October 24, 2003
Diagnosis and Symptoms
Question from Wilmington, Massachusetts, USA:
At first, my endocrinologist thought I had type 2 diabetes, but then changed the diagnosis to type 1. My hemoglobin A1c at that time was 8.2-9.1%, and my fasting glucoses were 200 mg/dl [11.1 mmol/L]. I was started on Avandia [rosiglitazone]) and Glucotrol [glipizide] which did not lower my blood sugars, and I wasn’t the typical person who has type 2.
I was 41 years old and thin (5 feet 6 inches; 133 pounds) so he thought I would need insulin. My non-fasting C-peptide was 1.9 ng/ml (not fasting) and 1.8-11.4 ng/ml stimulated (normal fasting: 1.2-4.8 ng/ml). My fasting insulin level was less than 2.0 uU/mL (normal: less than 22.7 uU/mL). I also had a negative GAD antibody level. Prior to starting insulin, my after-meal blood sugar would range 180-370 mg/dl [10-20.1 mmol/L] depending on what I ate.
I have been on Lantus with NovoLog, which has brought my A1c down to 6.3% over the past year. I believe my high glucose readings may have started when I was 40 for at that time I had a random glucose which came back slightly elevated but fasting was on the upper end of normal. At the time of diagnosis I did lose a lot of weight quite quickly and was very thirsty. Since being on the insulin I have gained back my lost weight plus some.
I am still confused as to what type of diabetes I have since I did have negative GAD. I require a very small dose of insulin which hasn’t changed since my diagnosis. I was told that can take sometimes years to change. Is that true? Is it possible my high glucose readings are caused by something other than diabetes? Which type am I?
I am also at this time losing a lot of hair. Is this related to diabetes? I had a thyroid test done which came back negative and my endocrinologist suggested it could be stress which I do not feel I have at this time. Could you help me to understand this a bit more?
Answer:
I understand your confusion regarding this subject. I feel your description is clear enough for me to offer an opinion. By now, you are aware that the schema for characterizing the type of diabetes a person has is not highly specific. It is made on a variety of clinical and laboratory criteria. At the very heart of the diagnosis of type 1 diabetes is whether the islet cells are destroyed enough to significantly decrease the amount of insulin necessary to keep glucose levels normal. In your case, I agree that you probably have Latent Autoimmune Diabetes in Adults (LADA) characterized by thin habitus, low insulin and C-peptide levels, and a poor response to oral agents. The negative anti-GAD antibody is not necessarily confusing. It is helpful when the test is positive but does not exclude the diagnosis if it is negative.
The hair loss is not necessarily part of the diabetes but is a common feature, even in people without diabetes.
JTL
