Diabetes mellitus is today one of the world's most prevalent chronic diseases, affecting an estimated 422 million people worldwide in 2014, or as much as 8.5% of the world's adult population.
In essence, diabetes occurs either when the pancreas fails to produce sufficient quantities of insulin - the primary hormone responsible for regulating blood sugar levels - or when the body is unable to effectively use the insulin it produces. The long-term health effects of diabetes can be quite serious, with an estimated 1.5 million deaths directly caused by the disease in 2012, and another 2.2 million deaths attributable to high blood glucose as a side effect of the disease. Many of the deaths in the latter category occur well before the median age of mortality, and the major long-term side effects of the disease, which may include high blood glucose, blindness, kidney failure, stroke, heart attacks, stroke, and poor limb circulation leading to amputation, have significant health impact even when not fatal.
Presently, treatment of diabetes generally depends on the disease variant experienced by the patient. In type 1 diabetes, the insulin-producing cells of the pancreas are inadvertently destroyed by the immune system, and the regular supplementation of insulin by injection is the primary avenue of treatment. Type 2 diabetes differs somewhat in that the initial stages of the disease are characterized by insulin resistance, meaning that greater quantities of insulin are required to keep blood glucose levels under control, resulting in greater load on the insulin-producing cells of the pancreas followed by their eventual failure.
Today, regeneration of functioning beta cell mass from human induced pluripotent stem cells represents the most promising approach for the cure to type 1 diabetes, as the reduction in number of functional, insulin-producing beta cells is the primary cause of the disease. In type 2 diabetes, meanwhile, late-stage patients will also benefit from regeneration of beta-cell mass as a method of increasing insulin production to normal levels. Induced pluripotent stem cell regeneration also offers an advantage over the transplantation of pancreatic tissue from other patients in that new tissue regenerated from patients' own stem cells eliminates the risk of tissue rejection and the need for immunosuppressive therapy and its associated complications.