Burns change the behaviour of fat in the body

The behaviour of fat in the body fundamentally changes after a severe burn, according to a newly published study by Sunnybrook researchers.

“We found that severe burn injuries result in browning of the subcutaneous fat, which is the layer directly below the skin. This may explain why burn patients develop hypermetabolism, which negatively impacts their recovery,” says Dr. Marc Jeschke, Director, Ross Tilley Burn Centre at Sunnybrook.

Subcutaneous fat can behave in several different ways. In burn patients, ‘browning’ of fat describes the transition of fat from white to beige, sending the patient’s metabolic function into overdrive.

This state of hypermetabolism causes an increase in energy expenditure and insulin resistance in the patient, and the resulting complications can be fatal. In humans, the subcutaneous fat browning occurs 10 days after a burn injury.

Previous studies have shown that browning of fat has the effect of hypermetabolism in diabetic patients. During pre-clinical trials, Sunnybrook researchers found that severe burn injuries also produced a fat browning reaction.

They also found that browning was reduced by the beta-blocker propranolol, reducing the symptoms of hypermetabolism in burned patients.

The research team’s findings indicate that fat is much more important than anyone previously realized.

“The role of fat has been ignored in the past, but now we know it’s an active endocrine organ that has a huge effect on the outcomes of burn patients,” says Dr. Jeschke, who is also Professor, Department of Surgery, Department of Immunology, Division of Plastic & Reconstructive and General Surgery, University of Toronto.

The researchers hope the findings can be used in the future development of treatments to improve outcomes in burn patients.

The study, which was published today in Cell Reports, was supported by funding from CIHR, NIH and CFI Leader’s Opportunity Fund.