Executive dysfunction in COPD: prevalence and clinical correlates of cognitive impairment: A cross-sectional case-control study

Cognitive impairment in chronic obstructive pulmonary disease (COPD) is increasingly recognized, but its clinical correlates remain unclear. This study aimed to assess the prevalence of mild cognitive impairment and dementia in COPD and identify associated clinical factors. In this cross-sectional case-control study, 86 patients with COPD and 61 age- and sex-matched controls aged ≥60 years were evaluated. Cognitive status was assessed using the Mini-Mental State Examination, Montreal Cognitive Assessment, and domain-specific cognitive tests, including the Stroop test. Clinical variables, including spirometric measures, resting oxygen saturation, dyspnea severity, and C-reactive protein, were recorded. Multivariable analysis was performed to evaluate factors associated with Stroop word-reading time. The overall distribution of cognitive status did not differ significantly between groups (P = .228). Mild cognitive impairment was numerically more frequent in the COPD group than in controls (30.2% vs 18.0%), whereas dementia rates were similar. Stroop word-reading time was significantly longer in the COPD group (P < .001). Within the COPD group, poorer cognitive performance was associated with lower resting oxygen saturation and greater dyspnea severity. In multivariable analysis, COPD status remained independently associated with longer Stroop word-reading time after adjustment for age, sex, smoking, C-reactive protein, and body mass index (B = 5.09, P = .004). Although the overall distribution of cognitive status and global cognitive screening scores did not differ significantly between groups, patients with COPD showed longer Stroop word-reading time. Lower resting oxygen saturation and greater dyspnea were associated with poorer cognitive performance within the COPD group. These findings suggest that domain-specific cognitive assessment may provide additional information beyond global cognitive screening; however, prospective studies are needed to confirm the clinical utility of these findings.