Insulin stimulates glucose uptake into tissues, and its ability to do so varies greatly among individual persons. In insulin resistance, tissues have a diminished ability to respond to the action of insulin. To compensate for resistance, the pancreas secretes more insulin.The liver also becomes insulin resistant and responds by overproducing glucose. Insulin-resistant persons, therefore, have high plasma insulin levels and can develop hyperglycemia as the pancreas is unable to keep up.
Insulin resistance can be defined as a cluster of abnormalities, including obesity, hypertension, dyslipidemia and type 2 diabetes, that are associated with insulin resistance, compensatory hyperinsulinemia and subsequent hyperglycemia.
The current treatments for insulin resistance involve caloric and carb restiction, exercise, and treatment of the abnormalities associated with it. If those fail, then the treatment progresses to medications to increase insulin sensitivity.
Exogenous insulin cannot increase the insulin sensitivity of cells.