
October 18, 2000
Diagnosis and Symptoms
Question from San Jose, California, USA:
I just had a three-hour glucose tolerance test and would like to know the diagnostic criteria.
Answer:
Nowadays, there is a tendency to use fasting blood glucose levels only for the diagnosis of diabetes. The American Diabetes Association criteria are that fasting levels less than 110 mg/dl [6.1 mmol/L] are normal, between 110 and 125 mg/dl [6.1 and 6.9 mmol/L] is considered impaired glucose tolerance, and over 125 mg/dl [6.9 mmol/L] is overt diabetes. The advantage of the impaired glucose tolerance category is that it gives people whose history may be suggestive of type�2 a chance to see if exercise and weight reduction can lead to an improvement. For people under their mid-twenties, it gives an opportunity to confirm variants of Type�1 diabetes without committing to insulin.
The WHO’s (World Health Organisation) criteria are that fasting levels greater than 140 mg/dl [7.8 mmol/L] are diagnostic and that two-hour levels between 140 and 199 mg/dl [7.8 and 11.0 mmol/L] indicate impaired glucose tolerance, and the values greater than 200 mg/dl [11.1 mmol/L] are, again diagnostic of diabetes.
DOB