Study Suggests Caution Needed When Using Premixed Insulin in the Hospital

New study suggests that in hospital patients with T2DM, premixed insulin provides similar glycemic control as a basal-bolus insulin regimen.

In the outpatient setting for the management of T2DM, premixed insulin is a commonly prescribed formulation. However, the safety and efficacy of the same formulation for inpatient type 2 diabetics is unknown. Therefore, researchers conducted a study to identify these factors.

Researcher Virginia Bellido conducted a randomized prospective open-label study. Researchers analyzed 72 patients who were 18 years old or greater with a diagnosis of T2DM. These patients presented to general medicine and surgery services and they were randomly assigned to either a basal-bolus regimen (insulin glargine) once-daily and Apidra (insulin glulisine) before meals (n=33) or a premixed human insulin regimen with 30% regular insulin and 70% Mixtard 30 (NPH insulin) twice daily (n=39). Endpoints were mean capillary daily blood glucose during each day.

It was found that mean capillary blood glucose levels were comparable between basal-bolus and premixed insulin groups at admission (203.1 mg/dL vs. 221.3 mg/dL). Furthermore, similar immediate and long-term improvements in mean daily blood glucose were observed in both groups (175 mg/dL vs 179 mg/dL). There were no differences between mean, fasting, pre-meal or postprandial measurements. In addition, no differences were seen between groups with glucose measures between 80-180 mg/dL (55.9% vs. 54.3%).

Authors believe that an increased incidence of hypoglycemia is associated with premixed insulin regimen as a planned interim analysis displayed this effect. This finding exceeded the pre-specified stopping rule of 50% in the mixed insulin group and the trial was stopped early. Hypoglycemia in the basal-bolus vs. mixed insulin was 8 patients (24.2%) vs. 25 patients (64.1%) respectively. Nonetheless, authors caution the use of premixed human insulin in the management of T2DM in general medicine and surgery patients.

Practice Pearls:

• Premixed insulin regimen provides similar glycemic control as a basal-bolus insulin regimen; however, it results in significantly higher incidence of hypoglycemia.
• Caution should be used when using premixed human insulin to manage T2DM in the general medicine and surgery settings.
• No differences are observed in either premixed insulin or basal-bolus regimen with respect to average, fasting, pre-meal, and postprandial levels.

Bellido, Virginia, et al. “Comparison of Basal-Bolus and Premixed Insulin Regimens in Hospitalized Patients With Type 2 Diabetes.” Diabetescare, (Oct122015):dc150160.