Self-administered subcutaneous injections of a substance called oxyntomodulin lead to weight loss and an apparent reduction in fat deposits, UK researchers report.

“Oxyntomodulin is a natural hormone,” said senior investigator Dr. Stephen R. Bloom, “which is released every day after a normal meal and acts to make you feel less hungry. This study showed administering it before a meal decreased food intake and produced a very significant weight loss, greater than other marketed or near-to-market agents, over the 4 weeks studied.”

Bloom, of Hammersmith Hospital in London, and colleagues note in the journal Diabetes that oxyntomodulin is one of several gut hormones that have been found to modulate appetite. It has been shown to reduce food intake in both animals and humans.

To investigate further, the researchers conducted a study involving 26 overweight or obese volunteers who were randomly assigned to inject oxyntomodulin or inactive saline subcutaneously three times a day, 30 minutes before each meal for 4 weeks.

They were also asked to maintain their normal diet and regular level of physical exercise over the course of the study.

Body weight decreased by an average of 2.3 kilos (5 pounds) in the active treatment group versus 0.5 kg (1 pound) in the saline group. The oxyntomodulin group showed changes in levels of the fat-related hormones leptin and adiponectin that indicated a loss of fat.

The people in the oxyntomodulin group also ate less, although there was no change in perceived food palatability.

Mimicking the post-meal feeling of satiety by administering a natural hormone such as oxyntomodulin, the researchers conclude, “may provide a more specific treatment for Obesity” than other approaches.

Moreover, added Bloom, “Oxyntomodulin works by a different mechanism from existing marketed, and near-market, weight-control medications, none of which are particularly effective. An additional agent is very necessary if we are to treat effectively the ever-increasing problem of Obesity.”

SOURCE: Diabetes, August 2005.