May 4, 2001
Diagnosis and Symptoms
Question from New Jersey, USA:
Ten months ago, my 11 year old son was diagnosed with type�1 diabetes after exhibiting intermittent periods of excessive thirst and urination. He was admitted to the hospital with a non-fasting blood glucose of 420 mg/dl [23.3 mmol/L], negative urine ketones, and I just recently found out that no antibody test was administered.
When he was released from the hospital he was on 4 units of Humalog with 8 units of NPH in the morning and 2 units of Humalog with 3 units of NPH in the evening. He is currently on 3 units of Humalog with 7 units of NPH in the morning, and 1-2 units of Humalog with 3 units of NPH in the evening. His blood sugar is rarely over 200 mg/dl [11.1 mmol/L], and his hemoglobin A1c results have been 6.4% and 6.9%. He weighs 100 pounds and is about 4 feet 11 inches tall. He has always been on the husky side and had a rather prominent roll of flesh around his middle. He does not have the brown patches on his neck, but he does have several white patches (blotches which seem to have no pigment). He is very athletic and plays sports year round including surfing every day during the summer. In spite of this, he always remained husky. He has recently started to get taller and is thinning out somewhat. His endocrinologist says he is halfway though puberty. Do you think it is possible that he has type 2 and not type 1? Does puberty pose the same insulin resistance for people with type 2 as it does type 1? Lately, on his current amount of insulin we are having many lows with very few readings over 100 mg/dl [5.6 mmol/L].
Answer:
I think that the most likely diagnosis in your son’s case is that he does indeed have type�1A (autoimmune) diabetes. It is the cause of all but 5% of acute insulin dependent new onset cases in Caucasian families. Since he is still probably making some of his own insulin, it is possible that an antibody test even now could confirm this. A negative test would not exclude it, but it might leave open the possibility that he has type�1B or idiopathic diabetes. This occurs in just over 50% of initially insulin dependent cases in Hispanic and African American families in the U.S. and is characterised by a negative antibody test and by the fact that about 50% of cases can, after some weeks or months, gradually keep in good control without the need for insulin at least for a time.
As for type�2 diabetes, his BMI (Body Mass Index) is only 20.2 and thus comfortably in the normal range for boys of his age, and the obviously acute onset would be unusual. If you wanted to be sure of this, you might talk to his doctor about the possibility of measuring C-peptide in the serum either fasting or at three minutes after a standardised intravenous dose of glucose. A normal or high level would favour type2.
DOB
