Central airway collapse is related to obesity independent of asthma phenotype

ABSTRACT Background and objective Late‐onset non‐allergic asthma in obesity is characterized by an abnormally compliant, collapsible lung periphery; it is not known whether this abnormality exists in proximal airways. We sought to compare collapsibility of central airways between lean and obese individuals with and without asthma. Methods A cross‐sectional study comparing luminal area and shape (circularity) of the trachea, left mainstem bronchus, right bronchus intermedius and right inferior lobar bronchus at RV and TLC by CT was conducted. Results In 11 lean controls (BMI: 22.4 (21.5, 23.8) kg/m2), 10 lean individuals with asthma (23.6 (22.0, 24.8) kg/m2), 10 obese controls (45.5 (40.3, 48.5) kg/m2) and 21 obese individuals with asthma (39.2 (35.8, 42.9) kg/m2), lumen area and circularity increased significantly with an increase in lung volume from RV to TLC for all four airways (P