C-Peptide Stimulation by Glucagon Test: Booking, Price, and Results
About C-Peptide Stimulation by Glucagon Test: Booking, Price, and Results
| Field | Value |
|---|---|
| Also Known As | Glucagon-Stimulated C-Peptide Test, GST C-Peptide, C-Peptide Stimulation Test, Glucagon Stimulation Test for C-Peptide |
| Sample Type | Venous blood (serum) |
| Fasting Required | Yes, 8 to 12 hours of overnight fasting; water is permitted |
| Report Time | 2 Days |
| Recommended For | Adults and children of any gender; primarily prescribed for diabetes patients |
| Price | Starting at ₹4,200 |
What is a C-Peptide Stimulation by Glucagon Test?
The C-Peptide Stimulation by Glucagon Test is a specialised blood test that measures how well the pancreas produces insulin. It does this by injecting a hormone called glucagon to challenge the pancreas and then measuring a protein called C-peptide in the blood. Doctors use this test mainly to assess insulin secretion in people with diabetes or unexplained low blood sugar. The test is also known as the Glucagon-Stimulated C-Peptide Test or the C-Peptide Stimulation Test.
What Does a C-Peptide Stimulation by Glucagon Test Measure?
C-peptide is a small protein fragment released by the pancreas whenever it makes insulin. Because C-peptide and insulin are produced in equal amounts, measuring C-peptide gives an accurate picture of how much insulin your body is actually making.
| Parameter | What It Reflects |
|---|---|
| Fasting C-Peptide | Baseline insulin production by the pancreas before stimulation |
| Post-Stimulation C-Peptide | Pancreatic response after glucagon injection; peak measured at 6 minutes |
Why is a C-Peptide Stimulation by Glucagon Test Done?
A doctor may order this test for several reasons, ranging from confirming a diabetes diagnosis to checking whether a treatment plan is working.
Common Symptoms That May Require This Test
The following symptoms may prompt a doctor to request this test:
- Unexplained low blood sugar (hypoglycaemia), such as shakiness or confusion between meals
- Frequent urination and excessive thirst
- Unexplained weight loss
- Persistent fatigue without a clear cause
- Recurrent episodes of dizziness or feeling faint
- Rapid or irregular heartbeat (palpitations)
- Confusion, anxiety, or irritability
- Nausea and intense hunger
- Blurry vision
Conditions This Test Can Help Detect
This test can help identify or investigate a range of conditions. These include:
- Differentiating between Type 1 and Type 2 diabetes
- Insulinoma, a tumour of the pancreas that produces excess insulin
- Fasting hypoglycaemia (low blood sugar when not eating)
- Kidney failure and Cushing syndrome (a hormonal disorder)
- Factitious hypoglycaemia caused by excessive external insulin use
- Monitoring pancreatic or islet cell transplant function
C-Peptide Stimulation by Glucagon Test for Chronic Disease Monitoring
This test plays an important role in managing diabetes over time. In patients with diabetes, it can reveal whether the pancreas still has residual beta-cell function, which directly influences treatment decisions. Doctors may repeat this test periodically to assess whether a patient needs insulin therapy or whether existing treatment remains effective.
How to Prepare and What to Expect
Proper preparation for this test helps ensure accurate results. Here is what you need to know before your appointment.
Do You Need to Fast?
Yes, fasting is required. You should avoid eating or drinking anything other than water for 8 to 12 hours before the test. If you have a morning appointment, an overnight fast is suitable.
Practical Tips Before Your Test
Before your appointment, keep the following in mind:
- Bring a detailed clinical history, including your symptoms, previous test results, and any relevant medical records, as this is required for the test
- Avoid taking multivitamins or supplements containing biotin (vitamin B7) for at least 12 hours before sample collection
- Tell your doctor about all medications you are taking, especially diabetes medicines such as sulphonylureas (tablets that stimulate insulin release) or insulin injections
- Do not consume alcohol in the hours leading up to the test
- Wear loose-fitting clothing with easy access to your arm
Step-by-Step Procedure
The C-Peptide Stimulation by Glucagon Test procedure follows a clear sequence. Here is what to expect at the collection centre:
- A trained phlebotomist first draws a baseline blood sample from your arm after you have fasted overnight.
- A healthcare professional then administers an injection of glucagon (1 mg) either into a vein or into a muscle. Glucagon is a hormone that signals the pancreas to release insulin.
- A second blood sample is drawn six minutes after the injection, when C-peptide levels typically reach their peak.
- Both samples are collected in a serum gel tube and kept refrigerated until they reach the laboratory.
- The laboratory analyses the samples using an ECL or sandwich immunoassay technique, which detects C-peptide at very low concentrations.
- Your fasting and stimulated C-peptide values are compared to assess how well your pancreas responded.
