What is insulin resistance?
Insulin is a hormone produced by the beta cells of the pancreas. These cells are scattered throughout the pancreas in small clusters known as the islets of Langerhans. The insulin produced is released into the blood stream and travels throughout the body. Insulin is an essential hormone that has many actions within the body. Most actions of insulin are directed at metabolism (control) of carbohydrates (sugars and starches), lipids (fats), and proteins. Insulin also regulates the functions of the body's cells, including their growth. Insulin is critical for the body's use of glucose as energy.
Insulin resistance (IR) is a condition in which the body's cells become resistant to the effects of insulin. That is, the normal response to a given amount of insulin is reduced. As a result, higher levels of insulin are needed in order for insulin to have its proper effects, and the pancreas compensates by trying to produce more insulin. This resistance occurs in response to the body's own insulin (endogenous) or when insulin is administered by injection (exogenous).
With insulin resistance, the pancreas produces more and more insulin until the pancreas can no longer produce sufficient insulin for the body's demands, and then blood sugar rises. Insulin resistance is a risk factor for development of diabetes and heart disease.