Effects of COPD on cognitive functions: a case control study

Assessment of disease severity, effects of disease on health status and future events should be considered to direct treatment strategies in chronic obstructive pulmonary disease (COPD) management. Although extrapulmonary effects of COPD are well known, effects of COPD on cognitive functions have not been evaluated sufficiently. therefore we aimed to determine cognitive functions of copd patients in the present study. 112 COPD patients with moderate, severe and very severe irreversible airway obstruction and 44 age matched healthy subjects without COPD and systemic diseases as control group were enrolled to the study. Mini mental state examination (MMSE) was performed to evaluate cognitive functions. MMSE results were compared between patient and control groups. Moreover relationship between exacerbation frequency and cognitive functions was evaluated. Total 156 subjects as 112 COPD patients and 44 healthy subjects were included to the study. Mean age of COPD patients was 65.03 ± 7.63 years, and mean age of control group was 63.63 ± 8.96 years (p= 0.364). Mean score of MMSE in COPD patients was 23.8 ± 4.39, and mean score of MMSE in control group was 26.7 ± 2.88. We determined a significant difference in terms of MMSE scores betweeen patient and control group (p< 0.0001). MMSE scores and FEV1 values were significantly different among patients with moderate, sevre and very severe airflow obstruction (p= 0.001; p< 0.0001 respectively). We found a significant negative correlation between MMSE results and exacerbation frequency during last year (p= 0.003; r= -0.239). Lower MMSE scores of COPD patients than subjects in control group indicates the impairment of cognitive functions in COPD patients. Moreover a negative relationship between MMSE scores with exacerbation frequency during last year suggests that prevention from exacerbation can decrease cognitive impairment in COPD patients. We believe that assessment of cognitive functions and preventive strategies should be considered in COPD management.