Determinants of HbA1c in non-diabetic children and adults

PhD ceremony: Ms. H. Jansen,16.15 uur, Doopsgezinde kerk, Oude Boteringestraat 33, Groningen

Dissertation: Determinants of HbA1c in non-diabetic children and adults

Promotor(s): prof. R.P. Stolk

Faculty: Medical Sciences

 

HbA1c has been firmly established as an index of long term glucose concentrations and as a measure of the risk for developing complications in patients with diabetes mellitus. Recently, an international expert committee recommended using HbA1c as indicator for diagnosing diabetes. The aim of this thesis was to investigate determinants of HbA1c in non-diabetic children and adults.

The distribution and determinants of HbA1c in non-diabetic infants aged 8-12 months and non-diabetic children aged 8-9 years was investigated. Furthermore, lifestyle determinants of HbA1c at the age of 12, the effects of growth between the ages of 8 and 12 on change in HbA1c, and the effect of environmental factors, genetic factors and gene-environment interactions on HbA1c in non-diabetic adults were studied. The results indicated that 1) HbA1c is normally distributed in non-diabetic infants and children; 2) known risk factors for type 2 diabetes are not associated with HbA1c in non-diabetic infants and children; 3) HbA1c in non-diabetic children is fairly stable over time; 4) a substantial part of HbA1c is determined by other factors besides glycaemia and erythrocyte lifespan. Based on these findings it was concluded that HbA1c is not suitable for diagnosing diabetes.