Associations between lung function, sleep quality, cognitive function and quality of life in COPD patients

ABSTRACT Objective: The objective of the study was to investigate the associations between lung function, sleep quality, cognitive function and quality of life in patients with chronic obstructive pulmonary disease (COPD). Materials and Methods: Ten COPD patients (mean age = 71.6 ± 4.55 years; 6 males and 4 females) were assessed for lung function i.e., Forced vital capacity (FVC), forced expiratory volume in 1 s (FEV 1 ), and FEV 1 /FVC (using spirometry before and after bronchodilation), sleep quality (assessed using Pittsburgh Sleep Quality Index), cognitive function (tested using PBHC Cognitive Assessment Questionnaire) and quality of life (measured with SF-36 Health Survey). The Pearson correlation test was used to analyze the relationships between variables. Results: Cognitive functions and sleep quality correlations were near significant (r = 0.593, P = 0.071). No other statistically significant results were observed. Conclusion: Cognitive function tends to decline as sleep quality reduces. Even though this association was close to statistical significance, the conclusions’ strength is limited by the small sample size. To validate these results and to get a better understanding of the relationship between sleep quality and cognition in COPD, more studies with larger sample sizes are required.