Determination of the Relationship between Severity of Obstructive Sleep Apnea and Chronic Obstructive Pulmonary Disease

Introduction: Chronic obstructive pulmonary disease (COPD) patients are at increased risk of sleep-disorders. The concomitant occurrence of COPD and obstructive sleep apnea hypopnea syndrome (OSAHS) is named overlap syndrome. This study aimed to evaluate the severity of OSAHS in overlap syndrome patients. Materials & Methods: This cross-sectional study was conducted on adult patients with forced expiratory volume in 1 second (FEV1%)/forced vital capacity<0.7 and obstructive sleep apnea. The patients with left-sided heart failure, cancer, or recent history of sedative or opioid use were excluded from the study. We collected all the data regarding patients’ demographics, body mass index (BMI), neck and waist circumference, stage of COPD (according to Global Initiative for Chronic Obstructive Lung Disease 2012 classification), and polysomnography variables. One-way analysis of variance (ANOVA) was performed using SPSS, version 11. Results: Forty patients (62.5% male) with mean age of 59.7±8.3 years participated in the study. Severity of obstructive sleep apnea was low, moderate, and severe in 23 (57.5%), 14 (35%), and 3 (7.5%) cases, respectively and there was no statistical relation between OSAHS and FEV1% (P=0.55). Conclusion: This study showed that there was no significant correlation between apnea–hypopnea index and FEV1% predicted in overlap syndrome patients.