Hyperinsulinism reduction associated with icodextrin treatment in continuous ambulatory peritoneal dialysis patients

Glucose absorption from peritoneal dialysis solutions causes a chronic stimulation of insulin secretion, which leads to hyperinsulinism. The use of solutions without glucose should correct this metabolic derangement together with the associated cardiovascular risk. To verify this hypothesis, we studied the entire non diabetic continuous ambulatory peritoneal dialysis (CAPD) population of our center: 27 patients with a mean age of 62 +/- 15 years, and a median 17 months on treatment. Morning fasting serum insulin was 32.8 +/- 9.3 microU/mL; glucose, 104.4 +/- 21.8 mg/dL; triglycerides, 162.4 +/- 125.7 mg/dL; cholesterol, 221.9 +/- 54.7 mg/dL; intact parathyroid hormone (iPTH), 212 +/- 189 pg/mL; fibrinogen, 519 +/- 112 mg/dL; body mass index, 24.1 +/- 4.1; and daily erythropoietin subcutaneous therapy dose, 17 +/- 6 U/kg. Insulin sensitivity, measured as ISI-HOMA (insulin sensitivity index, derived from the homeostasis model assessment) was 2.4 +/- 0.7. Daily glucose load, calculated from dialytic schedules, was 135 +/- 38 g. Of the 27 patients, 12 were treated with standard glucose solutions during the day and with one icodextrin dwell during the night for a median of 9 months (range: 1-28). The remaining 15 patients were treated with standard glucose solutions. The icodextrin group showed significantly lower serum insulin levels (28.6 +/- 6.0 microU/mL vs 36.1 +/- 10.2 microU/mL, p = 0.021) and significantly higher ISI-HOMA values (2.7 +/- 0.5 vs 2.2 +/- 0.7, p = 0.041) than the control group. The two groups showed no significant differences for glucose, triglycerides, cholesterol, iPTH, fibrinogen, body mass index, or erythropoietin therapy dose. Daily glucose load was lower in the icodextrin group, but without reaching statistical significance (128 +/- 31 g vs 142 +/- 43 g). This study shows, in a preliminary way, that the chronic use of icodextrin in the long nighttime dwell can reduce serum insulin levels and increase insulin sensitivity in CAPD patients.