Insulin Suppression test For C-peptide 7 samples Test

C-peptide is a substance produced by the beta cells in the pancreas when proinsulin splits apart and forms one molecule of C-peptide and one molecule of insulin. Insulin helps the body use and control the amount of sugar (glucose) in the blood. A C-peptide test measures the amount of insulin by measuring the amount of this peptide in the blood, since the level of C-peptide in the blood can show how much insulin is being made by the pancreas. This test can be done when diabetes has just been found and there is no clarity over which type of diabetes it is. A person whose pancreas does not make any insulin (type 1 diabetes) has a low level of insulin and C-peptide. A person with type 2 diabetes can have a normal or high level of C-peptide.

It is recommended that you should either wear a sleeve-less or a short-sleeved shirt to make it easier for you and the technician who will be drawing the blood. Wearing a shirt with full- sleeves that can easily be rolled-up is also fine. You may be asked to stop eating and drinking for 8 hours before this blood test. Insulin and some oral medicines used to treat type 2 diabetes can change the test results. Your doctor may ask you to stop these medicines before your blood test.

A high level of C-peptide generally indicates a high level of endogenous insulin production. This may be in response to a high blood glucose caused by glucose intake and/or insulin resistance. A high level of C-peptide is also seen with insulinomas and may be seen with low blood potassium, Cushing syndrome, and renal failure. When used for monitoring, decreasing levels of C-peptide in someone with an insulinoma indicate a response to treatment; levels that are increasing may indicate a tumor recurrence. A low level of C-peptide is associated with a low level of insulin production. This can occur when insufficient insulin is being produced by the beta cells, with diabetes for example, or when production is suppressed by treatment with exogenous insulin.

A band is wrapped around the arm, 3-4 inches above the collection site (superficial vein that lies within the elbow pit) A 70% alcohol pad is used to clean the skin A needle is then kept in line with and injected into a vein that can be seen from the skin The blood is dragged out from the needle by a nozzle, saved in a vessel and sealed with your name The sample is then taken to a lab for examination