Durability of glycemic control with insulin lispro mix 75/25 versus insulin glargine for older patients with type 2 diabetes

Few studies have evaluated long-term durability of glycemic control in older patients. The aim of this study was to compare durability of glycemic control of twice-daily insulin lispro mix 75/25 (LM75/25; 75 % insulin lispro protamine suspension, 25 % insulin lispro) and once-daily insulin glargine (GL) added to oral antihyperglycemic medications in older patients (≥65 years of age).

Patients were participants in the maintenance phase of the DURABLE trial. During the initiation phase, patients with type 2 diabetes were randomized to LM75/25 or GL. After 6 months, patients with hemoglobin A1c (HbA1c) ≤7.0 % advanced to the 24-month maintenance phase. The primary objective was between-group comparison of duration of maintaining the HbA1c goal in older patients (≥65 years of age). A similar analysis was conducted for older patients achieving HbA1c ≤6.5 % in the initiation phase.

Median time of maintaining HbA1c goal was longer in LM75/25 versus GL (19.6 versus 15.4 months, p = 0.007) and more LM75/25 patients maintained goal versus GL (49.2 versus 30.4 %; p = 0.003). HbA1c reduction from baseline was greater in LM75/25 versus GL (-1.56 ± 0.10 versus -1.24 ± 0.11 %; p = 0.003). Post-meal glucose was significantly lower in LM75/25 versus GL (158.86 ± 3.42 versus 171.67 ± 4.51 mg/dL; p = 0.017). No differences were observed in overall and severe hypoglycemia. LM75/25 patients had higher daily insulin doses (0.41 ± 0.02 versus 0.32 ± 0.02 units/kg/day; p < 0.001) and more weight gain (5.47 ± 0.49 versus 3.10 ± 0.53 kg; p = 0.001). Similar results were generally obtained in older patients with HbA1c ≤6.5 %.

In our evaluation of older patients from a larger trial, LM75/25 appeared to provide longer durability of glycemic control, as well as a greater number of patients maintaining HbA1c goal versus GL.