A new treatment combining two hormones can reduce appetite, according to new research at Imperial College London.

The study presented today at the Society for Endocrinology annual conference in Harrogate provides ‘first in man’ evidence that a combined therapy using the hormones glucagon and glucagon-like peptide 1 (GLP-1) may form the basis for a new treatment for obesity and diabetes in the future.

Previous results from animal studies showed that the combination might be an effective lead to combat obesity and diabetes. The two hormones play key roles in regulating blood sugar. Glucagon works in opposition to insulin, preventing the storage of glucose in fat deposits and the liver, and raising blood sugar levels. GLP-1 stimulates the release of insulin to lower blood sugar and also acts on the brain to reduce appetite.

The research team, led by Professor Stephen Bloom from the Department of Medicine at Imperial, set out to identify whether glucagon and GLP-1 infused into the blood might work together to reduce appetite. In this small study, 16 volunteers were given a sequence of four treatments: glucagon, GLP-1, glucagon and GLP-1 in combination, and saline as a control. The order of the treatments was determined at random, with neither the subject nor the experimenter aware of what was being given on each occasion.

Each treatment was given via a drip over a period of two hours. After the first hour and half, each volunteer was offered a meal. Researchers recorded how much they ate and measured their energy expenditure and blood sugar levels. 

The subjects ate 13 per cent fewer calories after being given the two hormones in combination compared with saline, but there was no significant difference after taking either hormone on its own.

“The hormones glucagon and GLP-1 are both used by the body to control blood sugar and metabolism, so there is great interest in utilising them to find new treatments for obesity and type 2 diabetes,” said Professor Bloom.

“We found that volunteers treated with a glucagon/GLP-1 combination consumed significantly less food. These data replicate our findings in animals, suggesting that a glucagon/GLP-1 combination may be a promising lead from which to develop a new treatment for obesity and diabetes.

“Thirteen per cent is a big reduction in food intake by anyone's standards, but our experiment is only an appetiser. An effective future treatment will need to suppress appetite in the long term, so we next aim to establish whether the effects can be sustained to lead to real weight loss.”

Based on a news release from the Society of Endocrinology.