As most of us know, diabetes is a progressive disease that can be caused by insulin resistance, lack of insulin production, or both! Type 1 diabetes is
typically autoimmune and characterized by a complete lack of endogenous
insulin production by the beta cells. Type 2 diabetes is more often caused by
insulin resistance and subsequent “burnout” of the insulin producing beta
cells. All diabetics can suffer from insulin resistance, and most type 2 medications are made specifically to fight this, but they are not approved for people with type 1. Why? Because apparently the “governing bodies” think of type 2 and type 1 as black and white with no crossover… don’t get me started.
I previously talked about SGLT2-inhibitors, oral medication that can help reduce insulin requirements, but this is not the only type 2 medication that can benefit an insulin resistant type 1.
Glucagon-like peptide-1 receptor agonists (GLP-1 RA) are incretin-based therapies used in type 2 diabetes that have been known to decrease blood glucose levels with minimal amounts of hypoglycemia and increased weight loss. They primarily work on insulin resistance and are effective in control.
Here is how they work…
Glucagon-like peptide-1 (GLP-1) is produced by special cells in the digestive tract in response to nutrients which helps to lower blood glucose levels by enhancing the production of insulin and decreasing the production of glucagon. Though a GLP-1 will not enhance insulin production in a type 1, the mentioned decrease in glucagon production can be highly effective. In type 2’s, GLP-1 also helps to replenish insulin stores in the beta cells, preventing their exhaustion during insulin secretion and therefore preserving their function. As you can imagine, GLP-1 RAs are awesome type 2 meds, but could be great for all types of diabetes because they slow gastric emptying, reduce post-meal spikes, and decrease appetite.
Additionally, some GLP-1 RAs have been associated with a decreased risk of cardiovascular mortality, non-fatal heart attacks, and non-fatal strokes. For those of you who don’t know, the number one cause of mortality in type 2 diabetes is cardiovascular disease, so this is a big plus! This, however can also apply to type 1 patients, especially those struggling with metabolic syndrome (obesity, elevated cholesterol, elevated blood pressure).
All GLP-1 RAs are injectable and are used anywhere from three times daily to once weekly. They are indicated for type 2 diabetes and Saxenda (once daily) is also indicated for obesity, so if you’re type 1 and have a BMI of greater than 30%, this medication could be approved by your insurance. Symlin is the only GLP-1 RA FDA-approved for type 1, but it is not often as often prescribed/used because it is required three times daily and is essentially doubling the amount of injections required by the patient.
Now let’s talk about some possible adverse effects…
The most common side effects of GLP-1 RAs are injection site reactions, nausea and diarrhea (because of the slowed gastric emptying). This usually resolves after a few weeks and many clinicians start the drug at a low dose (and titrate up) to help decrease or prevent these side effects. When used in conjunction with insulin or a sulfonylurea, there is potential for hypoglycemia, so these drugs may need to be adjusted. Rare side effects include pancreatitis (inflammation of the pancreas) and an increased risk of medullary thyroid CA; however, research has shown these to be very rare and unlikely.
Though not yet FDA-approved, there is potential for these medications to be highly effective in both newly diagnosed and longstanding type 1’s, especially in relation to body weight management. If you are interested, I encourage you to talk with your clinician about the risk/benefits of GLP-1 therapy. We need all the help we can get!