C‑Peptide Response to Glucose, 6 Specimens
Use
C‑Peptide measurement after glucose administration helps evaluate pancreatic beta‑cell function, distinguishes type 1 from type 2 diabetes, monitors islet cell or pancreatic transplantation, and helps differentiate endogenous versus exogenous insulin sources in hyperinsulinemic hypoglycemia situations. This ordered sequence of timed specimens post–oral glucose provides a glucose-stimulated profile of C‑peptide response.
Special Instructions
Patients should fast prior to the test. Draw fasting specimen, administer oral glucose (1.75 g/kg body weight or 75 g maximum), then collect six timed serum specimens per protocol. Clearly label each tube with draw time and submit with one requisition.
Limitations
Gross hemolysis and plasma specimens are unacceptable; hemolyzed or plasma specimens may interfere with immunoassay measurement.
Methodology
Immunoassay
Biomarkers
Result Turnaround Time
3-5 days
Related Documents
For more information, please review the documents below
Specimen
Serum
Volume
1 mL per specimen
Minimum Volume
0.5 mL per specimen
Container
serum tube
Collection Instructions
Draw fasting specimen. Administer oral glucose solution. Collect timed specimens labeled with time drawn.
Patient Preparation
Patients should fast 12 hours prior to collection
Causes for Rejection
Gross hemolysis • Plasma
Stability Requirements
| Temperature | Period |
|---|---|
| Room Temperature | 4 days |
| Refrigerated | 7 days |
Other tests from different labs that may be relevant