**Abstract**

As we attempt to understand and treat diseases, the field of epigenetics is receiving increased attention. For example, epigenetic changes may contribute to the etiology of diabetes. Herein, we review the histology of the pancreas, sugar metabolism and insulin signaling, the different types of diabetes, and the potential role of epigenetic changes, such as DNA methylation, in diabetes etiology. These epigenetic changes occur at differentially-methylated sites or regions and have been previously linked to metabolic diseases such as obesity. In particular, changes in DNA methylation in cells of the pancreatic islets of Langerhans may be linked to type 2 diabetes (T2D), which in turn is related to peripheral insulin resistance that may increase the severity of the disease. The hypothesis is that changes in the epigenome may provide an underlying molecular mechanism for the cause and deleterious metabolic health outcomes associated with severe obesity or T2D. Conversely, reversing such epigenetic changes may help improve metabolic health after therapeutic interventions.

**Keywords:** glucose, pancreas, beta cells, epigenetics, DNA methylation, diabetes mellitus, hypomethylation, hypermethylation, histone modification
