Formoterol, a new generation asthma medication, shows great promise for improving fat and protein metabolism, say Australian researchers, who have tested this effect in a small sample of men. The researchers present their results today at The Endocrine Society’s 93rd Annual Meeting in Boston.
The research team comprises members of Professor Ken Ho’s lab from Sydney’s Garvan Institute of Medical Research as well as Professor Ric Day, a clinical pharmacologist from St. Vincent’s Hospital.
Study leader, endocrinologist Dr Paul Lee, focused his PhD research on how various hormones affect metabolism. Of central importance is a class of hormones called catecholamines, which regulate heart rate, metabolism and breathing.
Formoterol is a synthetic catecholamine, the metabolic effects of which have not previously been studied in people. Therapy doses given to animals, however, have shown that it stimulates metabolism without affecting the heart.
“We have known for a long time that catecholamine influences the way the body handles nutrients, in particular fat and protein,” said Lee.
“The generation of drugs before formoterol was exploited in the livestock industry around 20 years ago – to reduce the fat and increase the protein content of meat. Unfortunately, these older drugs also caused a faster heart rate.”
“Formoterol is a new generation of this class of medication. It is highly selective for the kind of catecholamine receptors found in the lungs, and not those in the heart.”
“The new drug is also more selective for a similar receptor found in muscle and fat. In theory at least, it should have beneficial metabolic effects – like the older class of medication – without affecting the heart.”
Lee sourced the drug in its oral form, found the dose needed to give a metabolic effect, and gave it to 8 healthy men over a week.
“Energy metabolism increased by more than 10%, fat burning increased by more than 25%, while protein burning fell by 15%,” he said.
“So although whole body metabolism increased, these men burned fat while reducing the burning of protein. That’s a good thing because in the long run these effects may lead to a loss in fat mass and an increase in muscle.
“In this study, all 8 subjects tolerated the medication well – without any significant increase in heart rate.”
The next step will be to test the drug over a longer period in a larger sample of people to determine if the beneficial effects translate into improvement in body composition, health and function.
Energy expenditure and fat burning were calculated using ‘indirect calorimetry’ - a device that measures levels of oxygen inhaled and carbon dioxide exhaled.
Protein metabolism was measured using the state-of-the art method known as 'leucine turnover technique'. The amino acid leucine was infused and its fate tracked throughout the body to estimate rate of protein synthesis and breakdown.
The Garvan Institute of Medical Research was founded in 1963. Initially a research department of St Vincent's Hospital in Sydney, it is now one of Australia's largest medical research institutions with over 500 scientists, students and support staff. Garvan's main research programs are: Cancer, Diabetes & Obesity, Immunology and Inflammation and Neuroscience. Garvan's mission is to make significant contributions to medical science that will change the directions of science and medicine and have major impacts on human health. The outcome of Garvan's discoveries is the development of better methods of diagnosis, treatment, and ultimately, prevention of disease.