C-Peptide (Urine)

General Information

Urinary C-peptide measurement, together with measurement of urinary creatinine, may be used to calculate a Urine C-peptide Creatinine ratio (UCPCR).

Urine C-peptide measurement is restricted to use in patients receiving insulin treatment and is used to assess endogenous insulin production. Its measurement in patients not on insulin is limited. Measurement of UCPCR can help to distinguish between patients with Maturity Onset Diabetes of the Young (MODY) from patients with Type 1 diabetes. Patients who have Type 1 diabetes have significant insulin deficiency and so have a low UCPCR, whilst levels may be intermediate in patients with MODY and even higher in patients with Type 2 Diabetes. UCPCR may be monitored in patients with Type 1 diabetes to determine the extent to which they are progressing though the honeymoon phase, a temporary period shortly after diabetes diagnosis when the pancreas's remaining beta cells still produce a small amount of insulin. UCPCR measurement can be used to assess the extent of endogenous insulin production in insulin-treated Type 2 diabetes patients and to evaluate the need for insulin therapy.