Peptide fragment analysis of proinsulin (Serum/Plasma)
This test measures small peptide fragments derived from proinsulin, a precursor protein of insulin. It helps assess insulin production and potential insulin resistance.
["This test may help diagnose or monitor conditions affecting insulin regulation."]
Key facts at a glance
- LOINC
- 50465-4
- Short code
- C peptide sp5 SerPl-sCnc
- Synonyms
- C peptide sp5 SerPl-sCnc
- Category
- coagulation
- Sample
- serum
- Container
- Red-top tube (SST)
- Units
- N/A
- Ref low
- 0.8
- Ref high
- 1.2
- Critical range
- — – 5 N/A
- Fasting
- false
- Population
- adult
- Sex
- all
- Age range
- 18–65 years
- CPT
- 85610
- SNOMED
- 396252006
- Specimen volume
- 5 mL
- Stability
- Room temperature: 4h, Refrigerated: 24h, Frozen: 7d
- Hemolysis max
- 500
- Lipemia max
- 1000
- Icterus max
- 500
- TAT
- 4–24 hours
- Order
- routine
Why Is This Test Done?
Your healthcare provider may order this test if you have symptoms of diabetes, insulin resistance, or other metabolic disorders. It can also be used to evaluate how well insulin is being produced in the body.
How Is the Sample Collected?
A blood sample is taken from a vein in your arm. You may feel a small pinch when the needle is inserted, but the procedure usually takes less than five minutes.
What Should You Expect Before the Test?
Avoid eating or drinking anything for at least 8–12 hours before the test, as fasting may be required to ensure accurate results. Let your healthcare provider know about any medications you’re taking, as some may affect the test results.
What Do the Results Mean?
Elevated levels of these peptide fragments might suggest insulin resistance or impaired insulin production, while normal levels generally indicate healthy insulin function. Your results will be interpreted by a healthcare professional based on your overall health and medical history.
Reference range
INR: 0.8-1.2 (warfarin: 2.0-3.0)N/A
Inform your healthcare provider if you are taking blood thinners. No special preparation required.
Clinical interpretation
How abnormal results are interpreted and what conditions they suggest.
Clinical Significance: This test is particularly useful in diagnosing or monitoring conditions like type 2 diabetes, prediabetes, or insulinoma (a rare tumor affecting insulin production). It helps differentiate between normal insulin production and conditions where insulin may not function properly, aiding in personalized treatment planning.
Short name
Proinsulin Peptide Levels
Frequently asked questions
Why might my doctor recommend this test?
How long will it take to get my results?
Can I eat or drink before this test?
Sources
- 1
- 2Lab Tests OnlineSource
- 3
Click any link to access the full source. PubMed Central (PMC) links provide free full-text access.
This information is for educational purposes only and is not a substitute for professional medical advice, diagnosis, or treatment.
This content is for general informational and educational purposes only and is not a substitute for professional medical advice, diagnosis, or treatment. Always seek the guidance of a qualified healthcare provider with any questions you have about a medical condition, and never disregard professional medical advice or delay seeking it because of something you read here.
If you think you may have a medical emergency, call your local emergency number or go to the nearest emergency department immediately.
Medically reviewed by WellAlly Editorial Team Last reviewed August 16, 2026. · Read our editorial policy