Type 2 diabetes worldwide according to the new classification and criteria

Two major reports have recently revised the classification of and diagnosti c criteria for diabetes. Classification was previously based on the need fo r insulin (insulin-dependent or non-insulin-dependent), but this has become increasingly confusing. Now the type of diabetes is determined by the etio logical process rather than the treatment modality. Type 1 diabetes is thus characterized by islet cell destruction and type 2 diabetes by a combinati on of defects in insulin secretion and action. An individual with either ty pe of diabetes may be on any treatment modality. This classification should prove to be more logical and, for example, allow latent autoimmune diabete s in adults, which typically does not require insulin at presentation, to b e classified as type 1 diabetes. The fasting plasma glucose diagnostic thre shold for diabetes has been lowered to 7.0 mmol/l (126 mg/dl), and impaired fasting glucose (fasting plasma glucose 6.1-6.9 mmol/l [110-125 mg/dl]) ha s been introduced as a new category of intermediate glucose metabolism. The se changes recognize that the old fasting threshold did not match the 2-h ( postload) threshold well and that both micro- and macrovascular disease dev elop at lower lasting glucose levels than previously recognized. Although t he prevalences of diabetes according to the new fasting and 2-h criteria ar e now similar in most populations, the actual individuals identified as hav ing diabetes are often different. Over 30% of all those with diabetes have a nondiabetic fasting glucose but still have increased cardiovascular morta lity. Thus, it is important to retain the oral glucose tolerance test for t he diagnosis of diabetes.