The added value of oral glucose tolerance testing in pre-diabetes

With the increased acceptance of glycated hemoglobin measurement as the test of choice for the diagnosis and detection of diabetes, doubts which surround the use of the oral glucose tolerance test (OGTT) in detecting disturbances in glucose levels have become even more apparent. Metabolically, there are still arguments to use the OGTT. Epidemiological studies though, have not always supported the efficacy of the OGTT when used for screening in obese patients. In our opinion, current evidence suggests an additive value of the OGTT, its main advantage being the ability to detect stages of pre-diabetes more accurately than HbA1c and the ability to investigate postprandial glucose levels in a physiological way.