Poor reproducibility of the oral glucose tolerance test in the diagnosis of diabetes during percutaneous coronary intervention.

Background: Early de novo diagnosis of diabetes mellitus in patients admitted with acute coronary syndromes who have undergone percutaneous coronary revascularization may have prognostic implications. The ideal diagnostic method and its time of performance are unknown due to the uncertain reproducibility of the oral glucose tolerance test (OGTT).

Methods: We assessed 88 patients with no known diabetes mellitus admitted with an acute coronary syndrome who underwent successful percutaneous revascularization. The patients received an OGTT the day after coronary revascularization (7.7+/-6 days after admittance in hospital) and 1 month later.

Results: The mean age of the patients was 60.8+/-10.3 years and 82% were men. The most common reason for admission was acute coronary syndrome without ST elevation (42%), followed by acute coronary syndrome with ST elevation (36%) and stable angina (21%). After the first OGTT, 66 patients (75%) were found to have carbohydrate metabolism disorders (41% glucose intolerance and 34% diabetes mellitus). After the second OGTT 39 patients (44.3%) had carbohydrate metabolism disorders (26% glucose intolerance and 18% diabetes mellitus). The correlation between both tests was low (weighted kappa, 0.23+/-0.1; 0.03-0.43) (p=0.02).

Conclusions: The correlation of the OGTT done in patients admitted with acute coronary syndromes who underwent percutaneous coronary revascularization the day after admittance and the OGTT 1 month later was poor. The prevalence of carbohydrate intolerance in these patients was high.