"2. Causes of Diabetes Mellitus
Diabetes is caused by resistance to, or deficient production of, the hormone insulin, which helps glucose move from the blood into the cells.
In type 1 immune mediated diabetes, pancreatic beta cell destruction results in failure to release insulin and ineffective transport of glucose. There is no known cause for idiopathic diabetes.
In type 2 diabetes, the beta cells release insulin but, receptors are insulin resistant and glucose transport is variable and inefficient. Some people may have conditions that can cause diabetes, such as Cushing's syndrome, pancreatitis or liver disease."