low FVC Spirometric Pattern

• Published in: Lung Vol. 198; no. 3; pp. 555 - 563
• Main Authors: Weber, Jonathan, Reeves, Anthony P., Doucette, John T., Jeon, Yunho, Sood, Akshay, San José Estépar, Raúl, Celedón, Juan C., de la Hoz, Rafael E.
• Format: Journal Article
• Language: English
• Published: New York Springer US 01.06.2020; Springer; Springer Nature B.V
• Subjects: Airway management; Attenuation; Care and treatment; Chronic obstructive pulmonary disease; Diagnosis; Emphysema; Emphysema, Pulmonary; Forced expiratory volume; Inflammation; Lungs; Medicine; Medicine & Public Health; Minority & ethnic groups; Obesity; Observations; Occupational diseases; Pneumology/Respiratory System; Regression analysis; Regression models; Respiration; Respiratory tract; Respiratory tract diseases; Smoking; Subgroups; World Trade Center Related Lung Disease; United States; Smoke inhalation injury; World Trade Center attack 2001; Obesity; Spirometry; Bronchial diseases; Computer assisted image processing; Forced vital capacity; Obstructive airway disease; Occupational airways and lung diseases; Multidetector computed tomography
• ISSN: 0341-2040; 1432-1750
• DOI: 10.1007/s00408-020-00350-5

Background The most common abnormal spirometric pattern reported in WTC worker and volunteer cohorts has consistently been that of a nonobstructive reduced forced vital capacity (low FVC). Low FVC is associated with obesity, which is highly prevalent in these cohorts. We used quantitative CT (QCT) to investigate proximal and distal airway inflammation and emphysema in participants with stable low FVC pattern. Methods We selected study participants with at least two available longitudinal surveillance spirometries, and a chest CT with QCT measurements of proximal airway inflammation (wall area percent, WAP), end-expiratory air trapping, suggestive of distal airway obstruction (expiratory to inspiratory mean lung attenuation ratio, MLA EI ), and emphysema (percentage of lung volume with attenuation below − 950 HU, LAV%). The comparison groups in multinomial logistic regression models were participants with consistently normal spirometries, and participants with stable fixed obstruction (COPD). Results Compared to normal spirometry participants, and after adjusting for age, sex, race/ethnicity, BMI, smoking, and early arrival at the WTC disaster site, low FVC participants had higher WAP (OR adj 1.24, 95% CI 1.06, 1.45, per 5% unit), suggestive of proximal airway inflammation, but did not differ in MLA EI , or LAV%. COPD participants did not differ in WAP with the low FVC ones and were more likely to have higher MLA EI or LAV% than the other two subgroups. Discussion WTC workers with spirometric low FVC have higher QCT-measured WAP compared to those with normal spirometries, but did not differ in distal airway and emphysema measurements, independently of obesity, smoking, and other covariates.