Poincaré plot indexes of pulse rate variability capture dynamic adaptations after reactive hyperemia in type 2 diabetic patients

Despite known contributions of type 2 diabetes mellitus to atherosclerosis and autonomic nervous dysfunction, tool for simultaneous evaluation of these two disease entities has not been reported. Using our previously validated air pressure sensing system (APSS) for atherosclerosis assessment, peak-peak intervals (PPIs) of wrist arterial waveforms from baseline and reactive hyperemia (RH) were obtained. Through data analyzing with heart rate variability frequency domain and non-linear Poincaré method, the autonomic nervous function of healthy upper middle-aged subjects (Group 1, n=21), and type 2 diabetic patients (Group 2, n=25) were assessed. Using SD1/SD2 ratio (SSR_1-10), PPIs of the same dividual were compared before and after RH induction. Reduced SSR_1-10 was noted only in diabetic patients (p=0.004). However, no difference in low/high frequency power ratio was noted among different groups. In conclusion, our results demonstrated failure of diabetic patients in restoring baseline autonomic nervous function after RH. APSS, therefore, is also validated for autonimic nervous dysfunction evaluation in diabetic subjects.