Factors That Can Affect Accuracy
Several factors may influence the reliability of your results. Be sure to discuss these with your doctor:
- Blood glucose levels below 3.5 mmol/L can significantly suppress the pancreatic response to glucagon
- Recent use of biotin (vitamin B7) supplements may interfere with the immunoassay
- Kidney disease can raise C-peptide levels independently of insulin production
- Haemolysis (breakdown of red blood cells in the sample) may compromise sample quality
- Certain antibodies in the blood (heterophile antibodies) may interfere with test accuracy
Understanding Your C-Peptide Stimulation by Glucagon Test Results
Your results should always be reviewed alongside your medical history and other test findings. The table below provides general reference ranges, but only your doctor can interpret what these values mean for your specific situation.
| Parameter | Reference Range | Unit |
|---|---|---|
| Fasting C-Peptide | 0.5 to 2.0 | ng/mL |
| Fasting C-Peptide (SI units) | 0.17 to 0.83 | nmol/L |
| Post-Stimulation C-Peptide (6 min after glucagon) | 1.0 or above indicates an adequate response | ng/mL |
| Post-Stimulation C-Peptide (insulin dependency threshold) | 1.0 or below suggests insulin dependency | ng/mL |
These ranges are general guidelines. Your doctor will interpret your results based on your age, health history, and other factors. Always consult a qualified healthcare professional for personalised medical advice.
A strong rise in C-peptide after glucagon stimulation indicates that the pancreas can produce adequate insulin. A blunted or absent response suggests reduced beta-cell function.
High fasting C-peptide may point to insulin resistance, insulinoma, kidney failure, or the use of certain diabetes medications.
Low C-peptide often indicates Type 1 diabetes or a significant loss of insulin-producing capacity.
Results During Special Conditions
Certain health conditions can alter C-peptide results independently of actual insulin production.
Kidney disease can raise C-peptide levels by two to five times those of people with normal kidney function, even when the pancreas produces the same amount of insulin. This happens because the kidneys are responsible for clearing C-peptide from the blood.
Medications such as sulphonylureas, which are tablets that directly stimulate insulin release from the pancreas, can also increase C-peptide levels and should be reported to your doctor before testing.
How to Maintain Healthy Levels
General lifestyle habits can support healthy pancreatic function over time. These tips are for wellness awareness and are not a substitute for medical advice:
- Follow a balanced diet with sensible carbohydrate portions to avoid placing excess demand on insulin production
- Engage in regular physical activity, as this improves how efficiently your body uses insulin
- Take all prescribed diabetes medications consistently and attend scheduled follow-up appointments with your doctor
Lupin Diagnostics C-Peptide Stimulation by Glucagon Test Price and Home Collection
The C-Peptide Stimulation by Glucagon Test cost at Lupin Diagnostics starts at ₹4,200, and home collection is available across multiple cities. The city-wise prices below are indicative figures sourced from aggregator data.
| City | Approximate Price (₹) |
|---|---|
| BHOPAL | 4200 |
| CHENNAI | 4200 |
| HYDERABAD | 4200 |
| KOLKATA | 4200 |
| NAVI MUMBAI | 4200 |
| PUNE | 4200 |
Disclaimer: Prices are indicative and may vary by location. Please confirm the current price at the time of booking.
How to Book
- Select the test on the Lupin Diagnostics website.
- Choose your city and preferred time slot.
- Opt for home sample collection by a certified phlebotomist, or visit your nearest Lupin Diagnostics centre.
- Receive your report via email or WhatsApp within the stipulated turnaround time.
Home Collection
Lupin Diagnostics offers C-Peptide Stimulation by Glucagon Test home collection across cities through a network of trained phlebotomists. All samples are processed in NABL-accredited laboratories, ensuring reliable and consistent results. Your digital report is made available via email or WhatsApp once ready.
Frequently Asked Questions
A fasting C-peptide test measures your baseline insulin production after not eating for 8 to 12 hours. The C-Peptide Stimulation by Glucagon Test goes a step further by injecting glucagon to challenge the pancreas and reveal how well it can respond when greater insulin output is needed.
Glucagon is the preferred stimulant because it produces a reliable and reproducible response from functioning beta cells. It is the most widely used method for assessing residual insulin secretion due to its high sensitivity, standardised dosing, and well-established reference values.
The complete test typically takes 30 to 60 minutes. This includes the initial fasting blood draw, the glucagon injection, and the follow-up blood sample collected six minutes after the injection.
The test involves two standard blood draws and one injection, each of which may cause a brief sting or small bruise at the site. These effects usually resolve quickly. Some patients experience mild nausea after the glucagon injection.
Yes. Because C-peptide is only produced by the pancreas and is not present in injected insulin, the test accurately reflects your own insulin production regardless of whether you use external insulin. This makes it particularly useful for evaluating people already on insulin treatment.
Yes. The kidneys are primarily responsible for clearing C-peptide from the blood. In patients with moderate to severe kidney disease, C-peptide levels can be two to five times higher than in people with normal kidney function, even when actual insulin production has not changed.
Measuring C-peptide after glucagon stimulation helps doctors assess how much insulin-producing capacity the pancreas still has. This is important for deciding whether a patient needs insulin therapy, whether current treatment is adequate, and for distinguishing between Type 1 and Type 2 diabetes in cases where the diagnosis is unclear.
C-Peptide Stimulation by Glucagon Test: Booking, Price, and Results
