According to a team of scientists at the Walter and Eliza Hall Institute, the link between obesity and diabetes may be explained by the inflammation-causing cells in fat tissue.
The new breakthrough find by Professor Len Harrison and Dr John Wentworth from the Autoimmunity and Transplantation division of the institute is opening an option for the development of new anti-inflammatory treatments to prevent insulin resistance and other health conditions associated with obesity.
From the study, insulin resistance in human obesity is much related to the presence of inflammatory cells in fat tissue, specifically the group of macrophage cells, said Prof Harrison.
During an immune respond to infections, white blood cells from the bone marrow and macrophages come to play their role in providing immunity.
However, in obese people, macrophages go into fat tissue where they trigger inflammation and release cytokines - which are chemical messenger molecules, used the communication between immune cells.
Insulin resistance - that eventually leads to diabetes and heart disease- has been found to be caused by certain cytokines.
Working with Mr Gaetano Naselli, Ms Belinda Phipson and Dr Gordon Smyth at the institute along with Professor Paul O'Brien at Monash University's Centre for Obesity Research and Education, Prof Harrison and Dr Wentworth worked on analyzing the fat tissue of more than 100 Victorians who had went through lapband surgery.
The first proof in humans - based on their findings- showed that macrophages in the fat tissues are responsible in releasing cytokines that affect cells from responding appropriately to insulin presence.
According to Prof Harrison, the inflammation that occurs in the fat tissue is the cause of complications in obese people such as insulin resistance, diabetes, cardiovascular disease from hardening of the arteries and liver pathology.
He said, These complications could be prevented by developing drugs that target certain cytokines released by the macrophages.
The study also revealed that weight loss in obese people causes macrophages in the fat to disappear as well as the risk of developing insulin resistance and diabetes.