Diabetes mellitus (DM) is a growing health problem in the United States afflicting over 18.2 million Americans. Before developing type 2 DM patients almost always have pre-diabetes. At least 20.1 million people in the United States ages > or =40 to < or =74 years have pre-diabetes. Research has shown that controlling blood glucose can delay or prevent type 2 DM from ever developing. Morbidity and mortality from DM most commonly result from the long-term complications of the disease. Data from several studies suggest that aggressive management of DM and its associated risk factors will lead to a reduction in these long-term complications. The term "intensive therapy" is being used for whatever strategy keeps blood sugar near normal, as well as for aggressive management of other associated risk factors such as lipid abnormalities and blood pressure. Intensive management of glycemia may have long-lasting benefits over conventional therapy. New clinical trials are being carried out to determine whether goals for intensive therapy should be lower than current goals while testing is being carried out on a variety of therapeutic strategies to determine the optimum methods to prevent diabetes complications.