A Closer Look at Insulin Resistance
Insulin resistance occurs when muscle, fat and other tissues do not respond well to insulin’s signals to move sugars into the cells. It occurs as a result of chronic inflammation from any cause. This resistance will trigger the pancreas (beta cells) to compensate by producing more of the hormone. However, if resistance increases, blood glucose levels will rise. In an attempt to reduce these levels, the body will call on the kidneys to flush out the excess. This call on body fluids will then trigger thirst.
Diabetes and obesity are twin epidemics. The CDC also estimates that one in every 3 US adults is insulin resistant or pre-diabetic, a condition that can lead to Type II diabetes. Persistent organic pollutants and other synthetic chemicals, which can act as endocrine disruptors, have also been linked to insulin resistance.
Research at John Hopkins Medical School has elucidated the development of insulin resistance. According to Dr. Gerald Hart in a Science Daily interview, “Cells don’t respond to insulin itself. Instead, a whole cascade of events, set in motion by insulin, eventually causes cells to take in sugar.”
As long ago as 2002, research at the school identified a specific trigger of insulin resistance: glycosylation, the attachment of a sugar to a protein. Proteins “involved in passing along insulin’s message were unlikely to work properly when coated in extra sugar.” Dr. Hart explains that glycosylation happens to proteins on the cell surface as well as inside cells:
Complex sugars are added only to proteins outside the cell, but simple sugars are used all the time in the nucleus and cytoplasm to modify proteins. It's this glycosylation that happens inside the cell, involving simple sugars, that is the key in insulin resistance.
The research pointed also to the simple sugar derived from glucose called “O-linked beta-N-acetylglucosamine” (O-GlcNAcylation) bound to proteins inside the cells that “caused the cells to stop responding to insulin.”
Dr. Hart discusses why high glucose in the blood is toxic in this short video: