Predictive factors warrant screening for obstructive sleep apnea in COPD: a Taiwan National Survey

Liang-Wen Hang,1,2 Jeng-Yuan Hsu,3 Chee-Jen Chang,4 Hao-Chien Wang,5,6 Shih-Lung Cheng,7,8 Ching-Hsiung Lin,9 Ming-Cheng Chan,3 Chin-Chou Wang,10 Diahn-Warng Perng,11 Chong-Jen Yu5,6 On behalf of the Taiwan COPD Consortium 1Department of Respiratory Therapy, College of Health Care, China Medical University, 2Sleep Medicine Center, Department of Pulmonary and Critical Care Medicine, China Medical University Hospital, 3Department of Internal Medicine, Taichung Veterans General Hospital, Taichung, 4Biostatistical Center for Clinical Research, Chang Gung Memorial Hospital, Linkou Branch, Guishan Township, Taoyuan County, 5Department of Internal Medicine, National Taiwan University Hospital, 6Department of Internal Medicine, National Taiwan University, College of Medicine, Taipei, 7Department of Internal Medicine, Far Eastern Memorial Hospital, New Taipei City, 8Department of Chemical Engineering and Materials Science, Yuan Ze University, Chung-Li City, Taoyuan County, 9Division of Chest Medicine, Changhua Christian Hospital, Changhua City, Changhua County, 10Division of Pulmonary and Critical Care Medicine, Kaohsiung Chang Gung Memorial Hospital, Kaohsiung, 11Department of Chest Medicine, Taipei Veterans General Hospital, Taipei, Taiwan, Republic of China Background and objectives: COPD and obstructive sleep apnea (OSA) share similar pathological processes and cardiovascular sequelae. Coexisting OSA in COPD – “overlap syndrome” – has worse prognosis than either condition alone, and appropriate treatment improves survival. Our objectives were to ascertain the frequency at which COPD coexists with the risk of OSA in Taiwan and to compare the risk factors, COPD symptoms, and life quality metrics between COPD subgroups with versus without risk of OSA. Methods: We conducted a random cross-sectional national telephone survey of adults >40 years old in Taiwan. Participants fulfilling an epidemiological case definition of COPD completed a questionnaire to assess COPD symptoms and OSA risk, comorbidities, and performance of daily activities. Data from COPD cohorts with and without risk of OSA were analyzed and compared. Results: Of 6,600 interviews completed, 404 subjects fit the epidemiological case definition of COPD – an overall prevalence of 6.1% in this national sample. Data on OSA risk were available for 292 of this COPD cohort, of whom 29.5% were at risk of OSA. Compared to those without risk of OSA, those with risk of OSA were significantly more likely to have hypertension or cardiovascular disease and diabetes, had significantly higher body mass index and COPD Assessment Test scores, and reported impaired work performance and leisure activities. Conclusion: Among adults in Taiwan who fulfill epidemiologic criteria for COPD, 29.5% have coexisting risk of OSA. Comorbid hypertension or cardiovascular disease and diabetes are common and significantly more prevalent among the COPD population at risk of OSA than those who are not. OSA screening is warranted in patients with COPD with those risk factors that are more prevalent in COPD with risk of OSA than without, to target early interventions to reduce adverse cardiovascular sequelae from overlap syndrome. Keywords: cardiovascular risk, COPD, coexistent, obstructive sleep apnea, OSA, overlap syndrome