Glucose, Insulin, and C-peptide levels measured during a triple bolus glucose tolerance test (serum/plasma)
This test evaluates how your body responds to glucose by measuring blood levels of glucose, insulin, and C-peptide after three carefully timed doses of glucose.
["Assesses insulin sensitivity and pancreatic function during controlled glucose exposure."]
Key facts at a glance
- LOINC
- 40335-2
- Short code
- GH 15M p Triple Bolus SerPl-mCnc
- Synonyms
- GH 15M p Triple Bolus SerPl-mCnc
- Category
- chemistry
- 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 This Test Is Done
A triple bolus glucose tolerance test (GTT) is often used to diagnose or monitor conditions like diabetes, prediabetes, or gestational diabetes. It helps doctors understand how your pancreas produces insulin and how your body responds to glucose over time. This test may also be used in research or specialized clinical settings to assess metabolic health in specific patient populations.
What to Expect During the Test
You’ll receive three small doses of glucose (sweet liquid) at set intervals while blood samples are drawn from a vein in your arm. The test typically lasts about 3 hours. You’ll need to stay seated and may be asked to avoid eating or drinking anything except water for a few hours beforehand.
Blood Sample Collection
Blood is drawn at multiple time points to measure glucose, insulin, and C-peptide levels. These analytes help assess how your body processes glucose and produces insulin. The test uses serum or plasma, depending on the lab’s method.
Preparation and Restrictions
Do not eat or drink anything (except water) for 8–12 hours before the test. Avoid caffeine, alcohol, or strenuous activity on the day of testing. Wear comfortable clothing and bring your ID and insurance info if required.
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 critical for diagnosing or managing diabetes and related metabolic disorders by providing detailed insights into glucose metabolism, insulin secretion, and pancreatic function. Abnormal results may indicate impaired glucose tolerance, insulin resistance, or other endocrine conditions requiring further medical evaluation.
Short name
Triple Bolus GTT (Serum/Plasma)
Frequently asked questions
What does a triple bolus GTT measure?
Why is this test different from a standard glucose tolerance test?
Can I eat or drink anything 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