Japanese scientists say they have found a link between a substance excreted by fat cells, called monocyte chemoattractant protein-1 (MCP-1), and insulin resistance. The new findings were published on May 11 by the Journal of Clinical Investigation (Kanda J et al. J Clin Invest. 2006. doi:10.1172 /JCI26498).
The researchers found that mice genetically engineered to produce very high levels of MCP-1 in fat tissue, as well as control mice made obese through a high-fat diet, developed insulin resistance, increased infiltration of macrophages into fatty tissue, and accumulation of fat in the liver. They also found that these effects were considerably reduced in mice engineered to not produce any MCP-1 at all. Introducing an MCP-1–blocking mutation in diabetes-prone mice and in control mice fed a high-fat diet also lessened insulin resistance in the animals.
Stephenson J. Fat Cells and Insulin Resistance. JAMA. 2006;295(23):2711. doi:10.1001/jama.295.23.2711-d