Objectives: The main hypothesis of the study was that as serum myeloperoxidase (MPO) concentration is known to indicate the progression of the atherosclerotic process, MPO may be associated with common risk factors of atherosclerosis. Therefore, the presence of these risk factors (especially elevated glucose and lipid concentrations) should predict an increased MPO level during the subsequent months. We also hypothesized an association of MPO with markers of other chronic diseases involving inflammation.
Methods: Fifty-three patients with ischemic heart disease were followed for 24 weeks by biweekly visits, during which the basic MPO level was measured (500 measurements in total, 2-12 per patient). The association of the patients' typical MPO with the risk factors of atherosclerosis and other personal determinants was examined by trend analysis and analysis of variance.
Results: MPO was statistically significantly associated with blood leukocyte, neutrophil, and lymphocyte concentrations of the patients (P=0.001-0.003). MPO was also associated with high-sensitivity C-reactive protein (P=0.02). MPO was not associated with markers of lipid and glucose metabolism, of atherosclerosis, or of other chronic diseases.
Conclusion: Contradictory to our hypotheses, the results indicate that the serum MPO level is independent of the commonly measured risk factors of atherosclerosis and markers of other chronic diseases. Consequently, the findings suggest that MPO-related acute pathologic events (such as plaque destabilization) are not associated with the preceding glucose or lipid values. However, the results support the third hypothesis and previously reported view that MPO is a marker of inflammation in patients of ischemic heart disease.