C-peptide (Fasting) Test
C-peptide (Fasting)
C-peptide is a by-product that pancreas produce while making insulin. In general, pancreas produce equal amounts of C-peptide and insulin. Insulin is a hormone that regulates blood sugar (glucose) levels in the body, facilitating glucose absorption, and utilisation by cells in the muscles, liver, and fat.
The C-peptide test detects the presence of C-peptide in the blood or urine. Measuring the C-peptide is an accurate way of determining how much insulin is produced in the body by the pancreas. C-peptide has no effect on glucose levels in the body, but it remains for a longer duration in blood than insulin. As a result, it aids in accurately determining how much insulin is produced
What is C-peptide test used for?
A C-peptide test is required in the following conditions:
·      To classify the type of diabetes you have (type 1 or type 2)Â
·      To manage and monitor diabetes treatment
·      To determine if enough insulin is being produced in the body
·      To detect the cause of low blood sugar (hypoglycaemia)
·      To distinguish between the naturally produced insulin and one that is supplied from outside (injection form)
·      To check pancreatic cancer status (Rarely)
Who should get tested?
This test is indicated if you,
Have been diagnosed with low blood sugar
Have diabetes
Are diagnosed with pancreatic tumour
Need a change of diabetes medication
Need to start taking insulin
Test preparation:
A fasting blood sample is taken to test C-peptide in your blood. A minimum of 8-10 hours of fasting is generally recommended before taking this test. Your healthcare provider will draw blood from a vein in your arm and collect it in a sterile test tube for testing
Interpretation of results:
Normal ranges: 0.5 ng/mL to 2.0 ng/mL (nanograms per milli litres)
Deviations from the normal levels indicate:
The levels of C-peptide in the blood may be high or low based on the amount of insulin that your body produces.
·      A high C-peptide level usually indicates a condition that causes high insulin levels in the body, such as type 2 diabetes, Cushing's syndrome, insulinoma - a pancreatic tumour, kidney failure, and low potassium levels in the blood.
·      A low C-peptide level may indicate conditions that cause low insulin levels in the body, such as type 1 diabetes and, in some cases, type 2 diabetes, a severe infection, Addison disease, liver disease, or excessive insulin intake (causes pancreas to stop making its own insulin).
FAQs
Are there any risks associated with C-peptide testing?
No, there are no potential risks to C-peptide testing. It is a simple blood test and may cause a small sting or bruise during sample collection at the site of needle insertion. It usually resolves within few minutes to a couple of hours, at times
I had my snack 3 hours before test. Can I still take C-peptide test?
C-peptide test should be performed on an empty stomach, after fasting for at least 8 - 10 hours. Any deviations from the abovementioned fasting period may have an impact on the individual's accuracy of results. Therefore, it is recommended to try taking the test after fasting for more than 8 hours
3. My doctor is thinking of changing my diabetes medications. Do I need to undergo C-peptide testing?
C-peptide test is advised for a number of reasons. Among these are managing and monitoring the diabetes treatment plan. If your doctor intends to change your diabetes treatment plan, you may be advised to undergo a C-peptide test
What is the turnaround time (TAT) for C-peptide test?
The results of a C-peptide test are typically available 1 to 5 days after the sample is collected. It may, however, take a little longer than usual at times
I have diabetes but my C-peptide results show normal. What does it indicate?
Usually people with type 2 diabetes may show normal C-peptide results after the test. This could be either due to diabetes medication or a non-cancerous growth in the pancreas (insulinoma). C-peptide test can also help in determining the cause of low blood sugar levels (hypoglycemia) in the body
Related tests
Tests At Lupin Diagnostics