Abstract

In 1997 the American Diabetes Association lowered the threshold for diagnosis of diabetes from a fasting plasma glucose concentration of 7.8 mmol/l to 7.0 mmol/l and advised that the oral glucose tolerance test no longer be used in routine clinical practice. In 1999 the World Health Organization endorsed the reduction in fasting plasma glucose threshold but recommended retaining the oral glucose tolerance test for anyone with impaired fasting glucose (6.1 mmol/l–6.9 mmol/l). This Review discusses the impact of these changes on the prevalence of diabetes and examines the implications for individuals and specific high-risk groups. The phenotype of those diagnosed with diabetes and the predictive value for the development of complications according to the different criteria are compared. It is clear that these changes in diagnostic criteria have major importance both for individuals and for resource planning at a national level.