Diabetes is a complex, serious, and increasingly common disease. It is the most frequent cause of blindness among working-age adults; the leading cause of nontraumatic lower extremity amputation and end stage renal disease; and a principal cause of congenital malformations, perinatal mortality, premature mortality, and disability. Persons with diabetes are at increased risk for stroke, ischemic heart disease, peripheral vascular disease, and neuropathy.