Objective: The American Diabetes Association (ADA) has revised the criteria for the diagnosis of diabetes in 2010. Glycated haemoglobin at a cut-point of ≥6.5% has been included in the diagnostic algorithm. We aimed to investigate whether there is still the need to perform oral glucose tolerance tests (OGTT).
Methods: We studied 2002 people referred for angiography who did not have a history of diabetes. OGTT were performed in all 1772 subjects with fasting glucose <126 mg/dl. Participants were prospectively followed for all-cause and cardiovascular mortality over a mean duration (±standard deviation) of 7.7 ± 2.0 years.
Results: Using the ADA 2010 criteria 618 individuals were categorised as having new-onset type 2 diabetes. Among these, 167 had isolated post-challenge hyperglycaemia. A total of 346 participants died during follow-up. Cardiovascular death occurred in 202 cases. Those with elevated fasting glucose ≥126 mg/dl and/or glycated haemoglobin ≥6.5% had increased all-cause (hazard ratio [HR]: 1.63, 95% confidence interval [95%CI]: 1.28-2.08, p < 0.001) and cardiovascular mortality (HR: 1.66, 95%CI: 1.21-2.29, p = 0.002) compared to subjects without diabetes according to the ADA 2010 definition. Isolated elevation of post-challenge glucose independently predicted increased cardiovascular mortality (HR: 1.57, 95%CI: 1.02-2.43, p = 0.041). All-cause and cardiovascular mortality were not significantly different between subjects with increased fasting glucose and/or glycated haemoglobin and those with isolated elevation of post-challenge glucose.
Conclusions: Performing OGTT will identify a high risk group for cardiovascular mortality undetected by fasting glucose or glycated haemoglobin.
Copyright © 2012. Published by Elsevier Ireland Ltd.