My 16 year old son was diagnosed with diabetes on August 4, 2004. His was not an emergency case. He was feeling tired so we took him to the doctor. He was first diagnosed as a probable early onset type 1. He is not overweight. He has run cross country and track for six years, and is very active. There is not a single case of diabetes in his direct ancestors for at least four generations. Four generations is as far back as we know. His mother, and myself, are both age 46, and in excellent health. My son has no signs of insulin resistance.

At diagnosis, my son’s fasting blood sugar was 166 mg/dl [9.2 mmol/L]. Two hours after a breakfast of 30 grams of carbohydrates, his blood sugar was 419 mg/dl [23.3 mmol/L]. He was given seven units of Lantus, at the diabetic center, and three units of NovoLog after supper, the first day. The next morning, his sugar was below 20 mg/dl [1.1 mmol/L]. We gave him glucose tablets to bring it up. He has not had insulin since the first day, and his sugar levels have returned to near normal for the last four weeks. Most readings are between 80 mg/dl [4.4 mmol/L] and 120 mg/dl [6.7 mmol/L]. He has had one 193 mg/dl [10.7 mmol/L] and one 167 mg/dl [9.3 mmol/L] reading when tested two hours after eating. All other blood sugars, including after meal readings, have been below 120 mg/dl [6.7 mmol/L]. He eats about 200 grams of carbohydrates day. His antibodies tests, for type 1, came back negative. We are now being told it could be type 2 or very early onset type 1. What is the most likely, type 1 or 2?

This is an odd story that you relate. It could be early type 1. It is unlikely to be type 2, if he is not obese, and, if he has no other signs of classical insulin resistance (acanthosis nigricans, for instance). Islet cell and GAD65 antibodies, if positive, would suggest this is an early stage of type 1 autoimmune diabetes. However, about 20 to 40 percent of type 1 cases will have negative antibodies, so the antibodies will only help figure out a diabetes if they are positive, not negative. Most kids do not have other family relatives with diabetes so that this is not so unusual in your case.

I would continue to monitor his blood sugar closely. Avoiding concentrated carbohydrates and staying in close contact with your diabetes team would all be reasonable. Unfortunately, time will be the best way to figure out what to do, when to restart insulin, if the blood glucose levels rise, etc. Doing some blood glucose checks 30 to 60 minutes after food would also give you some information about insulin needs since this would be the most difficult time, even if some insulin remains available at the moment.

SB
Additional comments from Dr. David Schwartz:

You did not describe any specific symptoms that led to the diabetes diagnosis. But, given the lab results you have relayed, fasting glucose more than 125 mg/dL [6.9 mmol/L], after meal glucose levels well over 200 mg/dL [11.1 mmol/L], and an elevated A1c value, I am sure that he has diabetes mellitus. Given that he is not overweight and active and given that he has been obviously very responsive to insulin, this does not at all sound like a classical case of insulin resistance. Despite the negative pancreatic antibodies, this is probably type 1 diabetes. Given the family history of lupus and ulcerative colitis, this only adds to the suspicions.

There are several common pancreatic antibodies that can be tested for. Frankly, not all laboratories do these tests well so negative antibodies may hinge more on the laboratory. Did your physician screen for GAD 65, ICA 512 (also called IA2 or tyrosine kinase), and insulin autoantibodies? Even if all three of these antibodies were negative, I would still be suspcious of type 1 diabetes. I will add that negative ketones at presentation is a bit odd. That’s why it would be interesting to know what led to the diagnosis.

There is a subset of type 1 diabetes that is indeed antibody negative. This has been classified as “type 1 b” diabetes. See Type 1 Diabetes for a definition.

The fact that “tests showed he was producing insulin” may be meaningless in the first phases of type 1 diabetes. The degree of insulin production, relative to the simultaneously measured glucose might shed some light.

That your son is so active is such a wonderful plus and likely plays a great role in his glucose control.

NO insulin requirement in several months is unusual, to say the least, in a teen with type 1 diabetes. He could have an exceptional diabetes honeymoon spurred on by his great physical activity.

If your teenage son has not been seen by a pediatric endocrinologist, you might request a referral for better testing of other possibilities.

DS