Leptin, a hormone discovered in 1994 by Rudolph L. Leibel, is produced by fat cells. Leptin plays an important role in regulating appetite and in glucose and fat metabolism. Its discovery pioneered the concept that adipose tissue is not a silent energy-storage organ, but actually an active endocrine organ. The discovery of leptin generated great excitement that a treatment for obesity may have been found. Subsequent clinical trials, however, led to initial disappointment, when they demonstarted that leptin was ineffective for the treatment of obesity. Many potential small applications for leptin have been found, such as in the case for people with relative acquired leptin deficiency that can seen in anorexia nervosa, exercise induced hypothalamic amenorrhea, and HIV lipoatrophy.
Now, a new study published online in the Proceedings of the National Academy of Sciences suggests leptin may be making a comeback. Researchers at the University of Texas Southwestern Medical Center conducted a Phase 1 study in mice which showed that leptin can take the place of insulin in treating the symptoms of Type 1 diabetes. The scientists administered leptin instead of insulin to diabetic mice and found the therapy was successful at managing blood-sugar levels. While it is far too early to know whether leptin therapy will work in humans, the results of this study imply that leptin administration may have multiple short- and long-term advantages over insulin monotherapy for type 1 diabetes.