Clinical and financial outcomes of switching insulin glargine to insulin detemir in a veteran population with type 2 diabetes

Background: Although glargine and detemir are both FDA-approved in the U.S. as long-acting insulin analogues, inherent differences in the insulins may lead to varying outcomes. This study examined changes in clinical measures and associated costs for veterans with type 2 diabetes on insulin therapy converted from insulin glargine to insulin detemir. Methods: A retrospective before-and-after comparison study was performed at a single-site medical center located in the southwestern U.S., comprising 133 Veterans diagnosed with type 2 diabetes receiving insulin therapy with glargine and converted to insulin detemir using a 1: 1 unit dosage ratio. Patients' A1c, weight, body mass index, total daily dose, and estimated monthly insulin costs during and after conversion were compared employing Wilcoxon signed-rank tests. These measures were similarly assessed in patients at A1c goal (<7 %) prior to conversion. Results: When switched from insulin glargine to insulin detemir, an increase in A1c (median of 7.7 % to 8.3 %, p < 0.01) and total daily dose (TDD: 40 to 46 units/day, p < 0.01) resulted. Monthly insulin costs decreased 19 % ($47 to $38, p < 0.01), or roughly a one-year savings of $110 per patient. An increase in A1c was similarly observed for patients at-goal prior to conversion but remained at-goal post-conversion (6.5 % to 6.7 %, p = 0.02). Conclusion: The increase in A1c and TDD following conversion from insulin glargine to insulin detemir suggests that glargine requires a smaller amount of units to reach the same glycemic-lowering ability compared to detemir. Despite the observed insulin cost savings associated with detemir, future studies should also determine overall costs (including indirect) and benefits associated with switching from glargine to detemir among Veteran with Type 2 diabetes.