
July 18, 2005
Diagnosis and Symptoms
Question from Portland, Oregon, USA:
I am 16 years old and my endocrinologist thinks I might have type 2 diabetes. I have been treated as a type 1 for over three years. I did not have ketones when I was diagnosed and I have never checked since because our ketone strips are old. I take 22 units of Lantus in the morning and seven or eight units of NovoLog before every meal and two units of NovoLog at bedtime.
They tried to put me on oral medication, but it did not work at all and I always felt sick. My blood sugar is always going up and down. It will go from 267 to 187 mg/dl [14.8 to 10.4 mmol/L] with four units (two hours between), then from 187 to 56 mg/dl [10.4 to 3.1 mmol/L] with two units. There is type 2 diabetes in the family, but not too close (great-grandfather on my mother side) but that’s it. Does this look more like type 1 or type 2?
Answer:
It is not always easy to distinguish type 1 from type 2 diabetes. It typically is very easy, but not always. And, there are other factors that can make a person with type 1 have some type 2 features. And some type 2s require insulin! Confusing, isn’t it?
The city that you are writing from has some terrific pediatric and adult endocrinologists, some renowned. So, you should be able to find a good doctor.
You did not indicate your weight, but given the glucose fluctuations you describe and the potential ineffectiveness of oral agents in the past, plus your age at diagnosis, I think it would be more likely that you indeed have type 1 diabetes. The lack of ketones is not so classic of type 1, but then again you indicated that you do not check.
There are blood tests that can help better distinguish this for you and your doctor, although they are not always helpful. These are called “pancreatic antibody” tests. The ones most often tested include those called “GAD-65” and ICA-512 (sometimes also called IA2). Sometimes, we measure antibodies directed towards insulin itself. Your doctor can order these commercially available tests.
If there is an immediate family history of diabetes, a type of diabetes called MODY could be screened for also.
I’d start with your pediatric endocrinologist and these pancreatic antibody tests. Please let us know what you learn.
DS
[Editor’s comment: Be sure to discuss your insulin schedule with your endocrinologist. It sounds like you are taking a second dose of NovoLog two hours after a dose. However, in many people, NovoLog lasts more than two hours, sometimes as many as four. So, you are possibly overlapping the doses and causing lows. Perhaps you should consider waiting three hours, then check your blood sugar and determine if you still need the extra two units. Maybe you need only one unit or none at all. It is also possible that you need to refine your insulin-to-carbohydrate ratio.
BH]