NEW HAVEN — Treatment with leptin, the hormone associated with fullness or satiety, reverses hyperglycemia in animal models of poorly controlled Type 1 and Type 2 diabetes by suppressing the neuroendocrine pathways that cause blood glucose levels to soar, a Yale School of Medicine-led team of researchers has found. The study appears in the advance online publication of Nature Medicine.

The leptin hormone regulates metabolism, appetite and body weight. The researchers discovered that, in a fasting state, rats with poorly controlled Type ! and Type 2 diabetes had lower plasma insulin and leptin concentrations and large increases in concentrations of plasma corticosterone — a stress hormone made in the adrenal glands that raises levels of blood glucose.

The researchers then found that normalizing plasma leptin concentrations in the Type 1 diabetes rats with a leptin infusion resulted in marked reductions in plasma glucose concentrations, which could mostly be attributed to reduction in rates of liver conversion of lactate and amino acids into glucose.