The impact of the timing of Humalog Mix25 injections on blood glucose fluctuations in the postprandial period in elderly patients with type 2 diabetes.

Background: Postprandial hyperglycemia contributes to glycation of hemoglobin A1c and has been associated with cardiovascular risk in people with diabetes. We investigated the impact of injection timing of Humalog Mix25 (Mix25, known as Humalog Mix75/25 in the U.S.: 25% insulin lispro and 75% neutral protamine lispro) on glycemia and postprandial blood glucose (BG) excursions in elderly individuals

Material/methods: Seventy-three patients aged 60 to 80 years were randomized to Mix25 (Mix25 group, 37 participants) or a continuation with maximum dose glibenclamide (control group, 36 participants). The Mix25 group was subdivided into a group of 18 patients who were injecting insulin after meals and 19 who were injecting before.

Results: At baseline, the absolute postprandial BG concentrations and postprandial BG excursions after breakfast were high (Mix25 group: 15.3+/-4.8 mmol/l and 3.5+/-2.7 mmol/l, respectively; controls: 15.4+/-3.9 mmol/l and 4.7+/-2.7 mmol/l, respectively). In both groups improvement was observed at the endpoint, but it was greater with Mix25 (Mix25 group: 10.3+/-3.6 mmol/l, p<0.0001 vs. baseline, p<0.003 vs. controls, and 2.0+/-2.5 mmol/l, p<0.008 vs. baseline, p=ns vs. controls; control group: 13.3+/-2.9 mmol/l, p<0.006 vs. baseline, and 4.7+/-2.7 mmol/l, p<0.006 vs. baseline). The two Mix25 subgroups had similar postprandial BG levels and BG excursions after breakfast.

Conclusions: Mix25 improves postprandial BG and yields a greater effect on BG excursions compared with monotherapy with glibenclamide. The timing of Mix25 did not impact the level of BG or BG fluctuations after meals, which may be important for individuals with changing dietary pattern.