The presence of emphysema on chest imaging and mid-life cognition

Abstract

BackgroundAirflow obstruction is associated with cognitive dysfunction, but studies have not assessed how emphysema, a structural phenotype of lung disease, might be associated with cognitive function independent from pulmonary function measured by spirometry. We aimed to determine the relationship between the presence of visually detectable emphysema on chest CT imaging and cognitive function.MethodsWe examined 2491 participants, mean age of 50 years, from the CARDIA (Coronary Artery Risk Development in Young Adults) study who were assessed for the presence of emphysema on chest CT imaging and had cognitive function measured 5 years later with a battery of 6 cognitive tests.ResultsOf those assessed, 172 (7%) had emphysema. After adjusting for age, sex, height, study center, race, body mass index, education, and smoking, visual emphysema was significantly associated with worse performance on most cognitive tests. Compared to those without emphysema, participants with emphysema performed worse on cognitive testing: 0.39 sd units lower (95% CI: −0.53 to −0.25) Montreal Cognitive Assessment, 0.27 sd units lower (95% CI: −0.42 to −0.12) Rey Auditory Verbal Learning Test, 0.29 sd units lower (95% CI: −0.43 to −0.14) Digit Symbol Substitution Test, and 0.25 sd units lower (95% CI: −0.42 to −0.09) letter fluency. Further adjustment for FEV1, peak FEV1, and annualised FEV1 decline did not attenuate these associations.ConclusionsThe presence of emphysema on chest CT is associated with worse cognitive function, independent of airflow obstruction. These data suggest that emphysema may be a novel risk factor for cognitive impairment.