When to use GLP-1 (Glucagon-like peptide-1) versus Insulin in diabetes management?

From the Guidelines

GLP-1 receptor agonists are generally preferred over insulin therapy for patients with type 2 diabetes who have not achieved adequate control with metformin, due to their benefits on weight and cardiovascular risk factors 1.

Key Considerations

• Disease duration and glycemic control: GLP-1 receptor agonists are often preferred for patients with type 2 diabetes who have not achieved adequate control with metformin, while insulin therapy is reserved for patients with more severe hyperglycemia or those who require more precise glucose control 1.
• Comorbidities: Patients with comorbidities such as cardiovascular disease may benefit from GLP-1 receptor agonists, which have been shown to reduce cardiovascular risk factors 1.
• Typical doses: GLP-1 receptor agonists such as liraglutide (Victoza) are typically initiated at doses ranging from 0.6 to 1.2 mg/day and titrated to achieve a target dose of 1.2 to 1.8 mg/day, while basal insulin glargine (Lantus) is typically initiated at 10 units/day and titrated to achieve a fasting glucose target 1.

Benefits of GLP-1 Receptor Agonists

• Weight loss: GLP-1 receptor agonists have been shown to promote weight loss, which can be beneficial for patients with type 2 diabetes 1.
• Cardiovascular benefits: GLP-1 receptor agonists have been shown to reduce cardiovascular risk factors, including blood pressure and lipid levels 1.

Insulin Therapy

• Reserved for severe hyperglycemia: Insulin therapy is often reserved for patients with more severe hyperglycemia or those who require more precise glucose control 1.
• Basal insulin: Basal insulin glargine (Lantus) is typically initiated at 10 units/day and titrated to achieve a fasting glucose target 1.

From the FDA Drug Label

OZEMPIC is a glucagon-like peptide 1 (GLP-1) receptor agonist indicated as: • an adjunct to diet and exercise to improve glycemic control in adults with type 2 diabetes mellitus (1). • to reduce the risk of major adverse cardiovascular events in adults with type 2 diabetes mellitus and established cardiovascular disease (1)

Not indicated for use in type 1 diabetes mellitus or treatment of diabetic ketoacidosis (1).

Hypoglycemia: When OZEMPIC is used with an insulin secretagogue or insulin, consider lowering the dose of the secretagogue or insulin to reduce the risk of hypoglycemia (5.5).

GLP-1 (e.g., semaglutide) versus Insulin:

• Use GLP-1 as an adjunct to diet and exercise to improve glycemic control in adults with type 2 diabetes mellitus.
• Use Insulin for type 1 diabetes mellitus or treatment of diabetic ketoacidosis.
• When using GLP-1 with insulin, consider lowering the dose of insulin to reduce the risk of hypoglycemia 2.

From the Research

GLP-1 versus Insulin in Diabetes Management

The decision to use GLP-1 (Glucagon-like peptide-1) versus insulin in diabetes management depends on several factors, including the patient's individual needs, medical history, and treatment goals.

• GLP-1 Receptor Agonists: GLP-1 receptor agonists are a class of injectable glucose-lowering agents that have been shown to be effective in reducing HbA1c levels, promoting weight loss, and improving cardiovascular risk markers 3, 4, 5, 6, 7.
• Mechanisms of Action: GLP-1 receptor agonists work by augmenting hyperglycemia-induced insulin secretion, suppressing glucagon secretion, decelerating gastric emptying, and reducing calorie intake and body weight 3.
• Comparison to Insulin: GLP-1 receptor agonists have been shown to have a similar or superior effectiveness to insulin in reducing HbA1c levels, with the added benefits of weight loss and a lower risk of hypoglycemic episodes 3, 5.
• Patient Selection: The choice between GLP-1 and insulin should be based on individual patient factors, such as the presence of cardiovascular disease, kidney disease, or other comorbidities, as well as patient preferences and lifestyle 4, 6.
• Combination Therapy: GLP-1 receptor agonists can be used in combination with insulin, particularly basal insulin, to achieve better glycemic control and improve treatment outcomes 3, 5.
• Side Effects and Tolerability: GLP-1 receptor agonists are generally well-tolerated, with gastrointestinal and injection-site reactions being the most common adverse events, while insulin therapy is associated with a higher risk of hypoglycemia and weight gain 4, 7.