Once-daily Initiation of Basal Insulin As Add-on to Metformin: a 26-week, Randomized, Treat-to-target Trial Comparing Insulin Detemir with Insulin Glargine in Patients with Type 2 Diabetes

Aims: This study assessed the efficacy and safety of once-daily insulin initiation using insulin detemir (detemir) or insulin glargine (glargine) added to existing metformin in type 2 diabetes (T2D).

Methods: This 26-week, multinational, randomized, treat-to-target trial involved 457 insulin-naïve adults with T2D (HbA1c 7-9%). Detemir or glargine was added to current metformin therapy [any second oral antidiabetic drug (OAD) discontinued] and titrated to a target fasting plasma glucose (FPG) ≤90 mg/dl (≤5.0 mmol/l). Primary efficacy endpoint was change in HbA1c.

Results: Mean (s.d.) HbA1c decreased with detemir and glargine by 0.48 and 0.74%-points, respectively, to 7.48% (0.91%) and 7.13% (0.72%) [estimated between-treatment difference, 0.30 (95% CI: 0.14-0.46)]. Non-inferiority for detemir at the a priori level of 0.4%-points was not established. The proportions of patients reaching HbA1c ≤ 7% at 26 weeks were 38% and 53% (p = 0.026) with detemir and glargine, respectively. FPG decreased ∼43.2 mg/dl (∼2.4 mmol/l) in both groups [non-significant (NS)]. Treatment satisfaction was good for both insulins. Hypoglycaemia, which occurred infrequently, was observed less with detemir than glargine [rate ratio 0.73 (95% CI 0.54-0.98)]. The proportions of patients reaching HbA1c ≤ 7% without hypoglycaemia in the detemir and glargine groups were 32% and 38% (NS), respectively. Weight decreased with detemir [-0.49 (3.3) kg] and increased with glargine [+1.0 (3.1) kg] (95% CI for difference: -2.17 to -0.89 kg).

Conclusion: While both detemir and glargine, when added to metformin therapy, improved glycaemic control, glargine resulted in greater reductions in HbA1c, while detemir demonstrated less weight gain and hypoglycaemia.