Abstract: Objective To explore the related factors of obstructive sleep apnea-hypopnea syndrome(OSAHS)complicated by chronic obstructive pulmonary disease(COPD),so as to provide reference for the improvement of clinical prognosis and disease control. Methods All 266 cases of OSAHS patients in our hospital between February,2011 and March,2014 were enrolled,and were divided into OSAHS group(n=186)and overlap syndrome group(n=80)according to complication of COPD.The gender,age,BMI values,medical grading of OSAHS,smoking,primary hypertension,coronary heart disease,diabetes,renal dysfunction and cerebral vascular disease in both groups were recorded and analyzed.The lung function parameters(FEV₁/FVC,FEV₁)and arterial blood gas analysis(PaCO₂,PaO₂)were compared. Results Univariate analysis showed that the difference in age,BMI,lung function,arterial blood gas analysis,medical grading of OSAHS,smoking,hypertension,coronary heart disease and chronic renal insufficiency were statistically significant(P<0.05);Logistic regression analysis showed that BMI,FEV₁/FVC,smoking and PaO₂ were the risk factors(P<0.05),which were the independent risk factor for COPD in OSAHS patients.Multivariate regression analysis showed that BMI(OR=3.180),FEV₁/FVC(OR=3.168),smoking(OR=2.803) and PaO₂(OR=1.870)were included into the Logistic regression model(P<0.05). Conclusion The obesity,lung function injury,smoking and hypoxia are the independent risk factors of obstructive sleep apnea hypopnea syndrome in patients with chronic obstructive pulmonary disease,which need more attentions to be paid by clinicians.