January 21, 2007
Diagnosis and Symptoms
Question from Klamath Falls, Oregon, USA:
My 15-year-old daughter was diagnosed with type 1 diabetes about a week ago. With the similar symptoms of type 1 and type 2 diabetes, I am confused as to how it was decided she has type 1. She started with sudden symptoms of extreme thirst and frequent urination about six to eight weeks ago. She also lost about 20 pounds in about the same timeframe. Last week, she had an excruciating headache for four days. When I took her to the doctor, she had sugar and ketones in her urine, a rapid heartbeat, and an elevated blood sugar. That night, she got worse and was subsequently admitted to the ICU. She was extremely acidotic. Subsequently, she was intubated and life-flighted to another hospital that had a pediatric ICU. Her hemoglobin A1c was over 12. She is now being treated with insulin injections. How can we be sure this is really type 1 diabetes and not type 2? She also was diagnosed with hypothyroidism back in October, but her blood sugar, at that time, was in normal range. I just assumed the weight loss she was experiencing was due to her thyroid functioning normally with the institution of Synthroid. She is overweight for height. Wouldn’t that indicate type 2 diabetes instead of type 1?
Answer:
Her age suggests type 1, but her being overweight suggests the possibility of type 2. Her DKA indicates it is more likely type 1. But, there is some overlap as you suggest. Your diabetes team can do special antibody tests, islet cell, GAD and insulin, to see if these are positive. They are not 100% specific, however, and only show up about 60 to 80% of the time, even when there is classical type 1 diabetes. How she does clinically will usually be sufficient to figure this out, so time will help you by observing what type of glucose control is possible. Please go back and ask your diabetes team these questions since they have information that will likely help you figure this out. If she has Hashimoto’s thyroiditis as the cause of her hypothyroidism, then this is another autoimmune disorder that co-exists with type 1 diabetes about 20 to 40% of the time. However, this is also a common endocrine problem and so does not exclude type 2. Celiac is yet another similar autoimmune disorder that should be screened for by your team.
SB
