Serum Paraoxonase-1 Activity in Rheumatoid Arthritis Patients as a Risk Factor for Cardiovascular Comorbidity

Abstract

Background: Cardiovascular disease is a leading cause of morbidity and mortality in rheumatoid arthritis (RA) patients through progressive atherosclerosis. Inflammation plays a crucial role in atherogenesis. Paraoxonase-1 (PON1) has important role in decreasing susceptibility of LDL to lipid peroxidation and prevent or at least limits the oxidation of HDL which play a role in decreasing the susceptibility to atherosclerosis. Aim of the study: To estimate serum paraoxonase-1 (PNO1), in rheumatoid arthritis patients and its correlation -if any to disease activity and lipid profile. Methods: Sixty rheumatoid arthritis patients, attending the rheumatology department at Benha teaching hospital and thirty healthy volunteers were included in this study. Both groups were subjected to full history taking, clinical examination, laboratory assessment of serum paraoxinase-1 level, lipids profile, CBC, ESR and CRP. Results: The mean serum PNO1 level in RA patients was (41.53±31.79 U/ml) and this was highly significantly lower than its level in control group (177 ± 40.77 U/ml) (p<0.001). Correlations between this level and different laboratory and clinical parameters showed significant negative correlations with ESR, CRP, DAS-28 score, cholesterol and LDL. While serum PON-1 shows significant positive correlation with HDL. ROC curve was obtained to assess for the validity of paraoxinase-1 in prediction of cardiovascular risk in severly active RA patients, it showed that paraoxinase -1 at a cut off value ≤ 26 can significantly predict cardiovascular risk in severly active RA patients, with sensitivity 76.5% and specificity 72.1%. Conclusion: low serum paraoxinase-1 activity is a real risk factor for cardiovascular disease in RA patients, as it is significantly negatively correlated with RA disease activity.