Akinci B, et al. - An objective assessment of chronic obstructive pulmonary disease (COPD) patients with and without Obstructive Sleep Apnea (OSA) was carried out in order to explore links between sleep quality, daytime sleepiness, and quality of life in those with moderate to very severe disease. Also, in both group of patients, sleep quality, quality of life and daytime sleepiness were compared. Poor sleep quality exerting a negative impact on the quality of life, was observed among COPD patients regardless of OSA. Additionally, data revealed that COPD and OSA association caused worsened vitality in terms of health-related quality of life.