Understanding Your C-Peptide Test (Fasting)
Preparation: For this test, you'll need to fast overnight, which means no food or drink (except water) for 8-12 hours before the test.
What It Is: A C-peptide test measures the amount of C-peptide in your blood or urine. This test helps healthcare providers determine if you have Type 1 or Type 2 diabetes and how well your diabetes treatment is working. It also checks if your pancreas is producing insulin.
Why It's Important: This test can:
Diagnose conditions like pancreatic cancer, kidney failure, Cushing syndrome, or Addison disease.
Differentiate between the body's natural insulin production and insulin from medications.
What C-Peptide Is: When your pancreas makes insulin, it also releases a substance called C-peptide into your body. They are produced in equal amounts. Insulin is crucial because it regulates blood sugar levels, ensuring your body gets the energy it needs.
Type 1 vs. Type 2 Diabetes:
Type 1 Diabetes: The pancreas can't make insulin, so people need insulin injections to help their body use glucose.
Type 2 Diabetes: The body either doesn't produce enough insulin or resists its effects. Some people may need medications to help their bodies use glucose. Over time, some may stop producing insulin altogether.
Why the Test Matters: Since C-peptide is a byproduct of insulin production, this test can show how much insulin your body is making. It helps distinguish between insulin made by your body (endogenous) and insulin from medications (exogenous).
What It Can't Do: A C-peptide test alone can't determine if you have diabetes. It only indicates if your body can produce its own insulin.