Insulin

Casandra

Casandra Test Code LC59859Version 1 (DRAFT)

Performing Lab

Lab LabcorpLab Test ID 004333CPT Code 83525

Also known as: Immunoreactive Insulin

Clinical Use

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Use

Insulin is a peptide hormone that plays a critical role in regulating blood sugar levels. Serum insulin determinations are essential for patients with hypoglycemia symptoms, where an insulinoma is suspected. Insulin measurement is pivotal in diagnosing insulinoma by identifying elevated insulin levels during hypoglycemic episodes. Insulin levels are also useful for assessing insulin secretion capacity and evaluating insulin sensitivity. While fasting insulin is commonly measured to assess insulin resistance, the measurement isn't included in the American Diabetes Association's recommendations for diagnosing diabetes.

Special Instructions

This test may experience interference if the sample is collected from a patient consuming high doses of biotin supplements. Patients should be advised to stop taking biotin at least 72 hours before collection. Use a red-top tube or gel-barrier tube and transfer serum to a plastic transport tube if a red-top tube is used. Avoid hemolysis when collecting the sample.

Limitations

Test 004333, Insulin, is highly specific for human insulin and does not react with certain insulin analogs like insulin aspart, glargine, lispro, glulisine, or detemir. However, circulating antibodies to insulin and therapeutic insulin can interfere with immunoassay results. Monoclonal mouse antibodies used in the test may also cause interference. In rare cases, high titers of antibodies to streptavidin and ruthenium can interfere with the test despite having additives to minimize these effects.

Test Details