Glucose, insulin and C-peptide kinetics during continuous ambulatory peritoneal dialysis

The insulin and C-peptide kinetics due to glucose (50 g), given intraperitoneally or enterally has been compared in five non-diabetic patients on continuous ambulatory peritoneal dialysis (CAPD). The fasting C-peptide concentrations were three to ten times the normal values whereas the fasting plasma insulin concentrations were within normal limits. After intraperitoneal glucose administration a more marked hyperglycaemia (p less than 0.05) and a more long lasting hyperinsulinaemia (p less than 0.05) was found than after the enteral glucose load. The relative change in plasma C-peptide was slower and less pronounced in both experiments. C-peptide concentration in plasma did not differ significantly between the two experiments. Estimated total body clearance (Kt) for insulin was higher than for C-peptide (p less than 0.01), but dialysis clearance (Kd) for C-peptide was higher than for insulin in both experiments (p less than 0.01).