LONG-TERM THERAPY OF IDDM WITH AN IMPLANTABLE INSULIN PUMP

OBJECTIVE - To examine the long-term benefits and risks of treatment o f IDDM with an implantable programmable insulin pump. RESEARCH DESIGN AND METHODS - Seventy-six patients with IDDM were studied at nine clin ical centers. After 3-4 months of intensive subcutaneous therapy, the Infusaid Model 1000 pump was implanted, and insulin was delivered eith er intraperitoneally or intravenously for an average of 39.6 +/- 10 mo nths (251 patient-years). Data was collected for glycemic control, lip id levels, weight gain, insulin requirements, adverse events, and qual ity of life. Sixty-three patients were also followed for 8.5 +/- 6.3 m onths (45 patient-years) after pump therapy was discontinued. RESULTS - Mean quarterly HbA(1c) fell with subcutaneous intensive therapy and remained stable on implantable pump therapy between 6.9 and 7.5%. Seve re hypoglycemia was relatively rare, with only 4 episodes/100 patient- years of implantable pump therapy. This rate was significantly less th an with subcutaneous intensive therapy before implantable pump initiat ion (33 episodes/100 patient-years) or after discontinuation of implan table pump therapy (36/100 patient-years) (P < 0.003). Weight did not increase significantly in the Ist year of therapy, but increased by 2. 0 +/- 4.3 kg after 3 years of therapy. There were Ilo significant diff erences in metabolic control or adverse events between intraperitoneal and intravenous insulin therapy except for minor differences in lipid levels and the more frequent development of catheter obstruction with intravenous delivery. Most pump slow-downs and catheter occlusions we re corrected noninvasively. Quality of life, as measured by the Diabet es Control and Complications Trial instrument, showed high satisfactio n and improved impact scores. CONCLUSIONS - Long-term implantable pump therapy maintained HbA(1c) in a range similar to intensive subcutaneo us therapy, but with fewer episodes of severe hypoglycemia. Although p ump and catheter occlusions remain a limitation, patient satisfaction with implantable pump therapy remains high.