Study Of Reliability Of Cardiopulmonary Coupling Analysis In Diagnosis Of Sleep Disorders

Background Chronic insomnia(CI)and obstructive sleep apnea(OSA)are the first two in the common sleep disorders,and both often comorbid(comorbid obstructive sleep apnea with chronic insomnia,COI).They not only increase patients' sense of fatigue,daytime sleepiness,lack of concentration,cognitive dysfunction,and traffic accidents,but also cause emotional changes(depression or irritability),physical discomfort,and increase the risk of organic diseases.Early diagnosis can not only reduce the pain and functional damage of patients,but also save medical resources Unfortunately,the current methods of clinical evaluation for sleep disorders(CI and OSA)are very limited.Cardiopulmonary coupled(CPC)analysis is a new method of sleep monitoring and evaluation developed in recent years.However,the clinical diagnostic value of CPC in patients with CI and OSA is not clearObjectives The aim of this study is to compare the consistency of sleep quality parameters and sleep breathing parameters detected by CPC analysis and polysomnographm(PSG)in the first three of common samples(CI,OSA and COI)from sleep medical centers,so as to provide a basis for the appropriate selection of diagnostic techniques in the sleep medicine practiceMethods Two hundred and twenty-one patients with insomnia,snoring,subjective nocturnal dyspnea or observed apnea,with or without daytime sleepiness were collected continuously.The general information(age,gender,body mass index,etc.)was collected,and the objective sleep condition was evaluated using overnight PSG and CPC.According to the clinical symptoms and PSG results,the patients consisted of 88 males and 80 females with CI and OSA,including chronic insomnia(CI group,93 cases),OSA(OSA group,36 cases),comorbid OSA with CI(COI group,39 cases).The consistency of sleep and OSA parameters measured with CPC and PSG were analyzed,and the correlation between cardiopulmonary coupling-respiratory event index(REI)and PSG sleep parameters.After controlling confounding factors(gender,age,BMI),the relationship between cardiopulmonary coupling-REI and various sleep and breathing parameters of PSG was analyzed using partial correlation analysis.The weighted kappa coefficient was used to compare the consistency of CPC and PSG for the diagnosis of OSA.The sensitivity,specificity,positive predictive value,negative predictive value,and positive likelihood ratio of CPC to OSA diagnosis were calculated separately.At the same time,with AHI(/h)? 5 as the cutoff point for diagnosis of OSA,the diagnostic performance of CPC at different genders,ages,and BMIs was compared(based on PSG)Results(1)The consistency of sleep parameters? In CI or all patients,the total sleep time(TST),sleep efficiency(SE)and rapid eye movement(REM)sleep time measured by CPC were significantly higher,while wake time after sleep onset(WASO)was significantly lower than those measured by PSG(the specific median comparisons:CI group 420.0 min vs 395.5 min,93.7%vs 81.8%,90.0 min vs 37.5 min,18.0 min vs 63.0 min;all patients 414.0 min vs 392.5 min,91.9%vs 81.9%,72.0 min vs 34.8 min,24.0 min vs 58.4 min;all P?0.001),but there was no significant difference in non-REM sleep time(P=0.663 and 0.272,respectively)In CI group,the light sleep time measured by CPC was similar to the stage 1 time in non-REM(N1,similarly hereinafter)measured by PSG,and the deep sleep time was similar to the PSG-N2(the median comparison was 138.0 min vs 126.5 min and 168.0 min vs 177.0 min)? In OSA group,the sleep parameters were no significant difference in TST,SE,WASO,REM sleep time and non-REM sleep time between CPC and PSG.The light sleep time in CPC was median between the N1 and N1+N2 in PSG,and the deep sleep time in CPC was median between to the N3 and N2+N3 in PSG? In COI group,the TST,SE and non-REM sleep time in CPC was higher(all P<0.05),the WASO was lower(P<0.001),with similar time of REM(P=0.055)than those in PSG(2)Correlations between CPC respiratory event index and sleep breathing parameters of PSG? Correlations between CPC-REI and PSG respiratory parameters:For OSA,COI and all patients,CPC-REI significantly correlated with PSG AHI(r=0.485,P<0.001;r=0.391,P<0.05;r=0.675,P<0.001),with stronger correlation with PSG NREM-AHI For all and COI patients,CPC-REI negatively correlated with the lowest oxygen saturation of PSG(all patients,r=-0.365,P<0.001;COI group,r=-0.610,P<0.001).In CI patients,CPC-REI did not associate with AHI,REM-AHI and NREM-AHI,and minimum blood oxygen saturation in PSG(all P>0.05)? Correlations between CPC-REI and PSG sleep parameters:CPC-REI correlated positively with PSG REM time(all patients,r=0.205,P<0.05;OSA group,r=0.534,P<0.01),N2(OSA group,r=0.515,P<0.01)and micro-awakening index(OSA group,r=0.532,P<0.01;COI group,r=0.404,P<0.05),and negatively with N1(all patients,r=-0.310,P<0.001;OSA group,r=-0.643,P<0.001)and N3(all patients,r=-0.182,P<0.05;OSA group,r=-0.408,P<0.05)(3)Accuracy of CPC for OSA diagnosis? According to AASM's PSG standard,the diagnostic consistency of CPC in OSA was fair(?=0.255,sensitivity=0.83,specificity=0.59,positive predictive value=0.62,negative predictive value=0.81,positive likelihood ratio=2.02).Only when AHI?20/h,the positive likelihood ratio of CPC was more than 4,and the kappa value was 0.580(sensitivity=0.85,specificity=0.82,positive predictive value=0.59,negative predictive value=0.95).?Taking AHI(/h)? 5 as the diagnostic cutoff point,the positive likelihood ratio respectively were male/female=1.47/2.0,age?40 years/40-60 years/>60 years=2.43/1.90/1.95,and BMI<24/?24(kg/m~2)=2.35/1.86).Conclusion CPC could better reflect the sleep quality in OSA patients,but might overestimate the sleep quality in insomniac sufferers.CPC-REI could only link to PSG-measured AHI in low-to-moderate degree but not the lowest oxygen saturation in OSA patients.The consistency in the diagnosis of OSA between CPC and PSG was fair,and it may be more suitable for OSA screening in women,younger than 40 years old,and BMI less than 24 kg/m~2.