Belly fat linked to inflammation

ANN ARBOR, Mich., Jan. 23 (UPI) -- U.S. scientists say the link between so-called belly fat and arteriosclerosis may be inflammation.

The study, published online in advance of print in the journal Circulation, also found a drug already used to treat diabetics -- pioglitazone -- may help calm this inflammation.

The discovery came partly by chance. Originally, the researchers were transplanting fat to help produce the hormone leptin generated by fat cells in mice genetically lacking the hormone.

"In addition to producing leptin and preventing obesity, the fat transplants became inflamed, attracting immune cells called macrophages," study team leader Dr. Daniel Eitzman of University of Michigan Medical School, in Ann Arbor, said in a statement. "Since the mice were genetically identical except for leptin, this shouldn't have happened. But the inflammation was there, and it was chronic."

Since the fat was transplanted, the inflammation could be attributed directly to the fat itself and to obesity. The researchers also found differences between the belly fat -- visceral fat -- compared to the type of fat found under the skin.

"There appeared to be an interaction between the macrophages causing the inflammation in the visceral fat and the process of atherosclerosis," Eitzman said.