Cognitive function in chronic obstructive pulmonary disease: Relationship to global initiative for chronic obstructive lung disease 2011 categories

Background and objective: Recently, comorbidities such as impaired cognitive function have been attracting more focus when considering the management of chronic obstructive pulmonary disease (COPD). Here we investigated the relationship between cognitive function and the categories given in the Global Initiative for Chronic Obstructive Lung Disease (GOLD) guidelines in 2011. Specifically, after controlling for non-COPD covariates, we assessed the clinical features that may be predictive of cognitive impairment in patients with COPD. Methods: We recruited 119 stable patients with mild to very severe COPD. We administered a broad array of standardized neuropsychological tests that assessed cognitive functions in the domains of attention, memory, psychomotor coordination and language. Results: Cognitive scores were significantly different between patients falling within GOLD 2011 categories. Scores were lower in patients with high future risk compared with low future risk. In parallel, there were significant differences in cognitive function between COPD patient subgroups when patients were grouped according to the forced expiratory volume in 1 s, exacerbation history and C-reactive protein levels. After controlling for non-COPD predictors, only exacerbation history remained a significant predictor of cognitive scores. Conclusions: The number of exacerbation events in a year may be used as a predictor of cognitive impairment in patients with COPD.