Association between PON1 L55M polymorphisms and risk of coronary heart disease: a meta-analysis based on 46 case-control studies

The purpose of the current meta-analysis was to explore the association between PON1 L55M polymorphisms and risk of CHD. Relevant studies were enrolled after a systematical literature search of Pubmed, Embase, OVID, and Web of Science databases in English. Odds ratios (ORs) with 95% confidence intervals (CIs) were used in different genetic models to evaluate the strength of association. Funnel plots and Egger's tests were performed to evaluate publication bias. Subgroup analyses were conducted by ethnicity, diagnosis, sample size, and results of HWE testing. A total of 46 studies, involving 15,554 cases and 18,137 controls, were included in this meta-analysis. Overall analysis showed an insignificant association between PON1 L55M polymorphisms and CHD under allelic (OR: 1.06, 95% CI: 0.99-1.13, P = 0.118), homozygous (OR: 1.12, 95% CI: 0.95-1.31, P = 0.166), heterozygous (OR: 1.11, 95% CI: 0.95-1.31, P = 0.199), recessive (OR: 1.04, 95% CI: 0.97-1.11, P = 0.34), and dominant (OR: 1.13, 95% CI: 0.96-1.33, P = 0.13) models. However, subgroup analyses showed a significant association in Asians. No association was observed between PON1 L55M polymorphisms and MI. Subgroup analyses of studies with sample sizes > 500 and p of HWE testing > 0.05 yielded insignificant results. In conclusion, L55M polymorphisms in PON1 genes are not associated with susceptibility to CHD. However, the association was significant in Asian populations. More high-quality studies should be carried out to validate present conclusions.