Chapter 2 Classification , Diagnostic Criteria , and Screening for Diabetes

Diabetes mellitus comprises a heterogeneous group of disorders characterized by high blood glucose levels. Four major types of diabetes have been defined by the National Diabetes Data Group (NDDG) and the World Health Organization (WHO): insulin-dependent diabetes mellitus (IDDM), non-insulin-dependent diabetes mellitus (NIDDM), gestational diabetes mellitus (GDM), and diabetes secondary to other conditions. Diabetes can be diagnosed by the presence of the classic signs and symptoms of diabetes and unequivocally elevated blood glucose levels, by fasting plasma glucose (FPG) ≥140 mg/dl, or by venous plasma glucose ≥200 mg/dl at 2 hours after a 75-g oral glucose challenge.