Association between human paraoxonase 1 activity and intima-media thickness in subjects under 55 years of age with carotid artery disease

Background: Human serum paraoxonase (PON1) protects lipoproteins against oxidation by hydrolyzing lipid peroxides in oxidized low-density lipoprotein (oxLDL); therefore, it may protect against atherosclerosis. PON1 activity and polymorphisms have been inconsistently associated with carotid artery disease. The goal of this study was to clarify the role of PON1 activity and phenotype on carotid artery disease and its correlation with some inflammatory and immune markers in subjects under 55 years with early-onset carotid atherosclerosis. Methods: Sixty patients with occlusive carotid artery disease and 30 healthy controls were enrolled. Intimamedia thickness (IMT) was measured by high-resolution ultrasound of both common carotid arteries. Anti-oxLDL antibody levels were determined by ELISA. Results: In the whole study population we found a negative correlation between PON1 activity and IMT (r = -0.27, p = 0.011), and between salt-stimulated PON1 activity and IMT (r = -0.24, p = 0.02). Both PON1 activity and salt-stimulated PON1 activity negatively correlated with anti-oxLDL levels (r = -0.28, p = 0.008; r = -0.26, p = 0.01). PON1 activity was lower in patients compared to controls; however, the difference was not significant. PON1 phenotype distribution of patients and controls did not differ significantly. Conclusion: The importance of PON1 activity as a predictive risk factor for early-onset occlusive carotid artery disease should be assessed in future studies. Copyright (C) 2007 S. Karger AG, Basel.