Demonstration of increased concentrations of circulating glycated insulin in human Type 2 diabetes using a novel and specific radioimmunoassay

Diabetologia. 2003 Apr;46(4):475-8. doi: 10.1007/s00125-003-1059-y. Epub 2003 Mar 18.

Abstract

Aims/hypothesis: Glycation of insulin, resulting in impaired bioactivity, has been shown within pancreatic beta cells. We have used a novel and specific radioimmunoassay to detect glycated insulin in plasma of Type 2 diabetic subjects.

Methods: Blood samples were collected from 102 Type 2 diabetic patients in three main categories: those with good glycaemic control with a HbA(1c) less than 7%, moderate glycaemic control (HbA(1c) 7-9%) and poor glycaemic control (HBA(1c) greater than 9%). We used 75 age- and sex-matched non-diabetic subjects as controls. Samples were analysed for HbA(1c), glucose and plasma concentrations of glycated insulin and insulin.

Results: Glycated insulin was readily detected in control and Type 2 diabetic subjects. The mean circulating concentration of glycated insulin in control subjects was 12.6+/-0.9 pmol/l ( n=75). Glycated insulin in the good, moderate and poorly controlled diabetic groups was increased 2.4-fold ( p<0.001, n=44), 2.2-fold ( p<0.001, n=41) and 1.1-fold ( n=17) corresponding to 29.8+/-5.4, 27.3+/-5.7 and 13.5+/-2.9 pmol/l, respectively.

Conclusion/interpretation: Glycated insulin circulates at noticeably increased concentrations in Type 2 diabetic subjects.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Diabetes Mellitus, Type 2 / blood*
  • Female
  • Glycosylation
  • Humans
  • Insulin / blood*
  • Male
  • Middle Aged
  • Radioimmunoassay / methods*
  • Serum Albumin

Substances

  • Insulin
  • Serum Albumin
  • glycosylated serum albumin