Insulin, Intact, LC/MS/MS Quest

Insulin, Intact, LC/MS/MS - 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.