Objective: To assess both peritoneal insulin absorption and adsorption of insulin to the plastic delivery system, and to assess whether variation in peritoneal absorption is related to transport status.
Design: Eight insulin-dependent diabetic patients on continuous ambulatory peritoneal dialysis were studied. Insulin was added to the dialysate. The amount adsorbed by the bag tubing was determined; peritoneal absorption was measured by complete spent dialysate collection.
Results: Only 14% +/- 5% of added insulin was adsorbed onto the dialysate delivery system. Marked variation in peritoneal absorption occurred (38% +/- 14%, range 17%-66%). Variations in membrane transport status did not account for variation in absorption.
Conclusion: Marked variation in peritoneal absorption of insulin occurs, accounting for some of the variation in intraperitoneal insulin requirements. This is not related to membrane transport status.