June 7, 2005
A1c (Glycohemoglobin, HgbA1c), Diagnosis and Symptoms
Question from Elkins, West Virginia, USA:
There is something I have been curious about since my five year old daughter’s diagnosis of type 1 diabetes in August of 2004. At diagnosis, her symptoms were increased thirst and urination, blurry vision, and a yeast infection that would not heal. Upon taking her to the doctor, her sugar level was 533 mg/dl [29.6 mmol/L] with no ketones or signs of DKA. To back up a little, she had increased urination and increased thirst since the age of three. I just always associated the increased urination to the increase of fluids.
At diagnosis, my daughter weighed 39.5 pounds. She had lost about three-fourths of a pound in a two week period. She was released from the hospital on two units of lispro and four units of NPH in the morning and one-half a unit of each at dinner time. She increasingly has decreased her insulin dosages to currently one-half a unit of lispro and 1.5 units of NPH in the morning and one-half a unit of each at dinner time. She has had two urinary tract infections since her diagnosis. She was taking Sulfatrim for treatment and her blood sugars remained normal while on this medication. Is it possible that she could have type 2 diabetes since the long duration of symptoms and the low dosages of insulin that she is on and the Sulfatrim drug are maintaining her blood sugar levels? There is a history of type 2 in my family, but no history of type 1. There were no tests run when she was diagnosed. She has seen her endocrinologist twice and he has never run any further testing, no A1c test, nothing. I would just like a second opinion.
It would be very unusual for a young child to have type 2 and not type 1 diabetes, but not impossible. Antibody tests (islet cell, GAD65) would confirm type 1, if positive, but are only positive about 60 to 80% of the time. So, a positive test would confirm the diagnosis while a negative test would not provide much information. Also, over time, such antibody tests often go from positive to negative so this would be a possibility away from the point of diagnosis. Time will answer this question since, over time, it would be expected to see increasing insulin needs and not such low insulin requirements. Because the pancreas is so “deep” in the body, there is no direct and easy way to get a biopsy to prove what is going on in the islet cells themselves.
I don’t understand why no A1c tests are being done. This is usually done at least every three months. In the DCCT (Diabetes Control and Complications Trial), it was done every month as part of intensified management and to give feedback for trends. Also, there should be some periodic monitoring of lipids, kidney functions, thyroid functions/antibodies and celiac screening since all these problems can be subclinical and only show up on laboratory testing.