Mathematical modeling of the glucose-insulin system during peritoneal dialysis with glucose-based fluids.

The purpose of this study was to analyze the effect of peritoneal dialysis with glucose-based solution on plasma glucose and insulin responses in patients on continuous ambulatory peritoneal dialysis (CAPD), describe the glucose-insulin system using a mathematical model, and identify abnormalities in this system. Six-hour dwell studies--using glucose 3.86% solution with a volume marker--were performed in 13 stable, fasting, nondiabetic CAPD patients. We used a mathematical model based on the previous works of Stolwijk and Hardy (1974) and Tolic et al (2000) to estimate the parameters of glucose-insulin system, insulin sensitivity index (Sl), and glucose effectiveness at basal (SG) and zero (GEZI) insulin. The individual peaks in plasma glucose and insulin concentrations occurred after 30-60 minutes of the dwell, with the average increase of 52% and 168% over the initial values, respectively. Increased insulin resistance was found in most of these patients. Both clinical and simulation results demonstrated a high interpatient variability in glucose and insulin kinetics and glucose-insulin system parameters in the patients. We demonstrated a successful control of increasing plasma glucose by insulin, despite an increased insulin resistance, during CAPD.