Diminished serum paraoxonase activity in patients with coronary artery calcification.

BACKGROUND Previous studies have shown an association between paraoxonase (PON) activity and the presence and severity of coronary atherosclerosis. AIM To demonstrate any association between serum PON activity and the presence and severity of coronary artery calcification (CAC). METHODS A total of 156 consecutive patients having the suspicion of coronary atherosclerosis or needing risk stratification for cardiovascular events were included in the present study. Peripheral venous blood samples of all participants to measure serum PON activity were collected before undergoing multidetector computed tomography, which was used to determine the presence and quantity of CAC. RESULTS Serum PON-1 levels were lower in the CAC group compared to the no CAC group (60 [35-96] U/L vs. 291 [230-371] U/L, respectively, p < 0.001). There was a significant negative correlation between total CAC score and PON (r2 = 0.335, p < 0.001). In multivariate analysis, the significant and independent predictors of the presence of CAC were male sex, high-sensitive C-reactive protein, and PON. Similarly, increased PON was significantly and independently associated with freedom from CAC. In receiver operating characteristics analysis, PON level < 197 U/L had 87% sensitivity, 91% specificity, 93% positive predictive value, and 85% negative predictive value in predicting CAC. CONCLUSIONS Diminished serum PON activity is significantly and independently associated with the presence and severity of CAC, and vice versa.