Key role of postprandial hyperglycemia for the presence and extent of coronary atherosclerosis

Background/Aims: The coronary angiographic state of patients with abnormal glucose tolerance is unclear.

Methods: We enrolled 1040 consecutive patients undergoing coronary angiography for the evaluation of coronary artery disease (CAD). An oral glucose tolerance test was performed in patients without established diabetes.

Results: From our patients, 394 had normal glucose tolerance (NGT), 190 impaired glucose tolerance (IGT), 90 isolated postprandial diabetes (postprandial glucose ≥200mg/dl), and 366 type 2 diabetes previously established or newly diagnosed on the basis of fasting glucose (conventional diabetes). Angiographically detectable CAD was more frequent in patients with IGT, isolated postprandial diabetes, or conventional diabetes when compared to NGT subjects (87.9%, 95.6%, 89.1% vs. 80.7%; p=0.030, 0.001, 0.043, respectively). The prevalence of significant coronary stenoses ≥50%, compared to NGT subjects (57.4%), was similar in IGT patients (59.5%; p=0.628), but significantly higher in patients with isolated postprandial diabetes (77.8%; p=0.001) or conventional diabetes (68.0%; p=0.002). Also the number of significant stenoses compared to NGT subjects was similar in IGT patients, but significantly higher in those with isolated postprandial or conventional diabetes. As a continuous variable postprandial glucose proved independently associated with CAD (standardized adjusted odds ratio (OR) 1.624 [95% CI 1.163–2.269]; p=0.004) and with significant stenoses (OR 1.345 [1.061–1.704]; p=0.014).

Conclusions: Postprandial hyperglycemia is strongly and independently associated with angiographically characterized CAD. In IGT, non-significant CAD is more frequent than in NGT; the prevalence and number of significant stenoses increases when postprandial diabetes evolves.