A RECENT study by Bina Coit, Division of Pulmonary and Critical Care Medicine at Brigham and Women’s Hospital, Boston, Massachusetts, USA, and colleagues, investigated whether subtle abnormalities in lung tissue, called quantitative interstitial abnormalities (QIA), are linked to acute respiratory disease (ARD) and severe ARD events in people with a smoking history. This study aimed to understand if the progression of QIAs, observed on CT scans, is correlated with the occurrence of these respiratory events.
The prospective study involved individuals with a smoking history of 10 packs/year or more, recruited from various centres between November 2007–July 2017. The team evaluated the progression of QIAs by comparing baseline (visit 1) and 5-year follow-up (visit 2) chest CT scans. ARD episodes were identified as instances of increased cough or dyspnoea lasting 48 hours, necessitating antibiotics or corticosteroids; while severe ARD episodes required emergency room visits or hospitalisations. Data on episodes were collected through questionnaires completed every 3–6 months. Statistical analysis, adjusting for comorbidities such as emphysema and small airway disease, utilised multivariable logistic regression and zero-inflated negative binomial regression models, to explore the relationship between QIA progression and episodes occurring between visits 1 and 2 (intercurrent), and those happening after visit 2 (subsequent).
A total of 3,972 participants, with an average age of 60.7 years, were involved in the study, with over half being females. The study found that the annual percentage increase in QIA was linked to higher odds of experiencing one or more severe ARD events, both during the period between baseline and follow-up, and afterwards. Specifically, individuals in the top quartile of QIA progression (≥1.2%) were more likely to have more frequent intercurrent and severe ARD events compared to those in the lowest quartile (≤-1.7%).
The progression of QIA was found to be independently correlated with an increased likelihood of severe ARD events both during and after radiographic progression. Moreover, individuals experiencing faster progression of QIA tended to have a greater occurrence of severe ARD events during the interim periods between radiographic assessments.
Reference
Choi B et al. Association of acute respiratory disease events with quantitative interstitial abnormality progression at CT in individuals with a history of smoking. Radiology. 2024;311(1):e231801.
