C-Peptide, Four Specimens
Use
The C-Peptide test is used to measure the level of insulin production by the pancreas. C-Peptide is a byproduct of insulin production and provides indirect insight into pancreatic function. This test is commonly performed to evaluate patients with suspected insulinoma, to distinguish between type 1 or type 2 diabetes, and to assess endogenous insulin production in patients taking exogenous insulin. The 'Four Specimens' panel allows for detailed temporal assessment by collecting multiple samples over time, typically in response to treatment or glucose challenge. This dynamic assessment aids clinicians in tailoring diabetes management and monitoring treatment efficacy.
Special Instructions
Not provided.
Limitations
This test may exhibit interference when the sample is collected from individuals taking high doses of biotin (vitamin B7, B8, or coenzyme R). It is crucial to ask patients about biotin supplementation to avoid compromised results. Additionally, the test may have limitations in settings where insulin antibodies are present or in post-prandial (after eating) states due to variations in C-Peptide levels. Interpretation should consider timing, clinical context, and other testing such as fasting status.
Methodology
Automated Analyzer (Clinical Chemistry)
Biomarkers
LOINC Codes
- 57376-6 - C peptide BS SerPl-mCnc
- 13032-8 - C peptide sp2 p chal SerPl-mCnc
- 13033-6 - C peptide sp3 p chal SerPl-mCnc
- 13034-4 - C peptide sp4 p chal SerPl-mCnc
Result Turnaround Time
1-2 days
Related Documents
For more information, please review the documents below
Specimen
Serum
Volume
Not provided
Minimum Volume
Not provided
Container
Collection tube, specify timing of sample
Patient Preparation
Discontinue biotin supplements 72 hours before collection.
Causes for Rejection
Hemolysis, improper container, mislabeled or unlabeled specimens
Other tests from different labs that may be relevant