OVERVIEW
WHAT IS INSULIN FASTING?
Insulin is a hormone that helps transport glucose from the blood to within the cells. Therefore, plays an important role in regulating blood glucose levels. The test measures the level of insulin in blood after the fasting period.
WHY IS INSULIN FASTING PERFORMED?
Insulin fasting test is performed for the following reasons:
- To help evaluate insulin production.
- To help diagnose the presence of an insulin-producing tumor in the islet cells of the pancreas.
- To help determine the cause of low blood glucose (hypoglycemia)
- To help determine when a type 2 diabetic might need to start taking insulin to supplement oral medications.
FREQUENTLY ASKED QUESTIONS (FAQS):
How is this test performed?
This test is performed on a blood sample. The blood is obtained from the vein and this is performed by a healthcare provider in the following way.
- clean the skin
- put an elastic band above the area
- insert a needle into a vein (usually in the arm inside of the elbow or on the back of the hand)
- pull the blood sample into a vial or syringe
- take off the elastic band and remove the needle from the vein
What are the risks associated with this test?
There is no significant risk associated with this test. A small bruise or mild soreness around the blood test site is common and can last for a few days. Get medical care if the discomfort gets worse or lasts longer.
How does Insulin affect PCOS?
High insulin levels can cause thickening and darkening of the skin on the back of the neck, axilla (under the arms), and groin area. In young women with PCOS, high insulin levels can cause the ovaries to make more androgen hormones such as testosterone. This can cause increased body hair, acne, and irregular or few periods.
Is everyone with PCOS Insulin Resistant?
Insulin resistance does not affect everyone in the same way, some women with Insulin resistance develop PCOs while others do not.
What is Hyperglycemia?
Hyperglycemia is caused by abnormally high blood glucose levels. It can be caused by overproduction of hormone Glucagon. Certain medications like corticosteroids and oral contraceptives can cause increase in glucose levels.
What is Hypoglycemia?
Hypoglycemia is caused by low blood sugar levels, low secretion of pituitary hormones or pancreatic diseases.
INTERPRETATION OF THE TEST RESULTS:
A high level of fasting insulin indicates Insulin resistance. Fasting insulin test is usually ordered with Fasting glucose test and the results interpreted as follows:
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Fasting insulin level
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Fasting glucose level
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Disorder
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Normal
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Normal
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None
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High
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Normal or slightly high
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Insulin Resistance
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Low
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High
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Insufficient insulin production, e.g., diabetes
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Normal or high
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Low
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Hypoglycemia due to over secretion of insulin
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Normal range of Glucose Fasting is : 2-25 uU/ml
WHAT DOES THE TEST MEASURE?
Insulin is the primary hormone that responds to what we eat. Insulin is released from the pancreatic beta cells when carbohydrates are ingested, and, to a lesser degree, protein. Insulin is responsible for the uptake of glucose by the cells from blood for utilization and storage. It helps to maintain blood glucose levels within a normal range and plays an essential role in the metabolism of lipids.
Blood Glucose and Insulin work in correlation and balance each other. A rise in blood sugar stimulates insulin production by the pancreas, causes insulin levels to rise in blood. Insulin stimulates the uptake of glucose by cells, leading to a fall in blood glucose. Low insulin production by pancreas or inability of cells to respond to insulin cause a rise in blood sugar levels, also known as Hyperglycemia.
