Insulin, Serum/Plasma — 4-Hour Post-Challenge Concentration
Measures insulin in blood after a challenge test, usually a glucose load, to evaluate how the body responds to rising blood glucose.
["This timed insulin test helps assess insulin production and glucose regulation during a challenge test."]
Key facts at a glance
- LOINC
- 27832-5
- Short code
- Insulin sp4 p chal SerPl-aCnc
- Synonyms
- Insulin sp4 p chal SerPl-aCnc
- 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 test measures the concentration of insulin in serum or plasma. The slug indicates that the sample is collected about four hours after a challenge, usually a glucose load.
Why might I need this test?
A timed insulin measurement may be used during glucose-tolerance testing to evaluate how the body handles a glucose load. It can provide information about insulin resistance, insulin production, and the risk or presence of abnormal glucose regulation.
How is the test performed?
A blood sample is collected at the specified time after you receive the challenge. The laboratory measures insulin in the serum or plasma, and your results are interpreted alongside glucose values and the rest of the challenge test.
How do I prepare for the test?
Follow the testing center's instructions exactly, including any required fasting period and the timing of the challenge. Do not change medications or eating habits for the test unless your clinician specifically directs you to do so.
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.
Higher-than-expected insulin after a glucose challenge may occur with insulin resistance, obesity, or other conditions affecting glucose regulation. Lower-than-expected insulin may suggest reduced insulin production, while unexpectedly elevated insulin with low glucose may indicate excess insulin or certain medications. Interpretation depends on the timing of the sample, the glucose results, medications, and the clinical situation.
Short name
4-hour post-challenge insulin
Frequently asked questions
Is this the same as a routine fasting insulin test?
Do I need to fast before this test?
Can medications or food affect the result?
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