What is this test?
Fasting insulin measures the level of the hormone insulin in the blood on an empty stomach. Together with fasting blood glucose, it is used to assess insulin resistance (HOMA-IR); it is frequently ordered when investigating difficulty losing weight, polycystic ovary syndrome and metabolic syndrome.
When is it requested?
Investigation of type I or II diabetes mellitus, hypoglycemia, insulinoma, and insulin resistance
What does a high fasting insulin result mean?
A high fasting insulin means your body is making extra insulin to keep blood sugar balanced and is most often linked to insulin resistance.
- Not fasting long enough before the test
- Excess weight, especially around the waist, and physical inactivity
- Insulin resistance, metabolic syndrome, fatty liver
- Polycystic ovary syndrome (PCOS)
- Pregnancy or certain medicines such as corticosteroids
- Using insulin injections
- Very rarely, an insulin-producing tumor (insulinoma)
What does a low fasting insulin result mean?
With normal blood sugar, a low fasting insulin usually reflects good insulin sensitivity; with high blood sugar, it may suggest reduced insulin production.
- Regular exercise and a healthy weight (good insulin sensitivity)
- Prolonged fasting
- Breakdown of red cells in the sample (hemolysis), a falsely low result
- Type 1 diabetes
- Advanced type 2 diabetes
- Pancreatic disease or surgery
My result is outside the reference range. What should I do?
Fast for 8–12 hours before the test. Fasting insulin is interpreted together with fasting glucose (HOMA-IR), not on its own; review the result with your doctor.
Reference ranges depend on the method, age and sex; always use the range printed on your report. This information is for general guidance only; consult your doctor for diagnosis and treatment.
Sample information
- Sample type: Serum
- Tube / container: Yellow-top tube
- Sample volume: 1 mL
Preparation
Fasting sample recommended.
Testing and results
- Method: ECLI
- Run schedule: Daily
- Turnaround time: 4 hours
Price and appointment
Add the test to your list to receive a price quote by e-mail, or call +90 850 640 07 30 / message us on WhatsApp (+90 537 301 22 14). You can have the test done at our branches or with our home blood collection service. Results can be viewed online with your Turkish ID number (or passport number for foreign nationals).