Postchallenge hyperglycemia is closely related with early vascular damage in overweight and obese patients.

Objective: There is ongoing discussion on how best to screen for diabetes mellitus. Previous studies suggest that an abnormal oral glucose tolerance test (OGTT) is better than fasting glucose levels in predicting cardiovascular mortality, which is largely determined by macrovascular complications in type 2 diabetes. We examined the relationship between screening methods for diabetes and indices of vascular damage in young individuals at high risk of type 2 diabetes.

Methods: Overweight and obese individuals (n = 76, average age 38 ± 6 years) were screened for diabetes by measuring fasting glucose levels, HbA1c and by performing the OGTT. Indices of early vascular damage, including the central augmentation index (cAIx) and pulse pressure amplification (PPA), were assessed by pulse wave analysis (Sphygmocor). Linear regression analyses were performed to identify independent predictors of vascular damage.

Results: Central SBP and DBP (BPs) were best predicted by age and by peripheral BP levels. cAIx was independently predicted by age (r = +0.324, P = 0.008), DBP (r = +0.294, P = 0.011) and 2-h glucose values of the OGTT (r = +0.390, P = 0.001). PPA was independently predicted by age (r = -0.445, P < 0.001) and 2-h glucose value of the OGTT (r = -0.353, P = 0.003).

Conclusions: The 2-h value of the OGTT was superior to fasting glucose levels and HbA1c in predicting cAIx and PPA in young individuals at high risk of type 2 diabetes. Cardiovascular mortality is largely determined by macrovascular complications in type 2 diabetes, and these data suggest that diabetes screening by OGTT may help to identify those individuals with the greatest risk of future vascular complications.