C-peptide in diabetic children after stimulation with clucagon compared with fasting C-peptide levels in non-diabetic children.

Fasting serum C-peptide and total immunoreactive insulin (IRI) were determined in 38 non-diabetic children and adolescents 6-22 years old. C-peptide varied between 0.22-0.73 pmol/ml (mean +/- SD, 0.45 +/- 0.11). There was a tendency to higher values during puberty. No difference was found between subjects with or without a family history for diabetes. IRI varied between 0-31 millimcron/m1 (mean +/- SD, 11.3 +/- 6.5). The C-peptide response to glucagon was studied in 10 insulin dependent juvenile diabetics 11-19 years old, who had had measurable amounts of fasting C-peptide on some occasions during the previous years. Duration of diabetes varied between 4-12 years. A slight but significant rise in C-peptide level occurred in 3 patients. Their metabolic control estimated on the basis of daily urinalysis was "excellent" or "good". The results support the hypothesis that even trace remnants of the beta cell function may be of importance for the metabolic control in juvenile diabetes.