My eight year old son was diagnosed with type 1 diabetes a couple of months ago. His fasting blood sugar when he was hospitalized was 198 mg/dl [11mmol/L], and he had a 2+ level of ketones in his urine. Our endocrinologist said he was definitely type 1 because he had ketones and low insulin (3.3). However, when his lab results came out a month later, we realized his antibodies (including insulin antibodies, islet cell antibodies, and GAD antibodies) were all negative, and his insulin level on admission was again 3.3 and C-peptide, 0.9. My sister, a pediatrician, suggested to get a second opinion on the test results. So we brought these to another endocrinologist, who suspected that my son might be type 2 because of the negative antibodies and the fact that he was a little overweight — he had a fatty liver. He is now taking insulin (NPH and Regular) twice a day and doing okay.

What is your opinion about the lab results? Is it important to find out whether my son is either type 1 or 2? Is there anything we can do at this stage to find that out? If it’s type 2, do we need different treatment for my son?

We all wish that there was a clear test to determine if a child has type�1 or type�2 diabetes. The final diagnosis is based on multiple factors including a detailed history and physical examination in addition to the lab testing that you have provided. Negative antibody tests do not rule out type 1 diabetes. These tests are more helpful in making the diagnosis of type 1 diabetes only when they are positive. I agree that is important to determine if your child has type 1 or 2 diabetes, but this must be done by a pediatrician or pediatric endocrinologist with experience in differentiating the two diagnoses in difficult cases such as with your son.

MSB
Additional comments from Dr. Donough O’Brien:
You should also perhaps ask about type 1B diabetes, where after a time blood sugars may be managed without insulin and with oral hypoglycemics or just diet and exercise.

DOB

[Editor’s comment: The insulin and C-peptide levels you cite are low if they were done at the time as the blood sugar of 198 mg/dl [11.mmol/L]. However, your son may have type�1B in which antibody tests are negative, and many children become insulin independent after a while. He might also have type 2 or Maturity Onset Diabetes of the Young. It really makes little difference as long as he is doing well.

SS]