Diagnosis of Prediabetes and Diabetes Prevention

Before the onset or diagnosis of overt type 2 diabetes, individuals may have significant “dysglycemia” for years, characterized by plasma glucose levels that do not meet the criteria for diabetes but are higher than those considered normal. Diagnosis of the “prediabetic state” is mandatory because numerous clinical studies have indicated that a substantial number of individuals with this disorder will later develop diabetes and that the condition is associated with an increased risk of chronic complications, in particular cardiovascular events. This chapter provides an overview of the historical definitions of the prediabetic state and the status of current diagnostic criteria of prediabetes on the basis of long-standing glucose criteria; namely, the fasting plasma glucose and/or oral glucose tolerance test and more recently, the HbA1c (glycated hemoglobin) level.