INSULIN KINETICS IN TYPE-I DIABETIC-PATIENTS TREATED BY CONTINUOUS INTRAPERITONEAL INSULIN INFUSION - INFLUENCE OF ANTIINSULIN ANTIBODIES

Continuous intraperitoneal insulin infusion (CIPII) is a promising the rapy of patients with Type 1 (insulin-dependent) diabetes mellitus (ID DM), since it improves metabolic control and decreases frequency of se vere hypoglycaemia. This could be due to more appropriate insulin kine tics. Our aim, therefore, was to compare plasma free insulin levels ac hieved in patients with Type 1 diabetes chronically treated with CSII or CIPII. Furthermore, as anti-insulin antibodies increase with this t reatment, we wanted to assess their influence upon insulin kinetics. P lasma free insulin profiles were obtained during the night and then af ter the bolus for breakfast and the bolus for lunch in 11 patients wit h Type 1 diabetes treated successively by CSII and CIPII. In another g roup of 16 patients with long-term Type 1 diabetes, treated by CIPII, we examined the influence of anti-insulin antibody level on insulin ki netics after a bolus. During the night, plasma free insulin levels wer e lower with CIPII than with CSII (12:00 am: 10.1 +/- 1.7 vs 18.5 +/- 2.6 mU l(-1); 4:00 am: 9.1 +/- 2 vs 15 +/- 3 mU l(-1)), p < 0.01. Afte r the bolus, CIPII lead to an earlier (1h vs 3h) and higher (25.8 +/- 3.3 vs 18 +/- 2.7, p < 0.05) plasma free insulin peak than CSII. With CIPII, the return to baseline level was observed within 3 h. Conversel y, during CSII, insulin levels did not return to baseline until the ne xt meal. After the bolus, high insulin-antibody levels were associated with a reduced maximal value of plasma free insulin peak. Taken toget her, these findings suggest that CIPII provides plasma free insulin pr ofiles which are much closer to physiology than CSII. This could expla in the lower rate of severe hypoglycaemia observed with this type of t reatment. But in long-term CIPII treated patients with high anti-insul in antibody level, insulin profile could be moderately modified. This emphasizes the need for a less immunogenic insulin preparation.