Hormone Outperforms Insulin in Diabetic Mice
Someday, leptin could free people with type 1 disease from daily injections, expert predicts
MONDAY, March 1, 2010 (HealthDay News) -- Researchers are reporting that treatment with a hormone linked to weight loss seems to control type 1 diabetes in mice better than insulin does, raising the prospect of a landmark new treatment for some human diabetics.
There's no guarantee that the hormone, known as leptin, will work against type 1 diabetes. But if leptin has similar effects on humans, it could free type 1 diabetics from their daily regimen of multiple insulin injections and tight blood-sugar monitoring, said the study's co-author, Dr. Roger Unger, chairman of diabetes research at the University of Texas Southwestern Medical Center at Dallas.
In addition, Unger said, leptin could help diabetics do a better job of controlling their blood sugar. "They would have a longer life as well as a less burdensome one," he said. "That's the best possible scenario that we could hope for."
People with type 1 diabetes -- also known as juvenile diabetes -- are reliant on insulin, which has been the main treatment since the early part of last century. "Insulin was discovered in 1922 and prevented death, and all of us have grown up having been taught that that was a miraculous discovery, which is correct," Unger said.
But the problem is that injected insulin causes health problems of its own in the body. Type 1 diabetics have little leeway for error in how they treat their condition, and they are at high risk for heart disease as a result of insulin, Unger said.
Leptin is a hormone that's been linked to weight loss, and previous research has suggested that it could help people with type 2 diabetes, the most common form of the disease.
In the new study, researchers gave leptin, insulin or both to mice with type 1 diabetes. The researchers found that the mice treated with leptin alone or in conjunction with insulin did better: Their blood sugar didn't fluctuate as much, their cholesterol levels went down and they didn't form as much body fat.
Unger said that leptin seems to do a better job than insulin at targeting the body's blood-sugar control mechanisms.
The findings were published in this week's online issue of the Proceedings of the National Academy of Sciences.
Another diabetes expert, Satya P. Kalra, a distinguished professor emeritus at the University of Florida Department of Neuroscience, said that his own research has shown that leptin works as a treatment for both kinds of diabetes. In fact, leptin is "the only durable and efficient new therapeutic strategy for diabetes" and related diseases, said Kalra, who's familiar with the findings of the new study.
What's next? Leptin must be tested on humans, Unger said. "We have every reason to believe that it will work in man," leading to better health for diabetics, he said. "But there's no point in getting overly excited until a human trial has shown that it works, and that will take a couple of years."
Unger said he could not estimate the cost of leptin therapy. It could be given through injections or via an intravenous drip, he said.
Learn more about type 1 diabetes from the American Diabetes Association.