Abstract: Objective To know the prevalence of COPD in patients with OSAHS in Kunming Yunnan Province, and the clinical symptom of OS. Methods Retrospective study of 4 636 cases of patients with snoring, excluding COPD in addition to chronic respiratory disease and assess the patient's condition. The test included AHI, BMI, Epworth sleepiness scale, lung function. The index of OS was confirmed by AHI>5 times/h and FEV1/FVC<70%. Results During the period of 2006～2012, the prevalence of COPD in patients with OSAHS was 10.1% (95% confidence interval (CI) 9.1%-11.1%) in Kunming Yunnan Province. And male's OS prevalence rate is higher than the female(male 10.2%; female 9.7%). The OS patients' average age was (56.9±14.1 )years old, the mean AHI was (47.46±26.79) times/h, and the average FEV1/FVC was (60.09±23.57)%. Polysomnography results show that patients suffered obvious hypoxia at night in both only OSAHS group and OS group, but it was more significant in OS group. Pulmonary function test showed that OS patients have more serious chronic obstructive pulmonary disease. Conclusion The prevalence rate of COPD in OSAHS patients was high in Kunming Yunnan Province, and the prevalence rate of age>60 years old group reached more than 24%. In addition, patients with OS were more severe than those with only OSAHS or COPD in lung function and hyoxemia, but the nosogenesis was not clear.

Key words: Obstructive sleep apnea-hypopnea syndrome , Chronic obstructive pulmonary disease, Prevalence, Overlap syndrome