C-Peptide

Test Code
372


Alias/See Also
LAB521


CPT Codes
84681

Preferred Specimen
1 mL serum


Patient Preparation
Patient should fast 12 hours prior to collection

Minimum Volume
0.5 mL


Transport Container
Transport tube


Transport Temperature
Room temperature


Specimen Stability
Room temperature: 4 days
Refrigerated: 7 days
Frozen: 7 days


Reject Criteria (Eg, hemolysis? Lipemia? Thaw/Other?)
Gross hemolysis • Plasma


Methodology
Immunoassay (IA)

Setup Schedule
Tues, thurs, sat


Report Available
6 days


Reference Range
0.80-3.85 ng/mL


Clinical Significance
C-Peptide is useful in the evaluation of pancreatic beta cell function (e.g., helping distinguish type 1 from type 2 diabetes mellitus, or monitoring patients who have received islet cell or pancreatic transplants) and for determining the source of insulin in patients with hyperinsulinemic hypoglycemia (e.g., distinguishing insulin-secreting tumors from exogenous insulin administration). It is also sometimes measured as an additional means (more resistant to hemolysis than is insulin itself) for evaluating glucose tolerance tests.


Performing Laboratory
Quest Diagnostics Nichols Institute-San Juan Capistrano, CA
33608 Ortega Highway
San Juan Capistrano, CA 92675-2042




The CPT Codes provided in this document are based on AMA guidelines and are for informational purposes only. CPT coding is the sole responsibility of the billing party. Please direct any questions regarding coding to the payor being billed. Any Profile/panel component may be ordered separately. Reflex tests are performed at an additional charge.