Circulating levels of autoantibodies to oxidized low-density lipoprotein and C-reactive protein levels correlate with endothelial function in resistance arteries in men with coronary heart disease

The association between C-reactive protein (CRP) and future cardiovascular risk has been of particular interest during recent years. Oxidized low-density lipoprotein (ox-LDL) is another marker linking the immune system with the atherogenic process. The aim of this study was to examine whether ox-LDL and CRP were associated with endothelial function in peripheral resistance arteries. Twenty-five men with a previous hospital-diagnosed myocardial infarction were enrolled in the study. The exclusion criterion was a history of diabetes mellitus. IgG and IgM autoantibodies to malonyldialdehyde low-density lipoprotein (MDA-LDL) and high-sensitivity CRP (hs-CRP) were measured. Flow-mediated dilatation was measured in isolated resistance arteries from subcutaneous fat biopsies. Endothelial function test reflecting the maximum vessel dilatation in male subjects was inversely related to MDALDL IgG autoantibody levels (r = -0.6 and P = 0.003). Comparison of hs-CRP levels and of maximum vessel dilatation in males revealed also an inverse relation (r= -0.4 and P = 0.04). In conclusion, a clear correlation exists between flow-mediated dilatation in subcutaneous resistance arteries and plasma levels of MDA-LDL IgG autoantibody and CRP in male patients with coronary heart disease.