Strategies to prevent type 2 diabetes.

Type 2 diabetes mellitus is a public health problem of epidemic proportions and its prevalence is on the rise. The typical American born today has a one in three chance of developing type 2 diabetes. This diagnosis is associated with an adverse cardiovascular prognosis and is considered the risk equivalent of established coronary disease. Many risk factors, including the metabolic syndrome, have been implicated in its development. Even in high-risk individuals, type 2 diabetes is a preventable disease. Diet and exercise have been consistently shown to decrease the incidence of diabetes in large randomized controlled studies. Additionally, new-onset diabetes was reduced by several oral pharmacologic anti-diabetic agents including metformin, acarbose and troglitazone in randomized trials which studied patients with impaired glucose tolerance. More interestingly, multiple large prospective studies have also reported a reduction in the development of type 2 diabetes in patients treated with anti-hypertensive agents, predominantly angiotensin converting enzyme inhibitors and angiotensin receptor blockers. In this review, we will discuss some of these important trials and the speculative mechanisms whereby those medications prevent type 2 diabetes. Such observations, if proven to be true, may represent preventive strategies which can be considered in patients with pre-diabetic conditions such as the metabolic syndrome, hypertension, impaired fasting glucose, family history of diabetes, obesity, congestive heart failure or other risks for the development of type 2 diabetes.