Impaired Respiratory System Resistance and Reactance Are Associated With Bronchial Wall Thickening in Persistent Asthma.

Abstract

A recent study demonstrated a significant correlation between bronchial biopsy airway remodeling and quantitative computed tomography looking at bronchial wall thickness. To identify clinical associations with bronchial wall thickness in moderate to severe asthma. Ninety-two respiratory physician-diagnosed Global Initiative for Asthma-defined patients with moderate to severe asthma were included in this retrospective cohort study. Blinded to all clinical data, 2 senior thoracic radiologists independently measured airway lumen and total airway area at 4 different bronchopulmonary segments using high-resolution computed tomography imaging. We calculated adjusted odds ratios with regard to the association of bronchial wall thickness with spirometry, oscillometry, exacerbations, and nasal polyps. The pooled analysis for all 4 bronchopulmonary segments showed that an area under reactance curve greater than or equal to 1.0 kPa/L, an R5-R20 ratio (resistance heterogeneity between 5 and 20 Hz divided by total resistance [R5]) of 25% or more, having 2 or more exacerbations per year, and presence of nasal polyposis exhibited adjusted odds ratios of 3.54 (95% CI, 1.22-10.32), 2.89 (95% CI, 1.03-8.05), 4.17 (95% CI, 1.25-13.90), and 9.85 (95% CI, 2.33-41.74), respectively, in their association with a wall area thickness of 50% or more. These translated into a respective 72%, 65%, 76%, and 90% increased likelihood for a wall area thickness of 50% or more. Bronchial wall thickness is associated with peripheral airways resistance and reactance, severe exacerbations, and nasal polyposis in persistent asthma.