The Relationship Between Carotid Intima-media Thickness And Heart Rate Variability,inflammatory Markers In Patients With Essential Hypertension

Objective: To investigate the relationship between carotid intima-media thickness and heart rate variability,inflammatory markers in patients with essential hypertension(EH).Method: A total of 88 EH patients admitted to our hospital from 2017-01 to 2018-01 were enrolled.The degree of artery atherosclerosis was assessed by carotid artery intima-media thickness(IMT).Based on IMT,the patients were divided into 3 groups: the control group(IMT<0.9mm),the thickened IMT group(0.9?IMT<1.2mm)and the clot group(IMT?1.2mm).Synchronic 24 h dynamic electrocardiogram and 24 h ambulatory blood pressure monitoring were performed in all patients.Keep a record of time-domian analysis of HRV such as the SDNN,the standard deviation of normal-to-normal intervals,and the SDANN calculated as the standard deviation of the mean of all normal RR intervals for 5-min segments,as well as the p NN50,calculated as the percent difference between adjacent normal RR intervals greater than 50 ms,and the r MSSD,calculated as the square root of the mean of the sum of the squared differences between adjacent normal RR intervals.The frequency-domain analysis of HRV such as low frequencies(LF)and high frequencies(HF)were also taken down.Further,the record of inflammatory markers such as white blood cell count(WBCC)and high sensitive C-reactive protein(hs-CRP)were also underwent.T-test,chi-square test,pearson liner correlation study and multivariable liner stepwise regression analysis were conducted to explore the relationship between HRV,inflammatory markers and IMT.Result:(1)Respectively compared with the control group,the thickened IMT group and the clot group showed decreased HRV time-domain parameters(SDNN,SDANN,RMSSD,PNN50)(p<0.05).And there was a significant difference between the clot group and the thickened IMT group.(2)Respectively compared with the control group,the thickened IMT group and the clot group showed increased 24 h mean heart rate(p<0.05).And there was a significant difference between the clot group and the thickened IMT group.(3)The LF and HF of spectrum analysis in the thickened IMT group and the clot group were lower than those in the control group,as well as a gradually higher LF/HF(p<0.05).And there was a statistical difference between the clot group and the thickened IMT group.(4)The Pearson correlation analysis of IMT and inflammatory markers showed that there was a positive correlation between IMT and hs-CRP,WBCC,as well as a negative correlation between IMT and HRV parameters.Moreover,we found that inflammatory markers were negatively correlated with HRV parameters(p<0.05).(4)Multivariate linear stepwise regression analysis using IMT as the dependent variable showed that there was a linear regression relationship between IMT and hs-CRP,WBCC,SDNN,LDL-C and age.And the WBCC had the most significant effect on IMT.Conclusion: IMT was positively correlated with the levels of hs-CRP and WBCC,negatively correlated with the heart rate variability in patients with essential hypertension.And the levels of hs-CRP and WBCC were negatively correlated with the indicators of heart rate variability.