C-Peptide Response to Glucose, 7 Specimens

Test Code

15847

CPT Code(s)

84681 (x7)

Test Code

15847

CPT Code(s)

84681 (x7)

Not offered in Quest Diagnostics Nichols Institute (IFD) – San Juan Capistrano. Please provide SERVICE AREA INFORMATION to find available tests you can order.

In-home collection is not available in your area through Quest Mobile.

Clinical Significance

C-Peptide Response to Glucose, 7 Specimens - 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.

Test Resources

None found for this test
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Test Details

Patient Preparation

Patients should fast 12 hours prior to collection

Methodology

Immunoassay (IA)

Reference Range(s)

Fasting	0.80-3.85 ng/mL
30 Minutes Post Glucose	1.78-7.49 ng/mL
60 Minutes Post Glucose	1.91-8.21 ng/mL
90 Minutes Post Glucose	1.52-7.95 ng/mL
120 Minutes Post Glucose	1.19-6.04 ng/mL
150 Minutes Post Glucose	1.06-5.98 ng/mL
180 Minutes Post Glucose	1.06-3.88 ng/mL
240 Minutes Post Glucose	0.86-3.22 ng/mL
300 Minutes Post Glucose	0.86-2.50 ng/mL

LOINC® Codes, Performing Laboratory

Service Area must be determined

Patient Preparation

Patients should fast 12 hours prior to collection

Methodology

Immunoassay (IA)

Reference Range(s)

Fasting	0.80-3.85 ng/mL
30 Minutes Post Glucose	1.78-7.49 ng/mL
60 Minutes Post Glucose	1.91-8.21 ng/mL
90 Minutes Post Glucose	1.52-7.95 ng/mL
120 Minutes Post Glucose	1.19-6.04 ng/mL
150 Minutes Post Glucose	1.06-5.98 ng/mL
180 Minutes Post Glucose	1.06-3.88 ng/mL
240 Minutes Post Glucose	0.86-3.22 ng/mL
300 Minutes Post Glucose	0.86-2.50 ng/mL

LOINC® Codes, Performing Laboratory

Service Area must be determined

Preferred Specimen(s)

1 mL serum per specimen

Minimum Volume

0.5 mL per specimen

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.
Reference ranges available: Fasting, 30, 60, 90, 120, 150, 180, 240 and 300 minutes post glucose.

Transport Container

Transport tube(s)

Transport Temperature

Room temperature

Specimen Stability

Room temperature: 4 days
Refrigerated: 7 days
Frozen -20° C: 7 days
Frozen -70° C: Not available

Reject Criteria

Gross hemolysis • Plasma

Setup Schedule

Service Area must be determined

Preferred Specimen(s)

1 mL serum per specimen

Minimum Volume

0.5 mL per specimen

Collection Instructions

Transport Container

Transport tube(s)

Transport Temperature

Room temperature

Specimen Stability

Room temperature: 4 days
Refrigerated: 7 days
Frozen -20° C: 7 days
Frozen -70° C: Not available

Reject Criteria

Gross hemolysis • Plasma

Setup Schedule

Service Area must be determined

Not offered in Quest Diagnostics Nichols Institute (IFD) – San Juan Capistrano. Please provide SERVICE AREA INFORMATION to find available tests you can order.

In-home collection is not available in your area through Quest Mobile.

Test Details

Clinical Significance

Test Resources

Reference ranges are provided as general guidance only. To interpret test results use the reference range in the laboratory report.

The CPT codes provided are based on AMA guidance and are for informational purposes only. CPT coding is the sole responsibility of the billing party. Please direct any questions regarding coding to the payer being billed.

This material contains content from LOINC® (http://loinc.org). The LOINC Table, LOINC Table Core are copyright © 1995-2019, Regenstrief Institute, Inc. and the Logical Observation Identifiers Names and Codes (LOINC) Committee and is available at no cost under the license at http://loinc.org/license.

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