Differences in rates of glycation (glycation index) may significantly affect individual HbA1c results in type 1 diabetes

Ann Clin Biochem. 1999 Jul;36 ( Pt 4):451-9. doi: 10.1177/000456329903600408.


Ten type 1 diabetic patients recorded their daily home blood glucose values, pre- and post-prandially, for 12 weeks. Blood was collected weekly for HbA1c and total haemoglobin measurement. A rolling 28-day mean of all blood glucose values and a glycation index (the ratio of the HbA1c to the rolling mean blood glucose) were calculated. In the pooled patients' data, there was a large scatter of results about the HbA1c versus mean blood glucose regression line. There was less variation in the results of individual patients. The glycation indices showed marked inter-individual variation, and in 60% of patients there was an inverse relationship between glycation index and mean blood glucose, suggesting a non-linear relationship between mean blood glucose and HbA1c. Patients should be monitored on the basis of their own previous results, and in some patients blood HbA1c may be a less sensitive index of mean blood glucose concentration at higher glucose levels.

MeSH terms

  • Adult
  • Blood Glucose / metabolism*
  • Diabetes Mellitus, Type 1 / blood*
  • Female
  • Glycated Hemoglobin A / metabolism*
  • Humans
  • Male
  • Middle Aged
  • Reproducibility of Results


  • Blood Glucose
  • Glycated Hemoglobin A