The effect of long-term use of U-500 insulin via continuous subcutaneous infusion on durability of glycemic control and weight in obese, insulin-resistant patients with type 2 diabetes.

Objective: To evaluate the long-term efficacy and safety of U-500 insulin administered via continuous subcutaneous insulin infusion (CSII) in patients with insulin-resistant type 2 diabetes and high insulin requirements.

Methods: We retrospectively reviewed the effects of U-500 insulin administered via CSII on durability of glycemic control (HbA1c), body weight, total daily insulin dose, and incidence of hypoglycemia in 59 patients with insulin-resistant type 2 diabetes (duration of treatment 1 to 9.5 years; mean treatment duration 49 months). All variables were analyzed by 1-way analysis of variance (ANOVA) from pre-U-500 baseline to time points from 3 to 114 months.

Results: After 3 months of U-500 insulin use, hemoglobin A1c dropped significantly from a mean baseline of 8.3% to a mean value of 7.3% (P = .003), and this improvement was sustained for over 66 months of use. There was no significant overall change in body weight or total daily insulin dose over time with the use of U-500 insulin. For those subjects who did gain weight, there was a parallel increase in insulin dose that correlated with weight gain. The overall incidence of severe hypoglycemia was low over the study period, with a mean occurrence of 0.1 episodes per patient per year.

Conclusions: U-500 insulin is safe and effective for extended use (up to 9.5 years) in patients with insulin-resistant type 2 diabetes who require high insulin doses, and provides sustained glycemic control without causing excessive weight gain.