Insulin
Code:
INS
Sample Type:
Serum (Gold Top)
Minimum volume: 1 mL
Ref Ranges/Units:
Fasting range 2.6 – 24.9 mU/L
Insulin should be interpreted taking into account the fasting status, concomitant glucose level and clinical status.
Turnaround:
1-2 weeks
Stability:
4 hours at 20‑25°C
2 days at 2‑8°C
6 months at ‑20°C
Freeze only once
Special Precautions/Comments:
Unstable sample, please send to laboratory urgently.
Assay is specific for human insulin and may not detect exogenous insulin preparations.
Additional Information:
Insulin is a hormone produced by beta-cells of the islets of Langerhaans in the pancreas which acts to decrease blood glucose levels. It achieves this by stimulating cellular uptake of glucose via GLUT4, utilising glucose in glycolysis to produce energy, and storage of excess glucose via glycogen synthesis. Insulin also inhibits glycogenolysis and gluconeogenesis.
Measurement of insulin is mainly used in the investigation of hypoglycaemia or to differentiate between insulin-deficient diabetes (type 1) and insulin-resistant diabetes (type 2). It can also be useful in assessing the need to initiate insulin therapy in patients with type 2 diabetes.
Proinsulin is cleaved to form insulin and C-peptide in equimolar concentrations. C-peptide has a longer half-life than insulin, and therefore can be used as a more reliable marker of endogenous insulin production.
South of Tyne & Wear Pathology Centre
