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?
Answer:
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].
JTL
[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.
SS]
