Appetite hormone doesn't work in obese people

A hormone that involves regulation of appetite, loses its ability to help obese people feel full after a meal, but continues to suppress hunger in people suffering from type 1 diabetes, according to a study.

The primary role of glucagon, a hormone secreted by the pancreas, is to signal the body to release stored glucose when blood sugar falls too low. But growing evidence suggests the hormone also may play a role in controlling food intake and feelings of fullness, or satiation, through signaling the body to reduce levels of other appetite hormones like ghrelin.

Lead author Ayman M. Arafat, MD, of Charite-University Medicine in Berlin, Germany, said that once a person becomes obese, glucagon no longer induces feelings of fullness.

The prospective, double-blinded, placebo-controlled study investigated glucagon levels and appetite among 11 obese people, 13 people with type 1 diabetes and 13 lean people.

Participants received injections of either glucagon or a placebo. Researchers then measured participants' appetites using a satiety scale as well as levels of the appetite hormone ghrelin.

Feelings of fullness did not differ between obese study participants who received glucagon injections and those who were given the placebo. In comparison, participants who were lean or had type 1 diabetes reported feeling significantly more full after receiving glucagon. The response to the hormone was detectable in this population, even 24 hours after it was administered.

The study has been accepted for publication in The Endocrine Society's Journal of Clinical Endocrinology and Metabolism (JCEM).