March 20, 2005
Diagnosis and Symptoms, LADA and MODY
Question from Dunellen, New Jersey, USA:
I would like your input on my daughter’s condition. She is currently four years old and on the thin side. Due to a separate condition, she has severe kidney damage on the right, none on the left. Also, because of this condition, I had her urine tested one day, which led to the surprise that she might be diabetic. She was admitted to the hospital with a blood sugar level of 283 mg/dl [15.7 mmol/L] and trace amounts of ketones. Her A1c came back at 5.8 and, after being treated with antibiotics, her sugar level got down around 140 mg/dl [7.8 mmol/L]. She was released and put on a diabetic diet and began self-testing. Her numbers at home tend to be around 110 mg/dl [6.1 mmol/L] fasting, 130 mg/dl [7.2 mmol/L] pre-meal and 150 mg/dl [8.3 mmol/L] post meal.
Three weeks later, her blood work came back with no antibodies present. The endocrinologist then recommended an Oral Glucose Tolerance Test. The fasting number came in at 112 mg/dl [6.2 mmol/L], the one hour number at 215 mg/dl [11.9 mmol/L] and the two hour around 160 mg/dl [8.9 mmol/L]. Blood work was again sent out and, today, I was given the results. Still, there are no anti-bodies present. No anti-islet antibodies either. Her C-peptide number was within normal range, but her insulin level was low. Fasting was 1.7; one hour was 2.7; and two hour was 2.0. Her A1c remained 5.8. Her plasma was 97, which I am told is normal.
There is absolutely no history of any type of diabetes in our family. Her birth weight was 7 pounds, 2 ounces. Her endocrinologist is stumped and will be consulting with her peers. She does want us to get a MODY 3 test for my daughter. She indicates that we may want to start insulin. I have multiple questions. I feel that given her numbers at home and the danger of low blood sugar, insulin is premature. Also, of course, could I still be looking at type 1 or could this be MODY? I just now read about it on the web site and, until now, didn’t realize that this seems to be a completely different form of diabetes. I noted that one was associated with kidney disease, although my daughter’s damage was caused by vesicoureteral reflux which allowed infected urine up into the kidneys. Also, I wondered what my daughter’s white blood cell type was as I read that certain types are at high risk for diabetes. My endocrinologist indicated that we would need type 1 diabetic genetic testing to determine this, but didn’t know who did it. Would this be valuable information to us and if so how do we get it done?
It could be an MODY type or could just be a variant presentation of type 1 diabetes. Antibody tests are helpful if positive, but not so helpful if negative. Unfortunately, they are only positive about 60 to 80% of the time with type 1 diabetes. So, if negative, you do not know if your child is in this category or not. Islet cell and GAD65 antibodies are the usual ones available for testing. Research laboratories can also do special sensitive insulin antibodies, but the commercial insulin antibodies are not so useful either. The genetic tests for the MODY gene are just becoming available and your endocrinologists can seek these out through research facilities (i.e. Dr. Mazjoub at Boston Children’s Hospital; Esoterix; Genzyme, etc.)
Sometimes, testing for thyroid antibodies and transglutaminase (celiac) antibodies, if they are positive, gives an indirect assessment of autoimmune problems and, by inference, suggests a variant of type 1 (autoimmune) diabetes.
The blood glucose values you described are certainly not normal, but exactly when to start insulin is a difficult question. Close blood glucose monitoring will help figure this out especially during any intercurrent viral or other illnesses when the stress of the illness may make her blood glucose levels soar. It sounds like your endocrinologist is doing all the right things and asking all the right questions.