C-peptide
Chemical Pathology
Notes
Measurement of C-peptide levels is indicated for:
- investigating fasting hypoglycaemia
- classification and management of patients with insulin treated diabetes
- monitoring purposes e.g. following pancreatectomy or pancreas/islet cell transplant.
As the main clinical role of the C-peptide in diabetes is identifying or excluding very severe insulin deficiency (present in longstanding type 1 diabetes >3-5 years depending on age of onset; and associated with an absolute requirement for insulin) the role of testing in non-insulin treated patients is limited.
Sample requirements
For C-peptide (and insulin analysis) a simultaneous glucose result is required for result interpretation.
For adults, blood taken into a 2mL EDTA tube plus blood collected into a 2mL fluoride-oxalate tube for laboratory glucose.
Storage/transport
Do not store but send immediately to the laboratory, as samples must be separated and serum/plasma frozen the same day as venepuncture.
Required information
Relevant clinical details including reason for the request, whether patient diabetic, fasting status and current medication.
Turnaround times
Samples are sent for analysis to an external referral laboratory, with results expected back within 2 weeks.
Reference ranges
Results are generally reported with an interpretative comment provided.
Further information
To learn more about C-peptide visit Lab Tests Online: C-peptide
To learn more about testing for diabetes subtypes visit Diabetesgenes.org
Page last updated 29/04/2024