Cardiac autonomic neuropathy evaluated by time asymmetric analysis for heart rate variability in patients with peritoneal dialysis

In this study we attempt to quantify the correlations between time asymmetric index (TAI) and physiological/ pathological measurements in order to predict the status of cardiac autonomic neuropathy (CAN) in patients with end-stage renal disease. The TAI can explore non-equilibrium dynamics that conventional time and frequency domain indices fail to consider. For comparing the effectiveness and applicability, traditional time-domain and frequency-domain heart rate variability (HRV) indices were also evaluated. To validate the use of TAI, this study investigates 65 DM patients (22 men and 43 women) and divides the data into two subgroups by HbAlc. The HRV indices such as PNN50 and nLF exhibit a positive correlation with CTR in HbAlc+ subgroup, while SDANN and nLHR show a positive correlation between P and Caphos, respectively. In particular, TAI exhibits a significant negative correlation with TNF-alpha, HbAlc, Caphos, and GLUAC in HbAlc+ subgroup, which overcomes the limitation that a single index can be only correlated to one measurement for conventional time-domain and frequency-domain HRV indices. These results manifest that TAI is an integrated HRV index that contains more information than traditional HRV analysis. Moreover, TAI provides a useful and quantified method in evaluation of the cardiac autonomic neuropathy in patients with ESRD. A large cohort study with TAI analysis is in need for potential cardiovascular outcome prediction.