Taking a Shot at Weight Loss

Researchers are touting an injectable weight loss solution, but skeptics remain.

June 8, 2007— -- Is there a better weapon on the way in the battle against the bulge?

A study released today has found that injecting people with a synthetic hormone may help them lose weight and feel satisfied. The hormone, pramlintide, marketed under the name Symlin, is currently used to treat diabetes.

One team of researchers thinks they may have found a new purpose for it.

"We are very intrigued to find that pramlintide can actually have multiple effects on eating behavior, like curbing binge eating," says lead study author Dr. Christian Weyer. Weyer is director of clinical research at Amylin Pharmaceuticals Inc., the San Diego based company that makes Symlin.

But if this treatment sounds too good to be true, that just might be the case. Some leading diet experts say Symlin won't become a weapon in the fat fight anytime soon.

"This is not a convenient treatment," Dr. David Katz, director of the Prevention Research Center at the Yale School of Medicine told ABC News. He cites the fact that users in the study required injections several times a day.

"It's hard enough to get people to take a pill two or three times a day," he said. "Suddenly, weight management has inherited the kind of burden typically associated with insulin-dependent diabetes."

A Jab for Flab?

The study, published in the American Journal of Physiology-Endocrinology and Metabolism, followed 88 obese people for six weeks.

Some were injected with Symlin fifteen minutes before each meal, and others were injected with salt water. Those who received the hormone ate far fewer calories than those who received the placebo.

Part of the study involved a "junk food challenge" where participants had the opportunity to eat pizza, ice cream, and other fatty foods. The Symlin-treated group consumed considerably less junk food.

The researchers report that over the course of the study, the people that received Symlin lost an average of 4.5 pounds.

They also reported feeling full despite eating less.

While most diet pills work by blocking certain chemicals in the brain, the researchers say treatments like Symlin may be easier for people to accept because they use the body's natural pathways that regulate appetite.

"What generally happens with dieting is that you can discipline yourself, but your body typically recognizes that you're eating less, and compensates," says Weyer. "And that's why I think so many diets fail. By giving hormones like pramlintide may actually help dieters to feel like they're not eating less."

Critics Cite Flaws

But while dieters on the drug may feel less hungry, the demanding injection schedule will likely dissuade some.

"I don't foresee a day any time soon when a significant portion of the overweight population is self-injecting multiple times a day," Yale's Katz said.

Also, the cost of such a treatment might be prohibitively high. Weyer says this kind of treatment for weight loss is still in the research process.

In addition, the study followed participants for only six weeks -- a very short time to monitor any real changes in weight loss.

Keith-Thomas Ayoob, associate professor in pediatrics at the Albert Einstein College of Medicine, says that it is possible that the hormone injections caused only part of the weight loss in the study.

"What really happened was that the intervention 'arrested' their ongoing weight gain and seemed to produce a mild reduction, but again, this was only for six weeks," he says. "The drug maker needs to step up and do a study for at least six months."

Still, Weyer thinks that pramlintide represents a real step forward for the science of obesity and appetite.

"There is certainly a need for more innovative and novel ways to treat obesity," he says. "Hormones like pramlintide are one approach to this big problem. Peptide hormones like this one may have a lot of potential not only as effective treatments, but also as safe."