Long-term safety and efficacy of programmable implantable insulin delivery systems

Since only short-term studies of continuous intraperitoneal insulin infusion (CIPII) therapy using implantable programmable insulin delivery systems have been performed to show this method of diabetes therapy to be safe and efficacious, we have performed long-term studies to assess its safety and efficacy.

For 78 patient-years of follow-up, we have longitudinally studied the incidence of diabetic ketoacidosis and severe hypoglycemia in 25 type 1 diabetic patients treated with CIPII. We also compared, cross-sectionally, the long-term safety and efficacy of CIPII to intensive subcutaneous insulin therapy using intermittent injections or continuous subcutaneous insulin infusion. Finally, we examined the relationship between glycated hemoglobin levels and the standard deviation of daily blood glucose excursion.

Cross-sectional analysis revealed similar degrees of metabolic control accompanied by significantly decreased rates of both ketoacidosis (0.013 events/patient/year) and severe hypoglycemia (0.05 events/patient/year) during CIPII compared to intermittent injections and continuous subcutaneous insulin infusion therapy. A four-fold decrease in the rate of severe hypoglycemia was observed during longitudinal comparison of pre- and post-implantation complication rates. A relationship was also shown between decreased levels of mean glycated hemoglobin and the standard deviation of blood glucose excursions during CIPII therapy.

Our data demonstrate that long-term therapy with CIPII is as effective as other methods in achieving near-normal levels of glycated hemoglobin, which in CIPII is associated with a decreased standard deviation of blood glucose excursions. Further, CIPII using implantable programmable insulin delivery systems is the safest method described for intensive insulin therapy in home blood glucose monitoring type 1 diabetic patients.