Is GLP-1 (Glucagon-Like Peptide-1) good for diabetes?

GLP-1 Receptor Agonists Are Highly Effective for Diabetes Management

GLP-1 receptor agonists are excellent medications for type 2 diabetes, providing significant benefits in glycemic control, cardiovascular protection, and weight reduction, and should be considered as a preferred injectable therapy before insulin for most patients with type 2 diabetes. 1

Mechanism of Action and Benefits

• GLP-1 receptor agonists work through multiple mechanisms to improve diabetes control:

  • Stimulate insulin secretion in a glucose-dependent manner (reducing hypoglycemia risk) 1
  • Suppress glucagon secretion during hyperglycemia 1
  • Delay gastric emptying, which helps control postprandial glucose excursions 1
  • Promote weight loss through reduced appetite and food intake 1, 2
  • May protect beta cells against apoptosis and promote beta cell proliferation 1, 3

• These medications have demonstrated significant clinical benefits beyond glucose control:

  • Reduce rates of non-fatal myocardial infarction, stroke, and death in patients with type 2 diabetes and established cardiovascular disease 1
  • Provide substantial weight loss benefits, which is particularly valuable in the typically overweight/obese type 2 diabetes population 2, 4
  • Have a low risk of hypoglycemia due to their glucose-dependent mechanism of action 1, 4

Types of GLP-1 Receptor Agonists

• GLP-1 receptor agonists are available in different formulations:
  • Short-acting agents (exenatide twice daily, lixisenatide) - better for postprandial glucose control 2
  • Long-acting agents (liraglutide, semaglutide, dulaglutide, exenatide once-weekly) - more effective for fasting glucose and overall HbA1c reduction 1, 2
  • Oral semaglutide - first oral GLP-1 receptor agonist, offering an alternative to injectable therapy 2, 5
  • Dual GIP/GLP-1 receptor agonists (tirzepatide) - newer agents with even greater HbA1c and weight reduction benefits 1, 6

Place in Therapy

• Current guidelines recommend GLP-1 receptor agonists:

  • As a preferred injectable therapy before insulin when oral medications are insufficient 1
  • As a second-line therapy after metformin, particularly in patients with established cardiovascular disease 1
  • In combination with basal insulin when additional glycemic control is needed 1

• The 2024 ADA Standards of Care specifically recommends considering GLP-1 receptor agonists based on:

  • Individual preferences, HbA1c-lowering needs, and weight management goals 1
  • Cardiovascular disease status - those with established cardiovascular disease should receive a GLP-1 RA with proven cardiovascular benefit 1

Important Considerations and Limitations

• Common side effects include:

  • Gastrointestinal symptoms (nausea, vomiting, diarrhea) - typically diminish over time 7, 5
  • Delayed gastric emptying - may affect absorption of other oral medications 1, 7

• FDA-approved indications and limitations:

  • Indicated for improving glycemic control in adults with type 2 diabetes 7
  • Some agents (like semaglutide and liraglutide) are also indicated to reduce cardiovascular risk in patients with established cardiovascular disease 7, 8
  • Not indicated for type 1 diabetes or diabetic ketoacidosis 7
  • Should be used with caution in patients with a history of pancreatitis 7

• Practical considerations:

  • Available in different dosing frequencies (daily to weekly) to accommodate patient preferences 2
  • May be combined with basal insulin in either free or fixed-dose combinations 1, 2
  • Oral semaglutide provides an option for patients with injection concerns 5

Conclusion for Clinical Practice

When managing type 2 diabetes, GLP-1 receptor agonists should be strongly considered after metformin, especially in patients with cardiovascular disease, obesity, or those needing injectable therapy. Their multiple benefits on glycemic control, cardiovascular outcomes, and weight make them valuable tools in diabetes management, with a favorable safety profile compared to many alternatives.