The pancreas are responsible for the production of insulin in the body, which transports glucose to the cells, thus providing them with their main source of energy. Production of insulin should be in the normal range in order to remain healthy – too little insulin in the body can make an individual weak as the body cells are starved and too high levels of insulin in the body, as seen in insulinoma, can lead to hypoglycemia – a condition in which low blood glucose levels are detected. The insulin test measures the levels of insulin in the blood.
Why is the test ordered?
An insulin test may be useful in identifying the presence of insulin resistance in the body and determining the cause of hypoglycaemia. The test is helpful in diagnosing insulinoma and checking insulin levels in order to determine the amount of insulin produced by beta cells. The test may also be useful for the management of diabetes mellitus.
When is the test recommended?
The test may be ordered by a physician when he or she notices hypoglycaemia owing to the presence of the following symptoms in a patient:
- Blurred vision
- Hunger, etc.
An insulin test may also be recommended when an individual is suspected to suffer from insulin resistance due to-
- Heart disease
- Metabolic syndrome
- Prediabetes or
The test may also be used as a post-surgical test along with a c-peptide test following the removal of insulinoma to ensure that the condition has been successfully removed.
How is the sample collected?
A blood sample is collected from a vein in the arm.
How to prepare for the test?
The patient advised not to eat and drink anything for up to eight hours or longer leading up to the test. But occasionally, fasting may not be possible if the glucose tolerance test is performed along with the insulin test, in which case it may be avoided.