C-Peptide

Test Code

CPEPT

Alias/See Also

CPEP

CPT Codes
84681

Preferred Specimen

Serum (gold or red top tube)

Minimum Volume

0.5 mL

Transport Container

Serum (gold or red top) Tube

Transport Temperature

Room Temperature or Refrigeration

Specimen Stability

Room Temperature - 8 hours; Refrigerated - 24 hours

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

Quantity Not Sufficient, EDTA (purple top tube) contamination, IV contamination

Methodology
Chemiluminescence

Setup Schedule

Daily upon receipt

Report Available

Upon completion of analysis

Reference Range

0.48 - 5.05 ng/mL

Clinical Significance

C-peptide measurement, in conjunction with blood glucose and insulin levels, aids in the differential diagnosis of hypoglycemia. C-peptide levels can be important in diagnosing overzealous insulin treatment since C-peptide does not exist in commercial insulin preparations. In this case, as well as in patients with detectable insulin autoantibodies and postprandial hyperglycemia, insulin levels will be elevated and C-peptide levels will be low. In insulinomas and beta-cell tumors, C-peptide is increased. Also, C-peptide measurement is used for the evaluation of fasting hypoglycemia, and C-peptide therapy is administered to type 1 diabetic patients, who are normally C-peptide deficient.

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.