Proinsulin, Serum/Plasma — 2-Hour Post-Challenge, Substance Concentration
A timed blood test measures proinsulin, a precursor of insulin, in serum or plasma, usually two hours after a specified meal or glucose load.
["This test helps assess how the pancreas produces and releases insulin in response to a glucose load."]
Key facts at a glance
- LOINC
- 27856-4
- Short code
- Proinsulin 2h p chal SerPl-sCnc
- Synonyms
- Proinsulin 2h p chal SerPl-sCnc
- Category
- hormone
- Sample
- serum
- Container
- Red-top tube (SST)
- Units
- N/A
- Ref low
- 2.6
- Ref high
- 24.9
- Fasting
- false
- Population
- adult
- Sex
- all
- Age range
- 18–65 years
- CPT
- 83525
- SNOMED
- 413618004
- 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
What is this test?
This blood test measures proinsulin, a substance made by the pancreas that is converted into insulin. The “2-hour” designation means the sample is intended to be collected two hours after the meal or glucose challenge specified by your clinician.
Why might I need this test?
It may be used to evaluate pancreatic beta-cell function, particularly when insulin production or glucose regulation is being assessed. Results are often interpreted together with glucose, insulin, and other diabetes tests.
How is the test performed?
A blood sample is drawn from a vein and the liquid portion, serum or plasma, is analyzed for proinsulin. This is usually a timed sample, so the exact collection time and the preceding meal or glucose load are important.
How do I prepare for the test?
Follow your clinician’s instructions about fasting, eating, and any glucose challenge. Record the time of the meal or glucose load and the time of the blood draw, and tell the laboratory staff if you have recently eaten or taken diabetes medication.
Reference range
Fasting: 2.6-24.9 μIU/mLN/A
No special preparation usually required. Stay well hydrated. Inform your healthcare provider of all medications and supplements you are taking.
Clinical interpretation
How abnormal results are interpreted and what conditions they suggest.
An elevated or disproportionate proinsulin level may indicate that the pancreas is producing more proinsulin relative to fully formed insulin, which can occur with impaired beta-cell function or abnormal glucose regulation. Interpretive changes may also be associated with pancreatic disease and reduced kidney function. The result should be reviewed with related glucose and insulin measurements because proinsulin alone does not diagnose a specific condition.
Short name
2-hour proinsulin
Frequently asked questions
What does proinsulin measure?
Why is the collection time important?
Does an abnormal result mean I have diabetes?
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