Does dialysis therapy improve autonomic and peripheral nervous system abnormalities in chronic uraemia?

Objectives. Autonomic nervous system (ANS) dysfunction and peripheral neuro pathy occur in patients with chronic renal insufficiency. Adequate renal re placement therapy should prevent development or correct these abnormalities . Design and subjects. We studied retrospectively ANS and peripheral neuropat hy in 32 patients with chronic uraemia who received either haemodialysis (1 6) or peritoneal dialysis (16) therapy, and compared the observed dialysis efficiency with changes in neurological function. Methods. Heart rate variability (HRV) time domain indices and peripheral se nsory nerve conduction studies were followed for a mean of 2.9 years. The a dequacy of haemodialysis (HD) efficiency was estimated by Kt/V, an index of fractional urea clearance. Adequacy of continuous ambulatory peritoneal di alysis (CAPD) was estimated on the basis of the patient's wellbeing and nut ritional status as excellent, satisfactory or poor. Based on observed chang es in HRV time domain measures, the observations were divided in three subg roups: improved, unchanged or deteriorated. Results. The peripheral sensory nerve conduction studies were abnormal in 3 8% of the patients and did not change significantly during the study. Impro vement in HRV time domain measures occurred in HD patients with mean Kt/V > 1.20 or in CAPD patients with satisfactory or excellent response to dialys is treatment. Values of Kt/V < 0.85 in HD patients were associated with pro gressive deterioration of autonomic neuropathy. Diabetic patients (n = 4) d iffered from others as their HRV was grossly abnormal and did not improve. Conclusions. The adequacy of haemodialysis is a predictor of improvement of cardiac autonomic nervous function in chronic uraemia. The same trend of i mprovement was seen also in CAPD patients.