By: Russell Phillips
Onglyza (saxagliptin), a dipeptidyl peptidase-4 (DPP-4) inhibitor produced by AstraZeneca and Bristol-Myers Squibb, has been approved by the US Food and Drug Administration (FDA) for the treatment of type 2 diabetes.
So what exactly are DPP-4 inhibitors, and how do they help people with type 2 diabetes? DPP-4 inhibitors, like Januvia and now Onglyza, stabilize blood glucose levels by increasing insulin production and decreasing glucose production. As their name would suggest, they manage this by inhibiting DPP-4. When DPP-4 is its usual uninhibited self, it breaks down incretins, which are a group of hormones in the gastrointestinal system. Conversely, when DPP-4 is inhibited, the level of incretins rises. A higher level of incretins is a good thing. Why? Because incretins increase the release of insulin into the blood after a meal even before glucose levels rise, and inhibit the release of glucagon, a hormone that is produced by the pancreas when blood glucose is low. Inhibiting the release of glucagon is also a good thing. Again, why? Because glucagon raises the level of glucose in the blood by causing the liver to convert glycogen to glucose.
Let’s put it another way; inhibiting DPP-4 increases incretins, which decrease glucagon release, and increases insulin which then decreases glucose. Make sense? Now say it three times fast. Now say it backwards.
For a more detailed explanation of DPP-4 inhibitors and incretins, read The Incretin Saga: Mimetics, Enhancers, and Inhibitors.