Leptin, a protein hormone that contributes to satiety and insulin sensitivity,1 is reported to normalize blood glucose levels in diabetic rodents. In fact, results related to leptin administration are so promising that a clinical trial involving humans is being developed. Roger Unger, from the University of Texas Southwestern Medical Center in Dallas, and colleagues administered leptin to type 1 diabetic rats who had received islet cell pancreatic transplants. The administration of leptin led to better regulation of blood glucose levels than was seen in the transplant recipients who received insulin.
Initially skeptical of their findings, the researchers further tested the association between leptin and blood glucose levels. They implanted a pump in 15 diabetic mice and administered high levels of leptin for 12 days. Then, comparing the experimental animals' glucose levels with that of diabetic mice treated with insulin delivered through the same type of implanted pumps, the glucose levels in both groups returned to normal. The researchers explain the impact leptin has on blood glucose levels: leptin curbs production of glucagon; as glucagon levels decrease, the release of glucose from the glycogen stored in the liver is suppressed and blood sugar levels are reduced.
Treatment of type 1 diabetics with leptin holds much promise. Leptin has additionally been reported to decrease the fluctuations in blood glucose levels in type 1 diabetics more effectively than insulin. One concern is that leptin does significantly decrease the appetite. Weight loss is a concern in type 1 diabetics. In response to this issue, the researchers reported that, over the long term, the body weights of mice receiving leptin were not significantly less than those receiving insulin. To further understand the potential use of leptin to treat type 1 diabetics, the researchers are developing a clinical trial to test the a combination of leptin and insulin in humans. The addition of leptin as a mechanism to regulate blood glucose could potentially decrease the long term complications of insulin use and of type 1 diabetes.
Source: Couzin-Frankel J. Appetite suppressor could be an alternative to insulin. ScienceNow. March 1, 2010. Available athttp://news.sciencemag.org/sciencenow/2010/03/appetite-suppressor-could-be-an-.h. Accessed onMarch 10, 2010.
Submitted by: Robin Pattillo, PhD, RN, News Editor at[email protected].
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