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 Organ-on-a-chip mimics heart's biomechanical properties
23.02.2017 | Vanderbilt University

nachricht Researchers identify cause of hereditary skeletal muscle disorder
22.02.2017 | Klinikum der Universität München

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: Breakthrough with a chain of gold atoms

In the field of nanoscience, an international team of physicists with participants from Konstanz has achieved a breakthrough in understanding heat transport

In the field of nanoscience, an international team of physicists with participants from Konstanz has achieved a breakthrough in understanding heat transport

Im Focus: DNA repair: a new letter in the cell alphabet

Results reveal how discoveries may be hidden in scientific “blind spots”

Cells need to repair damaged DNA in our genes to prevent the development of cancer and other diseases. Our cells therefore activate and send “repair-proteins”...

Im Focus: Dresdner scientists print tomorrow’s world

The Fraunhofer IWS Dresden and Technische Universität Dresden inaugurated their jointly operated Center for Additive Manufacturing Dresden (AMCD) with a festive ceremony on February 7, 2017. Scientists from various disciplines perform research on materials, additive manufacturing processes and innovative technologies, which build up components in a layer by layer process. This technology opens up new horizons for component design and combinations of functions. For example during fabrication, electrical conductors and sensors are already able to be additively manufactured into components. They provide information about stress conditions of a product during operation.

The 3D-printing technology, or additive manufacturing as it is often called, has long made the step out of scientific research laboratories into industrial...

Im Focus: Mimicking nature's cellular architectures via 3-D printing

Research offers new level of control over the structure of 3-D printed materials

Nature does amazing things with limited design materials. Grass, for example, can support its own weight, resist strong wind loads, and recover after being...

Im Focus: Three Magnetic States for Each Hole

Nanometer-scale magnetic perforated grids could create new possibilities for computing. Together with international colleagues, scientists from the Helmholtz Zentrum Dresden-Rossendorf (HZDR) have shown how a cobalt grid can be reliably programmed at room temperature. In addition they discovered that for every hole ("antidot") three magnetic states can be configured. The results have been published in the journal "Scientific Reports".

Physicist Dr. Rantej Bali from the HZDR, together with scientists from Singapore and Australia, designed a special grid structure in a thin layer of cobalt in...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

Booth and panel discussion – The Lindau Nobel Laureate Meetings at the AAAS 2017 Annual Meeting

13.02.2017 | Event News

Complex Loading versus Hidden Reserves

10.02.2017 | Event News

International Conference on Crystal Growth in Freiburg

09.02.2017 | Event News

 
Latest News

From rocks in Colorado, evidence of a 'chaotic solar system'

23.02.2017 | Physics and Astronomy

'Quartz' crystals at the Earth's core power its magnetic field

23.02.2017 | Earth Sciences

Antimicrobial substances identified in Komodo dragon blood

23.02.2017 | Life Sciences

VideoLinks
B2B-VideoLinks
More VideoLinks >>>