The cause of diabetes mellitus is metabolic in origin. However, its major clinical manifestations, which result in most of the morbidity and mortality, are a result of its vascular pathology. In fact, the American Heart Association has recently stated that, “from the point of view of cardiovascular medicine, it may be appropriate to say, diabetes is a cardiovascular disease” (1). But diabetic vascular disease is not limited to just the macrovasculature. Diabetes mellitus also affects the microcirculation with devastating results, including nephropathy, neuropathy, and retinopathy. Diabetic nephropathy is the leading cause of end-stage renal disease in the United States, while diabetic retinopathy is the leading cause of new-onset blindness in working-age Americans. The importance of this text on Diabetes and Cardiovascular Disease is evident by the magnitude of the population affected by diabetes mellitus. Over 10 million Americans have been diagnosed with diabetes mellitus, while another 5 million remain undiagnosed. The impact from a public health perspective is huge and increasing. As the population of the United States grows older, more sedentary, and obese, the risk of developing diabetes and its complications will increase. Epidemiological studies have identified diabetes mellitus as a major independent risk factor for cardiovascular disease. Over 65% of patients with diabetes mellitus die from a cardiovascular cause. The prognosis of patients with diabetes mellitus who develop overt clinical cardiovascular disease is much worse than those cardiovascular patients free of diabetes mellitus.