December 1980

Urine C-peptide, β-Cell Function, and Insulin Requirement

Author Affiliations

From the Departments of Pediatrics (Drs Rappaport, Ulstrom, and Fife) and Laboratory Medicine and Pathology (Drs Hedlund and Steffes), University of Minnesota School of Medicine, Minneapolis; and the Department of Pediatrics, St Louis Park Medical Center, St Louis Park, Minn (Dr Etzwiler). Dr Rappaport is now with the Charles A. Dana Research Institute and the Harvard-Thorndike Laboratory of Beth Israel Hospital, Department of Medicine, Beth Israel Hospital and Harvard Medical School, Boston.

Am J Dis Child. 1980;134(12):1129-1133. doi:10.1001/archpedi.1980.02130240013006

• Urinary C-peptide excretion was investigated as a method for monitoring β-cell function in diabetic patients and for studying the contribution of endogenous insulin production to diabetic control. Control subjects had variations in serum and urine C-peptide immunoreactivity that correlated with basal and meal-related insulin secretion. In a group of well-controlled juvenile diabetic patients, those receiving high doses of insulin had low or negligible C-peptide excretion, whereas most patients with low exogenous insulin requirements had near-normal urinary C-peptide excretion. Patients treated for diabetic ketoacidosis had recovery of β-cell function as measured by C-peptide immunoreactivity in serial urine specimens. Thus, measurement of urinary C-peptide excretion is a simple technique that may be useful in assessing endogenous insulin production in juvenile diabetic patients.

(Am J Dis Child 134:1129-1133, 1980)