When blood sugar levels rise in healthy people, insulin signals cells to increase production: Study

February 16, 2016

Answering that question was no small feat. Joslin clinical researchers enlisted healthy volunteers and measured their insulin production under normal conditions. Then, under very careful control, the subjects received a human analog of insulin along with glucose via intravenous injections, with the investigators coordinating the doses to maintain normal glucose levels. Next the scientists upped the amounts of glucose and monitored the additional production of insulin??and found, indeed, that insulin production climbed faster when higher levels of insulin already were present.

The tests required careful use of assays that could differentiate between the administered insulin analog and insulin generated by the body. The scientists also did exhaustive studies that appeared to rule out other possible mechanisms for the boost in insulin production.

To follow up, the Joslin clinical research team will study whether this insulin signaling mechanism appears damaged in people who manifest early insulin resistance, a condition that leads toward type 2 diabetes.

"We've shown that insulin has a positive effect on its own secretion," says Dr. Kulkarni. "Our hypothesis now is that blunting of this positive effect in susceptible individuals may lead to a molecular cascade that eventually leads to poor function of the beta cells and then to type 2 diabetes."

If that hypothesis turns out to be correct, he says, it may offer opportunities to create new kinds of drugs for diabetes prevention and treatment.

SOURCE Joslin Diabetes Center