Changes of heart rate turbulence and heart rate variability in patients with type 2 diabetes mellitus

Objective:To study the changes of heart rate turbulence(HRT) and heart rate variability(HRV) in patients with type 2 diabetes mellitus(T2DM).Methods:A total of 98 T2DM patients were enrolled as T2DM group and 100 non-diabetes subjects were treated as normal control group.The 24h dynamic electrocardiogram,and calculated for HRT indicators,including turbulence onset(TO) and turbulence slope(TS),and HRV indicators,including standard deviation of normal to normal RR intervals calculated over the 24 h period(SDNN),PNN50 and ratio of low frequency value/high frequency value(LF/HF) were measured in all sabjects.Relationships among indicators above were analyzed then.Results:Compared with normal control group,there were significant increase in TO [(-4.79±3.98)% vs.(-1.31±3.95)%] and LF/HF [(2.37±0.96) vs.(3.64±1.33)],significant decrease in TS [(8.36±4.47) ms vs.(4.10±4.28) ms],SDNN [(138.46±21.33) ms vs.(98.79±26.87) ms] and PNN50 [(12.83±10.91)% vs.(3.45±2.73)%] in T2DM group,P0.05～0.01;Positive rates of TO(75.5% vs.20.0%),TS(46.9% vs.4.0%),SDNN(30.6% vs.9.0%) in T2DM group were significantly higher than those of normal control group(P0.05～0.01);Indicators of HRV possessed correlation with those of HRT(r=-0.52～0.54,P0.05～0.01).Conclusion:Heart rate turbulence and heart rate variability may be an effective and noninvasive method to discover cardiac autonomic nervous system disturbance in patients with type 2 diabetes mellitus in early period.