Daytime sleepiness and quality of sleep in patients with COPD compared to control group

Chronic obstructive pulmonary disease (COPD) is a widespread disease. It produces some night symptoms such as nighttime cough and dyspnea. Then subjective and objective changes in sleep pattern are expected. Present study was conducted to determine frequency of sleepiness and quality of sleep in patients with COPD.

Present case-control study has been performed on 120 patients with diagnosis of COPD who had been referred to pulmonary disease clinic in a University teaching hospital. One hundred twenty age- and sex- matched healthy individuals were recruited in the study and served as control. Spirometry (PFT) was performed for all patients. Patients were categorized under 3 groups in relation to their PFT as follow: mild COPD (FEV1/FVC<70% and >=80%), moderate COPD (FEV1/FVC<70% and 50%<=FEV1<80%), and severe COPD (FEV1/FVC<70% and FEV1<50%). Pittsburgh Sleep Quality questionnaire (PSQI) and Epworth Sleepiness Scale (ESS) were used to estimate quality of sleep and daytime sleepiness in the patients and control group. The collected data were analyzed using version 16 SPSS software. Student's T- test, Chi- square and multiple logistic regressions were used as appropriated.

120 patients with COPD (79 males and 41 females) and 120 normal individuals responded to the questionnaires. Mean scores of quality of sleep were 8.03±3.66 and 4.2±2.8 in COPD patients and control group respectively. 32.1% of the patients had good sleep quality (PSQI score less than 5) and 67.9% had poor sleep quality. Daytime sleepiness (ESS>=10) was present in 34.8% of the patients and 15% of control people. Multiple logistic regressions showed that the patients reported significantly worse sleep quality and more daytime sleepiness than control group [OR=2.9; 95% CI (1.6-3.7) & OR=3.5; 95% CI (2.5-4.3) respectively].

Results of present study confirmed that COPD is associated with daytime sleepiness and poor quality of sleep, possibly attributable to nighttime respiratory difficulties and concomitant sleep apnea. Assessment of the patients for symptoms of sleep apnea, daytime sleepiness should be a part of regular follow up visits of patients with COPD.