Why insulin tests are not recommended routinely for diagnosis and management of diabetes?
Insulin tests are normally done to help diagnose insulinomas and to help to assess the presence of documented acute or chronic hypoglycemia, check for insulin resistance and to help determine when a type 2 diabetic might need to start taking insulin injections to supplement oral medications.
In other words, this test is not meant to diagnose diabetes as a routine or to monitor the benefits of treatment. Routine tests to diagnose diabetes are based on presence or absence of glucose in the blood beyond the normal range. An increase or decrease in the levels not only confirms the diagnosis of diabetes but also in monitoring the usefulness and response of a drug chosen in the treatment of diabetes.
Insulin tests to determine the levels of insulin are usually ordered following an abnormal glucose test or when a patient has sudden or chronic fall in the glucose characterized by sweating, palpitations, hunger, confusion, visual problems and convulsions.
When once insulin test is done the results achieved can be interpreted as follows:
- If fasting insulin and glucose levels are normal it means that the body’s glucose regulation system is functioning normally.
- If Insulin is elevated and glucose is normal and/or moderately elevated it might mean that there is insulin resistance at the level of the cellular metabolism.
- If the insulin is low and glucose is high it is most likely that the production of insulin is insufficient.
- If insulin levels are normal or elevated and the glucose level is low it could be a sure sign of hypoglycemia due to excess insulin
This explains the reason why insulin tests are not done as a routine to detect diabetes or monitor management of diabetes but reserved only as a special test for special circumstances.