Insulin levels are often ordered in conjunction with a fasting blood glucose test, and can be used to diagnose insulin resistance, Type 2 Diabetes, hypoglycaemia and other illnesses. 


Insulin levels must be evaluated in context. If fasting insulin and glucose levels are normal, most likely the body's glucose regulation system is functioning normally.  If insulin is raised and glucose is normal and/or moderately raised, then there may be some insulin resistance.  If the insulin is low and the glucose is high, then most likely there is insufficient insulin being produced by the pancreas. If insulin levels are normal or raised and glucose levels are low, then the patient is hypoglycaemic due to excess insulin.


Insulin resistance leads to many chronic diseases and to Type 2 Diabetes.  As Australia has particularly high levels of obesity, it is therefore very important to know your risk for insulin resistance, particularly if you weigh more than your healthy weight range or if you have adult onset diabetes in your family history.


Raised insulin levels is also seen in: Acromegaly, Cushing’s Syndrome, Fructose or Galactose intolerance, Insulinomas, and as a result of taking certain drugs (such as corticosteroids, levodopa and oral contraceptives). 


Decreased insulin levels is generally evident in diabetes and hypopituitarism.