Associations of the PON1 rs662 polymorphism with circulating oxidized low-density lipoprotein and lipid levels: a systematic review and meta-analysis

BackgroundSeveral meta-analyses have demonstrated that the rs662 polymorphism in Paraoxonase 1 gene (PON1) gene is associated with coronary heart disease (CHD). However, it is still uncertain whether this polymorphism is associated with the plasma levels of oxidized low-density lipoprotein (Ox-LDL) and lipids. This meta-analysis is aimed to clarify the relationships between the rs662 polymorphism and plasma levels of Ox-LDL and lipids.MethodsBy searching in PubMed, Google Scholar, Web of Science, Cochrane Library, Wanfang, VIP and CNKI databases, 5 studies (1369 subjects) and 85 studies (46,740 subjects) were respectively identified for Ox-LDL association analysis and lipid association analysis. Standardized mean difference (SMD) was used to estimate the effects of the rs662 polymorphism on plasma Ox-LDL and lipid levels.ResultsThe carriers of the variant R allele had higher levels of Ox-LDL (SMD=0.23, 95% CI=0.10-0.36, P<0.01), triglyceride (TG) (SMD=0.06, 95% CI=0.01-0.11, P=0.02), total cholesterol (TC) (SMD=0.04, 95% CI=0.00-0.07, P=0.05) and low-density lipoprotein cholesterol (LDL-C) (SMD=0.04, 95% CI=0.00-0.08, P=0.04) than the non-carriers.ConclusionsThis meta-analysis suggests that the association between the PON1 rs662 polymorphism and CHD may partly be mediated by abnormal Ox-LDL and lipid levels caused by the R allele.