Asthma and lung structure on computed tomography: the Multi-Ethnic Study of Atherosclerosis Lung Study.

BACKGROUND: The potential consequences of asthma in childhood and young adulthood on lung structure in older adults have not been studied in a large, population-based cohort.
OBJECTIVE: The authors hypothesized that a history of asthma onset in childhood (age 18 years or before) or young adulthood (age 19-45 years) was associated with altered lung structure on computed tomography in later life.
METHODS: The Multi-Ethnic Study of Atherosclerosis Lung Study recruited 3965 participants and assessed asthma history by using standardized questionnaires, guideline-based spirometry, and segmental airway dimensions and percentage of low attenuation area (%LAA) on computed tomographic scans.
RESULTS: Asthma with onset in childhood and young adulthood was associated with large decrements in FEV(1) among participants with a mean age of 66 years (-365 mL and -343 mL, respectively; P < .001). Asthma with onset in childhood and young adulthood was associated with increased mean airway wall thickness standardized to an internal perimeter of 10 mm (0.1 mm, P < .001 for both), predominantly from narrower segmental airway lumens (-0.39 mm and -0.34 mm, respectively; P < .001). Asthma with onset in childhood and young adulthood also was associated with a greater %LAA (1.69% and 4.30%, respectively; P < .001). Findings were similar among never smokers, except that differential %LAA in childhood-onset asthma were not seen in them.
CONCLUSION: Asthma with onset in childhood or young adulthood was associated with reduced lung function, narrower airways, and among asthmatic patients who smoked, greater %LAA in later life.