Type 2 Diabetes Mellitus: Update on Diagnosis, Pathophysiology, and Treatment

S million individuals in the United States with type 2 diabetes mellitus and an additional 30–40 million with impaired glucose tolerance result in health care costs exceeding 100 billion dollars annually (1). Treatment is predominantly directed at microvascular and macrovascular complications (2). In type 1 diabetes mellitus the relationship between glycemic control and microvascular complications has been well established (3). The relationship between tight glycemic control and microvascular disease in type 2 diabetes mellitus appears to be established in the recently completed United Kingdom prospective diabetes study (4, 5). Despite the morbidity and mortality associated with retinopathy, nephropathy, and neuropathy, cardiovascular disease remains the leading cause of death in type 2 diabetes mellitus (6, 7). Consequently, the treatment of confounding risk factors of obesity, hypertension, and hyperlipidemia assumes major importance and must be coordinated with good glycemic control for reduction in total mortality in type 2 diabetes mellitus (6–11). Based on the emerging relationship between the degree of glycemic control and microvascular complications as well as the contribution of hyperglycemia in the development of macrovascular disease, it is the purpose of this review to summarize the current state of knowledge to provide a rational basis for the treatment of type 2 diabetes mellitus.