Prevalence and determinants of cognitive impairment in COPD patients enrolled for Pulmonary Rehabilitation

Background: Cognitive impairment (CI) is a prevalent extrapulmonary manifestation in COPD. We assessed the prevalence and the determinants of CI in COPD. Method: 52 COPD patients (aged: 68±8yrs; FEV 1 : 45±14%; 40%women) underwent a comprehensive cognitive assessment. Patients were assigned to “CI” and “non-CI” groups according to Montreal Cognitive Assessment (MoCA) cutoff score ≤25points. Clinical data including medical history, respiratory function, health/ mood status evaluation by Saint-George respiratory questionnaire (SGRQ) and hospital anxiety-depression scale (HADS) were collected. Patients performed six-minute walk test (6MWT) and cycle endurance test (CET) at 75% of peak work rate. Results: 23 patients (44%) presented evidences of CI (MoCA≤25) with also lower scores in the other cognitive tests (all p 1 %, health and mood status (SGRQ, HADS), and exercise capacity (6MWD: 359 ±85m vs 380 ±116m, p=0.48; CET: 616 ±329sec vs 551 ±370sec, p=0.51) but greater oxygen desaturation during the CET (SpO 2 nadir: 92.3 ±2.9% vs 89.9 ±3.9%, p=0.014). Certain threshold of SpO 2 nadir (≤90%) increased the risk for CI after adjustment for oxygen-use (p=0.026). Conclusion: CI is highly prevalent in patients with COPD and affects several cognitive domains. It is associated with the years of education and the oxygen desaturation during the CET, however, it seems that is not associated with exercise capacity in COPD patients.