Insulin Suppression Test – C-peptide Serum

The Insulin Suppression Test – C-peptide Serum measures the levels of C-peptide in your blood before and after the administration of insulin. Following the insulin injection samples are collected at regular intervals, typically at 10, 20, 30, 40, 50, and 60 minutes.

This test is done for various reasons, including: • Diagnosing the cause of low blood sugar levels • Differentiating between type 1 and type 2 diabetes • Evaluating insulinoma (a tumour that produces excess insulin) • Assessing pancreatic function before and after pancreas transplant • Monitoring diabetes treatment effectiveness

Your doctor may recommend this test if you • Have symptoms of low blood sugar or high blood sugar. • Are diagnosed with diabetes at an early age. • Need to determine the type of diabetes. • Are considering or have undergone a pancreas transplant. • Require assessment of insulinoma or other disorders affecting insulin production.

Abnormal results may suggest conditions such as insulin deficiency or excess, insulin resistance, or pancreatic disorders.

During the test: • You will be asked to fast overnight. • Blood samples will be collected at baseline and at specific intervals after receiving insulin injections. • The process is minimally invasive and usually painless. • The test takes approximately one to two hours to complete, including the blood sample collection.

To prepare for the test: • Your doctor may advise you to fast for eight to twelve hours before the test. • Inform your doctor about any medications, including insulin, that you are currently taking. • Follow your doctor's instructions regarding medication and diet restrictions before the test. Please reach out to your healthcare provider for any specific requirements.

Other tests that may be ordered alongside the Insulin Suppression Test – C-peptide Serum include: • Fasting blood glucose: Measures your blood sugar levels after fasting to diagnose diabetes or assess its management • Haemoglobin A1c: Reflects long-term blood sugar control and helps diagnose and monitor diabetes • Glucose tolerance test: Evaluates how effectively your body processes glucose

C-peptide suppression test, C-peptide stimulation test

Insulin deficiency refers to a condition where the body does not produce enough insulin or cannot effectively use the insulin it produces. It is commonly seen in individuals with type 1 diabetes, certain pancreatic disorders, or as a result of medications or other medical conditions.