C-peptide (C-Peptide)
The test determines the level of C-peptide — a compound formed when proinsulin is split into active insulin. Allows assessment of endogenous insulin secretion and pancreatic beta-cell functional state. Used to diagnose type 1 and type 2 diabetes, hypoglycemic conditions, and to differentiate insulin-dependent from insulin therapy patients.
What the test evaluates:
- Endogenous insulin level (through C-peptide measurement)
- Pancreatic beta-cell function
- Insulin therapy efficacy and possible insulin overdose
Biomaterial: Venous blood (serum)
- Draw blood fasting
- Exclude physical activity, stress, alcohol, caffeine 24 hours before
- Still water is permitted
Medications:
- Insulin, hypoglycemic drugs, hormonal agents may affect results
- Medication discontinuation only by physician agreement
Recommended for:
- Diabetes and carbohydrate metabolism disorders
- Suspected insulin resistance or metabolic syndrome
- Suspected insulinoma or pancreatic tumors
- Assessing dietary effect on endogenous insulin
Elevated level: may indicate insulin resistance, Cushing's syndrome, or insulinoma
Reduced level: indicates reduced beta-cell secretion, typical of type 1 diabetes or after pancreatectomy
Results should be interpreted together with glucose, insulin, and other carbohydrate metabolism markers.
