Objective: To determine the safety and efficacy of U-500 regular insulin delivered by continuous subcutaneous insulin infusion (CSII) as treatment for patients with type 2 diabetes and severe insulin resistance (mean 24-hour insulin requirement, 1.46 U/kg daily) who had failure of previous insulin therapy with either multiple daily injection (MDI) regimens or CSII using U-100 insulin analogues.
Methods: The study group consisted of 9 patients with type 2 diabetes and severe insulin resistance with hemoglobin A1c (A1C) values that exceeded 7.0%. All patients had been previously treated with MDI regimens with either glargine or NPH insulin plus insulin lispro, insulin aspart, or U-500 regular insulin before meals or CSII with insulin lispro or aspart. Treatment was changed to U-500 regular insulin by CSII with use of one of the following insulin pumps: MiniMed 508, Medtronic-MiniMed Paradigm 511, or Deltec Cozmo. A1C, weight, and total daily insulin dose were determined at baseline and after 3 months of CSII with U-500 regular insulin. Statistical comparisons were made by using a paired t test.
Results: After 3 months, treatment with U-500 regular insulin by CSII resulted in a statistically significant mean decrease in A1C (P = 0.026) of 1.14%, a marginal mean increase in weight of 4.1 lb (P = 0.078), no significant change in total daily insulin dose (P = 0.622), and no clinically significant hypoglycemic episodes. Moreover, all study patients preferred the new treatment option over their previous regimens.
Conclusion: U-500 regular insulin by CSII is a safe and effective therapeutic intervention for patients with type 2 diabetes who have had treatment failure with MDI insulin regimens or CSII with use of U-100 insulin or insulin analogues.