Proinsulin, Serum/Plasma — 1-Hour Post-Challenge Substance Concentration
Measures proinsulin in blood one hour after a glucose challenge to help assess pancreatic beta-cell function and insulin production.
["This timed proinsulin test helps evaluate insulin-related pancreatic function when interpreted with glucose and other insulin tests."]
Key facts at a glance
- LOINC
- 27956-2
- Short code
- Proinsulin 1h p chal SerPl-sCnc
- Synonyms
- Proinsulin 1h 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?
Proinsulin is a precursor made by the pancreas before it is processed into insulin. This test measures the amount of proinsulin in serum or plasma one hour after a glucose challenge.
Why might I need this test?
Your clinician may order this test to evaluate how the pancreas responds to glucose and produces insulin. It may be used when diabetes, prediabetes, or other disorders of glucose metabolism are being investigated.
How is the test performed?
You consume a measured glucose-containing drink, and a blood sample is collected exactly one hour later. The laboratory measures proinsulin in the serum or plasma.
How do I prepare for the test?
Follow your clinician's instructions about fasting and the glucose challenge. The test depends on accurate timing, so report any vomiting, acute illness, or inability to complete the challenge to the testing staff.
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.
Proinsulin results are interpreted together with the one-hour glucose, insulin, and sometimes C-peptide results. An abnormal pattern may indicate difficulty producing or releasing insulin, impaired glucose tolerance, or other changes in glucose metabolism, but it does not establish a diagnosis by itself.
Short name
1-Hour Post-Challenge Proinsulin
Frequently asked questions
Is this the same as a routine insulin test?
Why is the one-hour collection time important?
Does an abnormal proinsulin 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