Amelioration of nerve conduction velocity following simultaneous kidney/pancreas transplantation is due to the glycaemic control provided by the pancreas

Abstract

Diabetic polyneuropathy is a common, disabling chronic complication of diabetes mellitus. Previous studies have suggested that combined pancreas- kidney transplantation can ameliorate nerve conduction. The relative contribution of the correction of hyperglycaemia and uraemia on nerve function is still a matter of debate. Nerve conduction velocity (NCV) was assessed before and after simultaneous pancreas and kidney transplantation, and before and after pancreas graft failure in five insulindependent diabetic (IDDM) patients affected by severe diabetic polyneuropathy. Sensory and motor NCV were recorded in five nerves and expressed as a cumulative index for each patient. Metabolic control was evaluated by fasting blood glucose and glycosylated haemoglobin levels. NCV index was below normal values before transplant: -3.8± 0.7 (normal value: 0.89), improved 1 and 2 years after transplant: -3.1 ± 1.3 and -2.6 ±0.9 (p = 0.0019), stabilised until pancreas failure and deteriorated to pretransplant values 2 years after pancreas graft failure: -3.6 ± 1.0 (p = 0.034). Fasting blood glucose levels worsened after pancreas graft failure. HbA(1c) levels, in the normal range during functioning pancreas graft (6.6 ± 0.6%), deteriorated after its failure (8.0 ± 0.6%, p = 0.04). Kidney function was preserved. These data support a positive effect of pancreas transplantation per se on NCV in IDDM subjects with diabetic polyneuropathy, thus demonstrating that metabolic control provided by a self-regulated source of insulin not only halts but also ameliorates nerve function, even if polyneuropathy is advanced.