As one of the body’s mechanisms that regulate blood sugar and naturally prevent the onset of diabetes, incretins are a key player. They’re gastrointestinal hormones that are released upon eating, even before blood sugar levels go up. They also slow down the rate at which nutrients are absorbed into the blood and may reduce food intake. In addition, they limit the amount of glucagon hormone released by the pancreas, so it doesn’t cause a blood sugar spike. Two such substances in the body are glucagon-like peptite-1 (GLP-1) and gastric inhibitory peptide (GIP), which are then “kept in check” by the dipeptidyl peptidase-4 enzyme (DPP-4). It has been found that type 2 diabetics don’t have a sufficient supply of incretins. In those cases, the presence of DPP-4 makes the situation worse. For people with diabetes, incretins must be reintroduced into the body to keep the system running correctly.
Incretins and Diabetes: Medicines that Make Use of the Incretin System
To control diabetes, incretins were synthesized and developed. Two types of medications based on the incretin system appeared in 2009 – substances which mimic incretin (similar to the body’s own, but not affected by DPP-4) and DPP-4 inhibitors. The downside of the synthetic GLP-1 is that it must be given by injection (Byetta and Victoza are two examples). The DPP-4 inhibitors can be taken orally (e.g. Januvia, Onglyza).
Incretins in Diabetes: Benefits, Risks, and Alternatives
Among the incretin mimetics, Byetta can lower blood glucose levels along with weight loss benefits, though side effects can include hypoglycemia, nausea, and in rare cases, inflammation of the pancreas. Victoza, longer-acting and more evenly distributed over the course of the day, is perhaps better at controlling blood glucose with less risk of hypoglycemia and other side effects. Exenatide-LAR (taken once a week; otherwise similar to Victoza) was approved for use in the U.S. in January 2012. Among the DPP-4 inhibitors, Januvia lowers hemoglobin A1c levels; side effects can include cold symptoms, allergic reactions, headaches, nausea, stomach pain, diarrhea and swelling in the legs, feet or hands. Onglyza is similar to Januvia in its benefits and side effects, which might also include urinary tract infections and inflammation of the pancreas. Alogliptin also lowers A1c, and side effects include headache, dizziness, constipation, and allergic symptoms. Diabetes incretins should be used only when diet and exercise by themselves aren’t enough. There is increasing evidence that lifestyle changes are sufficient in controlling weight and blood sugar, replacing the need for medication. Begin by removing unhealthy sugars, starches and fats from your diet and instead eat fruits, vegetables, whole grains, nuts, legumes and beneficial oils like olive, peanut and omega-3. Regular exercise is another important part of the equation. With a more health-conscious diet and physical activity to combat diabetes, incretins from synthetic sources may be unnecessary.
