What is the C-peptide test used for?
A C-peptide test may be useful in the following situations:
Determine the cause of hypoglycemia (low blood sugar)
High insulin levels have been linked to some types of hypoglycemia. A C-peptide test can determine whether the ailment is caused by an excess of insulin. Hypoglycemia can be caused by various factors, including:
MalnutritionLiver disease or kidney diseaseSide effects from certain diabetes medicines, including insulin.Drinking too much alcohol without eatingA tumor in the pancreas (uncommon)- Malnutrition
- Liver disease or kidney disease
- Side effects from certain diabetes medicines, including insulin.
- Drinking too much alcohol without eating
- A tumor in the pancreas (uncommon)
Manage diabetes treatment
Knowing how much insulin the pancreas is producing that could affect treatment choices if patients have type 1 or type 2 diabetes. Even if people take insulin to treat diabetes, a C-peptide test can still give accurate results. This is because the level of insulin your pancreas produces affects the C-peptide levels. The insulin you take has no impact on them
Monitor treatment
Track the progress of the insulinoma treatment for a tumor in the pancreas (uncommon). These tumors overproduce insulin, which lowers blood sugar levels. They can typically be removed through surgery and are always benign.
If you're not sure if you have type 1 or type 2 diabetes and want to find out
The kind of diabetes that you have can typically be identified by the doctor. However, it's not always easy to be sure. If the diabetes diagnosis is still questionable three years later, a C-peptide test may be necessary.
What is the need for a C-Peptide Test?
A C-peptide test may be required if:
- You have hypoglycemia (low blood sugar) but are unsure of the cause.
- You have diabetes, and you:
- Take insulin, and the doctor is considering modifying the treatment.
- Have type 2 diabetes, and the doctor wants to see if you should begin taking insulin.
- Have hypoglycemia, which could result from too many diabetes medications.
- You've been told you have a pancreatic tumor (insulinoma). A C-peptide test can aid in the monitoring of the disease and therapy.
What happens during a C-peptide test?
A blood sample is usually used in a C-peptide test. However, the test may be performed on a sample of all the urine taken over a 24-hour period. A blood test involves a healthcare provider drawing blood from a vein in the arm with a tiny needle. After the insertion of the needle, a small amount of blood will be collected in a test tube or vial. When the needle goes in or out, people may feel a slight sting. This normally takes under five minutes. Individuals will be given a special container to collect the urine and instructions on collecting and storing the samples for a 24-hour urine sample test. The service provider will advise you when to begin. The following steps are usually included in the test:
- To begin, urinate as usual in the toilet. This urine should not be collected. Make a note of the time you urinate.
- Collect all of your urine in the container for the next 24 hours.
- Keep the urine container in a refrigerated or ice-filled cooler during collection time.
- If you can, try to urinate 24 hours after starting the test. This is the test's final urine collection.
- As directed, return the bottle containing your urine to the provider's office or the laboratory.
How do I prepare for the test?
Before a C-peptide blood test, you might need to fast (not eat or drink any) for 8–12 hours. Talk with your healthcare provider about whether there are any special instructions you must follow before a blood or urine test.
Are there any risks to the test?
A blood test poses very little risk. Patients may experience some pain or bruising where the needle was inserted, but most symptoms subside quickly.
What do the results mean?
The significance of the results is determined by the age, health, medications, and the results of additional tests, such as a blood glucose test. A high C-peptide level usually indicates that the body produces too much insulin. High insulin levels are caused by various conditions, including:
- Cushing's syndrome
- Kidney failure
- Type 2 diabetes
- Insulinoma
- A low level of potassium in the blood
A low C-peptide level may indicate that the body isn't producing enough insulin. Low insulin levels can be caused by various conditions, including:
- A severe infection
- Type 1 diabetes and, in some cases, type 2 diabetes
- Taking too much insulin to treat diabetes
- Liver disease
- Addison disease
A drop in C-peptide levels indicates that the treatment for an insulin-producing tumor in the pancreas is effective. A rise in C-peptide may indicate that the tumor has returned. Speak with the provider if you have any questions regarding the outcomes.
Do I need to know anything else about a C-peptide test?
Diabetes cannot be identified using a C-peptide test. Diabetes is detected and diagnosed using additional procedures, including blood glucose and urine glucose analysis.
