Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

The ICEMAN study -- How keeping cool could spur metabolic benefits

23.06.2014

A new study being presented today at ICE/ENDO 2014, the joint meeting of the International Society of Endocrinology and the Endocrine Society in Chicago, demonstrates that ambient temperatures can influence the growth or loss of brown fat in people. Cool environments stimulate growth, warm environments loss.

Brown fat, also known as brown adipose tissue, is a special kind of fat that burns energy to generate heat. It keeps small animals and babies warm, and animals with abundant brown fat are protected from diabetes and obesity. How brown fat is regulated in people, and how it relates to metabolism, have been unclear.

Endocrinologist Dr Paul Lee from Sydney's Garvan Institute of Medical Research, recently undertook The Impact of Chronic Cold Exposure in Humans (ICEMAN) study at the National Institutes of Health (NIH) in Washington*, funded as an NHMRC Early Career Research Fellow.

The study results, which clearly show the 'plasticity' of brown fat in humans, are published online today in the journal Diabetes to coincide with the ICE/ENDO meeting.

Lee's previous studies have shown that people with plentiful brown fat stores tend to be lean and have low blood sugar levels. His studies have also shown – in the laboratory – that ordinary human white fat cells can change into brown fat cells.

For the ICEMAN study, 5 healthy men were recruited and exposed to four month-long periods of defined temperature – well within the range found in climate-controlled buildings – at the NIH Clinical Centre. They lived their normal lives during the day, and returned each night to the centre, staying for at least 10 hours in a temperature-regulated room.

For the first month, the NIH rooms were maintained at 24º C, a 'thermo-neutral' temperature at which the body does not have to work to produce or lose heat.

The temperature was then moved down to 19º C for the second month, back to 24º for the third month, and up to 27º for the fourth month.

At the end of each month, participants underwent a detailed 'thermal metabolic evaluation' in a whole room calorimeter. Measurements taken at the end of the first month represented 'baseline'.

In addition, cold-stimulated PET/CT scans measured brown fat, and muscle and fat biopsies revealed tissue metabolic changes.

Independent of the season during which the study was carried out, brown fat increased during the cool month and fell during the warm month.

Among the metabolic benefits of increased brown fat was heightened insulin sensitivity. This suggests that people with more brown fat require less insulin after a meal to bring their blood sugar levels down.

"The big unknown until this study was whether or not we could actually manipulate brown fat to grow and shrink in a human being," said Dr Lee.

"What we found was that the cold month increased brown fat by around 30-40%."

"During the second thermo-neutral month at 24 degrees, the brown fat dropped back, returning to baseline."

"When we put the temperature up to 27 degrees during the fourth month, the volume of brown fat fell to below that of baseline."

Dr Lee sees promise in brown fat for people with diabetes, whose bodies have to work hard to bring sugar levels down after a meal.

"The improvement in insulin sensitivity accompanying brown fat gain may open new avenues in the treatment of impaired glucose metabolism in the future. On the other hand, the reduction in mild cold exposure from widespread central heating in contemporary society may impair brown fat function and may be a hidden contributor to obesity and metabolic disorders," Lee said.

"Studies have been performed in the UK and US measuring bedroom, dining room and lounge room temperatures in people's homes over the last few decades, and the temperature has climbed from about 19 to 22, a range sufficient to quieten down brown fat."

"So in addition to unhealthy diet and physical inactivity, it is tempting to speculate that the subtle shift in temperature exposure could be a contributing factor to the rise in obesity."

###

*The study was conducted at and supported by the Intramural Research Program of the National Institute of Diabetes and Digestive and Kidney Diseases at the NIH. The content of this news release is the sole responsibility of the authors and does not necessarily represent the official views of NIH.

Dr Lee's role in the study was also supported by the Royal Australasian College of Physicians Foundation and the School of Medicine at The University of Queensland.

Alison Heather | Eurek Alert!

Further reports about: Diabetes NIH brown adipose tissue brown fat heat metabolic metabolism sugar temperature

More articles from Health and Medicine:

nachricht Newly discovered 'multicomponent' virus can infect animals
26.08.2016 | US Army Medical Research Institute of Infectious Diseases

nachricht Symmetry crucial for building key biomaterial collagen in the lab
26.08.2016 | University of Wisconsin-Madison

All articles from Health and Medicine >>>

The most recent press releases about innovation >>>

Die letzten 5 Focus-News des innovations-reports im Überblick:

Im Focus: Virtual Reality: 3D Human Body Reconstruction from Fraunhofer HHI digitizes Human Beings

Scientists at the Fraunhofer Institute for Telecommunications, Heinrich Hertz Institute, HHI have developed a method by which the realistic image of a person can be transmitted into a virtual world. The 3D Human Body Reconstruction Technology captures real persons with multiple cameras at the same time and creates naturally moving dynamic 3D models. At this year’s trade fairs IFA in Berlin (Hall 11.1, Booth 3) and IBC in Amsterdam (Hall 8, Booth B80) Fraunhofer HHI will show this new technology.

Fraunhofer HHI researchers have developed a camera system that films people with a perfect three-dimensional impression. The core of this system is a stereo...

Im Focus: Streamlining accelerated computing for industry

PyFR code combines high accuracy with flexibility to resolve unsteady turbulence problems

Scientists and engineers striving to create the next machine-age marvel--whether it be a more aerodynamic rocket, a faster race car, or a higher-efficiency jet...

Im Focus: X-ray optics on a chip

Waveguides are widely used for filtering, confining, guiding, coupling or splitting beams of visible light. However, creating waveguides that could do the same for X-rays has posed tremendous challenges in fabrication, so they are still only in an early stage of development.

In the latest issue of Acta Crystallographica Section A: Foundations and Advances , Sarah Hoffmann-Urlaub and Tim Salditt report the fabrication and testing of...

Im Focus: Piggyback battery for microchips: TU Graz researchers develop new battery concept

Electrochemists at TU Graz have managed to use monocrystalline semiconductor silicon as an active storage electrode in lithium batteries. This enables an integrated power supply to be made for microchips with a rechargeable battery.

Small electrical gadgets, such as mobile phones, tablets or notebooks, are indispensable accompaniments of everyday life. Integrated circuits in the interiors...

Im Focus: UCI physicists confirm possible discovery of fifth force of nature

Light particle could be key to understanding dark matter in universe

Recent findings indicating the possible discovery of a previously unknown subatomic particle may be evidence of a fifth fundamental force of nature, according...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

The energy transition is not possible without Geotechnics

25.08.2016 | Event News

New Ideas for the Shipping Industry

24.08.2016 | Event News

A week of excellence: 22 of the world’s best computer scientists and mathematicians in Heidelberg

12.08.2016 | Event News

 
Latest News

Cancer: Molecularly shutting down cancer cachexia

31.08.2016 | Life Sciences

Robust fuel cell heating unit developed

31.08.2016 | Power and Electrical Engineering

Algorithms Offer Insight into Cellular Development

31.08.2016 | Life Sciences

VideoLinks
B2B-VideoLinks
More VideoLinks >>>