October 29, 2003
Diagnosis and Symptoms
Question from :
I am a 18 year old female (5 feet 2 inches;110 pounds) who was diagnosed with type 1 diabetes while I was on a trip last year. At that time, my blood sugar was 310 mg/dl [17.2 mmol/L], and I had moderate ketones in my urine. I was able do stop taking insulin three months after I was diagnosed and was not having any problems. During this time, I went to a endocrinologist who said I was misdiagnosed as my blood sugar was normal most of the times. They measured my C-peptide which was 2.4, my blood sugar was 87 mg/dl [3.3 mmol/L], and I had negative ICA. Even though I am pretty active and was never overweight, I was told I had prediabetes and could prevent diabetes by exercising and eating heathy.
Two months ago, my new endocrinologist measured my C-peptide again which was 1.2 and my blood sugar was 95 mg/dl [5.3 mmol/L]. In addition, my insulin level was at the low end of the normal range so basically, my insulin level dropped by two-thirds in six months, and my blood sugar started to creep up at that time.
I have a past history of anorexia, so at time my blood sugar started creeping up, I started using my defense (controlling food). The main problem is that I avoid insulin so I do not gain weight, and nowadays I am eating about 400 calories a day with less than 20 grams of carbohydrates. I exercise for an hour every day (running, biking, lifting).
I started to work with a therapist last week, and I know I have to sort those feelings out. When I started with these behaviours, my blood sugar went down and was on target, but nowadays I have hypoglycemia every day when I exercise, and I passed out four times already.
My new endocrinologist told me my insulin production is decreased, but I know that some people with type 2 diabetes have a decreased production of insulin too. I also wonder why would I have hypoglycemia if I do not produce enough insulin, and I am not injecting any either. Could I simply have type 2 diabetes? Is it true that people with anorexia are insulin resistant? How many years do people with type 1 diabetes continue to produce insulin after being diagnosed?
Answer:
Your story is complicated, and there are many subplots. The first issue is what kind of diabetes do you have? It would be unlikely to be type 2 diabetes since you are thin. Your islet cell antibodies are negative for anti-islet antibodies but there are other antibodies that can be measured that may be more helpful as ICA antibodies can revert to negative after diagnosis. It would be helpful doing these.
It is possible to explain your lack of an insulin requirement based on a honeymoon period during which the surviving insulin-producing cells may operate more efficiently after the high glucose is cleared. Type 2 diabetes can be associated with ineffective insulin secretion, but the studies you describe are not sensitive enough to highlight this lack of insulin secretion. The lows may simply be occurring because you are not eating enough. I know this raises previous issues related to your eating disorder, and you need to know that it is not desirable nor healthy to eat 400 calories per day. I hope you can continue to get counseling about this as you need support while you deal with these complicated issues.
JTL
