
April 29, 2001
Diagnosis and Symptoms
Question from Denver, Colorado, USA:
My eight year old son who was diagnosed with type 1 diabetes about four months ago with a fasting blood sugar of 198 mg/dl [11mmol/L], some ketones, but negative antibodies. Since he was diagnosed four months ago, his insulin requirements have been steadily decreased, and now he is almost off of insulin. Our endocrinologist suspects that he is in fact type 2 because of the slow and steady pattern of decrease in insulin requirements as well as negative antibodies. He is a little overweight, but has lost about five pounds.
How do you generally differentiate type 1 in the honeymoon phase from type 2 after some insulin treatment? Do we need to get some tests?
Answer:
I think that it rather more likely that your son has what is now called type 1B or idiopathic diabetes. Like the much more common type 1A (autoimmune) diabetes, it presents with acute insulin dependence, but, in about 50% of cases, the need for insulin slowly diminishes, and glucose levels can be controlled by oral hypoglycemic agents or even by just diet and exercise.
This variant is uncommon in Caucasians, but comprises over 50% of new onset cases in African-American or Hispanic families. From he few studies done so far, it seems that these children do have diminished insulin reserves and that they may well have to go back on insulin in the future. The underlying cause is not yet worked out though some seem to be linked to chromosomal changes.
Type 2 diabetes in children is certainly on the increase, but it usually presents gradually and with a more obvious increase in body weight. In this latter group. serum C-peptide levels are normal to high, whereas in type 1B, they are diminished.
DOB