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Test Code LAB0206060 Insulin, Serum

Additional Codes

Mayo Test ID
INS

Performing Laboratory

Mayo Clinic Laboratories in Rochester

Useful For

Diagnosing insulinoma, when used in conjunction with proinsulin and C-peptide measurements

 

Management of diabetes mellitus

Method Name

Electrochemiluminescence Immunoassay (ECLIA)

Reporting Name

Insulin, S

Specimen Type

Serum


Ordering Guidance


Patients on insulin therapy may develop anti-insulin antibodies. These antibodies may interfere in the assay system, causing inaccurate results. In such individuals, measurement of free insulin INSFT / Insulin, Free and Total, Serum should be performed.



Specimen Required


Patient Preparation:

1. Patient should be fasting.

2. For 12 hours before specimen collection do not take multivitamins or dietary supplements containing biotin (vitamin B7), which is commonly found in hair, skin, and nail supplements and multivitamins.

Supplies: Sarstedt 5 mL Aliquot Tube (T914)

Collection Container/Tube:

Preferred: Serum gel

Acceptable: Red top

Submission Container/Tube: Plastic vial

Specimen Volume: 1 mL

Collection Instructions:

1. Avoid hemolysis

2. Label specimens with corresponding collection times.

3. Centrifuge and aliquot serum into plastic vial within 2 hours of collection.

Additional Information: If multiple specimens are drawn, send separate order for each specimen.


Specimen Minimum Volume

0.75 mL

Specimen Stability Information

Specimen Type Temperature Time Special Container
Serum Frozen (preferred) 180 days
  Refrigerated  7 days

Reject Due To

Gross hemolysis Reject
Gross lipemia OK
Autopsy specimen Reject

Reference Values

2.6-24.9 mcIU/mL

 

For SI unit Reference Values, see https://www.mayocliniclabs.com/order-tests/si-unit-conversion.html

Interpretation

During prolonged fasting, when the patient's glucose level is reduced to <40 mg/dL, an elevated insulin level plus elevated levels of proinsulin and C-peptide suggest insulinoma.

 

Insulin levels generally decline in patients with type 1 diabetes mellitus.

 

In the early stage of type 2 diabetes, insulin levels are either normal or elevated. In the late stage of type 2 diabetes, insulin levels decline.

 

In normal individuals, insulin levels parallel blood glucose levels.

 

To compare insulin and C-peptide concentrations (ie, insulin to C-peptide ratio):

-Convert insulin to pmol/L: insulin concentration in mcIU/mL x 6.945 = insulin concentration in pmol/L.

-Convert C-peptide to pmol/L: C-peptide concentration in ng/mL x 331 = C-peptide concentration in pmol/L.

Day(s) Performed

Monday through Friday

Report Available

1 to 3 days

Specimen Retention Time

14 days

Test Classification

This test has been cleared, approved, or is exempt by the US Food and Drug Administration and is used per manufacturer's instructions. Performance characteristics were verified by Mayo Clinic in a manner consistent with CLIA requirements.

CPT Code Information

83525

LOINC Code Information

Test ID Test Order Name Order LOINC Value
INS Insulin, S 27873-9

 

Result ID Test Result Name Result LOINC Value
INS Insulin, S 27873-9