April 23, 2004 -- Move over, leptin. Researchers have discovered another fat hormone that may aid in promoting weight loss.
A new study suggests that the hormone adiponectin, which is found in fat tissue, can cause weight loss by boosting metabolism without affecting appetite. Researchers say that the finding may lead to better treatments for obesity and other metabolic disorders, such as diabetes.
Leptin, a related fat hormone, has been widely studied in recent years and has been shown in to produce weight loss in animals by decreasing appetite and increasing metabolism.
Researchers say both fat hormones work through the same pathway in the brain to control body weight and blood sugar (glucose). But these hormones may also control metabolism though other unique ways, and learning more about how they work may lead to more effective anti-obesity treatments.
Fat Hormone Boosts Metabolism
In the study, published in the April issue of Nature Medicine, researchers injected adiponectin into normal laboratory mice. They found that the mice lost weight even though the hormone didn't seem to alter appetite or cause changes in the amount of food the mice ate.
"The animal burns off more calories, so over time loses weight, which was very fascinating because we knew that leptin caused weight loss by suppressing appetite and increasing metabolic rate," says researcher Rexford Ahima, MD, PhD, assistant professor of medicine at the University of Pennsylvania, in a news release. "Here we have another fat hormone that can cause weight loss but without affecting intake."
Researchers say fat hormones, such as leptin and adiponectin, are of interest because they may aid in promoting long-term weight loss. Over time, weight loss becomes more difficult because the body compensates, in part, by lowering its metabolic rate -- the rate at which it burns calories.
If drugs can be developed that capitalize on the metabolism-boosting properties of these fat hormones, they may be able to sustain weight loss efforts over a longer period of time without adverse health effects.
"Adiponectin or its targets in the brain and other organs could be harnessed to sustain weight loss by maintaining a high metabolic rate," ways Ahima. "This is only a possibility. We're not suggesting at this point that adiponectin will become a drug."