C-peptide (C-PR)

C-peptide, also known as a linker peptide, is a secreted product of islet beta cells, which shares a common precursor with insulin, proinsulin. A molecule of proinsulin is cleaved into a molecule of insulin and a molecule of C peptide. Do not eat too greasy, high-protein foods the day before the blood draw, avoid heavy drinking. The alcohol content in the blood directly affects the test results. Basic Information Specialist classification: growth and development check classification: biochemical examination Applicable gender: whether men and women apply fasting: fasting Analysis results: Below normal: In patients with hypoglycemia caused by excess exogenous insulin, serum insulin is elevated and C-peptide is decreased. Normal value: C peptide (adult): 1.4-5.5μg/L Above normal: In patients with diabetes and islet B cell tumors, serum islet and C-peptide concentrations were elevated. negative: Positive: Tips: After 8 pm on the day before the medical examination, you should start fasting for 12 hours, so as not to affect the test results. Normal value Adult ≤4.0μg/L (≤4.0ng/ml) >60 years old male 1.5 ~ 5.0μg / L (1.5 ~ 5.0ng / ml) Female 1.4 ~ 5.5μg / L (1.4 ~ 5.5ng / ml) Clinical significance It is often measured simultaneously with insulin and OGTT (oral glucose tolerance assay). 1, low blood sugar (1) Patients with diabetes and islet B cell tumors have elevated serum islet and C-peptide concentrations. (2) In patients with hypoglycemia caused by excess exogenous insulin, serum insulin is elevated and C-peptide is decreased. (3) After the islet B cell tumor, the serum C-peptide is still high, suggesting that the tumor has not completely resected or has recurrence. 2. The serum C-peptide of cirrhosis is elevated, and the C-peptide/insulin ratio is decreased. 3. When insulin antibodies are present in diabetes, only C-peptide detection is used to understand islet B cell function. Low results may be diseases: high results in children with diabetes may be diseases: hypoglycemia, hypoglycemia in the elderly First, the precautions before blood draw 1, do not eat too greasy, high-protein food the day before the blood, to avoid heavy drinking. The alcohol content in the blood directly affects the test results. 2. After 8 pm on the day before the medical examination, you should start fasting for 12 hours to avoid affecting the test results. 3, should relax when taking blood, to avoid the contraction of blood vessels caused by fear, increase the difficulty of blood collection. Second, should pay attention after blood draw 1. After blood is drawn, local compression is required at the pinhole for 3-5 minutes to stop bleeding. Note: Do not rub, so as not to cause subcutaneous hematoma. 2, the pressing time should be sufficient. There is a difference in clotting time for each person, and some people need a little longer to clotting. Therefore, when the surface of the skin appears to be bleeding, the compression is stopped immediately, and the blood may be infiltrated into the skin due to incomplete hemostasis. Therefore, the compression time is longer to completely stop bleeding. If there is a tendency to bleed, the compression time should be extended. 3, after the blood draw symptoms of fainting such as: dizziness, vertigo, fatigue, etc. should immediately lie down, drink a small amount of syrup, and then undergo a physical examination after the symptoms are relieved. 4. If there is localized congestion, use a warm towel after 24 hours to promote absorption. 3. Please inform the doctor about the recent medication and special physiological changes before the test. Inspection process The radioactive label 125I-CP and the C-peptide in the specimen (or standard) are competitively bound to the limited C-peptide antibody. After equilibration, the separating agent is added to determine the radioactivity in the precipitate, which is negative with the C-peptide content in the specimen. Related.