Insulin resistance is one of the key factors in the development of type 2 diabetes.  Thus, it is very important to measure the level of insulin resistance.

Insulin testing has several other possible uses. Insulin testing may be used to help:

  • Diagnose an insulinoma (insulin production from a tumor), verify tumor removal has been successful, and/or to monitor for recurrence.
  • Diagnose the cause of hypoglycemia (low blood sugar) in an individual with signs and symptoms
  • Identify insulin resistance
  • Monitor the amount of insulin produced by the beta cells in the pancreas (endogenous); in this case, a C-peptide test may also be done. Insulin and C-peptide are produced by the body at the same rate as part of the conversion of proinsulin to insulin in the pancreas. Both tests may be ordered when a health practitioner wants to evaluate how much insulin in the blood is made by the body and how much is from outside (exogenous) sources such as insulin injections. The test for insulin measures insulin from both sources while the C-peptide test reflects insulin produced by the pancreas.
  • Determine when a type 2 diabetic might need to start taking insulin to supplement oral medications.
  • Determine and monitor the success of an islet cell transplant intended to restore the ability to make insulin, by measuring the insulin-producing capacity of the transplant.