Mixing Insulin Lispro and Insulin Glargine in Young Adults with Type 1 Diabetes
How Does It Change Serum IL?
On May 7, 2012, a type 1 diabetes study was published online ahead of appearing in the journal Pediatric Diabetes; the article is titled “A 12-wk follow-up study to evaluate the effects of mixing insulin lispro and insulin glargine in young individuals with type 1 diabetes.” The study compared the effects of a mixture of insulin lispro (IL) and insulin glargine (IG) on glycemic control, and the subjects were young adults with type 1 diabetes.
The researchers were looking specifically at how in real life, the IL serum profile is affected after a subcutaneous (SC) injection—both alone and mixed with IG. They used a sensitive radioimmunoassay for determining the serum IL. Additionally, the researchers were looking at the effect on glycemic control the IL/IG mixture had after 12 weeks.
This was a small study involving 10 individuals with type 1 diabetes. Their age was 21.9 ± 3.8 years, and the duration of diabetes was 13.4 ± 4.9 years. Body mass index of the subjects was 25.1 ± 3.2 kg/m2; hemoglobin A1c (A1c) was 8.3 ± 0.8%.
The young adults’ IL serum profiles were evaluated during a mixed meal test (MMT)—both using IL and IG as separate injections and as mixed injections. Continuous glucose monitoring (CGM) was used to evaluate glycemic variability at baseline and after 12 weeks; A1c was also measured at baseline and 12 weeks.
Mixing IL and IG decreased IL maximum serum concentrations (Cmax(IL)) (29.4 ± 5.1 µU/mL); this is in comparison to not mixing them (Cmax(IL) = 13.7 ± 4.2 µU/mL (p = 0.03). This did not change the time to reach Cmax (Tmax(IL)), nor did it change the IL area under the curve (AUC(IL) (0-240) or the glucose dynamics during MMT.
Glucose variability and A1c were equivalent to the baseline at the 12-week mark after mixing the insulins.
The researchers conclude that their study suggests that for people with type 1 diabetes, it’s possible to mix IL with IG immediately before subcutaneous injection—without affecting the glycemic profile after 12 weeks. Mixing IL and IG decreases IL serum peak concentrations.