Introduction: Premixed insulin analogs represent an alternative to basal or basal-bolus insulin regimens for the treatment of type 2 diabetes (T2D). "Low-mix" formulations with a low rapid-acting to long-acting analog ratio (e.g., 25/75) are commonly used, but 50/50 formulations (Mix50) may be more appropriate for some patients. We conducted a systematic literature review to assess the efficacy and safety of Mix50, compared with low-mix, basal, or basal-bolus therapy, for insulin initiation and intensification.
Methods: MEDLINE, EMBASE, Cochrane Database of Systematic Reviews, ClinicalTrials.gov, LillyTrials.com, and NovoNordisk-trials.com were searched (11 or 13 Dec 2016) using terms for T2D, premixed insulin analogs, and/or Mix50. Studies (randomized, nonrandomized, or observational; English only) comparing Mix50 with other insulins (except human) and reporting key efficacy [glycated hemoglobin (HbA1c), fasting and postprandial glucose] and/or safety (hypoglycemia, weight gain) outcomes were eligible for inclusion. Narrative reviews, letters, editorials, and conference abstracts were excluded. Risk of bias in randomized trials was assessed using the Cochrane tool.
Results: MEDLINE and EMBASE searches identified 716 unique studies, of which 32 met inclusion criteria. An additional three studies were identified in the other databases. All 19 randomized trials except one were open label; risk of other biases was generally low. Although not conclusive, the evidence suggests that Mix50 may provide better glycemic control (HbA1c reduction) and, particularly, postprandial glucose reduction in certain patients, such as those with high carbohydrate diets and Asian patients, than low-mix and basal therapy. Based on this evidence and our experience, we provide clinical guidance on factors to consider when deciding whether Mix50 is appropriate for individual patients.
Conclusions: Mix50 may be more suitable than low-mix therapy for certain patients. Clinicians should consider not only efficacy and safety but also patient characteristics and preferences when tailoring insulin treatment to individuals with T2D.
Funding: Eli Lilly.
Keywords: Biphasic insulin; Diabetes mellitus; Insulin aspart; Insulin lispro; Practice guideline; Systematic review; Type 2.