Years ago, I had dramatically elevated liver enzymes for a few months. While waiting for answers from the medical professionals, I went looking online for information about hepatitis, and on a hepatitis information board, I met a couple people who had developed type 1 diabetes within a year of being treated for hepatitis C; they said it was a risk of the treatment. As it turns out, the professional literature suggests that but has mostly hesitated to come out and say that the treatment definitely causes T1D.
Chronic hepatitis C infection is associated with an increased incidence of type 2 diabetes, which makes some sense because the liver is involved in so much of glucose regulation.
The only curative treatment for hepatitis C, interferon alpha treatment, is known to trigger autoimmune diabetes.
When I look up interferon and diabetes, however, I get a lot of results that have nothing to do with hep C. Because an interferon, as it turns out, is a signal that cells send out to inform the rest of the body that they have been infected. And interferons are involved in the development of autoimmune disease, because in some autoimmune diseases- including type 1 diabetes- the organ that comes under attack from the immune system sends out interferons. Whether that pre- or post- dates the immune attack is uncertain- but this plays a part in the debate about the possibility that autoimmune diseases don't start out as autoimmune diseases. http://www.ncbi.nlm.nih.gov/pubmed/23966997
Genes for specific forms of interferon increase type 1 diabetes risk- although not enough to be anywhere close to the whole story. http://www.ncbi.nlm.nih.gov/pubmed/24402011