what is cpeptide
A C-peptide test measures the level of this peptide in the blood. It is generally found in amounts equal to insulin because insulin and C-peptide are linked when first made by the pancreas.Insulin helps the body use and control the amount of sugar (glucose) in the blood.Insulin allows glucose to enter body cells where it is used for energy. The level of C-peptide in the blood can show how much insulin is being made by the pancreas. C-peptide does not affect the blood sugar level in the body.hy It Is Done. A C-peptide test is done to: 1  Help tell the difference between type 1 diabetes and type 2 diabetes. 2  Find the cause of low blood sugar (hypoglycemia). 3  Check to see whether a tumor of the pancreas (insulinoma) was completely removed.