Insulin results are typically measured in microunits per milliliter (mcU/mL). Understanding your results requires considering the context and comparing them to normal ranges, which can vary slightly depending on the laboratory. A normal fasting insulin level is generally considered to be less than 17 mcU/mL. However, your doctor will interpret your results in conjunction with other factors, such as your symptoms, medical history, and other blood test results.
Factors Affecting Insulin Results
Several factors can influence insulin levels and the interpretation of your results:
- Fasting vs. Non-Fasting: A fasting insulin test requires a 12-hour fast beforehand [InsideTracker]. This eliminates fluctuations caused by food intake, providing a more reliable baseline. Non-fasting results can be less accurate.
- Medical Conditions: Certain health problems, such as those damaging red blood cells, can lead to falsely low results [Reference 1].
- Medication: High insulin levels may indicate you are using too much insulin medication [Reference 1].
- Hemolysis: Hemolysis, the breakdown of red blood cells, releases an insulin-degrading enzyme, potentially affecting results [Medscape].
Interpreting Your Results: High vs. Low
- High Insulin Levels: Elevated insulin levels can indicate insulin resistance, where your body's cells don't respond effectively to insulin, leading to higher blood sugar levels. This may be a precursor to type 2 diabetes [NIDDK]. High insulin can also result from excessive insulin medication.
- Low Insulin Levels: Low levels may indicate problems with insulin production, possibly suggesting conditions like type 1 diabetes, though further testing is required for diagnosis. Low results can also be falsely low due to medical conditions affecting red blood cells [Reference 1].
Additional Tests and Considerations
Often, insulin testing isn't done in isolation. Doctors may order a fasting insulin test along with other tests like:
- Glucose Tolerance Test: To assess how your body handles glucose.
- C-peptide test: To measure the amount of C-peptide, a byproduct of insulin production, helping differentiate between insulin production problems and insulin resistance [UCSF Health].
- A1C test: To measure average blood glucose levels over the past 2-3 months [ADA].
- Comprehensive Metabolic Panel (CMP): A broad panel of blood tests which might include glucose and other relevant markers.
Your doctor will interpret your results in the context of your overall health and other test results to provide an accurate diagnosis and treatment plan. Always discuss your results with your physician.
