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 MDA-LDL 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.