
May 28, 2000
Diagnosis and Symptoms
Question from Jerusalem, Israel:
During a routine blood test, my son’s (age 13 years, weight 79 kg, height 171 cm) sugar level showed 267 about 3 weeks ago. Then he started taking insulin shots. He takes 20 units of 70/30 in the morning and 15 units at night. Blood sugars were within the normal range after few days. So, his insulin was reduced 15 units in the morning and 10 units at night. His blood sugars were still very normal, so his insulin was lowered again. Now he is taking 13 units in the morning and 8 units at nights for the past week and his blood sugars are still normal.
The result of the GAD-II test that was taken just came out at 4.9 on a normal scale of 0-1. The doctor still did not fully diagnose him as type 1 diabetes, and he does not seem to be sure of what he was saying. More tests will be done like ICA and GAD again. However, for now is he Type 1. Can it be something else given the very good test results? How can I be sure? What are the needed tests? Can he stop the insulin shots completely?
Answer:
Clearly your son had diabetes at the onset of this episode and by far the most likely possibility is that he has autoimmune diabetes and that he has passed rather quickly into what is called the honeymoon period when there is a transient restoration of his own ability to make insulin. It may be, of course, that during this period which can last many months that his insulin requirements will become even less than the approximately 0.25U/Kg/day that he needs at the moment. Some years ago, it was a frequent practise to discontinue insulin at this point; but not only did that inappropriately encourage the hope that the diabetes would disappear, but there are now immunological grounds for believing that continuing with small amounts of insulin may prolong this honeymoon period. So you should continue with the injections; but in a dose that meets the approval of your son’s doctor.
I am assuming that the anti GAD test was positive — we use a different kind of scale and only report positive or negative — but if this is confirmed there is then no doubt as to the diagnosis. There are some other remote possibilities; but a repeat positive antibody test would discount all of them. Over 90% of children from a Caucasian background who develop acute insulin dependent diabetes have what is now called Type�1A (autoimmune) diabetes, a diagnosis that has to be confirmed by a positive antibody test. (Some children with this background have a similar clinical onset; but are antibody negative: Type 1B Diabetes as this is called is especially common in certain ethnic groups such as Hispanic and African Americans. I know of no figures for Israel. The importance of making this distinction, which I am sure your son’s doctor has in mind, is that 1B children can often manage without insulin after a few months although it seems that in the long run they will have to depend on it once again.)
Children with autoimmune diabetes, on the other hand, are now committed to subcutaneous insulin for the foreseeable future or at least until techniques have been developed to circumvent the immune response to islet cell transplantation. They are also vulnerable to other linked autoimmune conditions such as hypothyroidism and the celiac syndrome, so that you might want to talk to the doctor again as to whether these possibilities should be screened for.
DOB