Analysis On Clinical Features And Risk Factors For Concurrent Obstructive Sleep Apnea In Chronic Obstructive Pulmonary Disease Patients

Part one Clinical features of chronic obstructive pulmonary disease combined with obstructive sleep apneaObjective To analyze clinical features of patients with chronic obstructive pulmonary disease（COPD）complicated with obstructive sleep apnea（OSA）,and evaluate the predictive value of STOP-Bang questionnaires in predicting various degree of OSA in patients with COPD.Methods From December 2016 to December 2018,a total of 476 patients with COPD who visited Renmin Hospital of Wuhan University were enrolled,and a sample of 431 subjects were analyzed in the final.All patients completed pulmonary function test,mMRC,CAT evaluation,ESS,SACS,BQ and SBQ survey and PSG test,and clinical data was collected too.According to the results of PSG,subjects were divided into COPD alone group and with OSA（overlap syndrome,OVS）group.Clinical features were analyzed between the two groups.The predictive value of the four questionnaires in predicting various degree of OSA in patients with COPD were compared by receiver-operating characteristic curve statistics.Results Of the 431 subjects,there were 388 males（90.0%）and 43 females,with an average age of 67.4±8.9 years.There were 96 cases（22.3%）in COPD alone group,335 cases（77.7%）in OVS group,184 cases（42.7%）,96 cases（22.3%）and 55cases（12.8%）in COPD combined with mild,moderate and severe OSA group,respectively.The age,body mass index（BMI）,neck circumference and smoking index in OVS group were significantly higher than those in COPD group（P<0.05）and there were no significant difference in gender composition,or the proportion of age over 50 years（P>0.05）.The proportion of habitual snoring,apnea,daytime fatigue and drowsiness,and scores of the four clinical sleep questionnaires in OVS group was higher than that in COPD alone group with P≤0.05,but there was no significant difference in the proportion of the sensation of choking during sleep between the two groups with the value of P=0.119.AHI,oxygen reduction index（ODI）,the total monitoring time spent below 90%oxygen saturation（TS90%）in OVS group were higher than those in COPD alone group（P≤0.05）and the lowest oxygen saturation of blood（LSaO₂）in sleep was significantly lower（P<0.001）,but there was no significant difference in mean blood oxygen saturation（MSaO₂）with P=0.082.The forced expiratory volume in the first second（FEV₁）,the percentage of the predicted FEV₁（FEV₁%）and FEV1/FVC in the OVS group were higher than those in the COPD alone group with P≤0.05,but there was no significant difference in forced vital capacity（FVC）,and the percentage of the predicted FVC（FVC%）between the two groups（P>0.05）.SBQ performed better than that of ESS,SACS and BQ in predicting various degrees of OSA.When screening mild-moderate-severe OSA（AHI≥5 events/h）,the high risk cut-off point of SBQ was SBQ≥3 points;the sensitivity,specificity and AUC were 92.8%,40.6%,0.723respectively,and the odd ratio（OR）was 2.161.When AHI>15 events/h,AUC was0.733.When predicting severe OSA（AHI>30 events/h）,the recommended threshold of SBQ was SBQ>4;the sensitivity,specificity and AUC were 67.3,82.2,0.827respectively;the positive and negative likelihood ratio were the highest with a value of 3.78 0.4 separately;the OR values were 2.977.Conclusion The patients with OVS had higher age,BMI,neck circumference and smoking index,higher proportion of habitual snoring,apnea,daytime fatigue and drowsiness and higher scores of the four sleep questionnaires,and more severe nocturnal hypoxia than those in COPD alone.There was no significant difference in gender composition,the score of mMRC,the proportion of the sensation of choking during sleep and mean nocturnal blood oxygen saturation between the two groups.SBQ performed better than SACS,BQ and ESS in predicting various degrees of OSA in this group of patients with COPD.Part two Risk factors for concurrent obstructive sleep apnea in patients with chronic obstructive pulmonary diseaseObjective: To compare clinical characteristics between patients with chronic obstructive pulmonary disease（COPD）alone and COPD-OSA overlap（overlap syndrome,OVS）,and analyze risk factors for OSA in patients with COPD.Methods:A total of 431 patients with COPD were divided into OVS group and COPD alone group according to the results of polysomnography,and their clinical characteristics were summarized.The risk factors for OSA overlapping in COPD patients were identified by univariate and multivariate logistic regression analysis.Results:Age,BMI,neck circumference（NC）,smoking index（SI）,the values of FEV1% and the ratio of FEV1/FVC in OVS group were significantly higher than those in COPD alone group,and the proportion of severe COPD is lower than COPD group（P<0.05）.The scores of CAT,ESS,SACS in OVS group were significant higher than in COPD only group,with all P values <0.05.There were no significant difference in gender composition,dyspnea scale（m MRC）score,the duration of COPD,the numbers of acute exacerbations and hospitalizations,prevalence of hypertension,coronary heart disease,cor pulmonale or diabetes mellitus in the two groups（all P>0.05）.Risk factors for OSA combined in patients with COPD included age,BMI,NC,CAT,ESS and SACS（P<0.05）.Furthermore,BMI,CAT,ESS were the independent risk factors for OSA in COPD patients（P< 0.05）.Compared with mild or moderate COPD cases,patients with severe COPD（FEV1% < 50%）had a lower risk of having OSA（β =-0.557,OR = 0.573,95% CI 0.342⁰.960,P = 0.035）.Conclusions Compared patients with COPD alone,concurrent OSA in COPD patients had worse quality of life,more daytime sleepiness.BMI,CAT,ESS were the independent risk factors for OSA in patients with COPD.The risk for having OSA in severe COPD patients was lower than cases with mild or moderate COPD.