Glycemic control prevents or delays the microvascular complications - retinopathy, nephropathy and neuropathy - and may reduce macrovascular events in both type 1 and type 2 diabetes mellitus (T1DM and T2DM respectively) (1,2). However, because of the imperfections of all current treatment regimens, iatrogenic hypoglycemia is the limiting factor in the glycemic management of diabetes (3). The barrier of hypoglycemia precludes true glycemic control in patients with T1DM and many with T2DM. Thus microvascular complications can occur and macrovascular complications often occur despite aggressive glycemic therapy. Iatrogenic hypoglycemia also often causes recurrent physical and recurrent or persistent psychosocial morbidity, and causes some mortality, in both T1DM and T2DM (3). In addition, episodes of hypoglycemia, even asymptomatic episodes, impair physiological and behavioral defenses against subsequent hypoglycemia by causing hypoglycemia-associated autonomic failure and thus a vicious cycle of recurrent hypoglycemia (3).