|Description||A component of insulin synthesis which is released from the pancreas when insulin is secreted. Sample must be received in laboratory within 30 minutes of venepunture. A fluoride tube for glucose should also be sent. Insulin assays are provided for the diagnosis of hypoglycaemia and will only be measured in states of hypoglycaemia. Serum samples are recommended for C-peptide analysis as this allows for any follow up tests (e.g. IGF-2, sulphonylureas) to be performed on the same sample. Lithium heparin is acceptable.|
|Indication||Investigation of hypoglycaemia.
|Additional Info||Proteolytic cleavage of pro-insulin prior to secretion produces the mature insulin molecule and the connecting peptide (C-peptide). C-peptide is secreted in equimolar amounts to insulin but fasting concentrations are often higher due to its longer half-life. The C-peptide has no biological activity and is degraded and excreted by the kidneys.
|Concurrent Tests||Glucose, insulin.|
|Interpretation||Increased in insulinoma and type II diabetes. Decreased in type I diabetes and exogenous insulin administration.
|Collection Conditions||The lab should be notified that a sample has been taken and it should be sent to the lab immediately as it should preferably be separated and frozen within 30 minutes of phlebotomy.|
|Min. Vol||0.2 mL|
|Freq.||Referred to external laboratory|
|Ref. Range (Male)||0 - 5.2|
|Ref. Range (Female)|| |
|Ref. Range (Paed)|| |
|Ref. Range Notes||
|IP Acute TAT||Refer to Website|
|IP Routine TAT||At least 1 week|
|GP Acute TAT||Refer to Website|
|GP Routine TAT||Refer to Website|
|Turnround Comment||Dr G Wark:firstname.lastname@example.org|
Originally edited by : JHB. Review due on 22/11/2018 10:40:56. Published By SB on 22/11/2017 10:40:56.