ORIGINAL ARTICLE Cognitive function in chronic obstructive pulmonary disease: Relationship to global initiative for chronic obstructive lung disease 2011 categories BAYKAL TULEK, 1 NART BEDIN ATALAY, 2 GULFEM YILDIRIM, 1 FIKRET KANAT 1 AND MECIT SÜERDEM 1 1 Department of Chest Diseases, Faculty of Medicine, Selcuk University, Konya and 2 Department of Psychology, TOBB University of Economics & Technology, Ankara, Turkey ABSTRACT Background and objective: Recently, comorbidities such as impaired cognitive function have been attract- ing 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 Initia- tive 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, exac- erbation history and C-reactive protein levels. After controlling for non-COPD predictors, only exacerba- tion history remained a significant predictor of cogni- tive scores. Conclusions: The number of exacerbation events in a year may be used as a predictor of cognitive impair- ment in patients with COPD. Key words: cognitive function, chronic obstructive pulmonary disease, exacerbation, Mini Mental State Examination. Abbreviations: BMI, body mass index; CAT, COPD Assess- ment Test; COPD, chronic obstructive pulmonary disease; CRP, C-reactive protein; DV, dependent variables; FEV1, forced expira- tory volume in 1 s; FVC, forced vital capacity; GOLD, Global Initiative for Chronic Obstructive Lung Disease; MMSE, Mini Mental State Examination; mMRC, modified British Medical Research Council; non-COPD, not related with COPD; OSAS, obstructive sleep apnoea syndrome. INTRODUCTION Chronic obstructive pulmonary disease (COPD) is a heterogenic illness with pulmonary and extra- pulmonary manifestations characterized by chronic airflow limitation. Until recently, the primary diagno- sis and evaluation criteria for COPD were the pres- ence and severity of chronic airflow limitation with forced expiratory volume in 1 s (FEV1). 1 FEV1 has been documented to be an unreliable measure for assess- ing difficulties with breathlessness, limitations in physical activity and impairments of health. 2 Begin- ning with the 2011 Global Initiative for Chronic Obstructive Lung Disease (GOLD), disease impact and exacerbation risk have been considered in the treatment of COPD. Disease impact is assessed by using the COPD Assessment Test (CAT) or the modi- fied British Medical Research Council (mMRC) dysp- noea scale. Exacerbation risk is suggested to be assessed via airflow limitation or exacerbation history. 3 Patient-centred and individualized approaches in managing COPD is becoming more common, and comorbidities are getting more focus in the guide- lines. 4 Despite being associated with decreased daily living activities and difficulty complying with COPD Correspondence: Nart Bedin Atalay, TOBB Ekonomi ve Teknoloji Üniversitesi, Psikoloji Bölümü, Ankara, Turkey. Email: natalay@etu.edu.tr Received 22 December 2013; invited to revise 13 February 2014; revised 1 April 2014; accepted 16 April 2014 (Associate Editor: Bob Hancox). Article first published online: 17 June 2014 SUMMARY AT A GLANCE We assessed the clinical features predictive of cog- nitive impairment in patients with COPD. We recruited 119 mild to severe COPD patients. After controlling for non-COPD predictors, only exacer- bation history remained a significant predictor of cognitive scores. Exacerbations may be used as a predictor of cognitive impairment in patients with COPD. © 2014 Asian Pacific Society of Respirology Respirology (2014) 19, 873–880 doi: 10.1111/resp.12333