06.07.2016 - By Dr Jyotsna Verma
Insulin resistance (IR) is a pathological condition in which cells fail to respond normally to the hormone insulin. To prevent hyperglycemia and noticeable organ damage over time, the body produces insulin when glucose starts to be released into the bloodstream from the digestion of carbohydrates (primarily) in the diet. Under normal conditions of insulin reactivity, this insulin response triggers glucose being taken into body cells, to be used for energy, and inhibits the body from using fat for energy, thereby causing the concentration of glucose in the blood to decrease as a result, staying within the normal range even when a large amount of carbohydrates is consumed. A habitually high intake of carbohydrates, simple sugars, and particularly fructose, e.g. with sweetened beverages, contributes to insulin resistance and has been linked to weight gain and obesity. If high and excess blood sugar from the digestion of primarily carbohydrates in the diet is not sufficiently absorbed by cells even in the presence of insulin, the increase in the level of blood sugar can result in the classic hyperglycemic triad of polyphagia (increased appetite), polydipsia (increased thirst), and polyuria (increased urination). Avoiding carbohydrates and sugars, a no-carbohydrate diet or fasting can reverse insulin resistance.
When the body produces insulin under conditions of insulin resistance, the cells are resistant to the insulin and are unable to use it as effectively, leading to high blood sugar. Beta cells in the pancreas subsequently increase their production of insulin, further contributing to a high blood insulin level. This often remains undetected and can contribute to the development of type 2 diabetes, obesity or latent autoimmune diabetes of adults. Although this type of chronic insulin resistance is harmful, during acute illness it is actually a well-evolved protective mechanism. Recent investigations have revealed that insulin resistance helps to conserve the brain's glucose supply by preventing muscles from taking up excessive glucose. In theory, insulin resistance should even be strengthened under harsh metabolic conditions such as pregnancy, during which the expanding fetal brain demands more glucose. People who develop type 2 diabetes usually pass through earlier stages of insulin resistance and prediabetes, although those often go undiagnosed. Insulin resistance is a syndrome (a set of signs and symptoms) resulting from reduced insulin activity; it is also part of a larger constellation of symptoms called the metabolic syndrome. Insulin resistance may also develop in patients who have recently experienced abdominal or bariatric procedures. This acute form of insulin resistance that may result post-operatively tends to increase over the short term, with sensitivity to insulin typically returning to patients after about five days.
This Article was originally published on 06.07.2016 and updated most recently on 30.09.2025