Arlan L Rosenbloom and Martin Silink
The diagnosis of diabetes mellitus encompasses a wide array of metabolic diseases characterized by chronic hyperglycemia. Because insulin is the only physiologically significant hypoglycemic hormone, hyper-glycemia must be the result of either impaired insulin secretion by the beta cells of the pancreas, resistance to the effect of insulin in the liver, muscle, and fat cells, or a combination of these pathophysiologic situations. It is important to recognize that the hyperglycemia of diabetes is not simply a reflection of abnormal glucose metabolism, but the result of disturbed energy metabolism from inadequate insulin action with widespread disturbances in carbohydrate, fat, and protein metabolism.
Criteria for the diagnosis of diabetes were revised several years ago by the American Diabetes Association (ADA) and the World Health Organization (WHO). 1,2 The major change in the revised criteria for the diagnosis of diabetes has been a lowering of the diagnostic level of fasting plasma glucose from ≥7.8 mmol/l (140 mg%) to ≤7.0 mmol/l (126 mg%).
Also in the revised criteria, categories of impaired fasting glucose (IFG) and impaired glucose tolerance (IGT) were added because of recognition that these abnormalities are associated with increased cardiovascular morbidity, and the ADA has recommended that IFG and IGT be