July 22, 2002
Diagnosis and Symptoms
Question from Louisburg, North Carolina, USA:
We have a very strong family history of type 1 diabetes, and since my eight year old daughter has had three fasting glucose tests above 100 mg/dl [5.6mmol/L], her doctor stated she has borderline diabetic and will need to be followed next year. Is she considered to have borderline diabetes or diabetes?
Answer:
The arbitrary cut-off value for fasting glucose is 126 mg/dl (7 mmol/L) so the actual results matter. However, in circumstances of finding a slightly elevated fasting sugar in a child with no symptoms, I would not blithely make a diagnosis of diabetes but would perform a formal oral glucose tolerance test and check antibody levels in blood. Furthermore, a careful family history is required and also perhaps a check on other family members’ fasting blood glucose because an elevated level can run in families and be a benign problem rather than diabetes (Glucokinase deficiency).
KJR
[Editor’s comment: See Classification and Diagnosis of Diabetes and prediabetes.
SS]