The Relationship Between OSAS And Arrhythmia And Heart Rate Variability

Background and objectiveObstructive Sleep Apnea Syndrome(OSAS)is a disorder characterized by recurrent upper airway obstruction,apnea and hypopnea,associated with decreased oxygen saturation and disturbed sleep structure during sleep.It was found that OSAS was associated with a variety of arrhythmias and conduction disorders,but the relationship between multiple types of arrhythmia and the severity of OSAS,and its possible mechanism is not clear.The purpose of this study was to observe the main types of arrhythmias and the condition of heart rate variability(HRV)in patients with OSAS of varying severity,to detect the levels of multiple inflammatory factors in serum of OSAS patients and to observe the correlation between polysomnographic parameters or inflammatory factors and arrhythmias or HRV and its possible mechanisms.MethodsIn the first part,we collected 168 patients with snoring in the Second Affiliated Hospital of Soochow University and Xinghua People’s Hospital from January 2011 to December 2016.According to the sleep apnea hypopnea index(AHI),they were divided into control group(AHI <5,n = 31),mild-moderate OSAS group(5≤ AHI <30,n = 55)and severe OSAS group(AHI≥30,n = 82).Detailed medical history data were collected,including hypertension,diabetes,cardiovascular and cerebrovascular diseases and other complications.All patients completed overnight polysomnography(PSG)and 24 h Holter monitoring.Meanwhile we observed the main types of arrhythmias and the condition of heart rate variability(HRV)in patients with OSAS of varying severity,compared the difference among BMI,blood pressure,the incidence of complications,various arrhythmias and HRV parameters in the three groups,and analyzed the correlation between low oxygen indexes at night and HRV parameters.In the second part,141 patients with suspected OSAS were collected in the Second Affiliated Hospital of Soochow University and Xinghua People’s Hospital from February 2016 to February 2018.According to the sleep apnea hypopnea index(AHI),they were divided into control group(AHI <5,n = 34),mild-moderate OSAS group(5≤ AHI <30,n = 48)and severe OSAS group(AHI ≥30,n = 59).Clinical data such as gender and age were collected.All patients completed polysomnography(PSG),24-hour Holter monitoring and blood routine,biochemical indexes and serum hs-CRP,TNF-α,IL-6,and IL-1β testing.We compared the indicators in the three groups,and investigated the correlation between PSG parameters,HRV and inflammatory biomarkers.ResultsIn the first part,there was no significant difference between the three groups in age and sex(P> 0.05).The BMI in patients with mild-moderate OSAS and control group were significantly lower than those in severe OSAS group(P <0.05).SBP and DBP in control group and OSAS group had no significant difference(P> 0.05)before PSG diagnosis at night,SBP and DBP in severe OSAS group were significantly increased after PSG monitoring for 7h(P <0.05).The prevalence of hypertension in severe OSAS group was significantly higher than that in control group(57.3% vs 29.0%,P <0.05),but the difference between mild-moderate OSAS group and severe OSAS group or control group was no statistical significance(P> 0.05).There was no significant difference in the incidence of diabetes,liver disease,smoking history,coronary heart disease and ischemic stroke between the three groups(P> 0.05).Compared with the control group and mild-moderate OSAS group,the incidence of arrhythmia in the severe OSAS group was significantly increased(P<0.05),mainly as ventricular premature beats,ventricular tachycardia,atrial premature beats,atrial tachycardia,Sinus arrest and atrioventricular block,in which the incidence of atrial premature beats in the severe OSAS group was significantly higher than that in the mild-moderate OSAS group and control group(P<0.05),and incidence of atrial tachycardia was significantly higher than that of the control group(P<0.05).The PSG parameters of the three groups varied depending on the level of OSAS.There were significant differences in AHI,ODI,MI,T90 and LSa O2 between the severe OSAS group and the control group or mild-moderate OSAS group(P <0.05).The HRV parameters included SDNN,SDNN,RMSSD,PNN50,LF,HF and LF / HF.5 of 7 parameters showed no statistical significance between groups,while LF/HF was significantly higher in the OSAS groups than the control group(P <0.05),SDNN was significantly lower than the control group(P <0.05).The correlation between AHI and other parameters of HRV was not significant except for the negative correlation between AHI and SDNN(r =-0.236,P = 0.011)in patients with OSAS(P> 0.05).ODI was negatively correlated with SDNN(r =-0.226,P = 0.015)and RMSSD(r =-0.219,P = 0.018)and positively correlated with LF(r = 0.218,P = 0.021).There was no significant correlation between ODI and SDNN index,PNN50 and HF.MI was negatively correlated with SDNN(r =-0.226,P = 0.017),and positively correlated with LF(r = 0.197,P = 0.041).There was no significant correlation between MI and SDNN index,RMSSD,PNN50 and HF.LF / HF was positively correlated with AHI(r = 0.238,P = 0.013),ODI(r = 0.318,P <0.001)and MI(r = 0.278,P = 0.004)in patients with OSAS.In the second part,compared with the control group,there were significant differences in age,sex ratio,BMI,uric acid,TC,and TG in the mild-moderate OSAS group(P<0.05),and in age,sex ratio,BMI,red blood cell count,hemoglobin,hematocrit,uric acid,FBS,TC,TG,LDL,and HDL in severe OSAS group(P<0.05).Compared with mild-moderate OSAS group,there were significant differences in gender ratio,BMI,red blood cell count,hemoglobin,hematocrit,uric acid,FBS,TC,TG,LDL and HDL in severe OSAS group(P<0.05).Heart rate variability(HRV)parameters include SDNN,SDNN index,RMSSD,PNN50,LF,HF,and LF/HF.SDNN,PNN50,and HF in severe OSAS group and mild-moderate OSAS group were significantly lower than those in control group(P<0.05).LF/HF was significantly higher than that of the control group(P<0.05).There was a significant difference in PNN50,HF,and LF/HF between the severe OSAS group and the mild-moderate OSAS group(P<0.05).In terms of inflammation,serum hs-CRP was significantly higher in the mild-moderate OSAS group and the severe OSAS group than in the control group(P<0.05).Serum IL-1β was significantly higher in the mild-moderate OSAS group than in the severe OSAS group(P<0.05).There was no significant difference in other indicators(P>0.05).There was a significant positive correlation between hs-CRP and ODI(r=0.209,P=0.013)and a significant negative correlation with PNN50(r=-0.188,P=0.025).There is no obvious correlation between other indicators.Conclusions(1)Arrhythmias are very common in OSAS patients,especially in moderate-severe OSAS patients,and its mechanism is related to the impairment of cardiac autonomic nerve function caused by hypoxemia.The use of PSG for overnight sleep monitoring is the gold standard for diagnosing OSAS,but the HRV parameter LF/HF ratio can be used as a powerful tool for OSAS screening.(2)Systemic inflammatory reactions existed in patients with OSAS.With the increase of OSAS,inflammation was aggravated,especially serum hs-CRP.Hs-CRP was significantly negatively correlated with PNN50 and positively correlated with ODI.The results suggest that the inflammatory response participates in the occurrence of heart rate variability in OSAS patients.