Evaluation of dosing and clinical outcomes in patients undergoing conversion of insulin glargine to insulin detemir.

Study Objectives: To evaluate the dose and frequency of insulin detemir for patients with diabetes mellitus undergoing conversion from insulin glargine to insulin detemir, and to assess glycemic control, weight gain, and risk of hypoglycemia after converting to insulin detemir.

Design: Retrospective medical record review.

Setting: Large academic medical center.

Patients: Thirty-one patients with type 1 (10 patients) or type 2 (21 patients) diabetes who were converted from insulin glargine to insulin detemir by usual practice between January 1, 2006, and March 3, 2007, after an Iowa Medicaid formulary switch.

Measurement And Main Results: Data were collected for 12 months after conversion from insulin glargine to insulin detemir. No significant change in mean basal insulin dose was noted in patients with type 1 diabetes at the end of 12 months (insulin detemir 31.1 units/day vs baseline insulin glargine 32.0 units/day, p=0.89; insulin detemir 0.41 unit/kg/day vs baseline insulin glargine 0.42 unit/kg/day, p=0.91). In patients with type 2 diabetes, however, the mean basal insulin dose was significantly higher with insulin detemir compared with baseline insulin glargine (74.2 vs 55.8 units/day, p=0.002; 0.68 vs 0.48 unit/kg/day, p=0.001) at the end of 12 months. Twice-daily administration was required in a higher proportion of patients receiving insulin detemir (15 patients [48%]) at 12 months compared with insulin glargine (4 patients [13%]) at baseline (p=0.043). A significant change in hemoglobin A(1c) was not observed in patients with type 1 diabetes (9.7% with insulin detemir vs 9.3% with insulin glargine, p=0.41) or type 2 diabetes (9.4% with insulin detemir vs 9.7% with insulin glargine at baseline, p=0.57) despite the use of higher insulin detemir doses in patients with type 2 diabetes. No significant differences in weight or frequency of hypoglycemia were noted.

Conclusion: Treatment with insulin detemir appears to require more frequent administration and higher insulin doses compared with insulin glargine in patients with type 2 diabetes, with 33% higher doses, on average, observed in this study. These findings suggest that a unit-for-unit conversion from insulin glargine to insulin detemir, as suggested by the manufacturer of insulin detemir, may not be adequate in patients with type 2 diabetes.