Abnormal proinsulin/C-peptide ratio in juvenile diabetes

Acta Diabetol Lat. Oct-Dec 1982;19(4):351-8. doi: 10.1007/BF02629258.

Abstract

B-cell function was studied in 20 diabetic children, with an age at onset of diabetes between 1.16 years (8.8 +/- 4.0). Serum samples were taken before the first insulin injection and after 1, 3, 6, 9 and in a few patients after 18 months. At 3, 9, and 18 months the patients were also given a standardized breakfast load. Serum proinsulin, C-peptide, IRI and insulin antibodies (IgG) were determined. At onset 19 patients had measurable C-peptide (0.22 +/- 0.17 pmol/ml; range 0.05-0.58). Proinsulin varied between 0.000-0.25 pmol/ml (0.069 +/- 0.071) and at onset amounted to 31.3 +/- 29.4 (0.100)% of C-peptide as compared to 3.3 +/- 1.1 (1.7-6.6) in non-diabetics. A long partial remission was significantly correlated to a low proinsulin/C-peptide ratio at onset. In patients with low fasting proinsulin and no insulin antibodies, breakfast stimulation was accompanied by an increased proinsulin release at 3 and 9 months. The results suggest that abnormal proinsulin secretion is a feature of the 'B-cell exhaustion' complex in juvenile-onset diabetes.

Publication types

  • Comparative Study
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Adolescent
  • C-Peptide / blood*
  • Child
  • Child, Preschool
  • Diabetes Mellitus, Type 1 / blood*
  • Diabetes Mellitus, Type 1 / drug therapy
  • Eating
  • Female
  • Follow-Up Studies
  • Humans
  • Infant
  • Insulin / blood
  • Insulin / therapeutic use
  • Insulin Antibodies
  • Male
  • Peptides / blood*
  • Proinsulin / blood*

Substances

  • C-Peptide
  • Insulin
  • Insulin Antibodies
  • Peptides
  • Proinsulin