Abstract: Objective  To observe the changes of autonomic nervous tone in continuous ambulatory peritoneal dialysis (CAPD) and maintenance hemodialysis (MHD) patients during a single dialysis process using heart rate variability (HRV) and skin sympathetic nerve activity (SKNA).  Methods  From February 2021 to July 2021, CAPD patients and MHD patients from the First Affiliated Hospital of Nanjing Medical University were enrolled. These patients were assigned into two groups: CAPD group and MHD group. High-frequency ECG signals were collected for 4 consecutive hours from the beginning of a single dialysis session. After signal processing, HRV and SKNA were analyzed, and then the average values of each 30 minutes were calculated, respectively. The average voltage of SKNA (aSKNA) and HRV indexes were compared between the two groups.  Results  A total of 30 CAPD patients and 50 MHD patients were included. The mean heart rate and normalized high frequency power (HFn) of 0-30 minutes and 30-60 minutes were different between the two groups (t=-2.210, -2.426, Z=2.226, 2.027, P=0.037, 0.018, 0.026, 0.043), the normalized low frequency power (LFn) of 30-60 minutes was also different (t=-2.548, P=0.013). After dialysis, low frequency power to high frequency power ratio (LF/HF) increased in both groups (Z=3.162, 2.980, P=0.011, 0.020), while changes happened earlier in the MHD group. The mean heart rate increased (q=3.336, P=0.009) and HFn decreased (Z=4.123, P＜0.001) significantly in MHD group. There was no significant difference in aSKNA between two groups (0.010＜|Z|＜1.109, all P＞0.05), but MHD group showed a greater dynamic change (Z＞3.125, P＜0.05).  Conclusion  During a single dialysis session, MHD patients showed a greater change in autonomic system tone compared with CAPD patients. 

Key words: Peritoneal dialysis, Hemodialysis, Heart rate variability, Skin sympathetic nerve activity, Autonomic nervous system.