Airway wall thickness and PRISm are associated with cognitive impairment in individuals with cigarette smoking exposure

Abstract

Abstract Background Individuals with chronic obstructive pulmonary disease (COPD) and cigarette smoking exposure are at increased risk of cognitive impairment; however, the clinical characteristics of those at risk are incompletely understood. Methods We conducted a secondary analysis of COPDGene cohort data to identify clinical characteristics, particularly pulmonary function and lung CT metrics, associated with cognitive impairment. Cognitive items available from Phase 3 included: self-report of a cognitive disorder diagnosis and cognitive difficulties, and probable cognitive impairment (pCI) defined by Mini-Cog ≤ 3. Thirty-seven variables were considered for inclusion in a mixed effects logistic regression with pCI as the dependent variable including demographics, smoking history, medical history, symptom severity, pulmonary function testing, and COPD-related lung CT variables. Results Among 2,079 participants (mean age = 68.7[SD ± 8.6] years, 51.2% female, 28.7% African American), the frequency of pCI differed by smoking/COPD severity group (9.4% never smokers, 18.7% smoking history-normal spirometry, 30.0% preserved ratio impaired spirometry [PRISm], 26.3% GOLD 1–4; p < 0.001). Older age, male sex, lower education, African American race, lower body mass index, higher anxiety symptoms, and CT metrics (higher Perc15 and Pi10) were associated with pCI in the final model. Conclusions Just under thirty percent of participants with smoking exposure and evidence of lung disease on spirometry (PRISm or GOLD 1–4) had pCI, with the highest frequency in PRISm and advanced COPD. Several demographic and clinical characteristics were associated with pCI including airway disease measured via Pi10 on lung CT pointing to a potential link between specific COPD-related physiology and cognitive impairment.