Hello,
it is related, but not caused by.
People who have one type of autoimmune condition are much more likely to develop another. Both thyroid and diabetes have autoimmune connection so they are often seen together.
Also as we get older we are more prone to diabetes, and if we are heavier we may also be more prone (I don't know if that applies to you).
However, proper medication and thyroid levels are critical to optimising your management of diabetes. So please make sure your levels are optimal (testing FT3 and FT4, which should both be at least mid range or higher, and not just relying on TSH).
I had my thyroid out in Feb of this year I just had more blood work done and Dr says I have diabetes. I have never had an issue with this before. I kind of have to believe its related to losing my thyroid!
I had a TT almost 17yrs ago & did not develope any type of diabetes.