Oral glucose tolerance test: to be or not to be performed?

Type 2 diabetes is one of the most common diseases worldwide. In addition, there are data for a large cohort of undiagnosed cases. In the RIAD (Risk factors in Impaired glucose tolerance for Atherosclerosis and Diabetes) study a total of 15.1% of so far undiagnosed diabetic subjects were detected as well as 26% of subjects with impaired glucose tolerance in a German risk population for diabetes. Type 2 diabetes is associated with an excessively high mortality and morbidity due to cardiovascular disease. Numerous studies have demonstrated the relevance of postprandial hyperglycemia for atherosclerosis. Moreover, the form of isolated postprandial diabetes seems to be much more common than expected. Even mild postprandial hyperglycemia in the form of impaired glucose tolerance was shown to be associated with an increased rate of cardiovascular disease. This indicates the necessity of using the oral glucose tolerance test (OGTT) in the screening of high-risk populations in order to detect asymptomatic diabetic subjects and enable appropriate treatment in time. Not using the OGTT would mean missing a large cohort of undiagnosed diabetic subjects, particularly among older people. Since an OGTT cannot be generally conducted, we recommend its performance in risk subjects and especially in elderly women. This would make it possible to institute preventive measures.