Effect of peritonitis on insulin and glucose absorption during peritoneal dialysis in diabetic rats

The intraperitoneal route is frequently used for the administration of insulin in diabetic continuous ambulatory peritoneal dialysis patients. However, there is conflicting evidence as to whether the dosage of intraperitoneal insulin should be increased or decreased during peritonitis in these patients. Glucose and insulin absorption and glycaemic control were evaluated in 2-hour exchanges using 15 ml of 2.5% dextrose dialysis solution in diabetic rats with (group 1) and without (group 2) peritonitis. Fasting blood glucose values at the beginning of the study exchanges were mean +/- SD 17.9 +/- 3.3 mmol/l in group 1 and 18.2 +/- 3.5 mmol/l in group 2. Even though group 1 had a higher percentage absorption of dialysate glucose (65 +/- 19 vs. 47 +/- 7%; p less than 0.05) and higher percentage absorption of dialysate insulin (49 +/- 12 vs. 44 +/- 14%; p less than 0.1), the hypoglycaemic response to the standard intraperitoneal dose of insulin was similar in each group. Plasma C peptide levels remained very low in both groups, thus excluding significant endogenous release of insulin. These data indicate that peritonitis per se does not change intraperitoneal insulin requirements during standardized peritoneal dialysis exchanges in diabetic rats. Insulin requirements may also be unaltered during peritonitis in diabetic continuous ambulatory peritoneal dialysis patients, provided that dialysate glucose load and oral carbohydrate intake are kept constant.