A single injection of a hormone that may target brain circuits involved in regulating blood glucose levels leads to sustained diabetes remission in mice and rats, according to a paper published online this week in Nature Medicine. Although the one-time treatment was successful only in rodents with mild forms of diabetes, and its exact mechanism is unknown, it involves a hormone that occurs naturally in the human brain, suggesting that the findings could potentially be translated into a treatment for diabetes in the clinic.

Type 2 diabetes is marked by pathologically elevated levels of blood glucose. Earlier research has shown that injection of fibroblast growth factor 1 (FGF1), a hormone involved in numerous biological processes, into the peripheral blood system has strong antidiabetic effects in mice. However, a potent dose and repeated injections were required to achieve these effects, and this method did not achieve durable remission.

Michael Schwartz and colleagues found that a single injection of FGF1 into the brains of mice or rats with type 2 diabetes normalized the animals’ blood glucose levels for at least the next four months. This antidiabetic effect occurred independently of a persistent change in food intake or body weight, which indicates that the improvement in blood sugar levels was independent of weight loss. The treatment worked in both dietary and genetic models of obesity in mice and in a genetic model of type 2 diabetes in rats.

These results suggest that the brain can strongly influence blood glucose signaling throughout the body. The authors note, however, that injection of FGF1 may lead to structural changes in the brain that need to be explored in future studies.