Assessment of Asymptomatic Coronary Artery Disease in Apparently Uncomplicated Type 2 Diabetic Patients

Assessment of Asymptomatic Coronary Artery Disease in Apparently Uncomplicated Type 2 Diabetic Patients A role for lipoprotein(a) and apolipoprotein(a) polymorphism Carmine Gazzaruso , MD 1 , Adriana Garzaniti , MD 2 , Stefano Giordanetti , MD 1 , Colomba Falcone , MD 3 , Emanuela De Amici , MD 1 , Diego Geroldi , MD, SCD 4 and Pietro Fratino , MD 1 1 Internal Medicine Unit, Diabetes Center, IRCCS Maugeri Foundation Hospital, Department of Internal Medicine and Medical Therapeutics, University of Pavia, Pavia, Italy 2 Diabetes Center, A.O. Province of Pavia, Pavia, Italy 3 Cardiology Unit, IRCCS Policlinico San Matteo, University of Pavia, Pavia, Italy 4 Internal Medicine, Vascular and Metabolic Diseases, IRCCS Policlinico San Matteo, University of Pavia, Pavia, Italy Abstract OBJECTIVE —In patients with uncomplicated diabetes, there is low probability of finding significant coronary artery disease (CAD) by noninvasive tests. Therefore, screening for its presence is not justified, and it is important to find reliable predictors of silent CAD to identify patients with uncomplicated diabetes for further screening. The relationship between lipoprotein(a) [Lp(a)], apolipoprotein(a) [apo(a)] polymorphism, and silent CAD has never been studied. We investigated the association of Lp(a) and apo(a) polymorphism with angiographically documented asymptomatic CAD in type 2 diabetic patients without evident complications. RESEARCH DESIGN AND METHODS —A total of 1,323 diabetic patients without any clinical and electrocardiographic evidence of CAD were evaluated. Of 121 patients with highly positive results of exercise electrocardiography (ECG) ( n = 30) or positive results on exercise thallium scintigraphy ( n = 91), 103 subjects showed angiographically documented CAD (CAD group). Of 1,106 patients with negative results on exercise ECG, 103 subjects without CAD (NO CAD group) were selected and matched by age, gender, and duration of diabetes to patients in the CAD group. In patients in the NO CAD group, results of exercise ECG, 48-h ambulatory ECG, and stress echocardiography were negative for CAD. RESULTS —The CAD group had higher Lp(a) levels (21.7 ± 17.7 vs. 15.2 ± 19.0 mg/dl; P = 0.0093) than the NO CAD group, and a percentage of subjects had at least one small apo(a) isoform (68.9 vs. 29.1%; P = 0.0000) higher than the NO CAD group. Logistic regression analysis showed that apo(a) phenotypes (odds ratio [OR] 8.13, 95% CI 3.65–21.23), microalbuminuria (5.38, 2.44–11.