Can Type 2 Diabetes Medications Treat Type 1 Patients?

A whopping 22 million people worldwide have Type 1 diabetes (T1DM). Insulin therapy, while necessary, is associated with more than 40 hypoglycemic episodes annually for the average T1DM patient, and can lead to weight gain, which increases cardiovascular risks.

Roughly two thirds of adults with T1DM exceed the American Diabetes Association’s general HbA1C goal of ≤7%. An October 2015 article in the journal Endocrine Practice reviewed the current evidence for using non-insulin adjunctive therapy in T1DM.

Researchers searched PubMed databases, and abstracts from recent diabetes meetings for the term “type 1 diabetes” and the names of several available and investigational medications. These included sodium-glucose transporter (SGLT) inhibitors, glucagon-like peptide 1 (GLP-1) receptor agonists, dipeptidyl peptidase 4 (DPP-4) inhibitors, and metformin. Here are some highlights of their review:

SGLT2 Inhibitors. In a 28-day phase 2 trial of 75 T1DM patients, empagliflozin significantly reduced HbA1C, hypoglycemia, total daily insulin dose, and weight when compared with placebo. However, a series of case studies report an increased risk of euglycemic diabetic ketoacidosis with canagliflozin, perhaps due to glycosuria-associated dehydration.

SGLT1 Inhibitors. A 29-day placebo-controlled trial of sotagliflozin, a dual SGLT1/SGLT2 inhibitor, in 33 T1D patients significantly lowered postprandial blood glucose and reduced total daily insulin requirements. Compared with insulin and placebo, insulin and sotagliflozin caused less hypoglycemia, but more nausea.

GLP-1 Receptor Agonists. A 1.2 mg dose of GLP-1 receptor agonist liraglutide showed good outcomes in a 12-week, phase 2, placebo-controlled trial of 72 T1DM patients. It significantly reduced HbA1C, weight, and total daily insulin dose. However, patients enrolled in the study's other arm (liraglutide 1.8 mg) had no significant HbA1c reductions.

DPP-4 Inhibitors. DPP-4 inhibitors created short-term glucose improvements, but they were not been sustained in longer studies.

Metformin. Metformin has been linked to lower weight, insulin dose, and HbA1c, though a meta-analysis of these studies challenged the significance of the A1C reductions. A study scheduled to finish in 2016 may provide further evidence.

Supplementing insulin therapy combined with other glucose lowering agents may improve outcomes for T1DM patients. Several trials in progress will provide further insights.