From the Guidelines
GLP-1 receptor agonists can be used in type 1 diabetes mellitus (T1DM) as an adjunct to insulin therapy, though this is considered an off-label use in most countries, with the most recent evidence from 2024 showing modest A1C reductions (0.4%), decreases in weight (5 kg), and reductions in insulin doses 1. When considering the use of GLP-1 receptor agonists in T1DM, it is essential to weigh the potential benefits against the risks. The most recent and highest quality study, published in 2024, demonstrated that liraglutide 1.8 mg daily can improve glycemic control, reduce insulin requirements, and promote weight loss in people with T1DM 1.
Key Considerations
- Typical starting doses are similar to those used in type 2 diabetes, such as liraglutide starting at 0.6 mg daily and titrating up to 1.2-1.8 mg daily.
- Patients should monitor blood glucose closely as insulin doses may need to be reduced by approximately 10-20% initially to prevent hypoglycemia.
- GLP-1 agonists work differently from insulin by slowing gastric emptying, suppressing glucagon secretion, and promoting satiety, which can help address post-meal glucose excursions that are challenging to manage with insulin alone.
- Common side effects include nausea, vomiting, and diarrhea, which typically improve over time.
Important Safety Information
- The use of SGLT2 inhibitors in T1DM is associated with an increased rate of diabetic ketoacidosis, and patients should be closely monitored for symptoms of ketoacidosis, such as dyspnea, nausea, vomiting, and abdominal pain 1.
- The risks and benefits of adjunctive agents continue to be evaluated, with consensus statements providing guidance on patient selection and precautions 1.
Clinical Implications
- GLP-1 receptor agonists may be a useful adjunct to insulin therapy in T1DM, particularly for patients who are struggling to achieve glycemic control or who require high doses of insulin.
- However, these medications do not replace the need for insulin in T1DM, as patients still require basal and bolus insulin for survival.
- Clinicians should carefully consider the potential benefits and risks of GLP-1 receptor agonists in T1DM and closely monitor patients for adverse effects.
From the FDA Drug Label
Not indicated for use in type 1 diabetes mellitus or treatment of diabetic ketoacidosis (1)
The FDA drug label does not support the use of GLP-1 receptor agonists, such as semaglutide, in patients with Type 1 Diabetes Mellitus (Type 1 DM). The label explicitly states that it is not indicated for this use 2, 2.
From the Research
GLP-1 Receptor Agonists in Type 1 Diabetes Mellitus
- GLP-1 receptor agonists have been used off-label in the management of type 1 diabetes mellitus (T1DM) as adjuvant therapies to insulin 3, 4, 5, 6, 7
- Studies have shown that GLP-1 receptor agonists can improve glycemic control, reduce weight, and decrease insulin requirements in patients with T1DM 3, 4
- The use of GLP-1 receptor agonists in T1DM has been associated with significant reductions in HbA1c, weight, and total daily dose of insulin 3, 4
- GLP-1 receptor agonists have also been shown to have beneficial effects on gastric emptying, appetite, and satiety, which can be beneficial for patients with T1DM 5, 6, 7
Efficacy and Safety of GLP-1 Receptor Agonists in T1DM
- A real-world study found that GLP-1 receptor agonist users had statistically significant reductions in weight, HbA1c, and total daily dose of insulin, with a lower risk of diabetic ketoacidosis (DKA) compared to SGLT2 inhibitor users 3
- Another study found that GLP-1 receptor agonists were effective in improving glycemic control, reducing weight, and decreasing insulin requirements in patients with T1DM, with a limited number of gastrointestinal adverse events 4
- However, the use of GLP-1 receptor agonists in T1DM is still not approved, and more studies are needed to fully understand their efficacy and safety in this population 5, 6, 7
Potential Benefits and Risks of GLP-1 Receptor Agonists in T1DM
- The potential benefits of GLP-1 receptor agonists in T1DM include improved glycemic control, weight loss, and reduced insulin requirements 3, 4, 5, 6, 7
- The potential risks of GLP-1 receptor agonists in T1DM include an increased risk of DKA, gastrointestinal adverse events, and hypoglycemia 3, 4
- Further studies are needed to fully understand the benefits and risks of GLP-1 receptor agonists in T1DM and to determine their potential role in the management of this condition 5, 6, 7