Relationship Between Endothelial Function and Coronary Risk Factors in Patients With Stable Coronary Artery Disease

BACKGROUND: Results of experimental and clinical studies suggest that both coronary artery disease (CAD) itself and its traditional risk factors lead to endothelial dysfunction. The aim of the present study was to determine which CAD risk factors sustain their contribution to endothelial dysfunction despite the presence of established CAD. METHODS AND RESULTS: The study group comprised 150 patients with CAD. Using a high-resolution ultrasound, the diameter of the brachial artery at rest and during reactive hyperemia (flow-mediated dilatation, FMD%: endothelial-dependent stimulus to vasodilatation), as well as after sublingual administration of nitroglycerin (NTG%: endothelium-independent vasodilatation), was measured. The relationship between FMD% and coronary risk factors [diabetes mellitus (DM), total cholesterol, high-density lipoprotein-cholesterol, low-density lipoprotein-cholesterol, triglycerides, age, family history of premature atherosclerosis, smoking, hypertension (HT), body mass index (BMI)] was investigated. In univariate analysis there was an inverse relationship between FMD% and age (r=-0.300, p<0.001), and BMI (r=-0.230, p<0.005) and FMD% was significantly lower in diabetic patients when compared to non-diabetic patients (p<0.001). In stepwise multivariate regression analysis; FMD still correlated with DM and advanced age, but not with BMI (beta=0.065, p<0.001, beta=-0.001 p=0.002, beta=-0.087, p<0.284, respectively). FMD% was found to be not associated with hypercholesterolemia, family history of premature atherosclerosis, HT and smoking. CONCLUSION: Only aging and DM were independently associated with endothelial dysfunction in patients with established CAD.