The term “diabetes mellitus” does not only refer to one disease, but to a group of metabolic diseases characterized by chronic hyperglycemia resulting from defects in insulin secretion, action, or both. The vast majority of cases of diabetes falls into two broad etiopathogenetic categories, type 1 diabetes (T1DM) and type 2 (T2DM), whose pathological processes are respectively the autoimmune destruction of pancreatic β-cells, resulting in insulin deficit, and abnormalities that result in resistance to insulin as well as in an inadequate compensatory insulin secretory response. This article provides a review of the current information about etiopathogenesis (autoimmunity, genetics, environmental factors), epidemiology and therapy.
