Prevalence of diabetes in patients with nonacute CAD

The relationship between coronary artery disease (CAD) and diabetes is widely documented [1–3], and diabetic patients present a worse CV outcome in respect to nondiabetic patients [4]. Recently, the physiopathology of CV risk in patients affected by undiagnosed or newly detected diabetes is matter of great interest [5, 6]. Actually, the prevalence of diabetes in CAD patients is not clearly estimated because diagnosis is generally based on not exhaustive criteria, such as history of diabetes or hyperglycemia during acute events. We aimed to evaluate the true prevalence of diabetes in nonacute patients affected by CAD, as assessed by coronary angiography. Six hundred and seventy nine patients admitted from November 2008 to November 2009 in the Cardiology Ward of University of Naples to perform angiography for suspect CAD were assessed for eligibility. Patients with coronary acute events in the last 4 week and subjects without angiographically detectable CAD were excluded. Moreover, treatment with steroids, acute infections, fever, or any condition that could impair glycemic metabolism were further exclusion criteria. Finally, 510 Caucasian patients (301M, 209F; age 57 ± 13 years) were eligible. Ninety seven (19%) had known diabetes (history and/or use of antidiabetic agents or newly discovered by fasting glucose value C126 mg/dl). The other 413 were submitted to standardized oral glucose test tolerance (OGTT), repeated twice in case of abnormal response [7]. Diabetes was revealed in 151 subjects, while 72 were affected by prediabetes, a condition at high risk to develop overt diabetes. Thus, the overall prevalence of diabetes was 48.6%, and the prevalence of glycemic impairments (diabetes plus prediabetes) was 62.7%. Only 190 (37.2%) showed a normal glucose tolerance (Fig. 1). The number of vessels with obstructive plaque (C50% lumen narrowing) was higher in diabetic than in nondiabetic group (1.12 ± 1.13 vs. 1.68 ± 1.33; P \ 0.01),