Insulin Glargine versus Insulin Detemir: Glycemic Control and Insulin Dose in Type 2 Diabetes Mellitus Patients Using a Medical Record Linkage System in the Netherlands

Background: In randomized controlled trials, patients with type 2 diabetes mellitus required higher doses of insulin detemir than insulin glargine to obtain the same glycemic control. However, this may differ in daily clinical practice. Methods: We conducted a cohort study to compare glycemic control, daily basal insulin dose and persistence in The Netherlands. Data were obtained from the PHARMO record linkage system. Patients starting glargine or detemir in 2004 through 2007 were included if they had a follow-up and history of at least 1 year, including glycated hemoglobin (HbA(1c)) measurements. Glycemic control and insulin dose were compared within 1 year after start of treatment. Average insulin dose was calculated based on the amount of insulin dispensed over time. Results: A total of 708 patients on glargine and 298 on detemir were included. Patients starting glargine had less often used insulin in the previous year (19 versus 31%, P<0.001) and less often used oral antihyperglycemic drugs concomitantly (61 versus 67%, P<0.05) than those starting detemir. Despite a higher mean HbA(1c) at baseline in patients who started glargine (8.6% versus 8.4%), the change from baseline in HbA(1c) at follow-up was greater with glargine (-0.9%) than with detemir (-0.4%, P<0.001). The proportion of patients with HbA(1c) < 7% was similar between the two cohorts. Mean insulin dose at follow-up was significantly lower with glargine than with detemir (31.3 IU versus 36.6 IU, P<0.01). Conclusions: Patients with type 2 diabetes mellitus who were treated with insulin glargine achieved better glycemic control with lower insulin doses than did patients who were treated with insulin detemir.