Numerous medications are available for the treatment of type 2 diabetes mellitus but a fairly new class of medications are now on the market that not only improve glucoses and Hemoglobin A1c’s (HbA1c) but also promote weight loss and may help to protect the body’s insulin-producing cells.
Glucagon-like peptide-1 (GLP-1) related medications are injectable treatments for type 2 diabetes but are NOT insulin. GLP-1 occurs naturally and is released from the intestine when nutrients are present. It then stimulates insulin secretion from the pancreas and inhibits the release of glucagon, both of which cause glucose levels to decrease. Byetta® (Exenatide) is presently the only GLP-1-related medication on the market; however, numerous others are in clinical trials at this time. Byetta® is indicated for use in people with type 2 diabetes mellitus who are taking other oral medications to treat diabetes but have not achieved adequate glucose control. Byetta® is presently given by twice daily subcutaneous injection, using a pen device. Though this is nearly identical to insulin delivery methods, Byetta® is very unlike insulin in its dosing. It comes in only two doses—5 and 10 micrograms—while insulin dosing is nearly infinite, with almost every patient having a different dose. GLP-1 related treatments help to lower glucoses and have been shown to promote weight loss. They work in five ways to accomplish this:
- Signaling the pancreas to release insulin
- Stopping the liver from making glucose
- Slowing how quickly the stomach empties food and glucose which helps to keep glucose levels lower after eating and causes you to feel full after a small meal
- Telling the appetite center in the brain you are full
- Decreasing the body’s production of glucagon (a hormone that raises glucose level)
Hypoglycemia is NOT a side effect of GLP-1 therapy. If hypoglycemia occurs, it is most likely due to the sulfonylurea medication you may also be taking, such as:
- Glipizide
- Glimepiride
- Glyburide
As we already discussed, weight loss is a common therapeutic effect of GLP-1 treatment. The potential weight loss and the lack of hypoglycemia make this a very attractive treatment option; I commonly attempt this therapy before moving on to insulin. The most common side effects are gastrointestinal in origin and include:
- Nausea
- Vomiting
- Diarrhea
This therapy should not be used in people with:
- Reduced kidney function
- Certain gastrointestinal problems
The other big advantage of GLP1 therapy is that studies suggest GLP-1 may help to preserve the pancreas’s insulin producing beta cells and protect them from death that typically occurs over time in most people with type 2 diabetes. This could delay or prevent the need for insulin therapy that commonly occurs in type 2 diabetes.
