Continuous intraperitoneal insulin infusion partly restores the glucagon response to hypoglycaemia in type 1 diabetic patients

The glycaemic and hormonal responses to a hypoglycaemic event induced by an i.v. bolus of insulin was studied in seven type diabetic patients treated first with continuous subcutaneous insulin infusion (CSII) and subsequently with continuous intraperitoneal insulin infusion (CIPII). Arterialised blo od glucose and venous hormonal responses were analyzed. HbA1c was improved by CIPII. Although a regimen of a higher basal insulin i nfusion rate was applied during CIPII the basal peripheral venous insulin l evels were lower. The i.v. bolus of insulin resulted in hypoglycaemia in bo th tests but was more pronounced during the CSII test expressed as a smalle r area under the curve (AUC) for the first hour (13.0 +/- 2.3 vs. 13.7 +/- 1.2 mmol l(-1)' h(-1), p= 0.016, CSII vs. CIPII). The hypoglycaemia resulte d in a significant and similar increase in the plasma levels of adrenaline, cortisol and growth hormone in both experiments. A significant increase in the glucagon level was only observed during CIPII. The incremental glucago n response was also significantly more pronounced in the CIPII test express ed as maximal responses (7.5 +/- 3.0 vs. 17.0 +/- 3.1 pg ml(-1), p = 0.048, CSII vs. CIPII) as well as incremental AUC (5.1 +/- 12.0 vs. 44.4 +/- 13.2 pg ml(-1) h(-1), p = 0.027, CSII vs. CIPII). It seems that CIPII in type 1 diabetic patients could improve the glucagon release to hypoglycaemia. This observation may contribute in explaining why CIPII is associated with a lower incidence of hypoglycaemia in spite of an improvement in metabolic control.