My two sons, ages two and five, have been going through testing for years. The last test results showed a fasting glucose level of 55 mg/dl [3.1 mmol/L], a fasting urine with no glucose or protein present, but 15mg/dl of ketones, and a fasting insulin level test of less than 2. Why are the doctors having a hard time with this?

I am assuming that your two sons have been tested for diabetes because of some special concern based on their family history. A fasting blood glucose of 55 mg/dl [3.1 mmol/L] is low; but within normal limits, and a fasting insulin level of less than 2 means very little unless you know what units the results were expressed in (presumably micro units/ml) and whether the test was done after some days on a high carbohydrate diet, which seems unlikely in view of the ketones and the rather low blood sugar. Perhaps the doctors are puzzled by the presence of ketonuria, so I should add that in small children especially in early morning samples after an overnight fast, ketones are common and are due to the use of body fat for energy when glucose levels are low. I see nothing in this information to suggest any form of diabetes.

DOB