Diabetes mellitus and other categories of impaired glucose tolerance are frequent in the adult population and are associated with an increased risk for cardiovascular disease and microvascular complications. The diagnosis of these entities should be performed early and using sensitive and accurate methods, since lifestyle changes and correction of hyperglycemia may delay the incidence of diabetes and its complications. Glucose tolerance test is the reference method and the diagnosis of diabetes and impaired glucose tolerance are established when the 2h plasma glucose after an oral intake of 75g of glucose is > or = 200mg/dl or > or = 140 and <200mg/dl, respectively. When it is not possible to perform this test, fasting plasma glucose levels > or = 126mg/dl or > or = 110 and <126mg/dl, respectively, are used to establish the diagnosis of diabetes and impaired fasting plasma glucose. Glycohemoglobin should not be used for the diagnosis but it is the reference method for evaluation of the long-term glucose control. The etiological classification of diabetes mellitus includes 4 categories: type 1 diabetes, type 2 diabetes, other specific types of diabetes and gestational diabetes. The assignment of the patient in each category usually is made on clinical grounds, however in some case the measurement of C-peptide and autoantibodies are necessary.
Type 1 diabetes; Type 2 diabetes; Diagnostic criteria; Oral glucose tolerance test; Fasting plasma glucose; Glycohemoglobin
