Improvement of uremic autonomic dysfunction after renal transplantation: a heart rate variability study

Autonomic dysfunction in hemodialysis patients is one of the components of uremic neuropathy. In this prospective study, we investigated the effect of renal transplantation on uremic autonomic dysfunction with long-term time-domain and frequency-domain heart rate variability. Fourteen hemodialysis patients (10 male, 4 female; mean age 33 +/- 11 (range 16-50) years) were examined before and at the early after transplantation period (mean 4.6 +/- 1.5 (range 3-7. 5) months). The mean time spent on hemodialysis was 16.7 +/- 15.6 (range 6-65) months. In time-domain analysis, significant increases in all parameters except pNN50 (SD, SDANN, SDNN, rMSSD) were observed after renal transplantation (p < 0.01). In frequency-domain analysis, low-frequency (LF) (0.04-0.15 Hz) and high-frequency (HF) (0.15-0.40 Hz) spectral power were found to be significantly increased after renal transplantation (4.54 +/- 1.04 vs. 12.58 +/- 8. 69 for LF (p = 0.005), 2.80 +/- 1.0 vs. 6.50 +/- 3.55 for HF (p = 0. 005)), but the LF/HF ratio was not different from a pretransplant period (1.71 +/- 0.349 vs. 1.85 +/- 0.49, p = 0.26). It was concluded that autonomic dysfunction in hemodialysis patients is reversible and renal transplantation reverses the sympathetic and parasympathetic autonomic dysfunction simultaneously and at a relatively early stage.