Influencing Factors Of Decreased Heart Rate Variability In Patients With Type 2 Diabetes Mellitus

Background and ObjectivesAccording to the surveys,about 415 million people worldwide suffer from diabetes mellitus,and 318 million people are in a state of glucose intolerance and increased risk.Cardiac autonomic neuropathy(CAN)is a common form of autonomic nervous dysfunction in patients with diabetes mellitus,but it is often overlooked because of its insidious onset,slow progress and lack of specificity of symptoms.However,its impact can be devastating in patients with DM.CAN is associated with increased mortality,CVD,chronic kidney disease and diabetes morbidity.It has been reported that DCAN increases the risk of death in type 2 diabetes mellitus by about five times.Therefore,early diagnosis and intervention are of great significance to the prognosis of patients.The pathogenesis of diabetic cardiac autonomic neuropathy(DCAN)has not been fully elucidated,but considering that it is the result of multiple factors,Heart rate variability(HRV),which can reflect the tension and balance of cardiac sympathetic and parasympathetic nerves,has been used to evaluate cardiac autonomic nervous function in many diseases,including diabetes mellitus.Once cardiac autonomic neuropathy occurs in type 2 diabetes,the heart is in a state of complete denervalization,and the heart rate tends to be fixed.It does not respond to stimulation that can change the heart rate under normal circumstances,resulting in reduced heart rate variability.HRV has obvious advantages in clinical detection of CAN compared with cardiovascular autonomic reflex tests(CARTs).It is a fast,safe,non-invasive,economical and feasible method to judge CAN.some scholars believe that age,body mass index(BMI),course of diabetes,blood sugar control,blood lipid level and so on play an important role in the occurrence and progress of diabetic complications.In addition,cardiovascular diseases such as coronary heart disease,hypertension can also affect the autonomic nervous system.But the conclusions drawn by different studies are different.It is important to explore the influencing factors of HRV reduction for the prevention and treatment of DCAN in clinical work.In this study,we compared the indicators of type 2 diabetes mellitus patients with normal heart rate variability or abnormal heart rate variability,so as to explore and analyze the possible influence factors leading to decreased heart rate variability in type 2 diabetes patients.Object and MethodsAccording to the inclusion criteria and exclusion criteria,202 patients with type 2 diabetes mellitus were collected.Names,gender,age,height,weight,systolic blood pressure,diastolic blood pressure,duration of diabetes mellitus,with or without coronary heart disease,with or without hypertension,with or without smoking history,oral medication were collected in all cases,body mass index?mean arterial pressure were also calculated,at the same time,the routine examination and test results were collected,including resting heart rate?fasting blood glucose,lipid series(TC,TG,HDL,LDL),the results of heart rate variability analysis,and echocardiographic results.The relevant parameters of heart rate variability include:(1)SDNN;(2)SDANN;(3)RMSSD;(4)PNN50?Cardiac echocardiographic parameters include:RV,IVS,LVPW,LA,LVEDV,LVESV,LVEF,E/A ratio of diastolic function.According to the SDNN values,the patients were divided into normal heart rate variability group(n = 121 cases,SDNN ? 102 ms)and decreased heart rate variability group(n = 81 cases,SDNN < 102 ms).Binary Logistic regression analysis was used to screen the possible influencing factors of decreased heart rate variability in type 2 diabetes mellitus patients.All data were input into SPSS 22.0 software for statistical analysis.Count data was expressed by the number or percentage.Measurement data was demonstrated by(mean±SD).Comparisons between the two groups are based on the results of normality and homogeneity of variance test.Normal distribution data are tested by t-test,non-normal or grade data are tested by chi-square test or rank sum test,and binary Logistic regression analysis is used to screen the possible risk factors leading to decreased heart rate variability in type 2 diabetes patients.P < 0.05 was statistically significant.Results1.According to the heart rate variability grouping,the clinical data of patients in the two groups were compared,and the differences in duration of diabetes mellitus,coronary heart disease,hypertension,resting heart rate and E/A ratio were statistically significant(P <0.05),while the remaining differences were not statistically significant.2.Binary Logistic regression analysis showed that the duration of diabetes mellitus,coronary heart disease,average heart rate and E/A ratio were the main influencing factors for the reduction of heart rate variability in type 2 diabetes mellitus patients(P < 0.05).3.For type 2 diabetic patients with reduced heart rate variability,there was no significant difference in time domain indexes of heart rate variability between short duration group(diabetes duration < 10 years)and long duration group(diabetes duration ? 10 years)(P > 0.05).The SDNN?SDANN?PNN50 of time domain indexes in high heart rate group(resting heart rate > 75 beats/min)were lower than those in low heart rate group(resting heart rate?75 beats/min),The difference was statistically significant(P < 0.05).Conclusions1.Long course of type 2 diabetes,combined with coronary heart disease,increased resting heart rate and decreased E/A ratio are possible influencing factors for the decrease of heart rate variability in patients with type 2 diabetes.2.Among type 2 diabetes patients with reduced heart rate variability,patients with a heart rate greater than 75 beats/min have a more significant decrease in heart rate variability index,suggesting that autonomic nerve regulation of cardiac balance function is decreased,and serious cardiovascular events are prone to occur.