Test Code: 4012CPT: 83527
|Use||Used to diagnose insulinoma, insulin resistance, cause of hypoglycemia, monitor insulin levels, determine type 2 diabetic medication times, and often ordered in conjunction with glucose and c-peptide tests.
Insulin is a hormone secreted by the beta cells of the pancreas. Insulin regulates the uptake and utilization of glucose, and is also involved in the regulation of protein synthesis and triglyceride storage. An increase in the amount of glucose in circulation stimulates insulin secretion. Insulin in turn stimulates the uptake of glucose into the tissues and inhibits the breakdown of glycogen in the liver. As the glucose level comes back to baseline so does insulin.1,2,3
|Clinical Utility||Diabetes has been divided into 2 major categories based on the secretion of insulin. The first is insulin dependent diabetes mellitus (IDDM) or Type I diabetes. It is brought on by the autoimmune destruction of the insulin secreting beta cells in the pancreas.4 Insulin secretion gradually declines to an insignificant level as ultimately all beta cells are destroyed. The patient must receive insulin injections in order to survive.
The second category is non-insulin dependent diabetes mellitus (NIDDM) or Type II. This disorder arises by an entirely different mechanism. Here, the beta cells can still secrete insulin but the body has developed resistance to the hormone.3 When the concentration of glucose in circulation rises, the insulin response is slow and of insufficient magnitude. As the disease progresses more and more insulin may be required to obtain the same level of glucose control. The patient may need to be placed on drugs which stimulate insulin secretion or be supplemented with insulin, depending on their degree
|Intended Patient Population||18+ and Older Adult Males & Females|
|Tube||Red, Green, Tiger|
|Volume||4mL Whole Blood (1mL Serum/Plasma)|
|Min Sample Volume||0.5 mLs|
|Reference Ranges||NON-FASTING - Not Established
FASTING M & F ≥ 18 yrs old; 1.90-23.00 uIU/mL
|Analytical Measurement Range||0.03-300.00 uIU/mL|
|Test Methodology||Chemiluminescent Immunoassay|
|Test Turnaround Time||3 Days|
|Limitations||Patients on insulin therapy are prone to the development of anti-insulin antibodies. These antibodies may interfere
with the assay.5
|Reject Criteria||Gross Hemolysis, Gross Lipemia|
|Laboratory Developed Test (LDT)||Yes|
|References||1. Howanitz PJ, Howanitz JH, Henry JB. Carbohydrates. Clinical Diagnosis and Management by Laboratory Methods
1991; 172-182. Edited by Henry JB, Philadelphia, W.B. Saunders Company.
2. Porte D Jr, Halter JB. The endocrine pancreas and diabetes mellitus. Textbook of Endocrinology 1981; 720-734. Edited by Williams, RH, Philadelphia, W.B. Saunders Company.
3. Kellen JA. Disorders of carbohydrate metabolism. Applied Biochemistry of Clinical Disorders 1986; 379-397. Edited
by Gornall AG, Philadelphia, J.B. Lippincott Company.
4. Atkinson MA, Maclaren NK. The pathogenesis of insulin-dependent diabetes mellitus. N Engl J Med 1994; 331:1853-1858.
5. Collins ACG, Pickup JC. Sample preparation and radioimmunoassay for circulating free and antibody-bound insulin concentrations in insulin-treated diabetics: A re-evaluation of methods. Diabetic Medicine 1985; 2: 456-460.