Background: Atherosclerosis and CAD involve lipid deposit, endothelial dysfunction and inflammation. Hypercholesterolemia may cause endothelial dysfunction and inflammation, but few studies have investigated possible anti-inflammatory and endothelial protective mechanisms in high-risk individuals without CAD.
Objective: To study endothelial and inflammatory mechanisms in individuals with different lipoprotein profiles relative to verified coronary artery disease (CAD).
Methods: Statin naive individuals referred to coronary angiography were consecutively included in the study if serum LDL was <2.7 or >4.5 mmol/L. The patients were categorized according to angiographically verified CAD: 1.high LDL with CAD( n=16); 2. high LDL without CAD( n=16); 3. low LDL with CAD( n=15), 4. low LDL without CAD (n=18).
Results: Patients with hypercholesterolemia and verified normal coronary arteries had preserved endothelial function, as assessed by the microcirculatory response to acetylcholine, reduced levels of inflammatory markers and in particular high levels of the anti inflammatory cytokine interleukin-10 (IL-10). On the other hand, patients with CAD, regardless of cholesterol levels, were characterized by endothelial dysfunction as well as enhanced levels of markers of inflammation (i.e. tumor necrosis factor and high-sensitivity C-reactive protein) and platelet activation (i.e. soluble CD40 ligand and soluble P-selectin).
Conclusion: We show that individuals with hypercholesterolemia and verified normal coronary arteries are characterized by raised plasma levels of the anti inflammatory cytokine IL-10, accompanied by preserved endothelial function and a lower degree of platelet activation and inflammation, possibly reflecting a protective anti-inflammatory phenotype in these high-risk individuals.