Insulin, Intact, LC/MS/MS

Test Code
93103


CPT Codes
83525

Preferred Specimen
0.5 mL serum


Patient Preparation
Overnight fasting is required.

Minimum Volume
0.3 mL


Instructions
Collect blood samples observing routine precautions for venipuncture.
Allow serum samples to clot completely before centrifugation.


Transport Temperature
Refrigerated (cold packs)


Specimen Stability
Room temperature: 24 hours
Refrigerated: 28 days
Frozen: 28 days


Reject Criteria (Eg, hemolysis? Lipemia? Thaw/Other?)
Hemolysis


Methodology
Immunocapture Liquid Chromatography/Tandem Mass Spectrometry

Setup Schedule
Set up: Mon-Sat; Report available: 4-6 days


Reference Range
≤16 uIU/mL


Clinical Significance
Insulin is a key hormone involved in the control of blood glucose and regulation of fatty acid metabolism. Insulin measurement is primarily used to evaluate the cause of hypoglycemia. Inappropriately elevated insulin in blood (hyperinsulinemia) is associated with hypoglycemia(1) or in disorders linked to hyperglycemia, such as metabolic syndrome(2). Causes of hyperinsulinemia include insulinoma, insulin resistance, noninsulinoma pancreatogenous hypoglycemia syndrome, insulin antibodies, surreptitious insulin administration or other drug-induced hyperinsulinism (e.g., sulfonyl urea), incretin effects after bariatric surgery, and congenital hyperinsulinism. Insulin (test code 561) immunoassay can be used to evaluate the etiology of hypo- or hyperglycemia but is not equivalent to the LC/MS/MS test. Combined with LC/MS/MS measurement of C-peptide in the Cardio IQ Insulin Resistance Panel with Score (test code 36509), the assay can also help evaluate the likelihood that an individual has clinically significant insulin resistance or help in differential diagnosis (e.g., insulinoma versus exogenous insulin administration(3). The results of this test should be interpreted in the context of pertinent clinical history and physical examination findings.

References
1. Cryer PE, Axelrod L, Grossman AB, et al. Evaluation and management of adult hypoglycemic disorders: an Endocrine Society Clinical Practice Guideline. J Clin Endocrinol Metab. 2009;94(3):709-728. doi:10.1210/jc.2008-1410
2. Kelly CT, Mansoor J, Dohm GL, et al. Hyperinsulinemic syndrome: the metabolic syndrome is broader than you think. Surgery. 2014;156(2):405-411. doi:10.1016/j.surg.2014.04.028
3. Abbasi F, Shiffman D, Tong CH, et al. Insulin resistance probability scores for apparently healthy individuals. J Endocr Soc. 2018;2(9):1050-1057. doi:10.1210/js.2018-00107


Performing Laboratory
Quest Diagnostics Nichols Institute-San Juan Capistrano, CA
33608 Ortega Highway
San Juan Capistrano, CA 92675-2042




The CPT Codes provided in this document are based on AMA guidelines and are for informational purposes only. CPT coding is the sole responsibility of the billing party. Please direct any questions regarding coding to the payor being billed. Any Profile/panel component may be ordered separately. Reflex tests are performed at an additional charge.