The Study On The Lung Function Of Obstructive Sleep Apnea-hypopnea Syndrome

Part one A study on daytime airway resistance of obstructive sleep apnea-hypopnea syndromeObjective Investigate the changes of daytime airway resistance of obstructive sleep apnea-hypopnea syndrome patients in wakefulness; Investigate daytime airway resistance of different severity of OSAS;Study the role of airway resistance to the variance of apnea-hypopnea index.Methods Choose141patients who diagnosed as OSAS in the sleep lab of Tianjin General Hospital complained of snoring and choking during sleep from2011.10to2012.9,male116,female25, Average age49±12years, BMI30±5.According to AHI,there were26mild OSAS (5≤AHI<15),27moderate OSAS (15≤AHI＜30) and88severe OSAS(AHI≥30).Choose41healthy subjects as snoring group who were not diagnosed OSAS after PSG.The age and body mass index of the control group macthed to the OSAS group,male32,female9, Average age49±13,BMI27±4.IOS were performed for all control and OSAS group subjects to examine the airway resistance. Compare differences of airway resistance between OSAS group and the snoring group;Compare differeces in airway resistance of different severity of OSAS(mild,moderrate,severe).AHI and each index detected by IOS were analyzed by linear correlation analysis,choose the index which were significantly correlated with AHI,then AHI and the index were analyzed by multiple regression analysis.Results:1、Compared to the simple snoring group, the value of R5(146.67±66.42)、 R10(133.30±49.25)、R15(124.15±44.90)、R20(128.97±47.42)、R25(139.48±48.28)、R35(188.52±63.28) of the OSAS group increased significantely(P＜0.05);2, Compared to mild and moderate OSAS respectively, the value of R5、R10、 R15、R20、R25、R35of the severe OSAS increased significangtly (P＜0.05),while there were no significant differences between mild OSAS and moderate OSAS.3Linear correlation analysis showed that AHI were significantely correlated with R5、 R10、R15、R20、R25、R35(The value of r are0.328、0.304、0.282、0.267、0.289、0.295respectively). Stepwise multiple regression analysis of which AHI used as dependent variable and R5、R10、R15、R20、R25and R35used as independent variables showed that R35significantly explained11.7%of the variance of AHI.Conclusion Daytime airway resistance of obstructive sleep apnea-hypopnea syndrome significantly increased,airway resistance of severe OSAS is significantly higher than mild and moderate OSAS. As the severity increases,the airway resistance also has an increasing trend,R5is a determinant of obstructive sleep apnea,the increase of airway resistance play an important role in in the variance of AHI. Part Two Investigation of obstructive sleep apnea-hypopnea syndrome patients with sawtooth sign on the flow-volume curveObjective Investigate the prevalence of sawtooth sign on the flow-volume curve of obstructive sleep apnea syndrome;Analyse the clinical characters of OSAS with sawtooth sign on the flow-volume curve.Methods Choose99patients who diagnosed as OSAS in the sleep lab of Tianjin General Hospital complained of snoring and choking during sleep from2011.10to2012.7,male78,female21.Average age49±12years,BMI30±5.According to AHI,there were21mild OSAS,18moderate OSAS and60severe OSAS. Choose41healthy subjects as snoring group who were not OSAS after PSGThe age and body mass index of the control group macthed to the OSAS group,male32,female9, Average age47±13,BMI27±4. Exclusion criteria:pregnant woman, the patients taking hormones and other drugs that affect sleep structure、neuromuscular disease、 cerebrovascular disease、Hereditary disease and cancer.Questionnaire survey including basic information and disease conditions about hypertension、diabetes etc、 PSG、pulmonary function (Mainly the flow volume curve measurement)were performed and neck circumference、abdominal circumference etc were measured to all subjects who met the inclusion criteria.Compare the prevalence of sawtooth sign of the OSAS and non-OSAS;Otherwise,OSAS were divided into two groups including OSAS with sawtooth sign and OSAS without sawtooth sign,compare the pulmonary function、PSG、clinical characters、neck circumference、abdominal circumference of the two group.Results1、Among99OSAS patients,42(42%) had sawtooth sign on their flow volume curve,57(58%) did not have sawtooth sign on their flow volume curve.among41non-OSAS patients,10(24%) had sawtooth sign on their flow volume curve.31(76%) did not have sawtooth sign on their flow volume curve Through the chi-square test, two groups of sawtooth sign occurrence rate significantly different (x2=4.039, P=0.044).2, Among60severe OSAS,30(50%) had sawtooth sign,30(50%) did not have sawtooth sign;among18moderrate OSAS,6(33%) had sawtooth sign,12(67%) did not have sawtooth sign;among21mild OSAS,5(24%) had sawtooth sign,20(76%) did not have sawtooth sign. Through the chi-square test,there were significant difference of sawtooth sign rate between severe OSAS and mild OSAS (x2=4.348, P=0.037).There was no significant difference between mild OSAS and moderate OSAS (x2=0.622, P=0.105) and between severe OSAS and moderate OSAS (x2=1.548, P=0.213)3、Compared to OSAS without sawtooth sign,the value of R5、R10、R15、R20、R25、R35in OSAS with sawtooth sign increased significantely (P＜0.05)4、Compared to OSAS without sawtooth sign,the rate of current smokers (x2=4.764, P=0.041) and hypertension prevalence (x2=8.267, P=0.005) of OSAS with sawtooth sign were significantly increased; compared to non-OSAS with sawtooth sign,weight、neck circumference、 waist circumference of OSAS with sawtooth sign were significantly increased.(t value were2.619、3.308、4.005respectively, P value were0.012、0.002、0.000respectively), also hypertension prevalence increased significantly (x2=4.752, P=0.029); AHI、LAD、MAD、SIT90of OSAS with sawtooth sign are significantely greater than OSAS without sawtooth sign(t value were2.218、2.009、2.605、2.205respectively, P value were0.029、0.047、0.011、0.030respectively); there were no significant difference of pulmonary function index between OSAS with and without sawtooth sign (P＞0.05)Conclusion The prevalence of sawtooth sign of OSAS is42%; the prevalence of sawtooth sign of OSAS is significantly higher than non-OSAS.as severity of OSAS increases,the trend of sawtooth sign prevalence is increasing.As a subgroup of OSAS,AHI、SIT90、LAD、MAD、ratio of current smoker and prevalence rate of hypertension of OSAS with sawtooth sign are increased.