Basal insulin analogues do not produce substantially different glucose-lowering effects in adults with Type 2 diabetes, according to a new study published in Annals of Internal Medicine. Furthermore, evidence gathered in the study suggests that certain insulin regimens may be associated with less weight gain or lower risk for nocturnal hypoglycemia.

Researchers used data from a number of databases from their inception, information from ClinicalTrials.gov, references of reviews, and several meeting abstract books to conduct a meta-analysis and systematic review. The focus of the study was to compare the safety and efficacy of insulin analogues in adult patients with Type 2 diabetes.

The study included 39 trials, with a total of 26,195 patients and studied 10 different basal insulin analogues. The team included only randomized trials lasting 12 weeks or more, and those that measured hypoglycemia, weight, and HbA1c.

For inclusion, the trials must have compared efficacy by evaluating the change in hemoglobin A1c (HbA1c) level from baseline as the primary outcome, and change in body weight as the secondary outcome. The included studies also assess the safety of basal insulin analogues by tracking hypoglycemia and nocturnal hypoglycemia.

Two of the study authors independently extracted data from the trials, and assessed each outcome for risk of bias. The team of authors evaluated the overall confidence in the evidence included in the study.

Systematic review comparing the benefits and risks of insulin analogues for Type 2 diabetes

The team found that, based on low- to very low-quality evidence, degludac three times per week was inferior to degludac 100 U/mL and glargine 300 U/mL when it came to lowering HbA1c levels.

When it came to the weight-lowering effects of the analogue insulins, high-to-moderate quality evidence showed that detemir was favorable compared with all the other insulins. The results of the study show that, as compared with glargine, glargine 300 U/mL leads to less weight gain.

Very low-quality and low-quality evidence from the study suggested a lower incidence of nocturnal hypoglycemia were associated with glargine 300 U/mL, degludac 100 U/mL, and degludac 300 U/mL as compared with detemir, neutral protamine lispro (NPL), Glar-100, and LY2963016.

The results of the study showed no difference in severe hypoglycemia among the regimens, except NPL, which was associated with a higher risk for severe hypoglycemia than detemir, Deg-100, Glar-100, and Glar-300.

The study is limited in that the researchers base the results primarily on indirect comparisons. The low or very low confidence in summary estimates is the result of individual-study limitations, inconsistency, or imprecision.

"Low-quality indirect evidence suggests that available basal insulin analogues for [Type 2 diabetes] do not substantially differ in their glucose-lowering effects. Certain regimens may be associated with lower risk for nocturnal hypoglycemia or less weight gain," the authors write. "In addition to short-term efficacy and safety, effects on individual drugs on long-term cardiovascular outcomes and cost-effectiveness data should be considered for optimal therapeutic decision making."