Objective: To test the effectiveness and safety of U500 regular insulin delivered by continuous subcutaneous insulin infusion (CSII) via the Omnipod insulin delivery system in patients with uncontrolled type 2 diabetes mellitus and severe insulin resistance.
Methods: In this prospective, 1-year, proof-of-concept trial, patients with insulin-requiring type 2 diabetes who had a hemoglobin A1c level of 7.0% or higher and severe insulin resistance (average insulin requirement, 1.74 units of insulin per kilogram each day; range, 1.4 to 2.64 units of insulin per kilogram [average insulin dose, 196.4 units daily]) were identified at routine office visits at Mountain Diabetes and Endocrine Center in Asheville, North Carolina, between December 2007 and August 2008. All patients had been on intensive insulin therapy with or without oral agents for more than 3 months. All patients were switched from baseline failed therapy to U500 regular insulin by continuous subcutaneous insulin infusion via Omnipod. Effectiveness was assessed by hemoglobin A1c measurement and 72-hour continuous glucose monitoring at baseline and at weeks 13, 26, and, 52 and by treatment satisfaction assessed by the Insulin Delivery Rating System Questionnaire at baseline and at week 52 while on U500 via Omnipod.
Results: Twenty-one adults were enrolled (mean age, 54 years; mean duration of diabetes, 4 years; mean body mass index, 39.4 kg/m2; mean insulin requirement, 1.7 U/kg per day; and mean hemoglobin A1c, 8.6%) whose previous treatment with U100 insulin regimens had failed. Twenty patients completed the study. Treatment with U500 insulin via Omnipod significantly reduced hemoglobin A1c by 1.23% (P<.001) and significantly increased the percentage of time spent in the blood glucose target range (70-180 mg/dL) by 70.75% as assessed by continuous glucose monitoring (P<.001) without a significant increase in hypoglycemia. Patients were satisfied with treatment with U500 insulin via Omnipod, and 14 patients elected to remain on treatment at study completion.
Conclusions: U500 insulin delivered subcutaneously continuously via Omnipod is a safe and effective method of insulin delivery in the very insulin-resistant type 2 diabetic population.