Diabetes is one of the major causes of early illness and death worldwide. Type 2 diabetes affects approximately 8 percent of the United States population, with as many as 25 to 40 percent of those with diabetes undiagnosed [1,2]. Worldwide, the prevalence of type 2 diabetes is estimated at 6.4 percent in adults, varying from 3.8 to 10.2 percent by region; rates of undetected diabetes may be as high as 50 percent in some areas [3,4].
Type 2 diabetes accounts for over 90 percent of patients with diabetes. Because of the associated microvascular and macrovascular disease, diabetes accounts for almost 14 percent of United States health care expenditures, at least one-half of which are related to complications such as myocardial infarction, stroke, end-stage renal disease, retinopathy, and foot ulcers [5]. Numerous other factors also contribute to the impact of diabetes on quality of life and economics. Diabetes is associated with a high prevalence of affective illness [6] and adversely impacts employment, absenteeism, and work productivity [7].
This topic will discuss the evidence and recommendations related to screening asymptomatic patients for type 2 diabetes mellitus. Screening pregnant women for gestational diabetes and the evaluation of patients with signs and symptoms of diabetes (polydipsia, polyuria, blurred vision, paresthesias, or unexplained weight loss) is discussed separately. Additionally, the prevention of type 2 diabetes in patients with impaired glucose tolerance (IGT) is discussed separately.