C‑Peptide Response to Glucose, 2 Specimens
Use
C‑Peptide response to glucose testing is used to evaluate pancreatic β‑cell function, helping distinguish between type 1 and type 2 diabetes mellitus, assess endogenous versus exogenous insulin sources in hyperinsulinemic hypoglycemia, and evaluate glucose tolerance; it is more resistant to hemolysis than insulin itself, making it valuable in glucose tolerance testing contexts.
Special Instructions
Patients should fast for 12 hours prior to collection. Draw a fasting serum specimen, administer oral glucose (1.75 g/kg body weight, maximum 75 g), collect two timed post‑glucose serum specimens, clearly label with draw time, and submit both specimens with one requisition.
Limitations
Gross hemolysis and plasma submissions are unacceptable; only serum is suitable. Hemolysis may interfere with assay integrity.
Methodology
Immunoassay (Other)
Biomarkers
Result Turnaround Time
Not provided.
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
Transport tube(s)
Collection Instructions
Draw fasting specimen. Administer oral glucose solution (1.75 g/kg body weight or 75 g maximum). Collect 1 mL serum for each timed specimen post glucose dose. All tubes must be clearly marked with time drawn. Submit all tubes with one test requisition.
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 |
| Frozen | Not available |