C-peptide

Disorders most common to insulin and c-peptide dysregulation include diabetes, insulinomas (a tumor of the pancreas that causes excess insulin to be produced), hypokalaemia, Cushing’s syndrome, and kidney disease. The measurement of plasma insulin, C-peptide and proinsulin concentrations have been identified as the most useful test in identifying causes of hyperglycemia (high blood glucose) such as Type 1 and Type 2 diabetes which are chronic metabolic diseases due either to a lack of insulin secretion or reduced insulin sensitivity. Overall, raised levels indicate endogenous hyperinsulinaemia, which is often seen in people with early-stage type 2 diabetes mellitus, and low levels indicate type 1 diabetes.