Preferred Sample Type
Specimen Transport
Samples should be posted on the same day of collection using first class postSample Preparation
None requiredTurnaround Time
5 daysSample Stability
3 days at room temperatureC-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).
UCPCR is mainly to be used in patients on insulin treatment to assess endogenous insulin secretion. Its role in patients not on insulin treatment is limited. The principal role of urinary C-peptide is to identify insulin insufficiency, a feature of long term Type 1 diabetes, in insulin treated patients. Greater than 95% Type 1 diabetes (> 5 year duration) have a UCPCR value < 0.2 nmol/mmol.
Patient Preparation
Sample Collection: 2 hours after eating largest meal of the day, having emptied their bladder before eating (download instruction sheet).
Sample Type: Urine collected in boric acid container.
Notes
Please download and complete the UCPCR Requestor form.
Reference Range
Provided by referral laboratory
UCPCR <0.2 nmol/mmol: Severe insulin deficiency
UCPCR 0.2 -0.6 nmol/mmol: Intermediate insulin secretion
UCPCR >0.6 nmol/mmol: Substantial endogenous insulin secretion
