Association between PON1 activity and coronary heart disease risk: a meta-analysis based on 43 studies

Paraoxonase 1 (PON1) is reported to have antioxidant and cardioprotective properties. The relationship between PON1 activity and coronary heart disease (CHD) risk in humans has been reported among various ethnic populations in the past decade. However, these studies have yielded contradictory results. To investigate this inconsistency, we conducted a meta-analysis of 43 studies involving a total of 20,629 subjects to evaluate the effect of PON1 activity on susceptibility for CHD. We also systematically explored potential sources of heterogeneity using subgroup analysis and meta-regression. Significant decreases paraoxonase activity of PON1 were observed in CHD patients compared with non-CHD controls with SMD of -0.78 (95% CI: -0.98, -0.57; P<0.001). Similar results were also found for arylesterase activity of PON1 with SMD of -0.50 (95% CI: -0.64, -0.36; P<0.001). In the subgroup analysis by ethnicity, CHD phenotype, sample size, source of controls, mean age and BMI of cases, significantly increased risks were also found. In addition, our analyses detected a possibility of publication bias with an overestimate of the true association by smaller studies. This meta-analysis demonstrated that decreasing in PON1 activity is a risk factor associated with increased CHD susceptibility. However, additional very large-scale studies are warranted to provide conclusive evidence on the effects of PON1 activity on risk of CHD.