Recent research suggests that insulin resistance and inflammation are linked through the actions of some inflammatory immune cells and the genes which govern them.
For some time scientists have known that there is a somewhat hyperactive immune response in people with type II diabetes mellitus, resulting in an overproduction of inflammatory immune chemicals with nothing constructive to do in the body. Substances with mellifluous names such as TNF-alpha, pro-inflammatory cytokines and FOXO-1 became the focus of research into the causes of insulin resistance with some very interesting results.
Substances secreted by the immune cells are generally referred to as cytokines. One of these cytokines in particular – TNF-alpha – plays a major role in inflammation and the development of disease. Researchers at Harvard University in the early 1990′s found that rats with type II diabetes had high levels of TNF-alpha in their fatty tissues. To learn more about the role TNF-alpha might play in diabetes, they then bred rats with obese rats which were unable to produce TNF-alpha and found that these rats did not develop diabetes. Since then research has progressed in this area and scientists have discovered that not only TNF-alpha, but inflammation in general can activate and increase the expression of several proteins that suppress the insulin-signalling pathways, resulting in insulin resistance.
Obesity and insulin resistance are both drivers of inflammation causing a vicious cycle through a positive feedback loop. When fat cells have grown to such an extent that the area they occupy is too overcrowded and cramped, circulation is decreased, they are unable to be properly supplied with nutrients and oxygen from the blood supply and those fat cells start to die, which attracts immune cells to the area. When someone becomes severely insulin resistant and the pancreas can no longer keep up with the demand for insulin, the activity of a protein called FOXO-1 is increased. Ordinarily, insulin rapidly inhibits FOXO-1 by moving it out of the nucleus of cells where it can begin to degrade. FOXO-1 turns on the expression of another major inflammatory cytokine – interleukin 1-beta – which interferes in the insulin signalling pathway.
It is not yet known whether inflammation precedes insulin resistance or vice versa or whether both pathways are possible. In the interim, it would seem sensible for those with insulin sensitivity issues, to do everything they can to lower their inflammation levels. Blood tests such as C-reactive Protein (CRP) and Erythrocyte Sedimentation Rate (ESR) can help monitor progress in this area. Stress-reduction through such activities as meditation, physical exertion, listening to music or simply having some “me” time are vital. Fresh fruit and vegetables, omega 3 fatty acids and ginger are also potent anti-inflammatory agents.
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