Increased level of advanced oxidation protein products in patients with coronary artery disease

Witko-Sarsat et al. previously reported that advanced oxidation protein products (AOPP), which were determined by measurements of optical density (OD) at 340 nm under acidic conditions, were present at high levels in the plasma of uremic patients. We measured AOPP in the plasma of 392 patients who underwent coronary angiography because of suspected coronary artery disease (CAD) and examined the association between plasma AOPP levels and CAD. We also collected plasma from hemodialysis patients and healthy volunteers for AOPP assay. Plasma fractionation by size-exclusion chromatography was performed to determine the weights of the molecules involved in the AOPP activity. The elution patterns obtained after plasma fractionation by size-exclusion chromatography were the similar in both CAD and hemodialysis patients, but differed from those of the healthy volunteers, whose AOPP levels were low. We also found that, the severity score of CAD obtained by the Gensini scoring system had good correlation with AOPP quartiles. Multivariable regression models revealed that the plasma AOPP level was significantly related to CAD status. This is the first report of an association between AOPP and CAD. AOPP was an independent risk factor for CAD. Oxidative stress is speculated to be associated with the pathogenesis of CAD.