Insulin - serum
Last updated: Wednesday, 17, March, 2004
| Item | Process |
|---|---|
| Specimen | 5 mL blood in EDTA (preferred) or a plain tube; must be separated and frozen immediately. Simultaneous plasma glucose levels are required for interpretation. |
| Method | Immunoassay. |
| Reference Interval | <5 mU/L during hypoglycaemia; 4-10 mU/L after 8 hour fast, and with a normal plasma glucose. |
| Application | Investigation of fasting hypoglycaemia and insulin resistant states. Neither insulin nor C-peptide assays are of value in the interpretation of a GTT. |
| Interpretation | Increased levels and increased insulin/glucose ratios are found with pancreatic islet beta cell hyperplasia or insulinomas. Non-insulin dependent diabetes mellitus and insulin therapy may also give high levels. To identify self-administration of insulin as a cause of hypoglycaemia, C-peptide assay is also required. See C-peptide. |
| Reference | Pourmotabbed G and Kitabchi AE. Obstet Gynecol Clin North Am. 200; 28(2): 383-400. |