Inflammation-causing cells in fat tissue may explain the link between obesity and diabetes, Australian researchers have shown. And the discovery paves the way for new anti-inflammatory treatments that prevent insulin resistance and other obesity-related complications.
Scientists at the Walter and Eliza Hall Institute of Medical Research and the Royal Melbourne Hospital examined fat tissue from more than 100 lean and obese patients. And their research demonstrated that "insulin resistance in human obesity is closely related to the presence of inflammatory cells in fat tissue, in particular a population of macrophage cells," according to Professor Len Harrison.
Macrophages--white blood cells derived from the bone marrow--are immune cells that normally respond to infections. In obese people, macrophages move into the fat tissue where they cause inflammation and release cytokines, which are chemical messenger molecules used by immune cells to communicate. Certain cytokines cause cells to become resistant to the effects of the hormone insulin, leading to diabetes and heart disease.
Their findings, published in the journal Diabetes, provide the first evidence in humans that macrophages in the fat tissue are producing cytokines that prevent cells from appropriately responding to the presence of insulin.
More than 50 percent of Australian adults are overweight, and there are an estimated 1.2 million people in Australia who suffer from Type 2 diabetes, the Australian Broadcasting Corporation reports.