Autonomic function in uremic patients treated by hemodialysis or CAPD and in transplant patients

Tests of autonomic nerve function have been performed in patients receiving dialysis and following transplantation. These tests, consisting of blood pressure and heart rate response to standard stimuli were carried out in four groups of subjects: 10 patients were receiving continuous ambulatory peritoneal dialysis (CAPD), 12 hemodialysis, 11 had functioning transplants and there were 12 healthy subjects. The heart rate responses to the Valsalva maneuver, deep breathing and standing were equally reduced in the hemodialysis and CAPD patients while the responses in the transplant patients were not significantly different from those in the control subjects. Peroneal nerve conduction velocity was used to measure the degree of peripheral neuropathy and while in most patients there was a positive relationship with the autonomic studies, in five patients the results were clearly dissociated. Plasma parathyroid hormone (PTH) levels were elevated in both the dialysis groups but not in the transplanted patients and there was no correlation between the PTH levels and any of the neurological tests. This study has confirmed the presence of autonomic neuropathy in dialysed uremic patients and has demonstrated almost complete resolution of this following transplantation but has failed to show any benefit of CAPD over hemodialysis in protecting against neuropathy.