March 12, 2002
Diagnosis and Symptoms
Question from Norwalk, California, USA:
I am 45 years old, and I was diagnosed with diabetes about a year ago, but I don't understand how I have developed type 1 diabetes at my age. I went in for my annual check up where they always do a full blood workup since I have hypothyroidism. The nurse assumed I had type�2 diabetes (due to age), prescribed various pills, and kept changing the medications every two weeks since I was having different reactions to them. My blood sugar never seemed to stay under 180 mg/dl [10 mmol/L], so finally she sent me to a specialist who was surprised to hear me say I was diagnosed with type 2 diabetes because all my symptoms pointed to type 1. Since my C-peptide and antibody tests were inconclusive, he kept me on Glucophage [metformin] for about two months. However, then my blood sugar rose to over 300 mg/dl [16.7 mmol/L] so he put me on Humalog and Lantus (insulin glargine). I have read that type 1 diabetes is caused by a virus. Is this true? Was it due to a childhood illness as a child and just took years to develop? I had an umbilical hernia at birth, and my appendix almost burst so it was removed when I was 5 years old. Could these be the reason?
No, your hernia and appendicitis were not reasons for you developing diabetes. It sounds like your physician is treating you as if you have type�1 diabetes and that your clinical course is consistent with this diagnosis.
There are other tests which could be done as a test for type 1 diabetes, although they are more academic than anything. People who develop type 1 diabetes after young adulthood have a condition referred to as Late-onset Autoimmune Diabetes of Adulthood (LADA), which is associated with a more gradual loss of beta cell function. Nevertheless, the result is type 1 diabetes. If you are still interested, a review of this subject was published in Diabetes Care in 2001 [below].
[Editor’s comment: See Autoimmune diabetes not requiring insulin at diagnosis (latent autoimmune diabetes of the adult): definition, characterization, and potential prevention, Diabetes Care 2001, 24(8) pp1460-7, and Latent autoimmune diabetes in adults (LADA) and autoimmune thyroiditis, Endocr Regul 2001, 35(3) pp167-72.