Analysis of insulin-producing cells has revealed that those with type 2 diabetes have epigenetic changes in approximately 800 genes, with altered gene expression in over 100 genes (many of them relating to insulin production).
Epigenetic changes occur as a result of factors including environment and lifestyle, and are reversible. A number of these changes were also found in place in healthy subjects as a result of age or high BMI, suggesting these changes could contribute to the development of the disease
http://www.eurekalert.org/pub_releases/2014-03/lu-ecc030714.php